6,457 research outputs found
Advanced recovery systems wind tunnel test report
Pioneer Aerospace Corporation (PAC) conducted parafoil wind tunnel testing in the NASA-Ames 80 by 120 test sections of the National Full-Scale Aerodynamic Complex, Moffett Field, CA. The investigation was conducted to determine the aerodynamic characteristics of two scale ram air wings in support of air drop testing and full scale development of Advanced Recovery Systems for the Next Generation Space Transportation System. Two models were tested during this investigation. Both the primary test article, a 1/9 geometric scale model with wing area of 1200 square feet and secondary test article, a 1/36 geometric scale model with wing area of 300 square feet, had an aspect ratio of 3. The test results show that both models were statically stable about a model reference point at angles of attack from 2 to 10 degrees. The maximum lift-drag ratio varied between 2.9 and 2.4 for increasing wing loading
Universal decay law in charged-particle emission and exotic cluster radioactivity
A linear universal decay formula is presented starting from the microscopic
mechanism of the charged-particle emission. It relates the half-lives of
monopole radioactive decays with the -values of the outgoing particles as
well as the masses and charges of the nuclei involved in the decay. This
relation is found to be a generalization of the Geiger-Nuttall law in
radioactivity and explains well all known cluster decays. Predictions on the
most likely emissions of various clusters are presented.Comment: 2 figure
Dimensionality effects in dipolar fluids
Using classical density functional theory (DFT) in a modified mean-field
approximation we investigate the fluid phase behavior of quasi-two dimensional
dipolar fluids confined to a plane. The particles carry three-dimensional
dipole moments and interact via a combination of hard-sphere, van-der-Waals,
and dipolar interactions. The DFT predicts complex phase behavior involving
first- and second-order isotropic-to-ferroelectric transitions, where the
ferroelectric ordering is characterized by global polarization within the
plane. We compare this phase behavior, particularly the onset of ferroelectric
ordering and the related tricritical points, with corresponding
three-dimensional systems, slab-like systems (with finite extension into the
third direction), and true two-dimensional systems with two-dimensional dipole
moments.Comment: 7 pages, 2 figure
A fast edge charge exchange recombination spectroscopy system at the ASDEX Upgrade tokamak
In this work, a new type of high through-put Czerny-Turner spectrometer has been developed which
allows us to acquire multiple channels simultaneously with a repetition time on the order of 10
μ
s
at different wavelengths. The spectrometer has been coupled to the edge charge exchange recom-
bination system at ASDEX Upgrade which has been recently refurbished with new lines of sight.
Construction features, calibration methods, and initial measurements obtained with the new setup will
be presented.European Commission (EUROfusion 633053
Examining the Personal and Institutional Determinants of Research Productivity in Hospitality and Tourism Management
The transition toward a post-capitalist knowledge-oriented economy has resulted in an increasingly competitive academic environment, where the success of faculty is dependent on their research productivity. This study examines the personal and institutional determinants of the quantity and quality of the research productivity of hospitality and tourism management faculty in US institutions. A survey of 98 faculty found that a different set of determinants impact the quantity and quality aspects of research productivity. Also, institutional determinants were found to play a larger role, indicating the need for administrators to strive for a culture that is supportive of and an infrastructure that is conducive to their faculty’s research success. The authors use the field of hospitality and tourism management as a case study to develop a holistic and cohesive framework for knowledge worker productivity that can guide the evaluation, hiring, and development of researchers
Biochemistry and functional aspects of human glandular kallikreins
Human urinary kallikrein was purified by gel filtration on Sephacryl S-200 and affinity chromatography on aprotinin-Sepharose, followed by ion exchange chromatography on DEAE-Sepharose. In dodecylsulfate gel electrophoresis two protein bands with molecular weights of 41,000 and 34,000 were separated. The amino acid composition and the carbohydrate content of the kallikrein preparation were determined; isoleucine was identified as the only aminoterminal amino acid. The bimolecular velocity constant for the inhibition by diisopropyl fluorophosphate was determined as 9±2 l mol–1 min–1. The hydrolysis of a number of substrates was investigated and AcPheArgOEt was found to be the most sensitive substrate for human urinary kallikrein. Using this substrate an assay method for kallikrein in human urine was developed.
It was shown by radioimmunoassay that pig pancreatic kallikrein can be absorbed in the rat intestinal tract. Furthermore, in dogs the renal excretion of glandular kallikrein from blood was demonstrated by radioimmunological methods
Analysis of reaction dynamics at RHIC in a combined parton/hadron transport approach
We introduce a transport approach which combines partonic and hadronic
degrees of freedom on an equal footing and discuss the resulting reaction
dynamics. The initial parton dynamics is modeled in the framework of the parton
cascade model, hadronization is performed via a cluster hadronization model and
configuration space coalescence, and the hadronic phase is described by a
microscopic hadronic transport approach. The resulting reaction dynamics
indicates a strong influence of hadronic rescattering on the space-time pattern
of hadronic freeze-out and on the shape of transverse mass spectra. Freeze-out
times and transverse radii increase by factors of 2 - 3 depending on the hadron
species.Comment: 10 pages, 4 eps figures include
Thermal and Chemical Equilibration in Relativistic Heavy Ion Collisions
We investigate the thermalization and the chemical equilibration of a parton
plasma created from Au+Au collision at LHC and RHIC energies starting from the
early moment when the particle momentum distributions in the central region
become for the first time isotropic due to longitudinal cooling. Using the
relaxation time approximation for the collision terms in the Boltzmann
equations for gluons and for quarks and the real collision terms constructed
from the simplest QCD interactions, we show that the collision times have the
right behaviour for equilibration. The magnitude of the quark (antiquark)
collision time remains bigger than the gluon collision time throughout the
lifetime of the plasma so that gluons are equilibrating faster than quarks both
chemically and kinetically. That is we have a two-stage equilibration scenario
as has been pointed out already by Shuryak sometimes ago. Full kinetic
equilibration is however slow and chemical equilibration cannot be completed
before the onset of the deconfinement phase transition assumed to be at
MeV. By comparing the collision entropy density rates of the
different processes, we show explicitly that inelastic processes, and
\emph{not} elastic processes as is commonly assumed, are dominant in the
equilibration of the plasma and that gluon branching leads the other processes
in entropy generation. We also show that, within perturbative QCD, processes
with higher power in \alpha_s need not be less important for the purpose of
equilibration than those with lower power. The state of equilibration of the
system has also a role to play. We compare our results with those of the parton
cascade model.Comment: 17 pages, revtex+psfig style with 14 embedded postscript figures, to
appear in Phys. Rev.
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