New Line Lists For Rovibrational And Rotational Transitions Within The Nh And Oh X2Π Ground States,
2014
University of York
New Line Lists For Rovibrational And Rotational Transitions Within The Nh And Oh X2Π Ground States, James S. A. Brooke, Peter F. Bernath, Colin Western, Gang Li, Gerrit Groenenboom
Chemistry & Biochemistry Faculty Publications
A new line list for rovibrational and rotational transitions within the NH X^3Σ{^-} ground state has been created, including line intensities in the form of Einstein A and f-values, for all possible bands up to v^'=6. The intensities are based on a new dipole moment function (DMF), which has been calculated using the internally contracted MRCI method with an aug-cc-pV6Z basis set. The programs RKR1, LEVEL and PGOPHER were used to calculate line positions and intensities using the most recent spectroscopic observations and the new DMF, and including the rotational dependence on the matrix elements. The Hund's case (b) matrix …
Tight Knot Spectrum In Qcd,
2014
Chapman University
Tight Knot Spectrum In Qcd, Roman V. Buniy, Jason Cantarella, Thomas W. Kephart, Eric Rawdon
Mathematics, Physics, and Computer Science Faculty Articles and Research
We model the observed J(++) mesonic mass spectrum in terms of energies for tightly knotted and linked chromoelectric QCD flux tubes. The data is fit with one- and two-parameter models. We predict a possible new state at approximately 1190 MeV and a plethora of new states above 1690 MeV.
An Audit Of A Hospital-Based Doppler Ultrasound Quality Control Protocol Using A Commercial String Doppler Phantom,
2014
St. James's Hospital Dublin
An Audit Of A Hospital-Based Doppler Ultrasound Quality Control Protocol Using A Commercial String Doppler Phantom, S. Cournane, A. J. Fagan, Jacinta Browne
Articles
Results from a four-year audit of a Doppler quality assurance (QA) program using a commercially available Doppler string phantom are presented. The suitability of the phantom was firstly determined and modifications were made to improve the reliability and quality of the measurements. QA of Doppler ultrasound equipment is very important as data obtained from these systems is used in patient management. It was found that if the braided-silk filament of the Doppler phantom was exchanged with an O-ring rubber filament and the velocity range below 50cm/s was avoided for Doppler quality control (QC) measurements, then the Maximum Velocity Accuracy (MVA) …
A Review Of Doppler Ultrasound Quality Assurance Protocols And Test Devices,
2014
Technological University Dublin
A Review Of Doppler Ultrasound Quality Assurance Protocols And Test Devices, Jacinta Browne
Articles
In this paper, an overview of Doppler ultrasound quality assurance (QA) testing will be presented in three sections. The first section will review the different Doppler ultrasound parameters recommended by professional bodies for use in QA protocols. The second section will include an evaluation and critique of the main test devices used to assess Doppler performance, while the final section of this paper will discuss which of the wide range of test devices have been found to be most suitable for inclusion in Doppler QA programmes. Pulsed Wave Spectral Doppler, Colour Doppler Imaging QA test protocols have been recommended over …
Separated Response Function Ratios In Exclusive, Forward Π± Electroproduction,
2014
Old Dominion University
Separated Response Function Ratios In Exclusive, Forward Π± Electroproduction, G. M. Huber, H. P. Blok, C. Butuceanu, D. Gaskell, T. Horn, D. J. Mack, D. Abbott, A. Klein, L. M. Qin, K. Vansyoc
Physics Faculty Publications
The study of exclusive π± electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio R-L=sigma(pi-)(L) / sigma(pi+)(L) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of R-T=sigma(pi-)(L) / sigma(pi+)(L) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier …
Neutron Spin Struccture With Polarized Deuterons And Spectator Proton Tagging At Eic,
2014
Old Dominion University
Neutron Spin Struccture With Polarized Deuterons And Spectator Proton Tagging At Eic, W. Cosyn, V. Guzey, D. W. Higinbotham, C. Hyde, S. Kuhn, P. Nadel-Turonski, K. Park, M. Sargsian, M. Strikman, C. Weiss
Physics Faculty Publications
The neutron's deep-inelastic structure functions provide essential information for the flavor separation of the nucleon parton densities, the nucleon spin decomposition, and precision studies of QCD phenomena in the flavor-singlet and nonsinglet sectors. Traditional inclusive measurements on nuclear targets are limited by dilution from scattering on protons, Fermi motion and binding effects, final-state interactions, and nuclear shadowing at x ≪ 0.1. An Electron-Ion Collider (EIC) would enable next-generation measurements of neutron structure with polarized deuteron beams and detection of forward-moving spectator protons over a wide range of recoil momenta (0 < pR < several 100MeV in the nucleus rest frame). The free neutron structure functions could be obtained by extrapolating the measured recoil momentum distributions to the on-shell point. The method eliminates nuclear modifications and can be applied to polarized scattering, as well as to semi-inclusive and exclusive final states. We review the prospects for neutron structure measurements with spectator tagging at EIC, the status of R&D efforts, and the accelerator and detector requirements.
Diagnostics Of An O2–He Rf Atmospheric Plasma Discharge By Spectral Emission,
2014
Technological University Dublin
Diagnostics Of An O2–He Rf Atmospheric Plasma Discharge By Spectral Emission, Vladimir Milosavljevic, Mick Donegan, Patrick J. Cullen, Denis Dowling
Articles
In this paper optical emission spectroscopy (OES) is used as a Diagnostic technique for the measurement of atomic and molecular spectral emissions generated using a helium rf industrial atmospheric plasma jet system. The OES of neutral atomic spectral lines and molecular bands are investigated over a range of plasma process parameters.
/="/">Wavelength resolve optical emission profiles suggest that the emission of helium’s spectral lines shows that the high energy electrons have a larger influence than helium metastables on the overall spectral emission. Furthermore, the experimental data indicates that the use of high helium flow rates, in any confined open …
Magneto-Optical Effects And Precision Measurement Physics: Accessing The Magnetic Faraday Effect Of Polarized 3He With A Triple Modulation Technique,
2014
University of Kentucky
Magneto-Optical Effects And Precision Measurement Physics: Accessing The Magnetic Faraday Effect Of Polarized 3He With A Triple Modulation Technique, Gretchen Phelps
Theses and Dissertations--Physics and Astronomy
This work is comprised of the study of two magneto-optical phenomena: the Kerr effect and the Faraday effect. Neutron physics experiments often utilize polarized neutrons, and one method to generate or guide polarized neutrons involves the use of a system of magnetic super-mirrors. Experience shows that the magnetization of the super-mirror may decay with time; therefore, we implemented the surface magneto-optical Kerr effect (SMOKE) to study the temporal behavior of the magnetization of a magnetized remnant super-mirror sample, where a sensitivity of 0.1 mrad was obtained. Unique to our set-up was the method in which the various magnetization directions were …
Optically-Pumped Spin-Exchange Polarized Electron Source,
2013
University of Nebraska-Lincoln
Optically-Pumped Spin-Exchange Polarized Electron Source, Munir Pirbhai
Department of Physics and Astronomy: Dissertations, Theses, and Student Research
Polarized electron beams are an indispensable probe of spin-dependent phenomena in fields of atomic and molecular physics, magnetism and biophysics. While their uses have become widespread, the standard source based on negative electron affinity gallium arsenide (GaAs) remains technically complicated. This has hindered progress on many experiments involving spin-polarized electrons, especially those using target gas loads, which tend to adversely affect the performance of GaAs sources. A robust system based on an alternative way to make polarized electron beams has been devised in this study, which builds on previous work done in our lab. It involves spin-exchange collisions between free, …
Electron-Impact Vibrational Excitation Of Vibrationally Excited H2 Molecules Involving The Resonant 2(Sigma)G+ Rydberg-Excited Electronic State,
2013
Istituto di Metodologie Inorganiche e Plasmi, CNR, Bari, Italy
Electron-Impact Vibrational Excitation Of Vibrationally Excited H2 Molecules Involving The Resonant 2(Sigma)G+ Rydberg-Excited Electronic State, R Celiberto, R. K. Janev, V Laporta, J Tennyson, J. M. Wadehra
Physics and Astronomy Faculty Research Publications
Electron-impact theoretical cross sections and rate coefficients for vibrational excitation of vibrationally excited H2 molecules, occurring through the H−2 resonant species in the 2Σ+g Rydberg-excited electronic state, are presented. The cross sections are calculated as functions of the incident electron energy by adopting the local-complex-potential model for resonant collisions and by using ab initio calculated molecular potentials and resonance widths. The calculations have been extended to all possible vibrational transitions linking all 15 vibrational levels of the electronic ground state of the H2 molecule. The corresponding rate coefficients are also obtained as a function of the electron temperature by assuming …
Infrared Skin Damage Thresholds From 1319-Nm Continous-Wave Laser Exposures,
2013
Air Force Research Laboratory
Infrared Skin Damage Thresholds From 1319-Nm Continous-Wave Laser Exposures, Jeffrey W. Oliver, Revecca Vincelette, Gary Noojin, Clifton D. Clark, Corey Harbert, Kurt J. Schuster, Aurora D. Schingledecker, Semih S. Kumru, Justin Maughan, Naomi Kitzis, Gavin D. Buffington, David J. Stolarski, Robert J. Thomas
Physics Faculty Publications
A series of experiments were conducted in vivo using Yucatan miniature pigs (Sus scrofa domestica) to determine thermal damage thresholds to the skin from 1319-nm continuous-wave Nd:YAG laser irradiation. Experiments employed exposure durations of 0.25, 1.0, 2.5, and 10 s and beam diameters of ∼0.6 and 1 cm. Thermal imagery data provided a time-dependent surface temperature response from the laser. A damage endpoint of fifty percent probability of a minimally visible effect was used to determine threshold for damage at 1 and 24 h postexposure. Predicted thermal response and damage thresholds are compared with a numerical model of opticalthermal interaction. …
Electron Tunneling Characteristics Of A Cubic Quantum Dot, (Pbs)32,
2013
Michigan Technological University
Electron Tunneling Characteristics Of A Cubic Quantum Dot, (Pbs)32, Sanjeev K. Gupta, Haiying He, Douglas Banyai, Anil K. Kandalam, Ravindra Pandey
Physics & Engineering Faculty Publications
No abstract provided.
Gravitational And Electromagnetic Waves On The Null Cone,
2013
Marshall University
Gravitational And Electromagnetic Waves On The Null Cone, Maria Babiuc-Hamilton
Physics Faculty Research
Gravitational radiation is properly defined only at future null infinity, but mathematically it is estimated at a finite radius, and then extrapolated. Our group developed a characteristic waveform extraction tool, implemented in an open source code, which computes the gravitational waves infinitely far from their source, in terms of compactified null cones, by numerically solving Einstein equation. We add electromagnetic waves to the null cone, by deriving a formulation of the Einstein-Maxwell equations suitable to be numerically implemented into a characteristic code, that will evolve and calculate both the gravitational waves and their electromagnetic counterparts all the way to infinity.
Molecular Dynamics Model Of Carbon Nanotubes In Epon 862/Detda Polymer,
2013
Embry-Riddle Aeronautical University
Molecular Dynamics Model Of Carbon Nanotubes In Epon 862/Detda Polymer, Guttormur Arnar Ingvason
Doctoral Dissertations and Master's Theses
The aerospace industry is interested in increasing the strength while reducing the weight of carbon fiber composite materials. Adding single walled carbon nanotubes (SWCNT) to a polymer matrix can achieve that goal by improving delamination properties of the composite. Due to the complexity of polymer molecules and the curing process, few 3-D Molecular Dynamics simulations of a polymer-SWCNT composite have been run. Our model runs on the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), with a COMPASS (Condensed phase Optimized Molecular Potential for Atomistic Simulations Studies) potential to represent the interactions between the atoms of the polymer and the SWCNT. This …
Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution,
2013
University of Nebraska-Lincoln
Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw
Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research
Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles …
Double Resonance Spectroscopy Of The D1Πu+ And B''B-Bar 1Σu+ States Near The Third Dissociation Threshold Of H2,
2013
Bryn Mawr College
Double Resonance Spectroscopy Of The D1Πu+ And B''B-Bar 1Σu+ States Near The Third Dissociation Threshold Of H2, R. C. Ekey, A. E. Cordova, W. Duan, Alexander M. Chartrand, Elizabeth Mccormack
Physics Faculty Research and Scholarship
Double-resonance laser spectroscopy via the E, F 1Σg+, v' = 6, J' state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14–17 levels of the D1Πu+ state of H2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al. 2010 J. Chem. Phys. 133 144317) and fully ab …
Above-Threshold Ionization As Temporal Multi-Slit Interference,
2013
Southern Adventist University
Above-Threshold Ionization As Temporal Multi-Slit Interference, William B. Laing Iii
Faculty Works
When atoms are subjected to a laser pulse of sufficiently high intensity, electrons are ionized by absorbing multiple photons in excess of the ionization potential. The resulting sequence of peaks in the photoelectron spectrum separated by the energy of one photon is called “above-threshold ionization” (ATI). This time-independent description of ATI invokes the language of photons, even though calculations are performed using the time-dependent Schrodinger equation with a classical electric field. We demonstrate that the energy-periodic structure of ATI can be understood from the interference of ionized electron wavepackets produced periodically each half-cycle of the laser field. Using this simple …
Above-Threshold Ionization As Temporal Multi-Slit Interference,
2013
Southern Adventist University
Above-Threshold Ionization As Temporal Multi-Slit Interference, William B. Laing Iii, B.D. Esry
Faculty Works
When atoms are subjected to a laser pulse of sufficiently high intensity, electrons are ionized by absorbing multiple photons in excess of the ionization potential. The resulting sequence of peaks in the photoelectron spectrum separated by the energy of one photon is called ``above-threshold ionization'' (ATI). This time-independent description of ATI invokes the language of photons, even though calculations are performed using the time-dependent Schrodinger equation with a classical electric field. We demonstrate that the energy-periodic structure of ATI can be understood from the interference of ionized electron wavepackets produced periodically each half-cycle of the laser field. Using this simple …
Resonant Enhancement Of The Harmonic-Generation Spectrum Of Beryllium,
2013
University of Nebraska-Lincoln
Resonant Enhancement Of The Harmonic-Generation Spectrum Of Beryllium, Jean Marcel Ngoko Djiokap, Anthony F. Starace
Anthony F. Starace Publications
The high-order harmonic-generation (HHG) spectrum of Be is investigated in the multiphoton regime by solving the full-dimensional, two-active-electron, time-dependent Schr¨odinger equation in an intense (≈1013 W/cm2), 30-cycle laser field. As the laser frequency ωL varies from 1.7 to 1.8 eV (which is in the tunable range of a Ti:sapphire laser), the seventh harmonic becomes resonant sequentially with the transition between the ground state and two doubly excited autoionizing states, 2p4s(1P) (at ωL = 1.734 eV) and 2p5s …
Carrier-Envelope-Phase-Induced Asymmetries In Double Ionization Of Helium By An Intense Few-Cycle Xuv Pulse,
2013
University of Nebraska-Lincoln
Carrier-Envelope-Phase-Induced Asymmetries In Double Ionization Of Helium By An Intense Few-Cycle Xuv Pulse, Jean Marcel Ngoko Djiokap, N. L. Manakov, A. V. Meremianin, Anthony F. Starace
Anthony F. Starace Publications
The carrier-envelope-phase (CEP) dependence of electron angular distributions in double ionization of He by an arbitrarily polarized, few-cycle, intense XUV pulse is formulated using perturbation theory (PT) in the pulse amplitude. Owing to the broad pulse bandwidth, interference of first- and second-order PT amplitudes produces asymmetric angular distributions sensitive to the CEP. The PT parametrization is shown to be valid by comparing with results of solutions of the full-dimensional, two-electron time-dependent Schrödinger equation for the case of linear polarization.
