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Articles 601 - 630 of 2919

Full-Text Articles in Physical Sciences and Mathematics

Economic Tools For Managing Impacts Of Urban Canada Geese, Nicole H. Mccoy Aug 2000

Economic Tools For Managing Impacts Of Urban Canada Geese, Nicole H. Mccoy

Human Conflicts with Wildlife: 2002 Symposium

Management of urban Canada geese impacts can be assisted by the use of economic analyses of both the problem and the proposed solution. Management of a species that is both geographically mobile and stationary, protected by the Migratory Bird Act of 1918, and loved by much of the public while posing a significant risk of damage to both private and public property is a difficult task. The issue is further complicated by the scope and scale of urban goose impacts. While the presence of urban Canada geese results in both positive and negative impacts, this paper will focus primarily on …


Economic Analysis Of A Large Scale Oral Vaccination Program To Control Raccoon Rabies, Philip Kemere, Michael K. Liddel, Phylo Evangelou, Dennis Slate, Steven Osmek Aug 2000

Economic Analysis Of A Large Scale Oral Vaccination Program To Control Raccoon Rabies, Philip Kemere, Michael K. Liddel, Phylo Evangelou, Dennis Slate, Steven Osmek

Human Conflicts with Wildlife: 2002 Symposium

Since the late 1980s, results of oral vaccination trials in several states have provided growing evidence that this vaccination method may be effective for controlling the spread of rabies in raccoons (Procyon lotor). This study examines the economic feasibility of using oral vaccination on a larger scale than previous trials. We analyze the benefits and costs associated with a hypothetical barrier that would stretch from Lake Erie to the Gulf of Mexico, combining natural geographic features provided by the Appalachian Mountains with oral vaccination zones. The goal of this barrier would be to prevent the raccoon rabies variant …


Evaluation Of Wildlife Damage To Forests In Germany, Markus J. Schaller Aug 2000

Evaluation Of Wildlife Damage To Forests In Germany, Markus J. Schaller

Human Conflicts with Wildlife: 2002 Symposium

Legal regulations concerning wildlife damage in Germany are totally different from regulations in the United States. In certain cases German game laws provide the right to compensation for wildlife damage to forests for forest owners. But not everyone has to be compensated. Liability exists only for damage caused by hooved game, rabbits, and pheasants, and only to important local tree species (Hauptholzarten). If, for example, red deer damage an afforestation of Norway spruce (Picea abies) by browsing, normally the shooting tenant has to compensate for the damage. The most important types of damage to forests in Germany are …


Brown Treesnake Control: Economy Of Scales, Daniel S. Vice, Mikel E. Pitzler Aug 2000

Brown Treesnake Control: Economy Of Scales, Daniel S. Vice, Mikel E. Pitzler

Human Conflicts with Wildlife: 2002 Symposium

The accidental introduction of the brown treesnake (Boiga irregularis) to Guam led to the demise of most of the island’s native avifauna and herpetofauna. The snake is also responsible for significant economic losses through frequent power outages and consumption of poultry. Control of the snake, aimed at preventing its inadvertent dispersal from the island and protecting native wildlife and economic resources, is accomplished using specially designed snake traps, hand capture, snake detector dogs, and snake barriers. Although control tools capture large numbers of snakes, control efforts are labor intensive, costly, and ineffective in reducing snake populations across the …


Has An Integrated Pest Management Approach Reduced Blackbird Damage To Sunflower?, George M. Linz, Brian D. Peer, H. Jeffrey Homan, Ryan L. Wimberly, David L. Bergman, William J. Bleier Aug 2000

Has An Integrated Pest Management Approach Reduced Blackbird Damage To Sunflower?, George M. Linz, Brian D. Peer, H. Jeffrey Homan, Ryan L. Wimberly, David L. Bergman, William J. Bleier

Human Conflicts with Wildlife: 2002 Symposium

Since the mid-1970s many new and modified damage abatement methods have been implemented to reduce blackbird damage to ripening sunflower in the northern Great Plains. Concurrently, estimates were made of breeding blackbird densities and sunflower damage to track changes in population size and chart progress toward reducing damage. Breeding density estimates were made at both the regional and county levels, whereas sunflower damage estimates were made at the county level only. Periodic regional estimates of breeding densities, between 1967 and 1998, showed that numbers of red-winged blackbirds (Agelaius phoeniceus) and yellow-headed blackbirds (Xanthocephalus xanthocephalus) did not …


Cormorant Depredation Losses And Their Prevention At Catfish Farms: Economic Considerations, James F. Glahn, Scott J. Werner, Terry Hanson, Carole R. Engle Aug 2000

Cormorant Depredation Losses And Their Prevention At Catfish Farms: Economic Considerations, James F. Glahn, Scott J. Werner, Terry Hanson, Carole R. Engle

Human Conflicts with Wildlife: 2002 Symposium

Although several piscivorous birds are involved in depredation conflicts with southern aquaculture, the double-crested cormorant causes some of the most widespread and significant problems to catfish, the dominant industry. Unlike other agriculture commodities, catfish losses due to predation cannot be directly measured, so we review several approaches taken to estimate these losses. Although these approaches are valid for predicting the costs of simply replacing these fish at the time of predation, they have been criticized because they failed to consider the functional relationships between predation and output parameters at harvest. Recent controlled experiments are reviewed that confirm previous estimates of …


The Costs Of Bird Strikes And Bird Strike Prevention, John R. Allan Aug 2000

The Costs Of Bird Strikes And Bird Strike Prevention, John R. Allan

Human Conflicts with Wildlife: 2002 Symposium

Collisions between birds (and other wildlife) and aircraft are known to cause substantial losses to the aviation industry in terms of damage and delays every year. Techniques exist to control bird numbers on airfields and hence to reduce the number of wildlife strikes, but they are applied at widely different levels from airport to airport. Some of this variation may be due to differing levels of strike-risk at the different sites, but much of it is due to the unwillingness or inability of the airports concerned to invest in bird strike prevention. Part of the reason for this reluctance to …


Pieces Of Silver: Examples Of The Economic Impact And Management Of The Silver Gull (Larus Novaehollandiae) In Melbourne, Australia, Ian D. Temby Aug 2000

Pieces Of Silver: Examples Of The Economic Impact And Management Of The Silver Gull (Larus Novaehollandiae) In Melbourne, Australia, Ian D. Temby

Human Conflicts with Wildlife: 2002 Symposium

Like a number of gull species, the silver gull Larus novaehollandiae has expanded its population in response to human food subsidy. The major anthropogenic food source is food waste at rubbish tips. Other sources of human food waste are also exploited. Many problems result from the activities of these birds, including human health and safety, economic impacts, and effects on the conservation of other species. My study examines aspects of the economic impacts of the silver gull on the human community of the Greater Melbourne Area comprising approximately 4065 km2 (1569 square miles). My data collection method involves identifying sites …


Wildlife Impacts On Forest Resources, Dale L. Nolte, Mike Dykzeul Aug 2000

Wildlife Impacts On Forest Resources, Dale L. Nolte, Mike Dykzeul

Human Conflicts with Wildlife: 2002 Symposium

The negative impacts of wildlife on forest resources can be extensive. This paper provides some insight into the economic and environmental consequences of wildlife damage to forest resources and a brief overview of the damage inflicted by select wildlife species. Probably the most thorough measure of wildlife damage to forests in the Pacific Northwest was initiated in 1963 and 1964 by the Committee on Animal Damage Survey of the Western Forestry and Conservation Association. This study estimated that 30% of the tree seedlings planted would be damaged if no preventive practices were implemented; stocking rates on unprotected sites were 75% …


The Economic Impact Of Invasive Species To Wildlife Services’ Cooperators, David L. Bergman, Monte D. Chandler, Adrienne Locklear Aug 2000

The Economic Impact Of Invasive Species To Wildlife Services’ Cooperators, David L. Bergman, Monte D. Chandler, Adrienne Locklear

Human Conflicts with Wildlife: 2002 Symposium

On February 3, 1999, the president of the United States signed an Executive Order 13112 on invasive species. Each federal agency was directed to detect and respond rapidly to control populations of invasive species, monitor invasive species populations, provide for restoration of native species and habitat conditions, conduct research on invasive species and develop technologies to prevent their introduction, and promote public education on invasive species and the means to address them. The United States Department of Agriculture’s Wildlife Services Program fulfills a federal responsibility for helping solve problems which occur when human activity and wildlife, including invasive species, are …


Time-Resolved Photoluminescence Lifetime Measurements Of The Gamma(5) And Gamma(6) Free Excitons In Zno, D. C. Reynolds, David C. Look, B. Jogai, J. E. Hoelscher, R. E. Sherriff, M. T. Harris, M. J. Callahan Aug 2000

Time-Resolved Photoluminescence Lifetime Measurements Of The Gamma(5) And Gamma(6) Free Excitons In Zno, D. C. Reynolds, David C. Look, B. Jogai, J. E. Hoelscher, R. E. Sherriff, M. T. Harris, M. J. Callahan

Physics Faculty Publications

Time-resolved photoluminescence spectroscopy at 2 K was used to measure the radiative recombination lifetime of the allowed (Γ5) and forbidden (Γ6) free excitons in ZnO. The measurements were made on a sample containing internal strain, which altered the sample symmetry, and resulted in relaxed selection rules, allowing the Γ6 exciton to be observed. A radiative recombination lifetime of 259 ps was measured for the Γ5 exciton and 245 ps for the Γ6 exciton. The decay of the free excitons was of single-exponential form, and the decay times were obtained using a least-squares fit …


Computer-Aided Synthesis Of Higher Pairs Via Configuration Space Manupulation, Min-Ho Kyung, Elisha Sacks Aug 2000

Computer-Aided Synthesis Of Higher Pairs Via Configuration Space Manupulation, Min-Ho Kyung, Elisha Sacks

Department of Computer Science Technical Reports

No abstract provided.


Molecular-Dynamics Study Of Phase Transitions In Alkali Thiocyanates, M. M. Ossowski, John R. Hardy, R. W. Smith Aug 2000

Molecular-Dynamics Study Of Phase Transitions In Alkali Thiocyanates, M. M. Ossowski, John R. Hardy, R. W. Smith

John R. Hardy Papers

An account is presented of our studies of the order-disorder phase transitions in KSCN, RbSCN, and CsSCN. These are based on parameter-free interionic potentials based on the Gordon-Kim modified electron gas formalism extended to molecular ions. We performed static structural relaxations and supercell molecular dynamics and predicted with reasonable accuracy the temperatures for the onset of the transitions. In particular, we address the question of how the SCN- ions disorder to yield subsequent structural transformations. We found high-temperature phases of average Fm3m symmetry for both KSCN and RbSCN. We argue that in reality the full appearance of …


Theoretical Basis For The Ce-Qual-W2 River Basin Model, Scott A. Wells, Thomas M. Cole Aug 2000

Theoretical Basis For The Ce-Qual-W2 River Basin Model, Scott A. Wells, Thomas M. Cole

Civil and Environmental Engineering Faculty Publications and Presentations

The primary objective of this research is to integrate a riverine model into the existing W2 code that would provide the capability for modeling entire watersheds. This task was accomplished by the following steps:

• Formal derivation of governing equations and solution algorithm with general channel slope

• Detailed analysis of algorithm for linking branches and smooth implementation of boundary conditions between branches

• Algorithm development and changes to basic model code (including branch definitions with slope, slope correction to solution algorithm, transfer of momentum between internal branches)

These tasks were performed with the following constraints and initiatives:

• Utilize …


Properties Of Semi‐Insulating Gaas:Fe Grown By Hydride Vapor Phase Epitaxy, E. Rodríguez Messmer, D. Söderström, P. Hult, S. Marcinkevicius, S. Lourdudoss, David C. Look Aug 2000

Properties Of Semi‐Insulating Gaas:Fe Grown By Hydride Vapor Phase Epitaxy, E. Rodríguez Messmer, D. Söderström, P. Hult, S. Marcinkevicius, S. Lourdudoss, David C. Look

Physics Faculty Publications

In this paper we analyze GaAs grown by hydride vapor phase epitaxy (HVPE) and doped with four different iron concentrations between and . From temperature dependent current‐voltage measurements we observed the highest resistivity in the lowest doped sample. We also quantified the activation energy. These results together with those of time resolved photoluminescence measurements indicate that in the sample with the lowest Fe concentration, EL2 may be dominant. From the analysis of the time resolved photoluminescence measurements, the intrinsic EL2 concentration and the electron and hole capture cross sections of Fe in GaAs were estimated. © 2000 The Electrochemical Society. …


Electrical Properties Of Boron-Doped P-Sigec Grown On N(-)-Si Substrate, M. Ahoujja, Y. K. Yeo, R. L. Hengehold, G. S. Pomrenke, David C. Look, J. Huffman Aug 2000

Electrical Properties Of Boron-Doped P-Sigec Grown On N(-)-Si Substrate, M. Ahoujja, Y. K. Yeo, R. L. Hengehold, G. S. Pomrenke, David C. Look, J. Huffman

Physics Faculty Publications

Electrical properties of fully strained boron-doped Si0.90−yGe0.10Cy/n–Si grown by low pressure chemical vapor deposition have been investigated as a function of carbon content (0.2%–1.5%), using the variable temperature (25–650 K) Hall-effect technique. The results of Hall-effect measurements show that the Si substrate and the SiGeC/Si interfacial layer affect significantly the electrical properties of the SiGeC epitaxial layer. Thus, a three-layer conducting model has been used to extract the carrier concentration and mobility of the SiGeC layer alone. At room temperature, the hole carrier concentration decreases from 6.8×1017 to 2.4×10 …


Limits On Anomalous Ww Γ And Wwz Couplings From Ww/WzEνjj Production, B. Abbott, Gregory Snow, D0 Collaboration Aug 2000

Limits On Anomalous Ww Γ And Wwz Couplings From Ww/Wz→Eνjj Production, B. Abbott, Gregory Snow, D0 Collaboration

Gregory Snow Publications

Limits on anomalous WW γ and WWZ couplings are presented from a study of WW/WZeνjj events produced in pp̅ collisions at √s = 1.8 TeV. Results from the analysis of data collected using the DØ detector during the 1993–1995 Tevatron collider run at Fermilab are combined with those of an earlier study from the 1992–1993 run. A fit to the transverse momentum spectrum of the W boson yields direct limits on anomalous WW γ and WWZ couplings. With the assumption that the WW γ and WWZ couplings are equal, we obtain -0.34 < λ < 0.36 (with Δk=0) and -0.43< Δk<0.59 (with λ =0) at the 95% confidence level for a form-factor scale Λ = 2.0 TeV.


Shape-Vq-Based Lossless Hybrid Adpcm/Dct Coder, J. Wang, F. Naghdy Aug 2000

Shape-Vq-Based Lossless Hybrid Adpcm/Dct Coder, J. Wang, F. Naghdy

Faculty of Informatics - Papers (Archive)

The discrete cosine transform (DCT) has been shown as an optimum encoder for sharp edges in an image (Andrew and Ogunbona, 1997). A conventional lossless coder employing differential pulse code modulation (DPCM) suffers from significant deficiencies in regions of discontinuity, because the simple model cannot capture the edge information. This problem can be partially solved by partitioning the image into blocks that are supposedly statistically stationary. A hybrid lossless adaptive DPCM (ADPCM)/DCT coder is presented, in which the edge blocks are encoded with DCT, and ADPCM is used for the non-edge blocks. The proposed scheme divides each input image into …


Molecular-Dynamics Study Of Phase Transitions In Alkali Thiocyanates, M. M. Ossowski, John R. Hardy, Robert W. Smith Aug 2000

Molecular-Dynamics Study Of Phase Transitions In Alkali Thiocyanates, M. M. Ossowski, John R. Hardy, Robert W. Smith

Physics Faculty Publications

An account is presented of our studies of the order-disorder phase transitions in KSCN, RbSCN, and CsSCN. These are based on parameter-free interionic potentials based on the Gordon-Kim modified electron gas formalism extended to molecular ions. We performed static structural relaxations and supercell molecular dynamics and predicted with reasonable accuracy the temperatures for the onset of the transitions. In particular, we address the question of how the SCN2 ions disorder to yield subsequent structural transformations. We found high-temperature phases of average Fm3¯m symmetry for both KSCN and RbSCN. We argue that in reality the full appearance of these phases is …


Computational Geometry Column 39, Joseph O'Rourke Aug 2000

Computational Geometry Column 39, Joseph O'Rourke

Computer Science: Faculty Publications

The resolution of a decades-old open problem is described: polygonal chains cannot lock in the plane.


Cyclodextrin Inclusion Complexes Of Betamethasone-Related Steroids Studied Using Hplc, Keith Gerald Flood Aug 2000

Cyclodextrin Inclusion Complexes Of Betamethasone-Related Steroids Studied Using Hplc, Keith Gerald Flood

Seton Hall University Dissertations and Theses (ETDs)

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Reaction Of Tricarbonyl(Dienal)Iron Complexes With B-Allyldiisopinocampheylborane, Vadapalli Prahlad, Abdel-Aziz S. El-Ahl, William Donaldson Aug 2000

Reaction Of Tricarbonyl(Dienal)Iron Complexes With B-Allyldiisopinocampheylborane, Vadapalli Prahlad, Abdel-Aziz S. El-Ahl, William Donaldson

Chemistry Faculty Research and Publications

Addition of allyldiisopinocampheylborane to racemic (dienal)iron complexes, followed by oxidation, affords diastereomeric (1,4,6-trien-3-ol)iron complexes with moderate to low enantioselectivity. The high enantioselectivity typically observed for this allylborane reagent is attenuated by steric interaction between the Fe(CO)3 group and the chiral isopinocampheyl groups. Further diminution of the enantioselectivity is observed for dienal complexes in which one rotomer predominates.


Economics Of Using On-Farm Reservoirs To Distribute Diverted Surface Water To Depleted Ground Water Areas Of The Southern Mississippi Valley Region, Eric J. Wailes, Kenneth B. Young, James Smartt, Gail L. Cramer Aug 2000

Economics Of Using On-Farm Reservoirs To Distribute Diverted Surface Water To Depleted Ground Water Areas Of The Southern Mississippi Valley Region, Eric J. Wailes, Kenneth B. Young, James Smartt, Gail L. Cramer

Technical Reports

Rapid ground water depletion has become a significant problem for parts of the Southern Mississippi River Valley. In 1997, the Arkansas Soil and Water Conservation Commission (ASWCC) declared six counties in the Grand Prairie of Arkansas critical ground water areas. A proposed solution to the ground water depletion problem in this region is to divert surplus flows from the White River by a canal system to the farmer stakeholders. To make the system work, on-farm reservoirs will be needed to store and manage the diverted surface water for crop irrigation use during the growing season.


High Efficiency Separation Of Microbial Aggregates Using Capillary Electrophoresis, J. M. Schneiderheinze, Daniel W. Armstrong, G. Schulte, David J. Westenberg Aug 2000

High Efficiency Separation Of Microbial Aggregates Using Capillary Electrophoresis, J. M. Schneiderheinze, Daniel W. Armstrong, G. Schulte, David J. Westenberg

Chemistry Faculty Research & Creative Works

Recent advances in the technique of capillary electrophoresis have demonstrated fast, highly efficient separation of mixtures of intact microbes. This paper describes the application of this technique for the separation of microbial aggregates of Micrococcus luteus, Saccharomyces cerevisiae, or Alcaligenes faecalis. The aggregates of these microbes were resolved into several highly efficient peaks with analysis times under 10 min and efficiencies approaching 1 000 000 plates m-1 in some cases. A reproducible relationship was found between the electrophoretic mobility and the aggregation number or size of the cluster under a given set of experimental conditions. Often, cellular aggregation was reversible …


Rodent Mining Engineers, Ray Sterner Aug 2000

Rodent Mining Engineers, Ray Sterner

United States Department of Agriculture Wildlife Services: Staff Publications

Colorado’s seldom-seen pocket gophers are getting some attention from the National Wildlife Research Center. Researchers are attempting to improve management of gophers in agricultural areas. Although the gophers’ tunnel building may damage harvest equipment, their activities enrich soils over time.


The John Muir Newsletter, Fall 2000, The John Muir Center For Regional Studies Aug 2000

The John Muir Newsletter, Fall 2000, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

I J ' Ov Volume 10, Number 4 NEWSLETTER I Fall 2000 A Sense of the Natural by Richard F. Fleck w rom the time of my first published essay about a Maine sea coast tidal pool in June, 1954 (when I was not quite seventeen), until now, some forty-six fpars later, my major source of inspiration has been the Batural world, be it the Irish Mountains of Mourne rolling flown to the sea or the rocky coast of Maine, or the windy Himmits of Longs Peak, Colorado or Mount Fuji, Japan, ■have always delighted in the smell of turf …


Performance Analysis Of Mobile Agents For Filtering Data Streams On Wireless Networks, David Kotz, Guofei Jiang, Robert Gray, George Cybenko, Ronald A. Peterson Aug 2000

Performance Analysis Of Mobile Agents For Filtering Data Streams On Wireless Networks, David Kotz, Guofei Jiang, Robert Gray, George Cybenko, Ronald A. Peterson

Dartmouth Scholarship

Wireless networks are an ideal environment for mobile agents, because their mobility allows them to move across an unreliable link to reside on a wired host, next to or closer to the resources they need to use. Furthermore, client-specific data transformations can be moved across the wireless link, and run on a wired gateway server, with the goal of reducing bandwidth demands. In this paper we examine the tradeoffs faced when deciding whether to use mobile agents to support a data-filtering application, in which numerous wireless clients filter information from a large data stream arriving across the wired network. We …


The Relationship Of Small Mammal Species To Habitat Variables In West-Central Georgia And East-Central Alabama, Patricia Maureen Kosky Aug 2000

The Relationship Of Small Mammal Species To Habitat Variables In West-Central Georgia And East-Central Alabama, Patricia Maureen Kosky

Theses and Dissertations

The objective of this investigation was to assess the impact of environmental variables upon small mammal species distribution in 60 plots on Fort Benning, Muscogee and Chattahoochee Counties, Georgia and Russell County, Alabama. The small mammal fieldwork was carried out in December of 1994 through January of 1995. The vegetation was inventoried in June through October of 1995. During this period, 235 small mammals were trapped in a total of 5950 trap nights. A total of 10 small mammal species and 234 plant species were identified. The small mammal species abundance's were determined by using snap trapping along the plot …


Rosat Hri And Asca Observations Of The Spiral Galaxy Ngc 6946 And Its Northeast Complex Of Luminous Supernova Remnants, Eric M. Schlegel, William P. Blair, Robert A. Fesen Aug 2000

Rosat Hri And Asca Observations Of The Spiral Galaxy Ngc 6946 And Its Northeast Complex Of Luminous Supernova Remnants, Eric M. Schlegel, William P. Blair, Robert A. Fesen

Dartmouth Scholarship

Analysis of 80 ks ASCA and 60 ks ROSAT HRI observations of the face-on spiral galaxy NGC 6946 are presented. The ASCA image is the first observation of this galaxy above ~2 keV. Diffuse emission may be present in the inner ~4' extending to energies above ~2–3 keV. In the HRI data, 14 pointlike sources are detected, the brightest two being a source very close to the nucleus and a source to the northeast that corresponds to a luminous complex of interacting supernova remnants (SNRs). We detect a point source that lies ~30'' west of the SNR complex but with …


Photophysical Study Of Linked 1,4,7-Triazacyclonane Cr (Iii) Complexes, Weizhen Tu Aug 2000

Photophysical Study Of Linked 1,4,7-Triazacyclonane Cr (Iii) Complexes, Weizhen Tu

Masters Theses

A series of mono and bimetallic Cr(III) complexes based on the 1,4,7- triazacyclonoane(TACN) were prepared. Complexes of the Cr(TACN)X3 , and Cr2(DTNE)X6 demonstrated marked difference of photophysical properties on the nature of X. In cases where X is more easily oxidized, enhanced extinction coefficient in the 4A22T, absorption and larger quantum yield of emission at 77K were observed in the dimer complexes. Shorter lifetime and enhanced decay rate were also found in the dimer complexes suggests that there might exists weak coupling behavior between the two Cr(III) metal cents in the …