12,304 research outputs found

    The Structure and Freezing of fluids interacting via the Gay-Berne (n-6) potentials

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    We have calculated the pair correlation functions of a fluid interacting via the Gay-Berne(n-6) pair potentials using the \PY integral equation theory and have shown how these correlations depend on the value of n which measures the sharpness of the repulsive core of the pair potential. These results have been used in the density-functional theory to locate the freezing transitions of these fluids. We have used two different versions of the theory known as the second-order and the modified weighted density-functional theory and examined the freezing of these fluids for 8≤n≤308 \leq n \leq 30 and in the reduced temperature range lying between 0.65 and 1.25 into the nematic and the smectic A phases. For none of these cases smectic A phase was found to be stabilized though in some range of temperature for a given nn it appeared as a metastable state. We have examined the variation of freezing parameters for the isotropic-nematic transition with temperature and nn. We have also compared our results with simulation results wherever they are available. While we find that the density-functional theory is good to study the freezing transitions in such fluids the structural parameters found from the \PY theory need to be improved particularly at high temperatures and lower values of nn.Comment: 21 Pages (in RevTex4), 6 GIF and 4 Postscript format Fig

    Technology Transfer through Imports

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    While there is general agreement that technology differences must figure prominently in any successful account of the cross-country income variation, not much is known on the source of these technology differences. This paper examines cross-country income differences in terms of factor accumulation, domestic R&D, and foreign technological spillovers. The empirical analysis encompasses seventeen industrialized countries in four continents over three decades, at a level disaggregated enough to identify innovations in a number of key high-tech sectors. International technology transfer is found to play a crucial part in accounting for income differences. We also relate technology transfer to imports, showing that imports are often a major channel. At the same time, our analysis highlights that international technology transfer varies importantly across industries and countries.

    Cyclic representations of the periodic Temperley Lieb algebra, complex Virasoro representations and stochastic processes

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    An NN (LL/2){L} \choose {L/2}-dimensional representation of the periodic Temperley-Lieb algebra TLL(x)TL_L(x) is presented. It is also a representation of the cyclic group ZNZ_N. We choose x=1x = 1 and define a Hamiltonian as a sum of the generators of the algebra acting in this representation. This Hamiltonian gives the time evolution operator of a stochastic process. In the finite-size scaling limit, the spectrum of the Hamiltonian contains representations of the Virasoro algebra with complex highest weights. The N=3N = 3 case is discussed in detail. One discusses shortly the consequences of the existence of complex Virasoro representations on the physical properties of the systems.Comment: 5 pages, 6 figure

    Manual for Program PSTRESS: Peel stress computation

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    Described is the use of the interactive FORTRAN computer program PSTRESS, which computes a closed form solution for two bonded plates subjected to applied moments, vertical shears, and in-plane forces. The program calculates in-plane stresses in the plates, deflections of the plates, and peel and shear stresses in the adhesive. The document briefly outlines the analytical method used by PSTRESS, describes the input and output of the program, and presents a sample analysis. The results of the latter are shown to be within a few percent of results obtained using a NASTRAN finite element analysis. An appendix containing a listing of PSTRESS is included
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