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2003

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Articles 2131 - 2160 of 3876

Full-Text Articles in Physical Sciences and Mathematics

Using Color-Infrared Photography And Gis To Quantify Cattail Coverage In Wetlands, H. Jeffrey Homan, Linda B. Penry, George M. Linz Feb 2003

Using Color-Infrared Photography And Gis To Quantify Cattail Coverage In Wetlands, H. Jeffrey Homan, Linda B. Penry, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

Analyzing changes in habitat features at very large scales requires digital images with both high spatial and spectral resolutions. As part of an experiment to reduce blackbird (Icterinae) damage to sunflower, we used large-scale color-infrared photography to monitor regrowth of herbicide-treated cattail (Typha spp.) in wetlands used by roosting blackbirds. In this presentation we describe the methods used to collect, convert, interpret, and analyze high resolution images.


Using Color-Infrared Photography And Gis Using Color-Infrared Photography And Gis, H. Jeffrey Homan, Linda B. Penry, George M. Linz Feb 2003

Using Color-Infrared Photography And Gis Using Color-Infrared Photography And Gis, H. Jeffrey Homan, Linda B. Penry, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

Analyzing changes in habitat features at very large scales requires digital images with both high spatial and spectral resolutions. As part of an experiment to reduce blackbird (Icterinae) damage to sunflower, we used large-scale color-infrared photography to monitor regrowth of herbicide-treated cattail (Typha spp.) in wetlands used by roosting blackbirds. In this presentation we describe the methods used to collect, convert, interpret, and analyze high resolution images.


Crop Updates - 2003 Lupins, Mark Sweetingham, Bevan J. Buirchell, Geoff Thomas, Amelia Mclarty, Harmohinder Dhammu, Martin Harries, Wayne Parker, Terry Piper, David Nicholson, Jairo Palta, Neil C. Turner, Bob French, Kedar Adhikari, Katia Stefanova, Françoise Berlandier, Glen Riethmuller, Paul Blackwell, Geoff Fosbery, Bill Crabtree, Tracy Gilham, Laurie Wahlsten, Pierre Fievez, Mike Collins, John Holmes, Dirranie Kirby, Ken Adcock, Roger Jones, Rohan Prince, Stuart Johnson, Ramon Hall, Madeleine Ball, Sofia Sipas, David Petterson Feb 2003

Crop Updates - 2003 Lupins, Mark Sweetingham, Bevan J. Buirchell, Geoff Thomas, Amelia Mclarty, Harmohinder Dhammu, Martin Harries, Wayne Parker, Terry Piper, David Nicholson, Jairo Palta, Neil C. Turner, Bob French, Kedar Adhikari, Katia Stefanova, Françoise Berlandier, Glen Riethmuller, Paul Blackwell, Geoff Fosbery, Bill Crabtree, Tracy Gilham, Laurie Wahlsten, Pierre Fievez, Mike Collins, John Holmes, Dirranie Kirby, Ken Adcock, Roger Jones, Rohan Prince, Stuart Johnson, Ramon Hall, Madeleine Ball, Sofia Sipas, David Petterson

Crop Updates

This session covers twenty one papers from different authors

LUPIN ISSUES AND R & D DIRECTIONS

  1. Mark Sweetingham, Department of Agriculture

    ACKNOWLEDGEMENTS

    VARIETIES AND BREEDING

  2. New lupin line for release – WALAN2141, Bevan J, Buirchell, Mark Sweetingham, Geoff Thomas, Amelia McLarty, Harmohinder Dhammu and CVT and Lupin Breeding teams, Department of Agriculture

  3. Lupin variety trial, Martin Harries and Wayne Parker, Department of Agriculture

  4. Herbicide tolerance of new lupins, Harmohinder S. Dhammu, Terry Piper and David Nicholson, Department of Agriculture

    YELLOW AND ALBUS LUPINS

  5. Selection for high lupin yield under terminal drought, Jairo A. Palta1&2, Neil …


Studying Byrd Glacier As A Rock-Floored Ice Stream Ending As A Calving Ice Shelf: Phase I, Terence J. Huges, Roger Hooke, James Fastook Feb 2003

Studying Byrd Glacier As A Rock-Floored Ice Stream Ending As A Calving Ice Shelf: Phase I, Terence J. Huges, Roger Hooke, James Fastook

University of Maine Office of Research Administration: Grant Reports

This award supports a one-year study of the floating part of Byrd Glacier, from its grounding line located halfway up a fjord through the Transantarctic Mountains to the end of its lateral rift zone on the Ross Ice Shelf beyond the fjord. Over this l00 km distance, the side boundary changes from rigid between the fjord sidewalls, to nearly free in the lateral rift zone, to deforming when the rifts are healed and Bryd Glacier becomes fully coupled to the Ross Ice Shelf. The stress field for these changing conditions will be calculated a using a gridpoint finite-element model for …


Particle Growth In Urban And Industrial Plumes In Texas, Charles A. Brock, Michael Trainer, Thomas B. Ryerson, J. Andrew Neuman, David D. Parrish, John S. Holloway, Dennis K. Nicks, Gregory J. Frost, Gerhard Hübler, Fred C. Fehsenfeld, J. Charles Wilson, J. Michael Reeves, Bernard G. Lafleur, Henrike Hilbert, Elliot L. Atlas, Stephen G. Donnelly Ph.D., Sue M. Schauffler, Verity R. Stroud, Christine Wiedinmyer Feb 2003

Particle Growth In Urban And Industrial Plumes In Texas, Charles A. Brock, Michael Trainer, Thomas B. Ryerson, J. Andrew Neuman, David D. Parrish, John S. Holloway, Dennis K. Nicks, Gregory J. Frost, Gerhard Hübler, Fred C. Fehsenfeld, J. Charles Wilson, J. Michael Reeves, Bernard G. Lafleur, Henrike Hilbert, Elliot L. Atlas, Stephen G. Donnelly Ph.D., Sue M. Schauffler, Verity R. Stroud, Christine Wiedinmyer

Chemistry Faculty Publications

Particle size distributions and gas-phase particle precursors and tracer species were measured aboard an aircraft in the plumes downwind from industrial and urban sources in the vicinity of Houston, TX during the daytime in late August and early September 2000. Plumes originating from the Parish gas-fired and coal-fired power plant, petrochemical industries along the Houston ship channel, the petrochemical facilities near the Gulf coast, and the urban center of Houston were studied. Most of the particle mass flux advected downwind of Houston came from the industries and electrical utilities at the periphery of the city rather than from sources in …


Towards A Performance Model For Special Purpose Orb Middleware, Venkita Subramonian, Guoliang Xing, Christopher Gill, Ron Cytron Feb 2003

Towards A Performance Model For Special Purpose Orb Middleware, Venkita Subramonian, Guoliang Xing, Christopher Gill, Ron Cytron

All Computer Science and Engineering Research

General purpose middleware has been shown effective in meeting diverse functional requirements for a wide range of distributed systems. Advanced middleware projects have also supported single quality-of-service dimensions such as real-time, fault tolerance, or small memory foot-print. However, there is limited experience supporting multiple quality-of-service dimensions in middleware to meet the needs of special purpose applications. Even though general purpose middleware can cover an entire spectrum of functionality by supporting the union of all features required by each application, this approach breaks down for distributed real-time and embedded sys-tems. For example, the breadth of features supported may interfere with small …


Trace Gas And Particle Emissions From Fires In Large Diameter And Belowground Biomass Fuels, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, R. E. Babbitt, Ronald A. Susott, Jon G. Goode, Wei Min Hao Feb 2003

Trace Gas And Particle Emissions From Fires In Large Diameter And Belowground Biomass Fuels, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, R. E. Babbitt, Ronald A. Susott, Jon G. Goode, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

[1] We adopt a working definition of residual smoldering combustion (RSC) as biomass combustion that produces emissions that are not lofted by strong fire-induced convection. RSC emissions can be produced for up to several weeks after the passage of a flame front and they are mostly unaffected by flames. Fuels prone to RSC include downed logs, duff, and organic soils. Limited observations in the tropics and the boreal forest suggest that RSC is a globally significant source of emissions to the troposphere. This source was previously uncharacterized. We measured the first emission factors (EF) for RSC in a series of …


Kinetic-Energy Release In Coulomb Explosion Of Metastable C3h52+, K. Gluch, J. Fedor, S. Matt-Leubner, Olof E. Echt, A. Stamatovic, M. Probst, P. Scheier, T. D. Mark Feb 2003

Kinetic-Energy Release In Coulomb Explosion Of Metastable C3h52+, K. Gluch, J. Fedor, S. Matt-Leubner, Olof E. Echt, A. Stamatovic, M. Probst, P. Scheier, T. D. Mark

Physics & Astronomy

C3H52+, formed by electron impact ionization of propane, undergoes metastable decay into C2H2++CH3+. We have monitored this reaction in a magnetic mass spectrometer of reversed geometry that is equipped with two electric sectors (BEE geometry). Three different techniques were applied to identify the fragment ions and determine the kinetic-energy release (KER) of spontaneous Coulomb explosion of C3H52+ in the second and third field free regions of the mass spectrometer. The KER distribution is very narrow, with a width of about 3% [root-mean square standard deviation]. An average KER of 4.58+/-0.15 eV is derived from the distribution. High level ab initio …


Optically Stimulated Luminescence Dating Supports Central Arctic Ocean Cm-Scale Sedimentation Rates, Martin Jakobsson, Jan Backman, Andrew Murray, Reidar Lovlie Feb 2003

Optically Stimulated Luminescence Dating Supports Central Arctic Ocean Cm-Scale Sedimentation Rates, Martin Jakobsson, Jan Backman, Andrew Murray, Reidar Lovlie

Center for Coastal and Ocean Mapping

This paper presents new results from Optically Stimulated Luminescence (OSL) dating on a sediment core raised from the crest of the Lomonosov Ridge in the central Arctic Ocean. There has been much debate about dating sediment cores from the central Arctic Ocean and by using an independent absolute dating technique we aim to test whether or not relatively fast, cm-scale/ka, sedimentation rates were typical of Arctic’s Pleistocene depositional mode. On the basis of mainly paleomagnetic reversal stratigraphy, many previous studies suggest mm-scale/ka sedimentation rates. A common feature in these studies is that the first down core paleomagnetic negative inclination is …


Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 11/16/02- 2/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper Feb 2003

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 11/16/02- 2/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the TRP Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral …


Review Of The Final Frontier, Michael F. Russo Feb 2003

Review Of The Final Frontier, Michael F. Russo

Faculty Publications

No abstract provided.


Driven Depinning Of Strongly Disordered Media And Anisotropic Mean-Field Limits, Alan Middleton, M. Cristina Marchetti, Karl Saunders, J. M. Schwarz Feb 2003

Driven Depinning Of Strongly Disordered Media And Anisotropic Mean-Field Limits, Alan Middleton, M. Cristina Marchetti, Karl Saunders, J. M. Schwarz

Physics - All Scholarship

Extended systems driven through strong disorder are modeled generically using coarse-grained degrees of freedom that interact elastically in the directions parallel to the driving force and that slip along at least one of the directions transverse to the motion. A realization of such a model is a collection of elastic channels with transverse viscous couplings. In the infinite range limit this model has a tricritical point separating a region where the depinning is continuous, in the universality class of elastic depinning, from a region where depinning is hysteretic. Many of the collective transport models discussed in the literature are special …


Ibd Configuration Transition Matrices And Linkage Score Tests For Unilineal Relative Pairs, Sandrine Dudoit Feb 2003

Ibd Configuration Transition Matrices And Linkage Score Tests For Unilineal Relative Pairs, Sandrine Dudoit

U.C. Berkeley Division of Biostatistics Working Paper Series

Properties of transition matrices between IBD configurations are derived for four general classes of unilineal relative pairs obtained from the grand-parent/ grand-child, half-sib, avuncular, and cousin relationships. In this setting, IBD configurations are defined as orbits of groups acting on a set of inheritance vectors. Properties of the transition matrix between IBD configurations at two linked loci are derived by relating its infinitesimal generator to the adjacency matrix of a quotient graph. The second largest eigenvalue of the infinitesimal generator and its multiplicity are key in determining the form of the transition matrix and of likelihood-based linkage tests such as …


Bogoliubov Approach To Superfluidity Of Atoms In An Optical Lattice, Ana Maria Rey, Keith Burnett, Robert Roth, Mark Edwards, Carl J. Williams, Charles W. Clark Feb 2003

Bogoliubov Approach To Superfluidity Of Atoms In An Optical Lattice, Ana Maria Rey, Keith Burnett, Robert Roth, Mark Edwards, Carl J. Williams, Charles W. Clark

Department of Physics and Astronomy Faculty Publications

We use the Bogoliubov theory of atoms in an optical lattice to study the approach to the Mott-insulator transition. We derive an explicit expression for the superfluid density based on the rigidity of the system under phase variations. This enables us to explore the connection between the quantum depletion of the condensate and the quasi-momentum distribution on the one hand and the superfluid fraction on the other. The approach to the insulator phase may be characterized through the filling of the band by quantum depletion, which should be directly observable via the matter–wave interference patterns. We complement these findings by …


Examination Of The Role Of The Clamp-Loader And Atp Hydrolysis In The Formation Of The Bacteriophage T4 Polymerase Holoenzyme, Michael A. Trakselis, Anthony J. Berdis, Stephen J. Benkovic Feb 2003

Examination Of The Role Of The Clamp-Loader And Atp Hydrolysis In The Formation Of The Bacteriophage T4 Polymerase Holoenzyme, Michael A. Trakselis, Anthony J. Berdis, Stephen J. Benkovic

Chemistry Faculty Publications

Transient kinetic analyses further support the role of the clamp-loader in bacteriophage T4 as a catalyst which loads the clamp onto DNA through the sequential hydrolysis of two molecules of ATP before and after addition of DNA. Additional rapid-quench and pulse-chase experiments have documented this stoichiometry. The events of ATP hydrolysis have been related to the opening/closing of the clamp protein through fluorescence resonance energy transfer (FRET). In the absence of a hydrolysable form of ATP, the distance across the subunit interface of the clamp does not increase as measured by intramolecular FRET, suggesting gp45 cannot be loaded onto DNA. …


Twinscan: A Software Package For Homology-Based Gene Prediction, Paul Flicek Feb 2003

Twinscan: A Software Package For Homology-Based Gene Prediction, Paul Flicek

All Computer Science and Engineering Research

A complete mapping from genome to proteome would constitute a foundation for genome-based biology and provide targets for pharmaceutical and therapeutic intervention. This is one reason gene structure prediction has been a major subfield of computational biology for over 20 years. Many of the widely used gene prediction systems were developed in the 1990s and are unable to take advantage of the revolution in comparative genomics brought on by the sequencing of the entire genomes of an increasing numbers of vertebrates. Twinscan is a new system for high-throughput gene-structure prediction that exploits the patterns of conservation observed in alignments between …


Trace Gas Emissions From The Production And Use Of Domestic Biofuels In Zambia Measured By Open-Path Fourier Transform Infrared Spectroscopy, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, Ted J. Christian, Wei Min Hao Feb 2003

Trace Gas Emissions From The Production And Use Of Domestic Biofuels In Zambia Measured By Open-Path Fourier Transform Infrared Spectroscopy, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, Ted J. Christian, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

[1] Domestic biomass fuels (biofuels) were recently estimated to be the second largest source of carbon emissions from global biomass burning. Wood and charcoal provide approximately 90% and 10% of domestic energy in tropical Africa. In September 2000, we used open-path Fourier transform infrared (OP-FTIR) spectroscopy to quantify 18 of the most abundant trace gases emitted by wood and charcoal cooking fires and an earthen charcoal-making kiln in Zambia. These are the first in situ measurements of an extensive suite of trace gases emitted by tropical biofuel burning. We report emission ratios (ER) and emission factors (EF) for (in order …


Baiting Blackbirds (Icteridae) In Stubble Grain Fields During Spring Migration In South Dakota, G. M. Linz, G.A. Knutsen, H.J. Homan, W.J. Bleier Feb 2003

Baiting Blackbirds (Icteridae) In Stubble Grain Fields During Spring Migration In South Dakota, G. M. Linz, G.A. Knutsen, H.J. Homan, W.J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

Blackbirds (Icteridae) annually damage US$5–8 million of ripening sunflower in the northern Great Plains. Baiting blackbirds with avicide-treated rice during spring migration might reduce the regional breeding population. In March and April 1996–1997, we simulated a baiting program in eastern South Dakota to compare attractiveness of rice-baited plots placed in fields of corn and soybean stubble. Blackbirds used plots in corn stubble more often than plots in soybean stubble and chose rice-baited plots over unbaited reference plots. We conclude that blackbirds can be successfully baited with avicide-treated rice placed in corn stubble. Copyright 2002 Elsevier Science Ltd. All rights reserved.


Energy‐Constrained Open‐System Magmatic Processes Iv: Geochemical, Thermal And Mass Consequences Of Energy‐Constrained Recharge, Assimilation And Fractional Crystallization (Ec‐Rafc), Wendy A. Bohrson, Frank J. Spera Feb 2003

Energy‐Constrained Open‐System Magmatic Processes Iv: Geochemical, Thermal And Mass Consequences Of Energy‐Constrained Recharge, Assimilation And Fractional Crystallization (Ec‐Rafc), Wendy A. Bohrson, Frank J. Spera

All Faculty Scholarship for the College of the Sciences

A wealth of geochemical and petrological data provide evidence that the processes of fractional crystallization, assimilation, and magma recharge (replenishment) dominate the chemical signatures of many terrestrial igneous rocks. Previous work [Spera and Bohrson, 2001; Bohrson and Spera, 2001] has established the importance of integrating energy, species and mass conservation into simulations of complex magma chamber processes. An extended version of the energy‐constrained formulation, Energy‐Constrained Recharge, Assimilation, Fractional Crystallization (EC‐RAFC), tracks mass and compositional variations of melt, cumulates, and enclaves in a magma body undergoing simultaneous recharge, assimilation, and fractional crystallization [Spera and Bohrson, 2002]. …


Privacy-Enhanced Credential Services, Alex Iliev, Sean Smith Feb 2003

Privacy-Enhanced Credential Services, Alex Iliev, Sean Smith

Computer Science Technical Reports

The use of credential directories in PKI and authorization systems such as Shibboleth introduces a new privacy risk: an insider at the directory can learn much about otherwise protected interactions by observing who makes queries, and what they ask for. Recent advances in Practical Private Information Retrieval provide promising countermeasures. In this paper, we extend this technology to solve this new privacy problem, and present a design and preliminary prototype for a LDAP-based credential service that can prevent even an insider from learning anything more than the fact a query was made. Our preliminary performance analysis suggests that the complete …


Keyjacking: Risks Of The Current Client-Side Infrastructure, John Marchesini, S W. Smith, Meiyuan Zhao Feb 2003

Keyjacking: Risks Of The Current Client-Side Infrastructure, John Marchesini, S W. Smith, Meiyuan Zhao

Computer Science Technical Reports

In theory, PKI can provide a flexible and strong way to authenticate users in distributed information systems. In practice, much is being invested in realizing this vision via client-side SSL and browser-based keystores. Exploring this vision, we demonstrate that browsers will use personal certificates to authenticate requests that the person neither knew of nor approved (and which password-based systems would have defeated), and we demonstrate the easy permeability of these keystores (including new attacks on medium and high-security IE/XP keys). We suggest some countermeasures, but also suggest that a fundamental rethinking of the trust, usage, and storage model might result …


Rank Regression In Stability Analysis, Ying Qing Chen, Annpey Pong, Biao Xing Feb 2003

Rank Regression In Stability Analysis, Ying Qing Chen, Annpey Pong, Biao Xing

U.C. Berkeley Division of Biostatistics Working Paper Series

Stability data are often collected to determine the shelf-life of certain characteristics of a pharmaceutical product, for example, a drug's potency over time. Statistical approaches such as the linear regression models are considered as appropriate to analyze the stability data. However, most of these regression models in both theory and practice rely heavily on their underlying parametric assumptions, such as normality of the continuous characteristics or their transformations. In this article, we propose and study some rank-based regression procedures for the stability data when the linear regression models are semiparametric with unspecified error structure. Numerical studies including Monte Carlo simulations …


Dissociative Electron Attachment Near Threshold, Thermal Attachment Rates, And Vertical Attachment Energies Of Chloroalkanes, Gordon A. Gallup, Kayvan Aflatooni, Paul Burrow Feb 2003

Dissociative Electron Attachment Near Threshold, Thermal Attachment Rates, And Vertical Attachment Energies Of Chloroalkanes, Gordon A. Gallup, Kayvan Aflatooni, Paul Burrow

Paul Burrow Publications

The peaks appearing near zero energy in the dissociative electron attachment cross section of 18 chloroalkanes are studied by electron beam methods. Fits to the experimental data are made using model cross sections having appropriate energy dependences and inclusion of the broadening due to the electron energy distribution. The magnitudes of the zero peaks are found to be well correlated with the vertical attachment energies (VAE) associated with occupation of the lowest empty orbitals of the compounds. The magnitudes rise exponentially by more than five orders of magnitude as VAE decreases from 2 eV to a slightly negative value. This …


Semiclassical Dynamics With Quantum Trajectories: Formulation And Comparison With The Semiclassical Initial Value Representation Propagator, Sophya Garashchuk, Vitaly A. Rassolov Feb 2003

Semiclassical Dynamics With Quantum Trajectories: Formulation And Comparison With The Semiclassical Initial Value Representation Propagator, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

We present a time-dependent semiclassical method based on quantum trajectories. Quantum-mechanical effects are described via the quantum potential computed from the wave function density approximated as a linear combination of Gaussian fitting functions. The number of the fitting functions determines the accuracy of the approximate quantum potential (AQP). One Gaussian fit reproduces time-evolution of a Gaussian wave packet in a parabolic potential. The limit of the large number of fitting Gaussians and trajectories gives the full quantum-mechanical result. The method is systematically improvable from classical to fully quantum. The fitting procedure is implemented as a gradient minimization. We also compare …


Backscattering Of An Intense Laser Beam By An Electron, Fei He, Y.Y. Lau, Donald P. Umstadter, Richard Kowalczyk Feb 2003

Backscattering Of An Intense Laser Beam By An Electron, Fei He, Y.Y. Lau, Donald P. Umstadter, Richard Kowalczyk

Donald Umstadter Publications

We present a novel, simple asymptotic expansion for the spectrum of radiation that is backscattered from a laser by a counterpropagating (or copropagating) electron. The solutions are presented in such a way that they explicitly show the relative merit of using an intense laser and of an energetic electron beam in x-ray production in the single particle regime. Simple scaling laws are given.


Bounding The Number Of Graphs Containing Very Long Induced Paths, Steven Kay Butler Feb 2003

Bounding The Number Of Graphs Containing Very Long Induced Paths, Steven Kay Butler

Theses and Dissertations

Induced graphs are used to describe the structure of a graph, one such type of induced graph that has been studied are long paths.

In this thesis we show a way to represent such graphs in terms of an array with two colors and a labeled graph. Using this representation and the techniques of Polya counting we will then be able to get upper and lower bounds for graphs containing a long path as an induced subgraph.

In particular, if we let P(n,k) be the number of graphs on n+k vertices which contains P_n, a path on n vertices, as …


Potential Impact Of Subsonic And Supersonic Aircraft Exhaust On Water Vapor In The Lower Stratosphere Assessed Via A Trajectory Model, Gary A. Morris, Joan A. Rosenfield, Mark R. Schoeberl, Charles A. Jackman Feb 2003

Potential Impact Of Subsonic And Supersonic Aircraft Exhaust On Water Vapor In The Lower Stratosphere Assessed Via A Trajectory Model, Gary A. Morris, Joan A. Rosenfield, Mark R. Schoeberl, Charles A. Jackman

Physics and Astronomy Faculty Publications

We employ a trajectory model to assess the impact on the stratosphere of water vapor present in the exhaust of subsonic and a proposed fleet of supersonic aircraft. Air parcels into which water vapor from aircraft exhaust has been injected are run through a 6-year simulation in the trajectory model using meteorological data from the UKMO analyses with emissions dictated by the standard 2015 emissions scenario. For the subsonic aircraft, our results suggest maximum enhancements of ~150 ppbv just above the Northern Hemisphere tropopause and of much less than 50 ppbv in most other regions. Inserting the perturbed water vapor …


University Of Nevada, Las Vegas Transmutation Research Program: Quarterly Report, Second Quarter Year 2 (June 2002 To August 2002), Anthony Hechanova Feb 2003

University Of Nevada, Las Vegas Transmutation Research Program: Quarterly Report, Second Quarter Year 2 (June 2002 To August 2002), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Transmutation Research Program (TRP) Director to the U.S. Department of Energy (DOE) as described in the UNLV Advanced Accelerator Applications (AAA) proposal, and AAA FY02 Work Package. Note: during this quarter, the AAA national program changed names to the Advanced Fuel Cycle Initiative (AFCI) and the UNLV AAA University Participation Program changed its name to the Transmutation Research Program. The new names will be used in future references.

The TRP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies …


Observation Of The Strange Sea In The Proton Via Inclusive Φ-Meson Production In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock Feb 2003

Observation Of The Strange Sea In The Proton Via Inclusive Φ-Meson Production In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock

Faculty Publications

Inclusive φ(1020)-meson production in neutral current deep inelastic e+p scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 45 pb-1. The φ mesons were studied in the range 10 < Q2 < 100 GeV2, where Q2 is the virtuality of the exchanged photon, and in restricted kinematic regions in the transverse momentum, pT, pseudorapidity, η, and the scaled momentum in the Breit frame, xp. Monte Carlo models with the strangeness-suppression factor as determined by analyses of e+e- annihilation events overestimate the cross sections. A smaller value of the strangeness-suppression factor reduces the predicted cross sections, but fails to reproduce the shapes of the measured differential cross sections. High-momentum φ mesons in the current region of the Breit frame give the first direct evidence for the strange sea in the proton at low x. © 2002 Published by Elsevier Science B.V.


Observational Constraints On General Relativistic Energy Conditions, Cosmic Matter Density And Dark Energy From X-Ray Clusters Of Galaxies And Type-La Supernovae, P. Schuecker, R. R. Caldwell, H. Böhringer, C. A. Collins Feb 2003

Observational Constraints On General Relativistic Energy Conditions, Cosmic Matter Density And Dark Energy From X-Ray Clusters Of Galaxies And Type-La Supernovae, P. Schuecker, R. R. Caldwell, H. Böhringer, C. A. Collins

Dartmouth Scholarship

New observational constraints on the cosmic matter density Ωm and an effectively redshift-independent equation

of state parameter wx of the dark energy are obtained while simultaneously testing the strong and null energy conditions of

general relativity on macroscopic scales. The combination of REFLEX X-ray cluster and type-Ia supernova data shows that

for a flat Universe the strong energy condition might presently be violated whereas the null energy condition seems to be

fulfilled. This provides another observational argument for the present accelerated cosmic expansion and the absence of exotic

physical phenomena related to a broken null energy condition. The marginalization of …