Engineering Commons^™

Free-Standing, Thin-Film Sensors For The Trace Detection Of Explosives, Peter P. Ricci, Otto J. Gregory

Chemical, Biomolecular, and Materials Engineering Faculty Publications

In a world focused on the development of cybersecurity, many densely populated areas and transportation hubs are still susceptible to terrorist attacks via improvised explosive devices (IEDs). These devices frequently employ a combination of peroxide based explosives as well as nitramines, nitrates, and nitroaromatics. Detection of these explosives can be challenging due to varying chemical composition and the extremely low vapor pressures exhibited by some explosive compounds. No electronic trace detection system currently exists that is capable of continuously monitoring both peroxide based explosives and certain nitrogen based explosives, or their precursors, in the vapor phase. Recently, we developed a …

Zinc Gallate Spinel Dielectric Function, Band-To-Band Transitions, And Γ-Point Effective Mass Parameters, Matthew J. Hilfiker, Megan Stokey, Rafal Korlacki, Ufuk Kilic, Zbigniew Galazka, Klaus Irmscher, Stefan Zollner, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

We determine the dielectric function of the emerging ultrawide bandgap semiconductor ZnGa₂O₄ from the near-infrared (0.75 eV) into the vacuum ultraviolet (8.5 eV) spectral regions using spectroscopic ellipsometry on high quality single crystal substrates. We perform density functional theory calculations and discuss the band structure and the Brillouin zone Γ-point band-to-band transition energies, their transition matrix elements, and effective band mass parameters. We find an isotropic effective mass parameter (0.24m_e) at the bottom of the Γ-point conduction band, which equals the lowest valence band effective mass parameter at the top of the highly anisotropic …

Quantitative Evaluation Of Asphalt Binder Extraction From Hot Mix Asphalt Pavement Using Ashing And Centrifuge Methods, Ahmed Hemida, Magdy Abdelrahman, Eslam Deef-Allah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder requires more investigation to be accurately and precisely extracted since it is an effective procedure for quality assurance quality control (QA/QC) and subsequent binder characterization. In this research, the authors presented a hands-on experience with binder extraction to deliver recommendations concerning the sensitive steps that may affect the outcomes (extracted binder content, P_be%). Two mineral matter determination methods (ashing and centrifuge) were addressed based on the centrifuge extraction method. Field cores were investigated by comparing the P_be% to the actual binder content, P_ba%. Analysis of variance (ANOVA) and Tukey Post-Hoc statistical analyses, …

Kontrollimi I Cilësisë Ne Vendin E Ndertimit-Punishte Gjatë Zbatimit Të Strukturave Betonarme, Florim H. Bytyqi

Theses and Dissertations

Në këtë temë do të flasim për Cilësin e betonit dhe vetitë e betonit të njomë dhe të ngurtësuar, në veçanti për betonin, komponentët e betonit, përparësitë dhe mangësit, vetitë e tij, si dhe për llojet e betonit, poashtu edhe për rezistencën në shtypje. Duke ditur që betoni është njëri ndër materialet më të përdorura në ndërtimin e strukturave, të cilat përditë e më tepër po bëhen objekt i arritjeve shkencore në inxhinierinë e ndërtimit si në aspektin e lartësisë (etazhitetit), e po ashtu edhe aplikimin e betoneve “të reja” speciale. Fabrikave per prodhimie betonit si dhe mjetet e transportit …

Auditimi I Elementeve Të Sigurisë Rrugore Në Autostradën “Arbën Xhaferi”, Lekë Krasniqi

Theses and Dissertations

Ky hulumtim ka të bëjë me auditimin e sigurisë së elementeve të rrugës pas përfundimit të punimeve ndërtimore të Autostradës “Arbën Xhaferi”, ndërtimi i së cilës ka nisur në vitin 2015, me gjatësi 65km nga kryeqyteti i Republikës së Kosovës - Prishtina në drejtim të kryeqytetit të Maqedonisë Veriore - Shkupit, inaugurimi i së cilës është bërë në muajin maj të vitit 2019.

Teza e masterit përshkruan konceptin e Auditimit të elementeve të sigurisë rrugore në autostradën “Arbën Xhaferi” i cili është bërë para se të bëhet hapja, në mënyrë që të bëhet auditimi i të gjitha elementeve të sigurisë …

Materialet Ndërtimore Ndikimi I Lagështisë Së Drurit Në Vetitë Fiziko-Mekanike, Armend Konjush

Theses and Dissertations

Punimi i realizuar bazohet në lëndën: Konstruksionet e Drurit. Kjo përmbledhje ofron një pamje të përditësuar të njohurive aktuale në lidhje me Drurin si material ndërtimorë, mekanizmat e hidratimit, përfshirë origjinën e periudhës së reaksionit të ngadaltë në vetitë fiziko mekanike, natyra e periudhës së nxitimit, roli i vetive fiziko mekanike në Drurin si meterial ndertimi po ashtu edhe tharja e cila konsiderohet nje nder proceset kryesore.

Qëllimi i kësaj teme është të bëj hulumtim rreth procesit të Drurit duke ju nenshtruar vetive fiziko-mekanike . Shtjellimin dhe ndarjen e llojeve të ndryshme të Drunjëve.

Po ashtu do te shtjellohen analiza …

Half-Barrel Planter Mover, Mihir Shah, Natalie Lewis, Mason James Hughes

Mechanical Engineering

A device for transporting heavy barrel planters is needed. Barrel planters are wooden wine barrels that have been cut in half along the circumference. They are used to store and grow a variety of plants. As such, they can contain more than 300 pounds of soil. The products currently on the market are not designed for such heavy planters, are cost prohibitive, and do not take advantage of the tapered design of a wine barrel half. A solution is needed that is durable, easy to use, and low cost. This final design report will show the steps used to find …

Fsae Chassis Hardpoint Optimization, Christopher Soohoo, Ethan Vallivero, Dwarak Reddy

Mechanical Engineering

Our team has been tasked with optimizing hardpoints for the Cal Poly Racing team. Hardpoints are the locations on the chassis of a car that are designed to carry both internal and external loads, they are the areas where the engine and suspension connect to the chassis. These points are subject to torsion, shear, bending and pull-out loads. Cal Poly Racing needs more thoroughly analyzed individualized hardpoints that are optimized for weight, strength and specific stiffness, so they can reduce the overall weight and improve the race times of the vehicle while maintaining their strength and stiffness standards. Our team …

Impact Of Multiple Waves Of Covid-19 On Healthcare Networks In The United States, Emad M. Hassan, Hussam N. Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The risk of overwhelming hospitals from multiple waves of COVID-19 is yet to be quantified. Here, we investigate the impact of different scenarios of releasing strong measures implemented around the U.S. on COVID-19 hospitalized cases and the risk of overwhelming the hospitals while considering resources at the county level. We show that multiple waves might cause an unprecedented impact on the hospitals if an increasing number of the population becomes susceptible and/or if the various protective measures are discontinued. Furthermore, we explore the ability of different mitigation strategies in providing considerable relief to hospitals. The results can help planners, policymakers, …

Particle-In-Cell Simulation Of An Industrial Magnetron With Electron Population Analysis, Andong Yue, Marcus Pearlman, Mike Worthington, John Cipolla, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Results from a particle-in-cell simulation study of L3Harris CWM-75 kW are presented; the continuous wave cooker magnetron typically operates at 18 kV, 5 A, 1900 G, 896–929 MHz. The startup process of the device has been simulated in 3D by using the PIC code VSim. The startup behavior was examined with (1) no priming, (2) RF priming, and (3) cathode modulation. Under no priming, the simulated device failed to oscillate in a simulation time of 1000 ns. Oscillations were achieved with both RF priming (150 ns) and cathode modulation (180 ns). Half (∼40 kW) of the device’s typical operating power …

Volcanic Emissions And Atmospheric Pollution: A Study Of Nanoparticles, Erika M. Trejos, Luis F. O. Silva, James C. Hower, Eriko M. M. Flores, Carlos Mario González, Jorge E. Pachón, Beatriz H. Aristizábal

Center for Applied Energy Research Faculty and Staff Publications

The influence of emissions of an active volcano on the composition of nanoparticles and ultrafine road dust was identified in an urban area of the Andes. Although many cities are close to active volcanoes, few studies have evaluated their influence in road dust composition. Air quality in urban areas is significantly affected by non-exhaust emissions (e.g. road dust, brake wear, tire wear), however, natural sources such as volcanoes also impact the chemical composition of the particles. In this study, elements from volcanic emissions such as Si > Al > Fe > Ca > K > Mg, and Si—Al with K were identified as complex hydrates. …

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) …

Conventional Immunomarkers Stain A Fraction Of Astrocytes In Vitro: A Comparison Of Rat Cortical And Spinal Cord Astrocytes In Naïve And Stimulated Cultures, Bailey Balouch, Jessica L. Funnell, Alexis M. Ziemba, Devan L. Puhl, Kathy Lin, Manoj K. Gottipati, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Astrocytes are responsible for a wide variety of essential functions throughout the central nervous system. The protein markers glial fibrillary acidic protein (GFAP), glutamate aspartate transporter (GLAST), glutamate transporter-1 (GLT-1), glutamine synthetase (GS), 10-formyltetrahydrofolate dehydrogenase (ALDH1L1), and the transcription factor SOX9 are routinely used to label astrocytes in primary rodent cultures. However, GLAST, GLT-1, GS, and SOX9 are also produced by microglia and oligodendrocytes and GFAP, GLAST, GLT-1, and GS production levels are affected by astrocyte phenotypic changes associated with reactive astrogliosis. No group has performed a comprehensive immunocytochemical evaluation to quantify the percentage of cells labeled by these markers …

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 …

Color-Compressive Bilateral Filter And Nonlocal Means For High-Dimensional Images, Christina Karam, Kenjiro Sugimoto, Keigo Hirakawa

Electrical and Computer Engineering Faculty Publications

We propose accelerated implementations of bilateral filter (BF) and nonlocal means (NLM) called color-compressive bilateral filter (CCBF) and color-compressive nonlocal means (CCNLM). CCBF and CCNLM are random filters, whose Monte-Carlo averaged output images are identical to the output images of conventional BF and NLM, respectively. However, CCBF and CCNLM are considerably faster because the spatial processing of multiple color channels are combined into a single random filtering process. This implies that the complexity of CCBF and CCNLM is less sensitive to color dimension (e.g., hyperspectral images) relatively to other BF and NLM methods. We experimentally verified that the execution time …

Deep Learning For Anisoplanatic Optical Turbulence Mitigation In Long-Range Imaging, Matthew A. Hoffmire, Russell C. Hardie, Michael A. Rucci, Richard Van Hook, Barry K. Karch

Electrical and Computer Engineering Faculty Publications

We present a deep learning approach for restoring images degraded by atmospheric optical turbulence. We consider the case of terrestrial imaging over long ranges with a wide field-of-view. This produces an anisoplanatic imaging scenario where turbulence warping and blurring vary spatially across the image. The proposed turbulence mitigation (TM) method assumes that a sequence of short-exposure images is acquired. A block matching (BM) registration algorithm is applied to the observed frames for dewarping, and the resulting images are averaged. A convolutional neural network (CNN) is then employed to perform spatially adaptive restoration. We refer to the proposed TM algorithm as …

Controller Modeling And Stability Analysis Of Multiple Input Single Output Dc-Dc Converter, Astha Adhikari

Master's Theses

This thesis entails the stability analysis of the Multiple Input Single Output (MISO) DC-DC converter developed for the DC House Project at Cal Poly. A frequency domain control system model of the MISO converter was designed and constructed using MATLAB Simulink. Transfer functions were derived and modeled for each stage of the converter to best fit the converter circuit system used in the original MISO circuit. Stability metrics such as overshoot, undershoot, rise time, phase margin and gain margin were measured to evaluate and analyze the stability of the converter. These metrics were measured with the original model including the …

Comparing Radiation Shielding Potential Of Liquid Propellants To Water For Application In Space, John Czaplewski

Master's Theses

The radiation environment in space is a threat that engineers and astronauts need to mitigate as exploration into the solar system expands. Passive shielding involves placing as much material between critical components and the radiation environment as possible. However, with mass and size budgets, it is important to select efficient materials to provide shielding. Currently, NASA and other space agencies plan on using water as a shield against radiation since it is already necessary for human missions. Water has been tested thoroughly and has been proven to be effective. Liquid propellants are needed for every mission and also share similar …

Common Pool Resource Management: Assessing Water Resources Planning For Hydrologically Connected Surface And Groundwater Systems, Francisco Munoz-Arriola, Tarik Abdel-Monem, A. Amaranto

Department of Mechanical and Materials Engineering: Faculty Publications

Common pool resource (CPR) management has the potential to overcome the collective action dilemma, defined as the tendency for individual users to exploit natural resources and contribute to a tragedy of the commons. Design principles associated with effective CPR management help to ensure that arrangements work to the mutual benefit of water users. This study contributes to current research on CPR management by examining the process of implementing integrated management planning through the lens of CPR design principles. Integrated management plans facilitate the management of a complex common pool resource, ground and surface water resources having a hydrological connection. Water …

Part-Scale Thermal Simulation Of Laser Powder Bed Fusion Using Graph Theory: Effect Of Thermal History On Porosity, Microstructure Evolution, And Recoater Crash, Reza Yavari, Ziyad Smoqi, Alex Riensche, Ben Bevans, Humaun Kobir, Heimdall Mendoza, Hyeyun Song, Kevin Cole, Prahalada Rao

Department of Mechanical and Materials Engineering: Faculty Publications

Flaw formation in laser powder bed fusion (LPBF) is influenced by the spatiotemporal temperature distribution – thermal history – of the part during the process. Therefore, to prevent flaw formation there is a need for fast and accurate models that can predict the thermal history as a function of the part shape and processing parameters. In previous work, a thermal modeling approach based on graph theory was used to predict the thermal history in LPBF parts in less-than 20% of the time required by finite element-based models with error within 10% of experimental measurements. The present work transitions toward the …

Data-Driven Cfd Scaling Of Bioinspired Mars Flight Vehicles For Hover, Jeremy A. Pohly, Chang-Kwon Kang, Brian D. Landrum, James E. Bluman, Hikaru Aono

PRC-Affiliated Research

One way to improve our model of Mars is through aerial sampling and surveillance, which could provide information to augment the observations made by ground-based exploration and satellite imagery. Flight in the challenging ultra-low-density Martian environment can be achieved with properly scaled bioinspired flapping wing vehicle configurations that utilize the same high lift producing mechanisms that are employed by insects on Earth. Through dynamic scaling of wings and kinematics, we investigate the ability to generate solutions for a broad range of flapping wing flight vehicles with masses ranging from insects O(10−3) kg to the Mars helicopter Ingenuity O(100) kg. A …

Data-Driven Cfd Scaling Of Bioinspired Mars Flight Vehicles For Hover, Jeremy A. Pohly, Chang-Kwon Kang, Brian D. Landrum, James E. Bluman, Hikaru Aono

PRC-Affiliated Research

One way to improve our model of Mars is through aerial sampling and surveillance, which could provide information to augment the observations made by ground-based exploration and satellite imagery. Flight in the challenging ultra-low-density Martian environment can be achieved with properly scaled bioinspired flapping wing vehicle configurations that utilize the same high lift producing mechanisms that are employed by insects on Earth. Through dynamic scaling of wings and kinematics, we investigate the ability to generate solutions for a broad range of flapping wing flight vehicles with masses ranging from insects O(10−3) kg to the Mars helicopter Ingenuity O(100) kg. A …

Meta-Heuristic Optimization Methods For Quaternion-Valued Neural Networks, Jeremiah P. Bill

Theses and Dissertations

In recent years, real-valued neural networks have demonstrated promising, and often striking, results across a broad range of domains. This has driven a surge of applications utilizing high-dimensional datasets. While many techniques exist to alleviate issues of high-dimensionality, they all induce a cost in terms of network size or computational runtime. This work examines the use of quaternions, a form of hypercomplex numbers, in neural networks. The constructed networks demonstrate the ability of quaternions to encode high-dimensional data in an efficient neural network structure, showing that hypercomplex neural networks reduce the number of total trainable parameters compared to their real-valued …

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 …

Exploring The Limits Of Strategic Thought: Evaluating How Different Communication Modalities Affect The Nature Of Strategic Decision-Making Using Cognitive Hierarchy, Stephen D. Donnel

Theses and Dissertations

This research examines and quantifies the degree to which both information communication modality and the situational complexity affect individuals' ability to process the provided information and determine an effective strategy. Human subject testing herein consists of benign benevolent intervention involving the presentation of a series of strategic situations. For each situation, a participant attempts to identify their best response for a two-player, normal-form game with complete information. In each such game, players seek to maximize their own utility while considering their own actions, their opponent's actions, and each player's respective preferences over outcomes resulting from the possible combinations of actions. …

Air Combat Maneuvering Via Operations Research And Artificial Intelligence Methods, James B. Crumpacker

Theses and Dissertations

Within visual range air combat requires rapid, sequential decision-making to survive and defeat the adversary. Fighter pilots spend years perfecting maneuvers for these types of engagements, yet the emergence of unmanned, autonomous vehicle technologies elicits a natural question - can an autonomous unmanned combat aerial vehicle (AUCAV) be imbued with the necessary artificial intelligence to perform air combat maneuvering tasks independently? We formulate and solve the air combat maneuvering problem to examine this question, developing a Markov decision process model to control an AUCAV seeking to destroy a maneuvering adversarial vehicle. An approximate dynamic programming (ADP) approach implementing neural network …

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.

The Autonomous Attack Aviation Problem, John C. Goodwill

Theses and Dissertations

An autonomous unmanned combat aerial vehicle (AUCAV) performing an air-to-ground attack mission must make sequential targeting and routing decisions under uncertainty. We formulate a Markov decision process model of this autonomous attack aviation problem (A3P) and solve it using an approximate dynamic programming (ADP) approach. We develop an approximate policy iteration algorithm that implements a least squares temporal difference learning mechanism to solve the A3P. Basis functions are developed and tested for application within the ADP algorithm. The ADP policy is compared to a benchmark policy, the DROP policy, which is determined by repeatedly solving a deterministic orienteering problem as …

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 …

Bayesian Augmentation Of Cnn-Lstm For Video Classification With Uncertainty Measures, Emmie K. Swize

Theses and Dissertations

The success of Department of Defense (DoD) missions rely heavily on intelligence, surveillance, and reconnaissance (ISR) capabilities, which supply information about the activities and resources of an enemy or adversary. To secure this information, satellites and unmanned aircraft systems collect video data to be classified by either humans or machine learning networks. Traditional automated video classification methods lack measures of uncertainty, meaning the network is unable to identify those cases in which it predictions are made with significant uncertainty. This leads to misclassification, as the traditional network classifies each observation with same amount of certainty, no matter what the observation …