Digital Commons Network^™

A Model Intercomparison Study Of Aerosol-Cloud-Turbulence Interactions In A Cloud Chamber: 1. Model Results, Sisi Chen, Steven K. Krueger, Piotr Dziekan, Kotaro Enokido, Theodore Macmillan, David Richter, Silvio Schmalfuß, Shin Ichiro Shima, Fan Yang, Jesse C. Anderson, Will Cantrell, Dennis Niedermeier, Raymond Shaw, Frank Stratmann

Michigan Tech Publications

This study presents the first model intercomparison of aerosol-cloud-turbulence interactions in a controlled cloudy Rayleigh-Bénard Convection chamber environment, utilizing the Pi Chamber at Michigan Technological University. We analyzed simulated cloud chamber-averaged statistics of microphysics and thermodynamics in a warm-phase, cloudy environment under steady-state conditions at varying aerosol injection rates. Simulation results from seven distinct models (DNS, LES, and a 1D turbulence model) were compared. Our findings demonstrate that while all models qualitatively capture observed trends in droplet number concentration, mean radius, and droplet size distributions at both high and low aerosol injection rates, significant quantitative differences were observed. Notably, droplet …

The Response Of Mitochondrial Position To Glucose Stimulation In The Min6 Model System, Luis Perez

Arts & Sciences Graduate Student Theses and Dissertations

The compartmentalization of eukaryotic cells into membrane-bound organelles with specific subcellular positioning enables precise spatial and temporal control of cellular functions. While functionally significant mitochondrial localization has been demonstrated in cells such as neurons, it remains unclear how general these cell principles are. Here, we examine the spatial organization of mitochondria within MIN6 pancreatic beta cells under variable glucose conditions. We observe glucose-dependent redistributions of mitochondria, favoring peripheral localization at elevated glucose levels when insulin secretion is also elevated. Our results suggest that active mitochondrial transport along microtubules and calcium activity, but not ATP synthesis, are critical regulators of this …

Stokes-Dependent Droplet Collection Efficiency On A Naca 0012 Airfoil From Droplet-Informed Simulations With Statistical Overloading, Arash Shad, Hashnayne Ahmed, ‪Nadim Zgheib, S. Balachandar, S. A. Sherif

Mechanical Engineering Faculty Publications

Accurate modelling of ice accretion on aircraft wings requires analysing droplet impingement on the surface to optimize the design of ice-protection systems. We perform Euler–Lagrange simulations of a droplet-laden flow impinging on a NACA 0012 airfoil. Our study includes water droplets with eight discrete sizes ranging from 1 to 160 microns. We vary the free-stream velocity of the incoming airflow in the range 60≤⁢𝑈≤⁢240 m s−1 and the chord length of the airfoil in the range 0.5≤⁢𝑐≤⁢2 m. Due to the dilute nature of supercooled clouds, one-way coupling is used in the simulations. The effects of droplet breakup and collision …

A Rigorous Framework For An Improved Messinger/Myers Model Of Ice Accretion Under Conditions Of Variable Property And Unsteady Aircraft Icing, Hashnayne Ahmed, Arash Shad, ‪Nadim Zgheib, S. A. Sherif, S. Balachandar

Mechanical Engineering Faculty Publications

We analyse the Messinger/Myers model by critically evaluating simplifying assumptions through a rigorous formulation of the rime ice accretion process. We explore the effects of both constant and variable ice density and thermal conductivity, along with the effects of sublimation from the ice surface. The effects of key factors such as droplet impact rate, ambient temperature relative to the freezing temperature and the temperature difference between the ambient air and the airfoil surface are examined. Under these varying conditions, the present rigorous formulation is used to assess the significance of unsteady effects, variable ice properties and sublimation. We observe that …

Survey Of Possible Magnetic Field Sources Around The Intragroup Medium Of Ngc 2563, Edward A. Wallace, Anna Williams

Macalester Journal of Physics and Astronomy

The origin and evolution of magnetic fields in space is an ongoing mystery in astronomy. Previous work has concluded the existence of magnetic fields in galaxy clusters, and to build an evolutionary model, the motivation behind this project is to determine how these magnetic fields form. In order to answer this question, we want to search for magnetic fields in galaxy group NGC 2563. To do this, our project determines the contribution to observed rotation measures of the galaxy group that come from the Milky Way and from the sources themselves.

Finding High Mass X-Ray Binaries In Ngc 3109, Caeden Miller, John (Jay) Gallagher Iii

Macalester Journal of Physics and Astronomy

High Mass X-Ray Binary systems can be difficult to find in the Milky Way due to high metallicity contributing to mass loss due to stellar wind, so we turn our attention to the galaxy NGC 3109 in order to find these systems. Using archival data from the Hubble Space Telescope using the Wide Field Camera 3, we do photometry in both the F475W and F814W filters for the two fields of view that cover the galaxy. We then plot these magnitudes on a color-magnitude diagram and use isochrones of 5 and 10 million years to gather minimum mass estimates of …

Electropolymerization Of Nile Blue And Toluidine Blue Dyes For Hydrogen Evolution Reaction Electrocatalysts, Camellia N. Schwartzman

Macalester Journal of Physics and Astronomy

This work investigated electropolymerized (EPD) organic conductive polymers poly-Nile Blue (PNB) and poly-Toluidine Blue (PTB) on fluorine-doped tin oxide (FTO) glass substrates as electrocatalysts for the hydrogen evolution reaction (HER). We investigated the effect of changing the heteroatoms in the pi-conjugated structure of poly-Neutral Red (PNR). UV-vis spectroscopy was used to estimate film thickness. Catalytic activity was quantified by Tafel slope and formal redox potential. PNB and PTB exhibited low current densities and small standard rate constants. Although neither showed highly active catalysts for HER, future directions should continue to pursue structures similar to PNR for HER electrocatalysts.

Examining Mulit-Wavelength Variability And Magnetic Interactions In The Polar St Lmi, Cain Rinkoski

Macalester Journal of Physics and Astronomy

Cataclysmic variable (CV) stars are interacting binary systems that exhibit exotic, multi-wavelength behavior driven by mass transfer from a donor star onto a white dwarf. As rich laboratories for accretion physics, binary dynamics, and the origins of Type Ia supernovae, CVs have been well studied in the X-ray, ultraviolet, optical, and infrared—but remain comparatively underexplored in the radio regime. This paper presents simultaneous, time-resolved optical and radio observations of the magnetic CV ST LMi, aimed at constraining its emission mechanisms and orbital modulation.
The optical light curves display brightness variations of approximately 1.31 ± 0.02 magnitudes on a period of …

A Thermal Control System For The Atlas Hgtd Module Construction Process, Keelin B. Murphy

Macalester Journal of Physics and Astronomy

In the aim of simplifying the production process of 2000 HGTD (High Granularity Timing Detector) modules at IJClab for the high luminosity phase of the ATLAS experiment at the CERN Large Hadron Collider, I designed, coded, and constructed an automatic temperature control system for module assembly and testing. To this end, I examined the module’s thermal response to changes in air temperature using a climate chamber and to various currents fed through a Peltier device situated under the module. I adapted the Peltier setup into a fully independent control system driven by an Arduino microcontroller running a PID feedback loop.

Dose Characterization Of Galactic Cosmic Rays In The Human Brain: A Phits-Based Study With A Segmented Anatomical Phantom, Shanice N. Manning

LSU Master's Theses

Astronauts aboard the International Space Station (ISS) are chronically exposed to a complex space radiation environment composed of galactic cosmic rays (GCR), solar particles, and Earth's trapped radiation. These high-energy particles interact with spacecraft shielding, producing secondary particles that can penetrate inside and deposit energy in sensitive tissues. Although animal studies have been useful in assessing space radiation risks, anatomical and physiological differences limit their applicability to human anatomy especially neuroanatomy. To address this gap, we developed a computational framework to model radiation dose distribution within the human brain using Monte Carlo simulations in Particle and Heavy Ion Transport code …

Theoretical And Experimental Investigation Of Liquid-Liquid Phase Separation: Characterizing Elastin-Like-Polypeptides, Adam D. Quintana

Chemical and Biological Engineering ETDs

This dissertation develops and validates a semi-empirical Flory–Huggins-based interaction model, combined with Cahn–Hilliard simulations, for predicting multi-component liquid–liquid phase separation (LLPS) in elastin-like polypeptide (ELP) systems. Equilibrium droplet compositions, measured using a PDMS-based microfluidic device, enabled direct parameterization of interaction coefficients. The model was applied to generate phase diagrams and assess composition dependence in ternary mixtures. Cahn–Hilliard simulations were conducted to explore potential phase morphologies under different interfacial conditions. Multi-component Lattice Boltzmann simulations were implemented to model droplet morphology evolution under varying interfacial and diffusive parameters, reproducing experimentally relevant morphologies. A three-phase wetting study revealed conditions for selective wetting and …

A Novel Chaotic Dna-Based Image Cryptosystem Leveraging Euclidean Division, Dynamic Josephus Traversal, And Reservoir Computing, Ahmed Kareem Shibeeb, Salah Albermany, Sadiq A. Mehdi

Karbala International Journal of Modern Science

This study presents a new chaotic DNA-based image cryptosystem that combines Euclidean division, dynamic Josephus traversal (DJT), and reservoir computing to address the weaknesses of current methods. Old chaotic DNA cryptosystems usually have problems such as using the same keys for different messages, simple DNA processes, and being vulnerable to attacks where the attacker can choose the input or try many options. The cryptosystem in this study uses a 7D hyperchaotic system that starts with keys created from SHA-512 hashes to produce changing keystreams based on the plaintext, making it very strong against such attacks. The proposed cryptosystem uses a …

Electroexcitation Of Nucleon Resonances And Emergence Of Hadron Mass, Patrick Achenbach, Daniel S. Carman, Ralf Gothe, Kyungseon Joo, Victor I. Mokeev, Craig D. Roberts

Faculty Publications

Developing an understanding of phenomena driven by the emergence of hadron mass (EHM) is one of the most challenging problems in the Standard Model. This discussion focuses on the impact of results on nucleon resonance (N*) electroexcitation amplitudes (or γ_vpN*) obtained from experiments during the 6 GeV era in Hall B at Jefferson Lab on understanding EHM. Analyzed using continuum Schwinger function methods (CSMs), these results have revealed new pathways for the elucidation of EHM. A good description of the Δ (1232) 3/2⁺, N (1440) 1/2⁺, and Δ (1600) 3/2^{+ …}

Investigating Long-Lasting Meteor Train Phenomena In Optical And Radio Regimes, Logan E. Cordonnier

Physics & Astronomy ETDs

Throughout history, meteors have been regarded as fascinating and portentous events, with bygone astronomers diligently recording their occurrence. The research presented herein continues in this tradition, using modern instruments, software, and data reduction techniques to study long-lasting meteor trail phenomena, specifically in the optical (persistent trains; PTs) and radio (meteor radio afterglows; MRAs) regimes. The overarching goal was to investigate the similarities between these phenomena, which began with the creation of a PT catalog. Many of the prior assumptions about the nature of PTs were found to be unsubstantiated, and several new behaviors were uncovered. This includes the discovery of …

Positive And Negative Parity States Of 226-236th Isotopes, Ali A. Mezban, Falih H. Al-Khudair

Karbala International Journal of Modern Science

The level scheme of the ^226-236Th nuclei is analyzed using the Interacting Boson Model (IBM-1). The ground state band (g. s.-band), beta band (β-band), gamma band (γ-band) have been described in the sd model space. To calculate the negative parity energy levels, the model space is extended to sdf by adding the f-boson (L=3). A sequence of states in energy bands up to 3.5 MeV has been obtained. The decay of negative states below 1 MeV built on an octupole vibration modes is investigated. The transition probabilities in-band and inter-band are calculated using the wave function of the …

A Modular Paradigm For The Directly Efficient Representation Of Kinetic Laser-Driven Plasmas, Roland D. Hesse

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

A natural inefficiency in conventional treatment of the plasma distribution arises from indiscriminate consideration of the contributions to field structure that are dynamically sourced from kinetic activity in disparate sectors of phase space. We introduce a range of techniques for model design to maximize representation efficiency without breaking key physical invariants indicative of physical reliability. An overview of varied adaptation to stable time-advance methods is given. Low-dimensional representation of a laser-driven plasma requires some creativity in differential structural modification, while direct efficiency is uncovered through the compression and rarefaction of a nonuniform momentum grid. These numerical models introduce embedded gains …

Advanced Study Of Nickel-Titanium Alloy: Effects Of Point Defects On Mechanical And Thermodynamic Properties, Diego Armando Juarez Rosales

Open Access Theses & Dissertations

High-throughput first-principles calculations of point defects are emerging as a powerful tool to accelerate materials discovery in applications [1]. Substitutional, antisite, and vacancy defects can play an important role in the mechanical and thermal properties of intermetallic alloys [2]. In this present work I compute the thermal and mechanical properties of shape-memory alloy nickel-titaniun (NiTi) in the B19â?? martensitic and B2 austenitic phases from molecular dynamics (MD), using a second nearest neighbor (2NN) modified embedded atom method (MEAM) [3] classical potential in the temperature range from 200K to 600K and composition range from 45 atomic percent to 55 atomic percent …

The Role Of Symmetries In Atomic, Electromagnetic, And Particle Physics, Joshua Martin O'Connor

Theses and Dissertations

Symmetries in atomic, electromagnetic, and weak interaction physics are explored to understand symmetry-breaking extensions of the Standard Model of particle physics. Lorentz-violating field theories are extremely interesting theoretically, since they possess many new features that are absent in Lorentz-invariant models. We outline the formalism and experimental status of the Lorentz- and CPT-violating Standard Model Extension, in both the classical and quantum regimes. Processes such as vacuum Cerenkov radiation, which are kinematically forbidden when Lorentz symmetry is exact may become allowed when this symmetry is weakly broken. Particle decays, such as pion and kaon decays, although allowed in Lorentz-invariant theories, are …

Unraveling Nonperturbative Qcd With Transverse Momentum Hadronic Structures, Tommaso Rainaldi

Physics Theses & Dissertations

The main purpose of this thesis is to investigate the theoretical foundations of the factorization theorems that involve transverse quark and gluon momentum distributions, and to better understand the interface between foundational questions and phenomenological applications. Many of these applications involve using transverse parton momentum dependent (TMD) correlation functions as tools for probing the complex nonperturbative structures of the hadrons.

We first introduce the concepts of collinear and TMD factorization in a toy-model theory and, by leveraging the comparative simplicity of such a model, we test the range of validity and limitations of the factorization approach. At the same time, …

Analysis Of Students' Creative Thinking Skills In Learning Hydrocarbons By Using Daily Life-Based Practicum Method, Yenni Kurniawati, Laras Dyaz Handayani, Dea Ramadani, Nurhikmah Sari

Jurnal Pendidikan Sains

Creative thinking skill is a competence of the 21st century that is needed very much and needs to be increased by utilizing chemistry in life. This research aimed at analyzing student creative thinking skills in experimental and control groups and finding out the effect of the daily life-based practical work learning method on student creative thinking skills. This research was conducted in the eleventh grade at High School 1 Pekanbaru on the hydrocarbon lesson. The quasi-experimental method was used in this research with pretest-posttest and non-equivalent control group designs. The instruments used in this research were essay tests, observation, and …

Digital Comic Learning Media (E-Comic) To Increase Student Learning Interest In Reaction Rate Material At High School, Berliana Afsohin Nabila, Achmad Lutfi

Jurnal Pendidikan Sains

This study aims to develop digital comic learning media that is effective in increasing students' interest in learning about reaction rate material, focusing on the media's validity, practicality, and overall effectiveness. This research utilizes the research and development method with the ADDIE model. Research instruments were used, including validity sheets to assess the media's validity, student activity observations, and student response questionnaires to evaluate the media's practicality, as well as student interest questionnaires and learning outcomes to measure the effectiveness of the learning media. The findings show that validity results showed a mode score of 4, indicating a very valid …

Contextual Approach To Improve Problem Solving Skills In Ipas Subject At Elementary School: A Study Development Of Teaching Materials, Nur Hidayah, Sumarno Sumarno, Joko Siswanto

Jurnal Pendidikan Sains

The objective of this study is to assess the validity, practicality, and efficacy of instructional materials. We refer to this research as research and development, with a focus on the creation of teaching materials. The research design proposed by Borg and Gall consists of six steps: identification of potential and difficulties, data collecting, product design, design validation, design revision, and product trial. The utilized instruments comprise expert and practitioner validity sheets, teacher and student response surveys, and validation sheets for teaching materials and modules, as well as pretest and posttest questions. Experts performed the validity assessment, attaining a score of …

Analysis Of Misconceptions In Learning Biology Mutation Material At High School, Fitri Hayati Kurnia, Tri Wahyu Agustina, Wahyuni Handayani

Jurnal Pendidikan Sains

This research aims to analyze student misconceptions regarding mutation material in class XII. The research method uses a descriptive approach with mixed methods, which combines qualitative and quantitative methods. Qualitative data was obtained through interviews with biology teachers, while quantitative data was obtained through questionnaires and essay tests on students. The research results indicate that the material that students like is growth and development, while the material they don't like is gene mutation and genetic material. Students' misconceptions occur due to preconception aspects, associative thinking, and a lack of understanding of genetic concepts. It was found that students' understanding of …

A Promising Statistical Approach For Studying The Collisional Excitation Induced By Co: Application To The Cs-Co System, Amélie Godard Palluet, Richard Dawes, Ernesto Quintas-Sánchez, Adrian Batista-Planas, François Lique

Chemistry Faculty Research & Creative Works

The calculations of rate coefficients for the interpretation of molecular spectra are a recognized computationally expensive task. This is particularly true for media like comets, where the dominant species (CO, CO₂, and H₂O) have relatively high masses. Currently, no clear methodology exists to treat the collisional excitation of heavy species at low temperatures, thus limiting the number of collisional studies on such species. We present here a promising statistical approach to determine collisional rate coefficients of heavy systems as an alternative to fully quantum calculations when heavy projectiles such as CO are considered. This is illustrated …

Variational Monte Carlo Optimization Of Proton-Proton Scattering Potential Using The Phase Function Method, Shikha Awasthi, Anil Khachi, O.S.K.S. Sastri

Turkish Journal of Physics

The Riccati-type nonlinear differential equation, also known as the Phase Function equation, is used to construct local inverse potentials for the 1S0 - pp state by bypassing the well-known Schrödinger equation. The pp interaction is described using the Malfliet-Tjon potential model for the nuclear component combined with a screened Coulomb potential, with the phase equation solved via the fourth-order Runge-Kutta (RK-4) method. Based on our analysis, we confirm that the optimized interaction potential closely matches the well-known realistic Argonne V18 and Reid potentials for the 1S0 state, and the computed phase shifts and cross-sections show excellent agreement with experimental data. …

Evolution Of Wormholes Under F(R, T) Theory, The Karmarkar Condition And The Casimir Energy, Murat Metehan Türkoğlu

Turkish Journal of Physics

In this study, both the evolution of wormholes (by examining both the energy conditions and using the TOV equations) and the effects of the Karmarkar condition on the solutions obtained under certain specific cases were examined in the light of the f(R, T) gravity theory, using two f(R, T) functions predicted to describe the accelerated expansion of the universe. In this context, for the first time in the literature, a generalized shape function was obtained using the Karmarkar condition. It was observed that solutions of the type R -a12/R+a2g(T) satisfy the energy conditions (with the dominant energy condition being partially …

Physical And Chemical Characterization Of Recycled Glass Sand For Environmental Restoration, Shehbaz Ahmad, Julie P. Vanegas, Nicholas Borne, Natalia Butler, Toby Mendels, Leah A. Michaeloff, Diego Molina, Mary Salvaggio, Samantha Tamayo, Franziska Trautmann

Physics & Astronomy Faculty Publications

Introduction

We rely on coastal resources for food, water, and energy. However, over 75% of U.S. coastlines are eroding. Concurrently, the U.S. recycles less glass than other developed countries, landfilling hundreds of millions of tons every year. Recycled glass sand has many potential benefits over natural sand for combatting land loss; for example, it can be produced with controlled particle size to better resist erosion, making it an excellent—and underutilized—material for environmental restoration.

Objectives

This research compares the physical and chemical properties of recycled glass sand to natural sands (beach and dredge) from the U.S. Gulf Coast to assess environmental …

A Contextual Analysis Of The Early Work Of Andrzej Trautman And Ivor Robinson On Equations Of Motion And Gravitational Radiation, Donald Salisbury, Daniel Kennefick

Physics Faculty Publications and Presentations

In the mid-1950s, Andrzej Trautman published a series of papers connected with his dissertation work written under Leopold Infeld. In these, he drew upon the slow motion approximation developed by Infeld, the general covariance-based strong conservation laws enunciated by Bergmann and Goldberg, the Riemann tensor attributes explored by Goldberg and related geodesic deviation exploited by Pirani, the permissible metric discontinuities identified by Lichnerowicz, O'Brien and Synge, and finally Petrov's classification of vacuum spacetimes. With several significant additions he produced a comprehensive overview of the state of research in equations of motion and gravitational waves that was presented in a widely …

Exploring The Very Early Cosmological History With Dark Matter And Primordial Black Holes, Phuc Duc Loc Ngo

Physics & Astronomy ETDs

We explore the possibilities of nonstandard early cosmological histories and their potential roles to explain DM. We study how particle DM is produced with scenarios of early matter domination (EMD), how primordial black holes (PBHs), which could also be a DM candidate in certain mass ranges, are formed with enhanced curvature perturbation or FOPT and the corresponding gravitational wave (GW) signals, how PBHs could increase their mass by accretion during EMD and the corresponding GW signals.

Uncovering Multiscale Structure-Property Correlations Via Active Learning In Scanning Tunneling Microscopy, Ganesh Narasimha, Deja Kong, Paras Regmi, Rongying Jin, Zheng Gai, Rama Vasudevan, Maxim Ziatdinov

Faculty Publications

Atomic arrangements and local sub-structures fundamentally influence emergent material functionalities. These structures are conventionally probed using spatially resolved studies and the property correlations are deciphered by a researcher based on sequential explorations, thereby limiting the efficiency and scope. Here we demonstrate a multi-scale Bayesian deep-learning based framework that automatically correlates material structure with its electronic properties using scanning tunneling microscopy (STM) measurements in real-time. Its predictions are used to autonomously direct exploration toward regions of the sample that optimize a given material property. This method is deployed on a low-temperature ultra-high vacuum STM to understand the structure-property relationship in a …