Physical Sciences and Mathematics Commons^™

Η Production In Peripheral Heavy-Ion Collisions, Alec Schramm, Daniel Reeves

Alec J Schramm

We estimate the impact parameter dependence of the production cross section for ηc and ηb mesons in peripheral heavy-ion collisions. Total and elastic γγ cross sections are calculated in an equivalent photon approximation.

Results Of The City Of Tampa Surface Water Compliance Monitoring Program For The Year 1995 And Examination Of Long-Term Water Quality And Biological Indicator Trends In Hillsborough Bay, City Of Tampa Department Of Sanitary Sewers

Reports

This report is submitted to the Florida Department of Environmental Protection (FDEP) to satisfy the requirements set forth in specific condition No. 14 of the Howard F. Curren WWTP permit No. D029-184532B. The report is based on data obtained by the City of Tampa (COT) compliance water quality monitoring program approved under construction permit DC29-152799. The report also includes examination of long-term trends for water quality parameters and biological indicators collected by the City of Tampa Bay Study Group and the Environmental Protection Commission of Hillsborough County (EPC).

Background Paper On "Power Line Fields And Public Health", David W. Hafemeister

Physics

No abstract provided.

File-Access Characteristics Of Parallel Scientific Workloads, Nils Nieuwejaar, David Kotz, Apratim Purakayastha, Carla Schlatter Ellis, Michael Best

Computer Science Technical Reports

Phenomenal improvements in the computational performance of multiprocessors have not been matched by comparable gains in I/O system performance. This imbalance has resulted in I/O becoming a significant bottleneck for many scientific applications. One key to overcoming this bottleneck is improving the performance of parallel file systems.

The design of a high-performance parallel file system requires a comprehensive understanding of the expected workload. Unfortunately, until recently, no general workload studies of parallel file systems have been conducted. The goal of the CHARISMA project was to remedy this problem by characterizing the behavior of several production workloads, on different machines, at …

Some Problems In Joint Spectral Theory., Tirthankar Bhattacharya Dr.

Doctoral Theses

No abstract provided.

Statistical Multifragmentation In Central Au+Au Collisions At 35 Mev/U, M. D'Agostino, A. S. Botvina, P. M. Milazzo, M. Bruno, G. J. Kunde, D. R. Bowman, L. Celano, N. Colonna, J. D. Dinius, A. Ferrero, M. L. Fiandri, C. K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, D. Horn, W. C. Hsi, M. Huang, I. Iori, M. A. Lisa, W. G. Lynch, L. Manduci, G. V. Margagliotti, P. F. Mastinu, I. N. Mishustin, C. P. Montoya, A. Moroni, Graham F. Peaslee, F. Petruzzelli, L. Phair, R. Rui, C. Schwarz, M. B. Tsang, G. Vannini, C. Williams

Faculty Publications

Multifragment disintegrations, measured for central Au + Au collisions at , are analyzed with the Statistical Multifragmentation Model. Charge distributions, mean fragment energies, and two-fragment correlation functions are well reproduced by the statistical breakup of a large, diluted and thermalized system slightly above the multifragmentation threshold.

An Introduction To Lake And Reservoir Water Quality Modeling, Kenneth H. Reckhow

Technical Reports

No abstract provided.

A Queuing Analysis Of Bandwidth Allocation Schemes For Compressed Video, Saurab Nog, Carl J. Beckmann

Computer Science Technical Reports

Video and audio compression techniques allow continuous media streams to be transmitted at bit rates that are a function of the delivered quality of service. Digital networks will be increasingly used for the transmission of such continuous media streams. This paper describes an admission control policy in which the quality of service is negotiated at stream initiation, and is a function of both the desired quality of service and the available bandwidth resources. The advantage of this approach is the ability to robustly service large numbers of users, while providing increased quality of service during low usage periods. Several simple …

Function Approximation Using A Sinc Neural Network, Wael R. Elwasif, Laurene V. Fausett

Mathematics and System Engineering Faculty Publications

Neural networks for function approximation are the basis of many applications. Such networks often use a sigmoidal activation function (e.g. tanh) or a radial basis function (e.g. gaussian). Networks have also been developed using wavelets. In this paper, we present a neural network approximation of functions of a single variable, using sinc functions for the activation functions on the hidden units. Performance of the sinc network is compared with that of a tanh network with the same number of hidden units. The sinc network generally learns the desired input-output mapping in significantly fewer epochs, and achieves a much lower total …

A Century Of Accumulation And Temperature Changes In Dronning Maud Land, Antarctica, Elisabeth Isaksson, Wibjörn Karlén, Niels Gundestrup, Paul Andrew Mayewski, Sallie Whitlow, Mark Twickler

Earth Science Faculty Scholarship

A mass balance program was initiated in the Vestfjella-Heimefrontfjella area of western Dronning Maud Land during the austral summer of 1988–1989. As a part of this program, spatial and temporal variations in snow accumulation and temperature/stable isotopes are measured using shallow firn cores. In this paper we present surface accumulation data and discuss the climatic implications of the stable isotope records from two shallow firn cores. One 30-m-deep core, obtained about 200 km from the coast at 700 m asl (73°36′S, 12°26′W), covers the period 1932–1991. The other core was drilled at about 500 km from the coast at 2900 …

Laser Injection Of Ultrashort Electron Pulses Into Wakefield Plasma Waves, Donald P. Umstadter, J.K. Kim, E. Dodd

Donald Umstadter Publications

A novel laser-plasma-based source of relativistic electrons is described. It involves a combination of orthogonally directed laser beams, which are focused in a plasma. One beam excites a wakefield electron plasma wave. Another locally alters the trajectory of some of the electrons in such a way that they can be accelerated and trapped by the wave. With currently available table-top terawatt lasers, a single ultrashort-duration electron bunch can be accelerated to multi-MeV energies in a fraction of a millimeter, with femtosecond synchronization between the light pulse, the electron bunch, and the plasma wave. Both analytical and numerical-simulation results are presented.

Evaluation Of The Concentration And Enantiomeric Purity Of Selected Free Amino Acids In Fermented Malt Beverages (Beers), K. Helen Ekborg-Ott, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Even though amino acids are important trace components in the brewing of beers, they have not been extensively evaluated in these beverages. Studies involving the enantiomeric composition of these amino acids are even less prevalent. A brief summary of the brewing process for malt beverages is given. The total concentration and enantiomeric composition of three amino acids (leucine, phenylalanine, and proline) were determined in 25 different beers. Proline tended to have the highest average absolute concentration and the lowest percentage of the D-enantiomer in most samples. In some cases the relative amounts of D-phenylalanine and D-leucine exceeded 10% of the …

Computation Of Electron Affinities Of O And F Atoms, And Energy Profile Of F-H2 Reaction By Density Functional Theory And Ab Initio Methods, Branko S. Jursic

Chemistry Faculty Publications

The validity of hybrid and nonlocal DFT methods are tested on examples of systems which are difficult to model by way of quantum chemistry techniques. The electron affinities for the oxygen and fluorine atoms were calculated. The exothermicity, the barrier for the fluorine atom reaction with the hydrogen molecule, and the energy of the H–F bond and its distance were computed with DFT methods, as well as, with ROHF, MPn, and QCISD ~T! ab initio methods. The computations were performed by using various basis sets, with 6-311 11G(3d f ,3pd as the largest. The obtained results are compared …

The Expected Lifetime Of "Single-Address-Space" Operating Systems, David Kotz, Preston Crow

Computer Science Technical Reports

Trends toward shared-memory programming paradigms, large (64-bit) address spaces, and memory-mapped files have led some to propose the use of a single virtual-address space, shared by all processes and processors. Typical proposals require the single address space to contain all process-private data, shared data, and stored files. To simplify management of an address space where stale pointers make it difficult to re-use addresses, some have claimed that a 64-bit address space is sufficiently large that there is no need to ever re-use addresses. Unfortunately, there has been no data to either support or refute these claims, or to aid in …

The Astrophysical Reaction Rate For The 18f(P,Α) 15o Reaction, K. E. Rehm, M. Paul, Andrew D. Roberts, C. L. Jiang, D. Blumenthal, J. Gehring, Robert J. Nickles, J. Nolen, R. C. Pardo, J. P. Schiffer, R. E. Segel

Physics and Astronomy Department Publications

Proton and alpha widths for a 3/2+ ( l p = 0) state in 19Ne at Ex-7.1 MeV have been extracted using the results of recent measurements of the 18F(p,α)15O reaction. This l p = 0 resonance dominates the astrophysical reaction rates at temperatures T9>0.5.

Huxley Hotline, 1996, March 13, Traci Edge, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.

Air Quality And Transportation On Colorado's Front Range: Taking Responsibility For Difficult Choices, Wade Buchanan, David A. Pampu, Christine Lipaj Shaver, University Of Colorado Boulder. Natural Resources Law Center

Air Quality and Transportation on Colorado's Front Range: Taking Responsibility for Difficult Choices (March 12)

15 pages.

Collection of 3 papers presented at the Hot Topics in Natural Resources Law program held on March 12, 1996.

Includes biographical information for Wade Buchanan, David A. Pampu, and Christine Lipaj Shaver.

With communities along Colorado's Front Range continuing to grow at a rapid rate, government, private businesses and citizens are faced with difficult choices concerning air quality and transportation. Can we control the "brown cloud" and increasing congestion on our roads and freeways? What decisions and sacrifices must be made, and who will take responsibility for them? Wade Buchanan, Chairman of the Regional Air Quality Council (RAQC), …

Categorization Of Programs Using Neural Networks, Franz J. Kurfess, Lonnie R. Welch

Computer Science and Software Engineering

This paper describes some experiments based on the use of neural networks for assistance in the quality assessment of programs, especially in connection with the reengineering of legacy systems. We use Kohonen networks, or self-organizing maps, for the categorization of programs: programs with similar features are grouped together in a two-dimensional neighbourhood, whereas dissimilar programs are located far apart. Backpropagation networks are used for generalization purposes: based on a set of example programs whose relevant aspects have already been assessed, we would like to obtain an extrapolation of these assessments to new programs. The basis for these investigation is an …

Equatorial Wind Compression Effects Across The H-R Diagram., R. Ignace, J. P. Cassinelli

Richard Ignace

We investigate the degree to which moderate stellar rotation rates can influence the two-dimensional density structure in the winds of four classes of stars: WoIf-Rayet, B[e], asymptotic giant branch (AGB), and novae. These classes are distributed across the H-R diagram and have a wide range of escape speeds and wind acceleration. Furthermore, all have members which possess asymmetric circumstellar nebulae. It has been suggested that these asymmetries could result from stellar winds which have moderate equatorial density enhancements. Large enhancements may arise as the result of stellar rotation as demonstrated by the wind-compressed disk (WCD) model of Bjorkman & Cassinelli. …

Thermal Nucleation And Cavitation In Helium-3 Fluids, Xiao Cheng Zeng, D.W. Oxtoby, E. Cheng

Xiao Cheng Zeng Publications

We have investigated droplet nucleation and bubble cavitation in the quantum fluid helium-3 based on a nonlocal density-functional approach. A marked effect of droplet (or bubble) curvature on the rate of droplet nucleation or cavitation has been found. Without considering this curvature effect (as in the classical theory of nucleation) the droplet nucleation rate for helium-3 could be underestimated (i.e., near 1 K) or overestimated (i.e., near 2.5 K) by orders of magnitude, respectively; for bubble cavitation, the rate could be underestimated by more than twenty orders of magnitude (near 1 K).

An Rpc Mechanism For Transportable Agents, Saurab Nog, Sumit Chawla, David Kotz

Computer Science Technical Reports

Transportable agents are autonomous programs that migrate from machine to machine, performing complex processing at each step to satisfy client requests. As part of their duties agents often need to communicate with other agents. We propose to use remote procedure call (RPC) along with a flexible interface definition language (IDL), to add structure to inter-agent communication. The real power of our Agent RPC comes from a client-server binding mechanism based on flexible IDL matching and from support for multiple simultaneous bindings. Our agents are programmed in Agent Tcl; we describe how the Tcl implementation made RPC particularly easy to implement. …

Obat Telinga Berdengung, Riswan Alfarid

Riswan Alfarid

The Virginia Wetlands Report Vol. 11, No. 2, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Northern Harrier, or Marsh Hawk. Julie G. Bradshaw
• Bay Anchovy. Lyle Varnell
• Geographic Information System (GIS) Data Exchange- The State of the Problem, Part 2. Marcia Berman
• General Assembly Passes, and Governor Signs Wetlands Mitigation Banking Legislation.
• Second Edition of the Virginia Wetlands Management Handbook Now Available.
• Wetlands Management Symposium: Wetlands Compensation Survey Results
• Westmoreland State Park. Pam Mason
• Literally, what is littoral sand movement? William Roberts

Estimating Value Contribution Of Tree And Stand Condition, R. Joss Hanna, Richard P. Thompson, Douglas D. Piirto, Jay E. Noel

Natural Resources Management and Environmental Sciences

Key issues in encouraging forest management at the interface level in the oak woodlands are fire abatement, stand improvement, infection reduction, and hazard tree removal. The development of effective management prescriptions for stand improvement and economic returns provide guidance for homeowners, appraisers, and realtors. The purpose of this research project was to determine the effects of stand characteristics (e.g., structure, density and health) on the value of urban/interface forested properties. In this study, the forest characteristic coefficients were statistically significant with an estimated value contribution of about $30,000 each, or over 22 percent of the median property’s value ($262,079).

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 3, March 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Divergence Diagrams: More Than Cantor Dust Lies At The Edge Of Feigenbaum Diagrams, John H. Rickert, Aaron Klebanoff

Mathematical Sciences Technical Reports (MSTR)

The dynamical system analysis of the logistic map f(x)=ax(1-x) is studied for values of a greater than 4.

Signal Averaging X-Ray Streak Camera With Picosecond Jitter, Anatoly Maksimchuk, M. Kim, J. Workman, G. Korn, J. Squier, D. Du, Donald Umstadter, G. Mourou, M. Bouvier

Donald Umstadter Publications

We have developed an averaging picosecond x-ray streak camera using a dc-biased photoconductive switch as a generator of a high-voltage ramp. The streak camera is operated at a sweep speed of up to 8 ps/mm, shot-to-shot jitter is less than ±1 ps. The streak camera has been used to measure the time history of broadband x-ray emission from an ultrashort pulse laser-produced plasma. Accumulation of the streaked x-ray signals significantly improved the signal-to-noise ratio of the data obtained.

Combinatorics Of Open Covers (I): Ramsey Theory, Marion Scheepers

Mathematics Faculty Publications and Presentations

We study several schemas for generating from one sort of open cover of a topological space a second sort of open cover. Some of these schemas come from classical literature, others are borrowed from the theory of ultrafilters on the set of positive integers. We show that the fact that such a schema actually succeeds in producing a cover imposes strong combinatorial structure on the family of open covers of a certain sort. In particular, we show that certain analogues of Ramsey’s theorem characterize some of these circumstances.

Nonlinear Noise Reduction For Electrocardiograms, Daniel T. Kaplan, T. Schreiber

Daniel T. Kaplan

No abstract provided.

Temporal Variability Of Organic C And Nitrate In A Shallow Aquifer, D. E. Clay, S. A. Clay, T. B. Moorman, K. Brix-Davis, K. A. Scholes, A. R. Bender

Agronomy, Horticulture and Plant Science Faculty Publications

The loading of organic substrates into shallow aquifers may follow seasonal cycles, which will impact the transport and fate of agrichemicals. The objective of this research was to measure temporal changes in the groundwater dissolved organic C (DOC) and nitrate concentrations. Groundwater monitoring wells were installed and sediment samples from the aquifer were collected in 1991. Sediment samples were used to evaluate denitrification potentials, while water samples were collected at periodic intervals in 1992 and 1993 from the surface of the aquifer. Water samples were analyzed for nitrate-N and DOC-C. Denitrification was observed in sediment amended with nitrate and incubated …