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An Online E-Voting System Based On An Adaptive Ledger With Singular Value Decomposition Technique, Rihab Habeeb Sahib, Prof. Dr. Eman Salih Al-Shamery Dec 2021

An Online E-Voting System Based On An Adaptive Ledger With Singular Value Decomposition Technique, Rihab Habeeb Sahib, Prof. Dr. Eman Salih Al-Shamery

Karbala International Journal of Modern Science

Regular E-voting systems for elections may count the votes in less time,less cost,save the privacy of citizens,but still considered risky as votes can be tampered.E-voting systems based on a network distributed ledger show fast results,more trusted,save privacy,cannot be tampered,and distributed in which no central organization controls the system.This paper illustrate an e-voting system to solve the challenge of a massive ledger that is distributed among network-nodes using a data reduction technique as a security-matching-tool,singular value decomposition(SVD) that handle a copy of election results in another form and matched with the SQL-database results to announce a successful election-event representing a transparency-powerful-secured-system

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Detecting Malicious Dns Queries Over Encrypted Tunnels Using Statistical Analysis And Bi-Directional Recurrent Neural Networks, Mohammad Al-Fawa'reh, Zain Ashi, Mousa Tayseer Jafar Dec 2021

Detecting Malicious Dns Queries Over Encrypted Tunnels Using Statistical Analysis And Bi-Directional Recurrent Neural Networks, Mohammad Al-Fawa'reh, Zain Ashi, Mousa Tayseer Jafar

Karbala International Journal of Modern Science

The exponential rise in the number of malicious threats targeting computer networks and digital services puts network infrastructure in jeopardy. Domain name protocol attacks are one of the most pervasive network attacks posing a threat to networks, whereby attackers send harmful information to the network; this type of threat is identified as DNS tunneling. The DNS protocol has recently gained increased attention from cyber-attackers, targeting organizations with a web presence or reliance on e-commerce businesses. Cyber-attackers can subtly exploit the contents of encrypted DNS packets that are sent across covert network tunnels, which are difficult for firewalls and blacklist detection …

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Artificial Intelligence For Para Rubber Identification Combining Five Machine Learning Methods, Chairote Yaiprasert Ph.D. Dec 2021

Artificial Intelligence For Para Rubber Identification Combining Five Machine Learning Methods, Chairote Yaiprasert Ph.D.

Karbala International Journal of Modern Science

This study aims to identify Para rubber species using a combination of five machine learning techniques to classify leaf images. The learning process is defined using a dataset for each classification method. Approximately 1,472 leaf images are prepared consisting of various sizes, shapes, quality provided for the model. The classification indicators are defined with the help of an algorithm to identify at least three of the top five potential classification outcomes. The algorithm accurately predicts 100% of the five classification methods. Methods can provide precise and rapid classification of large quantities, without the need for image preprocessing prior to classification.

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Synergistic Extraction Of Silver From Nitric Acid Medium With Dithizone In The Presence Of A Secondary Amine- Amberlite La-2 Using 110mag-Radioisotope, Madhusudan Mandal Ph.D. Dec 2021

Synergistic Extraction Of Silver From Nitric Acid Medium With Dithizone In The Presence Of A Secondary Amine- Amberlite La-2 Using 110mag-Radioisotope, Madhusudan Mandal Ph.D.

Karbala International Journal of Modern Science

Synergistic extraction of silver has been investigated in the presence of two different kinds of extractants, one of which is a chelating ligand, dithizone and the other is a long-chain secondary amine amberlite LA-2 at pH 3.0 using a radiotracer technique. The apparent formation constant, overall equilibrium constant and adduct formation constants were calculated from distribution coefficients. Interestingly, it was observed that the adduct formation constant is too high when the ligand concentration is increased by keeping the amine concentration fixed at 0.044 M compared to that obtained when the ligand concentration is kept fixed at 8.74×10-4 M.

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Editorial Board Dec 2021

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

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Effects Of Anharmonicity In A Dual-Sagnac Interferometer, Stephen Thomas Dec 2021

Effects Of Anharmonicity In A Dual-Sagnac Interferometer, Stephen Thomas

Honors College Theses

A recent experiment implemented a dual Sagnac atom interferometer (AI) for rotation sensing using a Bose-Einstein condensate (BEC) confined in a TOP-trap potential. The BEC is split twice by laser light to create two pairs of counter-orbiting clouds in a lowest-order harmonic potential with each pair acting as a separate Sagnac interferometer. After one orbit the two overlapping cloud pairs are split again and the interference patterns are inferred from the population of atoms in the zero-momentum state. We have simulated the impact of the presence of anharmonic terms in the potential on the performance of the AI as measured …

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Extracellular Vimentin As A Target Against Sars-Cov-2 Host Cell Invasion, Łukasz Suprewicz, Maxx Swoger, Sarthak Gupta, Ewelina Piktel, Fitzroy J. Byfield, Daniel V. Iwamoto, Danielle Germann, Joanna Reszeć, Natalia Marcińczyk, Robert J. Carroll, Paul A. Janmey, J. M. Schwarz, Robert Bucki, Alison E. Patteson Dec 2021

Extracellular Vimentin As A Target Against Sars-Cov-2 Host Cell Invasion, Łukasz Suprewicz, Maxx Swoger, Sarthak Gupta, Ewelina Piktel, Fitzroy J. Byfield, Daniel V. Iwamoto, Danielle Germann, Joanna Reszeć, Natalia Marcińczyk, Robert J. Carroll, Paul A. Janmey, J. M. Schwarz, Robert Bucki, Alison E. Patteson

Physics - All Scholarship

Infection of human cells by pathogens, including SARS-CoV-2, typically proceeds by cell surface binding to a crucial receptor. The primary receptor for SARS-CoV-2 is the angiotensin-converting enzyme 2 (ACE2), yet new studies reveal the importance of additional extracellular co-receptors that mediate binding and host cell invasion by SARS-CoV-2. Vimentin is an intermediate filament protein that is increasingly recognized as being present on the extracellular surface of a subset of cell types, where it can bind to and facilitate pathogens’ cellular uptake. Biophysical and cell infection studies are done to determine whether vimentin might bind SARS-CoV-2 and facilitate its uptake. Dynamic …

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Accurate Flux Calibration Of Gw170817: Is The X-Ray Counterpart On The Rise?, E. Troja, B. O'Connor, G. Ryan, L. Piro, R. Ricci, B. Zhang, T. Piran, G. Bruni, S. B. Cenko, H. Van Eerten Dec 2021

Accurate Flux Calibration Of Gw170817: Is The X-Ray Counterpart On The Rise?, E. Troja, B. O'Connor, G. Ryan, L. Piro, R. Ricci, B. Zhang, T. Piran, G. Bruni, S. B. Cenko, H. Van Eerten

Physics & Astronomy Faculty Research

X-ray emission from the gravitational wave transient GW170817 is well described as non-thermal afterglow radiation produced by a structured relativistic jet viewed off-axis. We show that the X-ray counterpart continues to be detected at 3.3 years after the merger. Such long-lasting signal is not a prediction of the earlier jet models characterized by a narrow jet core and a viewing angle ≈20 deg, and is spurring a renewed interest in the origin of the X-ray emission. We present a comprehensive analysis of the X-ray dataset aimed at clarifying existing discrepancies in the literature, and in particular the presence of an …

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Evidence For Quasi-Periodic Oscillations In The Recurrent Emission From Magnetars And Their Implications On The Neutron Star Properties And Equation Of State, Ahmed Monzer El Mezeini Dec 2021

Evidence For Quasi-Periodic Oscillations In The Recurrent Emission From Magnetars And Their Implications On The Neutron Star Properties And Equation Of State, Ahmed Monzer El Mezeini

Archived Theses and Dissertations

In this thesis, we present an analysis of highly magnetized neutron stars â magnetarsâ , in search for high frequency oscillations in the recurrent emission from the soft gamma repeater SGR 1806-20, and we discuss the physical interpretation of these oscillations and its implications on the neutron star properties and structure. We present evidence for Quasi-Periodic Oscillations (QPOs) in the recurrent outburst activity from the soft gamma repeater SGR 1806-20 using Rossi X-ray Timing Explorer (RXTE) observations. By searching a large sample of bursts for timing signals at the frequencies of the QPOs discovered in the 2004 December 27 giant …

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Measurement Of Speed Of Sound Using Smartphones, Omotolani Adelekan Dec 2021

Measurement Of Speed Of Sound Using Smartphones, Omotolani Adelekan

Publications and Research

The goal of this experiment is to determine the speed of sound in air. To measure the speed of sound, I used two smartphones and an app called Phyphox This app uses the microphone of the smartphone to detect the time between two acoustic events The “acoustic stopwatch” tool on the app is used to measure the time between two sound signals These two signals are produced by hand clapping In this experiment, the speed of sound is determined using the time of flight method This method is based on measuring the time delay between the generation and the detection …

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Evidence For Surface Effects On The Intermolecular Interactions In Fe (Ii) Spin Crossover Coordination Polymers, Thilini K. Ekanayaka, Hannah Kurz, Kayleigh A. Mcelveen, Guanhua Hao, Esha Mishra, Alpha T. N’Diaye, Rebecca Lai, Birgit Weber, Peter A. Dowben Dec 2021

Evidence For Surface Effects On The Intermolecular Interactions In Fe (Ii) Spin Crossover Coordination Polymers, Thilini K. Ekanayaka, Hannah Kurz, Kayleigh A. Mcelveen, Guanhua Hao, Esha Mishra, Alpha T. N’Diaye, Rebecca Lai, Birgit Weber, Peter A. Dowben

Department of Physics and Astronomy: Faculty Publications

From X-ray absorption spectroscopy (XAS) and X-ray photoemission spectroscopy (XPS) it is evident that the spin state transition behavior of Fe(II) spin crossover coordination polymer crystallites at the surface differs from the bulk. A comparison of four different coordination polymers reveals that the observed surface properties may differ from bulk for a variety of reasons. There are Fe(II) spin crossover coordination polymers with either almost complete switching of the spin state at the surface or no switching at all. Oxidation, differences in surface packing, and changes in coordination could all contribute to making the surface very different from the bulk. …

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(R1480) Heat Transfer In Peristaltic Motion Of Rabinowitsch Fluid In A Channel With Permeable Wall, Mahadev M. Channakote, Dilipkumar V. Kalse Dec 2021

(R1480) Heat Transfer In Peristaltic Motion Of Rabinowitsch Fluid In A Channel With Permeable Wall, Mahadev M. Channakote, Dilipkumar V. Kalse

Applications and Applied Mathematics: An International Journal (AAM)

This paper is intended to investigate the effect of heat transfer on the peristaltic flow of Rabinowitsch fluid in a channel lined with a porous material. The Navier -Stokes equation governs the channel's flow, and Darcy's law describes the permeable boundary. The Rabinowitsch fluid model's governing equations are solved by utilizing approximations of the long-wavelength and small number of Reynolds. The expressions for axial velocity, temperature distribution, pressure gradient, friction force, stream function are obtained. The influence on velocity, pressure gradient, friction force, and temperature on pumping action of different physical parameters is explored via graphs.

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Quantum State Estimation And Tracking For Superconducting Processors Using Machine Learning, Shiva Lotfallahzadeh Barzili Dec 2021

Quantum State Estimation And Tracking For Superconducting Processors Using Machine Learning, Shiva Lotfallahzadeh Barzili

Computational and Data Sciences (PhD) Dissertations

Quantum technology has been rapidly growing; in particular, the experiments that have been performed with superconducting qubits and circuit QED have allowed us to explore the light-matter interaction at its most fundamental level. The study of coherent dynamics between two-level systems and resonator modes can provide insight into fundamental aspects of quantum physics, such as how the state of a system evolves while being continuously observed. To study such an evolving quantum system, experimenters need to verify the accuracy of state preparation and control since quantum systems are very fragile and sensitive to environmental disturbance. In this thesis, I look …

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Quantum State Tomography Of Molecules By Ultrafast Diffraction, Ming Zhang, Shuqiao Zhang, Yanwei Xiong, Hankai Zhang, Anatoly A. Ischenko, Oriol Vendrell, Xiaolong Dong, Xiangxu Mu, Martin Centurion, Haitan Xu, R. J.Dwayne Miller, Zheng Li Dec 2021

Quantum State Tomography Of Molecules By Ultrafast Diffraction, Ming Zhang, Shuqiao Zhang, Yanwei Xiong, Hankai Zhang, Anatoly A. Ischenko, Oriol Vendrell, Xiaolong Dong, Xiangxu Mu, Martin Centurion, Haitan Xu, R. J.Dwayne Miller, Zheng Li

Martin Centurion Publications

Ultrafast electron diffraction and time-resolved serial crystallography are the basis of the ongoing revolution in capturing at the atomic level of detail the structural dynamics of molecules. However, most experiments capture only the probability density of the nuclear wavepackets to determine the time-dependent molecular structures, while the full quantum state has not been accessed. Here, we introduce a framework for the preparation and ultrafast coherent diffraction from rotational wave packets of molecules, and we establish a new variant of quantum state tomography for ultrafast electron diffraction to characterize the molecular quantum states. The ability to reconstruct the density matrix, which …

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The Hashtag Project: The First Submillimeter Images Of The Andromeda Galaxy From The Ground, Matthew W.L. Smith, Stephen A. Eales, Thomas G. Williams, Bumhyun Lee, Zongnan Li, Pauline Barmby, Martin Bureau, Scott Chapman, Brian S. Cho, Aeree Chung, Eun Jung Chung, Hui Hsuan Chung, Christopher J.R. Clark, David L. Clements, Timothy A. Davis, Ilse De Looze, David J. Eden, Gayathri Athikkat-Eknath, George P. Ford, Yu Gao, Walter Gear, Haley L. Gomez, Richard De Grijs, Jinhua He, Luis C. Ho, Thomas M. Hughes, Sihan Jiao, Zhiyuan Li, Francisca Kemper Dec 2021

The Hashtag Project: The First Submillimeter Images Of The Andromeda Galaxy From The Ground, Matthew W.L. Smith, Stephen A. Eales, Thomas G. Williams, Bumhyun Lee, Zongnan Li, Pauline Barmby, Martin Bureau, Scott Chapman, Brian S. Cho, Aeree Chung, Eun Jung Chung, Hui Hsuan Chung, Christopher J.R. Clark, David L. Clements, Timothy A. Davis, Ilse De Looze, David J. Eden, Gayathri Athikkat-Eknath, George P. Ford, Yu Gao, Walter Gear, Haley L. Gomez, Richard De Grijs, Jinhua He, Luis C. Ho, Thomas M. Hughes, Sihan Jiao, Zhiyuan Li, Francisca Kemper

Physics and Astronomy Publications

Observing nearby galaxies with submillimeter telescopes on the ground has two major challenges. First, the brightness is significantly reduced at long submillimeter wavelengths compared to the brightness at the peak of the dust emission. Second, it is necessary to use a high-pass spatial filter to remove atmospheric noise on large angular scales, which has the unwelcome side effect of also removing the galaxy's large-scale structure. We have developed a technique for producing high-resolution submillimeter images of galaxies of large angular size by using the telescope on the ground to determine the small-scale structure (the large Fourier components) and a space …

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Clmm: A Lsst-Desc Cluster Weak Lensing Mass Modeling Library For Cosmology, H. Wu Dec 2021

Clmm: A Lsst-Desc Cluster Weak Lensing Mass Modeling Library For Cosmology, H. Wu

Physics Faculty Publications and Presentations

We present the v1.0 release of CLMM, an open source PYTHON library for the estimation of the weak lensing masses of clusters of galaxies. CLMM is designed as a stand-alone toolkit of building blocks to enable end-to-end analysis pipeline validation for upcoming cluster cosmology analyses such as the ones that will be performed by the Vera C. Rubin Legacy Survey of Space and Time-Dark Energy Science Collaboration (LSST-DESC). Its purpose is to serve as a flexible, easy-to-install, and easy-to-use interface for both weak lensing simulators and observers and can be applied to real and mock data to study the systematics …

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Lorentz Violations And The Casimir Effect, Samuel G. Christensen Dec 2021

Lorentz Violations And The Casimir Effect, Samuel G. Christensen

Physics

The background and calculation for the corrections to the Casimir Energy stored on parallel conducting plates due to minimal violations of Lorentz invariance are presented as a test of the Standard Model. A direction-dependent photon dispersion relation using operators of dimension 4 and higher is used in the calculation of the spacetime anisotropy correction terms to the Casimir energy. The calculation includes discussion of Riemann zeta function regularization and its equivalence to Euler-Maclaurin sum-integral formulas in a Casimir effect calculation. The two plate geometry result is mapped onto a one plate and sphere geometry to cater to modern precision tests …

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Rigid Aggregation Of Inclusions Embedded In Quasi 2d Fluids, Natalie Xochitl Ryan Dec 2021

Rigid Aggregation Of Inclusions Embedded In Quasi 2d Fluids, Natalie Xochitl Ryan

Physics

Diffusion is a transport process common in several biological systems. In this process particles of different species mix together through random (stochastic) motion at molecular length scales. Diffusion in fluids is unique as the coupling of the flow and fluid have been found to produce giant concentration fluctuations. The molecular length scale of these concentration fluctuations are magnitudes larger than the movement of the particles themselves, earning them the title “giant”. The diffusion of particles in bio-membranes displays a combination of 2D and 3D hydrodynamic properties; the movements of the particles are restricted to the plane of the membrane and …

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Electroluminescent Signals And Cosmogenicbackgrounds In High Pressure Xenon Gas Timeprojection Detectors, Leslie Rogers Dec 2021

Electroluminescent Signals And Cosmogenicbackgrounds In High Pressure Xenon Gas Timeprojection Detectors, Leslie Rogers

Physics Dissertations - Archive

The NEXT collaboration is developing a sequence of high pressure xenon gas time projection chambers with the aim of creating a ton-scale, very low background neutrinoless double beta decay search. Finding evidence of neutrinoless double beta decay would give insight into the origins of the matter-antimatter asymmetry in the universe, the smallness of neutrino mass, and the symmetry structure of the Standard Model. My research involves addressing critical challenges on the path to realization of high pressure xenon gas detectors for ton-scale, very low background neutrinoless double beta decay searches. While most aspects of this technology are easily scalable, some …

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Gpu-Based Monte Carlo Applications In Radiation Medicine, Youfang Lai Dec 2021

Gpu-Based Monte Carlo Applications In Radiation Medicine, Youfang Lai

Physics Dissertations - Archive

Radiation can be used to image tumor site or kill tumor cells noninvasively, playing an important role in tumor diagnosis and treatment. Because of the increasing burden that cancer brings to the society, there always exists the demand of improving imaging resolution and contrast and improving radiation conformity for therapy. This depends on not only the advances of techniques, but, probably more importantly, the accurate and efficient modelling of radiation transport, enabling research on proof-of-concept for new tech and more complicated physics and chemical process in a quantitative way. Monte Carlo (MC) simulation method has been extensively used in medical …

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Understanding Students’ Global Interdependence In Science Instruction, Walter S. Smith Dec 2021

Understanding Students’ Global Interdependence In Science Instruction, Walter S. Smith

Journal of Global Education and Research

Multiple American educational organizations such as the National Education Association, Association for Supervision and Curriculum Development, and the Council of Chief State School Officers have advocated for globalizing the K-12 curriculum. The National Science Teaching Association (NSTA) in a position statement on international education and the Next Generation Science Standards have produced goals and standards for internationalizing the science curriculum by addressing topics such as climate change, environment, and disease that cross borders. In contrast to those pronouncements on the curriculum, this article views global science education through an instructional lens that focuses on a students’ global interdependence in science …

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Energy Dissipation During Geomagnetic Storms, Fatemeh Bagheri Dec 2021

Energy Dissipation During Geomagnetic Storms, Fatemeh Bagheri

Physics Dissertations - Archive

Some fraction of the solar wind energy is transferred to the Earth magnetosphere and ionosphere. Sometimes this transfer of energy is exceptionally large, producing a magnetic storm. Storms occur when the Interplanetary Magnetic Field (IMF) turns southward and remains southward for an extended period of time. During the main phase of many magnetic storms, the solar wind Mach number is low, and IMF magnitude is large. Under these conditions, the ionospheric potential saturates, and it becomes relatively insensitive to further increases in the IMF magnitude. On the other hand, the dayside merging rate and the potential become sensitive to the …

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The Arecibo Observatory As An Instrument For Investigating Orbital Debris, James Isaiah Murray Dec 2021

The Arecibo Observatory As An Instrument For Investigating Orbital Debris, James Isaiah Murray

Physics Dissertations - Archive

In this dissertation, the Arecibo Observatory, both past and future, as an instrument for investigating orbital debris is investigated. For over three decades, models of the orbital debris environment in low Earth orbit (LEO) have been developed to assess the risk posed by orbital debris to spacecraft. While terrestrial radar measures debris 3 mm and larger and in-situ measurements provide data for debris smaller than 1 mm, no good data sources exist for debris between 1 mm and 3 mm in size. This results in large variations between competing orbital debris models. It also happens to be the size regime …

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Electronic And Magnetic Properties Of Metal Doped Silicon-Carbide Fullerene-Type Nanostructures, Hussain Jabreel Alathlawi Dec 2021

Electronic And Magnetic Properties Of Metal Doped Silicon-Carbide Fullerene-Type Nanostructures, Hussain Jabreel Alathlawi

Physics Dissertations - Archive

Silicon carbide (SiC) is a technologically significant material. A recent report on the abundance of C60 fullerenes in interstellar space, along with the presence of SiC precursors, sparked interest in potentially similar SiC nanostructures. C60 and C70 fullerenes were found experimentally and are an exceptionally stable form of carbon. As Si and C have similar valence electron configurations, it has been long envisioned that Si and SiC could also form similar fullerene-type structures. In this dissertation, Si30C30 fullerene-derived clusters were studied from the first principles theory, starting from an ideal Si60 fullerene template with various arrangements of silicon and carbon …

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Nonlinear Mode Coupling Coefficients In Extrasolar Hot Jupiter Systems With Non-Solar Type Host Stars, Niyousha Davachi Dec 2021

Nonlinear Mode Coupling Coefficients In Extrasolar Hot Jupiter Systems With Non-Solar Type Host Stars, Niyousha Davachi

Physics Theses - Archive

Short period planets tidally excite internal gravity modes within their host star. These excited modes, known collectively as the dynamical tide, dissipate orbital energy and cause the planet’s orbit to decay. In hot Jupiter systems, resonantly excited gmodes are driven to such large amplitudes in the stellar core that they nonlinearly excite a sea of secondary modes. These secondary modes can greatly enhance the efficiency of tidal dissipation compared to linear theory predictions and thus significantly increase the rate of orbital decay. In this thesis we calculate the three-mode coupling coefficients between the excited g-modes of hot Jupiter host stars. …

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Experimental Measurement Of Sharp Thz Absorption Signatures From Nucleic Acid Solutions In Nanofluidic Channels, Elliott R. Brown, Edgar A. Mendoza Dec 2021

Experimental Measurement Of Sharp Thz Absorption Signatures From Nucleic Acid Solutions In Nanofluidic Channels, Elliott R. Brown, Edgar A. Mendoza

Physics Faculty Publications

We report on the room-temperature experimental measurement of THz absorption signatures in aqueous, double-stranded nucleic acid solutions confined to the submicron silica channels on fused quartz substrates using THz frequency-domain (photomixing) spectroscopy. Three sharp (i.e., strong and narrow) signatures, ~10–20 GHz FWHM, are observed in the shortest base pair sample—small interfering, double-stranded (ds) RNA—in the range of 800 GHz to 1.1 THz. Three similar signatures are also observed in a 50-bp dsDNA ladder sample. For a 1-kbp dsDNA ladder sample, the three are still evident, but are broadened and weakened. For a 48.5-kbp sample (λ-DNA), no prominent signatures are observed, …

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Spectral Dependence Of Deep Subwavelength Metallic Apertures In The Mid-Wave Infrared, Heath Gemar Dec 2021

Spectral Dependence Of Deep Subwavelength Metallic Apertures In The Mid-Wave Infrared, Heath Gemar

Electronic Theses and Dissertations, 2020-2023

For two decades, extraordinary optical transmission (EOT) has amplified exploration into subwavelength systems. Researchers have previously suggested exploiting the spectrally selective electromagnetic field confinement of subwavelength cavities for multispectral detectors. Utilizing the finite-difference frequency domain (FDFD) method, we examine electromagnetic field confinement in both 2-dimensional and 3-dimensional scenarios from 2.5 to 6 microns (i.e., mid-wave infrared or MWIR). We explore the trade space of deep subwavelength cavities and its impact on resonant enhancement of the electromagnetic field. The studies provide fundamental understanding of the coupling mechanisms allowing for prediction of resonant spectral behavior based on cavity geometry and material properties. …

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High Spectral Brightness, Broad Area Quantum Cascade Lasers, Enrique Sanchez Cristobal Dec 2021

High Spectral Brightness, Broad Area Quantum Cascade Lasers, Enrique Sanchez Cristobal

Electronic Theses and Dissertations, 2020-2023

Quantum cascade lasers are unipolar semiconductor lasers that offer a unique combination of compact size, high efficiency, high optical power, and flexibility to achieve a targeted emission wavelength with the same laser core material composition, employing so-called bandgap engineering. Since their invention in 1994, watt-level CW power with 5 to 20 % wallplug efficiency was demonstrated for QCLs throughout the entire 4 to 12 µm range, which makes QCLs very attractive for a number of practical applications. Our earlier work on broad-area QCLs emitting in the 4.6 µm to 5.7 µm spectral range demonstrated that CW power scaling with lateral …

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Wavelet Particle Hydrodynamics For Less Smooth Flow, Oddny Brun Dec 2021

Wavelet Particle Hydrodynamics For Less Smooth Flow, Oddny Brun

Electronic Theses and Dissertations, 2020-2023

The purpose of this research was to improve the smoothing operation in smoothed particle hydrodynamics, SPH, when the flow of matter is not smooth. Our main focuses are on the kernel selection, identifying the discontinuities in the sequences to be smoothed, and use of the Laplacian as opposed to artificial viscosity for improved physical accuracy. The results show that alternative kernels result in differences in how matter flows. These effects are explained by the kernels' gradient and Laplacian properties. Five alternative kernels were included in our analysis and our SPH-based simulation cases. Further, the sequences to be smoothed by the …

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Nonlinear Light-Matter Interactions In Novel Crystals For Broadband Mid-Infrared Generation, Taiki Kawamori Dec 2021

Nonlinear Light-Matter Interactions In Novel Crystals For Broadband Mid-Infrared Generation, Taiki Kawamori

Electronic Theses and Dissertations, 2020-2023

Mid-infrared (MIR) laser sources have demonstrated diverse applications in science and technology. For spectroscopy applications, numerous molecules have unique absorption features in this range, and one needs a spectrally broad coherent laser source for parallel detection of mixtures of species. Frequency down-conversion in nonlinear optical materials via second-order nonlinear susceptibility is one of the promising techniques to generate the spectral coverage of more than an octave in the MIR, assisted by emerging novel crystals. The nonlinear light-matter interactions in such special crystals as ZnSe ceramics have not been analyzed. Additionally, through the use of high-intensity few-cycle optical pulses, high-order nonlinear …

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