Engineering Commons^™

Durability Assessment And Service Life Prediction Of Concrete In Extreme Aggressive Environment, Mohamed Ismail

Doctoral Dissertations and Master's Theses

The objective of this research is to enhance the durability of newly constructed structural elements by assessing the performance of various concrete mixes for chloride resistance. The study focuses on establishing and developing correlations between chloride diffusion rates and concrete resistivity. By identifying these correlations and based on the target service life, the research aims to set appropriate thresholds for Surface Resistivity (SR) and Bulk Resistivity (BR) tests, which will be used to qualify concrete mixes used in in extremely aggressive chloride environments. To achieve these objectives, the research uses a systematic approach that combines experimental testing with analytical modeling. …

Dynamic Estimation Of Large-Scale Flow Events In Open Cavity Flows, Alexandre Mota

Doctoral Dissertations and Master's Theses

Flow over an open cavity has a dynamically complex flowfield, generating pressure fluctuations that can amplify shear stress and cause structural damage to the stores within it and the aircraft as a whole. These pressure loads are linked to large-scale resonant shear layer phenomena. Consequently, it is crucial to establish this link by characterizing the large-scale flow events conditional upon pressure measurements to improve the prediction and control of the detrimental pressure fluctuations. In this study, a link between the pressure measurements (to control) and large-scale shear layer events (to actuate) will be established using a combination of two data-driven …

Carboxymethyl Cellulose-Based Preformed Particle Gels For Water Management In Oil And Gas Reservoirs, Ahmed Ben Ali, Ahmed Hamza, Abdulaziz A. Almakimi, Mohammed Saad, Ibnelwaleed A. Hussein, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Carboxymethyl cellulose (CMC) based materials have been proposed as preformed particle gels (PPGs) for reducing excessive water production in oil and gas reservoirs. Multi-sized dry particles ranging between 100 and 1180 μm have been synthesized using microwave-assisted grafting copolymerization of CMC and acrylamide (AM)/n,n''-methylene-bisacrylamide (MBA). FTIR and SEM confirmed CMC crosslinked polyacrylamide's chemical structure and morphology (CMC/CPAM). Thermo-gravimetric analysis has demonstrated the thermal stability of dry PPGs up to 309 °C. CMC/CPAM showed slightly high absorbency in brine 2 (TDS = 67.3 g/L) compared to brine 1 (TDS = 33.65 g/L), 1% NaCl, and deionized water, with swelling ratios (SR) …

Gratings In Optical Waveguides And Lasers, Weida Zhang

Electrical Engineering Theses and Dissertations

Gratings play a crucial role in Distributed Bragg reflector (DBR) lasers, influencing their performance and characteristics. The focus of this work is aimed at the design of DBR lasers that significantly impact the laser's spectral and temporal behavior, making it a key component in optimizing DBR laser functionality.

The SMU developed grating software, compared with commercially available photonics software, has improved accuracy and much smaller computation times. The improved accuracy and reduced computation times compared with commercial photonics software occur because commercial software is typically based on numerical methods such as finite-difference time-domain (FDTD), eigenmode expansion and beam propagation methods …

Inexact Methods For Large-Scale Stochastic Programming, Niloofar Fadavi

Operations Research and Engineering Management Theses and Dissertations

This dissertation addresses the development of inexact methods for solving large-scale stochastic programming problems, with a focus on two-stage and multistage settings. Stochastic programming is a robust approach for managing uncertainty in decision-making, with applications across various domains like supply chain management, power systems, and logistics. However, solving large-scale stochastic programming problems, especially those with a nonlinear structure, is computationally challenging due to the high-dimensional nature of uncertainties and the need for efficient optimization techniques.

This work introduces novel inexact proximal bundle algorithms designed to solve two-stage stochastic quadratic programming problems. The proposed methods utilize dual-based and partition-based approaches to …

Feasibility Of Creating A Non-Profit And Nongovernmental Organization Cybersecurity Incident Dataset Repository Using Osint, Stanley Mierzwa, Iassen Christov

Center for Cybersecurity

Organizations of all types are prone to cybersecurity and information security attacks. Non-Profit Organizations (NPOs) and Non-Governmental Organizations (NGOs) are not exempt from using information technology solutions and, thus, have been the recipient victims of cyber attackers. There exist many areas and venues where data are collected to report back annually on the status and numbers of cybersecurity attacks against many sectors of our society. The Department of Homeland Security (DHS) Cybersecurity and Infrastructure Security Agency (CISA) catalogs sixteen critical sectors that are considered vital to the United States. However, finding where the NPO and NGO community should reside with …

Utilizing A Virtual Firewall Appliance For Introducing And Reinforcing The Concepts And Implementation Of Devices To Improve Security In A Computing Environment, Stanley Mierzwa, Christopher Eng

Center for Cybersecurity

The educational realm of higher education cybersecurity curriculum continues to evolve to provide more opportunities for experiential hands-on and work role-related practical applications of technology solutions. Gaining more excellent competencies is quickly becoming a standard requirement for programs with the National Security Agency Center of Academic Excellence designation. The work roles of cybersecurity include a variety of knowledge, skills, and abilities, depending on the activity category or task. Firewalls have been a staple cybersecurity, network security, and information security device and strategy to protect organization networks and computing environments. This paper will provide details and a description of the effort …

Integrating Digital Twin Technology For Real Time Blockage Detection In Water Cooled Electronics, Richard Scott Hainey Jr.

Theses and Dissertations

This paper presents a culmination of research into integrating Digital Twin (DT) technology in water-cooled electronic systems to improve system reliability by detecting faults in the cooling system that maintains the proper operation of heat-producing electronic components and systems. A DT is a virtual representation of a physical twin (PT). This PT can represent real-world systems, individual components, or processes. Using the DT, operators can gain insight into the behavior and characteristics of the PT, thereby facilitating informed decisions to improve its health and optimize processes. The DT system is designed to detect obstructions forming in the waste heat-producing components …

Investigation And Comparative Analysis Of Onset Of Nucleate Boiling (Onb) In A Narrow Rectangular Channel In Microgravity And Earth Gravity Environments, Fahim Foysal

Theses and Dissertations

Understanding the onset of nucleate boiling (ONB) in different gravitational environments is crucial for a wide variety of industrial and space applications of flow boiling systems for thermal management. This thesis provides a comparative analysis of ONB in both microgravity (µg) and Earth gravity (1g) environments, with the aim of identifying the key differences. NASA’s experimental facility called Flow Boiling and Condensation Experiment (FBCE) equipped with Flow Boiling Module (FBM) was used for both the experiment onboard the International Space Station (ISS) and on Earth. The experiment was conducted in a rectangular channel of 5mm (depth) ×2.5 mm (width) ×114.6 …

The Hydraulically Smooth Limit Of Flow Over Surfaces With Spanwise Heterogeneity, Haosen Xu, George Ilhwan Park, Xiang Yang, Xiaowei Zhu

Mechanical and Materials Engineering Faculty Publications and Presentations

Wall slip is conventionally obtained through riblets or grooves. As riblets are macroscopic objects, it is usually not practical to discuss slip patterns at the hydraulically smooth limit. Per Nikuradse, the smooth limit is when the characteristic length of the surface pattern is comparable to the viscous length scale. Recent studies show the possibility of slip at the microscopic scale, making slip patterns at the hydraulically smooth limit relevant. In this study, we leverage a high-fidelity pseudo-spectral code and study flow over surfaces featuring alternating strips of slip and no-slip wall conditions. The wavelength of the surface pattern, denoted as …

A Review On Photoacoustic Spectroscopy Techniques For Gas Sensing, Dakshith Ruvin Wijesinghe, Md Abu Zobair, Mina Esmaeelpour

Electrical and Computer Engineering Faculty Research & Creative Works

The rapid growth of industry and the global drive for modernization have led to an increase in gas emissions, which present significant environmental and health risks. As a result, there is a growing need for precise and sensitive gas-monitoring technologies. This review delves into the progress made regarding photoacoustic gas sensors, with a specific focus on the vital components of acoustic cells and acoustic detectors. This review highlights photoacoustic spectroscopy (PAS) as an optical detection technique, lauding its high sensitivity, selectivity, and capability to detect a wide range of gaseous species. The principles of photoacoustic gas sensors are outlined, emphasizing …

Mannosylated Pamam G2 Dendrimers Mediated Rate Programmed Delivery Of Efavirenz Target Hiv Viral Latency At Reservoirs, Rohini Kharwad, Mohsin Kazi, Nilesh Mahajan, Payal Badole, Sachin More, Asaad Kayali, Md Noushad Javed, Mohammed Kaleem

Mechanical Engineering Faculty Publications

In this current research, we conceptualized a novel nanotechnology-enabled synthesis approach of targeting HIV-harboring tissues via second-generation (G2) polyamidoamine (PAMAM) mannosylated (MPG2) dendrimers for programmed delivery of anti-HIV drugs efavirenz (EFV) and ritonavir (RTV). Briefly, here mannose served purpose of ligand in this EFV and RTV-loaded PAMAM G2 dendrimers, synthesized by divergent techniques, denoted as MPG2ER. The developed nanocarriers were characterized by different analytical tools FTIR, NMR, zeta potential, particle size, and surface morphology. The results of confocal microscopy showed substantial alterations in the morphology of H9 cells, favored by relatively higher drug uptake through the MPG2ER. Interestingly, the drug …

Rail Anchor Slip Force Testing, S. Mustapha Rahmaninezhad, Constantine Tarawneh, Arturo A. Fuentes, David Vera, Jorge Encinia

Civil Engineering Faculty Publications

Continuous welded rail (CWR) is increasingly adopted to replace jointed track due to its superior ride quality, extended fatigue life, and reduced maintenance costs. However, the absence of joints introduces challenges, such as thermal expansion-related track buckling. Maintaining the Rail Neutral Temperature (RNT) is essential for managing rail stresses and preventing these failures. Rail anchors are employed to distribute loads from rails to ties. The rail anchors enhance longitudinal track resistance by minimizing the rail’s longitudinal movement. These anchors are crucial for managing the RNT, ultimately contributing to the prevention of rail buckling and the reinforcement of the track structure. …

10.01.2024 Orsp Connect, Liz Williamson

ORED Newsletter

NIH Podcast on simplified review framework

LINC lunch External Review

NIDA Diversity Supplements Webinar

Feasibility Study Of Perovskite Solid Electrolyte For Electrochemical Lithium-Ion Cells, Danyi Sun

Theses and Dissertations

To achieve a high energy density in lithium-ion batteries (LIB), replacing the graphite anode with lithium metal is essential, as it offers a theoretical capacity of 3840 mAh/g.(Q. Wang et al. 2021) However, the use of lithium metal anodes is restricted by the formation of lithium dendrites, which can cause short circuits.(Wood et al. 2016) Solid-state electrolytes present a viable alternative to conventional liquid electrolytes by potentially mitigating dendrite growth. Among these, the perovskite-type Li3/8Sr7/16Ta3/4Zr1/4O3 (LSTH) stands out due to its excellent ambient stability, although its synthesis, properties, and applications remain underexplored.(Y. Li et al. 2018) In this study, I …

Investigating Electrochemical Performance And Interfacial Stability Of Solid-State Lithium Metal Batteries: A Study Of Hybrid Polymer-Ceramic Electrolyte Systems, Ziba Rahmati

Theses and Dissertations

Solid-state batteries (SSBs) are emerging as a promising energy storage technology, surpassing traditional liquid electrolyte (LE) counterparts in performance and safety. A critical component in SSBs is the solid-state electrolyte (SSE), which plays a pivotal role in safety, efficiency and stability. SSEs, including sulfides, halides, oxides, and polymers, present distinct advantages and challenges compared to LEs. Among these, oxide-based SSEs are particularly attractive for their balance in ionic conductivity and chemical stability.

This study addresses key challenges related to interfacial stability and electrochemical performance in SSBs by focusing on hybrid polymer-ceramic electrolyte systems. A major challenge to such a SSB …

Vascular Calcification In A Mouse Model Of Chronic Kidney Disease And In Human Peripheral Arterial Disease, Breanna Pederson

Theses and Dissertations

Vascular calcification is a process in which calcium and phosphate crystallize to form hydroxyapatite in the extracellular matrix of blood vessels. There are two forms of arterial calcification: intimal and medial, which occur via different etiologies. Intimal calcification is associated with atherosclerosis and occurs in the layer of endothelial cells adjacent to the artery lumen. Medial arterial calcification (MAC) is independent of atherosclerosis and occurs in the middle, muscular layer of the artery. MAC is strongly associated with aging, diabetes mellitus, and chronic kidney disease (CKD). MAC is frequently in patients with peripheral arterial disease (PAD). Most studies to date …

Optimal Design And Comparison Of Synchronous Machines With Inner And Outer Reluctance Rotors And Pm Or Dc Stator Combined Excitation, Oluwaseun A. Badewa, Ali Mohammadi, Donovin D. Lewis, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents an optimal design and comparative analysis for a toroidally wound reluctance rotor synchronous machine with either PM or DC excitation in the stator. The prototype of the PM version is experimentally evaluated, and its results are used to validate the model of the DC version as they share the same topology. The stator DC-excited synchronous (SDCES) motor is optimized at different outer diameters using large-scale multi-objective differential evolution (DE) and comparatively analyzed at power ratings typical for electric traction and propulsion applications. Its performance at reduced temperatures shows increased efficiency and goodness due to reduced losses, and …

Two-Level Design Optimization Of Ac Machines With Dc Stator Excitation And Minimal Torque Ripple Using Reluctance Rotor Profile Shaping, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Torque ripple mitigation in electric machines is important for a smooth and stable operation, minimize mechanical vibrations, and enhance the overall performance. In this paper, a novel two-level optimization method is proposed for the design of synchronous flux-switching and hybrid excitation machines with an innovative multi-point spline shaping method to minimize the torque ripple. This study uses models that are validated by experimental tests from a prototype with similar topology, and exemplifies the aforementioned optimization process on a 28 pole machine. The analysis results indicate that the torque ripple can be substantially reduced with improved electromagnetic torque of the electric …

Design Of High-Power Polyphase Pcb Coil Systems For Wireless Power Transfer, Donovin D. Lewis, Lucas Gastineau, Omer Onar, Malcolm Mcculloch, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Printed circuit board (PCB) coils have been pro- posed prior for implementation as inductive wireless charging coils to minimize size and cost. Utilization of PCBs can allow for a reduced cost, improved manufacturability, and a wide range of geometric customization options. To circumvent material limitations on insulation and thermal performance, parallel paths can be implemented to divide the current per path accordingly. Within this paper, an unconventional high power PCB coil is designed employing all possible techniques for wiring with axial and radial parallel paths with equivalent transposition to minimize circulating currents. Design studies are simulated in 3D finite element …

Analytical And Fe Modeling For The Design Of Coreless Axial Flux Machines With Halbach Array And Surface Pm Rotors, Matin Vatani, Yaser Chulaee, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper introduces a rapid analytical modeling approach for coreless axial flux permanent magnet (AFPM) machines featuring surface-mounted and Halbach PM array rotors. The methodology employs a 2D model at an arbitrary diameter of the machine and converts AFPM machines into an equivalent linear machine. Initially, equations for PM flux density, accounting for harmonic content, are developed for both rotor types. Subsequently, a force equation is derived for the 2D equivalent machine based on the Lorentz force equation and the stator winding factor. In the final step, a torque equation at an arbitrary diameter—specifically, the average diameter in this paper—is …

Multi-Disk Coreless Axial Flux Permanent Magnet Synchronous Motors With Surface Pm And Halbach Array Rotors For Electric Aircraft Propulsion, Matin Vatani, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents multiple single- and multi-disk coreless axial flux permanent magnet (AFPM) motors, focusing on specific power density and reliability for electric aircraft propulsion. Several 3D finite element analysis (FEA) parametric studies were conducted to assess the geometric impacts on a single-disk coreless AFPM motor featuring two separate stators and a double-sided Halbach array rotor configuration. These studies form the foundation for the design of both single and multi-disk machines. Single-disk coreless AFPM motors with rotor back iron embedded between the stators, offering magnetically decoupled stators, are subsequently introduced. The paper concludes by presenting four multi-disk coreless AFPM motor …

Multi-Wound Axial Flux Generators With Halbach Array Rotors, Matin Vatani, Yaser Chulaee, John F. Eastham, Xiaoze Pei, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents three coreless axial flux permanent magnet (AFPM) generator topologies that feature magnetically and electrically decoupled outputs using a single prime mover. The proposed topologies include: (1) two separate generators mounted on the same shaft, (2) a nested configuration with a smaller generator inside a larger one, and (3) a multi-wound generator with two sets of windings and different pole numbers for each rotor side. The multi-wound generator is selected for further investigation due to its superior power-to-volume ratio and the advantage of utilizing a single structure for stator cooling. The airgap magnetic flux density equation is derived …

The Undergraduate Engineering Mental Health Help-Seeking Instrument (Ue-Mh-Hsi): Development And Validity Evidence, Joseph H. Hammer, Courtney J. Wright, Melanie E. Miller, Sarah A. Wilson

Chemical and Materials Engineering Faculty Publications

Background: Undergraduate engineering students experiencing distress are less likely than peers to ask for professional help. A population-specific instrument to facilitate the identification of factors that influence mental healthcare utilization could guide development and testing of interventions to increase help seeking.

Purpose: We used mixed methods guided by the Integrated Behavioral Model (IBM) to develop and evaluate the Undergraduate Engineering Mental Health Help-Seeking Instrument (UE-MH-HSI).

Method: First, we adapted existing measures of mental health help-seeking intention and mechanisms (i.e., attitudes, perceived norm: injunctive, perceived norm: descriptive, personal agency: autonomy, personal agency: capacity). Second, we coded qualitative interviews (N = 33) …

Experimental Comparison Of Open Chamber Spark Plug And Passive Prechamber Spark Igniters On The Combustion Of Fumigated Natural Gas For Heavy Duty Engine Applications, John Richard Valla

Master's Theses (2009 -)

Methane the primary component of natural gas, has 80 times the global warming potential of CO2. As a result methane emissions regulations have rapidly increased in recent years. This posses a challenge for heavy duty spark ignited (SI) natural gas engine OEMs, in efforts to reduce methane and other criteria pollutant emissions such as NOx. Heavy duty natural gas engine OEMs are pushing engine efficiency and reducing emissions by running higher compression ratios and leaner air fuel ratios. This reduces fuel consumption and combustion temperature which decreases NOx emissions, but tends to increase methane emissions. Unfortunately, lean high compression ratio …

California Polytechnic Architecture Graveyard Safety And Locational Signage Project, Luke C. Vanderkooij

Construction Management

Hiking along Poly Canyon Road, towards Cal Poly’s Architecture Graveyard, limited information can be located on the actual trail, with current signage only describing prohibited activities. This project aimed to provide needed safety and locational signage for pedestrians, bikers, and vehicles, clearly outlining maps, safety tips, and emergency contacts. These criteria were led by the desire to proactively limit the risk of traveling along Poly Canyon Road and provide reactive assistance for those in potential danger. These added informational improvements were decided to be included in a bulletin style enclosure with a roof and metal plaque anchored into a reinforced …

Development Of Robust Steel Alloys For Laser-Directed Energy Deposition Via Analysis Of Mechanical Property Sensitivities †, Jonathan Kelley, Joseph W. Newkirk, Laura N. Bartlett, Sriram Praneeth Isanaka, Todd Sparks, Saeid Alipour, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

To ensure consistent performance of additively manufactured metal parts, it is advantageous to identify alloys that are robust to process variations. This paper investigates the effect of steel alloy composition on mechanical property robustness in laser-directed energy deposition (L-DED). In situ blending of ultra-high-strength low-alloy steel (UHSLA) and pure iron powders produced 10 compositions containing 10–100 wt.% UHSLA. Samples were deposited using a novel configuration that enabled rapid collection of hardness data. The Vickers hardness sensitivity of each alloy was evaluated with respect to laser power and interlayer delay time. Yield strength (YS) and ultimate tensile strength (UTS) sensitivities of …

Concrete Design: Underwater Concrete Forms In A Saltwater Environment, Noah Z. Lau

Construction Management

This following project investigated the effects of salt on the concrete curing process. Concrete possesses numerous strengths, making it extremely versatile. This makes it one of the most utilized construction materials. New improved methods are constantly being developed for concrete’s application as a construction material. While concrete is a flexible material with many strengths, it is not without its flaws. Concrete, while strong in compression is weak in tension. It has long cure times and doesn’t generally handle moisture well. This paper evaluates concrete’s change in strength from letting concrete cure in a salt-based underwater environment. To determine the full …

Thermal Management For Optimal Performance Of Unitized Regenerative Fuel Cells, Mythy T. Tran

Mechanical & Aerospace Engineering Theses & Dissertations

As the race to net zero energy intensifies around the world, hydrogen production and fuel cell technologies are attracting more attention, and the technologies are growing rapidly. Together, hydrogen production and fuel cell technologies hold potential for a reliable, green, and sustainable energy system. Hydrogen is an excellent energy carrier and can be produced from various sources, especially green and renewable sources. Fuel cells generate electricity and water from hydrogen and oxygen. In reverse mode, fuel cells operate as electrolyzers to produce hydrogen and oxygen from electricity and water. However, the major drawback that keeps hydrogen and fuel cells from …

Feasibility Study Of Oyster Shell Filtration Media For Stormwater Pollutants Removal, Sadiq Omer

Civil & Environmental Engineering Theses & Dissertations

The depletion of resources has raised interest in reusing or incorporating by-products into alternative materials. In the effort for net zero emissions, waste reduction, and a circular economy, it is crucial to reinvent the alternative utilization strategy for by-products as construction materials sustainably. This research examines the alternative utilization strategy for oyster shell by-products in regular stormwater pollutant removal best management practices (BMPs).

Numerous research has examined the utilization of oyster shell waste as a construction material in Asia and Europe, specifically focusing on the physical properties of crushed oyster shells as alternatives for aggregates. No studies have been identified …