7,687 research outputs found
The Problem of Scheduling for the Linear Section of a Single-Track Railway with Independent Edges Orientations
The paper is devoted to the problem of scheduling for the linear section of a single-track railway: how to organize the ow in both directions in the most efficient way. In this paper, the authors propose an algorithm for scheduling with independent edges orientations, examine the properties of this algorithm and perform the computational experiments
Nonequilibrium phenomena in multiple normal-superconducting tunnel heterostructures
Using the nonequilibrium theory of superconductivity with the tunnel
Hamiltonian, we consider a mesoscopic NISINISIN heterostructure, i.e., a
structure consisting of five intermittent normal-metal (N) and superconducting
(S) regions separated by insulating tunnel barriers (I). Applying the bias
voltage between the outer normal electrodes one can drive the central N island
very far from equilibrium. Depending on the resistance ratio of outer and inner
tunnel junctions, one can realize either effective electron cooling in the
central N island or create highly nonequilibrium energy distributions of
electrons in both S and N islands. These distributions exhibit multiple peaks
at a distance of integer multiples of the superconducting chemical potential.
In the latter case the superconducting gap in the S islands is strongly
suppressed as compared to its equilibrium value
Snow metamorphism: a fractal approach
Snow is a porous disordered medium consisting of air and three water phases:
ice, vapour and liquid. The ice phase consists of an assemblage of grains, ice
matrix, initially arranged over a random load bearing skeleton. The
quantitative relationship between density and morphological characteristics of
different snow microstructures is still an open issue. In this work, a
three-dimensional fractal description of density corresponding to different
snow microstructure is put forward. First, snow density is simulated in terms
of a generalized Menger sponge model. Then, a fully three-dimensional compact
stochastic fractal model is adopted. The latter approach yields a quantitative
map of the randomness of the snow texture, which is described as a
three-dimensional fractional Brownian field with the Hurst exponent H varying
as continuous parameter. The Hurst exponent is found to be strongly dependent
on snow morphology and density. The approach might be applied to all those
cases where the morphological evolution of snow cover or ice sheets should be
conveniently described at a quantitative level
Search for new pharmacological targets for increasing the efficiency of correction of cardiovascular diseases
It is noted that currently, there are no drugs for specific pharmacological correction of endothelial dysfunction in cardiovascular diseases, and the search for new targets for pharmacological correction of endothelial dysfunction is one of the main tasks of pharmacolog
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