1,404 research outputs found

    How much solute is needed to inhibit the fluid to gel membrane phase transition at low hydration?

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    We present a quantitative study of the effect of sugars on the membrane gel-fluid phase transition as a function of sugar:lipid ratio. We show that the maximum effect occurs at around 1.5 sugar rings per molecule for both mono- and di-saccharides. We present a theoretical model to try to explain these results, and discuss the assumptions inherent in the model

    Hypergastrinemia and a duodenal ulcer caused by gastric duplication

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    Governance of Offshore IT Outsourcing at Shell Global Functions IT-BAM Development and Application of a Governance Framework to Improve Outsourcing Relationships

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    The lack of effective IT governance is widely recognized as a key inhibitor to successful global IT outsourcing relationships. In this study we present the development and application of a governance framework to improve outsourcing relationships. The approach used to developing an IT governance framework includes a meta model and a customization process to fit the framework to the target organization. The IT governance framework consists of four different elements (1) organisational structures, (2) joint processes between in- and outsourcer, (3) responsibilities that link roles to processes and (4) a diverse set of control indicators to measure the success of the relationship. The IT governance framework is put in practice in Shell GFIT BAM, a part of Shell that concluded to have a lack of management control over at least one of their outsourcing relationships. In a workshop the governance framework was used to perform a gap analysis between the current and desired governance. Several gaps were identified in the way roles and responsibilities are assigned and joint processes are set-up. Moreover, this workshop also showed the usefulness and usability of the IT governance framework in structuring, providing input and managing stakeholders in the discussions around IT governance

    Categorical Code Constructions

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    Abstract We study categories of codes and precodes. The objects in these categories capture the encoding and decoding process of error control codes, source codes, or cryptographic codes. We show that these categories are complete and cocomplete. This gives a wealth of new code constructions

    Cold Plasma Dispersion Relations in the Vicinity of a Schwarzschild Black Hole Horizon

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    We apply the ADM 3+1 formalism to derive the general relativistic magnetohydrodynamic equations for cold plasma in spatially flat Schwarzschild metric. Respective perturbed equations are linearized for non-magnetized and magnetized plasmas both in non-rotating and rotating backgrounds. These are then Fourier analyzed and the corresponding dispersion relations are obtained. These relations are discussed for the existence of waves with positive angular frequency in the region near the horizon. Our results support the fact that no information can be extracted from the Schwarzschild black hole. It is concluded that negative phase velocity propagates in the rotating background whether the black hole is rotating or non-rotating.Comment: 27 pages, 11 figures accepted for publication in Gen. Relat. & Gravi

    Ferromagnetism in magnetically doped III-V semiconductors

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    The origin of ferromagnetism in semimagnetic III-V materials is discussed. The indirect exchange interaction caused by virtual electron excitations from magnetic impurity level in the bandgap to the valence band can explain ferromagnetism in GaAs(Mn) no matter samples are degenerated or not. Formation of ferromagnetic clusters and percolation picture of phase transition describes well all available experimental data and allows to predict the Mn-composition dependence of transition temperature in wurtzite (Ga,In,Al)N epitaxial layers.Comment: 4 pages with 3 figure

    Numerical Solutions of ideal two-fluid equations very closed to the event horizon of Schwarzschild black hole

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    The 3+1 formalism of Thorne, Price and Macdonald has been used to derive the linear two-fluid equations describing transverse and longitudinal waves propagating in the two-fluid ideal collisionless plasmas surrounding a Schwarzschild black hole. The plasma is assumed to be falling in radial direction toward the event horizon. The relativistic two-fluid equations have been reformulate, in analogy with the special relativistic formulation as explained in an earlier paper, to take account of relativistic effects due to the event horizon. Here a WKB approximation is used to derive the local dispersion relation for these waves and solved numerically for the wave number k.Comment: 16 pages, 15 figures. arXiv admin note: text overlap with arXiv:0902.3766, arXiv:0807.459
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