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Evaluation Of The Engine Exhaust Particle Sizer (Eeps) For Real-Time Measurements Of Diesel And Biodiesel Exhaust Particulate Matter, James Robert Dunshee
Evaluation Of The Engine Exhaust Particle Sizer (Eeps) For Real-Time Measurements Of Diesel And Biodiesel Exhaust Particulate Matter, James Robert Dunshee
Graduate College Dissertations and Theses
Even at low concentrations, the criteria air pollutant particulate matter (PM) is an environmental and public health hazard. Emissions levels legislated for modern diesel vehicles are so low (~90% lower than 2003) that it has become difficult to accurately measure PM by the regulatory metric: the mass of particles collected on a filter (i.e., the gravimetric method). Additionally, gravimetric analysis cannot measure real-time emission rates, and therefore is unable to characterize high-emitting transient events (e.g., engine starts, stop-and-go driving). By an alternate method, PM can be estimated by measuring the number-weighted particle size distribution (PSD) and calculating mass with a …
Nonlinear Ball Chain Waveguides For Acoustic Emission And Ultrasound Sensing Of Ablation, Stephen Herbert Pearson
Nonlinear Ball Chain Waveguides For Acoustic Emission And Ultrasound Sensing Of Ablation, Stephen Herbert Pearson
Graduate College Dissertations and Theses
Harsh environment acoustic emission and ultrasonic wave sensing applications often benefit from placing the sensor in a remote and more benign physical location by using waveguides to transmit elastic waves between the structural location under test and the transducer. Waveguides are normally designed to have high fidelity over broad frequency ranges to minimize distortion - often difficult to achieve in practice. This thesis reports on an examination of using nonlinear ball chain waveguides for the transmission of acoustic emission and ultrasonic waves for the monitoring of thermal protection systems undergoing severe heat loading, leading to ablation and similar processes. Experiments …