45,345 research outputs found

    Self-healing fuse

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    Fast-acting current limiting device provides current overload protection for vulnerable circuit elements and then re-establishes conduction path within milliseconds. Fuse can also perform as fast-acting switch to clear transient circuit overloads. Fuse takes advantage of large increase in electrical resistivity that occurs when liquid metal vaporizes

    A qualitative study exploring why adults with intellectual disabilities and obesity want to lose weight and views of their carers

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    Background: Obesity is more prevalent in adults with intellectual disabilities (ID) compared to the general population. Motivations for weight loss may influence engagement with weight management programmes and have only been studied in adults without ID. Aims: To determine reasons given by adults with ID and obesity for seeking weight loss and whether these reasons differ from those of their carers. Methods: Prior to a multi-component weight management intervention, participants were asked “why do you want to lose weight?” Carers were asked their views and these were compared to the answers given by the adult with ID. Responses were themed. The Fisher’s Exact analysis was used to test for any relationship between reasons for seeking weight loss and participants’ level of ID, age, gender and BMI. Results: Eighteen men and 32 women; age 41.6 SD 14.6 years; BMI 40.8 SD 7.5 kg/m2; Level ID Mild (28 %), Moderate (42 %), Severe (22 %), Profound (8 %). Eleven were unable to respond. Six themes emerged; Health; Fitness / Activity / Mobility; Appearance / Clothes; Emotional / Happiness; For Others; Miscellaneous. The most frequent reason given overall and by women was “appearance.” Carers cited “health” most frequently and “appearance” least, rarely agreeing with participants. “Health” was given as a reason more from older adults and those with milder ID. No statistically significant associations were found between reasons for seeking weight loss and BMI age, gender or level of ID but the differing views of adults with ID and their carers were clear. Conclusions: Views of adults with obesity and mild or moderate ID can be collected. The opposing views of adults and their carers may affect motivation for weight loss

    Self-healing fuse development

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    The mercury-filled self-healing fuses developed for this program afford very good protection from circuit faults with rapid reclosure. Fuse performance and design parameters have been characterized. Life tests indicate a capability of 500 fuse operations. Fuse ratings are 150 v at 5, 15, 25 and 50 circuit A. A series of sample fuses using alumina and beryllia insulation have been furnished to NASA for circuit evaluation

    On the Formation of Galaxy Halos: Comparing NGC 5128 and the Local Group Members

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    The metallicity distribution function (MDF) for the old red-giant stars in the halo of NGC 5128, the nearest giant elliptical galaxy, is virtually identical with the MDF for the old-disk stars in the LMC and also strongly resembles the halo MDF in M31. These galaxies all have high mean halo metallicities ( ~ -0.4$) with very small proportions of low-metallicity stars. These observations reinforce the view that metal-rich halos are quite normal for large galaxies of all types. Such systems are unlikely to have built up by accretion of pre-existing, gas-free small satellite galaxies, unless these satellites had an extremely shallow mass distribution (d log N / d log M > -1). We suggest that the halo of NGC 5128 is more likely to have assembled from hierarchical merging of gas-rich lumps in which the bulk of star formation took place during or after the merger stage.Comment: 10 pages, LaTeX, plus 3 figures in separate postscript files; Astronomical Journal, in press for December 200

    Correction to: The hidden therapist: evidence for a central role of music in psychedelic therapy.

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    The article The hidden therapist: evidence for a central role of music in psychedelic therapy, written by Mendel Kaelen, Bruna Giribaldi, Jordan Raine, Lisa Evans, Christopher Timmerman, Natalie Rodriguez, Leor Roseman, Amanda Feilding, David Nutt, Robin Carhart-Harris, was originally published electronically on the publisher's internet portal

    Surface spin-flop and discommensuration transitions in antiferromagnets

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    Phase diagrams as a function of anisotropy DD and magnetic field HH are obtained for discommensurations and surface states for an antiferromagnet in which HH is parallel to the easy axis, by modeling it using the ground states of a one-dimensional chain of classical XY spins. A surface spin-flop phase exists for all DD, but the interval in HH over which it is stable becomes extremely small as DD goes to zero. First-order transitions, separating different surface states and ending in critical points, exist inside the surface spin-flop region. They accumulate at a field HH' (depending on DD) significantly less than the value HSFH_{SF} for a bulk spin-flop transition. For H<H<HSFH' < H < H_{SF} there is no surface spin-flop phase in the strict sense; instead, the surface restructures by, in effect, producing a discommensuration infinitely far away in the bulk. The results are used to explain in detail the phase transitions occurring in systems consisting of a finite, even number of layers.Comment: Revtex 17 pages, 15 figure

    On the sign of the neutrino asymmetry induced by active-sterile neutrino oscillations in the early Universe

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    We deal with the problem of the final sign of the neutrino asymmetry generated by active-sterile neutrino oscillations in the Early Universe solving the full momentum dependent quantum kinetic equations. We study the parameter region 102<δm2/eV210310^{-2} \stackrel{<}{\sim} |\delta m^2|/eV^2\le 10^3. For a large range of sin22θ0\sin^2 2\theta_0 values the sign of the neutrino asymmetry is fixed and does not oscillate. For values of mixing parameters in the region 106<sin22θ0<3×104(eV2/δm2)10^{-6}\stackrel{<}{\sim}\sin^{2}2\theta_{0}\stackrel{<}{\sim} 3\times 10^{-4} ({\rm eV}^{2}/|\delta m^{2}|), the neutrino asymmetry appears to undergo rapid oscillations during the period where the exponential growth occurs. Our numerical results indicate that the oscillations are able to change the neutrino asymmetry sign. The sensitivity of the solutions and in particular of the final sign of lepton number to small changes in the initial conditions depends whether the number of oscillations is high enough. It is however not possible to conclude whether this effect is induced by the presence of a numerical error or is an intrinsic feature. As the amplitude of the statistical fluctuations is much lower than the numerical error, our numerical analysis cannot demonstrate the possibility of a chaotical generation of lepton domains. In any case this possibility is confined to a special region in the space of mixing parameters and it cannot spoil the compatibility of the νμνs\nu_{\mu}\leftrightarrow\nu_{s} solution to the neutrino atmospheric data obtained assuming a small mixing of the νs\nu_{s} with an eVτ{\rm eV}-\tau neutrino.Comment: Typo's corrected, accepted for publication in Phys.Rev.

    Tide and Tidal Current Prediction by High Speed Digital Computer

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    The Tide and Tidal Current Tables of the U. S. Coast and Geodetic Survey for 1966 have been computed and edited by a digital computer, the IBM 7094. Prediction by this method is found to be more economical and expedient than by the tide prediction machine in use since 1910. The shift to digital predictions has been gradual. The first program was prepared in 1956 to predict hourly tide heights only, for use in storm surge research. The greatest advantage to digital prediction at that time was the elimination of the hour or more required to set up a new problem on the tide predicting machine, when highly accurate predictions were needed for many short periods. Later, as more efficient computers became available, this program was expanded to include the computation of highs and lows, editing the data in a form suitable for publication and the complete prediction and editing of the tidal current tables. The existing program, to a large degree, reproduced the same calculations formerly made on the analogue tide predicting machine, and with comparable accuracy. The greater versatility of this system invites experimentation, not feasible with the analogue computer. Thus, it is expected that in the long run the switch to digital calculations will lead to an increase in the accuracy of the predictions for stations having complex tide problems. The program grew through the years, and is not the most efficient that could be prepared today. Nevertheless, it appears doubtful that the improved efficiency would justify a complete revision. This report gives a general description of the program, the input data specifications and samples of the results

    Nonequilibrium statistical mechanics of shear flow: invariant quantities and current relations

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    In modeling nonequilibrium systems one usually starts with a definition of the microscopic dynamics, e.g., in terms of transition rates, and then derives the resulting macroscopic behavior. We address the inverse question for a class of steady state systems, namely complex fluids under continuous shear flow: how does an externally imposed shear current affect the microscopic dynamics of the fluid? The answer can be formulated in the form of invariant quantities, exact relations for the transition rates in the nonequilibrium steady state, as discussed in a recent letter [A. Baule and R. M. L. Evans, Phys. Rev. Lett. 101, 240601 (2008)]. Here, we present a more pedagogical account of the invariant quantities and the theory underlying them, known as the nonequilibrium counterpart to detailed balance (NCDB). Furthermore, we investigate the relationship between the transition rates and the shear current in the steady state. We show that a fluctuation relation of the Gallavotti-Cohen type holds for systems satisfying NCDB.Comment: 24 pages, 11 figure

    TGRS Observations of Positron Annihilation in Classical Novae

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    The TGRS experiment on board the Wind spacecraft has many advantages as a sky monitor --- broad field of view (~2 pi) centered on the south ecliptic pole), long life (1994-present), and stable low background and continuous coverage due to Wind's high altitude high eccentricity orbit. The Ge detector has sufficient energy resolution (3-4 keV at 511 keV) to resolve a cosmic positron annihilation line from the strong background annihilation line from beta-decays induced by cosmic ray impacts on the instrument, if the cosmic line is Doppler-shifted by this amount. Such lines (blueshifted) are predicted from nucleosynthesis in classical novae. We have searched the entire TGRS database for 1995-1997 for this line, with negative results. In principle such a search could yield an unbiased upper limit on the highly-uncertain Galactic nova rate. We carefully examined the times around the known nova events during this period, also with negative results. The upper limit on the nova line flux in a 6-hr interval is typically <3.8 E-3 photon/(cm2 s) at 4.6 sigma. We performed the same analysis for times around the outburst of Nova Vel 1999, obtaining a worse limit due to recent degradation of the detector response caused by cosmic ray induced damage.Comment: 5 pp. inc. 3 figs. Proc. 5th Compton Symposium (AIP Conf. Series), ed. M. McConnell, in pres
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