Engineering Commons^™

Effect Of Confinement And Temperature On The Behavior Of Eps Geofoam, Amsalu Birhan

Dissertations - ALL

EPS geofoam blocks underlying compacted soil and structural loads become subjected to multi-axial loading. Effects of confining pressure on the stress-strain behavior of EPS geofoam have been investigated in previous studies. Some studies found increases in confining stress lead to corresponding decreases in both modulus and compressive strength. Increasing confining stress has also been reported to result in higher compressive strength. Regardless of the sense and attributed significance of the effects of confinement on EPS geofoam behavior, the implied effects on performance are generally not considered in practice. A series of triaxial compression tests were conducted on EPS geofoams of …

Patterned Biofilm Formation To Investigate Bacteria-Surface Interactions, Huan Gu

Dissertations - ALL

Bacterial adhesion to surfaces and subsequent formation of microcolonies play important roles in biofilm formation, which is a major cause of chronic infections and persistent biofouling. Despite the significance, mechanistic understanding of biofilm formation is still hindered by the structural heterogeneity in biofilms; and effective control of biofilm formation remains challenging. Biofilm formation is a dynamic process that involves numerous changes in bacterial gene and protein expression. These changes are highly sensitive to environmental factors such as surface chemistry, topography, charge, and hydrophobicity. To better control biofilm morphology and specifically investigate the effects of these factors, a platform was developed …

Electrochemical Control Of Bacterial Persister Cells, Tagbo Herman Roland Niepa

Dissertations - ALL

The emergence of antibiotic-resistant bacteria has presented an increasing challenge to infection control. Conventional methods of antibacterial treatment involving high dose of antibiotics or surgical intervention have proven insufficient for eradicating persistent infections, such as those associated with medical implants. It is well recognized that bacterial populations commonly contain a small percentage of phenotypic variants, known as persister cells, which are metabolically inactive and extremely tolerant to antibiotics. When the antibiotic treatment is stopped, surviving persister cells can regenerate the bacterial population with a similar percentage of persister cells. Thus, persistence presents a great challenge to curing chronic infections.

In …

The Effects Of Active Flow Control On High-Speed Jet Flow Physics And Noise, Zachary P. Berger

Dissertations - ALL

The work to be presented focuses on the noise generation of a fully turbulent, compressible jet flow within a large scale anechoic chamber. The investigations are aimed at understanding the complex nature of the jet flow field in an effort to reduce the far-field noise through active flow control and novel reduced-order modeling. The flow field of a highly subsonic, axisymmetric jet with a nozzle diameter of two inches (50.8 mm), is probed through the implementation of two-component particle image velocimetry (PIV) in the streamwise plane, along the jet's centerline. These measurements are coupled with simultaneously sampled near and far-field …

Redesigning The Walker: A More Durable & Dignified Device, Gianna M. Curcio

Honors Capstone Projects - All

Aging and Rehabilitation Engineering is a prominent field with ample room for development of and improvement upon existing options. Surveying city sidewalks, family gatherings, hospital waiting rooms it becomes apparent that the need for mobility aids is abundant. My proposal for Capstone is to redesign the walker from both my mechanical engineering and sculptural perspectives. A walker is meant to improve the quality of life for those who are unable to walk unassisted, but should not come at the cost of the user’s dignity. The way we carry ourselves says a lot about us (i.e. character, will, and level of …

Investigating The Shelf Life Of Benzoyl Peroxide Coated Nozzles For Bone Cement Application, Alysen Leigh Demzik

Honors Capstone Projects - All

Two-solution bone cements (TSBC) were developed to address the limitations of current powder-liquid bone cements, however are characterized by a limited shelf life due to spontaneous free radical polymerization. As a solution to pre-polymerization concerns, the initiator benzoyl peroxide (BPO) was removed from the cement solution and incorporated into a thin film coating within the static mixing nozzle, allowing the BPO to integrate with the TSBC as it is mixed for use. Only short-term storage of BPO-coated nozzles and the subsequent effects on bone cement properties is known. The goal of this study was to investigate the effects of time, …

Investigation Of Boiling Performance Of Graphene-Coated Surfaces, Daniel C. Stack

Honors Capstone Projects - All

In this Capstone Project, I sought to investigate the boiling performance of graphene-coated surfaces. Boiling was accomplished in a pool boiling chamber, with samples of graphene-coating SiO₂ wafers. I developed a procedure for graphene transfer for sample fabrication. Samples were prepared with graphene grown on copper substrates by chemical vapor deposition (CVD). Graphene was transferred from copper substrates to SiO­₂ wafers by a thermal release transfer tape. Copper was etched away from the tape-graphene combination by ferric chloride, and the tape was peeled away after heating, leaving graphene on the SiO₂ substrate. Contact angles were measured to …

Effect Of Particle Shape And Size On Compressibility Behavior Of Dredged Sediment In A Geotextile Tube Dewatering Application, Louis Lafata

Honors Capstone Projects - All

Each year, more than 250 million cubic yards of sediment need to be dredged from U.S. ports, harbors and waterways to maintain navigability. This is accomplished by dredging, the process of excavating submerged sediment by means of scooping or suction. Dredged sediments have low solids content, typically between 10% and 20% for hydraulic dredging. Geotextile tubes are one of many methods utilized to dewater these sediments, which is a process of removing water from sediment that contains low percent solids. Understanding the engineering behavior of slurries inside geotextile tubes is critical for the evaluation of the properties of the dewatered …

Optimum Path Planning For An Impaired Aircraft, Suzannah Bailey

Honors Capstone Projects - All

Proportionally speaking, it is safer to travel by plane than any other form of transportation. However, in some parts of the world such as Africa, the lack of updated aircraft, instability within the region, and inexperience of flight crews contribute to a higher rate of aircraft incidents and accidents. This capstone combines elements from aerospace engineering, as well as international relations to create a program to mitigate these risks.

This new algorithm, the Bailey Algorithm, is very different from the commonly used Dijkstra Algorithm. Unlike Dijkstra, the Bailey Algorithm not only incorporates the distance traveled between cities, but it also …

Probing Cell Membrane And Biofilm Extracellular Matrix Interactions With Tumor Necrosis Factor-Alpha And Interleukin-6 Through Molecular Dynamics Simulations Using A Detailed Chemical Description, Stephen Desalvo

Honors Capstone Projects - All

Bacterial biofilms are a major cause of persistent infections and diseases with known antibiotic and host immune defense resistances. The interaction of signaling factors, namely small cytokines, with the biofilm and host cell is considered vital to the survival of bacterial biofilms. In this study, molecular dynamics (MD) simulations are performed using coarse-grained biomolecular systems to provide significant insight into medical therapeutic advancements in treating persistent and chronic infections. Specifically, MD simulations of the interaction between signaling factors tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) with a model biofilm matrix with detailed description were performed. Additional simulations were used to …

A Study Of Ciliary Beating In Chlamydomonas, Xin Li

Honors Capstone Projects - All

The goal of this research is to understand how a unicellular green alga, Chlamydomonas-reinhardtii, responds to red light (670nm) and sound waves, by monitoring the beating frequency of its two cilia, which control cell motility. Ciliary beating frequency (BF) is proportional to the production of ATP, mainly generated by photosynthesis. A photosynthesis inhibitor, 3-(3-, 4-dichlorophenyl)-1, 1-dimethylurea (DCMU) decreases ATP production by photosynthesis. I used DCMU as a tool to analyze the red light effect on BF.

In the process of studying the effect of red light, I unexpectedly discovered experimental conditions for unstable ciliary beating (as shown in the video). …