Physical Sciences and Mathematics Commons^™

Failure To Observe Electron Circular Dichroism In Camphor, K. W. Trantham, M. E. Johnston, Timothy J. Gay

Timothy J. Gay Publications

Analogous to optical circular dichroism, it is possible to have electron circular dichroism, the preferential transmission of longitudinally polarized electrons through a chiral medium. Using stereoisomers of camphor vapor as a scattering target, we looked for this effect at incident electron energies of 1, 3, 5, 7, or 10 eV. Within our detection limit (~0.02%) we have not observed a spin-dependent asymmetric transmission.

Résumé : En analogie avec le dichroïsme circulaire optique, il est possible d'avoir un dichroïsme circulaire électronique, la propagation préférentielle d'électrons polarisés longitudinalement à travers un milieu chiral. Utilisant de la vapeur de stéréoisomères de carnphre comme …

Effects Of The June 1995 Freshet On The Main Virginia Tributaries To The Chesapeake Bay, Herbert M. Austin, Christopher F. Bonzek

VIMS Articles

Environmental conditions in the Virginian waters of the Chesapeake Bay area during the summerof 1995 have been characterized as a severe drought. This drought was punctuated on 27 June with a headwater (James and Rappahannock River) rain storm that produced a "freshet". Although it did not rain in the Tidewater area of Virginia, surface salinities were depressed by the run-off, and main-stem bottom ox}'gen levels dropped to z.ero in the James and Rappahannock rivers. The effects of the reduced oxygen were apparent on the James River oyster stock, particularly the reduction in spatfall, and to a lesser degree on the …

No-Till Sowing : Helping To Keep Cropland Soils In Place, Kevin Bligh, Paul Findlater

Journal of the Department of Agriculture, Western Australia, Series 4

Repeated erosion of tilled land can ;ower crop and pasture yields because of reduced available moisture and nutrient storage. Kevin Bligh and Paul Findlater look at the causes of water and wind erosion and the role of no-till sowing in minimising erosion.

An Ice-Shelf Model Test Based On The Ross Ice Shelf, D. R. Macayeal, V. Rommelaere, P. Huybrechts, Christina L. Hulbe, J. Determann, C. Ritz

Geology Faculty Publications and Presentations

A standard numerical experiment featuring the Ross Ice Shelf, Antarctica, is presented as a test package for the development and intercomparison of ice-shelf models. The emphasis of this package is solution of stress-equilibrium equations for an ice-shelf velocity consistent with present observations. As a demonstration, we compare five independently developed ice-shelf models based on finite-difference and finite-element methods. Our results suggest that there is little difference between finite-element and finite-difference methods in capturing the basic, large-scale flow features of the ice shelf. We additionally show that the fit between model and observed velocity depends strongly on the ice-shelf temperature field …

Early Life History Of Yellow Perch In Eastern South Dakota Lakes, Shannon Fisher

Electronic Theses and Dissertations

Yellow perch Perea flavescens are a popular South Dakota sportfish; however, inconsistent recruitment creates highly variable and unpredictable perch fishery quality. Before fishery managers can begin to develop and assess strategies to stabilize yellow perch recruitment, a better understanding of their early life history is required. I selected two natural lakes with differing yellow perch population types and monitored brood stock, spawning habits, and larval and juvenile life history patterns during 1995 and 1996. Pelican Lake was selected as a representative yellow perch population exhibiting inconsistent recruitment and Pickerel Lake as a population with relatively consistent recruitment. Yellow perch tended …

Geomorphological Aspects Of Gypsum Karst Areas With Special Emphasis On Exposed Karst, Ugo Sauro

International Journal of Speleology

Medium- to large-size forms in gypsum karst are described, including dolines, blind valleys, ploje-like depressions, collapses and positive and/or residual forms such as outliers, cone-like hills, dome-like hills, mesa-like tabular blocks and plateaux and breccia pipe hills. The similarities and/or difference between gypsum and carbonate forms are discussed.

Breakdown Development In Cover Beds, And Landscape Features Induced By Intrastratal Gypsum Karst, Alexander Klimchouk, Vjacheslav Andrejchuk

International Journal of Speleology

Intrastratal karst is by far the predominant gypsum karst type. Its development may begin in deep-seated settings within rocks already buried by younger strata, and it proceeds increasingly rapidly as uplift brings gypsum sequences into progressively shallower positions. Such development commonly occurs under confined (artesian) hydrogeological conditions, that subsequently change to open conditions (phreatic-water table-vadose). The general evolutionary line of intrastratal karst is typified by progressive emergence of a sequence into a shallower position, activation of groundwater circulation and development of cave systems within karst units, commencement of gravitational breakdown and its upward propagation through overlying beds, and development of …

Gypsum Karst In The United States, Kenneth S. Johnson

International Journal of Speleology

Gypsum is one of the most soluble of common rocks; it is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are found in limestones and dolomites. The four basic requirements for gypsum karst to develop are: (1) a deposit of gypsum; (2) water, unsaturated with CaSO₄ (3) an outlet for escape of dissolving water; and (4) energy to cause water to flow through the system. Gypsum deposits are present in 32 of the 48 conterminous United States, and they underlie about 35-40% of the land area; they are reported in rocks of every …

Gypsum Karst Of The Pre-Ural Region, Russia, Vjacheslav Andrejchuk

International Journal of Speleology

Description of the gypsum karst of the pre-Ural region in Russia, with special emphasis on speleogenesis.

The Steady Boundary Layer Due To A Fast Vortex, Andrew J. Bernoff, Harald J. H. M. Van Dongen, Seth Lichter

All HMC Faculty Publications and Research

A point vortex located above and convected parallel to a wall is an important model of the process by which a boundary layer becomes unstable due to external disturbances. Often it has been assumed that the boundary layer due to the passage of the vortex is inherently unsteady. Here we show that for a vortex convected by a uniform shear flow, there is a steady solution when the speed of the vortex c_v is sufficiently fast. The existence of the steady solution is demonstrated analytically in the limit of large vortex velocity (c_v→∞) and numerically …

Combinatorics And Campus Security, Arthur T. Benjamin

All HMC Faculty Publications and Research

One day I received electronic mail from our director of campus security [Gilbraith 1993]:

"I have a puzzle for you that has practical applications for me. I need to know how many different combinations there are for our combination locks. A lock has 5 buttons. In setting the combination you can use only 1button or as many as 5. Buttons may be pressed simultaneously and / or successively, but the same button cannot be used more than once in the same combination.

I had a student (obviously not a math major) email me that there are only 120 possibilities, but …

Existence Results For Semipositone Systems, V. Anuradha, Alfonso Castro, Ratnasingham Shivaji

All HMC Faculty Publications and Research

We study existence of positive solutions to the coupled-system of boundary value problems of the form

-Δu(x) = λf(x,u,v); x ∈ Ω

-Δv(x) = λg(x,u,v); x ∈ Ω

u(x) = 0 = v(x); x ∈ ∂Ω

where λ > 0 is a parameter, Ω is a bounded domain in R^N; N ≥ 1 with a smooth boundary ∂Ω and f,g are C^1 function with at least one of f(x_0,0,0) or g(x_0,0,0) being negative for some x_0 ∈ Ω (semipositone). We establish our existence results using the method of sub-super solutions. We also discuss non-existence results for λ small.

Experimental And Theoretical Investigation Of Recombination Pumped X-Ray Lasers Driven By High-Intensity, Short Pulse Lasers, Thomas D. Donnelly, L. Da Silva, R. W. Lee, S. Mrowka, M. Hofer, R. W. Falcone

All HMC Faculty Publications and Research

We have experimentally investigated a recombination-pumped soft-x-ray laser on a Lyman-α transition (135 Å) of hydrogenlike lithium. Furthermore, we have modeled the dynamics of this system, including the effects of the multipeaked electron distribution function that is obtained from the sequential, optical-field ionization of an atom. We compare the predictions of our model and our experimental results.

An Nmr Investigation Of The Effect Of Hydrogen Bonding On The Rates Of Rotation About The C-N Bonds In Urea And Thiourea, Karl A. Haushalter, Janice Lau, John D. Roberts

All HMC Faculty Publications and Research

The interaction between urea and tetrabutylammonium acetate was investigated in dimethylformamide/ dimethyl sulfoxide solutions using ¹H and 15^N NMR. The chemical-shift behavior of the urea protons is consistent with a urea-acetate hydrogen-bonded complex involving both carboxylate oxygens and the urea hydrogens trans to the carbonyl oxygen with K_assoc = 120 ± 10. Line shape analysis of the temperature-dependent ¹H NMR spectra show that ∆G^‡ for rotation about the C-N bond of urea changes only slightly from 11.0 ± 0.1 to 11.2 ± 0.1 kcal/mol on 1:1 molar addition of tetrabutylammonium acetate to a dilute solution of urea. A parallel investigation …

Intraocular Lens Case Designs, Donald S. Remer, Stephen S. Davis, Michael Bak '95, Ken Kalafus, Ilan Sabar, Khannan Suntharam, William Washington, Yu-Tung Wong

All HMC Faculty Publications and Research

IOLAB Corporation makes two types of intraocular lenses for the replacement of cataracts: one from polymethyl methacrylate (PMMA) and a newer one from silicone. IOLAB ships the lens to the doctor in a two-piece case made from polycarbonate. At a price of $0.53 per case, IOLAB spends about $270,000 per year on lens cases (based on 1994 purchases of 500,000 cases). IOLAB asked us to reduce the cost of the existing lens case and to design a new case to protect and fold the silicone lens. We designed three items.

Increasing Esl Student Language Production And Altering The Affective Climate In A Mountain Community High School, Linda Louise Hanneman

Theses Digitization Project

No abstract provided.

Meyer Jerison, 1922-1995, Leonard Gillman, Melvin Henriksen

All HMC Faculty Publications and Research

Memories and biography of mathematician Meyer Jerison (b. November 28, 1922 - d. March 19, 1995).

Modular Spaces And K-Widths, Asuman Güven Aksoy, Grzegorz Lewicki

CMC Faculty Publications and Research

In this paper, we show that the ball measure of noncompactness of a modular space X_p is equal to the limit of its K -widths when p is a left continuous, s-convex modular function, without any ∆₂-condition. We also obtain a similar result for SF-spaces, when the SF-norm N is uniformly continuous.

Task Ll Report, Part 2: Evaluation Of Water Supplies In The Red River, Dix River, And Mainstem Watersheds Of The Kentucky River, D. I. Carey, A. W. Fogle, L. G. Morris

KWRRI Research Reports

This study was part of a larger study of water supplies throughout the Kentucky River Basin conducted by the Kentucky Water Resources Research Institute for the Kentucky River Authority. This report examines municipal and private water supplies in the Red River, Dix River, and mainstem Kentucky River watersheds. Municipal supplies which depend on the mainstem Kentucky River, and municipal and private supplies in the North, South, and Middle Fork watersheds of the Kentucky River basin are examined in separate reports.

Water Use Estimation And Forecasting For The Kentucky River Basin: A Preliminary Draft Report, Glenn C. Blomquist, William Hoyt, Dayuan Hu, Colleeen G. Scott

KWRRI Research Reports

We estimate aggregate monthly water use for summer, peak demand and nonsummer off-peak demand periods for the Kentucky River Basin. Using Kentucky Division of Water use data, U.S. Census data for county demographic and economic conditions, and U.S. Weather Service data for weather conditions we estimate use for the 1970-1993 period. Our model allows for idiosyncratic effects of each of the 27 counties in the sample. We find factors such as population and manufacturing employment effect use and temperature and rainfall in current and preceding months effect use during the summer, peak period. The model predicts well within the sample …

Executive Summary: Kentucky River Basin Water Supply Assessment Study, L. Ormsbee

KWRRI Research Reports

This is a high level summary of the KWRRI study assessing the water supply concerns in the Kentucky River Basin.

Evaluation Of Water Supplies In The Upper Forks Of The Kentucky River Basin, Kentucky Water Resource Research Institute

KWRRI Research Reports

This study examined municipal and private water supplies in the Upper Forks of the Kentucky River. Municipal water systems in Letcher, Knott, Leslie, and Breathitt counties in the North Fork Kentucky River Basin, Leslie county in the Middle Fork Kentucky River Basin, and Owsley and Clay counties in the South Fork Kentucky River were examined for current and projected water supply adequacy and water system needs. Eight municipal water suppliers- Fleming-Neon Water Company, Whitesburg Municipal Water, Hindman Municipal Water Works, Hazard Water Department, Jackson Municipal Water Works, Booneville Water and Sewer, and Manchester Water Works- and three purchasing districts: Vicco …

Task V Report- Estimation Of The Responsiveness Of Water Use To Changes In Rates: A Methodology And Final Estimates Using Kawc Data, G. Blomquist, W. Hoyt

KWRRI Research Reports

No abstract provided.

Convex Functions, Susanna Maria Zagar

Theses Digitization Project

No abstract provided.

A Study Of Finite And Linear Elasticity, Fen Rui Johnson

Theses Digitization Project

No abstract provided.

Applications Of Hyperbolic Geometry In Physics, Scott Randall Rippy

Theses Digitization Project

The purpose of this study was to see how the fundamental properties of hyperbolic geometry applies in physics.

The Mandelbrot Set, Jeffrey Francis Redona

Theses Digitization Project

No abstract provided.

Semisimplicity For Hopf Algebras, Michelle Diane Stutsman

Theses Digitization Project

No abstract provided.

Torus Routing In The Presence Of Multicasts, Hiroki Ishibashi

Theses Digitization Project

No abstract provided.

An Overview Of Environmental Development In The Game Parks Of Kenya, Carolyn G. Ginter

Theses Digitization Project

Kenya has one of the oldest and most developed national park and reserve systems among developing nations in Africa. Kenya's ecosystems have felt the impact of tourists, from big game hunters to photographic safaris, for over a century. This project contains the research on which the author intends to base a future book about Kenyan ecoturism for the general public.