Digital Commons Network^™

Measuring The Evolution Of The Most Stable Optical Clock G 117-B15a, S. O. Kepler, Ted Von Hippel, Et Al.

Publications

We report our measurement of the rate of change of period with time () for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have finally obtained a 4 σ measurement observed = (4.27 ± 0.80) × 10-15 s s-1. Taking into account the proper-motion effect of proper = (7.0 ± 2.0) × 10-16s s-1, we obtain a rate of change of period with time of = (3.57 ± 0.82) × 10-15 s s-1. This value is consistent with the cooling rate in our white dwarf …

Resource-Based View Of Knowledge Management For Competitive Advantage, Leila A. Halawi, Jay E. Aronson, Richard V. Mccarthy

Publications

We are not only in a new millennium, but also in a new era: the knowledge era. Sustainable competitive advantage is dependent on building and exploiting core competencies. The resource-based view (RBV) of the firm defines a strategic asset as one that is rare, valuable, imperfectly imitiable and non-substitutable. Knowledge is seen as a strategic asset with the potential to be a source of competitive advantage for an organization. In this paper, we provide a model that examines how and why knowledge management (KM) can be sued to create competitive advantage from the RBV of the firm.

Faint Blue Objects In The Hubble Deep Field–South Revealed: White Dwarfs, Subdwarfs, And Quasars, Mukremin Kilic, Ted Von Hippel, Et Al.

Publications

We explore the nature of the faint blue objects in the Hubble Deep Field–South. We have derived proper motions for the point sources in the Hubble Deep Field–South using a 3 yr baseline. Combining our proper-motion measurements with spectral energy distribution fitting enabled us to identify four quasars and 42 stars, including three white dwarf candidates. Two of these white dwarf candidates, HDF-S 1444 and 895, are found to display significant proper motion, 21:1±7:9 and 34:9 ± 8:0 mas yr ^-1, and are consistent with being thick-disk or halo white dwarfs located at ̴2 kpc. The other faint …

Poverty And The Cost Of Living: Income Issues Associated With South Carolina's Self Support Reserve For Noncustodial Parents, 2005 November 15, Ellen Weeks Saltzman, Ada Louise Steirer

Publications

No abstract provided.

Keck Hires Spectroscopy Of Four Candidate Solar Twins, Jeremy R. King, Ann M. Boesgaard, Simon C. Schuler

Publications

We use high signal-to-noise ratio, high-resolution Keck HIRES spectroscopy of four solar twin candidates (HIP 71813, 76114, 77718, and 78399) pulled from our Hipparcos-based Ca ii H and K survey to carry out parameter and abundance analyses of these objects. Our spectroscopic Teff estimates are $100 K hotter than the photometric scale of the recent Geneva-Copenhagen survey; several lines of evidence suggest the photometric temperatures are too cool at solar Teff. At the same time, our abundances for the three solar twin candidates included in the Geneva-Copenhagen survey are in outstanding agreement with the photometric metallicities; there is no sign …

Growth, Fecundity, And Diets Of Newly Established Silver Carp In The Middle Mississippi River, Christopher J. Williamson, James E. Garvey

Publications

The silver carp Hypophthalmichthys molitrix has spread throughout the Mississippi River drainage. During 2003, we determined its population status and potential impact in the middle Mississippi River (MMR), the conduit between the lower Mississippi River and the upper Mississippi, Missouri, and Illinois rivers. We quantified growth, age structure, fecundity, and diets of silver carp sampled with trammel nets and AC electrofishing in main-channel areas. Mean length at age in the MMR exceeded that of populations in Asia by as much as 26%. Individuals were typically more than 1 year old and 230 mm total length, suggesting that small, young fish …

Determining Which Delivery Styles Are Best Suited For Instructing In The Distance Learning Environment, James T. Schultz, Marian C. Schultz, Thomas G. Henkel

Publications

The purpose of this study was to ascertain if there is a specific style of teaching which is better suited for the distance learning (virtual) environment, as opposed to the traditional classroom environment. Numerous studies have shown that individuals have different delivery styles in the classroom. The study utilized instructor delivery styles and faculty perceptions of distance learning programs to develop an instrument which identifies the style that would be more successful in the distance learning environment. The study employed an author developed instrument, which included a derivative of the Kolb Learning Style Inventory (LSI) instrument, to determine the teaching …

Hyades Oxygen Abundances From The K6300 [O I] Line: The Giant-Dwarf Oxygen Descrepancy Revisited, Jeremy R. King, Simon C. Schuler, Artie P. Hatzes, Martin Kϋrster, Lih-Sin The

Publications

We present the results of our abundance analysis of Fe, Ni, and O in high signal-to-noise ratio, high-resolution Very Large Telescope UVES and McDonald 2dcoude´ spectra of nine dwarfs and three giants in the Hyades open cluster. The difference in Fe abundances derived from Fe ii and Fe i lines ([Fe ii/HÀ½Fe i/H)and Ni i abundances derived from moderately high-excitation ( %4:20 eV) lines is found to increase with decreasing Teff for the dwarfs. Both of these findings are in concordance with previous results of overexcitation/overionization in cool young dwarfs. Oxygen abundances are derived from the [O i] k6300 line, …

High Resolution Spectroscopy Of The Planetary Host Hd 13189: Highly Evolved And Metal-Poor, Simon C. Schuler, James H. Kim, Michael C. Tinker, Jeremy R. King, Artie P. Hatzes, Eike W. Guenther

Publications

We report on the abundances of 13 elements in the planetary host HD 13189, a massive giant star. Abundances are found to be subsolar, with [Fe/H] = -0.58 ± 0.04; HD 13189 is one of the most metal-poor planetary hosts yet discovered. Abundance ratios relative to Fe show no peculiarities with respect to random field stars. A census of metallicities of the seven currently known planet-harboring giants results in a distribution that is more metal-poor than the well-known metal-rich distribution of main-sequence (MS) planetary hosts. This finding is discussed in terms of accretion of H-depleted material, one of the possible …

Acoustic Waves Generated By Gusty Flow Over Hilly Terrain, R. L. Walterscheid, Michael P. Hickey Ph.D.

Publications

We examine the generation of acoustic waves by gusty flow over hilly terrain. We use simple theoretical models of the interaction between terrain and eddies and a linear model of acoustic-gravity wave propagation. The calculations presented here suggest that over a dense array of geographically extensive sources orographically generated vertically propagating acoustic waves can be a significant cause of thermospheric heating. This heating may account in good part for the thermospheric hot spot near the Andes reported by Meriwether et al. (1996, 1997).

Excess Infrared Radiation From The Massive Daz White Dwarf Gd 362: A Debris Disk?, Mukremin Kilic, Ted Von Hippel, Et Al.

Publications

We report the discovery of excess K-band radiation from the massive DAZ white dwarf star GD 362. Combining infrared photometric and spectroscopic observations, we show that the excess radiation cannot be explained by a stellar or substellar companion, and is likely to be caused by a debris disk. This would be only the second such system known, discovered 18 years after G29-38, the only single white dwarf currently known to be orbited by circumstellar dust. Both of these systems favor a model with accretion from a surrounding debris disk to explain the metal abundances observed in DAZ white dwarfs. …

Deep Photometry Of The Globular Cluster M5: Distance Estimates From White Dwarf And Main-Sequence Stars, Andrew C. Layden, Ted Von Hippel, Et Al.

Publications

We present deep VI photometry of stars in the globular cluster M5 (NGC 5904) based on images taken with the Hubble Space Telescope. The resulting color-magnitude diagram reaches below V ≈27 mag, revealing the upper 2–3 mag of the white dwarf cooling sequence and main-sequence stars 8 mag and more below the turnoff. We fit the main sequence to subdwarfs of known parallax to obtain a true distance modulus of (m ̶ M )₀ = 14:45 ± 0:11 mag. A second distance estimate based on fitting the cluster white dwarf sequence to field white dwarfs with known parallax …

Use Of Track Plates To Quantify Predation Risk At Small Spatial Scales, Matthew J. Connors, Eric M. Schauber, Andrew Forbes, Clive G. Jones, Brett J. Goodwin, Richard S. Ostfeld

Publications

Spatial heterogeneity in risk is a critical component of predator-prey interactions. However, at small spatial scales, it is difficult to quantify predation risk without altering it. We used track plates to measure local predation risk created by white-footed mouse (Peromyscus leucopus) foraging activity on oak-forest plots in Millbrook, New York. Live gypsy moth pupae (Lymantria dispar) were placed at 2 heights on trees and monitored for predation. Pupae deployed on trees visited by mice were more likely to be eaten than those on trees not visited. Logistic regression indicated that predation rates on gypsy moth pupae were …

Interstate Water Compacts: A Bibliography, George William Sherk

Publications

Utton Center Model Interstate Water Compact Project. Arranged alphabetically (years and then by letter).

Chemical Composition In The Globular Cluster M71 From Keck Hires Spectra Of Turnoff Stars, Ann Merchant Boesgaard, Jeremy R. King, Ann Marie Cody, Alex Stephens, Constantine P. Deliyannis

Publications

We have made observations with the Keck I telescope and HIRES at a resolution of ∼45,000 of five nearly identical stars at the turn-off of the metal-rich globular cluster M 71. Our mean Fe abundance, [Fe/H]=-0.80 +-0.02, is in excellent agreement with previous cluster determinations from both giants and near-turnoff stars. There is no clear evidence for any star-to-star abundance differences or correlations in our sample. Abundance ratios of the Fe-peak elements (Cr, Ni) are similar to Fe. The turn-off stars in M71 have remarkably consistent enhancements of 0.2 - 0.3 dex in [Si/Fe], [Ca/Fe] and [Ti/Fe] -- like the …

Electronic Transport Imaging In A Multiwire Sno2 Chemical Field-Effect Transistor Device, Sergei V. Kalinin, J. Shin, S. Jesse, D. Geohegan, A. P. Baddorf, Y. Lilach, M. Moskovits, A. Kolmakov

Publications

The electronic transport and the sensing performance of an individual SnO₂ crossed-nanowires device in a three-terminal field-effect transistor configuration were investigated using a combination of macroscopic transport measurements and scanning surface-potential microscopy (SSPM). The structure of the device was determined using both scanning electron- and atomic force microscopy data. The SSPM images of two crossed one-dimensional nanostructures, simulating a prototypical nanowire network sensors, exhibit large dc potential drops at the crossed-wire junction and at the contacts, identifying them as the primary electroactive elements in the circuit. The gas sensitivity of this device was comparable to those of sensors formed …

Species Frequency Dynamics In An Old-Field Succession: Effects Of Disturbance, Fertilization And Scale, David J. Gibson, Beth A. Middleton, Kari Foster, Yohanes A.K. Honu, Erik W. Hoyer, Marilyn Mathis

Publications

Question: Can patterns of species frequency in an old-field be explained within the context of a metapopulation model? Are the patterns observed related to time, spatial scale, disturbance, and nutrient availability?

Location: Upland and lowland old-fields in Illinois, USA.

Method: Species richness was recorded annually for seven years following plowing of an upland and lowland old-field subject to crossed fertilizer and disturbance treatments (mowing and rototilling). Species occupancy distributions were assessed with respect to the numbers of core and satellite species.

Results: In both fields, species richness became higher in disturbed plots than in undisturbed plots over time, and decreased …

Beryllium Enhancement As Evidence For Accretion In A Lithium-Rich F Dwarf, Johanna F. Ashwell, R D. Jeffries, Barry Smalley, C P. Deliyannis, Aaron Steinhauer, Jeremy R. King

Publications

The early F dwarf star ``J37'' in the open cluster NGC6633 shows an unusual pattern of photospheric abundances, including an order of magnitude enhancement of lithium and iron-peak elements, but an under-abundance of carbon. As a consequence of its thin convection zone these anomalies have been attributed to either radiative diffusion or the accretion of hydrogen-depleted material. By comparing high resolution VLT/UVES spectra of J37 (and other F stars in NGC 6633) with syntheses of the Be ii doublet region at 3131 Ang, we establish that J37 also has a Be abundance (A(Be)=3.0+/-0.5) that is at least ten times the …

Design Of A Flexible And Agile Centering Preprocessing System, Laine Mears, Thomas Kurfess

Publications

Precise machining of bearing rings is integral to finished bearing assembly quality. The output accuracy of center-based machining systems such as lathes and magnetic chuck grinders relates directly to the accuracy of part centering before machining. Traditional tooling for centering on such machines is subject to wear, dimensional inaccuracy, setup time (hard tooling) and human error (manual centering). A flexible system for initial part centering is proposed based on a single measurement system and actuator. In this system, the part is placed by hand onto the machine table, automatically rotated and measured to identify center of geometry offset from center …

International Non-Proliferation Policy And The United Nations Security System After 9/11 And Iraq, Alexander Siedschlag

Publications

No matter if the "weapons of mass destruction" (WMD) argument brought forward by the U.S. in respect of the multinational military intervention in Iraq in 2003 was meant to be "real" or rather was "constructed": It is a fact that the WMD case, along with the new concept of security after 9/11, is real in its consequences for international WMD non-proliferation policy, collective use of force, and thus the U.N. security system. However, this fact does not cut off the path-dependencies of a policy of containment of nuclear, biological and chemical weapons. A point often overlooked is that not only …

Co Line Emission And Absorption From The Hl Tauri Disk-Where Is All The Dust?, Sean D. Brittain, Terrence W. Rettig, Theodore Simon, Craig Kulesa

Publications

We present high-resolution infrared spectra of HL Tau, a heavily embedded young star. The spectra exhibit broad emission lines of 12CO gas-phase molecules, as well as narrow absorption lines of 12CO, 13CO, and C18O. The broad emission lines of vibrationally excited 12CO are dominated by the hot (T ~ 1500 K) inner disk. The narrow absorption lines of CO are found to originate from the circumstellar gas at a temperature of ~100 K. The 12CO column density for this cooler material [(7.5 ± 0.2) × 1018 cm-2] indicates a large column of absorbing gas along the line of sight. In …

Co Emission And Absorption Toward V1647 Orionis (Mcneil's Nebula), Terrence W. Rettig, Sean D. Brittain, Erika Gibb, Theodore Simon, Craig Kulesa

Publications

We present high-resolution infrared spectra of V1647 Ori, the illuminating star of McNeil's Nebula, which reveal the presence of hot and cold gas-phase CO and ices of CO and H2O. The emission lines of 12CO (10), (21), and (32) likely originate from 2500 K gas in an inner accretion disk region, where substantial clearing of dust has occurred. The width of the emission lines increases with increasing J-value, suggesting that the hottest CO gas we detect is located closest to the central star. The narrower widths of the low-J CO emission lines are indicative of more distant, cooler material in …

Digital Democracy And Its Application To The International Arena – From “Deliberation” To “Decision”, Alexander Siedschlag

Publications

Apart from the discussion about computer-mediated change in community and domestic political affairs, there is a pending debate on general effects of internet- or “net”-based communication on international politics. The reference to international politics rather than international relations is a consciously chosen one – for this paper focuses on net effects on collective decision-making rather than international-society processes. IP/IR driven research on internet-induced political change does not very much link itself to the state of knowledge in internet-and-politics research. Rather, it commonly departs from sub-discipline specific concepts such as neorealist power analysis or post-international turbulence analysis (cf. Allison 2002).

Element-Specific Magnetic Properties Of Co2mnsi Thin Films, S. Stadler, D. H. Minott, D. Harley, J. P. Craig, M. Khan, I. I. Dubenko, N. Ali, K. Story, J. Dvorak, Y. U. Idzerda, D. A. Arena, V. G. Harris

Publications

Co₂MnSi thin films were grown on Al₂O₃ (a plane) and GaAs (001) substrates and on thin silicon nitride windows using pulsed laser deposition. Angle-dependent magneto-optic Kerr effect measurements reveal both a uniaxial and a fourfold magnetocrystalline anisotropy for films grown on GaAs (001). X-ray magnetic circular dichroism spectra were measured at the L_2,3 edges of the thin films as a function of aluminum cap layer thickness, and transmission mode L_2,3 x-ray absorption through a 1000-Å Co₂MnSi film grown on a silicon nitride membrane were measured, indicating that deviations from metalliclike …

The Structural And Magnetic Properties Of Ni2mn1−Xmxga (M = Co, Cu), Mahmud Khan, Igor Dubenko, Shane Stadler, Naushad Ali

Publications

In Ni₂MnGa (cubic structure of L2₁ type) a first order martensitic structural transition, from the parent cubic (austenitic) phase to a low temperature complex tetragonal structure, takes place at T_M = 202 K, and ferromagnetic order in the austenitic phase sets at T_C = 376 K. In this work, the Mn sites in Ni₂MnGa have been partially substituted with magnetic Co and nonmagnetic Cu, and the influence of these substitutions on the structural and magnetic properties of Ni₂Mn_1−xM_xGa (M = Co and Cu) have been studied …

Where Are The Magnetic White Dwarfs With Detached, Nondegenerate Companions?, James W. Liebert, Dayal T. Wickramsinghe, Gary D. Schmidt, Nicole M. Silvestri, T. D. Oswalt, Et Al.

Publications

The Sloan Digital Sky Survey has already more than doubled the sample of white dwarfs with spectral classifications, the subset with detached M dwarf companions, and the subset of magnetic white dwarfs. In the course of assessing these new discoveries, we have noticed a curious, unexpected property of the total lists of magnetic white dwarfs and of white dwarf plus main-sequence binaries: there appears to be virtually zero overlap between the two samples! No confirmed magnetic white dwarf has yet been found in such a pairing with a main-sequence star. The same statement can be made for the samples of …

We Need To Talk....About Institutional Integrity, Daniel E. Wueste

Publications

It seems a reasonable hypothesis that institutional health depends upon institutional integrity and institutional integrity depends upon individual integrity. If that’s right, “disease” may be manifest at two levels—at the level of institutional or individual integrity.

I begin with the first part of the hypothesis above, that institutional integrity is a condition of institutional health. The legal theorist Lon Fuller articulated this idea in a less generalized form when he spoke of a morality internal to law that makes law possible. I will explain and illustrate this idea and indicate how it applies to institutions of various sorts, including professions …

Uaa Student Showcase Journal: Recognizing Excellence (2005), N/A N/A

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No abstract provided.

Physical Processes In Acoustic Wave Heating Of The Thermosphere, G. Schubert, Michael P. Hickey Ph.D., R. L. Walterscheid

Publications

Upward propagating acoustic waves heat the atmosphere at essentially all heights due to effects of viscous dissipation, sensible heat flux divergence, and Eulerian drift work. Acoustic wave-induced pressure gradient work provides a cooling effect at all heights, but this is overwhelmed by the heating processes. Eulerian drift work and wave-induced pressure gradient work dominate the energy balance, but they nearly cancel at most altitudes, leaving their difference, together with viscous dissipation and sensible heat flux divergence to heat the atmosphere. Acoustic waves are very different from gravity waves which cool the upper atmosphere through the effect of sensible heat flux …

A New Species Of Ceraclea (Trichopterma:Leptoceridae) Preying On Snails, John C. Morse, David R. Lenat

Publications

Ceraclea joannae, new species, feeds on the freshwater snail Somatogyrus virginicus Walker (Hydrobiidae). Our study is the first report of prey other than sponges for a Ceraclea species and the first report of snail predation by Trichoptera larvae in North America. Ceraclea joannae larvae and adults resemble those of C. diluta (Hagen); however, the larva of the new species has a dark head, sickle-shaped mandibles, and a dark pronotum except for a pair of unique, conspicuous, oblique, white bands; the male differs in the slightly longer superior appendages, more nearly straight ventral margins of tergum X, slightly stouter inferior …