Tratamento de materiais contaminados com bifenilas policloradas (PCBS) via extração convencional e fluído supercrítico

The decontamination of the materials has been subject of some studies. One of the factors that it increases the pollution is the lack of responsibility in the discarding of toxic trash, as for example the presence of PCB (Polychlorinated Biphenyls) in the environment. In the Brazilian regulations, the material contaminated with PCB in concentrations higher than 50 ppm must be stored in special places or destroyed, usually by incineration in plasma furnace with dual steps. Due to high cost of the procedure, new methodologies of PCBs removal has been studied. The objective of this study was to develop an experimental methodology and analytical methodology for quantification of removal of PCBs through out the processes of extractions using supercritical fluid and Soxhlet method, also technical efficiency of the two processes of extraction, in the treatment of contaminated materials with PCBs. The materials studied were soils and wood, both were simulated contamination with concentration of 6.000, 33.000 and 60.000 mg of PCB/ kg of materials. Soxhlet extractions were performed using 100 ml of hexane, and temperature of 180 ºC. Extractions by fluid supercritical were performed at conditions of 200 bar, 70°C, and supercritical CO2 flow-rate of 3 g/min for 1-3 hours. The extracts obtained were quantified using Gas chromatography-mass spectrometry (GC/MS). The conventional extractions were made according to factorial experimental planning technique 22, with aim of study the influence of two variables of process extraction for the Soxhlet method: contaminant concentration and extraction time for obtain a maximum removal of PCB in the materials. The extractions for Soxhlet method were efficient for extraction of PCBs in soil and wood in both solvent studied (hexane and ethanol). In the experimental extraction in soils, the better efficient of removal of PCBs using ethanol as solvent was 81.3% than 95% for the extraction using hexane as solvent, for equal time of extraction. The results of the extraction with wood showed statistically it that there is not difference between the extractions in both solvent studied. The supercritical fluid extraction in the conditions studied showed better efficiency in the extraction of PCBs in the wood matrix than in soil, for two hours extractions the obtain percentual of 43.9 ± 0.5 % for the total of PCBs extracted in the soils against 95.1 ± 0,5% for the total of PCBs extracted in the wood. The results demonstrated that the extractions were satisfactory for both technical studied

Síntese e caracterização de tungstatos de cério e estrôncio para fins catalíticos

The main goal of this work was to produce nanosized ceramic materials of the family of the tungstates (tungstates of cerium and strontium), and test them for their catalytic activity in processes involving the transformation of methane (CH4). The methodology used for the synthesis of the ceramic powders involved the complexation combining EDTA-citrate. The materials characterization was performed using simple and differential thermogravimetry, x-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy (EDS). The microstructure analysis was performed using the refinement by the Rietveld method, and the crystallite size and distribution of the materials was elucidate by the Scherrer and Williamson-Hall methods. The conditions of the synthesis process for the three envisaged materials (SrWO4, SrWO4 using tungsten oxide concentrate as raw material, and Ce2(WO4)3) were adjusted to obtain a single phase crystalline material. The catalytic tests were carried out in the presence of methane and synthetic air, which is composed of 21% O2 and 79% N2. The analysis of the conversion of the reaction was done with the aid of an fourier transform infrared device (FTIR). The analysis showed that, structurally, the SrWO4 produced using raw materials of high and poor purity (99% and 92%, respectively) are similar. The ideal parameters of calcination, in the tested range, are temperature of 1000 °C and time of calcination 5 hours. For the Ce2(WO4)3, the ideal calcination time and are temperature 15 hours and 1000°C, respectively. The Williamson-Hall method provided two different distributions for the crystallite size of each material, whose values ranged between the nanometer and micrometer scales. According to method of Scherrer, all materials produced were composed of nanometric crystallites. The analyses of transmission electron microscopy confirmed the results obtained from the Williamson- Hall method for the crystallite size. The EDS showed an atomic composition for the metals in the SrWO4 that was different of the theoretical composition. With respect to the catalytic tests, all materials were found to be catalytically active, but the reaction process should be further studied and optimized.

Formação de particulas submicrometricas de pmma por cristalização termica de solução polimérica

Polymer particles in the nanometer range are of fundamental interest today, especially when used as carrier systems in the controlled release of drugs, cosmetics and nutraceuticals, as well as in coating materials with magnetic properties. The main objective of the present study concerns the production of submicron particles of poly (methyl methacrylate) (PMMA) by crystallization of a polymer solution by thermally controlled cooling. In this work, PMMA solutions in ethanol and 1-propanol were prepared at different concentrations (1% to 5% by weight) and crystallized at different cooling rates (0.2 to 0.8 ° C / min) controlled linearly. Analysis of particle size distribution (DLS / CILAS) and scanning electron microscopy (SEM) were performed in order to evaluate the morphological characteristics of the produced particles. The results demonstrated that it is possible to obtain submicron polymer perfectly spherical particles using the technique discussed in this study. It was also observed that, depending on the cooling rate and the concentration of the polymer solution, it is possible to achieve high yield in the formation of submicron particles. In addition, preliminary tests were performed in order to verify the ability of this technique to form particulated carrier material with magnetic properties. The results showed that the developed technique can be an interesting alternative to obtain polymer particles with magnetic properties

Exercício resistido no cardiopata: revisão sistemática

INTRODUÇÃO: A perda de massa muscular secundária à idade e à inatividade física é clinicamente relevante na população cardíaca; contudo, a prescrição do exercício resistido dinâmico para esses pacientes apresenta-se inconclusiva na literatura. OBJETIVOS: Reunir informações e apresentar as principais diretrizes relacionadas à prescrição de exercícios resistidos em cardiopatas. MATERIAIS E MÉTODOS: Foi realizada busca sistemática de literatura, a partir das bases de dados LILACS, SciELO e MEDLINE, utilizando os seguintes descritores na língua portuguesa: força muscular, exercício isométrico, esforço físico, cardiopatia e coronariopatia, e seus correspondentes na língua inglesa (muscle strength, isometric exercise, physical effort, heart disease e artery coronary disease), os quais foram pesquisados separadamente e em cruzamentos, sendo considerados para esta revisão apenas artigos publicados entre 2005 e 2010. RESULTADOS E DISCUSSÃO: de um total de 806 artigos foram selecionados 22 para integrar a revisão, sendo 14 estudos classificados como artigos originais, 2 artigos de atualização da literatura e 6 artigos de revisão, além do capítulo 8 do livro intitulado Diretrizes do ACSM (American College of Sports Medicine) para os testes de esforço e sua prescrição, publicado em 2007. CONCLUSÃO: O exercício resistido, independente da variada metodologia utilizada na prescrição dos componentes específicos do treinamento, mostrou-se eficiente para aumentar a força muscular de membros superiores e inferiores em cardiopatas e sua aplicação pode ser considerada segura para esses pacientes, desde que prescrito corretamente.

Cigarette smoke exposure severely reduces peripheral insulin sensitivity without changing GLUT4 expression in oxidative muscle of Wistar rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise da aceitação de aguardentes de cana por testes afetivos e mapa de preferência interno

A aceitação de 11 amostras de aguardentes de cana envelhecidas e não envelhecidas foi avaliada por testes sensoriais afetivos e análises estatísticas uni e multivariada. As aguardentes estudadas compreenderam seis amostras comerciais de diferentes marcas, (sendo três não envelhecidas e três envelhecidas) e ainda outras cinco amostras correspondentes a zero, 12, 24, 36 e 48 meses de envelhecimento em um tonel de carvalho de 200L. As amostras foram avaliadas por 100 provadores consumidores do produto, recrutados por questionário de avaliação quanto à afetividade. Para os testes afetivos foi utilizada escala hedônica não estruturada de 9cm, sendo os dados obtidos avaliados por dois métodos estatísticos distintos: o Mapa de Preferência Interno (MDPREF) e a análise de variância univariada (ANOVA) com comparação de médias pelo teste de Tukey e análise de correlação. As amostras de aguardente envelhecidas por 12, 36 e 48 meses obtiveram maior aceitação, com médias ao redor de 7,0 na escala hedônica. A amostra com menor aceitação foi a correspondente ao tempo zero de envelhecimento (controle). As demais amostras obtiveram aceitação intermediária. A análise por MDPREF gerou em espaço multidimensional (onde as variações com relação aos dados de preferência foram extraídas em eixos ortogonais e para cada dimensão de preferência), coordenadas relativas aos produtos, que foram geradas em função da resposta dos consumidores. Os dados de aceitação de cada provador foram utilizados para o desenvolvimento de vetores individuais de preferência, resultando na construção de um mapa mutidimensional das amostras, em função dos dados de aceitação. No presente estudo o MDPREF foi gerado pelas primeira e segunda dimensões de preferência, as quais explicaram em conjunto 89,83% das variações observadas entre as amostras com relação à aceitação. O MDPREF confirmou os resultados da ANOVA, indicando uma maior preferência dos provadores pelas amostras de aguardentes envelhecidas. Os resultados sugerem também que aguardentes envelhecidas por mais de 24 meses em tonel de carvalho de 200L são preferidas pelos consumidores, em detrimento das comerciais não envelhecidas e mesmo das comerciais envelhecidas, que podem ser adicionadas de aguardente não envelhecida (processo denominado corte) e também ter correção da cor, conforme permite a Legislação Brasileira. O conteúdo de polifenóis totais e a intensidade de cor também foram determinados, e ambos apresentaram correlação linear positiva significativa (p<=0,05) com o aumento do tempo de envelhecimento das amostras.

Acelaração do universo e criação gravitacional de matéria escura fria: novos modelos e testes observacionais

Recent astronomical observations (involving supernovae type Ia, cosmic background radiation anisotropy and galaxy clusters probes) have provided strong evidence that the observed universe is described by an accelerating, flat model whose space-time properties can be represented by the FriedmannRobertsonWalker (FRW) metric. However, the nature of the substance or mechanism behind the current cosmic acceleration remains unknown and its determination constitutes a challenging problem for modern cosmology. In the general relativistic description, an accelerat ing regime is usually obtained by assuming the existence of an exotic energy component endowed with negative pressure, called dark energy, which is usually represented by a cosmological constant ¤ associated to the vacuum energy density. All observational data available so far are in good agreement with the concordance cosmic ¤CDM model. Nevertheless, such models are plagued with several problems thereby inspiring many authors to propose alternative candidates in the relativistic context. In this thesis, a new kind of accelerating flat model with no dark energy and fully dominated by cold dark matter (CDM) is proposed. The number of CDM particles is not conserved and the present accelerating stage is a consequence of the negative pressure describing the irreversible process of gravitational particle creation. In order to have a transition from a decelerating to an accelerating regime at low redshifts, the matter creation rate proposed here depends on 2 parameters (y and ߯): the first one identifies a constant term of the order of H0 and the second one describes a time variation proportional to he Hubble parameter H(t). In this scenario, H0 does not need to be small in order to solve the age problem and the transition happens even if there is no matter creation during the radiation and part of the matter dominated phase (when the ß term is negligible). Like in flat ACDM scenarios, the dimming of distant type Ia supernovae can be fitted with just one free parameter, and the coincidence problem plaguing the models driven by the cosmological constant. ACDM is absent. The limits endowed with with the existence of the quasar APM 08279+5255, located at z = 3:91 and with an estimated ages between 2 and 3 Gyr are also investigated. In the simplest case (ß = 0), the model is compatible with the existence of the quasar for y > 0:56 whether the age of the quasar is 2.0 Gyr. For 3 Gyr the limit derived is y > 0:72. New limits for the formation redshift of the quasar are also established

Teoria semi-clássica para super rede magnética formada por materiais ferromagnético e antiferromagnético

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Testes cinemáticos em cosmologia com decaimento do vácuo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Análise em conjunta de testes cosmológicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Efeito nernst anômalo em Materiais com anisotropia magnetocristalina (110)

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Polaritons em materiais magnéticos nanoestruturados

In this work we present a theoretical study about the properties of magnetic polaritons in superlattices arranged in a periodic and quasiperiodic fashíons. In the periodic superlattice, in order to describe the behavior of the bulk and surface modes an effective medium approach, was used that simplify enormously the algebra involved. The quasi-periodic superlattice was described by a suitable theoretical model based on a transfer-matrix treatment, to derive the polariton's dispersion relation, using Maxwell's equations (including effect of retardation). Here, we find a fractal spectra characterized by a power law for the distribution of the energy bandwidths. The localization and scaling behavior of the quasiperiodic structure were studied for a geometry where the wave vector and the external applied magnetic field are in the same plane (Voigt geometry). Numerical results are presented for the ferromagnet Fe and for the metamagnets FeBr2 and FeCl2

Desempenho de pacientes com acidente vascular encefalico em testes de reconhecimento de tividades de vida diaria com frequencia autocontrolada e pre- determinada Luciana Protásio de Melo Natal 2009

The stimulation of motor learning is an important component to a rehabilitation and type of practice used is de basic importance to Physiotherapy. The motor skills are the types more basic of behavior that subjects must acquire throughout its lives and observational learning one of forms for its acquisition. Objective: This study aimed to compare performance of patients post- stroke on test of recognition of activities of day life using self-controlled and externally determined practice. Intervention: Forty subjects had been evaluated, 20 stroke patients (the mean age was 57,9?}6,7 years, schooling 6,7?}3,09 years and time of injury 23,4?}17,2 months) and 20 health subjects (the mean age 55,4?}5,9 years and schooling 8?}3,7 years). All was evaluated about independence functional (FIM) and cognitive state (MMSE), and patients were also evaluated about neurologic state (NIHSS). Later, all realized a recognition of activities of day life test (drink water and speak to telephone) on self-controlled (PAUTO and CAUTO) and externally determined (P20 and C20) frequency. The stroke subjects also were examined for a three-dimensional system of kinematic analysis, when they have drink water. The statistic analysis was realized for chi-square and t Student tests. Results: This was not difference, about number of rightness, between groups of self-controlled and externally determined practice (p0,005), and also not between patients and control groups (p0,005). Patients mean velocity (PAUTO: 141,1mm/sec and P20: 141,6mm/sec) and peak velocity (PAUTO: 652,1mm/sec and P20: 598,6mm/sec) were reduced, as well as the angles reached for elbow (PAUTO: 66,60 and 124,40; P20: 66,30 and 128,50 extension e flexion respectively) regarding literature. Conclusions: The performance on recognition of activities of day life test was similar between on self-controlled and externally determined frequency, showing both technique may be used to stimulate motor learning on chronic patients after stroke

Avaliação da cinemática do complexo tóracoabdominal durante repouso e endurance muscular respiratória em obesos

Background: Obesity may affect the respiratory system, causing changes in respiratory function and in the pulmonary volumes and flows. Objectives: To evaluate the influence of obesity in the movement of thoracoabdominal complex at rest and during maximal voluntary ventilation (MVV), and the contribution between the different compartments of this complex and the volume changes of chest wall between obese and non-obese patients. Materials and Methods: We studied 16 patients divided into two groups: the obese group (n = 8) and group non-obese (n = 8). The two groups were homogeneous in terms of spirometric characteristics (FVC mean: 4.97 ± 0.6 L - 92.91 ± 10.17% predicted, and 4.52 ± 0.6 L - 93.59 ± 8.05%), age 25.6 ± 5.0 and 26.8 ± 4.9 years, in non-obese and obese respectively. BMI was 24.93 ± 3.0 and 39.18 ± 4.3 kg/m2 in the groups investigated. All subjects performed breathing calm and slow and maneuver MVV, during registration for optoelectronic plethysmography. Statistical analysis: we used the unpaired t test and Mann-Whitney. Results: Obese individuals had a lower percentage contribution of the rib cage abdominal (RCa) during breathing at rest and VVM. The variation of end expiratory (EELV) and end inspiratory (EILV) lung volumes were lower in obese subjects. It has been found asynchrony and higher distortion between compartments of thoracoabdominal complex in obese subjects when compared to non-obese. Conclusions: Central obesity impairs the ventilation lung, reducing to adaptation efforts and increasing the ventilatory work

Influência da Dureza dos Discos Abrasivos no Corte de Materiais Dúcteis

O corte de materiais por disco abrasivo é um dos processos que apresentam as melhores características de economia, eficiência e rapidez sendo muito utilizado no meio industrial. Fatores como porcentagens e homogeneidade da mistura dos componentes, tamanho, forma (abrasividade), tenacidade e dureza dos grãos abrasivos, tipos de ligantes e de abrasivos, velocidade de corte e velocidade de mergulho influenciam na segurança, no desempenho e comportamento da operação. Este trabalho apresenta um estudo sobre a influência da dureza dos discos abrasivos no desempenho do processo de corte em operações do tipo remoção a seco. O aumento da dureza dos discos propiciou um aumento da força tangencial de corte e da relação G, devido à mais forte ligação entre o grão e o ligante no compósito. Os resultados mostram que a dureza dos discos abrasivos afeta a economia, pois influencia na vida útil dos discos abrasivos em termos de números de cortes proporcionados; a produtividade, pois está relacionada com o número de trocas de discos desgastados; os esforços necessários para a operação, pois estão relacionados com as forças tangenciais de corte.