999 resultados para Contextos cerámicos


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Os autores procedem à análise das pastas cerâmicas de 24 amostras de número de recipientes, do povoado calcolítico do Monte da Tumba, recorrendo ao microscópio petrográfico. Esta metodologia revelou-se muito eficaz e permitiu atingir conclusões importantes nos domínios da tecnologia e da análise do site-catchement. De sublinhar a constatação de que as dimensões dos elementos não plásticos das pastas argilosas não parecem relacionar-se com as dimensões nem com a espessura das paredes dos recipientes, mas com o grau de resistência e porosidade pretendidos. Registe-se igualmente que as produções cerâmicas utilizaram matérias-primas locais, num raio de distância mínimo de 750m a partir do povoado.

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Devido ao contexto económico vivido actualmente, de muita concorrência e de incerteza, impõe-se a aposta em fazer diferente, em fazer melhor e a um menor custo. Tal caminho pode ser percorrido com recurso à criatividade e inovação resultando deste binómio elementos potenciadores de mais-valias para a empresa e para o consumidor. Será que o ambiente organizacional influencia o aparecimento de criatividade e inovação? A opinião de que o ambiente é realmente muito importante para tal acontecer é partilhada por vários autores. A cultura organizacional, a forma como é considerado o indivíduo dentro da organização, como é feita a gestão de talentos, a forma como são encorajadas as ideias de todos os indivíduos pode realmente ser um factor decisivo para facilitar e encorajar a criatividade e inovação na empresa. A abordagem empírica assenta num estudo qualitativo, para o qual foram seleccionadas três empresas. A selecção de duas das empresas teve em conta o seu posicionamento no mercado como empresas inovadoras e a terceira pelo facto do seu core business estar directamente relacionado com a criatividade. Através do estudo realizado conclui-se que a cultura e o clima organizacional, ou seja, a forma como é visto o colaborador, como lhe é dado poder de decisão, como é reconhecido o seu esforço, trabalho e empenho, influencia os níveis de criatividade e inovação dentro da Organização. ABSTRACT; Due to the current economic context, marked by a fierce competition and uncertainty, it is necessary to focus on making differently, better and cheaper. Such path can be followed using creativity and innovation. Profit-boosting elements for the company and the consumer. Does the work environment affect the occurrence of creativity and innovation? Several authors share the opinion that the environment is very important for that occurrence. The organizational culture, the way how the individual is perceived inside the organization, how the management of talents is made, the ideas from all individuals are seen, can be a major to facilitate and encourage creativity and innovation in the company.

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No ano de 1998, foi o signatário solicitado a dar parecer, no âmbito das funções atribuídas, a nível municipal, ao centro de Estudos Arqueológicos do Concelho de Oeiras/Câmara Municipal de Oeiras, sobre a descoberta fortuita de ossos supostamente humanos, aparecidos no decurso de obras de beneficiação na cave do edifício onde se encontra instalada a Biblioteca Operária Oeirense.

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This research presents an outlook of the industries of red ceramic in the region next to the city of Teresina and an analysis of the ceramic products producted in this pole. The microregion investigated possesses 13 boroughs where were identified 32 ceramic in operation, being that 24 are located in Teresina, the ceramic region more important of Piauí, 1 is located in the city of Miguel Leão and 7 is located in Timon city that belongs to the state of Maranhão. The majority of ceramics are pulverized in these two cities, Teresina and Timon , responsible by a largely production independent of distance between fabric and consumer market. Furthermore, there is an artisanal production realized in other boroughs, mainly manual conformation bricks, where are producted diverse types of handicraft and ceramics utilitarian. The objective of this research is to evalue the conformity of ceramic blocks for brick of obstruction made by red ceramic industry of microregion at studying, verifying their pontentialities and adequacy in terms of production. In this research universe made a search of ceramic industries related to the Foundation CEPRO (Foundation Center of Research Social and Economic of Piauí). For the analysis of the ceramic products , were colected 60 crude bricks sample in three industries for their characterization, and 39 burned bricks sample for the Evaluation of Conformity. The results of the characterization made reached a accetptable standard in all formulations and temperature studied. The burned samples were applied to the geometric, physical and mechanical assays according to the ABNT standards (Brazilian Association of Technical Standards). The results of the physical assays showed that all the samples are at the same band recommended by standard. However, through the geometric assays just two industries did not present results according to the standard, due to lack of control in their process such as in their equipments. Taking into account the mechanical properties, only one industry investigated was not according to the standard

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In this work have been studied the preparation, characterization and kinetic study of decomposition of the polymerizing agent used in the synthesis under non-isothermal condition ceramics PrMO3 of general formula (M = Co and Ni). These materials were obtained starting from the respective metal nitrates, as a cations source, and making use of gelatin as polymerizing agent. The powders were calcined at temperatures of 500°C, 700°C and 900°C and characterized by X-ray Diffraction (XRD), Thermogravimetric Analysis (TG / DTG/ DTA), Infrared Spectroscopy (FTIR), Temperature Programmed Reduction (TPR) and Scanning Electron Microscopy (SEM). The perovskite phase was detected in all the X-rays patterns. In the infrared spectroscopy observed the oxide formation as the calcination temperature increases with the appearance of the band metal - oxygen. The images of SEM revealed uniform distribution for the PrCoO3 and particles agglomerated as consequence of particle size for PrNiO3. From the data of thermal analysis, the kinetics of decomposition of organic matter was employed using the kinetics methods called Model Free Kinetics and Flynn and Wall, in the heating ratios 10, 20 and 30° C.min-1 between room temperature and 700°C. Finally, been obtained the values of activation energy for the region of greatest decomposition of organic matter in samples that were determined by the degree of conversion (α)

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One of waste produced on large scale during the well drilling is the gravel drilling. There are techniques for the treatment of the same, but there isn t consensus on what are the best in terms of economic and environmental. One alternative for disposal of this waste and objective of this paper is the incorporation and immobilization of gravel clay matrix to assess their technological properties. The Raw Materials used were characterized by the following techniques: Chemical Analysis by X-ray fluorescence (XRF), mineralogical analysis by X-ray Diffraction (XRD), Grain Size Analysis (FA) and Thermal Analysis by Thermogravimetry (TG) and thermodiferential (DTA). After characterizing, samples were formulated in the following percentages: 0, 5, 10, 15, 25, 50, 75, 100% (weight) of gravel drilling, then the pieces were pressed, dried (110 ° C) and sintered at temperatures of 850, 950 and 1050 ° C. After sintering, samples were tested for water absorption, linear shrinkage, flexural strength, porosity, density, XRD and test color. The results concluded that the incorporation of gravel drilling is a viable possibility for solid masonry bricks and ceramic blocks manufacture at concentrations and firing temperature described here. Residue incorporation reduces an environmental problem, the cost of raw materials for manufacture of ceramic products

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Inorganic pigment comprises a host lattice, which is part of the chromophore component (usually a transition metal cation) and possible components modifiers, which stabilize, add or restate the properties pigments. Among the materials with spinel, ferrites, and the chromite stand out, because they have broad technological importance in the area of materials, applicability, pigments, catalytic hydrogenation, thin film, ceramic tiles, among others. The present work, pigments containing CuFe2O4, CuCr2O4,e CuFeCrO4, were synthesized by a method that makes use of gelatin as organic precursor using their application to ceramic pigments. The pigments were characterized by X-ray diffraction (XRD), Infrared spectroscopy, scanning electron microscopy (SEM) spectroscopy in the UV-visible and Colorimetry. The results confirmed the feasibility of the synthetic route used, with respect to powders synthesized, there is the formation of spinel phase from 500°C, with an increase in crystallinity and the formation of other phases. The pigments were shown to be crystalline and the desired phases were obtained. The copper chromite have hues ranging from green to black according to the calcination temperature, while the copper chromite doped with iron had brownish. The ferrites showed copper color and darker brown to black, which may indicate an interesting factor because of the importance of black pigment

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[ES]En el presente trabajo, se abordan las formas cambiantes en las relaciones de socialidad de los adolescentes menores, la influencia de los avances tecnológicos en estas, así como los conflictos entre iguales que emergen en estos nuevos espacios, enfocando el trabajo en el fenómeno del cyberbullying desde un punto de vista criminológico. El objetivo ha consistido en analizar las nuevas formas de relación social que se expanden hoy en día, sobre todo por la irrupción de Internet como forma de interacción social y reconocer las conductas de riesgo que comienzan a aparecer en este ámbito, para identificar las formulas necesarias de prevención. La primera parte del trabajo está centrada en contextualizar la forma de socialidad, desde una conceptualización amplia hasta las características actuales derivadas del uso de la tecnología como herramienta de relación social, recogiendo los debates generados en torno al posible debilitamiento del capital social. En el siguiente apartado, se explora el ciberespacio, sus riesgos y oportunidades delictivas, buscando analizar posteriormente y en profundidad el cyberbullying, así como sus factores de victimización y sus similitudes y diferencias con respecto al bullying tradicional. A continuación, con el fin de subrayar y extraer las características que debe tener un programa de prevención, se expone una iniciativa pionera, a modo de estudio de caso. En esta se utiliza la formación en mediación de los propios menores para resolver o prevenir estas problemáticas, implantado en un instituto público de Zaragoza.

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The development and study of detectors sensitive to flammable combustible and toxic gases at low cost is a crucial technology challenge to enable marketable versions to the market in general. Solid state sensors are attractive for commercial purposes by the strength and lifetime, because it isn t consumed in the reaction with the gas. In parallel, the use of synthesis techniques more viable for the applicability on an industrial scale are more attractive to produce commercial products. In this context ceramics with spinel structure were obtained by microwave-assisted combustion for application to flammable fuel gas detectors. Additionally, alternatives organic-reducers were employed to study the influence of those in the synthesis process and the differences in performance and properties of the powders obtained. The organic- reducers were characterized by Thermogravimetry (TG) and Derivative Thermogravimetry (DTG). After synthesis, the samples were heat treated and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), analysis by specific area by BET Method and Scanning Electron Microscopy (SEM). Quantification of phases and structural parameters were carried through Rietveld method. The methodology was effective to obtain Ni-Mn mixed oxides. The fuels influenced in obtaining spinel phase and morphology of the samples, however samples calcined at 950 °C there is just the spinel phase in the material regardless of the organic-reducer. Therefore, differences in performance are expected in technological applications when sample equal in phase but with different morphologies are tested

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El presente trabajo realiza un estudio sobre los comentaristas de la Divina Comedia del siglo XIV y algunos del XV, examinando su papel como intérpretes del poema dantiano tanto desde el punto de vista literario como histórico e ideológico en el momento de transición de la Edad Media al Humanismo, tomando en cuenta las señales que de esta evolución se van encontrando ya en los comentarios inmediatamente posteriores a la muerte de Dante. Uno de los aspectos que faltaba tratar en la historia de los estudios era un trabajo comparativo sobre el modo de conocimiento de todos y cada uno de los más importantes comentaristas antiguos por lo que concierne las alegorías y el método hermenéutico utilizado. Así el análisis interpretativo en los comentarios antiguos de algunas de las alegorías más conocidas, pero también muy controvertidas, como las tres fieras y el contrapasso, ha sido el punto de partida para el presente trabajo. Se ha optado por hacer “hablar” a los comentaristas a través de un acercamiento al texto lo más directo posible, sin tomar posiciones críticas predefinidas, para favorecer un acercamiento al texto de una manera lo más filológicamente neutral...

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Com o final da Guerra Fria, o conceito e a prática da ação humanitária sofreram mudanças significativas. O surgimento das denominadas “emergências humanitárias complexas” tornou claro que as respostas humanitárias tradicionais baseadas nos princípios clássicos de imparcialidade e neutralidade já não eram suficientes ou as mais apropriadas para responder a desafios tão complexos. A década de 90 vê assim emergir um “novo humanitarismo”, que incorpora objetivos mais amplos e de longo prazo, tais como o desenvolvimento e a paz. Contudo, esta nova abordagem ao humanitarismo viu também os seus traços e implicações mais negativos e preocupantes serem reforçados com as respostas militarizadas aos ataques terroristas de 11 de setembro de 2001, criando dilemas ainda mais complexos às organizações e atores humanitários. Procura-se, com este artigo, traçar a evolução do conceito e prática do humanitarismo, olhando criticamente para as principais tendências que têm caracterizado os mais recentes paradigmas da ajuda e procurando perceber quais os grandes dilemas e desafios que se colocam ao futuro de uma ação humanitária eficaz.

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Ecologías del aprendizaje en contextos rurales. El caso de la Universidad Rural Paulo Freire de la Serranía de Ronda. Línea Estratégica de trabajo: Metodologías multimodales y participativas. 1. Introducción y objetivos El trabajo que presentamos forma parte del proyecto I+D+I “Ecologías del aprendizaje en contextos múltiples: análisis de proyectos de educación expandida y conformación de ciudadanía” financiado por MIMECO, España. El interés de este proyecto surge al considerar que buena parte de los procesos de aprendizaje relevante que activan un sentido de comunidad y ciudadanía, han venido resultando invisibles en los distintos espacios educativos y de formación del profesorado. En esta comunicación presentamos los planteamientos metodológicos que nos hacemos en uno de los contextos de esta investigación, que es el grupo que conforma la Asociación ‘Montaña y Desarrollo’ que entre sus iniciativas está la gestión y dinamización de la Universidad Rural Paulo Freire de la Serranía de Ronda. Nuestro propósito general es estudiar los mecanismos educativos que las personas y organizaciones ponen en juego a la hora de constituirse en sus grupos de interacción próxima: trabajo, familia, etc. Así mismo, como objetivos específicos para trabajar en en el mencionado contexto, destacamos - Revisar los marcos conceptuales que permitan comprender las prácticas de aprendizaje invisible y educación expandida representativas de alternativas ecologías del aprendizaje. - Generar narrativas visuales que evidencien el trabajo y los rasgos identitarios de la Asociación ‘Montaña y Desarrollo’. - Analizar los relatos de vida de las personas integrantes de esta experiencia (así como el relato colectivo), para la comprensión de la acción socio educativa en contextos rurales a través del diálogo de saberes, generación de prácticas democráticas y la participación colaborativa. - Generar espacios de diálogo con otras organizaciones, colectivos, personas… para la creación de redes y comunidades de aprendizaje. 2. Metodología. La metodología se sitúa en el paradigma cualitativo y se aborda desde el enfoque biográfico–narrativo (Rivas, 2009). Entender los fenómenos sociales desde la voz de los/as protagonistas, se sitúa como estrategia principal e indispensable en este proyecto. Para ello, tras previo acuerdo con el colectivo participante, recurrimos a la construcción de relatos de vidas y narrativas visuales como enfoque metodológico de base hacia la re-significación de cómo aprende y se aprende en el mencionado escenario de investigación. Para ello, acudimos a distintas estrategias tales como la entrevista, los grupos focales y de reflexión (que serán grabados en soportes audiovisuales), así como grupos mixtos para el desarrollo de interpretaciones, la co-contrucción de significados y el trabajo sobre los resultados parciales y finales. 3. Conclusiones. El entramado del aprendizaje ecológico y los procesos de construcción de ciudadanía son percibidos hoy como un aprendizaje invisible, informal, generativo o rizomático, fuera de los contextos educativos formales. Sin embargo, las posibilidades casi ilimitadas de comunicación abren el universo de otras formas de aprendizaje que pensamos contribuyen a los procesos de transformación personal y colectiva. Sobre esto, consideramos que la investigación educativa debe tener presente desde un enfoque metodológico, la incorporación de los sujetos como agentes clave en la toma de decisiones del proceso indagatorio y considerar la ampliación de las formas de aprendizaje hacia la participación, el componente emocional y corporal, la colaboración y la interconexión.

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The present work has as objective the development of ceramic pigments based in iron oxides and cobalt through the polymeric precursor method, as well as study their characteristics and properties using methods of physical, chemical, morphological and optical characterizations.In this work was used iron nitrate, and cobalt citrate as precursor and nanometer silica as a matrix. The synthesis was based on dissolving the citric acid as complexing agent, addition of metal oxides, such as chromophores ions and polymerization with ethylene glycol. The powder obtained has undergone pre-ignition, breakdown and thermal treatments at different calcination temperatures (700 °C, 800 °C, 900 °C, 1000 °C and 1100 °C). Thermogravimetric analyzes were performed (BT) and Differential Thermal Analysis (DTA), in order to evaluate the term decomposition of samples, beyond characterization by techniques such as BET, which classified as microporous materials samples calcined at 700 ° C, 800 º C and 900 º C and non-porous when annealed at 1000 ° C and 1100 º C, X-ray diffraction (XRD), which identified the formation of two crystalline phases, the Cobalt Ferrite (CoFe2O4) and Cristobalite (SiO2), Scanning Electron Microscopy (SEM) revealed the formation of agglomerates of particles slightly rounded;and Analysis of Colorimetry, temperature of 700 °C, 800 °C and 900 °C showed a brown color and 1000 °C and 1100 °C violet