Engineering Commons^™

The Structure-Function Relationship Of Pamam Dendrimers As Robust Oil Dispersants, Nicholas K. Geitner, Bo Wang, Rachel E. Andorfer, David A. Ladner, Pu Chen Ke, Feng Ding

Publications

PAMAM dendrimers have recently been investigated as efficient and biocompatible oil dispersants utilizing their encapsulation capacity; however, their high cationic charge density has been shown to be cytotoxic. It is therefore imperative to mitigate cationic charge-induced toxicity and understand the effects of such changes. Presented here is a synergistic experimental and computational approach to examine the effects of varying terminal surface charge on the capacity of dendrimers to disperse model liner, polycyclic aromatic, and hybrid hydrocarbons. Uncharged dendrimers collapse by forming intramolecular hydrogen bonds, which reduce the hosting capability. On the other hand, changing the surface charges from positive to …

Emerging Role Of Photovoltaics For Sustainably Powering Underdeveloped, Emerging, And Developed Economies, Rajendra Singh, Amir A. Asif, Ganesh K. Venayagamoorthy, Akhlesh Lakhtakia, Mahmoud Abdelhamid, Githin F. Alapatt, David A. Ladner

Publications

With the advent of low-cost solar photovoltaic (PV) panels and our ability to generate, store, and use electrical energy locally without the need for long-range transmission, the world is about to witness transformational changes in electricity infrastructures. The use of DC electricity enhances systemwide efficiency. DC microgrids and nanogrids powered by solar PV systems and gigawatt batteries for electricity storage can sustainably power the needs of all human beings equitably and empower every individual. Ultralarge-scale manufacturing of PV systems and batteries, a vertically integrated business model, and a targeted monetary policy of quantitative easing can rapidly power all human activities.

Computational Modeling Of Pathophysiologic Responses To Exercise In Fontan Patients, Ethan Kung, James C. Perry, Christopher Davis, Francesco Migliavacca, Giancarlo Pennati, Alessandro Giardini, Tain-Yen Hsia, Alison Marsden

Publications

Reduced exercise capacity is nearly universal among Fontan patients. Although many factors have emerged as possible contributors, the degree to which each impacts the overall hemodynamics is largely unknown. Computational modeling provides a means to test hypotheses of causes of exercise intolerance via precisely controlled virtual experiments and measurements. We quantified the physiological impacts of commonly encountered, clinically relevant dysfunctions introduced to the exercising Fontan system via a previously developed lumped-parameter model of Fontan exercise. Elevated pulmonary arterial pressure was observed in all cases of dysfunction, correlated with lowered cardiac output (CO), and often mediated by elevated atrial pressure. Pulmonary …

Energy Consumption Reduction Strategies For Plug-In Hybrid Electric Vehicles With Connected Vehicle Technology In An Urban Environment, Parth Bhavsar, Yiming He, Mashrur Chowdhury, Ryan Fries, Andrew Shealy

Publications

Automobile manufacturers have introduced plug-in hybrid electric vehicles (PHEVs) to reduce fossil fuel consumption. This paper details three optimization strategies that can be utilized to further minimize energy consumption of PHEVs through an information exchange between PHEVs and infrastructure agents supported by the connected vehicle technology (CVT). While an earlier research by the authors focused on a freeway scenario, this study developed strategies for an urban scenario in which frequent ‘stop-and-go’ conditions exist. Three strategies were considered in this study based on different types of information availability using CVT; only signal timing information was available in Strategy One, only headway …

Design Of A Sign-Out Process To Improve Surgical Safety, Sumonthip Chompoodang Gmitro

All Theses

According to the World Health Organization (WHO), the surgical safety checklist consists of three parts; sign-in, time-out and sign-out. It has been observed that the sign-out process is the least frequently completed. In this study, because of a concern for the risk of adverse events occurring in the OR, the sign-out process used in a local hospital was redesigned as a web-based application embedded on a desktop computer and on a mobile device. Both web-based platforms were tested along with the current sign-out process on a computer. Eighteen circulating nurses in the operating rooms of Greenville Memorial Hospital used each …

An Examination Of Radionuclide Transport In The Vadose Zone Using Field Lysimeters, Michael Witmer

All Theses

Understanding how radionuclides interact in the subsurface is important for the remediation of contaminated sites, assessment of risk due to radioactive waste disposal, and designing new radioactive waste management strategies. The current understanding of the geochemical behavior of radionuclides in the subsurface and more specifically the vadose zone has been developed through reactive transport modeling supplemented by laboratory experiments. Interactions between radionuclides with the mineral particles and organic matter in the vadose zone can be very complex and while laboratory experiments produce valuable data, few controlled, intermediate scale transport studies have been performed. In order to accurately predict vadose zone …

Development Of An In Vitro System For Evaluation Of Prosthetic Vein Valves, Ross Gorman

All Theses

Chronic venous insufficiency is a chronic disorder where venous pressure is not reduced during exercise. In a healthy individual, the vein valves and muscle pumps of the extremities combine to allow for a reduction in venous pressure during exercise. Consistent high pressure in the leg can lead to disability, pain, and ulcer formation. Typical causes of chronic venous insufficiency are venous reflux and acute venous obstruction. Research is under way to develop a prosthetic vein valve that can easily be implanted with a minimally invasive catheter procedure which addresses chronic venous insufficiency. This thesis discusses development of an in vitro …

Dendritic Polymers As Biocompatible Oil Spill Dispersants: Effectiveness And Mechanisims With Crude Oil, Ying Tu

All Theses

Dendritic polymers have recently been shown to entrap polycyclic aromatic hydrocarbons (PAHs) and other hydrophobic materials. Laboratory results have shown that poly(amidoamine) dendrimers and hyperbranched poly(ethyleneimine) polymers form complexes with linear (hexadecane) and polyaromatic (phenanthrene) hydrocarbons, increasing the dispersion of these model crude oil components. It is thus hypothesized that crude oil can be dispersed using these polymers. Compared with commercial dispersants, dendritic polymers have the potential to be more biocompatible and less toxic. The objective of this research was to gain a fundamental understanding of the interactions of dendritic polymers with crude oil. We used Louisians Sweet Crude oil …

Electrokinetic Instabilities In Ferrofluid Microflows, Dhileep Thanjavur Kumar

All Theses

Lab-on-a-chip devices have been increasingly used in the past two decades for chemical and biomedical analysis. These devices employ the concepts of microfluidics and offer the promise of incorporating multiple laboratory processes onto a single portable chip. Electric field has been often employed in microfluidic devices for the ease of fluid and sample control as well as the convenience of chip integration and interfacing. Flow instabilities can take place when two fluids of unequal electrical properties are pumped through a microchannel under the application of an adequately strong electric field. The study of these electrokinetic instabilities in microfluidic devices is …

Pharmacists' And Patients' Perceptions Of Role Of Pharmacist In Discharge Process, Ravi Teja Vempati

All Theses

The objective of this study was to identify the perceptions of both patients and pharmacists about the pharmacist's role in the hospital discharge process. In order to do this, observations were conducted with the patients and interviews were conducted with both patients and pharmacists. During the interviews, both the patients and pharmacists were asked about the pharmacist's role in the hospital discharge process. The interviews were qualitatively analyzed using the in vivo technique. Four high-level themes emerged from this study: Current role of a pharmacist in the hospital, Ideal role of a pharmacist in the discharge process, Pharmacists' perceptions of …

Space-Capable Long And Thin Continuum Robotic Cable, Manas Milind Tonapi

All Theses

Design of continuum robots, i.e. robots with continuous backbones, has been an active area of research in robotics for minimally invasive surgery, search and rescue, object manipulation, etc. Along the same lines, NASA developed "Tendril", the first long and thin continuum robot of its kind, intended for in-space inspection applications.

The thesis starts with describing and discussing the key disadvantages of the current state of the art mechanical design of "Tendril'' producing undesirable effects during operation. It then includes the design specifics of a novel concept for construction of a next generation long and thin, space-cable, multi-section, continuum cable-like robot, …

Fatigue-Induced Failure In Horizontal-Axis Wind-Turbine (Hawt) Blades And Hawt Drivetrain Gears, Varun Chenna

All Theses

Wind energy is one of the most promising and the fastest growing installed alternative-energy production technologies. In fact, it is anticipated that by 2030, at least 20% of the U.S. energy needs will be met by various onshore and offshore wind-farms [a collection of wind-turbines (converters of wind energy into electrical energy) at the same location]. A majority of wind turbines nowadays fall into the class of the so-called Horizontal Axis Wind Turbines (HAWTs). Turbine blades and the gearbox are perhaps the most critical components/subsystems in the present designs of HAWTs. The combination of high failure rates (particularly those associated …

Adsorption Of Halogenated Aliphatic Contaminants By Graphene Nanomaterials: Comparison With Carbon Nanotubes And Granular Activated Carbons, Yang Zhou

All Theses

Graphene nanomaterials are two-dimensional single layer sp2 hybridized carbon atoms densely packed in a hexagonal honeycomb lattice and can be visualized as basic building blocks for fullerenes, carbon nanotubes (CNTs), and graphite. In addition, they are hydrophobic nanomaterials and possess a large specific surface area (SSA), thus they have been evaluated as promising adsorbents to remove synthetic organic compounds (SOCs) from water. As with granular activated carbons (GACs) and CNTs, adsorption behavior of SOCs on graphene depends on the physicochemical properties of the adsorbents (e.g., specific surface area, pore size distribution and surface chemistry), SOCs (e.g., hydrophobicity, molecular size and …

A Load-Based Approach To Forming A Connected Dominating Set For An Ad Hoc Network, Raihan Hazarika

All Theses

Efficient routing in mobile ad hoc networks (MANETs) is highly desired and connected dominating sets (CDS) have been gaining significant popularity in this regard. The CDS based approach reduces the search for a minimum cost path between a pair of source and destination terminals to the set of terminals forming the backbone network. Researchers over the years have developed numerous distributed and localized algorithms for constructing CDSs which minimize the number of terminals forming the backbone or which provide multiple node-disjoint paths between each pair of terminals. However none of this research focuses on minimizing the load at the bottleneck …

Design And Demonstration Of A Two-Dimentional Test Bed For Uav Controller Evaluation, Ran Huang

All Theses

A three degree-of-freedom (DOF) planar test bed for Unmanned Aerial Vehicle (UAV) controller evaluation was built. The test-bed consists of an instrumented tether and an experimental twin-rotor, planar UAV mounted with a one DOF manipulator mounted below the UAV body. The tether was constructed to constrain the UAV under test to motion on the surface of a sphere. Experiments can be conducted through the tether, approximating motion in a vertical plane by a UAV under test. The tether provides the means to measure the position and attitude of the UAV under test. The experimental twin-rotor UAV and one-link on-board manipulator, …

The Use Of Oxidants For Ndma Precursor Deactivation In Wastewater Treatment, Jaclyn Lauer

All Theses

Water treatment plants in the United States (US) have been switching from chlorination to chloramination in the search for a disinfection process to reduce formation of regulated disinfection by-products (DBPs). Unfortunately, the trade-off is the formation of N-nitrosamines. N-nitrosodimethylamine (NDMA) is the most commonly detected N-nitrosamine in US distribution systems. In the Integrated Risk Information Service (IRIS) database of the United States Environmental Protection Agency (USEPA), NDMA has been identified to have an estimated 10-6 lifetime cancer risk level at a concentration of 0.7 ng/L in drinking water. N-nitrosamines are currently not regulated by the USEPA; however, are listed on …

High-Productivity Membrane Adsorbers: Polymer Surface-Modification Studies For Ion-Exchange And Affinity Bioseparations, Heather Chenette

All Dissertations

This Dissertation centers on the surface-modification of macroporous membranes to make them selective adsorbers for different proteins, and the analysis of the performance of these membranes relative to existing technology. Traditional chromatographic separations for the isolation and purification of proteins implement a column packed with resin beads or gel media that contain specific binding ligands on their exposed surface area. The productivity of this process is balanced by the effective use of the binding sites within the column and the speed at which the separation can take place, in addition to the need to maintain sufficient protein purity and bioactivity. …

Platform Technologies To Advance Clinically Relevant Tissue Engineered Heart Valve Products, Leslie Neil Sierad

All Dissertations

Diseased heart valves are commonly replaced by mechanical, bioprosthetic, or allograft heart valves. These replacements provide major improvements in cardiac function and quality of life, but have significant limitations and eventually require surgical replacement within 15-20 years. These risks are particularly prominent in pediatric patients and young adults. The field of tissue engineering and regenerative medicine, which combines scaffolds and cells, holds great promise in developing living replacement heart valves that would self-repair and grow in size along with the growing children.

The long-term goal of this project is to generate living, tissue-engineered heart valves from biological scaffolds and autologous …

A Verification Of Steady State Discontinuous Solutions Using The Method Of Manufactured Solutions For Finite Volume Computational Fluid Dynamic Codes, Benjamin Grier

All Dissertations

When applying the method of manufactured solutions (MMS) on computational fluid dynamic (CFD) software, it is traditionally a requirement that all solutions be continuous on the computational domain. This stipulation is limiting for the verification and validation of CFD solutions where discontinuities are frequent. This work details the development of a discontinuous MMS method for finite volume codes. The CFD code used throughout this research is a cell centered, finite volume, 1st order, Eulerian scheme within the software AVUS (Air Vehicles Unstructured Solver) which is combined with uniform structured grids. This code is used as a representative testing platform with …

Decentralized Water Systems For Sustainable And Reliable Supply, Suraj Goverdhanam

All Theses

The water industry is under enormous pressure to provide potable water in circumstances of increasing demands due to population growth, lifestyle change of people and depleting freshwater resources. Deteriorating infrastructure makes the task of meeting the human water consumption needs even more challenging. Distributed water supply systems are currently pursued as a sustainable alternative in arid regions of US to exploit the potential of water reclamation at community or district level to reduce the dependence on freshwater resources. An extension of such a distributed water supply alternative is a complete decentralized supply, which requires on-site water reclamation. The intention of …

An Experimental Investigation Towards Improvement Of Thermoelectric Properties Of Strontium Titanate Ceramics, Arash Mehdizadeh Dehkordi

All Dissertations

The direct energy conversion between heat and electricity based on thermoelectric effects is a topic of long-standing interest in condensed matter materials science. Experimental and theoretical investigations in order to understand the mechanisms involved and to improve the materials properties and conversion efficiency have been ongoing for more than half a century. While significant achievements have been accomplished in improving the properties of conventional heavy element based materials (such as Bi$_2$Te$_3$ and PbTe) as well as the discovery of new materials systems for the close-to-room temperature and intermediate temperatures, high-temperature applications of thermoelectrics is still limited to one materials system, …

Development Of Poly(Lactic Acid)-Poly(Ethylene Glycol) Nanoparticles For The Delivery Of Non- Toxic Drug In Combination Therapy For The Treatment Of Glioblastoma And Neuroblastoma, Olivia Grace Decroes

All Theses

Glioblastoma and neuroblastoma are both solid-form tumors. Glioblastomas primarily reside in the brain, while neuroblastomas are found in the sympathetic nervous system. Both glioblastoma and neuroblastoma re classified as orphan diseases, which affect less than 200,000 individuals a year. Over the course of 5 years, 40% of patients diagnosed with neuroblastomas and only 6% of patients diagnosed will glioblastomas will be living.^73,74. Glioblastoma and neuroblastoma tumors possess a gene known as MGMT. MGMT is used by tumors as a DNA repair mechanism, which increases the likelihood these tumors will become resistant to traditional drug therapies.^28,37 Other pathways, …

Spatial And Temporal Analysis Of Land Cover Change, Sedimentation And Water Quality In The Lake Issaqueena Watershed, South Carolina, Cassie Pilgrim

All Theses

Soil erosion and increased sediment yields within a watershed lead to impaired water quality, decreased availability of wildlife habitat and reduced recreational opportunities. While some sedimentation occurs naturally within a water system, most erosion processes are the result of anthropogenic activities across a landscape, namely changes in land use and land cover (LULC). This study was conducted to determine temporal and spatial sedimentation trends in the Lake Issaquena watershed using sonar logging equipment, geographic information systems (GIS) and limited hydrologic data from the Soil Conservation Service (1941 and 1949). Sediment deposition was analyzed in relation to several key factors that …

Potential Effects Of Geologic Storage Of Co2 On Surface Water And Shallow Groundwater, Shuangshuang Xie

All Theses

ABSTRACT Storage of supercritical phase CO2 in deep saline aquifers is being considered to reduce greenhouse gases in the atmosphere, and this process is expected to increase the pressure in these deep aquifers. One potential consequence of pressurization is an increase in the upward flux of saline water. Saline groundwater occurs naturally at shallow depths in many sedimentary basins, so an upward flux of solutes could degrade the quality of aquifers, and threaten aquatic ecosystems where groundwater discharge is important. The objective of this research is to evaluate the impacts associated with increasing the upward flux of saline water as …

Synthesis Of Silicon Carbide Fibers From Polycarbosilane By Electrospinning Method, Yuan Yue

All Theses

Silicon carbide (SiC) is widely used in many fields due to its unique properties. Bulk SiC normally has a flexural strength of 500 - 550 MPa, a Vickers hardness of ~27 GPa, a Young's modulus of 380 - 430 GPa, and a thermal conductivity of approximately 120 W/mK. SiC fibers are of great interest since they are the good candidates for reinforcing ceramic matrix composites (CMCs) because of the weavability and high temperature strength of about two to three GPa at about 1000 °C. Silicon carbide fibers have been synthesized from polycarbosilane (PCS) with ~25 μm diameter using the melt-spinning …

Adhesion Of Liquids To Porous Materials And Fibers, Artem Trofimov

All Theses

This research is centered on the analysis of adhesion properties of porous materials and fibers of elliptical shapes. Composites are a unique class of materials having properties, which could not be achieved by either of the constituent materials alone. Composites with porous filler are put into service in buildings, roads, bridges, etc. Fiber-reinforced composites are actively involved in flight vehicles, automobiles, boats, and dozens of other products. In the first part of this study we developed a procedure for evaluation of adhesion of liquids to porous solids, where water, hexadecane and asphalt binder and different rocks were studied to illustrate …

The Impact Of Block Scheduling And Release Time On Operating Room Efficiency, Rebecca Weiss

All Theses

Planning for sufficient surgical capacity at a hospital requires that many tactical and operational decisions be made before the day of surgery. Typically, blocks of time in operating rooms (ORs) are assigned and specific surgical cases are placed in rooms. The hospital monitors utilization to determine the schedule's effectiveness in balancing the risk of overtime with idle time. In this thesis, we will examine how adjusting schedule risk ratios and penalty values, and providing shared, open posting time affected the hospital's ability to identify an efficient but high quality and low cost block schedule. The proposed schedules were tested by …

Effects Of Natural Organic Matter On Contaminant Removal By Superfine Powdered Activated Carbon Coupled With Microfiltration Membranes, Mengfei Li

All Theses

Hybrid activated carbon/membrane systems are used in drinking water treatment for their significant capability of removing synthetic organic contaminants (SOCs) or taste-and-odor compounds along with particles. Preliminary data showed that decreasing the carbon particle size and creating superfine powdered activated carbon (S-PAC) removed phenanthrene and atrazine better than adsorbents with larger particle size in the presence of competitive adsorbents like natural organic matter (NOM). NOM is present in all natural water from degradation of terrestrial biomass which leaches from soil into a water source. Water treatment facilities target the removal of NOM because they are precursors to disinfection by-products formed …

Investigating The Non-Adoption Of Electronic Health Records In Primary Care, Saravanan Ramdoss

All Theses

The objective of this study was to investigate the underlying reasons behind primary care centers in the United States not implementing an Electronic Health Record system in spite of looming penalties under the Health Information Technology for Economic and Clinical Health (HITECH) Act. In order to do this, survey was developed and distributed among healthcare providers who have not yet implemented an EHR system at their practice. The questions for the survey were developed after conducting a literature review of the barriers to EHR implementation. In this review, six themes emerged: technical, cost, productivity, change process, privacy and time. These …

Theoretical And Computational Design Analysis Of A Harmonica Type Aeroelastic Energy Harvester, Songkai Wang

All Theses

A wind energy harvester inspired by music playing harmonicas was proposed for micro-power generation. The energy harvester utilizes flow-excited self-sustained oscillations of a piezoelectric cantilever beam mounted in a wind pipe to generate electric power. The dependence of the energy harvester's power generation performance on a set of the design parameters such as the chamber volume, aperture width and beam dimensions has been studied previously. However, the performance of the nonlinear multi-physics system with two-way fluid structure coupling also depends on other design parameters such as the geometry of the oscillatory beam, the beam mounting configuration and the geometry of …