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Showing 1 to 14 of 14 for “"supercritical extraction"”.
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Supercritical extraction of coal
Supercritical extraction of coal is removal of a select fraction of the coal by a solvent which is slightly above its critical temperature and above its critical pressure. The objective of this dissertation was to understand the mechanism of supercritical extraction, to test some promising …
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Effects of a combined supercritical extraction/thermal cycle on binder removal cycle time, yield, residual carbon, and defect formation in multilayer ceramic capacitors
In this work, a combined cycle consisting of a supercritical extraction cycle (SCE) followed by a thermal cycle (TC), was used to remove binder from green multilayer ceramic capacitors. The dielectric was barium titanate and the binder consisted of poly(vinyl butyral) plasticized with phthalates. …
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Supercritical fluid extraction of rice bran with adsorption on rice hull ash
… oil was extracted using environmentally-friendly supercritical carbon dioxide at varying conditions. Experimental treatments included pressure (27.6, 41.4 and 55.2 MPa), temperature (40 and 60 oC) and flow rates (25, 45 and 65 g/min) of supercritical carbon dioxide. Extracts collected at different …
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Estrazione di composti biologicamente attivi da piante della Sardegna
This research work has been focused on the supercritical fluid extraction and characterization of volatile oils having interesting biological activities, possibly susceptible of therapeutic applications. A further aim of this work was to separate biologically active molecules and nutraceuticals by …
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Strategies for the analytical determination of thermally labile sulfur-containing environmental pollutants
… was achieved in two ways: 1) the development of supercritical fluid extraction procedures suitable for these compounds and 2) the interface of a sulfur-selective detector to chromatographic techniques appropriate for thermally labile compound analysis. Supercritical fluids, particularly CO₂, have …
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Hyphenated fourier transform infrared spectrometry: techniques for separations and analysis
… FT-IR techniques specifically involving supercritical fluid extraction (SFE), supercritical fluid chromatography (SFC), and liquid chromatography (LC). Three studies are presented. The first involves the application of SFE/FT-IR towards the extraction of finishes from textile fibers. SFE …
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Supercritical fluid extraction of non-traditional matrices
Supercritical extraction (SFE) has most often been linked to the use of modified or unmodified CO₂ for the recovery of relatively non-polar analytes from solid matrices. The objective of this research was to expand current supercritical fluid (SF) techniques to the recovery of analytes from …
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Reaktive nahe- und überkritische Extraktion von Braunkohlen mit Alkanolen
Gegenstand der vorliegenden Arbeit ist die Wandlung von Weichbraunkohlen in nie-dermolekulare Produkte durch Reaktion mit Alkanolen, insbesondere Ethanol, unter nahe- bzw. überkritischen Bedingungen. Als potenziell verwertbare Produkte ent-stehen eine ethanollösliche Fraktion, die hohe Anteile an …
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Quantitative Analysis of Additives in Low Density Polyethylene Using On-line Supercritical Fluid Extraction /Supercritical Fluid Chromatography
… products. Traditional liquid solvent/polymer extraction methods, which involve dissolution/precipitation, are time-consuming, uneconomical, and the recoveries are significantly lower than 90%. In recent years, analysis with supercritical fluids (SFs) has emerged as an alternative analytical …
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Supercritical fluid extraction as a sample preparation technique for the isolation of polar pharmaceutical compounds
The low polarity of the supercritical fluid extraction (SFE) solvent, CO₂, causes problems when applying this technique to polar compounds. The objective of this research was to expand the applicability of SFE to include polar compounds. The first phase of this research investigated "inverse SFE", …
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Supercritical fluid extraction applied to environmental pollutants from Chesapeake Bay sediment
Sample preparation via supercritical fluid extraction (SFE) has been increasingly used to determine polynuclear aromatic hydrocarbons (P AHs) in environmental samples. As an alternative sample preparation technique, SFE offers the distinct advantages of greatly reduced sample preparation time, …
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Optimal Analysis of Sulfonamides From Biological Matrices Using Supercritical Fluids
… the effect of temperature and pressure on the supercritical fluid extraction (SFE) of sulfonamides from a spiked sand matrix. Temperature effects were either positive or negative with respect to extraction rate and total recovery, depending on the pressure and extraction fluid employed. The …