2,679 research outputs found
The Environment for Application Software Integration and Execution (EASIE) version 1.0. Volume 4: System installation and maintenance guide
The Environment for Application Software Integration and Execution (EASIE) provides both a methodology and a set of software utility programs to ease the task of coordinating engineering design and analysis codes. This document provides necessary information for installing the EASIE software on a host computer system. The target host is a DEX VAX running VMS version 4; host dependencies are noted when appropriate. Relevant directories and individual files are identified, and compile/load/execute sequences are specified. In the case of the data management utilities, database management system (DBMS) specific features are described in an effort to assist the maintenance programmer in converting to a new DBMS. The document also describes a sample EASIE program directory structure to guide the program implementer in establishing his/her application dependent environment
The Environment for Application Software Integration and Execution (EASIE), version 1.0. Volume 2: Program integration guide
The Environment for Application Software Integration and Execution, EASIE, provides a methodology and a set of software utility programs to ease the task of coordinating engineering design and analysis codes. EASIE was designed to meet the needs of conceptual design engineers that face the task of integrating many stand-alone engineering analysis programs. Using EASIE, programs are integrated through a relational data base management system. In volume 2, the use of a SYSTEM LIBRARY PROCESSOR is used to construct a DATA DICTIONARY describing all relations defined in the data base, and a TEMPLATE LIBRARY. A TEMPLATE is a description of all subsets of relations (including conditional selection criteria and sorting specifications) to be accessed as input or output for a given application. Together, these form the SYSTEM LIBRARY which is used to automatically produce the data base schema, FORTRAN subroutines to retrieve/store data from/to the data base, and instructions to a generic REVIEWER program providing review/modification of data for a given template. Automation of these functions eliminates much of the tedious, error prone work required by the usual approach to data base integration
Particle Acceleration in Supernova Remnants and the Production of Thermal and Nonthermal Radiation
If highly efficient, cosmic ray production can have a significant effect on
the X-ray emission from SNRs as well as their dynamical evolution. Using
hydrodynamical simulations including diffusive shock acceleration, we produce
spectra for both the thermal and nonthermal forward shock emission. For a given
ambient density and explosion energy, we find that the position of the forward
shock at a given age is a strong function of the acceleration efficiency,
providing a signature of cosmic-ray production. Using an approximate treatment
for the ionization state of the plasma, we investigate the effects of slow vs.
rapid heating of the postshock electrons on the ratio of thermal to nonthermal
X-ray emission at the forward shock. We also investigate the effects of
magnetic field strength on the observed spectrum for efficient cosmic-ray
acceleration. The primary effect of a large field is a considerable flattening
of the nonthermal spectrum in the soft X-ray band. Spectral index measurements
from X-ray observations may thus be indicators of the postshock magnetic field
strength. The predicted gamma-ray flux from inverse-Compton (IC) scattering and
neutral pion decay is strongly affected by the ambient conditions and, for the
particular parameters used in our examples, the IC emission at E ~ 1 TeV
exceeds that from pion decay, although at both lower and higher energies this
trend is reversed for cases of high ambient density. More importantly, high
magnetic fields produce a steepening of the electron spectrum over a wide
energy range which may make it more difficult to differentiate between IC and
pion-decay emission solely by spectral shape.Comment: 30 pages, 12 figures, submitted to ApJ January 200
Arctic sea-ice melt in 2008 and the role of solar heating
There has been a marked decline in the summer extent of Arctic sea ice over the past few decades. Data from autonomous ice mass-balance buoys can enhance our understanding of this decline. These buoys monitor changes in snow deposition and ablation, ice growth, and ice surface and bottom melt. Results from the summer of 2008 showed considerable large-scale spatial variability in the amount of surface and bottom melt. Small amounts of melting were observed north of Greenland, while melting in the southern Beaufort Sea was quite large. Comparison of net solar heat input to the ice and heat required for surface ablation showed only modest correlation. However, there was a strong correlation between solar heat input to the ocean and bottom melting. As the ice concentration in the Beaufort Sea region decreased, there was an increase in solar heat to the ocean and an increase in bottom melting
A model for the distribution of aftershock waiting times
In this work the distribution of inter-occurrence times between earthquakes
in aftershock sequences is analyzed and a model based on a non-homogeneous
Poisson (NHP) process is proposed to quantify the observed scaling. In this
model the generalized Omori's law for the decay of aftershocks is used as a
time-dependent rate in the NHP process. The analytically derived distribution
of inter-occurrence times is applied to several major aftershock sequences in
California to confirm the validity of the proposed hypothesis.Comment: 4 pages, 3 figure
Nonlinear Diffusive Shock Acceleration with Magnetic Field Amplification
We introduce a Monte Carlo model of nonlinear diffusive shock acceleration
allowing for the generation of large-amplitude magnetic turbulence. The model
is the first to include strong wave generation, efficient particle acceleration
to relativistic energies in nonrelativistic shocks, and thermal particle
injection in an internally self-consistent manner. We find that the upstream
magnetic field can be amplified by large factors and show that this
amplification depends strongly on the ambient Alfven Mach number. We also show
that in the nonlinear model large increases in the magnetic field do not
necessarily translate into a large increase in the maximum particle momentum a
particular shock can produce, a consequence of high momentum particles
diffusing in the shock precursor where the large amplified field converges to
the low ambient value. To deal with the field growth rate in the regime of
strong fluctuations, we extend to strong turbulence a parameterization that is
consistent with the resonant quasi-linear growth rate in the weak turbulence
limit. We believe our parameterization spans the maximum and minimum range of
the fluctuation growth and, within these limits, we show that the nonlinear
shock structure, acceleration efficiency, and thermal particle injection rates
depend strongly on the yet to be determined details of wave growth in strongly
turbulent fields. The most direct application of our results will be to
estimate magnetic fields amplified by strong cosmic-ray modified shocks in
supernova remnants.Comment: Accepted in ApJ July 2006, typos corrected in this versio
Favorable cardiovascular health at young and middle ages and dementia in older age—The CHA study
Chronic Invasive Aspergillosis caused by Aspergillus viridinutans
Aspergillus viridinutans, a mold phenotypically resembling A. fumigatus, was identified by gene sequence analyses from 2 patients. Disease was distinct from typical aspergillosis, being chronic and spreading in a contiguous manner across anatomical planes. We emphasize the recognition of fumigati-mimetic molds as agents of chronic or refractory aspergillosis
Further Studies on Vibration Compaction of Cohesive Soils
The investigations described in this report are a continuation of previous work
designed to determine the basic laws governing the compaction of cohesive soil by vibration.
A report dated December, 1954, described the results of tests on sandy loam, while
this report describes similar tests on a much more cohesive soil
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