Non-stationary crystallization in simple glass-forming materials

A crystal distribution function is established during the crystallization process of simple glass-forming melts on the basis of the numerical computation of the kinetic equation in a non-stationary regime for constant and non-constant temperature. Nucleation rate and time-temperature-transformation curves are determined from the calculations of the crystal distribution function at various constant temperatures for various parameters of the system (the dependence on the difference of the chemical potentials, the dependence on the surface energy etc.).     

The combinatorics of the Baer-Specker group

We study subgroups of ℤ^ℕ which possess group theoretic properties analogous to properties introduced by Menger (1924), Hurewicz (1925), Rothberger (1938), and Scheepers (1996). The studied properties were introduced independently by Kočinac and Okunev. We obtain purely combinatorial characterizations of these properties, and combine them with other techniques to solve several questions of Babinkostova, Kočinac, and Scheepers. The first author was supported by the EU Research and Training Network HPRN-CT-2002-00287. The second author was partially supported by the Koshland Center for Basic Research.     

Isotope dilution analysis in column-coupling isotachophoresis

The use of isotope dilution technique to eliminate problems associated with demands for a high load capacity in column-coupling capillary isotachophoresis was studied. Determinations of phosphate present in a model mixture and in white wine served for the evaluation of this approach to quantitative analysis in isotachophoresis. A high selectivity of the analysis with acceptable accuracy and precision of the determination also in complex ionic mixtures in a short time are obvious advantages of this approach.     

Light scattering by optically heterogeneous materials: Structural aspects of dichromatic laser speckle patterns

An analysis is given of dichromatic speckle patterns formed by small-angle scattered light in the illumination of optically heterogeneous systems with light of two nearby wavelengths. The existence of the radial-fibrillar appearance of the speckle patterns is explained; it is shown that the occurrence of the radial-fibrillar “structure” corresponds to the measurable correlation of dichromatic speckle patterns as specified by the spectral spatial cross-correlation function of intensity fluctuations. A measurement of speckle-pattern correlation to determine σ_z (the standard deviation of optical path fluctuations due to the passage of coherent light through a layer of heterogeneous material) is described, and the relations between σ_z and the structural parameters for two simple types of heterogeneous materials are discussed. Experimental results obtained with a series of samples of polyethylene filled with CaCO₃ are in comparatively good agreement with theoretical values.     

Inverse bi-Hamiltonian separable chains

The procedure for constructing the related inverse counterpart for a given bi-Hamiltonian separable chain is presented. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 122, No. 2, pp. 170–180, February, 2000.     

Forecasting voting behaviour using machine learning – Poland in transition

The aim of the paper is to apply some inductive learning method from examples (which gives explicit decision rules of “if-then” type) to forecast the voting behaviour of individual members of the Polish Parliament. Results obtained are both interesting and promising. This revised version was published online in June 2006 with corrections to the Cover Date.     

Bose–Einstein effect in Z^0 decay and the weight method

We discuss the Bose–Einstein interference effect in multi-particle production. After a short review of various methods of implementation of this effect into Monte Carlo generators the weight method is presented in more detail and used to analyze the data for hadronic decays. In particular, we consider the possibility of deducing the two-particle weight factor from the experimental data. Received: 23 September 1999 / Published online: 3 February 2000