Digital Commons Network^™

Evolutionary Optimization Algorithms For Nonlinear Systems, Ashish Raj

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the real world, we encounter a number of problems which require iterative methods rather than heuristic approaches to solve them. Not every problem can be solved with a definitive method. Optimization algorithms come to the aid of such instances. These algorithms carry out multiple iterations or generations to try to achieve the lowest value of a cost function. The demand for fast and robust stochastic algorithms to cater to the optimization needs is very high. The faster the convergence to a low value of the cost function, the better the algorithm is. This is attained in greedy criterion approaches, …

Applications Of Bayesian Statistics In Fluvial Bed Load Transport, Mark L. Schmelter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The science of fluvial sediment transport studies the processes involved in the movement of river sediments. It is commonly understood that when rivers flood they have a great capacity to move sand, gravel, and even larger cobbles and boulders. This process is not only limited to the big floods that usually attract so much attention, but also the more common river flows play a very important role in forming a river. As engineers and scientists, we like to be able to develop equations and relationships that describe some natural phenomenon—in this case, fluvial sediment transport. While we are able to …

Design Of An Experimental Approach To Study The Growth Of Biofilm On Polymethylmethacrylate, Eireen S. Escalona

Biomedical Engineering

Biofilms are present in virtually every solid-liquid contact surface and are partially responsible for some diseases and water cleaning. They are a community of a variety of organisms that live symbiotically and are bound together by extracellular polymeric substances, or EPS. Biofilms go through five stages of development. These include initial and irreversible attachments, maturations I and II, and dispersion. In the dental world, biofilms are often associated with mouth infections including dental caries, gingivitis and periodontitis. Elderly denture wearers are susceptible to the pathogen-causing bacteria associated with these diseases, particularly those who have Alzheimer's disease or other forms of …

Robust Parameter Design In Complex Engineering Systems:, Gregory Boylan

All Dissertations

Many industrial firms seek the systematic reduction of variability as a primary means for reducing production cost and material waste without sacrificing product quality or process efficiency. Despite notable advancements in quality-based estimation and optimization approaches aimed at achieving this goal, various gaps remain between current methodologies and observed in modern industrial environments. In many cases, models rely on assumptions that either limit their usefulness or diminish the reliability of the estimated results. This includes instances where models are generalized to a specific set of assumed process conditions, which constrains their applicability against a wider array of industrial problems. However, …

Engineering A Biomimetic Structure For Human Long Bone Regeneration, Eleni Katsanevakis

All Dissertations

Bone tissue serves many functions, including structural support, protection of internal organs, and mineral and growth factor storage, to name a few. Moreover, human bone exhibits excellent mechanical properties, demonstrating superb compressive strength as well as significant elasticity, due to its collagen content. However, defects still occur at a relatively high rate in this tissue. Critical sized defects in bone are defined as defects that cannot form a union and heal on their own. These types of defects occur often, and typically require surgical intervention. The current gold standard treatment for critical sized defects in bone is the use of …

Adaptive Model Based Combustion Phasing Control For Multi Fuel Spark Ignition Engines, Baitao Xiao

All Dissertations

This research describes a physics-based control-oriented feed-forward model, combined with cylinder pressure feedback, to regulate combustion phasing in a spark-ignition engine operating on an unknown mix of fuels. This research may help enable internal combustion engines that are capable of on-the-fly adaptation to a wide range of fuels. These engines could; (1) facilitate a reduction in bio-fuel processing, (2) encourage locally-appropriate bio-fuels to reduce transportation, (3) allow new fuel formulations to enter the market with minimal infrastructure, and (4) enable engine adaptation to pump-to-pump fuel variations. These outcomes will help make bio-fuels cost-competitive with other transportation fuels, lessen dependence on …

Optimization Of Polyhydroxybutyrate Production In Recombinant Escherichia Coli Through Metabolic Modeling And Simulation, Yoshitaro Heshiki

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The objective of this study is to optimize the growth media and genes to maximize PHB production computer simulations, and to evaluate the simulation results through experiments. In order to achieve this objective, the metabolism of E. coli that produces PHB was modeled using the existing E. coli genome-scale metabolic networks. To identify the best additional nutrient for PHB production, carbon sources, minerals, amiano acids, nitrogen sources, and sulfur sources were examined by production potential analysis. Strain design was conducted to find the unwanted reactions to overexpress PHB synthesis pathway.

Influence Of Pcb-Contaminated Water Bodies On The Pcb Content Of Riparian Vegetation Through Foliar Deposition, Timothy Matthew Sattler

All Theses

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are generally considered semi-volatile. Volatilization and transport of PCBs from contaminated water bodies can result in PCB accumulation on terrestrial plant surfaces, acting as an entry point for contaminants into terrestrial food webs. Evergreen plants can serve as biomonitors of this PCB accumulation, as they often retain foliage for several years, allowing for greater concentrations to accumulate and subsequently be measured. Rhododendron maximum plants often grow in the riparian zone adjacent to water bodies in the Appalachian region, such as near Town Creek, Pickens, South Carolina. This research aimed …

Investigating The Feasibility Of Growing Algae For Fuel In Southern Nevada, Faegheh Moazeni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microalgae capable of growing in waste are adequate to be mass-cultivated for biodiesel, avoiding fertilizers and clean water, two obstacles to sustainability of the feedstock production. This study replaces fertilizers and clean water with waste products. The investigated wastes include (1) the liquid fraction of sewage after solids and particles are removed, known as centrate, and (2) algal biomass residue, i.e. the algae remaining at the end of the lipids extraction process at biofuel plants. These wastes contain sufficient amount of nitrogen and phosphorus required for algal growth. This study proposes a system in which centrate would be used as …

Design And Fabrication Of Nanofluidic Systems With Integrated Sensing Electrodes For Rapid Biomolecule Characterization, Taylor Bradley Busch

Graduate Theses and Dissertations

A transparent nanofluidic system with embedded sensing electrodes was designed and fabricated by integrating Atomic Force Microscopy (AFM) nanolithography, Focused Ion Beam (FIB) milling and metal deposition, and standard microfabrication processing. The fabrication process started with the evaporation of chrome/gold (Cr/Au) onto a Pyrex 7740 wafer followed by photolithography and wet etching of the microchannels. The wafer was patterned a second time to form Au microelectrodes with 15-45 micrometer separation gaps in the nanochannel region. Sensing electrodes (up to one micron wide) were then deposited using FIB to bridge the gaps. The nanochannels were realized through both AFM nanolithography and …

Design And Fundamental Understanding Of Minimum Quantity Lubrication (Mql) Assisted Grinding Using Advanced Nanolubricants, Parash Kalita

Graduate Theses and Dissertations

Abrasive grinding is widely used across manufacturing industry for finishing parts and components requiring smooth superficial textures and precise dimensional tolerances and accuracy. Unlike any other machining operations, the complex thermo-mechanical processes during grinding produce excessive friction-induced energy consumption, heat, and intense contact seizures. Lubrication and cooling from grinding fluids is crucial in minimizing the deleterious effects of friction and heat to maximize the output part quality and process efficiency. The conventional flood grinding approach of an uneconomical application of large quantities of chemically active fluids has been found ineffective to provide sufficient lubrication and produces waste streams and pollutants …

Improvements In Microdialysis Sampling Extraction Efficiency Using Recycled Flow, Justin Cole Deaton

Graduate Theses and Dissertations

Incomplete recovery during microdialysis sampling is hindering important research in neurology, proteomics, and immunology. Although the current generalized solution, decreasing volumetric flow rates (Q), has been and will remain to be a useful strategy it has reached it's a physical limitation due to evaporation at the collection site. Consequently, many important signaling molecules, such as signaling proteins, remain difficult to study. It is more fundamental to consider relative recovery as a function of the interaction time between the perfusate and the environment surrounding the probe.

In this work an increase in relative recovery was predicted by a mathematical model. Using …

Glycerin And The Market, Valentine Chijioke Mbamalu

Masters Theses and Doctoral Dissertations

Glycerin, a trihydric alcohol, had once enjoyed a good market value but, is now faced with global oversupply and this makes the market volatile. It is a byproduct of biodiesel production thought as an added value to biodiesel operations. It is now faced with an unpredictable market and probably oversupply as an outcome of increased biodiesel production. There are two types of glycerin market; the refined glycerin with its solid price and crude glycerin which is volatile. There are new applications for glycerin being developed or being implemented and it will be a source of strength to the market. This …

Magnetic Manipulation Of Particles And Cells In Ferrofluid Flow Through Straight Microchannels Using Two Magnets, Jian Zeng

All Theses

Microfluidic devices have been increasingly used in the past two decades for particle and cell manipulations in many chemical and biomedical applications. A variety of force fields have been demonstrated to control particle and cell transport in these devices including electric, magnetic, acoustic, and optical forces etc. Among these particle handling techniques, the magnetic approach provides clear advantages over others such as low cost, noninvasive, and free of fluid heating issues. However, the current knowledge of magnetic control of particle transport is still very limited, especially lacking is the handling of diamagnetic particle. This thesis is focused on the magnetic …

The Effect Of Packaging Material Properties On Consumer Food Quality Perception In Quick-Service Restaurants, Emily Thackston

All Theses

The majority of menu items available in quick-service restaurants (QSR) are consumed directly from a container or package. The main reasons consumers choose to eat fast food are because it is convenient, prepared quickly, a good value, and inexpensive. Therefore, the packaging becomes an integral part of the food product and from a consumer perspective must be consistent with their expectations and motives for choosing to eat fast food. Prior research has directly linked characteristics of consumer food packaging experience to their perception of its contents. The purpose of this research is to determine if consumer quality perception of food …

Broadband Enhancement Of Spontaneous Emission From Nitrogen-Vacancy Centers In Nanodiamonds By Hyperbolic Metamaterials, Mikhail Y. Shalaginov, Satoshi Ishii, J. Liu, Joseph Irudayaraj, A. Lagutchev, Alexander V. Kildishev, Vladimir M. Shalaev

Birck and NCN Publications

We experimentally demonstrate a broadband enhancement of emission from nitrogen-vacancy centers in nanodiamonds. The enhancement is achieved by using a multilayer metamaterial with hyperbolic dispersion. The metamaterial is fabricated as a stack of alternating gold and alumina layers. Our approach paves the way towards the construction of efficient single-photon sources as planar on-chip devices. (C) 2013 AIP Publishing LLC.

Chemoelectromechanical Actuation In Conducting Polymer Hybrid With Bilayer Lipid Membrane, Hao Zhang

Theses and Dissertations

Biological and bio-inspired systems using ion transport across a membrane for energy conversion has inspired recent developments in smart materials. The active mechanism in bioderived materials is ion transport across an impermeable membrane that converts electrochemical gradients into electrical and mechanical work. In addition to bioderived materials, ion transport phenomenon in electroactive polymers such as ionomeric and conducting polymers produces electromechanical coupling in these materials. Inspired by the similarity in transduction mechanism, this thesis focuses on integrating the ion transport processes in a bioderived material and a conducting polymer for developing novel actuation systems. The integrated membrane has a bilayer …

Liquefaction Of Mine Tailings, Vijay K. Puri, Todd R. Kostecki

International Conference on Case Histories in Geotechnical Engineering

Liquefaction of mine tailings is known to occur during cyclic, quasi-static & static loading cases but is still a relatively misunderstood concept because tailings dam failures continue to occur. In the worst case scenario the results are high costs, hindered public perception, environmental cleanup and worst of all, the loss of life. A better understanding of this issue is essential for any engineer associated with the mining and/or geotechnical industry, and in particular tailings dam construction and maintenance. This paper presents the liquefaction concept, some case histories dealing with failure of mine tailings dams, available testing methods and some dated …

Closure And Post-Closure Redevelopment Of The Mccoll Superfund Site, Edward Kavazanjian Jr.

International Conference on Case Histories in Geotechnical Engineering

The McColl Superfund site was one of the highest-profile hazardous waste sites in the USA in the 1980’s. The 12 unlined pits containing refinery waste from World War II presented unique challenges for closure construction and post-closure redevelopment due the caustic nature, low bearing capacity, and high odor potential of the waste, the proximity of residences, and a mandate to restore portions of a golf course over several of the pits. Closure design included special testing to demonstrate the durability of materials that could potentially come in contact with the waste and to evaluate the potential for migration of waste …

The Use Of High Strength Geosynthetics In Deep Soil Mixed Levee Foundations, Brian C. Baillie

International Conference on Case Histories in Geotechnical Engineering

The construction and design of flood protection embankment levees within coastal areas has become a focal point for infrastructure management. The levees are usually constructed over soils with very poor bearing capacity due to their proximity to flood plains. The foundation soils create issues with long-term settlement, changing the protection height and creating the need to periodically build the levee back to the design height. In order to reduce settlements and the maintenance required to preserve design height protection, a deep foundation is needed for proper long term load transfer. Deep soil mixing (DSM) has become a popular deep foundation …

A Comprehensive Model For Anaerobic Degradation In Bio-Reactor Landfills, Jay N. Meegoda, S. Bhuvaneshwari, P. A. Hettiaratchi, H. Hettiarachchi

International Conference on Case Histories in Geotechnical Engineering

A new generation of sustainable landfill was designed and constructed in the City of Calgary, Canada to achieve sustainable municipal solid waste (MSW) management. This sustainable landfill called “biocell” involves sequential operation of a landfill cell to produce methane gas during the first stage of anaerobic degradation and in-situ composting within the cell footprint. Once methane recovery is minimal, the second stage aerobic degradation initiated by injecting air through methane recovery system and finally landfill is mined for resource and space recovery in the third stage. The resources that can be recovered include compost like material and recyclables such as …

Compaction Grouting For Seismic Retrofit Of The North Torrey Pines Bridge, James R. Gingery, Sunil Arora

International Conference on Case Histories in Geotechnical Engineering

The North Torrey Pines Road Bridge in Del Mar, California was built in 1933 and is eligible for listing in the National Register of Historic Places. As a result of its outdated design and deterioration in a corrosive saline environment, the bridge was classified as structurally and seismically deficient and functionally obsolete. The historic significance of this bridge is important to the surrounding community and thus a seismic retrofit project was initiated with the goal of improving the expected seismic performance of the bridge while preserving its aesthetic and historic character. This paper provides a brief description of the overall …

Investigation On Geosynthetic Reinforced Two Layered Soil System, P. B. Ullagaddi, T. K. Nagaraj

International Conference on Case Histories in Geotechnical Engineering

Use of geosynthetics for flexible pavements founded on expansive soil subgrade is one of feasible and economic solution to minimize the undulation and required pavement thickness. In this present investigation the effect of inclusion of the geosynthetic reinforcement on California Bearing Ratio (CBR) value of a two layered soil system with black cotton soil at bottom and granular soil at top as a buffer layer, with different thickness configuration and geotextiles of different physical and mechanical properties was studied by laboratory and field California bearing ratio tests. Thickness of flexible pavement over the two layer soil system of different thickness …

Simulation Of Inorganic And Organic Contaminants Transport In Sanitary Landfills, R. P. Singh

International Conference on Case Histories in Geotechnical Engineering

The modelling of leachate generation and transport is important for estimating the possible groundwater pollution below the sanitary landfills. The numerical solution of the mathematical models for the total solids (inorganic) and chemical oxygen demand (organic) transport is presented. The existing one dimensional leachate transport model which accounts for advection and diffusion is modified with the addition of desorption term and the simulation results are compared for different case studies from the literature. The maximum error is reduced to 28.24 % with modified inorganic model against 38.93 % with the existing model for the TS concentration when simulated with literature …

Stabilization Of Contaminated Soil By Dicalcium Phosphate, Amin Falamaki, Hossein Tavallali, Sharbanoo Rezanejad Farahmand

International Conference on Case Histories in Geotechnical Engineering

Stabilization of heavy metals contaminated soils using phosphate amendments is relatively a simple, quick and cheap method to reduce the transport of contaminants in the environment. The objective of this study is to stabilize the polluted soil using dicalcum phosphate (DCP). In this study a series of leachate column tests were conducted to find out the effect of DCP on Pb and Cu polluted soil. In addition, to understand the concentration of DCP on the efficiency of the method, different samples with different polluted soils were tested. DCP with 0.1, 0.2 and 0.5 mg/kg dry soil were added to the …

Fabrication And Localized Surface Plasmon Resonance Of Ultrathin Nanoporous Gold Films, Shi Feng, Shu Chen, Qing Yang, Juan Xiang

Journal of Electrochemistry

Ultrathin nanoporous gold films (NPGF) with a thickness of approximately 50 nm were fabricated via electrochemical dealloy method. The morphology of NPGF was evaluated with a parameter of surface roughness. SEM results demonstrate that the fabrication of NPGF with different roughness factors can be achieved by controlling the circles of cyclic voltammetry. UV-Vis spectra indicate that the localized surface plasmon resonance (LSPR) of NPGF is affected by the roughness of NPGF. With the optimal roughness factor, NPGF displays a linear relationship between the ethanediol concentration and the absorbance intensity at λ = 450 nm. The LSPR effect of NPGF presents …

Mimicking The Mechanical Behavior Of Advancing Disc Degeneration Through Needle Injections, Jeremy S. Alsup

Theses and Dissertations

Objective - To investigate the effects of injected protease solution on the mechanical advancement of disc degeneration, and to establish test protocol for future pre-clinical validation of spinal arthroplasty devices. The hypothesis that injection of a protease into a cadaveric lumbar disc will mimic advanced degeneration mechanics was the subject of this study. Summary of Background Information - Spinal disc degeneration is a universal condition that progresses in adults due to aging, disease, or injury. Stages of disc degeneration have been categorized in cadaver specimens, with each degeneration level exhibiting characteristic changes in flexibility parameters. Spinal disc tissue can be …

Modification Of Nanostructures Via Laser Processing, Louis Franzel

Theses and Dissertations

Modification of nanostructures via laser processing is of great interest for a wide range of applications such as aerospace and the storage of nuclear waste. The primary goal of this dissertation is to improve the understanding of nanostructures through two primary routes: the modification of aerogels and pulsed laser ablation in ethanol. A new class of materials, patterned aerogels, was fabricated by photopolymerizing selected regions of homogeneous aerogel monoliths using visible light. The characterization and fabrication of functionally graded, cellular and compositionally anisotropic aerogels and ceramics is discussed. Visible light was utilized due to it’s minimal absorption and scattering by …

2013 - The Eighteenth Annual Symposium Of Student Scholars

Symposium of Student Scholars Program Books

The full program book from the Eighteenth Annual Symposium of Student Scholars, held on April 25, 2013. Includes abstracts from the presentations and posters.

The Mechanotransduction Of Primary Cilia In Tumor Progression Of Lung Adenocarcinoma, Sagar Patel

Theses and Dissertations

The objective of this study was to investigate primary cilia and their mechanotransduction role in lung adenocarcinoma tumor progression. The main focus investigated the effect of primary cilia on cell cycle progression, survival, adhesion and migration analysis of these cells and the role of sonic hedgehog signaling pathway in mechanotransduction. Human Non-Small Cell Lung Cancer (NSCLC) adenocarcinoma biopsies contain more primary cilia than non-tumor lung sections. To observe the effects of primary cilia presence in lung cancer cells in-vitro, formation of primary cilia is inhibited using small interfering RNA. A549 cells with intact primary cilia observe less cell cycle progression …