Navegação IPEN por ano de publicação "2019"

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  • IPEN-DOC 25851

    BENEDETTO, RAQUEL ; MASSICANO, ADRIANA V.F.; CRENSHAW, BRYANT K.; OLIVEIRA, RENATO; REIS, RUI M.; ARAUJO, ELAINE B. ; LAPI, SUZANNE E.. Zr-89-DFO-cetuximab as a molecular imaging agent to identify cetuximab resistance in head and neck squamous cell carcinoma. Cancer Biotherapy and Radiopharmaceuticals, v. 34, n. 5, p. 288-296, 2019. DOI: 10.1089/cbr.2018.2616

    Abstract: Background: Despite the improvement in clinical outcomes for head and neck squamous cell carcinoma (HNSCC) as the result of cetuximab, patients may present with or develop resistance that increases tumor recurrence rates and limits clinical efficacy. Therefore, identifying those patients who are or become resistant is essential to tailor the best therapeutic approach. Materials and Methods: Cetuximab was conjugated to p-NCS-Bz-DFO and labeled with 89Zr. The resistance model was developed by treating FaDu cells with cetuximab. Western blotting (WB) and specific binding assays were performed to evaluate epidermal growth factor receptor (EGFR) expression and 89Zr-DFO-cetuximab uptake in FaDu cetuximab-resistant (FCR) and FaDu cetuximab-sensitive (FCS) cells. Positron emission tomography imaging and biodistribution were conducted in NU/NU nude mice implanted with FCR or FCS cells. Results: Cetuximab was successfully radiolabeled with 89Zr (‡95%). Binding assays performed in FCR and FCS cells showed significantly lower 89Zr-DFO-cetuximab uptake in FCR ( p < 0.0001). WB suggests that the resistance mechanism is associated with EGFR downregulation ( p = 0.038). This result is in agreement with the low uptake of 89Zr-DFO-cetuximab in FCR cells. Tumor uptake of 89Zr-DFO-cetuximab in FCR was significantly lower than FCS tumors ( p = 0.0340). Conclusions: In this work, the authors showed that 89Zr-DFO-cetuximab is suitable for identification of EGFR downregulation in vitro and in vivo. This radiopharmaceutical may be useful for monitoring resistance in HNSCC patients during cetuximab therapy.

    Palavras-Chave: zirconium 89; positron computed tomography; carcinomas; radiopharmaceuticals; therapy; chemotherapy; antibodies; reagents

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  • IPEN-DOC 26690

    BRAGA, ELISABETE S.; AZEVEDO, JULIANA S.; KUNIYOSHI, LEONARDO; FAVARO, DEBORAH I.T. . Zn, Co, Cr, As, and genotoxic effects in the ichthyofauna species from polluted and non-polluted/protected estuaries of the São Paulo coast, Brazil. Anais da Academia Brasileira de Ciências, v. 91, n. 4, p. 1-18, 2019. DOI: 10.1590/0001-3765201920190066

    Abstract: The human impact on estuarine regions results in an increasing concentration of trace elements in the environment, exposing aquatic organisms. In this study, Zn, Co, Cr, and As were determined in the muscle tissue of some fish species from Santos-São Vicente (SSV), a recognized polluted region, and in the Cananeia estuary (CAN). Genotoxicity was also determined for the evaluation of the chronic effect on ichthyofauna, to enlarge the bank of environmental data regarding the effects of pollution, and to suggest other fish bioindicator species that may contribute to monitoring programs. The obtained data showed a similar profile of an accumulation of Co and Zn in Micropogonias furnieri and Chaetodipterus faber, where: Santos Bay > CAN > inner area of SSV. A low frequency of micronucleus was observed. However, in general, fish from the inner area of the SSV estuary presented more nuclear abnormalities than fish from Santos Bay and CAN. In the inner area of SSV, Centropomus paralelus and Diapterus rhomneus showed more changes than other fish species. It was possible to consider that the habits of each species, contributed to a different profile of trace element accumulation, followed by the chemical components in the organism offering different vulnerability.

    Palavras-Chave: trace amounts; elements; erythrocytes; environmental impacts; resource conservation; environmental protection; aquatic ecosystems; estuaries; animal tissues; fishes; zinc; carbon monoxide; chromium; arsenic; brazil

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  • IPEN-DOC 26152

    LIMA, GEAN B. de ; KAISER, THIAGO J. S.; MOREIRA, EDSON G. . Z-score, a tool for quality assurance of analytical results in neutron activation analysis. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 478-485.

    Abstract: The Nuclear and Energy Research Institute (IPEN CNEN / SP), through the Research Reactor Center (CERPq), conducts several studies using Instrumental Neutron Activation Analysis (INAA) in its Activation Analysis Laboratory (LAN). The present study performed a critical analysis of the way Certified Reference Materials (CRM) are used to assess accuracy in LAN activities, from a statistical point of view. With the wide dissemination and application of metrological concepts, the use of regulatory standards (ABNT and INMETRO) became increasingly necessary. The literature defines several approaches to the statistical principles for the use of the obtained values. CRMs are used to assess the accuracy of analytical methods, being essential for trueness assessment. There are a few ways to quantify trueness, and this can be done by percent relative error and z score, determining the trend of the analytical method, which is defined as the estimation of a systematic error. The use of z scores is interesting in evaluating the quality of analytical methods, as it is less subject to the influence of the concentration value. Theses and dissertations developed at LAN were selected as the object of study and the calculations were performed using the concepts presented to verify the data treatment, at a 95% confidence level, presenting satisfactory results.

    Palavras-Chave: accuracy; calibration standards; data; data analysis; neutron activation analysis; quality assurance; statistical data; statistical models

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  • IPEN-DOC 26764

    FERREIRA, MERILYN S. ; PASK, HELEN M.; WETTER, NIKLAUS U. . Yellow laser at 573 nm generated by intracavity SHG diodeside-pumped Raman laser. In: ADVANCED SOLID STATE LASERS, September 29 - October 3, 2019, Vienna, Austria. Resumo expandido... Washington, DC, USA: OSA, 2019. (Laser Congress 2019 (ASSL, LAC, LS&C)).

    Abstract: A diode side-pumped Nd:YLiF4 crystal for fundamental wavelength generation and intracavity Stokes conversion in KGW are employed to obtained 6.1W maximum output power, 11.9% slope efficiency and 11.8% diode-to-yellow conversion efficiency at 573 nm.

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  • IPEN-DOC 26293

    CASTRO, DIONE P. de ; GARCIA, RAFAEL H.L. ; SILVA, LEONARDO G. de A. e . XRD characterization thermoplastic STARCH/poly (butylene adipate-co-terephthalate) (TPS/PBAT) blends irradiated by gamma rays. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 2591-2597.

    Abstract: The aim of this research was to check the changes in the structure and crystallinity of non-irradiated and irradiated thermoplastic starch blends (TPS)/poly (butylene adipate-co-terephthalate) - PBAT and also to evaluate the behavior of castor oil in place of glycerol. In this work, the characterization was performed by X-ray diffraction (XRD), in which the crystallinity index (IC) of non-irradiated and irradiated blends of TPS/PBAT was calculated. For plastification of the TPS, glycerol, castor oil and TWEEN® 80 were used to verify the compatibility and compare the blends with each other. The samples were prepared by extrusion and irradiated at 25 kGy with gamma rays from a 60Co source. However, the crystallinity indexes of the blends were altered according to the plasticizer used and the use of TWEEN® 80. Thus, it been concluded that glycerol substitution by castor oil is feasible in TPS/PBAT blends.

    Palavras-Chave: castor oil; cobalt 60; comparative evaluations; gamma radiation; glycerol; irradiation; mixing; plasticizers; starch; thermoplastics; x-ray diffraction

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  • IPEN-DOC 25850

    FRIMAIO, AUDREW ; NASCIMENTO, BRUNA C.; BARRIO, RAMON M.M.; CAMPOS, LETICIA L. ; COSTA, PAULO R.. X-ray spectrometry applied for determination of linear attenuation coefficient of tissue-equivalent materials. Radiation Physics and Chemistry, v. 160, p. 89-95, 2019. DOI: 10.1016/j.radphyschem.2019.03.021

    Observação: Reprint anexado. Radiation Physics and Chemistry, v. 167, 2020. DOI: 10.1016/j.radphyschem.2019.108553

    Abstract: Resin-based materials equivalent to water were developed and four different samples were obtained. The linear attenuation coefficients of all samples was evaluated using X-ray spectrometry with primary and transmitted beams using voltages at the ranging from 60 to 120 kV. The experimental measured values were compared with theoretical reference values to water and with that obtained using the Least Square Method algorithm methodology (method applied to diagnostic radiology and radiotherapy). Our results show that differences between the measured values and the target μ(E) was lower than 7% ± 0.3 in the energy range from 20 to 80 keV. These results enable to consider that the material developed and produced is a good option to be used as a waterequivalent material and the experimental method adequate to its quantitative evaluation.

    Palavras-Chave: phantoms; x-ray tubes; tissue-equivalent materials; attenuation; spectroscopy; samplers; resins

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  • IPEN-DOC 25849

    BARROSO, A.G.; GARCIA, R.H.L. ; DEL MASTRO, N.L. . X-ray diffraction pattern and relative crystallinity of irradiated arrowroot starch. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-7, 2019. DOI: 10.15392/bjrs.v7i2A.645

    Abstract: After cereals, tubers and roots are the major source of starch for food and industrial uses. Arrowroot refers to any plant of the genus Marantha, but the term is most commonly used to describe the easily digested starch ob-tained from the rhizomes of Marantha arundinacae. The rhizomes of this herbaceous plant contain about 20% of starch. As few studies exist on arrowroot starch, the objective of this preliminary work was to study the X-ray diffraction (XRD) patterns of arrowroot starch when treated by γ-radiation with doses up to 15 kGy in a 60Co source. The XRD patterns of the arrowroot starch exhibited A-type crystalline arrangements with strong peaks at approximately 15º, 17º, 18º and 23º (2θ). A slight increase of diffractogram peaks intensity was noticed after the irradiation process. The cristallinity index was calculated using Bruker DIFFRAC.EVA version 4.2 software. Relative crystallinity seems to increase with irradiation at low doses that could be attributed to different radia-tion sensitivity among the amorphous and crystalline regions of the arrowroot starch molecule. Present results will contribute to elucidate the behavior under radiation treatment of this starchy component increasingly em-ployed by the food industry.

    Palavras-Chave: x-ray diffraction; gamma radiation; starch; radiation effects; radiation doses; cobalt 60; crystal structure; irradiation

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  • IPEN-DOC 26529

    CARDOSO, QUEZIA de A. ; CASINI, JULIO C.S.; BARBOSA, LUZINETE P. ; SERNA, MARILENE M. ; GALEGO, EGUIBERTO ; SOBRINHO, LUIZA F. ; SAKATA, SOLANGE K. ; FARIA JUNIOR, RUBENS N. de . X-ray diffraction evaluation of the average number of layers in thermal reduced graphene powder for supercapacitor nanomaterial. Materials Science Forum, v. 958, p. 117-122, 2019. DOI: 10.4028/www.scientific.net/MSF.958.117

    Abstract: Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. In this work, the thermal reduction of GO powder has been carried out using back pumping vacuum pressures and investigated employing X-ray diffraction analysis. The experimental results of estimating the number of graphene layers on the reduced powder at various temperatures (200 – 1000 °C) have been reported. Electrical changes have been produced in a graphene oxide with the vacuum reduction process. This study has shown that the ideal processing temperature for reducing graphene oxide nanomaterial was about 400 oC. It has also been shown that at 600 oC the number of layers in the reduced nanomaterial increased. The internal series equivalent resistance (ESR) has been improved substantially with the vacuum thermal treatment even at temperatures above 400 oC. ESR was reduced from 95.0 to about 13.8 Ω cm2 with this processing. These results showed that the process can be applied to the reduction of graphene oxide to produce supercapacitor nanomaterials. The advantage of employing this method is that the processing is a straightforward and low cost thermal treatment that might be used for large amount of nanocomposite material.

    Palavras-Chave: graphene; oxides; x-ray diffraction; vacuum systems; capacitors; capacitive energy storage equipment; nanomaterials; electrical properties

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  • IPEN-DOC 25848

    ICHIKAWA, R.U. ; LINHARES, H.M.S.M.D.; SILVA, A.S.B. da ; TEIXEIRA, M.I. ; RANIERI, I.M. ; TURRILLAS, X.; MARTINEZ, L.G. . X-ray diffraction analysis of KY3F10 nanoparticles doped with Nd and preliminary studies for its use in high-dose radiation dosimetry. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i2A.586

    Abstract: In this work, the structure and microstructure of Nd:KY3F10 nanoparticles was probed using X-ray synchrotron diffraction analysis. Rietveld refinement was applied to obtain cell parameters, atomic positions and atomic dis-placement factors to be compared with the ones found in literature. X-ray line profile methods were applied to determine mean crystallite size and crystallite size distribution. Thermoluminescent (TL) emission curves were measured for different radiation doses, from 0.10 kGy up to 10.0 kGy. Dose-response curves were obtained by area integration beneath the peaks from TL. The reproducibility of the results in this work has shown that this material can be considered a good dosimetric material.

    Palavras-Chave: nanoparticles; x-ray diffraction; radiation doses; doped materials; thermoluminescence; neodymium; yttrium fluorides; critical size; dose-response relationships; dosimetry

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  • IPEN-DOC 26451

    MACHADO, JOÃO P.S.L.; JELINEK, ANDREA R.; BICCA, MARCOS M.; STEPHENSON, RANDELL; GENEZINI, FREDERICO A. . West Gondwana orogenies and Pangaea break-up: thermotectonic effects on the southernmost Mantiqueira Province, Brazil. Journal of the Geological Society, v. 176, n. 6, p. 1056-1075, 2019. DOI: 10.1144/jgs2019-018

    Abstract: Through the joint use of apatite fission tracks (AFT) and (U–Th)/He analysis in apatite (AHe) and zircon (ZHe), we evaluate the thermotectonic evolution of the Sul-Rio-Grandense Shield (SRGS), southernmost Mantiqueira Province, Brazil. Formed during the assembly of West Gondwana (Neoproterozoic), the shield comprises four tectonostratigraphic terranes separated by regional faults and shear zones. The central and eastern terranes present Mesozoic AFT ages, whereas the western terrane ages are mostly late Paleozoic. AHe ages show considerable dispersion, although most are Mesozoic. ZHe ages from the east are early Permian, whereas the west presents Devonian ages. Inverse thermal modelling indicates a Devonian to Carboniferous cooling phase in the west, time correlated with orogenies occurring at the SW margin of Gondwana, which affected the regional geodynamics and are possibly linked to limited uplift of the shield. From the Permian to Jurassic a major cooling phase took place in the SRGS, probably related to lithosphere thinning and uplift preceding the South Atlantic rifting. Samples closer to the Atlantic coast suggest a subtle reheating after this event, provisionally linked to a geothermal disturbance related to ocean opening and associated magmatism. A final post-Paleocene cooling phase towards surface conditions affected the entire SRGS.

    Palavras-Chave: geologic history; tectonics; age estimation; earth crust; fission tracks; sedimentary basins; apatites; zircon; temperature dependence; brazil; thermal analysis

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  • IPEN-DOC 25847

    ANDRADE, ADRIANO B.; BISPO, GIORDANO F. da C.; MACEDO, ZELIA S.; BALDOCHI, SONIA L. ; YUKIHARA, EDUARDO G.; VALERIO, MARIO E.G.. VUV excited luminescence and thermoluminescence investigation on Er3+- or Pr3+-doped BaY2F8 single crystals. Optical Materials, v. 90, p. 238-243, 2019. DOI: 10.1016/j.optmat.2019.02.044

    Abstract: Photoluminescence (PL), thermoluminescence (TL) emission spectra and TL glow curves of barium yttrium fluoride (BaY2F8 – BaYF), undoped and doped with erbium (Er3+) or praseodymium (Pr3+) were measured to investigate the fundamental absorption (band gap – Eg), the nature of the trapping centers, as well as the electronic transitions of Ln3+ in BaYF host. The band gap energy Eg of BaY2F8 was determined by vacuum ultraviolet (VUV) excitation measurements to be around 11.2 eV. Additionally, the electronic transition from excited states of Ln3+ ions and the exciton state were also identified. TL emission spectra showed that the TL emission of doped samples is related to the Ln3+ ion, indicating that the related host trapping centers are not affected by the new trapping centers originated due the dopant ions. Trap depths were calculated by fitting the glow curves using a first order kinetics model. Host-related trapping centers were attributed to intrinsic defects such as Vk and F centers and the new TL peaks observed for Ere and Pr-doped samples was associated to the electrons trapping centers. These results lead us to propose a simple model to explain the origin of the TL emission in BaYF.

    Palavras-Chave: ultraviolet spectra; spectroscopy; barium fluorides; yttrium fluorides; thermoluminescence; photoluminescence; emission spectra; monocrystals

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  • IPEN-DOC 26689

    SAMPAIO, CAMILA S.; ARIAS, JESSICA F.; ATRIA, PABLO J.; CACERES, EDUARDO; DIAZ, CAROLINA P.; FREITAS, ANDERSON Z. ; HIRATA, RONALDO. Volumetric polymerization shrinkage and its comparison to internal adaptation in bulk fill and conventional composites: A μCT and OCT in vitroanalysis. Dental Materials, v. 35, n. 11, p. 1568-1575, 2019. DOI: 10.1016/j.dental.2019.07.025

    Abstract: Objective. To quantify the volumetric polymerization shrinkage (VPS) of different conventional and bulk fill resin composites, through micro-computed tomography (μCT), and qualitative comparison of gap formation through optical coherence tomography (OCT). Methods. Box-shaped class I cavities were prepared in 30 third-molars and divided into 5 groups (n = 6): G1- Filtek Z100 (Z100); G2- Tetric Evoceram Bulk Fill (TEC); G3- Tetric EvoFlow Bulk fill (TEF); G4- Filtek Bulk fill (FBU); and G5- Filtek Bulk fill Flowable (FBF). All groups were treated with Adper Single Bond Plus adhesive and light cured (Bluephase 20i). Each tooth was scanned three times using a μCT apparatus: after cavity preparation (empty scan); after cavity filling (uncured scan) and after light curing of the restorations (cured scan). The μCT images were imported into a three-dimensional rendering software, and volumetric polymerization shrinkage percentage was calculated (%) for each sample. In the same images, interfacial gaps in the pulpal floor were qualitatively evaluated. After μCT evaluation, the pulpal floor from each tooth was polished until a thin tooth structure was obtained and OCT images were obtained by scanning the pulpal portion. Gap formation was observed and qualitatively compared to the μCT images.

    Palavras-Chave: polymerization; shrinkage; volumetric analysis; computerized tomography; optical systems; optical modes; light coherence; resins; composite materials; biological recovery

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  • IPEN-DOC 26688

    BARCESSAT, ANA R. ; GURGEL-JUAREZ, NALIA C.; WETTER, NIKLAUS U. . Vital tooth bleaching using different techniques: a clinical evaluation. Future Dental Journal, v. xxx, n. xxx, p. xxx-xxx, 2019. DOI: 10.1016/j.fdj.2018.11.003

    Abstract: Objectives: This clinical trial aimed to evaluate dental color stabilization after different bleaching techniques. Methods: Four dental bleaching techniques were tested in 60 healthy volunteers aged from 25 to 35 years randomly assigned to four groups. Group 1 (G1): conventional in-office bleaching using 35% hydrogen peroxide. Group 2 (G2): in-office application of 3% hydrogen peroxide followed by in-office bleaching using 35% hydrogen peroxide. Group 3 (G3): in-office application of 3% hydrogen peroxide and activation with a light emitting diode (LED) lamp. Group 4 (G4): at-home bleaching using 10% carbamide peroxide. The color of canines and incisors was scored using a digital spectrophotometer to analyze lightness, chroma and hue. Results: All groups resulted in shade change. Lightness increased in all groups with no statistical difference among groups 60 days after finishing the treatment regardless of the technique used (p > 0.05). Differences were found in a short-term evaluation between some groups (p < 0.05). Chroma showed no statistical differences for central incisors after bleaching (p > 0.05). Analyzing canines, G4 showed higher chroma compared to G1 (p < 0.05) and G2 (p < 0.05). For hue, only G2 behaved differently for canines and incisors (p < 0.05). In other groups, hue scores decreased after bleaching. Conclusions: All techniques improved lightness. The addition of 3% hydrogen peroxide to conventional in-office whitening only increased appointment time, but no further benefits were noticed. Clinical relevance: This study is important to help clinicians deciding which is the most suitable dental bleaching for each patient in the current high aesthetic demanding world.

    Palavras-Chave: bleaching; dentistry; teeth; spectrophotometry; peroxides; aesthetics; color; hydrogen peroxide

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  • IPEN-DOC 26054

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

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  • IPEN-DOC 26352

    SILVA, LEANDRO G.M. e ; SABUNDJIAN, GAIANE . Virtual visit to nuclear research reactor IEA-R1. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 4839-4846.

    Abstract: The aim of this paper is to provide students, educators, and the general public with a virtual tool for learning about the peaceful use of nuclear technology and its importance to humanity. Using new technologies available in the market such as smartphones, software for the development of electronic games, virtual reality glasses, among others, we will virtually reproduce the facilities of the IEA-R1 nuclear research reactor, allowing anyone to perform a virtual and interactive visit to these facilities in a safe and didactic way. The use of virtual reality glasses and applications has been shown to be adequate in relation to the objectives proposed here.

    Palavras-Chave: computer codes; computerized simulation; data visualization; educational tools; iear-1 reactor; mobile phones; real time systems; training

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  • IPEN-DOC 26353

    PALADINO, PATRICIA A. ; SABUNDJIAN, GAIANE ; CABRAL, EDUARDO L.L. ; JULIÃO, ARTHUR P.. Virtual Reality tools for goods, food and beverage irradiation at IPEN's facilities as a nuclear technology teaching motivation. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 4855-4863.

    Abstract: In this research a full-fledged and complete Virtual Reality (VR) environment will be wholly developed and then deployed as a kind of innovative means of widespread divulgation of one topic of nuclear science and nuclear technology most interesting application and its teaching; viz, that related to goods, beverages and mainly food irradiation practices, simulating a virtually guided visit to some of IPEN’s facilities and its already installed and operational scientific equipment, namely, the GAMMACELL irradiator, firstly targeting undergraduate and last year high school students and then, later, the interested general public. In this way, several programs and whole VR platforms, such as Unity, are used as powerful, professional tools for games and videogames development and it is expected that the final product will be made available packaged as an instructive videogame to the community of committed and interested users. Therefore, in doing so, some contemporary reasoned and still debated pedagogical recommendations will be handled and met, hopefully increasing students’ curiosity and good aptitudes towards the disseminated use of nuclear technologies nowadays. It is hoped that perhaps a modest contribution against the many undeserved prejudices and odd misconceptions still remaining nowadays regarding nuclear science development, results and applications, will be abated.

    Palavras-Chave: computerized simulation; education; educational tools; food processing; ionizing radiations; radiators; real time systems; video files; brazilian cnen

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  • IPEN-DOC 27100

    CARVALHO, ELIAS F. ; OSTERMANN, CAROLINE K. ; BUSTILLOS, JOSE O.V. . Vertical profile analysis of wind flow to obtain optimal eddy covariance parameters. In: ATTO WORKSHOP, 3rd, September 16-20, 2019, Manaus, AM. Poster... 2019.

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  • IPEN-DOC 25846

    SOUZA, C.H. ; SHORTO, J.M.B. ; SIQUEIRA, P.T.D. ; NUNES, M.G. ; SILVA JUNIOR, I.A. ; YORIYAZ, H. . Verification of angular dependence in MOSFET detector. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-11, 2019. DOI: 10.15392/bjrs.v7i2A.734

    Abstract: In vivo dosimetry is an essential tool for quality assurance programs, being a procedure commonly performed with thermoluminescent dosimeters (TLDs) or diodes. However, a type of dosimeter that has increasing popularity in recent years is the metal-oxide-semiconductor field effect transistor (MOSFET) detector. MOSFET dosimeters fulfill all the necessary characteristics to realize in vivo dosimetry since it has a small size, good precision and feasibility of meas-urement, as well as easy handling. Nevertheless, its true differential is to allow reading of dose in real time, enabling immediate intervention in the correction of physical parameters deviations and anticipation of small anatomical changes in the patient during treatment. In order for MOSFET dosimeter to be better accepted in clinical routine, information reporting performance should be available frequently. For this reason, this work proposes to verify reproducibility and angular dependence of a standard sensitivity MOSFET dosimeter (TN-502RD-H) for Cs-137 and Co-60 sources. Exper-imental data were satisfactory and MOSFET dosimeter presented a reproducibility of 3.3% and 2.7% (±1 SD) for Cs-137 and Co-60 sources, respectively. In addition, an angular dependence of up to 6.1% and 16.3% for both radioactive sources, respectively. It is conclusive that MOSFET dosimeter TN-502RD-H has satisfactory reproducibility and a considerable angular dependence, mainly for the Co-60 source. This means that although precise measurements, special attention must be taken for applications in certain anatomical regions in a patient.

    Palavras-Chave: mosfet; experimental data; dosemeters; dosimetry; in vivo; performance; cesium 137; cobalt 60; irradiation; neoplasms

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  • IPEN-DOC 25845

    CARVALHO, P.R. ; MUNITA, C.S. ; LAPOLLI, A.L. . Validity studies among hierarchical methods of cluster analysis using cophenetic correlation coefficient. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-14, 2019. DOI: 10.15392/bjrs.v7i2A.668

    Abstract: The literature presents many methods to produce data set clusters and the better method choice becomes hardest because the various combinations between them based on different dissimilarity measures can lead to different cluster patterns and false interpretations. Nevertheless, little effort has been expended in evaluating these methods empirically using an archeological data set. In this way, this work has the objective to develop a comparative study of the cluster analysis methods and to identify what is the most appropriate for an archeological data set. For this, 45 ceramic fragments samples data set was analyzed by instrumental neutron activation analysis (INAA). And, five hierarchical methods of cluster were used to this data set: Single linkage, Complete linkage, Average linkage, Centroid and Ward. The validation was done calculating cophenetic correlation coefficient values by a statistical program R and the comparison between them showed the average linkage method was more accurate for the 45 ceramic fragments samples data set. With this, the statistical program R showed be an tool option for other scientists to calculate their cophenetic correlation coefficient and to identify the more accurate methods for their archeological data set.

    Palavras-Chave: validation; neutron activation analysis; archaeology; quality control; comparative evaluations; ceramics; multivariate analysis; cluster analysis; elements

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  • IPEN-DOC 26375

    BELCHIOR JUNIOR, ANTONIO ; SOARES, HUMBERTO V.; FREITAS, ROBERTO L.. Validation of the RELAP5 code for the simulation of the Siphon Break effect in pool type research reactors. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 5383-5392.

    Abstract: In an open pool type reactor, the pool water inventory should act as a heat sink to provide emergency reactor core cooling. In the Brazilian Multipurpose Reactor – RMB, to avoid the loss of pool water inventory, all the Core Cooling System (CCS) lines penetrate at the pool top, far above the reactor core level. However, as most of CCS equipment and lines are located below the reactor core level, in the case of a Loss of Coolant Accident (LOCA), a large amount of pool water could be lost drained by siphon effect. To avoid RMB research reactor core discovering in the case of a LOCA, siphon breakers, that allow CCS line air intake, are installed in the CCS lines in order to stop the reactor pool draining due to siphon effect. As siphon breakers are important passive safety devices, their effectiveness should be verified. Several previous numerical and experimental studies about siphon break effect were found in the literature. Some of them comment about the effectiveness of the siphon breakers based on their air intake area. Others state that one-dimensional thermo-hydraulic system codes such as RELAP5 code would fail when modeling the siphon break effect. This work shows the RELAP5/MOD3.3 code capability in modeling the siphon break effect. A nodalization for RELAP5/MOD3.3 code of a Siphon Breaker Test Facility located at POSTECH University in Korea was developed. Experiments considering several siphon breakers device intake areas were simulated. A very good agreement between numerical and experimental results was obtained. As siphon breakers intake areas decrease, the siphon breaker effectiveness also decreases and more water is drained from the reactor pool. For smaller siphon breaker intake areas, RELAP5/MOD3.3 code showed conservative results, overestimating the reactor pool water losses.

    Palavras-Chave: computerized simulation; loss of coolant; pipes; pool type reactors; r codes; reactor cores; ruptures; safety analysis; tanks; test facilities; test facilities; validation; void fraction

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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.