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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 533 for “"Low Pressure"”.
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Fatigue in low pressure carbonitrided steels
Low pressure carbonitriding and pressurized gas quenching heat treatments were conducted on four steel alloys: 20MnCr5, 20MnCr5 + B, SAE 8620 and SAE 8620 + Nb. Bending fatigue tests were performed with Brugger specimens to simulate fatigue on the tooth root of a gear. The heat treatment parameters …
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The low pressure hydrogenation of Midlothian coal
… results obtained in this investigation, the following conclusions were drawn: 1. Midlothian coal was 31.3 percent liquefied by hydrogenation at atmospheric pressure and 185°C after 72 hours of reaction in a tetralin vehicle and using stannous sulfide as a catalyst. 2. The liquid product of the …
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Multi-Scale Transport Phenomena in Low-Pressure Plasmas
… but important, effect on the etch rate. At low pressure, the etch rate is increased, although the probability of a given ion causing an etch is decreased.
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Dynamics of High- and Low -Pressure Plasma Remediation
The use of DBDs as excimer ultraviolet (UV) lighting sources was also studied. The mixture Xe/Cl2 ≈ 99/1 was found to be an optimum gas mixture for the generation of the XeCl*. Higher applied voltage improves both the intensity and efficiency of UV photon generations. The strong attachment at high …
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Flash gas bypass concept utilizing low pressure refrigerants
… elaborate the same approach in R134a or similar low pressure refrigerant A/C systems. The main reason for this is the fact that lower pressure fluids are more affected by pressure drop, therefore flash gas removal which reduces low system side pressure drop will be more beneficial utilizing these …
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Aerodynamics of Low Pressure Steam Turbine Exhaust Systems
The low pressure (LP) exhaust system presents a promising avenue for improving the performance of large steam turbines. For this reason, LP exhaust systems have attracted the attention of the research community for decades. Nevertheless, we still lack understanding of the flow physics and loss …
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Unsteady Wetness Effects in Low Pressure Steam Turbines
… for calculating unsteady, viscous, condensing flows in multi-stage steam turbines is described. This is based on an established single-phase flow solver with nucleation and droplet growth incorporated via moment evolution equations for the poly-dispersed liquid phase. The method can be used to …
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Annular Flow in a Low - Pressure Steam - Water System
<p>Two-phase annular flow is an important aspect of two- phase flow. Three different models, Ghosal, Wallis, and Levy models, were used to calculate the pressure drop in an nular two-phase flow. The calculated pressure drop was com pared with a set of experimental data. The pressure range of the …
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Transport in Low Pressure Plasma Reactors for Materials Processing
… metal physical vapor deposition (IMPVD) at pressures of a few mTorr is being increasingly used to deposit diffusion barriers and Cu seed layers into high aspect ratio trenches. Understanding plasma-substrate interactions will be critical to designing the next generation processes as the …
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Electron Distributions in a Plasma Jet at Low Pressure
Made available in DSpace on 2014-12-05T19:16:02Z (GMT). No. of bitstreams: 1 6303248.pdf: 4837178 bytes, checksum: 85c0ec58a4c0aa500fe5adde7f6826c2 (MD5) Previous issue date: 1962
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Numerical lnvestigation of Disturbance Environments in Low Pressure Turbines
… various disturbance environments existing in a low pressure turbine (LPT) are investigated. In particular, the effects of free-stream turbulence (FST), unsteady wakes, roughness and blade oscillations on the separation-induced transition on the suction surface of a low pressure turbine blade are …
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Denitrification in low pressure distribution onsite wastewater disposal systems
… interval, and temperature on denitrification in low pressure distribution, on-site wastewater treatment and disposal systems (OSWTDS) were evaluated in this study. The treatments were surface and subsurface soil horizons; nitrified and non-nitrified wastewaters; 0.5, 1.0, and 1.5 times the …
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Geoejector : extracting geothermal fluid from a low-pressure geothermal well
To utilize a low-pressure and low-enthalpy well, a subsonic ejector system (referred to as subsonic geoejector) was developed and tested at the Theistareykir Geothermal Field in 2020 and 2021. The system connected a low-pressure geothermal well to a nearby high-pressure well to induce flow from the …
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On Aerothermal Optimization of Low-Pressure Steam Turbine Exhaust System
… challenges in the aerothermal optimization of Low-Pressure Steam Turbine Exhaust System (LPES). The first one is the high computational cost due to the complexity of LPES geometry. To make things worse, designers have to consider extra cost caused by change of constraints, multi-objective and …
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Fabricating silicon germanium waveguides by low pressure chemical vapor deposition
Low loss optical waveguide structures combining the high bandwidth of light transmission and the economics of silicon substrates have been made possible by Low Pressure Chemical Vapor Deposition (LPCVD). This work explores the fabrication, modeling, and testing of LPCVD Si Ge waveguides. Thesis …
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Low Pressure and Short-Time Silver-Sintering for Power Modules
… of long sintering time and high auxiliary pressure, which not only restricts the industrial production efficiency, but also may cause mechanical damage to the brittle chip. In this study, an innovative low-pressure and short-time silver sintering process, namely the Paste+Film method, was …
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Low Pressure Focal Plane Detectors for the K600: A design study
Magnetic spectrometers and position-sensitive particle detectors have been used for a long time in experimental nuclear physics, with the K600 high-resolution magnetic spectrometer at iThemba LABS being an example of such a system. This dissertation presents a review of the K600 magnetic …
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