6,476 research outputs found

    A Study of the Cyclotron Gas-Stopping Concept for the Production of Rare Isotope Beams

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    The proposed cyclotron gas-stopping scheme for the efficient thermalization of intense rare isotope beams is examined. Simulations expand on previous studies and expose many complications of such an apparatus arising from physical effects not accounted for properly in previous work. The previously proposed cyclotron gas-stopper geometry is found to have a near null efficiency, but extended simulations suggest that a device with a much larger pole gap could achieve a stopping efficiency approaching roughly 90% and at least a 10 times larger acceptance. However, some of the advantages that were incorrectly predicted in previous simulations for high intensity operation of this device are compromised.Comment: Accepted for publication in Nuclear Inst. and Methods in Physics Research,

    Workplace Homicide: The Threat Of Stranger Violence And Intimate Parter Violence In The Workplace

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    Violence in the workplace has become an important issue for the modern-day security manager. The modern-day employer continually faces a variety of threats that originate from within and beyond the confines of the workplace. As the workforce becomes more diverse, the modern-day employer will face new issues. Increasingly, employers are confronted with instances of intimate partner violence (IPV) at the workplace. The context of such threats creates unique circumstances in terms of how employers should respond. The modern-day employers\u27 responsibility is evolving into areas that were once thought to be beyond the purview of their duties. Having knowledge of the increased risk of IPV associated with women at the workplace, understanding the various practices and policies that help prevent workplace violence, and recognizing the characteristics of the workplace stalker can well serve the modern-day employer when responding to IPV at work

    The Effect Of Gendered Spaces On The Gender Gap In Victimization: Implications For Private And Public Security

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    This research examines the gender gap in crime and how gendered spaces play a role in decreasing this gap. The gender gap in crime explains that men and women experience victimization at different rates. Gendered spaces are spaces in society that are designated for men and women. Routine activity theory and gendered spaces are two theoretical perspectives used in the study to examine how gender influences the routine activities of people and how this in turn creates gendered spaces and subsequent victimization based on perceptions an offender has of a women or men. This study utilizes secondary data from the 2012 National Incident-Based Reporting System. The sample size in the study consisted of 243,096 crime victims. Routine activity theory and gendered spaces partially explains the victimization experiences of men and women. Women were more likely to be victimized in feminine gendered spaces (e.g., banks, grocery stores, and shopping centers) compared to other locations. Women were also more likely to suffering a robbery victimization in these feminine spaces compared to other locations. Women were also more likely to be victimized by a stranger in feminine gendered spaces compared to other locations

    Burial diagenesis model for the Macumber Formation on Cape Breton Island - implications for the tectonic evolution of the Windsor Group

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    The Macumber Formation, a finely laminated limestone consisting of two thin units, represents a key stratigraphic marker at the base of the Visean Windsor Group. On Cape Breton Island the formation hosts numerous Pb-Zn occurrences, and its upper boundary is in contact with rocks ranging in age from Visean (early Carboniferous) to Westphalian (middle Carboniferous), the origin of the stratigraphic omissions being debatable. This first inorganic diagenesis study identifies nine post-depositionat processes, including the stabilization of marine components, and evaporite and anhedral calcite precipitation. The δ18OPDB (-13.0 to 2.0%o), 87Sr/86Sr (0.7076 to 0.7079) and [Sr] (50 to 10000 ppm) of samples, including upper and basal whole-rock units and anhedral calcite cements, show two trends enveloping the entire field of data. The trends suggest that an evaporite-derived, non-radiogenic fluid and a clastic-derived radiogenic fluid mixed and interacted with the limestone sediments, in a progressively deeper burial environment. The evaporite-derived fluid mostly imprinted the top unit of the formation. The field investigations, microscope observations and geochemical results do not indicate a meteoric overprint as would be expected if an unconformity existed along the top of the formation. The burial history documented here, and the presence of fibrous calcite indicating bedding parallel shearing, support a detachment model to explain the stratigraphic omissions within the Windsor Group. RÉSUMÉ La Formation de Macumber, composeé de calcaires fins en deux minces unités, représente un marqueur stratigraphique crucial à la base du Groupe de Windsor. À l’ile du Cap Breton, la formation encaisse plusieurs indices Pb-Zn et constitue la limite inférieure d'une série d'omissions stratigraphiques à l'intérieur du Groupe de Windsor, l'origine-desquelles est fortement débattue. Cette première investigation de la diagenèse inorganique place neuf processus en une succession post-dépositionnelle incluant la stabilisation des éléments marins, et la précipitation d'évaporites et de ciments calcitiques anédriques. Les δ18OPDB (-13.0 to 2.0%o), 87Sr/86Sr (0.7076 to 0.7079) et [Sr] (50 to 10000 ppm) de microéchantillons des unites inférieures et supérieures, et de ciments anédriques montrent deux tendences envcloppant l’ensemble des résultats. Ces tendences suggèrent qu'un fluide non-radiogéltest;nique, eévaporitique et un fluide radiogénique dérivé de roches clastiques, auraicnt affecté les sédiments calcaires au cours de leur enfouissement progressif plus profond. Le fluide évaporitique aurait principalement affecté l'unité supérieure de la formation. Les données de terrain, les observation microscopiqucs et les résultats géochimiques n'indiquent pas l'empreinte météorique attendue si une discordance existait au sommet de la formation. L'histoirc diagénétique ici documentée, ainsi que l'existence de calcite fibreuse développée le long de plans de cisaitlement parallèles au litage supportent le modele de détachement pour expliquer les omissions stratigraphiques du Groupe de Windsor

    Ultrastable CO2 Laser Trapping of Lithium Fermions

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    We demonstrate an ultrastable CO2 laser trap that provides tight confinement of neutral atoms with negligible optical scattering and minimal laser-noise- induced heating. Using this method, fermionic 6Li atoms are stored in a 0.4 mK deep well with a 1/e trap lifetime of 300 sec, consistent with a background pressure of 10^(-11) Torr. To our knowledge, this is the longest storage time ever achieved with an all-optical trap, comparable to the best reported magnetic traps.Comment: 4 pages using REVTeX, 1 eps figur
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