Eventos - Resumos

 

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  • IPEN-DOC 29307

    VILLANI, D. ; SAVI, M. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Development of a fused filament fabrication (FFF) 3D printed neck-thyroid phantom for multidisciplinary purposes. In: EUROPEAN CONGRESS OF MEDICAL PHYSICS, 4th, August 17-20, 2022, Dublin, Ireland. Abstract... 2022.

    Abstract: Purpose: Phantoms, devices that represent the human body, have been used in the fields of medical physics, physics and biomedical engineering since the beginning. The use of 3D printing and filaments commonly found commercially for the development of phantoms is being investigated recently. The application of this technique for the development of low-cost simulators requires a complex study of the interaction of printed materials with different types and qualities of radiation, as well as the characterization of print configurations. By making these measurements, it is possible to find methodologies so that they can correctly simulate human tissue. This study aims to describe the process of design and manufacture an anthropomorphic neck-thyroid phantom using a fused filament fabrication (FFF) 3D printer and tissue-equivalent materials for multidisciplinary purposes. Materials and Methods: To this study, the commercial phantom ATOM MAX 711, from CIRS, was used as an anatomical reference for the 3D modeling base of the neck-thyroid phantom. Commercially available PLA and ABS XCT-A developed at IPEN were used in the 3D printing process in order to simulate soft and bone tissues respectively. It was used the RAISE3D PRO 2 FFF printer from IPEN. The usability validation of the phantom was performed through the analysis of images from a computed tomography (CT) acquisition. The Hounsfield Units (HU) numbers were compared between the 3D printed and the ATOM MAX 711 phantoms to each type of tissue represented. A thyroid accessory was also developed on the purpose of immobilization of radioactive material with epoxy resin. Results: The modeling methodology of the 3D phantom of this study opens possibilities for using tomographic images of any objects, or even patients, to perform 3D prototyping of increasingly specific and customized simulators. The CT image analysis show great results on the analysis of the construction of the soft tissue with PLA filaments; construction of the bone tissues with ABS XCT-A; analysis of the construction of the thyroid accessory with epoxy resin; analysis of the spacing of the fit of the printed pieces; and analysis of image artifacts caused by the FFF technique. Conclusions: The developed phantom presents the desirable characteristics for applications in radiation protection, measurements of radioisotopes incorporated in the thyroid (both contamination counters and nuclear medicine detectors) and training of techniques of acquisition of images with X rays. It is a viable alternative to a tissue-equivalent phantom; and low cost when compared to other commercially available options.

  • IPEN-DOC 29296

    ZAMBONI, C.B. ; SALVADOR, V.L. ; LEWGOY, H.R. ; SILVA, R.Y.R.; MEDEIROS, I.M.M.A. . Sulfur concentration in saliva using EDXRF technique. In: ENCONTRO DE PRIMAVERA DA SOCIEDADE BRASILEIRA DE FÍSICA, 2.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 45.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 42.; RENAFAE WORKSHOP, 26-29 de setembro, 2022, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: In the last decade, human saliva has been used for clinical analyses by investigations of its molecular components, hormones, enzymes, proteins and more recently for inorganic elements. The major advantage for using saliva in diagnosis is the ease access collection and be non-invasive. Saliva consists mainly of water (~98%) in addition to electrolytes and enzymes. Particularly, sulfur levels in saliva can act as an indicator of an inflammatory process of the gingiva (gingivitis and halitosis), which has a high incidence in the Brazilian population. The World Health Organization (WHO) estimates that one in four adults has some type of bacterial infection. Specifically, halitosis (chronic bad breath) is overlooked and has several possible causes: cavities, broken fillings, and poor partial or full dentures cleaning. This oral dysfunction can be classified as physiological or pathological. Physiological halitosis is caused by inadequate oral hygiene. It is significantly related to symptoms of depression, while pathological halitosis is a result of chronic inflammatory periodontal disease. In this investigation, sulfur concentration in saliva were investigated using Energy Dispersive X-ray Fluorescence (EDXRF) technique. Unstimulated whole saliva samples (~3mL) were collected from healthy subject, in a dental office. All participants were inhabitants of São Paulo city. Samples were excited and measured using a portable X-Ray Spectrometer: Ag X-Ray target and Si Drift detector (25 mm2 x 500 μm /12.5 μm Be window) and counting time of 600s measured with 30kV and 10μA. The spectrometer was calibrated for sulfur using linear regression method for concentration up to 500 ppm. The availability of accurate reference value for sulfur in human saliva provides a scientific basis for biomedical research of specific diseases in oral cavity. In addition, the use of the XRF compact spectrometer to perform clinical tests on saliva is a fast and effective procedure, within the quality standards required by Good Laboratory Practices (GLP) for early diagnosis in dentistry.

  • IPEN-DOC 29295

    KOKA, A.C.S.S. ; ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; REDÍGOLO, M.M. . NAA and XRF techniques to investigate artistic paints. In: ENCONTRO DE PRIMAVERA DA SOCIEDADE BRASILEIRA DE FÍSICA, 2.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 45.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 42.; RENAFAE WORKSHOP, 26-29 de setembro, 2022, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: In this study, the multielemental characterization of artistic blue paints from the 90's and currently available ones in the Brazilian market was carried out using the Energy Dispersion X-Ray Fluorescence (EDXRF) and Neutron Activation Analysis techniques (NAA). These results aim to establish a reference database in the field. The EDXRF measurements was performed using portable X-ray spectrometer with Ag X-ray tube associated with a Si Drift detector (25 mm2 x 500 μm) with Be window (12.5 μm). The artistic paint samples were irradiated for 300 s using 30 kV and 5μA excitation. The quantitative analysis was performed using WinQXas software program (IAEA, version 1.3). The NAA measurements were performed in the nuclear reactor IEA-R1 (3.5- 4.5MW, pool type) at IPEN/CNEN-SP. Each sample was irradiated from minutes to hours and gamma counting was performed using HPGe detector (ORTEC-GEM 60195) coupled to an MCA (ORTEC - 919E). Concentration of all elements was obtained using the ATIVAÇÃO software. The results obtained by both techniques are in good agreement, in addition to being complementary. However, they do not correspond to the elemental content description provided by the manufacturer.

  • IPEN-DOC 29294

    ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; PECEQUILO, B.R.S. ; ESPOSITO, S.E.; PIMENTA, D.C.; SIMONS, S.M.. Traceability of the propolis produced by Scaptotrigona Aff Postica bee from Brazil using NAA technique. In: ENCONTRO DE PRIMAVERA DA SOCIEDADE BRASILEIRA DE FÍSICA, 2.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 45.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 42.; RENAFAE WORKSHOP, 26-29 de setembro, 2022, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: In the Northeast, meliponiculture presents itself as one of the zootechnical activities that has grown the most in recent years, due to its low implementation and maintenance cost, as well as a quick financial return. Meliponiculture is the creation of stingless bees (Meliponines) for the production and commercialization of beehives, honey, propolis, pollen and resins, in addition to these bees being the main agents of pollination and conservation of local biodiversity. The propolis produced by the Scaptotrigona Aff Postica bee (popularly known as the tubi bee) have several medical applications (bactericidal, fungicidal and virucidal), in addition to its use in the nutritional field. This species is found in the mainly in the Barra do Corda County (Maranhão) and it is the major source of income in the northeast region. Nowadays, food authentication has been a concern of producers and consumers around the world. For this reason, there is a growing need for reliable analytical techniques to provide an answer about food authenticity. With the goal for determining chemical descriptors for geographic origin (standardization), nuclear techniques are useful analytical tools with a highlight for Neutron Activation Analysis (NAA). The NAA measurement was performed in the nuclear reactor (IEA-R1, 3-4 MW, at IPEN). Propolis samples were collected monthly during a one year, directly from beehives of Scaptotrigona Aff Postica in a meliponary of Barra do Corda city (5° 30' 21'' S and 45° 14' 6'' W). The results were compared with two other species from south region. The database will aid in fraud detection of the propolis from the northeast region in Brazil.

  • IPEN-DOC 29293

    GIOVANNI, D.N.S. ; KOKA, A.C.S.S. ; ALMEIDA, M.R. ; ZAMBONI, C.B. . Young Scientist Project: a proposal to teach, demystify and disseminate nuclear physics. In: ENCONTRO DE PRIMAVERA DA SOCIEDADE BRASILEIRA DE FÍSICA, 2.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 45.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 42.; RENAFAE WORKSHOP, 26-29 de setembro, 2022, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: The use of Information and Communication Technologies (ICT) has facilitated the dissemination of nuclear knowledge and, at the same time, improved relations between specialists working in different areas of science. The growing number of initiatives, on the part of Research Centers, Universities, and even on an individual basis has been positive through social networks, websites, and blogs. The Young Scientist Project was created in 2019, by the team of the Spectroscopy and Spectrometry of Radiation Laboratory at IPEN, with the proposal to implement nuclear knowledge. The aim is to present alternative proposals for knowledge, application, and dissemination of science, with an emphasis on demystifying the nuclear sciences. The website (www.jovemcientista.com.br) design involves four menus: REPORTS where researchers talk about their career, challenges, and perspectives in the field; NUCLEAR MINUTE: where nuclear physics concepts are covered in one-minute videos; CURIOSITIES: a space where various topics are presented, whose objective is to dialogue between the various areas of scientific knowledge. In addition, within this menu, scientific content from other media is available in GARIMPO, and the menu INTERVIEWS: conducted by students to discuss its work. All the content produced on this website is available in various social media, such as, the YouTube channel (Jovem Cientista), the profile on Instagram (@jovemcientista.com.br) associated with a Facebook page (@jovemcientista.com.br), the profile on TikTok (@jovemcientista.com.br) and by Linkedin and Twiter in the editors' profile. In addition, the site provides a communication channel with the entire team. Since its creation, content has been developed in the nuclear area from basic concepts to applications of radiation in different areas, such as, the environment, dosimetry, and health, among others. The possibility of using ICT has been positive, helping to demystify and disseminate nuclear physics.

  • IPEN-DOC 29292

    ZAMBONI, C.B. ; STANOJEV, M. ; KOKA, A.C.S.S. ; GIOVANNI, D.N.S. ; REDÍGOLO, M.M. . Analysis of XX century gold-silver coins by X-ray fluorescence and neutron tomography. In: ENCONTRO DE PRIMAVERA DA SOCIEDADE BRASILEIRA DE FÍSICA, 2.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 45.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 42.; RENAFAE WORKSHOP, 26-29 de setembro, 2022, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: X-ray fluorescence (XRF) is a technique capable of analyzing chemical elements on metallic surfaces, providing fast, sensitive, and reliable results while neutron tomography (NT) allows to investigate its internal structure by three-dimensional images. Both techniques are powerful tools for non-destructive analysis of artistic and historical objects. In this study, we explored the combined use of these techniques to investigate a set of Brazilian gold-silver coins dating from the early 20th century (1913-1938). This set of coins was select due to the lack of data related to their composition and origin. These data provide information to museologists for better cataloging / registration of fundamental information. Moreover, this information is vital for collectors and marchands in authentication processes. The X-Ray Fluorescence analysis was performed using X-Ray Spectrometer with gold (Au) and silver (Ag) targets. The excitation conditions were optimized in 30 kV and 5 μA and counting time of 200 s. A NT facility is installed at the beam-hole (BH-14) of the 4.5 MW pool-type IEA-R1 nuclear research reactor at IPEN (SP, Brazil). It consists of a 6LiF (ZnS) scintillator screen, a glass-based plane mirror, a video camera (16bit, 1024 x1024 pixels, cooled CCD) and a collimator to reduce the neutron beam size in the BH-14. The experimental conditions established were: 8 x106 ns-1 cm-2 (neutron flux), irradiation time/image of 1s, spatial resolution of 263 ± 35 μ and time tomography of 400s. The three-dimensional images were treated using dedicated software (OctopusV8.0 and VG studio Max2.2). The combined results bring information of elemental composition and 3D images highlight the conservation state of the pieces, being of great aid to conservators and museologists.

  • IPEN-DOC 29203

    PIERETTI, EURICO F.; CORREA, OLANDIR V. ; NEVES, MAURICIO M. das ; ANTUNES, RENATO A.. Fatigue resistance of a laser-treated biomaterial. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: One of the main characteristics required for biomaterials is its surface finish. The same metallic implant may have a varied surface finish; from polishing, for regions where there is mobility, to high roughness to ensure greater adhesion. The laser beam has been used for surface treatments such as hardening and marking, for example. Another application of the laser beam is the texturing of surfaces. The objective of this work was to characterize the fatigue resistance, in the tensile-traction regime, of samples of ISO 5832-1 austenitic stainless steel, treated by an Yb doped optical fiber laser beam. For comparison purposes, samples without laser marking treatment were also evaluated. The markings consisted of the recording of the surfaces of the specimens by generating parallel and juxtaposed characters. The results indicated an increase in the average roughness in the laser-marked areas, which become regions of stress concentration, favoring the appearance and propagation of cracks that trigger fatigue failure. The samples treated by laser showed lower fatigue resistance compared to the untreated ones.

  • IPEN-DOC 29202

    PIERETTI, EURICO F.; BONANI, EDUARDO G. ; ANTUNES, RENATO A.; NEVES, MAURICIO M. das . Wear of SLM AISI 316L stainless steel for biomaterials application. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The laser techniques usage on the biomaterial’s field includes welding, engraving, cutting and texturing. The present study evaluated the influence of laser texturing process on the tribological behavior of AISI 316L austenitic stainless steel (SS) on the friction coefficient and wear volume in ball-cratering wear tests. The laser texturing process was carried out with a nanosecond optical fiber ytterbium laser at four different pulse frequencies. Advanced selective laser melting (SLM) techniques allow the production of pieces with the most varied sizes, shapes and complex geometries. For comparison reasons, pristine surfaces were also evaluated. The sample’s surfaces finishing was analyzed by laser confocal microscopy. The wear tests were carried out during 10 min, solid spheres of 52-100 chrome steel, with 2 mm in diameter, were used as counter-bodies. The results indicated that the tribological behavior is influenced by the laser additive manufacturing (AM) process parameters used for this biomaterial, and the wear rate is dependent of the normal force and the roughness of each specimen.

  • IPEN-DOC 29201

    TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F.; ROSERO, WILMMER A.A. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; NOGUEIRA, THUANY C. ; ANGELOCCI, LUCAS V. ; ROSTELATO, MARIA E.C.M. . Development of a new material to encapsulate phosphorus-32 for use in brachytherapy. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The term cancer refers to a set of malignant diseases that have in common the disordered growth of mutated cells, which can invade adjacent tissues or distant organs[1]. In 2020, cancer of the central nervous system (CNS) represented 1.6% of all new malignant tumor cases in the world, and about 2.5% of all new cancer deaths[2]. A promising radioactive source for use in intracavitary brachytherapy is phosphorus-32. This source has been prominent as a minimally invasive treatment for craniopharyngiomas and in the treatment of metastatic bone diseases in general[3]. To encapsulate phosphorus-32 and make it a viable radioactive source for use in medicine, some methods have emerged. In this work, we are developing a fabric soaked in industrial latex for this purpose, as this source comes in the form of orthophosphoric acid in aqueous solution and as industrial latex is soluble in water. Tests carried out so far show that the material supports orthophosphoric acid while is still malleable, which is essential for treating spinal cancer.

  • IPEN-DOC 29200

    KOMATSU, LUIZ G.H. ; COSTA, FERNANDA A.T. da ; FERREIRA, BARBARA V. ; CAJADO, GIUSEPPE M. ; LUGAO, ADEMAR B. ; PARRA, DUCLERC F. . Film of the blend of HMSPP/SEBS with TiO2@Ag for biocide activity against Candida albicans and Aspergillus niger for medical applications. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: One of the most promising ways to overcome the biocide infections on medical materials is the use of metal oxides. The nanoparticle of Titanium Dioxide doped with Silver (TiO2@Ag) is one of the most promising materials due to the biocide properties against the Candida albicansand Aspergillus niger. With these observations, in the present work, the nanoparticles of TiO2@Ag were synthesized by adapting the method of Turkevich [1] and in the sequence, they were incorporated in the polymeric blend of High Melt Strength Polypropylene (HMSPP)[1]/Styrene-Ethylene/Butadiene-Styrene (SEBS). Following that incorporation, it was obtained thin films of 0,3 and 1 %wt concentrations (based in previous results[1]) for characterization tests. The films were evaluated by Biocide tests following the JIS 2801-10 norm with Candidaalbicans ATCC 10231 and Aspergillus niger ATCC 6275, X-ray Diffraction (DRX), Raman Spectroscopy. On biocide tests were observed biocide activity of the film with 0,3wt% of TiO2@Ag showed, in the logarithmic reduction of the bacteria, count upward the standard normalized by the norm (≥2), value of 3,24 of logarithmic reduction. In the Raman Spectroscopy and DRX were confirmed the presence of the Ag on the TiO2: DRX the peak of θ = 23,81 ° was attributed to TiO2@Ag on the film and on Raman Spectroscopy the peak of 1048 cm-1refered to the NO3 -residual of the the silver nitrate, other peaks at 1334 and 1459 cm-1of the silver indicating the presence in the film [2].

  • IPEN-DOC 29199

    VENANCIO, EVERALDO C.; MORAES, EIDER H. de; ALVARENGA, KLEBER da S.M.; SILVA, LUIS M.G. da ; LEMOS, HUGO G. de. Synthesis and characterization of conducting polymers/graphene oxide derivatives and conducting polymers/carbon black nanocomposites. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The interest on the properties of conducting polymers (CP)/graphene oxide (GO), CP/reduced graphene oxide (rGO), and CP/carbon black (CB) has been related to the possibility of the different applications of these materials, such as in sensors, energy storage and conversion and biological applications [1-3]. Our research group has been studying the properties of these materials for application in different areas. Our main goal is to obtain and to control the synthesis of GO and rGO and combine these materials with CP, as well as to study the effect of different CP:CB composition ratios on its properties. These CP/OG and CP/rGO materials are versatile platforms for application in water filtering and purification systems, protection of metals against corrosion, and energy storage and conversion, which includes solar cells and supercapacitors.

  • IPEN-DOC 29198

    THYSSEN, VIVIAN V.; VILELA, VANESSA B. ; FONSECA, FABIO C. . Lanthanum-ceria modified with calcium for oxidative coupling of methane. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Ethylene (C2H4) is considered a fundamental component of the chemical industry, it is a raw material widely used to produce plastics, solvents, fertilizers, etc. Currently, the main route to obtain C2H4is the steam cracking of naphtha from crude oil, a well-established technology that is hardly challenged. The search for more sustainable alternatives must be ongoing, and among the alternative, we can mention the use of natural gas. The oxidative coupling of methane (OCM), the main component of natural gas, is a compelling direct pathway of methane (CH4) conversion into higher added value hydrocarbons, such as C2(C2H6and C2H4). [1] La2Ce2O7catalyst performs well in OCM due to its high thermal stability, suitable alkaline sites, and selective mobile oxygen sites. Doping La2Ce2O7with Ca increases the alkalinity, which can considerably increase C2selectivity in the OCM. We have explored a scalable method of combustion synthesis, a high-throughput technique that provides favorable porous microstructures for stable catalysts at high temperatures. The obtained La2Ce2- xCaxO7powders (0 ≤ x ≤ 0.5) SEM images evidenced a microstructure composed of porous sponge-like agglomerated particles with an irregular shape, expected from the type of synthesis. The materials showed crystalline structures of disordered fluorite and C-type, indicated by both XRD and Raman analysis. Raman spectroscopy data also evidenced the presence of surface oxygen vacancies on materials, which benefited the OCM reaction. The catalytic tests showed us that the addition of Ca increased the C2selectivity by 10%, at 750oC and a CH4:O2molar ratio of 6:1. [2].

  • IPEN-DOC 29197

    LOBO, RAQUEL de M. ; CASTAGNET, MARIANO ; MIRANDA, CARLOS A. de J. ; LIMA, JOSE R. de ; FALOPPA, ALTAIR A. ; MATTAR NETO, MIGUEL ; PEREIRA, LETICIA dos S. ; ANDRADE, ARNALDO H.P. de . The use of miniaturized samples to determine mechanical properties of materials. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The caracterization of irradiated materials through the SPT (Small Punch Test) technique uses miniaturized samples, with 8 mm in diameter and 0.5 mm in thickness, which has fixed edges, pressed by a sphere that has a diameter d=2.5 mm[1], tested in convencional mechanical testing machines, with the aid of a device developed for their achivement. This tecnique developed for nuclear industry can be used where conventional methods do not apply because it is considered an almost “non-destructive” method[2]due to the small sample volume. In this work two different devices were developed to perform tests at room and sub-zero temperature. The SPT tests will be carried out on standardized nuclear materials unirradiated (ferritic and stainless steels) for later correlation with conventional mechanical tests. Several mechanical properties will be obtained such as yield stress, tensile strength and fracture properties of the materials such as its toughness.

  • IPEN-DOC 29196

    PATRICIO, NICOLE B. ; CARDOSO, JULIANO C. ; LANFREDI, ALEXANDRE J. de C.; ESCOTE, MARCIA T.; SANTIAGO, ELISABETE I. . Evaluation of bifunctional CeO2/ZrO2 catalysts in methane electrooxidation. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Methane (CH4) is the main component of natural gas (70 to 90%), the fossil fuel, whose consumption has grown the most in the world. The International Energy Outlook 2019 projects that global consumption of natural gas will increase by 40% from 2018 to 2050, reaching 200 quadrillion btu [1]. Electro-oxidation of this compound can occur at low temperatures via direct method and the increase in the conversion rate to methanol can be achieved with the development of new efficient catalysts. In this work, the synthesis of CeO2/ZrO2-based bifunctional electrocatalysts was evaluated using the hydrothermal process assisted by microwave, varying the proportions in the ratios of 1:2, 2:1 and 1:6 Ce/Zr, respectively. Such mixtures are used as starting precursors to form mixed metal oxides and solid solutions followed of heat treatment at 200ºC for 30 minutes for phase formation, called mixed oxides (CexZryO2) and solid solutions (CeO2/ZrO2). The electro-oxidation of methane under potentials of 1.1V and 1.6V vs. Ag/AgCl led to the majority formation of methanol, ethanol, and acetone as the main products of this conversion in sodium carbonate medium as an electrolyte. However, these conversions are more pronounced from the variation of Ce/Zr ratios to produce both alcohols with 2.4% and 4.2% efficiency for CeO2/ZrO2(1:1), respectively, while CeO2/ZrO2(1:2) generates only methanol with a higher efficiency of 6.9%. Thus, under optimized conditions, it was possible to observe that ceria and zirconia oxides can efficiently promote the conversion of methane to other commercially valuable products using suitable oxidation potentials and, therefore, be a promising alternative for this reaction.

  • IPEN-DOC 29195

    SANTOS, BIANCA P.S.; KODAMA, YASKO ; SANTIAGO, ELISABETE I. . Synthesis and characterization of fluoropolymer membrane using RIG and reversible addition-fragmentation- chain-transfer (RAFT) method for fuel cell application. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Anion exchange fuel cells (AEMFC) have attracted widespread attention in the last years and are considered one of the most promising environmentally friendly power generations. An auspicious way to produce well-controlled structures for applications as anion exchange membrane is using the radiation-induced grafting method (RIG) with RAFT agents [1]. RAFT consists of a reversible addition fragmentation chain transfer of free radicals and allows the control over polymeric molecular weight and copolymer topology and other properties. Ethylene tetrafluoroethylene (ETFE) is a type of fluoropolymer that can be applied in AEM due to its lightweight, excellent chemical and thermodynamic stability, and greater resistance to radiation ageing [2]. In this study, we investigated the beneficial outcomes of performing the ETFE-AEM synthesis in a fully controlled manner by RAFT polymerization using RIG. The influence of RAFT agent on physical (mechanical behavior, dimension), chemical (such as IEC), thermal properties (TGA and DSC) were investigated in detail for future and evaluated in AEMFCs. ETFE-grafting-Vinylbenzyl chloride (VBC) using RAFT agent controlled grafting degree of membrane and improved mechanical properties compared to conventional method of grafting.

  • IPEN-DOC 29194

    COELHO, JESSICA F. ; SANTIAGO, ELISABETE I. ; LOPES, THIAGO. Development of Fe-N-C electrocatalysts for oxygen reduction reaction for application in electrochemical systems. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The increase in energy demand and the decrease in the supply of fossil fuels has made fuel cell technology evolve a lot in recent years. These devices have potential in various applications such as portable power, stationary electricity generation, vehicular propulsion and power plants. Despite the high efficiency and environmental benefits associated with their use, fuel cells still lack optimizations to make them commercially viable. These problems have been associated with the lack of catalysts that would allow these devices to compete with existing technologies. Therefore, Fe-N-C non-precious metal electrocatalysts work well for cathodic applications, especially in AEMFC given the favorable kinetics of the oxygen reduction reaction (ORR) in alkaline medium [1, 2]. In this work, we explore the synthesis of Fe-N-C electrocatalysts from a polymeric precursor formed by the oxidative polymerization of 1,5-diaminonaphthalene together with the transition metal salt that undergoes pyrolysis to obtain a catalyst with high surface area and conductivity. The activity results obtained by RDE in alkaline medium showed that the half-wave potential for the Fe-N-C electrocatalyst in ORR is only ≈60 mV more negative than the commercial platinum catalyst. In addition, tests in AEMFC with Fe-N-C used in the cathode reached a peak power density of 679 mW cm-2, revealing a good result for ORR and showing promise for this application [3].

  • IPEN-DOC 29193

    SPARVOLI, MARINA; CHUBACI, JOSE F.D.; MORAIS, FERNANDO G.; JORGE, FABIO de O.; MATTA, JOSE ; LANDULFO, EDUARDO . Characterization of cellulose biofilm obtained from production of Kombucha. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Kombucha is fermentation of green tea with sugar that results in a probiotic drink and cellulose biofilm, in addition to alcohol, acetic acid and carbon dioxide. The mechanism is the same as that of Jun, however the association of yeasts and bacteria is slightly different and moved by sugar, instead of honey. It is possible that the name “Kombucha” originates from Japanese words “kombu” which means seaweed and “cha” that stands for tea. Jun, on the other hand, has an origin shrouded in mysteries, and may come from Tibet or even be a modern invention, according to Sandor Katz explains in his book “art of fermentation”. In this study, research was carried out on the sugar type influence on the growth of cellulose matrix, or biofilm, obtained from the fermentation process of Kombucha. The material was obtained from fermentation process of green tea with sugar. Various parameters can be modified in the production of cellulose, such as temperature, type of tea, type of sugar, process time, among others. In this work, for each process, first, it was necessary to obtain the initial fermented solution: for 4 days the fermentation took place in a mixture of green tea, water, 10% of green already fermented in a previous process and a type of sugar (mascavo, melaço, demerara, crystal and white sugar). Fermentation took place in an environment with a controlled temperature of 25 °C and 60% humidity. In a second step, 40 ml of fermented Kombucha (with no more sugar added) was transferred to each of the petri dishes, containing a microscope slide, to ferment for another 4 days in order to produce a film of cellulose that was analyzed by XRF (X-ray fluorescence), UV-Vis spectroscopy and microscope, in addition to having its density obtained by the Archimedes method. The films produced were pressed and dried in halogen lamp. Fifteen samples were produced. The fermented liquid from the second phase in the petri dishes was characterized with respect to pH, BRIX and density.

  • IPEN-DOC 29192

    JANUARIO, ELIANE R. ; VAZ, JORGE M. ; SPINACE, ESTEVAM V. . Au/Ga2O3 photocatalysts for methane conversion coupling with hydrogen evolution from water. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Methane is a major constituent of natural gases and is an important source of carbon and hydrogen for the chemical industry. However, methane is one of the most stable molecule and high reaction temperatures are required to transform methane into more valuable and useful chemicals [1]. The use of solar energy and a photocatalyst would be an ideal method to convert methane in milder conditions.[1] Recently, it was reported the direct combination of hydrogen evolution from water and the methane conversion in a photocatalytic system over Pt/TiO2.[2] In this study, we investigated the use of β-Ga2O3loaded with different amounts of Au nanoparticles (0.1–1.0%) as photocatalysts that were prepared by impregnation of HAuCl4 solution onto a commercial β-Ga2O3 and reduction at 200 °C under hydrogen flow. The photocatalysts were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy, Transmission Electron Microscopy (TEM), and Raman Spectroscopy. The photocatalytic reactions were performed on a commercial Ace photocatalytic reactor equipped with a mercury lamp (450W, UV/A/B/C). A steady stream of methane gas was bubbled into water containing the photocatalyst in suspension and the products were identified by GC-MS and quantified by GC-FID/TCD using calibration curves. The principal products formed were C2H6, CO2, and H2 with minor quantities of C2H4, C3H8, C4H10, and CO. The best performance was observed for the photocatalyst prepared with 0.1% of Au that produced 129 μmol.gcat -1h-1of C2H6 and 10,062 μmol.gcat -1h-1of H2.

  • IPEN-DOC 29191

    PIERETTI, EURICO F.; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; NEVES, MAURICIO M. das ; ANTUNES, RENATO A.; PILLIS, MARINA F. . Tribological evaluation of anodized aluminum applied to biomaterials. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Biomaterials surfaces need to be adequate to the function they perform; for this reason, the importance of studying surface finish increases as design requirements grow, regarding geometry and precision requirements in biomedical devices. These biomaterials are subject to several types of premature failure, such as wear, fatigue, micro movements, particle detachment and degradation, which may generate the need for new interventions. Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. Due to good biocompatibility, regular arrangement of nanopores, ease of control of nanopore diameter, large specific surface area, low cost, good thermal stability and, absence of toxicity, anodic aluminum oxide has been studied. The geometric arrangement of nanopores makes it possible to use alumina as a mold for the synthesis of several nanostructures that have many advantages in advanced application areas due to their unique chemical, physical, mechanical and optical properties. In the present work, the tribological behavior of samples of aluminum alloy AA6061 anodized in oxalic acid solution (C2H2O4) and sulfuric acid (H2SO4) was evaluated. Prior to the anodization stage, the samples were electrolytically polished in a solution of perchloric acid and ethanol. For comparison reasons, pristine surfaces were also evaluated. The sample's surfaces finishing was analyzed by laser confocal microscopy. Atomic force microscopy was also used to evaluate samples roughness and topography. The wear tests were carried out during 10 min, solid spheres of 52-100 chrome steel, with 2 mm in diameter, were used as counter-bodies. The results indicated that the tribological behavior is influenced by the anodized layer process parameters, and the wear rate is dependent of the normal force and the roughness of each sample.

  • IPEN-DOC 29190

    PIERETTI, EURICO F.; CORREA, OLANDIR V. ; NEVES, MAURICIO M. das ; ANTUNES, RENATO A.; PILLIS, MARINA F. . Electrochemical evaluation of anodized aluminum applied to biomaterials. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Anodic aluminum oxide has attracted a lot of interest due to the regular arrangement of nanopores, ease of control of the nanopores diameter, large specific surface area, low cost, good thermal stability, absence of toxicity and biocompatibility. Due to these characteristics, anodic aluminum oxide structures have been used in applications such as filtration processes, biosensors, oxygen sensors, catalysis and photocatalysis. In addition, the geometric arrangement of nanopores makes it possible to use alumina as a mold for the synthesis of various nanostructures, such as nanopores, nanotubes, nanorods and nanowires that have many advantages in advanced application areas due to their unique chemical, physical, mechanical and optical properties. In the present work, the localized corrosion resistance of samples of aluminum alloy AA6061 anodized in oxalic acid solution (C2H2O4) and sulfuric acid (H2SO4) was evaluated by electrochemical techniques. Prior to the anodization stage, the samples were electrolytically polished in a solution of perchloric acid and ethanol. The results indicated superior corrosion resistance in the anodized samples in both conditions. Therefore, it is necessary to constantly advance research on the use of nanoporous anodic alumina coatings on biomaterials surfaces.

  • IPEN-DOC 29189

    BUGARIN, ALINE de F.S. ; VIVEIROS, BARBARA V.G. de ; TERADA, MAYSA; SILVA, LEANDRO S. da; GUILHERME, LUIS H.; NEVES, MAURICIO D.M. das ; COSTA, ISOLDA . Study of the corrosion resistance of duplex and lean duplex steels welded by the gas tungsten arc welding double fusion (GTAW-DF) applied in the construction of tanks. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Duplex stainless steels has great technological importance due to the combination of high mechanical strength, high toughness and excellent corrosion resistance. New methods of joining these materials have been investigated and updated, with better cost-benefit. In this work, joints welded by the TIG process with root pass by the double-fusion method (GTAW-DF), typically applied in the construction of tanks for the citrus juice and biotechnology industry were investigated. The welding process of steels changes in its microstructures forming of deleterious precipitates which decrease the corrosion resistance. Thus, the aim of this work was to evaluate and compare the corrosion resistance after welding by the GTAW-DF process of similar joints of lean duplex 2101 steel and dissimilar joints of 2205 and 2304 steels, duplex and lean duplex respectively, both used in the citrus juice industry. Samples were made using optimized welding parameters under corrosion resistance criteria. Microstructural characterization was performed by metallographic etching and observation by optical microscopy (OM) and by scanning electron microscopy (SEM). Mechanical properties were evaluated by microhardness test. Corrosion resistance was evaluated by electrochemical tests by the double loop electrochemical potentiokinetic reactivation test (DL-EPR) and potentiodynamic polarization test. The results showed that the welding process caused microstructural changes in the materials, and that after welding the most susceptible regions to corrosion were in the fusion line and in the thermally affected zone. When analyzing the two welding conditions, it was observed that the welded samples with higher heat input showed lower tendencies to intergranular corrosion.

  • IPEN-DOC 29188

    RIBEIRO, GLEICY de L.X. ; CASTRO, RENATO S. de; PORTO, JOAQUIM F.B.; SILVA, LEANDRO S. da; GABRIEL, ANDRE H.G.; SANTOS, LUIS U. dos; TERADA, MAYSA; OLIVEIRA, RENE ; COUTO, ANTONIO A. . Phases identification and quantification of AISI 316L produced by laser powder bed fusion. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The additive manufacturing process by powder bed fusion (L-PBF) consists of the incidence of a high power laser on the material that promotes the fusion and later the solidification layer by layer creating the 3D from a computational model. The main advantage of this process is the fabrication of objects with complex geometries. AISI 316L steel is widely used in the additive manufacturing process because it has good weldability. Due to good corrosion resistance, it is used as a biomaterial for the manufacture of implants. The high temperatures achieved in the L-PBF process can cause phase transformation, in which part of the austenitic phase (FCC) is transformed into the martensitic phase (CCC), affecting its corrosion resistance. The purpose of this work is the crystallographic characterization by X-ray diffraction of AISI 316L in powder form and after additive manufacturing by L-PBF. The powder used in the process was gas atomized, with an average particle diameter of 50 micrometers. The parts were manufactured using the Yb laser (wavelength 1060 nm) with a scan speed of 1200 mm/s and power of 147 W, 184 W and 211 W. The powder was characterized by SEM for morphological analysis and by X-ray diffraction for phase identification and quantification. The manufactured samples were characterized by SEM and MO, to observe the microstructure, and by X-ray diffraction to identify and quantify the phases present. After the additive manufacturing process, with the increase in laser power, it was possible to observe, in addition to the austenite, the presence of the ferritic phase.

  • IPEN-DOC 29187

    QUEIROZ, FERNANDA M.; RIBEIRO, GLEICY de L.X. ; CASTRO, RENATO S. de; SANTOS, ROGERIO G. dos; PORTO, JOAQUIM F.B.; SILVA, LEANDRO S. da; VIEIRA, ALEXANDRE ; SANTOS, LUIS U. dos; TERADA, MAYSA ; ROSSI, WAGNER de ; COSTA, ISOLDA . Study of the effect of nanosecond laser texturing on the corrosion behavior of Ti6Al4V and Ti6Al4V parts produced by powder bed fusion. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Biomedical industry demands surfaces that facilitate osteointegration, especially in implants. Currently, this functional surface is obtained by coating the metallic implant with ceramic materials, such as hydroxyapatite, or with polymeric materials. However, these layers can suffer from detachment, residual stresses, and cracks during the process, favoring implant corrosion. Laser texturing is a surface structuring process that can improve osteointegration by generating functional hydrophilic surfaces. An alternative for the manufacture of components used as biomaterials can be additive manufacturing, followed by laser texturing. The 3D manufacturing process allows obtaining parts with complex geometry, weight reduction, and customized products that can serve the dental and biomedical sector. Combining metallic additive manufacturing with laser texturing would be an alternative in obtaining parts with functional hydrophilic surfaces, which improves osteointegration. In both cases, a careful study of the corrosion behavior of the surfaces obtained is necessary, since the evolution of this phenomenon can influence the osteointegration of the implant, causing the release of metal ions in the body and even the rejection of the component. This study compared the corrosion behavior of laser texturing Ti6Al4V components with components manufactured using laser power bed fusion of the same alloy followed by laser texturing. The Ti6Al4V components by laser powder bed melting were obtained by varying the scanning speed and power using a Yb laser. For laser texturing of the surfaces, a fiber optic laser of Yb was used. The corrosion behavior of the surfaces was evaluated by electrochemical impedance spectroscopy and characterized by SEM. The wettability was determined by the sessile drop method. The results showed the differences in the corrosion behavior of the surfaces produced by the different methods, in the hydrophilic character and microstructure.

  • IPEN-DOC 29186

    PARRA, DUCLERC F. . Effect of silver nanoparticles on the stability of epoxy resin Bis GMA composite. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: Many authors have been trying to develop materials with antimicrobial activity and apply them to different segments of Dentistry. Biocompatibility and significant antimicrobial activity encourage the use of silver nanoparticles in biomaterials. The aim of this study was to develop an experimental resin composite based on Bis-GMA and TEGDMA filled with silver nanoparticles at a concentration of 100ppm in order to verify its antibacterial activity againstStreptococcus mutans. Synthesized silver nanoparticles were characterized by UV-vis (Visible Ultraviolet Spectroscopy), DLS (Dynamic Light Scattering), TEM (Transmission Electron Microscopy), microbiological test, and XRD (X-ray Diffraction) techniques. Final experimental composites were characterized by TGA (Thermogravimetric Analysis), FTIR (Fourier Transform Infrared Spectroscopy), RAMAN (Raman Spectroscopy), and a direct contact antibacterial test. Results showed nanoparticles with approximately 5 nm and crystalline orientation. Silver nanoparticles interfere in the polymerization process affecting the thermal stability of the material.

  • IPEN-DOC 29185

    RODRIGUES, ALEX A. ; CORTEZ, MARLOS; MASCARENHAS, NEIDE F. ; REIS, ISMARIA S.; LIMA, MAYELLE M.P. ; GODOI, ELIANA L. ; VIEIRA, DANIEL P. . Análise histórica das atividades do biotério Nanci do Nascimento (IPEN): prospecção para inovação e otimização dos principios dos 3 R’s. In: EXPOBIOTERIOS HYBRID, September 29-30, 2022, Medellín, Colombia. Abstract... 2022.

  • IPEN-DOC 29180

    RIBEIRO JUNIOR, IBERE S. ; ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. ; DRESCHER, ADAM; LANDSBERGER, SHELDON. On the use of coincidence INAA for selenium determination. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 44., 9-11 de novembro, 2021, Online. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2021.

    Abstract: Instrumental Neutron Activation Analysis (INAA) is a widely used technique applied on the determination of several elements in different matrices. Selenium is one of the elements that can be studied by INAA and its determination is usually performed using one, or both, 136:01 and 264:66 keV transitions from 75Se radioisotope. Se determination by INAA is a case that requires special attention, mainly in virtue of three issues: (i) spectral interferences may occur due to intense gamma rays from 181Hf (136 keV) and 182Ta (264 keV); (ii) in samples with high levels of K and Na, the increased background levels due to Compton effect lead to enlargement of the detection limit; (iii) high concentration of P or any other intense high-energy beta emitter can severely impact the detection below 200{300 keV due to bremsstrahlung radiation. A possible solution for these issues is the use of gamma-gamma coincidence INAA (CINAA), as the 136 and 264 keV transitions are part of a strong gamma-gamma cascade. In this work coincidence measurements of the decay of 75Se were performed to compare the results for Se obtained by conventional INAA and CINAA in biological and geological Certi ed Reference Materials (CRMs). The results show that the use of coincidence can drastically reduce the net/gross ratio, which implies in a reduction of the detection limit for 75Se; furthermore, the results of Se concentration obtained using both methodologies are in agreement with the certi ed values, and both techniques provided accurate results.

  • IPEN-DOC 29179

    FELIX DOS SANTOS, R.; SERRA FILHO, L.A.; MUNHOZ, M.G.; BREGANT, M.; MORALLES, M. ; SOUZA, F.A. . Performance and optimization of a GEM-based neutron detector using a parameterized fast simulator. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 44., 9-11 de novembro, 2021, Online. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2021.

    Abstract: Neutrons can be detected indirectly through a nuclear reaction where the products are ionizing radiation. Due to the shortage of 3He, most commonly used element for such measurements, several studies are searching alternatives, where the Gas Electron Multiplier (GEM) detector using a layer of 10B as a neutron converter is a very promising option. The GEM detectors are a type of Micro-Pattern Gaseous Detectors (MPGD), widely used in particle tracking systems, as the Time Projection Chamber of the ALICE experiment in the LHC-CERN, and proposed for many other applications, including neutron detection. A common strategy to simulate this kind of detector is based on two frameworks: Geant4 and Garfield++. The first one provides the simulation of the nuclear interaction between neutrons and the 10B layer, while the second allows the simulation of the interaction of the reaction products with the detector gas leading to the ionization and excitation of the gas molecules. Given the high ionizing power of this nuclear reaction products, a full simulation is very time consuming and must be optimized to become viable. We developed a fast simulator by means of parameterization strategy based on these two frameworks that allowed us to generate enough data to study an optimized version of this detector aiming for a better position resolution.

  • IPEN-DOC 29178

    GENEZINI, FREDERICO A. ; ZAHN, GUILHERME S. ; MORALLES, MAURICIO . Opportunities for using the IEA-R1 reactor in nuclear applications. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 44., 9-11 de novembro, 2021, Online. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2021.

    Abstract: The IEA-R1 nuclear research reactor is a pool-type reactor that has been in operation at the Institute for Energy and Nuclear Research, IPEN, at the University of São Paulo-USP main campus since the 1950s. The IEA-R1 reactor, which is Brazil's largest source of neutrons, can be used in a variety of nuclear applications when operating at the maximum power currently allowed, 5 MW. Irradiations in the reactor core aimed at producing radioactive sources and neutron beam studies can both be performed and generate competitive data. Upgrades to the reactor's equipments and a plan to extend the operational cycle to nine days in a row are ongoing. These actions should attract additional customers and create new opportunities for the IEA-R1 in nuclear applications.

  • IPEN-DOC 29177

    SERRA FILHO, L.A.; FELIX DOS SANTOS, R.; SOUZA, G.G.A. de; BREGANT, M.; MUNHOZ, M.G.; SOUZA, F.A. ; MORALLES, M. ; NATAL DA LUZ, H.. Position sensitive GEM-based thermal neutron detector prototype with 10B4C converter. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 44., 9-11 de novembro, 2021, Online. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2021.

    Abstract: In the last decade, several efforts have been made by the scientific community to find alternatives to 3He, the most effective gas used for thermal neutron detection, which is virtually extinct [1]. Common alternatives make use of isotopes such 157Gd, 10B, and 6Li, due to their high neutron capture cross-section [2]. We present in this work our detector prototype: a 10 cm x 10 cm double GEM stack with an aluminum cathode, coated with a 2:2 μm thick 10B4C layer deposited by the European Spallation Source (ESS). The detector operates under ArCO2 (90/10) open flow at atmospheric pressure. The neutrons are detected through the gas ionization charges created by the outcomes of the 10B(n;α)7Li capture reaction. These charges are collected in a 256x256 strip readout plane produced by CERN, connected to resistive chains we designed for this project and produced in the local industry. We tested the prototype in the IPEN IEA-R1 nuclear reactor with a 1:4Å monochromatic neutron beam. We will report experimental measurements showing that the prototype presented high stability, position sensitivity with spatial resolution better than 3mm (obtained by 2 methods), detection efficiency of 2:66(30)%, and good agreement with simulated results regarding the energy spectrum of the neutron capture products. We will finally discuss further methods to be adopted for enhancing detection efficiency.

  • IPEN-DOC 29176

    BUENO, L.K. ; VILLANI, D. ; RODRIGUES JUNIOR, O. ; POTIENS, M.P.A. . Study on depth of measurement and volume variation of nuclides used in nuclear medicine for “in situ” ionization chamber characterization: an experimental and Monte Carlo comparison. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 385-386.

  • IPEN-DOC 29175

    ALMEIDA JUNIOR, J.N. ; POTIENS, M.P.A. ; RODRIGUES JUNIOR, O. . Desenvolvimento de um sistema de filtração adicional semi-automatizado para a implantação de novas qualidades de feixe de raios-X utilizados em radiodiagnóstico. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 370-371.

  • IPEN-DOC 29174

    ONUDIBIA, M.E.; SILVA, P.S.C. ; ESSIETT, A.A.; ZAHN, G.S. ; GENEZINI, F.A. . Radioactivity concentration and radiological effect of soil from Umuahia Abia State, Nigeria. In: INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 254-255.

  • IPEN-DOC 29173

    AYLLON, R.M. ; FURLAN, M.R.; EL HAJJ, T.M.; SILVA, P.S.C. . Th-232 radiological aspects of carbonate niobium mining waste use as agricultural amendment. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 252-253.

  • IPEN-DOC 29172

    NISTI, M.B. ; MADUAR, M.F. ; CAVALCANTE, F. ; SAUEIA, C.H.R. . Estimated absorbed dose rate in the non-human biota in different environmental scenarios. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 217-218.

  • IPEN-DOC 29171

    DIAS, F.S. ; POTIENS, M.P.A. . Verificação da confiabilidade de câmaras de ionização de placas paralelas para feixes de raios X de baixa energia. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 185-186.

  • IPEN-DOC 29170

    SCAPIN, M.A. ; TESSARI, M.C.Z. ; COTRIM, M.E.B. . Espectrometria de fluorescência de raios X: uma técnica robusta para analisar resíduos e rejeitos radioativos. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 174-176.

  • IPEN-DOC 29169

    DAMATTO, S.R. ; RODRIGUES, C.E.C. . Trace elements determined by INAA in a sediment core dated by Pb-210 method from Laguna de Peña, Uruguay. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 160-161.

  • IPEN-DOC 29168

    OTERO, A.G.L. ; POTIENS, A.J. ; MARUMO, J.T. . A desktop application for automatic gamma spectroscopy analysis with deep learning. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 143-144.

  • IPEN-DOC 29167

    TAVARES, P.V.S. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Uso da técnica de tomografia computadorizada óptica para dosimetria química com solução Fricke xilenol gel. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 139-140.

  • IPEN-DOC 29166

    ALMEIDA NETO, J.O. ; DAMATTO, S.R. ; MADUAR, M.F. ; LEONARDO, L. ; TEIXEIRA, L.F. ; DOMINGOS, R.M.. Study of 7Be activity concentration in rainfall as a function of sampling height. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 135-136.

  • IPEN-DOC 29165

    NASCIMENTO, G.G. ; SILVA, C.R.; CAMPOS, V.P. ; CAMPOS, L.L. . Assessment of energy and angular dependence of LiF:Mg,Ti dosimeters irradiated in the quality Hp(0.07). In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 123-124.

  • IPEN-DOC 29164

    ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; ALMEIDA, M.R. ; TODO, A.S. ; RODRIGUES JUNIOR, O. . X-ray experimental set-up for in-vivo nail test. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 121-122.

  • IPEN-DOC 29163

    MARTINS, E.W. ; POTIENS, M.P.A. . Metodologia de calibração “in situ” de Ativímetros para 111In e 123I. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 102-103.

  • IPEN-DOC 29162

    ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; KOKA, A.C. ; ALMEIDA, M.R. ; MEDEIROS, I.M.M.A. ; LEAO, A.R. . Propostas alternativas para o conhecimento e uso da Energia Nuclear. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 86-87.

  • IPEN-DOC 29161

    KOKA, A.C.S.S. ; ZAMBONI, C.B. . Minuto Nuclear. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 84-85.

  • IPEN-DOC 29160

    SANTOS, A.G.M. ; ENGLER, C.; SUZART, K.F. ; RODRIGUES, P.S. . Brazilian Nuclear Sector: an analysis of the sociocultural profile of women working in nuclear research and technological development institutions. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 51-52.

  • IPEN-DOC 29159

    TESSARI-ZAMPIERI, M.C. ; SANTIAGO, A.F.; COTRIM, M.E.B. . Materialidade do tema proteção radiológica em programas de sustentabilidade ASG (Ambiental, Social e Governança). In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 48-49.

    Abstract: A materialidade é uma metodologia eficaz para identificar e estimar passíveis Ambiental, Social e Governança (ASG). As organizações utilizam a matriz de materialidade apenas para cumprir os requisitos do GRI, podendo gerar matriz incompleta e inconsistente. Os resultados de acordo, de acordo com o GRI para o parâmetro “radiação” encontra-se diversos temas de sustentabilidade onde as questões de proteção radiológica devem ser abordadas, como saúde e segurança do trabalho, avaliação ambiental de fornecedores, conformidade ambiental, comunidades locais, resíduos e abordagem de gestão. A elaboração de uma matriz de materialidade para as organizações que manipulam elementos radiológicos, com a devida identificação das partes interessadas necessita de métodos previamente definidos para que possam ser repetidos e revisados periodicamente, e desta forma, possibilitando demonstrar a evolução das preocupações com a sustentabilidade e seu alinhamento com as necessidades estratégias das organizações.

  • IPEN-DOC 29158

    SUZUKI, F.F. ; NORMANTON, K.A.F. ; RODRIGUES, D.L. ; GERULIS, E. . Resultados do sistema de averiguação de ocorrências no estado de São Paulo no período de 2011 a 2021. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 31-32.

  • IPEN-DOC 29157

    LEONARDO, L. ; DAMATTO, S.R. ; MADUAR, M.F. . Natural radioactivity in oilseeds commercialized in the city of São Paulo, Brazil. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 25-26.

  • IPEN-DOC 29156

    PAVAO, S. ; CONTI, T.N. . A performance humana e a segurança em instalações nucleares: marcos regulatórios. In: LIMA, FERNANDO de A. (Org.); DANTAS, BERNARDO M. (Org.); LEVY, DENISE (Org.) INTERNATIONAL JOINT CONFERENCE RADIO, 6th; CONGRESSO INTERNACIONAL DE RADIOPROTEÇÃO INDUSTRIAL, 9th; CONGRESSO DE PROTEÇÃO CONTRA AS RADIAÇÕES DOS PAÍSES DE LÍNGUA PORTUGUESA, 8th; CONGRESSO BRASILEIRO DE PROTEÇÃO RADIOLÓGICA, 7th; ENCONTRO NACIONAL DE MULHERES DO SETOR NUCLEAR, 1st, August 15-19, 2022, Poços de Caldas, MG. Abstract... 2022. p. 12-13.

  • IPEN-DOC 29151

    NASCIMENTO, GABRIEL G. do ; CAMPOS, VICENTE de P. de ; RODRIGUES, LETICIA L.C. . Avaliação da resposta TL em função da dose de dosímetros de LiF:Mg, Ti na grandeza Hp(0,07) utilizando o rod phantom. In: CONGRESSO BRASILEIRO DE FISICA MEDICA, 26th; CONGRESSO LATINO-AMERICANO DE FISICA MEDICA, 9th, June 8-11, 2022, Fortaleza, CE. Abstract... 2022.

    Abstract: Os dosímetros são utilizados para quantificar a dose que o indivíduo ocupacionalmente exposto recebe durante seu período de atividades. O dosímetro de extremidade tem a finalidade de quantificar a dose em uma região específica do corpo, as mãos. Para um dispositivo ser utilizado como dosímetro, ele deve passar por alguns testes de calibração/caracterização, entre eles, o teste de resposta em função da dose, onde o dosímetro é irradiado com diferentes doses no intervalo de interesse recomendado, preferencialmente, deverá apresentar um padrão linear de resposta em função das doses utilizadas. O Hp(0,07) é uma grandeza operacional estabelecida para monitoração individual externa, sendo 0,07 mm a profundidade adotada. Neste trabalho as irradiações foram realizadas na grandeza Hp(0,07) utilizando um rod phantom, com o objetivo de avaliar a resposta TL em função da dose, aplicando os dosímetros de LiF:Mg, Ti.

  • IPEN-DOC 29150

    MAZER, AMANDA C. ; YORIYAZ, HELIO . Avaliação de registro de imagem realizado com e sem pontos de referência extraídos através da técnica SIFT. In: CONGRESSO BRASILEIRO DE FISICA MEDICA, 26th; CONGRESSO LATINO-AMERICANO DE FISICA MEDICA, 9th, June 8-11, 2022, Fortaleza, CE. Abstract... 2022.

    Abstract: Em Radioterapia Guiada por Imagem (IGRT), é comum a aquisição de diversas imagens de um paciente e, por consequência, a realização de registro de imagem para a comparação entre elas. Devido a isso, é fundamental que sejam realizados tanto um bom registro quanto um bom controle da qualidade (CQ) do registro. O objetivo deste trabalho é avaliar um registro de imagem quando realizado com e sem pontos de referência. Para isso, imagens de Tomografia Computadorizada (TC) de um paciente da radioterapia foram utilizadas para realizar registros rígido e elástico, com e sem pontos de referência. A técnica Scale Invariant Feature Transform (SIFT) foi utilizada para desenvolver um algoritmo para a extração semi-automática de pontos-chave estáveis das imagens, tanto para os registros quanto para a avaliação de tais registros. Através dos valores de erro médio, erro máximo e Informação Mútua (IM) encontrados, foi possível verificar um melhor alinhamento das imagens quando realizado o registro partindo inicialmente dos pontos de referência extraídos, em comparação com o alinhamento realizado sem esses pontos de referência. A SIFT mostrou ser uma ótima ferramenta para realizar ambas as tarefas e, quando possível, o profissional da clínica deve realizar um bom CQ quantitativo de registro, considerando pontos de referência distribuídos pelas imagens.

  • IPEN-DOC 29149

    FERREIRA, HORTENCIA de J. ; RIGO, MARIA E.Z. ; NOGUEIRA, THUANY C. ; ROSTELATO, MARIA E.C.M. . Radioactive iodine-125 seed intraoperative localization for impalpable breast lesions conservative surgery: case series analysis. In: CONGRESSO BRASILEIRO DE FISICA MEDICA, 26th; CONGRESSO LATINO-AMERICANO DE FISICA MEDICA, 9th, June 8-11, 2022, Fortaleza, CE. Abstract... 2022.

    Abstract: The radioactive seed localization (RSL) technique is used for breast cancer conserving surgeries to guide the surgeon in tumor identification and excision. The aim of this study was to perform a systematic analysis of case series about the surgical efficiency, safety and logistic outcomes of the services that performed the RSL program incorporation in their institution. The systematically research was performed in PubMed, EMBASE and Web of Science looking for case series. Was identified 24 case series, the population consist in 7177 women with non-palpable breast lesions, aged 19-92 years old, who underwent conservative surgery or biopsy excisional. The results about positive surgical margins, intraoperative re-excision, reoperation, recurrence, sentinel node biopsy failure, complications and time interval between localization and surgery shows a high rate of surgical efficiency, associated to low rates of intervention complications. Keywords: breast conservative surgery; radio guided surgery; radioactive seed localization.

  • IPEN-DOC 29147

    GASPARIAN, PATRICIA B.R. ; MALTHEZ, ANNA L.M.C.; TORQUATO, MICHELE; CAMPOS, LETICIA L. . Radiosurgery dosimetry using OSL film made with CaSO4:Eu: a feasibility study. In: EUROPEAN CONGRESS ON RADIATION PROTECTION, 6th, May 30 - June 3, 2022, Budapest, Hungary. Abstract... Budapest, Hungary: Akadémiai Kiadó, 2022. p. 169-169.

    Abstract: Recent studies demonstrated that optically stimulated luminescence (OSL) systems allow the evaluation of doses for 2D mapping in a relatively fast and simple way and results show submillimeter resolution (Ahmed et al., 2017; Jahn et al., 2013). The two most advanced-stage studies with satisfactory application in 2D dose mapping are based on commercial prototype detectors (Al2O3:C and BeO). Some OSL materials have been evaluated in research laboratories for use in 1D and 2D dose distribution assessments and there is no common sense on the best OSL material for each application (Yukihara and Kron, 2020). This work presents, for the first time, an optically stimulated luminescence (OSL) film made with CaSO4:Eu particles embedded in a silicone elastomer matrix. The OSL film was produced using a low-cost and relatively simple methodology. This film is reusable and the signal can be satisfactorily bleached using blue LEDs. The main dosimetric properties were evaluated using TL/OSL Risoe reader with blue stimulation and Hoya U-340 filter. Investigation shows repeatability within 5% when measuring with the same film sample. Regarding the OSL film homogeneity, nearly 15% sensitivity change was observed within the 5 x 5 cm2 produced film. Additionally, the dose response curve shows linearity from 5 to 25 Gy. Further studies are necessary to understand and minimize the influence of OSL signal fading, which seems as high as 70% in the first week and then is stable. Nevertheless, a 3 x 3 cm2 OSL film was successfully used to map dose distribution in radiosurgery (6 MeV photon beam). This work demonstrates the feasibility of 2D dosimetry using low-cost and reusable OSL films based on CaSO4:Eu.

  • IPEN-DOC 28992

    ZEZELL, DENISE . FTIR hyperspectral imaging for label-free histopathology. In: INTERNATIONAL SYMPOSIUM AND INTERNATIONAL SCHOOL FOR YOUNG SCIENTISTS ON “PHYSICS, ENGINEERING AND TECHNOLOGIES FOR BIOMEDICINE”, 5th, November 21-25, 2020, Moscow, Russia. Abstract... Moscow, Russia: MEPhI, 2020. p. 65-65.

    Abstract: FTIR hyperspectral pathology imaging of thin tissue slice samples are used to monitor the collagen during the healing process when evalu-ating burned skin, treated or not with femtosecond laser, in the diagnose and molecular differentiation between thyroid and goiter, skin squamous cell carcinoma, as well as for breast cancer cell subtypes.

  • IPEN-DOC 28991

    ZEZELL, DENISE . Infrared thermography and thermographic analysis in laser dentistry and orthopedics. In: INTERNATIONAL SYMPOSIUM AND INTERNATIONAL SCHOOL FOR YOUNG SCIENTISTS ON "PHYSICS, ENGINEERING AND TECHNOLOGIES FOR BIOMEDICINE", 5th, November 21-25, 2020, Moscow, Russia. Abstract... Moscow, Russia: MEPhI, 2020. p. 64-64.

    Abstract: Infrared thermography imaging has been used to diagnose a number of diseases where superficial temperature can indicate the presence of inflammation in underlying tissues or where blood flow is increased or decreased due to a clinical abnormality. Thermographic analysis can be used to determine the safe laser irradiation conditions when developing a new clinical procedure. In this talk, the basis of Infrared Thermogra-phy will be presented, and examples of measurements during laser treatment of myofascial back pain syndrome, temporomandibular disor-ders, dental cavity preparation with laser, caries prevention with lasers, laser in endodontics, periodontics, prosthodontics and implants will be presented.

  • IPEN-DOC 28990

    BARBOSA, T.S.; RIZO, E.C.S.; RIBEIRO, M.S. . Desenvolvimento e caracterização de biomembranas a base de quitosana para aplicações na área médica: resultados preliminares / Development and characterization of chitosan-based biomembranes for applications in the medical area: preliminary results. In: CONGRESSO DE FÍSICA APLICADO À MEDICINA, 7., 28 de setembro - 1 de outubro, 2011, Botucatu, SP. Resumo... 2011.

    Abstract: Introdução Nas ultimas décadas, o desenvolvimento de novas pesquisas em biomateriais tem permitido avanços significativos nas áreas de Ciências da Vida englobando várias frentes de estudo como: engenharia de tecido, pesquisa em células-tronco, sistema de transporte de medicamentos, terapia gênica, entre outros. A respeito disso tem se estudado com bastante atenção o uso de quitosana. Quitosana é obtida pelo processo de desacetilação da quitina presente no exoesqueleto de crustáceos e na parede celular de fungos e insetos. O seu uso, tem se intensificado devido suas propriedades intrisecas como ser biodegradável, não tóxica, bacteriostática, fungistático e anti-tumoral. Outra característica pertinente a esse biopolimero é as diferentes formas que podem adquirir, dependendo do interesse do estudo, sendo elas em forma de biomembrana, em forma esférica, entre outras. Também devido os seus três tipos de grupos de reação funcional, presente em sua estrutura, pode-se facilmente combinar com outros compostos orgânicos de interesse como: alginato, ácido hialurônico, fosfato de cálcio, polimetilmetacrilato (PMMA), acido poli-L-láctico (PLLA) e fatores de grupo de potencial aplicação. Pesquisas envolvendo aplicações em medicina regenerativa possuem necessidade indiscutível, pois auxiliam diretamente no tratamento de lesões superficiais, na reconstrução de órgãos e na produção de curativos entre outros possíveis usos. Particularmente, essa investigação baseia-se no desenvolvimento de metodologia para produção de biomembrana artificial para aplicação em medicina. Metodologia O objetivo do trabalho foi estabelecer condições ótimas para o emprego das biomembranas como auxiliar na reparação tecidual, seja no processo de regeneração ou cicatrização. Foram preparadas soluções com 2 g de quitosana são dissolvidas em 100 ml de ácido acético (1%) e homogeneizadas por 24 horas. As biomembranas foram colocadas em placa de Petri para secagem no ambiente. Na sequencia a solução foi filtrada e mantida com pH 4. A neutralização foi efetiva com solução de hidróxido de sódio (NaOH) para obter um pH entre de 6 e 7. Na Fig. 1 apresenta-se a biomembrana obtida e utilizada nas aplicações. A aplicação da biomembrana foi realizada em grupo de ratos com lesões projetadas artificialmente. Discussão Foram realizadas avaliações do aspecto clínico da lesão em período de 2 a 7 dias, como indicador inicial do processo de reparação. Para avaliação morfológica utilizou-se microscopia óptica e de varredura. Particularmente a técnica de Microscopia de Força Atômica (MFA) tem sido utilizada para obter detalhes da estrutura, elasticidade e interações, ainda permitindo a imagem de alta resolução dos tecidos biológicos ao natural, e como principal vantagem nenhum tipo de preparação é requerido para a análise por esta técnica. Nesse estudo avaliamos a qualidade da biomembrana obtida por MFA.

  • IPEN-DOC 26679

    PEREIRA, MARIA da C.C. ; CARDENAS, JOSE P.N. ; MADI FILHO, TUFIC . The growth and scintillation characteristics of lithium doped CsI crystals. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 212-212.

    Abstract: Inorganic scintillators play an important role in the detection and spectroscopy of gamma and X-rays, as well as in neutrons and charged particles. For a variety of applications, new inorganic scintillation materials are being studied. New scintillation detector applications arise continuously and the interest in the introduction of new fast scintillators becomes relevant. Scintillation crystals based on cesium iodide (CsI) have relatively low hygroscope, easy handling and low cost, features that favor their use as radiation detectors. In this work, lithium doped CsI crystals were grown using the vertical Bridgman technique. In this technique, the charge is maintained at high temperature for 10 h to for the material melting and complete reaction. The temperature gradient 21° C/cm and 1 mm/h descending velocity are chosen as technique parameters. After growth is finished, the furnace is cooled at a rate of 20° C/h to room temperature. The concentration of the lithium doping element (Li) studied was 10-3 M. Analyses were carried out to evaluate the scintillator developed concerning two responses: a) to the gamma radiation, in the energy range of 350 keV to 1330 keV and b) to neutron from AmBe source, with energy range of 1MeV to 12 MeV. T.S. Korolevaa et al [1] describe in their paper about new scintillation materials, for registration of gamma-rays, X-rays, neutrons and neutrinos. One of these materials is 6Li. Lithium can capture neutrons without gamma-ray emission and, thus, reducing the back-ground. The neutron detection reaction is 6Li(n,a)3H with a thermal neutron cross section that 940 barns. In this paper we investigated the feasibility of the CsI:Li crystal as a gamma ray and neutron detector which can be used for monitoring, due to the fact that in our work environment we have two nuclear research reactors, calibration systems and radioisotope production.

    Palavras-Chave: cesium iodides; crystals; doped materials; lithium; molecular crystals; phosphors

  • IPEN-DOC 26660

    ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. ; JAE-SON, KWANG; LEE, JUN S.; COSTA, OSVALDO L. ; MOURA, JOÃO A. ; FEHER, ANSELMO ; MOURA, EDUARDO S. ; SOUZA, CARLA D. ; MATTOS, FABIO R. ; PELEIAS JUNIOR, FERNANDO S. ; KARAM JUNIOR, DIB. Production of iodine-125 in nuclear reactors: advantages and disadvantages of production in batch or continuous production in cryogenic system. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 149-150.

    Abstract: Cancer is one of the worst illnesses in the world and one of the major causes of death in Brazil [1,2]. For this reason, the Nuclear Energy National Commission (CNEN) started a project to produce some medical radioisotopes to treat cancer. One of the main products is the iodine-125 seeds [3]. This iodine seed can be used to treat several kinds of cancer: prostate, lung, eye, brain. As Brazil will construct a new reactor to produce radioisotopes, it is necessary define how the iodine-125 production will carry out [4,5]. The main reaction of this production is the irradiation of the enriched xenon-124 in gaseous form. Xe-124 changed to Iodine-125 by neutron capture following in two decays: Xe-124 (n, y) —• Xe-125m (57s) —• I- 125 or Xe-124 (n, y) —• Xe-125 (19.9 h) —• 1-125. However the production in reactors is the most common technique used, there is one disadvantage to use it: the production of iodine- 126 after several hours of irradiation. Iodine-126 has a half life of 13.1 days and it has some usefulness emitters for medical uses. Iodine-126 is considered a contamination [6]. For all these reasons, the IPEN/CNEN-SP research group decided for two techniques of production: in batch or continuous system. The production in batch consists in a sealed capsule that is placed in the reactor core for around 64 hours. In this type of production, some iodine-126 is produced and a certain quantity of Xe-124 is not activated. Normally, it needs to wait around 5 to 7 iodine-126 half-lives to guarantee the decrease of the activity of the contamination. This time will make Iodine-125 with only 50% till 34% of the initial production. The second technique is the continuous production using a cryogenic system. This technique consists in two capsules: one inside the reactor core and the second one out of the neutron flux. These two capsules will be linked with two cryogenic pumps to guarantee that all iodine-125 produced in the core will be take off the reactor core. The great disadvantage of this technique is the using of two positions in the core of the reactor. Brazil will have only one radioisotope reactor producing. And like there is a huge quantity of materials to be produced, it is not a guarantee the position in the reactor for this production. Besides of that the seeds production in Brazil is only 3000 per month, which demands around 3.5 Ci per month. The batch production produces a low quantity per reactor cycle of iodine-125, but this low quantity can be more than that [2,3].

    Palavras-Chave: cryogenics; iodine 125; isotope production; isotope production reactors; nuclear medicine; radiopharmaceuticals

  • IPEN-DOC 26564

    SOUZA, CARLA D. ; VICENTE, ROBERTO ; ROSTELATO, MARIA E.C.M. ; ZEITUNI, CARLOS A. ; MOURA, JOÃO A. ; MOURA, EDUARDO S. ; MATTOS, FABIO R. ; FEHER, ANSELMO ; COSTA, OSVALDO L. da ; VIANNA, ESTANISLAU B. ; CARVALHO, LAERCIO de ; KARAN JUNIOR, DIB. Preliminary proposal for radioactive liquid waste management in a brachytherapy sources production laboratory. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 48-48.

    Abstract: Malignant tumors are responsible for a high death rate in the entire world population (1). Prostate cancer is the third most common among men, after skin and lung. The treatment using permanent Iodine-125 seed are too costly, preventing the use in large scale (1) (2). A multidisciplinary team was formed to develop a source of Iodine-125 and assemble a national facility for local production. For the production correct implementation, a plan for radiological protection that has the management of radioactive waste fully specified are necessary. This work has developed an initial liquid waste management proposal. The most important Iodine-125 liquid waste is generated in the first phase of the process, radioactive material fixation. The initial proposal is that the waste is deposited in a 20 L container (2 years to fill). The final activity of this container is 4.93 x 1011 Bq. According to the discharge limits presented in the brazilian's regulation CNEN - NE - 605 - Management of radioactive wastes in radioactive facilities (3) this waste could safely be release to the environment in 3.97 years. In the other hand,if a minimization waste policy will be implemented, the production could becomes more efficient and cheaper. Waste storage at 25 L containers and changing some production parameters results in 3 years waste to be eliminated in 3.94 years. This new plan will optimize the materials used and diminished the waste generation facilitating the management, contributing to a cheaper product.

    Palavras-Chave: iodine 125; isotope production; liquid wastes; radioactive waste management; radioactive waste processing

  • IPEN-DOC 26563

    CARDOSO, J.R. ; MOURA, E. ; SOMESSARI, E.S.R. ; SILVEIRA, C.G. ; PAES, H.A. ; SOUZA, C.A. ; MANZOLI, J.E. ; GERALDO, A.B.C. . Mechanical evaluation of PVC films modified by electron beam irradiation. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 71-71.

    Abstract: The polyvinyl chloride (PVC) is a technological and low cost polymer. Although this polymer is weather resistant, it presents high sensitivity to high energy irradiation because of the weakness of carbon-chloride bond face to carbon-carbon and carbon-hydrogen bonds [1]. Upon exposure to high energy irradiation, some carbon-chloride bonds are broken to give rise radicals like chlorine and organic chloride that are initiators of two concurrent processes: degradation and crosslinking. The degradation process on PVC is macroscopically observed by discoloration effects, where the material tends to darken or to turn yellow, mainly at a typical sterilization dose of 25 kGy [2]; this process yields hydrogen chloride as a byproduct, it is autocatalytic and it continues after irradiation exposure. By other way, the crosslinking leads to an improvement in thermal resistance and mechanical properties. The aim of this work is to evaluate the mechanical properties of PVC irradiated by electron beam to verify the degradation process. Also, mechanical properties are investigated on styrene grafted PVC by electron beam irradiation using mutual and pre-irradiation methods to verify the mechanical resistance changes of obtained product if grafting process is applied from non-irradiated and from pre-irradiated substrates. The PVC commercial film samples with 210 jam thickness were cut into a dumbbell-shape (gauge length: 25 mm, width: 4.10 mm, area: 0.86 mm2). The grafting media was styrene /butanol-1 mixture in several monomer concentrations (from 10% to 100%). The samples were irradiated on a Job 188 Dynamitron® Electron Beam Accelerator with 1.5 MeV energy. All irradiation procedures were performed in atmosphere air and the irradiation conditions comprised doses from 10 kGy to 100 kGy and dose rates of 2.2 kGy/s and 22.4 kGy/s. The styrene grafted samples were analyzed by gravimetry to determinate the grafting yield; the final values have been averaged from a series of three measurements. The Mid-ATR-FTIR was the spectrophotometer technique used for qualitative/semi-quantitative analysis of grafted samples. The Young's module and tensile strength of pre-irradiated and grafted PVC samples at both methods were measured at a Lloyd LXR tensile tester at a crosshead speed of 10.00 mm/min. We observed the decrease of Young's module and tensile strength with the increase of absorbed dose at pre-irradiated PVC samples, that it indicates degradation process. These mechanical parameters results are discussed to styrene grafted PVC samples.

    Palavras-Chave: doses; electron beams; external irradiation; modifications; polymerization; polymers; pvc

  • IPEN-DOC 26562

    ROSTELATO, M.E.C.M. ; MATTOS, F.R. ; ZEITUNI, C.A. ; SOUZA, C.D. ; MOURA, J.A. ; MOURA, E.S. ; FEHER, A. ; COSTA, O.L. ; PELEIAS JUNIOR, F.S. ; MARQUES, J.R.O. ; BELFORT NETO, R.. Iridium-192 seed development for ophthalmic cancer treatment. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 144-144.

    Abstract: Considered a public health problem in Brazil, cancer is the second leading cause of mortality by disease, representing 13.2% of all deaths in the country [1]. Ophthalmic brachytherapy involves inserting an acrylic plate with radioactive material in the eyes of a patient for treatment of ocular tumors. This work is a partnership between Escola Paulista de Medicina - UNIFESP and the Instituto de Pesquisas Energéticas e Nucleares - IPEN for development and implementation of a cheaper therapeutic treatment for ophthalmic cancer with a iridium-192 source, to attend a greater number of patients. Iridium-192 is produced in nuclear reactor. It has a half-life of 74.2 days and decays by beta emission with average energy of 370 keV.[2,3]. The seed will be a platinum-iridium alloy core (80/20), encapsulated in a titanium tube [4]. This project will be divided into the following steps: characterization of materials by FRX (X-ray fluorescence) e EDS (Energy Dispersive Spectroscopy); iridium irradiation in the nuclear reactor IEA-R1; sealing of iridium-192 seed; leakage tests of iridium-192 source in accordance with standard ISO-9978 (radiation protection- Sealed radioactive sources- Leakage test methods) [5]; metallographic tests and measure the activity of the source. The evaluation for use in the ophthalmic treatment of cancer will be made later.

    Palavras-Chave: external irradiation; eyes; iridium 192; neoplasms; radiotherapy; seeds; therapy

  • IPEN-DOC 26556

    COSTA, OSVALDO L. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. ; MOURA, JOÃO A. ; FEHER, ANSELMO ; MOURA, EDUARDO S. ; SOUZA, CARLA D. ; SOMESSARI, SAMIR L. . Improvements in the quality control of iridium-192 wire used in brachytherapy. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 126-126.

    Abstract: Brachytherapy is a method used in the treatment of cancerous tumors by ionizing radiation produced by sources introduced into the tumor area, this method seeks a more direct attack to the tumor, thereby maximizing the radiation dose to diseased tissue while minimizing the dose to healthy tissues (1). One of the radionuclides used in brachytherapy is iridium-192. The Radiation Technology Center (CTR) of the Nuclear and Energy Research Institute (IPEN) has produced commercially, since 1998, iridium-192 wires used in low dose rate (LDR) brachytherapy (2). To produce this radionuclide, firstly a iridium-platinum wire is irradiated in the nuclear reactor IEA-R1 for 30 hours with a neutron flux of 5 x 1013 ncm-2s-1, the wire is left to decay by 30 days to remove the main contaminants and then goes through a quality control before being sent to the hospital. In this quality control is checked the radiation homogeneity along each centimeter of the wire (3). To implement this procedure is used a device consisting of an ionization chamber surrounded by a lead shield with a small 1 cm wide slit, linked to the ionization chamber is a voltage source and a Keithley 617 electrometer, 2 minutes is the range used to measure the charge by the electrometer. The iridium wire is considered in accordance when there is no variation greater than 5% between the average measures and the maximum and minimum values. However, due to design features of the measurement system, the wire may appear to the detector through the slit in larger sizes than the ideal, improperly influencing the final quality control. This paper calculates the difference in size of these variations in profile and their influence on the final count, it compares the actual values obtained and describes the improvements made in quality control procedures that provided more accurate measurement data, analyzes the results and suggests changes in devices aimed at further improving the quality control of iridium-192 wires produced at IPEN and used in hospitals in Brazil.

    Palavras-Chave: brachytherapy; external irradiation; iridium 192; quality control; sealed sources

  • IPEN-DOC 26555

    FROSE, C.A.P. ; MOURA, E. ; YAMAGUISHI, R.B. ; SOMESSARI, E.S.R. ; SILVEIRA, C.G. ; LEME, E. ; GERALDO, A.B.C. ; MANZOLI, J.E. . Effect of ionizing irradiation on tilapia (Oreochromis niloticus) skin. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 62-62.

    Abstract: The culture of tropical tilapia (Oreochomis niloticus), as a non-native freshwater fish specie in Brazil, have had importance in the last decade due its fast growing, fast reproduction characteristics, high tolerance of climate variations in our country and high disease resistance. The high demand of whole fish or fillets is related to its good taste. Althought, its skin, that represents from 4.5 % to14 % of fish weight, is a byproduct that is generally discared or sold at low cost to feed mills. The general animal skin composition comprises protein, water, minerals and fatty matter where the relative portions of these materials depends of upon animal specie, age, breed, feeding and other animal habits. The putrecible raw animal skins can be chemically and physically treated to make it in non-putrecible stabilized material; it results in a soft and flexible polymeric material. The chemical process to obtain this material generally involves a crosslinking of carboxyl groups or amino groups of skin proteins and the chemical reactive specie [1]. Also, physical process as UV irradiation have been successfully employed to crosslink collagenous biomaterials and thus, improved some mechanical characteristics [2]. The goal of this work was to study the tilapia skins exposed to ionizing irradiation from electron beams. The raw skins and the chemically degreased skins were the studied materials. The tensile strenght and elongation at break were the mechanical parameters evaluated. The optical microscopy was used to evaluate some histological characteristics in irradiated and non-irradiated samples. Also, the polymeric product obtained when skins are treated with oxidizing ions were used to compare some results. The tilapia raw skins were kindly available by APTA, a governmental agribusiness technological agency. These skins were scales free, slighted and frosted. The skins were irradiated in atmosphere air on a Job 188 Dynamitron® Electron Beam Accelerator with 1.5 MeV energy under comprised doses of 20 kGy and 40 kGy and dose rates of 2.2 kGy/s and 7.4 kGy/s. The mechanical parameters were measured at a Lloyd LXR tensile tester at a crosshead speed of 10.00 mm/min. Irradiated samples shows high integrity and high tensile strength in comparison to the polymeric product obtained by oxidizing ions reaction. These results are discussed.

    Palavras-Chave: electron beams; external irradiation; fish products; ionizing radiations; radiation doses; radiolysis

  • IPEN-DOC 26498

    MARCATO, L.A. ; HAMADA, M.M. ; MESQUITA, C.H. . Biokinetics and radiation dosimetry for [4-(14)C]-cholesterol in humans. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 164-164.

    Abstract: Medical and clinical researches utilize radiolabelled cholesterol to obtain information about the physiology of cholesterol and of its several substrates (biliary acids, hormones and vitamins) in the body. The radiotracers constitute a simple and accurate tool for metabolic studies; however, the scientific community has shown certain reservations concerning the use of radioisotopes. Probably, the apprehension is result of the question about the deleterious radiation effects. Although the studies that utilize radioisotopes are approved by strict ethic committees, most of them do not mention the radiometric doses at which the human subjects are exposed during these studies. The International Commission on Radiological Protection (ICRP) provides a generic carbon model (GCM) to calculate the effective dose of compounds labeled with 14C, first described on ICRP publication 30. The effective dose coefficients for most compounds appear to be greatly overestimated by the GCM in comparison with those generated by more realistic models [1]. The GCM cannot be applied to the interpretation of bioassay data with any degree of confidence [1]. The purpose of the present study is to improve the generic biokinetic model [2] for use in the assessment of the internal dose received by human subjects who were administered labelled cholesterol either orally or intravenously. This model was used with the ANACOMP software to estimate the radiometric doses with the MIRD techniques. To validate the model, the simulated profile curves were compared with the profile curves described on the literature (Kruskal-Wallis test, P=0.4232). The model reproduced the intestinal absorption of cholesterol and the excretion of cholesterol in feces and urine. The estimated effective dose coefficient calculated for the reference man described on ICRP publication 23 was 1.35x10-11 SvBq-1. The organs that received the highest equivalent dose were the lower large intestine (1.03x10-10 GyBq-1), upper large intestine (3.74x10-11 GyBq-1) and small intestine (1.58x10-11GyBq-1). The effective dose coefficient calculated by the proposed dosimetric model was approximately forty-three times lower than that which is calculated by the ICRP generic model (5.8x10-10 SvBq-1) for ingested 14C that assumes complete absorption to blood.

    Palavras-Chave: cholesterol; carbon 14; dosimetry; biochemical reaction kinetics; labelled compounds; radiation doses

  • IPEN-DOC 26392

    SANTOS, D.R.A. ; GARCIA, V.S.G. ; VILARRUBIA, A.C.S. ; BORRELY, S.I. . Acute toxicity assessment of fluoxetine hydrochloride (Prozac®) when submitted to electron beam irradiation. In: DUDALA, JOANNA (Ed.); STEGOWSKI, ZDZISLAW (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENT AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... Krakow, Poland: Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 2011. p. 58-58.

    Abstract: The large-scale production of medicinal products is directly related to the presence of pharmaceutical drugs in sewage and water. The continuous input of medicines and its residues into the environment especially by sewage and wastewater generates an increasing need of new methods for its treatment and suitable control. The fluoxetine hydrochloride (FH), also known as Prozac®, is an active ingredient used in the treatment of depressive and anxiety disorders [1]. The present study focused on applying the ionizing radiation in order to reduce the acute toxicity of the FH drug solution, under its manipulated formula, to aquatic organisms. Hyalella azteca and Daphnia similis were the organisms used in the biological assays applied for the toxicity studies. It was used a Dynamitron electron beam accelerator and its energy was fixed at 1,4MeV for 5kGy and 10kGy doses [2]. For the calculation of the effective concentration (EC50) it was used the statistic program Trimmed Spearman - Karber. The average values for acute toxicity of FH were 0.59mg.L-1 (EC5 096h) for Hyalella azteca and of 1,44mg.L-1 (EC5 048h) for Daphnia similis. After irradiation of the FH aqueous solution, the following EC50 average values were obtained: 7.81mg.L-1 (5kGy) and 7.97mg.L-1 (10kGy) for Hyalella azteca; 8,46mg.L-1 (5kGy ) and 7.31mg.L-1 (10kGy ) for Daphnia similis. The obtained results revealed the FH as a very toxic compound. These results are confirmed by the EU - Directive 93/67/EEC (Commission of the European Communities) [3]. A significant reduction of the acute effects was obtained when 5kGy and 10kGy were applied.

    Palavras-Chave: biological wastes; drugs; electron beams; external irradiation; liquid wastes; nonradioactive wastes; toxicity; waste processing

  • IPEN-DOC 25745

    RABELO, J.S. ; PEREIRA, T.M. ; MAZZOCCHI, V.L. ; VALERIO, M.E.G.; ZEZELL, D.M. . Nanostructured synthetic hydroxyapatite and dental enamel heated e irradiated by Er,Cr:YSGG characterized by FTIR and XRD. In: INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, 11th; ENCONTRO SBPMat, 8., September 20-25, 2009, Rio de Janeiro, RJ. Abstract... Rio de Janeiro, RJ: Sociedade Brasileira de Pesquisa em Materiais - SBPMat, 2009.

    Abstract: The study evaluate the physical changes and/or chemical that occurs in synthetic hydroxyapatite (HAP) and in enamel under action of thermal heating in the furnace or laser irradiation of Er,Cr:YSGG that may cause changes in its structure to make them more resistant to demineralization aiming the formation of dental caries.

    Palavras-Chave: apatites; caries; dentistry; fourier transform spectrometers; laser radiation; laser-radiation heating; lasers

  • IPEN-DOC 24769

    ROMANELLI, MARIA F. ; VILLAVICENCIO, ANNA L.C.H. . Utilization of DNA comet assay and half embryo test to identify irradiated lentil. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 169-169.

    Observação: Report Number IAEA-SM-366/228P

    Abstract: Legumes make an important contribution to human nutrition on a worldwide basis. Insect infestation cause extensive damage to stored grains. Over the last few decades some countries adopted food irradiation as a safe food process. Radiation's processing on foods improves hygienic quality and extends their shelf life. The use of radiation treatment to reduce the microbial population and thereby extend the shelf life in legumes has been reported in many papers. Irradiation has been shown to be an effective pest control method for these commodities and a good alternative to prohibited methyl bromide. Radiation disinfestation can facilitate trade in foods that often harbor insect pests of quarantine importance. Although the wholesomeness of irradiated food is no longer a question there is a need for irradiation control in the international trade of foods, in order to enhance the consumer confidence in the regulation. As a screening methods to identify irradiated lentils, processed by e-beam as a food treatment to disinfestation, the DNA Comet Assay and Half Embryo tests were performed. The methodologies used in this work are based upon biological changes that occur in Brazilian lentils. The samples were irradiated in an electron beam accelerator facility of Radiation Dynamics Inc., USA (E=1,5 MeV, l=25 mA). The irradiation doses were 0,7; 1,4 and 3,0 kGy at dry conditions. The thickness of samples was less than 0,5 cm. A sensitive technique to detect DNA fragmentation is the microgel electrophoresis of single cells or nuclei, also called 'comet assay'. Since the large molecule of DNA is an easy target for ionizing radiation, changes in DNA offer potential as a detection method. It is restricted to foods that have not been subjected to heat or other treatments, which also cause DNA fragmentation. Lentil samples were crushed with a mortar and pestle and was transferred to 3ml ice-cold PBS. This suspension was stirred for 5 minutes and filtered. 100μl cell suspension was mixed with 500μl of low-melting agarose (0,8% in PBS). 100μl of this mixture was spread on pre-coated slides. The slides were immersed in lysis buffer (0,045M TBE, pH 8.4, containing 2,5% SDS) for 15 minutes. Electrophoresis was carried out using the same TBE buffer, but devoid of SDS, at a potential of 2V/cm for 2 minutes. Silver staining was carried out for I hour following fixing. Duplicate measurements for each sample were carried out and 100 cells were counted for each dose level. The migration patterns of DNA was evaluated with a standard microscope. Germination tests were carried out in the irradiated and non-irradiated dry lentils, which allows observing characteristically variations on the shoots and roots. The half-embryo test is based on the inhibition of shooting in seeds or grains due to irradiation. It is characterized by its easy detection and sensitivity. The shoots and roots wore observed during 5 days of culturing period under specified conditions. The difference observed in this variety was analyzed only after irradiation treatment at room temperature. Irradiated half-embryo showed markedly reduced root grows and almost totally retarded shoot elongation. Differences between irradiated and non-irradiated half-embryo could be observed.

  • IPEN-DOC 24746

    KOSEKI, PAULA M. ; RELA, PAULO R. ; VILLAVICENCIO, ANNA L.C.H. . Chromatographic analysis of irradiated medicinal herbs: Rhamnus purshiana D.C. and Paulinia cupana Kunth. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 168-168.

    Observação: Report Number IAEA-SM-366/227P

    Abstract: Introduction: Nowadays the interest in phytotherapeutics is increasing; therefore the consumer attention to the medicinal active plants is growing. The rich Brazilian flora, represents more than 20% of the plant species know in the world as raw materials for pharmaceutical preparations. Since the last decade microbiological decontamination of medicinal herbs by irradiation has been carried out and presented in many scientific articles. The microbial contamination in these raw plant materials is the issue of several studies, which propose appropriate techniques for the reduction of micro-organisms. One of these techniques is radiation processing by gamma source industrial plants. Other is the utilisation of accelerators. In order to safeguard consumers, treatment by ionizing radiation is allowed now in Brazil to medicinal herbs and pharmaceutical products. The radiation process is known as safe for a large variety of products and applications as well as a effective in the reduction of pathogenic micro-organisms. The aim of our study is observe if flavonoids and alkaloids will be influenced by irradiation. Experimental: Samples - Local herbs companies in Sao Paulo, Brazil, provided dehydrated samples of Rhamnus purshiana D.C. and Paulinia cupana Kunth. Irradiation. The powdered samples were irradiated in on plastic package in a electron beam accelerator facility of Radiation Dynamics Inc., USA (E=1,5 MeV, l=25 mA, installed in IPEN Sao Paulo, Brazil. The irradiation doses were 10,20 and 30 kGy at room temperature. The thickness of samples was less than 0,5 cm. Sample analysis -flavonoids and alkaloids analysis was performed in a Thin Layer Chromatography according to Wagner (1995). Results and discussion: No alterations in the flavonoids and alkaloids, after irradiation treatment in that herbs was observed. Chromatographic analysis of the different extracts irradiated at increasing doses indicated that there were no great differences in the chemical constitution of the herbs. The extracts, presented no change in the color increasing the irradiation doses (results are similar in other herbs extracts) as showed in the absorption peaks. The samples showed similar curves, presenting no changes in the chemical compounds. Pharmacological activity of medicinal herbs has been found satisfactory after treatment by high doses radiation.

    Palavras-Chave: alkaloids; bacteria; biological radiation effects; flavones; herbs; herbs; microorganisms; radiation doses; sterilization; tannic acid

  • IPEN-DOC 24683

    OSSO JUNIOR, J.A. ; LANDINI, L. ; LION, L.F. ; MORAES, V. . Production of 57Co, 109Cd, 111In and 117mSn using CV-28 cyclotron at IPEN-CNEN/SP. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 53-54.

    Observação: Report Number IAEA-SM-366/119

    Abstract: Several radioisotopes produced in Cyclotrons have physical properties of decay suitable to be used as: radiopharmaceuticals, for in vivo Diagnosis images (with the techniques of SPET and PET, Single Photon Emission Tomography and Positron Emission Tomography, respectively) and for Therapy, in Nuclear Medicine; calibration sources of several instruments applied in the nuclear area and in Metrology; and as radioactive tracers of elements investigated in many fields, such as Chemistry, Physics and Biology. This work describes the production of four of these radioisotopes that are very important in these areas: 57Co, 109Cd, 111ln and 117mSn. They can be obtained using the CV-28 Cyclotron at IPEN, because it can accelerate proton beams with energies up to 24MeV and currents up to 20μA (external). 57Co (t1/2=271.3 d) decays by electron capture to 57Fe with the emission of γ-rays and one characteristic X-ray. It is widely used as calibration source of detectors such as: Ge(Li), Ge(HP), Nal(TI) and dose calibrators (well type detectors). Besides these applications, 57Co Flood Sources are used to test the response uniformity of gamma cameras, in Nuclear Medicine. 109Cd has a half-life of 462.6 d and decays by electron capture to 109Ag with the emission of one γ-ray and one characteristic X-ray. This radioisotope can be employed as calibration source of X-ray and γ-rays detectors; as a radioactive tracer of Cd, an environment pollutant and used in the EDXRF (Energy Dispersion X-Ray Fluorescence) technique. 57Co was produced through the irradiation of natNi. Thick target yields for 55Co, 56Co, 57Co, 58CO, 56Ni and 57Ni were measured and the mean values were 346.69kBq/μA.h (9.37μCi/μA.h), for the direct production of 57Co and 150.59kBq/μA.h (4.07μCi/μA.h), through the decay of 57Ni (11.31 days after EOB - End of Bombardment). A solution of 57CoCl2 was prepared, to fill a flood source for calibration of gamma camera, with activity of 222MBq (6mCi) of 57Co and impurity levels of 1.13 and 1.29% for 56Co and 58Co, respectively, at delivery time. In order to achieve these results, a chemical separation method was developed with a separation yield of 93% for 5'7Co and a negligible loss of Ni. A composite target of Ni and Ag was prepared and a chemical separation method proposed to allow the separation between the targets and the products of interest, 57Co and 109Cd. The yields obtained in the irradiation of the composite target were: 947.94kBq/μA.h (25.62μCi/μA.h) of 57Co - direct reaction, 259-00kBq/μA.h (7μCi/μA.h) of 57Co - indirect reaction (11.31 days after EOB) and 71.41kBq/μA.h (1.93μCi/μA.h) of 109Cd, which showed the efficiency of its use, as well as the chemical separation, with a yield of 80% for 57Co and 109Cd. 111ln (t1/2=67.5 h) has appropriate characteristics for Diagnosis in Nuclear Medicine due to its decay mode (100% by electron capture) and its adequate half-life to slow biological studies, that makes it one of radioisotopes of interest of Brazilian Physicians. It can also be used in angular correlation studies in Nuclear Physics. 111In was produced by the 112Cd(p,2n)111ln reaction, that has the highest yield. The Cd targets were prepared by electroplating of CdSO4 solution in copper and copper/nickel backings. After being irradiated, a chemical separation was performed by an acetic acid extraction method, with an overall recovery yield for 111ln higher than 95%. The level of the chemical impurities of Cd, Ni and Cu were bellow than the permissible values. 117mSn (t1/2=14 d) has suitable characteristics of decay to be used as a tracer of SnCl2 in the labeling of organic molecules with 99mTc and also in radiotherapeutical applications. It was prepared by the irradiation of natural tin through the nuclear reactions natSn(p,xn)117Sb→117mSn. The production thick target yield of 117mSnnn was 784.4kBq/μA.h (21.20μCi/μA.h) and with the proper decay time of its precursor, 117Sb, no radionuclidic impurities appeared in the final product. A chemical separation method was developed to separate first 117Sb from the irradiated Tin and then 117mSn from Sb with a good chemical yield. The quality control procedures showed the good quality of the final product, 117mSn.

    Palavras-Chave: cyclotrons; cobalt 57; cadmium 109; indium 111; tin 117; radioisotopes

  • IPEN-DOC 24481

    MAIORINO, J.R. ; PEREIRA, S.A. ; SANTOS, A. ; SILVA, A.T. . MEA - Modified Energy Amplifier proposal. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 19-19.

    Observação: Report Number IAEA-SM-366/101

    Abstract: Recently Rubbia et al proposed a conceptual design of an Accelerator Driven System, known as Energy Amplifier (EA), as an advanced innovative reactor which utilizes a spallation neutron source induced by protons, from a Cyclotron or Linac, in a subcritical array imbibed in liquid lead coolant. Besides of being breeder and waste burner, the conceptual design generates energy and allows the use of Thorium as fuel. This paper introduces some qualitative changes in the Rubbia's concept. More than one point of spallation is proposed in order to reduce the requirement of proton energy and current of the accelerator, and mainly to make a flatter power density distribution. The subcritical core, which in the Rubbia's concept is an hexagonal array of pins immersed in a liquid lead coolant, is replaced by a concept of a solid lead calandria with the fuel elements in channels cooled by Helium. This concept allows on line refueling or shuffling, and the utilization of a direct thermodynamic cycle (Brayton), which is more efficient than a vapor cycle. Although the calculations to demonstrate the feasibility of the MEA concept are underway and not yet finished, these ideas do not violate the basic physics of the EA, but reduces requirement in the accelerator complex, which is more realistic and economical in today accelerators technology. Finally, the utilization of He as coolant, compared with liquid Pb, is more realistic since the gas cooled reactors technology is well established and more efficient from the thermodynamic view, allowing simplification and the utilization in high temperature process, like hydrogen generation.

    Palavras-Chave: accelerator breeders; comparative evaluations; cyclotrons; helium cooled reactors; linear accelerators; liquid metal cooled reactors; proton beams; proton beams

  • IPEN-DOC 24340

    SEGURA PINO, E. ; LIMA, L.F.C.P. . Glass transition temperature determination on cross-linked polyethylene by dynamic mechanical analysis. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 105-106.

    Observação: Report Number IAEA-SM-366/147

    Abstract: The Glass Transition Temperature, Tg, was determined on electron beam cross-linked low- density polyethylene, using the dynamic mechanical analysis technique. The measurements were carried out over a temperature range of -170 to -100 deg.C, at frequencies of 0.5, 1.0, 2.0, 5.0 and 10.0 Hz and at an average heating rate of 1.83 deg. C/min. The radiation dose was 50, 100, 150, 200, 300 and 400kGy that corresponded to about a cross-linking degree from 20 to 80%. The experimental results have shown that Tg changed about 10 degrees as a function of frequency but for each frequency the value of Tg remained constant as a function of the irradiation dose. At the fixed frequency of 1.0 Hz Tg had a value of-139.4±0.1 deg. C and the activation energy was 51.2±0.7kJ.mol-1. These experimental results have shown that the presence of a three-dimensional interconnected structures and increase in molecular weight, due to the cross-linking effect, had not affected the Tg value at each frequency. It was expected that these molecular modifications could hinder, in some way, the molecular rotational motion, changing this Tg value.

    Palavras-Chave: activation energy; electron beams; frequency dependence; glass; hz range; mechanical tests; molecular weight; polyethylenes; radiation doses; temperature range 0065-0273 k; transition temperature

  • IPEN-DOC 24224

    BORRELY, S.I. ; SAMPA, M.H.O. ; DUARTE, C.L. . Electron beam application for studies carried out with real domestic sewage from São Paulo wastewater treatment plants. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 101-102.

    Observação: Report Number IAEA-SM-366/145

    Abstract: The incompatibility between industrial development and clean environment requires intensive search for waste mitigation technology. Since the aquatic resources have been the most impacted from the environments, improvements on wastewater treatment technologies have been considered. The Nuclear Research Institute has dedicated attention to this problem since 1990. According to the Governmental Sewage Company, SABESP, Sao Paulo Metropolitan Region, RMSP, is treating 18 cubic meters of sewage per second at five stations. The throughput of each station is: ETE Barueri - 9.5 m3/s; ETE ABC - 3.0 m3/s; ETE Sao Miguel - 1.5 m3/s; ETE Parque Novo Mundo - 2.5 m3/s and ETE Suzano - 1.5 m3/s. Real effluents from the municipalities have been submitted to electron beam accelerator for different purposes, and using batch system. The samplings were composite and the wastewater were irradiated at Pyrex vessels, 246 mL per sample. The radiation doses were defined by current variation and the energy was fixed in 1.4MeV. The conveyor velocity was 6,72 m/min. A Dynamitron EBA, 37,5kW was the electron source.

    Palavras-Chave: dynamitrons; electron beams; liquid wastes; mev range 01-10; performance; power range 10-100 kw; waste water

  • IPEN-DOC 23990

    MARIN-HUACHACA, NELIDA S. ; VILLAVICENCIO, ANNA L.C.H. . DNA comet assay as a rapid detection method of irradiated bovine meat by electron beam. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 98-98.

    Observação: Report Number IAEA-SM-366/143

    Abstract: Introduction: The presence in food of pathogenic microorganisms, such as Salmonella species, Escherichia coli 0157:H7, Listeria Monocytogenes or Yersinia enterolitica, is a problem of growing concern to public health authorities all over the world. Thus, irradiation of certain prepackaged meat products such as ground beef, minced meat, and hamburgers may help in controlling meatborne pathogens and parasites. Pathogenic microorganisms and parasites in meat products, which are commonly consumed raw, are of particular importance, Up to now, only electron-beam accelerators and gamma-ray cells have been used for commercial applications. At the international conference on 'The Acceptance, Control of, and Trade in Irradiated Food', it was recommended that governments should encourage research into detection methods (Anon, 1989), Already five international standards are available to food control agencies. A number of physical, chemical, and biological techniques of detection of irradiated foods have been discussed in the literature. A rapid and inexpensive screening test employing DNA Comet Assay to identify radiation treatment of food has been described by Cerda et al. (1997). This method is restricted to foods that have not been subjected to heat or other treatments, which also induce DNA fragmentation. Advantages are its simplicity, low cost and speed of measurement. This method was proposed to the European Committee for Standardization (CEN) as a screening protocol (presumptive) and not as a proof (definitive). The DNA comet assay have been yielded good results with chicken, pork, fish meat, exotic meat, hamburgers, fruits and cereals. In this work we studied a DNA fragmentation of bovine meat irradiated by electron beam. Experimental: Bovine meat was purchased in local shops in Sao Paulo. Irradiation was performed with electron beam of accelerator facility of Radiation Dynamics Inc., USA (E=1,5 MeV, l=25 mA). The irradiation doses were 3,5; 4,5, 5,5, and 7,0 kGy at chilled conditions, and 3,5,4,5; 6,0; 7,0 and 8,0 kGy at frozen conditions. The thickness of meat was less than 0,5 cm. Briefly, meat samples were crushed with a mortar and pestle and was transferred to 1ml ice-cold PBS. This suspension was stirred for 5 minutes and filtered. 100μl cell suspension was mixed with 500μl of low-melting agarose (0,8% in PBS). 100μl of this mixture was spread on pre-coated slides. The caste slide were immersed in lysis buffer (0.045M TBE, pH 8.4, containing 2,5% SDS) for 15 minutes. Electrophoresis was carried out using the same TBE buffer, but devoid of SDS, at a potential of 2V/cm for 2 minutes. Silver staining was carried out for 20 minutes following fixing. Duplicate measurements for each sample were carried out and 100 cells were counted for each dose level. The migration patterns of DNA was evaluated with a standard microscope. Results and Discussion: In the work with Comet Assay, increasing DNA degradation was characterized by different migration patterns of DNA, Some differences were observed between chilled and frozen conditions. The storage time influenced the DNA degradation. Conclusions: It was concluded that the comet assay could be used for detection of processing of irradiated bovine meat by electron beam. Also, this method could be used as a freshness indicator.

    Palavras-Chave: biological radiation effects; dna damages; dynamitrons; electron beams; food processing; irradiation; irradiation devices; meat

  • IPEN-DOC 21612

    ARAUJO, S.G. ; SCIANI, V. . Automated irradiation systems for use in cyclotrons. In: INTERNATIONAL SYMPOSIUM ON UTILIZATION OF ACCELERATORS, November 26-30, 2001, São Paulo, SP. Abstract... Vienna, Austria: International Atomic Energy Agency (IAEA), 2001. p. 28-29.

    Observação: Report Number IAEA-SM-366/106

    Abstract: The objective of this work was the development of irradiating systems completely automatized, always aiming to reduce the radiation exposition dose to the workers and to increase the reliability of use of these systems, because very high activities are expected in these processes.

    Palavras-Chave: automation; computerized control systems; cooling systems; cyclotrons; irradiation devices; mev range 10-100; proton beams; target chambers

  • IPEN-DOC 28975

    ZEZELL, DENISE M. . Machine learning methods for micro-FTIR imaging classification of tumors and more. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 45., 10-14 de abril, 2022, São Paulo, SP. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: Fourier transform infrared micro-spectroscopy imaging (µ-FTIR) has emerged as one of the important tools for studying and characterizing biological materials. It is a label-free technique, relatively simple, reproducible, non-destructive to the tissue and provides accurate results. The vast amount of data and fundamental information obtained from hyperspectral images may not be readily evident. Classical statistics, through its models (parametric and non-parametric) is not able to support the increasing volume of generated data and its high dimensionality. The multivariate analysis of data presents many advantages to be explored, capable of extracting information from the infrared spectra, which go beyond the one-dimensional space, revealing characteristics or properties in the data collected from the samples. The spectral data analysis pipeline, such as the pre-processing steps and the modeling that the Biophotonics Laboratory at Ipen – Cnen, is using in the analysis of biological tissues will be discussed. Results will be presented for body fluids in the disease diagnosis, as well as thyroid, skin and breast tumors, in particular the expression of estrogen and progesterone receptors through tumor biopsies of human cell lines inoculated in mice. µ-FTIR images were collected from histological sections, and six machine learning models were applied and evaluated. The Xtreme gradient boost and Linear Discriminant Analysis showed the best accuracy results, indicating that they are potential models for breast cancer classification tasks.

    Palavras-Chave: fourier transformation; infrared spectra; animal tissues; neoplasms; tumor cells; diagnostic techniques

  • IPEN-DOC 28974

    CASTRO, PEDRO A.A. de ; DIAS, DERLY A. ; ZEZELL, DENISE M. . Chemometric analysis of bone dose response: a preliminary study of FTIR spectroscopy. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 45., 10-14 de abril, 2022, São Paulo, SP. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2022.

    Abstract: The use of ionizing radiation for treatment and diagnosis of many diseases has been well documented. The health effects of ionizing radiation improved patient care, however, incorrect handling of radiation technology may pose potential health risks. In light of this, Fourier-transform infrared spectroscopy combined with attenuated total reflectance (ATR-FTIR) offers a nondestructive, label-free technique for identifying functional groups in biological samples. In this work, fragments of bone were collected from bovine femur diaphysis. Samples were cut and polished until 1 cm x 1 cm x 1 mm, which were then stored properly in the refrigerated environment. Samples irradiation was performed with a multipurpose irradiator of Cobalt-60 at doses of 15 kGy and 25 kGy.Spectral data was submitted for the second derivative. Thereafter, the amplitude of the second derivative was organized for hierarchical clustering in conjunction with a heatmap. In order to carry out the chemometric analyses, all procedures were performed using MATLAB (The Mathworks Inc., Natick, MA, USA). Based on these results, an examination of the cluster heatmap reveals that the unique behavior for each group which may be correspond to the ionizing radiation change in the spectra. Hence, these findings suggest new possibilities for spectral monitoring of dose responses.

    Palavras-Chave: chemotherapy; radiation doses; skeleton; radiation monitoring; infrared spectra; fourier transformation

  • IPEN-DOC 28973

    ANDRADE, IZABEL da S. ; ARAUJO, ELAINE C. ; CORREA, THAIS ; MACEDO, FERNANDA de M ; LANDULFO, EDUARDO . Spatial-temporal analysis of NO2 in the Metropolitan Region of São Paulo. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 68-68.

    Abstract: Nowadays, several methods of monitoring air pollutants exist, however few allow a large spatial and temporal coverage. Sentinel-5P is a satellite dedicated to atmospheric monitoring with a high spatial-temporal resolution, offering a large data of miscellaneous chemical species. Nitrogen oxides (NO and NO2), emitted by anthropogenic activities into the atmosphere - in large urban centers their main emitting source is vehicles - need particular attention, , in addition to being primary pollutants, they are precursors for formation of other chemical species due to photochemical reactions, mainly tropospheric ozone. These photochemical interactions of NOX stimulate to reduce its lifetime in the atmosphere. Furthermore, these pollutants are used as air quality indexes. The Metropolitan Region of São Paulo (MRSP) has more than 30 cities, being an important economic center for the state of São Paulo. The MRSP has highways with high circulation of light and heavy vehicles, industries and also a high population density. Such factors make this region a favorable area for a satellite study. Thus, the present work uses Sentinel-5P NO2 L2 data in order to analyze the evolution of concentrations throughout 2019.

    Palavras-Chave: air pollution; nitrogen dioxide; pollution control; air pollution monitoring; urban areas

  • IPEN-DOC 28972

    PALLOTTA, JUAN; LOPES, FABIO ; BARBOSA, HENRIQUE M.J.; CARVALHO, SILVANIA A.; CACHEFFO, ALEXANDRE; LANDULFO, EDUARDO . Collaborative development of a Lidar Processing Pipeline. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 52-52.

    Abstract: Aerosols, clouds and their interactions are the source of the largest uncertainties in current climate change estimates. More frequent and higher quality measurement of aerosol, clouds, and the physical processes governing their link with climate are needed to reduce these uncertainties, and lidars are a powerful instrument to accomplish this task. However, lidars are generally developed by individual groups for particular applications, and hence typically have very different characteristics. In this sense, lidar networks play a key role as they coordinate the efforts of different groups, providing the guidelines for quality-assured routine measurements on a regional scale. Moreover, a coordinated effort is of utmost importance to homogenize the physical retrievals from the highly non-uniform instruments in a network. This is only possible with the development of a unified processing pipeline that accounts for the hardware heterogeneity in the pool of instruments. Here, we describe an ongoing effort to collaboratively develop a Lidar Processing Pipeline. The LPP is a collection of tools developed in C++ and Python that are planned to handle all the steps of lidar analysis. A first tool converts the raw data files into a single NetCDF file, including detailed information about the instrument and acquisition setup (Level 0 dataset). . Then, this is processed by another tool which applies the necessary corrections and computes the cloud-mask (Level 1 dataset). The final step is the elastic and/or inelastic retrieval of aerosol properties (Level 2 dataset). The development of LPP has been based on the existing analysis routines developed by individual groups, and hence takes advantage of previous efforts for algorithm comparison in the scope of Lalinet Network. A general concept and first steps of the ongoing project are reported, as well as the next steps towards the release of the first operational version of the processing pipeline.

    Palavras-Chave: methane; greenhouse gases; atmospheric circulation

  • IPEN-DOC 28971

    CORREA, THAIS ; MACEDO, FERNANDA M. ; ARAUJO, ELAINE C. ; ANDRADE, IZABEL S. ; GOMES, ANTONIO A. ; SILVA, JONATAN ; LANDULFO, EDUARDO . Methane determination in São Paulo coastal regions using the Cavity Ring-Down Spectroscopy (CRDS) technique. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 50-50.

    Abstract: Methane is one of the main greenhouse gases due to its high radiation absorption capacity. The increase in methane emissions from anthropogenic sources causes concern in the entire scientific community due to the aggregated uncertainties, generating several works focused on the identification and quantification of generating sources. This work aims to quantify methane in two distinct regions, the first study region is in Cubatão city, located in the São Paulo coast. It is an important petrochemical complex with high industrial activities and environmental impact, presenting 25 large companies in the chemical sector, distributed in an area of 143 Km2. Another region observed is Intanhaém, on the coast of the state of São Paulo. This region doesn´t present industrial activity and has a low population index. The technique used to detect methane in the atmosphere was Cavity ring-down spectroscopy (CRDS), which consists on analysis of atmospheric components, in a small cavity that has a laser and high reflectivity mirrors of 99.999%, allowing the signal travel for kilometers inside the cavity, in a short time, increasing the sensitivity of detection of compounds in the sample.

    Palavras-Chave: greenhouse gases; methane; cavity resonators

  • IPEN-DOC 28970

    MACEDO, FERNANDA M. ; LANDULFO, EDUARDO . Use of SNOM for analysis of biomarker molecules when excited by Raman. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 27-27.

    Abstract: During the last decade, many studies have made significant progress in understanding the causes and implications of our environment, with respect to the atmosphere. Bioaerosols are fundamental in the reproduction of plants and microorganisms (pollen, spores, etc.), which in the atmosphere are transported across borders and long distances. For this reason, bioaerosols have great importance in genetic diffusion between habitats and biomas geographic change, contributing as main elements in the development, evolution and ecosystems dynamics. The consequences related to public health and agriculture are associated by the dispersion of plants, animals, pathogens and human allergens, showed an increase of allergies and asthma cases during storms, due to high concentrations of bioaerosols, especially when attributed to fungal spores. The biological content found in the air of global land surfaces corresponds to a quarter of the total particles found in the air, consisting mainly of proteins, arising from pollens, fungal spores, bacteria, viruses or fragments of plant or animal matter. Some proteins act as marker molecules which autofluoresce if excited at a specific wavelength. A signature of biomarker proteins, existing in the cell wall of fungal spores of medical interest, will be developed using scanning near-field optical microscopy (SNOM). This new high resolution optical methodology will allow detailed analysis of biomarker molecules (ergosterol, mannitol and arabitol), as well as their behavior when excited by Raman. In possession of a molecular standard, a database of these characteristics will be created, which will provide technical support for the remote Raman sensing of these species in the atmosphere of the Metropolitan Region of São Paulo (MRSP).

    Palavras-Chave: aerosols; optical microscopy; biological markers; atmospheres

  • IPEN-DOC 28969

    SOUZA, GIOVANNI ; LOPES, FABIO J.S. ; LANDULFO, EDUARDO . Study of optical properties and spatial distribution of cirrus clouds over São Paulo, Brazil, using CALIPSO level 2 data. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 67-67.

    Abstract: Cirrus clouds have an important role in the earth’s radiation budget, they have a wide spatial extension and are the most present type of clouds in the atmosphere, especially in tropical regions (Sassen et al., 2018). Due their thickness, Cirrus clouds are almost transparent for the incoming shortwave solar radiation and opaque to the longwave emitted by the planet's surface. Despite the importance of Cirrus clouds in the earth’s climate, there is a lack of studies focused on this type of cloud in the southern hemisphere. Since 2006, the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), a joint mission between NASA and the French space agency, CNES, provides physical and optical information of clouds and aerosols to improve the understanding of their role in the climate, air quality and radiation budget in the Earth. The primary instrument of CALIPSO payload is the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), which is a lidar system operating on 1064 nm and 532 nm (with parallel and perpendicular polarization) wavelengths. CALIOP provides as level 1 data, high-resolution vertical profiles of aerosols and clouds. In turn, the level 2 data provides processed products such as cloud-aersol discrimination, cloud base and top layer altitude, and cloud optical depth. The aim of this work is use the CALIOP global coverage to study the physical and optical properties of Cirrus clouds over the São Paulo State (roughly centered on 21.3°S, 50.3°W), in Brazil. We have employed a statistic analysis of 9 years (2007-2015) of data using the level 2 products to obtain spatial distribution and optical properties of cirrus clouds over São Paulo state, in order to understanding the long-term trend of Cirrus clouds coverage in the São Paulo state and later on Brazil.

    Palavras-Chave: optical radar; clouds; satellites; earth atmosphere; solar radiation

  • IPEN-DOC 28968

    MEDEIROS, PEDRO A. ; MARQUES, MARCIA; LANDULFO, EDUARDO . Limits of a prediction model using RNN with four layers LSTM for CRDS data. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 57-57.

    Abstract: Prediction models can be very useful when dealing with ciclic temporal sequence of data. For ciclic sequences that have caotic behavior, like atmospherics measures, the Recurrent Neural Network(RNN) is a potential option to create acurate prediction models.This type of neural network is effective in dealing with temporal sequences because it uses its internal state as a memory to process certain data intervals. In building the model, it is necessary to use layers with neurons to discern a trend that the data sequence takes, for this, in the RNN model it is possible to use the long short-term memory (LSTM) architecture to more easily predict unusual behaviors in the data stream, since its use facilitates the recognition of long-term sequences in the analyzed sequence. This type of architecture can be added in layers to increase model efficiency. For the training and testing of the model, data obtained by the Metroclima project with a Cavity Ring Down Spectroscopy (CRDS) at the UNICID station located in São Paulo were used, with the data ranging from 2019 to 2021. In this process, four LSTM layers will be used to create a prediction model that will be tested to its limit on the effectiveness of predicting atmospheric data of this type.

    Palavras-Chave: neural networks; cavity resonators; computerized simulation

  • IPEN-DOC 28967

    ARAUJO, ELAINE C. ; ANDRADE, IZABEL da S. ; MACEDO, FERNANDA de M. ; CORREA, THAIS ; LANDULFO, EDUARDO . Preliminary study of greenhouse gases in the Santos Basin. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 49-49.

    Abstract: The production of oil and gas onshore and offshore are associated with significant emissions of greenhouse gases, as the entire production chain of oil exploration is a potential source of emission of these gases, especially CH4, which is in almost all stages of the process However, few data is available on emissions from oil exploration platforms in Brazil, despite the increase in oil production on the Brazilian coast since 2008 with the implementation of the Pre-Salt program, which aims to explore oil in the pre-salt layer. Between the explored areas is the Santos Basin which occupies about 350,000 km2 and is located in the southeast region of the Brazilian continental margin, approximately 290 km off the coast of Rio de Janeiro and encompasses the coastlines of the States of Rio de Janeiro, São Paulo , Paraná and Santa Catarina, with boundaries to the north with the Campos Basin by the Alto de Cabo Frio and to the south by the Pelotas Basin by the Florianópolis Platform. Better understanding the ocean-atmosphere interactions in the Santos Basin region, specifically in the coastal area of São Paulo, a temporal analysis was performed using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument, which provides data on active burning and from Sentinel-5P (Sentinel 5 Precursor satellite) which brings information from several chemical species, such as NO2 and CH4.

    Palavras-Chave: greenhouse gases; oils; gases; greenhouse effect; petroleum

  • IPEN-DOC 28966

    SILVA, THAIS A. da ; OLIVEIRA, CARLOS E.S. de; CRUZ, DANILO D.; MEDEIROS, ILCA M.M.A. ; MEDEIROS, JOSE A.G. de ; OLIVEIRA, LUCAS P.; MARQUES, MARCIA T.A.; MEDEIROS, PEDRO A. ; ANDRADE, MARIA F.; LANDULFO, EDUARDO . Measurement of greenhouses gases in the city of Sao Paulo: assessing methane concentrations and sources. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 48-48.

    Abstract: The gases that most contribute to the greenhouse effect are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). When those gases have been in the atmosphere for a long time, its effects become almost irreversible with the radiative forcing of years, until natural processes manage to remove the quantities already emitted. Methane is a radiative agent and happens significantly in the southern hemisphere. Methane is a major source of water vapor. When the concentration of water vapor in the stratosphere increases, it contributes to intensifying the greenhouse effect. The large part of carbon dioxide and methane absorbed by the ocean, atmosphere and biosphere, contributes to the global carbon cycle, bringing a stable carbon rate in the air. Forest fires are often responsible for releasing carbon dioxide and methane. It is important to consider the role of photosynthesis in the balance between anthropogenic process, climate change and air quality. Therefore, forest preservation and reforestation projects are fundamental against climate change. The main purpose of Metroclima Project is to assess the sources of greenhouse gases and short-lived pollutants in Sao Paulo and neighboring cities, in the Southeast of Brazil. Currently, the GHG measurement network has four stations (IAG Station, Pico do Jaragua, UNICID and ICESP) extended across the City of Sao Paulo, measuring carbon dioxide and methane concentrations continuously using Cavity Ring Down Spectroscopy (CRDS) instruments. In specific, the goal of this study is related to assessment of methane concentration variability and identification of potential sources near UNICID Station – an urban site; using the CRDS Picarro G2401 system. The data analysis acquired during 2020 and 2021 will be shown. Our results comprise a valuable contribution to the knowledge about methane concentrations in the city and guide public decision based on scientific evidence.

    Palavras-Chave: climatic change; greenhouse effect; greenhouse gases; methane; carbon dioxide; nitrous oxide

  • IPEN-DOC 28965

    ANTUNA-MARRERO, JUAN C.; ARREDONDO, RENE E.; LANDULFO, EDUARDO ; VEGA, ALBETH R.; SANCHEZ, JUAN C.A.. Extending LALINET observations to the Upper Troposphere and Lower Stratosphere (UTLS): a challenge in the post-COVID-19 era. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 36-36.

    Abstract: By the end of the XX century the lack of resources in the Latin America was not an obstacle to create the Latin America Lidar Network (LALINET). The strategy to build LALINET was to create first a lidar community in the region from the few lidar teams (mainly measuring in the troposphere). A little more than two decades later LALINET resilience will be tested by the post-COVID-19 era. In Latin America the economic crisis resulting from the COVID-19 health crisis will reduce notably funds for many activities, including scientific research. LALINET contingency strategy (to be discussed and approved at the XI WLMLA) has as its main goal to maintain the level of tropospheric aerosols observations and research activities reached during the last decade. However, the contingency strategy has several other goals, including extending LALINET observations to the UTLS making use of the existing lidar facilities. We have been setting up progressively a program for UTLS regular measurements, making use of the existing lidar facilities. It consist in four main steps: 1) Lidars currently retrieving tropospheric aerosols profiles will be tested for its signal to noise ratios in the region of the UTLS to determine if its current characteristics allows retrieving aerosol backscatter profiles in that region; 2) designing the algorithm to be used and implement the version 1 of LALINET standard software/scripts to produce UTLS aerosol backscatter and extinction profiles; 3) implement the processing of UTLS observations at each site having that capabilities; 4) conduct the processing of all the stored profiles at those sites. Several studies on stratospheric aerosols conducted in the region and abroad have accumulated know-how that is being and will be applied to the retrieval of UTLS aerosols lidar backscattering and extinction profiles at LALINET sites. The presentations will show and discuss those studies and also describe the current status of the four steps listed above.

    Palavras-Chave: optical radar; aerosols; troposphere; stratosphere

  • IPEN-DOC 28964

    CARVALHO, SILVANIA A.; LOPES, FABIO J.S. ; SILVA, JONATAN J. da ; MENEGATTI, CARLOS R.; CATALANI, FERNANDO; TODERO, CARLOS J.; RIBEIRO, FABIO de J.; ALMEIDA, ROGERIO M. de; LANDULFO, EDUARDO . LIDAR first campaign in the industrial sites of Volta Redonda-RJ and Lorena-SP, Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 29-29.

    Abstract: Air pollution is recognized as a risk factor for health. The emission of toxic gases and particulates, specially with diameter size smaller than 10 μm, into the atmosphere by industries is correlated with increasing respiratory problems, mortality and cancer in some urban areas. Additionally the aerosol particles play an important role in the Earth’s radiation budget and the understanding of their properties is important to address their effects on the climate and weather conditions. In this study we will present some results of aerosol vertical distribution retrieved using a mobile lidar system and the lidar system on board of the CALIPSO satellite platform. The synergetic use of these platforms helped to understand the impact of the aerosol suspended in the atmosphere in terms of its optical properties in two different sites between two main metropolitan areas of Brazil, which are São Paulo and Rio de Janeiro. In order to obtain a statistical characterization of the aerosol optical properties, level 2-version 4 data from CALIPSO were employed to retrieve the AOD and Lidar ratio values at 532 nm for Volta Redonda and Lorena sites. Lorena campaign was performed during a very dry period in the 2014 Southern hemisphere winter, where it detected the vertical distribution profile with several layers detached from the aerosol boundary layer (ABL) on 26th of June 2014. Volta Redonda-RJ campaign performed from the beginning of November until mid of December of 2018 provided detection of aerosol layers detached from ABL on 4th of December of 2018. We will present a brief description of the experimental apparatus, the data taking, the methodology and the main results which open up the possibility to investigate emission of toxic gases and particulates at this region which has high contribution to local atmospheric pollution due to the Presidente Dutra highway (BR 116), the Companhia Siderúgica Nacional (CSN) and other metallurgical and cement factories.

    Palavras-Chave: satellites; optical radar; aerosols; urban areas

  • IPEN-DOC 28963

    MORAIS, FERNANDO G. ; FRANCO, MARCO A.; BARBOSA, HENRIQUE M.J.; JORGE, FABIO; ARTAXO, PAULO; LANDULFO, EDUARDO . Seasonal analysis of Brown Carbon, Black Carbon and Dust at Central Amazonia with Ångström Matrices. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 24-24.

    Abstract: Aerosol optical properties are an important and direct way to understand and quantify the seasonal effects of the Amazonian aerosol by means of the intensive optical properties: absorption and scattering Ångström exponent. AERONET photometers measure the aerosol optical properties and associated with a set of algorithms, obtain information of the aerosol physical characteristics such as the aerosol optical depth (AOD) and the absorption aerosol optical depth (AAOD) almost in real time. For the last 22 years, those properties have been measured at several AERONET sites using CIMEL sun photometers in Amazon. Measurements were done in Central Amazonia (Manaus and ATTO tower), as well as in the deforestation arc: Rio Branco, Cuiabá, Ji-Paraná, and Alta Floresta, and results have shown important geographical and seasonal variability in terms of aerosol impacts. We can access the seasonal Brown Carbon, Black Carbon, and Dust calculating the Ångström matrix with absorption and scattering Ångström exponent. We observe a clear separation between dry and wet season, and in the later, also a period in which Dust comes from Saara (mostly between January to April). Therefore, it was possible to observe Brown Carbon (BrC) in addition to Black Carbon (BC), which is responsible for 12% of the AAOD of aerosols at 440nm in the deforestation arc in sites that are about 1000 km apart and show consistency very good. As for pristine sites, such as the ATTO site, the contribution of BrC is 25% in relation to the AAOD at 440nm where we have very little human interference.

    Palavras-Chave: aerosols; carbon black; amazon river; dusts

  • IPEN-DOC 28962

    SANTOS, AMANDA V. ; LANDULFO, EDUARDO ; MOREIRA, GREGORI A. ; MARQUES, MARCIA T.A.; ANDRADE, MARIA F.. Comparing lidar and ceilometer backscattering measurements for the detection of aerosol layers in the PBL over São Paulo, Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 22-22.

    Abstract: The Planetary Boundary Layer (PBL) is the lowest part of the troposphere and it is directly influenced by the Earth’s surface and anthropogenic activities. The concentration of aerosol in the PBL is typically much higher than in the free troposphere. Given that most of the air pollution in the troposphere is capped by this layer, obtaining the PBL height (PBLH) and its evolution during the day can assist in monitoring and studying aerosol concentrations and properties and its impact on air quality. Multi-instrument monitoring of the PBLH can assist in identifying the arrival of different air masses and tracking the evolution of aerosol layers during the day. Due to their lower cost, ceilometers can be powerful tools to enhance these measurements, although such an instrument has a few limitations when compared to lidars. The weaker laser light source used in ceilometers can limit the detection of aerosol layers to a few kilometers in height, depending on the presence and distribution of clouds and aerosols in the atmosphere. Given that some methods to estimate the PBLH need strong gradients in the concentration of aerosols to identify it correctly, the improper identification of the aerosol layers can become problematic for obtaining the PBLH. We compared lidar and ceilometer data from two instruments located in the city of São Paulo, Brazil, approximately 15 km from each other. We found that, in clear sky conditions, it is possible to correctly identify aerosol layers in the PBL with data from both instruments. The presence of clouds, signal attenuation and noise can sometimes cause errors in the identification of aerosol layers, especially when using ceilometer data. We found that, despite not being co-located, both instruments show similar profiles, up to a few kilometers in height.

    Palavras-Chave: optical radar; boundary layers; layers; aerosols

  • IPEN-DOC 28961

    JESUS, ESTER O. de ; ROSARIO, NILTON M.E. do; YOSHIDA, ALEXANDRE C. ; CACHEFFO, ALEXANDRE ; GUERRERO-RASCADO, JUAN L.; LANDULFO, EDUARDO ; LOPES, FABIO J.S. . Study of aerosol optical properties on South America using AERONET data analysis: preparation for EARTHCare ESA Satellite mission. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 21-21.

    Abstract: In the last decade, a new generation of satellite missions have been developed using advanced lidar systems capable to retrieve several cloud and aerosol optical properties and distinguish different aerosol types by applying a polarization sensitive high spectral resolution lidar (HSRL) technique, as is the case of the Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) mission, developed by the European Space Agency (ESA) together with the Japan Aerospace Exploration Agency (JAXA). The EarthCARE payload will be compound by four main instruments, a cloud profiling radar, with Doppler capability, the HSRL system, a multispectral imager and a broadband radiometer, enabling the retrieval of global profiles of clouds, aerosols, precipitation and radiation field properties. The Atmospheric Lidar system (ATLID) on board of EarthCARE will operate at 355 nm and will use the cross and co-polarized components of Mie and Rayleigh scattering to derive aerosol properties. An important task to be developed by ground-based research groups is the data validation process. In this context, the Latin American LIdar NETwork (LALINET) has been playing a key role in the cloud and aerosol studies by using lidar and/or the AERONET sunphotometers data. In order to prepare the most suitable strategy for calibration and validation (CAL/VAL) processes of the EarthCARE mission, we have employed an extensive study of aerosol optical properties derived from 21 AERONET sunphotometer stations all over South America, from a period of at least 20 year. The aim of this work is to present preliminary results of columnar aerosol optical properties, such as AOD, lidar ratio, scattering and absorption Angstrom Exponent, single-scaterring albedo and aerosol fine-mode fraction, in order to select cluster-zones by aerosol types to guide the validation methodology for ATLID system products, since the continent is dominated by high spatial and temporal variability of aerosol systems.

    Palavras-Chave: aerosols; aerosols; satellites; validation; optical properties

  • IPEN-DOC 28960

    LOPES, PEROLA P.Q. ; LOPES, FABIO J.S. ; LANDULFO, EDUARDO . Study between atmospheric paramenters and pyranometer global radiation measurements at São Paulo, Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 19-19.

    Abstract: According to the recently released report of the Intergovernmental Panel on Climate Change (IPCC) on August of 2021, the well-mixed greenhouse gas (GHG) concentrations have continued to increase in the atmosphere, reaching annual averages of 410 ppm for CO2,1866 ppb for CH4, and 332 ppb for N2O. The GHGs can contribute to warming the atmosphere up to 2.0°C, while aerosols can contribute to cooling up to 0.8°C. in this context, it is increasingly important to monitor the global solar radiation flux incident on the atmosphere. The pyranometer instrument is designed to measure the solar radiation flux density (W/m2) and it can be used to get information about the amount of radiation incident on the ground and how much of this radiation is absorbed or scattered. The aim of this work is to show preliminary results retrieved by Piranometer installed in the SPU Lidar Station, in São Paulo-Brazil, and how the global solar radiation can be correlated with other atmospheric parameters retrieved from AERONET sunphotometer and meteorologic stations, such as the aerosol optical depth (AOD), cloud cover, relative humidity, in order to quantify the aerosol influence in the process of atmospheric radiation and climate change.

    Palavras-Chave: solar radiation; radiometers; optical radar; clouds

  • IPEN-DOC 28959

    CASTRO, P. ; PEREIRA, D. ; ANA, P.; MATOS, C.; ZEZELL, D. . Q-switched Nd:YAG laser on dental enamel with photoabsorber: a confocal Raman pilot study. In: VIRTUAL RAMAN IMAGING POSTER SUMMIT, 1st; INTERNATIONAL CONFERENCE FOR CHEMICAL CHARACTERIZATION & IMAGING, September 28 - October 2, 2020, Online. Abstract... Ulm, Germany: WITec, 2020. p. 33-33.

    Abstract: Nd:YAG lasers emitting λ = 1064 nm at microsecond and nanosecond pulses are alternatives to prevent dental caries and erosion in clinics. This wavelength allows most of photons to penetrate deep in the hard tissue due to low absorption of hydroxyapatite in the region. It is necessary to use photoabsorbers so most of photons are absorbed in the surface of the tissue preventing dental pulp necrosis. Currently the coal paste is used as a photoabsorber but the irradiated tissue turns darker what implies in the patients low adherence to the treatment due to aesthetic reasons. [1,2]. Confocal Raman spectroscopy is a non-destructive optical method to obtain detailed information about molecular composition of biological structures in depth. The most prominent feature of Confocal Raman spectroscopy is the reliable capability to provide the biomolecular data with no use of ionizing radiation to penetrate in the sample. This work aims to characterize the dental enamel irradiated with Nd:YAG laser with nanoseconds pulses, in order to describe the depth related changes promoted in the enamel, by the heat generated due to laser irradiation. For these measurements, 30 bovine enamel blocks of 8 mm2, were randomized into 3 groups: G1 – enamel untreated; G2 – enamel irradiated with Nd:YAG nanopulsed laser (1064 nm, 4 W; 1,05 J/cm2; 5 ns 20 Hz, Brilliant, Quantel Laser) using a coal paste as photoabsorber; G3 -enamel irradiated with Nd:YAG nanopulsed laser ( same parameters as G2) using squid ink as photoabsorber. The assessments of three different depth regions of the cubic shaped samples were: region A- left corner above of the sample, region B-middle of the sample and Region C- right corner below of the sample. The intensity map of phosphate (950 cm-1) regarding the position, were calculated [3,4] as shown in the Figure 01. The comparative results in the Fig.1 demonstrated that application of coal paste associated with Nd:YAG (G2) can preserve the inorganic content better than the squid ink group (G3). These findings have crucial clinical implications in the laser protocol development and it was possible to correlate the heat penetration depth of the laser irradiation with photoabsorber using the images obtained by the confocal Raman.

    Palavras-Chave: teeth; enamels; lasers; raman spectroscopy; absorption; neodymium lasers; q-switching

  • IPEN-DOC 28958

    D'AGOSTINO, GIANCARLO; BLAAUW, MENNO; DUNG, HO M.; LUZIO, MARCO di; JACIMOVIC, RADOJKO; DIAS, MAURO da S. ; SEMMLER, RENATO ; SLUIJS, ROBBERT van; BARRADAS, NUNO P.. The 2021 IAEA software intercomparison for k0-INAA. In: INTERNATIONAL k0-USERS’ WORKSHOP, 8th, June 6-10, 2022, Ljubljana, Slovenia. Abstract... Ljubljana, Slovenia: Institut "Jožef Stefan", 2022. p. 17-17.

    Abstract: In order to establish the variation between results due to software implementation in mass fractions as measured by the k0-method for INAA, the IAEA has organized a software intercomparison. A complete set of test spectra and associated information was assembled. Efficiency curves, neutron spectrum parameters, correction factors and mass fractions were calculated with the participating programs (list of program names here) using identical peak areas. In this paper, we report on the observed discrepancies, causes, remedies and future software developments. The test data, as well as expected and certified mass fractions of the BCR-320R channel sediment sample material will be made available to all.

    Palavras-Chave: neutron spectra; neutron activation analysis; computer codes; comparative evaluations

  • IPEN-DOC 28957

    DIAS, MAURO da S. ; SEMMLER, RENATO ; KOSKINAS, MARINA F. ; MOREIRA, DENISE S. ; YAMAZAKI, IONE M. ; BRANCACCIO, FRANCO ; BARROS, LIVIA F. ; RIBEIRO, RAFAEL V. ; MORAIS, THALES S.L. de . k0-IPEN / a new software for Instrumental Neutron Activation Analysis. In: INTERNATIONAL k0-USERS’ WORKSHOP, 8th, June 6-10, 2022, Ljubljana, Slovenia. Abstract... Ljubljana, Slovenia: Institut "Jožef Stefan", 2022. p. 16-16.

    Abstract: A new software package for INAA, developed at the Nuclear Metrology Laboratory (LMN) of the Nuclear and Energy Research Institute (IPEN-CNEN/SP), called k0-IPEN, is described. The package consists of a main program linked to nine subprograms designed to perform automatically all the tasks necessary in order to obtain the mass fractions of the irradiated samples. The goals of these nine routines are: a) to calculate the experimental peak efficiencies and P/T ratios for the standard sources, together with all the corresponding uncertainties; b) to correct the peak efficiencies for coincidence summing; c) to fit the peak efficiencies and P/T ratios with log-log polynomial functions; d) to determine experimentally the  and f parameters by the Triple Bare and by the Cd Ratio Multimonitor Methods; e) to correct for interferences; f) to determine the average mass fractions, taking into account the correlations among all partial uncertainties involved. In the present version, the only data that must be inserted as input parameter, externally from the package, are the self-shielding correction factor, which is calculated by the MATSSF code, and the geometry factor that corrects for the difference between sizes of standard sources and measured samples. The code can deal with different spectrum formats such as CHN, SPE and CNF. The routine designed to calculate the peak areas has a simple algorithm and is not yet capable of separating multiplets. Therefore, it is suitable for analysing separated peaks, such as those found in standard calibration source measurements. However, for complex spectra, the code can read peak list files obtained from other codes, such as HyperMet or HyperLab. External efficiency curves calculated by the Monte Carlo code MCNP6 can be read to extend the calibration curve to regions where there are only a few experimental points available. The code k0-IPEN is being tested and its validation accomplished by means of an intercomparison sponsored by the IAEA, and presented at this conference.

    Palavras-Chave: computer codes; programming; neutron activation analysis; monte carlo method

  • IPEN-DOC 28908

    BASSO, LUANA; GATTI, LUCIANA ; MARANI, LUCIANO; MILLER, JOHN; GLOOR, MANUEL; MELACK, JOHN; CASSOL, HENRIQUE; TEJADA, GRACIELA; DOMINGUES, LUCAS ; ARAI, EGIDIO; SANCHEZ, ALBER; CORREA, SERGIO; ANDERSON, LIANA; ARAGAO, LUIZ; CORREIA, CAIO ; CRISPIM, STEPHANIE; NEVES, RAIANE. Regional variability in Amazon methane emissions based on lower-troposphere observations. In: EGU General Assembly, May 23-27, 2022, Vienna, Austria. Abstract... Göttingen, Germany: Copernicus, 2022.

    Abstract: After a period where atmospheric methane (CH4) levels were nearly steady, its levels have been rapidly raising since 2007, but the main reasons remains uncertain. Increases in wetlands emissions could be one possible reason, mainly at tropical regions like Amazonia, which host some of the largest wetlands/seasonally flooded areas on the globe. Based on 590 lower troposphere vertical profiles of CH4 and carbon monoxide (CO) observations over four sites at Amazon (at the northeast, southeast, northwest-central and southwest-central regions) we estimated that Amazon region contributes with 8% of global CH4 emissions, and wetlands are the mainly CH4 source to the atmosphere (Basso et al., 2021). Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and CO analysis of flask air, fortnightly between 2010 and 2018. We observed an unexpected east-west gradient in CH4 emissions, with higher emissions in northeast Amazon region. The higher emissions are mainly from wetlands and are not explained by biomass burning and anthropogenic emissions (like enteric fermentation), but its causes remains unclear. In the other three sites located further downwind along the main air-stream the CH4 emissions represents approximately 24-36% of what is observed in the northeast region. Our wetlands emission estimates of each region were compared to analogous fluxes from the WetCharts wetland model ensemble (Bloom et al., 2017). The estimates were similar except for the northeast region, where WetCharts does show substantial emissions, but still just 40% of our estimates based on the lower troposphere observations (Basso et al., 2021).

  • IPEN-DOC 28907

    TEJADA, GRACIELA; GATTI, LUCIANA V. ; BASSO, LUANA S.; MATAVELI, GUILHERME A.V.; CASSOL, HENRIQUE L.G.; VON RANDOW, CELSO. Forest biomass: an uncertainty source of land use and land cover change related carbon emissions in the Amazon. In: EGU General Assembly, May 23-27, 2022, Vienna, Austria. Abstract... Göttingen, Germany: Copernicus, 2022.

    Abstract: Tropical forest plays a fundamental role in the ecosystem services maintenance. Amazon forests have been subject to intense land use and cover changes (LUCC), mainly in the Southeast portion. Like many tropical countries, more than 70% of Brazilian greenhouse gasses emissions come from LUCC. Under the framework of the CARBAM Project, atmospheric CO2 measurements in four sites of the Amazon, show that there is a reduction in the Amazon forest capacity to absorb C in the proximities of previous deforested and degraded forest areas, such as the well-known “Deforestation Arc” in the Southeast amazon. There are many LUCC databases now available that allow to assess the deforestation, degradation and second forest dynamics and contribute to a better understanding of the carbon dynamics of nine years of in situ atmospheric CO2 measurements. Nevertheless, in order to know how much CO2 is released to the atmosphere due to LUCC, it is necessary to quantify how much carbon is stored in the forest biomass and to assess the biomass variability along the different datasets. Here we compared the forest biomass quantity of three biomass maps: the fourth national communication of Brazil map (official), a global map (Baccini et al. 2012) and a regional map for the Brazilian Amazon (EBA project). We found significant differences for the Brazilian Amazon: between the official biomass map and the regional map 27%, between the global and regional map 25% and the smallest difference was between the official and the global map (3%). Even though the official and the regional maps were obtained using the same data inputs, the official map refers to a potential biomass for 2010 and the regional map reflects the real biomass in 2016, this could explain the difference. The official and global maps represent the potential biomass, and as we used the mean forest area, the biomass content is similar. When comparing these maps at a deforested pixel level the differences could be larger. The spatial and temporal scale of biomass maps make it hard to estimate the CO2 emissions of degradation and secondary forest loss and growth which are fundamental to understand the Amazon C balance under climate change and LUCC pressures.

    Palavras-Chave: greenhouses; deforestation; carbon dioxide; land use; forests; emissions tax; amazon river; forests

  • IPEN-DOC 28901

    SILVA, CAMILA R. ; PEREIRA, SAULO T. ; CONTATORI, CAROLINA G.S. ; PINTO, MAYARA S. ; SALVEGO, CAMILA A. ; RIBEIRO, MARTHA S. . Efeitos da fotobiomodulação pré-exposição à radiação ionizante em células de câncer de mama. In: FÓRUM ON-LINE DE TECNOLOGIAS DA LUZ NA SAÚDE, 2nd, May 20-22, 2021, Online. Resumo expandido... Campinas, SP: Faculdade São Leopoldo Mandic, 2021.

  • IPEN-DOC 28900

    VIVEIROS, BARBARA V.G. de ; BERBEL, LARISSA O. ; DONATUS, UYIME ; COSTA, ISOLDA . The corrosion behavior on AA2050-T84 and AA7050-T7451 welded and non-welded by FSW. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: In this work, the corrosion resistance of the AA2050-T84 and AA7050-T7451 alloys welded by FSW and non-welded was investigated using chloride solutions. The corrosion resistance, microstructure and microhardness were studied. Microhardness measurements at the cross section and at the top surface of the weld identified significant differences between the various zones resulting from FSW. Characterization of the corrosion resistance was carried out by electrochemical and immersion tests. Localized electrochemical techniques were used in this work, specifically scanning vibrating electrode technique (SVET) and scanning ion-selective electrode technique (SIET). The results showed that the most electrochemically active zone at of the welded alloys was the thermomechanically affected zone (TMAZ). This zone corresponds to the transition between the two alloys. In the top surface of the welded alloys, besides the TMAZ, the heat affected zone (HAZ) was also highly active corresponding to the transition between zones of the AA7050. This was due to the formation of hardening precipitates in the HAZ of the AA7050. In the cross-section, the high activity related to the TMAZ was due to the galvanic coupling between the two alloys where the AA7050 alloy acted as anodic zones, and the AA2050, as the cathodic ones. When the two alloys, AA2050 and AA7050, were exposed separately to 0.005 mol.L-1 NaCl or 3.5 (wt%) NaCl solutions, the AA2050 alloy showed higher electrochemical activity compared to the AA7050 alloy which was due to the higher content of active micrometric precipitates in the AA2050 alloy relatively to the AA7050. However, when the alloys were coupled, the AA2050 was cathodically protected by the AA7050 alloy.

  • IPEN-DOC 28899

    FONSECA, DANIELA P.M. da; LIMA, NELSON B. de ; PADILHA, ANGELO F.. Oxidation behavior of ultra-high-strength 13Ni15Co10Mo maraging steel. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: During solution annealing and aging of maraging steels an oxide layer is formed, usually composed of hematite and/or magnetite. Exploratory analysis of the oxidized surface of 13Ni-15Co-10Mo (wt.%) maraging steel also indicated the presence of austenite. This maraging steel presents ultra-high yield strength (~3 GPa), however, it shows lower toughness than other maraging steel types and the austenite phase on the surface could obstruct crack initiation and propagation improving toughness. The aim of this study was to investigate the microstructure of the steel surface after oxidation in air by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDX) and X-Ray Diffraction (XRD). Results showed that there are three different regions after oxidation: bulk (constituted of martensite and nanometric precipitates), an intermediate thin layer (composed by austenite, martensite and oxides) and an external layer (constituted of oxides like hematite, magnetite and kamiokite). Chemical microanalysis indicated that the intermediate layer is richer in Ni and Co (austenite stabilizers). Besides identifying the different phases and chemical compositions through the material, from the surface to the bulk, it was possible to understand how austenite is formed during oxidation.

  • IPEN-DOC 28898

    COUTO, CAMILA P. ; BAERT, KITTY; COSTA, ISOLDA ; PANOSSIAN, ZEHBOUR; DE GRAEVE, IRIS; REVILLA, REYNIER I.; TERRYN, HERMAN; ROSSI, JESUALDO L. . Influence of hot-stamping process on the corrosion initiation and properties of corrosion products at the surface of 22MnB5 steel metallic coated with hot-dip Al-Si. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: 22MnB5 is an ultra-high strength steel combined with hot-stamping process, also known as press hardened steel (PHS). It is a strategic material for the automotive industry because it allows safety improvement, lightweight design and consequently reduction of fuel consumption. In order to prevent surface scale and steel decarburisation during the hot-stamping process, the material is often protected with metallic coatings. Hot-dip Al-Si (Si 10 % in mass fraction) is the most used system for hot-stamping application. This study has the objective to characterize the corrosion initiation and the properties of the corrosion products at the surface of samples before and after hot-stamping process. The samples were submitted to several cycles of accelerated corrosion tests in a salt spray chamber. A systematic characterization of the corroded surface was done by means of Raman spectroscopy and scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM - EDS). The samples were also immersed in a Cl– containing solution, after which the morphology of the corrosion attacks and the corrosion initiation process were studied. The thermo-mechanical process changes the corrosion mechanism as well as the nature of the corrosion products.

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

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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

ATENÇÃO!

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

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

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

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


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

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

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

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

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