Influence of image forces on charge-dipole interaction in two-layered systems.

Interaction between a fixed point electric charge Q and a freely rotating point electric dipole with the magnitude P pinned near a plane interface between two dispersionless insulators with different dielectric permittivities ɛ1 and ɛ2 has been considered. It was shown that, as a result of this interaction and the interaction of the dipole with the polarization charges induced at the interface by the charge Q and the dipole itself, there arise regions where the dipole can possess either one or two equilibrium orientations. The spatial distributions of the electrostatic dipole energy Wtotal under the combined action of the charge Q and the induced interface polarization charges, as well as the equilibrium dipole orientations (orientation maps), the boundaries between the regions with different numbers of dipole orientations, and their evolution with the variation of problem parameters (the charge and dipole magnitudes, the mismatch between ɛ1 and ɛ2, and the charge-interface distance) were calculated.

Hierarchical Structuring of Black Silicon Wafers by Ion-Flow-Stimulated Roughening Transition: Fundamentals and Applications for Photovoltaics.

Ion-flow-stimulated roughening transition is a phenomenon that may prove useful in the hierarchical structuring of nanostructures. In this work, we have investigated theoretically and experimentally the surface texturing of single-crystal and multi-crystalline silicon wafers irradiated using ion-beam flows. In contrast to previous studies, ions had relatively low energies, whereas flow densities were high enough to induce a quasi-liquid state in the upper silicon layers.

[Means of developing personnel potentials of dental orthopedic service in southern regions of Tiumen' oblast].

The article exposes overall analysis and objective evaluation of personnel potential of orthopedic dental service in southern region of Tyumen oblast. Actual issues of enhancement of orthopedic dental service in this region are discussed.

[Optical density of the mandibular head in cases of TMJ dysfunction and asymmetry of masticatory muscles activity].

There was an examination of 20 patients (12 women and 8 men), aged 30 to 50, with TMJ dysfunction and with partial absence and abrasion of teeth with decrease in the height of the lower facial part and distal mandible shift, and of 12 people (7 women and 5 men), aged 20 to 40, with intact dentitions using electromyography of masticatory muscles and computer tomography, followed by evaluation of the optical density of mandibular head. Analysis of the results enabled to determine the presence of disorders of the balanced activity of masticatory muscles and enables to determine alterations in the optical density of mandibular head. It is necessary to consider the obtained data in planning the prosthetic treatment and preparation of the mouth for prosthetics of patients with TMJ pathology.

[Biomechanical grounds for use of lower molar segments after tooth preservation operations].

The mathematical modeling and clinical testing of results of usage of low molar segments as supporting elements after tooth preserving surgery have been made. After hemisection and crown-radicular separation the critical load for low molar segments is more than 30 kg; after root amputation the critical load for low molar segments is more than 18 kg. The mathematical modeling, clinical observation, and X-ray photography have shown that the remained supporting system of low molars provides a full functioning of the teeth-jaw system after crown radicular separation and hemisection tooth preserving surgery.