138 resultados para Noblesa-Castella


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El trabajo no está publicado

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Se pretende revisar algunos aspectos de la problemática existente en torno a la orientación vocacional en la Escuela Técnica Superior de Ingenieros Industriales de Sevilla. 213 individuos, todos varones, de tercer curso de ingenieros industriales, de edades comprendidas entre los 19 y 26 años, que realizaron dichos estudios durante los cursos 1974-75 y 1975-76. Todos los individuos tienen aprobados completamente los tres primeros cursos. Se consideran dos variables o grupos de variables: a) las características psicológicas de los estudiantes; b) las características generales de la escuela en aspectos tales como grado de dificultad de cada uno de los cursos, etc., medidas a través de los expedientes académicos de los individuos de la muestra a partir de todas las variables consideradas se ha procedido al cálculo de una matriz de correlaciones. Del análisis de la misma se ha intentado: 1) seleccionar la prueba psicométrica más adecuada de entre las utilizadas; 2) realizar una predicción académica en función de dichas pruebas; 3) conocer el grado de concomitancia de unas asignaturas respecto a otras. Pruebas psicométricas aplicadas: a) inteligencia, Raven, WAIS y AMPE; b) personalidad: CEPs; c) hábitos de estudio: inventario de hábitos de estudio; d) aptitudes específicas: mecánica, rotación de figuras macizas. Para el conocimiento de la trayectoria académica del alumno se ha utilizado su expediente académico. Análisis de correlaciones, media, desviación tipo. Con 91 variables se construyó una matriz de correlaciones de 91 x 91 elementos, obteniéndose 4095 correlaciones. De estas correlaciones se obtuvieron 874 significativas al 1 y al 5. Destaca la ausencia de correlación entre los hábitos de estudio y los de personalidad. Las condiciones ambientales presentan una alta correlación (r=0,43) con la asimilación de contenidos, con la utilización de materiales (r=0,45) y con la planificación de los estudios (r=0,42). Es el factor de razonamiento del AMPE el que mayor número de correlaciones con el expediente académico presenta. La personalidad no presenta prácticamente correlaciones con el expediente académico, al igual que el inventario de hábitos de estudio. Las asignaturas de Electrónica III, Termodinámica, Materiales y Química obtienen el máximo número de correlaciones, constituyendo el núcleo más importante de la escuela. Del conjunto de pruebas aplicadas, inteligencia, personalidad y hábitos de estudio, tan sólo la batería correspondiente a inteligencia parece mantener correlación con el expediente. En cuanto a este último, cabe destacar el elevado grado de dificultad de los dos primeros cursos, como demuestran los bajos promedios de calificaciones (4 y 4,15). Se proponen distintas líneas para futuras investigaciones, que van desde una ampliación de la muestra utilizada en la presente, hasta el análisis de las relaciones entre variables intelectuales y académicas con variables socioeconómicas o con el éxito profesional.

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Se ha acometido la investigación de tres puestos de trabajo, seleccionados, con vistas a averiguar qué formación se precisa para dotar a las personas de los conocimientos, habilidades y destrezas necesarias para desarrollarlos. Se han elegido tres puestos de trabajo concretos en tres empresas: operador de cuadro de alimentación de subestaciones; instalador de líneas aéreas de media tensión; instalador de redes subterráneas. En cada empresa se han estudiado los trabajos. Se han descrito minuciosamente, en su posición genérica dentro de la organización, tareas que las componen, material empleado, características peculiares del puesto y de la persona que hubiera de ocuparlo con eficacia, tanto en el aspecto somático como psíquico. Han merecido especial atención consideraciones sobre rasgos de personalidad, directamente relacionados con la eficacia del servicio y la seguridad con el hacer. Se ha dado el desarrollo conveniente a los conocimientos a adquirir, tanto en el terreno teórico como en el de los hábitos a desarrollar mediante ejercicios prácticos correspondientes. A partir de los datos obtenidos se han revisado los actuales planes de educación. Observación directa y muy detallada de los puestos de trabajo. Encuestas y entrevistas a operarios, mandos intermedios y técnicos. Datos documentales sobre el tema. Además de un cuestionario sobre el contenido del trabajo se utilizó un quien auxiliar para facilitar las respuestas de los entrevistados. Análisis de los trabajos desde el punto de vista psicosomático. Para el puesto de operador de cuadro se consideran innecesarios los tres cursos clásicos de oficialia, bastando dos cursos o uno de enseñanza acelerada. Son necesarios más conocimientos de alta tensión y de seguridad en el trabajo. Para el puesto de instalador de líneas aéreas de media tensión, basta con dos cursos regulares para su formación si se trata de aprendices con cinco cursos de EGB, y un curso normal de FP acelerada si se trata de un adulto sin otro oficio o procedentes de otra profesión. Para el puesto de instalador de redes subterráneas, por su mucha especialización, en general, puede afirmarse que con un curso de electricidad general a nivel de oficialía, y otro curso dedicado a la especialidad, resultaría tiempo suficiente de enseñanza. Para adultos bastaría con un curso de FP acelerada. En anexos se añaden unos programas indicativos de las materias que pueden constituir los mencionados cursos. Se llega, contrariamente a lo que sería compatible con un planteamiento educativo estático tradicional, a la conclusión de la inutilidad de una programación demasiado detallada de la formación profesional, después de apreciar la dinámica de la evolución de estas profesiones, y la relativa variedad de su ejecución concreta en los diversos ambientes.

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Unidades did??cticas sobre aspectos ling????sticos y culturales para estudiantes de espa??ol de ense??anza secundaria en los sistemas educativos brit??nicos e irland??s, elaboradas por grupos de trabajo de auxiliares de conversaci??n de espa??ol.

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Los Sistemas de Información Geográfica (SIG) son una herramienta válida para el estudio de los paisajes antiguos. Los SIG se pueden configurar como un conjunto de medios analíticos útiles para comprender la dimensión espacial de las formaciones sociales y su dinámica histórica. En otras palabras, los SIG posibilitan un acercamiento válido a la racionalidad de las conductas espaciales de una comunidad y a las pautas globales de una sociedad que quedan plasmadas en la morfología de un paisaje. Atendiendo a la abundante y creciente oferta de programas informáticos que procesan y analizan información espacial, enfocaremos las ventajas que supone la adopción de soluciones libres y de código abierto para la investigación arqueológica de los paisajes. Como ejemplo presentaremos el modelado coste-distancia aplicado a un problema locacional arqueológico: la evaluación de la ubicación de los asentamientos respecto a los recursos disponibles en su entorno. El enfoque experimental ha sido aplicado al poblamiento castreño de la comarca de La Cabrera (León). Se presentará una descripción detallada de cómo crear tramos isócronos basados en el cálculo de los costes anisótropos inherentes a la locomoción pedestre. Asimismo, la ventaja que supone la adopción del SIG GRASS para la implementación del análisis

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A lo largo de este estudio se pone de relieve el papel fundamental que desempeñaron los miembros del cabildo en el proyecto y construcción de la cabecera de la catedral gerundense. Para este grupo de personajes, básicamente procedentes de la baja nobleza altoampurdanesa, la nueva empresa edilicia supuso la posibilidad de satisfacer el deseo de promover beneficios eclesiásticos así como el objetivo de disponer de nuevos espacios —las capillas de la girola— concebidos como expresión de la gloria y la memoria individual y del linaje

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O rei castelhano Afonso X, o Sábio (1221-1284) é considerado como o idealizador de uma vasta obra que inclui textos de caráter jurídico, historiográfico, científico e sua produção poética. Este estudo propõe evidenciar o caráter propagandístico da obra afonsina considerando as condições de produção e difusão dos textos e a sua relação com o projeto político centralizador do Rei Sábio. Procurando observar a maneira pela qual o pensamento político afonsino é revelado em sua obra, são aqui analisadas as imagens do rex christianus, cujo poder provém de Deus, do rex iustus, cuja função é administrar a justiça em seu reino, e do rex sapiens, que dispõe da virtude e do conhecimento necessários para bem governar.

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O tamanho ótimo de uma empresa exerce papel importante na determinação da estrutura de mercado, nas decisões de planejamento de empresas, e em políticas de regulação e antitruste. Assim, um dos principais objetivos deste trabalho foi estimar o tamanho ótimo (ou EME) das empresas para 106 setores da indústria manufatureira brasileira, num contexto de informação limitada. Outro objetivo foi analisar a mudança do tamanho ótimo das empresas devido ao processo de abertura comercial brasileiro. Para isso foram empregados dois procedimentos em sequência: Máxima Entropia (GOLAN, JUDGE & PERLOFF, 1996) e Survivor Technique (STIGLER, 1958). Primeiramente aplicamos a Máxima Entropia, para estimar as distribuições de market shares em cada setor utilizando somente medidas de concentração. Os dados se referem aos anos de 1978, 1995 e 1997. O próximo procedimento consistiu na aplicação da survivor technique a estas distribuições para encontrarmos o tamanho ótimo da empresa nos períodos pré e pós abertura comercial. Os resultados indicam que o processo de abertura comercial contribuiu para uma elevação do tamanho ótimo das empresas em mais de 60% dos setores. Este aumento ocorreu principalmente em setores capital intensivo e que apresentavam elevadas taxas de participação de empresas estrangeiras. Esses resultados corroboram os argumentos da literatura de organização industrial e comércio internacional que afirmam que o elevado protecionismo estimulou a proliferação de empresas pequenas e ineficientes que operam com escalas reduzidas e pouco competitivas.

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Structural changes in waste for zeolites synthesis are subject of many studies carried out in the synthesis of molecular sieves. These materials are named molecular sieves because they have well defined pore sizes and they have the capacity of select molecules by its size. In this work, it was studied the synthesis processes of two types of molecular sieves: pillared acid clays using as starting material one natural montmorillonite clay and the synthesis of zeolites from a silico-aluminous residue. This residue is a byproduct of the extraction of lithium -spodumene. The preparation of pillared acid clays was performed in two steps: 1° acid treatment of clay samples (time and temperature studies) and 2°pilarization of them with Al13 (Keggin ion). The temperature and acid concentration affect the removal of cations in the structure and porosity of the material obtained. The analysis of X-ray diffraction (XRD) and infrared spectroscopy (IR), showed that increasing the severity of the acid treatment compromises the structural material. Also the pore size distribution is approximately uniform. Despite presenting a structural disorganization, the samples were pillared. As evidenced by XRD increasing the basal spacing, specific area and uniform porosity by adsorption of N2. Regarding the microporous molecular sieves were synthesized zeolites A and NaP1 from a silico-aluminous residue, a byproduct of extracting lithium. The temperature and time of agitation during the synthesis were the most important factors for obtaining zeolite A. The aging of the gel and the highest crystallization time promoted the formation of zeolite NaP1 using a Si / Al ratio = 3.2

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The MCM-41 mesoporous synthesis was done using rice hulls ash and chrysotile as natural alternative silica sources. For the using of these sources, chemical and thermic treatments were done in both materials. After chemical and thermic treatments, these materials were employed on the MCM-41 mesoctructures synthesis. The natural materials treated and employed in the synthesis were characterized by several techniques such as X-ray diffraction, N2 adsorption and desorption, scanning electronic microscopy and thermogravimetric analysis. MCM-41 standart samples synthetized with aerosil 200 commercial sílica were used to evaluation. The formed material from rice hulls ash showed values from BET specific area about 468 m².g-1, N2 adsorption and desorption isotherms and loss mass similar to reference materials. The silica from chrysotile calcined and leached was employed to mesoporous materials synthesis. The BET specific area showed values about 700 m².g-1, N2 adsorption and desorption isotherms type IV and loss mass similar to mesoporous materials. The formed material from calcined and leached chrysotile, without calcination, applied to phenol remotion carried high performance liquid chromatography and evaluated with organophilic clays with different treatments. By the characterization techniques were proved that mesoporous materials with lesser order that reference samples. The material formed from rice hulls ash without the calcination step achieved better adsorption results than organophilic clays

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The present work deals with the synthesis of materials with perovskite structure with the intention of using them as cathodes in fuel cells SOFC type. The perovskite type materials were obtained by chemical synthesis method, using gelatin as the substituent of citric acid and ethylene glycol, and polymerizing acting as chelating agent. The materials were characterized by X-ray diffraction, thermal analysis, spectroscopy Fourier transform infrared, scanning electron microscopy with EDS, surface area determination by the BET method and Term Reduction Program, TPR. The compounds were also characterized by electrical conductivity for the purpose of observing the possible application of this material as a cathode for fuel cells, solid oxide SOFC. The method using gelatin and polymerizing chelating agent for the preparation of materials with the perovskite structure allows the synthesis of crystalline materials and homogeneous. The results demonstrate that the route adopted to obtain materials were effective. The distorted perovskite structure have obtained the type orthorhombic and rhombohedral; important for fuel cell cathodes. The presentation material properties required of a candidate cathode materials for fuel cells. XRD analysis contacted by the distortion of the structures of the synthesized materials. The analyzes show that the electrical conductivity obtained materials have the potential to act as a cell to the cathode of solid oxide fuel, allowing to infer an order of values for the electrical conductivities of perovskites where LaFeO3 < LaNiO3 < LaNi0,5Fe0,5O3. It can be concluded that the activity of these perovskites is due to the presence of structural defects generated that depend on the method of synthesis and the subsequent heat treatment

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The development of activities the of oil and gas sector have promoted the search for suitable materials for cementing oil wells. In the state of the Rio Grande do Norte, the integrity of the cement sheath tends to be impaired during steam injection, a procedure necessary to increase oil recovery in reservoirs with low-viscosity oil. The geopolymer is a material that can be used as alternative cement, since it has been used in the production of fire-resistant components, building structures, and for the control of toxic or radioactive residues. Geopolymers result from condensation polymer alkali aluminosilicates and silicates resulting three-dimensional polymeric structures. They are produced in a manner different from that of Portland cement, which is made an activating solution that is mixed with geopolymer precursor. Among the few works studied allowed us to conclude that the pastes prepared with metakaolin as precursor showed better performance of its properties. Several studies show the addition of waste clay as a means of reducing cost and improving end of the folder properties. On this basis, the goal is to study the influence of the addition of ceramic waste in geopolymer paste. To develop the study of rheology tests were carried out, filtered, thickening time, compressive strength, free water, specific gravity and permeability, according to the American Pretoleum Institute (API). The results for all formulations studied show that the folders have high mechanical strength to a light paste; low filtrate volume, absence of free water, very low permeability, slurry, consistent with a light paste, and thickening time low that can be corrected with the use of a retardant handle. For morphological characterization, microstructural, physical, chemical and thermal tests were carried out by XRD, MEV, DTA, TG, FTIR. In the trial of XRD, it was found that geopolymer is an amorphous material, with a peak of crystalline kaolinite. In tests of TG / DTA, revealed the presence of a significant event, which represents the mass loss related to water, and also observed the reduction of weight loss by increasing the concentration of ceramic waste. In the trial of MEV, we found a uniform matrix without the presence of other phases. In the trial of FT-IR, we observed the presence of the band related to water. From all results it was determined that the optimum concentration range of use is between 2.5 and 5% of waste ceramic

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In recent years, the area of advanced materials has been considerably, especially when it comes to materials for industrial use, such as is the case with structured porosity of catalysts suitable for catalytic processes. The use of catalysts combined with the fast pyrolysis process is an alternative to the oxygenate production of high added value, because, in addition to increasing the yield and quality of products, allows you to manipulate the selectivity to a product of interest, and therefore allows greater control over the characteristics of the final product. Based on these arguments, in this work were prepared titanium catalysts supported on MCM-41 for use in catalytic pyrolysis of biomass, called elephant grass. The reactions of pyrolysis of biomass were performed in a micro pyrolyzer, Py-5200, coupled to GC / MS, the company CDS Corporation, headquartered in the United States. The catalysts Ti-MCM-41 in different molar ratios were characterized by XRD, TG / DTG, FT-IR, SEM, XRF, UV-visible adsorption of nitrogen and the distribution of particle diameter and specific surface area measurement by the BET method. From the catalytic tests it was observed that the catalysts synthesized showed good results for the pyrolysis reaction.The main products were obtained a higher yield of aldehydes, ketones and furan. It was observed that the best reactivity is a direct function of the ratio Si/Ti, nature and concentration of the active species on mesoporous supports. Among the catalysts Ti-MCM-41 (molar ratio Si / Ti = 25 and 50), the ratio Si / Ti = 25 (400 ° C and 600 ° C) favored the cracking of oxygenates such as acids , aldehydes, ketones, furans and esters. Already the sample ratio Si / Ti = 50 had the highest yield of aromatic oxygenates

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This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The activities were divided into four stages: study batch adsorption capacity of the adsorbent with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption studies were carried out under the following operating conditions: temperature 40 °C (for the pyrolysis of the sludge T = 600 °C), pressures of 0.55 to 5.05 bar (batch process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7 h and on the fixed bed was around 180 min. The results of this study showed that in batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed CO2 increases with the increases pressure, decreases with temperature increases and rises due the increase of activation temperature adsorbent. In the batch process were evaluated the breakthrough curves, which were compared with adsorption isotherms represented by the models of Langmuir, Freündlich and Toth. All models well adjusted to the experimental points, but the Langmuir model was chosen in view of its use in the dynamic model does not have implications for adsorption (indeterminacy and larger number of parameters such as occurred with others) in solving the equation. In the fixed bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the maximum adsorption percentage 46.7% at 40 °C temperature and 50 mL/min of flow rate. The model was satisfactorily fitted to the three breakthrough curves and the parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45 dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge showed a fast saturation with traces of aerosols presents in the gas phase into the fixed bed under the reaction process

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The catalytic cracking of triglycerides presents itself as a possible alternative to the production of biofuels with low emission of pollutants. In this work were synthesized the SAPO-5, the catalysts for the cracking reaction of soybean oil is presented. The solids were powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG) and infrared spectroscopy (FTIR). The analyses indicated that the synthesis method has employed to obtain materials with high surface area and high acid. The soybean oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ºC in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. The products obtained in the cracking of soybean oil were analyzed by distillation, acid number, infra-red spectroscopy, density, viscosity, carbon residue, cetane number determination and characterization. The analysis of the products obtained in the presence and in the absence of the SAPO-5 permitted to conclude that all the solids tested presented catalytic activity in the deoxygenation of final products only at the second step of the cracking process