Engineering Commons^™

Study Of The Various Charactertics Of A Helical Vertical Axis Wind Turbine Compared To A Straight Bladed Darrieus Design, Patrick Quinlan

Theses and Dissertations

As the wind energy market continues to expand, the need for a more diverse range of wind turbine technologies becomes increasingly apparent. Horizontal axis wind turbines (HAWT) have become the standard design for wind turbines over the past few decades and have been the go-to design used in wind farms both on land and off-shore. However, in residential and urban environments other types of turbine designs can help expand the reach of wind energy. Specifically, vertical axis wind turbines (VAWT) have shown potential for new applications of wind turbines in areas that are less suitable for typical HAWTs. The most …

High Power, Medium Frequency, And Medium Voltage Transformer Design And Implementation, Ahmad El Shafei

Theses and Dissertations

Many industrial applications that require high-power and high-voltage DC-DC conversion are emerging. Space-borne and off-shore wind farms, fleet fast electric vehicle charging stations, large data centers, and smart distribution systems are among the applications. Solid State Transformer (SST) is a promising concept for addressing these emerging applications. It replaces the traditional Low Frequency Transformer (LFT) while offering many advanced features such as VAR compensation, voltage regulation, fault isolation, and DC connectivity. Many technical challenges related to high voltage stress, efficiency, reliability, protection, and insulation must be addressed before the technology is ready for commercial deployment. Among the major challenges in …

Microbial Ecology Of Urban Sewers, Emily Lou Lamartina

Theses and Dissertations

Municipal sewage provides a glimpse into the health and activities of a human society. For more than a century, sewage exploration has helped expose the sources of disease outbreaks and track disease progression over time. Recent advancements in wastewater surveillance born from the COVID-19 pandemic have potential to enhance mitigation efforts against the decades-long global health crisis of microbial antibiotic resistance. However, critical knowledge gaps exist in wastewater surveillance, stemming from a lack of understanding in sewer microbial ecology. Ecology reveals trends in how communities respond and adapt to change, which has far-reaching implications for identifying effective strategies for disease …

Design, Development, And Control Of A Robotic Gripper For Activities Of Daily Living (Adl) Assistance., Jaime Rafael Hernandez

Theses and Dissertations

This research contributes to developing a robotic gripper designed to improve the performance of assistive robots to help people with upper limb impairment due to stroke, injury, and other trauma. As developed in this research, the gripper for assistive robots (GAR) can be an alternative solution to the existing robotic grippers increasing the benefits in different ways, including the cost/benefits ratio and the range of graspable objects.

The GAR has been designed with simplicity in mind with a minimum viability approach. The design, construction, control, and operation of this robotic hand have been simplified with a minimal number of custom-made …

Wheelchair-Mounted Assistive Robot For Activities Of Daily Living: Design, And Validation, Elias Jose Munoz Montenegro

Theses and Dissertations

In the last decades, the number of wheelchair users has been increasing at an alarmingrate. Part of these individuals has an upper or lower dysfunction (ULED) resulting from a stroke, spinal cord injury, trauma, accident, or workplace injuries. Due to this, these patients need assistance to conduct their activities of daily living (ADLs). Hence, Wheelchair-Mounted Assistive Robots (WMAR) have a crucial role in Individuals with ULED. This research focuses on the design optimization, development, and validation of WMARs for essential ADLs. The design aims to obtain the link lengths with the most workspace coverage. Moreover, the analysis includes singularity avoidance …

Characterization And Composition Of Corrosion Scales In Drinking Water Distribution Systems, Adam Schmidt

Theses and Dissertations

Internal corrosion of drinking water pipes has received considerable attention recently in the media and in academic studies due to compliance and monitoring regulations with the Lead and Copper Rule (LCR) established by the EPA in 1991. Notable health crises involving municipalities exceeding the LCR in Washington D.C. and Flint, Michigan occurred when corrosion scale conditions changed from stable to soluble lead compounds due to changing water chemistry, leaching high amounts of lead into consumers drinking water. Understanding the role of the corrosion scale in the process of leaching lead and other toxic trace metals such as arsenic is vital …

Study Of The Various Charactertics Of A Helical Vertical Axis Wind Turbine Compared To A Straight Bladed Darrieus Design, Patrick Quinlan

Theses and Dissertations

As the wind energy market continues to expand, the need for a more diverse range of wind turbine technologies becomes increasingly apparent. Horizontal axis wind turbines (HAWT) have become the standard design for wind turbines over the past few decades and have been the go-to design used in wind farms both on land and off-shore. However, in residential and urban environments other types of turbine designs can help expand the reach of wind energy. Specifically, vertical axis wind turbines (VAWT) have shown potential for new applications of wind turbines in areas that are less suitable for typical HAWTs. The most …

Deciphering The Firing Patterns Of Hippocampal Neurons During Sharp-Wave Ripples, Kourosh Maboudi Ashmankamachali

Theses and Dissertations

The hippocampus is essential for learning and memory. Neurons in the rat hippocampus selectively fire when the animal is at specific locations - place fields - within an environment. Place fields corresponding to such place cells tile the entire environment, forming a stable spatial map supporting navigation and planning. Remarkably, the same place cells reactivate together outside of their place fields and in coincidence with sharp-wave ripples (SWRs) - dominant electrical field oscillations (150-250 Hz) in the hippocampus. These offline SWR events frequently occur during quiet wake periods in the middle of exploration and the follow-up slow-wave sleep and are …

Mechanical Erosion Investigation Through The Solid Rocket Motor’S Nozzle, Mohamed Ahmed Abdelazim Abousabae

Theses and Dissertations

The solid rocket motor (SRM) is considered one of the essential engines that facilitatesaerospace research; thus, investigating the propellant burning process is vital. One of the challenges facing its growth is the oxidization of the aluminum into aluminum oxide at the exhaust’s high pressures and temperatures. The oxidized aluminum forms agglomerates, impinge on the exit nozzle walls, causing severe damage (erosion) to the nozzle material. Thus, the present work attempts to investigate and reduce this erosion. Two different approaches are followed in the current work, the first one aims to better understand the aluminum oxide agglomerates break-up mechanism and the …

Image-Based Cancer Diagnosis Using Novel Deep Neural Networks, Hosein Barzekar

Theses and Dissertations

Cancer is the major cause of death in many nations. This serious illness can only be effectivelytreated if it is diagnosed early. In contrast, biomedical imaging presents challenges to both clinical institutions and researchers. Physiological anomalies are often characterized by modest modifications in individual cells or tissues, making them difficult to detect visually. Physiological anomalies are often characterized by slight abnormalities in individual cells or tissues, making them difficult to detect visually. Traditionally, anomalies are diagnosed by radiologists and pathologists with extensive training. This procedure, however, demands the participation of professionals and incurs a substantial expense, making the classification of …

Use Of Machine Learning And Natural Language Processing To Enhance Traffic Safety Analysis, Md Abu Sayed

Theses and Dissertations

Despite significant advances in vehicle technologies, safety data collection and analysis, and engineering advancements, tens of thousands of Americans die every year in motor vehicle crashes. Alarmingly, the trend of fatal and serious injury crashes appears to be heading in the wrong direction. In 2021, the actual rate of fatalities exceeded the predicted rate. This worrisome trend prompts and necessitates the development of advanced and holistic approaches to determining the causes of a crash (particularly fatal and major injuries). These approaches range from analyzing problems from multiple perspectives, utilizing available data sources, and employing the most suitable tools and technologies …

Modeling And Validation Of Common-Mode Emission In Silicon Carbide Based Voltage Source Converters, Tianchen Li

Theses and Dissertations

Electromagnetic compatibility (EMC) issues have become one of the most difficult challenges in power converter designs. With the invention of wide bandgap (WBG) power semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) power MOSFETs, the power converter designs are provided with the potential to be significantly more power dense than older generation converters using silicone IGBTs. However, the majority of spectral contents of the switching waveforms are moved from the very-low-frequency (VLF, 3 kHz to 30 kHz) range to low-frequency and up to the very-high-frequency (VHF, 30 MHz to 300 MHz) range. Moreover, due to the design traits …

Development Of An Upper Limb Telerehabilitation System, Md Mahafuzur Rahaman Khan

Theses and Dissertations

Upper limb dysfunction (ULD) is common following a stroke, spinal cord injury, trauma, and occupational accidents. Post-stroke patients with ULD need long-term assistance from therapists for their rehabilitation, which generally occurs at the hospital or outpatient clinic. Travel and transportation are significant factors that prevent patients from receiving adequate therapy, often leading to long-term disability. A home-based rehabilitation device providing essential arm movement therapies can significantly ease this rehabilitation program. In this research, we developed an end-effector type Desktop-Mounted Rehabilitation Robot (DMRbot) with a minimum viable design to cover the full range of human upper limb (UL) workspace to provide …

Enhancement Of Energy Efficiency For Thermal Energy And Biomass Driven Applications, Osama Mansour Selim Elsayed

Theses and Dissertations

The importance of gas turbine blades is to convert the thermal energy into shaft work output, which makes the turbine blades are one of the critical components of the gas turbines. Besides the mechanical stresses caused by the centrifugal force and the fluid forces, the thermal stresses arise because of the temperature gradient within the blade materials. This paper aims to have a uniform circumferential temperature field at the combustor exit, consequently reducing the thermal stresses caused by the non-uniform temperature distribution along the turbine blade. The validation of the simulation results with the experiments showed an acceptable agreement with …

Freeze-Thaw Durability Evaluation Of Quarried Limestone Coarse Aggregates For Transportation Infrastructure Applications, Benjamin Matthew Stark

Theses and Dissertations

Aggregates are an important component of transportation infrastructure used as unbound base material and within Portland cement concrete (PCC) structures. In cold climate regions, seasonal freeze and thaw cycles cause damage to aggregate and impact pavements, bridges, and other transportation infrastructure performance. This research investigated Wisconsin quarried coarse aggregates for freeze-thaw durability as unbound aggregates as well as in PCC mixtures for pavement surface. A comprehensive laboratory testing program was conducted on 21 coarse aggregate samples consisting of calcareous and dolomitic limestone including sodium sulfate soundness, freeze-thaw testing, and absorption. Furthermore, three sources of these coarse aggregates were used to …

Adsorption Of Per- And Polyfluoroalkyl Substances On Functionalized Minerals: Effects Of Modifier Property And Mineral Structure, Qianqian Dong

Theses and Dissertations

ABSTRACTADSORPTION OF PER- AND POLYFLUOROALKYL SUBSTANCES ON FUNCTIONALIZED MINERALS: EFFECTS OF MODIFIER PROPERTY AND MINERAL STRUCTURE

by Qianqian Dong

The University of Wisconsin-Milwaukee, 2022Under the Supervision of Professor Yin Wang

Per-and polyfluoroalkyl substances (PFAS) are a large group of manmade chemicals widely used in various consumer and industrial products. The adverse effect of PFAS exposure includes bioaccumulation, organ damage and birth defects. Although the primary feedstock perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) has been phased out since the 2000s, PFAS are worldwide detectable in water bodies due to the historical production, accumulation and endless substitution of long-chain PFAS in …

Python-Based Analysis To Segment Bone And Soft Tissue In A Healing Callus, Roberto Lopez

Theses and Dissertations

The main objective of this study was to produce a Python script that would help facilitate the segmentation process of both bone and soft tissue. The proposed script, in tangent with ImageJ and Mimics, was successful in producing viable results when the bone and soft tissue sample was placed near hydroxyapatite (HA) phantoms during the image acquisition process. It was important to acquire both the HA phantoms and the sample within the same image sequence as the script functioned by analyzing the statistical distribution of the different HA regions to locate the most ideal thresholding ranges to determine the bone …

Properties Of Titanium Dioxide Nanoparticles Aquesous Dispersions Stabilized By Anionic Surfactants, Anita Vuchkovska

Theses and Dissertations

The stability of titanium dioxide nanoparticles dispersed in aqueous solutions with and without anionic surfactants was investigated as a function of phase separation (sedimentation), particle size at the age of 33 and 303 days, polydispersity at 33 and 303 days, and zeta potential. Mechanical energy in the form of homogenization or mixing with propeller blade mixer was used to wet out the titanium dioxide (TiO2) nanoparticles in the aqueous media and this process was evaluated for the capability of developing a stable dispersion. The ultrasonic waves were used as a second step to form stable dispersions. The research results indicated …

Interaction Between Test Structure And Shake Table Powered By Servo-Hydraulic Actuation, Rong Xu

Theses and Dissertations

This study focused on the interaction between shake tables and test structures. The shake tables are usually powered by servo-hydraulic actuation and under displacement control. The dynamic response of test structures may lower the ability of the shake table to produce motion at the natural frequency of the test structures. Models of the shake table at the Earthquake Engineering Research Center (EERC) and the new table at the Ningbo University of Technology (NBUT) were created in this study. Parametric analyses revealed that the table-structure interaction is affected by the dynamic response speed of the shake tables in addition to other …

Developing And Investigating A Fast And Controllable Prelithiation Method For Lithium-Ion Batteries, Huainan Qu

Theses and Dissertations

Prelithiation is to pre-load Li ions in a Li-ion electrode prior to a formation cycle. A chemical, roll-to-roll prelithiation method was developed in this thesis research. The method can be applied to different anode materials. The prelithiation compensated the initial loss of lithium during the formation cycles of a lithium-ion battery (LIB). Eventually, the initial coulombic efficiency (ICE) was significantly increased. In addition, the cyclability of a prelithiated battery was highly related to the quality of the solid electrolyte interface (SEI) on the anode surface. Electrochemical impedance spectroscopy (EIS) was a major technique to evaluate the difference of the SEI …

Applications Of Machine Learning In Medical Prognosis Using Electronic Medical Records, Farnaz Hajiahmadifoomani

Theses and Dissertations

Approximately 84 % of hospitals are adopting electronic medical records (EMR) In the United States. EMR is a vital resource to help clinicians diagnose the onset or predict the future condition of a specific disease. With machine learning advances, many research projects attempt to extract medically relevant and actionable data from massive EMR databases using machine learning algorithms. However, collecting patients' prognosis factors from Electronic EMR is challenging due to privacy, sensitivity, and confidentiality. In this study, we developed medical generative adversarial networks (GANs) to generate synthetic EMR prognosis factors using minimal information collected during routine care in specialized healthcare …

Nonreciprocal Electromagnetics Of Layered Media, Samaneh Pakniyat

Theses and Dissertations

In plasmonic systems, interaction of light and surface plasmons leads to excitation of surface plasmon polaritons (SPPs) carrying energy on the surface. In an isotropic plasmonic system, the SPPs optical response is reciprocal, which means that the forward and backward surface waves have identical propagation behaviors and SPPs refract when they encounter a discontinuity on the surface. In order to excite SPPs resilient to the surface disorders, the system reciprocity needs to be broken by different techniques such as applying an external magnetic bias. In this case, the plasmonic system becomes a gyrotropic medium. Recently, it has been shown that …

Experimental And Numerical Investigation Of The Effect Of Newly Tested Blades On The Aerodynamic Performance And Power Output Of A Horizontal Axis Wind Turbine, Alaa Sayed Mahmoud Hasan

Theses and Dissertations

There is no doubt that the effects of global warming are obvious for every human being on the Earth now. Therefore, the need to develop carbon dioxide-free sources of electricity is urgent. Wind Turbines are one of these most essential recently developed sources. For that reason, the University of Wisconsin-Milwaukee founded the wind tunnel lab., equipped with the state-of-the-art research tools, to take part in this procession.In chapter (3) of this thesis it is desired to investigate in detail the scenario that takes place behind a single wind turbine unit by focusing on three parameters; average axial wind velocity component, …

Nonreciprocal Surface Waves On Gyrotropic Interfaces, Alexander Martin Holmes

Theses and Dissertations

In this dissertation, the properties of highly nonreciprocal (unidirectional) surface waves guided along the interface between free-space and various 2D and 3D gyrotropic continua are investigated using analytic, numerical, and experimental methods. From a classical electromagnetics perspective, nonreciprocity in the dispersion of surface wave modes supported by the interface is achieved by breaking both time-reversal and space-inversion symmetries in the collective response of the waveguide, which consists of the two interfaced materials. More recently, however, a connection to momentum space topology via the bulk-edge correspondence principle has been made for gyrotropic continua, providing additional insights into the underlying physics that …

Triboinformatic Approaches For Surface Characterization: Tribological And Wetting Properties, Md Syam Hasan

Theses and Dissertations

Tribology is the study of surface roughness, adhesion, friction, wear, and lubrication of interacting solid surfaces in relative motion. In addition, wetting properties are very important for surface characterization. The combination of Tribology with Machine Learning (ML) and other data-centric methods is often called Triboinformatics. In this dissertation, triboinformatic methods are applied to the study of Aluminum (Al) composites, antimicrobial, and water-repellent metallic surfaces, and organic coatings.Al and its alloys are often preferred materials for aerospace and automotive applications due to their lightweight, high strength, corrosion resistance, and other desired material properties. However, Al exhibits high friction and wear rates …

Towards Environmental Sustainability Of Nanotechnology Through Improved Evaluations Of Impact And Risk To Aquatic Species: Cross-Species Comparisons From The Laboratory And Environmentally Realistic Exposure Scenarios In The Field, Becky J. Curtis

Theses and Dissertations

Engineered nanomaterials (ENMs) are utilized in a wide variety of applications and products, including everything from toothpaste and personal care products to industries such as aerospace, defense, medicine, electronics, and agriculture. Depending on the application, release of ENMs to the environment may occur through both unintentional and deliberate routes. High surface-area-to-volume ratios make ENMs more volatile than bulk counterparts, and their small size allows translocation within biological systems that would not be possible with larger materials. These and other characteristics make ENM-biological system interactions unpredictable, creating uncertainty about their potential risks to environmental health. The purpose of this research is …

Age-Of-Information-Aware Load Frequency Control And Stability Analysis, Dan Jiao

Theses and Dissertations

Nowadays, modern load frequency control (LFC) systems employ an open communication system, which causes information staleness inevitably to arise. This issue can degrade the regulation performance of LFC and even threaten stability. This thesis introduces age-of-information (AoI) into LFC to describe the information freshness at the control center. Unlike communication delay, AoI can provide real-time information state based on information update rate. In this thesis, a muti-area LFC-AoI model is built to evaluate the update rate effect on LFC performance. Then, an AoI-based stability criterion for discrete LFC systems is built. After that, the AoI margin is proposed and compared …

Potential Of Grid-Scale Pv And Storage Facilities To Participate In Capacity Markets, Nicholas Giovannetti

Theses and Dissertations

The recent FERC Order 841 has provided an opportunity for grid-scale PV and battery facilities to participate in the capacity market providing ancillary services. Order 841 combined with steadily decreasing PVand battery costs and increasing demand for renewable energy, gives high potential for a PV and battery facility to be economically viable. In this study, an analysis tool is developed as an auxiliary to the PV + Storage + Control + Grid (PSCG) simulation to estimate the megawatts (MW) of dispatchable capacity that can be reliably offered by a PV and storage facility. Limits are based on grid connection, power …

Stability Analysis And Parameters Design Of The Voltage Source Inverter With Lc Filter, Hongzhen Zhang

Theses and Dissertations

Voltage source inverters (VSI) are widely used in many applications. In this thesis, the stability of the LC-type single-phase off-grid inverter is investigated and the emphasis is focused on how to extend the effective damping region. The harmonics resonance is the main factor affecting the stability of the system. To deal with this problem, the stability of the system with passive damping is investigated. Aiming at the problem that passive damping methods introduce power loss, Active damping methods are proposed. Considering the system with traditional inductor current feedback active damping cannot be stable when resonance frequency is close to fs/6, …

Model Predictive Control For Grid Scale Pv And Battery, Sahithi Chatradi

Theses and Dissertations

Model Predictive Control (MPC) is a control technique that uses prediction data to optimize costs over a given predictive horizon. There are many papers that use this technique to optimize cost in a substantially loaded microgrid, but these techniques are not feasible for utility-scale PV+Storage facility. In this study, MPC is used to optimize the cost for a utility-scale PV+Storage facility, by adding a factor of a possible curtailment. The thesis also presents the various factors that the MPC has in that utility size grid. These factors include line losses, net yield, and curtailment.