Engineering Commons^™

Floating Gate Schottky Junction Solar Cells With Improved Output Power, Amirhossein Ghods, Vishal Saravade, Andrew Woode, Corey Lerner, Chuanle Zhou, Ian T. Ferguson

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, the concept of floating gate Schottky junction (FGSJ) solar cell with improved photovoltaic properties, compared to those of the conventional Schottky junction solar cell, is proposed. The floating gate junction is electrically isolated from the current collection junction in order to prevent reduction in the barrier height at the floating gate contact from load voltage. The unaffected barrier height at the floating gate junction leads to a more effective separation of photo-generated electron-hole pairs, and therefore, a better photovoltaic response. Single junction FGSJ solar cells based on n-type GaAs with different doping concentration levels and gate contact …

First-Principles Studies Of Mof Absorption On Hydroxylated And Non-Hydroxylated Metal Oxide Surfaces And Implications For Atomic Layer Deposition Of Mos2, Matthew Lawson, Elton Graugnard, Lan Li

Materials Science and Engineering Faculty Publications and Presentations

Significant interest in two-dimensional transition metal dichalcogenides has led to numerous experimental studies of their synthesis using scalable vapor phase methods, such as chemical vapor deposition (CVD) and atomic layer deposition (ALD). ALD typically allows lower deposition temperatures, and nucleation of chemical precursors requires reactions with surface functional groups. A common first-principles method used to study ALD modeling is the calculation of activation energy for a proposed reaction pathway. In this work we calculated the partial charge densities, local density of states (LDoS), Bader charge analysis, adsorption energies, and charge density difference using density functional theory (DFT) to investigate the …

Interface Structure And Luminescence Properties Of Epitaxial Pbse Films On Inas(111)A, Kevin D. Vallejo, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

Epitaxial heterostructures of narrow-gap IV-VI and III-V semiconductors offer a platform for new electronics and mid-infrared photonics. Stark dissimilarities in the bonding and the crystal structure between the rocksalt IV–VIs and the zincblende III–Vs, however, mandate the development of nucleation and growth protocols to reliably prepare high-quality heterostructures. In this work, we demonstrate a route to single crystal (111)-oriented PbSe epitaxial films on nearly lattice-matched InAs (111)A templates. Without this technique, the high-energy heterovalent interface readily produces two populations of PbSe grains that are rotated 180° in-plane with respect to each other, separated by rotational twin boundaries. We find that …

Low-Cost Modal Identification Sensors For Bridge Field Testing, Daniel Linzell, Saaed Eftekhar Azam, Samira Ardani, Ahmed E Rageh

Nebraska Department of Transportation: Research Reports

This report provides a framework for experimental load rating of bridges via inclusion of low-cost dynamic sensors and dynamic tests. Currently 25% of the bridges in Nebraska are posted for live load. According to the National Bridge Inventory (NBI) in 2012, 93% of all postings in the US were based analytical load ratings, 7% were posted using field evaluation and engineering judgement, and 1% were posted using experimental load rating methods.

Instrumentation costs and traffic interruptions can be problematic when load testing is necessary to accurately assess in-situ bridge live load capacity. Recent advances in (i) sensing technology and (ii) …

State Energy Research Center, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the State Energy Research Center (SERC). Highlights the Energy & Environmental Research Center’s technology development, skilled workforce, and funding sources. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Singapore Airlines: Profit Recovery And Aircraft Allocation Models During The Covid-19 Pandemic, Michelle L. F. Cheong, Ulysses M. Z. Chong, Anne N. T. A. Nguyen, Su Yiin Ang, Gabriella P. Djojosaputro, Gordy Adiprasetyo, Kendra L. B. Gadong

Research Collection School Of Computing and Information Systems

COVID-19 has severely impacted the global aviation industry, causing many airlines to downsize or exit the industry. For airlines which attempt to sustain their operations, they will need to respond to the increase in passenger and cargo demand, as countries recover slowly from the crisis due to the availability of vaccines. We built a series of spreadsheet models to first project the COVID-19 recovery rates by countries from 2021 to 2025, then forecast the passenger and cargo demand, using historical data as base figures. Using the financial and operation data, the revenue, expense, and profit can be projected, then an …

A Comparison Of Porphyrin Photosensitizers In Photodynamic Inactivation Of Rna And Dna Bacteriophages, Joe Heffron, Matthew Bork, Brooke K. Mayer, Troy Skwor

Civil and Environmental Engineering Faculty Research and Publications

Effective broad-spectrum antiviral treatments are in dire need as disinfectants and therapeutic alternatives. One such method of disinfection is photodynamic inactivation, which involves the production of reactive oxygen species from dissolved oxygen in response to light-stimulated photosensitizers. This study evaluated the efficacy of functionalized porphyrin compounds for photodynamic inactivation of bacteriophages as human virus surrogates. A blue-light light emitting diode (LED) lamp was used to activate porphyrin compounds in aqueous solution (phosphate buffer). The DNA bacteriophages ΦX174 and P22 were more resistant to porphyrin TMPyP photodynamic inactivation than RNA bacteriophage fr, with increasing rates of inactivation in the order: ΦX174 …

Fiber Optic Sensor Embedded Smart Helmet For Real-Time Impact Sensing And Analysis Through Machine Learning, Yiyang Zhuang, Qingbo Yang, Taihao Han, Ryan O'Malley, Aditya Kumar, Rex E. Gerald Ii, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Background: Mild traumatic brain injury (mTBI) strongly associates with chronic neurodegenerative impairments such as post-traumatic stress disorder (PTSD) and mild cognitive impairment. Early detection of concussive events would significantly enhance the understanding of head injuries and provide better guidance for urgent diagnoses and the best clinical practices for achieving full recovery. New method: A smart helmet was developed with a single embedded fiber Bragg grating (FBG) sensor for real-time sensing of blunt-force impact events to helmets. The transient signals provide both magnitude and directional information about the impact event, and the data can be used for training machine learning (ML) …

Time-Dependent System Reliability Analysis With Second-Order Reliability Method, Hao Wu, Zhangli Hu, Xiaoping Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

System reliability is quantified by the probability that a system performs its intended function in a period of time without failures. System reliability can be predicted if all the limit-state functions of the components of the system are available, and such a prediction is usually time consuming. This work develops a time-dependent system reliability method that is extended from the component time-dependent reliability method using the envelope method and second-order reliability method. The proposed method is efficient and is intended for series systems with limit-state functions whose input variables include random variables and time. The component reliability is estimated by …

Adaptive Kriging Method For Uncertainty Quantification Of The Photoelectron Sheath And Dust Levitation On The Lunar Surface, Xinpeng Wei, Jianxun Zhao, Xiaoming He, Zhen Hu, Xiaoping Du, Daoru Han

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents an adaptive Kriging based method to perform uncertainty quantification (UQ) of the photoelectron sheath and dust levitation on the lunar surface. The objective of this study is to identify the upper and lower bounds of the electric potential and that of dust levitation height, given the intervals of model parameters in the one-dimensional (1D) photoelectron sheath model. To improve the calculation efficiency, we employ the widely used adaptive Kriging method (AKM). A task-oriented learning function and a stopping criterion are developed to train the Kriging model and customize the AKM. Experiment analysis shows that the proposed AKM …

The Corrosion Of Stainless Steel Made By Additive Manufacturing: A Review, Gyeongbin Ko, Wooseok Kim, Kyungjung Kwon, Tae-Kyu Lee

Mechanical and Materials Engineering Faculty Publications and Presentations

The advantages of additive manufacturing (AM) of metals over traditional manufacturing methods have triggered many relevant studies comparing the mechanical properties, corrosion behavior, and microstructure of metals produced by AM or traditional manufacturing methods. This review focuses exclusively on the corrosion property of AM-fabricated stainless steel by comprehensively analyzing the relevant literature. The principles of various AM processes, which have been adopted in the corrosion study of stainless steel, and the corrosion behaviors of stainless steel depending on the AM process, the stainless steel type, and the corrosion environment are summarized. In this comprehensive analysis of relevant literature, we extract …

Development Of An Internet Of Things (Iot) Enabled Novel Wireless Multi Sensor Network For Infield Crop Monitoring, Nipuna Chamara

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

Multispectral imaging systems on satellite, aerial, and ground platforms are used commonly to monitor in-field crops in precision agriculture by farmers and researchers. Limited spatial and temporal resolution and weather dependence of the data collection are two main disadvantages of these methods. In-field sensor networks can continuously monitor environmental and plant physiological parameters by leveraging low-power computation and long-range communication technologies. We built and tested a novel sensor network equipped with soil moisture, multispectral and RGB imaging sensors in an experimental soybean field at Eastern Nebraska Research and Extension Center, NE, USA. 10 down-looking and 1 up-looking sensor node were …

Solar Soiling Mitigation, Claire Desmith

Electrical Engineering

This senior project aims to mitigate performance losses that occur in Photovoltaic (PV) systems due to soiling of the panels. Soiling is the natural occurrence of debris accumulation on panels, depending on local climate conditions. Soiling loss refers to efficiency lost due to dirt and dust accumulation on the panels. The debris reduces system output by shading on a smaller scale. In addition to uniform soiling, corner soiling is observed in framed modules as debris collects in the corners of the modules. While solutions currently exist to clean modules to mitigate soiling losses, these solutions are often expensive and time …

Enterprise Architecture Transformation Process From A Federal Government Perspective, Tonia Canada, Leila Halawi

Publications

The need for information technology organizations to transform enterprise architecture is driven by federal government mandates and information technology budget constraints. This qualitative case study aimed to identify factors that hinder federal government agencies from driving enterprise architecture transformation processes from a compliancy to a flexible process. Common themes in interviewee responses were identified, coded, and summarized. Critical recommendations for future best practices, including further research, were also presented.

Fatigue And Its Management In The Aviation Industry, With Special Reference To Pilots, Rajee Olaganathan, Timothy B. Holt, Jackie Luedtke, Brent D. Bowen

Publications

Abstract Fatigue is a significant contributing factor that reduces human ability and leads to accidents and threatens the safety of aircraft and human lives. Approximately 70% of fatal accidents that occur in commercial aviation operations are due to human factors. More specifically, crew fatigue contributes to nearly 15 to 20% of the accidents (Akerstedt, 2000). These accidents and incidents are associated with pilot fatigue because of the long duty periods, disruption of circadian rhythms, and inadequate sleep that are common among both commercial and military pilots. Though fatigue is seen in all the disciplines associated with the aviation industry, this …

Spectral Induced Polarization Study On Enzyme Induced Carbonate Precipitations: Influences Of Size And Content On Stiffness Of A Fine Sand, Bate Bate, Junnan Cao, Chi Zhang, Na Hao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Heterogeneity in either chemically or microbiologically induced carbonate-based ground improvement methods is a major obstacle in engineering application. Spectral induced polarization (SIP), an innovative and nondestructive method, which has demonstrated promise in monitoring microbial activity, was used in this study to monitor enzyme induced carbonate precipitation (EICP). The complex conductivities, together with the shear wave velocities (Vs), of an EICP modified sand were monitored using a self-developed spectral induced polarization–bender element column. The mean precipitate size was calculated by relaxation time (τ) and the Schwarz equation. The precipitate contents were calculated by cumulative gamma distribution function on the global polarization …

The Effects Of Remotely Piloted Aircraft Command And Control Latency During Within-Visual-Range Air-To-Air Combat, David Thirtyacre

Doctoral Dissertations and Master's Theses

The type of military missions conducted by remotely piloted aircraft continues to expand into all facets of operations including air-to-air combat. While future within-visual-range air-to-air combat will be piloted by artificial intelligence, remotely piloted aircraft will likely first see combat. The purpose of this study was to quantify the effect of latency on one-versus-one, within-visual-range air-to-air combat success during both high-speed and low-speed engagements. The research employed a repeated-measures experimental design to test the various hypothesis associated with command and control latency. Participants experienced in air-to-air combat were subjected to various latency inputs during one-versus-one simulated combat using a virtual-reality …

Project G.H.O.S.T., Matthew Morell, Austin Conrad, Zackeris Gordon, Conan Estes

Mechanical Engineering

Project G.H.O.S.T aimed to produce a model transmission with a control system for high performance/racing electric vehicles to utilize the full capability of the electric motor at higher speed applications. Current electric vehicles have a large amount of torque and use a fixed gear ratio that compromises between both high and low speeds with performance peaking around 65 miles per hour. A typical electric motor used in this application has approximately 1800 ft-lbs of torque up to 5,000 rpm. Past approximately 5,000 rpm, the torque rapidly drops off and so does the overall vehicle performance. Though transmissions exist that could …

Smud Solar Regatta, Logan Garby, Nam Le, Jacob Singer, Alejandro Carrera, Laura Casas

Mechanical Engineering

The Sacramento Municipal Utility District (SMUD) hosts the Solar Regatta every year in Rancho Seco, CA, a competition which consists of teams building a solar powered boat to compete in three races: the sprint race, endurance race, and slalom race. The Cal Poly Solar Regatta team was informed mid-project by SMUD that the competition has been canceled once again for spring 2021, but the team decided to move forward with the construction of the boat. The previous Cal Poly team from 2019/2020 designed the hull and propulsion system of the boat. The 2020/2021 team worked with the previous team in …

Enduro Campers, Ryan J. Shomsky, Alexander W. Horst, Kevin S. Pickering, Jackson L. Aplanalp, Luke Arana, Will Firestone

Mechanical Engineering

The Enduro Campers senior project team (Formerly known as Lobo Campers senior project team) was recruited by Mr. Leif Stein to assist in the design, manufacturing, and testing of the materials and components of his company’s expedition box camper. The two main focuses of the project, divided into two sub-teams, were on the testing and manufacturing process of the materials used in the camper, and on the design and analysis of the camper’s access door, step box, and other subsystems.

The focus of the materials analysis and manufacturing team was based around the design parameter to use composite sandwich panels …

Final Design Report Cal Poly Wind Power - Balancing System, Caleb Seth Cross, Ethan Andrew Czuppa

Mechanical Engineering

The Cal Poly Wind Power club is anticipating joining the annual Collegiate Wind Competition in the year 2021. This competition hosts schools from all around the country, who meet and compete against each other by testing the wind turbines they have made throughout the academic school year. Tasks included in the competition test the wind turbine’s efficiency, power generation, overall design, and stability in extreme conditions.

Cal Poly is planning to implement a formal balancing system to support their 2021 wind turbine. Our senior project team undertook mitigating mass imbalance in the wind turbine; mass imbalance occurs when the center …

A Method For Visualizing The Structural Complexity Of Organizational Architectures, Jacob Michael B. King

Master's Theses

To achieve a high level of performance and efficiency, contemporary aerospace systems must become increasingly complex. While complexity management traditionally focuses on a product’s components and their interconnectedness, organizational representation in complexity analysis is just as essential. This thesis addresses this organizational aspect of complexity through an Organizational Complexity Metric (OCM) to aid complexity management. The OCM augments Sinha’s structural complexity metric for product architectures into a metric that can be applied to organizations. Utilizing nested numerical design structure matrices (DSMs), a compact visual representation of organizational complexity was developed. Within the nested numerical DSM are existing organizational datasets used …

Demonstration Of Three True Random Number Generator Circuits Using Memristor Created Entropy And Commercial Off-The-Shelf Components, Scott Stoller, Kristy A. Campbell

Electrical and Computer Engineering Faculty Publications and Presentations

In this work, we build and test three memristor-based true random number generator (TRNG) circuits: two previously presented in the literature and one which is our own design. The functionality of each circuit is assessed using the National Institute of Standards and Technology (NIST) Statistical Test Suite (STS). The TRNG circuits were built using commercially available off-the-shelf parts, including the memristor. The results of this work confirm the usefulness of memristors for successful implementation of TRNG circuits, as well as the ease with which a TRNG can be built using simple circuit designs and off-the-shelf breadboard circuit components.

Hazard Mapping For Infrastructure Planning In The Arctic, Christopher I. Amaddio

Theses and Dissertations

Using modern high-resolution aerial photographs, LiDAR, historical aerial photographs, and facility data, a hazard mapping effort identified risks to infrastructure at Thule Air Base, Greenland, based on visible terrain features, surface hydrology, and slope; the distribution of these risks were then compared to existing foundation damage. The analysis indicated abundant and widespread geotechnical hazards at Thule Air Base and a weak relationship to existing foundation damage that requires more research to understand. The resulting hazard maps provide a critical tool for risk assessment and planning as well as a model for other locations to follow.

Evaluating The Impact Of Culture On Customer Satisfaction For Fms Projects, Yaquari A. Adams Ii

Theses and Dissertations

The cost, time, and quality pillars of the iron triangle in project management are often considered the most important factors for managers to consider when striving to achieve project success. However, recent literature suggests customer satisfaction and end-user benefit are the most important elements to prioritize during project development. This research analyzes the Air Force Security Assistance Center Construction Division and Foreign Military Sales (FMS) joint construction operations in relation to two Project Management Body of Knowledge (PMBOK) knowledge areas, project stakeholder management and project risk management. Project stakeholder management is addressed by identifying the relationship between cultural competency and …

Re-Aerosolization Of Dense Metal Oxide Simulating Radiological Contamination From Military Clothing, Joseph M. Chapman

Theses and Dissertations

Radiological contamination from nuclear accidents or the terrorist use of a Radiological Dispersal Device (RDD) are events that first responders must be prepared for. It is currently assumed that removal of the victims clothing will remove 80-90 of contamination. Many RDD radioisotopes produce dense aerosols that would then contaminate victim clothing and re-aerosolize during clothing removal. A series of experiments were conducted during which clothing was contaminated with a dense aerosol simulating the radioisotope of Strontium 90. Compared to background, there was statistically significant re-aerosolization from the clothing. This demonstrates inhalation hazards from re-aerosolization of RDD contamination.

An Analysis Of Various Hydrogen Production Methods For Fleet Vehicle Fuel, Eugene J. Denezza Ii

Theses and Dissertations

As conflict, the environment, and politics cause changes around the world, the United States Air Force is pursuing a diversification of drop-in and alternative fuel sources. Hydrogen fuel cells for vehicles are gaining popularity worldwide. Yet, how to best produce hydrogen gas still remains a question. This thesis will provide an overview of various hydrogen production methods and their respective environmental impacts, costs, efficiencies, and viability; and will perform sensitivity analysis to determine an optimal solution. The optimal production method is Thermolysis followed by Steam Reformation of Landfill or Natural Gas, Coal Gasification, and PEM Electrolysis. Based on varying requirements …

Utilizing Model Based Systems Engineering To Identify Safety Critical Functions In Airworthiness Certification, Jeffrey C. King

Theses and Dissertations

Modern aircraft are complex systems with numerous interacting hardware and software components. To minimize any safety mishaps during operations, new aircraft designs and modifications must go through an airworthiness certification. The current United States Air Force (USAF) airworthiness certification process, captured in MIL-HDBK-516C, is time-consuming and manpower intensive due to extensive documentation. To minimize inefficiencies of this document-based approach, this thesis examined model-based systems engineering (MBSE) to support Safety Critical Function (SCF) thread analysis against criteria found in Section 15 of MIL-HDBK-516C. Within this scope, the research identified an SCF domain-specific profile and style guide using the Systems Modeling Language …

A Reference Architecture For Rapid Cubesat Development, Sean R. Kelly

Theses and Dissertations

The CubeSat class of nanosatellites has lowered the barrier of entry to space and has rapidly gained popularity in recent years. To successfully design a CubeSat system in a rapid cycle conducive to academic timelines, a Reference Architecture geared towards University CubeSat development would be helpful. A Reference Architecture would speed up the development process by providing a template, capturing previous work and lessons learned from subject matter experts, providing a framework to focus on the CubeSats design rather than the fine details of modeling software. A Reference Architecture can also add functionality that student teams could use and improve …

A State-Based Model For Validating Autonomous Munition Behaviors, Dalton J. Miller

Theses and Dissertations

Autonomous munitions provide an opportunity for the Department of Defense (DoD) to extend the capabilities of operators in combat situations. However, there is also a need for a high level of trust in the effectiveness and accuracy of these systems. With the advent of model-based standards in autonomy and munitions, there is a need to implement these techniques toward an effective modeling and simulation (MS) capability. By leveraging modern MS tools such as Cameo Systems Modeler and the DoD's Advanced Framework for Simulation, Integration, and Modeling (AFSIM), this thesis proposes a framework for simulating complex autonomy architectures within high fidelity …