Mechanical Engineering Commons^™

Tooth Cusp Radius Of Curvature As A Dietary Correlate In Primates, Michael Anthony Berthaume

Open Access Dissertations

Tooth cusp radius of curvature (RoC) has been hypothesized to play an important role in food item breakdown, but has remained largely unstudied due to difficulties in measuring and modeling RoC in multicusped teeth. We tested these hypotheses using a parametric model of a four cusped, maxillary, bunodont molar in conjunction with finite element analysis. When our data failed to support existing hypotheses, we put forth and tested the Complex Cusp Hypothesis which states that, during brittle food items breakdown, an optimally shaped molar would be maximizing stresses in the food item while minimizing stresses in the enamel. After gaining …

Scaling Reversible Adhesion In Synthetic And Biological Systems, Michael David Bartlett

Open Access Dissertations

Geckos and other insects have fascinated scientists and casual observers with their ability to effortlessly climb up walls and across ceilings. This capability has inspired high capacity, easy release synthetic adhesives, which have focused on mimicking the fibrillar features found on the foot pads of these climbing organisms. However, without a fundamental framework that connects biological and synthetic adhesives from nanoscopic to macroscopic features, synthetic mimics have failed to perform favorably at large contact areas. In this thesis, we present a scaling approach which leads to an understanding of reversible adhesion in both synthetic and biological systems over multiple length …

Multiphase Flows With Digital And Traditional Microfluidics, Michael Andrew Nilsson

Open Access Dissertations

Multi-phase fluid systems are an important concept in fluid mechanics, seen every day in how fluids interact with solids, gases, and other fluids in many industrial, medical, agricultural, and other regimes. In this thesis, the development of a two-dimensional digital microfluidic device is presented, followed by the development of a two-phase microfluidic diagnostic tool designed to simulate sandstone geometries in oil reservoirs. In both instances, it is possible to take advantage of the physics involved in multiphase flows to affect positive outcomes in both.

In order to make an effective droplet-based digital microfluidic device, one must be able to precisely …

Effect Of Total Awake Time On Drivers' Performance And Evaluation Of Training Intervention To Mitigate Effects Of Total Awake Time On Drivers' Performance, Abd Malek Abdul Hamid

Open Access Dissertations

Driving while sleepy, drowsy or fatigued are leading contributors to road crashes. Sleepiness, drowsiness and fatigue usually occur at the end of a prolonged period of time during which an individual has been awake. Although these factors have been heavily researched, it is not clear how one of their primary causes, a prolonged total awake time (TAT), might affect driving skills such as hazard anticipation, hazard mitigation and attention maintenance, three skills that are crucial for safe driving.

The first experiment investigated how these three driving skills are affected by prolonged TAT, and if so to what extent. Forty-eight participants …

Techno-Economic Feasibility Study Of Ammonia Plants Powered By Offshore Wind, Eric R. Morgan

Open Access Dissertations

Ammonia production with offshore wind power has the potential to transform energy and fertilizer markets within the United States. The vast offshore wind resource can be converted directly into liquid ammonia using existing technologies. The liquid ammonia can then be transported around the country via rail, truck, barge or pipeline and used as either a fertilizer or a fuel. This thesis reviews the technologies required for all-electric, wind-powered ammonia production and offers a simple design of such a system. Cost models based on the physical equipment necessary to produce ammonia with wind power are developed; offshore wind farm cost models …