Engineering Commons^™

Disinfection By-Product Precursor Removal By Biochar Derived From Agricultural Waste, Sorawit Ritthisoonthorn, Yuvarat Ngernyen, Lippakorn Songnangrong, Warodom Rattanaboonta, Watsa Khongnakorn, Panitan Jutaporn

Applied Environmental Research

Biochar made from agricultural waste products can be used as a low-cost adsorbent targeting dissolved organic matter (DOM). In water treatment plant (WTP), DOM reacts with chlorine-based disinfectant and forms carcinogenic disinfection by-products. The objective of this study was to investigate the applicability of bamboo biochar derived from wood vinegar production waste as an adsorbent for DOM removal and subsequently trihalomethane formation potential (THM-FP) reduction. Raw biochar (BCRaw) and 800°C post-heated biochar (BC800) was tested for its surface characteristics including scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer, Emmett and Teller analysis. The post-pyrolysis treatment increased the surface area …

Spatial Distribution Of Bioavailable Metal Concentrations And Total Metal Concentration-Depth Relationship Along The Sediment Profile Within Phuket Bay, Pensiri Akkajit, Danai Tipmanee, Kaimook Jaileak

Applied Environmental Research

Heavy metals in coastal sediments can adversely affect human health and the environment. The distribution and metal bioavailability of Pb and Zn in 21 sediment samples collected from Phuket Bay, Phuket, Thailand using the first-two steps of sequential extraction proposed by the Standards, Measurements and Testing programme (known as BCR) was determined. The results showed that Pb formed weak complexes contributing up to 11.2% to 33% of its total concentration (1.7 to 7.5 mg kg-1) in the first fraction (BCR1), while Zn in the BCR1 fraction ranged from 4.9% to 9.9%. The results suggest that Pb could easily enter the …

Identification Of Saline Water Intrusion Using Integrated Geoelectrical Method In The Coastal Aquifer Of Holo-Quaternary Formation, Lampung Bay, Rustadi -, Agus Setiawan, I Gede Boy Darmawan, Suharno -, Nandi Haerudin

Applied Environmental Research

Increased groundwater extraction from aquifers in Holo-Quaternary rock formations in Lampung Bay has caused saltwater intrusion. This indication appears in several community wells and can spread further inland. Therefore, this study aims to identify the distribution of areas exposed to saline water and the boundaries of areas that have not, especially in the Holo-Quaternary Formation. This research uses the geoelectric method integrated with salinity data and the Soil Penetration Test (SPT) analysis at four drilling points. A total of 4 lines of Electrical Resistivity Tomography (ERT) and 8 points of Vertical Electrical Sounding (VES) have been acquired with a Schlumberger …

Raman Spectroscopy Reveals Phenotype Switches In Breast Cancer Metastasis, Santosh Kumar Paidi, Joel Rodriguez Troncoso, Mason G. Harper, Zhenhui Liu, Khue G. Nguyen, Sruthi Ravindranathan, Lisa Rebello, David E. Lee, Jesse D. Ivers, David A. Zaharoff, Narasimhan Rajaram, Ishan Barman

Biomedical Engineering Faculty Publications and Presentations

The accurate analytical characterization of metastatic phenotype at primary tumor diagnosis and its evolution with time are critical for controlling metastatic progression of cancer. Here, we report a label-free optical strategy using Raman spectroscopy and machine learning to identify distinct metastatic phenotypes observed in tumors formed by isogenic murine breast cancer cell lines of progressively increasing metastatic propensities. Methods: We employed the 4T1 isogenic panel of murine breast cancer cells to grow tumors of varying metastatic potential and acquired label-free spectra using a fiber probe-based portable Raman spectroscopy system. We used MCR-ALS and random forests classifiers to identify putative spectral …

Modeling, Simulation, And Hardware-In-The-Loop Implementation Of Distributed Voltage Control In Power Systems With Renewable Energy Sources, Ali Dehghan Banadaki

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation develops and analyzes distributed controllers for power systems with renewable energy sources. A comprehensive state space modeling of voltage source inverters (VSIs) is developed specifically to address the secondary voltage control. This model can be used for simulation and control design. Unlike frequency, voltage is a local phenomenon, meaning that it cannot be controlled from a far distance. Therefore, a voltage zoning matrix that relates the sensitivity of the loads to the sources is proposed. The secondary voltage control is designed by applying the eigenvalue decomposition of the voltage zoning matrix to obtain the reference generators voltages. The …

Experimental And Design Evaluation Of Multi-Bolted Gfrp Joints, Amir Hossein Houshmandyar

Graduate Theses, Dissertations, and Problem Reports (ETD)

For infrastructure system implementation, high strength/stiffness to self-weight ratio, corrosion resistance and ease of fabrication are just a few of the many advantages of pultruded fiber reinforced polymer (PFRP) composites over traditional construction materials. However, challenges of engineered FRP materials are addressed via continuous updating of design codes. For example, the anisotropic nature of FRP composite materials includes different mechanical properties in different directions (pull or longitudinal direction vs. transverse to pull direction) of a structural member, resulting in design complexities over isotropic materials. Typically, infrastructure systems are built by bolting FRP structural members because of certain advantages of bolted …

Stormwater Runoff Response Under Changing Climate And Land Uses Across Gradients Of Inland And Coastal Urban-Natural Basin, Mahmood Khan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Climatic variability has caused significant shifts in the magnitude, frequency and spatiotemporal distribution of precipitation, generating excessive runoff that leads to frequent occurrences of extreme hydrologic events such as the pluvial (rainfall accumulation) and fluvial (riverine) floods. The conversion of natural areas into urban lands is further exacerbating the rainfall accumulation by increasing surface imperviousness that hinders infiltration of water into the soil. This dissertation predicts and characterizes potential shifts in the future annual stormwater runoff
volumes and runoff extremes under the standalone and coupled changes in climate and land use across inland and coastal urban-natural settings. The research was …

Simulated Annealing Heuristics For The Dynamic Generalized Quadratic Assignment Problem, Yugesh Dhungel

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Dynamic Generalized Quadratic Assignment Problem (DGQAP) is the task of assigning a set of facilities to a set of locations in a multi-period planning horizon such that the sum of the transportation and assignment/reassignment costs is minimized. The facilities may have different space requirements, and the capacities of locations may vary during the multiple-period planning horizon. Also, multiple facilities may be assigned to each location without violating the space capacity of the location. This research presents a formulation and applications of DGQAP in various layout and assignment problems encountered in the literature. Two Simulated Annealing (SA) metaheuristics named SA …

Detection Of Fecal Bacteria In Watersheds Impacted By Acid Mine Drainage, Claire Addison Mcdonald

Graduate Theses, Dissertations, and Problem Reports (ETD)

Escherichia coli, a fecal coliform, is an essential component of water quality monitoring, entering waterways through sewage deposits, agricultural land and livestock, and wildlife. Various fast and user-friendly methods for quantifying E. coli make it the principal indicator bacteria for fecal contamination. The most common methods for E. coli quantification are culture-based and involve cultivating samples onto nutrient agar and counting the visible colonies. However, E. coli can enter a viable but non-culturable (VBNC) state in stressful environments. Bacteria in a VBNC state are still alive but reduce key metabolic activities that typically encourage growth and division, allowing them …

Efficacy Of Reported Issue Times As A Means For Effort Estimation, Paul Phillip Maclean

Graduate Theses, Dissertations, and Problem Reports (ETD)

Software effort is a measure of manpower dedicated to developing and maintaining and software. Effort estimation can help project managers monitor their software, teams, and timelines. Conversely, improper effort estimation can result in budget overruns, delays, lost contracts, and accumulated Technical Debt (TD). Issue Tracking Systems (ITS) have become mainstream project management tools, with over 65,000 companies using Jira alone. ITS are an untapped resource for issue resolution effort research. Related work investigates issue effort for specific issue types, usually Bugs or similar. They model their developer-documented issue resolution times using features from the issues themselves. This thesis explores a …

Inferential Statistics And Information Theoretical Measures: An Approach To Interference Detection In Radio Astronomy, Morgan R. Dameron

Graduate Theses, Dissertations, and Problem Reports (ETD)

In a time when technology is rapidly growing, radio observatories are now able to expand their computational power to achieve higher receiver sensitivity power and a more flexible realtime computing approach to probe the universe for its composition and study new astronomical phenomena. This allows searches to go deeper into the universe, and results in the recording of massive quantities of observed data. At the same time, this increases the amount of radio frequency interference (RFI) found in the obtained observatory data. The high power of RFI easily masks the low power of extraterrestrial signals, making them hard to detect …

A Tool For Biometric Interpretation Of Forensic Str Dna Profiles, Ahmad Jamal Baroudi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rapid DNA biometric identification applications are becoming more essential and widely used in human identity validation processes. Despite their powerful identification capabilities, processing a sample to generate a forensic DNA profile still takes longer compared with other rapid biometric technologies. Methods used to speed up the analysis could lead to signal artifacts similar to those arising from low copy or degraded DNA samples, making the electropherogram unsuitable for forensic interpretation and analysis. The goal of this research effort is to apply biometrics and mathematical approaches to forensic STR (Short Tandem Repeat) profiles. To accomplish this goal, a multi-function software tool …

Performance Enhancement Of Organic Light-Emitting Diodes By Electronic Doping, David A. Shelhammer

Graduate Theses, Dissertations, and Problem Reports (ETD)

Since the invention of organic light-emitting diodes (OLEDs) nearly 40 years ago, significant effort has been put into realizing their full potential. OLEDs exhibit several properties that make them ideal candidates for applications in displays as well as solid-state lighting: low power consumption, high contrast ratios, mechanical flexibility, and wide viewing angles. However, the low electrical conductivity and poor stability of organic materials remain critical factors that limit device performance. The focus of this work is OLED performance improvement through the introduction of novel inorganic dopants into organic charge transport layers. The results show a significant reduction in operating voltage …

Functionally Magnetic Gradient Copper-Nickel Material Fabricated Via Directed Energy Deposition, Vy Tran Phuong Nguyen

Graduate Theses, Dissertations, and Problem Reports (ETD)

Functionally gradient materials (FGMs) of CuSn10 and Inconel 718 were fabricated via a hybrid directed energy deposition (DED) system. The objective of the present thesis is to determine the feasibility of manufacturing CuSn10 and Inconel 718 FGMs via DED and investigate the physical and mechanical properties and the microstructures of the resulting FGMs. The physical tests comprised of conductivity and Seebeck coefficient measurements. The microstructure analysis and mechanical testing include microscopic imaging, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and hardness test. In addition, compressive strength test was performed to analyze the interface bonding behaviors.

Aerodynamic Performance Of A Biologically Inspired Hybrid Plasma-Mechanical Flow Control And Sensing Device, Joseph Dygert

Graduate Theses, Dissertations, and Problem Reports (ETD)

The continued high global demand for passenger and freight air traffic along with increased use of unmanned aerial vehicles operating in broader Reynolds number regimes has resulted in researchers examining alternative technologies, which would result in safer, more reliable, and superior performing aircraft. Aerodynamic flow control may be one of the most promising approaches to solving this problem, having already proven its ability to enable higher flow efficiency while simultaneously improving overall control of flow behavior such as laminar-to-turbulent transition. Recent research in aerodynamic flow control has seen a pronounced growth in the areas of biomimicry and plasma flow control …

Information Theoretical Analysis Of The Uniqueness Of Iris Biometrics, Katelyn M. Hampel

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the rapid globalization of technology in the world, the need for a more reliable and secure online method of authentication is required. This can be achieved by using each individual’s distinctive biometric identifiers, such as the face, iris, fingerprint, palmprint, etc.; however, there is a bound to the uniqueness of each identifier and consequently, a limit to the capacity that a biometric recognition system can sustain before false matches occur. Therefore, knowing the limitations on the maximum population that a biometric modality can uniquely represent is essential now more than ever. In an effort to address the general problem, …

Thermochemical Water-Splitting Using Novel High-Entropy Perovskite Oxides, Hector Alexis De Santiago Hernandez

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this project, we designed, synthesized, and tested the transformative (La_0.8Sr_0.2)(Mn_[1-x]/3Fe_[1-x]/3Co_xAl_[1-x]/3)O₃ (0 ≤ x ≤ 1.0) high-entropy perovskite oxides (HEPOs) as redox active oxygen carriers for thermochemical hydrogen production with improved stability, kinetics, and H₂ yield. The developed HEPOs form an R3c (hexagonal) phase and were successfully synthesized using both the Pechini and solid-state reactions with the latter synthesis being the primary source for testing. These innovative perovskites demonstrated an improved kinetics with oxygen surface exchange coefficient, k, greater than 7.5 x 10^-4 cm/s, …

An Analysis On Adversarial Machine Learning: Methods And Applications, Ali Dabouei

Graduate Theses, Dissertations, and Problem Reports (ETD)

Deep learning has witnessed astonishing advancement in the last decade and revolutionized many fields ranging from computer vision to natural language processing. A prominent field of research that enabled such achievements is adversarial learning, investigating the behavior and functionality of a learning model in presence of an adversary. Adversarial learning consists of two major trends. The first trend analyzes the susceptibility of machine learning models to manipulation in the decision-making process and aims to improve the robustness to such manipulations. The second trend exploits adversarial games between components of the model to enhance the learning process. This dissertation aims to …

Performance Of Sensor Fusion For Vehicular Applications, Nikola Janevski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensor fusion is a key system in Advanced Driver Assistance Systems, ADAS. The perfor-
mance of the sensor fusion depends on many factors such as the sensors used, the kinematic
model used in the Extended Kalman Filter, EKF, the motion of the vehicles, the type of
road, the density of vehicles, and the gating methods. The interactions between parameters
and the extent to which individual parameters contribute to the overall accuracy of a sensor
fusion system can be difficult to assess.
In this study, a full-factorial experimental evaluation of a sensor fusion system based
on a real vehicle was performed. …

Machine Learning Based Real-Time Quantification Of Production From Individual Clusters In Shale Wells, Ayodeji Luke Aboaba

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over the last two decades, there has been advances in downhole monitoring in oil and gas wells with the use of Fiber-Optic sensing technology such as the Distributed Temperature Sensing (DTS). Unlike a conventional production log that provides only snapshots of the well performance, DTS provides continuous temperature measurements along the entire wellbore.

Whether by fluid extraction or injection, oil and gas production changes reservoir conditions, and continuous monitoring of downhole conditions is highly desirable. This research study presents a tool for real-time quantification of production from individual perforation clusters in a multi-stage shale well using Artificial Intelligence and Machine …

Application Of Artificial Intelligence For Co2 Storage In Saline Aquifer (Smart Proxy For Snap-Shot In Time), Marwan Mohammed Alnuaimi

Graduate Theses, Dissertations, and Problem Reports (ETD)

In recent years, artificial intelligence (AI) and machine learning (ML) technology have grown in popularity. Smart Proxy Models (SPM) are AI/ML based data-driven models which have proven to be quite crucial in petroleum engineering domain with abundant data, or operations in which large surface/ subsurface volume of data is generated. Climate change mitigation is one application of such technology to simulate and monitor CO2 injection into underground formations.

The goal of the SPM developed in this study is to replicate the results (in terms of pressure and saturation outputs) of the numerical reservoir simulation model (CMG) for CO2 injection into …

Generation Of High Performing Morph Datasets, Kelsey Lynn O'Haire

Graduate Theses, Dissertations, and Problem Reports (ETD)

Facial recognition systems play a vital role in our everyday lives. We rely on this technology from menial tasks to issues as vital as national security. While strides have been made over the past ten years to improve facial recognition systems, morphed face images are a viable threat to the reliability of these systems. Morphed images are generated by combining the face images of two subjects. The resulting morphed face shares the likeness of the contributing subjects, confusing both humans and face verification algorithms. This vulnerability has grave consequences for facial recognition systems used on international borders or for law …

Landmark Enforcement And Principal Component Analysis For Improving Gan-Based Morphing, Samuel W. Price

Graduate Theses, Dissertations, and Problem Reports (ETD)

Facial Recognition Systems (FRSs) are a key target for adversaries determined to circumvent security checkpoints. Morph images threaten FRS by presenting as multiple individuals, allowing an adversary to swap identities with another subject. Although morph generation using generative adversarial networks (GANs) results in high-quality morphs without possessing the spatial artifacts caused by landmarkbased methods, there is an apparent loss in identity with standard GAN-based morphing methods. In this thesis, we examine landmark-based and GAN-based morphing methods to fuse the advantages of both methodologies. We propose a novel StyleGAN2 morph generation technique by introducing a landmark enforcement method. Considering this method, …

Evaluating Effects Of Sediment On Microbial Loading In A Drinking Water Distribution System, Erika Osborne

Graduate Theses, Dissertations, and Problem Reports (ETD)

Drinking water distribution systems (DWDS) are critical for protecting public health by ensuring safe water is transported from centralized treatment facilities to consumers. Sediment accumulation in DWDS is a common challenge that water utilities face that may pose some health risks when waterborne pathogens colonize biofilms formed on the sediment surface. Water utilities often establish flushing routines to help mitigate sediment accumulation in their system but the role that sediment plays in contributing to the total microbial loading in the system is unclear. The main objective of this study was to determine if sediment in a DWDS presents a significant …

Design And Control Of Intensified Membrane Reactor Systems Through Module-Based Design Approach, Brent Bishop

Graduate Theses, Dissertations, and Problem Reports (ETD)

As interest in the modularization and intensification of chemical processes continues to grow, more research must be directed towards the modeling and analysis of intensified process units. Intensified process units such as membrane reactors pose unique challenges pertaining to design and operation that have not been fully addressed in the reported literature. This work aims to address the design and control challenges caused by the integration of phenomena and the loss of degrees of freedom (DOF) that occur in the intensification of modular membrane reactor units.

First, a novel first-principles approach for modeling membrane reactors is developed using the AVEVA …

Ethane Dehydrogenation For Light Olefins Production Over Stable Catalyst, Xiaoyan Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Accompanied by the development of modern industry, the demand for light olefins (e.g., ethylene, propylene, butene, butadiene) increases year by year. Light olefins are important intermediates in producing polymers (Polyethylene, Polypropylene, etc.) and rubber (Styrene Butadiene Rubber, Polybutadiene rubber, etc.). The primary process for the production of light olefins is steam cracking of petroleum liquids (naphtha and distillate fuel oil). It is an energy-intensive process, requiring high temperature (750-850℃) and pressure (1.0-4.5 MPa). Meanwhile, due to undesired side reactions, this process has lowered the efficiency of light olefins production and suffers from severe coking issues. Furthermore, as petroleum liquids become …

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Real-time health monitoring of high temperature systems (>500^oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …

Carbon Monoxide Sensing Of Nickel Oxide At 1000 ℃ To 1200 ℃ For In Situ Combustion Control: Behavior, Mechanism, And Application, Yi Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

An advanced smart sensor network is essential to a combustion system, which is in favor of in situ, locally placed, and low-cost gas sensors. However, most chemical/electrochemical sensors fail to work in a combustion boiler, due to the demanding working temperatures (> 1000 ℃). This work for the first time reports a well-functioning mixed-potential type CO sensor at 1000 ℃ - 1200 ℃ using nickel oxide (NiO) as the sensing material. The influence of feed gas flow rate, electrode thickness, and porosity on sensor behavior is investigated, delivering notable and fast responses to 1000 ppm in 3% O₂: …

Air-Assisted Communications Using Line-Of-Sight Links, Shaikha A. Alkandari

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recently, there has been a rapid increase in the use of air-assisted communications involv-
ing the use of airborne platforms such as unmanned aerial vehicles (UAVs). In air-assisted
networks, the UAVs can act like base stations in a traditional cellular network as long as an
appropriate backhaul is available. Alternatively, the UAVs could serve as relays, for instance,
connecting two ground-based users who are within range of the UAV. UAVs have the benefit
of being deployed and reconfigured rapidly and on demand.
Meanwhile, there has been a trend towards the use of higher and higher frequencies,
including those in millimeter-wave …

Development Of Oxide Dispersion Strengthening (Ods) Alloys Powder For Additive Manufacturing, Changyu Ma

Graduate Theses, Dissertations, and Problem Reports (ETD)

Additive manufacturing (AM) fabricated oxide dispersion strengthened (ODS) alloys are given high expectations for critical structural components such as the first stage turbine blade for their excellent creep strength and oxidation resistance compared to superalloys. However, the powder feedstock processing is still an open question since current state-of-the-art processes are not capable of achieving ultrafine strengthening elements such as Y₂O₃ in powder which leads to agglomeration issues in as-consolidated alloys. In this research, the oxidation behavior and stability of ultrafine oxide in AM-printed alloys using mechanically alloyed powders were evaluated at 1100 ^oC. In addition, a …