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  • IPEN-DOC 25027

    BUSTILLOS, OSCAR V. . A espectrometria de massas e a química analítica. Revista Analytica, v. 16, n. 96, p. 36-37, 2018.

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  • IPEN-DOC 25023

    LARA, J.A.C.; COUTO, C.P. ; COLOSIO, M.A.; ROSSI, J.L. ; ABBADE, L.M.. Influence of spot welding parameters on Al-Si coated 22MnB5 for automotive application. SAE Technical Paper, n. 2017-36-0225, p. 1-6, 2017. DOI: 10.4271/2017-36-0225

    Abstract: The application of press hardening steels (PHS) Al-Si coating has been increasing in body in white vehicles as an approach to meet the demands of safety and CO2 reduction regulations. The vehicle structures with PHS largely depend on the integrity and the mechanical performance of the spots weld. During the spot welding process, intermetallic phase may appear in function of the chemical composition of the steel and coating. One of these intermetallics is the Fe-Al phase which brittleness decreases the strength of the weld joint. In this study, resistance spot welding (RSW) experiments were performed in order to evaluate the influence of the welding parameters of single-lap joints PHS - 22MnB5 steel grade. Welded samples of the Al-Si coated PHS steel as received, i.e., before any heat treatment and stamping, were evaluated by means of glow discharge optical emission spectroscopy (GDOES) technique that allows a quick and accurate evaluation of the chemical composition profile along the spot weld thickness. The GDOES results showed that the squeeze welding parameter has the higher influence on cupper diffusion at the Al-Si-Fe layer. The pre-burn current and welding current showed the higher influences in Fe-Al diffusion. The pulse technique and post-heat treatment had had the lower influences in Fe-Al diffusion.

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  • IPEN-DOC 25013

    GOMES, MAURILIO P. ; SANTOS, IGOR ; COUTO, CAMILA ; MUCSI, CRISTIANO ; ROSSI, JESUALDO L. ; COLOSIO, MARCO. P/M valve seat inserts: air quenching and characterization. SAE Technical Paper, n. 2017-01-5014, 2017. DOI: 10.4271/2017-01-5014

    Abstract: This work consists of evaluating the influence of heat treatment on sintered valve seat insert (VSI) obtained with two different highspeed steels powders and one tool steel: AISI M3:2, AISI M2 and AISI D2, respectively. The high-speed / tool steel powders were mixed with iron powders and additives such as manganese sulphide, zinc stearate, graphite and niobium carbide. All the high-speed / tool steel powders had its particle size distribution and morphology analyzed. The heat treatment of the VSI consisted of air quenching followed by double tempering it in seven different and equidistant temperatures, ranging from 100 °C until 700 °C. A data acquisition system with a thermocouple type k attached to the samples was used to determine the air-quenching cooling rate. The mechanical and physical properties measurements were carried out, i.e., apparent density, apparent hardness and crush radial strength. The microstructural evaluation consisted of etching the VSI and then analyzing it using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that the VSI obtained with the AISI M3:2 and M2 high-speed steel powders mixtures showed the best results regarding its apparent hardness and crush radial strength after air quenching and double tempering it at 600 °C.

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  • IPEN-DOC 24930

    GONCALVES, KARINA de O.; VIEIRA, DANIEL P. ; COURROL, LILIA C.. Synthesis and characterization of aminolevulinic acid gold nanoparticles: Photo and sonosensitizer agent for atherosclerosis. Journal of Luminescence, v. 197, p. 317-323, 2018. DOI: 10.1016/j.jlumin.2018.01.057

    Abstract: Photodynamic and sonodynamic therapies (PDT and SDT, respectively) are emerging as new atherosclerosis treatments. The subsequent generation of free radicals by activated photo and sonosensitizers can lead to apoptotic cell death. The use of gold nanoparticles (AuNPs) as the vehicle for a sensitizer delivery improves reactive oxygen species formation and sensitizer performance. In this study gold nanoparticles functionalized with polyethylene glycol (PEG) were synthesized mixing δ-aminolevulinic acid (ALA) with tetrachloroauric (III) acid in milliQ water solution followed by photo reduction with 300W xenon lamp. The synthesized ALA:AuNPs were characterized by UV/vis optical absorption, zeta potential and electron microscopy. The mean particle size of spherical ALA:AuNP was ~ 18 nm, with a polydispersity index of 0.437. Singlet oxygen generation efficiency was measured using the trap molecule 1,3-diphenylisobenzofuran. ALA:AuNPs and DPBF were irradiated with 590 nm LED, or pulse ultrasound irradiation (1 W/cm2 with 1.0 MHz), and consumption of the DPBF was monitored over time by the absorption and emission spectra. The results showed that he gold nanoparticles generate singlet oxygen during light and ultrasound irradiations. THP-1 cells differentiated into macrophages cytotoxicity test were described and was found the half maximal inhibitory concentration (IC50) values ~ 36 nM for ALA:AuNPs. Increase in the fluorescence intensity of PpIX extracted from macrophages incubated with ALA:AuNPs indicating stable encapsulation of ALA into gold nanoparticles and further conversion to PpIX. The potential use of ALA:AuNps as a sensitizer for photo and sonodynamic therapies were investigated. ALA:AuNPs mediated SDT was more effective than PDT. SDT with ALA:AuNPs induced the reduction of macrophage viability in ~ 87,5% in only 2 min. The mechanism underlying SDT-induced apoptosis involves the generation of singlet oxygen. The results indicate that ALA:AuNPs can be used as a novel photo and sonosensitizer for atherosclerosis.

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  • IPEN-DOC 24926

    AZEVEDO, LUCIANA C. de; SA, ALESSANDRA S.C. de; ROVANI, SUZIMARA ; FUNGARO, DENISE A. . Propriedades do amido e suas aplicações em biopolímeros. Cadernos de Prospecção, v. 11, n. Edição Especial, p. 351-358, 2018. DOI: 109771/cp.v11nesp.23173

    Abstract: O uso de amido pelos seres humanos remonta ao Egito antigo, onde papiros datados de 4000 a.c. eram elaborados com amido de trigo. Este carboidrato polimérico é constituído por unidades de glicose que se ligam formando estruturas de amilose e amilopectina, cuja proporção de cada uma dessas frações irá conferir características específicas, atribuindo diferentes aplicações comerciais a esta substancia. Muitos estudos estão sendo conduzidos para encontrar aplicações nobres para o amido, como por exemplo, o melhoramento das propriedades de materiais pela incorporação deste carboidrato como substrato polimérico, especialmente com o intuito de serem empregados em substituição ao plástico. Em relação a isso, pesquisas têm sido realizadas envolvendo a combinação com outros hidrocolóides, adição de novos plastificantes, nanocompósitos e polímeros inorgânicos na obtenção da solução filmogênica com o amido, assim como estão sendo desenvolvidas novas tecnologias de extrusão e secagem dos filmes, incluindo aplicação de radiação gama. O objetivo desta revisão foi apresentar as principais características e o avanço no uso de amido como polímero em filmes biodegradáveis e o interesse da comunidade científica e industrial por essa tecnologia. A prospecção revelou que, além de estar em ascensão desde 1990, a tecnologia de obtenção de biopolimeros está sendo intensivamente aprimorada por países como a China e EUA.

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  • IPEN-DOC 24870

    LINO, JULIANA dos S. ; AQUINO, AFONSO R. de . Proposta de classificação de brownfields. OLAM - Ciência & Tecnologia, v. 1, n. 1-2, p. 1-23, 2017.

    Abstract: Brownfields são uma realidade nas metrópoles. Áreas que foram contaminadas por atividades industriais, depósito irregular de resíduos ou de substâncias tóxicas, apresentam dificuldade em acompanhar as mudanças de uso e ocupação do solo, comuns nas dinâmicas da sociedade. Os processos de desindustrialização nas metrópoles resultam na identificação de um número crescente de brownfields. Considerando que as formas de gerenciamento e refuncionalização são temas contemporâneos, que impactam diversas áreas, como meio ambiente, desenvolvimento urbano e saúde pública, foi proposta uma metodologia de classificação dos brownfields, analisando suas especificidades, pois as áreas apresentam variações entre si. Foram selecionados atributos, que descrevam a qualidade ambiental da área e, por meio destes, as áreas foram classificadas em seis grupos distintos. A classificação dos brownfields pode auxiliar a melhor compreensão acerca destas áreas, com suas particularidades bem descritas e pode ser uma importante ferramenta na tomada de decisão sobre empreendimentos e o planejamento urbano.

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  • IPEN-DOC 24868

    ENGERROFF, JULIANO A.B.; KELLER, FREDERICO O.; LOPES, LEONARDO U. ; MASCHERONI, ARTHUR A.; TAKIISHI, HIDETOSHI ; WENDHAUSEN, PAULO A.P.. d-HDDR processing of Nd-Fe-B based alloys to obtain highly anisotropic nanocrystalline powders. Materials Science Forum, v. 899, p. 563-566, 2017. DOI: 10.4028/www.scientific.net/MSF.899.563

    Abstract: The HDDR (hydrogenation-disproportionation-desorption-recombination) process is an established powder metallurgy route to obtain Nd–Fe–B nanocrystalline powders for bonded magnets manufacturing. Therefore, both conventional (c-HDDR) and dynamic HDDR (d-HDDR) processes has been investigated to obtain Nd-Fe-B-based powders with different characteristics. Magnetic properties were measured by means of a hysteresisgraph and the powder obtained by d- HDDR showed strong anisotropy, allowing a Br of 1.1 T in the bonded magnet, whereas c-HDDR powder was isotropic with a Br of 0.6 T. Microstructural changes were characterized by X-ray diffraction (DRX) and scanning electron microscopy (SEM). X-ray patters of anisotropic powders made by d-HDDR showed high intensity reflection peaks indexed as (004), (105) and (006) planes in the aligning direction, due the texture inducement in c-axis of the main phase (Nd2Fe14B). However, SEM micrographs of c-HDDR powder showed a more homogeneous microstructure, with grain size of ~300 nm, when compared to d-HDDR powder that ranged from 300 nm to 500 nm. This difference is assumed to be the cause of lower intrinsic coercivity found in the c-HDDR powder.

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  • IPEN-DOC 24867

    MENDES, MARCIO W.D. ; MENDES, NARAYANNA M.F. ; BRESSIANI, ANA H. de A. ; BRESSIANI, JOSE C. . Effect of NbH Particle size and cooling type on the microstructure, phase composition and microhardness of Ti-20Nb-20Zr alloy. Materials Science Forum, v. 899, p. 243-247, 2017. DOI: 10.4028/www.scientific.net/MSF.899.243

    Abstract: Titanium alloys are widely used as implants in orthopedics and dentistry due to their properties such as high strength, corrosion resistance, biocompatibility and good fatigue resistance. Alloys composed of non-toxic elements, like Nb and Zr, provide lowest Young’s modulus with values near to human bone modulus. The goal of this work was to study the effect of NbH particle size and cooling type on the microstructure, phase composition and microhardness of Ti-20Nb-20Zr alloy. The powders were produced by hydrogenation method. Two different powders of NbH were prepared: powders comminuted (C) and comminuted followed by milling (C+M). After, the alloy powders were milling and homogenizated for 6 h / 300 rpm and sintered at 1300 °C / 3h followed furnace cooling. Afterward, the specimens were treated at 1000 °C / 1 h and cooling in air and water. The samples were characterized by XRD, SEM and Vickers microhardness. The results showed that the alloy is classified as α + β. Vickers microhardness of Ti-20Nb-20Zr ranged between 680-700 and 540-600 HV from alloys prepared with NbH-comminuted and NbH comminuted + milled, respectively. Results indicated that NbH agglomerate behave as barriers for the sintering process of the alloy.

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  • IPEN-DOC 24866

    MACHADO, GLAUSON A.F. ; ROCHA, ROSA M.; BRESSIANI, ANA H.A. . Composites obtained from alumina and polymer derived ceramic. Materials Science Forum, v. 912, p. 141-146, 2018. DOI: 10.4028/www.scientific.net/MSF.912.141

    Abstract: Alumina-mullite composites with low shrinkage can be made by reaction bond using mixtures of alumina, aluminum and silicon carbide. In this work, an alternative route is used to produce alumina composites with low shrinkage. Here alumina samples containing additions of 10 and 20 wt% of a preceramic polymer were warm-pressed and treated in the range of 900 -1500°C to produce alumina based composites. The obtained composites were analyzed by linear shrinkage and compared to pure alumina samples sintered at the same temperature range. It were also evaluated the density variation and crystalline phases formed during heat treatment of alumina composites. Results showed that alumina-silicon oxycarbide and alumina-mullite composites were obtained with lower shrinkage than pure alumina samples.

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  • IPEN-DOC 24865

    PIERETTI, EURICO F. ; PILLIS, MARINA F. . Electrochemical behavior of Nb2O5 films produced by magnetron sputtering. International Journal of Electrochemical Science, v. 13, n. 8, p. 8108-8115, 2018. DOI: 10.20964/2018.08.78

    Abstract: Metallic engineering materials generally form passive films on their surfaces and therefore are prone to localized corrosion, usually characterized by the occurrence of pits. 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 paper is to investigate the influence of Nb2O5 coatings on the electrochemical behavior of AISI 316 stainless steel. The films were deposited for 15, 30 and 50 minutes by using DC magnetron sputtering technique. The corrosion resistance was evaluated by monitoring the open circuit potential (OCP), the electrochemical impedance spectroscopy (EIS) and the linear potentiodynamic polarization (LP) in an aqueous 0.1 M H2SO4 electrolyte at 25 °C. Electrochemical tests revealed a more capacitive behavior of the Nb2O5-coated specimens when compared to the uncoated one. This fact indicates that the coated samples are less susceptible to corrosion. The deposited films show a protective character 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 24857

    SANTOS, JONNATAN J. ; LEAL, JESSICA ; DIAS, LUIS A.P. ; TOMA, SERGIO H.; CORIO, PAOLA; GENEZINI, FREDERICO A. ; KATTI, KATTESH V.; ARAKI, KOITI; LUGAO, ADEMAR B. . Bovine serum albumin conjugated gold-198 nanoparticles as model to evaluate the damage caused by ionizing radiation to biomolecules. ACS Applied Nano Materials, 2018. DOI: 10.1021/acsanm.8b01174

    Abstract: Gold nanoparticles (AuNPs) have several applications including in medicine. Considering cancer as one of the most common diseases for men and women, new treatments and more specific and effective drugs, which cause less side effects, have been actively pursued. Among them, gold-198 can be engineered as theranostic agents, working as contrast (exploiting gamma emission) and treatment agents (beta emission). Accordingly, a new procedure for the production of 14 nm diameter radioactive citrate protected gold-198 nanoparticles, that were then conjugated with bovine serum albumin utilizing 3-mercaptopropionic acid directly bound to AuNPs surface as anchoring groups, generating fully dispersible nanoparticles in aqueous media, are described. The effect of gamma and beta radiation on grafted BSA was evaluated by direct irradiation of the corresponding cold material and comparing with the damage caused on BSA grafted gold-198 nanoparticles prepared from a neutron activated gold foil. The investigation by fluorescence and Raman spectroscopy indicated that the damage to BSA chromophore groups is proportional to the dose (from 0.1 to 1 kGy) and that chromophores groups close to the particle surface are more prone to damage. Gold-198 nanoparticles conjugated with bovine serum albumin showed that process is much more localized next to nanoparticles surface since each gold core acts as a punctual radiation source. In short, AuNPs can enhance the damage caused by irradiation of cold nanoparticles and AuNPs@MPA-BSA is a suitable model to probe the effect of gamma and beta emitter on biomolecules. Furthermore, the strategy of diluting the gold-198 with cold gold atoms was shown to be suitable to control the activity of 198AuNPs aiming medical applications, since the damage to BSA was found to be proportional to the relative concentration of gold-198.

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  • IPEN-DOC 24686

    LEVY, D.S. ; SORDI, G.M.A.A. . Web-based system for radiological protection programs: a repository for research, consultation and information. Brazilian Journal of Radiation Sciences, v. 03, n. 1A, p. 01-10, 2015. DOI: 10.15392/bjrs.v3i1A

    Abstract: In order to establish a Radiation Protection Plan or a Radiation Emergency Plan, Brazilian facilities should take into account all procedures based on national and international guidelines and recommendations. This information can be found in several documents published by different organizations over the past decades: the International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA) and Comissão Nacional de Energia Nuclear (CNEN). Therefore, this project aims the informatization of the radiological protection programs in a single system in order to offer unified programs and inter-related information in Portuguese, providing Brazilian facilities a complete repository for research, consultation and information, combining computer technology and radiological protection in order to enhance the best benefits from information technology. This research work includes programs about: (1) Monitoring of Workplace (Monitoring for External Radiation, Monitoring for Surface Contamination, Monitoring for Air Contamination) and (2) Individual Monitoring (Monitoring of External Exposure and Monitoring of Internal Exposure, Monitoring for Skin and Clothing). WEB platform tools and functionalities were developed according to target public needs, regarding new possibilities of media, mobile access, and information sharing. The servers processing power added to the technology of relational databases allow to integrate information from different sources, enabling complex queries with reduced response time. Moreover, taking into account this is a pioneer project with the prospect of long-term use, the challenge involves the combination of multiple computer technologies that allows a robust, effective and flexible system, which can be easily adapted to future technological innovations.

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  • IPEN-DOC 24864

    STREFEZZA, CLAUDIA ; AMARAL, MARCELLO M.; QUINTO JUNIOR, JOSE ; GOUW-SOARES, SHEILA C.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M. . Effect of 830 nm diode laser irradiation of root canal on bond strength of metal and fiber post. Photomedicine and Laser Surgery, p. 1-6, 2018. DOI: 10.1089/pho.2017.4378

    Abstract: Objective and background: The correct selections of the cementing agent, the endodontic post material and placement protocol are critical to provide an increased longevity of the teeth that went through endodontic treatment. The irradiation with diode laser before post cementation, can promote an antimicrobial effect. However, there is a lack of information about the effect of 830 nm diode laser on the post bond strength. This study analyzed the effect of dentin root canal irradiation with high-intensity diode laser, at 830 nm, operating in continuous or pulsed mode, on the retention of metal or fiber posts, cemented with self-etching resinous composite (Panavia F) and zinc phosphate cement (ZnPO4). Materials and methods: Human roots were irradiated with diode laser (continuous and pulsed mode). The fiber posts were luted with Panavia F and the metal posts with Panavia F or ZnPO4 cement. Specimens were sectioned into three sections (cervical, middle, and apical). The bond strength was measured by a push-out mechanical analysis. For the statistical analysis, a three-way ANOVA test was applied following a Tukey's pairwise comparison with a significance level of p = 0.05. Results: The irradiated groups presented higher bond strength compared with nonirradiated group (p < 0.05), and the cervical and middle thirds presented higher on bond strength than the apical. The association of metal post and Panavia F presented higher bond strength when irradiated on continuous mode (p < 0.05). Fiber post and Panavia F presented higher bond strength associated to pulsed mode. The mode seems not to make a significant difference. Conclusions: These results corroborate the importance of the post bond to dentin and root canal debris removal to increase the tooth longevity. It was shown that the dentin to post bond strength were enhanced by the diode laser irradiation either on continuous or pulsed modes.

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  • IPEN-DOC 24863

    BERECZKI, ALLAN ; LOPEZ, MARCIO A.P.A. ; WETTER, NIKLAUS U. . Dynamically stable Nd:YAG resonators with beam quality beyond the birefringence limit and pumping of a singly resonant optical parametric oscillator. Optics Letters, v. 43, n. 4, p. 695-698, 2018. DOI: 10.1364/OL.43.000695

    Abstract: A simple, reliable, linearly polarized laser source with very high beam quality is demonstrated using standard diode-side-pumped Nd:YAG modules. The laser produced 30 W of output power with beam quality factor 𝑀2<1.15 over the entire range of input powers and beam quality of 1.02 at the laser operation point. This is, to our knowledge, the highest beam quality for a dynamically stable high-power laser that uses an optically isotropic crystal. The laser was used as a pump source for an optical parametric oscillator based on a periodically poled lithium niobate, producing wavelength in the 1.5–3.8 μm range.

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  • IPEN-DOC 24862

    GEONMONOND, RAFAEL S.; QUIROZ, JHON; ROCHA, GUILHERME F.S.R.; OROPEZA, FREDDY E.; RANGEL, CLARA J.; RODRIGUES, THENNER S. ; HOFMANN, JAN P.; HENSEN, EMIEL J.M.; ANDO, ROMULO A.; CAMARGO, PEDRO H.C.. Marrying SPR excitation and metal–support interactions: unravelling the contribution of active surface species in plasmonic catalysis. Nanoscale, v. 10, n. 18, p. 8560-8568, 2018. DOI: 10.1039/c8nr00934a

    Abstract: Plasmonic catalysis takes advantage of the surface plasmon resonance (SPR) excitation to drive or accelerate chemical transformations. In addition to the plasmonic component, the control over metal–support interactions in these catalysts is expected to strongly influence the performances. For example, CeO2 has been widely employed towards oxidation reactions due to its oxygen mobility and storage properties, which allow for the formation of Ce3+ sites and adsorbed oxygen species from metal–support interactions. It is anticipated that these species may be activated by the SPR excitation and contribute to the catalytic activity of the material. Thus, a clear understanding of the role played by the SPR-mediated activation of surface oxide species at the metal–support interface is needed in order to take advantage of this phenomenon. Herein, we describe and quantify the contribution from active surface oxide species at the metal–support interface (relative to O2 from air) to the activities in green SPR-mediated oxidation reactions. We employed CeO2 decorated with Au NPs (Au/CeO2) as a model plasmonic catalyst and the oxidation of p-aminothiophenol (PATP) and aniline as proof-of-concept transformations. We compared the results with SiO2 decorated with Au NPs (Au/SiO2), in which the formation of surface oxide species at the metal–support interface is not expected. We found that the SPR-mediated activation of surface oxide species at the metal–support interface in Au/CeO2 played a pivotal role in the detected activities, being even higher than the contribution coming from the activation of O2 from air.

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  • IPEN-DOC 24861

    RUBIO-MARCOS, FERNANDO; DEL CAMPO, ADOLFO; ROJAS-HERNANDEZ, ROCIO E.; RAMIREZ, MARIOLA O.; PARRA, RODRIGO; ICHIKAWA, RODRIGO U. ; RAMAJO, LEANDRO A.; BAUSA, LUISA E.; FERNANDEZ, JOSE F.. Experimental evidence of charged domain walls in lead-free ferroelectric ceramics: light-driven nanodomain switching. Nanoscale, v. 10, n. 2, p. 705-715, 2018. DOI: 10.1039/c7nr04304j

    Abstract: The control of ferroelectric domain walls at the nanometric level leads to novel interfacial properties and functionalities. In particular, the comprehension of charged domain walls, CDWs, lies at the frontier of future nanoelectronic research. Whereas many of the effects have been demonstrated for ideal archetypes, such as single crystals, and/or thin films, a similar control of CDWs on polycrystalline ferroelectrics has not been achieved. Here, we unambiguously show the presence of charged domain walls on a leadfree (K,Na)NbO3 polycrystalline system. The appearance of CDWs is observed in situ by confocal Raman microscopy and second harmonic generation microscopy. CDWs produce an internal strain gradient within each domain. Specifically, the anisotropic strain develops a crucial piece in the ferroelectric domain switching due to the coupling between the polarization of light and the ferroelectric polarization of the nanodomain in the (K,Na)NbO3 ceramic. This effect leads to the tuning of the ferroelectric domain switching by means of the light polarization angle. Our results will help to understand the relevance of charged domain walls on the ferroelectric domain switching process and may facilitate the development of domain wall nanoelectronics by remote light control utilizing polycrystalline ferroelectrics.

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  • IPEN-DOC 24860

    BATISTA, R.M. ; NARANJO, J.F.R.; MUCCILLO, E.N.S. . A versatile software for construction of the master sintering curve. Materials Science Forum, v. 912, p. 240-244, 2018. DOI: 10.4028/www.scientific.net/MSF.912.240

    Abstract: Several models have been developed over the last years to study the microstructure development of ceramic and metal powders during sintering. Among the most utilized methodology one may find the Arrhenius and the so-called Master Sintering Curve (MSC). Both models involve manipulation of a large number of data, and repetitive and time-consuming calculations. In this work, was developed a versatile and friendly-user software for a PC-type computer encompassing both methodologies. The software is flexible allowing for kinetic data evaluation such as the activation energy for sintering and sintering maps. Details of the software along with its application to investigate the sintering process of 10 mol% gadolinia-doped ceria are described.

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  • IPEN-DOC 24859

    ABREU, CAIO P. de ; COSTA, ISOLDA ; MELO, HERCILIO G. de; PEBERE, NADINE; TRIBOLLET, BERNARD; VIVIER, VINCENT. Multiscale electrochemical study of welded al alloys joined by friction stir welding. Journal of the Electrochemical Society, v. 164, n. 13, p. C735-C746, 2017. DOI: 10.1149/2.0391713jes

    Abstract: Friction stir welding (FSW) is an efficient way to join high strength aluminum alloys. However, FSW generates different microstructural areas in contact that may give rise to galvanic couplings, affecting the corrosion resistance of the assembly. In the present work, a multiscale electrochemical study of the 7475-T651 and 2024-T3 aluminum alloys butt-joined by FSW was carried out.Much lower impedances were associated with the FSW affected zones compared to the two aluminum base metals tested individually. Corrosion of the welded system resulted in the establishment of galvanic coupling, shown by local electrochemical impedance spectroscopy (LEIS) measurements, at which the AA7475 behaves anodically with respect to the AA2024. A Zn deposit was observed on the intermetallic particles of the AA2024 after 24 h of immersion in the electrolyte resulting from the galvanic coupling, which seems to reduce the galvanic coupling effects. Such a behavior in combination with LEIS results allowed a description of the galvanic coupling development between two different aluminum alloys (AA2024-T3 and AA7475-T761) butt-welded by FSW as a function of time from the early stage of immersion.

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  • IPEN-DOC 24858

    BARBOSA, ANDREA Q.; SILVA, ROMULO A.S.; PIRES, MARIA A.F. ; LIMA, ALVARO S.; MADI, RUBENS R.; MARQUES, MARIA N.. Elaboration of the water safety plan in a water supply system in the brazilian northeast. International Journal of Development Research, v. 8, n. 2, p. 18810-18815, 2018.

    Abstract: The Water Safety Plan is a tool used to identify, assess and manage health risks related to any water supply system. In order to do so, a study was carried out in a supply system, located in the northeast of Brazil, composed by Fountain Caldas (P1) and Well Cipó (P2), as sources of raw water abstraction, and by the Distribution Reservoir (P3) treated. Water collection, land use and land use assessment and analysis of possible risks were carried out in the vicinity of these three points and in another site (P4) to obtain the treated water. The quality of the raw water was evaluated by the parameters of the Resolution of the Conselho Nacional do Meio Ambiente n° 396/2008 and the water treated according to the parameters of Ordinance nº 2914/2011 of the Ministry of Health. Observing the probability of occurrence of risk and the severity of consequence of the events. Therefore, 17 control points with low rating were detected, and two with moderate rating. Control measures were suggested for each identified critical point, mainly related to water quality monitoring and system maintenance.

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  • IPEN-DOC 24856

    CORREA, EDUARDO L. ; BOSCH-SANTOS, BRIANNA ; FREITAS, RAFAEL S.; POTIENS, MARIA da P.A. ; SAIKI, MITIKO ; CARBONARI, ARTUR W. . Synthesis and atomic scale characterization of Er2O3 nanoparticles: enhancement of magnetic properties and changes in the local structure. Nanotechnology, v. 29, n. 20, 2018. DOI: 10.1088/1361-6528/aab3f8

    Abstract: In the investigation reported in this paper a modified thermal decomposition method was developed to produce very small Er2O3 nanoparticles (NPs). Particles structure, shape and size were characterized by x-ray diffraction and transmission electron microscopy which showed that the synthesis by thermal decomposition under O2 atmosphere produced very small and monodisperse NPs, allowing the investigation of finite-size and surface effects. Results of magnetization measurements showed that the smallest particles present the highest values of susceptibility that decrease as particle size increases. Specific heat measurements indicate that the sample with the smallest NPs (diameter ∼5 nm) has a Néel temperature of 0.54 K. The local structure of particles was investigated by measurements of hyperfine interactions with perturbed angular correlation spectroscopy using 111Cd as probe nuclei replacing the cationic sites. Results showed that the relative population of sites 8b increases in both the core and surface layer of particles.

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  • IPEN-DOC 24854

    ANDRADE, C.G.; FIGUEIREDO, R.C.B.Q.; RIBEIRO, K.R.C.; SOUZA, L.I.O.; SARMENTO-NETO, J.F.; REBOUCAS, J.S.; SANTOS, B.S.; RIBEIRO, M.S. ; CARVALHO JUNIOR, L.B.; FONTES, A.. Photodynamic effect of zinc porphyrin on the promastigote and amastigote forms of Leishmania braziliensis. Photochemical & Photobiological Sciences, v. 17, n. 4, p. 482-490, 2018. DOI: 10.1039/c7pp00458c

    Abstract: Leishmaniasis is a neglected disease present in more than 88 countries. The currently adopted chemotherapy faces challenges related to side effects and the development of resistance. Photodynamic therapy (PDT) is emerging as a therapeutic modality for cutaneous leishmaniasis. Zn(II) meso-tetrakis(Nethylpyridinium- 2-yl)porphyrin (ZnTE-2-PyP4+, ZnP) is a cationic, water-soluble, zinc porphyrin-based photosensitizer whose photodynamic effect on Leishmania braziliensis was analyzed by evaluating the number of visibly undamaged and motile cells, cell membrane integrity, mitochondrial membrane potential, and ultrastructural damage. Treatment of parasites with ZnP and light induced damage in up to 90% of L. braziliensis promastigote cells. Propidium iodide labeling suggested the loss of plasma membrane integrity. In samples treated with ZnP and light, a hyperpolarization of the mitochondrial membrane potential was also observed. Ultrastructural evaluation of promastigotes after photodynamic treatment indicated a loss of cytoplasmic material and the presence of vacuoles. Scanning electron microscopy showed wrinkling of the plasma membrane and a reduced cell volume. Additionally, the number of amastigotes per macrophage was reduced by about 40% after photodynamic application. The treatment showed no considerable toxicity against mammalian cells. Therefore, the results indicated that PDT associated with ZnTE-2-PyP4+ represents a promising alternative to cutaneous leishmaniasis treatment.

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  • IPEN-DOC 24693

    OLIVEIRA, L.N. de; NASCIMENTO, E.O. do; SCHIMIDT, F.; ANTONIO, P.L. ; CALDAS, L.V.E. . Assessment of Ethylene Vinyl-Acetato Copolymer (EVA) samples bombarded by gamma radiation via linearity analyses. Journal of Physics: Conference Series, v. 975, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012041

    Abstract: Materials with the potential to become dosimeters are of interest in radiation physics. In this research, the materials were analyzed and compared in relation to their linearity ranges. Samples of ethylene vinyl-acetate copolymer (EVA) were irradiated with doses from 10 Gy to 10 kGy using a 60Co Gamma-Cell system 220 and evaluated with the FTIR technique. The linearity analyses were applied through two methodologies, searching for linear regions in their response. The results show that both applied analyses indicate linear regions in defined dose interval. The radiation detectors EVA can be useful for radiation dosimetry in intermediate and high doses.

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  • IPEN-DOC 24822

    WEBLER, G.D.; RODRIGUES, W.C.; SILVA, A.E.S.; SILVA, A.O.S.; FONSECA, E.J.S.; DEGENHARDT, M.F.S.; OLIVEIRA, C.L.P.; OTUBO, L. ; BARROS FILHO, D.A.. Use of micrometric latex beads to improve the porosity of hydroxyapatite obtained by chemical coprecipitation method. Applied Surface Science, v. 436, p. 141-151, 2018. DOI: 10.1016/j.apsusc.2017.11.218

    Abstract: Hydroxyapatite is one of the most important biomaterials whose application mainly extends to implants and drug delivery. This work will discuss the changes in the pore size distribution of hydroxyapatite when there are latex beads present during the synthesis. These changes were monitored using different techniques: small angle X-ray scattering, X-ray diffraction, thermal gravimetrical analysis, N2 adsorption, scanning and transmission electron microscopy. Latex beads and hydroxyapatite form a single nanocomposite with well-distinguished inorganic and organic phases. Latex bead removal in the temperature range of 300–600 ◦C did not modify the original crystalline structure of hydroxyapatite. However, the latex beads favored an increase in the adsorption capacity of mesopores at temperatures higher than their glassy transition (Tg). The main result of this research work consists on the increase of surface area and pore size distribution obtained after the removal of latex beads template. Latex beads have been used in a different approach changing the porosity of hydroxyapatite scaffolds not only introducing new routes for cell integration but also broadening the pore size distribution which can result in a more high efficiency for drug release in living cells.

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  • IPEN-DOC 24820

    RAHMAN, S.U.; MOSCA, R.C. ; REDDY, S.G.; NUNEZ, S.C.; ANDREANA, S.; MANG, T.S.; ARANY, P.R.. Learning from clinical phenotypes: low-dose biophotonics therapies in oral diseases. Oral Diseases, v. 24, n. 1-2, p. 261-276, 2018. DOI: 10.1111/odi.12796

    Abstract: This narrative review on the use of biophotonics therapies for management of oral diseases is written as a tribute to Prof. Crispian Scully. His seminal contributions to the field are highlighted by the detailed, comprehensive description of clinical presentations of oral diseases. This has enabled a more thorough, fundamental understanding of many of these pathologies by research from his group as well as inspired mechanistic investigations in many groups globally. In the same vein, a major emphasis of this narrative review is to focus on the evidence from human case reports rather than in vitro or in vivo animal studies that showcases the growing and broad impact of biophotonics therapies. The similarities and differences between two distinct forms of low-dose biophotonics treatments namely photodynamic therapy and photobiomodulation therapy are discussed. As evident in this review, a majority of these reports provide promising evidence for their clinical efficacy. However, a lack of adequate technical details, precise biological rationale, and limited outcome measures limits the current utility of these treatments. Future investigations should attempt to address these shortcomings and develop better designed, rigorous, controlled studies to fully harness the tremendous potential of low-dose biophotonics therapies.

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  • IPEN-DOC 24819

    OLIVEIRA, MARA C.L. de; CORREA, OLANDIR V. ; ETT, BARDIA; SAYEG, ISAAC J.; LIMA, NELSON B. de ; ANTUNES, RENATO A.. Influence of the tungsten content on surface properties of electroless Ni-W-P coatings. Materials Research - Ibero-American Journal of Materials, v. 21, n. 1, p. 1-13, 2018. DOI: 10.1590/1980-5373-MR-2017-0567

    Abstract: Ternary Ni-W-P films were produced by electroless deposition using baths with different tungsten concentrations. After deposition, the coated surfaces were annealed at 400°C for 1h. Surface morphology and film composition in the as-plated condition were assessed by SEM and EDS analyses, respectively. The crystalline phases after annealing were investigated by X-ray diffraction (XRD). Nanoindentation tests were performed to assess the mechanical properties of the deposited films. Surface roughness was determined by confocal laser scanning microscopy (CLSM). Friction coefficient was evaluated by reciprocating were tests in a nanotribometer. The corrosion behavior was evaluated by potentiodynamic polarization curves. The results showed that the surface morphology, crystallization behavior and corrosion resistance were affected by the tungsten content in the film. The best corrosion performance was obtained for the ternary films after annealing. Hardness, surface roughness and friction coefficient were dependent of the tungsten concentration in the film.

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  • IPEN-DOC 24818

    IZIDORO, JULIANA de C. ; MIRANDA, CAIO da S. ; GUILHEN, SABINE N. ; FUNGARO, DENISE A. ; WANG, SHAOBIN. Treatment of coal ash landfill leachate using zeolitic materials from coal combustion by-products. Advanced Materials and Technologies for Environmental Applications, v. 2, n. 1, p. 177-186, 2018.

    Abstract: Three different zeolitic materials derived from coal combustion by-products (CCBs) were used to treat local coal ash landfill leachate at the same power plant. The zeolitic materials properties were characterized in terms of mineralogical composition (XRD), chemical composition (XRF), total carbon content, morphological analysis (SEM), specific surface area (BET method), cation exchange capacity (CEC), loss of ignition, pH, conductivity and bulk density. XRD indicated that sodalite zeolite was formed in all the samples after hydrothermal activation of CCBs. One zeolitic product from baghouse fly ash (ZFB) presented the lowest SiO2/Al2O3 ratio, highest CEC and specific surface area, thus having a high capacity in removal of heavy metal pollutants. The zeolitic products were efficient to reduce arsenic concentration to a value below the legislation. All zeolitic materials also showed a significant removal of Ni, Cd, Zn and Co except of Cr at a dose of 10 g L-1. Thus, this work provides a sustainable strategy to resolution of solid waste from power plants.

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  • IPEN-DOC 24817

    ICHIKAWA, RODRIGO U. ; ROCA, ALEJANDRO G.; LOPEZ-ORTEGA, ALBERTO; ESTRADER, MARTA; PERAL, INMA; TURRILLAS, XABIER; NOGUES, JOSEP. Combining X-Ray whole powder pattern modeling, rietveld and pair distribution function analyses as a novel bulk approach to study interfaces in heteronanostructures: oxidation front in FeO/Fe3O4 core/shell nanoparticles as a case study. Small, v. 14, n. 30, p. 1800804-1 - 1800804-11, 2018. DOI: 10.1002/smll.201800804

    Abstract: Understanding the microstructure in heterostructured nanoparticles is crucial to harnessing their properties. Although microscopy is ideal for this purpose, it allows for the analysis of only a few nanoparticles. Thus, there is a need for structural methods that take the whole sample into account. Here, a novel bulk‐approach based on the combined analysis of synchrotron X‐ray powder diffraction with whole powder pattern modeling, Rietveld and pair distribution function is presented. The microstructural temporal evolution of FeO/Fe3O4 core/shell nanocubes is studied at different time intervals. The results indicate that a two‐phase approach (FeO and Fe3O4) is not sufficient to successfully fit the data and two additional interface phases (FeO and Fe3O4) are needed to obtain satisfactory fits, i.e., an onion‐type structure. The analysis shows that the Fe3O4 phases grow to some extent (≈1 nm) at the expense of the FeO core. Moreover, the FeO core progressively changes its stoichiometry to accommodate more oxygen. The temporal evolution of the parameters indicates that the structure of the FeO/Fe3O4 nanocubes is rather stable, although the exact interface structure slightly evolves with time. This approach paves the way for average studies of interfaces in different kinds of heterostructured nanoparticles, particularly in cases where spectroscopic methods have some limitations.

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  • IPEN-DOC 24815

    FERREIRA, EDUARDO G.A. ; YOKAICHIYA, FABIANO; MARUMO, JULIO T. ; VICENTE, ROBERTO ; GARCIA-MORENO, FRANCISCO; KAMM, PAUL H.; KLAUS, MANUELA; RUSSINA, MARGARITA; GUNTHER, GERRIT; JIMENEZ, CATALINA E.; FRANCO, MARGARETH K.K.D. . Influence of the irradiation in cement for the Brazilian radioactive waste repositories: characterization via X-ray diffraction, X-ray tomography and quasielastic neutron scattering. Physica B: Condensed Matter, p. 1-6, 2018. DOI: 10.1016/j.physb.2018.01.018

    Abstract: Powerful characterization techniques have allowed detailing the investigation of cementitious materials that must endure for millennia as an engineered barrier in radioactive waste repositories. Cement is used in the repository, as waste immobilization matrix, structural material and an additional barrier against the contact of the waste with the biosphere. The material properties have to comply with requirements in respect to a number of parameters including homogeneity, permeability, and leachability, as well as withstand mechanical stress, heat, chemical and microbial attack, and the effects of ionizing radiation. The present study aims to investigate the behavior of cementitious materials contributing to the understanding of the processes that occur in hydrated cement under the environmental conditions of a repository and to estimate the durability of these materials. In this study was observed the changes caused by radiation, to which the material was exposed. A reference Portland cement paste and grout samples were compared with irradiated ones by X-ray diffraction and Tomography. Original and valuable results concerning the investigation of the influence of radiation on cement samples were also obtained by quasielastic scattering. These results are not accessible by others techniques.

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  • IPEN-DOC 24812

    ZARPELON, L.M.C. ; BANCZEK, E.P. ; MARTINEZ, L.G. ; LIMA, N.B. ; COSTA, I. ; FARIA, R.N. . Effects of magnesium content on structure and electrochemical properties of La-Mg-Pr-Al-Mn-Co-Ni hydrogen storage alloys. Advances in Materials Science and Engineering, n. 9284943, p. 2-11, 2018. DOI: 10.1155/2018/9284943

    Abstract: The discharge capacity, microstructures, and corrosion resistance of some as-cast alloys represented by the formula La0.7−xMgxPr0.3Al0.3Mn0.4Co0.5Ni3.8, where x = 0.0, 0.1, 0.3, 0.5, and 0.7, were investigated by SEM/EDX, XRD, and electrochemical measurements. The partial substitution of La by Mg refined the grain structure while the total substitution changed it from equiaxed to columnar. Three phases were detected: a major phase (M), a grey phase (G), and a dark phase (D). The compositions analyzed by EDX suggested that the M phase was close to a LaNi5 phase. With the increase of the Mg content, the analyses revealed a G phase with composition close to a RMg2Ni9 (R = La,Pr) and a D phase close to a MgNi2 phase. The XRD analysis and Rietveld refinement corroborated the EDX results. The corrosion resistance of the alloys was evaluated in 6.0 mol·L−1 KOH solution, and the results showed that the substitution of La by Mg was beneficial for this alloy property. Nevertheless, Mg addition was deleterious to the discharge capacity of the electrodes.

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  • IPEN-DOC 24811

    ZAMPIVA, RUBIA Y.S.; ACAUAN, LUIZ H.; VENTURINI, JANIO; GARCIA, JOSE A.M.; SILVA, DIEGO S. da ; HAN, ZHAOHONG; KASSAB, LUCIANA R.P.; WETTER, NIKLAUS U. ; AGARWAL, ANURADHA; ALVES, ANNELISE K.; BERGMANN, CARLOS P.. Tunable green/red luminescence by infrared upconversion in biocompatible forsterite nanoparticles with high erbium doping uptake. Optical Materials, v. 76, p. 407-415, 2018. DOI: 10.1016/j.optmat.2018.01.004

    Abstract: Nanoparticles represent a promising platform for diagnostics and therapy of human diseases. For biomedical applications, these nanoparticles are usually coated with photosensitizers regularly activated in a spectral window of 530–700 nm. The emissions at 530 nm (green) and 660 nm (red) are of particular interest for imaging and photodynamic therapy, respectively. This work presents the Mg2SiO4:Er3+ system, produced by reverse strike co-precipitation, with up to 10% dopant and no secondary phase formation. These nanoparticles when excited at 985 nm show upconversion emission with peaks around 530 and 660 nm, although excitation at 808 nm leads to only a single emission peak at around 530 nm. The direct upconversion of this biomaterial without a co-dopant, and its tunability by the excitation source, renders Mg2SiO4:Er3+ nanoparticles a promising system for biomedical applications.

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  • IPEN-DOC 24808

    YAMAMURA, HIROCHI; SILVA, VICTOR H.P. da; RUIZ, PEDRO L.M.; USSUI, VALTER ; LAZAR, DOLORES R.R. ; RENNO, ANA C.M.; RIBEIRO, DANIEL A.. Physico-chemical characterization and biocompatibility of hydroxyapatite derived from fish waste. Journal of the Mechanical Behavior of Biomedical Materials, v. 80, p. 137-142, 2018. DOI: 10.1016/j.jmbbm.2018.01.035

    Abstract: The aim of this study was to synthesize hydroxyapatite (HAP) powder from fish waste. The powder was characterized through X-ray diffraction, Fourier transform infrared spectroscopy, ion exchange chromatography, scanning electron microscopy and plasma emission spectrometry. The cyto- and genotoxicity was carried out to demonstrate biocompatibility in vivo by means of rat subcutaneous tissue test. The results showed that the visible crystalline nature of typical apatite crystal structure when they were calcined at 800 °C. Infrared spectroscopy analysis showed similar composition to HAP standard with the presence of carbonate ion demonstrated by wave number values of 871 cm−1 and 1420 cm−1 for calcinations at 800 °C. The scanning electronmicrographies depicted the crystal morphology and porous nature with average pore size of ~10 µm. Plasma emission spectrometry and ion exchange chromatography confirmed the presence of Ca and P in the samples. The mean of calcium content was 36.8; Mg was 0.8, Na was 0.7 and K was 0.5. Rat subcutaneous tissue test revealed that HAP presented biocompatibility. Furthermore, the lack of cyto- and genotoxicity in blood, liver, kidney and lung were noticed after 30 days of HAP implantation. Taken together, our results demonstrated that HAP from fish waste exhibits a great potential for using as biomaterial since is represents a simple, effective, low-cost process and satisfactory degree of biocompatibility.

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  • IPEN-DOC 24805

    VALENCA, JOAO V.B.; SILVA, ANIELLE C.A.; DANTAS, NOELIO O.; CALDAS, LINDA V.E. ; DERRICO, FRANCESCO; SOUZA, SUSANA O.. Optically stimulated luminescence of the [20% Li2CO3 + x% K2CO3 + (80 - x)% B2O3] glass system. Journal of Luminescence, v. 200, p. 248-253, 2018. DOI: 10.1016/j.jlumin.2018.03.060

    Abstract: This study analyzed the optically simulated luminescence (OSL) of borate glasses containing lithium carbonate and potassium carbonate. Borate glasses present desirable characteristics for dosimetry and have been extensively analyzed in relation to thermoluminescence (TL). Five formulations containing 20% of Li2CO3 and different amounts of B2O3 and K2CO3 were produced. Their OSL signal was analyzed following exposure to beta particles. The decay pattern typical of continuous wave stimulation (CW-OSL) was observed for all compositions. Depending on the parameter chosen to normalize the dose-response curve, the sensitivity range changed. If the initial OSL intensity was chosen as reference, the composition containing 65% B2O3 and 15% K2CO3 (named L15KB) presented the most intense signal. However, if the total area below the curve was considered, the composition containing 70% B2O3 and 10% K2CO3 (named L10KB) was the most sensitive. A comparison of the OSL decay for the two quoted compositions, after pre-heating to 200 °C for 10 s prior to the OSL readout, showed a slight change in the decay pattern compared to the absence of pre-heating. The pre-heating treatments also showed the correlation between the shallow traps and the fast component of the OSL decay for L15KB. For all compositions, an increase in dose implied an increase in emitted signal, and no saturation was observed between 0.1 Gy and 7 Gy.

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  • IPEN-DOC 24804

    UMBEHAUN, PEDRO E. ; TORRES, WALMIR M. ; SOUZA, JOSE A.B. ; YAMAGUCHI, MITSUO ; SILVA, ANTONIO T. e ; MESQUITA, ROBERTO N. de ; SCURO, NIKOLAS L. ; ANDRADE, DELVONEI A. de . Thermal hydraulic analysis improvement for the IEA-R1 research reactor and fuel assembly design modification. World Journal of Nuclear Science and Technology, v. 8, n. 2, p. 54-69, 2018. DOI: 10.4236/wjnst.2018.82006

    Abstract: This paper presents the sequence of activities to improve the thermal hydraulic analysis of the IEA-R1 research reactor to operate in safe conditions after power upgrade from 2 to 5 MW and core size reduction from 30 to 24 fuel assemblies. A realistic analysis needs the knowledge of the actual operation conditions (heat flow, flow rates) beyond the geometric data and the uncertainties associated with manufacturing and measures. A dummy fuel assembly was designed and constructed to measure the actual flow rate through the core fuel assemblies and its pressure drop. First results showed that the flow distribution over the core is nearly uniform. Nevertheless, the values are below than the calculated ones and the core bypass flow rate is greater than those estimated previously. Based on this, several activities were performed to identify and reduce the bypass flow, such as reduction of the flow rate through the sample irradiators, closing some unnecessary secondary holes on the matrix plate, improvement in the primary flow rate system and better fit of the core components on the matrix plate. A sub-aquatic visual system was used as an important tool to detect some bypass flow path. After these modifications, the fuel assemblies flow rate increased about 13%. Additional tests using the dummy fuel assembly were carried out to measure the internal flow distribution among the rectangular channels. The results showed that the flow rate through the outer channels is 10% - 15% lower than the internal ones. The flow rate in the channel formed between two adjacent fuel assemblies is an estimated parameter and it is difficult to measure because this is an open channel. A new thermal hydraulic analysis of the outermost plates of the fuel assemblies takes into account all this information. Then, a fuel design modification was proposed with the reduction of 50% in the uranium quantity in the outermost fuel plates. In order to avoid the oxidation of the outermost plates by high temperature, low flow rate, a reduction of 50% in the uranium density in the same ones was shown to be adequate to solve the problem.

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  • IPEN-DOC 24803

    ULRICH, J.C. ; GUILHEN, S.N.; COTRIM, M.E.B. ; PIRES, M.A.F. . Method development and validation for simultaneous determination of IEA-R1 reactor’s pool water uranium and silicon content by ICP OES. Journal of Physics: Conference Series, v. 975, n. 012012, p. 1-5, 2018. DOI: 10.1088/1742-6596/975/1/012012

    Abstract: IPEN’s research reactor, IEA-R1, an open pool type research reactor moderated and cooled by light water. High quality water is a key factor in preventing the corrosion of the spent fuel stored in the pool. Leaching of radionuclides from the corroded fuel cladding may be prevented by an efficient water treatment and purification system. However, as a safety management policy, IPEN has adopted a water chemistry control which periodically monitors the levels of uranium (U) and silicon (Si) in the pool’s reactor, since IEA-R1 employs U3Si2-Al dispersion fuel. An analytical method was developed and validated for the determination of uranium and silicon by ICP OES. This work describes the validation process, in a context of quality assurance, including the parameters selectivity, linearity, quantification limit, precision and recovery.

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  • IPEN-DOC 24802

    TANGO, RUBENS N.; ARATA, ANELYSE ; BORGES, ALEXANDRE L.S.; COSTA, ANNA K.F.; PEREIRA, LUCIANO J.; KAMINAGAKURA, ESTELA. The role of new removable complete dentures in stimulated salivary flow and taste perception. Journal of Prosthodontics - Implant Esthetic and Reconstructive Dentistry, v. 27, n. 4, p. 335-339, 2018. DOI: 10.1111/jopr.12507

    Abstract: Purpose: To evaluate the effect of replacement of inadequate complete dentures on salivary flow and taste perception in geriatric patients. Materials and Methods: Thirty-three patients, 13 males and 20 females, with amean age of 64.4 years were submitted to stimulated and unstimulated salivary flow rate and salivary pH measurements, and sense of taste evaluation. Tests were performed 3 months before complete denture substitution and 3 weeks after denture insertion. Results: The mean for unstimulated saliva (USS) was 2.1 ml before and 2.7 ml after replacement (p = 0.003). The mean volume of stimulated saliva was 6.3 ml before and 8.2 ml after replacement (p = 0.004). The pH mean of USS was 7.8 ± 0.44 before and 8.02 ± 0.41 after replacement (p = 0.005). No statistically significant difference was determined in the sense of taste before and 3 weeks after complete denture replacement. Conclusions: The replacement of inadequate complete dentures increases saliva flow; however, it does not improve taste perception.

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  • IPEN-DOC 24800

    SOUZA, F.M.; NANDENHA, J.; BATISTA, B.L.; OLIVEIRA, V.H.A.; PINHEIRO, V.S.; PARREIRA, L.S.; NETO, A.O. ; SANTOS, M.C.. PdxNby electrocatalysts for DEFC in alkaline medium: stability, selectivity and mechanism for EOR. International Journal of Hydrogen Energy, v. 43, n. 9, p. 4505-4516, 2018. DOI: 10.1016/j.ijhydene.2018.01.058

    Abstract: PdxNby/C binary electrocatalysts supported on Vulcan carbon XC72 were prepared by the sol-gel method. The materials are characterized by transmission electron microscopy, X-ray diffraction analysis, inductively coupled plasma–mass spectrometry and contact angle measurements. The electrocatalytic activity for ethanol electrooxidation reaction was studied by cyclic voltammetry, chronoamperometry, Tafel slope and accelerated durability testing. The direct ethanol performance and the products after the experiments were studied by Fourier transform infrared spectroscopy. Pd1Nb1/C (50:50 wt%) shows superior activity for ethanol oxidation compared to the other electrocatalysts prepared in this work. All electrocatalysts containing Nb show the highest current exchange density. The Tafel slope results suggest that the Nb modified the Pd-electrocatalyst to obtain a reaction path with high selectivity with only a single determining step with low production of the intermediates for the ethanol oxidation reaction. The best performance is obtained using Pd1Nb1/C 18.11 mW cm−2. The Pd1Nb1/C electrocatalyst displays the highest production of CO2 and the lowest production of acetaldehyde. Pd1Nb1/C shows the highest peak current density during 1000 cycles of the experiment and the lowest mass loss of Pd after the cycling test. We find that the Nb modifies the Pd electrocatalysts from the bifunctional mechanism and reduces the loss of Pd during the accelerated durability test.

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  • IPEN-DOC 24798

    SILVEIRA, LUCAS M. da; PEREIRA, MARCO A.M.; NEVES, LUCIO P. ; PERINI, ANA P. ; BELINATO, WALMIR; CALDAS, LINDA V.E. ; SANTOS, WILLIAM S.. Exposure to 137Cs deposited in soil – A Monte Carlo study. Journal of Physics: Conference Series, v. 975, n. 012050, p. 1-5, 2018. DOI: 10.1088/1742-6596/975/1/012050

    Abstract: In the event of an environmental contamination with radioactive materials, one of the most dangerous materials is 137Cs. In order to evaluate the radiation doses involved in an environmental contamination of soil, with 137Cs, we carried out a computational dosimetric study. We determined the radiation conversion coefficients (CC) for effective (E) and equivalent (H T) doses, using a male and a female anthropomorphic phantoms. These phantoms were coupled with the MCNPX (2.7.0) Monte Carlo simulation software, for three different types of soil. The highest CC[H T] values were for the gonads and skin (male) and bone marrow and skin (female). We found no difference for the different types of soil.

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  • IPEN-DOC 24797

    SILVA, P.S.M.; ESPOSITO, V.; MARANI, D.; FLORIO, D.Z. de; MACHADO, I.F.; FONSECA, F.C. . Thermochemical stability of zirconia-titanium nitride as mixed ionic-electronic composites. Ceramics International, v. 44, n. 7, p. 8440-8446, 2018. DOI: 10.1016/j.ceramint.2018.02.039

    Abstract: Dense zirconia (8% molar yttria-stabilized ZrO2)-titanium nitride (TiN) composites are fabricated to obtain mixed ionic-electronic conducting ceramic systems with high degree of electronic and thermal conductivity. The composites are consolidated by spark plasma sintering (SPS), starting from pure powders of the pristine phases mixed in different ratios (TiN = 25, 50, 75 wt%). A careful optimization of the SPS conditions allows producing highly dense samples with no reaction between the phases or degradation by oxidation, thus maintaining the chemical integrity of the two phases. For all the composites, high electrical conductivity is attained. Samples exhibit metallic behavior, showing an unexpected percolation of TiN in the YSZ matrix for volume fraction ≤ 25 wt% (27 vol%). Chemical degradation and electrical properties of the compounds were monitored under oxidative (air) and inert (Ar) atmosphere at high temperatures. The oxidation kinetics of the nitride phase was inhibited by the microstructure of the composite. The electrical properties of such composites were explored at high temperature to evaluate its application in electrochemical devices. As results, it is shown that electrical transport properties of the composite can be tuned by both the relative volume fraction of phases and controlled oxidative treatments. Adjusting such parameters different electric behaviors were observed ranging from predominant electronic conductors, to temperature-independent resistivity, and semiconducting.

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  • IPEN-DOC 24796

    SILVA, R.A.; LEAL NETO, R.M. ; LEIVA, D.R.; ISHIKAWA, T.T.; KIMINAMI, C.S.; JORGE JUNIOR, A.M.; BOTTA, W.J.. Room temperature hydrogen absorption by Mg and Mg-TiFe nanocomposites processed by high-energy ball milling. International Journal of Hydrogen Energy, v. 43, n. 27, p. 12251-12259, 2018. DOI: 10.1016/j.ijhydene.2018.04.174

    Abstract: Mg - 40 wt % TiFe nanocomposite was prepared by high-energy ball milling, HEBM, aiming improved hydrogen absorption at room temperature (RT). Four processing routes were chosen to separately investigate the effects of TiFe addition, HEBM processing and dispersion of TiFe particles, being: Route 1 – mechanical mixture of Mg and TiFe powders; Route 2 – HEBM of Mg + TiFe at 400 rpm for 12 h; Route 3 – HEBM of pure Mg at 400 rpm for 12 h to be used as reference; and Route 4 – HEBM of Mg + TiFe at 600 rpm for 36 h. In this case, TiFe was previously milled with ethanol to improve its refinement level. It is shown that the synergetic effects of TiFe addition, HEBM processing and thermal activation – involving the creation of MgTiFe interfaces, the refinement and distribution of TiFe and also the presence of free Fe – lead to good hydrogenation kinetics at RT in MgTiFe nanocomposite. It is also shown for the first time that the milled pure Mg can absorb hydrogen at RT.

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  • IPEN-DOC 24794

    SILVA, N.F. ; SILVA, T.F.; CASTRO, M.C. ; LUZ, H.N. da; CALDAS, L.V.E. . Construction of the TH-GEM detector components for metrology of low energy ionizing radiation. Journal of Physics: Conference Series, v. 975, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012043

    Abstract: The Gas Electron Multiplier (GEM) detector was originally proposed as a position sensitive detector to determine trajectories of particles prevenient from high-energy collisions. In order to study the potential of TH-GEM type detectors in dosimetric applications for low energy X-rays, specifically for the mammography standard qualities, it was proposed to construct a prototype with characteristics suitable for such use. In this work the general, structural and material parameters applicable to the necessary conditions were defined, establishing the process of construction of the components of a prototype.

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  • IPEN-DOC 24792

    SENNA, ANDRE M. de; VIEIRA, MARTHA M.F. ; MACHADO-DE-SENA, ROSA M.; BERTOLIN, APARECIDO O.; NUNEZ, SILVIA C.; RIBEIRO, MARTHA S. . Photodynamic inactivation of Candida ssp. on denture stomatitis. A clinical trial involving palatal mucosa and prosthesis disinfection. Photodiagnosis and Photodynamic Therapy, v. 22, p. 212-216, 2018. DOI: 10.1016/j.pdpdt.2018.04.008

    Abstract: Denture stomatitis (DS) is the most common oral fungal infection in denture wearers. Photodynamic inactivation (PDI) has been showing to be an effective technique in vivo against fungi, including fungal infections in the oral cavity. The disinfection of both oral mucosa and denture may represent a real advantage in terms of fungus control. This clinical study was designed to explore methylene blue (MB)-mediated PDI on oral mucosa and prosthesis of patients with DS. Subjects with DS were divided into two groups. One group received treatment based on the use of oral miconazole gel 2% (MIC). The other group received treatment by PDI using MB at 450 μg/mL and a diode laser (λ = 660 nm) with 100 mW and fluence of 28 J/cm2. Clinical outcome was evaluated regarding the degree of oral mucosa erythema and microbiological reduction of Candida spp. located in both palatal mucosa and prosthesis. Our results showed that PDI was significantly more effective than MIC in ameliorating inflammation after 15 days. Following 30 days, no statistically significant differences were observed between groups. Regarding the fungal burden, although the MIC group has presented more pronounced inactivation than PDI for both mucosa and prosthesis, no statistically significant differences were detected between them. This clinical study suggests that PDI can reduce fungal load and decrease the inflammation degree in patients with Candida-associated denture stomatitis.

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  • IPEN-DOC 24790

    SCURO, N.L.; ANGELO, E.; ANGELO, G. ; ANDRADE, D.A. . A CFD analysis of the flow dynamics of a directly-operated safety relief valve. Nuclear Engineering and Design, v. 328, p. 321-332, 2018. DOI: 10.1016/j.nucengdes.2018.01.024

    Abstract: A three-dimensional numerical study on steady state was designed for a safety relief valve using several openings and inlet pressures. The ANSYS-CFX (R) commercial code was used as a CFD tool to obtain several properties using dry saturated steam revised by IAPWS-IF97. Mass flow and discharge coefficient calculated from simulations are compared to the ASME 2011a Section 1 standard. The model presented constant behavior for opening lifts smaller than 12mm and is very reasonable when compared to the standard (ASME). In addition, the conventional procedure to design normal disc force assumes that all the fluid mechanical energy was converted into work; however, the CFD simulations showed that average normal disc force is about 19% lower than theoretical ASME force, which could prevent the valve oversizing. A numerical validation was conducted for a transonic air flow through a converging-diverging diffuser geometry to verify the solver's ability to capture the position and intensity of a shockwave: the results showed good agreement with the benchmark experiments.

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  • IPEN-DOC 24789

    SAVOINE, MARCIA M. ; MENEZES, MARIO O. de ; ANDRADE, DELVONEI A. de . Proposal of a methodology for the assessment of security levels of IoT wireless sensor networks in nuclear environments. World Journal of Nuclear Science and Technology, v. 8, n. 2, p. 78-85, 2018. DOI: 10.4236/wjnst.2018.82008

    Abstract: The use of Wireless Sensor Networks (WSN) associated with the reality of an Internet of Things (IoT) scenario in nuclear environments is a growing security concern. In this context, standards are intensified to preserve the physical integrity of these facilities considered to be highly critical due to the size of the impacts of safety accidents. This paper presents a proposal to build a methodology to evaluate the security levels of WSNs with IoT devices when used in nuclear areas. The proposal is initially based on related work to establish a more concrete initial framework and is structured in consistent steps from previous scientific studies.

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  • IPEN-DOC 24787

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . EPR dosimetry of yttria micro rods. Journal of Alloys and Compounds, v. 742, p. 263-270, 2018. DOI: 10.1016/j.jallcom.2018.01.315

    Abstract: The use of rare earths (RE) as dopant of materials has led the development of advanced materials for many applications such as optical tracers, special alloys, semiconductors, as well as radiation dosimeters. The development of new dosimetric materials based on REs is a great challenge in innovation of materials. Yttria (Y2O3) presents luminescent proprieties and is a promising material for radiation dosimetry. The present paper aims to evaluate paramagnetic defects of Y2O3 rods obtained via bio-prototyping by using Electron Paramagnetic Resonance (EPR) technique at room temperature. Ceramic rods were irradiated with gamma doses from 0.001 to 150 kGy and evaluated by EPR at room temperature with X-band EPR. According to EPR results, as sintered samples exhibited an EPR signal with principal g tensor of 2.020 and maximum line width around 2.3 mT, which is ascribed to interstitial oxygen ion. Dose response behaviour exhibited two distinct dose ranges, one is from 1 to 100Gy and the second is from 0.1 to 70 kGy. Thermal annealing approaches reveal that defect centres of yttria decay significantly at high temperature. These innovative results make Y2O3 a promising material for radiation dosimetry.

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  • IPEN-DOC 24786

    SANTOS, ROSA C.L.; LIMA, ALVARO S.; CAVALCANTI, ELIANE B.; MELO, CLAUDIA M. de; MARQUES, MARIA N. . Aplicação de índices para avaliação da qualidade da água da Bacia Costeira do Sapucaia em Sergipe / Application of indexes to assess the water quality of coastal basin of the Sapucaia in Sergipe. Engenharia Sanitaria e Ambiental, v. 23, n. 1, p. 33-46, 2018. DOI: 10.1590/S1413-41522017159832

    Abstract: A redução da disponibilidade qualiquantitativa da água no mundo está diretamente relacionada às formas de uso e ocupação do solo, aos processos produtivos da agricultura e da pecuária, ao processo de urbanização e à geração de efluentes domésticos e industriais. Por isso, é importante a realização de diagnósticos de bacias hidrográficas, sobre o uso e a ocupação de seu solo e sobre a qualidade da água como ferramenta para a gestão hídrica. Este estudo teve como objetivo caracterizar e monitorar a qualidade da água da Bacia Costeira do Sapucaia, Sergipe. As coletas foram realizadas em oito pontos, com periodicidade trimestral, de agosto de 2014 a setembro de 2015. Na avaliação da qualidade da água foram utilizados: o Índice de Qualidade da Água (IQA) e o Índice de Estado Trófico (IET). As análises das amostras foram realizadas de acordo com os procedimentos estabelecidos no Standard Methods, sendo analisados os seguintes parâmetros: coliformes totais e termotolerantes, turbidez, pH, oxigênio dissolvido, sólidos totais, fósforo total, nitrogênio total, temperatura, condutividade, demanda bioquímica de oxigênio e clorofila. Os resultados do IQA classificam os corpos d’água em aceitável (2,5%), bom (92,5%) e ótimo (5,0%). Os resultados do IET classificaram as amostras como: ultraoligotrófico (67,5%), oligotrófico (20,0%), mesotrófico (2,5%), eutrófico (7,5%) e supereutrófico (2,5%). Os resultados obtidos permitem afirmar que os rios Aningas, Sapucaia e a Lagoa Redonda apresentam baixo grau de degradação, com menor conservação do ponto amostral localizado no Rio Sapucaia, dentro da Reserva Santa Isabel, por ser uma área bastante visitada nos finais de semana e feriados.

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  • IPEN-DOC 24785

    SALLES, FERNANDA J.; SATO, ANA P.S.; LUZ, MACIEL S.; FAVARO, DEBORAH I.T. ; FERREIRA, FRANCISCO J.; PAGANINI, WANDERLEY da S.; OLYMPIO, KELLY P.K.. The environmental impact of informal and home productive arrangement in the jewelry and fashion jewelry chain on sanitary sewer system. Environmental Science and Pollution Research, v. 25, n. 11, p. 10701-10713, 2018. DOI: 10.1007/s11356-018-1357-z

    Abstract: The outsourcing informal home practices adopted in jewelry and fashion jewelry chain can cause toxic substance elimination in the effluents and raise a concern for its environmental impact. This study evaluates if this informal work alters the concentration of potentially toxic elements (PTEs: As, Cd, Cr total and Cr-VI, Cu, Hg, Ni, Pb, Sn, and Zn) in the sewage network. The sanitary sewage samples (n = 540) were collected in 15 manholes during two campaigns in three different areas of Limeira-SP, Brazil (industrial area, with informal work and without known industrial/informal activity). The sewage sludge (n = 12), raw (n = 12), and treated sewage (n = 12) were collected in two wastewater treatment plants (WWT: AS and TATU) operating with different treatment process. The PTE determination was performed by ICP-OES, direct mercury analysis, and UV-Vis spectroscopy. Cr-VI, Cu, Ni, and Zn were the only elements above the quantification limit. Four samples exceeded Cu or Zn values permitted to be discharged into sewage system; however, the concentration average was lower than that established by Brazilian legislation. A difference was found between values above and below the 75th percentile for campaign and total organic carbon values (p < 0.015). The AS-treated sewage presented low concentrations of Cu (p < 0.05), Zn (p = 0.02), and Ni (p = 0.01) compared to treated sewage from TATU. In the sludge samples, the Cu means exceeded the limits of the Brazilian legislation (1500 mg kg(-1)) and the Zn results were very close to the limits (2800 mg kg(-1)). The heterogeneity of the results can indicate the sporadic nature of the PTE's sanitary disposal. PTEs used in jewelry and fashion jewelry chain may precipitate on the sludge, where presented high concentrations of Cu and Zn which require controlled destination.

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  • IPEN-DOC 24784

    SABUNDJIAN, GAIANE ; CONTI, THADEU das N. ; CABRAL, EDUARDO L.L. . Hierarchical expansion method in the solution of the Navier-Stokes Equations for incompressible fluids in laminar two-dimensional flow. Energy and Power Engineering, v. 10, n. 1, p. 1-9, 2018. DOI: 10.4236/epe.2018.101001

    Abstract: Among the several methods used to solve the Navier-Stokes equations Hierarchical Expansion Method has demonstrated satisfactory results. This work aimed to apply the expansion of the variables in hierarchical functions for the solution of the Navier-Stokes equations for incompressible fluids in two dimensions in laminar flow. This method is based on the finite element method. The expansion functions in this study were based on Legendre polynomials, adjusted in the rectangular elements in such a way that corner, side and area functions were defined. The order of the expansion functions associated with the sides and with the area of the elements is adjusted to the necessary or desired degree. This method is denominated by Hierarchical Expansion Method. In order to validate the proposed numeric method three well-known problems of the literature in two dimensions were analyzed; however, for this paper only one problem was presented. The results demonstrated that method was able to provide precise results. From the results obtained in this paper it is possible to conclude that the hierarchical expansion method can be effective for the solution of fluid dynamic problems that involve incompressible fluids.

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  • IPEN-DOC 24783

    ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A. . Highly pure silica nanoparticles with high adsorption capacity obtained from sugarcane waste ash. ACS Omega, v. 3, n. 3, p. 2618-2627, 2018. DOI: 10.1021/acsomega.8b00092

    Abstract: Silica nanoparticles (SiO2NPs) from renewable sources can be used in very different materials, such as paints, membranes for fuel cells, Li-ion batteries, adsorbents, catalysts, and so on. Brazil is the world’s largest producer of sugarcane and generates huge amounts of sugarcane waste ash (SWA), which is a Si-rich source. This study investigates a method to produce highly pure SiO2NPs from SWA. The SiO2NPs were characterized by inductively coupled plasma optical emission spectroscopy, scanning and transmission electron microscopy (TEM), X-ray diffraction analyses, specific surface area and pore distribution, UV and Fourier transform infrared spectroscopy, and thermogravimetric analyses and applied as an adsorbent material in the removal of acid orange 8 (AO8) dye from aqueous solution. The SiO2 content was 88.68 and 99.08 wt % for SWA and SiO2NPs, respectively. TEM images of SWA and SiO2NPs exhibit drastic alterations of the material size ranging from several micrometers to less than 20 nm. The SiO2NPs showed a specific surface area of 131 m2 g–1 and adsorption capacity of around 230 mg g–1 for acid orange 8 dye. Furthermore, the recycling of the SiO2NPs adsorbent after AO8 adsorption was very satisfactory, with reuse for up to five cycles being possible. The results indicate that it was possible to obtain highly pure silica in a nanosize from the waste material and produce an adsorbent with high adsorption capacity and the possibility of reuse.

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  • IPEN-DOC 24782

    RONQUIM, FLAVIA M.; COTRIM, MARYCEL E.B. ; GUILHEN, SABINE N. ; BERNARDO, ANDRE; SECKLER, MARCELO M.. Improved barium removal and supersaturation depletion in wastewater by precipitation with excess sulfate. Journal of Water Process Engineering, v. 23, p. 265-276, 2018. DOI: 10.1016/j.jwpe.2018.04.007

    Abstract: Barium ions found in wastewaters cause incrustation on membrane separation equipment used in desalination systems. In this study barium removal by precipitation is addressed, considering excess sulfate addition as a means of reducing barium concentration in solution and depleting BaSO4 supersaturation. Precipitation is conducted with synthetic wastewater in semicontinuous mode. For low excess sulfate, an induction time of a few hours is observed. As the excess sulfate is increased and/or as barium sulfate seeds are added, precipitation proceeds within a few minutes. Besides, the excess sulfate improves barium ion removal due to the common-ion effect. Residual supersaturation ratios were found to lie within the range of 1.1–3. These values were associated with a fourth order dependency of the molecular growth rate with the supersaturation ratio. Calcium carbonate and calcium sulfate dihydrate were found to be ineffective heterogeneous seeds to barium sulfate precipitation. Calcium ions were found to inhibit BaSO4 precipitation, blocking the process at a high residual supersaturation ratio of 4–5. For a sufficiently large initial supersaturation, the solution approaches equilibrium after 180 min.

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  • IPEN-DOC 24781

    RIBEIRO, MARTHA S. ; MELO, LUCIANA S.A. de; FAROOQ, SAJID; BAPTISTA, ALESSANDRA ; KATO, ILKA T.; NUNEZ, SILVIA C.; ARAUJO, RENATO E. de. Photodynamic inactivation assisted by localized surface plasmon resonance of silver nanoparticles: in vitro evaluation on Escherichia coli and Streptococcus mutans. Photodiagnosis and Photodynamic Therapy, v. 22, p. 191-196, 2018. DOI: 10.1016/j.pdpdt.2018.04.007

    Abstract: Localized surface plasmon resonance (LSPR) of gold nanoparticles has been reported to increase the antimicrobial effect of the photodynamic therapy. Although silver nanoparticles (AgNPs) are an efficient growth inhibitor of microorganisms, no studies exploring LSPR of AgNPs to enhance the photodynamic inactivation (PDI) have been related. In this work, we described the LSPR phenomenon of AgNP sand investigated its interaction with riboflavin, a natural photosensitizer. We evaluated the use of AgNPs coated with pectin (p-AgNP) in riboflavin (Rb)-mediated PDI of Escherichia colt (Gram- bacteria) and Streptococcus mutans (Gram + bacteria) using a blue light-emitting diode (lambda = 455 +/- 20 nm) of optical power 200 mW. Irradiance was 90 mW/cm(2) and radiant exposure varied according to the time exposure. Uptake of Rb and p-AgNP by the cells was evaluated by measuring the supernatant absorption spectra of the samples. We observed that LSPR of p-AgNPs was able to enhance the riboflavin photodynamic action on S. mutans but not on E. colt, probably due to the lower uptake of Rb by E. colt. Taken together, our results provide insights to explore the use of the LPRS promoted by silver nanostructures to optimize antimicrobial PDI protocols.

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  • IPEN-DOC 24778

    PORFIRIO, T.C. ; MUCCILLO, E.N.S. . Thermal and electrical properties of CaCu3Ti4O12 synthesized by soft chemistry route. Journal of Thermal Analysis and Calorimetry, v. 133, n. 2, p. 851–857, 2018. DOI: 10.1007/s10973-018-7184-0

    Abstract: Calcium copper titanate powders were synthesized by a soft chemistry route, aiming to establish a cost-effective solution method to obtain sintered ceramics with giant electric permittivity (ε′) and low dissipation factor (tanδ). Powders and sintered pellets were characterized by several techniques. The thermal decomposition behavior of the porous foam evidences that a hydroxycitrate was formed below 200 °C. Single cubic perovskite-type phase was obtained after calcination of the precursor powder at 700 °C for 5 h. Negligible mass loss occurs above 400 °C. During heating the precursor material, CuO is the first crystallized phase. A giant ε′ and low tanδ are obtained after sintering. The extension of the thermal window of ε′ is wider than those of powders prepared by other methods.

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  • IPEN-DOC 24777

    PEREIRA, DAISA L. ; FREITAS, ANDERSON Z. ; BACHMANN, LUCIANO; BENETTI, CAROLINA; ZEZELL, DENISE M. ; ANA, PATRICIA A.. Variation on molecular structure, crystallinity, and optical properties of dentin due to Nd:YAG laser and fluoride aimed at tooth erosion prevention. International Journal of Molecular Sciences, v. 19, n. 2, 2018. DOI: 10.3390/ijms19020433

    Abstract: This in vitro study evaluated the compositional, crystalline, and morphological effects promoted by Nd:YAG laser on root dentin, and verified the effects of laser and topical acidulated phosphate fluoride application (APF-gel) on dentin erosion. 180 bovine dentin slabs were randomized into 4 groups (n = 45): G1–untreated, G2–APF-gel (1.23% F−, 4 min), G3–Nd:YAG (1064 nm, 84.9 J/cm2, 10 Hz), and G4–APF-gel application followed by Nd:YAG laser irradiation. The compositional, crystalline, and morphological effects promoted by treatments were investigated on five samples of each experimental group. The other samples were submitted to a 5-day, 10-day, or 15-day erosive and abrasive demineralization and remineralization cycling in order to create erosion lesions. The area and depth of lesions, as well as the optical attenuation coefficient, were assessed, and all data were statistically analysed (p < 0.05). Nd:YAG laser promoted the reduction of carbonate, the formation of tetracalcium phosphate, as well as the melting and recrystallization of the dentin surface. Laser significantly decreased the area and depth of erosion lesions and altered the optical attenuation coefficient when compared to untreated and APF-gel groups, but the association of APF-gel and laser did not promote an additional effect. Nd:YAG laser irradiation can be a promissory treatment to prevent dentin erosion and the abrasion process.

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  • IPEN-DOC 24776

    PEREIRA, LUIZ A.T. ; ROSSI, JESUALDO L. . The recycling through melting Zircaloy machining chips, preliminary results. Brazilian Journal of Radiation Sciences, v. 6, n. 2, p. 01-11, 2018. DOI: 10.15392/bjrs.v6i2.425

    Abstract: PWR (Pressurized Water Reactor) reactors employ as nuclear fuel UO2 pellets packed in zirconium alloy tubes, called cladding. In the manufacture of the tubes, machining chips are generated which can not be discarded, since the recycling of this material is strategic in terms of nuclear technology, legislation, economics and the environment. These nuclear alloys are very expensive and are not produced in Brazil and are imported for the manufacture of nuclear fuel. In this work, we will discuss methods not yet studied to recycle Zircaloy chips using electron beam furnaces in order to obtain ingots. In addition, it is intended to carry out the melting of new Zircaloy alloys, from the fusion of zirconium sponge produced in IPEN and imported and Zircaloy bars. The mechanical properties and the present phases of the material should be determined, as well as, the characterization of the microstructures by optical microscopy. This work, therefore, aims at the creation of a new line of research where methods will be approached to recycle the chips and to reduce in 30 times by means of fusion the enormous volume of material stored in the form of machining chips, being able to do others components for nuclear or chemical industry use, as well as conducting basic development research.

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  • IPEN-DOC 24775

    PEREIRA, JULIAN M. de S. ; CIOTTI, LIGIA; VAZ, JORGE M. ; SPINACE, ESTEVAM V. . Preparation of Au/TiO2 catalyst by a liquid-phase reduction method for preferential oxidation of carbon monoxide in a hydrogen rich-stream (CO-PROX reaction). Materials Research - Ibero-American Journal of Materials, v. 21, n. 2, 2018. DOI: 10.1590/1980-5373-MR-2017-0756

    Abstract: Au nanoparticles supported on TiO2 were prepared by a liquid-phase reduction method using HAuC1(4) 3H(2)O as the Au precursor, TiO2 as the support, a solution of ethylene glycol/water as solvent and reducing agent and sodium citrate as reducing agent and stabilizer. The Au/TiO2 catalysts were prepared usmg different routes and characterized by Energy-dispersive X-ray spectroscopy, X-ray diffraction and Transmission Electron Microscopy and tested for preferential oxidation of carbon monoxide in hydrogen-rich stream (CO-PROX reaction). The way that the Au precursor, the TiO2 support and the sodium citrate is added to the ethylene glycol/water solution strongly influences the Au nanoparticle sizes and the catalytic activity of the obtained materials.

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  • IPEN-DOC 24774

    PEREIRA, MARCO A.S. ; PUGLIESI, REYNALDO . Penetration of the consolidant Paraloid (R) B-72 in Macuxi indigenous ceramic vessels investigated by neutron tomography. Nuclear Instruments & Methods in Physics Research, A - Accelerators Spectrometers Detectors and Associated Equipment, v. 889, p. 118-121, 2018. DOI: 10.1016/j.nima.2018.02.034

    Abstract: The neutron tomography technique was applied in studying the penetration of the consolidant Paraloid (R) B-72 in contemporary indigenous ceramic vessels. The study was carried out for two distinct and controlled air humidity conditions, 40% and 90%, in which the vessels were exposed, before the consolidant application. The obtained images have proved that the penetration of Paraloid (R) B-72 in the ceramic does not depend on the humidity condition in which it was applied, moreover allowed a macro-visualization of the consolidant penetration in the ceramic vessel. As the vessels used in the present work were manufactured by an indigenous artisan, Macuxi, according to the same procedures and raw materials used by the ancient artisans, the results obtained can be used as a guide to assist experts, both in the study of archeological objects of Macuxi origin, as well as other objects that had been made by other tribes that lived in the same Amazon region, in Brazil.

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  • IPEN-DOC 24773

    PEREIRA, MARIA da C.C. ; MADI FILHO, TUFIC ; BERRETTA, JOSE R. ; MESQUITA, CARLOS H. de . Characteristics of the CsI:Tl scintillator crystal for X-Ray imaging applications. Materials Sciences and Applications, v. 9, n. 2, p. 268-280, 2018. DOI: 10.4236/msa.2018.92018

    Abstract: Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10−3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.

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  • IPEN-DOC 24772

    PACHECO, RAFAEL R. ; ANDRADE, DELVONEI A. de . Technological perspectives for propulsion on nuclear attack submarines. World Journal of Nuclear Science and Technology, v. 8, n. 1, p. 1-10, 2018. DOI: 10.4236/wjnst.2018.81001

    Abstract: This work aims to present the historical context in which the current understanding of the phenomenon of the direct contact condensation started to call the scientific society attention. The development of nuclear power plants Light Water Reactors demanded a safe way to collect and treat the water used to cool the reactor. Some characteristics of this water in a high energetic thermodynamic state made it unsuitable to be directly discharged in the atmosphere. Small room relieves tanks were developed to contain this discharge. These tanks were partially fulfilled with water, and the vapor injection created a vapor plume. In the interface of liquid and vapor, the thermal exchange would be increased by the characteristic turbulence of this region.

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  • IPEN-DOC 24771

    OTTONI, C.A.; RAMOS, C.E.D.; SOUZA, R.F.B. de; SILVA, S.G. da ; SPINACE, E.V. ; NETO, A.O. . Glycerol and ethanol oxidation in alkaline medium using PtCu/C electrocatalysts. International Journal of Electrochemical Science, v. 13, n. 2, p. 1893-1904, 2018. DOI: 10.20964/2018.02.58

    Abstract: The performance of platinum-copper electrocatalysts synthesized in different ratios (100:0, 90:10, 70:30, 50:50, and 0:100), using a borohydride reduction method for electrochemical oxidation of different fuels, was evaluated in an alkaline direct alcohol fuel cell. X-ray diffraction of Pt/C and PtCu/C showed a face-centered cubic structure (fcc) of the platinum and its alloys. Transmission electron microscopy analysis allowed us to see a good dispersion of metallic particles with some regions with clusters of nanoparticles, for all the synthesised materials in the presence of copper. Cyclic voltammetry and chronoamperometry tests demonstrated that the PtCu/C (50:50) and PtCu/C (70:30) electrocatalysts exhibited the highest activity and stability for the glycerol and ethanol oxidation, respectively. The tests made in fuel cells, directly fed with glycerol and ethanol, presented the PtCu/C (90:10) electrocatalyst as the most effective on the oxidation reaction of the fuels when compared with Pt/C and Cu/C.

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  • IPEN-DOC 24770

    ORTIZ, NILCE ; SILVA, ANDRE; LIMA, GISELLE N.S. ; HYPPOLITO, FERNANDA P. . Using solar-TiO2 and biocarbon to decompose and adsorb amoxicillin from polluted waters. International Journal of Chemistry, v. 10, n. 1, p. 131-136, 2018. DOI: 10.5539/ijc.v10n1p131

    Abstract: Surface water discharge of domestic sewage poses a treat mostly due to antibiotics content as amoxicillin. Its environmental presence provides the bacterial resistance enhancement and disturbance in aquatic life. The biocarbon is an organic carbon compound obtained by biomass pyrolisis at 300oC to 750oC under low oxygen environment. It is an effective adsorbent derived from agricultural and industrial solid biomass also frequently used to remove various pollutants, including dyes, pesticides, organic compounds and heavy metals from aqueous solutions. The importance of this natural material rises as low cost abundant and renewable alternative to activated carbon used on wastewater treatment application. Several technologies are employed to modify crude precursors on biocarbon preparation including chemical, physical and biological treatments with the addition of functional groups. The raw biomass material also provides some radicals and humic acids with promising water adsorbent results. The integrated process of the efficient Solar-TiO2photodecomposition followed by biocarbon adsorption resulted on 94% of amoxicillin removal percentage and avoids the toxic treatment sludge production.

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  • IPEN-DOC 24769

    ORTEGA, ANDRESSA dos S.B.; MARANHO, LUCIANE A.; NOBRE, CAIO R.; MORENO, BEATRIZ B.; GUIMARAES, RAFAEL S.; LEBRE, DANIEL T. ; ABESSA, DENIS M. de S.; RIBEIRO, DANIEL A.; PEREIRA, CAMILO D.S.. Detoxification, oxidative stress, and cytogenotoxicity of crack cocaine in the brown mussel Perna perna. Environmental Science and Pollution Research, p. 1-10, 2018. DOI: 10.1007/s11356-018-1600-7

    Abstract: The presence of cocaine and its metabolites and by-products has been identified in different aquatic matrices, making crack cocaine the target of recent studies. The aim of this study was to evaluate the sublethal effects of crack on the brown mussel Perna perna. Mussels were exposed to three concentrations of crack cocaine (0.5, 5.0, and 50.0 μg L−1) for 168 h. Gills, digestive glands, and hemolymph were extracted and analyzed after three different exposure times using a suite of biomarkers (EROD, DBF, GST, GPX, LPO, DNA damage, ChE, and lysosomal membrane stability [LMS]). After 48 and 96 h of exposure, EROD, DBF, GST, GPX activities and DNA strand breaks in the gills increased significantly after 48 and 96 h of exposure. Alterations in LMS were also observed in the mussels exposed to all crack concentrations after 96 and 168 h. Our results demonstrated that crack cocaine is metabolized by CYP-like and GST activities in the gills. GPX was not able to prevent primary genetic damage, and cytotoxic effects in the hemocytes were also observed in a dose- and time-dependent response. Our study shows that the introduction of illicit drugs into coastal ecosystems must be considered a threat to marine organisms.

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  • IPEN-DOC 24768

    OLIVEIRA, ERICA A. de ; FAINTUCH, BLUMA L. ; SEO, DANIELE ; BARBEZAN, ANGELICA B. ; FUNARI, ANA ; TARGINO, ROSELAINE C.; MORO, ANA M.. Radiolabeled GX1 peptide for tumor angiogenesis imaging. Applied Biochemistry and Biotechnology, p. 1-12, 2018. DOI: 10.1007/s12010-018-2700-z

    Abstract: Early and accurate detection of primary or metastatic tumors is of great value in staging, treatment management, and prognosis. Tumor angiogenesis plays an essential role in the growth, invasion, and metastatic spread of solid cancers, and so, is a promising approach for tumor imaging. The GX1 (CGNSNPKSC) peptide was identified by phage display library and has been investigated as a marker for human cancers. This study aims to evaluate the 99mTc-HYNIC-PEG4-c (GX1) as a biomarker for tumor imaging. Our results showed that GX1 specifically binds to tumor cells in vitro. SKMEL28 and MDA-MB231 cells achieved total binding peak at 60 min of incubation. For B16F10 and MKN45 cells, the total and specific binding were similar during all time points, while A549 cell line showed rapid cellular total uptake of the tracer at 30 min of incubation. Biodistribution showed low non-specific uptakes and rapid renal excretion. Melanoma tumors showed enhanced GX1 uptake in animal model at 60 min, and it was significantly blocked by cold peptide. The radiotracer showed tumor specificity, especially in melanomas that are highly vascularized tumors. In this sense, it should be considered in future studies, aiming to evaluate degree of angiogenesis, progression, and invasion of tumors.

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  • IPEN-DOC 24767

    OLIVEIRA, FELIPE L. de; SANTOS, SOFIA N. dos ; RICON, LAUREMILIA; COSTA, THAYSE P. da; PEREIRA, JONATHAS X.; BRAND, CAMILA; FERMINO, MARISE L.; CHAMMAS, ROGER; BERNARDES, EMERSON S. ; EL-CHEIKH, MARCIA C.. Lack of galectin-3 modifies differentially Notch ligands in bone marrow and spleen stromal cells interfering with B cell differentiation. Scientific Reports, v. 8, n. 3495, p. 1-14, 2018. DOI: 10.1038/s41598-018-21409-7

    Abstract: Galectin-3 (Gal-3) is a beta-galactoside binding protein that controls cell-cell and cell-extracellular matrix interactions. In lymphoid organs, gal-3 inhibits B cell differentiation by mechanisms poorly understood. The B cell development is dependent on tissue organization and stromal cell signaling, including IL-7 and Notch pathways. Here, we investigate possible mechanisms that gal-3 interferes during B lymphocyte differentiation in the bone marrow (BM) and spleen. The BM of gal-3-deficient mice (Lgals3(-/-)mice) was evidenced by elevated numbers of B220(+)CD19(+)c-Kit(+)IL-7R(+) progenitor B cells. In parallel, CD45-bone marrow stromal cells expressed high levels of mRNA IL-7, Notch ligands (Jagged-1 and Delta-like 4), and transcription factors (Hes-1, Hey-1, Hey-2 and Hey-L). The spleen of Lgals3(-/-)mice was hallmarked by marginal zone disorganization, high number of IgM(+) IgD(+) B cells and CD138(+)plasma cells, overexpression of Notch ligands (Jagged-1, Delta-like 1 and Delta-like 4) by stromal cells and Hey-1. Morever, IgM(+) IgD(+) B cells and B220(+)CD138(+)CXCR4(+) plasmablasts were significantly increased in the BM and blood of Lgals3(-/-)mice. For the first time, we demonstrated that gal-3 inhibits Notch signaling activation in lymphoid organs regulating earlier and terminal events of B cell differentiation.

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  • IPEN-DOC 24766

    OLIVEIRA, LEANDRO A. de; CORREA, OLANDIR V. ; SANTOS, DEMETRIO J. dos; PAEZ, ALEJANDRO A.Z.; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.. Effect of silicate-based films on the corrosion behavior of the API 5L X80 pipeline steel. Corrosion Science, v. 139, p. 21-34, 2018. DOI: 10.1016/j.corsci.2018.04.035

    Abstract: The aim of this work was to investigate the effect of silicate-based films on the corrosion resistance of the API 5L X80 steel in carbonate-bicarbonate solution at room temperature. The films were electrochemically obtained by anodic and cathodic treatments and by immersion in 1.0 M sodium metasilicate solution. The corrosion behavior was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization. Film morphology was examined by scanning electron microscopy. Adhesion strength was measured by pull-off tests. The chemical composition was evaluated by X-ray photoelectron spectroscopy. The anodic film yielded the best corrosion resistance (protection efficiency 83%). The protection mechanism is discussed.

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  • IPEN-DOC 24765

    FRANQUETTO, PAULO R. ; MATTAR NETO, MIGUEL . Experimental residual stress and geometric imperfections on pressure hull instability analysis. Journal of Offshore Mechanics and Arctic Engineering, v. 140, n. 3, 2018. DOI: 10.1115/1.4038582

    Abstract: Residual stress produced by cold bending and welding processes contributes to the collapse pressure reduction of submarine hulls. Usually, the residual stress profiles used to quantify this reduction are obtained from analytical or numerical models. However, such models have limitations to take into account cold bending and welding in the same time. Hence, experimental analyses are necessary to better quantify the residual stress. Based on that, this paper presents residual stress experimental results obtained at six points on a pressure hull prototype using X-ray portable system. Based on these results, the residual stress profiles through the material thickness were estimated for each region on the frame by using a polynomial approximation. These profiles were introduced in a nonlinear finite element numerical model to study the collapse pressure reduction. Experimental results available on the literature were also used. Material and geometric nonlinearities were considered in the analysis. The results show that the residual stress reduces the collapse pressure as part of the frame web has stress level higher than the material yield. The preload introduced by the residual stress plays a less important role for the collapse pressure reduction at higher out-of-roundness and out-of-straightness defect amplitudes.

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  • IPEN-DOC 24764

    NEGRO, MIGUEL L.M. ; DURAZZO, MICHELANGELO ; MESQUITA, MARCO A. de; CARVALHO, ELITA F.U. de ; MESQUITA, ROBERTO N. de ; ANDRADE, DELVONEI A. de . Studies on capacity expansion of fuel plants for nuclear research reactors. World Journal of Nuclear Science and Technology, v. 8, n. 2, p. 38-53, 2018. DOI: 10.4236/wjnst.2018.82005

    Abstract: The demand for nuclear fuel for research reactors is rising worldwide. Thus, the production facilities of this kind of fuel need reliable guidance on how to augment their production in order to meet the increasing demand efficiently and safely. We proposed a specific procedure for increasing production ca-pacity. That procedure was tested with data from a real plant, which produces plate-type fuel elements loaded with LEU U3Si2-Al fuel. The test was made by means of discrete event simulation, and the results indicated the proposed procedure is efficient in raising production capacity.

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  • IPEN-DOC 24763

    NASCIMENTO, M.H.M.; FRANCO, M.K.K.D. ; YOKAICHYIA, F.; PAULA, E. de; LOMBELLO, C.B.; ARAUJO, D.R. de. Hyaluronic acid in Pluronic F-127/F-108 hydrogels for postoperative pain in arthroplasties: Influence on physico-chemical properties and structural requirements for sustained drug-release. International Journal of Biological Macromolecules, v. 111, p. 1245-1254, 2018. DOI: 10.1016/j.ijbiomac.2018.01.064

    Abstract: In this study,we reported the hyaluronic acid (HA) on supramolecular structure of Pluronic F-127 (PLF-127) and/ or Pluronic F-108 (PLF-127) hydrogels, as well as their effects on release mechanisms, looking forward their application as lidocaine (LDC) drug-delivery systems in arthroplastic surgeries.We have studied the HA-micelle interaction using Dynamic Light Scattering (DLS), themicellization and sol-gel transition processes by Differential Scanning Calorimetry (DSC) and Rheology., of PL-based hydrogels and. The presence of HA provided the formation of larger micellar dimensions from ~26.0 to 42.4 nm. The incorporation of HA did not change the micellization temperatures and stabilized hydrogels rheological properties (G′ N G″), showing no interference on PLthermoreversible properties. Small-Angle-X-ray Scattering (SAXS) patterns revealed that HA incorporation effects were pronounced for PLF-127 and PLF-108 systems, showing transitions from lamellar to hexagonal phase organization (HA-PLF-127) and structural changes from cubic to gyroid and/or cubic to lamellar. The HA insertion effects were also observed on drug release profiles, since lower LDC release constants (Krel = 0.24–0.41 mM·h−1) were observed for HA-PLF-127, that presented a hexagonal phase organization. Furthermore, the HA-PL systems presented reduced in vitro cytotoxic effects, pointed out their tendency to selfassembly and possible application as drug delivery systems.

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  • IPEN-DOC 24761

    MOREIRA, GREGORI de A. ; GUERRERO-RASCADO, JUAN L.; BENAVENT-OLTRA, JOSE; ORTIZ-AMEZCUA, PABLO; ROMAN, ROBERTO; LANDULFO, EDUARDO ; ALADOS-ARBOLEDAS, LUCAS. Studying turbulence by remote sensing systems during slope-2016 campaign. EPJ Web of Conferences, v. 176, n. 06010, p. 1-4, 2018. DOI: 10.1051/epjconf/201817606010

    Abstract: The Planetary Boundary Layer (PBL) is the lowermost part of the troposphere. In this work, we analysed some high order moments and PBL height detected continuously by three remote sensing systems: an elastic lidar, a Doppler lidar and a passive Microwave Radiometer, during the SLOPE-2016 campaign, which was held in Granada from May to August 2016. This study confirms the feasibility of these systems for the characterization of the PBL, helping us to justify and understand its behaviour along the day.

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  • IPEN-DOC 24760

    MIRANDA, G.S.; OLIVEIRA, C.C.; SILVA, T.B.S.C.; STELLATO, T.B. ; MONTEIRO, L.R. ; MARQUES, J.R. ; FAUSTINO, M.G. ; SOARES, S.M.V.; ULRICH, J.C. ; PIRES, M.A.F. ; COTRIM, M.E.B. . Control chart on semi analytical weighting. Journal of Physics: Conference Series, v. 975, n. 012005, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012005

    Abstract: Semi-analytical balance verification intends to assess the balance performance using graphs that illustrate measurement dispersion, trough time, and to demonstrate measurements were performed in a reliable manner. This study presents internal quality control of a semianalytical balance (GEHAKA BG400) using control charts. From 2013 to 2016, 2 weight standards were monitored before any balance operation. This work intended to evaluate if any significant difference or bias were presented on weighting procedure over time, to check the generated data reliability. This work also exemplifies how control intervals are established.

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  • IPEN-DOC 24759

    MILAGRE, MARIANA X. ; MOGILI, NAGA V.; DONATUS, UYIME ; GIORJAO, RAFAEL A.R.; TERADA, MAYSA; ARAUJO, JOAO V.S. ; MACHADO, CARULINE S.C. ; COSTA, ISOLDA . On the microstructure characterization of the AA2098-T351 alloy welded by FSW. Materials Characterization, v. 140, p. 233-246, 2018. DOI: 10.1016/j.matchar.2018.04.015

    Abstract: The complex structure of the AA2098-T351 alloy welded by friction stir welding (FSW) was investigated by transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and microhardness measurements. Thermal modelling process of the FSW process was carried out by soldering thermocouples at distances of 6, 9 and 12 mm from the weld centerline, and thermocouple measurements were used as input data into the model. Finite element software COMSOL v5.2 was used for data analysis. The prevailing phases in the base metal (BM) are T1 (Al2CuLi) theta' (Al2Cu), delta'/beta'(Al-3(Li,Zr)) and Omega (Al2Cu). In the heat affected zone (HAZ), either in the retreating or advancing sides, theta' phase was not identified. In the thermomechanical affected zone (TMAZ), T1, delta'/beta', GP zones phase were detected in the retreating side, whereas T1 and Guinier-Preston (GP) zones were not observed in the advancing side. This result supports the asymmetric behavior observed in the microhardness profile of the weld. In the stir zone (SZ), GP zones, T1, delta'/beta' (Al-3(Li,Zr)) and Omega were identified.

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  • IPEN-DOC 24758

    MESQUITA, ROBERTO N. de ; CASTRO, LEONARDO F. ; TORRES, WALMIR M. ; ROCHA, MARCELO da S. ; UMBEHAUN, PEDRO E. ; ANDRADE, DELVONEI A. ; SABUNDJIAN, GAIANE ; MASOTTI, PAULO H.F. . Classification of natural circulation two-phase flow image patterns based on self-organizing maps of full frame DCT coefficients. Nuclear Engineering and Design, v. 335, p. 161-171, 2018. DOI: 10.1016/j.nucengdes.2018.05.019

    Abstract: Many of the recent nuclear power plant projects use natural circulation as heat removal mechanism. The accuracy of heat transfer parameters estimation has been improved through models that require precise prediction of two-phase flow pattern transitions. Image patterns of natural circulation instabilities were used to construct an automated classification system based on Self-Organizing Maps (SOMs). The system is used to investigate the more appropriate image features to obtain classification success. An efficient automated classification system based on image features can enable better and faster experimental procedures on two-phase flow phenomena studies. A comparison with a previous fuzzy inference study was foreseen to obtain classification power improvements. In the present work, frequency domain image features were used to characterize three different natural circulation two-phase flow instability stages to serve as input to a SOM clustering algorithm. Full-Frame Discrete Cosine Transform (FFDCT) coefficients were obtained for 32 image samples for each instability stage and were organized as input database for SOM training. A systematic training/test methodology was used to verify the classification method. Image database was obtained from two-phase flow experiments performed on the Natural Circulation Facility (NCF) at Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN), Brazil. A mean right classification rate of 88.75% was obtained for SOMs trained with 50% of database. A mean right classificationrate of 93.98% was obtained for SOMs trained with 75% of data. These mean rates were obtained through 1000 different randomly sampled training data. FFDCT proved to be a very efficient and compact image feature to improve image-based classification systems. Fuzzy inference showed to be more flexible and able to adapt to simpler statistical features from only one image profile. FFDCT features resulted in more precise results when applied to a SOM neural network, though had to be applied to the full original grayscale matrix for all flow images to be classified.

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  • IPEN-DOC 24757

    MARQUES, J.R. ; FAUSTINO, M.G. ; MONTEIRO, L.R. ; ULRICH, J.C. ; PIRES, M.A.F. ; COTRIM, M.E.B. . Is my bottom-up uncertainty estimation on metal measurement adequate?. Journal of Physics: Conference Series, v. 975, n. 012009, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012009

    Abstract: Is the estimated uncertainty under GUM recommendation associated with metal measurement adequately estimated? How to evaluate if the measurement uncertainty really covers all uncertainty that is associated with the analytical procedure? Considering that, many laboratories frequently underestimate or less frequently overestimate uncertainties on its results; this paper presents the evaluation of estimated uncertainties on two ICP-OES procedures of seven metal measurements according to GUM approach. Horwitz function and proficiency tests scaled standard uncertainties were used in this evaluation. Our data shows that most elements expanded uncertainties were from two to four times underestimated. Possible causes and corrections are discussed herein.

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  • IPEN-DOC 24756

    MARQUES, MARCIA T.A. ; MOREIRA, GREGORI de A. ; PINERO, MACIEL; OLIVEIRA, AMAURI P.; LANDULFO, EDUARDO . Estimating the planetary boundary layer height from radiosonde and doppler lidar measurements in the city of São Paulo - Brazil. EPJ Web of Conferences, v. 176, n. 06015, p. 1-4, 2018. DOI: 10.1051/epjconf/201817606015

    Abstract: This study aims to compare the planetary boundary layer height (PBLH) values estimated by radiosonde data through the bulk Richardson number (BRN) method and by Doppler lidar measurements through the Carrier to Noise Ratio (CNR) method, which corresponds to the maximum of the variance of CNR profile. The measurement campaign was carried during the summer of 2015/2016 in the city of São Paulo. Despite the conceptual difference between these methods, the results show great agreement between them.

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  • IPEN-DOC 24755

    MARQUES, L.S.; DE MIN, A.; ROCHA-JUNIOR, E.R.V.; BABINSKI, M.; BELLIENI, G.; FIGUEIREDO, A.M.G. . Elemental and Sr-Nd-Pb isotope geochemistry of the Florianópolis Dyke Swarm (Paraná Magmatic Province): crustal contamination and mantle source constraints. Journal of Volcanology and Geothermal Research, v. 355, n. SI, p. 149-164, 2018. DOI: 10.1016/j.jvolgeores.2017.07.005

    Abstract: The Florianópolis Dyke Swarm is located in Santa Catarina Island, comprising also the adjacent continental area, and belongs to the Paraná Magmatic Province (PMP). The dyke outcrops in the island are 0.1–70 m thick and most of them are coast-parallel (NE-SWtrending), with subordinate NW-SE trending. The vast majority of the dykes has SiO2 varying from 50 to 55 wt% and relatively high-Ti (TiO2 N 3 wt%) contents and these rocks were divided using the criteria commonly used to distinguish the different magma-types identified in the volcanic rocks fromthe PMP. The Urubici dykes (Sr N 550 μg/g) are themost abundant and some of them experienced crustal contamination reaching to 10%, as evidenced by low P2O5/K2O (0.30–0.21), high (Rb/Ba)PM (1.0–2.2), and radiogenic Sr and Pb isotope compositions (87Sr/86Sri up to 0.70716 (back to 125 Ma) and 206Pb/204Pbm up to 19.093). The Pitanga (Sr b 550 μg/g) and the basaltic trachyandesite dykes are less abundant and almost all of them were also substantially affected by at least 15% of crustal assimilation, evidenced by high (Rb/Ba)PM (up to 2.6) and Sr (87Sr/86Sri = 0.70737–0.71758) and Pb (206Pb/204Pbm = 18.446–19.441) isotope ratios, as well as low P2O5/K2O values (0.30–0.18). The low-Ti (TiO2 b 2 wt%) dykes are scarce and show a large compositional variability (SiO2: 50.4–64.5 wt%), with similar geochemical characteristics of the low-Ti volcanic rocks (Gramado-Palmas) from southern PMP, although the most primitive dykes show hybrid characteristics of Ribeira and Esmeralda magmas. The presence of granitic xenoliths with border reactions and dykeswith diffuse contacts indicate that crustal contamination probably occurred by assimilation from re-melted the host rocks. Considering only the high-Ti Urubici dykes that were not affected by crustal contamination, the Sr, Nd and Pb isotope mixing modelling indicates the participation of a heterogeneous metasomatized (refertilized) subcontinental lithospheric mantle (SCLM). This mantle source was originated by partial melting of a depleted sublithospheric mantle (DMM – Depleted Mantle MORB), which was hybridized by addition of pyroxenite (b5%) and carbonatite (up to 2%) melts. The isotope mixing modelling also points to a significant participation (up to 50%) of Archean SCLM, not evidenced in the mantle sources of the northern PMP high-Ti Pitanga flows (dominated by Neoproterozoic SCLM).

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  • IPEN-DOC 24754

    MARANI, DEBORA; MORAES, LETICIA P.R. ; GUALANDRIS, FABRIZIO; SANNA, SIMONE; FLORIO, DANIEL Z. de; ESPOSITO, VINCENZO; FONSECA, FABIO C. . Nucleation front instability in two-dimensional (2D) nanosheet gadolinium-doped cerium oxide (CGO) formation. CrystEngComm, v. 20, n. 10, p. 1405-1410, 2018. DOI: 10.1039/c7ce01737e

    Abstract: Herein we report for the first time the synthesis of ceramic-organic three-dimensional (3D) layered gadolinium-doped cerium oxide (Ce1-XGdXO2-delta,CGO) and its exfoliation into two-dimensional (2D) nano-sheets. We adopt a water-based synthetic route via a homogenous precipitation approach at low temperatures (10-80 degrees C). The reaction conditions are tuned to investigate the effects of thermal energy on the final morphology. A low temperature (40 degrees C) morphological transition from nanoparticles (1D) to two-dimensional (2D) nanosheets is observed and associated with a low thermal energy transition of ca. 2.6 kJ mol(-1). For the 3D-layered material, exfoliation experiments are conducted in water/ethanol solutions. Systems at volume fractions ranging from 0.15 to 0.35 are demonstrated to promote under ultrasonic treatment the delamination into 2D nanosheets.

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  • IPEN-DOC 24753

    MANTECON, JAVIER G. ; MATTAR NETO, MIGUEL . Numerical methodology for fluid-structure interaction analysis of nuclear fuel plates under axial flow conditions. Nuclear Engineering and Design, v. 333, p. 76-86, 2018. DOI: 10.1016/j.nucengdes.2018.04.009

    Abstract: Shell-type fuel elements are widely used in nuclear research reactors. The nuclear fuel is contained in parallel shells, flat or curved, that are separated by narrow channels through which the fluid flows to remove the heat generated by fission reactions. A major problem of this fuel assembly design is the hydraulic instability of the shells caused by the high flow velocities. The objective of the study presented here is the development of a fluid-structure interaction methodology to investigate numerically the onset of hydroelastic instability of flat-shell-type fuel elements, also known as plate-type fuel assemblies, under axial flow conditions. The system analyzed consists of two nuclear fuel plates bounded by three-equal coolant channels. It is developed using the commercial codes ANSYS CFX for modeling the fluid flow and ANSYS Mechanical to model the plates. The fluid-structure interaction methodology predicts a behavior consistent with other theoretical and experimental works. Particularly, the maximum deflection of the plates is detected at the leading edge and it is a linear function of the square of the fluid velocity up to the Miller’s theoretical value. For velocities above this value, a nonlinear relationship is observed. This relationship indicates that structural changes are taking place in the plates. Furthermore, for fluid velocities greater than the Miller’s velocity, an extra deflection peak is observed near the trailing edge of the plates. Thus, structural alterations also happen along the length of the flat-shells.

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  • IPEN-DOC 24751

    GONZALES-LORENZO, CARLOS D.; WATANABE, SHIGUEO; CANO, NILO F.; AYALA-ARENAS, JORGE S.; BUENO, CARMEN C. . Synthetic polycrystals of CaSiO3 un-doped and Cd, B, Dy, Eu-doped for gamma and neutron detection. Journal of Luminescence, v. 201, p. 5-10, 2018. DOI: 10.1016/j.jlumin.2018.04.037

    Abstract: The undoped and B, Cd, Dy, Eu doped synthetic CaSiO3 polycrystals were produced in the laboratory. They are very sensitive γ-ray detectors with main prominent TL peak occurring at about 270 °C, this peak was obtained using 4 °C/s heating rate. The TL behavior changes very little by doping with B, Cd and Dy while Eu doping brings changes. These minerals can be used also for neutron dosimetry. Thermal neutrons react with Ca, Si and O through (n, γ) process and γ emitted in this reaction added to γ-rays of the reactor that produces thermal neutrons and are responsible for induction of thermoluminiscence. The TL response of CaSiO3 is linear for dose < 10 Gy and then has a supralinear behavior up to about 7 kGy and saturating beyond.

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  • IPEN-DOC 24750

    LOPES, FABIO J.S. ; GUERRERO-RASCADO, JUAN L.; BENAVENT-OLTRA, JOSE A.; ROMAN, ROBERTO; MOREIRA, GREGORI A. ; MARQUES, MARCIA T.A. ; SILVA, JONATAN J. da ; ALADOS-ARBOLEDAS, LUCAS; ARTAXO, PAULO; LANDULFO, EDUARDO . Rehearsal for assessment of atmospheric optical properties during biomass burning events and long-range transportation episodes at metropolitan area of São Paulo-Brazil (RAPEL). EPJ Web of Conferences, v. 176, n. 08011, p. 1-4, 2018. DOI: 10.1051/epjconf/201817608011

    Abstract: During the period of August-September 2016 an intensive campaign was carried out to assess aerosol properties in São Paulo-Brazil aiming to detect long-range aerosol transport events and to characterize the instrument regarding data quality. Aerosol optical properties retrieved by the GALION - LALINET SPU lidar station and collocated AERONET sunphotometer system are presented as extinction/ backscatter vertical profiles with microphysical products retrieved with GRASP inversion algorithm.

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  • IPEN-DOC 24749

    LEVY, D.S. ; SORDI, G.M.A.A. ; VILLAVICENCIO, A.L.C.H. . Construindo pontes entre ciência e sociedade: divulgação científica sobre irradiação de alimentos. Brazilian Journal of Radiation Sciences, v. 6, n. 1, p. 01-13, 2018. DOI: 10.15392/bjrs.v6i1.343

    Abstract: A irradiação de alimentos é uma técnica de preservação segura e eficaz para eliminar insetos e reduzir microrganismos prejudiciais à saúde humana. O processo contribui para inibir o brotamento e retardar o amadurecimento dos alimentos, prolongando a vida útil de frutas e legumes frescos. Entretanto, dentre uma grande parcela da população brasileira, ainda há grande desinformação sobre as aplicações pacíficas das ciências nucleares. Não raramente a mídia e as redes sociais tendem a associar a radiação ionizante a armas nucleares e acidentes de grandes proporções. A desinformação compromete a percepção do público: consumidores acabam por associar alimentos irradiados a alimentos radioativos ou contaminados. O público demonstra grandes preocupações quanto aos efeitos negativos das radiações para a saúde e riscos de contaminação ambiental. Os julgamentos e tomadas de decisões por parte da sociedade estão diretamente ligados à sua percepção dos riscos e benefícios advindos da Tecnologa Nuclear. Este artigo apresenta algumas considerações sobre as percepções do público a respeito dos alimentos irradiados, bem como algumas ações de divulgação científica, para aproximar ciência e sociedade. Cabe à comunidade científica construir novas pontes entre as ciências nucleares e o público leigo, oferecendo uma perspectiva mais ampla sobre as aplicações pacíficas das radiações ionizantes e suas contribuições na vida cotidiana.

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  • IPEN-DOC 24748

    LAPENA, MAURO H.; MARINUCCI, GERSON . Mechanical characterization of basalt and glass fiber epoxy composite tube. Materials Research - Ibero-American Journal of Materials, v. 21, n. 1, p. 1-7, 2018. DOI: 10.1590/1980-5373-MR-2017-0324

    Abstract: The application of basalt fibers are possible in many areas thanks to its multiple and good properties. It exhibits excellent resistance to alkalis, similar to glass fiber, at a much lower cost than carbon and aramid fibers In the present paper, a comparative study on mechanical properties of basalt and E-glass fiber composites was performed. Results of apparent hoop tensile strength test of ring specimens cut from tubes and the interlaminar shear stress (ILSS) test are presented Tensile tests using split disk method provide reasonably accurate properties with regard to the apparent hoop tensile strength of polymer reinforced composites Comparison between the two tubes showed higher basalt fiber composite performance on apparent hoop tensile strength (45% higher) and on the interfacial property interlaminar shear stress (ILSS) (11% higher) New data obtained in this work on basalt fiber composite tubes confirm the literature for basalt fiber composite with other geometries, where it overcomes mechanical properties of the widely used glass fiber composites.

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  • IPEN-DOC 24747

    LANGE, CAMILA N. ; FIGUEIREDO, ANA M.G. ; ENZWEILER, JACINTA; MONTEIRO, LUCILENA R. . Potentially toxic elements downward mobility in an impounded vehicle scrapyard. Journal of Radioanalytical and Nuclear Chemistry, v. 316, n. 2, p. 819-830, 2018. DOI: 10.1007/s10967-018-5729-0

    Abstract: In Brazil impounded vehicle scrapyards (IVS) are often overcrowded and may pose a source of potentially toxic elements (PTEs). In this study, PTEs content in soil cores and groundwater of an IVS located at a municipality of the So Paulo metropolitan region was assessed. INAA, XRF and ICP-MS were the analytical techniques employed. PTEs results and statistical approaches indicated that As, Pb, Ni, Cu and Nb are mostly anthropic. Pb, Cu, Ni and Nb mass fraction increased with depth indicating some downward mobility. Arsenic may represent a moderate to very high potential ecological risk. PTEs groundwater levels were bellow drinking water recommendation limits.

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  • IPEN-DOC 24745

    LANDULFO, EDUARDO ; LOPES, FABIO ; RISTORI, PABLO; QUEL, EDUARDO; OTERO, LIDIA; FORNO, RICARDO; SANCHEZ, MARIA F.; BARBOSA, HENRIQUE; GOUVEIA, DIEGO; SANTOS, AMANDA V.; BASTIDAS, ALVARO; NISPERUZA, DANIEL. South american aerosol tracking - LALINET. EPJ Web of Conferences, v. 176, n. 09009, p. 1-4, 2018. DOI: 10.1051/epjconf/201817609009

    Abstract: LALINET lidar stations were used to track down aerosols generated over Amazon region and transported over the continent. These data were merged with collocated Aeronet stations in order to help in their identification together with HYSPLIT simulations. The results show potential indication of how aerosol can age in their long transport over regions South and Westward from the source areas by change of their optical properties.

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  • IPEN-DOC 24744

    LANDULFO, EDUARDO ; LOPES, FABIO ; MOREIRA, GREGORI A. ; SILVA, JONATAN da ; RISTORI, PABLO; QUEL, EDUARDO; OTERO, LIDIA; PALLOTA, JUAN V.; HERRERA, MILAGROS; SALVADOR, JACOBO; BALI, JUAN L.; WOLFRAM, ELIAM; ETALA, PAULA; BARBERO, ALBANE; FORNO, RICARDO; SANCHEZ, MARIA F.; BARBOSA, HENRIQUE; GOUVEIA, DIEGO; SANTOS, AMANDA V.; HOELZEMANN, JUDITH; FERNANDEZ, JOSE H.; GUEDES, ANDERSON; SILVA, ANTONIETA; BARJA, BORIS; ZAMORANO, FELIX; LEGUE, RAUL P.; BASTIDAS, ALVARO; ZABALA, MARIBEL V.; VELEZ, JUAN; NISPERUZA, DANIEL; MONTILLA, ELENA; ARREDONDO, RENE E.; MARRERO, JUAN C.A.; VEGA, ALBERTH R.; ALADOS-ARBOLEDAS, LUCAS; GUERRERO-RASCADO, JUAN L.; SUGIMOTO, NOBUO; YOSHITAKA, JIN. Lalinet status - station expansion and lidar ratio systematic measurements. EPJ Web of Conferences, v. 176, n. 09002, p. 1-4, 2018. DOI: 10.1051/epjconf/201817609002

    Abstract: LALINET is expanding regionally to guarantee spatial coverage over South and Central Americas. One of the network goals is to obtain a set of regional representative aerosol optical properties such as particle backscatter, extinction and lidar ratio. Given the North-South extension and influence of distinct airmass circulation patterns it is paramount to distinguish these optical parameters in order to gain better perfomance in radiation transfer models. A set of lidar ratio data is presented.

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  • IPEN-DOC 24743

    KIDO, HUELITON W.; GABBAI-ARMELIN, PAULO R.; AVANZI, INGRID R.; SILVA, ANTONIO C. da ; FERNANDES, KELLY R.; FORTULAN, CARLOS A.; RENNO, ANA C.M.. Vacuumed collagen-impregnated bioglass scaffolds: characterization and influence on proliferation and differentiation of bone marrow stromal cells. Journal of Biomedical Materials Research Part B: applied biomaterials, v. xx, n. xx, p. XX-XX, 2018. DOI: 10.1002/jbm.b.34112

    Abstract: This study evaluated physical–chemical characteristics of a vacuumed collagen-impregnated bioglass (BG) scaffolds and bone marrow stromal cells (BMSCs) behavior on those composites. scanning electron microscope and energy dispersive xray spectroscope demonstrated collagen (Col) was successfully introduced into BG. Vacuum impregnation system has showed efficiency for Col impregnation in BG scaffolds (approximately 20 wt %). Furthermore, mass weight decreasing and more stabilized pH were observed over time for BG/Col upon incubation in phosphate buffered saline compared to plain BG under same conditions. Calcium evaluation (Ca assay) demonstrated higher calcium uptake for BG/Col samples compared to BG. In addition, BG samples presented hydroxyapatite crystals formation on its surface after 14 days in simulated body fluid solution, and signs of initial degradation were observed for BG and BG/Col after 21 days. Fourier transform infrared spectroscopy spectra for both groups indicated peaks for hydroxyapatite formation. Finally, a significant increase of BMSCs viability for both composites was observed compared to control group, but no increase of osteogenic differentiation-related gene expressions were found. In summary, BG/Col scaffolds have improved degradation, pH equilibrium and Ca mineralization over time, accompanied by hydroxyapatite formation. Moreover, both BG and BG/Col scaffolds were biocompatible and noncytotoxic, promoting a higher cell viability compared to control. Future investigations should focus on additional molecular and in vivo studies in order to evaluate biomaterial performance for bone tissue engineering applications.

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  • IPEN-DOC 24742

    KHAN, LATIF U.; ZAMBON, LUIS F.M.; SANTOS, JACINETE L.; RODRIGUES, RODRIGO V.; COSTA, LUELC S.; MURACA, DIEGO; PIROTA, KLEBER R.; FELINTO, MARIA C.F.C. ; MALTA, OSCAR L.; BRITO, HERMI F.. Red-emitting magnetic nanocomposites assembled from Ag-decorated Fe3O4@SiO2 and Y2O3:Eu3+: impact of iron-oxide/silver nanoparticles on Eu3+ emission. Chemistryselect, v. 3, n. 4, p. 1157-1167, 2018. DOI: 10.1002/slct.201702478

    Abstract: The new multistep approach for co-assembling magnetic iron oxide nanoflowers with red-emitting Y2O3:Eu3+ to form luminescent and magnetic nanocomposites was reported. The Fe3O4 core prepared by solvothermal method was layered by SiO2 shell and decorated with small size spherical Ag nanoparticles as well as further coated with Y2O3:Eu3+ luminophore. The nanoflower shape Fe3O4 core of size similar to 110 nm and crystalline cubic structure of bifunctional iron-oxide@Y2O3:Eu3+, Fe3O4@SiO2@Y2O3:Eu3+ and Fe3O4@SiO2-Ag@Y2O3:Eu3+ (1 mol%) nanomaterials were confirmed from X-rays diffraction, EDS spectra and transmission electron microscopy (TEM) images. The static magnetic measurements supported and manifested nonsuperparamagnetic behavior of the materials at 300 K. The iron oxides are usually luminescence quenchers. In order to rationalize this effect, their optical properties based on their emission spectral data and luminescence decay curves were studied. Experimental intensity parameters (Wl), lifetimes (t), intrinsic quantum yield (Q(Ln)(Ln)) as well as radiative (Arad) and non-radiative (Anrad) decay rates were calculated to probe the local chemical environment of the Eu3+ ion and to better understand the phenomena of iron oxide induced luminescence quenching. The highest value of the intrinsic quantum yield (Q(Ln)(Ln) = 74%) for the alpha-Fe2O3@Y2O3:Eu3+ (1 mol%) among all the luminescent and magnetic nanocomposites suggests that alpha-Fe2O3 phase induces a lower luminescence quenching then Fe3O4/g-Fe2O3. The SiO2 thin layer leads to improve the luminescence efficiency, whereas the Ag nanoparticles act as luminescence quencher. These novel Eu3+ nanomaterials may act as a red emitting layer for magnetic and light converting molecular devices.

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  • IPEN-DOC 24741

    ALLEGRINI JUNIOR, SERGIO; SILVA, ANTONIO C. da ; TSUJITA, MARISTELA; SALLES, MARCOS B.; GEHRKE, SERGIO A.; BRAGA, FRANCISCO J.C. . Amorphous calcium phosphate (ACP) in tissue repair process. Microscopy Research & Technique, v. 81, n. 6, p. 579-589, 2018. DOI: 10.1002/jemt.23013

    Abstract: Synthetic biomaterials submitted to new structural technologies have become ideal for the recovery of traumatized bone tissues and some bone substitutes such as bioactive glass, β‐Tricalcium phosphate (β‐TCP) and amorphous calcium phosphate (ACP) are being used in areas of tissue defects. For this study, ACP was produced in the form of fibers and then submitted to cytotoxicity testing. A sample of ACP was inserted into the mandibular region of a patient with a lost implant so after removal and curettage, the remaining bone site was filled with the ACP biomaterial. Preliminary cytotoxicity test was negative. After 15 weeks of healing, a titanium implant was inserted at the site. Clinical and radiographic follow‐up was conducted for 12 months and sequential radiographic analyses revealed tissue formation resembling spongy bone. Images under immunohistochemistry demonstrated efficient deposition and osteoconduction of the newly deposited tissue. Residual portion of the CaO:P2O5 outer layers served as a substrate for osteoid matrix deposition, aiding growth, and the results of fiber absorption favored maturation of the new bone tissue.

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  • IPEN-DOC 24739

    GUGLIOTTI, C. ; MORIYA, K.; TATUMI, S.; MITTANI, J.. Synthesis and luminescence studies of Tb-doped MgO-MgAl2O4-Mg2SiO4 ceramic for use in radiation dosimetry. Applied Radiation and Isotopes, v. 135, p. 219-223, 2018. DOI: 10.1016/j.apradiso.2018.01.040

    Abstract: In the present work, MgO ceramic samples with different terbium concentrations were produced and the Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) properties analyzed and discussed, aiming the use in radiation dosimetry. The samples were produced using MgO, Mg(NO3)(2)center dot 6H(2)O, Al2O3, SiO2 and Tb(NO3)(3)center dot 6H(2)O precursors in stoichiometric concentrations with five different terbium concentrations between 0.1 and 0.5 mol% and after, heat-treated at high temperature similar to 1500 degrees C. X-ray diffraction measurements on samples showed the formation of MgO as principal phase, and others in low concentration due to MgAl2O4, Mg(2)Sia(4) and Tb4O7 phases. The TL. glow curve of samples showed an intense and well-defined peak having the maximum at similar to 210 degrees C and other less intense at similar to 350 degrees C. The sample with 0.1 mol% of terbium concentration presented highest luminescence peak when compared to the other samples. The relationship between 210 degrees C TL peak intensity and dose was linear to doses between 1 and 20 Gy and the minimum detectable dose obtained by interpolation taking into account three times the standard deviation of the zero dose reading, was similar to 40 mu Gy. A fading of similar to 20% during the first 5 hours after irradiation of 210 degrees C peak was observed. TL emission spectra showed strong emission lines due to Tb3+ ion. The OSL signal presented a linear behavior to doses between 1 and 10 Gy using 532 nm wavelength stimulation.

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  • IPEN-DOC 24738

    GUEDES, ANDERSON G.; LANDULFO, EDUARDO ; MONTILLA-ROSERO, ELENA; LOPES, FABIO J.S. ; HOELZEMANN, JUDITH J.; FERNANDEZ, JOSE H.; SILVA, MARCOS P.A.; SANTOS, RENATA S.S.; GUERRERO-RASCADO, JUAN L.; ALADOS-ARBOLEDAS, LUCAS. Detection of saharan mineral dust aerosol transport over brazilian northeast through a depolarization lidar. EPJ Web of Conferences, v. 176, n. 05036, p. 1-4, 2018. DOI: 10.1051/epjconf/201817605036

    Abstract: In this study we present results of linear volume depolarization ratio profiles obtained by a depolarization lidar in operation in Natal, Brazil. The DUSTER system has 4 channels, namely: 1064, 532 s/p and 355 nm. This system is calibrated with a half-wave plate using the Δ90° methodology. The data obtained from this system is correlated with AERONET sunphotometer data, and, when available, CALIPSO satellite data. In addition a trajectory model (HYSPLIT) is used to calculate backward trajectories to assess the origin of the dust polluted air parcels. The objective is to create a transport database of Saharan dust.

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  • IPEN-DOC 24737

    GOUVEIA, DIEGO; BAARS, HOLGER; SEIFERT, PATRIC; WANDINGER, ULLA; BARBOSA, HENRIQUE; BARJA, BORIS; ARTAXO, PAULO; LOPES, FABIO ; LANDULFO, EDUARDO ; ANSMANN, ALBERT. Application of a multiple scattering model to estimate optical depth, lidar ratio and ice crystal effective radius of cirrus clouds observed with lidar. EPJ Web of Conferences, v. 176, n. 05037, p. 1-4, 2018. DOI: 10.1051/epjconf/201817605037

    Abstract: Lidar measurements of cirrus clouds are highly influenced by multiple scattering (MS). We therefore developed an iterative approach to correct elastic backscatter lidar signals for multiple scattering to obtain best estimates of single-scattering cloud optical depth and lidar ratio as well as of the ice crystal effective radius. The approach is based on the exploration of the effect of MS on the molecular backscatter signal returned from above cloud top.

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  • IPEN-DOC 24735

    FURIGO, ISADORA C.; MELO, HELEN M.; SILVA, NATALIA M.L. e; RAMOS-LOBO, ANGELA M.; TEIXEIRA, PRYSCILA D.S.; BUONFIGLIO, DANIELLA C.; WASINSKI, FREDERICK; LIMA, ELIANA R. ; HIGUTI, ELIZA ; PERONI, CIBELE N. ; BARTOLINI, PAOLO ; SOARES, CARLOS R.J. ; METZGER, MARTIN; FELICE, FERNANDA G. de; DONATO JUNIOR, JOSE. Brain STAT5 signaling modulates learning and memory formation. Brain Structure and Function, v. 223, n. 5, p. 2229-2241, 2018. DOI: 10.1007/s00429-018-1627-z

    Abstract: The signal transducer and activator of transcription 5 (STAT5) is a transcription factor recruited by numerous cytokines. STAT5 is important for several physiological functions, including body and tissue growth, mammary gland development, immune system and lipid metabolism. However, the role of STAT5 signaling for brain functions is still poorly investigated, especially regarding cognitive aspects. Therefore, the objective of the present study was to investigate whether brain STAT5 signaling modulates learning and memory formation. For this purpose, brain-specific STAT5 knockout (STAT5 KO) mice were studied in well-established memory tests. Initially, we confirmed a robust reduction in STAT5a and STAT5b mRNA levels in different brain structures of STAT5 KO mice. STAT5 KO mice showed no significant alterations in metabolism, growth, somatotropic axis and spontaneous locomotor activity. In contrast, brain-specific STAT5 ablation impaired learning and memory formation in the novel object recognition, Barnes maze and contextual fear conditioning tests. To unravel possible mechanisms that might underlie the memory deficits of STAT5 KO mice, we assessed neurogenesis in the hippocampus, but no significant differences were observed between groups. On the other hand, reduced insulin-like growth factor-1 (IGF-1) mRNA expression was found in the hippocampus and hypothalamus of STAT5 KO mice. These findings collectively indicate that brain STAT5 signaling is required to attain normal learning and memory. Therefore, STAT5 is an important downstream cellular mechanism shared by several cytokines to regulate cognitive functions.

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  • IPEN-DOC 24733

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . Constructal law of institutions within social organizations. Open Journal of Applied Sciences, v. 8, p. 103-125, 2018. DOI: 10.4236/ojapps.2018.83009

    Abstract: This work looked for a unifying theory between physical-biological domain and social sciences. Constructal law unified physical and biological domain by telling the general sense in which flow systems tend to evolve. Management theory looks for relations between institutions and human agency. Although being state of mind entities, institutions follow constructal law. This work proposed the main organization flows are information and credit. Biologic instincts derived from Darwinian natural selection are the driving or blocking forces of such flows. Once biologic instincts systematically block information and credit flows in large numbers, this work proposed every human organization must have institutions to inhibit some behaviors. Those institutions need to be present, at least partially, in formal rules of social groups. This way it is possible to predict expansion or downfall of human groups using objective and quantifiable data. Therefore, further studies may employ classical history to confirm this theory. This work analyzed some case studies to show qualitatively the application of proposed theory. Concluding, this work gave physically- biologically grounded guidance for institutional changes.

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  • IPEN-DOC 24732

    FONTES, MAYANA K.; GUSSO-CHOUERI, PALOMA K.; MARANHO, LUCIANE A.; ABESSA, DENIS M. de S.; MAZUR, WESLEY A.; CAMPOS, BRUNO G. de; GUIMARAES, LUCIANA L.; TOLEDO, MARCOS S. de; LEBRE, DANIEL ; MARQUES, JOYCE R. ; FELICIO, ANDREIA A.; CESAR, AUGUSTO; ALMEIDA, EDUARDO A.; PEREIRA, CAMILO D.S.. A tiered approach to assess effects of diclofenac on the brown mussel Perna perna: a contribution to characterize the hazard. Water Research, v. 132, p. 361-370, 2018. DOI: 10.1016/j.watres.2017.12.077

    Abstract: Pharmaceutical discharges into the aquatic ecosystem are of environmental concern and sewage treatment plants (STPs) have been pointed out as the major source of these compounds to coastal zones, where oceanic disposal of sewage occurs through submarine outfalls. Diclofenac (DCF) is one of the most frequently detected pharmaceuticals in water, but little is known about the effects on marine organisms. In this study, we employed a tiered approach involving the determination of environmental concentrations of DCF in marine water and the adverse biological effects for fertilization, embryo-larval development and biomarker responses of the mussel Perna perna. Results indicate that effects in fertilization rate and embryo-larval development were found in the order of mg$L 1. However, low concentrations of DCF (ng$L 1) significantly decreased the lysosomal membrane stability and COX activity, as well as triggered DNA damage, oxidative stress and changes in antioxidant defenses. Our results point to an environmental hazard at coastal ecosystems and suggest the need for improvements in the treatment of domestic wastewater aiming to reduce DCF concentrations, as well as regulation on current environmental legislation and monitoring of aquatic ecosystems.

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  • IPEN-DOC 24730

    FERREIRA JUNIOR, J.M.; OLIVEIRA, M. ; TRINDADE, G.F.; SANTOS, L.C.L.; TOMACHUK, C.R.; BAKER, M.A.. Development and characterisation of zinc oxalate conversion coatings on zinc. Corrosion Science, v. 137, p. 13-32, 2018. DOI: 10.1016/j.corsci.2018.03.011

    Abstract: The interactions between oxalic acid and zinc substrates have been studied through the deposition of zinc oxalate coating by immersion. The corrosion behaviour of zinc was investigated by surface observation and electrochemical impedance spectroscopy (EIS). Better protective properties were observed for samples treated with 10−1 M oxalic acid compared to other concentrations and the enrichment of corrosion product by Na was observed. The electrochemical results reveal that the oxalate coating increases corrosion protection in corrosive medium. It is proposed that the zinc oxalate coating formed act as a basis for anchoring zinc corrosion products forming simonkolleite improving corrosion resistance.

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  • IPEN-DOC 24729

    FAVARO, D.I.T. ; ROCHA, F.R. ; ANGELINI, M.; HENRIQUES, H.R.A.; SOARES, J.S.; SILVA, P.S.C. ; OLIVEIRA, S.M.B.. Metal and trace element assessments of bottom sediments from medium Tietê River basin, Sao Paulo State, Brazil: part II. Journal of Radioanalytical and Nuclear Chemistry, v. 316, n. 2, p. 805-818, 2018. DOI: 10.1007/s10967-018-5821-5

    Abstract: Concentration of metals in 15 bottom sediment samples from Tieteˆ River, a significantly polluted river, were assessed. Total and partial trace element concentrations were determined, and As, Cd, Cr, Cu, Ni and Zn were found above local reference values. These metals were also higher than the threshold effect level (TEL) in some sampling points and Zn was higher than probable effect level (PEL) oriented values in almost all sampling points. The most polluted points were identified from Tieteˆ to Barra Bonita Counties. Regarding sediment quality, this river is still polluted and precautions to minimize environmental problems caused by toxic metals to biota and to human health are necessary.

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  • IPEN-DOC 24728

    ERMAKOV, VIKTOR A.; SILVA FILHO, JOSE M.C. da; BONATO, LUIZ G.; MOGILI, NAGA V.V.; MONTORO, FABIANO E.; IIKAWA, FERNANDO; NOGUEIRA, ANA F.; CESAR, CARLOS L.; JIMENEZ-VILLAR, ERNESTO ; MARQUES, FRANCISCO C.. Three-dimensional superlattice of PbS quantum dots in flakes. ACS Omega, v. 3, n. 2, p. 2027-2032, 2018. DOI: 10.1021/acsomega.7b01791

    Abstract: In the last two decades, many experiments were conducted in self-organization of nanocrystals into two- and three-dimensional (3D) superlattices and the superlattices were synthesized and characterized by different techniques, revealing their unusual properties. Among all characterization techniques, X-ray diffraction (XRD) is the one that has allowed the confirmation of the 3D superlattice formation due to the presence of sharp and intense diffraction peaks. In this work, we study self-organized superlattices of quantum dots of PbS prepared by dropping a monodispersed colloidal solution on a glass substrate at different temperatures. We showed that the intensity of the low-angle XRD peaks depends strongly on the drying time (substrate temperature). We claim that the peaks are originated from the 3D superlattice. Scanning electron microscopy images show that this 3D superlattice (PbS quantum dots) is formed in flake’s shape, parallel to the substrate surface and randomly oriented in the perpendicular planes.

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  • IPEN-DOC 24727

    DONATUS, UYIME ; BERBEL, LARISSA O. ; COSTA, ISOLDA . Qualitative use of potentiodynamic polarization and anodic hydrogen evolution in the assessment of corrosion susceptibility in AA2198-T851 Al–Cu–Li alloy. Materials and Corrosion - Werkstoffe und Korrosion, p. 1-14, 2018. DOI: 10.1002/maco.201810108

    Abstract: In this study, the corrosion behavior of the AA2198-T851 and its friction stir weldment was used to show the qualitative use of potentiodynamic polarization and the effect of anodic hydrogen evolution (AHE). The results showed that some details can be revealed in the anodic arm of the polarization curves of an Al alloy above the breakdown potential with changes in cell configuration and electrolytes. In addition, AHEinterferes with the measured current density in the anodic arm, which in turn can be used to assess the extent of corrosion susceptibility and changes in anodic dissolution behavior of the alloy.

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  • IPEN-DOC 24726

    DONATUS, UYIME ; TERADA, MAYSA; OSPINA, CARLOS R.; QUEIROZ, FERNANDA M. ; BUGARIN, ALINE F.S. ; COSTA, ISOLDA . On the AA2198-T851 alloy microstructure and its correlation with localized corrosion behaviour. Corrosion Science, v. 131, p. 300-309, 2018. DOI: 10.1016/j.corsci.2017.12.001

    Abstract: The corrosion behaviour of AA2198-T851 alloy has been investigated using a combination of immersion tests and different microscopy techniques. Results showed that severe localized corrosion initiated within 1 h of corrosion immersion test in 0.01 mol L−1 NaCl solution. The corrosion mechanism in this alloy is intragranular and it propagates crystallographically. The propagation occurs through grain orientation dependent bands and it can be likened to the movement of dislocation through slip planes. Corrosion rings around stable pits result from pH variations. Secondary pits form around primary pits within corrosion rings and are preceded by hydrogen evolution.

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  • IPEN-DOC 24724

    COSTA, J.J.L.; NASCIMENTO, E.O. do; OLIVEIRA, L.N. de; CALDAS, L.V.E. . Pressure sound level measurements at an educational environment in Goiânia, Goiás, Brazil. Journal of Physics: Conference Series, v. 975, 2018. DOI: 10.1088/1742-6596/975/1/012055

    Abstract: In this work, 25 points located on the ground floor of the Federal Institute of Education, Science and Technology of Goias - IFG - Campus Goiânia, were analyzed in morning periods of two Saturdays. The pressure sound levels were measured at internal and external environments during routine activities seeking to perform an environmental monitoring at this institution. The initial hypothesis was that an amusement park (Mutirama Park) was responsible for originating noise pollution in the institute, but the results showed, within the campus environment, sound pressure levels in accordance with the Municipal legislation of Goiânia for all points.

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  • IPEN-DOC 24723

    COSTA, RENATA F. da; MARQUES, MARCIA T.A. ; MACEDO, FERNANDA de M.; ANDRADE, IZABEL da S. ; ARAUJO, ELAINE C. ; CORREA, THAIS ; SALANI, MARIA H.G. de A. ; LOPES, DANIEL S.; GUARDANI, MARIA L.G.; LANDULFO, EDUARDO ; GUARDANI, ROBERTO. Monitoring the industrial sources of aerosol in Cubatao, Brazil, using a scanning elastic lidar and a lidar doppler. EPJ Web of Conferences, v. 176, n. 04011, p. 1-4, 2018. DOI: 10.1051/epjconf/201817604011

    Abstract: Field campaigns with a scanning multiwavelength elastic lidar coupled with a Doppler system to monitor industrial atmospheric aerosol emissions were carried out, with the objective of monitoring aerosol emission sources and plume dispersion. Since the technique provides information on the spatial and temporal distribution of aerosol concentration, the implementation of a systematic monitoring procedure is proposed as a valuable tool in air quality monitoring applied to regions of interest.

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  • IPEN-DOC 24721

    CHAVES, K.C.B.; COSTA, E.M.; TEIXEIRA, L.F.; BELLINI, M.H. . Impact of endostatin gene therapy on myeloid-derived suppressor cells from a metastatic renal cell carcinoma. Experimental Oncology, v. 40, n. 1, p. 24-32, 2018.

    Abstract: Aim: To evaluate the role of endostatin (ES) gene therapy on myeloid-derived suppressor cells (MDSC) in a metastatic model of renal cell carcinoma (RCC). Materials and Methods: Balb/C mice bearing orthotopic Renca tumors were treated with NIH/3T3-LendSN or, as a control, with NIH/3T3-LXSN cells. At the end of in vivo experiment, plasma and tissue lung samples were collected. Plasma ES and granulocyte colony stimulating factor (G-CSF) levels were measured by ELISA and Milliplex, respectively. Quantification of CD11b+Gr-1+ cells and their subsets was performed by flow cytometry. Reactive oxygen species (ROS) production was measured in CD11b+Gr-1+ MDSC using the DCFDA marker by flow cytometry. Results: Metastatic RCC (mRCC) induced expansions of CD11b+Gr-1+ MDSC and promoted accumulation of these cells and their subtypes in lymphoid organ and metastases. ES treatment promoted low G-CSF plasmatic levels which were produced by the tumor microenvironment, reflecting the reduced metastatic accumulation of CD11b+Gr-1+ MDSC in the lungs. However, the therapy was selective for granulocytic cells, thus reducing the production of ROS. Conclusion: These findings confirm the expansion of MDSC during metastatic progression of RCC and indicate the important role of ES in reducing MDSC and possible use of ES therapy in combined anticancer treatment.

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  • IPEN-DOC 24720

    CARVALHO, SABRINA G.M.; MUCCILLO, ELIANA N.S. ; MUCCILLO, REGINALDO . Electrical behavior and microstructural features of electric field-assisted and conventionally sintered 3 mol % yttria-stabilized zirconia. Ceramics, v. 1, n. 1, p. 1-10, 2018. DOI: 10.3390/ceramics1010002

    Abstract: ZrO2: 3 mol % Y2O3 (3YSZ) polycrystalline pellets were sintered at 1400 C and by applying an alternating current (AC) electric field at 1000 C. An alumina sample holder with platinum wires for connecting the sample to a power supply was designed for the electric field-assisted sintering experiments. The apparent density was evaluated with the Archimedes technique, the grain size distribution by analysis of scanning electron microscopy images, and the electrical behavior by the impedance spectroscopy technique. Sintering with the application of AC electric fields to 3YSZ enhances its ionic conductivity. An explanation is proposed, based on the dissolution back to the bulk of chemical species, which are depleted at the grain boundaries, leading to an increase in the oxygen vacancy concentration. For the enhancement of the grain boundary conductivity, an explanation is given based on the diminution of the concentration of depleted chemical species, which migrate to the bulk. This migration leads to a decrease of the potential barrier of the space charge region, known to be responsible for blocking the oxide ions through the intergranular region. Moreover, the heterogeneity of the distribution of the grain sizes is ascribed to the skin effect, the tendency of the AC current density to be largest near the surface, decreasing towards the bulk.

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ATENÇÃO!

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

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

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

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


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