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Showing 1 to 20 of 195 for “"High-pressures"”.
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Development of a CNG intensifier for high pressures
… storage source (20 - 200 bar) to a constant high discharge pressure (200 bar). The intensifier delivers variable amounts of gaseous fuel (5 - 43 kg/hr) at a maximum required pressure ratio of 10:1 for fueling a heavy duty bus diesel engine which is converted to a gas-diesel engine. Based on a …
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Production of high pressures with a magnetic pinch.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1968.
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First Principles Simulations of Hydrogen and Helium at High Pressures
… hydrogen, helium and hydrogen-helium mixtures at pressures beyond 200 GPa. We find very good agreement between both simulation methodologies for pressures beyond 600 GPa. From the equation of state calculations, an analysis of the miscibility properties of the mixture is performed. We find that …
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Crystal structure prediction at high pressures: stability, superconductivity and superionicity
… on structures and stable phases that emerge at high pressure. We explore three distinct systems. We first apply the ab initio random structure searching (AIRSS) technique and density functional theory (DFT) calculations to investigate the high-pressure behaviour of beryllium, magnesium and …
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Synthesis and investigation of boron phases at high pressures and temperatures
… were crystallized from a boron-platinum melt at high pressures (6-11 GPa) and high temperatures (1450-1875 K). An average size of the as-grown isometric crystals was 60 μm to 80 μm in maximum dimension. The crystal structure is in good agreement with the literature data. Detailed investigation of …
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Amorphisation Mechanisms of Metal-Organic Frameworks under High Pressures and Temperatures
… being advantageous in many applications, the high porosity and specific bonding characteristics of crystalline MOFs can, however, make them susceptible to pore collapse and amorphisation under pressure. This limits the practical effectiveness of MOFs in their most commonly synthesised form of …
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A study of the electrical behavior of gases at high pressures
Thesis: Sc. D., Massachusetts Institute of Technology, Department of Electrical Engineering, 1951
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Some Aspects of the Crystal Chemistry of Perovskites under High Pressures
… structures and theoretical analysis of high-pressure phase transitions of representative perovskites. Chapter 1 and 2 introduce the perovskite structures, tilting classification and descriptions. The structures in each of the 15 tilt systems have been decomposed in to the amplitudes of …
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First principles molecular dynamics simulation of carbon at high pressures and temperatures
… of materials. The key to this method is a highly efficient means for computing the electron density as a function of the positions of the nuclei, which then leads to accurate forces on the nuclei. In this thesis we extend the original method based on finite temperature density functional …
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Siderophile Element Partitioning at high Pressures and Temperatures : Implications for Core Formation Processes
… Sb, Ge, Pb, Ag, Au, P and As has been studied at pressures between 11 and 23 GPa and temperatures of 2342 K to 2911 K by performing partitioning experiments in a multi-anvil apparatus. This work has been primarily focused on volatile elements, because previous studies and therefore core formation …
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Elastic properties of mantle minerals by multiple methods and at high pressures and temperatures
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-08-01
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Volumetric Properties and Viscosity of Fluid Mixtures at High Pressures: Lubricants and Ionic Liquids
… collected using a variable-volume view-cell at pressures up to 40 MPa and temperatures up to 398 K. A unique high pressure rotational viscometer was developed to study the effect of pressure, temperature, and shear rate on viscosity while also allowing for the simultaneous examination of phase …
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Viscosity modeling of solvent-water-heavy oil/bitumen systems at high pressures and elevated temperatures
… viscosity when it is in liquid phase. At a higher temperature, water as a vapour shows its better ability in diluting heavy oil/bitumen than some solvents (e.g., CO2 and C3H8). In addition to enabling dynamic and accurate viscosity prediction for complex mixtures, this framework can be …
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Phase Behaviour of Alkane Solvent(s)-CO2- Water-Heavy Oil Systems at High Pressures and Elevated Temperatures
… alkane solvent(s)–CO2–water–heavy oil systems at high pressures and elevated temperatures. A new alpha function in the Peng–Robinson equation of state (PR EOS) has been developed for water component to improve its prediction for water vapour pressure in a wide temperature range. Subsequently, a …
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A Comparison of Crushing Parameters of Graphite Composite Thin-Walled Cylinders Cured in Low and High Pressures
… negative environmental effects correlated with high-pressure composite curing methods. Experimental, theoretical, and numerical approaches are used to explore both low and high-pressure curing cycles and how the two different processes affect final cured parts. Quasi-static uniaxial compression …
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Quantification of Phase Behaviour and Physical Properties of Solvents-Heavy Oil/Bitumen-Water Systems at High Pressures and Elevated Temperatures
… between the measured and calculated vapour pressures. The reduced temperature has its optimum value of 0.59 for the two EOSs, while 0.60 is recommended for practical use. The mutual solubility for n-alkanes/n-alkylbenzenes-water pairs is correlated using the PR-EOS together with the two …
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Iron spin crossovers at high pressures and temperatures and their effects on materials relevant tot he Earth’s lower mantle and core
… of the perovskite structure and remains in the high-spin state throughout the pressure and temperature conditions of the Earth’s lower mantle. Furthermore, a study on the electronic behavior of Fe in a Fe2+-rich aluminous silicate glass and a Fe3+-rich sodium silicate glass infers that no sharp …
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