Walmir Belinato | IFBA - Academia.edu (original) (raw)

Papers by Walmir Belinato

Research paper thumbnail of Virtual Laboratory of Ionizing Radiation Metrology: Validation by spectrometry

Journal of Physics: Conference Series

The digital revolution is a reality. Many areas of industry, services as well as other applicatio... more The digital revolution is a reality. Many areas of industry, services as well as other applications fields, are migrating part of their jobs - even the totality - to the digital environment. Ionizing radiation metrology cannot be out of this world. For this objective, the creation of a virtual environment from the physical systems of radiation meter calibration has been proposed. The methodology tools used consist of describing all the key elements of this laboratory in Monte Carlo, using EGSnrc and egs_phd application, to simulate them and to validate the system comparing it with experimental data in the same condition. In this context, the N60 radiation quality, from ISO 4037-1, was chosen for this purpose. An AMPTEK XR-100T CdTe was used on spectrometry, and the spectra were corrected based on the Stripping method. The results showed a good agreement between experimental and simulated spectra, with a difference in their mean energy of 1.4% within the ±5% tolerance range required ...

Research paper thumbnail of Experimentos De Baixo Custo: Estratégias Para a Melhoria Do Ensino De Física No Ensino Médio

Editora Científica Digital eBooks, 2022

Research paper thumbnail of O Uso De Experimentos De Baixo Custo No Ensino De Física Do Ensino Médio

Seminário Nacional e Seminário Internacional Políticas Públicas, Gestão e Práxis Educacional, Jul 11, 2019

Research paper thumbnail of Dosimetric evaluation in brachytherapy and teletherapy for prostate cancer using Monte Carlo simulation and anatomically realistic virtual anthropomorphic phantom

Radiation Physics and Chemistry

Research paper thumbnail of Evaluation of the radiation shielding properties of ornamental rocks produced in Brazil: A Monte Carlo approach

Brazilian Journal of Radiation Sciences

In this work, the Monte Carlo MCNPX (2.7.0) code was used to evaluate the radioprotective propert... more In this work, the Monte Carlo MCNPX (2.7.0) code was used to evaluate the radioprotective properties of ten ornamental granitic samples produced in Brazil. For each sample of granite, the mass attenuation coefficient (µ/ρ) and half-value layer (HVL) were evaluated using the photon energy emitted by the following radioisotopes: 241Am (59,5 keV), 133Ba (356 keV), 137Cs (662 keV), 60Co (1250 keV), and 22Na (1274 keV). The MCNPX results showed agreement with the values obtained by using the XCOM database, as well as with theoretical and experimental results, available on the literature. The computational model built in this work can be used by the scientific community interested in parameters involving new materials for gamma radiation shielding, which has been used in different areas of the nuclear sciences.

Research paper thumbnail of Estudo do material do eletrodo coletor de uma câmara de extrapolação por simulação de Monte Carlo

In this work, the influence of different materials of the collecting electrode on the response of... more In this work, the influence of different materials of the collecting electrode on the response of an extrapolation ionization chamber, was evaluated. This ionization chamber was simulated with the MCNP-4C Monte Carlo code and the spectrum of a standard diagnostic radiology beam (RQR5) was utilized. The different results are due to interactions of photons with different materials of the collecting electrode contributing with different values of energy deposited in the sensitive volume of the ionization chamber, which depends on the atomic number of the evaluated materials. The material that presented the least influence was graphite, the original constituent of the ionization chamber.

Research paper thumbnail of Medical and Occupational Dosimetry During Interventional Pediatric Cardiology Procedures: A Monte Carlo Approach

Research paper thumbnail of Computational dose evaluation on children exposed to natural radioactivity from granitic rocks used as architectural materials

Journal of Radiological Protection, Jan 18, 2022

Considering the higher radiosensitivity of children in comparison to adults, studies related to c... more Considering the higher radiosensitivity of children in comparison to adults, studies related to children’s exposure to ionising radiation have been long considered of relevance. For this study, the MCNPX2.7.0 Monte Carlo code and four paediatric voxel computational anthropomorphic phantoms, of both genders and aged 5 and 10 years, were used to simulate scenarios, where children are exposed to natural radiation emitted by sources in the ground by radionuclides of 40K and of 232Th and 238U radioactive series. These elements are part of the composition of ten different types of ornamental rocks obtained from three regions of Brazil, and used as architectural material for flooring of houses. The virtual paediatric anthropomorphic phantoms were positioned in a room with dimensions of (4.0 × 5.0 × 2.8) m3 filled with atmospheric air and a 3 cm thick granitic floor acting as a uniformly distributed planar gamma radiation source. The walls of the room were composed of 20 cm thick concrete. Gonads, bone marrow, bladder, colon, and skin were found to be the organs which receive the highest doses. The mean values of effective dose per air kerma at 1 m above the ground summed for all three radionuclides, were 0.96 and 0.68 Sv Gy−1 for the 5 and 10 year old phantoms, respectively. The obtained results showed that the granitic rocks considered implicate annual effective doses which are 69%–78% lower than the annual limits, recommended by ICRP Publication 103.

Research paper thumbnail of Dosimetry in Digital Breast Tomosynthesis Evaluated by Monte Carlo Technique

Health Physics, Apr 20, 2021

The influence of the angular deviation of the tube during digital breast tomosynthesis (DBT) acqu... more The influence of the angular deviation of the tube during digital breast tomosynthesis (DBT) acquisition to the dose in the examined breast and in other organs and tissues is not well known. In this work, the Monte Carlo method was used with an adult female virtual anthropomorphic phantom to investigate the impact of this angular variation on the breast dose. The absorbed dose in the examined breast was normalized by the air kerma, which resulted in an absorbed dose coefficient (DT/Kair) for the breast. The absorbed dose in each organ was normalized by the glandular dose in the breast, resulting in the relative organ dose (ROD). An adult female virtual anthropomorphic phantom (FSTA_M50_H50) was incorporated into a scenario containing tomosynthesis equipment with Mo/Mo, Mo/Rh, and W/Rh target/filter combinations and tube voltages of 28 kV. The comparison between the results of the simulations considering digital mammography (DM) and DBT data showed that the DT/Kair values for the examined breast obtained with the DBT parameters were up to 24 times higher than with the DT/Kair obtained with DM parameters. A DT/Kair of 0.97 × 10−1 mGy mGy−1 was obtained in a DBT exam of the right breast. Considering the other organs, the highest ROD values were observed in the thyroid (6.45 × 10−4), eyes (3.87 × 10−4), liver (1.95 × 10−5), and eye lenses (3.21 × 10−3). A variation in the absorbed dose values for the breast and other organs was observed for all projections different from 0°.

Research paper thumbnail of Estimated risk of radiation-induced cancer following breast screening employing tomosynthesis and digital mammography

Journal of Radiological Protection, Jun 1, 2021

The objective of this study was to estimate the risk of radiation-induced injury to the organs du... more The objective of this study was to estimate the risk of radiation-induced injury to the organs due to ionizing radiation following breast screening recommendations employing digital breast tomosynthesis (DBT) and digital mammography (DM). Using the Monte Carlo method, absorbed doses in the tissues and organs were calculated on an adult female phantom, considering two-view craniocaudal (CC) and mediolateral oblique (MLO) projections for each breast. The results showed differences in the total effective risk due to DM (CC + MLO) and DBT (CC + MLO) examinations in Brazil, ranging from 20.73 cases 10−5 (DM) to 27.19 cases 10−5 (DBT). Significant differences were also observed in the total effective risk of cancer incidence in the lungs due to DM (CC + MLO) and DBT (CC + MLO), ranging from 1.75×10−01 cases 10−5 (DM) to 1.76×10−01 cases 10−5 (DBT). The results indicate that the total effective risk of incidence should be considered as an additional parameter for the evaluation of DBT or DBT + DM program performance.

Research paper thumbnail of Exposure to<sup>137</sup>Cs deposited in soil – A Monte Carlo study

Journal of physics, Mar 1, 2018

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

Research paper thumbnail of Evaluation of the effect of silicone implants in a breast radiotherapy treatment: A Monte Carlo approach

Radiation Physics and Chemistry

Research paper thumbnail of Evaluation of the Effect of Silicone Implants in a Breast Radiotherapy Treatment with Monte Carlo Simulation

Physica Medica, Dec 1, 2022

Research paper thumbnail of Confecção De Experimentos De Mecânica Voltados a Alunos Das Séries Iniciais Do Ensino Médio

Pesquisas e Inovações em Engenharias, Ciências Exatas e da Terra: Produções Científicas Multidisciplinares no Século XXI, Volume 2

Os anos iniciais do ensino médio são como uma experiência nova para os alunos, os quais se depara... more Os anos iniciais do ensino médio são como uma experiência nova para os alunos, os quais se deparam com dificuldades em compreender conteúdos das ciências exatas e, principalmente de física. Muitas vezes a prática de atividades experimentais num contexto didático metodológico que colabore para uma aprendizagem satisfatória dos conceitos físicos é de praxe utilizada por professores. Neste capítulo, buscamos instigar a prática da experimentação com materiais alternativos para alunos dos primeiros anos do ensino médio, como um método de desencadeamento da criatividade e da percepção dos alunos de que a Física é algo que está presente em suas vidas, proporcionando assim uma aprendizagem significativa e de grande valor para o estudante.

Research paper thumbnail of Comparação da eficiência de diferentes materiais de dosímetros LOE com simulação Monte Carlo

XIII SEB, 2021

Computer Simulations are widely used today, especially in medical areas where ionizing radiation ... more Computer Simulations are widely used today, especially in medical areas where ionizing radiation is used for treatments and diagnostics. In this work, we use the MCNP 6.2 Monte Carlo code to compare the efficiency of some OSL dosimeters with different dopants. It may be seen that the dosimeters response to radiation depends on the number of dopants and the material chosen for this purpose. The material Al2O3:C showed a higher energy deposition in all the tube voltages tested in this work (25 kV, 50 kV, 75 kV and 100 kV) compared to the other two materials evaluated in this work: BeO and MgB4O7:Ce, Li.

Research paper thumbnail of Ensino De Física: O Uso De Experimentos De Baixo Custo Como Estrategia De Ensino / Physics Teaching: The Use of Low Cost Experiments as a Teaching Strategy

Brazilian Journal of Development, 2020

Ensino de física: O uso de experimentos de baixo custo como estrategia de ensino Physics teaching... more Ensino de física: O uso de experimentos de baixo custo como estrategia de ensino Physics teaching: The use of low cost experiments as a teaching strategy

Research paper thumbnail of Computational evaluation of a pencil ionization chamber in a standard diagnostic radiology beam

In this work a pencil ionization chamber was evaluated. This evaluation consisted in the determin... more In this work a pencil ionization chamber was evaluated. This evaluation consisted in the determination of the influence of the ionization chamber components in its response. For this purpose, the Monte Carlo simulations and the spectrum of the standard diagnostic radiology beam (RQR5) were utilized. The results obtained, showed that the influence of the ionization chamber components presented no significant influence on the chamber response. Therefore, this ionization chamber is a good alternative for dosimetry in diagnostic radiology.

Research paper thumbnail of Otimização dos custos com iluminação dos ambientes de estudo no IFBA Campus Vitória da conquista utilizando a programação linear / Optimization of lighting costs in study areas on IFBA Campus Vitória da conquista using linear programming

O metodo simplex e compreendido como uma tecnica numerica para a solucao otimizada de um modelo l... more O metodo simplex e compreendido como uma tecnica numerica para a solucao otimizada de um modelo linear. Diante da reducao de recursos cada vez maior para as instituicoes publicas ocorrida nos ultimos anos, ha um interesse por parte dos gestores em localizar setores onde seja possivel reduzir custos. O objetivo deste trabalho e a busca da reducao de gastos com energia eletrica na iluminacao de areas de estudo (salas) no IFBA-Campus Vitoria da Conquista, aplicando o metodo simplex, utilizando a ferramenta solver, do Microsoft Excel. Para elaboracao deste trabalho, coletou-se dados relacionados ao numero de salas, numero de lâmpadas, fator de iluminacao, area iluminada, potencia das lâmpadas, fator de potencia das lâmpadas, valor do kWh cobrado pela empresa distribuidora de energia, uso medio mensal de cada lâmpada, para a elaboracao de um modelo matematico linear, passivel de solucao. Foram realizadas simulacoes considerando custos envolvendo as trocas de lâmpadas fluorescente por lâm...

Research paper thumbnail of Dosimetria de pacientes adultos e pediátricos empregando método de Monte Carlo em PET/CT

A tomografia por emissao de positrons (PET), associada a tomografia computadorizada (CT), e uma t... more A tomografia por emissao de positrons (PET), associada a tomografia computadorizada (CT), e uma tecnica diagnostica da medicina nuclear chamada de PET/CT. E possivel estimar coeficientes de conversao para dose absorvida em PET/CT por meio de simulacoes computacionais realizadas com o metodo de Monte Carlo. A proposta principal deste trabalho foi, utilizando o codigo MCNPX, estudar as doses absorvidas em orgaos internos de pacientes em decorrencia de exames de PET/CT. Para isso, foram empregados simuladores antropomorficos computacionais com representacao dos orgaos e estruturas internas realistas de pacientes adultos e pediatricos incorporados em cenarios de radiacao de dois equipamentos PET/CT, modelos Discovery VCT (GE) e Biograph (Siemens). Foram considerados seis diferentes tipos de radionuclideos emissores de positrons. Variacoes morfologicas devido ao efeito gravitacional foram tambem levados em conta para os simuladores adultos. O segundo objetivo foi construir um objeto simu...

Research paper thumbnail of May the Odds Be with You - Seasonal and Multiseasonal Prediction

Weather and Climate, 1996

Research paper thumbnail of Virtual Laboratory of Ionizing Radiation Metrology: Validation by spectrometry

Journal of Physics: Conference Series

The digital revolution is a reality. Many areas of industry, services as well as other applicatio... more The digital revolution is a reality. Many areas of industry, services as well as other applications fields, are migrating part of their jobs - even the totality - to the digital environment. Ionizing radiation metrology cannot be out of this world. For this objective, the creation of a virtual environment from the physical systems of radiation meter calibration has been proposed. The methodology tools used consist of describing all the key elements of this laboratory in Monte Carlo, using EGSnrc and egs_phd application, to simulate them and to validate the system comparing it with experimental data in the same condition. In this context, the N60 radiation quality, from ISO 4037-1, was chosen for this purpose. An AMPTEK XR-100T CdTe was used on spectrometry, and the spectra were corrected based on the Stripping method. The results showed a good agreement between experimental and simulated spectra, with a difference in their mean energy of 1.4% within the ±5% tolerance range required ...

Research paper thumbnail of Experimentos De Baixo Custo: Estratégias Para a Melhoria Do Ensino De Física No Ensino Médio

Editora Científica Digital eBooks, 2022

Research paper thumbnail of O Uso De Experimentos De Baixo Custo No Ensino De Física Do Ensino Médio

Seminário Nacional e Seminário Internacional Políticas Públicas, Gestão e Práxis Educacional, Jul 11, 2019

Research paper thumbnail of Dosimetric evaluation in brachytherapy and teletherapy for prostate cancer using Monte Carlo simulation and anatomically realistic virtual anthropomorphic phantom

Radiation Physics and Chemistry

Research paper thumbnail of Evaluation of the radiation shielding properties of ornamental rocks produced in Brazil: A Monte Carlo approach

Brazilian Journal of Radiation Sciences

In this work, the Monte Carlo MCNPX (2.7.0) code was used to evaluate the radioprotective propert... more In this work, the Monte Carlo MCNPX (2.7.0) code was used to evaluate the radioprotective properties of ten ornamental granitic samples produced in Brazil. For each sample of granite, the mass attenuation coefficient (µ/ρ) and half-value layer (HVL) were evaluated using the photon energy emitted by the following radioisotopes: 241Am (59,5 keV), 133Ba (356 keV), 137Cs (662 keV), 60Co (1250 keV), and 22Na (1274 keV). The MCNPX results showed agreement with the values obtained by using the XCOM database, as well as with theoretical and experimental results, available on the literature. The computational model built in this work can be used by the scientific community interested in parameters involving new materials for gamma radiation shielding, which has been used in different areas of the nuclear sciences.

Research paper thumbnail of Estudo do material do eletrodo coletor de uma câmara de extrapolação por simulação de Monte Carlo

In this work, the influence of different materials of the collecting electrode on the response of... more In this work, the influence of different materials of the collecting electrode on the response of an extrapolation ionization chamber, was evaluated. This ionization chamber was simulated with the MCNP-4C Monte Carlo code and the spectrum of a standard diagnostic radiology beam (RQR5) was utilized. The different results are due to interactions of photons with different materials of the collecting electrode contributing with different values of energy deposited in the sensitive volume of the ionization chamber, which depends on the atomic number of the evaluated materials. The material that presented the least influence was graphite, the original constituent of the ionization chamber.

Research paper thumbnail of Medical and Occupational Dosimetry During Interventional Pediatric Cardiology Procedures: A Monte Carlo Approach

Research paper thumbnail of Computational dose evaluation on children exposed to natural radioactivity from granitic rocks used as architectural materials

Journal of Radiological Protection, Jan 18, 2022

Considering the higher radiosensitivity of children in comparison to adults, studies related to c... more Considering the higher radiosensitivity of children in comparison to adults, studies related to children’s exposure to ionising radiation have been long considered of relevance. For this study, the MCNPX2.7.0 Monte Carlo code and four paediatric voxel computational anthropomorphic phantoms, of both genders and aged 5 and 10 years, were used to simulate scenarios, where children are exposed to natural radiation emitted by sources in the ground by radionuclides of 40K and of 232Th and 238U radioactive series. These elements are part of the composition of ten different types of ornamental rocks obtained from three regions of Brazil, and used as architectural material for flooring of houses. The virtual paediatric anthropomorphic phantoms were positioned in a room with dimensions of (4.0 × 5.0 × 2.8) m3 filled with atmospheric air and a 3 cm thick granitic floor acting as a uniformly distributed planar gamma radiation source. The walls of the room were composed of 20 cm thick concrete. Gonads, bone marrow, bladder, colon, and skin were found to be the organs which receive the highest doses. The mean values of effective dose per air kerma at 1 m above the ground summed for all three radionuclides, were 0.96 and 0.68 Sv Gy−1 for the 5 and 10 year old phantoms, respectively. The obtained results showed that the granitic rocks considered implicate annual effective doses which are 69%–78% lower than the annual limits, recommended by ICRP Publication 103.

Research paper thumbnail of Dosimetry in Digital Breast Tomosynthesis Evaluated by Monte Carlo Technique

Health Physics, Apr 20, 2021

The influence of the angular deviation of the tube during digital breast tomosynthesis (DBT) acqu... more The influence of the angular deviation of the tube during digital breast tomosynthesis (DBT) acquisition to the dose in the examined breast and in other organs and tissues is not well known. In this work, the Monte Carlo method was used with an adult female virtual anthropomorphic phantom to investigate the impact of this angular variation on the breast dose. The absorbed dose in the examined breast was normalized by the air kerma, which resulted in an absorbed dose coefficient (DT/Kair) for the breast. The absorbed dose in each organ was normalized by the glandular dose in the breast, resulting in the relative organ dose (ROD). An adult female virtual anthropomorphic phantom (FSTA_M50_H50) was incorporated into a scenario containing tomosynthesis equipment with Mo/Mo, Mo/Rh, and W/Rh target/filter combinations and tube voltages of 28 kV. The comparison between the results of the simulations considering digital mammography (DM) and DBT data showed that the DT/Kair values for the examined breast obtained with the DBT parameters were up to 24 times higher than with the DT/Kair obtained with DM parameters. A DT/Kair of 0.97 × 10−1 mGy mGy−1 was obtained in a DBT exam of the right breast. Considering the other organs, the highest ROD values were observed in the thyroid (6.45 × 10−4), eyes (3.87 × 10−4), liver (1.95 × 10−5), and eye lenses (3.21 × 10−3). A variation in the absorbed dose values for the breast and other organs was observed for all projections different from 0°.

Research paper thumbnail of Estimated risk of radiation-induced cancer following breast screening employing tomosynthesis and digital mammography

Journal of Radiological Protection, Jun 1, 2021

The objective of this study was to estimate the risk of radiation-induced injury to the organs du... more The objective of this study was to estimate the risk of radiation-induced injury to the organs due to ionizing radiation following breast screening recommendations employing digital breast tomosynthesis (DBT) and digital mammography (DM). Using the Monte Carlo method, absorbed doses in the tissues and organs were calculated on an adult female phantom, considering two-view craniocaudal (CC) and mediolateral oblique (MLO) projections for each breast. The results showed differences in the total effective risk due to DM (CC + MLO) and DBT (CC + MLO) examinations in Brazil, ranging from 20.73 cases 10−5 (DM) to 27.19 cases 10−5 (DBT). Significant differences were also observed in the total effective risk of cancer incidence in the lungs due to DM (CC + MLO) and DBT (CC + MLO), ranging from 1.75×10−01 cases 10−5 (DM) to 1.76×10−01 cases 10−5 (DBT). The results indicate that the total effective risk of incidence should be considered as an additional parameter for the evaluation of DBT or DBT + DM program performance.

Research paper thumbnail of Exposure to<sup>137</sup>Cs deposited in soil – A Monte Carlo study

Journal of physics, Mar 1, 2018

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

Research paper thumbnail of Evaluation of the effect of silicone implants in a breast radiotherapy treatment: A Monte Carlo approach

Radiation Physics and Chemistry

Research paper thumbnail of Evaluation of the Effect of Silicone Implants in a Breast Radiotherapy Treatment with Monte Carlo Simulation

Physica Medica, Dec 1, 2022

Research paper thumbnail of Confecção De Experimentos De Mecânica Voltados a Alunos Das Séries Iniciais Do Ensino Médio

Pesquisas e Inovações em Engenharias, Ciências Exatas e da Terra: Produções Científicas Multidisciplinares no Século XXI, Volume 2

Os anos iniciais do ensino médio são como uma experiência nova para os alunos, os quais se depara... more Os anos iniciais do ensino médio são como uma experiência nova para os alunos, os quais se deparam com dificuldades em compreender conteúdos das ciências exatas e, principalmente de física. Muitas vezes a prática de atividades experimentais num contexto didático metodológico que colabore para uma aprendizagem satisfatória dos conceitos físicos é de praxe utilizada por professores. Neste capítulo, buscamos instigar a prática da experimentação com materiais alternativos para alunos dos primeiros anos do ensino médio, como um método de desencadeamento da criatividade e da percepção dos alunos de que a Física é algo que está presente em suas vidas, proporcionando assim uma aprendizagem significativa e de grande valor para o estudante.

Research paper thumbnail of Comparação da eficiência de diferentes materiais de dosímetros LOE com simulação Monte Carlo

XIII SEB, 2021

Computer Simulations are widely used today, especially in medical areas where ionizing radiation ... more Computer Simulations are widely used today, especially in medical areas where ionizing radiation is used for treatments and diagnostics. In this work, we use the MCNP 6.2 Monte Carlo code to compare the efficiency of some OSL dosimeters with different dopants. It may be seen that the dosimeters response to radiation depends on the number of dopants and the material chosen for this purpose. The material Al2O3:C showed a higher energy deposition in all the tube voltages tested in this work (25 kV, 50 kV, 75 kV and 100 kV) compared to the other two materials evaluated in this work: BeO and MgB4O7:Ce, Li.

Research paper thumbnail of Ensino De Física: O Uso De Experimentos De Baixo Custo Como Estrategia De Ensino / Physics Teaching: The Use of Low Cost Experiments as a Teaching Strategy

Brazilian Journal of Development, 2020

Ensino de física: O uso de experimentos de baixo custo como estrategia de ensino Physics teaching... more Ensino de física: O uso de experimentos de baixo custo como estrategia de ensino Physics teaching: The use of low cost experiments as a teaching strategy

Research paper thumbnail of Computational evaluation of a pencil ionization chamber in a standard diagnostic radiology beam

In this work a pencil ionization chamber was evaluated. This evaluation consisted in the determin... more In this work a pencil ionization chamber was evaluated. This evaluation consisted in the determination of the influence of the ionization chamber components in its response. For this purpose, the Monte Carlo simulations and the spectrum of the standard diagnostic radiology beam (RQR5) were utilized. The results obtained, showed that the influence of the ionization chamber components presented no significant influence on the chamber response. Therefore, this ionization chamber is a good alternative for dosimetry in diagnostic radiology.

Research paper thumbnail of Otimização dos custos com iluminação dos ambientes de estudo no IFBA Campus Vitória da conquista utilizando a programação linear / Optimization of lighting costs in study areas on IFBA Campus Vitória da conquista using linear programming

O metodo simplex e compreendido como uma tecnica numerica para a solucao otimizada de um modelo l... more O metodo simplex e compreendido como uma tecnica numerica para a solucao otimizada de um modelo linear. Diante da reducao de recursos cada vez maior para as instituicoes publicas ocorrida nos ultimos anos, ha um interesse por parte dos gestores em localizar setores onde seja possivel reduzir custos. O objetivo deste trabalho e a busca da reducao de gastos com energia eletrica na iluminacao de areas de estudo (salas) no IFBA-Campus Vitoria da Conquista, aplicando o metodo simplex, utilizando a ferramenta solver, do Microsoft Excel. Para elaboracao deste trabalho, coletou-se dados relacionados ao numero de salas, numero de lâmpadas, fator de iluminacao, area iluminada, potencia das lâmpadas, fator de potencia das lâmpadas, valor do kWh cobrado pela empresa distribuidora de energia, uso medio mensal de cada lâmpada, para a elaboracao de um modelo matematico linear, passivel de solucao. Foram realizadas simulacoes considerando custos envolvendo as trocas de lâmpadas fluorescente por lâm...

Research paper thumbnail of Dosimetria de pacientes adultos e pediátricos empregando método de Monte Carlo em PET/CT

A tomografia por emissao de positrons (PET), associada a tomografia computadorizada (CT), e uma t... more A tomografia por emissao de positrons (PET), associada a tomografia computadorizada (CT), e uma tecnica diagnostica da medicina nuclear chamada de PET/CT. E possivel estimar coeficientes de conversao para dose absorvida em PET/CT por meio de simulacoes computacionais realizadas com o metodo de Monte Carlo. A proposta principal deste trabalho foi, utilizando o codigo MCNPX, estudar as doses absorvidas em orgaos internos de pacientes em decorrencia de exames de PET/CT. Para isso, foram empregados simuladores antropomorficos computacionais com representacao dos orgaos e estruturas internas realistas de pacientes adultos e pediatricos incorporados em cenarios de radiacao de dois equipamentos PET/CT, modelos Discovery VCT (GE) e Biograph (Siemens). Foram considerados seis diferentes tipos de radionuclideos emissores de positrons. Variacoes morfologicas devido ao efeito gravitacional foram tambem levados em conta para os simuladores adultos. O segundo objetivo foi construir um objeto simu...

Research paper thumbnail of May the Odds Be with You - Seasonal and Multiseasonal Prediction

Weather and Climate, 1996