361 research outputs found
SANITARY PROTECTION OF TERRITORIES FROM SEVERE ACUTE RESPIRATORY SYNDROME (SARS) IMPORTATION AND DISSEMINATION BY WATER AND AIR TRANSPORT AT FAR EASTERN REGION
The existing programs and plans of sanitary protection of territories and municipalities of Russian Federation are directed to prevention of importation and dissemination of quarantine and other known infectious diseases. Modern organizing-methodical papers of Ministry of Public Health of Russian Federation include both nosological and syndromic approaches to resolution of this problem. SARS epidemic situation in the world with an active focus at Asian-Pacific Ocean Region has tested the Russian sanitary protection system at Far Eastern Region. Data on organization and realization of the measures at the period of SARS epidemic troubles in the world are analyzed. The experience of State Surveillance Centers at water and air transport in Far Eastern Region in co-operation with all transport process participants to prevent importation and dissemination of early unknown especially dangerous infection (SARS) is summarized
Josephson effects in dilute Bose-Einstein condensates
We propose an experiment that would demonstrate the ``dc'' and ``ac''
Josephson effects in two weakly linked Bose-Einstein condensates. We consider a
time-dependent barrier, moving adiabatically across the trapping potential. The
phase dynamics are governed by a ``driven-pendulum'' equation, as in
current-driven superconducting Josephson junctions. At a critical velocity of
the barrier (proportional to the critical tunneling current), there is a sharp
transition between the ``dc'' and ``ac'' regimes. The signature is a sudden
jump of a large fraction of the relative condensate population. Analytical
predictions are compared with a full numerical solution of the time dependent
Gross-Pitaevskii equation, in an experimentally realistic situation.Comment: 4 pages, 1 figur
Performance projections for the lithium tokamak experiment (LTX)
Use of a large-area liquid lithium limiter in the CDX-U tokamak produced the largest relative increase (an enhancement factor of 5-10) in Ohmic tokamak confinement ever observed. The confinement results from CDX-U do not agree with existing scaling laws, and cannot easily be projected to the new lithium tokamak experiment (LTX). Numerical simulations of CDX-U low recycling discharges have now been performed with the ASTRA-ESC code with a special reference transport model suitable for a diffusion-based confinement regime, incorporating boundary conditions for nonrecycling walls, with fuelling via edge gas puffing. This model has been successful at reproducing the experimental values of the energy confinement (4-6 ms), loop voltage (<0.5 V), and density for a typical CDX-U lithium discharge. The same transport model has also been used to project the performance of the LTX, in Ohmic operation, or with modest neutral beam injection (NBI). NBI in LTX, with a low recycling wall of liquid lithium, is predicted to result in core electron and ion temperatures of 1-2 keV, and energy confinement times in excess of 50 ms. Finally, the unique design features of LTX are summarized
Anomalous Heat Conduction and Anomalous Diffusion in Low Dimensional Nanoscale Systems
Thermal transport is an important energy transfer process in nature. Phonon
is the major energy carrier for heat in semiconductor and dielectric materials.
In analogy to Ohm's law for electrical conductivity, Fourier's law is a
fundamental rule of heat transfer in solids. It states that the thermal
conductivity is independent of sample scale and geometry. Although Fourier's
law has received great success in describing macroscopic thermal transport in
the past two hundreds years, its validity in low dimensional systems is still
an open question. Here we give a brief review of the recent developments in
experimental, theoretical and numerical studies of heat transport in low
dimensional systems, include lattice models, nanowires, nanotubes and
graphenes. We will demonstrate that the phonon transports in low dimensional
systems super-diffusively, which leads to a size dependent thermal
conductivity. In other words, Fourier's law is breakdown in low dimensional
structures
Equilibrium reconstruction for Single Helical Axis reversed field pinch plasmas
Single Helical Axis (SHAx) configurations are emerging as the natural state
for high current reversed field pinch (RFP) plasmas. These states feature the
presence of transport barriers in the core plasma. Here we present a method for
computing the equilibrium magnetic surfaces for these states in the force-free
approximation, which has been implemented in the SHEq code. The method is based
on the superposition of a zeroth order axisymmetric equilibrium and of a first
order helical perturbation computed according to Newcomb's equation
supplemented with edge magnetic field measurements. The mapping of the measured
electron temperature profiles, soft X-ray emission and interferometric density
measurements on the computed magnetic surfaces demonstrates the quality of the
equilibrium reconstruction. The procedure for computing flux surface averages
is illustrated, and applied to the evaluation of the thermal conductivity
profile. The consistency of the evaluated equilibria with Ohm's law is also
discussed.Comment: Submitted to Plasma Physics and Controlled Fusio
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