Engineering Commons^™

An Extension To Particle Polarizability To Predict Coupling Behavior In Periodic Nanoplasmonic Arrays, Drew Dejarnette

Graduate Theses and Dissertations

Plasmonic nanoparticles organized in arrays interact to create spectral patterns which are amplified by individual particle polarizability. It was hypothesized that particle polarizability could be used as a predictor of spectral behavior from far-field interactions within the array. Inter-particle coupling produced an extraordinary peak in extinction efficiency at wavelengths equal to or larger than the single particle plasmon resonance peak. Interactions that produced constructive coupling were found to mimic changes in the particle polarizability model. Testing of the hypothesis was performed using the coupled dipole approximation with parametric characterization of array geometries, giving specific particle size and lattice constant combinations …

Upper Extremity Biomechanical Model For Evaluation Of Pediatric Joint Demands During Wheelchair Mobility, Alyssa J. Paul, Brooke A. Slavens, Adam Graf, Joseph Krzak, Lawrence Vogel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Current methods for evaluating upper extremity (UE) dynamics during pediatric wheelchair use are limited. We propose a new model to characterize UE joint kinematics and kinetics during pediatric wheelchair mobility. The bilateral model is comprised of the thorax, clavicle, scapula, upper arm, forearm, and hand segments. The modeled joints include: sternoclavicular, acromioclavicular, glenohumeral, elbow and wrist. The model is complete and is currently undergoing pilot studies for clinical application. Results may provide considerable quantitative insight into pediatric UE joint dynamics to improve wheelchair prescription, training and long term care of children with orthopaedic disabilities.

Storage And Loss Moduli Of Bone In Osteogenesis Imperfecta (Oi), Carolyne Albert, John Jameson, Jeffrey Toth, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Understanding The In Vivo Uptake Kinetics Of A Phosphatidylethanolamine-Binding Agent 99mTc-Duramycin, Said H. Audi, Zhixin Li, Joseph Capacete, Yu Liu, Wei Fang, Laura G. Shu, Ming Zhao

Biomedical Engineering Faculty Research and Publications

Introduction

^99mTc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between ^99mTc-Duramycin and the target tissue.

Methods

High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in Sprague–Dawley rats. Target binding and biodistribution of ^99mTc-duramycin were captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of …

Deformation And Adhesion Of Thin Metallic Films On Flexible Substrates, Julia Reid

All Theses

Flexible electronics are conductive circuits, components and lines integrated onto elastic substrates. These systems often consist of metallic thin films deposited onto thin sheets of glass, metals stainless steel or polymeric materials such as polyethylene or polystyrene. These systems are currently being studied for a wide variety of aeronautic and astronautical applications including: electronic skins, solar sails, and antennae structures. For applications include only moderately elevated temperatures (near 200 ¡C) and low strains (insert range), engineers have proposed incorporation metallic lines onto polymeric substrates. Like traditional microelectronic systems with films on hard substrates, the reliability is controlled by the film-substrate …

An Electromagnetic Energy Harvester For Powering Consumer Electronics, Xiyuan Liu

All Theses

This thesis introduces an electromagnetic vibratory energy harvester to power consumer electronics by generating electricity from the strides taken during walking or jogging. The harvester consists of a magnetic pendulum oscillating between two fixed magnets. The pendulum behaves similar to a rotor in a DC generator, while the fixed magnets, which are poled opposite to the pendulum, provide magnetic restoring forces similar to mechanical springs. When attached to a person's arm, the swinging motion subjects the magnetic pendulum to base excitations. Consequently, the pendulum oscillates near a stator which has three poles of wound copper coils. The motion of the …

Optimization Of Processing Parameters For As2se3 Glass For Low Loss, High Strength Fibers, Baptiste Giroire

All Theses

Chalcogenide glasses have been widely studied due to their extraordinary transparency in the infrared (IR) region from 0.5 to 20 μm. This transparency combined with excellent thermo-mechanical properties, makes them ideal candidate for infrared optics including IR fiber optic applications. However, such non-oxide glasses generally exhibit low mechanical strength, as compared to their oxide counterpart, which are based on covalently bonded metal-oxygen species. In addition to mechanical robustness, low optical loss (hence low impurity content) is required for most IR optical materials, including the one in this study, amorphous arsenic tri-selenide, As2Se3. In this effort, As2Se3 glass was investigated and …

Numerical And Reliability Analysis Of Gravity Cantilever Retaining Walls Backfilled With Shredded Tires Subjected To Seismic Loads, Eleanor Huggins

All Theses

Shredded tires have been considered as a suitable alternative to conventional sand and gravel backfill materials as they offer benefits from their significantly lower unit weight, reductions in the cost of materials and construction, and because they utilize a common and potentially hazardous waste material. This research addresses some gaps in previous research in the implementation of shredded tires in this capacity by examining variation in material properties through a reliability analysis, developing an improved design technique for retaining walls tailored to shredded tire fills, and simulating how shredded tire backfill behaves in conjunction with retaining walls when subject to …

Load Carrying Capacity Assessment Of A Masonry Dome, Tun Li

All Theses

This thesis first establishes a semi-empirical relationship to estimate the reduction in load carrying capacity of a masonry dome due to damage by exploiting deviations in the fundamental natural frequency. A macro finite element model of the dome is developed and calibrated using both non-destructive vibration measurements and destructive load-displacement measurements up to failure. The macro-model is then executed to simulate incremental development of cracks. The first natural frequency and remaining load carrying capacity of the dome are monitored to define a semi-empirical relationship, which is ultimately generalized for spherical domes with varying span-to-height ratios.
Subsequently, in order to numerically …

Fault Analysis Of An Unbalanced Distribution System With Distributed Generation, Parimal Saraf

All Theses

In recent years there has been a lot of emphasis on renewable power integration due to environmental issues and to lower the dependence on fossil fuels. The presence of renewable sources in the distribution systems adds complexity to the calculation of the power flows and hence has a direct impact on the short circuit calculations, protection and control. The presence of unbalance in distribution systems worsens the situation since the three phase voltages and currents are no longer equal in magnitude and 120 degrees phase shifted.
This thesis involves a fault study in a 14-bus distribution system with integrated wind …

Determining The Proper Point Size For Display Type On Packaging, Joanna Fischer

All Theses

Through the use of a preference test, the proper point size of display text on a package was evaluated in relation to a package's proportions. The test involved the examination of packaging images displaying the product or brand name in various point sizes by 150 participants who were then asked to choose the option they most preferred. The participants were then provided with a post-survey intended to gather additional information regarding potential preference motives.
The primary purpose of this study was to determine the most preferred display type size of a package based on its relationship with the package's proportions. …

Functionalized Nanoparticles As Removable Coatings For Reverse Osmosis Membranes, Megan Smith

All Theses

Reverse osmosis (RO) desalination is increasingly used to produce potable water throughout the world. Despite their promising abilities, membrane filtration processes are limited by fouling. Fouling is a broad term for organics, inorganics, colloids and organisms that interact physically, chemically, or biologically with the membrane surface, resulting in reduced flux and shortened membrane lifespan. There is potential to create a snakeskin-like barrier between the membrane and foulants by electrostatically binding a coating material to the membrane that can be released by pH manipulation, removing foulants in the process. The feasibility of using functionalized nanoparticles as removable adsorptive coatings on RO …

Vibration And Acoustic Performance Of In-Plane Honeycomb Sandwich Panels, Xiao Gong

All Theses

Sandwich panel structures constructed with cellular honeycomb cores allow for control of acoustic performance due to their ability to optimize effective orthotropic material properties with changes in cell geometry. By modification of topology and geometric parameters of a unit cell, desirable effective properties can be obtained and used to design lightweight structures with reduced vibration and increased sound transmission loss properties. Thus investigating the relation between the geometric configuration of the honeycomb core and vibration and acoustic behavior is important to optimize design of sandwich panels.
In this work, a finite element model is developed in MATLAB to evaluate the …

Oral Delivery Of Peptide Drugs For Mitigation Of Crohn's Disease, Paul Blichmann

All Theses

Protein drugs are typically administered intravenously, but this practice has clear disadvantages such as widespread circulation and swift clearance from the body. Orally delivered protein drugs are not yet available but potentially offer improved distribution, retention, and activity by use of protective matrices and cell-specific targeting. Much work has been done on delayed release formulations for the upper intestine, but there has not been overwhelming evidence of protection of peptides from gastric conditions. In many instances the large intestine may be a better release target due to lower proteolytic activity. Afflictions of the colon such as Inflammatory Bowel Disease and …

Champs-Multizone And Virtual Building For Integrated Building Systems Design And Performance Evaluation, Wei Feng

Mechanical and Aerospace Engineering - Dissertations

The ultimate goal of this research was to develop an integrated framework that facilitates performance-based multi-stage design of buildings and comparison between the performance predicted at the design stage and that monitored at operation stage. Such an integrated framework would not only enable design optimization, but also enable confirmation of design intent or diagnosis of performance deficiency, and thus provide feedbacks for future building design. This dissertation study represents the first step toward this ultimate goal, and had the following specific objectives:: 1) developing a combined heat, air, moisture and pollutant transport model for whole building performance simulation; 2) developing …

Shape Memory Assisted Self Healing (Smash) Polymeric And Composite Systems, Erika D. Rodriguez

Mechanical and Aerospace Engineering - Dissertations

My research aims to develop a novel approach that uses the shape memory (SM) effect to aid self healing (SH) polymeric systems that are able to simultaneously close and re-bond cracks with a single thermal stimulus. This new concept is termed shape memory assisted self healing (SMASH). Additionally, a new type of shape memory termed reversible plasticity shape memory (RPSM) was also developed where both the elastic and plastic deformation found after deformation completely recover upon a thermal stimulation. I aim to utilize a broad range of polymeric and composite systems that include a single phase semi-crystalline system, a single …

An Experimental Study On Thermal Stability Of Biodiesel Fuel, Yiying Zhu

Biomedical and Chemical Engineering – Theses

Biodiesel fuel, as renewable energy, has been used in conventional diesel engines in pure form or as biodiesel/diesel blends for many years. However, thermal stability of biodiesel and biodiesel/diesel blends has been minimally explored. Aimed to shorten this gap, thermal stability of biodiesel is investigated at high temperatures.

In this study, batch thermal stressing experiments of biodiesel fuel were performed in stainless steel coils at specific temperature and residence time range from 250 to 425 °C and 3 to 63 minutes, respectively.

Evidence of different pathways of biodiesel fuel degradation is demonstrated chromatographically. It was found that biodiesel was stable …

Crowdsourcing To Smartphones: Incentive Mechanism Design For Mobile Phone Sensing, Dejun Yang, Guoliang Xue, Xi Fang, Jian Tang

Electrical Engineering and Computer Science - All Scholarship

Mobile phone sensing is a new paradigm which takes advantage of the pervasive smartphones to collect and analyze data beyond the scale of what was previously possible. In a mobile phone sensing system, the platform recruits smartphone users to provide sensing service. Existing mobile phone sensing applications and systems lack good incentive mechanisms that can attract more user participation. To address this issue, we design incentive mechanisms for mobile phone sensing. We consider two system models: the platform-centric model where the platform provides a reward shared by participating users, and the user-centric model where users have more control over the …

Water And Energy Conservation Grow System: Aquaponics And Aeroponics With A Cycle Timer, Roger Hancock

Electrical Engineering

What some experts call the “blue gold”; water is a major issue in this world. There is only so much water and the reliability and cleanliness of water is what many developing countries are dealing with today. Countries around the world are facing problems with reliable water to grow enough food for their villages and homes. Is there is a way to minimize water consumption while optimizing growth in plants for food? One solution can be seen through both Aeroponics and Aquaponics. This project explores the potential of providing larger quantities of food to areas where water may be in …

The Biomechanical Role Of Scaffolds In Augmented Rotator Cuff Tendon Repairs, Amit Aurora, Jesse A. Mccarron, Antonie J. Van Den Bogert, Jorge E. Gatica, Joseph P. Iannotti, Kathleen A. Derwin

Mechanical Engineering Faculty Publications

Background

Scaffolds continue to be developed and used for rotator cuff repair augmentation; however, the appropriate scaffold material properties and/or surgical application techniques for achieving optimal biomechanical performance remains unknown. The objectives of the study were to simulate a previously validated spring-network model for clinically relevant scenarios to predict: (1) the manner in which changes to components of the repair influence the biomechanical performance of the repair and (2) the percent load carried by the scaffold augmentation component.

Materials and methods

The models were parametrically varied to simulate clinically relevant scenarios, namely, changes in tendon quality, altered surgical technique(s), and …

3.5 To 30 Mhz Automatic Antenna Impedance Matching System, William Blodgett

Electrical Engineering

Two-way communications using 3 to 30 MHz, high-frequency (HF) radio, also known as shortwave radio, provides worldwide coverage with no infrastructure required between stations. Amateur or “Ham” radio operators apply this advantage to long distance communications and to provide disaster relief communications. Optimum frequencies for long distance propagation are time-of-day variant necessitating an operating frequency range of 3 to 30 MHz. HF half wave dipole antenna length varies from 15 to 150 ft over this range. Fixed-length antenna impedance varies with frequency due to physical dimension dependent capacitance and inductance. Maximum transmitter to antenna power transfer occurs when the transmission …

L&D Manual Turn Lane Storage Validation/Update, Deogratias Eustace, Sowjanya Ponnada

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Queuing occurs at intersections mostly due to overflow or inadequacy of turn bays. The ODOT L&D Manual Volume 1 has storage requirements for both signalized and unsignalized intersections. Figures 401-9E and 401-10E of the L&D Manual provide the required turn lane storage lengths which should be compared with the real world conditions to check for adequacy of these lengths as a measure of ensuring that accesses to the left turn lanes are not blocked. In addition to the projected turn lane volume, ODOT’s methodology incorporates both deceleration (based on the speed of the roadway) and potential blockage from the adjacent …

En Route Towards Α-Benzotriazoyl Nitroso Derivatives, Jean-Christophe M. Monbaliu, Lucas K. Beagle, Judit K. Beagle, Matthias Zeller, Christian V. Stevens, Alan R. Katritzky

Chemistry Faculty Publications

A new class of geminally-substituted nitroso compounds, i.e., α-benzotriazoyl nitroso derivatives, is presented. These compounds display a rather different behavior than other related nitroso compounds bearing a geminal electron-withdrawing group. An unexpected and spontaneous oxidation to the nitro analog is observed in solution.

Characterization Of An Advanced Neuron Model, Christopher Echanique

HIM 1990-2015

This thesis focuses on an adaptive quadratic spiking model of a motoneuron that is both versatile in its ability to represent a range of experimentally observed neuronal firing patterns as well as computationally efficient for large network simulation. The objective of research is to fit membrane voltage data to the model using a parameter estimation approach involving simulated annealing. By manipulating the system dynamics of the model, a realizable model with linear parameterization (LP) can be obtained to simplify the estimation process. With a persistently excited current input applied to the model, simulated annealing is used to efficiently determine the …

Forecast Of Wireless Communication Technology: A Comparative Study Of Regression And Tfdea Model, Dong-Joon Lim, Timothy R. Anderson, Jisun Kim

Engineering and Technology Management Faculty Publications and Presentations

This study presents a formal comparison of TFDEA with regression model to forecast wireless communication technology. In addition to the data set from the former research, up-to-2011 4G network technologies are added and analyzed. The research was designed to set the point of forecasting in 2001 so that technologies between 2001 and 2011 are to be forecasted using data set between 1979 and 2001. The results from both TFDEA and regression model are compared and discussed. This comparative study can provide forecasters with different aspects between 'best-practice measurement' and 'average practice measurement' and, ultimately, help to select the suitable approach …

Non-Blocking Concurrent Operations On Heap, Mahesh Acharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

We present a non-blocking implementation for the concurrent Heap data structure in the asynchronous shared memory system. The system may be a traditional one with a single processor with multiple threads, or it may be the one with multiple processors each possibly with multiple threads. Our implementation supports readMin, deleteMin, and insert operations on the heap. The deleteMin and insert operations are non-blocking operations, whereas the readMin is wait-free. One easy approach of using a heap in multi-threading environment could be by locking the entire heap before performing any operation. This would make the implementation very slow to have any …

Basic Research On The Characteristics Of A Constricted Pulsed Glow Discharge, Sean Daniel Andersen

UNLV Theses, Dissertations, Professional Papers, and Capstones

In certain plasma discharge experiments, it has been observed that under specific conditions a plasma glow discharge column tends to seek the central location of the discharge electrodes away from the electrode edges and chamber walls. Further, the column appears to have the properties of a stabilized equilibrium plasma pinch in a glow (non-arc-like) state. This is unusual since, normally field enhancements occur on edges resulting in arc-like discharge breakdown. Also, the column of plasma that protrudes from the anode emits highly intense, non-uniform light that is uncharacteristically bright for a glow discharge.

The main purpose of this thesis is …

Waste Heat Utilization In An Anaerobic Digestion System, Brett Boissevain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Anaerobic digestion has great potential as an energy source. Not only does it provide an effective method for waste mitigation, but it has the potential to generate significant quantities of fuel and electricity. In order to ensure efficient digestion and biomass utilization, however, the system must be continuously maintained at elevated temperatures. It is technically feasible to supplement such a system with outside energy, but it is more cost effective to heat the system using only the produced biogas. While there is considerable literature covering the theory of anaerobic digestion, there are very few practical studies to show how heat …

Design And Characterization Of Circularly Polarized Cavity-Backed Slot Antennas In An In-House-Constructed Anechoic Chamber, Mangalam Chandak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Small satellites have become important vehicles for space exploration. One of the challenges on these satellites is their limited surface area, which creates problems in allocating resources for devices such as antennas. Also, an effective satellite communication system often requires circularly polarized antennas. Therefore, integrating cross slot antennas around solar cells to form a multifunctional solar panel is one of the best solutions for small satellites. The cross geometry provides circular polarization and the slot configuration does not compete for any additional surface space. The main goal of this thesis was to design, fabricate, and test such type of slot …

New Methods For Engineering Site Characterization Using Reflection And Surface Wave Seismic Surveys, Susit Chaiprakaikeow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study presents two new seismic testing methods for engineering application, a new shallow seismic reflection method and Time Filtered Analysis of Surface Waves (TFASW). Both methods are described in this dissertation.

The new shallow seismic reflection was developed to measure reflections at a single point using 2-4 receivers, assuming homogeneous, horizontal layering. Two problems commonly encountered in reflection testing are dealt with in this new method. These problems are: phase shifts between the wave source and ground motion; and, loss of high frequency energy. Using approaches to mitigate these problems significantly improved the shape of measured waveforms. However, none …