Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 50

Full-Text Articles in Physical Sciences and Mathematics

Modeling Martian Planetary Entry Descent And Landing Using Monte Carlo Driven Response Surface Methodology, Narcrisha S. Norman Oct 2012

Modeling Martian Planetary Entry Descent And Landing Using Monte Carlo Driven Response Surface Methodology, Narcrisha S. Norman

Mechanical & Aerospace Engineering Theses & Dissertations

Response surface methodology (RSM) is a statistical method that explores the relationships between several descriptive variables and one or more response variables. For over sixty years, among other areas, it has been utilized in quality engineering, process engineering, aircraft engineering, economics, chemical engineering, automotive engineering and design/technique optimization. In this dissertation, RSM is utilized to produce regression models that represent the planetary entry, descent and landing (EDL) process. A complete understanding of EDL process is an essential component of any planetary exploration. Research in this area is ongoing and confidence in the ability to explore known celestial bodies is growing. …


Application Of Chebyshev Formalism To Identify Nonlinear Magnetic Field Components In Beam Transport System, Michael Spata Jul 2012

Application Of Chebyshev Formalism To Identify Nonlinear Magnetic Field Components In Beam Transport System, Michael Spata

Physics Theses & Dissertations

An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a beam-based technique for characterizing the extent of the nonlinearity of the magnetic fields of a beam transport system. Horizontally and vertically oriented pairs of air-core kicker magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the beam orbit relative to the unperturbed reference orbit. Fourier decomposition of the position data at eight different points along the beamline was then used to measure the amplitude of these frequencies. For a purely linear transport system one expects to find solely the …


Dynamics Of Non-Thermal Plasma Jets Under Variable Pressure, Mehmet Arda Akman Jul 2012

Dynamics Of Non-Thermal Plasma Jets Under Variable Pressure, Mehmet Arda Akman

Electrical & Computer Engineering Theses & Dissertations

Non-thermal plasma (NTP) jets driven by short DC pulses have attracted the attention of researchers within the past decade due to their promising bio-medical applications in the fields of wound healing, cancer treatment and sterilization. The ability to operate at atmospheric pressure, room temperature and simple device configuration has greatly contributed to their appeal and adoption in the plasma science community. However, the mechanisms that sustain the plasma generation and propagation in ambient air are currently a topic of debate. For instance, what appears as a continuous stream of a plasma plume extending outwards from a plasma device into the …


Section Abstracts: Astronomy, Mathematics And Physics With Materials Science Apr 2012

Section Abstracts: Astronomy, Mathematics And Physics With Materials Science

Virginia Journal of Science

Abstracts of the Astronomy, Mathematics, and Physics with Material Science Section for the 90th Annual Meeting of the Virginia Academy of Science, May 23-25, 2012, Norfolk State University, Norfolk, Virginia


Single And Double Spin Asymmetries For Pion Electro-Production From The Deuteron In The Resonance Region, Sharon L. Careccia Apr 2012

Single And Double Spin Asymmetries For Pion Electro-Production From The Deuteron In The Resonance Region, Sharon L. Careccia

Physics Theses & Dissertations

The single and double spin asymmetries At and Aet have been measured in π- electro-production off the deuteron using a longitudinally polarized electron beam and a polarized ND3 target. The electron beam was polarized using a strained GaAs cathode and the target was polarized using Dynamic Nuclear Polarization. The data were collected at beam energies of 1.6, 1.7, 2.5 and 4.2 GeV in Hall B at Jefferson Lab in the spring of 2001. The final state particles were detected in the CEBAF Large Acceptance Spectrometer (CLAS). The d(e,e'π-p)p exclusive channel was identified using the missing mass …


Optimization Framework For A Radio Frequency Gun Based Injector, Alicia S. Hofler Apr 2012

Optimization Framework For A Radio Frequency Gun Based Injector, Alicia S. Hofler

Electrical & Computer Engineering Theses & Dissertations

Linear accelerator based light sources are used to produce coherent x-ray beams with unprecedented peak intensity. In these devices, the key parameters of the photon beam such as brilliance and coherence are directly dependent on the electron beam parameters. This leads to stringent beam quality requirements for the electron beam source. Radio frequency (RF) guns are used in such light sources since they accelerate electrons to relativistic energies over a very short distance, thus minimizing the beam quality degradation due to space charge effects within the particle bunch. Designing such sources including optimization of its beam parameters is a complex …


Laser Processing Of Metals And Polymers, Senthilraja Singaravelu Apr 2012

Laser Processing Of Metals And Polymers, Senthilraja Singaravelu

Physics Theses & Dissertations

A laser offers a unique set of opportunities for precise delivery of high quality coherent energy. This energy can be tailored to alter the properties of material allowing a very flexible adjustment of the interaction that can lead to melting, vaporization, or just surface modification. Nowadays laser systems can be found in nearly all branches of research and industry for numerous applications. Sufficient evidence exists in the literature to suggest that further advancements in the field of laser material processing will rely significantly on the development of new process schemes. As a result they can be applied in various applications …


Case Studies In Many-Body Physics, Ana Samolov Apr 2012

Case Studies In Many-Body Physics, Ana Samolov

Physics Theses & Dissertations

The many-body problem refers to any physical problem made of more than two interacting particles. With increasing number of particles in a system, their coupling and entanglement becomes more complex, and there is no general analytic solution even for a three-body classical or quantum systems. However, some of the most fascinating phenomena in nature are products of collective effects. Therefore, significant efforts have been made in both experiment and theory to unravel some specific many-body problems. If we look at still unanswered physics questions we see that for most of these problems addressing the many-body interactions is a key issue. …


Measurement Of The Neutron F2 Structure Function Via Spectator Tagging With Clas, N. Baillie, S. Tkachenko, J. Zhang, P. Bosted, S. Bültmann, M. E. Christy, H. Fenker, K. A. Griffioen, C. E. Keppel, S. E. Kuhn, K. P. Adhikari, D. Adikaram, M. J. Amaryan, H. Baghdasaryan, G. Dodge, N. Guler, C. E. Hyde, A. Klein, A. Klimenko, L. B. Weinstein Apr 2012

Measurement Of The Neutron F2 Structure Function Via Spectator Tagging With Clas, N. Baillie, S. Tkachenko, J. Zhang, P. Bosted, S. Bültmann, M. E. Christy, H. Fenker, K. A. Griffioen, C. E. Keppel, S. E. Kuhn, K. P. Adhikari, D. Adikaram, M. J. Amaryan, H. Baghdasaryan, G. Dodge, N. Guler, C. E. Hyde, A. Klein, A. Klimenko, L. B. Weinstein

Physics Faculty Publications

We report on the first measurement of the F2 structure function of the neutron from the semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ≲ 100MeV/c and their angles to ≳ 100° relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The Fn2 data collected cover the nucleon-resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65 < Q2 < 4.52 GeV2, with uncertainties from nuclear corrections estimated to be less …


Global Variations Of Hdo And Hdo/H2o Ratios In The Upper Troposphere And Lower Stratosphere Derived From Ace-Fts Satellite Measurements, William J. Randel, Elisabeth Moyer, Mijeong Park, Eric Jensen, Peter Bernath Mar 2012

Global Variations Of Hdo And Hdo/H2o Ratios In The Upper Troposphere And Lower Stratosphere Derived From Ace-Fts Satellite Measurements, William J. Randel, Elisabeth Moyer, Mijeong Park, Eric Jensen, Peter Bernath

Chemistry & Biochemistry Faculty Publications

High-quality satellite observations of water and deuterated water in the upper troposphere and lower stratosphere (UTLS) from the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) are used to map global climatological behavior. Spatial and temporal variability in these data suggest that convection plays a significant role in setting water vapor isotopic composition in these regions. In many instances, enhancements in HDO/H2O (i.e., δD) are closely tied to patterns of climatological deep convection and uncorrelated with water vapor, although convection appears to have different isotopic effects in different locations. The ACE-FTS data reveal seasonal variations in the tropics …


Properties Of Cu(In,Ga) Se2 Thin Films And Solar Cells Deposited By Hybrid Process, S. Marsillac, H. Khatri, K. Aryal, R. W. Collins Feb 2012

Properties Of Cu(In,Ga) Se2 Thin Films And Solar Cells Deposited By Hybrid Process, S. Marsillac, H. Khatri, K. Aryal, R. W. Collins

Electrical & Computer Engineering Faculty Publications

Cu(In,Ga)Se-2 solar cells were fabricated using a hybrid cosputtering/evaporation process, and efficiencies as high as 12.4% were achieved. The films were characterized by energy-dispersive X-ray spectroscopy, glancing incidence X-ray diffraction, scanning electron microscopy, auger electron spectroscopy, and transmittance and reflectance spectroscopy, and their properties were compared to the ones of films deposited by coevaporation. Even though the films were relatively similar, the ones deposited by the hybrid process tend to have smaller grains with a slightly preferred orientation along the (112) axis and a rougher surface. Both types of films have uniform composition through the depth. Characterization of these films …


Flow Over A Traveling Wavy Foil With A Passively Flapping Flat Plate, Nansheng Liu, Yan Peng, Youwen Liang, Xiyun Lu Jan 2012

Flow Over A Traveling Wavy Foil With A Passively Flapping Flat Plate, Nansheng Liu, Yan Peng, Youwen Liang, Xiyun Lu

Mathematics & Statistics Faculty Publications

Flow over a traveling wavy foil with a passively flapping flat plate has been investigated using a multiblock lattice Boltzmann equation and the immersed boundary method. The foil undergoes prescribed undulations in the lateral direction and the rigid flat plate has passive motion determined by the fluid structure interaction. This simplified model is used to study the effect of the fish caudal fin and its flexibility on the locomotion of swimming animals. The flexibility of the caudal fin is modeled by a torsion spring acting about the pivot at the conjuncture of the wavy foil and the flat plate. The …


Inclusive Charged Hadron Elliptic Flow In Au + Au Collisions At √ˢᴺᴺ = 7.7-39 Gev, L. Adamczyk, G. Agakishiev, S. Bültmann, I Koralt, D. Plyku, Star Collaboration Jan 2012

Inclusive Charged Hadron Elliptic Flow In Au + Au Collisions At √ˢᴺᴺ = 7.7-39 Gev, L. Adamczyk, G. Agakishiev, S. Bültmann, I Koralt, D. Plyku, Star Collaboration

Physics Faculty Publications

A systematic study is presented for centrality, transverse momentum pT, and pseudorapidity (η) dependence of the inclusive charged hadron elliptic flow v2 at midrapidity (|η| < 1.0) in Au + Au collisions at √ˢᴺᴺ = 7.7, 11.5, 19.6, 27, and 39 GeV. The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and four-particle cumulants (v2{4}), are presented to investigate nonflow correlations and v2 fluctuations. We observe that the difference between v2{2} and v2{4} is smaller at the lower collision energies. Values of v2, scaled by the initial coordinate space eccentricity, v2/ϵ, as a function of pT are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results …


Superconducting Spoke Cavities For Electron And High-Velocity Proton Linacs, J. R. Delayen Jan 2012

Superconducting Spoke Cavities For Electron And High-Velocity Proton Linacs, J. R. Delayen

Physics Faculty Publications

Spoke resonantors are currently under development for many proton machines but these structures are also considered for high beta electron linacs as well. These structures compare well to traditional elliptical cavities.


Introduction To Special Section On Recent Advances In The Study Of Optical Variability In The Near-Surface And Upper Ocean, T. Dickey, M. L. Banner, P. Bhandari, T. Boyd, L. Carvalho, O. Wurl Jan 2012

Introduction To Special Section On Recent Advances In The Study Of Optical Variability In The Near-Surface And Upper Ocean, T. Dickey, M. L. Banner, P. Bhandari, T. Boyd, L. Carvalho, O. Wurl

OES Faculty Publications

Optical variability occurs in the near-surface and upper ocean on very short time and space scales (e.g., milliseconds and millimeters and less) as well as greater scales. This variability is caused by solar, meteorological, and other physical forcing as well as biological and chemical processes that affect optical properties and their distributions, which in turn control the propagation of light across the air-sea interface and within the upper ocean. Recent developments in several technologies and modeling capabilities have enabled the investigation of a variety of fundamental and applied problems related to upper ocean physics, chemistry, and light propagation and utilization …


Unitary Qubit Lattice Gas Representation Of 2d And 3d Quantum Turbulence, George Vahala, Bo Zhang, Jeffrey Yepez, Linda L. Vahala, Min Soe Jan 2012

Unitary Qubit Lattice Gas Representation Of 2d And 3d Quantum Turbulence, George Vahala, Bo Zhang, Jeffrey Yepez, Linda L. Vahala, Min Soe

Electrical & Computer Engineering Faculty Publications

No abstract provided.


In Situ And Ex Situ Studies Of Molybdenum Thin Films Deposited By Rf And Dc Magnetron Sputtering As A Back Contact For Cigs Solar Cells, K. P. Aryal, H. Khatri, R. W. Collins, S. Marsillac Jan 2012

In Situ And Ex Situ Studies Of Molybdenum Thin Films Deposited By Rf And Dc Magnetron Sputtering As A Back Contact For Cigs Solar Cells, K. P. Aryal, H. Khatri, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Molybdenum thin films were deposited by rf and dc magnetron sputtering and their properties analyzed with regards to their potential application as a back contact for CIGS solar cells. It is shown that both types of films tend to transition from tensile to compressive strain when the deposition pressure increases, while the conductivity and the grain size decreas. The nucleation of the films characterized by in situ and real time spectroscopic ellipsometry shows that both films follow a Volmer-Weber growth, with a higher surface roughness and lower deposition rate for the rf deposited films. The electronic relaxation time was then …


Design And Development Of Superconducting Parallel-Bar Deflecting/Crabbing Cavities, Subashini De Silva, Jean R. Delayen Jan 2012

Design And Development Of Superconducting Parallel-Bar Deflecting/Crabbing Cavities, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

The superconducting parallel-bar cavity is a deflecting/crabbing cavity with attractive properties that is being considered for a number of applications. We present the designs of a 499 MHz deflecting cavity developed for the Jefferson Lab 12 GeV Upgrade and a 400 MHz crabbing cavity for the LHC High Luminosity Upgrade. Prototypes of these two cavities are now under development and fabrication.


Development Of Superconducting 500 Mhz Multi-Spoke Cavity For Electron Linacs, Dmitry Gorelov, Charles H. Boulware, Terry Grimm, Jean R. Delayen, C. S. Hopper, R. G. Olgave, Subashini U. De Silva Jan 2012

Development Of Superconducting 500 Mhz Multi-Spoke Cavity For Electron Linacs, Dmitry Gorelov, Charles H. Boulware, Terry Grimm, Jean R. Delayen, C. S. Hopper, R. G. Olgave, Subashini U. De Silva

Physics Faculty Publications

Multi-spoke cavities are well-known options for acceleration of heavy and light ions. A recently developed multi-spoke cavity for β=1 presents an attractive opportunity to use this cavity type for electron accelerators. One of the main attractive features of this cavity type is its compactness for relatively low frequency. A simplified design at 500 MHz allowed building of a multi-spoke cavity and cryomodule in a 2-year time frame with confidence and development of effective manufacturing techniques. It also constitutes an important step in proving the usefulness of this kind of cavity design for new applications in the electron machines. Niowave is …


First Remote Sensing Observations Of Trifluoromethane (Hfc-23) In The Upper Troposphere And Lower Stratosphere, Jeremy J. Harrison, Christopher D. Boone, Alexander T. Brown, Nicholas D. C. Allen, Geoffrey C. Toon, Peter F. Bernath Jan 2012

First Remote Sensing Observations Of Trifluoromethane (Hfc-23) In The Upper Troposphere And Lower Stratosphere, Jeremy J. Harrison, Christopher D. Boone, Alexander T. Brown, Nicholas D. C. Allen, Geoffrey C. Toon, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

This work reports the first remote sensing measurements of atmospheric HFC-23 (CHF3) using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the Jet Propulsion Laboratory Mark IV (MkIV) balloon interferometer. A total of 8809 ACE occultations measured between 2004 and 2010 have been processed, along with 24 MkIV occultations measured between 1989 and 2007. ACE data (yearly averages over the 10-25 km altitude range) in the tropics/subtropics (40°S-40°N) reveal a trend of 4.0 ± 1.6% per year in the growth of HFC-23 for 2004-2009 (or 3.9 ± 1.2% per year for 2004-2010), …


Ρ0 Photoproduction In Auau Collisions At √ Snn = 62.4 Gev Measured With The Star Detector, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, S. Bueltmann, I. Koralt, D. Plyku Jan 2012

Ρ0 Photoproduction In Auau Collisions At √ Snn = 62.4 Gev Measured With The Star Detector, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, S. Bueltmann, I. Koralt, D. Plyku

Physics Faculty Publications

Vector mesons may be photoproduced in relativistic heavy-ion collisions when a virtual photon emitted by one nucleus scatters from the other nucleus, emerging as a vector meson. The STAR Collaboration has previously presented measurements of coherent ρ0 photoproduction at center of mass energies of 130 GeV and 200 GeV in AuAu collisions. Here, we present a measurement of the cross section at 62.4 GeV; we find that the cross section for coherent ρ0 photoproduction with nuclear breakup is 10.5 ± 1.5 ± 1.6mb at 62.4 GeV. The cross-section ratio between 200 GeV and 62.4 GeV is 4.4 ± 0.6, …


System Size And Energy Dependence Of Near-Side Dihadron Correlations, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, S. Bueltmann, I. Koralt, D. Plyku Jan 2012

System Size And Energy Dependence Of Near-Side Dihadron Correlations, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, S. Bueltmann, I. Koralt, D. Plyku

Physics Faculty Publications

Two-particle azimuthal (Δφ) and pseudorapidity (Δη) correlations using a trigger particle with large transverse momentum (PT)in d+Au, Cu+Cu, and Au+Au collisions at √ sNN = 62.4 GeV and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider are presented. The near-side correlation is separated into a jet-like component, narrow in both Δφ and Δη, and the ridge, narrow in Δφ but broad in Δη. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated PT. The behavior of the …


Multipacting Analysis Of High-Velocity Superconducting Spoke Resonators, C. S. Hopper, J. R. Delayen Jan 2012

Multipacting Analysis Of High-Velocity Superconducting Spoke Resonators, C. S. Hopper, J. R. Delayen

Physics Faculty Publications

Some of the advantages of superconducting spoke cavities are currently being investigated for the high-velocity regime. When determining a final, optimized geometry, one must consider the possible limiting effects multipacting could have on the cavity. We report on the results of analytical calculations and numerical simulations of multipacting electrons in superconducting spoke cavities and methods for reducing their impact.


Engineering Of A Superconducting 400 Mhz Crabbing Cavity For The Lhc Hilumi Upgrade, Dmitry Gorelov, Terry Grimm, Subashini Uddika De Silva, Jean Roger Delayen Jan 2012

Engineering Of A Superconducting 400 Mhz Crabbing Cavity For The Lhc Hilumi Upgrade, Dmitry Gorelov, Terry Grimm, Subashini Uddika De Silva, Jean Roger Delayen

Physics Faculty Publications

The recently developed new simplified design for the 400 MHz LHC crabbing cavity presents attractive properties compared to conventional designs. The proposed approach can be equally compact in both transverse dimensions and allows horizontal as well as vertical deflection of the beam in the collider. The significant modification of the parallel-bar design with the bars merged to the side walls of the cavity gives improved properties, such as better mode separation and reduced surface fields [1]. A transverse deflecting voltage of 4.2 MV in a single cavity can be expected with the peak surface electric field lower then 45 MV/m …


Development Of Spoke Cavities For High Velocity Applications, C. S. Hopper, R. G. Olave, Jean R. Delayen Jan 2012

Development Of Spoke Cavities For High Velocity Applications, C. S. Hopper, R. G. Olave, Jean R. Delayen

Physics Faculty Publications

In response to recent interest in alternatives to TM-type cavities for low-frequency, high-velocity applications we have initiated a program for the development of multispoke superconducting cavities. We have completed the electromagnetic design for two-spoke cavities operating at 325, 352, 500, and 700 MHz with a design velocity of β0 = 0.82 or β0 = 1. We present the results of the optimization, higher order mode (HOM) analysis, multipacting analysis, and an initial analysis of multipole effects of the fundamental accelerating mode.


Electric-Field-Induced Interfacial Instabilities Of A Soft Elastic Membrane Confined Between Viscous Layers, Mohar Dey, Dipankar Bandyopadhyay, Ashutosh Sharma, Shizhi Qian, Sang Woo Joo Jan 2012

Electric-Field-Induced Interfacial Instabilities Of A Soft Elastic Membrane Confined Between Viscous Layers, Mohar Dey, Dipankar Bandyopadhyay, Ashutosh Sharma, Shizhi Qian, Sang Woo Joo

Mechanical & Aerospace Engineering Faculty Publications

We explore the electric-field-induced interfacial instabilities of a trilayer composed of a thin elastic film confined between two viscous layers. A linear stability analysis (LSA) is performed to uncover the growth rate and length scale of the different unstable modes. Application of a normal external electric field on such a configuration can deform the two coupled elastic-viscous interfaces either by an in-phase bending or an antiphase squeezing mode. The bending mode has a long-wave nature, and is present even at a vanishingly small destabilizing field. In contrast, the squeezing mode has finite wave-number characteristics and originates only beyond a threshold …


Microfluidic Impedance Spectroscopy As A Tool For Quantitative Biology And Biotechnology, Ahmet C. Sabuncu, Jie Zhuang, Juergen F. Kolb, Ali Beskok Jan 2012

Microfluidic Impedance Spectroscopy As A Tool For Quantitative Biology And Biotechnology, Ahmet C. Sabuncu, Jie Zhuang, Juergen F. Kolb, Ali Beskok

Mechanical & Aerospace Engineering Faculty Publications

A microfluidic device that is able to perform dielectric spectroscopy is developed. The device consists of a measurement chamber that is 250 μm thick and 750 μm radius. Around 1000 cells fit inside the chamber assuming average quantities for cell radius and volume fraction. This number is about 1000 folds lower than the capacity of conventional fixtures. A T-cell leukemia cell line Jurkat is tested using the microfluidic device. Measurements of deionized water and salt solutions are utilized to determine parasitic effects and geometric capacitance of the device. Physical models, including Maxwell-Wagner mixture and double shell models, are used to …


Technical Note: A Trace Gas Climatology Derived From The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Data Set, A. Jones, K. A. Walker, J. J. Jin, J. R. Taylor, C. D. Boone, P. F. Bernath, S. Brohede, G. L. Manney, S. Mcleod, R. Hughes, W. H. Daffer Jan 2012

Technical Note: A Trace Gas Climatology Derived From The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Data Set, A. Jones, K. A. Walker, J. J. Jin, J. R. Taylor, C. D. Boone, P. F. Bernath, S. Brohede, G. L. Manney, S. Mcleod, R. Hughes, W. H. Daffer

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) aboard the Canadian satellite SCISAT (launched in August 2003) was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month …


Optical Detection Of Melting Point Depression For Silver Nanoparticles Via In Situ Real Time Spectroscopic Ellipsometry, S. A. Little, T. Begou, R. W. Collins, S. Marsillac Jan 2012

Optical Detection Of Melting Point Depression For Silver Nanoparticles Via In Situ Real Time Spectroscopic Ellipsometry, S. A. Little, T. Begou, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Silver nanoparticle films were deposited by sputtering at room temperature and were annealed while monitoring by real time spectroscopic ellipsometry (SE). The nanoparticle dielectric functions (0.75 eV-6.5 eV) obtained by SE were modeled using Lorentz and generalized oscillators for the nanoparticle plasmon polariton (NPP) and interband transitions, respectively. The nanoparticle melting point could be identified from variations in the oscillator parameters during annealing, and this identification was further confirmed after cooling through significant, irreversible changes in these parameters relative to the as-deposited film. The variation in melting point with physical thickness, and thus average nanoparticle diameter, as measured by SE …


Comparison Of Forward And Backward Pp Pair Knockout In 3He(E,E'Pp)N, H. Baghdasaryan, L. B. Weinstein, J. M. Laget, K. P. Adhikari, M. Aghasyan, M. J. Amaryan, M. Anghinolfi, J. Ball, M. Battaglieri, A. S. Biselli, G. Dodge, C. E. Hyde, S. E. Kuhn, H. Seraydaryan Jan 2012

Comparison Of Forward And Backward Pp Pair Knockout In 3He(E,E'Pp)N, H. Baghdasaryan, L. B. Weinstein, J. M. Laget, K. P. Adhikari, M. Aghasyan, M. J. Amaryan, M. Anghinolfi, J. Ball, M. Battaglieri, A. S. Biselli, G. Dodge, C. E. Hyde, S. E. Kuhn, H. Seraydaryan

Physics Faculty Publications

Measuring nucleon-nucleon short range correlations (SRCs) has been a goal of the nuclear physics community for many years. They are an important part of the nuclear wave function, accounting for almost all of the high-momentum strength. They are closely related to the EMC effect. While their overall probability has been measured, measuring their momentum distributions is more difficult. In order to determine the best configuration for studying SRC momentum distributions, we measured the 3He(e,e'pp)n reaction, looking at events with high-momentum protons (pp > 0.35 GeV/c) and a low-momentum neutron (p …