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Date submitted2023-01-27
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Date accepted2023-03-04
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Date published2023-04-25
Use of the UNIFAC model in the calculation of physicochemical properties of ecotoxicants for technological and ecoanalytical purposes
- Authors:
- Vladimir G. Povarov
- Ignatyi I. Efimov
Modern development vector of environmental monitoring leads to elaboration of analytical methods for qualitative and quantitative analysis of different ecotoxicants. Many studies face the lack of information on isomers and homologues of already studied compounds. This problem cannot always be solved experimentally due to the difficulty of separating or synthesizing certain compounds; the use of group theories of solutions will help partly; using them, solubility in water or partition coefficient between two immiscible solvents is calculated for ecotoxicants. These parameters are important for solving the analytical and ecological problems. The partition coefficient in the octanol – water system is associated with a possibility of accumulation of different compounds in living organisms; the partition coefficient in the hexane – acetonitrile system can be used in gas chromatographic analysis. Solubility in water is closely associated with accumulation of ecotoxicants in water bodies, as well as with their ability to be transferred. This paper presents the capabilities of the UNIFAC model for solving physicochemical problems using the example of calculating the properties of real ecotoxicants on the basis of the available thermodynamic data. All the obtained calculated values were compared with those determined experimentally. In the case of pyrene derivatives, solubility data were obtained for the first time using a correlation group model to calculate the heat of fusion and melting temperature.
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Date submitted2016-10-28
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Date accepted2017-01-08
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Date published2017-04-14
Problems of mineral tax computation in the oil and gas sector
- Authors:
- N. G. Privalov
- S. G. Privalova
The paper demonstrates the role of mineral tax in the overall sum of tax revenues in the budget. Problems of tax computation and payment have been reviewed; taxpayers and taxation basis of the amount of extracted minerals have been clearly defined. Issues of rental content of natural resource taxes are reviewed, as well as problems of right definition of the rental component in the process of mineral tax calculation for liquid and gaseous hydrocarbons. One of important problems in mineral tax calculation is a conflict between two laws – the Subsoil Law and the Tax Code of Russian Federation (26 th chapter). There is an ambiguity in the mechanism of calculating amounts of extracted mineral resources – from the positions of the Tax Code and the Subsoil Law. The second problem is in the necessity to amend the mineral tax for oil extraction the same way as it has been done for gas extraction, when characteristics of each field are taken into account. This will provide a basis for correct computation of the natural resource rent for liquid and gaseous hydrocarbons. The paper offers recommendations for Russian authorities on this issue.
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Date submitted2010-07-27
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Date accepted2010-09-06
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Date published2011-03-21
Distribution of groups of trace elements elements by types metasomatic rocks and ores in the Elov nickel deposit
- Authors:
- O. P. Mezentseva
- I. V. Talovina
The article deals with the distribution of groups of trace elements in four selected types of metasomatic rocks and ores in the Elov deposit: chamosite metasomatic rocks and ores, which are three mineral species: a – chamosite, в – clinochlore –brendleyit-chamosite, с – clinochlore-talc-chamosite, goethite metasomatic rocks and ores, nepouite-chrysotile-lizardite metasomatic rocks and ores, and lizardite-chrysotile serpentinites. Also calculated the coefficients of accumulation of trace elements and formulated conclusions about elements are accumulation or elements are weathered of the above types of metasomatic rocks and ores of the Elov deposit.
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Date submitted2010-07-10
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Date accepted2010-09-24
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Date published2011-03-21
Value Δ34S in millerite and genesys of clinochlore-brindleyite-chamosite nickel ores in the Elov supergene deposit (North Urals)
- Authors:
- O. P. Mezentseva
- I. V. Talovina
The article deals with genesis of chamosite zone in Elov supergene nickel deposit after the example of clinochlore-brindleyite-chamosite nickel ore. According to obtained data, isotope ratio 34 S/ 32 S in millerite from these ore type varies from –35,5 to –45,6±0,6 ‰. This value corresponds to sedimentary rocks und testifies surface exogenous genesis of chamosite nickel ores.