610 research outputs found
Novel kinetic consistent mhd algorithm for high performance computing
The impressive progress of the kinetic schemes in the solution of gas dy-
namics problems and the development of effective parallel algorithms for modern high
performance parallel computing systems led to the development of advanced methods for the
solution of the magnetohydrodynamics problem in the important area of plasma physics. The novel
feature of the method is the formulation of the complex Boltzmann- like distribution function of
kinetic method with the implementation of electromagnetic interaction terms. The numerical method
is based on the explicit schemes. Due to logical simplicity and its efficiency, the algorithm is
easily adapted to modern high performance parallel computer systems including hybrid computing
systems with graphic processors
Lotka--Volterra Type Equations and their Explicit Integration
In the present note we give an explicit integration of some
two--dimensionalised Lotka--Volterra type equations associated with simple Lie
algebras, other than the familiar case, possessing a representation
without branching. This allows us, in particular, to treat the first
fundamental representations of , , , and on the same
footing.Comment: 3 pages LATEX fil
Statistical distribution function of charged particles in magnetic field
The statistical distribution function introduced by Boltzmann and his ki-
netic equation are the fundamental basis of the kinetic theory of gases and of the basic
methods of solution of problems in the gas dynamics. At present time one of the areas of high
interest in modern physics is the plasma in fusion processes and astrophysics which requires an
extension of the kinetic processes to charged particles, in particular regard- ing the
electromagnetic interactions. We propose a unified distribution function which includes the
electromagnetic interactions for charged particles and is suitable for the solu- tion of problems
of charged particle dynamics with Boltzmann type equations and kinetic
consistent magneto gas dynamic equations
Novel kinetic consistent algorithm for the modeling of incompressible conducting flows
In this study we aim at demonstrating that kinetic consistent magneto gas
dynamic algorithms are a valid for the computation of the dynamics of incompressible
conductive flows. We obtain numerical solutions for the test problems, namely the laminar flow
inside a wall-driven cavity and a magnetic driven pump. We show that kinetic
consistent algorithms have a high stability in the solution of convection-dominated flows, due to a
correct physical modeling of the fluid viscosity and to the possibility of tuning appropriate
regularization terms on the basis of the physical properties of the fluid. We show that the
kinetic consistent approach offers a stable basis for a correct physical description of
the shear viscosity, thermal conduction and electric resistivity effects in
incompressible magneto hydrodynamics flows
Novel kinetic consistent 3d mhd algorithm for high performance parallel computing systems
The impressive progress of the kinetic consistent schemes in the solution of the gas
dynamics problems and the development of the effective parallel algorithms for the modern
high performance parallel computing systems lead to the development of advanced methods
for the solution of the magnetohydrodynamics problems for plasma physics. The novel
feature of the method is the formulation of the complex Boltzmann-like distribution function
of the kinetic method with the implementation of the electromagnetic interaction term. The
numerical method is based on the explicit schemes, due to the logical simplicity and high
efficiency of the algorithm and the easy adaptation to the modern high performance parallel
computing systems
The Digital Silicon Photomultiplier
The Silicon Photomultipliers (SiPMs) are the new step in the development of the modern detection structures in the area of low photon flux detection with a unique capability of detection up to the single photons. The Silicon Photomultiplier intrinsically represents a digital signal source on the elementary cell level. The materials and technology of SiPMs are consistent with the modern electronics technology. We present the realization and implementation of a fully digital Silicon Photomultiplier Imager with an enclosed readout and processing on the basis of modern 3D technology
A novel method for magnetohydrodynamic simulations and its first applications in astrophysics and cosmology on high performance computational systems
Magnetic ïŹelds are one of the most important phenomena in science and engineering, as they are present on almost every scale in nature, ranging from atomic magnetic moments to the intergalactic space, and are used in applications ranging from Magnetic Resonance Imaging to nuclear fusion. In this work we ïŹrst present a novel powerful method for high performance magnetohydrodynamic (MHD) calculations which is based on kinetic schemes. In particular, using it, it is possible to derive the MHD equations directly from the Boltzmann Equation without the necessity of an ad hoc introduction of terms related to electromagnetic interactions. With that at hand, we were then able to apply the method to one of the most important problems in present day astrophysics and cosmology, namely to the question of the origin and time evolution of Intergalactic Magnetic Fields. As for their origin, there are mainly two scenarios discussed in the literature â on the one hand the cosmological one, where the magnetic ïŹeld is produced by some process in the very early Universe, and on the other hand the cosmological one, where a seed of the magnetic ïŹeld is created during structure formation and then ampliïŹed by some dynamo eïŹect. Here, we show ïŹrst results of the aforementioned application of our method â on the one hand, concerning the astrophysical scenario, the simulation of galactic winds, i.e. the ejection of matter from galaxies which might also carry magnetic energy, and on the other hand, for the cosmological scenario, the time evolution of primordial magnetic ïŹelds and their possible imprints on the Cosmic Microwave Background (CMB)
Use of Vanadium for Low-alloy Steel Manufacturing at JSC âEVRAZ NTMKâ
Joint Stock Company âEVRAZ Nizhniy Tagil Metallurgical Plantâ ( JSC âEVRAZ NTMKâ) is the Worldâs largest processor of vanadium-rich titanium magnetite ores. This work describes the results of the research performed to test various combinations of vanadium and nitrogen microalloying targeted at repeatable quality and strength properties of the rolled steel products. In particular the benefits are described of using vanadium mass fractions in steel for manufacturing railway steel (rails, wheels, rings/tires), railcar body products (Z-beams, I-beams, etc.), API grades including large diameter X70 and X80 pipes. To optimize the analysis of different steel grades for the shaped sections manufacturing EVRAZ NTMK has taken efforts to identify the impact of the vanadium mass fraction in steel grade 09G2S on the mechanical properties of rolled steel with the elements of various thickness. During the effort, the mechanical tests were performed, the extent of vanadium reduction in the form of carbonitrides during the rolling and cooling process and its impact on the mechanical properties, the macrostructuring of rolled products was also studied. Recommendations were given on the chemical composition of steel 09G2S for manufacturing rolled steel of strength classes 375 and 390.
Keywords: EVRAZ NTMK, vanadium, I-beams, mechanical properties, impact strengt
Topological gravity on plumbed V-cobordisms
An ensemble of cosmological models based on generalized BF-theory is
constructed where the role of vacuum (zero-level) coupling constants is played
by topologically invariant rational intersection forms (cosmological-constant
matrices) of 4-dimensional plumbed V-cobordisms which are interpreted as
Euclidean spacetime regions. For these regions describing topology changes, the
rational and integer intersection matrices are calculated. A relation is found
between the hierarchy of certain elements of these matrices and the hierarchy
of coupling constants of the universal (low-energy) interactions.
PACS numbers: 0420G, 0240, 0460Comment: 29 page
--geometry of the Toda systems associated with non-exceptional simple Lie algebras
The present paper describes the --geometry of the Abelian finite
non-periodic (conformal) Toda systems associated with the and series
of the simple Lie algebras endowed with the canonical gradation. The principal
tool here is a generalization of the classical Pl\"ucker embedding of the
-case to the flag manifolds associated with the fundamental representations
of , and , and a direct proof that the corresponding K\"ahler
potentials satisfy the system of two--dimensional finite non-periodic
(conformal) Toda equations. It is shown that the --geometry of the type
mentioned above coincide with the differential geometry of special holomorphic
(W) surfaces in target spaces which are submanifolds (quadrics) of with
appropriate choices of . In addition, these W-surfaces are defined to
satisfy quadratic holomorphic differential conditions that ensure consistency
of the generalized Pl\"ucker embedding. These conditions are automatically
fulfiled when Toda equations hold.Comment: 30 pages, no figur
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