Search

Colloidal CdS nanoparticles measuring 1.9-2.3 nm and stabilized by guanidine-containing dendrimers were produced. It was established that such nanoparticles are characterized by photoluminescence in a wide spectral range (2.1-3.2 eV) with an average radiative lifetime of 55-85 ns depending on the energy of the emitted quanta and also by electroluminescence in the visible region of the spectrum (1.8-2.8 eV).

The evolution of the Black and Caspian seas is considered based on the analysis of new stratigraphic and paleogeographic data. Three transgression stages (Karangatian, Surozh, Black-Sea) and two regression stages (Post-Karangatian and New-Euxinian) were characterized for the Black Sea, as well as four transgression stages (late Khazarian, early Khvalynian, late Khvalynian, and New-Caspian) and three regression stages (Atelian, Enotaevkan, Mangyshlakian), for the Caspian Sea. The analysis of data on the absolute age of deposits allowed correlation of paleogeographic events for the basins, between them and with the stages of the Last (Valdai) Glaciation: the Karangatian and late Khazarian transgressions were correlated with the Mikulinian Interglacial; the post-Karangatian and Atelian regressions, with the Kalininan glaciation; the early Khvalynian and Surozh transgressions, with the middle Valdai Interstadial; the New-Euxinian and Enotaevkan regressions, with the Ostashkovian glaciation; the Black Sea, late Khvalynian, and New-Caspian transgression, with the late glaciation — post-glaciation periods; the Mangyshlakian regression, with the Older Dryas (?). The last connections between the Caspian and Black seas are dated to the middle Valdai time when waters of the early Khvalynian basin drained down to the Surozh basin.

The analysis of paleontological remains in many samples from the Lower Quaternary Chauda sediments drilled and cored on the Bulgarian shelf of the Black Sea revealed widespread mollusks of the genera Didacna and Dreissena (Didacna tschaudae guriana, D. tschaudae, D. pleistopleura, D. crassa guriensis, Dreissena rostriformis tschaudae, D. rostriformis abchasica) accompanied by reworked Neogene representatives of the genus Digressodacna. In numerous places of a continental slope and an adjacent deep-sea depressions near Crimea and Caucasus the similar mollusc assemblage is described in the redeposited state for the first time. The composition of palynological spectra and diatom assemblages in shelf sediments indicates climate changes during the Chaudan period. The Chaudan mollusk fauna from the Black Sea sediments, which is lacking Caspian Bakuan species characteristic of the Chauda stratotype, is compositionally close to the mollusk assemblage from basal layers of the Chauda Horizon in the Guriya area of Georgia (“Gurian” Chauda). These data imply repeated changes in the level of the Chaudan basin between present-day isobaths of −30...−50 to −140 m.

Existing systems for melting glazed frost on overhead electric transmission lines are analyzed. To prevent the formation of glazed frost, without disconnecting the line, it is proposed to insert an appropriate voltage-boosting transformer into the line. The effectiveness of such a system of preventing the formation of glazed frost in a specific network is demonstrated.

Based on data of high-resolution acoustic profiling performed in the upper part of the sedimentary succession at the western continental slope of the Middle Caspian Sea (at a depth range from 100 to 400 m), we revealed specific accumulative forms of a running wave type. Examination of their morphology and inner structure allowed us to suggest two mechanisms of their formations: (a) by means of flank growth due to migration of channels of sedimentary flow associated with the Samur and other rivers and (b) due to flows of sedimentary material forming sedimentary waves.

Structural specific features of the sedimentary succession on the continental margin of the South Crimea in the Black Sea have been examined in the Yalta Area using geomorphologic, acoustic, and lithologic methods. Alternation of regressive and transgressive sequences has been ascertained in sediment sections formed on the shelf and in the Yalta deep-sea fan due to Quaternary oscillations of the basin level. The analysis of sediment sections resulted in revealing a leading role of sedimentary material transference from upper hypsometric levels to lower ones in the sediment accumulation.

The character of changes in the mollusk fauna in the Late Pleistocene and Holocene sediments within the Bulgarian, Northwestern, Crimean, and Kerch segments of the Black Sea shelf has been examined. A bed containing fossil remains of brackish-water and marine mollusks was recognized in these sediments; the bed accumulated, based on results of radiocarbon datings, 500–1000 years ago. The obtained data do not support the existing notion of a catastrophic fill-up of the Black Sea Basin by marine Mediterranean water [19].

An experiment is conducted on the diffusion of arsenic or phosphorus from an RF plasma into a porous-silicon film intended to serve as a source for the next diffusion step, the film being made by plasma etching or electrolytic anodization. The ultimate goal is to reduce the wafer temperature. It is shown that much lower temperatures are indeed possible with the diffusion technique considered. It is established that doping concentration is more uniform over the wafer surface if pores are arranged regularly, as with porous silicon produced by plasma etching. It is also established that plasma-assisted diffusion is mainly affected by the dispersion of pores in size, total pressure, the partial pressure of the doping agent (AsH3 or PH3), RF power, and wafer temperature. Porous-silicon films doped with As or P by plasma-assisted diffusion could be employed in power devices.

We have extended the experimental approach, used by Yu. A. Nastyshyn et al. [J. Appl. Phys. 86 , 4199 (1999)] for measuring polar anchoring strength, to measure the twist elastic constant in nematic liquid crystal. The method implies measurements of phase retardation changes in liquid crystal under the action of magnetic field. The obtained experimental data were fitted with the predictions of elastic theory. We found that the value of the measured elastic constant, K_{22} , is in good agreement with those described in literature.

New N-arylidene (S)-1-phenylethylamines with ester group in arylidene fragment have been synthesized. The chiral dopants helical twisting power and temperature dependence of the induced cholesteric helical pitch in LC systems based on 4-pentyl-4′-cyanobiphenyl have been studied as well as selective light reflection spectra and their temperature dependences for systems including nematic E63 (Merck) and new chiral components. An influence of the chiral dopant molecular structure on the mentioned characteristics of LC systems investigated was revealed. The induced cholesteric compositions with temperature-independent selective light reflection in visible range have been obtained.

Chiral dopants are optically active substances used in liquid crystal systems. We have investigated the helical twisting power and its temperature dependences for the systematic rows of optically active organic compounds synthesized on the base of 2-methylbutanol and e-menthol. The compounds differ by molecular, chemical and spatial structure. Correlation between the value of helical twisting power and molecular structure of chiral dopants is analyzed. The mesogenity of new chiral dopants is also discussed.

Comparison of electrooptic characteristics of LCD's with orienting structures made by vacuum and non-vacuum methods is demonstrated

The problem of one-dimensional propagation of low-frequency electromagnetic waves in homogeneous ionospheric plasma at an angle to the external magnetic field is examined. An oscillating pulse function is obtained for such waves. The shape of the envelope is determined by the Pedersen conductivity. The oscillation period increases with distance and the angle between the propagation direction and the external magnetic field. The period is determined by the Hall and Pedersen conductivities and varies from tenths of a second to seconds.

[1] The coupling between the atmosphere and lower ionosphere (due to either the DC electric field or atmospheric gravity waves) may lead to the formation of horizontal irregularities of ionospheric conductivity over an earthquake preparation region. Such interaction of these irregularities with the background electromagnetic noise leads to occurrence of periodic polarization electric currents. These currents are considered to be a coherent source of gyrotropic waves propagating in the ionospheric conducting layer with finite thickness. The theoretical estimation has been performed on the generation of those ionospheric micropulsations in the frequency range of ULF to ELF in the equatorial latitude with horizontal Earth's magnetic field. Then it is found that those waves appear as a narrow-banded line spectrum in the frequency range from 1 to 30 Hz, and these waves are expected to be observed on Earth's surface.

Thermal and degradation stability of SiOx aligning films deposited by reactive cathode sputtering (RCS) in glow discharge plasma has been investigated. It is shown that heat treatment and other external factors initiate transformations on the surface of aligning film and formed new conditions on the interface. It is lead to change of easy axis orientation direction of LC molecules and appearance of various defects in the LC aligned structures. The technological ways for increasing of aligning layers durability under influence of external factors has been proposed.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Technology of SiO:In,Sn aligning films deposited by reactive cathode sputtering (RCS) method is presented. The influence of In, Sn alloy surface concentration in Si cathode target on aligning film properties are investigated by theAFM and optical profilometry methods. The properties of aligning microrelief obtained by RCS method for different In,Sn concentration and by poliimid rubbing method are compared. It was shown that such aligning microrelief can createdefectless and perfect on the microscopic level nematic LC oriented structures.Keywords: reactive cathode sputtering, aligning films, nematic liquid crystal, microrelief, AFM 1. INTRODUCTION In present LCD production a lot of techniques for creation of the planar or tilted homogeneous alignment of liquid crystal molecules (such as vacuum thermal deposition or electron beam evaporation of oxides, rubbing of the polymerfilms, photoalignment, plasma treatment and others [1 — 6]) are using. But these technologies have a lot of imperfections.For example, rubbing of polymer coatings generate of dust particles and high static voltage, mechanical and electricaldamaged ofthe active matrix elements (thin film diodes or TFT), required to use high temperatures (up to 2800C) andlong-term (several hours) processes for imidization. Several years ago, in the Institute of Semiconductor Physics of NASUkraine the essentially new vacuum method for creation ofaligning layers was proposed [7,8]. This method is based onthe reactive cathode sputtering ofsilicon target in glow discharge plasma in argon and oxygen atmosphere [9].In this work investigation results of the new original technology for creation of aligned LC structures based on reactivecathode sputtering (RCS) were presented.

Orienting properties of thin inorganic oxide films created by the method of reactive cathode sputtering in glow discharge plasma are demonstrated. The quality of homogeneous and twist alignment of nematic LC was evaluated by polarization microscopy methods. For comparison of orienting properties of silicon oxide films, the parameter of twist orientation quality was used, and its dependence on technological parameters of sputtering (such as cathode voltage, discharge current density, deposition angle, content of gas atmosphere) was shown. The morphologies of SiOx orienting layers deposited on substrates with different coatings are demonstrated.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Multi-color surface stabilized reflective cholesteric displays with three primary colors: blue, red and green are investigated. The basic methods for compensation of deviation in electro-optical characteristics for the different concentrations of optically active additive are discussed. Possibility of application of such displays in high information content big LCD boards with passive matrix addressing is demonstrated.

The bacteriophage designated RD2 has been isolated from the sewage in Rostov-on-Don city and studied. The morphology of bacteriophage particles and the biological properties of the bacteriophage make it related to the plague bacteriophage isolated by D'Errel. The molecular masses of the compared bacteriophages are almost identical being 26.4 +/- 0.4 Md for RD2 and 24.7 +/- 0.2 Md for D'Errel bacteriophage. The DNAs of the bacteriophages share 80% of homology and possess 15 nonhomologous regions scattered along the genomes. The phages are serologically related. The DNAs of both bacteriophages give the similar pattern of hydrolysis by restriction endonuclease EcoRV, but have the different sensitivity to many other restriction endonucleases. The protein specter of bacteriophage RD2 contains 18 polypeptides (11 minor ones), while the one of D'Errel bacteriophage contains 7 polypeptides similar in molecular mass with the polypeptides of RD2. The bacteriophage RD2 cannot be considered one of the plague causative agents of bacteriophages since the region where it has been isolated has a long epidemiological and epizootical record of absence of plague.

The use of different schemes of albino mice immunization either by living or by killed preparations of the vaccine strain of Francisella tularensis when obtaining monoclonal antibodies to the tularemia microbe made it possible to reveal definite regularities in the dynamics of antibody formation. The highest titres of antibodies in sera of animals-donors of splenocytes were obtained during the daily (for 3 days) intraperitoneal immunization of mice with living vaccine or with its thrice administration to the spleen thrice with the interval of 10 days. Revaccination against a background of high titres of antibodies decreased their quantity in blood serum of mice, while that against a background of low titres increased them.

The lifetime of high-power (430–460 mW, λ =0.98 μm) heterolasers was investigated at T = 70oC. Slow degradation as well as sudden failure, characterised by a lognormal distribution, were observed. A statistical calculation was made of the maximum lifetime of heterolasers: it was found to be 5430 h at 70oC for a pump current of 1 A.

The oscillations of thin conducting films placed in a magnetic field are considered. The effect of the field in different directions on the effective elasticity of the film is described and dispersion relations are obtained for longitudinal and transverse waves.

(1985). STRATIGRAPHY OF SEDIMENTS OF THE CENTRAL AND EASTERN MEDITERRANEAN SEA. International Geology Review: Vol. 27, No. 5, pp. 546-551.

1. By rechromatography on sulfoethyl-Sephadex C-50, an electrophoretically homogeneous preparation of cholinesterase has been obtained from the venom ofNaja oxiana Eichwald.

Four Y. enterocolitica strains (10166, 10373, 2119, 5513) have been studied for the presence of the enzymatic systems of modification-restriction (M-R). As revealed with the use of cross titration, strains 10166 and 10373 contain M-R systems, supposedly of type II.

Molecules of the plasmids pBR322 and pRD17 have been compared by electron microscopy technique of R-loops visualization. Comparative location of R-loops on the plasmids has been computerized on minicomputer HP9825A due to the program making possible to define the coordinates of the transcription start and direction. The 5.1 kb fragment coding for pesticin I and immunity protein to pesticin I and cloned in pBR322 vector plasmid is flanked by Bam HI-EcoRI sites. Five promoter regions and direction of transcription were localized on the fragment.