Engineering Commons^™

Pd-Modified Cuo-Zno-Al2o3 Catalysts Via Mixed-Phases-Containing Precursor For Methanol Synthesis From Co2 Hydrogenation Under Mild Conditions, Xiao Fan, Kaiying Wang, Xiaoqing He, Shiguang Li, Miao Yu, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A series of palladium-modified (Pd-modified) CuO-ZnO-Al2O3 (CZA) catalysts with various Pd loadings (0.3 wt% to 2.4 wt%) were prepared using the wetness impregnation method, on two CZA supports with different structures that are CZA-aged precursor composed of a mixture of zincian-malachite and hydrotalcite-like phases (CZA-zH), and CuO-ZnO-Al2O3 metal oxide nanoparticles (CZA-MO). Enhancement on catalytic activity can be observed on both Pd-modified CZA catalysts in a temperature range of 180–240 °C for methanol synthesis via CO2 hydrogenation. Pd/CZA-zH catalysts exhibited a more efficient and stable production of methanol at a relatively low reaction temperature of 180 °C for 100 hrs. of …

Weakly Supervised Attention-Based Recognition Under Spectral, Turbulence, And Resource Variations, Kshitij Naresh Nikhal

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

While supervised optimization paradigms are ubiquitous across diverse recognition systems, the risk of over-fitting and increasing bias have limited their applicability.

This dissertation focuses on unsupervised learning—learning without precisely curated data—and argues that unsupervised learning methods can enable both discriminability and generalizability. Through the use of attention-based machine learning and advanced clustering, unsupervised methods are able to focus on fine-grained information in images without any explicit supervision. The dissertation introduces a domain-bridging framework for tasks like cross-spectrum matching and long-range recognition, utilizing intra-domain clustering and inter-domain matching to generate pseudo-labels. Additionally, a hash-based network is proposed to accelerate the search …

An Impedance-Source-Based Soft-Switched High Step-Up Dc-Dc Converter With An Active Clamp, Saeed Habibi, Ramin Rahimi, Mehdi Ferdowsi, Pourya Shamsi

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes a high step-up dc-dc converter based on a trans-inverse impedance-source structure, in which the voltage gain of the converter is increased by using a lower number of turns ratio of the coupled inductors (CI) windings. The proposed converter achieves a very high voltage gain and a very low voltage stress on the switches. An active clamp is incorporated into the topology of the proposed converter, helping to absorb the energy of the leakage inductances of the CI, and to recycle that energy to the output of the converter to further increase the voltage gain. Furthermore, the active …

Toward Smart And Sustainable Cement Manufacturing Process: Analysis And Optimization Of Cement Clinker Quality Using Thermodynamic And Data-Informed Approaches, Jardel P. Gonçalves, Taihao Han, Gaurav Sant, Narayanan Neithalath, Jie Huang, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Cement manufacturing is widely recognized for its harmful impacts on the natural environment. In recent years, efforts have been made to improve the sustainability of cement manufacturing through the use of renewable energy, the capture of CO₂ emissions, and partial replacement of cement with supplementary cementitious materials. To further enhance sustainability, optimizing the cement manufacturing process is essential. This can be achieved through the prediction and optimization of clinker phases in relation to chemical compositions of raw materials and manufacturing conditions. Cement clinkers are produced by heating raw materials in kilns, where both raw material compositions and processing conditions …

Advances In Growth, Doping, And Devices And Applications Of Zinc Oxide, Vishal Saravade, Zhe Chuan Feng, Manika Tun Nafisa, Chuanle Zhou, Na Lu, Benjamin Klein, Ian T. Ferguson

Electrical and Computer Engineering Faculty Research & Creative Works

Zinc oxide is a breakthrough multifunctional material of emerging interest applicable in the areas of electronics, computing, energy harvesting, sensing, optoelectronics, and biomedicine. Zno has a direct and wide bandgap and high exciton binding energy. It is nontoxic, earth-abundant, and biocompatible. However, the growth and characterization of high-quality zno has been a challenge and bottleneck in its development. Efforts have been made to synthesize device-quality zinc oxide and unleash its potential for multiple advanced applications. Zno could be grown as thin films, nanostructures, or bulk, and its properties could be optimized by tuning the growth techniques, conditions, and doping. Zinc …

Plc Course Development, Leonard Hernandez, Jacqueline Grace Radding

Electrical Engineering

The goal of this project is to design and construct the first lab experiment for the newly developed EE435 laboratory course. The experiment entails PLC programming to automate LED lighting in a simulated building. Starting with why PLCs are used, how to use the interface of EcoStruxure Control Expert V15.0 and practice using logic to control the dimming of a Light Emitting Diode (LED) to sustain a certain number of lumens consistent in a zone. Through the lab manual developed in this project, students will gain experience of creating logic designs using Function Block Diagram (FBD) and learn the layout …

Improvements Of Hybrid Ac/Dc House Prototype, Arden Abude

Electrical Engineering

This is an iteration from previous designs of the Hybrid AC/DC House with a systematic addition of a portable AC power supply unit. This iteration for the Hybrid AC/DC House is an innovation of independence for sustainable housing solutions. It will serve as an alternative for rural communities needing power to rely on self-sustainable microgrids rather than large-scale AC electric grids. The addition of a portable AC power supply would allow the microgrid to remove its reliance on AC power from the larger grid and would elevate the system to complete energy independence. The microgrid has DC power generated from …

Uncovering The Critical Drivers Of Blockchain Sustainability In Higher Education Using A Deep Learning-Based Hybrid Sem-Ann Approach, Mohammed Alshamsi, Mostafa Al-Emran, Tugrul Daim, Mohammed A. Al-Sharafi, Gulin Idil Sonmezturk Bolatan, Khaled Shaalan

Engineering and Technology Management Faculty Publications and Presentations

The increasing popularity of Blockchain technology has led to its adoption in various sectors, including higher education. However, the sustainability of Blockchain in higher education is yet to be fully understood. Therefore, this research examines the determinants affecting Blockchain sustainability by developing a theoretical model that integrates the protection motivation theory (PMT) and expectation confirmation model (ECM). Based on 374 valid responses collected from university students, the proposed model is evaluated through a deep learning-based hybrid structural equation modeling (SEM) and artificial neural network (ANN) approach. The PLS-SEM results confirmed most of the hypotheses in the proposed model. The sensitivity …

Exploratory Analysis Of Cislunar Disposal Options For Select L1 And L2 Orbit Families, Rene Velazquez

Theses and Dissertations

The purpose of this research is to characterize the disposal options available for the planar and out of plane orbit families near the Moon. These options are meant to provide the impending Space Race around the cislunar regime a method to mitigate debris in the future. The disposal options are built upon a Sphere of Influence (SOI) reachability concept from a Circular Restricted Three-Body Problem (CR3BP). The SOI reachability will be based on the maneuver applied on a closed orbit in the velocity direction of the rotating frame. The post-maneuver trajectories will be propagated for 180 days and transformed into …

Optimal Trajectory Solutions For Unmanned Pursuer/Evader Offensive Counterair Including Engagement Zone, Alexander Hansen

Theses and Dissertations

This work considers a two-actor scenario of a faster, unmanned pursuer with an engagement zone (EZ) and a non-maneuvering mobile evader. The pursuer aims to capture an evader with a circular EZ. The EZ is dynamic and shifts as a function of the evader’s velocity vector. As the evader’s strategy changes, the EZ relative to the pursuer adjusts based on relative heading and speed of the two agents. Using nonlinear optimal control techniques, the optimal trajectory and minimum time to engage the evader are determined for various pursuer initial headings and positions through MATLAB simulation. The results build a control …

Preliminary Architecture Assessment Of Lunar Surface Sensors For Cislunar Ssa, Clint J. Spesard

Theses and Dissertations

The exploration of the lunar and cislunar realm is becoming increasingly active as several entities, private and public, foreign and domestic, set their sights beyond traditional Earth-centered space operations. Along with this renewed activity is a growing need for comprehensive Space Situational Awareness (SSA) and Space Traffic Management (STM) in the inherently chaotic cislunar system. This thesis seeks to embolden the study of cislunar SSA by considering the lunar-surface as a platform from which to conduct optical SSA. In this thesis, a lunar-based SSA system is heuristically optimized via a genetic algorithm through three separate implementations. All surface locations considered …

End-User Device Management In The Air And Space Forces, Joshua Bonvissuto

Theses and Dissertations

When achieving technical superiority is a matter a national security, it is critical that the Department of the Air Force (DAF) employs a robust Information Technology Asset Management (ITAM) strategy that maximizes mission effectiveness. Since 2022, the Office of the Chief Information Officer (SAF/CN) has been developing a plan to transform the Air Force’s ITAM strategy, primarily intending to centralize End User Device (EUD) procurement to the DAF level. For this study, a Delphi study was conducted to gather expert opinions on key aspects of SAF/CN’s new ITAM strategy to identify strengths, weaknesses, and implementation challenges. This research provides valuable …

Utilization Of The System Engineering Design Process To Design And Test A Low-Cost Infectious Aerosol Control Mechanism For Patient Aeromedical Evacuation, Sara Shaghaghi

Theses and Dissertations

The aeromedical evacuation of military patients is a critical component of care for Armed Forces members. The Air Force’s ability to transport patients relies on the technology and systems available. A vital transport responsibility is keeping the patient and medical personnel safe during transport. The historical and legacy systems provide reliable transport mechanisms for the Armed Forces’ patients infected with high-level biological agents, but drawbacks must be considered. This dissertation will discuss the development, conceptual design, and initial evaluation of a new low-cost, litter-mounted patient transport system, Biological-Mitigation in Patient Transport (B-MIPT), using the “V” model of the system engineering …

Advanced Oxidation Of Methyl Tert Butyl Ether With Ultraviolet Light Emitting Diodes, Aaron R. Neal

Theses and Dissertations

Methyl Tert-Butyl Ether (MTBE) is a volatile, soluble, organic compound introduced to gasoline within the United States as a fuel oxygenator in 1979. MTBE is a common groundwater pollutant due to its high water solubility and resistance to bio-degradation; it commonly infiltrates groundwater sources via leaking underground storage tanks or fuel spills. This research employed ultraviolet light emitting diodes (UV-LEDs) and hydrogen peroxide (H₂O₂) induced advanced oxidation process (AOP) to treat MTBE contaminated water at the bench scale. Using four H₂O₂:MTBE molar peroxide ratios (100:1, 200:1, 400:1, 500:1), MTBE degradation was induced …

Origami Application And Attitude Control Investigation Of Space-Based Mirror System, David J. Garcia

Theses and Dissertations

Imaging and inspecting Resident Space Objects (RSO) have gained increasing importance in Space Situational Awareness (SSA) missions. These missions are driven by the necessity to perform satellite repairs, refueling, de-orbiting, and orbital debris reduction. However, the challenging lighting conditions in space often hinder these tasks. To overcome this challenge, a novel concept has been proposed—deploying mirrors from servicer satellites. These mirrors would harness solar energy to illuminate dimly-lit RSOs, enabling imaging, inspection, repair, and refueling operations. In this context, servicer satellites play a pivotal role in controlling the reflected light beam and precisely positioning themselves to illuminate RSOs effectively. Notably, …

3- And 6-Degree-Of-Freedom Investigation Of Aerobraking To Support Cislunar And Planetary Operations, Erica C. Higginbotham

Theses and Dissertations

The first aerobraking experiment occurred in 1991 as part of the Hiten spacecraft’s cislunar survey mission, while the first non-Earth aerobraking experiment occurred in 1993 as part of the Magellan spacecraft’s mission to Venus. Although making only two trans-atmospheric passes to reduce its apogee altitude, the success of Hiten’s experiment led to the implementation of aerobraking by Magellan, reducing its orbit from elliptical to nearly circular over a span of 70 Earth days by leveraging aerodynamic drag to reduce its orbital energy via transiting the upper region of Venus’ atmosphere. The Magellan experiment helped prove the viability of aerobraking for …

Evasion Strategies For Space Engagements With Unknown Pursuer Objectives, Stephanie L. Halsey

Theses and Dissertations

Realistic simulations provide a tool for operators to understand space tactics and also serve to inform decisions on the requirements of current spacecraft technologies. This research uses simulation to gain a better understanding of one-on-one orbital conflicts through orbital differential games and linear quadratic games. The results of this research find that a simple strategy for an evading spacecraft to successfully evade a more-capable pursuing satellite for a variety of potential goals is to thrust perpendicular to the direction of the pursuer. Specific estimation requirements to accurately determine the objective of the pursuer and successfully evade in a realistic scenario …

A Nonlinear Least Squarees Approach To Orbit Determination In Near-Earth Orbits, Ryan M. Vorst

Theses and Dissertations

This work explores relevant scenarios to implement a Frequency on Arrival method using nonlinear least squares to determine a transmitting satellite’s orbit based only on measurements of the received radio frequency. Multiple relevant collection geometries, such as a target in prograde low earth orbit, in retrograde low earth orbit, in sun synchronous orbit, in near-perigee highly elliptical orbit, in near-apogee highly elliptical orbit, and in geosynchronous orbit, are simulated to collect theoretical received frequency data. Once data collection has been simulated, the theoretical apparent frequencies recorded are used in a nonlinear least squares method with differential correction to find a …

Evaluating Butterfly Orbits In The Earth-Moon Corridor For Ssa, Lunar Surface Surveillance, And Cislunar Disposal, Contessa G. Norris

Theses and Dissertations

The increased space activity in the region of cislunar space has created a high demand to identify, track, and monitor Resident Space Objects (RSOs) and provide cislunar disposal routes for RSOs. This research investigates the practicality of various satellite maneuvers between orbits chosen from the butterfly and dragonfly orbit families. Several simulated trajectories are compared to show the feasibility of performing a maneuver in cislunar and lunar space between the L1 and L2 Lagrange points. Additionally, lunar surface space situational awareness (SSA) capabilities of northern and southern butterfly (BN/BS) orbits were evaluated and compared to provide the most favorable dynamic …

Exhaust Manifold Pressure As Engine Tuning Parameter, Kieran Truth Cunningham, Adam Sullivan Mathews, Connor Richard Smullen

Mechanical Engineering

In this project, the exhaust manifold absolute pressure (EMAP) of a 1986 Toyota Corolla was analyzed across a variety of load cases and was compared with the mass air flow (MAF) of the intake, simultaneously. Correlations were found in the trends of EMAP and MAF sensor readings that may prove helpful in tuning engines that have difficulty in accommodating a MAF sensor. These correlations were found in areas of the powerband where aftermarket tuned engines typically have poor airflow sensing. An equation was developed to spoof MAF input using EMAP and other engine operating parameters.

Biobesoothe, Noah M. Taylor, Jillian Trilevsky, Sam Rosenkranz

Biomedical Engineering

This document details the background, design process, and functional prototype for the BioBesoothe senior project. The project aimed to address difficulties with self-regulation in children with autism. It focused on encouraging even, slow breathing to activate the parasympathetic nervous system, which in turn lowers heart rate, blood pressure, and stress levels. The project was guided by research into ways to achieve an appropriate breathing rate. In addition to functionality, emphasis was placed on engagement, ergonomics, and affordability. It was highly important for this product to be engaging to hold the interest of its patients and allow for extended periods of …

Pitot Tube Test Bench, Jesus Perez, Zachary Owen, Adrian Lopez

Mechanical Engineering

This Final Design Review documents the senior design project carried out by a team of Mechanical Engineering students attending California Polytechnic State University, San Luis Obispo for Roger Benham, and his company Leak Control Services Inc. The requirement was to design, build, and validate the performance of a test fixture that quantifies the performance characteristics of flow rate and pressure drop of different pitot tube designs to be used in a chemical dispensing application for Mr. Benham. This document includes relevant background research on the need for the fixture as well as relevant technical research. This document also contains objectives …

Asme Electric-Human Powered Vehicle (Ehpv) Project, George Bernat, Roman Bradley, Casey Pickett, Paul Mansfield

Mechanical Engineering

This report documents the collaborative efforts of the senior design team and the Cal Poly Human Powered Vehicles Club in creating an electric-assisted human powered vehicle tailored for participation in ASME's e-HPV Spring 2024 competition. Delving into a comprehensive account of the project's lifecycle, the report outlines the iterative stages of ideation and design, the manufacturing processes, testing , and subsequent refinements undertaken by the team. Additionally, it provides analysis of the project management strategies employed, as well as an overall appraisal of successes, setbacks, and areas improvement. As a result of the project, the vehicle (shown below) was successfully …

Evaluation Of Ndot’S Sediment Barrier Practices Using Performance Data, Michael A. Perez, Wesley N. Donald, J. Blake Whitman, Brian G. Roche

Nebraska Department of Transportation: Research Reports

To protect waterways adjacent to construction projects with disturbed land, a 50 ft (15 m) vegetated buffer or equivalent sediment controls are required. However, there is little guidance on the effectiveness of vegetated buffers in removing sediment or how sediment barriers can aid shorter buffers or replace buffers. A modeling methodology was developed and used to determine the performance of 11,664 50 ft (15 m) vegetated buffer configurations with Nebraska conditions; sediment capture averaged 92.6% and ranged from 18.5% to 99.5%. To determine the performance of Nebraska Department of Transportation standard and modified sediment barrier installations, a large-scale testing methodology …

Local Strain Quantification Of A Porous Carbon Fiber Network Material, Robert N Quammen, Paul F. Rottmann

Chemical and Materials Engineering Faculty Publications

While porous materials’ wide range of attractive functional properties have led to their development for a variety of applications, their intrinsically stochastic microstructures prevent straightforward approaches to predicting their mechanical behavior. This is attributed to the mechanisms that govern the macroscale behavior of these materials operating on multiple microstructure-specific length scales spanning several orders of magnitude. The goal of this work was to experimentally observe these operative deformation mechanisms to better improve the development of mechanism-informed models that more accurately predict the behavior of these materials. In this study compression tests were conducted on a porous carbon fiber network material. …

Characterization Of Microstructural And Mechanical Properties Of 17-4 Ph Stainless Steel By Cold Rolled And Machining Vs. Dmls Additive Manufacturing, Pablo Moreno-Garibaldi, Melvyn Alvarez-Vera, Juan Alfonso Beltrán-Fernández, Rafael Carrera-Espinoza, Héctor Manuel Hdz-García, J. C. Díaz-Guillen, Rita Muñoz-Arroyo, Javier A. Ortega, Paul Molenda

Mechanical Engineering Faculty Publications

The 17-4 PH stainless steel is widely used in the aerospace, petrochemical, chemical, food, and general metallurgical industries. The present study was conducted to analyze the mechanical properties of two types of 17-4 PH stainless steel—commercial cold-rolled and direct metal laser sintering (DMLS) manufactured. This study employed linear and nonlinear tensile FEM simulations, combined with various materials characterization techniques such as tensile testing and nanoindentation. Moreover, microstructural analysis was performed using metallographic techniques, optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results on the microstructure for 17-4 PH DMLS stainless steel reveal …

Distributed Solar Generation: Current Knowledge And Future Trends, Gasser G. Ali, Islam H. El-Adaway

Civil Engineering Faculty Publications

Distributed solar generation (DSG) has been growing over the previous years because of its numerous advantages of being sustainable, flexible, reliable, and increasingly affordable. DSG is a broad and multidisciplinary research field because it relates to various fields in engineering, social sciences, economics, public policy, and others. Developing a holistic understanding of the state of research related to DSG can be difficult. Motivated to provide that understanding, the goal of this paper is to explore current and emerging multidisciplinary research trends associated with DSG. To achieve that, (1) a large data set of approximately 66,000 publications was collected; (2) the …

Erosion Wear Characterisation Of An Open Ductile Iron Butterfly Valve Subjected To Aluminium Oxide Particle Slurry Flow, Prashan Perera, Kevin Hayward, Ferdinando Guzzomi, Ana Vafadar

Research outputs 2022 to 2026

This study attempts to identify the most erosion-sensitive valve locations due to aluminium oxide particle impingement under various pressure drops and valve closing angles, utilising the Ansys discrete phase model (DPM). Additionally, this research explores the feasibility of integrating laser scanning technology into the fields of tribology and particle erosion analysis. The results indicate higher erosion damage on the top valve surface due to the direct effects of particle velocity and impingement angles compared to the underside of the valve, where particle trajectories are highly affected by turbulence. Moreover, smaller closing angles proved to be detrimental to valve service life, …

Multi-Season Mobile Monitoring Campaign Of On-Road Air Pollution In Bengaluru, India: High-Resolution Mapping Estimation Of Quasi-Emission Factors, Adithi Upadhya, Meenakshi Kushwaha, Pratyush Agrawal, Jonathan D. Gingrich, Jai Asundi, Sreekanth V, Julian Marshall, Joshua Apte

Faculty Work Comprehensive List

Mobile monitoring can supplement regulatory measurements, particularly in low-income countries where stationary monitors’ density is low. Here, we report results from a ~year-long mobile monitoring campaign of on-road black carbon (BC) mass concentration, ultrafine particle (UFP) number concentration, and carbon dioxide (CO2) in Bengaluru, India. The study route included ~150 unique kms covering urban and peri-urban residential neighborhoods and the central business district (CBD); ~22 repeat measurements were made per monitored road-segment, covering most seasons. After cleaning the data for known instrument artifacts and sensitivities, we generated 30 m high-resolution stable ‘data only’ spatial maps of BC, UFP, and CO2 …

Pcor Partnership Atlas, Wesley D. Peck, Kari Suedel, Kyle A. Glazewski, Kevin C. Connors, James A. Sorensen, Charles D. Gorecki, Brian P. Kalk, John A. Harju

EERC Maps and Infographics

The Plains CO₂ Reduction (PCOR) Partnership Atlas provides a profile of CO₂ sources and potential storage locations across the PCOR Partnership region. The revised sixth edition of the Atlas provides an up-to-date look at PCOR Partnership initiative activities, including additional regional characterization and updates on commercial projects. Additional background information on carbon capture, utilization, and storage (CCUS) is included to give a better understanding of how CCUS addresses concerns about climate change while allowing future energy needs to be met.