Effect of oxygen vacancies on the elastic properties of zinc oxide: A first-principles investigation

The effect of oxygen vacancies on the elastic properties of zinc oxide (ZnO) is examined using first-principles calculations based on density functional theory. Formation energies of vacancies in different types of oxygen deficient structures were analyzed to ascertain their stability. This analysis reveals that the doubly-charged oxygen vacancy under zinc-rich growth conditions is the most stable. Results show considerable degradation of some of the elastic moduli due to the presence of oxygen vacancies, which is in agreement with recent experiments. The decrease observed in elastic constants is more pronounced with increase in vacancy concentration. Further, the charge state of the defect structure was found to influence the shear elastic constants. Evaluation of elastic anisotropy of stoichiometric and oxygen deficient ZnO indicates the significant anisotropy in elastic properties and stiff c-axis orientation. (C) 2014 Elsevier B.V. All rights reserved.

Decomposing the Gender Wage Gap: The effect of firms, occupations and Job Stratification

This paper presents new evidence on the role of segregation into firms, occupations within a firm and stratification into professional categories within firm-occupations in explaining the gender wage gap. I use a generalized earnings model that allows observed and unobserved group characteristics to have different impact on wages of men and women within the same group. The database is a large sample of individual wage data from the 1995 Spanish Wage Structure Survey. Results indicate that firm segregation in our sample accounts for around one-fifth of the raw gender wage gap. Occupational segregation within firms accounts for about one-third of the raw wage gap, and stratification into different professional categories within firms and occupations explains another one-third of it. The remaining one-fifth of the overall gap arises from better outcomes of men relative to women within professional categories. It is also found that rewards to both observable and unobservable skills, particularly those related to education, are higher for males than for females within the same group. Finally, mean wages in occupations or job categories with a higher fraction of female co-workers are lower, but the negative impact of femaleness in higher for women.

Competitive Pressure and Job Interview Lying: A Game Theoretical Analysis

We consider a job contest in which candidates go through interviews (cheap talk) and are subject to reference checks. We show how competitive pressure - increasing the ratio of "good" to "bad" type candi- dates - can lead to a vast increase in lying and in some cases make bad hires more likely. As the number of candidates increases, it becomes harder to in- duce truth-telling. The interview stage becomes redundant if the candidates, a priori, know each others' type or the result of their own reference check. Finally, we show that the employer can bene t from committing not to reject all the applicants.

Mídia e Consumo: a afirmação do consumo de cursos MBA nas páginas do Boa Chance

O campo de estudos da Comunicação é conhecido pela sua interdisciplinaridade, o que permite analisar objetos relacionados a outras áreas do conhecimento por meio da perspectiva em que os diferentes tipos de mídia lhes apresentam. Utilizando palavras, imagens e sons os meios de comunicação colaboram para a produção dos significados de uso e apropriação de diferentes produtos e serviços disponíveis para o consumo. Por meio de um intercâmbio com o campo de estudos de consumo e tratando de um produto oriundo do campo da Educação, os cursos de MBA, este trabalho analisa as mensagens produzidas pelo Boa Chance, suplemento publicado pelo jornal O Globo. Para compor o referencial foram considerados teóricos do campo da Comunicação, Consumo, Educação e Representação Social. Além de oferecerem subsídios para refletir sobre o consumo desse tipo de produto, as idéias e conceitos apresentados também colaboram para compor as categorias elaboradas para a análise das matérias publicadas. Para aprofundar um pouco mais sobre os cursos de MBA foi traçado um histórico desse tipo de ensino, desde o seu surgimento nos Estados Unidos, passando pela sua ascensão a partir da década de 1940 até a sua chegada ao Brasil. A forma como os cursos adentraram a pauta dos cadernos de emprego, em especial, do Boa Chance, também é abordada. Entrevistas com repórteres e editores que trabalharam ou que ainda estão no caderno permitiram identificar o contexto em que as pautas relacionadas a esse tema se tornaram mais frequentes. A partir disso, foi possível compreender que o assunto começou a ganhar mais espaço na mesma medida que cresce a oferta de vagas pelas instituições, no começo dos anos 2000. Para entender de que maneira os meios de comunicação abordam para esse tipo de consumo e também quais são as representações que ele produz sobre os MBAs, foram analisadas 26 edições do caderno recolhidas entre 2009 e 2010.

The effect of diffusion and overhangs/vacancies on the microstructure of zig-zag thin film

Basing on some growth models of thin film, we have investigated the growth mechanism of glancing angle deposition (GLAD) film. The simulation verifies that the overhangs/vacancies also contribute to the columnar growth as well as the self-shadowing effect for GLAD thin film. Besides, we have studied the effect of the deposition rate, surface and bulk diffusions on the microstructure of thin film using the time-dependent Monte Carlo method. The results show that the surface and bulk diffusions can significantly enhance the packing density of thin film in GLAD growth, and the increase of the deposition rate induce the moderate decrease of the packing density. (c) 2006 Elsevier B.V. All rights reserved.