A new pressure-measurement technique which employs the tools of molecular spectroscopy has recently received considerable attention in the fluid mechanics community. Measurements are made via oxygen-sensitive molecules attached to the surface of interest as a coating, or paint. The pressure-sensitive-paint (PSP) technique is now commonly used in stationary wind-tunnel tests; this thesis presents the extension of the technique to advanced turbomachinery applications. New pressure- and temperature-sensitive paints (TSPs) have been developed for application to a state-of-the-art transonic compressor where pressures up to 2 atm and surface temperatures up to 140° C are expected for the first-stage rotor. PSP and TSP data has been acquired from the suction surface of the first-stage rotor of a transonic compressor operating at its peak-efficiency condition. The shock structure is clearly visible in the pressure image, and visual comparison to the corresponding computational fluid dynamics (CFD) prediction shows qualitative agreement to the PSP data. / Master of Science

A microprocessor based air pressure controller is discussed. The particular implementation was designed around an existing pressure measurement, and display unit. The unit is controlled by a 6809 microprocessor. It is shown that due to the many functions that the unit must perform and control, a microprocessor based system is a good choice. The controller is economical since it uses standard chips, yet it is very accurate since it uses state of the art pressure transducers. Experimental results and the user friendly interface will also be discussed. A commented listing of the controller software, and the circuit diagrams are appended. / Master of Science

During the initial heating of hydraulically bonded castable refractories, dehydration of cement phases causes build-up of high levels of internal steam pressure. If this pressure exceeds material strength, explosive spalling results. A probe capable of measuring internal steam pressures"in-situ" has been developed and tested. Correlation of cement calorimetry and pressure data suggests that castable heating schedules can be modified to reduce explosive spalling. / Master of Science

This work investigates the interactions between impact devices and material response in the realm of solid mechanics, utilizing explicit finite element analysis and experimental methods based on the split-hopkinson pressure bar. It focuses on understanding how tools like jackhammers use hammer strikes to generate pressure waves, then the wave is transferred through a chisel to materials such as rocks to cause fracture. The interaction between the wave and the rock is complex. Under dynamic loading the mechanical response of materials changes and significant losses occur due to reflections and inefficient pressure states. This research explores how chisel geometry can be optimized to control critical parameters influencing rock fracture, including stress state, pulse length, and peak pressure. The use of notches to influence the stress state, periodic boundaries to influence the pulse length and pressure amplification in tapers the increase the pressure showed an improvement in efficiency in jackhammers. Additionally, this work extends insights of the concept of pressure amplification in solids, to liquids inside tapered pipes, enhancing the understanding of phenomena like pulse pressure amplification in arteries and water hammer effects in piping systems. Two innovative contributions emerge from this work: a novel amplifier design for water cannons, improving these machines efficiency and showing promise for applications in water jet cutting and drilling, and a novel process for extruding nanocrystalline magnesium. This process leverages pressure amplification and impact-induced plastic shear deformations to refine crystal size, offering a new avenue for producing various nanocrystalline materials.

The aim of the research was to investigate the effects of three parameters of the artificial heart on the (+) dP/dt max. The study was conducted using a mock circulation which was connected to an artificial heart. The data were collected using the COMDU software developed for the computer which monitors the artificial heart. Stepwise regression analysis was utilized to test the three hypotheses. Two of the null hypotheses for the study could not be rejected, as the independent variable did not significantly affect (+) dP/dt max. Although the third hypothesis was accepted, the results were not clinically significant. Limitations in the study were multicollinearity among the independent variables, small sample size, and the inability of the mock circulation to represent human responses.

published_or_final_version / Social Work / Master / Master of Social Work

published_or_final_version / Civil Engineering / Master / Master of Philosophy

No description available.

No description available.

No description available.