Physical Sciences and Mathematics Commons^™

Measurements Of Methane Emissions From Rice Fields In China, M. A. K. Khalil, R. A. Rasmussen, Martha J. Shearer, R. W. Dalluge, Lixin Ren, Chang-Lin Duan

Physics Faculty Publications and Presentations

Rice fields have always been regarded as one of the largest anthropogenic sources of atmospheric methane. Here we report the results of a 7-year study of methane emissions from rice fields in the Sichuan Province of China. In this region, there is one crop of rice per year, the fields are continuously flooded from transplanting to harvest, and there is heavy use of organic fertilizers. Emissions over the entire growing season were measured from each of up to 24 plots. Environmental variables were measured and relevant supporting data on the agricultural practices were recorded. The fields were studied under prevailing …

Factors Affecting Methane Emissions From Rice Fields, M. A. K. Khalil, R. A. Rasmussen, Martha J. Shearer, R. W. Dalluge, Lixin Ren, Chang-Lin Duan

Physics Faculty Publications and Presentations

Methane emissions from rice fields are affected by a number of environmental and agricultural factors. We have analyzed our 7-year data set on methane emissions from rice fields in Tu Zu, China, to delineate the relationships between emissions and a number of variables that were measured at the same time. Our work was done in fields that were managed under prevailing agricultural practices of the region. Consequently, only the effect of factors that vary from year to year or during the growing season can be calculated. In our study we measured the effects of environmental variables (soil temperature, wind speed, …

Flux Measurements And Sampling Strategies: Applications To Methane Emissions From Rice Fields, M. A. K. Khalil, R. A. Rasmussen, Martha J. Shearer

Physics Faculty Publications and Presentations

The emissions of methane from rice fields and other sources are often measured by placing chambers on the surface and taking sequential samples. Although static chambers pose several problems that affect the accuracy of the data, there are a few parameters that, if carefully chosen, can improve the reliability of the data and reduce the uncertainties. These parameters are the length of time the chamber is kept on the rice plants, the number of samples that are drawn to estimate the flux, the basal area and height of the chamber, the frequency of measurements during the growing season, and the …

Target Dependence Of The Triply Differential Cross Section For Low Energy (E, 2e) Processes, Cheng Pan, Anthony F. Starace

Anthony F. Starace Publications

The main purpose of this chapter is to review our calculations, whose aim is to explain the target dependence of the triply differential cross sections that has been observed in a number of recent experiments performed at relatively low energies above the ionization threshold for the two outgoing electrons leaving in opposite directions (θ₁₂ = π). One reason for focusing on this θ₁₂ = π geometry is that it is the most important geometry for near-threshold double-escape processes in the WPR theory. Another reason is that up to now, except for H and He targets, the triply differential …

The Electromagnetic Field Near A Dielectric Half-Space, Andrew Lang, Dr. Adam D. Helfer

College of Science and Engineering Faculty Research and Scholarship

We compute the expectations of the squares of the electric and magnetic fields in the vacuum region outside a half-space filled with a uniform non-dispersive dielectric. This gives predictions for the Casimir-Polder force on an atom in the "retarded" regime near a dielectric. We also find a positive energy density due to the electromagnetic field. This would lead, in the case of two parallel dielectric half-spaces, to a positive, separation-independent contribution to the energy density, besides the negative, separation-dependent Casimir energy. Rough estimates suggest that for a very wide range of cases, perhaps including all realizable ones, the total energy …

Two-Surface Virial Analysis Of Alkane Adsorption On Carbopack C With And Without Hydrogen Treatment., Chrystal Bruce, Thomas Rybolt, Howard Thomas, Tara Agnew, Brandon Davis

Chrystal D. Bruce

Second gas–solid virial coefficients for propane, butane, pentane, and hexane were found for Carbopack C and Carbopack C-HT (Supelco Inc.) within the temperature range of 323 to 471 K using gas–solid chromatography in the Henry's law region of adsorption. Carbopack C and Carbopack C-HT are both graphitized carbon black powders. Treatment of Carbopack C with hydrogen at 1273 K converts it to Carbopack C-HT and is believed to remove certain high energy sites or “hot spots” from the carbon surface. These two surfaces provide appropriate model systems to test a two-surface virial analysis. Surface areas for both powders were calculated …

Ionization Of Aligned Rydberg Atoms By Ion Impact, K. R. Cornelius, J. Wang, Ronald E. Olson

Physics Faculty Research & Creative Works

The classical trajectory Monte Carlo method has been used to calculate capture and ionization cross sections and final-state electron momentum distributions in H+ + H(n = 25) collisions to show how the collision mechanisms evolve over the range of intermediate projectile speeds v* = vp/ve = 1.0-5.0. A circular Rydberg target was aligned in two orientations defined by the orbital angular momentum vector of the electron being either antiparallel or perpendicular to the incident momentum vector of the projectile. Aligning the target atom in this manner helps us to single out specific collision processes otherwise obscured in a randomly oriented …

Stochastic Methods For Evaluating The Potential For Wetland Rehydration In Covered-Karst Terranes, Christian David Langevin

USF Tampa Graduate Theses and Dissertations

Augmentation with reclaimed water is one method for rehydrating wetlands damaged by water-level declines. Augmentation with reclaimed water has been proposed for rehydrating a wetland in the covered-karst terrane of west-central Florida. There is concern because reclaimed water may contain harmful agents that could flow from the wetland 1.4 km to a municipal wellfield that withdraws 30,000 m³/day. Estimates of groundwater flow velocities were calculated from the results of detailed field studies at the wetland. Results indicate that groundwater flows downward in the surficial aquifer at rates of 0.1 to 0.2 m/day and horizontally in the Floridan aquifer …

The Penrose Dodecahedron Revisited, Padmanabhan Aravind, Jordan Massad

Padmanabhan K. Aravind

This paper gives an elementary account of the ‘‘Penrose dodecahedron,’’ a set of 40 states of a spin- 3 2 particle used by Zimba and Penrose @Stud. Hist. Phil. Sci. 24, 697–720 ~1993!# to give a proof of Bell’s nonlocality theorem. The Penrose rays are constructed here from the rotation operator of a spin- 3 2 particle and the geometry of a dodecahedron, and their orthogonality properties are derived and illustrated from a couple of different viewpoints. After recalling how the proof of Bell’s theorem can be reduced to a coloring problem on the Penrose rays, a ‘‘proof-tree’’ argument is …

Half-Cycle Pulse Assisted Electron-Ion Recombination, Thomas J. Bensky, M. B. Campbell, Robert R. Jones

Physics

Unipolar “half-cycle” electric field pulses (HCPs) have been used to recombine free electrons and calcium ions. The field assisted process is very similar to controlled three-body recombination in plasmas. We report on experiments that utilize HCP assisted recombination to probe the probability distribution of continuum electron wave packets and produce bound wave packets that are highly localized in three spatial dimensions.

Molecular Gas In The Z = 2.8 Submillimeter Galaxy Smm 02399-0136, D T. Frayer, R J. Ivison, N Z. Scoville, Min S. Yun, A S. Evans, Ian Smail, A W. Blain, J P. Kneib

Min S. Yun

We report the detection of CO (3→2) emission from the submillimeter-selected hyperluminous galaxy SMM 02399-0136. This galaxy is the brightest source detected in the recent Submillimeter Common-User Bolometer Array surveys of the submillimeter sky. The optical counterpart of the submillimeter source has been identified as a narrow-line active galactic nucleus/starburst galaxy at z=2.8. The CO emission is unresolved, θlesssim5'', and is coincident in redshift and position with the optical counterpart. The molecular gas mass derived from the CO observations is 8×1010 h−275 M_{{\odot}}, after correcting for a lensing amplification factor of 2.5. The large CO luminosity suggests that a significant …

Time Series Energy Production In Smoothed Particle Hydrodynamics Accretion Disks: Superhumps In The Am Canum Venaticorum Stars, James C. Simpson, Matt A. Wood

Aerospace, Physics, and Space Science Faculty Publications

The energy production time series of our purely hydrodynamic accretion disk simulations display remarkable similarities with the observed light curves of dwarf novae superhumps in general and the AM CVn stars in particular. The superhump period excess as a function of mass ratio agrees well with earlier theoretical and numerical results, and the amplitudes and relative phases of the harmonics in the power spectra agree well with the observations. The morphology of the mean pulse profile appears to be a useful predictor of system mass ratio. Our modified smoothed particle hydrodynamics code time symmetrizes the interparticle forces when individual time …

Temperature Fluctuations In Photoionized Nebulae. Ii. The Effect Of Inhomogeneous Abundances, J. B. Kingdon, Gary J. Ferland

Physics and Astronomy Faculty Publications

Recent abundance determinations based on recombination lines in several emission-line nebulae yield ionic abundances several times larger than those derived from forbidden lines. These results cast uncertainty over all abundance determinations in such objects. One possible explanation for these discrepancies frequently cited in the literature is the presence of chemical inhomogeneities. We have run a series of photoionization models to examine what effect such inhomogeneities will have on the resulting temperature structure of nebulae. We then derive abundances from these models, utilizing Peimbert's t² formalism. Our results suggest that, although chemical inhomogeneities may produce nonnegligible biases in abundance determinations …

Measurement Of Elastic Υ Photoproduction At Hera, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

The photoproduction reaction γp → μ+ μ-p has been studied in ep interactions using the ZEUS detector at HERA. The data sample corresponds to an integrated luminosity of 43.2pb-1. The Υ meson has been observed in photoproduction for the first time. The sum of the products of the elastic Υ(1S), Υ(2S),Υ(3S) photoproduction cross sections with their respective branching ratios is determined to be 13.3 ± 6.0(stat.)-2.3+2.7(syst.) pb at a mean photon-proton centre of mass energy of 120 GeV. The cross section is above the prediction of a perturbative QCD model. © 1998 Elsevier Science B.V. All rights reserved.

Evaluation Of The Macrocyclic Antibiotic Avoparcin As A New Chiral Selector For Hplc, K. Helen Ekborg-Ott, John P. Kullman, Xiande Wang, Kyung Gahm, Lingfeng He, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Avoparcin is a macrocyclic glycopeptide antibiotic structurally related to vancomycin, teicoplanin, and ristocetin A. When attached to 5-μm spherical silica gel, the avoparcin proved to be an effective chiral stationary phase (CSP) that could be used in the reversed-phase, normal- phase, and polar-organic modes. The avoparcin CSP was complimentary to the other macrocyclic glycopeptide CSPs in that it could resolve some racemates that the others could not, and vice versa. Some important compounds resolved on the avoparcin CSP include verapamil, thyroxine, mephenytoin, and 2- imidazolidone-4-carboxylic acid. The use of this CSP and the optimization of separations on it are discussed. …

The Voltammetry Of Fullerenes And Metallofullerenes, Mark Anderson

Mark R. Anderson

No abstract is available at this time.

Utility Driven Mobile-Agent Scheduling, Jonathan Bredin, David Kotz, Daniela Rus

Computer Science Technical Reports

Mobile agents are programs capable of migrating from one host machine to another. We propose that mobile agents purchase resource access rights from host machines thereby establishing a market for computational resources and giving agents a metric to evenly distribute themselves throughout the network. Market participation requires quantitative information about resource consumption to define demand and calculate utility. We create a formal utility model to derive user-demand functions, allowing agents to efficiently plan expenditure and deal with price fluctuations. By quantifying demand and utility, resource owners can precisely set a value for a good. We simulate our model in a …

The Virginia Wetlands Report Vol. 13, No. 3, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Tundra Swan. Julie G. Bradshaw
• What kind of educational courses and publications does the Wetlands Program offer? William Roberts
• Mummichog. Lyle Varnell
• Using Remote Sensing and GIS To Perform Jurisdictional Wetlands Determinations. Marcia Berman
• United States v. Wilson: Muddy Waters in the Search for Wetlands Protection. S. Fagan and Jim Perry
• Responding to the Chesapeake Executive Council Directive for Wetlands Protection and Restoration Goals. Carl Hershner
• Wetlands: A Critical Resource in the Revolutionary War? Pam Mason

From The Director: October 1998, Donald A. Wilhite

Drought Network News (1994-2001)

On July 16, 1998, President Clinton signed the National Drought Policy Act into law. This law creates the National Drought Policy Commission (NDPC), which will examine current laws and programs and make recommendations to the president and Congress on the needs for a national drought policy. The Farm Service Agency of the U.S. Department of Agriculture will serve as the chair for the Commission, which will comprise 16 members. In addition to the Secretary of Agriculture, other members of the Commission will include the Secretary of the Interior, Secretary of the Army, Secretary of Commerce, Director of the Federal Emergency …

Comparative Hydrometeorology Of Temperate And Semiarid Environments In India, Badrul Hasan

Drought Network News (1994-2001)

Out of a total cropped area of 178 m ha, India has 59 m ha of irrigated cropland. The remaining 119 m ha is rainfed. Crop production under rainfed conditions either occurs during the rainy season or depends on conserved or residual soil moisture. In temperate countries, the economy largely depends on production of goods and services that are less affected by the variabilities of weather. Although India receives adequate amounts of rainfall annually through the four different types of weather phenomena—southwest monsoon (74%), northeast monsoon (3%), pre-monsoon (13%), and post-monsoon (10%)—the distribution in time and space is erratic, resulting …

Persian Gulf Sea Surface Temperature As A Drought Diagnostic For Southern Iran, M. Jafar Nasemosadat

Drought Network News (1994-2001)

The Persian Gulf and Oman Sea, situated over the northwestern extremity of the tropical Indian Ocean, make up the southern border of Iran (Figure 1). During hot seasons, the sea surface temperatures (SSTs) of these water bodies are high, and a huge thermal trough system is usually dominant over the region (Bitan and Sa’aroni, 1992). The summer SSTs of the Persian Gulf are reported to be the highest in the world (Gabler, 1977).

About 30% of the total rain-bearing air masses coming to the country originate in north Africa, the Red Sea, and western Saudi Arabia (Khalili, 1992). These air …

Water Current, Volume 30, No. 5, October 1998

Water Current Newsletter

Interstate Compact Opinions Vary on Summer Tour
From the Director: Unit Staff Travel to September Events; Promoting a National Water Research Initiative; State Funding Review
Volunteers Help Improve Water Quality in Elm Creek Watershed Project
Cooperation Highlights Water Quality Tour
Water Quality Monitoring Workshop Targets Nebraska and Iowa Educators
Bringing Groundwater to Life
AWRA Call for Abstracts
SNRS Debuts Seminar Series
Water News Briefs
Elm Creek Project Wraps-Up
Valuing Prairie Wetlands
Second Annual NOFEE Conference to Hastings
Strategies for Coping with Pesticide Monitoring

Announcements: October 1998

Drought Network News (1994-2001)

Contents:

IUGG–99 XXII General Assembly - Inter-Association Symposium on Geophysical Hazards: Risk Assessment, Mitigation and Warning Systems

1999 National Disaster Medical System Conference

International Conference on Integrated Drought Management—Lessons for Sub-Saharan Africa

4th International Congress on Energy, Environment and Technological Innovation

Droughts In Tamil Nadu: A Qualitative And Quantitative Appraisal, K. K. Nathan

Drought Network News (1994-2001)

Tamil Nadu experiences recurrent droughts. Tamil literature also indicates that famine-like conditions prevailed during the Pandiyan Kingdom for nearly 12 years. The state normally benefits from northeast monsoon rainfall from October to December, unlike other regions of India, which are dominated by southwest monsoon rainfall.

In general, four major parameters determine the nature and extent of drought conditions in Tamil Nadu: (1) rainfall, (2) ground water, (3) reservoir levels, and (4) crop conditions. It is estimated that nearly 50% of the districts in the state are drought-prone. The state receives nearly 80% of its annual rainfall during the northeast monsoon, …

Circulation, Vol. 6, No. 1, Center For Coastal Physical Oceanography, Old Dominion University

CCPO Circulation

Fall 1998 issue of CCPO Circulation featuring article "Renewed Effort by Mexican Oceanographers to Understand the Dynamics of Coastal Lagoons"

Student Fact Book, Fall 1998, Twenty Second Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University

Wright State University Student Fact Books

The student fact book has general demographic information on all students enrolled at Wright State University for Fall Quarter, 1998.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 14, Number 8, October 1998, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Best Practices For Tourism Center Development Along The Red Sea Coast, Stephen M. Reeve, Stephen C. Jameson, Ragaei S. Abdel-Fattah, Bernhard Riegl, Randa Hassan, Alvin P. Newman

Marine & Environmental Sciences Faculty Reports

The spectacular coastlines along Egypt's Red Sea and Gulf of Aqaba are the focus for one of the fastest growing tourism economies in the world. In order to accomplish national objectives for growth in permanent, well-paying jobs and in foreign exchange earnings, the Tourism Development Authority (TDA) has launched an initiative to make land available to investors for resort development along these coastlines. As of December, 1997, 6,000 hotel rooms are under construction in the Red Sea region and the TDA has proposals for at least 240 major resorts to be built by the year 2020.

While this program has …

Fall 1998, Nsu Oceanographic Center

Currents

No abstract provided.

Spalanie Odpadów Niebezpiecznych W Piecach Cementowych. Część 2. Destrukcja Paliwa I Emisja Zanieczyszczeń, Robert Oleniacz

Robert Oleniacz

Conditions occurring in cement rotary kilns assure high destruction and removal efficiency (DRE) of the most stable substances, efficacious dry sorption of acid gases in the alkaline raw meal and heavy metals bounding in the clinker. Adequate operation of hazardous waste incineration in the process connected with cement clinker production does not cause increasing air pollutant emissions. Magnitude of the emissions often does not depend of this if there are using wastes in the cement kiln at all. The work presents a review of DRE levels and stack emissions for selected flue-gas constituents during hazardous waste co-combustion in cement kilns …