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  • IPEN-DOC 26130

    ISIDORO, ROBERTA A. ; SANTOS, GABRIEL S. dos; FONSECA, FABIO C. . CoNi/C electrocatalysts for alkaline fuel cell. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 228-228.

    Abstract: Solid alkaline fuel cell (SAFC) has been studied as possible alternatives in the production of electricity for portable and stationary applications. The oxygen reduction reaction (ORR) is key electrochemical processes, because his low kinetics decreases system efficiency. The main progresses in the cathodic side have been related to the development and improvement of activity and stability. In this way, non precious material has been studied, in the last years. Cobalt oxides have been reported to exhibit good performance for ORR. However, cobalt bimetallic can be more eficient catalysts for ORR, especially for its bifunctional function. Some Ni-based electrocatalysts have shown relevant good results for ORR in four-electron pathway. Song et al. Showed, for example, that Ni addition into Ag-based electrocatalysts for ORR decreases the ORR overpotential, while an increasing in the limiting current density is observed. In this way, a bimetallic CoNi/ C was produced to be used as a cathode in alkaline fuel cell.

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  • IPEN-DOC 26129

    QUEIROZ, FERNANDA M.; ARAUJO, JOAO V.S. ; TERADA, MAYSA; LAMAKA, SVIATLANA; COSTA, ISOLDA ; MELO, HERCILIO G. de. Microstructural characterization and corrosion behavior of a commercial friction stir welded AA2024-T3. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1199-1199.

    Abstract: Friction Stir Welding (FSW) arises as a great development by removing rivets, fasteners and lap joints areas, consequently, decreasing the aircraft weight. However, during the welding process, the plastic deformation and heat generation at the joint and surrounding areas lead to three distinct microstructural zones, namely, nugget or stir zone (SZ), thermo-mechanically affected zone (TMAZ), heat affected zone (HAZ), besides the base metal (BM). In these zones the microstructure of the material can be profoundly modified and localized corrosion phenomena can be more easily developed, which can be enhanced by local galvanic coupling due to changes in the microstructure as grain refinement and recrystallization, changes in the grain boundaries, dissolution and precipitation of hardening precipitates and dispersóides. In the present work, a commercial friction stir welded AA2024-T3 had its microstructure characterized by Electron Backscatter Diffraction (EBSD) technique and optical microscopy (OM). The corrosion behavior was investigated by exfoliation corrosion (EXCO) test and the intergranular corrosion susceptibility according to ASTM G110-97. After all tests, the samples were observed by scanning electron microscopy (SEM). EBSD results revealed the evolution of microstructure as a result of FSW. The base metal showed elongated grains along the rolling direction with a pancake-like non-recrystallized structure. The SZ undergone dynamic recrystallization showing finer equiaxed grains as a result of a significant plastic deformation and heating during the welding process. The TMAZ of the advancing side showed recrystallized finer grains, while the TMAZ of the retreating side showed coarse grains. Finally, the HAZ of both advancing and retreating sides showed grains typically elongated caused by the thermal input. The EXCO and intergranular tests showed a more intense attack in the TMAZ of the retreating side in agreement with the corrosion morphology observed by SEM.

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  • IPEN-DOC 26128

    SILVA, SIRLANE G. ; FONTES, ERIC H. ; SILVA, JULIO C.M. ; ASSUMPÇAO, MONICA H.M.T.; OLIVEIRA NETO, ALMIR ; LINARDI, MARCELO . Fuel cell and electrochemical studies of the ethanol electro-oxidation in alkaline media using PtAuIr/C as anodes. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 387-387.

    Abstract: The use of fossil fuels has resulted in an increase of CO2 concentration in the atmosphere . It is well known that CO2 emission from fossil fuels is one of the principals responsible for the greenhouse effect. Taking these aspects into account,fuel cells might bean excelente alternative to the current energy generation as a clean and eficiente power source. In this context, alkaline fuel cells have attracted worldwide attention due to its promise to produce clean energy with high efficiency [1], thus direct etanol fuel cell could offer an alternative for electrical energy generation. In this work, ethanol electrooxidation reaction was investigated considering conventional electrochemical experiments in alkaline media, direct ethanol fuel cell (DEFC), and in situ ATRFTIR. The working electrode/anodes were composed of monometallic Pt/C, Au/C, Ir/C, and trimetallic PtAuIr/C nanoparticles with atomic Pt/Au/Ir ratios of 40:50:10, 50:40:10, 60:30:10, 70:20:10, and 80:10:10. X-ray diffraction (XRD) suggests PtAuIr/C alloy formation, and according to transmission electron micrographs, the mean particle sizes are from 4 to 6 nm for all catalyst compositions. PtAuIr/C 40:50:10 showed the highest catalytic activity for ethanol electro-oxidation in the electrochemical experiments; using this material, the peak current density from ethanol electro-oxidation on cyclic voltammetry experimente was 50 Ma per g of Pt, 3.5 times higher than that observed with Pt/C. The fuel cell performance was superior using all PtAuIr/C compositions than using Pt/C. Au/C and Ir/C presented very poor catalytic activity toward etanol electro-oxidation. The improved results obtained using PtAuIr/C might be related to the OHads species formed at low overpotential on Ir and to the decrease on adsorption energy of poisoning intermediates on Pt sites, promoted by Au.

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  • IPEN-DOC 26127

    MAGNANI, MARINA; GONÇALVES, HAROLDO M.; COSTA, ISOLDA ; BENEDETTI, ASSIS V.; FUGIVARA, CECILIO S.. Microstructural and electrochemical characterization of Friction Stir Welded aluminum alloys. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1191-1191.

    Abstract: Aluminum alloys of 2000 and 7000 series are extensively used in aircraft structures. However, these classes of aluminum alloys are difficult to join by conventional fusion welding techniques because the dendritic structure formed in the fusion zone can seriously compromise the mechanical and corrosion resistance properties of the joint. Friction Stir Welding (FSW) is attractive for joining high strength aluminum alloys since there is far lower heat input during the process compared with conventional welding methods. Frictional heat causes the metal to soften and allows the tool to traverse along the joint line. The FSW process generates three distinct microstructural zones: the nugget, the thermomechanically affected zone and the heat-affected zone. These microstructural modifications generally interfere in the performance of the corrosion resistance of welded alloys. In the present study, FSW was used to join two dissimilar aluminum alloys, AA2024-T3 and AA7475-T651 and the effect of this process on the corrosion resistance of the welded joints and on the microstructure of the alloys was evaluated. Microstructural characterization was carried out by optical microscopy, scanning electron microscopy and atomic force microscopy. The weld zone regions showed significant microstructural changes. Electrochemical impedance spectroscopy and Electrochemical noise measurements were used to evaluate the corrosion resistance of the different zones of the weld in NaCl solution. The electrochemical results showed that the corrosion behavior of the aluminum alloy is dominated by the electrochemical activity within the intermetallics (IMs). The weld zone regions containing copper IMs have a more noble character than the regions containing Zn and Mg IMs. Therefore, the results showed an increased susceptibility of welded joints to these forms of corrosion in comparison to the unaffected base metal by a more severe attack related to AA7475 alloy.

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  • IPEN-DOC 26126

    REIS, SHIRLEY L. dos ; CARVALHO, SABRINA G. de M. ; MUCCILLO, ELIANA N. dos S. ; MUCCILLO, REGINALDO . Sintering under AC electric field of samarium doped ceria. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1064-1064.

    Abstract: Samarium doped ceria (SDC) is a high oxygen-ion conductor compound with application in solid oxide fuel cells operating at intermediate temperatures (500-700ºC). Polycrystalline SDC exhibits low sinterability, requiring high temperatures to achieve full densification under conventional sintering. Flash sintering is a recently developed method in which ceramic compacts may be sintered at lower temperatures and shorter times than those under conventional sintering. It consists in applying an electric field to a green compact, either during heating or at a fixed temperature up to the occurrence of an electric current pulse. In this study, samarium doped ceria (Ce0.8Sm0.2O1.9) was sintered by applying AC electric field at a fixed frequency of 1.0 kHz to the specimen during heating (dynamic sintering) or during a fixed temperature (isothermal). The influence of sintering on densification, microstructure and ionic conductivity was investigated. Similar density values were obtained for specimens sintered at 800ºC (dynamic) and 1100ºC (isothermal).

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  • IPEN-DOC 26125

    PIERETTI, EURICO F. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. ; RAMANATHAN, LALGUDI V. . Electrochemical evaluation of the AISI 316 stainless steel coated by Nb2O5 thin films. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1465-1465.

    Abstract: Great number of metallic engineering materials form passive films on their surfaces and, therefore, are prone to localized corrosion, usually characterized by the occurrence of pits [1,2]. The improvement of surface properties is a requirement for the metallic components used, for example, in petrochemical industry, in fuel cells, and in nuclear plants. The goal of this work was to investigate the influence of Nb2O5 films deposited by DC magnetron sputtering during 15, 30 and 50 minutes on the electrochemical behavior of the AISI 316 austenitic stainless steel. The corrosion resistance was evaluated by monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and linear potentiodynamic polarization (LP) on an electrolyte composed of 0.1 M H2SO4 in water at 25 °C. Electrochemical tests showed that the coated specimens presented a more capacitive behavior, and were less susceptible to corrosion than specimens without Nb2O5 coatings. The OCP for coated samples at 50 min had the most inferior values. Similar results were obtained by Pillis et al. [3] for Nb2O5 coatings at 15 min and 30 min in NaCl solution. These results suggest that the obtained films have a protective behavior and can be used to avoid the degradation of the AISI 316 austenitic stainless steel in aggressive environments containing sulfur ions.

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  • IPEN-DOC 26124

    PIERETTI, EURICO ; CORREA, OLANDIR V. ; PILLIS, MARINA F. ; NEVES, MAURICIO M. das . Corrosion evaluation of an optical fiber laser treated stainless steel for biomedical applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 604-604.

    Abstract: The implant manufacturing process includes marking the final devices for their identification, long-term quality control and traceability. Marking is carried out after cleaning and prior to sterilization. These marks eventually can concentrate stress leading to premature failure. The marked areas are defective regions that affect the oxide layer formed on the biomaterials used for implants favoring the onset of various corrosion forms, such as pitting, crevice or fatigue [1, 2]. This study aims to evaluate the effect of an Yb optical fiber laser marking process on the localized corrosion resistance of the austenitic stainless steel ISO 5832-1 samples. This is one of the most used materials for implants manufacturing. The electrochemical behavior of the marked areas obtained by this method was evaluated in a phosphate buffered solution (PBS) with pH of 7.4 and the results were compared with non treated samples. All tested surfaces were prepared according to the recommendations for clinical use. For localized corrosion resistance evaluation, electrochemical tests as monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and cyclic potentiodynamic polarization measurements were performed. The results showed that the laser marks affects the protector characteristics of the biomaterial’s passive film. Lower pitting resistance was associated to the laser marked areas, because of its roughness changes.

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  • IPEN-DOC 26123

    MUCCILLO, ELIANA N. dos S. ; GROSSO, ROBSON L. ; MUCHE, DERECK N.; CASTRO, RICARDO H.. Nanostructured scandia stabilized zirconia consolidated by high-pressure spark plasma sintering. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 54-54.

    Abstract: Scandia-stabilized zirconia, ScSZ, is an oxide-ion conductor with high ionic conductivity at relatively low temperatures (about 500 ºC). The consolidation of this ionic conductor requires high temperatures to achieve high densification, due to its low sinterability. Moreover, ScSZ exhibits a complex phase diagram for compounds up to 10 mol% scandia, including an ordered rhombohedral phase with low ionic conductivity. In this work, fully dense ScSZ specimens were obtained by high-pressure spark plasma sintering using deformable punches (DPSPS). Nanocrystalline powders containing 6, 8 and 10 mol% scandia were synthesized by simultaneous precipitation followed by heat treatment at 500ºC for 2 h. The mean grain sizes of specimens consolidated by DP-SPS at 700 and 800ºC and at 1.5 and 2 GPa, varied from 8 to 17 nm. The grain size dependent cubic phase stabilization was evidenced by Raman spectroscopy. High degree of translucence was obtained in dense specimens of ScSZ obtained by the DP-SPS method.

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  • IPEN-DOC 26122

    SILVA, PAULO M. ; ESPOSITO, VINCENZO; MARANI, DEBORA; FLORIO, DANIEL Z. de; FONSECA, FABIO C. . Ceria-based ceramic composites for high temperature thermochemical applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 989-989.

    Abstract: Among thermochemical conversion processes, the production of fuels such as H2 via solar thermochemical cycles is potentially more efficient and more economical than the use of electric energy to electrolyze water. The principle of solar thermochemical cycles is based on the remarkable properties of some oxides, which can be reduced and oxidized cyclically (redox cycles), i.e., releasing and absorbing oxygen under certain temperature (or pressure) regimes. These redox cycles can be efficiently used to convert H2O (or CO2) to H2 (CO). Thermochemical redox cycles avoid the problematic step of fuel / O2 separation and allow operation at more moderate temperatures (~ 1500 K) [1]. In this work, a new material concept for the separation of high temperature H2O based on porous ceramic composites composed of an ultra-high temperature ceramic phase (UHTC) and doped cerium oxide is proposed. UHTC usually exhibit extremely low mass diffusion rates and excellent thermomechanical properties for high temperature applications [2]. Gadolinium-doped ceria (CGO) presents unique processes at low oxygen partial pressure (pO2 < 10-12 atm) and high temperatures (T > 800 °C) such as faster mass diffusion, which are not observed in conventional sintering under ambient air conditions. In CGO/Al2O3 composites the resulting effects driven by such mass diffusion are low viscosity flows and high reactivity between phases, indicated by the formation of CeAlO3[3]. In this work, a comparison is made between sintering CGO/Al2O3 under ambient air and reducing condition, focusing on densification, viscosity and the evolution of the microstructure. The redox process of CGO/Al2O3 is investigated using dilatometry, microscopy, and electrochemical impedance spectroscopy. The preliminary results evidenced that new phases with remarkable microstructure can be obtained at reducing atmosphere depending on the temperature of reoxidation during cooling

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  • IPEN-DOC 26121

    VALLI, RICARDO; OLIVEIRA, FELIPE S.; OTUBO, LARISSA ; LANG, ROSSANO. CrSi2 layer synthesized by high current Cr ion implantation for Schottky diode applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1135-1136.

    Abstract: Among the transition-metal silicides, CrSi2 has received considerable attention as a material for silicon-based technologies because of its high-temperature stability, oxide-forming ability and semiconducting properties [1]. Its use in infrared photodetectors and Schottky barrier contacts has been of interest. Previous studies indicate that bulk CrSi2 has a hexagonal structure and p-type semiconductor character with a band gap of ≈ 0.35 eV [2]. In this work, we have synthesized and investigated the electrical-structural correlation of CrSi2 buried layer produced by high current Cr ion implantation. For this, Cr+ ions at an energy of 180 keV were implanted at high temperature (550 °C) at a fluence of 4x1017 ion/cm2. An n-type (001) surface-oriented Czochralski Si wafer (thickness 500 mm, resistivity 10-20 Ωcm) was used as host matrix. The chromium beam current density during implantation was about 6 μA/cm2. The Schottky diode formation consisted of the junction of metal and semiconductor, in this case, Au contact, and the CrSi2/Si, respectively. The formation of the crystallographic phase was identified by grazing incidence Xray diffraction. The buried layer morphology of silicide into substrate subsurface was revealed through scanning electron microscopy. Electrical conduction was characterized by resistivity measurements as a function of temperature (50 - 300 K), where two types of regimes are observed, i.e., two gaps: one of low temperature and one of high temperature (270 K). The electronic mobility was also obtained as a function of temperature by means Hall effect measurements. The transport of electrons above the potential barrier to the metal (Schottky barrier height), was determined by current-voltage curves (IxV) at room temperature.

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  • IPEN-DOC 26120

    FUJIMOTO, TALITA G. ; MUCCILLO, ELIANA N. dos S. . Effect of Pr on microstructure and dielectric properties of SrTiO3. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 146-146.

    Abstract: Polycrystalline ceramics based on strontium titanate (SrTiO3) have attracted great attention in recent years due to their interesting dielectric properties, e.g. high electric permittivity and low dielectric loss. SrTiO3 has many applications in electronic devices, sensors, actuators, fuel cells, among others. Recently, the effects of dopants on the dielectric properties of SrTiO3 have been investigated. Lui et al. [1] were the first to report a giant electric permittivity in Sr0.09Pr0.01TiO3 (> 3,000) at room temperature. In this work, the effect of Pr (0.025, 0.05 and 0.075% mol Pr) on the microstructure and dielectric properties of SrTiO3 was studied in detail. Samples were characterized by density measurement, X-ray diffraction, scanning electron microscopy and impedance spectroscopy. The results show that sintered samples at 1500 ºC/6 h exhibit high densities (> 96% of the theoretical value), independent on the additive content. The average grain size of SrTiO3 increases slightly with Pr addition. Specimens containing 0.075% mol Pr show high giant permittivity (about 30,000) at 540 ºC.

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  • IPEN-DOC 26119

    CARVALHO, SABRINA G. de M. ; MUCCILLO, REGINALDO ; MUCCILLO, ELIANA N. dos S. . Flash sintering of 3 mol% yttria-stabilized zirconia with AC and DC electric fields. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1062-1062.

    Abstract: Experiments on sintering ZrO2: 3 mol% Y2O3 polycrystalline ceramics (Y-TZP), pressed to cylindrical pellets, were carried out by heating to 1000 oC for application of a DC and AC (1 kHz) electric field (isothermal electric field-assisted sintering) of 200 V.cm-1 for 30 seconds, and 2 A as current limit. The experiments were carried out positioning cylindrical specimens inside a vertical dilatometer, with platinum meshes at the parallel surfaces connected with platinum wires to a power supply. Both 3YSZ sintered samples, besides having their apparent densities determined, had their surfaces observed in a scanning electron microscope to evaluate average grain size and distribution of grain sizes. Moreover, impedance spectroscopy analyses were carried out to evaluate the intergranular (mainly grain boundary) and intragranular (bulk) contributions to the electrical resistivity. The results show that besides both samples present similar densities and electrical resistivity, the one submitted to AC electric fieldassisted sintering presented smaller grains sizes and a discrete grain size distribution when compared to the one sintered with DC electric field.

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  • IPEN-DOC 26118

    CARVALHO, SABRINA G. de M. ; MUCCILLO, REGINALDO ; MUCCILLO, ELIANA N. dos S. . Electrical behavior and microstructural features of conventionally and electric field-assisted sintered 3 mol% yttria-stabilized zirconia. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 286-286.

    Abstract: ZrO2: 3 mol% Y2O3 ceramic powders, pressed to cylindrical pellets, were sintered conventionally at 1400oC (CS) and by applying an AC electric field in green (FS) and in pre-sintered (CS-FS) pellets. The electric field (200 V.cm-1, 1 kHz frequency, 3 A limiting current) was applied at 1000oC. The experiments were carried out positioning cylindrical specimens inside a vertical dilatometer furnace, with platinum meshes at the parallel surfaces connected with platinum wires to a power supply. The density of CS, FS and CS-FS were 98.9, 98.6 and 99.1% of theoretical density respectively. The average grain size were 282±73, 340±108 and 387±138 nm for conventionally sintering, conventionally follow by flash sintering and only flash sintered samples. Although the samples have close density values, the bulk and grain boundary conductivities of samples submitted to electric field assisted sintering are higher than conventional sintered sample. The intragranular and intergranular conductivities obtained by electrochemical impedance spectroscopy of CS, FS and CS-FS samples were 8.7 and 9.8, 9.4 and 10.2 and 13.7 and 29.6 kΩ.cm, respectively. These results show that the application of an AC electric field to a green or pre-sintered solid electrolyte enhances its ionic conductivity due to the welding of the grains and the increased in the oxide ion concentration due to diffusion to the grains of the chemical species depleted at the space charge region, enhancing the oxide ion concentration, both phenomena are provoked by the Joule heating produced by the electric current flow.

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  • IPEN-DOC 26117

    QUEIROZ, CARLOS A. da S. . Preparation of high purity cerium precursors for use in automotive catalysts. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1231-1231.

    Abstract: Starting with a fraction of mixed rare earths chloride with 47% in CeO2 , high pure cerium oxide and acetate was prepared. The mixed rare earths chloride solution was treated by fractionated precipitation technique. Cerium (III) was oxidized to cerium (IV) by addition of hydrogen peroxide. The acidity liberated in the hydrolytic process was neutralizes with NH3 stream generated by compressed air injected into the 1M NH4OH solution and bubbled into the rare chlorides solution. The temperature was maintained at 60oC. After the complete cerium hydroxide precipitation, it was separated by filtration. This hydroxide precipitate enriched in cerium (90% in CeO2) was dissolved in hydrochloric acid and the cerium chloride solution was used as the feeling solution to a strong cationic ion exchanger resin system. After loading the resin with de cerium, it was rinsed with water and eluted the ions by complexation with ammonium salt of EDTA adjusted to pH 4,0. Free EDTA acid was precipitated by addition of chloride acid to the cerium complex eluted and it was separated by filtration. The ultimate cerium chloride solution was treated with oxalic acid and the cerium oxalate separated, dried and fired to cerium oxide. The highly pure cerium oxide prepared (99.9%) was directly dissolved with hot concentrated acetic acid.The typical cerium acetate obtained contain the followings contaminants in micrograms per gram: Y(4.1 ), Sc (15.4 ), La (32.4), Pr (14.6), Nd (6.5), Sm (9.7), Eu (5.3), Gd (9.2), Tb (6.2), Dy (5.4), Ho (0.08) Er(0.9), Tm (0.2),Yb ( 20.5), Lu (2.3).

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  • IPEN-DOC 26116

    NASCIMENTO, MAURICIO S.; SANTOS, GIVANILDO A. dos; SOUZA, PAULO E.S.; FRAJUCA, CARLOS; NAKAMOTO, FRANCISCO Y.; SILVA, MARCIO R. da; SANTOS, VINICIUS T. dos; BATALHA, GILMAR F.; COUTO, ANTONIO A. . Correlation between microstructure, thermal parameters and hardness of a directionally solidified Al-Si-Cu alloy. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1123-1124.

    Abstract: Metals solidification involves the transformation of the molten metal back into the solid state. Solidification structures impact heavily on the final product’s characteristics. The microstructure effects on metallic alloys properties have been highlighted in various studies and particularly the dendrite arm spacing influence upon the mechanical properties such as hardness has been reported [1-3]. The aim of this work is to obtain correlations between microstructure and the hardness of Al-10wt%Si-2wt%Cu alloy casting. Initially, the alloy was formed by aluminum, copper and silicon commercially pure, fused in a clay-graphite crucible with an electric muffle furnace. After melting the mixture was poured into stainless steel AISI 304 chill and solidified under upward unsteady state heat flow conditions. Heat was directionally extracted only through a water-cooled bottom made of steel (SAE 1020). The experimental results include solidification thermal parameters such as volume fraction of the eutectic mixture, primary dendritic arm spacing and hardness.It is found that the hardness decreases with the increase of the primary dendritic spacing and with the decrease of the eutectic mixture fraction.

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  • IPEN-DOC 26115

    TABUTI, FRANCISCO N. ; PEREIRA, VICTORIA B. ; PIAZZOLLA, FERNANDO ; FONSECA, FABIO C. . Development of ceria-based direct ethanol intermediate-temperature solid oxide fuel cell. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 142-142.

    Abstract: Solid oxide fuel cells (SOFCs) have several advantages over traditional energygenerating devices. A key property is the possibility of using various fuels such as natural gas and ethanol, which are strategic for Brazil. This study addresses two aspects that need to be improved in SOFC: (a) the high operating temperature of the cell that brings several problems for assembly and operation of a power system, and (b) the deactivation of the cell due to the deposition of carbon on the surface of the nickel anode when the cell is fed with carbon-containing fuels. The properties of ceria-based/Ni cermets both as the anode material and as the catalytic layer for bio-ethanol fueled SOFC with yttria-stablilized zirconia electrolyte were investigated. Ceria-based/Ni cermets were studied as the catalytic layer deposited onto the standard yttria-stabilized zirconia/Ni anode for direct ethanol SOFCs. Properties of both Zr- and Nb-doped (10 mol%) ceria / Ni (15 vol%) cermets were investigated as the catalytic layer in direct ethanol SOFCs. Electrolyte-supported fuel cells with doped-ceria /Ni catalytic layer were tested for ~100 hours under (dry) ethanol. Fuel cells using the different ceria/Ni cermets showed excellent stability on ethanol. The promising results obtained with ceria-based anodes for SOFC of ethanol motivated the development of ceriabased SOFCs. Thus, intermediate-temperature SOFCs using doped-ceria electrolytes have been tested at 600 °C using hydrogen. Preliminary results show that direct ethanol SOFC are promising devices for efficient energy conversion at intermediate temperatures.

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  • IPEN-DOC 26114

    GUIMARAES, MARCOS de A.; SANTOS, GIVANILDO A. dos; AGUIAR, HERBERT C.G. de; SUYAMA, DANIEL I.; SILVA, MARCIO R. da; SANTOS, VINICIUS T. dos; NAKAMOTO, FRANCISCO Y.; FRAJUCA, CARLOS; BATALHA, GILMAR F.; COUTO, ANTONIO A. . Behaviour of PVD multi-layer coating carbide inserts in dry machining of nickel aluminium bronze alloy. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1459-1459.

    Abstract: The aluminium bronze alloys have machinability rate from 20 to 40% compared to free cutting brasses, so the cutting parameters and type of tools suitable for machining of these materials may be very different in comparison with other copper alloys. In this study was evaluated the flank wear rate of multi-layer PVD coating carbide insert in dry machining of nickel aluminium bronze CuAl10Ni5Fe5. The new advanced nano-layer coatings composed of numerous layers of the same, or combinations of different coating types can reduce dramatically the tool flank wear compared to conventional monolayer coatings [1]. The CuAl10Ni5Fe5 alloy was machining by CNC turning at different cutting speeds (cutting conditions). The surface and wear of carbide inserts were analysed by Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM/EDS). The results showed very small flank wear produced by abrasion on the cutting edge even with the increase of cutting speed from 80 to 450 m/min.

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  • IPEN-DOC 26113

    QUEIROZ, CARLOS A. da S. . Synthesis and characterization of neodymium acetate for use in nanotechnology. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1222-1222.

    Abstract: A simple and economical chemical process to obtaining neodymium acetate of high purity was studied. The raw material in the form of mixed rare earths carbonate comes from Brazilian monazite. It was used the technique of strong cationic exchange resin, proper to water treatment to the neodymium''s fractionation and it is achieved a purity of 99.9% in Nd2O3 and yield greater than or equal 80%, with the elution of rare earths by EDTA solution in pH controlled. The complex of EDTA-neodymium is transformed in neodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the neodymium acetate. The solid salt was characterized via chemical analysis, thermal analysis, X ray diffraction, infrared spectroscopy and inductively coupled plasma mass spectrometry to certify the purity.The analytical data collected allowed to conclude that the stoichiometric formula for the compound is Nd(CH3COO)3.1.5H2O. The typical neodymium acetate obtained (purity ≥ 99.9%) contain the followings contaminants in micrograms per gram: Y(0.9), Sc (5.1), La (1.0), Pr (3.4), Sm (12.8), Eu (1.1), Gd (15.4), Tb (2.9), Dy (5.3), Ho (7.4) Er(1.5), Tm (0.3),Yb ( 2.5), Lu (1.0).

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  • IPEN-DOC 26112

    SILVA, THAMYSCIRA H.S.; GRILO, JOÃO P.F.; ARAUJO, ALLAN J.M.; LOUREIRO, FRANCISCO J.A.; FAGG, DUNCAN P.; FONSECA, FABIO C. ; MACEDO, DANIEL A.. Structure, densification and electrical properties of Gd3+ and Cu2+ co-doped ceria solid electrolytes for SOFC applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 911-912.

    Abstract: The current energy needs are still met by the use of fossil fuels. Due to the increasing demand for new energy sources, solid oxide fuel cell has proven to be a good alternative. However, the development of this technology is limited by needs high operation temperature. Ceria-based solid electrolytes have been considered a promising material due to better ionic conductivities in comparison to traditional yttria-stabilized zirconia ceramics. The main disadvantage of ceriabased electrolyte is the need for high sintering temperatures for complete densification. Transition metal oxides exhibiting low melting points, such as CuO, have been used as additives to lower the sintering temperature of these materials [1]. In this scenario, the present work is focused on the evaluation of the effects of gadolinium oxide (Gd2O3) content and small quantity of CuO on the structure, densification and electrical properties of ceria solid solutions [2]. Nominal compositions of Ce0.99−xGdxCu0.01O2-δ (0≤x≤0.3) were synthesized by the polymeric precursor method. The calcined powders were studied by XRD and Rietveld refinement to obtain crystallographic parameters. The sinterability of green bodies was evaluated by dilatometry up to 1200 °C. The electrical properties were investigated by impedance spectroscopy. The electrical conductivity was enhanced by gadolinium addition, reaching a maximum of 7.81 mS cm−1 at 600 °C for the composition x=0.15 sintered at a temperature as low as 1050 °C.

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  • IPEN-DOC 26110

    REY, JOSE F.Q.; MATOS, BRUNO R. ; LONGO, ALESSANDRO; FONSECA, FABIO C. ; MERINO, DANIEL H.. Nafion/CsHSO4 hybrids SAXS/ WAXS/ XAS studies. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 230-230.

    Abstract: Nafion (Developed by DuPont) has been largely employed as solid electrolytes in Polymer Electrolyte Membranes (PEM) fuel cell applications. However, mild conditions (intermediates temperatures (~80 C), high relative humidity, and pure hydrogen fuel) are required to yield high fuel cell performances [1]. Nafion-based hybrid materials have been suggested as potential candidates to improve the performance of PEM fuel cells at higher temperatures and lower humidity conditions whilst maintaining the chemical stability and mechanical strength of the standard electrolyte. Hybrid materials are generally synthesized by the incorporation of hydrophilic inorganic nanoparticles in the polymer structure aiming at PEM operating above 100 °C [2]. The precursor solution impregnates the Nafion membrane and a subsequent thermal treatment induces the nucleation and growth of the nanoparticles inside the membrane. In the last decade, great efforts have been focused on the investigation of the property-structure relationship to improve the technological applications [3]. The aim of our study is to study the mechanism of growth of the nanoparticles embedded at the Nafion membranes by SAXS (Small Angle X Ray Scattering)/ WAXS (Wide Angle X Ray Scattering) as well as to understand the chemical environment of the nanoparticles within the polymeric internal structure by XAS (X Ray Absorption Spectroscopy) in the Caesium (Cs) K-edge. The main results shown a strong relationship between the hybrid membranes morphology and the concentration/synthetic route of the inorganic species.

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  • IPEN-DOC 26090

    ROLINDO, N.C. ; TESSARO, A.P.G. ; SMITH, R.B. ; CAMPOS, C.; MARUMO, J.T. ; VICENTE, R. . Disused sealed radioactive sources: inventory and characterization at IPEN. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26089

    MORAES, MARCIA C.D. ; PEREIRA, DAISA L. ; ANA, PATRICIA A. da; FREITAS, ANDERSON Z. de ; ZEZELL, DENISE M. . Optical attenuation coefficients obtained through OCT correlates to microhardness in dental human enamel irradiated with Nd: YAG and submitted to demineralization in vitro. In: RECHMANN, PETER (Ed.); FRIED, DANIEL (Ed.) SPIE PHOTONICS WEST; SPIE BIOS, February 2-7, 2019, San Francisco, USA. Abstract... Washington, USA: SPIE, 2019. (Proceedings SPIE 10857, Lasers in Dentistry XXV).

    Abstract: This work aims was to correlate the changes in the optical attenuation coefficients obtained through the OCT technique with the values obtained in Knoop sectional microhardness tests over time in dental human enamel samples irradiated with the Nd: YAG laser and Acid Phosphate Fluoride (APF), aiming the prevention of caries lesions in vitro. After Ethical Committee approval, 160 enamel samples, obtained from 40 human tooth molars, were divided into 4 groups: Control group (where no treatment was performed); Fluoride group (APF - fluoride phosphate acidulated for 4 minutes); Fluoride-Laser group: APF followed by irradiation with Nd:YAG laser (DE = 84.9 J/cm2, contact mode, with the use of carbon paste as photoabsorver); Laser-fluoride group (irradiation with Nd:YAG laser followed by APF). The samples of all groups were subjected to pH cycling during 20 days. On days 5, 10, 15 and 20, 10 samples from each group were removed from the cycling for the Knoop sectional microhardness test. Two samples of each group, at each time, were randomly selected for the analysis with FTIR-ATR (Fourier transform infrared spectroscopy associated with attenuated total reflection technique). The analysis by ATR-FTIR showed changes in the chemical composition of the samples of the irradiated groups in relation to Control and Fluoride group. There was correlation between the values of sectional microhardness tests and the measured optical attenuation coefficient by OCT in irradiated dental enamel, showing that the association between fluoride application and Nd:YAG laser irradiation is an important tool for the prevention of tooth enamel demineralization.

    Palavras-Chave: tomography; coherent radiation; teeth; caries; neodymium lasers; enamels; fluorides; demineralization; irradiation; attenuation

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  • IPEN-DOC 26088

    MAYNARD, ISABELLA F.N.; CAVALCANTI, ELIANE B.; MARTINS, ELAINE A.J. ; SILVA, LARISSA L. da ; PIRES, MARIA A.F. ; MARQUES, MARIA N.. Avaliação da presença de desreguladores endócrinos em água subterrânea e tratada em uma área rural. In: ARENZON, ALEXANDRE (Ed.); NUNES, MARIA E.T. (Ed.); BOTTA, CLARICE M.R. (Ed.); ESPINDOLA, EVALDO L.G. (Org.); NOVELLI, ANDREA (Org.) CONGRESSO BRASILEIRO DE ECOTOXICOLOGIA, 15th, 1-4 de setembro, 2018, Aracaju, SE. Resumo expandido... Campinas: Sociedade Brasileira de Ecotoxicologia, 2018. p. 672-674.

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  • IPEN-DOC 26073

    ALBANO, A.M.S. ; ARTHUR, V. . Efeito da radiação gama na inibição da germinação de ervilha in natura (Pisum sativum L.). In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26072

    CAMPOS, R.F. ; CAMPOS, V.P. ; MITAKE, M.B. ; ARAUJO, E.B. . Analise dosimétrica de um laboratório de radiobiodistribuição in vivo usando CaSO4:Dy. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26071

    SILVA, T.M.; KODAMA, Y. ; SOMESSARI, S.L. ; OMI, N.M. ; NORMANTON, K.A.F.; VASQUES, F.M.F. ; DUARTE, C.L. ; SAMPA, M.H.O. ; CALVO, W.A.P. . Desenvolvimento de procedimentos e metodos de monitoração individual e de área em uma unidade móvel de irradiação por feixe de elétrons. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: waste management; water pollution; industrial wastes; water treatment; chemical effluents; organic wastes; chemical wastes; ionizing radiations; radiodisinfestation; radiation doses; microorganisms; electron beams; monitoring; water pollution monitors; implementation; brazilian cnen

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  • IPEN-DOC 26070

    COELHO, ANASTACIA L.L.P.B.; PINHEIRO, ANGELICA L.L.P.; SIMPSON, STEPHANIE C.; ZEITUNI, CARLOS ; ROSTELATO, MARIA E.C.M. . A radiação ionizante como forma de tratamento nas mulheres com câncer de colo de útero em Araguaína –TO nos anos de 2000 a 2015. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Abstract: O câncer vem se apresentando como um grave problema de saúde pública em todo mundo as sociedades globais, especialmente em países subdesenvolvidos. Em 2005, de um total de 58 milhões de mortes ocorridas no mundo, o câncer foi responsável por 7,6 milhões (13%). Desse total, mais de 70% ocorreram em países de média ou baixa renda. Atualmente, o câncer é a segunda causa de morte no Brasil (10,3% do total), excluídas as causas indeterminadas, ficando atrás somente de doenças cardiovasculares . Para 2018, há uma estimativa de 16.370 novos casos, sendo que, 2.300 se encontram na região Norte do país. O câncer de colo uterino é o segundo tipo de câncer mais frequente entre as mulheres em todo o mundo. A sua frequência, entretanto, é bastante variável de acordo com o desenvolvimento do país estudado, sendo que 83% dos casos registrados no mundo acontecem em países em desenvolvimento, onde o risco cumulativo é de 1,5% aos 65 anos. Este trabalho trata-se de um estudo descritivo, retrospectivo, quantitativo-interpretativo, com analise de dados secundários do período de 2000 a 2015 do Registro Hospitalar de Câncer pelo Sistema de Informação em Saúde (SIS-RHC), vinculado ao Hospital Regional de Araguaína. Os dados foram tabulados em planilhas eletrônicas do excel onde foram obtidas variáveis estatísticas e frequência para análise. . Foram analisadas 2.664 mulheres com câncer de Colo de Útero no Hospital Regional de Araguaína. Sendo divididas em 17 variáveis na “Ficha de Tumor”; o histórico de bebida alcoólica e de tabaco apresentaram as maiores porcentagens de ausência de preenchimento (mais de 31%). Em seguida, 25,9% das fichas não tiveram o preenchimento da escolaridade. De uma forma geral, pode-se notar que das 17 informações utilizadas neste estudo, 55,7% das fichas continham todas as informações e 12, 2% tinham 4 ou mais informações ausentes. Observa-se entre o tempo de diagnóstico e tratamento que as mulheres diagnosticadas tardiamente apresentaram, em média, tempos maiores entre as duas ações. a maioria das pacientes tiveram um diagnóstico tardio, com isso a radioterapia se tornou a principal forma de tratamento.

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  • IPEN-DOC 26069

    ALVARENGA, T.S. ; POLO, I.O. ; PEREIRA, W.W.; CALDAS, L.V.E. . Anisotropia da fonte de 241AmBe do laboratório de calibração com nêutrons do IPEN. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: anisotropy; americium 241; beryllium; calibration; neutron detection; measuring instruments; brazilian cnen; radiation protection

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  • IPEN-DOC 26068

    LITVAC, D. ; CALDAS, L.V.E. . Caracterização dosimétrica do LiF-nrpb para calibração de aplicadores clínicos de betaterapia. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: radiotherapy; personnel; occupational safety; beta dosimetry; lithium fluorides; brazilian cnen; dosimetry; radiation doses; calibration; recommendations; beta radiography

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  • IPEN-DOC 26067

    SANTOS, W.S.; NEVES, L.P.; PERINI, A.P.; CALDAS, L.V.E. . Uso de modelagem computacional para avaliação da exposição médica e ocupacional durante procedimento de cardiologia intervencionista. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: fluoroscopy; biomedical radiography; cardiovascular system; images; medical personnel; patients; radiation doses; radiation protection; occupational safety; computer codes; programming

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  • IPEN-DOC 26066

    CASTRO, M.C. ; SILVA, N.F. ; CALDAS, L.V.E. . Some characterization tests for an extrapolation chamber in CT standard beams in a specific chamber depth. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: radiation detectors; computerized tomography; diagnostic uses; ionization chambers; calibration standards; x radiation; radiation doses; radiation quality; extrapolation chambers

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  • IPEN-DOC 26065

    ANTONIO, P.L. ; CALDAS, L.V.E. . Comportamento do sinal TL/OSL e PTTL/PTOSL após tratamento térmico pós-irradiação com fonte de 60Co, em amostras de LiF:Mg,Ti e CaSO4:Dy. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: dosimetry; thermoluminescence; optical equipment; ultraviolet radiation; radiation detection; heat treatments; cobalt 60; thermoluminescent dosemeters; thermoluminescent dosimetry

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  • IPEN-DOC 26064

    LIMA, B.L.; ALMEIDA, J.S. ; POTIENS, M.P.A. ; PELISSONI, R.A.; SAPIENZA, M.T.; BUCHPIGUEL, C.A.; WILLEGAIGON, J.. Evaluation of biokinetics and dosimetry in [131I]-NaI therapies: whole-body images quantification versus lower limb region. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26063

    TAVARES, P.S.; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Princípio de investigação do dosímetro Fricke Gel modificado utilizando um equipamento de CT Óptico. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26062

    SAUEIA, C.H.R. ; NISTI, M.B. ; MAZZILLI, B.P. . Determinação de Cs-137 e radionuclídeos naturais em sedimentos do Sistema Estuário da Baixada Santista, Brasil. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26061

    SILVA, N.F. ; SILVA, T.F.; CASTRO, M.C. ; LUZ, H.N. da; CINTRA, F.B. ; CALDAS, L.V.E. . Simulation of a TH-GEM based detector for standard mammography-quality beam dosimetry using the MCNP5 code. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: electron multiplier detectors; beams; dosimetry; mammary glands; monte carlo method; radiation transport; x radiation; shielding; dosemeters; thickness

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  • IPEN-DOC 26060

    SILVA, E. ; SANTOS, L.R. ; ASSEMANY, L.P.F. ; POTIENS, M.P.A. . Evaluation of the performance of radioprotection ionization chambers used in radiometric survey of radiology clinical systems. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26059

    NISTI, M.B. ; CAMPOS, M.P. ; SILVA, G.M. ; MAZZILLI, B.P. . Determinação da taxa de exalação do 222Rn no solo do IPEN. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26058

    TAMURA, T.M.; SOUZA, R.E.; NEVES, L.P.; PERINI, A.P.; SANTOS, W.S. . Cálculo de fator de conversão para dose absorvida em atividade de navegação utilizando o método Monte Carlo e um simulador antropomórfico virtual. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26057

    CORREIA, R.W. ; ROSTELATO, M.E.C.M. ; ZEITUNI, C.A. . Estudo e calibração de detector HPGe para análise radionuclídica de iodo-125. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26056

    ABREU, R.T. ; ANGELOCCI, L.V. ; NOGUEIRA, B.R. ; SANTOS, H.N. ; ZEITUNI, C.A. ; ROSTELATO, M.E.C.M. . Dose-rate constant evaluation of a new 192-Ir brachytherapy source using Monte-Carlo and experimental parameters. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26055

    BAPTISTA, T.S. ; ZEITUNI, C.A. ; RODRIGUES, B. ; MOURA, J. ; ROSTELATO, M.E. . Efficiency test on three types of sanitizers for cleaning sealed radioactive sources for brachyterapy. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26054

    ANDRADE, M.A.B.; ALVES, C.O.; FIN, A.P.C.; SOARES, F.A.P.; SAVI, M. ; POTIENS, M.P.A. . Visual impact of infill percentages for 3D printed radiologic simulators. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26053

    PRADO, E.S.P. ; MIRANDA, F.S.; PETRACONI, G.; POTIENS JUNIOR, A.J. . Tratamento de rejeitos radioativos compactáveis aplicando a tecnologia plasma para redução volumétrica. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26052

    MARTINS, E.W. ; BUENO, L.K. ; POTIENS, M.P.A. . Implementação de uma instalação para implantação da nova metodologia de calibração de ativímetros. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26051

    DIAS, A.J.R. ; VILELA, A.N. ; VICENTE, R. ; DELLAMANO, J.C. . Acidentes radiológicos: dados que auxiliam a proteção radiológica. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26050

    OLIVEIRA, J.J.; VICENTE, R. . Relevância radiológica relativa: Angra 1 e 2. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26049

    TESSARO, A.P.G. ; SMITH, R.B. ; ROLINDO, N.C. ; VICENTE, R. . Opening the Goiania accident unburied waste packages. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26048

    GASPARIAN, P.B.R. ; YOSHIMURA, E.M.; UMISEDO, N.K.; CAMPOS, L.L. ; MALTHEZ, A.L.M.C.. Study of the dosimetric properties of CaSO4:Dy using OSL technique. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 326-326.

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  • IPEN-DOC 26047

    SILVA, A.M.B.; JUNOT, D.O. ; CALDAS, L.V.E. ; SOUZA, D.N.. TL and OSL characterization of CaSO4:Tb, CaSO4:Tb,Ag, and CaSO4:Tb,Ag(NP). In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 321-321.

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  • IPEN-DOC 26046

    POLO, IVON O. ; CALDAS, LINDA V.E. . SOL-GEL α-Al2O3 detectors: TL and OSL response to beta radiation beams. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 317-317.

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  • IPEN-DOC 26045

    JUNOT, DANILO O. ; SOUZA, DIVANIZIA N.; CALDAS, LINDA V.E. . The influence of the preparation route in the TL/OSL signal of CaSO4:Eu,Ag samples. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 310-310.

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  • IPEN-DOC 26013

    ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Phototransfer analysis on TL and OSL responses of LiF:Mg,Ti (TLD-100) after exposure to 60Co radiation. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 302-302.

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  • IPEN-DOC 26012

    ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Influence of the thermal treatment on the PTTL and PTOSL signals from different natural materials. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 301-301.

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  • IPEN-DOC 26044

    VILLANI, D. ; MORENO, C.S.; SAKURABA, R.K.; GONÇALVES, V.D.; CAMPOS, L.L. . Optically stimulated luminescence dosimetry characterization with clinical photon beams and LINAC measurements. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 299-299.

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  • IPEN-DOC 26043

    VENEZIANI, G.R. ; MATSUSHIMA, L.C.; GAGLIARDO, K.M.; CARVALHO, T.P.A.; SAKURABA, R.K.; CAMPOS, L.L. . Development of phantom using 3D printer for veterinary radiosurgery. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 297-297.

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  • IPEN-DOC 26042

    SILVA, NATALIA F. ; SILVA, TIAGO F.; CASTRO, MAYSA C. ; LUZ, HUGO N. da; CINTRA, FELIPE B. ; CALDAS, LINDA V.E. . Simulation of geometry and materials of the TH-GEM based detector for radiation dosimetry. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 253-253.

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  • IPEN-DOC 26041

    BARRERA, GERARDO R.; ALMEIDA, ADRIEL S.; JUNOT, DANILO O. ; SOUZA, DIVANIZIA do N.. Synthesis and TL and OSL characterization of (MgB2O4-MgB4O7): Ce:Li and (MgB2O4-MgB4O7): Dy:Li glasses for dosimetry. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 216-216.

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  • IPEN-DOC 26040

    NASCIMENTO, BRUNA C.; FRIMAIO, AUDREW ; BARRIO, RAMON M.M.; SIRICO, ANA C.A.; COSTA, PAULO R.. Comparative analysis of the transmission properties of radiologically equivalent materials. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 212-212.

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  • IPEN-DOC 26039

    FRIMAIO, AUDREW ; NASCIMENTO, BRUNA C.; BARRIO, RAMON M.M.; CAMPOS, LETICIA L. ; COSTA, PAULO R.. X-ray spectrometry applied for determination of linear attenuation coefficient of tissue-equivalent materials. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 207-207.

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  • IPEN-DOC 26038

    CASTRO, MAYSA C. ; SILVA, NATALIA F. ; SANTOS, LUCAS R. ; CINTRA, FELIPE B. ; CALDAS, LINDA V.E. . Evaluation of an extrapolation chamber for dosimetry in computed tomography beams using Monte Carlo code (MCNP5). In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 204-204.

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  • IPEN-DOC 26037

    SANTOS, CARLA J.; SANTOS, WILLIAM S.; NEVES, LUCIO P.; BELINATO, WALMIR; CALDAS, LINDA V.E. ; PERINI, ANA P. . Dose determination in pediatric interventional cardiology procedures: Monte Carlo approach. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 191-191.

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  • IPEN-DOC 26036

    SANTOS, WILLIAM S.; SANTOS, CARLA J.; NEVES, LUCIO P.; BELINATO, WALMIR; CALDAS, LINDA V.E. ; PERINI, ANA P. . Numerical dosimetry in brachytherapy to variable mama sizes using two different types of 125I seeds. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 190-190.

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  • IPEN-DOC 26035

    NEVES, LUCIO P.; BORGES, ADRIANE; SOARES, MARIA R.; BELINATO, WALMIR; SANTOS, WILLIAM S.; CALDAS, LINDA V.E. ; PERINI, ANA P. . Computational dosimetry in a pediatric iCAT procedure using a virtual antropomorphic phantom. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 189-189.

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  • IPEN-DOC 26034

    SOUZA, LUCAS W.G.; POZZO, LORENA ; PERINI, ANA P. ; BELINATO, WALMIR; SANTOS, WILLIAM S.; CALDAS, LINDA V.E. ; NEVES, LUCIO P.. Monte Carlo simulation of microPET/CT occupational exposure using 18F and 68Ga tracers. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 179-179.

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  • IPEN-DOC 26033

    SILVA, ROGERIO M.V.; BELINATO, WALMIR; SANTOS, WILLIAM S.; PERINI, ANA P. ; NEVES, LUCIO P.; SANTOS, CARLA J.; SOUZA, DIVANIZIA N.. Low cost electron irradiator using 90Sr+90Y sources. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 178-178.

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  • IPEN-DOC 26032

    MATSUSHIMA, L.C.; VENEZIANI, G.R. ; SAKURABA, R.K.; CAMPOS, L.L. . Verification of absorbed doses using thermoluminescent detectors and mapping of isodose curves in IMRT planning. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 177-177.

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  • IPEN-DOC 26031

    MARTINS, ELAINE W. ; CARDOSO, JOÃO V.; POTIENS, MARIA da P.A. . Paediatric phantom performance evaluation in computed tomography radiation standard beams. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 176-176.

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  • IPEN-DOC 26030

    AMARAL, CAIO E.S.; LIMA, CAIO L.; BELINATO, WALMIR; NEVES, LUCIO P.; PERINI, ANA P. ; SANTOS, WILLIAM S.; ALMEIDA, EDSON P.B. de; NAVARRO, MARCUS V.T.. Simulation of a laboratory for the radiation detectors calibration. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 103-103.

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  • IPEN-DOC 26029

    LIMA, CAIO L.; AMARAL, CAIO E.S.; BELINATO, WALMIR; NEVES, LUCIO P.; PERINI, ANA P. ; SANTOS, WILLIAM S.; ALMEIDA, EDSON P.B. de; NAVARRO, MARCUS V.T.. Computational simulation of the detectors designed for computer tomography. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 102-102.

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  • IPEN-DOC 26028

    CORTEZ, BRUNA ; CHUBACI, JOSE F.D.; GOMES, MONISE B. ; OLIVEIRA, LETICIA M. ; SATIRO, LUCAS C. ; ROCCA, RENE R.; ARIZACA, EDY E.C.; WATANABE, SHIGUEO. Dating sediments from a terrace found in Iguape - Icapara in southeast coast in the state of São Paulo, Brazil. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 85-85.

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  • IPEN-DOC 26027

    GOMES, MONISE B. ; CORTEZ, BRUNA ; OLIVEIRA, LETICIA M. de ; CARMO, LUCAS S. do ; CHUBACI, JOSE F.D.; ROCCA, RENE R.; WATANABE, SHIGUEO. Dating of shells from Pântano da Malhada, Rio de Janeiro. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 81-81.

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  • IPEN-DOC 26026

    GROPPO, DANIELA P. ; SARAIVA, CRYSTIAN W.C.; CALDAS, LINDA V.E. . Determination of the penumbra width of Elekta SRS Cone Collimator for 6 MV FF and 6 MV FFF energies using Gradient-Based Edge Detection. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 72-72.

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  • IPEN-DOC 26025

    FONSECA, T.C.F.; SENIWAL, B.; MENDES, A.M.; BELO, M.C.L.; LACERDA, M.A.S.; MENDES, M.B.; PAIXÃO, R.L.; JOANA, G.S.; SANTANA, P.; MARQUES, J.; SQUAIR, L.P.; ANTUNES, P. ; YORIYAZ, H. ; BASTOS, F.. MCMEG: InterComparison exercise on radiotherapy assessment prostate dose. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 66-66.

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  • IPEN-DOC 26024

    SOUZA, PAULO R.D. de ; RODRIGUES, BRUNA T. ; MACHADO, LUCAS K. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Evaluation of dose received in adjacent organs in the dosimetric plan of lung cancer. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 64-64.

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  • IPEN-DOC 26023

    SOARES, MARIA R. ; SANTOS, WILLIAM S.; NEVES, LUCIO P.; PERINI, ANA P. ; MAIA, ANA; BELINATO, WALMIR; CALDAS, LINDA V.E. . Computational modeling of thyroid shields and lead eyewear and the impact on the absorbed doses of eye lens and thyroid gland in CBCT exams. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 56-56.

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  • IPEN-DOC 26022

    BELINATO, W.; ALMEIDA, E.P.B. de; NEVES, L.P.; PERINI, A.P. ; CALDAS, L.V.E. ; SANTOS, W.S.. Occupational exposures in PET procedures with 18F-FDG. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 55-55.

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  • IPEN-DOC 26021

    ASSEMANY, LADYJANE P.F. ; RODRIGUES JUNIOR, ORLANDO ; POTIENS, MARIA da P.A. . Evaluation of 3D printing filaments for construction of a pediatric phantom for dosimetry in CBCT. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 54-54.

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  • IPEN-DOC 26020

    ALVARENGA, TALLYSON S. ; POLO, IVON O. ; PEREIRA, WALSAN P.; SILVA, FELIPE S.; FONSECA, EVALDO S.; CALDAS, LINDA V.E. . Contribution of the scattered radiation on the neutron beam fluence in the neutron calibration laboratory at IPEN. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 48-48.

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  • IPEN-DOC 26019

    ALMEIDA, S.B. ; VILLANI, D. ; SAKURABA, R.K.; REZENDE, A.C.P.; CAMPOS, L.L. . Comparison between Al2O3:C pellets and DIODEs for TSEB in vivo dosimetry using an anthropomorphic phantom. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 47-47.

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  • IPEN-DOC 26018

    SILVA-CARRERA, BETZABEL N. ; CANO, NILO F.; WATANABE, SHIGUEO. Low dose radiation dosimetry using natural blue quartz crystal by TL technique. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 39-39.

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  • IPEN-DOC 26017

    COSTA, NATHALIA A. ; POTIENS, MARIA da P.A. ; PATALLO, ILEANA S.; DIMITRIADIS, ALEX. Phantom development and implementation for Gamma Knife® dosimetry. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 24-24.

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  • IPEN-DOC 26016

    CARMO, L.S. do ; WATANABE, S. ; SILVA, R.J.; CHUBACI, J.F.D.. Dating aeolian sediments using ESR Ti-Li center in quartz, TL and OSL-SAR: Dama Branca, study. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 23-23.

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  • IPEN-DOC 26015

    GONZALES-LORENZO, CARLOS; WATANABE, SHIGUEO; BUENO, CARMEN ; KODAIRA, SATOSHI; NASCIMENTO, LUANA. CaSiO3 polycrystal for neutron, proton and carbon detection. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 20-20.

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  • IPEN-DOC 26014

    VILLANI, D. ; DORES, D.S. das; SILVA, V.R. da; COSTA, Z.M. da; CAMPOS, L.L. . Er+Ag-doped phosphate glass as luminescent dosimeters. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 325-325.

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  • IPEN-DOC 26011

    SANTOS, W.S. ; NEVES, L.P. ; PERINI, A.P.; BELINATO, W.; CALDAS, L.V.E. . Evaluation of polymer gels using Monte Carlo simulations. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 80-80.

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  • IPEN-DOC 26010

    SILVA, EZEQUIEL da ; ASSEMANY, LADYJANE P.F. ; POTIENS, MARIA da P.A. . Performance evaluation of a cilindrical ionization chamber used in radiation protection measurements of diagnostic radiology clinical systems. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 60-60.

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  • IPEN-DOC 26009

    CASTRO, PEDRO A.A. de ; ZEZELL, DENISE M. ; MORAIS, MYCHEL R.P.T.; ZORN, TELMA M.. Semi quantitative evaluation of skin burn wound healing: ATR-FTIR study. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42nd, 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: The role of skin wound healing the biochemical mechanisms are still not fully understood and spectroscopy may shine some light on this information. The Fourier Transform Infrared spectroscopy coupled with Attenuated Total Re°ectance (ATR-FTIR) has been demonstrated potential to monitor the biomolecule activity upon biological samples. This work aims to evaluate the feasibility of using ATR-FTIR to discriminate burned skin throughout wound stages. Water vapor at 90±C was applied to the dorsum of Wistar rats resulting in standardized third-degree burns. Tissue samples were collected after 3±, 7±, 14± and 21 days post burn injury. For the acquisition of the spectra, 150 scans were averaged with a resolution of 4 cm¡1 and wavenumbers ranging from 4000 to 400 cm¡1. Analysis of the spectra was calculated using MATLABR°R2015a (MathWorks, Natick, MA) software. Fingerprint region (900 - 1800 cm¡1) and high wavenumber (2800 - 3000 cm¡1) of spectra were o®set-corrected and vector normalized. Area under the curve (AUC) of collagen (1236 cm¡1), amide II (1540 cm¡1), amide I (1632 cm¡1) and lipid (2852 cm¡1) of each group were performed by integration method. The FTIR results exhibit the high biochemical activity of the tissue in the 14o post burn injury when it is compared with control group which correspond to the stage when the new tissue formation is still ongoing. The lipid content decrease in the 21 day, which suggest that the metabolic activity and structural reorganization decrease as the wound healing progress. For future works, micro-FTIR imaging will be used spatially discriminate the bands.

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  • IPEN-DOC 26008

    AMARAL, MARCELLO M.; ARAUJO, JEANN C.R.; ANTUNES, ANDREA; MONTE, ADAMO F.G.; CARA, ANA C.B. de ; FREITAS, ANDERSON Z. de ; ZEZELL, DENISE M. . Phantom validation of optical attenuation coefficient estimation model with depth resolution for Optical Coherence Tomography. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42nd, 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Optical Coherence Tomography (OCT) has been used for imaging and analyzes over a broad number of applications.[1-3] Besides its use for morphological analysis [3] the OCT signal has been used to determine the optical attenuation coe±cient of biological samples for classi¯cation and diagnostic proposes. [1,2] The most common model for estimating the optical attenuation coe±cient based on OCT signal relies on the Lambert- Beers law. It usually assumes a constant attenuation coe±cient value over the image range or over a selected range, losing the in-depth resolution on OCT. Previous published work on literature developed a model to esti- mate the attenuation coe±cient with depth resolution [4], however it assumes that the light is totally attenuated within the image depth range failing for membrane like samples. We present a model that, using the tissue sample transmittance as input, remove this limitation and to estimate the depth-resolved optical attenuation coe±cient. This method allows us to obtain an image of tissue optical properties instead of that from intensity contrast, guiding diagnosis and tissues di®erentiation, extending its application from thin to tick samples. The performance of our method was tested with the assistance of a home built single layer and multi-layer phantoms ( 100¹m each layer). These optical phantoms are composed of a substrate polydimethylsiloxane (PDMS), Zinc- Phthalocyanine (ZnPc) dye as chromophores, and TiO2 as scattering agent. The optical attenuation coe±cient ranges from 0:9 to 2:32 mm¡1, measured using an integrating sphere followed by the Inverse Adding Doubling processing technique. We show that the estimated depth-resolved attenuation coe±cient recovers the reference values, with a error deviation of 7 %.

    Palavras-Chave: tomography; phantoms; optical equipment; optical properties; resolution; images; light coherence; coherent radiation

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  • IPEN-DOC 26007

    LIMA, CASSIO ; BYRNE, HUGH; CORREA, LUCIANA; ZEZELL, DENISE . Molecular pathology via infrared spectral imaging for skin cancer diagnosis. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42nd, 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a rapid and label-free analytical technique that provide information about the overall biochemical pro¯le of biological samples based on the vibrations of its basic molecular components (carbohydrates, proteins, lipids and nucleic acids) that are infrared active. The potential biomedical applications of FTIR spectroscopy as a tool for cancer diagnosis have been well demonstrated over the last years. However, most studies have focused on evaluate the diagnostic ability of FTIR by comparing healthy tissue to cancers on advanced stage and few studies have centered on evaluating the early stages of cancer. Thus, the present study aims to demonstrate the ability of FTIR spectroscopy to discriminate healthy skin from advanced skin cancer (squamous cell carcinoma) as well as from early stages of malignancy using the information retained by spectral data. Cutaneous neoplastic lesions were chemically-induced on Swiss mice using a well-stablished two-stage carcinogenesis protocol. Healthy tissue was collected from animals non-exposed to chemicals and di®erent disease stages were obtained by varying the exposure time of animals to carcinogenenic factors. Tissue sections were obtained from formalin-¯xed para±n-embedded (FFPE) and placed on calcium °uoride substrates. FTIR hyperspectral images were acquired in transmission mode over mid-infrared spectral region and compared using Principal Components Analysis (PCA) associated to Linear Discriminant Analysis (PC-LDA). Satisfactory data discrimination (accuracy, sensitivity and speci¯city) was achieved by PC-LDA and the variables responsible by classi¯cation were evaluated in order to assess the spectral changes of skin components during the transition of healthy into diseased state. Our ¯ndings demonstrate the potential of FTIR spectroscopy not only for skin cancer diagnosis, but also to evaluate the biochemical events triggered by cancer without requiring laborious and time-consuming procedures or expensive labeled probes as biomarkers.

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  • IPEN-DOC 26006

    PEREIRA, DAISA L. ; CASTRO, PEDRO A.A. ; GOMES, GABRIELA V. ; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. ; RIBEIRO, HENRIQUE B.; MATOS, CHRISTIANO J.S.; ANA, PATRICIA A.. Heat-induced depth of Nd:YAG laser irradiation in biological hard tissues. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42nd, 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Confocal Raman spectroscopy is a non-destructive and non-invasive technique which provides surface Raman spectra and depth images of biological structures contactless with the sample, with no use of ionizing radiation to penetrate in the sample under analysis. These characteristics allow its experimental use without any side e®ects to the sample. The depth images are obtained by Raman microscopy and are related to the characteristics of the tissues. This study aims to characterize irradiated hard tissues and correlate the depth reached by the heat of the laser irradiation with the obtained images. For this, thirty 8 mm2 blocks of bovine enamel and bovine root dentin, were randomized into 6 groups: G1- enamel untreated; G2- enamel irradiated with Nd:YAG micropulsed laser (1064 nm, 10 Hz- Lares Research R°) using a coal paste as photoabsorber; G3- enamel irradiated with Nd:YAG nanopulsed laser (1064 nm, 20 Hz, Brilliant, Quantel Laser) using a coal paste as photoabsorber; G4-G6 (bovine root dentin in the same conditions of treatment of G1-G3). The measurements were performed in three di®erent depth regions of the cubic shaped samples: region A- left corner above of the sample, region B- middle of the sample and Region C- right corner below of the sample. The area under the phosphate, carbonate, amide I, II, and III bands were calculated. The Raman spectra of the Nd:YAG irradiated samples detected a reduction in all the organic components of the enamel after laser irradiation. Previous studies of our group demonstrated that di®erences in carbonate substitution in the apatite lattice are related to the apatite instability and demineralization susceptibility. Considering that carbonate free apatite is less susceptible to acid attack, the results of this study suggest that Nd:YAG lased enamel can be more resistant to caries, in a direct correlation to the thickness of the treated area. It was found that for micropulsed Nd:YAG laser, the heat induced depth was 10 § 2 ¹m and for nanopulsed laser the heat induced depth was 8 § 3 ¹m. So, it is possible to correlate the heat penetration depth of the laser irradiation with the images obtained by the confocal Raman.

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  • IPEN-DOC 26005

    ZAMATARO, CLAUDIA B. ; KUCHAR, NIELSEN G. ; SCAPIN, MARCOS A. ; ZANINI, NATHALIA ; CASTRO, PEDRO ; RABELO, THAIS F. ; JUVINO, AMANDA C. ; ZEZELL, DENISE . Calcium analysis from gamma sterilized human dentin and enamel. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42nd, 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019.

    Abstract: Gamma radiation changes the patients0 oral cavity undergoing radiotherapy. Alterations cause an unsaturated environment of calcium and phosphate into the oral cavity. After approval of the Ethics Committee, 20 hu- man teeth were sectioned to obtain 20 human enamel and 20 dentin samples, polished plane. Samples were randomized in the irradiated group and control group (untreated). Then, the treatment group was irradiated with 25:0 kGy at the 60Co multipurpose irradiator. After the gamma irradiation, Fourier Transformed Infrared Spectroscopy (FTIR), percentage of surface microhardness loss (%SMHL) and Scanning Electron Microscopy (SEM) were performed. At the end, acidic biopsies were performed to quantify the concentration of calcium present in the samples. FTIR showed that the molecular structure of HA of the enamel is similar to the non- irradiated, with no formation or loss of molecular compounds occurring. X-ray °uorescence at enamel samples was performed. Microscopic morphological analysis did not shown signi¯cant di®erences. Surface microhardness is an indirect indicator of the mineral content of the samples. The mean obtained was 258:2 (38:8) KHN within the hardness spectrum of the healthy natural enamel. The compounds present in the samples and the values of the ratios of Calcium and Phosphate oxides and relation between the elements Calcium and Phosphorus. The ratio of the most stable oxides shows a variation with linear correlation. In the enamel, the ratio (Ca/P) shows a change in the elemental content with linear correlation (R2 = 1). These ¯ndings lead us to a new hypothesis of behaviour of the HA crystal versus gamma irradiation. On the other hand for the irradiated dentin, the Knoop hardness number was within the range of the spectrum similar to that of natural dentin of human origin. X-ray °uorescence shows that irradiated dentin has great similarity with natural dentin from the point of view of chemical composition. SEM analyses showed that there was no thermal damage or interprismatic morpho- logical changes in the hydroxyapatite structure of human dental dentin outside the buccal environment when using doses of gamma irradiation up to 25 kGy.

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  • IPEN-DOC 26004

    OLIVEIRA, R.R. ; FUJIMOTO, T.G. ; MUCCILLO, E.N.S. . Estudo da densificação, estrutura e microestrutura do SrTiO3 contendo praseodímio. In: CONGRESSO BRASILEIRO DE CERÂMICA, 63rd, 4-7 de agosto, 2019, Bonito, MS. Resumo... 2019.

    Abstract: Materiais com estrutura do tipo perovsquita apresentam interessantes propriedades físicas que podem ser escritas em termos de distorções estruturais associadas a mudanças na composição química juntamente com os defeitos existentes na rede cristalina. Isso permite uma ampla faixa de aplicação em dispositivos eletrônicos tais como: supercacitores; dispositivos para armazenamento de energia; atuadores piezoelétricos; dentre outras. Particularmente, os materiais baseados em titanato de estrôncio (STO) tem sido intensamente estudados, sobretudo sua estrutura e microestrutura. A estrutura cristalina pode ser alterada por meio de substituições químicas com a introdução de aditivos. Neste trabalho, foi realizado o estudo estrutural e microestrutural do STO contendo diferentes teores de praseodímio. As amostras foram preparadas mediante mistura de óxidos convencional, partindo do STO e Pr6O11 comerciais. As amostras de STO contendo 0,025; 0,050; 0,075 e 1% mol de Pr foram conformadas por compactação uniaxial e isostática e sinterizadas à 1500 ºC durante 6 horas. A caracterização das amostras sinterizadas foi realizada mediante densidade aparente pelo método de Arquimedes, microscopia eletrônica de varredura (MEV) para o estudo da morfologia superficial (em amostras polidas) e difração de raios X para determinação da estrutura por meio de refinamento pelo método de Rietvield. Os resultados mostram que as amostras apresentam densidade próxima à teórica (95%), com exceção da contendo 1% mol do aditivo (83%). As micrografias obtidas por MEV mostram que houve um tênue aumento no tamanho médio de grãos de 28 m em STO para 30 m nas amostras contendo praseodímio. Nos parâmetros de rede obtidos pelo refinamento dos padrões de difração de raios X foi observado que as amostras foram cristalizadas no sistema cúbico e não possuem alterações significativas nas diferentes proporções de aditivos variando de 3,904 à 3,906 Å.

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  • IPEN-DOC 26003

    MUCCILLO, E.N.S. ; FUJIMOTO, T.G. ; SOUZA, J.P. . Avaliação da microestrutura do SrTiO3 comercial e obtido por reação em estado sólido. In: CONGRESSO BRASILEIRO DE CERÂMICA, 63rd, 4-7 de agosto, 2019, Bonito, MS. Resumo... 2019.

    Abstract: Materiais com estrutura do tipo perovskita tem diversas aplicações na indústria eletro-eletrônica, como por exemplo, em dispositivos eletrônicos, capacitores, ou transdutores piezoelétricos. Dentre os principais materiais utilizados com esse tipo de estrutura que vem sendo amplamente estudado destaca-se o titanato de estrôncio. A microestrutura deste tipo de perovskita é essencial para obtenção das propriedades de interesse para estas aplicações. Portanto, neste trabalho foi realizado o estudo da microestrutura do titanato de estrôncio por meio de microscopia eletrônica de varredura e de força atômica. As amostras foram preparadas utilizando o titanato de estrôncio obtido por meio de reação em estado sólido e comercial. Os compactos cerâmicos foram sinterizados a 1500ºC por 6 h de patamar. As amostras foram caracterizadas por meio de densidade, microscopia eletrônica de varredura, espectroscopia de energia dispersiva (EDS) e microscopia de força atômica. Os resultados mostraram que as amostras sintetizadas apresentaram regiões com forma triangular onde foi identificada uma alta concentração de Sr por meio de EDS. A amostra produzida a partir do material comercial apresentou grãos heterogêneos e através do mapa de adesão foi possível observar texturas diferentes dos grãos. As amostras possuem densidades acima de 99% da densidade teórica.

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  • IPEN-DOC 26002

    FERREIRA, L.A.S. ; REIS, S.L. ; MUCCILLO, E.N.S. . Estabilização de fase e microestrutura da zircônia-céria obtida por reação em estado sólido. In: CONGRESSO BRASILEIRO DE CERÂMICA, 63rd, 4-7 de agosto, 2019, Bonito, MS. Resumo... 2019.

    Abstract: Materiais cerâmicos à base de zircônia estabilizada na fase tetragonal têm sido extensivamente estudados e propostos para diversas aplicações devido suas destacadas propriedades termomecânicas. A zircônia contendo 12 mol% em céria (12Ce-TZP) possui estrutura tetragonal, alta resistência à fratura e estabilidade térmica. Este trabalho tem como objetivo verificar o efeito da sinterização na estabilização da fase tetragonal e na microestrutura da 12Ce-TZP preparada por reação em estado sólido. As amostras de 12Ce-TZP foram preparadas pelo método de mistura dos óxidos reagentes seguida de sinterização em diversas temperaturas. As fases cristalinas, densificação e microestrutura foram analisadas por difração de raios X, medidas de densidade hidrostática e microscopia eletrônica de varredura, respectivamente. O teor de fase monoclínica foi quantificado utilizando o método dos polimorfos. Amostras com fase única tetragonal foram obtidas para sinterizações a 1400 °C e densidades próximas à teórica (> 99%) para amostras sinterizadas a 1500 °C.

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  • IPEN-DOC 26001

    GROSSO, R.L. ; MUCHE, D.N.F.; CASTRO, R.H.R.; MUCCILLO, E.N.S. ; DILLON, S.. Testes mecânicos de nano-compressão por MET in-situ em zircônia estabilizada. In: CONGRESSO BRASILEIRO DE CERÂMICA, 63rd, 4-7 de agosto, 2019, Bonito, MS. Resumo... 2019.

    Abstract: Zircônia-escândia (ScZ) possui grande interesse tecnológico para aplicação como eletrólito sólido devido a sua maior condutividade iônica entre os materiais à base de zircônia. No entanto, as propriedades mecânicas de ScZ são pouco conhecidas, principalmente, devido à instabilidade de fase, que limita a aplicação desse material. Considerando que a estrutura cúbica tipo fluorita é dependente do tamanho dos grãos e pode ser estabilizada em nanoescala, nesse trabalho, foram investigadas as propriedades mecânicas de amostras densas de ScZ nanoestruturadas. Amostras ScZ foram obtidas por sinterização assistida por campo elétrico, pelo método, recentemente proposto, que utiliza punções deformáveis. Esse método de sinterização inibe o crescimento de grãos devido às baixas temperaturas utilizadas e elimina a porosidade residual devido à aplicação de alta pressão. Amostras de ZrO2 contendo teor molar de 10% de Sc2O3 foram sintetizadas pelo método de coprecipitação de hidróxidos, calcinadas e sinterizadas em baixas temperaturas (700 a 860 °C) e elevadas pressões (1,4 e 2 GPa). Foram produzidas amostras cúbicas policristalinas com tamanho médio de grãos entre 8 e 17 nm. Testes mecânicos de compressão foram realizados por microscopia eletrônica de transmissão in situ em nanopilares de seção transversal quadrada preparados por feixe de íons focalizado. As propriedades mecânicas foram avaliadas em função do tamanho médio de grãos. Foi observada uma considerável melhoria nas propriedades mecânicas em amostras nanoestruturadas de ScZ. O limite de escoamento aumentou de 1,9 para 4,9 GPa com a diminuição do tamanho médio de grãos de 50 para 13 nm. Os valores de limite de escoamento seguem a relação de Hall-Petch para amostras com tamanho médio de grãos de até 13 nm, onde ocorre a inversão na relação de Hall-Petch.

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  • IPEN-DOC 26000

    REIS, S.L. ; CARVALHO, S.G.M. ; MUCCILLO, E.N.S. ; MUCCILLO, R. . Densificação de céria-samária por meio de sinterização sem pressão assistida por campo elétrico AC. In: CONGRESSO BRASILEIRO DE CERÂMICA, 63rd, 4-7 de agosto, 2019, Bonito, MS. Resumo... 2019.

    Abstract: A solução sólida céria-samária é uma das principais candidatas para aplicação como eletrólito sólido em células a combustível de óxido sólido, devido sua alta condutividade iônica em temperaturas intermediárias de operação (500-750 °C). Um dos problemas ainda não solucionados é sua relativamente baixa sinterabilidade. Altas temperaturas de sinterização, em geral acima de 1500 °C, são necessárias para obter densificação com impermeabilização a gases (> 92% da densidade teórica). Em altas temperaturas pode ocorrer redução de Ce4+ para Ce3+, com consequente aumento na condutividade eletrônica. No entanto, a utilização de métodos de sinterização não convencionais como a sinterização sem pressão assistida por campo elétrico é uma das estratégias para diminuir a temperatura de sinterização e otimizar as propriedades. Este trabalho tem como objetivo avaliar os efeitos do método de sinterização isotérmica assistida por campo elétrico AC durante o patamar em uma temperatura fixa. Foram realizados experimentos variando campo elétrico, tempo de aplicação do campo e limite de corrente elétrica. Os resultados mostraram que é possível densificar a céria-samária em temperaturas inferiores às convencionais por meio de sinterização sem pressão assistida por campo elétrico. O aumento do valor do campo elétrico promoveu diminuição nos valores de resistividade intragranular e intergranular. O aumento na temperatura de aplicação do campo elétrico resultou em amostras com condutividade elétrica maior em relação à amostra sinterizada convencionalmente em 1500 °C/2 h.

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  • IPEN-DOC 25999

    REIS, S.L. ; MUCCILLO, E.N. . Influence of calcium addition on the electrical conductivity of samarium doped ceria. In: INTERNATIONAL CONFERENCE & EXPOSITION ON ADVANCED CERAMICS AND COMPOSITES, 42nd, January 21-26, 2018, Daytona Beach, Florida, USA. Abstract... Westerville, OH, USA: The American Ceramic Society, 2018. p. 97-97.

    Abstract: Ceria-based ceramics have been proposed to be used as solid electrolyte in solid oxide fuel cells operating at intermediate (500-750°C) temperatures, due to their high ionic conductivity. Samarium ion is recognized as one of the most reliable dopants for cerium oxide because of its lower association energy with oxygen vacancies. One challenge posed to ceria-based solid electrolytes is how to improve sinterability, avoiding high temperatures to attain good densification. Thermal treatments at high temperatures may reduce Ce4+ to Ce3+, favoring electron transport and generation of micropores in the sintered electrolyte. Introduction of a second additive is a usual approach to overcome these constraints. In this work calcium ion was chosen as the second additive. Sm0.2-xCaxCe0.8O1.9-x/2 compositions, with x = 0, 0.025, 0.05, 0.1, 0.15 and 0.2, were prepared by solid-state reaction, and the influence of the additive content on densification and ionic conductivity was investigated. All compositions were found to have cubic fluorite-type structure. The optimal composition was Sm0.175Ca0.025Ce0.8O1.888, which showed a relative density of 97%, single phase and higher ionic conductivity than the Sm0.2Ce0.8O1.9 parent electrolyte.

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  • IPEN-DOC 25998

    SOUZA, J.P. ; MUCCILLO, E.N. . Ionic conductivity and phase stabilization in zirconia-scandia-europia. In: INTERNATIONAL CONFERENCE & EXPOSITION ON ADVANCED CERAMICS AND COMPOSITES, 42nd, January 21-26, 2018, Daytona Beach, Florida, USA. Abstract... Westerville, OH, USA: The American Ceramic Society, 2018. p. 97-97.

    Abstract: Zirconia-8 mol% yttria is widely used as electrolyte in solid oxide fuel cells, due to its high ionic conductivity and good mechanical and chemical properties. Nevertheless, scandia-stabilized zirconia is recognized as exhibiting the highest ionic conductivity among zirconia-based solid electrolytes. Stabilization of the high symmetry and high ionic conductivity cubic phase in this system is non-trivial. Introduction of a second additive (or dopant) is a usual strategy to overcome that constraint. In this work, europium oxide has been added to 10 mol% scandia-stabilized zirconia (10ScSZ) aiming full stabilization of the cubic structure at room temperature. The influence of europia addition (up to 1.25 mol%) on phase stabilization and ionic conductivity of 10ScSZ was investigated by differential scanning calorimetry and impedance spectroscopy. The higher is the fraction of europia into solid solution the lower is the temperature of the endothermic event due to phase transition. The cubic phase is fully stabilized at room temperature for 1 mol% europia addition. The grain and total ionic conductivity show typical Arrhenius behavior. The magnitude of the total conductivity increases with increasing europia addition.

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  • IPEN-DOC 25997

    MUCCILLO, R. ; MUCCILLO, E.N. . Non-conventional joining of a ceramic solid oxide fuel cell to a metallic interconnect. In: INTERNATIONAL CONFERENCE & EXPOSITION ON ADVANCED CERAMICS AND COMPOSITES, 42nd, January 21-26, 2018, Daytona Beach, Florida, USA. Abstract... Westerville, OH, USA: The American Ceramic Society, 2018. p. 208-208.

    Abstract: Co-generation of energy (heat and electric power) with ceramic solid oxide fuel cells requires consolidation of anode-electrolyte- cathode single cells with a dense electrolyte and porous anode and cathode. The consolidation is usually achieved by sintering the three-layer single cells according to special procedures to produce flat square shape cells. Non-conventional consolidation of several ceramic materials used in energy-conversion devices has been done with success in several ceramic materials by electric field-assisted pressureless sintering, producing porous or dense components. The same approach has been tried in a flat single solid oxide fuel cell with yttria-stabilized zirconia solid electrolyte, lanthanum strontium manganite cathode and yttria-stabilized zirconia/nickel oxide anode with promising results, opening new routes for future low cost production of these devices. There is still a challenge in using that technique for joining ceramic single cells to metallic interconnector, one of the research areas of Dr. Mrityunjay Singh. Our efforts now are directed to carry out experiments aiming the joining of ceramic single cells to metallic interconnects by application of electric fields.

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