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Computational Study Of Rotating Detonation Combustors, Aditya Balasubramaniam

Mechanical and Aerospace Engineering Theses

Rotating detonation combustors (RDCs) are pressure-gain combustion devices that sustain one or more continuously rotating detonation waves, offering potential thermodynamic and performance advantages over conventional deflagration-based systems. Their behavior depends strongly on combustor geometry and operating conditions. Understanding these effects is therefore essential for the design and optimization of practical RDCs. Accordingly, this thesis numerically investigates annular RDCs with two primary objectives: (1) to evaluate the effects of propellant mass flux and (2) to assess the influence of annular width on detonation-wave dynamics and combustor performance.

A finite-volume framework is used to solve the compressible reactive Euler equations with hydrogen–air …

The Hitran2024 Molecular Spectroscopic Database, I. E. Gordon, L. S. Rothman, R. J. Hargreaves, F. M. Gomez, T. Bertin, C. Hill, R. V. Kochanov, Y. Tan, P. Wcisło, V. Yu. Makhnev, P. F. Bernath, M. Birk, V. Boudon, A. Campargue, A. Coustenis, B. J. Drouin, R. R. Gamache, J. T. Hodges, D. Jacquemart, E. J. Mlawer, A. V. Nikitin, V. I. Perevalov, M. Rotger, S. Robert, J. Tennyson, G. C. Toon, H. Tran, V. G. Tyuterev, E. M. Adkins, A. Barbe, D. M. Bailey, K. Bielska, L. Bizzocchi, T. A. Blake, C. A. Bowesman, P. Cacciani, P. Čermák, A. G. Császár, L. Denis, S. C. Egbert, O. Egorov, A. Yu. Ermilov, A. J. Fleisher, H. Fleurbaey, A. Foltynowicz, T. Furtenbacher, M. Germann, E. R. Guest, J. J. Harrison, J. -M. Hartmann, A. Hjältén, S. -M. Hu, X. Huang, T. J. Johnson, H. Jóźwiak, S. Kassi, M. V. Khan, F. Kwabia-Tchana, T. J. Lee, D. Lisak, A. -W. Liu, O. M. Lyulin, N. A. Malarich, L. Manceron, A. A. Marinina, S. T. Massie, J. Mascio, E. S. Medvedev, V. V. Meshkov, G. Ch. Mellau, M. Melosso, S. N. Mikhailenko, D. Mondelain, H.S.P. Müller, M. O' Donnell, A. Owens, A. Perrin, O. L. Polyansky, P. L. Raston, Z. D. Reed, M. Rey, C. Richard, G. B. Rieker, C. Röske, S. W. Sharpe, E. Starikova, N. Stolarczyk, A. V. Stolyarov, K. Sung, F. Tamassia, J. Terragni, V. G. Ushakov, S. Vasilchenko, B. Vispoel, K. L. Vodopyanov, G. Wagner, S. Wójtewicz, S. N. Yurchenko, N. F. Zobov

Chemistry & Biochemistry Faculty Publications

The HITRAN database is a curated compilation of validated molecular spectroscopic parameters, established in the early 1970s. It is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of six major components. These components include the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimentally derived absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally …

References, Appendices & All Parts Merged, Konstantin Likharev

Essential Graduate Physics

Includes: Appendix MA: Selected Mathematical Formulas; Appendix UCA: Selected Physical Units and Constants; References; EGP merged file (all parts, appendices, and references)

The Scattering Algebra Of Physical Space: Squared Massive Constructive Amplitudes, Moab Croft, Neil Christensen

Faculty publications – Physics

The Algebra of Physical Space (APS) is used to explore the Constructive Standard Model (CSM) of particle physics. Namely, this paper connects the spinor formalism of the APS to massive amplitudes in the CSM. A novel equivalency between traditional CSM and APS-CSM formalisms is introduced, called the Scattering Algebra (SA), with example calculations confirming the consistency of results between both frameworks. Through this all, two significant insights are revealed: The identification of traditional CSM spin spinors with Lorentz rotors in the APS, and the connection of the CSM to various formalisms through ray spinor structure. The CSM’s results are …

Amorphous Selenium Photodetectors For Liquid Noble Detectors, Michael Rooks

Physics Dissertations - Archive

Physics offers a way to connect deeply with the mysteries that surround us. Advances in detector physics, particularly in neutrino experiments and rare-event searches, have expanded our ability to probe phenomena that challenge how we describe the universe. Each discovery brings us closer to understanding the unknown, returning us to a sense of wonder that motivates exploration. My work on detector technology was inspired by a concept paper from Professor David Nygren, in which he noted the speculative possibility of integrating photon detection into a charge readout for pixelated liquid argon time projection chambers (LArTPCs) using the photoconductor amorphous selenium …

Wiener-Granger Causality To Model Banking Sector Contagion, Riya Bhasin

CMC Senior Theses

In this thesis, we explore the main drivers behind the 2008 Global Financial Crisis and how the interconnectivity of banking sectors contributed to the worldwide spread of its effects. To understand how this became a global phenomenon, we apply linear Wiener-Granger Causality as a form of network analysis, building on pre-existing methodology in order to study continent banking indices. We find connections across locales on the continent and country level, but ones that are weak. Our modelling was insufficient to completely capture existing and well-known relationships accurately. This occurs due to limitations of the data and of the linear models’ …

Part Qm: Quantum Mechanics, Konstantin Likharev

Essential Graduate Physics

Includes: Introduction; 1D Wave Mechanics; Higher Dimensionality Effects; Bra-ket Formalism; Some Exactly Solvable Problems; Perturbation Theories; Open Quantum Systems; Multiparticle Systems; Introduction to Relativistic Quantum Mechanics; Making Sense of Quantum Mechanics

Part Cm: Classical Mechanics, Konstantin Likharev

Essential Graduate Physics

Includes: Review of Fundamentals; Lagrangian Formalism; A Few Simple Problems; Oscillations; From Oscillations to Waves; Rigid Body Motion; Deformations and Elasticity; Fluid Mechanics; Deterministic Chaos; A Bit More of Analytical Mechanics

In Situ Observations Of Thermal Ions In Perturbed Ionospheres: Techniques And Results, Magdalina Louise Moses

Dartmouth College Ph.D Dissertations

Prediction and mitigation of space weather events are active research topics that require knowledge of the physics governing the ionosphere. Sounding rockets can be used to make in situ observations. The Lynch Rocket Lab created the Petite-Ion-Probe (PIP), a small retarding potential analyzer, to measure thermal ion parameters (i.e., ion density and temperature). A PIP's raw data consists of a series of measured anode currents as a function of screen bias voltages, called IV curves. PIPs can be integrated onto a sounding rocket’s main payload and/or be deployed from the rocket on small platforms called ``PIP-Bobs''. Note that as the …

Basis Design For Electronic Structure And Beyond, Weishi Wang

Dartmouth College Ph.D Dissertations

At the intersection of quantum physics, quantum chemistry, and materials science, electronic structure is the study of electrons in solid-state and molecular systems. Electronic-structure computation relies on discretizing the many-electron Hamiltonian with a finite single-particle basis set. However, basis-set construction is conventionally treated as an ad hoc preprocessing step. This thesis develops an expressive and flexible framework for active, system-oriented basis-set design and numerical modeling strategies that treat basis functions as tunable representations to encode electronic ground-state information.

We first introduce a multi-layered, differentiable basis-construction framework that embeds a set of primitive parameters into mixed-contracted Gaussian-type orbitals. We then develop …

Hyena: An Observing System Simulation Experiment For Hypothetical Energetic Neutral Atom Imagers, Joel Tibbetts, Amy Keesee, Matina Gkioulidou, Robert Demajistre, Viacheslav Merkin

Faculty Publications

Mesoscale plasma sheet flows are widely understood to be a critical component of the overall picture of energy, particle, and magnetic flux transport during periods of geomagnetic activity. Without simultaneous measurements with true global coverage, the short lifetime (~10 min) and localized spatial extents (~1–3 R_E in azimuth) of these structures make obtaining a global picture of their contributions to stormtime magnetosphere dynamics difficult to characterize. Energetic neutral atom (ENA) imaging can enable remote mapping of plasma energization in the magnetosphere; however, its line-of-sight integrated nature, coupled with the challenging-to-characterize attributes of the target physical phenomena, means that numerous …

First-Principles And Thermodynamic Modeling Of Hydrogen Storage In Mxenes, Yi Zhi Chu

Dissertations, Master's Theses and Master's Reports

Hydrogen storage is a critical component of the emerging hydrogen economy, playing a central role in enabling the global transition from fossil fuels to a sustainable, green energy system. With advances in materials research, increasing attention has been directed toward the development of promising hydrogen storage materials. Due to their diverse and advantageous physicochemical properties, MXenes have attracted significant interest in this regard. A fundamental understanding of the hydrogen interactions with the MXenes structure is crucial for explaining and predicting their hydrogen storage performance. In this work, first-principles density functional theory (DFT) combined with a revised thermodynamic model is employed …

First-Principles Investigation Of Quasi-One-Dimensional Van Der Waals Magnets For Advancing Low-Dimensional Spintronics, Alyssa Horne

Dissertations, Master's Theses and Master's Reports

Van der Waals (vdW) magnets have been of great interest for advancing low- dimensional spintronics. A notable example is the quasi-one-dimensional (Q1D) vdW CrSbSe₃, as it is composed of individual one-dimensional units that are held together by the vdW forces. Finding other Q1D vdW magnets that exhibit non-metallic behavior together with long range ferromagnetic ordering is critical in developing next generation spintronics. Here in, using first-principles density functional theory (DFT), we investigate the compositional effects on electronic and magnetic behavior of Cr_1–xMn_xSbSe₃ (x = 0, 0.5, 1). When 50% of Cr is replaced …

Part Sm: Statistical Mechanics, Konstantin Likharev

Essential Graduate Physics

Includes: Review of Thermodynamics; Principles of Physical Statistics; Ideal and Not-So-Ideal Gases; Phase Transitions; Fluctuations; Elements of Kinetics

Laser Beam Shaping Using A Neural Network, Azeem A. Hakim

Honors Undergraduate Theses

Multiphoton lithography (MPL) is a method of laser-based 3D-printing for fabricating micron-scale structures point-by-point in a photopolymerizable medium. MPL’s high-resolution capabilities have made it a powerful method for the fabrication of many devices, such as microelectromechanical systems (MEMS) and tissue scaffolds.  The throughput of MPL processes can be increased by using spatially shaped laser beams that expose large areas or volumes simultaneously. A laser beam can be reshaped by passing it through a spatial light modulator (SLM) displaying a pre-designed phase mask. One type of laser beam profile used for this purpose is the Bessel beam, a type of structured …

Physics-Informed Temperature Prediction Of Lithium-Ion Batteries Using Decomposition-Enhanced Lstm And Bilstm Models, Seyed Saeed Madani, Yasmin Shabeer, Michael Fowler, Satyam Panchal, Carlos Ziebert, Hicham Chaoui, François Allard

Electrical & Computer Engineering Faculty Publications

Accurately forecasting the operating temperature of lithium-ion batteries (LIBs) is essential for preventing thermal runaway, extending service life, and ensuring the safe operation of electric vehicles and stationary energy-storage systems. This work introduces a unified, physics-informed, and data-driven temperature-prediction framework that integrates mathematically governed preprocessing, electrothermal decomposition, and sequential deep learning architectures. The methodology systematically applies the governing relations to convert raw temperature measurements into trend, seasonal, and residual components, thereby isolating long-term thermal accumulation, reversible entropy-driven oscillations, and irreversible resistive heating. These physically interpretable signatures serve as structured inputs to machine learning and deep learning models trained on temporally …

Mtl_Tx: A Multi-Task Transformer Model For Improved Radiation Time-Series Estimation, Hongfang Zhang, Adam Stavola, Hal Ferguson, Bence Budavari, Hongyi Wu, Chiman Kwan, Jiang Li

Electrical & Computer Engineering Faculty Publications

Controlling radiation doses at potential radioactive facilities is critical to ensuring the safety of both personnel and the public. At the Thomas Jefferson National Accelerator Facility (JLab), multiple sensors are deployed around the three experimental halls to monitor key parameters, including single-beam current, energy levels, current leakage, and radiation values during accelerator operations. In this study, we developed a Multi-task Transformer model, MTL_TX, to accurately estimate radiation doses at sensor locations based on historical data, with the aim of enhancing safety in accelerator facilities and surrounding public areas. To improve estimation accuracy, we integrated two innovative components into the proposed …

Utilizing Computer Modeling To Optimize Electric Fields Within Xenon Time Projection Chambers, Miles Meloni

Honors Theses

XENONnT is a physics experiment designed with the goal of detecting dark matter particles. The detector is a time projection chamber; a series of charged electrodes creates an electric field, surrounding a central body filled with liquid and gaseous xenon. Photomultiplier tubes (PMTs), positioned on either end of the chamber, serve to detect light signals. We seek to minimize the root mean square of the electric field norms experienced by the PMTs. This quantity corresponds to the variance in the electric field observed by the PMTs. Establishing a consistent electric field is important to maintaining these sensitive components. The electric …

Large Aerosol Particles Favor Haze Conditions Through Limitations On Water Budget And Activation Kinetics, Hamed F. Sadi, Ernie Lewis, Kadja Flore Gali, Fan Yang, Jesse Anderson, Suryadev Pratap Singh, Jae Min Yeom, Will Cantrell, Raymond Shaw

Michigan Tech Publications

Experiments in the Pi Convection‐Cloud Chamber conducted by systematically changing the diameter of injected dry aerosol particles while holding the temperature difference constant demonstrate that dry diameter strongly influences the onset of haze‐dominated conditions. Two factors contribute: the system becomes water‐limited, resulting in reduction of supersaturation by growing aerosol particles to the activation diameter; and the activation process becomes kinetically limited. Dry aerosol diameter exerts a strong influence on activation time, with a power‐law exponent of 9/2. Kinetically limited activation occurs when the ratio of the activation and droplet residence times is greater than unity. The findings demonstrate that a …

First Remi Experiments At A Cryogenic Ion Storage Ring, M. Schulz, F. Herrmann, W. Zhang, A. Dorn, M. Grieser, F. Grussie, H. Kreckel, O. Novotny, A. Wolf, T. Pfeifer, C. D. Schröter, R. Moshammer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We have recorded double, triple, and quadruple coincidences between neutralized projectiles, recoiling target ions, and two electrons created in collisions of slow anions with neutral atoms. The experiments were performed at the cryogenic storage ring in Heidelberg. The recoil ions and ejected electrons were momentum-analyzed using a Reaction Microscope (ReMi) spectrometer. Various processes involving electron detachment from the projectile accompanied by various transitions in the target were investigated. Detachment without any transition in the target is qualitatively well described by a quasi-free electron model in the case of an Ar target. In detachment with single target ionization, no signatures of …

Ultra-Low Noise Ion Detection For Neutrinoless Double Beta Decay Searches, Karen E. Navarro

Physics Dissertations

Neutrinos are the most abundant particles in the universe that carry mass. Yet, we know very little about them since they are electrically neutral and interact weakly. A small instance after the Big Bang, an imbalance occurred that caused matter to be produced in greater quantities than antimatter. A leading candidate for this unexplained process is leptogenesis. Leptogenesis predicts that neutrinos are Majorana particles: a particle that is its own antiparticle. Today, particle detectors are being constructed to search for this property through the yet unobserved neutrinoless double beta decay (0νββ) . If observed, this would demonstrate that neutrinos are …

Bursty Bulk Flows: The What, The Why, And Their Impacts On The Earth, Fariza Tanvir

2026 Spring Honors Capstones Projects

Due to solar wind-magnetosphere interactions, the Earth's magnetic field lines stretch into a long, comet-shaped magnetotail, which extends thousands of miles away from the Earth. Bursty Bulk Flows (BBFs) are transient, high-speed ion bulk flows in the magnetotail that play an essential role in energy and mass transport. Characterized by their short-lived duration, they are related to magnetic reconnection events. This investigation focuses on being able to identify BBFs using the Magnetospheric Multiscale (MMS) probes, a mission consisting of four probes arranged in a tetrahedron to study the Earth’s magnetosphere. We examine parameters such as energy spectra, spin bulk velocity, …

Microgravity-Induced Alterations In Left Atrial Hemodynamics And Thrombogenic Risk: Insights From Healthy And Atrial Fibrillation Models, Grace M. Hoeppner

Dissertations, Master's Theses and Master's Reports

Background: Microgravity exposure alters cardiovascular loading, yet its impact on left atrial flow dynamics and thrombotic risk remains poorly understood. This study investigates how spaceflight-relevant microgravity-induced changes in cardiac outflow affect left atrial hemodynamics in healthy individuals and patients with atrial fibrillation.

Methods: Patient-specific left atrial models were generated for three healthy individuals and three AF patients. Computational fluid dynamics (CFD) simulations were performed using each patient’s baseline mitral outflow waveform and two modified waveforms representing short- and long-duration post-flight cardiac loading changes derived from echocardiographic observations. Hemodynamic metrics included left atrial velocity, time averaged wall shear stress, oscillatory shear …

Physics-Based Multi-Hazard Fragility Modeling Of Low-Rise Wood-Frame Buildings Under Hurricane-Induced Wind And Surge, Mumtasirun Nahar, Abdullah M. Braik, Mohammad Syed, Maria Koliou, Petros Sideris

Civil & Environmental Engineering Faculty Publications

Coastal buildings are exposed to concurrent hurricane-induced wind and storm surge, yet their vulnerability is commonly assessed using separate single-hazard models that neglect hazard interaction. This study developed a physics-based finite element framework to evaluate the performance of a low-rise light wood-frame building under simultaneous wind and surge-wave loading. A detailed three-dimensional model was constructed using a sub-assembly strategy that explicitly represented framing members, sheathing systems, and critical connections. Structural response was evaluated across a hazard space defined by wind speed, still-water depth, and flow velocity, and component- and system-level fragility functions were derived using Monte Carlo simulation and generalized …

Connecting The Existing Fiber Infrastructure To The Future With Antiresonant Hollow Core Fibers, Timothy Bate

Graduate Studies Theses and Dissertations 2026

Optical fiber systems based on solid-core silica waveguides underpin modern telecommunications, high-power laser delivery, precision sensing, and coherent optical systems. However, nonlinear effects, material absorption, and thermal limitations within silica increasingly constrain further scaling in both optical power and transmission performance. Antiresonant hollow-core fibers provide a promising alternative by guiding light predominantly in air, substantially reducing nonlinear interactions, latency, and optical damage while enabling transmission regimes inaccessible to conventional solid-core fibers. Despite rapid advances in antiresonant hollow-core fiber attenuation and power handling, one of the largest remaining barriers to widespread adoption is reliable integration with the existing solid-core fiber ecosystem. …

1-D And 2-D Hadamard Transformations For Protein Sequence Analysis, Esraa A. Ahmed, Abed M. Nasr, Marwa A. Abd Elwahaab

Mansoura Engineering Journal

Similarity/dissimilarity studies follow alignment-based or alignment-free methods. Many alignment-free methods involve selecting physicochemical properties. Most previous articles don’t explain their criteria for choosing the properties used. These heuristic approaches have, by definition, undeterministic and unreliable performance. Hence, there is a need for a powerful proxy for similarity/dissimilarity by a deterministic, reliable approach.

In this study, a physicochemical property is selected by a multi-criteria sequential selection process. The amino acids composing any protein sequence are replaced with their values of the chosen property to produce a discrete signal in the time domain.  The one-dimensional discrete Hadamard transforms our signal from the …

High-Efficiency And Compact Virtual Reality Displays, Zhenyi Luo

Graduate Studies Theses and Dissertations 2026

Virtual reality (VR) and augmented reality (AR) technologies are revolutionizing the way humans interact with digital information. However, current near-eye display systems still face critical challenges regarding optical efficiency, image quality, and device weight. This dissertation focuses on addressing these limitations through innovative liquid-crystal (LC) optics and system-level design strategies to achieve high-efficiency and compact VR displays.

First, to solve the longstanding problem of severe chromatic aberrations in ultrathin LC optics, I proposed an achromatic diffractive LC device. By stacking three LC layers with specifically designed spectral responses and polarization selectivity, I successfully reduced the chromatic aberrations. This idea enables …

Explainable Physics-Based Constraints On Reinforcement Learning For Accelerator Optimization, Jonathan Colen, Malachi Schram, Kishansingh Rajput, Armen Kasparian

Data Science Faculty Publications

We present a reinforcement learning (RL) framework for optimizing particle accelerator experiments that builds explainable physics-based constraints on agent behavior. The goal is to increase transparency and trust by letting users verify that the agent’s decision-making process incorporates suitable physics. Our algorithm uses a learnable surrogate function for physical observables, such as energy, and uses them to fine-tune how actions are chosen. This surrogate can be represented by a neural network or by an interpretable sparse dictionary model. We test our algorithm on a range of particle accelerator optimization environments designed to emulate the Continuous Electron Beam Accelerator Facility at …

Evidence For A Spectral Break Or Curvature In The Spectrum Of Astrophysical Neutrinos From 5 Tev To 10 Pev, Karen Andeen

Physics Faculty Research and Publications

We report improved measurements of the all flavor astrophysical neutrino spectrum with IceCube by combining complementary neutrino samples in two independent analyses. Both analyses show evidence of a harder spectrum at energies below  ∼30  TeV compared to higher energies where the spectrum is well characterized by a power law. The spectrum is better described by a log parabola or a broken power law, the latter being the preferred model. Both, however, reject a single power law over an energy range 5 TeV–10 PeV with a significance  >4⁢𝜎, providing new constraints on properties of cosmic neutrino sources.

Spectral Phase Pulse Shaping Alters Photoionization Time, James Aygun, Dany Yaacoub, Allison L. Harris

Faculty publications – Physics

Photoionization is a key step in many attosecond processes. Accurately determining the photoionization time delay is critical to understanding electron dynamics during and after ionization and can guide future efforts to manipulate electron motion. Prior studies have shown that the photoionization time delay is non-zero and that pulse shaping through alteration of the spectral phase may change the number and timing of ionization events. In order to assess whether and how the spectral phase modifies the photoionization time delay, we use attosecond streaking simulations to extract the streaking time delay for ionizing pulses with identical power spectra, but different spectral …