781 resultados para poliacrilonitrila modificada


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Este trabalho apresenta uma discusso sobre o estudo dos efeitos trmicos e elsticos decorrentes da presso de sustentao presentes nos mancais. Para tanto, prope-se um modelo matemtico baseado nas equaes para mancais curtos considerando a regio de cavitao e utilizando o princpio da continuidade de massa. Com isto, deduzem-se as equaes para o mancal a partir das equaes de Reynolds e da energia, aplicando uma soluo modificada para a soluo de Ocvirk, sendo as equaes resolvidas numericamente pelo Mtodo das Diferenas Finitas. Somado o tratamento de mecnica dos fluidos, o trabalho discute dois modelos trmicos de previso de temperatura mdia do fluido e sua influncia no campo de presso, apresentando grficos representativos do campo de presso e de temperatura, assim como as diferenas e implicaes das diferenas. Para o clculo de deformao da estrutura, utiliza-se um Modelo de Elementos Finitos para uma dada geometria, fazendo-se uma avaliao da variao do campo de presso e o quanto essa diferena afeta as demais propriedades do fluido. Por fim, com o modelo completo, calcula-se o quanto esse modelamento para mancais curtos se aproxima de solues para mancais finitos, com base em resultados da literatura, chegando a desvios quase oito vezes menores que os previstos pela literatura. Alm disso, pode-se estabelecer a abrangncia do modelo, ou seja, prever as condies em que suas propriedades so vlidas e podem ser utilizadas para estudos iniciais.

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This article is an updated and modified version of a Spanish article published in MonTi 6 (cf. Tarp 2014a). It deals with specialised translation dictionaries. Based on the principles of the function theory, it analyses the different phases and sub-phases of the translation process from a lexicographical perspective and shows that a translation dictionary should be much more than a mere bilingual dictionary if it really pretends to meet its users complex needs. Thereafter, it presents a global concept of a translation dictionary which includes various mono- and bilingual components in both language directions. Finally, the article discusses, by means of two concrete online projects, how this concept can be applied on the Internet in order to develop high-quality translation dictionaries with quick access to data that are still more adapted to the needs of each translator.

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Despus de ms de treinta aos, la ley de costas espaola ha sido profundamente modificada. Sigue en vigor, excepto en aquellos aspectos que se han revisado, pero los cambios son tan profundos que se ha dibujado un escenario notablemente distinto al anterior. En este trabajo se recogen los motivos que han hecho de la ley de 1988 una norma difcil de aplicar, as como la controversia generada especialmente por la transformacin de los propietarios de viviendas situadas en el dominio pblico, en titulares de un derecho de ocupacin temporal. Los efectos de los informes de la Comisin de Peticiones del Parlamento Europeo, emitidos en 2009 y 2013, han sido tambin determinantes en la redaccin de la Ley 2/2013 de proteccin y uso sostenible del litoral y de modificacin de la Ley 22/1988, de Costas.

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Actualmente se vislumbra a nivel mundial, una creciente preocupacin por mejorar la enseanza de las ciencias y de reforzar el reconocimiento de lo que la misma implica en la adquisicin de habilidades que permitan un mejor desempeo en la vida cotidiana y en la toma de decisiones, tanto individuales como colectivas. Los docentes de nuestro medio no son ajenos a esta realidad. Es por ello que, teniendo en cuenta la importancia del trabajo interdisciplinario, consideraron oportuno solicitar a una institucin de ciencia como es la Universidad, se contine con la organizacin de eventos que propicien el acercamiento entre el nivel universitario y el secundario, a fin de poder transferir conocimientos y experiencias desde el primero hacia el segundo. Se fundamenta este pedido en experiencias previas que reconocen como valiosas, puesto que implican no slo la divulgacin de lo que es la ciencia y sus alcances, sino tambin una valorizacin de la misma como parte de nuestra vida. Estas instancias permiten, a la vez, una aproximacin de sus alumnos al nivel superior de educacin, donde muchos de ellos en un futuro cercano continuarn su formacin. A travs de este proyecto se intenta cubrir reas de vacancia en la temtica referida, a travs de un trabajo que involucra estudiantes de nivel secundario que han optado por la formacin en las Ciencias Naturales y por lo tanto presentan un mayor inters en ampliar sus conocimientos en el rea, ms all de lo estrictamente curricular. El objetivo general de este plan de trabajo, es lograr: a) desmitificar la funcin y actividad del investigador cientfico, frecuentemente mal interpretada o desconocida por gran parte de la sociedad y b) colaborar con los docentes de ciencias del nivel escolar para lograr un despertar a la curiosidad cientfico-tecnolgica en los alumnos, a la vez de aproximarse a la idea de que es posible no slo adquirir conocimientos, sino tambin generarlos. Se trabajar empleando diferentes situaciones de aprendizaje, como charlas informativas, visitas a un laboratorio de investigacin y la realizacin de una actividad prctica con animales de laboratorio, finalizando el proyecto con el diseo de experimentos por parte de los alumnos y supervisados por los docentes, que al final sern puestos en comn en un plenario. Consideramos que esta propuesta constituye una clara situacin de alfabetizacin cientfica, que en un futuro puede ser ampliada y modificada, segn la respuesta que se obtenga por parte de sus destinatarios y de la evaluacin que los responsables hagan de la misma. Para esta oportunidad se ha logrado el acuerdo con las autoridades de dos instituciones de la ciudad de Crdoba, el Colegio Jess Mara y el Instituto Nuestra Seora, donde el proyecto ya ha sido aplicado (por primera vez en el ao 2013) y se ha solicitado su continuidad. Se trabajar con grupos de 30-40 alumnos por vez, correspondientes a los cursos del ciclo polimodal (5 6 ao) con orientacin en Ciencias Naturales. No obstante, el objetivo de quienes estn a cargo de este proyecto es lograr, en el futuro, convenios con otros centros educativos, ya sea del mbito privado o estatal.

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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"Regla modificada y suma breue de las Constituciones sin aadir, quitar, ni glosar que por los religiosos legos se ponen en romane", ltimas [54] h. sin fileteado.

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Mining is an activity of great economic and social value, assisting in the development of the country. However, it can be extremely harmful to the environment if no proper waste management study exists as mitigation measure its effects. Sample some of these harmful effects are pollution: water, through the seepage of waste into the groundwater; soil; of fauna and flora; sound (due to the noise of machines); visual from the residue stored in the open, changing the local landscape; and air. One way to mitigate environmental impacts caused by mining is the proper management of their waste through their use on highways. To that end, this paper proposes to give an appropriate destination to grit coming from the beneficiation of scheelite, due to mining activity from mining group Tomaz Salustino in Breju mine, located in the city of Currais Novos in the state of Rio Grande do Norte. This work was developed in four stages. The first comprised the chemical and mineralogical tests, DRX and FRX in which they sought to discover the composition of the material studied. The next step involved the physical characteristics of the waste by means of specific tests and grinding the solid mass, LL and LP. The third stage included the specific tests applied to the pavement, with the compaction test and test Index Support California. Finally, the fourth stage was the mechanical characterization, represented by direct shear tests, both in the flooded condition and not in flooded condition. The technical feasibility of using the modified energie compacted in layers of subbase power has been verified. In normal and intermediate energies is feasible to use less noble as layers as the subgrade. The incorporation of the waste in layers of road pavements provide an alternative to conventionally used in paving aggregates, providing a proper disposal of tailings from scheelite, as well as environmental preservation

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In this study we evaluated the capacity removal of PAHs in an oily solution between the bentonite hydrofobized with linseed oil and paraffin with natural bentonite. Analyses of natural bentonite and hydrofobized were made by the characterization techniques: (1) Thermogravimetric Analysis (TGA), which aimed to evaluate the thermal events due to mass loss, both associated with the exit of moisture and decomposition of clay as due to hidrofobizante loss agent. (2) Analysis of X-ray diffraction (XRD) in order to determine the mineralogical phases that make up the structure of clay and (3) Spectrophotometry in the infrared region used to characterize the functional groups of both the matrix mineral (bentonite) and the hidrofobizantes agents (linseed oil and paraffin). We used a factorial design 24 with the following factors; hidrofobizante, percent hidrofobizante, adsorption time and volume of the oily solution. Analyzing the factorial design 24 was seen that none of the factors apparently was more important than the others and, as all responses showed significant values in relation to the ability of oil removal was not possible to evaluate a difference in the degree of efficiency the two hidrofobizantes. For the new study compared the efficiency of the modified clay, with each hidrofobizante separately in relation to their natural form. As such, there are four new factorial designs 23 using natural bentonite as a differentiating factor. The factors used were bentonite (with and without hydrophobization), exposure time of the adsorbent material to the oily solution and volume of an oily solution, trying to interpret how these factors could influence the process of purifying water contaminated with PAHs. Was employed as a technique for obtaining responses to fluorescence spectroscopy, as already known from literature that PAHs, for presenting combined chains due to condensation of the aromatic rings fluoresce quite similar when excited in the ultraviolet region and as an auxiliary technique to gas chromatography / mass spectrometry (GC-MS) used for the analysis of PAHs in order to complement the study of fluorescence spectroscopy, since the spectroscopic method only allows you an idea of total number of fluorescent species contained in the oil soluble. The result shows an excellent adsorption of PAHs and other fluorescent species assigned to the main effect of the first factor, hydrophobization for the first planning 23 BNTL 5%, for 93% the sixth stop in the second test (+-+),factorial design 23 BNTL 10%, the fourth test (++-) with 94.5% the third factorial design 23 BNTP 5%, the second test (+--) with 91% and the fourth and final planning 23 BNTP 10%, the last test ( + + +) with 88%. Compared with adsorption of bentonite in its natural form. This work also shows the maximum adsorption of each hidrofobizante

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Este estudo de carter qualitativo, com base em metodologia pesquisa ao, procurou descrever caractersticas funcionais da estratgia de ensino Imitating Art, construda com base em mtodos de dramatizao, soluo de problemas e tempestade cerebral e alicerada no processo de ensino de arte do conhecer, apreciar e fazer arte. Participaram da pesquisa 96 alunos do ensino em sade com idade mdia de 21 anos. Com o objetivo de desenhar as caractersticas funcionais da estratgia, a mesma foi planejada, descrita, modificada e avaliada em 4 etapas: experimentao, metodizao, adequao e replicao. Cada etapa foi verificada a partir de avaliao observacional pelos docentes envolvidos e anlise de contedo sobre as respostas dos alunos participantes, em instrumento de avaliao prprio. Da fase experimental participaram 14 alunos dos quais 100 % aprovaram a estratgia. A anlise de contedo mostrou Identificao de ferramentas cognitivas e afetivas (30,6%), caractersticas da atividade (22,2%), e mediao de trabalho em grupo (16,7%). A observao identificou ativo trabalho atitudinal em uma dinmica de grupo criativa. Na fase de metodizao participaram 31 alunos, dos quais 96,9% aprovaram a estratgia. Na anlise de contedo, as ideias mais presentes foram, dificuldades encontradas pelos participantes (28%), identificao de ferramentas cognitivas e afetivas (17,6%), Implicao da estratgia no cotidiano profissional (13,2%) e mediao do trabalho em grupo (13,2%). Na fase de Adequao, participaram 32 alunos, dos quais 90,7% demonstraram aprovao da estratgia. A avaliao dos participantes evidenciou como mais importante a mediao do trabalho em grupo (29,6%), identificao de ferramentas cognitivas e afetivas (21,3%) e caractersticas da atividade (19,7%). A fase de replicao teve 19 alunos, dos quais 100% aprovaram a estratgia e cuja avaliao demonstrou principalmente dificuldades encontradas pelo participante (27,8%), mediao do trabalho em grupo (25%) e Habilidade criativa da atividade (22,2%). A avaliao bidimensional mostrou que se constitui como uma estratgia de abordagem ativa e colaborativa, podendo ser usada como instrumento linear de diagnstico e incremento de competncias atitudinais tais como criatividade e trabalho em grupo.

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Currently the market requires increasingly pure oil derivatives and, with that, comes the need for new methods for obtaining those products that are more efficient and economically viable. Considering the removal of sulfur from diesel, most refineries uses catalytic hydrogenation process, the hydrodesulfurization. These processes needs high energy content and high cost of production and has low efficiency in removing sulfur at low concentrations (below 500 ppm). The adsorption presents itself as an efficient and economically viable alternative in relation to the techniques currently used. With that, the main purpose of this work is to develop and optimize the obtaining of new adsorbents based on diatomite, modified with two non ionic surfactants microemulsions, adding efficiency to the material, to its application on removal of sulfur present in commercial diesel. Analyses were undertaken of scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray fluorescence (XRF), thermogravimetry (TG) and N2 adsorption (BET) for characterization of new materials obtained. The variables used for diatomite modification were: microemulsion points for each surfactant (RNX 95 and UNTL 90), microemulsion aqueous phase through the use or non-use of salts (CaCl2 and BaCl2), the contact time during the modification and the contact form. The study of adsorption capacity of materials obtained was performed using a statistical modeling to evaluate the influence of salt concentration in the aqueous phase (20 ppm to 1500 ppm), finite bath temperature (25 to 60 C) and the concentration of sulphur in diesel. It was observed that the temperature and the concentration of sulphur (300 to 1100 ppm) were the most significant parameters, in which increasing their values increase the ability of modified clay to adsorb the sulphur in diesel fuel. Adsorption capacity increased from 0.43 to mg/g 1.34 mg/g with microemulsion point optimization and with the addition of salts.

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Mining in Brazil has a key role in economic and social development, contributing directly to improve the lives of the population. However, the mining activity even if done responsibly and with a proper study of waste management to reduce the impact of its effects, may cause harmful damage to the environment. Other forms of pollution are also caused due to mining activity. The visual pollution caused by the waste storage at open sky, in addition to the noise pollution caused by the excessive noise of the machines both in the extraction of ore, as in processing. An alternative way to lessen the environmental impacts caused by mining is the use of waste in layers that will compose the pavements along the highways. Thus, this work sets out to give a proper disposal of the wastes from the processing of iron ore, resulting from the mining activity of the group of mining Mhag Services and Mining S/A, in the mine of Bonito, located in Jucurutu, a town in the state of Rio Grande do Norte. The residues of the iron ore were stabilized with a granular soil from the city of Macaiba, also in the state of Rio Grande do Norte, which is being used in the duplication of the BR-304 referring to the entitled passage of Reta Tabajara. The present work was developed in three stages, being the first one divided by the chemical and mineralogical tests, by the tests of physical characterization and by the tests of paving for the residues of the iron ore. The second stage corresponds to the same tests being performed for granular soil. The third stage includes the essays abovementioned for three different mixtures of iron ore waste and granular soil, being they: 15% of iron-ore waste and 85% of granular soil, 25% of iron-ore waste and 75% of granular soil, 50% of iron-ore waste and 50% of granular soil. The technical feasibility of using waste from the iron ore beneficiation was checked, compressed in the intermediate energy and modified for use in base layers, sub-base, reinforcement subgrade and subgrade. The incorporation of the residues originating from the improvement of the iron ore in highways will provide an alternative to the use of aggregate conventionally used in the paving, besides preserving the environment.

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This work proposes a modified control chart incorporating concepts of time series analysis. Specifically, we considerer Gaussian mixed transition distribution (GMTD) models. The GMTD models are a more general class than the autorregressive (AR) family, in the sense that the autocorrelated processes may present flat stretches, bursts or outliers. In this scenario traditional Shewhart charts are no longer appropriate tools to monitoring such processes. Therefore, Vasilopoulos and Stamboulis (1978) proposed a modified version of those charts, considering proper control limits based on autocorrelated processes. In order to evaluate the efficiency of the proposed technique a comparison with a traditional Shewhart chart (which ignores the autocorrelation structure of the process), a AR(1) Shewhart control chart and a GMTD Shewhart control chart was made. An analytical expression for the process variance, as well as control limits were developed for a particular GMTD model. The ARL was used as a criteria to measure the efficiency of control charts. The comparison was made based on a series generated according to a GMTD model. The results point to the direction that the modified Shewhart GMTD charts have a better performance than the AR(1) Shewhart and the traditional Shewhart.

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The objective of this study was to determine the seasonal and interannual variability and calculate the trends of wind speed in NEB and then validate the mesoscale numerical model for after engage with the microscale numerical model in order to get the wind resource at some locations in the NEB. For this we use two data sets of wind speed (weather stations and anemometric towers) and two dynamic models; one of mesoscale and another of microscale. We use statistical tools to evaluate and validate the data obtained. The simulations of the dynamic mesoscale model were made using data assimilation methods (Newtonian Relaxation and Kalman filter). The main results show: (i) Five homogeneous groups of wind speed in the NEB with higher values in winter and spring and with lower in summer and fall; (ii) The interannual variability of the wind speed in some groups stood out with higher values; (iii) The large-scale circulation modified by the El Nio and La Nia intensified wind speed for the groups with higher values; (iv) The trend analysis showed more significant negative values for G3, G4 and G5 in all seasons and in the annual average; (v) The performance of dynamic mesoscale model showed smaller errors in the locations Paracuru and So Joo and major errors were observed in Triunfo; (vi) Application of the Kalman filter significantly reduce the systematic errors shown in the simulations of the dynamic mesoscale model; (vii) The wind resource indicate that Paracuru and Triunfo are favorable areas for the generation of energy, and the coupling technique after validation showed better results for Paracuru. We conclude that the objective was achieved, making it possible to identify trends in homogeneous groups of wind behavior, and to evaluate the quality of both simulations with the dynamic model of mesoscale and microscale to answer questions as necessary before planning research projects in Wind-Energy area in the NEB