Engineering Commons^™

Existence Of Ballistic Capture Transfer Trajectories From Trans-Lunar Injection To Lunar Polar Orbit For All Lunar Phases At Time Of Departure, Anthony Lawrence Genova

Theses and Dissertations

This dissertation reveals several families of trajectories that can reduce the change in velocity(ΔV) required to transfer from trans-lunar injection (TLI) to a lunar polar circular orbit with 100 km altitude by up to 26.5% compared to conventional transfers. The primary hypothesis states that such trajectories, termed lunar polar ballistic capture (LPBC) transfers, exist for all lunar phases at the time of lunar departure (i.e., initial lunar flyby).The existence of LPBC transfers for all lunar phases can enable missions with ride-share restrictions (CubeSat), limited propellant capability (small spacecraft), and/or payloads that are not time sensitive (cargo).Evidence to support the primary …

Correlation Between Air Quality Index And Traffic Volume Using Internet Of Things (Iot), Omar Sayah Alruwaili

Theses and Dissertations

In highly populated world areas, such as metropolises, hazardous air pollution has been linked to the presence of damaging climate and health issues, which are becoming increasingly common. Indeed, a major problem facing urban areas today is air pollution. Gas emissions from vehicles can be seen as the most important source of this kind of pollution. Pollutant gases emitted as parts of car exhaust consist of chemicals such as carbon monoxide (CO), nitrogen dioxide (NO2), and sulphur dioxide (SO2), and ozone (O3), as well as particulate matter (PM). In some places in the world, non-governmental and foreign corporations have also …

Development Of A Design Method For Bonded Concrete Pavement Overlays, Ahmed Alsabbagh

Theses and Dissertations

Several asphalt pavements prematurely reached the end of their design life due to wheel loading has dramatically increased on highways. Therefore, transportation and highways agencies often endeavor to provide high-performance pavement to ensure the longest life with low maintenance required. Although asphalt pavement overlay (APO) can provide a quick and low-cost option for pavements rehabilitation, it frequently exhibits excessive rutting especially at highway pavement subjected to stop-and-go traffic conditions. Hence, concrete pavement overlays (CPO) is one of the alternative options for rehabilitating deteriorated pavements. The ultra-thin white topping (UTW) is one type of concrete overlay types and is considered a …

Optimizing Energy Power Consumption Of Freight Railroad Bearings Using Experimental Data, Carlos Eliasar Lopez Iii

Theses and Dissertations

Throughout the railway industry, trains use systems that record total energy efficiency of a train but not energy efficiency or consumption by components. Monitoring freight bearing power consumption can support the railroad industry efforts to maintain the railroad economic competitiveness and minimize the environmental impact.

For more than a decade now, the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV) has been collecting power consumption data for railroad bearings under various loads, speeds, ambient temperatures, bearing condition, and bearing classes. Specifically, data such as temperatures, voltages, speed, and load were collected to …

Water-Soluble Polymers With Ceramic/Metal Nanoparticles For Use As Anode Materials In Lithium-Ion And Sodium-Ion Batteries, Roberto Orrostieta Chavez

Theses and Dissertations

Aqueous solutions of poly(vinylpyrrolidone) (PVP) with 20, 25, and 28 wt.% concentrations were successfully spun into fibers by centrifugal spinning. The pristine PVP fibers were annealed and carbonized to produce flexible carbon fibers for use as binder-free anodes in lithium-ion and sodium-ion batteries. These flexible carbon fibers were prepared by developing a novel three-step heat treatment to reduce the residual stresses in the pristine PVP precursor fibers and to prevent fiber degradation during carbonization. The average diameters of the pristine, annealed, and carbonized fibers were obtained using scanning electron microscopy (SEM), which showed that the average diameter of the carbon …

A Study On The Triaxial Shear Behavior Of Geosynthetic Reinforced Soil By Discrete Element Method, Md Wasif Zaman

Theses and Dissertations

A 3D DEM model using Particle Flow Code (PFC3D) software was developed utilizing a bonded-ball flexible membrane approach to study cohesionless soil as a discontinuous discrete material. The 3D model was calibrated and verified with experimental data, and a sensitivity analysis was carried out for the microparameters. Triaxial tests were simulated to observe the stress-strain curves and volumetric changes, as well as the strength parameters of soils consisting of spherical particles with different gradations but the same porosity. One important finding is that the relationships between particle size and deviatoric stress, internal friction angle, and dilatancy angle were found to …

Microsoft’S Surface Pro 4 Performance Under Denial Of Service Attack, Adrian Guerrero

Theses and Dissertations

Microsoft Surface Pro 4 (SP4) is a new device in the line of hybrid computers today. It aims to work as both as table and laptop computer. There are multiple versions of SP4 that include devices equipped with i3, i5 and i7 core processors.

This makes SP4 a great addition for hospital, clinics or schools for its portability and features. As these locations can be prone to cyber-attacks, we plan to test this computer’s reliability and performance under cybersecurity attacks. The device tested is built with Intel Core i7-6650U 2.21 GHz processor with automatic overclocking capabilities up to 3.4 GHz, …

The Integration Of Iterative Convergent Photogrammetric Models And Uav View And Path Planning Algorithms Into The Aerial Inspection Practices In Areas With Aerial Hazards, Michael James Freeman

Theses and Dissertations

Small unmanned aerial vehicles (sUAV) can produce valuable data for inspections, topography, mapping, and 3D modeling of structures. Used by multiple industries, sUAV can help inspect and study geographic and structural sites. Typically, the sUAV and camera specifications require optimal conditions with known geography and fly pre-determined flight paths. However, if the environment changes, new undetectable aerial hazards may intersect new flight paths. This makes it difficult to construct autonomous flight path missions that are safe in post-hazard areas where the flight paths are based on previously built models or previously known terrain details. The goal of this research is …

Development Of A Self-Powered Weigh-In-Motion System, Athanassios Papagiannakis, Sarah Ahmed, Samer Dessouky, Reza Khalili, Gopal Vishwakarma

Publications

This report describes the development of a novel weigh-in-motion (WIM) system that utilizes piezoelectric elements for sensing load and powering an ultra-low power microcontroller unit (MCU) that serves as its data acquisition system. A system of 4 piezoelectric (PZT) stacks serves as the energy harvester, while load sensing is done via a set of 4 PZT elements connected in parallel. Two alternative MCUs were considered, with various data handling capabilities and power consumption requirements. These MCUs have very short “wake-up” times allowing vehicle sensing without the need for inductive loops commonly used in conventional WIM systems. Special electric circuits were …

Identifying Depressive Symptoms From Tweets: Figurative Language Enabled Multitask Learning Framework, Shweta Yadav, Jainish Chauhan, Joy Prakash Sain, Krishnaprasad Thirunarayan, Amit P. Sheth, Jeremiah Schumm

Publications

Existing studies on using social media for deriving mental health status of users focus on the depression detection task. However, for case management and referral to psychiatrists, healthcare workers require practical and scalable depressive disorder screening and triage system. This study aims to design and evaluate a decision support system (DSS) to reliably determine the depressive triage level by capturing fine-grained depressive symptoms expressed in user tweets through the emulation of Patient Health Questionnaire-9 (PHQ-9) that is routinely used in clinical practice. The reliable detection of depressive symptoms from tweets is challenging because the 280-character limit on tweets incentivizes the …

Virtual Head Waves In Ocean Ambient Noise: Theory And Modeling, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan

Electrical and Computer Engineering Faculty Publications and Presentations

The Green's function retrieval in media with horizontal boundaries usually only considers the extraction of direct and reflected waves but ignores the virtual head waves, which have been observed experimentally from ocean ambient noise and used to invert for geometric and environmental parameters. This paper derives the extraction of virtual head waves from ocean ambient noise using a vertically spaced sensor pair in a Pekeris waveguide. Ocean ambient noise in the water column is a superposition of direct, reflected, and head waves. The virtual head waves are produced by the cross-correlations between head waves and either reflected waves or other …

The Optimization Of Efficiency And Infrastructure For Modern Potable Water Treatment Plants, Brent A. Dekock

Theses and Dissertations

The USDOE Industrial Assessment Centers (IACs) is a program that is designed to help small and medium-sized manufacturing facilities reduce their overall costs and improve energy efficiency. This includes improving potable water treatment plants which supply water throughout the country. This thesis covers the process of how IAC branches and water treatment facilities generally operate, as well as several assessment recommendations that have been developed by a branch of the IAC for several water treatment plants based in the Rio Grande Valley of Texas. The steps of the assessment and water treatment process are described, and several cost saving measures …

Ac Electrokinetic Effect Of V-Electrode Pattern On Microfluids, Mohammad Salman Parvez

Theses and Dissertations

Electrokinetics has been used for guiding, pumping, and manipulating microfluidic particles for many years in the field of Biomedical, Microbiology, Chemistry, Medicine, and other fields of research, which makes it a ubiquitous tool for the multidisciplinary research on microfluidics. Between these two Alternating Current (AC) Electrokinetics have been proven to be more feasible for the researcher than the other one. In this research, we have investigated AC Electrokinetics and s effect on a new electrode configuration called V-electrode pattern. The V-electrode has been inspired and modified from the previous research work on the Orthogonal Electrode Pattern. In this research, this …

Comparison Of Pre-Intervention Idi Results From Stem And Non-Stem Undergraduate Students, Anne M. Lucietto, Liza Russell

Journal of Global Education and Research

The emphasis on intercultural competence is more prevalent in STEM (Science, Technology, Engineering and Mathematics) majors as the world shifts towards a more globalized economy. When entering higher education, students have differing levels of cultural interaction due to varying peer interaction, family experiences, international travel, and social media experiences. The Intercultural Development Inventory (IDI) has been used to develop an understanding of how students view others and the level of skills they have to interact and adapt to other cultures. Using published data focused on pre-intervention assessment, researchers compared it to data obtained from STEM students preparing for an international …

Network-Level Mechanisms Underlying Effects Of Transcranial Direct Current Stimulation (Tdcs) On Visuomotor Learning, Pejman Sehatpour, Clément Dondé, Matthew J. Hoptman, Johanna Kreither, Devin Adair, Elisa Dias, Blair Vail, Stephanie Rohrig, Gail Silipo, Javier Lopez-Calderon, Antigona Martinez, Daniel C. Javitt

Publications and Research

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation approach in which low level currents are administered over the scalp to influence underlying brain function. Prevailing theories of tDCS focus on modulation of excitation-inhibition balance at the local stimulation location. However, network level effects are reported as well, and appear to depend upon differential underlying mechanisms. Here, we evaluated potential network-level effects of tDCS during the Serial Reaction Time Task (SRTT) using convergent EEG- and fMRI-based connectivity approaches. Motor learning manifested as a significant (p <.0001) shift from slow to fast responses and corresponded to a significant increase in beta-coherence (p <.0001) and fMRI connectivity (p <.01) particularly within the visual-motor pathway. Differential patterns of tDCS effect were observed within different parametric task versions, consistent with network models. Overall, these findings demonstrate objective physiological effects of tDCS at the network level that result in effective behavioral modulation when tDCS parameters are matched to network-level requirements of the underlying task.

Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb

Theses and Dissertations

The objective of this thesis is to create a method of simulating the performance of new materials for use in air cushion vehicle skirts. These systems currently exhibit unacceptable design lifetimes to be considered for widespread adoption, except in specific applications such a military or rapid transport, where high cost is not an obstacle. This project also focuses on using a new high strain to failure resin system that has recently been developed, in combination with high performance reinforcing fibers, to increase the lifespan of the skirt systems. Using industry-standard finite element modelling (FEM) software, a 3d model of the …

Current And Projected Water Reuse For Irrigation In Utah, R. Ryan Dupont, Joan E. Mclean, Randal S. Martin, Courtney Flint, L. Niel Allen, Jennifer L. Weidhaas

Reports

Reuse of treated wastewater for irrigation in some cases can help meet increasing agriculture and urban water demands in Utah. The last report describing existing and potential reuse efforts in Utah was in 2005 (Utah Division of Water Resources, 2005). This report provides information on existing and proposed water reuse and perceptions among water providers and users regarding the use of reclaimed wastewater. Wastewater reuse is one of many practices to conserve water and improve water quality. In a broad sense, water reuse occurs by downstream users, but in some cases, deliberate strategic reuse of water is undertaken to provide …

Decentralized Event-Triggered Control In The Presence Of Adversaries, Paul Griffioen, Raffaele Romagnoli, Bruce H. Krogh, Bruce Sinopoli

Faculty Work Comprehensive List

Decentralized control systems are widely used in a number of situations and applications. In order for these systems to function properly and achieve their desired goals, information must be propagated between agents. However, communication between agents entails connecting to a network, potentially allowing adversaries to infiltrate the system through the network and attack multiple agents. To increase resiliency against these attacks, it is desirable for agents to operate disconnected from the network as much as possible, only communicating with other agents when it is absolutely necessary to achieve their goal or to maintain the safety of the overall system. This …

Pre-Construction Documents For A Mobile Food Assembling & Distribution Station, Winnie He

Construction Management

On Christmas Eve of 2018, Jessica He Liu, a chef in Los Angeles opened her home to friends and family to volunteer and help assemble food boxes and personal hygiene products and distributed these goods out to those in need. What started off as a goal to spread kindness during the holidays, became a yearly traditional non-profit volunteering event for those families involved. In March 2020, the deadly COVID-19 pandemic took the world by surprise, causing a copious amount of social distancing guild lines to be formed and enforced. Although there was still a slight hope that the pandemic would …

Scenario-Based Development And Verification Of Domain-Specific Languages, Bharvi Chhaya

Doctoral Dissertations and Master's Theses

The use of domain-specific languages (DSLs) has increased manifold for problem solving in specific domain areas as they allow for a wider variety of expressions within their domain. Modeling using DSLs has shown high increases in productivity after accounting for the time and cost expended in developing them, making them a suitable target for improvement in order to reap higher rewards. The currently used approach for domain modeling involves the creation of an ontology which is then used to describe the domain model. This ontology encapsulates all domain knowledge and can be cumbersome to create, requiring external sources of information …

Concentration And Treatment Of Odors Generated By Landfills, Gabriel Cohen

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Landfills produce hydrogen sulfide (H₂S), an odorous compound that can be a nuisance and danger to public. Biological treatment, in particular bio-trickling filters, is a method for controlling H₂S emissions but startup costs can be costly. The goal of this study is to provide a low-cost method for improving environmental air quality in Nebraska through an odor control device. This study determined that the Loup Central Landfill located near Elba, NE would be an adequate site for the testing and implementation of the odor control device. The off-gas of the Loup Central Landfill was tested for …

Neonicotinoid Pesticide And Nitrate Removal In Floating Treatment Wetlands, Julia Lindgren

Department of Environmental Engineering: Theses and Other Student Research

Nutrient and pesticide concentrations in surface water are a growing concern in the Midwest. Floating treatment wetlands (FTWs) are often used to remove excess nutrients from surface water and should be considered for removal of emerging contaminants, such as neonicotinoids. Therefore, the objectives for this research project were: 1) Determine FTW neonicotinoid removal capacity, 2) Quantify neonicotinoid incorporation into floating macrophytes, and 3) Explore potential implications of neonicotinoids on microbial denitrification. A microcosm and mesocosm experiment was completed. The mesocosm experiment evaluated 3 treatments: 1) FTW mesocosm with neonicotinoids, 2) FTW without neonicotinoids, and 3) mesocosm with neonicotinoids and without …

Toward Understanding Underlying Mechanisms Of Drag Reduction In Turbulent Flow Control, Alex Rogge

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

The underlying mechanisms of three different flow-control strategies on drag reduction in a turbulent channel flow are investigated by direct numerical simulations. These strategies include the addition of a small concentration of long-chain polymers into a fluid, the incorporation of slip surfaces, and the application of an external body force. While it has been believed that such methods lead to a skin-friction reduction by controlling near-wall flow structures, the underlying mechanisms at play are still not as clear. In this study, a temporal analysis is employed to elucidate underlying drag-reduction mechanisms among these methods. The analysis is based on the …

High-Temperature Optoelectronic Device Characterization And Integration Towards Optical Isolation For High-Density Power Modules, Syam Madhusoodhanan

Graduate Theses and Dissertations

Power modules based on wide bandgap (WBG) materials enhance reliability and considerably reduce cooling requirements that lead to a significant reduction in total system cost and weight. Although these innovative properties lead power modules to higher power density, some concerns still need to be addressed to take full advantage of WBG-based modules. For example, the use of bulky transformers as a galvanic isolation system to float the high voltage gate driver limits further size reduction of the high-temperature power modules. Bulky transformers can be replaced by integrating high-temperature optocouplers to scale down power modules further and achieve disrupting performance in …

Fractional Order Identification Method And Control: Development Of Control For Non-Minimum Phase Fractional Order System, Majid Abdullah Alhomim

Graduate Theses and Dissertations

The increasing use of renewable energy has resulted in the need for improved a dc-dc converters. This type of electronic-based equipment is needed to interface the dc voltages normally encountered with solar arrays and battery systems to voltage levels suitable for connecting three phase inverters to distribution level networks. As grid-connected solar power levels continue to increase, there is a corresponding need for improved modeling and control of power electronic converters. In particular, higher levels of boost ratios are needed to connect low voltage circuits (less than 1000 V) to medium voltage levels in the range of 13 kV to …

Robust Control Of A Multi-Phase Interleaved Boost Converter For Photovoltaic Application Using Μ-Synthesis Approach, Badur Mueedh Alharbi

Graduate Theses and Dissertations

The high demand of energy efficiency has led to the development power converter topologies and control system designs within the field of power electronics. Recent advances of interleaved boost converters have showed improved features between the power conversion topologies in several aspects, including power quality, efficiency, sustainability and reliability.

Interleaved boost converter with multi-phase technique for PV system is an attractive area for distributed power generation. During load variation or power supply changes due to the weather changes the output voltage requires a robust control to maintain stable and perform robustness.

Connecting converters in series and parallel have the advantages …

ℓ-Ctp: Utilizing Multiple Agents To Find Efficient Routes In Disrupted Networks, Andrew Alseth

Graduate Theses and Dissertations

Recent hurricane seasons have demonstrated the need for more effective methods of coping with flooding of roadways. A key complaint of logistics managers is the lack of knowledge when developing routes for vehicles attempting to navigate through areas which may be flooded. In particular, it can be difficult to re-route large vehicles upon encountering a flooded roadway. We utilize the Canadian Traveller’s Problem (CTP) to construct an online framework for utilizing multiple vehicles to discover low-cost paths through networks with failed edges unknown to one or more agents a priori. This thesis demonstrates the following results: first, we develop the …

Effects Of Short Season Irrigation On Pasture Yield And Predicting Yield With Sentinel-2 Satellite, Ihsan Bugra Bugdayci

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Deficit irrigation can reduce agriculture water use making additional water available for other uses. This study looked at multi-year impacts of deficit irrigation on pasture yield. The results show that that early irrigation provides the most benefit to cool season pastures and late season irrigation only had small impacts on yield. According to this research, irrigation water can be saved without impacting the yield importantly.

Remote sensing techniques are becoming a part of agriculture. Yield predictions are important for the farmers and others involved with agriculture. In this research, relationships between the normalized difference vegetation index (NDVI) calculated from remotely …

Assessing The Methodological Quality Of Aviation Research: A Content Analysis Of Articles Published In Subscription And Open Access Aviation Journals 2014-2016, Isa Tuncman

Theses and Dissertations

The purpose of the study was to determine to what extent aviation research articles were consistent with commonly recommended research protocols. Using a purposive sampling strategy, two subscription and five open access journals published from 2014 to 2016 were targeted, and 139 articles were reviewed using a category based, researcher-developed coding form grounded in commonly accepted research practices presented in educational research methods textbooks. The form reflected models from the medical research community and employed a 3-point scoring rubric: 0 = Not Reported, 1 = Inadequate, and 2 = Adequate. At least two coders reviewed each article, and corresponding Krippendorff …

A Parametric Evaluation Of Iot Applications To Freight Transportation Using Model-Based Systems Engineering, Paul George Crawford

Theses and Dissertations

Industrial Internet of Things or IIoT consists of computing and communication at the operational edge of a value chain. Applications span manufacturing, energy, and transportation, among others. In the transportation context, IIoT translates to connected vehicle architecture and ITS applications. Current trends in communication allow more applications and devices to contribute to functions traditionally allocated to transportation ITS infrastructure. This poses challenges to design engineers to prototype emerging technologies in the existing transportation context and reduce integration, validation, and time to market. Model-based systems engineering is crucial step for IIoT deployment since it allows for a feature-rich digital representation of …