Engineering Commons^™

Protein Isolation Using Peptoid Based Affinity Chromatography, Megan Dunn

Chemical Engineering Undergraduate Honors Theses

Protein purification is essential for advancements in biotechnology. There are several different methods employed in purifying a particular protein from a complex sample such as a cell lysate. These methods take advantage of differences in the size, charge or binding affinity of the protein. One such method is affinity chromatography which utilizes the binding affinity of a protein toward a certain ligand to purify a protein. This is usually used as a final step to extract the desired protein after the mixture has undergone other purification steps to remove unwanted materials. The goal of this project was to develop a …

Novel Method For Sequential Batch Recovery Of Biomass From A Helical Photobioreactor, Matthew Hurst

Chemical Engineering Undergraduate Honors Theses

This study developed and evaluated a novel method to recover the microalgae species Arthrospira platensis from a closed helical photo bioreactor system. A recovery apparatus was designed and shown to increase recovery by 40% via periodic online recovery runs during exponential growth phase of biomass. Considerations for the apparatus design included the low shear tolerance of the algae and the necessity for a closed system in order to monitor CO2 consumption. The recovery method draws on methods used for large scale recovery as reported in literature by Vonshak and Shimmatsu [1], [2]. This work seeks to improve reactor biomass yield …

The Effect Of The Local Refractive Index On The Spectral Properties Of Gold Nanoparticle Arrays, Justin Norman

Chemical Engineering Undergraduate Honors Theses

Gold nanoparticle arrays exhibit extraordinary spectral properties useful to a wide variety of applications including biomolecular sensing, alternative energy, and informatics. The spectral properties of these arrays depend on the array geometry (particle size and spacing) and the surrounding environment (refractive index). In this thesis, a thorough map of the parameter space describing the spectral properties of square, gold nanoparticle arrays is developed in conjunction with a fundamental theoretical description of the phenomena that govern these properties.

Hydrocarbon Removal, Elizabeth Ashley

Chemical Engineering Undergraduate Honors Theses

A group of Chemical Engineers romoved hydrocarbons from a surrogate flowback solution. The solution contained polar and non-polar hydrocarbons that had to be removed to protect an RO membrane. The full scale solution would use UF to remove the non-polar hydrocarbons and GAC beds to remove the soluble hydrocarbons.

Optimal Production Of Biobutanol Via Hydrogenation Of Butyric Acid, Sarad Panta

Chemical Engineering Undergraduate Honors Theses

Butanol is a primary alcohol most commonly used industrially as a solvent. It is largely produced petrochemically using fossil fuel feedstocks. The global butanol market has steadily increased in recent years and is projected to continue increasing at an annual rate of 3.2%. Additionally, the possibility of introducing butanol to the fuel market presents the opportunity to further grow the industry. Because of the increasing demand and its production from fossil fuels, there is a need to manufacture butanol more sustainably and efficiently to help the environment and improve the world economy. Currently, biobutanol is not produced commercially; however, its …

Hollow Fiber Ultrafiltraion And Granulated Activated Carbon Hydrocarbon Removal For Reverse Osmosis Pretreatment, Hayden Dwyer

Chemical Engineering Undergraduate Honors Theses

Hydraulic Fracturing is becoming an increasing prevalent technology in present society due its ability to produce cheap, clean natural gas as a viable fuel source. One public image draw back to hydraulic fracturing, however, is that it uses large volumes of water. This water returns to surface after stimulation laden with hydrocarbons and other material from down hole. The proposed and test method to treat this flowback water was reverse osmosis membranes with granulated activated carbon and ultrafiltration serving as a pretreatment. This proved to be a very successful method in treating hydraulic fracturing flowback water.

Analysis Of Aggregate Distribution In Self-Consolidating Concrete, Brendan Ho

Civil Engineering Undergraduate Honors Theses

Concrete consists of several key ingredients: cement, water, and coarse and fine aggregate. Depending on the proportions of these ingredients, the strength and workability of a concrete mix can be affected adversely. Segregation is the separation of aggregate and cement paste, resulting in a lack of homogeneity. Self-consolidating concrete (SCC) does not require traditional consolidation; however, it can be affected by segregation. This project examines different SCC mixtures and establishes ranges of values for slump flow, T20 , Visual Stability Index (VSI), J-ring flow and J-ring flow spread that ensures proper aggregate distribution and therefore reduces the potential of segregation. …

Internal Curing Using Lightweight Fine Aggregate, Jonathan Kerby

Civil Engineering Undergraduate Honors Theses

Curing refers to the process of maintaining the hydration of the concrete as it hardens, or sets up. Concrete is cured to prevent things such as cracking and shrinkage. Autogenous shrinkage occurs internally in concrete because there isn’t enough water in the concrete for hydration, so the concrete rapidly draws out water to complete the hydration cycle, causing internal drying of concrete. There are two types of curing: external and internal. External curing utilizes water from external sources such as saturated burlap mats, ponding, or fogging. Internal curing supplies water from an internal source inside the concrete, such as saturated …

An Experimentally Generated Constitutive Model For Peak Stress (Σ_Peak) In Compression Samples, Kevin Mathew Lopez Galang

Master's Theses

The hot working behavior of AISI 1018 steel was studied by hot-compression deformation tests on the Gleeble 1500 thermo-mechanical simulator at true strain values of -0.143 and -0.405, true strain rate values of 0.01 and 0.1, and working temperatures of 900^°C and 1000°C. The tests show that a lower working temperature and lower true strain value results in a greater maximum compressive force. The apparent activation energy Q_app was calculated by using the Zener-Hollomon parameter combined with the low stress law. Q_{app ­}was calculated to be 311 kJ mol^-1 K^-1.

Voltage Stability Analysis Using Simulated Synchrophasor Measurements, Allan Agatep

Master's Theses

An increase in demand for electric power has forced utility transmission systems to continuously operate under stressed conditions, which are close to instability limits. Operating power systems under such conditions along with inadequate reactive power reserves initiates a sequence of voltage instability points and can ultimately lead to a system voltage collapse. Significant research have been focused on time-synchronized measurements of power systems which can be used to frequently determine the state of a power system and can lead to a more robust protection, control and operation performance. This thesis discusses the applicability of two voltage stability synchrophasor-based indices from …

Transient Small Wind Turbine Tower Structural Analysis With Coupled Rotor Dynamic Interaction, George R. Katsanis

Master's Theses

Structural dynamics is at the center of wind turbine tower design - excessive vibrations can be caused by a wide range of environmental and mechanical sources and can lead to reduced component life due to fatigue, noise, and impaired public perception of system integrity. Furthermore, periodic turbulent wind conditions can cause system resonance resulting in significantly increased structural loads. Structural vibration issues may become exacerbated in small wind applications where the analytical and experimental resources for system verification and optimization are scarce. This study combines several structural analysis techniques and packages them into a novel and integrated form that can …

Modeling And Analysis Of A Dynamic Voltage Regulator, Timothy David Haskell

Master's Theses

Increased government funding and incentives in recent years has led to an increase in the number of grid-tied renewable energy sources as their economic benefits become more renowned. Unfortunately, the outputs of these renewable resources are often highly variable, resulting in undesirable voltage disruptions that are harmful to sensitive loads. In addition to the energy variability of renewable energy sources, random voltage sags, swells and disruptions are already a major issue in power systems. Recent advances in power electronic devices have provided a platform for new solutions to the voltage support problem in power systems. One promising solution is the …

Modeling And Analysis Of A Pv Grid-Tied Smart Inverter's Support Functions, Benjamin Anders Johnson

Master's Theses

The general trends in the past decade of increasing solar cell efficiency, decreasing PV system costs, increasing government incentive programs, and several other factors have all combined synergistically to reduce the barriers of entry for PV systems to enter the market and expand their contribution to the global energy portfolio. The shortcomings of current inverter functions which link PV systems to the utility network are becoming transparent as PV penetration levels continue to increase. The solution this thesis proposes is an approach to control the inverters real and reactive power output to help eliminate the problems associated with PV systems …

Modeling The Zimmer Fitmore And Ml Taper Implantation, Tyler Kazuo Franklin

Master's Theses

With more young adults requiring total hip

arthroplasties the need for bone saving implants becomes

more important. The Zimmer Fitmore is a new bone saving

implant that utilizes an implantation technique that

reduces the damage to the muscle tissue allowing for

patients to have a short recovery time as well as a new

design that allows it to rest on the medial cortex. There

has been anecdotal evidence that this device leads to early

revision within six months of implantation due to failures

occurring in the medial cortex. The main goal of this

study was to computationally model the Zimmer …

Categorization Of Security Design Patterns, Jeremiah Y. Dangler

Electronic Theses and Dissertations

Strategies for software development often slight security-related considerations, due to the difficulty of developing realizable requirements, identifying and applying appropriate techniques, and teaching secure design. This work describes a three-part strategy for addressing these concerns. Part 1 provides detailed questions, derived from a two-level characterization of system security based on work by Chung et. al., to elicit precise requirements. Part 2 uses a novel framework for relating this characterization to previously published strategies, or patterns, for secure software development. Included case studies suggest the framework's effectiveness, involving the application of three patterns for secure design (Limited View, Role-Based Access Control, …

Surveillance Planning Against Smart Insurgents In Complex Terrain, Nabil Lehlou

Graduate Theses and Dissertations

This study is concerned with finding a way to solve a surveillance system allocation problem based on the need to consider intelligent insurgency that takes place in a complex geographical environment. Although this effort can be generalized to other situations, it is particularly geared towards protecting military outposts in foreign lands. The technological assets that are assumed available include stare-devices, such as tower-cameras and aerostats, as well as manned and unmanned aerial systems. Since acquiring these assets depends on the ability to control and monitor them on the target terrain, their operations on the geo-location of interest ought to be …

Bio-Separation Process Improvement Via Genomic Manipulation: Development Of Novel Strains For Use In Immobilized Metal Affinity Chromatography (Imac), Ryan Curtis Haley

Graduate Theses and Dissertations

The dissertation is comprised of three parts. Part I describes proteomic analysis of native bacterial proteins from Escherichia coli (E.coli) that bind during Immobilized Metal Affinity Chromatography (IMAC). Part II describes the value in exploiting proteome based data as a tool toward the design an E. coli expression strain that is particularly useful when Immobilized Metal Affinity Chromatography is employed as the initial capture step of a homologous protein purification process. Part III describes a methodology of chromosomal mapping of all contaminant gene products.

The objective of Part I was to identify all E. coli proteins that bind to Co(II), …

Improving Virtual Collaboration: Modeling For Recommendation Systems In A Classroom Wiki Environment, Derrick A. Lam

School of Computing: Dissertations, Theses, and Student Research

Collaboration is of increased importance in today’s society, with increased emphasis placed on working jointly with others, whether it is in the classroom, in the lab, in the workplace, or virtually across the world. The wiki is one particular virtual collaboration tool that is gaining particular prominence in recent years, enabling people – either in small project groups or as part of the wiki’s entire user base – to socially construct knowledge asynchronously on a wide variety of topics. However, there are few intelligent support tools for wikis available, particularly those providing recommendation-based support to users.

This thesis investigates the …

Ultrasonic Pulse Velocity Investigation Of Steel Fiber Reinforced Self-Compacted Concrete, Belayhun Tesfaye Gebretsadik

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concrete is a basic material used for a number of applications in civil engineering projects. Structural concrete is brittle material under normal conditions. Therefore, by adding short and randomly distributed steel fibers, it is possible to improve the ductility and other basic properties of concrete. However, the addition of steel fibers results in loss of workability of the concrete, especially in self-compacted concrete. Therefore, in this study, ADVA-140 high range water reducer (HRWR) superplasticizer was added to improve the workability of self-compacted (SC), steel-fiber-reinforced concrete (SFRC). The amount of superplasticizer varied with the volume percentage of fiber for the beams; …

Predicting The Performance Of A Solar Domestic Water Heating System With Evacuated Tube Collectors And Hydronic Radiant Flooring, Kimberly Nicole Hammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Residential solar thermal system installations have been significantly increasing in the last decade and there exists limited resources for reasonably predicting the performance of those systems. A simulated model is developed in MATLAB® and used to predict the performance of a solar domestic water heating system. In the simulated system, hot water is generated using evacuated tube solar collectors and stored in a domestic hot water storage tank, which utilizes immersed coil heat exchangers. The system is designed to provide hydronic radiant floor heating to its occupants based on the heat loss of a building energy model for an energy-efficient …

Hazard Classification And Hydraulic Remediation Options For Flat-Topped And Ogee-Crested Low-Head Dams, Riley J. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The dangerous hydraulic conditions that can form downstream of a low-head dam were investigated. These dangerous hydraulic conditions have been the cause of hundreds of drowning incidents since the construction of the first low-head dams. Two primary objectives were identified for this study, each of which were primarily performed using the Computational Fluid Dynamics software, Flow-3D^®, with physical models used to verify the numerical results. The first objective was the identification of a risk factor made up of easily measured parameters that could accurately predict when the dangerous hydraulic conditions are present at a low-head dam. The risk …

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 …

Finite Element Analysis Of The Nerve Cuff To Determine Usability And Stress Analysis During Regular Use, Vivek Machhi

Biomedical Engineering

To determine the stress analysis on the Nerve Cuff by MicroProbes, a finite element analysis was conducted. A simplified model was created in Solid Works using the geometry of the basic model of the nerve cuff. The solid model was then imported into Abaqus and the appropriate materials, boundary conditions, and loads were designated. Initially a tensile test simulation was conducted using a tensile force of 2.87 Newtons. The maximum stress experienced with this tensile force was 8.225 MPa which was greater than the ultimate tensile strength of 5.5 MPa of Silicone. Both the actual tensile test and the tensile …

Design Of Experimental Methods To Test The Performance Of Pads And Helmets Under Blast Loading Conditions, Kurtis Palu

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Improvised explosive devices (IEDs) have become a primary weapon in conflicts against US and allied forces. Improvements in body armor and medicine have increased the survivability of such events. These factors have caused an increase in traumatic brain injury (TBI) and mild traumatic brain injury (mTBI) induced by primary blast waves. Injury mechanisms caused from primary blast waves are not clearly understood or defined. How primary blast waves interact with materials or between narrow gaps found between helmet pads is not known. Two novel test fixtures were developed to provide a basic understanding of these two issues.

The first fixture …

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, …

Prediction Of Subsurface Damage During Machining Nickel-Based Superalloys, Yujie Chen

All Dissertations

Nickel-based superalloys are widely utilized in hostile environments such as jet engines and gas turbines due to their high resistance to oxidation, high corrosion resistance, good thermal fatigue-resistance and fracture toughness. Subsurface damage is typically generated during the machining of these materials, and in particular, ã'-strengthened nickel-based superalloys. The depth of the subsurface damage is a critical requirement specified by the customer. Therefore, it is critical to predict, measure and control subsurface damage.
This research specifically targets the development of a model to predict subsurface damage during the machining of ã'-strengthened nickel-based superalloys. To accomplish this, a modified Johnson-Cook model …

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 …

Glass-Clad Semiconductor Core Optical Fibers, Stephanie Morris

All Dissertations

Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine.
As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in …

Prediction Of Discrete Element Parameters For Modeling The Strength Of Sandy Soils In Wheel/Soil Traction Applications, Timothy Reeves

All Dissertations

The problem of wheel performance on deformable soil has been studied for many years, but prior to the rise of computational mechanics, such investigations have been limited to development of analytical and empirical models, as well as experimental research. Such models have merit but are necessarily highly idealized and are limited in their applications. Today, many computational models have been implemented for a wide variety of wheel/soil applications.
For the specific case of sandy (i.e. non-cohesive) soils, in terms of the soil's physics the Discrete Element Method (DEM) provides arguably the most realistic model. In DEM, each element represents a …

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 …