990 resultados para wedge prism


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Face à l’émergence de la culture numérique, le marché de l’image subit depuis plusieurs années une série de mutations : obsolescence de l’argentique, difficultés des services photos de la presse écrite. Quel écho donnent les artistes, photographes ou écrivains, à cet état de crise avant tout économique du fait photographique? Assisterait-on vraiment à la mort du photographique? Cet article propose de mesurer l’impact de la révolution numérique à travers le prisme des photofictions de Joan Fontcuberta. Rejetant aussi bien les interprétations téléologiques qu’apocalyptiques de cette transition technologique, Joan Fontcuberta prend acte d’une désindexation du fait photographique, et signe une oeuvre résolument photolittéraire.

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A series of nonelectrolytic lanthanide(III) complexes, [ ML 2 Cl 3 ] · 2 H 2 O, where M is lanthanum(III), praseodymium(III), neodymium(III), samarium(III), gadolinium(III), terbium(III), dysprosium(III), and yttrium(III), containing sulfamethoxazole ligand (L) are prepared. The structure and bonding of the ligand are studied by elemental analysis, magnetic susceptibility measurements, IR, 1 H NMR, TG / DTA , X-ray diffraction studies, and electronic spectra of the complexes. The stereochemistry around the metal ions is a monocapped trigonal prism in which four of the coordination sites are occupied by two each from two chelating ligands, sulfonyl oxygen, and nitrogen of the amide group and the remaining three positions are occupied by three chlorines. The ligand and the new complexes were tested in vitro to evaluate their activity against the bacteria Escherichia coli and Staphylococcus aureus.

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We present a complete calculation of the structure of liquid 4He confined to a concave nanoscopic wedge, as a function of the opening angle of the walls. This is achieved within a finite-range density functional formalism. The results here presented, restricted to alkali metal substrates, illustrate the change in meniscus shape from rather broad to narrow wedges on weak and strong alkali adsorbers, and we relate this change to the wetting behavior of helium on the corresponding planar substrate. As the wedge angle is varied, we find a sequence of stable states that, in the case of cesium, undergo one filling and one emptying transition at large and small openings, respectively. A computationally unambiguous criterion to determine the contact angle of 4He on cesium is also proposed.

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The present scientific investigation of the effects of copper, mercury and cadmium has focussed on their effects on two commercially important marine bivalve species, Perna indica (brown mussel) and Donax incarnatus (wedge clam), conspicuous representatives of the tropical intertidal areas. The investigation centred around delineating the cause and effects of heavy metal stress, individually and in combination on these species under laboratory conditions. A clear understanding of the cause and effect can be had only if laboratory experiments are conducted employing sub-lethal concentrations of the above toxicants. Therefore, during the course of the investigation, sub-lethal concentrations of copper, mercury and cadmium were employed to assess the concentration dependent effects on survival, ventilation rate, O:N ratio and tissues. The results obtained are compared with the already available information and partitioned in sections to make a meaningful presentation.The thesis is presented in five chapters comprising INTRODUCTION, ACUTE TOXICITY, VENTILATION RATE, OXYGEN : NITROGEN RATIO and HISTOPATHOLOGY. Each chapter has been divided into various sections such as INTRODUCTION, REVIEW OF LITERATURE, MATERIAL AND METHODS, RESULTS and DISCUSSION

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Das Gewindefurchen ist ein spanloses Fertigungsverfahren zur Herstellung von Innengewinden. Es bietet wesentliche Vorteile gegenüber der spanenden Innengewindeherstellung, wie z.B. keine Notwendigkeit zur Spanentsorgung, höhere Festigkeit der Gewindeflanken und eine erhöhte Prozessgeschwindigkeit. Um die Vorteile des Verfahrens unter wirtschaftlichen und technologischen Aspekten besser auszunutzen, bietet die Weiterentwicklung der Werkzeuggeometrie sowohl im makroskopischen als auch im mikroskopischen Bereich ein enormes Potential, welches nicht nur bezüglich der Standzeit bzw. Standmenge und Prozessgeschwindigkeit, sondern auch hinsichtlich der Qualität der erzeugten Gewinde erschlossen werden sollte. Durch die empirische Untersuchung der technischen und physikalischen Eigenschaften am Gewindefurcher sollen der Anformbereich und die Formkeilgeometrie in Abhängigkeit verschiedener Prozessparameter und Werkstoffe verbessert werden, um optimale Bearbeitungsergebnisse hinsichtlich der hergestellten Gewindefurchen und des auftretenden Verschleißes am Gewindefurcher bzw. Formkeils zu erreichen. Die Basis dieser Untersuchungen bildet ein neuartiger Modellversuch, bei dem modifizierte Gewindefurcher verwendet werden, die derart umgestaltet sind, dass von einem üblichen Gewindefurcher durch Umschleifen nur noch ein einzelner Gewindegang am Werkzeug verbleibt. Dadurch ist es möglich, in einer vergrößerten Vorbohrung mit einem Formkeil die einzelnen Umformstufen beim Gewindefurchen separat zu fertigen, die auftretenden Prozesskräfte während des Eingriffs in das Werkstück zu messen und das Bearbeitungsergebnis im Werkstück und den Verschleiß am Formkeil zu bewerten. Weiterhin wird eine rein theoretische Methode beschrieben, mit der die Berechnung der Umformkraft und darauf basierend der Furchmomente am Formkeil bzw. dem ganzen Gewindefurcher möglich ist. Durch die Kenntnis der berechneten Kräfte und Momente am einzelnen Formkeil bzw. dem Gewindefurcher kann bereits in der Konzeptionsphase eines Gewindefurchers eine Anpassung des Werkszeuges an die jeweiligen Bearbeitungsanforderungen durchgeführt werden, wodurch der Entwurf von Gewindefurchern wesentlich wirtschaftlicher realisierbar ist, als durch rein empirische Herangehensweisen.

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Durante los siglos XVII y XVIII se presentaron varias querellas ante el Tribunal de Justicia Criminal del Nuevo Reino de Granada, en las que se denunciaba que había personas que ejercían los oficios médicos sin tener títulos que los acreditaran como facultativos en las artes curativas. Por ese entonces, se creía que quienes utilizaban yerbas y conjuros como métodos terapéuticos, por lo general mujeres, debían ser juzgadas como yerbateras-envenenadoras, porque no pretendían curar sino matar a quien consumiera sus preparados. El texto establece que los procesos criminales por envenenamiento constituyen un prisma en el que convergen diferentes problemáticas del periodo colonial neogranadino, relacionadas con la salud, los oficios médicos, las enfermedades, las creencias mágico-religiosas, el ideal de mujer en la época, la delincuencia, y las dinámicas de las instituciones españolas, entre otras. De esta manera, se estudió cómo fue la relación entre los aspectos jurídicos, las leyes criminales (dictadas por la Corona) y las conductas “desviadas” (relacionadas con el crimen por envenenamiento) de los habitantes del Nuevo Reino de Granada, entre los siglos XVII y XVIII. Para ello se revistaron desde diferentes perspectivas, varios temas del mundo colonial neogranadino, relacionados con los rumores, la comidilla, los chismes y la importancia de la comunicación hablada en el virreinato; el problema de la honra, como una de las virtudes más sobresalientes de la época y las creencias de la cultura popular con relación al envenenamiento y los diferentes métodos curativos.

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La vida y obra de los personajes de la historia de la ciencia puede ser analizada por los historiadores a través de un prisma formado por artistas subjetivas que corresponden a sus propios pensamientos, percepción e imaginación, lo que conduce a que con frecuencia resultan imágenes distorsionadas que dan origen a mitos. El presente artículo invita al lector a reflexionar sobre las imágenes plasmadas por los historiadores, acerca de algunos protagonistas de la ciencia y de su entorno.

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La propuesta es demostrar cómo el mercado inmobiliario informal en los asentamientos consolidados del Área Metropolitana de Buenos Aires puede ser entendido a partir del prisma de las redes sociales, organizaciones barriales y relaciones familiares de reciprocidad y cómo este mercado modifi ca, a su vez, dichas relaciones sociales, e incluso introduce nuevas reagrupaciones, no exentas de conflictos. 

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Objetivo: Evaluar el efecto sobre presión arterial media (PAM), estancia hospitalaria, mortalidad y perfusión tisular con el uso de vasopresores en niños con choque séptico refractario en la Unidad de Cuidado Intensivo pediátrico de la Fundación CardioInfantil. Materiales y Métodos: Estudio observacional de cohorte retrospectiva en niños de 1 mes a 18 años con choque séptico refractario atendidos de enero 2008 a diciembre 2013 tratados con noradrenalina sola ó vasopresina-noradrenalina. Se excluyeron pacientes con choque de otra etiología, cardiopatías congénitas, diabetes insípida y muerte encefálica. Se estimaron, como medidas de asociación riesgos relativos con sus respectivos intervalos de confianza al 95%.Resultados: Se evaluaron 129 pacientes, de los cuales 51% eran niños, edad promedio 52 meses con una mortalidad global del 34.1%. La PAM inicial en ambos grupos mostró incremento significativo que se mantuvo en las siguientes 3 horas (p<0,005). La mortalidad en el grupo PRISM III de bajo riesgo fue menor con la noradrenalina sola (p<0,005 RR3,7 IC95% 1,16-12,2) pero igual en ambos grupos en los de riesgo moderado según esta escala(p=0,42 RR 0,88 IC95% 0,60-1,30). No se encontraron diferencias estadísticamente significativas en estancia en UCIP (p=0,79) ni hospitalaria total (p=0,96) pero sí mejoría en función hepática (p=0,004)y renal (p<0,005) del grupo de vasopresina-noradrenalina Conclusiones: La asociación vasopresina-noradrenalina mejora la PAM cuando no se han alcanzado metas con un solo vasopresor en pacientes con choque séptico refractario. Se necesitan estudios prospectivos que corroboren estos hallazgos. Palabras claves:Choque séptico refractario, noradrenalina, vasopresina, mortalidad.

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RESUMO:O prisma central desta pesquisa se insere na dimensão da análise da aplicação das Políticas Púbicas educacionais implantadas pelo governo brasileiro e direcionadas à Educação do Campo aos Jovens e Adultos que vivem nas Comunidades Campesinas dos assentamentos da Reforma Agrária. Com vistas a avaliar se a efetivação dessas políticas estão conseguindo propiciar aos nossos camponês, sua permanência no campo, podendo desfrutar de uma vida mais digna para si, sua família e sua comunidade, foi feita a análise de conteúdos das entrevistas realizadas com os alunos, seus pais e seus professores, no intuito de compreender quais são os benefícios da implantação da EJA na comunidade pesquisada. O estudo mostrou que as Políticas Educacionais direcionadas ao Campo, no município de Conceição do Araguaia-PA, na modalidade EJA, têm conseguido ajudar o homem do campo na luta por melhorias na qualidade de vida de suas comunidades e contribuído enquanto elemento formulador da permanência do homem do campo em suas terras, além de se constituir numa ferramenta de conscientização política por se configurar como uma educação diferenciada da encontrada nos centros urbanos, pois suas diretrizes são direcionadas às especificidades da população campesina e tem como ponto de partida as dificuldades vivenciadas por seus alunos. ABSTRACT: The prism of this research is inserted in the dimension of the analysis of the implementation of educational public policy implemented by the Brazilian government and directed the Rural Education, for young people and adults living in agrarian reform settlements. With the aim to value whether the implementation of these policies are able to provide our peasant his stay in the countryside can enjoy a better life for himself, his family and his community, has made the content analysis of interviews with students, their parents and their teachers in order to understand what are the benefits of the implementation of Adult and Young people Education in this pesquised community. The study showed that policies aimed at the educational field, in the municipality of Conceição do Araguaia-PA, in the form Adult and Young People Education, has succeeded in helping the people in the field fighting for improvements in quality of life of their communities and contributed as part formulator of the permanence of the countryside on their land, and from being a tool for political awareness to configure itself as a differentiated education that found in urban centers, because their directives are geared to the specificities of the peasant population and its starting point the difficulties experienced by their students.

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Este artículo explora los discursos del colonialismo y nacionalismo en países y períodos diferentes a través del prisma de género, para comprender las exigencias y supuestos, así como la contingencia y la contradicción que son inherentes a tales proyectos. Se basa en críticos que ofrecen la teoría poscolonial y feminista, en particular, las poderosas advertencias –postuladas a partir de matizados entendimientos de la cultura y el poder– acerca de cómo el género y la sexualidad modularon las formaciones de la Colonia y el imperio. Un enfoque particular en la representación cultural, por parte de las élites, de la nación en India y México, permite desmitificar a la nación y descubrir los lazos latentes pero fuertes que vinculan el pasado colonial con la nación nacional (¿poscolonial?).

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France is known for being a champion of individual rights as well as for its overt hostility to any form of group rights. Linguistic pluralism in the public sphere is rejected for fear of babelization and Balkanization of the country. Over recent decades the Conseil Constitutionnel (CC) has, together with the Conseil d’État, remained arguably the strongest defender of this Jacobin ideal in France. In this article, I will discuss the role of France’s restrictive language policy through the prism of the CC’s jurisprudence. Overall, I will argue that the CC made reference to the (Jacobin) state-nation concept, a concept that is discussed in the first part of the paper, in order to fight the revival of regional languages in France over recent decades. The clause making French the official language in 1992 was functional to this policy. The intriguing aspect is that in France the CC managed to standardise France’s policy vis-à-vis regional and minority languages through its jurisprudence; an issue discussed in the second part of the paper. But in those regions with a stronger tradition of identity, particularly in the French overseas territories, the third part of the paper argues, normative reality has increasingly become under pressure. Therefore, a discrepancy between the ‘law in courts’ and the compliance with these decisions (‘law in action’) has been emerging over recent years. Amid some signs of opening of France to minorities, this contradiction delineates a trend that might well continue in future.

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Although numerous field studies have evaluated flow and transport processes in salt marsh channels, the overall role of channels in delivering and removing material from salt marsh platforms is still poorly characterised. In this paper, we consider this issue based on a numerical hydrodynamic model for a prototype marsh system and on a field survey of the cross-sectional geometry of a marsh channel network. Results of the numerical simulations indicate that the channel transfers approximately three times the volume of water that would be estimated from mass balance considerations alone. Marsh platform roughness exerts a significant influence on the partitioning of discharge between the channel and the marsh platform edge, alters flow patterns on the marsh platform due to its effects on channel-to-platform transfer and also controls the timing of peak discharge relative to marsh-edge overtopping. Although peak channel discharges and velocities are associated with the flood tide and marsh inundation, a larger volume of water is transferred by the channel during ebb flows, a portion of which transfer takes place after the tidal height is below the marsh platform. Detailed surveys of the marsh channels crossing a series of transects at Upper Stiffkey Marsh, north Norfolk, England, show that the total channel cross-sectional area increases linearly with catchment area in the inner part of the marsh, which is consistent with the increase in shoreward tidal prism removed by the channels. Toward the marsh edge, however, a deficit in the total cross-sectional area develops, suggesting that discharge partitioning between the marsh channels and the marsh platform edge may also be expressed in the morphology of marsh channel systems.

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Mostly because of a lack of observations, fundamental aspects of the St. Lawrence Estuary's wintertime response to forcing remain poorly understood. The results of a field campaign over the winter of 2002/03 in the estuary are presented. The response of the system to tidal forcing is assessed through the use of harmonic analyses of temperature, salinity, sea level, and current observations. The analyses confirm previous evidence for the presence of semidiurnal internal tides, albeit at greater depths than previously observed for ice-free months. The low-frequency tidal streams were found to be mostly baroclinic in character and to produce an important neap tide intensification of the estuarine circulation. Despite stronger atmospheric momentum forcing in winter, the response is found to be less coherent with the winds than seen in previous studies of ice-free months. The tidal residuals show the cold intermediate layer in the estuary is renewed rapidly ( 14 days) in late March by the advection of a wedge of near-freezing waters from the Gulf of St. Lawrence. In situ processes appeared to play a lesser role in the renewal of this layer. In particular, significant wintertime deepening of the estuarine surface mixed layer was prevented by surface stability, which remained high throughout the winter. The observations also suggest that the bottom circulation was intensified during winter, with the intrusion in the deep layer of relatively warm Atlantic waters, such that the 3 C isotherm rose from below 150 m to near 60 m.