Physical Sciences and Mathematics Commons^™

Defect Contributions To Conductivity In Poly(3-Hexylthiophene)?, A. N. Caruso, D.-Q. Feng, Yaroslav B. Losovyj, D. L. Schulz, Snjezana Balaz, Luis G. Rosa, Andrei Sokolov, Bernard Doudin, Peter A. Dowben

Peter Dowben Publications

We find evidence for a gradual change in the electronic properties of spin coated poly(3-hexylthiophene) thin films with temperature. The conduction properties appears to be mediated by hopping conduction dominated by a low density of defects states within the highest occupied molecular orbital to lowest unoccupied molecular orbital gap, not by a change in band gap. The photoemission and transport measurements indicate a loss of charge mobility or carrier concentration occurs with decreasing temperature, while the molecular configuration (through chain conjugation) also changes with temperature. The defects states identified by photoemission (–1.7 eV) as well as others contributing to the …

Estimates Of Breeding Bird Populations In The Sheyenne National Grassland, North Dakota, Mary Ann Cunningham, Douglas Johnson, Daniel N. Svingen

The Prairie Naturalist

We conducted a two-year survey of breeding birds in the Sheyenne National Grassland, North Dakota, to estimate total populations of breeding birds. The Grassland is of interest because it provides wildlife habitat and recreational birding opportunities. Indicated breeding pairs were counted on 100-m wide belt transects during morning surveys from late May to early July in 2002 and 2003. We surveyed approximately 6 to 7% of the Grassland each year. The most abundant species in both years were grasshopper sparrow (Ammodramus savannarum), red-winged blackbird (Agelaius phoeniceus), claycolored sparrow (Spizella pallida), Savannah sparrow (Passerculus …

Effects Of Predator Removal On Upland Nesting Ducks In North Dakota Grassland Fragments, Kristen D. Chodachek, Michael J. Chamberlain

The Prairie Naturalist

Low nest success rates in the Prairie Pothole Region are attributed mainly to changes in the predator community coupled with reductions in availability of suitable nesting cover. We evaluated effects of removal of mammalian predators on pair density and nest success of ducks nesting on 259 ha sites in northeastern North Dakota during 2001 and 2002. We monitored pair density and duck nests on 10 sites with removal and 10 sites without removal. Overall nest success for both years was greater on trapped (53.4%) than nontrapped sites (28.7%). Pair densities were not affected by predator removal, but did increase across …

First Record Of The Spurge Hawkmoth As A Pollen Vector For The Western Prairie Fringed Orchid [Notes], Carla R. Jordan, Gerald M. Fauske, Mrion O. Harris, Darla Lenz

The Prairie Naturalist

Identification of pollen vectors is one step in refining management plans for a threatened plant such as the western prairie fringed orchid (Platanthera praeclara Sheviak and Bowles). Pollen vector bionomics, phenology, and ethology must be understood to assess this moth and other potential pollinators relative to orchid reproductive success. Also, the ability of spurge hawkmoth (Lepidoptera: Sphingidae), a recently introduced species, to act as a pollen vector for an obligate prairie plant, the western prairie fringed orchid, in theoretical terms, provides evidence which contradicts long held tenets of one-to-one correspondence between orchids and their pollinators. Further research might shed …

Suggestions For Contributors And Editorial Policy (The Prairie Naturalist), Elmer J. Finck, Hilary Gillock

The Prairie Naturalist

Suggestions for contributors and editorial policy for The Prairie Naturalist from March 2006, Volume 38, Issue 1.

The Prairie Naturalist, Volume 38, Number 1, March 2006, Elmer J. Finck, Hilary Gillock

The Prairie Naturalist

Fire History, Passerine Abundance, and Habitat on a North Dakota Drift Plain Prairie by Timothy J. Ludwick and Robert T. Murphy, pages 1-11

Bats in a Human-made Forest of Central Nebraska by Keith Geluso, pages 13-23

Effects of Predator Removal on Upland Nesting Ducks in North Dakota Grassland Fragments by Kristen D. Chodachek and Michael J. Chamberlain, pages 25-37

Estimates of Breeding Bird Populations in the Sheyenne National Grassland, North Dakota by Mary Ann Cunningham, Douglas H. Johnson, and Daniel N. Svingen, pages 39-56

Notes: First Record of the Spurge Hawkmoth as a Pollen Vector for the western Prairie Fringed …

Fire History, Passerine Abundance, And Habitat On A North Dakota Drift Plain Prairie, Timothy J. Ludwick, Robert K. Murphy

The Prairie Naturalist

Prescribed fire is among key tools for restoring and managing prairies in the northern Great Plains, yet there are no published reports of its impacts on grassland passerine birds on native prairie in the Drift Plain, a major physiographic subregion. We examined relationships between prescribed fire history and abundance and habitat of breeding passerines in Drift Plain prairie at Des Lacs National Wildlife National Refuge in northwestern North Dakota. In 2003, we used point counts (n = 79 75 m radius plots) to survey bird abundance on 16 management units that had been prescribe-burned one to three times each …

Lessons Learned From The St. Francis Dam Failure, J. David Rogers

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The St. Francis Dam (Fig. 1), a curved concrete gravity structure 209-feet high, located in the mountains about 35 miles north of downtown Los Angeles, failed catastrophically near midnight just before March 12, 1928. The failure released 36,180 acre-feet of water down San Francisquito Canyon on a turbulent 55-mile journey to the Pacifica Ocean near Ventura, killing 450 people. As the deadliest American civil engineering failure of the 20th century, the city of Los Angeles paid more than $7 million in restitution to the victims' families and affected landowners. The sudden failure of a new concrete dam constructed by a …

The Local Gromov–Witten Invariants Of Configurations Of Rational Curves, Dagan Karp, Chiu-Chu Melissa Liu, Marcos Mariño

All HMC Faculty Publications and Research

We compute the local Gromov–Witten invariants of certain configurations of rational curves in a Calabi–Yau threefold. These configurations are connected subcurves of the “minimal trivalent configuration”, which is a particular tree of ℙ¹’s with specified formal neighborhood. We show that these local invariants are equal to certain global or ordinary Gromov–Witten invariants of a blowup of ℙ³ at points, and we compute these ordinary invariants using the geometry of the Cremona transform. We also realize the configurations in question as formal toric schemes and compute their formal Gromov–Witten invariants using the mathematical and physical theories of the …

Sneak Preview: Bear River Watershed Historical Digital Collection, Cheryl D. Walters, Cheryl D. Walters

Library Faculty & Staff Publications

Provides early look at a new digital collection assembling image and text resources about the Bear River Watershed in Utah and Idaho.

Tools For The Edge: What’S New For Conserving Carnivores, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

The loss of large carnivores at the edges of parks, preserves, and human habitations threatens the conservation of many species. Thus, effective predation management is a conservation issue, and tools to mitigate conflicts between humans and predators are required. Both disruptive-stimulus (e.g., fladry, Electronic Guards, radio-activated guards) and aversive-stimulus (e.g., electronic training collars, less-than-lethal ammunition) approaches are useful, and technological advances have led to many new, commercially available methods. Evaluating the biological and economic efficiency of these methods is important. However, social and psychological effects should also be considered. The management of animal damage to human property is necessary, and …

Influence Of Fish Stocking Density On The Foraging Behavior Of Double-Crested Cormorants, Phalacrocorax Auritus, Scott J. Werner, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Protecting The Flying Public And Minimizing Economic Losses Within The Aviation Industry: Technical And Direct Management Assistance Provided By Usda Wildlife Services At Airports To Reduce Wildlife Hazards Fiscal Year 2005, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Biologists with USDA Wildlife Services provided technical and operational assistance at a record 674 airports and military airbases in FY 2005 to reduce wildlife hazards to aviation. Operational assistance included live-trapping birds of prey, such as this juvenile red-tailed hawk, at 65 airports. Captured birds were released in areas away from the airports. Studies have shown that juvenile (nonbreeding) red-tailed hawks rarely return to airports after translocation. The overall red-tailed hawk population in the USA has increased over 2-fold since 1970. The population in the Great Lakes region has increased over 3-fold.

Wsdl-S: Specification, Tools, Use Cases And Applications, Amit P. Sheth, Kunal Verma, Karthik Gomadam

Kno.e.sis Publications

No abstract provided.

Nanometal Containing Nanocomposites And Photolithographic Polyaniline Nanofibers, Frank D. Blum, Sunil K. Pillalamarri, Lalani K. Werake, J. Greg Story, Massimo F. Bertino, Akira Tokuhiro

Chemistry Faculty Research & Creative Works

A report on recent progress from our laboratories on the nanostructures produced from novel synthesis techniques will be discussed. Using high-energy radiation (γ-rays) we have been able to produce conducting polymer nanofibers and nanorods of polyaniline and polypyrrole without the use of a separate template or capping agent. This technique has been extended, with the addition of metal ions, to a "one pot" synthesis, producing conducting nanocomposites. These nanocomposites contain metal nanoparticles which decorate the conducting nanofibers. We have also recently shown that these systems can be photopatterned to produce novel structures. We believe that these systems will be useful …

Existence Of Explosive Solutions To Non-Monotone Semilinear Elliptic Equations, Zachary H. Proano

Theses and Dissertations

We consider the semilinear elliptic equation Δu = p(x)f(u) on a domain ­ Ω ⊆ Rⁿ, n ≥ 3, where f is a nonnegative function which vanishes at the origin and satisfies g₁ ≤ f ≤ g₂ where g₁; g₂ are nonnegative, nondecreasing functions which also vanish at the origin, and p is a nonnegative continuous function with the property that any zero of p is contained in a bounded domain in ­ such that p is positive on its boundary. For Ω­ bounded, we show that a nonnegative solution u satisfying u(x) …

Radiotelemetry And Behavioral Ecology Of Neonate Southern Pacific Rattlesnakes, Alex Figueroa

Loma Linda University Electronic Theses, Dissertations & Projects

By externally glueing radiotransmitters to the dorsoposterior surface of seven neonate Southern Pacific Rattlesnakes, Crotalus oreganus helleri, I monitored the behavior and ecology of this understudied age-class and species. As an alternative to surgical implantation, external transmitter attachment was less invasive, permitted frequent transmitter replacement, and did not appear to affect neonate behavior. Five neonates tracked through several transmitter replacements (48-125 d) increased 10-38% in mass, indicating successful foraging. Neonates predominately occupied grasslands and coastal sage scrub habitats. Ambush postures were frequently established near rodent features (burrows and runways). Unlike adults, the neonates frequently used arboreal positions (10% of 144 …

Magnetic Ordering In Gd Monopnictides: Indirect Exchange Versus Superexchange Interaction, Chun-Gang Duan, Renat F. Sabirianov, Wai-Ning Mei, Peter Dowben, Sitaram Jaswal, Evgeny Y. Tsymbal

Physics Faculty Publications

The exchange interaction parameters of Gd monopnictides are deduced from fitting the total energies of different magnetic configurations to those computed within the Heisenberg model. The magnetic structures predicted by first-principles calculations as well as the Curie (Néel) temperatures obtained from Monte Carlo simulations are both in good agreement with experiments. A detailed analysis of the exchange parameters suggests that the Ruderman-Kittel-Kasuya-Yosida-type indirect exchange interactions and antiferromagnetic superexchange interactions coexist in these compounds. The magnetic order changes from ferromagnetic in GdN to antiferromagnetic in other Gd pnictides as a result of the increased ionic radius of a pnictide in the …

Nonlocal Effects On Optical And Molecular Interactions With Metallic Nanoshells, P.T. Leung, Railing Chang

Physics Faculty Publications and Presentations

Theoretical studies of the optical response of metallic nanoshells have been carried out, where quantum effects are partially accounted for through the application of a nonlocal response model for shells of mesoscopic dimensions. Both far field and near field interactions are considered, with the incident source being a plane wave and an emitting molecular dipole, respectively. It is found that these nonlocal effects can lead to significant deviations from macroscopic electrodynamic theory, for shells of ultrasmall dimensions (nm) or ultrathin thickness (~1 nm), and are particularly significant for processes involving higher multipolar responses of the nanoshells. It is further concluded …

Doppler-Only Multistatic Radar, Dustin G. Mixon

Theses and Dissertations

In order to estimate the position and velocity of a target, most multistatic radar systems require multiple independent target measurements, such as angle-of-arrival, time-of-arrival, and Doppler information. Though inexpensive and reliable, Doppler-only systems have not been widely implemented due to the inherent nonlinear problem of determining a target’s position and velocity from their measurements. We solve this problem. In particular, we first establish the lack of observability in the Doppler-only bistatic system, thereby demonstrating the need for multiple transmitters and/or receivers. Next, for a multistatic system with a sufficient number of transmitter-receiver pairs, we invoke classical optimization techniques, such as …

Cryptanalysis Of Pseudorandom Number Generators In Wireless Sensor Networks, Kevin M. Finnigin

Theses and Dissertations

This work presents a brute-force attack on an elliptic curve cryptosystem implemented on UC Berkley's TinyOS operating system for wireless sensor networks. The attack exploits the short period of the pseudorandom number generator (PRNG) used by the cryptosystem to generate private keys. The attack assumes a laptop is listening promiscuously to network traffic for key messages and requires only the sensor node?s public key and network address to discover the private key. Experimental results show that roughly 50% of the address space leads to a private key compromise in 25 minutes on average. Furthermore, approximately 32% of the address space …

Active Optical Tracking With Spatial Light Modulators, Steven R. Mawhorter

Theses and Dissertations

Two spatial light modulators are utilized for beam splitting, steering and tracking. Both linear and holographic phase screens are used in a demonstration of technology to allow real time tracking to communicate in a one-to-several type scenario. One SLM is used to apply a linear phase modulation to steer multiple beams onto a detector. The spots that are produced represent the targets as they move around the field of view of the central communication node. A Gerchberg-Saxton algorithm will subsequently use the detected spots as the desired pointing locations. Using this as input, the Gerchberg-Saxton algorithm yields a phase only …

Control Demonstration Of A Thin Deformable In-Plane Actuated Mirror, Gina A. Peterson

Theses and Dissertations

Current imaging satellites are limited in resolution and coverage area by the aperture size of their primary optical mirror. To get a large optical mirror into space, current launch weight and size restrictions must be overcome. Membrane-like optical mirrors can overcome these restrictions with their very lightweight and flexible properties. However, thin, deformable membrane mirrors are very susceptible to the space environment and require active control for surface stabilization and shaping. The primary goal of this research is to demonstrate that an in-plane actuated membrane-like deformable optical mirror can be controlled to optical wavelength tolerances in a closed-loop system. Fabrication …

Bifurcations And Competing Coherent Structures In The Cubic-Quintic Ginzburg-Landau Equation I: Plane Wave (Cw) Solutions, S.C. Mancas, S. Roy Choudhury

Publications

Singularity Theory is used to comprehensively investigate the bifurcations of the steady-states of the traveling wave ODEs of the cubic-quintic Ginzburg-Landau equa- tion (CGLE). These correspond to plane waves of the PDE. In addition to the most general situation, we also derive the degeneracy conditions on the eight coefficients of the CGLE under which the equation for the steady states assumes each of the possible quartic (the quartic fold and an unnamed form), cubic (the pitchfork and the winged cusp), and quadratic (four possible cases) normal forms for singularities of codimension up to three. Since the actual governing equations are …

Hydrodynamic Mediation Of Density-Dependent Growth And Adult-Juvenile Interactions Of A Spionid Polychaete, Brent T. Hentschel, Amy A. Larson

Environmental Science and Management Faculty Publications and Presentations

Abstract We performed an experiment to test the effects of adult density on the growth rates of juvenile Polydora cornuta. Our experiment was performed in three identical counter-rotating annular flumes, each set to one of three different flow speeds for a period of 3 d (U 5mm = 3, 6, or 12 cm s^-1 , where U_5mm = velocity measured 5 mm above bottom). We implanted replicate vials containing a premeasured juvenile P. cornuta and either 0, 2, or 5 adults into a 2-cm layer of sediment in the flume. The relative growth rates of the juveniles …

Nmr Studies Of Escherichia Coli Acyl Carrier Protein: Dynamic And Structural Differences Of The Apo- And Holo-Forms, Yangmee Kim, Evgueni Kovriguine, Ziad Eletr

Chemistry Faculty Research and Publications

Two indicators of conformational variability of Escherichia coli acyl carrier protein (ACP) have been investigated, namely backbone dynamics and chemical shift variations of ACP. Hydrophobic interactions between the 4′-PP prosthetic group and the hydrophobic pocket enclosed by the amphipathic helices resulted in chemical shift perturbations in the residues near the prosthetic group binding sites and contact sites in the hydrophobic pockets upon conversion from apo- to holo-forms. At pH 7.9, destabilization of ACP due to negative charge repulsions and the deprotonated state of His 75 resulted in observed chemical shift changes in the C-terminal region. Model-free analysis showed that the …

Orientational Disorder In Sodium Cadmium Trifluoride Trihydrate, Nacdf3·3h2o, Robert W. Smith, Arthur Mar, Jianjun Liu, Stan Schnell, John R. Hardy

Chemistry Faculty Publications

Attempts to synthesize the hypothetical anhydrous fluoroperovskite NaCdF₃, which has been predicted to be stable, resulted instead in a hydrated fluoride of nominal composition NaCdF₃·3H₂O. It decomposes to sodium fluoride, cadmium fluoride, and water at 60 °C. Its structure has been determined by single-crystal X-ray diffraction. Na_0.92(2)Cd_1.08F_3.08·2.92H₂O crystallizes in the cubic space group with a = 8.2369(4) Å and Z = 4. The structure is based on the NaSbF₆-type (an ordered variant of the ReO₃-type) and features tilted sodium- and cadmium-centred octahedra …

Reflection Of A Wave Off A Surface, Brendan Guilfoyle, Wilhelm Klingenberg

Preprints

Recent advances in twistor theory are applied to geometric optics in R 3 . The general formulae for reflection of a wavefront in a surface are derived and in three special cases explicit descriptions are provided: when the reflecting surface is a plane, when the incoming wave is a plane and when the incoming wave is spherical. In each case particular examples are computed exactly and the results plotted to illustrate the outgoing wavefront.

[O Iii] Profile Substructure In Radio-Quiet Quasars, C. Leipski, N. Bennert

Physics

Interactions between the radio jet and the optical emission of the narrow-line region (NLR) are a well known phenomenon in Seyfert galaxies. Here, we present the study of possible jet-NLR interactions in five radio-quiet PG quasars with double or triple radio structure. High spatial and spectral resolution observations were carried out in the H-[O III] 5007 wavelength range. In all cases, there is evidence for [O III] profile substructure (shoulders, subpeaks, blueshifted "broad'' components) with different clarity. To measure the velocity, line width, intensity, and location of these [O III] components, several Gaussians were fitted. Often, the substructures are more …

Asynchronous Random Boolean Network Model With Variable Number Of Parents Based On Elementary Cellular Automata Rule 126, Mihaela Teodora Matache

Mathematics Faculty Publications

A Boolean network with N nodes, each node’s state at time t being determined by a certain number of parent nodes, which can vary from one node to another is considered. This is a generalization of previous results obtained for a constant number of parent nodes, by Matache and Heidel in Asynchronous random Boolean network model based on elementary cellular automata rule 126, Phys. Rev. E 71, 026232, 2005. The nodes, with randomly assigned neighborhoods, are updated based on various asynchronous schemes. The Boolean rule is a generalization of rule 126 of elementary cellular automata, and is assumed to be …