Digital Commons Network^™

A Proposed Development Process For A Hardware-In-The-Loop Testing System For Cubesat Components, Vahini N. Patel, Victoria Coverstone

Small Satellite Conference

Hardware-in-the-loop testing systems, commonly known as FlatSats, are testbed systems in which spacecraft subsystems, such as the onboard computer (OBC), power system, attitude determination and control system (ADCS), and communications, are laid flat and interconnected as they would be in an actual spacecraft. This arrangement gives easy access to each subsystem, enabling hardware and software testing and troubleshooting without risking fully assembled flight hardware.

FlatSats are widely used throughout the aerospace industry, from government agencies like ESA and NASA to private companies and university research labs, due to their versatility in enabling parallel development. This accelerates timelines and reduces …

Power Simulation Framework For Korucusat-2 Using Freeflyer, Sahil Singh, Annabel Rong, Mukund Karthikeyan

Small Satellite Conference

A FreeFlyer-based power simulation was developed for KORUCUSAT-2, a low Earth orbit CubeSat designed to monitor silicon-anode battery behavior in space. The spacecraft model uses body-mounted solar panels with five modules on each of the +X, -X, +Y, and -Y faces. The simulation integrates orbital propagation, Earth shadowing, Sun-incidence angle, ground-station visibility, mode-dependent subsystem loads, and battery-state propagation to estimate electrical margin. Battery watt-hours and normalized state of charge are updated at each 30 s step so that critical, low-power, operations, and transmission modes can be evaluated against stored-energy limits. The framework provides a traceable prelaunch test bench for power-system …

Multi-Satellite Optical Link Scheduling With Direct Nonlinear Attitude Planning, Leif Nelson, Yung-Jai Pomeroy, Daniel J. Garcia

Small Satellite Conference

The Problem:

Low Earth Orbit (LEO) constellations increasingly rely on Optical Inter-Satellite Links (OISL) to route data across dynamic satellite networks. As satellites move through their orbits, communications continuously change due to line-of-sight constraints, link quality variations, and spacecraft pointing limitations. Traditional routing approaches often consider network optimization separately from spacecraft attitude control, creating a disconnect between planned routes and physically achievable communication links. This work addresses the challenge of simultaneously generating communication routes while validating that satellites can physically point toward their assigned target. The result is an end-to-end framework that integrates network planning, optical link feasibility, and spacecraft …

Spatial Reconstructability Analysis: Information-Theoretic Modeling Of Categorical Raster Data, David Percy

Dissertations and Theses

This research focuses on the application of Reconstructability Analysis (RA), an information-theoretic machine learning (ML) methodology, to categorical spatial data in Geographic Information Systems (GIS). RA was developed in the systems community with applications including classification, prediction, pattern recognition, and decision analysis. RA is implemented in OCCAM (Organizational Complexity Computation and Modeling), a software suite developed at Portland State University that analyzes discrete data in tabular form, with observations in rows and variables in columns. While RA has been successfully applied to a variety of domains, no systematic application to georeferenced raster data arranged in regular grids has been previously …

A Comparative Analysis Of Radio Frequency And Optical Inter-Satellite Link Communications For Leo Mega-Constellations, Alexa Houck, Suryansh Aryan, Kevin Schroeder, Samantha Kenyon

Small Satellite Conference

SpaceNet design  

Software-based testbed for simulating large satellite networks, specifically LEO-based constellations to analyze network behavior, connectivity, routing, and overall communication.  

• Phase one focuses on connectivity and routing: Given the topology and link availability over time, how does my network behave? 
• Phase two focuses on network emulation: Given the topology and link availability over time, how does my network behave? 

Promoting Assured Formation Flight Autonomy Onboard Resource Constrained Systems, Ryan Johnson, Maggie Michelsen, Jackson Gardner, Mario Harper, Charles Swenson, Jackson Kulik, Shawn Jones

Small Satellite Conference

Autonomously determining fuel-optimal, formation-keeping trajectories for small spacecraft operating in formation flight is often limited by available processing power. Because SmallSat missions are constrained by size, weight, and power (SWaP), field-programmable gate arrays (FPGAs) are an attractive option for onboard computing. Traditional formation-keeping relies on convex optimization to solve for fuel-optimal burns and burn times; however, implementing these solvers on FPGAs is challenging due to limited board resources.

To address the need for fast, reliable trajectory planning onboard space vehicles, we investigate leveraging machine learning to reduce computational cost for real-time, onboard execution. We propose using a deep neural network …

Evaluation Of Graphene Cathode And Aluminum Ion Ev Battery Performance: A State-Of-The-Art Analysis For Future, Abu Shadate Faisal Mahamude, Kaniz Farhana

The Nexus of Sustainability and Energy Technology Journal

Lithium-ion batteries may eventually be replaced with rechargeable aluminum-ion batteries (AIBs) due to their high energy density, increased safety, and plentiful supply of raw materials. The development of appropriate cathode materials for AIBs is a major priority these days. As a result of their better quality, graphene-based cathodes have a great chance of success. Graphene is a relatively new and promising material with a unique set of chemical and physical characteristics. Graphene's high electron conductivity and large specific surface area make it seem like one of the best electron-conducting additions, but there are several other ways to increase the cathode …

Ensuring Safety In Battery Management Systems: A Control Barrier Function Approach, Magdalena Kossek

Electronic Theses and Dissertations

Safe and efficient operation of batteries is paramount to extending their lifespan and ensuring reliability in battery management systems. This work presents a new approach for maximizing safety and performance of lithium-ion batteries in a variety of applications with a view towards efficiency in computation. The aim is to maximize a battery’s output (its power, speed of charging, and overall efficiency) while preserving its longevity and ensuring operational safety. This challenge is tackled by developing a novel control algorithm for advanced lithium-ion battery management leveraging control barrier functions (CBFs) to ensure safe and efficient operation during fast charging and discharging. …

Compact 1 Ghz Electron Paramagnetic Resonance Spectrometers For Preclinical Imaging Studies, Tanden A. Hovey

Electronic Theses and Dissertations

Magnetic resonance is one of the most generally useful scientific techniques. New horizons of understanding are revealed as technological advances make possible explorations of nuclear spins and electron spins at higher and lower magnetic fields and electromagnetic frequencies. While the greatest current effort is on ever higher magnetic fields and microwave frequencies, both in nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR), the Eaton lab focusses on developing high signal-to-noise performance EPR at low microwave frequencies. EPR provides information about O2, pH, viscosity, glutathione concentrations, and reactive oxygen species in living organisms that MRI cannot. To yield clinically or …

Field-Like- And Self-Spin-Orbit Torques In Magnetic Multilayer Films, Kyle Jeffrey Peterson

Electronic Theses and Dissertations

Spin-orbit torques (SOTs) have been realized as an energy efficient mechanism to manipulate and drive magnetization dynamics in magnetic multilayer films. Their damping-like and field-like components provide distinct pathways for controlling the magnetization, enabling switching, sustaining magneto-oscillations, and driving domain-wall motion with potential applications in nonvolatile memory, spin-based logic, and microwave signal generation. However, the accurate quantification and interpretation of these torques remains complicated by experimental sensitivity, the co-symmetry of the Oersted field and the effective field due to the field-like torque, and assumptions regarding the material layers from which the torques originate. The body of work set forth in …

A Longitudinal Study Of Achilles Tendon Adaptation In Ncaa Division I Female Gymnasts: Associations With Menstrual Status, Birth Control Use, Pain, Limb Dominance, And Training Exposure, Mattie Jane Hyde

Electronic Theses and Dissertations

This longitudinal study evaluated Achilles tendon (AT) thickness in 22 NCAA Division I (DI) female gymnasts across three consecutive seasons in relation to menstruation, birth control use, pain, limb dominance, training week, and year of collegiate competition. Weekly ultrasound and athlete survey data were analyzed using mixed-effects models for absolute AT thickness and change in thickness from baseline measurements. Associations were primarily characterized by interactions rather than uniform effects of individual predictors. A Pain × Limb Dominance × Week × Year interaction was associated with both thickness outcomes across season-specific and combined analyses, with relationship directions varying by limb, season …

An Investigation Of Pelvic Kinematics And Implications For Total Hip Arthroplasty, Kathryn Holland Colone

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most commonly performed orthopaedic procedures, with approximately 500,000 surgeries performed annually in the United States alone. Although THA is widely regarded as highly successful, postoperative complications persist, highlighting the multifactorial nature of THA outcomes. Previous studies have demonstrated the importance of implant positioning and soft tissue mechanics, yet challenges remain in optimizing surgical decisions on a patient-specific basis. Recent advances in surgical planning tools have shifted the focus of preoperative planning toward optimizing patient-specific outcomes, highlighting the need to better understand how patient anatomy, surgical technique, and joint mechanics interact to influence …

Techno-Economic Analysis Of Implementing Carbon Capture And Storage (Ccs) At The Punagaya 2×100 Mw Coal Power Plant, Ricky Andreas Kristianto Siringoringo, Rahma Muthia, Widodo Wahyu Purwanto

Journal of Materials Exploration and Findings

The increase in greenhouse gases due to the combustion of fossil fuels is one of the major drivers of global warming and consequently drives the development of low-carbon technologies such as Carbon Capture and Storage (CCS). The aim of this study is to evaluate the technical and economical feasibility of the implementation of CCS technology in the Punagaya Subcritical Coal-Fired Power Plant (CFPP) 2×100 MW as a part of the energy transition strategy towards Net Zero Emissions (NZE) 2060. The simulation was carried out using Aspen HYSYS software, including coal combustion, CO₂ capture through MDEA-PZ solvent, dehydration, transportation, and storage …

Exploring Red Palm Oil As A Sustainable Plasticizer For Carbon Black-Filled Ssbr/Br Tire Tread Compounds: A Comparative Evaluation Of Commercial Alternatives, Norma Arisanti Kinasih, Mohamad Irfan Fathurrohman, Santi Puspitasari, Dewi Kusuma Arti, Abdulhakim Masa

Journal of Materials Exploration and Findings

This study investigates the application of red palm oil (RPO) as an alternative vegetable oil resource to substitute petroleum-based plasticizers, which have environmental and health concerns, in carbon black (CB)-filled SSBR/BR tire tread compounds. The plasticizing effects of RPO were thoroughly evaluated by comparing them with a commercial bio-based plasticizer, Epoxidized Soybean Oil (ESBO), and two safer petroleum-based oils, Naphthenic Oil (NYNAS) and Treated Distillate Aromatic Extract (TDAE). The initial investigation shows that fatty acid composition is imposing regarding the plasticizing effect. The higher unsaturated fatty acid content in RPO than in ESBO improved tensile strength and degraded rolling resistance …

Analysis Of Tower Stringset Replacement From 33 Kv To 66 Kv Considering Sagging Clearance, Muhammad Lazuardi Azzura, Anne Zulfia Syahrial, Julius Purnama Eka Kartika

Journal of Materials Exploration and Findings

Efforts to increase the capacity of transmission networks are often undertaken by uprating the operating voltage of existing lines rather than building entirely new infrastructure. Such uprating typically involves the replacement of tower insulator stringsets to withstand higher voltages, while also ensuring that mechanical performance remains adequate. This paper presents an analysis of uprating the Parakan–Sunyaragi transmission line from 33 kV to 66 kV, with particular emphasis on conductor sagging and the resulting clearance from the ground. The methodology employed includes calculations based on catenary equations, analysis of conductor tensile forces, and a comparative evaluation of two widely used insulator …

Metallurgical Investigation Of A Modified Eye Bolt Failure Caused By Improper Weld Extension, Specification Deviation, And Crevice Corrosion, Dimas Muhammad Fawwaz, Reza Miftahul Ulum, Johny Wahyuadi Soedarsono, Yudha Pratesa

Journal of Materials Exploration and Findings

A modified eye bolt from the David Arm Manhole Storage Tank underwent thorough metallurgical study due to the consequences of the bolt's malfunction during operation. Safety issues arose when the manhole door detached during operation. The mechanical testing and chemical composition analysis of the bolts indicated they were manufactured from an ASTM A193 Grade B7 material used for high-temperature bolting. This material did not conform to the engineering drawing, which mentioned SA 563A, which is about nuts, not bolts. This contradiction clearly shows that the eye bolt which was installed does not conform to the intended design. Welded connections of …

Rejection Of Fe (Iron) And Kmno4 (Organic Substance) Parameters In Peat Water Using Organic Membranes, Muhamad Rafli Sakti Mulia Gonera, Siti Umi Kalsum, Sarah Fiebrina Heraningsih

Journal of Materials Exploration and Findings

Peat water is a surface water source widely used by people in swampy and lowland areas, but it has poor quality characteristics such as high organic matter content, low pH, and dissolved metal levels such as iron that exceed the threshold. These conditions can cause health problems and reduce the quality of clean water so that effective treatment technology is needed. This study aims to analyze the effectiveness of ultrafiltration membranes made from chitosan from shrimp shell waste in rejecting iron (Fe) and organic substances in peat water, and to determine the effect of pressure on separation performance. This study …

Percolation-Induced Thermo-Rheological Transitions In Biobased Graphene Nanoplatelet Nanofluids, Abiodun A. Saka, Tobechukwu K. Abor, Anthony C. Okafor, Monday U. Okoronkwo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Biobased lubricants with thermally responsive rheology are increasingly needed for high-efficiency mechanical systems. Graphene nanoplatelet (GnP) nanofluids in vegetable oils are promising candidates, yet their percolation-driven thermo-rheological transitions remain insufficiently understood. In particular, the coupled concentration–temperature landscape controlling network-mediated flow transitions has not previously been established. Here, surfactant-free GnP nanofluids were prepared in high-oleic soybean oil (HOSO) at concentrations of 0.025–2.15% v/v (ϕ), and their rheological response was mapped between 25°C and 80 °C under steady-shear and oscillatory conditions. Below the percolation threshold (ɸ ≤ 0.1% v/v), the nanofluids exhibit near-Newtonian behavior, moderate reversible viscosity enhancement, and classical Arrhenius-type temperature …

Website: Home, Zhiqu Lu, Likun Zhang, Lei Cao

Gulf Research Program Data Sets

No abstract provided.

Website: Latest Results, Zhiqu Lu, Likun Zhang, Lei Cao

Gulf Research Program Data Sets

No abstract provided.

Website: News And Events, Zhiqu Lu, Likun Zhang, Lei Cao

Gulf Research Program Data Sets

No abstract provided.

Critical Core Technology Breakthroughs In Large-Scale Models: Industrialization Strategies And Policy Implications, Zhongqi Wu, Yinshan Liu, Tao Dai, Xiaolong Zheng

Bulletin of Chinese Academy of Sciences (Chinese Version)

As a pivotal direction for breakthroughs in key core technologies within the artificial intelligence domain, large-scale models hold strategic significance in securing national scientific and technological sovereignty. This study employs a multidimensional framework encompassing “technological breakthroughs, industrial transformation, and governance policies” to systematically investigate the developmental trajectories and industrialization bottlenecks of large-scale models. At the technological level, while large-scale models exhibit exponential growth in parameter scale and computing power demands, they face critical challenges including the scarcity of high-quality data, insufficient transfer learning capabilities, and reliability-explainability trade-offs. Industrially, these models are reshaping the global industrial chain landscape through a dual-track …

Evolutionary Trajectory Of Ai And Robotics Integration, Jiannan Zhu, Jianfeng Guo, Siyao Liu, Qi Cao

Bulletin of Chinese Academy of Sciences (Chinese Version)

The convergence of artificial intelligence (AI) and robotics is a cornerstone for the intelligent transformation of the physical world. This study conducts a systematic analysis of over 230,000 publications from the Web of Science and WIPO databases between 1982 and 2025 to dissect the evolutionary trajectory of AI and robotics integration since the 20th century. The findings identify four distinct developmental stages—independent exploration, functional coupling, primary intelligence, and intelligent symbiosis—while delineating the key technological breakthroughs and paradigm characteristics of each phase. Furthermore, seven core research thrusts are distilled, including motion planning and autonomous decision-making and perception & environmental understanding. An …

Developing Field And Spaceflight Microscopy, Nikki Johnston

Dissertations and Theses

Designing for spaceflight favors the reduction of unnecessary features and cost-cutting, whether thisbe computation, hardware, or procedure. Resources are spent toward fortification and mission success over convenience. Such design goals paired with the relatively smaller budgets of academia lead us to do as much as we can in-house and use open-source as much as we can without compromising mission success. We also believe that thoroughly testing technology in extreme environments on earth is necessary for the success of a flight instrument. We focus on microscopy for life detection. I have spent my time here learning methods of hand-building microscopes to …

Flexible Power Point Tracking For Active Frequency Regulation In Grid-Connected Photovoltaic Power Plants, Castor K. Haule, Sophia D. Kigodi, Emmanuel S. Matee, Francis Mwasilu

Tanzania Journal of Science

The increasing penetration of photovoltaic (PV) systems into modern power grids necessitates advanced control strategies capable of supporting grid stability. Traditional PV systems rely on Maximum Power Point Tracking (MPPT) to maximize energy extraction, limiting their ability to participate in grid-support functions such as frequency regulation or power curtailment. This paper presents a flexible power point tracking (FPPT) control strategy that enables PV systems to operate at arbitrary points along the power–voltage (P–V) curve. A multi-mode power management scheme is proposed, integrating conventional Perturb and Observe (P&O) MPPT with FPPT, allowing the system to switch dynamically between energy maximization and …

Optimization Of Gas Consumption, Cost And Production Rate For Computerized Numerical Control Oxy-Acetylene Flame Cutters, Eustace K. William, Simon I. Marandu, Enock W. Nshama

Tanzania Journal of Science

This study examined the impact of flame cutting parameters (i.e., cutting speed, plate thickness and nozzle diameter) on oxy-acetylene gas consumption, cost and production rate. A full factorial design of experiments was used to generate 27 experiments, which were conducted using a CNC flame cutter. The analysis of variance (ANOVA) method was used to determine significant process parameters, followed by regression analysis using the MINITAB ® software. The technique for order preference by similarity to ideal solutions (TOPSIS) was used to determine the optimal cutting parameters for minimizing the consumption and cost estimation of oxy- acetylene gas and maximizing the …

Mitigation Of Power Quality Problems In Songwe Power Distribution Line Using A Static Distribution Compensator, James Mhame, Emmanuel Matee, Francis Mwasilu, Sophia D. Kigodi

Tanzania Journal of Science

The Songwe electrical distribution system is prone to severe voltage drops that lead to frequent power outages in long feeders, light flickering, and the multi-operation of equipment and other appliances. The voltage at the switching station averaged 27.6 kV, 28.21 kV, and 25.79 kV in the years 2023, 2022, and 2021, respectively. Additionally, the maximum was 32.2 kV, below the nominal voltage, and the feeder has a very low power factor, which drops to 0.6 during peak hours. Currently, TANESCO uses automatic voltage regulators connected to a distant location from the switching station to two feeders with critical voltage drop …

Creating An Updated Risc-V Platform With Hypervisor Support, Carter A. Glatt

Masters Theses

Virtualization has become an important methodology for implementing security and efficiency in embedded systems design. Virtualized environments provide flexibility and scalability of user-space environments, as hardware capabilities allow for multiple environments to run concurrently using the same hardware without impacting system performance or cost metrics. The ability to implement virtualized environments is fundamentally based on the instruction set architecture (ISA), which implements the necessary commands to facilitate the interface between physical hardware and virtual components.

RISC-V is an open-source ISA that can be used to generate platforms that support virtualization through the use of the H-Extension ISA. Previous research into …

Structured And Interpretable Representations For Ensemble And Dynamical Systems, Yuan-Hung Kuan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Precise and robust manipulation of large populations of structurally identical dynamical systems with heterogeneous dynamics, known as ensemble systems, is a central challenge in many emerging applications. These systems are often difficult to analyze and control because of the inherent nonlinearities, high dimensionality, heterogeneity, and incomplete knowledge of the underlying dynamics. To address these challenges, this thesis develops structured and interpretable representations for the analysis, control, and learning of nonlinear ensemble systems. Its central objective is to transform complex heterogeneous dynamics into representations that preserve essential structural and dynamical properties while enabling tractable computation and effective control design. First, the …

Assessment Of The Radionuclide Concentration Levels Of Water And Sediments Along The Mara River, Gasper Kachenge, Abubakary Salama, Abdalah Kileo, Furaha Chuma

Tanzania Journal of Science

For many years, several factors have impacted the water quality of the Mara River, including population growth, agricultural expansion, livestock keeping, mining, and industrial activities. These factors have intensified water pollution and climate change effects around the river. While previous studies have mainly focused on assessing heavy metal pollution risks on the Mara River, this study evaluates the concentration levels of radionuclides in boreholes, water, and sediments along the river and its tributaries. Naturally occurring radioactive materials, including 226Ra, ²³²Th, and ⁴⁰K, were evaluated. A high-purity germanium radiation detector (HPGe) with a coaxial detector system coupled with Gamma Vision software …