Green's temperature functions of massive scalar particles for finite matter density

An explicit expression is obtained for the Green's functions of a massive scalar field for nonnull temperatures and density in the form of a series in powers of m/T. The equivalence of the spectral-geometric approach and the temperature technique of Matsubara and Bernard is demonstrated. Corrections to the Stefan-Boltzmann law are obtained on the basis of the calculated Green's functions. The energy density is calculated in regions of high and low temperatures. The formulas obtained can prove to be useful in the discussion of the phase transition hadrons-quark-gluon plasma.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 32–40, July, 1991.     

A Tabu Search Approach for Delivering Pet Food and Flour in Switzerland

In this paper, we consider a real-life vehicle routeing problem that occurs in a major Swiss company producing pet food and flour. In contrast with usual hypothetical problems, a large variety of restrictions has to be considered. The main constraints are relative to the accessibility and the time windows at customers, the carrying capacities of vehicles, the total duration of routes and the drivers' breaks. To find good solutions to this problem, we propose two heuristic methods: a fast straightforward insertion procedure and a method based on tabu search techniques. Next, the produced solutions are compared with the routes actually covered by the company. Our outcomes indicate that the total distance travelled can be reduced significantly when such methods are used.     

Crystal and molecular structure of bis(2-isotropyliminomethinylphenyl) telluride

Scientific-Research Institute of Physical and Organic Chemistry, Rostov State University. A. N. Nesmeyanov Institute of Heteroorganic Compounds, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 3, pp. 104–106, May–June, 1991.     

The Most Critical Path in a PERT Network

The classical PERT approach uses the path with the largest expected duration as the critical path to estimate the probability of completing a project by a given deadline. However, in general, such a path is not the ‘most critical’ path and does not provide the smallest estimate for the probability of completion time. This paper studies the ‘most critical path’ problem and formulates it as an optimal path problem in a deterministic network with a two-attribute fractional objective function. An exact solution approach is presented for the optimal path problem which also gives the solution to the most critical path problem. The illustrative examples as well as our computational results demonstrate that the proposed algorithm provides estimates for the probabilities of completion time that are much more accurate than those of the classical approach.     

Variational principles of magnetostatics of superconductors. I

Fundamental and dual variational principles of magnetostatics of superconductors are formulated. It is shown how test fields can be expressed in terms of vector and scalar potentials. General consequences of the variational magnetostatic formulation are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 97–102, September, 1991.     

Phase dynamics of a detuned single-mode laser

We report measurements on the phase dynamics of a detuned single mode laser which has in the past shown correspondence to the complex Lorenz equation. The corresponding ranges of periodic pulsing, of detuned chaos and of windows within the chaotic domain are investigated.Invited paper     

Conflict Analysis in the Politico-Military Environment of a New World Order

A methodology is developed to analyse present and future crisis and conflict potentials of small or large geopolitical regions. A set of criteria is used to describe the present economic, social, political and military conditions of a country and the future criteria trends. A multi-criteria decision analysis model is invoked to compute the crisis and conflict potentials under simultaneous consideration of all other countries in that region. The methodology is demonstrated in the crisis and conflict potentials analysis of the former Soviet republics including bordering countries.     

Structure of fullerene-containing soot at different formation stages of arc discharge vaporization of graphite

Electron microscopy is used in a study of nanoclusters of the carbon soot deposited on a probe in different areas of arc discharge during graphite vaporization under conditions favorable for fullerene synthesis. It is found that the spatial network of soot nanoclusters consists of alternating regions of higher density or associates of carbon particles. Two types of nanoclusters have been identified with the correlation radii of the associates equal to 0.6–0.8 and 1.6–2.2 nm, respectively. Type I nanoclusters are dominant in the soot microparticles, and their structure shows practically no variations with increasing separation r of the soot collector from the discharge axis over the range of distances studied, r=1–9 cm. The effective radius R ₀ of the “elementary” particles making up the associates in the soot nanoclusters of Type I calculated with the use of scaling relationships is 0.15–0.17 nm and is close to the gas-kinetic radius of carbon atoms. Type II nanoclusters have been identified in soot collected at r>3 cm. Values of R ₀ calculated in this case are 0.6–0.9 nm and decrease with increasing r, which indicates the presence of fullerene molecules in these nanocluster associates.