Physics Commons^™

Detection Of Oil Pollution On The Tigris River In Iraq Using Fluorescence And Reflecting Techniques, Ahmad K. Ahmad, Thamer M. Mohammed

Karbala International Journal of Modern Science

In this study, a broadband light source (visible and ultraviolet) was used to name minerals via fluorescence spectra and estimate slick oil thickness, ranging from sub-millimetres, using the reflecting spectrum technique. Using a fluorescent technique, we obtained fluorescence spectra of the samples, converting and processing the signals to produce high-resolution data, which enabled the identification of the types of dissolved elements and oil slicks in the Tigris River, highlighting pollution sources and potential control measures. This system aims to show the faint signal in fluorescence samples collected from the cooling system outlet water throughout the refining process from AL-Dora (Baghdad) …

Magnetic Reconnection In Space: From Two-Dimensional Magnetohydrodynamic (Mhd) Simulations To Three-Dimensional Particle-In-Cell (Pic) Simulations, Shan-Chang Lin

Dartmouth College Ph.D Dissertations

Magnetic reconnection is a physical process in plasmas that converts magnetic energy into plasma kinetic energy and thermal energy. It plays an important role in the generation of solar flares, interactions between the solar wind and Earth's magnetosphere, and magnetic confinement fusion devices. This thesis focuses on studying magnetic reconnection using computational methods, including two-dimensional (2D) magnetohydrodynamics (MHD) simulations to study Petschek-type reconnection, estimating the timescale from a thin current sheet to fully developed reconnection using 2D particle-in-cell (PIC) simulations, and magnetic reconnection X-line spreading in the current direction using three-dimensional (3D) PIC simulations.

This thesis contributes to the understanding …

Antibacterial Potential Of Tapanuli Orangutan (Pongo Tapanuliensis) Food In Batang Toru Forest Against Escherichia Coli And Salmonella Typhi, Herna Febrianty Sianipar, Wahyu Widoretno, Luchman Hakim, Rezi Rahmi Amolia, Fatchiyah Fatchiyah

Karbala International Journal of Modern Science

Diarrhea is a common disease affecting orangutans, primarily caused by Escherichia coli and Salmonella typhi bacteria. To treat this disease, antibacterial food sources are essential as therapeutic agents for orangutans. The fruits consumed by Tapanuli orangutans include Campnosperma auriculatum, Agathis borneensis, Artocarpus heterophyllus, Castanopsis argantea, and Aglaia tomentosa. This study aims to examine the amino acid and phytochemical components with potential antibacterial properties in these five fruit species and their inhibitory effects on E. coli and S. typhi growth through cell lysis, observed using a Scanning Electron Microscope (SEM). The samples were tested for amino acids, phytochemicals, vitamin C content, …

Effects Of Plasma-Activated Water On Wheat: Germination And Seedling Development, Wafaa Abdulrazzaq Abdullah, Hadeel O. Ismael, Duaa A. Uamran, Hammad R. Humud

Karbala International Journal of Modern Science

The food sector must contend with issues such as pathogen resistance to some of the available chemical agents, environmental pollution, and climate change to provide healthy food for livestock and people. The application of atmospheric pressure plasma jets (APPJs) is one potential solution for such problems. Plasma is appropriate for effective surface decontamination regarding food products and seeds, surface decontamination, and achieving improved agricultural production yields. The impact of plasma-activated water (PAW) produced by plasma jet discharge (PJD) system on in vitro-cultivated wheat seeds is examined in this work. For this aim, a plasma jet system was constructed with a …

Thermally Tunable Mid-Infrared Nanocavity Resonance Of Coupled Surface Plasmon-Phonon Polaritons, Satya R. Kachiraju, Zachary M. Brown, Sundar Kunwar, Long Chang, Imtiaz Ahmad, Pinku Roy, Vladimir Kuryatkov, Yejin Kwon, Ayrton A. Bernussi, Chase T. Ellis

Physics & Astronomy Faculty Publications

Phase-change materials (PCMs) are essential for achieving tunability of metasurfaces. However, they frequently face limitations in the long-wave infrared range because of their lossy behavior. Here, we experimentally demonstrate a thermally tunable mid-infrared nanocavity resonance from coupled surface plasmon-phonon polaritons that are supported within a trilayer structure of metal-PCM layer-polar dielectric (Au-VO2-SiC). The top metal structures configure the Fabry-Perot cavity resonance near 840 cm−1 (11.9 µm), which is sensitively tunable and reversible with small changes in the VO2 refractive index ∆n near below its insulator-to-metal phase transition temperature where the loss is small. The maximum resonance shift of 7.7 cm−1 …

A Molecular Dynamics Study Of Single Crystal And Intergranular Crack Growth Behavior In WX M1−X Binary Aloys (M = V, Mo, Ta, Re), Samuel C. Wagers, Adib J. Samin

Faculty Publications

This study employs molecular dynamics simulations to investigate the fracture behavior of four binary refractory alloys W_xM_1−x (M = V, Mo, Ta, Re) and their dependence on crystallographic orientation, composition, and grain boundary (GB) structure, focusing on six distinct low-sigma grain boundaries. The simulations reveal that the effect of composition is complex with the most pronounced effect, accompanied by the maximum or minimum stress intensity factor, generally occurring at intermediate compositions. All compositions showed a higher fracture resistance in the [110] orientation compared to the [100] orientation. There was a strong thermodynamic tendency for Mo and V, …

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 …

Evaluation Of The Energy And Timing Resolution Of Cerium Bromide Detectors For Nuclear Applications, Madyson C. Hickman

Physics and Astronomy Summer Fellows

We tested the timing and energy resolution of cerium bromide (CeBr₃) detectors for use in the CeBrA array of gamma-ray detectors in the John D. Fox lab at Florida State University. Using different sources, we calibrated energy spectra and analyzed FWHM values to determine the energy resolution. Timing resolution from a ⁶⁰Co source was measured using coincident gamma rays from the sources. Our results showed the expected energy dependence and confirmed that the detectors meet performance standards.

Cerium Bromide Detectors: Measuring Efficiencies For Gamma Ray Detection, Ewan Chattin

Physics and Astronomy Summer Fellows

This Summer we have had access to 9 Cerium Bromide Gamma Ray detectors, which we have conducted various tests on to ensure a smooth transition when they are integrated into the Cerium Bromide Array(CeBrA) at Florida State University. One of the goals we pursued was mapping out the Full Energy Peak Efficiency for each of the detectors, which is described below. While the results we have right now are not our final ones, we can describe the trends that we see in the detectors accurately. This work is supported by National Science Foundation Grant No. 2405485.

Quantum Memory, Isabel Martinez-Robles

Physics and Astronomy Summer Fellows

Isolated quantum systems are almost always observed to achieve thermal equilibrium in experiments. Understanding cases where they do not thermalize, and therefore retain memory about the initial state, could lead to the development of a quantum memory. We excite atoms in a magneto-optical trap, where they are cold enough to treat as stationary. In our experiment, our atoms exchange energy via dipole-dipole interactions and fail to thermalize. We present a theoretical and computational analysis that suggests that our system starts in an exceptional initial state.

Numerical Simulation Of Frost Formation And Heat Transfer On Fin-And-Tube Heat Exchangers In Turbulent Cross-Flow, Mahsan Farzaneh, ‪Nadim Zgheib, S. Balachandar, S. A. Sherif

Mechanical Engineering Faculty Publications

Frost formation in fin-and-tube heat exchangers in turbulent cross-flow presents significant challenges in industrial refrigeration applications, affecting heat transfer efficiency and operational reliability. The purpose of this work is to investigate frost deposition and growth on a staggered bank of a fin-and-tube freezer coil under turbulent forced convection conditions. The focus here is on investigating conditions that closely replicate real-world scenarios in large walk-in industrial freezers. Using a direct numerical simulation approach, we examine the flow dynamics and thermal behaviour in the presence of frost, considering turbulent regimes characterized by a Reynolds number in the range 1050≤𝑅⁢𝑒𝐷,avg≤4800, with the characteristic …

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 …

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 …

Synthesis Of Cancrinite Zeolite From Toraja Natural Bentonite For Heavy Metal Removal From Wastewater, Yuli Astuti, Paulina Taba, Siti Fauziah, Syarifuddin Liong, Yusafir Hala, Nur Umriani Permatasari, Satria Putra Jaya Negara, Fadliah Fadliah

Karbala International Journal of Modern Science

This study explores the production of cancrinite (CAN) zeolite from bentonite found in Toraja (a place in South Sulawesi Province, Indonesia) and its effectiveness in removing Pb²⁺ and Fe³⁺ ions from wastewater. The synthesis was carried out using a hydrothermal method with varying NaOH concentrations, where a single phase of zeolite was formed at 5 M, as confirmed through XRD analysis. FTIR results showed the characteristics of CAN zeolite with typical absorption peaks at 676, 622, and 565 cm^-1, as well as the presence of carbonate groups (CO₃^2-) at 1300-1400 cm^-1. SEM …

Machine Learning Crime Prediction Models And The Gap Between Research And Implementation: A Systematic Review, Ricardo Huamantingo, Miguel Cano-Lengua, Ciro Rodriguez

Karbala International Journal of Modern Science

A crime is an illegal or violent act committed by one individual against another. The increasing crime rate has become a major concern as it negatively affects people's quality of life and generates significant social and economic costs. This study aims to identify the most widely used machine learning (ML) models for crime prediction, determine evaluation metrics for assessing model performance, and analyze key data characteristics to enhance real-world implementation. The study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. A search string was formulated using the population, intervention, comparison, and outcomes (PICO) framework and applied …

Psilostachyin B As Potential Immune Checkpoint Inhibitor Targeting Ctla-4 And Pd-L1 In The Development Of Cancer Immunotherapy: A Computational Investigation, Moh Dliyauddin, Nabila Shafa Yumna Salsabila, Noviana Dwi Lestari, Sapti Puspitarini, Mansur Ibrahim, Sri Rahayu, Muhammad Sasmito Djati, Muhaimin Rifa’I

Karbala International Journal of Modern Science

Immunotherapy is a promising treatment approach by targeting immune checkpoints such as CTLA-4 and PD-L1 to overcome cancer progression. The utilization of Curcuma longa and Phyllanthus niruri as potential immune checkpoint inhibitors offers an alternative cancer therapy. Computational analyses including molecular docking and molecular dynamics with validation using Molecular Mechanics/Poisson-Boltzmann Surface Area (MM-PBSA), Dynamic Cross-Correlation Matrix (DCCM), and Principal Component Analysis (PCA), were performed in this study. Results show that Psilostachyin B is the most promising inhibitor candidate against CTLA-4 and PD-L1, with binding affinity values of -6.9 and -6.8 kcal/mol, respectively. Molecular dynamics simulation results indicated that Psilostachyin B …

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.

Modelling Of The Overcontact Eclipsing Binary V826 Aur, Kalev T. Murray-Rouse, John M. Cannon, Anna Williams, Wes Tobin

Macalester Journal of Physics and Astronomy

We present a model of the eclipsing binary system V826 Aur using differential photometric data from the Robert L. Mutel Telescope (RLMT) at the Winer Observatory in Sonoita, Arizona. The calculated time of superconjunction was found to be 60648.7658534 and the period was 0.361701 d. These values were used to generate a best-fit model of the eclipsing binary with the PHOEBE program. The best-fit modelled parameters were found to be: mass ratio (𝑞) is equal to 2.769, the inclination (𝑖) is equal to 80.45◦, the fillout factor (𝑓) equals 0.0961, and the temperature ratio (𝑇2∕𝑇1) is 0.9740. Although not statistically …

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 …

Electro-Optic Detection Of Plasma Generated Thz Pulses, Rohan Lichtenberg, James Heyman

Macalester Journal of Physics and Astronomy

We implement a technique of generating ultrafast THz-pulses for use in a time-resolved THz-spectroscopy system. We focus light emitted by an amplified Ti:Sapphire Laser in order to ionize a small filament of air, causing the formation of plasma. When laser pulses cross the plasma the Kerr effect produces measurable, ultrafast THz pulses. More specifically, we characterized pulse length and spectral bandwidth of the generated THz-pulses by examining the response by different electro-optical crystals of different thicknesses. This THz spectroscopy system is currently being used to measure the mobilities of photoelectrons in Methylammonium Lead Iodide perovskite materials, which are potential substitutes …

Making And Breaking Chaos: Analog Computer Implementation Of The Lorenz Model, Reed Lefevre, James Doyle

Macalester Journal of Physics and Astronomy

Hybrid analogue-digital computers have been shown to have certain advantages over traditional digital computers when solving nonlinear partial differential equations. Motivated by this fact, we implement the Lorenz equations on an analogue electronic computer and vary the parameters to analyze the bifurcations. With the working circuit, we compared experimental results to various digital simulations to assess the effectiveness of our circuit. We find clear qualitative agreement between the physical circuit and digital simulations; however, we observe a noticeable quantitative difference in behavior. The circuit depicts a picturesque Lorenz Butterfly plot and bifurcates into fixed points and chaos; however, these bifurcations …

Non-Destructive Compositional Analysis Of Lead Halide Perovskite Films Using Thz Spectroscopy And A Three-Oscillator Dielectric Model, Isaac J.C Kisker

Macalester Journal of Physics and Astronomy

Terahertz (THz) Spectroscopy offers a novel approach to probing low-energy phonon excitation in complex crystalline materials like methylammonium lead iodide (MAPI) perovskite films. In this research, we use time-resolved Terahertz Spectroscopy in tandem with a three-oscillator model to non-destructively ascertain the relative volumetric composition of MAPI and residual lead iodide (PbI₂) in spin-coated films. The dielectric function is modeled as a product over longitudinal and transverse optical phonon modes. This model is then fitted to the measured THz spectra, allowing us to extract the contributions from both MAPI and PbI₂.

Monitoring The Degradation Of Methylammonium Lead Iodide Perovskite Thin Films By Uv Exposure, Addison Dau, Ethan Dale, James Heyman

Macalester Journal of Physics and Astronomy

This project involved lead-halide perovskite thin films, a promising novel solar cell material. The goal was to monitor the composition of the samples during degradation from blue light exposure using vibrational spectroscopy. IR and THz spectroscopy measured the composition of the samples in-situ between periods of blue light exposure, probing the N-H and Pb-I vibrational modes. Plotting MA and MAPI concentrations versus blue light exposure showed that the MA and MAPI concentrations initially decreased in a gradual linear fashion until a threshold photon flux where both vibrational absorption bands simultaneously collapsed. This suggests that there is a discontinuous change in …

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 …

Role Of Staphylococcus Aureus And Streptococcus Pyogenes Biofilms On The Alternation Of Cellular Immunity In Pediat-Ric Tonsillitis Patients, Shayma Ali Hussein, Taban Kamal Rasheed

Karbala International Journal of Modern Science

This study examines the effect of Staphylococcus aureus and Streptococcus pyogenes biofilms on cellular hematological parameters and distribution and phenotyping of cellular immunity in mucosal tissue of tonsils. Thirty healthy controls and fifty pediatric tonsillitis patients participated in the research. Thirty isolated S. aureus and S. pyogenes were tested for biofilm-forming capability (BFC). Hematological parameters were assessed before tonsillectomy, and 9 tonsil samples were evaluated using hematoxylin and eosin stain to investigate the histopathological alterations. Immunohistochemistry (IHC) staining was carried out for detecting dendritic cells (CD1a), neutrophils (CD15), macrophages (CD68), helper T cells (CD4), and cytotoxic T cells (CD8). Hematological …