54 research outputs found
Asymptotically self-similar propagation of the spherical ionization waves
It is shown that a new type of the self-similar spherical ionization waves
may exist in gases. All spatial scales and the propagation velocity of such
waves increase exponentially in time. Conditions for existence of these waves
are established, their structure is described and approximate analytical
relationships between the principal parameters are obtained. It is notable that
spherical ionization waves can serve as the simplest, but structurally complete
and physically transparent model of streamer in homogeneous electric field.Comment: Corrected typos, the more precise formulas are obtaine
Electric discharge contour dynamics model: the effects of curvature and finite conductivity
In this paper we present the complete derivation of the effective contour
model for electrical discharges which appears as the asymptotic limit of the
minimal streamer model for the propagation of electric discharges, when the
electron diffusion is small. It consists of two integro-differential equations
defined at the boundary of the plasma region: one for the motion and a second
equation for the net charge density at the interface. We have computed explicit
solutions with cylindrical symmetry and found the dispersion relation for small
symmetry-breaking perturbations in the case of finite resistivity. We implement
a numerical procedure to solve our model in general situations. As a result we
compute the dispersion relation for the cylindrical case and compare it with
the analytical predictions. Comparisons with experimental data for a 2-D
positive streamers discharge are provided and predictions confirmed.Comment: 23 pages, 3 figure
Modulation of the nucleation rate pre-exponential in a low-temperature Ising system
A metastable lattice gas with nearest-neighbor interactions and
continuous-time dynamics is studied using a generalized Becker-Doring approach
in the multidimensional space of cluster configurations. The pre-exponential of
the metastable state lifetime (inverse of nucleation rate) is found to exhibit
distinct peaks at integer values of the inverse supersaturation. Peaks are
unobservable (infinitely narrow) in the strict limit T->0, but become
detectable and eventually dominate at higher temperatures.Comment: 4 pages, 2 Postscript figures, LaTeX, submitted to Phys. Rev. Lett.
Changes: updated references, re-written section around eqs.(5),(6), typos,
minor wording changes in conclusion and other parts of text (mostly in
response to referees' comments). Paper resubmitted to PR
Functional Relationship between Protein Disulfide Isomerase Family Members during the Oxidative Folding of Human Secretory Proteins
We systematically depleted PDI family members and show that whereas ERp72 and P5 contributed minimally to oxidative protein folding, PDI and ERp57 were the predominant catalysts. Depletion of PDI or ERp57 alone modestly delayed folding, but depletion of both led to generalized protein misfolding and degradation
ANALYSIS OF REGIONAL DIFFERENCES IN MATERIAL WELFARE OF THE POPULATION: THE GEORGIAN SSR
The History of Sociological Research on Occupations and Professions in the USSR 1960-80s: Ideological Frameworks and Analytical Resources
- ā¦