Dynamics of streamer discharge development in semiconductors

Space-time dynamics of streamer discharges in semiconductors in view of processes of shock (tunnel and photo-) ionization, radiating spontaneous and stimulated recombination as well as electron-photon interaction in a strong electric field has been modeled. The possibility of formation in these conditions of space-nonuniform dissipative structures, self-oscillatory regular and other modes were shown; their laws and interrelation with dynamics of streamer laser discharge were established. Nonmonotonic dependence of system characteristics on key parameters - excitation rate, life time of nonequilibrium carriers and photons, quantum efficiency of active environment as well as strengthening of structure interaction in conditions of stimulated recombination causing variety of own system dynamics were revealed. Radiating processes provide high speed of structure distribution compared with phase speed of light, and they are the basic generation mechanism of nonequilibrium carriers generation in self-oscillatory mode respective to optimum conditions of streamer occurrence and developmen

Summing Over Inequivalent Maps in the String Theory Interpretation of Two Dimensional QCD

Following some recent work by Gross, we consider the partition function for QCD on a two dimensional torus and study its stringiness. We present strong evidence that the free energy corresponds to a sum over branched surfaces with small handles mapped into the target space. The sum is modded out by all diffeomorphisms on the world-sheet. This leaves a sum over disconnected classes of maps. We prove that the free energy gives a consistent result for all smooth maps of the torus into the torus which cover the target space $p$ times, where $p$ is prime, and conjecture that this is true for all coverings. Each class can also contain integrations over the positions of branch points and small handles which act as ``moduli'' on the surface. We show that the free energy is consistent for any number of handles and that the first few leading terms are consistent with contributions from maps with branch points.Comment: 17 pages, 5 eps figures contained in a uuencoded file, UVA-HET-92-1

The Color--Flavor Transformation of induced QCD

The Zirnbauer's color-flavor transformation is applied to the $U(N_c)$ lattice gauge model, in which the gauge theory is induced by a heavy chiral scalar field sitting on lattice sites. The flavor degrees of freedom can encompass several `generations' of the auxiliary field, and for each generation, remaining indices are associated with the elementary plaquettes touching the lattice site. The effective, color-flavor transformed theory is expressed in terms of gauge singlet matrix fields carried by lattice links. The effective action is analyzed for a hypercubic lattice in arbitrary dimension. We investigate the corresponding d=2 and d=3 dual lattices. The saddle points equations of the model in the large-$N_c$ limit are discussed.Comment: 24 pages, 6 figures, to appear in Int. J. Mod. Phys.

A preliminary factor analytic investigation into the first-order factor structure of the Fifteen Factor Plus (15FQ+) on a sample of Black South African managers

The original publication is available at http://www.sajip.co.zaMoyo, S. & Theron, C. 2011. A preliminary factor analytic investigation into the first-order factor structure of the Fifteen Factor Plus (15FQ+) on a sample of Black South African managers. SA Journal of Industrial Psychology, 37(1), 1-22, doi: 10.4102/sajip.v37i1.934.Orientation: The Fifteen Factor Questionnaire Plus (15FQ+) is a prominent personality questionnaire that organisations frequently use in personnel selection in South Africa. Research purpose: The primary objective of this study was to undertake a factor analytic investigation of the first-order factor structure of the 15FQ+. Motivation for the study: The construct validity of the 15FQ+, as a measure of personality, is necessary even though it is insufficient to justify its use in personnel selection. Research design, approach and method: The researchers evaluated the fit of the measurement model, which the structure and scoring key of the 15FQ+ implies, in a quantitative study that used an ex post facto correlation design through structural equation modelling. They conducted a secondary data analysis. They selected a sample of 241 Black South African managers from a large 15FQ+ database. Main findings: The researchers found good measurement model fit. The measurement model parameter estimates were worrying. The magnitude of the estimated model parameters suggests that the items generally do not reflect the latent personality dimensions the designers intended them to with a great degree of precision. The items are reasonably noisy measures of the latent variables they represent. Practical/managerial implications: Organisations should use the 15FQ+ carefully on Black South African managers until further local research evidence becomes available. Contribution/value-add: The study is a catalyst to trigger the necessary additional research we need to establish convincingly the psychometric credentials of the 15FQ+ as a valuable assessment tool in South Africa.Publisher's versio

Some New/Old Approaches to QCD

This is a talk delivered at the Meeting on Integrable Quantum Field Theories, Villa Olmo and at STRINGS 1992, Rome, September 1992. I discuss some recent attempts to revive two old ideas regarding an analytic approach to QCD-the development of a string representation of the theory and the large N limit of QCD.Comment: 20 page

Structural and magnetic studies of FE100–xCox nanotubes obtaine by template method

Hollow nanostructures based on the Fe100–xCox alloy were synthesized in the pores of polymer template matrices based on PET using the electrochemical deposition method. Morphology, elemental composition, and structural features were characterized by scanning electron microscopy, energy dispersive analysis, and X-ray diffractometry. The study of the internal magnetic texture was carried out using Mossbauer spectroscopy. The dependence of the change in structural and magnetic properties from the atomic content of components in nanotube structure is revealed. It is established that the synthesized nanostructures are hollow Fe100–xCox nanotubes with a body-centered cubic crystal structure. The decrease in the unit cell parameter with increasing cobalt concentration is due to the difference in the radii of Fe (1.227 Å) and Co (1.191 Å) atoms. It is established that a random distribution of magnetic moments directions of Fe atoms is observed for Fe100Co0 nanotubes. And magnetic texture along the nanotube axis is observed for Fe100–xCox nanotubes, with an increase in Co atoms concentration. The average angle between the direction of the magnetic moment of iron atoms and the nanotube axis decreases from v = 54:6° to v = 24:5°. © 2018, Electromagnetics Academy. All rights reserved

Template synthesis and magnetic characterization of FeNi nanotubes

Iron-nickel nanotubes consisting of 20% Ni and 80% Fe with an aspect ratio of about 100 were synthesized by electrochemical deposition in the pores of polyethylene terephthalate ion-track membranes. The main morphological parameters such as composition, wall thickness and structural characteristics were defined. Macro- and micromagnetic parameters of FeNi nanotubes were determined. © 2017, Electromagnetics Academy. All rights reserved

POWER USE OF WASTE HYDRAULIC ENERGY

In the article considered the question of using of waste hydraulic energy, especiallyin areas with decentralized autonomous electric power supply. As a source of hydraulic energy the authors suggest to use the power of cleaned effluent and reservoirs of non-energy purpose in conditions of Chelyabinsk region.В работе рассмотрен вопрос об использовании сбросной гидравлической энергии, в частности на участках с децентрализованным автономным электроснабжением. В качестве источников гидравлической энергии авторы предлагают использовать энергию очищенных сточных вод и водохранилищ неэнергетического назначения в условиях Челябинской области