Engineering Commons^™

Experimental Characterization Of Heat Transfer And Fluid Flow In Tcr Fuel Elements Under Varying Operational Conditions, El Mokhtar Majdoub Em

Dissertations and Theses

ABSTRACT

The Transformational Challenge Reactor (TCR) marks a significant leap forward in nuclear reactor innovation, focusing on modular construction, high efficiency, and improved safety. This research explores the coupled behavior of heat transfer and fluid flow within the TCR's 3D-printed ceramic core under varying operational conditions. Nitrogen was utilized as the cooling medium, with experiments carried out at pressures ranging from 300 to 600 psi and temperatures spanning 100°C to 300°C. Critical parameters, including inlet and outlet gas temperatures, wall temperatures at both ends of the core, and coolant flow rates were monitored to evaluate thermal performance and system reliability. …

Virtual Environment Creation And Camera Calibration For Soft Target Identification And Assistance In Crowded Spaces With A Sensor Network And A Robotic Dog, Eltan Samoylov

Dissertations and Theses

Crowded places are increasingly targets of violence due to the increased accessibility and covertness of weapons, explosives, and other technology like drones. Addressing the challenges of protecting crowded places and assisting vulnerable individuals requires a multidisciplinary approach, taking inspiration from many different perspectives. Video surveillance of these crowded public facilities, such as train and bus stations, airports, shopping malls, and sports arenas, is very important to public safety, both for identifying threats/terrorist attacks and implementing evacuation plans.

The work of this thesis is part of a larger project aiming to explore the potential of using real-time computer vision and deep …

Cfd Modeling And Simulation Of Natural Circulation In Helium- Cooled Very High Temperature Reactors, Mohammad Sakib U. Abrar

Dissertations and Theses

This thesis investigates the thermal-hydraulic behavior of natural circulation in helium-cooled Very High Temperature Reactor (VHTR) systems, focusing on the performance and validation of passive safety features under Pressurized or Depressurized Loss of Forced Cooling (P-LOFC or D-LOFC) events. An experimental facility inspired by the General Atomics 350 MWt Modular High Temperature Gas-Cooled Reactor (MHTGR) was developed at The City College of New York. The setup consists of a plenum-to-plenum flow loop with four riser and four downcomer tubes, each equipped with heating coils, thermocouples, and pressure sensors. Natural circulation is driven by density gradients induced by asymmetric heating of …

Characterization Of The Intrinsic Neural Timescale Indices As A Reliable Fingerprint Of Brain Dynamics, Helya Honarpisheh

Dissertations and Theses

Intrinsic neural timescales (INTs) characterize the persistence of neural activity over time and offer insight into the brain’s temporal hierarchy. This thesis evaluates and compares six autocorrelation-based INT metrics—AR(1) Coefficient (Autoregressive Coefficient at 1), First Zero Lag, Lag at ACF = 1/e, Sum of Positive ACFs, ACF at Half Lag, Exponential Decay Constant (τ)— using resting-state fMRI data from 400 cortical regions across a large, lifespan sample (ages 6– 85) from the NKI-Rockland dataset. A discriminability analysis revealed that the AR(1) coefficient provided the highest test-retest reliability and individual specificity across repeated scans, establishing it as the most reliable INT …

Metasurfaces And Their Applications In Photonic Devices, Shuwei Guo

Dissertations and Theses

Metasurfaces are flat artificial optical elements composed of dielectric and/or metallic nanostructures. They can manipulate light in unprecedented ways by altering amplitude, phase, and polarization at subwavelength scales. The ability of these two-dimensional elements to perform multiple optical functions within compact optical systems—while offering high functionality, small form factors, and easy integration into optoelectronic devices—has sparked significant interest across various fields and industries. These applications span imaging, sensing, nonlinear and quantum optics, optical computing, automotive technology, augmented and virtual reality, and more.

In this dissertation, we explore and design new multifunctional metasurfaces with a focus on manipulating spectral responses. First, …

Cognitive Map Generation For Vision And Language Navigation, Alexander Sandoval Mesa

Dissertations and Theses

Visual-Language Navigation (VLN) presents significant challenges for autonomous agents, such as robots and virtual assistants, particularly in complex, dynamic environments where the seamless integration of visual perception and natural language understanding is critical. Traditional VLN systems often struggle with effectively aligning language instructions and visual scene understanding, limiting their adaptability and navigation efficiency.

This thesis proposes a novel Cognitive Map-based framework that addresses these challenges by transforming natural language navigation instructions into structured graph representations. The Cognitive Map consists of nodes representing waypoints, landmarks, decision points, and edges encoding spatial relationships and navigational actions. These maps are generated using Large …

Multi-Material Adhesive Bonded Joints Under Static And Dynamic Loading, Gizem Derya Demir

Dissertations and Theses

Adhesively bonded joints present significant potential for reducing structural weight and enhancing performance in modern and future engineering structures. By enabling the elimination or reduction of traditional mechanical fasteners and facilitating the integration of dissimilar materials, adhesives can contribute to more efficient, lightweight designs. However, to fully leverage these benefits—especially in high-performance applications—adhesive materials must exhibit robust behavior under both static and dynamic loading conditions, such as ballistic impact. Despite their promise, the failure mechanisms of adhesives under such high-strain-rate scenarios remain insufficiently understood.

This dissertation investigates the performance of adhesively bonded multi-material joints subjected to static loading and ballistic …

Data Driven Bridge Deck Deterioration Modeling And Maintenance Intervention Scheduling, Deepak Kumar

Dissertations and Theses

Majority of over 617,000 bridges across the United States are significantly impacted by environmental factors, aging materials, and heavy traffic loads. According to the 2021 Infrastructure Report, nearly 231,000 bridges require repair or preservation work, with 46,154 (7.5%) being classified as structurally deficient, thereby posing risks for mor than 178 million daily trips across these bridges. Despite recent improvements, 42% of U.S. bridges are at least 50 years old, underscoring an urgent need for increased investment to meet repair demands. The nation’s backlog of bridge repairs is estimated at $125 billion, with a 58% increase in annual spending required to …

Generation And Characterization Of Human Blood-Brain Barrier Models For Investigating Neuropsychiatric Disorders And Tumor Metastasis, Yunfei Li

Dissertations and Theses

The blood–brain barrier (BBB) is important in the normal function of the central nervous system (CNS). An altered BBB has been described in various neuropsychiatric disorders. The brain-specific microvascular endothelial cell (BMEC) is an essential structural component of the BBB. To test if integrity of the BBB formed by BMECs is compromised in 22q11.2 deletion syndrome (also called DiGeorge syndrome), which is one of the validated genetic risk factors for schizophrenia, a 2D iBBB (induced BBB) on a Transwell filter was generated from human microvascular endothelial cells (HBMECs) derived from the induced pluripotent stem cells (iPSCs) out of patients with …

Experimental And Analytical Investigation Of Particle Dynamics In Newtonian And Non-Newtonian Fluids In A Taylor-Couette Cell, Andres F. Velez Mendoza

Dissertations and Theses

This doctoral dissertation investigates heavy particle sedimentation in Newtonian and non-Newtonian fluids, aiming to understand their behavior in Drilling Fluid (DF) systems used in oil and gas industry, where such phenomenon can lead to operational issues such as lost circulation, well control problems, and even blowouts. To simulate DF dynamics under operational conditions, this study utilizes a Taylor-Couette (TC) cell, which consists of a rotating inner cylinder and a stationary outer cylinder separated by a 9.0 mm annular gap. The TC cell allows for the investigation of the sedimentation behavior of spherical particles within both Newtonian fluids (deionized water and …

Deep Learning Architectures For Improving Weather Research And Forecasting (Wrf) Precipitation Estimates And Landslide Susceptibility Mapping: A Case Study Of Puerto Rico, Said A. Mejia Manrique

Dissertations and Theses

Precipitation is a critical factor in the Earth’s hydrological cycle and has a profound impact on various environmental and socioeconomic systems, including management of water resources, flood forecasting, and the evaluation of natural hazards, particularly those associated with rainfall-induced landslides. For the latter, obtaining precise precipitation estimates is essential, as intense rainfall events can trigger landslides that pose significant risks to human life, infrastructure, and ecosystems, particularly in mountainous regions. Puerto Rico (PR), with its mountainous terrain, tropical climate, and vulnerability to hurricanes, provides a unique environment for studying precipitation patterns and the need for accurate rainfall estimates. The complex …

Software, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

Agenda

• Workflow
• Version Control
• Reviews
• Testing
• Constraints
• Concepts
• Assurance

Test And Integration Facilities And Equipment Eat, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

Agenda

• Hardware Protection

• Why, When and How

• Hardware protection breakdown

• ESD

• Cleanrooms

• Procedures

• Training

• Hardware Handling

• School Equipment Guidance

• Training References

Defense In Depth Exercise (Didex) 25: Technology Quad Chart, Kori Moore, Troy Johnson

Space Dynamics Laboratory Publications

SDL poster for DiDEX 25

Assembly, Integration And Test, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

What is “AI&T”

• A continuous, iterative process of turning low level components into the system of hardware, software and ground tools that meet YOUR mission

• Teaching the engineering team to UNDERSTAND the system they’ve built

• It does exactly what it was designed to do, now figure out what that was…

• Verifying mechanical, electrical, data and software interfaces

• Does it fit?
• Does it talk?
• Is it on?

Advanced Doppler Wind And Temperature Sounder, Trent Newswander, Scott Bailey, Mark Hervig, Phillip Scott, Zack Hatfield

Space Dynamics Laboratory Publications

Introduction

• An advanced Doppler Wind and Temperature Sounder (DWTS) is being developed for flight on NASA’s Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC) satellite

– Will provide the first comprehensive global dataset of winds and temperature in the mesosphere and thermosphere (40–250 km altitude)

– Designed and built by Space Dynamics Lab (SDL)

• The DYNAMIC mission aims to characterize the energy transfer between the ionosphere, thermosphere, and mesosphere

– Led by Scott Bailey from Virginia Polytechnic Institute and Sate University

– See his HELIOTECH DYNAMIC poster for more details

• DWTS observes the Doppler shift of atmospheric NO and ^{13 …}

Electrical Power System (Eps) Overview, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

UNP Presentation on Electrical Power Systems

F-Layer Parameters Derived By Airglow Emissions At Pituffik Sb, Greenland, Jessica Norrell, Ivana Molina, Michael Negale, Jeffrey Holmes

Space Dynamics Laboratory Publications

Atomic oxygen airglow has long been used as tracer for the peak height and electron density of the F-layer (e.g. Sahai et al., 1981). Tinsley and Bittencourt (1975) described a method by which OI airglow is used to determine F-layer parameters. They found that the square root of the column emission rate of an optically thin layer created by radiative recombination emission was proportional to the peak electron density of the F-layer.

An all-sky imager (ASI) was recently installed at Pituffik, Greenland (76.51˚N, 68.74˚W), with four filters relevant to this study: 5725, 6300, 7715 and 7774 Å. We have used …

Autonomy For Dark Swarms In Degraded Environments, Thomas J. Walls, Brad Petersen, Matt Didericksen

Space Dynamics Laboratory Publications

A system that manages electromagnetic emissions and signature by design to avoid detection

Ai Simulation Creation, John P. Wilson

Space Dynamics Laboratory Publications

Introduction - AI Simulation Creation

• Exploring the use of Artificial Intelligence (AI) in the form of a Large Language Model (LLM) to produce a simulation of a factory production facility with given parameters and calculated performance.
• Use Grok (Grok 4 Expert) and Claude (Sonnet 4.5) LLMs 
• Ask the LLMs to solve the problem analytically and then create a Python simulation to calculate the results.
• Answer the questions: 
• Can an AI do this?
• How do the results compare?

Delivering Mission Success, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SDL Presentation on Delivering Mission Success

100 Days, Phil Hale

Space Dynamics Laboratory Publications

Organizational Overview

Total Employees: 1367

Command & Data Handling, Firmware & Software, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

UNP Presentation on Command & Data Handling, Firmware & Software

Work Experience At Space Dynamics Laboratory Summer 2025, North Logan, Erik Johnson

Space Dynamics Laboratory Publications

Space Dynamics Laboratory (SDL) is owned by Utah State University and is a non-profit organization. Their headquarters are in North Logan and have over 1,200 employees. SDL is a University Affiliated Research Center (UARC), that delivers custom engineering solutions in the military, space, and science industries.

Qualification Of Titanium 3d-Printed Volume-Optimized Propulsion Tanks For Small Satellites, Robert M. Fowler

Space Dynamics Laboratory Publications

SDL presentation on Titanium 3D-Printed Volume-Optimized Propulsion Tanks for Small Satellites

Time-To-Digital Conversion In The Lattice Certuspro Fpga For The Cape Instrument, Zakk B. Rhodes, James Cook, Cameron Weston, Daniel J. Gershman

Space Dynamics Laboratory Publications

A time-to-digital conversion (TDC) algorithm is implemented in a Lattice CertusPro FPGA to measure time differences between two incident pulses for science data acquisition in the CAPE instrument on NASA’s GDC mission. CertusPro provides sub-100 picosecond resolution with nearly linear results which is discussed with its other unique characteristics. Performance measurements and variation in timing due to parameters such as core voltage and temperature are presented.

Celis: Compact Eyesafe Lidar System, A Portable 1.5 Μm Elastic Lidar System For Rapid Aerosol Concentration Measurement: Part 2, Retrieval Of Particulate Matter Concentration, Kori D. Moore, Alan W. Bird, Michael D. Wojcik, Robert Lemon, Jerry L. Hatfield

Space Dynamics Laboratory Publications

SDL Poster on the CELiS Compact Eyesafe Lidar System

Using Distributive Networks Of Single-Frequency Hf Transmitters And Receivers To Measure Spatial And Temporal Ionospheric Perturbations, Riley Troyer, Kenneth Obenberger, Ivana Molina, Eugene Dao, Zsolt Balint, Eric Burnside, Kris Robinson, Jeffrey Holmes, Pavel Inchin, Jonathan Snively

Space Dynamics Laboratory Publications

We can track ionospheric disturbances using networks of single-frequency HF receivers. How can we best utilize these systems and networks?

High-Performance Small Satellites For Demanding Missions, Lance Fife

Space Dynamics Laboratory Publications

SDL Presentation on High Performance Small Satellites

Principles Of Modular Open Architectures For Enabling Future Capabilities, Jacob Christensen

Space Dynamics Laboratory Publications

What is Modular Open Architecture?

Vision

• Modular Open Architectures enable affordable and evolutionary capabilities

Principles

• Employ Modular Design
• Designate Key Interfaces
• Select Open Standards

Benefits

• Reduce schedule
• Reduce cost
• Faster upgrades
• Enhanced interoperability
• Increased competition
• Increased innovation