Influência dos parâmetros de preparação de amostras na análise química elementar de minerais por fluorescência de raios X

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Ciência e Engenharia de MateriaisO presente estudo revela a otimização das variáveis de preparação de amostras para análise química de minerais por espectrometria de fluorescência de raios x. São definidos, por experimentações e avaliações estatísticas, os níveis ótimos de trabalho com os parâmetros principais deste processo: tamanho de partículas, pressão de compactação e percentual de adição de aglutinantes. Verifica-se também, outros problemas paralelos do assunto: oscilação de equipamentos, limites de detecção e contaminações dos materiais e acessórios. O embasamento em estudos anteriores na área, permitiu o direcionamento objetivo dos ensaios. É demonstrado por meio de gráficos, a quantificação da influência específica em cada elemento analisado, para os determinados materiais escolhidos: quartzo, feldspato potássico e calcário dolomítico

Sustainability in pelletizing iron ore through the Industrial Ecology and Cleaner Production Program

This study aims to analyze the practices of a pelletizing iron ore industry with respect to adoption of pollution prevention measures, suggested by applying the concepts of Cleaner Production and Material Flow Analysis. The technical procedure adopted was the case study, the data collection was done through direct observation, with field research and literature review. The main results were obtained from analysis of company reports available to the public, but require a more detailed quantification of data. The study concludes that the identification of environmental opportunities is possible through the proposed implementation of Cleaner Production program, which provides better results when combined with the precepts of the industrial ecology tool, the Material Flow Analysis

An alternative approach to aminodiols from Baylis-Hillman adducts: stereoselective synthesis of chloramphenicol, fluoramphenicol and thiamphenicol

We describe herein a new approach for the stereoselective synthesis of broad spectrum antibiotics from Baylis-Hillman adducts. The strategy is based on the preparation of an ene-carbamate directly from a Baylis-Hillman adduct using a Curtius rearrangement reaction. Stereoselective hydroboration furnished a mixture of diastereoisomeric aminoalcohols (syn and anti). After chromatographic separation, the syn diastereoisomer was directly transformed into the antibiotics.Descrevemos aqui uma nova interpretação para a espectros de banda larga da síntese estereosseletiva de antibióticos de adutos Baylis-Hillman. A estrategia é baseada na preparação de um eno-carbamato diretamente do aduto Baylis-Hillman, usando um rearranjo de Curtius. A hidroboração estereosseletiva fornece uma mistura de aminoalcools diasteroisomeros (syn e anti). Após separação cromatográfica, o diasteroisomero syn foi diretamente transformado no antibiótico.386396Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Magnitude, delay and probability of reinforcer in hypothetical risk situations

O presente trabalho investigou os efeitos de quantias de dinheiro descritas como a alternativa de risco e da instrução sobre o valor subjetivo do reforço. Oito estudantes realizaram escolhas hipotéticas entre quantias de dinheiro certas ou imediatas que eram ajustadas de acordo com o comportamento dos sujeitos, e cinco quantias de magnitudes maiores (V = R$10,00 a R$100.000,00) atrasadas (uma semana a 50 anos) ou probabilísticas (0,05 a 0,95). A instrução positiva descrevia as chances ou o atraso para receber cada quantia, enquanto a instrução negativa descrevia as chances de perder ou o tempo de espera para não perder as quantias. O valor subjetivo diminuiu com o aumento de V provável, e aumentou com o aumento de V atrasado. Os resultados individuais foram melhor descritos por uma função potência do que pela hiperbólica. A variação da instrução não produziu diferenças sistemáticas. Os resultados são evidências para uma interpretação diferente do efeito da magnitude do reforço sobre o desconto de quantias prováveis ou atrasadas.The present study investigated the effects of reinforcement magnitude of the risk alternative and different instructions on the subjective reinforcement value. Eight undergraduate students made hypothetical choices between certain immediate amounts of money that were adjusted according to the subjects' behavior, and larger amounts (V = R$10,00 to R$100.000,00) with several delays (one week to 50 years) or probabilities (0,05 to 0,95) associated to V. The positive instruction described the odds or waiting time to gain each amount of money, while the negative instruction described the odds against or the waiting time for not loosing the money. The relative subjective value decreased with increase in the probable V, and increased with increase in the delayed V. Individual results were better described by a power function than by an hyperbola. There was no systematic effect related to different instructions. The present results are evidences for a different interpretation about the effects of the reinforcement magnitude on the discount of probable or delayed amounts

Formation of authentic personality and the corporeity in the light of Edith Stein

Considerando que o tema da autenticidade tem se tornado um importante referencial ético da sociedade contemporânea, discutimos neste trabalho as contribuições de Edith Stein para a compreensão do processo de formação da personalidade autêntica, com especial atenção à maneira como a corporeidade participa dessa dinâmica. Trata-se de uma pesquisa bibliográfica, em que examinamos alguns textos steinianos que abordam diretamente o tema da estrutura da pessoa e seu processo formativo, especialmente O problema da empatia, Sobre a ideia de formação e Potência e ato, respectivamente com originais dos anos de 1917, 1930 e 1931. Discutido como processo de formação da personalidade e como princípio de individuação, Stein acentua a necessidade de considerarmos a pessoa em ato, como meio de conhecermos sua autêntica individualidade, mesmo havendo limites para esse conhecimento.Considering that the theme of authenticity has become an important ethical framework for contemporary society, this study discusses the contributions of Edith Stein to understand the process of authentic personality formation, with special attention to the way that corporeality participates in this dynamic. This is a bibliographical research, in which some texts from Stein are examined, which directly address the theme of structure of people and their formative process, especially, The problem of empathy, Concerning the idea of formation and Potency and act, with originals from the years 1917, 1930 and 1931, respectively. Discussed as a process of personality formation and as a principle of individuation, Stein emphasizes the need to consider the person in act, in order to know their authentic individuality, even though there are limits to this knowledge

Non-Gaussian structural time series models.

This thesis aims to develop a class of state space models for non-Gaussian time series. Our models are based on distributions of the exponential family, such as the Poisson, the negative-binomial, the binomial and the gamma. In these distributions the mean is allowed to change over time through a mechanism which mimics a random walk. By adopting a closed sampling analysis we are able to derive finite dimensional filters, similar to the Kalman filter. These are then used to construct the likelihood function and to make forecasts of future observations. In fact for all the specifications here considered we have been able to show that the predictions give rise to schemes based on an exponentially weighted moving average (EWMA). The models may be extended to include explanatory variables via the kind of link functions that appear in GLIM models. This enables nonstochastic slope and seasonal components to be included. The Poisson, negative binomial and bivariate Poisson models are illustrated by considering applications to real data. Monte Carlo experiments are also conducted in order to investigate properties of maximum likelihood estimators and power studies of a post sample predictive test developed for the Poisson model

Absence of Wharton’s jelly: case report

There are few reports in the literature of the absence of Wharton's Jelly. Here we report the seventh case in a primigravida, 22 years old, admitted after vaginal delivery of stillborn. The umbilical cord have a long segment with disruption of cord structures and the three blood vessels were completely separated from each other, with a minimum amount of Wharton's jelly remaining around each vessel. The absence of Wharton' jelly is associated with fetal distress, intrauterine growth restriction, and fetal death. Quantitative/qualitative studies of Wharton's jelly represent an open field of research for possible correlations with obstetric conditions and fetal deaths

Sustainability in pelletizing iron ore through the Industrial Ecology and Cleaner Production Program

<p>This study aims to analyze the practices of a pelletizing iron ore industry with respect to adoption of pollution prevention measures, suggested by applying the concepts of Cleaner Production and Material Flow Analysis. The technical procedure adopted was the case study, the data collection was done through direct observation, with field research and literature review. The main results were obtained from analysis of company reports available to the public, but require a more detailed quantification of data. The study concludes that the identification of environmental opportunities is possible through the proposed implementation of Cleaner Production program, which provides better results when combined with the precepts of the industrial ecology tool, the Material Flow Analysis.</p