Digital Commons Network^™

Enhancing Emulsion Liquid Membrane System (Elm) Stability And Performance For The Extraction Of Phenol From Wastewater Using Various Nanoparticles, Faris H. Al-Ani, Qusay F. Alsalhy, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Emulation liquid membrane (ELM) technology has recently garnered attention as an efficient alternative for separating pollutants, but it faces the problem of instability during the application, as well as emulsion breaking. With this in mind MgO, Al₂O₃, and three magnetic Fe₂O₃ nanoparticles (of different sizes) were utilized to fabricate a new Pickering ELM system (PELM). The extraction efficiency of phenol from aqueous solution by PELM was studied with different NPs types and with different phenol concentrations (1,000; 500; 100; and 50 ppm). It was found that the type of NPs and concentration of …

Preparation Of Green Biosorbent Using Rice Hull To Preconcentrate, Remove And Recover Heavy Metal And Other Metal Elements From Water, Yongbo Dan, Lei Xu, Zhimin Qiang, Huiyu Dong, Honglan Shi

Chemistry Faculty Research & Creative Works

Sodium hydroxide treated rice hulls were investigated to preconcentrate, remove, and recover metal ions including Be²⁺, Al³⁺, Cr³⁺, CO²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Sr²⁺, Ag⁺, Cd²⁺, Ba²⁺, and Pb²⁺ in both batch mode and column mode. Sodium hydroxide treatment significantly improved the removal efficiency for all metal ions of interest compared to the untreated rice hull. The removal kinetics were extremely fast for Co, Ni, Cu, Zn, Sr, Cd, and Ba, which made the treated rice hull a …

Schizophrenia Classification Using Resting State Eeg Functional Connectivity: Source Level Outperforms Sensor Level, Sima Azizi, Daniel B. Hier, Donald C. Wunsch

Chemistry Faculty Research & Creative Works

Disrupted Functional and Structural Connectivity Measures Have Been Used to Distinguish Schizophrenia Patients from Healthy Controls. Classification Methods based on Functional Connectivity Derived from EEG Signals Are Limited by the Volume Conduction Problem. Recorded Time Series at Scalp Electrodes Capture a Mixture of Common Sources Signals, Resulting in Spurious Connections. We Have Transformed Sensor Level Resting State EEG Times Series to Source Level EEG Signals Utilizing a Source Reconstruction Method. Functional Connectivity Networks Were Calculated by Computing Phase Lag Values between Brain Regions at Both the Sensor and Source Level. Brain Complex Network Analysis Was Used to Extract Features and …

A Kinetic Evaluation For Phenothiazine Base Copolymers, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

In here, the non-isothermal decomposition kinetics of co-polymers-based phenothiazine was present-ed. For this, firstly, 3, 7-di-2-thienyl-10H-phenothiazine (TF) was prepared via an optimized Suzu-ki–Miyaura cross-coupling reaction. After monomer (TF) characterization, the copolymerization re-actions with EDOT and thiophene were performed by the electrochemical technique. The molecular masses of the co-polymers were found by gel permeation chromatography (GPC) analysis. Thermal characterizations of the resulting polymers were conducted by thermogravimetric analyses. The thermal decomposition kinetics of the resulting polymers was also performed. For this, the kinetic methods (Tang, FWO, KAS, Kissinger, and Friedman) based on the multiple heating rates were used. Several kinetic parameters …

A Multi-Elm Model For Incomplete Data, Baichuan Chi, Amaury Lendasse, Edward Ratner, Renjie Hu

Engineering Management and Systems Engineering Faculty Research & Creative Works

This Paper Presents a Novel Model of Extreme Learning Machines (Elms) for Incomplete Data. Elms Are Fast Accurate Randomized Neural Networks. Nevertheless, Elm Can Only Be Applied on the Complete Dataset. Therefore, a Novel Multi-Elm Model for Incomplete Data is Proposed, Consisting of Multiple Secondary Elms and One Primary Elm. the Secondary Elms Are Approximating the Primary Elm's Hidden Neurons' Outputs for the Data with Missing Values. as Summarized in the Experimental Section, This Model Can Be Applied on Data with Any Missing Patterns, without using Imputations and Can Outperform the Traditional Imputation Methods within a Reasonable Fraction of Missing …

Phase Diagram, Stability And Magnetic Properties Of Nonlinear Excitations In Spinor Bose-Einstein Condensates, Garyfallia Katsimiga, Simeon I. Mistakidis, P. Schmelcher, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We Present The Phase Diagram, The Underlying Stability And Magnetic Properties As Well As The Dynamics Of Nonlinear Solitary Wave Excitations Arising In The Distinct Phases Of A Harmonically Confined Spinor F = 1 Bose-Einstein Condensate. Particularly, It Is Found That Nonlinear Excitations In The Form Of Dark-Dark-Bright Solitons Exist In The Antiferromagnetic And In The Easy-Axis Phase Of A Spinor Gas, Being Generally Unstable In The Former While Possessing Stability Intervals In The Latter Phase. Dark-Bright-Bright Solitons Can Be Realized In The Polar And The Easy-Plane Phases As Unstable And Stable Configurations Respectively; The Latter Phase Can Also Feature …

Design Of Dual-Band Decoupling Network For Two Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a dual-band decoupling network for two antennas. Design formulas are derived with systematic design procedures. Two benchmarks are presented to elaborate on the design procedure. Results show that the network offers impedance matching, high isolation, and high efficiency at both frequencies, verifying the proposed concept and theory.

Model Computation With Second-Order Radiative Transfer Equation For Snow Medium Using Coupled Finite Element Method And Method Of Moment And Relaxed Hierarchical Equivalent Source Algorithm, Hamsalekha A. Kumaresan, H. T. Ewe, Gobi Vetharatnam, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave remote sensing is essential to monitor the conditions of the environment by analyzing the microwave returns from the earth terrain. Various Computational Electromagnetics (CEM) techniques are implemented to study the backscattering coefficient of numerous earth terrains such as vegetation and snow medium. In this paper, a theoretical model based on second order radiative transfer equation is investigated by incorporating two computational methods which are known as coupled Finite Element Method (FEM) and Method of Moment (MoM), and Relaxed Hierarchical Equivalent Source Algorithm (RHESA). These theoretical models consider three shapes of scatterers which can be used to represent the …

Review On Resistive Switching Mechanisms Of Bio-Organic Thin Film For Non-Volatile Memory Application, Kuan Yew Cheong, Ilias Ait Tayeb, Feng Zhao, Jafri Malin Abdullah

Electrical and Computer Engineering Faculty Research & Creative Works

Bio-organic, as one of the sustainable and bioresorbable materials, has been used as an active thin film in producing resistive switching random access memory (RRAM) due to its specialized properties. This type of nonvolatile memory consists of a simple unit structure with the processed and solidified bio-organic-based thin film sandwiched between two electrodes. Its memory characteristics are significantly affected by the resistive-switching mechanism. However, to date, the reported mechanisms are very diverse and scattered, and to our best knowledge, there is no literature that reviewed comprehensively the mechanisms of resistive switching in bio-organic-based thin films. Therefore, the objective of this …

Novel Transformer With Variable Leakage And Magnetizing Inductances, Angshuman Sharma, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces the concept of a novel variable inductance transformer (VIT) whose leakage and magnetizing inductances can be varied dynamically and independently to aid the advancement of research in isolated power electronic converters. In this transformer, the leakage inductance can be varied by varying the length of overlap between the primary and secondary windings, while the magnetizing inductance can be varied by varying the air gap between the core legs. Individual controls for the two inductances ensure that one can be varied independent of the other, as needed to satisfy different power conversion objectives. In this paper, the analytical …

Multidimensional Extensions To Generalized Averaged Models For Multi-Frequency-Excited Dynamic Systems, Kartikeya Jayadurga Prasad Veeramraju, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel Harmonic Axis Decoupling (HAD) method is proposed for extending the capabilities of the Generalized Averaged Modeling (GAM) technique. The conventional GAM technique is first revisited, and the problems encountered in the multiplication of two Double Fourier Series (DFS) signals in the time domain are investigated. The method of translating Fourier vectors to Discrete Fourier Images (DFI) in the frequency plane is proposed, and the ramifications of this conversion on DFS product terms in the time domain are investigated. The two-dimensional DFI convolution technique resulting from HAD is used for the dynamic modeling of power converters …

Detection Of Gaussian Attacks In Power Systems Under A Scalable Kalman Consensus Filter Framework, Arnold Fernandes, Rui Bo, Jonathan W. Kimball, Bruce M. Mcmillin

Electrical and Computer Engineering Faculty Research & Creative Works

The dynamic non-linear state-space model of a power-system consisting of synchronous generators, buses, and static loads has been linearized and a linear measurement function has been considered. A distributed dynamic framework for estimating the state vector of the power system has been designed here. This framework employs a type of distributed Kalman filter (DKF) known as a Kalman consensus filter (KCF) which is located at distributed control centers (DCCs) that fuse locally available noise ridden measurements, state vector estimates of neighboring control centers, and a prediction obtained by the linearized model to obtain a filtered state vector estimate. Further, the …

Package Power Distribution Current Density In Applications With Large Transient Currents, Matthew Doyle, Wiren D. Becker, Matteo Cocchini, Kyle Schoneck, Samuel Connor, Layne Berge, Siqi Bai, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A method to model, measure, and characterize a high-transient current in an electrical packaging solution is described herein. These methods help overcome the challenge of generating model to hardware correlation in high current applications. A specialized test platform is developed and used to characterize current density in test hardware. The measurements are used to characterize a custom power distribution network and verify validity of current density predictions. This data is critical in high-current applications for finding and measuring current density through plane pinch points that can cause early failures in the field due to electromigration and delamination.

Automated Cervical Digitized Histology Whole-Slide Image Analysis Toolbox, Sudhir Sornapudi, Ravitej Addanki, R. Joe Stanley, William V. Stoecker, Rodney Long, Rosemary Zuna, Shellaine R. Frazier, Sameer Antani

Electrical and Computer Engineering Faculty Research & Creative Works

Background: Cervical intraepithelial neoplasia (CIN) is regarded as a potential precancerous state of the uterine cervix. Timely and appropriate early treatment of CIN can help reduce cervical cancer mortality. Accurate estimation of CIN grade correlated with human papillomavirus type, which is the primary cause of the disease, helps determine the patient's risk for developing the disease. Colposcopy is used to select women for biopsy. Expert pathologists examine the biopsied cervical epithelial tissue under a microscope. The examination can take a long time and is prone to error and often results in high inter-and intra-observer variability in outcomes. Methodology: We propose …

Evaluation Of Robust Epoxy Resin Sealants For Wellbore Integrity Applications, Mohammed Mousa M Alkhamis

Doctoral Dissertations

"During the drilling and completion phases of oil and gas wells, cement is placed in the wellbore as a barrier between the casing and the formation. All casing strings must be cemented to protect and support the casing, and to isolate production zones. The primary cement must prevent the wellbore fluids from migrating in an annular flow path so as to allow the wells to be utilized without any control problems. The primary cement may fail to deliver full zonal isolation due to several reasons such as insufficient mud removal before the cementing, casing expansion, and contraction, high fluid losses, …

Properties And Structures Of Alkali Molybdenum Iron Phosphate Glasses For Nuclear Waste Immobilization, Jincheng Bai

Doctoral Dissertations

"The development of glasses to immobilize nuclear wastes requires a detailed understanding of how composition affects the critical properties required to design wasteforms, including thermal stability and chemical durability. Those properties depend on the molecular-level structures of the glasses. The principal objective of this research was to develop a comprehensive understanding of the composition-structure-property relationships, including the effects of processing conditions, for glasses in the alkali- molybdenum-iron-phosphate systems that could then be used to inform the development of wasteforms of interest to the US Department of Energy.

The molecular-level structures of the alkali molybdenum iron phosphate glasses were analyzed by …

Fabrication, Characterization And Environmental Monitoring Of Polymer-Based Materials For Biomedical And Structural Applications, Mousumi Bose

Doctoral Dissertations

"Polymers are versatile materials utilized for variety of applications. In biomedical field, luminescence quenching based optical oxygen sensors encapsulated in polymeric substances are gaining attention for early detection of surface wounds associated with tissue oxygen. A simple and low-cost fabrication technique was developed to produce sensor arrays for continuous two-dimensional oxygen tension measurement. Sensor patch along with smart phone-based readout technique is being evaluated as a smart bandage.

The environmental concerns and limited petroleum supply demand for replacing petroleum-based polymers with renewable bio-based sources while maintaining comparable properties. A sustainable and green approach was adopted to synthesize soy polyol-derived rigid …

Prediction Intervals For Fractionally Integrated Time Series And Volatility Models, Rukman Ekanayake

Doctoral Dissertations

"The two of the main formulations for modeling long range dependence in volatilities associated with financial time series are fractionally integrated generalized autoregressive conditional heteroscedastic (FIGARCH) and hyperbolic generalized autoregressive conditional heteroscedastic (HYGARCH) models. The traditional methods of constructing prediction intervals for volatility models, either employ a Gaussian error assumption or are based on asymptotic theory. However, many empirical studies show that the distribution of errors exhibit leptokurtic behavior. Therefore, the traditional prediction intervals developed for conditional volatility models yield poor coverage. An alternative is to employ residual bootstrap-based prediction intervals. One goal of this dissertation research is to develop …

Thermomechanical Simulation And Process Optimization For Hot Rolling Of Steel, Shouvik Ganguly

Doctoral Dissertations

"Hot rolling is a manufacturing process that involves large material deformation, complicated geometries, contact conditions and non-uniform temperature gradients. Steel industries are motivated to prevent hot rolled steel products to be defect free and with desired shape and size. In order to simulate the process accurately, it is essential that the material model for steel accounts for the viscoplasticity and changes in properties that occur in steel at elevated temperatures as grain growth and recrystallization.

The healing of existing voids during hot rolling was investigated using finite element simulations. Voids are highly undesirable as they not only degrade the product …

Fabrication Of 304l Stainless Steel And Aluminum Parts By Laser Foil Printing And Process Automation, Chia-Hung Hung

Doctoral Dissertations

"This work presents research conducted on a novel metal additive manufacturing process, called Laser Foil Printing (LFP), to fabricate metal parts with various geometries layer by layer using metal foil as the feedstock. To investigate the processability and characteristics of LFP for fabricating metal parts, the materials included 304L stainless steel and Al-1100 aluminum alloy. The LFP process parameter windows for both 304L and Al-1100 were determined, and the optimal process parameters with stable formation of the melt pools were selected to fabricate dense metal parts. The microstructure and properties of LFP-fabricated parts were characterized and analyzed using tensile testing, …

Spatiotemporal Variations Of Upper Crustal Anisotropy Along The San Jacinto Fault Zone In Southern California And The Fairview Region In Central Oklahoma, Enyuan Jiang

Doctoral Dissertations

"To discern spatial and explore the possible existence of temporal variations of upper crustal anisotropy along an ~15 km section of the San Jacinto Fault Zone (SJFZ) in California, and in the Fairview, Oklahoma, region, we conduct systematic shear wave splitting (SWS) investigations using local S-wave data recorded by seismic stations. Strong spatial variations in crustal anisotropy are revealed by 1694 and 405 pairs of splitting parameters (including the fast polarization orientation and the splitting time), respectively. For both areas, for raypaths traveling through the fault zones, the fast orientations are parallel to the faults and may be attributed to …

Characterization Of Alaskan Modified Asphalt Binders And Mixtures, Jun Liu

Doctoral Dissertations

"Modified asphalt binders and mixtures have been used more in recent years in Alaska. However, there has not been systematic characterization and performance data development for these materials. This study intends to systematically characterize the Alaskan asphalt binders and mixtures and identify the performance benefits of these materials through laboratory tests and field sections monitoring. The research contains five sections: 1) a comprehensive characterization on the morphologies, chemical and rheological properties of modified asphalt binders and mechanical properties of asphalt mixtures with these modified asphalt binders. The lab testing results were further confirmed through field surveys of recent paving projects …

The Implementation Of Energy Sharing Using A System Of Systems Approach, Julia Morgan

Doctoral Dissertations

"There is an increasing demand for renewable energy and consumers need more procurement options to meet their needs. Energy sharing provides a peer-to-peer (P2P) marketplace where prosumer electricity is redistributed to fellow energy-sharing community participants. This redistribution of prosumer electricity provides consumers with additional electricity suppliers, while also decreasing the load on the utility company. Though significant progress has been made regarding research and implementation of energy sharing, there is still room for growth when evaluating energy-sharing communities and defining appropriate community coordination based on end-user needs. The first contribution in this work identified nine characteristics of energy-sharing communities as …

Scheduling Based Optimization In Software Defined Radio And Wireless Networks, Nathan Daniel Price

Doctoral Dissertations

"The objective of this work is to enable dynamic sharing of software-defined radio (SDR) transceivers through the concepts of hardware virtualization and real-time resource management. SDR is a way to build a digital radio that consists of a software back-end for digital signal processing (DSP) and an analog front-end transceiver for waveform generation and reception. This work proposes the use of a virtualization layer to decouple back-end SDR software from front-end transceivers. With this arrangement, front-ends are said to be virtualized, and it becomes possible to share a limited number of front-ends among many SDR back-ends through different multiplexing techniques. …

Investigation Of Packed Bed And Moving Bed Reactors With Benchmarking Using Advanced Measurement And Computational Techniques, Binbin Qi

Doctoral Dissertations

"Trickle bed reactors (TBR), as typical packed bed reactors (PBR), are widely used in various fields. Very limited information regarding the flow behaviors, hydrodynamic, and mathematical models in extrudate catalyst shapes, such as cylinders, trilobes, and quadrilobes, can be found in literatures because the major focus was on spherical shape. Therefore, a hybrid pressure drops and liquid holdup phenomenological model for extrudate catalyst shapes was developed based on two-phase volume averaged equations, which showed high accuracy against experimental data. The maldistribution and dynamic liquid holdup were investigated in quadrilobe catalyst using gamma-ray computed tomography. A pseudo-3D empirical model was developed …

Modeling Time Series With Conditional Heteroscedastic Structure, Ratnayake Mudiyanselage Isuru Panduka Ratnayake

Doctoral Dissertations

"Models with a conditional heteroscedastic variance structure play a vital role in many applications, including modeling financial volatility. In this dissertation several existing formulations, motivated by the Generalized Autoregressive Conditional Heteroscedastic model, are further generalized to provide more effective modeling of price range data well as count data. First, the Conditional Autoregressive Range (CARR) model is generalized by introducing a composite range-based multiplicative component formulation named the Composite CARR model. This formulation enables a more effective modeling of the long and short-term volatility components present in price range data. It treats the long-term volatility as a stochastic component that in …

Source Reconstruction In Near Field Scanning For Rfi Application, Hosseien Rezaei

Doctoral Dissertations

"This research is divided into three major topics. The first topic, mechanical magnetic field generator for communication in the ULF range, is discussed in the first paper. The second topic, source reconstruction in near field scanning for RFI application, is discussed over the course of two papers. The third topic, analysis of imbalanced 2 or 3 Wire VHF LISN, is discussed in the last two papers.

In the first topic, the possibility to use a mechanical system (a rotating magnet) as a source (generator or antenna combined) of the ULF magnetic field is investigated. Ultralow frequency (ULF) communication systems have …

Modeling And Analyzing Parasitic Parameters In High Frequency Converters, Mohamad Saleh Sanjari Nia

Doctoral Dissertations

"This research focuses on electromagnetic interference (EMI) / electromagnetic compatibility (EMC) design and analysis in power electronics systems. To limit the EMI under the standards, different methods and strategies are investigated. Parasitic parameters of high frequency (HF) transformer are analyzed using a novel analytical method, finite element method (FEM), and experimental measurements for different structures and windings arrangements. Also, the magnetic field, electric field, electric displacement, and electric potential distribution are simulated and analyzed. Moreover, a high voltage system is considered and analyzed to improve the EMC. The EMI propagation paths are analyzed. The EMI noise level of the system …

Pdn Modeling For High-Speed Multilayer Pcb Boards And Decap Optimization Using Machine Learning Techniques, Ling Zhang

Doctoral Dissertations

"In power distribution networks (PDN), there are two main challenges nowadays. One challenge is how to efficiently model and calculate the impedance for arbitrary-shape and multi-layer PDN systems. The second challenge is the optimization of decoupling capacitors in the pre-layout stage. This dissertation proposes novel solutions to these two challenges. To tackle the first challenge, a boundary element method (BEM) is utilized to calculate the quasi-static inductances between vertical vias for arbitrary-shape planes. Then a specialized circuit solver is developed to solve the equivalent circuit of inductances and capacitances for multi-layer PDN structures. Also, a contour integral method (CIM) is …

Crustal And Upper Mantle Structure Beneath The Southeastern United States From Joint Inversion Of Rayleigh Wave Dispersion And Receiver Functions, Qiuyue Yang

Doctoral Dissertations

"In spite of numerous geophysical investigations have been conducted in southeastern United States, the structure and evolution of the crust and lithospheric mantle remain controversial due the thick sedimentary covers atop the crust of the coastal plains there. In this study, we use data from 186 broadband seismic stations belonging to the USArray Transportable Array to construct a 3-D shear wave velocity model for the southeastern United States for the top 180 km by a joint inversion of Rayleigh wave phase velocity dispersion and receiver functions. Our results show a clear spatial correspondence with major surficial geological features. A prominent …