1,425 research outputs found
Understanding Divertor Detachment through CRETIN Modeling - a Work in Progress
From numerous studies aimed at reducing the divertor target plate incident heat flux or understanding divertor detachment, an abundance of evidence supporting the importance of atomic processes in tokamak plasmas now exists. Through use of a multi-dimensional Non-Local Thermodynamic Equilibrium (NLTE) simulation code named CRETIN [1] this repor
Preliminary Investigation of the Frictional Response of Reptilian Shed Skin
Developing deterministic surfaces relies on controlling the structure of the
rubbing interface so that not only the surface is of optimized topography, but
also is able to self-adjust its tribological behaviour according to the
evolution of sliding conditions. In seeking inspirations for such designs, many
engineers are turning toward the biological world to correlate surface
structure to functional behavior of bio-analogues. From a tribological point of
view, squamate reptiles offer diverse examples where surface texturing,
submicron and nano-scale features, achieve frictional regulation. In this
paper, we study the frictional response of shed skin obtained from a snake
(Python regius). The study employed a specially designed tribo-acoustic probe
capable of measuring the coefficient of friction and detecting the acoustical
behavior of the skin in vivo. The results confirm the anisotropy of the
frictional response of snakes. The coefficient of friction depends on the
direction of sliding: the value in forward motion is lower than that in the
backward direction. In addition it is shown that the anisotropy of the
frictional response may stem from profile asymmetry of the individual fibril
structures present within the ventral scales of the reptil
Cosmic ray tests of the D0 preshower detector
The D0 preshower detector consists of scintillator strips with embedded
wavelength-shifting fibers, and a readout using Visible Light Photon Counters.
The response to minimum ionizing particles has been tested with cosmic ray
muons. We report results on the gain calibration and light-yield distributions.
The spatial resolution is investigated taking into account the light sharing
between strips, the effects of multiple scattering and various systematic
uncertainties. The detection efficiency and noise contamination are also
investigated.Comment: 27 pages, 24 figures, submitted to NIM
Looking Beyond Inflationary Cosmology
In spite of the phenomenological successes of the inflationary universe
scenario, the current realizations of inflation making use of scalar fields
lead to serious conceptual problems which are reviewed in this lecture. String
theory may provide an avenue towards addressing these problems. One particular
approach to combining string theory and cosmology is String Gas Cosmology. The
basic principles of this approach are summarized.Comment: invited talk at "Theory Canada 1" (Univ. of British Columbia,
Vancouver, Canada, June 2 - 4, 2005) (references updated
Trade-offs in the performance of workflows - quantifying the impact of best practices
Business process redesign is one of the most powerful ways to boost business performance and to improve customer satisfaction [14]. A possible approach to business process redesign is using redesign best practices. A previous study identified a set of 29 different redesign best practices [18]. However, little is known about the exact impact of these redesign best practices on workflow performance. This study proposes an approach that can be used to quantify the impact of a business process redesign project on all dimensions of workflow performance. The approach consists of a large set of performance measures and a simulation toolkit. It supports the quantification of the impact of the implementation of redesign best practices, in order to determine what best practice or combination of best practices leads to the most favorable effect in a specific business process. The approach is developed based on a quantification project for the parallel best practice [8] and is validated with two other quantification projects, namely for the knockout and triage best practices
Lifetime distributions in the methods of non-equilibrium statistical operator and superstatistics
A family of non-equilibrium statistical operators is introduced which differ
by the system age distribution over which the quasi-equilibrium (relevant)
distribution is averaged. To describe the nonequilibrium states of a system we
introduce a new thermodynamic parameter - the lifetime of a system.
Superstatistics, introduced in works of Beck and Cohen [Physica A \textbf{322},
(2003), 267] as fluctuating quantities of intensive thermodynamical parameters,
are obtained from the statistical distribution of lifetime (random time to the
system degeneracy) considered as a thermodynamical parameter. It is suggested
to set the mixing distribution of the fluctuating parameter in the
superstatistics theory in the form of the piecewise continuous functions. The
distribution of lifetime in such systems has different form on the different
stages of evolution of the system. The account of the past stages of the
evolution of a system can have a substantial impact on the non-equilibrium
behaviour of the system in a present time moment.Comment: 18 page
Long time dynamics and coherent states in nonlinear wave equations
We discuss recent progress in finding all coherent states supported by
nonlinear wave equations, their stability and the long time behavior of nearby
solutions.Comment: bases on the authors presentation at 2015 AMMCS-CAIMS Congress, to
appear in Fields Institute Communications: Advances in Applied Mathematics,
Modeling, and Computational Science 201
Double Inflation in Supergravity and the Large Scale Structure
The cosmological implication of a double inflation model with hybrid + new
inflations in supergravity is studied. The hybrid inflation drives an inflaton
for new inflation close to the origin through supergravity effects and new
inflation naturally occurs. If the total e-fold number of new inflation is
smaller than , both inflations produce cosmologically relevant density
fluctuations. Both cluster abundances and galaxy distributions provide strong
constraints on the parameters in the double inflation model assuming
standard cold dark matter scenario. The future satellite
experiments to measure the angular power spectrum of the cosmic microwave
background will make a precise determination of the model parameters possible.Comment: 19 pages (RevTeX file
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