Neighborhood unions and the cycle cover number of a graph

For several years, the study of neighborhood unions of graphs has given rise to important structural consequences of graphs. In particular, neighborhood conditions that give rise to hamiltonian cycles have been considered in depth. In this paper we generalize these approaches to give a bound on the smallest number of cycles in G containing all the vertices of G. We show that if for all x, y ? V(G), |N(x) ∩ N(y)| ≧ 2n/5 + 1, then V(G) is coverable by at most two cycles. Several related results and extensions to t cycles are also given.     

A procedure for clean deposition of100Pd on surfaces

For a program of surface and interface experiments with the PAC isotope¹⁰⁰Pd, a procedure has been developed to chemically separate¹⁰⁰Pd from irradiated rhodium and deposit it on surfaces by evaporation under UHV conditions. First results have been obtained for¹⁰⁰Pd on an Ni(111) surface.     

Towards understanding the increase in strength of thermotropic polyesters with heat treatment

Thermotropic copolyester fibers of oxynaphthoate and oxybenzoate have been subjected to conditions that promote solid-state polymerization as well as annealing. The annealing process causes the crystals to perfect with a simultaneous increase in heat of fusion and melting temperature. Solid-state polymerization, a reaction rate-controlled process, causes the polymer viscosity average molecular weight to increase by chain extension from about 14,000 g/mole to more than 87,000 g/mole with a simultaneous impressive increase in tenacity from about 10 g/d (1.2 GPa) to almost 30 g/d (3.7 GPa). To understand the changes in mechanical properties, we have modeled the fiber structure as short rod-like molecules poorly bonded to a continuous matrix of parallel molecules. Lengthening of the reinforcing molecules facilitates better transfer of load from matrix to molecules, resulting in higher tenacity fibers. © 1994 John Wiley & Sons, Inc.     

Spectrophotometric study of holmium complexation in KOH solutions at 25°C

The complexation of Ho³⁺ in HoCl₃ and KOH solutions at 25°C and saturated vapor pressure was studied by an indicator spectrophotometric technique, and the pH values of the investigated solutions were determined. The stability constants of the hydroxo complexes of Ho³⁺ were measured over a range of pH 9.25–10.10 and at μ≤ 4 × 10^?4 and extrapolated to zero ionic strength.     

The limit distribution of the maximal deviation of a spline estimate of a probability density

One finds the limit distribution of the maximum absolute value of the normalized deviation of a spline estimate from an unknown probability density.Translated from Veroyatnostnye Raspredeleniya i Matematicheskaya Statistika, pp. 447–467, 1986.     

On the mechanism of phenol ozonolysis

The mechanisms of liquid-phase phenol ozonation are revised. A new mechanism in which a significant role is played by free-radical reactions is suggested for this process.