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2009, №1

сс. 3-17

Reviews

Key words: fine crystalline corundum, manganese doped corundum, supercritical water fluid, solid phase transformation

Production of biodiesel from natural oils  and fats can be achieved using various technologies briefly discussed in this  review. A particular appealing concept for production of green diesel is  selective catalytic deoxygenation of renewables leading to diesel fuel  products. This reaction can be performed over Pd on active carbon supports with  saturated and unsaturated fatty acids and their derivatives.

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2009, №1

сс. 18-48

Articles

Key words: supercritical fluids, chemical and phase equilibria, phase diagrams, critical point, multicomponent mixture, non-ideality, thermophysical behaviors, monoterpenes, a-pinene, heteroazeotrops, mathematical modeling

The mathematical and calculating models  were developed to solute the specific research problems on thermodynamics of  multicomponent and multiphase mixtures. The features of chemical and phase  equilibria were examined both for the ideal-gas approximation and the  non-ideality. The conditions of equilibrium phase stability were studied for multi  phase systems. The calculation results of specific phase diagrams, binodal and spinodal  are demonstrated for the appropriate reaction mixtures. The new interpretation of  mathematical model was suggested for the localization of critical point,  especially for fixed multicomponent chemical mixtures. The new variation of  classical homotopy method was developed for the soluting of complex nonlinear  equations systems, which are the princi ples of concerned mathematical models. The  some anomalous phase profiles and the critical curves were analyzed to  demonstrate the necessity of taking into account the pointed features at the  planning of experiments, the reactor parameters calculations. The examples of  specific multicomponent non-ideal mixtures indicate the possibility of  thermodynamic and thermophysical behaviors calculations (entropy, enthalpy and  heat capacity; thermal reaction effect, adiabatic warming up). It was noted  that the cubic state equations are quite suitable for the prediction of property  deviations from the ideal-gas state and can be used for the prognosis of behavior  anomaly at the critical point surrounding.

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2009, №1

сс. 49-56

Articles

A New Continuous Method for Monitoring of Phase Behaviour of Complex Mixtures at High Pressures and Temperatures

A.A. Novitsky, M. Hou, E.E. Pérez, J. Ke, W. Wu, V.N. Bagratashvili, M. Poliakoff.

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Key words: supercritical fluids, phase behavior, hollow fibers

New method to monitor phase behavior of  mixtures at high pressures and temperatures        was developed on basis of continuous  sampling by use of glass capillary. Such technique        gives opportunity not to disturb  equilibrium in the system and to get information        about phase state in continuous flow  systems at different stages of process. As a detector        the flame-ionization detector (FID) was  chosen due to the fact that our solvents are        not flammable and will not give signal. Method  was validated using two different setups        on systems: water.ethanol and CO2 acetone.

2009, №1

сс. 57-65

Articles

Spectral Features of Subcritical Carbon Dioxide in Nanopores

V.G. Arakcheev, V.N. Bagratashvili, A.A. Valeev, V.B. Morozov, A.N. Olenin, V.K. Popov, D.V. Yakovlev.

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Key words: subcritical carbon dioxide, nanopores, adsorption and condensation in pores, shift of critical point, CARS-probe

Coherent anti-stocks Raman scattering  spectra measured in the range of Q-branch of ν1 vibrational  transition are used to reveal the state of carbon dioxide in nanopores of Vicor  glass. The measurements were carried out in a high pressure optical cell at  room        (20.5 °C) and subcritical (30.5 °C) temperatures and CO2 pressures up to saturation value Psat  for each temperature. In  addition to the main spectral component assigned to gaseous CO2 molecules, the second, low frequency component appears in the        spectra at pressures close to Psat. This second  component is determined by the contribution of CO2 molecules  inside pores. Spectral deconvolution taking into account the interference of  these two bands allows one to estimate spectral features of the
        second (low-frequency) component for each  temperature. The bandwidth of lowfrequency component decreases with CO2 pressure at 20.5 °C,  which is caused by transition of CO2 from adsorbed stated  to condensed state in the pore. At subcritical        temperature 30.5 °C the spectral width of the second  component is independent of pressure and corresponds to the value measured in  free volume at supercritical conditions, which is likely due to the  low-temperature shift of critical point in        nanopores.

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2009, №1

сс. 66-77

Articles

Luminescent Characteristics of Vicia faba L. the Bean Leaves Treated with SF-Extracts of Reynoutria sachalinensis

S.A. Glazunova, V.A. Karavaev, O.I. Pokrovskiy, O.O. Parenago, M.K. Solntcev, M.S. Tishkin, L.E. Gunar.

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Key words: supercritical fluid extraction, Reynoutria sachalinensis, slow fluorescence induction, thermoluminescence

The effect of supercritical fluid (SF)  extracts of giant knotweed Reynoutria  sachalinensis on photosynthetic  activity of Vicia faba L. bean leaves was studied by slow  fluorescence induction (SFI) and thermoluminescence (TL) methods. The treatment  of plants        with extracts led to the enhancement of  their photosynthetic activity. The maximum stimulating effect was observed for  extract obtained using carbon dioxide with 2% of ethanol as co-solvent. The  observed stimulating effect is assumed to be bound with        increasing of carries pool of the  photosynthetic electron transport chain of plant leaves by quinonic compounds  flux into plant cells.

doi:

2009, №1

сс. 78-84