Engineering Commons^™

A Study Of The U.S. Intrastate Crowdfunding Exemptions, Ahmed Bohliqa

Engineering and Technology Management Faculty Publications and Presentations

The enactment of intrastate crowdfunding exemptions around the United States has built up a lot of excitement. Crowdfunding became a popular phenomenon in the past 15 years for art and design projects. Crowdfunding companies only allowed raising money by receiving donations or loans without giving funders any security interests in the project's company. This is because any potential economic return could turn the transaction into a securities offering subject to the costly federal and state laws and regulations. Nonetheless, crowdfunding has been effective in enabling new innovations and ideas bloom. Intrastate securities crowdfunding might prove to be one of the …

Project Ranking Using Partial Ranks, Jiali Ju, Pei Zhang, Tim R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

A competition was recently held for new elder care technologies and a method was needed for selecting an audience favorite project. Since each of the eight projects received a half hour presentation time slot spread out over a full day, attendance varied significantly with morning projects having a much lower attendance. An algorithm was desired that was robust with respect to varying evaluator. A new algorithm for aggregating ranks from a large number of incomplete judgment was developed and applied to the projects to select a winner. This paper presents the new algorithm, tests the new approach against others in …

Multi-Component Active Source Rayleigh Wave Analysis, Gabriel Gribler

Boise State University Theses and Dissertations

Determining how a building site will respond to earthquake ground shaking plays a critical role in proper construction practices. One critical constraint on how a site responds is the near surface shear wave seismic velocity distribution. One commonly used method for indirectly estimating shear wave velocities is Multichannel Analysis of Surface Waves (MASW), which utilizes a spread of vertical geophones to measure Rayleigh wave dispersion. With this approach, phase velocity vs. frequency dispersion curve picks can be used to estimate shear wave velocities with depth. I investigate the use of two (vertical and horizontal inline) component seismic signals to record …

Random Actuation Pattern Optimization By Genetic Algorithm For Ultrasonic Structural Health Monitoring Of Plates, Pierrot R. Derjany

Doctoral Dissertations and Master's Theses

The objective of this research is to investigate an optimized two-dimensional random pattern of uniformly excited points using the Genetic Algorithm (GA) technique for structural health monitoring. The point excitations generate ultrasonic waves in both isotropic and anisotropic materials that can be effective in diagnosing structural defects. The formed ultrasonic waves can constructively interfere and send out an intense wave beam to a predetermined target. The constructed wave beams can be steered to different directions with variable target distances. In the GA, the cost function is constructed to reduce main lobe beamwidth, eliminate grating lobes and suppress sidelobes’ levels. Mathematical …

Robust Observability, Control, & Economics Of Complex Cyber-Physical Networks, Shaurya Agarwal

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation deals with various aspects of cyber-physical system. As an example of cyber physical systems, we take transportation networks and solve various problems, namely: 1) Network Observability Problem, 2) Network Control Problem, and 3) Network Economics Problem. We have divided the dissertation into three parts which solve these three problems separately. First part of the dissertation presents a novel approach for studying the observability problem on a general network topology of a traffic network. We develop a new framework which investigates observability in terms of flow information on arcs and the routing information. Second part of the dissertation presents …

Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru

UNLV Theses, Dissertations, Professional Papers, and Capstones

Layered structured materials such as transition metal dichalcogenides (TMDs) have gained immense interest in recent times due to their exceptional structural, electrical and optical properties. Recent studies show semiconducting TMDs such as MX₂ (M= Mo, W & X = S, Se) could be used as potential shock absorbing material, which has resulted in extensive studies on structural stability of these materials under the influence of high pressure. Understanding the structural stability of transition metal dichalcogenides (TMDs) such as MoS2, MoSe2, WS2, and WSe2 under high pressure has been very challenging due to contradicting observations and interpretations reported in the …

Fluoride And Phosphate Removal From Industrial And Domestic Wastewaters Using Cerium Chloride, John Michael Gonzales

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of cerium chloride (CeCl3) to remove fluoride and phosphate from waters is addressed in this study. High concentrations of fluoride exist in groundwater especially in developing countries. Consumption drinking water containing high levels of fluoride can lead to serious cases of dental and skeletal fluorosis. Current defluoridation technologies are limited, especially for high levels of fluoride, and are expensive. Industrial wastewaters contribute to the highest fluoride contamination in the world. With the increasing production of electronic materials, the global fluoride concentration and fluoride-contaminated waters have grown tremendously. Excessive discharge of phosphate into the environment promotes eutrophication of lakes …

Development Of A Decision Support Framework For The Planning Of Sustainable Transportation Systems, Pankaj Maheshwari

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the rapid increase in economic development throughout the world, there is stress on the resources used to support global economy, including petroleum, coal, silver, and water. Currently, the world is consuming energy at an unprecedented rate never seen before. The finite nature of such non-renewable natural resources as petroleum and coal puts pressure on the environmental system, and ultimately reduces the availability of resources for future generations. Hence, it is critical to develop planning and operational strategies that seek to achieve a sustainable use of existing natural resources.

With this motivation, this dissertation focuses to develop a decision support …

Reducing Insertion Loss Of Wavelength-Routed Optical Network Based On Microring Resonator Optical Switches, Yunjia Man

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the ever-increasing demand for high-performance computing systems, on-chip interconnection networks, serving as the communication links in multicore architectures, have become the key to the system performance. Compared with bandwidth-limited power-hungry electrical interconnection networks, optical network-on-chip (ONoC) architectures are emerging as a promising alternative to enable future computing performance gains owing to the recent advancements in silicon photonics. One major issue of ONoC is its insertion loss, which is the optical link loss along the waveguide and through the network. Once the optical power budget is established, the maximum insertion loss through the network can be determined. If insertion loss …

Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the …

Cfd Simulation Of Heat Enhancement In Internally Helical Grooved Tubes, Sogol Pirbastami

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat exchanger devices are widely used in industries, air conditioning systems, refrigeration, etc. These devices have a major role in energy conservation; therefore, increasing the performance of heat exchangers helps save energy, costs and materials. The technique to increase the heat transfer performance is called heat augmentation, which can be applied to pipe surfaces and other surfaces which are used in heat exchangers to improve thermal performance. These techniques are categorized into 3 groups: passive, active and compound technique. In this study a helically machined rectangular groove on the inside of a 2.0 m tube with a diameter of 7.1mm …

Geotechnical Surrogates For Sediment Shear Behavior In Southern Nevada, Rinu Ann Samuel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada Department of Transportation design standards for deep foundations, particularly drilled shafts, in the Las Vegas Valley (LVV) may be overly conservative due to the challenges in characterizing strong but difficult-to-sample sediment strata, such as dense gravel, heavily cemented sediments, and mixed materials, which occur commonly in the LVV. Consequently, there is a need for investigating methods to assess the shear behavior of sediments that occur in the LVV in situ in working ranges of stress/strain, with the end goal of improving abilities to predict the capacity of drilled shafts in the LVV. To this end, global correlations of …

3d Obstacle Avoidance For Unmanned Autonomous System (Uas), Lin Zhao

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this thesis is to design a real-time, three-dimensional algorithm, named as the vector mesh (VM) algorithm, for unmanned aerial vehicles (UAV) to generate collision-free motion in indoor or outdoor environments with unknown obstacles. This promising technology can be utilized in both military and commercial applications. The VM approach employs three data reduction phases to compute optimal navigation directions while on-board scanning range sensor continuously updates depth data. In order to develop the VM, vector filed histogram (VFH) which applied in 2D space was first simulated in Matlab. Then a 2D autonomous navigation was implemented on a developed …

Recycling In A Lean Environment, Marylin N. Glass-Hedges

Dissertations

Lean Manufacturing and Green Manufacturing systems co-occur in many manufacturing facilities. This dissertation investigated the relationship between materials recycling—as an important green waste-reduction technique—and lean techniques, and their influence on lean outcomes, specifically 1) if a correlation exists between lean techniques and material recycling, as these two variables also influence lean outcomes; and 2) the mediating effect of materials recycling between lean techniques and lean outcomes. Exploratory factor analysis, confirmatory factor analysis, and structural equation modeling were the chosen statistical analysis methods utilized to explore and confirm the lean techniques and lean outcomes constructs, test the models’ hypotheses and answer …

A Simple Polarization Reconfigurable Printed Monopole Antenna, Afshin Panahi, Xiulong Bao, Kansheng Yang, Oisin O'Conchubhair, Max Ammann

Articles

A simple polarization reconfigurable printed monopole antenna is proposed for wireless applications. Conducting strips are used to connect to the ground plane providing the necessary additional modes for circular-polarization. Linear-polarization, right hand or left hand circular-polarization can be realized using only two PIN diodes, which connect to the ground plane, minimizing their effect on radiation characteristics. The mechanism is described, and key antenna parameters are studied and optimized. The antenna is prototyped and tested for all polarization configurations.

Formal Specification Driven Development, Titus Fofung

Dissertations, Theses and Capstone Projects (Full IR Collection)

This paper researches a quantitative metric of investigating Formal Specification-Driven Development (FSDD). Formal specification is needed at the beginning of the development process to prevent ambiguity and to improve the quality through corrections of errors found in the late phases of a traditional design process, Software Development Life Cycle (SDLC). The research is conducted with capstone students using both the FSDD and the SDLC (traditional) models and a quantitative analysis is presented to evaluate the internal quality of the software. The tool used to measure the internal quality is the .NET 2013 analysis tool. Formal Specification-Driven Development (FSDD) is a …

Morphology-Property Relationship For Binary Organic Thin Films, Alyssa Lynn Griffin

Master's Theses

Organic thin films can be readily mass-produced through solution-based fabrication methods including ink-printing and solution-casting because their light weight, flexibility, and inexpensive sources. Their applications range from organic field-effect transistors (OFET), organic solar cells (OSC), to organic light emitting diodes (OLEDs). Compared with pure component films, binary organic thin films (BOTF) allows for novel characteristics and specialized features to handle more demanding tasks. Due to the complex intermolecular interactions in BOTF, various microscopic phases with different morphological and electronic properties may be formed and this information is difficult to extract through conventional bulk measurements.

Organic thin films can be readily …

Impact Of Calendering And Silver Addition To Carbon Nanotube-Based Electrodes Used In Printed Multi-Layer Capacitors, Ramea Awni Al-Mubarak

Masters Theses

As the demand for global energy increases, the need for development of alternative clean and sustainable energy technology increases. Creating advanced energy devices with a large storage capacity plays a significant role in this development. This research focused on investigating the performance of capacitor devices used as energy storage cells by optimizing and determining the impact of silver percentage and structure (nano-wires or silver flake) added to CNT ink on the conductivity of printed layers, and studying the influence of calendering the multi-layer capacitor electrodes. Multi-layer capacitors were fabricated by screen printing three alternative layers of conductive and dielectric inks …

Development And Verification Of A Method To Determine The Long Term Load Carrying Performance Of A Double Sided Pressure Sensitive Adhesive Tape, Rahal Rasheed

Masters Theses

Acrylic foam pressure sensitive adhesive (PSA) tapes are used in various applications as an alternative of mechanical fasteners, especially in areas like structural bonding which requires demanding bond strength and durability.

This research focuses on comparing design values of acrylic foam PSA using static shear test method and dynamic shear test method in accordance of J0MP0164 standard specification. Static shear test has lots of disadvantages; but on the other hand it is the test that mimics the real life usage of a tape in a real life application. Dynamic shear test is a faster way of testing and gives a …

Optimization Of Support Structures For Selective Laser Melting., Kai Zeng

Electronic Theses and Dissertations

Additive Manufacturing (AM) users rely on experiments and experience to predict the performance of AM processes. This trial and error approach for qualifying AM parts takes significant time and money. Simulation tools are an urgent need for today’s AM industry. One area of need is the automatic generation of optimized support structures based upon the scan patterns used to produce those structures. This research seeks to develop support structure generation tools based on real scan pattern and thermo-mechanical simulation tools for Selective Laser Melting (SLM) developed at the University of Louisville and being commercialized by 3DSIM, LLC. In order to …

Dna Based Electrolyte/Separator For Lithium Battery Application, Jitendra Kumar, Fahima Ouchen-Bouchendouka, Devin A. Smarra, Guru Subramanyam, James Grote

Electrical and Computer Engineering Faculty Publications

In this study, we demonstrated the use of DNA-CTMA (DC) in combination with PolyVinylidene Fluoride (PVDF) as a host matrix or separator for Lithium based electrolyte to form solid polymer/gel like electrolyte for potential application in Li-ion batteries.

The addition of DC provided a better thermal stability of the composite electrolyte as shown by the thermos-gravimetric analysis (TGA). The AC conductivity measurements suggest that the addition of DC to the gel electrolyte had no effect on the overall ionic conductivity of the composite. The obtained films are flexible with high mechanical stretch-ability as compared to the gel type electrolytes only.

Breast Cancer/Stromal Cells Coculture On Polyelectrolyte Films Emulates Tumor Stages And Mirna Profiles Of Clinical Samples, Amita Daverey, Karleen M. Brown, Srivatsan Kidambi

Department of Chemical and Biomolecular Engineering: Faculty Publications

In this study, we demonstrate a method for controlling breast cancer cells adhesion on polyelectrolyte multilayer (PEM) films without the aid of adhesive proteins/ ligands to study the role of tumor and stromal cell interaction on cancer biology. Numerous studies have explored engineering coculture of tumor and stromal cells predominantly using transwell coculture of stromal cells cultured onto coverslips that were subsequently added to tumor cell cultures. However, these systems imposed an artificial boundary that precluded cell−cell interactions. To our knowledge, this is the first demonstration of patterned coculture of tumor cells and stromal cells that captures the temporal changes …

Quantification Of Variable Rate Irrigation Benefits And Spatial Variability In Root Zone Water Holding Capacity, Tsz Him Lo

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

Variable rate irrigation (VRI) investment decisions require field-specific knowledge of benefits. The objective of this research was to help producers and consultants consider and quantify potential benefits of VRI. First, a conceptual model was developed for evaluating the public and/or private gain from adopting VRI where irrigation water supply is non-restrictive. Potential benefits were classified into three categories and were attributed to ten reasons. In the Central Plains at current prices, a small improvement in corn (maize) yield would make a large contribution to VRI profitability. Second, the potential irrigation withdrawal reduction from adapting VRI to spatial heterogeneity of root …

Comparison Of Two Models For Temperature Observation Of Miniature Pem Fuel Cells Under Dry Conditions, Denise A. Mckahn, Xinyi Liu

Engineering: Faculty Publications

Water and thermal management have been identified as technical hurdles to the successful implementation of low-temperature polymer electrolyte membrane (PEM) fuel cell (PEMFC) power systems. In low-power applications, miniature PEMFCs show significant promise as a competitor to lithium-ion batteries. Significant design work is underway to improve the specific power and energy densities of these fuel cells. However, little attention has been given to characterizing transient response in these miniature applications to enable gains in system design, optimization, and control. This work develops, calibrates, and experimentally validates two different dynamic control-oriented models for open-loop temperature state observation in miniature PEMFCs. Of …

On The Selection Of A Good Shape Parameter For Rbf Approximation And Its Application For Solving Pdes, Lei-Hsin Kuo

Dissertations

Meshless methods utilizing Radial Basis Functions~(RBFs) are a numerical method that require no mesh connections within the computational domain. They are useful for solving numerous real-world engineering problems. Over the past decades, after the 1970s, several RBFs have been developed and successfully applied to recover unknown functions and to solve Partial Differential Equations (PDEs).
However, some RBFs, such as Multiquadratic (MQ), Gaussian (GA), and Matern functions, contain a free variable, the shape parameter, c. Because c exerts a strong influence on the accuracy of numerical solutions, much effort has been devoted to developing methods for determining shape parameters which provide …

Cost Effective Quality Assurance Practices In Highway Construction, James M. Newland

Electronic Theses and Dissertations

The estimated value of the U.S. transportation infrastructure is over $7.0 trillion. The challenge is preserving the quality of the investment. State and federal departments of transportation have methods and procedures for best quality, but vary significantly. With the variations comes opportunity to assess the cost-effectiveness of different strategies and make recommendation on practices that are most successful.

A survey was created and sent to all 50 states and the District of Columbia. The survey was aimed to capture information on construction finished product testing methods, optimized/reduced sampling techniques, innovative QA practices that measure multiple performance criteria and QA processes …

Evaluating The Security Of Smart Home Hubs, Steven A. Christiaens

Theses and Dissertations

The goal of this research is to improve the security of smart home hubs by developing a standard against which hubs can be evaluated. This was done by first reviewing existing standards, guides, and collections of best practices. I determined that adapting or extending an existing standard was the best way to proceed. Potential candidates were selected, and after thorough comparison, I chose to extend the OWASP Application Security Verification Standard (ASVS). Extensions were composed of additional security requirements to address smart home hub functionality not covered by the existing requirements of the ASVS. These additional requirements were developed based …

Neutral Parametric Canonical Form For 2d And 3d Wireframe Cad Geometry, Robert Steven Freeman

Theses and Dissertations

The challenge of interoperability is to retain model integrity when different software applications exchange and interpret model data. Transferring CAD data between heterogeneous CAD systems is a challenge because of differences in feature representation. A study by the National Institute for Standards and Technology (NIST) performed in 1999 made a conservative estimate that inadequate interoperability in the automotive industry costs them $1 billion per year. One critical part of eliminating the high costs due to poor interoperability is a neutral format between heterogeneous CAD systems. An effective neutral CAD format should include a current-state data store, be associative, include the …

Improving The Suction Performance And Stability Of An Inducer With An Integrated Inlet Cover Bleed System Known As A Stability Control Device, Ryan K. Lundgreen

Theses and Dissertations

The performance of an inducer with the integration of an inlet cover bleed system known as a stability control device (SCD) is investigated using computational fluid dynamics. Inducers are the first stage of high suction performance pumps and are designed to operate under cavitating conditions. Improvements in design have allowed inducers to operate stably with low inlet head conditions, however, cavitation instabilities ultimately lead to pump failure. It has been shown that inducers that employ an SCD fully suppress cavitation instabilities.The performance of an inducer is explored at both on- and off-design flow coefficients, where the flow coefficient is a …

Empirical Study Utilizing Qfd To Develop An International Marketing Strategy, Cassandra C. Elrod, Sarah M. Stanley, Elizabeth A. Cudney, Caroline Fisher

Business and Information Technology Faculty Research & Creative Works

Customer expectations can be extremely nebulous. This research identifies the demographic segmentations and their respective expectations for the spa market. Interviews were conducted and a subsequent questionnaire was employed to gather the voice of the customer and assess the expectations of spa clientele. All of the data was collected from luxury spas in Hawaii, and consisted of respondents from all over the world. Results of the survey suggest that while men want more tangible benefits of a spa, women prefer the experiential qualities of peace and rejuvenation. Additionally, those of lower to middle income focus on the atmosphere more than …