Physical Sciences and Mathematics Commons^™

Friction-Weighted Self-Consistent Effective Binary Diffusion Approximation, John D. Ramshaw, C. H. Chang

Physics Faculty Publications and Presentations

The self-consistent effective binary diffusion (SCEBD) approximation for multicomponent diffusion in gas mixtures is reconsidered and reformulated. The new formulation is based on the fact that a suitable rearrangement of the Stefan-Maxwell equations provides an exact expression for the complementary mean velocity a_i for species i as a weighted average of the velocities of all the other species. The coefficients in a_i are normalized friction coefficients which are simply related to the true binary diffusion coefficients. A simple factorized bilinear approximation to the friction coefficients then yields approximate species diffusion fluxes identical in form to those of a …

Leaner Environmental Policies For Agriculture, David E. Ervin, Elisabeth A. Graffy

Economics Faculty Publications and Presentations

Farmers and ranchers face a most troubling dilemma. Complex political forces have mapped two quite different paths to environmental management-a rollback of federal regulations or a buildup of traditional subsidies. In the words of a famous modern philosopher, "When you reach a fork in the road, take it!" But either choice poses risk for the industry and will not likely ameliorate nettlesome environmental problems. A third path could help the industry maintain competitiveness and meet environmental challenges. This path uses me latest science to identify agroenvironmental problems and emphasizes economically attractive technology to sustain environmental improvements.

Geometrical Modeling Of Material Aging, Alexander Chudnovsky, Serge Preston

Mathematics and Statistics Faculty Publications and Presentations

Material aging is understood as changes of material properties with time. The aging is usually observed as an improvement of some properties and a deterioration of others. For example an increase of rigidity and strength and reduction in toughness with time are commonly observed in engineering materials. In an attempt to model aging phenomena on a continuum (macroscopical) level one faces three major tasks. The first is to identify an adequate age parameter that represents, on a macroscopic scale, the micro and sub microscopical features, underlying the aging phenomena such as nucleation, growth and coalescence of microdefects, physico-chemical transformations etc. …

Embedded Particle Computation In Evolved Cellular Automata, Wim Hordijk, James P. Crutchfield, Melanie Mitchell

Computer Science Faculty Publications and Presentations

In our work we are studying how genetic algorithms (GAs) can evolve cellular automata (CAs) to perform computations that require global coordination. The evolving cellular automata" framework is an idealized means for studying how evolution (natural or computational) can create systems that perform emergent computation, in which the actions of simple components with local information and communication give rise to coordinated global information processing [3].

In previous work [4, 5], we analyzed the process by which a genetic algorithm designed CAs to perform particular tasks. In this paper we focus on how these CAs implement the emergent computational strategies for …

On Non-Holonomic Second-Order Connections With Applications To Continua With Microstructure, Marek Elźanowski, Serge Preston

Mathematics and Statistics Faculty Publications and Presentations

Motivated by the theory of uniform elastic structures we try to determine the conditions for the local flatness of locally integrable connections on non-holonomic frame bundles of order 2. Utilizing the results of Yuen as well as our results for the holonomic case, we show that the locally integrable non-holonomic 2-connection is locally flat if, and only if, its projection to the bundle of linear frames is symmetric and the so-called inhomogeneity tensor vanishes. In the last section of this short paper we show how these results can be interpreted in the framework of the theory of uniformity of simple …

Final Environmental Impact Statement For The Bal'diyaka Interpretive Center At Gregory Point On The Oregon Coast In Coos County, Joseph A. Maser

Environmental Science and Management Faculty Publications and Presentations

The Confederated Tribes of Coos, Lower Umpqua and Siuslaw Indians, in partnership with the Coos Bay District of the Bureau of Land Management (BLM) are proposing to construct and operate an interpretive center near or on the South Coast of Oregon, near Coos Bay. The Bal'diyaka Interpretive Center is envisioned to contain a 51,000 square foot main building, a recreated coastal Indian village, an ethnobotanical interpretive trail, vehicular circulation and parking, and utilities infrastructure.

This Environmental Impact Statement analyzes four alternatives for this proposed interpretive center. The proposed action of the BLM would locate the Bal'diyaka Interpretive Center on Gregory …

Control Uniqueness In Reconstructability Analysis, Martin Zwick

Systems Science Faculty Publications and Presentations

When the reconstructability analysis of a directed system yields a structure in which a generated variable appears in more than one subsystem, information from all of the subsystems can be used in modeling the relationship between generating and generated variables. The conceptualization and procedure proposed here is discussed in relation to Klir's concept of control uniqueness.

Captive Environmental Influences On Behavior In Zoo Drills And Mandrills (Mandrillus), A Threatened Genus Of Primate, Erik Terdal

Dissertations and Theses

Drills (Mandrillus leucophaeus) are an endangered species of African monkey (Cercopithecidae), and their sole congener the mandrill (Mandrillus sphinx) is vulnerable to extinction. Both species are threatened in the wild by deforestation and hunting.

Drills have a poor record of captive reproduction. Many individuals appear to have behavioral deficiencies which interfere with reproduction. Thus, the zoo population of drills does not serve as a “hedge” against the species’ total extinction: drills are endangered in captivity as well as in the wild. Mandrills, by contrast, reproduce well in captivity. Information on the behavior of mandrills in captivity may help zoo managers …

A Policy-Independent Secure X Server, Kirk Joseph Bittler

Dissertations and Theses

This thesis demonstrates that a secure X system can be designed and implemented to be independent of a particular security policy. The advantages and costs of a separation of security policy and enforcement are examined by developing a large scale application, the DX windowing system, on a DTOS platform. DTOS is a high assurance operating system that isolates policy decisions in a Security Server. A security conscious process, such as DX, eliminates policy considerations from the code. The process instead consults the Security Server and enforces the decisions that server derives from the policy. The DX architecture is described and …

Mechanisms Of Pentachlorophenol Induced Charge Transport In Lipid Membranes, William Charles Brown

Dissertations and Theses

Pentachlorophenol (PCP) is one of the prominent environmental pollutant that has penetrated into food chain and is present in humans. Health concerns have been raised since daily intake of PCP by the US population is estimated to be 16-19 µg. PCP facilitates dissipation of electrochemical potential gradients of hydrogen ions across energy transducing membranes, which are the energy sources for the conversion of adenosine diphosphate into adenosine triphosphate. Closely linked to these dissipative effects is the development of electrical conductivity in lipid membranes, induced by the presence of PCP. Three modes of PCP - induced membrane electrical conductivity were theoretically …

Single Molecule Emission Characteristics In Near-Field Microscopy, Randy X. Bian, Robert C. Dunn, X. Sunney Xie, P.T. Leung

Physics Faculty Publications and Presentations

In near-field scanning optical microscopy (NSOM), the measured fluorescence lifetime of a single dye molecule can be shortened or lengthened, sensitively dependent on the relative position between the molecule and aluminum coated fiber tip. The modified lifetimes and other emission characteristics are simulated by solving Maxwell equations with the finite-difference time-domain (FDTD) method. The 2D computation reveals insight into the lifetime behaviors and provides guidance for nonperturbative spectroscopic measurements with NSOM. This new methodology is capable of predicting molecular emission properties in front of a metal/dielectric interface of arbitrary geometry.

Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu

Computer Science Faculty Publications and Presentations

This paper describes problems and solutions for delivering real-time, multi-media presentations across the Internet. A key characteristic of presentations of continuous media datatypes, such as digital video and audio, is their need for predictable real-time data delivery. For example, an NTSC quality video presentation requires video frames to be displayed every 1/30th of a second. Variations in this display rate can be observable as stalls or glitches in the video stream and reduce the quality of the presentation [6]. Delivering such presentations across the Internet is difficult because highly variable band- width and latency make it difficult to predict the …

Complexity Properties Of The Cellular Automaton Game Of Life, Andreas Rechtsteiner

Dissertations and Theses

The Game of Life is probably the most famous cellular automaton. Life shows all the characteristics of Wolfram's complex Class IV cellular automata: long-lived transients, static and propagating local structures, and the ability to support universal computation.

We examine in this thesis questions about the geometry and criticality of Life. We find that Life has two different regimes with different dimensionalities. In the small scale regime Life shows a fractal dimensionality with D_s = 0.658 and in the large scale regime D₁ = 2.0, suggesting that the objects of Life are randomly distributed. We find that Life …

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Customizable Operating Systems, Jonathan Walpole, Crispin Cowan, Andrew P. Black, Jon Inouye, Calton Pu, Shanwei Cen

Computer Science Faculty Publications and Presentations

A customizable operating system is one that can adapt to improve its functionality or performance. The need for customizable and application-specific operating systems has been recognized for many years, but they have yet to appear in the commercial market. This paper explores the notion of operating system customizability and examines the limits of existing approaches. The paper begins by surveying system structuring approaches for the safe and efficient execution of customizable operating systems. Then it discusses the burden that existing approaches impose on application software, and explores techniques for reducing this burden. Finally, support for customizability in the Synthetix project …

Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

The bandwidth limitations of multimedia systems force tradeoffs between presentation data fidelity and real-time performance. For example, digital video is commonly encoded with lossy compression to reduce bandwidth and frames may be skipped during playback to maintain synchronization. These tradeoffs depend on device performance and physical data representations that are hidden by a database system. If a multimedia database is to support digital video and other continuous media data types, we argue that the database should provide a Quality of Service (QOS) interface to allow application control of presentation timing and information loss tradeoffs.

This paper proposes a data model …

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Evaluable Functions In The GöDel Programming Language: Parsing And Representing Rewrite Rules, Janet Vorvick

Dissertations and Theses

The integration of a functional component into a logic language extends the expressive power of the language. One logic language which would benefit from such an extension is Gödel, a prototypical language at the leading edge of the research in logic programming. We present a modification of the Gödel parser which enables the parsing of evaluable functions in Gödel. As the first part of an extended Gödel, the parser produces output similar to the output from the original Gödel parser, ensuring that Gödel modules are properly handled by the extended-Gödel parser. Parser output is structured to simplify, as much as …

Geochemistry Of The Boring Lava Along The West Side Of The Tualatin Mountains And Of Sediments From Drill Holes In The Portland And Tualatin Basins, Portland, Oregon, Michelle Lynn Barnes

Dissertations and Theses

Instrumental Neutron Activation Analysis (INAA) was used to identify geochemical groups in Boring Lava along the west side of the Tualatin Mountains, and in sediments of the Portland and Tualatin basins. Samples of Boring Lava were obtained from TriMet drill core collected during planning of the tunnel alignment for the Westside Light Rail line. Additional samples of Boring Lava were collected from outcrops along the west side of the Tualatin Mountains. Samples of sediment from the Tualatin and Portland basins were obtained from drill core collected during an Oregon Department of Geology and Mineral Industries (DOGAMI) Earthquake Hazards Mapping project. …

Electrostatic Interactions At Membrane-Water Interfaces And Distribution Of 2, 4, 6-Trichlorophenol In A Membrane Model System, Isolde Sieder

Dissertations and Theses

It is generally accepted that biological membranes consist of a lipid bilayer matrix with proteins incorporated into the lipid bilayer. Typically, these membranes are negatively charged due to the presence of negatively charged lipids in the bilayer as well as negatively charged molecular groups on proteins. Biologically active molecules, such as environmental pollutants, enter the membrane from the aqueous phase by adsorption or partitioning into the lipid bilayer. The thesis consists of two parts. Part I is a computational study of spatial distribution of electric potential in the aqueous portion of the membrane-water interface using two models of charge distribution: …

An Unbalanced Debate. Review Of: Scarcity Or Abundance: A Debate On The Environment By Norman Myers And Julian Simon, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

Book Review of Scarcity or Abundance? A Debate on the Environment by Norman Myers and Julian Simon

Doubled Co2 Experiments With The Global Change Research Center Two-Dimensional Statistical Dynamical Climate Model, R. M. Mackay, M. A. K. Khalil

Physics Faculty Publications and Presentations

The zonally averaged response of the Global Change Research Center two-dimensional statistical dynamical climate model (GCRC 2-D SDCM) to a doubling of atmospheric carbon dioxide (350 parts per million by volume (ppmv) to 700 ppmv) is reported. The model solves the two-dimensional primitive equations in finite difference form (mass continuity, Newton's second law, and the first law of thermodynamics) for the prognostic variables: zonal mean density, zonal mean zonal velocity, zonal mean meridional velocity, and zonal mean temperature on a grid that has 18 nodes in latitude and 9 vertical nodes (plus the surface). The equation of state, p=rhoRT, and …

Intercomparison Of Local Hydroxyl Measurements By Radiocarbon And Fage Techniques, Malcolm J. Campbell, Brad D. Hall, John C. Sheppard, Philip L. Utley, Robert J. O'Brien, Thomas M. Hard, Linda Acha George

Environmental Science and Management Faculty Publications and Presentations

A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere at the site is believed to contain low levels of anthropogenic pollution. The instruments' inlets were located at the same height (3.5 m) above the ground and were separated by 10 m along a line normal to the prevailing wind. Readings of the FAGE3 and radiocarbon instruments showed a high correlation (r² = 0.74) despite HO concentrations that were frequently near the detection limit of the instruments. An unweighted least squares regression shows …

Ionization-Excitation Of Helium By Fast Charged Particles, L. Nagy, J. Wang, Jack C. Straton, James H. Mcguire

Physics Faculty Publications and Presentations

Probabilities and cross sections for ionization plus excitation in helium produced by fast heavy-particle impact have been evaluated. In these calculations, contributions from shake-off, time ordering, and independent interactions of the frozen-target electrons with the projectile are included. A comparison is made to recent experimental observations for the ratio of excitation-ionization to single-ionization total cross sections. A comparison is also made to calculations of excitation-ionization by fast electron impact.

Origins And Effects Of Thermal Processes On Near-Field Optical Probes, Andres H. La Rosa, B. I. Yakobson, H. D. Hallen

Physics Faculty Publications and Presentations

An aluminum-coated tapered fiber probe, as used in near-field scanning optical microscopy (NSOM), is heated by the light coupled into it. This can destroy the probe or may modify the sample, which can be problematic or used as a tool. To study these thermal effects, we couple modulated visible light of various power through probes. Simultaneously coupled infrared light senses the thermal effects. We report their magnitude, their spatial and temporal scales, and real-time probe damage observations.Amodel describes the experimental data, the mechanisms for induced IR variation, and their relative importance.

Origins Of Effective Charge Of Multivalent Ions At A Membrane/Water Interface And Distribution Of 2,3,4,5-Tetrachlorophenol In A Membrane Model System, Piet O. Schmidt

Dissertations and Theses

Biological cells and subcellular organelles are surrounded by membranes to form compartments performing specialized functions. Adsorption or partitioning of biologically active compounds into the membrane is the first step in the process of modification of cell function. This work is concerned with the problem of distribution of charged molecules between water and electrically charged membrane surface and between water and octanol. Part I of this thesis is focused on the electrostatic interactions taking place between charges on the membrane and ions present in the aqueous region of the membrane/water interface. The objective was to explore theoretically the origin of anomalous …

The Interaction Between A Thiol Specific Probe (Opa) And The Single Channel Characteristics Of The Reconstituted Ca++ Release Protein From Skeletal Muscle Sarcoplasmic Reticulum, Alexander Braun

Dissertations and Theses

One advantage of higher life-forms over less developed organisms is their ability to respond to signals from their environment with motion. This requires highly specialized contractile cells and a whole locomotion apparatus. In vertebrates, the cells responsible for movement are the skeletal muscle cells. They receive signals from the autonomic nervous system in the form of an action potential, and they contract in an appropriate manner. Calcium is a vital intracellular passenger whose role in muscular function is to initiate contraction. It is released via specific channel proteins from an internal Ca++ store, the sarcoplasmic reticulum, and triggers muscular contraction, …

Synthesis And Characterization Of Novel Fluorine Containing Alkylsulfonyls And Sulfonates : Fluorinated Sulfonyl Methanes And Derivatives, Nelson R. Holcomb

Dissertations and Theses

A series of salts of the strong fluorocarbon acid bis(trifluoromethylsulfonyl)methane were made: (CF3S02 ) 2CHK, (CF3S02 ) 2CHLi, [ (CF3S02 ) 2CH] 2Ca, [ (CF3S02 ) 2CH] 2Hg, (CF3S02 ) 2CHAg, [ (CF3S02 ) 2CH] 3La. Their reactivity and use as organic intermediates were investigated. The salts were made from their corresponding carbonates, oxides, or hydrides. The reaction times for the salts is generally short, however the purification process was laborious, involving recrystallization from organic solvents and drying under vacuum. The lithium salt is being evaluated as a solid state battery electrolyte. Derivatives of bis(trifluoromethylsulfonyl)methane were made by using the …

O-Phthalaldehyde Modification Of Sarcoplasmic Reticulum Calcium Release, Steffen Koehler

Dissertations and Theses

Muscle contraction is a phenomena which fascinated already the ancient Greeks. People have long sought to understand the mechanism of muscle contraction. Today we know that in order for muscle to contract, an action potential propagates from the nerve cell to the muscle cell. Upon arriving at the muscle cell, via a mechanism called Excitation- Contraction (E-C) coupling, Ca2 + is released from an intracellular membrane system, the sarcoplasmic reticulum (SR), into the intracellular fluid. The increase of intracellular Ca2 + initiates the interaction between the contractile units which results in force development and tension. The least well understood step …

Weakest Pre-Condition And Data Flow Testing, Griffin David Mcclellan

Dissertations and Theses

Current data flow testing criteria cannot be applied to test array elements for two reasons: 1. The criteria are defined in terms of graph theory which is insufficiently expressive to investigate array elements. 2. Identifying input data which test a specified array element is an unsolvable problem. We solve the first problem by redefining the criteria without graph theory. We address the second problem with the invention of the wp_du method, which is based on Dijkstra's weakest pre-condition formalism. This method accomplishes the following: Given a program, a def-use pair and a variable (which can be an array element), the …