4,681 research outputs found

    Magnetic Therapy: an Alternative Approach to Treatment

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    Magnetic therapy has been a treatment of choice for hundreds of years in many European countries as well as in several areas of the Orient, but has only recently been gaining popularity in the United States and Canada. It is believed that applying static magnets to a painful body structure will bring relief to the patient. It is also proposed that a general feeling of well ness and increased energy will be gained from magnetic therapy. These benefits are theorized to be attained through the placement of a static magnet on the surface of the body, which blocks the transmission of pain to the central nervous system and causes vasodilatation of local blood vessels allowing the body to heal itself. The purpose of this literature review is to provide a better understanding of the body\u27s responses to natural magnets and the resulting physiological changes that occur. A review of the nervous system with particular attention given to the afferent pain sensation pathway and its controls will be presented, followed by a brief discussion on the physical makeup and chemical components of the circulatory system. A description of natural magnets and their properties will be given, along with a review of how natural magnets affect the nervous and circulatory systems and their potential use in the field of physical therapy

    Exchange-correlation orbital functionals in current-density-functional theory: Application to a quantum dot in magnetic fields

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    The description of interacting many-electron systems in external magnetic fields is considered in the framework of the optimized effective potential method extended to current-spin-density functional theory. As a case study, a two-dimensional quantum dot in external magnetic fields is investigated. Excellent agreement with quantum Monte Carlo results is obtained when self-interaction corrected correlation energies from the standard local spin-density approximation are added to exact-exchange results. Full self-consistency within the complete current-spin-density-functional framework is found to be of minor importance.Comment: 5 pages, 2 figures, submitted to PR

    ALICE HLT TPC GPU Tracker

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    Decay dynamics of quantum dots influenced by the local density of optical states of two-dimensional photonic crystal membranes

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    We have performed time-resolved spectroscopy on InAs quantum dot ensembles in photonic crystal membranes. The influence of the photonic crystal is investigated by varying the lattice constant systematically. We observe a strong slow down of the quantum dots' spontaneous emission rates as the two-dimensional bandgap is tuned through their emission frequencies. The measured band edges are in full agreement with theoretical predictions. We characterize the multi-exponential decay curves by their mean decay time and find enhancement of the spontaneous emission at the bandgap edges and strong inhibition inside the bandgap in good agreement with local density of states calculations.Comment: 9 pages (preprint), 3 figure

    Measurement of the drift field in the ARGONTUBE LAr TPC with 266~nm pulsed laser beams

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    ARGONTUBE is a liquid argon time projection chamber (LAr TPC) with a drift field generated in-situ by a Greinacher voltage multiplier circuit. We present results on the measurement of the drift-field distribution inside ARGONTUBE using straight ionization tracks generated by an intense UV laser beam. Our analysis is based on a simplified model of the charging of a multi-stage Greinacher circuit to describe the voltages on the field cage rings

    A method to suppress dielectric breakdowns in liquid argon ionization detectors for cathode to ground distances of several millimeters

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    We present a method to reach electric field intensity as high as 400 kV/cm in liquid argon for cathode-ground distances of several millimeters. This can be achieved by suppressing field emission from the cathode, overcoming limitations that we reported earlier

    On the Electric Breakdown in Liquid Argon at Centimeter Scale

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    We present a study on the dependence of electric breakdown discharge properties on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).Comment: Minor revision according to editor report. 17 pages, 15 figures, 2 tables. Turboencabulato
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