Physical Sciences and Mathematics Commons^™

Review Of Planting The Future: Developing An Agriculture That Sustains Land And Community Edited By Elizabeth A. R. Bird, Gordon L. Bultena, And John C. Gardner, Charles A. Francis

Great Plains Research: A Journal of Natural and Social Sciences

Why should you care about agriculture? Planting the Future provides an eloquent description of the current state of this' most basic human endeavor so critical to survival. Based on a series of surveys and on-farm studies in the North Central and Western states, the book recognizes the bounty of our conventional agricultural industry. More importantly for the future, it details a series of critical problems in the environment, the distribution of economic benefits, and the social dislocation resulting from the consolidation of lands and heavy reliance on fossil fuels. Today's productivity and cheap food in the market have hidden expenses …

Mechanism Of Signal Suppression By Anionic Surfactants In Capillary Electrophoresis-Electrospray Ionization Mass Spectrometry, Kimber L. Rundlett, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Micellar-mediated capillary electrophoresis (CE) is used for a wide variety of applications, including the separation of pharmaceuticals, environmental contaminants, illicit drugs, DNA fragments, and many other biological samples. The electrospray ionization interface is one of the most common CE-MS interfaces. Coupling micellar-mediated CE separations with MS detection combines two very powerful, widely applicable analytical techniques. Some types of surfactants strongly interfere with electrospray ionization mass spectrometric (ESI-MS) detection of analytes, and in many cases the ESI-MS analyte signals are completely quenched. Only a few reports have appeared that describe the ESI-MS detection of analytes in the presence of surfactants; however, …

Impact Of Groundwater Contamination In East Multnomah County On The Interlachen Community, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt, Robert Leslie Annear, Karann Brandt

Civil and Environmental Engineering Faculty Publications and Presentations

The Friends of Blue and Fairview Lake through the Environmental Protection Agency (EPA) Technical Assistance Grant (TAG) program contracted with Portland State University faculty and staff to provide an independent review of the groundwater contamination problem at the Boeing-Cascade site in East Multnomah County. An independent consultant, Karann Brandt, of PRC Environmental Management, Inc., was also assisting the panel with the review.

The region of groundwater contamination is a 2.5 square mile region bounded by NE Halsey Blvd. to the Columbia River and NE 178th to NE 223rd (see Figure 1). The groundwater contamination is primarily of volatile organic compounds …

On The Portability Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing

Kno.e.sis Publications

Goossens defined a structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include shared variables in VHDL-93 that changes the underlying semantic model. In the presence of shared variables, non-deterministic execution of VHDL-93 processes destroys the unique meaning property. We identify and characterize a class of portable VHDL-93 descriptions for which unique meaning property can be salvaged.

Semiclassical Scattering In A Circular Semiconductor Microstructure, C. D. Schwieters, J. A. Alford, John B. Delos

Arts & Sciences Articles

The conductance of a microscopic junction shows fluctuations caused by quantum interference of waves that follow different paths between the leads. We give a semiclassical formula for these fluctuations. The theory utilizes trajectories which travel between the centers of the lead apertures; it also incorporates diffraction at these apertures. We extend the theory to include ‘‘ghost paths,’’ which scatter diffractively off the lead mouths. Semiclassical S-matrix elements are computed for a circular junction over a range of Fermi wave numbers, and the large-scale structure of these matrix elements shows good agreement with quantum results. Finally, we propose a hypothesis …

Detritus: Mother Nature's Rice Cake, Pamela Mason, Lyle M. Varnell, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

An Empirical Comparison Of Networks And Routing Strategies For Parallel Computation, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

This paper compares message routing capabilities of important networks proposed for general-purpose parallel computing. All the networks have been proven to have some type of universality property, i.e., an ability to simulate other networks of comparable cost with modest slowdown, using appropriate cost and communication models. But in this paper we seek an empirical comparison of communication capability under typical direct use rather than an analysis of worst-case results for simulating message traffic of another network.

Naticid Gastropod Prey Selectivity Through Time And The Hypothesis Of Escalation, Patricia H. Kelley, Thor A. Hansen

Geology Faculty Publications

The hypothesis of escalation posits that biologic hazards such as predation have increased during the Phanerozoic. Previously, a survey of drilling frequencies in the Cretaceous and Paleogene of the North American Coastal Plain suggested an episodic pattern of escalation within the naticid gastropod predator-prey system. This study examines escalation from the perspective of naticid prey selectivity. If escalation occurred within the system, less selectivity of prey may be apparent in the Paleogene compared to younger assemblages. We test this hypothesis for four Eocene Coastal Plain assemblages. Contrary to predictions, intraspecific prey size selectivity was well developed for nine of eleven …

Timing Of Latest Eocene Molluscan Extinction Patterns In Mississippi, David M. Hassl, Thor A. Hansen

Geology Faculty Publications

Molluscs removed from 12 bulk samples of the Yazoo Formation (upper Eocene), exposed in a quarry at Cynthia, Mississippi, are similar in com- position and diversity to those found in the underlying upper Eocene Moodys Branch Formation, when dif- ferences in outcrop area are considered (74% of the Yazoo species are also found in the Moodys Branch). This suggests there was no significant extinction during the late Eocene (at the P15/P16 biozone boundary) as has been reported for planktic foraminifera. Only 11.4% of the species from the Yazoo extend into the Oligocene Red Bluff Formation, suggesting a large molluscan extinction …

Diversity Of Arkansas Water Resources Research, Kenneth F. Steele

Technical Reports

In order to understand, protect, and manage our water resources effectively knowledge is required from many diverse areas of science, engineering, economics, and sociology. These proceedings of the conference on the Diversity of Arkansas Water Resources Research reflect this need and demonstrate how researchers in the state are responding to water issues and problems in Arkansas. The papers in these proceedings are representative of the research in Arkansas, but are only a sample of the work being conducted by universities and government agencies in Arkansas. We are grateful that Arkansas has the expertise available to provide the information necessary to …

Raman Spectroscopy Of Carbon Materials, John R. Dennison, M. Holtz, G. Swain

All Physics Faculty Publications

Use of carbon materials is no longer limited to diamond jewelry or graphite pencils and lubricants. The last decade has witnessed an explosion of technological applications driven by the development of fabrication methods and the discovery of several new classes of pure carbon. Structural diversity exhibited by the carbon atoms, from local chemical order to long-range crystalline order, is key to understanding their physical and chemical properties and in future materials development. This article summarizes the use of Raman spectroscopy as a principal tool to investigate the vibrational dynamics of carbon materials and to provide indirect structural characterization of their …

Slow Down, D. Chris Benner, Rodelle A. Benner

Arts & Sciences Articles

No abstract provided.

Low Temperature Magnetic Properties Of Siderite And Magnetite In Marine Sediments, Bernard A. Housen, S. K. Banerjee, B. M. Moskowitz

Geology Faculty Publications

Low temperature magnetic techniques provide useful tools to detect the presence of magnetite and pyrrhotite in sediments through identification of their low temperature transitions, to determine the amount of ultrafine-grained (superparamagnetic) material in sediments, and can potentially detect the presence of certain types of magnetotactic bacteria. Application of these types of experiments to nannofossil chalks from beneath the Barbados accretionary prism led to some unusual results, which are attributed to the presence of siderite. Thermal demagnetization of low-temperature remanence after cooling in zero field and in a 2.5 T field both displayed large remanence losses from 20 K to 40 …

Late Cenozoic Structure And Tectonics Of The Northern Mojave Desert, Elizabeth R. Schermer, B. P. Luyendyk, S. Cisowski

Geology Faculty Publications

In the Fort Irwin region of the northern Mojave desert, late Cenozoic east striking sinistral faults predominate over northwest striking dextral faults of the same age. Kinematic indicators and offset marker units indicate dominantly sinistral strike slip on the east striking portions of the faults and sinistral-thrust slip on northwest striking, moderately dipping segments at the east ends of the blocks. Crustal blocks ∼7–10 km wide by ∼50 km long are bounded by complex fault zones up to 2 km wide at the edges and ends of each block. Faulting initiated after ∼11 Ma, and Quaternary deposits are faulted and …

Procedurally Rational Decision-Making And Control, Richard L. Frost, Michael A. Goodrich, Wynn C. Stirling

Faculty Publications

Substantive rationality requires a decision-maker to be a utility maximizer; under this paradigm, the decision is paramount, and not dependent on the computational process used to obtain it. Procedural rationality is dependent on the method used to make the decision; reasonableness of the procedure is paramount. Well-formed problems are amenable to substantive rationality; ill-formed problems are not, but are amenable to procedural rationality. To qualify as being procedurally rational, a methodology must possess a sound epistemological basis, it must be amenable to a formal design synthesis procedure, and it must be consistent with substantive rationality. Epistemic utility theory forms the …

A Fertility Channel Model For Post-Correction Of Continuous Speech Recognition, Eric K. Ringger, James F. Allen

Faculty Publications

We have implemented a post-processor called SPEECHPP to correct word-level errors committed by an arbitrary speech recognizer. Applying a noisy-channel model, SPEECHPP uses a Viterbi beam-search that employs language and channel models. Previous work demonstrated that a simple word-for-word channel model was sufficient to yield substantial incieases in word accuracy. This paper demonstrates that some improvements in word accuracy result from augmenting the channel model with an account of word fertility in the channel. This work further demonstrates that a modern continuous speech recognizer can be used in "black-box" fashion for robustly recognizing speech for which the recognizer was not …

An Exactly Soluble Fresnel Diffraction Model Of Two-Slit Interference, James A. Lock

Physics Faculty Publications

Using the formalism of Fresnel diffraction, we examine the diffraction and interference of two initially widely separated parallel Gaussian light beams. This two-beam configuration is a version of Young's two-slit interference problem that is free of the mathematical complexity that occurs in most Fresnel diffraction calculations. As a result, it clearly and simply illustrates the transition from ray optics to wave interference. (C) 1996 American Association of Physics Teachers.

A Computational Paradigm On Network-Based Models Of Computation, Venkatavasu Bokka

Computer Science Theses & Dissertations

The maturation of computer science has strengthened the need to consolidate isolated algorithms and techniques into general computational paradigms. The main goal of this dissertation is to provide a unifying framework which captures the essence of a number of problems in seemingly unrelated contexts in database design, pattern recognition, image processing, VLSI design, computer vision, and robot navigation. The main contribution of this work is to provide a computational paradigm which involves the unifying framework, referred to as the multiple Query problem, along with a generic solution to the Multiple Query problem.

To demonstrate the applicability of the paradigm, a …

Images 2.1 : An Integrated Model Of An Arid Grazing System, Z G. Yan, K M. Wang

Resource management technical reports

The name IMAGES stands for An Integrated Model of an Arid Grazing Ecological System. The model was initiated by Dr R. Hacker in 1987-8 as an activity to (1) evaluate alternative management strategies and (2) identify key ecological processes and research priorities in shrub rangelands of Western Australia. Version 1 of the model was published in Agriculture Systems in 1991 (Hacker et al. 1991) and here after will be referred to as IMAGES 1. IMAGES 1 is a vegetation model, capable of predicting the prob ility of recruitment and mortality of the desirable species in a given vegetation type under …

An Evidential Reasoning Approach To Attribute Value Conflict Resolution In Database Integration, Ee Peng Lim, Jaideep Srivastava, Shashi Shekhar

Research Collection School Of Computing and Information Systems

Resolving domain incompatibility among independently developed databases often involves uncertain information. DeMichiel [1] showed that uncertain information can be generated by the mapping of conflicting attributes to a common domain, based on some domain knowledge. In this paper, we show that uncertain information can also arise when the database integration process requires information not directly represented in the component databases, but can be obtained through some summary of data. We therefore propose an extended relational model based on Dempster-Shafer theory of evidence [2] to incorporate such uncertain knowledge about the source databases. The extended relation uses evidence sets to represent …

Depositional Environment And Sequence Stratigraphic Interpretation Of Miocene St. Marys Formation, Calvert County, Maryland, John J. Blandin

OES Theses and Dissertations

The Miocene St. Marys Formation at Calvert Cliffs, Maryland is divided into four depositional packages made up of marine fades representing shallow shelf through intertidal conditions. These depositional packages are separated by five laterally persistent surfaces and were defined based on detailed depositional fades analysis of 24 measured sections, averaging 17 meters thick. These four packages make up two marine sequences, stratigraphic units bound above and below by surfaces of sea level fall. The lower sequence is composed of a single depositional package, while the upper sequence is composed of three upward-shallowing depositional packages (i.e. para-sequences). A fifth depositional package …

Modeling Nutrient And Plankton Processes In The California Coastal Transition Zone: 3. Lagrangian Drifters, J. R. Moisan, Eileen E. Hofmann

CCPO Publications

Two types of numerical Lagrangian drifter experiments were conducted, using a set of increasingly complex and sophisticated models, to investigate the processes associated with the plankton distributions in the California coastal transition zone (CTZ). The first experiment used a one-dimensional (1-D; vertical) time-dependent physical-bio-optical model, which contained a nine-component food web. Vertical velocities, along the track of simulated Lagrangian drifters, derived from a three-dimensional (3-D), primitive equation circulation model developed to simulate the flow observed within the CTZ; were used to parameterize the upwelling and downwelling processes. The second experiment used 880 simulated Lagrangian drifters from a 3-D primitive equation …

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

Dartmouth Scholarship

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 multiprocessor file systems. \par The design of a high-performance multiprocessor file system requires a comprehensive understanding of the expected workload. Unfortunately, until recently, no general workload studies of multiprocessor 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, …

Resource/Dataflow Graph Operating System Development, Sriram J. Coimbatore

Electrical & Computer Engineering Theses & Dissertations

Implementation of a new dataflow schedule model is the objective of this thesis. The dataflow model algorithm called the resource/dataflow graph model is implemented on a peer-to-peer communication network comprising of six personal computers. This dataflow model is implemented making use of an earlier dataflow model called ATAMM (Algorithm to Architecture Mapping Model) developed by ODU and National Aeronautics and Space Administration (NASA). Development issues include modification of the RDFG testbed operating system and a scheme to transfer data buffers using the ethernet channel from one processor to another processor. This, in turn, equips each sub-module of an application with …

Monte Carlo Simulations Of Photoemission Characteristics From Gaas And Diamond, Abhishek Srivastava

Electrical & Computer Engineering Theses & Dissertations

Monte Carlo based numerical simulations were performed to study photoemission from GaAs and diamond. The central goal was to assess the potential for NEA photoemission from diamond, and to predict its characteristics. The GaAs material system was also included in the simulation study to provide: (i) calibration and validation of the numerical model developed by carefully matching the simulation results with available experimental data, and (ii) quantitative comparisons between the response characteristics of diamond and the better known GaAs system.

Predictions of the energy distribution, temporal response and angular distribution of emitted electrons were obtained. Effects of various parameters, such …

Monitoring Zanieczyszczeń Powietrza Wokół Elektrowni "Jaworzno Iii", Marian Mazur, Robert Oleniacz, Marek Bogacki, Ryszard Kozakiewicz

Robert Oleniacz

The article presents the concept of system of monitoring of air pollution around the Power Plant "Jaworzno III" in Jaworzno (Poland), whose objective is to evaluate the impact of this object on air quality. This system is based on a few measuring points and a mobile station should also allow for the assessment of ecological effects associated with the use of low-emission burners in power boilers (reduction of NOx emission) and run the wet installation of flue gas desulfurization (reduction of SO2 emission). An additional aim of the measurements is to identify the possible effects of a changes in the …

Universality Of Spectator Fragmentation At Relativistic Bombarding Energies, A. Schüttauf, W. D. Kunze, A. Wörner, M. Begemann-Blaich, Th. Blaich, D. R. Bowman, R. J. Charity, A. Cosmo, A. Ferrero, C. K. Gelbke, C. Groß, W. C. Hsi, J. Hubele, G. Immé, I. Iori, J. Kempter, P. Kreutz, G. J. Kunde, V. Lindenstruth, M. A. Lisa, W. G. Lynch, U. Lynen, M. Mang, T. Möhlenkamp, A. Moroni, W. F.J. Müller, M. Neumann, B. Ocker, C. A. Ogilvie, Graham F. Peaslee, J. Pochodzalla, G. Raciti, F. Rosenberger, Th. Rubehn, H. Sann, C. Schwarz, W. Seidei, V. Serfling

Faculty Publications

Multi-fragment decays of 129Xe, 197Au and 238U projectiles in collisions with Be, C, Al, Cu, In, Au and U targets at energies between View the MathML source and 1000 MeV have been studied with the ALADIN forward-spectrometer at SIS. By adding an array of 84 SiCsI(Tl) telescopes the solid-angle coverage of the setup was extended to θlab = 16°. This permitted the complete detection of fragments from the projectile-spectator source. The dominant feature of the systematic set of data is the Zbound universality that is obeyed by the fragment multiplicities and correlations. These observables are invariant with respect to the …

Design Of A Two-Chamber-No₂-Fluorescence-Cell, Volker Schmid

Dissertations and Theses

Nitrogen oxides control the photochemical production of ozone O₃ in the lower atmosphere and influence the concentration of the hydroxyl radical HO in the troposphere. As an important member of the nitrogen oxide family, NO₂ plays a significant role in serving as the only known source of ozone (through photolysis) in the lower atmosphere and as sink for HO via formation of nitric acid. Therefore, accurate measurements of nitrogen dioxide are essential for the understanding of the processes that determine the distribution of tropospheric ozone and for assessing the impact of human activity on the troposphere.

Although reliable and …

The Current Energy Situation: Summary Points, David W. Hafemeister, A. Brecher, A. Fainberg, R. Howes, R. Socolow, D. Bodansky, P. Craig, B. Hammer, S. Smith, E. Stechel

Physics

Energy problems are now being largely ignored, despite their continuing importance. The near-disappearance of energy from the U.S. public agenda is apparent in the scant attention given to energy topics by the media and by public figures. Some suggestions for governmental action were stimulated by the rise in gasoline prices in the Spring of 1996, but the matter was treated as a short-term anomaly -- not as a harbinger of more severe difficulties to come. This lack of long term concern is perhaps natural, because fuel supplies are generally ample and prices are still relatively low, with the real cost …

Noncentral Potentials And Spherical Harmonics Using Supersymmetry And Shape Invariance, Ranabir Dutt, Asim Gangopadhyaya, Uday P. Sukhatne

Physics: Faculty Publications and Other Works

It is shown that the operator methods of supersymmetric quantum mechanics and the concept of shape invariance can profitably be used to derive properties of spherical harmonics in a simple way. The same operator techniques can also be applied to several problems with noncentral vector and scalar potentials. As examples, we analyze the bound state spectra of an electron in a Coulomb plus an Aharonov – Bohm field and/or in the magnetic field of a Dirac monopole.