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Physical Sciences and Mathematics Commons

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2009

Portland State University

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Articles 31 - 60 of 116

Full-Text Articles in Physical Sciences and Mathematics

Interview With Caitlin Blethen, Growing Gardens, 2009 (Audio), Caitlin Blethen Jul 2009

Interview With Caitlin Blethen, Growing Gardens, 2009 (Audio), Caitlin Blethen

All Sustainability History Project Oral Histories

Interview of Caitlin Blethen by Kristin Milner at Growing Gardens Organization Portland, Oregon on July 29th, 2009.

The interview index is available for download.


Interview With Steve Cohen, Planning & Sustainable Development, 2009 (Audio), Steve Cohen Jul 2009

Interview With Steve Cohen, Planning & Sustainable Development, 2009 (Audio), Steve Cohen

All Sustainability History Project Oral Histories

Interview of Steve Cohen by Chris Stephens at Ecotrust Building, Portland, Oregon on July 28th, 2009.

The interview index is available for download.


Interview With Marissa Madrigal, Jeff Cogen Chief Of Staff, 2009 (Audio), Marissa Madrigal Jul 2009

Interview With Marissa Madrigal, Jeff Cogen Chief Of Staff, 2009 (Audio), Marissa Madrigal

All Sustainability History Project Oral Histories

Interview of Marissa Madrigal by Andrea Schons in Portland, Oregon on July 23rd, 2009.

The interview index is available for download.


Increasing The Reliability Of Ecological Models Using Modern Software Engineering Techniques, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Brendan C. Ward, David J. Mladenoff Jul 2009

Increasing The Reliability Of Ecological Models Using Modern Software Engineering Techniques, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Brendan C. Ward, David J. Mladenoff

Environmental Science and Management Faculty Publications and Presentations

Modern software development techniques are largely unknown to ecologists. Typically, ecological models and other software tools are developed for limited research purposes, and additional capabilities are added later, usually in an ad hoc manner. Modern software engineering techniques can substantially increase scientific rigor and confidence in ecological models and tools. These techniques have the potential to transform how ecological software is conceived and developed, improve precision, reduce errors, and increase scientific credibility. We describe our re-engineering of the forest landscape model LANDIS (LANdscape DIsturbance and Succession) to illustrate the advantages of using common software engineering practices.


Invasive Species Management Plan For Oswego Lake, Daniel Warren, Mark Sytsma Jul 2009

Invasive Species Management Plan For Oswego Lake, Daniel Warren, Mark Sytsma

Environmental Science and Management Professional Master's Project Reports

This Invasive Species Management Plan defines an overarching strategy for the Lake Oswego Corporation (LOC) to mitigate threats from invasive species to Oswego Lake. Invasive species pose a direct risk to recreational and aesthetic uses of the lake, critical LOC infrastructure, and ecological communities within the lake. The Plan is particularly concerned with two bivalve mollusks in the genus Dreissena: the zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena bugensis). These mussels grow in dense colonies that damage watercraft and underwater structures as well as displace native species. A recent scientific report found that …


Holism And Human History, Martin Zwick Jul 2009

Holism And Human History, Martin Zwick

Systems Science Faculty Publications and Presentations

We want and need the ‘whole story,’ but the whole story is difficult to tell. We can reduce the magnitude of the task by taking a cue from the title of the meeting, namely “Cosmos, Nature, Culture: A Transdisciplinary Conference.” The ‘whole story’ can be divided into three stories: the story of the unfolding of the universe (‘cosmos’), the story of the evolution of life (‘nature’), and the story of human history (‘culture’). This paper focuses on the third of these. Of course, human history is rooted in nature which is a manifestation of cosmos on our planet, but its …


Variational Theory Of Balance Systems, Serge Preston Jul 2009

Variational Theory Of Balance Systems, Serge Preston

Mathematics and Statistics Faculty Publications and Presentations

In this work we apply the Poincare-Cartan formalism of the Classical Field Theory to study the systems of balance equations (balance systems). We introduce the partial k-jet bundles of the configurational bundle and study their basic properties: partial Cartan structure, prolongation of vector fields, etc. A constitutive relation C of a balance system is realized as a mapping between a (partial) k-jet bundle and the extended dual bundle similar to the Legendre mapping of the Lagrangian Field Theory. Invariant (variational) form of the balance system corresponding to a constitutive relation C is studied. Special cases of balance systems -Lagrangian systems …


Comparison Of The Focal Properties Of Selected Magnetic And Electrostatic Lenses And Tests Of Their Theoretical Models, Luis Thomas Almarez Jun 2009

Comparison Of The Focal Properties Of Selected Magnetic And Electrostatic Lenses And Tests Of Their Theoretical Models, Luis Thomas Almarez

Dissertations and Theses

The main goal of the present research is to determine whether there is a significant difference between the aberrations of magnetic and electrostatic electron lenses when they are used in the same way. Comparison of the lenses was done in an electron-optical bench, set up to resemble a scanning electron microscope (SEM). Five different lenses, two magnetic and three electrostatic, were compared. Each group included two lenses with different lens-field lengths (pole-face spacing in magnetic lenses and interior length in electrostatic lenses). The lenses were used in turn to focus the electron beam into a demagnified image, or probe. The …


Development Of An Ambient Pressure Laser-Induced Fluorescence Instrument For Nitrogen Dioxide, Jeremy Parra, Linda Acha George Jun 2009

Development Of An Ambient Pressure Laser-Induced Fluorescence Instrument For Nitrogen Dioxide, Jeremy Parra, Linda Acha George

Environmental Science and Management Faculty Publications and Presentations

Concerns about the health effects of nitrogen dioxide (NO₂) and its role in forming deleterious atmospheric species have made it desirable to have low-cost, sensitive ambient measurements of NO₂. We have developed a continuous-wave laser-diode laser-induced fluorescence (LIF) system for NO₂ that operates at ambient pressure, thereby eliminating the need for an expensive pumping system. The current prototype system has achieved sensitivity several orders of magnitude beyond previous efforts at ambient pressure (limit of detection of 2 ppb, 60 s averaging time). Ambient measurements of NO₂ were made in Portland, Oregon using both the standard NO₂ chemiluminescence method and the …


Finite Sample Properties Of Minimum Kolmogorov-Smirnov Estimator And Maximum Likelihood Estimator For Right-Censored Data, Jerzy Wieczorek Jun 2009

Finite Sample Properties Of Minimum Kolmogorov-Smirnov Estimator And Maximum Likelihood Estimator For Right-Censored Data, Jerzy Wieczorek

Dissertations and Theses

MKSFitter computes minimum Kolmogorov-Smirnov estimators (MKSEs) for several different continuous univariate distributions, using an evolutionary optimization algorithm, and recommends the distribution and parameter estimates that best minimize the Kolmogorov-Smirnov (K-S) test statistic. We modify this tool by extending it to use the Kaplan-Meier estimate of the cumulative distribution function (CDF) for right-censored data. Using simulated data from the most commonly-used survival distributions, we demonstrate the tool's inability to consistently select the correct distribution type with right-censored data, even for large sample sizes and low censoring rates. We also compare this tool's estimates with the right-censored maximum likelihood estimator (MLE). While …


Operational Verification Of A Relativistic Program, Robert T. Bauer Jun 2009

Operational Verification Of A Relativistic Program, Robert T. Bauer

Computer Science Faculty Publications and Presentations

Engineering eorts to achieve scalable multiprocessor perfor- mance for concurrent reader-writer programs have resulted in a family of algorithms that are non-blocking and that tolerate interprocessor in- terference. Because these algorithms accept a unique frame of reference for each processor's accesses to memory, they typify a concurrent pro- gramming technique for shared memory multicore architectures called relativistic programmming.

Rigorous verification of these algorithms is not possible with existing semantic based approaches because the semantics under approximates multiprocessor behavior and the algorithms rely on abstruse interactions with the operating system that aren't reconciled with language seman- tics.

The Read-Copy Update (RCU) …


Interview With Ted Labbe, Depave, 2009 (Audio), Ted Labbe May 2009

Interview With Ted Labbe, Depave, 2009 (Audio), Ted Labbe

All Sustainability History Project Oral Histories

Interview of Ted Labbe by Chris Fogg in Portland, Oregon on May 31st, 2009.

The interview index is available for download.


Interview With Tom Patzkowski, Rebuilding Center, 2009 (Audio), Tom Patzkowski May 2009

Interview With Tom Patzkowski, Rebuilding Center, 2009 (Audio), Tom Patzkowski

All Sustainability History Project Oral Histories

Interview of Tom Patzkowski by Greg Peterson at the Rebuilding Center in Portland, Oregon on May 27th, 2009.

The interview index is available for download.


Interview With Ivy Dunlap, Bureau Of Environmental Services, 2009 (Audio), Ivy Dunlap May 2009

Interview With Ivy Dunlap, Bureau Of Environmental Services, 2009 (Audio), Ivy Dunlap

All Sustainability History Project Oral Histories

Interview of Ivy Dunlap by Kris Thomason at Portland State University on May 23rd, 2009.

The interview index is available for download.


Interview With Kirk Davis, Glumac International, 2009 (Audio), Kirk Davis May 2009

Interview With Kirk Davis, Glumac International, 2009 (Audio), Kirk Davis

All Sustainability History Project Oral Histories

Interview of Kirk Davis by Jay Fielding at Glumac International, Portland, Oregon on May 22nd, 2009.

The interview index is available for download.


Isotopic Signatures And Concentration Profiles Of Nitrous Oxide In A Rice-Based Ecosystem During The Drained Crop-Growing Season, Z. Q. Xiong, M. A. K. Khalil, G. Xing, Martha J. Shearer, Christopher Lee Butenhoff May 2009

Isotopic Signatures And Concentration Profiles Of Nitrous Oxide In A Rice-Based Ecosystem During The Drained Crop-Growing Season, Z. Q. Xiong, M. A. K. Khalil, G. Xing, Martha J. Shearer, Christopher Lee Butenhoff

Physics Faculty Publications and Presentations

The stable isotopic composition of nitrous oxide (N₂O) in agricultural soils can improve our understanding of the relative contributions of the main microbial processes (nitrification and denitrification) responsible for N₂O formation in soils, and can provide constraints for the atmospheric N2O budget. Here, we present soil profiles featuring N₂O concentrations and δ¹⁵N and δ¹⁸O values in N₂O over time, which permit the in situ identification of processes and sites of N₂O production in a rice-based ecosystem seeded with winter wheat. Our δ¹⁵N and δ¹⁸O soil profile values support the conclusion that denitrification is the dominant process behind N₂O production during …


Interview With Hilary Pfeifer, Art On Alberta, 2009 (Audio), Hilary Pfeifer May 2009

Interview With Hilary Pfeifer, Art On Alberta, 2009 (Audio), Hilary Pfeifer

All Sustainability History Project Oral Histories

Interview of Hilary Pfeifer by Franziska Davis at Portland State University on May 14th, 2009.

The interview index is available for download.


Electron Transport And Sensor Characteristics Of Tin Dioxide Based Nanocrystalline Materials, Allen Chaparadza May 2009

Electron Transport And Sensor Characteristics Of Tin Dioxide Based Nanocrystalline Materials, Allen Chaparadza

Dissertations and Theses

Wide band gap, transparent semiconductor Sn02 is an n-type conductor and is widely used as a sensor material as well as transparent electrode material e.g. in solar cells and flat panel displays. Recent discovery of p-type doping with Li has opened exciting possibilities in new classes of sensors and transparent nanoelectronic devices. Li-doping in SnO2 nanoparticles was explored through a gel-sol method of synthesis to examine the influence of reaction conditions such as pH, dopant concentration, and calcination temperature. The Li doping in nanoparticles was characterized using nuclear reaction analysis and the nanostructure with high-resolution electron transmission microscopy …


Active Site Chemistry Of The Nadph-Dependent:7-Cyano-7-Deazaguanine (Preq0) Nitrile Oxidoreductase, An Enzyme Involved In Queuosine Biosynthesis, Bobby Wai Keung Lee May 2009

Active Site Chemistry Of The Nadph-Dependent:7-Cyano-7-Deazaguanine (Preq0) Nitrile Oxidoreductase, An Enzyme Involved In Queuosine Biosynthesis, Bobby Wai Keung Lee

Dissertations and Theses

Queuosine (Q) is a modified nucleoside found at the wobble position of bacterial and eukaryotic transfer RNAs (tRNAs) that are specific for the amino acids tyrosine, histidine, aspartate and asparagine. A recently discovered enzyme in the biosynthetic pathway of Q, the NADPH-dependent 7-cyano-7-deazaguanine oxidoreductase (QueF), carries out the two-fold, four-electron reduction of Q precursor preQ0 to preQ1 and represents the first example of the enzymatic conversion of the nitrile functional group to an amine. Presented herein are kinetic, spectroscopic, mutational, biophysical, and isotope labeling studies directed at the elucidation of the chemical and kinetic mechanisms of this new class of …


Prediction Of Persistence Of Fertilizer-Derived Cadmium In Oregon Agricultural Soils Using Equilibrium Modeling And Fertilizer Release Kinetics, Fungai Mukome May 2009

Prediction Of Persistence Of Fertilizer-Derived Cadmium In Oregon Agricultural Soils Using Equilibrium Modeling And Fertilizer Release Kinetics, Fungai Mukome

Dissertations and Theses

Organic farming has become a multimillion dollar industry and while much emphasis is put on subsequent fertilizer inputs onto these fields, very little consideration is given to the prior fertilization activities of these soils. For a farm to be certified organic it means no harmful chemicals have been applied for at least three years.

The overall hypothesis tested by this research was that equilibrium adsorption models can adequately represent the behavior of fertilizer-derived cadmium in Oregon agricultural soils and that such model results can be easily incorporated into risk assessment models, transport study models and persistence studies for organic or …


Automated Crystal Phase And Orientation Mapping Of Nanocrystals In A Transmission Electron Microscope, Peter Moeck, Sergei Rouvimov, Edgar F. Rauch, Stavros Nicolopoulos May 2009

Automated Crystal Phase And Orientation Mapping Of Nanocrystals In A Transmission Electron Microscope, Peter Moeck, Sergei Rouvimov, Edgar F. Rauch, Stavros Nicolopoulos

Physics Faculty Publications and Presentations

An automated technique for the mapping of nanocrystal phases and orientations in a transmission electron microscope (TEM) is described. It is based on the projected reciprocal lattice geometry that is extracted from electron diffraction spot patterns. The required hardware allows for a scanning‐precession movement of the primary electron beam on the crystalline sample and can be interfaced to any newer or older TEM. The software that goes with this hardware is flexible in its intake of raw data so that it can also create orientation and phase maps of nanocrystal from high resolution TEM (HRTEM) images. When the nanocrystals possess …


The Design And Implementation Of A Safe, Lightweight Haskell Compiler, Timothy Jan Chevalier May 2009

The Design And Implementation Of A Safe, Lightweight Haskell Compiler, Timothy Jan Chevalier

Computer Science Faculty Publications and Presentations

Typed programming languages offer safety guarantees that help programmers write correct code, but typical language implementations offer no proof that source-level guarantees extend to executable code. Moreover, typical implementations link programs with unsafe runtime system (RTS) code. I present a compiler for the functional language Haskell that preserves some of the properties of Haskell’s type system. The soundness proof for the combination of the compiler and a verified RTS requires a proof that the compiler emits code that cooperates correctly with the RTS. In particular, the latter proof must address the boundary between the user program and the garbage collector. …


Quantum Multiplexers, Parrondo Games, And Proper Quantization, Faisal Shah Khan Apr 2009

Quantum Multiplexers, Parrondo Games, And Proper Quantization, Faisal Shah Khan

Dissertations and Theses

A quantum logic gate of particular interest to both electrical engineers and game theorists is the quantum multiplexer. This shared interest is due to the facts that an arbitrary quantum logic gate may be expressed, up to arbitrary accuracy, via a circuit consisting entirely of variations of the quantum multiplexer, and that certain one player games, the history dependent Parrondo games, can be quantized as games via a particular variation of the quantum multiplexer. However, to date all such quantizations have lacked a certain fundamental game theoretic property.

The main result in this dissertation is the development of quantizations of …


Quaternions, Octonions, And The Quantization Of Games, Aden Omar Ahmed Apr 2009

Quaternions, Octonions, And The Quantization Of Games, Aden Omar Ahmed

Dissertations and Theses

We present an effect on classical games that is obtained by replacing the notion of probability distribution with the notions of quantum superposition and measurement. Our particular focus will be on two and three player games where each player has precisely two pure strategic choices. Games in normal form are represented as "payoff" functions.

Game quantization requires the extension of these functions to much larger domains. The main result of this work is the co-ordinatization of these extended functions by either the quaternions or octonions in order to obtain computationally friendly versions of these functions. This computational capability is then …


Large-Scale Assembly Of Periodic Nanostructures With Metastable Square Lattices, Chih-Hung Sun, Wei-Lun Min, Nicholas C. Linn, Peng Jiang, Bin Jiang Apr 2009

Large-Scale Assembly Of Periodic Nanostructures With Metastable Square Lattices, Chih-Hung Sun, Wei-Lun Min, Nicholas C. Linn, Peng Jiang, Bin Jiang

Mathematics and Statistics Faculty Publications and Presentations

This article reports a simple and scalable spin-coating technique for assembling non-close-packed colloidal crystals with metastable square lattices over wafer-scale areas. The authors observe the alternate formation of hexagonal and square diffraction patterns when the thickness of the colloidal crystals is gradually reduced during spin coating. No prepatterned templates are needed to induce the formation of the resulting metastable crystals with square arrangement. This bottom-up technology also enables the large-scale production of a variety of squarely ordered nanostructures that are consistent with the industry-standard rectilinear coordinate system for simplified addressing and circuit interconnection. Broadband moth-eye antireflection gratings with square lattices …


Gravity Effects On Capillary Flows In Sharp Corners, Enrique Ramé, Mark M. Weislogel Apr 2009

Gravity Effects On Capillary Flows In Sharp Corners, Enrique Ramé, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

We analyze the effect of gravity on capillary flows in sharp corners. We consider gravity perpendicular and parallel to the channel axis. We analyze both steady and unsteady flows. In the steady analysis the main result is a closed form expression for the flow rate as a function of the two gravity components. Good agreement with steady experiments is offered as support of the model. The unsteady analysis is restricted to “small” values of the two gravity parameters and is accomplished using a similarity formulation. The similarity coefficients of the gravity corrections are fully determined by the coefficients of the …


Mangrove-Exported Nutrient Incorporation By Sessile Coral Reef Invertebrates, Elise F. Granek, Jana E. Compton, Donald L. Phillips Apr 2009

Mangrove-Exported Nutrient Incorporation By Sessile Coral Reef Invertebrates, Elise F. Granek, Jana E. Compton, Donald L. Phillips

Environmental Science and Management Faculty Publications and Presentations

Coastal mangrove forests were historically considered as a source of organic matter (OM) for adjacent marine systems due to high net primary production; yet recent research suggesting little uptake through the food web because of low nutritional quality, challenges the concept of trophic linkage between mangrove forests and coral reefs. To examine the importance of mangrove forests to coral reef nutrient availability, we examined sessile reef-forming invertebrate consumers including hard corals, sponges, a bivalve mollusc, polychaete annelid and tunicate, and potential sources of OM (decaying mangrove leaves, microalgae, macroalgae, and seagrass) in Bocas del Toro, Panama. Using stable isotope analyses …


A Framework For Superimposed Applications : Techniques To Represent, Access, Transform, And Interchange Bi-Level Information, Sudarshan Srivivasa Murthy Mar 2009

A Framework For Superimposed Applications : Techniques To Represent, Access, Transform, And Interchange Bi-Level Information, Sudarshan Srivivasa Murthy

Dissertations and Theses

Superimposed applications (SAs) superimpose (that is, overlay) new information and structures (such as annotations) on parts (such as sub-documents) of existing base information (BI). In this setting, SA developers and users work with bi-level information, a combination of the superimposed information and the referenced BI parts.

We have designed a framework to assist SAs in the following bi-level-information-management activities: representation, access, transformation, and interchange. This framework defines the abstraction context agent to activate any BI part and to retrieve information from the context of the part. It includes means to represent and access bi-level information in a conceptual model (the …


Interview With Lynne Nelson, Oregon Mortuary & Cemetery Board, 2009 (Audio), Lynne Nelson Mar 2009

Interview With Lynne Nelson, Oregon Mortuary & Cemetery Board, 2009 (Audio), Lynne Nelson

All Sustainability History Project Oral Histories

Interview of Lynne Nelson by Daniel Donovan in Portland, Oregon on March 9th, 2009.

The interview index is available for download.


Interview With Daniel Hilton, Mt. Hood Community College, 2009 (Audio), Daniel Hilton Mar 2009

Interview With Daniel Hilton, Mt. Hood Community College, 2009 (Audio), Daniel Hilton

All Sustainability History Project Oral Histories

Interview of Daniel Hilton by Cory Minick at Mt. Hood Community College on March 5th, 2009.

The interview index is available for download.