37,619 research outputs found

    Experimental demonstration of a Rydberg-atom beam splitter

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    Inhomogeneous electric fields generated above two-dimensional electrode structures have been used to transversely split beams of helium Rydberg atoms into pairs of spatially separated components. The atomic beams had initial longitudinal speeds of between 1700 and 2000 m/s and were prepared in Rydberg states with principle quantum number n=52n=52 and electric dipole moments of up to 8700 D by resonance-enhanced two-color two-photon laser excitation from the metastable 1s2s 3^3S1_1 level. Upon exiting the beam splitter the ensembles of Rydberg atoms were separated by up to 15.6 mm and were detected by pulsed electric field ionization. Effects of amplitude modulation of the electric fields of the beam splitter were shown to cause particle losses through transitions into unconfined Rydberg-Stark states.Comment: 6 pages, 5 figure

    Antenna Technology for QUASAT application

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    A hybrid growth version of the advanced Sunflower, or precision deployable, antenna was adopted as the configuration proposed for the QUASAT very long baseline interferometry mission. The antenna consists of rigid panels of graphite-epoxy facesheets covering aluminum honeycomb sandwich. The six main folding panels are hinged to a cantilevered support ring attached to the periphery of the center section. Six pairs of intermediate panels are located between these panels and are hinged to each other and to the main panels. The flight configuration, antenna weight, a mass properties, frequency, and contour tolerance are discussed. The advantages of the solid antenna surface cover an all-mesh contour are examined

    Education’s not black and white, it’s vibrant grey

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    This paper offers a learner’s eye-view of a journey through education, written in an auto-narrative style. Sarah’s story spans from Secondary School to College and through University finishing at the point of Graduation. Revealed in this open and honest account is an insight to coping with home life whilst navigating the trials of the Education system. Sarah makes criticisms of her peers at every level reminding us how competitive some students have to be to get on and achieve success in their education. Critical judgements are also made about Sarah’s School teachers and University lecturers, which are at times as rewarding as they are uncomfortable, but always truthful. Consequently, there is much to learn by both academics and students from this sensitive and vulnerable personal revelation. Sarah’s evidence in turn points to some fundamental questions about the genuine outcomes of the Educational system, e.g. what are we actually teaching young people to be like? And do we like the product in terms of their values, beliefs and motives? A concluding message from Sarah’s perspective is that greater independence in learning, freedom in thinking and equipping people to reason, judge and make decisions in whatever realm, may be defining steps towards becoming educated

    A Pulsed Synchrotron for Muon Acceleration at a Neutrino Factory

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    A 4600 Hz pulsed synchrotron is considered as a means of accelerating cool muons with superconducting RF cavities from 4 to 20 GeV/c for a neutrino factory. Eddy current losses are held to less than a megawatt by the low machine duty cycle plus 100 micron thick grain oriented silicon steel laminations and 250 micron diameter copper wires. Combined function magnets with 20 T/m gradients alternating within single magnets form the lattice. Muon survival is 83%.Comment: 4 pages, 1 figures, LaTeX, 5th International Workshop on Neutrino Factories and Superbeams (NuFact 03), 5-11 Jun 2003, New Yor

    Complications of Circumcision

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    In the United States, circumcision is a commonly performed procedure. It is a relatively safe procedure with a low overall complication rate. Most complications are minor and can be managed easily. Though uncommon, complications of circumcision do represent a significant percentage of cases seen by pediatric urologists. Often they require surgical correction that results in a significant cost to the health care system. Severe complications are quite rare, but death has been reported as a result in some cases. A thorough and complete preoperative evaluation, focusing on bleeding history and birth history, is imperative. Proper selection of patients based on age and anatomic considerations as well as proper sterile surgical technique are critical to prevent future circumcision-related adverse events

    The limitations of speech control: perceptions of provision of speech-driven environmental controls

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    This study set out to collect data from assistive technology professionals about their provision of speech-driven environmental control systems. This study is part of a larger study looking at developing a new speech-driven environmental control system

    Missing in Action? Electronic Gaming Machines in Gambling Studies Research

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    In the past thirty years casinos across the world have become dominated by the rise of “electronic gaming machines” (EGMs). Expanding with tremendous speed, this technology has arguably become the dominant form of non-online gambling around the world at time of writing (DeMichele, 2017; Schwartz, 2018). EGMs are also noted as being one of the most harmful forms of gambling, with significant numbers of players betting beyond their financial limits (MacLaren et al, 2012; Stewart & Wohl, 2013), spending a disproportionate amount of time playing (Cummings, 1999; Ballon, 2005; Schüll, 2012; cf. Dickerson, 1996), becoming disconnected from the world outside of the “zone” (Schüll, 2012) of gambling play, and even becoming bankrupt or otherwise financially crippled as a result of their use (Petry, 2003; Scarf et al, 2011). Using metadata from Web of Science and Scopus databases, we analysed peer-reviewed gambling research produced in Australia, New Zealand, North America and the UK published between 1996 and 2016. Surprisingly, we found that the overwhelming of majority of articles do not specifically address EGMs as the most popular and pervasive gambling technology available. Our paper teases out some concerning implications of this finding for the interdisciplinary field of gambling studies
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