Engineering Commons^™

The Proposal For Implementation Of Controlled Power Rectifier (3000/4000kw) In Mta New York City Transit (Mta-Nyct), Md Aminul Islam

Dissertations and Theses

The MTA New York City Transit (MTA-NYCT) will require a robust and reconfigurable power system capable of supplying high power in order to be able to provide services based on for cased future forecast growth of the city population. A critical component in such a system is the Phase Controlled Rectifier. As such, the issues associated with the inclusion of a power electronics rectifier need to be addressed. These issues include input Alternating Current (AC) interface requirements, the output Direct Current (DC) load profile, and overall stability in the output voltage for Train car loads.

Understanding these issues, providing possible …

A Study On The Heavy Crude Oil Viscosity Reduction With The Dissolution Of Nitrogen And Carbon Dioxide, Abdurahman Ajumobi

Dissertations and Theses

World's energy challenges would be greatly improved upon if half of the world's heavy oil and extra heavy oil could be made to ow in pipelines. Viscosity reduction of heavy oils is the key to solving this problem. In this study, aside from injecting pure nitrogen and pure carbon dioxide separately into the oil, two different compositions of the mixture of the two gases were also injected. In the first mixture, varied quantities of the two gases were used; 62:5%, 82:2% and 86:4% of the mixture was nitrogen while 37:5%, 17:8% and 13:6% was carbon dioxide at total test pressures …

The Synthesis And Characterization Of Dual-Modified Carboxymethylcellulose For Bioadhesive Applications, Fabrice Bernard

Dissertations and Theses

Reparative medical techniques, in conjunction with existing and emerging tissue adherents and sealants, offer practicing physicians a wide variety of tools to improve the functionality, performance, and safety of surgical interventions. Carboxymethylcellulose (CMC) is a plant-derived polymer that is cytocompatible, biocompatible, biodegradable, and inexpensive. The need for a non-toxic but strongly adherent material motivated the development of an injectable bioadhesive system containing CMC modified with functional methacrylate and aldehyde groups that could potentially be used as an annulus fibrosus sealant or as a supplement to existing wound closure materials. After modification, the polymer was characterized via NMR spectroscopy, Schiff’s base …

Exploration Of The Mechanical Properties Of Both Ridged And Inflated Drop Stitch Fabric Material, Roberto Felicissimo

Dissertations and Theses

The mechanical properties of drop stitch fabric materials in tension and shear has been investigated for use in designing structural applications such as ship construction, modular buildings, inflatable structures, aquatic vehicles, sporting goods and temporary field equipment installations. The goal of testing is to improve the understanding of the mechanical properties, which can aid in application development for structural deployments using these unique materials. The benefits of using rigid drop stitch fabric panels in ship and building construction are their light weight and rigidity. The epoxy resin infused fabric is corrosion and degradation resistant while providing a more robust resistance …

Assessment Of Injection Behavior Of Commercially-Available Bone Bsms For Subchondroplasty Procedures, Dinely A. Colon

Dissertations and Theses

Subchondroplasty is a procedure that utilized bone substitutes materials (BSMs) or bone cement to correct bone defects in the subchondral bone. The two main materials used to compose BSMs are poly-methyl-methacrylate (PMMA) and calcium phosphate cement (CaP). Currently, there is no optimal bone material substitute in the market that can provide both the adequate mechanical support and the right viscosity to reach the affected area in the subchondral bone. In addition, there is also no established parameter for their proper use, based on the defect size and location. PMMA possesses comparable mechanical properties to bone (i.e. 96 MPa in compressive …

Morphology Of Brain Sulci Trabeculae And Its Effect On Brain During Impacts, Sharlin Anwar

Dissertations and Theses

Traumatic brain injury (TBI) is an intracranial injury caused by direct contact or non-contact head impacts to the brain. TBI is a major problem that accounts for high incidents of hospitalizations each year. Thus, it is important to understand and predict the occurrence of TBI in an impact. It has been shown that the subarachnoid space (SAS) trabeculae play an important role in damping the effect of an impact, thus reducing the injuries. However, the influence of sulci parameters and the sulci trabeculae in TBI due to impact is unexplored. Studies have shown that inclusion of sulci in brain models …

Performance Of Self-Excited Energy Harvesters With Tip Bodies Of Non-Circular Cross Section Shapes, Joan Manuel Gomez

Dissertations and Theses

An experimental study on the performance of self-excited energy harvesters with non-circular tip body shapes has been performed. The two tip body shapes analyzed correspond to a half cylinder and a square cross section. Experiments are carried out in the wind tunnel to record the voltage output of the harvesters at different free stream velocities. The presence of the aeroelastic galloping instability was detected by the behavior of the transversal tip displacement of the harvester as well as the coupling of the motion and shedding frequency from the bluff body. The effect of tip mass, free stream turbulence, tip body …

Calibration And Validation Of An In Vitro Ultrasound Device To Deliver Targeted Thermal Enhancement Of Hmsc Osteogenesis, Dionne Dawkins

Dissertations and Theses

Osteoarthritis (OA) is a disease that affects millions of people annually, often the elderly, and limits their physical abilities. Current methods of treating OA are often very invasive, and expensive, costing the Medicare system billions of dollars annually. A minimally invasive therapy that can be localized to the affected area that provides both relief and a short recovery time is optimal for treating the disease. For targeted therapy and clinical use, therapeutic ultrasound in the 0.7 MHz to 3 MHz frequency range can provide relief and is convenient, portable and localized. Low-intensity pulsed ultrasound (LIPUS) has been proven in clinical …

Chemotaxis Of Central Nervous System-Derived Tumor Cells Within Controlled Microenvironments, Jennifer Rico Varela

Dissertations and Theses

Medulloblastoma (MB) is a malignant pediatric brain tumor known for its aggressive metastatic potential. Despite the well-documented migration of MB cells to other parts of the brain and spinal column, MB chemotaxis is poorly understood. Herein, we examined the in vitro migratory and cellular responses of MB-derived cells to external signaling of Epidermal Growth Factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF-BB), and the stromal cell-derived factors 1-alpha (SDF-1). Experiments utilized transwell assays and immunocytochemistry to identify receptor activation in MB migration, and used a microfluidic platform to examine directionality, trajectory, and gradient- dependence of motile cells. Data …

Development Of Super Hydrophobic Surfaces Using Silica Nanoparticles, Muhammad Salman Saleem

Dissertations and Theses

The development of surfaces that have high water contact angles and hysteresis has always been of great importance in industrial applications. Various methods and techniques have been introduced to fabricate surfaces at nano-scale to support super hydrophobicity. Some of these techniques are expensive, some are very complex, most can be used for selective materials and substrate and some form surfaces with very poor wear resistance. This document represents a systematic study on fabrication of super hydrophobic surfaces on glass substrate (SiO2) using the functionalized silica (SiO2) nano particles. SU8, Polydimethylsiloxane (PDMS) and Methyphenyl Resin SR355 polymer are being used as …

An Experimental Study Of Subcooled Flow Boiling At Elevated Pressure In An Annular Flow Channel, Pervej Rahman

Dissertations and Theses

An experimental setup was developed to study the region of subcooled flow boiling. Multiple studies were carried out to investigate the effects of liquid velocity, pressure, and temperature on the boiling heat transfer of subcooled fluid flowing through a heated annular channel. Water was used as the working fluid and principle of Ohmic heating was used to raise water temperature. The system pressure, heat flux, & mass flux ranged from 101 to 912 kPa, 19 to 155 kW/m2, and 83 to 332 kg/m2-s, respectively. This report contains boiling curves, heat transfer coefficients of various studies and a description of the …