Physical Sciences and Mathematics Commons^™

Minimizing The Number Of Optical Amplifiers Needed To Support A Multi-Wavelength Optical Lan/Man, Byrav Ramamurthy, Jason Iness, Biswanath Mukherjee

CSE Conference and Workshop Papers

Optical networks based on passive star couplers and employing wavelength-division multiplexing (WDhf) have been proposed for deployment in local and metropolitan areas. Amplifiers are required in such networks to compensate for the power losses due to splitting and attenuation. However, an optical amplifier has constraints on the maximum gain and the maximum output power it can supply; thus optical amplifier placement becomes a challenging problem. The general problem of minimizing the total amplifier count, subject to the device constraints, is a mixed-integer non-linear problem. Previous studies have attacked the amplifier placement problem by adding the “artificial” constraint that all wavelengths, …

1997 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Knots And Links In Three-Dimensional Flows, Robert W. Ghrist, Philip J. Holmes, Michael C. Sullivan

Books, Monographs and Lecture Notes

No abstract provided.

Glaciochemical Studies At Siple Dome, West Antarctica, During The 1996–1997 Season, Karl J. Kreutz, Paul Andrew Mayewski, Mark S. Twickler, Sallie I. Whitlow, L. David Meeker

Earth Science Faculty Scholarship

Deep ice cores collected from the interior of the west antarctic ice sheet and the interice stream ridges along the Siple Coast potentially contain long time-series records of Southern Hemisphere environmental change. One such location is Siple Dome, an approximately l20-kilometer (km) x 250-km ice dome located between ice streams C and D (figure 1). Because of promising results from reconnaissance glaciochemical (Mayewski, Twickler, and Whitlow 1995) and geophysical (Raymond et al. 1995) research, current U.S. deep ice-coring efforts are focused in the area. Drilling at Siple Dome is advantageous for several reasons, including the site's relatively simple geometry and …

Floristic Investigation Of Crooked Creek Community Of Juan Solomon Park, Indianapolis Indiana, Raelene M. Crandall, Rebecca W. Dolan

Scholarship and Professional Work - LAS

The protection of plant resources in urban areas is a growing conservation concern. Inventory activities that document species presence and stewardship plans that protect and enhance these areas are needed. The results of a botanical inventory of the Crooked Creek Community Juan Solomon Park in Indianapolis, Indiana, are reported in this paper. The 46-acre park contains three distinct habitats, supporting a wide variety of plants. One hundred seventy-nine vascular plant species from 64 families were identified, including 53 (29.6%) non-native species that are naturalizing within the park. Despite its high percentage of alien species and urban setting, the park is …

Genetic Algorithms For The Extended Gcd Problem, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

We present several genetic algorithms for solving the extended greatest common divisor problem. After defining the problem and discussing previous work, we will state our results.

Distribution And Abundance Of The Amazon River Dolphin (Inia Geoffrensis) And The Tucuxi (Sotalia Fluviatilis) In The Upper Amazon River, Omar Vidal, Jay Barlow, Luis A. Hurtado, Instituto Tecnológico Y De Estudios Superiores De Monterrey (Itesm), Patricia Cendón, Zully Ojeda

United States Department of Commerce: Staff Publications

A boat survey was conducted from 5 to 26 June 1993 to estimate the abundance of the Amazon river dolphin (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis) along ca. 120 km of the Amazon River bordering Colombia, Peru, and Brazil. Two survey methods were used: line transects during 5 d and strip transects during 15 d. The line transects were used to estimate the abundance of both species in the main channels of the Amazon at distances greater than 200 m from river banks and islands, and strip transects were used to estimate abundance in the …

Recurrent Geomagnetic Storms And Relativistic Electron Enhancements In The Outer Magnetosphere: Istp Coordinated Measurements, D. N. Baker, X. Li, N. Turner, J. H. Allen, L. F. Bargatze, J. B. Blake, R. B. Sheldon, Harlan E. Spence, R. D. Belian, G. D. Reeves, S. G. Kanekal, B. Klecker

Physics & Astronomy

New, coordinated measurements from the International Solar-Terrestrial Physics (ISTP) constellation of spacecraft are presented to show the causes and effects of recurrent geomagnetic activity during recent solar minimum conditions. It is found using WIND and POLAR data that even for modest geomagnetic storms, relativistic electron fluxes are strongly and rapidly enhanced within the outer radiation zone of the Earth's magnetosphere. Solar wind data are utilized to identify the drivers of magnetospheric acceleration processes. Yohkoh solar soft X-ray data are also used to identify the solar coronal holes that produce the high-speed solar wind streams which, in turn, cause the recurrent …

Quantum Coherence In Small Antiferromagnets, S. E. Barnes, R. Ballou, B. Barbara, J. Strelen

Physics Articles and Papers

An antiferromagnetic particle with an excess spin j⃗ has 2 degrees of freedom. The one associated with j⃗ is ferromagnetic, while the antiferromagnetic behavior involves Néel vector n⃗. It is shown that the spin-parity effect described by Loss et al. has to do with the ferromagnetic degree of freedom and does not imply the localization of n⃗ for small enough particles for half-integer spin. It is also shown that the tunnel splitting associated with n⃗ is insensitive to applied fields.

No Tillage Use For Crop Production In Kentucky Counties In 1996, Gerald R. Haszler, Grant W. Thomas

Soil Science News and Views

Two years ago, we reported the status of notillage adoption in Kentucky counties in the year 1994. Now, CTIC has published the results for 1996. As before, Kentucky leads the nation in percent of crops produced under no tillage, but the percentage has increased significantly. In 1994, 44% of crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51 %. The results for both 1994 and 1996 are shown in Table 1. It is evident that Kentucky has both maintained first place and has also increased its lead over the other states. The percentage …

Pelletized Lime - How Quickly Does It React, Lloyd W. Murdock

Soil Science News and Views

Pelletized lime is made by granulating finely ground agricultural (ag) lime. It may be dolomitic or calcitic depending on the nature of the original limestone. The fine lime particles are bonded together with lignosulfonates during the pelletizing process. In general, the pelletized lime contains about 9% lignosulfonates. Pelletized limestone is a product that has been on the market for many years. The price of the material on a per ton basis is considerably higher than bulk ag lime, so its use has mainly been confined to specialty markets, with little use in production agriculture. However, the product is becoming more …

How Do Bacteria Move Through Soil?, Mark S. Coyne, J. M. Howell, R. E. Phillips

Soil Science News and Views

The contamination of water supplies by fecal bacteria is an important water quality issue in Kentucky. Contamination may come from point sources, such as straight pipes depositing raw sewage into streams, or nonpoint sources, such as manure runoff from cropland. A direct cost of contaminating water supplies is the expense that homesteads or water companies incur to chlorinate, filter, and otherwise treat water to make it potable. Indirect costs are the time lost to illness from drinking inadequately treated water, slower weight gain in livestock drinking contaminated water, and the degradation of aquatic habitats.

Detection Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Agricultural Watershed In Western Kentucky, John Potts, Larry Reber

Soil Science News and Views

The quality of water in Kentucky's agricultural watersheds has received considerable attention in recent years. The main concerns in com production areas usually center on content of nitrogen (N) from commercial fertilizer and triazines from herbicide applications in water. Although N can be found naturally in Kentucky soils, it can't supply all the N that com needs to produce optimum yields. Therefore, fertilizer N is added to ensure ample nutrition. Triazine herbicides, on the other hand, do not occur naturally in the soil but are applied to the soil to effectively control weeds. Most commonly, these herbicides are applied at …

Vegetative Filter Strip Removal Of Metals In Runoff From Poultry Litter-Amended Fescuegrass Plots, Dwayne R. Edwards, P. A. Moore Jr., Tommy C. Daniel, Puneet Srivastava, D. J. Nichols

Biosystems and Agricultural Engineering Faculty Publications

Runoff from land areas amended with poultry (Gallus gallus domesticus) manure can contain elevated concentrations of metals such as Cu, Fe, and Zn. Vegetative filter strips (VFS) can reduce runoff concentrations of animal manure components, but reported studies have typically focused on nutrients and solids rather than metals. This experiment assessed the impact of VFS length (0 to 12 m) on concentrations and mass losses of Cu, Fe, K, Na, Ni, and Zn in runoff from fescuegrass (Festuca arundinacea Schreb.) plots (1.5 m wide × 6 and 12 m long) treated with poultry litter. The runoff was produced from simulated …

Review Of The Nuclear Black Market, Global Organized Crime Project, David W. Hafemeister

Physics

No abstract provided.

Summing Up: Questions And Answers On The Comprehensive Test Ban Treaty, David W. Hafemeister

Physics

My experiences with the ratification of the Strategic Arms Reduction Treaty, the Threshold Test Ban Treaty, and the Conventional Armed Forces in Europe Treaty have led me to conclude that presenting technical issues early in the process greatly reduces their politicization during the ratification end game. This chapter summarizes the important issues that will be raised during the debate on ratification of the Comprehensive Test Ban Treaty. It uses a compact question and answer format to cover the following topics: I. Nuclear Proliferation, II. Nuclear Arms Control, III. Warhead Reliability and Yield for National Security, IV. Warhead Safety, V. Verification, …

A Child's Flashlight And Rc Circuit Concepts, Matthew J. Moelter, Rand S. Worland

Physics

No abstract provided.

Effects Of Seagrass Biology On Water Quality In Shallow Regions Of The Lower Chesapeake Bay : Final Report, Kenneth A. Moore

Reports

The changes in water quality within shallow water regions of the lower Chesapake Bay was compared seasonally from permanent stations located along transects across vegetated and unvegetated sites in shoal regions of the lower Chesapeake Bay. The effect of the seagrass bed on conditions inside compared to outside of the bed varied seasonally and could be related to bed biomass and develoment. During spring (April-June) the rapidly growing seagrass bed was a sink for nutrients, suspended inorganic particles and phytoplankton, while during the summer, as bed dieback progressed, resuspension and release of nutrients were observed. Reductions in suspended particle concentrations …

Analysis Of Glasses Present In Quartz And Apatite Phenocrysts From Ordovician K-Bentonites In The Mohawk Valley, Ny, Stefanie Dannenmann

Geology Theses and Dissertations

More than 20 bentonites occur in the Middle Ordovician black shales of the Utica Formation that outcrop along tributaries to the Mohawk River in New York State. Pristine melt inclusions within quartz and apatite phenocrysts are commonly found in at least 40% of the bentonites. Constraints on magmatic processes can be obtained by examining the major-, minor- and trace-element variations among different melt inclusions in quartz and apatite phenocrysts from individual bentonites. The melt inclusions in apatite range in composition from rhyodacitic to rhyolitic, while those in quartz are high-silica rhyolites. Most bentonites within the Middle Ordovician sequence in New …

Pre-Thrust Normal Faults And Post-Tectonic Micas In The Taconic Range Of West-Central Vermont, Nicholas W. Hayman

Geology Theses and Dissertations

New geologic maps show that the Champlain Thrust System traces continuously between Shoreham and Benson, Vermont. The Champlain Thrust System consists of at least three internally imbricated thrust slices in continental shelf facies quartzites and carbonates. From north to south there is a structurally controlled thinning of the Champlain Thrust System, and a climbing in stratigraphic level by the thrusts. Within the Champlain Thrust System are a set of across-strike structures which create offsets in the thrusts and the surrounding lithic map unit boundaries. These structures function as lateral ramps in the thrust system geometry and bound thrust duplexes. Often …

Late Cretaceous Dinosaurs In Eastern Usa—A Taphonomic And Biogeographic Model Of Occurrences., David R. Schwimmer

Faculty Bibliography

The eastern Coastal Plains of the USA contain a Late Cretaceous dinosaur assemblage of limited taxic diversity, but with wide distribution and reasonably good abundance. The ages of specimens range from Santonian through late Maastrichtian. All Late Cretaceous eastern dinosaur specimens occur in pericontinental or marine strata, and therefore all such fossils are likely to be allochthonous. New materials and insights bear on the taphonomy of these marine occurrences, suggesting that fluvially-transported, floating carcasses, many scavenged by sharks, make up most of the eastern marine dinosaur record. There is little evidence of faunal provinciality across the entire eastern outcrop: fossil …

On Power Bounded Operators., Eugen J. Ionascu

Faculty Bibliography

In this paper we generalize the following consequence of a wellknown result of Nagy: if T and T −1 are power bounded operators, then T is a polynomially bounded operator.

The Selachian Genus Sqaulicorax As Preeminent Scavengers In Upper Cretaceous Marine Sediments Of North America, David R. Schwimmer

Faculty Bibliography

No abstract provided.

Land Use Patterns In Relation To Lake Water Quality In The Messalonskee Lake Watershed, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College

Colby College Watershed Study: Other Area Studies

The main purpose of this study is to assess the current land use patterns and their influences on the water quality of Messalonskee Lake, including the biotic and abiotic parameters which are involved. More specifically, four main objectives were proposed. First, was to calculate the water budget and flushing rate for Messalonskee Lake. Second, was to determine the influence of current and historical land use patterns on lake water quality. Third, was to utilize gathered information to construct a phosphorus model, which will enable future water quality predictions to be made. Our fourth and final objective was to make recommendations …

H2s Adsorption On Chromium, Chromia, And Gold/Chromia Surfaces: Photoemission Studies, J A. Rodriguez, S Chaturvedi, U Diebold, M Kuhn, J Van Ek, P S. Robbert, H Geisler, C A. Ventrice Jr

Physics Faculty Publications

The reaction of H₂S with chromium, chromia, and Au/chromia films grown on a Pt(111) crystal has been investigated using synchrotron-based high-resolution photoemission spectroscopy. At 300 K, H₂S completely decomposes on polycrystalline chromium producing a chemisorbed layer of S that attenuates the Cr 3d valence features. No evidence was found for the formation of CrS_x species. The dissociation of H₂S on Cr₃O₄ and Cr₂O₃ films at room temperature produces a decrease of 0.3–0.8 eV in the work function of the surface and significant binding-energy shifts (0.2–0.6 eV) …

Intrinsic Chaos In A Dc Field Biased Quantum Heterostructure, A. Jason Mcnary, Ashok Puri

Physics Faculty Publications

A closed, quantum, double barrier, GaAs/AlGaAs heterostructure is made chaotic by adding a nonlinear potential term, α〈Q(t)〉, to the time-dependent Schrödinger equation, and the dynamical behavior of an electron cloud moving in the heterostructure biased by a dc electric field is examined numerically. Using phase-space diagrams, power spectrums, and Lyapunov exponents, both qualitative and quantitative measures of the chaos in the system were taken. In general, for all values of α, the nonlinearity parameter, the Lyapunov exponent, λ, increases as the applied dc field, β, increases. However, for values of α ⩽ 1.376, we notice …

Optical Studies Of Ge Islanding On Si(111), P. D. Persans, P. W. Deelman, K. L. Stokes, L. J. Schowalter, A. Byrne, T. Thundat

Physics Faculty Publications

We report an experimental study of the optical properties of island layers resulting from molecular beam epitaxial deposition of Ge on Si(111) substrates. The combination of electroreflectance spectroscopy of the E₁ transition and Raman scattering allows us to separately determine the strain and composition of the islands. For deposition at 500 °C a deposited layer of 1.36 nm of Ge assembles into 80 nm diameter islands 11 nm thick. The average Si impurity content in the islands is 2.5% while the average in-plane strain is 0.5%. Both strain and Si impurity content in islands decrease with increasing Ge deposition

An Error Handling Framework For The Orbwork Workflow Enactment Service Of Meteor, Davasish Worah, Amit P. Sheth, Krzysztof J. Kochut, John A. Miller

Kno.e.sis Publications

Workflow Management Systems (WFMSs) can be used to re-engineer, streamline, automate, and track organizational processes involving humans and automated information systems. However, the state-of-the-art in workflow technology suffers from a number of limitations that prevent it from being widely used in large-scale mission critical applications. Error handling is one such issue. What makes the task of error handling challenging is the need to deal with errors that appear in various components of a complex distributed application execution environment, including various WFMS components, workflow application tasks of different types, and the heterogeneous computing infrastructure.

In this paper, we discuss a top-down …

1997 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Chesapeake Bay Hall Dedication, Virginia Institute Of Marine Science, School Of Marine Science, College Of William And Mary

Miscellaneous

Dedication: April 25, 1997. Invitation to dedication ceremony and program booklet. List of research laboratories provided.