Physical Sciences and Mathematics Commons^™

Density Profile And Flow Of Miscible Fluid With Dissimilar Constituent Masses, Ras B. Pandey, D. Stauffer, R. Seyfarth, Luis A. Cueva, J.F. Gettrust, Warren Wood

Faculty Publications

A computer simulation model is used to study the density profile and flow of a miscible gaseous fluid mixture consisting of differing constituent masses (m(A) = m(B)/3) through an open matrix. The density profile is found to decay with the height proportional to exp(-m(A(B))h), consistent with the barometric height law. The flux density shows a power-law increase proportional to (p(c) - p)(a) with mu similar or equal to 2.3 at the porosity 1 - p above the pore percolation threshold 1 - p(c). (C) 2002 Elsevier Science B.V. All rights reserved.

Electrical Conductivity And Thermopower Of Cu–Sio[Sub 2] Nanogranular Films., W. Chen, J. Lin, X. Zhang, H. Shin, Jeffrey Dyck, C. Uher

Jeffrey Dyck

We have measured the thermopower S and electrical conductivity σ in a series of Cu[sub x](SiO[sub 2])[sub 1-x] nanogranular films between 2 and 300 K with Cu volume fraction x varying from 0.43 up to 1.0. At low temperatures, disorder-enhanced electron-electron interaction effects dictate the behavior of σ. A crossover of the temperature dependence from σ∝ √T to σ∝ T[sup 1/3] is observed as x is lowered and the metal-insulator transition is approached. S is small, shows linear temperature dependence, and is rather insensitive to the change of x. Effects of annealing are also discussed.

Highly Anisotropic Crystal Growth And Thermoelectric Properties Of K2bi8_Xsbxse13 Solid Solutions: Band Gap Anomaly At Low X, Jeffrey S. Dyck, Theodora Kyratsi, Wei Chan, Duck-Young Chung, Ctirad Uher, Konstantinos Paraskevopoulos, Mercouri Kanatzidis

Jeffrey Dyck

The thermoelectric properties of solid solutions of the type B -K2Bi8_xSbxSe13 (0

Geomorphic Effectiveness, Sandur Development, And The Pattern Of Landscape Response During Jökulhlaups: Skeiöarársandur, Southeastern Iceland, F. J. Magilligan, B. Gomez, L. A. K. Mertes, L. C. Smith, Norman D. Smith, D. Finnegan, J. B. Garvin

Department of Earth and Atmospheric Sciences: Faculty Publications

By contrast with other historical outburst floods on Skeióarársandur, the 1996 jökulhlaup was unprecedented in its magnitude and duration, attaining a peak discharge of ~53,000 m³/s in <17 h. Using a combination of field sampling and remote sensing techniques (Landsat TM, SAR interferometry, airphotos, and laser altimetry), we document the sandur-wide geomorphic impacts of this event. These impacts varied widely across the Skeióarársandur and cannot be singularly attributed to jökulhlaup magnitude because pre-jökulhlaup glacial dynamics and the extant setting largely conditioned the spatial pattern, type, and magnitude of these impacts. Topographic lowering and asymmetric retreat of the ice front during the late twentieth century has decoupled the ice sheet from the moraine/sandur complex along the central and western sandur. This glacial control, in combination with the convex topography of the proximal sandur, promoted a shift from a primarily diffuse-source braided outwash system to a more point-sourced, channelized discharge of water and sediment. Deposition dominated within the proglacial depression, with approximately 3.8*10⁷ m³ of sediment, and along channel systems that remained connected to subglacial sediment supplies. This shift to a laterally dissimilar, channelized routing system creates a more varied depositional pattern that is not explicitly controlled by the concave longitudinal profile down-sandur. Laterally contiguous units, therefore, may vary greatly in age and sediment character, suggesting that current facies models inadequately characterize sediment transfers when the ice front is decoupled from its …

The Mount Feather Diamicton Of The Sirius Group: An Accumulation Of Indicators Of Neogene Antarctic Glacial And Climatic History, G. A. Wilson, J. A. Barron, A. C. Ashworth, R. A. Askin, J. A. Carter, M. G. Curren, D. H. Dalhuisen, E. I. Friedmann, D. G. Fyodorov-Davidov, D. A. Gilichinsky, M. A. Harper, David M. Harwood, J. F. Hiemstra, T. R. Janecek, K. J. Licht, V. E. Ostroumov, R. D. Powell, E. M. Rivkina, S. A. Rose, A. P. Stroeven, P. Stroeven, J. J. M. Van Der Meer, M. C. Wizevich

Department of Earth and Atmospheric Sciences: Faculty Publications

A paucity of data from the Antarctic continent has resulted in conflicting interpretations of Neogene Antarctic glacial history. Much of the debate centres on interpretations of the glacigene Sirius Group strata that crop out as discrete deposits along the length of the Transantarctic Mountains and in particular on its age and the origin of the siliceous microfossils it encloses. Pliocene marine diatoms enclosed within Sirius Group strata are inferred to indicate a dynamic East Antarctic ice sheet that was much reduced, compared with today, in the early-middle Pliocene and then expanded again in the late Pliocene. However, the geomorphology of …

Band Structure Of Strained Gd(0001) Films, I. N. Yakovkin, Takashi Komesu, Peter A. Dowben

Peter Dowben Publications

The electronic structure of strained and unstrained Gd(0001) surfaces has been studied both theoretically and experimentally with spin-polarized photoemission spectroscopy and spin-polarized inverse photoemission spectroscopy. Good agreement between calculated surface bands and surface-induced features of the spectra provides the basis for a more detailed explanation of the origin of the spin-polarized bands than was previously possible. It has been found that observed relaxation of the expansively strained in-plane crystal lattice constant, of Gd(0001) on Mo(112), significantly affects the electronic structure of the surface.

A Comparison Of Haloe V19 With Sage Ii V6.00 Ozone Observations Using Trajectory Mapping, Gary A. Morris, James F. Gleason, James M. Russell Iii, Mark R. Schoeberl, M. Patrick Mccormick

Physics and Astronomy Faculty Publications

We apply trajectory mapping to an 8-year intercomparison of ozone observations from the Halogen Occultation Experiment (HALOE) (V19) and Stratospheric Aerosol and Gas Experiment (SAGE) II (V6.00) for the months March, May, June, September, October, and December from the period December 1991 to October 1999. Our results, which represent the most extensive such intercomparison of these two data sets to date, suggest a root-mean-square difference between the two data sets of >15% below 22 km in the tropics and of 4–12% throughout most of the rest of the stratosphere. In addition, we find a bias with HALOE ozone low relative …

Evaluation Of Flight Control® To Reduce Blackbird Damage To Newly Planted Rice In Louisiana, John L. Cummings, Patricia A. Pochop, Richard M. Engeman, James E. Davis Jr., Thomas M. Primus

United States Department of Agriculture Wildlife Services: Staff Publications

Blackbirds cause extensive damage to newly planted and ripening rice. To date there is not a registered bird repellent for reducing this damage. We evaluated Flight Control®, a 50% anthraquinone product, as a potential repellent to blackbirds in cage and field tests in Louisiana. In one- and no-choice cage tests, brown-headed cowbird and red-winged blackbird consumption of 2%) Flight control® treated rice seed was significantly reduced. In a subsequent field test. 2% Flight control® was effective in reducing blackbird damage (P = 0.001 ) to newly planted rice seed. Chemical residues at 7 days post-planting averaged 0.66% anthraquinone. Further …

Potential Hazards Of Drc- 1339 Treated Rice To Non-Target Birds When Used At Roost Staging Areas In Louisiana To Reduce Local Populations Of Depredating Blackbirds, John L. Cummings, James F. Glahn, E. Allen Wilson, James E. Davis Jr.

United States Department of Agriculture Wildlife Services: Staff Publications

Hazards of DRC-1339 treated brown rice to non-target birds were assessed during an operational baiting program near Point Blue, Louisiana, USA. The predominant non-target birds using DRC-1339 bait sites and surrounding habitat were savannah sparrows (Passerculus sandwichensis), mourning doves (Zenaida macroura), killdeers (Charadrius rociferus), and unidentified sparrows (Fringillidae). Systematic searches of DRC-1339 bait sites and adjacent habitat for non-target dead or affected birds produced 1 northern cardinal (Cardinalis cardinalis). There was no mortality of potential non-target species, savannah sparrows, white-crown sparrows (Zonotrichia leucophrys), field sparrows (Spizella pusilla …

Thamnophis Radix (Plains Garter Snake) Brood Size, Richard M. Engeman, Isabel M. Engeman, Alexander N. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Brood sizes for Thamnophis radix show much geographical variation (Fitch 1985. Misc. Publ. Univ. Kansas Mus. Nat. Hist. 76:l- 76). While brood sizes can range up to 60 (Fitch, up. cit.; Collins 1993. Amphibians and Reptiles in Kansas. Univ. Kansas Mus. Nat. Hist., Lawerence, Kansas, 397 pp.), the brood sizes reported for Colorado have fallen far short of this. Hammerson (1999. Amphibians and Reptiles in Colorado, Second Edition. University Press of Colorado, Niwot, Colorado, 480 pp.) observed brood sizes in Colorado of 16-21 (N = 9), with a mean of 16. Rossman et al. (1996. The Garter Snakes: Evolution and …

Seasonal Marking Efficacy Of Dupont Oil Blue A Dye On Steam-Rolled Oat Groat Baits For Valley Pocket Gophers, Craig A. Ramey, George H. Matschke, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

We examined if Valley pocket gophers (Thomomys bottae) exhibited a seasonal preference for consuming steamed-rolled oat (SRO) groat bait treated with 1.6% Dupont oil blue A (fat-marking dye). Field tests were conducted in California alfalfa fields during winter, summer, and fall, and in walnut orchards during winter and summer. Five treatment units (TUs) were established each with 60 burrows for each season and habitat studied during 1997–1999. SRO groat marker bait (4 g) was placed inside each active burrow. All bait sites were re-opened about 96 h later and examined for the presence (all or some) or absence …

Safe Efficacy Of Three Strychnine Alkaloid Bait Concentrations For Hand-Baiting Control Of Plains Pocket Gophers, Craig A. Ramey, George H. Matschke, Paul L. Hegdal, Geraldine R. Mccann, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

In November 1990, field efficacy studies using milo baits formulated with 0.35%, 0.75%, or 1.30% strychnine alkaloid were compared to a placebo (0.0% strychnine) for controlling plains pocket gophers (Geomys bursarius) near Pleasanton, Texas. These data were required by the US Environmental Protection Agency (EPA) as partial fulfillment for the maintenance of the rodenticide registrations of the US Department of Agriculture. Each of four treatment units (TUs) within a block (2) was randomly assigned one of the four baits. Within each TU, 15 gophers were captured (balanced roughly for gender) and instrumented with radio transmitters. Following a pretreatment …

Content Aware Request Distribution For High Performance Web Service: A Performance Study, Robert M. Jones

Dissertations and Theses

The World Wide Web is becoming a basic infrastructure for a variety of services, and the increases in audience size and client network bandwidth create service demands that are outpacing server capacity. Web clusters are one solution to this need for high performance, highly available web server systems. We are interested in load distribution techniques, specifically Layer-7 algorithms that are content-aware. Layer-7 algorithms allow distribution control based on the specific content requested, which is advantageous for a system that offers highly heterogenous services. We examine the performance of the Client Aware Policy (CAP) on a Linux/Apache web cluster consisting of …

Pumping Or Mixing System Using A Levitating Magnetic Element, Aexandre N. Terentiev

Physics and Astronomy Faculty Patents

A system capable of pumping or mixing relatively warm fluids using a rotating magnetic element or bearing levitated by a cold superconducting element is disclosed. The magnetic element or bearing carries at least one impeller and is placed in a fluid vessel positioned external to the outer wall of a cryostat or other housing for the superconducting element. A separate cooling source thermally linked to the superconducting element provides the necessary cooling to create the desired superconductive effects and induce levitation in the magnetic element or bearing. The outer wall or housing defines a chamber around the cold superconducting element …

Large Force Fluctuations In A Flowing Granular Medium, Emily Longhi, Nalini Easwar, Narayanan Menon

Physics: Faculty Publications

We study fluctuations in the force at the boundary of a 2D granular flow. The forces are mainly impulsive at all flow rates. The probability distribution of impulses decays exponentially at large impulses, as do the forces in a static granular medium. At small impulses, the distribution evolves continuously with flow rate with no indication of the transition from collisional flow to intermittently jamming flows. However, the distribution of the time interval between collisions tends to a power law, P(τ)∼τ−3/2, showing a clear dynamical signature of the approach to jamming.

Central Twisted Transformation Groups And Group C*-Algebras Of Central Group Extensions, Siegfried Echterhoff, Dana P. Williams

Dartmouth Scholarship

We examine the structure of central twisted transformation group C∗-algebras C0(X) ⋊id,u G, and apply our results to the group C ∗-algebras of central group extensions. Our methods require that we study Moore’s cohomology group H2 (G, C(X,T)), and, in particular, we prove an inflation result for pointwise trivial cocyles which may be of use elsewhere.

Comparison Of Heat Output And Microchemical Changes Of Palladium Cathodes Under Electrolysis In Acidified Light And Heavy Water, Conrado Salas Cano

Dissertations and Theses

Two experiments have been conducted to ascertain if a cell with a palladium cathode, a platinum anode, and a solution of H₂SO₄ in D₂O can produce excess heat under electrolysis compared to a similar cell with H₂O. In each experiment, two cells were connected in series with constant current. The two cells were identical except for the fact that the heavy water cell used D₂O instead of H₂O in the electrolyte. Both cells in each experiment employed Pd cathodes, Pt anodes, and H₂SO₄ in the solution. …

Wildlife Damage Management Research Needs: Perceptions Of Scientists, Wildlife Managers, And Stakeholders Of The Usda/Wildlife Services Program, Richard L. Bruggers, Richard Owens, Thomas Hoffman

United States Department of Agriculture Wildlife Services: Staff Publications

This paper presents the results of a nationwide research needs assessment of the important wildlife-human conflict issues and associated research needs of the USDA:APHIS-Wildlife Services (WS) program and its stakeholders. Thirty-six WS State Directors, 23 WS/National Wildlife Research Center (NWRC) scientists and 6 members of the National Wildlife Services Advisory Committee (NWSAC) to the US Secretary of Agriculture responded to a request for participation. This paper compares these current research needs with previous regional and national research needs assessments for wildlife damage management in the United States. Important national problems identified included issues related to aviation, timber, agriculture, aquaculture, and …

Sustained Evaluation Of The Effectiveness Of Detector Dogs For Locating Brown Tree Snakes In Cargo Outbound From Guam, Richard M. Engeman, Daniel S. Vice, Darryl York, Kenneth S. Gruver

United States Department of Agriculture Wildlife Services: Staff Publications

The accidental introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island's native terrestrial vertebrates, has created a health hazard to infants and children, and has resulted in economic losses. The high brown tree snake population densities on Guam, the species' adaptations for successful dispersal, and Guam's position as a focal point for commercial and military cargo shipments have created a high level of concern that brown tree snakes could spread from Guam to colonize other vulnerable locations. Cargo inspections using teams of handlers and their detector dogs …

Estimating Deer Damage Losses In Cabbage, Richard M. Engeman, Brian K. Maedke, Scott F. Beckerman

United States Department of Agriculture Wildlife Services: Staff Publications

A standardized procedure for estimating deer damage in cabbage is used to settle claims for compensation of losses in the state of Wisconsin. By completely enumerating all damaged heads of cabbage in a field. We validated the standard procedure for accuracy. The general paradigm used for assessing losses requires a subjective examination of the field to define strata with and without damage, obtaining representative samples of undamaged heads in each strata with 3 quadrants. then converting the difference in density of undamaged heads between strata into an estimate of damage for the entire field. Weighing a sample of undamaged heads …

Beginning A New Era Of Drought Monitoring Across North America, Jay Lawrimore, Richard R. Heim Jr., Mark D. Svoboda, Val Swail, Phil J. Englehart

Drought Mitigation Center: Faculty Publications

Drought experts from the United States, Canada, and Mexico met at the National Climatic Data Center in Asheville, North Carolina, for a three-day workshop in late April 2002 to discuss the U.S. Drought Monitor program and to develop a plan for initiating a new program of drought monitoring for North America. Since its inception in 1999, the U.S. Drought Monitor (DM) has been extremely successful in assessing and communicating the state of drought in the United States on a weekly basis. This success, and the recognition that an ongoing comprehensive and integrated drought assessment was needed throughout all three countries, …

The Virginia Wetlands Report Vol. 17, No. 2, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Hellgrammites and Their Relatives. Rebecca Jo Thomas
• Book Review Wetlands Explained. Walter I. Priest, III
• GPS Technology Lends Support to the Marsh Project. Marcia Berman and Harry Berquist
• Phragmites australis (Reed Grass) Bane or Beneficence? Kirk Havens
• Impacts of Sea Level Rise Studied in Pamunkey River Marshes. Carl Hershner
• Worldwide Shrimp Farming and Mangrove Wetland Losses: Are the Two Irrevocably Linked? Pam Mason

Challenges, Strategies, And Tools For Research Scientists: Using Web-Based Information Resources, Danielle Bodrero Hoggan

E-JASL 1999-2009 (Volumes 1-10)

Scientists face many challenges in harnessing web-based resources. Information overload, misinformation, fees, poorly designed navigation, and loss of browsability all hamper the scientist searcher. In addition, many scientists rely on only one or two databases and often miss unique information that is available through other sources. Librarians can team up with scientists to develop strategies to overcome the challenges of web-based information. For example, a librarian can teach effective information seeking techniques, including how to use controlled vocabularies, how to evaluate information on the web, and how to complement web-based resources with print resources. Librarians can also help scientists to …

An Ecological Basis For Managing Giant Sequoia Ecosystems, Douglas D. Piirto, Robert R. Rogers

Natural Resources Management and Environmental Sciences

A strategy for management of giant sequoia groves is formulated using a conceptual framework for ecosystem management recently developed by Region Five of the USDA Forest Service. The framework includes physical, biological, and social dimensions. Environmental indicators and reference variability for key ecosystem elements are discussed in this paper. The selected ecosystem elements include: 1) attitudes, beliefs, and values; 2) economics and subsistence; 3) stream channel morphology; 4) sediment; 5) water; 6) fire; 7) organic debris; and 8) vegetation mosaic. Recommendations are made for the attributes of environmental indicators that characterize these elements. These elements and associated indicators will define …

Autoregressive Moving Average Models Of Crown Profiles For Two California Hardwood Species, Samantha J. Gill, Gregory S. Biging

Natural Resources Management and Environmental Sciences

Time-series Autoregressive Moving Average (ARMA) models were employed to model tree crown profiles for two California hardwood species (blue oak and interior live oak). There are three major components of these models: a polynomial trend, an ARMA model, and unaccounted for variation. The polynomial trend was used to achieve a stationary series. For these crown profiles, the use of a quadratic trend resulted in a stationary series for 60% of the profiles. A cubic trend was used for another 23%, and a quartic for 7%. It was found that 80% of the tree crown profiles could be modeled using a …

Asymmetries Between Strange And Antistrange Particle Production In Pion–Proton Interactions, Thomas D. Gutierrez, R. Vogt

Physics

Recent measurements of the asymmetries between Feynman x distributions of strange and antistrange hadrons in ∏−A interactions show a strong effect as a function of xn_F. We calculate strange hadron production in the context of the intrinsic model and make predictions for particle/antiparticle asymmetries in these interactions.

Circulation, Vol. 9, No. 1, Center For Coastal Physical Oceanography, Old Dominion University, Richard Moody

CCPO Circulation

Summer 2002 issue of CCPO Circulation featuring article "Workshop Promotes Safe Navigation, Training for Marine Pilots" by Richard Moody

The Physical Conditions Within Dense Cold Clouds In Cooling Flows - Ii, Gary J. Ferland, A. C. Fabian, R. M. Johnstone

Physics and Astronomy Faculty Publications

This is a progress report on our numerical simulations of conditions in the cold cores of cooling flow condensations. The physical conditions in any non-equilibrium plasma are the result of a host of microphysical processes, many involving reactions that are research areas in themselves. We review the dominant physical processes in our previously published simulations, to clarify those issues that have caused confusion in the literature. We show that conditions in the core of an X-ray-illuminated cloud are very different from those found in molecular clouds, largely because carbon remains substantially atomic and provides powerful cooling through its far infrared …

The Probe, Issue 223 – July/August 2002

The Probe: Newsletter of the National Animal Damage Control Association

• Suburban Invasion! By Wildlife? -- Michelle L. Shuey, Southwest Texas State University
• What are the health risks of consuming meat from deer or elk infected with Chronic Wasting Disease ?
• The 68th North American Wildlife and Natural Resources Conference is set for March 26-30, 2003, in Winston-Salem, North Carolina
• Book Review: Living in the Shadows: How to Help the Stray Cat in Your Life (Without Adding to the Problem) by Ann K. Fisher.--“I was impressed with her chapter on taming feral cats. It would certainly take a dedicated soul to put that much work into taming …

Analysis Of Recovery Type A Posteriori Error Estimators For Mildly Structured Grids, Jinchao Xu, Zhimin Zhang

Mathematics Research Reports

Some recovery type error estimators for linear finite element method are analyzed under O(h^{1+alpha) (alpha greater than 0) regular grids. Superconvergence is established for recovered gradients by three different methods when solving general non-self-adjoint second-order elliptic equations. As a consequence, a posteriori error estimators based on those recovery methods are asymptotically exact.}