Physical Sciences and Mathematics Commons^™

Surface Energy Balance And Melt Thresholds Over 11 Years At Taylor Glacier, Antarctica, Matthew James Hoffman, Andrew G. Fountain, Glen E. Liston

Geography Faculty Publications and Presentations

In the McMurdo Dry Valleys, Victoria Land, Antarctica, melting of glacial ice is the primary source of water to streams, lakes, and associated ecosystems. To understand geochemical fluxes and ecological responses to past and future climates requires a physically based energy balance model. We applied a one-dimensional model to one site on Taylor Glacier using 11 years of daily meteorological data and seasonal ablation measurements. Inclusion of transmission of solar radiation into the ice was necessary to accurately model summer ablation and ice temperatures. Results showed good correspondence between calculated and measured ablation and ice temperatures over the 11 years. …

The Effect Of The Amide Substituent On The Biodistribution And Tolerance Of Lanthanide(Iii) Dota-Tetraamide Derivatives, Mark Woods, Peter Caravan, Carlos F.G.C. Geraldes, Matthew T. Greenfield, Garry Kiefer, Mai Lin, Kenneth Mcmillan, M. Isabel M. Prata, Ana C. Santos, Xiankai Sun, Jufeng Wang, Shanrong Zhang, Piyu Zhao, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Objectives—Recent advances in the design of MRI contrast agents have rendered the lanthanide complexes of DOTA-tetraamide ligands of considerable interest, both as responsive MR agents and paramagnetic chemical exchange saturation transfer agents. The potential utility of these complexes for in vivo applications is contingent upon them being well tolerated by the body. The purpose of this study was to examine how the nature of the amide substituent, and in particular its charge, affected the fate of these chelates postinjection.

Materials and Methods—Complexes of 6 DOTA-tetraamide ligands were prepared in which the nature of the amide substituent was systematically …

General Validity Of Reciprocity In Quantum Mechanics, P.T. Leung, H. Y. Xie, D. P. Tsai

Physics Faculty Publications and Presentations

The concept of reciprocity symmetry for matter-wave propagation is established for nonrelativistic quantum mechanics with previous results in the literature extended to include nonlocal interactions. Examples are given for cases with both local and nonlocal potentials, where we show in particular that reciprocity can be violated for the motion of a charged particle in an external electromagnetic field. In addition, this symmetry is applied to interpret a recent analysis [Phys. Rev. A 64, 042716 (2001)] on the symmetry of transmission through one-dimensional complex potentials, with the emphasis that the validity of reciprocity can go beyond that of time-reversal symmetry, such …

Alagnak Wild River Visitor Use Project: Alagnak Wild River Resident User Study, Douglas Deur

Anthropology Faculty Publications and Presentations

This report represents a thematic summary of findings from the Alagnak Wild River Resident Users Study, the final project in a larger series of studies conducted for the National Park Service (NPS) as part of the Alagnak Wild River Visitor Use Project. The National Park service administers the 56 miles of designated Wild River along the Alagnak in collaboration with the Alaska Department of Fish and Game, which manages fish and wildlife populations along the river. The NPS is charged with managing the river’s natural and cultural resources, as well as preserving the river’s lands and resources for current and …

The Distribution And Reproductive Success Of The Western Snowy Plover Along The Oregon Coast - 2008, David J. Lauten, Kathleen J. Castelein, David C. Bailey, Travis Lewis, Eleanor P. Gaines

Institute for Natural Resources Publications

From 1 April – 24 September 2008, we monitored the distribution, abundance and productivity of the federally Threatened Western Snowy Plover (Charadrius alexandrinus nivosus) along the Oregon coast. From north to south, we surveyed and monitored plover activity at Sutton Beach, Siltcoos River estuary, the Dunes Overlook, North Tahkenitch Creek, Tenmile Creek, Coos Bay North Spit, Bandon Beach, and New River. Our objectives for the Oregon coastal population in 2008 were to: 1) estimate the size of the adult Snowy Plover population, 2) locate plover nests, 3) continue selected use of miniexclosures (MEs) to protect nests from predators …

Progress Toward Meeting The Challenges Of Our Coastal Urban Future, Juile Pullen, Jason Ching, David J. Sailor, William Thompson, Bob Bornstein, Darko Koracin

Mechanical and Materials Engineering Faculty Publications and Presentations

The article provides information on the Seventh Conference on Coastal Atmospheric and Oceanic Prediction and Processes, and the Seventh Symposium on the Urban Environment in San Diego, California on September 9-13, 2008. Topics include the heterogeneity of urban areas, coastal vulnerabilities, urban planning, and emergency response modeling. The conference featured several speakers including Walter Dabberdt and James Voogt.

Irrelevance, Polymorphism, And Erasure In Type Theory, Richard Nathan Mishra-Linger

Dissertations and Theses

Dependent type theory is a proven technology for verified functional programming in which programs and their correctness proofs may be developed using the same rules in a single formal system. In practice, large portions of programs developed in this way have no computational relevance to the ultimate result of the program and should therefore be removed prior to program execution. In previous work on identifying and removing irrelevant portions of programs, computational irrelevance is usually treated as an intrinsic property of program expressions. We find that such an approach forces programmers to maintain two copies of commonly used datatypes: a …

Synthesis, Characterization And Reactivity Of Some Selected Organosulfur Oxo-Acids, Adenike Otoikhian

Dissertations and Theses

The two major metabolites after S-Oxygenation of dimethylthiourea (N, N'-dimethylaminoiminomethanesulfinic acid (DMAIMSA) and N, N'-dimethylamino iminomethanesulfonic acid (DMAIMSOA)) were synthesized. Structural analysis by X-ray crystallography shows that DMAIMSA and DMAIMSOA exist as zwitterionic species in their solid form, with a positive charge delocalized around an sp²-hybridized carbon center flanked by two nitrogen atoms.

Kinetics and mechanistic studies on the oxidation of DMAIMSA and DMAIMSOA by acidified iodate/iodine and bromate/bromine were studied. The results reveal that DMAIMSA, unlike DMAIMSOA, is highly reactive. DMAIMSOA is very inert and unreactive in low pH environments. The difference in reactivity is attributed to …

Polymeric Paracest Agents For Enhancing Mri Contrast Sensitivity, Yunkou Wu, Youfu Zhou, Olivier Quari, Mark Woods, Piyu Zhao, Todd B. Soesbe, Garry Kiefer, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Linear polymers of PARACEST agents were prepared by using classical free radical chain polymerization conditions. The Eu³⁺-polymers exhibited similar intermediate-to-slow water exchange and CEST characteristics as the Eu³⁺-monomers. This provided an avenue to lower the detection limit of these imaging agents substantially and makes them potentially useful as MRI sensors for molecular imaging.

Designing More Effective Air Quality Advisories, Justin Olexy

Environmental Science and Management Professional Master's Project Reports

Background: There is increasing concern about the impact of air quality on human health in urban environments and how to best reduce impacts through public policies. An NSF Biocomplexity Project - "Feedbacks between Urban Systems and the Environment" (FUSE), led by Portland State University, studies the human feedbacks and responses to air quality and heat advisories through data collected in city-wide phone surveys in Portland, OR and Houston, TX. On days when ozone levels are predicted to exceed air quality standards, regulatory agencies issue air quality advisories which ask residents to reduce certain air polluting behaviors such as driving …

Biomimetic Subwavelength Antireflective Gratings On Gaas, Chih-Hung Sun, Brian J. Ho, Bin Jiang, Peng Jiang

Mathematics and Statistics Faculty Publications and Presentations

We have developed a simple and scalable bottom-up approach for fabricating moth-eye antireflective coatings on GaAs substrates. Monolayer, non-close-packed silica colloidal crystals are created on crystalline GaAs wafers by a spin-coating-based single-layer reduction technique. These colloidal monolayers can be used as etching masks during a BCl_3 dry-etch process to generate subwavelength-structured antireflective gratings directly on GaAs substrates. The gratings exhibit excellent broadband antireflective properties, and the specular reflection matches with the theoretical prediction using a rigorous coupled-wave analysis model. These bioinspired antireflection coatings have important technological applications ranging from efficient solar cells to IR detectors

Northern Range Expansion And Coastal Occurrences Of The New Zealand Mud Snail Potamopyrgus Antipodarum (Gray, 1843) In The Northeast Pacific, Timothy Mathias Davidson, Valance E. F. Brenneis, Catherine E. De Rivera, Robyn Draheim, Graham E. Gillespie

Environmental Science and Management Faculty Publications and Presentations

The New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) is a common invasive species in fresh and brackish water ecosystems in Europe, Australia, Japan, and North America. In some invaded habitats, P. antipodarum can reach high densities (over 500,000 snails m^-2) and dominate the biomass of the benthos, leading to detrimental impacts to native biota and changes in ecosystem dynamics. We report the previously unpublished occurrence of P. antipodarum in thirteen fresh and brackish water systems adjacent to the Pacific coast of North America including a new northern range for P. antipodarum: Port Alberni, Vancouver Island, British …

Window Queries Over Data Streams, Jin Li

Dissertations and Theses

Evaluating queries over data streams has become an appealing way to support various stream-processing applications. Window queries are commonly used in many stream applications. In a window query, certain query operators, especially blocking operators and stateful operators, appear in their windowed versions. Previous research work in evaluating window queries typically requires ordered streams and this order requirement limits the implementations of window operators and also carries performance penalties. This thesis presents efficient and flexible algorithms for evaluating window queries. We first present a new data model for streams, progressing streams, that separates stream progress from physical-arrival order. Then, we …

The Original Build Up Of Genetic Information By Rna Recombination, Eric John Hayden

Dissertations and Theses

This research demonstrates chemical reactions of RNA molecules that allow them to increase in length, from non-catalytic oligomers to complex RNA enzymes. The purpose of this research was to explain the origin of large RNA polymers required for life to begin in the proposed "RNA World". To do this, the Azoarcus group I ribozyme was engineered to catalyze phosphodiester exchange reactions that result in the recombination of short oligomer substrates marked by ^5'CAU^3' recognition tags.

To demonstrate the ability to produce catalytic RNA sequences through recombination, substrate oligomers were synthesized that could produce ribozymes if large portions of …

Evidence On The Role Of Supplier-Retailer Trading Relationships And Practices In Waste Generation In The Food Chain, Carlos Mena, Peter Whitehead

Business Faculty Publications and Presentations

This report presents the results of the project entitled “Evidence on the role of supplier-retailer trading relationships and practices in waste generation in the food chain” commission by Defra (Project Code SFFSD0705) and undertaken by Cranfield University and IGD between July 2008 and June 2009.

The overall aim of the project was to provide a qualitative analysis of the food and packaging waste arising from the link between food manufacturers and retailers in the UK. The specific objectives of the project were:

• To identify the root causes of waste between suppliers and retailers in the UK
• To assess the magnitude …

Non-Canonical Binding Of Calmodulin To Aquaporin-0: Implications For Channel Regulation, Steve Reichow, Tamir Gonen

Chemistry Faculty Publications and Presentations

Aquaporins (AQPs) are a family of ubiquitous membrane channels that conduct water across cell membranes. AQPs form homo-tetramers containing four functional and independent water pores. Aquaporin-0 (AQP0) is expressed in the eye lens where its water permeability is regulated by calmodulin (CaM). Here we use a combination of biochemical methods and NMR spectroscopy to probe the interaction between AQP0 and CaM. We show CaM binds the AQP0 C-terminal domain in a calcium dependent manner. We demonstrate that only two CaM molecules bind a single AQP0 tetramer in a non-canonical fashion, suggesting a form of co-operativity between AQP0 monomers. Based on …

A Better Nondimensionalization Scheme For Slender Laminar Flows: The Laplacian Operator Scaling Method, Mark M. Weislogel, Yongkang Chen, D. Bolleddula

Mechanical and Materials Engineering Faculty Publications and Presentations

A scaling of the two-dimensional Laplacian operator is demonstrated for certain solutions (at least) to Poisson’s equation. It succeeds by treating the operator as a single geometric scale entity. The belated and rather subtle method provides an efficient assessment of the geometrical dependence of the problem and is preferred when practicable to the hydraulic diameter or term-by-term scaling for slender fully developed laminar flows. The improved accuracy further reduces the reliance of problems on widely varying numerical data or cumbersome theoretical forms and improves the prospects of exact or approximate theoretical analysis. Simple example problems are briefly described that demonstrate …

Dispersal Limitation And Climate-Related Environmental Gradients Structure Microcrustacean Composition In Freshwater Lakes, Ellesmere Island, Canada, Angela L. Strecker, Rebecca Milne, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future environmental change. We sampled and calculated relative abundances of microcrustacean species in 54 lakes on Ellesmere Island, Canada. New species records on Ellesmere Island included Daphnia umbra, Tachidius discipes, and Artemeopsis stefanssoni. Daphnia middendorffiana/tenebrosa was the most common taxon and often dominated microcrustacean assemblages, likely a result of its pigmentation, which offers resistance to ultraviolet radiation. Species richness was positively associated with nutrients, dissolved organic carbon (DOC), temperature, calcium, …

Students' Reasoning About The Concept Of Limit In The Context Of Reinventing The Formal Definition, Craig Alan Swinyard

Dissertations and Theses

Many researchers (Artigue, 2000; Bezuidenhout, 2001; Cornu, 1991; Dorier, 1995) have noted the vital role limit plays as a foundational concept in analysis. The vast majority of topics encountered in calculus and undergraduate analysis are built upon understanding the concept of limit and being able to work flexibly with its formal definition (Bezuidenhout, 2001). The purpose of this study was to: (1) Develop insight into students' reasoning about limit in relation to their engagement in instruction designed to support their reinventing the formal definition of limit, and; (2) Inform the design of principled instruction that might support students' attempts to …

Synthesis And Relaxometric Studies Of A Dendrimer‐Based Ph‐Responsive Mri Contrast Agent, M. Meser Ali, Mark Woods, Peter Caravan, Ana C.L. Opina, Marga Spiller, James C. Fettinger, A. Dean Sherry

Chemistry Faculty Publications and Presentations

The design of effective pH responsive MRI contrast agents is a key goal in the development of new diagnostic methods for conditions such as kidney disease and cancer. A key factor determining the effectiveness of an agent is the difference between the relaxivity of the “on” state compared to that of the “off” state. In this paper, we demonstrate that it is possible to improve the pH-responsive action of a low molecular weight agent by conjugating it to a macromolecular construct. The synthesis of a bifunctional pH responsive agent is reported. As part of that synthetic pathway we examine the …

Nanostructered Aminophenylporphyrin Films For Use In Bulk Heterojunction And Inverse Dye-Sensitized Tio₂ Solar Cells, Michael George Walter

Dissertations and Theses

Conductive nanostructured films of poly-tetrakis-5,10,15,20-(4-aminophenyl)porphyrin (TAPP) can be grown electrochemically or through interfacial oxidative polymerization. The poly-TAPP nanomorphology is sensitive to the electrochemical solvent, potentiometric method, and the aminophenyl porphyrin monomer utilized. To elucidate the molecular structure of poly-TAPP and to correlate structures with proposed polymerization and conductivity mechanisms, reflectance FT-IR and spectroelectrochemistry were used to detect the presence and electroactivity of dihydrophenazine and phenazine polymer linkages formed during the polymerization.

Poly-TAPP nanofiber films were evaluated for use in a bulk heterojunction solar cell (with PCBM) and in an inverse dye-sensitized TiO2 solar cell using the poly-TAPP nanoporous scaffold to …

Spatial Variability Of Methane Emissions From Rice Fields And Implications For Experimental Design, M. A. K. Khalil, Christopher Lee Butenhoff

Physics Faculty Publications and Presentations

It is observed that side by side plots in rice fields, managed by the same practices, produce methane emissions that are often different by factors of 2 to 4. Similarly on a given day when many plots are sampled, the emissions from one plot may differ from another by factors of 3-4 on average. These large variations must be taken into account if these data are extrapolated to larger scales such as countries or the world. In this paper we analyze and delineate the nature of this variability. We distinguish temporal and spatial variability and examine the effects of both …

Image Properties In An Aberration-Corrected Photoemission Electron Microscope, Rolf Könenkamp, T. Jones, J. Elstner, Robert Campbell Word, Gertrude Rempfer, Todd Dixon, Luis Almaraz, Walter P. Skoczylas

Physics Faculty Publications and Presentations

We report recent progress in the construction of a new aberration-corrected photoemission electron microscope. The correcting element in this instrument is a hyperbolic electron mirror which corrects for chromatic and spherical aberration. We present first images obtained with the new instrument and numerical results from trajectory and wave-optical calculations indicating that the resolution can be of the order of 1 nm.

Green Dyadic For The Proca Fields, P.T. Leung, Paul Dragulin

Physics Faculty Publications and Presentations

The dyadic Green functions for the Proca fields in free space are derived to include singular terms. Both the electric and magnetic types will be obtained with the results reduced back to those for the Maxwell fields in the limit of zero photon mass. Moreover, the singular terms are identical in both massless and massive electrodynamics. As an illustration, the results are applied to obtain the exact dynamical fields for an oscillating dipole which reduce back to the well-known expressions for static fields derived previously in the literature for massive electrodynamics.

Design And Synthesis Of Antimalarial Drugs Based On A Chloroquine Scaffold, Steven James Burgess

Dissertations and Theses

There are between 350 and 500 million clinical cases of malaria each year, and over 1 million deaths, with pregnant women and children under the age of 5 being most at risk. Chloroquine (CQ) became the preferred drug to treat malaria in the late 1940s, but is now rendered mostly ineffective in many parts of the world, due to widespread CQ resistance by the malaria parasite. All other malaria treatments suffer from some drawbacks, which include development of resistance, side effects including toxicity, risk for pregnant women and young children, and high cost. Some existing, non-antimalarial, drugs have been found …

What's Regulation Got To Do With It? : Examining The Impact Of Regulatory Intensity On Facility Environmental Management And Performance, Cody Jones

Dissertations and Theses

Understanding the influence of regulation on environmental management is important—studies typically find regulation to be a significant influence on environmental activity. However, studies typically assess regulation together with a suite of other influences such as investors and customers, which are often also found to be significant influences on environmental management. This research, on the other hand, suggests that regulatory constraints form a framework within which organizations operate, and therefore are associated with organizations' views of other motivating factors, as well as environmental management and performance. Additionally, this study assesses the influence of management attitudes toward environmental protection and attitudes toward …

A Novel Approach To The Synthesis Of Silicon Nanowires, Joo Chick Chan

Dissertations and Theses

Contemporary VLS-SiNW synthetic methods employ CVD and laser ablation methods that produce single crystalline SiNW; which can be doped by co-flowing appropriate dopants, such as diborane (p-type) and phosphine (n-type). Not only are these gases toxic (non-green), but also the synthetic methods used are costly requiring elaborate instrumental assembly. This thesis presents a low-cost and "green" method in synthesizing and doping of SiNW in a glass tube. It was found that by selecting the appropriate metal catalyst, precursor reactants, and the reaction conditions both SiNW and carbon nanotube (CNT) can be synthesized on metallic (aluminum and copper), semiconducting (silicon) and …

Seminaphthofluorones Are A Family Of Water-Soluble, Low Molecular Weight, Nir-Emitting Fluorophores, Youjun Yang, Mark Lowry, Xiangyang Xu, Jorge O. Escobedo, Martha Sibrian-Vazquez, Lisa Wong, Corin M. Schowalter, Timothy J. Jensen, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin

Chemistry Faculty Publications and Presentations

A readily accessible new class of near infrared (NIR) molecular probes has been synthesized and evaluated. Specific fluorophores in this unique xanthene based regioisomeric seminaphthofluorone dye series exhibit a combination of desirable characteristics including (i) low molecular weight (339 amu), (ii) aqueous solubility, and (iii) dual excitation and emission from their fluorescent neutral and anionic forms. Importantly, systematic changes in the regiochemistry of benzannulation and the ionizable moieties afford (iv) tunable deep-red to NIR emission from anionic species and (v) enhanced Stokes shifts. Anionic SNAFR-6, exhibiting an unusually large Stokes …

Creation Of Nanopatterns By Local Protonation Of P4vp Via Dip Pen Nanolithography, Carsten Maedler, S. Chada, Xiquan Cui, M. Taylor, Mingdi Yan, Andres H. La Rosa

Physics Faculty Publications and Presentations

The elastic mechanical response of a poly(4-vinylpyridine) film is exploited to create nanostructures under ambient conditions via dip pen nanolithography. Using a pH 4 phosphate buffer solution as the "ink," a series of experimental results indicates that the nanometer-sized structures are due to local swelling of the film’s pyridyl groups upon their protonation with the hydronium ions delivered by the tip. Control over the structures’ height is gained by properly selecting the writing velocities or the dwell time, respectively.

Production, Oxidation, And Emissions Of Methane From Rice Fields In China, M. A. K. Khalil, Martha J. Shearer, R. A. Rasmussen, Chang-Lin Duan, Lixin Ren

Physics Faculty Publications and Presentations

Detailed field studies of methane emissions from rice fields show that when nitrogen fertilizers are used with intermittent irrigation the seasonal average flux is about 3 mg/m²/hr. When continuous flooding and organic material is added to the same fields, the emissions rise to nearly 30 mg/m²/hr. Production rates measured during the two years when both organic material and water were applied to these fields were found to be 60 and 90 mg/m²/hr in consecutive years. The fraction oxidized is calculated to be about 80% one year and 43% the next year. The results suggest that high organic fertilizer increases production, …