59,738 research outputs found
Gauge-invariant Formulation of the Second-order Cosmological Perturbations
Gauge invariant treatments of the second order cosmological perturbation in a
four dimensional homogeneous isotropic universe filled with the perfect fluid
are completely formulated without any gauge fixing. We derive all components of
the Einstein equations in the case where the first order vector and tensor
modes are negligible. These equations imply that the tensor and the vector mode
of the second order metric perturbations may be generated by the scalar-scalar
mode coupling of the linear order perturbations as the result of the non-linear
effects of the Einstein equations.Comment: 5 pages, no figure. RevTeX; short letter version of gr-qc/0605108;
some details of explanations are adde
Central and local government and the provision of municipal medicine, 1919-39
This article examines the relationship between central and local government - and specifically the County Boroughs - in interwar England and Wales with respect to the provision of municipal health services. It is argued that this relationship was complex, with different local authorities being compliant to a greater or lesser degree with the aspirations of the Ministry of Health. The latter, it is further suggested, started off its life as a relatively dynamic, well-run and farsighted part of central government, but for a range of reasons lost authority and influence as the interwar era progressed. This was not helped by the limited powers the Ministry held. The local authorities, meanwhile, differed widely in their aspirations for municipally-provided health care. Some were reluctant to do much, others had ambitions somewhat in advance of those of the Ministry of Health. What did unite local authorities was their collective desire to preserve the longstanding tradition of a high degree of local independence. As is also shown, specifically local factors and personnel - for example the political dynamics of the council or the standing of the Medical Officer of Health - could significantly shape a County Borough's approach to health care. The article thus contributes to the history of English and Welsh local government and, especially, to the relatively neglected period in the history of the health services which falls between the demise of the Poor Law and the coming of the National Health Service
IMPMOT user's manual
This user's manual describes the input and output variables as well as the job control language necessary to utilize the IMP-H apogee motor firing program, IMPMOT. The IMPMOT program can be executed as either a stand-alone program or as a member of the flight dynamics system. This program is used to determine the time and attitude at which to fire the IMP-H apogee boost motor. The IMPMOT program is written in FORTRAN 4 for use on the IBM 360 series computer
Catalytic surface effects on space thermal protection system during Earth entry of flights STS-2 through STS-5
An on going orbiter experiment catalytic surface effects experiment being conducted on the Space Shuttle is discussed. The catalytic surface effects experiment was peformed on four of the five flights of Columbia. Temperature time histories and distributions along the midfuselage and wing of the orbiter were used to determine the surface catalytic efficiency of the baseline high temperature reusable surface insulation. Correlation parameters are shown that allow the comparison of all flight data with predictions from the design and surface emittance decreased as a result of contaminants during the five flights of the Space Shuttle
An index to characterize the spatial distribution of land use within watersheds and implications for river network nutrient removal and export
The spatial distribution of land use and associated nutrient inputs may influence the efficacy of in-stream nutrient removal; however, the effect of source location on N removal and watershed N export has not been quantified. We present the skewness index, a metric to quantify the spatial distribution of land use within watersheds. Using this index and a river network nitrogen removal model, we quantified the effect of varying the location of developed land use within two watersheds on nutrient removal and export. The quantity and location of developed land use as well as runoff affected nitrogen removal and export. Because river network nitrogen removal is bypassed when sources are skewed toward the watershed mouth, varying the location of land use alone can double aquatic nitrogen removal. Nutrient sources skewed toward the distant headwaters maximized in-stream removal which in turn can reduce watershed export
Helical Symmetry in Linear Systems
We investigate properties of solutions of the scalar wave equation and
Maxwell's equations on Minkowski space with helical symmetry. Existence of
local and global solutions with this symmetry is demonstrated with and without
sources. The asymptotic properties of the solutions are analyzed. We show that
the Newman--Penrose retarded and advanced scalars exhibit specific symmetries
and generalized peeling properties.Comment: 11 page
Layering Transitions and Solvation Forces in an Asymmetrically Confined Fluid
We consider a simple fluid confined between two parallel walls (substrates),
separated by a distance L. The walls exert competing surface fields so that one
wall is attractive and may be completely wet by liquid (it is solvophilic)
while the other is solvophobic. Such asymmetric confinement is sometimes termed
a `Janus Interface'. The second wall is: (i) purely repulsive and therefore
completely dry (contact angle 180 degrees) or (ii) weakly attractive and
partially dry (the contact angle is typically in the range 160-170 degrees). At
low temperatures, but above the bulk triple point, we find using classical
density functional theory (DFT) that the fluid is highly structured in the
liquid part of the density profile. In case (i) a sequence of layering
transitions occurs: as L is increased at fixed chemical potential (mu) close to
bulk gas--liquid coexistence, new layers of liquid-like density develop
discontinuously. In contrast to confinement between identical walls, the
solvation force is repulsive for all wall separations and jumps discontinuously
at each layering transition and the excess grand potential exhibits many
metastable minima as a function of the adsorption. For a fixed temperature
T=0.56Tc, where Tc is the bulk critical temperature, we determine the
transition lines in the L, mu plane. In case (ii) we do not find layering
transitions and the solvation force oscillates about zero. We discuss how our
mean-field DFT results might be altered by including effects of fluctuations
and comment on how the phenomenology we have revealed might be relevant for
experimental and simulation studies of water confined between hydrophilic and
hydrophobic substrates, emphasizing it is important to distinguish between
cases (i) and (ii).Comment: 16 pages, 13 figure
Supercharged topping rocket propellant feed system
A rocket propellant feed system utilizing a bleed turbopump to supercharge a topping turbopump is presented. The bleed turbopump is of a low pressure type to meet the cavitation requirements imposed by the propellant storage tanks. The topping turbopump is of a high pressure type and develops 60 to 70 percent of the pressure rise in the propellant
Earth Observations Division version of the Laboratory for Applications of Remote Sensing System (EOD-LARSYS) user guide for the IBM 370/148. Volume 2: User reference manual
This document presents instructions for analysts who use the EOD-LARSYS as programmed on the Purdue University IBM 370/148 (recently replaced by the IBM 3031) computer. It presents sample applications, control cards, and error messages for all processors in the system and gives detailed descriptions of the mathematical procedures and information needed to execute the system and obtain the desired output. EOD-LARSYS is the JSC version of an integrated batch system for analysis of multispectral scanner imagery data. The data included is designed for use with the as built documentation (volume 3) and the program listings (volume 4). The system is operational from remote terminals at Johnson Space Center under the virtual machine/conversational monitor system environment
Fabrication and Electrical Characterization of Fully CMOS Si Single Electron Devices
We present electrical data of silicon single electron devices fabricated with
CMOS techniques and protocols. The easily tuned devices show clean Coulomb
diamonds at T = 30 mK and charge offset drift of 0.01 e over eight days. In
addition, the devices exhibit robust transistor characteristics including
uniformity within about 0.5 V in the threshold voltage, gate resistances
greater than 10 G{\Omega}, and immunity to dielectric breakdown in electric
fields as high as 4 MV/cm. These results highlight the benefits in device
performance of a fully CMOS process for single electron device fabrication.Comment: 7 pages, 7 figure
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