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Full-Text Articles in Engineering

Investigation Of Combustion Characteristics Of A Heavy-Duty Diesel Engine Retrofitted To Natural Gas Spark Ignition Operation, Jinlong Liu Jan 2018

Investigation Of Combustion Characteristics Of A Heavy-Duty Diesel Engine Retrofitted To Natural Gas Spark Ignition Operation, Jinlong Liu

Graduate Theses, Dissertations, and Problem Reports

The conversion of existing diesel engines to natural-gas spark ignition operation by adding a gas injector in the intake manifold for fuel delivery and replacing the diesel fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. As the conventional diesel combustion chamber (i.e., flat head and bowl-in-piston) creates high turbulence, the engine can operate leaner, which would increase its efficiency and reduce emissions. However, natural gas combustion in such retrofitted engines presents differences compared to that in conventional spark ignited engines. Subsequently, the main goal …


Evaporative Techniques For Stormwater Runoff Alleviation, Allison M. Arnold Jan 2015

Evaporative Techniques For Stormwater Runoff Alleviation, Allison M. Arnold

Graduate Theses, Dissertations, and Problem Reports

Current climate changes have led to a projected steady increase in rainfall over the next several decades, notably in the Greater Pittsburgh Area. Even without this predicted increase the urbanization of many regions has altered local natural environments, which in the past stored, shed and evaporated this runoff water effectively, maintaining balance within the water table. These added rainfall forecasts, combined with America’s growing trend to develop and expand the urbanization of our natural earth, has resulted in a growing surplus of stormwater runoff water affecting these cities and their suburbs, leaving many sanitation departments unable to meet the heightened …


Pitting Corrosion And Corrosion Fatigue Crack Growth Behavior Of Oil-Grade Alloy 718 In Sodium Chloride Solution, Ting Chen Jan 2014

Pitting Corrosion And Corrosion Fatigue Crack Growth Behavior Of Oil-Grade Alloy 718 In Sodium Chloride Solution, Ting Chen

Graduate Theses, Dissertations, and Problem Reports

Oil-grade nickel-base alloy 718 has been recently used in the oil and gas industry for downhole drilling components especially for the parts of the bottom hole assembly (BHA) due to its superior mechanical properties, good corrosion resistance, non-magnetic properties and ability to be heat treated to various strength levels. As the modern oil and gas industry explored into coastal and marine locations, deeper and deeper wells have been drilled with high pressure high temperature, making the demand for increased strength and good toughness super critical for alloys used in ultra-deep wells drilling. Moreover, the existence of high concentrations of chloride …