1,930 research outputs found
Markov evolutions and hierarchical equations in the continuum I. One-component systems
General birth-and-death as well as hopping stochastic dynamics of infinite
particle systems in the continuum are considered. We derive corresponding
evolution equations for correlation functions and generating functionals.
General considerations are illustrated in a number of concrete examples of
Markov evolutions appearing in applications.Comment: 47 page
Regulation mechanisms in spatial stochastic development models
The aim of this paper is to analyze different regulation mechanisms in
spatial continuous stochastic development models. We describe the density
behavior for models with global mortality and local establishment rates. We
prove that the local self-regulation via a competition mechanism (density
dependent mortality) may suppress a unbounded growth of the averaged density if
the competition kernel is superstable.Comment: 19 page
Vlasov scaling for stochastic dynamics of continuous systems
We describe a general scheme of derivation of the Vlasov-type equations for
Markov evolutions of particle systems in continuum. This scheme is based on a
proper scaling of corresponding Markov generators and has an algorithmic
realization in terms of related hierarchical chains of correlation functions
equations. Several examples of the realization of the proposed approach in
particular models are presented.Comment: 23 page
Correlation functions evolution for the Glauber dynamics in continuum
We construct a correlation functions evolution corresponding to the Glauber
dynamics in continuum. Existence of the corresponding strongly continuous
contraction semigroup in a proper Banach space is shown. Additionally we prove
the existence of the evolution of states and study their ergodic properties
Markov Process of Muscle Motors
We study a Markov random process describing a muscle molecular motor
behavior. Every motor is either bound up with a thin filament or unbound. In
the bound state the motor creates a force proportional to its displacement from
the neutral position. In both states the motor spend an exponential time
depending on the state. The thin filament moves at its velocity proportional to
average of all displacements of all motors. We assume that the time which a
motor stays at the bound state does not depend on its displacement. Then one
can find an exact solution of a non-linear equation appearing in the limit of
infinite number of the motors.Comment: 10 page
Acid and Acid-Alkali Treatment Methods of Al-Chloride Solution Obtained by the Leaching of Coal Fly Ash to Produce Sandy Grade Alumina
Sandy grade alumina is a valuable intermediate material that is mainly produced by the Bayer process and used for manufacturing primary metallic aluminum. Coal fly ash is generated in coal-fired power plants as a by-product of coal combustion that consists of submicron ash particles and is considered to be a potentially hazardous technogenic waste. The present paper demonstrates that the Al-chloride solution obtained by leaching coal fly ash can be further processed to obtain sandy grade alumina, which is essentially suitable for metallic aluminum production. The novel process developed in the present study involves the production of amorphous alumina via the calcination of aluminium chloride hexahydrate obtained by salting-out from acid Al-Cl liquor. Following this, alkaline treatment with further Al2 O3 dissolution and recrystallization as Al(OH)3 particles is applied, and a final calcination step is employed to obtain sandy grade alumina with minimum impurities. The process does not require high-pressure equipment and reutilizes the alkaline liquor and gibbsite particles from the Bayer process, which allows the sandy grade alumina production costs to be to significantly reduced. The present article also discusses the main technological parameters of the acid treatment and the amounts of major impurities in the sandy grade alumina obtained by the different (acid and acid-alkali) methods. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 18-79-00305Funding: This work was financially supported by the Russian Science Foundation Project No. 18-79-00305
Review of overall parameters of giant radio pulses from the Crab pulsar and B1937+21
We present a review of observed parameters of giant radio pulses, based on
the observations conducted by our group during recent years. The observations
cover a broad frequency range of about 3 octaves, concentrating between 600 and
4850 MHz. Giant pulses of both the Crab pulsar and the millisecond pulsar
B1937+21 were studied with the 70-m Tidbinbilla, the 100-m GBT, 64-m Kalyazin
and Westerbork radio telescopes. We discuss pulse energy distribution,
dependence of peak flux density from the pulse width, peculiarities of radio
spectra, and polarization properties of giant radio pulses.Comment: 3 pages, 4 figures, to be published in the Proceedings of the
conference "40 Years of Pulsars: Millisecond Pulsars, Magnetars, and More"
held on August 12-17, 2007, McGill University, Montreal, Canad
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