845 resultados para thread rolling
Resumo:
El crecimiento que ha venido presentando CENIT Transporte y logística de hidrocarburos S.A.S. ha conducido a su área de tecnología a revisar los procesos tecnológicos con los que apoya a todas las áreas de negocio para el logro de la estrategia empresarial. Para poder cumplir con esta promesa de valor hacia la organización, el área de tecnología bajo un marco de trabajo reconocido debe analizar, definir, estructurar e implementar formalmente sus procesos y de esta manera también cumplirá con los lineamientos establecidos por la casa matriz Ecopetrol S.A. COBIT 5-ISACA (2012) como marco de trabajo que integra las mejores practicas a nivel de tecnología, permite ser usado como el estándar que mejor se adecua a la necesidad del área de tecnología para definir e implementar un gobierno de TI en CENIT. Este trabajo propone un modelo para la definición e implementación de procesos de gobierno de tecnologías de la información que cuenta con una herramienta que basada en el nivel de importancia, aporte al foco de análisis y esfuerzo requerido permite de manera automática que los procesos se clasifiquen y prioricen generando las bases para estructurar el plan de trabajo que permitirá de manera organizada lograr la formalización de sus procesos. Este modelo y su herramienta se usaron para definir y clasificar los procesos que permitirán la implementación del gobierno de TI en CENIT. El resultado es que tres (3) de los procesos de COBIT 5.0 que inicialmente ayudarán a implementar formalmente el gobierno de TI, son en su orden APO01, APO02 y EDM01. Adicionalmente este modelo y herramienta propuesta pueden ser usadas para clasificar los procesos de COBIT 5.0 bajo diferentes focos de análisis.
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El presente caso de estudio tiene como objetivo explicar el rol de la cooperación internacional para el desarrollo en Tanzania, Mozambique, Nigeria para la consolidación del liderazgo político internacional de Japón. El interés de realizar esta investigación es la ampliación del conocimiento sobre el uso del poder blando, para alcanzar los objetivos de política exterior japonesa. Por eso, se llevara a cabo una revisión bibliográfica para el análisis de documentos oficiales y artículos académicos para la consolidación de información. A partir de ello, se pretende demostrar que la cooperación al desarrollo es una herramienta de política exterior japonesa para consolidarse como líder, en la medida en que el uso de herramientas propias de la cooperación y el presupuesto destinada a la ejecución de éstas tienen incidencia en los votos de estos Estados africanos para las iniciativas japonesas en las Naciones Unidas.
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Las redes son un importante elemento topológico que tiene poco soporte en el software libre. Hay redes que cuentan con millones de nodos, lo que conlleva la necesidad de manejarlas de forma cuidadosa para optimizar los recursos. Consultando el estado del arte, hemos concluido que existe cierta cantidad de librerías de código abierto disponible, que generalmente emplean un modelo de gestión de los grafos que genera una estructura mallada de objetos en memoria precisando grandes cantidades de memoria y tiempos de puesta en marcha elevados. Estas carencias adquieren especial relevancia cuando se trata de manejar grandes redes. Además las librerías analizadas no suelen ser aptas para procesado multihilo por lo que no pueden usarse en entornos de servidores. Para estos casos hemos puesto en marcha el proyecto IDELabRoute la solución propuesta consiste en una librería genérica de análisis de redes “thread-safe” con gestión dinámica de memoria; para lo cual, se usa una arquitectura modular con gestores de memoria intercambiables, que desde distintas fuentes de almacenamiento persistente (i.e. bases de datos o sistemas de ficheros), maneja grafos de forma dinámica atendiendo a criterios espaciales y/o topológicos. Se trata de una solución de compromiso, puesto que el precio a pagar por la reducción del tamaño de los objetos en memoria es un incremento en el tiempo de respuesta, debido a la gestión de memorias con diversos tiempos de respuesta. Se trata, por tanto, de un sistema de gestión de grafos dinámico que permite manejar grandes modelos de redes de forma escalable, por lo que puede resultar adecuado en entornos con pocos recursos en relación al tamaño total de la red. El primer objetivo práctico del proyecto es proporcionar a la comunidad del GIS libre un servicio WPS para el cálculo de rutas
Resumo:
La autora revisa la ensayística de Alfredo Pareja sobre temas de arte colonial, cultura y literatura. Da cuenta de la evolución de su noción de lo artístico desde 1933, cuando Pareja marca distancia con la generación anterior y con el arielismo vigente, al hacer suya la defensa del realismo social, más adelante, sin embargo, matizaría estos juicios en otros ensayos. Su postura crítica, en términos generales, no defiende la originalidad ni la forma del texto por sí mismas, sino el valor del contenido, el humanismo empieza a ser el hilo conductor de su narrativa e iluminador de su estética. Por otro lado, siente la necesidad de resignificar lo local en su contacto con lo universal, reconociendo el afán de contemporaneidad de su generación, su defensa de lo mestizo está presente en sus reflexiones sobre el barroquismo latinoamericano. Finalmente, resulta interesante que Pareja aproxime dos grandes momentos del arte ecuatoriano: la pintura y escultura colonial de la llamada escuela de Quito, y la propuesta estética de su generación.
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Este ensayo analiza aspectos de la dilatada labor como periodista, crítico literario, narrador de ficción y, sobre todo, la producción poética del ecuatoriano Alejandro Carrión. Señala que su narrativa, desde muy temprano, evidencia el tono satírico que no abandonaría jamás, tanto como su «vocación festiva de la sedición». Destaca su labor como periodista, principalmente con el seudónimo de Juan sin cielo. Menciona algunos aportes de Carrión en tanto crítico literario, recogidos principalmente en la revista Letras del Ecuador. El hilo conductor del ensayo –a ratos nostálgica semblanza– se nutre de una perspectiva inevitable: ciertos rasgos de su personalidad (su experiencia en «romances y serpientes», la vocación de incisivo y mordaz humorista, su «naturaleza confrontacional» y aguda inteligencia), además de sus dotes de narrador satírico y de poeta.
Resumo:
Rhizobium leguminosarum synthesizes polyhydroxybutyrate and glycogen as its main carbon storage compounds. To examine the role of these compounds in bacteroid development and in symbiotic efficiency, single and double mutants of R. legumosarum bv. viciae were made which lack polyhydroxybutyrate synthase (phaC), glycogen synthase (glgA), or both. For comparison, a single phaC mutant also was isolated in a bean-nodulating strain of R. leguminosarum bv. phaseoli. In one large glasshouse trial, the growth of pea plants inoculated with the R. leguminosarum bv. viciae phaC mutant were significantly reduced compared with wild-type-inoculated plants. However, in subsequent glasshouse and growth-room studies, the growth of pea plants inoculated with the mutant were similar to wildtype-inoculated plants. Bean plants were unaffected by the loss of polyhydroxybutyrate biosynthesis in bacteroids. Pea plants nodulated by a glycogen synthase mutants or the glgA/phaC double mutant, grew as well as the wild type in growth-room experiments. Light and electron micrographs revealed that pea nodules infected with the glgA mutant accumulated large amounts of starch in the II/III interzone. This suggests that glycogen may be the dominant carbon storage compound in pea bacteroids. Polyhydroxybutyrate was present in bacteria in the infection thread of pea plants but was broken down during bacteroid formation. In nodules infected with a phaC mutant of R. leguminosarum bv. viciae, there was a drop in the amount of starch in the II/III interzone, where bacteroids form. Therefore, we propose a carbon burst hypothesis for bacteroid formation, where polyhydroxybutyrate accumulated by bacteria is degraded to fuel bacteroid differentiation.
Resumo:
Rhizobium leguminosarum synthesizes polyhydroxybutyrate and glycogen as its main carbon storage compounds. To examine the role of these compounds in bacteroid development and in symbiotic efficiency, single and double mutants of R. legumosarum bv. viciae were made which lack polyhydroxybutyrate synthase (phaC), glycogen synthase (glgA), or both. For comparison, a single phaC mutant also was isolated in a bean-nodulating strain of R. leguminosarum bv. phaseoli. In one large glasshouse trial, the growth of pea plants inoculated with the R. leguminosarum bv. viciae phaC mutant were significantly reduced compared with wild-type-inoculated plants. However, in subsequent glasshouse and growth-room studies, the growth of pea plants inoculated with the mutant were similar to wildtype-inoculated plants. Bean plants were unaffected by the loss of polyhydroxybutyrate biosynthesis in bacteroids. Pea plants nodulated by a glycogen synthase mutants or the glgA/phaC double mutant, grew as well as the wild type in growth-room experiments. Light and electron micrographs revealed that pea nodules infected with the glgA mutant accumulated large amounts of starch in the II/III interzone. This suggests that glycogen may be the dominant carbon storage compound in pea bacteroids. Polyhydroxybutyrate was present in bacteria in the infection thread of pea plants but was broken down during bacteroid formation. In nodules infected with a phaC mutant of R. leguminosarum bv. viciae, there was a drop in the amount of starch in the II/III interzone, where bacteroids form. Therefore, we propose a carbon burst hypothesis for bacteroid formation, where polyhydroxybutyrate accumulated by bacteria is degraded to fuel bacteroid differentiation.
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Most existing crop scheduling models are cultivar specific and are developed using academic resources. As such they rarely meet the particular needs of a grower. A series of protocols have been created to generate effective schedules for a changing product range using data generated on site at a commercial nursery. A screening programme has been developed to help determine a cultivar's photoperiod sensitivity and vernalisation requirement. Experimental conditions were obtained using a cold store facility set to 5degreesC and photoperiod cloches. Eight and 16 hour photoperiod treatments were achieved at low cost by growing plants in cloches of opaque plastic with a motorised rolling screen. Natural light conditions were extended where necessary using a high pressure sodium lamp. Batches of plants were grown according to different schedules based on these treatments. The screening programme found Coreopsis grandiflora 'Flying Saucers' to be a long day plant. Data to form the basis of graphical tracks was taken using variations on commercial schedules. The work provides a nursery based approach to the continuous improvement of crop scheduling practises.
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Nitrogen fixation within legume nodules results from a complex metabolic exchange between bacteria of the family Rhizobiaciae and the plant host. Carbon is supplied to the differentiated bacterial cells, termed bacteroids, in the form of dicarboxylic acids to fuel nitrogen fixation. In exchange, fixed nitrogen is transferred to the plant. Both the bacteroid and the plant-derived peribacteroid membrane tightly regulate the exchange of metabolites. In the bacteroid oxidation of dicarboxylic acids via the TCA cycle occurs in an oxygen-limited environment. This restricts the TCA cycle at key points, such as the 2-oxoglutarate dehydrogenase complex, and requires that inputs of carbon and reductant are balanced with outputs from the TCA cycle. This may be achieved by metabolism through accessory pathways that can remove intermediates, reductant, or ATP from the cycle. These include synthesis of the carbon polymers PHB and glycogen and bypass pathways such as the recently identified 2-oxoglutarate decarboxylase reaction in soybean bacteroids. Recent labeling data have shown that bacteroids synthesize and secrete amino acids, which has led to controversy over the role of amino acids in nodule metabolism. Here we review bacteroid carbon metabolism in detail, evaluate the labeling studies that relate to amino acid metabolism by bacteroids, and place the work in context with the genome sequences of Mesorhizobium loti and Sinorhizobium meliloti. We also consider a wider range of metabolic pathways that are probably of great importance to rhizobia in the rhizosphere, during nodule initiation, infection thread development, and bacteroid development.
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Yellow (CuCN)(2)[(CuCN)(2)(mu-4,4'-bpy)], formed in the hydrothermal reaction of CuCN with 4,4'-bipyridine at 453 K, contains two types of infinite CuCN chains. One set of CuCN chains is linked by 4,4'-bpy ligands to form almost flat sheets of composition [(CuCN)(2)(mu-4,4'-bpy)]. Holes in these sheets are aligned to allow pairs of approximately linear, infinite -(CuCN)- chains to thread through them. The closest interatomic approach between copper atoms in the threading chains and host sheets (similar to2.74 Angstrom) does not appear to represent a significant covalent bond as it leads to only a small distortion of the -(CuCN)- chains from linearity The relationship of this material to the previously determined structures of the host [(CuCN)(2)(mu-4,4'-bpy)] sheets and (CuCN)(3)[(CuCN)(2)(mu-4,4'-bPY)](2), in which these sheets are threaded by single -(CuCN)- chains, is discussed.
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The macrocycle in rotaxane 1 is preferentially hydrogen bonded to the succinamide station in the neutral form, but can be moved to the naphthalimide station by one-electron reduction of the latter. The hydrogen bonding between the amide NH groups of the macrocycle and the C=O groups in the binding stations in the thread was studied with IR spectroscopy in different solvents in both states. In addition, the solvent effect on the vibrational frequencies was analyzed; a correlation with the solvent acceptor number (AN) was observed. The conformational switching upon reduction could be detected by monitoring the hydrogen-bond-induced shifts of the v(CO) frequencies of the C=O groups of the succinamide and the reduced naphthalimide stations. The macrocycle was found to shield the encapsulated station from the solvent: wavenumbers of v(CO) bands of the C=O groups residing inside the macrocycle cavity remain unaffected by the solvent polarity.
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Rolling Contact Fatigue (RCF) is one of the main issues that concern, at least initially, the head of the railway; progressively they can be of very high importance as they can propagate inside the material with the risk of damaging the railway. In this work, two different non-destructive techniques, infrared thermography (IRT) and fibre optics microscopy (FOM), were used in the inspection of railways for the tracing of defects and deterioration signs. In the first instance, two different approaches (dynamic and pulsed thermography) were used, whilst in the case of FOM, microscopic characterisation of the railway heads and classification of the deterioration -- damage on the railways according to the UIC (International Union of Railways) code, took place. Results from both techniques are presented and discussed.
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In the 1990s the Message Passing Interface Forum defined MPI bindings for Fortran, C, and C++. With the success of MPI these relatively conservative languages have continued to dominate in the parallel computing community. There are compelling arguments in favour of more modern languages like Java. These include portability, better runtime error checking, modularity, and multi-threading. But these arguments have not converted many HPC programmers, perhaps due to the scarcity of full-scale scientific Java codes, and the lack of evidence for performance competitive with C or Fortran. This paper tries to redress this situation by porting two scientific applications to Java. Both of these applications are parallelized using our thread-safe Java messaging system—MPJ Express. The first application is the Gadget-2 code, which is a massively parallel structure formation code for cosmological simulations. The second application uses the finite-domain time-difference method for simulations in the area of computational electromagnetics. We evaluate and compare the performance of the Java and C versions of these two scientific applications, and demonstrate that the Java codes can achieve performance comparable with legacy applications written in conventional HPC languages. Copyright © 2009 John Wiley & Sons, Ltd.
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A solution has been found to the long-standing problem of experimental modelling of the interfacial instability in aluminium reduction cells. The idea is to replace the electrolyte overlaying molten aluminium with a mesh of thin rods supplying current down directly into the liquid metal layer. This eliminates electrolysis altogether and all the problems associated with it, such as high temperature, chemical aggressiveness of media, products of electrolysis, the necessity for electrolyte renewal, high power demands, etc. The result is a room temperature, versatile laboratory model which simulates Sele-type, rolling pad interfacial instability. Our new, safe laboratory model enables detailed experimental investigations to test the existing theoretical models for the first time.
Resumo:
Asparagus: A Horticultural Ballet was a live performance and film narrating the rise of capital in the medium of asparagus. The project stemmed from an obscure reference to an art piece of the same name by Waw Pierogi of the band xex. However, the its re-enactment had little to do with the original exploration of the growth and branching patterns of the asparagus plant. Instead, a rigid choreography inspired by Oskar Schlemmer's Triadic Ballet and based on Karl Marx's Capital dictated the movements of six performers in asparagus costumes. Bringing together the organic and the geometric, the ballet investigated the transition from the Fordist assembly line to immaterial labour through a reanimation of modernist abstraction. Being itself the story of abstraction, Capital shows how human relationships are replaced by those between commodities in the joyless grind of endless accumulation. This process results in the transcendent mythical figure of capital, which frames, transfigures and even produces the natural world. Asparagus: A Horticultural Ballet was produced in collaboration with Montreal based band Les Georges Leningrad and commissioned by The Showroom Gallery, London. It was presented live at Conway Hall in London on 6.3.07 and at the Montreal Biennale at SAT on 12.5.07. The performance was accompanied by a film at the Showroom gallery and preceded by a production residency at the Pump House Gallery. The film has subsequently been shown at The Golden Thread Gallery, Bluecoat Liverpool and as part of A-Lot-Ment in Portsmouth. Props from Asparagus: A Horticultural Ballet, were included in The Eagle Document at the Stephen Lawrence Gallery, London.