9 resultados para life conditions

em Universidad Politécnica de Madrid


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El desarrollo como política de las naciones marca el período de la postguerra, que en América Latina se concreta en múltiples programas de Desarrollo Rural. El modelo inicial de crecimiento económico se va enriqueciendo con visiones centradas en el ser humano y sus múltiples concepciones de desarrollo. En este entender el desarrollo desde la diversidad cultural y antropológica de los pueblos de América Latina, surge la comunicación radiofónica como camino común para la persuasión, socialización y apropiación colectiva de conocimientos y ámbito participativo para consensuar objetivos y acordar actividades. El activismo de los años setenta y ochenta produjo un número considerable de experiencias. La mayoría de ellas han llegado hasta nuestros días, pero el giro tomado por las sociedades digitalizadas y las prioridades medioambientales han dado un nuevo rostro a aquellas primeras experiencias centradas en el desarrollo rural endógeno. Este estudio investiga el complejo práctico-teórico que integra comunicación y desarrollo en contextos territoriales interculturales con población marginal y aplicación de políticas de desarrollo rural. En el capítulo I se recogen las modalidades de cómo se ha aplicado la comunicación en programas de desarrollo, para profundizar en el concepto de comunicación para el desarrollo, conocer sus actores y resultados, y concluir que el desarrollo “con rostro humano” se hace con personas no con políticas oficiales. El capítulo II presenta a los Pueblos Indígenas de la Sierra Ecuatoriana como actores de su proceso de desarrollo hacia el Sumak Kawsay. Los temas tratados en este capítulo muestran los valores y capacidades de las comunidades indígenas de la Sierra Ecuatoriana para la autogestión de su desarrollo, y deja constancia y denuncia de la lectura negativa que se ha venido haciendo de su cosmovisión. Se encuentra respuesta conceptual y metodológica en el Workng With People para optimizar aportes culturales de los Pueblos Indígenas al proceso comunicacional y participativo para mejorar las condiciones de vida y lograr mayores espacios de autonomía y libertad El conocimiento que explica la realidad sin cambiarla no tiene sentido para los pobres. La realidad requiere ser comprendida para construir el conocimiento que la explique y la cambie: ese es el aporte del modelo conocimiento/acción que se presenta en el capítulo III. En este capítulo se exponen metodologías abiertas a la creatividad y flexibles que responden a los principios del modelo conocimiento/acción. La comunicación para el desarrollo se abre a todas ellas como ágora pluricultural que requiere un lenguaje común que se construye desde el aprendizaje social. Los conceptos expuestos en el capítulo III se vinculan en una propuesta metodológica que integra el conocimiento y la acción con los principios del Working With People, propuesta que se expone en el capítulo IV. El modelo del Proyecto de Comunicación para el Desarrollo junta en un modelo de comunicación popular y prácticas liberadoras con métodos cognitivos de la realidad para planificar el cambio desde la población y con la población. Finalmente, el capítulo V recoge la experiencia de la Casa Campesina Cayambe ejecutora del Proyecto de Comunicación para el Desarrollo en la adaptación ejecutada con Radio Mensaje. La riqueza de la experiencia tiende a escaparse de los límites conceptuales y los esquemas dejan espacios de vida ignotos; pero los conceptos y esquemas constituyen el camino para que la experiencia pase a ser objeto conocido y conocimiento socializado. El Proyecto de Comunicación para el Desarrollo es resultado de un proceso de desarrollo construido desde la acción de la Casa Campesina Cayambe durante 25 años en Cayambe. En el capítulo V se describe el contexto del territorio de Cayambe, la identidad de la Casa Campesina Cayambe y de Radio Mensaje, y termina describiendo los logros de 25 años trabajando con la gente. El estudio concluye que la comunicación participativa, como ámbito de aprendizaje social aplicado en procesos de desarrollo rural, integra el conocimiento/acción e incorpora nuevos conocimientos en la población con los que se desarrollan competencias locales para planificar el desarrollo endógeno con flexibilidad y de abajo-arriba. La Figura 0-1 grafica los elementos bases sobre los que se construye el proceso de desarrollo. ABSTRACT Development as a policy of nations marks the postwar period which created several Rural Development Programs in Latin America. The initial model of economic growth was enriched with approaches focused on human beings and their multiple conceptions of development. In this regard, the development from cultural and anthropological diversity in Latin America, radio communication emerges as a common means for persuasion, socialization and collective appropriation of knowledge and scope for participation in order to agree on objectives and activities. Activism of the seventies and eighties generated a considerable number of experiences, most of which are present today. However, a turn taken by digitalized societies and environmental priorities has given those first experiences which focused on endogenous rural development a new face. This study researches the theoretical-practical status that integrates communication and development in intercultural contexts with marginal population and the use of rural development policies. Chapter one shows the modalities of how communication in development programs have been applied to deepen the concept of communication for development, to know those who are involved and its findings, and conclude that development “with a human face” is done with people not with official policies. Chapter two presents Indigenous communities in the Ecuadorian highlands, as people involved in their development process towards Sumak Kawsay. The topics in this chapter show the values and capacities indigenous communities in the Ecuadorian highlands have to self-manage their development, and proves, as well as denounces, that their cosmovision has been negatively perceived. A conceptual and methodological response is found in Working With People in order to optimize cultural contributions of Indigenous People to the communicational and participative process to improve life conditions and have greater spaces of autonomy and freedom. Knowledge which explains reality without changing it does not make any sense for the poor. Reality need to be understood in order to build the knowledge that will explain it and change it: that is the contribution of the knowledge/action model presented in chapter three. This chapter presents open methodologies to creativity which are flexible to respond to the principles of the knowledge/action model. Communication for development is open to all of them as pluricultural agora which requires a common language that is built from social learning. The concepts presented in chapter three are linked in a methodological proposal which integrates knowledge and action with principles of Working With People, proposal which is presented chapter four. The model of the Communication for Development Project includes popular communication elements and liberating practices with cognitive methods of reality to plan change from the population and with the population. Finally, chapter five presents the experiences from the Cayambe Country House, which conducted the Communication for Development Project in the adaptation implemented with Radio Mensaje. The wealth of experience tends to scape from the conceptual limits and the schemes leave gaps of unexplored life; but the concepts and schemes constitute the way so that experience becomes a known object and socialized knowledge. The Communication for Development Project is the result of a development process built from the actions of the Cayambe Country House during 25 years in Cayambe. Chapter five describes the context of Cayambe, the identity of the Cayambe Country House and Radio Mensaje, and the achievements after 25 years of working with its people. The study concludes that participatory communication, as an area of social learning applied to rural development processes, integrates knowledge/action and incorporates new knowledge in communities to develop local competencies to plan endogenous development with flexibility and from the bottom – up.

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Adding Zn improves crop growth, increases seed yield and also positively affects nutritional quality. After Zn fertilization, there is normally a period of several years in which residual effects provide an adequate supply of Zn to successive crops. Immediately after the application of Zn sources water-soluble Zn slowly but continually decreases. Various factors, including time and moisture conditions, affect the aging process and modify the solubility of the metal in soil and therefore its availability. In previous experiments, we studied the residual effect of synthetic chelates, obtained that the amounts of potentially available Zn decreased in the second cropping year due to aging processes. The present study was undertaken to verify variations in the residual effects of applying four different synthetic Zn sources

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Concentrator photovoltaic is an emergent technology that may be a good economical and efficient alternative for the generation of electricity at a competitive cost. However, the reliability of these new solar cells and systems is still an open issue due to the high-irradiation level they are subjected to as well as the electrical and thermal stresses that they are expected to endure. To evaluate the reliability in a short period of time, accelerated aging tests are essential. Thermal aging tests for concentrator photovoltaic solar cells and systems under illumination are not available because no technical solution to the problem of reaching the working concentration inside a climatic chamber has been available. This work presents an automatic instrumentation system that overcomes the aforementioned limitation. Working conditions have been simulated by forward biasing the solar cells to the current they would handle at the working concentration (in this case, 700 and 1050 times the irradiance at one standard sun). The instrumentation system has been deployed for more than 10 000 h in a thermal aging test for III-V concentrator solar cells, in which the generated power evolution at different temperatures has been monitored. As a result of this test, the acceleration factor has been calculated, thus allowing for the degradation evolution at any temperature in addition to normal working conditions to be obtained.

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Profiting by the increasing availability of laser sources delivering intensities above 109 W/cm2 with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is being consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals and is being developed as a practical process amenable to production engineering. The main acknowledged advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Following a short description of the theoretical/computational and experimental methods developed by the authors for the predictive assessment and experimental implementation of LSP treatments, experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (specifically Al and Ti alloys) under different LSP irradiation conditions are presented. In particular, the analysis of the residual stress profiles obtained under different irradiation parameters and the evaluation of the corresponding induced surface properties as roughness and wear resistance are presented.

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Profiting by the increasing availability of laser sources delivering intensities above 10 9 W/cm 2 with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is being consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals and is being developed as a practical process amenable to production engineering. The main acknowledged advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Following a short description of the theoretical/computational and experimental methods developed by the authors for the predictive assessment and experimental implementation of LSP treatments, experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (specifically steels and Al and Ti alloys) under different LSP irradiation conditions are presented

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BACKGROUND: The immediate lethality caused by spinosad has been widely studied on Spodoptera exigua (H ¿ ubner). However, long-term effects can also provide valuable information on insecticide toxic action. Here, the persistence of spinosad on Capsicum annuum L. foliage and the lethal and sublethal effects of greenhouse-aged foliar residues of this insecticide on third instars of S. exigua are reported. RESULTS: Foliage was collected at 0, 3, 5, 10, 20, 30, 40 and 50 days after application, and spinosad residues were measured. Residues decreased over time according to first-order kinetics. The average rate constant and half-life of disappearance were 4.44×10?3 and156 daysand5.80×10?3 and120 days for60and120 mg L?1 respectively. Larval mortalitygradually decreased, corresponding to the residues, but was still appreciable (35 and 65% for 60 and 120 mg L?1 respectively) when the larvae were fed with foliage collected 50 days after treatment. Subsequently, pupal development was reduced and varied between 20 and 60% and between 21 and 41% for 60 and 120 mg L?1, respectively, in all ages of leaf residues that were bioassayed. At all time points, the consumption rate by the larvae was reduced between 62 and 84% for both concentrations that were bioassayed. CONCLUSION: It is concluded that, under the present greenhouse conditions, the degradation of spinosad was slower than that reported by other authors in the field, and, because of that, its residues could cause lethal and sublethal effects to S. exigua larvae.

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A quantitative temperature accelerated life test on sixty GaInP/GaInAs/Ge triple-junction commercial concentrator solar cells is being carried out. The final objective of this experiment is to evaluate the reliability, warranty period, and failure mechanism of high concentration solar cells in a moderate period of time. The acceleration of the degradation is realized by subjecting the solar cells at temperatures markedly higher than the nominal working temperature under a concentrator Three experiments at three different temperatures are necessary in order to obtain the acceleration factor which relates the time at the stress level with the time at nominal working conditions. . However, up to now only the test at the highest temperature has finished. Therefore, we can not provide complete reliability information but we have analyzed the life data and the failure mode of the solar cells inside the climatic chamber at the highest temperature. The failures have been all of them catastrophic. In fact, the solar cells have turned into short circuits. We have fitted the failure distribution to a two parameters Weibull function. The failures are wear-out type. We have observed that the busbar and the surrounding fingers are completely deteriorate

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Nowadays, the projects LIFE (Laser Inertial Fusion Energy) in USA and HiPER (High Power Laser Energy Research) in Europe are the most advanced ones to demonstrate laser fusion energy viability. One of the main points of concern to properly achieve ignition is the performance of the final optics (lenses) under the severe irradiation conditions that take place in fusion facilities. In this paper, we calculate the radiation fluxes and doses as well as the radiation-induced temperature enhancement and colour centre formation in final lenses assuming realistic geometrical configurations for HiPER and LIFE. On these bases, the mechanical stresses generated by the established temperature gradients are evaluated showing that from a mechanical point of view lenses only fulfil specifications if ions resulting from the imploding target are mitigated. The absorption coefficient of the lenses is calculated during reactor startup and steady-state operation. The obtained results reveal the necessity of new solutions to tackle ignition problems during the startup process for HiPER. Finally, we evaluate the effect of temperature gradients on focal length changes and lens surface deformations. In summary, we discuss the capabilities and weak points of silica lenses and propose alternatives to overcome predictable problems

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Laser shock processing (LSP) is being increasingly applied as an effective technology for the improvement of metallic materials mechanical and surface properties in different types of components as a means of enhancement of their corrosion and fatigue life behavior. As reported in previous contributions by the authors, a main effect resulting from the application of the LSP technique consists on the generation of relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Additional results accomplished by the authors in the line of practical development of the LSP technique at an experimental level (aiming its integral assessment from an interrelated theoretical and experimental point of view) are presented in this paper. Concretely, follow-on experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (especially Al and Ti alloys characteristic of high reliability components in the aerospace, nuclear and biomedical sectors) under different LSP irradiation conditions are presented along with a practical correlated analysis on the protective character of the residual stress profiles obtained under different irradiation strategies. Additional remarks on the improved character of the LSP technique over the traditional “shot peening” technique in what concerns depth of induced compressive residual stresses fields are also made through the paper