Other Physics Commons^™

Evolution Of Network Architecture In A Granular Material Under Compression, Lia Papadopoulous, James G. Puckett, Karen E. Daniels, Danielle S. Bassett

Physics and Astronomy Faculty Publications

As a granular material is compressed, the particles and forces within the system arrange to form complex and heterogeneous collective structures. Force chains are a prime example of such structures, and are thought to constrain bulk properties such as mechanical stability and acoustic transmission. However, capturing and characterizing the evolving nature of the intrinsic inhomogeneity and mesoscale architecture of granular systems can be challenging. A growing body of work has shown that graph theoretic approaches may provide a useful foundation for tackling these problems. Here, we extend the current approaches by utilizing multilayer networks as a framework for directly quantifying …

Satellite-Beacon Ionospheric-Scintillation Global Model Of The Upper Atmosphere (Sigma) Ii: Inverse Modeling With High Latitude Observations To Deduce Irregularity Physics, K. B. Deshpande, G. S. Bust, C. R. Clauer, W. A. Scales, N. A. Frissell, J. M. Ruohoniemi, L. Spogli, C. Mitchell, Allan T. Weatherwax

Physics Faculty Publications

Ionospheric scintillation is caused by irregularities in the ionospheric electron density. The characterization of ionospheric irregularities is important to further our understanding of the underlying physics. Our goal is to characterize the intermediate (0.1–10 km) to medium (10–100 km) scale high-latitude irregularities which are likely to produce these scintillations. In this paper, we characterize irregularities observed by Global Navigation Satellite System (GNSS) during a geomagnetically active period on 9 March 2012. For this purpose, along with the measurements, we are using the recently developed model: “Satellite-beacon Ionospheric-scintillation Global Model of the upper Atmosphere” (SIGMA). The model is particularly applicable at …

A Clean Energy Utility For Multifamily Housing In A Deregulated Energy Market, Ata Raziei, Kevin P. Hallinan, Robert J. Brecha

Physics Faculty Publications

Energy efficiency and renewable energy (EERE) investment in multifamily residences in the United States has not kept pace with investment in resident-owned facilities. Split incentives, where owners cannot benefit economically from energy cost savings for residences and resident investment in EERE is not feasible, have posed a significant barrier. A clean energy utility is posited to circumvent this barrier. This utility would be responsible for power purchase from the grid, ideally as a real-time purchase agent from the grid manager; investment in energy efficiency and renewable energy; and demand management through control of water heating, as well as supply-side management …

Magnetism In Curved Geometries, Robert Streubel, Peter Fischer, Florian Kronast, Volodymyr P. Kravchuk, Denis D. Sheka, Yuri Gaididei, Oliver G. Schmidt, Denys Makarov

Robert Streubel Papers

Extending planar two-dimensional structures into the three-dimensional space has become a general trend in multiple disciplines, including electronics, photonics, plasmonics and magnetics. This approach provides means to modify conventional or to launch novel functionalities by tailoring the geometry of an object, e.g. its local curvature. In a generic electronic system, curvature results in the appearance of scalar and vector geometric potentials inducing anisotropic and chiral effects. In the specific case of magnetism, even in the simplest case of a curved anisotropic Heisenberg magnet, the curvilinear geometry manifests two exchange-driven interactions, namely effective anisotropy and antisymmetric exchange, i.e. Dzyaloshinskii-Moriya-like interaction. As …

3d Post-Stack Seismic Inversion Using Global Optimization Techniques: Gulf Of Mexico Example, Elijah A. Adedeji

LSU New Orleans Theses and Dissertations

Seismic inversion using a global optimization algorithm is a non-linear, model-driven process. It yields an optimal solution of the cost function – reflectivity/acoustic impedance, when prior information is sparse. The inversion result offers detailed interpretations of thin layers, internal stratigraphy, and lateral continuity and connectivity of sand bodies. This study compared two stable and robust global optimization techniques, Simulated Annealing (SA) and Basis Pursuit Inversion (BPI) as applied to post-stack seismic data from the Gulf of Mexico.

Both methods use different routines and constraints to search for the minimum error energy function. Estimation of inversion parameters in SA is rigorous …

Abstracts From The 2016 Ahac Conference, Erick Agrimson

2017 Academic High Altitude Conference

This is a listing of Abstracts from AHAC 2016

Chiral Light Intrinsically Couples To Extrinsic/Pseudo-Chiral Metasurfaces Made Of Tilted Gold Nanowires, Alessandro Belardini, Marco Centini, Grigore Leahu, David C. Hooper, Roberto Li Voti, Eugenio Fazio, Joseph W. Haus, Andrew Sarangan, Ventsislav K. Valev, Concita Sibilia

Electro-Optics and Photonics Faculty Publications

Extrinsic or pseudo-chiral (meta)surfaces have an achiral structure, yet they can give rise to circular dichroism when the experiment itself becomes chiral. Although these surfaces are known to yield differences in reflected and transmitted circularly polarized light, the exact mechanism of the interaction has never been directly demonstrated. Here we present a comprehensive linear and nonlinear optical investigation of a metasurface composed of tilted gold nanowires. In the linear regime, we directly demonstrate the selective absorption of circularly polarised light depending on the orientation of the metasurface. In the nonlinear regime, we demonstrate for the first time how second harmonic …

Ultracold Quantum Scattering In The Presence Of Synthetic Spin-Orbit Coupling, Su-Ju Wang

Open Access Dissertations

Two-body scattering constitutes one of the most fundamental processes in various physical systems ranging from ultracold dilute quantum gases to energetic quark- gluon plasmas. In this dissertation, we study the low-energy atomic collision physics in the presence of synthetic gauge fields, which are generated by atom-light interaction. One category of synthetic gauge fields is the artificial spin-orbit coupling. We discuss three different aspects in scattering theory: ultracold collision, scattering resonance, and bound state formation from a few-body perspective when the atomic spin states are coupled with their center-of-mass motion. The understanding of the spin-orbit effects on the modification of the …

Identifying Treatment Planning System Errors In Iroc-Houston Head And Neck Phantom Irradiations, James Kerns

Dissertations and Theses (Open Access)

Treatment Planning System (TPS) errors can affect large numbers of cancer patients receiving radiation therapy. Using an independent recalculation system, the Imaging and Radiation Oncology Core-Houston (IROC-H) can identify institutions that have not sufficiently modelled their linear accelerators in their TPS model. Linear accelerator point measurement data from IROC-H’s site visits was aggregated and analyzed from over 30 linear accelerator models. Dosimetrically similar models were combined to create “classes”. The class data was used to construct customized beam models in an independent treatment dose verification system (TVS). Approximately 200 head and neck phantom plans from 2012 to 2015 were recalculated …

Utilizing Computed To Mography Image Features To Advance Prediction Of Radiation Pneumonitis, Shane P. Krafft

Dissertations and Theses (Open Access)

Improving outcomes for non-small-cell lung cancer patients treated with radiation therapy (RT) requires optimizing the balance between local tumor control and risk of normal tissue toxicity. In approximately 20% of patients, severe acute symptomatic lung toxicity, termed radiation pneumonitis (RP), still occurs. Identifying the individuals at risk of RP prior to or early during treatment offers tremendous potential to improve RT by providing the physician with information to assist in making clinical decisions that enhance therapy. Our central goal for this work was to demonstrate the potential gain in predictive accuracy of normal tissue complication probability models for RP by …

Measurement Of The Electron Return Effect Using Presage Dosimeter, Gye Won Choi

Dissertations and Theses (Open Access)

MR-guided radiation therapy (MRgRT) provides benefits such as superior soft tissue contrast, no imaging dose, and functional imaging capacities, but it also has concerns to be addressed. The electron return effect (ERE) refers to dose enhancement at the interface between different media, caused when radiation is delivered in the magnetic field. The ERE poses clinical concerns in MRgRT because it significantly enhances the dose at interfaces, and the intensity and pattern of the dose enhancement depends on many factors. The ERE results in a complex pattern of dose enhancement over a three-dimensional (3D) volume around tissue interfaces inside the patient …

Spica: Stereographic Projection For Interactive Crystallographic Analysis, Xingzhong Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

In numerous research fields, especially the applications of electron and X-ray diffraction, stereographic projection represents a powerful tool for researchers. SPICA is a new computer program for stereographic projection in interactive crystallographic analysis, which inherits features from the previous JECP/SP and includes more functions for extensive crystallographic analysis. SPICA provides fully interactive options for users to plot stereograms of crystal directions and crystal planes, traces, and Kikuchi maps for an arbitrary crystal structure; it can be used to explore the orientation relationships between two crystalline phases with a composite stereogram; it is also used to predict the tilt angles of …

Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb

Electro-Optics and Photonics Faculty Publications

3-D holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3-D holographic ladar data for phase corrections across multiple temporal frequency samples. Substantial improvement of range compression is demonstrated with a laboratory experiment where our modified PGA technique is applied. Additionally, the PGA estimator is demonstrated to be …

Model For The Electrolysis Of Water And Its Use For Optimization, Roger Lascorz, Javier E. Hasbun Dr

Georgia Journal of Science

The goal of this research was to study the optimization of the electrolysis of water both theoretically and experimentally. For accuracy, 3 hr experiments were made with measurements recorded every 15 min. The results show that a better model than the classical one is needed for water electrolysis. A new model that fits experimental data better is proposed. The results of this new model not only predict hydrogen production in electrolysis of water better, but show a way to predict gas production of any liquid as well as what voltage to use to optimize it.

Thermal Vibration Of Magnetostrictive Functionally Graded Material Shells With The Transverse Shear Deformation Effects, C. C. Hong

Applications and Applied Mathematics: An International Journal (AAM)

The transverse shear deformation effect on the functionally graded material (FGM) circular cylindrical shells with mounted magnetostrictive layer under thermal vibration is investigated by using the generalized differential quadrature (GDQ) method. In the time dependent of displacement field, the first order shear deformation theory (FSDT) is used. The dynamic equilibrium differential equations with displacements and shear rotations of FGM shells under the magnetostrictive load and thermal load are normalized into the dynamic discrete equations. The computational solutions for thermal stresses and center deflections of magnetostrictive FGM circular cylindrical shells with four edges in simply supported boundary conditions are obtained. Some …

On The Global Existence And Boundedness Of Solutions Of Nonlinear Vector Differential Equations Of Third Order, Timur Ayhan, Cemil Tunç

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we give some criteria to ensure the global existence and boundedness of solutions to a kind of third order nonlinear vector differential equations. By using the Lyapunov's direct method, we obtain a new result on the topic and give an example for the illustrations. Our result includes, completes and improves some earlier results in the literature.

Bianchi Type-I Hyperbolic Models With Perfect Fluid And Dark Energy In Bimetric Theory Of Gravitation, M. S. Borkar, S. S. Charjan, V. V. Lepse

Applications and Applied Mathematics: An International Journal (AAM)

Three different Bianchi type-I cosmological models as related to perfect fluid, with quintessence and with Chaplygin gas, in bimetric theory of gravitation have been deduced. The perfect fluid model has hyperbolic geometry and all its physical parameters are also hyperbolic in nature and therefore they have been studied from hyperbolic geometric view point. All these models are isotropize and shear-less. Other geometrical and physical behaviors of the models have also been studied. The hyperbolic geometric view point of the models will be helpful to the people who use observational data to search for such type of geometry.

Lrs Bianchi Type-Ii Cosmological Model With String Bulk Viscous Fluid And Magnetic Field In Barber’S Second Self Creation Theory, M. S. Borkar, N. K. Ashtankar

Applications and Applied Mathematics: An International Journal (AAM)

We present a solution of LRS Bianchi type-II space-time with string viscous fluid and magnetic field by solving the Barber’s field equations of self-creation theory of gravitation and it is seen that Barber scalar function 𝜙 affects the other physical parameters of the model and contributes a very high matter density, with high particle density at early stage of the universe and also it contributes the negative role of bulk viscous fluid in the evolution. Other geometrical and physical aspects of the model are also studied.

Enhancement Of Heat Transfer In Elastico-Viscous Fluid Due To Nanoparticles, Where The Fluid Is Impinging Obliquely To The Stretchable Surface: A Numerical Study, Tariq Javed, Abuzar Ghaffari, Tasawar Hayat

Applications and Applied Mathematics: An International Journal (AAM)

This article addresses the two-dimensional oblique stagnation point flow of non-Newtonian fluid in the presence of nanoparticles. Constitutive equations of Walter-B fluid are employed in the mathematical development of the relevant problems. Mathematical formulation includes the Brownian motion and thermophoresis effects. The resulting nonlinear system of equations are analyzed through Chebyshev Spectral Newton Iterative Scheme (CSNIS). A comparative study of present results through tabular values has been made with the previous results in a limiting sense and an excellent agreement is noted. It is also found that in near stagnation point region, the heat transfer rate and mass diffusion flux …

Lrs Bianchi Type-I Cosmology With Gamma Law Eos In F(R; T) Gravity, Pratishtha Shukla, Amritha Jayadev

Applications and Applied Mathematics: An International Journal (AAM)

We have studied the locally rotationally symmetric (LRS) Bianchi type-I line element in f(R; T) (R is the Ricci scalar and T is the trace of the stress energy tensor) theory of gravity in presence of EoS parameter. The simplest case of f(R; T) gravity, i.e. first choice, is considered. The “gamma-law” equations of state are considered to explore the role of particle creation in the early universe. The exact solutions of the field equations are obtained using the scalar expansion proportional to the shear. The physical and kinematical properties of the model are studied.