Failure mode prediction and energy forecasting of PV plants to assist dynamic maintenance tasks by ANN based models

In the field of renewable energy, reliability analysis techniques combining the operating time of the system with the observation of operational and environmental conditions, are gaining importance over time. In this paper, reliability models are adapted to incorporate monitoring data on operating assets, as well as information on their environmental conditions, in their calculations. To that end, a logical decision tool based on two artificial neural networks models is presented. This tool allows updating assets reliability analysis according to changes in operational and/or environmental conditions. The proposed tool could easily be automated within a supervisory control and data acquisition system, where reference values and corresponding warnings and alarms could be now dynamically generated using the tool. Thanks to this capability, on-line diagnosis and/or potential asset degradation prediction can be certainly improved. Reliability models in the tool presented are developed according to the available amount of failure data and are used for early detection of degradation in energy production due to power inverter and solar trackers functional failures. Another capability of the tool presented in the paper is to assess the economic risk associated with the system under existing conditions and for a certain period of time. This information can then also be used to trigger preventive maintenance activities

El Hospital de Niños más antiguo de América

Considering the history of medicine, pediatrics is relatively a recent discipline and so are the institutions devoted to it. The “Spedale degli Innocenti” (Florence, 1419) was the fi rst institution devoted to child care; and is not by chance that it was an orphanage, because the “hospital” concept was then more related to hosting and careing than to health. It was in the 19th century when the pediatric hospitals, as we know them today, appear in Europe (L\u27Hôpital Des Enfants-Malades, Paris, 1802) and North America (Children\u27s Hospital of Philadelphia, 1855); surprisingly “Casa Cuna” (Hospital de Niños Pedro de Elizalde, Buenos Aires, 1779) was already there, witnessing the foundation of both institutionsConsiderando la historia de la medicina, la pediatría es relativamente reciente, al igual que las instituciones donde ésta se desarrolla. El “Spedale degli Innocenti” (Florencia, 1419) fue la primera institución dedicada a los niños; y no es casualidad que se tratara de un orfanato, ya que el concepto de “hospital” estaba fundamentalmente relacionado con hospedar y dar protección. Recién a partir del siglo XIX comienzan a surgir los hospitales pediátricos en Europa (L\u27Hôpital Des Enfants-Malades, Paris, 1802) y América del Norte (Children\u27s Hospital of Philadelphia, 1855); signifi cativamente la “Casa Cuna” (Hospital de Niños Pedro de Elizalde, Buenos Aires, 1779) estaba ya funcionando y asistió a la creación de ambas instituciones

El universo poético de Claudio Rodríguez

Tesis de la Universidad Complutense de Madrid, Facultad de Filología, Departamento de Filología Española II, leída el 16-04-1999Depto. de Literaturas Hispánicas y BibliografíaFac. de FilologíaTRUEpu