Laser extensometer

A drift compensated and intensity averaged extensometer for measuring the diameter or other properties of a substantially cylindrical sample based upon the shadow of the sample is described. A beam of laser light is shaped to provide a beam with a uniform intensity along an axis normal to the sample. After passing the sample, the portion of the beam not striking said sample is divided by a beam splitter into a reference signal and a measurement signal. Both of these beams are then chopped by a light chopper to fall upon two photodiode detectors. The resulting ac currents are rectified and then divided into one another, with the final output being proportional to the size of the sample shadow

An approach to market analysis for lighter than air transportation of freight

An approach is presented to marketing analysis for lighter than air vehicles in a commercial freight market. After a discussion of key characteristics of supply and demand factors, a three-phase approach to marketing analysis is described. The existing transportation systems are quantitatively defined and possible roles for lighter than air vehicles within this framework are postulated. The marketing analysis views the situation from the perspective of both the shipper and the carrier. A demand for freight service is assumed and the resulting supply characteristics are determined. Then, these supply characteristics are used to establish the demand for competing modes. The process is then iterated to arrive at the market solution

Personnel Practices in Japanese Government

The views expressed in this paper are those of the authors and do not necessarily represent those of the Federal Communications Commission, the U.S. Nuclear Regulatory Commission, or the U.S. Government.This paper examines key aspects of Japanese Government personnel practices, and draws comparisons with the practices in the U.S. civil service and, as appropriate, with other U.S. models. Particular reference is made to the practices of two major agencies in Japan, the Ministry of International Trade and Industry (MITI) and the Ministry of Posts and Telecommunications (MPT). As appropriate, selected government businesses practices other than personnel practices are noted

Effect of a moderate-intensity demonstration walk on accuracy of physical activity self-report.

Background/Objective:Providing a demonstration of a 10-minute bout of moderate-to-vigorous intensity physical activity (MVPA) immediately prior to subjective reporting of MVPA could influence self-reported activity by calibrating both duration and intensity. We assessed the effect of a demonstration of MVPA on subsequent MVPA recall, and explored whether this improved agreement with objective measures of MVPA. Methods:A total of 846 individuals participated in four different physical activity interventions; two of which included a 10-minute moderate-intensity demonstration walk on a treadmill at baseline and 6-month visits immediately prior to reporting MVPA. Participants from three studies also wore accelerometers during the week overlapping with self-reported MVPA. Results:Overall, those completing the demonstration walk reported significantly fewer minutes of MVPA per week at baseline (b = -11.69, standard error = 2.53, p < 0.01). The effect of the demonstration walk at 6 months was not significant (p = 0.06). Correlations with accelerometers at baseline were higher in the two studies with the demonstration walk (ρ = 0.28, 0.26) than the study without (ρ = 0.04). Correlations with accelerometers increased overall from baseline to follow-up. Conclusion:A 10-minute demonstration of MVPA was associated with reporting fewer minutes of MVPA and improved agreement with objective PA measures at baseline. These findings support combining self-report PA assessments with hands-on MVPA demonstrations

Lifetimes and Gj factors in excited states of chromium. Hyperfine structure of Cr53

Electronic and nuclear properties of excited chromium isotopes using level crossing and double resonance spectroscopy technique

Cochrane dementia group turns 21—older and (slightly) wiser

This invited editorial describes the achievements of the last 21 years of the Cochrane Dementia and Cognitive Improvement Group (DR Quinn is the coordinating editor of the group)

The Resonant Exchange Qubit

We introduce a solid-state qubit in which exchange interactions among confined electrons provide both the static longitudinal field and the oscillatory transverse field, allowing rapid and full qubit control via rf gate-voltage pulses. We demonstrate two-axis control at a detuning sweet-spot, where leakage due to hyperfine coupling is suppressed by the large exchange gap. A {\pi}/2-gate time of 2.5 ns and a coherence time of 19 {\mu}s, using multi-pulse echo, are also demonstrated. Model calculations that include effects of hyperfine noise are in excellent quantitative agreement with experiment

Superconducting, Insulating, and Anomalous Metallic Regimes in a Gated Two-Dimensional Semiconductor-Superconductor Array

The superconductor-insulator transition in two dimensions has been widely investigated as a paradigmatic quantum phase transition. The topic remains controversial, however, because many experiments exhibit a metallic regime with saturating low-temperature resistance, at odds with conventional theory. Here, we explore this transition in a novel, highly controllable system, a semiconductor heterostructure with epitaxial Al, patterned to form a regular array of superconducting islands connected by a gateable quantum well. Spanning nine orders of magnitude in resistance, the system exhibits regimes of superconducting, metallic, and insulating behavior, along with signatures of flux commensurability and vortex penetration. An in-plane magnetic field eliminates the metallic regime, restoring the direct superconductor-insulator transition, and improves scaling, while strongly altering the scaling exponent

Directed and elliptic flow in heavy ion collisions from Ebeam=90E_{\rm beam}=90 MeV/nucleon to Ec.m.=200E_{\rm c.m.}=200 GeV/nucleon

Recent data from the NA49 experiment on directed and elliptic flow for Pb+Pb reactions at CERN-SPS are compared to calculations with a hadron-string transport model, the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. The rapidity and transverse momentum dependence of the directed and elliptic flow, i.e. $v_1$ and $v_2$, are investigated. The flow results are compared to data at three different centrality bins. Generally, a reasonable agreement between the data and the calculations is found. Furthermore, the energy excitation functions of $v_1$ and $v_2$ from $E_{\rm beam}=90A$ MeV to $E_{\rm cm}=200A$ GeV are explored within the UrQMD framework and discussed in the context of the available data. It is found that, in the energy regime below $E_{\rm beam}\leq 10A$ GeV, the inclusion of nuclear potentials is necessary to describe the data. Above $40A$ GeV beam energy, the UrQMD model starts to underestimate the elliptic flow. Around the same energy the slope of the rapidity spectra of the proton directed flow develops negative values. This effect is known as the third flow component ("antiflow") and cannot be reproduced by the transport model. These differences can possibly be explained by assuming a phase transition from hadron gas to quark gluon plasma at about $40A$ GeV.Comment: 19 pages, minor changes and modified title as published in PR