Busque na ABFM:
Esqueci minha senha
Programa de cooperação com a França seleciona 30 projetos de pesquisa
"Foi divulgado nesta segunda-feira, 22/11, o resultado do programa de cooperação acadêmica com a França Capes-Cofecub Foram aprovados 30 projetos de pesquisa, nas mais variadas áreas do conhecimento promovidas por instituições de quatro regiões brasileiras. Os projetos conjuntos de pesquisa selecionados terão início em março de 2011 e deverão conter planejamento de atividades com duração máxima de quatro anos. A iniciativa é fruto da parceria entre a Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes) e o Comitê Francês de Avaliação da Cooperação Universitária e Científica com o Brasil (Cofecub). Entre os benefícios aos projetos selecionados estão financiamento de missões de trabalho e estudo e recursos de custeio à equipe brasileira, no valor de R$ 10 mil anual, que devem ser utilizados conforme previsto no Manual de Concessão de Prestação de Contas de Auxílio Financeiro a Pesquisador. " [+ leia mais]
Colaborador: Camila de Sales
Fonte: Jornal da Ciência
A method of estimating conceptus doses resulting from multidetector CT examinations during all stages of gestation
"Med. Phys. 37, 6411 (2010); doi:10.1118/1.3517187 (10 pages) Purpose: Current methods for the estimation of conceptus dose from multidetector CT (MDCT) examinations performed on the mother provide dose data for typical protocols with a fixed scan length. However, modified low-dose imaging protocols are frequently used during pregnancy. The purpose of the current study was to develop a method for the estimation of conceptus dose from any MDCT examination of the trunk performed during all stages of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study to model the Siemens Sensation 16 and Sensation 64 MDCT scanners. Four mathematical phantoms were used, simulating women at 0, 3, 6, and 9 months of gestation. The contribution to the conceptus dose from single simulated scans was obtained at various positions across the phantoms. To investigate the effect of maternal body size and conceptus depth on conceptus dose, phantoms of different sizes were produced by adding layers of adipose tissue around the trunk of the mathematical phantoms. To verify MCNP results, conceptus dose measurements were carried out by means of three physical anthropomorphic phantoms, simulating pregnancy at 0, 3, and 6 months of gestation and thermoluminescence dosimetry (TLD) crystals. Results: The results consist of Monte Carlo-generated normalized conceptus dose coefficients for single scans across the four mathematical phantoms. These coefficients were defined as the conceptus dose contribution from a single scan divided by the CTDI free-in-air measured with identical scanning parameters. Data have been produced to take into account the effect of maternal body size and conceptus position variations on conceptus dose. Conceptus doses measured with TLD crystals showed a difference of up to 19% compared to those estimated by mathematical simulations. Conclusions: Estimation of conceptus doses from MDCT examinations of the trunk performed on pregnant patients during all stages of gestation can be made using the method developed in the current study. © 2010 American Association of Physicists in Medicine " [+ leia mais]
Fonte: Medical Physics
Acoustic radiation force contrast in MRI: Detection of calcifications in tissue-mimicking phantoms
"Purpose: Mammography is a widely used tool for the screening of breast cancer, and calcifications are a common finding in most mammograms. The location, size, number, morphology, and distribution of calcifications are an important information to differentiate a benign lesion from probably malignant pathologies. Calcifications are not detectable with a standard dynamic contrast enhanced breast MRI. The authors present a novel method for the detection and imaging of calcifications in breast tissue without ionizing radiation or contrast agents. Methods: Measurements of localized tissue displacement in phantoms due to applied acoustic radiation force were performed. This displacement was imaged with a displacement sensitive spin-echo MRI sequence. Pieces of eggshell that represent calcifications were embedded in tissue-mimicking agarose phantoms. The sizes of the calcifications were 0.8×0.8×0.4, 1.5×1.5×0.4, and 2×3×0.4 mm3. The calcifications were scanned with ultrasound (U.S.) at 2.5 MHz and intensities up to Ispta = 7.18 W/cm2. The U.S. beam was moved inside the phantom by a computer-controlled three-dimensional hydraulic positioning system. The U.S. beam was scanned over the two smaller calcifications with the displacement sensitivity of the MRI sequence parallel to the U.S. beam path. Grayscale coded maps of the displacement scans are presented. For the 0.8×0.8×0.4 mm3 calcification, the U.S. intensities were varied. Finite element simulations were performed to verify if the experiments complied with theory. Results: The authors found that the displacement caused by the U.S. is increased at the position of the calcification. The area of increased displacement is at least twice as large as the calcification itself. The simulations show this increase in displacement and area at the position of the calcification. When changing the displacement sensitivity direction to perpendicular to the U.S. beam, a crossed black and white four-leaf clover is visible at the position of the calcification. Conclusions: The U.S. is scattered and reflected by the calcifications. This leads to the increased displacement which is transmitted to the surrounding material because of the elastic coupling between the calcification and the agarose material. Due to the high differences in acoustic impedance and elastic properties between the surrounding tissue and the calcification, even the detection of pieces smaller than the resolution of the MRI scanner is possible. The acoustic radiation force contrast in MR phase-difference images offers a positive signal for calcifications from a smooth background in phantoms. This method offers a possibility of differentiating qualitatively and quantitatively hard calcifications from stiffer inclusions such as tumors. © 2010 American Association of Physicists in Medicine Med. Phys. 37, 6347 (2010); doi:10.1118/1.3512806 (10 pages) " [+ leia mais]
Fonte: Mediacal Physics
Combining registration and active shape models for the automatic segmentation of the lymph node regions in head and neck CT images
"Purpose: Intensity-modulated radiation therapy (IMRT) is the state of the art technique for head and neck cancer treatment. It requires precise delineation of the target to be treated and structures to be spared, which is currently done manually. The process is a time-consuming task of which the delineation of lymph node regions is often the longest step. Atlas-based delineation has been proposed as an alternative, but, in the authors’ experience, this approach is not accurate enough for routine clinical use. Here, the authors improve atlas-based segmentation results obtained for level II–IV lymph node regions using an active shape model (ASM) approach. Methods: An average image volume was first created from a set of head and neck patient images with minimally enlarged nodes. The average image volume was then registered using affine, global, and local nonrigid transformations to the other volumes to establish a correspondence between surface points in the atlas and surface points in each of the other volumes. Once the correspondence was established, the ASMs were created for each node level. The models were then used to first constrain the results obtained with an atlas-based approach and then to iteratively refine the solution. Results: The method was evaluated through a leave-one-out experiment. The ASM- and atlas-based segmentations were compared to manual delineations via the Dice similarity coefficient (DSC) for volume overlap and the Euclidean distance between manual and automatic 3D surfaces. The mean DSC value obtained with the ASM-based approach is 10.7% higher than with the atlas-based approach; the mean and median surface errors were decreased by 13.6% and 12.0%, respectively. Conclusions: The ASM approach is effective in reducing segmentation errors in areas of low CT contrast where purely atlas-based methods are challenged. Statistical analysis shows that the improvements brought by this approach are significant. © 2010 American Association of Physicists in Medicine " [+ leia mais]
Fonte: Medical Physics
Optimal shielding design for bunkers of compact cyclotrons used in the production of medical radionuclides
"Med. Phys. 37, 6332 (2010); doi:10.1118/1.3515458 (6 pages) Purpose: There are several options to consider in the design of a vault that will house a cyclotron for radioisotopes production with regards to the door entrance. Alternatives are a direct-shielded door, a simple maze, or a double-legged maze. In this work, the impact of the neutron and photon doses at the vault entrance was evaluated for these options. Methods: Monte Carlo simulations were carried out in order to assess photon and neutron ambient dose equivalents. Simulations results were compared to experimental measurements taken inside a vault with a direct-shielded door. Results: The double-legged maze is the configuration that provides the higher degree of radiological protection at the vault entrance. In addition, the fact of the location of the cyclotron target plays an important role in the ambient dose equivalents. Conclusions: The comparison performed between measurements and results of MCNP simulations confirmed a favorable agreement; maze legs reduce the neutron energies at the entrances of the vault. However, a degree of dose reduction similar to the one obtained for a two-legged maze can be achieved with the addition of shielding against neutrons in the inner maze entrance to act as a second door. A choice of a vault design is more evident by comparing the results of this study. © 2010 American Association of Physicists in Medicine " [+ leia mais]
Fonte: Medical Physics
18th International Conference on Medical Physics (ICMP 2011)
"18th International Conference on Medical Physics (ICMP 2011). de 17 a 20 deabril de 2011, em Porto Alegre, no Centro de Eventos da PUCRS. A data limite para envio de resumos e artigos completos é 15 de janeiro de 2011,. Maiores informações sobre o evento podem ser encontradas em: http://www.pucrs.br/ficia/icmp2011 " [+ leia mais]
Colaborador: Ana Marques
Genome-Wide Association Study to Identify Single Nucleotide Polymorphisms (SNPs) Associated With the Development of Erectile Dysfunction in African-Am
"International Journal of Radiation Oncology*Biology*Physics Volume 78, Issue 5, 1 December 2010, Pages 1292-1300 Purpose To identify single nucleotide polymorphisms (SNPs) associated with erectile dysfunction (ED) among African-American prostate cancer patients treated with external beam radiation therapy. Methods and Materials A cohort of African-American prostate cancer patients treated with external beam radiation therapy was observed for the development of ED by use of the five-item Sexual Health Inventory for Men (SHIM) questionnaire. Final analysis included 27 cases (post-treatment SHIM score ≤7) and 52 control subjects (post-treatment SHIM score ≥16). A genome-wide association study was performed using approximately 909,000 SNPs genotyped on Affymetrix 6.0 arrays (Affymetrix, Santa Clara, CA). Results We identified SNP rs2268363, located in the follicle-stimulating hormone receptor (FSHR) gene, as significantly associated with ED after correcting for multiple comparisons (unadjusted p = 5.46 × 10−8, Bonferroni p = 0.028). We identified four additional SNPs that tended toward a significant association with an unadjusted p value < 10−6. Inference of population substructure showed that cases had a higher proportion of African ancestry than control subjects (77% vs. 60%, p = 0.005). A multivariate logistic regression model that incorporated estimated ancestry and four of the top-ranked SNPs was a more accurate classifier of ED than a model that included only clinical variables. Conclusions To our knowledge, this is the first genome-wide association study to identify SNPs associated with adverse effects resulting from radiotherapy. It is important to note that the SNP that proved to be significantly associated with ED is located within a gene whose encoded product plays a role in male gonad development and function. Another key finding of this project is that the four SNPs most strongly associated with ED were specific to persons of African ancestry and would therefore not have been identified had a cohort of European ancestry been screened. This study demonstrates the feasibility of a genome-wide approach to investigate genetic predisposition to radiation injury. " [+ leia mais]
Fonte: International Journal of Radiation Oncology*Biol
A comprehensive study of the Gafchromic EBT2 radiochromic film. A comparison with EBT
"Med. Phys. 37, 6271 (2010); doi:10.1118/1.3512792 (8 pages) Purpose: Radiochromic film has become an important tool to assess complex dose distributions. In particular, EBT was accepted by the scientific community as a reference two-dimensional detector. Recently, Gafchromic EBT2 has replaced old film, providing new improvements in both accuracy and handling. Methods: This work presents a dosimetric study of the new Gafchromic EBT2 using an Epson 10000XL flatbed scanner, also comparing the results with EBT film as reference when necessary. The most important film characteristics have been studied, such as ambient light sensitivity, different possibilities of the three RGB color channels, postirradiation development, high dose behavior, exposition at temperatures similar to the human body, and dependence on orientation during the scanning process. Results: The results obtained confirm a considerably lower sensitivity to ambient light of EBT2, as well as a fast stabilization of the film within 2 h. It has also been found that the green channel has a better behavior at high dose levels up to 35 Gy, in addition to good behavior of the red channel at doses below 10 Gy. Other features, such as temperature independence and scanning orientation dependence, have also been shown. Conclusions: Gafchromic EBT2 can be used for clinical practice in the same way as the old EBT film. However, a much easier handling as the result of all new enhancements improves film behavior, expanding in this way the potential applications of radiochromic film dosimetry. " [+ leia mais]
Med. Phys. 37, 6233 (2010); doi:10.1118/1.3514130 (7 pages)
"Purpose: Current on-board imaging systems commonly used by modern linear accelerators (LINACs) have a limited field of view (FOV) for a cone-beam CT (CBCT) scan, which is typically less than 50 cm. Consequently, truncation artifacts often occur for large patients. The goal of this work is to investigate a novel method to increase the FOV for current on-board CBCT systems. Methods: When a large patient is scanned with CBCT, any region outside the FOV is only partially sampled within a short range of projection angles, and at other angles no x-ray beams may pass through that region. To increase the sampling rate for the region outside the FOV, we have designed a new source trajectory by shifting the center of rotation during a CBCT scan. This resulted in a reduced sampling rate at the central area and increased sampling rate at the edges. The tradeoff led to a more balanced sampling for an enlarged FOV. An iterative algorithm was also developed to reconstruct the CT image under the new sampling scheme using a compressed sensing technique. Results: The method was validated by numerical simulations mimicking a Varian Trilogy CBCT system, and it was found that artifact-free images could be obtained with the FOV as large as 80 cm. Conclusions: The new CT scanning trajectory can be easily realized under current clinical setup with little modification of the control system, and this can be useful for treating obese patients. " [+ leia mais]
VII Curso de Física e Técnica e Aplicações da Tomografia
"Data: 26, 27 e 28 de Novembro de 2010 – Sexta, Sábado e Domingo. Local: Auditório do Instituto de Educação e Pesquisa do Hospital Moinhos de Vento Rua Ramiro Barcelos 910, 1° Subsolo – Porto Alegre – RS Carga-Horária: 25 horas-aula teóricas e 16 horas-aula práticas – Total: 41 horas Público-Alvo: Médicos, Residentes, Físicos, Tecnólogos e Técnicos em Radiologia, estudantes e demais profissionais da área de saúde. Objetivo: Este curso abordará os princípios físicos, técnicos e aplicações da tomografia computadorizada, desde seus parâmetros de aquisição de imagens até a anatomia radiológica seccional. Será explorado o funcionamento e principais diferenças entre os equipamentos convencionais, helicoidais e multislice. Serão realizadas atividades práticas junto ao equipamento multislice do Centro de Imagem. “O principal objetivo do curso é unir a física e técnica à prática clínica, apresentando aos participantes o embasamento teórico fundamental para o conhecimento da Tomografia Computadorizada”. Organização: Físicos Alessandro A. Mazzola, José Augusto Marconato e Éder Rezende de Quadros Incrições por e-mail: cursos.iep@hmv.org.br"
Colaborador: Cecília Haddad
Tracheobronchial amyloidosis: utilization of radiotherapy as a treatment modality.
"Tracheobronchial amyloidosis (TBA) is a rare disease. No general consensus exists with regard to its optimal treatment, resulting in a variety of modalities used to manage this condition. In this article, we present a case of TBA treated with external beam radiation therapy with encouraging results. A brief literature review of this rare ailment is also included. Other Sections▼ Abstract Introduction Case Report Discussion ReferencesIntroduction Primary amyloidosis involving the tracheobronchial tree is rare.[1,2] It represents a localized variant of amyloidosis and is characterized by multifocal amyloid deposition within the airway walls with subsequent formation of submucosal plaques or polypoid nodules. The clinical presentation of this disease is often nonspecific, with symptoms such as dyspnea, cough, hemoptysis, hoarseness, and stridor.[2] Pulmonary function tests typically reveal an obstructive pattern but may be normal when the disease is confined to the distal airways.[3] Chest x-rays are frequently unremarkable, often culminating in a delay of diagnosis. In most cases, the identification of this disease is made by means of bronchoscopy and biopsy of the airway mucosa.[4] Management of this disease often aims at maintaining patent airways. Localized treatment techniques such as bronchoscopic resection of disease and stenting have been described in current literature. However, these modalities often offer only a temporary solution as the disease usually recurs and progresses. The use of radiation therapy has been scarcely reported in the management of this rare condition. " [+ leia mais]
Fonte: Medscape J Med. 2008; 10(2): 42.
ANPG destaca importância da concessão de licença-maternidade a bolsistas
"10. ANPG destaca importância da concessão de licença-maternidade a bolsistas   A Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes) publicou na terça-feira (16/11) portaria que permite prorrogação da vigência da bolsa de parturientes Leia mensagem assinada pela presidente da ANPG, Elisangela Lizardo, e pela diretora de Comunicação da entidade, Luana Meneguelli Bonone:   ""A Associação Nacional de Pós-Graduandos (ANPG) tem pautado a humanização das bolsas de pesquisa, agregando neste conceito algumas pautas históricas, dentre as quais a licença-maternidade. A portaria n° 220, de 12 de novembro, publicada no Diário Oficial de terça-feira (16) pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes), que garante para parturientes a extensão por até quatro meses da bolsa, é uma justa resposta da Capes à reivindicação dos pós-graduandos, apresentada pela ANPG.   É estimulante ver o resultado concreto de uma luta tão cotidiana em termos de direitos para os pós-graduandos. Este é um passo importantíssimo que a Capes dá no sentido da humanização das bolsas, atendendo a demanda apresentada pela ANPG. O próximo passo é a valorização das bolsas, em maior número e com valor reajustado. Temos confiança que a Capes também será sensível a esta importante bandeira para o avanço da pós-graduação no país.   Só nesta gestão, foram diversas as ações desempenhadas pelos pós-graduandos brasileiros que pressionaram por esta conquista: no 22º Congresso Nacional de Pós-Graduandos, realizado no Rio de Janeiro em abril deste ano, foi aprovada resolução em favor da licença com extensão da bolsa.   Na semana da posse da atual diretoria, foi realizada ainda uma campanha de bolsas que teve duas pautas centrais: a campanha pela aprovação da licença-maternidade pela Capes, e a campanha pelo aumento do número e valor das bolsas da Capes e do CNPq.   Capes e MEC pautados   A reivindicação da licença-maternidade foi apresentada ao diretor de avaliação da Capes, Lívio Amaral, que recebeu a diretoria na ocasião. Na ocasião, a ANPG protocolou um documento endereçado ao presidente da Capes cobrando medidas emergenciais à pesquisa no Brasil, dentre as quais a licença-maternidade. Na mesma semana, a ANPG se reuniu com o Ministro Fernando Haddad e apresentou a pauta também neste espaço.   A pauta foi ainda reforçada na Caravana de Ciência, Tecnologia e Inovação da ANPG, realizada entre março e maio de 2010 em todas as regiões do país, e nos materiais das entidades, sempre aparecendo como bandeira urgente na luta pela humanização das bolsas.  E novamente pautada durante a participação da ANPG na 4ª Conferência Nacional de Ciência, Tecnologia e Inovação (CNCTI).   A pressão pela edição da portaria foi retomada quando da edição de outro documento, a portaria conjunta n° 001 da Capes e do CNPq, que permitiu acumulação de bolsas com trabalho remunerado. Por consequência do debate acerca desta última portaria, a ANPG lançou uma campanha pela humanização das bolsas, por meio de nota, novamente pautando como questões centrais a licença-maternidade e a bandeira por mais e melhores bolsas. " [+ leia mais]
Colaborador: Camila de Sales
Fonte: Jornal da ciência
Unesp terá instituto internacional de física teórica
"17. Unesp terá instituto internacional de física teórica   Nova unidade na Barra Funda é fruto de um acordo entre a universidade e o Centro Internacional de Física Teórica e deverá abrigar cinco especialistas Um acordo firmado entre o Instituto de Física Teórica (IFT), instalado no campus Barra Funda da Universidade Estadual Paulista (Unesp), e o Centro Internacional de Física Teórica (ICTP, na sigla em inglês) resultará em um novo instituto voltado à pesquisa básica e que receberá cinco especialistas.   O ICTP é um órgão da Organização das Nações Unidas para a Educação, a Ciência e a Cultura (Unesco) e sua sede fica na cidade de Trieste, na Itália, onde a parceria foi formalizada pelo diretor do ICTP, Fernando Quevedo, pelo vice-reitor da Unesp, Julio Cezar Durigan, e pelo diretor do IFT, Rogério Rosenfeld.   Denominada ICTP-South American Institute for Fundamental Research (Instituto Sul-Americano de Pesquisa Básica ICTP) a nova unidade terá infraestrutura provida pelo IFT e pesquisadores que realizarão estudos independentes e atuarão junto à pós-graduação da Unesp.   Segundo a universidade, a contratação dos profissionais será coordenada por um conselho científico formado por dez especialistas de projeção internacional, incluindo representantes regionais. Esse grupo orientará o trabalho do órgão. Os nomes dos seus integrantes serão definidos nos próximos meses.   ""O renome do ICTP ajudará a Unesp a atrair os melhores cérebros para o nosso quadro docente e também para as atividades acadêmicas e de pesquisa que vamos iniciar"", disse Rosenfeld.   A unidade também organizará workshops, seminários e palestras, viabilizando a participação de cientistas de prestígio do exterior. O diretor do IFT prevê que essas atividades tenham início já no segundo semestre de 2011.   A partir dessa ação, a Unesco pretende influenciar a criação de outros centros de excelência em pesquisa básica na área de física no continente americano, fora dos Estados Unidos e do Canadá.   Mais informações: www.unesp.br (Agência Fapesp, 19/11)     Anterior 16. Esquerda latino-americana vai com ambição para cúpula climática Próxima 18. Europeus flagram o 1º planeta de outra galáxia Índice de Noticías - imprimir - enviar - comentário " [+ leia mais]
Colaborador: Camila Sales
Fonte: Jornal da ciência
50 years of the SI – a key partner in science and technology
"As we celebrate the 50th anniversary of the International System of Units (SI), NPL|s Jonathan Williams explains just how essential the system is to science and society alike. NPL|s Jonathan Williams explains how important the SI units are to every aspect of our lives. Measurement today is incredibly valuable - we depend on it for almost everything. Healthcare relies upon measured dosages; food and raw materials are bought by weight or size; vehicle manufacturers need parts made in different countries to fit together - we could go on and on. Measurement is so embedded it often plays an essential but overlooked role. At the centre of it is the SI - the standard system of measurement units for scientists worldwide. The SI: from the laboratory to business The SI plays a large part in the work we do here, as NPL is the UK|s National Measurement Institute (NMI). As a NMI, we maintain and develop measurement standards, including those of the SI units. Our role also includes providing all the measurement infrastructure scientists, manufacturers and those in research and development need, working with them to ensure the accuracies required. A large part of this is calibrating measurement equipment against our standards, to find any errors and to keep measurements across the UK linked and traceable. As measurement touches on every aspect of our lives, the quality of it often matters greatly. Anyone who needs access to an SI unit can come to NPL. Of the SI base units - the second, the kilogram, etc. - some we do calibrations directly against. However, there are also the derived units, which are products and ratios of the base units. We package those units up and then give people calibrations of the derived units as well. For instance, force is measured in newtons, but made up of metres, kilograms and seconds; so we|d give calibrations in newtons. That|s another role of the NMI - to provide all the combinations that people want to use. Industries who need the highest quality of accuracy come directly to us for calibrations. Turning out products, day in and day out, they have to be sure everything is right all the time. NPL works directly with a diverse range of business sectors including aerospace, energy, environment, communications and healthcare. " [+ leia mais]
Colaborador: Laura Natal
Fonte: NPL
Fundamental Constants iPhone App
"NPL has released its first app, Fundamental Physical Constants, for iOS devices such as iPhones and iPads.It will provide researchers with easy and up-to-date access to the values for all the physical constants. " [+ leia mais]
Colaborador: Laura Natal
Fonte: Apple Store
IAEA Operational Safety Team Review Bohunice Nuclear Power Plant, Slovak Republic
"Bohunice, 18 November 2010 |An international team of nuclear installation safety experts, led by the International Atomic Energy Agency (IAEA), has reviewed Slovakia?s Bohunice Nuclear Power Plant (BNPP) for its safety practices and has noted a series of good practices as well as recommendations to reinforce them. The IAEA assembled an international team of experts at the request of the Government of Slovak Republic to conduct an Operational Safety Review (OSART) of Bohunice NPP. Under the leadership of the IAEA?s Division of Nuclear Installation Safety, the OSART team performed an in-depth operational safety review from 1 to 18 November 2010. The team was made up of experts from Belgium, Canada, China, the Czech Republic, France, Sweden, the United Kingdom, and the IAEA. An OSART mission is designed as a review of programmes and activities essential to operational safety. It is not a regulatory inspection, nor is it a design review or a substitute for an exhaustive assessment of the plant?s overall safety status. The team at BNPP conducted an in-depth review of the aspects essential to the safe operation of the NPP, which largely is under the control of the site management. The conclusions of the review are based on the IAEA?s Safety Standards and proven good international practices. The review covered the areas of Management, Organization and Administration; Operations; Maintenance; Technical Support; Operating Experience; Radiation Protection; Chemistry and Emergency Planning and Preparedness. Long Term Operation assessment has been requested by the plant in addition to the standard OSART program. The OSART team has identified good plant practices which will be shared with the rest of the nuclear industry for consideration of their application. Examples include: * BNPP has implemented a comprehensive set of technical and organizational measures which have significantly reduced the production of liquid radioactive waste; * BNPP has developed an automatic transfer of dosimetry data that enables both Bohunice and Mochovce sites to learn of workers doses in real time; and * a strong independent nuclear safety oversight organization has been set up at the utility level to support the plants in term of safety analysis and assessment. The team has made recommendations and suggestions related to areas where operational safety of Bohunice NPP could be improved. Examples include: * Work clearances orders and communication procedures are not always implemented in a safe manner; * identification and reporting of field deficiencies are not at the optimal level; and * contamination control practices could be further improved. BNPP management expressed a determination to address all the areas identified for improvement and requested the IAEA to schedule a follow-up mission in approximately 18 months. The team handed over a draft of their recommendations, suggestions and good practices to the plant management in the form of ""Technical Notes"" for factual comments. The technical notes will be reviewed at IAEA headquarters including any comments from BNPP and the Slovak Regulatory Authority. The final report will be submitted to the Government of Slovak Republic within three months. This was the 159th mission of the OSART programme, which began in 1982. " [+ leia mais]
Fonte: IAEA
Poder do vácuo
"Agência FAPESP – Seria a energia presente no vácuo capaz de controlar o destino de estrelas ou até mesmo do Universo inteiro? Uma nova linha de pesquisa conduzida por físicos brasileiros está mostrando que talvez isso seja possível. O assunto é o destaque da nova edição da revista Unesp Ciência, da Universidade Estadual Paulista. Os físicos descobriram na teoria um efeito capaz de transformar a energia do espaço vazio em protagonista de uma destruição “cataclísmica”, como definiu George Matsas, professor do Instituto de Física Teórica (IFT) da Unesp em São Paulo. O fenômeno é chamado de “despertar do vácuo”. Matsas coordena o Projeto Temático “Física em Espaços-Tempos Curvos”, apoiado pela FAPESP. A descoberta foi feita pelo professor Daniel Vanzella, do Instituto de Física de São Carlos da Universidade de São Paulo, e seu aluno William Couto Corrêa de Lima, que faz doutorado com Bolsa da FAPESP, e foi descrita em abril na revista Physical Review Letters. " [+ leia mais]
Fonte: Agência FAPESP
Exercícios podem reduzir risco de câncer
"Agência FAPESP – Mais uma boa notícia para quem pratica atividades físicas – ou um estímulo para quem quer começar. Um estudo observou que mulheres que se exercitaram por pelo menos 150 minutos por semana apresentaram risco reduzido de desenvolvimento de câncer de endométrio – tumor maligno mais comum nos órgãos genitais femininos. A pesquisa, feita na Escola Yale de Saúde Pública, nos Estados Unidos, foi apresentada nesta terça-feira (9/11) na Conferência de Pesquisa para Prevenção do Câncer da Associação Norte-Americana de Pesquisa sobre o Câncer, na Filadélfia. O menor risco foi verificado tanto para mulheres com peso normal como com sobrepeso ou obesas. “O estudo é consistente com trabalhos anteriores que fortemente apoiam a associação entre atividade física e menor incidência de câncer de endométrio”, disse Hannah Arem, um dos autores do estudo. " [+ leia mais]
Fonte: Agência FAPESP
Anti-hidrogênio é capturado 18/11/2010
"Agência FAPESP – Em um experimento feito no Centro Europeu de Pesquisas Nucleares (Cern), um grupo internacional de cientistas conseguiu demonstrar que é possível prender e controlar a liberação de átomos de anti-hidrogênio – equivalentes na antimatéria aos átomos de hidrogênio. A novidade, descrita nesta quinta-feira (18/11) no site da revista Nature, abre o caminho para a realização de estudos precisos sobre as simetrias fundamentais da natureza. A antimatéria é composta de antipartículas da mesma maneira que a matéria normal é formada por partículas. A antimatéria foi prevista pela primeira vez em 1931, pelo físico inglês Paul Dirac (1902-1984), como tendo a carga oposta da matéria normal e sendo aniquilada completamente em um flash de energia após interagir com a matéria normal. " [+ leia mais]
Colaborador: Laura Natal
Fonte: Agência FAPESP
Post-symposium Message from DDG-SG
"The Safeguards Symposium 2010 was a tremendous success. And I am personally delighted with the outcome. When we placed an international call for papers earlier this year, we never expected that we would be presenting around 220 of them at the Symposium. Participants originated from 70 Member States, as well as from 16 non-governmental organisations. We particularly want to continue to encourage developing countries to attend and contribute: the call for papers was to all States, and no submitted abstracts have been, or will be, rejected. " [+ leia mais]
Colaborador: Laura Natal
Fonte: IAEA
Páginas: 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49 - 50 - 51 - 52 - 53 - 54 - 55 - 56 - 57 - 58 - 59 - 60 - 61 - 62 - 63 - 64 - 65 - 66 - 67 - 68 - 69 - 70 - 71 - 72 - 73 - 74 - 75 - 76 - 77 - 78 - 79 - 80 - 81 - 82 - 83 - 84 - 85 - 86 - 87 - 88 - 89 - 90 - 91 - 92 - 93 - 94 - 95 - 96 - 97 - 98 - 99 - 100 - 101 - 102 - 103 - 104 - 105 - 106 - 107 - 108 - 109 - 110 - 111 - 112 - 113 - 114 - 115 - 116 - 117 - 118 - 119 - 120 - 121 - 122 - 123 - 124 - 125 - 126 - 127 - 128 - 129 - 130 - 131 - 132 - 133 - 134 - 135 - 136 - 137 - 138 - 139 - 140 - 141 - 142 - 143 - 144 - 145 - 146 - 147 - 148 - 149 - 150 - 151 - 152 - 153 - 154 - 155 - 156 - 157 - 158 - 159 - 160 - 161 - 162 - 163 - 164 - 165 - 166 - 167 - 168 - 169 - 170 - 171 - 172 - 173 - 174 - 175 - 176 - 177 - 178 - 179 - 180 - 181 - 182 - 183 - 184 - 185 - 186 - 187 - 188 - 189 - 190 - 191 - 192 - 193 - 194 - 195 - 196 - 197 - 198 - 199 - 200 - 201 - 202 - 203 - 204 - 205 - 206 - 207 - 208 - 209 - 210 - 211 - 212 - 213 - 214 - 215 - 216 - 217 - 218 - 219 - 220 - 221 - 222 - 223 - 224 - 225 - 226 - 227 - 228 - 229 - 230 - 231 - 232 - 233 - 234 - 235 - 236 - 237 - 238 - 239 - 240 - 241 - 242 - 243 - 244 - 245 - 246 - 247 - 248 - 249 - 250 - 251 - 252 - 253 - 254 - 255 - 256 - 257 - 258 - 259 - 260 - 261 - 262 - 263 - 264 - 265 - 266 - 267 - 268 - 269 - 270 - 271 - 272 - 273 - 274 - 275 - 276 - 277 - 278 - 279 - 280 - 281 - 282 - 283 - 284 - 285 - 286 - 287 - 288 - 289 - 290 - 291 - 292 - 293 - 294 - 295 - 296 - 297 - 298 - 299 - 300 - 301 - 302 - 303 - 304 - 305 - 306 - 307 - 308 - 309 - 310 - 311 - 312 - 313 - 314 - 315 - 316 - 317 - 318 - 319 - 320 - 321 - 322 - 323 - 324 - 325 - 326 - 327 - 328
Esqueceu sua senha?