5,113 research outputs found

    An Investigation of Knowledge Transfer and Retention in a Government Procurement Office

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    There is no measure for the loss of corporate memory. Organizations build a reservoir of knowledge in its employees, and this knowledge becomes a critical ingredient in an organization’s ability to carry out its mission. Knowledgeable people are extremely valuable and once they leave, their organizationally-applied knowledge leaves with them. This study introduces specific knowledge attributes that significantly impact effective tacit and explicit knowledge transfer and retention. Under this construct the proposed investigation explores a government program office to see if replacing experienced government employees with outsourced personnel impacts corporate knowledge retention. The study concludes that a loss of corporate knowledge can occur within U.S. government procurement program offices when government personnel are replaced with contractors who do not transfer their knowledge. When the organization does not have a useful knowledge management system outsourced employees have a lack of trust in the system, a lack of transferred knowledge can be expected. For this reason, contractors use other means to store and transfer their knowledge in systems not available or accessible to the organization

    Epitaxial silicon grown on CeO2/Si(111) structure by molecular beam epitaxy

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    Using electron beam evaporation, a Si/CeO2/Si(111) structure has been grown in a molecular beam epitaxy machine. In situ low energy electron diffraction, cross sectional transmission electron microscopy, selected area diffraction, and atomic force microscopy have been used to structurally characterize the overlying silicon layer and show it to be single crystalline and epitaxially oriented. Rutherford backscattering and energy dispersive x-ray analysis have been used to confirm the presence of a continuous 23 Ă… CeO2 layer at the interface. Rutherford backscattering and x-ray photoemission spectroscopy show an additional presence of cerium both at the exposed silicon surface and incorporated in low levels (~ 1%) within the silicon film, suggesting a growth mechanism with cerium riding atop the silicon growth front leaving behind small amounts of cerium incorporated in the growing silicon crystal

    Analytic Continuation of Massless Two-Loop Four-Point Functions

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    We describe the analytic continuation of two-loop four-point functions with one off-shell external leg and internal massless propagators from the Euclidean region of space-like 1→31\to 3 decay to Minkowskian regions relevant to all 1→31\to 3 and 2→22\to 2 reactions with one space-like or time-like off-shell external leg. Our results can be used to derive two-loop master integrals and unrenormalized matrix elements for hadronic vector-boson-plus-jet production and deep inelastic two-plus-one-jet production, from results previously obtained for three-jet production in electron--positron annihilation.Comment: 26 pages, LaTe

    Smectic ordering in liquid crystal - aerosil dispersions I. X-ray scattering

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    Comprehensive x-ray scattering studies have characterized the smectic ordering of octylcyanobiphenyl (8CB) confined in the hydrogen-bonded silica gels formed by aerosil dispersions. For all densities of aerosil and all measurement temperatures, the correlations remain short range, demonstrating that the disorder imposed by the gels destroys the nematic (N) to smectic-A (SmA) transition. The smectic correlation function contains two distinct contributions. The first has a form identical to that describing the critical thermal fluctuations in pure 8CB near the N-SmA transition, and this term displays a temperature dependence at high temperatures similar to that of the pure liquid crystal. The second term, which is negligible at high temperatures but dominates at low temperatures, has a shape given by the thermal term squared and describes the static fluctuations due to random fields induced by confinement in the gel. The correlation lengths appearing in the thermal and disorder terms are the same and show strong variation with gel density at low temperatures. The temperature dependence of the amplitude of the static fluctuations further suggests that nematic susceptibility become suppressed with increasing quenched disorder. The results overall are well described by a mapping of the liquid crystal-aerosil system into a three dimensional XY model in a random field with disorder strength varying linearly with the aerosil density.Comment: 14 pages, 13 figure

    Crossing Crawford’s conceptual divide: monumental linear earthworks in later prehistoric and early medieval Britain

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    In its early decades, Antiquity regularly featured the subject of linear earthworks that crisscross the British landscape. Subsequently, however, discussion has been largely relegated to period-specific and local journals. As a result, interpretations of these imposing but often poorly dated earthworks have been drawn in the contrasting research traditions of later prehistory and the early medieval period. Here, the authors propose a comparative dialogue as a means for reinterpreting these landscape features, and as a lens through which to explore social complexity. Combined with advances in archaeometrical dating, this new approach promises to reinvigorate the study of some of Britain’s largest archaeological monuments

    Smectic ordering in liquid crystal - aerosil dispersions II. Scaling analysis

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    Liquid crystals offer many unique opportunities to study various phase transitions with continuous symmetry in the presence of quenched random disorder (QRD). The QRD arises from the presence of porous solids in the form of a random gel network. Experimental and theoretical work support the view that for fixed (static) inclusions, quasi-long-range smectic order is destroyed for arbitrarily small volume fractions of the solid. However, the presence of porous solids indicates that finite-size effects could play some role in limiting long-range order. In an earlier work, the nematic - smectic-A transition region of octylcyanobiphenyl (8CB) and silica aerosils was investigated calorimetrically. A detailed x-ray study of this system is presented in the preceding Paper I, which indicates that pseudo-critical scaling behavior is observed. In the present paper, the role of finite-size scaling and two-scale universality aspects of the 8CB+aerosil system are presented and the dependence of the QRD strength on the aerosil density is discussed.Comment: 14 pages, 10 figures, 1 table. Companion paper to "Smectic ordering in liquid crystal - aerosil dispersions I. X-ray scattering" by R.L. Leheny, S. Park, R.J. Birgeneau, J.-L. Gallani, C.W. Garland, and G.S. Iannacchion

    Effects of selective breeding for increased wheel-running behavior on circadian timing of substrate oxidation and ingestive behavior

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    Fluctuations in substrate preference and utilization across the circadian cycle may be influenced by the degree of physical activity and nutritional status. In the present study, we assessed these relationships in control mice and in mice from a line selectively bred for high voluntary wheel-running behavior, either when feeding a carbohydrate-rich/low-fat (LF) or a high-fat (HF) diet. Housed without wheels, selected mice, and in particular the females, exhibited higher cage activity than their non-selected controls during the dark phase and at the onset of the light phase, irrespective of diet. This was associated with increases in energy expenditure in both sexes of the selection line. In selected males, carbohydrate oxidation appeared to be increased compared to controls. In contrast, selected females had profound increases in fat oxidation above the levels in control females to cover the increased energy expenditure during the dark phase. This is remarkable in light of the finding that the selected mice, and in particular the females showed higher preference for the LF diet relative to controls. It is likely that hormonal and/or metabolic signals increase carbohydrate preference in the selected females, which may serve optimal maintenance of cellular metabolism in the presence of augmented fat oxidation. (C) 2010 Elsevier Inc. All rights reserved

    Hydrogen-bonded Silica Gels Dispersed in a Smectic Liquid Crystal: A Random Field XY System

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    The effect on the nematic to smectic-A transition in octylcyanobiphenyl (8CB) due to dispersions of hydrogen-bonded silica (aerosil) particles is characterized with high-resolution x-ray scattering. The particles form weak gels in 8CB creating a quenched disorder that replaces the transition with the growth of short range smectic correlations. The correlations include thermal critical fluctuations that dominate at high temperatures and a second contribution that quantitatively matches the static fluctuations of a random field system and becomes important at low temperatures.Comment: 10 pages, 4 postscript figures as separate file
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