Digital Commons Network^™

Electrokinetic Transport And Manipulation Of Particles In Curved Microchannels, Junjie Zhu

All Dissertations

The investigation of electrokinetic particle transport in confined microchannels has practical significances in a variety of applications ranging from traditional gel electrophoresis to electrokinetic microfluidics-based lab-on-a-chip devices. To date, however, studies on particle electrokinetics have been limited to primarily theoretical or numerical analyses in straight microchannels of simple geometries. Very little work has been done on electrokinetic particle motions in real microchannels which usually consist of one or multiple turns. This thesis is dedicated to the fundamental and applied studies of electrokinetic transport and manipulation of particles in various curved microchannels using a combined experimental, theoretical, and numerical method.
First, …

Cushop: A Simulated Shopping Environment Fostering Consumer-Centric Packaging Design & Testing, Charles Tonkin

All Dissertations

Consumer product packaging provides product damage protection, extends product shelf life, and communicates product usage instructions to the consumer. Its collective contribution to the waste stream is notorious, but its role in product salability is much less understood. Consumers now make the majority of product purchase decisions while present at the shelf, and since they do it very quickly (within 5-8 seconds), and do not appear to adhere to strong brand loyalty as was once more common, packaging (and more specifically, its aesthetics and contrast with its competitors) plays a dominant role in the decision-making process. It is difficult, however, …

Zeolite‐Based Algae Biofilm Rotating Photobioreactor For Algae And Biomass Production, Ashton M. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alkaline conditions induced by algae growth in wastewater stabilization ponds create deprotonated ammonium ions that result in ammonia gas (NH₃) volatilization. If algae are utilized to remediate wastewater through uptake of phosphorus, the resulting nitrogen loss will hinder this process because algae generally require a stoichiometric molar ratio of N₁₆P₁. Lower ratios of N/P due to loss of ammonia gas will limit the growth and yield of algae, and therefore will reduce phosphorus removal from the water phase into the algae phase. In order to reduce nitrogen loss through volatilization, an ammonium selective zeolite, …

Time-Dependent Crack Growth Behavior Of Alloy 617 And Alloy 230 At Elevated Temperatures, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two Ni-base solid-solution-strengthened superalloys: INCONEL 617 and HAYNES 230 were studied to check sustained loading crack growth (SLCG) behavior at elevated temperatures appropriate for Next Generation Nuclear Plant (NGNP) applictaions with constant stress intensity factor (K _max = 27.75 MPa[checkmark]m) in air. The results indicate a time-dependent rate controlling process which can be characterized by a linear elastic fracture mechanics (LEFM) parameter - stress intensity factor (K). At elevated temperatures, the crack growth mechanism was best described using a damage zone concept. Based on results and study, SAGBOE (stress accelerated grain boundary oxidation embrittlement) is considered the primary reason for …

Expression And Characterization Of Protein Chimera With Embedded Activated Protein C Generation, Minjeong Schneider

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Increasing demand of medical implants has lead researchers to develop biomaterial surfaces that offer improved performance and lower thrombogenecity. There have been attempts to model biomaterial surfaces after the native endothelium as it represents an optimal non-thrombotic surface. Typically, when biomaterials are contacted with blood, they often invoke the activation of clotting cascades. Thus, to overcome surface mediated thrombotic events, proteins and molecules with anticoagulant attributes of the endothelium have been immobilized onto biomaterial surfaces. Protein C (PC) plays a main role in blood coagulation and acts as an anticoagulant when it is converted into activated protein C (APC). Activation …

Application Of Shredded-Tire Biofilter And Membrane Bioreactor For Greywater Reclamation, Meng Hu

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Water scarcity is a pressing global issue. Greywater (GW) reclamation is a viable option to reduce freshwater demand. The objectives of this work were to: a) evaluate the feasibility of the combination of shredded tire biofilter (STB) technology and membrane bioreactor (MBR) technology in GW reclamation; b) study the effects of various parameters on STB performance; and c) understand the fouling mechanisms to lower the energy consumption in MBRs. Bench-scale STBs and MBRs (flat-sheet membranes) were constructed to address the first two objectives, while an independent membrane (hollow-fiber membranes) fouling experiment was designed for the third objective.

It was found …

Low-Resolution Vision For Autonomous Mobile Robots, Vidya Nariyambut Murali

All Dissertations

The goal of this research is to develop algorithms using low-resolution images to perceive and understand a typical indoor environment and thereby enable a mobile robot to autonomously navigate such an environment. We present techniques for three problems: autonomous exploration, corridor classification, and minimalistic geometric representation of an indoor environment for navigation.
First, we present a technique for mobile robot exploration in unknown indoor environments using only a single forward-facing camera. Rather than processing all the data, the method intermittently examines only small 32X24 downsampled grayscale images. We show that for the task of indoor exploration the visual information is …

Using Discrete Event Computer Simulation To Analyze The Effects Of Proposed Changes To Personnel In A Hospital Medical Laboratory, Gerardo Morales

Theses and Dissertations - UTB/UTPA

A discrete event computer simulation is used to model a portion of the medical laboratory at Doctors Hospital at Renaissance in order to assess the current situation as well as to review the planed personnel changes. The area under observation is the section in which the processor(s) receive, label and distribute the patient samples. There are four cases modeled in the simulation: The main focus is to determine if one or two processors are needed per shift and if the high level of phone calls poses a significant delay to the processors’ workflow. The simulation results indicate that having two …

Dynamic, Stochastic, Computational, And Scalable Technologies For Smart Grids, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

The smart electric power grid will evolve into a very complex adaptive system under semi-autonomous distributed control. its spatial and temporal complexity, non-convexity, non-linearity, non-stationarity, variability and uncertainties exceed the characteristics found in today's traditional power system. the distributed integration of intermittent sources of energy and plug-in electric vehicles to a smart grid further adds complexity and challenges to its modeling, control and optimization. Innovative technologies are needed to handle the growing complexity of the smart grid and stochastic bidirectional optimal power flows, to maximize the penetration of renewable energy, and to provide maximum utilization of available energy storage, especially …

Quantitative Analysis Of The Reaction Between Gliadin And Citric Acid Under Weak Acidic And Weak Alkaline Conditions, Wei Li

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Gliadin was reacted with citric acid under weak acidic and weak alkaline conditions in both wet and dry states and the reaction mechanism was studied. The low morphological stability in an aqueous environment and inferior mechanical properties have restricted the applications of plant proteins, although these materials possess a unique structure, biocompatibility and biodegradability. Carboxylic acids such as citric acid are inexpensive and nontoxic chemicals and are preferred for crosslinking proteins and cellulose to improve the desired properties of the materials.

In this study, gliadin was chosen as a model of plant proteins to react with citric acid. However, previous …

Silk Fibroin-Based Scaffolds For Tissue Engineering Applications, Jennifer Mccool

Theses and Dissertations

This study focused on the comparison of the electrospun silk scaffolds to the electrospun silk fibroin gel scaffolds. Moreover, this study examined the differences in cross-linking effects of genipin and methanol as well as solvents on the mechanical properties and cell compatibility of the scaffolds. Silk scaffolds were electrospun from an aqueous solution or 1,1,1,3,3-hexafluoro-2-propanol (HFIP) without genipin, immediately after 8 % (wt) genipin was added to the solution, and 18 hours after genipin blended with the solution. Uniaxial tensile testing determined that the silk scaffolds electrospun from water exhibit a higher modulus and peak stress than that of the …

Miniature Mass Spectrometry: Rf Amplitude Control System Design, Matthew Allen Kirleis

Purdue Polytechnic Masters Theses

This thesis covers the methods used to construct and characterize a custom digital RF amplitude control system. Many types of mass spectrometers exist, but few have been miniaturized as much as the Mini instruments developed at Purdue University. The goal of this research was to improve upon an earlier amplitude control system consisting of analog circuits first implemented in the Mini 11.5 mass spectrometer developed at Purdue University.

A custom set of control and data acquisition electronics were developed for testing the digital and analog control systems in a Mini 11.5 mass spectrometer chassis. A MATLAB Simulink simulation was done …

Applied And Mechanistic Studies Of Microbial 17beta-Estradiol Degradation, Zhongtian Li

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The presence of natural estrogens, a class of endocrine disrupting compounds, in water has caused increasing concerns over their adverse impacts on the health of aquatic eco-systems and human beings. In this study, adsorption characteristics of two natural estrogens, 17β-estradiol (E2) and estrone (E1), on granular activated carbon (GAC) were investigated in isotherm tests and in a GAC column. The GAC column was then converted to a biologically active carbon (BAC) column and the removal efficiency of E2 and its primary biodegradation intermediate E1 were monitored. During BAC operation, the impacts of various reactor operation parameters, such as the carbon …

53rd Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 53rd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Snowmass, Colorado, July 24-28, 2011.

Enhanced Degradation Of Fats, Oils And Greases In Domestic Wastewater Sewer Networks And Grease Interception Systems Using Peat Humic Substances, Matthew Hunnemeder

Theses and Dissertations

The efficacy of peat humic substances in enhancing the degradation of fats, oils and greases (FOG) was investigated under controlled laboratory conditions using bench scale well-mixed bioreactors. An experimental design was used to evaluate the effects of temperature and peat humic substance (PHS) concentration on FOG degradation in domestic wastewater for a temperature range from 10 deg.C to 30 deg.C and a PHS concentration range from 0 to 20 ppm(v). Factors and interactions significantly affecting the rate of FOG degradation were identified, and models to predict FOG degradation rates as a function of PHS concentration and temperature were developed. The …

Mobilization Of Endocrine‐Disrupting Chemicals And Estrogenic Activity In Simulated Rainfall Runoff From Land‐Applied Biosolids, Ben D. Giudice, Thomas M. Young

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Municipal biosolids are commonly applied to land as soil amendment or fertilizer as a form of beneficial reuse of what could otherwise be viewed as waste. Balanced against this benefit are potential risks to groundwater and surface water quality from constituents that may be mobilized during storm events. The objective of the present study was to characterize the mobilization of selected endocrinedisrupting compounds, heavy metals, and total estrogenic activity in rainfall runoff from land-applied biosolids. Rainfall simulations were conducted on soil plots amended with biosolids. Surface runoff and leachate was collected and analyzed for the endocrinedisrupting compounds bisphenol A, 17a-ethynylestradiol, …

Modeling Particle Filtration And Caking In Fibrous Filter Media, Seyed Alireza Hosseini

Theses and Dissertations

This study is aimed at developing modeling methodologies for simulating the flow of air and aerosol particles through fibrous filter media made up of micro- or nano-fibers. The study also deals with modeling particle deposition (due to Brownian diffusion, interception, and inertial impaction) and particle cake formation, on or inside fibrous filters. By computing the air flow field and the trajectory of airborne particles in 3-D virtual geometries that resemble the internal microstructure of fibrous filter media, pressure drop and collection efficiency of micro- or nano-fiber filters are simulated and compared with the available experimental studies. It was demonstrated that …

Zein Nanospheres For Gene Delivery, Mary C. Regier

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Particulates incorporating DNA provide for protection and sustained release of DNA, and thus are promising candidates for DNA delivery systems. Among the routes of administration for gene delivery, the oral route is perhaps the most appealing as it is associated with patient comfort and compliance and allows for targeting to intestinal targets for therapeutic and vaccination applications. With the goal of realizing the potential of an oral DNA delivery system, zein, a hydrophobic protein from corn that is biocompatible and degraded enzymatically, was investigated. This thesis describes the formulation of zein nanospheres encapsulating DNA by a coacervation technique and their …

Developing A Hybrid Model To Predict Student First Year Retention And Academic Success In Stem Disciplines Using Neural Networks, Ruba Alkhasawneh

Theses and Dissertations

Understanding the reasoning behind the low enrollment and retention rates of Underrepresented Minority (URM) students (African Americans, Hispanic Americans, and Native Americans) in the disciplines of science, technology, engineering, and mathematics (STEM) has concerned many researchers for decades. Numerous studies have used traditional statistical methods to identify factors that affect and predict student retention. Recently, researchers have relied on using data mining techniques for modeling student retention in higher education [1]. This research has used neural networks for performance modeling in order to obtain an adequate understanding of factors related to first year academic success and retention of URM at …

Relating Climatic Attributes And Water Resources Allocation: A Study Using Surface Water Supply And Soil Moisture Indices In The Snake River Basin, Idaho, David J. Hoekema, Venkataramana Sridhar

Civil Engineering Faculty Publications and Presentations

Climate change forced by anthropogenic activities has been ongoing since at least the beginning of the industrial revolution. Part of the recent warming in the western United States has been attributed to anthropogenic climate change. This research seeks to answer the basic question of how declining streamflow, increasing temperatures, and fluctuation in precipitation have impacted water resource allocation in the Snake River Plain over the past 35 years (1971-2005). Understanding how changes in climatic attributes have historically impacted water allocation should help water managers better understand how projected climate change may influence allocation. Annual and monthly diversion trends from 62 …

Design And Analysis Of A Flapping Wing Mechanism For Optimization, Ryan Brandon George

Theses and Dissertations

Furthering our understanding of the physics of flapping flight has the potential to benefit the field of micro air vehicles. Advancements in micro air vehicles can benefit applications such as surveillance, reconnaissance, and search and rescue. In this research, flapping kinematics of a ladybug was explored using a direct linear transformation. A flapping mechanism design is presented that was capable of executing ladybug or other species-specific kinematics. The mechanism was based on a differential gear design, had two wings, and could flap in harsh environments. This mechanism served as a test bed for force analysis and optimization studies. The first …

Artificial Lateral Line Canal For Hydrodynamic Detection, Yingchen Yang, Adrian Klein, Horst Bleckmann

Mechanical Engineering Faculty Publications

Fish use their lateral line system to detect minute water motions. The lateral line consists of superficial neuromasts and canal neuromasts. The response properties of canal neuromasts differ from those of superficial ones. Here, we report the design, fabrication, and characterization of an artificial lateral line canal system. The characterization was done under various fluid conditions, including dipolar excitation and turbulent flow. The experimental results with dipole excitation match well with a mathematical model. Canal sensors also demonstrate significantly better noise immunity compared with superficial ones. Canal-type artificial lateral lines may become important for underwater flow sensing.

Artificial Lateral Line Canal For Hydrodynamic Detection, Yingchen Yang, Adrian Klein, Horst Bleckmann, Chang Liu

Mechanical Engineering Faculty Publications

Fish use their lateral line system to detect minute water motions. The lateral line consists of superficial neuromasts and canal neuromasts. The response properties of canal neuromasts differ from those of superficial ones. Here, we report the design, fabrication, and characterization of an artificial lateral line canal system. The characterization was done under various fluid conditions, including dipolar excitation and turbulent flow. The experimental results with dipole excitation match well with a mathematical model. Canal sensors also demonstrate significantly better noise immunity compared with superficial ones. Canal-type artificial lateral lines may become important for underwater flow sensing.

Mapping And Modeling Chlorophyll-A Concentrations In Utah Lake Using Landsat 7 Etm+ Imagery, Victor Nii Afum Narteh

Theses and Dissertations

This study shows the results of testing previous research that used remote sensing techniques to determine chlorophyll-a concentrations in turbid surface waters, and developing similar methods and models for Utah Lake using Landsat 7 ETM+ satellite imagery and field measured concentrations of chlorophyll-a. The data for the study included images acquired on June 22 and July 8, 2009. The field data included ground measurements taken on June 22 and July 6, 2009 from seven water quality sampling locations. The 48 hour time difference between the Landsat image acquisition (July 8) and the field measurement (July 6), and the small sample …

Effects Of Β-Cyclodextrin As A Capping Agent On The Antibacterial Properties Of Agnps, Swarna Jaiswal, Brendan Duffy, Patrick Mchale

Conference Papers

No abstract provided.

Spinal Implant With Customized And Non-Linear Stiffness, Eric Ray Dodgen

Theses and Dissertations

There is a need for spinal implants that have nonlinear stiffness to provide stabilization if the spine loses stiffness through injury, degeneration, or surgery. There is also a need for spinal implants to be customizable for individual needs, and to be small enough to be unobtrusive once implanted. Past and ongoing work that defines the effects of degeneration on the torque rotation curve of a functional spinal unit (FSU) were used to produce a spinal implant which could meet these requirements. This thesis proposes contact-aided inserts to be used with the FlexSuRe™ spinal implant to create a nonlinear stiffness. Moreover, …

Eddy Impaction As An Ash Deposition Mechanism: A Theoretical And Experimental Investigation, Minmin Li

Theses and Dissertations

The eddy impaction ash deposition model derived and validated in this document predicts eddy impaction rates as a function of turbulence intensity, boundary layer thickness, and gas velocity. The experimental apparatus introduces small particles (200 nm, 25 µm, and 500 µm diameter) into a gas stream flowing through a horizontal pipe (Re 2,300-8,000). The particles deposit on the pipe wall and the total mass of impacted particles provides a measure of collection efficiency. Experimental results indicate deposition velocity increases with Reynolds number, consistent with eddy impaction theory and based on increased turbulent energy. Eddy impaction also increases with particle size …

Mechanical Characterization Of The Interspinous Ligament Using Anisotropic Small Punch Testing, Rachel Jane Bradshaw

Theses and Dissertations

Objective: The objective of this work was to characterize the nonlinear anisotropic material constitutive response of the interspinous ligament (ISL).

Methods: Cadaveric test samples of the interspinous ligament were tested using the anisotropic small punch test. The measured force-displacement response served as experimental input into a system identification optimization routine to determine the constitutive material parameters that replicated the measured material response.

Results: The constitutive behavior of the ISL is notably different from that reported for knee, shoulder, and hip ligaments. Specifically, the high collagen fiber content and unique collagen architecture provided a stiffer material response. The results from the …

Characterization Of The Mechanical Response Of The Lumbar Spine, Shannon Alisa Zirbel

Theses and Dissertations

The primary objective of this research is to associate lumbar segmental mechanical response with intervertebral disc degeneration under physiologic testing conditions. Because no mathematical model exists for lumbar spine segmental rotations, a portion of this thesis evaluates potential methods for curve fitting the torque-rotation curves. The Dual Inflection Point (DIP) Boltzmann equation was developed during the course of this research and is presented here as a method for fitting spinal motion data wherein a physical meaning can be assigned to each of the model coefficients. This model can tell us more about the effects of degeneration, testing conditions, and other …

Selective Epitaxial Growth Techniques To Integrate High-Quality Germanium On Silicon, Darin Leonhardt

Chemical and Biological Engineering ETDs

High-quality Ge-on-Si heterostructures have been actively pursued for many advanced applications, including near-infrared photodetectors, high-mobility field effect transistors, and virtual substrates for integrating III-V multijunction solar cells. However, growing epitaxial Ge on Si poses many engineering challenges, ranging from lattice mismatch, to thermal expansion coefficient mismatch, to non-planar morphological evolution. The lattice mismatch between Ge and Si often leads to a high density of threading dislocations. These dislocations, if not reduced, propagate through the subsequently grown GaAs layer, deteriorating its quality. To overcome these engineering challenges, we have developed three different approaches based on molecular beam epitaxy to significantly reduce, …