Engineering Commons^™

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Graduate Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied …

Development Of A One Pass Microwave Heating Technology For Rice Drying And Decontamination, Deandrae Lynette Smith

Graduate Theses and Dissertations

An industrial microwave (MW) system operating at 915 MHz frequency was used to dry high moisture content (MC) (23% to 24% wet basis) medium-grain rough rice samples (cv. Jupiter). The rice beds were contained in a modified tray that accommodated up to 9 kg of rice separated by thin fiberglass mesh in 3 kg increments. Each layer of rice was fitted with fiber optic sensors connected to a real time data logger during MW treatments. It was determined that drying rice to a MC of 14% to 16% was feasible with the application of MW specific energy at 600 kJ/kg-grain …

Membrane Chromatography For Bioseparations: Ligand Design And Optimization, Zizhao Liu

Graduate Theses and Dissertations

Membrane chromatography, or membrane adsorber, represents an attractive alternative to conventional packed bed chromatography used in downstream processing. Membrane chromatography has many advantages, including high productivity, low buffer consumption and ease to scale up. This doctoral dissertation focuses on developing novel polymeric ligands for protein separations using membrane chromatography. Atom transfer radical polymerization (ATRP), known as a controlled radical polymerization technique, has been used to control the architecture of grafted polymeric ligands. The center theme of this dissertation is to develop new polymeric ligands and investigate how the polymer’s property (e.g. flexibility, hydrophobicity) and architecture (e.g. chain density, chain length) …

Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker

Graduate Theses and Dissertations

Following injury to the central nervous system, extracellular modulations are apparent at

the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of …

Coarse-Grained Simulations Of The Self-Assembly Of Dna-Linked Gold Nanoparticle Building Blocks, Charles Wrightsman Armistead

Graduate Theses and Dissertations

The self-assembly of nanoparticles (NPs) of varying shape, size, and composition for the purpose of constructing useful nanoassemblies with tailored properties remains challenging. Although progress has been made to design anisotropic building blocks that exhibit the required control for the precise placement of various NPs within a defined arrangement, there still exists obstacles in the technology to maximize the programmability in the self-assembly of NP building blocks. Currently, the self-assembly of nanostructures involves much experimental trial and error. Computational modeling is a possible approach that could be utilized to facilitate the purposeful design of the self-assembly of NP building blocks …

Examination Of Pseudomonas Fluorescence As A Recombinant Expression Host: Cloning, Expression, And Chromatography, Ahmed K.Ali Elmasheiti

Graduate Theses and Dissertations

In an effort to expand the pool of bacterium useful for biotechnology applications, Pseudomonas fluorescens, a common gram negative microbe, was examined for its ability to function in a recombinant setting. P. fluorescens is ubiquitous in nature and was initially identified as a soil bacterium found in dirt and is typically associated with plant material. Past literature indicates that it shared characteristics common to Escherichia coli and Bacillus subtilis, including simple growth conditions and potential cloning vectors, providing motivation to look into both the upstream and downstream characteristics of this bacterium. First, it was demonstrated that P. fluorescens could be …

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao

Graduate Theses and Dissertations

Foodborne diseases are a growing public health problem. In recent years, many rapid detection methods have been reported, but most of them are still in lab research and not practical for use in the field. In this study, a portable and automatic biosensing instrument was designed and constructed for separation and detection of target pathogens in food samples using nanobead-based magnetic separation and quantum dots (QDs)-labeled fluorescence measurement. The instrument consisted of a laptop with LabVIEW software, a data acquisition card (DAQ), a fluorescent detector, micro-pumps, stepper motors, and 3D printed tube holders. First, a sample in a syringe was …

A Bifunctional Nanocomposites Based Electrochemical Biosensor For In-Field Detection Of Pathogenic Bacteria In Food, Meng Xu

Graduate Theses and Dissertations

This research focused on the application of electrochemical biosensors for the rapid detection of pathogenic bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium, in foods. The possible presence of pathogenic bacteria in foods has always been a great threat to the wellbeing of people and the revenue of food companies. Therefore, the demand for rapid and sensitive methods to detect foodborne pathogens is growing. In this research, an impedimetric immunosensor was first developed for the rapid detection of E. coli O157:H7 and S. Typhimurium in foods. It was based on the techniques of immunomagnetic separation, enzyme labelling, and electrochemical impedance spectroscopy …

Experimental And Computational Studies Of Cortical Neural Network Properties Through Signal Processing, Wesley Patrick Clawson

Graduate Theses and Dissertations

Previous studies, both theoretical and experimental, of network level dynamics in the cerebral cortex show evidence for a statistical phenomenon called criticality; a phenomenon originally studied in the context of phase transitions in physical systems and that is associated with favorable information processing in the context of the brain. The focus of this thesis is to expand upon past results with new experimentation and modeling to show a relationship between criticality and the ability to detect and discriminate sensory input. A line of theoretical work predicts maximal sensory discrimination as a functional benefit of criticality, which can then be characterized …

Genotoxicity Of Graphene In Escherichia Coli, Ananya Sharma

Graduate Theses and Dissertations

Rapid advances in nanotechnology necessitate assessment of the safety of nanomaterials in the resulting products and applications. One key nanomaterial attracting much interest in many areas of science and technology is graphene. Graphene is a one atom thick carbon allotrope arranged in a two-dimensional honeycomb lattice. In addition to being extremely thin, graphene has several extraordinary physical properties such as its exceptional mechanical strength, thermal stability, and high electrical conductivity. Graphene itself is relatively chemically inert and therefore pristine graphene must undergo a process called functionalization, which is combination of chemical and physical treatments that change the properties of graphene, …

Assessment Of An Industrial Type Radiant Heating System For Drying Rough Rice, Anne Adhiambo Okeyo

Graduate Theses and Dissertations

Rough rice is normally harvested at moisture contents (MCs) higher than that for safe storage. The objective for this study was to investigate the effectiveness of scaled-up infrared (IR) heating followed by tempering steps to dry freshly-harvested rough rice. An industrial type, pilot scale, IR drying equipment, designed to convey rough rice on a vibrating conveyor belt was used in this study. The heating zone of the equipment had catalytic IR emitters powered by natural gas. Freshly-harvested rough rice of long-grain pureline (cv. Cheniere), long-grain hybrid (cv. 6XP 756) and medium-grain (cv. CL 271) cultivars at initial moisture contents (IMCs) …

Investigation Of The Inherent Chemical, Structural, And Mechanical Attributes Of Bio-Engineered Composites Found In Nature: Alligator Gar’S Exoskeleton Fish Scales, Wayne Derald Hodo

Graduate Theses and Dissertations

The U.S. Army has determined a huge cost savings of up to 51% can be accomplished by reducing the gross vehicle weight, for their personnel carrier, by 33%. To cut cost, composite materials are needed. Man-made composites can have superior material properties (high-strength, high-fracture toughness, and lightweight), but they are prone to delamination at the glued-layered interface. In contrast, fish scale is a natural composite that has the same material properties and, additionally, tend not to delaminate.

The focus of this study was to learn how nature integrates hard and soft materials at each length scale to form a layered …

Storage Of Round And Square Switchgrass Bales: Effect Of Storage Time And Fungal Inoculation On Saccharification Efficiency, Noaa Frederick

Graduate Theses and Dissertations

To produce fermentable sugars from lignocellulosic biomass feedstock, severe pretreatment conditions are needed (either high acid concentration, temperature, or retention times). High severities can produce toxic byproducts which inhibit enzymatic hydrolysis or fermentation. In order to reduce pretreatment severities (and thus increase enzyme and fermentation efficiency), the white-rot fungus Pleurotus ostreastus was seeded into square and round bales of Kanlow switchgrass (Panicum virgastum L.) and left in the field over a period of 9 month. The laccase producing fungus is believed to selectively degrade lignin, a common plant structural polymer, which can function as an enzymatic inhibitor. Samples were taken …

Eicosapentaenoic Acid (Epa) From Porphyridium Cruentum: Increasing Growth And Productivity Of The Microalgae For Pharmaceutical Products, Maryam Asgharpour

Graduate Theses and Dissertations

One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate …

Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu

Graduate Theses and Dissertations

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in …

Using Peptoids To Build Robust, Efficient Microarray Systems, Dhaval Sunil Shah

Graduate Theses and Dissertations

Recent studies have shown microarrays to be indispensable for various biological applications, allowing for high-throughput processing and screening of biological samples such as RNA, DNA, proteins and peptides using a small sample volume (< 1 µL). Peptoids (poly-N-substituted glycine oligomers) can be used as a substitute for antibodies as capture molecules, as well as coatings for slides in antibody microarrays. The ease of synthesis of peptoids, high customizability with desired bioactivity, and speed of synthesis allows us to build a diagnostic system with a large dynamic range that can detect biomolecules from a minimal sample size. In this study, peptoid-based antibody mimics are designed to have both structural and functional features similar to those of antibodies, including a stable constant region (scaffolding) and a variable region for protein recognition. Peptoids previously screened via combinatorial library synthesis to be specific to bind Mdm-2 (mouse double minute 2 homolog) and GST (gluthathione S-transferase), have been synthesized. The protein recognition peptoids have been conjugated to PEG (polyethylene glycol) molecules with modified end groups; an amine group on one end that allows for immobilization and orientation on the slide, and an azide group on the other end that will allow for attachment to the peptoid through “click chemistry”. The number of capture molecules printed on the slides can be increased by making the available surface area of the slide larger via coating with microspheres. We have determined that partially water soluble peptoids that are also helical, can self-assemble into microspheres. Sequences have been developed that can consistently produce uniform microsphere coatings on slides that increase the overall surface area. A high surface area corresponds to a higher number of binding sites, and therefore a more sensitive system. The work done has shown that slides may be successfully coated in order to potentially improve the detection system.

Numerical Simulation Of Terahertz Wave Interaction With Breast Cancer Tumor Tissue Sections, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

This thesis presents numerical simulation of terahertz (THz) wave interaction with breast cancer tumor tissue sections. The obtained results are expressed in THz images of heterogeneous material that mimics the excised breast cancer tissue sections. The finite-element software package ANSYS High Frequency Structural Simulator (HFSS) was used in this work. HFSS is a full wave frequency domain three-dimensional (3D) electromagnetic simulation package. In this work, four breast cancer tissue models based on pathology images were simulated and images of the models were obtained at 1 THz. An incident Gaussian beam was raster scanned over tissue model configurations and the reflected …

A Cradle To Farm Gate Life Cycle Analysis Of Land Use In U.S. Pork Production, William Benjamin Putman

Graduate Theses and Dissertations

The goal of this study was to conduct a detailed Life Cycle Assessment (LCA) of the U.S. live swine production supply chain to quantify land use requirements and to assess the impact associated with various ration compositions. The functional unit was defined as one kilogram (2.2 pounds) of live swine at the farm gate, ready for transport to the abattoir. This assessment focused on the three highest producing USDA regions, which encompassed the Midwest (Regions 5 and 7) and the Southeast (Region 4), representing 86% of U.S. market hog production.

First, a literature review was conducted to summarize the most …

Identifying, Monitoring, Quantifying And Converting Algae To Bio-Fuels In Bio-Reactors, Alice C. Jernigan

Graduate Theses and Dissertations

Growing algae as a source for bio-fuels has become an area of interest due to concerns about global warming and the reliability and ecology of the production of fossil fuels. Dried algae harvested from a pilot water quality improvement technology at the Rockaway Wastewater Treatment Facility in New York were examined as a source of carbohydrates and lipids for the production of bio-fuels in bio-reactors. The length of storage time, storage conditions, sugar and lipid extraction processes, and fuel production were studied. The results show that if the algae is stored dry (0.015 g/g algae even after a year in …

Monodentate, Bidentate And Photocrosslinkable Thiol Ligands For Improving Aqueous Biocompatible Quantum Dots, Hiroko Takeuchi

Graduate Theses and Dissertations

Water-soluble Quantum Dots (QDs) are highly sensitive fluorescent probes that are often used to study biological species. One of the most common ways to render QDs water-soluble for such applications is to apply hydrophilic thiolated ligands to the QD surface. However, these ligands are labile and can be easily exchanged on the QD surface, which can severely limit their application. As one way to overcome this limitation while maintaining a small colloidal size of QDs, we developed a method to stabilize hydrophilic thiolated ligands on the surface of QDs through the formation of a crosslinked shell using a photocrosslinking approach. …

The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller

Graduate Theses and Dissertations

Approximately 1.7 million Americans experience a traumatic brain injury (TBI) each year. Concussive injuries are a subset of TBI in which blows to the head cause the brain to collide against the interior of the skull. Damage to the neurons, supporting cells, and surrounding extra cellular matrix resulting from these collisions can lead to permanent physical, cognitive, and psychological impairment. We believe the prevalence and clinical significance of concussive injures warrants research investment. To study brain injury following TBI, in vivo models have been the gold standard for TBI experiments. Although a valuable research alternative, animals are expensive, raise ethical …

Algae To Propellants: Biosynthesis Of 1,2-Propanediol From Algal Derived Sugars, Lauren Rachelle Merriman

Graduate Theses and Dissertations

Propylene glycol dinitrate (PGDN) is an important component used in the formulation of energetic materials. A renewable, environmentally-friendly and effective production technique for the production of 1,2-propanediol, an important precursor to PGDN, is desired. While fermentation of 1,2-propanediol has been achieved, it suffers from major limitations such as expensive feed sugars and relatively low yields. It is hypothesized that algae sugars could serve as a feedstock for the microbial synthesis of 1,2-propanediol, thereby reducing production costs and enhancing sustainability.

Algal biomass produced from an Algal Turf Scrubber® has proven to have significant potential as a source of fermentable materials. However, …

Expression, Production, And Purification Of Novel Therapeutic Proteins, Mckinzie Shea Fruchtl

Graduate Theses and Dissertations

Interest in the production of recombinant proteins consisting of collagen binding domain (CBD) fused to a bioactive material has increased due to the targeting/attachment capabilities of CBD. For example, CBD fusions can be applied to the reversing of bone density loss and the repair of the eardrum, specifically, by choosing an appropriate fusion partner (parathyroid hormone or epidermal growth factor). The production of CBD fusions was examined using batch and fed-batch culturing of Escherichia coli to express the fusion proteins, and affinity chromatography to isolate the final product.

Different medium formulations, feeding strategies, and induction methods were tested in order …

The Geometry And Sensitivity Of Ion-Beam Sculpted Nanopores For Single Molecule Dna Analysis, Ryan Connor Rollings

Graduate Theses and Dissertations

In this dissertation, the relationship between the geometry of ion-beam sculpted solid-state nanopores and their ability to analyze single DNA molecules using resistive pulse sensing is investigated. To accomplish this, the three dimensional shape of the nanopore is determined using energy filtered and tomographic transmission electron microscopy. It is shown that this information enables the prediction of the ionic current passing through a voltage biased nanopore and improves the prediction of the magnitude of current drop signals when the nanopore interacts with single DNA molecules. The dimensional stability of nanopores in solution is monitored using this information and is improved …

Capillary And Microchip Electrophoresis For The Monitoring Of Disease Causing Amyloid Proteins, Elizabeth Nancy Pryor

Graduate Theses and Dissertations

The detection of oligomers and aggregates formed by two amyloid proteins, insulin and amyloid-beta (AB), is of particular importance due to the role which these species play in Diabetes and Alzheimer's disease, respectively. However, existing techniques are limited in the ability to detect insulin and AB; oligomers due to the fact that these early aggregates are transient, present at low concentrations, and difficult to isolate. Improvements must be made to existing techniques or alternative techniques must be explored in order to identify and quantify the size of these oligomeric and aggregate species without disrupting their structure.

Capillary and microchip electrophoresis …

Peptoid Based Slide Coatings For Disease Detection Via Elisa Microarray Analysis, Melissa Lea Hebert

Graduate Theses and Dissertations

Poly-N-substituted glycines (peptoids) are a very versatile family of synthetic molecules that can be customized for any number of applications. In this study, we chose to use peptoids as a foundation for sandwich ELISA microarray analysis with a long term goal of creating an early detection device for complex diseases such as cancer. The peptoids were designed to self-assemble into microspheres to be used in coatings on the surface of the microarray substrates to increase the surface area available for antibody attachment. This increased antibody density would lead to an increase in the microarray analysis sensitivity and dynamic range. Studies …

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 …

Proteome Based Development Of Novel Affinity Tail For Immobilized Metal Affinity Chromatography And Hydrophobic Interaction Chromatography, Neha Tiwari

Graduate Theses and Dissertations

At industrial scale, reducing the step in purification and recovery is desired; this not only decreases the cost but also increases the yield. Hydrophobic Interaction Chromatography (HIC) and Immobilized Metal Affinity Chromatography (IMAC) both are not harsh on biological structure or activity of proteins; also both the techniques are economical and therefore a suitable choice at industrial level. This dissertation comprises of three parts. Purpose for the Part I was to identify and characterize Escherichia coli proteins which display affinity towards both IMAC and Hydrophobic Interaction Chromatography (HIC). Co (II) IMAC was chosen as the primary capture step, followed by …

Improvements On Just-About-Right (Jar) Scales As Product Optimization Tools Using Kano Modeling Concepts, Bangde Li

Graduate Theses and Dissertations

Attribute Kano characteristics are useful in product design to prioritize development efforts. However, attribute Kano characteristics have not been discussed and applied to product optimization when using Just-About-Right (JAR) scales. Product optimizations without identifying attributes Kano characteristics can be misleading. The two objectives in this research were: 1. Determine attribute Kano categories using a modified classic Kano classification methodology. 2. Propose a method to measure attribute performance and identify attribute Kano characteristics to direct product optimization. Two methodologies of attribute Kano classification were investigated. In experiment one, a modified classic Kano methodology was employed to determine attribute Kano categories through …