Entire DC Network | Open Access Articles | Digital Commons Network™

Ampnet - A Highly Available Cluster Interconnection Network, Amy Apon, Larry Bilbur

Publications

No abstract provided.

Book Review: Strange Matters: Undiscovered Ideas At The Frontiers Of Space And Time, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Strange Matters: Undiscovered Ideas at the Frontiers of Space and Time by Tom Siegfried. John Henry, 2002 307p, 0-309-08407-5 $24.95.

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Analysis Of The S.C. Accountability Act And No Child Left Behind, 2003, Barbara Stock Nielsen

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No abstract provided.

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Estimating Estuarine Pollutant Loading From Atmospheric Deposition Using Casco Bay, Maine As A Case Study, Casco Bay Air Deposition Study Team, Catherine Richardson, Douglas Saball, Andy Johnson, David Wright, Diane Gould, Alan Vanarsdale, Jeri Weiss, Beverly Bayley Smith, Ellen Doering

Publications

This paper provides a simple method for estimating the annual rate of direct atmospheric deposition of pollutants to an estuary when little or no local monitoring data is available. The approach we describe uses relevant regional data as well as literature values. The Casco Bay Estuary, located in the southwestern Maine, is used as a case study. The paper also includes the results of a field air deposition monitoring program conducted in Casco Bay (1998 - 2000) and favorably compares the estimates developed for rate of deposition of nitrogen, mercury and PAHs to the field monitoring results. The estimation approach …

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Chronic Wasting Disease In Deer And Elk: A Critique Of Current Models And Their Application, Eric M. Schauber, Alan Woolf

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Chronic wasting disease (CWD), a fatal transmissible spongiform encephalopathy of deer (Odocoileus spp.) and elk (Cervus elaphus), presents a challenge to wildlife managers because little is known about its transmission, yet it could severely threaten wildlife populations if action is not taken rapidly. Published mathematical models predict that CWD could devastate populations of free-living deer and elk, prompting wildlife managers to attempt large-scale eradication of deer in hopes of containing CWD outbreaks. Our objective is to critically examine the theoretical and empirical support for current models of CWD epizootiology, in light of herd health-management actions. We identify …

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Goldwasser, The Telecom Act, And Reflections On Antitrust Remedies, Philip J. Weiser

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No abstract provided.

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Intergalactic Globular Clusters, Michael J. West, Ted Von Hippel, Patrick Cote, Henry C. Ferguson, Michael D. Gregg, Andres Jordan, Ronald O. Marzke, Nial R. Tanvir

Publications

We confirm and extend our previous detection of a popula- tion of intergalactic globular clusters in Abell 1185, and report the first discovery of an intergalactic globular cluster in the nearby Virgo cluster of galaxies. The numbers, colors and luminosities of these objects can place constraints on their origin, which in turn may yield new insights to the evolution of galaxies in dense environments.

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Daubert Asks The Right Questions: Now Appellate Courts Should Help Find The Right Answers, Christopher B. Mueller

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No abstract provided.

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Modularity, Vertical Integration, And Open Access Policies: Towards A Convergence Of Antitrust And Regulation In The Internet Age, Joseph Farrell, Philip J. Weiser

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Antitrust law and telecommunications regulation have long adopted different stances on whether to mandate open access to information platforms. This article aims to help regulators and commentators incorporate both Chicago School and post-Chicago School arguments in evaluating this basic policy choice, suggesting how they can be integrated in an effective manner. In particular, the authors outline three alternative models that the FCC could adopt to guide its regulation of information platforms and facilitate a true convergence between antitrust and regulatory policy.

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Use Of Ground-Based Canopy Reflectance To Determine Radiation Capture, Nitrogen And Water Status, And Final Yield In Wheat, Glen L. Ritchie

Publications

Ground-based spectral imaging devices offer an important supplement to satellite imagery. Hand-held, ground-based sensors allow rapid, inexpensive measurements that are not affected by the earth’s atmosphere. They also provide a basis for high altitude spectral indices. We quantified the spectral reflectance characteristics of hard red spring wheat (Triticum aestivum cv. Westbred 936) in research plots subjected to either nitrogen or water stress in a two year study. Both types of stress reduced ground cover, which was evaluated by digital photography and compared with ten spectral reflectance indices. On plots with a similar soil background, simple indices such as the normalized …

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Measurement Of The Stochasticity Of Low-Latitude Geomagnetic Temporal Variations, Mark Anthony Reynolds, James A. Wanliss

Publications

Ground magnetometer measurements of total magnetic field strength from 6 stations at low latitudes were analyzed using power spectrum and Hurst range scaling techniques. The Hurst exponents for most of these time-series were near 0.5, which indicates stochasticity, with the highest latitude stations exhibiting some persistence with Hurst exponents greater than 0.6. Although no definite correlations are evident, the relative increase of the Hurst exponent with latitude suggests the possibility that the underlying dynamics of the magnetosphere change with latitude. This result may help quantify the dynamics of the inner magnetosphere itself without the direct presence of the solar wind …

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The Local-Time Variation Of The Quiet Plasmasphere: Geosynchronous Observations And Kinetic Theory, Mark Anthony Reynolds, G. Ganguli, Y-J Su, M.F. Thomsen

Publications

The quiet-time structure of the plasmaspheric density was investigated using observations of the Los Alamos geosynchronous satellites, and these observations were compared with theoretical predictions of the quasi-static localtime variation by a kinetic model. It was found that the coupling to the ionosphere (via the local-time variation of the exobase) played a key role in determining the density structure at 6.6 RE. The kinetic model predicts that most of the local-time variation at geosynchronous orbit is due to the variation of the exobase parameters. During quiet times, when the convection electric field is dominated by the corotation field, the effects …

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A Simulation Study Of Space-Based Observations Of Gravity Waves In The Airglow Using Observed Aloha-93 Wave Parameters, Michael P. Hickey Ph.D., J. S. Brown

Publications

We use gravity wave parameters derived from the ALOHA-93 campaign to model four gravity waves in airglow emissions as observed from the ground to numerically predict whether these waves could have been observed from space. In spite of encountering critical levels, some waves may still be observed in the airglow provided the critical level lies within the airglow emission region. One of the four waves experiences a critical level in the lower region of an airglow layer such that the disturbance to the volume emission rate would be effectively limited to a short distance along a satellite line of sight. …

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An Observation Of A Fast External Atmospheric Acoustic-Gravity Wave, J. H. Hecht, R. L. Walterscheid, Michael P. Hickey Ph.D., R. J. Rudy, A. Z. Liu

Publications

In November 1999 a new near-IR airglow imaging system was deployed at the Starfire Optical Range outside of Albuquerque, New Mexico. This system allowed wide angle images of the airglow to be collected, with high signal to noise, every 3 seconds with a one second integration time. At approximately 1000 UT on November 17, 1999, a fast wavelike disturbance was seen propagating through the OH Meinel airglow layer. This wave had an observed period of ≈215 seconds, an observed phase velocity of ≈160 m/s and a horizontal wavelength of ≈35 km. This phase velocity is among the fastest yet reported …

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Further Investigations Of A Mesospheric Inversion Layer Observed In The Aloha-93 Campaign, Tai-Yin Huang, Michael P. Hickey Ph.D., Tai-Fu Tuan

Publications

Temperature and wind data obtained from a Na wind/temperature lidar operated by the University of Illinois group during the Airborne Lidar and Observations of the Hawaiian Airglow (ALOHA-93) Campaign, previously analyzed by Huang et al. [1998] using an isothermal Brunt-Va¨isa¨la¨ frequency, have been reexamined to include temperature gradients in the calculation of the Richardson number. In the previous analysis using the isothermal Brunt-Va¨isa¨la¨ frequency the existence of convective instability could not be assessed. New analysis shows that the nonisothermal Richardson number preserves some features found previously, with some striking differences noticable at times between 0900 and 1030 UT. The nonisothermal …

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Coupling Of Coamps And Wavetech With Improved Wave Physics, Shahrdad Sajjadi, Pat Fitzpatrick, Gueorgui Mostovoi, Yongzuo Li, Matt Bettencourt

Publications

The Model Coupling Executable Library (MCEL), developed at the University of Southern Mississippi's Center of Higher Learning, has been successfully used to couple the Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) and the ocean wave model WAVEWATCH. An example of its application is shown for Hurricane Gordon, showing that two-way coupling results affects boundary layer physics differently than one-way coupling --- in this case, resulting in larger o z and, consequently, larger surface fluxes and a more intense hurricane. However, since analyzing MCEL is difficult because the wave physics is inaccurate, improvements to the wave algorithms are also part of the …

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Search For Oxygen In Cool Dq White Dwarf Atmospheres, M. Kilic, Ted Von Hippel, D. E. Winget, D. F. Lester, D. Saumon

Publications

The existence of carbon in cool He white dwarf (WD) atmospheres has been known for a relatively long time[5]. The presence of carbon in these atmospheres is explained by convective dredge up of interior carbon [6]. Pelletier et al. (1986) presented the first detailed calculations of this process and showed that carbon diffuses upwards from the core into the base of the He-rich envelope where it can be dredged up by a surface convection zone. As the temperature of the star decreases, more carbon diffuses upward, and the base of convection zone moves deeper into the star, further enriching the …

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Identification Of Cool White Dwarfs In The Noao Deep Wide-Field Survey, M. Kilic, Don E. Winget, T. Von Hippel, C.F. Claver

Publications

The chronology of star formation is recorded in the white dwarf luminosity function (WDLF). White dwarf (WD) structure implies a relatively simple connection between WD luminosity and age. First attempts to exploit WDs as chronometers [3,4,6] showed that the WDLF was a map of the history of star formation in the disk, and a significant shortfall of low-luminosity degenerates–the inevitable consequence of the finite age of the disk. The shortfall near log(L/L⊙)≈−4.5 implies a disk age of 6.5–9.5 Gyr [2]. The WDLF from wide common proper motion binaries [5] does not show the shortfall seen by Liebert et al. (1988). …

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Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BVI observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5 m telescope under excellent seeing conditions. These observations probe to V > 26 and display the lower main sequence in BV and VI CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the location …

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Book Review: Neptune: The Planet, Rings And Satellites, T. D. Oswalt

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This document is Dr. Oswalt’s review of Neptune : the Planet, Rings and Satellites by Ellis D. Miner and Randii R. Wessen Springer/Praxis, 2002 297p, 1-85233-216-6 $44.95

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Automated Stellar Spectral Classification And Parameterization For The Masses, Ted Von Hippel, Carlos Allende Prieto, Chris Sneden

Publications

Stellar spectroscopic classification has been successfully automated by a number of groups. Automated classification and parameterization work best when applied to a homogeneous data set, and thus these techniques primarily have been developed for and applied to large surveys. While most ongoing large spectroscopic surveys target extragalactic objects, many stellar spectra have been and will be obtained. We briefly summarize past work on automated classification and parameterization, with emphasis on the work done in our group. Accurate automated classification in the spectral type domain and parameterization in the temperature domain have been relatively easy. Automated parameterization in the metallicity domain, …

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Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel

Publications

We report medium-resolution (1–2A ˚ ) spectroscopy and broadband (UBV) photometry for a sample of 39 bright stars (the majority of which are likely to be giants) selected as metal-deficient candidates from an objective-prism survey concentrating on Galactic latitudes below |b| = 30, the Luminous Stars Extension (LSE) survey of Drilling & Bergeron. Although the primary purpose of the LSE survey was to select OB stars (hence the concentration on low latitudes), the small number of bright metal-deficient giant candidates noted during this survey provide interesting information on the metal-weak thick disk (MWTD) population. Metal abundance estimates are obtained from …

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Uaa Student Showcase Journal: Recognizing Excellence (2002), N/A N/A

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No abstract provided.

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Modeling The Effects Of Reservoir Competence Decay And Demographic Turnover In Lyme Disease Ecology, Eric M. Schauber, Richard S. Ostfeld

Publications

Lyme disease risk is related to the abundance of infected nymphal ticks, which in turn depends on the abundance and reservoir competence of wild hosts. Reservoir competence of a host (i.e., probability that an infected host will infect a feeding vector) often declines over time after inoculation, and small mammalian reservoirs typically undergo rapid population growth during the period when vector ticks feed. These processes can affect disease risk in the context of site-specific tick abundance and host community composition. We modeled the effects of reservoir decay and host demographic turnover on Lyme disease risk using a simple yearly difference …

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Wiyn Open Cluster Study Xi: Wiyn1 3.5m Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BV I observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5m telescope under excellent seeing conditions. These observations probe to V > 26, and display the lower main sequence in BV and V I CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the …

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Book Review: The Observing Guide To The Messier Marathon: A Handbook And Atlas, T. D. Oswalt

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This document is Dr. Oswalt’s review of The Observing Guide to the Messier Marathon : a Handbook and Atlas by Don Machholz. Cambridge, 2002 157p, 0-521-80386-1 $25.00.

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Book Review: Flash!: The Hunt For The Biggest Explosions In The Universe, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Flash! : the hunt for the biggest explosions in the universe by Govert Schilling. tr. by Naomi Greenberg-Slovin Cambridge, 2002 291p, 0-521-80053-6 $28.00

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One-Gas Models With Height-Dependent Mean Molecular Weight: Effects On Gravity Wave Propagation, R. L. Walterscheid, Michael P. Hickey Ph.D.

Publications

Many models of the thermosphere employ the one-gas approximation where the governing equations apply only to the total gas and the physical properties of the gas that depend on composition (mean molecular weight and specific heats) are height-dependent. It is further assumed that the physical properties of the gas are locally constant; thus motion-induced perturbations are nil. However, motion in a diffusively separated atmosphere perturbs local values of mean molecular weight and specific heats. These motion-induced changes are opposed by mutual diffusion of the constituent gases, which attempts to restore diffusive equilibrium. Assuming that composition is locally constant is equivalent …

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Reflection Of A Long-Period Gravity Wave Observed In The Nightglow Over Arecibo On May 8–9, 1989?, Michael P. Hickey Ph.D.

Publications

During the Arecibo Initiative for Dynamics of the Atmosphere (AIDA) campaign in 1989 a characteristic of gravity wave perturbations observed in mesopause region airglow emissions was that airglow brightness fluctuations and airglow-derived temperature fluctuations often occurred either in phase or in antiphase. This stimulated the development of a theory suggesting that such in-phase fluctuations were most probably the result of strong reflections occurring in the mesosphere and lower thermosphere region. Recent examination of a particular wave event and application of simple WKB-type theory has appeared to support this hypothesis. Here we use a full-wave model and a WKB-type model, each …

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Three-Dimensional Spectral Classification Of Low-Metallicity Stars Using Artificial Neural Networks, Shawn Snider, Ted Von Hippel, Et Al.

Publications

We explore the application of artificial neural networks (ANNs) for the estimation of atmospheric parameters (T_eff, log g, and [Fe/H]) for Galactic F- and G-type stars. The ANNs are fed with medium-resolution (Δλ ~ 1-2 Å) non-flux-calibrated spectroscopic observations. From a sample of 279 stars with previous high-resolution determinations of metallicity and a set of (external) estimates of temperature and surface gravity, our ANNs are able to predict T_eff with an accuracy of σ(T_eff) = 135-150 K over the range 4250 ≤ T_eff ≤ 6500 K, log g with an accuracy …

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Full-Text Articles in Entire DC Network

Ampnet - A Highly Available Cluster Interconnection Network, Amy Apon, Larry Bilbur

Publications

Book Review: Strange Matters: Undiscovered Ideas At The Frontiers Of Space And Time, T. D. Oswalt

Publications

Analysis Of The S.C. Accountability Act And No Child Left Behind, 2003, Barbara Stock Nielsen

Publications

Estimating Estuarine Pollutant Loading From Atmospheric Deposition Using Casco Bay, Maine As A Case Study, Casco Bay Air Deposition Study Team, Catherine Richardson, Douglas Saball, Andy Johnson, David Wright, Diane Gould, Alan Vanarsdale, Jeri Weiss, Beverly Bayley Smith, Ellen Doering

Publications

Chronic Wasting Disease In Deer And Elk: A Critique Of Current Models And Their Application, Eric M. Schauber, Alan Woolf

Publications

Goldwasser, The Telecom Act, And Reflections On Antitrust Remedies, Philip J. Weiser

Publications

Intergalactic Globular Clusters, Michael J. West, Ted Von Hippel, Patrick Cote, Henry C. Ferguson, Michael D. Gregg, Andres Jordan, Ronald O. Marzke, Nial R. Tanvir

Publications

Daubert Asks The Right Questions: Now Appellate Courts Should Help Find The Right Answers, Christopher B. Mueller

Publications

Modularity, Vertical Integration, And Open Access Policies: Towards A Convergence Of Antitrust And Regulation In The Internet Age, Joseph Farrell, Philip J. Weiser

Publications

Use Of Ground-Based Canopy Reflectance To Determine Radiation Capture, Nitrogen And Water Status, And Final Yield In Wheat, Glen L. Ritchie

Publications

Measurement Of The Stochasticity Of Low-Latitude Geomagnetic Temporal Variations, Mark Anthony Reynolds, James A. Wanliss

Publications

The Local-Time Variation Of The Quiet Plasmasphere: Geosynchronous Observations And Kinetic Theory, Mark Anthony Reynolds, G. Ganguli, Y-J Su, M.F. Thomsen

Publications

A Simulation Study Of Space-Based Observations Of Gravity Waves In The Airglow Using Observed Aloha-93 Wave Parameters, Michael P. Hickey Ph.D., J. S. Brown

Publications

An Observation Of A Fast External Atmospheric Acoustic-Gravity Wave, J. H. Hecht, R. L. Walterscheid, Michael P. Hickey Ph.D., R. J. Rudy, A. Z. Liu

Publications

Further Investigations Of A Mesospheric Inversion Layer Observed In The Aloha-93 Campaign, Tai-Yin Huang, Michael P. Hickey Ph.D., Tai-Fu Tuan

Publications

Coupling Of Coamps And Wavetech With Improved Wave Physics, Shahrdad Sajjadi, Pat Fitzpatrick, Gueorgui Mostovoi, Yongzuo Li, Matt Bettencourt

Publications

Search For Oxygen In Cool Dq White Dwarf Atmospheres, M. Kilic, Ted Von Hippel, D. E. Winget, D. F. Lester, D. Saumon

Publications

Identification Of Cool White Dwarfs In The Noao Deep Wide-Field Survey, M. Kilic, Don E. Winget, T. Von Hippel, C.F. Claver

Publications

Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

Book Review: Neptune: The Planet, Rings And Satellites, T. D. Oswalt

Publications

Automated Stellar Spectral Classification And Parameterization For The Masses, Ted Von Hippel, Carlos Allende Prieto, Chris Sneden

Publications

Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel

Publications

Uaa Student Showcase Journal: Recognizing Excellence (2002), N/A N/A

Publications

Modeling The Effects Of Reservoir Competence Decay And Demographic Turnover In Lyme Disease Ecology, Eric M. Schauber, Richard S. Ostfeld

Publications

Wiyn Open Cluster Study Xi: Wiyn1 3.5m Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

Book Review: The Observing Guide To The Messier Marathon: A Handbook And Atlas, T. D. Oswalt

Publications

Book Review: Flash!: The Hunt For The Biggest Explosions In The Universe, T. D. Oswalt

Publications

One-Gas Models With Height-Dependent Mean Molecular Weight: Effects On Gravity Wave Propagation, R. L. Walterscheid, Michael P. Hickey Ph.D.

Publications

Reflection Of A Long-Period Gravity Wave Observed In The Nightglow Over Arecibo On May 8–9, 1989?, Michael P. Hickey Ph.D.

Publications

Three-Dimensional Spectral Classification Of Low-Metallicity Stars Using Artificial Neural Networks, Shawn Snider, Ted Von Hippel, Et Al.

Publications