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Porous Triboelectric Nanogenerator For Load Sensing Of Total Knee Replacement, Elham Mahmoudi, Adam Garry Redgrift, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This study addresses the critical need for self-powered, durable pressure sensors in Total Knee Replacement (TKR) implants to enable the collection of post-operative information. The scope of this research encompasses the design, development, and testing of a triboelectric nanogenerator (TENG) integrated into an instrumented knee implant for energy harvesting and pressure sensing. The authors’ unique approach involves utilizing a porous silicone rubber as a dielectric material. This allows the TENG to withstand forces up to 2000 N and generate a maximum power output of 18 μW. Theoretical modeling combined with experimental validation provides deeper insight into the fundamental operating principles. …

Surface Reaction And Transportation Of Radium-226 In Marine Systems, Jiusi Wang

All Dissertations

Historical uses of radium (Ra)-containing self-luminous paint, such as on gauges and dials in naval ships, have led to the potential for such paint, and thus Ra, to be released into the marine environment. Radium-226 (²²⁶Ra) behavior in marine systems is not fully described in the literature, presenting a knowledge gap in the process of evaluating potential ecological impact of Ra in marine systems. This study explores various mechanisms contributing to Ra environmental transport in marine systems on a laboratory scale, including leaching, sorption, and diffusion. ²²⁶Ra leaching from watch hand dials containing radioactive luminous paint is …

Strategic Enhancement Of Biofuel Production Using Bacillus Subtilis As A Model Organism: A Dual Approach Of Gene Essentiality Mapping And Optimization, Angela A. Zebede

Electronic Theses and Dissertations

With rising global demand for renewable energy, enhancing microbial platforms for biofuel production is vital. This study engineered Bacillus subtilis to improve resilience to solvent stress by targeting membrane lipid biosynthesis pathways essential for integrity. Growth curve analysis (OD₆₀₀) showed that phosphatidylserine (PS) and phosphatidylethanolamine (PE) knockout strains grew significantly slower than wild type (168), indicating the importance of these lipids under stress. Laurdan fluorescence spectroscopy was used to assess membrane properties. Generalized polarization (GP) analysis revealed a concentration-dependent reduction in membrane order upon 1%–2% 1-butanol exposure. GP values declined progressively from control to 2% treatment, reflecting increased membrane fluidity …

Calibration And Validation Of Cyclic Stretching Platform For Stiffness Testing Of Engineered Heart Tissue, Jillian Welsh

Chemical Engineering Undergraduate Honors Theses

Cardiac fibrosis (CF) is a major contributor to the high mortality rate of heart failure which affects over 23 million people worldwide. CF involves cardiac fibroblasts depositing extracellular matrix, made primarily of collagen type I, which stiffens the heart walls over time. As testing new drugs for CF is deterred by the high cost and time required for animal and clinical trials, this research helps to solve the problem by providing an in vitro platform to study fibrosis.

The work involved creating tissues containing human cardiac fibroblast (HCFB) cells. Spring testing was conducted to determine the force applied by the …

Per- And Poly-Fluoroalkyl Substances Fate Across California Wastewater Treatment Plants: A Meta-Analysis Of Formation, Distribution, And Persistence, Elizabeth Reineke

Master's Theses

Per- and poly-fluoroalkyl substances (PFAS) are persistent contaminants that move through municipal and industrial wastewater systems with limited attenuation. As a result, they are increasingly detected in drinking water supplies. Despite growing regulatory concern, a systems-level understanding of PFAS behavior across multiple treatment facilities and watershed settings remains incomplete. This study compiled influent, effluent, and biosolids datasets from more than one hundred California wastewater treatment plants to evaluate PFAS occurrence, transformation, and partitioning across diverse treatment configurations. Analytical steps included calculating removal efficiencies, assessing precursor-to-product oxidation, evaluating co-contaminant correlations, and grouping facilities by process design to quantify configuration-specific fate patterns. …

Coupling Material Formulation Strategies To Tailor Piezoelectric Properties Of Ceramic Lattices, Amanda Lauren Borgaro

Open Access Theses & Dissertations

This thesis examines the material formulation and infiltration processes required to create interpenetrating ceramic composites with a particular focus on developing piezoelectric ceramic-epoxy lattice structures (PCELS). Following this, a high–solid loading barium titanite photopolymer resin (BT40) was developed to produce BTO scaffolds with controlled porosity suitable for metal infusion. The resin’s shear-thinning behavior and scattering-dominated curing response enabled the formation of stable, uniform ceramic structures whose pore networks directly influence infiltration behavior. Building on this foundation, a low-temperature Field’s Metal (FM) infiltration method was established using controlled thermal equilibration and the melting of pre-formed alloy rods. By maintaining the ceramic …

Computational Methods For Complex Electromagnetic Geometries And Media, Edgar Bustamante

Open Access Theses & Dissertations

Additive manufacturing has enabled electromagnetic devices with increasingly complex geometries, but existing numerical tools remain limited in their ability to model and design such structures. This dissertation presents two major advancements that address these restrictions in the finite-difference frequency-domain method (FDFD) and the spatially-variant lattice algorithm (SVLA). These two numerical methods provide a foundation for future exploration in the simulation, optimization, and realization of next-generation electromagnetic devices. First, a general bianisotropic FDFD formulation based on the vector wave equation is presented that enables practical modeling of metamaterials using effective medium homogenized parameters rather than explicitly resolving subwavelength metamaterial features. The …

Development Of Oxide And Oxynitride Thin Films For Advanced Optical Applications, Nathan Christopher Episcopo

Open Access Theses & Dissertations

To develop Ga2O3 and TiOₓNᵧ thin films for optical applications, the process–structure–properties relationship was investigated using a comprehensive set of characterization techniques to establish the atomic structure and composition of the films in relation to the deposition conditions. The results provide critical insights into how deposition parameters influence the atomic structure and composition during magnetron sputtering. Furthermore, the correlation between atomic structure and composition with the optical and electrical properties of the films was examined to determine how variations in these factors affect functional performance. Collectively, these findings offer the necessary information to target desirable optical properties for Ga2O3 and …

One Step Fabrication: Software-Automated Printed Circuits Via Multi-Material Additive Manufacturing, Gabriel Sanchez

Open Access Theses & Dissertations

As of now, the creation of 3D printed components faces many issues regarding stability, repeatability, and manual labor. Existing methods lack an integrated software framework that automates circuit generation while ensuring predictable behavior in printed geometries. In this work, circuits are modeled by leveraging distributed equations that reduce to lumped approximations when the printed geometry remains uniform. The system is implemented through a parametric, domain-specific programming workflow and evaluated across 100 Hz to 100 kHz to assess the accuracy of the predicted electrical values. Printed results were validated by empirical studies involving an RLC meter and by comparing both theoretical …

Utilizing Diatoms In Wastewater Treatment For Pollutant Removal, Ceaira D. Howard

All Graduate Theses and Dissertations, Fall 2023 to Present

Wastewater treatment systems are increasingly challenged by a complex mix of pollutants including excess nutrients, organic dyes, and persistent chemicals like per- and polyfluoroalkyl substances (PFAS). Conventional treatment technologies often struggle to effectively and affordably remove these contaminants. This study explores the use of two diatom species, Phaeodactylum tricornutum and Navicula cryptocephala var. veneta, both single-celled microalgae with silica-based cell walls, as an environmentally sustainable approach to tertiary wastewater treatment. Diatoms offer dual functionality through surface adsorption properties and metabolic flexibilities, making them promising candidates for integrated treatment strategies.

To test the trophic flexibilities of diatoms, P. tricornutum was …

Lace Network Firmware: A Polarfire Fpga Network For Data Routing And Command Interfacing In Space Applications, Kade C. Howes

All Graduate Theses and Dissertations, Fall 2023 to Present

Modern small spacecraft rely on powerful yet efficient onboard compute devices to process data from sensors in real-time due to tight power and volume constraints. This work explores a new compute device system built from PolarFire Field-Programmable Gate Arrays (FPGAs), which are power-efficient, reprogrammable chips well-suited for space applications. The system connects via a central controller FPGA with one or multiple companion processing FPGAs, allowing sensor data to be quickly received and shared across the network. Standardized data formats and interfaces increase compatibility with spacecraft computers. By simplifying data handling and using high-speed communication links, this architecture makes it easier …

Effect Of Build Parameters On Mechanical Properties And Residual Stresses Of Lp-Ded Inconel 718 Overhanging Structures, Angel Fernando Bravo

Open Access Theses & Dissertations

Additive manufacturing of Inconel 718 via laser powder direct energy deposition (LP-DED) offers design flexibility for repair and fabrication of large components. However, mechanical properties remain sensitive to process parameters and geometric constraints, which impact the consistency of material properties. This study investigates the effect of different build angles (0°, 20°, 30°, and 35°) at different laser powers (1070W and 2000W) on the mechanical properties and residual stresses. Eight overhanging structures were fabricated using Inconel 718 and subjected to various heat treatments (SR + HIP + SOL + Aging). Numerical simulations were developed to predict residual stresses in the samples, …

Establishing Procedures For Primary Human Myoblast Cell Culture, Erica Duffy

Biomedical Engineering

Peripheral Artery Disease (PAD) affects an estimated 200 million people worldwide and is the leading cause of amputation in the United States. PAD is characterized by atherosclerotic narrowing of arteries, resulting in ischemia from reduced blood flow to distal tissues. Although surgical and percutaneous interventions can restore perfusion, fewer than 50% of patients experience sustained benefit, highlighting the need for alternative therapeutic strategies. One promising approach is promoting arteriogenesis, the growth and outward remodeling of pre-existing collateral vessels that improve blood flow around the occluded arteries. Arteriogenesis is regulated by regenerative, M2-polarized macrophages, making macrophage polarization a key therapeutic target. …

Thermal Management With Supercritical Carbon Dioxide Under Extreme Applications, Devon Hardy

Doctoral Dissertations and Master's Theses

A unique challenge in thermal system design is minimizing the power required to operate cooling systems while maintaining effective heat removal. Traditional cooling systems utilize single-phase fluids where the heat transfer mechanisms are well understood. To meet a variety of cooling demands, a range of technologies are available, including microchannel forced convection, jet impingement, porous media, nanofluids, pin fin arrays, and film cooling, each offering distinct advantages and limitations. While the performance of single- or two-phase cooling systems are generally predictable, in extreme thermal environments, new cooling solutions are needed to improve overall system efficiency and reliability.

Supercritical fluids, particularly …

Purifying Circular Rna Therapeutics, Karen Guillen-Cuevas

All Dissertations

Circular RNA (circRNA) has emerged as a promising therapeutic modality due to its enhanced stability and resistance to exonuclease degradation compared with linear mRNA. However, its stability and functionality depend strongly on achieving high purity, and current methods such as size-exclusion chromatography suffer from peak overlap, low yields, and poor scalability. This dissertation addresses these limitations by developing ultrafiltration-based strategies to purify circRNA directly from in vitro transcription (IVT) and self-splicing (circularization) reactions. First, the feasibility of ultrafiltration was demonstrated using polyethersulfone membranes, where sieving coefficients and critical flux values of circRNA, precursor RNA, and nicked RNA were measured to …

Diseño Visual, Identidad De Género Y Diversidad Cultural En La Animación Contemporánea: El Caso De Raya And The Last Dragon, Elisabet Fonts González

GDI. Revista de investigación de Género, Diseño e Innovación

En los últimos años, la animación ha evolucionado hacia representaciones más inclusivas de género y diversidad cultural. Raya and the Last Dragon (López Estrada & Hall, 2021) destaca como un caso significativo de esta transformación, integrando elementos visuales, narrativos y simbólicos que reconfiguran los arquetipos femeninos tradicionales. Este estudio adopta un enfoque cualitativo centrado en el análisis visual, narrativo y simbólico de los personajes Raya, Namaari y Sisu. Basándose en fuentes primarias del proceso creativo y marcos teóricos de la animación y los estudios de género (Furniss, 2017; Lauretis, 1987; Wells, 1998), presta especial atención al diseño de personajes, la …

Elena Asins Y Las Afueras Del Canon: Animación Computacional Y Resistencia, Maria Mar Garrido Román

GDI. Revista de investigación de Género, Diseño e Innovación

Este artículo examina las animaciones generadas por ordenador producidas por Elena Asins, analizando cómo su práctica artística moviliza el pensamiento lógico-matemático, la programación y la experimentación visual. A través de una revisión de su metodología, contexto de producción y resultados formales, el estudio explora la incorporación de procesos algorítmicos en su obra, que generan imágenes con extensión temporal y la consolidan como una figura clave en la historia del arte digital y la animación experimental en España.

La investigación se basa en el análisis de fuentes primarias y, con el objetivo de situar su producción en un marco internacional, establece …

Una Animación Propia. Discurso Emancipador Desde El Cine De Animación Independiente, Elisa Martínez, Damià Jordà

GDI. Revista de investigación de Género, Diseño e Innovación

Introducción: A pesar de la temprana incorporación de las mujeres a la industria de la animación, sus roles fueron históricamente relegados a labores mecánicas, limitando su capacidad de decisión creativa. Este artículo analiza cómo el cine de animación independiente del siglo XX funcionó como un espacio esencial para las directoras que buscaban un control artístico que permitiera desarrollar discursos emancipadores. Se parte de la hipótesis de que el circuito independiente propició que las animadoras desarrollaran técnicas y narrativas alternativas que rompieron con los cánones plásticos y los preceptos ideológicos dominantes en la industria. Metodología: Mediante una metodología cualitativa, …

Colaboración, Discurso Y Técnicas: La Resistencia Simbólica En El Sueño De La Sultana (Isabel Herguera, 2023), Nerea Cuenca-Orellana

GDI. Revista de investigación de Género, Diseño e Innovación

La película El sueño de la sultana (Isabel Herguera, 2023) reinterpreta el cuento utópico homónimo de Rokeya Sakhawat Hossain (1905) realizando una exploración visual que combina animación, archivo y testimonio. El presente trabajo propone un análisis de la obra desde cuatro puntos clave e interrelacionados: la autoría colaborativa y femenina, los discursos visuales, los lenguajes y técnicas, y las formas de resistencia simbólica con el objetivo principal de establecerla como un caso práctico de diseño feminista contemporáneo.

En primer lugar, se examina el proceso de creación de la película como práctica colaborativa transnacional, donde la animación se convierte en un …

Design Principles For Customer‑Engaging Digital Service Systems: An Action Research Study, Keng Siau, Xiaofeng Chen, Xin Tan

Research Collection School Of Computing and Information Systems

Digital services represent a business approach employed by organizations to operate in the digital environment. However, systematic development guidelines for developing quality digital service systems are lacking in the literature. The authors identified four general challenges for developing and implementing customer-engaging digital service systems (CEDSS). By employing the method of canonical action research in a digital service system project, they derived 10 design principles for developing high-quality CEDSS. They empirically evaluated the design principles in the development project and through follow-up focus group sessions. The design principles provide applicable and actionable guidelines for the development of CEDSS.

Private Sand Mining In The Mississippi River: Sediment Budget And Morphology Implications Between Baton Rouge And Belle Chasse, Louisiana, Brett Mcmann

LSU New Orleans Theses and Dissertations

This analysis examined how private sand mining within the Mississippi River between Baton Rouge, LA and Belle Chasse, LA affected its sand budget from 2004-2012.

Records assembled indicated that private mining removed an annual average of 2.8 million cubic yards of sand. A HEC-RAS one-dimensional sediment transport model was utilized to assess this practice. Three scenarios were simulated: a baseline without mining, conditions reflecting documented mining rates, and a hypothetical case with excessive extraction.

Results suggest that private mining constituted approximately 26 percent of the total sand deficit between Baton Rouge and Belle Chasse. Mining appeared to cause localized changes …

Investigation Of Laser Based Flow Diagnostics With Metastable Argon, Sterling S. Gordon

Physics Theses & Dissertations

The overarching motivation of this work is the development of seedless, non-intrusive, laser-based diagnostics for supersonic airflow in wind tunnels. To advance this goal, this dissertation fo-cuses on three-photon excitation in a research-grade argon beam within a tabletop vacuum system, which offers a controlled environment for testing and refining the approach. The chosen excitation scheme drives argon atoms to the 3d[5/2]₃ state using a pulsed Ti:Sapphire laser system, enabling time-of-flight (ToF) measurements on atoms that subsequently undergo a multi-step decay to the metastable 4s[3/2]₂ state. Although full realization of this excitation scheme was hindered by technical …

Effect Of Capillary And Viscous Forces On Carbon Dioxide Desorption In Porous Adsorbent Layers, Caroline Isabel Mcclung

Theses and Dissertations

Temperature swing adsorption-based (TSA) carbon dioxide (CO₂) separation processes, which involve an alternating flow of gases and liquids in adsorbent-coated microchannels, have been shown to yield superior and environmentally friendly performance than the existing processes. This technique begins by sending the impure gas mixture through hydrophobic silicalite adsorbent-coated microchannels, which results in the adsorption of CO₂. Subsequently, hot water heat transfer fluid (HTF) flows through the same channels, displaces the purified gas stream, heats the adsorbent, desorbs the CO₂, and removes that desorbed CO₂ from the channel. This stage is followed by cooling …

Theory And Technology Of Enhanced Coal Seam Gas Production By Integrated Drilling, Punching And Fracturing In Coal Mine: Part 1 Theory, Shiyao Yu, Xianbo Su, Jinxing Song, Qian Wang, Zhenjiang You

Research outputs 2022 to 2026

Coal seams in China are typically characterized by high coal seam gas content and low permeability, posing challenges for efficient coal seam gas extraction. However, achieving successful boreholes, especially in soft coal formations, remains a challenge. The mechanisms underlying permeability improvement in different coal structures need further exploration. Therefore, this paper is focused on the fundamental principles of permeability improvement in soft coal through hydraulic punching, and in hard coal via hydraulic jet fracturing. Firstly, borehole instability results from a dynamic interplay of four factors: in situ stress, coal structure, mechanical properties of coal with fluid, and drilling technology. While …

Experimental Study On Stability, Rheology, And Co2 Storage Capacity Of Polymer-Enhanced Foams In Carbonates, Muhammad Mushtaq, Mudassar Mumtaz, Emad W. Al-Shalabi, Waleed Alameri, Georgios N. Karanikolos, Stefan Iglauer

Research outputs 2022 to 2026

Polymer-enhanced CO2 foam (PEF) is an emerging technology that improves gas mobility control in chemical enhanced oil recovery applications. It also has significant potential for storing CO2 in geological formations, which can help mitigate anthropogenic emissions. Traditional surfactant-based foams are often weak and unstable, particularly under the high-salinity and high-temperature conditions commonly found in Middle Eastern carbonate reservoirs. However, adding a small amount of stable polymer to these foams can enhance their stability, rendering them more suitable for harsh environments. This study focuses on designing and thoroughly evaluating a PEF formulation under supercritical CO2 conditions at 95 °C temperature, 1500 …

Improvement Of Thermal Energy Storage Performance In Al-Al2o3 Composites Through Additions Of Copper: Evaluation Of Microstructure And Thermal Properties, Muhammad Hasan Basri, Ramang Magga, Muhammad Syaiful Fadly, Zikri Arifansyah Djaba, Muhammad Iqbal Ibrahim, Hidayat Hidayat, Yandi Yandi

Journal of Mechanical Engineering Science and Technology (JMEST)

The study aims to evaluate the influence of adding copper aluminum–alumina composite (Al–Al₂O₃) against characteristic thermal properties through metallurgical powder. Three variations of the composition of weight copper were used, namely 5%, 10%, and 15%, with aluminum as the matrix and alumina as the reinforcement. Thermal test covering analysis of thermal conductivity, specific heat, and microstructure characterization using SEM-EDX. The results show that adding Cu increases thermal conductivity significantly, with the highest mark achieved in the 15% Cu composite (6.47 W/m.°C). However, the increase in Cu content above 10% causes the agglomeration of particles and enhancements in porosity, which harms …

Spray Angle On The Performance Of Split-Type Ac Condenser Installed On Concrete Rooftop In Tropical Climate, Kennedy Kennedy, I N Frenki Aryana, Basri Basri

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigated the influence of different water spray angles (0°, 15°, and 30°) on the thermal and energy performance of a split-type air-conditioning (AC) condenser installed on a concrete rooftop in a tropical climate. An experimental setup was designed to replicate actual concrete rooftop conditions, focusing on the condenser inlet temperature, compressor power consumption, and system coefficient of performance (COP). A 6-minute ON and 6-minute OFF intermittent spray cycle was employed to optimise water usage and minimise excessive humidity. Experimental measurements were conducted on a 9,000 Btu/h split-type unit equipped with a nozzle system connected to a 200 L …

Surface Modification Of Local Natural Fibers Via Alkali Treatment For Improved Mechanical And Molecular Properties Of Bamboo Fiber, Pineapple Leaf Fiber, And Sisal Fiber, Jibril Maulana, Muhammad Ilman Nur Sasongko, Dewi Izzatus Tsamroh, Muchammad Yafis, Syekhan Maulana

Journal of Mechanical Engineering Science and Technology (JMEST)

A major development in materials science toward reinforcement materials in biopolymer composites has been caused by a worldwide trend toward sustainable manufacturing and the rise of the circular economy. However, their mechanical properties can often be affected by their hydrophilic properties, lack of surface compatibility, and their presence of molecular bonding, such as lignin and hemicellulose. Alkaline surface modification has been widely reported as an effective technique to increase structural stability and fibermatrix adhesion. This study evaluated the effects of alkalizing three types of local natural fibers—bamboo fiber (BF), pineapple leaf fiber (PALF), and sisal (SF)—with sodium hydroxide (NaOH) at …

Thermophysical, Rheological And Wear Resistance Of Canola Oil Biolubricant With Calcium Carbonate Additive Nanoparticle As Coolant In Cnc Machining, Alfandi Jaelani, Poppy Puspitasari, Diki Dwi Pramono, Alief Muhammad, Muhammad Kozin, Muhammad Kashif

Journal of Mechanical Engineering Science and Technology (JMEST)

Vegetable oil-based cutting fluids are of great importance in supporting green and sustainable manufacturing. This research introduces a new groundbreaking vegetable lubricant formulated with canola oil as the base material, coupled with CaCO3 nanoparticles synthesized from scallop shell waste and used as a cutting fluid in the AISI 1045 CNC machining process steel sprayed with minimum quantity lubrication (MQL). This investigation delves into the thermophysical, rheological, and wear resistance of the developed bio-lubricant. The results of this analysis show density value increased in the canola + CaCO3 0.15% sample by 3.28% of the pure canola sample, as did the viscosity …

One-Way Thermal-Fluid-Solid Coupling Analysis Of Helicopter Tail Reducer With Spiral Bevel Gear, Dongping Sheng, Zhongyuan Ma, Chenqi Zhou, Haidong Feng, Hun Guo, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

This research focuses on investigating the thermal-fluid-solid coupling behavior within spiral bevel gears to enhance the bearing capacity and extend the operational service life of the gear reducer located in the helicopter tail gearbox. The study commences by constructing detailed, parametrically defined threedimensional digital models. These models accurately represent the critical components: the spiral bevel gear itself, the surrounding gearbox housing, and the supporting gear shaft, based directly on the specifications of an actual helicopter tail reducer assembly. Subsequently, the analysis proceeds with a one-way, steadystate thermal-solid coupling simulation performed on the established model assembly. This critical simulation phase aims …