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

Avaliação clínica da efetividade do clareamento de consultório sem troca do gel clareador

Esse trabalho teve como objetivo avaliar, clinicamente, a efetividade de dois agentes clareadores aplicados sobre a superfície dentária durante 45 minutos, sem troca do gel. Foram selecionados 10 pacientes de acordo com os critérios de inclusão e exclusão, e a arcada superior dos pacientes foi dividida em duas hemiarcadas (n = 10): na hemiarcada direita (HD), foi aplicado o peróxido de hidrogênio a 35% (PH) Clàriant Office (Angelus); e, na hemiarcada esquerda (HE), o PH 38% Opalescence Boost (Ultradent). Foram realizadas duas sessões clínicas, de 45 minutos cada, com intervalo de uma semana entre as sessões. Inicialmente, ao tratamento clareador, os pacientes receberam profilaxia, moldagem para guia de mensuração de cor com silicone de condensação e avaliação de cor por meio de um aparelho espectrofotômetro Vita Easyshade (Vita Zhanfabrik, Alemanha). Após 14 dias do término do tratamento clareador, foi realizada a mensuração final da cor dos dentes. Os dados foram submetidos ao teste t e de Tukey (p < 0,05). Os resultados demonstraram não haver diferença estatisticamente significativa entre as hemiarcadas quanto à efetividade do clareamento (p = 0,146) e nem quanto à sensibilidade. Pode-se concluir que a aplicação dos materiais avaliados sem troca do gel, por 45 minutos, foi eficaz em promover o clareamento de dentes vitais e com baixa sensibilidade dentária.

Emprego de carvão ativado e resinas de troca ionica na remoção de substâncias orgânicas contaminantes do alcool etílico

This work had with objective to characterize and evaluate the performance of the combined system, involving activated charcoal and ionic exchange resins in the removal of substances organic contaminating of the ethyl alcohol from the fermentation of the cassava starch. To testing was used ethyl alcohol PA 96 oGL, conductivity of 0.90 μS/cm at 25 oC, acidity of 60 mg/L and Barbet test of 43 minutes at 15 oC. The contaminated alcohol was composed of ethyl alcohol additive of higher alcohols, organic acids, ester, diol, aldehydes, ketone and ether. Contaminated alcohol was added 2% activated charcoal and after the adsorption isotherm in ionic exchange resins was tested. The adsorption with activated charcoal was performed in a Water Bath at 30 oC for one hour and a half and shaking. Already adsorption ionic exchange columns occurred at room temperature on columns of 93,4 cm in filling height and diameter of 2.29 cm, for flows of 180 mL/min and 90 mL/min. Samples were collected in the tests with charcoal and with each one of the resins and the following analyses were performed: conductivity, acidity and Barbet test. The medium values for conductivity, acidity and Barbet test after the adsorption in charcoal and cation and anion resins were respectively: conductivity was 240; 354 and 465 μS/cm to 25 oC; acidity of 1.081; 1.103 and 1.062 mg/L and the Barbet test was 21; 20 and 9 minutes to 15 oC. It was observed that the addition of 2% of activated charcoal and the permanence in the columns of adsorption was not sufficient to remove the organic substances contaminating of the ethyl alcohol.

Redução de tempos de setup: aplicação de troca rápida de ferramentas em indústria de bebidas

The current competitive market requires companies to adapt so that they can meet the needs of customers in an agile manner and aimed at the lowest possible cost in their manufacture, be it a product or service. The Toyota Production System is aimed at higher profits through lean manufacturing practices with reduced spending, smaller lots and inventories, generated by market demand. The variety of products makes the setup of the equipment a critical point and it should be reduced as much as possible so it does not affect productivity. The rapid exchange of tools allows with few actions and a modification that time does not exceed one digit on your total time. In this study, a case study showed that only with standardization and use of cheap improvements made it possible to reduce setup time in bottle labeling machine by 98 minutes for a final time of approximately 10 minutes with little investment, demonstrating the feasibility the displayed and a monthly gain tool in bottles at approximately 120,000, generating a performance gain and budget of approximately R$ 94,000.00 per month