A PID controller was designed to control the performance of an oil-heated fractal-like branching microchannel desorber for use in an ammonia-absorption refrigeration system. Both the amount and concentration of ammonia refrigerant generated at the desorber can be controlled by choosing the rectified circulation ratio as the controlled variable in a...
Transportation plays such an important role in daily living that, without it, a person might be totally homebound. The nation’s air travel system for persons with disabilities is an area of substantial dissatisfaction, with both passengers and the airline industry recognizing the need for improvement. One of the major concerns...
Droplet formation from a flexible nozzle plate driven by a prescribed-waveform excitation of a piezoelectric is numerically investigated using a computational fluid dynamics (CFD) model with the VOF method. The droplet generator with a flexible nozzle plate, which is free to vibrate due to the pressure acting on the plate,...
Driven by the need for high energy-density power sources, demand has
stimulated the development of small-scale engines. A small-scale engine
with a fuel supply could replace batteries and utilize higher energy-density
liquid hydrocarbon fuels; such an advance could deliver a new age of
portable devices. Currently, operable small-scale engines exist;...
An experimental study of absorption of ammonia into a constrained thin film of ammonia-water solution is presented. A large aspect ratio microchannel with one of its walls formed by a porous material is used to constrain the thickness of the liquid film. Experiments were performed at a pressure of 1,...
People often grow increasingly culturally confused when spending significant amounts of time in a foreign land. Identity can become lost only to reform in the image of the host society. This thesis presents a creative nonfiction series of essays that explore the author’s loss of self and contextual identity, the...
Air travel presents several problems for passengers with disabilities.
One in particular is how they get from their wheelchair and to an aircraft seat.
The commonly used manual transfer method is hazardous to the assistants
and the passenger. There are other alternatives, but they have plenty of room
for improvement....
Oregon Department of Transportation’s bridge no. 9743b is a multi-span, two-girder steel deck bridge connecting the busy interstates 5 and 205. Vertical cracks have been detected in the welded girder-to-crossbeam connections at the bents. Distortion-induced fatigue is suspected to be responsible for the cracking. Linear elastic beam analysis, 2-D and...
Students participating in international engineering internships are still relatively rare. It is commonly held that more engineering students would choose to intern abroad if there were role models available, as there are in other disciplines. Profiles of past students, participants, and Alumni serve as role models to perspective students allows...
It is hypothesized that increases in pressure drop due to vapor generation during boiling in microchannels can be reduced by extraction of vapor at its point of inception. Ultimately, this local vapor extraction decreases the pressure drop required to drive the flow through a fractal-like branching, microchannel flow network within...