27,193 research outputs found

    Job Quality and Job Satisfaction Among Casino Workers: The Case of Foxwoods

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    This article examines the quality of casino jobs at the largest Indian casino in the United States. It uses survey responses to measure how Foxwoods\u27 employees evaluate various aspects of their jobs, and it also considers other aspects of job quality such as wages, fringe benefits, and wage inequality. The results are part of the growing literature that considers issues important to the gaming industry in the United States

    Determination of atomic oxygen fluence using spectrophotometric analysis of infrared transparent witness coupons for long duration exposure tests

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    Atomic oxygen degradation is one of several major threats to the durability of spaceborne systems in low Earth orbit. Ground-based simulations are conducted to learn how to minimize the adverse effects of atomic oxygen exposure. Assessing the fluence of atomic oxygen in test chambers such as a plasma asher over long periods of time is necessary for accurate determination of atomic oxygen exposure. Currently, an atomic oxygen susceptible organic material such as Kapton is placed next to samples as a witness coupon and its mass loss is monitored and used to determine the effective atomic oxygen fluence. However, degradation of the Kapton witness coupons occurs so rapidly in plasma ashers that for any long term test many witness coupons must be used sequentially in order to keep track of the fluence. This necessitates opening vacuum to substitute fresh coupons. A passive dosimetry technique was sought to monitor atomic oxygen exposure over longer periods without the need to open the plasma asher to the atmosphere. This paper investigates the use of spectrophotometric analysis of durable IR transparent witness coupons to measure atomic oxygen exposure for longer duration testing. The method considered would be conductive to making in situ measurements of atomic oxygen fluence

    Operator monotones, the reduction criterion and the relative entropy

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    We introduce the theory of operator monotone functions and employ it to derive a new inequality relating the quantum relative entropy and the quantum conditional entropy. We present applications of this new inequality and in particular we prove a new lower bound on the relative entropy of entanglement and other properties of entanglement measures.Comment: Final version accepted for publication, added references in reference [1] and [13

    Quantification of efficiency improvements from integration of battery energy storage systems and renewable energy sources into domestic distribution networks

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    Due to the increasing use of renewable, non-controllable energy generation systems energy storage systems (ESS) are seen as a necessary part of future power delivery systems. ESS have gained research interest and practical implementation over the past decade and this is expected to continue into the future. This is due to the economic and operational benefits for both network operators and customers, battery energy storage system (BESS) is used as the main focus of this research paper. This paper presents an analytical study of the benefits of deploying distributed BESS in an electrical distribution network (DN). The work explores the optimum location of installing BESS and its impact on the DN performance and possible future investment. This study provides a comparison between bulk energy storage installed at three different locations; medium voltage (MV) side and low voltage (LV) side of the distribution transformer (DT) and distributed energy storage at customers’ feeders. The performance of a typical UK DN is examined under different penetration levels of wind energy generation units and BESS. The results show that the minimum storage size is obtained when BESS is installed next to the DT. However, the power loss is reduced to its minimum when BESS and wind energy are both distributed at load busbars. The study demonstrates that BESS installation has improved the loss of life factor of the distribution transformer

    Microrheological Characterisation of Anisotropic Materials

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    We describe the measurement of anisotropic viscoelastic moduli in complex soft materials, such as biopolymer gels, via video particle tracking microrheology of colloid tracer particles. The use of a correlation tensor to find the axes of maximum anisotropy, and hence the mechanical director, is described. The moduli of an aligned DNA gel are reported, as a test of the technique; this may have implications for high DNA concentrations in vivo. We also discuss the errors in microrheological measurement, and describe the use of frequency space filtering to improve displacement resolution, and hence probe these typically high modulus materials.Comment: 5 pages, 5 figures. Replaced after refereeing/ improvement. Main results are the same. The final, published version of the paper is here http://link.aps.org/abstract/PRE/v73/e03190

    Do broad absorption line quasars live in different environments from ordinary quasars?

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    We select a sample of 4200\sim 4200 traditionally defined broad absorption line quasars (BALQs) from the Fifth Data Release quasar catalog of the Sloan Digital Sky Survey. For a statistically homogeneous quasar sample with 1.7z4.21.7\le z\le 4.2, the BAL quasar fraction is 14\sim 14% and is almost constant with redshift. We measure the auto-correlation of non-BAL quasars (nonBALQs) and the cross-correlation of BALQs with nonBALQs using this statistically homogeneous sample, both in redshift space and using the projected correlation function. We find no significant difference between the clustering strengths of BALQs and nonBALQs. Assuming a power-law model for the real space correlation function ξ(r)=(r/r0)1.8\xi(r)=(r/r_0)^{-1.8}, the correlation length for nonBALQs is r0=7.6±0.8h1Mpcr_0=7.6\pm 0.8 h^{-1}{\rm Mpc}; for BALQs, the cross-correlation length is r0=7.4±1.1h1Mpcr_0=7.4\pm 1.1 h^{-1}{\rm Mpc}. Our clustering results suggest that BALQs live in similar large-scale environments as do nonBALQs.Comment: accepted for publication in Ap

    Optimal dense coding with mixed state entanglement

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    I investigate dense coding with a general mixed state on the Hilbert space CdCdC^{d}\otimes C^{d} shared between a sender and receiver. The following result is proved. When the sender prepares the signal states by mutually orthogonal unitary transformations with equal {\it a priori} probabilities, the capacity of dense coding is maximized. It is also proved that the optimal capacity of dense coding χ\chi ^{*} satisfies ER(ρ)χER(ρ)+log2dE_{R}(\rho)\leq \chi ^{*}\leq E_{R}(\rho )+\log_{2}d, where ER(ρ)E_{R}(\rho) is the relative entropy of entanglement of the shared entangled state.Comment: Revised. To appear in J. Phys. A: Math. Gen. (Special Issue: Quantum Information and Computation). LaTeX2e (iopart.cls), 8 pages, no figure
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