Nature of the green luminescent center in zinc oxide

EPR, optical absorption, and photoluminescence spectroscopies are used to characterize a wide range of different ZnO phosphor powders. A good correlation is generally observed between the 510-nm green emission intensity and the density of paramagnetic isolated oxygen vacancies. Both quantities are found to peak at a free-carrier density of about 1.4x10{sup 18}cm{sup -3}. The green emission intensity can be strongly influenced by free-carrier depletion at the particle surface, especially for small particles and/or low doping. The data suggest that the green PL in ZnO phosphors is due to recombination of electrons in singly occupied oxygen vacancies with photoexcited holes in the valence band

Cultural Orientations of sport managers

Various interpretations of sport management are cultural constructs underpinned by core assumptions and values held by members of professional communities. Sport managers world wide share common problems, but differ in how they resolve them. These universal differences emerge from the relationships they form with other people, and their attitude to time, activities and the natural environment. This paper examines the role of sport managers’ cultural orientations in the interpretation and practice of sport management. Using a multiple dimension model (Hampden-Turner and Trompenaars, 2000) it sketches the cultural profiles of fifteen sport managers from seven countries. A combination of methods was employed including questionnaires, interviews and participant observation. It is contended that the culture of sport management concerns a social process by which managers get involved in reconciling seven fundamental cultural dilemmas in order to perform tasks and achieve certain ends. Thus, a knowledge of the cultural meaning of sport management in a particular country would equip sport managers with a valuable tool in managing both the cultural diversity of their own work forces and in developing appropriate cross-cultural skills needed for running international events, marketing campaigns, sponsorship deals and joint ventures

Dialectics and difference: against Harvey's dialectical post-Marxism

David Harvey`s recent book, Justice, nature and the geography of difference (JNGD), engages with a central philosophical debate that continues to dominate human geography: the tension between the radical Marxist project of recent decades and the apparently disempowering relativism and `play of difference' of postmodern thought. In this book, Harvey continues to argue for a revised `post-Marxist' approach in human geography which remains based on Hegelian-Marxian principles of dialectical thought. This article develops a critique of that stance, drawing on the work of Jacques Derrida, Gilles Deleuze and Felix Guattari. I argue that dialectical thinking, as well as Harvey's version of `post-Marxism', has been undermined by the wide-ranging `post-' critique. I suggest that Harvey has failed to appreciate the full force of this critique and the implications it has for `post-Marxist' ontology and epistemology. I argue that `post-Marxism', along with much contemporary human geography, is constrained by an inflexible ontology which excessively prioritizes space in the theory produced, and which implements inflexible concepts. Instead, using the insights of several `post-' writers, I contend there is a need to develop an ontology of `context' leading to the production of `contextual theories'. Such theories utilize flexible concepts in a multilayered understanding of ontology and epistemology. I compare how an approach which produces a `contextual theory' might lead to more politically empowering theory than `post-Marxism' with reference to one of Harvey's case studies in JNGD

Paradox Research in Management Science: Looking Back to Move Forward

Paradox studies offer vital and timely insights into an array of organizational tensions. Yet this field stands at a critical juncture. Over the past 25 years, management scholars have drawn foundational insights from philosophy and psychology to apply a paradox lens to organizational phenomena. Yet extant studies selectively leverage ancient wisdom, adopting some key insights while abandoning others. Using a structured content analysis to review the burgeoning management literature, we surface six key themes, which represent the building blocks of a meta-theory of paradox. These six themes received varying attention in extant studies: paradox scholars emphasize types of paradoxes, collective approaches, and outcomes, but pay less attention to relationships within paradoxes, individual approaches, and dynamics. As this analysis suggests, management scholars have increasingly simplified the intricate, often messy phenomena of paradox. Greater simplicity renders phenomena understandable and testable, however, oversimplifying complex realities can foster reductionist and incomplete theories. We therefore propose a future research agenda targeted at enriching a meta-theory of paradox by reengaging these less developed themes. Doing so can sharpen the focus of this field, while revisiting its rich conceptual roots to capture the intricacies of paradox. This future research agenda leverages the potential of paradox across diverse streams of management science