Engineering Commons^™

Synchronization And Antisynchronization Protocol Design Of Chaotic Nonlinear Gyros: An Adaptive Integral Sliding Mode Approach, Fazal Ur Rahman, Qudrat Khan, Rini Akmeliawati

Turkish Journal of Electrical Engineering and Computer Sciences

A novel control protocol design, via integral sliding mode control with parameter update laws, for synchronization and desynchronization of a chaotic nonlinear gyro with unknown parameters is the focus of this work. The error dynamics of the actual system are substructured into nominal and uncertain parts to employ adaptive integral sliding mode (AISM) control. The uncertain parameters are estimated via devised adaptive laws. Then the disagreement dynamics are guided to origin via AISM control. The stabilizing controller is also designed in terms of nominal control along with a compensating component. The control and the parameter update laws are constructed to …

Oxidative Degradation Of Lignin And Investigation Of Utilization Of Lignin-Derived Materials As Building Blocks For Epoxy Resins, Zhen Fang

Theses and Dissertations--Chemistry

Lignin, the second most abundant biopolymer on earth, is potentially a replaceable source for bulky fuels and chemical feedstocks. There have been numerous reports on methods for the oxidative cleavage of β-O-4 linkages but relatively few reports of how those methods affect other linkages that are present in lignin. We investigated how the β-1 and β-5 linkages respond under oxidative conditions proposed for lignin deconstruction based on their effect on β-O-4 linkages. Mechanochemical treatment of lignin can greatly improve the yield of monomer products and we applied a mechanochemical approach, using powerful ring-and-puck milling to promote lignin degradation. Along with …

Benchmarking And Evaluating The Efficiency Of Mass Transit Systems Based On Best Practice Using Data Envelopment Analysis, Jacqueline Nayame, Maoloud Dabab, Timothy Anderson

Engineering and Technology Management Faculty Publications and Presentations

Public transit systems in the USA have been faced with mounting pressure to decrease their operating costs while at the same time expected to increase ridership and meeting multiple societal needs. The primary objective of this study is to measure the efficiencies of mass transit agencies based on best practice in the US, identify the influencing factors leading to their efficiencies, and how these strategies and policies can be used improve inefficiency in transit agencies. Using Data Envelopment Analysis (DEA) method, the study analyzed the mass performance of 334 transit agencies across the US using data from the national transit …

Youtube’S Terms Of Service: Posthumanism, Algorithms, And Professional Writing, Sarah Bresnahan

Graduate Research Theses & Dissertations

This thesis aims to examine YouTube’s Terms of Service as it applies to content creators (known as YouTubers) who use the platform as a means of financial gain and how YouTube’s demonetization policy via an algorithm is negatively affecting them. I conducted a case study featuring one creator, Michelle Guido, and attempted to determine why some of her content is demonetized when it fulfills YouTube’s content standards for monetization. This study is meant as an examination through the lens of Dr. N. Katherine Hayles’s theory of posthumanism as stated in her book, How We Became Posthuman, and will offer insight …

Direct Polymer Grafting As A Method Of Maintaining The Mechanical Properties Of Cellulose Nanocrystals In The Presence Of Moisture, Mary Elizabeth Breen-Lyles

Graduate Research Theses & Dissertations

Cellulose nanocrystals (CNCs) are a distinctive nanomaterial derived from cellulose, the most abundant natural polymer on Earth, and the primary reinforcing structural component of cellulose fibrils found within the plant cell wall. These nanocrystals exhibit mechanical properties comparable to synthetic aramid fibers but are advantageous as they are biodegradable, renewable, and can be produced sustainably as they are predominantly extracted from naturally occurring cellulosic materials. These qualities make it a sustainable, highly renewable and environmentally friendly material to be used in place of synthetic materials in a variety of applications. With their high surface area to volume ratio, low level …

Validation Of A Low-Cost Sensor For Development Of Wearable And Handheld Spectrometers, Justin Leslie Cathey

Graduate Research Theses & Dissertations

This study examined the possibility of creating a quantitative radiometric spectrometer from a low-cost relative radiometric spectrometer sensor through the use of statistical analysis and development of a correction factor (p > 0.05). Radiometric spectrometers are able to measure and fully characterize the radiometric and photometric characteristics of light, while relative spectrometers are not able to fully, quantitatively characterize the radiometric response from a light source, thus they are less expensive. The spectrometer created in this research is able to measure and produce comparative lighting parameters as well as an actual radiometer spectrometer.

The photoreceptors cells within the human eye allow …

Studying The Effect Of Vacancies On The Thermal Conductivity Of Metal-Coated Carbon Nanotubes Using Molecular Dynamics Atomistic Simulations, Ravindra Sunil Dhumal

Graduate Research Theses & Dissertations

Breakthroughs in nanotechnology have made it possible for the size of electronic gadgets to be scaled down to micro/nano level. What follows however, is the side effect of high power densities and overheating as the heat dissipation is restricted to very small surface area. Thus, the need of an effective thermal management system is central to these developments. One way to counter this problem is to use Thermal Interface Materials (TIMs) which promote heat transfer between heat source and sink.

Owing to their high thermal conductivity (up to 6000 W/mK), Carbon Nanotubes (CNTs) are thought of as strong candidates for …

Steady Flows In Annular Wedge Lid-Driven Cavities, Anandan Ganapathy

Graduate Research Theses & Dissertations

The lid-driven cavity is a well-known canonical problem in the field of analytical and computational fluid dynamics. It is comprised of a square domain of an incompressible fluid with its upper lid has a specified velocity and the remaining wall boundaries are subjected to fixed, no-slip, zero-velocity constraints. There are numerous examples found in the literature that address the well-known, stable behavior of this system, which includes a primary recirculating vortex, secondary corner vortices, and a velocity profile through the center midpoint y-axis that is shown to be dependent on the Reynolds number. In this investigation, the shape of the …

Proper Orthogonal Decomposition Analysis Of Lid-Driven Cavity Flows Containing Particle Suspensions., Nitin Katiki

Graduate Research Theses & Dissertations

Previous experiments done on the square lid driven cavity have shown that its stability and transitional behavior, and by extension the behavior of more complex flows, can be greatly modified by introducing systematic disturbances called perturbations to its flow field. In this study, a square lid driven cavity is calculated in two-dimensional space and perturbed by means of particles suspended in the flow. The perturbations manifest as subtle changes in the flow field velocity and overall flow structure, these are caused by the particle-fluid drag interaction and the particle-particle collision interaction. To understand the nature of these changes and their …

Temporal Dynamics Of Human Emotional Response To Aversive Stimuli, Joseph Lawence Kempel

Graduate Research Theses & Dissertations

Emotions are an integral part of human expression and are often communicated nonverbally through behavioral actions. With advancements in electroencephalography (EEG) technology it is now possible to measure the dynamics of emotion generation in an individual on the basis of patterns in their brain activity. This thesis aims to model the temporal dynamics of human emotion generation upon exposure to aversive stimuli and measure the effect of external distractions as a viable emotion regulation strategy.

This research builds on previous work in the literature that has shown that the ability of humans to regulate their emotions intrinsically (based on their …

The Treatment Of Contaminated Water Using Electrocoagulation, Adebayo Edward Adejinle

Graduate Research Theses & Dissertations

Wastewater treatment is a process that is used to remove significant amount of contaminant concentration from wastewater, which prevents harm to the environment. Chemical coagulation (CC) is one of the most influential processes used to remove contaminants, and it is the addition of chemicals called coagulants, which causes particles to stick together forming bigger flocs. However, as effective as CC is, it requires bench scale testing for determining the appropriate dosing rate for specific raw water properties, which makes the process time consuming. To eliminate these issues, the introduction of the Electrocoagulation (EC) process is considered. The EC process is …

Sky Surveys Scheduling Using Reinforcement Learning, Andres Felipe Alba Hernandez

Graduate Research Theses & Dissertations

Modern cosmic sky surveys (e.g., CMB S4, DES, LSST) collect a complex diversity of astronomical objects. Each of class of objects presents different requirements for observation time and sensitivity. For determining the best sequence of exposures for mapping the sky systematically, conventional scheduling methods do not optimize the use of survey time and resources. Dynamic sky survey scheduling is an NP-hard problem that has been therefore treated primarily with heuristic methods. We present an alternative scheduling method based on reinforcement learning (RL) that aims to optimize the use of telescope resources for scheduling sky surveys.

We present an exploration of …

Studies On Semiconductor Gas Sensors Using Nanostructure Growth Employing Ortho-Glancing Angle Deposition, Dean R. Walters

Graduate Research Theses & Dissertations

A program of research was undertaken to develop the next generation of metal oxide gas sensors, which, for the purpose of this research, were made from materials using a unique approach of glancing angle deposition (GLAD) that is scalable to large scale production. This research seeks to demonstrate that high-sensitivity sensors can be produced. The sensors were examined in a test system of novel design in which the units underwent performance measurements using analyte gases, such as carbon dioxide, nitrogen, and water.

Gas sensors can be improved by increasing the surface area of the active sensing media, and in this …

Knot Optimization For Univariate Cubic L^1 Spline Fits With Application In Change Point Detection, Manfei Xie

Graduate Research Theses & Dissertations

Cubic $L^1$ spline fits, as a type of $L^1$ approximating splines, have shown superior performance in shape preservation of geometric data with great changes. To better construct a cubic $L^1$ spline fit, the number and the location of the spline knots should be optimized rather than predetermined. This research investigates knot optimization methods for univariate cubic $L^1$ spline fits. When the number of knots is given, we design an optimization-based method to determine the best location of the knots. When the number and the location are unknown, we propose a heuristic method to find proper knot number and location. Numerical …

Implementation Of The Shpb System For Material Property Test Under High Strain Rate Deformation, Jiaqi Zhu

Graduate Research Theses & Dissertations

Since Bertram Hopkinson first raised the concept of Hopkinson pressure bar in 1914, many efforts have been taken by engineers and scholars for developing the system to measure the stress pulse propagation in metal bars for studying the properties of different materials under high strain rate deformation. The Northern Illinois University Material’s Lab has also built two generations of the split Hopkinson pressure bar (SHPB) system with the effort of several senior design teams in history.

The aim of this study is to develop the existing SHPB system of NIU to make it function properly. By redesigning the gun barrel, …

Thermal Analysis And Design Of Conduction Links For A Superconducting Radio Frequency Resonator, Aaron Mckeown

Graduate Research Theses & Dissertations

The SRF conduction link project at Fermi National Accelerator Laboratory aims to develop an SRF particle accelerator design that is more applicable for industrial use. Collaboration between NIU college of engineering and NIU department of physics provided the bulk of design and analysis for this project. Currently, cooling systems, used in SRF particle accelerators, pump liquid helium across the SRF cavity to provide convection based cooling. The goal of this project is to incorporate a conduction based cooling system. In a conduction based cooling system, heat will flow from the SRF cavity into a cryocooler through a conduction link. In …

Improving Link Quality Estimation In Zigbee Networks, Srikar Meka

Graduate Research Theses & Dissertations

Estimation of links in a Wireless Sensor Network and using such estimates to decide between all the multiple paths available in a network is important. There are several link estimation methods available. This thesis evaluates the performance of PRR based method (P-success method), suggested in the ZigBee specification and LQI based method (LQI method) used by different organizations, in various scenarios. The performance of these two link cost estimation methods is also compared under Wi-Fi interference. This comparison is done using a network simulator (NS3). It is observed that, if there is no Wi-Fi interference, both the P-success and LQI …

The Short-Term Effects Of Interstate Highways On Small Rural Communities: A Case Study Of I-39, I-49 And I-72, 1990 To 2000, John Paul Metelko

Graduate Research Theses & Dissertations

The presence of interstate highways in rural areas improves access to nearby rural

communities and changes those communities’ spheres of influence. Research into

understanding how improved access from interstate highways affects rural communities

is needed. This case study was designed to investigate how rural communities changed

on the basis of population, vacancy, median home value, and median contract rent in the

short term after an interstate highway was completed nearby in the early 1990s.

The communities included in this study are incorporated cities, towns, villages

and census-designated places in non-metropolitan counties with at least one incorporated

city, town, village and …

Exploring Cyber-Physical Systems, Misbah Uddin Mohammed

Graduate Research Theses & Dissertations

The advances in IOT, Computer Vision, AI and Machine Learning have made these technologies ubiquitous to our daily lives. From Smart Phones to Connected Vehicles, Cyber Physical systems have been interspersed into everything we interact in today’s world. The aim or this thesis was to explore these advances in Cyber Physical Systems and analyze the different sectors they were affecting. We then hand-picked certain domains and explored further by carrying out practical projects using some of the latest software and hardware resources available. Technologies like Amazon Alexa services, NVIDIA Jetson boards, TensorFlow, OpenCV, NodeJS were heavily employed in our various …

The Effects Of Using A Mobile Digital Assistive Tutor For Circuit Analysis On Students’ Academic Achievement, Problem-Solving And Self-Efficacy, Kenie Moses

Graduate Research Theses & Dissertations

This experimental research study examined the effects of using a mobile learning environment (MLE) that provided scaffolded assistive tutoring on student achievement in a Circuit Analysis (Network Theory) course. It also aimed to examine the relationships between students’ user learning analytics and their learning outcomes. The design and development of the mobile app was based on the Model of Contingent Instruction and Metacognitive Support which critically applies scaffolding as its operative in transferring domain knowledge in expert to novice problem-solving.

This experimental research study collected data from eighty-three undergraduate college students who were randomly assigned into one of three groups …

Minimizing Total Number Of Tardy Jobs In Parallel Batch Processing Machines Using Column Generation And Simulated Annealing, Sameer Neupane

Graduate Research Theses & Dissertations

This research considers a scheduling problem where jobs need to be grouped into batches and the batches need to be scheduled on parallel batch processing machines with an objective to minimize the total number of tardy jobs. The jobs are assigned to batches in such a way that machine capacity is not violated. This research considers jobs with unequal ready times, unequal processing times and unequal sizes. The machines are identical in processing capabilities; however, their capacities are different. This research aims to develop effective solution approaches to solve the problem under study. A Mixed Integer Linear Programming (MILP) model …

A Computational Fluid Dynamics Analysis Of The Aerodynamic Performance Of Wind Turbine, Ashkan Ostovari

Graduate Research Theses & Dissertations

Renewable energy resources are likely to be a future energy solution. Among them, the wind has gained a lot of interest. Despite the theoretical limitation in wind energy harnessing efficiency, it is, still, one of the most promising renewable resources with utilizing turbines to extract this energy. Wind turbines, based on their axis of rotation are categorized into vertical axis wind turbine (VAWT) and horizontal axis wind turbine (HAWT), which HAWT’s have shown relatively higher efficiency than VAWT’s. The aim of this thesis is first to develop a scaled-down model of a wind turbine in Computational Fluid Dynamics (CFD) environment …

Computational Methods For Bicubic L1 Splines, Priyesh Koyu Rai

Graduate Research Theses & Dissertations

The past two decades have seen the development of L1 splines for interpolation and approximation of geometric data. L1 splines have been shown to preserve shapes better than the conventional L2 splines, especially for data with abrupt changes in the magnitude of spacing. Efficient computation plays an important role in the practical application of L1 splines. This thesis creates new computational methods for constructing bicubic L1 interpolating splines and bicubic L1 spline fits. The bicubic splines in this study are piecewise bicubic polynomials defined on a rectangular grid generated by the tensor product of nodes. We developed a hybrid computational …

The Study Of Scandate Cathode And Its Characterization Under Various Stages Of Processing, Xiaomeng Zhang

Theses and Dissertations--Chemical and Materials Engineering

Scandate cathode under various processing stages: scandia nano-powder, tungsten scandia mix powder, sintered and impregnated pellets, were characterized with techniques that included electron microscopy, EDS, XPS, and work function measurements. The size and shape uniformity of nano-scale scandia particles changed from round to square and polyhedron during heat treatment. Reduction in size and improvement in size uniformity as heat treating temperature increased were observed. When determining the highest Sc coverage, three assessment methods were used and with their combined results, it was concluded that set VII had the highest Sc at%. In the sintered pellets, it was observed with SEM …

Biomass-Derived Activated Carbons For Electrical Double Layer Supercapacitors: Performance And Stress Effect, Wenxin Cao

Theses and Dissertations--Chemical and Materials Engineering

The vigorous development of human civilization has significantly increased the energy consumption in recent years. There is a great need to use renewable energy sources to substitute the depleting traditional fossil fuels, such as crude oil, natural gas and coal. The development of low-cost and high-performance energy storage devices (ESDs) and systems have drawn great attention due to their feasibility as backup power supply and their applications in portable electronics and electric vehicles. Supercapacitors are among the most important ESDs because of their long charging-discharging cycle life, high power capability and a large operating temperature range. In this thesis, high-performance …

Synthesis, Functionalization, And Application Of Nanofiltration And Composite Membranes For Selective Separations, Andrew Steven Colburn

Theses and Dissertations--Chemical and Materials Engineering

Future nanofiltration (NF) membranes used for selective separations of ions and small organic molecules must maintain performance in environments where high concentrations of total dissolved solvents or foulants are present. These challenges can be addressed through the development of composite membranes, as well as the engineering of enhanced surface properties and operating conditions for existing commercial membranes.

In this work, ion transport through commercial thin film composite (TFC) polyamide NF membranes were studied in both lab-prepared salt solutions and industrial wastewater. The dependence of several variables on ion rejection was investigated, including ion radius, ion charge, ionic strength, and temperature. …

Towards The Rational Design And Application Of Polymers For Gene Therapy: Internalization And Intracellular Fate, Landon Alexander Mott

Theses and Dissertations--Chemical and Materials Engineering

Gene therapy is an approach for the treatment of acquired cancers, infectious disease, degenerative disease, and inherited genetic indications. Developments in the fields of immunotherapies and CRISPR/Cas9 genome editing are revitalizing the efforts to move gene therapy to the forefront of modern medicine. However, slow progress and poor clinical outcomes have plagued the field due to regulatory and safety concerns associated with the flagship delivery vector, the recombinant virus. Immunogenicity and poor transduction in certain cell types severely limits the utility of viruses as a delivery agent of nucleic acids. As a result, significant efforts are being made to develop …

Development Of Novel Temperature Responsive Polymeric Sorbents And Their Applications In Water Remediation, Shuo Tang

Theses and Dissertations--Chemical and Materials Engineering

Water remediation utilizing sorption has found strong interest due to its inexpensiveness, universal nature and ease of operation. In particular, thermo-responsive sorbents consisting of N-isopropylacrylamide (NIPAAm) offer significant potential as “smart” and advanced materials to remove multiple aqueous pollutants. NIPAAm exhibits excellent thermo-responsiveness, which senses the external temperature variation and changes its swelling and sorption behaviors in a sharp and rapid manner. At the beginning of this work, an extensive review of literature has been compiled to provide a summary of NIPAAm-based thermo-responsive sorbents in water/wastewater remediation applications.

Initially, we developed a novel approach to synthesize and characterize NIPAAm copolymeric …

Functionalization Of Iron Oxide Nanoparticles And The Impact On Surface Reactive Oxygen Species Generation For Potential Biomedical And Environmental Applications, Trang Mai

Theses and Dissertations--Chemical and Materials Engineering

Iron oxide nanoparticles (IONPs) have been widely studied for a variety of applications, from biomedical applications (e.g., cell separation, drug delivery, contrast agent for magnetic resonance imaging and magnetically mediated energy delivery for cancer treatment) to environmental remediations (e.g., heavy metal removal and organic pollutants degradation). It has been demonstrated that IONPs can induce the production of reactive oxygen species (ROS) via Fenton/Haber-Weiss reactions which has been shown to be one of the key underlying mechanisms of nanoparticles toxicity. This inherent toxicity of nanoparticles has been shown to enhance the efficacy of traditional cancer therapies such as chemotherapy and radiation. …

Mechanical Properties And Degradation Of High Capacity Battery Electrodes: Fundamental Understanding And Coping Strategies, Yikai Wang

Theses and Dissertations--Chemical and Materials Engineering

Rechargeable lithium ion and lithium (Li) metal batteries with high energy density and stability are in high demand for the development of electric vehicles and smart grids. Intensive efforts have been devoted to developing high capacity battery electrodes. However, the known high capacity electrode materials experience fast capacity fading and have limited cycle life due to electromechanical degradations, such as fracture of Si-based electrodes and dendrite growth in Li metal electrodes. A fundamental understanding of electromechanical degradation mechanisms of high capacity electrodes will provide insights into strategies for improving their electrochemical performance. Thus, this dissertation focuses on mechanical properties, microstructure …