Engineering Commons^™

Adaptive Laboratory Evolution Of Scenedesmus Obliquus For Increased Carbohydrate Content And Biomass Productivity, Nahel Ali

Master's Theses

The economics of microalgal bioproduct commercialization would benefit from increased accumulation of energy storage compounds, such as carbohydrates and lipids, and increased biomass productivity. This thesis explores two adaptive laboratory evolution strategies for improving Scenedesmus obliquus: single UV-mutagenesis and low light cultivation at a high dilution rate to produce cultigens with greater carbohydrate content and iterative UV-mutagenesis and selection under outdoor conditions in a raceway pond at a high dilution rate to increase biomass productivity.

Two cultigens were generated with the goal of increased carbohydrate content: K5 and K7. Both were mutagenized for 5 seconds and cultivated in 50-mL …

Machine Learning Approaches To Historic Music Restoration, Quinn Coleman

Master's Theses

In 1889, a representative of Thomas Edison recorded Johannes Brahms playing a piano arrangement of his piece titled “Hungarian Dance No. 1”. This recording acts as a window into how musical masters played in the 19th century. Yet, due to years of damage on the original recording medium of a wax cylinder, it was un-listenable by the time it was digitized into WAV format. This thesis presents machine learning approaches to an audio restoration system for historic music, which aims to convert this poor-quality Brahms piano recording into a higher quality one. Digital signal processing is paired with two machine …

The Effect Of Focused Ultrasound On Altering The Diameter Class Of Nerve Fibers Contributing To A Compound Evoked Potential, Analyzed Using A Perturbative Decomposition Technique., Megan Wurden

Master's Theses

Peripheral neuropathies are disorders that involve the damage of peripheral nerve fibers, affecting the ability of different parts of the body to communicate. A differentiating factor in diagnosis between various clinical conditions can be which size class of nerve fibers are affected. A nerve conduction velocity test can be used to assess the viability of the nerve but is a single-parameter test and gives no information about the population characteristics of the remaining active fibers. A method developed and previously reported by Szlavik (2016) utilizes a mathematical perturbed decomposition to determine the normalized frequency of each size class of fiber …

Development Of A Hybrid Particle Continuum Solver, Anthony J. Gay

Master's Theses

When simulating complex flows, there are some physical situations that exhibit large fluctuations in particle density such as: planetary reentry, ablation due to arcing, rocket exhaust plumes, etc. When simulating these events, a high level of physical accuracy can be achieved with kinetic methods otherwise known as particle methods. However, this high level of physical accuracy requires large amounts of computation time. If the simulated flow is in collisional equilibrium, then less computationally intensive continuum methods, otherwise known as fluid methods, can be utilized. Hybrid Particle-Continuum (HPC) codes attempt to blend particle and fluid solutions in order to reduce computation …

Early Wildfire Detection With Line Sensors, Virginia Yan

Master's Theses

Over the last few years, wildfires have become more devastating to communities as the fires are inevitably destructive to many homes, businesses, and ecosystems. Frequent wildfires also pose a significant threat to power grids and nearby residents as they can damage transmission lines and other electrical equipment, which in turn can cause major power shutdowns. Especially in western U.S., severe drought conditions and weather variability cause residents to become more vulnerable to wildfire disasters as their safety is threatened. We are incompetent to control the wildfires effectively despite existing advanced technologies. Hence, an algorithm based on energy conservation and heat …

Development Of A Robust Methodology To Obtain And Assess Myogenic Precursor Cells For Their Use In Regenerative Therapies, Ricardo Lasa

Master's Theses

Peripheral arterial occlusive disease (PAOD) is characterized by buildup of atherosclerotic plaque in peripheral arteries that leads to an occlusion that can interrupt the supply of blood to the peripheral tissue, causing downstream tissue ischemia/hypoxia. PAOD is estimated to affect over 200 million patients worldwide. Current surgical revascularization treatments can be effective in about half of the patient population, leading to a significant number of patients with no treatment options beyond pharmacological intervention and lifestyle modification. The decrease in blood flow downstream of the occlusion leads to increased blood pressure gradient in the microvasculature, specifically in vessels that connect arterial …

Development Of Novel Hardware And Software For Wind Turbine Condition Monitoring, Ryan A. Zhan

Master's Theses

With the increased use of wind turbines as sources of energy, maintenance of these devices becomes more and more important. Utility scale wind turbines can be time consuming and expensive to repair so an intelligent method of monitoring these devices is important. Commercial solutions for condition monitoring exist but are expensive and can be difficult to implement. In this project a novel condition monitoring system is developed. The priority of this system, dubbed the LifeLine, is to provide reliable condition monitoring through an easy-to-install and low-cost system. This system utilizes a microcontroller to collect acceleration data to detect imbalances on …

Experimental Investigation Of The Effects Of Acoustic Waves On Natural Convection Heat Transfer From A Horizontal Cylinder In Air, Katherina V. Prodanov

Master's Theses

Heat transfer is a critical part of engineering design, from the cooling of rocket engines to the thermal management of the increasingly dense packaging of electronic circuits. Even for the most fundamental modes of heat transfer, a topic of research is devoted to finding novel ways to improve it. In recent decades, investigators experimented with the idea of exposing systems to acoustic waves with the hope of enhancing thermal transfer at the surface of a body. Ultrasound has been applied with some success to systems undergoing nucleate boiling and in single-phase forced and free convection heat transfer in water. However, …

Ram Air-Turbine Of Minimum Drag, Raymond Akagi

Master's Theses

The primary motivation for this work was to predict the conditions that would yield minimum drag for a small Ram-Air Turbine used to provide a specified power requirement for a small flight test instrument called the Boundary Layer Data System. Actuator Disk Theory was used to provide an analytical model for this work.

Classic Actuator Disk Theory (CADT) or Froude’s Momentum Theory was initially established for quasi-one-dimensional flows and inviscid fluids to predict the power output, drag, and efficiency of energy-extracting devices as a function of wake and freestream velocities using the laws of Conservations of Mass, Momentum, and Energy. …

Tunable Cspb(Br/Cl)3 Perovskite Nanocrystals And Further Advancement In Designing Light Emitting Fiber Membranes, Sk Shamim Hasan Abir, Santosh K. Gupta, A. Ibrahim, Bhupendra B. Srivastava, Karen Lozano

Mechanical Engineering Faculty Publications

Cesium lead halide perovskite nanocrystals (NCs) have drawn a great deal of interest in optoelectronic and photonic applications due to their intrinsic and attractive photoluminescence properties. Though, their commercially viability is of concern due to their intrinsic instability. In this study, blue and green luminous PMMA-CsPbX3(X=Cl/Br) fibers were fabricated via forcespinning technique, where the polymer matrix encapsulated the NCs. Blue CsPbX3 NCs (b- CPX NCs) were synthesized at ambient conditions while blue to green CsPbX3 NCs (g-CPX NCs) fine color tuning was obtained after heat treatment at 150°C.Field emission scanning electron microscopy (FESEM) shows fibers with diameters in the single …

Gyroscopic Human Balance Device, Randy Lam Hau, Spencer Ross, Yael Farkash

Biomedical Engineering

This project’s sponsor, Charlie Guitierrez, has decades of experience building assistive walking devices for the wheelchair bound population. During his work, he noticed that many of his clients retained some ability to balance themselves and so theorized that they would be able to walk independently if given some form of assistance. This assistance could potentially be in the form of a wearable gyroscope. Gyroscopes are commonly used to stabilize objects subjected to instability, such as bicycles, motorcycles, and ships. Thus, a wearable gyroscope would assist its user in maintaining overall stability by imparting reactive torques and forces if the user …

Hypoxic Incubation Chamber, Makenzie Jones, Andrea Skattenborg, Henry Elsner

Biomedical Engineering

In developing a model to test anti-tumor drugs, Dr. Christopher Heylman’s lab requires the ability to culture cells in a hypoxic environment. The purpose of this project was to make this possible. Funding for this project comes from the Biomedical Engineering Department, the Hannah-Forbes Fund, and Dr. Heylman’s lab. The chamber must be able to reach a user-defined oxygen concentration and hold that concentration for 48 hours while creating an environment conducive to cell culture. Importantly, the chamber must also be sterilizable and cleanable for repeated use. While several products exist to create hypoxic environments for cell culture, they are …

Adaptive Augmentation Of Non-Minimum Phase Flexible Aerospace Systems, Michael A. Dupuis

Doctoral Dissertations and Master's Theses

This work demonstrates the efficacy of direct adaptive augmentation on a robotic flexible system as an analogue of a large flexible aerospace structure such as a launch vehicle or aircraft. To that end, a robot was constructed as a control system testbed. This robot, named “Penny,” contains the command and data acquisition capabilities necessary to influence and record system state data, including the flex states of its flexible structures. This robot was tested in two configurations, one with a vertically cantilevered flexible beam, and one with a flexible inverted pendulum (a flexible cart-pole system). The physical system was then characterized …

On Road Coordinates For Autonomous Vehicle Guidance, Ricardo Jacome

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

A new roadmap framework is proposed to improve the guidance and trajectory prediction capabilities of connected and automated vehicles (CAVs). Independent of road shape determination through external sensors, the system serves as a backup for challenging conditions, such as low sensor visibility and adverse environmental effects (e.g., rain, fog, snow). Based on the fusion of vehicle dynamics principles, differential geometry, and road design standards, the roadmap framework provides a consolidated collection of critical reference points of roadway centerlines and information about the shape of the roadway in the vicinity of a vehicle, including curvature, optimal travel velocity, and road alignment …

Safety Considerations For All Road Users On Edge Lane Roads, Michael Williams, Marcial Lamera, Aleksander Bauranov, Carole Voulgaris, Anurag Pande

Mineta Transportation Institute

Edge lane roads (ELRs), also known as advisory bike lanes or advisory shoulders, are a type of shared street where two-way motor vehicle (MV) traffic shares a single center lane, and edge lanes on either side are preferentially reserved for vulnerable road users (VRUs). This work comprises a literature review, an investigation of ELRs’ operational characteristics and potential road user interactions via simulation, and a study of crash data from existing American and Australian ELRs.

The simulation evaluated the impact of various factors (e.g., speed, volume, directional split, etc.) on ELR operation. Results lay the foundation for a siting criterion. …

Uncertainty Matters: Bayesian Probabilistic Forecasting For Residential Smart Meter Prediction, Segmentation, And Behavioral Measurement And Verification, Jonathan Roth, Jayashree Chadalawada, K. Rishee Jain, Clayton Miller

Research Collection College of Integrative Studies

As new grid edge technologies emerge—such as rooftop solar panels, battery storage, and controllable water heaters—quantifying the uncertainties of building load forecasts is becoming more critical. The recent adoption of smart meter infrastructures provided new granular data streams, largely unavailable just ten years ago, that can be utilized to better forecast building-level demand. This paper uses Bayesian Structural Time Series for probabilistic load forecasting at the residential building level to capture uncertainties in forecasting. We use sub-hourly electrical submeter data from 120 residential apartments in Singapore that were part of a behavioral intervention study. The proposed model addresses several fundamental …

Final Report - Autonomous Wall-Climbing Robots For Inspection And Maintenance Of Concrete Bridges, Jizhong Xiao, Liang Yang, Jinglun Feng, Ejup Hoxha

Project AS-3

This project developed wall-climbing robots to carry non-destructive evaluation (NDE) devices for automatic data collection and surface/subsurface defect detection in concrete structures. By using simultaneous localization and mapping (SLAM), the robots can be located to allow for incremental 3D model reconstruction. An image dataset with pixel-level accuracy is collected and labeled to train a deep neural network (i.e., InspectionNet) with 12,000 iterations for each defect type. A ground penetrating radar (GPR)-based subsurface object detection method is proposed to implement visual inertial fusion for the estimation of the GPR pose, use a deep neural network module (i.e., DepthNet) to extract hyperbola …

Preparations And Electrocatalytic Ethanol Properties Of Palladium Intercalated Hydrotalcite, Shou-Xun Hu, Liang Li, Jun-Hao Yang, Liu-Qiang Li, Zhi-Hao Jin

Journal of Electrochemistry

High-performance electrocatalysts play a vital role in the commercial application of direct fuel cells. Current anode materials still have such problems as low activity, easy poisoning and high cost. In this study, a new type of nano- palladium (Pd) catalyst was prepared by dipping method using layered double hydroxides (LDHs) as the carrier. X-ray diffractometer, scanning electron microscope (SEM), inductively coupled plasma mass spectrometer (ICP-MS), energy spectrometer, transmission electron microscope (TEM), cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscope were used to analyze the structure and electrocatalytic performance of the catalyst. The results showed that the newly prepared Pd/Mg-Al-LDHs still maintained …

Theoretical Study On Electrical Properties Of Molecular Junctions Of Viologen Derivatives, Zhuan-Yun Cai, Jia Liu, Si-Yuan Guan, De-Yin Wu, Zhong-Qun Tian

Journal of Electrochemistry

In this paper, the electrical properties of molecular junctions formed N,N′-bis(4-thioalkyl)-4,4′-bipyridinium (viologen) moiety between two gold (Au) electrodes have been investigated by combining density functional theory and non-equilibrium Green’s functional approach. To modulate the viologen molecule to be a cation with one and two positive charges (V⁺ and V²⁺), we introduce one and two trifluoroacetic acid ions (TFA^-) around the molecule, respectively. The valence states of V⁺ and V²⁺ are confirmed by checking Mulliken and NBO charges. Then the relationship between molecular conductance and electronic structures of the neutral state …

Preparation Of Pdcoir Tetrahedron Nanocatalysts And Its Performance Toward Ethanol Oxidation Reaction, Zhi-Yuan Yu, Rui Huang, Jie Liu, Guang Li, Qian-Tong Song, Shi-Gang Sun

Journal of Electrochemistry

As a new energy conversion device, direct ethanol fuel cells (DEFCs) are widely concerned because of their remarkable advantages such as high theoretical energy density and wide fuel sources. However, the rapid development of DEFCs has been severely impeded due to the sluggish kinetic process and toxic intermediates especially in their anodic reactions. Palladium (Pd)-based materials are considered to be excellent anode catalysts for DEFCs, especially under alkaline conditions. And further improving their performance is an important direction to promote the development of DEFCs. Surface structure and composition are the key factors affecting the performance of catalysts which can be …

Preparation And Performance Investigation Of Li-Sgo Doped Semi-Ipns Porous Single Ion Conducting Polymer Electrolyte, Yun-Feng Zhang, Jia-Ming Dong, Chang Tan, Shi-Kang Huo, Jia-Ying Wang, Yang He, Ya-Ying Wang

Journal of Electrochemistry

Herein, the lithiated sulfonated graphene oxide (Li-SGO) was successfully prepared via three steps by sulfonation of graphene oxide with 3-merraptnpropylt rimethnxysilane, oxidation of thiol into sulfonate with hydrogen peroxide and lithiation of sulfonate with aqueous lithium hydroxide. The as-prepared Li-SGO was then introduced into the semi-interpenetrating networks of single ion conducting polymer electrolyte (Li-SGO-FPAS) and poly vinylidenefluoride-hexafluoro propylene (PVDF-HFP) binder by in-situ polymerization to fabricate the porous single ion conducting polymer electrolyte membrane (Li-SGO-po-FPAS) generated from the poor compatibility between aromatic Li-SGO-FPAS and aliphatic PVDF-HFP binder. The key properties such as morphology, porosity, solvent uptake, mechanical …

Combined Applications Of Photocurrent Spectroscopy, Photoluminescence Spectroscopy And Uv-Vis Spectroscopy For Nano-Semiconductor Based Photoelectric Devices, Si-Da Bian, Jian-Zhang Zhou, Zhong-Hua Lin

Journal of Electrochemistry

The electronic structures and properties of nano-semiconductors are quite different from those of bulk semiconductors due to the nano-size effect (such as quantum size effect). Moreover, when the nano-semiconductor materials are deposited onto the substrate to construct a device, their electronic properties are also affected by the substrate or other components, which may lead to different performances of nano-semiconductors based photoelectric devices, and consequently, different corresponding characterization methods are needed. The combination of photocurrent spectroscopy, photoluminescence spectroscopy with UV-Vis absorption spectroscopy can provide a more comprehensive characterization for the electronic properties and photoelectrochemical performances of nano-semiconductors in photoelectric devices. Our …

Influence Of Resveratrol On Performance Of Long-Term Storage’S Lithium-Ion Battery Electrolyte, Lei Zhang, Xu-Ping Zhang, Si-Wei Zhang, Quan-Chao Zhuang

Journal of Electrochemistry

Electrolyte of lithium-ion battery usually goes through processes of filling, transportation and storage from the completion of manufacture to the use. Understanding the influence of long-term storage process on performance of lithium-ion battery electrolyte is of theoretical significance for production of lithium-ion battery. Scanning electron microscope (SEM) images showed that the solid electrolyte interface (SEI) film formed on the surface of the graphite electrode was thicker in the base electrolyte after 6 months of storage. The charge/discharge test results showed that the reversible cycle capacity and cycle stability (capacity retention rate) of graphite electrode decreased significantly after 6 months of …

Research Progress In Electrodeposition Technology Of Titanium-Based Iridium Oxide Electrode, Dan-Dan Wu, Xu Wu

Journal of Electrochemistry

Titanium-based iridium oxide electrode has been widely used in various fields, such as electrocatalytic oxidation, biomedical applications, hydrometallurgical metal recovery, electro-osmotic dewatering, etc. At present, it is mainly prepared by traditional thermal decomposition method, however, which has high cost, cumbersome process, mainly relying on manual labor and cannot be mass-produced yet. It is, therefore, urgently necessary to explore new preparation technologies by focusing on electrodeposition technology, with technological characteristics such as eco-friendly and sustainable development. This article systematically discusses the research progress in iridium oxide electrodeposition preparation technology from the aspects of deposition solution formulation, base material selection and treatment, …

Preparations And Electrochemical Properties Of Bc/Coni2S4@Ppy Flexible Composites For Supercapacitors, Si-Yuan Peng, Shi-Run Yang, Jing-Hong Zhou, Zhi-Jun Sui, Tao Zhang, Yi Shi, Xing-Gui Zhou

Journal of Electrochemistry

Flexible supercapacitor is one of the most promising energy storage devices for portable and wearable electronic products due to its advantages of high power density, fast charging and long cycle life. Therefore, self-supporting flexible electrode materials with high performance have attained more and more attention both in academia and in industry recently. In this work, using bacterial cellulose (BC) as a flexible substrate, the bacterial cellulose/nickel-cobalt sulfide@polypyrrole (BC/CoNi₂S₄@PPy) flexible composites with three-dimensional porous network and good conductivity were prepared by a combined solvothermal-in-situ polymerization-vacuum filtration method. The samples were characterized by X-ray diffraction, …

Syntheses Of Na3V2(Po4)2O2F As A Cathode For Sodium Ion Battery Application, Kai Wu

Journal of Electrochemistry

High-temperature solid-state method, hydro-thermal method and solvo-thermal method have been mainly employed to synthesize Na₃V₂(PO₄)₂O₂F (NVPF) cathode materials. However, these methods are energy consuming and complicated, which is not applicable for a large scale industrial production. In this study, a rather low-temperature (70℃) co-precipitation strategy was proposed to synthesize NVPF cathode materials. The as-prepared NVPF cathode materials showed a spherical shape with a diameter of 400 ~ 500 nm, and exhibited a sodium storage of 105.6 mAh·g^-1 and an efficiency of 90.06%. After a simple thermal process, the specific …

Research Progress On Transition State Of Organic Electrode Materials, Xue-Qian Zhang, Zhou-Guang Lu, Wei-Wei Huang

Journal of Electrochemistry

With the increasing requirements for high energy density, long lifetime, high safety, environmentally friendly fabrication, and sustainable development of large energy storage devices, the society calls for new electrode materials in rechargeable batteries beyond traditional inorganic materials which are limited by specific capacity. Organic electrode materials have been widely used in rechargeable batteries due to their advantages of large theoretical capacity, designable structures and environmentally friendly fabrications. In this review, the radical intermediates of organic electrode materials produced in the charging-discharging process (redox reaction) and their types are systematically reviewed. The stability of radical intermediates controlled by changing the structure …

Research Progress Of Sio2 Regrowth During Selective Etching Process In 3d Nand Manufacture Procedure, Zi-Han Zhou, Yun-Wen Wu, Ming Li, Su Wang

Journal of Electrochemistry

As one of the most significant memory chips in semiconductor market, NAND has been developed from two-dimension (2D) to three-dimension (3D). Due to the three-dimensional memory structure of 3D NAND, the capacity density, read-write speed and reliability of memory chips have been greatly improved, as well as the reduction of power dissipation. It is by nitride-oxide selective etching process in the alternate stacked structure of 3D NAND that the inter-dielectric layers can be obtained. The more stack layers, the better performance of chips will be. Meanwhile, however, silicon dioxide (SiO₂) would regrow on the corner of oxide layers, …

Study On Li3Bo3 Interface Modification Of Garnet Solid Electrolyte, Gui-Wei Chen, Zheng-Liang Gong

Journal of Electrochemistry

Garnet solid-state electrolytes have become the research hotspot due to their high ionic conductivity, wide electrochemical stability window and good air stability. However, there are still a series of problems to be solved. The poor contact between the lithium (Li) metal and garnet pellet make it difficult to build stable ion diffusion channels, resulting in large interfacial resistance. The continuous growth of lithium dendrites can penetrate the electrolyte pellet and cause a short circuit in the solid-state battery. Herein, a novel strategy is proposed to improve the wettability of LLZTO electrolyte with Li metal, via interfacial modification of LLZTO electrolyte …

Renewable Energy Generation And Ghg Emission Reduction Potential Of A Satellitewater Reuse Plant By Using Solar Photovoltaics And Anaerobic Digestion, Jonathan R. Bailey, Saria Bukhary, Jacimaria R. Batista, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Wastewater treatment is a very energy-intensive process. The growing population, increased demands for energy and water, and rising pollution levels caused by fossil-fuel-based energy generation, warrants the transition from fossil fuels to renewable energy. This research explored the energy consumption offset of a satellite water reuse plant (WRP) by using solar photovoltaics (PVs) and anaerobic digestion. The analysis was performed for two types of WRPs: conventional (conventional activated sludge system (CAS) bioreactor with secondary clarifiers and dual media filtration) and advanced (bioreactor with membrane filtration (MBR)) treatment satellite WRPs. The associated greenhouse gas (GHG) emissions were also evaluated. For conventional …