Digital Commons Network^™

Exploring Small-Scale Propellers Performance At Low Advance Ratios, Ali Akber Mollick, Sara Catto, Forrest E. Ames, Clement Tang

Mechanical Engineering Student Publications

The performance of small-scale propellers was experimentally measured at low advance ratios and Reynolds numbers. The propeller diameters range from 14 to 19 inches, with all propellers having the same pitch value of 12. Using a thrust stand situated in a low-speed open-circuit wind tunnel, the propeller thrust, torque, and angular speed were measured at various freestream velocities. The results from this study offer insights on the performance of small propellers at low advance ratios and low Reynolds numbers. Propeller performance results at these conditions tend to be limited in the literatures. At the same pitch value of 12, the …

Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones

Aerospace Sciences Student Publications

Cyberattacks on space assets are often portrayed in vague terms of doubt and mystery. Several claims depict satellites being compromised or attacked, but little corroboration has been published or made publicly available. As the commercial space industry grows, increased concern with space cybersecurity will prompt commercial satellite decision-makers to analyze the often-undefined risk of cyberattacks against satellites. This article identifies and characterizes the nature of cybersecurity risks to space assets and postulates why space professionals might not prioritize cybersecurity. Additional information was captured from a decadal survey of space professionals conducted in 2012 and 2022. The results show a rise …

Is It Really A Neuromyth? A Meta-Analysis Of The Learning Styles Matching Hypothesis, Virginia Clinton-Lisell, Christine Litzinger

Education, Health & Behavior Studies Faculty Publications

Learning styles have been a contentious topic in education for years. The purpose of this study was to conduct a meta-analysis of the effects of matching instruction to modality learning styles compared to unmatched instruction on learning outcomes. A systematic search of the research findings yielded 21 eligible studies with 101 effect sizes and 1,712 participants for the meta-analysis. Based on robust variance estimation, there was an overall benefit of matching instruction to learning styles, g = 0.31, SE = 0.12, 95% CI = [0.05, 0.57], p = 0.02. However, only 26% of learning outcome measures indicated matched instruction benefits …

Dark Knights: Exploring Resilience And Hidden Workarounds In Commercial Aviation Through Mixed Methods, Riana Steen, James Norman, Johan Bergström, Gitte F. Damm

Aviation Faculty Publications

In this study, the duality of adaptive capacity in aviation safety is examined, where the need for resilience of frontline workers conflicts with the expectations and assumptions of upstream entities, leading to system brittleness. We explore three critical categories: responsibilization, the application of practical wisdom in navigating challenging situations, and the unrecognized sacrifices that accompany adaptation. A qualitative research design is used, using three focus groups consisting of pilots in a European airline, the airline’s safety department, and the respective civil aviation authority. The study's findings reveal i. significant organizational constraint and pressure on pilots, resulting in workarounds, personal playbooks, …

Supporting Elementary Engineering Instruction In Rural Contexts Through Online Professional Learning And Modest Supports, Rebekah J. Hammack, Julie Robinson, Tugba Boz, Min Jung Lee, Ryan G. Summers, Ashley Iveland, Martha Inouye, Meghan Macias, Maria Zaman, John Galisky, Natalie Johansen, Carolyn Ringstaff

Teaching, Leadership & Professional Practice Faculty Publications

No abstract provided.

Autonomous Image-Based Corrosion Detection In Steel Structures Using Deep Learning, Amrita Das, Sattar Dorafshan, Naima Kaabouch

Civil Engineering Faculty Publications

Steel structures are susceptible to corrosion due to their exposure to the environment. Currently used non-destructive techniques require inspector involvement. Inaccessibility of the defective part may lead to unnoticed corrosion, allowing the corrosion to propagate and cause catastrophic structural failure over time. Autonomous corrosion detection is essential for mitigating these problems. This study investigated the effect of the type of encoder–decoder neural network and the training strategy that works the best to automate the segmentation of corroded pixels in visual images. Models using pre-trained DesnseNet121 and EfficientNetB7 backbones yielded 96.78% and 98.5% average pixel-level accuracy, respectively. Deeper EffiecientNetB7 performed the …

Field Implementation And Surveillance Of Gas Injection Enhanced Oil Recovery In The Bakken, Jin Zhao, Lu Jin, Nicholas A. Azzolina, Xincheng Wan, Steven A. Smith, Nicholas W. Bosshart, James A. Sorensen

EERC Publications, Papers, & Presentations

A series of activities were performed in this study to explore real-time visualization, forecasting, and control methods for improved reservoir surveillance during EOR processes.

Investigating H2s Occurrence In Bakken Oil-Producing Wells Using Sulfur Isotopes In Gas, Water, And Rock Samples, Alexander V. Chakhmakhchev, Marc D. Kurz, T. Austin Mcrae, Xue Yu, Arash Abarghani, Darren D. Schmidt, Nicholas A. Azzolina, Bethany A. Kurz, James A. Sorensen

EERC Publications, Papers, & Presentations

This work investigated multiple mechanisms that can potentially lead to H₂S in the oil production stream of Bakken wells, including TSR, BSR, source rock generation, migration from deeper or shallower formations that contain H₂S, and geomechanical mechanisms related to reservoir stimulation work.

Malware Worm Attacks In Distributed Energy Resources (Ders)​, Shree Ram Abayankar Balaji, Tanzim Jim Hassan, Prakash Ranganathan

Computer Science Posters and Presentations

Malware is the short form of “Malicious Software” that is designed in a specific way to harm or exploit the host program with malicious intent. Often, the malware program replicates or appears as a legitimate executable program, which, upon the execution trigger, performs the programmed commands that cause systematic problems to the host machine. Malware attacks have become more sophisticated, which makes them more challenging to identify and analyze. If malware in critical infrastructures like Distributed Energy Resources (DER) are undetected, disruptions can occur in DERs. This poster discusses three types of malware worms (network, internet, and payload), historical malware …

A Statistical Model For The Surface Tension Of Microdroplet Surfactants And Multicomponent Mixtures, Douglas Mohr

Theses and Dissertations

The effects atmospheric aerosols have on climate are not fully understood due to the limited knowledge of the interaction between aerosols and clouds. This interaction, known as the indirect effect of aerosols, is an area of interest within the field of atmospheric science. The presence of surfactants in the atmosphere due to natural and anthropogenic sources is known to negatively affect cloud formation, and is a contributor to the indirect effect. Quantifying how surfactants affect atmospheric aerosols will improve the understanding of the indirect effect. This work explores a statistically mechanically derived surface tension model for surfactant aqueous solutions, which …

Modeling Ash Deposition During Oxy-Coal Combustion Of A High Alkali Earth Metal (Powder River Basin) Coal: Insights From Turbulence Modeling, Mohamed Zamzam

Theses and Dissertations

Coal production has waned in recent years despite its historical significance, driven by mounting concerns over climate change and the escalating adoption of renewable energy sources. With coal production in the U.S. expected to continue its decline and stricter environmental regulations looming due to increasing greenhouse gases and SO2 emissions, there is a critical need to identify an economically viable and environmentally friendly coal type. Embracing carbon capture-based technologies such as oxy-fuel combustion without compromising boiler performance is essential in this endeavor. Sub-bituminous coal varieties like Powder River Basin (PRB) coal boast lower sulfur and nitrogen content compared to bituminous …

Determination Of The Water To Cement Ratio Of Fresh Concrete Using Nir Hyperspectral Imagery, Eric Edwin Wiken

Theses and Dissertations

The water to cement ratio (w/c) is the primary mix design parameter that will control the strength of a concrete mix. Although a specific w/c is usually stated in concrete mix specifications, there is currently no practical test available that can quickly measure this critical property from fresh concrete. Near-infrared (NIR) Hyperspectral Imagery (HSI) can identify a material by measuring the response of the material to the incident NIR light reflecting off its surface in a range of wavelengths. This measured response can be used to differentiate between unique materials and identify variations of similar materials. This thesis studies the …

Contributing Factors To Low Airspeed On Climbout Events As A Precursor To Loss Of Control Within The National General Aviation Flight Information Database, Owen Dae Poborsky

Theses and Dissertations

The nature of aviation is not without inherent risk. Conducting flight training operations increases the overall risks due to inexperience of the student pilot and the challenges of the learning environment. Flight data seeks to reduce these risks; as seen in its success for commercial airlines. These successes are slowly coming to general aviation through programs like the National General Aviation Flight Information Database (NGAFID). This study seeks to determine if the type of takeoff performed by the flight crew led to a lower indicated airspeed (IAS) during a low airspeed on climbout event. Using 262 individual low airspeed on …

Evaluating Distributed Software Design Conformance Through Trace Comparison, Reid Barry Anderson

Theses and Dissertations

The design of a system and its implementation are two tasks often carried out by different individuals on a development team and can occur weeks or months apart. This creates a potential for divergence between real behavior and the designed model that the implementation is intended to match. Particularly as time passes and individuals that were present for the original conception of the design leave, a system can begin to lose coherence and drift apart from intended design principles. Even with a robust and high-quality design for a software system, more is needed to guarantee that the key details of …

Usda Wildlife Services Management Efforts At The Grand Forks Wastewater Treatment Plant, Dorothy Celeste Daulton

Theses and Dissertations

Wildlife collisions with aircraft (wildlife strikes) are a costly and dangerous issue. In recent decades, wildlife strikes within airport boundaries have decreased partly due to on-airfield wildlife strike mitigation efforts. Landscape attractants surrounding airfields within an 8 km radius have been found to influence the occurrence of wildlife strikes by increasing wildlife presence and abundance on or near airfields. The effectiveness of mitigation efforts can be increased by extending operations to include landscape features in an 8 km radius from airports. However, not much is known about the long-term effects of wildlife strike mitigation operations when conducted on neighboring properties, …

Investigating The Potential Of 3d Concrete Printing For Unreinforced Structures, Alireza Hasani

Theses and Dissertations

Additive manufacturing in construction has surged in recent years. This thesis explores the advancements of 3D Concrete Printing (3DCP) within additive construction. Through an exhaustive analysis of 137 built projects and various publications, the research synthesizes the states of research and practice of 3DCP technology. It offers insights into key factors influencing 3DCP structural performance, its potential advantages, and challenges. Additionally, the feasibility of employing 3DCP for constructing unreinforced structures, particularly unreinforced concrete pipes, is evaluated through series of experiments. The research aims to ensure compliance with standards and evaluate their suitability for real-world transportation applications by conducting structural, fresh, …

Advancing Bridge Hydraulic Assessment With Hec-Ras 2d And Bathymetry Modeling In Arcgis Pro Using Hycat Asv Data, Daniel Iancu

Theses and Dissertations

This research centers on verifying an accurate and reliable method in deriving river bathymetry near bridge sites, which leads to critical enhancement of bridge scour analysis. The structural integrity of bridges is paramount, and accurate scour analysis is a cornerstone in civil engineering and public safety. Existing methods, though reliable and very well cemented in practice, may be improved with more precise water velocity estimates, which is essential for thorough bridge scour evaluations. Bridge assessments utilize bathymetry measurements in significant spots and or map out the continuous surface at the bottom of the river. This study seeks to validate if …

Nir-Spectroscopy With Data-Driven Application For Inspection And Prediction Of Combined Fouling And Moisture Contamination In Railroad Ballast., Eberechi Orie Ichi

Theses and Dissertations

Ballast contamination is a significant and growing challenge that causes railway track deterioration, poor drainage functionality, and early failure of railroad components. Traditional, human, destructive, field sampling, and most nondestructive evaluation (NDE) inspection methods are ineffective. They are plagued by drawbacks, such as inefficiency, subjective inspection outcome, alteration of existing structures, undermining the stability of the railroad substructure, traffic disruptions, and safety concerns, or providing limited information about the condition of the ballast. Therefore, a reliable noncontact technique is needed to evaluate, characterize, monitor, and predict the presence of contamination in railroad ballast. The conventional contamination indices only account for …

Novel Methods To Increase Carbon Mineralization Rates, Charles Ekpewani Kwaku Kporxah

Theses and Dissertations

Humans have contributed to climate change through anthropogenic emissions of greenhouse gases, such as carbon dioxide (CO2), methane, chlorofluorocarbons, and nitrous oxide, into the atmosphere. CO2 emissions contribute approximately 79% to the warming of the Earth's surface. Various tactics have been developed to slow down global warming and prepare for climate change, including carbon mineralization. Carbon mineralization is a process that converts CO2 into solid mineral forms, such as carbonates, emulating the natural weathering process of alkaline silicate rocks. However, the rate of natural weathering is slow, occurring on geologic time scales. Therefore, the goal of this research is to …

Impacts Of Variations Of Temperature And Moisture Content In A Capping Feature On Thunderstorm Downdrafts, Andrew George Kramer

Theses and Dissertations

Thunderstorm downdrafts have been determined to be important factors in the near-surface dynamics of tornadogenesis. Tornadogenesis could be assisted by a downdraft and outflow that is cold enough to either tilt existing horizontal vortex lines or baroclinically generate vorticity at the surface. However, the downdraft should not be so cold that it would cut off the updraft of a thunderstorm with overly negatively buoyant air or by limiting the stretching of the updraft. The presence of a capping feature, or a layer of decreased lapse rate, can influence downdrafts by preventing transport of air from aloft, with associated properties, to …

Performance Assessment Of Wastewater Treatment Processes: Evaporation, Microplastic Settling, Biosolid Air Drying And Gasification, Fangtian Li

Theses and Dissertations

The main contaminants in wastewater can be classified as suspended solid, dissolved inorganic and organic molecules. The dissolved inorganics in wastewater are salinity such as sodium chloride and sodium sulfate. Evaporation is one possible method to separate dissolved salt from high salinity wastewater, but the proper application of energy-saving evaporation depends on many conditions. Microplastic is a part of total suspended solids and can be effectively removed through settling process, and the removal efficiency can be predicted by settling model. Biological treatment eliminates organic matters and biosolids are the inevitable by-products. Air drying is a sustainable approach for reducing water …

Lstm Application To Mobile Robotics For Stuck Detection, Wilson Lysford

Theses and Dissertations

This paper presents a solution for determining if a wheeled robot is stuck that is operating without high fidelity localization sensors or operating in a sensor denied environment. Expensive sensors are often left off of consumer grade robotics in order to make them more widely available to consumers. This leaves the robot without effective means of perception. Research has shown that LSTM neural networks can provide insight that would normally only be available to a robot fitted with expensive sensor packages such as RTK GPS or LIDAR systems. Specifically, IMU data paired with controller data and wheel odometry data. By …

A Uav Payload And A Smart Graphical User Interface For Real-Time Detection Of Defects In Steel Structures, Rajrup Mitra

Theses and Dissertations

As integral parts of different infrastructure constructions, steel structures must be monitored regularly for their durability, serviceability, and safety. However, environmental exposure of steel structures leads to defects over time that may compromise the structural integrity and lead to colossal repair costs if not detected early. Traditional manual inspection methods have limitations like accuracy constraints, inefficiency, and non-scalability. Hence, there is a need for cutting-edge technology-based solutions to streamline inspection processes. Thus, this thesis proposes a pioneering exploration into the development and integration of an Unmanned Aerial Vehicle (UAV) system and an intelligent Graphical User Interface (GUI) for real-time defect …

Additives Impact On Wet Strength And Size Development In Papermaking- Polyamide Epichlorohydrin (Pae), Alkenyl Succinic Anhydride (Asa) And Alkyl Ketene Dimer (Akd) Cases, Yao Parnell Ntifafa

Theses and Dissertations

Additives are ingredients used in papermaking to enhance fiber properties, introduce special properties to the paper and improve the efficiency of the paper making process. Wet strength agents, sizing agents, dry strength agents, fillers, retention aids, defoamers, dyes and pigments are common additives used in paper mills. Poor retention of wet strength additive such as PAAE (polyamide epichlorohydrin) and hydrophobicity loss due to ASA (alkenyl succinic anhydride) and AKD (alkyl ketene dimer) size reversion not only increase cost and reduce product quality in the mill but also increase customer complaints and rejections.In this study, a method was developed to quantify …

Using An Airship Design To Extend A Small Uncrewed Aircraft Flight Endurance, Joseph Reilly

Theses and Dissertations

One limitation of uncrewed aircraft is being unable to fly as long as needed for some operations, such as linear inspection. This research explores the flight endurance of an uncrewed aircraft using airship design. It investigates the benefits of using an airship design to increase the efficiency and extension of the flight of a small, uncrewed aerial system (sUAS). Thus, it is crucial to find ways to augment flight endurance. Two different airframes were built, and flight tested using a lifting gas to provide the lifting force and vectored thrust needed to move. Flight testing captured time in the air …

Vehicle Crashes In Minnesota: Spatial And Temporal Patterns And Contributing Factors To Crash Severity, Bastien Koralalage Pavithra Navodi Rodrigo

Theses and Dissertations

Vehicle crashes represent a critical global issue, resulting in numerous fatalities, injuries, and significant economic and societal impacts. In response, government officials worldwide are developing strategies and policies to enhance road safety and promote sustainable transportation systems, aiming for zero fatalities and injuries. Understanding the causes of crashes is essential for these efforts. This study focuses on identifying spatial and temporal patterns and contributing factors for the crash severity of vehicle crashes in Minnesota. Spatial distribution of crash hotspots is identified and visualized using spatial autocorrelation (global Moran I), hotspot analysis (Getis–Ord Gi*), and kernel density estimation in ArcGIS Pro. …

Assessment Of High-Performance Steels Through Additive Manufacturing And Ultrasonic Impact Peening, Md Touhidul Islam Rimon

Theses and Dissertations

This abstract focuses on the treatment of three distinct materials: 17-4 PH stainless steel, a nickelbased super alloy, and AISI 4140 stainless steel. The treatment process involves a combination of laser deposition and ultrasonic impact peening.

The study explores the effects of this treatment on the mechanical and microstructural properties of the mentioned materials. Laser deposition is utilized to enhance surface characteristics, such as hardness, wear resistance, and corrosion resistance. Nickel-based super alloys are known for their exceptional high-temperature strength and corrosion resistance, making them suitable for demanding applications in aerospace and power generation industries. AISI 4140 stainless steel is …

Water Quality Hotspot Analysis On Chlorophyll-A To Monitor Harmful Algal Blooms In Small And Medium Lakes Of North Dakota, Sae Young Lee

Theses and Dissertations

The water quality of recreational lakes degrades with Harmful Algal Blooms (HABs). HABs can block sunlight, lower oxygen levels, and may produce toxins. Industrial and domestic waste and fertilizer runoffs can enrich nutrients for HABs. Chlorophyll-a (Chl-a) is a significant indicator for tracking HABs and has been monitored increasingly using remote sensing techniques. In search for significant trends in hotspots of Chl-a concentrations in small and medium lakes of northeastern North Dakota, Chl-a water samples were collected in summer and fall of 2023. The study lakes include: Fordville Dam Recreation Area, Larimore Dam RecreationArea, Homme Dam Recreation Area, and South …

Public Instagram Accounts Of Saudi Women Public Figures In A Context Of Social Change, Gamra Motlaq Albogami

Theses and Dissertations

This research analyzed 100 Instagram posts of ten Saudi women's public figures using a qualitative methodology to explore how their cultural and gender roles and norms are portrayed and how these portrayals align with Saudi Arabia's Vision 2030 objectives. The findings indicate that these public figures integrate traditional cultural and gender norms with contemporary norms in their online presentations. Traditional attire and familial roles are commonly showcased, underscoring the profoundly ingrained importance of cultural values in alignment with the findings in existing literature. However, there was a noticeable shift towards contemporary portrayals of identity, particularly in professional life, reflecting the …

Applying Systems Engineering Principles To The Design Of Multi-Channel Functional Electrical Stimulator, Yasser Ayeva

Theses and Dissertations

Paralyzed patients due to spinal cord injuries or other injuries can produce functional movements with the help of functional electrical stimulation (FES). Electrical discharges are applied to the patient's muscles to help with specific movements like walking, standing, and holding and grasping objects (Cleveland Clinic,2023). FES is not a novel technology, in fact, the term FES was not used until 1967 when Moe and Post created it. (Moe & Post, 1962). This technology has been around, and a wide range of devices utilizing it are currently on the market to support patients' treatment and rehabilitation all over the world. As …