A measuring method for the distribution behavior between supercritical carbon dioxide and water by a microchip was developed. A surface modification of the microchannel by dichlorodimethylsilane induced a spontaneous phase separation of the supercritical carbon dioxide and aqueous phases in the microchip. The maximum contact time of the aqueous phase to the supercritical carbon dioxide phase wa...

This study examined the effects of sub- and supercritical water pretreatments on the physicochemical properties of crab shell α-chitin and its enzymatic degradation to obtain N,N'-diacetylchitobiose (GlcNAc)2. Following sub- and supercritical water pretreatments, the protein in the crab shell was removed and the residue of crab shell contained α-chitin and CaCO3. Prolonged pretreatment led to α...

The present study is aimed at a detailed analysis of supercritical water structure based on the combination of experimental vibrational spectra as well as molecular modeling calculations of isolated water clusters. We propose an equilibrium cluster composition model where supercritical water is considered as an ideal mixture of small water clusters (n=1-3) at the chemical equilibrium and the vi...

Trichlorocarbanilide has widely been used in cosmetics and household products, but the extremely low solubility of trichlorocarbanilide in water constrains the development of water-based products. In order to enhance the bioavailability, trichlorocarbanilide were micronized using supercritical fluid. Supercritical carbon dioxide was selected due to relatively low critical temperature and the ra...

We describe a finite-dimensional reduction method to find solutions for a class of slightly supercritical elliptic problems. A suitable truncation argument allows us to work in the usual Sobolev space even in the presence of supercritical nonlinearities: we modify the supercritical term in such a way to have subcritical approximating problems; for these problems, the finite-dimensional reductio...

Triterpene compounds like betulin, betulinic acid, erythrodiol, oleanolic acid and lupeol are known for many pharmacological effects. All these substances are found in the outer bark of birch. Apart from its pharmacological effects, birch bark extract can be used to stabilise semisolid systems. Normally, birch bark extract is produced for this purpose by extraction with organic solvents. Employ...

The gas-like mass transfer properties and liquid-like solvation characteristics of supercritical fluid make it a promising medium in performing extractory and chromatographic separations, i.e., supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC), respectively. The tunable solvation properties of supercritical carbon dioxide not only improve SFE's efficiency and spe...

We consider supercritical accretion onto a compact object when the accretion rate exceeds its value derived from the Eddington limit: ṀEdd = LEdd/c . We use the scenario that was proposed by Shakura and Sunyaev (1973) for the supercritical regime, according to which matter flows out of the gas-disk surface under radiation pressure. An analytic solution of the accretion-disk structure is obtaine...

Abstract: A thermodynamic consistency test developed for high pressure binary vapor-liquid mixtures is applied to mixtures containing a supercritical solvent and an ionic liquid. Several authors have reported vapor-liquid equilibrium data on the binary systems supercritical CO2 + 1-butyl-3-methyl imidazolium hexafluorophosphate {[bmim][PF6]}, supercritical CO2 + 1-butyl-3-methyl imidazolium nit...

In this study, the non-catalytic supercritical method has been studied in utilizing dimethyl carbonate. It was demonstrated that, the supercritical dimethyl carbonate process without any catalysts applied, converted triglycerides to fatty acid methyl esters with glycerol carbonate and citramalic acid as by-products, while free fatty acids were converted to fatty acid methyl esters with glyoxal....