9,167 research outputs found

    Spindensities in Pseudo-classical kinetic theory

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    In this paper the classical limit of relativistic transport theories for spin 1/2 fermions is examined through a comparison with the classical kinetic theory derived from N=1 supersymmetric classical mechanics. The conclusion is that in the classical limit spindensities, i.e. the axial-vector contribution to the relativistic Wigner-function, vanishes and dipole-densities, i.e. the spin-tensor contributions to the relativistic Wigner function, may survive.Comment: Latex 22 pages, 63628 bytes. No figure

    On non-Hamiltonian circulant digraphs of outdegree three

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    We construct infinitely many connected, circulant digraphs of outdegree three that have no hamiltonian circuit. All of our examples have an even number of vertices, and our examples are of two types: either every vertex in the digraph is adjacent to two diametrically opposite vertices, or every vertex is adjacent to the vertex diametrically opposite to itself

    Gas ion laser construction for electrically isolating the pressure gauge thereof

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    The valve and the pressure gauge of a gas ion laser were electrically insulated from the laser discharge path by connecting them in series with the cathode of the laser. The laser cathode can be grounded and preferably is a cold cathode although a hot cathode may be used instead. The cold cathode was provided with a central aperture to which was connected both the pressure gauge and the gas pressure reservoir through the valve. This will effectively prevent electric discharges from passing either to the pressure gauge or the valve which would otherwise destroy the pressure gauge

    Continuous cell lysis in microfluidics through acoustic and optoelectronic tweezers

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    A versatile platform for efficient cell lysis using a combination of acoustic and electric fields in a microchannel is presented. Cell membrane disruption is triggered by electric fields inducing electroporation and then lysis. The principle of optoelectronic tweezers (OET) is applied to control the electric field strength and a surface acoustic wave transducer is attached to an OET chip to implement acoustic tweezing (AT). The system is characterized in terms of spatial control of electric fields, single cell precision and lysi

    Analytic Solution for the Ground State Energy of the Extensive Many-Body Problem

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    A closed form expression for the ground state energy density of the general extensive many-body problem is given in terms of the Lanczos tri-diagonal form of the Hamiltonian. Given the general expressions of the diagonal and off-diagonal elements of the Hamiltonian Lanczos matrix, αn(N)\alpha_n(N) and βn(N)\beta_n(N), asymptotic forms α(z)\alpha(z) and β(z)\beta(z) can be defined in terms of a new parameter z≡n/Nz\equiv n/N (nn is the Lanczos iteration and NN is the size of the system). By application of theorems on the zeros of orthogonal polynomials we find the ground-state energy density in the bulk limit to be given in general by E0=inf [α(z)−2 β(z)]{\cal E}_0 = {\rm inf}\,\left[\alpha(z) - 2\,\beta(z)\right].Comment: 10 pages REVTex3.0, 3 PS figure

    Capturing the environment, a metafrontier approach to the drinking water sector.

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    Environmental factors add complexity to the comparison between specific activities or entire entities. Decision making units with an inferior performance are tempted to invoke that their organization is different from the others in the data set. By reinterpreting and extending the metafrontier literature, we propose an all-embracing concept to fully capture the operational environment. We suggest the ‘Group Specific Technical Efficiency’ as a new measure to assess the overall efficiency of a utility while allowing for environmental differences. A real-world example of drinking water utilies out of 5 different countries illustrates the concept. JEL Classification: C14, C61, D24, L95Free Disposal Hull, Efficiency Measurement, Environmental Variables, Metafrontier, Water Industry
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