Engineering Commons^™

Spot: A Cubesat Mission For High-Resolution Monitorig Of Anthropogenic Sulfur Emissions, Carla Roesch, Colleen Golja, James Custer, Catherine Ember, Jerome Woodwark, Andrew Matheson, Joshua Vande Hey, Sonymol Vk, Steven Heer, Zixuan Gao, Tim Trent

Small Satellite Conference

Resolving individual industrial sources of SO₂ to constrain aerosol forcing — one of the largest remaining uncertainties in Earth's energy budget.

Effect Of Solid Particle Size And Density On Incipient Motion In A Turbulent Boundary Layer, Robert Bryan

Doctoral Dissertations and Master's Theses

Wind-blown sand and other instances of solid particles mobilized and suspended in gaseous turbulent boundary layers (TBLs) are seen in a wide variety of engineering contexts. An experimental framework was developed to study the incipient particle motion driven by external forcing within a turbulent boundary layer, which is provided by an airfoil section oscillating in the free-steam flow, resulting in a periodic disturbance in the near-wall region through production of synthetic large-scale structures at a fixed frequency. The incoming unsteady carrier-phase eddies were measured with a hot-film sensor upstream of a particle bed, and the particle motion was captured by …

A Polygon Approach For Satellite Coverage Computation Problems, Caleb I. Arbreton

Master's Theses

During celestial body observation mission planning, predicted sensor coverage is a key analysis tool used by designers to inform concept of operations. It enables trade studies by applying a metric to assess how well different sensor, satellite, and constellation configurations can observe a mission's region of interest. The effectiveness of the studied components is then paramount in determining whether they are justified in the system architecture. Coverage computation becomes more difficult as sensor types and regions of interest (RoIs) deviate from simple shapes, and as problem formulations seek higher-fidelity results. These simplifications include: conical camera sensors, RoIs represented as simple, …

Fuel Flexibility, Gas Turbine Combustion, Laser Diagnostics, Lean Blow-Out, Austin Thomas Shealy

Theses and Dissertations

To address increasing global energy consumption, energy industries seek to implement alternative fuels and increase energy generation efficiencies to meet energy demands. However, alternative and bioderived fuels present both chemical and physical properties significantly different from traditional hydrocarbon fuels typically used for gas turbine power generation. Consequently, they present unforeseen technical challenges. To address these challenges, ammonia has been suggested for use as a hydrogen carrier fuel in gas turbines. Ammonia presents many challenges by having a low overall reactivity as well as low energy density both by mass and volume. To address ammonia’s unique combustion characteristics, two strategies have …

Statistical Analysis Of Log Transformation Effectiveness In Air Traffic Movement Forecasting During Covid-19 In South Africa, John Lehlaka Masekoameng

Journal of Aviation Technology and Engineering

This study evaluates the effectiveness of log transformation in enhancing multiple regression models used to forecast air traffic movements (ATMs) in South Africa during the COVID-19 pandemic. Using 60 monthly observations from October 2016 to September 2021, the analysis incorporates variables such as revenue, lockdown levels, COVID-19 metrics, exchange rates, gross domestic product, and population. Two models are compared: one using raw ATMs and another with log-transformed ATMs as the dependent variable.

While the untransformed model shows stronger explanatory power (R² = 0.904, adjusted R² = 0.891) compared to the log-transformed model (R² = 0.772, adjusted R² = 0.741), the …

Plan To Fail By Failing To Plan: Deterring Prc Nuclear Force Expansion, Mark Tang, Grace Buettner

Space and Defense

This article argues that the United States must adapt its nuclear deterrence strategy to counter the People’s Republic of China’s (PRC) accelerating nuclear force expansion. As Beijing seeks to achieve nuclear parity with Washington—projecting up to 1,500 warheads by 2035—the authors contend that U.S. strategy must evolve from Cold War-era models to meet the Indo-Pacific’s unique strategic challenges. They propose the establishment of a Pacific Air Forces (PACAF) A-10 Strategic Deterrence and Nuclear Integration Division, modeled after its European counterpart, to enhance regional nuclear planning, integration, and allied assurance. The paper emphasizes the concept of escalation domination, arguing …

Mesopause-Region Gravity Wave Activity Due To Tropical Convection As Observed By Awe, Jeffrey M. Forbes, Xiaoli Zhang, Jiarong Zhang, Stephen D. Eckermann, Yucheng Zhao, Pierre-Dominique Pautet, Jun Ma, Ludger Scherliess, Michael J. Taylor

Space Dynamics Laboratory Publications

Mesopause-region (∼ 87 km) gravity waves (GWs) generated by tropical convection are investigated within the four longitude sectors encompassing Africa, the Indian Ocean, the Intertropical Convergence Zone, and South America during the Dec 2023– Feb 2024 Southern Hemisphere monsoon season. Variances (Q_v) in the OH Q-line emission measured by the Atmospheric Waves Experiment (AWE) capture GW activity, and precipitation rates (PR) from the Global Precipitation Measurement (GPM) Mission identify regions of convective activity. The zonal component of GWs comprising the Q_v between 10°S-10°N primarily propagate eastward. The Q_v distributions are latitudinally-shifted and more confined in …

Impact Assessment Of Multipoint Video Distribution Systems On Satellite Signal Reception, Ali Karaki, Hiba Abdallah, Mohammed Al-Husseini, Hamza Issa

BAU Journal - Science and Technology

This work analyzes the potential interference impact on Geostationary Earth Orbit (GEO) satellites stemming from Multipoint Video Distribution System (MVDS) transmissions, specifically examining side lobe radiation within Lebanon. Through simulations and analysis of antenna emission patterns, the study measures how varying MVDS power outputs affect the carrier-to-noise (C/N) ratio at the satellite receiver. Results reveal a significant impairment of signal quality, showing the C/N falling to -2.3 dB with an MVDS power level of 0 dBW under current system parameters. To counter this interference, a potential two-phase mitigation strategy is presented and its effectiveness considered. The study contributes to improving …

Awe Data Status, P.-Dominique Pautet, Anh Phan, Ludger Scherliess, Yucheng Zhao, Jiarong Zhang, Dallin Tucker, Connor Waite, Pedro Sevilla, Russell Kirkham, Harri Latvakoski, Jacob Adams, Keith Paskett

Space Dynamics Laboratory Publications

SDL Presentation on the AWE data status.

Turbulent Structures In Coupled Wind-Wave Flows, Cerrina Mouchref

Dissertations and Theses

The interactions between wind and waves in offshore environments are complex and have yet to be fully understood. Analyzing these interactions is motivated by an increased interest in climate modeling and the deployment of offshore construction, such as offshore wind farms. In this study, experiments are performed in a wind tunnel using particle image velocimetry (PIV) to analyze wind-wave interactions over various wave and wind speeds. The addition of the wave, a moving boundary, leads to the use of Reynolds triple decomposition in order to separate the turbulent and wave-phase coherent fluctuations. A curvilinear coordinate system was used to analyze …

Drone Medical Package Delivery For Improved Transportation And Better Patient Outcomes Final Implementation Report, Amro El-Adle, Madeline Alden, Yin-Hsuen Chen, Melissa Davidson

Information Technology & Decision Sciences Faculty Publications

The Drone Medical Package Delivery for Improved Transportation and Better Patient Outcomes planning and prototyping grant involves five partners, including Accomack-Northampton Planning District Commission (A-NPDC), Riverside Health System, Old Dominion University (ODU), Virginia Institute for Spaceflight & Autonomy (VISA), Virginia Innovation Partnership Corporation (VIPC), and DroneUp. The partners worked together to address access, safety, reliability and sustainability for medical and emergency response package delivery via drone, specifically, where the use of aerial drones could lead to better patient outcomes and improved safety and emergency response.

The goal of the project was to develop an operational prototype that woul evolve into …

Integrating Satellite-Based Precipitation Analysis: A Case Study In Norfolk, Virginia, Imiya M. Chathuranika, Dalya Ismael

Engineering Technology Faculty Publications

In many developing cities, the scarcity of adequate observed precipitation stations, due to constraints such as limited space, urban growth, and maintenance challenges, compromises data reliability. This study explores the use of satellite-based precipitation products (SbPPs) as a solution to supplement missing data over the long term, thereby enabling more accurate environmental analysis and decision-making. Specifically, the effectiveness of SbPPs in Norfolk, Virginia, is assessed by comparing them with observed precipitation data from Norfolk International Airport (NIA) using common bias adjustment methods. The study applies three different methods to correct biases caused by sensor limitations and calibration discrepancies and then …

U.S. 5g Technology Policy: Competition Or Boycott?, Wes Ferguson, Kyle Vargus

Space and Defense

Rather than corral allies and partners across the globe into boycotting Chinese 5G telecommunication systems, U.S. officials should embrace free-and-fair trade competition against China, even in products and services where China may enjoy a technological lead.

The race for technological supremacy has emerged as a defining characteristic of the newest era of great power competition. China and the United States compete to become the dominant world power. Each side is racing to create the latest and most elite technologies to catapult themselves into the lead and give them the edge over their adversary. The fifth generation of wireless technology, called …

Earth To Orbit: Three Models For Strengthening Space Deterrence, Anton Dahm

Space and Defense

Nuclear, cyber, and integrated deterrence models hold lessons for space deterrence strategy, including declared thresholds, resilient space architecture, and the embrace of international competition in technological innovation.

The United States depends heavily on space capabilities, significantly more than any other country. Not only does space enable navigation, communications, environmental monitoring, and other vital capabilities, but space has also been described as the most essential warfighting domain. However, the U.S. space architecture mirrors its early days: relying on important, expensive payloads on a limited number of satellites. While providing important capabilities to U.S. decision-makers, kinetic and non-kinetic weapons can easily target …

Strategic Space Cooperation: U.S. Space Command And The National Guard’S State Partnership Program, David Moore, Jesse Morehouse, Patrick Mitchell

Space and Defense

In 2022, the U.S. Space Command (USSPACECOM) and the National Guard's State Partnership Program (SPP) began pursuing security cooperation objectives while integrating the space domain into greater deterrence efforts. As the newest combatant command (CCMD) with space as its Area of Responsibility (AOR), USSPACECOM has global strategic partnership interests and recognizes the value of the enduring relationships inherent in SPP. This cooperation allows the National Guard to offer its strong relationships, space expertise, and industry knowledge to USSPACECOM. This provides a foundation for USSPACECOM's security cooperation efforts. This article discusses the SPP's role in supporting USSPACECOM's engagement strategy and the …

An Investigation Into The Use Of Amateur Astronomy Equipment For Optical Orbit Determination Using A Mobile Telescope Platform, Johan C. Govaars

Master's Theses

The process of optical orbit determination has long been in the domain of large organizations and stationary observatories with highly specialized scientific equipment. This thesis seeks to determine not only if satellites can be captured regularly using purely commercial-off-the-shelf (COTS) equipment, but also if initial orbit determinations can be made using that data. Moreover, the use of a mobile telescope platform allows users to circumvent the restrictions of fixed observatories such as low horizon viewing restrictions or existing light pollution.

A completely COTS setup was utilized that included an 8-inch Celestron NextStar 8SE telescope with an f/6.3 focal reducer and …

Impact Of Weather Systems On Uav Parameters Using Computational Fluid Dynamics, Saif Aljuhaishi, Yaseen K. Al-Timimi, Basim I. Wahab

Karbala International Journal of Modern Science

Since drones cannot fly in any kind of weather, they are not safe for time-sensitive activities. The study examines how the passage of weather systems in Iraq leads to the ban on drone flights, and how these weather conditions impact the aerodynamic forces of the drone. Hourly climate data for the study area were obtained from ECMWF ERA5 and CAMS in NetCDF format for four climate stations (Erbil, Baghdad, Rutbah, and Basrah). A ScanEagle drone was chosen for this study. The Python programming language was used to perform mathematical operations to calculate the ban on drone flights. ArcGIS 10.8 was …

Unleaded Fuel For General Aviation, Carolina Anderson, Laura Garcia

Sustainability Conference

The Clean Air Act, passed in the late 1970s, mandating the removal of lead from most fuels due its detrimental effects on public health, yet piston-driven aircraft continue to rely on leaded aviation gas (AvGas 100LL). This fuel remains the last lead-containing fuel regulated by the Department of Transportation (DOT). Lead, added as tetraethyl lead (TEL), enhances octane levels and prevents engine detonation, vital for high-compression aircraft engines. In response to the health effects, regulating bodies like the Environmental Protection Agency (EPA) have tightened lead standards and are assessing the risk posed by AvGas. Research links even low-level lead exposure …

Organisational Resilience : A Study Of The Resilience Of Maritime Stakeholders In Ghana, Priscilla Ami Dogbeda Dzokoto

World Maritime University Dissertations

No abstract provided.

Space And Defense Volume 15 No. 1 Spring 2024 (Whole Issue), Space And Defense

Space and Defense

No abstract provided.

Research Of The Influence Of Dust On Photovoltaic Modules, Anvarjon Mirolimov, Xalmurat Iliev

Technical science and innovation

The influence of dust concentrations on the current-voltage characteristics (voltampere characteristics) of photovoltaic modules (PVM) based on crystalline silicon in laboratory conditions. It was investigated how an uncleaned panel affects the output power. The tests were carried out in the city of Tashkent on the territory of the “National Research Institute of Renewable Energy Sources”. The objects were located co-plurally as specified in GOST R 60904-1 Photoelectric devices. Part 1. Measurement of current-voltage characteristics. Measurements of a cleaned photovoltaic module with a maximum power of 330 W and not a cleaned one of 236 W were obtained. Based on the …

A Nonlinear Least Squarees Approach To Orbit Determination In Near-Earth Orbits, Ryan M. Vorst

Theses and Dissertations

This work explores relevant scenarios to implement a Frequency on Arrival method using nonlinear least squares to determine a transmitting satellite’s orbit based only on measurements of the received radio frequency. Multiple relevant collection geometries, such as a target in prograde low earth orbit, in retrograde low earth orbit, in sun synchronous orbit, in near-perigee highly elliptical orbit, in near-apogee highly elliptical orbit, and in geosynchronous orbit, are simulated to collect theoretical received frequency data. Once data collection has been simulated, the theoretical apparent frequencies recorded are used in a nonlinear least squares method with differential correction to find a …

Stochastic Point Process Modeling For Engineering Applications, Samarth Motagi

Doctoral Dissertations and Master's Theses

Hawkes model or self-exciting point process model is a branching point process model. The model classifies the dataset of discrete events to background and offspring events. It has been used to study interconnected events in many fields, but relatively little work exists in applying these concepts to engineering problems. In our research, we use a self-exciting point process model for two engineering applications: (a) To identify secondary crashes from a given traffic data and (b) To quantify the agglomeration state and size of nanoparticles from computationally generated carbon nanotube microstructure using stochastic percolation model and experimentally generated titanium nanoparticle microstructures. …

Bureaucratic Politics Run Amok: The United States And Satellite Export Controls, Eligar Sadeh

Space and Defense

The case of export controls of United States (U.S.) commercial satellites is characterized by bureaucratic politics leading to policy outcomes that are not rational, i.e., the desired outcome of national security is not met and commerce in the satellite sector is harmed. The constraints to rational policy making are a result of competition, conflict, and protectionism, the “bureaucratic politics,” among the relevant actors including the U.S. President and Congress, Department of State (State), Department of Commerce (Commerce), and Department of Defense (DOD). It is bureaucratic politics that result in policies for licensing the export of commercial satellites that are far …

The History Of United States Weapons Export Control Policy, Taylor Dinerman

Space and Defense

All nations regulate Arms sales, but the United States (U.S.) has traditionally gone further than most. After World War I, a conspiracy theory made its way into popular culture that blamed the war, and specifically the U.S. intervention in 1917, on the so called “merchants of death.” Ever since, this has been a powerful and enduring theme in politics and culture throughout the world. Yet, nowhere have the effects of this theory been more enduring than in U.S. policy and law.

Asia, Space, And Strategy Workshop, Space And Defense

Space and Defense

In 2006, the Eisenhower Center for Space and Defense Studies held its first Asia, Space, and Strategy workshop. This effort brought together US, Canadian, and European experts and policy makers from the military, civilian government, universities, think-tanks, and the private sectors to discuss the implications of current and future Chinese space policy and investigate areas of possible Sino-U.S. cooperation and competition in space. Beginning in 2007, an invitation was extended to include Chinese academics in the discussions. Chinese participation has increased each year since then, with four attendees from China at the 2009 workshop in Vancouver, Canada.

Coalitions In Space: Where Networks Are Power, James Clay Moltz

Space and Defense

This study begins with the widely recognized problem of 21st century space vulnerabilities. To address this challenge, it proposes the new concept of an “allied space network” as a possible means of both reducing risks and enhancing space power. Such a concept would move beyond realist, Cold War “balancing” in space, and instead would require new forms of technical and political cooperation in the military sector among participating states. In thinking about future space security this study argues that trans-national networks and alliances offer considerable untapped potential, with possibly significant benefits particularly for the United States, which—unlike China and Russia— …

The New Space Order: Why Space Power Matters For Europe, Nicolas Peter

Space and Defense

More than fifty years since the dawn of the Space Age and twenty years since the end of the Cold War, space affairs and politics remain interlinked. Space activities are increasingly tied to national power for major world powers, and political objectives are still the driving force for most space activities. Yet in an ever more globalized and competitive multipolar world, status and power that arise from the employment and access to the most advanced technologies are now widely perceived as key to the powers and standings of states. The importance of space activities is increasing, transitioning in terms of …

International Space Negotiations, Emerging Space Powers, And U.S. Efforts To Protect The Military Use Of Space, Justin Anderson, Walt Conrad, Sarah Jacobs Gamberini

Space and Defense

In recent years strategists and diplomats from space faring nations have engaged in debates with their foreign counterparts (and in some cases, with each other) on a range of issues related to norms and laws – or the relative lack thereof – applicable to the military use of space. Questions have run the gamut from the very broad (should the slim volume of outer space law relevant to military platforms and operations be expanded?) to the very specific (what new technical tools are available for the verification regime of a notional future space arms control agreement?).

Editor's Note Volume 7 No. 1, Space And Defense

Space and Defense

No abstract provided.