Digital Commons Network^™

Theoretical Determination Of The Yield Curve For Unsaturated Soils, Sara Fayek

Doctoral Dissertations

"An important step to developing a good understanding of the behavior of unsaturated soils is to adopt a formal and simple constitutive framework and to conduct high-quality and short-time experiments. Barcelona Basic Model (BBM) was the first elastoplastic constitutive model for unsaturated soils. The yield curve, which separates the elastic region from the elastoplastic region, is an important aspect of constitutive modeling for unsaturated soils. Most concepts for unsaturated soils were developed based upon the results from suction-controlled triaxial (SCTX) tests. Though, the SCTX tests on unsaturated soils are costly, time-consuming, and laborious, and their results are questionable. This study …

Application Of Signal Processing Techniques For Health Monitoring And Damage Detection Of Memorial Bridge, Forouzandeh Mazaherimeybodi

Doctoral Dissertations

Aging and deterioration and damage to infrastructure elements such as bridges, roads, and tunnels, are some of the biggest concerns to the uninterrupted operation of the US transportation network.Structural health monitoring (SHM) is one of the most powerful tools proposed by the civil engineering research community as an economical and objective method for civil infrastructure management and condition assessment. A typical SHM process consists of continuous or periodic estimations of structural parameters based on a sensor network, feature extraction, and statistical modeling for feature classification to detect any damage that occurred to the structure. Due to the evolution of building …

Operads, Symmetric Monoidal Categories, And Localizations, Emma Catherine Phillips

Doctoral Dissertations

An operad can be thought of as a collection of operations, each with a finite number of inputs and a single output, along with a composition rule. We prove that the category of operads in an appropriate concrete symmetric monoidal category V is equivalent to a subcategory of symmetric monoidal categories enriched in V. Though versions of this result have appeared previously in the literature, we prove that a more restrictive subcategory is needed to construct the equivalence. Our subcategory has the advantage that its objects share important properties with the historical precursor to operads, PROPs.

We also review a …

Substorm Onset Related Ultra Low Frequency Waves, Michelle Salzano

Doctoral Dissertations

Ultra Low Frequency (ULF) waves are geomagnetic perturbations in the mHz to Hz range that contribute both directly and indirectly to particle losses in the radiation belts. Pi1B waves are ULF broadband bursts in the Pi1 range that are well correlated with substorm onset. Intervals of Pulsations of Diminishing Periods (IPDPs) are a sub-type of ULF Electromagnetic Ion Cyclotron (EMIC) waves that are characterized by an increase in frequency over time. IPDPs are thought to be generated by particles injected at substorm onset. One of the main instruments used to identify ULF waves is the searchcoil magnetometer. In this dissertation, …

Answering Topical Information Needs Using Neural Entity-Oriented Information Retrieval And Extraction, Shubham Chatterjee

Doctoral Dissertations

In the modern world, search engines are an integral part of human lives. The field of Information Retrieval (IR) is concerned with finding material (usually documents) of an unstructured nature (usually text) that satisfies an information need (query) from within large collections (usually stored on computers). The search engine then displays a ranked list of results relevant to our query. Traditional document retrieval algorithms match a query to a document using the overlap of words in both. However, the last decade has seen the focus shifting to leveraging the rich semantic information available in the form of entities. Entities are …

Environmental Implications Of Ubiquitous Dicarboxylic Acid Aerosol And Biomass Burning Generated Reactive Nitrogen, Jackson Hart Kaspari

Doctoral Dissertations

Aerosols impact our lives in many different ways, including the health of our species,visibility and the global climate. In terms of climate effects, large uncertainty still exists surrounding the combined influence of aerosols on the Earth’s radiative budget. This highlights the importance of research that seeks to better understand atmospheric aerosols and associated gas phase compounds, as advances in the field will allow for the production of more accurate climate models. In laboratory studies, great variability in reported deliquescence relative humidity (DRH) warrants the need for new methods of analysis. A custom built electrobalance with variable active particle humidity control …

Self-Validated Ensemble Modelling, Trent Lemkus

Doctoral Dissertations

An important objective when performing designed experiments is to build models that predict future performance of a system in study; e.g. predict future yields of a bio-process used to manufacture therapeutic proteins. Because experimentation is costly experimental designs are structured to be efficient in terms of the number of trials while providing substantial information about the behavior of the physical system. The strategy to build accurate predictive models in larger data sets is to partition the data into a training set, used to fit the model, and a validation set to access prediction performance. Models are selected that have the …

Narratives Of Becoming: Conceptualization Of Teacher Identity Through The Experiences Of Educators From Racially, Linguistically, And Culturally Minoritized Backgrounds, Sumeyra Gok Gulmezoglu

Doctoral Dissertations

Teacher education programs are predominantly White spaces with their faculty, teacher candidates, curriculum, and practices. In these spaces, the experiences of teacher candidates from minoritized backgrounds can be alienating and their voices can be overlooked or silenced. In three interrelated but distinct studies, this research aims to highlight the experiences and perspectives of educators from minoritized racial, ethnic, and linguistic backgrounds as they are conceptualizing their professional identities as educators. These three studies are narratives of becoming as they explore conceptualization of teacher identity through three different narrative methods namely autoethnography, counterstories, and narrative inquiry. Although each study has its …

Estimation And Consequences Of Asymmetric Dispersal On The Genetics Of Coastal Marine Organisms In 1-D Habitats, Kyle Teller

Doctoral Dissertations

Estimation and Consequences of Asymmetric Dispersal on the Genetics of Coastal Marine Organisms in 1-D Habitats

Many natural populations have a dispersal that is biased in one direction (asymmetric dispersal), due to physical factors in the environment such as currents in the ocean that transport larvae or winds that carry seeds. These physical factors create a preferred direction for offspring to be carried (the “downstream” direction). When there is asymmetric dispersal there are two parameters that define the dispersal distance, the mean downstream distance, and the standard deviation of dispersal distances. This present research analyzes the effects of the mean …

Representation Learning On Heterogeneous Spatiotemporal Networks, Dakshak Keerthi Chandra

Doctoral Dissertations

“The problem of learning latent representations of heterogeneous networks with spatial and temporal attributes has been gaining traction in recent years, given its myriad of real-world applications. Most systems with applications in the field of transportation, urban economics, medical information, online e-commerce, etc., handle big data that can be structured into Spatiotemporal Heterogeneous Networks (SHNs), thereby making efficient analysis of these networks extremely vital. In recent years, representation learning models have proven to be quite efficient in capturing effective lower-dimensional representations of data. But, capturing efficient representations of SHNs continues to pose a challenge for the following reasons: (i) Spatiotemporal …

Peritectic Behavior Detection And Prediction In Fe-C-Si-Mn-Al System, Damilola Balogun

Doctoral Dissertations

"The non-uniformity of shell growth in the continuous casting of peritectic steels constitutes a major barrier to the commercial production of many steel grades such as Advanced high strength steels (AHSS), transformation induced plasticity (TRIP) steels, abrasion-resistant steels, advanced armor plate steels, and many newly proposed steel grades that contain high levels of silicon, manganese, and aluminum.

The shell growth non-uniformity experienced in the continuous casting of peritectic steels results in the formation of defects in the as-cast slab and therefore increases the operating risk from cast aborts and breakouts. The ability to predict and avoid peritectic behavior at the …

Design And Synthesis Of Purine Based Neuroprotectors And Novel Synthetic Methods For The Trifluoromethylation Of Aldehyde Hydrazones, Puspa Aryal

Doctoral Dissertations

"Purine-derived compounds are widely investigated as cyclin-dependent kinase inhibitors that have broad applications in the design of pharmaceuticals for treating diseases, such as diabetes, atherosclerosis, and cancers. Towards the goal of effective AGE-inhibitors, and neuroprotector compounds we have synthesized a series of novel purine-based triazoles and investigated their neuroprotective effects, using SHSY-3Y human neuroblastoma cell line. Through these studies, we have identified purine-based neuroprotector compounds that favorably modulate oxidative stress induced by the Fenton reaction-generated reactive oxygen species (ROS).

The C(sp²−H)-trifluoromethylation of hydrazones would give access to the αtrifluoromethylated hydrazones that can serve as intermediates in the synthesis …

Deep Learning-Based Surrogate Models For Post-Earthquake Damage Assessment, Xinzhe Yuan

Doctoral Dissertations

"Seismic damage assessment is a critical step to enhance community resilience in the wake of an earthquake. This study aims to develop deep learning-based surrogate models for widely used fragility curves to achieve more accurate and rapid assessment in practice. These surrogate models are based on artificial neural networks trained from the labelled ground motions whose resulting damage classes on targeted structures are determined by nonlinear time history analyses. The development of various surrogate models is progressed in four phases. In Phase I, the multilayer perceptron (MLP) is used to develop multivariate seismic classifiers with up to 50 hand-crafted intensity …

Effects Of Vacancies And Electron Temperature On The Electron Phonon Coupling In Cubic Silicon Carbide And Their Connection To The Inelastic Thermal Spike, Salah Al-Smairat

Doctoral Dissertations

“The electron-phonon interaction is an important interaction in many solids as it influences transport phenomena and related quantities such as the electrical and thermal conductivities, especially in nuclear and space applications. The importance of the electron-phonon interaction in primary damage production in 3C-SiC is the subject of this research.

The electron-phonon coupling factor was calculated using a hybrid Density Functional Perturbation Theory - Classical Electron Gas model. The coupling factor was calculated as a function of electron temperature in pristine and defective 3C-SiC, and relaxed defective cells. The electron-phonon coupling is found to depend strongly on the electronic temperature and …

Determining Thermal Properties Via Parameter Estimation Of A One-Dimensional, Analytical Model, Lauren B. Tomanek

Doctoral Dissertations

“In thermal applications, thermal conductivity is used to predict how well a material conducts heat. The accuracy of the magnitude of the thermal conductivity becomes increasingly essential to optimize part geometry. Thermal conductivity can vary significantly from the nominal value due to post-processing. The ASTM standards available to measure thermal conductivity are challenging to reproduce because of the insulated and prescribed temperature boundary conditions that are needed. The research introduces two new methods for estimating thermal conductivity that deliver the same accuracy as the existing ASTM standards and are easier to implement. The methods account for losses in the heating …

Development Of An Interactive Robot For Overground Physical Human-Robot Interaction, Sambad Regmi

Doctoral Dissertations

"The overground interactive robots are potentially beneficial for humans in various areas, such as overground rehabilitation therapies and robotic interactive assistance. However, it is unclear what the expectations and challenges are for a robot to be physically interactive with a human during overground tasks, such as a robot helping an older adult walk. To develop such a robot, one must first build a clear understanding of how the human motor intent is communicated when interacting with another agent. Specifically, how do humans understand the leader’s intention when being led?

Based on previous works, we hypothesized that humans modulate their arm …

Depositional Conditions, Stratigraphic Evolution, And Allo- And Autogenic Controls Of Lower Permian Non-Marine Carbonate Rocks, Lucaogou Low-Order Cycle, Bogda Mountains, Nw China, Yiran Lu

Doctoral Dissertations

"The overall objective of this study is to interpret the depositional conditions of lacustrine carbonate deposits of the lower Permian Lucaogou low-order cycle in the greater Turpan-Junggar continental rift basin, NW China. The depositional environments of ten carbonate lithofacies in the Tarlong-Taodonggou half graben and the Zhaobishan section were interpreted. Allo- and autogenic factors were identified. They controlled characteristics and distribution pattern of carbonate deposits in regional and local scale, respectively. Allogenic factors include the amount and direction of regional siliciclastic input, basin geometry, cyclic humidity/aridity oscillation, temperature, and regional tectonics. Autogenic factors include local siliciclastic input, local topography, local …

Mediating Language Fluency Development: An Action Research Study In A High-School Ap Chinese Second-Or-Foreign-Language Task-Based Language Teaching Classroom, Jing Liang

Doctoral Dissertations

Fluency development is critical in language learning; however, the teacher’s role as a mediator in a learner’s fluency development rarely has been explored in Task-Based Language Teaching (TBLT) classrooms. This study investigated how a teacher, as the human mediator who can be certain that stimuli in the learning environment will be available and benefit the learners, implemented mediation under the guidance of Mediated Learning Experience (MLE) theory in aiding learners’ speaking cognitive and utterance fluency development in one AP Chinese high-school TBLT classroom in the Bay Area. MLE theory, developed by psychologist Reuven Feuerstein, provided a mediation framework for this …

Effects Of Teaching Argument To First-Year Community-College Students Using A Structural And Dialectical Approach, Sharon Radcliff

Doctoral Dissertations

The purpose of this study was to measure to what extent an experimental method of teaching argument incorporating elements from both Toulmin’s (2004) structural approach and Walton’s (2013) dialectical approach effects first-year college students’ ability to write strong arguments. This experimental instruction used critical questioning as a strategy in building a strong argument, incorporating alternative viewpoints, and creating a dialogue between claims and counterclaims, backed logically by verifiable evidence from reliable sources.

Using the Analytic Scoring Rubric of Argumentative Writing (ASRAW; Stapleton & Wu, 2015) that includes the argument elements of claims, data, counterclaim, counterclaim data, rebuttal claim, and rebuttal …

Cuentos Criollos: Colombian Internally Displaced Families As Knowledge Producers, Liliana Salazar De Deck

Doctoral Dissertations

Colombia continues to report the highest number of internally displaced people (IDPs) with over eight million registered in 2021 (UNHCR, 2021). The majority of the internally displaced people are campesinos, AfroColombians, and members of Indigenous communities. Historically, people in these demographic groups have been excluded from political participation and wealth accumulation, and their identities are minoritized (Bello, 2003). Urban schools have become contact zones (Pratt, 1991) for internally displaced families and various economic, social, and political discourses attempt to explore and explain their experiences. However, the voices of the families themselves are not often found within this body of scholarship. …

"My Body Goes Numb A Lot Of The Time": Examining High School Student-Athlete Experiences Using Youth Participatory Action Research And Embodied Culturally Relevant Pedagogy, Gabriela Elizabeth Holmes

Doctoral Dissertations

For many students, the classroom represents a place of oppression, stress, and routine, in which their voices are silenced and they are expected to sit still, listen, take notes, and regurgitate the arbitrary information their teachers share (Freire, 1970/2000; Robinson & Aronica, 2015). Conversely, for many youth, sports are a source of joy, self-expression, creativity, and empowerment that naturally capture their interest and engagement (Duncan-Andrade, 2010; Spooner, 2002). Unfortunately, our education system fails to utilize the passion student-athletes demonstrate for sports to motivate them in the classroom. The purpose of this study is to explore the experiences of high school …

The Utilization And Loss Of Available Energy In Aerospace Systems, Mohammad Abbas

Doctoral Dissertations

“Theoretical principles and analytical methodology for the control volume-based energy availability methodology for aerospace vehicles are developed; applications are made to jet-propelled and rocket-propelled vehicles as well as to stand-alone engine systems. Energy availability utilization characteristics of a modeled turbojet engine are studied across a wide range of operating conditions of throttle setting, flight altitude, and flight Mach number. The method is also extended to consider jet-powered vehicles. Fundamental principles regarding entropy generation and energy availability are developed, including directly linking entropy generation and maximum range and endurance of a powered aircraft. Theory and application of the energy utilization methodology …

Corrosion Protection Mechanisms Of Trivalent Chromium Based Passivations On Γ-Znni Coated Al6061-T6 Alloy, Kevin Foster

Doctoral Dissertations

“The role of cobalt in trivalent chromium passivations (TCPs) to improve corrosion resistance of γ-ZnNi coated steel and aluminum is based on its effect on hexavalent chromium content in the passive layer. Investigations of both a cobalt-containing and cobalt-free TCP on SAE 1008 steel indicated that both passivations protect well for up to 1000 hours in neutral salt spray exposure (SSE). A repetition on Al 6061-T6 alloy indicated that TCP performed much better than cobalt-free TCP implicating the underlying substrate. Optical and electron micrographs indicated physical changes such as crack thickness, crack density, passivation porosity, and passivation thickness existed between …

Numerical Simulation Study Of Gel Treatment For Conformance Control From Lab To Field, Jianqiao Leng

Doctoral Dissertations

“Gel treatment has been widely applied to control reservoir conformance and thus improve the sweep efficiency of injection fluids. Quite a few numerical simulations have been conducted to investigate the factors impacting gel treatment and assist to optimize treatment design and predict the performance. However, there exists significant barrier between the simulation approaches and lab experiments. In this study, two comprehensive reviews have been conducted to identify the gaps between lab and current simulations for in-situ polymer treatment and preformed particle gel treatment, separately.

Based on the identified gaps, the effect of a few major factors which are very important …

The Kanarra Fold-Thrust System -- The Leading Edge Of The Sevier Fold-Thrust Belt, Southwest Utah, William Joseph Michael Chandonia

Doctoral Dissertations

“The Jurassic to Eocene Sevier fold-thrust belt is the subject of continued scientific curiosity in tectonics, stratigraphy, and industry. Understanding its development in southwest Utah is hindered in part due to the multiple origins proposed for the Kanarra anticline, a major leading edge structure -- a drag fold along the Hurricane fault, Laramide monocline, Sevier fault propagation fold, or a combination of these -- which have confused its tectonic significance and regional context. This confusion results from the structural complexity of its exposed eastern limb, as well as displacement and burial of its crest and western limb beneath Neogene sediments …

Scale Formation, Properties And De-Scaling In Steelmaking, Richard Osei

Doctoral Dissertations

During continuous castings, reheating, and hot rolling, slab surfaces are exposed to atmospheres containing oxidizing gases which results in scale formation. Inefficient removal of the formed scale during reheating affects product surface quality. The effect of steel composition and operating parameters on scale formation and scale removal efficiencies were investigated. Experimental investigations were carried out using a thermogravimetric (TGA) apparatus designed to replicate the combustion gas atmosphere and temperature in actual industrial slab reheat furnaces. Report on oxidation kinetics, scale structure and properties, and descaling were conducted on laboratory cast and industrial samples. Different characterization techniques were used to analyze …

Characterization Of High Cycle Fatigue And Laser-Aided Machining And Polishing Of Additively Manufactured Materials, Mohammad Masud Parvez

Doctoral Dissertations

“Additive manufacturing (AM) and laser-aided machining and polishing (LAMP) of materials are emerging manufacturing processes both for research and industrial sectors. The AM process can manufacture near-net-shape parts with complex geometries. Meanwhile, the LAMP process integrated with an AM system offers a high processing rate, minimum heat-affected zone, and easily adjustable process parameters during machining and polishing. In mechanical properties characterization of AM metals and alloys, fatigue is a vitally important test method to understand the behavior of materials in cycling loading and unloading circumstances since most mechanical failures of structures are due to fatigue. To characterize AM metal fatigue …

Theoretical And Experimental Application Of Neural Networks In Spaceflight Control Systems, Pavel Galchenko

Doctoral Dissertations

“Spaceflight systems can enable advanced mission concepts that can help expand our understanding of the universe. To achieve the objectives of these missions, spaceflight systems typically leverage guidance and control systems to maintain some desired path and/or orientation of their scientific instrumentation. A deep understanding of the natural dynamics of the environment in which these spaceflight systems operate is required to design control systems capable of achieving the desired scientific objectives. However, mitigating strategies are critically important when these dynamics are unknown or poorly understood and/or modelled. This research introduces two neural network methodologies to control the translation and rotation …

Variational Data Assimilation For Two Interface Problems, Xuejian Li

Doctoral Dissertations

“Variational data assimilation (VDA) is a process that uses optimization techniques to determine an initial condition of a dynamical system such that its evolution best fits the observed data. In this dissertation, we develop and analyze the variational data assimilation method with finite element discretization for two interface problems, including the Parabolic Interface equation and the Stokes-Darcy equation with the Beavers-Joseph interface condition. By using Tikhonov regularization and formulating the VDA into an optimization problem, we establish the existence, uniqueness and stability of the optimal solution for each concerned case. Based on weak formulations of the Parabolic Interface equation and …

Advances And Applications In High-Dimensional Heuristic Optimization, Samuel Alexander Vanfossan

Doctoral Dissertations

“Applicable to most real-world decision scenarios, multiobjective optimization is an area of multicriteria decision-making that seeks to simultaneously optimize two or more conflicting objectives. In contrast to single-objective scenarios, nontrivial multiobjective optimization problems are characterized by a set of Pareto optimal solutions wherein no solution unanimously optimizes all objectives. Evolutionary algorithms have emerged as a standard approach to determine a set of these Pareto optimal solutions, from which a decision-maker can select a vetted alternative. While easy to implement and having demonstrated great efficacy, these evolutionary approaches have been criticized for their runtime complexity when dealing with many alternatives or …