1,438 research outputs found

    Generation of long time creep data on refractory alloys at elevated temperatures Quarterly report, 26 Oct. - 26 Dec. 1966

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    Long-time creep data on refractory metal alloys for advanced space power system

    Fractional exclusion statistics and shot noise in ballistic conductors

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    We study the noise properties of ballistic conductors with carriers satisfying fractional exclusion statistics. To test directly the nature of exclusion statistics we found that systems under weakly degenerate conditions should be considered. Typical of these systems is that the chemical potential, μ\mu is in the thermal range μ<3kBT|\mu |<3k_{B}T. In these conditions the noise properties under current saturation are found to depend upon the statistical parameter gg, displaying suppressed shot noise for 1/2g11/2\leq g\leq 1, and enhanced shot noise for 0<g<1/20<g<1/2, according to the attractive or repulsive nature of the carrier exclusion statistics.Comment: 6 pages, 5 figures, accepted for publication in Phys. Rev.

    Topology of Minimal Walking Technicolor

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    We perform a lattice study of the topological susceptibility and instanton size distribution of the \su{2} gauge theory with two adjoint Dirac fermions (also known as Minimal Walking Technicolor), which is known to be in the conformal window. In the theory deformed with a small mass term, by drawing a comparison with the pure gauge theory, we find that topological observables are decoupled from the fermion dynamics. This provides further evidence for the infrared conformality of the theory. A study of the instanton size distribution shows that this quantity can be used to detect the onset of finite size effects.Comment: An error in the analysis has been corrected that does not affect the result. Discussions have been expanded, comments and references added, conclusions unchanged. Version to appear on EPJ

    Critical speed estimated by statistically appropriate fitting procedures.

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    Intensity domains are recommended when prescribing exercise. The distinction between heavy and severe domains is made by the critical speed (CS), therefore requiring a mathematically accurate estimation of CS. The different model variants (distance versus time, running speed versus time, time versus running speed, and distance versus running speed) are mathematically equivalent. Nevertheless, error minimization along the correct axis is important to estimate CS and the distance that can be run above CS (d'). We hypothesized that comparing statistically appropriate fitting procedures, which minimize the error along the axis corresponding to the properly identified dependent variable, should provide similar estimations of CS and d' but that different estimations should be obtained when comparing statistically appropriate and inappropriate fitting procedure. Sixteen male runners performed a maximal incremental aerobic test and four exhaustive runs at 90, 100, 110, and 120% of their peak speed on a treadmill. Several fitting procedures (a combination of a two-parameter model variant and regression analysis: weighted least square) were used to estimate CS and d'. Systematic biases (P &lt; 0.001) were observed between each pair of fitting procedures for CS and d', even when comparing two statistically appropriate fitting procedures, though negligible, thus corroborating the hypothesis. The differences suggest that a statistically appropriate fitting procedure should be chosen beforehand by the researcher. This is also important for coaches that need to prescribe training sessions to their athletes based on exercise intensity, and their choice should be maintained over the running seasons