Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 31 - 39 of 39

Full-Text Articles in Engineering

Investigating Polymer Based Scaffolds For Urinary Bladder Tissue Engineering, Srikanth Sivaraman May 2015

Investigating Polymer Based Scaffolds For Urinary Bladder Tissue Engineering, Srikanth Sivaraman

All Dissertations

Current surgical treatments for urinary bladder disorders rely on the use of autologous intestinal segments and xenografts such as small intestinal submucosa, which suffer from various complications including mechanical mismatch and graft shrinkage. Despite early promises of bladder tissue engineering, a recent report of unsuccessful clinical trials suggests that the technology needs further improvement and evaluation through animal models of bladder dysfunction. Therefore, the objective of this doctoral dissertation was to characterize a viable bladder tissue scaffold (patch) which mimics the mechanical properties of the bladder, maintains the phenotype of the BSMC seeded in it and finally, tested in vivo …


Capillary Channel Polymer Fiber-Based Scaffolds For Neural Regeneration, Atanu Sen May 2015

Capillary Channel Polymer Fiber-Based Scaffolds For Neural Regeneration, Atanu Sen

All Dissertations

Over 50 million Americans are affected by ailments to the central nervous system (CNS) and it impacts the American economy over $400 billion a year. The number of people in the United States who have spinal cord injury (SCI) has been estimated to be approximately 276,000 persons as of 2014 with a range from 240,000 to 337,000 persons. The annual incidence of SCI, not including those who die at the scene of the accident is approximately 12,500 new cases each year. Due to the limited regenerative capacity of the adult CNS and lack of clinically effective therapies, these conditions commonly …


Hazard Quantification And Loss Estimation For Combined Hurricane Wind And Flood, Bin Pei May 2015

Hazard Quantification And Loss Estimation For Combined Hurricane Wind And Flood, Bin Pei

All Dissertations

This research work focused on developing and evaluating the methodologies proposed for hazard quantification and loss estimation of the combined hurricane wind and flood. The overall research was divided into three studies. A methodology to quantify the joint occurrence probability of hurricane wind and flood was first introduced in Study I. A procedure to select ensembles of hazard-consistent full-track hurricane scenarios (i.e. with similar return periods) was proposed next in Study II. Finally in Study III, a new hurricane mitigation framework was developed using the agent-based modeling (ABM) technology to evaluate the effectiveness of incentive programs under both hurricane wind …


Linear Programming Methods For Identifying Solvable Cases Of The Quadratic Assignment Problem, Lucas Waddell May 2015

Linear Programming Methods For Identifying Solvable Cases Of The Quadratic Assignment Problem, Lucas Waddell

All Dissertations

This research effort is concerned with identifying and characterizing families of polynomially solvable instances of the celebrated NP-hard quadratic assignment problem (qap). The approach is novel in that it uses polyhedral methods based on an equivalent mixed 0-1 linear reformulation of the problem. The continuous relaxation of this mixed 0-1 form yields a feasible region having extreme points that are both binary and fractional. The solvable instances of concern essentially possess objective function structures that ensure a binary extreme point must be optimal, so that the linear program solves the qap. The ultimate contribution of this work is the unification …


Understanding The Fusion And Maturation Of Tissue Engineered Linear Blood Vessels Using Magnetic Cellular Spheroids, Timothy R. Olsen May 2015

Understanding The Fusion And Maturation Of Tissue Engineered Linear Blood Vessels Using Magnetic Cellular Spheroids, Timothy R. Olsen

All Dissertations

Cellular spheroids are attractive for tissue fabrication due to having precise control over cell and extracellular matrix (ECM) composition, the ability for upscaled production and repeatability, their three-dimensional nature and the fact that spheroids will produce their own ECM over time. A critical process in the fabrication of complex tissue structures with cellular spheroids is related to their fusion and maturation. Tissue fusion is a self-assembly process in which two or more distinct cell populations, or tissues, make contact and coalesce to form a single cohesive structure. Maturation of tissue engineered constructs involves developing the mechanical properties and ECM compositions …


Cloud-Based Strategies For Robust Connectivity And Efficient Transmission In Vehicular Networks, Ke Xu May 2015

Cloud-Based Strategies For Robust Connectivity And Efficient Transmission In Vehicular Networks, Ke Xu

All Dissertations

Leveraging multiple wireless technologies and radio access networks, vehicles on the move have the potential to get ubiquitous broadband Internet connectivity. Many studies have put lots of efforts on vehicle-to-vehicle networks for relaying strategies, popular content distribution, etc. However, in dominant infrastructure-based vehicular networks, supporting continuous and fast data transfer for today's prevalent services, e.g. video streaming, for vehicles anytime and anywhere is still a difficult research problem. By looking into such problem, impacts such as intermittent connectivity, dynamic network topology, fluctuating signal coverage, and inefficient transmissions, all result from two root causes in vehicular network- mobility and limited infrastructure …


Decision Environments To Encourage More Sustainable Infrastructure Outcomes, Earl Shealy May 2015

Decision Environments To Encourage More Sustainable Infrastructure Outcomes, Earl Shealy

All Dissertations

Physical infrastructure (i.e. roads, pipelines, airports, dams, landfills, and water treatment systems) contributes directly to sustainability outcomes such as energy and water use and climate changing emissions. The infrastructure built today will likely impact future generations for many years. Planning, design and development decisions about infrastructure are critical to the future performance of these systems. Such decisions about infrastructure are complex with multiple variables, alternative options, and design stages. To manage decisions that exceed cognitive capacity to consider all options, decision makers often create mental shortcuts (heuristics), and accompanied errors (biases). The potential cognitive biases when dealing with complex decisions …


Mechanically- And Electrochemically- Induced Damage At Metal Interfaces Of Joint Replacements And The Biological Consequences, Pooja Panigrahi May 2015

Mechanically- And Electrochemically- Induced Damage At Metal Interfaces Of Joint Replacements And The Biological Consequences, Pooja Panigrahi

All Dissertations

Retrieval analysis has emerged as one of the most direct and informative ways to analyze mechanisms of orthopaedic device failure. With a rising projected demand for revision joint arthroplasty, 268,200 revision total knee replacements (TKR) and 96,700 revision total hip replacements (THR) in 2030, metal interfaces in joint replacements are currently under intense scientific focus as the interactions among mechanical and electrochemical processes continue to challenge the orthopaedic device industry. The objective of these studies was to use implant retrieval and in in vitro analyses to determine the effects of material and mechanical properties on wear and corrosion, and to …


Design Of Reliable And Sustainable Wireless Sensor Networks: Challenges, Protocols And Case Studies, Fan Yang May 2015

Design Of Reliable And Sustainable Wireless Sensor Networks: Challenges, Protocols And Case Studies, Fan Yang

All Dissertations

Integrated with the function of sensing, processing, and wireless communication, wireless sensors are attracting strong interest for a variety of monitoring and control applications. Wireless sensor networks (WSNs) have been deployed for industrial and remote monitoring purposes. As energy shortage is a worldwide problem, more attention has been placed on incorporating energy harvesting devices in WSNs. The main objective of this research is to systematically study the design principles and technical approaches to address three key challenges in designing reliable and sustainable WSNs; namely, communication reliability, operation with extremely low and dynamic power sources, and multi-tier network architecture. Mathematical throughput …