Engineering Commons^™

Formation Of Molecularly Imprinted Polymer Matrices Using, William Erwin

Chemical Engineering Undergraduate Honors Theses

This study serves as a proof of concept that a poly(acrylonitrile-co-acrylic acid) may be used to form an chiral selective polymer membrane for discrimination of L-tryptophan from racemic tryptophan. Due to the unavailability of necessary equipment, a polymer membrane was not tested, rather, two experiments were run in conjunction; (1) A membrane of L-tryptophan imprinted P(AN-co-AA) was cast and tested on a scanning electron microscope to determine the membrane density, and (2) Imprinted polymer was ground and tested for absorption of L-Tryptophan by finding circular dichroism and concentration for different samples. It was found that it is feasible that P(AN-co-AA) …

Green Ro Pretreatment, Elizabeth Fullerton

Chemical Engineering Undergraduate Honors Theses

The use of sea water desalination to produce potable water for maritime vessels is essential for eliminating storage of potable water. Reverse osmosis (RO) is the technology of choice for desalination purposes; however, raw seawater must undergo pretreatment to avoid rapid fouling and plugging of RO membranes and modules. Current pretreatment technology is effective in the open ocean but in coastal regions involves frequent replacement of filter cartridges and increased maintenance costs. The standard pretreatment process consists of 20 μm cartridge filters and 3 μm cartridge filters in series. Several technologies were considered as options for improving the current pretreatment …

Microhydroelectric Power Generation, Aaron Hughes

Chemical Engineering Undergraduate Honors Theses

A major industrial water user in New Mexico discharges approximately 3.8 million gal of wastewater per day. The topology of the site provides an elevation difference of about 150 ft between the plant site and the entrance to the municipal sewage line; this flow and elevation difference is sufficient to produce about 40 kW of electrical power using a water turbine/electrical generator set to extract power from the flowing stream. This report includes designs and economic analyses for two distinct cases. One case is based on the written premises of the task; whereas, a second case is based on a …

Plasma-Assisted Molecular Beam Epitaxial Growth Of Indium Nitride For Future Device Fabrication, Steven Paul Minor

Graduate Theses and Dissertations

The need for energy conservation has heightened the search for new materials that can reduce energy consumption or produce energy by the means of photovoltaic cells. III-nitride alloys show promise for these applications due to their generally good transport properties and ability to withstand high power applications. Along with these, this family of semiconductor alloys has a direct bandgap energy range (0.7-6.2 eV) which spans the entire visible spectrum and encompasses a large portion of the available solar spectrum. Of the three root III-nitride semiconductors, AlN, GaN, and InN, InN has only recently become attainable epitaxially with qualities good enough …

Aptamer-Based Spr Biosensor For Detection Of Avian Influenza Virus, Hua Bai

Graduate Theses and Dissertations

Rapid and specific detection of avian influenza (AI) virus is urgently needed with the concerns over the outbreaks of highly pathogenic H5N1 avian influenza in animal and human infection. Aptamers are artificial oligonucleic acid that can specifically bind to target molecules. They show comparable affinity for target virus and better thermal stability than monoclonal antibodies. Those advantages make aptamers promising candidates in diagnostic and detection applications. The goal of this research was to use DNA&ndashaptamer as the specific recognition element in a portable surface plasmon resonance (SPR) biosensor for detection of AI H5N1 virus in poultry.

A SPR biosensor was …

Investigation Of Negative Differential Resistance Phenomena In Quantum Well Heterostructures, Nazariy Andrushchak

Graduate Theses and Dissertations

Increasing interest in entirely new possibilities for quantum mechanical description of carriers transport is becoming more evident with the developing advancements in epitaxial growth technique. Consequently, molecular beam epitaxy (MBE) technique is considered to be the most precise technique that allows the growth of ultra-thin layers of different compositions.

Those structures can be designed to investigate the wave-nature of carriers, which broadens the possibilities in device design and fabrication for a specific area. In this thesis the fundamental study of the real space charge transfer (RST) mechanism that took place in quantum well heterostructures and led to the negative differential …

Bond Performance Of Lightweight Self-Consolidating Concrete, Michael Howland

Civil Engineering Undergraduate Honors Theses

Self-consolidating concrete (SCC) allows for the placement of concrete without consolidation. The use of lightweight (LW) concrete reduces dead loads and lowers transportation costs. LWSCC is a recent combination of the two types of concrete; therefore there is little information on the performance of prestressed members cast with LWSCC. This project examines transfer length of LWSCC beams and compares the measured values to control-mixture members cast with normal weight SCC. Eight prestressed beams were cast. Of the eight, four conventional were cast with SCC and the remaining four with LWSCC. The lightweight mixtures contained expanded clay aggregate and had an …

Micro Hydro-Electric Power Generation, Travis Rose

Chemical Engineering Undergraduate Honors Theses

A major industrial water user in New Mexico discharges approximately 3.8 million gal of wastewater per day. The topology of the site provides an elevation difference of about 150 ft between the plant site and the entrance to the municipal sewage line; this flow and elevation difference is sufficient to produce about 40 kW of electrical power using a water turbine/electrical generator set to extract power from the flowing stream. This report includes designs and economic analyses for two distinct cases. One case is based on the written premises of the task; whereas, a second case is based on a …

Balloonsat Based Investigation Of Atmospheric Electric Potential For Sustainable Energy Production, Jason Haynes

Mechanical Engineering Undergraduate Honors Theses

The Earth is daily bombarded with cosmic radiation which delivers ions to the atmosphere and creates new ions via the collision of the incoming particles with the atmospheric particles, stripping them of electrons. Generally, this process results in a positively charged atmosphere and a negatively charged surface of the Earth. This process causes an electrical current which flows throughout the atmosphere and into the Earth's surface and comprises a system referred to as "the global atmospheric electrical circuit." This electrical current is very small at the surface of the Earth, on the order of 161'-12 amperes per square meter. The …

Hollow Fiber Membranes In Increased Algae Growth For Biobutanol Production, Allison Mcatee

Chemical Engineering Undergraduate Honors Theses

Algae are a unique and remarkable species of plant that is capable of thriving on land deemed useless for the cultivation of food crops. They also breathe in the harmful greenhouse gas, carbon dioxide. As the fastest living organism to complete a life cycle, algae is the single most effective user of carbon dioxide in the world thus making it an important ally for diminishing the threat of global warming. Furthermore, algae are comprised of high concentrations of lipids, rendering it an appealing option for use in biodiesel production, specifically butanol. Increasing the algae’s supply of carbon dioxide gas causes …

Using Capillary Electrophoresis To Detect Amyloid Protein Aggregation, Jennifer Kurtz

Chemical Engineering Undergraduate Honors Theses

Alzheimer’s disease (AD) is the leading cause of dementia accounting for ½ to ¾ of all cases. AD is characterized by a progressive loss of cognitive function over a span of 10 years, ultimately ending in death. The main possible cause of AD being researched is the formation of soluble, oligomer amyloids. Amyloids are proteins that misfold and aggregate in the brain causing potent neurotoxic effects on neurons in the brain. Microchip electrophoresis and capillary electrophoresis are two potential methods of determining the level of amyloid aggregation. In order to detect at physiological concentrations, covalent dyes must be used to …

Sweetgum Bark: Extraction, Purification, And Determination Of Antioxidant Activity, Shiloh Hurd

Biological and Agricultural Engineering Undergraduate Honors Theses

Sweetgum (Liquidambar styraciflua L.) is a native tree species that grows as a volunteer in the understory of managed pine forests in Arkansas. Sweetgum, as well as other volunteer species, must be removed before the pines can be harvested. Sweetgum wood can be converted to hemicellulosic and cellulosic sugars by dilute acid pretreatment and enzymatic hydrolysis. These wood-derived sugars can then be fermented into cellulosic ethanol. Usually, the bark is not deconstructed into sugars, but transformed into thermal energy via a combustion process. Interestingly, the bark of the sweetgum contains value-added products that could be recovered prior to thermal processing. …

Study Of The Anisotropic Frictional And Deformation Behavior Of Surfaces Textured With Silvr Nanorods, Thomas Ivanoff

Mechanical Engineering Undergraduate Honors Theses

Friction is one of the most common and influential mechanical interactions of two structures on both the macroscopic scale and especially the microscopic scale. On the microscopic scale, friction becomes the prime component of mechanical forces exerted on devices. Frictional anisotropy is an interesting characteristic of certain materials and can be used to control frictional properties in various applications. In this study, we measured the anisotropic frictional behavior of two silver (Ag) thin films: a continuous film and a thin film consisting of tilted nanorods angled at an average angle of 70o to the surface normal. Scratches, eight microns in …

Experimental Study Of Novel Materials And Module For Cryogenic (4k) Superconducting Multi-Chip Modules, Ranjith John

Graduate Theses and Dissertations

The objectives of this proposal are to understand the science and technology of interfaces in the packaging of superconducting electronic (SCE) multichip modules (MCMs) at 4 K. The thermal management issue of the current SCE-MCMs was examined and the package assembly was optimized. A novel thermally conducting and electrically insulating nano-engineered polymer was developed for the thermal management of SCE-MCMs for 4 K cryogenic packaging. Finally, the nano-engineered polymer was integrated as underfill in a SCE-MCM and the thermal and electrical performance of SCE-MCM was demonstrated at 4 K.

Niobium based superconducting electronics (SCE) are the fastest known digital logic …

Mathematical Modeling Of Fluid Spills In Hydraulically Fractured Well Sites, Oluwafemi Michael Taiwo

Graduate Theses and Dissertations

Improved drilling technology and favorable energy prices have contributed to the rapid pace at which the exploitation of unconventional natural gas is taking place across the United States. As a natural gas well is being drilled, reserve pits are constructed to hold the drilling fluids and other materials returned from the drilling process. These reserve pits can fail, and when they do, plant and animal life of the surrounding area may be adversely affected. This project develops a screening tool for a suitable location for a reserve pit. This work will be a critical piece of the Infrastructure Placement Analysis …

Silicon Germanium Sram And Rom Designs For Wide Temperature Range Space Applications, Matthew Barlow

Graduate Theses and Dissertations

This thesis presents a design flow from specifications and feature requirements to embeddable blocks of SRAM and ROM designs from 64 bytes to 1 kilobyte that are suitable for lunar environments. The design uses the IBM SiGe 5AM BiCMOS 0.5 micron process for a synchronous memory system capable of operating at a clock frequency of 25 MHz. Radiation mitigation techniques are discussed and implemented to harden the design against total ionizing dose (TID), single-event upset (SEU), and single-event latch-up (SEL). The memory arrays are also designed to operate over the wide temperature range of -180 °C to 125 °C. Design, …

Electrospun Polycaprolactone Nanofiber Scaffolds For Tissue Engineering, Andreas Haukas

Graduate Theses and Dissertations

Stem cell and tissue engineering offer us with a unique opportunity to research and develop new therapies for treating various diseases that are otherwise incurable using traditional medicines. However, development of these new therapies replies upon the establishment of in vitro cell culture and differentiation systems that mimic in vivo microenvironments required for cell-cell and cell-ECM interaction. The development of these cell culture systems depends upon the identification of appropriate biomaterials and cell sources. Biomaterials should be carefully selected and fabricated into scaffolds for supporting cell growth and differentiation. In this study, we explored the fabrication of 3D electrospun nanofiber …

Development Of A Microfluidic Device Coupled To Microdialysis Sampling For The Pre-Concentration Of Cytokines, Randy Francisco Espinal Cabrera

Graduate Theses and Dissertations

A proof-of-concept microfluidic device combined with heparin-immobilized magnetic beads was created to concentrate cytokine proteins collected from microdialysis samples. Cytokines are known to be related to several diseases such as cancer, and Parkinson's diseases, so to be able to develop more effective diseases treatments their interactions have to be well understood. Amine-functionalized polystyrene and carboxyl-functionalized magnetic microspheres of ~6.0 ìm in diameter were used to immobilize heparin. The amount of heparin immobilized on polystyrene beads was 5.82 x 10-8 ± 0.36 x 10-8 M per 1.0 x 106 beads and for magnetic beads was 0.64 x 10-8 ± 0.01 x …

Investigation Of Slopes And Deflections Of A Stepped Beam Using A Global Formula For Ey'', Raymond Salmon

Mechanical Engineering Undergraduate Honors Theses

The purpose of this paper is to investigate the slopes and deflections of a beam with two steps (i.e. a beam with a change of cross section) by use of a global formula. In order to understand the derivation and use of this formula, a brief review of singularity functions is provided. The global formula simplifies the solution method for stepped beams (eliminating the need for dividing the beam into segments and solving multiple simultaneous equations). It has been found that, when loaded on the first beam segment, the global formula allows for quick calculations of slope and deflection of …

Comparative Fatigue Analysis Of Metals And Polymers For Engineering Applications, Monica Jones

Mechanical Engineering Undergraduate Honors Theses

Rapid prototype polymers are becoming increasingly popular for engineering applications, particularly during the design phase as a quick check for size and fit; however they are not currently widely-used for load-bearing applications. Current research at the University of Arkansas Department of Mechanical Engineering focused on rapid prototyped polymers by doing cyclical tensile testing. The results were analyzed for strain energy and fatigue data. When cycling at lower percentages of ultimate stress, unusual strain energy patterns were observed. This research details testing of metals in order to compare strain energy patterns to those of the rapid prototype polymers.

Enhanced Tribological Properties Of Surfaces Patterned With Dlc/Su8 Microstructures, Luke Osborn

Mechanical Engineering Undergraduate Honors Theses

Textured surfaces can reduce friction due to decreased contact area between two surfaces, and could therefore increase the reliability of micro-electro-mechanical systems (MEMS). The problem with some microtextures is their inability to withstand significant amounts of wear, often deforming or breaking, thus limiting their potential uses and overall effectiveness. In this study, connected and isolated SU8 microstructures with and without diamond-like coating (DLC) were designed to investigate the effects of these microstructures on the tribological performance of a surface. Friction studies were conducted using a tribometer, while surface topography and wear were characterized by scanning electron microscopy (SEM), optical microscope, …

Full Depth Reclamation: Compaction And Moisture Content, Alexander Jackson

Civil Engineering Undergraduate Honors Theses

Many times a road will fail and will be in need of both a structural increase and a repair. Full Depth Reclamation (FDR) is a road rehabilitation technique able to offer both. This method also has a lower total cost and significantly lower material usage than traditional overlaying repair methods. FDR is a road repair method which mills up the current road down into the subgrade, and then stabilizes and compacts the milled material. This is also useful for correcting deeper problems in the road structure which are not addressed by traditional methods. In this study, three different suggestions of …

Formation Of Embryoid Bodies From Human Embryonic Stem Cells In Defined Medium, Ashley Kiene

Biological and Agricultural Engineering Undergraduate Honors Theses

Embryonic stem cells have the characteristic of self-renewal and the ability to differentiate into tissues from all three germ layers. Many times, the first step in using human embryonic stem cells for regenerative medicine is often initiated by embryoid body (EB) formation. EBs are three-dimensional multicellular aggregates that resemble early post implantation embryos that still maintain the potential to form the three germ layers. Currently, generating EBs from human embryonic stem cells (hESC) that are adapted to feeder-independent medium is difficult, much more so than feeder cultured hESC. Using a chemically defined medium would not only help the application of …

Evaluation Of Biocomposite For Implementation As Prosthetic Socket, Chelsea Long

Biological and Agricultural Engineering Undergraduate Honors Theses

According to the World Health Organization, 0.5% of the population in developing countries is in need of prostheses or orthoses. For this population, obtaining a prosthetic is made difficult due to medical and transportation costs as well as a general lack of area resources. One possible solution to these problems would be to design a prosthetic socket from an inexpensive biodegradable material that could be produced in developing countries. One such material has been developed by Ecovative Design, LLC. Ecovative’s technology grows mycelium, mushroom roots, throughout a plant fiber matrix. Ecovative products are completely biodegradable and made naturally from local …

Chitosan Reduces Water Solubility Of Phosphorus In Poultry Litter, Iain M. Bailey

Biological and Agricultural Engineering Undergraduate Honors Theses

The addition of chemical amendments to land applied poultry litter is paramount to the maintenance of acceptable phosphorus (P) and nitrogen (N) levels in stormwater runoff from pasture. Chitin is the chief component of shrimp shells, and together with its more processed form chitosan, may show promising P, N, and metal ion chelation characteristics by virtue of its chemical structure and unique charge distribution. The objective of this study was to measure the effects of aluminum sulfate (alum, Al2(SO4)3) on aqueous solubility of P and ammonia (NH3) release against those of chitin and three varieties of chitosan in poultry litter. …

Kinetics Of Xylose Oligomers Decomposition, Christopher Mcdaniel

Biological and Agricultural Engineering Undergraduate Honors Theses

Hemicellose-derived oligomers are key components in hemicellulose depolymerization into the five-carbon carbohydrate xylose, a key operation in the production of cellulosic biofuels. Unfortunately, hemicellulose oligomers do not only depolymerize directly into xylose, but also into degradation compounds that reduce the overall production of cellulosic biofuels. Because commercially available oligomers are prohibitively expensive, this study was carried out using relatively inexpensive commercial grade xylose. Understanding the degradation of xylose is important for its impact on the economic viability of the monomeric sugars-to-ethanol conversion. From experimental data and ensuing statistical analysis, initial xylose concentrations did not result in different xylose degradation rates, …

Study Of The Fundamental Chemical And Physical Interactions Between Chitosan And Hydroxyapatite, Abigail Washispack

Biological and Agricultural Engineering Undergraduate Honors Theses

Hydroxyapatite and chitosan are widely used in biomedical applications due to their biocompatibility and biodegradability. Various studies show that composites made of hydroxyapatite and chitosan exhibit desirable properties for applications in bone tissue engineering. When creating a composite it is important to understand the interfacial chemistry and physical interactions between the composite materials. An understanding of these properties gives more insight into the resulting structure of the composite on multiple levels (nano- micro- macro). This structure affects the chemical, physical, and mechanical properties of the material, thus analysis of these properties gives a better understanding of how a material will …

Extending The Hybridthread Smp Model For Distributed Memory Systems, Eugene Anthony Cartwright Iii

Graduate Theses and Dissertations

Memory Hierarchy is of growing importance in system design today. As Moore's Law allows system designers to include more processors within their designs, data locality becomes a priority. Traditional multiprocessor systems on chip (MPSoC) experience difficulty scaling as the quantity of processors increases. This challenge is common behavior of memory accesses in a shared memory environment and causes a decrease in memory bandwidth as processor numbers increase. In order to provide the necessary levels of scalability, the computer architecture community has sought to decentralize memory accesses by distributing memory throughout the system. Distributed memory offers greater bandwidth due to decoupled …

Patient And Nurse Considerations In Home Health Routing With Remote Monitoring Devices, Jessica Spicer

Graduate Theses and Dissertations

We build on the current consistent vehicle routing problem literature by formulating a novel multi- objective mathematical model of the home health scheduling and routing problem that includes the option of assigning some patient visits to remote monitoring devices, with the objectives of mini- mizing total cost, achieving nurse consistency and creating balanced nurse workloads. A heuristic solution approach that approximates the efficient frontier of this multiobjective problem is pre- sented and validated, and the results of using this methodology to solve several realistic instances are included. We also analyze the assignment of patients to devices and present some managerial …

Physiochemical And Nanomanipulation Studies Of Carbon Nanomaterials, Siva Naga Sandeep Chalamalasetty

Graduate Theses and Dissertations

Carbon nanomaterials are, without a doubt, one of man's wonder creations. Though these nanomaterials are a very recent trend, extraordinary electromechanical properties and the light weightiness of these nanomaterials attracted the attention of researchers. Although vast research has been done since the start of the US nanotechnology initiative, much effort was in the area of synthesis and characterization of the nanomaterials. However, most of the traditional macroscopic material's theories fail at the nanoscale level, and since the material properties are dependent on size and structure at nanoscale level, the behavior of the carbon nanomaterials in different environments needs attention. High …