983 resultados para 159-958


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Nanostructured tungsten carbides were synthesized, for the first time, with a size distribution of 5-12 nm on ultrahigh surface area carbon material, by carbothermal hydrogen reduction (CHR) at 850degreesC and metal Ni promoted CHR at 650 degreesC.

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A titanium-based perovskite-type oxide was synthesized by an improved method of combining EDTA acid and citric acid complexes. High structural stability, good sintering ability, and relatively high oxygen permeation flux were obtained simultaneously for disks synthesized from this ceramic oxide. (C) 2002 Elsevier Science B.V All rights reserved.

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A method has been developed for determining of heavy metal ions by field-amplified sample injection capillary electrophoresis with contactless conductivity detection. The effects of the 2-N-morpholinoethanesulfonic acid/histidine (MES/His) concentration in the sample matrix, the injection time and organic additives on the enrichment factor were studied. The results showed that MES/His with a low concentration in the sample matrix, an increase of the injection time and the addition of acetonitrile improved the enrichment factor. Four heavy metal ions (Zn2+, Co2+, Cu2+ and Ni2+) were dissolved in deionized water, separated in a 10 mM MES/His running buffer at pH 4.9 and detected by contactless conductivity detection. The detection sensitivity was enhanced by about three orders of magnitude with respect to the non-stacking injection mode. The limits of detection were in the range from 5 nM (Zn2+) to 30 nM (Cu2+). The method has been used to determine heavy metal ions in tap water.

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Implementation of EHEA, among others, motivates a transforming process in universities and promotes changes in the professor’s tasks. This events, promote changes to which the university professor has to adapt, meaning this to acquire and to develop new competencies to respond correctly to new professional tasks that are demanded. To design training plans in accordance to the new training needs, and to establish referents in accreditation, selection and promotion protocols appear to be necessary to define the new competences profile professors have to face in order to develop their teaching, research and management tasks suitably, and according to their professional settings and professional development stage. A qualitative research was developed to define the emerging competence profile. Quantitative and qualitative methods were mixed as well as different tools (questionnaires, interviews and focus groups) and sources (faculty, experts and students). This article only shows the results obtained from professors (expert and novice) in the 4 research competencies analyzed (design, development and assessment of projects; organization and management of scientific events; development of scientific material; communication and dissemination of scientific knowledges) and the most significant dates of the 30 competency units that compose them. Results show significant differences of self-perception of current competency domain level between novice faculty and expert faculty. These results help us to establish the priority training areas to the faculty according to their professional development stage.

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L’étude présente l’élaboration du premier outil d’évaluation normalisée du langage destiné aux enfants francophones d’âge préscolaire des pays africains qui se caractérisent par l’absence de services publics en orthophonie et la méconnaissance des retards de langage. En s’inspirant des techniques psychométriques langagières utilisées en Amérique du nord et en se basant sur les théories d’acquisition du langage, on a construit un outil appelé Batterie de tests de dépistage approfondi (BATEDA) qui compte onze tests répartis en trois sous-batteries évaluant respectivement l’intégrité des modalités de transmission du langage (BATEM), les composantes langagières (BATEL) et la mémoire verbale (TMV). A partir d’un échantillon de 159 enfants camerounais francophones, on a normalisé la batterie suivant la cote z et les rangs en centile. Les tests présentent une fiabilité inter-juge et intra-juge (p<0,05), une cohérence interne globale d’environ 96% (α de Cronbach=0,958) et une validité prédictive de la réussite scolaire des enfants (r=0,700). Les stratégies d’application de la BATEDA visent à favoriser la pratique du dépistage systématique et la prise en charge des retards de langage au Cameroun, en mettant à contribution les enseignants et les parents comme principaux intervenants. Les implications de cette étude sont de trois ordres : (1) une meilleure connaissance des difficultés langagières, la revalorisation des personnes atteintes et une attitude de vigilance sociale; (2) l’instauration de la pratique de dépistage précoce favorable à l’intervention; (3) une potentielle diminution du taux d’exclusion et d’abandon scolaire d’enfants présentant des retards langagiers à travers un enseignement ciblé en leur faveur.

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La tesis devela la connotación sistemática y multicausal de lo que a través de la investigación se denomina como "Procesos de Territorialización de la Inseguridad Ciudadana". Mediante un estudio de caso, se pone en evidencia la apropiación y captura sostenida en el tiempo de fenómenos como la inseguridad y la criminalidad, sobre determinadas zonas o barrios urbanos que por sus características socioeconómicas, políticas, geográficas, culturales, laborales y de mercado de quienes los habitan o frecuentan, se consideran como sectores "críticos y/o vulnerables".

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La internacionalización de los Gobiernos Locales o las regiones es un fenómeno que día a día está tomando una dimensión y magnitud mayor a nivel internacional. Han sido la globalización, la descentralización y la participación en acuerdos de integración económica los incentivos que impulsan a las regiones a buscar un status y un espacio de participación internacional en temas económicos, ambientales, culturales y de cooperación. En ese sentido la motivación de este Estudio de Caso es analizar el proceso a través del cual Nuevo León logró impulsar la internacionalización de su territorio en el periodo 2003-2009 a partir de la entrada en vigencia del Tratado de Libre Comercio de América del Norte.