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A comparative analysis of sections of soil columns from the northern part of the Black Sea and the Northern and Middle Caspian Sea was performed. In the Black Sea, the New, Old Black Sea and New Evksin sediments were identified, the features of their lithological composition were revealed and the age of 14C was established. Shallow and deep-water Novocaspian, Mangyshlak, Verkhnekhvalynsky, Nizhnekhvalynsky, Athelsky and Hyrkan horizons are identified and correlated in the Caspian Sea. As a result, the identity of the structure of the continuous deep-water sections of the compared reservoirs and the synchronicity of the Novoevksin and Late Khvalyn layers are established, which suggests the absence of a connection between the Novoevksin and Early Khvalyn seas.

The sections of boreholes and sediment cores in the Taman shelf area and on the Caucasian continental slope, which uncovered shallow and deep-water facies of the interglacial Karangate horizon, were studied. The shallow-water sediments include clayey and sandy-shell varieties containing stenohaline marine molluscan fauna. Deep-water sediments are represented by sapropelic and coccolithic layers with a marine flora of diatom algae and coccolithophorids.

Background. Helicobacter pylori-associated chronic gastritis (CG), being a very heterogeneous group, still does not have a divisin based on Helicobacter pylori (Hp) genotyping data, which could predict the clinical form of CG.The aim of the study is to search for the prevalence of the cagA gene or any allelic combination of the vacA gene, or stable combinations of cagA and any allelic combination of vacA genes in Hp isolates from patients with mild and severe CG, as well as patients with peptic ulcer disease (PUD).Methods. Hp isolates from gastrobiopsy specimens were genotyped for cagA and vacA allelic combinations (s1m1, s2m1, s1m2, s2m2). The difference in the occurrence of vacA allelic combinations was assessed by Mann–Whitney U test; the conjunction of cagA and vacA allelic combinations was assessed by the Spearman's rank correlation coefficient (rs).Results. The cagA gene was found in more than half of all cases, both in patients with ulcer and in patients with CG (mild and severe). The incidence of vacAs1m1 (the most virulent allelic combination) showed no significant differences in all forms of gastritis and in PUD; the correlation between cagA and vacAs1m1 was significant in all groups of patients, rs ranged from 0.57 to 0.72. In patients with mild CG, an abundance of non-virulent allelic combination vacAs2m2 was observed, which was significantly different from its occurrence both in patients with severe CG and in patients with ulcer; the joint occurrence of vacAs2m2 and cagA in patients with mild CG was chaotic (rs=-0.13; P=0.40).Conclusion. In mild CG, despite the absence of significant differences in cagA and vacAs1m1 (when compared with severe CG and ulcer disease), strains with a non-virulent allelic combination vacAs2m2 were significantly dominant; therefore, the detection of this particular allelic combination of vacA speaks in favor of a mild course of CG.

The Caspian Sea is the world's largest lake noted for a unique history of its evolution in the past. One of most important events in the Caspian history is the Atelian regression. The purpose of this work is to specify the extent, the time, and environments of the Atelian regression, as well as its correlation with events in the adjacent regions, on the basis of multidisciplinary studies of the Atelian deposits penetrated by engineering boreholes in the Northern Caspian. Processing of two-frequency seismoacoustic profiles permitted to stratify the sequence and to perform a spatial correlation between the determined boundaries of the sedimentary series. The laboratory studies included lithological and geotechnical analysis of the cores, floristic and faunal studies of the organic remains extracted from the cores, as well as analyses of pollen and spores, the isotope and radiocarbon (14C) analysis. In the seismic-acoustic profiles Atelian regression is represented by erosional landforms (incisions) under the reflecting horizon at the base of Khvalynian sediments. The regressive series is noted for inhomogeneous lithology. In depressions they are represented by interlayered clays and clay loams. The elevations between the depressions are composed of loamy sands in association with loams. Plant detritus occur as separate inclusions, or forms layered concentrations; there are also shells of freshwater and terrestrial mollusks. The paleontological material suggests aquatic or wetland environments with freshwater or freshened brackish-water shallow water bodies. The palynological materials provide evidence of diversified landscapes in the northern Caspian Lowland at the time of the Atelian regression – from forests dominated by conifers to periglacial forest-steppe and tundra-forest-steppe, mostly resulting from the climate fluctuations. The redeposited pollen is present in abundance, often well-preserved, indicative of highly active erosion at the time of regression. The Atelian regression maximum and the erosional processes on the northern Caspian Lowland correspond to the maximum cooling of the Kalinin (MIS 4) glacial time. The final stages of the regression fell on the initial phases of the MIS 3 interstadial. As follows from materials obtained by seismic-acoustic profiling and drilling, the Caspian level dropped to −100 m. We attribute the sea level lowering to the Caspian (Hyrcanian) water discharge through the Manych into the Pontian basin and to the specific glacial environment during the Valday (MIS 4) time. The Atelian regression maximum is correlatable with the maximum of the post-Karangatian regression of the Black Sea. It was at the same time that the lacustrine Burtass (Gudilo) series were deposited in the Manych depression. In the stratigraphic scheme of the Caspian Sea the Atelian regressive horizon (as a stratigraphic unit) is positioned between Hyrcanian and the base of Lower Khvalynian deposits. In the Northern Caspian the continental Atelian formation spans a greater chronological interval and should be considered as a suite (or formation) in the regional stratigraphic scheme. A comparison between the position of Atelian deposits in the Pleistocene sequence within the sea basin and on the dry land supports the assumption that the geological records exposed in the coastal zone are incomplete. Only a thorough analysis of the materials obtained from the offshore drilling and from the sequences studied in exposures on land can give a comprehensive picture of the history of regional environments and present them correctly in a stratigraphic scheme.

Relevance. If we reduce the treatment exclusively to the eradication of Helicobacter pylori (Hp), the question of monitoring the results of anti-Hp therapy is controversial, given the widely known data on the detection of Hp, including virulent strains of Hp, in most healthy individuals.The aim of the study: to track the dynamics of stomach colonization with various Hp strains in patients with gastric ulcer and duodenal ulcer (PUD) immediately after the use of standard three-component anti-Hp therapy (AHT) and 1.5–2 months after AHT.Methods. Genotyping of Hp strains was carried out by the VNTR method together with the determination of the cagA gene.Results. Assessment of the results of AHT in the form of «eradication of Hp — re-detection of Hp» (i. e., without taking the determination of Hp strains into account) showed less reliability in the differences than the «eradication — preservation of the strain or change of the strain» score in patients with PUD; in addition, the differences between the initial bacteriological picture and that observed immediately after AHT were on the verge of reliability, while the differences between the initial bacteriological picture and that observed after 1.5–2 months had a high degree of reliability. The number of eradications increased (eradication achieved immediately after AHT was not preserved, except for one) and the number of cagA-containing strains decreased (due to new eradication detected at late follow-up periods and due to a change in strains) in long-term follow-up in patients with PUD.Conclusion. Since all patients with PUD achieved clinical remission, which lasted for the next 1.5–2 months, the success of AHT should not be unambiguously associated with the eradication of Hp; the restoration of the organism's colonization resistance to Hp after a course of therapy is more likely.

Developed in this work are the principles for creation of a system to control and governing the energy efficiency of solar panels providing power supply for LED luminaires. Realization of these principles allows the most efficient using the electric power generated by solar panels, to save in a real-time scale the data about system functions as well as provide a complex analysis of these data. Optimization of using the electric energy generated by solar panels will enable to determine the maximum possible power in each specific moment and to automatically tune its consumption. The complex data obtained with this system can be further used for not only statistical fixation of the produced and consumed electric energy in fact but also for prediction of the energy amount that will be generated by these solar panels in future. The analysis of results will enable to optimize the area of solar panels and more exactly determine parameters of electronic components both for illumination systems and designing solar photoelectric stations of various purposes.

LED light sources, and powerful multichip light sources in particular, are currently widely used for lighting household and industrial premises. With an increase in power, the amount of heat increases as well, which leads to an increase in the temperature of semiconductor crystals and, accordingly, to a decrease in the reliability of LEDs and a change in their photometric characteristics. Therefore, when developing the design of LED lighting devices, special attention is paid to thermal management. Since the early 2000s, heat pipes have been widely used to efficiently remove heat from powerful electronic components. They do not require power for moving the working fluid and are most suitable for use in LED luminaires. In this study, the authors carry out a computer simulation of a cooling system based on heat pipes, which is then used to design and test a powerful compact LED lamp with a thermal load of up to 100 W. Heat pipes with a length of 150 mm are used to remove heat from the LED light source to the heat exchanger rings located concentrically around it. The heat exchanger rings are cooled by natural convection of the ambient air. The results of computer modeling of the temperature field of the developed cooling system show that at a power of the LED light source of 140.7 W, the temperature of the LED matrix case is 60.5°C, and the experimentally measured temperature is 61.3°C. The experimentally determined thermal power of the LED matrix is 91.5 W. The p–n junction temperature is 79.6°C. The total thermal resistance of the cooling system is 0.453°C/W. The obtained results indicate the effectiveness of the developed design.

Using LED technologies to create a comfortable light environment for human life and work can help reduce electricity consumption while maintaining, and usually improving, the energy and spectral parameters of lighting systems. At the same time, LED lighting systems for residential and industrial buildings are usually powered by electricity generated mainly by thermal power plants. Such plants mostly use fossil fuels and their combustion leads to environmental pollution. The article proposes the concept of a lighting system, which allows improving the ecology by reducing the energy consumption of lighting systems through the use of renewable energy sources. The proposed operation algorithm of the system for power supply control of LED light sources allows selecting the most appropriate energy sources in real time, thus making it possible to increase the luminous efficiency of the lamp by at least 20% when using industrial element base. This design can help to move away from traditional energy storage systems (batteries), which significantly increases the service life of such systems, their reliability and environmental safety. Placing photovoltaic converters in close proximity to the consumer (on the roofs and facades of buildings) ensures a decrease in ohmic losses and creates favorable conditions for using solar energy to light residential and industrial premises with LED lamps, which can significantly increase the economic and energy efficiency of such systems.

The problem of climate change poses a challenge for humanity: it is necessary to reduce harmful emissions into the atmosphere, caused mainly by the burning of coal in thermal power plants. Partially, this problem can be solved by the use of energy-saving devices and equipment, including the replacement of traditional light sources with more efficient LEDs. This, however, causes the problem of ensuring normal thermal modes of the LEDs, since the more powerfull the LED is, the more heat is released in their semiconductor crystals, which leads to an increase in the temperature of the crystals and a decrease in the reliability of the device. This problem becomes especially urgent when using powerful multi-chip LED light sources, the so-called SOB matrices, whose power even now exceeds 500 W. This article presents a new design of a powerful LED lamp for indoor illumination of rooms with low ceilings. The heat from the LED is transferred via heat pipes to the heat exchanger rings looped around the light source. The heat exchanger rings are cooled by the natural convection of the surrounding air (at an ambient air temperature of 20°C). Computer simulation allowed evaluating the ability of the proposed cooling system to provide a normal thermal mode of the LED light source. The results on the computer simulations of the temperature field of light source`s cooling system showed that when the LED power is 300 W, the temperature of the light source`s base at the point where it is connected to the light source does not exceed 67.6°C. When the contact zone is covered with a 0.1 mm layer of heat-conducting paste (Arctiс Silver 5 type) with a thermal conductivity coefficient of 8.7 W/(m•°C), the temperature of the LED case reaches 70°C. If the thermal resistance of the LED light source is 0.1°C/W, then the temperature of its semiconductor crystals will be 100°C, well below the allowable temperature value of 150°C. The total thermal resistance of the cooling system is 0.159°C/W.

A new method is proposed for the formation of MAPbBr3 nanoparticles in situ in a dispersion of polystyrene in toluene in the absence (MAPbBr3@PS) and presence of a broad-band luminophor (MAPbBr3/GAG:Ce@PS). This method permits the lossless use of perovskite, a uniform distribution of the luminophor nanoparticles in the polymer matrix, and maintenance of a high photoluminescence quantum yield (~46%). The samples derived from MAPbBr3 have green photoluminescence with a maximum showing a blue shift in going from bulk perovskite powder to films due to a size effect. The use of nanocomposite films MAPbBr3/GAG:Ce@PS in white LEDs permits enhancement of the color rendering index to 92 with correlation color temperature >5800 K.

—An integrated geological and geophysical study of wave-like accumulative bodies on the continental slope of the Caspian Sea was carried out to determine their origin. As a result, we revealed the regular change in geometry of layers and in the composition of sediments for different morphological elements of the waves. This pattern is manifested in their textural and structural features and is similar to the examples described in the literature for the regions, where the sediment waves are developed. The data we obtained allow us to interpret the studied accumulative formations as sediment waves.

For the first time, the Upper Pleistocene Girkanian sediment subhorizon was recorded in the submarine boreholes of the northern Caspian Sea and its radiocarbon age was estimated. Girkanian beds lying at a depth of 25 m beneath the seafloor were studied by lithological, biostratigraphical, seismic and radiocarbon dating methods. They were distinguished based on the characteristic assemblage of Mollusca (Didacna subcatillus, D. cristata, Corbicula fluminalis, etc.). This assemblage is similar to its onshore analogue and differs from the fauna of the underlying Upper Khazarian (D. surahanica, D. nalivkini, etc.) and overlying Lower Khvalynian (D. ebersini, D. parallella, D. protracta, etc.) layers. Acoustic profiling indicates the ubiquity of the horizon in the northern Caspian Sea, as seen from the clear correlation between boreholes. AMS 14C dating has shown that the age of the Girkanian deposits exceeds 55 ka. Their real age haze to be about 80 ka. The obtained results on identification and age estimation of Girkanian beds are an important contribution to the verification of the Upper Pleistocene stratigraphy of the Caspian Sea region.

This paper reports data on the Atelian horizon identified in the Caspian Sea bottom. Seismoacoustic profiling has made it possible to determine its area, position, and setting in the Upper Quaternary sequence and the relation to the host deposits. According to the drillhole core data, the Atelian horizon is composed of continental clay loam and sandy loam containing peatlike organic remains. They are depleted in biogenic residues containing rare freshwater mollusk species. The Atelian deposits were accumulated in lake reservoirs filling the depressions developed in the strata of the Upper Khazarian horizon. The radiocarbon age determined for the first time by humic acids has been used to estimate the Atelian deposition time in the range of 40 000–45 000 calibrated years BP.

The vibrational burnishing of holes is considered. In this technology, for which appropriate equipment is proposed, a solution of antifrictional mixture activated by ultrasound is supplied to the machining zone.

The distribution, sedimentology, and age of early Holocene Mangyshlakian deposits beneath the northern Caspian Sea are studied. Analyses and interpretations derive from high-resolution sub-bottom profiling, lithological analysis of core sections and boreholes, biostratigraphic analysis of mollusc shells, and radiocarbon dating. We show that the Mangyshlakian deposits overlie Upper Pleistocene Khvalynian deposits, filling valleys and depressions that formed during lower water levels, similar to present lacustrine water bodies (ilmeni) of the Volga Delta. Transgressive marine Holocene Neo-Caspian sediments that are filling facies overlie the Mangyshlakian deposits. The deposits are composed of both organogenous and terrigenous materials. The flora and fauna in the sediment indicate deposition into freshwater, differing from marine biota in the underlying and overlying sediments. Eighteen radiocarbon ages indicate that the Mangyshlakian deposits accumulated between 9 and 12 ka.

The authors propose fundamentally new design-technological solutions for compact volumetric mirrorized LED modules with increased power. Test samples of volumetric light-effective LED light effective modules with a power of 10—15 W and light output of 105—160 lm/W for domestic retrofit lamps based on high-efficiency SMD, mini COB, and COB LEDs of third generation were manufactured and tested. Positive technical and practical results were obtained by increasing by over 4—6 times the size of holders — heat sinks (compared to LED modules of flat holders) for heat dissipation from the LEDs by conduction and heat radiation, as well as by increasing light efficiency of LED lamps due to the additional light re-reflection by mirrorized reflectors-radiators in the bulb which is diffuser of the lamp light.

The structure of a device for the cutting and deformation of cylindrical shaft surfaces in jets of specially selected technological fluids is described and investigated.

Given article presents the results of an experimental comparison of three radiators which are: pressed radiator made of aluminum plate (basic variant), radiator made of copper wire, and copper/water pulsating heat pipe. The radiators are intended to take off heat from the LED module with the power capacity of 10,55 W. It is established that under natural convection all three radiators can keep temperature level of the circuit board module less than 64 C that lies within the operating range. In comparison with basic variant the use of the copper wire radiator allows lowering of the temperature in the LED module center on 3.9 C, and the same value for the pulsating heat pipe is 7.1 C.

It is shown that the electric field may cause instability of low-frequency potential oscillations with a period of about 1 min in the D region of the ionosphere. This is related to the fact that the attachment rate of electrons to molecules is a nonmonotonic function of the temperature: it increases at low temperatures and decreases at high temperatures. The temperature corresponding to the maximum attachment rate is about 1000 K. The development of instability can result in the formation of quasi-steady layers of the electron density with a characteristic spatial period of several tens of meters. Such inhomogeneities can affect the propagation of radio waves with wavelengths on the order of or shorter than 10 m.

Comprehensive analysis of the data of high-precision seismoacoustic profiling, drilling and sampling of deposits using seabed corers, biostratigraphic studies, and radiocarbon age data was performed for the first time for Mangyshlak sediments in several bottom sites of the North Caspian. It was found that the Mangyshlak sediments comprise numerous linearly stretched depressions of 5–10 m in depth (morphologically similar to modern substeppe ilmen areas in the Volga River delta), which are covered by the Novocaspian sedimentary cover, and river incisions (among them the largest Volga River valley). In addition, the Mangyshlak sediments comprise the deltaic alluvial fans of different sizes along the shelf zone of the North Caspian. Analysis of mollusks and biogenic remains indicates that accumulation of the Mangyshlak sediments occurred in freshwater and slightly salty water environments under various hydrodynamic and hydrochemical conditions. According to radiocarbon dating of organic matter, the Mangyshlak sediments formed during sea regression in the range of 10-8 ka (isotopic age) or 11.5-8.5 ka (calendar age). Several types of sediments are distinguished: clayey-carbonate sediments, enriched with organic matter up to the formation of sapropel and peat, accumulated at the lowest sea level; weakly calcareous silty-clayey silts, formed during the subsequent intense filling of paleodepressions with terrigenous material. The features of the mineral composition of sediments are as follows: polymineral composition of clayey material with a high proportion of hydromica and disordered mixed-layered formations, a high content of minerals of the epidote group, amphiboles, and other accessory minerals. All of this indicates a genetic relationship between the Mangyshlak sediments and the Volga terrigenous material.

Feasibility has been demonstrated for the use of the interpolymer complex of polyaniline with poly(2-acrylamide-2-methyl-1-propanesulfonic acid) (PAni·PAMPSA) and its nanocomposite with partially oxidized graphene (PAni·PAMPSA/POGr) as a material for hole transport layers in the manufacture of polymer light-emitting diodes (PLED). A study was carried out on the functional characteristics of such PLED, which were compared with those of traditional PLED made with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate anions (PEDOT/PSS). The PLED made with PAni·PAMPSA/POGr nanocomposites were shown to have better functional characteristics, namely, current density, brightness, current and luminous efficiency, than for the analogous heterostructures derived from the pure PAni·PAMPSA interpolymer complex. The PAni·PAMPSA/POGr nanocomposite may be used instead of PEDOT/PSS in the manufacture of efficient organic optoelectronic devices.

The dynamics of a circular film membrane with attached current-carrying conductors in zero gravity is studied. Equations are derived which describe the vibrations of the membrane stabilized by the Ampere force. The spectrum of natural vibrations and their corresponding strains are calculated. Constrained vibrations of the membrane are studied. The effect of the geomagnetic field on the stability of the membrane and the damping of its vibration is investigated for unsteady modes of application of mechanical forces in zero gravity.

We present a setup and procedure of studying p-n j unction-package thermal resistance in high-power light-emitting diodes (LED s) from their thermal relaxation. A set of LEDs mounted on a metal-core printed circuit board (MCPCB) were studied. The contributions to the total thermal resistance from a heavy heat sink, MCPCB, heat slug and LED chip are separated.

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.