Viabilidade do Código MCNPX para o Estudo da Técnica de Fluorescência de Raios-X por Reflexão Total

The X-ray fluorescence analysis (XRF) is an important technique for the qualitative and quantitative determination of chemical components in a sample. It is based on measurement of the intensity of the emitted characteristic radiation by the elements of the sample, after being properly excited. One of the modalities of this technique is the total reflection x-ray fluorescence (TXRF). In TXRF, the angle of refraction of the incident beam tends to zero and the refracted beam is tangent to the sample-support interface. Thus, there is a minimum angle of incidence that there is no refracted beam and all the incident radiation undergoes total reflection. As it is implemented in very small samples, in a film format, self-absorption effects should not very relevant. In this study, we evaluated the feasibility of using code MCNPX (Monte Carlo N - Particle eXtended), to simulate a measure implemented by the TXRF technique. In this way, it was verified the quality of response of a system by TXRF spectroscopy using synchrotron radiation as excitation beam for a simple setup, by retrieving the characteristic energies and the concentrations of the elements in the sample. The steps of data processing, after obtaining the excitation spectra, were the same as in a real experiment and included the obtaining of the sensitivity curve for the simulated system. The agreement between the theoretical and simulated values of Ka characteristic energies for different elements was lower than 1 % .The obtained concentration of the elements of the sample had high relatively errors ( between 6 and 60 % ) due mainly to lack of knowing about some realistic physical parameters of the sample , such as density . In this way, this result does not preclude the use of MCNPX code for this type of application

Análise dos precedentes judiciais a partir do projeto de novo Código de Processo Civil Brasileiro

Pós-graduação em Direito - FCHS

Análise dosimétrica de perfis de distribuições radiais de doses relativas de um aplicador de betaterapia de 90Sr+90Y utilizando o código MCNP-4C e filmes raiocrômicos

Although they are no longer manufactured, the applicators of 90Sr +90Y acquired in the decades of 1990 are still in use, by having half-life of 28.5 years. These applicators have calibration certificate given by their manufacturers, where few have been recalibrated. Thus it becomes necessary to accomplish thorough dosimetry of these applicators. This paper presents a dosimetric analysis distribution radial dose profiles for emitted by an 90Sr+90Y betatherapy applicator, using the MCNP-4C code to simulate the distribution radial dose profiles and radiochromium films to get them experimentally . The results with the simulated values were compared with the results of experimental measurements, where both curves show similar behavior, which may validate the use of MCNP-4C and radiochromium films for this type of dosimetry

Evolução da área florestada na região de Botucatu/SP no período de 1996 a 2008 visando à implantação da Reserva Legal

Due to the considerations on the Legal Forest Reserve, the aim of this paper is to show the distribution of the farming areas in the region and their application – especially natural forests. Also, to compare the municipal values with those stated in the Brazilian Forest Code in order to analyze the process of implementing 20% of forest area in relation to the total farming area, at municipal and regional levels, not considering the areas of each of the farms nor the watershed to which they belong with the Brazilian Forestry Code. The work results show that all municipalities in the region of Botucatu do not have forest areas equal or greater than 20% of total area. Therefore, a non-exploratory reforestation procedure will have to be implemented to follow legal requirements. Finally, the results show that the city of Areiópolis will face the greatest difficulties in implementing the 20% of forests with regard to the Legal Forest Reserve, until 2021, when the deadline stated by the Legal Code expires. According to the same variables, the municipalities of Anhembi, Conchas, Laranjal Paulista, Pereiras, Pratânia and São Manuel will face medium-level difficulties, whereas Bofete, Botucatu, Itatinga and Pardinho will implement it the easiest way.

O problema de porte de estoque numa indústria moveleira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)