Some applications such as radio astronomy and deep space communications require very sensitive receivers. This dissertation deals with the cryogenic technology applied to the microwave engineering and focuses on the design of very low noise amplifiers both in hybrid (MIC)…

Eighty years after the discovery of penicillin, the interest of this ß-lactam antibiotic at industrial level is still remarkable. Despite the good background knowledge, little is known on how Penicillin chrysogenum became a good penicillin overproducer, and much of the…

Resource management and performance models constitute important aspects for parallel applications' performance analysis and tuning. Defining performance models associated with the application structure has been proven useful for implementing dynamic tuning tools. However, for extending this strategy to complex pplications…

Understanding how materials deform and break is a subject of critical importance in industry. At the same time, it requires from the knowledge of the basic processes governing the phenomenon and hence, fundamental physics research is a must. The presence…

El objetivo de esta tesis es determinar los patrones de variabilidad espacio-temporal que siguen las comunidades de macroinvertebrados en los ríos de Cantabria, aplicando este conocimiento a los procedimientos de evaluación del estado ecológico de los ecosistemas fluviales Cantábricos. La…

From the earliest hardware and software days to the internet era, complexity of computer systems has been something computer scientists, engineers, and programmers have had to deal with. Important fields of research and technology have originated, developed, or matured as…

Since Marconi succeeded in carrying out the first wireless transmission in 1894, experimental research has been always linked with wireless communications. Today, most wireless communications research relies only on computer simulations. Although computer simulations are necessary and recommendable for wireless…

La problemática de la Gestión del Conocimiento es aún muy reciente en el campo y en el dominio de la investigación económica pese al hecho de que el avance científico y tecnológico se mueve de forma más rápida que la…

El estudio de la pobreza ha sido abordado desde diferentes disciplinas, No obstante, ni el problema de la distribución espacial de la pobreza ni el análisis de sus variaciones ha tenido un interés significativo en las ciencias sociales. El principal…

El presente estudio trata de la obtención de diferentes tipos de representaciones de la estructura cognitiva de los alumnos en lo referente a los conceptos asociados al estudio de la Trigonometría, de modo que se identifiquen y comparen los conceptos…