IPEN: Recent submissions

  • IPEN-DOC 26838

    RIBEIRO, E.P. ; FARNEZE, S.K. ; COUTO, A.A. . Shot peening effect in F138 stainless steel surface modification. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Resumo expandido... São Carlos, SP: Aptor Software, 2019. p. 2632-2634.

    Abstract: Stainless steel F138 is the most widely used steel as biomaterial. This metal has low toughness, so metallic implants are prone to wear [1]. Residual compressive stress and surface toughness increase can improve materials life fatigue. Shot peening is a mechanical surface treatment in which many small spheres are accelerated and blasted in materials surface, inducing residual compressive stress on materials surface. Surgical implants are submitted to this treatment to generate surface roughness increase for better adhesion too [2]. In this work, shot peening was performed using four different conditions to verify the effect on surface modification. Microscope techniques, x-ray diffraction, residual stress, toughness and roughness measurements were used to validate the tests. In conclusion, shot peening is an effective surface treatment to induce residual stress and increase roughness and toughness. Keywords: F138, Residual Stress, Shot Peening, Stainless Steel.

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  • IPEN-DOC 26837

    ROSSI, MARIANA C.; BAYERLEIN, DANIEL L. ; BRANDÃO, JAQUELINE de S.; PFEIFER, JOÃO P.H.; ROSA, GUSTAVO dos S.; KRIECK, ANDRE M.T.; MARTINEZ, LUIS G. ; SAEKI, MARGARIDA J.; ALVES, ANA L.G.. Preparation of porous ternary alloy Ti-34-Nb-6Sn / Mg for the implant. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1042-1042.

    Abstract: Titanium alloys are designed in order to provide attractive mechanical properties, including Young's modulus, high mechanical strength and biocompatibility [1]. These properties are achieved when titanium structured under β phase, and the selection of non-toxic beta-stabilizing metals is important for the improvement of the alloys. In order to create a good interaction at the bone-implant interface, it is interesting that these biomaterials also have adequate porosities for the bone cells to adhere on its surface, and the bone tissue to grow around the prosthesis. Thus, the purpose of this work was to produce the Ti-34-Nb-6Sn alloy by the powder metallurgy technique allied to the magnesium space holder. After the synthesis, the structure of the material was characterized by X-ray diffractometry (XRD) and its morphological and compositional analysis, carried out by Scanning Electron Microscopy (SEM) and X-ray dispersive energy (EDX). The apparent porosity analysis was made by the Archimedes method. In the biological assay, stem cells derived from equine bone marrow were seeded on the surface of the materials in order to obtain information about cytotoxicity and cell adhesion. The results of XRD and MEV confirmed the formation of the alloy (PDF: 25-977), being that the proportion of phase β was greater than the phase α (PDF: 44-1288,41-1352), and the evaporation of Mg, as well as a significant increase of porosity, which was also confirmed by the Archimedes method. Additionally, according to SEM, the cells showed good adhesion on the surface of the material, as well as inside the formed pores. According to the techniques used, it was then possible to obtain β phase rich titanium alloy with significant porosity on which the cells adhered satisfactorily.

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  • IPEN-DOC 26836

    BOTTA, WALTER J.; LEAL NETO, RICARDO M. ; JORGE JUNIOR, ALBERTO M.; ZEPON, GUILHERME; ISHIKAWA, TOMAZ T.; BOLFARINI, CLAUDEMIRO; KIMINAMI, CLAUDIO S.; LEIVA, DANIEL R.. Mg-based composites for hydrogen storage. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 47-48.

    Abstract: Magnesium hydride can be already considered as the traditional hydrogen storage material despite some unanswered fundamental questions concerning its properties. These questions concern the understanding of the activation (or first hydrogen absorption) step, the role of the additives in the absorption / desorption kinetics and the synergy between phases in the absorption / desorption kinetics, in the case of composites systems. Recent results indicated that modifications of conventional processing routes to synthesize hydride-forming systems might have a strong role in the hydrogen storage behavior of different metals and compounds. The present work shows results of Mg-TiFe and Mg-LaNi5 composites that have been produced by new approaches of the usual techniques, such as high-energy ball milling (HEBM) and cold rolling (CR) under inert atmosphere. Structural characterization was carried out by X-ray diffraction (XRD) and scanning and transmission electron microscopy (SEM and TEM). H-absorption / desorption kinetics were measured in a Sievert’stype apparatus and by differential scanning calorimetry (DSC) coupled with thermogravimetric analysis (TGA) and mass spectrometry (QMS). MgH2 hydride was formed at room temperature in Mg-TiFe composites produced by HEBM, in this case with an important improvement in the hydrogen absorption kinetic as compared with pure Mg. MgH2-LaNi5 composites were prepared by cold rolling under an inert atmosphere and the composite presented faster hydrogen absorption/desorption kinetics and reduced desorption temperatures in comparison to MgH2. These results are discussed in view of the above fundamental questions, in particular considering the possible synergy between Mg and the second phase (TiFe or LaNi5) in the modification of absorption and desorption kinetics.

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  • IPEN-DOC 26835

    LAZARIN JUNIOR, ELOI; MUNHOZ JUNIOR, ANTONIO H.; MIRANDA, LEILA F. de; SARMENTO, BRUNO F.C.C.; BERNUSSI, AYRTON; LIMA, NELSON B. de ; ROSSI, MAURA V.; PERES, RENATO M.; FLORENCIO, ODILA. Metformin release with pseudoboehmite. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 955-956.

    Abstract: Diabetes Mellitus is a chronic disease in which high levels of blood glucose are found. It arises when the pancreas does not produce enough insulin, a hormone that regulates blood sugar concentration. It also occurs when the body does not properly use the insulin it produces. There are two main forms of diabetes: type 1 diabetes, the treatment of which is insulin injections, and type 2 diabetes, where the body's cells do not respond to insulin properly. In Brazil the diseases that most affect the population are diabetes, hypertension and stroke. The number of Brazilians diagnosed with diabetes has grown 61.8% in the last 10 years. In 2006, 5.5% of the population had the disease and in 2016 8.9% [1]. It has also been observed in Brazil that diabetes increases with age and is almost three times higher among those with lower schooling. People between the ages of 18 and 24 have a rate of 0.9%, between 35 and 44 years old, the rate is 5.2%, and among people aged 55-64 years, the number reaches 19.6%. The largest registry, however, is in the population aged 65 years or older, which presents an index of 27.2%. In recent years, several papers reported the use of pseudoboehmite for use in controlled drug delivery systems. The drugs tested include atenolol [2], Glucantime® [3], acyclovir [4] and DOX, a typical chemotherapeutic anticancer drug [5]. In this research pseudoboehmite was produced by sol-gel process and metformin was incorporated in the gel of pseudoboehmite. After that the gel was vacuum filtered and dried to obtain a powder by freeze-drying. The dry powder was characterized by x-ray diffraction, thermal analysis (Thermogravimetric analysis and differential thermal analysis), nitrogen adsorption isotherm, specific surface area by B.E.T. method and scanning electron microscopy using secondary electron detector and EDS detector. The results shows that the drug was homogeneously incorporated in the pseudoboehmite.

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  • IPEN-DOC 26834

    ANDRADE, ARNALDO H.P. de ; LOBO, RAQUEL de M. ; BREDA, FRANCISCO J. ; CASTAGNET, MARIANO . Mechanical anisotropy of ABS specimens 3D printed by FDM. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2564-2564.

    Abstract: Additive manufacturing (AM) has been developed as a technique for fast fabrication of component parts through 3D printing, using a process of adding successive layers, one after another. The Fused Deposition Modeling (FDM) technique is a 3D printing process that generally uses a thermoplastic filament as the printing base material. The material is fed by a coil and the head of the extruder performing the process is heated. Printing can be done in several directions, depending on the purpose of the component part. In this work mechanical tests were done on ABS (Acrylonitrile-Butadiene-Styrene) tensile specimens built by FDM, in different orientations, to analyze its properties and to make a correlation between these properties and the influence of the printing direction in the final product. The tensile specimens in dog bone shaped were tested according to the ASTM D638 standards. The experiments were done at room temperature. The horizontal built specimens (H-specimens), fabricated in the z-direction, while the beads were layered along the x and y direction, parallel to the build table, showed the maximum resistance of 30 MPa. The specimens built with their gage length out of x-y plane (V-specimen and D-specimen, vertical and diagonal specimens respectively) presented lower ultimate strength, for instance 14 MPa for the Vspecimen. Additional investigation is on the way to understand the presence of defects (cavities and crazes) in the ABS microstructure since the literature points that the ability to manipulate it is the key to an improved performance of this type of structural material.

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  • IPEN-DOC 26833

    LEAL NETO, RICARDO M. ; VEGA, LUIS E.R.; FALCÃO, RAILSON B. ; LEIVA, DANIEL R.; ROCHA, CLAUDIO J. ; ISHIKAWA, TOMAZ T.; KIMINAMI, CLAUDIO S.; BOTTA, WALTER J.. Mechanical activation of TiFe for hydrogen storage: ball milling x cold rolling. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 49-50.

    Abstract: The aim of this work is to report some recent developments on the synthesis of TiFe by high energy ball milling and cold rolling, concerning hydrogen storage. Ball-milled TiFe was produced by two procedures, both under inert atmosphere and with various milling times. In the first one a powder mixture of TiH2 an Fe was milled, followed by a vacuum heat treatment to promote the reaction synthesis of TiFe compound [1]. Second procedure consisted of milling Ti and Fe powders with stearic acid (as a process control agent) after a pre-milling operation (with the same powders and without PCA) to prepare the surface of milling media. Both methods were conceived for avoiding strong adherence of the powders to the milling balls and vial, impairing the mechanical alloying. Cold rolling was performed on a ground TiFe ingot produced by arc melting [2]. After 20 to 40 passes under inert atmosphere, powder particles and thin cracked flakes were produced. Results showed that both milling procedures succeeded in avoiding unacceptable adherence to the milling media, with high loose powder yields. Whatever the route, nanostructured TiFe was obtained with no need of further thermal activation for the first hydrogenation. Hydrogen absorption capacities of about 1.0 wt% at room temperature was obtained with both milling procedures. Higher capacity (1.4wt%) was obtained with cold rolled TiFe (powder and flakes) after 40 passes. Some possible explanations for this difference are presented and discussed.

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  • IPEN-DOC 26832

    PIERETTI, EURICO F. ; NEVES, MAURICIO M. das . Magnetic susceptibility of a laser treated biomaterial. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2024-2024.

    Abstract: Austenitic stainless steel ISO 5832-1 is widely used as biomaterial due to its mechanical properties, chemical composition, degradation resistance and low cost. In this work, we evaluated the magnetic susceptibility of samples of this biomaterial, with laser texturing surface treatment in four different pulse frequencies, as well as samples without laser treatment, for comparison purposes. Relative magnetic permeability (μr) measurements were performed on a magnetic susceptibility scale. A Bruker magnetic force microscope (MFM), model SPM Multimode 8, with analysis processing software Nanoscope Analysis, was used in the Tapping Mode operation to perform naturally generated magnetic field measurements on the laser textured samples surfaces. The treatments affected the magnetic susceptibility of these surfaces, which was higher for the textured samples when compared to the other surface finishing conditions, which is undesirable for a biomaterial. The magnetic field evaluations by MFM are of qualitative character. Qualitatively distinct images of amplitude and phase difference signals were noted. This fact proved the results obtained by the technique of measurement of magnetic signals by precision scale. The analysis of the images obtained by MFM suggested that the parameters variation for laser texturing resulted in variation of intensities and distribution of magnetic field signals on this biomaterial’s surfaces.

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  • IPEN-DOC 26831

    BUGARIN, ALINE F.S. ; TERADA, MAYSA ; POLITANO, RODOLFO ; COSTA, ISOLDA . Investigation of the evolution and influence of hardening phases on the corrosive behavior of AA2198. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2120-2120.

    Abstract: The Al-Li alloys are 2XXX series aluminum alloys and has been gaining space in the aeronautical applications. Adding 1% by weight of Li to aluminum, reducing by 3% at the final density and increasing by an average of 6% in the modulus of elasticity of the material. The characteristics and advantages presented by the Al- Li alloys, together with the growing interest of the aeronautical industry, have resulted in the interest in studying the relationship between the microstructure and its corrosion behavior. Alloy 2198 is a third generation of Al-Li alloys. Alloy elements such as Cu, Li and Mg promote the increase of the mechanical strength of the alloy by solid solution and the precipitation of phases T1 (Al2CuLi), Ɵ '(Al2Cu) or S (Al2LiMg). Phase T1 is the main hardening phase of the material and because it is more electrochemically active, it decreases the corrosion resistance. In this work, the AA2198 as received was solubilized at 500 °C to clear the thermal history of the material. A homogenization treatment was carried out for 1 h and 4 h with mechanical vacuum and an oven with argon controlled atmosphere. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) tests were performed to verify the kinetics and influence of phase precipitations on the mechanical response of the material. The resistance to corrosion of the different homogenization conditions was investigated with electrochemical tests, such as Open Circuit Potential (OCP) and Polarization.

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  • IPEN-DOC 26830

    SANTANA, JESSICA C.C. de C.; SILVA, REJANE M.P. da ; ANTUNES, R.A.; SANTOS, SYDNEY F.. Influence of decarburization on the local corrosion behavior of the SAE 9254 spring steel. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2199-2199.

    Abstract: Decarburization is an unwanted metallurgical phenomenon comprising the loss of carbon from the steel through outward diffusion and oxidation on the surface at high temperatures. As this phenomenon leads to phase transformations in a small region close to the surface, it is likely expecting some effects on the local chemical reactivity of the steel. This, in turn, would account for the appearance of preferential anodic sites that can act as localized corrosion spots. Macroscopic corrosion symptoms, observed by conventional corrosion techniques, express only the final step of a complex and dynamic sequence that begins at the microscopic level. Several localized electrochemical techniques can be used to characterize local corrosion processes. One of them is the scanning electrochemical microscopy (SECM). The aim of the present work was to study the surface chemistry, microstructure and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 800, 850, 900 and 950 °C followed by oil quenching. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by X-ray photoelectron spectroscopy. The local electrochemical activity was probed by SECM. Microstructural characterization and XPS analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and also Si and Cr oxides formed during heat treatments. The presence of the ferritic layer enhanced the multiphase character of the steel microstructure in the region of partial decarburization of sample A900, increasing iron oxidation and, therefore, the local electrochemical activity for this condition.

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  • IPEN-DOC 26829

    LOBO, RAQUEL de M. ; MORCELLI, APARECIDO E.; BREDA, FRANCISCO J. ; CASTAGNET, MARIANO ; ANDRADE, ARNALDO H.P. de . Fracture surface analysis of ABS samples printed by the FDM method. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2567-2567.

    Abstract: FDM (Fused Deposition Modeling) is one of the most used technique in additive manufacturing (AM). It can be summarized as printing small components through a heated thermoplastic filament, which is deposited layer by layer through a 3D printer. The print head can be programmed to perform the job in different directions (X, Y and Z) even with predetermined slopes. In this work, flat tensile specimens were prepared in different directions using an ABS (Acrylonitrile-Butadiene-Styrene) filament with a processing temperature between 210-225 ° C. After tensile tests, the fracture surfaces were analyzed to get a better understanding of the deformation and fracture processes. The crosssection view of specimen´s morphology was examined with a scanning electron microscope at a very low accelerating voltage (1 kV). The specimens were coated with gold using a sputtering system. The specimens that showed the smaller ultimate strength (named V-specimen) presented numerous large cavities in its microstructure suggesting that these voids may have a major contribution to the mechanical performance of the material.The fracture surface also shows a possible pull-out between layers indicating a weak point in the microstructure of the built sample that’s requires further investigation.

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  • IPEN-DOC 26828

    RAMANATHAN, LALGUDI V. ; FERNANDES, STELA M.C. ; CORREA, OLANDIR V. . Effect of mixed nanocrystalline rare earth oxide coatings on high temperature oxidation of a ferritic stainless steel AISI 409. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 414-414.

    Abstract: Rare earths (RE) have been used to improve the high temperature oxidation resistance of chromium dioxide and alumina forming alloys. The RE can be added to the alloy as elements or as oxide to form dispersions. It can also be applied as a RE oxide coating on the surface of the alloy. In this investigation the sol-gel technique was used to prepare sols of the RE oxides as it produces nanocrystalline oxide particles. In an effort to increase further the oxidation resistance of high temperature alloys, optimization of RE oxide additions to the alloy surface was attempted. This paper presents the effect of nanocrystalline oxide gel coatings of CeO2, Nd2O3, Pr2O3, CeO2 + Nd2O3, CeO2 + Pr2O3 and Pr2O3 + Nd2O3 on the oxidation behavior of a ferritic stainless steel AISI 409 at 1000 °C in air using a thermogravimetric balance. The morphology of the pure oxides was studied and the following formats were observed: CeO2 – rods; Nd2O3 – platelets; Pr2O3 – needles; La2O3 – cuboids. The average oxide particle sizes and the average crystallite sizes were also determined. The oxidation rate of the coated steel specimen was significantly less than that of the uncoated steel specimen, due to formation of a fine layer of chromium dioxide at the steel/oxide interface. The oxidation rates of the different REO coated steel specimens varied with the type of REO. The mixed oxide containing Pr2O3 increased significantly the oxidation resistance of the steel. The CeO2 + Nd2O3 mixture did not increase oxidation resistance of the steel further, compared to those with either one of these two rare earth oxides. The differences in the influence of a specific rare earth oxide or a mixture are attributable to differences in the ionic radii of the RE and the morphology as well as the crystallite sizes of the RE oxides.

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  • IPEN-DOC 26827

    AGUIAR, DEIZE B. dos S.; QUEIROZ, FERNANDA M.; VERISSIMO, NATHALIA C.; AYUSSO, VICTOR H. ; PEREIRA, VICTOR F.; FONSECA, EDUARDO B. da; MELO, HERCILIO G. de; COSTA, ISOLDA ; TERADA, MAYSA ; BUGARIN, ALINE F.S. . Effect of Ce on the corrosion resistance of anodized AA2024-T3 FSWed. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2111-2112.

    Abstract: Friction stir welding (FSW) is a solid-state joining technique, which has numerous advantages over conventional fusion techniques, such as automation and reproducibility, environmentally friendly, and capability to weld large thicknesses in a single pass. AA2024 are widely used in the aerospace industry due to their properties as lightweight, high specific strength and durability. However, they are prone to localized corrosion due to its high amount of intermetallics. New anodizing and sealing processes have been studied due to the environmental and health problems related to the sealing treatment containing hexavalent chromium ions. This has encouraged the search for new processes for surface treatment of metals. Recent studies are pointing towards tartaric-sulphuric anodizing, as a viable alternative for the corrosion protection of aluminum alloys, including surface treatments with cerium ions. Other promising method to protect the exposed metal surface is to use eco-friendly alternative corrosion inhibitors in combination with a barrier coating system. Sol–gel coatings have also been extensively studied as potential pre-treatments not associated to toxic residues for aluminum alloys surface preparation prior to paint. It has been demonstrated an efficient alternative for replacement of the chromate technology. In this study, friction stir welded samples were anodized and then sealed in an aqueous solution with the addition of cerium ions at 70 °C. The effect of Ce on the characteristics of the surface film formed, such as morphology and corrosion resistance, was investigated by SEM and electrochemical impedance spectroscopy. Samples unsealed or hydrothermally sealed were also tested for comparison. The EIS results showed that the addition of Ce (III) ions improved the corrosion resistance of the AA 2024-T3 TSA anodized and hydrothermal sealed.

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  • IPEN-DOC 26826

    GIAROLA, JOSEANE M.; PEREIRA, GUALTER S.; KUGELMEIER, CRISTIE L.; TERADA, MAYSA ; MARCOMINI, JOSE B.; ROVERE, CARLOS A.D.; AVILA, JULIAN A.; BOSE FILHO, WALDEK W.. Corrosion behavior of friction stir welded API X70 steel joints. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2171-2171.

    Abstract: The ever-increasing demand for fossil fuels has pushed the oil and gas industry to search for new deep water wells and in more aggressive environmental conditions, such as the pre salt where the presence of CO2 and H2S concentrations, has led to the development of new materials and manufacturing processes. For pipeline construction, Friction Stir Welding (FSW) process is a promising candidate to be used in the girth welding procedure, and research studies must be carried out to understand the effect of this new processing on the pipeline life under the in-service conditions (environment, fatigue). The present work is part of a research project aiming to investigate the effect of a saline environment on the mechanical properties of an API-5L-X70 steel, welded by FSW. Therefore, in this work, the results of the corrosion behavior analysis carried out on the FSW welded joint, considering a 3.5% NaCl solution, are presented. The corrosion behavior was investigated based on potentiodynamic polarization tests on the different regions of FSW welded joint, i.e., the base metal (BM) and stirred zone (SZ). Gel visualization tests, considering the whole welded joint, were also conducted. The two FSW regions showed similar polarization curves in terms of corrosion potential (Ecorr), corrosion current density (icorr) as well as anodic current density values. In the gel tests, a preferential localized attack on any of the regions of the FSW welded joint was not observed. These results can be interpreted as evidence that the corrosion behavior of the FSW welded joint was not significantly affected by the different metallurgical microstructures formed by the FSW processing.

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  • IPEN-DOC 26561

    SONA FILHO, CELSO R. ; BENTO, RODRIGO T. ; SILVA, CECILIA C.G. e ; PILLIS, MARINA F. . Physical-chemical characterization of Si3N4-TiO2 ceramic nanocomposites obtained to biomedical applications. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1051-1051.

    Abstract: Silicon nitride based ceramics (Si3N4) are very important materials in the engineering and medical fields because of their physical, chemical, tribological and mechanical properties. However, some researchs have been carried out in order to obtain silicon nitride ceramics with improved biological behavior, including studies about the effect of nanoparticles on their bioactivity. In this work, Si3N4-TiO2 nanocomposites were synthesized and characterized by their physical, chemical and bioactive properties. Initially, Si3N4, MgO, SiO2 and CaO powders were mixed in a ball mill for 24 h The mixture was then dried at 100 ºC for 1 h under the nitrogen atmosphere. Subsequently, the samples were coated with TiO2 from the sol-gel process. The precursor solution of titanium dioxide (TiO2 ) was prepared from the mixture of titanium (IV) isopropoxide and isopropanol at a ration of 1:10. The pH of the solution was adjusted to 3 by the addition of sulfuric acid. The precursor solution was dispersed by constant stirring at 50 ºC for 1 h. The samples were immersed for 10 minutes in this solution at room temperature and then dried for 24h under UV light. The samples were calcined at 400 and 500 ºC for 60 min to obtain Si3N4-TiO2 nanocomposites. The microstructure of the materials were anayzed by scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The samples bioactivity was evaluated by in vitro tests using SBF (Simulated Body Fluid) solution at 37 ºC for 9 days of immersion. The nanocomposites showed good quality, high uniformit of coating and greater adhesion to TiO2 to the substrate of Si3N4. The formation of CaP deposits with globular structure on the samples surface during the SBF experiment is a strong indication of the bioactivity of the nanocomposites. The results suggest that Si3N4-TiO2 ceramic nanocomposites have great potential to be used in biomedical applications.

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  • IPEN-DOC 26554

    NERY, JOSE G.; RATERO, DAVI R.; SILVA, DANILO A. da; MARUMO, JULIO T. ; ARAUJO, LEANDRO G. de ; MEDEIROS, VINICIUS L.. Hydrothermal and assisted microwaved syntheses of Stanno and Yttrium metallosilicates as heterogeneous catalyst for biodiesel production and environmental remediation. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 484-484.

    Abstract: This study reports the synthesis, physicochemical characterization by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and solid-state MAS NMR (1H, 23Na, 29Si and 89Y and 119Sn MAS NMR) of a stanno and yttrium metallosilicate and their application as a heterogeneous catalyst for biodiesel production via ethanolysis and methanolysis routes using edible, non-edible an waste oils as feedstocks and environmental remediation. Heterogenous catalytic studies in the transesterification of refined edible, non-edible, and waste oils have resulted in high yields of FAMEs and FAEEs (fatty acid methyl and ethyl esters), nevertheless the highest FAMES (98.2%) and FAEEs (96.6%) yields were obtained for non-edible microalgae oil extracted from the genetically modified heterotrophic algal strain Prototheca moriformis. Catalytic studies also using nonedible macaw palm oil (Acrocomia aculeata) with a high content of free fatty acids (FFAs) demonstrated that the catalyst could simultaneously perform esterification and transesterification reactions using using different sources of lipids feedstocks, notably those that do not compete with food production [1]. On the other hand, Yttrium metallosilicate were very efficient in the separation, binding and chemical stabilization of hazardous inorganic, organic and radioactive species such as lead ( Pb2+, Cd2+, Ba2+ , Cs+ and Sr2+) in aqueous systems.

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  • IPEN-DOC 26543

    SANTOS, EMANUELLA C. dos; BATISTA, BEATRIZ da S.; LIMA, RUANA C.; ALENCAR, LUCIANA M.R.; SANTOS, ADENILSON O. dos; PEDROCHI, FRANCIANA; OTUBO, LARISSA ; LANG, ROSSANO; SILVA, LUZELI M. da. Bioactivity study of Co-Cr alloys doped with tantalum for biomedical applications. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1017-1018.

    Abstract: Co-Cr alloys are well known because of its high wear resistance, mechanical strength and corrosion resistance due to the chromium oxide passive layer formation that protects the material surface [1].The addition of alloying elements, particularly Mo and W, improve the properties of Co-Cr bioalloys, although these materials can still be improved to meet the requirements for a biomaterial.Thus, considering that tantalum is a bioactive metal, it can be an interesting option to improve the biocompatibility properties of these alloys[2].The present study aims the synthesis and in vitro evaluation bioactivity of Co-Cr alloy doped with tantalum.The synthetized alloys were submitted to a surface treatment and subsequentlyimmersed in Simulated Body Fluid (SBF) for 28 days. The samples bioactivity was evaluated by using X- ray Diffraction (DRX), Scanning Electron Microscopy (SEM), Dispersive Energy Spectroscopy (EDS) and Atomic Force Microscopy (AFM) techniques. X- ray diffraction analysisin the SBF immersed samples shown a small intensity peak characteristicof hydroxyapatite while MEV and EDS results revealeda surface structure with the presence of P, Mg, Ca and Oelements. The grain growth dynamics on the samples surfaces was observed by using AFM measurements.

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  • IPEN-DOC 26533

    BORAZANIAN, TATYANA C.F. ; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Influence of the heat treatment on the photodegradation efficiency of the supported TiO2 catalysts obtained by a facile airbrush spray-coating. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1665-1666.

    Abstract: One of the main topics of thin films processing routes based on sol-gel is the need for low-cost and simple techniques [1]. Airbrush spray-coating method has been applied to coat materials, due to its cost-effective, large area and versatile characteristics [2]. However, this technique is not yet sufficiently explored for supported catalysts employed on the water treatment. In this work, titanium dioxide (TiO2) films were successfully deposited on borosilicate substrates by a facile airbrush spray-coating technique, at room temperature, from a solution of titanium (IV) isopropoxide diluted in isopropanol. The angle of the cold spray was fixed in 45°, and the feed rate was 17 mm.s-1. The coated specimens were dried at 100 °C for 60 min, and then heat treated at 300, 450 and 500 °C for 30 min to evaluate the influence of the temperature process on the methyl orange dye degradation under UV light. The catalysts obtained showed a great surface covering, highly porous surface, and good adherence to substrate. The films presented the formation of TiO2-anatase phase. Methyl orange dye degradation experimental results indicated that the TiO2 film heat treated at 500 °C presented a higher photocatalytic behavior, that exhibited 68.3 % of the dye degradation for 300 minutes under UV radiation – around 18.5 % more efficient than the supported catalysts prepared at 300 and 450 °C, with a photocatalytic efficiency of 31.6 % and 57.7 %, respectively. The study of the influence of heat treatment on the photocatalytic activity suggests the existence of an ideal temperature in which the photocatalyst exhibits the better photodegradation performance. The results suggest that the supported TiO2 catalysts deposited by the airbrush spraycoating method have a promising practical application for the green treatment of organic pollutants.

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  • IPEN-DOC 26532

    MARCELLO, BIANCA A. ; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Effect of the thickness of TiO2 films on the photodegration of methyl orange dye. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1696-1696.

    Abstract: The increase of the disposed of azo dyes such as methyl orange (MO) by textile and allied industries in the wastewater results in a significant increase of pollutants, which requires the development of new degradation materials and techniques to purify the effluents [1]. Heterogeneous photocatalysis using titanium dioxide (TiO2) films is a highly efficient oxidative process for water treatment [2]. The TiO2 films were grown on borosilicate substrates by metalorganic chemical vapor deposition (MOCVD) at 500°C, and the growth time was controlled in order to obtain films with the thickness of 400, 600 1100 and 2100 nm. MO dye degradation was evaluated by using anatase-TiO2 as photocatalyst under UV light. The pH of the solutions was set on 2. The TiO2 films presented uniform thickness and well-defined columnar structure that grow perpendicular to the substrate surface. The increasing of the growth time increases both the thickness and the mean grain size of the films. All the films presented the formation of anatase-TiO2 crystalline phase grown preferentially oriented at (112). The results showed that the photocatalytic behavior of the films decreased with increasing the film thickness. The photocatalytic efficiency for the 400, 600, 1100 and 2100 nm films tested at pH 2 are respectively 39.2%, 30.2 %, 24.4 % and 12.2 %. When the thickness of the films augments, the mobility of the electrons is impaired due to the increase of the film opacity, which limits the light penetration through the catalyst, and difficults the diffusion of charge carriers required to activate the semiconductor surface. TiO2 catalysts grown by MOCVD technique is a practical promising application for the water treatment.

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  • IPEN-DOC 26825

    COUTO, CAMILA P. ; REVILLA, REYNIER; COSTA, ISOLDA ; PANOSSIAN, ZEHBOUR; ROSSI, JESUALDO ; TERRYN, HERMAN; DE GRAEVE, IRIS. Investigation of electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si before and after hot stamping process by means of SKPFM measurements. In: EUROPEAN CORROSION CONGRESS, September 9-13, 2019, Seville, Spain. Abstract... 2019.

    Abstract: The demand for hot stamped components has been growing in structural vehicle applications, due to the advantages of combining lightweight design and safety improvement. Boron-manganese 22MnB5 steel is the most common grade for hot stamping applications. After the thermomechanical process, the steel exhibits up to 1,500 MPa of tensile strength with the absence of the springback effect. The hot stamping process involves heating the steel blank to the austenitization temperature and then transferring it from the furnace to the press tool, where the material is formed and quenched simultaneously. Due to high temperatures during the process, the steel blank is protected with a metallic coating to avoid the steel decarburization and oxidation. Hot-dip Al-Si is the most applied coating system on boron-manganese steel for hot stamping applications. It is known that, during hot stamping, diffusion takes place changing the coating layer morphology. The objective of this study is to investigate the effect of the hot stamping process on the electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si by means of the SKPFM technique. Moreover, the samples were characterized by means of FE-SEM/EDS. The SKPFM results showed that, before the hot stamping process, there is a high difference of potential between the coating layer and the steel substrate. After hot stamping, this difference decreases. In both conditions (before and after hot stamping), the coating layer is less noble than the steel substrate. It was also observed that the steel substrate potential also decreased after the hot stamping process. This could be a consequence of iron diffusion towards the coating layer and the recrystallization of the substrate after the thermo-mechanical process.

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  • IPEN-DOC 26824

    SILVA, REJANE ; MILAGRE, MARIANA ; OLIVEIRA, LEANDRO; ANTUNES, RENATO; DONATUS, UYIME ; COSTA, ISOLDA . Influence of surface finishing on the electrochemical activity of the 2098-T351 aluminum alloy. In: EUROPEAN CORROSION CONGRESS, September 9-13, 2019, Seville, Spain. Abstract... 2019.

    Abstract: In this work, scanning electrochemical microscopy (SECM) measurements were employed to characterize the electrochemical activities of polished and as-received surfaces of the 2098-T351 aluminum alloy (AA2098-T351). The effects of the near surface deformed layer (NSDL) and its removal by polishing on the electrochemical activities of the alloy surface were evaluated and compared by the use of different modes of SECM. Confocal Laser Scanning Microscopy (CLSM) and energy dispersive X-ray spectroscopy (EDS) were also employed to characterize the morphology of the surfaces. The surface chemistry was analyzed by X-ray Photoelectron Spectroscopy (XPS). The generation/tip collection (SG/TC) and competition modes of the SECM were used to study hydrogen gas (H2) evolution and oxygen reduction reactions, respectively. H2 evolution and oxygen reduction were more pronounced on the polished surface compared to the asreceived surface that revealed lower electrochemical activities showing that either the NSDL largely decreased the local electrochemical activities at the AA2098-T351 surface.

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  • IPEN-DOC 26823

    MACHADO, CARULINE de S.C. ; SILVA, REJANE M. da ; ARAUJO, JOAO V. de S. ; DONATUS, UYIME ; MILAGRE, MARIANA X. ; KLUMPP, RAFAEL E. ; ROSSI, JESUALDO L. ; COSTA, ISOLDA . Effects of chloride ion concentration on the corrosion behavior of the AA2198-T8 alloy. In: EUROPEAN CORROSION CONGRESS, September 9-13, 2019, Seville, Spain. Proceedings... 2019.

    Abstract: In this work, the influence of chloride ions concentration on the corrosion behavior of the AA2198-T8 alloy was evaluated. Immersion test and electrochemical analyses were performed in sodium chloride solutions of three concentrations, 0.001 mol L-1, 0.005 mol L-1 and 0.01 mol L-1. The results showed that the AA2198-T8 alloy was susceptible to localized corrosion (LC) and to severe localized corrosion (SLC) in all conditions investigated. The electrochemical results obtained by open circuit potential measurements, cyclic voltammetry and potentiodynamic polarization curves were associated with the corroded microstructure of the alloy. Although electrochemical techniques allowed differentiating the corrosion resistance as a function of chloride concentration, the result was strongly influenced by the corroded/uncorroded area ratio related to the SLC.

    Palavras-Chave: aluminium alloys; corrosion; electrochemical corrosion; electrochemistry; chlorides

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  • IPEN-DOC 26822

    CORREA, B.S. ; COSTA, M.S.; CABRERA-PASCA, G.; SENA, C.; PINTO, R.H.; CARVALHO JUNIOR, R.N.; FREITAS, R.S.; SAIKI, M. ; CORREA, E. ; CARBONARI, A.W. . Can natural oils improve the properties of magnetic nanoparticles?: A systematic study of iron oxide nanoparticles coated with oils from Amazon fruits. In: ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 64th, November 4-8, 2019, Las Vegas, Nevada, USA. Abstract... 2019.

    Abstract: The use of nanoparticles coated with different materials have been studied by many researchers to improve the quality of nanomaterials for biomedical applications such as controlled drug delivery, image contrast and treatment of cancer by magnetic hyperthermia [1]. In this work, we used oils extracted from ucuúba (Virola surinamensis), bacaba (Oenocarpus bacaba Mart.) and açaí (Euterpe oleracea Mart.) to coat Fe3O4 nanoparticles. The ucuúba, bacaba and açaí are native trees of the Amazon forest, whose oils are rich in fatty acids, such as lauric, myristic, steatic, oleic, palmitic, and linoleic acid, with different proportions. These pure oils, free of solvents, were obtained by the extraction method with carbon dioxide in the supercritical state [2], and then added during the synthesis process of iron oxide nanoparticles by thermal decomposition method [3]. The results of X-ray diffraction confirmed the formation of Fe3O4 single phase. The average size around 3 nm and spherical morphology of the magnetite nanoparticles was determined by transmission electron microscopy. The study of magnetic properties revealed a saturation magnetization (Ms) enhancement and high values of the anisotropy constant for Fe3O4 samples when coated with açaí (91.4 emu.g-1; 4.6 105 J.m-3) and ucuúba (80.6 emu.g-1; 9.3 105 J.m-3) oils, which present a large percentage of saturated total fatty acid. The results indicate that nanoparticles with sizes smaller than around 5 nm present Ms values as high as those found in bulk Fe3O4 and higher than those usually obtained for nanoparticles coated with oleic acid [4]. The neutron activation analysis (NAA) nuclear technique was used to determine with high accuracy the mass of Fe in the Fe3O4 core of nanoparticles in order to normalize the magnetization values [5]. These results show that natural oils have a great potential to produce stable and quality nanoparticles as compared with conventional coated.

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  • IPEN-DOC 26821

    NOGUEIRA, A.L.; MUNITA, C.S. ; COSTA, A.F.; GOMES, D.M.C.; KIPNIS, R.. Quantitative methods of standardization in cluster analysis: finding groups in data. In: ACHARYA, R. (Ed.); SWAIN, K.K. (Ed.); SATHYAPRIYA, R.S. (Ed.); REDDY, A.V.R. (Ed.); PUJARI, P.K. (Ed.) INTERNATIONAL CONFERENCE ON MODERN TRENDS IN ACTIVATION ANALYSIS, 15th, November 17-22, 2019, Mumbai, India. Abstract... Mumbai, India: Bhabha Atomic Research Centre, 2019. p. 76-76.

    Abstract: The archaeological study of ceramics using multi-elemental analytical techniques such as instrumental neutron activation analysis (INAA) is important in archaeology due to its potential to identify the raw materials used in their manufacture,and subsequently help to infer the degree of interaction among ancient communities. Several multivariate statistical methods are used in chemical composition data analysis, such as principal component analysis, cluster analysis and discriminant analysis. Pattern recognition approaches are divided into unsupervised learning and supervised learning. Cluster analysis is a technique for pattern recognition and is an unsupervised approach. When applying cluster analysis, raw data, or actual measurements, are not used directly. Thus, a problem that arises during cluster analysis involves the decision of whether or not to standardize the input variables before calculating measures of distance. The standardizationof variables is necessary in cases where the measure of dissimilarity, such as the Euclidean distance, is sensitive to differences in the magnitudes or scales of the input variables. The aim of this paper is to assess the impact, and evaluate the usefulness of three standardization techniques in determining the number of clusters for a data set of 140 ceramic fragments from eight archaeological sites from the upper Madeira river, Rondônia, Brazil, in which Na, K, La, Sm, Yb, Lu, Sc, Cr, Fe, Co, Zn, Rb, Cs, Ce, Eu,Hf, Ta, and Th mass fractions were determined by INAA.

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  • IPEN-DOC 26820

    SANTOS, U.P.M. ; LOURENÇO, F.R.; MOREIRA, E.G. . Experimental design and z-score results are useful tools for optimizing Instrumental Neutron Activation Analysis procedures. In: ACHARYA, R. (Ed.); SWAIN, K.K. (Ed.); SATHYAPRIYA, R.S. (Ed.); REDDY, A.V.R. (Ed.); PUJARI, P.K. (Ed.) INTERNATIONAL CONFERENCE ON MODERN TRENDS IN ACTIVATION ANALYSIS, 15th, November 17-22, 2019, Mumbai, India. Abstract... Mumbai, India: Bhabha Atomic Research Centre, 2019. p. 133-133.

    Abstract: In this study the optimization of procedures of an Instrumental Neutron Activation Analysis (INAA) method were carried out for the determination of the elements bromine, chlorine, magnesium, manganese, potassium, sodium and vanadium in biological matrix materials using irradiations up to 60 s at a pneumatic station. 2k experimental designs were applied for assessment of the individual influence of selected variables of the analytical procedure in the mass fraction results. The chosen experimental designs were the 23 and the 24, depending on radionuclide half-lives. Different certified reference materials and multi-element comparators were analyzed, considering the following variables: irradiation time, sample decay time, sample distance to detector and counting time. Gamma ray spectrometer, comparator concentration, and sample mass were maintained constant in this study. By means of statistical analysis experimental considerations, optimized experimental conditions for the analytical methodwere determined and will be adopted for the validation procedure of INAA methods at the Research Reactor Center of the Nuclear and Energy Research Institute (IPEN – CNEN/SP). Optimized irradiation and measurement conditions were established based on experimental design resultsusing the obtained z-scores for the various elements and experimental conditions.

    Palavras-Chave: chemical state; elements; experiment design; isotope ratio; matrix materials; neutron activation analysis; neutron activation analyzers

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  • IPEN-DOC 26819

    SILVA, S.A.; JUNQUEIRA, L.S. ; FRANKLIN, R.L.; SILVA, W.L.; FAVARO, D.I.T. ; MOREIRA, E.G. . Sedimentary profiles from a water supply reservoir at São Paulo, Brazil: trace and rare earth elements assessment by INAA. In: ACHARYA, R. (Ed.); SWAIN, K.K. (Ed.); SATHYAPRIYA, R.S. (Ed.); REDDY, A.V.R. (Ed.); PUJARI, P.K. (Ed.) INTERNATIONAL CONFERENCE ON MODERN TRENDS IN ACTIVATION ANALYSIS, 15th, November 17-22, 2019, Mumbai, India. Abstract... Mumbai, India: Bhabha Atomic Research Centre, 2019. p. 79-79.

    Abstract: A research project has been conducted by the Environmental Company of São Paulo State (CETESB) and the Nuclear and Energy Research Institute (IPEN) in important water supply reservoirs at São Paulo State in order to perform a wide evaluation on the content of rare earths and some trace elements in sediment profiles. In the present study, preliminary results for two sampling campaigns at the Graminha reservoir are presented:February/2015 (sites 1 and 3) and August / 2015 (sites 1 and 2). Sediment core samples (around 90 cm long) were collected in the dam and sliced at every 2.5 cm. Instrumental Neutron Activation Analysis (INAA) was applied to the sediment samples in order to determine some trace elements (As, Cr, Th, U and Zn) and rare earth elements (REE) (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb). The analytical methodology validation was performed by means of certified reference material analyses. As, Cr and Zn concentration values were compared to the oriented values from CCME (Canada) (TEL and PEL). Sediment quality was classified as good or very good for these elements according these criteria. Enrichment factor (EF) and Geoaccumulation Index (IGeo index)1were applied to the results by using the concentration values of the last layer of the 90.0 cm profile as background values for sediment contamination index assessment. EF>1.5 was found for REE, U and Th in the middle of the sediment profiles,in all sampling points, indicative of anthropogenic contribution. IGeo values in the range of1<IGeo<5 were found, being the sediments classified as moderate to very polluted for these elements. The normalization of REE concentrations with respect to a geological reference value, a useful tool to obtain a comparison among information from contamination sources2 was used in the present study by using NASC (North American Shale Composite) and PAAS (Post Archean Australian Shale) normalization as reference values. In addition, La/Sm, La/Yb and Sm/Yb ratios were calculated and discussed.The present study data are intended to start a sediment REE concentration data bank in water supply reservoirs and maybe they can be used in the future to establish legal limits for CETESB.

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  • IPEN-DOC 26818

    ARAUJO, S.G. ; LANDINI, L. ; ZEFERINO, G.R. ; SALVADOR, V.; SCAPIN, M.A. . Resíduos de frutos do mar: oportunidades potenciais para produção de materiais bioativos. In: WORKSHOP DE BIOMATERIAIS, ENGENHARIA DE TECIDOS E ORGÃOS ARTIFICIAIS, 6th, October 29-31, 2019, São Paulo, SP. Abstract... 2019.

    Abstract: Resíduos de frutos do mar: oportunidades potenciais para produção de materiais bioativos Resíduos de frutos do mar são fontes ricas em diversos compostos e materiais bioativos e anualmente, no mundo, milhões de toneladas destes resíduos (conchas, ostras, camarões, caranguejos, lagostas, mariscos, etc) são produzidos. No Brasil, cerca de 2 milhões de toneladas somente no Litoral Sul/SP. Com este problema ambiental, há grande geração de resíduos sólidos de atividades pesqueiras e/ou de maricultura,frequentemente despejados em terrenos baldios, aterros sanitários ou no mar. No entanto, eles embutem grande quantidade de elementos/compostos químicos valiosos (cálcio, quintina, pigmentos, proteínas), e poderiam ser usados para diversas aplicações na medicina, industrias farmacêuticas, alimentícias, energéticas, etc., Estes resíduos normalmente têm seus valores potenciais ignorados e o seu aproveitamento diminuiria a agressão ambiental e geraria renda aos maricultores e pescadores Neste trabalho, resíduos de frutos do mar foram calcinados para converter CaCO3 em CaO, sendo um dos catalisadores sólidos heterogêneos, altamente ativo, mais utilizados em reação de transesterificação de óleos vegetais para produção do biodiesel. Eles foram calcinados a 1000°C e usados em pó (100 a 200mesh). A caracterização antes e após calcinação foi por WDXRF (FRX por dispersão de comprimento de onda),. O teor de Ca era de 36,2% e de 98,8% de CaO, respectivamente. As propriedades catalíticas foram verificadas em testes de produção de biodiesel, em uma unidade reacional com micro-ondas do IPEN. O maior teor de éster metílico, em GC, obtido foi de 98%, em um teste de 11g de catalisador (P-300W; t-1h; T-65°C; 600rpm). As densidades ficaram dentro das especificações (850 a 900kg/m3) - 20°C. Com estes estudos, verificou-se que é possível aproveitar diversos tipos de materiais, empregando metodologias alternativas e mais conscientes, para proteção do meio ambiente.

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  • IPEN-DOC 26817

    FEDERICO, CLAUDIO A.; GONÇALEZ, ODAIR L.; PAZIANOTTO, MAURICIO T.; DIAS, ARTHUR F.; PRADO, ADRIANE C.M.; CALDAS, LINDA V.E. . A statistical evaluation on the cosmic radiation doses on aircrews flying over South America and Caribbean regions. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction There are substantial researches on the cosmic radiation doses received by aircrew on their typical fl ight workload. Most part of these studies was made by measurements onboard aircrafts of some specifi c companies in stablished routes. A recurrent question from countries over South America and Caribbean regions is related on the signifi cance of doses accumulated by aircrews over this region and if those magnitude justifi es a specifi c radiation protection procedure. Methods The evaluation was made by statistical analysis using CARI-6 aircrew radiation dose code and the data are derived from comprehensive records of registered fl ights performed in the South America and Caribbean airspace between 29,000 and 41,000 feet, performed from March 7 to 20, 2009. The analysis of this sample was composed of 80,548 route calculations totalizing 53,163 hours of real fl ights, by means of calculation of each track performed by aircrafts between aeronautic navigation waypoints. Results The analysis identifi es that the typical group of fl ight crew operating over this region receives mean dose rates ranging from 2.65 μSv/h to 2.95 μSv/h depending on the solar cycle. This distribution, integrated over typical workload from Brazilian aircrews results on annual doses ranging from 1.45 mSv to 1.67 mSv. Conclusions The results demonstrate that the typical aircrew fl ying over this region exceeds the annual radiation limit for public (1 mSv). The statistical analysis also shows that this is the case of more than 96% of the aircrew fl ying with this fl ight routine and workload. The presented results can be used by local authorities of countries over this region as a basis to evaluate the convenience on adoption the recommendation from ICRP Publication 132 regarding radiation protection recommendations for aircrews.

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  • IPEN-DOC 26816

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; ANDREETA, MARCELLO R.B.; YAMAGUSHI, YASMIM Y.; JIUSTI, JEANINI; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Evaluation of the FTIR technique for the linearity assessment of commercial soda-lime glass irradiated with gamma radiation. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction High dose dosimetry is one of the most important branches of everyday activities related to medical and industrial applications. Nevertheless, the use of materials that respond in a linear manner has advantages over nonlinear materials, since the dose calculation procedure in linear materials relies solely upon direct proportions to the delivered dose. The evaluation techniques are also important to identify the possible linear ranges, and the new Fourier-transform infrared spectroscopy (FTIR) technique has been used to this objective. This work aims to investigate the linearity response and its sensitivity, using mainly the FTIR technique. Methods Cubic samples of a soda-lime glass type with composition of Li2O.2B2O3 + 10 mol% of (0.25Li2O + 0.25La2O3 + TiO2) were irradiated with doses from 1 kGy to 12 kGy, using a 60Co Gamma-Cell system 220. The response was evaluated using the FTIR technique. Results The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR), with its loadings performing a linear regression; from the slope value, the sensitivity of the glass at the absorbed dose range was obtained. The PLSR technique showed, on the range of 1-12 kGy, that the soda-lime glass type presents linearity value of 0.8532 using just three components. The results of the linearity test were obtained for the FTIR technique. Conclusions The FTIR technique was applied to assess the linear behavior based of the glass spectrum, showing its usefulness to identify possible linear dose regions and also the overall sensitivity of the glass samples to dose. Therefore, the results obtained indicate a good linear response, showing therefore a potential use of this glass-soda lime type for radiation dosimetry in high doses.

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  • IPEN-DOC 26815

    PRADO, EDUARDO S.P. ; GONÇALVES, MAX F.S.; MIRANDA, FELIPE de S.; PETRACONI FILHO, GILBERTO; MASSI, MARCOS; POTIENS JUNIOR, ADEMAR J. . Plasma reactor to viabilize the volumetric reduction of radioactive wastes. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction According of the International Atomic Energy Agency – IAEA, nuclear waste, also known as, radioactive waste, is any material containing a higher concentration of radionuclides than those considered safe by the national authorities. In Brazil, there is a National Nuclear Energy Commission to regulate. These wastes can be generated in nuclear power plants, industries, hospitals and research institutes. To permanently dispose of these radioactive wastes of low and medium level of radioactivity safely and cost effectively, these should be transformed into the physical and chemical compounds suitable for radionuclides immobilization with maximum volume and exhaust gaseous reduction. Incineration is used as a treatment for a very wide range of wastes. Incineration itself is commonly only one part of a complex waste treatment system that altogether, provides for the overall management of the broad range of wastes that arise in society. The objective of waste incineration, in common with most waste treatments, is to treat waste so as to reduce its volume and hazard, whilst capturing (and thus concentrating) or destroying potentially harmful substances. The incineration of waste is one of the most widespread and effective technologies allowing considerably to reduce waste volume. In this scope, among the promising technologies for the radioactive waste treatment is the plasma technology that allows reducing substantially the waste volume after exposing them to temperatures above 2500ºC. In the planning and management of radioactive waste, the challenges related to plasma technology are presented as a motivation factor for the possible implantation of plasma reactors in nuclear plants and research centers with the objective of improving the process of radioactive waste treatment. In this way, this work aims to evaluate the use of plasma technology for the incineration of radioactive waste for volumetric reduction and immobilization of this waste. Methods In this work, a plasma reactor was used for waste incineration, and all reactor parameters (electric energy ranges, maximum arc current, maximum working voltage, air fl ow, maximum energy conversion effi ciency, average temperature of heated gas, heated enthalpy) was controlled based on literature. The experiment was carried out in the plasma reactor (laboratory scale) of LPP in the ITA, using plasma torch transferred arc and with gaseous argon oxidizing agent. The electrical and thermal characteristics of the auxiliary systems of the plasma reactor were obtained using transducers and thermocouples. The composition of the gases in the process was analyzed using mass spectrometer and spectrophotometer. Results The accuracy of the data was important to ensure good results in the process, which allowed the extraction of relevant information from the experiments performed. The volumetric reduction reached 92% in relation to the sample before being processed, with a peak temperature of 1800ºC. Although a larger amount of argon fl ow intensify the cooling of the inner wall of the reactor, and further promote the dilution of the plasma, the arc voltage increases, resulting in higher power operation. Conclusions In the present work a high effi ciency thermal transfer torch was characterized , able to validate the use of the plasma jet for the treatment of radioactive waste.

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  • IPEN-DOC 26814

    MATSUSHIMA, L.C.; VENEZIANI, G.R. ; SAKURABA, R.K.; CAMPOS, L.L. . Quality control in “Intensity Modulated Radiation Therapy-IMRT” using thermoluminescent dosimeters. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Quality assurance in radiation therapy included all actions for ensure the maximum dose for the target volume (tumour) and minimum dose for the healthy tissues. The use of thermoluminescent detectors for evaluation of the absorbed doses in treatments that involve the use of ionizing radiation is widespread and well established in clinical routine. The quality measures are employed to validate system performance, such as IMRT quality assurance (QA). An example for IMRT QA is the decision not to treat the patient if the comparison between a point-dose measurement and the planned value exceeds a predefi ned acceptance criterion (±5%). This work aimed the evaluation of absorbed doses with the use of thermoluminescent detectors (TLDs) of lithium fl uoride doped with magnesium and titanium (LiF:Mg,Ti) and a polymethylmethacrylate (PMMA) phantom in Intensity Modulated Radiation Therapy – IMRT planning. Methods In this study the PMMA phantom simulated a patient in treatment. The central cavity (rectangular format) was considered like target volume (tumour) and the others four cavities were considered like organs at risk. The TLDs were positioned inside the cavities; each cavity has an EVA mold for the positioning of TLDs.

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  • IPEN-DOC 26813

    CORREA, J.N.; PASCHUK, S.A.; BARRETO, R.C.; DENYAK, V.; SCHELIN, H.R.; NARLOCH, D.C.; DEL CLARO, F.; HASHIMOTO, Y.; MATIN, A.C.; SILVA, A.C.M.; ZAHN, G.S. ; SILVA, P.S.C. . Evaluation of the maximum emitting layer of Rn-222 in cementitious building materials. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction – Radionuclides present in construction materials are of interest in the view of environmental radioactivity. The limitations established have focused on the concentration of Ra-226 and the consequent exhalation of Rn-222. A physical/mathematical model developed at the Laboratory of Applied Nuclear Physics (LFNA/UTFPR) correlates the exhaled Rn-222 with the Ra-226 inherent to the material. The model considers the exhalation of Rn-222 by a plane surface that simulates exhalation in fl oors, walls and ceilings. Determination of the maximum emitting layer of Rn-222 that effectively exhales is important to support the model. The objective of this research is to determine the maximum emissive layer of Rn-222 that provides internal diffusion and exhalation of radon-222 in cementitious materials. Methods - Cylindrical samples were made of common cement paste and cement paste with sand of high Ra-226 concentration. The samples (thicknesses 1 to 5 cm) were sealed in order to ensure the exhalation of Rn-222 through one surface. Samples and diffusion chambers containing CR-39 solid-state detectors were inserted into a glass vessel. The samples/detectors were stored for 30 days. Subsequently, the detectors were chemically etched and the nuclear tracks in the CR-39 detectors were counted. Results – For each type of sample a curve was fi tted whose threshold indicated the maximum emitting layer. The results obtained on the samples of common cement paste indicated a maximum emitting layer of 2cm. For samples of cement paste with sand with high Ra-226 concentration, no threshold was observed, indicating that the maximum emitting layer is greater than 5cm. Conclusions - The maximum emitting layer thickness of Rn-222 of common materials determined by curve fi tting was 2cm. For materials with high concentration of Ra-226 there is an indication that the emitter layer is larger than 5cm. The obtained results subsidize the physical/mathematical model developed in the LFNA/UTFPR.

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  • IPEN-DOC 26812

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; MORAIS JUNIOR, PEDRO A.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Dosimetric characterization of high-linearity bone radiation detector exposed to gamma-rays. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction In radiation physics, the study of new alternative dosimeters is of interest on the growing branch of dosimetric characterization of solid-state dosimeters for radiotherapy applications in the Medical Physics fi elds. There are innumerous emerging techniques for reading and processing multivariate data to assess the possible linear behavior of dosimeters; such methods are the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component Regression (PCR) techniques. The goal of this work was to expose bone samples to high doses and to use the FTIR spectrophotometry technique to evaluate the sensitivity and linearity of the absorbed profi les using PLSR and PCR analyses. Methods Small cubes with size approximately of 0.5 cm3 composed the bone samples, used in this work. The samples were irradiated in triplicates, with absorbed doses of 10, 100, 250, 400 and 500 Gy using a 60Co Gamma Cell-220 system (dose rate of 1.089 kGy/h); afterwards, the absorbance spectrum of each sample was acquired on a Fourier Transform Infrared (FTIR) Spectrometer (Frontier/Perkin Elmer) with an optical step of 1 nm from 400 nm to 4000 nm. Results The absorbance for high sensitivity peaks was observed for each bone sample, at the 552 nm, 991 nm and 1650 nm wavelengths in decreasing magnitude. The PLSR and PCR techniques showed, on the range from 10 Gy to 500 Gy, for the calibration curves of the system, a linearity of 0.9432 and 0.9422 respectively, using just three components on both methods. Conclusions The results indicate an acceptable linear response, and therefore this material may be an interesting radiation detector.

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  • IPEN-DOC 26811

    VILLANI, D. ; RODRIGUES JUNIOR, O. ; DANTAS, B.M.; CAMPOS, L.L. . Dosimetric characterization of 3D printed phantoms at different infill percentage for diagnostic x-ray energy range. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction The use of 3D printing and fi laments commonly found commercially for development of phantoms has been investigated in recent years due to the cost of materials and improvements in the quality of printers. The application of this technique for radiation protection and dosimetry requires a complex study of the quality control and the interaction of printed materials with different radiation beams. The aim of this paper is to characterize 3D printed phantoms and printing set-ups for different infi ll percentages for diagnostic energy beams. Methods 3D printing performance was studied using the RAISE 3D PRO2 printer from IPEN for printing with PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene) fi laments. Printing characteristics such as repeatability, reproducibility, effective density by displaced water mass and porosity at 100% infi ll were studied. Plate samples of 8x8x1cm3 were printed and, using the Pantak Seifert irradiator with different x-ray qualities in the diagnostic energy range, the attenuation coeffi cients were obtained experimentally for different percentages of plates infi ll. Results By printing three identical samples for each print mode, the 3D printing system had a repeatability better than 1.0% for masses and average of 0.7% for the dimensions of the printed objects, obtaining the highest variations in small printed parts. Little to no porosity has been found on the printed pieces with 100% infi ll, giving to the printed objects the same density of the chosen fi lament. The attenuation coeffi cients were determined for the different beam qualities and it was verifi ed that the variation in the values decreases as the infi ll quality increases. Conclusions The results show that the printing system have excellent repeatability and print quality. The different printing modes characterized together with their attenuation coeffi cients for the x-ray beams will be studied and used in the development of new 3D printed phantoms in our institute.

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  • IPEN-DOC 26810

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Evaluation of transparent and black commercial soda-lime glass irradiated with gamma radiation. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction The linearity characteristic in radiation dosimetry presents a growing interest. Glasses have been applied to radiation high doses. The goal of this work was to expose transparent and dark commercial soda-lime glasses samples to high doses and to use the UV-Vis spectrophotometry technique for their evaluation. Methods Transparent and dark commercial soda-lime glasses with dimensions of 1 x 10 x 40 mm3 were irradiated with doses from 1 kGy to 10 kGy using a 60Co Gamma-Cell system 220, and then were evaluated with the UV-Vis technique. The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component Regression (PCR) techniques. Results The PLSR and PCR techniques showed, on the range of 1-10 kGy, for the calibration curves, of transparent and black commercial soda-lime glass, linearity values of 0.9432 and 0.9422 respectively using just three components on both methods. The spectra present a baseline variation (and maximum absorbance values) proportional to the absorbed dose received by the samples. These results show that it is possible to use the technique of UV-Vis to determine if the glass samples were irradiated or not. The color changes for transparent glass irradiated with absorbed doses from 1 kGy up to 10 kGy. This color variation in relation to absorbed dose indicates that the glasses may be used as YES/NO dosimeters. Conclusions The UV-Vis measurements may be useful in gamma radiation dosimetry, using the spectra of irradiated glasses; the highest linearity was shown in order respectively for transparent and black commercial soda-lime glass; the glass samples changed their coloration proportional to the absorbed doses, and they may be used as Yes/No detectors and as high-dose dosimeters. The results indicate a good linear response and the radiation detectors present potential use for radiation dosimetry in high doses.

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  • IPEN-DOC 26809

    GONCALVES, J.A.C. ; MANGIAROTTI, A.; ASFORA, V.K.; KHOURY, H.J.; BUENO, C.C. . Dosimetric characterization of thin diodes in an electron beam facility for radiation processing. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction: Silicon diodes have been employed as relative dosimeters in clinical photon and electron beams. However, they are prone to radiation damage that produces a drop of their current sensitivities with increasing accumulated doses. This effect is attributed to the decrease of the minority carrier diffusion lengths which diminishes the sensitive volume of the diode. Theoretically, it is possible to mitigate the decay of the current sensitivity by choosing diodes with thicknesses smaller than the lowest minority carrier diffusion lengths anticipated for the foreseen accumulated dose. This surmise has been followed up in this work by evaluating the response of thin diodes (SFH00206K) for the dosimetry of electron beams used in radiation processing. Methods: The diode with 10 μm of depletion layer at 0V was produced on n type Si wafers of 220 m thickness. As a dosimeter, the device was housed in a probe and connected to an electrometer to be operated in short-circuit current mode without bias voltage. To carry out the irradiation, the probe was placed on a conveyor belt that crosses the radiation fi eld of a 1.5 MeV electron beam. Results: The currents were registered as a function of the exposure time for dose-rates within 2-8 kGy/s and accumulated doses up to 350 kGy. The dosimeter was characterized with respect to the linearity between current and dose-rate, repeatability and reproducibility of the current signals. Its lifespan was investigated, particularly addressing the stability of the current sensitivity factor with increasing absorbed doses. The measurements were benchmarked against calculations of the current taking into account the fraction of the electron energy deposited in the active volume of the diode, the dose-rate, and the values of diffusion lengths. Conclusion: All experimental data so far obtained prove that this diode can be used in electron beam dosimetry. Furthermore, a fair agreement was found between theoretical and experimental results.

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  • IPEN-DOC 26808

    POLO, IVON O. ; SANTOS, WILLIAM S. ; CALDAS, LINDA V.E. . An extrapolation chamber for the establishment of a primary radiation standard in 85Kr and 147Pm beta radiation beams. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction At the Calibration Laboratory (LCI) of the IPEN/CNEN, studies are in development on the establishment of the Böhm extrapolation chamber model 23392 as a primary standard system for the dosimetry and calibration of beta-radiation sources and detectors. This chamber was already characterized at the LCI in 90Sr/90Y beams using two different entrance windows: one of aluminized Mylar and another of Hostaphan. This extrapolation chamber was characterized in 85Kr and 147Pm beams. All tests were carried out with the reference 90Sr /90Y source, for comparative purposes. Methods A Keithley model 6517B electrometer was used for the measurements. The utilized radiation sources are part of the Beta Secondary Standard BSS2. Moreover, the Monte Carlo code MCNP5 was used to determine the absorbed dose rates and to compare them with the experimentally determined dose rates and with those from the PTB calibration certifi cate. Results Saturation curves, ion collection effi ciency, ion recombination, polarity effect, response stability, real null depth, linearity of response, variation of response as a function of sourcedetector distance, extrapolation curves, correction factors and absorbed dose rates were obtained. The ion collection effi ciency was greater than 99%; the ionic recombination was less than 1%, and the polarity effect was greater than 1%. The stability of the response was lower than 0.15% for the repeatability test, and it was less than 0.36% for the reproducibility test. The difference between the experimental absorbed dose rates and those from the Monte Carlo model, compared to those from the calibration certifi cate, was less than 1.9% for all sources. Conclusions All results of the performed tests are within the limits of the international recommendations. The results for the 90Sr/90Y source were in the good agreement with previous works performed at LCI. These results are suitable for the establishment of a primary standard for beta radiation.

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  • IPEN-DOC 26807

    OTERO, ANDRE G.L. ; MARUMO, JULIO T. ; POTIENS JUNIOR, ADEMAR J. . Applying deep-learning in gamma-spectroscopy for radionuclide identification. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Neural networks, particularly deep neural networks, are used nowadays with great success in several tasks, such as image classifi cation, image segmentation, translation, text to speech, speech to text, achieving super-human performance. In this study we explore the capabilities of deep learning on a new fi eld: gamma-spectroscopy analysis. Using a well-known deep neural network architecture with gamma spectroscopy data, we successfully identify the radionuclides (Am-241, Ba-133, Cd-109, Co-60, Cs-137, Eu-152, Mn- 54, Na-24 and Pb-210) contained in several experiments. This neural network is also capable to identify different mixed radionuclide in the same source, demonstrating that deep neural networks can be successfully applied on gamma-spectroscopy analysis. Methods Using a HPGe detector to acquire several gamma spectra, from different sealed sources, we created a dataset that was used for the training and validation of the neural network. We created our deep neural network using python as programing language, alongside with Keras, a deep learning framework. Applying the VGG19 network architecture, except by the last layer which using softmax as activation function, we used sigmoid in order to allow classifi cation of not mutually exclusive classes in the same instance. Results After 250 epochs of training the classifi cation error on the training and test datasets reached a minimum, the same occurred with accuracy. As a fi nal test we used a spectrum from a triple sealed source, containing Am-241, Cs-137 and Co-60. As this kind of data was never seen by the network before we expect that the network generalizes well and correctly classify the spectra as containing the three isotopes. When applying the new data, the model correctly classifi ed the spectra as containing the tree radionuclide. Conclusions The model successfully classifi es different spectra with different radionuclides and his performance is good on never seen before data (the triple source sealed) demonstrating that deep learning can be used on a new domain.

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  • IPEN-DOC 26806

    SAVI, MATHEUS; BERTONCINI, MARCO A.; POTIENS, MARIA da P.A. . Commercial filament testing for use in 3D printed phantoms. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction With the popularization of 3D printing, many areas of knowledge are using this technology to create products and diminish costs, even in health segment. Commercial phantoms are expensive and hard to obtain in development countries. As alternative, 3D printed phantoms can be the way to produce inexpensive and reliable simulators aimed for dosimetry and teaching. That said, the objective of this study is to determine which of the available commercial fi laments can be used in 3D printing to mimic human tissue for use in 3D printed phantoms. Methods Fourteen 3D printing fi laments (ABS, ABS premium, PLA, PLA+Bone, PLA+aluminum, PLA+brass, PLA+cooper, SILK, HIPS, PETG, PVA, Wood, TPU and TPE) commercially available in Brazil had their attenuation tested, using computed tomography. Each material was printed as 2 centimeters edge cube with rectilinear pattern and 60, 80 and 100 percent infi ll. The cubes were scanned in a Philips CT Brilliance 6 with 120 kV, 200 mA, 2mm slices and standard reconstruction. At the center of each cube, an ~ 120 mm² region of interest were set to measure the mean Hounsfi eld Unit (HU) and the standard deviation value. For each material a graphic was plotted and the curve equation determined. Results The HU of the tested materials ranged from -516,2 ± 7,3 to 329,8 ± 18,9. All human tissues could be mimetized with these materials, except bone (mainly cortical bone). Considering the curve equation, the most promising fi lament was PLA+Cooper, due to the multiple infi ll confi guration that allows the resulting HU range to represent from adipose and skin tissue to marrow bone. With a two extruder printer may be possible add lung tissue to the model and make a 3D phantom more complex and accurate. Conclusions With these tested materials, is possible to construct various phantoms, simulating a wide range of tissues. However, any simulator with cortical bone is impaired because none fi lament achieve the required HU value (at least over 800 HU).

    Palavras-Chave: 3d printing; phantoms; fabrication; filaments; radiology; computerized tomography

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  • IPEN-DOC 26805

    NASCIMENTO, ERIBERTO O.; BECATTI, MATHEUS J.P.; ANTONIO, PATRICIA L. ; VIEIRA, SILVIO L.; OLIVEIRA, LUCAS N. de ; CALDAS, LINDA V.E. . Quality control of solar protection films via design of experiments. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Solar radiation reaching the earth surface is broadly divided into infrared, visible and ultraviolet radiation (UVR). Individual dosimetry and monitoring of the sun rays in humans and environments is of interest since in homes, shops and cars the effects of UVR radiation can bring irreparable damage to the skin and eyes. The effi cacy of solar protective fi lms has been recognized as an important public health product. The objective of this work was the quality control of solar fi lms using the UV-Vis spectroscopy technique via 2k Experimental Factor. Methods Four types of solar protective fi lms were tested: G05, G20, G35 and WB (Windom Blue), which follow the blocking of UVR rays by 95%, 80%, 65% and 0% (76% transparent). The samples had dimensions of 1.0 x 3.0 cm2 and the readings were taken on a GENESYS™ 10S UV-Vis Spectrophotometer with an optical step of 1 nm from 190 nm to 400 nm. The absorbances were used in a 2k Experimental Factor, in which the four fi lms were read individually and also with overlap (two fi lms together). It was possible to obtain results of all the interactions among the fi lms, with or without overlap. Results The results about the absorption of the sunscreen fi lms were modeled from the 2k Experimental. This factor indicates that the best regions of the spectrum are blocked and/or where they produce a better quality control of these materials. The region studied in this work was where the ultraviolet radiation dosimetry can be of interest. The proposed spectrophotometric method is rapid, simple and cost effective for the evaluation on quality control of protection fi lms. Conclusions The results provide information on ultraviolet radiation and they can be useful for the medical physics community. The proposed methodology may be useful as a rapid quality control tool. It can be used during the production process, in the analysis of the fi nal product, and can offer important information for the scientifi c community.

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  • IPEN-DOC 26804

    ROSSI, MARIANA C.; BAYERLEIN, DANIEL L.; KRIECK, ANDRE M.T.; BRANDÃO, JAQUELINE de S.; PFEIFER, JOÃO P.H.; ROSA, GUSTAVO dos S.; STIEVANI, FERNANDA de C.; MARTINEZ, LUIS G. ; SAEKI, MARGARIDA J.; ALVES, ANA L.G.. Influence of space holder on the biocompatibility of Ti-34Nb-6Sn alloy prepared by powder metallurgy. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Development of metallic materials for denistry and orthoapedic area have been increasing, due to in world life expectancy and the significantly numbers of accide nts. Due to problems of failure in available commercial materials implantation, as well as the discomfort of patient because the high elastic modulus, these devices need to be improved or news implants should be sought. This study was intended to develop a porous alloy, Ti-34-Nb-6Sn/Mg wich can help the ingrowth bone tissue when implanted, by the powder metallurgy. After the milling powders in the high energy mill, were compacted and sintered. Both, powders and sintered materials were chacarterized by X-ray Difraction (XRD), Scanning Electron Microscopy (SEM) and semi-quantitative compositional analysis (EDS). The apparent porosity was measured through the Arquimed’s Method. The toxicity this material was evaluated by MTT assay, using the equine mesenchemal stem cells derivated of bone marrow (bmMSC) according to ISO 109935. The bmMSCs morphological analysis in contact on the material surface using SEM. The Mg evaporation was confirmed by EDS and XRD after sintering. The XRD indicate there is predominantly beta phase than alpha. The apparent porosity was higher in alloy with Mg space holder. The materials do not presented particular cytotoxic in direct and indirect contact. Metallurgic powder tecnhique promoted effectively macropores formation in Ti-34Nb-6Sn/Mg alloy, wich possibly further bmMSCs adhesion.

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  • IPEN-DOC 26803

    SAEKI, MARGARIDA J.; GARCIA, JOÃO I.M.M.; FERNANDES, CELIO J.C.; ROSSI, MARIANA C.; SILVA, WILLIAM de M.; MARTINEZ, LUIS G. ; ZAMBUZZI, WILLIAN F.. Characterization of titanium surface modified by calcium titanate. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Coatings based on apatite and others that contain calcium play an important role for the osseointegration with the implant. It is believed that released calcium induces a specific biological response to the living tissue establishing a stable chemical bonding between formed bone and implants. The mechanical anchorage of implants also depends on the surface structure and morphology. In this work, the titanium surface was modified by calcium titanate, which was deposited by sol-gel method combined to the dip coating technique followed by heat treatments. Two different emersion rate (5 and 10 cm/min) were used as well as the number of coatings were varied. The temperature of this treatment was established based on the results of the thermal analysis (TG/DTA). The surfaces were characterized by X-ray diffractometry (DRX), Scanning Electron Microscopy (SEM) and water contact angle measurement. The corrosion behavior of modified surfaces was evaluated by electrochemical method (polarization curves) in balanced saline Hanks solution. Finally, biological test was carried out by the analysis of cellular viability and adhesion of MC3T3-E1 (subclone 4), mouse pre-osteoblastic cells (ATCC CRL-2593), using MTT and crystal violet assays, respectively, after 24h incubation at 37oC in 5% CO2 atmosphere. The coating consists of anatase TiO2 (PDF 21-1272) and calcium titanate (CaTiO3, PDF 43-226). SEM analysis showed that homogeneous films with 0.8μm of thickness are provided when they are prepared by only one immersion and that the films increase the resistence to corrosion. The coating increases the wettability as the water contact angle decreases from 90o±10o for cp Ti (low interstitial titanium) to 34 o±5o. The biological test shows that the modifications do not interfere on the osteoblast viability and adhesion, however, the morphological analysis of preosteoblasts cultured on the modified Ti-surface by SEM shows that the coatings promote a cell spreading.

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  • IPEN-DOC 26802

    SILVA, ANDERSON M.B.; JUNOT, DANILO O. ; SOUZA, LUIZA F.; SOUZA, DIVANIZIA N.; CALDAS, LINDA V.E. . Caracterização do CaSO4:Tb,Ag para dosimetria OSL. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 24., 21-24 de agosto, 2019, Santos, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2019.

    Abstract: Embora a dosimetria por OSL seja bem conhecida, o uso dessa técnica tem sido pouco difundido devido à limitação de materiais. Conforme resultados da literatura, a prata como co-dopante em matrizes de CaSO4 dopado com terras raras proporciona um aumento da intensidade das emissões luminescentes em comparação aos materiais sem a prata. Sendo assim, como não há relatos sobre a caracterização estrutural e dosimétrica do CaSO4:Tb com a incorporação de prata, a proposta do presente trabalho foi produzir e caracterizar policristais de CaSO4 dopado com térbio e co-dopado com óxido e nanopartículas de prata. Os fósforos apresentaram uma curva típica de decaimento exponencial de OSL. As amostras de CaSO4:Tb,Ag(nanopartícula) apresentaram sensibilidade OSL cerca de 4 vezes mais intensa em comparação com CaSO4:Tb,Ag(óxido). Ambas as amostras apresentaram curva dose resposta linear na faixa de dose observada e limite inferior de detecção (LID) de 9 mGy para o CaSO4:Tb,Ag(nanopartícula) e 32 mGy para o CaSO4:Tb,Ag(óxido).

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  • IPEN-DOC 26537

    PRESTES, JOAO C.A. ; POTIENS, MARIA da P.A. ; XAVIER, MARCOS . Caracterização de um sistema irradiador utilizado em radioterapia para calibração de dosímetros clínicos. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 24., 21-24 de agosto, 2019, Santos, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2019.

    Abstract: Este trabalho apresenta as etapas de adequação e caracterização de um irradiador de 60Co, que era utilizado para tratamento para que seja utilizado em procedimentos de calibrações de dosímetros clínicos utilizados em radioterapia. Foi realizado a adequação de um sistema irradiador doado ao Laboratório de Calibração do Ipen e a caracterização do feixe e do campo de radiação, de acordo com as recomendações do guia da AIEA (TRS 469, 2009). Para a instalação do novo irradiador, foi realizada uma adaptação na atual sala de calibração para acomodar o cabeçote na posição de calibração. Um suporte foi confeccionado para o seu posicionamento. Na sequência foi necessária a correção no sistema de colimação que apresentou falhas na sua utilização. Para a caracterização do feixe de radiação foram realizados os testes iniciais de uniformidade do campo de radiação determinando o tamanho e o centro do feixe de radiação. Utilizando uma câmara de ionização de pequeno volume foi encontrada uma uniformidade maior do que 90% tanto no sentido vertical como no horizontal, para um feixe de radiação de 8 x 8 cm. As medições para a determinação das taxas de kerma no ar realizadas demonstram que o sistema está pronto para ser utilizado na calibração.

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  • IPEN-DOC 26801

    SANTANA, TATIANA D.; ROSSI, WAGNER de ; BARBOSA, PATRICIA A.; CARNEIRO, MARCELO B.. Caracterização por microscopia óptica 3D de ferramenta de corte texturizada por laser de femtossegundos. In: COLÓQUIO DE USINAGEM, 23., 12-13 de dezembro, 2019, Uberlândia, MG. Anais... Uberlândia, MG: Universidade Federal de Uberlândia, 2019.

    Abstract: As superfícies possuem características que podem impactar no coeficiente de atrito, na adesão de filmes e células, na retenção de fluidos lubrificantes, em aspectos ópticos, químicos e mecânicos. Dessa forma, muitos parâmetros foram criados com intuito de caracterizar as superfícies após um determinado processo de manufatura. Em geral, os equipamentos utilizados para realizar tal tarefa são categorizados em com e sem contato com as superfícies em avaliação. Nos processos de usinagem convencional, condições severas de atrito na interface cavaco ferramenta aumentam o desgaste da ferramenta e reduz o seu tempo de vida. A habilidade do fluido de corte penetrar na zona de corte pode ser melhorada pela texturização da superfície de saída da ferramenta. Neste trabalho, uma ferramenta de corte foi texturizada com o uso de um laser de femtossegundos, e caracterizada com o uso de um microscópio óptico 3D com tecnologia confocal que garante medições precisas da topografia, sem contato.

    Palavras-Chave: texture; lasers; cutting tools; topography

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  • IPEN-DOC 26800

    SILVA, J.C.M.; NTAIS, S.; RAJARAMAN, V.; ANTONIASSI, R.M. ; SPINACE, E.V. ; BARANOVA, E.A.. The catalytic activity of PtRu nanoparticles for ethylene glycol and ethanol electrooxidation in alkaline media. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 266-266.

    Abstract: The use of excessive fossil fuels has resulted in harmful effects on the environment and potentially human health. In this sense, direct alcohol fuel cells DAFCs are promising energy producing devices. Ethanol and ethylene glycol are appealing fuels for DAFCs due to their lower toxicity and high theoretical energy density, 8.01 kWh kg−1 and 5.2 kWh kg−1, respectively [1,2]. In this study, the carbon-supported PtRu nanoparticles with atomic ratios of Pt:Ru of 100:0, 90:10, 70:30 and 50:50 for ethanol and ethylene glycol electrooxidation in alkaline media, was investigated. The nanoparticles were synthesized using sodium borohydride method with 20 wt% of metals loading on carbon [1]. X-ray diffraction (XRD) analysis revealed that Pt and PtRu electrocatalysts have face centered cubic (fcc) structure and suggests the alloy formation for all PtRu/C materials, which was further supported by the X-ray Photoelectron Spectroscopy (XPS). According to transmission electron microscopy (TEM) the nanoparticle mean sizes were 7.3 nm, 5.7 nm, 5.2 nm and 5.1 nm for Pt/C, Pt90Ru10/C, Pt70Ru30/C and Pt50Ru50/C, respectively. Electrochemical measurements carried out in mol L-1 KOH + mol L−1 alcohol solution (ethanol and ethylene glycol) in a conventional three-electrode electrochemical cell (glassy carbon was used as work electrode and a platinum foil and a Hg/HgO were used as the counter and reference electrodes, respectively) demonstrated that the addition of Ru to Pt enhances the catalytic activity towards ethanol and ethylene glycol electrooxidadion in alkaline media. The catalyst of Pt50Ru50/C composition showed the lowest onset potential for ethanol and ethylene glycol electrooxidation (by Cyclic voltammetric), which are 160 mV and 70 mV lower than for Pt/C, respectively. Furthermore, this catalyst outperformed Pt/C and other PtRu/C compositions in chronoamperommetric and direct alcohol fuel cell (DAFC) experiments. DAFC experiments using Pt50Ru50/C as anode had the power density 40% and 14 % higher than using Pt/C for ethanol and ethylene glycol, respectively. The enhancement of the catalytic activity might be related to the high amount of oxides species on the Pt50Ru50 electrocatalysts surface, which could form Ru-OH at low potential and also due to the electronic effect of PtRu alloy that weakens the adsorption strength of poisonous intermediates from reactions [3].

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  • IPEN-DOC 26799

    BIANCOLLI, A.L.G.; LOPES, T. ; PAGANIN, V.A.; TICIANELLI, E.A.. Electrocatalysts and membranes for using in PEMFCs and AEMFCs fed by contaminated hydrogen. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 417-417.

    Abstract: Catalytic ethanol dehydrogenation has been proposed as a promising method to produce H2 without CO and CO2.¹ However, the dehydrogenation generates other types of organic by-products such as ethyl acetate, acetaldehyde and leaves unreacted ethanol that can cause power losses in the fuel cell. To make this technology accessible, fuel cells performances must be improved. In this context, we studied the influence of the main contaminants present in the hydrogen produced by the catalytic dehydrogenation of ethanol on the performance of proton exchange membrane fuel cells (PEMFCs) and anion exchange membrane fuel cells (AEMFCs). Investigations comprised the elucidation of the processes and reactions involved in the corresponding electrode systems, as well as the phenomena governing the electrochemical performance in the alkaline and acidic media, and in the absence and in the presence of the by-products. For the AEMFCs, the research initially involved the syntheses of ionomers and membranes and the optimization of their performances in single cells, using pure hydrogen and conventional electrocatalysts (Pt-Ru/C in the anode and Pt/C in the cathode).² However, due to the chemical instability when exposed to the contaminants, these materials seem to undergo degradation, leading to almost total and irreversible losses of the cell performance. A positive fact was that AEMs showed much less crossover of contaminants from the anode to the cathode. Through analyses by different techniques, it was found that unreacted ethanol is the main poison in the case of PEMFCs, with acetaldehyde and ethyl acetate having minor contributions. Different anodic and cathodic catalysts were tested in order to obtain better fuel cells performances, such as Pt-Sn/C, Pt- W/C, Pt-Co/C, Pt-Cr/C and Pt/C (Fig. 1). Also different types of membranes were tested (Nafion® 115, 117, and 212). The best result was achieved when the Pt- Co/C catalyst was used at the cathode (with Pt/C at the anode), for which the loss of power density was only 20% compared to a cell fed by pure H2 and with Pt/C on both electrodes (working at 0.7 V).

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  • IPEN-DOC 26798

    SILVA, R.P. ; SOUZA, R.F.B. de ; SANTOS, C.M.G. ; SILVA, A.J. ; SANTIAGO, E.I. . Development of non-fluorinated membranes based on PBI for application in high temperature fuel cells (HT-PEM). In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 460-460.

    Abstract: Most of Proton Exchange Membrane Fuel Cells (PEMFCs) use the Nafion as electrolyte, which has a limitation in the operating temperature. Usually, these cells operate up to 80°C since the proton conduction is dependent on water molecules carriers. The increase in the operating temperature of a PEMFC cell is desired due to the contribution of the temperature in the acceleration of the electrochemical reactions, which are thermoactivated processes. In the context of searching alternative polymeric electrolytes, PBI (polybenzimidazole) membranes have been considered a promising membrane for high temperature operating PEMFC (HT-PEMFC) due to the combination of satisfactory proton conduction in conditions of low relative humidity (RH) and excellent thermal stability. Pure PBI membranes were prepared by casting a solution of PBI / N, N'-dimethylacetamide (DMAc) and doped with phosphoric acid at different times (1, 3, 5, 7 10 and 15 days). Each membrane was evaluated in Fuel Cell tests, doping level and online Raman tests in order to determine effects of doping level, chemical degradation and fuel cell performance. The electrodes were optimized by studying different catalytic layer composition and the cell tested at different operational conditions.

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  • IPEN-DOC 26797

    GUIMARÃES, V.P.; NANDENHA, J. ; FATIBELLO-FILHO, O.; NETO, A.O. ; VICENTINI, F.C.; ASSUMPÇÃO, M.H.M.T.. Development of nanomaterials for formate electrochemical oxidation aiming sustainable energy generation. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 436-436.

    Abstract: The world energy system is highly depended of fossil fuels, which is not sustainable [1]. Thus, the use of alternative energy is crucial and fuel cells are being considered good options. In this context, this work aimed to develop electrocatalysts based on palladium nanoparticles (PdNPs) supported on the physical mixtures of carbon (Vulcan XC72) and titanium dioxide (P25) toward formate oxidation in alkaline medium and its application in formate fuel cells. The materials were synthesized by the borohydride reduction method [2] with 20% (m/m) of metal loading and in two batches. In the first batch, the PdNPs were reduced in the physical mixture of carbon (C) and titanium dioxide (TiO2), in different proportions of C and TiO2, identified as Pd/(C+TiO2), while in the second one, the PdNPs were reduced only in TiO2 with later incorporation of C which were identifies as Pd/TiO2-C. On both batches, the ratios between C and TiO2 used were 75:25, 50:50 and 25:75 (m/m). A reference material, complied of PdNPs supported just on C (Pd/C) was also prepared. All materials were characterized by X-ray diffraction, showing peaks of the face-centered-cubic (fcc) structure of the Pd, as well as TiO2 peaks of anatase and rutile phases. Transmission Electron Microscopy (TEM) were also evaluated showing an average particle size between 3 and 8 nm. Electrochemical experiments considering voltammetry and chronoamperometry showed that the materials with PdNPs reduced in the TiO2 (Pd/TiO2-C) were more promising when compared to Pd/(C+TiO2), and among them Pd/TiO2-C 75:25 presented the highest current observed in chronoamperometry. Comparing the Pd/(C+TiO2) materials, the Pd/(C+TiO2) 50:50 presented the highest current. Taking into account single cell experiments, although the electrochemical results evidenced the improvement toward formate with PdNPs deposited firstly in the TiO2, the fuel cell tests showed the opposite, presenting the best cell efficiencies with Pd/(C+TiO2) materials, where Pd/(C+TiO2) 75:25 (ratio between C and TiO2) was the best material with the highest power density obtained. This fact can be explained by the higher conductivity of C, in a higher proportion, coupled with the small amounts of TiO2, which provides oxygenated species that facilitate the formate oxidation.

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  • IPEN-DOC 26796

    ZAMBONI, CIBELE B. ; ALMEIDA, MATEUS R. de ; MEDEIROS, JOSE A.G. de. Análise de zinco em sangue de corredores de longa distância / Zinc analysis in blood of long-distance runners. In: CONGRESSO BRASILEIRO DE CIÊNCIAS DO ESPORTE, 21st; CONGRESSO INTERNACIONAL DE CIÊNCIAS DO ESPORTE, 8th, September 15-20, 2019, Natal, RN. Resumo expandido... Porto Alegre, RS: Colégio Brasileiro de Ciências do Esporte, 2019.

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  • IPEN-DOC 26795

    ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. ; MORALLES, MAURICIO . Evaluation of peak-fitting software for gamma spectrum analysis. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 42.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 40., 1-5 de setembro, 2019, Campos do Jordão, SP. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2019.

    Abstract: In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width, for instance, are associated with each peak of each spectrum. Theres a huge choice of computer programs that perform this type of analysis, and the most commonly used in routine work are the ones that automatically locate and fit the peaks; this fit can be performed in several different ways - the most common are either to fit a Gaussian function to each peak or simply to integrate the area under the peak, but some software go far beyond and include several small corrections to the simple Gaussian peak function, in order to compensate for secondary effects. In this work several gamma-ray spectroscopy software are compared in the task of finding and fitting the gamma-ray peaks in spectra taken with some calibrated standard sources. The results allow for a discussion on the performance of each software in the tasks of identifying and determining the correct area of the gamma-ray peaks, as well as on the advantages and difficulties in using automatic programs when comparing with a manual peak-fitting software, used as reference.

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  • IPEN-DOC 26540

    ARAUJO, LEANDRO G. de ; WATANABE, NAOMI ; SILVA, THALITA T. ; TEIXEIRA, ANTONIO C.S.C.; VELOSA, ADRIANA C. de; MARUMO, JULIO T. . Oxidative degradation of organic compounds from sludge by ozonation: study of process. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 45th, March 3-7, 2019, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2019. p. 1-6.

    Abstract: This study investigates the performance of the ozonation process in the treatment of petroleum sludge from an offshore production platform situated in Brazil. The effect of operating conditions is studied such as the phase to be treated and the sludge/water ratio. Total organic carbon content increased in O2 and O3 experiments, mainly because of the mixing factor. The decrease of sludge mass was observed in a situation of forced mixing and with only ozone flow. The liquid phase indicated a high TOC value, but very low radioactive activities, whereas the solid phase did not present detectable TOC amounts but significant values of radioactive activity. More experiments and analyzes will be carried out to obtain more relevant results for future discussion.

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  • IPEN-DOC 26794

    ZAMBONI, CIBELE B. ; GIOVANNI, DALTON N.S. ; MIURA, VINICIUS T. ; GOMEZ, MONICA R. . Identificação de processos fotográficos utilizando a técnica de FRX. In: SIMPOSIO LATINOAMERICANO DE FÍSICA Y QUÍMICA EN ARQUEOLOGÍA ARTE Y CONSERVACIÓN DE PATRIMONIO CULTURAL, 7th, September 9-13, 2019, Ciudad de México, México. Abstract... Ciudad de México, México: Universidad Nacional Autónoma de México, 2019. p. 7-7.

    Abstract: O conhecimento da composição elementar de artes gráficas é de grande interesse para investigações de caráter histórico-artístico na medida em que possibilita identificar o processo de produção, a época de sua manufatura e, em alguns casos, sua procedência. Nos últimos anos, no Brasil, essas investigações têm adquirido relevância e estão sendo empregadas em acervos fotográficos pertencentes a museus, galerias de artes e a colecionadores particulares. As primeiras fotos tomadas em solo brasileiro datam de 1840 época da daguerreotipia. Desde então, com seu aperfeiçoamento, a fotografia tomou lugar de relevância cultural e viabilizou a geração de acervos particulares, sendo que muitos necessitam de devida caracterização, afim de situar o “objeto” dentro do contexto de sua própria época, além de agregar informações que auxiliem sua conservação e preservação. Atualmente a peritagem de obra de arte está crescendo no Brasil, em decorrência, estas informações podem agregar também valor econômico às produções gráficas. No presente estudo, o material de estudo compõe duas coleções fotográficas: uma com foco na arquitetura paulistana, e outra retratando personalidades do meio artístico. São acervos particulares cuja data e o processo de produção não são conhecidos. As análises de Fluorescência de Raios X por Dispersão de Energia (FRXDE) foram realizadas Laboratório de Espectroscopia e Espectrometria das Radiações (IPEN/CNEN-SP, Brasil), utilizando espectrômetro portátil de FRX da Amptek® com alvos de prata (Ag) e ouro (Au). Este instrumental é constituído por um detector de Silício Drift XR-100SDD (25 mm2 x 500 μm) com janela de Berílio (12,5 μm), acoplado a um pré-amplificador, um processador de pulso digital e multicanal. A condição de excitação foi estabelecida por 5 μA e 30 kV com tempo de contagem de 120 s. A análise elementar da coleção referente à arquitetura paulistana evidenciou o uso papeis com revestimento barita, muito utilizado por fotógrafos profissionais e amadores entre 1889-1930, evidenciam que essas fotos foram registradas entre o fim do século XIX e início do século XX. No que diz respeito ao acervo dos retratos, foi identificado o processo de cianotipia, evidenciado pela coloração azul das fotos (devido ao emprego sais de ferro como substância fotossensível), muito popular nas últimas décadas do século XIX [1,2]. Os resultados disponibilizados pela técnica de FRXDE permitiram situar a época e os processos fotográficos empregados. Essas informações contribuem para valorização desses acervos além de fornecer subsídios para o correto armazenamento e preservação.

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  • IPEN-DOC 26793

    BOIANI, N.F. ; SILVA, T.T. ; BORRELY, S.I. . Toxicity assessment of caffeine, fluoxetine and their mixture on Daphnia similis: acute and cronic effects. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 13th, September 15-18, 2019, Cartagena, Colombia. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry, 2019. p. 109-109.

    Abstract: Emerging pollutants have already become a global problem, and they have been detected in dozens of countries, including Brazil. Even at very low concentrations, most of the emerging compounds are able to induce changes into biochemical system of aquatic organisms and they have also been reported as negative products to human health. Pharmaceuticals are considered as emerging contaminants detected in estuarine environment, in wastewater treatment facilities, lakes and rivers and even in sea waters. Generally the pharmaceuticals are detected among many other compounds into the ecosystem. The interaction of mixtures of contaminants is an important issue to be considered in monitoring programs as well as the negative effect to aquatic biota. The aim of the present paper was the assessment of toxic effects of pharmaceuticals exposed to Daphnia similis crustacean, individual and combined mixture of caffeine and fluoxetine. Caffeine (CAF) is a stimulant with cardiac, cerebral, diuretic and respiratory effects while Fluoxetine (FLX) is a selective serotonin re-uptake inhibitor, widely prescribed as antidepressant, (also known as Prozac®). The juveniles of D. similis were exposed separetaly to both caffeine (100mg/L) and to fluoxetine (20mg/L), and to a mixture of both (50mg/L caffeine and 20mg/L fluoxetine). Several experimental trials of acute immobilization test were performed. EC50 values ranged from 29,7 to 31 mg/L-1 for caffeine, and from 1.0 to 1.4 mg/L-1 for fluoxetine. Antagonistic effects of binary mixtures (EC50 = 15.2%) were observed. A chronic reproduction test was performed for the mixture of pharmaceuticals. We observed effects on D.similis survival, after 5 days. The mixture led to decrease of 72% in the reproduction, in maximum concentration (2.5% of the mixture – CAF 50ppm + FLX 20ppm). Concerning the importance of assessing toxicity the elected pharmaceuticals concentration were higher than those detected in the envinroment. These results may be incorporated into risk assessments analysis in order to protect sensitive aquatic ecosystems more effectively.

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  • IPEN-DOC 26792

    TOMINAGA, F. ; BOIANI, N.F. ; SANTANA, N.D.; BORRELY, S.I. . Acute toxicity assessment for binary and tertiary mixtures containing fluoxetine, propranolol and diclofenac to microcrustacean and zebrafish embryos. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 13th, September 15-18, 2019, Cartagena, Colombia. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry, 2019. p. 111-112.

    Abstract: Pharmaceuticals are essential for treatment and prevention of several diseases and for the maintenance of human and animal’s life quality. Due to the increasing use of pharmaceuticals worldwide, many actives substances are currently detected in μg.L-1 and ng.L-1 in different environmentals matrices such as surface water, ground water, soil and sediment. Many of these emerging pollutants are recalcitrant to biological treatment process in WWTPs and they may cause ecotoxicological effects on organisms and also possible to reach the human food chain. Pharmaceuticals are frequently detected as mixtures and may induce toxic effects to aquatic organisms, producing synergistic, additive or antagonistic toxic effects. Fluoxetine hydrochloride (FXT) is a selective serotonin reuptake inhibitor, prescribed as an antidepressant. Propranolol (PRP) is a beta-adrenergic blocker widely prescribed for the treatment of cardiovascular diseases and diclofenac sodium (DIC) is a non-steroidal anti-inflammatory drug, often recognized as the “world’s most popular pain killer”. These compounds are worldwide used for healthy treatment and also often detected in aquatic environments. This work aims to assess the toxicity of three pharmaceutical individually and in a mixture for both Daphnia similis and zebrafish embryos. The results of individual acute toxicity showed that the microcrustacean was more sensitive to FXT (EC50 = 1.08 mg/L), PRP (EC50 = 5.92 mg/L) and DIC (EC50 = 25.0 mg/L), respectively, while for zebrafish embryos, it was only calculated LC50 of 30.5 mg/L for DIC, after 48h exposure. Antagonistic effects of binary mixtures of FLX + PRP (EC50 = 9.38%) and FXT + DIC (EC50 = 24.2%) were observed to D. similis. For Danio rerio embryos, binary mixture of FLX + DIC (LC50 = 82.1%) presented antagonistic effects, while no acute toxicity was observed for the of FXT + PRP mixture. Tertiary mixture of the three compounds showed an antagonist effect (EC50 = 5.57%) for the microcrustacean and additive effect for zebrafish embryos (LC50 = 87.5%). In conclusion, most of the binary mixture resulted in antagonistic effects, in which the response of acute toxicity depended on the organism and type of pharmaceutical mixture. Therefore, it is necessary further studies to assess the toxicity of different mixtures.

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  • IPEN-DOC 26791

    BEU, CASSIA M.L. ; LANDULFO, EDUARDO . Threshold wind speed and turbulence under LLJs events at Ipero - Brazil. In: COMERON, ADOLFO (Ed.); KASSIANOV, EVGUENI I. (Ed.); SCHAFER, KLAUS (Ed.); PICARD, RICHARD H. (Ed.); WEBER, KONRADIN (Ed.); SINGH, UPENDRA N. (Ed.) SPIE REMOTE SENSING, September 9-12, 2019, Strasbourg, France. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 1115212-1 - 1115212-10. (Proceedings of SPIE Vol. 11152, Remote Sensing of Clouds and the Atmosphere XXIV). DOI: 10.1117/12.2532281

    Abstract: The threshold wind speed is a useful criterion in determining whether strong turbulence is generated within the Stable Boundary Layer (SBL), the layer where all surface emissions remain con ned during the night. Con dence turbulence estimates are extremely important for atmospheric transport and dispersion simulations, although due to its complex dinamics many aspects of the SBL are neglected by numerical models that, in turn, are the inputs and boundary conditions for the transport and dispersion simulations. Turbulence is especially important during severe episodies like hazardous material accidental releases, for example. Turbulence intensity can a ect the dispersion speed, released material concentration, and its reach. For many decades, remote sensing has been an important tool in lling the gap of information and providing advances in the atmospheric sciences. The doppler lidar is increasingly being used for micrometeoroly and Planetary Boundary Layer (PBL) studies because of its autonomy and long range capability, in contrast with traditional techniques as radioprobes and captive balloons. After 1 year of continuous measurements with a doppler lidar, it was possible to determine the threshold wind speed for Ipero, Sao Paulo, Brazil. Besides threshold wind speed, it was observed that the SBL turbulence has a straight relationship with the Low-Level Jets (LLJs) that frequently occur over the region. The vertical turbulence distribution depends greatly on the LLJ characteristics, which in turn is highly variable during its life cycle. The strong turbulence regime is associated to the stronger LLJs, that presents a more de ned pattern. In contrast, weak LLJs (that generate weaker SBL turbulence) present more dispersive characteristics in respect to the entire dataset. These di erences are seen both for the LLJ height as for the turbulence vertical pro le. These results will contribute for the atmospheric modeling and dispersion simulations, as well for the environmental studies at Ipero.

    Palavras-Chave: wind; earth atmosphere; dispersions; jets; boundary layers

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  • IPEN-DOC 26790

    MACEDO, FERNANDA M. ; CORREA, THAIS ; ARAUJO, ELAINE ; ANDRADE, IZABEL ; ARLEQUES, ANTONIO G. ; MIRANDA, JULIANA T. de M. ; SILVA, JONATAN da ; GUARDANI, ROBERTO; VESELOVSKII, IGOR; LANDULFO, EDUARDO . Correlation between two different real time data acquisition systems: LIDAR Raman and Cavity Ringdown Laser Spectroscopy, for CH4 as a fugitive gas, in São Paulo Metropolitan Area. In: COMERON, ADOLFO (Ed.); KASSIANOV, EVGUENI I. (Ed.); SCHAFER, KLAUS (Ed.); PICARD, RICHARD H. (Ed.); WEBER, KONRADIN (Ed.); SINGH, UPENDRA N. (Ed.) SPIE REMOTE SENSING, September 9-12, 2019, Strasbourg, France. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 111521D-1 - 111521D-14. (Proceedings of SPIE Vol. 11152, Remote Sensing of Clouds and the Atmosphere XXIV). DOI: 10.1117/12.2533111

    Abstract: Fugitive emissions, defined as unintended or irregular leaks of gases and vapors, these are an important source of pollutants to the atmosphere, which is difficult to monitor and control. These sources are present in different sites, including megacities like São Paulo that are growing in size and economic activity. At the same time, there is a remarkable growth in concerns about the environmental issues associated with these activities. In a constantly changing world, with increasing concentrations of greenhouse gases (GHGs), among them methane (CH4) and volatile organic compounds (VOC), mitigation of atmospheric emission of these gases to contain global warming, make field campaigns in the metropolitan region of São Paulo very relevant. Optical remote sensing techniques as lidar can attend the need for real time and trustable information on fugitive emissions. The Cavity Ringdown Laser Spectroscopy (CRDS) technique was adopted because it is widely used in the detection of gas samples that absorb light at specific wavelengths and also for their ability to detect mole fractions up to the parts per trillion level. The Raman lidar system used includes a commercial laser pulsed Nd:YAG Quantel S.A., model CFR 200, with wavelengths of 355 nm, 353 nm and 396 nm, 120 mJ pulse power, with laser repetition rate of 20 Hz and pulse width of 20 s, with a spatial resolution of 7,5 m. The system includes an ethernet interface, used together with LabView software to control the measurement and readout of the acquired data. The mixing ratio of CH4 can be observed within the planetary boundary layer. The measured methane profiles correlate with the acquisitions made with the CRDS, however, an additional contribution of control data in which the Raman lines detect with high sensitivity.

    Palavras-Chave: methane; optical radar; biomass; biofuels; raman effect; rotational states

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  • IPEN-DOC 26789

    GEORGESCU, GABRIEL; NUNES, MARCOS E.C.; OLIVEIRA, PATRICIA da S.P. de ; WIELENBERG, ANDREAS; NIEMELA, ILKKA; DUPUY, PATRICIA. RISKAUDIT and CNEN cooperation on probabilistic safety analysis. In: INTERNATIONAL TOPICAL MEETING ON PROBABILISTIC SAFETY ASSESSMENT AND ANALYSIS, 16th, April 28 - May 3, 2019, Charleston, South Carolina, USA. Proceedings... Illinois, USA: American Nuclear Society, 2019. p. 781-784.

    Abstract: The Brazilian project BR3.01/12 financed by European Union through the “Instrument for Nuclear Safety Cooperation” (INSC) programme and accomplished by RISKAUDIT organization (IRSN, GRS and STUK) constituted a support for enhancing and strengthening Brazilian Safety Authority (CNEN) expertise in regulatory and licensing activities, including probabilistic safety analysis (PSA), deterministic analysis and ageing management. The objectives of the project PSA task were to provide support to CNEN on the enhancement of its regulatory capability related to PSA development, review and applications and to provide support to CNEN on the review of the documents related to parts of Level 1 and 2 PSAs submitted by the utility, Eletronuclear (ETN), for the Brazilian NPPs of the CNAAA, which is a nuclear station located in Angra dos Reis, Rio de Janeiro. The activities focused on the updating and enhancement of Brazilian regulatory requirements for development and use of PSA, development of the Brazilian guide on regulatory review of PSA, support CNEN on the preliminary review of the PSAs for Angra 2 NPP, support CNEN on the management of Level 1 PSA computer codes and training CNEN staff on PSA methods, PSA review and PSA applications. The project, which started in May 2015, successfully ended in May 2018.

    Palavras-Chave: international cooperation; safety reports; radiation protection; safety analysis

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  • IPEN-DOC 26788

    SILVA, N.F. ; SILVA, T.F.; CASTRO, M.C. ; LUZ, H.N. da; CALDAS, LINDA V.E. . Garfield++ simulation of a TH-GEM based detector for standard mammography beam dosimetry. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: The TH-GEM based detector is a robust, simple to manufacture, high-gain gaseous electron multiplier. Its operation is based on a standard printed circuit board (PCB) coated on both sides by metallic material, perforated in a millimeter pattern, and immersed in gas. In order to study the feasibility of using TH-GEM type detectors in dosimetric applications for standard mammography beams, a prototype with adequate dimensions and materials was produced. The present work encompasses the calculations of electric fields by the Gmsh and Elmer software packages and the avalanche simulation using Garfield++ library of a TH-GEM detector filled with Ar/CO2 (70:30) mixture at atmospheric pressure.

    Palavras-Chave: charge transport; computer calculations; computer codes; computerized simulation; dosimetry; mammary glands; radiation detectors; standards

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  • IPEN-DOC 26787

    POLO, IVON O. ; CALDAS, LINDA V.E. . Fading estimation of SOL-GEL α-Al2O3 detectors. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: The OSL and the TL techniques are used in several fields of radiation dosimetry. The dosimeters are affected by a signal loss in the time between the irradiation and readout (fading). This undesirable characteristic can cause an underestimation of the irradiation dose. The fading estimation of SOL-GEL α-Al2O3 with several different concentrations of impurities is reported. The thermal fading and the light-induced fading of the SOL-GEL α-Al2O3 detectors were estimated. Furthermore, the exponential equations used to interpolate the experimental results were presented.

    Palavras-Chave: aluminium nitrates; attenuation; dosemeters; dosimetry; energy losses; radiation quality; thermoluminescent dosimetry

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  • IPEN-DOC 26786

    SANTOS, WILLIAM S. ; SANTOS, CARLA J.; SILVA, ALINE F. da; SOUZA, SAMARA P.; NEVES, LUCIO P.; BELINATO, WALMIR; CALDAS, LINDA V.E. ; PERINI, ANA P.. Dose evaluation in breast brachytherapy using different 125I seeds: a Monte Carlo approach. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: A very common type of cancer among women is the breast cancer. The treatment choice depends, among several factors, on the clinical stage of the disease and the age. One way to treat breast cancer is the permanent breast seed implant, with Iodine-125 (125I). Since they present some advantages: possibility to treat solid tumors, near the tumor site, induction of little trauma and strong lethality to cancer cells. In Brazil, a new 125I seed was developed at the Instituto de Pesquisas Energéticas e Nucleares to be applied in brachytherapy. Given the large number of women diagnosed with breast cancer, in this work, the dose determination in organs and tissues was undertaken, considering this new seed and a commercial, Amersham 6711-Oncoseed®, employing the Monte Carlo method. Moreover, for a better understanding of the radiation doses delivered to different patients, the breast volumes were modified. For this purpose, the MCNPX Monte Carlo code was utilized coupled with female virtual anthropomorphic phantoms. The results pointed out the highest dose values for the breast and skin. Furthermore, the dose results for both types of seeds were very similar.

    Palavras-Chave: mammary glands; neoplasms; brachytherapy; monte carlo method; radiation doses

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  • IPEN-DOC 26785

    SANTOS, WILLIAM S. ; NEVES, LUCIO P.; PERINI, ANA P.; SANTOS, CARLA J.; BELINATO, WALMIR; SILVA, ROGERIO M.V.; SOARES, MARIA R.; VALERIANO, CAIO C.; CALDAS, LINDA V.E. . Computational modelling of cervix uterus radiation procedure using a virtual anthropomorphic phantom and the MCNPX code. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: There is a serious, and growing, concern about the increased risk of the emergence of a secondary cancer, radio-induced, associated with radiotherapy treatments. To assess the radiation doses to organs outside the target volume, in this work, several computational exposure scenarios were modelled, based on Monte Carlo simulation (MCNPX code). A Varian 2100c accelerator, and a female virtual anthropomorphic phantom were used, in a simulated treatment of cervical cancer. The determination of the dispersed dose would be important for assessing the risk in different organs or tissues. Four treatment fields were applied, varying the gantry angle. It was possible to observe that the conversion factors for equivalent dose were higher for the AP projection. For the RLAT and LLAT projections, the results were similar, fact that may be attributed to the symmetrical distributions of the organs in relation to the radiation source. The results presented in this work showed that the computational exposure scenario provides a versatile and accurate tool to estimate in a ready way the absorbed doses during a cervical treatment.

    Palavras-Chave: absorbed radiation doses; animal tissues; computerized simulation; dosimetry; monte carlo method; organs; phantoms; radiotherapy; uterus

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  • IPEN-DOC 26784

    LITVAC, DANIEL ; CALDAS, LINDA V.E. . Calibration of a clinical beta therapy applicator using the thermoluminescence samples: preliminary results. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: In some parts of Brazil, 90Sr/90Y clinical applicators are still used for dermatological and ophthalmic treatments, even with the higher efficiency of linear accelerators because they are of lower cost and easier use. Calibration and periodic recalibration of these applicators to verify the absorbed dose rate is essential to ensure accuracy in clinical treatments. In this work the thermoluminescent response of BeO and μLiF pellets was evaluated, determining the reproducibility, linearity of response and their dose-response curves. This standard, for this type of calibration, recommends the use of small detectors such as μLiF. Therefore, the utility of μLiF and BeO in the calibration of clinical applicators was compared.

    Palavras-Chave: beryllium oxides; lithium fluorides; beta particles; calibration; comparative evaluations; dosimetry; radiation sources; therapy; thermoluminescence

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  • IPEN-DOC 26783

    SANTOS, ADIMIR dos ; YAMAGUCHI, MITSUO ; FANARO, LEDA C.C.B. ; SANTOS, DIOGO F. dos ; SOUZA, GREGORIO S. de ; JUNQUEIRA, FERNANDO de C. ; SILVA, GRACIETE S. de A. e ; BELCHIOR JUNIOR, ANTONIO ; PRADO, ADELK de C. ; JOAO, THIAGO G.; ROSSI, PEDRO C.R.. New plate-type core of the IPEN/MB-01 research reactor facility for validation of RMB project. In: INTERNATIONAL CONFERENCE ON RESEARCH REACTORS: ADDRESSING CHALLENGES AND OPPORTUNITIES TO ENSURE EFFECTIVENESS AND SUSTAINABILITY, November 25-29, 2019, Buenos Aires, Argentina. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2020.

    Abstract: The IPEN/MB-01 research reactor had its first criticality in November 1988 and, ever since, has been of major importance in Brazilian reactor physics researches, achieving international level for experiments comparison and validation (benchmarks). In this facility it is possible to build many different core configurations (i.e., rectangular, square and cylindrical), once versatility and flexibility were both taken into account on its initial project. The core is a fissile material assembly, inserted in a water tank, where the chain reaction is self-maintained and controlled at low power levels, so that, in normal operation, the feedback effects of temperatures are negligible. The core is intended for neutrons simulation of light water moderated reactors allowing the experimental verification of the calculation methods, reactor cell and mesh structures, control rods effectiveness, isothermal reactivity coefficients and core dynamics due to reactivity insertions. The first standard IPEN/MB-01 core had UO2 rod-type fuel, 4.3 % enriched in U-235 and using B4C and Ag-In-Cd rods for safety and control of the reactor. The facility is located at IPEN/CNEN-SP (Nuclear and Energy Research Institute), in Sao Paulo - Brazil. Within the scope of the new research reactor project, the Brazilian Multipurpose Reactor (RMB), it was designed a new critical configuration for the IPEN/MB-01. After thirty years of work, the rod-type fuels were replaced by plate-type fuels, in order to validate the RMB calculation methodologies, as well as the nuclear data libraries used. The RMB is an open pool-type reactor with maximum power of 30 MW, being the core a 5x5 configuration, consisting of 23 fuel elements, made of U3Si2-Al, having a medium density of 3.7 gU/cm3 and 19.75% enriched in U-235, and two positions available in the core for materials irradiation devices. The production of radioisotopes, silicon doping, neutron activation analysis, nuclear fuels and structural materials testing and the development of scientific and technological research using neutron beams are the main targets of the RMB enterprise. The new IPEN/MB-01 core has a 4×5 configuration, having 19 fuel elements, consisting of U3Si2-Al, 2.8 gU/cm³ and 19.75% enriched in U-235, plus one aluminum block. The IPEN/MB-01 new plate-type fuel assembly uses Cadmium wires as burnable poison, as the one used in RMB core for controlling the core power density and excess of reactivity during its operation. The core is also reflected by 4 boxes of heavy water (D2O), inserted in a moderator tank of light water. The maximum nominal power is 100 W and, for a safe operation, the critical assembly has both safety and auxiliaries’ systems. This paper presents a description of the new core and the principal neutronic parameters. The new core of the IPEN/MB-01 will be certainly a world class benchmark core for the core physics calculation of research reactors.

    Palavras-Chave: burnable poisons; control rod worths; cylindrical configuration; fuel elements; heavy water; neutron activation analysis; neutron beams; reactor cores; rmb reactor; uranium 235

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  • IPEN-DOC 26782

    FUNGARO, D.A. ; ROVANI, S. . Extração de sílica a partir das cinzas de resíduo da cana-de-açúcar em diferentes condições de extração alcalina. In: BALDOVI, ALDREW A. (Ed.); CONCEIÇÃO, ANA C.S. (Ed.); ANTENOR, ANANDA de O.G. (Ed.); CHYOSHI, BRUNA (Ed.); COSTA, DANILO O. da (Ed.); ANDRADE, HEDLLA M. (Ed.); FARIA, JULIA K. (Ed.); KOHATSU, MARCIO Y. (Ed.); MENDES, MARIANA E. (Ed.); COELHO, LUCIA, H.G. (Coord.); TAMBOSI, LEANDRO R. (Coord.) SIMPÓSIO DE CIÊNCIA E TECNOLOGIA AMBIENTAL, 1st, 2-3 de outubro, 2019, Santo André, SP. Anais... Santo André, SP: Universidade Federal do ABC, 2019. p. 239-244.

    Abstract: Uma amostra de cinzas geradas durante a queima de resíduos de cana-de-açúcar foi triturada com NaOH sólido variando-se a relação cinzas: NaOH (m/m). As misturas foram submetidas ao processo de fusão a 450 oC por 1 h. Após o resfriamento, a sílica da massa fundida foi lixiviada para a fase líquida na forma de silicato de sódio. Seguindo a separação do sólido e do líquido, partículas de sílica foram precipitadas pela adição de ácido sulfúrico até pH 7 à solução de silicato de sódio. O rendimento das amostras mostrou-se constante e uma pureza de 89% foi alcançada. As amostras de cinzas e de sílica produzidas foram caracterizadas por difração de raios-X, fluorescência de raios-X e análise elementar.

    Palavras-Chave: sugar cane; biomass; ashes; silica

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  • IPEN-DOC 26781

    URBANI, G.L.; FRANCO, M.K.K.D. ; YOKAICHIYA, F. ; VICENTE, R. . Aplicação da química de radiação à questões tecnológicas do cimento relacionadas ao desenvolvimento de repositórios de rejeitos radioativos do modelo borehole. In: BALDOVI, ALDREW A. (Ed.); CONCEIÇÃO, ANA C.S. (Ed.); ANTENOR, ANANDA de O.G. (Ed.); CHYOSHI, BRUNA (Ed.); COSTA, DANILO O. da (Ed.); ANDRADE, HEDLLA M. (Ed.); FARIA, JULIA K. (Ed.); KOHATSU, MARCIO Y. (Ed.); MENDES, MARIANA E. (Ed.); COELHO, LUCIA, H.G. (Coord.); TAMBOSI, LEANDRO R. (Coord.) SIMPÓSIO DE CIÊNCIA E TECNOLOGIA AMBIENTAL, 1st, 2-3 de outubro, 2019, Santo André, SP. Anais... Santo André, SP: Universidade Federal do ABC, 2019. p. 226-231.

    Abstract: Resíduos radioativos são usualmente descartados em repositórios do tipo borehole ou de superfície. Por questões de segurança, devem ser depositados em tambores e cobertos por cimento na sua destinação final. A radiação gama proveniente dos resíduos radioativos interage com a água livre da pasta de cimento e causa o fenômeno da radiólise. Essa interação que decompõe a água da pasta de cimento é estudada pela academia científica e ainda não é um consenso se a mesma afeta a resistência do concreto ou não. Para um melhor entendimento dessa questão, nesse estudo um modelo teórico simples é sugerido para quantificar a porcentagem da água que sofre radiólise e se essa perda é suficiente para afetar a resistência da barreira de cimento. O resultado indica que a quantidade de água perdida neste processo não é suficiente para diminuir a resistência do concreto. O modelo proposto foi aplicado para verificar os resultados experimentais, utilizando as condições iniciais expostas na literatura existente, com o propósito comparação e discussão sobre o fenômeno da radiólise.

    Palavras-Chave: radioactive waste storage; storage facilities; portland cement; portland cement; boreholes; radiolysis

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  • IPEN-DOC 26780

    ZUFFI, ARMANDO V.F. ; ALMEIDA, ANDREIA A. ; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Development of glass nozzles for below threshold harmonics and high harmonic generation. In: FRONTIERS IN OPTICS; LASER SCIENCE CONFERENCE AND EXHIBITION, 15-19 September, 2019, Washington, DC, USA. Resumo expandido... Washington, DC, USA: OSA, 2019.

    Abstract: This work reports development of glass nozzles by ultrashort laser pulses machining for studies of harmonic generation in gases. Those nozzles generated odd harmonics (3rd up to 25th) in UV and VUV regions.

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  • IPEN-DOC 26779

    TOMINAGA, F.K. ; SILVA, T.T. ; JESUS, J.M.S. de; BOIANI, N.F. ; TEIXEIRA, A.C.S.C.; BORRELY, S.I. . Effect of electron beam irradiation on mineralization and toxicity of aspirin. In: IBEROAMERICAN CONFERENCE ON ADVANCED OXIDATION TECHNOLOGIES, 4th; ISE SATELLITE STUDENT REGIONAL SYMPOSIUM ON ELECTROCHEMISTRY, 7th, November 18-22, 2019, Natal, RN. Resumo expandido... 2019. p. 1-3.

    Abstract: Electron Beam Irradiation (EBI) is an important technology for degradation, mineralization and detoxification of pollutants. In this work, total organic carbon (TOC) and toxicity was evaluated for aspirin after Electron Beam Irradiation at doses of 1.0, 2.5 and 5.0 kGy. Low mineralization was achieved at all applied doses. Toxicity increase and hydrogen peroxide formation was observed with the increase of absorbed dose. EBI can be an interesting alternative process applied as a pre-treatment for alternatives AOPs.

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  • IPEN-DOC 26778

    ROSSI, WAGNER de ; HERRERA, CRISTHIANO da C.; GOMES, ANTONIO A. ; BALDOCHI, SONIA L. . Femtosecond laser micromachining of microfluidic components in BK7 optical glass. In: EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES, September 1-5, 2019, Stockholm, Sweden. Abstract... Boutersem, Belgium: Federation of European Materials Societies, 2019. p. 898-898.

    Abstract: Introduction/Purpose The objective of this work was the development of micromachining with femtosecond laser in BK7 optical glass for the production of components of microfluidic devices. The aim was to produce microchannels, microvalves, micropumps, mixers and a localized heater, which can be arranged in any way to produce microfluidic devices on demand. Methods The structures were machined on the surface of BK7 glass plates, with the use of ultrashort laser pulses of a Ti:sapphire system on a high precision displacement stage and numerical control program. The first step was to obtain a set of process parameters suitable for efficient and accurate machining that would result in a smooth surface with no collateral damage to the neighboring region. Results Microvalves were machined with these optimized parameters, and when powered by pneumatic drive and managed by a dedicated software presented a flow control of less than 1 nl/s. These microvalves were used together to produce micrpumps to control flows in regions where external pressure can not be achieved. Mixers are also being developed for single phase systems and for biphasic systems. A machine vision system is being used to characterize both systems. Color analysis for single phase mixers and bubble analysis for biphasic ones. An innovative localized heating system was developed for temperature control in microreactors. For this, a tiny metal blade was textured with fs laser where light absorptive nanostructures were obtained. The slide was introduced into a microreator that had its temperature controlled through the focusing of an external source of light on its surface. With this, it was possible to control temperature above 100°C inside the microreator. Conclusions With the developed components, some microfluidic systems were built. In particular, a system for synthesis of NaYF4 nanocrystals and for ELISA assays will be presented.

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  • IPEN-DOC 26777

    FREIRE, L.O. ; ANDRADE, D.A. de . The four functions of elementary pipe design from constructal law. In: CONSTRUCTAL LAW AND SECOND LAW CONFERENCE, March 11-13, 2019, Porto Alegre, RS. Resumo expandido... 2019. p. 1-4.

    Abstract: Constructal law explains the sense of evolution (morphing to improve flows) of beings, but paradoxes do exist as not all vegetables have a tree form. Also, not all animals are optimized for displacement. This work aims at identification of the design functions or objectives that guide evolution under the overall statement of constructal law. This work adopted the system engineering technique of segregation between functions (abstract objectives) and solutions (physical entities). Further, this work introduced the assumptions of flow under external threats and pipes subject to leakages. Results showed that there are always elements doing four functions in pipe element: to reduce flow entropy, to protect flow channel, to retain flow content and to increase flow drive. Although the four functions are always present, natural systems typically privileges some functions over others, depending on environmental pressures. As a solution to improve flows, animal brains also fit in the model of four functions. Human mind seems to have groups of instincts associated to each of the four pipe design functions (fear, attachment, curiosity and greed). Finally, the four functions model unified physics and animal psychology.

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  • IPEN-DOC 26776

    GATTI, LUCIANA; MILLER, JOHN B.; BASSO, LUANA S.; DOMINGUES, LUCAS G. ; CASSOL, HENRIQUE L.G.; MARANI, LUCIANO; CORREIA, CAIO S. de C. ; IPIA, ALBER; ARAI, EGIDIO; TEJADA, GRACIELA; ARAGÃO, LUIZ E.O.C.; ANDERSON, LIANA O.; VON RANDOW, CELSO; GLOOR, MANUEL; PETERS, WOUTER; NEVES, RAIANE A.L.; CRISPIM, STEPHANE P.. Amazon carbon balance and its sensitivity to climate and human-driven changes. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: The Amazon accounts for 50% of Earth’s tropical rainforests hosting the largest live carbon pools in vegetation and soils (~200 PgC). The net carbon exchange between tropical land and the atmosphere is critically important, because the stability of carbon in forests and soils can be disrupted on short time-scales. The main processes releasing C to the atmosphere are deforestation, fires and changes in growing conditions due to increased temperatures and droughts. Such changes may thus cause feedbacks on global climate. In the last 40 years, the Amazon mean temperature has increased by 1.1ºC. Annual mean precipitation has also decreased by 51 mm during this same 40 year period. The precipitation reduction occurred mainly in the dry season, and the dry season has lengthened, exacerbating vegetation water stress with consequences for carbon balance. To better understand its C budget, starting in 2010 we established a regionally representative greenhouse gas monitoring program across Amazonia. The program aims to quantify gas concentrations (CO2, CH4, N2O, CO, and SF6) based on extensive collection of air from light aircraft vertical profiles. The atmosphere is profiled from the ground up to 4.5 km height at four sites along the main air-stream over the Amazon Basin on a twice-monthly basis. Here we will report what these new data tell us about the carbon balance and its controls from 2010-2017. During this period we performed 513 vertical profiles over four strategic regions that represent fluxes over much of Amazonia. The observed variability of carbon fluxes during these 8 years is correlated with climate-related (temperature, precipitation, soil water storage from GRACE satellite) and anthropogenic (fire counts) variables. The correlations were performed inside the upwind area for each profiling site. During our study period, the Amazon was a consistent source of 0.4 ± 0.2 PgC/year on average, extrapolating to the entire Amazon Basin area of 7.2 million km2. Fire emission is the main source of carbon to the atmosphere, which is not compensated by the C removal from old-growth Amazon forest. Moreover, the drought years of 2010, 2015 and 2016 are playing an outsized role in the eight-year mean. Removing those years from the mean, the net source is reduced from 0.4 ± 0.2 PgC/year to 0.2 ± 0.2 PgC/year.

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  • IPEN-DOC 26775

    MORAIS, FERNANDO; LANDULFO, EDUARDO ; ARTAXO, PAULO; FRANCO, MARCO A.; SCHAFER, JOEL; HOLBEN, BRENT. Long term characterization of brown carbon in Amazonia using AERONET and in situ measurements. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Optical properties of aerosols in Amazonia have been measured over the last 19 years at several AERONET sites using CIMEL sunphotometers. Ground based measurements of aerosol absorption properties using AE33 Aethalometers were performed in several sites in Amazonia. Measurements were done in Central Amazonia (ATTO tower), as well as in Rio Branco, Cuiabá, Ji-Paraná, and Alta Floresta. The results show an important contribution to absorption by the brown carbon (BrC) component together with black carbon (BC). This behavior can be strongly observed at the wavelengths of 440nm and 470nm, for AERONET and AE33 measurements, respectively. Results from AERONET showed that, in sites dominated by biomass burning such as Alta Floresta, Rio Branco and Ji-Paraná, the BrC was about 20% of BC. In special, for the dry season of 2018 at Rio Branco, the BrC was about 9% of BC, with values of 3.28±3.45 µg m-3 and 0.34±0.58 µg m-3 for BC and BrC, respectively. The measured high variability in the ratio BrC/BC was due to different aging of biomass burning plumes that reached the site, some with high BC values of up to 24 µg m-3. On the other hand, in situ measurements at the ATTO Tower showed that the BrC component can account for 30% of total absorption. For the wet season of 2019, it was observed that BrC accounts for 28 % of BC, with mean values of BC and BrC of 0.23±0.16 µg m-3 and 0.054±0.075 µg m-3, respectively. The high variability in this case was due to plumes of African biomass burning that reached the site in different periods. For central Amazonia, ground based in situ measurements and AERONET agree quite well in the in situ BrC determination, showing a well-mixed atmosphere due to strong convection.

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  • IPEN-DOC 26774

    JEONG, DAUN; SECO, ROGER; EMMONS, LOUISA K.; SCHWANTES, REBECCA; LIU, YINGJUN; MCKINNEY, KARENA A.; MARTIN, SCOT T.; KEUTSCH, FRANK N.; GU, DASA; GUENTHER, ALEX B.; VEGA, OSCAR ; TOTA, JULIO; SOUZA, RODRIGO A.F. de; SPRINGSTON, STEPHEN R.; WATSON, THOMAS B.; KIM, SAEWUNG. Reconciling measured OH through box model simulations during GoAmazon2014/5. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Hydroxyl radicals (OH) are important oxidants in the troposphere, controlling the lifetime of trace gases including methane, which is a greenhouse gas. The primary production of OH is from the photolysis of O3. OH levels can be further sustained through HOx-NOx recycling reactions. Volatile organic compounds (VOC) react with OH to produce organic peroxyl radicals (RO2), which can oxidize NO to NO2, leading to O3 production and subsequent re-generation of OH. However, in low NOx and high VOC environments, OH levels can be limited due to the production of stable peroxides from reactions between peroxy radicals. Therefore, conventional chemistry predict constrained OH levels in remote forest regions. Observations of OH carried out in forests, however, have consistently reported up to 10-fold higher than expected OH levels. In this study, we report OH observations by chemical ionization mass spectrometry (CIMS) conducted in a rainforest environment during the GoAmazon2014/5 campaign. The measurements used in this study, were during the wet season (IOP1), at the T3 site, which was ~ 60 km west of Manaus, Brazil. OH observations are compared to observation constrained box model simulations embedded with a near-explicit chemistry like MCM 3.3.1 (Master Chemical Mechanisms) and condensed mechanisms like RCIM (Reduced Caltech Isoprene Mechanism), CB05 (Carbon Bond Mechanism), CB6r2 (Carbon Bond 6 Mechanism), RACM2 (Regional Atmospheric Chemistry Mechanism), and MOZART_T1 (Model for Ozone and Related Chemical Tracers) that are used in global models.

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  • IPEN-DOC 26773

    CORREA, E.L. ; PEREIRA, L.F. ; FERREIRA, W.L. ; BOSCH-SANTOS, B. ; SCALISE, L. ; GONÇALVES, V. ; SANTOS, R. dos ; SCHELL, J.; CARBONARI, A.W. . Study of the local magnetics and electrics properties at Gd2Ti2O7 by PAC spectroscopy and ab initio calculations. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 760-760.

    Abstract: Gd2Ti2O7 exhibits a complex magnetic behavior with a geometrically frustrated antiferromagnetic ordering below TN = 1.1 K and a second magnetic transition at 0.7 K. In the work here reported, perturbed angular correlation (PAC) technique was used in order to measure electric quadrupole hyperfine interactions at 111mCd probe nuclei on Ti sites. These experimental results along with those for magnetic hyperfine interactions at 155Gd previously reported from Mossbauer Effect spectroscopy were interpreted with electronic structure first-principles calculation. Single and doped-Cd cell simulations have been performed with potential linearized augmented plane waves methods and generalized gradient approximation from Perdew-Burke-Ernzerhorf embodied within the WIEN2k all-electron code. PAC measurements have exhibited 111mCd probes occupying two fraction sites characterized by well-defined quadrupole frequencies (as shown in the spin-rotation spectra in the figure) with almost the same values for the corresponding electric field gradient (efg), however, with slightly difference in the asymmetry parameters. Theoretical efg’s obtained for Cadmium atoms located at Gd or Ti sites of the pyrochlore structure indicate that both experimental hyperfine parameters corresponding to Cd at Titanium site.

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  • IPEN-DOC 26772

    BOSCH-SANTOS, B. ; NASCIMENTO, N. ; SAIKI, M. ; CORREA, E.L. ; SALES, T.S. ; PEREIRA, L.F. ; CABRERA-PASCA, G.A.; CARBONARI, A.W. . Magnetic field at Ce impurities in La sites of LaBaMn2O6 double perovskites. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 759-760.

    Abstract: Magnetic behavior in LaBaMn2O6 double perovskite compounds has been investigated with various techniques, due to the rich variety of electromagnetic properties, such as a colossal magnetoresistance, charge and orbital ordering, and metal-insulator transition. In this paper, we have used a nuclear and short-range technique, the Perturbed Angular Correlation (PAC) spectroscopy, to investigate the magnetic hyperfine field at the 140Ce nucleus of Ce impurities occupying La sites. The radioactive 140La nuclei with a half-life of 40.8 h were produced by direct activation of natural La present in the samples through the irradiation with neutrons in the IEA-R1 nuclear research reactor of IPEN. The PAC measurements were carried out with a six BaF2 detector spectrometer at several temperatures between 10 K and 400 K. This double perovskite samples were synthesized by sol-gel route. The crystal structure was determined by X-ray diffraction and the analyses showed that this method produced perovskite oxides with cubic structure in Pm-3m space group. This phase occurs due to an oxygen deficiency. The local properties investigated by PAC spectroscopy revealed a ferromagnetic transition temperature above 300 K and an anomalous behavior of the temperature dependence of magnetic hyperfine field at La sites, which can be ascribed to the contribution of 4f band of Ce to Bhf at low temperatures due to the increase in its localized character.

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  • IPEN-DOC 26771

    PEREIRA, L.F. ; CARBONARI, A.W. . Local magnetic interactions in Cadmium-doped Cobalt allotropic phases by first principles calculation. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 600-600.

    Abstract: Cobalt is one of the most attractive ferromagnetic material at room temperature. While Co is used in industrial processes of catalysis, in fundamental science, the connection between the different crystal structure with magnetic properties of Co has attained the attention. Co can crystallize in four different structures: hexagonal closed-packed (hcp, alpha), face-centered cubic (fcc, beta), primitive cubic (epsilon), and body-centered cubic (bcc). The hcp and fcc phases are stable in bulk and nanostructured samples and the difference in their formation energy is small so that, even under small variations of temperature and/or pressure conditions, hcp and fcc can interexchange easily. Often, the literature reports the co-existence of both structures. In last years, new routes of the synthesis and improvement in previous methods have allowed the production of nanostructured Cobalt samples with Epsilon and bcc crystalline phases, which under usual conditions are metastable. The magnetic properties vary with the structure differences in their electronic structure, e.g. the hcp phase has higher coercivity, whereas the fcc is a soft magnet In the work here reported, first-principles calculations were performed in the four Co structures in order to investigate one sensitive and quite local parameter: the magnetic hyperfine field (mhf). We have used Augmented Planes Waves plus local orbitals (APW+lo) all-electron method based on the density functional theory and implemented in the WIEN2k code to simulate supercells of Co doped with Cd. The resulting mhf at Cd ions is compared with values from perturbed angular correlation spectroscopy measurements using 111Cd as probe nuclei found in the literature for hcp, fcc, and bcc phases. Up to date, experimental results for mhf at 111Cd for epsilon structure are not available. Calculated mhf and magnetic moments agree well with reported experimental values - tab. 1. From the calculated density of states for each structure, it is possible to investigate the differences in the magnetic exchange interaction at an atomic view

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  • IPEN-DOC 26770

    GOMES, DANIEL de S. . Study of thoria-urania fuel during accidents. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 25th, October 20-25, 2019, Uberlândia, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2019.

    Abstract: In this investigation, nuclear fuel based on mixed ceramic oxides, using (Th–U)O2 as nuclear fuel and zirconium-based alloy as cladding, was simulated. This strategic configuration can achieve improved safety margins because of an enhanced set of thermal and mechanical properties. The Experimental Breeder Reactor built in the 1950s in Idaho introduced the concept that a reactor can generate more fissile material than it consumes. The thorium fuels have a lower cost and should decrease weapon-grade plutonium compared with conventional fuel, UO2. The nuclear characteristic of thorium-232 or U-238 can make a converter into U-233 or Pu-239. However, using thoria fuels can avoid weapon proliferation by reducing plutonium, and it also should reduce radionuclides such as (Np, Am, Cm). This study uses an optimized composition of Th-75% wt and U-25% wt with an enrichment of 19.5%. We studied the behavior using the fuel licensing codes FRAPCON and FRAPTRAN, including many adaptations for the mixed composition choice. The results prove that thoria–urania fuel has a higher performance than pure uranium dioxide fuel during accidents.

    Palavras-Chave: thorium; uranium; loss of coolant; accidents; nuclear fuels

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  • IPEN-DOC 26769

    COSTADELLE, EWERTON L. ; FIGUEIREDO, NEY G.F. ; BARRETO, ROGERIO L. ; ALMEIDA, GISELE F.C. ; COUTO, ANTONIO A. . Creep-testing machine retrofit for Ti-6Al-4V alloy study. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 25th, October 20-25, 2019, Uberlândia, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2019.

    Abstract: The Nuclear and Energy Research Institute received two Creep-Testing Machine frame donated from Technological Institute of Aeronautics in nonfunctional mode. These apparatuses has arrived with structure, lever arm and tube furnace. However, they came with no strain gage and no temperature controller. In order to back the machinery to active mode, this work developed a Creep-Testing Machine modernization suite. In fact, this study developed a new PID controller hardware, based in an Arduino open platform. In addition, it used a LVDT developed in Brazil, by Technological Research Institute, to capturing the specimen strain. After the modernization suite implementation, it evaluated the creep strain-rate of the Ti6Al4V alloy at 873 K in 319 MPa. Moreover, compared the results of the same lot material tested in another two ones apparatuses. This open technology was able to maintain the specimen temperature in the set point, getting and saving the test results in a text file and it got results close to the most modern equipment.

    Palavras-Chave: retrofitting; titanium; creep

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  • IPEN-DOC 26544

    AMARAL, MARCELLO M.; PRETTO, LUCAS de ; RAELE, MARCUS P. . Optical evaluation of polymer deposition for 3D printing. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2019.

    Abstract: 3D printing is a technology that is revolutionizing the productive sector [1]. It allows the production of free- form components and systems. It may ¯nd application from biomedical to aerospace engineering, as well as in the production of unique and speci¯c components needed in basic science laboratories. One of the most common approaches for 3D printing is the fused deposition modeling were a plastic ¯lament is fused and the component shape is modeled by layers deposition [2]. The success in the manufacture of the component is related to the addition between successive deposited layers. Increasing the temperature of the ¯lament to ensure perfect adhesion may compromise the desired shape and function characteristics for the component. Scanning Electronic Microscopy (SEM) is the gold standard technique to ensure the ideal condition for the 3D printing and evaluate the bonding between successive layers [2]. However, in this context, SEM is a destructive technique and do not allow real time application. Low Coherence Interferometry (LCI) is an optical technique capable to performing non-destructive tomography evaluation of scatter medium [3]. Using a Michelson interferometer to measure the backscattered light intensity as a function of depth position associated to a lateral scanning it is possible to obtain a cross-section image of the sample [3]. It is non-invasive, relatively inexpensive technique and could allow real time application during manufacturing. The aim of this work was to investigate the use of low coherence interferometry to evaluate the adhesion of successive layers on 3D printed plastic material. A set of samples were manufactured using a 3D printing (Cliever CL1, Brazil), with layer thickness from 100¡250¹m using PLA ¯lament. The sample were evaluated using a SEM and a commercial LCI (OCP930SR - Thorlabs Inc.) and the images were compared. It was possible to observe a correlation on the observed fused ¯laments between the images acquired by SEM and LCI proving that it is possible to use the optical technique as a alternative for 3D printing quality evaluation.

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  • IPEN-DOC 26552

    BENTO, RODRIGO T. ; SILVA FILHO, JORGE C. ; CORREA, OLANDIR V. ; TAKIISHI, HIDETOSHI ; PILLIS, MARINA F. . Synthesis and characterization of reduced graphene oxide-modified anatase TiO2 photocatalysts grown by MOCVD. In: E-MRS SPRING MEETING; IUMRS-ICAM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, May 27-31, 2019, Nice, France. Abstract... 2019.

    Abstract: Inadequate disposal of industrial waste, such as textile dyes and emerging contaminants, have been caused several environmental hazards. Titanium dioxide (TiO2) photocatalysis is an efficient green method for water treatment by solar energy. However, due to its large band gap of 3.2 eV, TiO2 absorbs mostly the UV radiation, which represents only 5-8% of the sunlight spectrum. Recent studies indicate that the surface modification of TiO2 results in an increase in photocatalytic efficiency. In this way, the present paper aims to evaluate the effects of TiO2 surface modification by reduced graphene oxide (rGO). The 470 nm thick anatase-TiO2 films were grown by MOCVD process in a conventional horizontal homemade reactor, on borosilicate substrates at 400 °C. The TiO2 films obtained were dipped into an alkoxide solution including 0.5, 1.5 and 3.0 mg of rGO and 30 mL isopropanol, ultrasonic-treated at room temperature for 40 min, and then dried in an oven at 100 and 150 °C for 24 h. The photocatalytic activity of rGO-TiO2 composites were evaluated by the methylene blue degradation under UV and visible light. The chemical, structural and morphological properties were also characterized. It was observed the presence of rGO agglomerates completely adhered to TiO2 surface. The diffraction peaks identified correspond to anatase phase. Peaks of graphene were also found. The results suggest that the rGO-TiO2 composites have a great potential to be used in water treatment under sunlight.

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  • IPEN-DOC 26538

    OLIVEIRA, EDUARDO C. de ; BENTO, RODRIGO T. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. . Performance of nitrogen-doped TiO2 films grown by MOCVD for water treatment under visible light. In: E-MRS SPRING MEETING; IUMRS-ICAM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, May 27-31, 2019, Nice, France. Abstract... 2019.

    Abstract: Titanium dioxide is a semiconductor employed as catalyst in the photodegradation of organic pollutants and bacteria. However, due to its large band gap TiO2 only can be excited by UV light. Recently, TiO2 doping with metals or nonmetals elements has been extensively exploited to allow its use under visible light. In the present work, nitrogen-doped and undoped TiO2 films were grown on borosilicate substrates at 400 ° C for 60 minutes by metallorganic chemical vapor deposition (MOCVD). Titanium isopropoxide IV was used as precursor of titanium and oxygen, and ammonia as nitrogen source. Ammonia was incorporated into the films in three different quantities during the growth. The effect of nitrogen contents on the structural and surface properties of TiO2 catalysts was evaluated. Both doped and undoped films presented rounded well-defined anatase grains. XPS analyses revealed that values of 1.6; 2.4 and 7.3 at% of nitrogen were incorporated into the films by varying the ammonia flux during the growth. Degradation assays have shown that nitrogen-doped TiO2 films exhibited high photocatalytic activity under visible light irradiation. Undoped films did not present activity in this condition. The better catalytic performance under visible light, 55% of dye degradation, was attributed to the film containing 2.4 at% of nitrogen. The results suggest that nitrogen-doped TiO2 catalysts grown by MOCVD have great potential to be used in the treatment of water under sunlight.

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  • IPEN-DOC 26768

    CASTRO, PEDRO A.A. de ; ZEZELL, DENISE M. . Infrared Spectroscopy evaluation of burn wound healing: semi-quantitative study. In: QUINCY BROWN, J. (Ed.); VAN LEEUWEN, TON G. (Ed.) EUROPEAN CONFERENCES ON BIOMEDICAL OPTICS, June 23-27, 2019, Munich, Germany. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 1107304-1 - 1107304-4. (Proceedings of SPIE-OSA Vol. 11073, Clinical and Preclinical Optical Diagnostics II). DOI: 10.1117/12.2527051

    Abstract: Wound healing is a biological response in order to recover the tissue stability after injury. The impaired healing by thirddegree, when the damage achieves the major part of dermis, is defined in four sequential and overlapping phases: Inflammation, transition, proliferative and maturative1. The role of biochemical cascade associated in each phase are still not fully understood, thus systematic evaluations tests are crucial. In fact, the gold standard to interrogate the molecular signature of wound healing is concern on immunohistochemical analysis. This approach tends to be laborious, timeconsuming and require multiple assays2. Since Fourier transform infrared spectroscopy (FTIR) has been demonstrated in other studies to provide molecular change report upon biological samples, the present study aims to estimate the feasibility of FTIR to discriminate healthy and burned skin throughout wound stages.

    Palavras-Chave: burns; wounds; infrared spectra

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  • IPEN-DOC 26767

    LOPES, MONICA S.; MOTA, CLAUDIA C.B.O.; PEREIRA, DAISA L. ; AMARAL, MARCELLO M.; ZEZELL, DENISE M. ; GOMES, ANDERSON S.L.. Effect of Nd:YAG laser and aluminum oxide sandblasting preconditioning on lingual enamel: brackets shear bond strength and morphological characterization. In: WOJTKOWSKI, MACIEJ (Ed.); BOPPART, STEPHEN A. (Ed.); OH, WANG-YUHL (Ed.) EUROPEAN CONFERENCES ON BIOMEDICAL OPTICS, June 23-27, 2019, Munich, Germany. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 1107822-1 - 1107822-3. (Proceedings of SPIE-OSA Vol. 11078, Optical Coherence Imaging Techniques and Imaging in Scattering Media III). DOI: 10.1117/12.2527030

    Abstract: It is known that Nd:YAG laser radiation on dental structure can increase enamel resistance to demineralization; however, few studies report its impact in orthodontics. This study aimed to verify the interaction of Nd:YAG laser and aluminum oxide sandblasting (Al2O3) as preconditioning treatment of lingual brackets bonding to quantify the shear bond strength (SBS) and to characterize the enamel after different surface preconditioning techniques. Thirty-five bovines’ incisors were divided in 5 groups (n=7), according to the preconditioning. All groups had the lingual brackets bonded with Transbond XT adhesive according to manufacturer’ protocol, and shear bonded after 72h. Samples were analyzed by Optical Coherence Tomography (OCT) and Scanning Eletronic Microscope (SEM) to verify enamel alterations. Optical attenuation coefficient (α) was measured before any preconditioning (T0) and after preconditioning surface (T1) for each group. Statistics analysis ANOVA-test was used, followed by Post Hoc Tukey for shear bond strength data, and Kruskal Wallis and post hoc Dunn test for α data. SEM and OCT qualitative analysis showed the melting effect with laser irradiation and enamel crystal surface disorganization with sandblasting in T1 and after shear bond. All groups were adequate for SBS and the statistical differences (p=0.0034) among groups showed better results for groups with techniques association (laser and Al2O3 used in this or in reverse order) and the highest SBS when laser was used after. The Al2O3 removes part of melting effect. The α had statistical difference (p= 0.0124) among groups, increasing with laser and Al2O3 isolated and decrease with techniques association.

    Palavras-Chave: tomography; coherent radiation; aluminium oxides; oral cavity; dentistry

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  • IPEN-DOC 26766

    LIMA, CASSIO A. ; CORREA, LUCIANA; BYRNE, HUGH J.; ZEZELL, DENISE M. . Assessing the spectrochemical signatures of skin components using FTIR microspectroscopy. In: QUINCY BROWN, J. (Ed.); VAN LEEUWEN, TON G. (Ed.) EUROPEAN CONFERENCES ON BIOMEDICAL OPTICS, June 23-27, 2019, Munich, Germany. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 110730S-1 - 110730S-3. (Proceedings of SPIE-OSA Vol. 11073, Clinical and Preclinical Optical Diagnostics II). DOI: 10.1117/12.2527137

    Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a label-free analytical technique used to evaluate the chemical profile of a sample based on its molecular vibrations. The potential dermatological applications of FTIR spectroscopy has been well demonstrated over the past decades through many proof-of-concept studies evaluating cancerous and non-cancerous cutaneous diseases. Considering that the correctly identification of skin components plays an important role in the study of cutaneous diseases, the present study aims to evaluate the spectrochemical signatures of dermis and epidermis based on the pixels of a FTIR hyperspectral image collected from healthy skin.

    Palavras-Chave: infrared spectrometers; skin; epithelium; cluster analysis

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  • IPEN-DOC 26765

    SUZUKI, M.F. ; ALMEIDA, L.A. ; POMIN, S.A. ; SILVA, F.D. ; FREIRE, R.P. ; OLIVEIRA, J.E. ; AFFONSO, R. ; BARTOLINI, P. ; SOARES, C.R.J. . Expression of the human prolactin antagonist delta 1-11 G129R-PRL in E. coli periplasm. In: SANTOS, NATHALIA V. dos (Ed.) BIOPARTITIONING & PURIFICATION CONFERENCE, November 11-13, 2019, Guarujá, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Microbiologia, 2019. p. 110-110.

    Abstract: Recombinant human prolactin antagonist delta 1-11 G129R-hPRL is a 21.9 kDa protein with 188 amino acids that downregulates the proliferation of a variety of cells expressing prolactin receptors. Periplasmic expression of recombinant proteins in E. coli has been considered an option for obtaining an authentic, soluble, and correctly folded protein, as an alternative to the cytoplasmic production in inclusion bodies of an unfolded, insoluble protein, carrying an extra initial methionine. The aim of this work was to carry out the expression of delta 1-11 G129R-hPRL antagonist in the periplasm of E. coli, testing different temperatures. E. coli BL21(DE) strain, transformed with a plasmid based on a pET25b(+) vector, DsbA signal peptide and delta 1-11 G129R-hPRL cDNA, was cultured in LB medium with ampicillin addition. After overnight culture at 30 °C, 0.6 mM IPTG was added and five different temperatures were applied: 25, 30, 32, 35 and 37 °C. Periplasmic fluid was extracted after 5 hours by osmotic shock. The samples were analyzed by SDS-PAGE, Western blotting and RP-HPLC. The best condition was increasing the temperature to 35 °C for 5 h, after having reached the late log phase. The specific expression of 0.14 ± 0.02 μg/mL/A600, with a final optical density of 3.43 ± 0.13 A600 (n = 3) was obtained. Purification by nickel affinity chromatography (Hisprep FF) with Imidazole elution followed by size exclusion chromatography (Sephacryl S-100) was carried out connected to an ÄKTA purification system. Quantification was carried out by comparison between the areas under the curve observed in the HPSEC chromatogram, for the unknown samples versus the Internal Standard of rec-hPRL. The final product showed >95% purity by HPSEC analysis. The delta 1-11 G129R-hPRL antagonist was expressed and purified for further in vivo and in vitro tests, in view of clinical applications for inhibiting cancer cell proliferation that overexpresses prolactin receptor and studies related to prolactin function in anterior pituitary.

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  • IPEN-DOC 26764

    FERREIRA, MERILYN S. ; PASK, HELEN M.; WETTER, NIKLAUS U. . Yellow laser at 573 nm generated by intracavity SHG diodeside-pumped Raman laser. In: ADVANCED SOLID STATE LASERS, September 29 - October 3, 2019, Vienna, Austria. Resumo expandido... Washington, DC, USA: OSA, 2019. (Laser Congress 2019 (ASSL, LAC, LS&C)).

    Abstract: A diode side-pumped Nd:YLiF4 crystal for fundamental wavelength generation and intracavity Stokes conversion in KGW are employed to obtained 6.1W maximum output power, 11.9% slope efficiency and 11.8% diode-to-yellow conversion efficiency at 573 nm.

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  • IPEN-DOC 26763

    PETRI, ANNA R.; MALAFRONTE, ALEXANDRE A.; GONCALVES, JOSEMARY A.C. ; BARROS, SUELEN F.; BUENO, CARMEN C. ; MAIDANA, NORA L.; MANGIAROTTI, ALESSIO; MARTINS, MARCOS N.; VANIN, VITO R.. Study of the response of a commercial photodiode for photons and electrons with energies between 10 and 100 keV. In: IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE; INTERNATIONAL SYMPOSIUM ON ROOM-TEMPERATURE X-RAY AND GAMMA-RAY DETECTORS, 26th, October 26 - November 2, 2019, Manchester, UK. Abstract... Piscataway, NJ, USA: IEEE Nuclear and Plasma Sciences Society, 2019. p. 129-129.

    Abstract: In this work, a commercial low-cost silicon PIN (p type-Intrinsic-n type) photodiode model BPX 65 is characterized with respect to reverse current and capacitance of the junction. The measurements indicate that the photodiode is fully depleted for a reverse bias greater than 17 V and the width of the depletion zone is estimated to be 60 (3) μm. The device has been applied for gamma spectrometry, showing a resolution around 2.4 keV (FWHM - Full Width at Half Maximum) for photons with energies between 14 and 136 keV. This is the same resolution obtained with a pulser, 2.39 (2) keV, indicating that the main limitation of the spectroscopy system employed is electronic noise. As this is a promising detector not only for low-energy photons, but also for charged particles, the response of the BPX 65 has been investigated with a low-dispersion electron beam with energies between 20 and 100 keV. Under such conditions, the response function cannot be described as a simple Gaussian distribution. Moreover, the analytical response functions for electrons presented in the literature need to be generalized including a polynomial term. The proposed response function was tested and the behavior of the free parameters with the energy of the impinging electron is shown to be smooth. Thus, it is possible to extract from the data a well behaved parametrization.

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  • IPEN-DOC 26762

    SIERRA, JULIAN H.; CARVALHO, DANIEL O.; SAMAD, RICARDO E. ; RANGEL, RICARDO C.; ALAYO, MARCO I.. Analysis and measurement of the non-linear refractive index of SiOxNy using pedestal waveguides. In: SYMPOSIUM ON MICROELECTRONICS TECHNOLOGY AND DEVICES, 34th, August 26-30, 2019, São Paulo, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2019. DOI: 10.1109/SBMicro.2019.8919392

    Abstract: In this work, the non-linear refractive index (n2) of silicon oxynitride (SiOxNy) is determined, obtaining a value for this material of n2 = 2.11×10-19 m2/W. The results demonstrate that this material has interesting properties for the development of non-linear optical devices. The paper presents in detail the waveguide fabrication process using the pedestal technique, which allows using different materials since it does not require etching to define the sidewalls of the waveguides. We show the results of the measurement of the n2 employing the non-linear optical phenomena of Self-Phase Modulation (SPM).

    Palavras-Chave: optical equipment; photons; silicon nitrides; silicon oxides; microelectronics

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  • IPEN-DOC 26761

    OLIVEIRA, L.S. ; CORREA, O.V. ; BENTO, R.T. ; PILLIS, M.F. . Síntese de alumina anódica nanoporosa em liga de Alumínio AA 1050. In: CONGRESSO BRASILEIRO DE QUÍMICA, 59., 5-8 de novembro, 2019, João Pessoa, PB. Anais... Rio de Janeiro, RJ: Associação Brasileira de Química, 2019.

    Abstract: Nos últimos anos, alumina anódica porosa tem atraído interesse devido ao arranjo regular dos nanoporos, à possibilidade de controle de seu diâmetro, e grande área de superfície específica. Neste trabalho foram obtidas estruturas de alumina anódica porosa por meio da anodização em duas etapas de uma liga de alumínio AA 1050 em eletrólito de H2SO4. As amostras foram anodizadas durante 4 e 8 h. A técnica de microscopia eletrônica de varredura com canhão de emissão de elétrons foi utilizada para a avaliação morfológica da superfície. Os nanoporos formados após 4h de anodização apresentaram distribuição homogênea na superfície da liga e diâmetro médio de 25 nm, enquanto que após 8h de anodização os nanoporos apresentaram-se com formato irregular e distribuição não homogênea.

    Palavras-Chave: anodization; aluminium alloys; porous materials

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  • IPEN-DOC 26760

    BORAZANIAN, T.C.F. ; SZURKALO, M. ; CORREA, O.V. ; BENTO, R.T. ; SANTOS, T.F. ; COTINHO, S.P. ; PILLIS, M.F. . Revestimentos de TiO2 para preservação de superfícies cimentícias. In: CONGRESSO BRASILEIRO DE QUÍMICA, 59., 5-8 de novembro, 2019, João Pessoa, PB. Anais... Rio de Janeiro, RJ: Associação Brasileira de Química, 2019.

    Abstract: Este trabalho tem como objetivo avaliar o desempenho autolimpante de filmes fotocatalíticos de TiO2 aplicados sobre argamassa cimentícia usada como revestimento externo de vedações verticais das edificações. Os filmes foram sintetizados pelo método sol-gel e depositados por spray coating, à temperatura ambiente, sobre substratos de argamassa cimentícia. Foram testadas amostras com uma e duas camadas de deposição de filme e foram realizados testes de autolimpeza. As análises apontam que as amostras com aplicação de duas camadas de filme de TiO2 exibem degradação mais eficiente do corante azul de metileno, após 3 ciclos de 48 horas sob radiação UV, o que sugere sua aplicação promissora para preservação e manutenção de superfícies de revestimentos externos utilizados na construção civil.

    Palavras-Chave: titanium oxides; construction; cleaning; films

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  • IPEN-DOC 26759

    OLIVEIRA, E.C. de ; CORREA, O.V. ; BENTO, R.T. ; COTINHO, S.P. ; SANTOS, T.F. dos ; PILLIS, M.F. . Caracterização morfológica de filmes de TiO2 dopados com nitrogênio crescidos por MOCVD. In: CONGRESSO BRASILEIRO DE QUÍMICA, 59., 5-8 de novembro, 2019, João Pessoa, PB. Anais... Rio de Janeiro, RJ: Associação Brasileira de Química, 2019.

    Abstract: O método de deposição química de organometálicos em fase vapor (MOCVD) foi utilizado para o crescimento de filmes de dióxido de titânio (TiO2) e TiO2 dopado com nitrogênio. Os filmes foram crescidos a 400 °C sobre substratos de vidro borossilicato. Isopropóxido de titânio IV foi utilizado como precursor de titânio e de oxigênio, e amônia (NH3) como fonte de nitrogênio. Análises por microscopia de força atômica (AFM) mostraram que ambos os filmes apresentaram grãos bem definidos e arredondados. Todos os filmes são formados apenas pela fase cristalina anatase. Os resultados mostraram que a dopagem com nitrogênio resultou em uma diminuição no tamanho médio de grão e na rugosidade superficial.

    Palavras-Chave: titanium oxides; organometallic compounds; chemical vapor deposition; doped materials; nitrogen

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  • IPEN-DOC 26758

    ROVANI, S. ; CARVALHO, F. ; SANTOS, J.; RAMOS, N.; MORANDI, M.; SALDANHA, M.; FUNGARO, D. . Caracterização físico-química das propriedades de cinzas de cana-de-açúcar de diferentes usinas brasileiras. In: CONGRESSO BRASILEIRO DE QUÍMICA, 59., 5-8 de novembro, 2019, João Pessoa, PB. Anais... Rio de Janeiro, RJ: Associação Brasileira de Química, 2019.

    Abstract: O interesse em transformar biomassa em novas fontes de energia e novos materiais vem fomentando estudos em todo o mundo. As cinzas resultantes da queima de palha e bagaço de cana, por exemplo, é um material rico em sílica. No presente estudo, amostras de cinzas de resíduos de cana-de-açúcar foram coletadas nas usinas de Cerradinho (Chapadão do Céu, GO), Iracema (Iracemápolis, SP) e Guaíra (Guaíra, SP), localizadas em regiões onde os solos são classificados como Latossolos. As cinzas foram caracterizadas pelas técnicas de XRD, EDX, MEV, espectroscopia no IV e DTG. A maioria das amostras de cinzas apresentou sílica como principal constituinte (42-69%) e a sílica na forma cristalina em todas. Diferenças significativas nas concentrações de outros elementos foram observadas.

    Palavras-Chave: sugar cane; ashes; silica; biomass

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  • IPEN-DOC 26757

    BENTO, R.T. ; CORREA, O.V. ; COTINHO, S.P. ; SANTOS, T.F. dos ; PILLIS, M.F. . Avaliação do efeito da morfologia e da espessura de filmes de TiO2 na degradação do corante alaranjado de metila. In: CONGRESSO BRASILEIRO DE QUÍMICA, 59., 5-8 de novembro, 2019, João Pessoa, PB. Anais... Rio de Janeiro, RJ: Associação Brasileira de Química, 2019.

    Abstract: Filmes de TiO2 com diferentes espessuras foram crescidos por MOCVD sobre vidro borossilicato a 400°C. Os efeitos das características morfológicas e da espessura dos filmes sobre sua atividade fotocatalítica foram avaliados a partir da degradação do corante alaranjado de metila sob luz UVA. Os resultados apontaram a existência de um valor ideal de espessura, no qual o catalisador exibe o melhor desempenho fotocatalítico. O filme de TiO2 com espessura de 470 nm exibiu o melhor comportamento, com uma eficiência de 65,3 % em 5 horas de uso. O filme apresentou uma elevada estabilidade fotocatalítica, após diversos ciclos de utilização, o que permite a sua aplicação prática no tratamento de água a partir de um método verde, e com alta durabilidade e eficiência

    Palavras-Chave: titanium oxides; organometallic compounds; chemical vapor deposition; photocatalysis

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  • IPEN-DOC 26756

    PIERETTI, E.; BORAZANIAN, T. ; CORREA, O. ; PILLIS, M. ; ANTUNES, R.. Análise eletroquímica de um biomaterial revestido por TiO2. In: CONGRESSO BRASILEIRO DE QUÍMICA, 59., 5-8 de novembro, 2019, João Pessoa, PB. Anais... Rio de Janeiro, RJ: Associação Brasileira de Química, 2019.

    Abstract: O presente trabalho avaliou, por técnicas eletroquímicas, superfícies do aço inoxidável austenítico ISO 5832-1 recobertas com filmes de TiO2, sintetizados pelo método sol-gel. As técnicas eletroquímicas utilizadas foram: monitoramento de potencial de corrosão em circuito aberto em função do tempo de imersão em solução de Ringer, que simula os fluidos corpóreos; espectroscopia de impedância eletroquímica e cálculo de densidades de dopantes no filme passivo por meio da abordagem de Mott-Schottky. Amostras deste mesmo biomaterial sem recobrimento foram analisadas para fins de comparação. Os resultados indicaram diminuição da susceptibilidade à corrosão localizada nas amostras recobertas por TiO2, devido ao caráter aderente e protetor dos filmes depositados nas superfícies deste biomaterial.

    Palavras-Chave: stainless steels; films; titanium oxides; surgical materials; biological recovery

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  • IPEN-DOC 26755

    PEREIRA, DAISA L. ; DEL VALLE, MATHEUS; GOMES, GABRIELA V. ; ZEZELL, DENISE M. ; ANA, PATRICIA A.. Optical properties of bovine dentin when irradiated by Nd:YAG and a black dentifrice aimed at treating dentin erosion. In: COSTA-FELIX, RODRIGO (Ed.); MACHADO, JOÃO C. (Ed.); ALVARENGA, ANDRÉ V. (Ed.) BRAZILIAN CONGRESS ON BIOMEDICAL ENGINEERING, 26th, October 21-25, 2018, Armação de Buzios, RJ. Proceedings... Singapore: Springer Nature Singapore, 2019. p. 847-850. (IFMBE Proceedings 70/2). DOI: 10.1007/978-981-13-2517-5_131

    Abstract: Dental erosion has been extensively studied as a risk factor for tooth loss or injure, and the early diagnosis of lesions is essential for avoiding greater damages. Optical Coherence Tomography (OCT) is a potential tool for early diagnosis of demineralization. In this study, this technique was used to analyze the optical changes of dentin samples irradiated with Nd:YAG laser using a black dentifrice as photoabsorber, then submitted to an erosive cycling. 75 slabs of bovine root dentin were randomized into 5 groups: G1—untreated; G2—treated with acidulated phosphate fluoride gel (APF-gel, [F-] = 1.23%, pH = 3.3–3.9); G3—irradiated with Nd: YAG laser (100 μs, 1064 nm, 0.6 W, 10 Hz) without photoabsorber; G4—irradiated with Nd:YAG laser using a coal paste as photoabsorber; G5—irradiated with Nd: YAG laser using a black dentifrice as photoabsorber. All samples were submitted to a 3-day erosive demineralization (Citric acid 1%, pH = 3.6, 5 min, 2 /day) under agitation, and remineralization (artificial saliva, pH = 7, 120 min) cycling. The samples were evaluated by OCT before treatments (baseline), after treatments and after erosive cycling. Optical attenuation coefficient (μ) was calculated using a Matlab routine, and the statistical analysis was performed (a = 0.05). It was observed a significant decrease on μ values after all treatments. Also, the μ values decreased after erosive cycling, except for the groups G3 and G5. It was concluded that OCT technique is capable to distinguish among sound, treated and demineralized dentin. As well, the black paste was efficient to act as a photoabsorber, helping the Nd:YAG laser to decrease dentin erosion.

    Palavras-Chave: dentistry; dentin; caries; teeth; cattle; lasers; optical properties; infrared spectra

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  • IPEN-DOC 26754

    FERREIRA, ELIZABETE dos S.; PRATES, ILKA T.K.; SANTOS JUNIOR, SERGIO L.M. dos; DEL VALLE, MATHEUS; ZEZELL, DENISE M. ; ANA, PATRICIA A.. In vitro study of Er,Cr:YSGG laser effects when used for the prevention of dentin demineralization. In: COSTA-FELIX, RODRIGO (Ed.); MACHADO, JOÃO C. (Ed.); ALVARENGA, ANDRÉ V. (Ed.) BRAZILIAN CONGRESS ON BIOMEDICAL ENGINEERING, 26th, October 21-25, 2018, Armação de Buzios, RJ. Proceedings... Singapore: Springer Nature Singapore, 2019. p. 825-829. (IFMBE Proceedings 70/2). DOI: 10.1007/978-981-13-2517-5_127

    Abstract: Erbium lasers can be used to prevent dental caries, which has a high prevalence in the worldwide population. However, effective irradiation parameters for root dentin have not yet been determined using the Er,Cr:YSGG laser. Objective: this study evaluated the chemical, morphological and optical effects of Er,Cr:YSGG laser on root dentin when aimed at preventing root caries. Methodology: 75 bovine root dentin slabs were randomly distributed in 5 groups: G1-untreated; G2-treated with acidulated phosphate fluoride gel (APF-gel, [F−]= 1.23%); G3-Er,Cr: YSGG laser irradiation (2.78 μm, 60 μs, 6 J/cm2, 8,67 mJ/pulse, 0.25 W); G4-Laser irradiation + APF-gel application; G5-APF-gel application + Laser irradiation. The chemical and morphological evaluations were performed using Fourier transformed infrared spectroscopy and scanning electron microscopy, respectively. Afterwards, the samples were submitted to an 8-day pH-cycling model and the optical attenuation coefficient was evaluated by optical coherence tomography. The statistical analysis was performed considering the level of significance of 5%. Laser irradiation alone does not alter the dentin composition, but the previous application of APF-gel followed by laser irradiation significantly decreased the content of m3m4 carbonate of dentin. This treatment also promoted greater morphological alterations, such as ablation of the surface, when compared to the treatments alone. After demineralization, this treatment also presented the highest optical attenuation coefficient value when compared to the other treatments, indicating less demineralization of the samples. Conclusion: Er,Cr: YSGG laser presents potential for use in prevention of root dentin demineralization, and is more efficient when preceded by the application of APF.

    Palavras-Chave: dentistry; dentin; caries; erbium; roots; teeth; lasers; biological radiation effects; demineralization

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  • IPEN-DOC 26753

    PANESI, RICARDO ; BERUSKI, OTAVIO ; KORKISCHKO, IVAN ; OLIVEIRA NETO, ALMIR ; SANTIAGO, ELISABETE . Modeling and parametric analysis of PEM fuel cells using computational fluid dynamics. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 25th, October 20-25, 2019, Uberlândia, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2019.

    Abstract: This paper presents a parametric investigation of PEMFC electrochemical models employing computational fluid dynamics (CFD) technique and aims to determine the relative importance of each parameter on the modeling results. A compatible and systematic mathematical model is developed in order to study the effect of these parameters. The model is applied to an isothermal, steady state an single phase to observe the main results by a polarization curve. The results compare well with the experimental polarization data obtained at 80 ºC for ohmic and activation regions. The best match with the experimental data is obtained when the specific active surface area of the catalyst layer is 700 cm2/mg and electrolyte conductivity of 8 S/m.

    Palavras-Chave: computerized simulation; fluid mechanics; proton exchange membrane fuel cells; fuel cells; numerical analysis; simulation

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  • IPEN-DOC 26557

    GOMES, JOAO P.C. ; SOUZA, KATIA R. de; PEDRIALI-MORAES, CARLA A.; SEO, EMILIA S.M. . Sabonete com base auto-emulsionante polimérica A/O com potencial repelente. In: CONGRESSO LATINO-AMERICANO E IBÉRICO DE QUÍMICOS COSMÉTICOS, 24., 21-23 de maio, 2019, São Paulo, SP. Anais... 2019. p. 1-11.

    Abstract: O uso de repelentes é uma proteção individual, a qual é de extrema importância para evitar os surtos promovidos pela febre amarela, dengue, febre Chikungunya e o vírus Zika. Os repelentes mais eficazes são os tópicos convencionais com ativos sintéticos e naturais. Como alternativa mais efetiva existem os repelentes tópicos convencionais, que podem ser sintéticos ou naturais. Para minimizar os riscos de esquecimento ou do uso incorreto dos repelentes tópicos convencionais (como em forma de creme, gel ou líquido), este trabalho teve a proposta alternativa do desenvolvimento do sabonete com poliamida 3, sendo uma base sabonete com potencial de repelência. Sua vantagem, além da praticidade, é assegurar a proteção do usuário desde o banho formando um filme resistente à água e assim, evitar a não proteção em razão do esquecimento do uso dos cremes ou sprays. O filme formado sobre a pele é oriundo da junção da Polyamide 3 Resin com os emolientes: Propylene Glycol Dicaprylate/ Dicaprate, Isopropyl Myristate, Isostearyl Alcohol e Isostearyl Isostearate. Os ativos Cymbopogon nardus e Ethyl butylacetylaminopropionate promovem a repelência. A base dos sabonetes moldado e gel cremoso foi mais estável quando a poliamida é submetida a alta temperatura para a incorporação dos emolientes a sua estrutura. Os ativos estudados tiveram melhor eficácia quando o sabonete esteve com o pH na faixa 5,5 à 6,3. As formulações base e com o ativo óleo essencial de citronela apresentaram mínima alteração no pH.

    Palavras-Chave: other organic compounds; soaps; emulsification; organic polymers

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  • IPEN-DOC 26560

    CABRAL, FERNANDA V. ; RIBEIRO, MARTHA S. . Methylene blue-mediated photodynamic therapy on cutaneous leishmaniasis: an in vitro and in vivo study. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 17th, June 28 - July 4, 2019, Cambridge, Massachusetts, USA. Abstract... 2019.

    Abstract: Cutaneous leishmaniasis (CL) is a neglected disease, which promotes destructive lesions. Difficulties in treatment are related to resistance and toxicity. Methylene blue-mediated photodynamic therapy (MB-PDT) has emerged as a promising treatment considering low cost and no reports about resistance. We evaluated MB-PDT on Leishmania amazonensis in vitro and in vivo using a red LED at different fluences. Our results demonstrated that the best fluence in vitro was not effective in vivo, and a higher dose was necessary to provide better responses in mice. This study reinforces the idea that a well-planned protocol is necessary for a successful MB-PDT on CL.

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  • IPEN-DOC 26559

    SABINO, CAETANO P.; BAPTISTA, MAURICIO S.; RIBEIRO, MARTHA S. ; LINCOPAN, NILTON. The mechanisms of bacterial inactivation via MB-APDT avoid drug resistance. In: HASAN, TAYYABA (Ed.) INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 17th, June 28 - July 4, 2019, Cambridge, Massachusetts, USA. Abstract... Bellingham, WA, USA: SPIE, 2019. (Proceedings SPIE 11070).

    Abstract: Antimicrobial photodynamic therapy (APDT) is trending as a powerful therapeutic platform to minimize the negative impacts of microbial drug resistance. The mechanisms of action of APDT are imposed as a generalized oxidation of all cellular structures. Therefore, is assumed that the development of resistance to APDT is very unlikely to occur due to its multitarget oxidative effects. Even though the instant effects of APDT may be interesting to several situations, the few microbial cells left alive after irradiation procedure may be enough to allow tissue recolonization. Therefore, to ensure higher effectiveness of APDT protocols should also rely on therapeutic combinations with longer lasting effects. In this study, we report the statistical correlation of bacterial inactivation rate with the degradation rate of lipids, proteins and DNA. We observed that APDT mediated by methylene blue (MB) and red light can induce degradation of enzymes associated with drug resistance. Thus, cells exposed to sublethal doses of MB-APDT may recover sensitivity to antibiotics they were previously resistant. This fact may lead to a time interval where highly resistant pathogens become sensitive to most standard drugs, such as penicillin. Additionally, we observed that drug-resistance genes present in bacterial DNA are severely damaged. Hence, drug resistance gene expression and/or dissemination to other cells should also be impaired. In summary, we can conclude that APDT also challenges drug resistance by degradation of related enzymes and DNA.

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  • IPEN-DOC 26558

    GARCEZ, AGUINALDO S.; NARDINI, ELISA F.; CARDOSO, RIELSON; RIBEIRO, MARTHA S. . The potential of phytotherapeutic compounds available on the market as a new photosensitizers for dental antimicrobial PDT: a photochemical and photobiological in vitro study. In: HASAN, TAYYABA (Ed.) INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 17th, June 28 - July 4, 2019, Cambridge, Massachusetts, USA. Abstract... Bellingham, WA, USA: SPIE, 2019. (Proceedings SPIE 11070).

    Abstract: This study evaluated Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum available on the market as photosensitizers (FS) in Antimicrobial Photodynamic Therapy (aPDT). Each FS were analyzed in a spectrophotometer between 350 and 750 nm, to determine the ideal light source. Once the absorption bands were determined, 3 light sources were selected to determine the concentration of use, the compounds were verified at different concentrations on bovine dentin samples to evaluate the risk of staining. Once the concentration was determined, FS were evaluated for cytotoxicity on fibroblast culture. Each compound was then irradiated with each light source and evaluated for indirect reactive oxygen species (ROS) production. The bacterial reduction was tested in culture of E. faecalis in planktonic form and in biofilm using energy of 10 J and Energy Density of 26 J/cm2. The tested compounds had light absorption in three bands of the visible spectrum: violet (405 nm), blue (470 nm) and red (660 nm). At 1:6 concentration, none of the compounds promoted tooth staining, as none of the compounds showed significant toxicity in cells or bacterial suspension. In addition, when the compounds were irradiated at each wavelength, significant ROS production was observed. When the aPDT was performed on the planktonic and biofilm bacteria, significant microbial reduction was observed for both cases, reaching up to 5Logs of reduction. In conclusion, extracts of Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum, showed potential for use in aPDT as photosensitizing agents.

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A pesquisa no RD utiliza os recursos de busca da maioria das bases de dados. No entanto algumas dicas podem auxiliar para obter um resultado mais pertinente.

✔ É possível efetuar a busca de um autor ou um termo em todo o RD, por meio do Buscar no Repositório , isto é, o termo solicitado será localizado em qualquer campo do RD. No entanto esse tipo de pesquisa não é recomendada a não ser que se deseje um resultado amplo e generalizado.

✔ A pesquisa apresentará melhor resultado selecionando um dos filtros disponíveis em Navegar

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Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

✔ Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

✔ 95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, bibl@ipen.br .

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O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.