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Gordadze G.N.,Moscow State University | Okunova T.V.,Moscow State University | Giruts M.V.,Moscow State University | Erdnieva O.G.,Kalmykian State University | Koshelev V.N.,Moscow State University
Solid Fuel Chemistry | Year: 2011

The mild thermolysis of resins and asphaltenes from petroleum of different genotypes was performed. It was found that the same C14-C16 polyalkyl-substituted bicyclo[4.4.0]decanes were formed as a result of the thermolysis of resins and asphaltenes. The relative concentration of the thermodynamically more stable isomer 2, 3 ,3 ,7 ,7-pentamethylbicylo[4.4.0] decane in the thermolysis products of resins was higher than that in the thermolysis products of asphaltenes and close to equilibrium concentrations. Simultaneously, the amount of the thermodynamically less stable isomer 1, 2, 3, 7, 7-pentamethylbicylo[4.4.0]decane generated in the thermolysis products of asphaltenes was greater than that in the thermolysis products of resins, and its relative concentration was far from equilibrium concentrations. The degree of the maturity of organic matter, which was evaluated based on the relative thermodynamic stability of C15 sesquiterpanes in the thermolysis products of resins and asphaltenes, increased in the order asphaltenes-resins- petroleum. © Allerton Press, Inc., 2011. Source


Badmaev Ch.M.,Moscow State University | Giruts M.V.,Moscow State University | Erdnieva O.G.,Kalmykian State University | Koshelev V.N.,Moscow State University | Gordadze G.N.,Moscow State University
Petroleum Chemistry | Year: 2011

Oxygen-containing compounds that are known to be precursors of petroleum hydrocarbons have been subjected to catalysis on an aluminosilicate catalyst. It has been found for the first time that along with C11-C12 monoalkylated adamantanes, which are typically present in crude oils, the homologous series of 1- and 2-n-alkyladamantanes up to and including n-heptyladamantanes are generated via the catalysis (monoalkyl-substituted adamantanes with a substituent heavier than the ethyl radical have never been found in any crude oil). It has been shown that, with the increasing degree of conversion, C13-C17 adamantanes disappear and only 1- and 2-methyl- and ethyladamantanes remain in the catalyzates. The absence of high-molecular alkyladamantanes (C13 and higher) in crude oils is supposedly attributed to relatively high maturity of crude oil. © 2011 Pleiades Publishing, Ltd. Source


Abaturov B.D.,RAS Severtsov Institute of Ecology | Dzapova R.R.,Kalmykian State University
Biology Bulletin | Year: 2015

An interfaced analysis of change of forage vegetation, nutrition of saigas (Saiga tatarica), and their state in the steppe regions of Russia is performed. It is noted that the percent of graminoids has increased considerably and the proportion of forbs has decreased in the vegetation of current pastures, which has had a negative impact on the nutrition and state of saigas. It is shown that the lower nutritional value of graminoids has caused a decrease in the digestibility of forage used by saigas and does not provide the physiological requirements of the animals. It is established that modern steppe pastures, where gramineous communities prevail, are of little use or absolutely unsuitable for the stable existence of saiga populations. Only separate dwelling places with an abundance of forbs continue to provide adequate nutrition for saigas and well-being for their local groupings. © 2015, Pleiades Publishing, Inc. Source


Mikulikova K.,Academy of Sciences of the Czech Republic | Romanov O.,Kalmykian State University | Miksik I.,Academy of Sciences of the Czech Republic | Miksik I.,Cardiovascular Research Center | And 4 more authors.
The Scientific World Journal | Year: 2012

The saiga horns have been investigated the using of modern analytic methods. High-performance liquid chromatography (HPLC) with mass-spectrometric (MS and MS/MS) detection and polyacrylamide gel electrophoresis (PAGE) were used. It could be concluded that basic proteins of the saiga horns are keratins and collagen. The basic representation protein in all samples is keratin type I microfibrillar (from sheep), keratin type II microfibrillar (from sheep), collagen type I ( 1) (from bovine) and collagen type I ( 2) (from bovine). Free amino acids we determined in all samples are nontreated by enzyme. Copyright © 2012 Kateina Mikulkov et al. Source


Okunova T.V.,Moscow State University | Giruts M.V.,Moscow State University | Erdnieva O.G.,Kalmykian State University | Koshelev V.N.,Moscow State University | Gordadze G.N.,Moscow State University
Solid Fuel Chemistry | Year: 2010

The distribution of biomarker hydrocarbons in the thermolysis and thermocatalysis products of oxygen-containing compounds (possible petroleum hydrocarbon precursors) was studied by gas chromatography-mass spectrometry. It was found that n-alkylcyclohexanes and steranes were generated in the course of thermolysis along with expected hydrocarbons-n-alkanes and isoprenes, which resulted from the loss of a functional group. In this case, the molecular-weight distributions of n-alkanes and n-alkylcyclohexanes correlated well with each other. In the course of thermocatalysis, the homologous series of n-alkanes and n-alkylcyclohexanes were also generated; however, an n-alkylcyclohexane distribution maximum had an even number of carbon atoms in the molecule (C 18). It was experimentally found that the sterane fragments of oxygen-containing compounds formed upon thermolysis were thermodynamically unstable; this was supported by the formation of biological C 27-C 29 5α, 14α, 17α, 20S, and 20R and 5β, 14α, 17α, and 20R (coprostane) steranes as a result of thermolysis. Unlike thermolysis, all of the four epimers of regular C 27-C 29 (5α, 14α, 17α, 20S, and 20R and 5α, 14β, 17β, 20S, and 20R) steranes were formed as a result of thermocatalysis. It was found that the relative distribution of biomarker hydrocarbons in the thermolysis products of various oxygen-containing compounds largely reflected the structure of the parent organic substance, as compared with that upon thermocatalysis in the presence of active aluminosilicate. © 2010 Allerton Press, Inc. Source

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