REPOSITÓRIO DIGITAL DA PRODUÇÃO TÉCNICO CIENTÍFICA

 

 

 

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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. [Saiba mais]

 

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  • IPEN-DOC 26817

    FEDERICO, CLAUDIO A.; GONÇALEZ, ODAIR L.; PAZIANOTTO, MAURICIO T.; DIAS, ARTHUR F.; PRADO, ADRIANE C.M.; CALDAS, LINDA V.E. . A statistical evaluation on the cosmic radiation doses on aircrews flying over South America and Caribbean regions. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction There are substantial researches on the cosmic radiation doses received by aircrew on their typical fl ight workload. Most part of these studies was made by measurements onboard aircrafts of some specifi c companies in stablished routes. A recurrent question from countries over South America and Caribbean regions is related on the signifi cance of doses accumulated by aircrews over this region and if those magnitude justifi es a specifi c radiation protection procedure. Methods The evaluation was made by statistical analysis using CARI-6 aircrew radiation dose code and the data are derived from comprehensive records of registered fl ights performed in the South America and Caribbean airspace between 29,000 and 41,000 feet, performed from March 7 to 20, 2009. The analysis of this sample was composed of 80,548 route calculations totalizing 53,163 hours of real fl ights, by means of calculation of each track performed by aircrafts between aeronautic navigation waypoints. Results The analysis identifi es that the typical group of fl ight crew operating over this region receives mean dose rates ranging from 2.65 μSv/h to 2.95 μSv/h depending on the solar cycle. This distribution, integrated over typical workload from Brazilian aircrews results on annual doses ranging from 1.45 mSv to 1.67 mSv. Conclusions The results demonstrate that the typical aircrew fl ying over this region exceeds the annual radiation limit for public (1 mSv). The statistical analysis also shows that this is the case of more than 96% of the aircrew fl ying with this fl ight routine and workload. The presented results can be used by local authorities of countries over this region as a basis to evaluate the convenience on adoption the recommendation from ICRP Publication 132 regarding radiation protection recommendations for aircrews.

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  • IPEN-DOC 26816

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; ANDREETA, MARCELLO R.B.; YAMAGUSHI, YASMIM Y.; JIUSTI, JEANINI; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Evaluation of the FTIR technique for the linearity assessment of commercial soda-lime glass irradiated with gamma radiation. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction High dose dosimetry is one of the most important branches of everyday activities related to medical and industrial applications. Nevertheless, the use of materials that respond in a linear manner has advantages over nonlinear materials, since the dose calculation procedure in linear materials relies solely upon direct proportions to the delivered dose. The evaluation techniques are also important to identify the possible linear ranges, and the new Fourier-transform infrared spectroscopy (FTIR) technique has been used to this objective. This work aims to investigate the linearity response and its sensitivity, using mainly the FTIR technique. Methods Cubic samples of a soda-lime glass type with composition of Li2O.2B2O3 + 10 mol% of (0.25Li2O + 0.25La2O3 + TiO2) were irradiated with doses from 1 kGy to 12 kGy, using a 60Co Gamma-Cell system 220. The response was evaluated using the FTIR technique. Results The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR), with its loadings performing a linear regression; from the slope value, the sensitivity of the glass at the absorbed dose range was obtained. The PLSR technique showed, on the range of 1-12 kGy, that the soda-lime glass type presents linearity value of 0.8532 using just three components. The results of the linearity test were obtained for the FTIR technique. Conclusions The FTIR technique was applied to assess the linear behavior based of the glass spectrum, showing its usefulness to identify possible linear dose regions and also the overall sensitivity of the glass samples to dose. Therefore, the results obtained indicate a good linear response, showing therefore a potential use of this glass-soda lime type for radiation dosimetry in high doses.

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  • IPEN-DOC 26815

    PRADO, EDUARDO S.P. ; GONÇALVES, MAX F.S.; MIRANDA, FELIPE de S.; PETRACONI FILHO, GILBERTO; MASSI, MARCOS; POTIENS JUNIOR, ADEMAR J. . Plasma reactor to viabilize the volumetric reduction of radioactive wastes. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction According of the International Atomic Energy Agency – IAEA, nuclear waste, also known as, radioactive waste, is any material containing a higher concentration of radionuclides than those considered safe by the national authorities. In Brazil, there is a National Nuclear Energy Commission to regulate. These wastes can be generated in nuclear power plants, industries, hospitals and research institutes. To permanently dispose of these radioactive wastes of low and medium level of radioactivity safely and cost effectively, these should be transformed into the physical and chemical compounds suitable for radionuclides immobilization with maximum volume and exhaust gaseous reduction. Incineration is used as a treatment for a very wide range of wastes. Incineration itself is commonly only one part of a complex waste treatment system that altogether, provides for the overall management of the broad range of wastes that arise in society. The objective of waste incineration, in common with most waste treatments, is to treat waste so as to reduce its volume and hazard, whilst capturing (and thus concentrating) or destroying potentially harmful substances. The incineration of waste is one of the most widespread and effective technologies allowing considerably to reduce waste volume. In this scope, among the promising technologies for the radioactive waste treatment is the plasma technology that allows reducing substantially the waste volume after exposing them to temperatures above 2500ºC. In the planning and management of radioactive waste, the challenges related to plasma technology are presented as a motivation factor for the possible implantation of plasma reactors in nuclear plants and research centers with the objective of improving the process of radioactive waste treatment. In this way, this work aims to evaluate the use of plasma technology for the incineration of radioactive waste for volumetric reduction and immobilization of this waste. Methods In this work, a plasma reactor was used for waste incineration, and all reactor parameters (electric energy ranges, maximum arc current, maximum working voltage, air fl ow, maximum energy conversion effi ciency, average temperature of heated gas, heated enthalpy) was controlled based on literature. The experiment was carried out in the plasma reactor (laboratory scale) of LPP in the ITA, using plasma torch transferred arc and with gaseous argon oxidizing agent. The electrical and thermal characteristics of the auxiliary systems of the plasma reactor were obtained using transducers and thermocouples. The composition of the gases in the process was analyzed using mass spectrometer and spectrophotometer. Results The accuracy of the data was important to ensure good results in the process, which allowed the extraction of relevant information from the experiments performed. The volumetric reduction reached 92% in relation to the sample before being processed, with a peak temperature of 1800ºC. Although a larger amount of argon fl ow intensify the cooling of the inner wall of the reactor, and further promote the dilution of the plasma, the arc voltage increases, resulting in higher power operation. Conclusions In the present work a high effi ciency thermal transfer torch was characterized , able to validate the use of the plasma jet for the treatment of radioactive waste.

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  • IPEN-DOC 26814

    MATSUSHIMA, L.C.; VENEZIANI, G.R. ; SAKURABA, R.K.; CAMPOS, L.L. . Quality control in “Intensity Modulated Radiation Therapy-IMRT” using thermoluminescent dosimeters. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Quality assurance in radiation therapy included all actions for ensure the maximum dose for the target volume (tumour) and minimum dose for the healthy tissues. The use of thermoluminescent detectors for evaluation of the absorbed doses in treatments that involve the use of ionizing radiation is widespread and well established in clinical routine. The quality measures are employed to validate system performance, such as IMRT quality assurance (QA). An example for IMRT QA is the decision not to treat the patient if the comparison between a point-dose measurement and the planned value exceeds a predefi ned acceptance criterion (±5%). This work aimed the evaluation of absorbed doses with the use of thermoluminescent detectors (TLDs) of lithium fl uoride doped with magnesium and titanium (LiF:Mg,Ti) and a polymethylmethacrylate (PMMA) phantom in Intensity Modulated Radiation Therapy – IMRT planning. Methods In this study the PMMA phantom simulated a patient in treatment. The central cavity (rectangular format) was considered like target volume (tumour) and the others four cavities were considered like organs at risk. The TLDs were positioned inside the cavities; each cavity has an EVA mold for the positioning of TLDs.

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  • IPEN-DOC 26813

    CORREA, J.N.; PASCHUK, S.A.; BARRETO, R.C.; DENYAK, V.; SCHELIN, H.R.; NARLOCH, D.C.; DEL CLARO, F.; HASHIMOTO, Y.; MATIN, A.C.; SILVA, A.C.M.; ZAHN, G.S. ; SILVA, P.S.C. . Evaluation of the maximum emitting layer of Rn-222 in cementitious building materials. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction – Radionuclides present in construction materials are of interest in the view of environmental radioactivity. The limitations established have focused on the concentration of Ra-226 and the consequent exhalation of Rn-222. A physical/mathematical model developed at the Laboratory of Applied Nuclear Physics (LFNA/UTFPR) correlates the exhaled Rn-222 with the Ra-226 inherent to the material. The model considers the exhalation of Rn-222 by a plane surface that simulates exhalation in fl oors, walls and ceilings. Determination of the maximum emitting layer of Rn-222 that effectively exhales is important to support the model. The objective of this research is to determine the maximum emissive layer of Rn-222 that provides internal diffusion and exhalation of radon-222 in cementitious materials. Methods - Cylindrical samples were made of common cement paste and cement paste with sand of high Ra-226 concentration. The samples (thicknesses 1 to 5 cm) were sealed in order to ensure the exhalation of Rn-222 through one surface. Samples and diffusion chambers containing CR-39 solid-state detectors were inserted into a glass vessel. The samples/detectors were stored for 30 days. Subsequently, the detectors were chemically etched and the nuclear tracks in the CR-39 detectors were counted. Results – For each type of sample a curve was fi tted whose threshold indicated the maximum emitting layer. The results obtained on the samples of common cement paste indicated a maximum emitting layer of 2cm. For samples of cement paste with sand with high Ra-226 concentration, no threshold was observed, indicating that the maximum emitting layer is greater than 5cm. Conclusions - The maximum emitting layer thickness of Rn-222 of common materials determined by curve fi tting was 2cm. For materials with high concentration of Ra-226 there is an indication that the emitter layer is larger than 5cm. The obtained results subsidize the physical/mathematical model developed in the LFNA/UTFPR.

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  • IPEN-DOC 26812

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; MORAIS JUNIOR, PEDRO A.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Dosimetric characterization of high-linearity bone radiation detector exposed to gamma-rays. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction In radiation physics, the study of new alternative dosimeters is of interest on the growing branch of dosimetric characterization of solid-state dosimeters for radiotherapy applications in the Medical Physics fi elds. There are innumerous emerging techniques for reading and processing multivariate data to assess the possible linear behavior of dosimeters; such methods are the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component Regression (PCR) techniques. The goal of this work was to expose bone samples to high doses and to use the FTIR spectrophotometry technique to evaluate the sensitivity and linearity of the absorbed profi les using PLSR and PCR analyses. Methods Small cubes with size approximately of 0.5 cm3 composed the bone samples, used in this work. The samples were irradiated in triplicates, with absorbed doses of 10, 100, 250, 400 and 500 Gy using a 60Co Gamma Cell-220 system (dose rate of 1.089 kGy/h); afterwards, the absorbance spectrum of each sample was acquired on a Fourier Transform Infrared (FTIR) Spectrometer (Frontier/Perkin Elmer) with an optical step of 1 nm from 400 nm to 4000 nm. Results The absorbance for high sensitivity peaks was observed for each bone sample, at the 552 nm, 991 nm and 1650 nm wavelengths in decreasing magnitude. The PLSR and PCR techniques showed, on the range from 10 Gy to 500 Gy, for the calibration curves of the system, a linearity of 0.9432 and 0.9422 respectively, using just three components on both methods. Conclusions The results indicate an acceptable linear response, and therefore this material may be an interesting radiation detector.

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  • IPEN-DOC 26811

    VILLANI, D. ; RODRIGUES JUNIOR, O. ; DANTAS, B.M.; CAMPOS, L.L. . Dosimetric characterization of 3D printed phantoms at different infill percentage for diagnostic x-ray energy range. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction The use of 3D printing and fi laments commonly found commercially for development of phantoms has been investigated in recent years due to the cost of materials and improvements in the quality of printers. The application of this technique for radiation protection and dosimetry requires a complex study of the quality control and the interaction of printed materials with different radiation beams. The aim of this paper is to characterize 3D printed phantoms and printing set-ups for different infi ll percentages for diagnostic energy beams. Methods 3D printing performance was studied using the RAISE 3D PRO2 printer from IPEN for printing with PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene) fi laments. Printing characteristics such as repeatability, reproducibility, effective density by displaced water mass and porosity at 100% infi ll were studied. Plate samples of 8x8x1cm3 were printed and, using the Pantak Seifert irradiator with different x-ray qualities in the diagnostic energy range, the attenuation coeffi cients were obtained experimentally for different percentages of plates infi ll. Results By printing three identical samples for each print mode, the 3D printing system had a repeatability better than 1.0% for masses and average of 0.7% for the dimensions of the printed objects, obtaining the highest variations in small printed parts. Little to no porosity has been found on the printed pieces with 100% infi ll, giving to the printed objects the same density of the chosen fi lament. The attenuation coeffi cients were determined for the different beam qualities and it was verifi ed that the variation in the values decreases as the infi ll quality increases. Conclusions The results show that the printing system have excellent repeatability and print quality. The different printing modes characterized together with their attenuation coeffi cients for the x-ray beams will be studied and used in the development of new 3D printed phantoms in our institute.

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  • IPEN-DOC 26810

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Evaluation of transparent and black commercial soda-lime glass irradiated with gamma radiation. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction The linearity characteristic in radiation dosimetry presents a growing interest. Glasses have been applied to radiation high doses. The goal of this work was to expose transparent and dark commercial soda-lime glasses samples to high doses and to use the UV-Vis spectrophotometry technique for their evaluation. Methods Transparent and dark commercial soda-lime glasses with dimensions of 1 x 10 x 40 mm3 were irradiated with doses from 1 kGy to 10 kGy using a 60Co Gamma-Cell system 220, and then were evaluated with the UV-Vis technique. The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component Regression (PCR) techniques. Results The PLSR and PCR techniques showed, on the range of 1-10 kGy, for the calibration curves, of transparent and black commercial soda-lime glass, linearity values of 0.9432 and 0.9422 respectively using just three components on both methods. The spectra present a baseline variation (and maximum absorbance values) proportional to the absorbed dose received by the samples. These results show that it is possible to use the technique of UV-Vis to determine if the glass samples were irradiated or not. The color changes for transparent glass irradiated with absorbed doses from 1 kGy up to 10 kGy. This color variation in relation to absorbed dose indicates that the glasses may be used as YES/NO dosimeters. Conclusions The UV-Vis measurements may be useful in gamma radiation dosimetry, using the spectra of irradiated glasses; the highest linearity was shown in order respectively for transparent and black commercial soda-lime glass; the glass samples changed their coloration proportional to the absorbed doses, and they may be used as Yes/No detectors and as high-dose dosimeters. The results indicate a good linear response and the radiation detectors present potential use for radiation dosimetry in high doses.

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  • IPEN-DOC 26809

    GONCALVES, J.A.C. ; MANGIAROTTI, A.; ASFORA, V.K.; KHOURY, H.J.; BUENO, C.C. . Dosimetric characterization of thin diodes in an electron beam facility for radiation processing. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction: Silicon diodes have been employed as relative dosimeters in clinical photon and electron beams. However, they are prone to radiation damage that produces a drop of their current sensitivities with increasing accumulated doses. This effect is attributed to the decrease of the minority carrier diffusion lengths which diminishes the sensitive volume of the diode. Theoretically, it is possible to mitigate the decay of the current sensitivity by choosing diodes with thicknesses smaller than the lowest minority carrier diffusion lengths anticipated for the foreseen accumulated dose. This surmise has been followed up in this work by evaluating the response of thin diodes (SFH00206K) for the dosimetry of electron beams used in radiation processing. Methods: The diode with 10 μm of depletion layer at 0V was produced on n type Si wafers of 220 m thickness. As a dosimeter, the device was housed in a probe and connected to an electrometer to be operated in short-circuit current mode without bias voltage. To carry out the irradiation, the probe was placed on a conveyor belt that crosses the radiation fi eld of a 1.5 MeV electron beam. Results: The currents were registered as a function of the exposure time for dose-rates within 2-8 kGy/s and accumulated doses up to 350 kGy. The dosimeter was characterized with respect to the linearity between current and dose-rate, repeatability and reproducibility of the current signals. Its lifespan was investigated, particularly addressing the stability of the current sensitivity factor with increasing absorbed doses. The measurements were benchmarked against calculations of the current taking into account the fraction of the electron energy deposited in the active volume of the diode, the dose-rate, and the values of diffusion lengths. Conclusion: All experimental data so far obtained prove that this diode can be used in electron beam dosimetry. Furthermore, a fair agreement was found between theoretical and experimental results.

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  • IPEN-DOC 26808

    POLO, IVON O. ; SANTOS, WILLIAM S. ; CALDAS, LINDA V.E. . An extrapolation chamber for the establishment of a primary radiation standard in 85Kr and 147Pm beta radiation beams. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction At the Calibration Laboratory (LCI) of the IPEN/CNEN, studies are in development on the establishment of the Böhm extrapolation chamber model 23392 as a primary standard system for the dosimetry and calibration of beta-radiation sources and detectors. This chamber was already characterized at the LCI in 90Sr/90Y beams using two different entrance windows: one of aluminized Mylar and another of Hostaphan. This extrapolation chamber was characterized in 85Kr and 147Pm beams. All tests were carried out with the reference 90Sr /90Y source, for comparative purposes. Methods A Keithley model 6517B electrometer was used for the measurements. The utilized radiation sources are part of the Beta Secondary Standard BSS2. Moreover, the Monte Carlo code MCNP5 was used to determine the absorbed dose rates and to compare them with the experimentally determined dose rates and with those from the PTB calibration certifi cate. Results Saturation curves, ion collection effi ciency, ion recombination, polarity effect, response stability, real null depth, linearity of response, variation of response as a function of sourcedetector distance, extrapolation curves, correction factors and absorbed dose rates were obtained. The ion collection effi ciency was greater than 99%; the ionic recombination was less than 1%, and the polarity effect was greater than 1%. The stability of the response was lower than 0.15% for the repeatability test, and it was less than 0.36% for the reproducibility test. The difference between the experimental absorbed dose rates and those from the Monte Carlo model, compared to those from the calibration certifi cate, was less than 1.9% for all sources. Conclusions All results of the performed tests are within the limits of the international recommendations. The results for the 90Sr/90Y source were in the good agreement with previous works performed at LCI. These results are suitable for the establishment of a primary standard for beta radiation.

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  • IPEN-DOC 26807

    OTERO, ANDRE G.L. ; MARUMO, JULIO T. ; POTIENS JUNIOR, ADEMAR J. . Applying deep-learning in gamma-spectroscopy for radionuclide identification. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Neural networks, particularly deep neural networks, are used nowadays with great success in several tasks, such as image classifi cation, image segmentation, translation, text to speech, speech to text, achieving super-human performance. In this study we explore the capabilities of deep learning on a new fi eld: gamma-spectroscopy analysis. Using a well-known deep neural network architecture with gamma spectroscopy data, we successfully identify the radionuclides (Am-241, Ba-133, Cd-109, Co-60, Cs-137, Eu-152, Mn- 54, Na-24 and Pb-210) contained in several experiments. This neural network is also capable to identify different mixed radionuclide in the same source, demonstrating that deep neural networks can be successfully applied on gamma-spectroscopy analysis. Methods Using a HPGe detector to acquire several gamma spectra, from different sealed sources, we created a dataset that was used for the training and validation of the neural network. We created our deep neural network using python as programing language, alongside with Keras, a deep learning framework. Applying the VGG19 network architecture, except by the last layer which using softmax as activation function, we used sigmoid in order to allow classifi cation of not mutually exclusive classes in the same instance. Results After 250 epochs of training the classifi cation error on the training and test datasets reached a minimum, the same occurred with accuracy. As a fi nal test we used a spectrum from a triple sealed source, containing Am-241, Cs-137 and Co-60. As this kind of data was never seen by the network before we expect that the network generalizes well and correctly classify the spectra as containing the three isotopes. When applying the new data, the model correctly classifi ed the spectra as containing the tree radionuclide. Conclusions The model successfully classifi es different spectra with different radionuclides and his performance is good on never seen before data (the triple source sealed) demonstrating that deep learning can be used on a new domain.

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  • IPEN-DOC 26806

    SAVI, MATHEUS; BERTONCINI, MARCO A.; POTIENS, MARIA da P.A. . Commercial filament testing for use in 3D printed phantoms. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction With the popularization of 3D printing, many areas of knowledge are using this technology to create products and diminish costs, even in health segment. Commercial phantoms are expensive and hard to obtain in development countries. As alternative, 3D printed phantoms can be the way to produce inexpensive and reliable simulators aimed for dosimetry and teaching. That said, the objective of this study is to determine which of the available commercial fi laments can be used in 3D printing to mimic human tissue for use in 3D printed phantoms. Methods Fourteen 3D printing fi laments (ABS, ABS premium, PLA, PLA+Bone, PLA+aluminum, PLA+brass, PLA+cooper, SILK, HIPS, PETG, PVA, Wood, TPU and TPE) commercially available in Brazil had their attenuation tested, using computed tomography. Each material was printed as 2 centimeters edge cube with rectilinear pattern and 60, 80 and 100 percent infi ll. The cubes were scanned in a Philips CT Brilliance 6 with 120 kV, 200 mA, 2mm slices and standard reconstruction. At the center of each cube, an ~ 120 mm² region of interest were set to measure the mean Hounsfi eld Unit (HU) and the standard deviation value. For each material a graphic was plotted and the curve equation determined. Results The HU of the tested materials ranged from -516,2 ± 7,3 to 329,8 ± 18,9. All human tissues could be mimetized with these materials, except bone (mainly cortical bone). Considering the curve equation, the most promising fi lament was PLA+Cooper, due to the multiple infi ll confi guration that allows the resulting HU range to represent from adipose and skin tissue to marrow bone. With a two extruder printer may be possible add lung tissue to the model and make a 3D phantom more complex and accurate. Conclusions With these tested materials, is possible to construct various phantoms, simulating a wide range of tissues. However, any simulator with cortical bone is impaired because none fi lament achieve the required HU value (at least over 800 HU).

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  • IPEN-DOC 26805

    NASCIMENTO, ERIBERTO O.; BECATTI, MATHEUS J.P.; ANTONIO, PATRICIA L. ; VIEIRA, SILVIO L.; OLIVEIRA, LUCAS N. de ; CALDAS, LINDA V.E. . Quality control of solar protection films via design of experiments. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Solar radiation reaching the earth surface is broadly divided into infrared, visible and ultraviolet radiation (UVR). Individual dosimetry and monitoring of the sun rays in humans and environments is of interest since in homes, shops and cars the effects of UVR radiation can bring irreparable damage to the skin and eyes. The effi cacy of solar protective fi lms has been recognized as an important public health product. The objective of this work was the quality control of solar fi lms using the UV-Vis spectroscopy technique via 2k Experimental Factor. Methods Four types of solar protective fi lms were tested: G05, G20, G35 and WB (Windom Blue), which follow the blocking of UVR rays by 95%, 80%, 65% and 0% (76% transparent). The samples had dimensions of 1.0 x 3.0 cm2 and the readings were taken on a GENESYS™ 10S UV-Vis Spectrophotometer with an optical step of 1 nm from 190 nm to 400 nm. The absorbances were used in a 2k Experimental Factor, in which the four fi lms were read individually and also with overlap (two fi lms together). It was possible to obtain results of all the interactions among the fi lms, with or without overlap. Results The results about the absorption of the sunscreen fi lms were modeled from the 2k Experimental. This factor indicates that the best regions of the spectrum are blocked and/or where they produce a better quality control of these materials. The region studied in this work was where the ultraviolet radiation dosimetry can be of interest. The proposed spectrophotometric method is rapid, simple and cost effective for the evaluation on quality control of protection fi lms. Conclusions The results provide information on ultraviolet radiation and they can be useful for the medical physics community. The proposed methodology may be useful as a rapid quality control tool. It can be used during the production process, in the analysis of the fi nal product, and can offer important information for the scientifi c community.

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  • IPEN-DOC 26804

    ROSSI, MARIANA C.; BAYERLEIN, DANIEL L.; KRIECK, ANDRE M.T.; BRANDÃO, JAQUELINE de S.; PFEIFER, JOÃO P.H.; ROSA, GUSTAVO dos S.; STIEVANI, FERNANDA de C.; MARTINEZ, LUIS G. ; SAEKI, MARGARIDA J.; ALVES, ANA L.G.. Influence of space holder on the biocompatibility of Ti-34Nb-6Sn alloy prepared by powder metallurgy. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Development of metallic materials for denistry and orthoapedic area have been increasing, due to in world life expectancy and the significantly numbers of accide nts. Due to problems of failure in available commercial materials implantation, as well as the discomfort of patient because the high elastic modulus, these devices need to be improved or news implants should be sought. This study was intended to develop a porous alloy, Ti-34-Nb-6Sn/Mg wich can help the ingrowth bone tissue when implanted, by the powder metallurgy. After the milling powders in the high energy mill, were compacted and sintered. Both, powders and sintered materials were chacarterized by X-ray Difraction (XRD), Scanning Electron Microscopy (SEM) and semi-quantitative compositional analysis (EDS). The apparent porosity was measured through the Arquimed’s Method. The toxicity this material was evaluated by MTT assay, using the equine mesenchemal stem cells derivated of bone marrow (bmMSC) according to ISO 109935. The bmMSCs morphological analysis in contact on the material surface using SEM. The Mg evaporation was confirmed by EDS and XRD after sintering. The XRD indicate there is predominantly beta phase than alpha. The apparent porosity was higher in alloy with Mg space holder. The materials do not presented particular cytotoxic in direct and indirect contact. Metallurgic powder tecnhique promoted effectively macropores formation in Ti-34Nb-6Sn/Mg alloy, wich possibly further bmMSCs adhesion.

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  • IPEN-DOC 26803

    SAEKI, MARGARIDA J.; GARCIA, JOÃO I.M.M.; FERNANDES, CELIO J.C.; ROSSI, MARIANA C.; SILVA, WILLIAM de M.; MARTINEZ, LUIS G. ; ZAMBUZZI, WILLIAN F.. Characterization of titanium surface modified by calcium titanate. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Coatings based on apatite and others that contain calcium play an important role for the osseointegration with the implant. It is believed that released calcium induces a specific biological response to the living tissue establishing a stable chemical bonding between formed bone and implants. The mechanical anchorage of implants also depends on the surface structure and morphology. In this work, the titanium surface was modified by calcium titanate, which was deposited by sol-gel method combined to the dip coating technique followed by heat treatments. Two different emersion rate (5 and 10 cm/min) were used as well as the number of coatings were varied. The temperature of this treatment was established based on the results of the thermal analysis (TG/DTA). The surfaces were characterized by X-ray diffractometry (DRX), Scanning Electron Microscopy (SEM) and water contact angle measurement. The corrosion behavior of modified surfaces was evaluated by electrochemical method (polarization curves) in balanced saline Hanks solution. Finally, biological test was carried out by the analysis of cellular viability and adhesion of MC3T3-E1 (subclone 4), mouse pre-osteoblastic cells (ATCC CRL-2593), using MTT and crystal violet assays, respectively, after 24h incubation at 37oC in 5% CO2 atmosphere. The coating consists of anatase TiO2 (PDF 21-1272) and calcium titanate (CaTiO3, PDF 43-226). SEM analysis showed that homogeneous films with 0.8μm of thickness are provided when they are prepared by only one immersion and that the films increase the resistence to corrosion. The coating increases the wettability as the water contact angle decreases from 90o±10o for cp Ti (low interstitial titanium) to 34 o±5o. The biological test shows that the modifications do not interfere on the osteoblast viability and adhesion, however, the morphological analysis of preosteoblasts cultured on the modified Ti-surface by SEM shows that the coatings promote a cell spreading.

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  • IPEN-DOC 26802

    SILVA, ANDERSON M.B.; JUNOT, DANILO O. ; SOUZA, LUIZA F.; SOUZA, DIVANIZIA N.; CALDAS, LINDA V.E. . Caracterização do CaSO4:Tb,Ag para dosimetria OSL. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 24., 21-24 de agosto, 2019, Santos, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2019.

    Abstract: Embora a dosimetria por OSL seja bem conhecida, o uso dessa técnica tem sido pouco difundido devido à limitação de materiais. Conforme resultados da literatura, a prata como co-dopante em matrizes de CaSO4 dopado com terras raras proporciona um aumento da intensidade das emissões luminescentes em comparação aos materiais sem a prata. Sendo assim, como não há relatos sobre a caracterização estrutural e dosimétrica do CaSO4:Tb com a incorporação de prata, a proposta do presente trabalho foi produzir e caracterizar policristais de CaSO4 dopado com térbio e co-dopado com óxido e nanopartículas de prata. Os fósforos apresentaram uma curva típica de decaimento exponencial de OSL. As amostras de CaSO4:Tb,Ag(nanopartícula) apresentaram sensibilidade OSL cerca de 4 vezes mais intensa em comparação com CaSO4:Tb,Ag(óxido). Ambas as amostras apresentaram curva dose resposta linear na faixa de dose observada e limite inferior de detecção (LID) de 9 mGy para o CaSO4:Tb,Ag(nanopartícula) e 32 mGy para o CaSO4:Tb,Ag(óxido).

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  • IPEN-DOC 26537

    PRESTES, JOAO C.A. ; POTIENS, MARIA da P.A. ; XAVIER, MARCOS . Caracterização de um sistema irradiador utilizado em radioterapia para calibração de dosímetros clínicos. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 24., 21-24 de agosto, 2019, Santos, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2019.

    Abstract: Este trabalho apresenta as etapas de adequação e caracterização de um irradiador de 60Co, que era utilizado para tratamento para que seja utilizado em procedimentos de calibrações de dosímetros clínicos utilizados em radioterapia. Foi realizado a adequação de um sistema irradiador doado ao Laboratório de Calibração do Ipen e a caracterização do feixe e do campo de radiação, de acordo com as recomendações do guia da AIEA (TRS 469, 2009). Para a instalação do novo irradiador, foi realizada uma adaptação na atual sala de calibração para acomodar o cabeçote na posição de calibração. Um suporte foi confeccionado para o seu posicionamento. Na sequência foi necessária a correção no sistema de colimação que apresentou falhas na sua utilização. Para a caracterização do feixe de radiação foram realizados os testes iniciais de uniformidade do campo de radiação determinando o tamanho e o centro do feixe de radiação. Utilizando uma câmara de ionização de pequeno volume foi encontrada uma uniformidade maior do que 90% tanto no sentido vertical como no horizontal, para um feixe de radiação de 8 x 8 cm. As medições para a determinação das taxas de kerma no ar realizadas demonstram que o sistema está pronto para ser utilizado na calibração.

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  • IPEN-DOC 26801

    SANTANA, TATIANA D.; ROSSI, WAGNER de ; BARBOSA, PATRICIA A.; CARNEIRO, MARCELO B.. Caracterização por microscopia óptica 3D de ferramenta de corte texturizada por laser de femtossegundos. In: COLÓQUIO DE USINAGEM, 23., 12-13 de dezembro, 2019, Uberlândia, MG. Anais... Uberlândia, MG: Universidade Federal de Uberlândia, 2019.

    Abstract: As superfícies possuem características que podem impactar no coeficiente de atrito, na adesão de filmes e células, na retenção de fluidos lubrificantes, em aspectos ópticos, químicos e mecânicos. Dessa forma, muitos parâmetros foram criados com intuito de caracterizar as superfícies após um determinado processo de manufatura. Em geral, os equipamentos utilizados para realizar tal tarefa são categorizados em com e sem contato com as superfícies em avaliação. Nos processos de usinagem convencional, condições severas de atrito na interface cavaco ferramenta aumentam o desgaste da ferramenta e reduz o seu tempo de vida. A habilidade do fluido de corte penetrar na zona de corte pode ser melhorada pela texturização da superfície de saída da ferramenta. Neste trabalho, uma ferramenta de corte foi texturizada com o uso de um laser de femtossegundos, e caracterizada com o uso de um microscópio óptico 3D com tecnologia confocal que garante medições precisas da topografia, sem contato.

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  • IPEN-DOC 26800

    SILVA, J.C.M.; NTAIS, S.; RAJARAMAN, V.; ANTONIASSI, R.M. ; SPINACE, E.V. ; BARANOVA, E.A.. The catalytic activity of PtRu nanoparticles for ethylene glycol and ethanol electrooxidation in alkaline media. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 266-266.

    Abstract: The use of excessive fossil fuels has resulted in harmful effects on the environment and potentially human health. In this sense, direct alcohol fuel cells DAFCs are promising energy producing devices. Ethanol and ethylene glycol are appealing fuels for DAFCs due to their lower toxicity and high theoretical energy density, 8.01 kWh kg−1 and 5.2 kWh kg−1, respectively [1,2]. In this study, the carbon-supported PtRu nanoparticles with atomic ratios of Pt:Ru of 100:0, 90:10, 70:30 and 50:50 for ethanol and ethylene glycol electrooxidation in alkaline media, was investigated. The nanoparticles were synthesized using sodium borohydride method with 20 wt% of metals loading on carbon [1]. X-ray diffraction (XRD) analysis revealed that Pt and PtRu electrocatalysts have face centered cubic (fcc) structure and suggests the alloy formation for all PtRu/C materials, which was further supported by the X-ray Photoelectron Spectroscopy (XPS). According to transmission electron microscopy (TEM) the nanoparticle mean sizes were 7.3 nm, 5.7 nm, 5.2 nm and 5.1 nm for Pt/C, Pt90Ru10/C, Pt70Ru30/C and Pt50Ru50/C, respectively. Electrochemical measurements carried out in mol L-1 KOH + mol L−1 alcohol solution (ethanol and ethylene glycol) in a conventional three-electrode electrochemical cell (glassy carbon was used as work electrode and a platinum foil and a Hg/HgO were used as the counter and reference electrodes, respectively) demonstrated that the addition of Ru to Pt enhances the catalytic activity towards ethanol and ethylene glycol electrooxidadion in alkaline media. The catalyst of Pt50Ru50/C composition showed the lowest onset potential for ethanol and ethylene glycol electrooxidation (by Cyclic voltammetric), which are 160 mV and 70 mV lower than for Pt/C, respectively. Furthermore, this catalyst outperformed Pt/C and other PtRu/C compositions in chronoamperommetric and direct alcohol fuel cell (DAFC) experiments. DAFC experiments using Pt50Ru50/C as anode had the power density 40% and 14 % higher than using Pt/C for ethanol and ethylene glycol, respectively. The enhancement of the catalytic activity might be related to the high amount of oxides species on the Pt50Ru50 electrocatalysts surface, which could form Ru-OH at low potential and also due to the electronic effect of PtRu alloy that weakens the adsorption strength of poisonous intermediates from reactions [3].

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  • IPEN-DOC 26799

    BIANCOLLI, A.L.G.; LOPES, T. ; PAGANIN, V.A.; TICIANELLI, E.A.. Electrocatalysts and membranes for using in PEMFCs and AEMFCs fed by contaminated hydrogen. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 417-417.

    Abstract: Catalytic ethanol dehydrogenation has been proposed as a promising method to produce H2 without CO and CO2.¹ However, the dehydrogenation generates other types of organic by-products such as ethyl acetate, acetaldehyde and leaves unreacted ethanol that can cause power losses in the fuel cell. To make this technology accessible, fuel cells performances must be improved. In this context, we studied the influence of the main contaminants present in the hydrogen produced by the catalytic dehydrogenation of ethanol on the performance of proton exchange membrane fuel cells (PEMFCs) and anion exchange membrane fuel cells (AEMFCs). Investigations comprised the elucidation of the processes and reactions involved in the corresponding electrode systems, as well as the phenomena governing the electrochemical performance in the alkaline and acidic media, and in the absence and in the presence of the by-products. For the AEMFCs, the research initially involved the syntheses of ionomers and membranes and the optimization of their performances in single cells, using pure hydrogen and conventional electrocatalysts (Pt-Ru/C in the anode and Pt/C in the cathode).² However, due to the chemical instability when exposed to the contaminants, these materials seem to undergo degradation, leading to almost total and irreversible losses of the cell performance. A positive fact was that AEMs showed much less crossover of contaminants from the anode to the cathode. Through analyses by different techniques, it was found that unreacted ethanol is the main poison in the case of PEMFCs, with acetaldehyde and ethyl acetate having minor contributions. Different anodic and cathodic catalysts were tested in order to obtain better fuel cells performances, such as Pt-Sn/C, Pt- W/C, Pt-Co/C, Pt-Cr/C and Pt/C (Fig. 1). Also different types of membranes were tested (Nafion® 115, 117, and 212). The best result was achieved when the Pt- Co/C catalyst was used at the cathode (with Pt/C at the anode), for which the loss of power density was only 20% compared to a cell fed by pure H2 and with Pt/C on both electrodes (working at 0.7 V).

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  • IPEN-DOC 26798

    SILVA, R.P. ; SOUZA, R.F.B. de ; SANTOS, C.M.G. ; SILVA, A.J.; SANTIAGO, E.I. . Development of non-fluorinated membranes based on PBI for application in high temperature fuel cells (HT-PEM). In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 460-460.

    Abstract: Most of Proton Exchange Membrane Fuel Cells (PEMFCs) use the Nafion as electrolyte, which has a limitation in the operating temperature. Usually, these cells operate up to 80°C since the proton conduction is dependent on water molecules carriers. The increase in the operating temperature of a PEMFC cell is desired due to the contribution of the temperature in the acceleration of the electrochemical reactions, which are thermoactivated processes. In the context of searching alternative polymeric electrolytes, PBI (polybenzimidazole) membranes have been considered a promising membrane for high temperature operating PEMFC (HT-PEMFC) due to the combination of satisfactory proton conduction in conditions of low relative humidity (RH) and excellent thermal stability. Pure PBI membranes were prepared by casting a solution of PBI / N, N'-dimethylacetamide (DMAc) and doped with phosphoric acid at different times (1, 3, 5, 7 10 and 15 days). Each membrane was evaluated in Fuel Cell tests, doping level and online Raman tests in order to determine effects of doping level, chemical degradation and fuel cell performance. The electrodes were optimized by studying different catalytic layer composition and the cell tested at different operational conditions.

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  • IPEN-DOC 26797

    GUIMARÃES, V.P.; NANDENHA, J. ; FATIBELLO-FILHO, O.; NETO, A.O. ; VICENTINI, F.C.; ASSUMPÇÃO, M.H.M.T.. Development of nanomaterials for formate electrochemical oxidation aiming sustainable energy generation. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 436-436.

    Abstract: The world energy system is highly depended of fossil fuels, which is not sustainable [1]. Thus, the use of alternative energy is crucial and fuel cells are being considered good options. In this context, this work aimed to develop electrocatalysts based on palladium nanoparticles (PdNPs) supported on the physical mixtures of carbon (Vulcan XC72) and titanium dioxide (P25) toward formate oxidation in alkaline medium and its application in formate fuel cells. The materials were synthesized by the borohydride reduction method [2] with 20% (m/m) of metal loading and in two batches. In the first batch, the PdNPs were reduced in the physical mixture of carbon (C) and titanium dioxide (TiO2), in different proportions of C and TiO2, identified as Pd/(C+TiO2), while in the second one, the PdNPs were reduced only in TiO2 with later incorporation of C which were identifies as Pd/TiO2-C. On both batches, the ratios between C and TiO2 used were 75:25, 50:50 and 25:75 (m/m). A reference material, complied of PdNPs supported just on C (Pd/C) was also prepared. All materials were characterized by X-ray diffraction, showing peaks of the face-centered-cubic (fcc) structure of the Pd, as well as TiO2 peaks of anatase and rutile phases. Transmission Electron Microscopy (TEM) were also evaluated showing an average particle size between 3 and 8 nm. Electrochemical experiments considering voltammetry and chronoamperometry showed that the materials with PdNPs reduced in the TiO2 (Pd/TiO2-C) were more promising when compared to Pd/(C+TiO2), and among them Pd/TiO2-C 75:25 presented the highest current observed in chronoamperometry. Comparing the Pd/(C+TiO2) materials, the Pd/(C+TiO2) 50:50 presented the highest current. Taking into account single cell experiments, although the electrochemical results evidenced the improvement toward formate with PdNPs deposited firstly in the TiO2, the fuel cell tests showed the opposite, presenting the best cell efficiencies with Pd/(C+TiO2) materials, where Pd/(C+TiO2) 75:25 (ratio between C and TiO2) was the best material with the highest power density obtained. This fact can be explained by the higher conductivity of C, in a higher proportion, coupled with the small amounts of TiO2, which provides oxygenated species that facilitate the formate oxidation.

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  • IPEN-DOC 26796

    ZAMBONI, CIBELE B. ; ALMEIDA, MATEUS R. de ; MEDEIROS, JOSE A.G. de. Análise de zinco em sangue de corredores de longa distância / Zinc analysis in blood of long-distance runners. In: CONGRESSO BRASILEIRO DE CIÊNCIAS DO ESPORTE, 21st; CONGRESSO INTERNACIONAL DE CIÊNCIAS DO ESPORTE, 8th, September 15-20, 2019, Natal, RN. Resumo expandido... Porto Alegre, RS: Colégio Brasileiro de Ciências do Esporte, 2019.

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  • IPEN-DOC 26795

    ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. ; MORALLES, MAURICIO . Evaluation of peak-fitting software for gamma spectrum analysis. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 42.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 40., 1-5 de setembro, 2019, Campos do Jordão, SP. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2019.

    Abstract: In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width, for instance, are associated with each peak of each spectrum. Theres a huge choice of computer programs that perform this type of analysis, and the most commonly used in routine work are the ones that automatically locate and fit the peaks; this fit can be performed in several different ways - the most common are either to fit a Gaussian function to each peak or simply to integrate the area under the peak, but some software go far beyond and include several small corrections to the simple Gaussian peak function, in order to compensate for secondary effects. In this work several gamma-ray spectroscopy software are compared in the task of finding and fitting the gamma-ray peaks in spectra taken with some calibrated standard sources. The results allow for a discussion on the performance of each software in the tasks of identifying and determining the correct area of the gamma-ray peaks, as well as on the advantages and difficulties in using automatic programs when comparing with a manual peak-fitting software, used as reference.

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  • IPEN-DOC 26540

    ARAUJO, LEANDRO G. de ; WATANABE, NAOMI ; SILVA, THALITA T.; TEIXEIRA, ANTONIO C.S.C.; VELOSA, ADRIANA C. de; MARUMO, JULIO T. . Oxidative degradation of organic compounds from sludge by ozonation: study of process. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 45th, March 3-7, 2019, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2019. p. 1-6.

    Abstract: This study investigates the performance of the ozonation process in the treatment of petroleum sludge from an offshore production platform situated in Brazil. The effect of operating conditions is studied such as the phase to be treated and the sludge/water ratio. Total organic carbon content increased in O2 and O3 experiments, mainly because of the mixing factor. The decrease of sludge mass was observed in a situation of forced mixing and with only ozone flow. The liquid phase indicated a high TOC value, but very low radioactive activities, whereas the solid phase did not present detectable TOC amounts but significant values of radioactive activity. More experiments and analyzes will be carried out to obtain more relevant results for future discussion.

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  • IPEN-DOC 26794

    ZAMBONI, CIBELE B. ; GIOVANNI, DALTON N.S. ; MIURA, VINICIUS T.; GOMEZ, MONICA R.. Identificação de processos fotográficos utilizando a técnica de FRX. In: SIMPOSIO LATINOAMERICANO DE FÍSICA Y QUÍMICA EN ARQUEOLOGÍA ARTE Y CONSERVACIÓN DE PATRIMONIO CULTURAL, 7th, September 9-13, 2019, Ciudad de México, México. Abstract... Ciudad de México, México: Universidad Nacional Autónoma de México, 2019. p. 7-7.

    Abstract: O conhecimento da composição elementar de artes gráficas é de grande interesse para investigações de caráter histórico-artístico na medida em que possibilita identificar o processo de produção, a época de sua manufatura e, em alguns casos, sua procedência. Nos últimos anos, no Brasil, essas investigações têm adquirido relevância e estão sendo empregadas em acervos fotográficos pertencentes a museus, galerias de artes e a colecionadores particulares. As primeiras fotos tomadas em solo brasileiro datam de 1840 época da daguerreotipia. Desde então, com seu aperfeiçoamento, a fotografia tomou lugar de relevância cultural e viabilizou a geração de acervos particulares, sendo que muitos necessitam de devida caracterização, afim de situar o “objeto” dentro do contexto de sua própria época, além de agregar informações que auxiliem sua conservação e preservação. Atualmente a peritagem de obra de arte está crescendo no Brasil, em decorrência, estas informações podem agregar também valor econômico às produções gráficas. No presente estudo, o material de estudo compõe duas coleções fotográficas: uma com foco na arquitetura paulistana, e outra retratando personalidades do meio artístico. São acervos particulares cuja data e o processo de produção não são conhecidos. As análises de Fluorescência de Raios X por Dispersão de Energia (FRXDE) foram realizadas Laboratório de Espectroscopia e Espectrometria das Radiações (IPEN/CNEN-SP, Brasil), utilizando espectrômetro portátil de FRX da Amptek® com alvos de prata (Ag) e ouro (Au). Este instrumental é constituído por um detector de Silício Drift XR-100SDD (25 mm2 x 500 μm) com janela de Berílio (12,5 μm), acoplado a um pré-amplificador, um processador de pulso digital e multicanal. A condição de excitação foi estabelecida por 5 μA e 30 kV com tempo de contagem de 120 s. A análise elementar da coleção referente à arquitetura paulistana evidenciou o uso papeis com revestimento barita, muito utilizado por fotógrafos profissionais e amadores entre 1889-1930, evidenciam que essas fotos foram registradas entre o fim do século XIX e início do século XX. No que diz respeito ao acervo dos retratos, foi identificado o processo de cianotipia, evidenciado pela coloração azul das fotos (devido ao emprego sais de ferro como substância fotossensível), muito popular nas últimas décadas do século XIX [1,2]. Os resultados disponibilizados pela técnica de FRXDE permitiram situar a época e os processos fotográficos empregados. Essas informações contribuem para valorização desses acervos além de fornecer subsídios para o correto armazenamento e preservação.

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  • IPEN-DOC 26793

    BOIANI, N.F. ; SILVA, T.T.; BORRELY, S.I. . Toxicity assessment of caffeine, fluoxetine and their mixture on Daphnia similis: acute and cronic effects. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 13th, September 15-18, 2019, Cartagena, Colombia. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry, 2019. p. 109-109.

    Abstract: Emerging pollutants have already become a global problem, and they have been detected in dozens of countries, including Brazil. Even at very low concentrations, most of the emerging compounds are able to induce changes into biochemical system of aquatic organisms and they have also been reported as negative products to human health. Pharmaceuticals are considered as emerging contaminants detected in estuarine environment, in wastewater treatment facilities, lakes and rivers and even in sea waters. Generally the pharmaceuticals are detected among many other compounds into the ecosystem. The interaction of mixtures of contaminants is an important issue to be considered in monitoring programs as well as the negative effect to aquatic biota. The aim of the present paper was the assessment of toxic effects of pharmaceuticals exposed to Daphnia similis crustacean, individual and combined mixture of caffeine and fluoxetine. Caffeine (CAF) is a stimulant with cardiac, cerebral, diuretic and respiratory effects while Fluoxetine (FLX) is a selective serotonin re-uptake inhibitor, widely prescribed as antidepressant, (also known as Prozac®). The juveniles of D. similis were exposed separetaly to both caffeine (100mg/L) and to fluoxetine (20mg/L), and to a mixture of both (50mg/L caffeine and 20mg/L fluoxetine). Several experimental trials of acute immobilization test were performed. EC50 values ranged from 29,7 to 31 mg/L-1 for caffeine, and from 1.0 to 1.4 mg/L-1 for fluoxetine. Antagonistic effects of binary mixtures (EC50 = 15.2%) were observed. A chronic reproduction test was performed for the mixture of pharmaceuticals. We observed effects on D.similis survival, after 5 days. The mixture led to decrease of 72% in the reproduction, in maximum concentration (2.5% of the mixture – CAF 50ppm + FLX 20ppm). Concerning the importance of assessing toxicity the elected pharmaceuticals concentration were higher than those detected in the envinroment. These results may be incorporated into risk assessments analysis in order to protect sensitive aquatic ecosystems more effectively.

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  • IPEN-DOC 26792

    TOMINAGA, F. ; BOIANI, N.F. ; SANTANA, N.D.; BORRELY, S.I. . Acute toxicity assessment for binary and tertiary mixtures containing fluoxetine, propranolol and diclofenac to microcrustacean and zebrafish embryos. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 13th, September 15-18, 2019, Cartagena, Colombia. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry, 2019. p. 111-112.

    Abstract: Pharmaceuticals are essential for treatment and prevention of several diseases and for the maintenance of human and animal’s life quality. Due to the increasing use of pharmaceuticals worldwide, many actives substances are currently detected in μg.L-1 and ng.L-1 in different environmentals matrices such as surface water, ground water, soil and sediment. Many of these emerging pollutants are recalcitrant to biological treatment process in WWTPs and they may cause ecotoxicological effects on organisms and also possible to reach the human food chain. Pharmaceuticals are frequently detected as mixtures and may induce toxic effects to aquatic organisms, producing synergistic, additive or antagonistic toxic effects. Fluoxetine hydrochloride (FXT) is a selective serotonin reuptake inhibitor, prescribed as an antidepressant. Propranolol (PRP) is a beta-adrenergic blocker widely prescribed for the treatment of cardiovascular diseases and diclofenac sodium (DIC) is a non-steroidal anti-inflammatory drug, often recognized as the “world’s most popular pain killer”. These compounds are worldwide used for healthy treatment and also often detected in aquatic environments. This work aims to assess the toxicity of three pharmaceutical individually and in a mixture for both Daphnia similis and zebrafish embryos. The results of individual acute toxicity showed that the microcrustacean was more sensitive to FXT (EC50 = 1.08 mg/L), PRP (EC50 = 5.92 mg/L) and DIC (EC50 = 25.0 mg/L), respectively, while for zebrafish embryos, it was only calculated LC50 of 30.5 mg/L for DIC, after 48h exposure. Antagonistic effects of binary mixtures of FLX + PRP (EC50 = 9.38%) and FXT + DIC (EC50 = 24.2%) were observed to D. similis. For Danio rerio embryos, binary mixture of FLX + DIC (LC50 = 82.1%) presented antagonistic effects, while no acute toxicity was observed for the of FXT + PRP mixture. Tertiary mixture of the three compounds showed an antagonist effect (EC50 = 5.57%) for the microcrustacean and additive effect for zebrafish embryos (LC50 = 87.5%). In conclusion, most of the binary mixture resulted in antagonistic effects, in which the response of acute toxicity depended on the organism and type of pharmaceutical mixture. Therefore, it is necessary further studies to assess the toxicity of different mixtures.

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  • IPEN-DOC 26791

    BEU, CASSIA M.L. ; LANDULFO, EDUARDO . Threshold wind speed and turbulence under LLJs events at Ipero - Brazil. In: COMERON, ADOLFO (Ed.); KASSIANOV, EVGUENI I. (Ed.); SCHAFER, KLAUS (Ed.); PICARD, RICHARD H. (Ed.); WEBER, KONRADIN (Ed.); SINGH, UPENDRA N. (Ed.) SPIE REMOTE SENSING, September 9-12, 2019, Strasbourg, France. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 1115212-1 - 1115212-10. (Proceedings of SPIE Vol. 11152, Remote Sensing of Clouds and the Atmosphere XXIV). DOI: 10.1117/12.2532281

    Abstract: The threshold wind speed is a useful criterion in determining whether strong turbulence is generated within the Stable Boundary Layer (SBL), the layer where all surface emissions remain con ned during the night. Con dence turbulence estimates are extremely important for atmospheric transport and dispersion simulations, although due to its complex dinamics many aspects of the SBL are neglected by numerical models that, in turn, are the inputs and boundary conditions for the transport and dispersion simulations. Turbulence is especially important during severe episodies like hazardous material accidental releases, for example. Turbulence intensity can a ect the dispersion speed, released material concentration, and its reach. For many decades, remote sensing has been an important tool in lling the gap of information and providing advances in the atmospheric sciences. The doppler lidar is increasingly being used for micrometeoroly and Planetary Boundary Layer (PBL) studies because of its autonomy and long range capability, in contrast with traditional techniques as radioprobes and captive balloons. After 1 year of continuous measurements with a doppler lidar, it was possible to determine the threshold wind speed for Ipero, Sao Paulo, Brazil. Besides threshold wind speed, it was observed that the SBL turbulence has a straight relationship with the Low-Level Jets (LLJs) that frequently occur over the region. The vertical turbulence distribution depends greatly on the LLJ characteristics, which in turn is highly variable during its life cycle. The strong turbulence regime is associated to the stronger LLJs, that presents a more de ned pattern. In contrast, weak LLJs (that generate weaker SBL turbulence) present more dispersive characteristics in respect to the entire dataset. These di erences are seen both for the LLJ height as for the turbulence vertical pro le. These results will contribute for the atmospheric modeling and dispersion simulations, as well for the environmental studies at Ipero.

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  • IPEN-DOC 26790

    MACEDO, FERNANDA M.; CORREA, THAIS ; ARAUJO, ELAINE ; ANDRADE, IZABEL ; ARLEQUES, ANTONIO G. ; MIRANDA, JULIANA T. de M. ; SILVA, JONATAN da ; GUARDANI, ROBERTO; VESELOVSKII, IGOR; LANDULFO, EDUARDO . Correlation between two different real time data acquisition systems: LIDAR Raman and Cavity Ringdown Laser Spectroscopy, for CH4 as a fugitive gas, in São Paulo Metropolitan Area. In: COMERON, ADOLFO (Ed.); KASSIANOV, EVGUENI I. (Ed.); SCHAFER, KLAUS (Ed.); PICARD, RICHARD H. (Ed.); WEBER, KONRADIN (Ed.); SINGH, UPENDRA N. (Ed.) SPIE REMOTE SENSING, September 9-12, 2019, Strasbourg, France. Proceedings... Bellingham, WA, USA: SPIE, 2019. p. 111521D-1 - 111521D-14. (Proceedings of SPIE Vol. 11152, Remote Sensing of Clouds and the Atmosphere XXIV). DOI: 10.1117/12.2533111

    Abstract: Fugitive emissions, defined as unintended or irregular leaks of gases and vapors, these are an important source of pollutants to the atmosphere, which is difficult to monitor and control. These sources are present in different sites, including megacities like São Paulo that are growing in size and economic activity. At the same time, there is a remarkable growth in concerns about the environmental issues associated with these activities. In a constantly changing world, with increasing concentrations of greenhouse gases (GHGs), among them methane (CH4) and volatile organic compounds (VOC), mitigation of atmospheric emission of these gases to contain global warming, make field campaigns in the metropolitan region of São Paulo very relevant. Optical remote sensing techniques as lidar can attend the need for real time and trustable information on fugitive emissions. The Cavity Ringdown Laser Spectroscopy (CRDS) technique was adopted because it is widely used in the detection of gas samples that absorb light at specific wavelengths and also for their ability to detect mole fractions up to the parts per trillion level. The Raman lidar system used includes a commercial laser pulsed Nd:YAG Quantel S.A., model CFR 200, with wavelengths of 355 nm, 353 nm and 396 nm, 120 mJ pulse power, with laser repetition rate of 20 Hz and pulse width of 20 s, with a spatial resolution of 7,5 m. The system includes an ethernet interface, used together with LabView software to control the measurement and readout of the acquired data. The mixing ratio of CH4 can be observed within the planetary boundary layer. The measured methane profiles correlate with the acquisitions made with the CRDS, however, an additional contribution of control data in which the Raman lines detect with high sensitivity.

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  • IPEN-DOC 26789

    GEORGESCU, GABRIEL; NUNES, MARCOS E.C.; OLIVEIRA, PATRICIA da S.P. de ; WIELENBERG, ANDREAS; NIEMELA, ILKKA; DUPUY, PATRICIA. RISKAUDIT and CNEN cooperation on probabilistic safety analysis. In: INTERNATIONAL TOPICAL MEETING ON PROBABILISTIC SAFETY ASSESSMENT AND ANALYSIS, 16th, April 28 - May 3, 2019, Charleston, South Carolina, USA. Proceedings... Illinois, USA: American Nuclear Society, 2019. p. 781-784.

    Abstract: The Brazilian project BR3.01/12 financed by European Union through the “Instrument for Nuclear Safety Cooperation” (INSC) programme and accomplished by RISKAUDIT organization (IRSN, GRS and STUK) constituted a support for enhancing and strengthening Brazilian Safety Authority (CNEN) expertise in regulatory and licensing activities, including probabilistic safety analysis (PSA), deterministic analysis and ageing management. The objectives of the project PSA task were to provide support to CNEN on the enhancement of its regulatory capability related to PSA development, review and applications and to provide support to CNEN on the review of the documents related to parts of Level 1 and 2 PSAs submitted by the utility, Eletronuclear (ETN), for the Brazilian NPPs of the CNAAA, which is a nuclear station located in Angra dos Reis, Rio de Janeiro. The activities focused on the updating and enhancement of Brazilian regulatory requirements for development and use of PSA, development of the Brazilian guide on regulatory review of PSA, support CNEN on the preliminary review of the PSAs for Angra 2 NPP, support CNEN on the management of Level 1 PSA computer codes and training CNEN staff on PSA methods, PSA review and PSA applications. The project, which started in May 2015, successfully ended in May 2018.

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  • IPEN-DOC 26788

    SILVA, N.F. ; SILVA, T.F.; CASTRO, M.C. ; LUZ, H.N. da; CALDAS, LINDA V.E. . Garfield++ simulation of a TH-GEM based detector for standard mammography beam dosimetry. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: The TH-GEM based detector is a robust, simple to manufacture, high-gain gaseous electron multiplier. Its operation is based on a standard printed circuit board (PCB) coated on both sides by metallic material, perforated in a millimeter pattern, and immersed in gas. In order to study the feasibility of using TH-GEM type detectors in dosimetric applications for standard mammography beams, a prototype with adequate dimensions and materials was produced. The present work encompasses the calculations of electric fields by the Gmsh and Elmer software packages and the avalanche simulation using Garfield++ library of a TH-GEM detector filled with Ar/CO2 (70:30) mixture at atmospheric pressure.

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  • IPEN-DOC 26787

    POLO, IVON O. ; CALDAS, LINDA V.E. . Fading estimation of SOL-GEL α-Al2O3 detectors. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: The OSL and the TL techniques are used in several fields of radiation dosimetry. The dosimeters are affected by a signal loss in the time between the irradiation and readout (fading). This undesirable characteristic can cause an underestimation of the irradiation dose. The fading estimation of SOL-GEL α-Al2O3 with several different concentrations of impurities is reported. The thermal fading and the light-induced fading of the SOL-GEL α-Al2O3 detectors were estimated. Furthermore, the exponential equations used to interpolate the experimental results were presented.

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  • IPEN-DOC 26786

    SANTOS, WILLIAM S. ; SANTOS, CARLA J.; SILVA, ALINE F. da; SOUZA, SAMARA P.; NEVES, LUCIO P.; BELINATO, WALMIR; CALDAS, LINDA V.E. ; PERINI, ANA P.. Dose evaluation in breast brachytherapy using different 125I seeds: a Monte Carlo approach. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: A very common type of cancer among women is the breast cancer. The treatment choice depends, among several factors, on the clinical stage of the disease and the age. One way to treat breast cancer is the permanent breast seed implant, with Iodine-125 (125I). Since they present some advantages: possibility to treat solid tumors, near the tumor site, induction of little trauma and strong lethality to cancer cells. In Brazil, a new 125I seed was developed at the Instituto de Pesquisas Energéticas e Nucleares to be applied in brachytherapy. Given the large number of women diagnosed with breast cancer, in this work, the dose determination in organs and tissues was undertaken, considering this new seed and a commercial, Amersham 6711-Oncoseed®, employing the Monte Carlo method. Moreover, for a better understanding of the radiation doses delivered to different patients, the breast volumes were modified. For this purpose, the MCNPX Monte Carlo code was utilized coupled with female virtual anthropomorphic phantoms. The results pointed out the highest dose values for the breast and skin. Furthermore, the dose results for both types of seeds were very similar.

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  • IPEN-DOC 26785

    SANTOS, WILLIAM S. ; NEVES, LUCIO P.; PERINI, ANA P.; SANTOS, CARLA J.; BELINATO, WALMIR; SILVA, ROGERIO M.V.; SOARES, MARIA R.; VALERIANO, CAIO C.; CALDAS, LINDA V.E. . Computational modelling of cervix uterus radiation procedure using a virtual anthropomorphic phantom and the MCNPX code. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: There is a serious, and growing, concern about the increased risk of the emergence of a secondary cancer, radio-induced, associated with radiotherapy treatments. To assess the radiation doses to organs outside the target volume, in this work, several computational exposure scenarios were modelled, based on Monte Carlo simulation (MCNPX code). A Varian 2100c accelerator, and a female virtual anthropomorphic phantom were used, in a simulated treatment of cervical cancer. The determination of the dispersed dose would be important for assessing the risk in different organs or tissues. Four treatment fields were applied, varying the gantry angle. It was possible to observe that the conversion factors for equivalent dose were higher for the AP projection. For the RLAT and LLAT projections, the results were similar, fact that may be attributed to the symmetrical distributions of the organs in relation to the radiation source. The results presented in this work showed that the computational exposure scenario provides a versatile and accurate tool to estimate in a ready way the absorbed doses during a cervical treatment.

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  • IPEN-DOC 26784

    LITVAC, DANIEL ; CALDAS, LINDA V.E. . Calibration of a clinical beta therapy applicator using the thermoluminescence samples: preliminary results. In: CONGRESSO BRASILEIRO DE METROLOGIA, 10.; CONGRESSO INTERNACIONAL DE METROLOGIA ELÉTRICA, 13.; CONGRESSO INTERNACIONAL DE METROLOGIA MECÂNICA, 5.; CONGRESSO BRASILEIRO DE METROLOGIA DAS RADIAÇÕES IONIZANTES, 6.; WORKSHOP DA REDE DE METROLOGIA QUÍMICA DO INMETRO, 4.; CONGRESSO BRASILEIRO DE METROLOGIA ÓPTICA, 3., 24-27 de novembro, 2019, Florianópolis, SC. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Metrologia, 2019.

    Abstract: In some parts of Brazil, 90Sr/90Y clinical applicators are still used for dermatological and ophthalmic treatments, even with the higher efficiency of linear accelerators because they are of lower cost and easier use. Calibration and periodic recalibration of these applicators to verify the absorbed dose rate is essential to ensure accuracy in clinical treatments. In this work the thermoluminescent response of BeO and μLiF pellets was evaluated, determining the reproducibility, linearity of response and their dose-response curves. This standard, for this type of calibration, recommends the use of small detectors such as μLiF. Therefore, the utility of μLiF and BeO in the calibration of clinical applicators was compared.

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  • IPEN-DOC 26783

    SANTOS, ADIMIR dos ; YAMAGUCHI, MITSUO ; FANARO, LEDA C.C.B. ; SANTOS, DIOGO F. dos ; SOUZA, GREGORIO S. de ; JUNQUEIRA, FERNANDO de C. ; SILVA, GRACIETE S. de A. e ; BELCHIOR JUNIOR, ANTONIO ; PRADO, ADELK de C. ; JOAO, THIAGO G.; ROSSI, PEDRO C.R.. New plate-type core of the IPEN/MB-01 research reactor facility for validation of RMB project. In: INTERNATIONAL CONFERENCE ON RESEARCH REACTORS, November 25-29, 2019, Buenos Aires, Argentina. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2019. p. 1-8.

    Abstract: The IPEN/MB-01 research reactor had its first criticality in November 1988 and, ever since, has been of major importance in Brazilian reactor physics researches, achieving international level for experiments comparison and validation (benchmarks). In this facility it is possible to build many different core configurations (i.e., rectangular, square and cylindrical), once versatility and flexibility were both taken into account on its initial project. The core is a fissile material assembly, inserted in a water tank, where the chain reaction is self-maintained and controlled at low power levels, so that, in normal operation, the feedback effects of temperatures are negligible. The core is intended for neutrons simulation of light water moderated reactors allowing the experimental verification of the calculation methods, reactor cell and mesh structures, control rods effectiveness, isothermal reactivity coefficients and core dynamics due to reactivity insertions. The first standard IPEN/MB-01 core had UO2 rod-type fuel, 4.3 % enriched in U-235 and using B4C and Ag-In-Cd rods for safety and control of the reactor. The facility is located at IPEN/CNEN-SP (Nuclear and Energy Research Institute), in Sao Paulo - Brazil. Within the scope of the new research reactor project, the Brazilian Multipurpose Reactor (RMB), it was designed a new critical configuration for the IPEN/MB-01. After thirty years of work, the rod-type fuels were replaced by plate-type fuels, in order to validate the RMB calculation methodologies, as well as the nuclear data libraries used. The RMB is an open pool-type reactor with maximum power of 30 MW, being the core a 5x5 configuration, consisting of 23 fuel elements, made of U3Si2-Al, having a medium density of 3.7 gU/cm3 and 19.75% enriched in U-235, and two positions available in the core for materials irradiation devices. The production of radioisotopes, silicon doping, neutron activation analysis, nuclear fuels and structural materials testing and the development of scientific and technological research using neutron beams are the main targets of the RMB enterprise. The new IPEN/MB-01 core has a 4×5 configuration, having 19 fuel elements, consisting of U3Si2-Al, 2.8 gU/cm³ and 19.75% enriched in U-235, plus one aluminum block. The IPEN/MB-01 new plate-type fuel assembly uses Cadmium wires as burnable poison, as the one used in RMB core for controlling the core power density and excess of reactivity during its operation. The core is also reflected by 4 boxes of heavy water (D2O), inserted in a moderator tank of light water. The maximum nominal power is 100 W and, for a safe operation, the critical assembly has both safety and auxiliaries’ systems. This paper presents a description of the new core and the principal neutronic parameters. The new core of the IPEN/MB-01 will be certainly a world class benchmark core for the core physics calculation of research reactors.

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  • IPEN-DOC 26782

    FUNGARO, D.A. ; ROVANI, S. . Extração de sílica a partir das cinzas de resíduo da cana-de-açúcar em diferentes condições de extração alcalina. In: BALDOVI, ALDREW A. (Ed.); CONCEIÇÃO, ANA C.S. (Ed.); ANTENOR, ANANDA de O.G. (Ed.); CHYOSHI, BRUNA (Ed.); COSTA, DANILO O. da (Ed.); ANDRADE, HEDLLA M. (Ed.); FARIA, JULIA K. (Ed.); KOHATSU, MARCIO Y. (Ed.); MENDES, MARIANA E. (Ed.); COELHO, LUCIA, H.G. (Coord.); TAMBOSI, LEANDRO R. (Coord.) SIMPÓSIO DE CIÊNCIA E TECNOLOGIA AMBIENTAL, 1st, 2-3 de outubro, 2019, Santo André, SP. Anais... Santo André, SP: Universidade Federal do ABC, 2019. p. 239-244.

    Abstract: Uma amostra de cinzas geradas durante a queima de resíduos de cana-de-açúcar foi triturada com NaOH sólido variando-se a relação cinzas: NaOH (m/m). As misturas foram submetidas ao processo de fusão a 450 oC por 1 h. Após o resfriamento, a sílica da massa fundida foi lixiviada para a fase líquida na forma de silicato de sódio. Seguindo a separação do sólido e do líquido, partículas de sílica foram precipitadas pela adição de ácido sulfúrico até pH 7 à solução de silicato de sódio. O rendimento das amostras mostrou-se constante e uma pureza de 89% foi alcançada. As amostras de cinzas e de sílica produzidas foram caracterizadas por difração de raios-X, fluorescência de raios-X e análise elementar.

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  • IPEN-DOC 26781

    URBANI, G.L.; FRANCO, M.K.K.D. ; YOKAICHIYA, F. ; VICENTE, R. . Aplicação da química de radiação à questões tecnológicas do cimento relacionadas ao desenvolvimento de repositórios de rejeitos radioativos do modelo borehole. In: BALDOVI, ALDREW A. (Ed.); CONCEIÇÃO, ANA C.S. (Ed.); ANTENOR, ANANDA de O.G. (Ed.); CHYOSHI, BRUNA (Ed.); COSTA, DANILO O. da (Ed.); ANDRADE, HEDLLA M. (Ed.); FARIA, JULIA K. (Ed.); KOHATSU, MARCIO Y. (Ed.); MENDES, MARIANA E. (Ed.); COELHO, LUCIA, H.G. (Coord.); TAMBOSI, LEANDRO R. (Coord.) SIMPÓSIO DE CIÊNCIA E TECNOLOGIA AMBIENTAL, 1st, 2-3 de outubro, 2019, Santo André, SP. Anais... Santo André, SP: Universidade Federal do ABC, 2019. p. 226-231.

    Abstract: Resíduos radioativos são usualmente descartados em repositórios do tipo borehole ou de superfície. Por questões de segurança, devem ser depositados em tambores e cobertos por cimento na sua destinação final. A radiação gama proveniente dos resíduos radioativos interage com a água livre da pasta de cimento e causa o fenômeno da radiólise. Essa interação que decompõe a água da pasta de cimento é estudada pela academia científica e ainda não é um consenso se a mesma afeta a resistência do concreto ou não. Para um melhor entendimento dessa questão, nesse estudo um modelo teórico simples é sugerido para quantificar a porcentagem da água que sofre radiólise e se essa perda é suficiente para afetar a resistência da barreira de cimento. O resultado indica que a quantidade de água perdida neste processo não é suficiente para diminuir a resistência do concreto. O modelo proposto foi aplicado para verificar os resultados experimentais, utilizando as condições iniciais expostas na literatura existente, com o propósito comparação e discussão sobre o fenômeno da radiólise.

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  • IPEN-DOC 26780

    ZUFFI, ARMANDO V.F. ; ALMEIDA, ANDREIA A. ; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Development of glass nozzles for below threshold harmonics and high harmonic generation. In: FRONTIERS IN OPTICS; LASER SCIENCE CONFERENCE AND EXHIBITION, 15-19 September, 2019, Washington, DC, USA. Resumo expandido... Washington, DC, USA: OSA, 2019.

    Abstract: This work reports development of glass nozzles by ultrashort laser pulses machining for studies of harmonic generation in gases. Those nozzles generated odd harmonics (3rd up to 25th) in UV and VUV regions.

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  • IPEN-DOC 26779

    TOMINAGA, F.K. ; SILVA, T.T.; JESUS, J.M.S. de; BOIANI, N.F. ; TEIXEIRA, A.C.S.C.; BORRELY, S.I. . Effect of electron beam irradiation on mineralization and toxicity of aspirin. In: IBEROAMERICAN CONFERENCE ON ADVANCED OXIDATION TECHNOLOGIES, 4th; ISE SATELLITE STUDENT REGIONAL SYMPOSIUM ON ELECTROCHEMISTRY, 7th, November 18-22, 2019, Natal, RN. Resumo expandido... 2019. p. 1-3.

    Abstract: Electron Beam Irradiation (EBI) is an important technology for degradation, mineralization and detoxification of pollutants. In this work, total organic carbon (TOC) and toxicity was evaluated for aspirin after Electron Beam Irradiation at doses of 1.0, 2.5 and 5.0 kGy. Low mineralization was achieved at all applied doses. Toxicity increase and hydrogen peroxide formation was observed with the increase of absorbed dose. EBI can be an interesting alternative process applied as a pre-treatment for alternatives AOPs.

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  • IPEN-DOC 26778

    ROSSI, WAGNER de ; HERRERA, CRISTHIANO da C.; GOMES, ANTONIO A. ; BALDOCHI, SONIA L. . Femtosecond laser micromachining of microfluidic components in BK7 optical glass. In: EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES, September 1-5, 2019, Stockholm, Sweden. Abstract... Boutersem, Belgium: Federation of European Materials Societies, 2019. p. 898-898.

    Abstract: Introduction/Purpose The objective of this work was the development of micromachining with femtosecond laser in BK7 optical glass for the production of components of microfluidic devices. The aim was to produce microchannels, microvalves, micropumps, mixers and a localized heater, which can be arranged in any way to produce microfluidic devices on demand. Methods The structures were machined on the surface of BK7 glass plates, with the use of ultrashort laser pulses of a Ti:sapphire system on a high precision displacement stage and numerical control program. The first step was to obtain a set of process parameters suitable for efficient and accurate machining that would result in a smooth surface with no collateral damage to the neighboring region. Results Microvalves were machined with these optimized parameters, and when powered by pneumatic drive and managed by a dedicated software presented a flow control of less than 1 nl/s. These microvalves were used together to produce micrpumps to control flows in regions where external pressure can not be achieved. Mixers are also being developed for single phase systems and for biphasic systems. A machine vision system is being used to characterize both systems. Color analysis for single phase mixers and bubble analysis for biphasic ones. An innovative localized heating system was developed for temperature control in microreactors. For this, a tiny metal blade was textured with fs laser where light absorptive nanostructures were obtained. The slide was introduced into a microreator that had its temperature controlled through the focusing of an external source of light on its surface. With this, it was possible to control temperature above 100°C inside the microreator. Conclusions With the developed components, some microfluidic systems were built. In particular, a system for synthesis of NaYF4 nanocrystals and for ELISA assays will be presented.

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  • IPEN-DOC 26777

    FREIRE, L.O. ; ANDRADE, D.A. de . The four functions of elementary pipe design from constructal law. In: CONSTRUCTAL LAW AND SECOND LAW CONFERENCE, March 11-13, 2019, Porto Alegre, RS. Resumo expandido... 2019. p. 1-4.

    Abstract: Constructal law explains the sense of evolution (morphing to improve flows) of beings, but paradoxes do exist as not all vegetables have a tree form. Also, not all animals are optimized for displacement. This work aims at identification of the design functions or objectives that guide evolution under the overall statement of constructal law. This work adopted the system engineering technique of segregation between functions (abstract objectives) and solutions (physical entities). Further, this work introduced the assumptions of flow under external threats and pipes subject to leakages. Results showed that there are always elements doing four functions in pipe element: to reduce flow entropy, to protect flow channel, to retain flow content and to increase flow drive. Although the four functions are always present, natural systems typically privileges some functions over others, depending on environmental pressures. As a solution to improve flows, animal brains also fit in the model of four functions. Human mind seems to have groups of instincts associated to each of the four pipe design functions (fear, attachment, curiosity and greed). Finally, the four functions model unified physics and animal psychology.

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  • IPEN-DOC 26776

    GATTI, LUCIANA; MILLER, JOHN B.; BASSO, LUANA S.; DOMINGUES, LUCAS G. ; CASSOL, HENRIQUE L.G.; MARANI, LUCIANO; CORREIA, CAIO S. de C. ; IPIA, ALBER; ARAI, EGIDIO; TEJADA, GRACIELA; ARAGÃO, LUIZ E.O.C.; ANDERSON, LIANA O.; VON RANDOW, CELSO; GLOOR, MANUEL; PETERS, WOUTER; NEVES, RAIANE A.L.; CRISPIM, STEPHANE P.. Amazon carbon balance and its sensitivity to climate and human-driven changes. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: The Amazon accounts for 50% of Earth’s tropical rainforests hosting the largest live carbon pools in vegetation and soils (~200 PgC). The net carbon exchange between tropical land and the atmosphere is critically important, because the stability of carbon in forests and soils can be disrupted on short time-scales. The main processes releasing C to the atmosphere are deforestation, fires and changes in growing conditions due to increased temperatures and droughts. Such changes may thus cause feedbacks on global climate. In the last 40 years, the Amazon mean temperature has increased by 1.1ºC. Annual mean precipitation has also decreased by 51 mm during this same 40 year period. The precipitation reduction occurred mainly in the dry season, and the dry season has lengthened, exacerbating vegetation water stress with consequences for carbon balance. To better understand its C budget, starting in 2010 we established a regionally representative greenhouse gas monitoring program across Amazonia. The program aims to quantify gas concentrations (CO2, CH4, N2O, CO, and SF6) based on extensive collection of air from light aircraft vertical profiles. The atmosphere is profiled from the ground up to 4.5 km height at four sites along the main air-stream over the Amazon Basin on a twice-monthly basis. Here we will report what these new data tell us about the carbon balance and its controls from 2010-2017. During this period we performed 513 vertical profiles over four strategic regions that represent fluxes over much of Amazonia. The observed variability of carbon fluxes during these 8 years is correlated with climate-related (temperature, precipitation, soil water storage from GRACE satellite) and anthropogenic (fire counts) variables. The correlations were performed inside the upwind area for each profiling site. During our study period, the Amazon was a consistent source of 0.4 ± 0.2 PgC/year on average, extrapolating to the entire Amazon Basin area of 7.2 million km2. Fire emission is the main source of carbon to the atmosphere, which is not compensated by the C removal from old-growth Amazon forest. Moreover, the drought years of 2010, 2015 and 2016 are playing an outsized role in the eight-year mean. Removing those years from the mean, the net source is reduced from 0.4 ± 0.2 PgC/year to 0.2 ± 0.2 PgC/year.

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  • IPEN-DOC 26775

    MORAIS, FERNANDO; LANDULFO, EDUARDO ; ARTAXO, PAULO; FRANCO, MARCO A.; SCHAFER, JOEL; HOLBEN, BRENT. Long term characterization of brown carbon in Amazonia using AERONET and in situ measurements. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Optical properties of aerosols in Amazonia have been measured over the last 19 years at several AERONET sites using CIMEL sunphotometers. Ground based measurements of aerosol absorption properties using AE33 Aethalometers were performed in several sites in Amazonia. Measurements were done in Central Amazonia (ATTO tower), as well as in Rio Branco, Cuiabá, Ji-Paraná, and Alta Floresta. The results show an important contribution to absorption by the brown carbon (BrC) component together with black carbon (BC). This behavior can be strongly observed at the wavelengths of 440nm and 470nm, for AERONET and AE33 measurements, respectively. Results from AERONET showed that, in sites dominated by biomass burning such as Alta Floresta, Rio Branco and Ji-Paraná, the BrC was about 20% of BC. In special, for the dry season of 2018 at Rio Branco, the BrC was about 9% of BC, with values of 3.28±3.45 µg m-3 and 0.34±0.58 µg m-3 for BC and BrC, respectively. The measured high variability in the ratio BrC/BC was due to different aging of biomass burning plumes that reached the site, some with high BC values of up to 24 µg m-3. On the other hand, in situ measurements at the ATTO Tower showed that the BrC component can account for 30% of total absorption. For the wet season of 2019, it was observed that BrC accounts for 28 % of BC, with mean values of BC and BrC of 0.23±0.16 µg m-3 and 0.054±0.075 µg m-3, respectively. The high variability in this case was due to plumes of African biomass burning that reached the site in different periods. For central Amazonia, ground based in situ measurements and AERONET agree quite well in the in situ BrC determination, showing a well-mixed atmosphere due to strong convection.

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  • IPEN-DOC 26774

    JEONG, DAUN; SECO, ROGER; EMMONS, LOUISA K.; SCHWANTES, REBECCA; LIU, YINGJUN; MCKINNEY, KARENA A.; MARTIN, SCOT T.; KEUTSCH, FRANK N.; GU, DASA; GUENTHER, ALEX B.; VEGA, OSCAR ; TOTA, JULIO; SOUZA, RODRIGO A.F. de; SPRINGSTON, STEPHEN R.; WATSON, THOMAS B.; KIM, SAEWUNG. Reconciling measured OH through box model simulations during GoAmazon2014/5. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Hydroxyl radicals (OH) are important oxidants in the troposphere, controlling the lifetime of trace gases including methane, which is a greenhouse gas. The primary production of OH is from the photolysis of O3. OH levels can be further sustained through HOx-NOx recycling reactions. Volatile organic compounds (VOC) react with OH to produce organic peroxyl radicals (RO2), which can oxidize NO to NO2, leading to O3 production and subsequent re-generation of OH. However, in low NOx and high VOC environments, OH levels can be limited due to the production of stable peroxides from reactions between peroxy radicals. Therefore, conventional chemistry predict constrained OH levels in remote forest regions. Observations of OH carried out in forests, however, have consistently reported up to 10-fold higher than expected OH levels. In this study, we report OH observations by chemical ionization mass spectrometry (CIMS) conducted in a rainforest environment during the GoAmazon2014/5 campaign. The measurements used in this study, were during the wet season (IOP1), at the T3 site, which was ~ 60 km west of Manaus, Brazil. OH observations are compared to observation constrained box model simulations embedded with a near-explicit chemistry like MCM 3.3.1 (Master Chemical Mechanisms) and condensed mechanisms like RCIM (Reduced Caltech Isoprene Mechanism), CB05 (Carbon Bond Mechanism), CB6r2 (Carbon Bond 6 Mechanism), RACM2 (Regional Atmospheric Chemistry Mechanism), and MOZART_T1 (Model for Ozone and Related Chemical Tracers) that are used in global models.

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  • IPEN-DOC 26773

    CORREA, E.L. ; PEREIRA, L.F. ; FERREIRA, W.L. ; BOSCH-SANTOS, B. ; SCALISE, L. ; GONÇALVES, V. ; SANTOS, R. dos ; SCHELL, J.; CARBONARI, A.W. . Study of the local magnetics and electrics properties at Gd2Ti2O7 by PAC spectroscopy and ab initio calculations. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 760-760.

    Abstract: Gd2Ti2O7 exhibits a complex magnetic behavior with a geometrically frustrated antiferromagnetic ordering below TN = 1.1 K and a second magnetic transition at 0.7 K. In the work here reported, perturbed angular correlation (PAC) technique was used in order to measure electric quadrupole hyperfine interactions at 111mCd probe nuclei on Ti sites. These experimental results along with those for magnetic hyperfine interactions at 155Gd previously reported from Mossbauer Effect spectroscopy were interpreted with electronic structure first-principles calculation. Single and doped-Cd cell simulations have been performed with potential linearized augmented plane waves methods and generalized gradient approximation from Perdew-Burke-Ernzerhorf embodied within the WIEN2k all-electron code. PAC measurements have exhibited 111mCd probes occupying two fraction sites characterized by well-defined quadrupole frequencies (as shown in the spin-rotation spectra in the figure) with almost the same values for the corresponding electric field gradient (efg), however, with slightly difference in the asymmetry parameters. Theoretical efg’s obtained for Cadmium atoms located at Gd or Ti sites of the pyrochlore structure indicate that both experimental hyperfine parameters corresponding to Cd at Titanium site.

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  • IPEN-DOC 26772

    BOSCH-SANTOS, B. ; NASCIMENTO, N. ; SAIKI, M. ; CORREA, E.L. ; SALES, T.S.; PEREIRA, L.F. ; CABRERA-PASCA, G.A.; CARBONARI, A.W. . Magnetic field at Ce impurities in La sites of LaBaMn2O6 double perovskites. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 759-760.

    Abstract: Magnetic behavior in LaBaMn2O6 double perovskite compounds has been investigated with various techniques, due to the rich variety of electromagnetic properties, such as a colossal magnetoresistance, charge and orbital ordering, and metal-insulator transition. In this paper, we have used a nuclear and short-range technique, the Perturbed Angular Correlation (PAC) spectroscopy, to investigate the magnetic hyperfine field at the 140Ce nucleus of Ce impurities occupying La sites. The radioactive 140La nuclei with a half-life of 40.8 h were produced by direct activation of natural La present in the samples through the irradiation with neutrons in the IEA-R1 nuclear research reactor of IPEN. The PAC measurements were carried out with a six BaF2 detector spectrometer at several temperatures between 10 K and 400 K. This double perovskite samples were synthesized by sol-gel route. The crystal structure was determined by X-ray diffraction and the analyses showed that this method produced perovskite oxides with cubic structure in Pm-3m space group. This phase occurs due to an oxygen deficiency. The local properties investigated by PAC spectroscopy revealed a ferromagnetic transition temperature above 300 K and an anomalous behavior of the temperature dependence of magnetic hyperfine field at La sites, which can be ascribed to the contribution of 4f band of Ce to Bhf at low temperatures due to the increase in its localized character.

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  • IPEN-DOC 26771

    PEREIRA, L.F. ; CARBONARI, A.W. . Local magnetic interactions in Cadmium-doped Cobalt allotropic phases by first principles calculation. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 600-600.

    Abstract: Cobalt is one of the most attractive ferromagnetic material at room temperature. While Co is used in industrial processes of catalysis, in fundamental science, the connection between the different crystal structure with magnetic properties of Co has attained the attention. Co can crystallize in four different structures: hexagonal closed-packed (hcp, alpha), face-centered cubic (fcc, beta), primitive cubic (epsilon), and body-centered cubic (bcc). The hcp and fcc phases are stable in bulk and nanostructured samples and the difference in their formation energy is small so that, even under small variations of temperature and/or pressure conditions, hcp and fcc can interexchange easily. Often, the literature reports the co-existence of both structures. In last years, new routes of the synthesis and improvement in previous methods have allowed the production of nanostructured Cobalt samples with Epsilon and bcc crystalline phases, which under usual conditions are metastable. The magnetic properties vary with the structure differences in their electronic structure, e.g. the hcp phase has higher coercivity, whereas the fcc is a soft magnet In the work here reported, first-principles calculations were performed in the four Co structures in order to investigate one sensitive and quite local parameter: the magnetic hyperfine field (mhf). We have used Augmented Planes Waves plus local orbitals (APW+lo) all-electron method based on the density functional theory and implemented in the WIEN2k code to simulate supercells of Co doped with Cd. The resulting mhf at Cd ions is compared with values from perturbed angular correlation spectroscopy measurements using 111Cd as probe nuclei found in the literature for hcp, fcc, and bcc phases. Up to date, experimental results for mhf at 111Cd for epsilon structure are not available. Calculated mhf and magnetic moments agree well with reported experimental values - tab. 1. From the calculated density of states for each structure, it is possible to investigate the differences in the magnetic exchange interaction at an atomic view

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  • IPEN-DOC 26770

    GOMES, DANIEL de S. . Study of thoria-urania fuel during accidents. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 25th, October 20-25, 2019, Uberlândia, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2019.

    Abstract: In this investigation, nuclear fuel based on mixed ceramic oxides, using (Th–U)O2 as nuclear fuel and zirconium-based alloy as cladding, was simulated. This strategic configuration can achieve improved safety margins because of an enhanced set of thermal and mechanical properties. The Experimental Breeder Reactor built in the 1950s in Idaho introduced the concept that a reactor can generate more fissile material than it consumes. The thorium fuels have a lower cost and should decrease weapon-grade plutonium compared with conventional fuel, UO2. The nuclear characteristic of thorium-232 or U-238 can make a converter into U-233 or Pu-239. However, using thoria fuels can avoid weapon proliferation by reducing plutonium, and it also should reduce radionuclides such as (Np, Am, Cm). This study uses an optimized composition of Th-75% wt and U-25% wt with an enrichment of 19.5%. We studied the behavior using the fuel licensing codes FRAPCON and FRAPTRAN, including many adaptations for the mixed composition choice. The results prove that thoria–urania fuel has a higher performance than pure uranium dioxide fuel during accidents.

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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.