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A Review On Antibacterial Activity Of Nanoparticles, Badr-Edine Sadoq, Mohammed Reda Britel, Adel Bouajaj, Ramzi Maâlej, Ahmed Touhami, Marwa Abid, Hanen Douiri, Fakhita Touhami, Amal Maurady 2023 The University of Texas Rio Grande Valley

A Review On Antibacterial Activity Of Nanoparticles, Badr-Edine Sadoq, Mohammed Reda Britel, Adel Bouajaj, Ramzi Maâlej, Ahmed Touhami, Marwa Abid, Hanen Douiri, Fakhita Touhami, Amal Maurady

Physics and Astronomy Faculty Publications and Presentations

The increasing resistance of bacteria to antibiotic agents is a main global public health problem. The use of nanoparticles is one of the promising ways to overcome microbial resistance to antimicrobial agents. Metal nanoparticles are increasingly used to target bacterial strains. Advances in nanotechnology, in particular the ability to synthesize nanoparticles of specific size and shape, are likely to lead to the development of new antibacterial agents. The antibacterial activities of nanoparticles are largely influenced by their sizes and large surface area/mass ratio. The antibacterial mechanisms of nanoparticles are poorly understood, but the currently accepted mechanisms include oxidative stress induction, …


Spectral Broadening Effects On Pulsed-Source Digital Holography, Steven A. Owens, Mark F. Spencer, Glen P. Perram 2023 Air Force Institute of Technology

Spectral Broadening Effects On Pulsed-Source Digital Holography, Steven A. Owens, Mark F. Spencer, Glen P. Perram

Faculty Publications

Using a pulsed configuration, a digital-holographic system is setup in the off-axis image plane recording geometry, and spectral broadening via pseudo-random bit sequence is used to degrade the temporal coherence of the master-oscillator laser. The associated effects on the signal-to-noise ratio are then measured in terms of the ambiguity and coherence efficiencies. It is found that the ambiguity efficiency, which is a function of signal-reference pulse overlap, is not affected by the effects of spectral broadening. The coherence efficiency, on the other hand, is affected. As a result, the coherence efficiency, which is a function of effective fringe visibility, is …


The Influence Of Allostery Governing The Changes In Protein Dynamics Upon Substitution, Joseph Hess 2023 Clemson University

The Influence Of Allostery Governing The Changes In Protein Dynamics Upon Substitution, Joseph Hess

All Dissertations

The focus of this research is to investigate the effects of allostery on the function/activity of an enzyme, human immunodeficiency virus type 1 (HIV-1) protease, using well-defined statistical analyses of the dynamic changes of the protein and variants with unique single point substitutions 1. The experimental data1 evaluated here only characterized HIV-1 protease with one of its potential target substrates. Probing the dynamic interactions of the residues of an enzyme and its variants can offer insight of the developmental importance for allosteric signaling and their connection to a protein’s function. The realignment of the secondary structure elements can …


Signatures Of Black Holes, Alexandra B. Chanson 2023 Utah State University

Signatures Of Black Holes, Alexandra B. Chanson

All Graduate Theses and Dissertations

In this defense I will describes three approaches to learn more about the relationship between the dynamics of black-holes and the distinctive signatures of a black hole systems: infinitesimal changes in the black hole background producing field excitations relating new fundamental black hole thermodynamic relations, mechanisms powering relativistic black hole jets and spontaneous symmetry breaking in five space-time dimensions, and physical signatures of black hole event horizons as conformal field theory duals (in both d=4,5 dimensional axisymmetric spacetimes).


The Derivation Of Sodium Density In The Mesosphere And Lower Thermosphere From The Na Lidar Photon Counting Profiles, Xiaoqi Xi 2023 Utah State University

The Derivation Of Sodium Density In The Mesosphere And Lower Thermosphere From The Na Lidar Photon Counting Profiles, Xiaoqi Xi

All Graduate Theses and Dissertations

Derivation of Sodium (Na) number density from the Na lidar observations requires the in situ temperature and wind information because the absorption cross-section of the Na atom is a function of these dynamic parameters. The Na number density above ~ 110 km altitude was difficult to derive with the conventional algorithm, however. The standard output of the Na number density that utilizes the lidar-measured wind and temperature information falls short at ~ 110 km altitude and above due to the relatively large measurement uncertainties in the two critical parameters (low signal-to-noise ratio). Therefore, an innovative algorithm that may drive the …


The Time-Dependent Ionospheric Model Using A Tec-Driven Servo: An Investigation Of The Capabilities And Limitations, Jenny Rebecca Whiteley 2023 Utah State University

The Time-Dependent Ionospheric Model Using A Tec-Driven Servo: An Investigation Of The Capabilities And Limitations, Jenny Rebecca Whiteley

All Graduate Theses and Dissertations

The ionosphere is a region of the atmosphere with a high density of electrons. These electrons affect the behavior of any electromagnetic wave that passes through the ionosphere. Communication and geolocation systems, such as traditional radio and Global Positioning Systems, depend on emitted electromagnetic signals being picked up by a receiver. The presence of the ionosphere affects the behavior of the signal and the quality of the service. Hence, the interactions between electromagnetic waves and the ionosphere provide a major motivation to understand, research, and successfully model and predict the ionosphere and its physical phenomena. This study focused on determining …


Self-Calibrating Optical Galaxy Cluster Selection Bias Using Cluster, Galaxy, And Shear Cross-Correlations, Chenxiao Zeng, Andrés N. Salcedo, Hao-Yi Wu, Christopher M. Hirata 2023 Ohio State University

Self-Calibrating Optical Galaxy Cluster Selection Bias Using Cluster, Galaxy, And Shear Cross-Correlations, Chenxiao Zeng, Andrés N. Salcedo, Hao-Yi Wu, Christopher M. Hirata

Physics Faculty Publications and Presentations

The clustering signals of galaxy clusters are powerful tools for self-calibrating the mass–observable relation and are complementary to cluster abundance and lensing. In this work, we explore the possibility of combining three correlation functions – cluster lensing, the cluster–galaxy cross-correlation function, and the galaxy autocorrelation function – to self-calibrate optical cluster selection bias, the boosted clustering and lensing signals in a richness-selected sample mainly caused by projection effects. We develop mock catalogues of redMaGiC-like galaxies and redMaPPer-like clusters by applying halo occupation distribution models to N-body simulations and using counts-in-cylinders around massive haloes as a richness proxy. In addition …


Modelling Galaxy Cluster Triaxiality In Stacked Cluster Weak Lensing Analyses, Hao-Yi Wu 2023 Boise State University

Modelling Galaxy Cluster Triaxiality In Stacked Cluster Weak Lensing Analyses, Hao-Yi Wu

Physics Faculty Publications and Presentations

Counts of galaxy clusters offer a high-precision probe of cosmology, but control of systematic errors will determine the accuracy of this measurement. Using Buzzard simulations, we quantify one such systematic, the triaxiality distribution of clusters identified with the redMaPPer optical cluster finding algorithm, which was used in the Dark Energy Survey Year-1 (DES Y1) cluster cosmology analysis. We test whether redMaPPer selection biases the clusters’ shape and orientation and find that it only biases orientation, preferentially selecting clusters with their major axes oriented along the line of sight. Modelling the richness–mass relation as log-linear, we find that the log-richness amplitude …


Enhanced Quantum Chemistry With Machine Learning, Brock Dyer 2023 Ursinus College

Enhanced Quantum Chemistry With Machine Learning, Brock Dyer

Physics and Astronomy Summer Fellows

This file is a catalogue of the relevant quantum mechanical and computer programming topics that I learned during the summer which will be helping me to generate an artificial intelligence that will be able to perform computational chemical calculations at a much faster rate and comparable or better accuracy than current methods.


Improving The Efficiency Of Liquid-Hydrogen Simulation Via Event Storage, Jake Kosa 2023 Ursinus College

Improving The Efficiency Of Liquid-Hydrogen Simulation Via Event Storage, Jake Kosa

Physics and Astronomy Summer Fellows

We contributed to the analysis of gamma-ray spectroscopy data collected at the Facility for Rare Isotope Beams at Michigan State University by speeding up the UCGretina simulation code, used in the analysis and planning of experiments. Simulating beam-target interactions in a liquid-hydrogen target system is a time intensive task, even when parallelized. In the process of analyzing data, a large number of simulations must be run for different gamma-ray energies, target positions, and lifetimes of excited states. We are addressing the most computationally intensive component of the simulations by adding the ability to simulate a large sample of beam particles …


A Method For Calculating Lateral Surface Area Of Bistatic Radar Beam Overlap, James I. Murray, Fredrick A. Jenet 2023 The University of Texas Rio Grande Valley

A Method For Calculating Lateral Surface Area Of Bistatic Radar Beam Overlap, James I. Murray, Fredrick A. Jenet

Physics and Astronomy Faculty Publications and Presentations

It has been shown that bistatic radars using radio telescopes as receivers can be used to increase the sensitivity of orbital debris measurements over traditional terrestrial monostatic radar. A method to calculate the lateral surface area of a bistatic radar is needed to evaluate the efficacy of a proposed bistatic radar configuration for orbital debris measurements. For over three decades, models of the orbital debris (OD) environment in low Earth orbit (LEO) have been developed to assess the risk posed by OD to spacecraft. While terrestrial radar measures debris 3 mm and larger and in situ measurements provide data for …


Enhanced Acousto-Optic Properties Of Silicon Carbide Based Layered Structure, Namrata Dewan Soni 2023 Department of Physics, Hansraj College, University of Delhi, Delhi, India

Enhanced Acousto-Optic Properties Of Silicon Carbide Based Layered Structure, Namrata Dewan Soni

Al-Bahir Journal for Engineering and Pure Sciences

This study investigates the feasibility of using silicon carbide-based layered surface acoustic wave (SAW) devices in acousto-optic applications. The acousto-optic properties of the temperature-stable layered structure TeO3/SiC/128oY-X LiNbO3 are investigated through theoretical analysis. This analysis includes the evaluation of key parameters such as the overlap integral, figure of merit, and diffraction efficiency. The SAW propagation characteristics and field profiles required for these calculations are obtained using SAW software. Results show that the layered structure has high diffraction efficiency of nearly 96% and a promising value for the acousto-optic figure of merit, indicating potential use in low driving power acousto-optic devices. …


Entanglement In The Hawking Effect: From Astrophysical To Optical Black Holes, Dimitrios Kranas 2023 Louisiana State University at Baton Rouge

Entanglement In The Hawking Effect: From Astrophysical To Optical Black Holes, Dimitrios Kranas

LSU Doctoral Dissertations

The Hawking effect is an exciting physical prediction lying at the intersection of the two most successful theories of the past century, namely, Einstein’s theory of relativity and quantum mechanics. In this dissertation, we put special emphasis on the quantum aspects of the Hawking process encoded in the entanglement shared by the emitted fluxes of created quanta. In particular, we employ sharp tools from quantum information theory to quantify the entanglement produced by the Hawking effect throughout the black hole evaporation process. Our framework allows us to extend previous calculations of entanglement to a larger set of cases, for instance, …


Application Of A Diatomic Molecule Model Potential To A Series Of Homo- And Heterodiatomic Molecules, Dorien E. Carpenter, Javier E. Hasbun 2023 University of West Georgia

Application Of A Diatomic Molecule Model Potential To A Series Of Homo- And Heterodiatomic Molecules, Dorien E. Carpenter, Javier E. Hasbun

Georgia Journal of Science

We apply a one-dimensional classical model of a diatomic molecule model potential with modifications to H2, HF, LiF, N2, and CO. We obtain the unknown parameters of this model by digitizing plots of the potential curves for the molecules from a published, Hartree-Fock based theoretical electron correlation calculation (Piris 2017). We then apply the method of successive approximations to the model in order to calculate the wavenumber for each molecule in the series. The wavenumber depends on a parameter which in turn depends on the initial conditions. The value of this parameter for each individual molecule …


Size Effect On The Optical Response Of Cylindrical Palladium Nanoparticles, Salem Marhaba, Mohammed Khalaf 2023 Department of Physics, Faculty of Science, Beirut Arab University, Lebanon

Size Effect On The Optical Response Of Cylindrical Palladium Nanoparticles, Salem Marhaba, Mohammed Khalaf

BAU Journal - Science and Technology

In this work, a computational study is carried out to investigate the optical response of palladium nano-cylinders. The Finite Element Method (FEM) is employed using the COMSOL MULTIPHYSICS simulation program to calculate the scattering, absorption, and extinction cross-sections. The influence of the size of the cylindrical nanoparticles on their optical properties is discussed. The results are plotted for a broad spectral range of wavelengths from ultra-violet to infra-red of the incident electromagnetic wave on the cylindrical nanoparticles.


Adaptive Plasmonic Metasurfaces For Radiative Cooling And Passive Thermoregulation, Azadeh Didari-Bader, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri 2023 Chapman University

Adaptive Plasmonic Metasurfaces For Radiative Cooling And Passive Thermoregulation, Azadeh Didari-Bader, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri

Engineering Faculty Articles and Research

In this work, we investigate a class of planar photonic structures operating as passive thermoregulators. The radiative cooling process is adjusted through the incorporation of a phase change material (Vanadium Dioxide, VO2) in conjunction with a layer of transparent conductive oxide (Aluminum-doped Zinc Oxide, AZO). VO2 is known to undergo a phase transition from the “dielectric” phase to the “plasmonic” or “metallic” phase at a critical temperature close to 68°C. In addition, AZO shows plasmonic properties at the long-wave infrared spectrum, which, combined with VO2, provides a rich platform to achieve low reflections across the …


Climate Of A Cave Laboratory Representative For Rock Art Caves In The Vézère Area (South-West France), Delphine Lacanette, Léna Bassel, Fabien Salmon, Jean-Christophe Portais, Bruno Bousquet, Rémy Chapoulie, Faten Ammari, Philippe Malaurent, Catherine Ferrier 2023 University of Bordeaux, CNRS, France

Climate Of A Cave Laboratory Representative For Rock Art Caves In The Vézère Area (South-West France), Delphine Lacanette, Léna Bassel, Fabien Salmon, Jean-Christophe Portais, Bruno Bousquet, Rémy Chapoulie, Faten Ammari, Philippe Malaurent, Catherine Ferrier

International Journal of Speleology

Leye Cave (Dordogne, France) is a laboratory cave in the Vézère area, a region that contains some of the most famous rock art caves in the world such as Lascaux, Font-de-Gaume and Combarelles, and is listed as Human World Heritage by UNESCO. Leye Cave was selected because it is representative of painted caves, with respect to parameters such as its geological stage, the presence of water and carbon dioxide, the geological state of its walls, and the size of the cave. These wall states are studied to better understand the conditions of conservation of rock art caves without damaging them. …


Fractional Charge Concept Opened Gates For New Ideas On Composition Of Matter, Polievkt Perov 2023 Suffolk University

Fractional Charge Concept Opened Gates For New Ideas On Composition Of Matter, Polievkt Perov

College of Arts & Sciences Faculty Works

Before the concept of quarks with fractional electric charges was introduced, the electron charge magnitude e was considered as the smallest amount of charge in nature so the charge of any object could be only an integer number of ± e. Then it was suggested that the proton and neutrons are composed of quarks with the fractional charges, combined in such a way that the total charge of a proton occurred to be that same known charge +e, and the charge of a neutron was zero. We suggest expanding that fruitful concept of fractional charges to build structural models of …


New Reaction Of Neutron-Proton Conversion, Polievkt Perov 2023 Suffolk University

New Reaction Of Neutron-Proton Conversion, Polievkt Perov

College of Arts & Sciences Faculty Works

Using our models of composite particles as consisting just of two types of elementary basic charges, +e/3 and -e/3, we suggest that in any nuclear reaction the total numbers of basic charges of each of the two types are conserved. That means that in any nuclear reaction, the basic elementary charges present in the reactants can join in different combinations to form the products of the reaction. This is like a balanced chemical equation where the number of atoms of each element is conserved. We apply this suggested principle of conservation of basic elementary charges in any nuclear reaction to …


Intrinsic Point Defects (Vacancies And Antisites) In Cdgep2 Crystals, Timothy D. Gustafson, Nancy C. Giles, Peter G. Schunemann, Kevin T. Zawilski, Kent L. Averett, Jonathan E. Slagle, Larry E. Halliburton 2023 Air Force Institute of Technology

Intrinsic Point Defects (Vacancies And Antisites) In Cdgep2 Crystals, Timothy D. Gustafson, Nancy C. Giles, Peter G. Schunemann, Kevin T. Zawilski, Kent L. Averett, Jonathan E. Slagle, Larry E. Halliburton

Faculty Publications

Cadmium germanium diphosphide (CdGeP2) crystals, with versatile terahertz-generating properties, belong to the chalcopyrite family of nonlinear optical materials. Other widely investigated members of this family are ZnGeP2 and CdSiP2. The room-temperature absorption edge of CdGeP2 is near 1.72 eV (720 nm). Cadmium vacancies, phosphorous vacancies, and germanium-on-cadmium antisites are present in as-grown CdGeP2 crystals. These unintentional intrinsic point defects are best studied below room temperature with electron paramagnetic resonance (EPR) and optical absorption. Prior to exposure to light, the defects are in charge states that have no unpaired spins. Illuminating a CdGeP2 …


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