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Articles 781 - 810 of 36522

Full-Text Articles in Physical Sciences and Mathematics

Commissioning Of The Uaeu Radio Array And Pilot Low-Frequency Radio Astronomy Studies, Aisha Ali Alnaqbi Nov 2023

Commissioning Of The Uaeu Radio Array And Pilot Low-Frequency Radio Astronomy Studies, Aisha Ali Alnaqbi

Thesis/ Dissertation Defenses

As part of the UAEU Radio Astronomy Pathway Project, a 256-element Ground-based Radio Array Facility was deployed at the UAEU. A comprehensive exploration of radio astronomy, and investigations on existing radio arrays, emphasizing low-frequency radio signals and the challenges faced at this range, are crucial for the commissioning phase of the array. A core aspect discussed is the vital role of coaxial cables in preserving the integrity of low-frequency radio signals. To address the electrical length differences between the coaxial cable pairs used to connect the array’s beamformers in the field to the beamformer controllers in the control room, precise …

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Influence Of Thickness And Capping Materials On The Static And Dynamic Properties Of Ferrimagnetic Thin Films, Noha Alzahrani Nov 2023

Influence Of Thickness And Capping Materials On The Static And Dynamic Properties Of Ferrimagnetic Thin Films, Noha Alzahrani

USF Tampa Graduate Theses and Dissertations

Spintronics traditionally relied on ferromagnetic materials for their strong spin properties but facedissues like large stray magnetic fields. To address these challenges, researchers turned to antiferromagnetic materials with fast spin dynamics, due to their zero net magnetic moment but the lack of a net spin moment complicated operation. In this context, ferrimagnetic materials have emerged as promising alternatives. They combine ferromagnetic and antiferromagnetic traits and feature different magnetic ions in their sublattices. This dissertation explores how film thickness and capping materials affect the properties of ferrimagnetic thin films. Rare-earth transition metal ferrimagnetic amorphous alloys have garnered attention in the realm …

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Relativistic Ultrafast Electron Diffraction At High Repetition Rates, K. M. Siddiqui, D. B. Durham, F. Cropp, F. Ji, S. Paiagua, C. Ophus, N. C. Andresen, L. Jin, J. Wu, S. Wang, X. Zhang, W. You, M. Murnane, Martin Centurion, X. Wang, D. S. Slaughter, R. A. Kaindl, P. Musumeci, A. M. Minor, D. Filippetto Nov 2023

Relativistic Ultrafast Electron Diffraction At High Repetition Rates, K. M. Siddiqui, D. B. Durham, F. Cropp, F. Ji, S. Paiagua, C. Ophus, N. C. Andresen, L. Jin, J. Wu, S. Wang, X. Zhang, W. You, M. Murnane, Martin Centurion, X. Wang, D. S. Slaughter, R. A. Kaindl, P. Musumeci, A. M. Minor, D. Filippetto

Martin Centurion Publications

The ability to resolve the dynamics of matter on its native temporal and spatial scales constitutes a key challenge and convergent theme across chemistry, biology, and materials science. The last couple of decades have witnessed ultrafast electron diffraction (UED) emerge as one of the forefront techniques with the sensitivity to resolve atomic motions. Increasingly sophisticated UED instruments are being developed that are aimed at increasing the beam brightness in order to observe structural signatures, but so far they have been limited to low average current beams. Here, we present the technical design and capabilities of the HiRES (High Repetition-rate Electron …

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Weak Measurements And Quantum-To-Classical Transitions In Free Electron–Photon Interactions, Yiming Pan, Eliahu Cohen, Ebrahim Karimi, Avraham Gover, Norbert Schönenberger, Tomáš Chlouba, Kangpeng Wang, Saar Nehemia, Peter Hommelhoff, Ido Kaminer, Yakir Aharonov Nov 2023

Weak Measurements And Quantum-To-Classical Transitions In Free Electron–Photon Interactions, Yiming Pan, Eliahu Cohen, Ebrahim Karimi, Avraham Gover, Norbert Schönenberger, Tomáš Chlouba, Kangpeng Wang, Saar Nehemia, Peter Hommelhoff, Ido Kaminer, Yakir Aharonov

Mathematics, Physics, and Computer Science Faculty Articles and Research

How does the quantum-to-classical transition of measurement occur? This question is vital for both foundations and applications of quantum mechanics. Here, we develop a new measurement-based framework for characterizing the classical and quantum free electron–photon interactions and then experimentally test it. We first analyze the transition from projective to weak measurement in generic light–matter interactions and show that any classical electron-laserbeam interaction can be represented as an outcome of weak measurement. In particular, the appearance of classical point-particle acceleration is an example of an amplified weak value resulting from weak measurement. A universal factor, exp(-Γ2/2) , quantifies the …

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Wide Range Thin-Film Ceramic Metal-Alloy Thermometers With Low Magnetoresistance, Nathanael Fortune, Joyce E. Palmer-Fortune, A. Trainer, A. Bangura, N. Kondedan, A. Rydh Nov 2023

Wide Range Thin-Film Ceramic Metal-Alloy Thermometers With Low Magnetoresistance, Nathanael Fortune, Joyce E. Palmer-Fortune, A. Trainer, A. Bangura, N. Kondedan, A. Rydh

Physics: Faculty Publications

Many thermal measurements in high magnetic fields require thermometers that are sensitive over a wide temperature range, are low mass, have a rapid thermal response, and have a minimal, easily correctable magnetoresistance. Here we report the development of a new granular-metal oxide ceramic composite (cermet) for this purpose formed by co-sputtering of the metallic alloy nichrome Ni0.8Cr0.2 and the insulator silcon dioxide SiO2. The resulting thin films are sensitive enough to be used from room temperature down to below 100 mK in magnetic fields up to at least 35 tesla.

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Effect Of Hf Alloying On Magnetic, Structural, And Magnetostrictive Properties In Feco Films For Magnetoelectric Heterostructure Devices, Thomas Mion, Margo Staruch, Konrad Bussmann, Goran Karapetrov, Olaf Van 'T Erve, Sara Mills, Heonjune Ryou, Ramasis Goswami, Patrick G. Callahan, David J. Rowenhorst, Syed B. Qadri, Samuel Lofland, Peter Finkel Nov 2023

Effect Of Hf Alloying On Magnetic, Structural, And Magnetostrictive Properties In Feco Films For Magnetoelectric Heterostructure Devices, Thomas Mion, Margo Staruch, Konrad Bussmann, Goran Karapetrov, Olaf Van 'T Erve, Sara Mills, Heonjune Ryou, Ramasis Goswami, Patrick G. Callahan, David J. Rowenhorst, Syed B. Qadri, Samuel Lofland, Peter Finkel

College of Science & Mathematics Departmental Research

Materials with high magnetoelectric coupling are attractive for use in engineered multiferroic heterostructures with applications such as ultra-low power magnetic sensors, parametric inductors, and non-volatile random-access memory devices. Iron-cobalt alloys exhibit both high magnetostriction and high saturation magnetization that are required for achieving significantly higher magnetoelectric coupling. We report on sputter-deposited (Fe0.5Co0.5)1-xHfx (x = 0 - 0.14) alloy thin films and the beneficial influence of Hafnium alloying on the magnetic and magnetostrictive properties. We found that co-sputtering Hf results in the realization of the peening mechanism that drives film stress from highly tensile to slightly compressive. Scanning electron microscopy and …

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System-Level Noise Performance Of Coherent Imaging Systems, Derek J. Burrell, Joshua H. Follansbee, Mark F. Spencer, Ronald G. Driggers Nov 2023

System-Level Noise Performance Of Coherent Imaging Systems, Derek J. Burrell, Joshua H. Follansbee, Mark F. Spencer, Ronald G. Driggers

Faculty Publications

We provide an in-depth analysis of noise considerations in coherent imaging, accounting for speckle and scintillation in addition to “conventional” image noise. Specifically, we formulate closed-form expressions for total effective noise in the presence of speckle only, scintillation only, and speckle combined with scintillation. We find analytically that photon shot noise is uncorrelated with both speckle and weak-to-moderate scintillation, despite their shared dependence on the mean signal. Furthermore, unmitigated speckle and scintillation noise tends to dominate coherent-imaging performance due to a squared mean-signal dependence. Strong coupling occurs between speckle and scintillation when both are present, and we characterize this behavior …

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Contributions Of Tunneling In 8Π-6Π Electrocyclic Cascade Reactions Of Bicyclo[4.2.0]Octa-2,4-Diene Moieties, Ishika Jain, Claire Castro, William L. Karney Nov 2023

Contributions Of Tunneling In 8Π-6Π Electrocyclic Cascade Reactions Of Bicyclo[4.2.0]Octa-2,4-Diene Moieties, Ishika Jain, Claire Castro, William L. Karney

Featured Student Work

Six-electron electrocyclic reactions usually require relatively high temperatures; however recent research has shown that such reactions can occur at significantly lower temperatures in biosynthetic and biomimetic pathways. Pathways resulting in bicyclo[4.2.0]octa-2,4-diene moieties arise from thermally allowed 8π-6π electrocyclization cascade reactions of 1,3,5,7-octatetraenes, as in the biosynthesis of endiandric acids, elysiapyrones, and numerous other natural products. We report multidimensional tunneling calculations to explore the possible contribution of heavy-atom tunneling (e.g. by carbon) to biosynthetic pathways and biomimetic syntheses, and thus to provide a more complete picture of biochemical kinetics. M06-2X/cc-pVDZ calculations on the 8π-6π cascade cyclizations of methylated octatetraene model systems …

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Identification Of Selected Persistent Organic Pollutants In Agricultural Land By Carbon Nitride (C3n5) Based Nano Sensors, Puspamitra Panigrahi, P. S. Anuroop, Hoonkyung Lee, Hyeonhu Bae, Thanayut Kaewmaraya, Ravindra Pandey, Tanveer Hussain, Akshaya Panigrahi Nov 2023

Identification Of Selected Persistent Organic Pollutants In Agricultural Land By Carbon Nitride (C3n5) Based Nano Sensors, Puspamitra Panigrahi, P. S. Anuroop, Hoonkyung Lee, Hyeonhu Bae, Thanayut Kaewmaraya, Ravindra Pandey, Tanveer Hussain, Akshaya Panigrahi

Michigan Tech Publications, Part 2

Efficient detection of selected persistent organic pollutants (POPs) is extremely important for the safety of humans and for the moderation of agriculture. This calls for the design of versatile nanosensors capable of sensing toxic POPs with high sensitivity and selectivity. Inspired by this, the sensing characteristics of carbon nitride (C3N5) monolayers toward selected POPs are reported, such as Dichlorodiphenyltrichloroethane (DDT), Methoxychlor (DMDT), Fenthion (FT), Fenitrothion (FNT), and Rennol (RL), employing density functional theory calculations. Analysis of results predicts adsorption energies of −0.93, −1.55, −1.44, −0.98, and −1.15 eV for DDT, DMDT, FT, FNT, and RM, respectively, on C3N5 monolayers. Significant …

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Modeling Single And Multiple Pacemaker Interaction In Jellyfish Locomotion, Alexander Hoover Nov 2023

Modeling Single And Multiple Pacemaker Interaction In Jellyfish Locomotion, Alexander Hoover

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

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Langevin Dynamic Models For Smfret Dynamic Shift, David Frost, Keisha Cook Dr, Hugo Sanabria Dr Nov 2023

Langevin Dynamic Models For Smfret Dynamic Shift, David Frost, Keisha Cook Dr, Hugo Sanabria Dr

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

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Probing The Electroweak Phase Transition With Exotic Higgs Decays, Marcela Carena, Jonathan Kozaczuk, Zhen Liu, Tong Ou, Michael J. Ramsey-Musolf, Jessie Shelton, Yikun Wang, Ke-Pan Xie Nov 2023

Probing The Electroweak Phase Transition With Exotic Higgs Decays, Marcela Carena, Jonathan Kozaczuk, Zhen Liu, Tong Ou, Michael J. Ramsey-Musolf, Jessie Shelton, Yikun Wang, Ke-Pan Xie

Department of Physics and Astronomy: Faculty Publications

An essential goal of the Higgs physics program at the LHC and beyond is to explore the nature of the Higgs potential and shed light on the mechanism of electroweak symmetry breaking. An important class of models alter the thermal history of electroweak symmetry breaking from the predictions of the Standard Model (SM). This paper reviews the existence of a region of parameter space where a strong first-order electroweak phase transition is compatible with exotic decays of the SM-like Higgs boson. A dedicated search for exotic Higgs decays can actively explore this framework at the Large Hadron Collider (LHC), while …

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Estimating Mars Surface Wind Stress And Dust Lifting Using Reanalyses Based On Emm And Other Spacecraft Observations, Haneen Edhar Abouhaligah Nov 2023

Estimating Mars Surface Wind Stress And Dust Lifting Using Reanalyses Based On Emm And Other Spacecraft Observations, Haneen Edhar Abouhaligah

Thesis/ Dissertation Defenses

Dust is the primary aerosol in Mars’ atmosphere and has strong interactions with visible light from the Sun and infrared emission from the surface and air. Understanding dust dynamics in the Martian atmosphere is critical for our understanding of its weather and climate. The rate at which dust is lifted from the surface at different locations is very difficult to measure yet determines the amount of dust in the atmosphere at any given time. This thesis investigates the role of near-surface wind stress (NSWS) and dust lifting rates, using six reanalysis datasets, respectively: MACDA, EMARS, OpenMARS, ACS-TIRVIM (ExoMars observations of …

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Green Synthesized Silver Nanoparticles-Based Sensing For Monitoring Water Pollution: An Updated Review, Muhamad Allan Serunting, Muhammad Ali Zulfikar, Henry Setiyanto, Dian Ayu Setyorini, Vienna Saraswaty Nov 2023

Green Synthesized Silver Nanoparticles-Based Sensing For Monitoring Water Pollution: An Updated Review, Muhamad Allan Serunting, Muhammad Ali Zulfikar, Henry Setiyanto, Dian Ayu Setyorini, Vienna Saraswaty

Karbala International Journal of Modern Science

Water is a basic human need and has been heavily contaminated. Therefore, it becomes a concern to remove the pollutant and monitor its quality. The removal methods include precipitation, filtration, adsorption, and photodegradation. Meanwhile, the monitoring can be done by measuring and analyzing the contaminant using spectrophotometry and chromatography. Nevertheless, those methods usually need a complicated preparation, and are expensive. Thus, a simple method is necessary to overcome these drawbacks by developing a sensor. In recent years, the sensor performance has been enhanced by using nanomaterials, such as silver nanoparticles (AgNPs). AgNPs can be synthesized using plant extracts through a …

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Synthesis And Characterization Of Zirconium Oxide Nanoparticles Using Z. Officinale And S. Aromaticum Plant Extracts For Antibacterial Application, M. J. Tuama, M. F. A. Alias Nov 2023

Synthesis And Characterization Of Zirconium Oxide Nanoparticles Using Z. Officinale And S. Aromaticum Plant Extracts For Antibacterial Application, M. J. Tuama, M. F. A. Alias

Karbala International Journal of Modern Science

Abstract The dramatic rise in bacterial infections and increased resistance to conventional antibiotics has led to the exploration of biologically derived nanomaterials to counteract bacterial activity. Nanotechnology, which deals with materials at the atomic or molecular level, is a promising way to achieve this goal. Zirconium oxide nanoparticles (ZrO2NPs) have shown strong antibacterial effects due to the increased surface-to-volume ratio at the nanoscale. This study focused on the production of ZrO2NPs in an environmentally friendly manner, which included extracts from Zingiber officinale (ginger), where G-ZrO2NPs were produced, and Syzygium aromaticum (clove), which produced S-ZrO2NPs. Various techniques were used, such as …

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First Principles Investigation Of Energy Harvesting Materials For Green Environment, Mehreen Javed Nov 2023

First Principles Investigation Of Energy Harvesting Materials For Green Environment, Mehreen Javed

Dissertations

The cutting-edge research of materials enables the discovery of novel energy harvesting materials. In this project the structural, electronic, magnetic, thermodynamic, thermoelectric, and optical properties of different energy harvesting materials are studied. The main objective of this work is primarily to study thermoelectrically efficient half-heuslers and photovoltaically active perovskites. Variant schematics of innovative compounds with defect introduction are investigated. The compositionally altered compounds designed by introducing crystallographic defects in terms of substitutional or interstitial dopants, offer new trends of material properties. To accomplish the task, Density Functional theory based computational packages (VASP and Wein2K) are used. Using defect and strain …

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Electrical, Optical, And Thermal Properties Of Snse Based Materials With High Thermoelectric Performances, Najwa Qasem Al Bouzieh Nov 2023

Electrical, Optical, And Thermal Properties Of Snse Based Materials With High Thermoelectric Performances, Najwa Qasem Al Bouzieh

Dissertations

This thesis conducts a thorough exploration of the characteristics and prospective applications of Tin Selenide (SnSe), a pivotal semiconductor for advancing contemporary electronics and optoelectronics. The investigation mainly focuses on comprehending the alterations in SnSe's properties when doped with elements such as Hafnium, Zinc, Bismuth, Germanium, Sodium, Iodine, and Silicon. 2D-SnSe allotropes, when doped with Hafnium, have exhibited remarkable optical characteristics, especially in the δ-SnSe allotrope, rendering it adaptable for varied optical uses like solar cells and LEDs. Additionally, evaluations of elasticity show improved resilience and augmented in-plane stiffness owing to Hf doping, occasionally reducing ductility. The work uniquely emphasizes …

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Equilibrium And Quench-Dynamical Studies Of Ultracold Fermions In Ring-Shaped Optical Traps, Daniel Gordon Allman Nov 2023

Equilibrium And Quench-Dynamical Studies Of Ultracold Fermions In Ring-Shaped Optical Traps, Daniel Gordon Allman

Dartmouth College Ph.D Dissertations

The unique capability to precisely tune the few and many-body configurations of
ultracold Fermi gases provides a multi-dimensional platform for studying novel, ex-
otic aspects of quantum systems. These aspects include superfluid/superconducting
phenomena supported by potentially exotic pairing mechanisms, non-equilibrium and
critical dynamics, and proposed quantum sensing or computing applications based on
atomtronics.
Ring geometries provide natural arenas for probing transport properties of super-
fluids. Metastable states of quantized superfluid flow —persistent currents— exhibit
remarkable properties, and the manner in which they form is an incredibly rich sub-
ject. Studies of quenched superfluids demonstrate that persistent currents can form
from …

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Commissioning Of The Uaeu Radio Array And Pilot Low-Frequency Radio Astronomy Studies, Aisha Ali Alnaqbi Nov 2023

Commissioning Of The Uaeu Radio Array And Pilot Low-Frequency Radio Astronomy Studies, Aisha Ali Alnaqbi

Theses

As part of the UAEU Radio Astronomy Pathway Project, a 256-element Ground based Radio Array Facility was deployed at the UAEU. A comprehensive exploration of radio astronomy, and investigations on existing radio arrays, emphasizing low-frequency radio signals and the challenges faced at this range, are crucial for the commissioning phase of the array. A core aspect discussed is the vital role of coaxial cables in preserving the integrity of low-frequency radio signals. To address the electrical length differences between the coaxial cable pairs used to connect the array’s beamformers in the field to the beamformer controllers in the control room, …

Go to article

Estimating Mars Surface Wind Stress And Dust Lifting Using Reanalyses Based On Emm And Other Spacecraft Observations, Haneen Abouhaligah Nov 2023

Estimating Mars Surface Wind Stress And Dust Lifting Using Reanalyses Based On Emm And Other Spacecraft Observations, Haneen Abouhaligah

Theses

Studying Mars offers insights into terrestrial planet evolution and informs future human expeditions. This thesis examines dust dynamics in Mars’ lower atmosphere, focusing on understanding its weather and climate. We investigate the role of Near-Surface Wind Stress (NSWS) in dust lifting, using six reanalysis datasets, respectively: MACDA, EMARS, OpenMARS, ACS–TIRVIM (ExoMars observations of the MY34 Global Dust storm), EMM1 and EMM2. Following the parameterization approach by Newman et al. (2002a), areas of agreement and discrepancy among datasets were identified. Time series analysis revealed consistent results where datasets overlap temporally. Some differences were expected and shown due to the different Global …

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Coastal Bathymetry Of The United Arab Emirates Using Satellite-Based Remote Sensing Data, Naser Salem Aldahmani Nov 2023

Coastal Bathymetry Of The United Arab Emirates Using Satellite-Based Remote Sensing Data, Naser Salem Aldahmani

Theses

Bathymetry is the study of the bed under the water's surface, giving us the water's depth. The Thesis will be about studying the coastal area of the UAE by using satellite images that can help access large regions of the UAE Coast. Also, by using a history of 5 years of satellite visible bands and NIR images, we can see the change of depth near the coastal. The benefit of that study will help to build ship baths through shallow water and to go in and out of ports of UAE. Early warnings of the sea level increasing near the …

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Radio Emission From Low Mass Active Galactic Nuclei, Ammara Aftab Nov 2023

Radio Emission From Low Mass Active Galactic Nuclei, Ammara Aftab

Theses

Massive black holes of a few million to billion solar masses lurk at the centers of the most present-day massive galaxies but their origin is still unknown. The low mass galaxies (M* ~ 3x109 Mʘ) hosting black holes with masses ranging from 103 to 105 Mʘ are ideal laboratories to test the models of black hole formation and they may help in understanding the co-evolution of central black holes with their host galaxies. In this thesis, we have developed a detailed theoretical model/framework to estimate the radio emission from low-mass active galactic nuclei (AGN). We also compute …

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Radio Emission From Low-Mass Active Galactic Nuclei, Ammara Aftab Nov 2023

Radio Emission From Low-Mass Active Galactic Nuclei, Ammara Aftab

Theses

Massive black holes of a few million to billion solar masses lurk at the centers of the most present-day massive galaxies but their origin is still unknown. The low mass galaxies (M* ~ 3x109 Mʘ ) hosting black holes with masses ranging from 103 to 105 Mʘ are ideal laboratories to test the models of black hole formation and they may help in understanding the co-evolution of central black holes with their host galaxies. In this thesis, we have developed a detailed theoretical model/framework to estimate the radio emission from low-mass active galactic nuclei (AGN). We also …

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Impact Of Silicon Ion Irradiation On Aluminum Nitride-Transduced Microelectromechanical Resonators, David D. Lynes, Joshua Young, Eric Lang, Hengky Chandrahalim Nov 2023

Impact Of Silicon Ion Irradiation On Aluminum Nitride-Transduced Microelectromechanical Resonators, David D. Lynes, Joshua Young, Eric Lang, Hengky Chandrahalim

Faculty Publications

Microelectromechanical systems (MEMS) resonators use is widespread, from electronic filters and oscillators to physical sensors such as accelerometers and gyroscopes. These devices' ubiquity, small size, and low power consumption make them ideal for use in systems such as CubeSats, micro aerial vehicles, autonomous underwater vehicles, and micro-robots operating in radiation environments. Radiation's interaction with materials manifests as atomic displacement and ionization, resulting in mechanical and electronic property changes, photocurrents, and charge buildup. This study examines silicon (Si) ion irradiation's interaction with piezoelectrically transduced MEMS resonators. Furthermore, the effect of adding a dielectric silicon oxide (SiO2) thin film is …

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Hydroxyapatite-Based Coatings On Silicon Wafers And Printed Zirconia, Antoine Chauvin Nov 2023

Hydroxyapatite-Based Coatings On Silicon Wafers And Printed Zirconia, Antoine Chauvin

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Dental surgery needs a naturally attract implant design that can ensure both osseointegration and soft tissue integration. Hydroxyapatite (HAp), the main mineral constituent of dentine and tooth enamel, is commonly used as a coating component, notably for overlaying titanium– or ceramics–based implants. This thesis aims to investigate the behavior of a HAp-based coating, specifically designed to be compatible with a porous substrate. Coating layers are made by sol–gel dip coating by immersion of porous substrates made by additive manufacturing into solutions of HAp, having been mixed with polyethyleneimine (PEI), to improve the adhesion of HAp on the substrate. First, the …

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Digital Twins Of The Living Knee: From Measurements To Model, Thor Erik Andreassen Nov 2023

Digital Twins Of The Living Knee: From Measurements To Model, Thor Erik Andreassen

Electronic Theses and Dissertations

Modern medicine has dramatically improved the lives of many. In orthopaedics, robotic surgery has given clinicians superior accuracy when performing interventions over conventional methods. Nevertheless, while these and many other methods are available to ensure treatments are performed successfully, far fewer methods exist to predict the proper treatment option for a given person. Clinicians are forced to categorize individuals, choosing the best treatment on “average.” However, many individuals differ significantly from the “average” person, for which many of these treatments are designed. Going forward, a method of testing, evaluating, and predicting different treatment options' short- and long-term effects on an …

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Quantitative, Photocurrent Multidimensional Coherent Spectroscopy, Adam Halaoui Nov 2023

Quantitative, Photocurrent Multidimensional Coherent Spectroscopy, Adam Halaoui

Electronic Theses and Dissertations

Multidimensional coherent spectroscopy (MDCS) is a quickly growing field that has a lot of advantages over more conventional forms of spectroscopy. These advantages all come from the fact that MDCS allows us to get time resolved correlated emission and absorption spectra using very precisely chosen interactions between the density matrix and the excitation laser. MDCS spectra gives the researcher a lot of information that can be extracted purely through qualitative analysis. This is possible because state couplings are entirely separated on the spectra, and once we know how to read the data, we can see how carriers transport in the …

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Interaction Of ΒL- And Γ-Crystallin With Phospholipid Membrane Using Atomic Force Microscopy, Nawal K. Khadka, Preston Hazen, Dieter Haemmerle, Laxman Mainali Nov 2023

Interaction Of ΒL- And Γ-Crystallin With Phospholipid Membrane Using Atomic Force Microscopy, Nawal K. Khadka, Preston Hazen, Dieter Haemmerle, Laxman Mainali

Physics Faculty Publications and Presentations

Highly concentrated lens proteins, mostly β- and γ-crystallin, are responsible for maintaining the structure and refractivity of the eye lens. However, with aging and cataract formation, β- and γ-crystallin are associated with the lens membrane or other lens proteins forming high-molecular-weight proteins, which further associate with the lens membrane, leading to light scattering and cataract development. The mechanism by which β- and γ-crystallin are associated with the lens membrane is unknown. This work aims to study the interaction of β- and γ-crystallin with the phospholipid membrane with and without cholesterol (Chol) with the overall goal of understanding the role of …

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Quantum Criticality At Cryogenic Melting Of Polar Bubble Lattices, Wei Luo, Alireza Akbarzadeh, Yousra Nahas, Sergei Prokhorenko, Laurent Bellaiche Nov 2023

Quantum Criticality At Cryogenic Melting Of Polar Bubble Lattices, Wei Luo, Alireza Akbarzadeh, Yousra Nahas, Sergei Prokhorenko, Laurent Bellaiche

Physics Faculty Publications and Presentations

Quantum fluctuations (QFs) caused by zero-point phonon vibrations (ZPPVs) are known to prevent the occurrence of polar phases in bulk incipient ferroelectrics down to 0 K. On the other hand, little is known about the effects of QFs on the recently discovered topological patterns in ferroelectric nanostructures. Here, by using an atomistic effective Hamiltonian within classical Monte Carlo (CMC) and path integral quantum Monte Carlo (PI-QMC), we unveil how QFs affect the topology of several dipolar phases in ultrathin Pb(Zr0.4Ti0.6)O3 (PZT) films. In particular, our PI-QMC simulations show that the ZPPVs do not suppress polar …

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Extended Planar Defects Of Oxygen Vacancies In Ferroelectric Batio3 And Impact On Ferroelectricity, Shaohui Qiu, Huaxiang Fu Nov 2023

Extended Planar Defects Of Oxygen Vacancies In Ferroelectric Batio3 And Impact On Ferroelectricity, Shaohui Qiu, Huaxiang Fu

Physics Faculty Publications and Presentations

Extended defects of vacancies in ferroelectrics (FE), where vacancies spread over an extended space, are of critical importance in terms of understanding the long-standing problems such as polarization fatigue and aging. However, extended defects in FEs are poorly understood. Here we investigate the extended planar oxygen vacancies in ferroelectric BaTiO3 using density functional theory and the modern theory of polarization. Oxygen vacancies of different charge states, namely V 2+O , V 1+O , and V 0O , are studied. We obtain interesting results such as: (i) The formation energy of planar V 2+O vacancies can …

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