Engineering Commons^™

Mo6s8-Based Single-Metal-Atom Catalysts For Methanol Synthesis From Steam Reforming Of Methane, H. T. Zhang Zhang

Dissertations, Master's Theses and Master's Reports

The surge of methane as the major component of natural gas and a dominant greenhouse gas calls for the development of efficient strategy to convert it into valuable liquid chemicals such as methanol. However, the current industrial method for methanol synthesis, which consists of the stream reforming of methane (SRM) to syngas and the followed reaction of syngas to methanol, is rather energy-intensive. Direct conversion of methane into methanol (DMTM) is highly desirable in terms of energy efficiency and economy. DMTM with water as oxidant, i.e. SRM to methanol, is a promising solution but the development highly efficient and selective …

Buckling Load Study On Pop Nut (Rivet) Using Finite Element Analysis, Saurabh Shankar Shegokar

Dissertations, Master's Theses and Master's Reports

This study highlights the material behavior in riveting operation that includes buckling load analysis using ABAQUS. Finite Element Analysis is used to find the buckling load vs. Displacement results and validated with the results obtained in physical testing of rivet (POP Nut). A mesh sensitivity study is performed using ABAQUS to understand the optimum mesh size for this analysis. An axisymmetric model with contact properties is created and simulated to reduce the simulation time using ABAQUS. The results obtained through Finite Element Analysis show a good resemblance with the testing results. Design changes were suggested to achieve better results that …

Radio Frequency Studies Of Soot Loading And Ammonia Storage On A Diesel Particulate Filter With A Scr Catalyst Coating, Shreyans Sethia

Dissertations, Master's Theses and Master's Reports

The radio frequency (RF) measurement technique has been shown to be a viable method for measurement of the amount of soot loaded onto DPF’s ^[1] and the amount of NH₃ stored on SCR catalysts ^[2]. In one of the configurations, a microwave resonant cavity is formed by the metal can encasing the enclosed catalyst. Two metal probes acting as antennas are placed on either side of the catalyst. Power transmitted between the antennas is monitored as the frequency of the signal is swept. At certain frequencies, resonance is achieved. Measurements of the resonance frequencies, amplitude at resonance, and …

Artificial Synthetic Scaffolds For Tissue Engineering Application Emphasizing The Role Of Biophysical Cues, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

The mechanotransduction of cells is the intrinsic ability of cells to convert the mechanical signals provided by the surrounding matrix and other cells into biochemical signals that affect several distinct processes such as tumorigenesis, wound healing, and organ formation. The use of biomaterials as an artificial scaffold for cell attachment, differentiation and proliferation provides a tool to modulate and understand the mechanotransduction pathways, develop better in vitro models and clinical remedies. The effect of topographical cues and stiffness was investigated in fibroblasts using polycaprolactone (PCL)- Polyaniline (PANI) based scaffolds that were fabricated using a self-assembly method and electrospinning. Through this …

Establishment Of Cyber-Physical Correlation And Verification Based On Attack Scenarios In Power Substations, Koji Yamashita

Dissertations, Master's Theses and Master's Reports

Insurance businesses for the cyberworld are an evolving opportunity. However, a quantitative model in today's security technologies may not be established. Besides, a generalized methodology to assess the systematic risks remains underdeveloped. There has been a technical challenge to capture intrusion risks of the cyber-physical system, including estimating the impact of the potential cascaded events initiated by the hacker's malicious actions.

This dissertation attempts to integrate both modeling aspects: 1) steady-state probabilities for the Internet protocol-based substation switching attack events based on hypothetical cyberattacks, 2) potential electricity losses. The phenomenon of sequential attacks can be characterized using a time-domain simulation …

The Study Of Chemical Induced Polyolefin-Based Ion Exchange Membrane For Electrodialysis Application, Di Huang

Dissertations, Master's Theses and Master's Reports

High-performance ion exchange membranes with high ion exchange capacity (IEC), excellent mechanical properties, lower membrane resistance and superior ions conductivity were developed with chemical-induced polymerization in this work. Through a series of synthesizing experiments, structure characterization and properties testing for polyolefin-based cation exchange membrane (CEM) and anion exchange membrane (AEM), LDPE proved to be an optimized backbone material. The CEM with 57.5% styrene, 38.4% LDPE, 3% crosslinking degree and 1% initiator addition yield the highest IEC value (1.72 mol/g) and moderate burst strength. The 10% addition of styrene was found to enhance IEC of 57% to AEM. However, continually increase …

Comparative Evaluation Of Carbon Reinforced Polyetherketone Acetabular Cup Using Finite Element Analysis, A. Abdal, Rafiqul Noorani, G. Cha

Mechanical Engineering Faculty Works

Background: Patients suffering from osteoarthritis undergo surgery to replace hip joints with hip prosthesis implants. Today most acetabular cups of hip prostheses are made of Ultra-High-Molecular-Weight-Polyethylene. However, these materials acting as acetabular cups of the implant have been recalled since patients have been feeling uncomfortable and abstained from physical activities. A newly introduced material, 30% Carbon Reinforced Polyetherketone, possess better isotropic mechanical properties and lower wear rates.

Objective: The research aims to compare the von-Mises stresses and deformation in static and dynamic loading of Ultra-High Molecular-Weight-Polyethylene to 30% Reinforced Carbon Fiber Polyetherketone using Finite Element Analysis.

Material and Methods: An …

A Progressive Output Strategy For Real-Time Feedback Control Systems, Qiming Zou, Ling Wang, Jie Liu, Yingtao Jiang

Electrical & Computer Engineering Faculty Research

The real-time requirements imposed on a feedback control system are often hard to be met, as the controller spends a disproportionately large amount of time waiting for a control cycle to reach its final state. When such a final state is established, multiple tasks have to be prioritized and launched altogether simultaneously, and the system is given an extremely short time window to generate its output. This huge gap between the wait and action times, perceived as a load unbalancing problem, hinders a control decision to be made in real time. To address this challenging problem, in this paper, we …

Dynamic Allocation/Reallocation Of Dark Cores In Many-Core Systems For Improved System Performance, Xingxing Huang, Xiaohang Wang, Yingtao Jiang, Amit Kumar Singh, Mei Yang

Electrical & Computer Engineering Faculty Research

A significant number of processing cores in any many-core systems nowadays and likely in the future have to be switched off or forced to be idle to become dark cores, in light of ever increasing power density and chip temperature. Although these dark cores cannot make direct contributions to the chip's throughput, they can still be allocated to applications currently running in the system for the sole purpose of heat dissipation enabled by the temperature gradient between the active and dark cores. However, allocating dark cores to applications tends to add extra waiting time to applications yet to be launched, …

Instructor Activity Recognition Using Smartwatch And Smartphone Sensors, Zayed Uddin Chowdhury

College of Graduate Studies: Theses & Dissertations

During a classroom session, an instructor performs several activities, such as writing on the board, speaking to the students, gestures to explain a concept. A record of the time spent in each of these activities could be valuable information for the instructors to virtually observe their own style of instruction. It can help in identifying activities that engage the students more, thereby enhancing teaching effectiveness and efficiency. In this work, we present a preliminary study on profiling multiple activities of an instructor in the classroom using smartwatch and smartphone sensor data. We use 2 benchmark datasets to test out the …

Phase-Locked Loop Control In Low-Inertia Grid-Connected Voltage-Source Converters, Ifechukwude Gideon Odogwu

College of Graduate Studies: Theses & Dissertations

As the integration of renewable energy on the grid increases, the number of voltage-source converters (VSC) installed also does. VSC controls both switch turn-on and turn-off, allowing a dc voltage source to be switched between phases. For the converter to accurately synchronize with the grid, a phase-locked loop (PLL) is used for the frequency measurements of the grid. However, the implementation of PLL with measurement delay introduces harmonics, noise, high frequency, and voltage oscillation to the system due to its dynamics. The dynamics introduced to the grid can be ignored under stiff grid conditions, but power from renewable sources decreases …

Remote Communication In Wilderness Search And Rescue: Implications For The Design Of Emergency Distributed-Collaboration Tools For Network-Sparse Environments, Brennan Jones, Anthony Tang, Carman Neustaedter

Research Collection School Of Computing and Information Systems

Wilderness search and rescue (WSAR) requires careful communication between workers in different locations. To understand the contexts from which WSAR workers communicate and the challenges they face, we interviewed WSAR workers and observed a mock-WSAR scenario. Our findings illustrate that WSAR workers face challenges in maintaining a shared mental model. This is primarily done through distributed communication using two-way radios and cell phones for text and photo messaging; yet both implicit and explicit communication suffer. WSAR workers send messages for various reasons and share different types of information with varying levels of urgency. This warrants the use of multiple communication …

Gold/Qds-Embedded-Ceria Nanoparticles: Optical Fluorescence Enhancement As A Quenching Sensor, Nader Shehata, Effat Samir, Ishac Kandas

Electrical & Computer Engineering Faculty Publications

This work focuses on improving the fluorescence intensity of cerium oxide (ceria) nanoparticles (NPs) through added plasmonic nanostructures. Ceria nanoparticles are fluorescent nanostructures which can emit visible fluorescence emissions under violet excitation. Here, we investigated different added plasmonic nanostructures, such as gold nanoparticles (Au NPs) and Cadmium sulfide/selenide quantum dots (CdS/CdSe QDs), to check the enhancement of fluorescence intensity emissions caused by ceria NPs. Different plasmonic resonances of both aforementioned nanostructures have been selected to develop optical coupling with both fluorescence excitation and emission wavelengths of ceria. In addition, different additions whether in-situ or post-synthesis have been investigated. We found …

Prefrontal High Gamma In Ecog Tags Periodicity Of Musical Rhythms In Perception And Imagination, S.A. Herff, C. Herff, A. J. Milne, Garett D. Johnson, J. J. Shih, D. J. Krusienski

Electrical & Computer Engineering Faculty Publications

Rhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in …

Degradation Mechanism Due To Water Ingress Effect On The Top Contact Of Cu(In,Ga)Se2 Solar Cells, Deewakar Poudel, Shankar Karki, Benjamin Belfore, Grace Rajan, Sushma Swaraj Atluri, Sina Soltanmohammad, Angus Rockett, Sylvain Marsillac

Electrical & Computer Engineering Faculty Publications

The impact of moisture ingress on the surface of copper indium gallium diselenide (CIGS) solar cells was studied. While industry-scale modules are encapsulated in specialized polymers and glass, over time, the glass can break and the encapsulant can degrade. During such conditions, water can potentially degrade the interior layers and decrease performance. The first layer the water will come in contact with is the transparent conductive oxide (TCO) layer. To simulate the impact of this moisture ingress, complete devices were immersed in deionized water. To identify the potential sources of degradation, a common window layer for CIGS devices—a bilayer of …

A New Method Of Detecting And Interrupting High Impedance Faults By Specifying The Z-Source Breaker In Dc Power Networks, Sagar Bhatta, Ruiyun Fu, Yucheng Zhang

Electrical & Computer Engineering Faculty Publications

High impedance faults (HIFs) that cause a relatively smaller current magnitude compared to the traditional low impedance faults are not easily detectable but can cause an extreme threat to electric apparatus and system operation. This paper introduces a new method of detecting and interrupting HIFs in DC power networks by specifying Z-source circuit breakers (ZCBs). The ZCB is a protective device for high power DC branches, with the capabilities of protecting bidirectional power flow and automatic/controllable turnoff function. In this new method, the operational mode of ZCB (i.e., either the detection mode or interruption mode) can be specified. Beyond previous …

Superconducting Radio-Frequency Cavity Fault Classification Using Machine Learning At Jefferson Laboratory, Chris Tennant, Adam Carpenter, Tom Powers, Anna Shabalina Solopova, Lasitha Vidyaratne, Khan Iftekharuddin

Electrical & Computer Engineering Faculty Publications

We report on the development of machine learning models for classifying C100 superconducting radio-frequency (SRF) cavity faults in the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. CEBAF is a continuous-wave recirculating linac utilizing 418 SRF cavities to accelerate electrons up to 12 GeV through five passes. Of these, 96 cavities (12 cryomodules) are designed with a digital low-level rf system configured such that a cavity fault triggers waveform recordings of 17 rf signals for each of the eight cavities in the cryomodule. Subject matter experts are able to analyze the collected time-series data and identify which of the …

Introducing Coding Into Teacher Education: An Interdisciplinary Robotics Experience For Education And Engineering Students, Jennifer Kidd, Krishna Kaipa, Sam Sacks, Lilian Almeida

Teaching & Learning Faculty Publications

Despite nationwide mandates to integrate computer science into P-6 curriculum, most P-6 preservice teachers (PSTs) are not exposed to coding or computational thinking during their professional preparation, and are unprepared to teach these topics. This study, conducted as a part of an NSF-funded project, explores a teacher preparation model designed to increase PSTs’ coding knowledge and coding self-efficacy. PSTs in an educational technology course partnered with engineering undergraduates (EUs) in a computational methods course and worked side-by-side on robotics activities to develop skill and confidence with basic programming concepts and block coding. Students utilized experience gained from these interdisciplinary partnerships …

"Zooming In" On Robotics During Covid-19: A Preservice Teacher, An Engineering Student, And A 5th Grader Engineer Robotic Flowers Via Zoom, Jennifer Kidd, Krishna Kaipa, Kristie Gutierrez, Pilar Pazos, Orlando Ayala, Stacie Ringleb

Teaching & Learning Faculty Publications

The COVID-19 induced school shutdown dramatically decreased students’ hands-on STEM learning opportunities. An NSF-funded program partnering preservice teachers and undergraduate engineering students to teach robotics to fifth graders was adapted to a virtual format via Zoom. A case study intimately explored one team’s experience as they engineered bio-inspired robots over five weekly sessions. Zoom recordings, written reflections, and lesson slides were analyzed to describe how the virtual context shaped the lesson and influenced the preservice teacher’s experience. All three participants successfully engineered a robotic flower indicating hands-on robotics instruction is feasible in an online format. The virtual context increased the …

High Tech, High Risk: Tech Ethics Lessons For The Covid-19 Pandemic Response, Emanuel Moss, Jacob Metcalf

Publications and Research

The COVID-19 pandemic has, in a matter of a few short months, drastically reshaped society around the world. Because of the growing perception of machine learning as a technology capable of addressing large problems at scale, machine learning applications have been seen as desirable interventions in mitigating the risks of the pandemic disease. However, machine learning, like many tools of technocratic governance, is deeply implicated in the social production and distribution of risk and the role of machine learning in the production of risk must be considered as engineers and other technologists develop tools for the current crisis. This paper …

Liana Abundance And Diversity Increase With Rainfall Seasonality Along A Precipitation Gradient In Panama, Anthony J. Parolari, Kassandra Paul, Aaron H. Griffing, Richard Condit, Ronaldo Perez, Salomón Aguilar, Stefan A. Schnitzer

Civil and Environmental Engineering Faculty Research and Publications

In tropical regions, rainfall gradients often explain the abundance and distribution of plant species. For example, many tree and liana species adapted to seasonal drought are more abundant and diverse in seasonally-dry forests, characterized by long periods of seasonal water deficit. Mean annual precipitation (MAP) is commonly used to explain plant distributions across climate gradients. However, the relationship between MAP and plant distribution is often weak, raising the question of whether other seasonal precipitation patterns better explain plant distributions in seasonally-dry forests. In this study, we examine the relationship between liana abundance and multiple metrics of seasonal and annual rainfall …

Optimal Feature Selection For Learning-Based Algorithms For Sentiment Classification, Zhaoxia Wang, Zhiping Lin

Research Collection School Of Computing and Information Systems

Sentiment classification is an important branch of cognitive computation—thus the further studies of properties of sentiment analysis is important. Sentiment classification on text data has been an active topic for the last two decades and learning-based methods are very popular and widely used in various applications. For learning-based methods, a lot of enhanced technical strategies have been used to improve the performance of the methods. Feature selection is one of these strategies and it has been studied by many researchers. However, an existing unsolved difficult problem is the choice of a suitable number of features for obtaining the best sentiment …

Evaluation And Inter-Comparison Of Satellite Precipitation Estimations For Extreme Flood Events In Peninsular Malaysia, Zhen Xiang Eugene Soo

Student Works (2020-2029)

Satellite precipitation products (SPP) have been useful in any hydrological applications as their extensive spatial coverage and finer space and time resolutions. However, these satellite estimations exhibit large systematic and random errors which may cause large uncertainties in any hydrological applications. In this study, three advanced satellite precipitation products, i.e. CMORPH, TRMM 3B42V7, and PERSIANN are utilized in conjunction with the ground observation to investigate their performance in detecting rain, capturing storms and rainfall pattern during extreme flood events. This study evaluates and compares the capability of the SPP by focusing on the 2014-2015 northeast monsoon extreme flood events. Three …

Speckle-Noise Reduction In Knee Articular Cartilage Ultrasound Image Using Anisotropic Diffusion, Ali Muhammad Shoaib

Student Works (2020-2029)

Knee arthritis is the most common type of arthritis which effects the people and may cause severe pain to the patient and can lead to joint effusion. Ultrasound (US) imaging is an appropriate and consistent substitute for other imaging techniques like magnetic resonance imaging or X-rays in the investigation or screening of knee injury. Nevertheless, one of the major problems in US images which make the analysis of these images hard is the presence of speckle noise. For the reduction of speckle noise, the performance of the anisotropic method is found much better over other approaches. In removing the speckle …

Investigation On The Mechanical Properties And Microstructure Analysis Of Micro-Resistance Spot Welding Between Stainless Steel 316l And Tl-6al-4v, Mohd Mansor Muhammad Safwan

Student Works (2020-2029)

In this study, ASS 316L and Ti-6Al-4V were welded together by micro-resistance spot welding (μRSW) at different combinations of welding parameters using specifically design electrode geometry in order to acquire the optimal combination of welding parameters. The welded joint were subjected to tensile shear strength test to determine the influence of welding current, welding time, welding force and different design of elctrode tip on the mechanical properties and the strength of the welded joint. The experiment was conducted by using full factorial design of experiment (DoE) with L27 orthogonal array and utilizing the analysis of variance (ANOVA) to obtain the …

Design And Development Of Fiber Bragg Grating Sensor For Detecting Of Hydrogen Gas In Transformer Oil, Mohd Raffi Samsudin

Student Works (2020-2029)

Hermetically sealed oil-immersed transformers are the key to electricity distribution networks. They are also one of the most expensive facilities in the electricity supply network. Immediate replacement is expected for this type of transformer upon failure because it is directly connected to the customer. Transformer oil acts as insulation, coolant and condition indicator. To date, there is no economical real-time monitoring system available to monitor the transformer oil condition. Therefore, there is a need to develop a cheap, non-intrusive and non-electrical sensor to monitor the health of the transformer by measuring the amount of dissolved hydrogen gas in oil, which …

Investigation Of Mental Workload And Job Satisfaction Among Officer Workers At A Selected Electronic Company, Md Ali Nor Qistina

Student Works (2020-2029)

This study investigated the level of mental workload and job satisfaction among office workers at a selected electronic company in Subang Jaya. 103 professional workers from various departments comprising 54 males and 49 females participated in this study. DASS-21, Carga Mental Questionnaire, and Job Satisfaction Survey were used to gather data from the participants. Socio-demographic data were collected from participants too. The results showed mental workloads level is low among the workers while the level of job satisfaction is average. However, the level of stress among female workers is mild which is slightly higher than males. There are significant correlations …

Development Of Bio-Based 2t Engine Oil In Marine Engine Application / Babooraman Shanmuganathan, Babooraman Shanmuganathan

Student Works (2020-2029)

Two-storke enginers are simple and lightweight two-cycle spark ignition engine with no oil sump is needed. The use of bio-based lubricants was analyzed to replace commercial mineral and synthetic-based lubricants. Lubricants were prepared by mixing three components of oil which comprise of base oil, additives, and solvent. In this research, four samples of base oil had been prepared with a different weight ratio of the PFAD-NPGester and Type II mineral. Then each of the simples were added with a similiar weight ratio of additives and solvent. A commercial lubricant was used as areference lubricant to be compared with samples prepared. …

Ultra-Wideband Power Amplifier Design For Large Signal Application, Ragavan Krishnamoorthy

Student Works (2020-2029)

Broadband power amplifier design has become one of the most critical enabling block in today’s wireless communication technology. Numerous research efforts have been carried out throughout the years to establish high efficiency over wideband RF transmitter. This research work presents two approaches in achieving ultra-broadband power amplifier for RF transmitter. Firstly, a new technique for the design of ultra-broadband RF power amplifier is introduced, in which a combination of the reactance compensation and third-harmonic tuning are adopted. The design goal is to achieve 40 dBm (10W) output power across a wide frequency bandwidth operation. Theoretical design equations were developed to …

Automated Disruption Assistance In Brazil, Christian Gruber Delamare, Douglas Cabrera Lopes, Patrice Ramos, Raioni De Oliveira Santos, Leila Halawi

Publications

During the last decade, commercial aviation in Brazil has grown significantly, overcoming the number of 100 million passengers per year. The full operation represents a challenge for the air carriers, especially during flight disruptions. Besides the re-accommodation of the passengers into other flights, under certain circumstances, the ANAC 400 resolution requires the airlines to provide a series of material assistance. Meal, transport, and hotel make part of the exigences stated by the ANAC 400. Our study aims to analyze the current process that is mainly manual and propose to automatize several steps through a self-service solution. The researchers verified the …