Physical Sciences and Mathematics Commons^™

La Yeguada Volcanic Complex, Western Panama : An Assessment Of The Geologic Hazards Using New 40Ar/39Ar Ages, Karinne L. Knutsen

Dissertations, Master's Theses and Master's Reports - Open

La Yeguada volcanic complex is one of three Quaternary volcanic centers in Panama, and is located on the southern slope of the Cordillera Central mountain range in western Panama, province of Veraguas. To assess potential geologic hazards, this study focused on the main dome complex near the village of La Laguna and also examined a cinder cone 10 km to the northwest next to the village of Media Luna. Based on newly obtained ⁴⁰Ar/³⁹Ar ages, the most recent eruption occurred approximately 32 000 years ago at the Media Luna cinder cone, while the youngest dated eruption at …

A New Technique For Firn Grain-Size Measurement Using Sem Image Analysis, N. E. Spaulding, D. A. Meese, I. Baker, Paul Andrew Mayewski Dr., Gordon S. Hamilton

Earth Science Faculty Scholarship

Firn microstructure is accurately characterized using images obtained from scanning electron microscopy (SEM). Visibly etched grain boundaries within images are used to create a skeleton outline of the microstructure. A pixel-counting utility is applied to the outline to determine grain area. Firn grain sizes calculated using the technique described here are compared to those calculated using the techniques of Cow (1969) and Gay and Weiss (1999) on samples of the same material, and are found to be substantially smaller. The differences in grain size between the techniques are attributed to sampling deficiencies (e.g. the inclusion of pore filler in the …

Ice Layers As An Indicator Of Summer Warmth And Atmospheric Blocking In Alaska, Eric P. Kelsey, Cameron P. Wake, Karl J. Kreutz, Erich Osterberg

Earth Science Faculty Scholarship

Samples were collected from a snow pit and shallow urn core near Kahiltna Pass (2970 m a.s.l.), Denali National Park, Alaska, USA, in May 2008. The record spans autumn 2003 to spring 2008 and reveals clusters of ice layers interpreted as summertime intervals of above-freezing temperatures. High correlation coefficients (0.75-1.00) between annual ice-layer thickness and regional summertime station temperatures for 4 years (n=4) indicate ice-layer thickness is a good proxy for mean and extreme summertime temperatures across Alaska, at least over the short period of record. A Rex-block (aka high-over-low) pattern, a downstream trough over Hudson Bay, Canada, and an …

Subcritical Propagation And Coalescence Of Oil-Filled Cracks: Getting The Oil Out Of Low-Permeability Source Rocks, Z.-H. Jin, Scott E. Johnson, Z. Q. Fan

Earth Science Faculty Scholarship

We use a fracture mechanics model to study subcritical propagation and coalescence of single and collinear oil-filled cracks during conversion of kerogen to oil. The subcritical propagation distance, propagation duration, crack coalescence and excess oil pressure in the crack are determined using the fracture mechanics model together with the kinetics of kerogen-oil transformation. The propagation duration for the single crack is governed by the transformation kinetics whereas the propagation duration for the multiple collinear cracks may vary by two orders of magnitude depending on initial crack spacing. A large amount of kerogen (>90%) remains unconverted when the collinear cracks …

Estimating The Maritime Component Of Aerosol Optical Depth And Its Dependency On Surface Wind Speed Using Satellite Data, Y. Lehahn, I. Koren, E. Boss, Y. Ben-Ami, O. Altaratz

Marine Sciences Faculty Scholarship

Six years (2003-2008) of satellite measurements of aerosol parameters from the Moderate Resolution Imaging Spectroradiometer (MODIS) and surface wind speeds from Quick Scatterometer (QuikSCAT), the Advanced Microwave Scanning Radiometer (AMSR-E), and the Special Sensor Microwave Imager (SSM/I), are used to provide a comprehensive perspective on the link between surface wind speed and marine aerosol optical depth over tropical and subtropical oceanic regions. A systematic comparison between the satellite derived fields in these regions allows to: (i) separate the relative contribution of wind-induced marine aerosol to the aerosol optical depth; (ii) extract an empirical linear equation linking coarse marine aerosol optical …

Nest-Site Selection And Nest Survival Of The Rusty Blackbird: Does Timber Management Adjacent To Wetlands Create Ecological Traps?, Luke L. Powell, Thomas P. Hodgman, William E. Glanz, James D. Osenton, Caleb M. Fisher

Biology and Ecology Faculty Scholarship

Animals are subject to ecological traps when anthropogenic changes create habitat that appears suitable but when selected results in decreased fitness. The Rusty Blackbird (Euphagus carolinus) breeds in boreal wetlands and has declined by 85–95% over the last half century. We studied nest-site selection and daily nest survival rate (DSR) of 43 Rusty Blackbird nests in northern New England and evaluated whether regenerating logged areas adjacent to wetlands created ecological traps. Although nesting adults avoided high-canopied forests and selected areas with dense balsam fir (Abies balasmea) 1 to 3 m high, those characteristics were not associated …

Estimating Permeability From The Grain-Size Distributions Of Natural Sediment, Lawrence Mastera

Browse all Theses and Dissertations

Permeability, k, can be estimated using the Kozeny-Carman equation, given a grain-size distribution with any number of grain-size categories and the porosity of a sediment. A recursive method was developed to calculate the effective grain-size parameter, d, for sediment mixtures with more than three grain sizes. The method was tested on four sediment models of sand, gravelly sand, sandy gravel, and open-framework gravel created from grain-size distributions. The k estimated from the recursive method were consistent with physical measurements of k.

A Randomized Sublinear Time Parallel Gcd Algorithm For The Erew Pram, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

We present a randomized parallel algorithm that computes the greatest common divisor of two integers of n bits in length with probability 1−o(1) that takes O(n log logn/ logn) time using O(n6 + ) processors for any > 0 on the EREW PRAM parallel model of computation. The algorithm either gives a correct answer or reports failure. We believe this to be the first randomized sublinear time algorithm on the EREW PRAM for this problem.

Genetic Evidence Of Illegal Trade In Protected Whales Links Japan With The Us And South Korea, C. Scott Baker, Debbie Steel, Yeyong Choi, Hang Lee, Kyung Seok Kim, Sung Kyoung Choi, Yong-Un Ma, Charles Hambleton, Louie Psihoyos, R. L. Brownell Jr,, Naoko Funahashi

United States Department of Commerce: Staff Publications

We report on genetic identification of ‘whale meat’ purchased in sushi restaurants in Los Angeles, CA (USA) in October 2009 and in Seoul, South Korea in June and September 2009. Phylogenetic analyses of mtDNA cytochrome b sequences confirmed that the products included three species of whale currently killed in the controversial scientific whaling program of Japan, but which are protected from international trade: the fin, sei and Antarctic minke. The DNA profile of the fin whale sold in Seoul established a match to products purchased previously in Japan in September 2007, confirming unauthorized trade between these two countries. Following species …

Predicting The Occurrence Of Atlantic Bluefin Tuna (Thunnus Thynnus) Larvae In The Northern Gulf Of Mexico: Building A Classification Model From Archival Data, Barbara A. Muhling, John T. Lamkin, Mitchell A. Roffer

United States Department of Commerce: Staff Publications

Although bluefin tuna are found throughout the Atlantic Ocean, spawning in the western Atlantic has been recorded predominantly in the Gulf of Mexico (GOM) in spring. Larval bluefin tuna abundances from the northern GOM are formulated into an index used to tune the adult stock assessment, and the variability of this index is currently high. This study investigated whether some of the variability in larval bluefin tuna abundances was related to environmental conditions, by defining associations between larval bluefin tuna catch locations, and a suite of environmental variables. We hypothesized that certain habitat types, as defined by environmental variables, would …

Fisheries Buybacks: A Review And Guidelines, Dale Squires

United States Department of Commerce: Staff Publications

Buybacks of fishing vessels, licences, access and other rights, and gear, sometimes called decommissioning schemes, have traditionally been a key policy tool to address overcapacity, overexploitation of fish stocks, and distributional issues in fisheries. Two more issues can be added, sustainable use of ecosystems and conservation of biodiversity (i.e. ecological public goods and services) and providing a transition to a more rationalized fishery. This study discusses reasons for buybacks; examines consequences; considers asymmetric information, design of buyback auctions and other design issues; buybacks as a transition to a rationalized industry with strong property rights and governance, financing and transnational fisheries; …

Regional Seismicity Of The Mid-Atlantic Ridge: Observations From Autonomous Hydrophone Arrays, N. Simão, J. Escartín, J. Goslin, J. Haxel, M. Cannat, R. Dziak

United States Department of Commerce: Staff Publications

Autonomous hydrophones arrays are an excellent tool for monitoring mid-ocean ridge seismic activity. The major advantage of using arrays of autonomous hydrophones for recording deepocean ridge earthquakes is its low magnitude detection thresholds achievable using hydroacoustic techniques. Regional analysis of the detection thresholds of the different autonomous hydrophones arrays deployed along the Mid-Atlantic Ridge reveals the strong influence of the detection threshold in the number of recorded events and it must be taken into account in any further analysis. In this study, the analysis of both autonomous hydrophones and teleseismically detected Mid-Atlantic Ridge seismicity reveals that the background seismicity from …

Validation Of A Homologous Canine Relaxin Radioimmunoassay And Application With Pregnant And Non-Pregnant Northern Fur Seals (Callorhinus Ursinus), Don R. Bergfelt, Bernard G. Steinetz, J. Lawrence Dunn, Shannon Atkinson, J. Ward Testa, Gregg P. Adams

United States Department of Commerce: Staff Publications

The primary objectives of this study were to validate a canine relaxin RIA for use in otariids and phocids and consider practical applications. For 6 captive Northern fur seal females, serum samples were grouped and examined according to pregnancy (n = 13), post-partum (n = 8) and non-pregnancy (n = 6), and, for 2 captive Northern fur seal males, serum samples were grouped and examined together regardless of age (2 mo–15 yrs, n = 6). Placental tissue was available for examination from one Northern fur seal, Steller sea lion and harbor seal. The validation process involved several steps using an …

System Dynamics Modeling Of Corn Ethanol As A Bio Transportation Fuel In The United States, Deogratias Kibira, Guodong Shao, Stephen Nowak

United States Department of Commerce: Staff Publications

The production capacity of corn ethanol as a transportation fuel is experiencing rapid growth in the United States. The demand is driven by increased prices of gasoline, government mandates, incentives, desire for cleaner fuels, and the need to achieve energy independence. Continued strong growth of the corn ethanol industry will depend on profitability by both suppliers and producers. This in turn will be influenced by several factors such as demand, government incentives, feedstock availability and prices, processing plant capacity, and efficient farm and ethanol processing technologies. How and to what extent will the projected growth of the corn ethanol industry …

Long-Term Survival Of Humpback Whales Radio-Tagged In Alaska From 1976 Through 1978, Sally Mizroch, Michael F. Tillman, Susan Jurasz, Janice Straley, Olga Von Ziegesar, Louis Herman, Adam Pack, Scott Baker, Jim Darling, Debbie Glockner-Ferrari, Mark Ferrari, Dan Salden, P J. Clapham

United States Department of Commerce: Staff Publications

Invasive tags designed to provide information on animal movements through radio or satellite monitoring have tremendous potential for the study of whales and other cetaceans. However, to date there have been no published studies on the survival of tagged animals over periods of years or decades. Researchers from the National Marine Mammal Laboratory and the Woods Hole Oceanographic Institution tracked five humpback whales with implanted radio tags in southeastern Alaska in August 1976 and July 1977, and tracked two humpback whales in Prince William Sound, Alaska, in June 1978. All seven of these individually identified humpback whales were resighted at …

Seasonal Home Ranges And Fidelity To Breeding Sites Among Ringed Seals, Brendan P. Kelly, Oriana H. Badajos, Mervi Kunnasranta, John R. Moran, Micaela Martinez-Bakker, Peter Boveng, Douglas Wartzok

United States Department of Commerce: Staff Publications

Population structure and patterns of habitat use among ringed seals (Phoca hispida) are poorly known, in part because seasonal movements have not been adequately documented. We monitored the movements of 98 ringed seals in the Beaufort and Chukchi seas between 1990 and 2006 using three forms of telemetry. In the winter—spring period (when the seals were occupying shorefast ice), we used radio and ultra-sonic tags to track movements above and below the ice, respectively. We used satellite-linked transmitters in summer and fall (when the seals ranged away from their winter sites) to track at-sea movements. In the shorefast …

Hierarchical Bayesian Spatial Models For Multispecies Conservation Planning And Monitoring, Carlos Carroll, Devin S. Johnson, Jeffrey R. Dunk, William J. Zielinski

United States Department of Commerce: Staff Publications

Biologists who develop and apply habitat models are often familiar with the statistical challenges posed by their data’s spatial structure but are unsure of whether the use of complex spatial models will increase the utility of model results in planning. We compared the relative performance of nonspatial and hierarchical Bayesian spatial models for three vertebrate and invertebrate taxa of conservation concern (Church’s sideband snails [Monadenia churchi], red tree voles [Arborimus longicaudus], and Pacific fishers [Martes pennanti pacifica]) that provide examples of a range of distributional extents and dispersal abilities. We used presence–absence data derived from regional monitoring programs to develop …

Vertical Profiles Of Co2 Above Eastern Amazonia Suggest A Net Carbon Flux To The Atmosphere And Balanced Biosphere Between 2000 And 2009, L. V. Gatti, J. B. Miller, M. T. S. D'Amelio, A. Martinewski, L. S. Basso, M. E. Gloor, S. Wofsy, P. Tans

United States Department of Commerce: Staff Publications

From 2000 until January 2010 vertical profiles were collected above eastern Amazonia to help determine regional-scale (∼10⁵–10⁶ km²) fluxes of carbon cycle-related greenhouse gases. Samples were collected aboard light aircraft between the surface and 4.3 km and a column integration technique was used to determine the CO₂ flux. Measured CO₂ profiles were differenced from the CO₂ background determined from measurements in the tropical Atlantic. The observed annual flux between the coast and measurement sites was 0.40 ± 0.27 gC m⁻² d⁻¹ (90% confidence interval using a bootstrap analysis). The wet …

Bass’ Nk Groups And Cd H-Fibrant Hochschild Homology, G. Cortiñas, C. Haesemeyer, Mark E. Walker, C. Weibel

Department of Mathematics: Faculty Publications

The K-theory of a polynomial ring R[t ] contains the K-theory of R as a summand. For R commutative and containing Q, we describe K∗(R[t ])/K∗(R) in terms of Hochschild homology and the cohomology of Kähler differentials for the cdh topology.

We use this to address Bass’ question, whether K_n(R) = K_n(R[t ]) implies K_n(R) = K_n(R[t₁, t₂]). The answer to this question is affirmative when R is essentially of …

What Are The Causes, Consequences And Correctives Of Fish Contamination In The Detroit River Aoc That Cause Health Consumption Advisories? (Final Report, Michigan Sea Grant Michu-T-10-001), Donna R. Kashian, Ken G. Drouillard, D. Haffner, Ann E. Krause, Z Liu, Larissa Sano

Environmental Science and Geology Faculty Research Publications

Using an Integrated Assessment (IA) framework, we consolidated and utilized existing data from the Detroit River to develop models that both identify possible drivers of elevated fish contaminant body burdens, and to facilitate a more risk-based approach of tissue trigger-levels for consumption advisories. This integrated assessment approach was particularly useful for consumption advisories as it provided the ability to integrate and organize complex data in a manner that can help inform management decisions. In addition, the IA framework explicitly fosters collaboration and participation of multiple interested groups. We have capitalized on this component of IAs, by seeking the active participation …

Oxygen And Hydrogen Diffusion In Minerals, John Richard Farver

School of Earth, Environment and Society Faculty Publications

This chapter provides a summary and review of experimentally determined oxygen and hydrogen volume diffusion in minerals. A very extensive and detailed review of stable isotope exchange processes including oxygen and hydrogen volume diffusion can be found in Cole and Chakraborty (2001) and a detailed review of hydrogen diffusion in minerals, especially nominally anhydrous minerals, can be found in Ingrin and Blanchard (2006). In addition, a detailed review of oxygen and hydrogen diffusion in silicate melts is provided by Zhang and Ni (2010), and oxygen and hydrogen diffusion rates can also be found in the chapters, in this volume, on …

Embracing The Vision: Our Work With Teachers Implementing Gps, Sarah Ledford, Wendy B. Sanchez

Proceedings of the Annual Meeting of the Georgia Association of Mathematics Teacher Educators

Abstract: In 2005, three Kennesaw State University mathematics education faculty members began a series of workshops titled “Implementing the Georgia Performance Standards [GPS]: Embracing the Vision.” This workshop series has been underwritten by Georgia’s Teacher Quality Higher Education Program. The first series of workshops began with 6th grade teachers the first year the GPS was implemented and the project has been funded each subsequent year since its inception. Currently, we are working with Math III teachers as they implement the course for the first time. The initial focus for the project was on conceptual understanding versus procedural understanding, writing tasks …

Portland State University Climate Action Plan, 2010, Fletcher Beaudoin, Noelle Studer-Spevak

Campus Sustainability Office Publications, Reports and Presentations

In June 2007, Portland State University (PSU) joined this effort by signing the American College and University Presidents Climate Commitment (ACUPCC). The commitment challenged PSU to form a committee to oversee climate efforts, track carbon emissions, and develop a Climate Action Plan (CAP) to move toward carbon neutrality. This document fulfills the final requirement for ACUPCC and supports regional climate goals of partner agencies, such as those described in the 2009 City of Portland and Multnomah County Climate Action Plan.

Collaborating To Meet The Standards: Implications For Professional Development, Erik D. Jacobson, Laura M. Singletary

Proceedings of the Annual Meeting of the Georgia Association of Mathematics Teacher Educators

Researchers from the University of Georgia interviewed 27 Mathematics 1 teachers about their experiences during the first year of the high school implementation of the Georgia Performance Standards (GPS). We report our findings about teachers’ experiences with Mathematics 1 professional development and describe features of professional development that teachers identified as most beneficial. Some teachers offered suggestions for professional development that differed from the professional development they had experienced. In addition, we found that many teachers used collaborative strategies to meet the demands of the new curriculum and the perceived inadequacies of resources and training. We discuss the various models …

Parallelization Of The Wolff Single-Cluster Algorithm, Jevgenijs Kaupužs, Jānis Rimšāns, Roderick V.N. Melnik

Mathematics Faculty Publications

A parallel [open multiprocessing (OpenMP)] implementation of the Wolff single-cluster algorithm has been developed and tested for the three-dimensional (3D) Ising model. The developed procedure is generalizable to other lattice spin models and its effectiveness depends on the specific application at hand. The applicability of the developed methodology is discussed in the context of the applications, where a sophisticated shuffling scheme is used to generate pseudorandom numbers of high quality, and an iterative method is applied to find the critical temperature of the 3D Ising model with a great accuracy. For the lattice with linear size L=1024, we have …

Quantum Corrections To The Gravitational Potential And Orbital Motion, Ioannis Haranas, Vasile Mioc

Physics and Computer Science Faculty Publications

GRT predicts the existence of relativistic corrections to the static Newtonian potential, which can be calculated and verified experimentally. The idea leading to quantum corrections at large distances consists of the interactions of massless particles, which only involve their coupling energies at low energies. Using the quantum correction term of the potential we obtain the perturbing quantum acceleration function. Next, with the help of the Newton-Euler planetary equations, we calculate the time rates of changes of the orbital elements per revolution for three different orbits around the primary. For one solar mass primary and an orbit with semimajor axis and …

Srpt Is 1.86-Competitive For Completion Time Scheduling, Christine Chung, Tim Nonner, Alexander Souza

Computer Science Faculty Publications

No abstract provided.

Stochastic Electromagnetic Beams In Positive-And Negative-Phase Materials, Zhisong Tong, Olga Korotkova

Physics Articles and Papers

Theoretical analysis of interaction of stochastic electromagnetic beamlike fields with positive- and negative-phase materials suggests that suitable combinations of such materials can serve as media where spectral, coherence, and polarization properties of beams can self-reconstruct.

Spectral Shifts And Switches In Random Fields Upon Interaction With Negative-Phase Materials, Zhisong Tong, Olga Korotkova

Physics Articles and Papers

Spectral shifts in stochastic beam-like fields on interaction with layers of positive- and negative-phase materials are examined on the basis of the ABCD-matrix approach and generalized Huygens-Fresnel principle. It is found that boundaries between such materials may cause spectral switches. Effect of absorption of negative-phase materials on the beam spectrum is discussed. Our results may find applications in connection with spectrum-selection optical interconnects, spectrally encoded information transfer, image formation in systems involving negative-phase materials, and geometrically tunable metamaterials.

Theory Of Weak Scattering Of Stochastic Electromagnetic Fields From Deterministic And Random Media, Zhisong Tong, Olga Korotkova

Physics Articles and Papers

The theory of scattering of scalar stochastic fields from deterministic and random media is generalized to the electromagnetic domain under the first-order Born approximation. The analysis allows for determining the changes in spectrum, coherence, and polarization of electromagnetic fields produced on their propagation from the source to the scattering volume, interaction with the scatterer, and propagation from the scatterer to the far field. An example of scattering of a field produced by a δ-correlated partially polarized source and scattered from a δ-correlated medium is provided.