Digital Commons Network^™

Neuroengineering Of Clustering Algorithms, Leonardo Enzo Brito Da Silva

Doctoral Dissertations

"Cluster analysis can be broadly divided into multivariate data visualization, clustering algorithms, and cluster validation. This dissertation contributes neural network-based techniques to perform all three unsupervised learning tasks. Particularly, the first paper provides a comprehensive review on adaptive resonance theory (ART) models for engineering applications and provides context for the four subsequent papers. These papers are devoted to enhancements of ART-based clustering algorithms from (a) a practical perspective by exploiting the visual assessment of cluster tendency (VAT) sorting algorithm as a preprocessor for ART offline training, thus mitigating ordering effects; and (b) an engineering perspective by designing a family of …

Development And Demonstration Of Sampling Techniques For A Chirped Pulse Fourier Transform Microwave Spectrometer, Frank Edward Marshall

Doctoral Dissertations

"With the introduction of the Chirped Pulse-Fourier Transform Microwave Spectrometer in the past decade, it has become possible to rapidly study the rotational spectra of molecules in the gas phase. It is possible to study molecules that are not normally in the gas phase through the use of various sourcing techniques. The development of both the heated nozzle and the laser ablation sourcing techniques allow for the study of liquids and solids, respectively. The design and performance of these sources will be presented in detail and discussed. Additionally, the development of a Multi-Antennae detection scheme, useful in improving overall sensitivity …

Experimental Study On Enhanced Oil Recovery (Eor) Mechanisms Of Nanogel Combining With Low Salinity Water For Carbonate Reservoirs, Pu Han

Doctoral Dissertations

"Nanomaterials have been widely studied and applied in the oil and gas industry. Among the developed nanomaterials, nano-sized crosslinked polymeric gel particle (nanogel) has shown great potential in recovering residual oil and improving oil recovery. This dissertation carried out their potential EOR mechanisms and the synergetic effect between nanogel and low salinity water. Nanogel used in this study was synthesized through the suspension polymerization process in our lab. The morphology, size distribution, and zeta potential were studied for nanogel dispersed in brine with variable ionic strength. The injectivity of nanogel was elucidated at first to ensure their in-depth penetration ability. …

Smart Control Architecture For Microgrid Application, Vikram Roy Chowdhury

Doctoral Dissertations

"This research proposes non-linear control architectures dedicated towards improving transient response, reliability and computational burden for grid connected inverters applicable for ac micro-grids. Also this work proposes an optimization procedure applied to a small microgrid to reduce the billing cost for power incorporating battery degradation mechanism.

Three works are discussed in this research that discusses methodologies to improve the operation of a three phase grid connected inverters. The first work discusses a globally stable estimation architecture for estimating the plant parameters for a grid connected inverter during its operation. Then a Lyapunov based control architecture is utilized and online parameter …

Development Of Functional Ionic Liquids For Separation And Recovery Of Rare Earth Elements, Mostafa Khodakarami

Doctoral Dissertations

“This research focused on the design and synthesis of task-specific ionic liquids for enhanced extraction and separation of rare earth elements (REEs). Two novel ammonium-based functional ionic liquids (FILs) with oxygen donating groups: trioctyl(2-ethoxy-2-oxoethyl)ammonium dihexyl diglycolamate, [OcGBOEt][DHDGA], and tricaprylmethylammonium dihexyl diglycolamate, [A336][DHDGA] were synthesized and tested for the recovery and separation of selected REEs from aqueous solutions. Functionalities with different denticities were incorporated into both anionic and cationic parts of ionic liquids, which are solely composed of incinerable atoms including C, H, O, and N. The structural, physical, and chemical properties of the synthesized FILs were studied using nuclear magnetic …

Supply Chain Infrastructure Restoration Calculator Software Tool -- Developer Guide And User Manual, Akhilesh Ojha, Bhanu Kanwar, Suzanna Long, Thomas G. Shoberg, Steven Corns

Engineering Management and Systems Engineering Faculty Research & Creative Works

This report describes a software tool that calculates costs associated with the reconstruction of supply chain interdependent critical infrastructure in the advent of a catastrophic failure by either outside forces (extreme events) or internal forces (fatigue). This tool fills a gap between search and recover strategies of the Federal Emergency Management Agency (or FEMA) and construction techniques under full recovery. In addition to overall construction costs, the tool calculates reconstruction needs in terms of personnel and their required support. From these estimates, total costs (or the cost of each element to be restored) can be calculated. Estimates are based upon …

Understanding The Connection Between Blasting And Highwall Stability, Robert Quentin Eades, Kyle A. Perry

Mining Engineering Faculty Research & Creative Works

Surface mines continue to implement highwalls for several reasons, such as increasing recovery, improving margins, and justifying higher stripping ratios. Highwall stability is a complex issue that is dependent upon a variety of mining and geologic factors, and a safe design is necessary for a successful surface operation. To improve highwall stability, it is important to understand the connection between local geology and blasting. Explosives are employed throughout the mining industry for primary rock breakage. There are a number of controlled blasting techniques that can be implemented to improve highwall stability. These include line drilling, smooth wall blasting, trim blasting, …

Well-Ordered Mesoporous Silica And Bioactive Glasses: Promise For Improved Hemostasis, Sara Pourshahrestani, Nahrizul Adib Kadri, Ehsan Zeimaran, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Immediate control of uncontrolled bleeding and infection are essential for saving lives in both combat and civilian arenas. Inorganic well-ordered mesoporous silica and bioactive glasses have recently shown great promise for accelerating hemostasis and infection control. However, to date, there has been no comprehensive report assessing their specific mechanism of action in accelerating the hemostasis process and exerting an antibacterial effect. After providing a brief overview of the hemostasis process, this review presents a critical overview of the recently developed inorganic mesoporous silica and bioactive glass-based materials proposed for hemostatic clinical applications and specifically investigates their unique characteristics that render …

Synthesis, Characterization And Selected Application Of Chitosan-Coated Magnetic Iron Oxide Nanoparticles, M. A. Radwan, Mohamed Adel Rashad, M. A. Sadek, Hany A. Elazab

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, we report an efficient method to prepare highly active chitosan-coated magnetic iron oxide nanoparticles by implementing co-precipitation technique which is used for wastewater treatment applications. Chitosan-coated magnetic iron oxide nanoparticles were synthesized and characterized using TEM, XRD, and XPS. A comparative study has been made between chitosan powder and chitosan coated with magnetic nanoparticles with respect to the rate of adsorption of copper from aqueous solution. It was also experimentally verified that chitosan coated magnetic iron oxide nanoparticles are much more effective in adsorption of heavy metals than chitosan powder and it takes just few minutes instead …

Slightly Fluorination Of Al2o3 Ald Coating On Li1.2mn0.54co0.13ni0.13o2 Electrodes: Interface Reaction To Create Stable Solid Permeable Interphase Layer, Han Yu, Yan Gao, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Improving the performance of cathodes by using surface coatings has proven to be an effective method for improving the stability of Li-ion batteries (LIBs), while a high-quality film satisfying all requirements of electrochemical inertia, chemical stability, and lithium-ion conductivity has not been found. In this study, a composite film composed of Al₂O₃ and AlF₃ layers was coated on the surface of Li_1.2Mn_0.54Co_0.13Ni_0.13O₂ (Li-rich NMC) based electrodes by atomic layer deposition (ALD). By varying the ratio of Al₂O₃ and AlF₃, an optimal coating …

Magnetic Composite Biomaterials For Neural Regeneration, Jessica L. Funnell, Bailey Balouch, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Nervous system damage caused by physical trauma or degenerative diseases can result in loss of sensory and motor function for patients. Biomaterial interventions have shown promise in animal studies, providing contact guidance for extending neurites or sustained release of various drugs and growth factors; however, these approaches often target only one aspect of the regeneration process. More recent studies investigate hybrid approaches, creating complex materials that can reduce inflammation or provide neuroprotection in addition to stimulating growth and regeneration. Magnetic materials have shown promise in this field, as they can be manipulated non-invasively, are easily functionalized, and can be used …

Self-Consistent Two-Gap Description Of Mgb₂ Superconductor, Hyunsoo Kim, Kyuil Cho, Makariy A. Tanatar, Valentin Taufour, Stella K. Kim, Sergey L. Bud'ko, Paul C. Canfield, Vladimir G. Kogan, Ruslan Prozorov

Physics Faculty Research & Creative Works

A self-consistent two-gap γ-model is used to quantitatively describe several thermodynamic properties of MgB₂ superconductor. The superconducting coupling matrix, vij, was obtained from the fitting of the superfluid density in the entire superconducting temperature range. Using this input, temperature-dependent superconducting gaps, specific heat, and upper critical fields were calculated with no adjustable parameters and compared with the experimental data as well as with the first-principles calculations. The observed agreement between fit and data shows that γ-model provides adequate quantitative description of the two-gap superconductivity in MgB₂ and may serve as a relatively simple and versatile self-consistent description of …

Resonance Strengths For Kll Dielectronic Recombination Of Highly Charged Mercury Ions And Improved Empirical Z -Scaling Law, Zoltan Harman, Chintan Shah, Antonio J. Gonzalez Martinez, Ulrich D. Jentschura, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Theoretical and experimental resonance strengths for KLL dielectronic recombination (DR) into He-, Li-, Be-, and B-like mercury ions are presented, based on state-resolved DR x-ray spectra recorded at the Heidelberg electron-beam ion trap. The DR resonance strengths are experimentally extracted by normalizing them to simultaneously recorded radiative recombination signals. The results are compared to state-of-the-art atomic calculations that include relativistic electron correlation and configuration mixing effects. Combining the present data with other existing ones, we derive an improved semiempirical Z-scaling law for DR resonance strengths as a function of the atomic number, taking into account higher-order relativistic corrections, which are …

Experimental Investigation Of The Dynamics Of Trapped Non-Wetting Droplets Subjected To The Seismic Stimulation In Constricted Tubes: Supporting Information, Yandong Zhang, Chao Zeng, Baojun Bai, Wen Deng

Research Data

• Aspect Ratio of 4.5
• Aspect Ratio of 9.0
• Video Demos

A Critical Review Of Using High Viscosity Friction Reducers As Fracturing Fluids For Hydraulic Fracturing Applications, Mohammed Ba Geri, Abdulmohsin Imqam, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The primary purpose of using traditional friction reducers in stimulation treatments is to overcome the tubular drag while pumping at high flow rates. Hydraulic fracturing is the main technology used to produce hydrocarbon from extremely low permeability rock. Even though slickwater (water fracturing with few chemical additives) used to be one of the most common fracturing fluids, several concerns are still associated with its use, including usage of freshwater, high-cost operation, and environmental issues. Therefore, current practice in hydraulic fracturing is to use alternative fluid systems that are cost effective and have less environmental impact, such as fluids which utilize …

Investigate The Rheological Behavior Of High Viscosity Friction Reducer Fracture Fluid And Its Impact On Proppant Static Settling Velocity, Mohammed Ba Geri, Abdulmohsin Imqam, Andrey Bogdan, Lingjuan Shen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The recent and rapid success of using high viscosity friction reducers (HVFRs) in hydraulic fracturing treatments is due to several advantages over other fracture fluids (e.g. linear gel), which include better proppant carrying capability, induce more complex fracture system network with higher fracture length, and overall lower costs due to fewer chemicals and less equipment on location. However, some concerns remain, like how HVFRs rheological properties can have impact on proppant transport into fractures. The objective of this study is to provide a comprehensive understanding of the influence the rheological characterization of HVFRs have on proppant static settling velocity within …

Non-Invasive Microwave And Millimeter Wave Reflectometry And Imaging For Human Skin Diagnosis And Materials Characterization, Yuan Gao

Doctoral Dissertations

"Microwave and millimeter wave reflectometry and synthetic aperture radar (SAR) imaging techniques have been successfully applied in many applications, such as nondestructive testing and evaluation (NDT&E), security inspection and medical diagnosis. In this dissertation, the feasibility of using microwave and millimeter reflectometry and SAR imaging for burn diagnosis is investigated through both simulations and measurements, with promising results. To correctly model the interaction between electromagnetic waves and skin, the proper knowledge of the complex permittivity of healthy skin is critically important. To this end, the common used measurement methods for in vivo skin complex permittivity are reviewed and analyzed in …

Development And Characterization Of Nanostructured Steels And High Entropy Alloys For Nuclear Applications, Andrew Kalevi Hoffman

Doctoral Dissertations

"Nuclear reactor materials are subjected to a harsh environment including high temperatures and radiation fluences. In order to extend the lifetime of current light water reactors (LWRs) and realize the development of advanced Gen IV nuclear reactors new materials must be developed which can withstand such an environment. This thesis involves two approaches to solving this materials problem: advanced manufacturing of current commercial alloys using severe plastic deformation (SPD) and the development of new advanced high entropy alloys (HEAs).

Because SPD is effective at achieving grain refinement, this technique was used to obtain material having a high volume fraction of …

A Fermi Gamma-Ray Burst Monitor Search For Electromagnetic Signals Coincident With Gravitational-Wave Candidates In Advanced Ligo's First Observing Run, E. Burns, A. Goldstein, C. M. Hui, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present a search for prompt gamma-ray counterparts to compact binary coalescence gravitational wave (GW) candidates from Advanced LIGO's first observing run (O1). As demonstrated by the multimessenger observations of GW170817/GRB 170817A, electromagnetic and GW observations provide complementary information about the astrophysical source, and in the case of weaker candidates, may strengthen the case for an astrophysical origin. Here we investigate low-significance GW candidates from the O1 compact binary coalescence searches using the Fermi Gamma-Ray Burst Monitor (GBM), leveraging its all sky and broad energy coverage. Candidates are ranked and compared to background to measure the significance. Those with false …

Modeling Impact Of Glass Weave On Differential Phase Skew By Design Of Experiments Method, Feng Zhang

Masters Theses

"The glass weave structure of a manufactured Printed Circuit Board (PCB) is scanned under a Scanning Electron Microscope (SEM), with top-down and cross-sectional views. Previously, analytical methods were used to investigate the glass-weave effect on transition properties in a PCB. Based on the SEM observation, this study was conducted to build full-wave models using various glass-weave types and different relative positions between differential traces and glass-weave bundles. This study aims to obtain the relationship between the glass weave and trace geometry, and the phase skew of the differential trace by using Design of Experiment (DoE) method and simulation results"--Abstract, page …

Applying Deep Learning Approach To The Far-Field Subwavelength Imaging Based On Near-Field Resonant Metalens At Microwave Frequencies, He Ming Yao, Min Li, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we utilize the deep learning approach for the subwavelength imaging in far-field, which is realized by the near-field resonant metalens at microwave frequencies. The resonating metalens consisting of split-ring resonators (SRRs) are equipped with the strong magnetic coupling ability and can convert evanescent waves into propagating waves using the localized resonant modes. The propagating waves in the far-field are utilized as the input of a trained deep convolutional neural network (CNN) to realize the imaging. The training data for establishing the deep CNN are obtained by the EM simulation tool. Besides, the white Gaussian noise is added …

Machine-Learning-Based Pml For The Fdtd Method, He Ming Yao, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, a novel absorbing boundary condition (ABC) computation method for finite-difference time-domain (FDTD) is proposed based on the machine learning approach. The hyperbolic tangent basis function (HTBF) neural network is introduced to replace traditional perfectly matched layer (PML) ABC during the FDTD solving process. The field data on the interface of conventional PML are employed to train HTBF-based PML model. Compared to the conventional approach, the novel method greatly decreases the size of a computation domain and the computation complexity of FDTD because the new model only involves the one-cell boundary layer. Numerical examples are provided to benchmark …

Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu

Doctoral Dissertations

"Engineers always encounter time-dependent uncertainties that ubiquitously exist, such as the random deterioration of material properties and time-variant loads. Therefore the reliability of engineering systems becomes time-dependent. It is crucial to predict the time-dependent reliability in the design stage, given possible catastrophic consequences of a failure. Although extensive research has been conducted on reliability analysis, estimating the reliability accurately and efficiently is still challenging. The objective of this work is to develop accurate and efficient reliability methodologies for engineering design. The basic idea is the integration of traditional reliability methods with saddlepoint approximation (SPA), which can accurately approximate the tail …

Designing Bifunctional Materials For In-Situ Capture And Conversion Of Volatile Organic Compounds, Anirudh Krishnamurthy

Doctoral Dissertations

”Volatile organic compounds (VOCs) are a class of organic liquid compounds with low vapor pressures, which enables them to vaporize at ambient conditions. VOCs are largely toxic, carcinogenic, and mutagenic, and have profound adverse effects on human health and the ecological environment. Many VOCs cause ruinous health effects even at very low concentrations (ppm) and therefore control of these organic compounds is essential for ensuring good air quality. A large portion of VOCs cause catastrophic health effects such as cancer or liver damage even at very low concentrations (ppm), and the control of these compounds is vital in ensuring good …

Use Of Wicking Geotextile To Dehydrate Road Embankments, Chuang Lin

Doctoral Dissertations

“Excess water within a pavement structure is the major cause of pavement deteriorations. A roadway is often constructed with soils compacted at the optimum water contents to achieve the best performance. After construction, the soil water content variation is controlled by the ambient environment. The base course aggregate is very sensitive to water content variations. Unfortunately, conventional drainage system can only drain gravity water, but not capillary water, and it cannot work under unsaturated conditions. Consequently, no matter how well the road is constructed, the water content is expected to increase with time and the excess water will inevitably accelerate …

Design And Characterization Of A Strong Positron Source At The Mstr Beam Port, Raed Atiah Alsulami

Doctoral Dissertations

“For many years, slow positron sources have found uses in diverse fields including medical physics, nuclear physics, biology, surface science, exotic atom research and space science. The purpose of this work is to design and optimize a reactor-based positron source at the Missouri University of Science and Technology Reactor (MSTR) beam port and quantify its intensity. Monte Carlo simulations using the MCNP6 code were used to model the positron production and moderation processes at the MSTR beam port. The thermal neutron flux at the beam port was determined experimentally and used in the source definition of the radiation transport simulations. …

Numerical Modeling Study Of A Neutron Depth Profiling (Ndp) System For The Missouri S&T Reactor, Mubarak Mohammed Albarqi

Doctoral Dissertations

”For decades, Neutron Depth Profiling has been used for the non-destructive analysis and quantification of boron in electronic materials and lithium in lithium ion batteries. NDP is one of the few non-destructive analytical techniques capable of measuring the depth profiles of light elements to depths of several microns with nanometer spatial resolution. The technique, however, is applicable only to a handful of light elements with large neutron absorption cross sections. This work discusses the possibility of coupling Particle Induced X-ray Emission spectroscopy with Neutron Depth Profiling to yield additional information about the depth profiles of other elements within a material. …

Volumetric Error Compensation For Industrial Robots And Machine Tools, Le Ma

Doctoral Dissertations

“A more efficient and increasingly popular volumetric error compensation method for machine tools is to compute compensation tables in axis space with tool tip volumetric measurements. However, machine tools have high-order geometric errors and some workspace is not reachable by measurement devices, the compensation method suffers a curve-fitting challenge, overfitting measurements in measured space and losing accuracy around and out of the measured space. Paper I presents a novel method that aims to uniformly interpolate and extrapolate the compensation tables throughout the entire workspace. By using a uniform constraint to bound the tool tip error slopes, an optimal model with …

Provenance, Redox Conditions, And Diagenesis Of Shales In Chang 7 Member Of Upper Triassic Yanchang Formation, Ordos Basin, China, Bin Sun

Doctoral Dissertations

“This study aims to decipher provenance, redox conditions, and burial history of shales in Chang 7 Member of Upper Triassic Yanchang Formation, Ordos Basin, China. The first paper discusses the origins of single-channeled, vertical, sinuous, and calcite-bitumen-filled cracks in the shales. Results show that in early diagenesis, unconsolidated mud was expanded open by escaping gases produced during organic matter maturation under hydrothermal influences. Calcite initially filled the cracks; bitumen and pyrite came in later and occupied the cracks in various ways. Compaction occurred next and folded the calcite- and bitumen-filled cracks into sinuous shapes. The second paper uses geochemical and …

Developing And Evaluating A Partition-Cavity Solar Thermochemical Reactor For Syngas Production Via Computational Fluid Dynamics, Han Zhang

Doctoral Dissertations

"Solar thermochemical processes are attractive since they have the advantages of storing solar energy as chemical fuels. In this dissertation, a partition-cavity solar thermochemical reactor was developed, and the heat and mass transfer of the solar thermochemical processes were numerically analyzed in this directly-irradiated reactor.

The reduction reaction of two-step CeO₂/CeO_2-δ solar redox process was investigated using the coupling of computational fluid dynamics (CFD) and discrete element method (DEM). The reduction rate was studied based on the catalyst textual properties and the reaction condition. The results revealed that the increase of catalyst specific surface area and the …