2,759 research outputs found

    Thin-film active device investigations Final status report, 1 Dec. 1967 - 31 Aug. 1968

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    Developing evaporated gallium arsenide to determine electrical and structural transport properties for coplanar electrode, space charge limited triode

    Electrical conduction processes in thin films of cadmium sulfide

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    Electrical conduction properties of vacuum evaporated thin cadmium sulfide film

    Investigation of coincident radio-frequency drive for nondestructive readout in thin-film memories Final report

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    Coincident radio frequency drive for nondestructive readout in thin film memorie

    A Ten Year Review of Civilian Iliac Vessel Injuries from a Single Trauma Centre

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    AbstractObjectiveTo report the surgical management and outcome of iliac vessel (IV) injuries in a civilian trauma centre with a high incidence of penetrating trauma.Design, patients and methodsA retrospective record review of patients with IV injuries treated between January 2000 and December 2009.ResultsSixty nine patients, 59 with gunshot wounds, sustained 108 iliac vessel injuries. Mean revised trauma and injury severity scores was 7.06 and 28.4, respectively. Twenty nine patients required damage control laparotomy. Common or external iliac arteries were repaired by primary repair (10), temporary shunt with delayed graft (6), interposition graft (5) or ligation if limb non-viable (3). Forty-seven patients had injuries to the common or external iliac vein, 42 were ligated. Mortality was 25% and 6 survivors required amputation.ConclusionsIn a stable patient a primary arterial repair is preferred but a temporary shunt can be a life and limb saving option in the unstable patient. Ligating the common or external iliac veins is associated with a low incidence of prolonged leg swelling

    Dynamics of the magnetic and structural a -> e phase transition in Iron

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    We have studied the high-pressure iron bcc to hcp phase transition by simultaneous X-ray Magnetic Circular Dichroism (XMCD) and X-ray Absorption Spectroscopy (XAS) with an X-ray dispersive spectrometer. The combination of the two techniques allows us to obtain simultaneously information on both the structure and the magnetic state of Iron under pressure. The magnetic and structural transitions simultaneously observed are sharp. Both are of first order in agreement with theoretical prediction. The pressure domain of the transition observed (2.4 ±\pm 0.2 GPa) is narrower than that usually cited in the literature (8 GPa). Our data indicate that the magnetic transition slightly precedes the structural one, suggesting that the origin of the instability of the bcc phase in iron with increasing pressure is to be attributed to the effect of pressure on magnetism as predicted by spin-polarized full potential total energy calculations

    Optical absorption in the strong coupling limit of Eliashberg theory

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    We calculate the optical conductivity of superconductors in the strong-coupling limit. In this anomalous limit the typical energy scale is set by the coupling energy, and other energy scales such as the energy of the bosons mediating the attraction are negligibly small. We find a universal frequency dependence of the optical absorption which is dominated by bound states and differs significantly from the weak coupling results. A comparison with absorption spectra of superconductors with enhanced electron-phonon coupling shows that typical features of the strong-coupling limit are already present at intermediate coupling.Comment: 10 pages, revtex, 4 uuencoded figure

    A study of geographical distribution of geomagnetic micropulsations Final report

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    Geographical distributions of geomagnetic micropulsations continuously recorded on frequency modulated magnetic tap

    Parity Fluctuations Between Coulomb Blockaded Superconducting Islands

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    We find that if two superconducting islands of different number parity are linked by a tunnel junction the unpaired electron in the odd island has a tendency to tunnel into the even island. This process leads to fluctuations in time of the number parity of each island, giving rise to a random telegraph noise spectrum with a characteristic frequency that has an unusual temperature dependence. This new phenomenon should be observable in a Cooper-pair pump and similar single-electron tunneling devices.Comment: 4 pages, self-unpacking uuencoded gz-compressed postscript file with 3 figures included; also available at http://www.lassp.cornell.edu/janko/publications.htm

    Avalanche photodiodes for the CMS electromagnetic calorimeter

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    Avalanche photodiodes(APD's) will be used as photodetectors in the CMS barrel electromagnetic crystal calorimeter for high precision energy measurements in a hostile radiation environment. Significant progress has been made in the characteristics of these devices being expressly developed for CMS. Parameters of the final structure APD's together with demonstrations of radiation hardness and plans for quality assurance/control during the production phase are presented

    Validity of the new lifestyles NL-1000 accelerometer for measuring time spent in moderate-to-vigorous physical activity in school settings

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    Current interest in promoting physical activity in the school environment necessitates an inexpensive, accurate method of measuring physical activity in such settings. Additionally, it is recognized that physical activity must be of at least moderate intensity in order to yield substantial health benefits. The purpose of the study, therefore, was to determine the validity of the New Lifestyles NL-1000 (New Lifestyles, Inc., Lee's Summit, Missouri, USA) accelerometer for measuring moderate-to-vigorous physical activity in school settings, using the Actigraph GT1M (ActiGraph, Pensacola, Florida, USA) as the criterion. Data were collected during a cross-country run (n = 12), physical education (n = 18), and classroom-based physical activities (n = 42). Significant and meaningful intraclass correlations between methods were found, and NL-1000 estimates of moderate-to-vigorous physical activity were not meaningfully different from GT1M-estimated moderate- to-vigorous physical activity. The NL-1000 therefore shows promising validity evidence as an inexpensive, convenient method of measuring moderate-to-vigorous physical activity in school settings
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