X Ray Dosimetry
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Recovery of α-Al2O3 from Ionizing Radiation Dosimetric Sensors
Corundum, sapphire or α-Al2O3 is an important technological material in many optical and electronic applications such as solid-state lasers, optical windows and, more recently, as a radiation detector. Landauer (Glenwood, IL, USA) accumulated large number of archived and stored Luxel™ dosemeters composed of Al2O3:C, which were subjected to a recovery proc
Mat. Res.. Publicado em: 2015-02
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2. Análise dos procedimentos e critérios de implantação de feixes de raios X de referência ISO 4037 em baixas energias
According to the radiological protection principles, practices involving ionizing radiation must be planned and carried out under the guarantee that the values of individual doses, the number of people exposed to radiation and the probability of accidental exposures are as low as reasonably achievable. Therefore, radiation dosimetry is required to be done wi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/08/2012
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3. CARACTERIZAÇÃO DE DISPOSITIVOS ELETRÔNICOS PARA DOSIMETRIA EM TOMOGRAFIA COMPUTADORIZADA. / CHARACTERIZATION OF ELECTRONIC DEVICES FOR DOSIMETRY IN COMPUTED TOMOGRAPHY.
Computed tomography (CT) is an examination of high diagnostic capability that delivers high doses of radiation compared with other diagnostic radiological examinations. The current CT dosimetry is mainly made by using a 100 mm long ionization chamber. However, it was verified that this extension, which is intended to collect all scattered radiation of the si
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/03/2012
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4. Manufacturing polycrystalline pellets of natural quartz for applications in thermoluminescence dosimetry
This paper describes the manufacturing process of quartz-pellets and shows their potential use as thermoluminescence dosimeters (TLD) for those applications where low-levels of ionising radiation are present. Two batches of cold-pressed pellets were produced and their resistance were evaluated by vibration tests and weight-loss measurements. The batch manufa
Materials Research. Publicado em: 10/07/2012
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5. Dose rate influence on deep dose deposition using a 6 MV x-ray beam from a linear accelerator
Linear accelerators used in radiation therapy treatments usually provide the capability of irradiating with different dose rates. The medical physicist may choose arbitrary the dose rate to use, although the relative biological effectiveness (RBE) varies with this physical parameter. In this work the measurements of absorbed dose of the x-ray beams from a Va
Brazilian Journal of Physics. Publicado em: 2009-06
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6. Development of a calibration methodology for instruments used to interventional radiology quality control / Desenvolvimento de uma metodologia para a calibração de instrumentos de medida utilizados no controle da qualidade em radiodiagnóstico intervencional
Interventional radiology is the technique where X radiation images are used as a tool in the conduction of diagnostic or/and therapeutic procedures. The exposition times are long for both procedures, diagnostic and therapeutic, may cause serious injuries in the patient, and also contribute to the dose of the clinical staff. In Brazil there are not yet well e
Publicado em: 2009
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7. Low dose computed tomography for dental implants : dosimetry and image quality / Tomografia computadorizada de baixa dose para implantes : dosimetria e qualidade de imagem
Computed Tomography (CT) is frequently used for planning implants. But, it is a consensus that its use deals with a high amount of X radiation, what limits its reference to complex cases. With the advent of multislice CT (MSCT), it s possible to acquire exams in minimal time, with isometric voxel images that allow high quality multiplanar reconstructions. Ho
Publicado em: 2009
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8. Luminescence dosimeter based on magnesium doped aluminum oxide: production and characterization. / Confecção e caracterização de dosímetro luminescente de óxido de alumínio dopado com magnésio.
The aim of the present work is to obtain and characterize luminescent dosimeters made of magnesium doped aluminium oxide, for ionizing radiation dosimetry purposes. The material is produced by Pechini Method (US Patent 3.330.697, 1967), starting from a polymer that generates powder ceramic, after firing at predetermined temperatures. Dosimetric measurements
Publicado em: 2008
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9. Desenvolvimento de uma interface grÃfica de usuÃrio para modelos computacionais de exposiÃÃo externa / DEVELOPMENT OF A GRAPHIC USER INTERFACE FOR EXTERNAL EXPOSURE COMPUTATIONAL MODELS
To evaluate the absorbed dose by the patient, in a series of exams, it is necessary to accomplish simulations using an exposure computational model. Such models are fundamentally composed of a virtual representation of the human body (phantom) and a Monte Carlo code. There are several Monte Carlo codes available and also specific voxel phantoms for the two g
Publicado em: 2007
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10. Caracterização e dosimetria de feixes de raios-x de 100 e 140kVp usados em radioterapia
Radiotherapy is the modality used in the treatment of malignant neoplasias that aims the deposition of a controlled amount of ionizing radiation in a limited area of the patient body. In order to provide a well-known and as accurate as possible absorbed dose for controlling a lesion, all characteristics of the treatment radiation beam must be known. For this
Publicado em: 2006
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11. UtilizaÃÃo do dosÃmetro Fricke para dosimetria de mÃquinas teleterapÃuticas, irradiadores gammacel e aparelhos de raios-X superficiais
The chemical dosimetry has been used as a reference in the measurement of the absorbed dose, with the Fricke dosimeter, at standardization laboratories. This dosimeter is considered an absolute dosimetric standard for measurements of radiation doses ranging from 20 to 400 Gy, covering a wide energy spectrum, from X-ray, g-ray to fast electron beam. The objec
Publicado em: 2006
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12. Desenvolvimento de um equipamento para dosimetria por luminescÃncia oticamente estimulada (LOE)
In recent years the Optically Stimulated Luminescence (OSL) has become a popular procedure for the dosimetry of the ionizing radiation. OSL arises from the recombination of charges which has been optically released from electron traps within the crystal. The electron population in the traps is the result of irradiation of the material, and thus the OSL inten
Publicado em: 2006