Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 524 for “"supercritical"”.
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Numerical Study of Mixing of a Supercritical Jet in a Supercritical Environment
… flow physics and modeling requirements of a supercritical (SC) nitrogen jet injected into a tank of quiescent SC nitrogen. The goals of this work are twofold: to inform the design of injectors and combustion chambers for use in the direct-fired supercritical CO2 (s-CO2) power generation cycle …
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Supercritical Carbon Dioxide Extraction
… of this thesis is to explore the properties of supercritical carbon dioxide (CO<sub>2</sub>). In addition, the feasibility of building a small-scale low cost system will be explained. A supercritical fluid is a fluid which exhibits properties between liquid and gas with liquid like densities and …
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Capillary supercritical fluid chromatography
… of a gas chromatograph for capillary supercritical fluid was demonstrated. The resulting instrument was used to characterize the performance of capillary columns manufactured specifically for SFC applications. The columns were tested for inertness, efficiency, and immobilization before …
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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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Lateral outflow from supercritical channels
… of laterally diverted flows of stormwater from a supercritical channel for treatment. A range of design flows were tested and evaluated for a trapezoidal channel with a lateral outflow pipe. Lateral pipe angle, pipe invert, and vane configurations were tested for outflow efficiency and to observe …
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Supercritical Water Gasification of Biomass
… can be overcome by a novel technology: supercritical water gasification (SCWG). SCWG is based on reacting biomass with water above its critical point (T > 374.1°C; P > 22.1 MPa). Thanks to the unique properties of supercritical water, high gaseous yields can be achieved, as well as …
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Supercritical fluid chromatography - mass spectrometry
… quality separations other techniques, such as supercritical fluid<br/>chromatography (SFC), are now being considered. The key advantage of SFC is minimal<br/>solvent waste, which is particularly important in preparative SFC, leading to fast sample<br/>recovery. Hence it is important to explore …
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Solubility in supercritical carbon dioxide
… determination of the solubility of compounds in supercritical carbon dioxide are described. A comparative study is made of the methods used in the measurement of the concentration of benzoic acid and caffeine in supercritical carbon dioxide. The difference in measurement techniques did not have …
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Supercritical flow in collapsible tubes
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1980.
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Development of a heat-transfer correlation for supercritical water in supercritical water-cooled reactor applications
… analyzed and a new heat-transfer correlation for supercritical water was developed. This experimental dataset was obtained within conditions similar to those for proposed SuperCritical Water-cooled nuclear Reactor (SCWR) concepts. Thus, this new correlation, for forced convective heat transfer in …
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Adiabatic Packed Column Supercritical Fluid Chromatography
A well-known problem in supercritical fluid chromatography is the drastic decrease in chromatographic performance at temperatures above 40 C and outlet pressures below 120 bar. This phenomenon has been attributed to isenthalpic expansion and cooling of the mobile phase and poor heat transport under …
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Thermoacoustic Oscillations in Supercritical Fluid Flows
Pressure oscillations in supercritical Jet-A fuel flowing through four parallel, heated tubes connected to common manifolds have been observed in this study. Tests were performed with fuel inlet temperatures ranging from 70F to 700F, and fuel pressures ranging from 360-700 psi. Total fuel flow rate …
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Supercritical water gasification of waste residues
… conversion of motor oil as a model compound, in supercritical water. Used motor oil was identified as a main waste compound leading to increased land fill concerns and supercritical water gasification is introduced as a method of decomposing such waste residues with high efficiencies. This study …
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Supercritical Water desulfurization of crude oil
Supercritical Water (SCW) desulfurization was investigated for both model sulfur compounds and Arab Heavy crude. In part 1, the reactions of alkyl sulfides in SCW were studied. During hexyl sulfide decomposition in SCW, pentane and CO+CO₂ were detected in addition to the expected six-carbon …
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Supercritical Fluid Chromatography of Ionic Compounds
… the elution of ionic analytes via packed column supercritical fluid chromatography (SFC). Firstly, we focused on the elution of sodium arylsulfonate analytes by using various ionic additives, such as lithium acetate, ammonium acetate, tetramethylammonium acetate, tetrabutylammonium acetate, and …
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Quantitative Analysis of Additives in Low Density Polyethylene Using On-line Supercritical Fluid Extraction /Supercritical Fluid Chromatography
… lower than 90%. In recent years, analysis with supercritical fluids (SFs) has emerged as an alternative analytical technique because SFs afford higher diffusivity and lower viscosity. In this research, an on-line Supercritical Fluid Extraction (SFE)/Supercritical Fluid Chromatography (SFC) …
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Design of supercritical carbon dioxide centrifugal compressors
Los potenciales problemas que puedan presentarse en el futuro asociados a la escasez de recursos energéticos convencionales (combustibles fósiles), han promovido desde hace décadas el desarrollo de sistemas renovables por un lado y por otro de sistemas de alta eficiencia. En este ámbito, los ciclos …
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Nanoparticle formation and coating using supercritical fluids
… jet breakup and solvent evaporation into supercritical fluid (SC CO_2) is studied using high speed charged coupled device (CCD) camera facilitated with double shot particle image veloimetry (PIV) laser and a high pressure view cell. Particles formation using SAS is studied. …
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