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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.

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 $${{f}_{{{{{\text{O}}}_{{\text{2}}}}}}}$$ 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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/dm3), and the highest sums of ions were recorded in the wintertime in the lakes isolated from the outlets (446−743 mg/dm3). 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/dm3, and in Lake Semenovskoe and Lake Khlystov Zaton −0.8 and −0.63 μg mg/dm3, 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 NO3−, 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.

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.

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.

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.

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 Al2O3, CaO, Na2O, and TiO2, 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.

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% TiO2), 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.

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 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.

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.

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.

This work addresses the isotopic heterogeneity of the Archean lithospheric mantle by the example of high-Mg, moderate-alkali, LILE and LREE-enriched Panozero sanukitoid massif, which is located in the Central Karelia, southeastern Baltic Shield. Initial Nd and Sr isotope characteristics were determined for mantle source of the massif. ɛNd(T) in the source are plotted below DM line, varying from + 0.7 to + 1.4 (+1.1, on average). The 87Sr/86Sr(T) ∼ 0.7017 significantly exceeds that of depleted mantle and reflects change of Rb/Sr ratio in the source due to metasomatic reworking of mantle. Data on Pb isotope composition of potassium feldspars indicate that source of monzonites of the Panozero Massif had lower μ (238U/204Pb) = 8 and higher (238Th/232U) = 4.05 relative to primitive mantle.

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.

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.

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.

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.

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.

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.

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

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.

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.