Showing papers by "Matej Bel University published in 1997"

Exponents of orientable maps

Abstract: We generalize the idea of reflexibility of a map on a surface by introducing certain integers as its ”exponents“. An exponent is any integer with the property that changing the cyclic permutation of edges around each vertex induced by the map to its -th power gives rise to an isomorphic map. The exponents reduced modulo the least common multiple of the vertex valencies form an Abelian group, the exponent group of the map . Along with the automorphism group, the group in fact provides an additional measure of symmetry of ~.The paper is devoted to developing the fundamentals of the theory of exponent groups of maps. Motivation comes from the problem of classification of regular maps with a given underlying graph. To this end, we prove that the number of non-isomorphic regular maps (if any) with a given underlying graph and the same map automorphism group is . We calculate the exponent groups for some interesting families of regular maps including complete maps. Special attention is paid to the problem of how the antipodality of a map is reflected by its exponent group. In the final section we discuss several open problems.1991 Mathematics Subject Classification: 05C10, 05C25, 20F32.

CCSD(T) expectation value calculations of first-order properties

Abstract: An expectation value approach to calculations of first-order properties using the non-iterative, triple-excitation amplitudes in the coupled cluster wave function is exploited. Three methods are suggested and analysed using the many body perturbation theory (MBPT) expansion arguments. The first method, in which non-iterative triple-excitation amplitudes are used in the expression for the expectation values, makes the wave function accurate through the second order of MBPT. In the second method, which is an extension of the first, effects of triple-excitation amplitudes are coupled with single- and double-excitation amplitudes. The correlated density matrix equivalent through the fourth order to that obtained when CCSDT-la amplitudes are used is employed in the third method. The suggested methods are tested on dipole moment and polarizability calculations for several diatomic closed-shell molecules and are compared to other related approaches.

There are no piecewise linear maps of type 2

Abstract: The aim of this paper is to show that there are no piecewise linear maps of type 2∞. For this purpose we use the fact that any piecewise monotone map of type 2∞ has an infinite ω-limit set which is a subset of a doubling period solenoid. Then we prove that piecewise linear maps cannot have any doubling period solenoids.

All maps of type 2^{∞} are boundary maps

Abstract: Let f be a continuous map of an interval into itself having periodic points of period 2n for all n ≥ 0 and no other periods. It is shown that every neighborhood of f contains a map g such that the set of periods of the periodic points of g is finite. This answers a question posed by L. S. Block and W. A.

Further studies on model radioactive wastewaters by reverse radiometric flow injection analysis

Abstract: Rapid, safe and cost effective techniques for study of radiochemical wastes have been investigated by many workers. This work deals with a further study on this aspect by reverse radiometric flow injection analysis (rRFIA) technique.137Cs and60Co were determined in model radioactive wastewaters.

Heavy element contamination of surface waters in the region Banská Štiavnica (SR) measured by radionuclide X-ray fluorescence analysis

Abstract: Heavy metals (Pb, Cd, Mn, Cu, Zn, Fe) were determined in surface waters in the surroundings of the depositories of the mining shrubs in the region of Banska Stiavnica (SR) by radionuclide X-ray fluorescence analysis. Allowed concentrations of the determined metals are exceeded numerously (multiplicity in some cases was 103–106).

Radionuclide x-ray fluorescence determination of cr, fe, cu, zn and pb in industrial wastewaters after preconcentration of determined elements

Abstract: Radionuclide X-ray fluorescence analysis was used for the determination of Cr, Fe, Cu, Zn and Pb in industrial wastewaters (from surface treatment of metals and glasses) after precipitation of determined elements by 8-hydroxyquinoline.

Radionuclide X-ray fluorescence determination of Mn, Fe, Cu, Zn and Pb in wastewaters and sludges from wastewater treatment plants in Bratislava (SR)

Abstract: Radiometric X-ray fluorescence analysis was used for the determination of Mn, Fe, Cu, Zn and Pb in wastewater and sludges from three wastewater treatment plants in Bratislava (SR). Metals were determined in wastewaters after preconcentration by 8-hydroxyquinoline and in sludges by drying and pressing to pellets.238Pu and109Cd was used for excitation of fluorescence radiation.