41,765 research outputs found
Circuit minimizes current drain caused by neon indicator lamps
Circuit lights neon lamp by back leakage current of the driving transistor, rather than by the transistors saturation or ''on-state'' current, thereby eliminating lowering of the voltage necessary for indication. Circuit has operating speed greater than indication circuit using a saturation principle and aids in power rationing
Process for the leaching of AP from propellant
A method for the recovery of ammonium perchlorate from waste solid rocket propellant is described wherein shredded particles of the propellant are leached with an aqueous leach solution containing a low concentration of surface active agent while stirring the suspension
Classical Extended Conformal Algebras Associated with Constrained KP Hierarchy
We examine the conformal property of the second Hamiltonian structure of
constrained KP hierarchy derived by Oevel and Strampp. We find that it
naturallygives a family of nonlocal extended conformal algebras. We give two
examples of such algebras and find that they are similar to Bilal's V algebra.
By taking a gauge transformation one can map the constrained KP hierarchy to
Kuperschmidt's nonstandard Lax hierarchy. We consider the second Hamiltonian
structure in this representation. We show that after mapping the Lax operator
to a pure differential operator the second structure becomes the sum of the
second and the third Gelfand-Dickey brackets defined by this differential
operator. We show that this Hamiltonian structure defines the W-U(1)-Kac-Moody
algebra by working out its conformally covariant form.Comment: NHCU-HEP-94-28, 19 pages (Plain TeX
The inter-relation between policy and practice for transitions from hospital to home: An ethnographic case study in England’s National Health Service
© 2014 Shaw et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.No abstract available (poster presentation)
Device and method for frictionally testing materials for ignitability
Test apparatus for determining ignition characteristics of various metal in oxidizer environments simulating operating conditions for materials is invented. The test apparatus has a chamber through which the oxidizing agent flows, and means for mounting a stationary test sample therein, a powered, rotating shaft in the chamber rigidly mounts a second test sample. The shaft is axially movable to bring the samples into frictional engagement and heated to the ignition point. Instrumentation connected to the apparatus provides for observation of temperatures, pressures, loads on and speeds of the rotating shaft, and torques whereby components of stressed oxygen systems can be selected which will avoid accidental fires under working conditions
Turbofan blade stresses induced by the flow distortion of a VTOL inlet at high angles of attack
A 51-cm-diameter turbofan with a tilt-nacelle VTOL inlet was tested in the Lewis Research Center's 9- by 15-Ft Low Speed Wind Tunnel at velocities up to 72 m/s and angles of attack up to 120 deg. Fan-blade vibratory stress levels were investigated over a full aircraft operating range. These stresses were due to inlet air flow distortion resulting from (1) internal flow separation in the inlet, and (2) ingestion of the exterior nacelle wake. Stress levels are presented, along with an estimated safe operating envelope, based on infinite blade fatigue life
VSTOL tilt nacelle aerodynamics and its relation to fan blade stresses
A scale model of a VSTOL tilt nacelle with a 0.508 m single stage fan was tested in a low speed wind tunnel to ascertain inlet aerodynamic and fan aeromechanical performance over the low speed flight envelope. Fan blade stress maxima occurred at discrete rotational speeds corresponding to integral engine order vibrations of the first flatwise bending mode. Increased fan blade stress levels coincided with internal boundary layer separation but became severe only when the separation location had progressed to the entry lip region of the inlet
Ethnic parity in labour market outcomes for benefit claimants
A significant gap exists in the UK between the employment rate for Ethnic Minorities and that for
Whites. From a policy perspective, it is important to know whether this gap is due to differences in
the characteristics of White and Ethnic Minority groups (which reduce the employability of Ethnic
Minority groups relative to Whites) or whether it results from some form of discriminatory behaviour
in the labour market. In this paper, we use administrative data to estimate ethnic differences in
employment and benefit receipt amongst individuals who began claiming a Jobcentre Plus benefit
in 2003. In contrast to much of the previous UK literature, we use a number of different quantitative
techniques to estimate this gap, and show that in a lot of cases the estimates obtained are very
sensitive to the techniques used. We argue that for the questions we are interested in and the data
we have, propensity score matching methods are the most robust approach to estimating ethnic
parity. We compare this preferred approach with estimates derived using alternative approaches
commonly used in the literature (generally regression-based techniques) to determine the extent to
which more straightforward methods are able to replicate those produced by matching. In many
cases, it turns out not to be possible to calculate satisfactory quantitative estimates even with
matching techniques: the characteristics of Whites and Ethnic Minorities are simply too different
before the Jobcentre Plus intervention to reliably estimate the parameters of interest. Moreover, for
a number of the groups, results seem to be very sensitive to the methodology used. This calls into
question previous results based on simple regression techniques, which are likely to hide the fact
that observationally different ethnic groups are de facto being compared on the basis of parametric
extrapolations. Two groups for which it was possible to calculate reasonably reliable results are
incapacity benefit (IB) and income support (IS). For these groups we find that large and significant
raw penalties almost always disappear once we appropriately control for pre-inflow background
and labour market characteristics. There is also a good degree of consistency across
methodologies
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