REPOSITÓRIO DIGITAL DA PRODUÇÃO TÉCNICO CIENTÍFICA

 

Conteúdo Temático

(Últimos 5 anos, somente artigos de periód.)

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  • IPEN-DOC 30179

    QUEIROZ, FERNANDA M.; RIBEIRO, GLEICY de L.X.; CASTRO, RENATO S. de; SANTOS, ROGERIO G. dos; VIEIRA, ALEXANDRE ; TERADA, MAYSA; BUGARIN, ALINE de F.S.; ROSSI, WAGNER de ; COSTA, ISOLDA . Study of the effect of nanosecond laser texturing on the corrosion behavior of Ti6Al4V and Ti6Al4V parts produced by powder bed fusion. Materials Performance and Characterization, v. 12, n. 3, p. 341-350, 2023. DOI: 10.1520/MPC20220109

    Abstract: Combining metallic additive manufacturing with laser texturing could be an alternative in obtaining parts with functional hydrophilic surfaces, which improves osteointegration. Careful study of the corrosion behavior of the surfaces obtained is necessary, because the evolution of this phenomenon can influence the osteointegration of the implant, causing the release of metal ions in the body and even the rejection of the component. This study compared the corrosion behavior of laser texturing Ti6Al4V components with components manufactured using laser power bed fusion of the same alloy followed by laser texturing. Their microstructure, roughness, wettability, and electrochemical behavior were analyzed, and different morphologies and microtopographies were observed comparing both samples. The electrochemical tests obtained indicate that Ti6Al4V showed higher corrosion resistance than L-PBF Ti6Al4V after laser texturing. The results suggest that laser texturing can encourage cell proliferation and osseointegration on the surface of Ti6Al4V biomedical implants.

  • IPEN-DOC 30180

    SANTOS, JHONATHA R. dos ; BUENO, PATRICIA; JAKUTIS, JONAS; VICTOR, ALESSANDRO R.; BARRETA, LUIZ F.N.; SBAMPATO, MARIA E.; NERI, JOSE W.; SILVEIRA, CARLOS A.B.; RODRIGUES, NICOLAU A.S.; DESTRO, MARCELO G.. Dysprosium optogalvanic spectroscopy in a hollow cathode lamp. Journal of the Optical Society of America B, v. 40, n. 5, p. 1141-1147, 2023. DOI: 10.1364/JOSAB.482663

    Abstract: This work presents data obtained from optogalvanic spectroscopy (OGS) of dysprosium (Dy) using a commercial hollow cathode lamp. Combining laser beams from two tunable dye lasers, it was possible to identify 13 electronic transitions from excited states of the atom not observed or registered in published papers and the NIST database; these lines were observed between 555–575 nm and 585–615 nm. The study of 13 two-step transitions found in this work complement the available data for the Dy which may support other research or any work using this atom.

  • IPEN-DOC 30178

    SILVA, BRUNO L. da; CARMINATI, SAULO A. ; SOUZA, MATHEUS B.C.; SOARES, LEONARDO C.; LONGO, CLAUDIA; FERNANDEZ, PABLO S.; NOGUEIRA, ANA F.. Photoelectrochemical conversion of glycerol aqueous solution to value-added chemicals using Bi2Fe4O9 as a photoanode. Sustainable Energy and Fuels, v. 7, n. 23, p. 5546-5556, 2023. DOI: 10.1039/d3se01045g

    Abstract: A low-cost, stable and non-toxic Bi2Fe4O9 (BFO) photoanode was used for the first time to promote glycerol aqueous solution photoelectrochemical conversion to hydrogen and value-added chemicals. Photoelectrochemical measurements were performed under AM1.5G irradiation using a three-electrode cell. The best performance was achieved in alkaline medium, where four distinct glycerol oxidation products were detected (glycerate, formate, glycolate and lactate). In neutral medium, no oxidation products were detected. In acidic medium, we observed an improved selectivity, with only glyceraldehyde and dihydroxyacetone as oxidation products. Our results show that the electron–hole recombination, which restricts the efficiency of glycerol conversion, is one of the main shortcomings of BFO. However, its high open circuit potential (OCP) value and several other desirable properties for a good photoelectrocatalyst make it a material worth further research.

  • IPEN-DOC 30177

    MOLDONADO, EDISON P.; SAMAD, RICARDO E. ; ZUFFI, ARMANDO V.F. ; SANTOS, JHONATHA R. dos ; VIEIRA JUNIOR, NILSON D. . Impact of He+N2 concentration on self-modulated laser wakefield acceleration driven by pulses of a few TW. Journal of the Optical Society of America B, v. 40, n. 4, p. C141-C147, 2023. DOI: 10.1364/JOSAB.482305

    Abstract: Laser wakefield electron acceleration with ionization injection has rarely been studied in the low-power, selfmodulated case. We performed simulations of such regimes using a mixture of He and N2 gases and driven by laser pulses with peak powers around 1 TW. Analyses show the generation of electron bunches with an average energy of up to 70 MeV, an energy spread as low as 18%, and an emittance as good as a fraction of a mm mrad. The obtained electron beam parameters lead to several trade-offs as a function of N2 concentration, allowing for many different designs.

  • IPEN-DOC 30197

    IGAMI, MERY P.Z. . Repositórios digitais institucionais: a experiência do IPEN/SP. In: MIRANDA, ANGELICA C.D. (Org.); OLIVEIRA, ADRIANA A. (Org.); QUEIROZ, CLAUDETE F. de (Org.); ARAUJO, LUCIANA D. de (Org.). Repositórios: visão e experiência. Rio de Janeiro, RJ: Fiocruz/Icict, 2023. p. 200-212, v. 1,

    Abstract: Descreve-se a experiência do IPEN, objetivando compartilhar conhecimento e contribuir para o avanço do papel que os Repositórios digitais institucionais podem alcançar. O Instituto de Pesquisas Energéticas e Nucleares - IPEN - é um instituto público federal localizado em São Paulo, cuja missão é produzir conhecimento e tecnologia relacionados com as aplicações das técnicas nucleares e das ciências relacionadas, dedicando-se também à formação de recursos humanos, mediante um programa de Pós-Graduação. O relato diz respeito ao processo de migração da base de dados referencial de produção científica institucional, construída na década de oitenta, para o atual Repositório Digital (RD). A citada base de dados referencial foi organizada segundo padrões internacionais, reunindo e atribuindo um tratamento diferenciado à produção científica da instituição, desde a sua criação. Descreve-se essa organização e os atributos que facilitaram o processo de migração e que se tornaram fatores decisivos para o sucesso da atividade. Para funcionamento do atual RD, foram desenvolvidas funções e acrescentados metadados, além dos tradicionais, os quais se constituem em filtros, a fim de favorecer o controle, o monitoramento, a extração de relatórios e principalmente a interoperabilidade com o Sistema Gerencial Institucional, o SIGEPI. O RD fornece dados em tempo real e em fluxo contínuo, apresenta estatísticas de produtividade para a elaboração de indicadores científicos e informações gerenciais para subsidiar os gestores do IPEN. O RD foi construído dentro dos pressupostos do movimento de Acesso Aberto e, por meio de ações de valor agregado atribuído, tornou-se um instrumento de gestão do capital intelectual institucional. Descreve-se também o planejamento para futuras atividades a serem desenvolvidas com o RD.

  • IPEN-DOC 30176

    MACHADO, MARINA ; TABUTI, F. ; PIAZZOLLA, F. ; MORAES, T. ; ABE, R.; GUIMARAES, R.M.; MIURA, Y.; FUKUYAMA, Y.; FONSECA, F.C. . Steam reforming catalytic layer on anode-supported and metal-supported solid oxide fuel cells for direct ethanol operation. ECS Transactions, v. 111, n. 6, p. 301-311, 2023. DOI: 10.1149/11106.0301ecst

    Abstract: A catalyst based on lanthanum chromite with exsolved metallic ruthenium nanoparticles (LaCrO3-Ru) was applied as a catalytic layer for internal ethanol steam reforming of anode-supported and metal-supported solid oxide fuel cells. The metal support exhibits limited catalytic properties for the ethanol steam reforming reaction. Thus, the LaCrO3-Ru catalysts were optimized for operating temperatures in the 600-700 °C range to promote stable ethanol reforming. The catalytic layer had no significant impact on the electrochemical properties of the fuel cell, and samples with and without the catalytic layer exhibited similar performance in hydrogen. Initial durability tests with LaCrO3-Ru layer have shown that the catalytic layer plays a crucial role in the stability of the metal-supported fuel cell under ethanol.

  • IPEN-DOC 30196

    SILVA, ANA C.K. de S. ; ZAMBONI, CIBELE B. ; SILVA, DALTON G.N. da . X-ray investigation of graphic art / Investigação de arte gráfica por raios X. In: SEVEN INTERNATIONAL MULTIDISCIPLINARY CONGRESS, 3rd, June 1-2, 2023, Online. Proceedings... São José dos Pinhais, PR: Home Publishing Brazil, 2023. DOI: 10.56238/sevenIIImulti2023-195

    Abstract: X-rays produced by electron ionization provide an analytical tool that can assist investigations in the field of Artistic and Cultural Heritage. In this study, the technique of Energy Dispersive X-ray Fluorescence (EDXF) was employed to investigate collections of postcards from the 1960s produced in Brazil, London and Uruguay. The collections belong to private collections and were made available for analysis at the Radiation Spectroscopy and Spectrometry Laboratory of the Institute for Nuclear and Energy Research (IPEN). This technique is non-destructive and allows the identification of chemical elements present in the different chemical formulations used in the printing industries of each country in the process of preparing postcards. This information allows tracing their origin and identifying copies/fakes, which enables their cataloging and registration for exhibition, as well as providing subsidies for conservators and restorers regarding the preservation and storage of these artistic materials.

  • IPEN-DOC 30195

    SILVA, RUBENS C. da; MORAIS, PAULO J.D. de; CARVALHO, ANDRE; ROSSI, WAGNER de ; MOTTA, CLAUDIO C.. Thermophoretic efficiency in the MCVD process: a CFD modeling. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230917

    Abstract: The thermophoretic efficiency in the modified chemical vapour deposition (MCVD) process has been numerically determined under specified conditions of temperature and velocity field in the silica deposition tube. A CFD code was used to solve a steady-state numerical model of the MCVD process. The cumulative efficiency of SiO2 and GeO2 deposition was calculated along the tube length, yielding to a maximum value of 42% and 37 % respectivelly.

  • IPEN-DOC 30194

    ZUFFI, ARMANDO V.F. ; SANTOS, JHONATHA R. dos ; SAMAD, RICARDO E. . Ionization model to estimate the density and temperature of fs-laser-induced plasmas in air. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230914

    Abstract: We present a simple ionization model to assess the density of plasmas created in air by ionization induced by the electric field of ultrashort laser pulses. It calculates the average ionization induced by the laser taking into account the known threshold intensities for each ionic state, the beam spatial profile and the atmospheric composition, estimating the plasma density. The model density predictions are compared to experimental results obtained by a time-resolved Mach-Zehnder-like interferometer, and are also used as entry parameters to evaluate the plasma temperature by the Saha equation.

  • IPEN-DOC 30193

    WETTER, NIKLAUS U. ; VIEIRA, RENATO J.R. ; SILVA, DANILO M. da ; JORGE, KELLY C. ; JIMENEZ-VILLAR, ERNESTO ; GIEHL, JULIA M. ; MIRANDA, ADRIANA R. de ; DIPOLD, JESSICA . Random lasers: review of research activities at IPEN. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFotonIOPC58971.2023.10230975

    Abstract: Random lasers offer advantages such as low-cost fabrication and robustness in harsh environments and have applications in sensing, imaging, communications, and security. Our current research focuses on advanced materials, active control techniques, integration with other photonic structures, and exploration of Anderson localization and polydisperse effects. Coherent feedback in cavity-enhanced random lasers is discussed as means to achieve specific emission characteristics, and emission at 1300 nm is shown for the first time.

  • IPEN-DOC 30192

    FAROOQ, SAJID ; GERMANO, GLEICE ; STANCARI, KLEBER A. ; RAFFAELI, ROCIO; CROCE, MARIA V.; CROCE, ADELA E.; ZEZELL, DENISE M. . A 3D discriminant analysis for hyperspectral FTIR images. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230933

    Abstract: Here, we apply a 3D discriminant analysis approach to analyze FTIR hyperspectral images of normal vs malignant Melanoma (MM) samples for skin cancer diagnosis. For this porpose we used 2 samples, for Normal (49k) and for MM(90k). Our results evidence the outstanding performance with accuracy up to 81% for big data (> 100k).

  • IPEN-DOC 30191

    ROMANO, FERNANDO C. ; WETTER, NIKLAUS U. . Transverse electromagnetic modes simulation and experimental measurement technique for a single stripe laser diode. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230954

    Abstract: A single stripe multimode laser diode software model has been developed. In addition, a method for measuring the transverse electromagnetic modes (TEM) in the RF spectrum through a frequency beating process was also developed. For supporting the TEM readings, a spectrum analyzer was applied and converted the temporal signals to the frequency domain using the fast Fourier transform (FFT) method.

  • IPEN-DOC 30190

    PRADO, FELIPE M. ; SOUZA, PEDRO H.M. de; SILVA, SIDNEY L. da; WETTER, NIKLAUS U. . Photoelastic dispersion coefficient by holographic reconstruction with neural networks and the Fresnel method. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230956

    Abstract: Here we report the characterization of the photoelastic dispersion coefficient using digital holography with two distinct reconstruction methods: one based on the Fresnel method and the other utilizing convolutional neural networks (CNN). The CNN was trained with reconstruction from the Fresnel method and was able to provide reconstructions with an average Mean Squared Error of 0.006.

  • IPEN-DOC 30189

    PRADO, FELIPE M. ; FRANCO, TOMAS J.; WETTER, NIKLAUS U. . Highly-efficient, dual-wavelength Nd:YLF laser emitting at 1314 nm and 1047 nm. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230922

    Abstract: We report a record optical-to-optical efficiency of 43% and a slope efficiency of 48% for a Nd: YLF laser emitting at 1314 nm. The crystal was side-pumped by a VBG-equipped diode emitting at 797 mn, with a peak power of 1545 W. We also report simultaneous dual-wavelength emission, at 1313 nm and 1047 nm.

  • IPEN-DOC 30175

    MALDONADO, EDISON P.; SAMAD, RICARDO E. ; ZUFFI, ARMANDO V.F. ; VIEIRA JUNIOR, NILSON D. . Simulation of self-modulated laser wakefield acceleration using few TW in downramp injection and ionization injection regimes. Applied Optics, v. 62, n. 12, p. 3202-3207, 2023. DOI: 10.1364/AO.477401

    Abstract: Simulations of transitional self-modulated laser wakefield acceleration driven by laser pulses of a few terawatts are discussed, comparing a downramp-based injection regime with an ionization injection regime. We demonstrate that a configuration using an N2 gas target and a laser pulse of ∼75mJ with ∼2TW peak power is a good alternative as a high repetition rate system that produces electrons of many tens of MeV, pC charge, and emittance of the order of 1 mm mrad.

  • IPEN-DOC 30188

    PERES, DANIELLA L. ; FAROOQ, SAJID ; RAFFAELI, ROCIO; CROCE, MARIA V.; CROCE, ADELA E.; ZEZELL, DENISE M. . Identification of basal cell carcinoma skin cancer using FTIR and Machine learning. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230945

    Abstract: Here we applied ATR-FTIR spectroscopy combined with computational modeling based on 3D-discriminant analysis (3D-PCA-QDA). Our results present an exceptional performance of 3D-discriminant algorithms to diagnose BCC skin cancer, indicating the accuracy up to 99%.

  • IPEN-DOC 30187

    BRANDAO, VITORIA M.C. ; SAMAD, RICARDO E. . Development of an Imaging System for an Electron Spectrometer for laser-accelerated electrons. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFotonIOPC58971.2023.10230979

    Abstract: We present the results of an electron spectrometer with an imaging system to determine the energy spectrum of laser accelerated electrons. The spectrometer is composed by a region with a constant magnetic field that deflects relativistic electrons according to their kinetic energy, and a luminescent screen into which the electrons impinge. The imaging system optimizes the collection of the screen luminescence, which is inside a vacuum chamber, and magnifies it, through a window, into a CCD in atmosphere that records the light pattern, from which the energy spectrum is recovered.

  • IPEN-DOC 30186

    FAROOQ, SAJID ; PERES, DANIELLA L. ; CAIXETA, DOUGLAS C.; LIMA, CASSIO; SILVA, ROBINSON S. da; ZEZELL, DENISE M. . Monitoring changes in urine from diabetic rats using ATR-FTIR and Machine Learning. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230957

    Abstract: Here, we aim to better characterize diabetes mellitus (DM) by analyzing 149 urine spectral samples, comprising of diabetes versus healthy control groups employing ATR-FTIR spectroscopy, combined with a 3D discriminant analysis machine learning approach. Our results depict that the model is highly precise with accuracy close to 100%.

  • IPEN-DOC 30174

    ZUFFI, ARMANDO V.F. ; SANTOS, JHONATHA R. dos ; MALDONADO, EDISON P.; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Femtosecond laser-plasma dynamics study by a time-resolved Mach–Zehnder-like interferometer. Applied Optics, v. 62, n. 8, p. C128-C134, 2023. DOI: 10.1364/AO.477395

    Abstract: Side-view density profiles of a laser-induced plasma were measured by a home-built, time-resolved, Mach–Zehnder-like interferometer. Due to the pump-probe femtosecond resolution of the measurements, the plasma dynamics was observed, along with the pump pulse propagation. The effects of impact ionization and recombination were evidenced during the plasma evolution up to hundreds of picoseconds. This measurement system will integrate our laboratory infrastructure as a key tool for diagnosing gas targets and laser-target interaction in laser wakefield acceleration experiments.

  • IPEN-DOC 30185

    DIPOLD, JESSICA ; BORDON, CAMILA D.S.; MAGALHAES, EVELLYN S.; KASSAB, LUCIANA R.P.; JIMENEZ-VILLAR, ERNESTO; WETTER, NIKLAUS U. . Random laser emission in Nd3+ doped tellurite glass. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230929

    Abstract: Random lasers are easier and cheaper to manufacture than regular ones, being made of several materials such as polymers, powders or dyes. Glass random lasers have been rarely studied due to their inhomogeneous broadened emission and low damage threshold. Here, we study Nd 3 +doped Te0 2 -ZnO-Al 2 0 3 glasses with different concentrations of rare-earth doping (4 wt.%, 8 wt.% and 16 wt.%). Emission intensity per pump fluence and fluorescence decay time measurements showed the potential of these glasses for random laser applications in the near-infrared region.

  • IPEN-DOC 30184

    CATARINA, MARCUS V. ; BERECZKI, ALLAN ; WETTER, NIKLAUS U. . Sub-nanosecond microchip oscillator for a MOPA system tailored for tattoo removal. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFOTONIOPC58971.2023.10230921

    Abstract: In this work we study a microchip laser designed to function as an oscillator in a Master-Oscillator Power-Amplifier (MOPA) system targeted for laser tattoo removal. Different configurations of the Nd: YAG resonator were used by changing the output coupler mirror reflectivities and the initial transmission of the Q-switch. The quasi-CW resonator provided 55.4 W of output with 51.31% and 78.2% optical and slope efficiencies, respectively. For Q-switched operation, the best configuration resulted in a peak output power of 3.6 MW with 588 ps pulse width.

  • IPEN-DOC 30183

    BERECZKI, ALLAN ; MENEZES, FELIPE C. de ; WETTER, NIKLAUS U. . Compact, high power CW ring laser resonator. In: INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS; SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, July 31 - August 3, 2023, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2023. DOI: 10.1109/OMN/SBFotonIOPC58971.2023.10230968

    Abstract: We demonstrated the dynamically stable operation of aNd: YAG ring laser with 51.8 W of linearly polarized, continuous output power. The laser was based on laser modules side-pumped by diode bars. The resonator, aimed at single-frequency operation, is a design improvement from a previous work with the resonator length 4.3 times smaller than the previous design, thus resulting in a larger free spectral range, favoring for operation at single-frequency.

  • IPEN-DOC 30173

    MOYA, MURILO T.M.; ARAUJO, LEANDRO G. de ; LOPES, FERNANDO S.; TEIXEIRA, ANTONIO C.S.C.. TiO2 P25 and Kronos vlp 7000 materials activated by simulated solar light for atrazine degradation. International Journal of Chemical Reactor Engineering, v. 21, n. 10, p. 1211-1223, 2023. DOI: 10.1515/ijcre-2022-0186

    Abstract: Photocatalysis-based technologies have been proposed for the treatment of wastewater containing atrazine (ATZ), a persistent and recalcitrant pollutant. This study aims to evaluate and compare the efficiency of TiO2 P25 and TiO2 modified with carbon (C–TiO2 Kronos vlp 7000) in the photocatalytic degradation of ATZ in aqueous systems. The experiments were performed in a tubular photochemical reactor equipped with a compound parabolic collector (CPC) irradiated by simulated solar light. The materials were characterized by X-ray diffraction, infrared spectroscopy, BET specific surface area, and diffuse reflectance spectroscopy. For TiO2 P25, ATZ removals varied in the range 86–100 % after 120 min of irradiation, although the total organic carbon (TOC) analyses indicated that no significant ATZ mineralization occurred (<20 %). C–TiO2 Kronos vlp 7000, on the other hand, was not able to completely remove ATZ after 120 min of irradiation. In this case, pesticide removals were 37–45 % over 120 min, while C–TiO2 performed better with regard to ATZ mineralization, with 38 % TOC removal. Given the low mineralization of atrazine, the intermediate compounds formed were identified for each photocatalytic material.

  • IPEN-DOC 30172

    OLIVEIRA, ELOANA P.R. de ; VICENTE, JOSE G.; OLIVEIRA, RENE R. de ; COUTO, ANTONIO A. . Fatigue behavior effect of shot peening associated to plasma nitriding surface treatment in F138 stainless steel. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 418-418.

    Abstract: Analysis of shot peening associated to plasma nitriding surface layers on austenitic stainless steel are conduced to verify the influence of the surface treatment in fatigue behavior. Shot peening can be used to increase fatigue resistance, due to the surface residual stress induced. Additionally, shot peening can be used as a previous plasma nitriding treatment to improve nitrogen atoms diffusion, increasing the layer hardness, thickness and fatigue resistance [1]. Thus, the aim of the present work is to study the effect of previous shot peening surface treatment in plasma nitrided F138 stainless steel fatigue properties. Specimens treated with plasma nitriding and shot peening associated to plasma nitriding were analyzed in high cycle fatigue tests. Previous shot peening treatment to plasma nitriding promoted a failure in lower strength values than reference specimens, and its similar to plasma nitride specimens. The result can be associated to roughness increase due to shot peening and plasma nitriding treatments, which can influence fatigue behavior as other surficial morphological characteristics of the formed layer [2]. Fracture surface were analyzed by scanning electron microscopy (SEM) and ductile fracture surface was observed in all conditions. In higher load conditions cracks and microcraks were formed on the sides of the specimen.

  • IPEN-DOC 30171

    GUARNIERI, GUILHERME de P.; NERY, JOSE G.; COSENTINO, IVANA C. . Converting waste materials into biomaterials: enriched calcium zeolites synthed from chicken eggshells for hemostatic applications. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 399-399.

    Abstract: Although there is a plethora of 245 different zeolites with different frameworks with unique and unusual topologies of channels and cavities with large applications in the field of industrial catalysis [1], few of them have found systematic biomedical applications, especially for the purpose of hemorrhage control. Hemostasis is a complex biochemical process in which the assembly of substrates, enzymes, protein cofactors and calcium ions on a phospholipid surface accelerates the rate of coagulation. Several inorganic solid matrices have been employed as topic hemostatic agents, and among them zeolites [2]. However, the synthesis of enriched calcium zeolites for the purpose of hemorrhage control and using as raw materials chicken eggshell biomass is an unexplored field of research. We report the data of the synthesis of four calcium zeolites using CaCO3 derivated from chicken eggshell. Thromboelastographic results using the pristine calcium enriched zeolites show that they were able to promote a faster clot formation and a higher maximum clot strength than those of the commercial topical hemostatic agent QuikClot.

  • IPEN-DOC 30170

    SARTORI, MARIANA do N. ; CASTRO, DIONE P. de ; SILVA, LEONARDO G. de A. e . Reuse of textile waste with nano reinforcement for the development of materials incorporated with nanocomposites. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1933-1933.

    Abstract: The use of plastics in Brazil and the world has shown a growing demand due to their qualities, ease of obtaining, and low cost, and, consequently, produces an increase of these plastics in solid urban waste. The destination of these materials, especially in Brazil, is summarized in sending to landfills, incineration and, mechanical and chemical recycling. This study evaluates the possibility of using polyamide textile waste with elastane discarded by the textile industry, as reinforcement for the development of a polymer-clay composite, on a nanometric scale, and develop a recycling route for these materials. In that, the nanocomposite technology adds value to this material. This work used polyamides from textile waste of the industry. These materials were first processed in a compacting machine. Afterward the composites with 1, 2, and 3% in mass of Verde Clara clay/polyamide were prepared in a double screw extruder. The composites were characterized by techniques of X-ray diffraction (XRD), tensile, flexural, impact tests and thermogravimetric analysis (TGA). Results obtained were compared with the properties of the standard samples. As a conclusion of this study, it can be stated that the polyamide textile scraps with elastane can be reused forming nanocomposites with Verde Clara clay. Verde Clara clay in the proportion of 1% already confers gains in the properties of these nanocomposites.

  • IPEN-DOC 30169

    SILVA, CRYSTIAN W.C. da ; OTUBO, LARISSA ; SOUZA, KATIUSSE S. de ; CARBONARI, ARTUR W. ; CORREA, BRUNO S. ; FREITAS, RAFAEL S. de; PASCA, GABRIEL A.; COSTA, CLEIDILANE S.. Comparative local analysis of Ni/Ni3C nanoparticles synthed with oleylamine/oleic acid and oleylamine/palm kernel oil ligand pairs: structural and magnetic properties. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1805-1805.

    Abstract: In recent decades, Ni/Ni3C nanoparticles have been a topic of interest, especially for their catalytic and magnetic properties, promising as electrocatalysis, for example [1]. These systems are usually obtained by chemical methods, in the presence of ligands responsible for controlling their structure and morphology [2]. In this work, we carried out a comparative study of the hyperfine interactions occurring in Ni/Ni3C nanoparticles, synthed by thermal decomposition in the presence of oleylamine/oleic acid and oleylamine/palm kernel oil ligand pairs, at 513 K, for 3 hours. The local analysis was performed using perturbed correlation spectroscopy (PAC) in the temperature range from 30K to 300K, using the 111Cd probe, implanted in the samples by diffusion, during the synthesis. The parameters of the hyperfine interactions were compared to the results obtained by XRD, TEM and magnetization, indicating the obtainment of Ni/Ni3c nanoparticles of the core-shell type, showing a higher Ni3C content, greater distribution and lower saturation magnetization for nanoparticles synthed with palm kernel oil compared to those obtained with oleic acid. In addition, the hyperfine parameters showed the existence of regions with a quadrupole frequency of 24 MHz and a magnetic hyperfine field of 1T in both samples, which may be indicative of carbon-deficient Ni3C regions, predicted in the literature [3].

  • IPEN-DOC 30168

    QUEIROZ, FERNANDA M.; RIBEIRO, GLEICY de L.X.; CASTRO, RENATO S. de; SANTOS, ROGERIO G. dos; BUGARIN, ALINE de F.S. ; TERADA, MAYSA. Influence of the additive manufacturing parameters on the Ti6Al4V microstructure. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1374-1374.

    Abstract: The 3D printing on an industrial scale describe the one more advanced techniques. In the manufacturing process technology the model is created by successively layering material from a digital 3D model. The 3D manufacturing process allows obtaining complex geometry, weight reduction, and customized components. A careful microstructure characterization of the produced components is necessary, since the parameters influence in surface roughness, microhardness and corrosion resistance. Samples of Ti6Al4V built with the same laser speed, hatch distance and layer thickness but different laser power were analyzed. The variation in laser power influenced the roughness and corrosion resistance of the samples.

  • IPEN-DOC 30167

    BUGARIN, ALINE de F.S. ; RIBEIRO, GLEICY de L.X.; CASTRO, RENATO S. de; QUEIROZ, FERNANDA M.; SANTOS, ROGERIO G. dos; TERADA, MAYSA; COSTA, ISOLDA . Influence of texturing parameters on surface modification of UNS S32101 duplex steel. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1373-1373.

    Abstract: The application of laser texturing aims to modify the surface without changing its chemical composition. These alterations can be evaluated through mechanical, physical or chemical tests. Texturing can be applied to improve efficiency in industrial processes, such as the flowability of materials, by applying laser texturing to the internal surfaces of components. This work aims to evaluate the influence of texturing parameters in the flow process of industrial batchers. UNS S32101 lean duplex stainless steel (LDSS) samples were used for the tests. For laser texturing of the surfaces, laser of Yb was used, with a wavelength of 1064 nm (infrared), using the scanning speed of 140 mm/s and pulse duration of 150 ns. Two sets of textured samples were produced: with a frequency of 50 kHz and 2 kHz. In both frequencys, the power(%) was set at 100, 60 and 20. The effect of texturing was analyzed through microstructural characterization with tests of contact angle, roughness and scanning electron microscopy.

  • IPEN-DOC 30166

    BUGARIN, ALINE de F.S. ; VIVEIROS, BARBARA V.G. de ; TERADA, MAYSA; GUILHERME, LUIS H.; NEVES, MAURICIO D.M. das ; COSTA, ISOLDA . Syringe cell method to study the corrosion resistance of the UNS S32101 lean duplex stainless steel welded by the gas tungsten arc welding double fusion (GTAW-DF). In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1178-1178.

    Abstract: This work aims to investigate the corrosion performance of the UNS S32101 lean duplex stainless steel (LDSS) welded by the gas tungsten arc welding double fusion (GTAW-DF). In the study, six welded samples were manufactured with different welding parameters. A Syringe cell was used to characterize the electrochemical behavior of the different welded zones by potentiodynamic polarization tests in NaCl 3,5 % (w.t.) and in a solution of citric acid with addiction of NaCl to simulate the food industry. The results showed that the welding parameters tested significantly affected the corrosion resistance of the LDSS UNS S32101. Besides, a correlation was stablished between microstructure and electrochemical behavior of fusion line (FL), heat affected zone (HAZ) and fusion zone (FZ).

  • IPEN-DOC 30165

    BARROS, REGIS de M.C. de ; NEVES, MAURICIO . Study of residual stresses and fracture toughness in welded and repaired joints using A516 Gr70 steel. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1168-1168.

    Abstract: The properties of welded joints subjected to cyclic loading is an important subject in several áreas[1]. In this scenario, aiming to study this subject, welded joints made of ASTM A 516 GR 70 steel plates, with a thickness of 30.5 mm, welded by the MAG – Metal Active Gas process (20% CO2) with the use of a K-bevel were analyzed. to allow full penetration due to the high thickness [2]. The joints were manufactured with seven welding passes on each side of the chamfer. After welding, one set was subjected to a repair pass, for remelting the surface of the bead using the TIG (Tungsten Inert Gas) process, while another set was subjected to two repair passes. This study aimed to analyze aspects of welded and repaired joints: dimensions (height and width) of the bead, behavior of the residual stress profile measured by X-ray diffraction, Vickers microhardness profile and fatigue crack nucleation with based on ASTM E466 and E606 standards. The results indicated that the greater number of repair passes decreased the compressive residual stress values in the transverse and longitudinal directions, from -350 MPa to 50 MPa. There was greater uniformity in hardness Vickers values (value between 200 and 210 HV) with the use of cord repairs. It was observed that the fracture toughness presented values of 1500 J/mm (without repair) and 900 J/mm (one pass and two repair passes), lower than that found in the material without welding (3500 J/mm). Therefore, as the repair passes were performed, the residual stresses in the weld bead tended to positive values, the hardness tended to stabilize with values of 200 HV due to the increase in the number of repair passes and the fracture toughness decreased in the welded material when compared to the values of the non-welded material. There was no significant difference in fracture toughness between repair passes.

  • IPEN-DOC 30164

    SILVA FILHO, JORGE C.; SILVA, SUELANNY C. da; TAKIISHI, HIDETOSHI ; JANASI, SUZILENE R. ; MARTINEZ, L.G. ; REY, JOSE F.Q.; ESCOTE, MARCIA T.. Influence of reduced graphene oxide on the fabrication to neodymium-iron-boron magnets by mechanical milling. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1131-1131.

    Abstract: The aim of this work was to prepare sintered Nd-Fe-B permanent magnets, following the traditional powder metallurgy route, using reduced graphene oxide (rGO) in the mechanical milling process. Also, it was to study the effect of rGO addition on the magnetic properties of the as-prepared materials. rGO acts as a lubricant and effective milling medium, preventing agglomeration, welding of the particles, and oxidation of the material. The structure and morphology of the composite powders were characterized by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. The magnetic properties of sintered magnets were characterized using a permeameter. The highest values of remanence (Br) and intrinsic coercivity (iHc) values were obtained for the sintered magnet using 0.02 wt% rGO addition, Br = 1.1 T, and iHc = 764.0 kAm-1.

  • IPEN-DOC 30163

    CONCI, MAYCOLN D.; OLIVEIRA, RENE R. ; CENTENO, DANY M.A.; GOLDENSTEIN, HELIO; FARINA, PAULA F. da S.. Evolution of residual stress on AISI D2 tool steel short time tempering. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1117-1117.

    Abstract: Some parameters are used in an attempt to estimate a relationship between time and tempering heat treatment temperature of steels, among which the Hollomon-Jaffe parameter stands out [1]. This work aimed to study the evolution of residual stresses in short-time tempering treatment of AISI D2 tool steel, compared to conventional heat treatment of tempering [2]. The samples were treated in dilatometry for a better control of the thermal processing variables. Microstructural images were generated using optical and scanning electron microscopy, including mapping using EDS. Vickers microhardness measurements were performed. And the measurements of variations in residual stresses in each of the treatment stages and at the end of the treatment cycles were performed by analyzing the X-ray diffraction data using the Sen2Ψ technique [3]. The cycles composed of tempering in short times carried out at 500 ºC or 600 ºC, for 10 seconds or 1 minute, exhibited residual stress states similar to the conventional cycle, with a tendency towards neutrality of the residual stress state and high hardness values. The final residual stresses acquired by the AISI D2 tool steel in the thermal cycles studied, more specifically in the tempering, can be attributed to the precipitation of tempering carbides, which when carried out up to 600 ºC, occurs coherently, or at least partially coherently, to the matrix, producing the neutrality of residual stresses, but when tempering is carried out at 700 ºC, it leads to incoherent precipitation of carbides and matrix recrystallization, leading to an increase in compressive residual stresses and a reduction in the hardness of the material, regardless of the heat treatment time of tempering.

  • IPEN-DOC 30162

    TURCARELLI, TIAGO ; CAMARGO, FABIO de; NEVES, MAURICIO M. das . Effect of EBW process welding parameters on AISI 304L stainless steel bead geometry. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1096-1096.

    Abstract: One important field in the welding researches is the study of the relationship between the welding bead geometry and welding machine parameters. In electron beam welding (EBW) process, the fine controlled parameters enable a detail understand of the weld profile. EBW provides a concentrated beam of energy which can result in a high ratio of weld depth to bead width, which can be called a keyhole. EBW is widely study because of its importance in nuclear and aerospace application, mainly as a result of keyhole bead geometry. The relationship between the welding bead geometry, width root and depth with welding machine parameters is presented in this work by setting beam current and beam deflection frequency. All experiments were carried out on samples of AISI 304L alloy with a thickness (t) = 10 mm, accelerating voltage U = 60 KV, beam current range I = 34 – 43 mA, welding speed v = 480 mm/min, vacuum p < 10-4 mbar, beam deflection width d = 1.2 mm and beam deflection frequency f = 400 / 600 Hz. The weld joint geometry has changed by varying of beam current and beam deflection frequency. The weld penetration was increased by increment of beam current and deflection frequency. Set the frequency at f = 600 Hz and changing the beam current from 34 mA to 39 mA, it was observed that penetration rise from 7.38 mm to 8.46 mm, respectively. On the other hand, when was modified deflection frequency from 400 Hz to 600 Hz, the average welding penetration surged 6.3%. Moreover, with deflection frequency kept in f = 400 Hz, a beam current increment from I = 37 mA to I = 43 mA led to grow the welding penetration from 7.56 to 8.63, respectively. The results of weld width root showed no variation due to an increase of beam current, however applying a change of electron beam deflection frequency from 600 Hz to 400 Hz was verified a slight increase in it. In conclusion, the welding bead geometry is directly affected by varying of current beam and deflection frequency parameters.

  • IPEN-DOC 30161

    SILVA, ALEXIA O.; NUNES, MATHEUS C. dos S.; YOSHIMURA, ELISABETH M.; RODRIGUES JUNIOR, ORLANDO ; TRINDADE, NEILO M.. Thermoluminescence, fluorescence and electron paramagnetic resonance of natural alexandrite. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1016-1016.

    Abstract: Recent studies have proposed the investigation of alexandrite mineral (BeAl2O4:Cr3+) as a potential luminescent dosimeter. Despite this, in-depth studies of defects and luminescent centers in alexandrite were not investigated. It is proposed to characterize the thermoluminescence (TL) emission spectra, fluorescence (FL) and electron paramagnetic resonance (EPR) of alexandrite. TL dosimeters, when stimulated by thermal energy, emit light proportional to the dose of ionizing radiation previously absorbed. The emitted wavelength can be measured through thermoluminescence emission spectra. On the other hand, EPR and FL provides additional information about mineral structure, enabling the study of the effects of ionizing radiation on the sample. For TL, the samples were irradiated with Xrays and measured by Lumi22 homemade system. EPR measurements were carried out using a Bruker EMXplus spectrometer operating in the X-band at room temperature, 2 mW microwave power, 100 kHz modulation frequency and 0.25 mT modulation amplitude. The FL spectra were measured using the Duetta spectrofluorometer, with a 75 W xenon arc lamp included. The data was collected by scanning excitation wavelengths in 360-480 nm and recording emission in the wavelength range of 670-740 nm. Preliminary results indicate that the TL emission spectra presented two peaks, at ~80°C and ~175°C, with emission centered between 600 nm – 700 nm, related to Fe3+ and Cr3+, also detected by EPR. The FL spectra showed two signals: an emission centered at 680 nm (Cr3+ in inversion center), and at 700 nm (Cr3+ in mirror symmetry). The results of all techniques used in this work suggest that emissions are correlated to Cr3+ and Fe3+ ions.

  • IPEN-DOC 30160

    SILVA, BARBARA P.G. ; OTUBO, LARISSA . The influence of PVP molecular weight in the synthesis of silver nanowires using a salt-assisted polyol method. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 877-877.

    Abstract: In the last decades, the demand for new materials to be used in electronic devices has increased. Among the materials that can be used in transparent conductive films (TCFs), are the silver nanowires (AgNWs). This class of material, when supported in glass or PET, e.g., has good conductivity, thermal and mechanical properties and also high transparency. In this work, the AgNWs were synthesized using the polyol method assisted by a salt and the influence of molecular weight of the capping agent polyvinylpyrrolidone (PVP) in the morphology and structure of Ag crystals was investigated. Different molecular weight of PVP (40 K, 120 K, 360 K and 1300 K MW) was used in the synthesis. The surface morphology of the products was observed by scanning electron microscopy and atomic force microscopy. The phase composition and structure were analyzed by X-ray diffraction (XRD) and the XRD patterns diffraction peaks correspond with the face-centered-cubic (fcc) crystalline phase of silver. Transmission electron microscopy was used to analyze the crystal structure, and UV-visible spectroscopy was used to follow the formation of Ag structures. The results indicate that PVP and its chain length have an important role in the formation of silver nanocrystals due to the adsorption and steric effects [1] and as high is the molecular weight of PVP, longer and thinner are the AgNWs as observed by other authors [2]. Different morphologies were obtained when changing the size of PVP chain. For smaller MW of PVP, particles and short wires were formed. Increasing the MW, nanorods and pyramidal particles were formed, and finally, forming nanowires when using the highest MW PVP of the experiments.Improving the aspect ratio of silver nanowires is important to construct TCFs, since the conductivity and transparency properties are improved when they are thinner and longer.

  • IPEN-DOC 30159

    BENTO, RODRIGO T. ; ABE, IGOR Y.; CORREA, OLANDIR V. ; PILLIS, MARINA F. . Raman spectroscopy applied on the structural characterization of TiO2/expanded graphite films. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 707-707.

    Abstract: Photocatalytic heterojunctions obtained from the use of titanium dioxide (TiO2) and carbon based materials are a promising way for the efficient water treatment [1]. The structural properties of the composite photocatalysts are an important characteristic that can influence their photocatalytic behavior [2]. Here, TiO2/expanded graphite (TiO2-EG) films were synthetized by sol-gel and deposited on borosilicate glass substrates by airbrush spray coating method at room temperature. Then, the hybrid films were heat treated at 350, 450 and 550 °C. Raman spectroscopy technique was applied to evaluate the effect of carbon amount and temperature on the structural properties of the films. The films heat treated at 350 °C exhibited a characteristic profile of amorphous material. Raman spectra of composite films heat treated at 450 and 550 °C showed well-defined peaks that can be attributed to anatase-TiO2phase. No peaks related to the rutile or other phases were observed. The investigation revealed that the G and 2D bands present a slight shift, as well as asymmetry, as the carbon content and heat treatment temperature increase – behavior that may be associated with the formation of the semiconductor-C heterojunction. Peaks deconvolution process demonstrated the presence of a second signal not found in the pure films. This effect may indicate a reduction of sp2 domains after the formation of semiconductor-C heterojunction, mainly due to the removal of oxygenated groups during heat treatment, and consequent Ti-C / Ti-O-C bonds formation [3]. The results suggested that the carbon amount and the temperature of heat treatment have great influence on the TiO2 -EG structural properties, which may contribute to the improvement of the photocatalytic activity of the composite films under visible light.

  • IPEN-DOC 30158

    ROSERO, WILMMER A.A. ; BARBEZAN, ANGELICA B. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Development of radioactive nanoparticles functionalized with gum arabic to be used in nanobrachytherapy. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 553-553.

    Abstract: The development of new materials emerges as an alternative to the treatment of cancer, from the combination of nanotechnology and brachytherapy a new area of research was born, Nanobrachytherapy, which through the properties of nanometric materials can achieve better results in the fight against cancer. The objective of this work is classified as radiotherapy, which consists of the use of ionizing radiation to destroy or inhibit the growth of abnormal cells that form a tumor. [1] The ability to integrate NPsAu into biological systems is due to the nanometric dimensions of NPsAu probes which facilitate their incorporation into biological systems, as well as their bioconjugation and non-cytotoxic potential. [2] Taking into account the previous objective, gold was selected as the base element for obtaining nanometric systems, which due to its chemical richness and especially due to the intrinsic properties of one of its radioisotopes, which would allow us in theory to meet the stated objective. . Initially, it was based on the knowledge of the literature, and non-radioactive nanometric systems were obtained, and after a series of stability, characterization and application tests, the radioactive nanometric systems were obtained. Working with radioactive systems posed a great challenge, and up to now it presents us with situations to solve, but we have managed to create a methodology for obtaining, characterizing and applying radioactive gold nanoparticles, and also obtaining positive results from their application.

  • IPEN-DOC 30157

    TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; NOGUEIRA, THUANY C. ; ROSERO, WILMMER A.A. ; VIEIRA, JOSE M. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Possible molds for a new brachytherapy source for spinal and intracranial cancer. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 461-461.

    Abstract: Central Nervous System (CNS) cancer is the 18th most incident cancer in the world, according to the World Health Organization (WHO), and in 2020, in Brazil, it represented 2.5% of all new cancer deaths [1]. Brachytherapy is a type of radiotherapy that positions the radioactive source close to (or in contact with) the tumor. Thus, the targeted region receives most of the dose, protecting the healthy tissues adjacent to the tumor. A promising radioactive source for use in brachytherapy for the treatment of CNS cancer is phosphorus-32 in a polymeric substrate. This source has been prominent as a minimally invasive treatment for craniopharyngiomas and in the treatment of metastatic bone diseases in general [2]. To produce such a source, it is necessary to search for possible molds that can conform the polymeric material into the desired format. Several tests were carried out to determine the best mold for the radioactive source manufacture. Different materials were tested to observe if the mold material would react with the source's components, silicone rubber mixed with orthophosphoric acid. In order to be considered a possible mold, the mixture should cure; if the cure did not concretize, the mold would be descarted. It was concluded that polystyrene (PS) obtained the best result, due to the ease of unmold after the resin curing process.

  • IPEN-DOC 30150

    CARVALHO, JOAO V.M.S. ; SILVA, ROGERIO M.V.; CALDAS, LINDA V.E. . Validation of a radiotherapy sector with an END-TO-END test in an anthropomorphic phantom for radiosurgery from a 3D printer. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 4th, October 16-20, 2023, Valencia, Spain. Abstract... Valencia, Spain: ISIRYM, 2023. p. 76.

  • IPEN-DOC 30156

    GARCIA, JOAO I.M.M.; GOMES, ANDERSON M.; ZAMBUZZI, WILLIAN F.; ICHIKAWA, RODRIGO U. ; SAEKI, MARGARIDA J.. Influence of temperature on obtaining apatites by sol- gel method. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 434-434.

    Abstract: Calcium phosphate-based ceramics (apatites) are synthetic materials that have a chemical composition similar to bone tissue, which makes them interesting to use as biomaterials [1]. In this work, the apatite precursor sols at concentrations of 0.7 mol/L and 1.4 mol/L are prepared by dissolving calcium nitrate and phosphorus pentoxide in ethanol. The sols are kept at rest for 24 hours for hydrolysis (gelatinization) under room temperature and humidity. After hydrolysis, the resulting gels are dried at 80°C to remove the organic solvent and then calcined under different temperatures (from 500°C to 1200°C, with increments of 100°C) for 8h [2]. The X-ray diffraction analysis of the samples by the Rietveld method indicates that the samples are composed of monoclinic and hexagonal hydroxyapatite (HAp), the former being predominant, and calcium β-triphosphate (TCP)[3] . For the material started from the sol with a concentration of 0.7 mol/L, the hydroxyapatite fraction increases from 28.8% to 66.5% when the calcination temperature increases from 500°C to 800°C. Above this temperature, the fraction of this phase decreases. With a concentration of 1.4 mol/L, the hydroxyapatite fraction decreases from 88.2% to 19.5% progressively with increasing temperature from 500°C to 1200°C. The micrographs revealed the formation of particulate but porous materials that agglomerate without sintering up to a temperature of 900°C, from where the formation of sintered and dense agglomerates is observed. The results of the EDX analysis showed a Ca/P molar ratio of around 1.5 for all materials. The cytotoxicity assay, using pre-osteoblast cells (MC3T3-E1, Subclone 4) by non-direct contact of 24h, showed that cell viability and adhesion did not differ from those of the control. A decrease in viability and adhesion was observed for samples prepared at a concentration of 0.7 mol/L and calcined at temperatures above 900°C.

  • IPEN-DOC 30155

    LOURENCO, LARISSA R.; BORGES, ROGER; CARASTAN, DANILO J.; MATHOR, MONICA B. ; MARCHI, JULIANA. Chitosan hydrogel containing bioactive glass aiming at 3D printing for tissue engineering. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 349-349.

    Abstract: 3D printing is a rising processing technique in tissue engineering due to high reproducibility and the possibility of complex or even patient-specific models. Chitosan is a promising biomaterial for both 3D printing and tissue engineering, because of its biocompatibility, rheological properties, biodegradability, and cost-effectiveness. Bioactive glasses can help the regeneration of different biological tissues and act as reinforcement for chitosan matrix. In this work, chitosan hydrogels were produced with different concentrations of 58S bioactive glass (0.5 up to 5%wt). For the rheological characterization, frequency, and recovery experiments were carried out. Printability and shape fidelity were evaluated during the 3D printing process. Indirect cytotoxicity assay using Balb/c 3T3 cells was performed to evaluate the biological properties of the scaffolds. The presence of the glass maintained the viscosity properties and increased the recovery percentage. All materials formed filaments and allowed printing with suitable form maintenance. Biological experiments showed high cell viability for all 3D scaffolds, even though a reduction was observed for higher glass concentrations. The results indicate that the studied materials are printable and potentially recommended for tissue engineering applications.

  • IPEN-DOC 30154

    QUEIROZ, CARLOS A. da S. . Preparation of lanthanum acetate from a mixed rare earths concentrate. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1153-1153.

    Abstract: A simple and economical chemical process to obtaining lanthanum acetate of high purity was studied. The raw material in the form of mixed rare earths carbonate 24% La2O3 comes from commercial Brazilian monazite. It is used the technique of strong cationic exchange resin, proper to water treatment to the lanthanum''s fractionation and it is achieved a purity of 99.9% La2O3 and yield greater than or equal 90%, with the elution of rare earths by EDTA solution at pH 4.0. The complex of EDTA-La is transformed in La2O3 , subsequently the lanthanum oxide is dissolved in acetic acid to obtain the cerium acetate. The solid salt then is characterized via chemical analysis, thermal analysis, X ray diffraction, infrared spectroscopy and mass spectrometry to certify the lanthanum acetate purity. The analytical data collected allowed to conclude that the stechiometric formula for the compound is La (CH3COO)3.1.5 H2O.

  • IPEN-DOC 30153

    LOBO, RAQUEL de M. ; CASTAGNET, MARIANO ; MIRANDA, CARLOS A. de J. ; FALOPPA, ALTAIR A. ; LIMA, JOSE R. de ; MATTAR NETO, MIGUEL ; PEREIRA, LETICIA dos S. ; ANDRADE, ARNALDO H.P. de . Correlations of mechanical properties by SPT (Small Punch Test) and conventional tensile test for Al 6061 – T6. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1084-1084.

    Abstract: The Small Punch Test (SPT) was development by nuclear industries to analyses mechanical properties of irradiated materials principally by small volume of the samples. This technique intend to evaluate the materials behavior during the time life of nuclear reactors, where yours properties changed by irradiation intensity and exposition time. It is considered an almost ¨non-destructive” method [2] due to small sample volume and its applications are spreading for use in situations where conventional methods do not apply. SPT consists of pressing a sphere, with a diameter equal to 2.5 mm, in a miniaturized sample of circular geometry (diameter d = 8 mm and thickness about 0.5 mm)[1], which has fixed edges, tested in conventional mechanical testing machines with the aid of a device developed for their achievement. In this work, mechanical properties of aluminum (Al 6061-T6) were abstained by two different methods: conventional tensile test and the small punch test (SPT). The SPT results depends on graph interpretations and discussions take place at now. Correlations of results guide us in choosing the most appropriated method for interpreting the force x displacement graph from SPT.

  • IPEN-DOC 30149

    NOGUEIRA, THUANY ; TALACIMON, CRISTHIAN ; TEODORO, LARA ; RIGO, MARIA ; RODRIGUES, PRISCILA ; ANGELOCCI, LUCAS ; NOVAES, HAMONA ; ZEITUNI, CARLOS ; ROSTELATO, MARIA . Thermoluminescent dosimetry planning through MNCP. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 4th, October 16-20, 2023, Valencia, Spain. Abstract... Valencia, Spain: ISIRYM, 2023. p. 190.

  • IPEN-DOC 30152

    PEREIRA, MARIA da C.C. ; MADI FILHO, TUFIC ; BERRETTA, JOSE R. ; ALVES, JOAO P. da S. . Response of CsI:Pb scintillator crystal to neutron radiation. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1014-1014.

    Abstract: The helium-3 world crisis requires a development of new methods of neutron detection to replace commonly used 3He proportional counters. In the past decades, great effort was made to developed efficient and fast scintillators to detect radiation.[1] These detectors should, then, be carefully characterized both experimentally and by means of advanced simulation code. Ideally, the detector should have the capability to separate neutron and gamma induced events either by amplitude or through pulse shape differences. As neutron sources also generate gamma radiation, which can interfere with the measurement, it is necessary that the detector be able to discriminate the presence of such radiation. Considerable progress has been achieved to develop new inorganic scintillators, in particular increasing the light output and decreasing the decay time by optimized doping. Crystals may be found to suit neutron detection. In this report, we will present the results of the study of lead doped cesium iodide crystals (CsI:Pb) grown in our laboratory, using the vertical Bridgman technique. The concentration of the lead doping element (Pb) was studied in the range 5x10-4M to 10-2M. The crystals grown were subjected to annealing (heat treatment). In this procedure, vacuum of 10-6 mbar and continuous temperature of 350°C, for 24 hours, were employed. In response to neutron radiation, an AmBe source with energy range of 1 MeV to 12 MeV was used. The activity of the AmBe source was 1Ci Am. The fluency was 2.6 x 106 neutrons/second. The operating voltage of the photomultiplier tube was 1300 V; the accumulation time in the counting process was 600 s and 1800 s. The scintillator crystals used were cut with dimensions of 20 mm diameter and 10 mm height. The Monte Carlo method was used to determine the neutron flux arriving in the detector and the calculated values were obtained by means of MCNP code.

  • IPEN-DOC 30151

    OLIVEIRA, RAPHAEL A.M.P. de; TRINDADE, FABIANE J.; FLORIO, DANIEL Z. de; FONSECA, FABIO C. ; ESPOSITO, VINCENZO; FERLAUTO, ANDRE S.. Effects of La content in ceria-lanthana thin films prepared by pulsed laser deposition. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 810-810.

    Abstract: Solid oxide electrochemical reactors are a promising alternative for challenging chemical reactions, such as oxidative coupling of methane (OCM)[1], which convert methane to C2+products. Cerium oxide is a commonly studied oxide membrane material for its high ionic conductivity in the temperature range ideal for conversion reactions (600-900°C), particularly when doped with rare earth cations like Gd, Sm, or La. Recent studies have shown La2Ce2O7as a promising OCM catalyst[2]. This study investigates the structural properties of LaxCe(1-x)O2(1-x/2)thin films, prepared using pulsed laser deposition, with varying stoichiometry. XRD results indicate textured film growth with preferential [100] orientation of cubic crystalline fluorite for low La content (x≤0.5), while x>0.5 had a random orientation. La doping expanded the fluorite structure, increasing lattice parameters from 5.42 Å for x=0 to 5.69 Å for x=0.7. UV-Raman spectroscopy showed that La content x=10 caused a more pronounced balance between Ce4+and Ce3+than pure ceria samples. Impedance revealed a direct relationship between La content and resistance, indicating lower resistance with lower La content. These findings could lead to using Ce-La oxides thin films as catalysts for OCM in electrochemical reactors based on ceria.

  • IPEN-DOC 30130

    ANTONIO, PATRICIA L. ; SILVEIRA, IURY S. ; CALDAS, LINDA V.E. . Thermoluminescence and phototransferred thermoluminescence of radiation dosimeters:: analysis of the effect of UV light for transfer of charges from deep traps. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 4th, October 16-20, 2023, Valencia, Spain. Abstract... Valencia, Spain: ISIRYM, 2023. p. 123.

  • IPEN-DOC 30129

    DIAS, F.S. ; GIOVANNI, D.N.S. ; POTIENS JUNIOR, A.J. ; RODRIGUES JUNIOR, O. ; POTIENS, M.P.A. ; ZAMBONI, C.B. . Study on the radiation exposure of Portable X-ray Fluorescence. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 4th, October 16-20, 2023, Valencia, Spain. Abstract... Valencia, Spain: ISIRYM, 2023. p. 107.

  • IPEN-DOC 30148

    SA, MARCELO C. de ; CALVO, WILSON P. ; SOMESSARI, SAMIR L. . Regulatory requirements and economic feasibility for developing a mobile SPECT/CT unit with radiopharmacy facilities. In: INTERNATIONAL SYMPOSIUM ON TRENDS IN RADIOPHARMACEUTICALS, April 17-21, 2023, Vienna, Austria. Abstract... Vienna, Austria: International Atomic Energy Agency - IAEA, 2023. p. 168-168.

    Abstract: Brazil has been facing great challenges related to the public health care system, not being able to manage the high national demand for diagnostic imaging tests, therefore avoiding the possibility of an early diagnosis for oncological and cardiovascular diseases. An important medical specialty for providing an early and accurate diagnosis is Nuclear Medicine. Early diagnosis is crucial for health professionals to make decisions that enable more effective treatments and improve the chances of cure. Due to the irreversible damages caused to patient’s health resulting of delay in diagnosis, this research project carried out at Nuclear and Energy Research Institute (IPEN/CNEN), together private companies and associated institutions, focus on regulatory requirements and economic feasibility for developing a mobile unit with hybrid Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) equipment and radiopharmaceuticals facilities for radiolabeling reagents kits with technetium-99m. A mobile SPECT/CT unit with adequate radiopharmacy facilities will be an excellent innovative solution to support Brazilian public hospitals to address the demand for diagnostic imaging tests. This mobile unit could provide health care in isolated areas or even big cities where there are shortage of health resources and high mortality rate for cancer and heart disease.

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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

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

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!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

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.