Physical Sciences and Mathematics Commons^™

Observation Of The Plasma Channel Dynamics And Coulomb Explosion In The Interaction Of A High-Intensity Laser Pulse With A He Gas Jet, G.S. Sarkisov, V. Yu. Bychenkov, V.T. Tikhonchuk, Anatoly Maksimchuk, Shouyuan Chen, R. Wagner, G. Mourou, Donald P. Umstadter

Donald Umstadter Publications

We report the first interferometric observations of the dynamics of electron–ion cavitation of relativistically self-focused intense 4 TW, 400 fs laser pulse in a He gas jet. The electron density in a channel 1 mm long and 30 mm in diameter drops by a factor of approximately 10 from the maximum value of ~8x10¹⁹ cm²³. A high radial velocity of the plasma expansion, ~3.8x10⁸ cm/s, corresponding to an ion energy of about 300 keV, is observed. The total energy of fast ions is estimated to be 6% of the laser pulse energy. The high-velocity radial plasma …

Nanoscale Imaging Of Domain Dynamics And Retention In Ferroelectric Thin Films, Alexei Gruverman, H. Tokumoto, A. S. Prakash, S. Aggarwal, B. Yang, M. Wuttig, R. Ramesh, O. Auciello, T. Venkatesan

Alexei Gruverman Publications

We report results on the direct observation of the microscopic origins of backswitching in ferroelectric thin films. The piezoelectric response generated in the film by a biased atomic force microscope tip was used to obtain static and dynamic piezoelectric images of individual grains in a polycrystalline material. We demonstrate that polarization reversal occurs under no external field (i.e., loss of remanent polarization) via a dispersive continuous-time random walk process, identified by a stretched exponential decay of the remanent polarization.

Measurement Of The Decay Amplitudes And Branching Fractions Of B → J/Ψ K* And B → J/Ψ K Decays, C. P. Jessop, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

Using data taken with the CLEO II detector at the Cornell Electron Storage Ring, we present the first full angular analysis in the color-suppressed modes B⁰ → J/Ψ K ^*0and B⁰ → J/Ψ K^*+. This leads to a complete determination of the decay amplitudes of these modes including the longitudinal polarization Γ_L/Γ= 0.52 ± 0.07 ± 0.04 and the P wave component │P│²= 0.16 ± 0.08 ± 0.04. In addition, we update the branching fractions for B → J/Ψ K and B → J/Ψ K …

Stern-Gerlach Effect For Electron Beams, Herman Batelaan, Timothy J. Gay, J. J. Schwendiman

Timothy J. Gay Publications

The conflict between Bohr’s assertion that the magnetic moment of the electron cannot be measured with experiments based on the concept of classical trajectories, and the measurement of the magnetic moment of electrons in a modified Penning trap by Dehmelt et al. has led us to reevaluate other implications of Bohr’s assertion. We show that, contrary to the analysis of Bohr and Pauli, the assumption of classical trajectories in a Stern-Gerlach–like device can result in a high degree of spin separation for an electron beam. This effect may persist within a fully quantum-mechanical analysis. The magnetic fields considered are such …

The Prairie Naturalist Volume 29, No.4. December 1997

The Prairie Naturalist

BUTTERFLY SPECIES IN NATIVE PRAIRIE AND RESTORED PRAIRIE ▪ D. M. Debinski and A. M. Babbit

BACK-CALCULATED LENGTH-AT-AGE ESTIMATES FROM TWO SCALE RADII ▪ K. L. Hurley, K. L. Pope, and D. W. Willis

DIET OF NORTH DAKOTA ELK DETERMINED FROM RUMEN AND FECAL ANALYSES ▪ R. G. Osborn, J. A. Jenks, and W. F. Jensen

INTERSPECIFIC COMPETITION FOR FOOD BETWEEN WHITE-FOOTED MICE AND EASTERN WOODRATS ▪ B. G. Aloiau, D. M. Post, and E. A. Home

NESTING PIPING PLOVER AND LEAST TERN ON THE KANSAS RIVER ▪ W. H. Busby, D. W. Mulhern, P. G. Kramos, and D. A. …

Water Current, Volume 29, No. 6, December 1997

Water Current Newsletter

New Equipment Enhances Water Sciences Laboratory's Research Capabilities
From the Director: USGS/NIWR Cooperation, Joint Programming Increasing; NRI Budget Reductions
27th Water Conference Begins Three-Year Look at "Nebraska Water 2000"
Annual Seminar to Examine Interrelationship of Water, Native Grasslands and Wetlands
Pesticide Container Recycling Hits Six Year Peak
Audubon Launches State Office
Environmental Decision Making Conference
MidAmerica GIS Symposium Comes to Cornhusker Hotel in May
Symposium Proceedings Available from Great Plains Foundation
Water News Briefs
Tips on Water Conservation
Useful Resources
Source Water Protection Conference Coming to Dallas in April
UNL Faculty Bring Home ASAE Educational Blue Ribbons

Freezing Of Confined Water: A Bilayer Ice Phase In Hydrophobic Nanopores, Kenichiro Koga, Xiao Cheng Zeng, Hideki Tanaka

Xiao Cheng Zeng Publications

Molecular dynamics simulations were performed to study the phase behavior of a thin film of water confined to a slit nanopore with smooth walls. A first-order water-to-ice freezing transition has been observed. The resulting ice, which is a crystal of bilayer consisting of rows of distorted hexagons, does not resemble any ice crystals found so far. The confined water contracts upon freezing when the confinement load is low ( ∼0.5 kbar) and expands when the load is high (10 kbar). The residual entropy of the bilayer ice can be calculated exactly, which is about half of the entropy of the …

The Probe, Issue 183 - December 1997

The Probe: Newsletter of the National Animal Damage Control Association

Contents:
Animal Rights Revisited
Calendar of Upcoming Events
Reports From the 4th Annual Conference of The Wildlife Society
Techniques for Managing Predation on Domestic Livestock and Big Game Animals
Attitudes of Private and Public Land Managers in Wyoming Toward Beaver
Grizzly Bear-Cattle Interactions on Two Cattle Allotments in Northwest Wyoming
The Effects of Wolf Colonization on Coyote Behaviors
Video Review: “Rob Erickson’s Live Trapping Urban Beaver, Vols. 1-2”
Reed-Joseph Donates to NADCA
Riot Police Quell Big Mac Attack
Oregon Cougars on the Rise
Confronting Anti-Trap Initiatives
Current Status and Future Prospects for Mesurol as a Bird Repellent
Prescribed Predation Management: …

Electron-Impact Total Ionization Cross Sections Of Ch And C2H2, Yong-Ki Kim, M. Asgar Ali, M. Eugene Rudd

M. Eugene Rudd Publications

Electron-impact total ionization cross sections for the CH radical and C₂H₂ (acetylene) have been calculated using the Binary-Encounter-Bethe (BEB) model. The BEB model combines the Mott cross section and the asymptotic form of the Bethe theory, and has been shown to generate reliable ionization cross sections for a large variety of molecules. The BEB cross sections for CH and C₂H₂ are in good agreement with the available experimental data from ionization thresholds to hundreds of eV in incident energies.

Shielding Strategies For Human Space Exploration Chapter 9: Hze Interactions In Biological Materials, M. Eugene Rudd

M. Eugene Rudd Publications

It is shown that most of the energy deposited by fast charged particles traversing matter occurs through ionization, i.e., the ejection of electrons during the atomic collision. The important mechanisms of ionization are identified and several methods of calculating the relevant differential and total cross sections are described. These include both classical and quantum theoretical methods and two semi-empirical models. The calculational methods were intended only for light, bare-ion projectiles, and care must be exercised in extending them to heavy, dressed projectiles.

Low-Field Hole Mobility In A Photorefractive Polymer, Arosha Goonesekera, Stephen Ducharme, James M. Takacs, Lei Zhang

Stephen Ducharme Publications

We present the time-of-flight measurements of hole mobility in a photorefractive polymer composite as a function of temperature and applied electric field. The analysis shows that the temperature dependence of the low-field mobility is in apparent disagreement with the predictions of the Gaussian disorder model and also with polaron models.

Study Of The Decay Τ-→2Π-Π+3Π0ΝΤ, S. Anderson, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

The decay τ^-→2π^-π⁺3π⁰ν_τ has been studied with the CLEO II detector at the Cornell Electron Storage Ring. The branching fraction is measured to be (2.85 ± 0.56 ± 0.51) X 10^-4. The result is in good agreement with the isospin expectation but somewhat below the conserved-vectorcurrent prediction. We have searched for resonance substructure in the decay. Within the statistical precision, the decay is saturated by the channels τ^-→π^-2π⁰ων_τ, 2π^-π⁺ων_τ, and π^-2π⁰ων …

Limit On The Two-Photon Production Of The Glueball Candidate FJ(2220) At The Cornell Electron Storage Ring, R. Godang, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We use the CLEO detector at the Cornell e⁺e^- storage ring, CESR, to search for the two-photon production of the glueball candidate f_J (2220) in its decay to K_sK_s. We present a restrictive upper limit on the product of the two-photon partial width and the K_sK_s branching fraction, (Γ_γγ B_KsKs)_fJ(2220). We use this limit to calculate a lower limit on the stickiness, which is a measure of the two-gluon coupling relative to the two-photon coupling. This limit on stickiness …

Coordinate Regulation Of G- And C Strand Length During New Telomere Synthesis, Xinqing Fan, Carolyn Mary Price

Chemistry Department: Faculty Publications

We have used the ciliate Euplotes to study the role of DNA polymerase in telomeric C strand synthesis. Euplotes provides a unique opportunity to study C strand synthesis without the complication of simultaneous DNA replication because millions of new telomeres are made at a stage in the life cycle when no general DNA replication takes place. Previously we showed that the C-strands of newly synthesized telomeres have a precisely controlled length while the G-strands are more heterogeneous. This finding suggested that, although synthesis of the G-strand (by telomerase) is the first step in telomere addition, a major regulatory step occurs …

Search For The Decay Τ-→4Π-3Π+(Π0)ΝΤ, K. W. Edwards, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We have searched for the decay of the τ lepton into seven charged particles and zero or one π⁰. The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond to an integrated luminosity of 4.61 fb^-. No evidence for a signal is found. Assuming all the charged particles are pions, we set an upper limit on the branching fraction B(τ^-→4π^-3π⁺(π⁰) ν_τ) < 2.4X10^-6 at the 90% confidence level. This limit represents a significant improvement …

New Upper Limit On The Decay Η→E+E-, T. E. Browder, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We have searched for the rare decay of the η meson η→e⁺e^- using the CLEO II detector. The η’s were produced in e⁺e^- collisions with 10 GeV center-of-mass energy at the Cornell Electron Storage Ring (CESR). We find with 90% confidence the upper limit on the branching fraction B (η→e⁺e^-)<7.7×10^-5. The application of conventional elementary particle theory to this decay predicts a branching fraction of about 10^-9.

Determination Of The Michel Parameters And The Τ Neutrino Helicity In Τ Decay, J. P. Alexander, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

Using the CLEO II detector at the Cornell Electron Storage Ring operated at √s =10.6 GeV, we have determined the Michel parameters ρ, ξ, and δ in τ^±→l^±νν̅ decay as well as the τ neutrino helicity parameter h_vτ in τ^±→π^±π⁰ν decay. From a data sample of 3.02×106 produced τ pairs we analyzed events of the topologies e⁺e^-→τ⁺τ^-→(l^±νν̅)(π^±π⁰ν) and e⁺e^-→τ⁺τ^-→(π^±π⁰ν̅)(π^±π⁰ν). …

Center For Sustainable Agricultural Systems Newsletter, November/December 1997

Center for Sustainable Agricultural Systems -- Newsletters 1993-2000

Contents:

CSAS Publishes Book That Reviews Sustainable Ag Literature

NCR SARE Solicits PDP Proposals

Integrated Farm Update: Impact of Spring-grazing Crop Residues

Education in Scandinavia: from Farming to Food Systems

NSAS 1998 Annual Meetings

Ecosystems Provide Valuable "Services" Worth $33 Trillion

USDA Creates New Office of Pest Management

Sanet-mg Archives: A Valuable Resource

Steps Toward Determination Of The Size And Structure Of The Broad-Line Region In Active Galactic Nuclei. Xi. Intensive Monitoring Of The Ultraviolet Spectrum Of Ngc 7469, I. Wanders, Bradley M. Peterson, D. Alloin, T.R. Ayres, J. Clavel, D. Michael Crenshaw, K. Horne, Gerard A. Kriss, Julian Henry Krolik, Matthew A. Malkan, Hagai Netzer, Paul T. O'Brien, G.A. Reichert, P.M. Rodriguez-Pascual, W. Wamsteker, T. Alexander, K. S.J. Anderson, E. Benitez, N.G. Bochkarev, A.N. Burenkov, F.-Z. Cheng, S.J. Collier, A. Comastri, M. Dietrich, D. Dultzin-Hacyan, B.R. Espey, A. V. Filippenko, C. Martin Gaskell, I.M. George, M.R. Goad, L.C. Ho, Shai Kaspi, W. Kollatschny, Kirk T. Korista, Ari Laor, G.M. Macalpine, M. Mignoli, S.L. Morris, K. Nandra, S. Penton, Richard William Pogge, R.L. Ptak, J.M. Rodriguez-Espinoza, M. Santos-Lleo, A.I. Shapovalova, J.M. Shull, Stephanie A. Snedden, L.S. Sparke, G.M. Stirpe, W.-H. Sun, T.J. Turner, M.-H. Ulrich, T.-G. Wang, C. Wei, W.F. Welsh, S.-J. Xue, Z.-L. Zhou

C. Martin Gaskell Publications

From 1996 June 10 to July 29, the International Ultraviolet Explorer monitored the Seyfert 1 galaxy NGC 7469 continuously in an attempt to measure time delays between the continuum and emission-line fluxes. From the time delays, one can estimate the size of the region dominating the production of the UV emission lines in this source. We find the strong UV emission lines to respond to continuum variations with time delays of about 2_.^d3-3_.^d1 for Lyα, 2_.^d7 for C _IV λ1549, 1_.^d9-2_.^d4 for N _IV λ …

The Probe, Issue 182 - November 1997

The Probe: Newsletter of the National Animal Damage Control Association

Contents:
Exclosures Around Overflow Pipes and Trees Prevent Beaver Damage
Calendar of Upcoming Events
Deer, Dog in House Don’t Mix
Indiana Nuisance Operators Organize
Humane Trapping Standards Adopted
Video Review: “Dealing With Urban Wildlife: Learn How to Protect Your Home and Property from Wildlife Damage”
National Wildlife Refuge Improvement Act Passes
Fund for Animals Tries to Cross-Up Deer Hunting Priests
Beaver Damage Widespread
Texas Coyotes Damage Melons
Cranes, Hogs Decimate Corn
Fox Attacks California Woman
Drip Irrigation Damaged by Coyotes
Wolf Conflicts Sets Record in Minnesota

Dispersion Coefficients For Highly Excited Molecular States Of K2, Mircea Marinescu, Anthony F. Starace

Anthony F. Starace Publications

We report results of theoretical calculations for the dispersion coefficients associated with the long-range interaction of two ³⁹K atoms in the states ³⁹K(4s)- ³⁹K(5d,6d,7s). These results have been found by Wang et al. [Phys. Rev. Lett. 78, 4173 (1997)] to be in a good agreement with their measurements.

Terrestrial Natural Communities Of Nebraska - Version I, Gerry Steinauer, Steven B. Rolfsmeier

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

The Nebraska Natural Heritage Program has been collecting information and data including published literature, field observations and vegetation plot data over the last 10 years of development of Nebraska’s natural community classification. The classification contains 27 wetland and 36 upland communities including forest, woodland, shrubland, herbaceous, and sparsely vegetated (e.g. rock outcrop) types. The community types were distinguished primarily on plant species composition and to a lesser extent on soils, hydrology and geographic location. The classification contains descriptions of each community type that include dominant species, soils, range, and other ecological information. The classification is designed to be flexible enough …

Controlled Formation Of Weakly Bound Atomic Negative Ions By Electron Transfer From State-Selected Rydberg Atoms, M. Reicherts, T. Roth, A. Gopalan, M.-W. Ruf, Harmut Hotop, C. Desfrançuois, Ilya I. Fabrikant

Department of Physics and Astronomy: Faculty Publications

Using crossed atomic beams and mass spectrometric ion detection we have studied the formation of negative Ca ions in slow collisions between laser-excited state-selected Ne^**(ns; J = 2) and Ne^** (nd; J = 4) Rydberg atoms and ground state Ca atoms. The rate coefficients exhibit resonant behavior with maxima at an effective principal quantum number n^* of about 11.5 and an estimated peak value of about 10^-8 cm³ s^-1. Two different theoretical calculations, based on a curve-crossing model and on a modified adiabatic theory, respectively, yield n^{* …}

Observation Of Laser Satellites In A Plasma Produced By A Femtosecond Laser Pulse, S.A. Pikuz, Anatoly Maksimchuk, Donald Umstadter, M. Nantel, I. Yu. Skobelev, A. Ya. Faenov, A. Osterheld

Donald Umstadter Publications

Laser satellites are detected in the emission spectra of magnesium and aluminum plasmas produced by femtosecond laser pulses. This is made possible by the realization of picosecond time resolution in a highluminosity x-ray spectrograph with a spherically curved mica crystal. The temporal characteristics of these newly recorded spectral lines show unequivocally that they are formed as a result of nonlinear processes.

Cytochrome P450 And Organochlorine Contaminants In Black-Crowned Night-Herons From The Chesapeake Bay Region, Usa, Barnett A. Rattner, Mark J. Melancon, Clifford P. Rice, Walter Riley Jr., John D. Eisemann, Randy K. Hines

USDA Wildlife Services: Staff Publications

Black-crowned night-heron (Nycticorax nycticorax) offspring were collected from a relatively uncontaminated coastal reference site (next to Chincoteague National Wildlife Refuge, VA, USA) and two sites in the Chesapeake Bay watershed (Baltimore Harbor, MD and Rock Creek Park, Washington, DC, USA). Hepatic microsomal activities of benzyloxyresorufin-O-dealkylase and ethoxyresorufin-O-dealkylase were significantly elevated (up to sixfold and ninefold induction, respectively) in pipping embryos from the Baltimore Harbor colony compared to the reference site, whereas values in embryos from the Rock Creek Park colony were intermediate. Concentrations of organochlorine pesticides and metabolites in pipping embryos from both sites …

The Legal Roles And Responsibilities Of A Community Concerning Crop Depredation By White-Tailed Deer, Eric G. Darracq, Stephen R. Chapman

Eighth Eastern Wildlife Damage Management Conference (1997)

The interwoven issues of the legal roles and responsibilities that landowners (i.e., farmers, foresters, and hunters) and a state agency have to control deer densities in rural areas that directly affect crop depredation and various stakeholders will be addressed in this paper. Because unmanaged deer populations severely can damage agricultural crops, the financial cost of this deer damage is borne entirely by individual private landowners. The South Carolina Department of Natural Resources (SCDNR) is the regulatory state agency in South Carolina responsible for annually promulgating rules and regulations pertaining to white-tailed deer harvest by hunters. Even though deer are property …

An Evaluation Of Farmer Applications Of Deer Damage Controls, Peter Fritzell Jr., Glenn Dudderar, R. Ben Peyton

Eighth Eastern Wildlife Damage Management Conference (1997)

Damage to agricultural crops caused by white-tailed deer (Odocoileus virginianus) continues to be a significant concern of farmers in Michigan and elsewhere in the United States. Policy changes that promise to reduce deer numbers may be long in coming, but better application of available damage control techniques may be an immediate alternative for farmers awaiting relief. Conversations with farmers, extension agents, and wildlife professionals suggest that some damage control techniques are underutilized by Michigan farmers, whereas other techniques are applied with little success despite promising field trials. We investigated producers’ practices to identify common weaknesses in how deer …

Wildlife Damage To Agricultural Crops In Pennsylvania: The Farmers’ Perspective, Margaret C. Brittingham, Walter M. Tzilkowski, James M. Zeidler, Matthew J. Lovallo

Eighth Eastern Wildlife Damage Management Conference (1997)

Agricultural damage by wildlife is a major concern for both agricultural and wildlife agencies at the state and federal level. Our objective was to estimate wildlife damage to agricultural crops on a statewide basis. We sent questionnaires to 4,958 farmers and 1,003 were returned after 2 mailings. Twenty-five percent of farmers responding to our survey rated the level of wildlife damage to their crops as severe or very severe, 46% as moderate, and 29% had none or very little. Mean levels of crop loss to wildlife ranged from 6% for wheat to 10% for corn grain, and white-tailed deer ( …

Double-Crested Cormorant And Ring-Billed Gull Damage Management On Lake Champlain: Are Basin-Wide Objectives Achievable?, Richard Chipman, Dennis Slate, Larry Garland, David Capen

Eighth Eastern Wildlife Damage Management Conference (1997)

Ring-billed gulls ( Larus delewarensis) and double-crested cormorants ( Phalacrocorx auritus) have nested on Lake Champlain since 1949 and 1982, respectively. Recent increases in cormorant nesting populations and pioneering activities of both species to previously uncolonized islands have resulted in impacts related to accumulation of bird guano and interspecific competition with less common species. Of primary concern are: decreases in wildlife and plant diversity on islands; reduced aesthetics and property values of island associated with the loss of trees; and predation or competition for nesting space with other species such as the state-endangered common tern (Sterna hirundo …

Historical Forces Shaping Americans’ Perceptions Of Wildlife And Human-Wildlife Conflicts, Michael R. Conover, Denise O. Conover

Eighth Eastern Wildlife Damage Management Conference (1997)

From colonial times until the 19th century, the dominant American view of wildlife and its management was dualistic—wildlife species were divided into good animals (those which had commercial value or could be eaten) or bad animals (those which threatened the colonists’ safety or food supply). Philosophically, early colonial Americans believed that the environment was to be manipulated for man’s purposes. Under the impact of modernization, Darwinian influence, over-exploitation of resources, and environmentally-conscious professionals, Americans in the late 19th century began to appreciate the recreational value of wildlife and to develop a more protective attitude toward it. Still the dichotomy between …