Digital Commons Network^™

Synthesis And Characterization Of Nanojars And Their Anion Binding Ability, Wisam Abdulabbas Flayyih Al Isawi

Dissertations

Inorganic anions are an important class of inherently negatively charged species. Anions such as sulfate (SO42–) and phosphates (H2PO4–, HPO42–) are ubiquitous in nature and biological systems, whereas chromate (CrO42–) and arsenates (H2AsO4–, HAsO42–) are environmental pollutants. Because of the high interest in the sequestration of anions from aqueous media, different methods have been explored to bind anions. Among these, the use of noncovalent interactions to encapsulate anions by organic and metal-organic host molecules is particularly attractive, because the reversibility of binding allows for the easy recovery of the extracted anion and the recycling of the anion extracting agent.

Nanojars …

Stressors And Coping Of Mexican American College Undergraduates, Jeanette Calvario Perales

Dissertations

Empirical literature indicates that current mental health practices with Mexican American college students are lacking. Mexican American undergraduates have unique challenges that need to be addressed by counselors within the university context and in community settings. This study addressed the dearth of empirical literature on stressors and coping strategies by exploring the experiences of Mexican American students at a predominately White institution (PWI) in the Midwest region of the United States. Through grounded theory, a theory was generated from multiple in-depth interviews using a comparative analysis process to enhance understanding of how Mexican American college undergraduates at PWIs cope with …

Mixture Of Functional Graphical Models, Qihai Liu

Dissertations

With the development of data collection technologies that use powerful monitoring devices and computational tools, many scientific fields are now obtaining more detailed and more complicatedly structured data, e.g., functional data. This leads to increasing challenges of extracting information from the large complex data. Making use of these data to gain insight into complex phenomena requires characterizing the relationships among a large number of functional variables. Functional data analysis (FDA) is a rapidly developing area of statistics for data which can be naturally viewed as a smooth curve or function. It is a method that changes the frame of data …

Historical Memory And Feminist Consciousness In Almudena Grandes’ Episodios De Una Guerra Interminable, Alba Fernández-Fernández

Dissertations

General Francisco Franco’s brutal dictatorship (1939-1975) was one of the darkest periods in Spain’s recent history. During this dictatorial regime, political detractors were mercilessly persecuted, tortured and massacred. In 1975, Franco died leaving the legacy of nearly four decades of repression and over 150,000 victims on his back. Spain then cautiously headed into a process of democratization, with fear and horror still etched on the country’s memory. While politicians promised a smooth transition to democracy, their insistence to look ahead meant Spaniards were asked to neglect the country’s painful past. No legal action was taken against those responsible for mass …

Oncolytic Tanapoxvirus Variants Expressing Mil-2 And Mccl-2 Regress Human Pancreatic Cancer Xenografts In Immunocompromised And Immunocompetent Cann.Cg-Foxn1Nu/Crl Nude Mice, Scott David Haller

Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is the fifth leading cause of cancer-related death in Western countries. The incidence of PDAC has increased over the last 40 years and is projected to be the second leading cause of cancer death by 2030. Despite aggressive treatment regimens, prognosis for patients diagnosed with PDAC is very poor; PDAC has the lowest 5-year survival rate for any form of cancer in the United States (US). PDAC cases are rarely detected in early stage when surgical resection can be performed and few, approximately 20%, are suitable for surgical resection which remains the only curative treatment when …

From Young To Old: The Effects Of Sedentary-Aging And Exercise Interventions On Structural Plasticity Of Lumbar Motor Neurons, Nmj, And Glial Cell Line-Derived Neurotrophic Factor Expression, Alberto Felipe Cintron-Colon

Dissertations

Neuromuscular weakness has been associated with age progression. A possible reason is a disconnection between muscle and neuron, causing components from both the central and peripheral nervous systems to deteriorate. Exercise, however, has beneficial effects for both muscle and nervous tissue, inducing neuroprotection. Neurotrophic factors are powerful regulators of neuronal maintenance and synaptic strength. Glial cell line-derived neurotrophic factor (GDNF) is a neurotrophic factor that has been shown to be a potent survival factor for somatic motor neurons that innervate skeletal muscle.

This study aims to evaluate changes in structural plasticity of motor neurons in the lumbar spinal cord and …

Mid To Late Neogene (5.9-3.7 Ma) Epeirogenic Uplift And Associated Ultramafic Volcanism, Canterbury Basin, New Zealand, Katherine Anne Dvorak

Dissertations

Cored marine sediments from Canterbury Basin Integrated Ocean Drilling Program (IODP) Expedition 317 shelf sites U1351, U1353, and upper slope Site U1352 have been resampled with emphasis on benthic foraminifera from the Late Eocene to Late Pliocene. These new data coupled with paleo water-depth and age data from the nearby Clipper-1 petroleum exploration well, are used to develop a 1-dimensional basin subsidence model for the Canterbury Basin. Our model indicates there was widespread epeirogenic uplift of 890  350m, in the mid-Neogene (5.9-3.7 million years ago), which took place during concomitant ultramafic volcanism. Close association of uplift and volcanism could …

Development Of Flexible Hybrid Electronics For Sterilization And Structural Health Monitoring Applications, Arnesh Kumar Bose

Dissertations

No abstract provided.

Model Predictive Controller Design For Internal Combustion Engines Based On The Second Law Of Thermodynamics, Muataz Abotabik

Dissertations

Energy resources depletion and worldwide strict emissions policies pose challenges that automotive manufacturers try to overcome through researching advanced powertrain technologies such as lean-burn gasoline, direct injection, homogeneous charge compression ignition engines, powertrain electrification, etc. Most of these developments have been focused on conventional internal combustion engines (ICE) emissions and performance enhancements. Most ICE control strategies are built based on the First Law of Thermodynamics (FLT) i.e., to deliver a specific load requirement, enhancing thermal efficiency, etc. The FLT doesn’t account for in-cylinder high temperature thermodynamics process irreversibilities that cause losses in the work potential; up to 25% of the …

One-Stage Blind Source Separation Via A Sparse Autoencoder Framework, Jason Anthony Dabin

Dissertations

Blind source separation (BSS) is the process of recovering individual source transmissions from a received mixture of co-channel signals without a priori knowledge of the channel mixing matrix or transmitted source signals. The received co-channel composite signal is considered to be captured across an antenna array or sensor network and is assumed to contain sparse transmissions, as users are active and inactive aperiodically over time. An unsupervised machine learning approach using an artificial feedforward neural network sparse autoencoder with one hidden layer is formulated for blindly recovering the channel matrix and source activity of co-channel transmissions. The BSS sparse autoencoder …

Optimizing Speed Profiles For Sustainable Train Operation With Wayside Energy Storage Systems, Leon A. Allen

Dissertations

Large hauling capability and low rolling resistance has put rail transit at the forefront of mass transportation mode sustainability in terms of congestion mitigation and energy conservation. As such, rail vehicles are one of the least energy-intensive modes of transportation and least environmentally polluting. Despite, these positives, improper driving habits and wastage of the braking energy through dissipation in braking resistors result in unnecessary consumption, extra costs to the operator and increased atmospheric greenhouse gas emissions.

This study presents an intelligent method for the optimization of the number and locations of wayside energy storage system (WESS) units that maximize the …

Planning Methodology For Alternative Intersection Design And Selection, Liran Chen

Dissertations

The recent publication of the 6th Edition of the Highway Capacity Manual included a chapter on Ramp Terminals and Alternative Intersections that introduces various alternative intersection designs and assesses the performance of Median U-turn, Restricted crossing U-turn and Displaced left-turn intersections. Missing from the literature is an alternative intersection selection tool for identifying whether an alternative intersection would be successful under local conditions. With limited information of organized alternative intersection research, most planners must rely heavily on their personal judgement while selecting the most suitable intersection designs. As appealing as alternative intersections are, there is no comprehensive methodology for planners …

Understanding The Voluntary Moderation Practices In Live Streaming Communities, Jie Cai

Dissertations

Harmful content, such as hate speech, online abuses, harassment, and cyberbullying, proliferates across various online communities. Live streaming as a novel online community provides ways for thousands of users (viewers) to entertain and engage with a broadcaster (streamer) in real-time in the chatroom. While the streamer has the camera on and the screen shared, tens of thousands of viewers are watching and messaging in real-time, resulting in concerns about harassment and cyberbullying. To regulate harmful content—toxic messages in the chatroom, streamers rely on a combination of automated tools and volunteer human moderators (mods) to block users or remove content, which …

Waves And Oscillations In A Sunspot: Observations And Modeling Of Noaa Ar 12470, Yi Chai

Dissertations

Waves and oscillations are important solar phenomena not only because they can propagate and dissipate energy in the chromosphere, but also because they carry information about the structure of the atmosphere in which they propagate. Among these phenomena, the one of the most interesting ones occurs in the sunspot umbra. In this area, continuously propagating magnetohydrodynamic (MHD) waves generated from below the photosphere create the famous 3-minute sunspot umbral oscillations that affect the line profile of spectral lines due to temperature, density, and velocity changes of the plasma in the region. In the past decades, numerous observations and models have …

Nondestructive Evaluation Of 3d Printed, Extruded, And Natural Polymer Structures Using Terahertz Spectroscopy And Imaging, Alexander T. Clark

Dissertations

Terahertz (THz) spectroscopy and imaging are considered for the nondestructive evaluation (NDE) of various three-dimensional (3D) printed, extruded, and natural polymer structures. THz radiation is the prime candidate for many NDE challenges due to the added benefits of safety, increased contrast and depth resolution, and optical characteristic visualization when compared to other techniques. THz imaging, using a wide bandwidth pulse-based system, can evaluate the external and internal structure of most nonconductive and nonpolar materials without any permanent effects. NDE images can be created based on THz pulse attributes or a material’s spectroscopic characteristics such as refractive index, attenuation coefficient, or …

Investigation Of Topological Phonons In Acoustic Metamaterials, Wenting Cheng

Dissertations

Topological acoustics is a recent and intense area of research. It merges the knowledge of mathematical topology, condensed matter physics, and acoustics. At the same time, it has been pointed out that quasiperiodicity can greatly enhance the periodic table of topological systems. Because quasiperiodic patterns have an intrinsic global degree of freedom, which exists in the topological space called the hull of a pattern, where the shape traced in this topological space is called the phason. The hull augments the physical space, which opens a door to the physics of the integer quantum Hall effect (IQHE) in arbitrary dimensions. In …

Improving The Performance And Evaluation Of Computer-Assisted Semen Analysis, Ji-Won Choi

Dissertations

Semen analysis is performed routinely in fertility clinics to analyze the quality of semen and sperm cells of male patients. The analysis is typically performed by trained technicians or by Computer-Assisted Semen Analysis (CASA) systems. Manual semen analysis performed by technicians is subjective, time-consuming, and laborious, and yet most fertility clinics perform semen analysis in this manner. CASA systems, which are designed to perform the same tasks automatically, have a considerable market share, yet many studies still express concerns about their accuracy and consistency. In this dissertation, the focus is on detection, tracking, and classification of sperm cells in semen …

A Self-Learning Intersection Control System For Connected And Automated Vehicles, Ardeshir Mirbakhsh

Dissertations

This study proposes a Decentralized Sparse Coordination Learning System (DSCLS) based on Deep Reinforcement Learning (DRL) to control intersections under the Connected and Automated Vehicles (CAVs) environment. In this approach, roadway sections are divided into small areas; vehicles try to reserve their desired area ahead of time, based on having a common desired area with other CAVs; the vehicles would be in an independent or coordinated state. Individual CAVs are set accountable for decision-making at each step in both coordinated and independent states. In the training process, CAVs learn to minimize the overall delay at the intersection. Due to the …

Local Learning Algorithms For Stochastic Spiking Neural Networks, Bleema Rosenfeld

Dissertations

This dissertation focuses on the development of machine learning algorithms for spiking neural networks, with an emphasis on local three-factor learning rules that are in keeping with the constraints imposed by current neuromorphic hardware. Spiking neural networks (SNNs) are an alternative to artificial neural networks (ANNs) that follow a similar graphical structure but use a processing paradigm more closely modeled after the biological brain in an effort to harness its low power processing capability. SNNs use an event based processing scheme which leads to significant power savings when implemented in dedicated neuromorphic hardware such as Intel’s Loihi chip.

This work …

Entrepreneurship And Heterogeneity Among Firms' Strategies: Three Essays, Xi Zhang

Dissertations

The first essay of this dissertation focuses on the entrepreneurship survival in the early stage, during which time an entrepreneur plays the game at the "edge of chaos" and improvises in real-time to learn the strategic playing field. It examines the social networks of entrepreneurs and the impact on new venture survival. Specifically, it explores how the entrepreneurs' social connections with other entrepreneurs and their types of employment differentially affect survival during the different stages of the entrepreneurial journey in the United States and India. Using the Global Entrepreneurship Monitor (GEM) dataset, this study documents not only how the social …

Numerical Methods For Optimal Transport And Optimal Information Transport On The Sphere, Axel G. R. Turnquist

Dissertations

The primary contribution of this dissertation is in developing and analyzing efficient, provably convergent numerical schemes for solving fully nonlinear elliptic partial differential equation arising from Optimal Transport on the sphere, and then applying and adapting the methods to two specific engineering applications: the reflector antenna problem and the moving mesh methods problem. For these types of nonlinear partial differential equations, many numerical studies have been done in recent years, the vast majority in subsets of Euclidean space. In this dissertation, the first major goal is to develop convergent schemes for the sphere. However, another goal of this dissertation is …

Effect Of Process Control Agents Used In Mechanochemical Synthesis On Properties Of The Prepared Composite Reactive Materials, Mehnaz Mursalat

Dissertations

The study explores synthesis and reactivity of new reactive materials prepared by ball milling. High-energy ball milling became a ubiquitous mechano-chemical tool to manufacture diverse powders, from pharmaceuticals or foods to alloys to new solid rocket propellants. It enabled a dramatic expansion of the range of chemical compositions obtainable; however, it did not so far, allowed one to fine-tune morphology or interfaces in the generated powders. It is shown in this work how different process control agents (PCAs) can serve to tune the powder morphology and reactivity. Commonly used as lubricants and cooling agents during milling, liquid PCAs can be …

Optimization Opportunities In Human In The Loop Computational Paradigm, Dong Wei

Dissertations

An emerging trend is to leverage human capabilities in the computational loop at different capacities, ranging from tapping knowledge from a richly heterogeneous pool of knowledge resident in the general population to soliciting expert opinions. These practices are, in general, termed human-in-the-loop (HITL) computations.

A HITL process requires holistic treatment and optimization from multiple standpoints considering all stakeholders: a. applications, b. platforms, c. humans. In application-centric optimization, the factors of interest usually are latency (how long it takes for a set of tasks to finish), cost (the monetary or computational expenses incurred in the process), and quality of the completed …

Towards Practicalization Of Blockchain-Based Decentralized Applications, Songlin He

Dissertations

Blockchain can be defined as an immutable ledger for recording transactions, maintained in a distributed network of mutually untrusting peers. Blockchain technology has been widely applied to various fields beyond its initial usage of cryptocurrency. However, blockchain itself is insufficient to meet all the desired security or efficiency requirements for diversified application scenarios. This dissertation focuses on two core functionalities that blockchain provides, i.e., robust storage and reliable computation. Three concrete application scenarios including Internet of Things (IoT), cybersecurity management (CSM), and peer-to-peer (P2P) content delivery network (CDN) are utilized to elaborate the general design principles for these two main …

Understanding The Interfacial Processes Of Reactive Nanobubbles Toward Agricultural Applications, Xiaonan Shi

Dissertations

There is a growing interest in nanobubble (NB) technology because of its diverse applications (e.g., detergent-free cleaning, water aeration, ultra-sound imaging and intracellular drug delivery, and mineral processing). NBs have a higher efficiency of mass transfer compared to bulk scale bubbles due to the high specific surface areas. The high specific surface also facilitates physical adsorption and chemical reactions in the gas liquid interface. Furthermore, the collapse of NBs creates shock waves and the formation of hydroxyl radicals (OH).

However, it remains elusive why or how NBs are stabilized in water and particularly, the states of internal pressures of NBs …

Representation Learning In Finance, Ajim Uddin

Dissertations

Finance studies often employ heterogeneous datasets from different sources with different structures and frequencies. Some data are noisy, sparse, and unbalanced with missing values; some are unstructured, containing text or networks. Traditional techniques often struggle to combine and effectively extract information from these datasets. This work explores representation learning as a proven machine learning technique in learning informative embedding from complex, noisy, and dynamic financial data. This dissertation proposes novel factorization algorithms and network modeling techniques to learn the local and global representation of data in two specific financial applications: analysts’ earnings forecasts and asset pricing.

Financial analysts’ earnings forecast …

Outdoor Operations Of Multiple Quadrotors In Windy Environment, Deepan Lobo

Dissertations

Coordinated multiple small unmanned aerial vehicles (sUAVs) offer several advantages over a single sUAV platform. These advantages include improved task efficiency, reduced task completion time, improved fault tolerance, and higher task flexibility. However, their deployment in an outdoor environment is challenging due to the presence of wind gusts. The coordinated motion of a multi-sUAV system in the presence of wind disturbances is a challenging problem when considering collision avoidance (safety), scalability, and communication connectivity. Performing wind-agnostic motion planning for sUAVs may produce a sizeable cross-track error if the wind on the planned route leads to actuator saturation. In a multi-sUAV …

Periodic Fast Multipole Method, Ruqi Pei

Dissertations

Applications in electrostatics, magnetostatics, fluid mechanics, and elasticity often involve sources contained in a unit cell C, centered at the origin, on which periodic boundary condition are imposed. The free-space Green’s functions for many classical partial differential equations (PDE), such as the modified Helmholtz equation, are well-known. Among the existing schemes for imposing the periodicity, three common approaches are: direct discretization of the governing PDE including boundary conditions to yield a large sparse linear system of equations, spectral methods which solve the governing PDE using Fourier analysis, and the method of images based on tiling the plane with copies of …

Nystrom Methods For High-Order Cq Solutions Of The Wave Equation In Two Dimensions, Erli Wind-Andersen

Dissertations

An investigation of high order Convolution Quadratures (CQ) methods for the solution of the wave equation in unbounded domains in two dimensions is presented. These rely on Nystrom discretizations for the solution of the ensemble of associated Laplace domain modified Helmholtz problems. Two classes of CQ discretizations are considered: one based on linear multistep methods and the other based on Runge-Kutta methods. Both are used in conjunction with Nystrom discretizations based on Alpert and QBX quadratures of Boundary Integral Equation (BIE) formulations of the Laplace domain Helmholtz problems with complex wavenumbers. CQ in conjunction with BIE is an excellent candidate …

Design And Control Of Next-Generation Uavs For Effectively Interacting With Environments, Caiwu Ding

Dissertations

In this dissertation, the design and control of a novel multirotor for aerial manipulation is studied, with the aim of endowing the aerial vehicle with more degrees of freedom of motion and stability when interacting with the environments. Firstly, it presents an energy-efficient adaptive robust tracking control method for a class of fully actuated, thrust vectoring unmanned aerial vehicles (UAVs) with parametric uncertainties including unknown moment of inertia, mass and center of mass, which would occur in aerial maneuvering and manipulation. The effectiveness of this method is demonstrated through simulation. Secondly, a humanoid robot arm is adopted to serve as …