52,098 research outputs found
Gas ion laser construction for electrically isolating the pressure gauge thereof
The valve and the pressure gauge of a gas ion laser were electrically insulated from the laser discharge path by connecting them in series with the cathode of the laser. The laser cathode can be grounded and preferably is a cold cathode although a hot cathode may be used instead. The cold cathode was provided with a central aperture to which was connected both the pressure gauge and the gas pressure reservoir through the valve. This will effectively prevent electric discharges from passing either to the pressure gauge or the valve which would otherwise destroy the pressure gauge
Developing a grid computing system for commercial-off-the-shelf simulation packages
Today simulation is becoming an increasingly
pervasive technology across major business
sectors. Advances in COTS Simulation Packages
and Commercial Simulation Software have made
it easier for users to build models, often of large complex processes. These two factors combined are to be welcomed and when used correctly can be of great benefit to organisations that make use of the technology. However, it is also the case
that users hungry for answers do not always have the time, or possibly the patience, to wait for results from multiple replications and multiple experiments as standard simulation practice would demand. There is therefore a need to support this advance in the use of simulation within todayâs business with improved computing technology. Grid computing has been put forward as a potential commercial solution to this requirement. To this end, Saker Solutions and the Distributed Systems Research Group at Brunel University have developed a dedicated Grid Computing System (SakerGrid) to support the deployment of simulation models across a desktop grid of PCs. The paper identifies route taken to solve this challenging issue and suggests where the future may lie for this exciting integration of two effective but underused technologies
Apollo 16 mission report. Supplement 2: Service Propulsion system final flight evaluation
The Apollo 16 Mission was the sixteenth in a series of flights using Apollo flight hardware and included the fifth lunar landing of the Apollo Program. The Apollo 16 Mission utilized CSM 113 which was equipped with SPS Engine S/N 66 (Injector S/N 137). The engine configuration and expected performance characteristics are presented. Since previous flight results of the SPS have consistently shown the existence of a negative mixture ratio shift, SPS Engine S/N 66 was reorificed to increase the mixture ratio for this mission. The propellant unbalance for the two major engine firings is compared with the predicted unbalance. Although the unbalance at the end of the TEI burn is significantly different than the predicted unbalance, the propellant mixture ratio was well within limits. The SPS performed six burns during the mission, with a total burn duration of 575.3 seconds. The ignition time, burn duration and velocity gain for each of the six SPS burns are reported
B-field Determination from Magnetoacoustic Oscillations in kHz QPO Neutron Star Binaries: Theory and Observations
We present a method for determining the B-field around neutron stars based on
observed kHz and viscous QPO frequencies used in combination with the best-fit
optical depth and temperature of a Comptonization model. In the framework of
the transition layer QPO model, we analyze magnetoacoustic wave formation in
the layer between a neutron star surface and the inner edge of a Keplerian
disk. We derive formulas for the magnetoacoustic wave frequencies for different
regimes of radial transition layer oscillations. We demonstrate that our model
can use the QPO as a new kind of probe to determine the magnetic field
strengths for 4U 1728-42, GX 340+0, and Sco X-1 in the zone where the QPOs
occur. Observations indicate that the dependence of the viscous frequency on
the Keplerian frequency is closely related to the inferred dependence of the
magnetoacoustic wave frequency on the Keplerian frequency for a dipole magnetic
field. The magnetoacoustic wave dependence is based on a single parameter, the
magnetic moment of the star as estimated from the field strength in the
transition layer. The best-fit magnetic moment parameter is about (0.5-1)x
10^{25} G cm^3 for all studied sources. From observational data, the magnetic
fields within distances less 20 km from neutron star for all three sources are
strongly constrained to be dipole fields with the strengths 10^{7-8} G on the
neutron star surface.Comment: 10 pages, 1 figure, accepted for the Astrophysical Journal Letter
Transient performance of a turboalternator gas-bearing system
Experimental operation of gas-bearing turboalternator for spacecraft power supplie
Troubling Vulnerability: Designing with LGBT Young People's Ambivalence Towards Hate Crime Reporting
HCI is increasingly working with ?vulnerable? people yet there is a danger that the label of vulnerability can alienate and stigmatize the people such work aims to support. We report our study investigating the application of interaction design to increase rates of hate crime reporting amongst Lesbian, Gay, Bisexual and Transgender young people. During design-led workshops participants expressed ambivalence towards reporting. While recognizing their exposure to hate crime they simultaneously rejected ascription as victim as implied in the act of reporting. We used visual communication design to depict the young people?s ambivalent identities and contribute insights on how these fail and succeed to account for the intersectional, fluid and emergent nature of LGBT identities through the design research process. We argue that by producing ambiguous designed texts, alongside conventional qualitative data, we ?trouble? our design research narratives as a tactic to disrupt static and reductive understandings of vulnerability within HCI
A comparison of effectiveness of some antimotion sickness drugs using recommended and larger than recommended doses as tested in the slow rotation room
Comparison of effectiveness of antimotion sickness drugs tested in human centrifug
Turbine performance in a gas-bearing Brayton cycle turboalternator
Turbine performance in gas-bearing Brayton cycle turboalternato
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