Engineering Commons^™

A B-Spline-Based Generative Adversarial Network Model For Fast Interactive Airfoil Aerodynamic Optimization, Xiaosong Du, Ping He, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Airfoil aerodynamic optimization is of great importance in aircraft design; however, it relies on high-fidelity physics-based models that are computationally expensive to evaluate. In this work, we provide a methodology to reduce the computational cost for airfoil aerodynamic optimization. Firstly, we develop a B-spline based generative adversarial networks (BSplineGAN) parameterization method to automatically infer design space with sufficient shape variability. Secondly, we construct multi-layer neural network (MNN) surrogates for fast predictions on aerodynamic drag, lift, and pitching moment coefficients. The BSplineGAN has a relative error lower than 1% when fitting to UIUC database. Verification of MNN surrogates shows the root …

Applications Of Polynomial Chaos-Based Cokriging To Aerodynamic Design Optimization Benchmark Problems, Jethro Nagawkar, Leifur Leifsson, Xiaosong Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this work, the polynomial chaos-based Cokriging (PC-Cokriging) is applied to a benchmark aerodynamic design optimization problem. The aim is to perform fast design optimization using this multifidelity metamodel. Multifidelity metamodels use information at multiple levels of fidelity to make accurate and fast predictions. Higher amount of lower fidelity data can provide important information on the trends to a limited amount of high-fidelity (HF) data. The PC-Cokriging metamodel is a multivariate version of the polynomial chaos-based Kriging (PC-Kriging) metamodel and its construction is similar to Cokriging. It combines the advantages of the interpolation-based Kriging metamodel and the regression-based polynomial chaos …

The Effects And Analysis Of Implant Type And Surgical Approach In Total Hip Arthroplasty Dislocation Resistance, Brittany Marshall

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most successful orthopaedic surgeries performed, in which the hip joint is reconstructed to decrease pain and to improve the functionality to the joint. Although these surgeries are very successful, there still remain areas for improvement, such as failures due to instability and dislocation of the implanted joint. The purpose of this thesis is to investigate the effect of surgical entrance approach on dislocation, the effect of implant type, and the effect of capsule repair and closure. The need to quantify the resistance to dislocation is important in understanding the effect that each …

Transcatheter Mitral Valve Replacement: Structural And Hemodynamic Analysis, Saba Ravaghi

Electronic Theses and Dissertations

Transcatheter mitral valve replacement (TMVR) is being developed to become a substitute therapy for surgery in prohibitive or high surgical risk patients to treat severe mitral regurgitation. A limited number of TMVR systems are under clinical evaluation. However, transcatheter mitral valve (TMV) long-term durability and hemodynamic performance is not known. TMV durability and hemodynamics must match with that of surgical bioprostheses for potential commercialization of TMVR. Experimental and computational approaches were used to find the leaflets’ three-dimensional anisotropic mechanical properties in a transcatheter Edwards SAPIEN 3 valve and a surgical Carpentier-Edwards PERIMOUNT Magna mitral valve and finite element (FE) simulations …

Analysis Of Mechanical Deformation Eect On The Voltage Generation Of A Vertical Contact Mode Triboelectric Generator, Nabid Aunjum Hossain, Mir Jalil Razavi, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

One of the associated factors that controls the performance of a triboelectric generator (TEG) is the mechanical deformation of the dielectric layer. Therefore, a good contact model can be a prominent tool to find a more realistic and efficient way of determining the relationships between the contact and electrical output of the generator. In this study, experiments are conducted on a vertical contact mode triboelectric generator under an MTS machine. The open-circuit voltages are measured at different loads imposed by the MTS by controlling the cyclic displacement of the top tribo layer of the generator. A finite-element-based theoretical model is …

Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based …

Attainment Of Rigorous Thermodynamic Consistency And Surface Tension In Single-Component Pseudopotential Lattice Boltzmann Models Via A Customized Equation Of State, Cheng Peng, Luis F. Ayala, Zhicheng Wang, Orlando M. Ayala

Engineering Technology Faculty Publications

The lack of thermodynamic consistency is a well-recognized problem in the single-component pseudopotential lattice Boltzmann models which prevents them from replicating accurate liquid and vapor phase densities; i.e., current models remain unable to exactly match coexisting density values predicted by the associated thermodynamic model. Most of the previous efforts had attempted to solve this problem by introducing tuning parameters, whose determination required empirical trial and error until acceptable thermodynamic consistency was achieved. In this study, we show that the problem can be alternatively solved by properly designing customized equations of state (EOSs) that replace any cubic EOS of choice during …

Nsf S-Stem Project Update: A Pathway To Completion For Pursuing Engineering And Engineering Technology Degrees, Kim Bullington, Cynthia Tomovic, Vukica M. Jovanović, Anthony W. Dean, Rafael Landaeta

Engineering Technology Faculty Publications

This poster showcases the progress of students who are receiving scholarships from the National Science Foundation S-STEM project: A Pathway to Completion for Pursuing Engineering and Engineering Technology Degrees. Thus far, 20 academically high-achieving students who demonstrate financial need have participated in the project. Thirty-six scholarships have been awarded to date, in which a maximum of twelve scholarships are awarded per semester; some students have received scholarships multiple times. Students are from electrical engineering, computer engineering, mechanical engineering, civil engineering, civil engineering technology, and modeling and simulation majors. As part of this S-STEM project, students also receive academic support, mentorship …

Sensing And Measuring The Environment Workshop As Exposure To Engineering Technology For High School Students In A Summer Residential Camp, Vukica M. Jovanovic, Otilia Popescu, Murat Kuzlu, Mujde Erten-Unal, Balŝa Terzić, George Mcleod, Tysha Batts, Cynthia Tomovic

Engineering Technology Faculty Publications

Summer programs are the latest trend in extracurricular STEM education programs offered by universities. Efforts are made towards residential summer programs, which have the ability to expose students not only to specially designed STEM activities but to the university campus environment and student life, as well. These types of programs are expected to have better success in getting students engaged and to capture their interest in STEM fields. This paper presents one example of designing and implementing a summer residential workshop in order to expose high school students to the field of engineering technology, specifically to electrical circuits, electrical prototyping, …

Mems Biosensor For Water-Immersed Application, Kun-Lin Lee

Dissertations and Theses

Although many air-based sensing mechanisms exist, not all of them can be applied in the water-based environment. In order to obtain a cell-based biosensor, the sensing method needs to be reliable and repeatable in a liquid environment. Therefore, this study is focused on transforming existing air-based sensors to water-immersed applications. This study includes two types of sensors.

First, commercial quartz resonators are used to investigate live-cell activity in water-based toxic solutions. I perform toxicity tests using quartz crystal microbalance (QCM). The QCM used in the study has a resonant frequency of 10 MHz and consists of an AT-cut quartz crystal …

Influence Of Transdermal Current Flow In Tdcs-Induced Cutaneous Adverse Events, Niranjan Khadka

Dissertations and Theses

Significant contributors to the broad application of transcranial direct current stimulation (tDCS) are portability, ease-of-use, and tolerability; with adverse events limited to transient and mild cutaneous sensations (e.g. perception of burning, itching, and tingling) and erythema. However, the fundamental questions remain about the mechanism of transdermal current flow during transcranial electrical stimulation, including tDCS. Example of previously unexplained questions in tDCS include: 1) the relationship between tDCS-induced skin reddening (erythema) profile and local current density profile predicted by the model; 2) the source of burning sensation during tDCS and whether it is related to an actual skin heating; 3) the …

Macro - And Microstructure Evaluation And Field Applications Of Concrete With Recycled Glass Pozzolan, Marija Krstic

Dissertations and Theses

Concrete is the most used material in the world, second only to water. Conventional concrete is produced with Portland cement (PC). The production of cement is an energy intensive operation that has raised significant environmental concerns, since one ton of cement generates an equal ton of CO₂. In the USA about 90 million tons of cement are used annually, with 3 million tons used in New York. Most contemporary concrete applications for buildings and infrastructure use high-performance concrete (HPC) mixtures which are produced by replacing a percentage of cement with supplementary cementitious materials (SCMs), consisting mainly of fly-ash …

A Micromechanics Study On Ferroelectrics And Multiferroic Composites, Zhiming Hu

Dissertations and Theses

Two kinds of modern composites are studied in this thesis. One is ferroelectric materials, and the other is the multiferroic composites. Based upon the essential properties of these two types materials, several issues need to be considered in order to study their effective properties. For example, the microstructures of the system including the shape, size and the distribution; the phase connectivity; and the loading conditions will impact the results. First, we focus on the investigation of ferroelectrics and its composites. Based on the experimental observations, the nonlinear electromechanical coupling responses of ferroelectrics are strongly depending on the frequency of the …

Diffuse Damage Repair Mechanism In Bone, Leila Mehraban Alvandi

Dissertations and Theses

Bone microdamage is a result of fatigue, creep or ‘wear and tear’ caused by physiological activities and largely contributes to bone fragility. Bone, unlike engineered materials, has the ability to repair the microscopic cracking or microdamage through targeted, osteoclast-mediated bone remodeling. This capability is crucial for preservation of its structural integrity and quality; failure of the skeleton to effectively repair microdamage leads to accumulation of damage, which is one of the main contributors to bone fragility. Linear microcracks (50-100 µm) and diffuse damage (Dif.Dx) (sub-micron) are the two types of microdamage. Recent studies show that Dif.Dx repairs without bone remodeling, …

Characterization Of Bone Pathology In Sickle Cell Disease And Therapeutic Strategies, Mykel D. Green

Dissertations and Theses

Sickle cell disease (SCD) is a genetic hemoglobinopathy that has grown into a global health concern. While the advances in medical treatment and management of SCD during childhood have drastically improved the overall survival of children, the transition from pediatric to adult services is significantly inadequate in comparison. Life expectancies of patients with SCD in first world countries such as the United States are shortened to averages of 42 and 48 years for men and women, respectively. Despite the increasing number of people living with SCD, remarkably, few detailed studies have described the clinical course and complications of the disease …

Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro

Dissertations and Theses

Extreme heat events are becoming more frequent and intense in most large cities. Built-up surfaces also limit cooling mechanisms, leading to warmer conditions in cities, a phenomenon called the Urban Heat Island (UHI). This presents major challenges to reduce adverse health effects of hot weather, particularly in vulnerable populations like the elderly and low-income communities. Here we explore the overall impacts of increasing air conditioning (AC) system adoption in residences as an adaptive measure to reduce human health risks under heat waves, with New York City (NYC) as a case study. This study uses AC adoption data from the 2017 …

Investigation Of Asphaltene Adsorption At Liquid-Liquid And Liquid-Solid Interfaces, Fang Liu

Dissertations and Theses

Asphaltenes, as indigenous components in crude oils, are believed to play an important role in the petroleum production and processing industry. For example, asphaltene molecules can adsorb onto the water / oil interface like the amphiphiles and hinder water droplet coalescence, resulting in the stabilization of water-in-oil emulsions. Also, in the upstream production, depending on the temperature and pressure, asphaltenes can precipitate and deposit onto the reservoir rocks, the wellbores and the pipelines, leading to the change in reservoir rocks’ surface wettability and the blockage of the production facilities. Hence, it is crucial to understand the mechanism of asphaltenes adsorption …

Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas

Dissertations and Theses

Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …

Decision-Making In Reuse Of Highway Bridge Foundations, Ehssan Hoomaan

Dissertations and Theses

According to the 2019 National Bridge Inventory data from Federal Highway Administration, the average age of highway bridges in the U.S.A. is 45 years, with almost 43% of existing highway bridges being older than 50 years, and eight percent of all U.S. national highway bridges being in poor condition. Foundation and substructure of existing highway bridges (over land and water) may have significant functional values even after being under service for decades. Reusing an existing bridge foundation during the reconstruction of a bridge (e.g., major rehabilitation, retrofitting, replacement of superstructure and substructure, and addition/removal of a span) has the potential …

Attention Strongly Modulates Reliability Of Neural Response To Naturalistic Narrative Stimuli, Jason Ki

Dissertations and Theses

Attentional engagement is a major determinant of how effectively we gather information through our senses. Alongside the sheer growth in the amount and variety of information content we are presented with through modern media, there is increased variability in the degree to which we ‘absorb’ that information. Traditional research on attention has illuminated the basic principles of sensory selection to isolated features or locations, but it provides little insight into the neural underpinnings of our attentional engagement with modern naturalistic content. Here, we show in human subjects that the reliability of an individual's neural responses with respect to a larger …

Recuperation Of Regenerative Braking Energy In Electric Rail Transit Systems, Mahdiyeh Khodaparastan

Dissertations and Theses

Electric rail transit systems are large consumers of energy. In trains with regenerative braking capability, a fraction of the energy used to power a train is regenerated during braking. This regenerated energy, if not properly captured, is typically dumped in the form of heat to avoid overvoltage. Finding a way to recuperate regenerative braking energy can result in substantial economic as well as technical benefits. Regenerative braking energy can be effectively recuperated using wayside energy storage, reversible substations, or hybrid storage/reversible substation systems. In this research study, we compare these recuperation techniques and investigate their application in New York City …

Influence Graphs For Modeling Of Cascading Failures In Electric Distribution Networks, Muhammad S. Bhatti

Dissertations and Theses

Power Grids are one of the most intricate systems and greatly affect economic, political, and social aspects of contemporary life. A well-operated power system consists of many control devices and protection methods to prevent the interruption of power to consumers. However, such systems are highly vulnerable to severe events; for instance, natural disasters, cyber-attacks, mal-function of control devices, etc. The occurrence of these odd events may lead to cascading failures, which are prominent contributors to blackouts.

This paper focuses on the development of a cascade model in a distribution network using Newton-Raphson’s power flow method to study the impact of …

Toward Closing The Urban Surface Energy Balance Using Satellite Remote Sensing, Joshua Hrisko

Dissertations and Theses

The energy exchanges at the Earth’s surface are responsible for many of the processes that govern weather, climate, human health, and energy use. This exchange, commonly known as the surface energy balance (SEB), determines the near-surface thermodynamic state by partitioning the available energy into surface fluxes. The net all-wave radiation is often the primary energy source, while the heat storage and sensible and latent heat fluxes account for the majority of energy distributed elsewhere. While the SEB of various natural environments(trees, crops, soils) has been well-observed and modeled, the urban surface energy balance remains elusive. This is due to the …

Effects Of Weak Electric Fields On Long-Term Synaptic Plasticity, Gregory Kronberg

Dissertations and Theses

Transcranial direct current stimulation (tDCS) is a technique where a weak direct electrical current is applied to the scalp with the goal of stimulating the brain. There is tremendous interest in the use of tDCS for treating brain disorders and improving brain function. However, the effects of tDCS have been highly variable across studies, leading to a debate over its efficacy. A major challenge is therefore to design tDCS protocols that yield predictable effects, which will require a better understanding of its basic mechanisms of action. One commonly discussed mechanism is that tDCS may alter synaptic plasticity, but the biophysics …

Dynamics And Phase Behavior Of Mixed Antibody-Excipient Adsorption At An Air/Water Interface, Ankit D. Kanthe

Dissertations and Theses

Monoclonal antibodies (mAbs) have become a leading candidate for oncological therapeutics due to their unparalleled selectivity. Monoclonal antibodies are amphiphilic, containing polar and nonpolar amino acid residues on their biomolecular surfaces. Their amphiphilic nature drives mAbs to strongly adsorb to air/water interfaces. Interfacial adsorption presents a central problem to the production and use of antibody-based pharmaceuticals. Air/water interfaces are frequently generated during the manufacture (filtration and chromatography) and production (freezing, thawing, filtration and filling) of the drug product. Moreover, air/water interfaces are present during the storage, transportation and administration of the therapeutics. When an air/water interface is created, the antibodies …

Computational Fluid Dynamics Simulation Of Rain-Wind-Induced Vibration Of Stay Cables, Hongfan Wang

Dissertations and Theses

Due to the large amplitude, frequent occurrence and severe consequences, the rain-wind induced vibration (RWIV) of stay cables in cable-stayed bridges has been investigated extensively by researchers around the world. However, the underlying excitation mechanism is still unclear. Recently, computational fluid dynamics (CFD) simulation has been widely applied in the research on structure vibrations due to dynamic wind loads, with great potential as an alternative tool for wind tunnel testing. It has also been adopted to investigate the RWIV, but only a few studies have been conducted so far. Furthermore, most of the CFD simulations reported in literatures are two-dimensional, …

Unique Image Representation As A Tensor, Bharat Rosanlall

Dissertations and Theses

This thesis presents a two dimensional orthonormal transform that represents an image as coefficients in 4 independent channels. The salient feature of these coefficients is that they contain complete position spatial frequency information about the image, in a sense that the original image can be reconstructed from these coefficients with negligible error. These coefficients can be used in various machine learning, AI , and other tasks where data features are used. Popular convolutional layer used in various neural networks reduces information and can not reconstruct original image. In this thesis , we present several examples where these coefficients are used …

Adaptive Effort Classifiers: A System Design For Partitioned Edge/Cloud Inference, Divya Sankar

Dissertations and Theses

The massive growth in availability of real-world data from connected devices and the overwhelming success of Deep Neural Networks (DNNs) in many ArtificialIntelligence (AI) tasks have enabled AI-based applications and services to become commonplace across the spectrum of computing devices from edge/Internet-of-Things (IoT) devices to data centers and the cloud. However, DNNs incur high computational cost (compute operations, memory footprint and bandwidth),which far outstrip the capabilities of modern computing platforms. Therefore improving the computational efficiency of DNNs wide-spread commercial deployment and success.In this thesis, we address the computational efficiency challenge in the context ofAI inference applications executing on edge/cloud systems, …

Using Statistical Learning Approaches To Understand Trends And Variability Of Tornadoes Across The Continental United States, Niloufar Nouri

Dissertations and Theses

The annual frequency of tornadoes during 1950-2018 across the major tornado-impacted states were examined and modeled using anthropogenic and large-scale climate covariates in a hierarchical Bayesian inference framework. Anthropogenic factors include increases in population density and better detection systems since the mid-1990s. Large-scale climate variables include El Niño Southern Oscillation (ENSO), Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), Arctic Oscillation (AO), and Atlantic Multi-decadal Oscillation (AMO). The model provides a robust way of estimating the response coefficients by considering pooling of information across groups of states that belong to Tornado Alley, Dixie Alley, and Other …

Motion Of Janus And Patchy Particles Near Various Boundaries, Zohreh Jalilvand

Dissertations and Theses

Colloidal particles with anisotropic surface properties are an emergent class of novel materials that have been indicated to possess a remarkable potential to still be fully exploited. Among anisotropic colloids, Janus and patchy particles with different compositions and functionalities recently have drawn significant attention in the field of colloid science. They are known as promising candidates to address challenges in various fields such as emulsion stabilization, oil recovery, drug delivery, biosensors and environmental remediation. A majority of the envisioned applications require Janus and patchy particles to operate near boundaries, i.e., a wall or a fluid/liquid interface, which significantly affect the …