Absorbed Dose
Mostrando 13-24 de 242 artigos, teses e dissertações.
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13. Electron-beam processed corn starch: evaluation of physicochemical and structural properties and technical-economic aspects of the processing
The properties of starch can be modified by a variety of methods in order to meet desirable technological needs. Electron beam irradiation is able to induce changes in starch properties. The paper deals with investigation of physicochemical and structural modifications of corn starch processed by electron beam up to 50 kGy and evaluation of the technical-eco
Braz. J. Chem. Eng.. Publicado em: 2013-12
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14. Avaliação da distribuição da dose absorvida em radioterapia com campos irregulares e alargados / Evaluation of absorbed dose distribution in radiotherapy with irregular and extended fields
Na elaboração do planejamento do tratamento de câncer com radiações ionizantes, o médico radioterapêuta, através dos protocolos clínicos, determina a dose de radiação diária para cada tipo específico de tumor e, junto com o físico, durante os procedimentos de simulação dos campos de tratamento, fazem a localização das áreas a serem tratada
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/04/2012
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15. Estudo da influência de partículas de ouro na dose absorvida em tecido mole utilizando dosimetria com gel polimérico / Study of the influence of gold particles on the absorbed dose in soft tissue using polymer gel dosimetry
The presence of high-Z material adjacent to soft tissue, when submitted to irradiation, enhances locally the absorbed dose in these soft tissues. Such effect occurs due to the outscattering of photoelectrons from the high-Z material. Polymer gel dosimeters have been used to investigate this effect. Analytic calculations to estimate the dose enhancement and M
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/10/2011
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16. Elaboração e implementação de um programa para aplicação do método de Clarkson em radioterapia / Elaboration and implementation of one program for application of the method of Clarkson in radiotherapy
Radiotherapy has a fundamental part that is the patient treatment planning. For its success, the medical physicist has to use physical parameters based on the radiation interaction with the matter, in this case the patient; in order to determine the radiation absorbed dose in the selected target volume. The physical parameters normally are related to regular
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/03/2011
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17. Evaluation of hela cell lineage response to β radiation from Holmium-166 embedded in ceramic seeds
This work studied the effects of β radiation of Ho-166 embedded in ceramic seeds on HeLa cells. Methodology consisted in the production of ceramic seeds with holmium-165 by sol-gel route. Chemical and physical characterizations of the seeds were performed. Subsequently, nuclear characterization was performed by gamma spectrometry. Experimental and theoretic
Brazilian Archives of Biology and Technology. Publicado em: 2011-10
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18. Investigation the natural radioactivity in local and imported chemical fertilizers
In order to assess the radioactive level in the environment, the specific activities of 238U, 232Th and 40K were measured by using a gamma ray spectrometer based on a NaI(Tl) detector. The results showed that the specific activities of 238U, 232Th and 40K were 12.846-88.585, 1.304-26.656 and 11.598-2275.896 Bq/kg respectively. The radium equivalent activity
Brazilian Archives of Biology and Technology. Publicado em: 2011-08
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19. Retrieval of GammaCell 220 irradiator isodose curves with MCNP simulations and experimental measurements
Gamma irradiator facilities can be used in a wide range of applications such as biological and chemical researches, sterilization of medical devices and products. Dose mapping must be performed in these equipments in order to establish plant operational parameters, as dose uniformity, source utilization efficiency and maximum and minimum dose positions. The
Brazilian Journal of Physics. Publicado em: 2010-03
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20. Bioaccumulation and chemical forms of cadmium, copper and lead in aquatic plants
The cadmium(Cd), copper(Cu) and lead(Pb) accumulation, as well as their relative content of different chemical forms in Sagittaria sagittifolia L. and Potamogeton crispus L. were determined. The results showed that both the plants had the ability to accumulate large amounts of Cd, Cu and Pb, and they absorbed metals in dose-dependent manners. The roots of S.
Brazilian Archives of Biology and Technology. Publicado em: 2010-02
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21. Activity of natural radionuclides and their contribution to the absorbed dose in the fish cubera snapper (lutjanus cyanopterus, cuvier, 1828) on the coast of Ceara, Brazil
Visando a radioproteção ambiental, baseada no conceito de limite de taxa de dose absorvida, foi desenvolvida uma metodologia de conversão da concentração de atividade de radionuclídeos (Bq kg-1) em taxa de dose absorvida (Gy a-1). O modelo considera apenas a taxa de dose absorvida interna. Essa metodologia foi aplicada ao peixe vermelho-caranho (Lutjan
Brazilian Journal of Oceanography. Publicado em: 2010
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22. Distribuição da dose absorvida no tratamento da micose fungóide através da dosimetria Fricke Xilenol Gel / Absorbed dose distribution in the treatment of Mycosis Fungoides using Fricke Xylenol Gel dosimetry
A radioterapia utiliza a radiação ionizante para a destruição de células tumorais. O controle da dose absorvida de um tipo específico de radiação aplicada a um volume alvo (tumor) é feito através da dosimetria, (uso de sensores de radiação), que neste trabalho foram utilizados os dosímetros químicos Fricke e filme. Dentre os diversos tipos de c
Publicado em: 2010
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23. VARIABLE-RATE NITROGEN FERTILIZATION WITH N-SENSOR IN MAIZE AND WHEAT / ADUBAÇÃO NITROGENADA À TAXA VARIADA COM O N-SENSOR NAS CULTURAS DO MILHO E TRIGO
Most tropical and subtropical soils present insufficient availability of nitrogen (N) to meet the demand of maize and wheat in order to obtain high yields. The N in plants can be evaluated through the use of sensors of active optical spectrometry, on which stands the N-Sensor, equipment able to determine the N rate to be applied in coverage in real-time. The
Publicado em: 2010
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24. 6 MV wedge photon beam profiles with the fricke xylenol gel dosimeter
Wedged beam are often used in clinical radiotherapy to compensate missing tissues and dose gradients. In this work, the Fricke Xylenol Gel (FXG) dosimeter was used for 6 MV photons radiation wedge field profiles measurements, allowing to infer the wedge filter physical attenuation coefficient. This dosimeter is a chemical system of a Fe3+-Xylenol complex con
Brazilian Journal of Physics. Publicado em: 2009-12