Monte Carlo Study of Particle Transport Problem in Air Pollution

2002 Mathematics Subject Classification: 65C05.The actual transport of the air pollutants is due to the wind. This normally called “advection of the air pollutants”. Diffusion and deposition are other two major physical processes, which take place during the transport of pollutants in the atmosphere. In this paper we study two classes of grid-free Monte Carlo (MC) algorithms for solving an elliptic boundary value problem, where the partial differential equation contains advection, diffusion and deposition parts. The grid-free MC approach to solve the above equation uses a local integral representation and leads to a stochastic process called a random “Walk on balls” (WOB). In the first class of algorithms, the choice of a transition density function in the Markov chain depends on the radius of the maximal ball, lying inside the domain, in which the problem is defined, and on the parameters of the differential operator. While the choice of a transition density function in the second class of algorithms does not depend on the deposition part of the problem. The computational complexity of both classes of grid-free MC algorithms was investigated using varied numerical tests on a PowerPC (G4 w/AltiVec) 450 MHz running YDL 2.0.Supported by Center of Excellence BIS-21 grant ICA1-2000-70016 and by the NSF of Bulgaria under Grants #I 811/98 and #MM 902/9

A Stochastic Approach for Investigation Ultrafast Phenomena in Semiconductors

2002 Mathematics Subject Classification: 65C05In this paper a stochastic approach is proposed for investigation the ultrafast evolution of electrons interacting with phonons in the presence of an applied electric field. The quantum-kinetic equation describing the above ultrafast phenomena contains polynomial non-linearity which allows to use the link between non-stationary iterative processes and the branching stochastic processes. The considered stochastic approach relies on the numerical Monte Carlo (MC) theory as applied to the integral form of the quantum-kinetic equation and estimates the electron energy distribution using statistical averages over long evolution times. The numerical tests were performed for GaAs material parameters. The numerical results for the electron energy distribution function in the case of a non-linear electron quantum transport is compared with the obtained results in the linear case.Supported by Center of Excellence BIS-21 grant ICA1-2000-70016 and by the NSF of Bulgaria under Grants # I 811/98 and # MM 902/99

Charged Particles Evaporation in the Stopped Pion Absorption Reactions

In the present work we have analyzed evaporation spectra and yields of p,d,t formed in the reaction of stopped pion absorption. It is shown that the values of equilibrium temperature obtained through the usage of proposed model are in agreement with the values obtained in various other experiments. We also discuss the A-dependences of the evaporation yields and consider possible contributions of the “indirect” evaporation processes

The Religious Ethics Impact as Evaluative Element of Culture on the Personality Development of the Future Teacher: The Person Measurement Approach

Personality measuring today becomes popular as it is a civilization marker for modern cultural and educational changes in society. Theoretical and methodological foundations of measuring the personality are laid in the present study as the leading principle of humanitarian studies. Human measuring approach in modern understanding is presented as a product of neoclassical science. There are shown major human systems, which are directly influenced by the religious ethics

8He Spectroscopy in Stopped Pion Absorption By 9Be

Level structure of 8He has been studied in the reaction of stopped pion absorption by 9Be nuclei. The missing mass spectrum in the range 0 MeV ≤ MM ≤ 10 MeV has been described by the superposition of phase-space distributions and the three states of 8He. Parameters of these states have been compared with data of other experimental and theoretical works

Fractional Systems and Fractional Bogoliubov Hierarchy Equations

We consider the fractional generalizations of the phase volume, volume element and Poisson brackets. These generalizations lead us to the fractional analog of the phase space. We consider systems on this fractional phase space and fractional analogs of the Hamilton equations. The fractional generalization of the average value is suggested. The fractional analogs of the Bogoliubov hierarchy equations are derived from the fractional Liouville equation. We define the fractional reduced distribution functions. The fractional analog of the Vlasov equation and the Debye radius are considered.Comment: 12 page

Search for states with enlarged radii in excited states of 12B

An experiment was done to search for states with a neutron halo in 12B. The measurements were carried out at the cyclotron of the University of Jyvaskyla (Finland) using Large Scattering Chamber (LSC). The idea of the work was to search for two states with the expected neutron halo, 1 ̄ and 2 ̄. Differential cross sections with excitation of 12B states, including abovementioned states, were observed. The preliminary calculations on halo radii by the method of asymptotic normalization coefficients for the 2 ̄ and 1 ̄ states which are in a discrete spectrum gave following values: 5.6 fm and 7.4 fm, which is much larger than the radius of the valence neutron in the ground state. But strictly the presence of a neutron halo can be confirmed only for 1 ̄ state. The 2 ̄ state can be considered only as candidate for halo. An unexpected result was obtained for the 3 ̄, 3.39 MeV state, which is in continuum 19 keV above the decay threshold 12B → 11B + n, preliminary estimation for its halo radius is ∼ 6.5 fm. This indicates that the halo can be present in this state as well. But strict conditions for neutron halo are not fulfilled in the same way as for 2 ̄ state. Until now, the neutron halo in unbound states has been observed only for the members of the rotational bands

Eardrum perforation treatment blood plasma enriched with platelet growth factors

Introduction. The problem of the development of acute post-traumatic otitis media has not lost its relevance. Long-term preservation of the defect of the tympanic membrane contributes to the development of chronic inflammation in the middle ear and a deterioration in the quality of life of patients.Objective. To study the effect of blood plasma enriched with platelet growth factors on the regeneration of the tympanic membrane tissues in patients with acute post-traumatic perforation.Materials and methods. Patients with acute post-traumatic perforation of  the  tympanic membrane were divided into the main (24 people) and control (19 people) groups. Patients of the main group in the area of perforation of the tympanic membrane were injected once by application with a clot of autoplasma, enriched with platelet growth factors. The control group patients underwent dynamic observation of the processes of natural regeneration of the tympanic membrane tissues. On the 5, 10 and 15th days, the tissue regeneration of the tympanic membranes was assessed subjectively (patient complaints, audiometry) and objectively (otoscopy with the calculation of the dynamics of the relative perforation area, otoacoustic emission).Results. A single application of blood plasma enriched with platelet growth factors to the perforation area was significantly more often accompanied by closure of  the  tympanic membrane perforation (p ≤ 0.01) and a  decrease in  the  average relative area of the tympanic membrane perforation on days 10 and 15 of the study (p ≤ 0.01). The dynamics of the average relative area of the tympanic membrane perforation reflected a high rate of closure of the tympanic membrane defect in the main group. Better healing of the tympanic membrane in patients of the main group was accompanied by an improvement in the auditory function of the affected ear. The quality of hearing was, on average, significantly better in the patients of the main group than in the patients of the control group, both on the 10th and 15th days of observation (p ≤ 0.01).Conclusion. Clinical use of blood plasma enriched with platelet growth factors has a beneficial effect on the rate, intensity of closure of the tympanic membrane perforation and hearing