Mastery-approach and mastery-avoidance goals and their relation with exhaustion and engagement at work: The roles of emotional and instrumental support

The results of two cross-sectional studies (N = 220 and N = 258) indicate that employees' work-related mastery-approach goals (i.e. the striving to improve one's performance at work) were positively associated with work engagement. Further, this relationship is explained by high levels of instrumental support. In contrast, employees' work-related mastery-avoidance goals (i.e. the striving to avoid performing worse than one aspires to) are positive predictors of job detachment and fatigue. The relationships between mastery-avoidance goals and these detrimental work outcomes are explained by low levels of perceived emotional support. Altogether, these results suggest that workers with mastery-approach goals tend to invest in their social work environment by establishing instrumental exchange relationships. Such relationships are considered functional for task performance and explain the positive relationship with work engagement. Employees who hold mastery-avoidance goals, on the other hand, tend to withdraw from the social structure of the workplace which explains the negative relationship with emotional support. In turn, given the lack of emotional support, psychological detachment and fatigue may emerge. These results are discussed in relation to the surging interest in the social mechanisms that result from the pursuit of achievement goals

Review of some critical aspects of Ge and GeOI substrates

International audienceThe challenges posed by the scaling of Silicon (Si) devices make mandatory the study of new materials to overcome the physical limitations of the Si. Germanium (Ge) was actually used in the first transistors but was then abandoned in favour of Si due to difficulties in processing Ge Oxide. However, the introduction of high-K gate dielectrics makes the use of Ge possible in an advanced technology. Its benefits for MOSFET applications are important: better transport properties than with Silicon hence higher saturation currents; lower band gap hence lower supply voltages and lower power dissipation and a lattice parameter compatible with Gallium Arsenide (GaAs) epitaxy. These are the main reasons why, during the last 4 years, the interest in Ge and Ge-On-Insulator (GeOI) substrates fabrication and properties has grown. This paper is a review of the different types of Ge and GeOI substrates, their critical aspects and their new potential applications

Si/InGaN Core/Shell Hierarchical Nanowire Arrays and their Photoelectrochemical Properties

Three-dimensional hierarchical nanostructures were synthesized by the halide chemical vapor deposition of InGaN nanowires on Si wire arrays. Single phase InGaN nanowires grew vertically on the sidewalls of Si wires and acted as a high surface area photoanode for solar water splitting. Electrochemical measurements showed that the photocurrent density with hierarchical Si/InGaN nanowire arrays increased by 5 times compared to the photocurrent density with InGaN nanowire arrays grown on planar Si (1.23 V vs RHE). High-resolution transmission electron microscopy showed that InGaN nanowires are stable after 15 h of illumination. These measurements show that Si/InGaN hierarchical nanostructures are a viable high surface area electrode geometry for solar water splitting.close796