Home – Home – Jornals – Contemporary Problems of Ecology 2012 number 4

The minor intrusions of the Edel'veis alkaline-carbonatite complex are bounded by the spurs of the North Chuya Ridge in southeastern Gorny Altai. According to Ar-Ar isotope data, the complex formed in the Middle Cambrian (~507 Ma). All of its components (alkali clinopyroxenite-melanogabbro-alkali syenite + Ca-carbonatite) occur in only one pluton. Silicate igneous rocks are equivalent in silica content and alkalinity to potassic alkaline and subalkalic mafic rocks. Apatite-phlogopitic Ca-carbonatites are enriched in P₂O₅ (up to 3.6 wt.%), Sr (~2500-5500 ppm), and REE (up to ~2000 ppm) and are, presumably, of liquation genesis. A PREMA-type plume component was a predominant magma source for the complex (ε_Nb (Т) = +6.56... +6.85). According to isotope data (⁸⁷Sr/⁸⁶Sr_(Т) ~ 0.7032-0.7039; δ¹⁸ О ~ 7.5-14.9 ‰; δ¹³ С ~ -2.7...-8.4 ‰), the fractionation of the melts was accompanied by their crustal contamination. The trace-element composition of the rocks suggests that the complex developed on a continental margin and its development was accompanied by late-collisional rifting and the mixing of moderately depleted (PREMA) and enriched suprasubduction lithospheric mantle (EM I or EM II) with continental crust. It is presumed that the alkaline and carbonatite complexes in the western Central Asian Fold Belt are of primary plume origin and form a LIP within this belt together with other associations produced by Early Paleozoic (510-470 Ma) magmatism.

The Sillai Patti carbonatite complex represents the second largest carbonatite body of the Peshawar Plain Alkaline Igneous Province of northern Pakistan. It is situated about 20 km west of Malakand, near Sillai Patti Village. Here, the carbonatite occurs along a fault in the form of a sheet striking in the NNE-SSW direction and dipping southward. The carbonatite body is about 12 km long and 2-20 m thick, predominantly intruded along the faulted contact of metasediments and granite gneiss but locally, within the metasediments.
A fission-track age of 29.40 ± 1.47 Ma was obtained for the Sillai Patti carbonatite complex. Close resemblance of the fission-track apatite age of this study with the fission-track as well as other high-temperature radiometric ages from the same and the neighboring carbonatite complexes of the alkaline belt of northern Pakistan suggests emplacement of the Sillai Patti carbonatite complex at higher crustal level and subsequent extremely fast cooling to near ambient temperatures (<60 ?C) required for the complete retention of fission tracks in apatite. The age data also point out that the fission-track age of 29.40 ± 1.47 Ma of this study is the age of intrusion of the carbonatitic magma of the Sillai Patti carbonatite complex to shallow, near-surface level.
Comparison of the uplift-induced denudation rates of the region with the world data clearly reflects the presence of a postcollisonal extensional environment in the region south of the Main Mantle Thrust during Oligocene time. This strongly negates the idea of the earlier workers of emplacement of the carbonatite complexes of the Loe-Shilman and Sillai Patti areas along thrust faults during the Oligocene.

Nabi Musa located at the northern tip of the Dead Sea at 31?48?N, 35?25?E is one of fifteen complexes of the Hatrurim Formation or the so-called "Mottled Zone" (MZ) which are fossil mud volcanoes. Self-ignition of methane during their eruptions in the Middle-Late Pleistocene caused combustion metamorphism of sediments. Melting foci have been discovered in two craters of Nabi Musa volcano, with numerous veins of paralavas having particular calcic-silicic compositions (Ca₂SiO₄- and CaSiO₃-normative). Their major- and trace-element spectra bear signature of a mixed sedimentary protolith consisting of Cretaceous marine carbonates, marl, and quartz sand. The paralavas inherit high Sr, P, and U enrichments, positive La/La* and Y anomalies, and a negative Ce/Ce* anomaly from calcareous marine sediments, including bituminous and apatite-rich chalks. The presence of quartz arenite in the protolith is responsible for relatively high Ti, Nb, Zr, and Hf, while the marl pelitic component accounts for MREE and LREE depletion. The suggested mixing models predict that the Nabi Musa paralavas result from combustion metamorphism of a sediment mixture with 53-60 wt.% chalk, 5-14 wt.% marl, and 27-44 wt.% quartz arenite. The history of mud volcanism at Nabi Musa began with small eruptions that mobilized gas and water from shallow (within 300 m) Turonian carbonate aquifers, and later explosive activity triggered violent gas blowouts from the older terrigenous reservoir of Aptian-Albian Nubian-type sandstone lying as deep as 1300-1500 m.

A camptonite dike swarm (Agardag alkali-basalt complex) in the western part of the Sangilen Upland abounds in mantle xenoliths. Mineralogical, petrographic, and petrochemical studies showed that the dikes are composed of lamprophyres of two groups, basic and ultrabasic. Ar/Ar dating of amphibole and phlogopite megacrysts yields an intrusion age for the dikes of 443.0 ± 1.3 Ma. ²⁰⁶Pb/²³⁸U dating of zircon from a glomeroporphyritic intergrowth in camptonite from one of the dikes yielded a core age of 489.0 ± 5.4 Ma. This corresponds to the time of formation of the Chzhargalanta granite-leucogranite complex (489.4 ± 2.6 Ma). The ²⁰⁶Pb/²³⁸U age of the zircon rim is 444.0 ± 7.5 Ma. The ages obtained by Ar/Ar dating of amphibole and biotite megacrysts and by U/Pb dating of the magmatic rim of zircon crystal from the camptonite coincide within the dating error, which indicates that the camptonite dikes formed in the Late Ordovician. These dikes are the oldest-known example of mantle-derived xenoliths in mafic volcanic rocks from an off-craton setting. These are samples of the Upper Ordovician lithospheric mantle.

The Cambrian section of the western limb of the Chekurovka anticline was studied, with layer-by-layer collection of animal fossils. This permitted us to refine the biostratigraphic division of this section. Four biostratigraphic units (beds) with small shelly fossils were identified: Lapworthella tortuosa , Lapworthella bella , Mobergella radiolata , and Rhombocorniculum cancellatum . They characterize most of the Tommotian and Atdabanian Stages of the Lower Cambrian. The Lower Tyuser Subformation and the Sekten Formation were constrained by small shelly fossils for the first time. Numerous trilobite finds helped to reveal intervals correlating with the Delgadella anabara-Nevadella and Judomia-Uktaspis (Prouktaspis) Regional Zones in the upper Atdabanian.
The upper Sekten Formation (black shales) forms the Kuonamka Formation. Within this interval, the following trilobites were found: Triplagnostus gibbus , Tomagnostus sibiricus , Pseudanomocarina sp., Eodiscus oelandicus , Paradoxides sacheri , and Ptychagnostus aff. atavus . They are widespread in the vast territory of the eastern Siberian Platform, within the Kuonamka Formation.
Also, Korobovia khorbosuonica , Charaulaspis postprimus , and Hebediscus convexa trilobites were observed, which had been found earlier in the Khorbosuonka River section (Olenek uplift). This permits a detailed correlation between these localities.
Similarity was observed between Triangulaspis annio trilobites and young Charaulaspis . This casts doubt upon the fact that the first Triangulaspis annio finds in the northeastern Siberian Platform belonged to the upper Atdabanian.

Organic matter of Cretaceous and Cenozoic deposits in the Indigirka-Zyryanka basin was studied by bituminological analysis and chromato-mass spectrometry. The regularities of distribution of alkanes and polycyclic aromatic hydrocarbons depending on the catagenesis of fossil organic matter are shown. Sesquiterpanes of the drimane series have been recognized in the Cretaceous deposits, and tetracyclic biomarkers of phyllocladane (kaurane), in the Cenozoic ones. The biomarkers were produced from terpenes of conifers, and the identified set of pentacyclic oleanenes are the products of angiosperms flourishing in the Paleogene and Neogene. As evidenced from geochemical indices, the Cenozoic deposits did not reach the PT -conditions of "the main oil formation zone" and should not be used for the quantitative evaluation of the regional petroleum potential. Nevertheless, the Cenozoic clayey units can be perfect isolating horizons for fluids migrating from more ancient, including Cretaceous, deposits.

Crustal kinematic characteristics such as strain and displacement rates are important in the monitoring of present-day processes in zones of seismic and industrial hazard. Strain measurements on different temporal and spatial baselines reveal potentially hazardous zones. Data on coseismic displacements and strain can be used to refine earthquake models, and long-term characteristics are important in searching for earthquake precursors and studying the rheology of the crust and fault zones. Tilt measurements in the adit of the Talaya seismic station (51.68?N, 103.64?E, South Baikal region) began in 1985; strain measurements, in 1990; and GPS measurements, in 2000.
The data reflect time variation in the local strain parameters and permit a comparison with the GPS data on the region and western Central Asia. The data on strain variations obtained in the Ala-Archa underground observatory (42.63?N, 74.50?E, North Tien Shan) are analyzed together with those obtained in the region by GPS methods.
Strain rates on very long baselines were determined using data from permanent IGS stations for Central Asia - the territory expanding from Dzungaria in the south to the Siberian Platform in the north and from the Tien Shan in the west to Lake Baikal in the east. We consider the example of using strain gaging and GPS data to construct a dislocation model and refine the parameters of the Kultuk earthquake (South Baikal region, 27 August 2008, M = 6.3).

Biopolymer-based drilling fluids affect data of high-frequency isoparametric induction logging. Highly conductive fluid invaded into drilling-induced flaws produces zones of high resistivity contrasts. Thus, the logs acquire new features that never appear in drilling with argillic mud. These effects have been simulated with regard to high resistivity contrasts for the case of flawed borehole walls, and the modeling results were checked against experimental data.

A mudcake formed on the borehole wall between a fluid-filled porous formation and the borehole fluid can affect Stoneley wave propagation used to estimate the formation permeability. The mudcake effect on the permeability dependence of radial oscillations of borehole fluid is investigated in a system with a source generating radial acoustic waves in the borehole and hydrophones (pressure sensors) that record the respective attenuating oscillations of the borehole fluid. The permeability of the porous formation is estimated from theoretical permeability dependence of the attenuation exponent, knowing the time dependence of the exponential attenuation of borehole fluid oscillations.

Inversion of laterally heterogeneous MT responses collected by a dense synchronous 2D array allows a new approach to estimating electrical anisotropy. The procedure includes solving an overdetermined equation system, assuming distant-dependent anisotropy in a smooth approximation. Inversion is performed using an effective conductivity tensor, which approximates some limited domain of the survey polygon. The algorithm for simulating 2D array MT responses with the effective conductivity tensor approach implies correlation of surface components of the EM field measured simultaneously at all stations within the chosen domain of the survey polygon. The suggested technique of data acquisition and processing ensures reconstruction of the full conductivity tensor from laterally variable components of the EM field.

To make our recommendation on optimizing a demographic policy, we consider how people's reproductive behavior influences regional birth rates. Our case-study on the Vologda Oblast suggests that there is a trend to have a few children in families as people's reproductive plans could not be realized because of people's lack of confidence in the future economic stability in the country or stable family partner's relationships, or their dissatisfaction with their incomes, housing conditions, and healthcare and educational services. Within our case-study we developed the recommendations on the objectives to be included in the demographic policy for the Vologda Oblast and an interagency coordination plan to ensure higher birth rates in this region.

The paper identifies the features and reasons of regional clustering; it describes the basic approaches to definition of such spatial and economic phenomenon; and it also considers a typology of clusters and the role which an investment cluster could play in synergetic economics.

The paper analyzes the economic development of Siberia (12 RF subjects which make up the Siberian Federal District) on key indicators included in the Siberian Socio-Economic Development Strategy up to 2020. The authors offer their improvements to be included into federal and regional policies aimed at attracting investments for realization of basic priorities of the Strategy, and proposals on higher investments to be made into Siberia by the Russian central and regional governments, and business-communities.

The paper explodes the myth that electric power prices in Russia are lower than those of the world. Being calculated on the base of purchasing power parity, such prices for industries were 2.5 times higher in Russia than in Norway and 1.4 times higher in Finland and the USA in 2008. Analyzing the wholesale and different consumers' electric power prices over 2001-2011, we can state that 2009, which is the year following the reform of the RAO Unified Energy System of Russia, stands out against a ground of other years under study. We also can state that despite a 50% drop in the real prices set by regional power generating companies, the real prices for different consumers were higher by 9%. Subject to the different drops in wholesale electric power prices taken place after the reform, we can identify zones which are characterized by different levels of competitiveness among power generating companies. Moreover, under lack of both competitive environment among energy power suppliers and governmental control in the post-reform period, network suppliers used to overstate their required gross operating incomes to calculate prices by RAB method.

The paper considers the characteristic features of intersectoral megapro-jects, the place which such projects play in a system of governmental strategic planning and management, and a necessity of administrative procedures to coordinate both strategic interests and investment policies of the government and business. We offer our methodological approach to building technologic-organizing schemes of strategic planning and management though applying tools of modeling. We also suggest the mechanisms to coordinate the investment decisions made by participants involved in megaprojects - such mechanisms include indicators which assess whether management schemes of implementation of investment program in such megaprojects are well balanced and effective.

A priority task for developing the Baikal region (the Irkutsk Oblast, Buryatia Republic, and Zabaikal region) is to modernize the existing chemical industry, and to build new facilities which are oriented on usage of both natural gas and its components, and producing high value added products. Being used as the power-generating and process fuel, gas could allow replacing expensive fuel oil and solving many social and ecologic problems. The Kovykta Gas Condensate Field ready for its commercial operation could become a resource base for such gasification. The paper also presents the economic assessment of building the new gas processing works and gas-chemical plants in the territory of the Baikal region; the efficiency of methane usage as fuel by different consumer's groups; a comparative analysis of several regional gas supply systems; and what is required the recommendations proposed to be realised.

The paper makes an ecointensity analysis of the economies of the RF regions over the crisis and post-crisis periods. We apply the Gini coefficient, and Atkinson and Theil indices. Having made a comparative analysis of the results obtained, we can state that according to the indices under study, there is a significant regional inequality observed.

Due to the fact of renewed interest to the project on transbasin water transfer from Ob-Irtysh Basin to the Central Asia countries widely discussed in the 1970s up to the first half of the 1980s, we analyze whether this project was reasonable, and show the principle methodological errors made in it. We describe the legal foundations of projects on transbasin water transfer as well as a procedure of ecologic-economic assessment which are necessarily be complied with and made. We question the economic and ecological wisdom of this project at present.

The paper discusses the proposals on promoting the development of small business which is included in the Siberian Socio-Economic Development Strategy up to 2020; it also describes the mechanisms, which the author finds reasonable for achieving the strategic future goals; and the author presents her recommendations based on the principles and provisions of theory of reforms.

The assessment of the contribution from the main sources of chemical material into the composition of water in the Novosibirsk water reservoir was carried out. It was confirmed that the chemical composition of water in the Novosibirsk reservoir has been formed essentially due to chemicals inflow from the Ob river.

Analysis of metals, including the group of heavy metals, in the muscular tissue of fish (Leuciscus idus, Rutilus rutilus, Perca fluviatilis, Sander lucioperca) from the Novosibirsk reservoir and the Ob river near the dam of the Novosibirsk water-power station during the year 2009 is presented. The revealed interspecies and interpopulation (biotope) distinctions in metal concentrations are most probably connected with the differences in the food of fish. The level of metal concentrations in the muscular tissue of fish does not exceed the standard level accepted in Russia for fresh fish products.

Dynamics of metal content in higher aquatic plants (macrophytes) in a small water reservoir Bugach during the years 1998-2006 was studied. A comparative estimation of metal content in six macrophyte species (Тypha latifolia L., Тypha angustifolia L., Polygonium amphibium L., Potamogeton perfoliatus L., Potamogeton pectinatus L., Phragmites australis(Cav.) Trin. ex Steud.) showed that metal concentrations in them generally do not exceed those known from literature. Cluster anаlysis showed that the macrophyte species under study form two ecological groups with respect to metal content: submerged plants (hydrophytes) and emergent aquatic plants (heliophytes).

Efficiency of the transfer of gamma-emitting radionuclides in food chains including macrophytes, zoobenthos, fish bentho- and ichthyophages was estimated at the radiation-polluted region of the Enisey river. Essential differences in the efficiency of the transfer of natural and technogenic radionuclides between the components of different trophic levels were revealed. Substantial species-related differences in the accumulation of radionuclides in ichthyophage fish from food were revealed.

Results on the influence of petropollution on the number and age structure of rotifers Brachionus plicatilis under laboratory conditions are presented. The influence of petropollution on the population of rotifers was studied under modeling experimental conditions with the oil concentrations of 5; 10; 20; 40; 80; 160; 320 ml/l of water. Three stages of adaptive reactions of rotifers depending on the concentration of oil were revealed: stimulation, resistance and depression. The age stability of rotifers to petropollution was revealed.

In the course of monthly sampling during the years 2008-2010, two regions of the littoral of the Enisey river were compared, one of them (conventionally pure) was situated upstream of Krasnoyarsk and the other (conventionally polluted) downstream of Krasnoyarsk. The concentrations of heavy metals, oil products, phenols, biogenic elements and essential polyunsaturated fatty acids (PUFA) in various components of the river ecosystem were determined. It was discovered that the anthropogenic pollution causes a decrease in the resources of essential PUFA in the biomass of the upper links of the food chain of the river ecosystem.

Assessment of ecological risk for the change in the content of essential polyunsaturated fatty acids (PUFA) in the plankton of lakes under global warming is carried out. The analyzed hazards are temperature, dissolved phosphorus and nitrogen, phyto- and zooplankton structure. The main risks are related not only with temperature increase, but indirect effects of warming. The critical link in risk assessment of PUFA is phytoplankton structure due to the particularly favorable growth conditions for cyanobacteria in nutrient rich waters in shallow lakes and reservoirs.

A brief review is presented concerning the methods for producing synthetic and composite polymer materials those can decompose under the influence of environmental factors. The advantage of these materials is demonstrated in comparison with the “classical” industrially produced petroleum-based polymers. Main ways and means are indicated to impart the biodegradable properties to polymeric materials.

Different models of defect ordering in strongly nonstoichiometric perovskite-like oxides based on strontium ferrites/cobaltites Sr(Co_0.8Fe_0.2)O_3–δ, (Sr_0.7La_0.3)(Co_0.5Al_0.3Fe_0.2)O_3–δ, (Sr_0.7Сa_0.3)(Co_0.5Al_0.3Fe_0.2)O_3–δ, Sr(Co_0.75Nb_0.05Fe_0.2)O_3–δ, Sr(Co_0.7Nb_0.1Fe_0.2)O_3–δ and Sr(Fe_0.95Mo_0.05)O_3–δ (2.5 < (3–δ) < 2.7) are considered. Diffraction patterns of a number of samples differing in cation composition and degree of nonstoichiometry exhibit intensive reflections that are characteristic of the perovskite structural type with weak wider superstructural peaks. It is demonstrated by means of computer modelling of X-ray scattering on the crystals with different defects that such a diffraction pattern can correspond to three models of ordering of the oxygen vacancies: the formation of a homogeneous structure with the ordered state of oxygen vacancies (structural elements of the low-symmetry phase) and the formation of nano-heterogeneous systems (brownmillerite ABO_2.5 + perovskite ABO₃) of two types. In the first case, the components of the system have lamellar shape and interchange in one direction (a unidimensional disorder). In the second case we speak of the structure of brownmillerite domains turned with respect to each other at an angle of 90°, with different methods of redistribution of the perovskite component – at interfaces or in the form of separate domains. It is demonstrated with the help of two-dimensional diffraction of X-rays that this texture is observed not only at the nano-level but also for the samples with microdomains.

Results of the investigation of aerosol in the region of Seversk (Tomsk Region) performed in 2010 using mass spectrometry and atomic emission with inductively coupled plasma are presented. With the help of GIS methods, geochemical indicators of technogenic aerosol of the Siberian Chemical Combine were revealed, and the basic aureoles of their distribution were determined. Comparative analysis of the results and the data published previously is presented.

Total heavy metal content in the soil in the region of the storage of wastes from pyrometallurgical works (Belovo Zinc Plant) was investigated. It was established that the high level of zinc and copper pollution is conserved also after the plant stops its operation. The maximal pollution was detected in the direct vicinity of clinker mound; it exceeds the background values for zinc by a factor of 60. At a distance of 300 m pollution decreases (17-fold excess over the background value) but it can be followed even at a distance of 5 km from the Belovo Zinc Plant (5-fold level). The fraction of mobile forms of a number of elements extracted through stepwise leaching was determined. For the soil with the heaviest pollution (рН of water extract 5.58), the fraction of mobile zinc forms exceeds the MPC by a factor of 66, copper by a factor of 2, manganese is below the normal value, mobile forms of nickel were not detected. Thus obtained row depicts the geoecological condition of soil in the region of waste storage of the Belovo Zinc Plant.

Physicochemical state of YBa₂Cu₃O_{6 + δ} powder subjected to mechanochemical treatment was studied by means of thermogravimetry, X-ray diffraction, iodometry and X-ray photoelectron spectroscopy. It is demonstrated that the indicated treatment causes broadening of the range of variation for oxygen parameter (δ) and an increase in the chemical activity of yttrium/barium cuprate above the limit that can be attributed to a decrease in particle size. The discovered features are due to increased non-equilibrium character of activated YBa₂Cu₃O_{6 + δ}, including uncharacteristic combination of the oxidation numbers of copper and oxygen ions interacting with each other (Cu³⁺, O^–).

Kinetic characteristics and mechanism of silver dissolution in the course of leaching the gold-silver alloy by nitric acid solutions in the presence of ammonium nitrate under a pressure of gas phase reaction products were investigated by means of the method of rotating disk. Parameters were revealed for the process occurring in the external diffusion, kinetic and transition zones. Factors have been found those determine the dissolution rate of the metallic silver.

A new approach is presented with respect to solving the problem of the complex processing of a low-grade manganese-containing raw material, based on deep reductive melting with the separation of metal and silicate parts of the melt and the amorphization of the latter by via cooling in a thermal shock mode. As the result of these processes, a XRD amorphous foamed silicate with wide application potentialities is formed as well as ferromanganese silicon segregation is observed.

The effect of nanocomposite obtained by means of solid-phase mechanochemical synthesis from non-fruit parts of buckthorn (buckthorn-based serotonin powder, BBSP) on the immunophysiological status of dwarf hamsters during autumn decrease of photoperiod was studied. It was shown that the addition of BBSP to food in curds has no effect on the amount of curds ate by the animals, does not eliminate the basic morphological changes developed in the animals under the conditions of decreasing daylight hours, does not affect the degree of ecdysis. At the same time, the addition of BBSP promotes reliable decrease in body mass, and increase in the spontaneous activity of the animals during the first four weeks of the experiment, conservation of the summer type of thermoregulation (high energy consumption for the compensation of the action of cold, and prevalence of chemical thermogenesis) and an increase in the humoral immune response to the introduction of sheep erythrocytes.

An effect of inhibitory additive on the kinetics of sediment formation in highly paraffinic oil was investigated. It has been demonstrated that the maximum rate of sediment formation occurs within the first minutes of the process. The inhibitory additive promotes greatly decreasing to a considerable extent the rate of sediment formation in the oil due to the retention of solid paraffin hydrocarbons in the bulk. An influence of the inhibitory additive upon the group composition of sediments and the composition of paraffinic hydrocarbons was investigated.

A novel technology has been developed for conditioning cold mineralized groundwater inherent in the northern Tyumen Region, Russia. The technology involves the use of three chemicals such as hydrogen peroxide, potassium permanganate and sodium hydroxide to provide purifying the water from iron, manganese, hydrogen sulphide and silicon up to the standards of drinking water, as well as the stabilization treatment of water. Rationale for choosing the type of reagent for stabilization treatment and the results of testing the technology are presented.

A catalytic process of the oxygen-driven oxidation of aspen wood and enzymatic lignin as a waste of processing aspen wood into biobutanol was investigated in a static reactor using a rotating magnetic stirrer in an alkaline medium. The effect of temperature and of a mode of alkali feeding into reactor on the yield of syringaldehyde and vanillin was studied. It has been established that the fermentation lignin is close to the native lignin being much more efficient as compared with lignosulphonates for using as a feedstock for the preparation of vanillin and syringaldehyde.  Separation is experimentally realized concerning the stages of lignin oxidation by oxygen, on the one hand, and the retro-aldol cleavage of oxidation products into vanillin and syringaldehyde, on the other hand.

Using the mechanochemical method during 30 min in the planetary mill, we synthesized the samples of hydroxyapatite (HAP) modified with silicate ions in the amount of 0.1, 0.2, 0.4 and 0.8 molar fractions of the ion in HAP at the given molar ratio Са/(Р + Si) = 1.67. As a result of activation in the air medium, hydroxyapatite with the average crystallite size of ~20 nm was formed. The mechanochemically sy6nthesized samples contain carbonate ion substituting the phosphate ion, with the formation of carbonatehydroxyapatite of B type; its amount decreases with an increase in the amount of silicate introduced. Modification of hydroxyapatite with silicate ions is a competing reaction for phosphate substitution with carbonate. Depending on the ratio of silicate to carbonate amounts in hydroxyapatite structure, the mechanism of substitution changes. In the case of predominance of the carbonate ion in apatite, the composition corresponds to the general formula Сa_{10 - (x - y)/2}(PO₄)_{6 - (y + x)}(SiO₄)_y(CO₃)_x(OH)₂ (х > у). In the case of the equal number of substituents (х = у) silicate-substituted hydroxyapatite has the stoichiometric composition with the general formula Ca₁₀(PO₄)_{6 - (y + x)}(SiO₄)_у(CO₃)_х(OH)₂. In the case of predominance of silicate ion (х < у), charge compensation occurs due to the formation of vacancies in the positions of (ОН)^- groups: Ca₁₀(PO₄)_{6 - (y + x)}(SiO₄)_у(CO₃)_х(OH)_{2 - у}. After annealing the samples, the silicate group occupies the positions of phosphate ion in hydroxyapatite structure with the formation of vacancies in the positions of (ОН)^- group; the composition is described by the general formula Са₁₀(PO₄)_{6 - x}(SiO₄)_x(OH)_{2 - x х}.

An influence of the synthesis conditions upon the direction of o-cresol alkylation conditions with camphene in the presence of sulphated zirconia was investigated. There were O- and C-alkylation products obtained with a different structure of terpene substituent. It is demonstrated that the presence of sulphated zirconia results in the formation of 4-isobornylphenol, 4-isocamphylphenol and para-alkylated phenol with the methyl groups at positions 1, 4, 7 in the terpene moiety. The catalysis with sulphated zirconia allows obtaining para-alkylated 2-methylphenol with the isobornyl structure of terpene substituent, with a yield of 58 %.

An influence of the molecular structure of hydrocarbons and halogenated derivatives thereof upon the acute toxicity was studied with the use of a 2D simplex representation of the molecular structure and partial least squares technique. Adequate QSAR models were obtained, wherefrom structural fragments have been revealed those could cause the toxicity level to increase. With the help of QSAR models a relative influence of some physicochemical factors upon the acute toxicity was assessed.