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Participating in the circulation of nutrients, epilithic biofilms play an important role in water bodies. Denitrification actively proceeds in the epilithon of water bodies. However, information on the environmental factors that affect the process in biofilms is still limited. The object of study in this article involves the number of cultivated denitrifying bacteria in biofilms formed on the stony substrates in different parts of the Lake Baikal littoral zone. It has been found out that the main factors explaining the differences in the number of cultivated bacteria who perform complete denitrification were the temperature and the concentration of total nitrogen in shallow water. This article shows that a lower amount of denitrifiers is typical for biofilms experiencing nitrogen deficiency, as is indicated by the low stoichiometric N : P ratio in biofilms. An uneven distribution of heavy metals in the biomass of epilithic biofilms has been determined. It also may potentially impact denitrification in the epilithon of Lake Baikal. [ABSTRACT FROM AUTHOR]

Abstract—The paper reports mineral chemistry, whole-rock major and trace element composition, structure, and geological setting of the phlogopite peridotite lens within the Bug granulite–gneiss terrane of the Dniester–Bug Province, Ukrainian Shield. Geochemical features of the studied peridotites and minerals indicate a complex evolution of the lens. The early stage is marked by the crystallization of olivine + spinel (Al-chromite) cumulus from melt of supposably picritic composition, and further crystallization of clinopyroxene. The melt shows signs of hybridization by host gneissic enderbite. Orthopyroxene crystallized later and frequently replaces clinopyroxene. The phlogopite cystallization is likely related to the fluid activity and the growth of potassium potential in the fluid. Granulite-facies metamorphism accompanied by ductile deformations affected the mineral asseblage and chemical compositions of peridotites and orthopyroxenites. At the final stage, the rocks and minerals experienced retrograde metamorphism and local foliation of the rocks. [ABSTRACT FROM AUTHOR]

For the wire and arc additive manufacturing (WAAM) process, the results of studies of the geometry shaping of the deposited preform elements on 5086 aluminum alloy plates and developing a set of WAAM technology design procedures are presented. Studies during the surfacing of the first bead on the plate were carried out under the conditions of the established mode of non-pulse jet transfer at reverse polarity and various surfacing rates. Correlation interactions are studied, and mathematical dependences are obtained to describe the relationship between the process parameters and the bead geometry. It is shown that the geometric parameters will change along the length of the bead and, moreover, depending on the deposition rate, which must be taken into account when designing the WAAM process. For an element of the "cooling fin wall with variable height section" type in the manufacture of a preform, the correlation relationships of the geometry and process parameters were studied under the conditions of the actual layer-by-layer variable surfacing mode, the sensitivity of the output parameters to the process parameters was studied, the sensitivity coefficients were determined, and mathematical models were constructed for predicting and deviating the output parameters from the deviations of the input ones. The article shows and substantiates the compensatory nature of the effect of changing the magnitude of the current and speed on the geometric parameters of the beads, which can be used in the design and control of the WAAM process. For the main design tasks, a number of exploratory design procedures for WAAM are proposed that best organize the design process, as well as their formalized rules based on mathematical models. The rules for choosing the initial setting point for the process of direct supply of energy and material are considered, taking into account changes in the geometry of the beads along their length. [ABSTRACT FROM AUTHOR]

The results of studying present-day oil product concentrations in water of Baikal and its tributaries are given. The highest concentrations of oil products have been identified in the Southern Baikal. Seasonal and year-to-year dynamics of oil product concentrations in lake tributaries was determined. The level of water pollution by hydrocarbons was evaluated in accordance the sanitary-hygienic standards for water bodies used for fishery. The inflow of oil products from Baikal through the Angara River was calculated, and their approximate budget in the lake was compiled. [ABSTRACT FROM AUTHOR]

A study of the degradation profiles of drugs based on recombinant monoclonal antibodies under stress conditions made it possible to determine the dynamics and mechanisms of degradation processes, to identify drug degradation products, and to reveal differences in the stability of biosimilar drugs for relatively short times. A strategy for accelerated (35 d) stability assessment under stress conditions of the original product Soliris® (Switzerland) and its biosimilar PRK-001 (Russia) was proposed. Their degradation profiles after exposure to extreme pH, oxidative stress, and UV radiation were studied. Antibody fragments were analyzed using size-exclusion chromatography, capillary isoelectric focusing, electrophoresis, and mass spectrometry. Both products showed similar degradation profiles and similar changes in isoform contents. [ABSTRACT FROM AUTHOR]

We studied the regularities of distribution of siderophile elements, including platinum group elements (PGE), in rock and in sulfides from Archean (2814 ± 51 Ma) peridotites collected in a fragment of deformed dike within the Bug granulite complex, Ukrainian Shield. In comparison with the primitive mantle, the studied rocks are enriched in Rh, Pd, Ni, Fe, and Co, and are characterized by low concentrations of other PGE. Sulfides are represented by a high-temperature variety of pentlandite and a small amount of chalcopyrite, with an inhomogeneous PGE distribution in them. Pd/Ir ratio typical of superchondrite is revealed for rocks and some sulfides. It is supposed that enrichment in Pd was not resulted from fractionation, but was rather related to mantle metasomatism. Saturation of the melt with sulfides and liquation process were favored by contamination of harzburgite with the host gneissic enderbite and fractionation of olivine. Solid sulfide solutions formed from sulfide melts at temperatures close to the crystallization temperature of magnesium phlogopite from a silicate melt. [ABSTRACT FROM AUTHOR]

A series of silica mesoporous molecular sieves SBA-15 with a 7.7 ± 0.8 nm pore diameter, the surface of which is hydrophobized with methylsilyl groups, and polymethylsiloxane derivatives with a 1.6 ± 0.8 nm pore diameter were obtained. These sieves are characterized by X-ray phase analysis, adsorption of nitrogen at 77 K and water at 293 K, as well as IR spectroscopy. It is established that there is a significant resistance to water intrusion (absorption) only in the case of substances characterized by the nitrogen adsorption potential value ∆μ0 ≤ 6.4 kJ/mol. The studied systems can be used as "molecular springs" in shock load damping devices due to their functional properties. [ABSTRACT FROM AUTHOR]

In the work, (i) the danger of the contact between the fan impeller blades and the body of a gas turbine engine (GTE) is justified, (ii) the factors affecting the value of the radial clearance in flight are established, (iii) the main causes of contact are revealed, (iv) the modern tools for determining the radial clearance of GTEs are analyzed, and (v) the in-flight method for identifying the contact between the fan blades and the body of a GTE is proposed based on the complex processing of vibration signal of the fan body and pressure sensor signals behind the fan. Introduction of the identification method based on processing the vibration and pressure pulsation signals improves the flight safety, especially for prototype GTEs at first stages of flight tests without the need for additional preparation and mounting of complex clearance control systems. This method may be applied for identifying the contact at excessive decrease in the radial clearance, which allows in-time decision making about relieving the flight mode (if it is possible at the flight stage when the contact occurs) in order to avoid substantial damage caused by contacts. [ABSTRACT FROM AUTHOR]

The comprehensive study (electron microscopy, mass-spectrometry of secondary ions, Raman spectroscopy) of zircon from harzburgite inclusion in granulites of the Bug complex (Ukrainian Shield) is carried out. Based on a number of features, the studied zircons are subdivided into three groups. Zircon from the first group is of igneous genesis and crystallized 2.8 Ga ago at the temperature of about 650°C from a melt of orthopyroxenite composition. Zircon from the second group underwent hydrothermal alteration ca. 2.75 Ga ago at the temperature of about 750°C. Zircon from the third group is distinctive in several geochemical characteristics (higher Lu/Hf ratio, etc.) and formed before the hydrothermal process, but their compositions were altered by the fluid. Conditions of the igneous zircon (first group) crystallization were characterized by the higher value, compared to the later hydrothermal alteration. The hydrothermal process has provided the distortion of zircon crystal lattice, which is reflected in the Raman spectra, and the formation of amorphous structure in the uranium-rich zircon from the third group. In terms of trace element contents, the first and second zircon groups indicate different initial melts (from which they originated) from the third zircon group; the melt of the third group was more mafic. The obtained results support the idea about the hybrid character of the melt and that the rock formed in two main stages, namely, a magmatic one and fluid alteration, separated in time and having different oxidation-reduction conditions. [ABSTRACT FROM AUTHOR]

The objective of the present study was to assess the levels of Se, as well as other essential and toxic trace elements in wheat grains and traditional Roti-bread from whole-grain flour in a seleniferous area of Punjab (India) using inductively-coupled plasma mass-spectrometry. Wheat grain and bread selenium levels originating from seleniferous areas exceeded the control values by a factor of more than 488 and 179, respectively. Se-rich wheat was also characterized by significantly increased Cu and Mn levels. Se-rich bread also contained significantly higher levels of Cr, Cu, I, Mn, and V. The level of Li and Sr was reduced in both Se-enriched wheat and bread samples. Roti bread from Se-enriched wheat was also characterized by elevated Al, Cd, and Ni, as well as reduced As and Hg content as compared to the respective control values. Se intake with Se-rich bread was estimated as more than 13,600% of RDA. Daily intake of Mn with both Se-unfortified and Se-fortified bread was 133% and 190% of RDA. Therefore, Se-rich bread from wheat cultivated on a seleniferous area of Punjab (India) may be considered as a potent source of selenium, although Se status should be monitored throughout dietary intervention. [ABSTRACT FROM AUTHOR]

The results of long-term routine measurements of the concentration of major ions in the water of the Lake Baikal pelagic zone, the Angara River source, and main tributaries of the lake are analyzed. The average values of ion concentration in the water column of the lake and in the Angara River obtained for the recent decade are presented and compared with the data of previous studies. Long-term trends in the concentration of ions in the main Baikal tributaries are shown. Under low-water conditions, the inflow of ions to Lake Baikal through tributaries decreases despite an increase in their concentration in river water. Changes in the chemical composition of water in the tributaries did not affect the ionic composition of water in the Lake Baikal pelagic zone and in the Angara River source. [ABSTRACT FROM AUTHOR]

This article presents the results of comparative studies of the frequency and distribution of chiasmata in pollen mother cells (PMCs) in five diploid tomato species, Solanum lycopersicum, S. pimpinellifolium, S. peruvianum, S. habrochaites, and S. neorickii, and one autotetraploid species, S. pimpinellifolium. It was established that under the same growing conditions, the total chiasma frequency in the cell depended on the species. At the same time, the green-fruited species S. peruvianum, S. neorickii, and S. habrochaites differed in distal chiasma frequency, while the red-fruited species S. lycopersicum and S. pimpinellifolium differed in interstitial chiasma frequency. It was shown that the total chiasma frequency in PMCs of plants of one species is a stable index of recombination potential that does not depend on the growing conditions. The redistribution between distal and interstitial chiasmata was found to be more variable, depending on the species, year, geographic growth conditions. In autotetraploid, the chiasma frequency per bivalent was lower than that in diploid S. pimpinellifolium plants, primarily due to interstitial chiasmata, the frequency of which remained at the level characteristic for diploid plants. It was concluded that the recombination plasticity of the tomato genomes was due to the redistribution of chiasmata along bivalents, and not to the change in their number in the cell. [ABSTRACT FROM AUTHOR]

In interspecific hybrids a decrease in genetic exchanges between chromosomes from different species and negative interactions between functionally incompatible loci limit genetic variation among the progeny. Earlier the fraction of crossover genotypes was increased in intraspecific hybrids of the cultivated tomato Solanum lycopersicum with the expression of the recA Escherichia coli gene. In this research transgenic hybrids between S. lycopersicum and some wild tomato species were obtained in order to study the effect of recA gene expression on the frequency of crossovers in the progeny of interspecific hybrids. Interspecific hybrids showed negative interactions between the loci of the cultivated tomato and the S. cheesmaniae, S. pimpinellifolium, and S. habrochaites species. In the latter case it resulted in semilethal necrosis. The recA gene expression in interspecific hybrids with S. cheesmaniae partially compensates among the F2 progeny the deficiency of recessive genotypes at the Wv:wv locus of chromosome 2. In general, the fractions of crossover genotypes in the F2 progeny were higher in transgenic interspecific hybrids than in control non-transgenic hybrids of the same combination of crossing, but lower than in intraspecific S. lycopersicum hybrids. [ABSTRACT FROM AUTHOR]

The Sr isotope characteristic of carbonate rocks in the Central Azov Group has been reported (0.70322–0.70352), the Nd model age of silicate sediments has been calculated (2.34–2.31 Ga), and the U–Pb age of trondhjemites (2052 ± 5 Ma) breaking through carbonates was determined. According to the data obtained, the marine sedimentary cover of the Azov block making up the Early Precambrian Sarmatia Continent was formed in the Early Paleoproterozoic 2.23–2.34 Ga ago. [ABSTRACT FROM AUTHOR]

Data on the U–Pb (SIMS SHRIMP-II) age (3628 ± 38 and 2845 ± 65 Ma) of zircon from the inclusion of mafic granulite in gneiss–enderbites of the Bug complex in Ukraine are obtained. A zircon age of 3628 ± 38 Ma for the first time has allowed us to identify the occurrence of basic magmatism at the Paleo- and Eoarchean boundary in the Bug region. The age of 2845 ± 65 Ma dates the imposed metamorphism manifested everywhere in the Bug region that led to considerable amphibolization and partial melting of the rock. [ABSTRACT FROM AUTHOR]

In cultivated tomato hybrids (Marglobe × Mo938), the anthocyanin-free gene shows linked inheritance with the d (dwarf) gene on chromosome 2, but with a recombination frequency approximately three times higher than that according to the genetic map and in other hybrids with the Marglobe line. Cytological analysis of the mother pollen cells of the hybrids (Marglobe × Mo938) revealed no abnormalities of meiotic division and segregation of chromosomes, as well as no decrease in fertility. By means of the functional allelism test, it was established that, unlike Mo500, Mo504, and Mo755 marker tomato lines, in Mo938 the anthocyanin-free trait is not determined by the aw (anthocyanin without) or aa (anthocyanin absent) genes of chromosome 2. Using the F2 progeny of interspecies hybrids (Mo938 × Solanum pimpinellifolium), independent inheritance of the anthocyanin-free gene relative to the wv (white virescent) and d marker genes, as well as to six SSR anchor markers distributed at different sites of chromosome 2, was established. Thus, the Mo938 tomato line carries the d and wv markers on chromosome 2, as well as the anthocyanin-free gene not belonging to chromosome 2. [ABSTRACT FROM AUTHOR]

Experience in reconstructing the PT-60-90 turbine at Salavatskaya CHPP upon the operation for more than 350000 h is described. In the course of reconstruction, the life of the turbine was restored, its economic efficiency was increased, process extraction of 1.27-1.57 MPa was changed to uncontrolled extraction, and additional extraction of 3.43 MPa was arranged. The high-pressure cylinder (HPC) shell was restored by reconditioning heat treatment (RHT), and the rotor was replaced by a new modernized one. To select the optimal conditions of the reconditioning heat treatment of the HPC shell (of the PT-60-90 turbine) manufactured from 20CrMoPL grade steel, the results of previously conducted tests of the shell metal of the same grade were integrated. The heat treatment was carried out on modernized furnace equipment using means of and methods for controlling the temperature and heating and cooling rates. Detailed nondestructive inspection of the upper and lower HPC halves was performed. The locations, distribution, sizes, and types of the defects were identified. The detected defects and austenitic build-ups were removed, welded with pearlite electrodes, examined, and subjected to heat treatment (tempering). The actual heat treatment conditions were analyzed and, based on the obtained data on the mechanical properties of the metal, the tempering temperature and time were specified. Complete investigation of the metal of both HPC halves was conducted prior to the reconditioning heat treatment. The reliability of the metal of the cylinder shell after RHT was evaluated by the mechanical properties, such as tensile strength, critical ductile-to-brittle transition temperature (crack resistance), and stress-rupture strength. It was established that, after RHT, the characteristics of the metal, such as yield strength, ultimate strength, elongation per unit length, contraction ratio, hardness, and impact toughness, significantly improved and, on the whole, the quality of the metal met the requirements of the normative documentation for newly manufactured castings. The heat resistance of the metal of the cylinder shell after RHT also increased, which can ensure the operation of the HPC shell for more than 200 000 h provided that the recommendations for regular inspections of its condition are followed. [ABSTRACT FROM AUTHOR]

This paper presents the results of a complex study (morphology of grains, internal texture in cathodoluminescence and backscattered electrons, microprobe analysis, Lu-Hf data) of five groups (generations) of zircon crystals differing in age and separated from the same granulite sample pertaining to the Bug River Complex of the Ukrainian Shield. The data show that the oldest zircon crystals of the first group (3.74 Ga in age) are xenogenic and initially crystallized from a granitic melt; zircon of the second group (3.66 Ga) formed from a mafic melt contaminated by felsic country rocks. The third group (3.59 Ga) is represented by zircons that formed about 100 Ma later than the second group under conditions of granulite-facies metamorphism and with the participation of fluid-saturated anatectic melt. Two Paleoproterozoic zircon groups (~2.5 and 2.1 Ga) also formed under granulite-facies conditions; to a certain extent, their structure and composition were controlled by fluid. The geochemistry of all zircon generations provides evidence for their crystallization in the continental crust, but from the sources differing in the contribution of mantle-derived material and in oxygen fugacity. [ABSTRACT FROM AUTHOR]

Complex study of the U-Pb and Lu-Hf systems of zircon from a lhertzolite lens of Archean gneiss enderbites of the Bug complex, Ukrainian Shield, showed that ultramafic magma was contaminated by the material of the country gneiss enderbites. The age of the zircons of 2.81 ± 0.05 Ga corresponds to the period of ultramafic magmatism within the Bug complex. Previously, this peak of endogenic activity was considered the stage of manifestation of metamorphism and magmatism of mafic composition. [ABSTRACT FROM AUTHOR]

This report presents data on the geological structure and location of the orthopyroxenite inclusion in gneissic enderbites of the Bug granulite-gneiss domain. Three stages of orthopyroxenite formation were identified on the basis of studies of the mineral composition along with the U-Pb and Lu-Hf isotope systems of zircons. [ABSTRACT FROM AUTHOR]

Field observations showed that the characteristics of chemical composition of waters and the development of plankton algae in the lakes within the delta of the Selenga river are determined by their flowage. The most open Lake Nekipelovskoe communicates with the Selenga outlets throughout a year, and Lake Zavernyaikha only at the period of an open channel. Lake Semenovskoe and Lake Khlystov Zaton are located in the islands and are isolated from the outlets. According to composition of main ions, the lakes under investigation refer to the hydrocarbonate class, the calcium group. The sum of ions in the water of Lake Nekipelovskoe approaches the one in the Selenga (86−221 mg/dm), and the highest sums of ions were recorded in the wintertime in the lakes isolated from the outlets (446−743 mg/dm). The lakes of the delta are characterized by a high trophicity. The maximum concentrations of total phosphorus in Lake Nekipelovskoe and Lake Zavernyaikha were 68 and 122 μg mg/dm, and in Lake Semenovskoe and Lake Khlystov Zaton −0.8 and −0.63 μg mg/dm, respectively. The most intense development of algae is observed in Lake Zavernyaikha, which is due to the high population of Baikal endemics. Lake Zavernyaikha showed a close negative correlation between the concentration of NO, mineral phosphorus and phytoplankton biomass; the correlation coefficient was −0.8 and −0.63, respectively. The lakes exhibited increased contents readily hydrolysable organic matter, and a decrease in dissolved oxygen concentration in winter; hydrogen sulfide was repeatedly recorded in Lake Khlystov Zaton. The water quality in the lakes during the springtime varies from 'quite clean' to 'weakly polluted'; at low-water periods, especially in winters, it can drop to the category of 'exceedingly dirty'. The water quality of the Selenga can be influenced by the lakes during spring floods when material accumulated during the wintertime is transported to the river outlets and further to Lake Baikal. [ABSTRACT FROM AUTHOR]

The sources of polycyclic aromatic hydrocarbons (PAHs) and sources of water that deliver PAHs to an investigated river were apportioned using an end-member mixing approach. The identification of sources and tracers was based on bounding the samples by end-member sources on the mixing diagram using coordinates of source tracer concentrations. The sums of PAHs with the same molecular weight were used as PAH source tracers, and the dissolved organic carbon to base cations ratio was used as a tracer for water sources. The source contributions were evaluated by solving systems of linear equations. Most of the water samples were bound by a triangle formed by wood combustion, oil-fired boilers, and aluminum smelters in the mixing space defined by the concentrations of the principal mass 178 and 228 PAHs. There were notable seasonal variations in the PAH source contributions at each sampling site due to different contributions of groundwater, surface flow, and interflow to stream water. The differences in the PAH source contributions among sites were due to both different proportions of the flow components and different positions of the sites relative to the emission sources. Most of the bottom sediment samples were bound by a triangle formed by the same sources, but in the mixing space defined by the principal mass 252 and 276 PAHs. There were no spatial or temporal differences in the PAH source proportions among the samples because the PAH composition of the bottom sediments at each location represents the time- and space-weighted average of all the sediment loads from upstream. [ABSTRACT FROM AUTHOR]

The recombinant E7 oncoprotein gene of type 16 human papilloma virus (conjugated with the heat shock protein 70 (E7(16)-HSP70)) was expressed in Saccharomyces cerevisiae yeast cells. A number of chromatographic isolations were conducted to obtain the target protein and its primary identification and to establish its originality. The use of metal chelate chromatography was based on selective binding of sorbent active groups with a poly-histidine fragment at C-terminus of the target protein polypeptide sequence, while the use of affine chromatography was based on the association with ATP-binding regions of E7 and HSP70. The degree of purity of the target protein after both procedures did not exceed 70%, indicating the presence of many low-molecular admixtures and products of the target molecule oligomerization. The use of chromatographic purification under denaturing conditions using strong reducing agents allowed isolation of the target protein, the monomer content in which exceeded 97%. The target protein originality was established by immunoblotting and electrophoresis; the correspondence of its primary structure to the declared sequence was demonstrated by mass-spectrophotometry. [ABSTRACT FROM AUTHOR]

We performed a joint analysis of SHRIMP II U-Pb ages (68 measurements for 5 rock types) and trace and rare-earth element compositions of zircons (41 determinations made in the same points that were utilized for measurement of U-Pb isotope ratios) from the complex Orekhovo-Pavlograd shear zone of the Ukrainian Shield. It was determined that this zone is composed of rocks of different age: 3.5, 3.4, 2.8, and 2.0 Ga. The main stage of structural-metamorphic reworking took place 2.0 Ga and lasted for over 30 Ma. It was established that fluid reworking of zircons was accompanied by an increase of LREE content and decrease of Ce anomaly. The preservation of U-Pb system in some zircons with high LREE contents may be explained by their solid state transformation. [ABSTRACT FROM AUTHOR]

The available geological, petrological, and isotopic data on Archean rocks of the Baltic shield are used to analyze the formation of the crust of the ancient Vodlozero domain. This made it possible to reveal the succession of endogenic processes in different parts of the domain and correlate them between each other. Several stages of magmatic processes reflecting changes in magma-generation environments are definable in the crust formation. The earliest stages of magmatism (3.24 and 3.13-3.15 Ga) are mostly represented by rocks of the tonalite-trondhjemite-granodiorite association. The next stage of endogenic activity (3020-2900 Ma) was marked by the formation of volcanics of the komatiite-basalt and andesite-dacite associations constituting greenstone belts in marginal parts of the Vodlozero domain and basic dikes accompanied by layered pyroxenite-norite-diorite intrusion in its central part. These basic bodies crossing earlier tonalities were formed in extension settings related to the formation of the mantle plume, which is confirmed by the rock composition. This stage culminated in the formation of trondhjemites at margins of greenstone structure. The next stage of endogenic activity commenced at 2890-2840 Ma by the emplacement of high-magnesian gabbro and diorite dikes in the western margin of the domain, where they cross rocks of the tonalitetrondhjemite association. This stage was marked by the formation of intermediate-acid subvolcanic bodies and dikes as well as basite intrusions including the layered and differentiated Semch intrusion, the largest one in the Vodlozero domain. The stage culminated at approximately 2850 Ma in the emplacement of tonalities of the limited distribution being represented by the Shilos massif in the north of the domain and Shal'skii massif on the eastern shore of Lake Onega. The important stage in the geological history of the Vodlozero domain is the formation of the intracratonic Matkalakhta greenstone belt at approximately 2.8 Ga, which includes arenite quartzite and graywackes and polymictic conglomerates developed in the Lake Oster area in addition to volcanics. These rocks indicate a stable tectonic regime, which resulted in deep erosion of the crust. The emplacement of sanukitoids (2.73-2.74 Ga) as well as subsequent two-feldspar granites (2.68-2.70 Ga) and basite dikes (2.61-2.65 Ga) may be considered as resulting from the plume influence on the relatively stabilized sialic crust of the Baltic shield. [ABSTRACT FROM AUTHOR]

Paleoarchean granulite-facies metasedimentary rocks (quartzites, garnet quartzites, garnet-pyroxene gneisses, pyroxene-magnetite and magnetite quartzites) attributed to the Dniester-Bug Group of the Ukrainian Shield were studied. On the basis of geochemical data, including REE, the primary composition of these rocks was reconstructed as association of Fe-rich sandstones and sublitharenites, Fe-shales, and BIFs. This sedimentary association is similar to the rocks of other ancient greenstone belts and ascribed to the Algama-type iron formation. The sum of AlO, CaO, NaO, and TiO, high Zr contents (>100 ppm in quartzites), and the presence of detrital zircon grains of different ages are consistent with the terrigenous nature of sedimentary rocks. The Sm/Nd, Ti/Zr, Sc/Zr, and Ni/Zr ratios indicate the predominance of granitoid rocks in the source areas. The elevated Cr contents suggest that, in addition to granitoids, the source area contained ultramafic rocks. Geochemical characteristics, such as Fe/Mn ratio, low REE contents, and variations of REE versus the sum of Ni, Co, and Cu testify that sedimentation occurred under shallow-water conditions on the continent or its slope, similarly as the formation of ancient (3.5-3.2 Ga) basalt-komatiitic series intercalated with sedimentary rocks in the Pilbara Craton. The age of supracrustal rocks of the Dniester-Bug Group was constrained within the time interval of 3.4-3.2 Ga on the basis of U-Pb zircon dating and determination of Nd isotope composition. The DM model age of quartzites varies from 3.37 to 3.5 Ga. Sedimentary rocks together with volcanic rocks represent the oldest supracrustal association of the East European Platform. [ABSTRACT FROM AUTHOR]

The article discusses the study conducted on granulite gneiss areas (GGA) and granite greenstone areas (GGSA) as important tectonic elements of the Archean time period to examine the reasons for the early evolution of the Earth. Topics discussed include Pobuzhie granulite complex (PGC) composed in the southwestern part of the Ukraine, information about Granulite UR132 as a glassy and gneissose rock with poor foliation and microbanding, and obtaining age of zircons during recrystallization.

The article discusses a study published in the journal "Doklady Akademii Nauk" in 2013 to investigate new data on the age of archean rocks from the Vodlozero domain of the Karelian Craton area. It informs that the Vodlozero domain is a fragment of the Baltic Shield with Mesoarchean crust. The intrusive origin of tonalities is evident from the presence of xenoliths.

The SIMS U-Pb isotopic age of zircons from enderbite gneisses and their metaorthopyroxenite xenoliths in the Pobuzhie granulite complex, Ukrainian Shield (48°13′57.3″ N and 29°59′21.5″ E, WGS84 system), was determined. The chemical compositions of these rocks and composing minerals were studied. Enderbite gneisses contain quartz, antiperthite plagioclase, K-feldspar, clinoenstatite, diopside, amphibole, and a small amount of biotite; accessory minerals are ilmenite and apatite. The age of zircon from enderbite gneiss is estimated at about 3.15 Ga. Metaorthopyroxenites are composed of orthopyroxene, clinopyroxene, phlogopite (up to 6% TiO), and plagioclase. The age of magmatic zircons from metaorthopyroxenite determined by the upper intercept of the discordia with the concordia is 3485 ± 33 Ma (MSVD = 1.6), and the age of metamorphic zircons is 2742 ± 22 Ma (MSVD = 0.22). Hence, the enderbite gneisses studied pertain to a young group of enderbites in the Pobuzhie granulite complex, while the age of metaorthopyroxenites from xenoliths in these rocks is similar to that of ancient Pobuzhie enderbites and pyroxenites of the Novopavlovsk complex in the Azov Region. [ABSTRACT FROM AUTHOR]

To study and induce meiotic recombination in plants, we generated and analyzed transgenic tomato hybrids F-RecA and F-NLS-recA-LicBM3 expressing, respectively, the recA gene of Escherichia coli and the NLS-recA-licBM3 gene. It was found that the recA and NLS-recA-licBM3 genes are inherited through the maternal and paternal lineages, they have no selective influence on the pollen and are contained in tomato F-RecA and F-NLS-RecA-LicBM3 hybrids outside the second chromosome in the hemizygous state. The comparative analysis of the meiotic recombination frequency (rf) in the progenies of the transgenic and nontransgenic hybrids showed that only the expression of the recA gene of E. coli in cells of the F1-RecA plants produced a 1.2-1.5-fold increase in the frequency of recombination between some linked marker genes of the second chromosome of tomato. [ABSTRACT FROM AUTHOR]

Homologous DNA recombination in eukaryotes is necessary to maintain genome stability and integrity and for correct chromosome segregation and formation of new haplotypes in meiosis. At the same time, genetic determination and nonrandomness of meiotic recombination restrict the introgression of genes and generation of unique genotypes. As one of the approaches to study and induce meiotic recombination in plants, it is recommended to use the recA gene of Escherichia coli. It is shown that the recA and NLS-recAlicBM3 genes have maternal inheritance and are expressed in the progeny of transgenic tomato plants. Plants expressing recA or NLS-recA-licBM3 and containing one T-DNA insertion do not differ in pollen fertility from original nontransgenic forms and can therefore be used for comparative studies of the effect of bacterial recombinases on meiotic recombination between linked genes. [ABSTRACT FROM AUTHOR]

The novel detailed geological and geochronological data for the tonalitie rocks and products of its structural and metamorphic overprint in the Orekhovo-Pavlogradskaya collision zone (Ukrainian Shield) are discussed. Magmatic crystallization of tonalites (3500 ± 13 Ma) followed by amphibolite (2863 ± 22 Ma) and granulite (2105 ± 40 Ma) facies metamorphic events, resulting in biotite-garnet gneisses formation. The last date also indicating the time of collision event. The earliest age of 3.64 Ga was found in the zonal zircon fragment within 3.5-Ga old magmatic zircon from tonalite. [ABSTRACT FROM AUTHOR]

The geological setting, geochemistry, and Nd isotopic systematics of tonalite-trondhjemite-granodiortite (TTG) series in ancient cratons are considered. It is shown that the TTG series were formed from ∼4.2 to 2.6 Ga ago in the oldest continental cores; many TTG series do not reveal chronological links to greenstone belts. This follows from the evolution of the Slave Craton in the Canadian Shield, the Vodlozero Craton in the Baltic Shield, and the Pilbara and Yilgarn cratons in the Australian Shield, where greenstone associations postdated TTG series. As has been established at the Baltic Shield, the primary melts of the Mesoarchean TTG associations were formed at a shallower depth ( P < 15 kbar) compared to the Neoarchean TTG, likely, due to the increasing thickness of the continental crust beneath the Baltic Shield over time. The Nd isotopic composition of worldwide TTG associations indicates that most of them are characterized by a substantial time interval (>150 Ma) that separates the formation of the TTG melts from the age of the source involved in melting. Taking into account the calculated rate of cooling of the lithospheric plates, these data indicate that most Archean TTG series likely were not formed in the convergent subduction-related and accretionary geodynamic settings. The isotopic and geochemical data constrain compositions of the sources that produced Archean TTG series. Petrologic modeling of the formation conditions and Nd isotopic composition of the metabasalts in greenstone belts show that these rocks could not have been the source of TTG series. The most plausible isotopic and geochemical analogue of this source are the Archean amphibolites (ENd mafic rocks), which differ from the metabasalts of greenstone belts by their lower Sm/Nd ratio and enrichment in some lithophile elements. The available data suggest that the primary TTG melts were generated as products of melting of amphibolites and granulites forming the lower crust. [ABSTRACT FROM AUTHOR]

Multilayer In0.4Ga0.6As/GaAs quantum dot (QD) chain samples are investigated by means of cw and time-resolved photoluminescence (PL) spectroscopy in order to study the peculiarities of interdot coupling in such nanostructures. The temperature dependence of the PL has revealed details of the confinement. Non-thermal carrier distribution through in-chain, interdot wave function coupling is found. The peculiar dependences of the PL decay time on the excitation and detection energies are ascribed to the electronic interdot coupling and the long-range coupling through the radiation field. It is shown that the dependence of the PL decay time on the excitation wavelength is a result of the superradiance effect. [ABSTRACT FROM AUTHOR]

This work considers geochemical and isotopic characteristics of the source of the Archean Panozero pluton derived from LILEand LREE-enriched lithospheric mantle. Sr and Nd isotopic data on clinopyroxenes and augites define a source with Sri = 0.7017 and ɛNd(t) varying within a narrow range from + 0.7 to + 1.4 (averaging + 1.1), which is close to previously obtained whole-rock isotopic data. Similar ɛNd(t) were obtained for the Archean alkaline rocks of Canada, whereas the Archean mafic rocks of the Baltic and Canadian Shields formed from depleted mantle have ɛNd(t) ∼2. Lead isotope measurements on K-feldspars ( KFsp) and monzonite showed that the source of the pluton has μ = 8.98 for the Stacey-Kramers two-stage model, at low U/Pb and high Th/U ratios. Different lead isotope composition corresponding to μ = 10.43 was determined in KFsp from quartz monzonites. Diverse interpretations of obtained data have been proposed. It was noted that the Pb-Pb isotopic system was disturbed by a later (∼ 1.9 Ga) thermal event. The ratios of elements of similar compatibility were used to determine the geochemical specifics of source of the Panozero pluton. Their comparison with numerous literature data on metasomatized mantle xenoliths and minerals in them showed that the mantle source strongly differed from primitive mantle in ratios of elements, whose mineralmelt partitioning coefficients considerably differs from mineral-fluid partitioning, for instance, Nb/La. Mantle source that was responsible for geochemical peculiarities of the Panozero pluton was made up of Phl, CPx, and Ap. [ABSTRACT FROM AUTHOR]

Ion microprobe study of rare-earth and trace element composition of zircons from miaskite lamproites of the Panozero sanukitoid complex in Central Karelia made it possible to divide them into weakly altered and metasomatically altered zircons. The latter differ in elevated contents of LREE, Ca, Al, Fe, Ti, Sr, Ba, and Th, a flat REE distribution pattern, and a reduced Ce anomaly. Zircons show moderate to strong degrees of alteration, which are recorded in their geochemical features. The metasomatic alteration was caused by fluid related to the mantle alkaline magmatism. At the final stage, this fluid caused the crystallization of zircon domain with extremely high contents of REE (55000 ppm), Ti, Ba, Sr, and Th. The use of a Ti thermometer for unaltered zircons from the miaskite lamproites yields strongly underestimated temperatures, which require additional explanation or revision of the thermometer. For strongly altered zircons with sharply elevated Ti content, the use of this thermometer seems to be impossible. [ABSTRACT FROM AUTHOR]

A new K-330-23.5 steam turbine is presented. It is intended both for newly constructed power engineering installations and for replacing K-300-240 turbines that have exhausted their lifetimes. It is shown that this turbine can be used when reconstructing Kharkiv Turbogenerator Works K-300-240 turbines with installation of a new unit on the existing foundation. [ABSTRACT FROM AUTHOR]

A microwave digestion procedure with the use of specially designed autoclaves and a domestic microwave oven is proposed for the mass-spectrometric determination of the elemental composition of bottom sediments. The throughput of sample preparation in routine analysis was considerably increased because of the elimination of a purification step. Reaction mixture compositions and microwave digestion conditions were chosen to reach complete decomposition (within the limits of error of semiquantitative ICP MS analysis) of Baikal bottom sediments with respect to the majority of elements. It was found that the procedure is unsuitable for the determination of Sn, Zr, Nb, Hf, As, and Sb. The approximate concentrations of elements in a BIL-1 certified reference material of Baikal bottom sediments were found: Tl, 0.52 ± 0.16 ppm; Bi, 0.33 ± 0.10 ppm; I, 14.3 ± 4.3 ppm; Cd, 0.31 ± 0.09 ppm; and Pb, 0.24 ± 0.07 ppm. [ABSTRACT FROM AUTHOR]

The structure and composition of accessory zircons from the tonalites of the Vyg River, southeastern Karelia, were investigated. Their local U-Pb SHRIMP dating yielded ages between 3127±15 and 3146±25 Ma. It was shown that the zircons consist of three zones, a central part containing solid and melt inclusions and zoned magmatic and metasomatic shells. The obtained ages correspond to the magmatic and metasomatic stages of zircon crystallization. In general, the zircons have elevated contents of LREE (up to 867 ppm La), which were mainly accumulated in the outer metasomatic shell. Apatite and CO2 inclusions are widespread. Orthoclase, orthopyroxene, ilmenite, galena, quartz, and bastnaesite were identified in a solid inclusion in one zircon core using a CAMSCAN MX 2500 electron microscope. The presence of bastnaesite accentuates the relation of LREE with a CO2-rich fluid. It was shown that REE content is not correlated with U, Th, and U/Th ratio. [ABSTRACT FROM AUTHOR]

Geochemical, isotopic-geochemical, and geochronological information was obtained on magmatic rocks from the Saltychan anticlinorium in the Azov domain of the Ukrainian Shield. The rocks affiliate with the calc-alkaline series and a high-Mg series. The rocks of these series notably differ in concentrations of trace elements and REE and range from gabbro to granodiorite-quartz diorite in composition. The NORDSIM ionprobe U-Pb zircons ages of rocks belonging to the Obitochnen Complex and having both elevated and normal mg# correspond to 2908–2940 Ma. The Osipenkovskaya intrusion has an age of 2855 ± 19 Ma. The most alkaline North Obitochnen intrusion was emplaced in the Proterozoic, at 2074 ± 11 Ma. The age of the amphibolite metamorphism of the host gneisses is reliably dated at 3120–3000 Ma. The model Sm-Nd ages of the intrusive rocks do not exceed 3150 Ma. According to geochemical evidence, the parental melts of the magmatic rocks were derived from mantle domains variably enriched in lithophile elements. The results obtained by studying the Sm-Nd isotopic system corroborate the conclusion drawn from geochemical evidence that most of the melts were derived from the mildly enriched mantle, practically without involvement of ancient crustal material. The mantle became enriched in LREE at approximately 3000 Ma, which corresponds to the age of metamorphism of the supracrustal rocks. This process was separated from the derivation of the melts by a time span of 70–80 Ma. The relative age of the intrusive rocks and their variable composition can be most adequately explained by a contribution of heat and material from a plume to the derivation of the parental melts of these rocks. [ABSTRACT FROM AUTHOR]

The high-K and high-Mg Panozero central-type intrusion is located on the shore of Lake Segozero, Central Karelia, and has an age of 2737 ± 10 Ma. Detailed mapping and petrological study showed that it was formed in three magmatic cycles that were separated by lamprophyre dikes. The first cycle is composed mainly of mafic rocks (layered complex: pyroxenites-honblendites-monzogabbro) and monzonites 1; the second cycle includes monzonites 2, and the third cycle comprises monzonites 3 and quartz monzonites. The massif is cut by numerous lamprophyre dikes and breccia zones. As compared to calc-alkaline series, the studied rocks are enriched in K, Ba, Sr, P, LREE, have high mg# (mg# = 0.5–0.65), and elevated contents of Cr and Ni. The parent composition of the layered complex was determined to be monzogabbro. Model calculations showed that the compositional variations of the Panozero Complex are consistent with the fractional crystallization of monzogabbro. The melts were fractionated in an intermediate chamber and during the flowing and crystallization of the magma. The parent melt of the intrusion was formed by the partial melting of mantle enriched in some LILE, LREE, and volatiles (CO2 and H2O). The volatile enrichment of the melt manifests itself in the mineral composition of the rocks, the presence of primary gas inclusions in apatite, and diverse structural features. The comparison of the rocks of the Panozero Massif with metasomatized mantle xenoliths in the variation diagrams for incompatible elements showed that the mantle source of the Panozero Complex was metasomatized by fluid consisting of H2O and CO2 of different origin. [ABSTRACT FROM AUTHOR]

The technologies of strengthening articles of the steam-turbine flow path (working blades, disks, and shafts) that are developed and introduced into practice are considered. These technologies are aimed at increasing reliability and wear resistance. Information is presented on fretting technology for disks and attachment roots of working blades using rolling-out methods, pneumatic shot-blasting strengthening, and diamond smoothing, as well as regarding protective-coating deposition and electric-spark alloying technologies for working parts of the blades. The results from studies conducted at the stage of mastering these technologies and their introduction into practice are given. [ABSTRACT FROM AUTHOR]

Two versions of reconstructing a T-100-12.8 turbine with the use of advance technical decisions and modern methods of design are presented. [ABSTRACT FROM AUTHOR]

The basic principles of modernization of the low-pressure cylinder flow path of T-185/220-12.8 turbines are presented. It is shown that its implementation allows substantial increase in economic efficiency and reliability of the turbine unit operation in the condensation and cogeneration modes. [ABSTRACT FROM AUTHOR]