Development of the DIFFRACALC program for analyzing the phase composition of alloys

Crystallography Reports - The DiffraCalc software package is developed for automatic indexing of electron diffraction patterns. The program can operate with the existing base of X-ray diffraction...     

Experimental Investigations of the Conditions for the Formation of the Liquid Crystalline State of Polymers

The diagrams of state for concentrated PBG solution in coordinates relating volume fraction-geometric asymmetry and volume fraction-temperature are investigated. The order parameter for macromolecules in the anisortropic phase is dettermined. The experimental data compare with the existing theoretical models for th formation of the liquid crystalline state in solutions of stiff polymer molecule. It is shown that experimental data are in good quantitative agreement with the Flory's lattice model.     

Methods for the preparation of bimetallic xerogel catalysts designed for chlorinated wastes processing

The aim of this work is to simplify and generalize the synthesis procedure of bimetallic supported catalysts by sol–gel process. For Pd–Ag/SiO₂ co-gelled xerogels catalysts a number of synthesis procedures were compared: use of one or two specific alkoxides able to form a chelate with palladium and/or silver cations, reagent mixing in one or two steps, use of industrial grade chemicals instead of laboratory grade chemicals. The catalysts obtained are quite similar: same metal dispersion, same tailored morphology, same localization and accessibility of Pd–Ag alloy nanoparticles inside microporous silica, same activity and selectivity for hydrodechlorination of 1,2-dichloroethane into ethylene. For catalyst production at large scale the synthesis can be achieved in one step with 3-(2-aminoethyl)aminopropyltrimethoxysilane of industrial grade as chelating alkoxide, tetraethylorthosilicate (TEOS) of industrial grade and ethanol denatured with diethyl phthalate.     

Numerical integration methods for the Takagi-Taupin equations for crystals of rectangular cross section

Two independent methods for calculation of the rocking curves for laterally bounded crystals are developed. Numerical simulation of diffraction for crystals of different sizes is performed. The results obtained using the dynamical theory of diffraction are compared to those obtained in the kinematic approximation.     

Computation of the axial temperature distribution for the travelling heater method

A theoretical model for the computation of the axial temperature distribution for the THM arrangement is described considering the heat flow in radial direction. The calculated temperature distribution is compared with the measured one. The correspondence is sufficient. By means of this model, it is possible to estimate the effect of a change of important growth parameters prior to the experiment. The model also permits a calculation of temperature distributions of other crystal growth methods (e.g. Bridgman, zone levelling, zone melting) by changing the boundary conditions only.     

A Technique for the Characterisation of Langmuir-Blodgett Films

A method has been developed which allows the characterisation of Langmuir-Blodgett films. The technique utilises the liquid crystal aligning properties of the films and may be applied to films composed of any number of layers. Two materials were studied, ω-tricosenoic acid and cadmium arachidate. Differences between one and three layer samples of these materials are discussed and observed defects down to a size of approximately 1–2 microns are illustrated. Tentative explanations for the occurrence of some of the defects are put forward. The results of a preliminary study of electron beam damage in ω-tricosenoic acid are presented.     

A new method for the determination of the orientation of molecules in the unit cell

A new method for the determination of the orientation of organic molecules with partially known stereochemistry in the unit cell is described and compared with the convolution molecule method by Hoppe and Paulus.     

Diophantine laws for nets of the highest symmetries

The theoretical-numerical properties of the square and the hexagonal nets are presented as well as their characteristic triads of integers—the Denis numbers—applicable to the practical X-ray diffraction analysis of single crystals.     

Reflectometer for studying the surface of liquid systems

To study the free surface of liquids, a Reverans reflectometer with a vertical neutron scattering plane has been designed and is fabricated at Petersburg Nuclear Physics Institute. This reflectometer is intended to investigate surfaces and interfaces in liquid magnetic or nonmagnetic systems. The principles of reflectometer operation are described. The general view of the reflectometer with ready units is presented and its main technical parameters are given. The results of preliminary tests are reported.     

Refractories for the glass industry

After a brief review of the evolution of furnaces for the glass industry, the most important refractories used in the different parts of a furnace are described, paying particular attention to electrocast refractories. The properties of these materials are reviewed referring to the relevant chemical compositions and structures. The different parts of the glass-furnace are indicated for which these refractories are recommended, and their behaviour in the presence of different types of glass is evaluated.Recent advances performed on this topic are presented and discussed.     

On the results of the 2009 Struchkov Prize, a competition for Young Researchers, and the announcement of the current (14th) competition for 2010

Information

On the results of the 2009 Struchkov Prize, a competition for Young Researchers, and the announcement of the current (14th) competition for 2010