Digital Commons Network^™

Silicic Volcanism At The Northern And Western Extent Of The Columbia River Basalt Rhyolite Flare-Up: Rhyolites Of Buchanan Volcanic Complex And Dooley Mountain Volcanic Complex, Oregon, Adam M. Large

Dissertations and Theses

Two mid-Miocene (16.5-15 Ma) rhyolite volcanic centers in eastern Oregon, the Buchanan rhyolite complex and Dooley Mountain rhyolite complex, were investigated to characterize eruptive units through field and laboratory analysis. Results of petrographic and geochemical analysis add to field observations to differentiate and discriminate the eruptive units. Additionally, new geochemical data are used to correlate stratigraphically younger and older basalt and ash-flow tuff units with regional eruptive units to constrain the eruptive periods with modern Ar-Ar age dates.

Previous work at the Buchanan rhyolite complex was limited to regional mapping (Piper et al., 1939; Greene et al., 1972) and brief …

Quef And Quef-Like: Diverse Chemistries In A Common Fold, Adriana Bon Ramos

Dissertations and Theses

The tunneling fold (T-Fold) superfamily is a small superfamily of enzymes found in organisms encompassing all kingdoms of life. Seven members have been identified thus far. Despite sharing a common three-dimensional structure these enzymes perform very diverse chemistries.

QueF is a bacterial NADPH-dependent oxidoreductase that catalyzes the reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ₀) to a primary amine (preQ₁) in the queuosine biosynthetic pathway. Previous work on this enzyme has revealed the mechanism of reaction but the cofactor binding residues remain unknown. The experiments discussed herein aim to elucidate the role of residues lysine 80, …

Conventionalizing And Axiomatizing In A Community College Mathematics Bridge Course, Mark Alan Yannotta

Dissertations and Theses

This dissertation consists of three related papers. The first paper, Rethinking mathematics bridge courses--An inquiry model for community colleges, introduces the activities of conventionalizing and axiomatizing from a practitioner perspective. In the paper, I offer a curricular model that includes both inquiry and traditional instruction for two-year college students interested in mathematics. In particular, I provide both examples and rationales of tasks from the research-based Teaching Abstract Algebra for Understanding (TAAFU) curriculum, which anchors the inquiry-oriented version of the mathematics bridge course.

The second paper, the role of past experience in creating a shared representation system for a mathematical operation: …

Thermal Decomposition Of Electronic Cigarette Liquids, Robert Paul Jensen

Dissertations and Theses

Electronic cigarette liquid (e-liquid) is a solution of propylene glycol and/or glycerol with varying concentrations of nicotine and flavorants. Inhalation of vaporized e-liquid is a method of nicotine delivery that is growing in popularity and is commonly regarded as safe relative to smoking traditional tobacco products. The thermal decomposition of glycerol and propylene glycol is typical of alcohols and has been investigated, although not exhaustively. In this work, samples of propylene glycol and glycerol were vaporized using an electronic cigarette (e-cigarette) and were analyzed for evidence of decomposition using nuclear magnetic resonance (NMR) spectroscopy. E-cigarettes are shown to degrade glycerol …

Architectures And Algorithms For Intrinsic Computation With Memristive Devices, Jens Bürger

Dissertations and Theses

Neuromorphic engineering is the research field dedicated to the study and design of brain-inspired hardware and software tools. Recent advances in emerging nanoelectronics promote the implementation of synaptic connections based on memristive devices. Their non-volatile modifiable conductance was shown to exhibit the synaptic properties often used in connecting and training neural layers. With their nanoscale size and non-volatile memory property, they promise a next step in designing more area and energy efficient neuromorphic hardware.

My research deals with the challenges of harnessing memristive device properties that go beyond the behaviors utilized for synaptic weight storage. Based on devices that exhibit …

Improving The Roadside Environment Through Integrating Air Quality And Traffic-Related Data, Christine M. Kendrick

Dissertations and Theses

Urban arterial corridors are landscapes that give rise to short and long-term exposures to transportation-related pollution. With high traffic volumes, congestion, and a wide mix of road users and land uses at the road edge, urban arterial environments are important targets for improved exposure assessment to traffic-related pollution. Applying transportation management strategies to reduce emissions along arterial corridors could be enhanced if the ability to quantify and evaluate such actions was improved. However, arterial roadsides are under-sampled in terms of air pollution measurements in the United States and using observational data to assess such effects has many challenges such as …

Breaking Spaces And Forms For The Dpg Method And Applications Including Maxwell Equations, Carsten Carstensen, Leszek Demkowicz, Jay Gopalakrishnan

Mathematics and Statistics Faculty Publications and Presentations

Discontinuous Petrov Galerkin (DPG) methods are made easily implementable using `broken' test spaces, i.e., spaces of functions with no continuity constraints across mesh element interfaces. Broken spaces derivable from a standard exact sequence of first order (unbroken) Sobolev spaces are of particular interest. A characterization of interface spaces that connect the broken spaces to their unbroken counterparts is provided. Stability of certain formulations using the broken spaces can be derived from the stability of analogues that use unbroken spaces. This technique is used to provide a complete error analysis of DPG methods for Maxwell equations with perfect electric boundary conditions. …

Relative Sensitivities Of Dce-Mri Pharmacokinetic Parameters To Arterial Input Function (Aif) Scaling, Xin Li, Yu Cai, Brendan Moloney, Yiyi Chen, Wei Huang, Mark Woods, Fergus V. Coakley, William D. Rooney, Mark G. Garzotto, Charles S. Springer Jr.

Chemistry Faculty Publications and Presentations

Dynamic-Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) has been used widely for clinical applications. Pharmacokinetic modeling of DCE-MRI data that extracts quantitative contrast reagent/tissue-specific model parameters is the most investigated method. One of the primary challenges in pharmacokinetic analysis of DCE-MRI data is accurate and reliable measurement of the arterial input function (AIF), which is the driving force behind all pharmacokinetics. Because of effects such as inflow and partial volume averaging, AIF measured from individual arteries sometimes require amplitude scaling for better representation of the blood contrast reagent (CR) concentration time-courses. Empirical approaches like blinded AIF estimation or reference tissue AIF derivation …

Groundwater-Surface Water Interactions Near Mosier, Oregon, Cullen Brandon Jones

Dissertations and Theses

The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that …

Raps Sheet, Summer 2016, Retirement Association Of Portland State

RAPS Sheet: Monthly Newsletter

No abstract provided.

Utilizing Egocentric Video And Sensors To Conduct Naturalistic Bicycling Studies, Feng Liu, Miguel A. Figliozzi

TREC Final Reports

Existing data collection methods are mostly designed for videos captured by stationary cameras and are not designed to follow cyclists along a route or to integrate other sensor data. The goals of this research are: a) to develop a platform to collect naturalistic video bicycling data, b) to develop a methodology to integrate video data with other sensors that measure cyclists’ position and comfort levels, and c) to apply the platform and data collection methodology to a real-world route. This research effort has successfully integrated video and sensor data to describe cyclists’ comfort levels along a route. It was found …

Generating Technology Development Paths To The Desired Future Through System Dynamics Modeling And Simulation, Hongyi Chen, Jiang Yu, Wayne Wakeland

Complex Systems Faculty Publications and Presentations

Technology foresight is usually conducted by government or industry associations and can serve to provide companies with information on critical technologies that a country or industry intends to develop in the next ten to twenty years. For individual companies to benefit from foresight results and transform them into specific technology development plans, the relationships between the desired technologies and the dynamic business environment need to be understood. In this article, an innovation diffusion model implemented via system dynamics simulation is used to operationalize the link between foresight and planning. It helps company decision makers visualize the diffusion process of the …

Molecular Probes For Pancreatic Cancer Imaging, Lei Wang

Dissertations and Theses

Pancreatic ductal adenocarcinoma (PDAC) has the poorest five-year survival rate of any cancer. Currently, there are no effective diagnostics or chemotherapeutics. Surgical resection is the only curative therapy. However, most patients experience recurrence due largely to challenges in assessing tumor margin status in the operating room. Molecular probes that selectively highlight pancreatic cancer tissue, having the potential to improve PDAC margin assessment intraoperatively, are urgently needed. In this work, a series of red and near-infrared fluorescent probes is reported. Two were found to distribute to normal pancreas following systemic administration. One selectively accumulates in genetically modified mouse models of PDAC, …

Multiple New-Particle Growth Pathways Observed At The Us Doe Southern Great Plains Field Site, Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. Mcmurry, James N. Smith, Jeffery R. Pierce

Civil and Environmental Engineering Faculty Publications and Presentations

New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low volatility species, from diameters ∼ 1 to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids …

Minimizing Corrosion Of Outdoor Metalworks Using Dispersed Chemically Stabilized Nanoclays In Polyvinylidene Fluoride Latex Coatings, Natasja Alexandria Swartz, Capri A. Price, Tami Lasseter Clare

Chemistry Faculty Publications and Presentations

Nanoclays are small enough to appear optically transparent, yet they have large surface-to-volume and high aspect ratios that can significantly inhibit water diffusion when incorporated into protective coatings. Clear coatings, which minimally affect the aesthetics of metalworks, are commonly applied to outdoor metalworks, such as sculptures, to prevent and slow corrosion. In recent years, waterborne clear coatings, rather than solvent-based clear coatings, are increasingly used in many applications to reduce the quantity of volatile organic components in the formulation, yet the performance of dry films produced from waterborne colloidal suspensions is generally poorer. In this work, we aim to improve …

Do Forest Commons Contribute To International Environmental Initiatives? A Socio-Ecological Analysis Of Nepalese Forest Commons In View Of Redd+, Harisharan Luintel

Dissertations and Theses

Forests in developing countries have the potential to contribute to global efforts to mitigate climate change, promote biodiversity and support the livelihoods of rural, local people. Approximately one-fourth of such forests are under the control of local communities, which primarily manage forests for subsistence and to meet their livelihood needs. The trend of bottom-up community control is increasing through the adoption of decentralization reforms over the last 40 years. In contrast, the United Nations has introduced the top-down program, Reducing Emissions from Deforestation and Forest Degradation (REDD+) for the conservation and enhancement of forest carbon and the sustainable management of …

Bridging The Worlds Of Home And School: A Study Of The Relational Worlds Of First-Generation Students In A School Of Social Work, Miranda Cunningham

Dissertations and Theses

Much scholarship on first-generation students has focused on their academic and social integration in college (Collier & Morgan, 2008; Lowery-Hart & Pacheco, 2011; Stuber, 2011). Little is known about the experiences of first-generation students in schools of social work. In this research I've expanded the focus beyond students' experiences of academic integration to explore how first-generation students in a school of social work describe their relational worlds and the implications for professional socialization.

Informed by Standpoint Feminism and Postmodern/Post structural Feminism, I conducted focus groups with 19 students in two undergraduate programs and one graduate program in a school of …

Controls On Turbulent Mixing In A Strongly Stratified And Sheared Tidal River Plume, Joseph T. Jurisa, Jonathan Nash, James N. Moum, Levi F. Kilcher

Civil and Environmental Engineering Faculty Publications and Presentations

Considerable effort has been made to parameterize turbulent kinetic energy (TKE) dissipation rate εand mixing in buoyant plumes and stratified shear flows. Here, a parameterization based on Kunze et al. is examined, which estimates ε as the amount of energy contained in an unstable shear layer (Ri < Ri_c) that must be dissipated to increase the Richardson number Ri = N²/S² to a critical value Ri_c within a turbulent decay time scale. Observations from the tidal Columbia River plume are used to quantitatively assess the relevant parameters controlling ε over a range of tidal …

Determining The Power And Energy Capacity Of A Battery Energy Storage System Utilizing A Smoothing Feeder Profile To Accommodate High Photovoltaic Penetration On A Distribution Feeder, Osama Mohammed Abbas Aly Mansour

Dissertations and Theses

Electricity is a perishable commodity; once it is generated it needs to be consumed or stored. Electric energy storage provides both power and energy capacity. Power capacity applications reduce the need for generation, while energy capacity allows for energy consumption to be decoupled from generation. Previous research was done to develop an algorithm for determining the power (MW) and energy (MWh) capacities of a battery energy storage system (BESS) to mitigate the adverse impacts of high levels of photovoltaic (PV) generation. The algorithm used a flat feeder profile, and its performance was demonstrated on the equinoxes and solstices.

Managing feeder …

Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko

Dissertations and Theses

Magnetic resonance imaging (MRI) has become a powerful clinical modality in diagnostic medicine. It is non-invasive and offers high spatial and temporal resolution. The goal of molecular imaging is to reveal the pathophysiology underlying the observed anatomy and diagnose diseases. The detection of pathological biomarkers can lead to early recognition of diseases and improved monitoring for recurrence. Clinically available contrast agents are limited in their discrimination of contrast between tissues and they tend to have very high detection limits. Because biomarkers are very low in concentration there is a need for high payload deposition of contrast agent (CA) and targeted …

Household Water Filter Use Characterization In Rural Rwanda: Signal Interpretation, Development And Validation, Sarita Lucia Tellez Sanchez

Dissertations and Theses

Access to safe drinking water is an important health factor in many developing countries. Studies have shown that unsafe drinking water and poor sanitation practices leads to diarrheal disease, which is one of the leading causes of death of children under five in developing countries. Provision and proper use of household water filters have been shown to effectively improve health.

This thesis is focused on the refinement and validation of algorithms for data collected from pressure transducer sensors that are used in household water filters (the Vestergaard Frandsen LifeStraw Family 2.0) deployed in Rwanda by the social enterprise DelAgua Health. …

Discovery And Characterization Of The Proteins Involved In The Synthesis Of N⁶-Threonylcarbamoyl Adenosine, A Nucleoside Modification Of Trna, Christopher Wayne Deutsch

Dissertations and Theses

N6-threonylcarbamoyl adenosine (t⁶A) is a universally conserved tRNA modification found at position 37 of tRNAs which decode ANN codons. Structural studies have implicated its presence as a requirement for the disruption of a U-turn motif in certain tRNAs, leading to the formation of properly structured anticodon stem loop. This structure is proposed to enhance the base pairing between U₃₆ of tRNA and A₁ of the codon which aids in translational frame maintenance.

Despite significant effort since its discovery in the 1970s the enzymes involved in its biosynthesis remained undiscovered. Bioinformatic analysis identified two proteins as likely …

Variation In Tussock Architecture Of The Invasive Cordgrass Spartina Densiflora Along The Pacific Coast Of North America, Jesus M. Castillo, Brenda J. Grewall, Andrea Pickart, Enrique Figueroa, Mark D. Sytsma

Environmental Science and Management Faculty Publications and Presentations

Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality has been described as a significant factor contributing to invasiveness. We studied the abiotic environment and the responses of different tussock architecture traits of the invasive cordgrass Spartina densiflora Brongn. (Poaceae). A common garden experiment and field studies of S. densiflora in salt marshes across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provided a model system for an integrated study of the potential mechanisms underlying the response …

Vision-Based Motion For A Humanoid Robot, Khalid Abdullah Alkhulayfi

Dissertations and Theses

The overall objective of this thesis is to build an integrated, inexpensive, human-sized humanoid robot from scratch that looks and behaves like a human. More specifically, my goal is to build an android robot called Marie Curie robot that can act like a human actor in the Portland Cyber Theater in the play Quantum Debate with a known script of every robot behavior. In order to achieve this goal, the humanoid robot need to has degrees of freedom (DOF) similar to human DOFs. Each part of the Curie robot was built to achieve the goal of building a complete humanoid …

Watershed Management And Private Lands: Moving Beyond Financial Incentives To Encourage Land Stewardship, Matthew Thomas Deangelo

Dissertations and Theses

Public water utilities are tasked with providing high quality, inexpensive water often sourced from watersheds representing a diverse mix of public and private land ownership. There is increasing recognition amongst water resource managers of the role that private landowners play in determining downstream water quality, but bringing together landowners with a wide variety of land management objectives under the umbrella of watershed stewardship has proven difficult. Recently, a large number of "Payment for Watershed Services" programs have aimed to engage private landowners in watershed stewardship initiatives by offering financial incentives for adopting watershed best management practices. However, a growing field …

Frequency Multiplication In Silicon Nanowires, Marius Mugurel Ghita

Dissertations and Theses

Frequency multiplication is an effect that arises in electronic components that exhibit a non-linear response to electromagnetic stimuli. Barriers to achieving very high frequency response from electronic devices are the device capacitance and other parasitic effects such as resistances that arise from the device geometry and are in general a function of the size of the device. In general, smaller device geometries and features lead to a faster response to electromagnetic stimuli. It was posited that the small size of the silicon nanowires (SiNWs) would lead to small device capacitance and spreading resistance, thus making the silicon nanowires useful in …

Wake Character In The Wind Turbine Array: (Dis-)Organization, Spatial And Dynamic Evolution And Low-Dimensional Modeling, Nicholas Michael Hamilton

Dissertations and Theses

To maximize the effectiveness of the rapidly increasing capacity of installed wind energy resources, new models must be developed that are capable of more nuanced control of each wind turbine so that each device is more responsive to inflow events. Models used to plan wind turbine arrays and control behavior of devices within the farm currently make questionable estimates of the incoming atmospheric flow and update turbine configurations infrequently. As a result, wind turbines often operate at diminished capacities, especially in arrays where wind turbine wakes interact and inflow conditions are far from ideal. New turbine control and wake prediction …

Assessment Of A Mycorrhizal Fungi Application To Treat Stormwater In An Urban Bioswale, Alaina Diane Melville

Dissertations and Theses

This study assessed the effect of an application of mycorrhizal fungi to stormwater filter media on urban bioswale soil and stormwater in an infiltration-based bioswale aged 20 years with established vegetation. The study tested the use of commercially available general purpose biotic soil blend PermaMatrix^® BSP Foundation as a treatment to enhance Earthlite^™ stormwater filter media amelioration of zinc, copper, and phosphorus in an ecologically engineered structure designed to collect and infiltrate urban stormwater runoff before it entered the nearby Willamette River.

These results show that the application of PermaMatrix^® BSP Foundation biotic soil amendment to Earthlite …

Genomics-Informed Isolation And Characterization Of A Symbiotic Nanoarchaeota System From A Terrestrial Geothermal Environment, Louie Wurch, Richard J. Giannone, Bernard S. Belisle, Carolyn Swift, Sagar Utturkar, Robert L. Hettich, Anna-Louise Reysenbach, Mircea Podar

Biology Faculty Publications and Presentations

Biological features can be inferred, based on genomic data, for many microbial lineages that remain uncultured. However, cultivation is important for characterizing an organism’s physiology and testing its genome-encoded potential. Here we use single-cell genomics to infer cultivation conditions for the isolation of an ectosymbiotic Nanoarchaeota (‘Nanopusillus acidilobi’) and its host (Acidilobus, a crenarchaeote) from a terrestrial geothermal environment. The cells of ‘Nanopusillus’ are among the smallest known cellular organisms (100–300 nm). They appear to have a complete genetic information processing machinery, but lack almost all primary biosynthetic functions as well as respiration and …

Active Object Localization In Visual Situations, Max H. Quinn, Anthony Rhodes, Melanie Mitchell

Computer Science Faculty Publications and Presentations

—We describe a method for performing active localization of objects in instances of visual situations. A visual situation is an abstract concept—e.g., “a boxing match”, “a birthday party”, “walking the dog”, “waiting for a bus”—whose image instantiations are linked more by their common spatial and semantic structure than by low-level visual similarity. Our system combines given and learned knowledge of the structure of a particular situation, and adapts that knowledge to a new situation instance as it actively searches for objects. More specifically, the system learns a set of probability distributions describing spatial and other relationships among relevant objects. The …