Engineering Commons^™

Effect Of Cement Content On Concrete Performance, Caleb Joshua Lebow

Graduate Theses and Dissertations

Of all the traditional concrete materials, portland cement has the greatest impact on mixture cost and the environment. Cement is in many ways the glue holding concrete together (Weiss, 1999), and as such, it plays a major role in fresh and hardened concrete properties. Without the proper range of cement in the mixture, low strength development or excessive shrinkage may occur leading to premature deterioration. The Arkansas Department of Transportation (ARDOT) recognizes two types of concrete for use in bridge construction, Class S and Class S(AE). This paper focuses on the findings from testing of Class S(AE) concrete, short for …

Developing Computer Codes For Analyzing Bridge Response Due To Wim Data Truck Loading, Kenneth Patrick Pasley

Graduate Theses and Dissertations

Despite actual truck demographics evolving over the past 30 years, the Arkansas legal loads for bridge posting have not been updated. Custom computer codes were developed.to facilitate comparison between the current Arkansas legal loads for bridge posting and the actual Arkansas truck traffic to ensure that actual reactions are enveloped by the state'. The program, WIMFluence, calculates shear and moment influence lines for a bridge and the resulting shear and moment reactions based on weigh-in-motion data. With supporting scripts, the reactions due to actual Arkansas truck traffic were compared to those due to the current Arkansas legal loads for bridge …

A Perceptual Comparison Of “Black Box” Modeling Algorithms For Nonlinear Audio Systems, Paul G. Mayo

Audio Engineering Theses

Nonlinear systems identification is a widespread topic of interest, particularly within the audio industry, as these techniques are employed to synthesize black box models of nonlinear audio effects. Given the myriad approaches to black box modeling, questions arise as to whether an “optimal” approach exists, or one that achieves valid subjective results as a model with minimal computational expense. This thesis uses ABX listening tests to compare black box models of three hardware audio effects using two popular nonlinear implementations, along with two proposed modified implementations. Models were constructed in the Hammerstein form using sine sweeps and a novel measurement …

Opto-Thermal Characterization Of Plasmon And Coupled Lattice Resonances In 2-D Metamaterial Arrays, Vinith Bejugam

Graduate Theses and Dissertations

Growing population and climate change inevitably requires longstanding dependency on sustainable sources of energy that are conducive to ecological balance, economies of scale and reduction of waste heat. Plasmonic-photonic systems are at the forefront of offering a promising path towards efficient light harvesting for enhanced optoelectronics, sensing, and chemical separations. Two-dimensional (2-D) metamaterial arrays of plasmonic nanoparticles arranged in polymer lattices developed herein support thermoplasmonic heating at off-resonances (near infrared, NIR) in addition to regular plasmonic resonances (visible), which extends their applicability compared to random dispersions. Especially, thermal responses of 2-D arrays at coupled lattice resonance (CLR) wavelengths were comparable …

Development And Characterization Of Aqueous-Based Recombinant Spider Silk Protein Biomaterials With Investigations Into Potential Applications, Thomas I. Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider silks are incredible natural materials that possess desirable combinations of strength, elasticity, weight, and robustness. Other properties such as biocompatibility and biodegradability further increase the worth of these materials. The possibility of farming spiders is impractical due to spiders’ natural behaviors. Modern biotechnologies have allowed for recombinant spider silk proteins (rSSps) to be produced without the use of spiders. However, the features responsible for spider silks impressive properties can cause difficulties with producing silk materials. A recently developed water-based and biomimetic solvation method has provided a solution to such difficulties and has also led to novel silk biomaterials. Most …

High Performance Thermal Insulation: Silica Aerogels In Construction Technology, Matthew Giarrusso

Honors Theses

The United States is a world leader in the production and expenditure of energy, accounting for 18% of the total global energy consumption in 2016, 40% of which was used for the heating, cooling, and lighting of commercial and residential buildings. Currently, traditional air-based insulation products are being used in thicker and more numerous layers in an attempt to keep up with contemporary codes and standards. One promising alternative to traditional insulation is silica aerogel. With a remarkably low density and thermal conductivity, silica aerogel could save energy, space, and weight in new and retrofit structures. Silica aerogels are currently …

Sustainability Children's Book, Linden Cheek

Biological and Agricultural Engineering Undergraduate Honors Theses

As human driven climate change continues to alter our planet, persuading the general public to adopt sustainable living practices has become increasingly important. Storytelling has long been a part of human culture, and recent studies have emphasized the power of storytelling to influence the audience as a means of changing behavior. This project attempted to teach sustainable principles to primary school children through the creation of a scientific children’s book. The book communicated the maxim of “reduce, reuse, recycle” by tracing a fictitious story of a town where children frequently buy new toys and throw the old toys away. The …

Ut Football Automated Practice Target, Mary Elizabeth Iannuzzi, Lee Fullam, Lindsay Little, Julia Meyer

Chancellor’s Honors Program Projects

No abstract provided.

Corner Sealants For Tactical Shelters, Janine Carlita Nowak

Honors Theses

The demand for a lightweight, easy-assembly tactical shelter is high for those faced with unexpected disasters and global conflicts. This project focuses on designing and prototyping the corner sealant for such a shelter. Two materials were chosen and tested: an in-house thermoplastic polyurethane (TPU) and Texin 950. Thermogravimetric Analysis (TGA) was performed on both of these materials. The in-house TPU showed initial degradation at 282.50 °C and sample degradation at 457.45 °C. Similarly, Texin 950 showed initial degradation at 293.68 °C and sample degradation at 453.26 °C. Differential Scanning Calorimetry (DSC) was then run. The crystallization temperature (Tc) was observed …

The Future Of Construction As It Applies To The Colonization Of The Moon And Mars, Julian Prestia

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goals of this research are:

1. To compile a comprehensive list of all the viable known solutions (and early stage potential solutions) to the issues related to constructing permanent, sustainable, and safe structures for human colonies on our moon and Mars,

2. Determine the most effective potential solutions, and

3. Further develop these ideas as to assist in further space endeavors.

This proposed paper will assist space experts in determining the best next steps in the development of deep-space travel and colonization technologies. Preliminary research has identified several key problems associated with establishing space colonies. They are as follows: …

A Comparison Of Traditional Education And Project-Based Education In Construction Management, Trey Miller

Honors College Theses

Construction is a rapidly moving and constantly changing industry. The skills needed to manage the complex task of running a job site safely, on schedule, and within budget, are unique to the field. Construction Management as an academic field is relatively new discipline. Therefore the field is still rapidly evolving. In many cases, classes are taught by engineering professors, which leads to an engineering-focused education as opposed to a Project Management focused education. Therefore Construction Management students are not receiving the “hands-on” experience early enough in their studies. By structuring classes around an applied project, students will attain a more …

Analysis Of Cross-Cultural Training Provided To United States Air Force Civil Engineer Officers, And How Engineering Efforts Are Affected On Overseas Air Force Installations: A Delphi Study, Bianca E. Boney

Theses and Dissertations

U.S. military personnel perform a wide array of roles and missions at locations all over the world. As such, this research investigates and describes the current process of cultural training, its adequacy, and examines how cultural differences and collaboration efforts may impede or enhance project management and engineering efforts. This qualitative analysis is conducted through a Delphi study of U.S. Air Force officers consisting of 15 subject matter experts (SMEs) with experiences from 13 different countries. All reported to have daily to weekly interactions with locals and foreign partners due to job requirements; however, no set standard of cultural training …

Rc Baja Car Suspension, Tyler Martin

All Undergraduate Projects

This year the Mechanical Engineering Technology Department at CWU is holding an R/C Baja car competition using the same rules as the ASME competition. The designed car must compete in three separate events: the slalom course, drag race, and obstacle course. By not only completing, but also being competitive in each of the events, the car will be deemed a success. Suspension and steering are two essential components of any R/C car, and was the main focus for this report. The suspension must be able to support the car in the event of impacts. In addition, the steering must be …

Senior Project Hauff Tree Pruner, Brian Woolery

All Undergraduate Projects

Neil Hauff, a business owner and entrepreneur from the Yakima valley challenged a team of engineering students from Central Washington University to design a motorized apple tree pruner. This report will discuss the engineering and construction that went into creating the housing of the tree pruner. The housing component needed to be able to protect the moving parts of the pruner, while withstanding the rotational torque produced by the Makita power drill used to drive the pruner. The biggest constraint in designing the housing was to keep the weight of the housing component under 1.5 lbs, while still keeping the …

H.F. Hauff Pruner Cutting Blades, Wyley Stewart

All Undergraduate Projects

Apple orchards are a critical component of agriculture in the United States, and keeping the apple trees in the best shape for optimum growth and production is hard work. Neil Hauff, an agriculture industry expert, challenged students at CWU to engineer a power assisted tree pruner. Across the country, apple orchards need pruned every season. The pruning of the trees is strenuous manual labor that requires many man hours. The proposed solution is to create a power assisted tree pruner that would minimize the amount of work needed to trim each tree branch. This project has been separated into three …

Optimization Of Heat Sinks In A Range Of Configurations., Archibald Allswell Amoako

Electronic Theses and Dissertations

In this study, different heatsink geometries used for electronic cooling are studied and compared to each other to determine the most efficient. The goal is to optimize heat transfer of the heat sinks studied in a range of configuration based on fin geometry. Heat sinks are thermal conductive material devices designed to absorb and disperse heat from high-temperature objects (e.g. Computer CPU). Common materials used in the manufacturing of heat sinks are aluminum and copper due to their relatively high thermal conductivity and lightweight [1]. Aluminum is used as the material for the heatsinks studied in this research project. To …

Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat

ETD Archive

Recent powered lower-limb prosthetic and orthotic (P/O) devices aim to restore legged mobility for persons with an amputation or spinal cord injury. Though various control strategies have been proposed for these devices, specifically finite-state impedance controllers, natural gait mechanics are not usually achieved. The goal of this project was to invent a biologically-inspired controller for powered P/O devices. We hypothesize that a more muscle-like actuation system, including spinal reflexes and vestibular feedback, can achieve able-bodied walking and also respond to outside perturbations. The outputs of the Virtual Muscle Reflex (VMR) controller are joint torque commands, sent to the electric motors …

Non-Intrusive Optical Measurement Of Electron Temperature In Near Field Plume Of Hall Thruster, Peter J. Urban

ETD Archive

Currently there is a large interest in the use of more efficient means of propulsion in long term missions due to the costs and difficulties associated with placing and maintaining the needed fuel for conventional chemical systems in orbit. Mass reduction of upper stages will return large returns due to the great reduction in required lower stage fuel. Due to these factors, alternatives are undergoing active research, though this paper is concerned with the area of electrical propulsion. Electric propulsion is broadly defined as propulsion where the energization of the exhaust occurs via application of electromagnetic fields as opposed to …

A Transformative Process Control Solution, Simone Castanho Nobrega De Almedia Soares

ETD Archive

Knowing that a technology invented almost hundred years ago (PID controller) is still dominating industrial process control, a historical review was done to understand how the control field evolved. Model dependency and high level of mathematics appear as the main reasons that prevent other technologies from penetrating the engineering practice. A relatively novel methodology introduced by J. Han in 1998 called Active Disturbance Rejection Control (ADRC) came with characteristics that matches process control needs and restrictions on model dependency. This study will present a transformative solution for process control based on that. The control algorithm is designed and discretized for …

Real-Time Assessment And Visual Feedback For Patient Rehabilitation Using Inertial Sensors, Deepa Adinarayanan

ETD Archive

Rehabilitation exercises needs have been continuously increasing and have been projected to increase in future as well based on its demand for aging population, recovering from surgery, injury and illness and the living and working lifestyle of the people. This research aims to tackle one of the most critical issues faced by the exercise administers-Adherence or Non-Adherence to Home Exercise problems especially has been a significant issue resulting in extensive research on the psychological analysis of people involved. In this research, a solution is provided to increase the adherence of such programs through an automated real-time assessment with constant visual …

Influence Of Natural Convection During Dendritic Array Growth Of Metal Alloys (Gradient Freeze Directional Solidification), Suyog N. Mahajan

ETD Archive

Purpose of this study was to examine the microstructural evolution of primary dendrites during Gradient Freeze Directional Solidification process in cylindrical Pb-5.8% Sb alloy samples to generate the ground- based research data to support a future microgravity experiment on the Space Station in a convection free environment. Pb-5.8Sb was selected for this study because of its ease of processing and availability of physical property data which will be required for predicting the dendrite morphology parameters, such as, primary dendrite spacing and dendrite trunk diameter. This alloy is also susceptible to thermosolutal convection caused by density inversion of the met in …

Quality Improvement Of Recycled Concrete Aggregate Using Polymers, Ahmed Ali Abdrabbou

Master's Theses and Doctoral Dissertations

Crushed concrete is one of the main resources for sustainable material. As this material should not be wasted, this research aims to assess the reuse of crushed concrete material as a resource of sustainable construction material. In this thesis, two types of polymer were mixed with crushed concrete to improve its fragmentation resistance, water absorption, and permeability. Water base polymer is an eco-friendly and cost-effective material, which has been used frequently to improve the quality of crushed concrete. This thesis contributes to the improvement of crushed concrete performance by improving the aggregate properties when it is mixed with a polymer, …

Manufacturing A Composite Wheel Prototype Using 3d Printed Molds, Steven Thuening

All Graduate Theses, Dissertations, and Other Capstone Projects

Throughout the evolution of high performance racing, a large emphasis has been on reducing the weight of the vehicle in order to improve its performance. Over the years, new designs and materials have been introduced reducing weight in a variety of different locations. Comparing weight reduced in different areas has shown that some areas are more valuable to reduce than others are. Perhaps one of the most beneficial locations are the wheels. This is because the mass of the wheel is considered unsprung and rotational. Because of this, large improvements towards the reduction of wheel mass have been developed in …

Cyber-Physical Embedded Systems With Transient Supervisory Command And Control: A Framework For Validating Safety Response In Automated Collision Avoidance Systems, Daniel K. Trembley

Graduate Dissertations and Theses

The ability to design and engineer complex and dynamical Cyber-Physical Systems (CPS) requires a systematic view that requires a definition of level of automation intent for the system. Since CPS covers a diverse range of systemized implementations of smart and intelligent technologies networked within a system of systems (SoS), the terms “smart” and “intelligent” is frequently used in describing systems that perform complex operations with a reduced need of a human-agent. The difference between this research and most papers in publication on CPS is that most other research focuses on the performance of the CPS rather than on the correctness …

Trochoidal Milling Of Alsicp With Cvd Diamond Coated End Mills, Tony Nguyen

University of the Pacific Theses and Dissertations

Metal matrix composites have seen a rise in demand within the last decade. Aluminum alloy reinforced with silicon carbide particles is a type of particle metal matrix composite that has seen applications in the aerospace, ground transportation, and electronics industry. However, the abrasive SiC particles have made this material difficult to machine through conventional machining strategies. This research will focus on using computer aided manufacturing with trochoidal tool paths to maximize machining productivity and extend the tool life of CVD diamond coated end mills. The focus of this research will be on AlSiCp with a high volume fraction of reinforcement …

Wideband Doa And Parameter Estimation Of Chirp Sources Using Dcft And Compressive Sensing, Luay A. Al Irkhis

Browse all Theses and Dissertations

Direction of Arrival (DoA) estimation of chirp sources has many applications in radar, sonar and medical imaging. This work considers DoA and parameter estimation of wide- band chirp sources by the use of Discrete Chirp Fourier Transform (DCFT), its Compres- sive Sensing formulation (CS-DCFT) and Distributed CS. DCFT is similar to traditional Discrete Fourier Transform (DFT) but with chirp ba- sis and two-dimensional search over chirp rate and chirp frequency. For chirp parame- ters estimation, the proposed Compressive Sensing (CS) formulation uses the parametric DCFT basis to achieve superior estimator performance in polynomial time using Orthog- onal Matching Pursuit (OMP) …

Wetting Properties Of Structured Interfaces Composed Of Surface-Attached Spherical Nanoparticles, Bishal Bhattarai

Browse all Theses and Dissertations

In this thesis, the effects of the external pressure and surface energy on stability and wetting transition at nanotextured interfaces are studied using molecular dynamics and continuum simulations. The surface roughness of the composite interface is modeled via an array of spherical nanoparticles with controlled wettability. It was found that in the absence of external pressure, the liquid interface is flat and its location relative to the solid substrate is determined by the radius of the particle and the local contact angle. With increasing pressure on the liquid film, its interface becomes more curved and the three-phase contact line is …

Microstructural Characterization Of LensTm Ti-6al-4v: Investigating The Effects Of Process Variables Across Multiple Deposit Geometries, Laura Christine Davidson

Browse all Theses and Dissertations

Laser based additive manufacturing of Ti-6Al-4V components is under consideration for aerospace applications. The mechanical properties of the finished components depend on their microstructure. Process mapping compares process variables such as heat source power, heat source travel speed, material feed rate, part preheat temperature and feature geometry to process outcomes such as microstructure, melt pool geometry and residual stresses. In this work, the microstructure of two-dimensional pads, multilayer pads, thin walls, and structural components at the steady state location was observed. A method for measuring β grain widths that allows for the calculation of standard deviations, confidence intervals, and variances …

Hardware Security And Vlsi Design Optimization, Hao Xue

Browse all Theses and Dissertations

Microelectronic circuit is ubiquitous component of modern electrical devices. The increasing complexity and professionality of phases in microelectronic supply chain bring more global cooperation to integrated circuit (IC) production. Therefore, providing a secure environment for microelectronic circuit design does not ensure the integrity of the hardware since any participator of IC fabrication has the opportunity to implant a malicious alteration in original IC design. Especially overseas chip-fabrication is a vital potential threat for national defense products. In theory, anyone who has access to fabrication process can tamper with the original design, with the potential to change function, modify parametric properties …

Resonant Gate-Drive Circuits For High-Frequency Power Converters, Hur Jedi

Browse all Theses and Dissertations

The development trend of power converters motivates the pursuit with high density, high efficiency, and low cost. Increasing the frequency can improve the power density and lead to small passive elements and a fast dynamic response. Each one of these power converters must be driven by a gate-drive circuit to operate efficiently. Conventional gate-drivers are used up to frequencies of about 5 MHz and suffer from switching losses. Therefore, the development of switch-mode power supplies (SMPS) operating at high frequencies requires high-speed gate drivers. The presented research in this dissertation focuses on analysis, design, and development of new types of …