1,546 research outputs found

    A low temperature X-ray single-crystal diffraction and polarised infra-red study of epidote

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    The effects of low-temperature on the crystal structure of a natural epidote [Ca1.925Fe0.745Al2.265Ti0.004 Si3.037O12(OH), a = 8.8924(7), b = 5.6214(3), c = 10.1547(6) angstrom and beta = 115.396(8)degrees at room conditions, Sp. Gr. P2(1)/m] have been investigated with a series of structure refinements down to 100 K on the basis of X-ray single-crystal diffraction data. The reflection conditions confirm that the space group is maintained within the T-range investigated. Structural refinements at all temperatures show the presence of Fe3+ at the octahedral M(3) site only [%Fe(M3) = 70.6(4)% at 295 K]. Only one independent proton site was located and two possible H-bonds occur, with O(10) as donor and O(4) and O(2) as acceptors. The H-bonding scheme is maintained down to 100 K and is supported by single crystal room-T polarised FTIR data. FTIR Spectra over the region 4,000-2,500 cm(-1) are dominated by the presence of a strongly pleochroic absorption feature which can be assigned to protonation of O(10)-O(4). Previously unobserved splitting of this absorption features is consistent with a NNN influence due to the presence of Al and Fe3+ on the nearby M(3) site. An additional relatively minor absorption feature in FTIR spectra can be tentatively assigned to protonation of O(10)-O(2). Low-T does not affect significantly the tetrahedral and octahedral bond distances and angles, even when distances are corrected for "rigid body motions". A more significant effect is observed for the bond distances of the distorted Ca(1)- and Ca(2)-polyhedra, especially when corrected for "non-correlated motion". The main low-T effect is observed on the vibrational regime of the atomic sites, and in particular for the two Ca-sites. A significant reduction of the magnitude of the thermal displacement ellipsoids, with a variation of U-eq (defined as one-third of the trace of the orthogonalised U-ij tensor) by similar to 40% is observed for the Ca-sites between 295 and 100 K. Within the same T-range, the U-eq of the octahedral and oxygen sites decrease similarly by similar to 35%, whereas those of the tetrahedral cations by similar to 22%

    Social, behavioral, and cognitive influences on upper echelons during strategy process

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    This study reviews research on the social, behavioral, and cognitive influences on CEOs, top management teams (TMTs), and the CEO-TMT interface during strategic decision making. We identify the key issues examined in this research over the past 10 years and relate developments in the field to previous knowledge in this area. We also attempt to identify what constitutes an established body of knowledge in the field and, therefore, areas that need additional examination. Our review indicates that while there has been an explosion of research on the influence of CEO personality and TMT social processes on strategy process, much remains to be done in terms of examining CEO and TMT cognition, particularly at the level of the CEO-TMT interface

    Missing the point of the practice-based view

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    In this article, we address Jarzabkowski et al.’s strategy-as-practice criticism of Bromiley and Rau’s practice-based view as ignoring the “who” and “how” of practice implementation. Bromiley and Rau explicitly note that any statistical model under the practice-based view should consider mediating and moderating variables that depend on the specific practice and context but that the article would not attempt to identify such variables. Strategy-as-practice’s focus on the “who” and “how” of a practice are two of many such potential mediating or moderating variables. More fundamentally, strategy-as-practice scholars’ discomfort with the practice-based view may arise both from their different definitions of practice and their different approaches to strategy research. Without diminishing the strategy-as-practice’s contribution to strategy research, we argue for the additional value in the practice-based view’s call for systematic, large-scale, quantitative studies that establish the performance impact of specific practices across populations of organizations
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