3,273 research outputs found

    Linear-Logic Based Analysis of Constraint Handling Rules with Disjunction

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    Constraint Handling Rules (CHR) is a declarative committed-choice programming language with a strong relationship to linear logic. Its generalization CHR with Disjunction (CHRv) is a multi-paradigm declarative programming language that allows the embedding of horn programs. We analyse the assets and the limitations of the classical declarative semantics of CHR before we motivate and develop a linear-logic declarative semantics for CHR and CHRv. We show how to apply the linear-logic semantics to decide program properties and to prove operational equivalence of CHRv programs across the boundaries of language paradigms

    Deep Reconditioning Testing for near Earth Orbits

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    The problems and benefits of deep reconditioning to near Earth orbit missions with high cycle life and shallow discharge depth requirements is discussed. A simple battery level approach to deep reconditioning of nickel cadmium batteries in near Earth orbit is considered. A test plan was developed to perform deep reconditioning in direct comparison with an alternative trickle charge approach. The results demonstrate that the deep reconditioning procedure described for near Earth orbit application is inferior to the alternative of trickle charging

    Two years of on-orbit gallium arsenide performance from the LIPS solar cell panel experiment

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    The LIPS on-orbit performance of the gallium arsenide panel experiment was analyzed from flight operation telemetry data. Algorithms were developed to calculate the daily maximum power and associated solar array parameters by two independent methods. The first technique utilizes a least mean square polynomial fit to the power curve obtained with intensity and temperature corrected currents and voltages; whereas, the second incorporates an empirical expression for fill factor based on an open circuit voltage and the calculated series resistance. Maximum power, fill factor, open circuit voltage, short circuit current and series resistance of the solar cell array are examined as a function of flight time. Trends are analyzed with respect to possible mechanisms which may affect successive periods of output power during 2 years of flight operation. Degradation factors responsible for the on-orbit performance characteristics of gallium arsenide are discussed in relation to the calculated solar cell parameters. Performance trends and the potential degradation mechanisms are correlated with existing laboratory and flight data on both gallium arsenide and silicon solar cells for similar environments

    Polarization probes of vorticity in heavy ion collisions

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    We discuss the information that can be deduced from a measurement of particle (hyperon or vector meson) polarization in ultrarelativistic nuclear collisions. We describe the sensitivity of polarization to initial conditions, hydrodynamic evolution and mean free path, and find that the polarization observable is sensitive to all details and stages of the system's evolution. We suggest that an experimental investigation covering production plane and reaction plane polarizations, as well as the polarization of jet-associated particles in the plane defined by the jet and particle direction, can help in disentangling the factors contributing to this observable. Scans of polarization in energy and rapidity might also point to a change in the system's properties.Comment: In press, Phys.Rev.C. One new figure, text streamlined and edited, physics conclusions and reasoning not change

    Federal Invome Tax Discrimination Between Married and Single Taxpayers

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    This article explores the present tax rate structure and its implications, considers the historical events and policies which created four separate tax rates, analyzes the tax policies embodied by the different rate treatment of married and single taxpayers, and examines the constitutional problems involved in maintaining the present disparate tax treatment. An alternative tax rate treatment, which will avoid the discrimination inherent in the present system, is suggested

    First results of the CERN Resonant WISP Search (CROWS)

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    The CERN Resonant WISP Search (CROWS) probes the existence of Weakly Interacting Sub-eV Particles (WISPs) like axions or hidden sector photons. It is based on the principle of an optical light shining through the wall experiment, adapted to microwaves. Critical aspects of the experiment are electromagnetic shielding, design and operation of low loss cavity resonators and the detection of weak sinusoidal microwave signals. Lower bounds were set on the coupling constant g=4.5108g = 4.5 \cdot 10^{-8} GeV1^{-1} for axion like particles with a mass of ma=7.2μm_a = 7.2 \mueV. For hidden sector photons, lower bounds were set for the coupling constant χ=4.1109\chi = 4.1 \cdot 10^{-9} at a mass of mγ=10.8μm_{\gamma'} = 10.8 \mueV. For the latter we were probing a previously unexplored region in the parameter space

    Electron capture to continuum in collisions of bare projectiles with Ne targets

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    Abstract. We have investigated the cusp resulting from electron capture to the continuum of 1.25-5 MeV m u- ' fully stripped hydrogen and oxygen as a function of the collision energy and the detector angular resolution B o. It is revealed that the characteristic cusp shape parameters depend strongly on the experimental resolution. Our experimental data are "pared with the second-order Born theory and the impulse approximation. Both theories mnhrm the 8, dependence of the shape parameters and gjve a reasonable descrip-lion of the cusp asymmetry. However, theory tends to overestimate the absolute cross sections, in particular in the case of oxygen. 1

    Optical Emission and Laser Spectroscopy in Studies of Sputtering: Actual Research Activities and Recent Achievements

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    Laser Spectroscopy has been developed into a powerful tool for the detection and energy analysis of neutral particles. Laser Induced Fluorescence Spectroscopy (LIF) has yielded a wealth of information about sputtered neutral particles. In addition, Laser Ionization Spectroscopy has recently offered an increased detection sensitivity. In this paper a summary of recent results is given. By combining LIF with other methods capable of measuring densities and energy distributions of sputtered excited atoms in short lived states, new information about sputtering and excitation mechanisms have been recently obtained and will be summarized here

    The time-dependent localization of Ki 67 antigen-positive cells in human skin wounds

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    A total of 77 human skin wounds with a post-infliction interval between 3 h and 7 months were investigated and the proliferation marker antigen Ki 67 was visualized in paraffin sections using a specific monoclonal antibody (MIB). The re-built epidermal layer covering the former lesional area showed only a few basal cells positively staining for Ki 67 antigen. No enhanced reactivity was found when compared to uninjured skin. In basal cells of the epidermis adjacent to the wound area, however, varying numbers of positive cells occurred, but no information useful for a reliable time estimation of skin wounds could be obtained due to the considerable variability in the number of Ki 67 positive epidermal basal cells found in non-damaged skin. Fibroblastic cells in the wound area revealed an increased number of Ki 67-positive sites which could first be detected in a 1.5-day-old skin lesion. Positive results could be obtained in every specimen investigated after a post-infliction interval of 6 days up to 1.5 months. Only the scar tissue of the oldest wound examined (wound age 7 months) revealed no increase in the number of positively staining fibroblasts. Therefore, positive results indicate a wound age of at least approximately 1.5 days and the lack of an increased number of positive fibroblastic cells in a sufficient number of specimens indicates at a wound age of less than 6 days, but cannot totally exclude longer post-infliction intervals
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