Physical Sciences and Mathematics Commons^™

Lithological And Sequence Stratigraphic Examination Of The Madison Group Marker Beds, Eastern Williston Basin Margin, North Dakota, Troy Jd. Skitt

Theses and Dissertations

The Frobisher-Alida interval consists of eight log-defined subintervals or “beds” within the Mississippian upper Mission Canyon and lower Charles Formations of the Madison Group in the Williston Basin. The subintervals are composed of predominantly evaporite and carbonate lithologies, and include in descending order: 1) Midale, 2) Rival, 3) Bluell, 4) Sherwood, 5) Mohall, 6) Glenburn, 7) Wayne, and 8) Landa. The top of the lower six subintervals are separated by thin but areal extensive log-defined markers of contrasting lithologies and include in descending order: 1) State A, 2) Sherwood Argillaceous Marker (S.A.M.), 3) K-1, 4) K-2, 5) K-3, and 6) …

Self-Assembling Of Gold Nanoparticles Array For Electro-Sensing Applications, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

A colloidal solution of citrate-stabilized gold nanoparticles (AuNPs) with an average size of ca. 2.6 nm has been prepared, characterized and further implemented in electro-sensing applications. This colloidal solution of AuNPs has been prepared via the reduction of NaAuCl4 with sodium tetrahydroborate (NaBH4) using trisodium citrate as a stabilizer. The optical properties of this solution have been studied with UV–Vis spectroscopy. Next, these AuNPs have been immobilized onto a polycrystalline Au (poly-Au) electrode with the assistance of benzenedimethanethiol (BDMT), which served as a binder. Attention has been taken to ensure the formation of a compact impermeable layer of BDMT on …

Information And Communication Technology To Link Criminal Justice Reentrants To Hiv Care In The Community, Ann Kurth, Irene Kuo, James Peterson, Nkiru Azikiwe, Lauri Bazerman, Alice Cates, Curt G. Beckwith

Epidemiology Faculty Publications

The United States has the world’s highest prison population, and an estimated one in seven HIV-positive persons in the USA passes through a correctional facility annually. Given this, it is critical to develop innovative and effective approaches to support HIV treatment and retention in care among HIV-positive individuals involved in the criminal justice (CJ) system. Information and communication technologies (ICTs), including mobile health (mHealth) interventions, may offer one component of a successful strategy for linkage/retention in care. We describe CARE+ Corrections, a randomized controlled trial (RCT) study now underway in Washington, that will evaluate the combined effect of computerized motivational …

Transmission Potential Of Influenza A/H7n9, February To May 2013, China, Gerardo Chowell, Lone Simonsen, Sherry Towers, Mark A. Miller, Cecile G. Viboud

Epidemiology Faculty Publications

Background

On 31 March 2013, the first human infections with the novel influenza A/H7N9 virus were reported in Eastern China. The outbreak expanded rapidly in geographic scope and size, with a total of 132 laboratory-confirmed cases reported by 3 June 2013, in 10 Chinese provinces and Taiwan. The incidence of A/H7N9 cases has stalled in recent weeks, presumably as a consequence of live bird market closures in the most heavily affected areas. Here we compare the transmission potential of influenza A/H7N9 with that of other emerging pathogens and evaluate the impact of intervention measures in an effort to guide pandemic …

Innovative Applications Of Genetic Algorithms To Problems In Accelerator Physics, Alicia Hofler, Balša Terzić, Matthew Kramer, Anton Zvezdin, Vasiliy Morozov, Yves Roblin, Fanglei Lin, Colin Jarvis

Physics Faculty Publications

The genetic algorithm (GA) is a powerful technique that implements the principles nature uses in biological evolution to optimize a multidimensional nonlinear problem. The GA works especially well for problems with a large number of local extrema, where traditional methods (such as conjugate gradient, steepest descent, and others) fail or, at best, underperform. The field of accelerator physics, among others, abounds with problems which lend themselves to optimization via GAs. In this paper, we report on the successful application of GAs in several problems related to the existing Continuous Electron Beam Accelerator Facility nuclear physics machine, the proposed Medium-energy Electron-Ion …

Cryogenic Test Of A Proof-Of-Principle Superconducting Rf-Dipole Deflecting And Crabbing Cavity, S. U. De Silva, Jean R. Delayen

Physics Faculty Publications

Recent applications in need of compact low-frequency deflecting and crabbing cavities have initiated the design and development of new superconducting structures operating at high gradients with low losses. Previously, TM₁₁₀-type deflecting and crabbing cavities were developed and have also been operated successfully. However, these geometries are not favorable designs for low operating frequencies. The superconducting rf-dipole cavity is the first compact deflecting and crabbing geometry that has demonstrated high gradients and high shunt impedance. Since the fundamental operating mode is the lowest mode and is widely separated from the nearest higher order mode, the rf-dipole design is an …

Single Spin Asymmetry An In Polarized Proton–Proton Elastic Scattering At √S = 200 Gev, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, S. Bültmann, I. Koralt, D. Plyku

Physics Faculty Publications

We report a high precision measurement of the transverse single spin asymmetry A_N at the center of mass energy √s = 200 GeV in elastic proton–proton scattering by the STAR experiment at RHIC. The A_N was measured in the four-momentum transfer squared t range 0.003 ⩽ | t | ⩽ 0.035 ( GeV / c ) ² , the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of A_N and its t-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the …

Beam Asymmetry Σ For Π+ And Π0 Photoproduction On The Proton For Photon Energies From 1.102 To 1.862 Gev, K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. S. Nepali, Y. Prok, Clas Collaboration

Physics Faculty Publications

Beam asymmetries for the reactions ˠp -> pπ⁰ and ˠp -> nπ⁺have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged, linearly polarized photon beam with energies from 1.102-1.862 GeV. A Fourier moment technique for extracting beam asymmetries from experimental data is described. The results reported here possess greater precision and finer energy resolution than previous measurements. Our data for both pion reactions appear to favor the SAID and Bonn-Gatchina scattering analyses over the older Mainz MAID predictions. After incorporating the present set of beam asymmetries into the world database, exploratory fits made with …

Cross Sections For The Ɣp → K*+Ʌ And Ɣp → K*+Σº Reactions Measured At Clas, K.P. Adhikari, M. J. Amaryan, C. E. Hyde, S. Koirala, M. Mayer, Clas Collaboration

Physics Faculty Publications

The first high-statistics cross sections for the reactions ɣp → K*+Ʌ and ɣp → K*+Σº were measured using the CLAS detector at photon energies between threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. Differential cross sections are presented over the full range of the center-of-mass angles, and then fitted to Legendre polynomials to extract the total cross section. Results for the K*+Ʌ final state are compared with two different calculations in an isobar and a Regge model, respectively. Theoretical calculations significantly underestimate the K*+Ʌ total cross sections between 2.1 and 2.6 GeV, but are in better agreement …

Design Evolution And Properties Of Superconducting Parallel-Bar Rf-Dipole Detecting And Crabbing Cavities, S. U. De Silva, J. R. Delayen

Physics Faculty Publications

Deflecting/crabbing cavities serve a variety of purposes in different accelerator applications, primarily in separating a single beam into multiple beams and in rotating bunches for head-on collisions at the interaction point in particle colliders. Deflecting/crabbing cavities are also used for transverse and longitudinal emittance exchange in beams, x-ray pulse compression, and for beam diagnostics. Compact superconducting deflecting/crabbing cavities are under development due to strict dimensional constraints and requirements for higher field gradients with low surface losses. The TEM-like superconducting parallel-bar cavity supports low operating frequencies, thus making the design favorable for many of the deflecting/crabbing cavity applications. The design of …

Experimental Studies Of Di-Jets In Au + Au Collisions Using Angular Correlations With Respect To Back-To-Back Leading Hadrons, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Koralt, Star Collaboration

Physics Faculty Publications

Jet-medium interactions are studied via a multihadron correlation technique ( called "2 + 1"), where a pair of back-to-back hadron triggers with large transverse momentum is used as a proxy for a di-jet. This work extends the previous analysis for nearly symmetric trigger pairs with the highest momentum threshold of trigger hadron of 5 GeV/c with the new calorimeter-based triggers with energy thresholds of up to 10 GeV and above. The distributions of associated hadrons are studied in terms of correlation shapes and per-trigger yields on each trigger side. In contrast with di-hadron correlation results with single triggers, the associated …

Elliptic Flow Of Identified Hadrons In Au + Au Collisions At √ˢᴺᴺ = 7.7- 62.4 Gev, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, S. Bültmann, Star Collaboration

Physics Faculty Publications

Measurements of the elliptic flow, υ₂, of identified hadrons (π^±, , K^±, , K^O_s, p, p¯, ɸ, Λ, Λ¯, Ξ-, Ξ¯+, Ω-, Ω¯+ in Au + Au collisions at √ˢᴺᴺ = 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV are presented. The measurements were done at midrapidity using the time-projection chamber and the time-of-flight detectors of the Solenoidal Tracker at RHIC experiment during the beam-energy scan program at Relativistic Heavy Ion Collider. A significant difference in the υ₂ values for particles and the corresponding antiparticles was observed at all transverse momenta for …

Multipole Field Effects For The Superconducting Parallel-Bar/Rf-Dipole Deflecting/Crabbing Cavities, S. U. De Silva, J. R. Delayen

Physics Faculty Publications

The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

Geometry Effects On Multipole Components And Beam Optics In High-Velocity Multi-Spoke Cavities, C. S. Hopper, K. Deitrick, J. R. Delayen

Physics Faculty Publications

Velocity-of-light, multi-spoke cavities are being proposed to accelerate electrons in a compact light-source [1]. There are strict requirements on the beam quality which require that the linac have only small non-uniformities in the accelerating field. Beam dynamics simulations have uncovered varying levels of focusing and defocusing in the proposed cavities, which is dependent on the geometry of the spoke in the vicinity of the beam path. Here we present results for the influence different spoke geometries have on the multipole components of the accelerating field and how these components, in turn, impact the simulated beam properties.

Mechanical Analysis Of The 400 Mhz Rf-Dipole Crabbing Cavity Prototype For Lhc High Luminosity Upgrade, S. U. De Silva, H. Park, J. R. Delayen, Z. Li

Physics Faculty Publications

The proposed LHC high luminosity upgrade requires two crabbing systems in increasing the peak luminosity, operating both vertically and horizontally at two interaction points of IP1 and IP5. The required system has tight dimensional constraints and needs to achieve higher operational gradients. A proof-of-principle 400 MHz crabbing cavity design has been successfully tested and has proven to be an ideal candidate for the crabbing system. The cylindrical proof-of-principle rf-dipole design has been adapted in to a square shaped design to further meet the dimensional requirements. The new rf-dipole design has been optimized in meeting the requirements in rf-properties, higher order …

Deep Exclusive Π+ Electroproduction Off The Proton At Clas, K. P. Adhikari, M. J. Amaryan, R. P. Bennett, G. E. Dodge, S. E. Kuhn, M. Mayer, C. S. Nepali, H. Seraydaryan, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The exclusive electroproduction of π ⁺ above the resonance region was studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory by scattering a 6GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of CLAS, together with the high luminosity, allowed us to measure the cross section for the γ ^* p → nπ ⁺ process in 140 (Q ², x _B , t) bins: 0.16 < x _B < 0.58, 1.6 GeV² < Q ² < 4.5 GeV² and 0.1 GeV² < −t < 5.3 GeV². For most bins, the statistical accuracy is on the order of a …

Demonstration Of A Novel Technique To Measure Two-Photon Exchange Effects In Elastic E±P Scattering, M. Niroula, L. B. Weinstein, D. Adikaram, J. Lanchiet, K. P. Adhikari, M. J. Amaryan, R. P. Bennett, C. E. Hyde, S.E. Kuhn, H. Seraydaryan

Physics Faculty Publications

Background: The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections.

Purpose: The TPE contributions depend on the sign of the lepton charge in e±p scattering, but the luminosities of secondary positron beams limited past measurement at large scattering angles, where the TPE effects are believe to be most significant. We present the results of a new experimental technique for making direct e±p comparisons, which …

Hom Damping Coupler Design For The 400-Mhz Rf Dipole Compact Crab Cavity For The Lhc Hilumi Upgrade, Zenghai Li, Lixin Ge, Jean R. Delayen, Subashini U. De Silva

Physics Faculty Publications

Crab cavities are adapted as the baseline design for the LHC HiLumi upgrade to achieve head-on beam-beam collisions for further improvement in luminosity. A 400- MHz compact RF dipole crab cavity design was developed by a joint effort between Old Dominion University and SLAC under the support of US LARP program. This design has shown very favorable RF parameters and can fit into the available beamline spacing for both vertical and horizontal crabbing schemes. A niobium proof-of-principle cavity based on such a design has been manufactured for vertical test. In addition, there are stringent wakefield requirements that needed to be …

Compact Superconducting Rf-Dipole Cavity Designs For Deflecting And Crabbing Applications, Subashini De Silva, Jean R. Delayen, A. Castilla

Physics Faculty Publications

Over the years the superconducting parallel-bar design has evolved into an rf-dipole cavity with improved properties. The new rf-dipole design is considered for a number of deflecting and crabbing applications. Some of those applications are the 499 MHz rf separator system for the Jefferson Lab 12 GeV upgrade, the 400 MHz crabbing cavity system for the proposed LHC high luminosity upgrade, and the 750 MHz crabbing cavity for the medium energy electron-ion collider in Jefferson Lab. In this paper we present the optimized rf design in terms of rf performance including rf properties, higher order modes (HOM) properties, multipacting, and …

Multipole Expansion Of The Fields In Superconducting High-Velocity Spoke Cavities, R. G. Olave, Jean R. Delayen, C. S. Hopper

Physics Faculty Publications

Multi-spokes superconducting cavities in the high-beta regime are being considered for a number of applications. In order to accurately model the dynamics of the particles in such cavities, knowledge of the fields off-axis are needed. We present a study of the multipoles expansion of the fields from an EM simulation field data for two-spokes cavities operating at 325 MHz, β = 0.82, and 500 MHz, β = 1.

Search For The Standard Model Higgs Boson In Eτ Final States, Ian James Howley

Physics Dissertations

Presented in this dissertation is a search for the standard model (SM) Higgs boson using the DØ detector at Fermilab in Batavia, IL. The SM is a fantastically accurate theory describing the fundamental interactions and particles of the Universe. The only undiscovered particle in the SM is the Higgs boson, which is hypothesized to be responsible for electroweak symmetry breaking and giving mass to all other particles. Considered in this search is the process H + X -> eτhjj, where e is an electron, τh is the hadronic decay of a τ, and j is a jet, using pp̄ collisions …

Interaction Of The Geomagnetic Field With Northward Interplanetary Magnetic Field, Shree K. Bhattarai

Physics Dissertations

The interaction of the solar wind with Earth's magnetic field causes the transfer of momentum and energy from the solar wind to geospace. The study of this interaction is gaining significance as our society is becoming more and more space based, due to which, predicting space weather has become more important. The solar wind interacts with the geomagnetic field primarily via two processes: viscous interaction and the magnetic reconnection. Both of these interactions result in the generation of an electric field in Earth's ionosphere. The overall topology and dynamics of the magnetosphere, as well as the electric field imposed on …

First Principles Study Of Properties Of The Oxidized Cu(100) And Cu(110), Antoine Yongonga Olenga

Physics Theses

Copper based catalysts are of importance to a number of industrial processes including the synthesis of methanol, the reduction and decomposition of nitrogen oxides, and treatment of waste water. In copper catalysis surface oxidation and oxidic overlayers are believed to play a crucial role. In this work using density functional theory (DFT) within the generalized gradient approximation (GGA) we have studied the stability and associated electronic properties of the oxidized Cu(100) and Cu(110) surfaces. Especially, we have focused on studies of changes in the interlayer spacing, electron work function, binding energy, and density of states with oxygen coverage. We have …

A Research Agenda For The Uae Ipad Initiative, Christina Gitsaki, Matthew Robby, Troy Priest, Khaled Hamdan, Yazid Ben-Chabane

All Works

The 2012-2013 academic year has seen the beginning of a national initiative in the United Arab Emirates to equip all students in federal universities/colleges with iPads, and to make use of this mobile device in teaching and learning. Within the context of this national initiative, each federal institution (Zayed University, UAE University and the Higher Colleges of Technology) has begun to implement iPads in its curriculum, and to gather data about this implementation to inform further development. In this paper, representatives of the three federal institutions map out the research approach which they are taking to investigate the progress of …

Early Eocene To Middle Miocene Cooling And Aridification Of East Antarctica, Sandra Passchier, Steven M. Bohaty, Francisco J. Jiménez‐Espejo, Jörg Pross, Ursu Röhl, Tina Van De Flierdt, Carlota Escutia, Henk Brinkhuis

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

[1] Few high‐latitude terrestrial records document the timing and nature of the Cenozoic “Greenhouse” to “Icehouse” transition. Here we exploit the bulk geochemistry of marine siliciclastic sediments from drill cores on Antarctica's continental margin to extract a unique semiquantitative temperature and precipitation record for Eocene to mid‐Miocene (~54–13 Ma). Alkaline elements are strongly enriched in the detrital mineral fraction in fine‐grained siliciclastic marine sediments and only occur as trace metals in the biogenic fraction. Hence, terrestrial climofunctions similar to the chemical index of alteration (CIA) can be applied to the alkaline major element geochemistry of marine sediments on continental margins …

Decision Support In Data Centers For Sustainability, Michael Pawlish, Aparna Varde, Stefan Robila

Department of Computer Science Faculty Scholarship and Creative Works

In this paper, we propose a decision support system (DSS) for the greening of data centers to help the environment, hence promoting sustainability. As society continues the relentless shift towards electronic communications there is a growing demand for greater storage and processing on data centers. A potential area of improvement is to gain greater server utilization rates since traditionally the phenomenon of 'server sprawl' occurs where more servers are added to the data center without seeking greater utilization rates on existing servers first. This implies maintaining more servers than actually needed that translates to greater carbon dioxide emissions causing potential …

Diffusion Of Vitamin B12 Across A Mesoporous Metal Organic Framework, Veronica Valencia

Undergraduate Journal of Mathematical Modeling: One + Two

We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water) at 2 different temperatures (room temperature and 37°C) by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion …

Modeling Urban Hydrology: A Comparison Of New Urbanist And Traditional Neighborhood Design Surface Runoff, C. Andrew Day, Keith A. Bremer Ph.D.

Geosciences Faculty Publications

Urban development affects the amount of potential surface runoff generated during storms by changing the amount of impervious cover across the landscape. However, the degree of surface runoff alteration depends on the type of urban development in place. New urbanist developments are designed with higher densities and encourage a diversity of land uses, while traditional neighborhood developments have a monotone land use pattern with medium-to- low densities. Two neighborhoods within the city of Austin, Texas- Mueller, a new urbanist development, and Circle C Ranch, a traditional neighborhood development- were used to study the effect of development type on potential surface …

Heteroclinic And Homoclinic Connections Between The Sun-Earth Triangular Points And Quasi-Satellite Orbits For Solar Observations, Pedro J. Llanos, Gerald R. Hintz, Martin W. Lo, James K. Miller

Publications

Investigation of new orbit geometries exhibits a very attractive behavior for a spacecraft to monitor space weather coming from the Sun. Several orbit transfer mechanisms are analyzed as potential alternatives to monitor solar activity such as a sub-solar orbit or quasi-satellite orbit and short and long heteroclinic and homoclinic connections between the triangular points L4 and L5 and the collinear point L3 of the CRTBP (circular restricted three-body problem) in the Sun-Earth system. These trajectories could serve as channels through where material can be transported from L5 to L3 by performing small maneuvers at the departure of the Trojan orbit. …

Adaptive Stochastic Conjugate Gradient Optimization For Temporal Medical Image Registration, Huanhuan Xu

LSU Master's Theses

We propose an Adaptive Stochastic Conjugate Gradient (ASCG) optimization algorithm for temporal medical image registration. This method combines the advantages of Conjugate Gradient (CG) method and Adaptive Stochastic Gradient Descent (ASGD) method. The main idea is that the search direction of ASGD is replaced by stochastic approximations of the conjugate gradient of the cost function. In addition, the step size of ASCG is based on the approximation of the Lipschitz constant of the stochastic gradient function. Thus, this algorithm could maintain the good properties of the conjugate gradient method, meanwhile it uses less gradient computation time per iteration and adjusts …