148,836 research outputs found
Skylab astronaut life support assembly
A comparative study was performed to define an optimum portable life support system for suited operations inside and outside the Skylab Program. Emphasis was placed on utilization of qualified equipment, modified versions of qualified equipment, and new systems made up to state-of-the-art components. Outlined are the mission constraints, operational modes, and evaluation ground rules by which the Skylab portable life support system was selected and the resulting design
Localization to delocalization transition in a driven nonlinear cavity array
We study nonlinear cavity arrays where the particle relaxation rate in each
cavity increases with the excitation number. We show that coherent parametric
inputs can drive such arrays into states with commensurate filling that form
non-equilibrium analogs of Mott insulating states. We explore the boundaries of
the Mott insulating phase and the transition to a delocalized phase with
spontaneous first order coherence. While sharing many similarities with the
Mott insulator to superfluid transition in equilibrium, the phase-diagrams we
find also show marked differences. Particularly the off diagonal order does not
become long range since the influence of dephasing processes increases with
increasing tunneling rates.Comment: 7 pages, 8 figure
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FEMA’s Public Assistance Grant Program: Background and Considerations for Congress
[Excerpt] The Robert T. Stafford Disaster Relief and Emergency Assistance Act (42 U.S.C. 5121 et seq., henceforth the Stafford Act) confers upon the President a broad set of authorities “to alleviate the suffering and damage” of affected tribal, state, and local governments, as well as individual citizens, from disasters. The Federal Emergency Management Agency (FEMA) of the Department of Homeland Security (DHS) has been given the responsibility of administering almost all of the President’s Stafford Act authorities through other law, a series of Executive Orders, and a DHS delegation. FEMA has established the Public Assistance (PA) Grant Program by combining the authority of multiple sections of the Stafford Act. The PA Program provides financial grant assistance to states, tribes, and local communities both in the response to and recovery from significant disasters. Between FY2000-FY2013, the PA Program has provided $52.6 billion in grant assistance to help communities pay for an array of eligible response and recovery activities, including debris removal, emergency protective measures, and the repair, replacement, or restoration of disaster-damaged, publicly owned facilities and the facilities of certain private nonprofit (PNP) organizations. The authorities of the PA Program were most recently significantly amended by the Sandy Recovery Improvement Act (Division B of P.L. 113- 2, the Disaster Relief Appropriations Act, 2013; henceforth SRIA). For a brief legislative history of PA Program authorities, see Appendix A.
This report provides background on key elements of the PA Program, such as the eligibility of applicants, the types of assistance available, and the methods FEMA uses for awarding grant assistance. Summary analysis of federal obligations for PA Program assistance is also provided along important variables, such as the distribution of federal obligations across the PA Program eligible categories of work assistance. The report concludes with discussion of several policy issues that Congress may wish to consider when evaluating the PA Program in the future, including considerations of significant prospective changes to the PA Program and the role of the PA Program in the context of other federal agency disaster assistance authorities
Shell model description of the 14C dating beta decay with Brown-Rho-scaled NN interactions
We present shell model calculations for the beta-decay of the 14C ground
state to the 14N ground state, treating the states of the A=14 multiplet as two
0p holes in an 16O core. We employ low-momentum nucleon-nucleon (NN)
interactions derived from the realistic Bonn-B potential and find that the
Gamow-Teller matrix element is too large to describe the known lifetime. By
using a modified version of this potential that incorporates the effects of
Brown-Rho scaling medium modifications, we find that the GT matrix element
vanishes for a nuclear density around 85% that of nuclear matter. We find that
the splitting between the (J,T)=(1+,0) and (J,T)=(0+,1) states in 14N is
improved using the medium-modified Bonn-B potential and that the transition
strengths from excited states of 14C to the 14N ground state are compatible
with recent experiments.Comment: 4 pages, 5 figures Updated to include referee comments/suggestion
Polarisation dependence of magnetic Bragg scattering in YMnO
The polarisation dependence of the intensity of elastic magnetic scattering
from \ymno\ single crystals has been measured at 25 K in magnetic fields
between 1 and 9 T. A significant polarisation dependence was observed in the
intensities of magnetic satellite reflections, propagation vector
\pv=0.5,0,0.25 measured with both the [100] and [010] axes parallel to the
common polarisation and applied field direction. The intensity asymmetries
observed in sets of orthorhombicly equivalent reflections show systematic
relationships which allow the phase relationship between different components
of their magnetic interaction vectors to be determined. They fix the
orientation relationships between the small and moments on the \mnfp\
and \mntp\ sub-lattices and lend support to the structure reported by Kim et
al. It was found that that which suggests
that there is a small modulation of the nuclear structure which has the same
wave-vector as the magnetic modulation leading to a small nuclear structure
factor for the satellite reflections. The differences observed indicate shifts in the atomic positions of order 0.005 \AA
TMS communications hardware. Volume 2: Bus interface unit
A prototype coaxial cable bus communication system used in the Trend Monitoring System to interconnect intelligent graphics terminals to a host minicomputer is described. The terminals and host are connected to the bus through a microprocessor-based RF modem termed a Bus Interface Unit (BIU). The BIU hardware and the Carrier Sense Multiple Access Listen-While-Talk protocol used on the network are described
Estimation of a preference based single index from the sexual quality of life questionnaire (SQOL) using ordinal data
There is increasing interest in using ordinal methods to estimate cardinal values for health states to calculate quality adjusted life years. This paper reports the estimation of models of rank data and discrete choice experiment (DCE) data to derive a preference-based index from a condition specific measure relating to sexual health and to compare the results to values generated from time trade-off valuation (TTO). The DCE data were analysed using a random effects probit model and the DCE predicted values were rescaled according to the highest and lowest predicted TTO values corresponding to the best and worst SQOL health states respectively. The rank data were analysed using a rank ordered logit model and re-scaled using two alternative methods. Firstly, re-scaling the rank predicted values using identical methods to those employed for DCE and secondly, re-scaling the rank model coefficients by dividing each level coefficient by the coefficient relating to death. The study raises some important issues about the use of ordinal data to produce cardinal health state valuations
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