Physical Sciences and Mathematics Commons^™

Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland …

The Record‐Breaking 2015 Hurricane Season In The Eastern North Pacific: An Analysis Of Environmental Conditions, Jennifer Collins, Philip J. Klotzbach, Ryan N. Maue, David R. Roache, Eric S. Blake, Charles H. Paxton, Christopher A. Mehta

School of Geosciences Faculty and Staff Publications

The presence of a near‐record El Niño and a positive Pacific Meridional Mode provided an extraordinarily warm background state that fueled the 2015 eastern North Pacific hurricane season to near‐record levels. We find that the western portion of the eastern North Pacific, referred to as the Western Development Region (WDR; 10°–20°N, 116°W–180°), set records for named storms, hurricane days, and Accumulated Cyclone Energy in 2015. When analyzing large‐scale environmental conditions, we show that record warm sea surface temperatures, high midlevel relative humidity, high low‐level relative vorticity, and record low vertical wind shear were among the environmental forcing factors contributing to …

The Subject Librarian Newsletter, Statistics, Fall 2016, Patti Mccall

Libraries' Newsletters

No abstract provided.

The Subject Librarian Newsletter, Chemistry, Fall 2016, Patti Mccall

Libraries' Newsletters

No abstract provided.

The Subject Librarian Newsletter, Physics, Fall 2016, Patti Mccall

Libraries' Newsletters

No abstract provided.

Commentary: Are National Parks Still Relevant?, Randall K. Wilson

Environmental Studies Faculty Publications

On the occasion of the National Parks centennial comes an irreverent question: Are the parks still relevant?

Famously christened as America's "best idea" by writer Wallace Stegner and reaffirmed in Ken Burns' 2009 PBS documentary, it seems brazen, if not blasphemous, to pose the question. [excerpt]

Systematic Bias In Baroclinic Energy Estimates In Shelf Seas, Gordon R. Stephenson, J. A. Mattias Green, Mark E. Inall

Faculty Publications

A simple model of an internal wave advected by an oscillating barotropic flow suggests flaws in standard approaches to estimating properties of the internal tide. When the M₂ barotropic tidal current amplitude is of similar size to the phase speed of the M₂ baroclinic tide, spectral and harmonic analysis techniques lead to erroneous estimates of the amplitude, phase, and energy in the M₂ internal tide. In general, harmonic fits and bandpass or low-pass filters that attempt to isolate the lowest M₂ harmonic significantly underestimate the strength of M₂ baroclinic energy fluxes in shelf seas. Baroclinic …

Transients In The Synchronization Of Asymmetrically Coupled Oscillator Arrays, Carlos E. Cantos, David K. Hammond, J.J.P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

We consider the transient behavior of a large linear array of coupled linear damped harmonic oscillators following perturbation of a single element. Our work is motivated by modeling the behavior of flocks of autonomous vehicles. We first state a number of conjectures that allow us to derive an explicit characterization of the transients, within a certain parameter regime Ω. As corollaries we show that minimizing the transients requires considering non-symmetric coupling, and that within Ω the computed linear growth in N of the transients is independent of (reasonable) boundary conditions.

The Close Agn Reference Survey (Cars): Mrk 1018 Returns To The Shadows After 30 Years As A Seyfert 1, R. E. Mcelroy, Bernd Husemann, S. M. Croom, T. A. Davis, Vardha N. Bennert, G. Busch, F. Combes, A. Eckart, M. Perez-Torres, M. Powell, J. Scharwächter, G. R. Tremblay, T. Urrutia

Physics

We report the discovery that the known “changing look” AGN Mrk 1018 has changed spectral type for a second time. New VLT-MUSE data taken in 2015 as part of the Close AGN Reference Survey (CARS) shows that the AGN has returned to its original Seyfert 1.9 classification. The CARS sample is selected to contain only bright type 1 AGN, but Mrk 1018’s broad emission lines and continuum, typical of type 1 AGN, have almost entirely disappeared. We use spectral fitting of the MUSE spectrum and previously available spectra to determine the drop in broad line flux and the Balmer decrement. …

A Supervised Classification Method For Levee Slide Detection Using Complex Synthetic Aperture Radar Imagery, Ramakalavathi Marapareddy, James V. Aanstoos, Nicolas H. Younan

Faculty Publications

The dynamics of surface and sub-surface water events can lead to slope instability, resulting in anomalies such as slough slides on earthen levees. Early detection of these anomalies by a remote sensing approach could save time versus direct assessment. We have implemented a supervised Mahalanobis distance classification algorithm for the detection of slough slides on levees using complex polarimetric Synthetic Aperture Radar (polSAR) data. The classifier output was followed by a spatial majority filter post-processing step that improved the accuracy. The effectiveness of the algorithm is demonstrated using fully quad-polarimetric L-band Synthetic Aperture Radar (SAR) imagery from the NASA Jet …

Probabilistic Methods In Information Theory, Erik W. Pachas

Electronic Theses, Projects, and Dissertations

Given a probability space, we analyze the uncertainty, that is, the amount of information of a finite system, by studying the entropy of the system. We also extend the concept of entropy to a dynamical system by introducing a measure preserving transformation on a probability space. After showing some theorems and applications of entropy theory, we study the concept of ergodicity, which helps us to further analyze the information of the system.

Modeling Of Historic Columbia River Flood Impacts Based On Delft 3d Simulations, Lumas Terence Helaire

Dissertations and Theses

Natural and anthropogenic processes over the past 150 years have altered the bathymetry of the Lower Columbia River (LCR) and have changed the long wave propagation of tides and floods. Possible causes for the increase in tidal amplitudes (+7% in tidal range in Astoria) are decreases in river discharge, lengthening of the river channel due to the construction of jetties at the mouth, dredging and deepening of the shipping channel, and reduction of the tidal prism due to the filling and diking of tidal wetlands. In this study, changes in the characteristics of long waves are elucidated by developing two …

Modeling X-Ray Emission Line Profiles From Massive Star Winds - A Review, Richard Igance

ETSU Faculty Works

The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation. Wind-broadened emission lines have been spectroscopically resolved for many massive stars. This contribution reviews approaches to the modeling of X-ray emission line profile shapes from single stars, including smooth winds, winds with clumping, optically thin versus thick lines, and the effect of a radius-dependent photoabsorption coefficient.

Creating And Automatically Grading Annotated Questions, Alicia Crowder Wood

Theses and Dissertations

We have created a question type that allows teachers to easily create questions, helps provide an intuitive user experience for students to take questions, and reduces the time it currently takes teachers to grade and provide feedback to students. This question type, or an "annotated" question, will allow teachers to test students' knowledge in a particular subject area by having students "annotate" or mark text and video sources to answer questions. Through user testing we determined that overall the interface and the implemented system decrease the time it would take a teacher to grade annotated quiz questions. However, there are …

Increasing The Computational Efficiency Of Combinatoric Searches, Wiley Spencer Morgan

Theses and Dissertations

A new algorithm for the enumeration of derivative superstructures of a crystal is presented. The algorithm will help increase the efficiency of computational material design methods such as cluster expansion by increasing the size and diversity of the types of systems that can be modeled. Modeling potential alloys requires the exploration of all possible configurations of atoms. Additionally, modeling the thermal properties of materials requires knowledge of the possible ways of displacing the atoms. One solution to finding all symmetrically unique configurations and displacements is to generate the complete list of possible configurations and remove those that are symmetrically equivalent. …

Natural And Anthropogenic Sources Of Arsenic And Nitrate In A Semi-Arid Alluvial Basin; Goshen Valley, Utah, Brian John Selck

Theses and Dissertations

Arsenic (As) and nitrate (NO₃) are common contaminants in groundwater that are introduced through a variety of natural and anthropogenic sources. In this study we investigated the sources and distribution of As and NO₃ in Goshen Valley, Utah, USA. Goshen Valley is a semi-arid alluvial basin that is impacted by geothermal waters, agriculture, urban development, and legacy mining. In this study we sampled surface water, springs, and wells to analyze concentrations of major ions, trace elements (As, B, Ba, Ca, Fe, K, Li, Mg, Mn, Mo, Pb, Si, Sr, Zn), and stable isotopes in water (δ^{18 …}

On The Geometry Of The Rotating Liquid Drop, Ivailo M. Mladenov, John Oprea

Mathematics and Statistics Faculty Publications

Here we consider the problem of a fluid body rotating with a constant angular velocity and subjected to surface tension. Determining the equilibrium configuration of this system turns out to be equivalent to the geometrical problem of determining the surface of revolution with a prescribed mean curvature. In the simply connected case, the equilibrium surface can be parameterized explicitly via elliptic integrals of the first and second kind. Here, we present two such parameterizations of the drops and we use the second of them to study finer details of the drop surfaces such as the existence of closed geodesics.

What Is The Pcor Partnership?, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet describing the Plains CO₂ Reduction (PCOR) Partnership. Outlines the phases of U.S. Department of Energy National Energy Technology Laboratory’s Regional Carbon Sequestration Partnership program and highlights PCOR Partnership accomplishments. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Co2 Sequestration Test In A Deep, Unminable Lignite Seam, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet describing results of a Plains CO₂ Reduction (PCOR) Partnership-implemented test to determine the possibility of storing CO₂ in unminable lignite seams. Discusses testing procedure and purpose, and summarizes key results. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Cross-Cultural User Perceptions Of Website Design And Security: Introduction To A Commentary And Response On Cyr (2013), Robert John Kauffman

Research Collection School Of Computing and Information Systems

Just as the well-known statistician, George Box, commented in a 1978 paper, “All models are wrong, but some are useful,” so are there many ways to design research inquiry approaches to explore issues in various e-commerce contexts – all useful too. In the two brief essays that follow, the reader will see a written commentary and a response that illustrates this idea. It occurred between a technology researcher who published an article on cross-cultural issues in website design in Cyr (2013), and an economist who is able to offer useful insights on the statistical work and data analytics with methods …

Secure Multiset Intersection Cardinality And Its Application To Jaccard Coefficient, Bharath K. Samanthula, Wei Jiang

Computer Science Faculty Research & Creative Works

The Jaccard Coefficient, as an information similarity measure, has wide variety of applications, such as cluster analysis and image segmentation. Due to the concerns of personal privacy, the Jaccard Coefficient cannot be computed directly between two independently owned datasets. The problem, secure computation of the Jaccard Coefficient for multisets (SJCM), considers the situation where two parties want to securely compute the random shares of the Jaccard Coefficient between their multisets. During the process, the content of each party's multiset is not disclosed to the other party and also the value of Jaccard Coefficient should be hidden from both parties. Secure …

Superconducting And Normal State Properties Of The Systems La1−Xmxpt4ge12 (M=Ce,Th), K. Huang, D. Yazici, Benjamin D. White, I. Jeon, A. J. Breindel, N. Pouse, M. B. Maple

All Faculty Scholarship for the College of the Sciences

Electrical resistivity, magnetization, and specific heat measurements were performed on polycrystalline samples of the filled-skutterudite systems La₁−_xM_xPt₄Ge₁₂ (M = Ce and Th). Superconductivity in LaPt₄Ge₁₂ was quickly suppressed with Ce substitution and no evidence for superconductivity was found down to 1.1 K for x > 0.2. Temperature-dependent specific heat data at low temperatures for La₁−_xCe_xPt₄Ge₁₂ show a change from powerlaw to exponential behavior, which may be an indication for multiband superconductivity in LaPt₄Ge₁₂. …

The Economic Value Of Forest Park Ecosystem Services: Results Of Five Focus Groups Conducted In Spring 2016, Randall A. Bluffstone, Pablo Barreyro, Jenny Dempsey Stein, Cody Kent, Antonia Machado

Economics Faculty Publications and Presentations

Objective: This initial phase of research lays the foundation for a survey using contingent valuation (CV) and choice experiment (CE) methods. We asked select Portland residents what they care about most in Forest Park, their willingness to pay (WTP) for improving ecosystem services and how they generally think about the value of those goods and services. These results will help us narrow the experimental design of the forthcoming CV/CE study.

Approach: We conducted a focus group in each of Portland’s 5 “quadrants.” We chose each location - Skyline, St. John’s, Cully, Foster-Powell and Hillsdale - based on either its proximity …

High Speed X-Ray Phase Contrast Imaging Of Energetic Composites Under Dynamic Compression, Niranjan D. Parab, Zane A. Roberts, Michael H. Harr, Jesus O. Mares, Alex D. Casey, I. Emre Gunduz, Matthew Hudspeth, Benjamin Claus, Tao Sun, Kamel Fezzaa, Steven F. Son, Weinong W. Chen

Purdue Energetics Research Center Articles

Fracture of crystals and frictional heating are associated with the formation of “hot spots” (localized heating) in energetic composites such as polymer bonded explosives (PBXs). Traditional high speed optical imaging methods cannot be used to study the dynamic sub-surface deformation and the fracture behavior of such materials due to their opaque nature. In this study, high speed synchrotron X-ray experiments are conducted to visualize the in situ deformation and the fracture mechanisms in PBXs composed of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) crystals and hydroxyl-terminated polybutadiene binder doped with iron (III) oxide. A modified Kolsky bar apparatus was used to apply controlled dynamic compression …

A Comparison Of Solvent And Water-Borne Alkyd Coatings And The History Of Voc Regulations In The United States, Molly Elise Burns

Master's Theses

A Comparison of Solvent and Water-Borne Alkyd Coatings Abstract

Conventional solvent based alkyd coatings have gone out of favor due to concerns over volatile organic compound (VOC) content. However, due to recent focus on renewable raw materials, alkyds are making a comeback in waterborne form. Water based alkyd coatings are known to have poor shelf stability and corrosion resistance, as well as other problems during the formulation process. This project focused on comparing solvent borne to two types of water-borne alkyds, water reducible alkyds and alkyds emulsions. The purpose was to understand the differences between the three types of alkyds …

High Correlation Of Middle East Respiratory Syndrome Spread With Google Search And Twitter Trends In Korea, Soo-Yong Shin, Dong-Woo Seo, Jisun An, Haewoon Kwak, Sung-Han Kim, Jin Gwack, Min-Woo Jo

Research Collection School Of Computing and Information Systems

The Middle East respiratory syndrome coronavirus (MERS-CoV) was exported to Korea in 2015, resulting in a threat to neighboring nations. We evaluated the possibility of using a digital surveillance system based on web searches and social media data to monitor this MERS outbreak. We collected the number of daily laboratory-confirmed MERS cases and quarantined cases from May 11, 2015 to June 26, 2015 using the Korean government MERS portal. The daily trends observed via Google search and Twitter during the same time period were also ascertained using Google Trends and Topsy. Correlations among the data were then examined using Spearman …

Room-Temperature Electrochemical Reduction Of Epitaxial Bi₂O₃ Films To Epitaxial Bi Films, Zhen He, Jakub Adam Koza, Ying-Chau Liu, Qingzhi Chen, Jay A. Switzer

Chemistry Faculty Research & Creative Works

This work reports a new facile approach to fabricate high-quality epitaxial Bi thin films by direct electrochemical reduction of epitaxial δ-Bi₂O₃ thin films on Au single crystals in aqueous solution at room-temperature. The as-produced Bi thin films (without any post-annealing process) exhibit large grain sizes, continuous microstructures, and enhanced magnetotransport properties.

The Subject Librarian Newsletter, Mathematics, Fall 2016, Patti Mccall

Libraries' Newsletters

No abstract provided.

No Contact Terms For The Magnetic Field In Lorentz- And Cpt-Violating Electrodynamics, Karl Schober, Brett Altschul

Faculty Publications

In a Lorentz- and CPT-violating modification of electrodynamics, the fields of a moving charge are known to have unusual singularities. This raises the question of whether the singular behavior may include δ-function contact terms, similar to those that appear in the fields of idealized dipoles. However, by calculating the magnetic field of an infinite straight wire in this theory, we demonstrate that there are no such contact terms in the magnetic field of a moving point charge.

Systems Modeling To Improve The Hydro-Ecological Performance Of Diked Wetlands, Omar Alminagorta, David E. Rosenberg, Karin M. Kettenring

Publications

Water scarcity and invasive vegetation threaten arid-region wetlands and wetland managers seek ways to enhance wetland ecosystem services with limited water, labor, and financial resources. While prior systems modeling efforts have focused on water management to improve flow-based ecosystem and habitat objectives, here we consider water allocation and invasive vegetation management that jointly target the concurrent hydrologic and vegetation habitat needs of priority wetland bird species. We formulate a composite weighted usable area for wetlands (WU) objective function that represents the wetland surface area that provides suitable water level and vegetation cover conditions for priority bird species. Maximizing …