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2009, №3

pp. 3-6

Articles

The Development of Des-Glaucine Production Method in Subcritical Water Media

S.N. Borisenko, A.V. Bicherov, O.V. Pavluk, N.N. Kharabaev, N.I. Borisenko, E.V. Vetrova, V.I. Minkin, R.N. Borisenko, A.V. Lekar.

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Key words: subcritical water, glaucine, des-glaucine, ESI-MS, NMR

The isomerization of non-racemic mixture of glaucine isomers into des-glaucine was held in subcritical water media under 200-300°С with the yeld 53 %. The structure of the product was proved with nuclear magnetic resonance spectroscopy (NMR) and electrospray ionization (ESI-MS).

2009, №3

pp. 7-15

Articles

Key words: supercritical fluid, oil extraction coefficient, thermobaric conditions

An experimental setup for studying the displacement of oil in a wide range of pressures (up to 20 MPa) and temperatures (up to 373 K), that reflects thermobaric, geological, and physico-chemical conditions in real oil-beds and parameters of displacing agents is constructed. The results of experimental displacement of kerosene by supercritical carbon dioxide at 313 ÷ 353 K and 7 ÷ 12 MPa demonstrate a high efficiency of this technology for the output of low-viscosity oils.

2009, №3

pp. 16-24

Articles

Influence of Supercritical and Water-alcohol Extracts from Halocynthia aurantium onto Gametes, Zygotes and Embryo of Sea Urchin

A.L. Drozdov, T.I. Chizhova, V.M. Chudnovskiy, V.I. Yusupov, O.I. Pokrovskiy, O.O. Parenago, N.G. Busarova, S.V. Isai, V.N. Bagratashvili.

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Key words: supercritical and water-alcoholic extracts, Ascidia, Halocynthia aurantium, bio-test, sea urchins, embryo, exogastrulation, Infusoria

Strongylocentrotus intermedius is studied. It is showen that water-alcohol extract has no remarkable effect onto gametes, process fertilization, development of embryo and larvae of sea urchin. If the SC extract is added during the gamete fusion, the fertilization and cell-division of blastomers are not affected, but the gastrulation becomes abnormal — the exogastrulas are formed. Moreover, during the cultivation of embryo in a cultural medium with SC extracts, the growth of Infusoria is depressed. It is likely that the origin of differences in the biological effects of SC and water-alcohol extracts ought to look for in peptide or secondary metabolite fractions, since no distinct differences in li pid fractions are detected.

2009, №3

pp. 25-38

Articles

The Dispersion of Polymer Materials Using Supercritical Fluid Media

I.M. Gilmutdinov, V.F. Khairutdinov, I.V. Kuznetsova, A.A. Mukhamadiev, F.R. Gabitov, F.M. Gumerov, A.N. Sabirzyanov.

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Key words: supercritical fluid, antisolvent, phase diagram, rapid expansion, RESS, nanoparticles, polyisobutylene, polystyrene, modification

On the experimental test bench Thar RESS-100-2 Base the dispersion process of polyisobutylene in the range of temperatures 45 ÷ 120 °C and pressures 100 ÷ 350 bar was investigated; the particle size was 30 ÷ 1000 nm. The possibility of managing the particle size by varying of the process parameters was revealed. The new method of polymer particles modification during the rapid solution expansion was suggested. In the modification process the effect of agglomeration is suppressed and the particles are covered by modifier (NaCl). The availability of application of superctitical fluid antisolvent to the dispersion of polymers to nanoparticles is based. The experimental test bench for this method is described. Catching method for polymer nanoparticles formed in antisolvent was suggested. While dispersing polystyrene in the system “tolyene - polystyrene - supercritical carbon dioxide” under pressure 40 ÷ 150 bar and temperature

2009, №3

pp. 39-55

Articles

Key words: germaniumsilicate glass, subcritical and supercritical water, etching, fibreoptic reflectometry

Etching of germaniumsilicate singlemode optical fibre edge in sub- and supercritical water was studied by means of fibreoptic reflectometer (FOR) and scanning electron microscopy (SEM). It was shown that in the case of germaniumsilicate core edge the etching rate is much higher than for silica cladding edge. This leads to the formation of a “well” at the edge of the fibre, which becomes deeper as etching goes forward. The oscillatory character of the FOR signal is caused by an interference effect of the light reflected from the edge of the core and the edge of the cladding. This interference allows one to calculate the etching rate at different pressures and temperatures of water and, therefore, in its different states (liquid, vapour and supercritical). The lowest measured etching rate (10 -3 nm/s) was measured at 200 °C and 54 atm; the maximum etching rate (~30 nm/s) was reached at 400 °C and 246 atm. The etching rate increases with temperature in accordance with Arrhenius law (apparent activation energy 58 ± 3 kJ/mole). The character of the FOR signal changes at the late stages of etching from regular oscillating to random noisy due to the formation of defects of different size on the fibre edge, which are easy to observe using the SEM imaging.

2009, №3

pp. 56-105

Reviews

Key words: real-gases, diesel engine, computational fluid dynamics

The objective of the research outlined in this paper was to develop the analytical approximations for calculating real-gas properties (pvTdata, thermodynamic functions: internal energy, enthalpy, and entropy, and specific heats) of vapor-phase n-alkanes from C1 (methane) to C14 (normal tetradecane), O2, N2, H2O, CO, CO2 and H2 within the range of pressure 0.05 ≤ p ≤ 20 MPa and temperature 280 ≤ T ≤ 3000 K aimed for implementation into computational fluid dynamics (CFD)-codes simulating the operation process in modern Diesel engines. The analytical approximations have been developed based on available literature data and on the new equation of state for moderately dense gases. The approximations reported are rather simple and therefore can be used directly in CFD codes. Approximations for mixing rules are also provided.