Physical Sciences and Mathematics Commons^™

Temporal Characterization Of A Self-Modulated Laser Wakefield, S.P. Le Blanc, M.C. Downer, R. Wagner, Shouyuan Chen, Anatoly Maksimchuk, G. Mourou, Donald P. Umstadter

Donald Umstadter Publications

The temporal envelope of plasma density oscillations in the wake of an intense (l∼4×10¹⁸ W/cm², λ = 1 μm) laser pulse (400 fs) is measured using forward Thomson scattering from a copropagating, frequency-doubled probe pulse. The wakefield oscillations in a fully ionized helium plasma (n_e = 3×10¹⁹ cm^-3) are observed to reach maximum amplitude ( δn_e/n_e∼0.1) 300 fs after the pump pulse. The wakefield growth ( 3.5 ps^-1) and decay ( 1.9 ps^-1) rates are consistent with the forward Raman …

Lissodelphis Peroni, Michael W. Newcomer, Thomas A. Jefferson, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

Order Cetacea, Suborder Odontoceti, Family Delphinidae. The subfamily Lissodelphinae has been proposed for this genus (Fraser and Purves, 1960), but it has not been universally accepted (Kasuya, 1973). There are two species in the genus: Lissodelphis peronii (southern right whale dolphin) and L. borealis (northern right whale dolphin). Lissodelphis peronii currently contains no subspecies.

Comparison Of The Temperature-Dependent Electronic Structure Of The Perovskites La0.65Ca0.35Mno3 (A=Ca, Ba), D.N. Mcilroy, C. Waldfried, Jiandi Zhang, Jaewu Choi, F. Foong, Sy_Hwang Liou, Peter A. Dowben

Peter Dowben Publications

The electronic band structure and the local screening effects of the transition-metal perovskites La_0.65A_0.35MnO₃ (A=Ba and Ca ) have been examined across the coupled magnetic-metallic phase transition using the techniques of angle-resolved photoemission, resonance photoemission, and inverse photoemission. Temperature-dependent band shifts of the e_g and t_2g bands of La_0.65Ca_0.35MnO₃ have been observed. These changes in the observed electronic structure correlate with the phase transition, and are in qualitatively agreement with the predicted behavior associated with double exchange coupled with a dynamic Jahn-Teller distortion. Similar shifts were not observed …

Strain-Induced Distortion Of The Bulk Bands Of Gadolinium, Carlo Waldfried, D.N. Mcilroy, C.W. Hutchings, Peter A. Dowben

Peter Dowben Publications

Thin films of gadolinium, approximately 8 ML thick, have been grown on the corrugated (112) surface of molybdenum and the electronic structure has been investigated with angle-resolved photoelectron spectroscopy. The unfavorable lattice match between the ‘‘steplike’’ Mo(112) substrate and the preferred hexagonally ordered Gd film results in an incommensurate Gd structure that appears to be ordered, but strained along the direction of the corrugations. The hexagonal Gd lattice is expanded by more than 20% along the ‘‘step’’ lines of the substrate, as determined from the reduced Brillouin-zone size along the ΓΣM high-symmetry line and low-energy electron diffraction. The induced strain …

Neutron Scattering Study Of Transverse Magnetism, Christian Binek, T. Kato, Wolfgang Kleemann, O. Petracic, D. Bertrand, F. Bourdarot, P. Burlet, H. Aruga Katori, K. Katsumata, K. Prokes, S. Welzel

Christian Binek Publications

In order to clarify the nature of the additional phase transition at H₁ (T) < H_c (T) of the layered antiferromagnetic (AF) insulator FeBr₂ as found by Aruga Katori et al. (1996) we measured the intensity of different Bragg-peaks in different scattering geometries. Transverse AF ordering is observed in both AF phases, AFI and AFII. Its order parameter exhibits a peak at T₁ = T (H₁) in temperature scans and does not vanish in zero field. Possible origins of the step-like increase of the transverse ferromagnetic ordering induced by a …

The Effects Of Wet Meadow Fragmentation On Grassland Birds, Christopher J. Helzer

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Histomorphological Responses Of Red Shiner (Cyprinella Lutrensis) To Atrazine, Terbufos, And Their Mixture, Ibrahim A. Messaad

School of Natural Resources: Dissertations, Theses, and Student Research

Alterations of normal histomorphology of fish tissues, behavior, and thermal tolerance are recognized by environmental toxicologists and fish biologists as powerful tools indicating diverse biochemical and physiological changes. Toxicity of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), terbufos (S-(((1,1-dimethyl-ethyl)thio)methyl)O,O-diethyl phosphorodithioate), and their mixture to red shiner (Cyprinella lutrensis) at 23$\sp\circ$C and 30$\sp\circ$C was investigated in 14-d bioassays after 14-d acclimation. During the bioassays, fish behavior, indications of toxicosis, and external anomalies were observed. After the bioassays, the critical thermal maximum (CTM) was determined. Fish also were preserved for examinations of gill, liver, and kidney tissues using scanning electron microscopy (SEM) and light microscopy (LM). SEM …

The Prairie Naturalist Volume 28, No. 4. December 1996

The Prairie Naturalist

IMPLANTED MICROCHIPS USED TO INDIVIDUALLY IDENTIFY BLACK-FOOTED FERRETS IN MONTANA ▪ R. Stoneberg

GRAY WOLF STATUS IN NORTH DAKOTA ▪ D. S Licht and L. E. Huffman

VARIATION IN SELECTION OF MICROHABITATS BY MERRIAM'S TURKEY BROOD HENS ▪ M. A. Rumble and S. H. Anderson

SURVIVAL AND REPRODUCTIVE CHRONOLOGY OF FEMALE RING-NECKED PHEASANTS IN SOUTH DAKOTA ▪ A. P. Leif

EFFECTS OF LOGGING SLASH ON ASPEN REGENERATION IN GRAZED CLEARCUTS ▪ M. A. Rumble, T. Pella, J. C. Sharps. A. V. Carter, and J. B. Parrish

BOOK REVIEWS

The Poetry of Ecoregions ▪ J. Pastor

Saving Texas' Rare Ones ▪ …

Water Current, Volume 28, No. 6, December 1996

Water Current Newsletter

UNL Remediation Research Gets NSF/EPSCoR Funding Boost
From the Director: Implementation Plans Continue for "School of Natural Resources;" New Staff Joins Water Center
Drought, Climate Change Effects on Aquifer Are Topics for 26th Water Conference
New Database Aids Navigating Platte River Information
Applicator Training Sessions to Start Again Next Month
"When the Rains Don't Come" Subject of Seminar Series
Spaldings Speak at Korea's Cheju University

The Probe, Issue 172 – December 1996

The Probe: Newsletter of the National Animal Damage Control Association

A Conservation Dilemma-The Free-Ranging Domestic Cat, by John Coleman, Stan Temple, and Scott Craven, Department of Wildlife Ecology, University of Wisconsin, Madison
9th Northern Furbearer Conference on May 22-23,1997 in Yellowknife, Northwest Territories, Canada: Second Announcement / First Call for Papers
Darrel Juve to Retire
Wolves Attack People in Kazakhstan
Video Review: "Basic Coyote Control" produced by Tom Beaudette of High Country Control
Australian Wants to Unleash Fatal Virus on Felines

Abstracts Published at the 3rd Annual Conference of The Wildlife Society:

Leghold Traps: An Overview of Social and Biological Issues Behind the Controversy, William F. Andelt, Robert L. Phillips, …

Assessment Of The Status Of Harbor Porpoise (Phocoena Phocoena) In Oregon And Washington Waters, S. Osmek, J. Calambokidis, J. Laake, P. Gearin, R. Delong, J. Scordino, S. Jeffries, R. Brown

United States Department of Commerce: Staff Publications

The status of harbor porpoise, Phocoena phocoena, is reviewed for stocks in Oregon and Washington waters, and the adjacent transboundary waters of southern British Columbia, Canada, emphasizing the most recent data on their geographic range, population structure, distribution, population size, trends in abundance, and reproductive biology. This information is used to determine if the annual rate of incidental mortality and serious injury in gill-net fisheries from 1990-94 could be at a biologically significant level.

In the eastern North Pacific Ocean, harbor porpoise are found near the coast, generally in water depths of less than 200 m. Differences in harbor porpoise …

An Inline Optical Electron Polarimeter, K. W. Trantham, Timothy J. Gay, R. J. Vandiver

Timothy J. Gay Publications

The design and operation of a simple inline optical electron polarimeter is presented. It is based on exchange excitation of ground state neon atoms. The electron polarization is determined from the degree of circular polarization of the subsequent 2p⁵3p ³D₃→2p⁵3s ³P₂ (6402 Å) fluorescence. This device can characterize both longitudinally and transversely polarized electron beams in a nondestructive fashion, and is inexpensive and easily constructed.

Stars Classified As Constant In The General Catalogue Of Variable Stars, Ii, Edward G. Schmidt

Edward Schmidt Publications

Photometric observations have been made of 36 stars classified as CST or CST: in the General Catalogue of Variable Stars. Six of these stars are found to vary and three others were deemed possible variables. Of the certain variables, two (MR Her and TY Sge) are red pulsators, one (V1585 Cyg) is a rapid irregular variable, one is apparently a short period Cepheid-strip star (V432 Oph), one is an eclipsing binary (AQ Boo), and one is of uncertain type (V351 Cyg). The stars we have observed as MR Her and TY Sge are the same ones which were identified on …

The Behlen Observatory Variable Star Survey, Iv, Edward G. Schmidt, Anil Seth

Edward Schmidt Publications

Finding charts, accurate coordinates, and light curves are presented for 106 variable stars including 6 which are newly discovered. Parameters descriptive of the light curves are tabulated including periods for 16 stars which lacked them. The periods from the General Catalog of Variable Stars for ten stars were found to be seriously in error. The classification of the stars is discussed. Revisions or refinements of the classifications from the General Catalogue of Variable Stars are suggested for 20 stars and classifications are given for 7 which were previously unclassified. 15%-23% of the Bailey type ab RR Lyrae stars show scatter …

Fabrication Of N-Type Nickel Doped B5 C1+Δ Homojunction And Heterojunction Diodes, Seong-Don Hwang, Ken Yang, Peter A. Dowben, Ahmad A. Ahmad, N.J. Ianno, J.Z. Li, J.Y. Lin, H.X. Jiang, D.N. Mcilroy

Peter Dowben Publications

We have successfully nickel doped a boron carbide (B5C) alloy film. The nickel doped boron-carbide (Ni-B₅C_1+δ) thin films were fabricated from a single source carborane cage molecule and nickelocene [Ni(C₅H₅)₂] using plasma enhanced chemical vapor deposition. Nickel doping transforms the highly resistive undoped film from a p-type material to an n-type material. This has been verified from the characteristics of diodes constructed of Ni-B₅C_1+δ on both n-type silicon and p-type B₅C. The homojunction diodes exhibit excellent rectifying properties over a wide range of temperatures. ©1997 …

Nanoscale Investigation Of Fatigue Effects In Pb(Zr,Ti)O3 Films, Alexei Gruverman, O. Auciello, H. Tokumoto

Alexei Gruverman Publications

Scanning force microscopy has been used to perform a comparative nanoscale study of domain structures and switching behavior of Pb(Zr_xTi_1-x)O₃ (PZT) thin films integrated into heterostructures with different electrodes. The study revealed a significant difference between polarization state of as-deposited PZT films on RuO₂ and Pt electrodes. The PZT/RuO₂ films exhibit polydomain crystallites and show almost symmetric switching behavior, while the PZT/Pt films are mainly in a single polarity state and exhibit highly asymmetric piezoelectric hysteresis loops. Formation of unswitchable polarization within the grains of submicron size as a result of fatigue process …

Photoionization Of Atoms, Anthony F. Starace

Anthony F. Starace Publications

This chapter outlines the theory of atomic photoionization, and the dynamics of the photon-atom collision process. Those kinds of electron correlation that are most important in photoionization are emphasized, although many qualitative features can be understood within a central field model. The particle-hole type of electron correlations are discussed, as they are by far the most important for describing the single photoionization of atoms near ionization thresholds. Detailed reviews of atomic photoionization are presented in Refs. [I] and 121. Current activities and interests are well-described in two recent books [3,4]

Prairie Legacies - Mammals, Russell A. Benedict, Patricia W. Freeman, Hugh H. Genoways

School of Natural Resources: Faculty Publications

Few North American ecosystems have been as dramatically altered by humans as the prairies of the Great Plains. Occupying the immense interior of North America, these deceiving grassland oceans hid their complexity and diversity from many early travelers who saw this area merely as an obstacle to overcome in their westward journeys. But for the careful observer, prairies hold a tremendous quantity of life, arranged in a diverse mosaic of patches ranging in scale from minute anthills to the vastness of the Nebraska Sandhills or Kansas Flint Hills. Not only is a given ridgetop subdivided into a number of areas …

Center For Sustainable Agricultural Systems Newsletter, November/December 1996

Center for Sustainable Agricultural Systems -- Newsletters 1993-2000

Contents:

Nebraska IMPACT Project Update

North Central Region Evaluates Sustainable Agriculture Training

Annual Meetings in Nebraska to Showcase Innovative Strategies for Successful Farming

Integrated Farm Update: To Graze or Not to Graze?

USDA Announces Policy Directive Committing Agency to Sustainable Ag

Transformation of Land Grant Universities

Food Circles: A Bioregional Approach

Fund for Rural America

Ag Production and Nutrition Conference

Richard Olson Named Presidential Fellow

Electron Energy Distributions From Multiple Ionization In 20–120-Kev H+ + Ar Collisions, Yang-Soo Chung, M. Eugene Rudd

M. Eugene Rudd Publications

Energy-analyzed secondary electrons from H⁺ + Ar collisions at eight proton energies from 20 to 120 keV were detected in coincidence with recoil ions of charge states 1–3. The charge states were distinguished by time-of-flight measurements and the electron energies were analyzed by a newly designed electrostatic analyzer of the low-pass high-pass filter type which has a large (~1.45π steradian) solid angle acceptance. For each of nine electron energies from 10 to 160 eV, the ionizing events associated with each residual ion charge state were counted. The electron energy dependence of the charge-state ratios and the average charge determined …

The Probe, Issue 171 – November 1996

The Probe: Newsletter of the National Animal Damage Control Association

Park Service Thwarts Cat Allies, by Marilyn Davis, Native Species Network, Bodega Bay, California
Jim Miller Elected VP of Wildlife Society
ADC Aerial Hunting Accident Kills 2
Obituary: Carl R. Gustavson
HSUS Former Employee File Lawsuits
Rats Shut Down Internet at Stanford
Call for Papers: A Symposium on Mammal Trapping August 1997 in Edmonton, Alberta
Fur in Cyberspace: The Fur Institute of Canada announces it has established a site on the World Wide Web, at the following address: http://www.fur.ca.
Book Review: Beaver and Otter: Open Water Techniques, by Charles Dobbins 1992. Beaver Pond Publishing and Printing, P.O. Box 224, Greenville, …

Two-Center Effects In Ion-Atom Collisions: A Symposium In Honor Of M. Eugene Rudd, Lincoln, Ne May 1994 — Contents And Preface, Timothy J. Gay, Anthony F. Starace

Anthony F. Starace Publications

Following a distinguished career in atomic physics, sketched in the accompanying biography, M. Eugene Rudd retired From the faculty of the University of Nebraska in the spring of 1993. In order to celebrate his many research accomplishments, a two day scientific conference, held on 13-14 May 1994, was organized in Lincoln. It was felt that the special spirit that Rudd brought to the lab would be highlighted by a conference designed to analyze in detail a subject of current research in which he was a pioneer: two center-effects in ion-atom ionizing collisions.

Prior to 1980, primarily as a result of …

Biographical Sketch Of M. Eugene Rudd, Robert Katz, Duane H. Jaecks

Department of Physics and Astronomy: Faculty Publications

Dr. Rudd's research in atomic collision physics has been characterized by originality and thoroughness. He has written review articles and chapters in the Encyclopedia of Physics - and elsewhere, and is a co-author on a book on atomic collisions. He has published more than 75 refereed research papers, many of which were of seminal importance. He was the first to study systematically the dependence of the probability for electron emission in ion-atom collisions on the incident ion's energy, and on the ejected electron's energy and angle of emission. In 1964 he made the first experimental observation of doubly excited atomic …

A Novel Multilayer Circuit Process Using Yba2cu3ox /Srtio3 Thin Films, H.Q. Li, R.H. Ono, L.R. Vale, D.A. Rudman, Sy_Hwang Liou

Sy-Hwang Liou Publications

A process combining hydrofluoric acid (HF) and Ar⁺ ion milling has been used to make YBa₂Cu₃O_χ/SrTiO₃/YBa₂Cu₂O_χ (YBCO/STO/YBCO) multilayer test circuits. Low-angle steps can be readily etched in STO and YBCO films with this process. YBCO lines crossing 5° steps have about the same critical temperature T_c (89–90 K) and critical current density J_c (>1X10⁶ A/cm² at 86 K) as lines on planar surfaces. Via connections have the same T_c as other circuit components and adequate critical currents for most circuit …

Current Status Of The Saddle-Point Model, Timothy J. Gay

Timothy J. Gay Publications

The saddle-point model of ionizing ion-atom collisions is based on the idea that when a charged projectile ionizes target electrons. some of the ejected electrons find themselves on the transient, moving saddle-point of Coulomb potential with a velocity that matches that of the saddle point. Feeling no force at this position, they "ride" the saddle out of the collision volume and are thus ionized. In the case of the prototypical H⁺ + H system, or in any proton–neutral target collision, the saddle point moves at half the projectile velocity, so these electrons are often referred to as "v/2" electrons. …

Auger Electron Spectroscopy Of Free Argon Clusters, A. Knop, D. N. Mcilroy, Peter A. Dowben, E. Rühl

Peter Dowben Publications

Auger electron spectra and Auger yields of free argon clusm in the Ar(2p) excitation regime are reported. The Auger yield spectra show characteristic changes as a function of cluster size. The results indicate that the Auger yield signal originates primarily from the surface of the cluster. The results are compared to bulk-sensitive experimental techniques, such as total electron yields (TEY), zero kinetic energy electron (ZEKE) spectra for variable size clusters, as well as Auger yield spectra of condensed argon multilayers.

Radial Dose Distributions In The Delta-Ray Theory Of Track Structure, Francis A. Cucinotta, Robert Katz, John W. Wilson, Rajendra R. Dubey

Department of Physics and Astronomy: Faculty Publications

The radial dose distribution from delta rays, fundamental to the delta ray theory of track structure, is recalculated. We now include the model of Rudd for the secondary electron spectrum in proton collisions. We include the effects of electron transmission through matter and the angular dependence of secondary electron emission. Empirical formulas for electron range versus electron energy are intercompared in a wide variety of materials in order to extend the track structure theory to arbitrary media. Radial dose calculations for carbon, water, silicon, and gold are discussed. As in the past, effective charge is used to scale to heavier …

Age Classification Of Laughing Gulls Based On Summer Plumage, Jerrold L. Belant, Richard A. Dolbeer

USDA Wildlife Services: Staff Publications

We described quantitatively 19 summer plumage characteristics and bill and foot pigmentation of 247 known-age Laughing Gulls (Larus atricilla) collected in New York during 1992-1994. There were no differences in characteristics measured for male and female Laughing Gulls. Ninety percent of 2-yr-old Laughing Gulls and 96% of ≥ 3-yr-old birds had full hoods. Fifty-seven percent of 2-yr-old Laughing Gulls possessed at least partial tail bands in contrast to 4% of 3-yr-old and 0% of ≥ 4-yr-old gulls. Thus 2-and ≥ 3-yr-old Laughing Gulls cannot be separated reliably by the presence or absence of a tail band. Pink pigmentation on the …

Food Security In The Southern African Development Community States, Joshua Chigodora

Drought Network News (1994-2001)

The 1995–96 cereal harvest in the Southern African Development Community (SADC) is the best within the last ten years. Provisional assessments project a regional maize surplus of 2.08 million tons, a 72% increase in production over the previous year’s harvest. Overall cereal production substantially increased in all countries except Tanzania, where the current cereal forecast of 3.73 million tons is a 14% drop from last year’s output of 4.34 million tons. Of special note are the exceptionally large increases in the area planted in cereals in war-ravaged Angola and Mozambique, for the first time in many years. Production trebled in …

Moisture Deficit Index Evaluated For Dry Regions Of India, K. K. Nathan, S. K. Sinha

Drought Network News (1994-2001)

In India, about 70% of the cultivable land is rainfed. This includes areas where crops are rarely affected by drought and areas where crops experience moisture stress and often fail. The regions with the latter characteristics are often called dryland areas and the agriculture so practiced there is known as dryland agriculture. About 35% of the total cultivable land belongs in this category. To determine the magnitude of water deficiency in these regions, the moisture deficit index (MDI) has been evaluated for dryland stations in India. The MDI is usually determined on the basis of annual precipitation and annual potential …