Eventos - Artigos: Recent submissions

  • IPEN-DOC 24023

    GOMES, DANIEL S. . Sensitivity and uncertainty evaluation applied to the failure process of nuclear fuel. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Nuclear power plants must operate with minimal risk. The nuclear power plants licensing process is based on a paired model, combining probabilistic and deterministic approaches to improve fuel rod performance during both steady state and transient events. In this study, performance fuel codes were used to simulate the test rod IFA-650-4, with a burnup of 92 GWd/MTU within a Halden reactor. In a loss-of-coolant test, the cladding failed within 336 s after reaching a temperature of 800 °C. Nuclear systems work with many imprecise values that must be quantified and propagated. These sources were separated by physical models or boundary conditions describing fuel thermal conductibility, fission gas release, and creep rates. These factors change output responses. Manufacturing tolerances show dimensional variations for fuel rods, and boundary conditions within the system are characterized using small ranges that can spread throughout the system. To identify the input parameters that produce output effects, we used Pearson coefficients between input and output. These input values represent uncertainties using a stochastic technique that can define the effect of input parameters on the establishment of realistic safety limits. Random sampling provided a set of runs for independent variables proposed by Wilks' formulation. The number of samples required to achieve the 95th percentile, with 95% confidence, depending on verifying the confidence interval to each output. The FRAPTRAN code utilized a module to reproduce the plastic response, defining the failure limit of the fuel rod.

    Palavras-Chave: boundary conditions; burnup; computerized simulation; f codes; fuel rods; gauss function; loss of coolant; nuclear fuels; performance; probability density functions; reactivity; sensitivity analysis; water cooled reactors

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  • IPEN-DOC 24022

    MONACO, DANIEL F. ; SABUNDJIAN, GAIANE . PCRELAP5 - a visual graphic preprocessor for RELAP5. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The aim of this work is to develop PCRELAP5, a visual preprocessor for RELAP5, reducing time, effort and maintenance costs spent in new projects for RELAP5. This preprocessor allows user to draw new nuclear power plant nodalization in a completely interactive way, and input parameters for each node in a more user-friendly experience. Once parameters are changed on screen, the input cards of RELAP5 code are changed in real time. RELAP5 users will have a tool to reduce time and effort for new studies and existing projects. Therefore, this project proposes to significantly leverage studies related to nuclear accident analysis, making the RELAP5 code more user-friendly. In order to demonstrate this preprocessor capability, the CANON experiment will be used as an example. The PCRELAP5 preprocessor is being developed using Microsoft® Visual Studio® as a Microsoft® Excel® add-in, due to the low cost of distribution and maintenance, and also allowing new RELAP5 projects be leveraged by the MS Excel® flexibility.

    Palavras-Chave: computer graphics; computerized simulation; loss of coolant; nodal expansion method; nuclear power plants; p codes; pwr type reactors; r codes; reactor accident simulation

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  • IPEN-DOC 24021

    ABE, ALFREDO ; GIOVEDI, CLAUDIA; GOMES, DANIEL ; SILVA, ANTONIO T. e ; MUNIZ, RAFAEL O.R. ; MARTINS, MARCELO. Sensitivity assessment of fuel performance codes for loca accident scenario. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: FRAPCON code predicts fuel rod performance in LWR (Light Water Reactor) by modeling fuel responses under normal operating conditions and anticipated operational occurrences; FRAPTRAN code is applied for fuel transient under fast transient and accident conditions. The codes are well known and applied for different purposes and one of the use is to address sensitivity analysis considering fuel design parameters associated to fabrication, moreover can address the effect of physical models bias. The objective of this work was to perform an assessment of fuel manufacturing parameters tolerances and fuel models bias using FRAPCON and FRAPTRAN codes for Loss of Coolant Accident (LOCA) scenario. The preliminary analysis considered direct approach taken into account most relevant manufacturing tolerances (lower and upper bounds) related to design parameters and physical models bias without considering their statistical distribution. The simulations were carried out using the data available in the open literature related to the series of LOCA experiment performed at the Halden reactor (specifically IFA-650.5). The manufacturing tolerances associated to design parameters considered in this paper were: enrichment, cladding thickness, pellet diameter, pellet density, and filling gas pressure. The physical models considered were: fuel thermal expansion, fission gas release, fuel swelling, irradiation creep, cladding thermal expansion, cladding corrosion, and cladding hydrogen pickup. The results obtained from sensitivity analysis addressed the impact of manufacturing tolerances and physical models in the fuel cladding burst time observed for the IFA-650.5 experiment.

    Palavras-Chave: accident-tolerant nuclear fuels; computerized simulation; f codes; fuel rods; fuel-cladding interactions; loss of coolant; sensitivity analysis; transients; water cooled reactors

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  • IPEN-DOC 24020

    LAINETTI, PAULO E.O. . Prospective thorium fuels for future nuclear energy generation. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Palavras-Chave: feasibility studies; historical aspects; nuclear fuels; reactors; reserves; thorium; japan; usa

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  • IPEN-DOC 24019

    STEFANI, GIOVANNI L. de ; MAIORINO, JOSE R. ; MOREIRA, JOAO M. de L.; SANTOS, THIAGO A. dos ; ROSSI, PEDRO C.R.. Feasibility to convert an advanced PWR from UO2 to a mixed (U,Th)O2 core. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: This work presents the neutronics and thermal hydraulics feasibility to convert the UO2 core of the Westinghouse AP1000 in a (U-Th)O2 core, rather than the traditional uranium dioxide, for the purpose of reducing long-lived actinides, especially plutonium, and generates a stock pile of 233U, which could in the future be used in advanced fuel cycles, in a more sustainable process and taking advantage of the large stock of thorium available on the planet and especially in Brazil. The reactor chosen as reference was the AP1000, which is considered to be one of the most reliable and modern reactor of the current Generation III, and its similarity to the reactors already consolidated and used in Brazil for electric power generation. The results show the feasibility and potentiality of the concept, without the necessity of changes in the core of the AP1000, and even with advantages over this. The neutron calculations were made by the SERPENT code. The results provided a maximum linear power density lower than the AP1000, favoring safety. In addition, the delayed neutron fraction and the reactivity coefficients proved to be adequate to ensure the safety of the concept. The results show that a production of about 260 Kg of 233U per cycle is possible, with a minimum production of fissile plutonium that favors the use of the concept in U-Th cycles.

    Palavras-Chave: delayed neutron fraction; feasibility studies; fissile materials; fuel rods; parametric analysis; pwr type reactors; reactor cores; s codes; thermal hydraulics; thorium 232; uranium 233; uranium dioxide

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  • IPEN-DOC 24018

    ESCANHOELA, CORDELIA M.F. ; LIMA, ANA C. de S. ; SABUNDJIAN, GAIANE . Study of the economic viability of the innovative nuclear reactor SMART in Brazil. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The main objective of this study is to evaluate the economic viability of the installation and operation of the innovative System - Integrated Modular Advanced Reactor (SMART) in Brazil. SMART, developed by the Korea Atomic Energy Research Institute (KAERI), is a small and modular Power Water Reactor (PWR), presents electric power of 100 MW and thermal power of 330 MW; it has a passive safety system and integral refrigeration configuration, characteristics that, allied with modularization, simplification and technological improvements, give SMART greater reliability and economy when compared to conventional reactors. SMART presents, in addition to electricity production, the functions of seawater desalination and district heat generation. The research is based on projections of energy demand in the medium and long term with emphasis on electricity and search for the reduction of greenhouse gases. These previsions indicate the need for energy expansion and diversification of the current sources in Brazil, predominantly water sources. The methodology used is based on the cost of electric generation, production capacity and construction time of SMART, adopting the investment model similar to the Angra 3 plant and the use of mirrored costs between the plants. The feasibility of the project was evaluated through the financial criteria: Internal Rate of Return (IRR), Net Present Value (NPV) and Weighted Average Cost of Capital (WACC), whose revenue should be generated through a tariff passed on to the consumer.

    Palavras-Chave: comparative evaluations; cost; economic analysis; feasibility studies; financing; kaeri; performance; pwr type reactors; viability; angra-3 reactor

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  • IPEN-DOC 24017

    NEGRO, MIGUEL L.M. ; DURAZZO, MICHELANGELO ; MESQUITA, MARCO A. de; CARVALHO, ELITA F.U. de ; ANDRADE, DELVONEI A. de . Studies on capacity management for factories of nuclear fuel for research reactors. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The use and the power of nuclear reactors for research and materials testing is increasing worldwide. That implies the demand for nuclear fuel for this kind of reactors is rising. Thus, the production facilities of this kind of fuel need reliable guidance on how to augment their production in order to meet the increasing demand efficiently, safely and keeping good quality. Focus is given to factories that produce plate type fuel elements loaded with LEU U3Si2-Al fuel, which are typically used in nuclear research reactors. Of the various production routes for this kind of fuel, we chose the route which uses hydrolysis of uranium hexafluoride. Raising the capacity of this kind of plants faces several problems, especially regarding safety against nuclear criticality. Some of these problems are briefly addressed. The new issue of the paper is the application of knowledge from the area of production administration to the fabrication of nuclear fuel for research reactors. A specific method for the increase in production capacity is proposed. That method was tested by means of discrete event simulation. The data were collected from the nuclear fuel factory at IPEN. The results indicated the proposed method achieved its goal as well as ways of raising production capacity in up to 50%.

    Palavras-Chave: augmentation; computerized simulation; enriched uranium; iear-1 reactor; nuclear fuels; production; uranium silicides

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  • IPEN-DOC 24016

    REIS, REGIS ; SILVA, ANTONIO T. e . Analysis of the behavior under irradiation of high burnup nuclear fuels with the computer programs FRAPCON and FRAPTRAN. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The objective of this paper is to verify the validity and accuracy of the results provided by programs FRAPCON-3.4a and FRAPTRAN behavior of Pressurized Water Reactors (PWR) fuel rods, in steady conditions at high burnup. To achieve this goal, the results provided by these computer simulations are compared with experimental data available in the database FUMEX III. found that the computer programs used have a good ability to predict the operational behavior of PWR fuel rods in high burnup steady Accident (RIA).

    Palavras-Chave: accuracy; burnup; computerized simulation; f codes; fuel rods; irradiation; nuclear fuels; pwr type reactors; reactivity-initiated accidents; steady-state conditions; transients; uranium oxides; validation; zircaloy 4

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  • IPEN-DOC 24015

    GOMES, DANIEL S. ; MUNIZ, RAFAEL O.R. ; GIOVEDI, CLAUDIA. Improving performance with accident tolerant-fuels. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: After the Fukushima reactor accident, efforts to improve risk management in nuclear operations have included the intensification of research on accident-tolerant fuels (ATFs). In this investigation, the physical properties of recently developed ATFs were compared with those of the current standard fuel, UO2–Zr. The goals for innovative fuel design include a rigorous characterization of the thermal, mechanical, and chemical considerations. The intentions are to lengthen the burnup cycle, raise the power density, and improve safety. Fuels must have a high uranium density—above that supported by UO2—and possess a coating that exhibits better oxidation resistance than Zircaloys. ATFs such as U3Si2, UN, and UC contain a higher uranium density and thermal conductivity than UO2, providing significant benefits. The ideal combination of fuel and cladding must increase performance in a loss-of-coolant accident. However, U3Si2, UN, and UC have a disadvantage; their respective swelling rates are higher than that of UO2. These ATFs also have thermal conductivities approximately four times higher than that of UO2. A study was conducted investigating the hydrogen generated by the oxidation of zirconium alloys in contact with steam using cladding options such as Fe-Cr-Al and silicon carbide. It was confirmed that ferritic alloys offer a better response under severe conditions, because of their mechanical properties as creep rate. The findings of this study indicate that advanced fuels should replace UO2–Zr as the fuel system of choice.

    Palavras-Chave: accident-tolerant nuclear fuels; aluminium; chromium; cladding; comparative evaluations; iron; oxidation; physical properties; swelling; uranium oxides; water cooled reactors; zirconium alloys

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  • IPEN-DOC 24014

    GOMES, DANIEL S. ; SILVA, ANTONIO T. ; ABE, ALFREDO Y. ; MUNIZ, RAFAEL O.R. ; GIOVEDI, CLAUDIA. High density fuels using dispersion and monolithic fuel. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Fuel plates used in high-performance research reactors need to be converted to low-enrichment uranium fuel; the fuel option based on a monolithic formulation requires alloys to contain 6 – 10 wt% Mo. In this case, the fuel plates are composed of the metallic alloy U-10Mo surrounded by a thin zirconium layer encapsulated in aluminum cladding. This study reviewed the physical properties of monolithic forms. The constraints produced during the manufacturing process were analyzed and compared to those of dispersed fuel. The bonding process used for dispersion fuels differs from the techniques applied to foil bonding used for pure alloys. The quality of monolithic plates depends on the fabrication method, which usually involves hot isostatic pressing and the thermal annealing effect of residual stress, which degrades the uranium cubic phase. The preservation of the metastable phase has considerable influence on fuel performance. The physical properties of the foil fuel under irradiation are superior to those of aluminum-dispersed fuels. The fuel meat, using zirconium as the diffusion barrier, prevents the interaction layer from becoming excessively thick. The problem with dispersed fuel is breakaway swelling with a medium fission rate. It has been observed that the fuel dispersed in aluminum was minimized in monolithic forms. The pure alloys exhibited a suitable response from a rate at least twice as much as the fission rate of dispersions. The foils can support fissile material concentration combined with a reduced swelling rate.

    Palavras-Chave: aluminium; cladding; dispersion nuclear fuels; foils; fuel elements; fuel plates; irradiation; molybdenum alloys; physical properties; swelling; uranium alloys; zirconium

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  • IPEN-DOC 24013

    GOMES, DANIEL S. ; SILVA, ANTONIO T. ; ABE, ALFREDO Y. ; MUNIZ, RAFAEL O.R. ; GIOVEDI, CLAUDIA. Simulation of accident-tolerant U3Si2 fuel using FRAPCON code. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The research on accident-tolerant fuels (ATFs) increased after the Fukushima event. This benefitted risk management in nuclear operations. In this investigation, the physical properties of the materials being developed for the ATF program were compared with those of the standard UO2–Zr fuel system. The research efforts in innovative fuel design include rigorous characterization of thermal, mechanical, and chemical assessment, with the objectives of making the burnup cycle longer, increasing power density, and improving safety performance. Fuels must reach a high uranium density—above that supported by UO2—and possess coating that exhibits better oxidation resistance than Zircaloy. The uranium density and thermal conductivity of ATFs, such as U3Si2, UN, and UC, is higher than that of UO2; their combination with advanced cladding provides possible fuel–cladding options. An ideal combination of fuel and cladding must increase fuel performance in loss-of-coolant scenarios. The disadvantages of U3Si2, UN, and UC are their swelling rates, which are higher than that of UO2. The thermal conductivities of ATFs are approximately four times higher than that of UO2. To prevent the generation of hydrogen due to oxidation of zirconium-based alloys in contact with steam, cladding options, such as ferritic alloys, were studied. It was verified that FeCrAl alloys and SiC provide better response under severe conditions because of their thermophysical properties. The findings of this study indicate that U3Si2 and the FeCrAl fuel cladding concept should replace UO2–Zr as the fuel system of choice.

    Palavras-Chave: accident-tolerant nuclear fuels; aluminium alloys; chromium alloys; cladding; comparative evaluations; computerized simulation; f codes; fuel rods; iron alloys; loss of coolant; steady-state conditions; swelling; thermal conductivity; thermal expansion; transients; uranium carbides; uranium nitrides; uranium silicides; zircaloy

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  • IPEN-DOC 24012

    GIOVEDI, CLAUDIA; ABE, ALFREDO ; MUNIZ, RAFAEL O.R. ; GOMES, DANIEL de S. ; SILVA, ANTONIO T. e ; MARTINS, MARCELO R.. Modification of fuel performance code to evaluate iron-based alloy behavior under loca scenario. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Accident tolerant fuels (ATF) has been studied since the Fukushima Daiichi accident in the research efforts to develop new materials which under accident scenarios could maintain the fuel rod integrity for a longer period compared to the cladding and fuel system usually utilized in Pressurized Water Reactors (PWR). The efforts have been focused on new materials applied as cladding, then iron-base alloys appear as a possible candidate. The aim of this paper is to implement modifications in a fuel performance code to evaluate the behavior of ironbased alloys under Loss-of-Coolant Accident (LOCA) scenario. For this, initially the properties related to the thermal and mechanical behavior of iron-based alloys were obtained from the literature, appropriately adapted and introduced in the fuel performance code subroutines. The adopted approach was step by step modifications, where different versions of the code were created. The assessment of the implemented modification was carried out simulating an experiment available in the open literature (IFA-650.5) related to zirconium-based alloy fuel rods submitted to LOCA conditions. The obtained results for the iron-based alloy were compared to those obtained using the regular version of the fuel performance code for zircaloy-4. The obtained results have shown that the most important properties to be changed are those from the subroutines related to the mechanical properties of the cladding. The results obtained have shown that the burst is observed at a longer time for fuel rods with iron-based alloy, indicating the potentiality of this material to be used as cladding with ATF purposes.

    Palavras-Chave: accident-tolerant nuclear fuels; cladding; computerized simulation; f codes; fuel rods; iron alloys; loss of coolant; performance; pwr type reactors; stainless steel-348

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  • IPEN-DOC 24011

    MUNIZ, RAFAEL O.R. ; GIOVEDI, CLAUDIA; ABE, ALFREDO ; GOMES, DANIEL S. ; AGUIAR, AMANDA A.; SILVA, ANTONIO T. . Assessment of uranium dioxide fuel performance with the addition of beryllium oxide. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The Fukushima Daiichi accident in 2011 pointed the problem related to the hydrogen generation under accident scenarios due to the oxidation of zirconium-based alloys widely used as fuel rod cladding in water-cooled reactors. This problem promoted research programs aiming the development of accident tolerant fuels (ATF) which are fuels that under accident conditions could keep longer its integrity enabling the mitigation of the accident effects. In the framework of the ATF program, different materials have been studied to be applied as cladding to replace zirconium-based alloy; also efforts have been made to improve the uranium dioxide thermal conductivity doping the fuel pellet. This paper evaluates the addition of beryllium oxide (BeO) to the uranium dioxide in order to enhance the thermal conductivity of the fuel pellet. Investigations performed in this area considering the addition of 10% in volume of BeO, resulting in the UO2-BeO fuel, have shown good results with the improvement of the fuel thermal conductivity and the consequent reduction of the fuel temperatures under irradiation. In this paper, two models obtained from open literature for the thermal conductivity of UO2- BeO fuel were implemented in the FRAPCON 3.5 code and the results obtained using the modified code versions were compared. The simulations were carried out using a case available in the code documentation related to a typical pressurized water reactor (PWR) fuel rod irradiated under steady state condition. The results show that the fuel centerline temperatures decrease with the addition of BeO, when compared to the conventional UO2 pellet, independent of the model applied.

    Palavras-Chave: beryllium oxides; comparative evaluations; computerized simulation; f codes; fuel pellets; fuel rods; nuclear fuels; performance; pwr type reactors; steady-state conditions; thermal conductivity; uranium dioxide

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  • IPEN-DOC 24010

    FREITAS, ARTUR C. ; CARVALHO, ELITA F.U. . Study of the densification of uranium-erbium system. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The sintering process of UO2-Er2O3 pellets has been investigated because of its importance in the nuclear industry and the complex behavior during sintering. The present study includes the development of nuclear fuel for power reactor in order to increase the efficiency of the fuel trough longer refueling intervals. The erbium is indicated for longer cycles, which means less stops to refueling and less waste. In this work, we studied the use of erbium oxide by varying the concentrations in the range of 1-9.8%, which was added to UO2 powder through mechanical mixing, aiming to check the rate of densification and a possible sintering blockage. The powders were pressed and sintered at 1700ºC under hydrogen atmosphere. The results show a sintering blockage in the UO2-Er2O3 system that occurs in the range of 1500-1700ºC temperature. Dilatometric tests indicate a retraction of 21.87% when used Er2O3 at 1% mass concentration. This shrinkage is greater than is observed with higher concentrations or even without the addition of the burnable poison, providing us with a better degree of incorporation of the element erbium, resulting in pellets with density suitable for use as nuclear fuel.

    Palavras-Chave: burnable poisons; cross sections; density; erbium oxides; flow blockage; fuel densification; fuel pellets; nuclear fuels; powders; reactor fueling; sintering; uranium oxides

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  • IPEN-DOC 24009

    GOMES, DANIEL S. ; ABE, ALFREDO Y. ; MUNIZ, RAFAEL O.R. ; GIOVEDI, CLAUDIA. Analysis of UO2-BEO fuel under transient using fuel performance code. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Recent research has appointed the need to replace the classic fuel concept, used in light water reactors. Uranium dioxide has a weak point due to the low thermal conductivity, that produce high temperatures on the fuel. The ceramic composite fuel formed of uranium dioxide (UO2), with the addition of beryllium oxide (BeO), presents high thermal conductivity compared with UO2. The oxidation of zirconium generates hydrogen gas that can create a detonation condition. One of the preferred options are the ferritic alloys formed of iron-chromium and aluminum (FeCrAl), that should avoid the hydrogen release due to oxidation. In general, the FeCrAl alloys containing 10–20Cr, 3–5Al, and 0–0.12Y in weight percent. The FeCrAl alloys should exhibit a slow oxidation kinetics due to chemical composition. Resistance to oxidation in the presence of steam is improved as a function of the content of chromium and aluminum. In this way, the thermal and mechanical properties of the UO2-BeO-10%vol, composite fuel were coupled with FeCrAl alloys and added to the fuel codes. In this work, we examine the fuel rod behavior of UO2-10%vol-BeO/FeCrAl, including a simulated transient of reactivity. The fuels behavior shown reduced temperature with UO2-BeO/Zr, UO2-BeO/FeCrAl also were compared with UO2/Zr system. The case reactivity initiated accident analyzed, reproducing the fuel rod called VA-1 using UO2/Zr alloys and compared with UO2-BeO/FeCrAl.

    Palavras-Chave: aluminium alloys; beryllium oxides; chromium alloys; composite materials; computerized simulation; coupling; f codes; fuel rods; iron alloys; mechanical properties; nuclear fuels; thermodynamic properties; transients; uranium dioxide; zirconium

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  • IPEN-DOC 24008

    MENDES, LUIZ F.F. ; CONTI, THADEU N. . Study of production of fuel pellets for a reactor. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Nowadays the electrical energy was been used much on society. A method for getting electricity is through nuclear power plants, this power plant uses fission that occurs inside the UO2 pellets to generate thermal energy that will be transform into electric. The pellets production was made from enriched UF6 uses some techniques of reprocessing UF6 gas to UO2 powder. This reprocessing process done by wet route (Ammonium Diuranate ADU or Ammonium Uranium Carbonate AUC) or by dry route (Fluidized bed or GECO). With getting of UO2 powder is forwarded to metallurgy where this powder is compacted in cylindrical matrix so that powder take the desired shape, this green pellets are full of the empty spaces (porosity) for this it is sent to the sintering. The sintering consists of a joint of these particles of powders by means of the heating of this green pellets, coming arrive the melting temperature, the UO2 molecules melting each other so decrease the porosity and increase the density. For the production of fuel pellets the process all most used is wed route by means the AUC ,this process arrive created for replace the ADU because the AUC is a process where less rework for the pore geometry is required compared to DUA. The fluidized bed process is more used in small samples however, for a large amount it becomes unfeasible, moreover the dry route process require more robust materials because of the generation of HF that is highly corrosive and cannot used the UNH (uranyl nitrate hexahydrate) used for recycle materials discarded in manufacturing.

    Palavras-Chave: adu; auc; fluidized beds; fuel elements; fuel pellets; powder metallurgy; powders; production; pwr type reactors; sintering; uranium dioxide

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  • IPEN-DOC 24007

    GOMES, DANIEL S. ; TEIXEIRA, ANTONIO S. . Simulating fuel behavior under transient conditions using fraptran and uncertainty analysis using DAKOTA. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Although regulatory agencies have shown a special interest in incorporating best estimate approaches in the fuel licensing process, fuel codes are currently licensed based on only the deterministic limits such as those seen in 10CRF50, and therefore, may yield unrealistic safety margins. The concept of uncertainty analysis is employed to more realistically manage this risk. In this study, uncertainties were classified into two categories: probabilistic and epistemic (owing to a lack of pre-existing knowledge in this area). Fuel rods have three sources of uncertainty: manufacturing tolerance, boundary conditions, and physical models. The first step in successfully analyzing the uncertainties involves performing a statistical analysis on the input parameters used throughout the fuel code. The response obtained from this analysis must show proportional index correlations because the uncertainties are globally propagated. The DAKOTA toolkit was used to analyze the FRAPTRAN transient fuel code. The subsequent sensitivity analyses helped in identifying the key parameters with the highest correlation indices including the peak cladding temperature and the time required for cladding failures. The uncertainty analysis was performed using an IFA-650-5 fuel rod, which was in line with the tests performed in the Halden Project in Norway. The main objectives of the Halden project included studying the ballooning and rupture processes. The results of this experiment demonstrate the accuracy and applicability of the physical models in evaluating the thermal conductivity, mechanical model, and fuel swelling formulations.

    Palavras-Chave: boundary conditions; computerized simulation; d codes; data covariances; f codes; fuel rods; fuel-cladding interactions; nuclear fuels; probabilistic estimation; swelling; thermal conductivity; thermal expansion; transients

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  • IPEN-DOC 24006

    PEREIRA, IRACI M. ; MORAES, DAVI A. ; BUENO, ELAINE I.. Monitoring system for an experimental facility using GMDH methodology. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: This work presents a Monitoring System developed based on the GMDH - Group Method of Data Handling methodology to be used in an Experimental Test Facility. GMDH is a combinatorial multi-layer algorithm in which a network of layers and nodes is generated using a number of inputs from the data stream being evaluated. The GMDH network topology has been traditionally determined using a layer by layer pruning process based on a pre-selected criterion of what constitutes the best nodes at each level. The traditional GMDH method is based on an underlying assumption that the data can be modeled by using an approximation of the Volterra Series or Kolmorgorov-Gabor polynomial. The Fault Test Experimental Facility was designed to simulate a PWR nuclear power plant and is composed by elements that correspond to the pressure vessel, steam generator, pumps of the primary and secondary reactor loops. The nuclear reactor core is represented by an electrical heater with different values of power. The experimental plant will be fully instrumented with sensors and actuators, and the data acquisition system will be constructed in order to enable the details of the temporal analysis of process variables. The Fault Test Experimental Facility can be operated to generate normal and fault data. These failures can be added initially with small magnitude, and their magnitude being increasing gradually in a controlled way. The database will interface with the plant supervisory system SCADA (Supervisory Control and Data Acquisition) that provides the data through standard interface.

    Palavras-Chave: algorithms; artificial intelligence; computerized simulation; failures; g codes; polynomials; pwr type reactors; reactor cores; s codes; test facilities; volterra integral equations

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  • IPEN-DOC 24005

    MORAES, DAVI A. ; PEREIRA, IRACI M. . Neural networks used to monitor an experimental test workbench. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: This work presents the application of neural networks in an experimental workbench. This bench was developed with the purpose of conducting real time tests and data acquisition. The method applied for this work allowed to generate faulty data in a gradual and controlled way through the binary combination of double action valves. Using the SCADA application (Supervisory Control and Data Acquisition), it became possible to acquire data for analysis in Matlab / Simulink software. This bench has two reservoirs: a reservoir that has sensors for recording pressure and temperature variables for later analysis, and another reservoir that has level sensors. Four models were used to develop the respective practical experiments. In the first model, it was possible to perform all practical tests of the plant, as well as mechanical changes like repositioning of some mechanical components, piping, sensors and electrovalves. In the second model, it was noticed that the positioning of the flow meter, located after the pump output, prevented a good measurement of the flow variable. In the third model, it was perceived that the number of failures initially adopted, made the data too confusing for the neural network analysis. In the last model, it was possible to obtain a performance of 96.6% of hits after the reconfiguration for 4 controlled faults.

    Palavras-Chave: automation; bench-scale experiments; control rooms; data acquisition systems; failures; neural networks; pwr type reactors; real time systems; sensitivity analysis

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  • IPEN-DOC 24004

    SILVESTRE, LARISSA J.B. ; SABUNDJIAN, GAIANE . Development and application of the PCRELAP5 – Data Calculation Program for RELAP 5 Code. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: Nuclear accidents in the world led to the establishment of rigorous criteria and requirements for nuclear power plant operations by the international regulatory bodies. By using specific computer programs, simulations of various accidents and transients likely to occur at any nuclear power plant are required for certifying and licensing a nuclear power plant. Some sophisticated computational tools have been used such as the Reactor Excursion and Leak Analysis Program (RELAP5), which is the most widely used code for the thermo-hydraulic analysis of accidents and transients in nuclear reactors in Brazil and worldwide. A major difficulty in the simulation by using RELAP5 code is the amount of information required for the simulation of thermal-hydraulic accidents or transients. Thus, for those calculations performance and preparation of RELAP5 input data, a friendly mathematical preprocessor was designed. The Visual Basic for Application (VBA) for Microsoft Excel demonstrated to be an effective tool to perform a number of tasks in the development of the program. In order to meet the needs of RELAP5 users, the RELAP5 Calculation Program (Programa de Cálculo do RELAP5 – PCRELAP5) was designed. The components of the code were codified; all entry cards including the optional cards of each one have been programmed. An English version for PCRELAP5 was provided. Furthermore, a friendly design was developed in order to minimize the time of preparation of input data and errors committed by users. The final version of this preprocessor was successfully applied for Safety Injection System (SIS) of Angra 2.

    Palavras-Chave: computer calculations; p codes; r codes; reactor accident simulation; thermal hydraulics; transients; angra-2 reactor

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  • IPEN-DOC 24003

    BRAZ FILHO, FRANCISCO A.; RIBEIRO, GUILHERME B.; SABUNDJIAN, GAIANE ; CALDEIRA, ALEXANDRE D.. Comparison between RELAP5 versions for a two-phase natural circulation analysis. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: RELAP5 is one of the most used numerical tools to predict thermal-hydraulic and neutronic phenomena in nuclear reactors. RELAP5-3D is the latest version of this software family, but RELAP5-mod3 is still widely used in Brazilian research institutes and it is also used as benchmark for several nuclear applications. Among these applications, the use of passive heat transfer mechanisms, such as natural circulation, has drawn attention of several studies, especially after the Fukushima-Daiichi accident. Considering this aforementioned aspect, this study proposes a comparison of RELAP5-3D and RELAP5-mod3 versions, focusing on a two-phase natural circulation loop. For comparison purposes, an experimental data set is part of the analysis. Results showed that during the single-phase regime, the temperature difference between versions is negligible. However, when the two-phase flow regime takes place, different wavelengths and amplitudes of flow instabilities were obtained for each version. When compared to the experimental data set, the RELAP5-3D version provided the best prediction results.

    Palavras-Chave: comparative evaluations; computerized simulation; differential equations; natural convection; r codes; thermal hydraulics; two-phase flow

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  • IPEN-DOC 24002

    SANTOS, THIAGO A. dos; MAIORINO, JOSE R.; STEFANNI, GIOVANNI L. de . A thermal hydraulic analisys in PWR reactors with UO2 or (U-Th)O2 fuel rods employing a simplified code. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: In order to project a nuclear reactor, the neutronic calculus must be validated, so that its thermal limits and safety parameters are respected. Considering this issue, this research aims to evaluate the APTh thermal limits. This PWR is a project develope composed of Uranium and Thorium oxide mixed (U,Th)O2. For this purpose, a simplified, although conservative, code was developed in a MATLAB environment named hydraulics Code-Mixed Oxide Thorium”. This code provides axial and radial temperature distribution, as well as DNBR distribution over the hottest channel of the reactor core. Moreover, it brings other hydraulic quantities, such as pressure drop over the fuel rod, considering any fuel proportion of (U,Th)O2.The software uses basic laws of conservation of mass, momentum and energy, it also calculates the thermal conduction equation, considering the thermal conductive coefficie finite elements method was used. Furthermore, the proportion of 36% of UO2 was used to evaluate the temperature over the fuel rod and DNBR minimum in three burn conditions: beginning, middl program has proven to be efficient in every condition and the results evidenced that the APTh an initial analysis, has its thermal limits within the recommended security parameters.

    Palavras-Chave: finite element method; fuel rods; heat transfer; m codes; mixed oxide fuels; nucleate boiling; pwr type reactors; s codes; thermal hydraulics; thorium oxides; thorium oxides; thorium oxides; uranium dioxide

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  • IPEN-DOC 24001

    PINHO, PRISCILA G.M. ; ROCHA, MARCELO S. . Effect of high doses of gamma radiation on thermophysical properties of ZrO2 nanofluids in aqueous base. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Palavras-Chave: aqueous solutions; gamma radiation; heat transfer; nanofluidics; nanoparticles; physical properties; radiation doses; radiation effects; viscosity; zirconium oxides

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  • IPEN-DOC 24000

    BIATY, FLAVIA P. ; ROCHA, MARCELO da S. ; OLIVEIRA, OTAVIO L. de . Technical and economic feasibility study for the reactivation of the integral test facility of IPEN/CNEN Nuclear Engineering Center. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 22-27, 2017, Belo Horizonte, MG. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Energia Nuclear, 2017.

    Abstract: The Integral Test Facility of Nuclear Engineering Center (CEN/IPEN/CNEN-SP), known as “Loop 70”, is a semi-industrial thermal-hydraulic test facility and can operate as a BWR (Boiling Water Reactor) or a PWR (Pressurizing Water Reactor) mode. Designed and built in the 1980’s, it is currently disabled. The experimental circuits (“test loop”) are facilities that reproduce the thermohydraulic and fluiddynamic conditions that occur inside a reactor and are used to simulate the practical reality which it is not possible to be obtained through mathematical models. In this context, this research project aims the development of a Business Plan to analyze the technical and economic feasibility related to the reactivation of the facility. This methodology (adapted to the government sector) is a decision-making tool that will offer a wide perspective of the project, set the guidelines and actions that will define the future of the facility and provide a general rule to make investments on it. This paper presents the historic aspects to better understand the Loop 70’s current situation. It also presents information about similar facilities around the world, services that can be offered (thermal-hydraulics parameters measurements, equipment qualification and transient analysis due accident situations), results of the strategic analysis (SWOT) performed, specific goals for each critical success or failure factor of the facility, financial aspects related to the reactivation and an overview of the facility’s perspectives.

    Palavras-Chave: economic analysis; feasibility studies; financing; historical aspects; investment; market; nuclear engineering; regeneration; risk assessment; test facilities; thermal hydraulics

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  • IPEN-DOC 23460

    KIBRIT, E. ; AQUINO, A.R. ; MELLO, A.M.; NASCIMENTO, P.T.S.. Sustainable operations in nuclear research reactors - a bibliographical study. In: EUROPEAN RESEARCH REACTOR CONFERENCE, May 14-18, 2017, Rotterdam, Netherlands. Proceedings... Brussels, Belgium: European Nuclear Society, 2017. p. 1-15.

    Abstract: Sustainability is gaining prominence in the area of operations management. By means of a bibliographical research, we identified in literature sustainable operations carried out by operating organizations of nuclear research reactors. The methodology applied consisted in gathering material, descriptive analysis, selection of analytical categories and evaluation of the material collected. The collection of material was performed by a search made on academic and nuclear databases, with keywords structured for the subject of the research. The collected material was analysed and analytical categories on the theme sustainable operations were established. The evaluation of the collected material resulted in references accepted for the study, classified according to the pre-established analytical categories. The results were significant. From then on, a theoretical review on the topic under study was structured, based on pre-defined analytical categories. Thus, we were able to identify gaps in the literature and propose new studies on the subject.

    Palavras-Chave: bibliographies; radioactive waste management; reactor operation; recycling; research reactors; sustainability

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  • IPEN-DOC 23332

    SUGIMOTO, H.Y. ; REIS, S.L. ; MUCCILLO, E.N.S. . Obtenção e caracterização da perovsquita BiFeO3 / Preparation and characterization of BiFeO3. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1419-1428.

    Abstract: O BiFeO3 tem despertado muita atenção por sua característica multiferróica, com coexistência de ordenamento magnético e polarização ferroelétrica. Materiais multiferróicos com acoplamento magnetoelétrico são promissores para aplicações em dispositivos na microeletrônica e na spintrônica. Neste trabalho, o BiFeO3 foi preparado pelo método convencional de reação em estado sólido. A sinterização dos compactos foi realizada em diferentes condições de temperatura, tempo de patamar e variação da taxa de aquecimento. Melhores resultados de densidade aparente foram obtidos em sinterização a 900ºC por 0,5 h ao ar. A difração de raios X evidenciou uma estrutura cristalina romboédrica tipo perovsquita. Dois eventos endotérmicos foram identificados por análise térmica diferencial. O pico endotérmico a 830ºC deve corresponder à temperatura de Curie, enquanto o de temperatura mais baixa a uma transformação de fase. A microestrutura apresenta modo de fratura preferencial transgranular. Esses resultados permitiram identificar um roteiro otimizado para a obtenção do BiFeO3 pelo método convencional.

    Palavras-Chave: ceramics; perovskite; ferroelectric materials; thermal analysis

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  • IPEN-DOC 23331

    SOUZA, J.P. ; MUCCILLO, E.N.S. . Efeito da adição de óxido de európio na composição de fases e na condutividade elétrica da zircônia-10% mol escândia / Effect of the europium oxide addition in the phase composition and eletrical conductivity in the zirconium-10% mol scandia. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1360-1369.

    Abstract: A solução sólida de zircônia-escândia apresenta alta condutividade iônica e tem potencial para utilização em células a combustível de óxido sólido que operam em temperaturas intermediárias (500-700ºC). Entretanto, a transição reversível de fase cúbica-romboédria que ocorre em ~600ºC é um fator de impedimento para suas aplicações tecnológicas. Neste trabalho, óxido de európio em baixos teores foi adicionado à zircônia-10% mol escandia para fins de estabilização da fase cúbica à temperatura ambiente. As amostras foram preparadas por reação em estado sólido a 1500ºC/5 h e a estabilização da fase cúbica for investigada por difração de raios X, calorimetria exploratória diferencial e espectroscopia de impedância. A estabilização total da fase cúbica ocorreu para teores a partir de 1% mol Eu2O3, e a condutividade iônica a baixas temperaturas aumentou por ~2 ordens de grandeza.

    Palavras-Chave: zirconium; scandium; europium oxides; additives; phase transformations; electric conductivity

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  • IPEN-DOC 23328

    SILVA, A.C. ; ARAUJO, M.S. ; COSTA E SILVA, D.L. ; MELLO-CASTANHO, S.R.H. . Vitrificação de metais de transição: A estabilidade química no sistema quaternário Na2O-CaO-SiO2-RxOy. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 2166-2177.

    Abstract: A estabilização de resíduos industriais contendo metais de transição por meio de processos de vitrificação é de relevância tanto para a saúde pública como a ambiental. O sucesso destas ações depende de que material resultante apresente a necessária estabilidade química frente a meios corrosivos. Uma vez dispersos na massa vítrea fundida, os metais de transição podem assumir coordenações que lhes permite tomar parte na estrutura vítrea resfriada. Desta forma os óxidos destes metais (Cr, Ni, Cu, Zn) considerados genericamente como RxOy, interagem com os óxidos do sistema CaO:Na2O:SiO2, resultando no sistema quaternário CaO:Na2O:SiO2:RxOy, no qual composições adequadamente formuladas podem apresentar apreciável resistência química. No presente trabalho uma composição de matriz vítrea CaO:Na2O:SiO2 (10:30:60 em massa percentual) recebeu adições de metais de transição RxOy provenientes de resíduos industriais (Lama Galvânica) entre 10 e 40 % em massa, de modo a iniciar a exploração da região na qual a incorporação de RxOy no sistema CaO:Na2O:SiO2:RxOy incremente a resistência química. Tal estudo visa iniciar a construção de uma adequada ferramenta para a formulação de vidros contendo metais de transição. Os vidros foram obtidos por fusão (1500°C) em cadinhos de alumina seguida de “Quenching” em molde de aço. A caracterização dos vidros foi realizada por difração de raios-x (DRX), por infravermelho na transformada de Fourier (FTIR) e resistência hidrolítica. Os resultados indicaram alterações na distribuição entre as espécies de sílica Q3 e Q2 na rede vítrea e o aumento da estabilidade química em função da incorporação do RxOy.

    Palavras-Chave: vitrification; industrial wastes; stabilization; sustainable development

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  • IPEN-DOC 23327

    SILVA, D.Y.B. ; REIS, S.L. ; MUCCILLO, R. ; MUCCILLO, E.N.S. . Propriedades elétricas da perovsquita Bi2/3Cu3Ti4O12 / Electrical properties of perovskite Bi2/3Cu3Ti4O12. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1429-1438.

    Abstract: Materiais da família ACu3Ti4O12 tem sido amplamente estudados devido suas propriedades especiais, tais como permissividade elétrica gigante e baixa tangente de perda. Poucos trabalhos ainda tentam buscar uma relação entre as propriedades dielétricas e as características microestruturais. Um dos destaques desta família é o Bi2/3Cu3Ti4O12 (BCTO). Neste trabalho foi estudada a dependência das propriedades dielétricas e alguns aspectos da microestrutura do BCTO em função de seu processamento. O óxido misto foi preparado pelo método de mistura dos óxidos reagentes seguida de reação em estado sólido. O BCTO foi sinterizado na temperatura de 950°C com tempos de patamar variando entre 1-12 h. Os principais resultados evidenciam a possibilidade de produção de cerâmicas densas independentemente do tempo de sinterização e com fase perovsquita característica. A densidade máxima foi obtida para tempo de 2 h. O modo característico de fratura do BCTO é misto (transgranular e intergranular), com grãos poligonais. A permissividade elétrica atingiu valor máximo (3.908 a 1 kHz e temperatura de 96ºC) para sinterização a 950ºC por 3 h.

    Palavras-Chave: bismuth compounds; copper compounds; ceramics; dielectric materials; permittivity; titanates; oxygen compounds; oxides; mixtures

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  • IPEN-DOC 23326

    SILVA, P.C.M.; CARVALHO, F.M.S.; GUEDES-SILVA, C.C. . Estudo de cerâmicas de alumina com adições de Ba0,1Sr0,9TiO3 / Study of alumina ceramics with additions of Ba0,1Sr0,9TiO3. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1714-1721.

    Abstract: Esse trabalho visa avaliar o efeito da adição de Ba0,1Sr0,9TiO3 na sinterização, microestrutura e propriedades mecânicas de cerâmicas de alumina. Composições foram preparadas pela moagem da alumina contendo 1 a 10% em massa de Ba0,1Sr0,9TiO3. Após moagem e prensagem as pastilhas foram sinterizadas a 1400°C por 2 horas ao ar. As amostras foram caracterizadas quanto à densidade e porosidade aparentes, pelo método de Arquimedes. A microestrutura foi analisada por difratometria de raios X, microscopia eletrônica de varredura por elétrons retroespalhados. A dureza e a tenacidade à fratura foram caracterizadas pelo método da impressão Vickers. Os resultados mostraram que a densidade e porosidade aparente foram favorecidas durante o processo de sinterização para amostras com menores teores de Ba0,1Sr0,9TiO3. As análises obtidas por difração de raios X mostraram a presença fases cristalinas secundárias, indicando que o aditivo utilizado reagiu com a alumina durante o processo de sinterização. Altos valores de dureza (de até 13 GPa) e tenacidade à fratura (de até 5 MPa.m1/2) puderam ser atingidos quando pequenas quantidades do aditivo foram utilizados.

    Palavras-Chave: aluminium oxides; ceramics; microstructure; mechanical properties

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  • IPEN-DOC 23324

    REIS, S.L. ; MUCCILLO, E.N.S. . Influência do galato de estrôncio na composição de fases e nas propriedades elétricas do galato de lantânio contendo estrôncio e magnésio / Influence of the strontium gallate on the phase composition and the electrical properties of strontium- and magnesium-doped lanthanum gallate. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1378-1387.

    Abstract: A perovsquita galato de lantânio com substituições parciais de estrôncio e magnésio é um candidato promissor para eletrólito sólido de células a combustível de óxido sólido em temperaturas intermediárias, devido sua elevada condutividade iônica, insignificante condutividade eletrônica e uma excelente estabilidade química em ampla faixa de pressão parcial de oxigênio. Neste trabalho, a composição La0,9Sr0,1Ga0,8Mg0,2O3- com diferentes teores de galato de estrôncio, SGO, foi preparada pelo método convencional de reação em estado sólido, e a influência deste aditivo nas propriedades do material foram investigadas. Amostras com diferentes teores de SGO apresentam densidades superiores a 98%, quando sinterizadas a 1350°C/5 h, e o aumento do teor do aditivo promoveu uma pequena diminuição da densidade. Amostras com tamanho médio de grãos micrométricos foram obtidas. O SGO inibiu o crescimento dos grãos, e o aumento no teor do aditivo promoveu a diminuição da resistividade elétrica dos grãos e contornos de grão.

    Palavras-Chave: electrolytes; perovskites; lanthanum; gallium oxides; additives; ceramics; oxides; mixtures

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  • IPEN-DOC 23318

    OLIVEIRA, G.L. ; ANDREOLI, M. ; ORTIZ, N. ; GENOVA, L.A. . Síntese de nanopartículas de titanato de sódio e comparação de seu desempenho em relação ao TiO2 na fotocatálise do corante azul de metileno / Synthesis of sodium titanate nanoparticles and comparison of its performance in relation to TiO2 in the photocatalysis of methylene blue dye. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017.

    Abstract: A utilização de processos oxidativos avançados (POA’s) para tratamento de efluentes industriais vem recebendo muita atenção. A fotocatálise heterogênea é o mais promissor dos POA’S em desenvolvimento. TiO2 e seus compostos semicondutores despertam grande interesse devido sua estabilidade térmica e química e baixo custo. Neste estudo é apresentada metodologia para a síntese hidrotérmica de nanopartículas de titanato de sódio (TNS). Este material, juntamente com um TiO2 comercial (Degussa-P25), foi caracterizado por DRX, área superficial específica e tamanho e distribuição de poros (BET-BJH), e microscopia eletrônica de varredura (FEG-SEM). Destaca-se a elevada área superficial (320 m2/g) e elevado volume de poros (0,62 cm3/g) do TNS. Ensaios de degradação fotocatalítica mostraram que o TNS adsorveu praticamente todo o corante da solução, não se podendo avaliar seu potencial fotocatalisador. Quanto ao P-25 não se observou adsorção do corante, e com a irradiação UV a degradação foi de 55% após 400 minutos de irradiação.

    Palavras-Chave: oxidation; titanium oxides; sodium; titanates; photocatalysis

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  • IPEN-DOC 23403

    FERNANDES, S.M.C. ; CORREA, O.V. ; SOUZA, J.A. de ; RAMANATHAN, L.V. ; ANTUNES, R.A.; OLIVEIRA, M.C.L. de. Coatings to protect spent aluminium-clad research reactor fuel during extended wet storage. In: EUROPEAN RESEARCH REACTOR CONFERENCE, May 14-18, 2017, Rotterdam, Netherlands. Proceedings... Brussels, Belgium: European Nuclear Society, 2017. p. 1-10.

    Abstract: Conversion coatings have been used to protect aluminium surfaces from corroding. Hence use of this type of coating was considered to protect the aluminium cladding of spent research reactor fuels during extended wet storage. A conventional chemical process, as opposed to an electrochemical process, is preferred due to the shape of the fuel and its high radioactivity. In this context hydrotalcite (HTC) and boehmite coatings were considered. This paper presents the results of further development of HTC coatings, from the stand point of eventually being able to coat highly radioactive spent fuels using remote handling equipment. More specifically: (a) preparation of HTC coatings from different baths on AA 6061 alloy surfaces that were given pre-treatments to simulate spent fuel surfaces; (b) characteristics of the HTC coatings as a function of bath temperature; (c) corrosion behaviour of HTC coated AA 6061 alloy; (d) results of field studies in which dummy fuel elements, consisting of Al alloy plates coated with HTC from different baths (with or without post coating treatments), were immersed in the IEA-R1 reactor’s spent fuel basin for periods of up to 2 years. This study demonstrates that Al surfaces can be coated with HTC using an allroom temperature process. The field tests revealed marked increase in corrosion resistance of HTC coated plates. The mechanism of corrosion protection is discussed and a mock-up arrangement to remotely handle dummy-fuel elements to pre-treat, coat with HTC and post-treat is presented.

    Palavras-Chave: spent fuels; wet storage; coatings; aluminium; cladding; research reactors; corrosion resistance

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  • IPEN-DOC 23304

    GROSSO, R.L. ; MUCCILLO, E.N.S. ; CASTRO, R.H.R.. Entalpia de formação e estabilidade de fases da zircônia-escândia / Enthalpy of formation and phase stability of zirconia-scandia. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1388-1397.

    Abstract: Soluções sólidas de zirconia-escândia (ScZ) têm atraído atenção para aplicações como eletrólitos sólidos em células a combustível de óxido sólido devido a combinação de suas propriedades elétricas e mecânicas. No entanto, a estabilidade de fases é o principal fator limitante para sua aplicação tecnológica. Cerâmicas policristalinas de ScZ apresentam um número relativamente grande de polimorfos. Contudo, há uma carência de dados termodinâmicos deste sistema para permitir um controle de fase abrangente visando otimizar suas propriedades. Nesse trabalho, a entalpia de formação da ScZ dentro de faixa molar de 0 a 20% de Sc2O3 é determinada a partir da combinação de valores de energia de superfície com dados de entalpia de dissolução de óxidos obtidos por calorimetria de dissolução de óxidos em alta temperatura. São reportados valores de entalpia de formação, os quais são fundamentais para o entendimento da estabilidade de fases, para cinco polimorfos: monoclínica (m), tetragonal (t), cúbica (c) e romboédrica (β e γ).

    Palavras-Chave: scandium; zirconium; formation heat; enthalpy; phase stability

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  • IPEN-DOC 23300

    FUJIMOTO, T.G. ; MUCCILLO, E.N.S. . Influência do galato de lantânio na densificação e na microestrutura da zircônia estabilizada com ítria / Influence of lanthanum gallate on densification and microstructure of yttria-stabilized zirconia. In: CONGRESSO BRASILEIRO DE CERAMICA, 61., 04-07 de junho, 2017, Gramado, RS. Anais... 2017. p. 1485-1493.

    Abstract: A zircônia estabilizada com ítria (YSZ) vem sendo muito estudada para fins de aplicações, devido sua boa estabilidade química e térmica, além da alta condutividade iônica. Outro condutor iônico que merece destaque é o galato de lantânio com substituições de estrôncio e magnésio em aplicações como eletrólito sólido em células a combustível de óxido sólido em temperatura de operação intermediária (800°C – 1000°C). Neste trabalho, foi investigado o efeito da adição do galato de lantânio na densificação e na microestrutura da YSZ. O aditivo foi introduzido em teores de 10 e 20% em massa pelo método de mistura de óxidos seguido de sinterização a 1450°C Os resultados obtidos mostraram que com o aumento do teor de aditivo houve diminuição na densidade relativa das amostras de ~99% (YSZ) até ~92% (YSZ com 20% aditivo). Os perfis de difração de raios X mostraram como fase predominante a cúbica tipo fluorita, característica da YSZ. Análises feitas por dilatometria mostraram que as amostras contendo aditivo retraíram cerca de 27% até 1500ºC. O tamanho médio de grãos aumentou com conforme o aumento no teor de aditivo, que ficou confinado nos contornos de grão da YSZ.

    Palavras-Chave: zirconium; yttrium; microstructure; lanthanum; gallic acid

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  • IPEN-DOC 23402

    CONTURBIA, GIOVANNI R. ; DURAZZO, MICHELANGELO . Study of thermomechanical treatment for manufacturing UAlx/Al dispersion targets. In: EUROPEAN RESEARCH REACTOR CONFERENCE, May 14-18, 2017, Rotterdam, Netherlands. Proceedings... Brussels, Belgium: European Nuclear Society, 2017.

    Abstract: Uranium aluminide/aluminum (UAlx-Al) targets are widely used in research reactors to produce 99Mo radioisotopes as a fission product of 235U. The 99Mo decays into 99mTc, which is the most suitable radionuclide for single-photon emission computed tomography image technique. The UAlx-Al targets were fabricated according to the picture frame technique, which employs hot rolling of such dispersion. The UAl2 is the starting uranium compound used as fissile material in the dispersion. During the manufacturing of targets some solid state reactions take place between UAl2 and Al matrix producing UAl3 and UAl4. The specification claims that the finished target must be free of UAl2 in its composition, because UAl2 is harder to dissolve in radiochemical processing. This work aims to develop a thermomechanical treatment that can consume all UAl2 initially presented in the dispersion. The dilatometry and x-ray diffraction with Rietveld refinement were used to obtain a final optimized thermomechanical treatment for the UAlx/Al dispersion targets.

    Palavras-Chave: uranium; thermomechanical treatments; aluminium; radioisotopes; dispersions

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  • IPEN-DOC 23325

    SILVA, LEANDRO G. da ; SAMAD, RICARDO E. ; VIEIRA JUNIOR, NILSON D. ; ROSSI, WAGNER de . Alteração da cor no aço ASTM F138 por meio de irradiação com laser de femtossegundo / Color change in metals by means of regular nanostructures produced by femtosecond laser pulses. In: ABM WEEK; CONGRESSO ANUAL DA ABM, 71.; ENCONTRO NACIONAL DE ESTUDANTES DE ENGENHARIA METALURGICA, DE MATERIAIS E DE MINAS, 16., 26-30 de setembro, 2016, Rio de Janeiro, RJ. Anais... São Paulo: Associação Brasileira de Metalurgia, Materiais e Mineração, 2016. p. 128-134.

    Abstract: Neste trabalho, foram estudados os efeitos da irradiação de uma superfície polida do aço inoxidável tipo ASTM F138 com laser de pulsos ultracurtos. As irradiações foram realizadas variando-se a velocidade de varredura do laser, ou seja, a taxa de sobreposição espacial de pulsos. Foi observado que após a irradiação houve uma visível mudança na coloração da amostra. Também foi verificado que com o aumento da taxa de sobreposição de pulsos a superfície tendeu a tornar-se preta, ou seja, absorvedora de luz. Com essa técnica, pode-se realizar marcações com alto contraste sem que haja formação de camadas de óxidos, nitretos ou alterações microestruturais no metal, o que é importante para um material com a precisão que um implante exige.

    Palavras-Chave: lasers; pulses; color; stainless steels; surfaces; nanostructures

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  • IPEN-DOC 23243

    CAMPELLO, F.A. ; IZIDORO, J.C. ; GHILHEN, S.N. ; FUNGARO, D.A. . Estudo da imobilização de elementos tóxicos presentes nas cinzas de carvão por meio do tratamento com agentes imobilizadores. In: INTERNATIONAL WORKSHOP - ADVANCES IN CLEANER PRODUCTION, 6th, May 24-26, 2017, São Paulo, SP. Proceedings... 2017. p. 1-9.

    Abstract: A capacidade de imobilização de elementos tóxicos presentes nas cinzas de carvão usando orgânosilano (OS) e surfactante (SF) como agentes imobilizadores foi determinada por experimentos em batelada. As cinzas de carvão utilizadas no estudo foram coletadas na Usina Termelétrica de Figueira, localizada na cidade de Figueira, Estado do Paraná. Primeiramente, a influência da relação massa de cinzas/volume de água na concentração dos elementos nos lixiviados foi avaliada. Posteriormente, as capacidades de imobilização de elementos tóxicos usando os diferentes agentes imobilizadores, o pH e a condutividade dos lixiviados foram determinados. Observou-se uma significativa redução da concentração dos elementos para todas as amostras de lixiviados das cinzas tratadas com OS. As reduções de concentração usando OS foram de 89%, 77%, 42% e 11% para Cr, Mo, As e Se, respectivamente. No ensaio das cinzas tratadas com SF, a redução de concentração nos lixiviados estava acima de 60% para todos os elementos. Esses resultados mostram que tanto o orgânosilano, como o surfactante podem ser usados como agentes imobilizadores para retenção de elementos tóxicos presentes nas cinzas de carvão.

    Palavras-Chave: coal; fly ash; surfactants; solidification; organic silicon compounds; silanes

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  • IPEN-DOC 23236

    BERTOLINI, T.C.R. ; GHILHEN, S.N. ; FUNGARO, D.A. . Avaliação de métodos de peletização de material zeolítico de cinzas de carvão. In: INTERNATIONAL WORKSHOP - ADVANCES IN CLEANER PRODUCTION, 6th, May 24-26, 2017, São Paulo, SP. Proceedings... 2017. p. 1-10.

    Abstract: A avaliação de métodos diferentes de peletização de material zeolítico sintetizado a partir de cinzas de carvão foi descrita neste trabalho. As cinzas leves de carvão utilizadas na síntese da zeólita por tratamento hidrotérmico alcalino foram coletadas na Usina Termelétrica Jorge Lacerda, localizada no Estado de Santa Catarina, Brasil, o maior complexo termelétrico a carvão da América Latina. O material de partida e a zeólita sintetizada na forma de pó foram caracterizados em termos da composição química, composição mineralógica e capacidade de troca catiônica. Os peletes foram formados a partir da mistura de material zeolítico com um ou mais agentes aglutinantes e adição de água deionizada. A massa plástica obtida foi moldada manualmente na forma de esferas na faixa de tamanho entre 4 mm e 7 mm. As metodologias diferentes de peletização do material zeolítico foram avaliadas por meio da determinação da capacidade de troca catiônica dos produtos obtidos, trabalhabilidade, resistência física e estabilidade em água. O material zeolítico peletizado obtido pelo método melhor avaliado neste estudo foi selecionado para futura aplicação como material adsorvente no tratamento de efluente.

    Palavras-Chave: coal; fly ash; pellets; zeolites; energy demand; hydrothermal systems; adsorbents; pelletizing

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  • IPEN-DOC 23151

    ANGELO, EDVALDO; BARBOZA, RODOLFO A.R.; ANDRADE, DELVONEI A. de ; ANGELO, GABRIEL. Estudo numérico da inclusão de geradores de turbulência em canal com transferência de calor. In: CONFERENCIA IBEROAMERICANA EN SISTEMAS, CIBERNETICA E INFORMATICA, 15., 05-08 de julio, 2016, Orlando, USA. Anales... 2016. p. 50-57.

    Abstract: O artigo apresenta simulação numérica computacional de um escoamento em um canal de seção transversal retangular havendo transferência de calor entre as paredes e o fluido. O canal representa parte de um trocador de calor de placas de pequeno porte para aplicação em dispositivos eletrônicos. Foram realizadas simulações em que a geometria do canal recebeu alterações como a adição de geradores de turbulência objetivando o aumento da taxa de transferência de calor. As alterações consistiram na inclusão de ranhuras na parede e também a adoção de vários elementos geradores de turbulência na entrada do canal, em um total de quatro tipos geométricos distintos. Em uma das geometrias do gerador de turbulência, dois parâmetros foram variados e os resultados das simulações comparadas. As simulações computacionais foram realizadas utilizando o software comercial ANSYS CFX®. Os resultados indicaram a intensificação da transferência de calor nas geometrias modificadas e também a elevação da perda de carga do escoamento. É indicada a geometria mais adequada entre as propostas apresentadas.

    Palavras-Chave: heat transfer; computerized simulation; fluid mechanics; rectangular configuration; forced convection

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  • IPEN-DOC 23126

    GIMENEZ-ALVENTOSA, V.; ANTUNES, P.C.G. ; BALLESTER, F.; VIJANDE, J.. Graphical interface for designing geometries and processing DICOM images for PENELOPE / Interfaz gráfica para el diseño de geometrías y procesamiento de imágenes DICOM para PENELOPE. In: GLOBAL MEDICAL ENGINEERING PHYSICS EXCHANGES/PAN AMERICAN HEALTH CARE EXCHANGES, April 04-09, 2016, Madrid, Spain. Proceedings... New York, NY, USA: IEEE, 2016.

    Abstract: One of he most dificult steps when preparing a Monte Carlo calculation is the design of their geometries. Such process is an error-prone, timeconsuming, and complex step for any simulation in the field of medical physics. The software VoxelMages has been developed to help the user in this complex task. It allows to design arbitrary geometries and to process DICOM image files for simulations with the general-purpose Monte Carlo code PENELOPE. Its main characteristics are described in the following.

    Palavras-Chave: geometry; monte carlo method; computer codes; computerized simulation

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  • IPEN-DOC 23106

    ROSSATTI, CARLOS ; CASTANHO, DAVI ; IZIDORO, JULIANA de C. ; FUNGARO, DENISE A. . Otimização da síntese de zeólita na-a de elevada pureza obtida a partir de cinzas volantes de carvão. In: CONGRESSO BRASILEIRO DE CARVAO MINERAL, 5., 29 de maio - 01 de junho, 2017, Criciúma, SC. Anais... 2017.

    Abstract: A queima do carvão mineral para a produção de energia elétrica gera diversos tipos de resíduos. Entre os resíduos gerados, encontram-se os seguintes tipos de cinzas: leves e pesadas. No Brasil, as cinzas volantes e leves correspondem a 85% do total de cinzas produzidas, enquanto que as cinzas pesadas correspondem a somente 15%. Uma das formas de mitigar o impacto ambiental proveniente da disposição inadequada das cinzas é o desenvolvimento de metodologia para a produção de material de valor agregado, como por exemplo, zeólita de elevada pureza, o qual possibilita inúmeras aplicações em diversos ramos de atividade. O objetivo deste trabalho foi otimizar a síntese de zeólita de elevada pureza do tipo Na-A a partir das cinzas volantes de carvão por meio da redução do tempo total do processo. A síntese foi realizada em duas etapas: a primeira consistiu na fusão alcalina das cinzas volantes e a segunda no tratamento hidrotérmico. Diferentes tempos de tratamento hidrotérmico foram testados até a obtenção de zeólita com elevado grau de pureza com uma redução de 4 h na segunda etapa da síntese. Os materiais sintetizados foram caracterizados pelas técnicas de difratometria de raios X e microscopia eletrônica de varredura. Os resultados de difração de raios X indicaram que os materiais sintetizados apresentaram fases cristalinas idênticas para a zeólita do tipo Na- A quando comparadas ao banco de dados. As microfotografias dos nanomateriais sintetizados apresentaram estruturas na forma cúbica, típicas desse tipo de material. Concluiu-se por meio do presente estudo que é possível reduzir o tempo total da síntese de duas etapas, enquanto é mantido o alto grau de pureza da zeólita Na-A produzida a partir das cinzas, sendo que dessa forma a obtenção desse material alternativo possa ser mais vantajosa do ponto de vista de economia de recursos.

    Palavras-Chave: fly ash; synthesis; zeolites; impurities; coal; ashes

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  • IPEN-DOC 23105

    IBANEZ-ROSELLO, B.; BAUTISTA-BALLESTEROS, J.A.; BONAQUE, J.; ANTUNES, P.C.G. ; PEREZ-CALATAYUD, J.; GONZALEZ-SANCHIS, A.; LOPEZ-TORRECILLA, J.; BRUALLA-GONZALEZ, L.; GARCIA-HERNANDEZ, T.; VICEDO-GONZALEZ, A.; GRANERO, D.; SERRANO, A.; BORDERIA, B.; SOLERA, C.; ROSELLO, J.. Process map for FMEA risk analysis implementation by TG-100 of AAPM in Total Skin Electron Irradiation (TSEI) technique. In: GLOBAL MEDICAL ENGINEERING PHYSICS EXCHANGES/PAN AMERICAN HEALTH CARE EXCHANGES, April 04-09, 2016, Madrid, Spain. Proceedings... New York, NY, USA: IEEE, 2016.

    Abstract: Total Skin Electron Irradiation (TSEI) is a radiotherapy treatment which involves irradiating the entire body surface as homogeneously as possible. It is composed of an extensive multi-step technique in which quality management requires high consumption of resources. The TG-100 proposes a new perspective of quality management in radiotherapy, presenting a systematic method of risk analysis throughout the global flow of the stages through the patient. With the intention of applying this method, a multidisciplinary team of people was involved in the procedure that produced the process map (PM). This PM can be useful for those centers that intend to implement the TSEI technique. This is the first stage of a full risk analysis performed in a reference center in this treatment technique.

    Palavras-Chave: skin; whole-body irradiation; therapy; risk assessment; radiotherapy; failure mode analysis

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  • IPEN-DOC 23094

    WETTER, NIKLAUS U. ; JIMENEZ-VILLAR, E.; GHIEL, JULIA M. ; BUTZBACH, FELIX ; TAYRA, VICTOR . Optimizing grain size distribution in Nd:YVO4 powder pellets for random laser action with high efficiency. In: CLARKSON, W.A. (Ed.); SHORI, RAMESH K. (Ed.) SOLID STATE LASERS XXVI: TECHNOLOGY AND DEVICES, January 30 - February 02, 2017, San Francisco, CA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2017. (SPIE Proceedings Series, 10082). DOI: 10.1117/12.2256600

    Abstract: We demonstrate a volumetric random laser with an optical efficiency of 15%. We use a 1.33 mol% Nd:YVO4 crystal, grind it and mix the particles into ten different size distributions with mean particle sizes ranging from approximately 10 micrometers to 100 micrometers. After pressing into pellets, each of the ten groups has its transport mean free path calculated from the distribution spectra and experimentally measured by means of its backscattering cone. We then calculate the fill fractions of each sample. The pellets are diode-pumped at 806.5 nm. Linewidth narrowing and output power are measured as a function of absorbed pump power. We demonstrate that the smaller particles, trapped between large particles, serve as gain centers whereas the large particles control the light diffusion into the sample. By optimizing diffusion and gain we achieve high slope efficiency.

    Palavras-Chave: neodymium lasers; crystals; randomness; lasers; powders; grain size; scattering; particles

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  • IPEN-DOC 23069

    MUNITA, CASIMIRO S. ; OLIVEIRA, CLAUDIA A.; SULLASI, HENRY L.; AMARAL, ALENCAR M.; CARVALHO, PATRICIA R. . Estudo da mobilidade logística a partir da caracterização química da cerâmica do sítio capim em Araripina, Pernambuco, BR. In: CONGRESSO LATINO-AMERICANO DE ARQUEOMETRIA, 5., 07-11 de novembro, 2016, São Paulo, SP. Anais... São Paulo, SP: Sociedade de Arqueologia Brasileira, 2016.

    Palavras-Chave: ceramics; neutron activation analysis; archaeological sites; cultural objects; historical aspects; chemical analysis; multivariate analysis; cluster analysis

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  • IPEN-DOC 23080

    MIRANDA, CAIO da S. ; IZIDORO, JULIANA de C. ; GUILHEN, SABINE N. ; FUNGARO, DENISE A. . Avaliação da remoção de elementos metálicos tóxicos presentes no efluente do aterro de cinzas de carvão mineral usando zeólita sintética. In: CONGRESSO BRASILEIRO DE CARVAO MINERAL, 5., 29 de maio - 01 de junho, 2017, Criciúma, SC. Anais... 2017.

    Abstract: A produção de energia elétrica usando carvão mineral gera diferentes tipos de resíduos que precisam ser dispostos adequadamente para não causar impactos ambientais significativos. Diversas técnicas têm sido adotadas para que haja a redução da lixiviação dos elementos metálicos tóxicos presentes nas cinzas. O preparo do aterro de cinzas usando camadas de calcário e argila foi usado como alternativa por uma usina termelétrica a carvão localizada na região sul do Brasil. A utilização das cinzas leves para a síntese de materiais de valor agregado, por outro lado, também pode amenizar esse problema pelo fato de reduzir a quantidade de resíduo a ser disposto. O objetivo do presente trabalho foi avaliar a remoção de elementos tóxicos presentes no efluente de um aterro de cinzas usando zeólitas sintetizadas a partir dos próprios resíduos de combustão do carvão. Os ensaios foram realizados em batelada empregando-se 10 g de zeólita/L e 20 g de zeólita/L. A comparação entre as concentrações dos elementos do efluente antes e após o contato com a zeólita, bem como as análises de pH e condutividade foram realizadas. Os resultados indicaram que cromo e arsênio foram os principais elementos tóxicos presentes no efluente do aterro de cinzas que apresentavam concentração acima do permitido pela legislação ambiental. Após o tratamento com a zeólita, a concentração de arsênio no efluente reduziu de 1,09 mg/L para 0,275 mg/L na dose de 10 g/L e ficou abaixo do limite de detecção do equipamento (< 0,01) na dose de 20 g/L. Para o cromo, não houve alteração da concentração, enquanto uma elevação dos valores de pH e condutividade do efluente foi observada. O presente estudo sugere que a zeólita de cinzas leves de carvão podem ser usadas como forma de tratamento de efluentes contendo elevados níveis de arsênio.

    Palavras-Chave: coal; ashes; residues; sanitary landfills; waste water; zeolites

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  • IPEN-DOC 23042

    FARIAS, WALNICE de F.C.; COUTINHO, ANTONIA V. da S.; COUTINHO, JUCELINO da S.; SILVA, PAULO S.C. da ; LUCAS, FABIO de O.. Avaliação da concentração de metais em amostras do pericarpo e mesocarpo do fruto da castanheira. In: ENCONTRO AMAZONICO DE AGRARIAS, 8., 26 de junho - 01 de julho, 2016, Belém, PA. Anais... 2016. p. 42-47.

    Abstract: A castanha-do-pará, é muito utilizada na alimentação humana, sendo produzida por uma planta da família Lecythidaceae, espécie Bertholettia excelsa. É uma planta símbolo do bioma amazônico, sendo encontrada em todos os estados da região. Os frutos da castanha-do-pará são denominados ouriços e nele estão contidos de 12 a 25 sementes. As sementes são ricas em proteínas e lipídeos, apresentando ainda uma quantidade considerável de selênio. Por ser um produto da agricultura extrativista, os estudos são bastante escassos, principalmente no que se refere à pós colheita e aproveitamento dos resíduos do processo. Assim, nesse trabalho, teve-se por objetivo determinar os constituintes inorgânicos, e avaliar a concentração dos elementos Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sc, Se, Sm, Th, Yb e Zn por análise por ativação neutrônica. A relevância dessas análises é justificada pela necessidade de gerar informações que possam contribuir no aproveitamento de resíduos da castanha-do-pará.

    Palavras-Chave: nuts; residues; neutron activation analysis; chemical analysis; amazon river

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  • IPEN-DOC 23036

    CERAVOLO, FLAVIO E. ; ROCHA, MARCELO da S. ; OLIVEIRA, FABIO B.V. de ; ANDRADE, DELVONEI A. de . Numerical simulation of isothermal upward two-phase flow in a vertical tube of annular section. In: JOURNEYS IN MULTIPHASE FLOWS, 4th, March 27-31, 2017, São Paulo, SP. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2017.

    Abstract: A numerical simulation of a vertical, upward, isothermal two-phase flow of air bubbles and water in an annular channel applying Computational Fluid Dynamics code (CFD) was carried out. The simulation considers an Eulerian frame, with two-fluid model, specific correlations for turbulence model considering the dispersion and bubble induction turbulence. The work intends to assess whether the code represents the physical phenomenon accurately by comparing the simulation results with experimental data obtained from literature. The annular channel adopted has equivalent hydraulic diameter of 19.1 mm, where the outer pipe has an internal diameter of 38.1 mm and inner rod 19.1 mm. To represent this geometry, a three-dimensional mesh was generated with 960000 elements, after a mesh independence study. The void fraction distribution, taken radially to the flow section is the main parameter analyzed besides interfacial area concentration, interfacial gas velocity, diameter and distribution of bubbles.

    Palavras-Chave: isothermal processes; bubbles; two-phase flow; annular space; fluid flow; fluid mechanics; computer codes

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  • IPEN-DOC 22129

    FRANCO, EGBERTO G. ; LINARDI, MARCELO ; COLOSIO, MARCO A.. Ethanol fuel cell: new electrocatalysts systems. In: SAE BRASIL CONGRESS AND EXHIBIT; CONGRESSO E EXPOSICAO INTERNACIONAIS DA TECNOLOGIA DA MOBILIDADE, 14., 22-24 de novembro, 2005, São Paulo, SP. Proceedings... Warrendale, PA: SAE International, 2005. (SAE Technical Paper 2005-01-4078). DOI: 10.4271/2005-01-4078

    Abstract: Ethanol fuel cell has major drawbacks to be overcame. Electrocatalysts systems are one of the major concerns in the development of ethanol fuel cells. In this work we synthesized two different systems: PtRuDy and PtU. PtRuDy shows electroactivities similar to Pt3Sn, that is pointed out as the best catalyst for ethanol oxidation. PtU shows a promise result when operated with ethanol and after this with hydrogen and oxygen again. It is well established that electrocatalysts systems as PtRu when operated with alcohols these systems shows a huge degradation when operating with hydrogen again. PtRuDy system shows 46% of degradation while operating with ethanol and turning back to hydrogen. PtU system shows no degradation at all after operating with ethanol 1.0 mol L-1 and turning to hydrogen again.

    Palavras-Chave: fuel cells; electrocatalysts; ethanol fuels

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  • IPEN-DOC 22414

    FRANCO, EGBERTO G.; DANTAS FILHO, PAULO L.; RIBEIRO, CARLOS E.R.; BURANI, GERALDO F.; LINARDI, MARCELO . Proton exchange membrane fuel cell catalyst: synthesis and characterization. In: INTERNATIONAL FUEL CELL SCIENCE, ENGINEERING AND TECHNOLOGY CONFERENCE, 6th, June 16-18, 2008, Denver, Colorado, USA. Proceedings... 2008. p. 1-6.

    Abstract: Fuel cells are a promising technology to deal with energy sustainability, especially for mobility purposes the Proton Exchange Membrane Fuel Cell and hydrogen produced from biomass could be coupled to overcome the amount of CO2 emissions. In order to improve fuel cells performances the search for new electrocatalysts has a great importance in this technology the challenge for a fuel cell catalyst that is less poisoned by CO is one of the most important field in low temperature fuel cell developments that use alcohol and hydrocarbons as primary fuels. In this work PtSm, PtTb, PtDy, PtU, PtRuMo and PtRuDy systems have been synthesized by the colloid method, investigated by the following techniques: X-rays fluorescence analysis (XFA), X-rays powder diffraction (XRD), X-rays photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), cyclic voltammetry (CV) and polarization curves (Exi). The results obtained in this work shows that PtRuMo is the best choice for direct methanol oxidation. For direct ethanol oxidation the higher activity was found in PtRuDy system. PtU system was investigated and showed an interesting behaviour in ethanol oxidation. After two cycles of H2/O2 and ethanol/O2 the catalyst was able to reach the initial figures on hydrogen/oxygen oxidation which means that no degradation of the catalyst was indentified.

    Palavras-Chave: proton exchange membrane fuel cells; fuel cells; electrocatalysts; synthesis

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  • IPEN-DOC 22701

    SENNA, ROQUE M. de ; LINARDI, MARCELO ; CASSIANO, DOUGLAS A.; SANTOS, IVAN ; MOTA, HENRIQUE de S. ; JERONIMO, ROSIMEIRE A.. Mathematical modeling of a 500 We power module composed by a PEM fuel cell combined with a DC-DC enhanced potential output converter. In: INTERNATIONAL CONFERENCE ON INTEGRATED MODELING AND ANALYSIS IN APPLIED CONTROL AND AUTOMATION, 6th, September 19-21, 2012, Wien, Austria. Proceedings... 2012.

    Abstract: This work presents the development of a mathematical modeling of a 500 We PEMFC fuel cell stack (MCC500) system combined with a dc-dc enhanced potential output converter. The MCC500 was developed at IPEN (Nuclear and Energy Research Institute) and the company Electrocell, using only Brazilian technology. Mathematical developments and modeling have been performed, relying on experimental data collected at IPEN laboratory. The first step was to prepare an electrical system (pre-design) for the proposed model, which included the MCC500 parameters, like: membrane ohmic resistance, activation resistance, electric double layer capacitance, open circuit potential, as well as DC-DC converter parameters, like: inductor and transistor switching frequency. Using the obtained parameters and a linear differential equation system with some mathematical manipulations, an electrical system model was determined. Simulations experiments demonstrated that the system was very stable. This toll contribution showed to be very important to generate useful potential for practical purposes, increasing the overall system electrical efficiency.

    Palavras-Chave: fuel cells; mathematical models; proton exchange membrane fuel cells; energy efficiency

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  • IPEN-DOC 23927

    OLIVEIRA, EDUARDO S. ; SAMAD, RICARDO E. ; VIEIRA JUNIOR, NILSON D. ; ROSSI, WAGNER de . Ablação seletiva de filme fino de TiN depositado sobre um substrato de WC. In: ABM WEEK; CONGRESSO ANUAL DA ABM, 71.; ENCONTRO NACIONAL DE ESTUDANTES DE ENGENHARIA METALURGICA, DE MATERIAIS E DE MINAS, 16., 26-30 de setembro, 2016, Rio de Janeiro, RJ. Anais... São Paulo: Associação Brasileira de Metalurgia, Materiais e Mineração, 2016.

    Abstract: Devido à possibilidade de se remover quantidades muito pequenas de material de cada vez, a ablação seletiva por laser tem se mostrado um método muito eficaz para remoção de finas camadas de materiais depositados sobre um substrato. Neste trabalho, um laser de femtossegundo foi utilizado para remoção de um filme fino de nitreto de titânio (TiN) depositado sobre um substrato de carboneto de tungstênio (WC), configuração comum em pastilhas de usinagem mecânica, objetivando fornecer um método eficiente para tal processo. Os limiares de ablação do filme e do substrato foram determinados, evidenciando a problemática do trabalho, remover um filme com limiar maior que o substrato. Um sistema de controle de espectrometria de emissão atômica induzida por laser (LIBS) foi testada, com a intenção de controlar em tempo real, a espécie do material ablacionado, mostrando-se muito eficiente. Os parâmetros do laser bem como da varredura de usinagem ainda estão sendo testados para definir a viabilidade do processo.

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  • IPEN-DOC 23903

    SCAGLIUSI, SANDRA R. ; CARDOSO, ELIZABETH C.L. ; LUGAO, ADEMAR B. . Radiation effects on crosslinking of butyl rubber compounds. In: TMS ANNUAL MEETING AND EXHIBITION, 146th, February 26 - March 2, 2017, San Diego, CA, USA. Proceedings... 2017.

    Abstract: When butyl rubbers are subjected to high energy radiation, they form easy free radicals that initiate various chemical reactions. These reactions alter the molecular distribution of irradiated rubbers by crosslinking or scission affect their physical and mechanical properties. This work aims to the analysis of effect induced by -exposure on the crosslinking density in butyl rubbers by swelling measurements accomplished before and after irradiation at 25, 50, 100 and 200 kGy, with further evaluation of crosslinking density accomplished by Flory-Rehner equation; this is a proper procedure for the qualification of radiation resistance. It can be noticed that changes in material structure was due to build-up of new three-dimensional network in studied rubbers. Changes in crosslinking density of butyl rubber compounds emphasize that degradation mechanism is strongly influenced by gamma-radiation doses higher than 50 kGy, since chain scission process predominates over crosslinking reaction.

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  • IPEN-DOC 23896

    JORGE, ANA E.S.; CAMPOS, CAROLINA P.; FREITAS, ANDERSON Z. de ; BAGNATO, VANDERLEI S.. Photodynamic therapy induces epidermal thickening in hairless mice skin: an optical coherence tomography assessment. In: IZATT, JOSEPH A. (Ed.); FUJIMOTO, JAMES G. (Ed.); TUCHIN, VALERY V. (Ed.) OPTICAL COHERENCE TOMOGRAPHY AND COHERENCE DOMAIN OPTICAL METHODS IN BIOMEDICINE, 18th, February 01, 2014, San Francisco, CA, USA. Proceedings... Bellingham, WA, USA: International Society for Optics and Photonics, 2014. p. 89343N-1 - 89343-3. (SPIE Proceedings Series, 8934). DOI: 10.1117/12.2040443

    Abstract: Photodynamic therapy (PDT) promotes skin improvement according to many practitioners, however the immediately in vivo assessment of its response remains clinically inaccessible. As a non-invasive modality, optical coherence tomography (OCT) has been shown a feasible optical diagnostic technique that provides images in real time, avoiding tissue biopsies. For this reason, our investigation focused on evaluates the PDT effect on a rodent model by means of OCT. Therefore, a normal hairless mouse skin has undergone a single-session PDT, which was performed with topical 5- aminolevulinic acid (ALA) cream using a red (630 nm) light emitting diode (LED) which reached the light dose of 75 J/cm2. As the optical imaging tool, an OCT (930 nm) with axial resolution of 6.0 microns in air was used, generating images with contact to the mouse skin before, immediately after, 24 hours, and 2 weeks after the correspondent procedure. Our result demonstrates that, within 24 hours after ALA-PDT, the mouse skin from the PDT group has shown epidermal thickness (ET), which has substantially increased after 2 weeks from the treatment day. Moreover, the skin surface has become evener after ALA-PDT. Concluding, this investigation demonstrates that the OCT is a feasible and reliable technique that allows real-time cross-sectional imaging of skin, which can quantify an outcome and predict whether the PDT reaches its goal.

    Palavras-Chave: tomography; optical systems; coherence length; mice; skin; thickness; aminolevulinic acid; epidermis; carcinomas; in vivo; animal tissues

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  • IPEN-DOC 23888

    SOUSA, MARCELO V.P.; PRATES, RENATO ; KATO, ILKA T. ; SABINO, CAETANO P. ; YOSHIMURA, TANIA M. ; SUZUKI, LUIS C. ; MAGALHAES, ANA C.; YOSHIMURA, ELISABETH M.; RIBEIRO, MARTHA S. . Inhomogeneity in optical properties of rat brain: a study for LLLT dosimetry. In: HAMBLIN, MICHAEL R. (Ed.); ARANY, PRAVEEN R. (Ed.); CARROLL, JAMES D. (Ed.) MECHANISMS FOR LOW-LIGHT THERAPY, 8th, February 02, 2013, San Francisco, CA, USA. Proceedings... Bellingham, WA, USA: International Society for Optics and Photonics, 2013. p. 856905-1 - 856905-6. (SPIE Proceedings Series, 8569). DOI: 10.1117/12.2002836

    Abstract: Over the last few years, low-level light therapy (LLLT) has shown an incredible suitability for a wide range of applications for central nervous system (CNS) related diseases. In this therapeutic modality light dosimetry is extremely critical so the study of light propagation through the CNS organs is of great importance. To better understand how light intensity is delivered to the most relevant neural sites we evaluated optical transmission through slices of rat brain point by point. We experimented red (λ = 660 nm) and near infrared (λ = 808 nm) diode laser light analyzing the light penetration and distribution in the whole brain. A fresh Wistar rat (Rattus novergicus) brain was cut in sagittal slices and illuminated with a broad light beam. A high-resolution digital camera was employed to acquire data of transmitted light. Spatial profiles of the light transmitted through the sample were obtained from the images. Peaks and valleys in the profiles show sites where light was less or more attenuated. The peak intensities provide information about total attenuation and the peak widths are correlated to the scattering coefficient at that individual portion of the sample. The outcomes of this study provide remarkable information for LLLT dose-dependent studies involving CNS and highlight the importance of LLLT dosimetry in CNS organs for large range of applications in animal and human diseases.

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  • IPEN-DOC 23890

    XAVIER, CESAR C. ; MOTTA, CLAUDIO C.. A DC design of an X-band traveling-wave tube. In: INTERNATIONAL MICROWAVE AND OPTOELECTRONICS CONFERENCE, August 04-07, 2013, Rio de Janeiro, RJ. Proceedings... Piscataway, NJ: IEEE, 2013. DOI: 10.1109/imoc.2013.6646550

    Abstract: In this paper a dc design procedure of a X-band traveling-wave tube is described. This procedure consists in determine the geometry of the electron gun, the periodic permanent magnetic and the electron collector. It was found that an electron gun with a 0.26 μPerv, 9.1 kV, 225 mA and 0.6 mm beam radius without electrostatic beam control was suitable for this design. The PPM, constructed with samarium-cobalt magnetics shown a good agreement with theoretical design. Finally a three stage depressed collector, to recover part of nonused electron energy and improve the overall electronic efficiency of TWT, is presented. The simulations were run with Particle-incell Studio.

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  • IPEN-DOC 23887

    SILVA, ROBSON K.B. e ; MOTTA, CLAUDIO C.. Design and simulation of a 1.3 GHz input klystron cavity. In: INTERNATIONAL MICROWAVE AND OPTOELECTRONICS CONFERENCE, August 04-07, 2013, Rio de Janeiro, RJ. Proceedings... Piscataway, NJ: IEEE, 2013. DOI: 10.1109/imoc.2013.6646555

    Abstract: This paper presents a sequence of steps to begin the project of a cylindrical reentrant klystron cavity for 1.3 GHz. One analytical method and different CAD tools such as SUPERFISH and 3D eigenmode solver have been used for designing the cavity. The external coupling problem of the cavity is also discussed and is proposed a technique to get the critical coupling.

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  • IPEN-DOC 23886

    SENE, FRANK F. ; SANTOS, VINICIUS O.; MOTTA, CLAUDIO C.. Synthesis and characterization of Ni-Mo sintered alloy foils for microwave tube manufacturing. In: INTERNATIONAL MICROWAVE AND OPTOELECTRONICS CONFERENCE, August 04-07, 2013, Rio de Janeiro, RJ. Proceedings... Piscataway, NJ: IEEE, 2013. DOI: 10.1109/imoc.2013.6646471

    Abstract: The Ni-Mo composite alloy, to be used in microwave vacuum tube manufacturing, was prepared from metal powders previously homogenized, pressed and sintered at 1200oC by induction heating. The Ni-Mo sintered discs were annealed at 1150oC for 20min, and submitted to the roller process in 5 cycles to obtain a thin foil with 0.10 mm of thickness, for brazing process adopted to join the cathode components. The samples were submitted to scanning electron microscopy (SEM) coupled to energy dispersive spectroscopy analysis (EDS) to characterize the composition and microstructure. X-ray diffraction (XRD) was performed to determine the crystalline structure and energy dispersive X-ray fluorescence spectroscopy (EDX) was performed to determine the chemical composition and the homogeneity of the composite alloy.

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  • IPEN-DOC 23883

    PRETTO, A. ; IZIDORO, J.C. ; GATTI, L.V. ; CORREIA, C.S.C. ; MARTINEWSKI, A. ; BASSO, L.S. ; BORGES, V.F. ; ROSSATI, C. ; MILLER, J.B.; CROTWELL, A.; TANS, P.. Analysis of the influence of co2 concentration and others external factors on the N2O quantification. In: MEETING ON CARBON DIOXIDE, OTHER GREENHOUSE GASES AND RELATED TRACERS MEASUREMENT TECHNIQUES, 17th, June 10-13, 2013, Beijing, China. Proceedings... 2013.

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  • IPEN-DOC 23882

    POLITANO, R. . Nitriding modelling in nanoscale. In: INTERNATIONAL CONFERENCE ON MATHEMATICAL MODELLING IN PHYSICAL SCIENCES, 1st, September 3-7, 2012, Budapest, Hungary. Proceedings... Bristol, UK: IOP Publishing, 2013. p. 1-8. DOI: 10.1088/1742-6596/410/1/012053

    Abstract: Modelling on Plasma and gas nitriding of austenitic and low alloy steels have strong influence of interfacial - nanoescale phenomena. Gamma prime and epsilon nitrogen-iron phases evolution during the nitriding process wasn't found explicitly simulated on literature. On present work we simulated nitrind process on low alloy steels - with their precipitation phenomena and nitrides moving interfaces - using diffusional models plus cellular automata. Surface effects and heterogeneities and local transition phenomena considered on our models show that some experimental results considered "errors" on literature are predicted by our simulations. In present work parameters like diffusion coefficient and surface conditions and gradient of nitrogen concentrations between different phases was measured.

    Palavras-Chave: austenitic steels; computerized simulation; concentration ratio; diffusion; interfaces; iron; low alloy steels; nanostructures; nitridation; nitrides; nitrogen; precipitation; surfaces

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  • IPEN-DOC 23873

    IMAM, MUHAMMAD A.; GOMES, M.G.; MOURA, ESPERIDIANA A.B. ; JEELANI, SHAIK; RANGARI, VIJAY K.. Effect of electron-beam irradiation on Nylon-6/diamond coated CNTS composite fiber. In: SAMPE Tech, October 21-24, 2013, Wichita, KS, USA. Proceedings... 2013.

    Abstract: Polyamides (Nylon-6) are engineering plastic with excellent properties which are useful in several industrial applications and are valued for their high strength and processability. The addition of filler such as diamond coated Carbon Nano Tubes (CNTs) to form molded composites has increased the range of polyamide applications due to the resulting increase in strength. The effects of electron-beam irradiation on these thermoplastic nanocomposites are either increases the cross-linking or causes chain scission. In this study, DN-coated CNTs were synthesized using sonochemical technique in the presence of cationic surfactant CTAB. These hybrid nanoparticles were characterized using TEM analysis. The nanoparticles were then introduced into Nylon-6 polymer through a melt extrusion process to form nanocomposite fibers that were tested for their mechanical & thermal properties (e.g. tensile and Differential Scanning Calorimetry). These composites were further exposed to the electron-beam (160 KGy, 132 KGy and 99 KGy) using a 1.5 MeV electron beam accelerator, at room temperature, in presence of air and tested for their thermal and mechanical properties. The ultimate tensile strength were found to be 521 MPa, 690 MPa and 425 MPa for radiated (99 KGy,132 KGy and 160 KGy) DN/CNTs/Nylon-6 single fibers as compared to 346 MPa for DN/CNTs/Nylon-6 single fibers without irradiation and 240 MPa for neat Nylon-6 single fibers respectively. Differential Scanning Calorimetry (DSC) analysis results were showed that degree of cure was increased because of cross-linking which was expected at high electron-beam radiation dose.

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  • IPEN-DOC 23868

    CARDENAS, JOSE P.N. ; MADI FILHO, TUFIC ; PETRI, ANNA R. ; SANTOS, ROBINSON A. dos ; MARTINS, JOAO F.T. ; CARVALHO, DIEGO V.S.; ALVARENGA, T.; BELLEZZO, M.; LARANJO, G.; LIMA, M.; OLIVEIRA, P.; PEREIRA, MARIA da C.C. . Experimental and MCNP studies of paraffin and polyethylene in neutron moderation and BF3 detector efficiency. In: INTERNATIONAL CONFERENCE ON ADVANCEMENTS IN NUCLEAR INSTRUMENTATION, MEASUREMENT METHODS AND THEIR APPLICATIONS, 3rd, June 23-27, 2013, Marseille, France. Proceedings... Piscataway, NJ: IEEE, 2013. DOI: 10.1109/ANIMMA.2013.6727922

    Abstract: The Nuclear and Energy Research Institute – IPEN, offers post-graduate programs, namely: Nuclear Technology - Applications (TNA), Nuclear Technology - Materials (TNM), Nuclear Technology - Reactors (TNR). The Institute programs mission is to form expert technicians and engineers with a strong knowledge in their discipline to work in the nuclear area. The course: “Theoretical Fundaments and Practices of the Instrumentation used in Nuclear Data Acquisition” covers the use of laboratory nuclear instrumentation and the accomplishment of experiments to obtain nuclear parameters. One of these experiments is object of this work: “Experimental and MCNP Studies of Paraffin and Polyethylene Neutron Moderation and BF3 Detector Efficiency”. Neutrons are uncharged particles and, therefore, cannot be detected by Coulomb interactions. Thus, the detector assembly used must contain some kind of material with high cross section for interaction with neutrons, called converters. A boron trifluoride (BF3) detector was used in this experiment to detect neutron in real time. However, the response of this arrangement varies according to the energy range of incident neutrons. Their efficiency for thermal neutrons is above 90%, but, this result decreases, significantly, for neutrons of energy greater than 0.5 eV. The neutron moderation and, consequently, its energy variation were obtained by interposing different thicknesses of moderator material (Paraffin or Polyethylene) between the source and the detector.

    Palavras-Chave: accidents; boron fluorides; computerized simulation; cross sections; data acquisition; efficiency; moderators; monte carlo method; paraffin; polyethylenes; radiation transport; thermal neutrons; thickness

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  • IPEN-DOC 23876

    MATTOS, LUIS A.T. de ; MADI FILHO, TUFIC ; MELDONIAN, NELSON L. . Methodological proposal for identification and evaluation of environmental aspects and impacts of IPEN nuclear facilities: a case study applied to the nuclear fuel center. In: INTERNATIONAL CONFERENCE ON ADVANCEMENTS IN NUCLEAR INSTRUMENTATION, MEASUREMENT METHODS AND THEIR APPLICATIONS, 3rd, June 23-27, 2013, Marseille, France. Proceedings... Piscataway, NJ: IEEE, 2013.

    Abstract: This work presents an application of Failure Mode Effect Analysis (FMEA) to the process of identification of environmental aspects and impacts as a part of implementation and maintenance of an Environmental Management System (EMS) in accordance with the ISO 14001 standard. Also, it can contribute, as a complement, to the evaluation and improvement of safety of the installation focused. The study was applied to the Nuclear Fuel Center (CCN) of Nuclear and Energy Research Institute (IPEN) , situated at the Campus of University of Sao Paulo, Brazil. The CCN facility has the objective of promoting scientific research and of producing nuclear fuel elements for the IEA-R1 Research Reactor. To identify the environmental aspects of the facility activities, products, and services, a systematic data collection was carried out by means of personal interviews, documents, reports and operation data records consulting. Furthermore, the processes and their interactions, failure modes, besides their causes and effects to the environment, were identified. As a result of a careful evaluation of these causes it was possible to identify and to classify the major potential environmental impacts, in order to set up and put in practice an Environmental Control Plan for the installation under study. The results have demonstrated the validity of the FMEA application to nuclear facility processes, identifying environmental aspects and impacts, whose controls are critical to achieve compliance with the environmental requirements of the Integrated Management System of IPEN. It was demonstrated that the methodology used in this work is a powerful management tool for resolving issues related to the conformity with applicable regulatory and legal requirements of the Brazilian Nuclear Energy Commission (CNEN) and the Brazilian Institute of Environment (IBAMA).

    Palavras-Chave: environmental impacts; fabrication; failures; fuel cycle centers; fuel elements; implementation; maintenance; nuclear fuels; operation

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  • IPEN-DOC 23875

    MADI FILHO, TUFIC ; CARDENAS, JOSE P.N. ; PETRI, ANNA R. ; SANTOS, ROBINSON A. dos ; MARTINS, JOAO F.T. ; CARVALHO, DIEGO V.S.; ALVARENGA, T.; BELLEZZO, M.; LARANJO, G.; LIMA, M.; OLIVEIRA, P.; PEREIRA, MARIA da C.C. . Am-Be neutron irradiator used for nuclear instrumentation training. In: INTERNATIONAL CONFERENCE ON ADVANCEMENTS IN NUCLEAR INSTRUMENTATION, MEASUREMENT METHODS AND THEIR APPLICATIONS, 3rd, June 23-27, 2013, Marseille, France. Proceedings... Piscataway, NJ: IEEE, 2013.

    Abstract: A neutron irradiator was assembled at IPEN (Nuclear and Energy Research Institute) facility to perform qualitative-quantitative analysis of materials, using thermal and fast neutrons. In order to determine the 116mIn decay constant, a thermal flux obtained experimentally by Monte Carlo N-Particle Transport Code-MCNP, in a previous work, was used in the nuclear experiment. The activity calculated from the activation parameters was 13.51±0.17 kBq and the activity determined experimentally was 12.51± 0.36 kBq. The decay constant determined by the pulse height analyzer (PHA) measures was 211.4 μ·s-1, and that determined by fitting the data using a Multichannel Scaler (MCS) system was 200.3 ± 1.6 μ·s-1. The half-life of 116mIn found in the literature is 3256.8 s, which corresponds to a decay constant of 212.8 μ·s-1. The present experiment does not intend to establish a new value for the decay constant: it solely aims students’ practical exercises in nuclear properties of elements. This experiment is part of the nuclear experimental course.

    Palavras-Chave: half-life; indium 116; neutrons; nuclear decay; nuclear properties

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  • IPEN-DOC 23867

    CARDENAS, JOSE P.N. ; MADI FILHO, TUFIC ; RICCI FILHO, WALTER ; CARVALHO, MARCOS R. de ; BENEVENUTI, ERION de L. ; GOMES NETO, JOSE . Digital systems implemented at the IPEN nuclear research reactor (IEA-R1): results and necessities. In: INTERNATIONAL CONFERENCE ON ADVANCEMENTS IN NUCLEAR INSTRUMENTATION, MEASUREMENT METHODS AND THEIR APPLICATIONS, 3rd, June 23-27, 2013, Marseille, France. Proceedings... Piscataway, NJ: IEEE, 2013.

    Abstract: IPEN (Nuclear and Energy Research Institute) was founded in 1956 with the main purpose of doing research and development in the field of nuclear energy and its applications. It is located at the campus of University of Sao Paulo (USP), in the city of Sao Paulo, in an area of nearly 500,000 m2. It has over 1.000 employees and 40% of them have qualification at master or doctor level The institute is recognized as a national leader institution in research and development (R&D) in the areas of radiopharmaceuticals, industrial applications of radiation, basic nuclear research, nuclear reactor operation and nuclear applications, materials science and technology, laser technology and applications. Along with the R&D, it has a strong educational activity, having a graduate program in Nuclear Technology, in association with the University of Sao Paulo, ranked as the best university in the country. The Federal Government Evaluation institution CAPES, granted to this course grade 6, considering it a program of Excellence. This program started at 1976 and has awarded 458 Ph.D. degrees and 937 master degrees since them. The actual graduate enrollment is around 400 students. One of major nuclear installation at IPEN is the IEA-R1 research reactor; it is the only Brazilian research reactor with substantial power level suitable for its utilization in researches concerning physics, chemistry, biology and engineering as well as for producing some useful radioisotopes for medical and other applications. IEA-R1 reactor is a swimming pool type reactor moderated and cooled by light water and uses graphite and beryllium as reflectors. The first criticality was achieved on September 16, 1957. The reactor is currently operating at 4.5 MW power level with an operational schedule of continuous 64 hours a week. In 1996 a Modernization Program was started to establish recommendations in order to mitigate equipment and structures ageing effects in the reactor components, detect and evaluate obsolescence of some electrical and electronic systems. In this work we will show a retrospective and results of digital systems applied to IEA-R1 reactor concerning electronic equipments and systems refurbishment and modernization and the necessity of a new control console implementation.

    Palavras-Chave: data acquisition; digital systems; electronic equipment; iear-1 reactor; nuclear facilities; radioisotopes; radiopharmaceuticals; reactor components

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  • IPEN-DOC 23866

    BORGES, R.; SILVA, A.C. da ; MARCHI, J.. Caracterização de biovidros bioabsorvíveis para aplicação em medicina regenerativa. In: CONGRESSO BRASILEIRO DE CERAMICA, 57.; CONGRESSO IBEROAMERICANO DE CERAMICA, 5., 19-22 de maio, 2013, Natal, RN. Anais... São Paulo: ABCERAM, 2013.

    Abstract: Neste trabalho, foram estudadas três composições de vidros bioaborvíveis com potencial aplicação em medicina regenerativa. Vidros no sistema SiO2 - (37- x)Na2O- (5+x)CaO com 6% de P2O5 (x = 0, 5 e 10) foram obtidos por fusão seguida de superresfriamento e posterior recozimento. Sua biocompatibilidade foi avaliada por imersão em solução SBF e caracterização da superfície dos vidros após diferentes períodos de imersão. Os vidros foram caracterizados antes e após o ensaio de bioatividade pelas técnicas de difração de raio-x, espectroscopia de infravermelho na transformada de Fourier e microscopia eletrônica de varredura e por estudo de variação de massa. Os resultados obtidos indicam que nestes vidros bioabsorvíveis o mecanismo de bioatividade ocorre, primeiramente, através da formação de uma camada de silicato de cálcio que atua como nucleador de deposição de posterior segunda camada de hidroxiapatita. Também foi verificado que a cinética de nucleação de hidroxiapatita pode ser controlada através da razão Ca/Na.

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  • IPEN-DOC 23895

    CHOQUECHAMBI CATORCENO, LITZY L.; LIMA, NELSON B. de . Influence of rolling direction and temperature on the texture formation in rolled AZ31B magnesium alloy. In: ALDERMAN, MARTYN (Ed.); MANUEL, MICHELE V. (Ed.); HORT, NORBERT (Ed.); NEELAMEGGHAM, NEALE R. (Ed.) MAGNESIUM TECHNOLOGY; TMS ANNUAL MEETING & EXIBITION, February 16-20, 2014, San Diego, CA, USA. Proceedings... Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. p. 245-250. DOI: 10.1002/9781118888179.ch47

    Abstract: In this study, effects of rolling direction and temperature on the texture formation were investigated for the purpose of enhancing formability of rolled AZ31B alloy. For this, specimens were cold and warm rolled from a rolled sheet, both parallel and perpendicular to the rolling direction and textures of the sheets processed were examined. The results showed that samples rolled parallel to the rolling direction generated strong basal texture during cold and warm rolling process. However, on sample rolled perpendicular to the rolling direction at 300°C resulted in the formation of basal textures with low intensities. The (0002) pole was inclined towards the transverse direction. The occurrence of recrystallization at high temperatures contributed to the formation of low intensities basal textures.

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  • IPEN-DOC 23863

    SARTORI, MARIANA N. ; OLIVEIRA, RENE R. ; DIAZ, FRANCISCO R.V.; ORTIZ, ANGEL V. ; RANGARI, VIJAYA K.; MOURA, ESPERIDIANA A.B. . Preparation and characterization of PBT/clay nanocomposite. In: WANG, SHIJIE (Ed.); DULRIZAC, JOHN E. (Ed.); FREE, MICHAEL L. (Ed.); HWANG, JAMES Y. (Ed.); KIM, DANIEL (Ed.) T.T. CHEN HONORARY SYMPOSIUM ON HYDROMETALLURGY, ELECTROMETALLURGY AND MATERIALS CHARACTERIZATION; TMS ANNUAL MEETING & EXIBITION, March 11-15, 2012, Orlando, Florida, USA. Proceedings... Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. p. 731-739. DOI: 10.1002/9781118364833.ch68

    Abstract: This work presents the preparation and characterization of a nanocomposite based on Poly(butylene terephthalate) PBT and Brazilian smectitic clay (bentonite chocolate clay). Before being incorporated as clay nanoparticles in PBT resin, the clay was organically modified by the addition of a quaternary salt and sodium carbonate. PBT/Clay nanocomposite (96.3:3.70 wt %) was obtained by using a twin-screw extruder machine. After extrusion process, the nanocomposite was characterized by tensile, flexural and impact tests, SEM, Vicat, HDT, DSC, TGA and XRD tests. The results showed that the properties of the nanocomposite obtained were superior to those of neat PBT. Concerning the temperature of thermal distortion (HDT) an expressive gain of around 45 % was presented to PBT/Clay nanocomposite compared to PBT evidencing the interaction of nanofiller with the polymeric matrix.

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  • IPEN-DOC 23881

    ORTIZ, ANGEL ; ESCANHOELA, CORDELIA M.F. ; GOMES, MICHELLE ; OLIVEIRA, RENE R. ; DIAZ, FRANCISCO R.V.; MOURA, ESPERIDIANA A.B. . Comparison between HDPE/clay and HDPE/piassava fiber/clay treated by electron beam radiation. In: HWANG, JIANN-YANG (Ed.); BAI, CHENGGUANG (Ed.); CARPENTER, JOHN (Ed.); IKHMAYIES, SHADIA J. (Ed.); LI, BOWEN (Ed.); MONTEIRO, SERGIO N. (Ed.); PENG, ZHIWEI (Ed.); ZHANG, MINGMING (Ed.) CHARACTERIZATION OF MINERALS, METALS, AND MATERIALS. 142th; ANNUAL MEETING & EXIBITION, March 3-7, 2013, San Antonio, Texas, USA. Proceedings... Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. p. 425-432. DOI: 10.1002/9781118659045.ch49

    Abstract: This work evaluates changes in morphological, mechanical and thermo-mechanical properties of electron-beam irradiated HDPE/nanoclay and HDPE/Piassava fiber/nanoclay. Material samples irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator (room temperature, presence of air) were submitted to tensile, flexural, and HDT tests. MFI, SEM and XRD analyses were carried out. Correlation between properties was discussed. Results showed that incorporation of piassava (Attalea funifera Mart) fiber and nanoclay, followed by irradiation represented significant gain in thermo-mechanical properties. Changes in surface morphology and reduction in MFI were observed. In conclusion, it may be claimed that the incorporation of piassava fiber in small size particles and nanoclay in the HDPE followed by electron-beam irradiation effectively improved the polymer properties and led to materials with superior properties suitable for several industrial applications.

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  • IPEN-DOC 23861

    PEREIRA, AMANDA C.S. ; CHINELLATO, ANNE C.; SORIA, ALEJANDRA T.; ABREU, ANIBAL V.; DEL MASTRO, NELIDA L. ; MOURA, ESPERIDIANA A.B. . Comparative study of the sugarcane bagasse FIBER/HDPE composite properties using electron-beam and gamma radiation treatments. In: HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGGUANG (Ed.); CARPENTER, JOHN (Ed.); CAI, MINGDONG (Ed.); FIRRAO, DONATO (Ed.); KIM, BUOUNG-GON (Ed.) CHARACTERIZATION OF MINERALS, METALS, AND MATERIALS. 141th; ANNUAL MEETING & EXIBITION, March 11-15, 2012, Orlando, Florida, USA. Proceedings... Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. p. 403-410. DOI: 10.1002/9781118371305.ch48

    Abstract: This work presents a comparative study of the thermo-mechanical and morphological properties of sugarcane bagasse fiber/HDPE composite treated with electron-beam and gamma radiation. The composite samples obtained by extrusion and injection molding processes were irradiated at 50 and 90 kGy using either a 1.5 MeV electron beam accelerator or gamma irradiator EMI-9, at room temperature in presence of air. The irradiated and non-irradiated samples were submitted to mechanical and MFI tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), sol-gel analysis and X-Rays Diffraction (XRD) and the correlation between their properties was discussed. Improvement of the bagasse fiber/HDPE composite properties, using electron-beam or gamma radiation, was found.

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  • IPEN-DOC 23860

    NOGUEIRA, BEATRIZ R. ; CHINELLATO, ANNE; ORTIZ, ANGEL V. ; PARVEEN, ARIFA; RANGARI, VIJAYA K.; MOURA, ESPERIDIANA A.B. . Thermal and morphological behavior of EVOH/piassava fiber composites. In: HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGGUANG (Ed.); CARPENTER, JOHN (Ed.); CAI, MINGDONG (Ed.); FIRRAO, DONATO (Ed.); KIM, BUOUNG-GON (Ed.) CHARACTERIZATION OF MINERALS, METALS, AND MATERIALS. 141th; ANNUAL MEETING & EXIBITION, March 11-15, 2012, Orlando, Florida, USA. Proceedings... Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. p. 373-380. DOI: 10.1002/9781118371305.ch44

    Abstract: Composite consisting of ethylene vinyl alcohol (EVOH) with short piassava fibers were prepared by extrusion process and their thermal and morphological behavior were investigated. The EVOH reinforced with 5 and 10 % of piassava {Attaleafimifera Mart) fiber particle, based on the percentage weight ratio (wt %), untreated and treated with a commercial silane coupling agent, were prepared and the influence of fiber loading and the effect of chemical treatment on their thermal and morphological behavior were evaluated by SEM, DSC and TG analyses. Melt flow index (MFI) of the composites have been determined to evaluate the effects of fiber reinforcement on dynamic viscoelastic melt of the EVOH. In addition, piassava fibers characterization by SEM, FTIR, and organic and inorganic composition have also been carried out. The SEM results of the composites showed surface micrographs without microvoids and a good distribution, dispersion and compatibility between the fillers and the EVOH matrix. Concerning the piassava fibers characterization, the results showed that piassava has higher lignin content than cellulose and hemicelluloses, and around 0.7 % of ash with 52 % of silica (Si02). This high concentration of silica is consistent with the SEM analysis of the fiber that showed a large amount of "silica rings" encrusted on their surface.

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  • IPEN-DOC 23877

    MELO JUNIOR, A.S.; GATTI, L. ; SEVEGNANI, F.; SATIE, I.; IZIDRO, J.; IANNUZZI, A.. Estudo da emissão veicular de gases de efeito estufa (GEE) em veículos movidos à gasolina. In: INTERNATIONAL WORKSHOP: ADVANCES IN CLEANER PRODUCTION, 4th, May 22-24, 2013, São Paulo, SP. Anais... 2013. p. 1-5.

    Abstract: Saber o comportamento da emissão de gases de efeito estufa (GEE) na atmosfera é importante devido às mudanças climáticas globais e suas consequências para os ecossistemas. Estudos envolvendo a emissão veicular são de grande importância devido ao seu papel na emissão de GEE. O intuito da pesquisa foi determinar a emissão dos principais GEE (CO2, CH4 e N2O) na frota de veículos movidos à gasolina. Por tal, foram estudados dois veículos movidos à gasolina de anos de fabricação diferentes. Os ensaios foram realizados no dinamômetro da CETESB e no IPEN.

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  • IPEN-DOC 23874

    LAINETTI, P.E.O. . Decomposição térmica segura de pesticidas organoclorados por oxidação submersa em sais fundidos. In: INTERNATIONAL WORKSHOP: ADVANCES IN CLEANER PRODUCTION, 4th, May 22-24, 2013, São Paulo, SP. Anais... 2013. p. 1-10.

    Abstract: Este estudo foi motivado pelo interesse atual, em todo o mundo,no desenvolvimento de processos avançados de decomposição de resíduos, categoria na qual o processo aqui descrito se insere. Este interesse decorre da necessidade de processos mais seguros para a decomposição de determinados resíduos, particularmente aqueles considerados perigosos ou que apresentem impacto significativo no meio ambiente. A tecnologia desenvolvida se enquadra em tal princípio, sendo aplicável para a eliminação intrinsecamente segura deresíduos orgânicos perigosos, particularmente os organoclorados, cuja degradação tem apresentado problemas quando da utilização de métodos mais comuns, como a incineração. Pesticidas banidos, obsoletos ou descartados constituem um sério risco ambiental em todo o mundo, principalmente nos países em desenvolvimento. Os HCHs, ou hexaclorociclohexanos, também denominados BHC ou Lindane, são inseticidas organoclorados banidos na maioria dos países nos anos 70 e 80 . É um dos compostos que constituem o grupo dos chamados POPs, ou seja, poluentes orgânicos persistentes, que são regulados internacionalmente pela Convenção da Basiléia. Dentre os principais POPs poderiam ser citados os pesticidas, as dioxinas e os PCBs que representam, segundo a United Nations Industrial DevelopmentOrganization – UNIDO,um dos problemas mais sérios e urgentes a serem enfrentados, devido, por um lado, à sua ampla difusão no meio ambiente e, por outro, em virtude das suas propriedades e características particulares, as quais determinam sua persistência em águas e solos. A United Nations Environmental Protection - UNEP, por exemplo, iniciou uma ação global para o estabelecimento deum tratado internacional para reduzir e/ou eliminar emissões e descargas de 12 POPs específicos, conhecidos também como “dirtydozen” , ou, literalmente, “dúzia suja” (Aldrin, Clordano, Mirex, Dieldrin, DDT, dioxinas, furanos, PCBs, Endrin, heptacloro, BHC e toxafeno), além de estabelecer critérios científicos para a possível inclusão de outros. A oxidação em sais fundidos é um processo que promove uma decomposição mais completa e mais segura de resíduos considerados críticos, como por exemplo, os POPs (poluentes orgânicos persistentes), produtos químicos obsoletos, compostos extremamente energéticos (propelentes e explosivos), etc. Neste processo, o resíduo e o oxidante (ar ou ar enriquecido com oxigênio) são misturados abaixo da superfície de um leito turbulento de sais em fusão. A oxidação ocorre em temperaturas de processo mais baixas que as da incineração convencional, mas que associadas à fase líquida em que ocorrem as reações, são suficientes para promover uma decomposição completa e segura de resíduos perigosos, particularmente os organoclorados. Neste caso, o cloro reage com o sódio, formando cloreto de sódio, que fica retido no banho salino. Neste trabalho, descrevem-se as atividades de construção e desenvolvimento de um reator de sais fundidos, para decomposição de resíduos perigosos, bem como são apresentados alguns resultados da decomposição de pesticidas.

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  • IPEN-DOC 23865

    BERTOLINI, T.C.R. ; MAGDALENA, C.P. ; IZIDORO, J.C. ; CUNICO, P. ; FUNGARO, D.A. . Adsorção de ácido laranja 8 de solução aquosa sobre zeólitas sintetizadas a partir de cinzas leves de carvão modificadas por surfactante. In: INTERNATIONAL WORKSHOP: ADVANCES IN CLEANER PRODUCTION, 4th, May 22-24, 2013, São Paulo, SP. Anais... 2013. p. 1-10.

    Abstract: A adsorção do corante ácido laranja 8 (AL8) sobre zeólitas de cinzas leves de carvão modificadas por surfactante foi avaliada. As cinzas de carvão utilizadas na síntese da zeólita (ZCC) por tratamento hidrotérmico alcalino foram coletadas nas Usinas Termelétricas Jorge Lacerda (SC) e Figueira (PR). A modificação das zeólitas foi realizada pela mistura de ZCC com o surfactante brometo de hexadeciltrimetilamônio e os materiais obtidos foram zeólita modificada de Jorge Lacerda (ZMJ) e zeólita modificada de Figueira (ZMF). O equilíbrio de adsorção do corante foi atingido após 90 min para a ZMJ e a ZMF. Os dados experimentais ajustaram-se melhor ao modelo cinético de pseudo-segunda-ordem para ambos adsorventes. O equilíbrio de adsorção foi descrito em termos das isotermas de Langmuir e Freundlich e o modelo de Freundlich foi o mais compatível com os dados experimentais para ZMJ e ZMF. As capacidades de adsorção máximas foram 5,29 mg g-1 para o sistema AL8/ZMJ e 1,79 mg g-1 para o sistema AL8/ZMF.

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  • IPEN-DOC 23856

    BONIFACIO, DANIEL A.B.; MORALLES, MAURICIO . Modeling of 3D gamma interaction position in a monolithic scintillator block with a row-column summing readout. In: IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE RECORD, October 29 - November 3, 2012, Anaheim, CA, USA. Proceedings... Piscataway, NJ: IEEE, 2012. p. 2606-2613. DOI: 10.1109/nssmic.2012.6551596

    Abstract: Current positron emission tomography (PE T ) systems have their detector design based on discrete scintillation crystals. Spatial resolution of these systems are directly related with the size of the crystal segments. On the other hand, cost and complexity increase considerably as the size of the crystal segments decreases. Detector design with continuous scintillator is another approach that improves the energy resolution and sensitivity without degrading the spatial resolution. In this work, we report a method to determine the gamma interaction position with depth of interaction (DOl) capability inside a monolithic crystal coupled to a photodetector array. T he method is based on estimating parameters of a model which describes the signal distribution of the optical photons collected by the photodetector array in a row-column summing readout scheme. Evaluation data were simulated using the GATE framework (Geant4 Application for Emission Tomography) to characterize the detector and to compare the interaction position of the incident gamma with the position registered by the detector.

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  • IPEN-DOC 23857

    CARATIN, R.L. ; MARINUCCI, G. . Analysis of fiber-concrete interface in cement matrix composites. In: EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, 15th, June 24-28, 2012, Venice, Italy. Proceedings... 2012. p. 1-5.

    Abstract: In the present work, the properties of fiber-cement interface were evaluated in order to enable the use of continuous glassfiber-AR (alkali resistant), replacing steel bars often used in concrete structures by civil construction industry. Pull-out tests were applied in a continuous glassfiber-AR (alkali resistant) reinforcement element. The fiber was 250 mm length and it was inserted 50 mm in a cement matrix specimen whose dimensions are 100 x 100 x 100 mm. The bond strength values were compared to concrete specimen that was manufactured corrugated steel bars. Preliminary results identified an increase of 41% in the fiber-cement bond strength value by using glassfiber – AR when compared to steel bar and cement matrix composites.

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  • IPEN-DOC 23855

    BONALUME, B.C.F.; LEBRAO, G.W.; ROSSI, J.L. . Microwave assist functionalization of multi walled carbon nanotubes. In: EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, 15th, June 24-28, 2012, Venice, Italy. Proceedings... 2012. p. 1-8.

    Abstract: There are many technique to increase reactivity of carbon nanotubes, this article study a improvement in oxidation and silanization procedures. Two oxidation methods are frequently used in carbon nanotubes: the conventional acid treatment, and the microwave treatment. The nanotubes oxidation was studied using microwaves and varying power and time of exposure. Compared to conventional acid treatment, the use of microwave provides benefits in speeding the reaction time, lowest amount of acids required and agitation is not needed. The present procedure was successful in the functionalization of carbon nanotubes with 3- aminopropyltriethoxysilane, which is a coupling agents that have a unique feature, bound organic to inorganic molecules.

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  • IPEN-DOC 23897

    LEPINE-SZILY, A.; LEISTENSCHNEIDER, E.; MENDES JUNIOR, D.R.; DESCOUVEMONT, P.; LICHTENTHALER, R.; GUIMARAES, V.; FARIA, P.N. de; BARIONI, A.; PIRES, K.C.C.; MORCELLE, V.; PAMPA CONDORI, R.; MORAES, M.C.; SCARDUELLI, V.; ROSSI, E.; ZAGATTO, V.A.; SANTOS, H.; AGUIAR, V.A.P.; BRITOS, T.; ASSUNÇAO, M.; ZAMORA, J.C.; DUARTE, J.; SHORTO, J.M.B. . Spectroscopy of high lying resonances in 9Be produced with radioactive 8Li beams. In: INTERNATIONAL WORKSHOP ON COMPOUND NUCLEAR REACTIONS AND RELATED TOPICS, 4th, October 07-11, 2013, São Paulo, SP. Proceedings... Les Ulis, France: EDP Sciences, 2014. p. 1-7. (EPJ Web of Conferences, 69, UNSP 00006). DOI: 10.1051/epjconf/20136900006

    Abstract: We present the results of the 8Li(p,α)5He and 8Li(p,p)8Li reactions measured at the RIBRAS (Radioactive Ion Beams in Brazil) system. The experiment was realized in inverse kinematics using a thick [CH2]n polyethylene target and an incident 8Li beam, produced by RIBRAS. Using the thick target method, the complete excitation function could be measured between Ecm = 0.2 − 2.1 MeV, which includes the Gamow peak energy region. The excitation function of the 8Li(p,α)5He reaction, populating resonances between 16.888 and 19.0 MeV in 9Be, was obtained[1] and the resonances were fitted using R-matrix calculations. This study shed light on spins, parities, partial widths and isospin values of high lying resonances in 9Be. The measurement of the resonant elastic scattering 8Li(p,p)8Li populating resonances in the same energy region can constrain the resonance parameters. Preliminary results of the elastic scattering are also presented.

    Palavras-Chave: beryllium 9; cross sections; elastic scattering; excitation functions; lithium 8; nucleosynthesis; polyethylenes; radioactive ion beams; resonance; solenoids; spectroscopy; targets

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  • IPEN-DOC 23880

    NISTI, M.B. ; SAUEIA, C.H.R. ; MAZZILLI, B.P. ; MENESES, N.F.A.. Assessment of metals by instrumental neutron activation analysis in six fish species consumed in the city of São Paulo. In: INTERNATIONAL CONFERENCE ON HEAVY METALS IN THE ENVIRONMENT, 16th, September 23-27, 2012, Rome, Italy. Proceedings... Les Ulis, France: EDP Sciences, 2013. p. 1-3. (EPJ Web of Conferences, 1, 37007). DOI: 10.1051/e3sconf/20130176007

    Abstract: The objective of this work is to quantify the concentration of the metals As, Co, Cs, Fe, K, Na, Rb, Sb, Sc, Sm, Th, U and Zn in the muscles of six fish species (anchovy, brycon, catfish, hake, pacu and sardine). Metals characterization was performed by instrumental neutron activation analysis (INAA). The elements determination was made by irradiation of approximately 150 mg of each sample (dry weight), during 16 hours at a neutron flux of 1012 n.cm-2.s-1 in the nuclear research reactor IEA-R1 of Instituto de Pesquisas Energéticas e Nucleares (IPEN). Most of the results for the metals concentration is low, exception for As and Zn in seawater fish and for Rb in river fish. The results obtained in this study can be used to ensure the quality of the fish consumed in the city of São Paulo.

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  • IPEN-DOC 23854

    ANDRADE-II, E.; MENEZES, J.C.M.; DUARTE, S.B.; GARCIA, F.; ROSSI, P.C.R. ; TAVARES, O.A.P.; DEPPMAN, A.. Effects of fissioning nuclei distributions on fragment mass distributions for high energy fission. In: INTERNATIONAL WORKSHOP ON COMPOUND NUCLEAR REACTIONS AND RELATED TOPICS, 3rd, September 19-23, 2011, Prague, Czech Republic. Proceedings... Les Ulis, France: EDP Sciences, 2012. p. 1-9. (EPJ Web of Conferences, 21, 10001). DOI: 10.1051/epjconf/20122110001

    Abstract: We study the effects of fissioning nuclei mass- and energy-distributions on the formation of fragments for fission induced by high energy probes. A Monte Carlo code called CRISP was used for obtaining mass distributions and spectra of the fissioning nuclei for reactions induced by 660 MeV protons on 241Am and on 239Np, by 500 MeV protons on 208Pb, and by Bremsstrahlung photons with end-point energies at 50 MeV and 3500 MeV on 238U. The results show that even at high excitation energies, asymmetric fission may still contribute significantly to the fission cross section of actinide nuclei, while it is the dominante mode in the case of lead. However, more precise data for high energy fission on actinide are necessary in order to allow definite conclusions.

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  • IPEN-DOC 23845

    MOREIRA, TATIANA M. ; SEO, EMILIA S.M. . Reúso da água de chuva: uma alternativa sustentável para os períodos de escassez hídrica / Reuse of rain water: a sustainable alternative for the periods water shortage. In: SIMPÓSIO INTERDISCIPLINAR DE CIÊNCIA AMBIENTAL, 2., 14-16 de setembro, 2016, São Paulo, SP. Anais... São Paulo: IEE/USP, 2016. p. 547-558.

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  • IPEN-DOC 23844

    MOREIRA, E.G. ; VASCONCELLOS, M.B.A. ; ROSA, M.M.L.; TADDEI, M.H.T.. Naturally occurring radionuclides in a Brazilian mussel reference material. In: NATURALLY OCCURRING RADIOACTIVE MATERIAL, 8th, October 18-21, 2016, Rio de Janeiro, RJ. Proceedings... 2016.

    Abstract: Certified reference materials are important tools for the quality assurance of analytical results. However there are several constraints for their widespread use in developing countries such as technological development or difficult access to imported goods. Another issue is that analyte level differences between imported certified reference materials and local laboratory samples may be a concern in the measurement process. This contribution describes the naturally occurring activity concentrations of 234U, 235U, 238U and 232Th, determined by Alpha Spectrometry after a radiochemical separation procedure and 40K and 210Pb determined by Gamma Ray Spectrometry in a Perna perna mussel reference material produced in Brazil. Obtained activity concentrations were included as information values in the certification process of the reference material.

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  • IPEN-DOC 23836

    CARVALHO, PRISCILLA R. ; MUNITA, CASIMIRO S. . Avaliação de análise de agrupamentos pelo coeficiente de correlação cofenética: estudo preliminar. In: CONGRESSO LATINO-AMERICANO DE ARQUEOMETRIA, 5., 7-11 de novembro, 2016, São Paulo, SP. Anais... 2016. p. 1-10.

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  • IPEN-DOC 23835

    BRESSANE, R.O. ; VILLANI, D. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Estudo comparativo de sensibilidade entre os dosímetros fricke xilenol gel e alanina gel / Comparative study of sensitivity between Fricke Xylenol Gel and Alanine Gel. In: CONGRESSO DE PROTEÇÃO CONTRA RADIAÇÕES DA COMUNIDADE DOS PAÍSES DE LÍNGUA PORTUGUESA, 5., 10-12 de março, 2016, Coimbra, Portugal. Anais... Coimbra: Sociedade Portuguesa de Proteção Contra Radiações, 2016.

    Abstract: Fricke Xilenol Gel (FXG) é um dosímetro químico bem conhecido e caracterizado. Neste trabalho, foi adicionada alanina ao FXG a fim de obter melhora na sensibilidade. A comparação entre os dois dosímetros permitiu verificar maior estabilidade no gel devido à presença da alanina e aumento do intervalo de linearidade da resposta óptica: de 1 a 30 Gy para 5 a 50 Gy. Foi possível verificar, também, que a variação de cor das amostras após a irradiação é característica de cada tipo de dosímetro e que a sensibilidade do dosímetro com alanina é maior utilizando-se 0,2 mM de alaranjado de xilenol.

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  • IPEN-DOC 23832

    ALMEIDA, H.C.; NASCIMENTO, T.B.S.; TADDEI, M.H.T.; MAZZILLI, B.P. . A comparison between 210Pb and 210Po activity concentration on Sediment Dating. In: INTERNATIONAL SYMPOSIUM ON NATURALLY OCCURING RADIOACTIVE MATERIAL,8th, October 18-21, 2016, Rio de Janeiro, RJ. Proceedings... 2016.

    Abstract: Records stored in natural archives, such as lake sediments, are used in environmental programs for the assessment of changing erosion rates in a catchment arising from disturbances, and to monitor pollution by heavy metals and other contaminants. Accurate sediment chronologies are important to interpret those practices. One of the most important means to date recent sediments is through 210Pb. This radionuclide occurs naturally as one of the 238U decay series. It is widely distributed on the earth due to its formation from radium in the ground or from radon that emanates to the atmosphere or decays to 210Pb. The 210Pb is deposited as particulates and falls into lakes where it is scavenged from the water column and deposited on the basins. Excess of 210Pb is measured through gamma spectrometry technique. However, this technique has a low sensibility and small values are difficult to detect or need to be analyzed for a long time. 210Po is a decay product of 210Pb and its determination through alpha spectrometry is more sensitive and faster. The aim of this paper is to compare both radionuclides activity concentration in lakes sediments cores to evaluate the use of 210Po in dating of locals with low levels of 210Pb.

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  • IPEN-DOC 23818

    VEDOVATO, U.P.; SILVA, R.J.V.; NEVES, L.P. ; SANTOS, W.S. ; BELINATO, W.; CALDAS, L.V.E. ; PERINI, A.P.. Utilização da simulação de Monte Carlo para o estudo de uma câmara de ionização de extrapolação em um feixe de radiodiagnóstico padrão. In: SIMPÓSIO DE ENGENHARIA BIOMÉDICA, 9., 22-26 de agosto, 2016, Uberlândia, MG. Anais... 2016. p. 4-6.

    Abstract: Neste trabalho, foi estudada a influência dos componentes de uma câmara de ionização de extrapolação na sua resposta. Este estudo foi realizado utilizando o código de Monte Carlo MCNP-4C, e a qualidade padrão de radiodiagnóstico para feixes diretos (RQR8). Usando o tally F6 e 2,1 𝑥𝑥 109 histórias simuladas, os resultados mostraram que a configuração e o material da câmara de ionização não alteraram significativamente a energia depositada em seu volume sensível. O eletrodo coletor e a placa suporte foram os componentes com maior influência na resposta da câmara de ionização.

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  • IPEN-DOC 23802

    MENDONÇA, D.S.C.; NEVES, L.P. ; SANTOS, W.S. ; BELINATO, W.; CALDAS, L.V.E. ; PERINI, A.P.. Aplicação do método de monte carlo para avaliação de uma câmara de ionização tipo lápis especial. In: SIMPÓSIO DE ENGENHARIA BIOMÉDICA, 9., 22-26 de agosto, 2016, Uberlândia, MG. Anais... 2016. p. 10-12.

    Abstract: Uma câmara de ionização tipo lápis especial, foi avaliada para determinar a influência de seus componentes em sua resposta, para feixes padrões diretos de raios X. Para este propósito, empregou-se o método de Monte Carlo e um espectro padrão de radiodiagnóstico (RQR5). Os resultados obtidos mostram que, embora, esta câmara de ionização tipo lápis tenha sido fabricada para dosimetria de tomografia computadorizada, ela também pode ser empregada para dosimetria de feixes padrões de radiodiagnóstico. Isto se deve ao fato de que não houve influência significativa dos componentes da câmara de ionização na sua resposta, quando esta foi irradiada com feixes de radiodiagnóstico.

    Palavras-Chave: ionization chambers; monte carlo method; radiology; beams; standards

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  • IPEN-DOC 23793

    FERREIRA, P.Z.; CARVALHO, G.S.M.; CUNHA, D.M.; DANTAS, N.O.; SILVA, A.C.A.; NEVES, L.P. ; CALDAS, L.V.E. ; CARRERA, B.N.S.; WATANABE, S.; PERINI, A.P.. Utilização da técnica de termoluminescência para caracterização de uma nova matriz vítrea. In: SIMPÓSIO DE ENGENHARIA BIOMÉDICA, 9., 22-26 de agosto, 2016, Uberlândia, MG. Anais... 2016. p. 13-16.

    Abstract: A utilização de dosímetros é muito importante na monitoração de radiação ionizante, que pode ser empregada na área médica, industrial e ambiental. A técnica de termoluminescência é muito utilizada em dosimetria de doses altas, que inclui atividades como gamagrafia, esterilização de materiais cirúrgicos, irradiação de alimentos, etc. As principais vantagens de materiais dosimétricos termoluminescentes são as suas pequenas dimensões, o fato de não necessitarem de cabos ou equipamentos auxiliares durante a medida da dose e suas altas sensibilidades para detecção de radiação. A técnica termoluminescente consiste basicamente na detecção de um sinal luminescente, de um material previamente irradiado, por meio de um estímulo térmico. Neste trabalho, a técnica de termoluminescência foi utilizada para estudar uma nova matriz vítrea, com composição nominal de 20Li2CO3.10Al2O3.10BaO.60B2O3 (mol%) irradiada com doses entre 10 Gy e 900 Gy em uma fonte de 60Co. Os resultados obtidos mostraram que esta nova matriz vítrea apresenta uso potencial em dosimetria de altas doses.

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  • IPEN-DOC 23785

    CARVALHO, G.S.M.; FERREIRA, P.Z.; CUNHA, D.M.; DANTAS, N.O.; SILVA, A.C.A.; PERINI, A.P.; CALDAS, L.V.E. ; CARRERA, B.N.S.; WATANABE, S.; NEVES, L.P. . Avaliação de novas matrizes vítreas pela técnica de termoluminescência para dosimetria de doses altas. In: SIMPÓSIO DE ENGENHARIA BIOMÉDICA, 9., 22-26 de agosto, 2016, Uberlândia, MG. Anais... 2016. p. 7-9.

    Abstract: Novas matrizes vítreas foram avaliadas para dosimetria de doses altas. Suas composições nominais são 20Li2CO3.10Al2O3.10CdO.60B2O3 e 20Li2CO3.10Al2O3.15CdO.55B2O3 (mol%). As matrizes vítreas foram irradiadas com diferentes doses: 50, 100, 200, 500, 700 e 900 Gy, e foram analizadas pela técnica de termoluminescência. As curvas de emissão termoluminescente foram obtidas e mostram um grande potencial de uso dessas matrizes para dosimetria de doses altas.

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  • IPEN-DOC 23790

    COUTO, C.P.; COSTA, P.D.O.L.; MARTINEZ, L.G. ; TURRILLAS, X. ; ROSSI, J.L. . The use of X-ray diffraction for phase identification of press hardened steels. In: WORKSHOP OF APPLIED CRYSTALLOGRAPHY TO MATERIALS SCIENCE AND ENGINEERING, 6th, 13-15 de maio, 2015, Vitória, ES. Proceedings... São Paulo: Blucher Proceedings, 2015.

    Abstract: The numbers of hot stamped components have been steadily increasing in the automotive industry. Press hardened steels are generally used in hot stamping process since at the end of the process, the steel may achieve a tensile strength about 1500 MPa. The hot stamping process consists to heat the steel blank at total austenitization temperature and to transfer the blank into the press tooling for shaping and fast cooling to fully martensitic transformation. The transfer of the blank from the furnace to the press might promote at some extent, steel oxidation. The application of metallic coatings avoids this hindrance. The Al-Si has been the most applied coating on steel. In parallel, alternative coatings such as Zn-Ni have been developed. It is known that the heating causes chemical elements diffusion, which results in intermetallic formation between the elements presents in the coating and in the substrate. This study had the objective of characterizing hot stamped and coated 25MnB5 steel samples with Al-Si and Zn-Ni, with X rays diffraction (XRD) technique. Some literature suggested phases such as Zn-Fe, Zn-Ni-Fe or Al-Fe-Si were not seen on XRD results. Nonetheless, X-ray diffraction detected the presence of ZnO and α-Fe for Zn-Ni coated steel plate and Al5Fe2, AlFe3 and α-Fe for the Al-Si coated steel plate.

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  • IPEN-DOC 23815

    SILVA, M.R.M. ; FIM, R.G.T. ; SILVA, S.C. ; CASINI, J.C.S.; TAKIISHI, H. . Microestrutural and magnetic properties characterization of PrFeCoB-based alloys and permanent HD sintered magnets. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 7., 11-13 de maio, 2016, Serra, ES. Proceedings... São Paulo: Blucher Proceedings, 2016. p. 73-76.

    Abstract: The magnets were produced by powder metallurgy route, using powders obtained by hydrogenation-decrepitation method (HD). The compositions of the alloys were: Pr20FeBalB5Cu2 (33% wt.) and Pr14FebalCo16B6Nb0,1(AlSiCuGaGd)x (where x = 0,3 e 0,5) (67% wt.). The characterization of the alloys and the magnets produced have been carried out using backscattered electron microscopy (BEM), energy-dispersive X ray spectroscopy (EDXS), X ray diffraction (XRD), X ray fluorescence (XRF) and magnetic properties have been measured using a permeameter. The results revealed that the Fe-rich phase is prejudicial to magnetic properties and the improvement of the properties is due to the elimination of the Fe-rich phase by heat treatment (1343K for 20 hours). Therefore, the magnets produced by heat treated alloys presented a maximum energy product 50% higher when compared with the magnets produced by as-cast alloys. The magnet produced by Pr14FebalCo16B6Nb0,1(AlSiCuGaGd)0,5 heat treated alloy presented the best values for remanence (Br = 1.03 T), maximum energy product ((BH)máx = 201.6 KJ.m-3) and intrinsic coercivity (iHc = 716.2 KA.m-3).

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  • IPEN-DOC 23806

    MUCSI, C.S. ; REIS, L.A.M. ; ROSSI, J.L. . Study on the production of VAR electrodes from Zircaloy turning lathe chips. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 7., 11-13 de maio, 2016, Serra, ES. Proceedings... São Paulo: Blucher Proceedings, 2016. p. 50-52.

    Abstract: Zircaloy 4 chips are produced in large quantities during the machining of Zircaloy 4 rods for the PWR fuel elements parts. Currently Zircaloy 4 is a zirconium alloy imported into Brazil and the machining chips scraps poses a challenge to the recycling industry. This paper presents the first step on the recycling processes and the results for the search of an efficient way on the cleaning, quality control and Vacuum Arc Remelting (VAR) electrode fabrication. The process starts with cutting oil washout and is followed by the die pressing of the clean chips. Process evaluation was first made by means the X-ray fluorescence tests in order to define the quality of the scraps. Results indicates the need of the inclusion of a magnetic separation step in the process to withdraw the ferrous alloy present in the scraps. The die pressing of the scraps yield process adequate 1 kg electrodes to be melted in the CCTM prototype scale VAR furnace. The authors also conclude that the samples obtained from the fuel element industry are secondary scraps and suggest them a procedure for the scrap stocking.

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  • IPEN-DOC 23805

    MUCSI, C.S. ; ARANHA, L.C.; ALENCAR, M.C.; ROSSI, J.L. . Study of the strain gage signals for the control of a micro torque meter. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 6., 13-15 de maio, 2015, Vitória, ES. Proceedings... São Paulo: Blucher Proceedings, 2015.

    Abstract: The controls of the stresses on the bone-implant and implant-abutment interfaces are crucial for the performance of an implant. Dental implants are a class in itself due to its size, chemical and biological environment. This paper presents a study on the electric signals from a strain gage used in a custom-made laboratory micro torque meter specially developed to evaluate the influence of the bone-implant and implant-abutment screwed interfaces on the micro torque signals. The original electric signals were acquired via National Instruments (NI) hardware and real time processed with the Labview® software for the evaluation of noise and its relation to the physical values of interest and equipment precision. The results indicate the need of careful attention to the noise pickup, noise source controls and mechanical amplification of the original signal in order to obtain higher accuracy of the equipment and automated control on the equipment.

    Palavras-Chave: strain gages; prostheses; signals; dentistry

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  • IPEN-DOC 23796

    GUGLIOTTI, C.F. ; LIMA, N.B. ; OLIVEIRA, R.R. ; SILVA, M.R.M. ; SILVA, S.C. . Determination of the crystal alignment of SrFe12O19 permanent magnets using the (006) X-ray pole figure. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 7., 11-13 de maio, 2016, Serra, ES. Anais... São Paulo: Blucher Proceedings, 2016. p. 77-79.

    Abstract: O grau de alinhamento de ímãs permanentes de ferrita de estrôncio produzidos com diferentes tamanhos médios de partícula foi investigado utilizando análise de figura de pólo. Os ímãs foram produzidos a partir de pós sem moagem e moídos em moinho de bolas com tempos de moagem entre 60 e 360 minutos. O tamanho médio de partícula foi determinado utilizando Fisher Sub-sieve sizer e granulômetro CILAS 1064. A morfologia dos pós foram analisados utilizando imagens de MEV. Os pós foram alinhados a um campo magnético, prensados isostaticamente e sinterizados. Os ímãs foram caracterizados magneticamente utilizando um permeâmetro. O grau de alinhamento dos ímãs sinterizados foi calculado utilizando a reflexão (006) e a morfologia dos grãos do ímã foi analisada utilizando imagens de MEV. Os ímãs permanentes de ferrita de estrôncio produzidos com pós moídos apresentaram maior grau de alinhamento (0,82) quando comparados ao ímã produzido com pós não moídos (0,79).

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  • IPEN-DOC 23794

    GOMES, M.P. ; SANTOS, I.P. ; MUCSI, C.S. ; COLOSIO, M.A.; ROSSI, J.L. . Study of the mechanical and metallurgical properties of sintered steels for valve seat inserts application. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 7., 11-13 de maio, 2016, Serra, ES. Proceedings... São Paulo: Blucher Proceedings, 2016. p. 59-61.

    Abstract: The aim of this work was to study the valve seat insert (VSI) produced with three different alloys (mainly modified from the original AISI M3/2, M2 and D2 high-speed steels) from the mechanical and metallurgical point of view. These alloys modifications were intended as an alternative to replace cobalt and lead used in the original alloy due to their high cost and toxicological effect respectively. Such alloys have been developed for internal combustion engines VSI manufacture. The VSI studied in this work was previously produced by the powder metallurgy (P/M) route. The VSI production was performed using a uniaxial hydraulic press and a belt conveyor furnace. The VSI was submitted to metallic infiltration during the sintering process using copper as filler. The studies were performed according to standardized apparent density (ASTM C 373-88), apparent hardness (ASTM E 92-82) and radial crush strength (MPIF Standard 35) tests. The VSI produced with M3/2 alloy proved to be more advantageous considering the highest values obtained in the apparent hardness and radial crush strength tests.

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  • IPEN-DOC 23792

    FELICIANO, M.M. ; PERUCHI, R.F.O. ; ROSSI, J.L. ; MUCSI, C.S. . Projeto e construção de unidade de leitura de sensor Pirani para sistema de vácuo. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 7., 11-13 de maio, 2016, Serra, ES. Anais... São Paulo: Blucher Proceedings, 2016. p. 44-46.

    Abstract: O presente trabalho desenvolveu um leitor de sensor Pirani com a utilização de um microcontrolador Atmel AVR de 8 bits. O microcontrolador utilizou o padrão de programação estruturada em linguagem C, permitindo o uso de estruturas lógicas e cálculos aritméticos. Este comportamento foi utilizado para converter o sinal analógico proveniente do sensor, traduzindo-o para a apresentação em um painel de cristal líquido. O funcionamento de um sensor Pirani baseia-se na variação da resistência elétrica de uma dos ramos de uma ponte de Wheatstone em função da pressão gasosa. A tensão elétrica na ponte de Wheatstone foi mapeada para um valor de pressão gasosa, através da curva de calibração do sensor Pirani comercial, implementada no software da unidade de leitura. O equipamento desenvolvido apresentou uma performance adequada às demandas qualitativas da operação com custo de construção bastante atrativo.

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  • IPEN-DOC 23786

    CAVALHEIRA, E.D. ; MENDES, N.M.F. ; CASINI, J.C.; BARBOSA, L.P. ; SILVA, S.C. ; TAKIISHI, H. . Efeito do tamanho de partículas nas propriedades mecânicas de ligas de zircônio reprocessadas. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 7., 11-13 de maio, 2016, Serra, ES. Anais... São Paulo: Blucher Proceedings, 2016. p. 41-44.

    Abstract: A etapa de usinagem para fabricação de tubos e tampões de Zircaloy-4 (Zr-4) utilizados em reatores nucleares de potência à água pressurizada (reatores PWR’s) geram grandes quantidades de rejeitos deste material. Devido ao alto custo do Zr-4 faz-se necessário sua reciclagem, que é estratégico para o Brasil, evitando seu descarte para o meio ambiente. Neste trabalho, os rejeitos da usinagem do Zr-4 foram aquecidos em atmosfera de hidrogênio (923 K) sendo o pó resultante desta etapa peneirado em malha 200 e 325 mesh (74 e 44 μm). Nesta etapa, foram retirados os materiais que não absorvem hidrogênio proveniente da usinagem, diminuindo a contaminação final da liga Zr-4. A moagem foi realizada em moinho de alta energia, utilizando pote e esferas de zircônia para diminuir a contaminação do pó. Os experimentos foram realizados em diferentes tempos de moagem (0 a 120 min). A amostra foi prensada a 200 MPa (prensagem isotática) e sinterizada a 1423 K por 10 h. A microestrutura foi analisada por microscopia eletrônica de varredura efoi determinada a dureza Vickers. Os resultados mostraram que após 60 min de moagem o tamanho médio das partículas foi de 2,4 μm, a dureza Vickers foi de 425 HV e tamanho de grão em torno de 50 μm. As amostras apresentaram valores de densidade hidrostática de 99% em relação à teórica, e a microestrutura apresentou morfologia típica do Zr-4da fase α e grãos equiaxiais.

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  • IPEN-DOC 23814

    SILVA, M.J. da; KARCZEWSKI, J.; JASINSKI, P.; CHRZAN, A.; KALINOWSKI, P.; SZYMCZEWSKA, D.; JASINSKI, G.. Barium boron aluminum silicate glass system for solid state optical gas sensors. In: JASINSKI, PIOTR (Ed.) INTERNATIONAL CONFERENCE ON OPTICAL AND ELECTRONIC SENSORS, 14th, June 19, 2016, Gdansk, Poland. Proceedings... Bellingham, Washington USA: Society of Photo-optical Instrumentation Engineers, 2016. p. 101610G-1 - 101610G-9. (SPIE Proceedings Series, 10161).

    Abstract: Recent increasing demand for new eco-friendly materials and for low cost fabrication process for use in optical sensors field, raise concern about alternative materials for this application. We have designed two glass-ceramics compositions from the quaternary ROAl2O3- SiO2-B2O3(R=Ba) alkali-earth aluminum silicate system, labeled B72 and B69, with high refractive index (>1.6), large values of Abbe number (94.0 and 53.0, respectively), and free of lead and arsenic. We present an analysis and discussion of experimental optical properties, thermal and thermo-chemical stability along with important properties such as transition temperature (Tg), onset of crystallization (Tx) as well transport properties as ionic conductivity behavior in the quaternary glass-ceramic system containing boron for use as optical sensors. Complex Impedance Spectra (Bode Plot) and Potentiodynamic Polarization curves (Tafel plots) measurements were carried out in the temperature range of 600 to 850ºC. The most probable conductivity mechanism is a thermally activated process of mobile ions overcoming a potential barrier (EA), according to the Arrhenius regime. Here we report that charge transfer is caused by the flux of electrons, in the region of elevated temperatures (>700°C), and is affected by immiscibility of crystals, nucleation and growth type, that causes phase separation. We found conductivity (σ) values from 10-9 to 10-5 S/cm at temperatures between 700 and 850ºC. Our results highlight a need for research on ion mobility in the glassy network above the transition range, and the effect cause by metastable immiscibility in the alkaline-earth glasses are exposed. The two glass compositions B72 and B69 can be tailored by proper use as glassy optical sensor.

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  • IPEN-DOC 23789

    COSTA, RENATA F. da; MARQUES, MARCIA T.A. ; LOPES, DANIEL S.; GUARDANI, MARIA L.G.; MACEDO, FERNANDA de M. ; LANDULFO, EDUARDO ; GUARDANI, ROBERTO. Monitoring the environmental impact of aerosol loading and dispersion from distinct industrial sources in Cubatao, Brazil, using a scanning lidar. In: SINGH, UPENDRA N. (Ed.); NICOLAE, DOINA N. (Ed.) LIDAR TECHNOLOGIES, TECHNIQUES, AND MEASUREMENTS FOR ATMOSPHERIC REMOTE SENSING, 12th, September 26, 2016, Edinburgh, United Kingdom. Proceedings... Bellingham, Washington USA: Society of Photo-optical Instrumentation Engineers, 2016. p. 1000608-1 - 1000608-8. (SPIE Proceedings Series, 10006).

    Abstract: This paper reports the results of campaigns carried out with a scanning lidar system in an industrial area for monitoring the spatial distribution of atmospheric aerosol. The aim of the study was to verify the possibility of applying a lidar system to identify fixed sources of aerosol emission, as well as to monitor the dispersion of the emitted plume, and the ability of the system to evaluate pertinent properties of the suspended particles, such as particle number concentration and representative particle size. The data collection was carried out with a scanning backscatter lidar system in the biaxial mode with a three-wavelength light source, based on a commercial Nd:YAG laser, operating at 355 nm, 532 nm, and 1064 nm. The campaigns were carried out in an industrial site close to the city of Cubatao, Brazil, 23º 53’ S and 46º 25’ W, one of the largest industrial sites of the Country, comprising a steel plant, two fertilizer complexes, a cement plant and a petrochemical complex. Backscattered light intensity plots were made from the primary data collected via 360-degree scans at 15 degree elevation. The collected data correspond to distances ranging from 200 m to 1500 m from the measurement location. The results indicate that the technique can provide valuable information on the spatial and temporal distribution of aerosol concentration in the area, which therefore can represent a valuable tool in source apportionment and to validate plume dispersion models.

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  • IPEN-DOC 23822

    RAELE, MARCUS P. ; PRETTO, LUCAS R. de ; SAMAD, RICARDO E. ; FREITAS, ANDERSON Z. de ; ROSSI, WAGNER de ; VIEIRA JUNIOR, NILSON D. ; WETTER, NIKLAUS U. . Development of a dynamic interferometric focusing system for femtosecond laser machining. In: HEISTERKAMP, ALEXANDER (Ed.); HERMAN, PETER R. (Ed.); MEUNIER, MICHEL (Ed.); OSELLAME, ROBERTO (Ed.) FRONTIERS IN ULTRAFAST OPTICS: BIOMEDICAL, SCIENTIFIC, AND INDUSTRIAL APPLICATIONS, 18th, January 28, 2017, San Francisco, California, United States. Proceedings... Bellingham, Washington USA: Society of Photo-optical Instrumentation Engineers, 2017. p. 100940N-1 - 100940N-13. (SPIE Proceedings Series, 10094).

    Abstract: Taking advantage of the inherent characteristics of femtosecond laser used for machining, we developed an interferometric system able to evaluate and correct the focal position with an accuracy of a few microns, implementing a technique based on low coherence interferometry. This approach measures at the exact spot that the laser is machining, in real time, and is sensitive to any sample that acts as a scatterer to the wavelength in use. The experimental evaluation was divided in two steps: in the first a system based on a superluminescent LED was mounted to check the viability and develop the controlling software; in the second part a setup was mounted employing a femtosecond laser, and several kinds of samples using the active focus control, among which the results obtained with glass sample and a bovine tooth are meticulously described in this paper. The system was able to improve the performance in both samples, keeping them in the confocal region for an extended positioning range, resulting in better engraving by the laser.

    Palavras-Chave: laser beam machining; lasers; interferometry; laser radiation; ablation; michelson interferometer; cattle; teeth; bone tissues

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