Resonant Phenomena in Slowly Irregular Rectangular Waveguides

A waveguide with a rectangular cross section of size and orientation slowly changing along the length of the waveguide is considered. Methods of the canonical perturbation theory are used to describe the ray dynamics in the waveguide. As the size and orientation of the cross section slowly change along the ray trajectory, certain resonance conditions may be satisfied. The phenomena of scattering on resonance and capture into resonance is studied. These phenomena lead to destruction of the adiabatic invariance in the system. Bibliography: 12 titles.__________Published in Zapiski Nauchnykh Seminarov POMI, Vol. 300, 2003, pp. 173–179     

Role of the microstructure on the transport properties of Y-doped zirconia and Gd-doped ceria

Transmission electron microscopy characterizations and XPS analyses have allowed us to show the influence of the microstructure and nanochemistry on the transport properties of Y₂O₃-(9 mol%)-stabilized zirconia (YSZ) and Gd₂O₃ (10 mol%)-doped ceria (GDC). The grain boundary electrical conductivity (σ_gb) and oxygen diffusion coefficient (D_o) of conventional YSZ ceramics increase with the grain size, while an opposite behavior was found for GDC samples. This difference was attributed to glassy precipitates present at YSZ grain boundaries. Furthermore, it was shown that kinetic demixing processes take place during cooling, at the end of sintering. This causes important changes in the cationic species distribution at interfaces and plays an important role on the transport properties of these two materials. Paper presented at the 9th EuroConference on Ionics, Ixia, Rhodes, Greece, Sept. 15 – 21, 2002.     

Influence of Pretreatment of Expanded Graphite on Its Sorption Properties with Respect to Petroleum

Petroleum sorption on expanded graphite prepared from residual graphite hydrosulfate at 300-900°C was studied as influenced by pretreatment of the sorbent with water.     

Optical and photoelectric properties of helical quantum wires

The appearance of a steady current in a helical quantum wire under circularly polarized light is predicted. The effect is associated with the appearance of a travelling electromagnetic wave in the coordinate system related to the wire, the wavelength being determined by the period of the helix. The gyrotropy of a medium consisting of parallel quantum wires is considered.     

Degradation of Metal 2-Acrylamido-2-methylpropanesulfonate-N-Vinylpyrrolidine Copolymers in Aqueous Solutions Containing Different Cations

The influence of single- and double-charged cations on degradation of metal 2-acrylamido-2-methylpropanesulfonate-N-vinylpyrrolidine copolymers in aqueous solutions in the presence of potassium peroxodisulfate, K₂S₂O₈, at 50 and 70°C was studied by viscosimetry.     

The Use of Corona Discharge for Rubber Crush Drier Exhaust Control

The rubber crush drier exhaust contains mainly styrene, ethylbenzene, cumene, diizopropylbenzene, alkylphenols, monocyclic terpenes and technological additives as stearic acid, oils an colophony. For possible application of d.c. corona discharge to control styrene in exhaust, the reaction of styrene with additives and air in various d.c. corona discharge tubes was studied. The change of styrene content in the gas phase was measured by IR absorption spectrometry. The decrease of styrene concentration was minimum 83% and reached the 98,9% efficiency. No aromatic compounds remain after corona discharge action in gas phase. The structure of solid products was specified with reflection IR absorption spectrometry and compared with a calibration polystyrene foil (300 μm). The main product has been of malein anhydride-styrene copolymer character for a negative corona discharge and of phenol or quinone-styrene copolymer character for a positive corona discharge.     

Noncommutative four-dimensional subalgebras of conformal algebra integrable in the space R1,3

D'alambert's equation is used as an example to study the possibilities of a new method of exactly integrating systems of linear differential equations — the method of noncommutative integration (NI). The results confirm that use of the NI is equivalent to complete separation of the variables in the case of four-dimensional subalgebras of conformal algebra. However, the method does simplify determination of the exact solution in this instance.Tomsk University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 120–124, February, 1995.     

PT violating single particle nuclear potential

We calculate aPT-odd one-loop meson radiative correction to the scattering amplitude of a nucleon on the external field of the nucleus. The nonrelativistic limit of this amplitude, Fourier transformed to the configuration space, can be interpreted as a single particlePT-odd potential for a valence nucleon. Bound state effects on this potential are evaluated and found to be negligible.     

Lie symmetries and exact solutions of nonlinear equations of heat conductivity with convection term

The Lie symmetries of nonlinear diffusion equations with convection term are completely described. The Lie ansatzes and exact solutions of a certain nonlinear generalization of the Murray equation are constructed. An example of the family of non-Lie solutions of the Murray equation is given.