Improvement of sensitivity and refractive-index changes in LiNbO3 : Ce : Cu crystals with UV light

A nonvolatile recording scheme is proposed using LiNbO3:Ce:Cu crystals and modulated UV light to record gratings simultaneously in two centres and using red light to bleach the grating in the shallow centre to realize persistent photorefractive holographic storage. Compared with the normal UV-sensitized nonvolatile holographic system, the amplitude of refractive-index changes is greatly increased and the recording sensitivity is significantly enhanced by recording with UV light in the LiNbO3:Ce:Cu crystals. Based on jointly solving the two-centre material equations and the coupled-wave equations, temporal evolutions of the photorefractive grating and the diffraction effciency are effectively described and numerically analysed. Roles of doping levels and recording-beam intensity are discussed in detail. Theoretical results confirm and predict experimental results.

Composite second-order performance improvement in optical fibre CATV transmission system using chirped fibre grating

Theoretically, we analyse the dispersion compensation characteristics of the chirped fibre grating (CFG) in an optical fibre cable television (CATV) system and obtain the analytic expression of the composite second-order (CSO) distortion using the time-domain form of the field envelope wave equation. The obtained result is in good agreement with the numerical simulation result. Experimentally, we verify the result by making use of the tunable characteristics of CFG to change the dispersion compensation amount and obtain an optimal CSO performance in a 125km fibre transmission link. Both the theoretical and experimental results show that the CSO performance can be improved by properly choosing the dispersion compensation amount for a certain fibre transmission link.

Sensitivity improvement by UV-light recording in LiNbO3 : Ce : Cu crystals

Modulated UV light is used to increase the sensitivity of the two-centre holographic recording. Inherent mechanisms of nonvolatile holographic recording in oxidized and reduced crystals are numerically analysed based on solving the two-centre material equations modilied for UV-Iight recording. Experiments verification is performed with an oxidized crystal and a reduced crystal, and the role of UV intensity on the sensitivity is presented.

Improvement in refractive-index change in LiNbO3 : Ce : Cu by applying an external electric field

By jointly solving two-centre material equations with a nonzero external electric field and coupled-wave equations, we have numerically studied the dependence of the non-volatile holographic recording in LiNbO3:Ce:Cu crystals on the external electric field. The dominative photovoltaic effect of the non-volatile holographic recording in doubly doped LiNbO3 crystals is directly verified. And an external electric field that is applied in the positive direction along the c-axis (or a large one in the negative direction of the c-axis) in the recording phase and another one that is applied in the negative direction of the c-axis in the fixing phase are both proved to benefit strong photorefractive performances. Experimental verifications are given with a small electric field applied externally.

Refractive-index change and sensitivity improvement in holographic recording in LiNbO3:Ce:Cu crystals with green light

Nonvolatile holographic recording is performed with green light in LiNbO3:Ce:Cu crystals. The refractive-index change and the recording sensitivity are times better than those obtained by recording with red light, and higher optical fixing efficiency is obtained. Correspondingly, theoretical investigations are given.

Teaching Change: Information Literacy Collaboration at Texas A&M University at Galveston

While college students use a wide array of technologies to access information, their skills at determining what is relevant, in a university setting and in life, are poor. Many of these skills have to be taught in college courses. Instruction must be performed by a collaborative team using technologies that effectively reach students. This team must be ready to go into the classroom when needed and be able to address the problem whenever the student needs assistance. The results will be better writing and better research skills that will not only benefit the faculty but will lead to lifelong learning.

Teaching Students to Evaluate E-Reference Sources with Moodle Forums

This presentation will describe the use of online forums in Moodle, a course management system, to teach students to evaluate both print and electronic reference sources. For two semesters I have created an online forum called the Fishing Hole Scouting Report for an in-class exercise. Students are given 2-3 background questions and told to find the answers using both a library-approved reference source and Wikipedia. Students then evaluate the reference source for effectiveness and ease of use, compared to Wikipedia, and post their comments in the forum to share with the class. I will highlight the educational benefits of using Moodle forums for this purpose and discuss best practices for selecting the most effective sources and questions.

Initiatives for the improvement of continuous management training

[EN] Purpose. This work aims to present, from the company viewpoint, a structured account of management proposals and practices directed toward improving the intensity and effectiveness of continuous management training (CMT). Design/methodology/approach. The article takes as its main theoretical referents the Theory of Human Capital, the Resource-Based Vision and the contributions made via the new institutional economy with regard to the problems of information asymmetry between companies, employees and training providers and completes the proposals that derive from this theoretical approach. To do this, experience-based contributions are collected from a selection of company training and HR managers from twelve Basque companies characterised by their strong investment in management training. The methodology used was qualitative and obtained by different qualitative techniques: Focus Groups, Nominal Groups and the Delphi Method, which make up the so-called Hybrid Delphi. Findings and implications. The proposals are aimed at the main agents in training activity: training providers, associations and public agents engaged in management training and, particularly, companies themselves. The initiatives seek above all to increase training market transparency, to improve mutual commitments between companies and managers, and to link training and development with culture and strategic management, so that firms make optimal investment in management training. Originality/value. The methodology used is original, and the contributions are consistent with the theory, have a proven practical utility, and are presented in a hierarchy, which facilitates decision making.

Beam quality improvement of laser diode array by using off-axis external cavity

A novel off-axis external cavity is designed for laser diode array to improve the beam quality. In this external cavity, a circle aperture with variable size is used as a spatial filter. The diameter of aperture is optimized to 1.2mm and the off-axis angle of external cavity is optimized at 2.6 deg. In the optimal case, the beam parameter product (BPP) of laser diode array is reduced to 121 mm. mrad from 1050 mm. mrad with external cavity optical efficiency of 81%. (C) 2007 Optical Society of America.

Programa Bairro-Escola de Nova Iguaçu: diretrizes e caracterísiticas desta política educacional na gestão e organização curricular da Rede Municipal de Ensino

Esta pesquisa é fundamentada e metodologicamente construída objetivando descrever e analisar o que e como é o Programa Bairro-Escola de Nova Iguaçu, implementado como política educacional, em 2006, para organização curricular da Rede Municipal de Ensino. O foco deste estudo qualitativo está centrado na identificação das principais diretrizes e características produzidas por essa política curricular no/para o desenvolvimento da gestão democrática e na melhoria da prática educativa. Para tanto, a metodologia utilizada para a elaboração deste trabalho foi a abordagem qualitativa, a investigação teórica de eixos temáticos e o estudo de caso do significado do Programa Bairro-Escola para os sujeitos que o vivenciam em Nova Iguaçu, abordando especificamente quais são as principais características que o Programa tem produzido, até então, na gestão macro e micro educacional, na prática educativa e na relação entre ambas as práticas, sob a ótica dos sujeitos que o vivenciam no seu cotidiano de desenvolvimento. Para tanto, este estudo de caso de cunho descritivo-analítico utilizou como campo de investigação duas escolas municipais (situadas em bairros geograficamente distantes) como amostragem e a Secretaria Municipal de Educação de Nova Iguaçu para a obtenção, por meio de entrevistas semiestruturadas (realizadas no segundo semestre de 2011), de informações que "respondessem" aos objetivos desta pesquisa. No entanto, os sujeitos escolhidos para serem entrevistados foram: (um) representante da Secretaria Municipal de Educação de Nova Iguaçu, (dois) diretores, (dois) coordenadores, (dois) orientadores, (dois) professores, (dois) estagiários, (dois) agentes comunitários, (dois) pais de alunos e (dois) alunos, os quais relataram nas entrevistas que o Programa Bairro-Escola iguaçuano, apesar de ser uma política educacional ainda recente, tem contribuído para a melhoria da prática educativa, na medida em que as oportunidades educativas foram ampliadas com a implantação do Horário Integral através das oficinas fixas de aprendizagem, esporte, cultura, informática, entre outras experiências socioeducativas desenvolvidas no âmbito escolar ou em ambientes parceiros nas comunidades do entorno das escolas. E na gestão educacional através da conquista da implementação do conselho escolar, o qual tem possibilitado uma gestão mais participativa e mais autônoma nas escolas. Mas expuseram também que, para um "melhor rendimento", o Bairro-Escola, aqui, ainda carece de variados recursos infraestruturais (recursos de natureza física, humana ou pedagógica) e de mais estratégias que dinamizem a gestão mais participativa, o envolvimento comunitário e o reconhecimento do Programa.