504 research outputs found
Effect of Off-Body Laser Discharge on Drag Reduction of Hemisphere Cylinder in Supersonic Flow
The interaction of an off-body laser discharge with a hemisphere cylinder in supersonic flow is investigated. The objectives are 1) experimental determination of the drag reduction and energetic efficiency of the laser discharge, and 2) assessment of the capability for accurate simulation of the interaction. The combined computational and experimental study comprises two phases. In the first phase, laser discharge in quiescent air was examined. The temporal behavior of the shock wave formed by the laser discharge was compared between experiment and simulation and good agreement is observed. In the second phase, the interaction of the laser discharge with a hemisphere cylinder was investigated numerically. Details of the pressure drag reduction and the physics of the interaction of the heated region with the bow shock are included. The drag reduction due to this interaction persisted for about five characteristic times where one characteristic time represents the time for the flow to move a distance equal to the hemisphere radius. The energetic efficiency of laser discharge for the case with 50 mJ energy absorbed by the gas is calculated as 3.22
Appointments, pay and performance in UK boardrooms by gender
This article uses UK data to examine issues regarding the scarcity of women in boardroom positions. The article examines appointments, pay and any associated productivity effects deriving from increased diversity. Evidence of gender-bias in the appointment of women as non-executive directors is found together with mixed evidence of discrimination in wages or fees paid. However, the article finds no support for the argument that gender diverse boards enhance corporate performance. Proposals in favour of greater board diversity may be best structured around the moral value of diversity, rather than with reference to an expectation of improved company performance
Efficient analysis in planet transit surveys
With the growing number of projects dedicated to the search for extrasolar
planets via transits, there is a need to develop fast, automatic, robust
methods with a statistical background in order to efficiently do the analysis.
We propose a modified analysis of variance (AoV) test particularly suitable for
the detection of planetary transits in stellar light curves. We show how
savings of labor by a factor of over 10 could be achieved by the careful
organization of computations. Basing on solid analytical statistical
formulation, we discuss performance of our and other methods for different
signal-to-noise and number of observations.Comment: 7 pages, to be published in MNRAS, downloadable software from
http://www.camk.edu.pl/~alex/#softwar
Patient Attitudes and Participation in Hand Co-Washing in an Outpatient Clinic Before and After a Prompt
Despite recent national emphasis, outpatient hand washing can be less than optimal. We tested a new approach involving both patient and physician hand washing. The study consisted of 384 questionnaires, 184 from phase 1 and 200 from phase 2. Patients stated doctors washed their hands 96.6% before examining them pre-intervention and 99.5% of the time post-intervention. Patients endorsed the importance of hand washing 98.7% of the time. “Co-washing” may offer a process to increase the practice of hand washing and decrease infection risk
Getting It on Record: Issues and Strategies for Ethnographic Practice in Recording Studios
The recording studio has been somewhat neglected as a site for ethnographic fieldwork in the field of ethno-musicology and, moreover, the majority of published studies tend to overlook the specific concerns faced by the researcher within these contexts. Music recording studios can be places of creativity, artistry, and collaboration, but they often also involve challenging, intimidating, and fractious relations. Given that recording studios are, first and foremost, concerned with documenting musicians’ performances, we discuss the concerns of getting studio interactions “on record” in terms of access, social relations, and methods of data collection. This article reflects on some of the issues we faced when conducting our fieldwork within British music recording facilities and makes suggestions based on strategies that we employed to address these issues
Plasmonics-enhanced and optically modulated delivery of gold nanostars into brain tumor
Plasmonics-active gold nanostars exhibiting strong imaging contrast and efficient photothermal transduction were synthesized for a novel pulsed laser-modulated plasmonics-enhanced brain tumor microvascular permeabilization. We demonstrate a selective, optically modulated delivery of nanoprobes into the tumor parenchyma with minimal off-target distribution
Kepler eclipsing binary stars. VII. the catalogue of eclipsing binaries found in the entire Kepler data set
The primary Kepler Mission provided nearly continuous monitoring of ~200,000 objects with unprecedented photometric precision. We present the final catalog of eclipsing binary systems within the 105 deg2 Kepler field of view. This release incorporates the full extent of the data from the primary mission (Q0-Q17 Data Release). As a result, new systems have been added, additional false positives have been removed, ephemerides and principal parameters have been recomputed, classifications have been revised to rely on analytical models, and eclipse timing variations have been computed for each system. We identify several classes of systems including those that exhibit tertiary eclipse events, systems that show clear evidence of additional bodies, heartbeat systems, systems with changing eclipse depths, and systems exhibiting only one eclipse event over the duration of the mission. We have updated the period and galactic latitude distribution diagrams and included a catalog completeness evaluation. The total number of identified eclipsing and ellipsoidal binary systems in the Kepler field of view has increased to 2878, 1.3% of all observed Kepler targets
Photometric transit search for planets around cool stars from the western Italian Alps: A pilot study
[ABRIDGED] In this study, we set out to a) demonstrate the sensitivity to <4
R_E transiting planets with periods of a few days around our program stars, and
b) improve our knowledge of some astrophysical properties(e.g., activity,
rotation) of our targets by combining spectroscopic information and our
differential photometric measurements. We achieve a typical nightly RMS
photometric precision of ~5 mmag, with little or no dependence on the
instrumentation used or on the details of the adopted methods for differential
photometry. The presence of correlated (red) noise in our data degrades the
precision by a factor ~1.3 with respect to a pure white noise regime. Based on
a detailed stellar variability analysis, a) we detected no transit-like events;
b) we determined photometric rotation periods of ~0.47 days and ~0.22 days for
LHS 3445 and GJ 1167A, respectively; c) these values agree with the large
projected rotational velocities (~25 km/s and ~33 km/s, respectively) inferred
for both stars based on the analysis of archival spectra; d) the estimated
inclinations of the stellar rotation axes for LHS 3445 and GJ 1167A are
consistent with those derived using a simple spot model; e) short-term,
low-amplitude flaring events were recorded for LHS 3445 and LHS 2686. Finally,
based on simulations of transit signals of given period and amplitude injected
in the actual (nightly reduced) photometric data for our sample, we derive a
relationship between transit detection probability and phase coverage. We find
that, using the BLS search algorithm, even when phase coverage approaches 100%,
there is a limit to the detection probability of ~90%. Around program stars
with phase coverage >50% we would have had >80% chances of detecting planets
with P0.5%, corresponding to minimum
detectable radii in the range 1.0-2.2 R_E. [ABRIDGED]Comment: 23 pages, 17 figures, 7 tables. Accepted for publication in MNRA
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