Physical Sciences and Mathematics Commons^™

Evaluation Of Electrobraid Fencing As A Deer Barrier, Thomas W. Seamans, Zachary J. Patton, Kurt .. Vercauteren

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Increasing white-tailed deer (Odocoileus virginianus) populations in North America have lead to direct threats to public safety as well as agricultural losses. Fencing is often used to keep deer from causing damage at both airports and agricultural areas. Tall, chain-link fences have been used successfully but are often prohibitively expensive. Electric fences have potential to offer a less expensive alternative. We tested a new electric fence design marketed under the name ElectroBraid. This fence, comprised of 0.6-cm polyester rope with copper wire woven into it, is carried on frangible, fiberglass posts set at 15-m intervals. From January to …

Birdstrike Identification (Poster), Carla Dove

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Identification of feather evidence retrieved from birdstrikes provides essential information that allows airfield managers, engineers, pilots and government agencies to work together to prevent damaging birdstrikes. Knowing the identity of the birds that are causing problems is the first step in formulating a plan to discourage birds from interfering with aviation safety. The feather identification process is complex and involves cleaning feather material, microscopic examination, and whole feather comparisons with specimens in a museum collection. This poster presents the feather identification technique and provides information to various agencies on how and where to send birdstrike remains for identification.

Status Of North American Canada Goose Populations (Poster), John L. Seubert

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

North American Canada goose (Branta canadensis) populations continue to increase, causing potentially greater hazard to aviation. There is greater interest by biologist and aviation interests in monitoring the status of these populations because of the increasing number of Canada goose strikes to aircraft. Waterfowl in North America are managed in four administrative flyways – the Atlantic, Mississippi, Central, and Pacific. Goose numbers in these flyways are based on mid-winter or breeding period counts. The Canada goose count for North America in 2000 was 5,728,000—61% were the large resident geese. The resident component of the population has increased more …

Proceedings Of 4th Bird Strike Committee Usa/Canada Annual Meeting 21-24 October 2002 Sacramento, California Usa

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Abstracts

Managing Nature In Today's World, Walter E. Howard

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

The objective of my talk is to help airport authorities better understand the turmoil they encounter when managing birds and other wildlife populations. Many are reluctant to manage birds and mammals because they know that it will inevitably stir up controversy. Especially this is true when the program includes lethal means. Many people think all problems can be resolved by using non-lethal frightening devices or by live-trapping offending animals and relocating them away from airports. There are some sound arguments as to why it is biologically, ecologically and ethically proper to even use lethal means to resolve some airport wildlife …

Even With Good Equipment, Experienced Manpower Is Necessary, Nigel Horton

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Maximized efficiency and quality assurance of equipment is essential to both the manufacturer and the end-user. Quite uniquely, one UK manufacturer of bird control equipment sought the views of the aerodrome bird control staff who used it. A simple tick-box questionnaire, designed by an independent biologist, was sent to each aerodrome and 37 returned completed forms, representing about half of known users in the UK. A simple subjective analysis of these produced some unexpected results that are presented here. The survey was not dissimilar to the original trials of bird distress calls on RAF airfields undertaken during the 1960's, thus …

Avian Hazard Control In Brazil: Essential Role Of The Aeronautical Accidents Prevention And Investigation Center - Cenipa, Luiz Claudio Magalhaes Bastos

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Brazil built one of the world’s largest aeronautical infrastructures. The airport net is distributed along its vast territory, which shows a tremendous ecosystem variety. Having a large civilian aircraft fleet and also running second after Venezuela in catalogued bird species, Brazil has had problems related to bird strikes. Nevertheless, Brazil is made up of 26 States plus the Federal District. Thus, besides the Union Government, each state holds its own government structure. The states are divided into counties that also have their own administrative structure. The jurisdiction of each level of government is established by the Federal Constitution, laws and …

Assessing Bird Strike Hazards In Coastal Wetlands Through Field Experiments, John Ledbetter, John Gray

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Santa Barbara Municipal Airport (SBA) is located in and adjacent to Goleta Slough, a large coastal salt marsh with limited tidal circulation. Various government and non-government agencies are pursuing a long-term project to restore the historic tidal circulation to the slough to improve ecological conditions. SBA recently completed a study to assess feasibility of conducting a controlled field experiment in the slough to evaluate the relationship between bird strike hazards and the presence of tidal and non-tidal wetlands near the airfield. The study indicated that a limited field experiment, in which new estuarine marsh areas are temporarily restored, would provide …

Automated Haze Systems With Methyl Anthranilate Eliminate Nuisance Birds In Aviation Hangars, Warehouses, Airports, Bruce E. Vergote

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Automated haze systems (The BirdHazer) combined with Methyl Anthranilate (MA) is proven effective and cost efficient as an application method for eliminating nuisance birds in aviation hangars, warehouses, and airport facilities. Proper placement of the BirdHazer system which is based on air flow circulation allows to deliver a clean, dry haze, producing a mean droplet diameter size of 5 microns , which also eliminates the possibility of permeation and any settled residue. Three preliminary test studies were successfully completed at 2 dairy barn locations, and a salt storage warehouse. The fourth testing site was conducted at a maintenance hangar at …

Responses Of Captive Birds To Candidate Perching Deterrents On Faa Llwas Units, Michael L. Avery, Ann C. Genchi

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

Successful operation of the FAA’s Low-Level Windshear Alert System (LLWAS) depends largely on birds not perching on the wind-sensing units which are installed atop poles 40-45 m tall. Because new LLWAS units will be erected at airports throughout North America, anti- perching devices must deter numerous avian species ranging widely in body size and behavioral pattern. To determine the most promising devices, we conducted pen trials with brown-headed cowbirds, fish crows, barred owls, great horned-owls and black vultures. Birds were given free access to an unmodified sensor unit mounted on a tripod for 24 hours, during which the only alternative …

“Birdstrike” – What’S The Word? (Poster), Carla Dove

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

The word(s) “bird strike”, “bird-strike”, or “birdstrike” has been used inconsistently throughout the literature for as long as birds have been colliding with aircraft. A recent search of peer-reviewed articles in the Zoological Record and Biological Abstracts dating back to 1969 resulted in 52 articles that pertained to bird-aircraft collisions. Of those, 67% used two words (bird strike); 22% used a hyphenated word (bird-strike); 5.5% used one word (birdstrike), and 5.5% actually used both two words and the hyphenated version in the same paper! A brief glance through the proceedings and abstracts of recent Bird Strike Committee Meetings also exemplifies …

Attracting Arctic Foxes To Relocate A Gull Colony At Keflavik International Airport (Poster), Pall Hersteinsson, Gundmundur Orn Jonsson

Bird Strike Committee-USA/Canada Joint Annual Meeting: 4th (2002)

The Lesser Black-backed Gull (Larus fuscus) colony at Keflavik International Airport has grown from around 1,000 pairs in 1975 to over 20,000 pairs in the early 1990s and to around 30,000 pairs in 2000. The colony is considered a serious hazard to both military and civil air traffic. The population of arctic foxes (Alopex lagopus), the only predator in Iceland capable of preying on these gulls, was very small in this area from the late 1950s until the mid-1980s. A decade ago we noted that the location of the colony had shifted away from an arctic …

Toward Interoperability Of Mobile Agent Systems, Arne Grimstrup, Robert Gray, David Kotz, Maggie Breedy, Marco Carvalho, Thomas Cowin, Daria Chacon, Joyce Barton, Chris Garrett, Martin Hofmann

Dartmouth Scholarship

Mobile agents are an increasingly popular paradigm and in recent years there has been a proliferation of mobile-agent systems. These systems are, however, largely incompatible with each other. In particular, agents cannot migrate to a host that runs a different mobile-agent system. Prior approaches to interoperability have tried to force agents to use a common API and so far none have succeeded. This goal led to our efforts to develop mechanisms that support dynamic runtime interoperability of mobile-agent systems. This paper describes the Grid Mobile-Agent System, which allows agents to migrate to different mobile-agent systems.

Rapid Postseismic Transients In Subduction Zones From Continuous Gps, Timothy I. Melbourne, Frank H. Webb, Joann M. Stock, Christoph Reigber

All Faculty Scholarship for the College of the Sciences

Continuous GPS time series from three of four recently measured, large subduction earthquakes document triggered rapid postseismic fault creep, representing an additional moment release upward of 25% over the weeks following their main shocks. Data from two M_w = 8.0 and M_w = 8.4 events constrain the postseismic centroids to lie down dip from the lower limit of coseismic faulting, and show that afterslip along the primary coseismic asperities is significantly less important than triggered deep creep. Time series for another M_w = 7.7 event show 30% postseismic energy release, but here we cannot differentiate between afterslip …

High Frequency Gravity Waves Observed In Oh Airglow At Starfire Optical Range, Nm: Seasonal Variations In Momentum Flux, Jing Tang, Alan Z. Liu, Gary R. Swenson

Physical Sciences - Daytona Beach

Airglow imager and Na wind/temperature lidar measurements at Starfire Optical Range, New Mexico (35ºN, 107ºW) are used to estimate the seasonal variation of the vertical fluxes of horizontal momentum carried by high frequency Atmospheric Gravity Waves (AGWs). The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from the OH airglow imager data collected during 32 nights in 1998, 1999 and 2000. The RMS wind velocities were deduced from the lidar measurements. The combined information was used to estimate the upper limit of the momentum flux. The meridional component of the vertical flux of horizontal momentum was observed …

Volcanic Mound Fields On The East Pacific Rise, 16˚-19˚S: Low Effusion Rate Eruptions At Overlapping Spreading Centers For The Past 1 Myr, Scott M. White, Ken C. Macdonald, John Sinton

Faculty Publications

Volcanic mound fields identified on SeaMARC II and HMR1 12 kHz side-scan data from the southern East Pacific Rise (SEPR) occur near overlapping spreading centers (OSCs) and migration traces of OSCs. The volcanic mound fields appear as a distinctive hummocky seafloor fabric due to side-scan backscatter reflections from clusters of moundshaped reflectors. The lack of growth of the mound fields away from the ridge axis, and their occurrence in association with OSC traces, suggests that mound fields form along the ridge crest near OSCs. Volcanic mound fields are found where 120 kHz side-scan and visual observations find fields of pillow …

Environmental Controls Over Carbon Dioxide And Water Vapor Exchange Of Terrestrial Vegetation, B. E. Law, E. Falge, L. Gu, D. D. Baldocchi, P. Bakwin, P. Berbigier, K. Davis, A. J. Dolman, M. Falk, J. D. Fuentes, A. Goldstein, A. Granier, A. Grelle, D. Hollinger, I. A. Janssens, P. Jarvis, N. O. Jensen, G. Katul, K. Mahli, G. Matteucci, T. Meyers, R. Monson, W. Munger, W. Oechel, R. Olson, K. Pilegaard, K. T. Paw U, H. Thorgeirsson, R. Valentini, Shashi Verma, T. Vesala, K. Wilson, S. Wofsy

School of Natural Resources: Faculty Publications

The objective of this research was to compare seasonal and annual estimates of COM₂ and water vapor exchange across sites in forests, grasslands, crops, and tundra that are part of an international network called FLUXNET, and to investigating the responses of vegetation to environmental variables. FLUXNETs goals are to understand the mechanisms controlling the exchanges of CO₂,water vapor and energy across a spectrum of time and space scales, and to provide information for modeling of carbon and water cycling across regions and the globe. At a subset of sites, net carbon uptake (net ecosystem exchange, the net …

An Empirical Study Of Marginal Structural Models For Time-Independent Treatment, Tanya A. Henneman, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In non-randomized treatment studies a significant problem for statisticians is determining how best to adjust for confounders. Marginal structural models (MSMs) and inverse probability of treatment weighted (IPTW) estimators are useful in analyzing the causal effect of treatment in observational studies. Given an IPTW estimator a doubly robust augmented IPTW (AIPTW) estimator orthogonalizes it resulting in a more e±cient estimator than the IPTW estimator. One purpose of this paper is to make a practical comparison between the IPTW estimator and the doubly robust AIPTW estimator via a series of Monte- Carlo simulations. We also consider the selection of the optimal …

Phase And Amplitude Of Ecosystem Carbon Release And Uptake Potentials As Derived From Fluxnet Measurements, Eva Falge, John Tenhunen, Dennis D. Baldocchi, Marc Aubinet, Peter Bakwin, Paul Berbigier, Christian Bernhofer, Jean-Marc Bonnefond, George Burba, Robert Clement, Kenneth J. Davis, Jan A. Elbers, Matthias Falk, Allen H. Goldstein, Achim Grelle, Andre Granier, Thomas Grunwald, Jon Gundmondsson, David Hollinger, Ivan A. Janssens, Petri Keronen, Andrew S. Kowalski, Gabriel Katul, Beverly E. Law, Yadvinder Malhi, Tilden Meyers, Russell K. Monson, Eddy Moors, J. William Munger, Walt Oechel, Kyawtha Paw U, Kim Pilegaard, Ullar Rannik, Corinna Rebmann, Andrew E. Suyker, Halldor Thorgeirsson, Giampiero Tirone, Andrew Turnipseed, Kell Wilson, Steve Wofsy

School of Natural Resources: Faculty Publications

As length and timing of the growing season are major factors explaining differences in carbon exchange of ecosystems, we analyzed seasonal patterns of net ecosystem carbon exchange (F_NEE) using eddy covariance data of the FLUXNET data base (http://www-eosdis.ornl.gov/FLUXNET). The study included boreal and temperate, deciduous and coniferous forests, Mediterranean evergreen systems, rainforest, native and managed temperate grasslands, tundra, and C3 and C4 crops. Generalization of seasonal patterns are useful for identifying functional vegetation types for global dynamic vegetation models, as well as for global inversion studies, and can help improve phenological modules in SVAT or biogeochemical models. …

Seasonality Of Ecosystem Respiration And Gross Primary Production As Derived From Fluxnet Measurements, Eva Falge, Dennis D. Baldocchi, John Tenhunen, Marc Aubinet, Peter Bakwin, Paul Berbigier, Christian Bernhofer, George Burba, Robert Clement, Kenneth J. Davis, Jan A. Elbers, Allen H. Goldstein, Achim Grelle, Andre Granier, Jon Gundmundsson, David Hollinger, Andrew S. Kowalski, Gabriel Katul, Beverly E. Law, Yadvinder Malhi, Tilden Meyers, Russell K. Monson, J. William Munger, Walt Oechel, Kyaw Tha Paw U, Kim Pilegaard, Ullar Rannik, Corinna Rebmann, Andrew E. Suyker, Riccardo Valentini, Kell Wilson, Steve Wofsy

School of Natural Resources: Faculty Publications

Differences in the seasonal pattern of assimilatory and respiratory processes are responsible for divergences in seasonal net carbon exchange among ecosystems. Using FLUXNET data (http://www.eosdis.ornl.gov/FLUXNET) we have analyzed seasonal patterns of gross primary productivity (F_GPP), and ecosystem respiration (F_RE) of boreal and temperate, deciduous and coniferous forests, Mediterranean evergreen systems, a rainforest, temperate grasslands, and C₃ and C₄ crops. Based on generalized seasonal patterns classifications of ecosystems into vegetation functional types can be evaluated for use in global productivity and climate change models. The results of this study contribute to our understanding …

Search For R-Parity Violating Supersymmetry In Two-Muon And Four-Jet Topologies, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We present results of a search for R-parity-violating decay of the neutralino Χ̅₁⁰, taken as the lightest supersymmetric particle, to a muon and two jets. The decay proceeds through a lepton-number violating coupling λ_2jk¹ (j =1, 2; k = 1; 2, 3), with R-parity conservation in all other production and decay processes. In the absence of candidate events from 77.5 ± 3.9 pb^-1 of data collected by the D0 experiment at the Fermilab Tevatron in pp̅ collisions at√s =1.8 TeV, and with an expected background of 0.18 ± 0.03 …

Fixed Point And Two-Cycles Of The Discrete Logarithm, Joshua Holden

Mathematical Sciences Technical Reports (MSTR)

We explore some questions related to one of Brizolis: does every prime p have a pair (g, h) such that h is a fixed point for the discrete logarithm with base g? We extend this question to ask about not only fixed points but also two-cycles. Campbell and Pomerance have not only answered the fixed point question for sufficiently large p but have also rigorously estimated the number of such pairs given certain conditions on g and h. We attempt to give heuristics for similar estimates given other conditions on g and h and also in the case …

The Core Structure Of Presolar Graphite Onions, P. Fraundorf, Martin Wackenhut

Physics Faculty Works

Of the “presolar particles” extracted from carbonaceous meteorite dissolution residues, i.e., of those particles that show isotopic evidence of formation in the neighborhood of other stars prior to the origin of our solar system, a subset of the onion-like graphite spheres has an interesting concentric graphene core–graphite rim structure. We show here that single graphene sheet defects in the onion cores (e.g., cyclopentane loops) may be observable edge-on by high-resolution electron microscopy. This could allow a better evaluation of models for their formation and in particular could strengthen the possibility that growth of these assemblages proceeds atom by atom with …

Production, Outflow, Velocity, And Radial Distribution Of H2o And Oh In The Coma Of Comet C/1995 O1 (Hale-Bopp) From Wide-Field Imaging Of Oh, Walter M. Harris, Frank Scherb, Edwin Mierkiewicz, Ronald Oliversen, Jeffrey Morgenthaler

Physical Sciences - Daytona Beach

Observations of OH are a useful proxy of the water production rate (Q H2O) and outflow velocity (VH2O) in comets. From wide-field images taken on 1997 March 28 and April 8 that capture the entire scale length of the OH coma of comet C/1995 O1 (Hale-Bopp), we obtain Q OH from the model-independent method of aperture summation and Q H2O from the OH photochemical branching ratio, BROH. Using an adaptive ring summation algorithm, we extract the radial brightness distribution of OH 0-0 band emission out to cometocentric distances of up to 10 to the sixth power km, both as azimuthal …

Perpendicular Transport Of Charged Particles In Composite Model Turbulence: Recovery Of Diffusion, Gang Qin, William H. Matthaeus, John William Bieber

Aerospace, Physics, and Space Science Faculty Publications

The computation of charged particle orbits in model turbulent magnetic fields is used to investigate the properties of particle transport in the directions perpendicular to the large-scale magnetic field. Recent results by Qin, Matthaeus, & Bieber demonstrate that parallel scattering suppresses perpendicular diffusion to a subdiffusive level when the turbulence lacks transverse structure. Here numerical computations are used to show that in turbulence in which there is substantial transverse structure, a second regime of diffusive transport can be established. In both the subdiffusion regime and this "second diffusion" regime, perpendicular transport is intrinsically nonlinear. The regime of second diffusion persists …

Crystalline Order On A Sphere And The Generalized Thomson Problem, Mark Bowick, Angelo Cacciuto, David R. Nelson, A. Travesset

Physics - All Scholarship

We attack generalized Thomson problems with a continuum formalism which exploits a universal long range interaction between defects depending on the Young modulus of the underlying lattice. Our predictions for the ground state energy agree with simulations of long range power law interactions of the form 1/r^{gamma} (0 < gamma < 2) to four significant digits. The regime of grain boundaries is studied in the context of tilted crystalline order and the generality of our approach is illustrated with new results for square tilings on the sphere.

Plateau Effects In The Spectra Of Electrons Scattered From Atoms In A Strong Laser Field, N. L. Manakov, Anthony F. Starace, A. V. Flegel, M. V. Frolov

Anthony F. Starace Publications

An exact quantum solution of the problem of electron scattering from a short-range potential in the presence of a strong elliptically polarized laser field is obtained. The differential scattering cross section as a function of the number of absorbed (or emitted) photons exhibits a plateau caused by the rescattering of electrons from the scattering center. Numerical results for a linearly polarized laser field are presented, and it is shown that the plateau boundaries agree well with classical estimates.

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report, First Quarter Year 2 (March 2002 To May 2002), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) Director to the U.S. Department of Energy (DOE) as described in the UNLV AAA proposal, and Statement of Work for the First Quarter Year 2 and AAA FY02 Work Package.

The UNLV AAA UPP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies (HRC) to ensure that work conducted under the UNLV AAA UPP meets program objectives. The UNLV AAA program consists of four components: Program Support, Research Infrastructure Augmentation, International …

Ion Contribution To The Astrophysical Important 447.15, 587.56 And 667.82 Nm He I Spectral Lines Broadening, Vladimir Milosavljevic, Stevan Djenize

Articles

Characteristics of the astrophysical important Stark broadened 447.15 nm, 587.56 nm and 667.82 nm spectral line profiles have been measured at electron densities between 0.3 10 and 8.2 10 m and electron temperatures between 8000 and 33 000 K in plasmas created in five various discharge conditions using a linear, low-pressure, pulsed arc as an optically thin plasma source operated in a helium-nitrogen-oxygen gas mixture. On the basis of the observed asymmetry of the line profiles we have obtained their ion broadening parameters ( A) caused by influence of the ion microfield on the line broadening mechanism and also …

A Review Of Selected Works On Crack Indentification, Kurt M. Bryan

Mathematical Sciences Technical Reports (MSTR)

We give a short survey of some of the results obtained within the last 10 years or so concerning crack identification using impedance imaging techniques. We touch upon uniqueness results, continuous dependence results, and computational algorithms.