Digital Commons Network^™

Toward Transformable Photonics: Reversible Deforming Soft Cavities, Controlling Their Resonance Split And Directional Emission, Mark Douvidzon, Shai Maayani, Harel Nagar, Tamir Admon, Vladimir Shuvayev, Lan Yang, Lev Deych, Yael Roichman, Tal Carmon

Publications and Research

We report on reversible and continuously deformable soft micro-resonators and the control of their resonance split and directional emission. Assisted by computerized holographic-tweezers, functioning as an optical deformer of our device, we gradually deform the shape and change the functionality of a droplet whispering-gallery cavity. For example, we continuously deform hexagonal cavities to rectangular ones and demonstrate switching to directionally emitting mode-of-operation, or splitting a resonant mode to a 10-GHz separated doublet. A continuous trend of improving spatial light modulators and tweezers suggests that our method is scalable and can control the shape and functionality of many individual devices. We …

Topology And Megnetism In F-Electron Systems, Firoza Kabir

Electronic Theses and Dissertations, 2020-2023

Topological insulators are insulators in the bulk but permit spin-polarized electrons to flow on their surface. Till date, non-magnetic topological materials have been extensively studied. However, due to the complex symmetries of magnetic crystals as well as theoretical and experimental difficulties associated with modeling and measuring quantum magnets, only a few magnetic materials have been explored so far. Therefore, by utilizing angle-resolved photoemission spectroscopy (ARPES), along with first-principles calculations, and magneto-transport measurements, we have chosen one doped and four intrinsic magnetic materials to study the interplay between magnetic order and nontrivial topology. First, we have observed a single topological non-trivial …

A Detailed X-Ray Analysis Of The Cold Front In Relics Cluster A2163, Anne Poy

CMC Senior Theses

Galaxy clusters are the largest gravitationally bound objects in the Universe. Studying them can teach us about how they merge and grow, which in turn provides unparalleled information about the history of the evolution of the Universe. X-ray observations of galaxy clusters have uncovered substructure in the hot, X-ray emitting gas known as the intracluster mediums (ICM). Substructure indicates that the ICM has been churned up, possibly by a significant off-axis merger event. This substructure includes cold fronts, sloshing spirals, and shocks. We present deep Chandra observations of the merging cluster Abell 2163. We investigate the global spectrum and find …

Electroosmotic Flow Of Viscoelastic Fluid Through A Constriction Microchannel, Jianyu Ji, Shizhi Qian, Zhaohui Liu

Mechanical & Aerospace Engineering Faculty Publications

Electroosmotic flow (EOF) has been widely used in various biochemical microfluidic applications, many of which use viscoelastic non-Newtonian fluid. This study numerically investigates the EOF of viscoelastic fluid through a 10:1 constriction microfluidic channel connecting two reservoirs on either side. The flow is modelled by the Oldroyd-B (OB) model coupled with the Poisson–Boltzmann model. EOF of polyacrylamide (PAA) solution is studied as a function of the PAA concentration and the applied electric field. In contrast to steady EOF of Newtonian fluid, the EOF of PAA solution becomes unstable when the applied electric field (PAA concentration) exceeds a critical value for …

Molecular Spectroscopy For Innovative Physics: Alcl & Baf, Alex Preston

Pomona Senior Theses

This thesis is inspired by recent developments in the realm of fundamental physics. Spectroscopic studies on diatomic molecules are at the forefront of such endeavors. High-precision microwave spectroscopy probing the rotational energy level transitions of the molecules AlCl and BaF are analyzed at length in this work. The frequency data for these molecules are evaluated using the programs SPFIT and SPCAT in order to develop a “global fit” numerical model of the rotational, vibrational, nuclear, and hyperfine parameters characterizing the systems. Born-Oppenheimer breakdown terms used to amend inconsistencies in the spectral coefficients are determined for both systems. Previously published data …

Understanding The Effects Of Water Vapor And Temperature On Aerosol Using Novel Measurement Methods, Tyler Jacob Capek

Dissertations, Master's Theses and Master's Reports

Aerosol and water are inexorably linked, and both are ubiquitous within our atmosphere and required components for cloud formation. Relative humidity (RH), a temperature dependent quantity, can have a significant influence on the size, shape, and ultimately, the optical properties of the aerosol. RH can vary substantially on small spatial and short temporal scales in turbulent conditions due to rapid fluctuations in temperature and water vapor mixing ratio. Accurate assessment of optical enhancements due to an increase in RH is key for determining the particles’ impact on the climate and visibility.

A humidity-controlled cavity attenuated phase-shift albedometer (H-CAPS-PM_SSA) …

Improving The Temporal Accuracy Of Turbulence Models And Resolving The Implementation Issues Of Fluid Flow Modeling, Kyle J. Schwiebert

Dissertations, Master's Theses and Master's Reports

A sizeable proportion of the work in this thesis focuses on a new turbulence model, dubbed ADC (the approximate deconvolution model with defect correction). The ADC is improved upon using spectral deferred correction, a means of constructing a higher order ODE solver. Since both the ADC and SDC are based on a predictor-corrector approach, SDC is incorporated with essentially no additional computational cost. We will show theoretically and using numerical tests that the new scheme is indeed higher order in time than the original, and that the benefits of defect correction, on which the ADC is based, are preserved.

The …

Five-Wave Resonances In Deep Water Gravity Waves: Integrability, Numerical Simulations And Experiments, Dan Lucas, Marc Perlin, Dian-Yong Liu, Shane Walsh, Rossen Ivanov, Miguel D. Bustamante

Articles

In this work we consider the problem of finding the simplest arrangement of resonant deep water gravity waves in one-dimensional propagation, from three perspectives: Theoretical, numerical and experimental. Theoretically this requires using a normal-form Hamiltonian that focuses on 5-wave resonances. The simplest arrangement is based on a triad of wave vectors K₁ + K₂ = K₃ (satisfying specific ratios) along with their negatives, corresponding to a scenario of encountering wave packets, amenable to experiments and numerical simulations. The normal-form equations for these encountering waves in resonance are shown to be non-integrable, but they admit an integrable reduction …

A Computational Study Of Properties Of Core-Shell Nanowire Heterostructures Using Density Functional Theory, Sandip Aryal

Dissertations, Master's Theses and Master's Reports

Nanoscale systems, especially the one-dimensional semiconducting nanowires, have been the subject of immense research interests due to their potential applications in nanoelectronics and optoelectronics that demand cheaper, smaller, faster, and energy-efficient components. In particular, the core/shell nanostructures, in which the core materials are shielded by materials with larger bandgap called shell, have been shown to enhance the performance of field effect transistors (FETs), solar cells, light emitting diodes (LEDs), and thermoelectric devices due to their outstanding features like valence band offset between the core and shell, higher stability against oxidation, reduction in the surface trap states, diminished nonradiative recombination processes, …

Computationally Recovering Preferred Factorizations Of Quantum Hilbert Space, Louisa Cornelis

Scripps Senior Theses

This thesis addresses the question of the preferred factorization of the quantum mechanical Hilbert Space into sub parts. Specifically, I computationally implement streamlined aspects of the recent “in principle” proposal of Carroll and Singh in their paper Quantum Mereology: Factorizing Hilbert Space into Subsystems with Quasi-Classical Dynamics. The goal is to link the selection of a preferred tensor product factorization to the appearance of quasi-classical behavior in this preferred factorization. Carroll and Singh quantify quasi-classical behavior through the criteria of “robustness” and “predictability” using the purity and pointer entropies. This work tests whether it is necessary to use both entropies …

Quantum Computing For The Quantum Curious, Ciaran Hughes, Joshua Isaacson, Anastasia Perry, Ranbel F. Sun, Jessica Turner

Open Access Books and Manuals

This open access book makes quantum computing more accessible than ever before. A fast-growing field at the intersection of physics and computer science, quantum computing promises to have revolutionary capabilities far surpassing “classical” computation. Getting a grip on the science behind the hype can be tough: at its heart lies quantum mechanics, whose enigmatic concepts can be imposing for the novice.

This classroom-tested textbook uses simple language, minimal math, and plenty of examples to explain the three key principles behind quantum computers: superposition, quantum measurement, and entanglement. It then goes on to explain how this quantum world opens up a …

Evaluation Of Postoperative Refractive Error Correction After Cataract Surgery, Ellen Konadu Antwi-Adjei, Emmanuel Owusu, Emmanuel Kobia-Acquah, Emmanuella Esi Dadzie, Emmanuel Anarfi, Seth Wanye

Articles

Suboptimal cataract surgery outcomes remain a challenge in most developing countries. In Ghana, about 2 million people have been reported to be blind due to cataract with about 20% new cases being recorded yearly. The aim of this study was to evaluate postoperative correction of refractive errors after cataract surgery in a selected eye hospital in Ashanti Region, Ghana. This was a retrospective study where medical records of patients (aged 40–100) who reported to an eye hospital in Ghana from 2013–2018 were reviewed. Included in the study were patients aged ≥40 years and patients with complete records. Data on patient …

Search For Cpt And Lorentz Invariance Violation In The Muon G-2 Experiment At Fermilab, Meghna Bhattacharya

Electronic Theses and Dissertations

The Muon g-2 experiment at Fermilab (E989) aims to measure the anomalous magnetic moment of the muon, $a_{\mu}= (g-2)/2$, to a groundbreaking precision of $140$ ppb, obtaining a near four-fold increase in precision over the previous experiment, E821, at the Brookhaven National Laboratory (BNL). The value of $a_{\mu}$ from BNL currently differs from the Standard Model prediction by $\sim 3.7$ standard deviations, suggesting the potential for new physics and therefore, motivating a new experiment.Because the theory predicts this number with high precision, testing the g-factor through experiment provides a stringent test of the SM and can suggest physics beyond the …

Multiscale Investigation Of Dropwise Condensation On A Smooth Hydrophilic Surface, Shahab Bayani Ahangar

Dissertations, Master's Theses and Master's Reports

The objective of this work is to identify the fundamental mechanism of dropwise condensation on a smooth solid surface by probing the solid-vapor interface during phase-change to evaluate the existence and structure of the thin film and the initial nucleus that develop during condensation. In this work, an automated Surface Plasmon Resonance imaging (SPRi) instrument with the ability to perform imaging in intensity modulation and angular modulation is developed. The SPRi instrument is used to probe (in three dimensions) the adsorbed film that forms on the substrate during dropwise condensation. SPRi with a lateral resolution of ~ 4-10 μm, thickness …

Advanced Raman Spectroscopy Detection Of Oxidative Damage In Nucleic Acid Bases: Probing Chemical Changes And Intermolecular Interactions In Guanosine At Ultralow Concentration, Francesca Ripanti, Claudia Fasolato, Flavia Mazzarda, Simonetta Palleschi, Marina Ceccarini, Chunchun Li, Margherita Bignami, Enrico Bodo, Steven E.J. Bell, Filomena Mazzei, Paolo Postorino

Bioelectrics Publications

DNA/RNA synthesis precursors are especially vulnerable to damage induced by reactive oxygen species occurring following oxidative stress. Guanosine triphosphates are the prevalent oxidized nucleotides, which can be misincorporated during replication, leading to mutations and cell death. Here, we present a novel method based on micro-Raman spectroscopy, combined with ab initio calculations, for the identification, detection, and quantification of oxidized nucleotides at low concentration. We also show that the Raman signature in the terahertz spectral range (<100 >cm(-1)) contains information on the intermolecular assembly of guanine in tetrads, which allows us to further boost the oxidative damage detection limit. Eventually, we …

Developing A Music Composition Practice: Exploring The Choreography Of Cymatics, Joshua Jervis

Theses : Honours

Cymatics is an area of physics popularised by Hans Jenny that observes the influence of sound but more simply vibration on physical matter. When sound is directly applied to a substance, for example, water, the vibrations create kaleidoscopic movement within the medium. Specific variables primarily of pitch, container size, and water volume contribute to creating a variety of geometric shapes. Without sound cymatics does not exist and is, therefore, a visual characteristic of sound itself.

With an investigation into the behaviour and application of cymatics, this research uses the findings of an investigation to develop a ‘choreographical’ language that can …

Topic Modeling And Cultural Nature Of Citations, Marie Coraline Dumaz

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ever since the beginning of research journals, the number of academic publications has been increasing steadily. Nowadays, especially, with the new importance of online open-access journals and databases, research papers are more easily available to read and share. It also becomes harder to keep up with novelties and grasp an idea of the general impact of a given researcher, institution, journal, or field. For this reason, different bibliometric indicators are now routinely used to classify and evaluate the impact or significance of individual researchers, conferences, journals, or entire scientific communities. In this thesis, we provide tools to study trends in …

Estimating The Azimuthal Mode Structure Of Ultra Low Frequency Waves And Its Effects On The Radial Diffusion Of Radiation Belt Electrons, Mohammad Barani

Graduate Theses, Dissertations, and Problem Reports (ETD)

Characterizing the azimuthal mode number �� of Ultra Low Frequency (ULF) waves is critical to quantifying the radial diffusion of radiation belt electrons. A Wavelet cross-spectral technique is applied to the compressional ULF waves observed by multiple pairs of GOES and MMS satellites to estimate the mode structure of ULF waves. A more realistic distribution of mode numbers is achieved by inclusion of the modes corresponding to different wave propagation directions as well as at �� higher than fundamental mode number. For the event study of a geomagnetic storm using GOES data, ULF wave power is found to dominate at …

Majorana Nanostructures And Their Electrostatic Environment, Benjamin David Woods

Graduate Theses, Dissertations, and Problem Reports (ETD)

Majorana zero modes (MZMs) are zero-energy excitations emerging in one- and two-dimensional topological superconductors. These exotic modes have attracted much attention in the last decade due to their topological protection and non-Abelian statistics, which make them possible building blocks for topological quantum computation. In particular, semiconductor-superconductor (SM-SC) nanostructures have attracted the most attention with several measurements being consistent with the presence of MZMs. Debate continues, however, whether MZMs or topologically-trivial Andreev bound states are responsible for such measurements.

In order to interpret experimental results distinguishing MZMs from Andreev bound states and gain a better understanding of what conditions need to …

Semi-Inclusive Deep Inelastic Scattering Measurements Of A = 3 Nuclei With Clas12 In Hall B, S. Li, R. Cruz Torres, J. Rittenhouse West, F. Yuan, A. Denniston, O. Hen, J. Kahlbow, T. Kutz, J. R. Pybus, E. P. Segarra, C. Ayerbe-Gayoso, H. Bhatt, D. Bhetuwal, T. Chetry, B. Devkota, J. Dunne, D. Dutta, L. El Fassi, T. Gaballah, A. Karki, M. Amarian, C. Fogler, F. Hauenstein, C. Hyde, G. Gavalian, L. B. Weinstein, D. Gaskell, D. W. Higinbotham, C. Keith, C. Keppel, J. Maxwell, A. Tadepalli, D. Meekins, D. Nguyen, S. Stepanyan, H. Szumila-Vance, Z. G. Xiao, Y. Wang, Z. H. Ye, Y. P. Zhang, K. Griffioen, P. Bosted, A. Bianconi, G. Costantini, M. Leali, S. Migliorati, L. Venturelli, V. Mascagna, A Boyer, F. Benmokhtar, A. Gadsby, A. Parker, L. Baashen, B. Raue, W. J. Briscoe, S. Ratliff, A. Schmidt, E. Seroka, P. Sharp, P. G. Solazzo, I. I. Strakovsky, K. Adhikari, G. Niculescu, K.-T. Brinkmann, S. Diehl, A. Kripko, Sheren Alsalmi, Tyler J. Hague, A. Beck, S. Beck, E. Cohen, I. Korover, G. Johansson, C. Neuburger, E. Piasetzky, Michael Nycz, R. Capobianco, T. Haywars, F.-X. Girod, K. Joo, A. Kim, V. Klimenko, R. Santos, U. Shrestha, P. Simmerling, J. Richard, N. Trotta, B. Mckinnon, W. Brooks

Physics Faculty Publications

We propose to measure precision ratios of charged pion electroproduction in Semi-Inclusive Deep Inelastic Scattering from ²D, ³He and ³H targets to test the flavor dependence of the EMC effect in the valence quark region. This trio of targets has been chosen to minimize hadron attenuation effects while maximizing nuclear asymmetry. The standard configuration CLAS12 detector will be used in the experiment to detect scattered electrons and knocked-out pions. A new, dedicated, tritium target that will be developed for the approved quasi-elastic experiment, E12-20-005 [1], will be used. The experiment will measure semi-inclusive production of charged pions over a wide …

Photoluminescence Properties Of Novel Iii-V Semiconductor Systems, Shumithira Gandan

Theses

Perturbation of the inherent radiation equilibrium in solids by an external energy could engender an emission of the superfluous energy as electromagnetic radiation, or luminescence. Photoluminescence methods precipitate this disintegration of radiation equilibrium often by supplying the external energy as photons with energies higher than the bandgap energy of the solid. Since the excitation energy momentarily transforms the medium before luminescence is emitted, photoluminescence experiments are able to produce diverse and intricate spectroscopic data detailing the optical properties of the solid as a measure of this transformation. The pliability of allowed electron states in semiconductors have instigated bourgeoning research in …

Biophysical Analysis Of The Structure And Aggregation Of Amyloid Beta Peptide, Faisal Abedin

Electronic Theses and Dissertations, 2020-2023

Alzheimer's disease (AD) is the major cause of dementia and is characterized by neuronal death and brain atrophy. The amyloid ß (Aß) peptide is tightly associated with neuronal dysfunction during AD, but the molecular mechanism underlying the neurotoxic effect of Aß is poorly understood. Extracellular fibrillar deposits (plaques) of Aß were initially believed to be the cause of AD, but currently there is overwhelming evidence that the prefibrillar Aß oligomers are the major toxic entities. Structural characterization of Aß oligomers and fibrils is important for understanding the structural features determining the toxic potency of the peptide. This project has studied …

$\Lambda_C \To \Lambda$ Form Factors In Lattice Qcd, Hüseyi̇n Bahti̇yar

Turkish Journal of Physics

Studying the semileptonic decays of charmed particles is prominent in testing the standard model of particle physics. Motivated by recent experimental progress in weak decays of the charm baryon sector, we study the form factors of $\Lambda_c \to \Lambda \ell^+ \nu$ transition on two flavor lattices. We compute two- and three-point functions, extract the dimensionless projected correlators, and combine them to form the Weinberg form factors. In the zero transferred momentum limit $f_1$, $f_2$ and $g_1$ form factors are found to be in agreement with other models, furthermore $f_3$ and $g_3$ form factors are comparable to model determinations. The $g_2$ …

Combined Experimental And Modeling Analysis For Thedevelopment Of Optical Materials Suitable To Enhance Theimplementation Of Plasmonic-Enhanced Luminescent Down-Shifting Solutions On Existing Silicon-Based Photovoltaic Devices, James Walshe, Mihaela Girtan, Sarah Mccormack, John Doran, George Amarandei

Articles

The development of highly efficient solar collectors requires modulating the light interactions with the semiconducting materials. Incorporating luminescent species and metal nanoparticles within a semitransparent polymeric material (e.g., polymethyl methacrylate (PMMA)) leads to the formation of a plasmon-enhanced luminescent down-shifting (PLDS) layer, which offers a retrofittable approach toward expanding the wavelength range over which the conversion process can effectively occur. Adding antireflection coatings (ARCs) further controls the spectral response. However, with each additional component comes additional loss pathways. In this study, the losses related to light interactions with the PMMA and the ARCs have been investigated theoretically using a transfer …

Power Amplification Strategies Across Animals, Rayhan Asif

Williams Honors College, Honors Research Projects

Animals use muscles for movement, but some have evolved mechanisms to exceed maximum power used in a motion known as power amplification. In this literature review, I analyzed and compared the evolution of structures capable of power amplification between species. Structures capable of power amplification were broken down into the basic components of the engine, amplifier, and tool. The species analyzed were found to possess necessary structures for power amplification which were relatively similar to each other in morphology, but varied greatly in function. The ease with which these structures evolved was evaluated based on the amount of divergence which …

Understanding The Research And Applications Of Quantum Computing, Joshua Foss

Williams Honors College, Honors Research Projects

In-Depth research of current quantum computing understanding and practices. Presentation of possible new and creative applications of quantum computing.

Investigation Of Ions Accelerated Through Electrostatic Menisci In An Inductively Coupled Plasma, David D. Caron

Graduate Theses, Dissertations, and Problem Reports (ETD)

Plasmas are used in semiconductor fabrication as they allow for very precise control over processes such as etching and doping. This is achieved by extracting a beam of ions from the plasma to interact with and modify the surface of a silicon wafer. However, conventional fabrication methods are reaching spatial limitations as semiconductor features reach the atomic scale. Therefore, in order to better control the fabrication processes and facilitate the transition to three-dimensional architecture, a greater understanding of ion beam formation is needed. Ion beams are extracted at the boundary between the Debye sheath and an externally applied potential, which …

Development Of Synthetic Coal Char Simulant For Microwave Conversion Studies: A Computationally-Driven Approach, Kevin A. Hager

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recent experimental demonstration of new reaction windows for coal char/methane reactions that are less energy-intensive, provides innovation for modular reactors. However, the correlation of the exact mechanism for the enhancement of these reaction windows is not certain. This study investigates the simplification of these experimental studies by developing a well-characterized coal char simulant. The approach involves using a computational approach to screen macroscopic composition to replicate the dielectric and compositional response of actual char. This study is focused on PRB coal char. A discrete element method (DEM) technique was used to simulate the packing of coal chars to give the …

Magnetic Properties Of Lsmo/Sto Thin Films: Magnetocaloric, Spin Dynamics And Magnetic Viscosity Investigations, Navid Mottaghi

Graduate Theses, Dissertations, and Problem Reports (ETD)

While other films are discussed, this dissertation will focus on detailed studies of the dc and ac bulk magnetometry in a characteristic 7.6 nm thin film of La_0.7Sr_0.3MnO₃ grown on SrTiO₃ (001). The dc bulk magnetometry measurements show that the sample is magnetically inhomogeneous. Temperature variation of magnetization (M vs. T) was measured in zero-field-cooled and field-cooled protocols to determine the blocking temperature T_B in different applied magnetic fields. The field variation of T_B is interpreted as the presence of embedded spin clusters of 1.4 nm. Moreover, the M vs. …

Color Charge Correlations In The Proton At Nlo: Beyond Geometry Based Intuition, Adrian Dumitru, Heikki Mäntysaari, Risto Paatelainen

Publications and Research

Color charge correlators provide fundamental information about the proton structure. In this Letter, we evaluate numerically two-point color charge correlations in a proton on the light cone including the next-to-leading order corrections due to emission or exchange of a perturbative gluon. The non-perturbative valence quark structure of the proton is modelled in a way consistent with high-x proton structure data. Our results show that the correlator exhibits startlingly non-trivial behavior at large momentum transfer or central impact parameters, and that the color charge correlation depends not only on the impact parameter but also on the relative transverse momentum of …