956 research outputs found

    State-of-the-art survey of dissimilar metal joining by solid state welding

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    State-of-the-art of dissimilar metal joining by solid state diffusion bonding and roll and press welding, emphasizing stainless steel and aluminum allo

    A pragmatic cluster randomized controlled trial of an educational intervention for GPs in the assessment and management of depression

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    Background. General practitioners (GPs) can be provided with effective training in the skills to manage depression. However, it remains uncertain whether such training achieves health gain for their patients. Method. The study aimed to measure the health gain from training GPs in skills for the assessment and management of depression. The study design was a cluster randomized controlled trial. GP participants were assessed for recognition of psychological disorders, attitudes to depression, prescribing patterns and experience of psychiatry and communication skills training. They were then randomized to receive training at baseline or the end of the study. Patients selected by GPs were assessed at baseline, 3 and 12 months. The primary outcome was depression status, measured by HAM-D. Secondary outcomes were psychiatric symptoms (GHQ-12) quality of life (SF-36), satisfaction with consultations, and health service use and costs. Results. Thirty-eight GPs were recruited and 36 (95%) completed the study. They selected 318 patients, of whom 189 (59%) were successfully recruited. At 3 months there were no significant differences between intervention and control patients on HAM-D, GHQ-12 or SF-36. At 12 months there was a positive training effect in two domains of the SF-36, but no differences in HAM-D, GHQ-12 or health care costs. Patients reported trained GPs as somewhat better at listening and understanding but not in the other aspects of satisfaction. Conclusions. Although training programmes may improve GPs' skills in managing depression, this does not appear to translate into health gain for depressed patients or the health service

    Limit on the Temporal Variation of the Fine-Structure Constant Using Atomic Dysprosium

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    Over a period of eight months, we have monitored transition frequencies between nearly degenerate, opposite-parity levels in two isotopes of atomic dysprosium (Dy). These transition frequencies are highly sensitive to temporal variation of the fine-structure constant (α\alpha) due to relativistic corrections of large and opposite sign for the opposite-parity levels. In this unique system, in contrast to atomic-clock comparisons, the difference of the electronic energies of the opposite-parity levels can be monitored directly utilizing a radio-frequency (rf) electric-dipole transition between them. Our measurements show that the frequency variation of the 3.1-MHz transition in 163^{163}Dy and the 235-MHz transition in 162^{162}Dy are 9.0±\pm6.7 Hz/yr and -0.6±\pm6.5 Hz/yr, respectively. These results provide a value for the rate of fractional variation of α\alpha of (−2.7±2.6)×10−15(-2.7\pm2.6)\times 10^{-15} yr−1^{-1} (1 σ\sigma) without any assumptions on the constancy of other fundamental constants, indicating absence of significant variation at the present level of sensitivity.Comment: 4 pages, 2 figure

    Investigation of a single-photon source based on quantum interference

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    We report on an experimental investigation of a single-photon source based on a quantum interference effect first demonstrated by Koashi, Matsuoka, and Hirano [Phys. Rev. A 53, 3621 (1996)]. For certain types of measurement-based quantum information processing applications this technique may be useful as a high rate, but random, source of single photons.Comment: Submitted to the New J. Phys. Focus Issue on "Measurement-based quantum information processing

    Transpiration cooling system development for reentry vehicles

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    Transpiration cooling system for reentry vehicle
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