Physical Sciences and Mathematics Commons^™

Facies Architecture Of The Crp-3 Drillhole, Victoria Land Basin, Antarctica, Christopher R. Fielding, T. R. Naish, K. J. Woolfe

Department of Earth and Atmospheric Sciences: Faculty Publications

The Cenozoic Victoria Land Basin (VLB) stratigraphic section penetrated by CRP-3 is mostly of Early Oligocene age. It contains an array of lithofacies comprising fine-grained mudrocks, interlaminated and interbedded mudrocks/sandstones, mud-rich and mud-poor sandstones, conglomerates and diamctites that are together interpreted as the products of shallow marine to possibly non-marine environments of deposition, affected by the periodic advance and retreat of tidewater glaciers. This lithofacies assemblage can be readily rationalised using the facies scheme designed originally for CRP-2/2A, and published previously. The uppermost 330 metres below sea floor (mbsf) shows a cyclical arrangement of lithofacies also similar to that recognised …

Depositional Environments For Strata Cored In Crp-3 (Cape Roberts Project), Victoria Land Basin, Antarctica: Palaeoglaciological And Palaeoclimatological Inferences, R. D. Powell, M. G. Laird, T. R. Naish, Christopher R. Fielding, L. A. Krissek, J.J. M. Van Der Meer

Department of Earth and Atmospheric Sciences: Faculty Publications

Cape Roberts Project drill core 3 (CRP-3) was obtained from Roberts ridge, a sea-floor high located at 77^oS, 12 km offshore from Cape Roberts in western McMurdo Sound, Antarctica. The recovered core is about 939 m long and comprises strata dated as being early Oligocene (possibly latest Eocene) in age, resting unconformably on ~116 m of basement rocks consisting of Palaeozoic Beacon Supergroup sediments. The core includes ten facies commonly occurring in five major associations that are repeated in particular sequences throughout the core and which are interpreted as representing different depositional environments through time. Depositional systems inferred …

Laser-Derived Particle Size Data From Crp-3, Victoria Land Basin, Antarctica: Implications For Sequence And Seismic Stratigraphy, Christopher R. Fielding, G. B. Dunbar, S. M. Bryce

Department of Earth and Atmospheric Sciences: Faculty Publications

Seven hundred and nineteen samples from throughout the Cainozoic section in CRP-3 were analysed by a Malvern Mastersizer laser particle analyser, in order to derive a stratigraphic distribution of grain-size parameters downhole. Entropy analysis of these data (using the method of Woolfe & Michibayashi, 1995) allowed recognition of four groups of samples, each group characterised by a distinctive grain-size distribution. Group 1, which shows a multi-modal distribution, corresponds to mudrocks, interbedded mudrock/sandstone facies, muddy sandstones and diamictites. Group 2, with a sand-grade mode but showing wide dispersion of particle size, corresponds to muddy sandstones, a few cleaner sandstones and some …

The Onset Of Arctic Sea-Ice Snowmelt As Detected With Passive- And Active-Microwave Remote Sensing, Richard R. Forster, David G. Long, Kenneth C. Jezek, Sheldon D. Drobot, Mark R. Anderson

Department of Earth and Atmospheric Sciences: Faculty Publications

Daily acquisitions from satellite microwave sensors can be used to observe the spatial and temporal characteristics of the Arctic sea-ice snowmelt onset because the initial presence of liquid water in a dry snowpack causes a dramatic change in the active and passive-microwave response. A daily sequence of backscatter coefficient images from the NASA scatterometer (NSCAT) clearly shows the spatially continuous progression of decreasing backscatter associated with snowmelt onset across the Arctic Ocean during spring 1997. A time series of the active NSCAT backscatter and a scattering index from the passive Special Sensor Microwave/Imager (SSM/I) show similar trends during the time …

Drawdown And Stream Depletion Produced By Pumping In The Vicinity Of A Partially Penetrating Stream, James J. Butler Jr., Vitaly A. Zlotnik, Ming-Shu Tsou

Department of Earth and Atmospheric Sciences: Faculty Publications

Commonly used analytical approaches for estimation of pumping-induced drawdown and stream depletion are based on a series of idealistic assumptions about the stream-aquifer system. Anew solution has been developed for estimation of drawdown and stream depletion under conditions that are more representative of those in natural systems (finite width stream of shallow penetration adjoining an aquifer of limited lateral extent). This solution shows that the conventional assumption of a fully penetrating stream will lead to a significant overestimation of stream depletion (> 100%) in many practical applications. The degree of overestimation will depend on the value of the stream leakance …

Small Oligocene Amphicyonids From North America (Paradaphoenus, Mammalia, Carnivora), Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

North American amphicyonid camivorans are important members of the mid-Cenozoic terrestrial carnivore community during the late Eocene to late Miocene (Duchesnean to Clarendonian). Species range in size from < 5 kg to > 200 kg. Among the smallest and rarest amphicyonids are Oligocene species of Paradaphoenus Wortman and Matthew, found at a few localities in the Great Plains and the Pacific Northwest. Paradaphoenus is known from only 10 individuals placed in 3 species (P. minimus; P. tooheyi. n. sp.; P. cuspigerus). representing a single lineage ranging from the Orellan to Arikareean. The existence of three skulls, one with associated mandibles, allows …

Reply To “Comment On ‘Photodetachment In Combined Static And Dynamic Electric Fields’”, A. R. P. Rau, Chitra Rangan

Physics Publications

While distortion of the initial negative-ion state by a strong static electric field can have observable effects, the effect attributed by the authors of the preceding Comment [Phys. Rev. A 64, 037401 (2001)] to a cross term between the detaching laser field and the static field is spurious, an artifact of their procedures. Other points of dispute are also clarified.

Optimally Shaped Terahertz Pulses For Phase Retrieval In A Rydberg-Atom Data Register, Chitra Rangan, P.H. Bucksbaum

Physics Publications

A terahertz pulse was designed to implement a search algorithm on a quantum data register. Phase information stored in a Rydberg wave packet was optimally retrieved through the interaction with the pulse. Careful attention was paid to the smooth switch on and switch off of the terahertz pulse. Furthermore, the possibility of designing an optimal pulse that can achieve not only a desired target state of an atom, but also implement a desired algorithm was shown.

Quantum Phase Retrieval Of A Rydberg Wave Packet Using A Half-Cycle Pulse, J. Ahn, D.N. Hutchinson, Chitra Rangan, P.H. Bucksbaum

Physics Publications

The half-cycle pulse (HCP) was used to search for information stored as phase in a Rydberg wave packet. Phase information coded in a Rydberg quantum register was retrieved through the impulsive interaction of HCP. In general, results of the study point to the use of HCPs as general tools for analysis for unknown wave packet.

Measurement Of The Hyperfine Structure Of The 4d2d 3/2,5/2 Levels And Isotope Shifts Of The 4p2p 3/2 ? 4d2d3/2 And 4p2p 3/2 ? 4d2d5/2 Transitions In Gallium 69 And 71, Steven J. Rehse, W.M. Fairbank Jr., S.A. Lee

Physics Publications

The hyperfine structure of the 4d2D3/2,5/2 levels of 69,71Ga is determined. The 4p2P3/2 ? 4d2D3/2 (294.50-nm) and 4p2P3/2 ? 4d2D5/2 (294.45-nm) transitions are studied by laser-induced fluorescence in an atomic Ga beam. The hyperfine A constant measured for the 4d2D5/2 level is 77.3 ± 0.9 MHz for 69Ga and 97.9 ± 0.7 MHz for 71Ga (3s errors). The A constant measured for the 4d2D3/2 level is -36.3 ± 2.2 MHz for 69Ga and -46.2 ± 3.8 MHz for 71Ga. These measurements correct sign errors in the previous determination of these constants. For 69Ga the hyperfine B constants measured for the …

Lamb Shift In He+: Resolution Of A Discrepancy Between Theory And Experiment, A. Van Wijngaarden, F. Holuj, Gordon W. F. Drake

Physics Publications

The Lamb shift in helium ions were investigated to verify or remove a discrepancy between theory and experiment by the anisotropy method. The method was used for the elimination of residual polarization sensitivity of the photon detectors. The results showed that the experimental value of a Lamb shift were in agreement with the theoretical values.

2001 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Tandem 4+3 Cycloaddition/Nucleophilic Trapping Reactions Of Butyne-1,4-Diether Dicobalt Hexacarbonyl Complexes, Yafan Lu, James R. Green

Chemistry and Biochemistry Publications

Butyne-1,4-diether hexacarbonyldicobalt complexes 1 undergo Lewis acid mediated 4+3 cycloadditions with allylsilanes, incorporating halide from the Lewis acid to give halocycloheptynes 3, 6, 7. A phenyl group may be incorporated in place of the halogen (to give 8) by use of benzene as solvent and with B(C6F5)(3) as the Lewis acid; chlorobenzene and toluene also participate in the process.

Cycloheptenyne Dicobalt Hexacarbonyl Complexes By Ring Closing Metathesis, James R. Green

Chemistry and Biochemistry Publications

Hexacarbonyldicobalt complexes of cycloheptenynes (4) may be prepared by the ring closing metathesis of the corresponding acyclic dienes (2) using Grubbs' catalyst, (Cy3P)(2)Cl2Ru=CHPh. A cyclooctenyne complex (8) has also been prepared in the strictly analogous manner.

The Virginia Wetlands Report Vol. 16, No. 1, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• The Stinging Sea Nettle (Jellyfish). William L. Roberts
• The VIMS Teaching Marsh: A Tidal Wetland Restoration and Education Project. Karen Duhring
• An Overview of Permitted Tidal Wetland Impacts for 2000. Tom Barnard
• Wetlands Management Symposium Focuses on Technology and Conservation

2001 Platte River Basin Ecosystem Symposium Proceedings

Water Current Newsletter

Over 75 people braved the wintry weather to attend the Eleventh Platte River Basin Ecosystem Symposium that convened in Kearney on 27 February 2001. Icy roads lead to cancellation of only 2 papers. Seventeen papers were presented and 5 posters were on display. Nebraska Public Radio and NTV News covered the event. The presentations were excellent and participants were well satisfied with not only the program but also the food. This year the symposium broadened its charge to include more discussion on community-based environmental protection, sustainable development, and policy-making. The Symposium was sponsored by the University of Nebraska Cooperative Extension …

Sclerosponges: Potential High-Resolution Recorders Of Marine Paleotemperatures, Gary B. Hughes, Charles W. Thayer

Statistics

Sclerosponges have great potential as seawater temperature recorders. These animals precipitate their skeletons in carbon and oxygen isotopic equilibrium with the surrounding seawater (Druffel and Benavides, 1986). Their skeletons also display chemical properties that vary directly with changes in environmental conditions. Lack of photosynthetic symbionts allows sclerosponges to live below the photic zone, providing the potential to investigate past marine conditions beyond the range of corals. Individual sponges live for several centuries, preserving archives of pre-and postindustrial seawater variations within single specimens (Hartman and Reiswig, 1980). Cross-correlation of successively older specimens could yield up to 2000 years of marine history. …

A Sequential Search Distribution: Proofreading, Russian Roulette, And The Incomplete Q-Eulerian Polynomials, Travis Herbranson, Don Rawlings

Mathematics

The distribution for the number of searches needed to find k of n lost objects is expressed in terms of a refinement of the q-Eulerian polynomials, for which formulae are developed involving homogeneous symmetric polynomials. In the case when k = n and the find probability remains constant, relatively simple and efficient formulas are obtained. From our main theorem, we further (1) deduce the inverse absorption distribution and (2) determine the expected number of times the survivor pulls the trigger in an n-player game of Russian roulette.

Back To Classics: Teaching Limits Through Infinitesimals, Todor D. Todorov

Mathematics

The usual ϵ, δ-definition of the limit of a function (whether presented at a rigorous or an intuitive level) requires a “candidate L” for the limit value. Thus, we have to start our first calculus course with “guessing” instead of “calculating”. In this paper we criticize the method of using calculators for the purpose of selecting candidates for L. We suggest an alternative: a working formula for calculating the limit value L of a real function in terms of infinitesimals. Our formula, if considered as a definition of limit, is equivalent to the usual ϵ, δ-definition but does not involve …

Extreme-Value Moment Goodness-Of-Fit Tests, Theodore P. Hill, Victor Perez-Abreu

Research Scholars in Residence

A general goodness-of-fit test for scale-parameter families of distributions is introduced, which is based on quotients of expected sample minima. The test is independent of the mean of the distribution, and, in applications to testing for exponentiality of data, compares favorably to other goodness-of-fit tests for exponentiality based on the empirical distribution function, regression methods and correlation statistics. The new minimal-moment method uses ratios of easily-calculated, unbiased, strongly consistent U-statistics, and the general technique can be used to test many standard composite null hypotheses such as exponentiality, normality or uniformity (as well as simple null hypotheses).

Modeling An Algebraic Stepper, John Clements, Mathew Flatt, Matthias Felleisen

Computer Science and Software Engineering

Programmers rely on the correctness of the tools in their programming environments. In the past, semanticists have studied the correctness of compilers and compiler analyses, which are the most important tools. In this paper, we make the case that other tools, such as debuggers and steppers, deserve semantic models, too, and that using these models can help in developing these tools. Our concrete starting point is the algebraic stepper in DrScheme, our Scheme programming environment. The algebraic stepper explains a Scheme computation in terms of an algebraic rewriting of the program text. A program is rewritten until it is in …

Interstate 69 And The Accessibility Of Indiana's Major Cities, Tracy Blankenship Markert

Morehead Electronic Journal of Applicable Mathematics Archives

No abstract provided.

Constructing A Large Number Of Nonisomorphic Graphs Of Order, P. O. De Wet

Morehead Electronic Journal of Applicable Mathematics Archives

No abstract provided.

Pressure Hallucinations And Patterns In The Brain, Eric Tkaczyk

Morehead Electronic Journal of Applicable Mathematics Archives

No abstract provided.

Comptel Observations Of The Blazars 3c 454.3 And Cta 102, S Zhang, W Collmar, V Schonfelder, H Bloemen, W Hermsen, Mark L. Mcconnell, K Bennett, O R. Williams

Space Science Center

We have analyzed the two blazars of 3C 454.3 and CTA 102 using all available COMPTEL data from 1991 to 1999. In the 10–30 MeV band, emission from the general direction of the sources is found at the 4σ-level, being consistent with contributions from both sources. Below 10 MeV only 3C 454.3 is significantly detected, with the strongest evidence (5.6 σ) in the 3–10 MeV band. Significant flux variability is not observed for both sources, while a low emission is seen most of the years in the 3–10 MeV light curve for 3C 454.3. Its time-averaged MeV spectrum suggests a …

Comptel Gamma-Ray Observations Of The C4 Solar Flare On 20 January 2000, C A. Young, M B. Arndt, K Bennett, A Connors, H Debrunner, R Diehl, Mark L. Mcconnell, R S. Miller, G Rank, James M. Ryan, V Schonfelder, C Winkler

Space Science Center

The “Pre-SMM” (Vestrand and Miller 1998) picture of gamma-ray line (GRL) flares was that they are relatively rare events. This picture was quickly put in question with the launch of the Solar Maximum Mission (SMM). Over 100 GRL flares were seen with sizes ranging from very large GOES class events (X12) down to moderately small events (M2). It was argued by some (Bai 1986) that this was still consistent with the idea that GRL events are rare. Others, however, argued the opposite (Vestrand 1988; Cliver, Crosby and Dennis 1994), stating that the lower end of this distribution was just a …

The Milagro Gamma-Ray Observatory, J E. Mcenery, R Atkins, W Benbow, D Berley, M L. Chen, D G. Coyne, B L. Dingus, D E. Dorfan, R W. Ellsworth, D Evans, A Falcone, L Fleysher, R Fleysher, G Gisler, J A. Goodman, T J. Haines, C M. Hoffman, S Hugenberger, L A. Kelley, I Leonor, Mark L. Mcconnell, J F. Mccullough, R S. Miller, A I. Mincer, M F. Morales, P Nemethy, James M. Ryan, B Shen, A Shoup, C Sinnis, A J. Smith, G W. Sullivan, O T. Tumer, K Wang, M O. Wascko, S Westerhoff, D A. Williams, G B. Yodh

Space Science Center

The Milagro water Cherenkov detector began full operation in January 2000. This detector is capable of monitoring the Northern sky at energies above 500 GeV for sources of equivalent strength to the Crab Nebula over one year of integration. We report on the current performance and sensitivity of Milagro.

Physiography And Late Quaternary-Holocene Processes Of Northeastern Gulf Of Mexico Outer Continental Shelf Off Mississippi And Alabama, James V. Gardner, Peter Dartnell, Kenneth J. Sulak, Brian R. Calder, Laurent Hellequin

Center for Coastal and Ocean Mapping

High-resolution multibeam mapping of the mid- and outer continental shelf and upper slope off Mississippi and Alabama reveals a complex bathymetry that reflects conditions during the last eustatic rise and the present high stand of sea level. The most prominent bathymetric features are pinnacles and hardgrounds that are scattered throughout the area. These features generally stand <10 m above the surrounding seafloor, cover large areas, and display a variety of morphologies. Almost all the reef pinnacles and hardgrounds have zones of high acoustic backscatter on their summits and on the seafloor immediately adjacent to their southwest walls. In addition, they also have erosional moats on the seafloor to the southwest. Large fields of bedforms are scattered throughout the mapped area. The asymmetries and orientations of the bedforms suggest that they were formed by excursions of the northeast-flowing Loop Current. In contrast, the pervasive ponding of sediment on the northeast sides of bathymetric highs indicates that one of the predominant directions of sediment transport has been to the south and southwest. The shelf break is a zone of numerous landslides of various sizes and complexities. The morphology of several landslide scars indicates that some of the failures occurred recently. One large reef-capped salt dome was mapped in the area, surrounded by a large field of pock-marks. Fields of pockmarks are also scattered on the shelf. The growth and demise of the reefs are related to the fluctuating transgression of eustatic sea level during the last deglaciation. Two episodes of reef drowning are correlated with the increased rates of sea-level rise during documented melt-water pulses; the first occurred from 14.8 to 14.2 ka and the second from 11.8 to 11.2 ka. Rates of sea-level rise exceeded the maximum growth rate of hermatypic corals only during these two intervals since the last glacial maximum and thus drowned the coral communities.

On The Estimation Of Errors In Gridded Bathymetric Compilations, Martin Jakobsson, Brian R. Calder, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

No abstract provided.

Combining Ordering Heuristics And Bundling Techniques For Solving Finite Constraint Satisfaction Problems, Amy Beckwith, Berthe Y. Choueiry

CSE Technical Reports

We investigate techniques to enhance the performance of backtrack search procedure with forward-checking (FC-BT) for finding all solutions to a finite Constraint Satisfaction Problem (CSP). We consider ordering heuristics for variables and/or values and bundling techniques based on the computation of interchangeability. While the former methods allow us to traverse the search space more effectively, the latter allow us to reduce it size. We design and compare strategies that combine static and dynamic versions of these two approaches. We show empirically the utility of dynamic variable ordering combined with dynamic bundling in both random problems and puzzles.