972 resultados para Reclutament i allistament-València-S. XVII


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It is shown that the effect of adsorption of inert molecules on electrode reaction rates is completely accounted for, by introducing into the rate equation, adsorption-induced changes in both the effective electrode area as well as in the electrostatic potential at the reaction site with an additional term for the noncoulombic interaction between the reactant and the adsorbate. The electrostatic potential at the reaction site due to the adsorbed layer is calculated using a model of discretely-distributed molecules in parallel orientation when adsorbed on the electrode with an allowance for thermal agitation. The resulting expression, which is valid for the limiting case of low coverages, is used to predict the types of molecular surfactants that are most likely to be useful for acceleration and inhibition of electrode reactions.

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Research on the achievement of rural and remote students in science and mathematics is located within a context of falling levels of participation in physical science and mathematics courses in Australian schools, and underrepresentation of rural students in higher education. International studies such as the Programme of International Student Assessment (PISA), have reported lower levels of mathematical and scientific literacy in Australian students from rural and remote schools (Thomson et al, 2011). The SiMERR national survey of science, mathematics and ICT education in rural and regional Australia (Lyons et al, 2006) identified factors affecting student achievement in rural and remote schools. Many of the issues faced by rural and remote students in their schools are likely to have implications on their university enrolments in science, technology, engineering and mathematics (STEM) courses. For example, rural and remote students are less likely to attend university in general than their city counterparts and higher university attrition rates have been reported for remote students nationally. This paper examines the responses of a sample of rural/remote Australian first year STEM students at Australian universities to two questions. These related to their intentions to complete the course; and whether -and if so, why- they had ever considered withdrawing from their course. Results indicated that rural students who were still in their course by the end of first year were no more or less likely to consider withdrawing than were their peers from more populous centres. However, almost 20% of the rural cohort had considered withdrawing at some stage in their course, and their explanations provide insights into the reasoning of those who may not persist with their courses at university. These results, in the context of the greater attrition rate of remote students from university, point to the need to identify factors that positively impact on rural and remote students’ interest and achievement in science and mathematics. It also highlights a need for future research into the particular issues remote students may face in deciding whether or not to do science at the two key transition points of senior school and university/TAFE studies, and whether or not to persist in their tertiary studies. This paper is positioned at the intersection of two problems in Australian education. The first is a context of falling levels of participation in physical science and mathematics courses in Australian universities. The second is persistent inequitable access to, and retention in, tertiary education for students from rural and remote areas. Despite considerable research attention to both of these areas over recent years these problems have thus far proved to be intractable. This paper therefore aims to briefly review the relevant Australian literature pertaining to these issues; that is, declining STEM enrolments, and the underrepresentation and retention of rural/remote students in higher education. Given the related problems in these two overlapping domains, we then explore the views of first year rural students enrolled in courses, in relation to their intentions of withdrawing (or not) and the associated reasons for their views.

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Det finns en mätbar entitet i all levande materia, nämligen förhållandet mellan ett atomslags lätta och tunga isotop. Denna entitet divideras med en definierad referens och ett värde erhålls som brukar anges i promille ( ). Värdet är ett mått på isotopfraktionering. Genom att studera ekologi, taxonomi, kretslopp, isotopeffekter, dokumenterad data och metabola effekter kan man skissera över vad isotopfraktionen betyder. Migrationsbeteende, trofinätverk, dieter, miljö- och klimatdata kan rekonstrueras i tid och rum. Vid rekonstruktioner av gången tid har de museala samlingarna en nyckelposition. I litteraturöversikten tas teori, praktik och forskning upp för att påvisa metodens faror och användningsområden.

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Digital image

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We investigate the Einstein relation for the diffusivity-mobility ratio (DMR) for n-i-p-i and the microstructures of nonlinear optical compounds on the basis of a newly formulated electron dispersion law. The corresponding results for III-V, ternary and quaternary materials form a special case of our generalized analysis. The respective DMRs for II-VI, IV-VI and stressed materials have been studied. It has been found that taking CdGeAs2, Cd3As2, InAs, InSb, Hg1−xCdxTe, In1−xGaxAsyP1−y lattices matched to InP, CdS, PbTe, PbSnTe and Pb1−xSnxSe and stressed InSb as examples that the DMR increases with increasing electron concentration in various manners with different numerical magnitudes which reflect the different signatures of the n-i-p-i systems and the corresponding microstructures. We have suggested an experimental method of determining the DMR in this case and the present simplified analysis is in agreement with the suggested relationship. In addition, our results find three applications in the field of quantum effect devices.

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Polymerization of methyl methacrylate in the presence of a mixed ligand complex, [N,N-ethylenebis(salicylideneiminato)](acetylacetonato)cobalt(III) in benzene was studied. The rate of polymerization was proportional to the square root of the concentration of the chelate and the monomer exponent was 1.67 and 1.69 at 60 and 70°C, respectively. The activation energy and the kinetic and transfer constants were evaluated. A free-radical mechanism has been proposed.

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The notions of identity and teacher education have attracted considerable research over the years, revealing a strong correlation between teacher beliefs and practices and the resultant impact on pedagogical practices in the classroom. In an era where the use of digital technologies should be synonymous with teacher pedagogical practices and transforming education, there is a growing need for pre-service teachers to develop an identity that resonates with pedagogical practices that engage and connect with students in a positive and productive way. With many educational institutions also mandating that educators use digital technologies as a tool to support and enhance teaching, pre-service teacher education needs to ensure that students understand and develop a positive identity within this digital world. Current literature acknowledges that many educators adopt digital technologies in the classroom without sometimes fully understanding its scope or impact. It is within this context that this paper reports on a three-year study of first year pre-service education students and their understanding of identity in a digital world. More specifically, the study identifies how students currently use social and digital media in their personal and professional lives to identify themselves online in order to promote a positive image. The study also seeks to identify how these technologies and an understanding of identity can be utilised to promote a positive first year experience.