Physical Sciences and Mathematics Commons^™

Observational Evidence Of Wave Ducting And Evanescence In The Mesosphere, J. R. Isler, Michael J. Taylor, D. C. Fritts

All Physics Faculty Publications

A collaborative radar and imaging study of gravity waves over the Hawaiian Islands was performed during October 1993 as part of the Airborne Lidar and Observations of Hawaiian Airglow 1993/Coupling and Dynamics of Regions Equatorial (ALOHA-93/CADRE) campaign to investigate the propagation characteristics of short-period (<1 hour) waves at nightglow altitudes. The horizontal wavelengths and apparent phase speeds of quasi-monochromatic wave events were measured in four separate nightglow emissions using data obtained by a high-resolution CCD imager. This information was correlated with simultaneous MF radar wind measurements over the same height interval (∼80–100 km) to infer intrinsic wave parameters in each case. Correlating the two data sets allowed the determination of the local vertical wavenumber for each event, in particular whether it be real (indicative of freely propagating waves) or imaginary (indicative of ducted or evanescent waves). The results of this study indicate a preponderance of ducted or evanescent waves at 80–100 km during the time of the observations, with up to ∼75% of the events recorded exhibiting ducted or evanescent behavior. Also noted was a tendency for ducted behavior to be more prevalent among waves with shorter horizontal wavelengths, in agreement with Doppler ducting theory. These results suggest that ducted waves are relatively common in the upper mesosphere and lower thermosphere region, at least over the mid-Pacific Ocean. As small-scale waves which are ducted have the potential to travel much longer horizontal distances than freely propagating waves, the frequency of their occurrence should be taken into account in efforts to quantify gravity wave effects at these altitudes.

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

Hands-On Phasors And Multiple-Slit Interference, Rand S. Worland, Matthew J. Moelter

Physics

No abstract provided.

A Tribute To Karl Menger, Seymour Kass

Humanistic Mathematics Network Journal

No abstract provided.

Book Review: Garbage Pizza, Patchwork Quilts, And Math Magic: Stories About Teachers Who Love To Teach And Children Who Love To Learn, By Susan Ohanian, Alvin White

Humanistic Mathematics Network Journal

No abstract provided.

Reflections Of Glenmount Reform Effort, Gail Black, Ruth Miller

Humanistic Mathematics Network Journal

No abstract provided.

Resource Review: Research On Children's Learning As A Tool To Improve Math And Science Teaching, Cynthia Hudley

Humanistic Mathematics Network Journal

No abstract provided.

Helping Students With Attention Deficit Disorder Succeed In A College Mathematics Class, Pamela E. Matthews

Humanistic Mathematics Network Journal

No abstract provided.

John Dewey, The Math And Science Standards, And The Workplace, Bernard A. Fleishman

Humanistic Mathematics Network Journal

No abstract provided.

Inspiration In England, Mary Mcdermott

Humanistic Mathematics Network Journal

No abstract provided.

A Course In Mathematical Ethics, Robert P. Webber

Humanistic Mathematics Network Journal

No abstract provided.

Book Review: Nexus: Architecture And Mathematics, Edited By Kim Williams, Joseph Malkevitch

Humanistic Mathematics Network Journal

No abstract provided.

Management Options For Pilbara Demersal Line Fishing, Gaye Looby

Fisheries Management Papers

Fisheries Western Australia licensing arrangements allow all vessels with an unrestircted fishing boat licence ('wetline licence') to take scalefish throughout the State. These arrangements have led to a high level of excess capacity in the licensed 'wetline' fishing fleet to exploit the scalefish resources. The declaration of the Kimberley Interim Line Fishery and forthcoming declaration the Northern Demersal Scalefish Fishery have resolved this problem for the Kimberley waters. However, the high level of excss capacity in the 'wetline' fleet to exploit the waters of the Pilbara remains a problem Preview access and develop a management plan for the Pilbara demersal …

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.

Evolution Of Secondary Electron Emission Characteristics Of Spacecraft Surfaces, R. E. Davies, John R. Dennison

All Physics Faculty Publications

Secondary electron emission (SEE) plays a key role in spacecraft charging [Garrett, 1981; Frooninckx and Sojka, 1992] . As a result, spacecraft charging codes require knowledge of the SEE characteristics of various materials in order to predict vehicle potentials in various orbital environments [Katz, et. al., 1986]. Because SEE is a surface phenomenon, occurring in the first few atomic layers of a material, the SEE characteristics of a given surface are extremely sensitive to changes in surface condition--e.g., the addition or removal of surface contaminants, or changes in surface morphology. That spacecraft surfaces can and generally do undergo significant evolution …

Image Measurements Of Short Period Gravity Waves At Equatorial Latitudes, Michael J. Taylor, W. R. Pendleton Jr., S. Clark, H. Takahashi, D. Gobbi, R. A. Goldberg

All Physics Faculty Publications

A high-performance, all-sky imaging system has been used to obtain novel data on the morphology and dynamics of short-period (<1 hour) gravity waves at equatorial latitudes. Gravity waves imaged in the upper mesosphere and lower thermosphere were recorded in three nightglow emissions, the near-infrared OH emission, and the visible wavelength OI (557.7 nm) and Na (589.2 nm) emissions spanning the altitude range ∼80–100 km. The measurements were made from Alcantara, Brazil (2.3°S, 44.5°W), during the period August-October 1994 as part of the NASA/Instituto Nacional de Pesquisas Espaciais “Guara campaign”. Over 50 wave events were imaged from which a statistical study of the characteristics of equatorial gravity waves has been performed. The data were found to divide naturally into two groups. The first group corresponded to extensive, freely propagating (or ducted) gravity waves with observed periods ranging from 3.7 to 36.6 min, while the second group consisted of waves of a much smaller scale and transient nature. The later group exhibited a bimodal distribution for the observed periods at 5.18 ± 0.26 min and 4.32 ± 0.15 min, close to the local Brunt-Vaisala period and the acoustic cutoff period, respectively. In comparison, the larger-scale waves exhibited a clear tendency for their horizontal wavelengths to increase almost linearly with observed period. This trend was particularly well defined around the equinox and can be represented by a power-law relationship of the form λ h = ( 3.1 ± 0.5 ) τ ob 1.06 ± 0.10 , where λ h is measured in kilometers and τob in minutes. This result is in very good agreement with previous radar and passive optical measurements but differs significantly from the relationship λ h ∝ τ105 ob inferred from recent lidar studies. The larger-scale waves were also found to exhibit strong anisotropy in their propagation headings with the dominant direction of motion toward the-NE-ENE suggesting a preponderance for wave generation over the South American continent.

Geology Newsletter- 1997, Department Of Geology

Geological and Environmental Sciences News

Vol. 1, No. 22

• Dear Alumni and Friends
• Faculty News
• Awards and Scholarships
• Alumni News
• Geology Development and Scholarship Donations
• Advisory Council News

Center For Sustainable Agricultural Systems Newsletter, November/December 1997

Center for Sustainable Agricultural Systems: Newsletter (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

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 9, November 1997, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A twelve page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Spectrum Of Hot O At The Exobases Of The Terrestrial Planets, Jane L. Fox, Aleksander B. Hać

Physics Faculty Publications

The distribution of energetic O produced in dissociative recombination of O₂⁺ at the exobases of the terrestrial planets is important in determining the structure of the outer hot O coronas and for the escape flux of O from Mars. Using recently measured values for the branching ratios of the energetically allowed channels in O₂⁺ dissociative recombination, along with models of the vibrational distribution of O₂⁺, we compute the velocity distribution of hot O atoms produced at the exobases of Mars, Venus, and Earth. We take into account the effects of the ion and …

Simulation Study Of Learning Automata Games In Automated Highway Systems, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

One of the most important issues in Automated Highway System (AHS) deployment is intelligent vehicle control. While the technology to safely maneuver vehicles exists, the problem of making intelligent decisions to improve a single vehicle’s travel time and safety while optimizing the overall traffic flow is still a stumbling block. We propose an artificial intelligence technique called stochastic learning automata to design an intelligent vehicle path controller. Using the information obtained by on-board sensors and local communication modules, two automata are capable of learning the best possible (lateral and longitudinal) actions to avoid collisions. This learning method is capable of …

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). …

Updated Measurement Of The Τ Lepton Lifetime, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A new measurement of the mean lifetime of the τ lepton is presented. Three different analysis methods are applied to a sample of 90000 τ pairs, collected in 1993 and 1994 with the ALEPH detector at LEP. The average of this measurement and those previously published by ALEPH is ττ = 290.1±1.5±1.1fs.

Analysis Of Uranium Oxide Weathering By Molecular Spectroscopy, Matthew S. Zickafoose

Theses and Dissertations

A preliminary study of the weathering of uranium oxide particles diluted in diamond dust at ambient environmental conditions is presented. The primary weathering reaction is oxidation of the uranium from the 4 to 6 oxidation state, although formation of compounds such as carbonates and hydroxides is possible. Identification of the state of uranium oxide has been attempted using luminescence spectroscopy and diffuse reflectance Fourier transform infrared spectroscopy DRIFTS. Luminescence spectra of nominal samples of three common oxides, UO3, U3O8, and UO2, have been measured showing significant spectral differences in peaks at 494 nm, 507 nm, 529 nm, and 553 nm. …

Evaluation Of Constructed Wetlands On Phosphate Mined Lands In Florida, G. R. Best, M. T. Brown, Thomas Crisman, Keven L. Erwin, D. A. Graetz, K. R. Reddy, H. Kale, P. Pritchard, T. M. Missimer, C. W. Walker, A. Owosina, M. J. Deuver

School of Geosciences Faculty and Staff Publications

Summarizing research conducted from June 1993 to May 1995 on hydrology, soils, water quality, and aquatic fauna on phosphate mined lands in Florida.

Vic*: A Compiler For Virtual-Memory C*, Alex Colvin, Thomas H. Cormen

Computer Science Technical Reports

This paper describes the functionality of ViC*, a compiler for a variant of the data-parallel language C* with support for out-of-core data. The compiler translates C* programs with shapes declared outofcore, which describe parallel data stored on disk. The compiler output is a SPMD-style program in standard C with I/O and library calls added to efficiently access out-of-core parallel data. The ViC* compiler also applies several program transformations to improve out-of-core data layout and access.

Molecular Fluorescence At A Rough Surface: The Orientation Effects, P.T. Leung, W. L. Blacke

Physics Faculty Publications and Presentations

The problem of the dynamical interaction between an emitting dipole and a metallic grating surface is considered with particular interest in the effects due to different orientations of the dipole with respect to the substrate surface. Our previous perturbative theory is extended to treat both parallel and perpendicular dipoles and the results are applied to the study of modified fluorescence characteristics for admolecules in the vicinity of a rough metal surface modeled as a grating. Numerical results show that some of the characteristics are very sensitive to the molecular orientation and the one along the grating direction is manifested with …

Task Scheduling In Networks, Cynthia Phillips, Clifford Stein, Joel Wein

Dartmouth Scholarship

Scheduling a set of tasks on a set of machines so as to yield an efficient schedule is a basic problem in computer science and operations research. Most of the research on this problem incorporates the potentially unrealistic assumption that communication between the different machines is instantaneous. In this paper we remove this assumption and study the problem of network scheduling, where each job originates at some node of a network, and in order to be processed at another node must take the time to travel through the network to that node.

Our main contribution is to give approximation algorithms …

Salinity And Hydrology Of The Mills Lake Catchment, R Ferdowsian, A T. Ryder

Resource management technical reports

The Mills Lake Catchment is located north of the Ongerup-Jerramungup Road, 35 km west of Jerramungup and 10 km north-east of Ongerup. It covers about 23,800 ha of agricultural land that is more than 90% cleared and predominantly cropped. The average annual rainfall of the catchment is about 370 mm. Many low-lying parts of the study area have become salt-affected during recent years. The extent of soil salinity is growing rapidly and it is feared that, without any treatment, more land will become salt-affected.

Qos And Reliability Models For Network Computing, Ladislau Bölöni, Kyung Koo Jun, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.