Digital Commons Network^™

Automation And Visualization Of Program Correctness For Automatically Generating Code, Jason Michael Hicks

Theses and Dissertations

Program synthesis systems can be highly advantageous in that users can automatically generate code to fit a wide variety of applications from high-level specifications without needing any low-level programming skills or knowledge of which type of data structures and algorithms should be used. NASA has developed and uses two of these systems, AUTOFILTER and AUTOBAYES. Though much is gained in terms of time and cost efficiency in the use of these systems, they suffer from an issue that is inherent in all code generator systems, the verifiability of the correctness of the generated code against the input specifications. Many times, …

Molecular Simulation Study Of Enhanced Oil Recovery Methods In Tight Formation, Chuncheng Li

Theses and Dissertations

The Middle Bakken Formation of the Williston Basin is a typical tight formation with the predicted primary oil recovery of less than 10%, which results in large amounts of oil remaining in the reservoir. Therefore, an effective enhanced oil recovery (EOR) method for recovering the residual oil is crucially important. To obtain the microscopic EOR mechanisms, molecular simulation methods including Monte Carlo (MC) simulations and molecular dynamics (MD) simulations were applied to study the various EOR methods, such as CO2 injection, hydrocarbon gas injection, and nanofluid flooding. A series of molecular models, including bulk systems, interfacial systems, and nanoconfined systems, …

Uncertainty Quantification And Economic Dispatch Models For The Power Grid, Arun Sukumaran Nair

Theses and Dissertations

The modern power grid is constrained by several challenges, such as increased penetration of Distributed Energy Resources (DER), rising demand for Electric Vehicle (EV) integration, and the need to schedule resources in real-time accurately. To address the above challenges, this dissertation offers solutions through data-driven forecasting models, topology-aware economic dispatch models, and efficient optional power flow calculations for large scale grids. Particularly, in chapter 2, a novel microgrid decomposition scheme is proposed to divide the large scale power grids into smaller microgrids. Here, a two-stage Nearest-Generator Girvan-Newman (NGGN) algorithm, a graphicalclustering-based approach, followed by a distributed economic dispatch model, is …

Aqueous Imbibition With Enhanced Contact Area Approaches To Extract Oil From The Bakken Formation, Jin Zhang

Theses and Dissertations

The techniques of horizontal wells and hydraulic fracturing enable oil production from low-permeable shale, sandstone and carbonate rock formations. However, the extremely low permeability and porosity properties lead a sharp declination of oil production and a low oil recovery factor (typically, 5-15% of original oil in place) as reservoir pressures dropping. Surfactant EOR (enhanced oil recovery) has been considered as one of the best options for geological challenging formations. In our previous studies, we developed a method using surfactant formulation spontaneous imbibition to stimulate the oil recovery from tight formations through wettability alteration and the interfacial tension (IFT) reduction. However, …

Geothermal Energy From Repurposed Oil And Gas Wells In Western North Dakota, Sidike Abudureyimu

Theses and Dissertations

Repurposing directional drilled Bakken oil wells to utilize ORC technology for electrical power generation is uneconomical for co-produced fluid in current active oil and gas fields in the Williston Basin. Geothermal power generation requires three crucial factors: heat source, sufficient and sustainable flow rate, and efficient binary technology. This feasibility study focuses on evaluating geothermal co-production fluid for current Sanish, Parshall, and Banks Bakken multi-wells pads. The wells lie within a 2.5-mile (4 km) radius within each field and extend to depths of 9,900 to 11,000 ft. (3 - 3.5 km). Within a 2.5-mile radius area, there are several multi-well …

A Computational Assessment Of Flame Characteristics Of Premixed And Non-Premixed Ethylene-Oxygen Combustion With A Reduced Chemical Reaction Mechanism, Sam Cowart

Theses and Dissertations

Conventional fuel-air combustion processes are widely used in the chemical processing industry, but often suffer from high NOx emissions and difficulties with CO2 capture from flue gases. Oxy-fuel combustion offers advantages over fuel-air combustion that addresses these shortcomings. One possible fuel for oxy-fuel combustion is ethylene, a gas that is produced in large quantities industrially. The numerical literature regarding ethylene-oxygen combustion is limited in scope.

This study focuses on obtaining flame characteristics of premixed and non-premixed ethylene-oxygen combustion using numerical methods and computational fluid dynamics (CFD) approaches. This study offers several contributions to the current research: (1) the use of …

Twice-Exceptional College Students Narratives: When Giftedness And Mental Health Intersect, Emily Dubord Hill

Theses and Dissertations

Gifted college students often arrive at universities with high GPAs and/or ACT/SAT scores. Their achievements in extracurricular activities such as in the arts, athletics, service, and leadership are well beyond the average student. To admissions representatives and faculty, these students look well-adjusted and successful on paper. However, many of these gifted college students come with unique challenges that go misunderstood, ignored, and underserved during their years in higher education—specifically involving their mental health.

There are copious amounts of literature on gifted K-12 students and their mental health behaviors but very limited research done on the gifted college student population. Although …

Pilot Perception Of Automation Use: A Generational Assessment, Ryan Leadens

Theses and Dissertations

As flight deck technology has become more advanced, the pilot–machine interaction has become a larger point of emphasis in pilot training programs. Increasing demand for air travel in future decades will create greater need for highly accurate and reliable navigation systems. These systems reduce a pilots’ exposure to “stick and rudder” skills while increasing the knowledge and situational awareness required to operate safely.

It is imperative that pilots are properly trained on these systems prior to conducting line operations. In order to create an efficient and effective training program, it is important to understand how pilots perceive their role on …

Time-Dependent Plastic Deformation Of Mg Nanocomposites: Ambient And Elevated Temperature Assessments, Jiselle Thornby

Theses and Dissertations

Magnesium (Mg) nanocomposites are promising materials for many lightweight engineering applications. By adding a nanoparticle phase, like carbon nanotubes (CNTs) to a Mg matrix phase, new strengthening mechanisms are activated and enable the resulting nanocomposite to have better mechanical properties, e.g., strength and ductility, than unreinforced Mg. The viability of using Mg-CNT nanocomposites in lieu of heavier structural metals in industrial dimensions, especially those at high temperatures, cannot be assessed until these materials have been comprehensively characterized.

In the present project, the nanoindentation technique was used to assess the creep and hardness response of pure Mg and Mg reinforced with …

Gemütlichkeit Verboten: The Influence Of World War I Anti-German Sentiments On Prohibition, Susanne Schenk Watts

Theses and Dissertations

The proximity and simultaneity of World War I and Prohibition pose questions of a shared and connected relationship. The current historiography falls short to connect these two seminal events and their impact on German-American communities. This study expands the existing literature by analyzing the reactions of two German-American communities (New Ulm, Minnesota, and St. Louis, Missouri) to Prohibition against the backdrop of anti-German sentiments of World War I. Using a diverse range of sources (anti-German war propaganda material, Anti-Saloon League posters, material from the United States Brewers’ Association and US Senate investigation, as well as German and English-language newspapers from …

Statistical Analysis And Machine Learning For Coal Classification For Rare Earth Elements + Y (Rey), Zachary Bartley Young

Theses and Dissertations

Due to their exceptional properties, rare earth elements (REEs) are critical to technological innovation in renewable energy production, electronics, health care, and national defense. They make up key components for many applications in the above areas. Many countries rely upon rare earth element imports. The high demand for rare earth elements has led to the development of alternative methods for exploration and capture. Coal has been labeled a viable potential source of rare earth elements and yttrium (REY). Statistical evaluation of REY concentrations and the properties of various coal samples is critical for successful characterization.

The USGS COALQUAL database Version …

First-Principles Studies Of Two-Dimensional Transition Metal Carbides For Spintronics And Energy Applications, Edirisuriya Mudalige Dilanga Siriwardane

Theses and Dissertations

Next-generation spintronic nanoscale devices require two-dimensional (2D) materials with robust ferromagnetism. Among 2D materials, MXenes are favorable for spintronic applications due to their high electron conductivity, mobility, and chemical diversity. Since 2D materials have greater elastic strain limits than their bulk counterparts, their properties can be tuned effectively using strain engineering. In this dissertation, we discuss density functional theory (DFT) based first-principles studies on ferromagnetic MXenes for spintronics applications. In Chapter III, we investigated modifications in the structural, electronic, and magnetic properties produced by strain on 2D Hf2MnC2O2 and Hf2VC2O2 ferromagnetic semiconductors. The calculations in Chapter III reveal that the …

The Influence Of High Intensity Turbulence And Secondary Flows On Slot Film Cooling Over An Aft Loaded Vane, Loren Soma

Theses and Dissertations

The purpose of this study is to experimentally investigate the effects of high turbulence and secondary flows on slot film cooling over an aft loaded vane (turbine blade) with a large leading edge. Turbine nozzle component cooling methods are challenged by very high combustor discharge temperatures, turbulence effects, and high acceleration requiring cooling methods to provide reliable and acceptable component life. Throughout the development of gas turbines, film cooling has become one of the most prevalent techniques to protect high pressure turbine airfoils and endwalls. Film cooling works by supplying a film of cooler than the freestream gas onto the …

Effects Of Choice Orientation And Consensual Non-Monogamy On Relationship Quality, Meara Thombre

Theses and Dissertations

Consensual non-monogamy (CNM) is a style of sexual or romantic relationship that consensually includes more than two people. Despite a notable prevalence of CNM relationships in the United States, there is relatively little research on this population. While previous research generally finds similar levels of relationship quality to that of monogamist relationships, those in CNM relationships experience notable stigma and are an understudied population. The current study used the Maximization Paradox (Dar-Nimrod, Rawn, Lehman, & Schwartz, 2009) to investigate whether individual differences in choice orientation might impact relationship quality differently in CNM and monogamist relationships. Specifically, it investigated whether maximizers, …

Treatment Of Bakken Produced Water Using Supercritical Water Desalination, Joshua Oloruntimilehin Oluwayomi

Theses and Dissertations

Recent advances in horizontal drilling and hydraulic fracturing have significantly increased freshwater usage. Oil and gas wells in the United States tend to generate over 23 billion barrels of produced water per year of which about 32 million b/day are high total dissolved solids (TDS > 200,000 mg/L) while the world is gradually running short of fresh water. Environmental concerns associated with water usage and concentrated wastewater disposal have led to the growing consideration to treat and recycle brine for reusable purposes like crop irrigation, livestock watering and hydraulic fracturing.

In this study, an emerging and promising technology called supercritical water …

Aerocom: Winter 2020, John D. Odegard School Of Aerospace Sciences

Aerocom: John D. Odegard School of Aerospace Sciences Alumni Magazine

No abstract provided.

Winter Commencement: December 19-20, 2019, University Of North Dakota

UND Commencement Programs

UND Winter Commencement program from December 19-20, 2019.

Volume 57, Number 19: December 18, 2019, University Of North Dakota

University Letter Archive

No abstract provided.

Volume 57, Number 18: December 11, 2019, University Of North Dakota

University Letter Archive

No abstract provided.

December 5, 2019, University Of North Dakota

University Senate Meeting Minutes

Minutes from the December 5, 2019, meeting of the University Senate. 3 pages

Und Today: December 2019, University Of North Dakota

UND Today Archive

No abstract provided.

Thin-Walled Steel Tubular Circular Columns With Uniform And Graded Thickness Under Bidirectional Cyclic Loading, Qusay Al-Kaseasbeh, Iraj H.P. Mamaghani

Civil Engineering Faculty Publications

Thin-walled steel tubular circular columns are becoming an increasingly attractive choice as cantilever bridge piers due to their architectural, structural and constructional advantages. This paper aims to evaluate the strength and ductility of thin-walled steel tubular circular columns with uniform thickness (BC) and graded thickness (BGC) under bidirectional cyclic lateral loading in the presence of constant axial force. The analysis is carried out using a finite-element model (FEM) which is substantiated based on the experimental results in the literature. Then, the proposed BGC column with size and volume of material equivalent to the BC column is investigated. As a part …

December 5, 2019: Agenda, University Of North Dakota

University Senate Meeting Minutes

Agenda for the December 5, 2019, meeting of the University Senate. 110 pages

November 26, 2019, The Dakota Student

The Dakota Student

No abstract provided.

Volume 57, Number 15: November 20, 2019, University Of North Dakota

University Letter Archive

No abstract provided.

Practitioner's Guide To Small Unmanned Aerial Systems For Bridge Inspection, Sattar Dorafshan, Robert J. Thomas, Calvin Coopmans, Marc Maguire

Civil Engineering Faculty Publications

Small unmanned aerial system(s) (sUAS) are rapidly emerging as a practical means of performing bridge inspections. Under the right condition, sUAS assisted inspections can be safer, faster, and less costly than manned inspections. Many Departments of Transportation in the United States are in the early stages of adopting this emerging technology. However, definitive guidelines for the selection of equipment for various types of bridge inspections or for the possible challenges during sUAS assisted inspections are absent. Given the large investments of time and capital associated with deploying a sUAS assisted bridge inspection program, a synthesis of authors experiences will be …

Volume 57, Number 14: November 13, 2019, University Of North Dakota

University Letter Archive

No abstract provided.

Structure-Property-Function Connections Underlying Performance Of Polybenzoxazole Membranes Derived From Bisapaf Polyimides, Maram A. Q. Al-Sayaghi, Jeremy Lewis, Chris Buelke, Ali Alshami

Chemical Engineering Faculty Publications

Highlights

• Stable rigid monomers result in polyimides with higher Mw, Tg, TR, and the more superior separation performance.
• Thermal rearrangement improved ideal gas separation by 1.5 to 2.0 orders of magnitude.
• Thermal rearrangement resulted in an enhanced thermal, mechanical and chemical properties of the produced membranes.

Polymeric membranes remain and will most likely continue to be the most practical cost-effect chemical constructs for gas separation processes, provided that novel polymers are developed to overcome current and persisting limitations facing exiting membranes. Here, we report a methodical and systematic study of the structure-property-function relations of standard polyimide membranes and their implications …

Volume 57, Number 13: November 06, 2019, University Of North Dakota

University Letter Archive

No abstract provided.

November 5, 2019, The Dakota Student

The Dakota Student

No abstract provided.