Pedicle screw breakage and loosening remain as clinical complications of short segment instrumentation procedures for spinal stabilization. This study has directly visualized and measured elastic, plastic and total vertebral pedicle trabecular bone full-field strains in the regions immediately surrounding the pedicle screw during pedicle screw insertion by utilizing functional microCT...
A miniature reciprocating expander is being developed as part of a larger program to develop a heat actuated heat pump for portable applications. By utilizing the higher energy density of liquid hydrocarbon fuels relative to batteries, a heat actuated heat pump would be able to provide cooling for much longer...
The decision sequences used for troubleshooting of complex electro-mechanical systems are often ad hoc and less than optimal. This research investigated Decision Analysis and Bayesian Networks for generating an optimal decision sequence for troubleshooting. The model that was used in this research was the bleed air control system of the...
The use of a permeable membrane to mechanically constrain a film of water with an area of 12 cm² and a thickness of 150 μm in a gas/liquid contactor was investigated. The membrane separated the vapor and liquid phases, and a stiffener
plate made from a gas-permeable material was used...
Dynamic modeling of the atmospheric flight mechanics of a projectile equipped with an uncontrolled internal rotating disk is investigated and a modified projectile linear theory is established. It is shown through modeling of this type of projectile that several coefficients of the epicyclic dynamics are altered, leading to changes in...
The focus of this study is the effective prioritization of customer requirements in collaborative product development. The CR priorities are often retrieved by questioning and interviewing targeted customers. But the targeted customer might not always be easily questioned, because they might not always be obvious or clearly known. If customers...
Population counts of aquatic insects are a valuable tool for monitoring the water quality of rivers and streams. However, the handling of samples in the lab for species identification is time consuming. An aquatic insect imaging device was designed as part of a system to automate aquatic insect classification and...
Local material damage that occurs within cellular solids, such as polymer foams and trabecular bone, and precedes local fractures of the cell struts or walls is called micro-damage. The accumulation of micro-damage within cellular solids is often undesirable, although it is thought to be vital to the development and health...
Recent studies of flow boiling within microchannels have shown high heat fluxes, leading to successful design and testing of compact heat exchangers, cooling systems for electronics and other high efficiency, miniature components. An experimental study of flow boiling of a concentrated salt solution in microchannels is presented. Experiments examined flow...
A method for real time in-flight prediction of the ground impact point of an indirect fire projectile is investigated. The method investigated is comprised of a combination of an impact point predictor and an extended Kalman filter state estimator based on modified linear theory. The modified linear theory model is...
Launch uncertainties in uncontrolled direct fire projectiles can lead to significant impact point dispersion, even at relatively short range. A model predictive control scheme for direct fire projectiles is investigated to reduce impact point dispersion. The control law depends on projectile linear theory to create an approximate linear model of...
Control issues are investigated for a parafoil and payload system with left and right parafoil brakes used as the control mechanism. It is shown through dynamic modeling and simulation that parafoil and payload systems can exhibit two basic modes of lateral control, namely, roll and skid steering. Using a small...
