Physical Sciences and Mathematics Commons^™

Computational Investigation Of The Mechanism Of An Octahedral Ni(Ii) Proton Reduction Catalyst And Importance Of Intramolecular Hydrogen Bonding, Avik Bhattacharjee, Dayalis S.V. Brown, Carolyn N. Virca, Trent E. Ethridge, Oreana Mendez Galue, Uyen T. Pham, Theresa M. Mccormick

Student Research Symposium

Water-splitting to make hydrogen gas is of extreme importance in the field of alternative energy research. Transition-metal complexes are capable of catalyzing the conversion of water to hydrogen at higher pH, with low overpotential. Our research focuses on the importance of intramolecular hydrogen bonding (H-bonding) on the pKa and thermodynamic stability of the catalytic intermediates of a well-known proton-reduction catalyst, nickel (II) tris-pyridinethiolate. Density Functional Theory (DFT) calculations on the parent catalyst and eleven derivatives demonstrate geometric isomer formation after the protonation step of catalysis. These isomers differ in the relative thermodynamic stabilities and pKa values, which can be attributed …

Stakeholder Perceptions Of Microplastics Management In Oregon, Maya A. Hurst-Mayr

Student Research Symposium

There is currently no federal policy in the United States that specifically addresses microplastics (MPs) pollution. However, states are beginning to act on this issue; California’s SB 1422 initiates measurement of MPs in drinking water resources and Senate Bill 1263 requires the state to adopt a strategy to reduce the ecological impact of MPs in marine ecosystems. Other West Coast states like Oregon and Washington are expected to follow California’s example. It is important to know what the actors who are a part of shaping MPs policy in Oregon would see as barriers and opportunities to doing so. We conducted …

Analysis Of Aftershock Parameters For The Alaskan Subduction Zone Tectonic Region, Gabrielle M. Paris (They/Them), Richard C. Hugo, Andrew J. Michael

Student Research Symposium

On 29 July 2021, a magnitude 8.2 earthquake was felt by over 200 people near Perryville, Alaska. The early aftershock forecasts issued by the USGS use default parameters based on expected productivity within a given tectonic region. These forecasts predicted a slower decrease in aftershock activity than what was observed. Even after the USGS adjusted the aftershock forecast parameters, the forecasts did not improve in the long term. Accurate aftershock predictions are important for maintaining public confidence in disaster alert systems. The question I want to explore is: are the generic parameters used in aftershock forecasting accurately describing the observed …

Discussion Of “Guiding Principles For Hydrologists Conducting Interdisciplinary Research And Fieldwork With Participants”, Melissa Haeffner

Environmental Science and Management Faculty Publications and Presentations

Rangecroft et al. (2021) offer a set of principles for conducting interdisciplinary research and fieldwork with participants from a hydrologist perspective. In this invited paper, I present some thoughts from a social scientist’s perspective, not to disagree with their points but to add to them. Specifically, I use my sociology background and interdisciplinary experiences to reflect on qualitative evaluative criteria, power dynamics in the scientific community, barriers to interdisciplinary research, and approaches to overcome obstacles. Individual researchers can educate themselves about other disciplines, and there are also opportunities for institutional change on the part of universities, funders, and …

Extending Tensor Virtual Machine To Support Deep-Learning Accelerators With Convolution Cores, Yanzhao Wang, Fei Xie

Computer Science Faculty Publications and Presentations

Deep-learning accelerators are increasingly popular. There are two prevalent accelerator architectures: one based on general matrix multiplication units and the other on convolution cores. However, Tensor Virtual Machine (TVM), a widely used deep-learning compiler stack, does not support the latter. This paper proposes a general framework for extending TVM to support deep-learning accelerators with convolution cores. We have applied it to two well-known accelerators: Nvidia's NVDLA and Bitmain's BM1880 successfully. Deep-learning workloads can now be readily deployed to these accelerators through TVM and executed efficiently. This framework can extend TVM to other accelerators with minimum effort.

Black Carbon Dominated Dust In Recent Radiative Forcing On Rocky Mountain Snowpacks, Kelly E. Gleason, Joseph R. Mcconnell, Monica M. Arienzo, Graham Sexstone, Stefan Rahimi

Environmental Science and Management Faculty Publications and Presentations

The vast majority of surface water resources in the semi-arid western United States start as winter snowpack. Solar radiation is a primary driver of snowmelt, making snowpack water resources especially sensitive to even small increases in concentrations of light absorbing particles such as mineral dust and combustion-related black carbon (BC). Here we show, using fresh snow measurements and snowpack modeling at 51 widely distributed sites in the Rocky Mountain region, that BC dominated impurity-driven radiative forcing in 2018. BC contributed three times more radiative forcing on average than dust, and up to 17 times more at individual locations. Evaluation of …

Sl-Cyclegan: Blind Motion Deblurring In Cycles Using Sparse Learning, Ali Syed Saqlain, Li-Yun Wang, Zhiyong Liu

Computer Science Faculty Publications and Presentations

In this paper, we introduce an end-to-end generative adversarial network (GAN) based on sparse learning for single image motion deblurring, which we called SL-CycleGAN. For the first time in image motion deblurring, we propose a sparse ResNet-block as a combination of sparse convolution layers and a trainable spatial pooler k-winner based on HTM (Hierarchical Temporal Memory) to replace non-linearity such as ReLU in the ResNet-block of SL-CycleGAN generators. Furthermore, we take our inspiration from the domain-to-domain translation ability of the CycleGAN, and we show that image deblurring can be cycle-consistent while achieving the best qualitative results. Finally, we perform extensive …

Objective Crystallographic Symmetry Classifications Of A Noisy Crystal Pattern With Strong Fedorov-Type Pseudo­Symmetries And Its Optimal Image-Quality Enhancement, Peter Moeck

Physics Faculty Publications and Presentations

Statistically sound crystallographic symmetry classifications are obtained with information-theory-based methods in the presence of approximately Gaussian distributed noise. A set of three synthetic patterns with strong Fedorov-type pseudo­symmetries and varying amounts of noise serve as examples. Contrary to traditional crystallographic symmetry classifications with an image processing program such as CRISP, the classification process does not need to be supervised by a human being and is free of any subjectively set thresholds in the geometric model selection process. This enables crystallographic symmetry classification of digital images that are more or less periodic in two dimensions (2D), also known as crystal …

Unveiling The Nature Of A Miniature World: A Horizon Scan Of Fundamental Questions In Bryology, Jairo Patiño, Irene Bisang, Bernard Goffinet, Lars Hedenäs, Stuart Mcdaniel, Silvia Pressel, Michael Stech, Claudine Ah-Peng, Sarah Eppley, Multiple Additional Authors

Center for Life in Extreme Environments Publications

Introduction: Half a century since the creation of the International Association of Bryologists, we carried out a review to identify outstanding challenges and future perspectives in bryology. Specifically, we have identified 50 fundamental questions that are critical in advancing the discipline.

Methods: We have adapted a deep-rooted methodology of horizon scanning to identify key research foci. An initial pool of 258 questions was prepared by a multidisciplinary and international working group of 32 bryologists. A series of online surveys completed by a broader community of researchers in bryology, followed by quality-control steps implemented by the working group, were …

The Connections Between Innovation, Culture, And Expertise In Water Infrastructure Organizations, Alice Brawley-Chesworth

Dissertations and Theses

Infrastructure organizations are notoriously conservative and resistant to change, even when faced with wicked problems that cannot be solved with the same thinking used in the past. In the water sector, this resistance to change has been linked to an industry culture that is based in a single, engineering-oriented knowledge system. Scholars have suggested that diversification of knowledge systems is necessary for implementation of innovations that will move the sector forward to solve wicked problems.

This research used a qualitative case study approach comparing two water sector organizations in Portland, Oregon. One organization included members who shared an engineering knowledge …

Oregon’S Place-Based Integrated Water Resources Planning Program: A Participatory Evaluation, Rebecca Mclain, Sadie Boyers, Jess Downey, Emily Jane Davis

National Policy Consensus Center Publications

In 2015, the Oregon Legislature passed ORS 536.220, which directed the Oregon Water Resources Department (OWRD) to develop an integrated water resources strategy and gave it authority to make grants and provide technical assistance to communities seeking to engage in place-based planning integrated water resources planning (hereafter place-based planning). The legislation provided a means by which Oregon communities could coordinate an assessment of the water needs of instream and out-of-stream water interests in their area and reach agreement on how those needs could be met now and in the future. Legislators structured the program to give persons who live, work, …

The Plant Water Management Experiments, Marc Benjamin Wasserman

Dissertations and Theses

A simple means of watering plants in the low-g environment aboard orbiting spacecraft is not obvious. Since the beginning of spaceflight, numerous approaches have been pursued to water plants that seek to maximize plant viability and system reliability, while minimizing crew time and system complexity. The Plant Water Management experiments (PWM) seek to apply recent advances in low-gravity capillary fluidics to the challenges faced during plant growth operations aboard spacecraft. One primary challenge encountered in such applications is to establish Earth-like flows, minimizing the low-g specific adaptations required by the plants. This is difficult due to the fluid physics challenges …

Quantification Of Motility In Bacillus Subtilis At Temperatures Up To 84°C Using A Submersible Volumetric Microscope And Automated Tracking, Megan M. Dubay, Nikki Johnston, Mark Wronkiewicz, Jake Lee, Chris Lindensmith, Jay Nadeau

Physics Faculty Publications and Presentations

We describe a system for high-temperature investigations of bacterial motility using a digital holographic microscope completely submerged in heated water. Temperatures above 90°C could be achieved, with a constant 5°C offset between the sample temperature and the surrounding water bath. Using this system, we observed active motility in Bacillus subtilis up to 66°C. As temperatures rose, most cells became immobilized on the surface, but a fraction of cells remained highly motile at distances of >100 μm above the surface. Suspended non-motile cells showed Brownian motion that scaled consistently with temperature and viscosity. A novel open-source automated tracking package was used …

Stakeholder Participation And Influence At State Public Utility Commissions, Genevieve Theresa Kruse

Dissertations and Theses

Despite the international consensus that climate change is a problem, few substantive policies are being pushed forward at the national level to meet international greenhouse gas reduction commitments under the Paris Agreement. The most significant climate change policies are emerging at state public utility commissions (PUCs). While PUCs were traditionally structured to regulate utilities, state PUCs are now finding themselves at the hub for renewable energy, clean energy, and distributed energy policies. Despite the increase in renewable and clean energy policies at state PUCs, there is a noticeably small environmental and clean energy stakeholder presence at those PUC proceedings. A …

Spatial And Temporal Variations Of Microplastic Concentrations In Portland's Freshwater Ecosystems, Rebecca Talbot, Elise F. Granek, Heejun Chang, Rosemary Wood, Susanne Brander

Geography Faculty Publications and Presentations

While microplastics are a pollutant of growing concern in various environmental compartments, less is known regarding the sources and delivery pathways of microplastics in urban rivers. We investigated the relationship between microplastic concentrations and various spatiotemporal factors (e.g., land use, arterial road length, water velocity, precipitation) in two watersheds along an urban-rural gradient in the Portland metropolitan area. Samples were collected in August, September, and February and were analyzed for total microplastic count and type. Nonparametric statistics were used to evaluate potential relationships with the explanatory variables, derived at both the subwatershed and near stream scales. In August, microplastic concentrations …

Environmental Decision Support Systems As A Service: Demonstration On Ce-Qual-W2 Model, Yoav Bornstein, Ben Dayan, Amir Cahn, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

An environmental decision support system (EDSS) can be used as an important tool for the rehabilitation and preservation of ecosystems. Nonetheless, high assimilation costs (both money and time) are one of the main reasons these tools are not widely adopted in practice. This work presents a low-cost paradigm of “EDSS as a Service.” This paradigm is demonstrated for developing a water quality EDSS as a service that utilizes the well-known CE-QUAL-W2 model as a kernel for deriving optimized decisions. The paradigm is leveraging new open-source technologies in software development (e.g., Docker, Kubernetes, and Helm) with cloud computing to significantly reduce …

The Trace Of T2 Takes No Repeated Values, Liubomir Chiriac, Andrei Jorza

Mathematics and Statistics Faculty Publications and Presentations

We prove that the trace of the Hecke operator T₂" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">T2 acting on the vector space of cusp forms of level one takes no repeated values, except for 0, which only occurs when the space is trivial.

Extreme Winds Alter Influence Of Fuels And Topography On Megafire Burn Severity In Seasonal Temperate Rainforests Under Record Fuel Aridity, Cody Evers, Andres Holz, Sebastian Upton Busby, Max Nielsen-Pincus

Environmental Science and Management Faculty Publications and Presentations

Nearly 0.8 million hectares of land were burned in the North American Pacific Northwest (PNW) over two weeks under record-breaking fuel aridity and winds during the extraordinary 2020 fire season, representing a rare example of megafires in forests west of the Cascade Mountains. We quantified the relative influence of weather, vegetation, and topography on patterns of high burn severity (>75% tree mortality) among five synchronous megafires in the western Cascade Mountains. Despite the conventional wisdom in climate-limited fire regimes that regional drivers (e.g., extreme aridity, and synoptic winds) overwhelm local controls on vegetation mortality patterns (e.g., vegetation structure and …

Gps-Derived Interseismic Fault Locking Along The Jalisco–Colima Segment Of The Mexico Subduction Zone, Beatriz Cosenza-Muralles, Charles Demets, B. Márquez-Azúa, O. Sánchez, J. Stock, Enrique Cabral-Cano, Robert Mccaffrey

Geology Faculty Publications and Presentations

Northeastward subduction of the oceanic Rivera and Cocos plates in western Mexico poses a poorly understood seismic hazard to the overlying areas of the North America plate. We estimate the magnitude and distribution of interseismic locking along the northern ∼500 km of the Mexico subduction zone, with a series of elastic half-space inversions that optimize the fits to the velocities of 57 GPS stations in western Mexico. All velocities were corrected for the co-seismic, afterslip and viscoelastic rebound effects of the 1995 Colima–Jalisco and 2003 Tecomán earthquakes. We explore the robustness of interseismic locking estimates to a variety of mantle …

Urban Flood Risk And Green Infrastructure: Who Is Exposed To Risk And Who Benefits From Investment? A Case Study Of Three U.S. Cities, Arun K. Pallathadka, Jason Sauer, Heejun Chang, Nancy B. Grimm

Geography Faculty Publications and Presentations

Pluvial flooding is a serious hazard in inland U.S. cities. City managers and communities are increasingly interested in reducing their pluvial flood risk through the development of green infrastructure (GI) features. This research explores the relationship between pluvial flood exposure and GI placement in three inland cities– Atlanta, Phoenix, and Portland–and analyzes the variation of sociodemographic variables in census block groups (CBG) located in pluvial flood zones. Using the Arc-Malstrøm method, we estimated areas of pluvial flooding in the CBGs of our selected cities by relating pluvial flood area to the density of GI in CBGs and assigning CBGs one …

Mass Capacity Analysis Of Stormwater Control Measures Using Synthetic Stormwater With Silica, Organic And Hydrocarbon Constituents, Craig Michael Fairbaugh

Dissertations and Theses

Stormwater control measure (SCM) performance is well studied regarding solids removal; however, analysis of mass loading capacity, long-term performance, and maintenance demands are challenging due to the variability and multiple constituents inherent in urban stormwater. This research examines the long-term water quality performance and sediment mass capacity of two common SCMs: high rate biofiltration (HRBF) and conventional bioretention (BRT). Pollutant removal trials were conducted in a laboratory setting per the New Jersey Department of Environmental Protection (NJDEP) filtration protocol in two phases: the first using inorganic sediment per the NJDEP protocol, the second phase with the addition of organic sediment …

Characterization Of High Mobility Channels For Use In Quantum Computing Devices, Payam Amin

Dissertations and Theses

Quantum computing promises computation that is fundamentally beyond the reach of classical computers. For the realization of a full-scale quantum computer, millions of quantum bits need to be fabricated on an integrated circuit and operated at cryogenic temperatures. Silicon and silicon-germanium based electron spin quantum bits have the advantage of leveraging decades of semiconductor industry knowledge for high volume manufacturability.

During the process development of any semiconductor device, material characterization is essential to understand and improve the process. Transmission electron microscopy is the only technique that could offer localized high spatial resolution characterization. In this work we have introduced two …

An Aggregation-Based Nonlinear Multigrid Solver For Two-Phase Flow And Transport In Porous Media, Chak Shing Lee, Francois Hamon, Nicola Castelletto, Panayot S. Vassilevski, Joshua A. White

Mathematics and Statistics Faculty Publications and Presentations

A nonlinear multigrid solver for two-phase flow and transport in a mixed fractional-flow velocity-pressure-saturation formulation is proposed. The solver, which is under the framework of the full approximation scheme (FAS), extends our previous work on nonlinear multigrid for heterogeneous diffusion problems. The coarse spaces in the multigrid hierarchy are constructed by first aggregating degrees of freedom, and then solving some local flow problems. The mixed formulation and the choice of coarse spaces allow us to assemble the coarse problems without visiting finer levels during the solving phase, which is crucial for the scalability of multigrid methods. Specifically, a …

Dependence Comparisons Of Order Statistics In The Proportional Hazards Model, Subhash C. Kochar

Mathematics and Statistics Faculty Publications and Presentations

Let X₁,…,X_n be mutually independent exponential random variables with distinct hazard rates λ₁,…,λ_n > 0 and let Y₁,…,Y_n be a random sample from the exponential distribution with hazard rate $\bar \lmd = \sum_{i=1}^n \lmd_i/n$. Also let X_1:n < ⋯ < X_n:n and Y_1:n < ⋯ < Y_n:n be their associated order statistics. It is shown that for 1 ≤ i < j ≤ n, the generalized spacing X_j:n - X _i:n is more dispersed than Y_j:n− Y_i:n according to dispersive ordering. This result is used to solve a long standing open problem …

Effects Of Pore-Forming Peptides (Melittin And Magainin 2) On The Phospholipid Bilayer Interior, Elmukhtar Ehmed Alhatmi

Dissertations and Theses

Antimicrobial peptides (AMPs) are one of the most promising solutions to drug-resistant bacteria. Melittin and magainin 2 are two of the most representative and extensively studied AMPs. In this research, I investigated the interaction of these two AMPs with three models of cell membranes: 80% POPC 20% POPG, 40%POPC 40% POPE and 20% POPG, and 80%POPC 20%POPG plus 30% mole fraction of cholesterol. Time-resolved fluorescence emission and fluorescence anisotropy decays of the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH) were analyzed to determine the effects of AMPs on the bilayer headgroup packing and changes in the interior of the phospholipid bilayer during the …

Fenchel-Rockafellar Theorem In Infinite Dimensions Via Generalized Relative Interiors, Dang Van Cuong, Mau Nam Nguyen, B. S. Mordukhovich, G. Sandine

Mathematics and Statistics Faculty Publications and Presentations

In this paper we provide further studies of the Fenchel duality theory in the general framework of locally convex topological vector (LCTV) spaces. We prove the validity of the Fenchel strong duality under some qualification conditions via generalized relative interiors imposed on the epigraphs and the domains of the functions involved. Our results directly generalize the classical Fenchel-Rockafellar theorem on strong duality from finite dimensions to LCTV spaces.

Using Intrinsically-Typed Definitional Interpreters To Verify Compiler Optimizations In A Monadic Intermediate Language, Dani Barrack

Dissertations and Theses

Compiler optimizations are critical to the efficiency of modern functional programs. At the same time, optimizations that unintentionally change the semantics of programs can systematically introduce errors into programs that pass through them. The question of how to best verify that optimizations and other program transformations preserve semantics is an important one, given the potential for error introduction. Dependent types allow us to prove that properties about our programs are correct, as well as to design data types and interpreters in such a way that they are correct-by-construction. In this thesis, we explore the use of dependent types and intrinsically-typed …

Coming To Know The Local Environment: Children's Experiences In Rautamai Gaunpalika, Nepal, Elsie Nicole Love

Dissertations and Theses

This qualitative research, conducted over three months from late monsoon season into early fall of 2018 with twenty-six children and thirteen adults, explores how children in the hills of Rautamai Gaunpalika, Province 1, Nepal come to know their local environment. Semi-structured interviews with children, their family members, and teachers, and participant observation with children as they worked and played in forests, fields, and streams, suggest that outside of school, children come to know their local environment in the following ways: through participation in and application of knowledge to subsistence practices; through collaborative learning and teaching in mixed-age groups; through relationships …

Cetacean Strandings In The Us Pacific Northwest 2000–2019 Reveal Potential Linkages To Oceanographic Variability, Amanda J. Warlick, Jessica L. Huggins, Dyanna M. Lambourn, Deborah A. Duffield, Dalin Nichole D'Alessandro, James M. Rice, John Calambokidis, M. Bradley Hanson, Joseph K. Gaydos, Multiple Additional Authors

Biology Faculty Publications and Presentations

Studying patterns in marine mammal stranding cases can provide insight into changes in population health, abundance, and distribution. Cetaceans along the United States West coast strand for a wide variety of reasons, including disease, injury, and poor nutritional status, all of which may be caused by both natural and anthropogenic factors. Examining the potential drivers of these stranding cases can reveal how populations respond to changes in their habitat, notably oceanographic variability and anthropogenic activities. In this study, we aim to synthesize recent patterns in 1,819 cetacean strandings across 26 species in the Pacific Northwest from 2000 to 2019 to …

Co-Seismic And Post-Seismic Deformation For The 1995 Colima–Jalisco And 2003 Tecoman Thrust Earthquakes, Mexico Subduction Zone, ́ From Modelling Of Gps Data, Beatriz Cosenza-Muralles, Charles Demets, O. Sanchez, Enrique Cabral-Cano, J. Stock, B. Márquez-Azúa, Robert Mccaffrey

Geology Faculty Publications and Presentations

We invert ∼25 yr of campaign and continuous Global Positioning System daily positions at 62 sites in southwestern Mexico to estimate co-seismic and post-seismic afterslip solutions for the 1995 M_w = 8.0 Colima–Jalisco and the 2003 M_w = 7.5 Tecomán earthquakes, and the long-term velocity of each GPS site. Estimates of the viscoelastic effects of both earthquakes from a 3-D model with an elastic crust and subducting slab, and linear Maxwell viscoelastic mantle are used to correct the GPS position time-series prior to our time-dependent inversions. The preferred model, which optimizes the fit to data from several years …