Comparativa de metodologías de cálculo de faltas en redes eléctricas de baja tensión residenciales e industriales.

[ES]Este trabajo se basa en la aplicación de distintas metodologías (norma europea, método fácil y norma americana) para la obtención de las corrientes de cortocircuito en un sistema eléctrico de baja tensión, de forma que se sepa de antemano el valor de dichas corrientes en cualquier punto del circuito para el correcto dimensionamiento de los dispositivos de protección a emplear.

Value of information in product recovery decisions: A Bayesian approach

There is a widespread recognition of the need for better information sharing and provision to improve the viability of end-of-life (EOL) product recovery operations. The emergence of automated data capture and sharing technologies such as RFID, sensors and networked databases has enhanced the ability to make product information; available to recoverers, which will help them make better decisions regarding the choice of recovery option for EOL products. However, these technologies come with a cost attached to it, and hence the question 'what is its value?' is critical. This paper presents a probabilistic approach to model product recovery decisions and extends the concept of Bayes' factor for quantifying the impact of product information on the effectiveness of these decisions. Further, we provide a quantitative examination of the factors that influence the value of product information, this value depends on three factors: (i) penalties for Type I and Type II errors of judgement regarding product quality; (ii) prevalent uncertainty regarding product quality and (iii) the strength of the information to support/contradict the belief. Furthermore, we show that information is not valuable under all circumstances and derive conditions for achieving a positive value of information. © 2010 Taylor & Francis.

Color centers in Yb : YAG crystals grown by temperature-gradient techniques

Yb: YAG (Yb: Y3Al5O12) crystals have been grown by temperature-gradient techniques (TGT) and their color centers and impurity defects were investigated by means of gamma irradiations and thermal treatment. Two color centers located at 255 and 290 nm were observed in the as-grown TGT-Yb: YAG. Analysis shows that the 255 nm band may be associated with Fe3+ ions. Absorption intensity changes of the 290 nm band after gamma irradiation and thermal treatment indicate that this band may be associated with oxygen-vacancy defects. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

平板偏振膜的角度特性研究

当入射光倾斜入射到平板偏振膜上时，在两种偏振光的反射带边缘处出现P偏振光高透而S偏振光高反的情况．利用F-P结构的膜系设计了偏振膜．随着入射角的增大，S光的带宽、消光比及参考波长线性增大。而膜层中电场强度的最大值和界面处的电场强度均减小，只有P偏振光的变化特性跟布儒斯特角有关．分析膜层的界面特性和膜层中的缺陷分布情况，可得偏振膜P偏振光的阈值随入射角的增大而增大．结果表明。在P光透过率可使用的范围内，入射角越大，消光比越大，场强在膜层中的分布越低，但P偏振光的透过率有所降低．