IPEN: Recent submissions

  • IPEN-DOC 27719

    SMITH, R.B. ; SALVETTI, T.C. ; TESSARO, A.P.G. ; MARUMO, J.T. ; VICENTE, R.V. . Knowledge management in the decommissioning of nuclear facilities in Brazil. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-15, 2020. DOI: 10.15392/bjrs.v8i3A.1315

    Abstract: In the second half of the twentieth century in Brazil, several nuclear facilities were built for the most varied objectives. The largest number of such facilities is at the Nuclear and Energy Research Institute in São Paulo (IPEN-CNEN/SP). For different reasons, some of these facilities had their projects finalized and were deactivated. Some of the equipment was then dismantled, but the respective nuclear and radioactive material remained isolated in the original sites waiting for the proper decommissioning procedures. The Celeste Project is an example of a facility where the nuclear material has been kept, and is subject to Argentine-Brazilian Agency for Accounting and Control of Nuclear Materials (ABACC) periodic inspections. Because of a number of interests, including financial and/or budgeting situations at the institutions, decades have passed without any further action; the people who originally worked there, and possessed information and knowledge about these facilities, have already moved away from the area, or are in the process of. Therefore, because of the absence of knowledge management techniques in force at the time of establishing and operating these installations, this work proposes an analysis about the possible consequences in case of loss of perhaps the only one remaining knowledge, the one from the people who designed those departments and worked there.

    Palavras-Chave: decommissioning; historical aspects; information dissemination; information needs; knowledge management; nuclear facilities; radioactive materials; radioactive waste management; safety; brazilian cnen

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  • IPEN-DOC 27718

    PUGLIESI, R. ; STANOJEV PEREIRA, M.A. ; ANDRADE, M.L. . Concentration and distribution of oil in the reservoir mineral Dolomite studied by neutron tomography. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-12, 2020. DOI: 10.15392/bjrs.v8i3A.1291

    Abstract: Neutron Tomography – NT is a non-destructive technique, ideal for imaging hydrogen-rich substances even when wrapped up by thick rock layers. In the present study, the NT was employed for investigating the oil concentration and distribution in the mineral Dolomite, a natural oil reservoir. Two types of Dolomite samples, one of which dry, and the second one in oil-saturated were prepared. The applied oil was EMCAplus® 070 usually employed in permeability experiments to reproduce conditions of natural oil reservoirs. Three small fragments of the dry sample and three of the oil sample were inspected by NT and the comparison between the obtained results enabled, to distinguish several regions in which the oil is stored, to indicate that the oil is dispersed throughout the volume of the samples, and to quantify the storage concentration. The obtained data for oil concentration, for the three fragments, were compared to each other and to the one obtained by the conventional gravimetric technique, and they agreed within their uncertainties, demonstrating the viability of the NT technique to inspect, either in a qualitative as in a quantitative level, this oil reservoir mineral.

    Palavras-Chave: concentration ratio; distribution; dolomite; neutrons; petroleum; petroleum deposits; prospecting; scanning electron microscopy; tomography

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  • IPEN-DOC 27717

    CURBELO, J.P.; LIBOTTE, R.B.; OLIVA, A.M.; BARROS, R.C.; ALVES FILHO, H.. The modified spectral deterministic method applied to fixed–source discrete ordinates problems in X, Y–geometry. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-14, 2020. DOI: 10.15392/bjrs.v8i3A.1268

    Abstract: A new approach for the application of the coarse–mesh Modified Spectral Deterministic method to numerically solve the two–dimensional neutron transport equation in the discrete ordinates (𝑺𝑵) formulation is presented in this work. The method is based on within node general solution of the conventional one–dimensional 𝑺𝑵 transverse integrated equations considering constant approximations for the transverse leakage terms and obtaining the 𝑺𝑵 spatial balance equations. The discretized equations are solved by using a modified Source Iteration scheme without additional approximations since the average angular fluxes are computed analytically in each iteration. The numerical algorithm of the method presented here is algebraically simpler than other spectral nodal methods in the literature for the type of problems we have considered. Numerical results to two typical model problems are presented to test the accuracy of the offered method.

    Palavras-Chave: algorithms; deterministic estimation; discrete ordinate method; finite difference method; green function; neutron leakage; neutron transport theory; nodal expansion method

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  • IPEN-DOC 27716

    FIGUEIREDO, C.D.R. ; MATTAR NETO, M. . Recommendation for linearization procedure in nuclear pressure vessel-nozzle intersections. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-13, 2020. DOI: 10.15392/bjrs.v8i3A.1572

    Abstract: The pressure vessel design is a fundamental step during the construction of new pressurized water reactors (PWRs). In these facilities, several safety requirements are necessary to guarantee the protection of workers, community and environment against the release of radioactive materials. The Design by Analysis is the procedure presented in the ASME Code, Section III, for nuclear components, which consist of rigorous analysis and classification of all types of stresses and loading conditions to incorporate smaller safety factors increasing the general safety. The limits presented in the ASME Code, Section III, were based on the shell theory. However, precise rules for achieving the various stress categories, in solid finite element analysis, have not been implemented yet in the code. For this reason, this work presents a methodology for the linearization procedure of elastic stresses in pressure vessel-nozzle intersections. Therefore, a vessel was modelled in tridimensional solid finite elements, analyzed and verified as a nuclear component. Then, a discussion of how to perform the code verifications was presented, as well as a mapping of stresses. The lines that were constructed in pressure vessel between transition and structural elements in the longitudinal plane (0º) and lines in structural elements in the nozzle in the transversal plane (90º) present higher stresses and are compared with the ASME Code, Section III limits.

    Palavras-Chave: a codes; design; finite element method; mesh generation; nozzles; pressure vessels; pwr type reactors; stress analysis

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  • IPEN-DOC 27715

    BUSTILLOS, OSCAR V. . Mobilidade iônica acoplada a espectrometria de massas. Revista Analytica, v. 111, p. 21-23, 2021.

    Palavras-Chave: mass spectroscopy; ion mobility; electron capture; electron detection; isomers; drugs

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  • IPEN-DOC 27714

    BUSTILLOS, OSCAR V. . O espectro de massas na espectrometria de massas. Revista Analytica, v. 110, p. 24-26, 2021.

    Palavras-Chave: mass spectra; mass spectroscopy; ion sources; chemical analysis; electron scanning; ionization

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  • IPEN-DOC 27713

    LIMA, VERA M.F. de ; PEREIRA JUNIOR, ALFREDO; OLIVEIRA, GUILHERME L. de. The spreading depression propagation: how electrochemical patterns distort or create perception. Open Journal of Biophysics, v. 11, n. 2, p. 133-146, 2021. DOI: 10.4236/ojbiphy.2021.112003

    Abstract: At the transition from quiescence to propagating waves recorded in isolated retinas, a circular electric current closes in the extracellular matrix; this circular current creates a magnetic torus flow that, when entering quiescent tissue in front of the wave, recruits elements and when leaving behind, helps to build the absolute refractory state. The waving magnetic torus is the consequence of the vortex effect and explains the energy boost that drives propagation. Methods: We interpret experimental results from intrinsic and extrinsic fluorescence dyes, voltage, calcium and pH sensitive, optical signals from isolated retinas, and time series recordings using ion exchange resins: Ca, K, pH, Na, Cl recorded extracellularly at retinas, cerebellums and cortices coupled to spreading depression waves. Finally, we checked the ECoG activity, also a time series, at the transition from after discharges to spreading depression in rat hippocampus. Results: The integrated assessment of the diversified measurements led to the realization that the magnetic flow at the wavefront is a major contributor to the wave propagation mechanisms. This flow couples mass and charge flows as a swirling torus from excited to quiescent tissue. Conclusions: An alternative model of the brain is possible, apart from the classical HH and molecular biology model. Physical chemistry of charged gels and its flows explains the results. The conceptual framework uses far from equilibrium thermodynamics.

    Palavras-Chave: brain; electrochemistry; retina; resonance; central nervous system; vortices; vortex flow

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  • IPEN-DOC 27712

    KLUMPP, RAFAEL E. ; DONATUS, UYIME ; SILVA, REJANE M.P. da ; ANTUNES, RENATO A.; MACHADO, CARULINE de S.C. ; MILAGRE, MARIANA X. ; ARAUJO, JOAO V. de S. ; VIVEIROS, BARBARA V.G. de ; COSTA, ISOLDA . Corrosion protection of the AA2198-T8 alloy by environmentally friendly organic-inorganic sol-gel coating based on bis-1,2-(triethoxysilyl) ethane. Surface and Interface Analysis, v. 53, n. 3, p. 314-329, 2021. DOI: 10.1002/sia.6919

    Abstract: In this work, a surface coating composed of organic‐inorganic hybrid sol‐gel based on bis‐1,2‐(triethoxysilyl) (BTSE) ethane was applied on AA2198‐T8 samples, and its effect on corrosion resistance was investigated and compared with that of a chromate layer formed in a solution with hexavalent chromium ions. The corrosion resistance of BTSE coated samples was evaluated by immersion tests in sodium chloride solution (0.005 mol/L NaCl) and monitored by global electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and local electrochemical techniques such as scanning vibrating electrode technique (SVET) and scanning electrochemical microscopy (SECM). The formed coating layers were characterized by X‐ray photoelectron spectroscopy (XPS). The results pointed out that the BTSE is an effective alternative coating for corrosion protection of new generation Al‐Cu‐Li alloys and could replace chromates obtained in toxic and carcinogenic CrVI containing solutions leading to improved corrosion protection.

    Palavras-Chave: corrosion; corrosion protection; surface coating; silanes; aluminium alloys; sol-gel process; hybrid systems; corrosion resistance

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  • IPEN-DOC 27711

    NUNES, MARIO A.B.S.; MATOS, BRUNO R. de ; SILVA, GLAURA G.; ITO, EDSON N.; MELO, TOMAS J.A. de; FECHINE, GUILHERMINO J.M.. Hybrids nanocomposites based on a polymer blend (linear low-density polyethylene/poly(ethylene-co-methyl acrylate) and carbonaceous fillers (graphene and carbon nanotube). Polymer Composites, v. 42, n. 2, p. 661-677, 2021. DOI: 10.1002/pc.25856

    Abstract: Interfacial or separate phase location of carbonaceous nanofillers (graphene and carbon nanotubes) in polymer blends with co-continuous phases can lead to double percolation behavior, significantly increasing rheological and electrical properties. The prediction of the morphology and the location of the nanofillers has been used as a tool to evaluate the proprieties of co-continuous polymer blends. This work aims to highlight the superior conductivity levels achieved using a low amount of carbon-based fillers, by the proper selection in a multiphase polymer matrix as a template for controlled dispersion and spatial distribution of the nanoparticles, offering a compromise between easy processability and enhanced performance. Here, two polymers (linear low-density polyethylene [LLDPE] and ethylene-co-methylacrylate [EMA]) and their cocontinuous blend (LLDPE/EMA) were loaded with nanofillers (few-layer graphene [FLG], few-walled carbon nanotube [FWCNT]) via continuous melt mixing in twin-screw extrusion, separate and simultaneously. It was observed that the addition of the nanofillers changed the co-continuity of the blend, with the probable migration of the nanofillers from the EMA (hydrophilic) phase to the LLDPE (hydrophobic) phase. Rheological percolation occurred preferentially in blends containing FWCNT and FLG/FWCNT. Electrical conductivity was observed in all compositions, with higher electrical conductivity being noticed in hybrids.

    Palavras-Chave: nanocomposites; hybridization; nanotechnology; polyethylenes; polymers; electric conductivity; carbon nanotubes; graphene

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  • IPEN-DOC 27710

    ZANINI, NATHALIA A. ; RABELO, THAIS F. ; ZAMATARO, CLAUDIA B. ; CARAMEL-JUVINO, AMANDA ; ANA, PATRICIA A.; ZEZELL, DENISE M. . Morphological, optical, and elemental analysis of dental enamel after debonding laminate veneer with Er,Cr:YSGG laser: a pilot study. Microscopy Research and Technique, v. 84, n. 3, p. 489-498, 2021. DOI: 10.1002/jemt.23605

    Abstract: Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty‐four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer). Then each agent was debonded using Er,Cr:YSGG laser (2.78 μm) using two different protocols:3.5 W, 48.14 J/cm2, 20 Hz non‐contact and 3.0 W, 48.14 J/cm2, 20 Hz non‐contact. The morphological, optical, and elemental analysis of enamel was performed before cementation and after laser debonding, using scanning electron microscopy (SEM), optical coherence tomography (OCT), and energy‐dispersive X‐ray spectroscopy (EDS). The level of statistical significance adopted was 5%. The EDS analysis of enamel after debonding revealed a significant increase in silane and carbon, as well as a decrease in calcium and phosphate contents. Analysis showed the presence of residual cement in most experimental groups but the morphological analysis showed alteration of the enamel's prisms only in the groups that used RelyX Veneer and Variolink Veneer cements. There was no evidence of deleterious morphological changes resulting from irradiation. However, an increase in the optical attenuation coefficient by the OCT was observed due to the presence of the remaining cement. It can be concluded that the Er,Cr:YSGG laser, in the mean powers used, is efficient for veneer removal without causing deleterious effects for the enamel.

    Palavras-Chave: dentistry; enamels; lasers; laser radiation; lithium; tomography; optical properties; coherent radiation; teeth

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  • IPEN-DOC 27709

    GODOI, C.M. ; SANTOS, M.C.L. ; SILVA, A.J. ; TAGOMORI, T.L.; RAMOS, A.S. ; SOUZA, R.F.B. de ; OLIVEIRA NETO, A. . Methane conversion to higher value‑added product and energy co‑generation using anodes OF PdCu/C in a solid electrolyte reactor: alkaline fuel cell type monitored by differential mass spectroscopy. Research on Chemical Intermediates, v. 47, n. 2, p. 743-757, 2021. DOI: 10.1007/s11164-020-04296-4

    Abstract: PdxCuy/C catalysts combinations were employed to CH4 partial oxidation in mild condition using a solid electrolyte reactor—alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor the oxidation products obtained as methanol, dimethyl ether, methyl formate and potassium formate. It was observed that as the electrical potential of the reactor increases, the generation of products decreases. The best results for conversion of methane into methanol and energy co-generation was obtained from Pd90Cu10/ C and Pd50Cu50/ C due to better H2O activation effects and adsorption site for CH4 oxidation.

    Palavras-Chave: methane; electrocatalysts; solid electrolytes; oxidation; methanol; fourier transformation; infrared spectra; mass spectroscopy

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  • IPEN-DOC 27708

    LOPES, MONICA S.; PEREIRA, DAISA L. ; MOTA, CLAUDIA C.B. de O.; AMARAL, MARCELLO M.; ZEZELL, DENISE M. ; GOMES, ANDERSON S.L.. The lingual enamel morphology and bracket shear bond strength influenced by Nd:YAG laser and aluminum oxide sandblasting preconditioning. Clinical Oral Investigations, v. 25, n. 3, p. 1151-1158, 2021. DOI: 10.1007/s00784-020-03418-x

    Abstract: Objectives This study aimed to investigate the influence of Nd:YAG laser and aluminum oxide sandblasting on the shear bond strength (SBS) of lingual brackets and to optically analyze the behavior of the enamel morphology. Materials and methods Thirty-five bovines’ incisors teeth were divided into 5 groups (n = 7), according to the surface preconditioning: G1, control group; G2, Nd:YAG laser; G3, laser + aluminum oxide sandblasting (Al2O3); G4, Al2O3; and G5, Al2O3 + laser. All groups had lingual brackets bonded and shear debonded after 72 h. SBS values were analyzed, and the enamel morphology was evaluated by optical coherence tomography (OCT) and scanning electron microscope (SEM), before and after preconditioning surface. The optical attenuation coefficient (α) analysis was obtained from OCT images. Data analysis used the ANOVA test, followed by post hoc Tukey, Kruskal Wallis, and post hoc Dunn tests (significance of 5%). Results The SBS values presented similarly among groups, but the value of α showed statistical difference (p-value = 0.0124) between G3 and G5 with the others. Optical analyses indicated a melting on the enamel that suffered laser irradiation for G2 and G5 and crystal surface disorganization for G4. Sandblasting partially removes the melting of the laser effect (G3). Conclusion The sandblasting is a dispensable step for bonding lingual brackets, and the melting of the enamel after laser irradiation does not compromise the bracket adhesive resistance. Clinical relevance The Nd:YAG laser became an interesting tool to prevent caries and decrease prevalence of white spot lesions in orthodontic treatments, without systemic effects in patients with genetic high risks of caries.

    Palavras-Chave: dentistry; lasers; teeth; enamels; aluminium oxides; oral cavity; tongue; tomography

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  • IPEN-DOC 27707

    AZEVEDO, LUCIANA C. de ; ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; DIAS, DJALMA B. ; NASCIMENTO, SANDI S.; OLIVEIRA, FABIO F.; SILVA, LEONARDO G.A. ; FUNGARO, DENISE A. . Study of renewable silica powder influence in the preparation of bioplastics from corn and potato starch. Journal of Polymers and the Environment, v. 29, n. 3, p. 707-720, 2021. DOI: 10.1007/s10924-020-01911-8

    Abstract: In the present study, 0.5–1.5% silica powder, from sugarcane waste ash, was incorporated into corn and potato starch bioplastics doped with sodium silicate solution to improve the properties of elongation at break and increase the thermal resistance of the bioplastics. The starch-based bioplastics were produced by casting and characterized by color analyses, transparency, opacity apparent, humidity, thickness, tensile strength, elongation at break, FTIR, DSC, SEM, and biodegradation assay. The addition of 0.5% of silica powder improved the elongation at break of the corn starch-based bioplastics. The sample CS5-P0.5 presented the highest percentage of elongation at the break among the studied samples, increased from 59.2% (without silica powder) to 78.9% (with silica powder). For potato starch bioplastic the addition of 0.5% of silica powder did not improve elongation at break but increased the thermal resistance. Increased until 17 °C for PS5-P0.5 sample and until 11 °C for PS7.5-P0.5 sample. The bioplastics of potato starch were biodegraded in 5 days, and those of corn starch took almost 40 days. Silica powder inhibited the growth of fungi in starch bioplastics.

    Palavras-Chave: silica; powders; temperature dependence; thermal conductivity; sugar cane; ashes; silica; biodegradation; plastics

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  • IPEN-DOC 27706

    ASSIS, GABRIEL P.; GARCIA, RAFAEL H.L. ; DERENZO, SILAS; BERNARDO, ANDRE. Solid-liquid equilibrium of paracetamol in water-ethanol and water-propylene glycol mixtures. Journal of Molecular Liquids, v. 323, p. 1-13, 2021. DOI: 10.1016/j.molliq.2020.114617

    Abstract: Solubility is one of most important property to produce active pharmaceutical ingredients (APIs), beyond of being related to its bioavailability. In this context, itwas determined paracetamol solid-liquid equilibriumin temperatures from20 to 50 °C for two solvent systems:water - ethanol andwater - propylene glycol (PG), by refractometry method. The experimental results were compared with five thermodynamic models (Apelblat,Wilson, UNIQUAC, NRTL and λh) and data from the literature, showing good correlations for Apelblat and the best predictive fit for the NRTL model in both solvent mixtures. Maximum solubility values were observed in a 75% ethanol composition, this result being unusual and not the same with PG. the results of this work were compared with the literature and some references point to similar behavior. Optical microscopy and X-ray diffractionmeasurements of the solids in equilibrium with the liquid indicate that maximum solubility is not associated with a change in the crystalline structure of the solid

    Palavras-Chave: chemical preparation; drugs; solubility; ethanol; propylene; glycols; x-ray diffraction; thermodynamics

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  • IPEN-DOC 27705

    SILVA, ROSANA V. da; VOLTZ, HIURY; ITMAN FILHO, ANDRE; MILAGRE, MARIANA X. ; MACHADO, CARULINE de S.C. . Hybrid composites with glass fiber and natural fibers of sisal, coir, and luffa sponge. Journal of Composite Materials, v. 55, n. 5, p. 717-728, 2021. DOI: 10.1177/0021998320957725

    Abstract: Hybrid composites with synthetic and natural fibers are a good choice in the field of composites, as they combine the good mechanical performance of synthetic fibers with the advantages of natural fibers. In this work, polymeric hybrid composites associating glass fiber and natural fibers were developed. Three hybrid composites were developed: sisal/ glass, coir/glass and Luffa/glass. The composites are five-layer laminate, three layers of E-glass interspersed with two layers of natural fibers that can be sisal, coir, or Luffa sponge (Luffa Cylindrica). In addition to hybrid composites, a five-layer fiberglass composite was also manufactured. The composites were manufactured by compression molding technique using orthophthalic polyester resin as matrix. Tensile and flexural tests were performed to characterize the composites. Considering the three hybrid composites, the best behavior was observed for the sisal/glass composite, being a potential replacement for fiberglass. The order of performance was the same in the tensile and flexural tests, sisal/glass, coir/glass, and luffa/glass, in this order. In the specimen’s fracture analysis, for both tests, it was observed that the fracture was quite located with no damage in regions far from the fracture. This behavior indicates good adhesion between the layers of natural and synthetic fibers, despite the discrepancy of their properties.

    Palavras-Chave: hybridization; composite materials; fibers; coconuts; microstructure; fiberglass

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  • IPEN-DOC 27704

    OLIVEIRA, DANIEL C.F. dos S.; MONTILLA-ROSERO, ELENA; LOPES, FABIO J. da S. ; MORAIS, FERNANDO G. ; LANDULFO, EDUARDO ; HOELZEMANN, JUDITH J.. Aerosol properties in the atmosphere of Natal/Brazil measured by an AERONET Sun-photometer. Environmental Science and Pollution Research, v. 28, n. 8, p. 9806-9823, 2021. DOI: 10.1007/s11356-020-11373-z

    Abstract: We analyzed data measured by a Sun-photometer of the RIMA-AERONET network with the purpose to characterize the aerosol properties in the atmosphere over Natal, state capital of Rio Grande do Norte, at the coast of Northeast Brazil. Aerosol Optical Depth, Ångström Exponent, Volume Size Distribution, Single Scattering Albedo, Complex Refractive Index, Asymmetry Factor, and Precipitable Water were analyzed from August 2017 to March 2018. In addition, MODIS and CALIOP observations, local Lidar measurements, and modeled backward trajectories were analyzed in a case study on February 9, 2018, that consistently confirmed the identification of a persistent aerosol layer below 4 km agl. Aerosols present in the atmosphere of Natal showed monthly mean Aerosol Optical Depth at 500 nm below 0.15 (~ 75%), monthly means of the Ångström Exponent at 440–670 nm between 0.30 and 0.70 (~ 69%), bimodal Volume Size Distribution is dominantly coarse mode, Single Scattering Albedo at 440 nm is 0.80, Refractive Index - Real Part around 1.50, Refractive Index - Imaginary Part ranging from 0.01 to 0.04, and the Asymmetry Factor ranged from 0.73 to 0.80. The aerosol typing during the measurement period showed that atmospheric aerosol over Natal is mostly composed of mixed aerosol (58.10%), marine aerosol (34.80%), mineral dust (6.30%), and biomass burning aerosols (0.80%). Backward trajectories identified that 51% of the analyzed air masses over Natal originated from the African continent.

    Palavras-Chave: satellite atmospheres; sun; photometers; optical radar; optical systems; aerial monitoring; atmospheres; optical properties; dusts; environment; environmental impacts; physical properties; biomass; brazil; africa; climatic change

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  • IPEN-DOC 27703

    SENIWAL, BALJEET; FREITAS, LUCAS F. ; MENDES, BRUNO M.; LUGAO, ADEMAR B. ; KATTI, KATTESH V.; FONSECA, TELMA C.F.. In silico dosimetry of low-dose rate brachytherapy using radioactive nanoparticles. Physics in Medicine and Biology, v. 66, n. 4, p. 1-13, 2021. DOI: 10.1088/1361-6560/abd671

    Abstract: Purpose. Nanoparticles (NPs) with radioactive atoms incorporated within the structure of the NP or bound to its surface, functionalized with biomolecules are reported as an alternative to low-dose-rate seed-based brachytherapy. In this study, authors report a mathematical dosimetric study on low-dose rate brachytherapy using radioactive NPs. Method. Single-cell dosimetry was performed by calculating cellular S-values for spherical cell model using Au-198, Pd-103 and Sm-153 NPs. The cell survival and tumor volume versus time curves were calculated and compared to the experimental studies on radiotherapeutic efficiency of radioactive NPs published in the literature. Finally, the radiotherapeutic efficiency of Au-198, Pd-103 and Sm-153 NPs was tested for variable: administered radioactivity, tumor volume and tumor cell type. Result. At the cellular level Sm-153 presented the highest S-value, followed by Pd-103 and Au-198. The calculated cell survival and tumor volume curves match very well with the published experimental results. It was found that Au-198 and Sm-153 can effectively treat highly aggressive, large tumor volumes with low radioactivity. Conclusion. The accurate knowledge of uptake rate, washout rate of NPs, radio-sensitivity and tumor repopulation rate is important for the calculation of cell survival curves. Self-absorption of emitted radiation and dose enhancement due to AuNPs must be considered in the calculations. Selection of radionuclide for radioactive NP must consider size of tumor, repopulation rate and radiosensitivity of tumor cells. Au-198 NPs functionalized with Mangiferin are a suitable choice for treating large, radioresistant and rapidly growing tumors.

    Palavras-Chave: nanoparticles; radioactive materials; radioactivity; brachytherapy; dose rates; low dose irradiation; dosimetry; radiotherapy; nanomaterials; neoplasms

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  • IPEN-DOC 27702

    GUILHEN, SABINE N. ; ROVANI, SUZIMARA ; ARAUJO, LEANDRO G. de ; TENORIO, JORGE A.S.; MASEK, ONDREJ. Uranium removal from aqueous solution using macauba endocarp-derived biochar: effect of physical activation. Environmental Pollution, v. 272, p. 1-10, 2021. DOI: 10.1016/j.envpol.2020.116022

    Abstract: The main aim of this study was to evaluate options for addressing two pressing challenges related to environmental quality and circular economy stemming from wastage or underutilization of abundant biomass residue resources and contamination of water by industrial effluents. In this study we focused on residues (endocarp) from Macaúba palm (Acrocomia aculeata) used for oil production, its conversion to activated biochar, and its potential use in uranium (U) removal from aqueous solutions. Batch adsorption experiments showed a much higher uranyl ions (U(VI)) removal efficiency of activated biochar compared to untreated biochar. As a result of activation, an increase in removal efficiency from 80.5% (untreated biochar) to 99.2% (after activation) was observed for a 5 mg L 1 initial U(VI) concentration solution adjusted to pH 3 using a 10 g L 1 adsorbent dosage. The BET surface area increased from 0.83 to 643 m2 g 1 with activation. Surface topography of the activated biochar showed a very characteristic morphology with high porosity. Activation significantly affected chemical surface of the biochar. FTIR analysis indicated that U(VI) was removed by physisorption from the aqueous solution. The adsorbed U(VI) was detected by micro X-ray fluorescence technique. Adsorption isotherms were employed to represent the results of the U adsorption onto the activated biochar. An estimation of the best fit was performed by calculating different deviation equations, also called error functions. The Redlich-Peterson isotherm model was the most appropriate for fitting the experimental data, suggesting heterogeneity of adsorption sites with different affinities for uranium setting up as a hybrid adsorption. These results demonstrated that physical activation significantly increases the adsorption capacity of macauba endocarp-derived biochar for uranium in aqueous solutions, and therefore open up a potential new application for this type of waste-derived biochar.

    Palavras-Chave: aqueous solutions; vegetable oils; vegetables; coconuts; uranium; adsorption; chemical activation; activated carbon; charcoal

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  • IPEN-DOC 27701

    THEOPHILO, CAROLINA Y.S. . Quantificação de metilmercúrio, mercúrio e outros elementos tóxicos em penas de Petréis-gigantes-do-sul (Macronectes giganteus) das Shetland do Sul, Antártica / Quantification of methylmercury, mercury and others toxic elements in Southern-giant petrel (Macronectes giganteus) feathers of South Shetland Islands, Antarctica . 2020. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 151 p. Orientador: Edson Gonçalves Moreira. DOI: 10.11606/T.85.2020.tde-18032021-090330

    Abstract: A Antártica é considerada um ambiente que sofre baixo impacto antrópico, porém nas suas regiões costeiras, com uma maior atividade antrópica, observa-se o aumento de alguns elementos químicos. Dentre esses elementos existem aqueles que são essenciais para a manutenção das vias metabólicas dos organismos, essenciais ou não, quando acumulados no organismo, podem trazer prejuízos a qualquer indivíduo. As aves marinhas são bastante sensíveis a mudanças que ocorrem no ambiente e, como ocupam diferentes níveis na teia trófica, são utilizadas como biomonitores. O Petrel-gigante-do-sul (Macronectes giganteus) é uma ave marinha migratória pertencente à ordem Procellariiformes, está no topo da teia trófica, se alimentando de peixes, cefalópodes e carcaças de outros animais. Apesar de não ser uma espécie ameaçada de extinção, suas populações sofreram declínio nas últimas décadas. Existem poucos estudos sobre a concentração de elementos tóxicos nessa espécie, devido à dificuldade de coleta das amostras e da quantificação de alguns elementos. Dessa forma, o objetivo desse trabalho foi quantificar, Hg, MeHg, As, Cd, Cu, Pb e Se em penas de Petréis-gigantes- do-sul, por meio das técnicas de AAS e INAA, com o intuito de avaliar a ocorrência desses elementos nessa espécie, na região do Arquipélago das Shetland do Sul, Antártica. Por meio da comparação entre as duas técnicas, para a quantificação de Hg, foi possível concluir as melhores condições para cada uma e em quais casos devem ser utilizadas. Os resultados mostraram que as concentrações de Hg nas penas dos Petréis-gigantes-do-sul são altas, entre 1,3 e 21,2 mg kg-1, porém, essas concentrações podem refletir o fato dessa ave ocupar o topo da teia trófica. O MeHg, que é extremamente tóxico, compõe a maior parte do Hg total quantificado, como era esperado, variando entre 69,5% e 99,9% da concentração de Hg total. Esses resultados corroboram com o fato de as penas serem um mecanismo de detoxificação para aves marinhas, uma vez que o Hg se liga à queratina e fica inerte na pena, evitando efeitos deletérios nas aves. Os resultados encontrados para todos os elementos quantificados (Hg, MeHg, Cd, Cu, Pb e Se) foram semelhantes aos de alguns estudos já realizados com aves marinhas, mostrando que não há evidências de que os Petréis-gigantes-do-sul apresentem contaminação por esses elementos. Também, não foram encontradas diferenças significativas entre os elementos estudados e os três tipos de penas analisadas.

    Palavras-Chave: birds; feathers; seas; toxicity; toxic materials; sample preparation; fishes; quantization; statistical data; methylmercury; organic mercury compounds; cadmium; copper; lead; radiation monitors; contamination; neutron activation analyzers; radiation

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  • IPEN-DOC 27700

    SILVA, GRAZIELA M. da . Avaliação da radioatividade natural e artificial em farinhas comercializadas na cidade de São Paulo por espectrometria gama de alta resolução / Evaluation of natural and artificial radioactivity in flours commercialized in the city of São Paulo by high resolution gamma spectrometry . 2020. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 83 p. Orientador: Brigitte Roxana Soreanu Pecequilo. DOI: 10.11606/D.85.2020.tde-01032021-095035

    Abstract: Uma das contribuições mais relevantes para a dose efetiva recebida pelos seres humanos proveniente de fontes naturais de radiação é a dose por ingestão. As concentrações de radionuclídeos naturais em alimentos variam significativamente não apenas com os diferentes tipos de alimentos, mas também com níveis de radiação de fundo, clima e condições agrícolas. Na literatura, poucos trabalhos apresentam dados de dose efetiva pela ingestão de farinhas, amplamente utilizada como dieta de subsistência em todo o mundo. No presente trabalho, as concentrações de atividades de radionuclídeos naturais e artificiais foram analisadas por espectrometria gama de alta resolução em 38 amostras de farinha (trigo, milho, mandioca, arroz, soja, centeio, aveia e rosca) comumente comercializadas na cidade de São Paulo, Brasil. A partir dessas concentrações foram calculadas as doses efetivas por ingestão para os radionuclídeos considerados. Para os radionuclídeos naturais foram obtidas concentrações de atividade na faixa de 25 Bq.kg-1 a 663 Bq.kg-1 para o 40K, de 0,97 Bq.kg-1 a 4,47 Bq.kg-1 para o 226Ra e de 9,91 Bq.kg-1 a 42,41 Bq.kg-1 para o 232Th. As doses efetivas obtidas estão entre 0,34 μSv.a-1 e 10,56 μSv.a-1 para o 40K, entre 0,67 μSv.a-1 e 18,35 μSv.a-1 para o 226Ra e entre 5,62 μSv.a-1 a 114,02 μSv.a-1 para o 232Th. Os valores de dose efetiva recomendados pela UNSCEAR e IAEA por ingestão de alimentos contendo radionuclídeos naturais são de 140 μSv.a-1 e de 1 mSv.a-1, respectivamente, para os indivíduos do público. Todos os radionuclídeos artificiais estudados, 134Cs, 137Cs, 106Ru, 103Ru, 60Co, 131I e 241Am, apresentaram valores de concentração de atividades abaixo da concentração mínima detectável (CMD), utilizada para o cálculo de dose efetiva. Os valores médios obtidos para 134Cs, 137Cs, 106Ru, 103Ru, 60Co, 131I e 241Am foram de 0,04 μSv.a-1, 0,03 μSv.a-1, 0,13 μSv.a-1, 0,001 μSv.a-1, 0,01 μSv.a-1, 0,05 μSv.a-1 e 0,4 μSv.a-1, respectivamente, para público adulto. Para público infantil os valores médios obtidos para os radionuclídeos artificiais recomendados foram de 0,04 μSv.a-1, 0,03 μSv.a-1, 0,01 μSv.a-1, 0,9 μSv.a-1, 0,1 μSv.a-1, 0,4 μSv.a-1 e 0,6 μSv.a-1, para os radionuclídeos 134Cs, 137Cs, 106Ru, 103Ru, 60Co, 131I e 241Am, respectivamente, inferiores aos valores recomendados pelo CODEX de 1 mSv.a-1. Todas as amostras apresentaram valores de concentração de atividade na faixa dos valores da literatura e inferiores aos limites recomendados não apresentando riscos à saúde a partir da ingestão das farinhas analisadas.

    Palavras-Chave: gamma spectroscopy; gamma detection; radiometric surveys; natural radioactivity; gamma radiation; sample preparation; radiation dose ranges; effective radiation doses; dose limits; gamma dosimetry; radiation detection; limiting values; food; human populations; brazil

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  • IPEN-DOC 27699

    SILVA, ORELIO L. da . Estudo do polipropileno de alta resistência do fundido (HMSPP) irradiado com carbonato de cálcio/nanopartículas de prata para fins de atividade bactericida / Study of high-strength polypropylene from the melt (HMSPP) irradiated with calcium carbonate/silver nanoparticles for purposes of bactericidal activity . 2020. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 80 p. Orientador: Duclerc Fernandes Parra. DOI: 10.11606/D.85.2020.tde-01032021-111908

    Abstract: O carbonato de cálcio (CaCO3) é um mineral importante e abundante em todas as rochas sedimentares utilizadas comercialmente. A casca de ovo de galinha contém 40% de Calcio na forma de CaCO3. Existem vários estudos sobre a influência da adição de carbonato de cálcio nas propriedades físicas e reológicas dos materiais. O objetivo deste trabalho foi avaliar a influência da adição de CaCO3 com nanopartículas de prata (CaCO3/AgNP) em diferentes proporções (0,1 e 0,3%.) nas propriedades de filmes e pellets de HMSPP 12,5 kGy. As cascas lavadas, higienizadas, secas em forno e moídas em um moinho foram caracterizadas para obter o pó de casca de ovo, para uso no presente trabalho. A irradiação em fonte gama foi utilizada para: 1) Preparação de HMSPP, na irradiação de PP a 12,5 kGy; 2) compatibilização CaCO3 / AgNP em HMSPP a 30kGy e 50kGy; 3) Avaliação da estabilidade sob radiação em termos de se as propriedades mecânicas são afetadas ou não na etapa de compatibilidade. Os testes de caracterização realizados para este estudo foram FTIR, DRX, TGA, DSC, bem como teste bactericida. Os resultados indicaram a presença de CaCO3/AgNP nos filmes poliméricos por absorção de FTIR. os picos de prata DRX de 2θ a 38,5° (111) e 44,5° (200) confirmaram a presença de prata no CaCO3. O resultado do DSC indicou que a presença de CaCO3/AgNP nas amostras não alterou a Tm de fusão (155,16°C/CaCO3/Ag 0,1%; 157,52°C/CaCO3/Ag 0,3%) ou a cristalinidade do polímero HMSPP (44,16% e 43,51%), respectivamente, para 0,1 e 0,3%. Além disso, a análise TGA indicou para ambas as amostras de filmes, em diferentes concentrações de CaCO3/AgNP, o mesmo perfil de decomposição, não mostrando influência da radiação ou CaCO3/AgNP na estabilidade térmica dos nanocompósitos.

    Palavras-Chave: eggs; shells; powders; calcium carbonates; silver additions; nanoparticles; strength functions; polypropylene; melt-through; sample preparation; x radiation; x-ray diffraction; scanning electron microscopy; fourier transform spectrometers; thermal gravimetric analysis; dynamical systems; light scattering; infrared spectrometers

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  • IPEN-DOC 27698

    PASSOS, PRISCILA de Q.S. . Modelo tridimensional in vitro de adenocarcinoma prostático humano produzido por levitação magnética / In vitro three-dimensional model of human prostatic adenocarcinoma produced by magnetic levitation . 2020. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 93 p. Orientador: Daniel Perez Vieira. DOI: 10.11606/D.85.2020.tde-01032021-114311

    Abstract: Culturas celulares tradicionais em monocamada nem sempre são suficientes quando aplicadas a ensaios toxicológicos pré-clínicos in vitro, pois podem frequentemente perder as características e funções quando não integradas em um tecido ou órgão. A utilização de PIONs funcionalizadas para a construção de esferoides por levitação magnética é uma ferramenta de baixo custo, de fácil manipulação e biocompatível, permitindo sua associação a linhagens celulares. Neste trabalho, as propriedades biofuncionais de esferoides celulares construídos a partir de células tumorais e nanopartículas magnéticas de óxido de ferro (PIONs) biofuncionalizadas foram estudadas, cujas nanopartículas de óxido de ferro foram sintetizadas por co-precipitação, funcionalizadas com os aminoácidos glicina e poli-L-lisina e então submetidas a caracterização físico-química por MET, DRX, DLS, potencial zeta e FTIR. A partir dessas análises foi possível identificar nanopartículas de magnetita com tamanho ideal e carga eletrostática positiva estável para adsorção às células. Essas nanopartículas também foram submetidas a uma avaliação biológica quanto a adsorção à membrana de células tumorais de próstata (LNCaP), citotoxicidade e formação de esferoides. Foi observada boa adsorção dos PIONs, sem desprendimento das células durante o cultivo celular, não foi observada citotoxicidade das nanopartículas e houve resposta magnética suficiente a fim de permitir a formação dos esferoides quando na presença de um campo magnético. Os esferoides tumorais obtidos a partir da adsorção das nanopartículas foram avaliados estruturalmente por microscopia de fluorescência e analise histológica com resultados satisfatórios para uma estrutura tumoral. Foram também utilizados como sistema-teste na avaliação do potencial tóxico de substâncias farmacológicas e não-farmacológicas de ação conhecida com resultados reprodutíveis. Portanto, o produto final deste trabalho pode ser utilizado em testes posteriores de eficácia de fármacos que visem tratar os tumores prostáticos humanos.

    Palavras-Chave: neoplasms; prostate; iron oxides; nanoparticles; synthesis; glycine; glycylglycine; amino acids; spheroids; tumor cells; cell cultures; adsorption; magnetic fields; scanning electron microscopy; dynamical systems; x-ray diffraction; fourier transform spectrometers; fluorescence; microscopy; histological techniques; comparative evaluations

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  • IPEN-DOC 27697

    SILVA, ISAC A. da . Mecanismos associados ao refino de grão em ligas de alumínio após processamento pela técnica de prensagem em canais equiangulares (PCE) / Grain refining in aluminum alloys after processing by equal channel angular pressing techniques (ECAP) associated mechanisms . 2020. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 117 p. Orientador: Waldemar Alfredo Monteiro. DOI: 10.11606/T.85.2020.tde-01032021-103503

    Abstract: A aplicação final dos materiais metálicos depende das propriedades físicas e mecânicas destes, que podem ser adquiridas por diversos mecanismos aos quais eles são submetidos. Uma propriedade que não raras vezes tem se tornado muito importante e decisiva na utilização dos metais é o tamanho médio de grão do material. Devido ao fato dos materiais metálicos com tamanho de grão muitíssimo pequeno, de ordem submicrométrica, ou nanométrica, apresentarem significativo aumento de resistência mecânica, a sua fabricação tem sido de interesse crescente. Entretanto, a prática industrial convencional para produzir apurado refinamento de grãos em materiais metálicos massivos é o processamento termomecânico, pelo qual, os menores tamanhos de grão obtidos são de ordem micrométrica, mas não submicrométrica ou a nanométrica. São apresentados neste trabalho os mecanismos associados ao refino de grão nas ligas de alumínio AA 1050 e AA 3003 após processamento pela técnica de Prensagem em Canais Equiangulares (PCE), que, por Deformação Plástica Intensa (DPI) bloqueará o movimento das discordâncias do material, conferindo-lhe alta resistência, boa tenacidade e grãos de tamanho nanométrico. Este bloqueio pode também ser obtido por encruamento, solução sólida e precipitação de solutos, porém, os métodos de refinamento de grãos em metais e ligas estão inseridos dentre os mais significativos avanços em metalurgia física.

    Palavras-Chave: aluminium base alloys; transition element alloys; mechanical properties; impact strength; fracture properties; physical metallurgy; thermodynamic activity; grain size; grain refinement; vickers hardness; nanoparticles; nanofluids; deformation; plastic foams; angular distribution; channel; pressing; sample preparation; electric conductivity; optical microscopy; photomicrography; dispersion relations; scanning electron microscopy; performance testing

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  • IPEN-DOC 27696

    AZEVEDO, IZABELA R.C.L. . Utilização da fotodecomposição solar para remoção de oxitetraciclina de águas contaminadas pela atividade pecuária / Use of solar photodecomposition to remove oxytetracycline from water contaminated by livestock . 2020. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 90 p. Orientador: Nilce Ortiz. DOI: 10.11606/D.85.2020.tde-01032021-110303

    Abstract: Desde a sua descoberta em 1953, a oxitetraciclina tornou-se a base antibiótica mais amplamente utilizada e comercializada em áreas rurais devido ao seu alto poder de ação contra as infecções bacterianas que afetam os animais. Nas fazendas, após a metabolização, o antibiótico e seus metabólitos têm sido liberados nas excreções diretamente no solo ou nos recursos hídricos. Estes compostos representam contaminação e comprometimento da qualidade das águas superficiais e subterrâneas. A presença de antibióticos no ambiente tornou-se uma ameaça mundial devido à ocorrência de genes de resistência em bactérias patogênicas, vale lembrar que os métodos convencionais de tratamento de água não removem esses micropoluentes. O objetivo deste estudo foi desenvolver um processo de tratamento e decomposição do antibiótico oxitetraciclina empregando a fotodecomposição solar como fonte de energia renovável e abundante em muitas regiões brasileiras, além de poder ser utilizada em áreas rurais distantes. A otimização dos parâmetros de processo foi obtida por meio do emprego de soluções sintéticas do antibiótico preparadas em laboratório, na qual as concentrações utilizadas foram semelhantes às encontradas em literatura e diferentes proporções mássicas do semicondutor preparado a partir da hidrólise do isopropóxido de titânio e biocarvão. O TiO2 sintetizado foi analisado por microscopia eletrônica de varredura (MEV), difratometria de raios X (DRX) e espectroscopia por dispersão de energia (EDS). As micrografias obtidas no MEV demonstraram que o biocarvão, adicionado durante a hidrólise do isopropóxido de titânio, foi eficiente ao reduzir os aglomerados de dióxido de titânio e promoveu uma melhor adsorção de superfície com o aumento dos poros. O EDS indicou que a amostra possui preponderância para o titânio e em menor proporção para o oxigênio e carbono. O difratograma da estrutura cristalina do TiO2 preparado com adição do biocarvão indicou maior cristalinidade, conteúdo amorfo e possivelmente o maior desenvolvimento da área superficial do TiO2. Os ensaios laboratoriais permitiram uma potencialização dos parâmetros de processo da fotodecomposição, do cálculo cinético e termodinâmico, difusão intrapartícula, além dos cálculos do modelo de Elovich, comprovação da teoria de Langmuir-Hinshelwood e das isotermas. Os resultados que apresentaram as maiores porcentagens de remoção da oxitetraciclina confirmaram que a cinética de pseudo-segunda ordem obteve a maior correspondência, apresentando os maiores valores do coeficiente de Pearson (R2). Os modelos de isoterma avaliados foram os de Langmuir, Freundlich e de Redlich-Peterson, sendo que o modelo de Langmuir apresentou o maior R2. Os cálculos termodinâmicos permitiram identificar que as reações foram endotérmicas, espontâneas e apresentaram também a desordem do sistema. A quantidade ideal de TiO2 microestruturado com biocarvão para o desenvolvimento da fotodecomposição foi de 0,6 g. Com base no trabalho realizado, conclui-se que é possível atingir remoções acima de 90% da oxitetraciclina com o tratamento de água estudado, tanto em condições laboratoriais quanto em área aberta com a utilização da radiação solar natural. O estudo comprova que a fotodecomposição solar é uma tecnologia de tratamento de água eficiente para a remoção do antibiótico com a vantagem de utilizar um recurso sustentável e renovável.

    Palavras-Chave: antibiotics; drugs; veterinary medicine; domestic animals; water treatment; liquid wastes; waste processing; decomposition; solar photochemistry; hydrolysis; crystal structure; titanium oxides; carbon additions; removal; thermodynamics; adsorption isotherms; sample preparation; testing; kinetic equations; dispersion relations; scanning electron microscopy; x-ray diffractometers; spectroscopy; health hazards; environmental protection; brazil

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  • IPEN-DOC 27695

    CARMO, AMANDA P. do . Avaliação da concentração de atividade dos radionuclídeos Ra-226, Ra-228, Pb-210, Po-210 e caracterização química inorgânica das águas minerais da cidade de Amparo, SP / Assessment of 226Ra, 228Ra, 210Pb and 210Po activity concentrations and inorganic chemistry composition of the mineral waters of Amparo, SP . 2020. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 97 p. Orientador: Sandra Regina Damatto. DOI: 10.11606/D.85.2020.tde-01032021-085144

    Abstract: Diversas fontes de água mineral contêm concentrações significativas de radionuclídeos naturais dissolvidos, principalmente, radionuclídeos das séries de decaimento do 238U e 232Th e, essas águas minerais são utilizadas mundialmente devido às suas propriedades terapêuticas, porém possíveis efeitos adversos para a saúde humana podem ocorrer devido à ingestão ou inalação de substâncias radioativas presentes nessas águas, sendo um fator relevante no contexto da Proteção Radiológica. O objetivo deste trabalho foi avaliar as concentrações de atividade dos radionuclídeos 226Ra, 228Ra, 210Pb e 210Po nas fontes de águas minerais da cidade de Amparo e as doses efetivas comprometidas devido ao consumo dessas águas, bem como, caracterizar sua composição química inorgânica. A cidade de Amparo é uma estância hidromineral que pertence ao Circuito das Águas Paulista e tem 11 fontes de água mineral distribuídas pela cidade. As concentrações das atividades do 226Ra, 228Ra e 210Pb foram determinadas pela contagem alfa e beta total, após a separação radioquímica, em um detector proporcional de fluxo gasoso e do 210Po por espectrometria alfa, também após uma separação radioquímica. Os elementos Al, As, Ba, Ca, Cd, Cr, Fe, K, Mg, Mn, Na, Ni, Pb, Zn foram determinados por ICP-OES para a caracterização química inorgânica. As maiores concentrações de atividade determinadas nas fontes de água mineral foram para os radionuclídeos 228Ra e 210Pb na maioria das fontes. Os valores de concentração de atividade variaram para 226Ra de < LID a 39 ± 7 mBq L-1, para 228Ra de < LID a 99,0 ± 0,2 mBq L-1, para 210Pb de < LID a 77 ± 4 mBq L-1 e de 7,0 ± 0,6 mBq L-1 a 102 ± 11 mBq L-1 para o 210Po As maiores doses efetivas comprometidas foram obtidas para o radionuclídeo 228Ra para o público até 15 anos. Entre os elementos químicos analisados, as maiores concentrações foram determinadas para Al, Mn, Ni e Pb.

    Palavras-Chave: drinking water; natural radioactivity; effective radiation doses; isotope ratio; radium 226; radium 228; lead 210; polonium 210; production; alpha particles; beta particles; radioactivity; property values; optical spectrometers; icp mass spectroscopy; comparative evaluations

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  • IPEN-DOC 27694

    DOMINGUES, LUCAS; GATTI, LUCIANA ; AQUINO, AFONSO ; CORREIA, CAIO ; SANCHES, ALBER; GLOOR, EMANUEL; MILLER, JOHN; PETERS, WOUTER; TURNBULL, JOCELYN; BASSO, LUANA; TEJADA, GRACIELA; CASSOL, HENRIQUE; MARANI, LUCIANO. CO measurements as a biomass burning carbon emission tracer at the Amazon Basin. In: VIRTUAL GLOBAL MONITORING ANNUAL CONFERENCE, June 12 - August 7, 2020, Online. Resumo expandido... 2020.

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  • IPEN-DOC 27693

    ABE, ALFREDO ; GIOVEDI, CLAUDIA ; MARTINS, M. . Neutronic screening of potential candidate for accident tolerant fuel. In: . Light Water Reactor Fuel Enrichment beyond the Five Per Cent Limit: Perspectives and Challenges. Resumo expandido... Vienna, Austria: International Atomic Energy Agency, 2020. (IAEA-TECDOC-1918 - Supplementary Files).

    Palavras-Chave: accident-tolerant nuclear fuels; beryllium oxides; cladding; fuel rods; monte carlo method; pwr type reactors; reactivity; stainless steels; uranium dioxide; uranium silicides; zircaloy

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  • IPEN-DOC 27692

    MELLO, S.R.C.; PINHEIRO, A.R.M.; FREIRE, L.O.; ANDRADE, D.A. . Economic evaluation of a mobile nuclear power plant using uranium over 5% enrichment. In: . Light Water Reactor Fuel Enrichment beyond the Five Per Cent Limit: Perspectives and Challenges. Vienna, Austria: International Atomic Energy Agency, 2020. (IAEA-TECDOC-1918 - Supplementary Files).

    Abstract: Moble nuclear power plants seem to be an interesting alternative to provide electric energy to isolated regions because the conventional electric network cannot reach isolated cities, islands, offshore and merchant ships. These reactors would be built over a floating barge that could go to client’s place. This new concept brings up new maintenance and operation issues, especially about autonomy and availability. This study evaluates economic advantages and limitations of using over 5% enrichment fuel on a mobile nuclear power plant (NPP). A supposed mobile NPP is taken as an example and used as calculation basis. An enrichment over 5% could better adjust the maintenance event periods, improving the plant availability, reducing operation costs and improving the competitiveness of this plant type. In addition to the high costs of the enrichment process, the fuel burnup limits and the maintenance activities restrict high levels of fuel enrichment. Therefore, this work suggests a fuel enrichment condition capable to conciliate both cost and performance for a supposed mobile NPP.

    Palavras-Chave: availability; burnup; cost; cost; enrichment; maintenance; nuclear fuels; nuclear power plants; operation; uranium

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  • IPEN-DOC 27691

    ABE, ALFREDO ; CARLUCCIO, THIAGO; PIOVEZAN, PAMELA; GIOVEDI, CLAUDIA; MARTINS, MARCELO R.. Preliminary neutronic assessment of iron based alloy fuel cladding. In: . Light Water Reactor Fuel Enrichment beyond the Five Per Cent Limit: Perspectives and Challenges. Vienna, Austria: International Atomic Energy Agency, 2020. (IAEA-TECDOC-1918 - Supplementary Files).

    Abstract: Nowadays two important nuclear fuel performance requirements have been addressed: high burnup in order to improve fuel cycle economic aspect and accident tolerant fuel to enhance the safety under accident condition. The accident tolerant fuel particularly becomes very important issue after Fukushima Daiichi nuclear accident in 2011. The initiatives of R&D program toward to accident tolerant fuel comprises different countries, organizations and including fuel vendors. The Accident Tolerant Fuel (ATF) can be defined as enhanced fuel which can tolerate loss of active cooling system capability for a considerably longer time period and the fuel/cladding system can be maintained without significant degradation and can also improve the fuel performance during normal operations and transients, as well as design-basis accident (DBA) and beyond design-basis (BDBA) accident. Different materials have been proposed as fuel cladding candidates considering thermo-mechanical properties and lower reaction kinetic with steam and slower hydrogen production, besides that an evaluation of the neutronic aspects for several cladding candidates is important and shall be evaluated. Depending of the outcome of this evaluation, the fuel enrichment level changes to higher than actual level shall be necessary to overcome the neutron absorption penalty. The aim of this work is to perform a preliminary neutronic assessment of fuel cladding based on iron alloy considering a standard PWR fuel rod (fuel pellet and dimension). The main purpose of the assessment is to quantify the penalty due to increase of neutron absorption in the cladding materials and some others fuel parameters are evaluated in order to overcome such penalty. In addition to neutronic assessment, the criticality safety aspects due to increase of fuel enrichment level are briefly presented and discussed.

    Palavras-Chave: absorption; accident-tolerant nuclear fuels; beyond-design-basis accidents; cooling systems; design-basis accidents; enrichment; fuel cycle; fuel pellets; fuel rods; iron alloys; pwr type reactors; radiation accidents; reactor accidents; safety

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  • IPEN-DOC 27690

    PERINI, ALINE A. ; JAROSZEWSKI, CASSIANE R. ; MAGALHAES, ADRIANA B.V.B. ; FERREIRA, LETICIA H. ; RAMALHO, IRAIDES ; FREITAS, ANDERSON Z. . Entrepreneurial university and Its engagement in the triple helix system: roadmapping to leading innovation on early stage: the technology transfer office whole. In: ABU-TAIR, ABID (Ed.); LAHRECH, ABDELMOUNAIM (Ed.); AL MARRI, KHALID (Ed.); ABU-HIJLEH, BASSAM (Ed.). Proceedings of the II International Triple Helix Summit. Cham, Switzerland: Springer Nature Switzerland AG, 2020. p. 21-33, (Lecture Notes in Civil Engineering, 43). DOI: 10.1007/978-3-030-23898-8_3

    Abstract: This paper presents as main contribution the standardization of complex areas in the development and empirical demonstration of a managerial roadmap tool applied to the TTO (Technological Transfer Office) scenario, which primary role is to anticipate trends in technological and innovative skills at the level of firm to meet the demands from smart cities solutions, among University engagement and Industry. Implementing roadmapping on early stage in innovation provides convergence in key-technologies at the Nuclear an Energy Research Institute, addressing structural, regional, institutional role in Intellectual Property and complementarities to development market front-to-end through chains in health, environment, food, agriculture, energy, chemistry, education, entertainment and arts in the context of the knowledge economy.

    Palavras-Chave: convergence; market; technology transfer; educational facilities

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  • IPEN-DOC 27689

    MUNITA, CASIMIRO S. . Las fronteras del infierno: consecuencias del impacto de un artefacto nuclear sobre la Plaza de Armas de Santiago, Chile. 2020. 84 p.

    Palavras-Chave: radioactive materials; nuclear weapons; nuclear energy; nuclear explosions; chile

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  • IPEN-DOC 27688

    CIONE, FRANCISCO C. ; BETINI, EVANDRO G. ; BOATO, MARCOS G.; SOUZA, ARMANDO C. de; ROSSI, JESUALDO L. . Experimental analyses defining mechanical characteristics of obtained W-Cu-Ni composite applied as a radiation shielding material. International Review of Mechanical Engineering (IREME), v. 14, n. 3, p. 169-176, 2020. DOI: 10.15866/ireme.v14i3.17084

    Abstract: This work aims to obtain a new composite material of system W-Cu-Ni using the powder metallurgy usable as material for strongly shielding of the gamma radiation as an environmental friendly alternative to lead. Tungsten (W) is the main shielding element in this composite. The main reason to use CuNi in this compound is the miscibility of both metals and their low fusion temperature, allowing liquid phase sintering. The tungsten has high density (19.25 gcm-3), high melting point (3,422 °C) and is presented as matrix of the composite. In order to meet the need for sintering with low temperatures, the liquid phase sintering technique has been used. For sintering temperature optimization, the particles of the metal powders have been homogenized in shape and size. In order to reduce the average particles size, a ball mill has been used for 48 hours. After grinding, the particle size analysis has showed that the mean particle size in WCuNi composition has been 8.6 μm. The powder mixture has been compacted in isostatic press at 200 MPa pressure. The samples have been sintered between 1,100 °C and 1,400 °C at 1100 mbar pressure with a flow of protective atmosphere (Ar2) for 180 min for each temperature. The formation of the isomorphic system CuNi is responsible for giving the mechanical characteristic of solid to the composite WCuNi. The result of micro hardness test shows a maximum of 331 HV and average of 276 HV. Optical and electronic microscopy (SEM) with EDS have been undertaken in order to characterize the samples. The classical scientific method of experimentations with gamma radiation of the cobalt-60 source by attenuation of the energies has been employed to study these effects on the samples. The results shows that composite has more shielding efficient than lead and is safety for life and environment when compared with lead toxity.

    Palavras-Chave: mechanical properties; composite materials; powder metallurgy; tungsten; shielding materials; attenuation; gamma radiation

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  • IPEN-DOC 27687

    LIMA, CAROLINE S.A. de; VARCA, GUSTAVO H.C. ; COSTA, SIRLENE M. da; FERRAZ, HUMBERTO G.; SANTOS, ANA C. da S.; LOPES, PATRICIA S.; COSTA, SILGIA A. da. Development of natural polymeric microcapsules for antimicrobial drug delivery: triclosan loaded chitosan and alginate-based microcapsules. Drug Development and Industrial Pharmacy, v. 46, n. 9, p. 1477-1486, 2020. DOI: 10.1080/03639045.2020.1809445

    Abstract: The goal of this work was the development of natural polymeric microcapsules for antimicrobial drug delivery – triclosan loaded alginate and chitosan-based microcapsules for potential coating applications in substrates such as textiles or plastics. Microcapsules containing 2.5% (w/w) or 3% (w/w) triclosan in both core and matrix were synthesized and evaluated by Fourier-transform infrared spectroscopy, scanning electron microscopy, confocal microscopy, differential scanning calorimetry, thermogravimetry, and antimicrobial activity. The microcapsules produced featured spherical and mostly irregularly-shaped surfaces composed by an alginate core in a chitosan outer matrix, as revealed by confocal microscopy, and antimicrobial activity against S. aureus and E. coli with inhibition halos up to 60 mm and 25 mm respectively, granted by a triclosan loading of 61.66%. The thermal analysis suggested that the polymers protected the active substance from temperature-induced degradation. In conclusion, these microcapsules may be applied toward antimicrobial functionalization of plastics, textiles and other materials.

    Palavras-Chave: polysaccharides; oligosaccharides; antimicrobial agents; drugs; antiseptics; sodium; alginates; polymers

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  • IPEN-DOC 27686

    ARAUJO, JOAO V. de S. ; SILVA, REJANE M.P. da ; MILAGRE, MARIANA X. ; MACHADO, CARULINE de S.C. ; COSTA, ISOLDA . Mecanismo de evolução de hidrogênio durante a corrosão da liga 2198-T8 em meio contendo cloreto: uma abordagem eletroquímica / On the hydrogen evolution mechanism during corrosion of the 2198-T8 alloy in chloride solution: an electrochemical approach. Química Nova, v. 43, n. 8, p. 1058-1065, 2020. DOI: 10.21577/0100-4042.20170598

    Abstract: Corrosion is still one of the most serious and frequent problems in industries. The phenomena involved in the corrosion mechanism of Al-alloys may be explained by formation of galvanic cells between the metal matrix and heterogeneities, such as precipitates, intermetallic phases leading to potential differences and electrochemical reactions. In the cathodic sites, the main reactions are oxygen reduction reaction, in aerated neutral environments, and hydrogen evolution in acid media. This last type of reaction might also occur in neutral solutions inside pits (anodic region). In this study, the mechanism of hydrogen evolution during corrosion of the 2198-T8 Al-Cu-Li alloy exposed in a chloride solution was investigated. The mechanism was related to the presence of T1 phase (Al2CuLi), which is the main strengthening phase in this material. This phase is highly active and, when exposed to corrosive media, leads to severe localized corrosion (SLC). One of the main characteristics related to SLC is hydrogen gas evolution which was confirmed by gel visualization. In this study, the hydrogen evolution mechanism inside the SLC sites was studied by scanning electrochemical microscopy (SECM).

    Palavras-Chave: corrosion; corrosion resistant alloys; aluminium alloys; copper alloys; lithium alloys; hydrogen production; electrochemistry

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  • IPEN-DOC 27685

    ZEZELL, DENISE M. ; ANA, PATRICIA A. da; BENETTI, CAROLINA; PEREIRA, DAISA de L. . Lasers e LEDs: mecanismos de interações com os tecidos biológicos. In: GARCIA, VALDIR G. (Ed.); THEODORO, LETICIA H. (Ed.). Lasers na Odontologia: Uma Visão Clínica Baseada em Evidências Científicas. São Paulo, SP: Santos Publicações, 2021. p. 9-15, cap. 2.

    Palavras-Chave: dentistry; lasers; light emitting diodes; animal tissues

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  • IPEN-DOC 27684

    ZEZELL, DENISE M. ; PEREIRA, DAISA de L. ; BENETTI, CAROLINA. Princípios da Física aplicada ao uso dos lasers e LED. In: GARCIA, VALDIR G. (Ed.); THEODORO, LETICIA H. (Ed.). Lasers na Odontologia: Uma Visão Clínica Baseada em Evidências Científicas. São Paulo, SP: Santos Publicações, 2021. p. 1-8, cap. 1.

    Palavras-Chave: dentistry; lasers; light emitting diodes; physics; electromagnetism

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  • IPEN-DOC 27683

    RICARDO, LUIZ F.F.; TOPPER, TIMOTHY H.; RICARDO, LUIZ C.H. ; MIRANDA, CARLOS A.J. . Crack propagation in the threshold stress intensity region a short review. In: CORREIA, JOSE A.F.O. (Ed.); JESUS, ABILIO M.P. de (Ed.); FERNANDES, ANTONIO A. (Ed.); CALÇADA, RUI (Ed.). Mechanical Fatigue of Metals. Cham, Switzerland: Springer Nature Switzerland, 2019. p. 175-180, cap. 23. (Structural Integrity, 7). DOI: 10.1007/978-3-030-13980-3_23

    Abstract: This work presents a short review of fatigue crack propagation with emphasis on the parameters that influence the threshold stress intensity, ΔKth. This threshold value is dependent on such variables as the material itself, the test conditions, the R-ratio, the environment and crack closure. The crack geometry effects are discussed as well as some crack closure models. A discussion of other parameters that influence the threshold stress intensity regime including short crack thresholds and their respective models and their application will be the subject of a near-future review.

    Palavras-Chave: crack propagation; deformation; mechanical properties; fatigue; design; stress intensity factors; closures

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  • IPEN-DOC 27682

    ANTIORIO, DAIANE D.; BONATTI, FERNANDA A. da S.; BONATTI, JOSE A.; IROCHIMA, FRANCISCO; ROGERO, JOSE R. ; GLEISON, LEONARDO; SANTOS, MICHELE U. dos; VIEIRA, SILVERLEI S.. Glaucoma: a vida num tubo. São Paulo, SP: Ornitorrinco, 2020. 200 p.

    Palavras-Chave: sense organs diseases; eyes; ophthalmology; vision; diagnostic techniques; therapy

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  • IPEN-DOC 27681

    REDÍGOLO, MARCELO ; COSTA, ISOLDA ; VEGA, OSCAR . Cadernos de Ciência da Conservação: Tintas Brasileiras. São Paulo, SP: Scortecci, 2020. 110 p. v. 1.

    Notas de conteúdo: também disponível em versão impressa

    Palavras-Chave: cultural objects; preservation; inks; chemical composition; gas chromatography; mass spectroscopy; fourier transformation; scanning electron microscopy; x-ray fluorescence analysis

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  • IPEN-DOC 27680

    LI, FANG-YEN; WANG, SHENG-FAN; BERNARDES, EMERSON S. ; LIU, FU-TONG. Galectins in host defense against microbial infections. In: HSIEH, SHIE-LIANG (Ed.). Lectin in Host Defense Against Microbial Infections. Singapore: Springer Nature Singapore, 2020. p. 141-167, cap. 6. (Advances in Experimental Medicine and Biology, 1204). DOI: 10.1007/978-981-15-1580-4_6

    Abstract: Galectins are differentially expressed in a variety of cell types, including immune cells, and characterized by the affinity for β-galactoside–containing glycans. There are fifteen galectin members in mammals. Galectins are primarily located intracellularly, but can be secreted outside the cells. They exhibit pivotal roles during microbial infection, such as pathogen recognition and innate and adaptive immunity, and this review aims to discuss the functions of endogenous galectins during infection by four main types of microbes (bacteria, fungi, viruses, and parasites). Extracellular galectins are known to exert a bacteriostatic effect on some bacteria via association with bacterial glycans, whereas cytosolic galectins are recognized to control antibacterial autophagy by binding to luminal host glycans of ruptured endo-lysosomes. With regard to fungal infections, most studies deal with galectin-3. Galectin-3 modulates fungal burdens, the adaptive immune responses, and mortality in fungi-infected mice, which has been shown to be associated with its ability to manipulate fungicidal functions in neutrophils and cytokine expression in dendritic cells. Some viral infections, such as human immunodeficiency virus (HIV) and influenza virus infections, can be regulated by galectin-1 and -3, and they affect various aspects of viral infections, including viral binding, replication, budding, transmission, and infection-associated inflammation. Functions of galectins during a number of different parasitic infections have been identified in studies using galectin-knockout mice. Different parasitic infections have consistently demonstrated a role of galectins in tuning T helper immune responses in infected hosts.

    Palavras-Chave: parasites; viruses; bacteria; fungi; immunity; immune reactions; galactose

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  • IPEN-DOC 27679

    SACHDEVA, MAHIMA; SMITH, RICARDO B. ; SACHDEVA, ASTHA. Moving ahead towards sustainable development-AHWR, an amicable approach for nuclear reactors. In: JAIN, VINOD K. (Ed.); RATTAN, SUNITA (Ed.); VERMA, ABHISHEK (Ed.). Recent Trends in Materials and Devices. Singapore: Springer Nature Singapore, 2020. p. 203-210, cap. 21. (Springer Proceedings in Physics, 256). DOI: 10.1007/978-981-15-8625-5_21

    Abstract: With a constant urge of digging the unraveled, India has come far ahead in taking an evolutionary step in the field of nuclear science. There has been a recent breakthrough in nuclear reactor advancements. India is using advanced heavy water reactors which function on thorium as one of its fuel components. It can be used in conjunction with plutonium or low enriched uranium. This has been a massive lead as it produces energy at commercial levels and leaves lesser residual actinides having long half-life and inert thorium oxide. This has optimized the energy production rate up to 50% with respect to its production of burnt fuels. This research focuses on bringing an insight on recent advancements in terms of researches and scientific projects that are being conducted in India and how its result would ascent with the current sustainability models such as “Green Chemistry”, a program developed two decades ago in United States and England which defines its requirement for efficient transformation of reagents in obtaining desired results. This revolutionary uplift in nuclear science must reach global acceptance and execution. Considering the ample resources nature earth has bestowed us with, Brazil has remained away from the thorium fueled reactor project studied 50 years ago and there is no light put towards any future research prospects either. Being the second largest reserve of thorium on the entire planet, AHWR can become a mass advantage if explored and taken into deeper accounts.

    Palavras-Chave: thorium; heavy water; reactor safety; radioactive wastes; enriched uranium

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  • IPEN-DOC 27678

    CERAVOLO, FLÁVIO E. ; ROCHA, MARCELO da S. ; ANDRADE, DELVONEI . CFD simulation of isothermal upward two-phase flow in a vertical tube of annular section. In: BRAZILIAN CONGRESS OF THERMAL SCIENCES AND ENGINEERING, 18th, November 16-20, 2020, Online. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2020.

    Abstract: This work presents a simulation of a vertical, upward, isothermal two-phase flow of air bubbles and water in an annular channel applying a Computational Fluid Dynamics (CFD) code. The simulation considers an Eulerian frame, with a two-fluid model, specific correlations for turbulence modeling, and bubble-induced turbulence effects. The work intends to assess the accuracy of the code by comparing the simulation results with experimental data obtained from the literature. The annular channel has an equivalent hydraulic diameter of 19.1 mm, where the outer pipe has an internal diameter of 38.1 mm, the inner cylinder 19.1 mm, and a total length of 1900 mm. The void fraction distribution, taken radially to the flow section, is the main parameter analyzed besides interfacial area concentration (IAC), interfacial gas velocity, and bubble diameters distribution. The numerical models applied in this work demonstrate satisfactory agreement with the experimental data but indicate the need for further improvement in the phase interaction models.

    Palavras-Chave: isothermal processes; bubbles; two-phase flow; annular space; fluid flow; fluid mechanics; computer codes

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  • IPEN-DOC 27677

    FREITAS, L.F. ; CRUZ, C.C. da ; BATISTA, J.G. ; VARCA, G.H. ; LUGAO, A.B. ; MATHOR, M.B. . Hybrid gold-protein nanoparticles as radiosensitizers. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Gold nanoparticles present unique optical properties which are dependent upon size and morphology, and consist on a differential interaction with radiation compared to the bulk material. Those nanoparticles can be modified in order to adjust their bioavailability and tissue-targeting, and one of the means to do so is by adsorbing one or more types of proteins onto their surface. Gamma radiation can be helpful in this regard, since it promotes intra- and intermolecular crosslinks in proteins and enables their adsorption onto the metallic nanoparticles’ surfaces. Here we present the results obtained for hybrid gold-protein nanoparticles as radiosensitizers. The nanoparticles were synthesized radiolytically by mixing 5 mmol L-1 NaAuCl4 with 1 mg mL-1 bovine serum albumin (BSA) or papain in the presence of 0.1 mol L-1 tert-butanol and 20% ethanol. The solutions were irradiated with 10 kGy in a multipurpose gamma irradiator (60Co source, 5 kGy per hour) for the radiolytic synthesis of the nanoparticles, and then the resulting red suspension was stored until use. 10^4 cells (MDA-MB-231 line) were seeded in 96-well plates and incubated with a 2:1 mixture of DMEM medium and nanoparticles suspension for 12 hours. Then, the wells were washed with sterile phosphate buffered saline, and fresh DMEM medium was added prior to irradiation in a gamma cell (60Co source, 0.6 kGy per hour) with 10, 30 and 50 Gy. 48 hours later, the cell viability was assessed by MTS assay. The results indicate that the radiation alone slightly stimulated the proliferation of the tumor cells, but this effect was more evident in the presence of gold-papain nanoparticles. The ablative effect due to radiosensitization was observed with 30 and 50 Gy for the cells incubated with gold-BSA nanoparticles, and 10 and 30 Gy for the cells incubated with gold-papain nanoparticles. This difference might be due to a more effective internalization or surface-attachment of nanoparticles when they are coated with papain, and one evidence for this assumption is the fact that the cell culture becomes red after the incubation with gold-papain nanoparticles. Therefore, protein-coated nanoparticles might be effective as radiosensitizers, depending on the coating and dose of radiation.

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  • IPEN-DOC 27676

    RIBEIRO, M.S. ; YOSHIMURA, T.M. ; TOLEDO, V.H.; HADDAD, P.S.. A novel superparamagnetic nanoplatform assisted by light against nonlocal bacterial infections. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: The increasing resistance to antimicrobials worldwide requires new strategies to fight infectious diseases. Antimicrobial photodynamic therapy (APDT) emerges in this scenario as a promising approach. APDT is a light-based therapy combined to a photosensitizer drug and oxygen that kills microorganisms via oxidative stress. Due to its mechanism of action, i.e., generalized oxidation of all cell structures, bacterial resistance to APDT is very improbable. Currently, however, APDT is limited to local treatments. Thus, a platform to deliver the photosensitizer drug in internal organs is urgently necessary. Superparamagnetic iron oxide nanoparticles (SPIONs) can be easily directed to target sites using an external magnetic field, which made them excellent drug delivery systems. In addition, their large surface to volume ratio allows the functionalization of therapeutic molecules on their surface. In this work, we synthesized and characterized SPIONs covered by methylene blue (MB)-entrapped silica (SPIONs-silica-MB) and investigated their potential combined to APDT to kill Escherichia coli, the most common bacteria found in urinary tract infections. We synthesized SPIONs by the co-precipitation of iron (II) and (III) chlorides in the presence of a weak base and covered them with a double layer of silica leading to the hybrid material magnetite-silica-MB. SPIONS were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, and magnetic measurements. Kinetics of MB release and production of singlet oxygen from SPION-silica-MB were also obtained. The average crystallite size of magnetite was found to be 14 nm. Infrared spectra showed characteristic bands of iron-oxygen and others associated with silicate groups. At room temperature, the nanoplatform presented magnetic behavior due to the magnetite core. MB release increased exponentially until 18 h, when it reached a plateau. Singlet oxygen was spontaneously released from SPIONs-silica-MB. To verify the photodynamic activity of SPIONs-silica-MB on bacterial cells, 1x10^7 colony forming units of E. coli were suspended in SPIONs-silica-MB PBS solution (50 microM of MB) and were irradiated using a red LED (625 ± 20 nm) of 235 mW over an orbital shaker to prevent precipitation during 5, 10, 15 and 20 min at three different MB release times: 6, 12 and 22 h. Proper controls were established and showed no killing. In contrast, SPIONs-silica-MB-mediated APDT promoted bacteria inactivation depending on both the time of MB release and irradiation time. Our results show that bacteria are completely eradicated following 22 h of MB release and 20 min of irradiation. These findings motivate the use of SPIONs-silica-MB to mediate APDT against nonlocal infectious diseases.

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  • IPEN-DOC 27675

    ZEN, H.A. ; LUGAO, A.B. . Effect of molecular sieve incorporation into fluoroelastomer on the mechanical properties. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: The nanoparticle incorporation improves mechanical and thermal properties, and also improve gas barrier property in a polymeric matrix. This incorporation can be facilitated by elastomer solubility, which permits a homogeneous distribution of the nancoparticle. In this work molecular sieve with 3A was incorporated into fluoroelastomer matrix at 0.5, 1, 2 and 5% weight. In a Banbury equipment was carried the nanoparticle and fluoroelastomer, in order to obtain nanocomposites. After that was performed the vulcanization process to obtain films with 0.5mm of thickness. The films were characterized by mechanical tests and swelling degree to determine the modification on mechanical properties of the fluoroelastomer matrix. The results showed an increase in the stiffness and in the tension at break values although the swelling values didn’t suffer drastic changes.

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  • IPEN-DOC 27674

    MELLO-CASTANHO, S. ; PARRA SILVA, J. ; YAMAGATA, C. . Surface activation of Palygoskite nanotubes for wastewater treatment. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: The ion exchange / sorption method is one of the most popular and attractive methods used to treat effluents containing heavy metals. The peculiar chemical characteristics, associated to the nanoscale of the structural network with the presence of natural nanotubes, as is the case of paligorsquita, makes it a potential candidate to meet the requirements of high sensitivity and selectivity in the extraction of heavy ions in wastewater. In the process of developing materials with sorption properties for the incorporation and subsequent immobilization of heavy ions in the same matrix, the most important steps are the generation of active sites, together with increased specific surface area. The parameters and conditions for the activation process of the natural Palygorskite nanotubes aiming to the sorption and immobilization of nickel ions present in wastewater from industrial activities were determined. Paligoskite from Piaui State Brazil, was used as raw material. The characterized and the acid activation process were selected for this development. Subsequent heat treatments were carefully selected conditions by thermal analysis (ATD/TG) to avoid collapse of the nanotubes. The results obtained of maximum sorption capacity for nickel on activated natural nanotubes were very promising. Structural folding observed in the clay may surely important contribution for the heavy metal immobilization processes. Finally, the optimization of the acid activation process is fundamental to improve the sorption’s capacities in solid-liquid medium for extraction specifics metals by activated natural nanotubes.

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  • IPEN-DOC 27673

    KLUMPP, R.E. ; VIVEIROS, B.G. ; SILVA, R.M. ; MAGNANI, M.; ANTUNES, R.A.; COSTA, I. . Corrosion protection for Aluminum surfaces of use in the aircraft industry by hybrid Sol-Gel/Cerium nanocomposite coating. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Localized corrosion is a threat for aluminum alloys structures used in the aircraft industry. Toxic and carcinogenic surface pre-treatments based on hexavalent chromium have been widely used due to its highly effective corrosion protection properties. However, since it has been increasingly banished from use, there is great interest in the development of surface pre-treatments by clean technology to replace those that generate toxic residues. In this work, a novel eco-friendly surface treatment based on an hybrid sol-gel/Cerium nanocomposite coating was proposed with the great advantage over other treatments proposed carried out in literature that consists in one single step process. The effect of this newly developed treatment on the morphology, chemical composition and corrosion resistance of an Alclad alloy (AA1230) surface used in the aeronautic sector was evaluated. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) analyzed surface morphology, whereas corrosion resistance was studied by electrochemical techniques and Neutral Salt-Spray Test (NSST). Chemical composition of the surface after treatment was analysed by X-ray photon electron spectroscopy (XPS). The results showed high corrosion resistance of the treated surface comparable to that provided by chromated surfaces. Besides, high adhesion of the treated surface to a varnish, indicated that it is a viable alternative for replacement of chromate layers obtained from solutions with hexavalent chromium ions. Advantages of the treatment are environmentally friendly, effective corrosion protection and low costs.

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  • IPEN-DOC 27672

    CARDOSO, E.C. ; PARRA, D.F. ; SCAGLIUSI, S.R. ; KOMATSU, L.G. ; LUGAO, A.B. . Ionizing radiation compatibilization in bio-based blends from PBAT/PLA reinforced with bio-eggshell. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Plastics global annual production exceeds 300 million tons and 99% is originated from oil or fossil combustibles. The amount of plastics wastes utilized exceeds the amount into landfills, prejudicing effectively the environment. As an alternative, they are being slowly replaced by bioplastics, as PLA (poly-lactic acid) and PBAT (butylene adipate co-terephthalate). Food and dairy industries produce annually huge amounts of avian eggshells residues and their disposition presents a serious environmental risk. Bio-load from avian eggshells as polymers reinforcement is based in their higher benefits as resistance and rigidity besides being a friendly environmental material, degradable and renewable. PLA and PBAT are thermoplastics capable to be processed by conventional methods: nevertheless, due to their high interfacial tension, it is required the use of compatibilizers. In this work, additives and heat generally used as compatibilizers were replaced by e-beam radiation, at 150 kGy dose. PBAT/PLA blends were prepared at the weight ratio of 82 / 18 and 5.0 phr of PLA 150 kGy e-beam radiated, at 2.5, 5.0 and 10.0 phr of bio-eggshells. Samples were homogeneized in a co-rotating twin-screw extruder and further characterized for: DSC, TGA, FTIR, XRD and Mechanical essays.

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  • IPEN-DOC 27671

    SCAGLIUSI, S.R. ; CARDOSO, E.C. ; LUGAO, A.B. . The degrading effects of the radiation on the properties of butyl rubber compounds. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Polymeric materials (plastics and rubber) have been contributing in a continuously and raising way for the generation of litter and industrial wastes discarded in landfills. Gamma ionizing radiation has capacity for changing structure and properties of polymeric materials and can be applied to almost all types of polymers; irradiation is an expectation for problem-solving of rubber wastes management that can be utilized as raw-materials or chemical additives. butyl rubber has excellent mechanical properties and oxidation resistance, as well as low gas and water vapor permeability. At the initial stage of irradiation the degradation of butyl rubber occurs predominantly via random chain-scission This work aims to the introduction of a new recovery technique for butyl rubber, by using processing via gamma-rays followed by shear. 5 kGy, 15 kGy, 25 kGy, 50 kGy, 100 KGy, 150 kGy and 200 KGy doses were used, in order to study the feasibility of butyl rubber for recycling. Doses within 5 to 25 kGy applied to butyl rubber and pointed toward a less degraded material.

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  • IPEN-DOC 27670

    CAVALCANTE, A.K. ; BATISTA, J.G. ; MAZIERO, J.d. ; FERNANDES, B.V.; VIVEIROS, W.; ROGERO, S.O. ; ROGERO, J.R. ; LUGAO, A.B. . In vitro and In vivo toxicity of Gold nanoparticles synthesized and stabilized with phytochemicals. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Gold nanoparticles (AuNPs) are among the most widely studied metal nanoparticles for biomedical applications. AuNPs can be synthesized by chemical reduction. Several methods for this type of synthesis are described in the literature, one of them is the Turkevich method, which uses sodium citrate (CITR) as a reducing agent. Other methods were developed based on the use of solvent systems during nanoparticle production. Although they are efficient production methods, they are environmentally unviable. In order to address this issue, metabolites present in various plant extracts have been explored for the preparation of different AuNPs. Green nanotechnology is the nanotechnology aspect that aims to develop protocols to generate sustainable products and production processes, in order to minimize the use of toxic compounds. In this study, the phytochemicals chosen as reducing agents and stabilizers for AuNPs synthesis were mangiferin (MGF) and resveratrol (RESV). Due to their ability to interact with biological systems, along with various applications of AuNPs, their toxicity has become one of the most important concerns. Due to the increased production and use of AuNPs, their risk of reaching different environmental compartments and becoming available increases the importance of determining toxicity in various species of biological interest, such as microcrustaceans and fish. Zebrafish is an important animal model used in the areas of developmental biology, genetics, biomedicine, nanotoxicology and is also used in ecotoxicological assays. The aim of the study is to evaluate the toxicity level of MGF (MGF-AuNPs) and RESV (RESV-AuNPs) reduced and stabilized AuNPs in vitro and in vivo by comparing them with the classical AuNPs synthesis method described by Turkvich (CITR-AuNPs). The study has two strands, one of which is to evaluate the level of nanomaterial toxicity using the zebrafish animal model as a preclinical study, and the other to evaluate the level of nanomaterial toxicity using the zebrafish animal model as a study of environmental toxicity. Cytotoxicity assay according to ISO 10993-5, Zebrafish FET TEST according to OECD 236 and Microinjection Assay in Zebrafish embryos. Green nanotechnology has proven to be a valuable tool in the synthesis of AuNPs for toxicity, not requiring the use of solvents and potentially toxic substances. The toxicity of AuNPs varied according to the assay. In the cytotoxicity assay, IC50 was obtained from CITR-AuNPs, whose IC50 was about 72%, which corresponds to the Au concentration of 74.16 µg.mL-1. In FET, RESV-AuNPs caused delays in the hatching process of zebrafish embryos, and it was the only sample that could obtain the LC50 (4.41%, corresponding to the Au concentration of 6,57 µg.mL -1). In the assay in which AuNPs were microinjected into embryos, the concentration causing toxic effect was not found in 50% of the organisms.

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  • IPEN-DOC 27669

    BARTOLOMEI, S.S.; BARTOLOMEI, M.R. ; SILVA, F.A.; OLIVEIRA, A.A.. Use of biodegradable oils as an alternative cooling in quenching treatment. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Ferrous alloys stand out for their use in various branches of the mechanical industry, as they encompass a series of mechanical properties that directly influence their application. For their implementation to be successful, they must have a suitable microstructure, which provides steel with sufficient mechanical characteristics so that it can withstand various types of efforts resulting from its implementation. Heat treatments are responsible for developing this microstructure in a controlled manner, through a set of heating and cooling operations with controlled conditions of temperature, time, atmosphere and cooling speed, in order to change their properties or give them some features. One of the most conventional treatments used worldwide to impart mechanical resistance to steels is the quenching treatment, which consists of heating the metal to austenitization temperature, kept at the same temperature for a certain time and after cooling it rapidly in a liquid medium. great efficiency in the extraction of heat, which can be water, saline solutions, polymeric solutions and oils, in order to form a new microstructure, harder but more fragile than its initial state, called martensite, which after tempering, has its stress-free internal structure, increasing its toughness. The most common cooling medium of the last decades is mineral oil, which due to its viscosity, has excellent capacity to extract heat, but it is a great villain when it comes to environmental issues, an example of this is the increase of water contamination. underground, where mineral oils are the most abundant contaminants present in the analyzed samples of these sources. Due to these and other environmental problems, studies have been developed to obtain an alternative cooling medium as effective as mineral oil, but which has less environmental impact. One solution to this problem is to use compound oils from renewable and biodegradable sources such as vegetable oils. Therefore, this work studies the effects of tempering on SAE 1045 carbon steel and AISI 420 martensitic stainless steel, using biodegradable soy and castor oil as cooling medium. For this, the viscosity of the oils was measured at room temperature and heated to 70 °C, temperatures at which tempering treatments were performed on 10 x 20 x 20mm rectangular section specimens. The specimens were cut, embedded and polished to be characterized by optical micrograph and Vickers microhardness. The results showed that biodegradable oils have excellent stability to bath temperature variation and can be applied over large temperature ranges due to their high flash points. Regarding the hardness and microstructure formed inside the specimen, the vegetable oils were also efficient, presenting values very similar to mineral oil, being soy oil more efficient than castor oil due to its low viscosity influencing hardness of the pieces and also in the formation of martensite. Biodegradable oils have proven to be an alternative.

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  • IPEN-DOC 27668

    MOURA, E.A. ; SANTOS, B.S. ; OLIVEIRA, R.R. ; RODRIGUES, R.C.. Synergistic effect of polylactic acid(PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend and cellulose nanowhiskers for sustainable packaging applications. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Conventional food packaging is in general, not recyclable, based on practically undegradable petroleum-derived polymers, and consequently not selectively collected. Concerns over their environmental impact and sustainability issues posed by their production and disposal and trends have increased interest and driven the effort to generate biobased and biodegradable packaging to replace or complement the conventional ones. The aims of this work are to investigate the development of biocomposite films composed of biodegradable polylactic acid(PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend and cellulose nanowhiskers extracted from agro-waste and evaluate their potential use in sustainable food packaging application. Biocomposite films based on biodegradable PLA/PBAT blend containing 1-2 wt. % of cellulose nanowhiskers extracted from agro-waste were prepared by melt extrusion, using a twin-screw extruder machine and blown extrusion process. To evaluate the potential use in food packaging applications, the cellulose nanowhiskers' content on the morphological, mechanical and thermal properties of the as obtained biocomposite films has been assessed. In addition, cellulose nanowhiskers were characterized by TEM, DLS, XRD, and TG. The results showed that cellulose nanowhiskers addition leads to an important increase in thermal degradation temperature, melting enthalpy and tensile properties of biocomposite films. The increases in the melting enthalpy can be attributed to the increase in the crystallinity of PBAT/PLA biocomposite as a result of cellulose nanowhiskers' addition. Morphology and thermal tests were related to the properties of the films and confirmed that cellulose nanowhiskers were homogeneously dispersed into the matrix. Based on the results, this research demonstrated that the use of biodegradable polymer blend and cellulose nanowhiskers extracted from agro-waste represents an interesting alternative for the production of flexible biocomposite films for sustainable food packaging applications and for the development of eco-friendly technologies.

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  • IPEN-DOC 27667

    BARTOLOMEI, M.R. ; ISHIKAWA, O. ; BARTOLOMEI, S.S.; MOURA, E.M. . UV Barrier influence according to the amount of TiO2 in PBAT biodegradable flexible film. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Manufacturing and consumption of polymeric products and packaging continues to grow despite concerns about environmental contamination due to improper post-consumer disposal, causing polymeric waste to emerge in increasingly remote places, polluting seas and soil, affecting flora, fauna and human health. Among these wastes are flexible food packaging. One of the alternatives to reduce this problem is the use of biodegradable materials, such as poly (butylene adipate-terephthalate) (PBAT), but the properties of this material do not meet all the needs of a food packaging, focus of this work. Additives and / or fillers must be added to improve the properties of this polymer, such as mechanical, thermal and barrier properties. One of the important features of a food packaging is the UV light barrier, as many products have shortened shelf life due to interaction with light. This work studies the effect of the addition of titanium dioxide (TiO2) particles to improve UV light barrier in biodegradable flexible PBAT films, with clay addition to improve mechanical properties. The films were obtained by melt processing so that the application is industrially and economically viable. For this, known amounts of TiO2 (0.1, 0.2 and 0.3 wt%) were added in a poly (vinyl alcohol) (PVA) solution, along with 0.5 wt% organophilized light green clay. This mixture was sonicated, poured onto PBAT pellets and oven dried. Then, the particle coated pellets were processed in a twin screw extruder, cooled and pelleted. Then the flexible film was produced in a flat die single screw extruder, thus producing 4 nanocomposites (PBAT + 0.5wt% Clay; PBAT + 0.5wt% Clay + 0.1wt% TiO2; PBAT + 0.5wt% Clay + 0.2wt% TiO2; PBAT + 0.5wt% Clay + 0.3wt% TiO2). The results of X Rays Diffraction (XRD), Scanning Electron Microscopy (SEM) and tensile test showed that the clay was exfoliated in the polymer matrix, allowing improvements in the mechanical strength and elongation of the films. UV-vis absorption assays showed that the higher the TiO2 concentration the higher the UV barrier.

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  • IPEN-DOC 27666

    BARTOLOMEI, S.S.; BARTOLOMEI, M.R. ; MOURA, E.M. ; WIEBECK, H.; OLIVEIRA, R.R. . Effect on flame propagation in recycled expanded polystyrene with flame retardant/white clay/titanium dioxide nanocomposite. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Polystyrene is widely used in construction due to its properties such as low density, heat resistance, durability and ease of processing and molding. However, it is highly flammable, releases a lot of heat and toxic smoke when exposed to a flame. However, in order for a material to be applied in habitable indoor environments, it must comply with fire safety standards, which predict the behavior of materials during their burning. Halogenated flame retardants have been used to reduce the spread of flame, but they are toxic and polluting, so more environmentally friendly products are being developed. Polymeric nanocomposites, formed by inorganic nanoparticles, have many advantages in flame retardation, such as low heat release rate, low smoke and toxic gas production. Alternatively, the organofilized, exfoliated or polymer-intercalated montmorillonite clay (MMT) can be used to form a nanocomposite with greater flame resistance. However, for the clay to achieve the results required by the standards, it is necessary to add a large amount of particles, which generates agglomerates in the material and losses in the mechanical properties. Therefore, the use of clays to improve flame resistance to the material must be accompanied by the use of other flame retardants. Thus clay will provide reduction in flammability and secondary flame retardant will provide ignition resistance. The addition of other particles, together with clay, can corroborate with the reduction in flame spread of the material, with titanium dioxide being used to increase thermal stability, UV light stability, mechanical properties as well as reduction in flame spread. In this work expanded polystyrene (EPS) from construction waste, with flame retardant in its composition, was recycled and plasticized with glycerol. In this polymeric matrix was added white clay and titanium dioxide in order to maintain the flameproof properties and improve the mechanical and thermal properties of the material. The results showed that it is possible to recycle EPS and maintain flame self-extinguishing through the material even in the presence of glycerol as plasticizer. The addition of white clay improved the mechanical properties of the material and increased thermal stability, but impaired the fire behavior of the material, ceasing to self-extinguish the flame immediately after extinguishing the external flame. Titanium dioxide (TiO2) kept the mechanical and thermal properties unchanged and reduced flame propagation in the specimen when compared to the results of clay nanocomposite.

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  • IPEN-DOC 27665

    FUNGARO, D.A. ; CARVALHO, F.B. ; ROVANI, S. ; SANTOS, J.. Effect of experimental variables on the extraction of nanosilica prepared by sugarcane bagasse ash. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Sugarcane bagasse is one of the important biomass sources in Brazil, which is used as a fuel in the sugar industry. As a result, a large quantity of ash is generated and creates a serious disposal problem. The waste bagasse ash can be used as a valuable material to obtain nanosilica. Initially, NaOH was mixed with sugarcane bagasse ash (ash:NaOH 1:2 w/w) and the resultant mixture was fused at 350 °C for 30 min. Next, sodium silicate was solubilized in water and nanosilica was produced by neutralizing with acid. The structure, properties and yield of silica produced is strongly influenced by the extraction method used. Therefore, the silica extraction was conducted using various type of acid (hydrochloric, sulfuric and acetic), acid concentration (0.5; 4.0; and 8.0 mol L-1) and gelation pH (2, 4 and 7 for hydrochloric and sulfuric acids and 4, 5 and 7 for acetic acid). The synthesized nanosilica characteristics were studied using various techniques. Experimental results showed that hydrochloric acid and sulfuric acid produced nanosilica materials with similar yield and purity in each different process parameter. The production of nanosilica particles with the addition of acetic acid was the least favorable under the study conditions, probably due to its weak acid characteristic. The purity of all the synthesized silica nanoparticles is in the range of 94-98% and impurities such as sulfur and iron were presents as main minor compound. The study reveals that the industrial waste material sugarcane bagasse ash acts as an alternative source for the production of nanosilica powder widely used in areas such as ceramics, chemicals, catalysis, chromatography, energy, electronics, coatings, stabilisers, emulsifiers and biological sciences.

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  • IPEN-DOC 27664

    PARRA, D.F. ; LIMA, V.d. ; LUGAO, A.B. ; COTRIM, M.H. . Synthesis and characterization of encapsulation of silver nanoparticles with luminescent methyl polymethacrylate (PMMA). In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Rare earths have improved their importance owing to optical properties not only in the research area, but also in industrial and technological areas. Due to it higher luminescent intensity, Eu3+ complexes are among the most studied rare earth complexes that present luminescence, due to the structures of their energy levels. Combination with high molar absorptive ligands can promote a high emission of the Eu3+ ions. The present study concerns to luminescent doped polymers from methyl polymethacrylate (PMMA) used as a matrix for the development of luminescent films. The rare earth complex [Eu (tta)3 (H2O)2] was synthesized and used as a precursor for the synthesis of the secondary complex [Eu (tta) 3 (TPPO)2]. Silver nanoparticles synthesized and encapsulated in luminescent polymeric system showed distint luminescence behavior in the presence of those nanoparticles. After synthesis, the films were characterized. Investigation of the thermal behavior used differential exploratory calorimetry (DSC) and thermogravimetric analysis (TGA) techiniques. The characteristic fine emissions of the metal ion from the 5D0 ? 7FJ transitions (J = 0-4) indicated the incorporation of Eu3+ ions from both complexes in the matrix. The films showed the increase of the luminescence intensification of secondary complex in relation to the precursor complex. When encapsulating the silver nanoparticles to the luminescent systems, the luminescence intensity of these materials increased under conditions of low concentrations of the complex.

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  • IPEN-DOC 27663

    CARNEIRO, F.W. ; KAWABATA, V.J. ; JACOVONE, R.M. ; ANGNES, L.; GARCIA, R.H. ; SAKATA, S.K. . The synthesis of palladium nanoparticles by electron beam into graphene oxide and its electrochemical behavior. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: In this work, graphene oxide (GO) was synthesized by the modified Hummers method and was used as support for palladium nanoparticles to study its electrochemical behavior. The main objective was the incorporation of Pd on the graphene oxide by the electron beam irradiation at 40kGy and 80kGy doses. The GO-Pd nanocomposite was characterized by thermogravimetry analysis (TGA), X-ray diffraction (XRD), electron transmission microscopy (TEM), zeta potential analysis and cyclic voltammetry (CV). The results were satisfactory, indicating success in incorporating the metal in the GO surface. CV studies were conducted using screen printed electrode modified with nanocomposite, SPE/GO-Pd, at a scan rate of 50 mVs-1, potentials range from -0.5 V until 1.0 V in KCl medium (0.05 mol.L-1) adding aliquots of 4 mmol L ?1 ferricyanide solution and its results showed a linear increase in the current. It can therefore be inferred that palladium /graphene oxide nanocomposites have a potential for sensors.

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  • IPEN-DOC 27662

    KAWABATA, V.J. ; CARNEIRO, F.W. ; JACOVONE, R.M. ; ALMEIDA, E.V. de; GARCIA, R.H. ; CORIO, P.; SAKATA, S.K. . The synthesis of magnetite/reduced graphene oxide nanocomposites by electron beam for eletrocatalysis application. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: This work presents the synthesis of magnetite/reduced graphene oxide nanocomposites (MrGO) via electron beam. The graphene oxide (GO) was prepared according to a modified Hummers’ method and it was characterized using X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Raman spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), zeta potential analysis and cyclic voltammetry (CV) were used in order to investigate the structure and properties of MGO. The data showed GO was reduced using 40 kGy. The CV was performed by applying a MrGO layer on the working electrode of a screen-printed carbon electrode, at a scan rate of 50 mVs-1, potentials range from -0.5 V until 1.0 V in KCl medium (0.05 mol.L-1) adding aliquots of 4 mmol L ?1 ferrocyanide solution. Its results show a similar electrochemical response from both samples (maximum current: 45?A). It can therefore be inferred that magnetite/reduced graphene oxide nanocomposites have a potential for electrocatalysis application.

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  • IPEN-DOC 27661

    NOTARIO, A.O.; RIELLO, F.N. ; FERREIRA, K.d.; MEDEIROS, E.S.; FILHO, L.G.. Screen-printed electrodes functionalization using polimeric matrices. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Biosensors are analytical devices able of converting a biological response into a signal of another nature. In electrochemical biosensors electrode functionalization is a fundamental step. The surface of the electrode, where the interaction with the biological sample occur, must be properly treated so that the signal can be captured in the best way possible, without noise interference and for reproducibility. We aim in this work to use polymeric structures, called blanket, to stabilize the surface of screen-printed electrodes. The blankets are composed of hydrophilic and hydrophobic polymers blend enriched with nanomaterials and were manufactured using the solution blow spinning (SBS) technique. The blankets were placed in contact with the electrode surface and the functionalization by polymer deposition was induced through the current flow. Subsequently, the modification was validated from voltammetry readings and impedance spectroscopy. Scanning electron microscopy showed that there was no change in the microscopic surface of the treated electrodes. However, the blankets were able to improve the reading signal, increasing the active area and current flow and homogenizing the readings between the electrodes. These observed effects may be related to a chemical change in the electrodes and not a physical one. The strategy presented here has the advantage that the polymeric matrices are easy to obtain and inexpensive and can be enriched with various materials. Ensuring that the electrode functionalization step is efficient is essential for the construction of a biosensor, as it also ensures that the capture molecules deposit in a similar manner in each repetition. Finally, this standardization step enables new platforms to be built for disease diagnosis and detection of specific targets.

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  • IPEN-DOC 27660

    RIELLO, F.N. ; NOTARIO, A.O.; GOULART, I.B.; GOULART, L.R.. Electrochemical immunosensor using magnetic capture for disease diagnosis. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Immunosensors are small devices that use biological reactions, relying on antigen-antibody binding to form an immune complex. Methods involving this detection have shown great possibilities for the diagnosis of diseases, but there are still some limitations. In a search for new techniques to increase specific recognition between biomolecules and electrode surface adhesion with faster, lower cost and portability for point-of-care tests, an antibody-coupled magnetic nanoparticle capture system was developed in order to detect antigens in an electrochemical biosensor. Mycobacterium leprae samples were used as an experimental model of more accurate diagnostic tools for this disease. Magnetic iron oxide (Fe3O4) nanoparticles were bioconjugated by covalent binding with M. leprae specific antibody (anti-PGL-I) using EDC promoting direct binding and NHS for stability. Slit-skin smear from leprosy patients with different bacillus concentrations and healthy contacts (negative control) previously quantified by real-time PCR (qPCR / RLEP) were incubated with the bioconjugate and adsorbed on the modified screen-electrode work area. The readings were taken in cyclic voltammetry with portable potentiostat support electrolyte and the PSTouch smartphone software was used to interpret the results. Voltammogram curves have qualitatively discriminated positive from negative samples. Quantitative differences were given by means of logarithmic calculations of the highest values of oxidation peaks in cyclic voltammetry and calibrated based on the number of bacilli previously quantified by qPCR. The novel biosensor presented a detection range from 1 to 1,000,000 bacilli. Briefly, our immunosensor was the first successfully prototype demonstrated for M. leprae detection in direct biological samples from patients. The strategy of magnetic antigen capture proved to be efficient by increasing the sensitivity of the test, because this technique allows the recognition and precipitation of specific antigens. Although it has been used for a specific model, this type of sensor can be applied to different types of diagnostics using antigen and antibody recognition, as the methodology used for bioconjugation is not restricted to the antibody used here. It is also efficient for samples that are difficult to process and where the analyte concentration is low. It is important to emphasize that the new biosensor is portable, fast, sensitive, specific, low-cost and ideal for field screening programs.

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  • IPEN-DOC 27659

    GOMES, D.S. . A survey of accident tolerant fuel composed of uranium dioxide sintered with graphene nanoplatalet. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Global energy demanded should grow by 30% between today and 2040, and nuclear capacity will expand on 83%. Forecast scenarios point out that developing countries will invest in increasing their energy capacity by 45%. Today, nuclear power generates around 11.2% of global electricity, also considered as carbon emissions-free. Humanity must face various challenges to nuclear energy production because of safety operations conditions. In 2011, it started strategic plans, as accident tolerant fuel (ATF) sponsored by government agencies, industries, and universities. ATF introduced concepts that represent enhanced thermal conductivity, improved mechanical response, and radiation stability. It should replace the conventional UO2, also extend the copy time for accident scenarios. Nowadays, it grows the application of carbon materials for electronic devices, aerospace, and nuclear technology. Graphene platelets diffused in UO2 can enhance thermal conductivity around 30% and improve mechanical strength. Using nanocarbon dispersion on the uranium matrix can achieve a lower thermal gradient. The route adopted the spark plasma sintering technique to avoid the graphitization of carbon atoms. At present, the sintering of UO2 may take up a few hours, high temperatures, and energy to furnaces. Graphene is a two-dimensional honeycomb lattice of carbon atoms. Carbon nanotubes are cylindrical shapes, showing diameters of 1-3 nm, formed by graphene sheets. The calculation of the performance of UO2-Graphene used a fuel system with many physical properties updated. UO2-Graphene shows enhanced thermal conductivity and increased the capacity to keep fission gas releases into ceramic fuel.

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  • IPEN-DOC 27658

    GOMES, D.S. ; OLIVEIRA, F.B. . Thermal analysis of nuclear fuel using silicon carbide nanocomposite dispersion in UO2. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: After the Fukushima Daiichi disaster happened in Japan in 2011, it started a global effort to get more tolerant fuels. In 2019, the fleet of power reactors designated for electricity suppliers made up 451 power units, generating around 402 GWe. The nuclear power represents 11.2% of the electricity generated, avoiding about 1.2 GT of CO2. The civilian reactors are operating using the uranium dioxide (UO2) as the fuel, which shows poor thermal conductivity of 7.8 W/m-K at room temperature. The fuel temperatures can reach up until 1500 °C at regular operation. Silicon Carbide Nanotube (SiC-CNT) dispersed in the UO2 matrix containing 5 to 20% vol of SiC-CNTs permits to increases the thermal conductivity. The novel fuel concept improves the thermal conductivity of 30% with the addition of 5% of silicon carbide. The fuel pellet UO2-SiC/CNTs are sintered using Spark Plasma Sintering (SPS) with a hold time of 5 minutes, at 1300 °C, and a pressure of 40 MPa. The fuel mixture shows a better density, low porosity, and acceptable grain size distribution compared to traditional sintering routes. It simulated the fuel mixtures using fuel performance code FRAPCON adapted to the thermals and mechanic properties of compounds. This study showed the possibility of increasing the safety margins of nuclear fuel using the addition of a small fraction of nanocomposite.

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  • IPEN-DOC 27657

    MOURA, E.A. ; SANTOS, B.S. ; ISHIKAWA, O. ; SANTANA, J.G. ; BARTOLOMEI, M.R. ; OLIVEIRA, R.R. . Graphene oxide nanosheets as fillers for thermoplastic-matrix nanocomposites. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Recent studies have shown that the synthesis of graphene oxide (GO) by chemical oxidation of graphite followed by its reduction is one's the most promising routes to prepare remarkable polymer/graphene nanocomposite materials with significant improvement of properties compared to the base polymer. The addition of a very small amount of reduced graphene oxide (RGO)in a polymer can enhance its properties, with respect to electrical conductivity, barrier resistance, stiffness, abrasion resistance, mechanical resistance, and fire retardancy. Numerous approaches have been established to prepare RGO from the desoxygenation of GO. This work presents the synthesis of graphene oxide by chemical oxidation of graphite followed by its photoreduction in aqueous dispersion using UV radiation and highlights some examples of RGO/thermoplastic-matrix nanocomposites prepared by melt processing. To evaluate the potential application of thermoplastic composites prepared, the RGO's content on the morphological, mechanical and thermal properties of the as-obtained nanocomposites has been assessed. In addition, GO/RGO nanosheets were characterized by ATR–FTIR, XRD, Raman, and FE-SEM. According to the results, it can be inferred that the addition of RGO leads to a remarkable improvement in the performance of thermoplastic-matrix nanocomposites and offers a competitive solution for various potential applications.

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  • IPEN-DOC 27656

    PARRA, D.F. ; BASSETTI, C. ; KOMATSU, L.G. . Biocide effects of f nanoparticles of ZnO and ZnO-doped-Ag application in polymeric blend of HMSPP/SEBS. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: In this study, the nanoparticles of Zinc oxide (ZnO) and Zinc oxide doped with Silver (ZnO/Ag) were synthesized in laboratory. The incorporation of these nanoparticles in the blend of High Melt Strength Polypropylene (HMSPP) and Styrene-Ethylene/Butadiene-Styrene (SEBS) was carried by melting process. The obtained materials were evaluated by X-ray diffraction (XRD), Raman Spectroscopy, Differential Scanning Calorimetry (DSC), biocidal tests against the bacteria E.coli and S.aureus following the JIZ 2801 standard. The nanoparticles sized between 100-200nm have spherical form. HMSPP / SEBS / films incorporated with the nanoparticles AgNPs / ZnO showed biocidal effect against the bacteria E.coli and S.aureus.

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  • IPEN-DOC 27655

    KOMATSU, L.G. ; OLIANI, W.L. ; LUGAO, A.B. ; PARRA, D.F. . Synthesis of TiO2-doped- Ag for biocide activity on SEBS/PP applications. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Antimicrobial activity represents a challenge for scientific community. Polymer processing conditions impose temperature limitation for stability of biocide nanoparticles. In the present work, we evaluate TiO2-doped-Ag synthesized in laboratory, utilizing P25 Degussa Titanium Dioxide as precursor. The main proposal is to improve the incorporation of Ag on TiO2. The nanoparticles was tested by reduction of colony units formation (CFU)(%), Dynamical Light Scattering (DLS) and Zeta potential values. On CFU tests, all samples showed biocide properties. The samples showed biocide effect on E.coli and S.aureus bacteriae. The same nanoparticle was tested after sterilization under gamma irradiation, and showed an increase on biocide effect against S.aureus bacteria. The obtained biocide material was processed in SEBS/PP to obtain biocide polymeric films. The new material was characterized by: forming colony units (CFU)(%), Differential Scanning Calorimetry (DSC), and Fourier Transformed Infrared (FT-IR).

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  • IPEN-DOC 27654

    BALOGH, T.S. ; KADLUBOWSKI, S.; BONTURIM, E.; LUGAO, A.B. ; VARCA, G.H. . Influence of argon and nitrous oxide on the synthesis of PVP nanogels prepared by gamma radiation. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Nanogels are innovative systems with great potential for use in chemotherapy, disease diagnosis, release of bioactive substances, vaccines, cell culture systems, biocatalysis, in the generation of bioactive scaffolds in regenerative medicine among other applications. The definition of this material can be directly derived from the definition of polymeric gel, that is, a two-component system consisting of a permanent three-dimensional network of linked polymer chains and solvent molecules filling the pores of this network. Its internal structure is similar to that of hydrogels however presents particle size range varying from 0 to 100 nm leading to several advantages. Nanogel production methods involve intramolecular crosslinking that can be achieved using ionizing radiation. This method avoids the addition of any additives allowing the reaction to be carried out in a pure polymer-solvent system and the production of nanogels for biomedical applications free from monomer and crosslinking agents or surfactants. In this work influence of argon and nitrous oxide on the formation of nanogels by gamma irradiation has been evaluated. The samples were prepared in duplicate in multipurpose cobalt-60 gamma irradiator using a 25 mM PVP solution. Samples were irradiated in argon and nitrous oxide conditions with doses from 1 kGy up to 25 kGy with 10 kGy/h dose rate. These samples were morphologically characterized using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) as well as the pristine PVP solution. The mean particle size of the samples and the polydispersity index was performed in equipment Zetasizer Nano ZS - Malvern® and the determination of radius of gyration and molecular weight was performed in equipment Heleos - Wyatt®. It was observed in the conditions evaluated that saturation with argon or nitrous oxide promoted similar results except for 25 kGy dose. At this dose larger mean particle size and radius of gyration were observed in the sample saturated with nitrous oxide.

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  • IPEN-DOC 27653

    NASCIMENTO, A.C. ; PASSOS, P.d. ; LIMA, M.M. ; GALISTEO JUNIOR, A.J.; VIEIRA, D.P. . Mouse mioblast (C2C12) spheroids structured using paramagnetic iron nanoparticles as an in vitro culture system of Toxoplasma gondii tachyzoites. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Tridimensional cell culture techniques became essential for understanding physiological processes that are obliterated or fainted in conventional bi-dimensional cultures. These techniques are prone to produce more realistic modeling of the complex environment of living tissues, leading to much better understanding of mammalian tissue organization. This work used magnetic levitation of cell aggregates (spheroids) by adsorbing iron nanoparticles to C2C12 mouse (Mus musculus) mouse line cells (ATCC # CRL-1772), which are suspended with magnetic fields. The cells formed three-dimensional bodies that were cultivated suspended in the air-liquid interface. Magnetite (Fe3O4) nanoparticles with mean diameter of approximately 50 nm were produced by an alkaline coprecipitation methodology under reduction by microwave energy. Composition and size of crystallites were determined by DRX analysis. Adsorption on cell membranes occurred after functionalization with poly-L-lysine. Work concentrations of nanoparticles did no induce cytotoxicity in C2C12 monolayer cultures. Transmission electron microscopy of spheroid sections showed some findings morphologically compatible to the shape of reproductive intracellular vacuoli of T.gondii after cell invasion, demonstrating an interaction of cells with parasites in three-dimensional models.

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  • IPEN-DOC 27652

    MOREIRA, R.P. ; FELINTO, M.C. ; BRITO, H.F.. Synthesis of tungstates nanoparticles with luminescent properties. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Nanomaterials doped with rare earth ions have attracted great attention due to their unusual optical and electronic properties which leads these materials to be looked at as potential materials for application in the fields of high performance luminescent devices, lighting, magnets, catalysts, medical diagnostics, markers biological luminescent, etc. The advantages of using lanthanide ions as luminescent markers are numerous: it is a safe, low cost method, has higher specificity, the tests are more sensitive and the luminescence can be measured quickly, with a high degree of sensitivity and accuracy. [1-3] Among the methods used in obtaining nanocrystals can be mentioned: coprecipitation, sol-gel, microemulsion, microwave, polymer precursor, among others. In recent years, the polymer precursor (Pechini) and combustion methods are being used with greater emphasis due to the race to obtain nanoparticulate compounds, with homogeneous morphology in order to improve the performance of luminescent materials with application in nanotechnology. The Ba(1-x)WO4:xEu3+ powders were synthesized using the Pechini method, where the solutions of the salts of the Ba2+ and Eu3+ percussors in the form of NO3 ions. The 1: 4 citric acid and ethylene glycol solutions were added in the form of heat and heat to form a polymer resin, the pH being adjusted to 7 with ammonium hydroxide so that a brown, transparent resin . This resin was heated at 300°C for 2 hours, resulting in a black mass, which was prepared for the preparation of the precursor in powder form. The precursor was calcined at a preset temperature of 900°C for the production of barium tungstate.

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  • IPEN-DOC 27651

    ROCHA, M.d. ; ANDRADE, D.A. ; MOREIRA, P.G. ; STEFANIAK, I. ; MARTINS, J.G. . Investigation on the improvement of thermal properties of TiO2 nanofluids. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: This work aims to investigate the thermophysical properties of TiO2 nanofluids in the water base experimentally and also comparing results with existing literature data and theoretical models. Studies reveal that nanofluids present increasing in thermal conductivity and other important properties related to the heat transfer capacity compared to the base fluid. In this way, it can be classified as promising fluids for heat transport applications. As the proposal is to use it in high thermal flux systems, the survey of experimental measurements was performed to verify whose of the main parameters have more influence over such properties. Thermal conductivity, viscosity, surface contact angle and some visualization of nanoparticles in SEM were carried out in order to understand the nanofluids properties modifications. The TiO2 nanofluids in water base solutions were prepared for this study using the ultrasonic dispersion technique for three distinct volume concentrations: 0.1%, 0.01%, and 0.001%. Samples were initially prepared using an ultrasonic disrupter to make a homogeneous solution. This is an important step in sample analyses concerning the homogeneity influence on thermal conductivity measurements. With all samples prepared, some steps were followed to ensure the dispersion of nanoparticles and thus obtaining more accurate results Nanofluids samples were visualized in a scanning electron microscope (SEM) JEOL, model JSM 6701F at IPEN. Figure 2 shows the TiO2 nanoparticle's image observed. Preliminary tests for determining the thermophysical properties of nanofluids were: density, thermal conductivity, viscosity and surface contact angle. Concentration and temperature effects were investigated in preliminary tests for measurement of the thermal conductivity of nanofluids: this step consists of measuring the thermal conductivities and viscosities of nanofluids for all concentrations (0.001%, 0.01% and 0.1% vol.) at 15°C, 25oC and 35oC. ASTM D5334-08 (2008) describes the standard procedure for determining thermophysical properties and is based on the classical Linear Probe Method also known as the Transient Hot-Wire Method.

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  • IPEN-DOC 27650

    BATISTA, J.G. ; FREITAS, L.F. ; CRUZ, C.C. da ; LUGAO, A.B. ; RODRIGUES, A.S. ; SANTOS, L.O. ; PIRES, M.A. . Green nanotechnology: stability and interactions of gold nanoparticles obtained with Annona muricata extract. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Cancer is among the diseases with the highest mortality rate, with more than 100 different types that occur due to mutations in the genetic material of cells. It is the third leading cause of death worldwide after cardiovascular and infectious diseases. In addition, the number of diseases caused by oxidative stress that results from an imbalance between the formation and neutralization of oxidizing species is increasingly perceived. Oxidative stress is initiated by free radicals and their interactions with biological macromolecules, such as proteins, lipids and DNA, healthy human cells and cause damage to proteins and DNA, with lipid peroxidation. These changes contribute to cancer, atherosclerosis, cardiovascular and inflammatory diseases. All cells are exposed to oxidative stress and therefore oxidation and free radicals play an important role in the development of cancer. Medicinal plants have a special place in cancer management. Several cancer researchers have been carried out studies using traditional medicinal plants, to discover new therapeutic agents that do not have side effects associated with chemotherapeutic agents. Studies using the extract of Annona muricata L., popularly known as araticum, have demonstrated potential anti-inflammatory and anticancer action, due to its antioxidant and immunological properties. The objective of the present work was to develop gold nanoparticles using Annona muricata L. dry extract and verify their physical-chemical characteristics, such as size, shape, and stability. The results obtained show that it is possible to synthesize gold nanoparticles with potential applications in medicine using the extract of araticum. Characterization was performed using the techniques of UV-Vis spectrophotometry, dynamic light scattering (DLS), transmission electron microscopy (TEM). The in vitro stability study of the gold nanoparticles synthesized with the araticum extract was carried out for thirty days. The nanoparticles showed to be stable in different media during this period and the monitoring was done by spectrophotometry.

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  • IPEN-DOC 27649

    YAMAGATA, C. ; RODAS, A.C.; HIGA, O.Z. ; MELLO-CASTANHO, S. . Synthesis and characterization of a bioactive silicate ceramic from SiO2 nanoparticles. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Sol-gel and co-precipitation techniques have been used for synthesis of multiphase silicate ceramic from SiO2 nanoparticles. Non-aggregated colloidal SiO2 nano particles were initially prepared from a sodium silicate solution, by surfactant template sol-gel method. Afterward, calcium and magnesium hydroxides were co-precipitated on colloidal SiO2 nanoparticles surface. CaO-MgO-SiO2 sintered ceramic obtained from the synthesized powders were characterized by SEM,XRD and FTIR. In vitro tests were performed by soaking the sintered samples in the simulate blood fluid (SBF, at pH 7.25 and 37 ?C) to observe its bioactivity. After 7 days of immersion in SBF, the FTIR spectra analysis revealed that the material is bioactive, by the formation of hydroxyapatite on the surface of the sample. No toxic effect was found in the cytotoxicity tests with CHO (Chinese hamster ovary) cells.

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  • IPEN-DOC 27648

    LIMA, V.d. ; PARRA, D.F. . Study of luminescent effects on PMMA films with Eu3+/Ag nanoparticles. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Lanthanides, which are part of rare earths, have attracted attention due to their optical properties, not only in the field of research, but also in industrial and technological areas. Eu3+ ions are among the most studied of rare earth complexes because they have higher luminescence due to the structures of their energy levels. Combination with high molar absorptive ligands may promote higher emission of rare earth ions. The luminescent polymer system used as markers was obtained from doping with rare earth complexes, incorporating a Europrium complex containing trifluoroacetonate anion (TTA) in the process of encapsulating silver nanoparticles in methyl polymethacrylate (PMMA). The study will show that by introducing metallic nanoparticles, such as silver, it is possible to enhance the emission intensity in the luminescence processes of lanthanide compounds. The study of luminescence properties was performed by the spectrofluorimetry technique, showing that by introducing silver nanoparticles it will be possible to verify an increase of luminescence of the material in low concentrations of Europium complex. It will also be possible to observe an increase in material thermal stability through Thermogravimetric Analysis (TGA / DTG) performed under N2 atmosphere.

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  • IPEN-DOC 27647

    TAKARA, E.M. ; SOUZA, J.B. de ; CARVALHO, E.F.U. ; SILVA, A.S. . Kinects and factors on chemical dissolution of aluminum alloy AA6061 in NaOH alkaline media. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Nuclear Medicine is the Field of science that uses radioactive materials in order to diagnose and treat human body deceases. One of the most used radioisotopes for images diagnose purpose is the metastable technetium-99 (99mTc) because of its low decay half life (6 hours) and energy emission of 140keV that ensures low exposition time with the capacity of generating high quality images. The 99mTc is generated by the molibdenum-99(99Mo) radioactive decay during about 66 hours. The 99Mo is fabricated via nuclear fission of low encriched uranium (LEU) through plate irradiation targets (UAlx). The irradiation target cladding is made of Aluminum alloy AA6061 and its substrate is composed by 235U powder scattered in an AA1050 matrix. In general, studies are made targeting the prevention of corrosion mechanisms but the chemical dissolution in alkaline media, under hot cells, are one of the steps required for the post-processing methods of irradiation targets The time spent after irradiation is an important factor because the half life radioactive decay of the produced radioisotopes is relative short, then the procedures of dissolution, extraction, purify and distribution must be optimized in order to increase efficiency. This work presents a study of the factors impact involved on the chemical dissolution of the cladding aluminum alloys (temperature, NaOH solution concentration and dissolution time) as well as the kinects of the process associating it with the formation and destruction of oxides using electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). It was found that the involved parameters contribute individually more effective and that there is no relevant association between the factors. Solution temperature showed to be the most influent factor following by exposition time. It was presented a equivalent circuit model which demonstrates the reaction kinects and the growing of passive layers that slow down the process before it turns up into a soluble phase.

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  • IPEN-DOC 27646

    LANGE, C.N.; PELEGRINO, M.T.; KOHATSU, M.Y.; SEABRA, A.B.; BATISTA, B.L.; MONTEIRO, L.R. ; URZEDO, A.L.; JESUS, T.A.; GOMES, D.G.; OLIVEIRA, H.C.. Copper nanoparticles are an effective tool to increase endogenous nitric oxide and have beneficial effects on lettuce seedlings. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Copper oxide nanoparticles (CuO NPs) have been investigated as a solution for agriculture worldwide problems. CuO NPs are efficiently to inhibit several pathogens and they are been commercially used as nanopesticide. In addition, CuO NPs might be promising for plant growth, development and recovery of degraded soils. The molecular pathway leading to these remarkable features of CuO NPs administration may be related to nitric oxide (NO) signaling. NO is a molecular messenger related to abiotic and biotic stress responses. CuO NPs may increase copper ion in plant. The increase of copper ions is well known to decompose S-nitrosothiols (RSNO) and generate NO. Our purpose in this study was to investigate the effect of CuO NPs on lettuce (Lactuca sativa L.) seedlings and the role of NO in its process. CuO NPs were synthesized using green tea extract as the reductor agent. They showed an average size diameter of 6.6 ± 0.2 nm, as assessed by transmission electron microscopy (TEM). The lettuce seedlings were exposed to a wide CuO NPs concentration range of 0.2 to 300 µg mL-1 and the germination rate and radicle elongation were analyzed. CuO NPs concentrations under 40 µg mL-1 showed no phytotoxic behavior to lettuce seedling whereas concentrations equal or above 80 µg mL-1 showed moderate to strong phytotoxic behavior. The optimum concentration was found to be at 20 µg mL-1 which showed an enhancement of germination and radicle growth of lettuce seedling. To evaluate the overall oxidative stress of plant, the enzymes catalase (CAT), ascorbate peroxidase (APX), peroxidase activity (POD) and superoxide dismutase (SOD) were analyzed. SOD levels significantly decreased with the increase of CuO NPs concentration. The SOD enzyme is correlated to decrease reactive oxygen species (ROS), thus the observed toxicity in concentration above 80 µg mL-1 may be linked with higher levels of ROS. In addition, we quantified RSNO and nitrite (NO2-), measured by amperometric analysis, which are indicators of NO presence. RSNO and NO2- levels significantly increased with the increase of CuO NPs concentration. CuO NPs administration was effective to increase NO formation in plant. Low levels of RSNO and NO2- were observed to have beneficial effects to lettuce seedlings. Thus, CuO NPs concentration is a crucial factor to assurance its beneficial effect and the NO signaling pathway may have an important role underling this process.

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  • IPEN-DOC 27645

    JACOVONE, R.M. ; COSTA, C.A.; SAKATA, S.K. . Chemical characterization of bacteria: graphene oxide/Ag nanocomposite interactions by atomic force microscopy -infrared spectroscopy. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Atomic force microscopy -Infrared spectroscopy (AFM-IR) is a combined technique that allows nanoscale chemical characterization of biological–materials interactions. In this work, AFM-IR was used to map Escherichia coli in graphene oxide /silver nanocomposite (Ag/rGO). In Escherichia coli, it was observed absorption bands corresponding to amine I at 1660 cm-1 and amide II at 1550 cm-1 from proteins. On the other hand, when these bacteria were exposed to (Ag/rGO) typical absorption bands from carbonyl/carboxyl groups around 1745 and carbon bond around 1620 were also detected, showing the antibacterial activities of (Ag/rGO). The conventional atomic force microscope was used to elucidate the morphologic changes that occurred by internalization of nanocomposite into the bacteria. Atomic force microscopy -Infrared spectroscopy (AFM-IR) is a combined technique that allows nanoscale chemical characterization of biological–materials interactions. In this work, AFM-IR was used to map Escherichia coli in graphene oxide /silver nanocomposite (Ag/rGO). In Escherichia coli, it was observed absorption bands corresponding to amine I at 1660 cm-1 and amide II at 1550 cm-1 from proteins. On the other hand, when these bacteria were exposed to (Ag/rGO) typical absorption bands from carbonyl/carboxyl groups around 1745 cm-1 and carbon bond around 1620 cm-1 were also detected, showing the antibacterial activities of (Ag/rGO). The conventional atomic force microscope was used to elucidate the morphologic changes that occurred by internalization of nanocomposite into the bacteria.

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  • IPEN-DOC 27644

    RIELLO, F.N. ; VARCA, G.H. ; LIMA, C.S. ; FREITAS, L.F. ; FERREIRA, A.H. ; LUGAO, A.B. . Synthesis and purification of albumin-based nanoparticles crosslinked by radiation. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Protein-based nanoparticles have been proved a promissing alternative for the loading and delivery of chemotherapeutic agents, radiopharmaceutics and other drugs of interests, constituting a less toxic therapeutic option due to its biocompatibility and low or null side effects. The use of radiation to crosslink or form covalent bonds enables the controll of the crosslinking process, without the need for crosslinking agents, as well as provides sterilizations simultaneously, withouth generating toxic compounds or products. The present work targets the synthesis an purification of albumin-based nanocarrier crosslinked by gamma radiation for biomedical applications. For such purpose, albumin nanoparticles were synthesized using BSA at 20% ethanol (v/v) in 50 mM phosphate buffer on an ice bath prior to and after irradiation. Samples were exposed to gamma radiation at a minimun absrobed dose of 10 kGy at 5kGy.h-1 and purified using a SuperdexTM 200 Increase 10/300GL for isolating the crosslinked protein (high molecular weight) from the native BSA. After the purification, the fractions were characterized by electrophoresis, Uv, fluorescence and dynamic light scaterring. The nanoparticles were obtained in the range of 25-40 nm and purified into fractions of high molecular weight and the native ones. The high molecular weight fractions presented increased bityrosine levels if compared to the fraction corresponded to the native BSA. The yields of nanoparticle formation remains to be determined, but our results provided a clear evidence of the formation of radiation-crosslinked BSA nanoparticles and the role of bityrosine in the nanoparticle assembly.

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  • IPEN-DOC 27643

    FRANCISCO, L.H. ; FELINTO, M.C. ; BRITO, H.F.. Hydrothermal synthesis of rare-earth doped nanoparticles for energy conversion and storage. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: In recent years, several classes of rare-earth doped luminescent nanoparticles have been drawing attention due to complex energy converting systems that can be structurally engineered to tune absorption and emission wavelengths, outlining novel materials and applications on photonics [1-2]. In this scenario, this work presents the development of rare-earth doped core-shell SrAl2O4:Eu2+/3+, Dy3+ nanoparticles prepared via hydrothermal synthesis and post-annealed on carbon monoxide reducing atmosphere, which exhibit appealing spectroscopic properties for solar energy conversion and storage. The prepared strontium aluminate phosphors were further amino-functionalized with 3-aminopropyltrimethoxysilane (APTMS) and ?-diketonate rare-earth complexes by microwave assisted synthesis [3], in order to enhance its absorption section and energy-transfer processes within the system. Prepared samples were analyzed by X-ray powder diffraction, which revealed a stable monoclinic phase of pure strontium aluminate accordingly to PDF34-379. Crystallite size was estimated by the Scherrer method, indicating dimensions of about 25 nm. Moreover, standard luminescence spectroscopy results of pure SrAl2O4:Eu2+/3+, Dy3+ showcased characteristic green Eu2+ emission assigned to the 4f65d1?4f7(8S7/2) interconfigurational transition under near ultraviolet excitation. It was also found that amino-functionalized samples display distinguished emission spectral profiles, as Eu2+ emission shifts on ?-diketonate coated samples, suggesting an effective interaction between the inorganic host-matrix, the silica network and the ?-diketonate complexes. Likewise, acquired excitation spectra monitored on Eu2+ emission revealed its characteristic broad band in the ultraviolet region, as well as non-reduced Eu3+ narrow absorption lines. In addition, ?-diketonate S0?Sn transitions were also observed on functionalized samples, unveiling an increasing absorption section under ultraviolet light. Finally, it is highlighted that prepared SrAl2O4:Eu2+/3+, Dy3+ persistent phosphors displayed intensifying characteristic green emission under UV light due to imposed surface modification processes by functionalization. Therefore, as its emission wavelength overlaps with a commonly used dye (N719) in dye-sensitized solar cells, the materials assembled in this work aspire to enhance energy conversion efficiency and storage on such photovoltaic devices.

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  • IPEN-DOC 27642

    NOGUEIRA, K.M. ; VARCA, J.O. ; LIMA, C.S. ; CRUZ, C.C. da ; RIBEIRO, A.H. ; FREITAS, L.F. ; VARCA, G.H. ; LUGAO, A.B. . Development of Lignin/PEO nanofibers by electrospinning technique for tissue engineering application. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Lignin is a renewable carbon source and has been widely explored in different areas over the last years, especially in biomaterials such as dressings and other biomedical devices due its natural origin and low cost. Its chemical structure confers interesting properties such as antioxidant capacity, UV protection, bactericidal action and appropriate adsorption. Poly (ethylene oxide) (PEO) is used in electrospinning to facilitate the formation polymer fibers. The electrospinning technique has been largely explored in the bioengineering area towards designing nanomaterial with minimum defect and high surface area. The present work aimed the development of a lignin/PEO nanofiber by electrospinning technique. In practical terms, lignin/PEO solution was prepared following two different methods. In the first approach, polymer stock solutions were prepared in alkaline water by stirring at 70 °C. In the second, the polymer powders were mixed and dissolved together in dimethylformamide (DMF) under stirring at 80 °C. By both methods, PEO/lignin solutions were prepared at 10, 20 e 30% (w,v) solid content, at the ratios 99/1 and 95/5. For electrospinning parameters, the distance between ejector and plate collector was set to 15-20 cm, voltage to 20 kV and injection flow to 1 mL/h, chamber temperature to 40 °C and 30%. Nanofiber morphology was assessed by scanning electron microscopy and optical coherence tomography. Apparent porosity was measured by classical Archimedes method. Due to higher DMF dielectric constant compared to water, results showed that nanofibers made using DMF presented smaller beats formation and smaller fiber diameter. Nanofibers with higher solid content presented more uniform fibers with larger diameter. Nanofibers with higher lignin concentration presented larger number of beats and higher fiber diameter. However, lignin improved the system porosity in all cases. Further mechanical and biological experiments will be done, nevertheless, the nanofiber developed is a promising material to be applied in tissue engineering.

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  • IPEN-DOC 27641

    MOURA, E.A. ; ISHIKAWA, O. ; MANGIERI, F. ; BARTOLOMEI, M.R. ; BARTOLOMEI, S.S.; OLIVEIRA, R.R. ; FRANCISCO, D.L.; GUIMARÃES, K.. Sonochemical synthesis of reduced graphene oxide: methods and characterization. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: The reduction of graphene oxide (GO) by a safe and eco-friendly route, without the use of harmful chemicals, has drawn much attention as one of the most promising routes to produce graphene nanosheets, a 2D material with excellent electrical and thermal conductivity, optical and mechanical properties. Graphite exfoliation is widely performed by the chemical reduction of GO, which is commonly produced by oxidation of graphite using a strong oxidizing agent by Hummers’ method. This work presents a study of the influence of sonochemical application on synthesis of reduced graphene oxide induced by UV radiation. Commercial graphite powder was used as raw material. Firstly, graphite powder was dispersed into a DMF/deionized water solution and ultrasonicated using a high intensity ultrasonic device for 1 8 hours in other to reduce the particle sizes. After, sonicated graphite samples were frozen for 24 hours and freeze-dried for 24 hours to obtain the powder. Graphite powder obtained with different particle sizes was used to prepared GO through a chemical route. GO prepared was dispersed into a DMF/deionized water solution, ultrasonicated using a high intensity ultrasonic device for 1-2 hours, frozen for 24 hours and freeze-dried for 24 hours. Finally, GO powder samples were dispersed in a mixture of isopropyl alcohol, acetone, and deionized water and irradiated using UV radiation by different irradiation time to obtain reduced GO (RGO). The GO and RGO were characterized by BET, ATR–FTIR, XRD, Raman, TG, and FE-SEM analysis. In addition, graphite samples were characterized by BET, SEM and XRD analysis. The results showed that sonochemical application has a fundamental role in the synthesis of GO nanosheets and RGO. Ultrasonically prepared GO exhibited higher surface area, higher crystallinity and higher oxidation efficiency with many hydrophilic groups. FE-SEM analysis of the GO showed that sonochemical application reduced the aggregated domains and close stacking of sheets on the GO surface and led to obtaining reduced GO with a smooth surface, fewer layers and significant effective surface area.

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  • IPEN-DOC 27640

    LIMA, C.S. ; VARCA, G.H. ; OLIVEIRA, J.R. ; NOGUEIRA, K.M. ; SANTOS, F.A. ; RIBEIRO, A.H. ; LUGAO, A.B. ; FREITAS, L.F. ; ROGERO, S.O. . CMC and PVA hydrogel containing papain nanoparticles for drug delivery. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Four hydrogel formulations of Carboxymethylcellulose (CMC) and Poly (vinyl alcohol) (PVA) were prepared with native papain (AP and BP) and papain nanoparticles (AN and BN) for drug delivery. The formulations were evaluated for their preliminary stability, protein distribution in the matrix and cytotoxicity. Three methods for sterilization purposes were compared: irradiation by 60Co source, electron-beam and UV light. The preliminary stability test confirmed that the system was stable since there was no precipitation or alteration of the organoleptic properties of the samples in the evaluated period. The distribution of proteins in the hydrogel was very homogeneous in all the formulations. Quantification of the enzymatic activity of papain after contact with the gel showed that native papain maintained its activity high (86% and 93% for AP and BP gels, respectively), whereas there was a considerable drop in the activity of the papain nanoparticles to 60.54% and 69.44% for AP and BP gels, respectively. Such loss of activity is attributed to processing and/or process steps. The cell viability assay showed that the polymer matrix shows no cytotoxicity, corroborating with the literature, since the material is biocompatible. Thus, it is possible to affirm that the developed system presents potential for biomedical application, either as a vehicle of papain itself or for the transport of other drugs through complexation with papain nanoparticles. However, the need for further studies of stability, controlled release capacity and biocompatibility is required.

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  • IPEN-DOC 27639

    FREITAS, L.F. ; CRUZ, C.C. da ; BATISTA, J.G. ; VARCA, G.H. ; LUGAO, A.B. ; PIRES, M.A. . Stability of gold nanoparticles in different ionic concentrations and pH: a comparison among synthetic protocols. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: There are several protocols for the synthesis of gold nanoparticles, and lately there is a trend for green methods in order to minimize the environmental impacts. The reduction of gold salts by epigallocatechin 3 gallate, for instance, generates stable and uniform nanoparticles without the use of toxic compounds, and so does the radiolytic synthesis protocol. For medical purposes, proteins like albumin and papain are useful coating agents, providing a better biological effectiveness. Here we present a comparison of different synthetic and protein coating protocols for gold nanoparticles regarding their stability in different NaCl concentrations and pH, aiming for the development of nanoparticles that are able to be administered in physiologic solutions to patients. The nanoparticles were synthesized via EGCG (2 mg mL 1) reduction of gold salt (5 mmol L 1) in phosphate buffer pH 7.0. Those nanoparticles were coated or not with albumin or papain (1 mg mL 1) using mercaptopropionic acid. Other protein coated gold nanoparticles were synthesized radiolytically by mixing 5 mmol L 1 NaAuCl4 with 1 mg mL 1 bovine serum albumin (BSA) or papain and 0.1 mol L 1 tert butanol. The solutions were irradiated with 10 kGy (60Co source, 5 kGy h 1) and the resulting suspensions were stored until use. The suspensions were added in 96 well plates to solutions with different pH and NaCl concentrations, and their absorption spectra were taken periodically to verify their stability. It was observed that BSA gold nanoparticles synthesized by both protocols were stable in concentrations of NaCl varying from 0.1% to 14.4% up to 72h. The papain gold nanoparticles synthesized by both protocols were stable in concentrations of NaCl varying from 0.1% to 14.4% up to 48h, but in 72h there was evidence of instability in the lowest and highest NaCl concentrations. The nanoparticles coated just with EGCG (without proteins) were stable in all NaCl concentrations and times, except in the highest concentration after 72h. Regarding the pH, BSA gold nanoparticles and papain gold nanoparticles synthesized radiolytically, as well as EGCG gold nanoparticles were stable at least in pH varying from 5 to 11, in all times analyzed. In conclusion, all the nanoparticles tested are able to be administered to patients in physiological solutions, which have pH around 7.4 and NaCl concentrations around 0.9%, without the risk of aggregation and loss of biological activity.

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  • IPEN-DOC 27638

    MORAES, T.S. ; FERREIRA, J.C. ; BERGAMASCHI, V.S. ; SPINACE, E.V. . Core-shell catalysts for ethanol steam reforming reaction. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Hydrogen can be produced from the steam reforming (SR) of biomass-derived liquids such as bioethanol. The SR of ethanol for hydrogen production has several advantages. However, one of the main barriers to the commercialization of this technology is the deactivation of the catalysts due to the formation of carbon. Therefore, the development of catalysts that are stable and resistant to carbon formation is necessary. Several strategies have been used to avoid the deposition of carbon on the surface of the catalysts. Cerium oxide, at high temperatures or in the presence of reducers, can easily change oxidation state to form a non-stoichiometric oxygen deficient oxide. This oxide has a strong tendency to remain in the fluorite structure even after considerable oxygen loss, stabilizing the structure with a high number of oxygen vacancies. Other approach to minimize coke formation is to control the size of metallic particle through modifications in the catalyst structure. According to the mechanism reported in the literature, carbon formation in these reactions are favored in large sizes of metal particle. Therefore, controlling particle size is essential to reduce carbon accumulation on the catalyst surface during ethanol reforming reactions. One strategy for inhibiting the sintering process of metal particles in catalysts is the development of core-shell catalysts. These catalysts feature a metal core covered with an oxide layer, which gives them unique characteristics. The core-shell structure also accelerates the transformation processes of the carbon formed at the metal-oxide interface, favoring the gasification reaction and consequently its elimination in the form of CO2. Das et all have synthesized an innovative sandwiched core-shell structured Ni-SiO2@CeO2 catalyst that showed high activity and stability at dry reforming of biogas with negligible coke formation. The aim of this work is to investigate the performance of the structurally modified Ni-SiO2@CeO2 catalyst in the form of a sandwiched core-shell to inhibit the formation of carbon and increase the stability of the catalysts in the SR of ethanol reaction. This new form of catalyst synthesis has proved very efficient in other reactions but is still very little studied in the ethanol SR reaction. Silica nano-spheres were synthesized by the Stöber method and Ni-SiO2 catalysts were prepared via a Ni-phyllosilicate precursor route. Ni-SiO2@CeO2 will be prepare using the fresh Ni-phyllosilicate spheres that will be coated with a thin layer of CeO2 using a precipitation method. Silica nano-spheres and Ni-SiO2 were calcined at 1273 K for 1 hour with air. Samples were analyzed using transmission electron microscope (TEM) and x-ray diffraction (XRD). SR of ethanol was performed in a fixed-bed reactor at atmospheric pressure. Prior to reaction, catalysts were reduced under pure hydrogen at 923 K for 1 h. The reactions were carried out at 673K and H2O/ethanol molar ratio of 3.0.

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  • IPEN-DOC 27637

    BRITO, H.F.; FELINTO, M.C. ; FRANCISCO, L.H. ; SAULA, M.S.; MERIZIO, L.G.. Nanoparticles presenting the phenomenon of luminescent persistence make the difference in biological applications. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: The persistent luminescent materials are an important class of light-induced energy storage materials, which have undertaken a long development process. Recently, there has been increasing interest in employing long persistence luminescent nanoparticles (LPLNPs) for in vivo imaging. Because the long afterglow of these nanoparticles can last for several hours after they are excited in vitro, real-time in vivo imaging can be achieved after injection without requiring any external illumination source. Thus, the SNR can be significantly improved by removing the background noise originating from in situ excitations. Moreover, the afterglow luminescence of near-infrared (NIR)-emitting long-persistence luminescent nanoparticles (NLPLNPs) (the afterglow wavelength varies from 650 nm to 900 nm) falls within the tissue transparency window, where light attenuation is largely due to scattering rather than absorption, which is advantageous for long-term in vivo imaging with deep penetration and a high SNR1-3. In this work, we will be discussed the synthesis of these LPLNPs, the characterization and the luminescent properties especially the persistent luminescence intensity and lifetime that are the two important parameters to evaluate the persistent luminescent properties of materials. It was expected the materials to have a very high luminescence intensity and long persistent lifetime. The development of rare-earth doped core-shell SrAl2O4:Eu2+/3+, Dy3+ nanoparticles prepared via hydrothermal synthesis and p-st-annealed on carbon monoxide, in reducing atmosphere, or materials like Li1,6M1,6Sn2,8O8:R3+ (M2+: Mg, Zn and Cd; R3+: Cr, Nd, Yb), etc prepared by microwave-assisted solid-state reaction, ceramics method and co-precipitation reaction generate materials with efficient persistent luminescence and will be discussed in terms of electronic structure and syntheses methodology. Moreover, standard luminescence spectroscopy results of pure characteristic green Eu2+ emission assigned to the 4f65d1?4f7(8S7/2) interconfigurational transition under near-ultraviolet excitation. Some of these materials have special behavior and present persistent luminescence in the near-infrared, NIR, which is very important in terms of biological application point-of-view.

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  • IPEN-DOC 27636

    FELINTO, M.C. . Nanocrystals of BaWO4:Dy3+ and SrWO4:Dy3+ synthetized by green chemistry method. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Nowadays, the investigation of oxide based light emitting materials for white light emitting diodes (w-LEDs) or device applications have generated interest due to the advantages such as long lifetime, low energy consumption, high luminescence efficiency and environmental friendliness [1]. These qualities make them a strong candidate for the solid state lighting, display devices, optoelectronic devices and light-emitting diodes (LEDs). In this work, we present results of Dy3+: BaWO4 and Dy3+: SrWO4 that present luminescence close to white color (Figure 1) left. They were synthesized using co-precipitation method. The emission spectra exhibit four emission transitions centered at around 486 nm, 576 nm, 665 nm and 760 nm corresponding to the transitions 4F9/2?6H15/2 (blue), 4F9/2?6H13/2 (yellow) 4F9/2?6H11/2 and 4F9/2?6H9/2 6F11/2 (red) respectively. Among these transitions 4F9/2?6H15/2 and 4F9/2?6H13/2 are observed to be strong whereas 4F9/2?6H11/2 transition is found to be relatively quite weak. The 4F9/2?6H13/2 transition is hypersensitive in nature and is strongly influenced by the environment around the Dy3+ ion site. It is observed in the luminescence spectra of these materials that the electric dipole transition is dominant compared to the magnetic dipole transition. The CIE diagram show emission close to white (Fig.1 right) for the five composition with little distortion of the color showing the influence of dopant concentration in the color of the emission. Figure 1. Dy3+: BaWO4 under UV excitation (366nm) left, emission spectra under excitation at 350nm middle and chromaticity coordination diagram of BaWO4:Dy3+ material.

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  • IPEN-DOC 27635

    FERREIRA, A.H. ; MARQUES, F.N.; SOUZA, L.E. de; VARCA, G.H. ; REAL, C.C.; FARIA, D.d.; JUNQUEIRA, M.d.; LUGAO, A.B. ; FREITAS, L.F. . Radiolabeled protein nanoparticles for cancer diagnosis. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: Recent advances in nanomedicine and nanotechnology have expanded the development of multifunctional nanostructures which combine specificity, diagnostic and therapeutic functions in nanostructured complexes in order to overcome biological barriers that may hinder the selective and effective administration and uptake of drugs and diagnostic agents in tumor tissue. Nanoparticles have been used in nuclear medicine as nano-radiopharmaceuticals to carry PET and SPECT ?- and ?-emitting radioisotopes used in endoradiotherapy to specifically destroy tumor tissue. The aim of the present work was the study of radiolabeling of albumin (BSA-NPs) and papain (P-NPs) nanoparticles synthesized by gamma irradiation, with 99mTc and characterize their in vitro and in vivo properties as potential novel nano-radiopharmaceuticals. Electron microscopy and light scattering techniques show spherical shapes of nanoparticles and average diameter of 9.3 ± 1.9 nm for P-NPs and 25.1 ± 2.9 nm for BSA-NPs. The radiolabeling reached around 90% yield, and the 99mTc-BSA-NPs showed stability for 24 h in all assayed conditions, while 99mTc-P-NPs presented stability for 6 h in human serum. The biodistribution studies in healthy animals have shown different excretion profiles, 99mTc-P-NPs featured a renal excretion. On the other hand the 99mTc-BSA-NPs were found in the liver and spleen to a larger extent, undergoing hepatic excretion. In vitro studies showed promising internalization rates for both nanoparticles with 74% and 57.6% of total uptake in MDA-MB231 cells, respectively for 99mTc-P-NPs and 99mTc-BSA-NPs. In vivo studies in micro-SPECT/CT images also showed a high tumor uptake for both nanoparticles. The autoradiographic studies and immunohistochemistry assays revealed a high density of both papain and BSA nanoparticles in peripheral regions of tumor tissue and confirmed the efficacy of the developed nano-radioparmaceuticals for targeting breast cancer.

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  • IPEN-DOC 27634

    NOGUEIRA, B.R. ; SOUZA, C.D. ; CARVALHO, D.V. ; ROSTELATO, M.E. ; ROSERO, W.A. . A comparison of different coatings agents for gold nanoparticles obtained with a one-pot reaction with ascorbic acid. In: PAN-AMERICAN NANOTECHNOLOGY CONFERENCE, 2nd, March 4-7, 2020, Águas de Lindoia, SP. Abstract... 2020.

    Abstract: The materials at nanometric size sometimes present different characteristics when compared to the same material in macrometric scale. The gold nanoparticles (AuNPs) are an example, presenting different properties such as fluorescence, melting point, electrical conductivity, magnetic permeability, chemical reactivity, and even different color than usual. Those features are direct dependence on particle size, shape, and colloidal distribution. AuNPs have desirable attributes for medical applications such as excellent biocompatibility, low toxicity, and good optical and electronic properties. AuNPs are already widely used to carry nucleotides, antibodies, and proteins in addition to biotech applications. Spherical gold nanoparticles are mainly processed by Au3+ reduction to Au+ and Au0. With the use of a stabilizing ligand, the gold nanoparticles are capped and then further growth is avoided. In this work for each 100 mL of a 0.5 mM HAuCl4, 1 mL of 0.1 M L-Ascorbic Acid solution was added, as reduction agent, under a vigorous and constantly magnetic stirring at room temperature. Almost instantly, the reaction that was originally transparent, became black and then reddish, after continued stirring for 30 min more. Three different coating agents were used in this work (SH-PEG-NH2, Arabic Gum, and Biotin). A solution with 0.1 mM of each coating agent was prepared and then in a proportion of 1:1 they were added to the AuNPs solution and putted in an orbital shaker for 2 hours. For comparison a sample with just ultrapure water, instead of the coating agent was added. Bare AuNPs and each of the coated ones were compared by using dynamic light sizer (DLS) and UV-Vis, for size measurements; and Fourier transform Infrared spectroscopy was used to evaluate bonds between the nanoparticle surface and the coating agents. Preliminary results showed that AuNPs without any coating agent presented a total smaller size (ca. 51 nm) when compared with the (ca. 84 nm)coated ones. However UV-Vis peaks indicated that the cores of the coated AuNPs are probably smaller than the non-coated. The smaller core size may be due the addition of the coating agent stopping diffusion growth. FTIR was able to confirm the presence of the agents in the NPs surface. Further analysis such as transmission electronic microscopic should confirm these results.

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  • IPEN-DOC 27633

    PIMENIDIS, JORGE A.; TERAM, ROGERIO; NASCIMENTO, MAURICIO S.; SANTOS, VINICIUS T. dos; SILVA, MARCIO R. da; COUTO, ANTONIO A. ; SANTOS, GIVANILDO A. dos. Análise do comportamento elétrico de ligas de alumínio obtidas por solidificação unidirecional. In: HOLZMANN, HENRIQUE A. (Org.). Resultados das pesquisas e inovações na área das engenharias 3. Ponta Grossa, PR: Atena, 2020. p. 11-22, cap. 2. DOI: 10.22533/at.ed.1332023112

    Abstract: O objetivo deste trabalho é analisar se a macroestrutura resultante de solidificação unidirecional influencia no comportamento elétrico da liga Al-6%Zn. O comportamento mecânico e elétrico de produtos industrializados, em muitas vezes significa dar garantias de durabilidade e solidez nas mais variadas aplicações de esforços e robustez de composição química. O ensaio de condutividade normalizado, norma técnica ASTM B193 – 02 (2014), utilizado neste trabalho é adotado industrialmente. O método de comparação dos resultados com a tabela de resistividade dos materiais foi adotado para análise dos resultados. Os resultados mostram que a macroestrutura resultante da solidificação praticamente não influencia na condutividade e resistividade elétrica da liga estudada.

    Palavras-Chave: solidification; aluminium alloys; electric conductivity; grain size

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  • IPEN-DOC 27632

    CIPRIANO, ARIOVALDO M.; CRUZ, RICARDO A. da; TERAM, ROGERIO; NASCIMENTO, MAURICIO S.; SANTOS, VINICIUS T. dos; SILVA, MARCIO R. da; COUTO, ANTONIO A. ; SANTOS, GIVANILDO A. dos. Análise da influência do processo de solidificação unidirecional no comportamento elétrico da liga Cu-8,5%Sn. In: HOLZMANN, HENRIQUE A. (Org.). Resultados das pesquisas e inovações na área das engenharias 3. Ponta Grossa, PR: Atena, 2020. p. 1-10, cap. 1. DOI: 10.22533/at.ed.1332023111

    Abstract: O objetivo deste trabalho é analisar se as variáveis térmicas de solidificação influenciam ou não no comportamento elétrico da liga Cu-8,5%Sn. A liga foi solidificada em uma lingoteira de aço inoxidável AISI 304, montada em um dispositivo de resfriamento unidirecional ascendente. O ensaio de condutividade elétrica foi realizado pelo equipamento ponte de Wheatstone, que mede a resistividade elétrica, e com o medidor de condutividade obteve-se os valores em %IACS, conforme norma ASTM B193-02. Como resultados, notou-se que a condutividade elétrica não foi influenciada pelas variáveis térmicas de solidificação, obtendo-se valores de IACS praticamente constantes para a liga de cobre estudada.

    Palavras-Chave: solidification; electric conductivity; phosphorus; bronze; copper base alloys

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  • IPEN-DOC 27631

    COSTA, ROBSON S. ; ARAUJO, DANIELLE G. ; ANDRADE, MARCIO S. de ; OLIVEIRA, RENE R. ; RANGARI, VIJAYA; MOURA, ESPERIDIANA A.B. ; DIAS, FRANCISCO V.. Production and characterization of PBAT reinforced with clay and graphene oxide nanosheets: a comparative study. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 689-699, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_68

    Abstract: The poly (butylene adipate-co-terephthalate) (PBAT), a biodegradable polymer, is among the most promising materials to be considered as environmentally friendly high performance biodegradable plastics. However, the mechanical properties of PBAT are not the best for several applications. According to the literature, the properties of the biodegradable polymer can be improved by addition of a small amount of nanofillers, such as clay, silica, and graphene. The objective of this study is to compare the effect of the addition of Cloisite clay and graphene oxide (GO) on the properties of flexible films based on PBAT matrix. The composite films based on PBAT with addition of Cloisite (2.0 wt%) and PBAT composite films with addition of Cloisite and GO (0.1–0.2 wt%) were prepared by extrusion, using a twin-screw extruder and a flat die single extruder. The effects of the addition of Cloisite clay and graphene oxide on mechanical and thermal properties of films were evaluated by mechanical and water absorption tests, FE-SEM, XRD, and Raman analysis.

    Palavras-Chave: graphene; oxide minerals; nanocomposites; polymers; butenes; biodegradation; mechanical properties; flexibility

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  • IPEN-DOC 27630

    OLIANI, WASHINGTON L. ; KOMATSU, LUIZ G.H. ; LUGAO, ADEMAR B. ; RANGARI, VIJAYA K.; PARRA, DUCLERC F. . Processing and characterization of polyethylene-AgNPs films: biocide effect. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 679-688, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_67

    Abstract: Low-density-polyethylene (LDPE) and Linear-low-density-polyethylene (LLDPE) nanocomposites films containing silver nitrate (AgNO3) and surfactant oleic acid (AO) were manufactured via extrusion and subsequently characterised. The films were evaluated by scanning electronmicroscopy (SEM), energy dispersive spectroscopy (EDX), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and infrared spectroscopy (FTIR). Further, the antibacterial properties of the films were investigated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria.The results indicated that LDPE nanocomposite films containing AgNPs have the potential to be used in antimicrobial packaging for food applications.

    Palavras-Chave: nanocomposites; polyethylenes; silver nitrates; oleic acid; germicides

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  • IPEN-DOC 27629

    TAMURA, CAROLINE S. ; ARANTES, MARIANA ; CARMO, KARINA H.S. ; SANTOS, BIANCA S. ; OLIVEIRA, RENE R. ; MOURA, ESPERIDIANA A.B. . Mechanical and morphological properties of hybrid composites based on recycled LDPE/EVA blend reinforced with clay and babassu fiber residues. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 661-669, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_65

    Abstract: Over the years the consumption of plastic products made of conventional polymers has produced a large amount of waste which has led to disposal problems worldwide. Among the alternatives to minimize these problems are reuse and recycling practices. Then, the recycling of plastic and the use of recycled materials to produce new materials reinforced with nanoparticles from natural resources can be an alternative to reduce inappropriate waste disposal. The objective of this study is to investigate the effects of the addition of clay and non-treated babassu fiber residues on the mechanical and morphological properties of composite based on recycled LDPE/EVA blend. Composite materials containing 1–3 wt% of babassu residues and 1 wt% of clay were prepared using a twin-screw extruder machine and flat die single extrusion process, in order to prepare hybrid composites sheets. The sheets prepared by recycled LDPE/EVA blend and its composites were characterized by tensile tests, XRD, and FE-SEM analysis and the correlation between properties was discussed.

    Palavras-Chave: mixers; recycling; polymers; films; fibers; composite materials; hybridization

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  • IPEN-DOC 27628

    BARTOLOMEI, MARCIO R.X. ; CARMO, KARINA H.S. ; SANTOS, BIANCA S. ; BARTOLOMEI, SUELLEN S. ; OLIVEIRA, RENE R. ; MOURA, ESPERIDIANA A.B. . Investigation on mechanical and thermal behaviours of PBAT/PLA blend reinforced with reduced graphene oxide nanosheets. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 631-639, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_62

    Abstract: The aim of this study was to process and investigate the changes in the mechanical and morphological properties of the biodegradable nanocomposites based on polybutylene adipate-co-terephthalate (PBAT)/poly(lactic acid) (PLA) blend (PBAT/PLA blend) due to the incorporation of reduced graphene oxide (RGO) nanosheets. The biodegradable polymeric nanocomposites were prepared by melting extrusion process using a twin-screw extruder machine. The influence of the RGO nanosheets incorporation on mechanical and thermal properties of PBAT/PLA blend was investigated by tensile Thermogravimetric (TG), X-Ray diffraction (XRD), differential scanning calorimetry (DSC), and tensile test analysis. Results showed that incorporation of the small amount ofRGO(0.1wt.%) ofRGOnanosheets in the blend matrix of PBAT/PLA resulted in an important gain of mechanical properties of the blend. This result indicates that a very small amount of RGO nanosheets addition in the PBAT/PLA can lead to obtaining materials with superior properties suitable for several industrial applications.

    Palavras-Chave: polymers; graphene; oxides; biodegradation; mechanical tests

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  • IPEN-DOC 27627

    BARTOLOMEI, S.S.; MOURA, E.A.B. ; WIEBECK, H.. Inhibition of flame propagation in nanocomposites with expanded polystyrene recycled clay, gypsum, and titanium dioxide. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 609-618, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_60

    Abstract: The large amount of plastic waste found in the environment, landfills, and dumps boost research into the recycling of polymer materials, which could reduce the amount of polymer discarded. In Brazil, the sector that most consumes polymers is the civil construction that could consume recycled polymerswithout concerns with the properties due to applications of low mechanical exigency. However, for applications in this sector, it is necessary that the materials have some resistance to the propagation of flames. This work discusses the flame retardance in nanocomposites with recycled polystyrene matrix and particles of nanoargila, titanium dioxide, and gypsum. The results of the X-ray diffraction (XRD), differential scanning calorimeter (DSC), field emission scanning electronmicroscopy (FE-SEM), and flammability test. The results showed that glycerol, added during recycling, can plasticize recycled expanded polystyrene while maintaining the flame resistance properties of the material with flame retardant. It can also be concluded that some particles may delay the propagation of the flame in the composite.

    Palavras-Chave: clays; titanium oxides; gypsum; polystyrene; flames

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  • IPEN-DOC 27626

    SANTOS, BIANCA S. ; INACIO, ANDRE L.N. ; BARTOLOMEI, SUELLEN S. ; SILVA, TAISE B.S. ; CARMO, KARINA L.S. ; OLIVEIRA, RENE R. ; MOURA, ESPERIDIANA A.B. . Influence of the reduced graphene oxide incorporation on properties of acrylonitrile butadiene styrene (ABS). In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 599-607, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_59

    Abstract: The purpose of this study was to evaluate the influence of incorporation of the reduced graphene oxide on properties of acrylonitrile butadiene styrene (ABS). The incorporation of 0.5 and 1.5 wt% of RGO into ABS matrix was carried out by melting extrusion process using a twin-screw extruder and injection molding machine. The properties of ABS/RGO nanocomposite samples were investigated by tensile and impact Izod tests, FE-SEM, and XRD analysis. The results showed that the incorporation of small amount of RGO into ABS matrix led to obtaining of polymeric nanocomposite with superior mechanical properties when compared with original properties of ABS matrix.

    Palavras-Chave: graphene; oxides; acrylonitrile; butadiene; styrene; mechanical tests

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  • IPEN-DOC 27625

    TATEI, TATIANE Y. ; FONTES, ERIC H. ; MOREIRA, RENAN P. ; DIAS, FRANCISCO V.; OLIVEIRA, RENE R. ; RANGARI, VIJAYA; MOURA, ESPERIDIANA A.B. . Improvement properties of polypropylene by graphene oxide incorporation. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 581-589, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_57

    Abstract: Due to the remarkable properties of graphene oxide (GO) and its possibility of functionalization,GOhas been used in many applications such as nanocomposites. GO nanosheets have been shown to improve the properties of the polypropylene (PP) matrix, for instance, its strength, gas barrier, thermal, and electrical conductivity. As PP has relatively low cost and varied applications, this work aims to study the changes in its thermal, morphological, and mechanical properties, due to the incorporation of GO in the PP matrix. GO was synthesized from graphite by a modified Hummers method. The nanocomposites PP/GO with 0.1, 0.2, and 0.3 wt% of GO in the PP matrix were obtained using a twin-screw extruder and an injection molding machine via a melt blending process. The nanocomposites PP/GO were characterized by FE-SEM and Izod impact test. In addition, the GO nanosheets were also characterized by Raman spectroscopy, ATR-FTIR, FE-SEM, and XRD, therewith correlation between properties was discussed.

    Palavras-Chave: graphene; oxides; polypropylene; nanocomposites

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  • IPEN-DOC 27624

    MIRANDA, LEILA F. de; BARBOSA, ISABELLA T.F.; MASSON, TEREZINHA J.; MUNHOZ JUNIOR, ANTONIO H.; SILVA, LEONARDO G. de A. e ; GONÇALVES, ALEKSANDRA A.A.. Characterization of hydrogels for release of cosmetic assets containing nanoemulsions of mandellic acid in different concentrations of pseudoboehmite. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 477-489, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_47

    Abstract: Hydrogel is a gel formed by a three-dimensional network of hydrophilic polymers that are used as advanced asset release systems with good biocompatibility. The use of ionizing radiation to obtain hydrogels promotes cross-linking with the concomitant sterilization of the hydrogels. Aiming at the release of the mandelic acid (an active cosmetic), hydrogels were prepared using different concentration of poly(N-vinyl-2-pyrrolidone) (PVP), poly(ethylene glycol) (PEG) and agar containing nanoparticles of the pseudoboehmite, mandelic acid and Palmarosa and Rosa Mosqueta oils nanoemulsions, submitted to irradiation dose of 25 kGy. Hydrogels containing 7.5 wt% PVP showed better absorption, slip, odor results, and those with 10 wt% PVP were found to be inadequate. Nanoemulsions were characterized by acidity, density and optical microscopy; hydrogels samples were put under isothermal dehydration with air entrainment and dehydration was examined as a function of time. The results showed that the composition of hydrogels is stable, and the increase of the concentration of pseudoboehmite in hydrogels sample containing Palmarosa oil suffers less dehydration and those containing the two oils showed an increase in dehydration. The hydrogels obtained with 7.5 wt% of PVP and 3 wt% of pseudoboehmite, Rosa Mosqueta vegetable oil and mandelic acid are most suitable to be used in cosmetic products.

    Palavras-Chave: hydrogels; mandelic acid; pvp; consumer products

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  • IPEN-DOC 27623

    KOMATSU, LUIZ G.H. ; OLIANI, WASHINGTON L. ; OLIVEIRA, CAMILA B. ; RANGARI, VIJAYA K.; PARRA, DUCLERC F. . Application of nanoparticles of ZnO and ZnO-doped-Ag in polymeric blend of HMSPP/SEBS for biocide activity. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 429-435, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_41

    Abstract: In this study, the nanoparticles of Zinc oxide (ZnO) and Zinc oxide doped with Silver (ZnO/Ag) were synthesized in laboratory. The incorporation of these nanoparticles in the blend of high melt strength polypropylene (HMSPP) and styrene– ethylene/butadiene–styrene (SEBS) was carried by melt processing. The obtained materials were evaluated by X-ray diffraction (XRD), Raman Spectroscopy, Differential Scanning Calorimetry (DSC), biocidal tests against the bacteria Escherichia coli and Staphylococcus aureus. The nanoparticles showed size between 150 and 200 nm and spherical form. HMSPP/SEBS/AgNPs/ZnO films incorporated with the nanoparticles have demonstrated biocidal effect against the bacteria E. coli and S. aureus when irradiated at 12.5 kGy.

    Palavras-Chave: zinc oxides; antimicrobial agents; nanoparticles; antibiotics

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  • IPEN-DOC 27622

    SOARES, CARLOS ; SANTANA, JULYANA ; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B. . A comparison between graphene oxide and reduced graphene oxide as reinforcement agents in polypropylene nanocomposite using irradiated polypropylene as compatibilizer. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 385-394, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_36

    Abstract: Graphene is thematerial with the bestmechanical resistance ever encountered. Various types of studies have been carried out on possible applications. The use as a reinforcement in nanocomposites has shown to be a promising field, but some studies indicate that the graphene oxide (GO) and reduced graphene oxide (RGO) have better results as reinforcement, due to the functional groups,which allowa better adhesion with the matrix. This study analyzes the production of polypropylene (PP) nanocomposite comparing the use of graphene oxide (GO) and reduced graphene oxide (RGO) as fillers and irradiated polypropylene as a coupling agent.Atwin-screw extruder and injection molding machine were used to produce the nanocomposite PP reinforced with 0.2 wt% of GO and RGO by melt blending. The GO and RGO were characterized byXRDanalysis.The nanocomposite sampleswere characterized by XRD, SEM, TG, DSC and mechanical test.

    Palavras-Chave: graphene; oxides; polypropylene; nanocomposites; gamma radiation; stresses; tensile properties

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  • IPEN-DOC 27621

    COSTA, ROBSON S. ; MOURA, ESPERIDIANA A.B. . A bibliometric analysis of the strategy and performance measurement of the polymer matrix nanomaterials development scenario globally, and the participation of Brazil. In: LI, JIAN (Ed.); ZHANG, MINGMING (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); IKHMAYIES, SHADIA (Ed.); KALAY, YUNUS E. (Ed.); HWANG, JIANN-YANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); CARPENTER, JOHN S. (Ed.); BROWN, ANDREW D. (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2020. p. 329-342, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-36628-5_31

    Abstract: Extensive studies have been conducted worldwide on the strategy for the development of nanomaterials. One of the known strategies for this has aroused interest in the market is the incorporation of the nanoparticles, extracted from the residues in thematrices of the polymers for the production of environmentally correct nanocomposites. This work presents a survey of the scientific knowledge of nanomaterials of the polymer matrix and a panoramic view of the evolution of these nanomaterials are subject, in order to meet the criteria of sustainable development due to the environmental concerns. This study also intends to use bibliometric tools to database acquisition and analysis of bibliographic reviews for an evaluation of the scenarios in the world on the development of polymeric nanomaterials based on three different classes of polymeric nanocomposites: polymer/clay; polymer/graphene, and polymer/nanocellulose nanocomposites.

    Palavras-Chave: statistical data; nanomaterials; nanocomposites; scientific personnel; knowledge management; polymers

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  • IPEN-DOC 27620

    ABE, ALFREDO ; SILVA, ANTONIO T. e ; GIOVEDI, CLAUDIA; MELO, CAIO; GOMES, DANIEL de S. ; MUNIZ, RAFAEL R.. The IPEN/CNEN contribution to IAEA FUMAC benchmark using modified fuel performance code based on stainless steel as cladding under steady state, transient and accident conditions. In: TECHNICAL MEETING ON MODELLING OF FUEL BEHAVIOUR IN DESIGN BASIS ACCIDENTS AND DESIGN EXTENSION CONDITIONS, May 13-16, 2019, Shenzhen, China. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2020. p. 1-9.

    Abstract: The IPEN/CNEN (Brazil) participated in IAEA Coordinated Research Project on Fuel Modeling in Accident Conditions (FUMAC) among others 18 countries (Argentina, Belgium, Bulgaria, China, Czech Republic, Finland, France, Germany, Hungary, Italy, Japan, Norway, Republic of Korea , Russian Federation , Spain , Sweden , Ukraine and United States of America), which aim was focused in modelling, predicting and improving the understanding of the behaviour of nuclear fuel under accident conditions in order to better understanding and enhanced safety of nuclear fuel. A serie of LOCA (Loss of Coolant Accident) experiments data were made available for the participants to perform simulation using their fuel performance codes and the outcome gives an idea about fuel codes limitation considering LOCA simulation and possible improvement needed in the existing models related to LOCA condition.The IPEN/CNEN (BRAZIL) proposal for FUMAC-CRP was to modify existing fuel performance codes (FRAPCON and FRAPTRAN) considering stainless steel as cladding material and perform a simulation comparing to zircaloy cladding performance under steady state and accident condition. The HALDEN LOCA Experiments (IFA 650-9, IFA-650-10 and IFA-650-11) were selected and modeled to perform the LOCA accident simulation considering the original cladding (zircaloy) and compared to stainless steel cladding.

    Palavras-Chave: design-basis accidents; reactor accident simulation; numerical data; reactor sites; nuclear fuels; stainless steel; cladding; international cooperation

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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

✔ Os filtros disponíveis em Navegar tais como: Coleções, Ano de publicação, Títulos, Assuntos, Autores, Revista, Tipo de publicação são autoexplicativos. O filtro, Autores IPEN apresenta uma relação com os autores vinculados ao IPEN; o ID Autor IPEN diz respeito ao número único de identificação de cada autor constante no RD e sob o qual estão agrupados todos os seus trabalhos independente das variáveis do seu nome; Tipo de acesso diz respeito à acessibilidade do documento, isto é , sujeito as leis de direitos autorais, ID RT apresenta a relação dos relatórios técnicos, restritos para consulta das comunidades indicadas.

A opção Busca avançada utiliza os conectores da lógica boleana, é o melhor recurso para combinar chaves de busca e obter documentos relevantes à sua pesquisa, utilize os filtros apresentados na caixa de seleção para refinar o resultado de busca. Pode-se adicionar vários filtros a uma mesma busca.

Exemplo:

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

Autor: Maprelian

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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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✔ Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).

ATENÇÃO!

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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.