Digital Commons Network^™

A Novel Approach To Flow And Sediment Transport Estimation In Estuaries And Bays, Hamed Moftakhari Rostamkhani

Dissertations and Theses

Reliable estimates of river discharge and sediment transport to the ocean from large tidal rivers are vital for water resources management, efficient river and harbor management, navigational purposes, and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, hydrological and sedimentological records are typically too short to adequately characterize long-term (decadal) trends. Also, uncertainties associated with observation and calibration of hydrological models suggest a need for more accurate methods based on longer records of hydrodynamic parameters (e.g. tides). Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave …

Intersections Of Critical Systems Thinking And Community Based Participatory Research In Developing A Web Site For Autistic Adults, Dora Madeline Raymaker

Dissertations and Theses

People with disabilities, including those on the autism spectrum, comprise the world's largest minority and experience significant inequities in Internet use. Existing standards for accessible web sites are necessary but not sufficient without the direct engagement of end users in identifying access needs. Yet little is known about methods for effective engagement, and there are no systematically derived Web accessibility guidelines for autistic end users. Here I explore a hybrid approach to direct engagement using critical systems thinking (CST) and community based participatory research (CBPR) during the co-development of a healthcare-focused web site by the Academic Autism Spectrum Partnership in …

Aberration Corrected Photoemission Electron Microscopy With Photonics Applications, Joseph P. S. Fitzgerald

Dissertations and Theses

Photoemission electron microscopy (PEEM) uses photoelectrons excited from material surfaces by incident photons to probe the interaction of light with surfaces with nanometer-scale resolution. The point resolution of PEEM images is strongly limited by spherical and chromatic aberration. Image aberrations primarily originate from the acceleration of photoelectrons and imaging with the objective lens and vary strongly in magnitude with specimen emission characteristics. Spherical and chromatic aberration can be corrected with an electrostatic mirror, and here I develop a triode mirror with hyperbolic geometry that has two adjacent, field-adjustable regions. I present analytic and numerical models of the mirror and show …

Modifications To A Cavity Ringdown Spectrometer To Improve Data Acquisition Rates, Gregory Alan Bostrom

Dissertations and Theses

Cavity ringdown spectroscopy (CRDS) makes use of light retention in an optical cavity to enhance the sensitivity to absorption or extinction of light from a sample inside the cavity. When light entering the cavity is stopped, the output is an exponential decay with a decay constant that can be used to determine the quantity of the analyte if the extinction or absorption coefficient is known. The precision of the CRDS is dependent on the rate at which the system it acquires and processes ringdowns, assuming randomly distributed errors. We have demonstrated a CRDS system with a ringdown acquisition rate of …

Leveraging Contextual Relationships Between Objects For Localization, Clinton Leif Olson

Dissertations and Theses

Object localization is currently an active area of research in computer vision. The object localization task is to identify all locations of an object class within an image by drawing a bounding box around objects that are instances of that class. Object locations are typically found by computing a classification score over a small window at multiple locations in the image, based on some chosen criteria, and choosing the highest scoring windows as the object bounding-boxes. Localization methods vary widely, but there is a growing trend towards methods that are able to make localization more accurate and efficient through the …

Who Is At The Forest Restoration Table? Final Report On The Blue Mountains Forest Stewardship Network, Phase 1, Rebecca J. Mclain, Kirsten Wright, Lee Cerveny

Institute for Sustainable Solutions Publications and Presentations

Forest collaboratives have emerged throughout the western U.S. as a governance model to address complex ecological challenges that occur at the landscape scale across multiple landownerships and jurisdictional boundaries. Collaborative groups typically involve multiple parties with diverse interests working together to address complex management challenges. Collaboratives often provide input on or make recommendations about public lands actions and decisions. The Blues Stewardship Project was developed to better understand the size, composition, participation, and diversity of forest collaboratives and to identify organizations that may not currently be represented at the collaborative ‘table.’

The study focuses on five collaborative groups in the …

Delay Line As A Chemical Reaction Network, Josh Moles, Peter Banda, Christof Teuscher

Computer Science Faculty Publications and Presentations

Chemistry as an unconventional computing medium presently lacks a systematic approach to gather, store, and sort data over time. To build more complicated systems in chemistries, the ability to look at data in the past would be a valuable tool to perform complex calculations. In this paper we present the first implementation of a chemical delay line providing information storage in a chemistry that can reliably capture information over an extended period of time. The delay line is capable of parallel operations in a single instruction, multiple data (SIMD) fashion.

Using Michaelis-Menten kinetics, we describe the chemical delay line implementation …

Oregon Lake Watch, 2014 Annual Report, Meredith Jordan, Rich Miller, Angela L. Strecker

Center for Lakes and Reservoirs Publications and Presentations

The Oregon Lake Watch (OLW) volunteer monitoring program is now in its second year of operation, continuing its focus on early detection of aquatic invasive species (AIS), with a secondary focus on lake water quality. The aquatic invasive species chosen as Watch List priorities for the OLW are based on the Oregon Department of Agriculture’s Noxious Weed List (Oregon Department of Agriculture Noxious Weed Control Program 2014) as well as professional judgement (more information can be found in Oregon Lake Watch Final Report 2014). This report summarizes the data collected by 15 of 24 OLW volunteers over 2014, across 110 …

Comparison Between Observed And Model-Simulated Atmospheric Circulationpatterns Associated With Extreme Temperature Days Over North Americausing Cmip5 Historical Simulations, Paul C. Loikith, Anthony J. Broccoli

Geography Faculty Publications and Presentations

Circulation patterns associated with extreme temperature days over North America, as simulated by a suite of climate models, are compared with those obtained from observations. The authors analyze 17 coupled atmosphere–ocean general circulation models contributing to the fifth phase of the Coupled Model Intercomparison Project. Circulation patterns are defined as composites of anomalies in sea level pressure and 500-hPa geopotential height concurrent with days in the tails of temperature distribution. Several metrics used to systematically describe circulation patterns associated with extreme temperature days are applied to both the observed and model-simulated data. Additionally, self-organizing maps are employed as a means …

Assessing Usual Care In Clinical Trials, Judith A. Erlen, Lisa K. Tamres, Nancy Reynolds, Carol E. Golin, Marc I. Rosen, Robert H. Remien, Julie W. Banderas, Neil Schneiderman, Glenn Wagner, David Bangsberg, Honghu Liu

OHSU-PSU School of Public Health Faculty Publications and Presentations

Researchers designing clinical trials often specify usual care received by participants as the control condition expecting that all participants receive usual care regardless of group assignment. The assumption is that the groups in the study are affected similarly. We describe the assessment of usual care within the 16 studies in MACH 14, a multi-site collaboration on adherence to antiretroviral therapy. Only five of the studies in MACH 14 assessed usual care. Assessment protocols varied as did the timing and frequency of assessments. All usual care assessments addressed patient education focused on HIV, HIV medications, and medication adherence. Our findings support …

Retirement Security In Oregon, Jeff Renfro, Marisol Cáceres, Peter Hulseman

Northwest Economic Research Center Publications and Reports

By expanding access to retirement savings plans, a state-sponsored program for workers should increase the overall level of participation, and, ultimately, increase retirement fund income. The over 400,000 new enrollees estimated by this study suggests that these programs can have large impacts.

Zebra And Quagga Mussel Early-Detection Monitoring In High Risk Oregon Waters 2014, Steve W. Wells, Mark D. Sytsma

Center for Lakes and Reservoirs Publications and Presentations

Zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively) were not detected by Oregon Department of Fish and Wildlife (ODFW) and Portland State University (PSU) during their early detection sampling in Oregon water bodies during 2014. Six high-risk Oregon water bodies were sampled for planktonic larvae and adult mussels during the August to September period. A total of 37 plankton samples were collected and over 520,000 liters of reservoir/lake water were filtered through 64-μm mesh nets during plankton sample collection. The greatest sampling effort occurred in Emigrant Lake, Lake Billy Chinook, and Prineville Reservoir but sampling also occurred …

Tracking Of Rhythmical Biomedical Signals Using The Maximum A Posteriori Adaptive Marginalized Particle Filter, Sunghan Kim, Lars Andreas Holmstrom, James Mcnames

Electrical and Computer Engineering Faculty Publications and Presentations

Biomedical signals are often rhythmical and their morphologies change slowly over time. Arterial blood pressure and electrocardiogram signals are good examples with such property. It is of great interest to extract clinically useful information such as the instantaneous frequency (i.e. heart rate) and morphological changes (e.g. pulse pressure variation) from these signals. Conventional filtering methods such as the Kalman filter are not suitable for estimating the instantaneous frequency of quasiperiodic signals due to the non-Gaussian multi-modal property of its posterior distribution. One possible alternative is particle filters that are increasingly used for nonlinear systems and non-Gaussian posterior state distributions. However, …

Core Evolution Driven By Mantle Global Circulation, Peter Olson, Renaud Deguen, Maxwell L. Rudolph, Shijie Zhong

Geology Faculty Publications and Presentations

Reconstructions of the Phanerozoic history of mantle global circulation that include past plate motions are used to constrain the thermochemical evolution of the core. According to our mantle global circulation models, the present-day global average heat flux at the core-mantle boundary lies in the range 80-90 mW.m^-2, with peak-to-peak, long wavelength lateral variations up to 100 mW.m^-2 associated with compositional and thermal heterogeneity in the D”-layer. For core thermal conductivity in the range k=100-130 W.m^-1.K^-1 we infer that the present-day outer core is thermally unstable beneath the high seismic velocity regions in the …

Examining Edd Dissertations In Practice: The Carnegie Project On The Education Doctorate, Valerie A. Storey, Micki M. Caskey, Kristina A. Hesbol, James E. Marshall, Bryan D. Maughan, Amy Wells Dolan

Education Faculty Publications and Presentations

In 2007, 25 colleges and schools of education (Phase I) came together under the aegis of the Carnegie Project on the Education Doctorate (CPED) to transform doctoral education for education practitioners. A challenging aspect of the reform of the educational doctorate is the role and design of the dissertation or Dissertation in Practice. In response to consortium concerns, members of the CPED Dissertation in Practice Awards Committee conducted this action research study to examine the format and design of Dissertations in Practice submitted by (re) designed programs. Data were gathered with an online survey, interviews, analyses of 25 Dissertations in …

Energy Efficiency And Conservation Attitudes: An Exploration Of A Landscape Of Choices, Mersiha Spahic Mcclaren

Dissertations and Theses

This study explored energy-related attitudes and energy-saving behaviors that are no- or low-cost and relatively simple to perform. This study relied on two data sources: a longitudinal but cross-sectional survey of 4,102 U.S. residents (five biennial waves of this survey were conducted from 2002 to 2010) and a 2010 cross-sectional survey of 2,000 California residents. These two surveys contained data on two no- and low-cost behaviors: changing thermostat setting to save energy (no-cost behavior) and CFL installation behavior (low-cost behavior). In terms of attitudes, two attitudinal measures emerged from these data following a Cronbach's alpha and Confirmatory Factor Analysis (CFA): …

Reducing Student Costs: A Report On Textbooks And Course Materials, Marilyn K. Moody, Shadi Alkhaledi, Chelsey Weinmann, Kathleen M. Steppe, Jill Emery, Kimberly D. Pendell, Joel M. Bettridge, Karen Bjork, Emily Ford, Vincent Schreck, Berrin Erdogan, Gerardo Lafferriere, Ralf Widenhorn

Reducing Student Costs Initiative

"Reducing Student Costs: A Report on Textbooks and Course Materials" is a report to the Portland State University community. It was prepared by the Reduce Student Costs Task Force appointed by Bob Liebman, Presiding Officer, Portland State University Faculty Senate; Eric Noll, President of Associated Students of Portland State University (ASPSU); and Sona K. Andrews, Provost and Vice President for Academic Affairs (OAA).

Modeling Predator Habitat To Enhance Reintroduction Planning, Shiloh Michael Halsey, William J. Zielinski, Robert M. Scheller

Environmental Science and Management Faculty Publications and Presentations

Context

The success of species reintroduction often depends on predation risk and spatial estimates of predator habitat. The fisher (Pekania pennanti) is a species of conservation concern and populations in the western United States have declined substantially in the last century. Reintroduction plans are underway, but the ability of the species to establish a selfsustaining population is affected by predation from its primary predator, the bobcat (Lynx rufus).

Objectives

To develop a habitat model that incorporates both habitat of the focal species and the spatial patterning of predator habitat. To locate areas of densely aggregated habitat that would be suitable …

Beyond The Angle Of Repose: A Review And Synthesis Of Landslide Processes In Response To Rapid Uplift, Eel River, Northern Eel River, Northern California, Joshua J. Roering, Benjamin H. Mackey, Alexander L. Handwerger, Adam M. Booth, David A. Schmidt, Georgina L. Bennett, Corina Cerovski-Darriau

Geology Faculty Publications and Presentations

In mountainous settings, increases in rock uplift are often followed by a commensurate uptick in denudation as rivers incise and steepen hillslopes, making them increasingly prone to landsliding as slope angles approach a limiting value. For decades, the threshold slope model has been invoked to account for landslide-driven increases in sediment flux that limit topographic relief, but the manner by which slope failures organize themselves spatially and temporally in order for erosion to keep pace with rock uplift has not been well documented. Here, we review past work and present new findings from remote sensing, cosmogenic adionuclides, suspended sediment records, …

Bubble Mobility In Mud And Magmatic Volcanoes, Aaron Tran, Maxwell L. Rudolph, Michael Manga

Geology Faculty Publications and Presentations

The rheology of particle-laden fluids with a yield stress, such as mud or crystal-rich magmas, controls the mobility of bubbles, both the size needed to overcome the yield stress and their rise speed. We experimentally measured the velocities of bubbles and rigid spheres in mud sampled from the Davis-Schrimpf mud volcanoes adjacent to the Salton Sea, Southern California. Combined with previous measurements in the polymer gel Carbopol, we obtained an empirical model for the drag coefficient and bounded the conditions under which bubbles overcome the yield stress. Yield stresses typical of mud and basaltic magmas with sub-mm particles can immobilize …

On The Estimation Of Volumes Of Roadways: An Investigation Of Stop-Controlled Minor Legs, Joel Stephen Barnett

Dissertations and Theses

This effort seeks to answer the question; can a transferable model be developed from easily obtainable, publicly available land-use, census, roadway, and network data for the use in safety performance functions? 474 stop-controlled minor legs were used as the training data set using ordinary least squares regression. A best-fit model of maximum independent variables, n=12 was chosen using an exhaustive approach using Mallow's Cp to select the model with least bias in the predictors. The results of the analysis revealed that the combination of variables from Washington, Ohio, and North Carolina did not have a strong relationship. The best-fit model …

Current State Of Strain In The Central Cascadia Margin Derived From Changes In Distance Between Gps Stations, Kenneth M. Cruikshank, Curt D. Peterson

Geology Faculty Publications and Presentations

Using continuously operating Global Positioning Stations in the Pacific Northwest of the United States, over 100 station-station baseline length changes were determined along seven West-East transects, two North-South transects and in three localized areas to determine both the average annual strains over the past several years, and the variation in strain over the central Cascadia convergent margin. The North-South transects (composed of multiple baselines) show shortening. Along West-East transects some baselines show shortening and others extension. The direction of the principle strains calculated for two areas 100 km from the deformation front are close to per-pendicular to the deformation front. …

Portland Spectrum, February 2015, Portland State University. Student Publications Board

Portland Spectrum

Editor: Corinne Hutfilz

Articles in this issue include: Why the 2014 Flu Vaccine Fell Short; Student Efforts to Eradicate Sexual Assault on campus; Book Reviews by Spectrum Editors; and Death With Dignity

Analysis Of The Surface Density And Reactivity Of Perfluorophenylazide And The Impact On Ligand Immobilization, Gilad Zorn, David G. Castner, Anuradha Tyagi, Xin Wang, Hui Wang, Mingdi Yan

Chemistry Faculty Publications and Presentations

Perfluorophenylazide (PFPA) chemistry is a novel method for tailoring the surface properties of solid surfaces and nanoparticles. It is general and versatile, and has proven to be an efficient way to immobilize graphene, proteins, carbohydrates, and synthetic polymers. The main thrust of this work is to provide a detailed investigation on the chemical composition and surface density of the PFPA tailored surface. Specifically, gold surfaces were treated with PFPA-derivatized (11-mercaptoundecyl) tetra(ethylene glycol) (PFPA-MUTEG) mixed with 2-[2-(2-mercaptoethoxy)ethoxy]ethanol (MDEG) at varying solution mole ratios. Complementary analytical techniques were employed to characterize the resulting films including Fourier transform infrared spectroscopy to detect fingerprints …

Chemical Reaction Network Control Systems For Agent-Based Foraging Tasks, Joshua Stephen Moles

Dissertations and Theses

Chemical reaction networks are an unconventional computing medium that could benefit from the ability to form basic control systems. In this work, we demonstrate the functionality of a chemical control system by evaluating classic genetic algorithm problems: Koza's Santa Fe trail, Jefferson's John Muir trail, and three Santa Fe trail segments. Both Jefferson and Koza found that memory, such as a recurrent neural network or memories in a genetic program, are required to solve the task. Our approach presents the first instance of a chemical system acting as a control system. We propose a delay line connected with an artificial …

Fire Modulates Climate Change Response Of Simulated Aspen Distribution Across Topoclimatic Gradients In A Semi-Arid Montane Landscape, Jian Yang, Peter J. Weisberg, Douglas J. Shinneman, Thomas E. Dilts, Susan L. Earnst, Robert M. Scheller

Environmental Science and Management Faculty Publications and Presentations

Content Changing aspen distribution in response to climate change and fire is a major focus of biodiversity conservation, yet little is known about the potential response of aspen to these two driving forces along topoclimatic gradients.

Objective This study is set to evaluate how aspen distribution might shift in response to different climate-fire scenarios in a semi-arid montane landscape, and quantify the influence of fire regime along topoclimatic gradients.

Methods We used a novel integration of a forest landscape succession and disturbance model (LAN DIS-II) with a fine-scale climatic water deficit approach to simulate dynamics of aspen and associated conifer …

Surface Temperature Probability Distributions In The Narccap Hindcast Experiment: Evaluation Methodology, Metrics, And Results, Paul C. Loikith, Duane E. Waliser, Huikyo Lee, Jinwon Kim, J. David Neelin, Benjamin R. Lintner, Seth Mcginnis, Chris A. Mattmann, Linda O. Mears

Geography Faculty Publications and Presentations

Methodology is developed and applied to evaluate the characteristics of daily surface temperature distributions in a six-member regional climate model (RCM) hindcast experiment conducted as part of the North American Regional Climate Change Assessment Program (NARCCAP). A surface temperature dataset combining gridded station observations and reanalysis is employed as the primary reference. Temperature biases are documented across the distribution, focusing on the median and tails. Temperature variance is generally higher in the RCMs than reference, while skewness is reasonably simulated in winter over the entire domain and over the western United States and Canada in summer. Substantial differences in skewness …

Glacier Status And Contribution To Streamflow In The Olympic Mountains, Usa, Jon L. Riedel, Steve Wilson, William Baccus, Michael Larrabee, T.J. Fudge, Andrew G. Fountain

Geology Faculty Publications and Presentations

The Olympic Peninsula, Washington, USA, currently holds 184 alpine glaciers larger than 0.01 km² and their combined area is 30.2 ± 0.95km². Only four glaciers are >1km² and 120 of the others are -¹ (1900–80) to 0.54 km² a^-¹ (1980–2009). Thinning rates on four of the largest glaciers averaged nearly 1ma^-¹ from 1987 to 2010, resulting in estimated volume losses of 17–24%. Combined glacial snow, firn and ice melt in the Hoh watershed is in the range 63–79 ± 7 × 10⁶m³, or 9–15% of total May–September streamflow. In the critical August–September …

Research & Strategic Partnerships: Quarterly Review, Volume 2, Issue 2, Portland State University. Research & Strategic Partnerships

Portland State Research Magazine

The eleven stories in this Winter 2015 edition of the Research and Strategic Partnerships Quarterly Review explore an assortment of faculty and staff accomplishments, revealing common themes of technological innovation, public policy, strategic partnership, and improving human health.

Isolation Of Diverse Members Of The Aquificales From Geothermal Springs In Tengchong, China, Brian P. Hedlund, Anna-Louise Reysenbach, Liuquin Huang, John C. Ong, Zizhang Liu, Jeremy A. Dodsworth, Reham Ahmed, Amanda J. Williams, Brandon R. Briggs, Yitai Liu, Weiguo Hou, Hailiang Dong

Biology Faculty Publications and Presentations

The order Aquificales (phylum Aquificae) consists of thermophilic and hyperthermophilic bacteria that are prominent in many geothermal systems, including those in Tengchong, Yunnan Province, China. However, Aquificales have not previously been isolated from Tengchong. We isolated five strains of Aquificales from diverse springs (temperature 45.2–83.3°C and pH 2.6–9.1) in the Rehai Geothermal Field from sites in which Aquificales were abundant. Phylogenetic analysis showed that four of the strains belong to the genera Hydrogenobacter, Hydrogenobaculum, andSulfurihydrogenibium, including strains distant enough to likely justify new species ofHydrogenobacter and Hydrogenobaculum. The additional strain may represent a …