Digital Commons Network^™

Extraction, Property, And Rights In Southeastern Arabian Seascapes C.1820–Present, Scott Erich

Dissertations, Theses, and Capstone Projects

This dissertation is a historical and ethnographic examination of fish, pearl, sponge, and oil extraction in the Persian Gulf and Gulf of Oman. These waters, which were fished and labored upon in much of the same way for millennia, have, in the last two centuries, undergone a sea change. Regimes of property and rights have transformed the ocean from a wild and undifferentiated space into a place which is enclosed, privatized, industrially fished, drilled, and otherwise despoiled. This dissertation, building on recent works in environmental history, Indian Ocean studies, and legal and economic anthropology, probes the many cultural, religious, social, …

The Role Of Nuclear Quantum Effects In Supercooled Water And Amorphous Ice, Ali H. Eltareb

Dissertations, Theses, and Capstone Projects

Water is one of the most important substances on Earth and plays a fundamental role in numerous scientific and engineering applications. Interestingly, water behaves much differently than other liquids. For example, water shows an anomalous density maximum at 277 K, the solid phase (ice) is less denser than the liquid, and its thermodynamic response functions, such as the specific heat C_P and isothermal compressibility κ_T, also increase anomalously upon cooling. In the glassy state, water can exist in two different forms, low-density and high-density amorphous ice (LDA and HDA). While water has been scrutinized for many centuries, …

Phase Transitions And Thermal Stability Of The Magnetic Dual Chiral Density Wave Phase In Cold, Dense Qcd, William G. Gyory

Dissertations, Theses, and Capstone Projects

The correct description of strongly interacting matter at extreme densities and low temperatures remains poorly understood. We analyze the magnetic dual chiral density wave (MDCDW) phase, an inhomogeneous chiral condensate that arises in cold, dense quark matter in a magnetic field. We first review the background theory and derive the free energy of the condensate. Then we show how the phase transitions can be studied using a generalized Ginzburg-Landau expansion, and we derive a convenient all-orders formula for the coefficients. Using these tools, we compute the order parameters, critical temperature, and threshold temperature over a range of chemical potentials and …

The Development Of Novel Radioscandium And Hydroxypyridinonate Based Radiopharmaceuticals, Michael Phipps

Dissertations, Theses, and Capstone Projects

The use of radiometals in radiopharmaceutical development has drastically increased over the last decade, owed in part to the diverse chemistry and emission characteristics of the radiometals, which allow chemists to create a toolbox of agents to better tailor patient care. Challenges with the use of radiometals include the selection of the metal and the development of optimized chelators to cover the diverse chemistry of the metals which make up the majority of the periodic table. Scandium is the first transition metal and has multiple radioisotopes whose emission characteristics have potential application in medicine. 3,4,3-LI(1,2-HOPO) is a chelator whose denticity, …

Quantifying Temperature-, Pressure-, And Nuclear Quantum Effects On Hydrophobic And Hydrophilic Water-Mediated Interactions, Justin T. Engstler

Dissertations, Theses, and Capstone Projects

Water-mediated interactions (WMIs) are responsible for diverse processes in aqueous solutions, including protein folding and nanoparticle aggregation. WMI may be affected by changes in temperature and pressure, and hence, they can alter chemical/physical processes that occur in aqueous environments. Traditionally, attention has been focused on hydrophobic interactions while, in comparison, the role of hydrophilic and hybrid (hydrophobic–hydrophilic) interactions have been mostly overlooked. Here, we study the role of T and P on the WMI between nanoscale (i) hydrophobic–hydrophobic, (ii) hydrophilic–hydrophilic, and (iii) hydrophilic–hydrophobic pairs of (hydroxylated/non-hydroxylated) graphene-based surfaces. We find that hydrophobic, hydrophilic, and hybrid interactions are all sensitive to …

Nonlinear Processes In Room Temperature Exciton-Polaritons, Prathmesh Deshmukh

Dissertations, Theses, and Capstone Projects

Strong light-matter coupling in solid state systems is an intriguing process that allows one to exploit the advantages of both light and matter. In this context, microcavities have become essential platforms for studying the strong coupling regime, where hybrid light-matter states known as exciton-polaritons form, leading to enhanced light matter interaction, modified material properties, and novel quantum phenomena. In this thesis, we explore the phenomenology of exciton-polaritons in strained TMD microcavities, 2D perovskites, fluorescent proteins and organic dyes encompassing thermalization, polariton lasing, and the observation of nonlinear effects.

Transition metal dichalcogenides (TMDs) have emerged as a remarkable class of two- …

Evaluation Of Symmetric Functions And Boolean Functions Over Stochastic Input, Naifeng Liu

Dissertations, Theses, and Capstone Projects

In our daily life, we often face situations where we need to make precise judgments based on initially unknown information, while gathering all the evidence to make informed conclusions can be very costly. In this dissertation, we explore the problem of optimizing the decision-making process under uncertainty, and we focus on problems that can be found in both theoretical computer science and discrete mathematics. The primary goal is to develop approximation algorithms with guaranteed worst-case performance. These algorithms aim to minimize the expected cost of acquiring information necessary for evaluating fundamental functions, such as Boolean and symmetric functions. Furthermore, we …

Reflections On The Digital Memory Of Trans-Atlantic Slavery, Vinh T. Pham

Dissertations, Theses, and Capstone Projects

Within the scope of digital humanities scholarship, this thesis interrogates ‘memory’ as a conceptual frame for remembering Black life, both past and present, in the face of missing historical data and in the afterlife of trans-Atlantic slavery. Such a concept—increasingly taken up as method in the humanities, along with related allusions to the ephemeral, spectral, or haunted—is sought to refuse historiographical and techno-scientific claims to empirical certainty or transparency, and instead affirm its gaps and absences as themselves productive sites for self-reflexive speculation on the complexities of lived experience. Applied to the digital study of trans-Atlantic chattel slavery, memory comes …

Automatic Analysis Of The Frequency, Vigor, And Complexity Of Spontaneous Locomotion Bouts Of Mice With Loss And Gain Of Function Of The G Protein-Coupled Receptor Smoothened In Cholinergic Neurons, Aleksandra Feshchenko

Dissertations, Theses, and Capstone Projects

Locomotion, a fundamental behavior, is classically assessed using simple metrics of velocity and total distance moved in an open field. This behavior however offers rich data about the organization and breadth of actions an animal can take while only facing limitations due to the bio-mechanical constraints of the organism. Importantly, these actions are not biased towards a particular task-solution space imposed by many behavioral paradigms. Here, to analyze motor complexity in freely ambulating mice, we developed a method for the automatic and unbiased identification of locomotor bouts which we call Bout Finder (BF). This analysis utilizes Open Feld data to …

Centrality Effects On Heavy-Flavor Quark Production And Invariant Yield In Phenix Proton–Gold Collisions At Center-Of-Mass Energy 200 Gev, And Assembly, Testing, Calibration, And Installation Of The Sphenix Hadronic Calorimeters, Daniel Richford

Dissertations, Theses, and Capstone Projects

Hadrons created in heavy-ion collisions interact with the open color-charge of the quark-gluon plasma through their constituent quarks. The medium imparts substantial modifications to heavy-flavor hadrons' momentum spectra. For collisions of small systems, the centrality of those collisions affects both the production of heavy-quarks and the medium modifications that the heavy-quarks experience. This analysis uses the PHENIX detector at the Relativistic Heavy Ion Collider, which collected data from proton--gold collisions in 2015, with a trigger to preference the collection of the five-percent most-central collisions. This analysis uses the distance-of-closest-approach of electron tracks to study semileptonic decays from charm and bottom …

Rotation Period Distributions And Light Curve Morphologies Of Low Mass Stars And Young Associations, Mark Popinchalk

Dissertations, Theses, and Capstone Projects

This dissertation is centered around the rotation periods of low-mass stars and association of young stars. Rotation periods are a link to the age of the star, as they lose angular momentum over time. To understand how this angular momentum evolves requires understanding the rotation period distributions of a range of stellar types and ages. Traditionally, M dwarf stars and young stars were challenging to describe due to their intrinsic faintness and dispersed sky positions respectively. I approached this subject from several directions.

Stereospecific Cross-Coupling Reactions With Enantioenriched Electrophiles, Iv Kraja

Dissertations, Theses, and Capstone Projects

We have developed a novel palladium-catalyzed stereospecific C(sp³)–C(sp³) Stille cross-coupling reaction between carbastannatrane nucleophiles and α-(trifluoromethyl) benzylic tosylates. This constitutes the first example of a stereospecific C(sp³)–C(sp³) cross-coupling reaction using an enantioenriched electrophile and an alkyltin nucleophile. This system has the potential to be extended to cross-coupling reactions using configurationally stable enantioenriched nucleophiles, thus enabling stereochemical control of two newly formed contiguous stereocenters. Generating enantioenriched α-(trifluoromethyl) benzylic compounds also has importance in pharmaceutical and agrochemical industries.

Through the development of this reaction, our findings show that the addition …

On The Second Case Of Fermat's Last Theorem Over Cyclotomic Fields, Owen Sweeney

Dissertations, Theses, and Capstone Projects

We obtain a new simpler sufficient condition for Kolyvagin's criteria, regarding the second case of Fermat's last theorem with prime exponent p over the p-th cyclotomic field, to hold. It covers cases when the existing simpler sufficient conditions do not hold and is important for the theoretical study of the criteria.

Recursive Functional Learning In Nonfluent Aphasia, Gerald C. Imaezue

Dissertations, Theses, and Capstone Projects

People with nonfluent aphasia (PWNA) require feedback from an external agent as well self-feedback to facilitate performance of language production tasks. The extent to which PWNA can use self-feedback alone to improve their task performance is unknown. In addition, it is argued that self-feedback may reinforce or minimize performance errors over time. To test whether either is the case, we introduce an original learning mechanism, recursive functional learning, which uses self-feedback loops to optimize recursively multiple subsystems (cognitive and linguistic subsystems) that PWNA engage during task performance. We used this mechanism to underpin a novel automated procedure we developed, recursive …

Drug Repurposing Using Gene Expression Data Mining, Yue Qiu

Dissertations, Theses, and Capstone Projects

The conventional drug discovery process that employs the "one disease, one target, one drug'' paradigm is expensive, time-consuming, and has a high rate of failure for multi-genic complex diseases. An alternative approach to drug discovery is to repurpose an existing drug that has been used to treat some medical conditions. Drug repurposing is considered a promising method due to its accelerated the process of drug discovery and lower overall cost and risk.

Drug-perturbed gene expression profiles are powerful phenotype readouts of biological systems, and they have been widely used in drug repurposing studies. However, the existing drug-perturbed gene expression datasets …

Towards Interpretable Machine Reading Comprehension With Mixed Effects Regression And Exploratory Prompt Analysis, Luca Del Signore

Dissertations, Theses, and Capstone Projects

We investigate the properties of natural language prompts that determine their difficulty in machine reading comprehension tasks. While much work has been done benchmarking language model performance at the task level, there is considerably less literature focused on how individual task items can contribute to interpretable evaluations of natural language understanding. Such work is essential to deepening our understanding of language models and ensuring their responsible use as a key tool in human machine communication. We perform an in depth mixed effects analysis on the behavior of three major generative language models, comparing their performance on a large reading comprehension …

The Effects Of Isolated Affordances On Preschool Counting Improvement When Using A Digital Coloring App, Katherine Papazian

Dissertations, Theses, and Capstone Projects

Counting is an important preschool math skill that is necessary for building a strong foundation in mathematics. Previous research has demonstrated that guided counting activities can improve counting ability in preschoolers and that drawing on paper while learning can deepen processing, but research has not included digital drawing as a potential means of deepening processing while children count. This study developed a novel touch-screen app, which used a guided coloring activity to encourage effective counting skills and serve as a home numeracy tool that could be employed by all parents, including those with math anxiety. To evaluate the benefits of …

On The Spectrum Of Quaquaversal Operators, Josiah Sugarman

Dissertations, Theses, and Capstone Projects

In 1998 Charles Radin and John Conway introduced the Quaquaversal Tiling. A three dimensional hierarchical tiling with the property that the orientations of its tiles approach a uniform distribution faster than what is possible for hierarchical tilings in two dimensions. The distribution of orientations is controlled by the spectrum of a certain Hecke operator, which we refer to as the Quaquaversal Operator. For example, by showing that the largest eigenvalue has multiplicity equal to one, Charles Radin and John Conway showed that the orientations of this tiling approach a uniform distribution. In 2008, Bourgain and Gamburd showed that this operator …

Reproducibly Defining Electrode Area Of Carbon Paper Electrodes Via Machine Cutting And High-Throughput Waxing, Rokas Gerulskis, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Carbon paper is one of the most common carbon electrode materials employed in electrochemical research due to its low cost, disposability, and controllable dimensions and scaling. Carbon paper is usually hand cut, and a variety of strategies are used to define electrode area. This procedure is tedious, imprecise, and inaccurate, yielding coefficients of variation in peak current output as high as 20%. Imprecision in hand-preparation translates directly to poor reproducibility in electrochemical data leading to challenges in directly comparing data across research groups and research fields. This work introduces an inexpensive and precise method to automatically cut and rapidly wax …

Complexity Of Verification In Self-Assembly With Prebuilt Assemblies, David Caballero, Timothy Gomez, Robert Schweller, Tim Wylie

Computer Science Faculty Publications

We analyze the complexity of two fundamental verification problems within a generalization of the two-handed tile self-assembly model (2HAM) where initial system assemblies are not restricted to be singleton tiles, but may be larger prebuilt assemblies. Within this model we consider the producibility problem, which asks if a given tile system builds, or produces, a given assembly, and the unique assembly verification (UAV) problem, which asks if a given system uniquely produces a given assembly. We show that producibility is NP-complete and UAV is coNPNP -complete even when the initial assembly size and temperature threshold are both bounded by a …

Decentralized Iot System Based On Blockchain And Homomorphic Technologies, Mohanad A. Mohammed, Hala B.

Iraqi Journal of Computers, Communications, Control and Systems Engineering

decentralization within IoT eliminates the need to use distributed networks within IoT to communicate only with servers that may face difficulties related to the internet, vulnerabilities, DDOS, or hijacks, merging blockchain with IoT converted the IoT system into a decentralized with many benefits and outcomes from this conversion. An encryption scheme homomorphic technique (HE) is a method that encrypts the cipher data without the need to decrypt it,paillier encryption method is used. This paper aims to propose a system that integrates Paillier cryptosystem homomorphic technology with IoT and lightweight blockchain technology to provide decentralization to the IoT environment and improve …

Distinct Architectures Of Feed Forward Neural Network For Implementing A Human Swing Leg System, Aws M. Abdullah, Ali Mohsin, Farah F. Alkhalid

Iraqi Journal of Computers, Communications, Control and Systems Engineering

The artificial intelligence techniques such as neural networks and fuzzy systems play an important role to disconnect flexion & expansion of the swing leg, the earth response force of the other foot has been redesigned. Underthat paper, we think the fuzzy controller plan Issue for yield following flawed genuine investigation of nonlinear systems. For examination, an essential fuzzy control plot has been bristly developed dependent on a current methodology delegate under the field.In this paper, the Feedforward Neural Network has been implemented with integer, fixed point and floating point data representations. Additionally, The Fuzzy Logic Controllers in both analog and …

A New Perspective For Mining Coco Dataset, Suha Dh. Athab, Abdulamir Abdullah, Kesra Nermend

Iraqi Journal of Computers, Communications, Control and Systems Engineering

Microsoft Common Objects in Context (COCO) is a huge image dataset that has over 300 k images belonging to more than ninety-one classes. COCO has valuable information in the field of detection, segmentation, classification, and tagging; but the COCO dataset suffers from being unorganized, and classes in COCO interfere with each other. Dealing with it gives very low and unsatisfying results whether when calculating accuracy or intersection over the union in classification and segmentation algorithms. A simple method is proposed to create a customized subset from the COCO dataset by determining the class or class numbers. The suggested method is …

Efficient Iris Image Recognition System Based On Machine Learning Approach, Hind Moutaz Al-Dabbas, Raghad Abdulaali, Akbas Ezaldeen Ali

Iraqi Journal of Computers, Communications, Control and Systems Engineering

Iris identification is a well‐ known technology used to detect striking biometric identification techniques for recognizing human beings based on physical behavior. The texture of the iris is essential and its anatomy varies from individual to individual. Humans have distinctive physical characteristics that never change. This has resulted in a considerable advancement in the field of iris identification, which inherits the random variation of the data and is often a dependable technological area. This research proposes three algorithms to examine the classifications in machine learning approaches using feature extraction for the iris image. The applied recognition system used many methods …

In-Depth Assessment Of Cryptographic Algorithms Namely Des, 3des, Aes, Rsa, And Blowfish, Samara Mohammed Radhi, Raheem A.

Iraqi Journal of Computers, Communications, Control and Systems Engineering

Securing information is difficult in the modern internet era, as terabytes of data are generated daily online and online transactions occur virtually every second. The current world's information security relies heavily on cryptography, which makes the internet a safer environment. Making information incoherent to an unauthorized person is done through the use of cryptography. Providing legitimate users with confidentiality as a result. There are a wide variety of cryptographic algorithms suitable for this purpose. An ideal cryptography method would allow the user to do their job without breaking the bank. Unfortunately, there is no magic formula that can address every …

Aku Research 2023, Office Of Research And Graduate Studies

Office of Research and Graduate Studies

- 40 years of research excellence

- Pioneering study to address adversity and brain development

- Multi-gene testing recommended for hereditary breast cancer

- IED builds support for teacher licensing in Pakistan

- Grading system developed by AKU-EB adopted in Pakistan

- One-quarter of health workers in Kenyan study show signs of depression

- The politics of the veil in interwar Turkey

- The state of East Africa’s news media: Confident under pressure

- Drug-resistant fungal infections raise alarm

- Researchers identify low-cost interventions for reducing malnutrition in Kenya

- Project tests feasibility of ultrasound scans in rural Kenya

- …

Experimental And Numerical Investigation On Thermal Properties Of Alkali-Activated Concrete At Elevated Temperatures, Min Yu, Hanjie Lin, Tan Wang, Feiyu Shi, Dawang Li, Yin Chi, L-Y Li

School of Engineering, Computing and Mathematics

his paper presents the experimental and numerical investigation on the thermal properties of steel fibre-reinforced alkali-activated concrete (AAC) made by using multiple precursors at elevated temperatures. The temperature-dependent thermal properties such as mass change, thermal conductivity, density, specific heat, and thermal expansion are reported. The effects of temperature heating AAC, coarse aggregate, and steel fibre on the thermal performance of AAC are evaluated quantitatively. Experimental results show that high temperature greatly affects the thermal properties of AAC. Coarse aggregate and steel fibre also have a considerable influence on the thermal properties. Based on the test results, a multi-phase mesoscale model …

Simulations Of Laser-Driven Strong-Field Qed With Ptarmigan: Resolving Wavelength-Scale Interference And Γ-Ray Polarization, T. G. Blackburn, B. King, S. Tang

School of Engineering, Computing and Mathematics

Accurate modeling is necessary to support precision experiments investigating strong-field QED phenomena. This modeling is particularly challenging in the transition between the perturbative and nonperturbative regimes, where the normalized laser amplitude a0 is comparable to unity and wavelength-scale interference is significant. Here, we describe how to simulate nonlinear Compton scattering, Breit–Wheeler pair creation, and trident pair creation in this regime, using the Monte Carlo particle-tracking code Ptarmigan. This code simulates collisions between high-intensity lasers and beams of electrons or γ rays, primarily in the framework of the locally monochromatic approximation. We benchmark our simulation results against full QED calculations for …

A Numerical Investigation Realizing The Flow Structure And Heat Transfer Performance Of The Potential Impinging Jets, Mohammed Sami Uddin Khan

Theses

The demand for improvement in the performance of gas turbines has led to the consideration of flows at increasingly high temperatures, but this introduces challenges in terms of maintaining their structural integrity and preventing overheating. To respond to these challenges, gas turbine manufacturers have turned to internal cooling, and jet impingement provides an effective solution for cooling the leading edge of the blades of gas turbines. In this study, the author numerically simulated the cooling performance of the leading edge of the blades of a gas turbine under constant heat flux by using five configurations of jet impingement: a steady …

Is Carbon Risk Priced In The Cross-Section Of Corporate Bond Returns?, Tinghua Duan, Frank Weikai Li, Quan Wen

Research Collection Lee Kong Chian School Of Business

This paper examines the pricing of a firm's carbon risk, measured by its carbon emissions intensity, in the cross-section of corporate bond returns. Contrary to the "carbon risk premium" hypothesis, we find bonds of firms with higher carbon emissions intensity earn significantly lower returns. This effect cannot be explained by a comprehensive list of bond characteristics and exposure to known risk factors. Investigating sources of the low carbon premium, we find the underperformance of bonds issued by carbon-intensive firms cannot be fully explained by divestment from institutional investors. Instead, our evidence is most consistent with investor underreaction to carbon risk, …