Physical Sciences and Mathematics Commons^™

Relationships Between Surface And Column Aerosol Radiative Properties And Air Mass Transport At A Rural New England Site, J F. Slater, Jack E. Dibb

Earth Sciences

Chemical, physical, and radiative properties of surface and vertical column aerosols were measured at a rural site in southern New Hampshire from July 2000 to September 2001. The primary objective was to determine how intensive and extensive aerosol properties vary in air masses originating in different upwind regions. The data set also allows for an investigation of some of the relationships between surface and column aerosol properties at the site, and provides an estimate of direct radiative forcing by aerosols during the study period. Extensive properties (e.g., optical depth and chemical concentration) were at maximum values during times of south-southwest …

Asian Dust Storm Events Of Spring 2001 And Associated Pollutants Observed In New England By The Atmospheric Investigation, Regional Modeling, Analysis And Prediction (Airmap) Monitoring Network, Linsey J. Debell, Marcy Vozzella, R. Talbot, Jack E. Dibb

Earth Sciences

Between 18 April and 13 May 2001, three statistically extreme dust aerosol events were observed across the entire northeastern United States. High levels of bulk aerosol water-soluble Ca²⁺ (range = 42–482 pptv) and PM_2.5 elemental Ca (range = 19–156 pptv) were observed simultaneously at Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) and Interagency Monitoring of Protected Visual Environments (IMPROVE) stations. On the basis of Ca²⁺ concentrations, the average bulk dust concentration for all events across all four AIRMAP stations was estimated to be 7.4 μg/m³. There was no evidence of dust outbreaks in North …

The Melting Lines Of Model Silicon Calculated From Coexisting Solid–Liquid Phases, S. Yoo, Xiao Cheng Zeng, James R. Morris

Xiao Cheng Zeng Publications

The melting line is an important thermodynamic property of materials and can be calculated via computer simulation, given the intermolecular potential for the materials. Conventionally, the free-energy method has been mainly employed to calculate the melting line. Alternatives to the free-energy method for calculating the melting line include simulation of the solid-liquid coexistence and nonequilibrium molecular dynamics (MD) method. Recently, one of us (Morris) and Song reported a detailed simulation procedure to calculate the melting line of the Lennard-Jones system. Specifically, the MD simulation consists of a preparation run and a production run. In the preparation run, the liquid and …

Energy Conserving Approximations To The Quantum Potential: Dynamics With Linearized Quantum Force, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

Solution of the Schrödinger equation within the de Broglie–Bohm formulation is based on propagation of trajectories in the presence of a nonlocal quantum potential. We present a new strategy for defining approximate quantum potentials within a restricted trial function by performing the optimal fit to the log-derivatives of the wave function density. This procedure results in the energy-conserving dynamics for a closed system. For one particular form of the trial function leading to the linear quantum force, the optimization problem is solved analytically in terms of the first and second moments of the weighted trajectory distribution. This approach gives exact …

High-Precision Lattice Qcd Confronts Experiment, James E. Hetrick, C. T. Davies

All Faculty Articles - School of Engineering and Computer Science

The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test this formalism, we compare experiment with a variety of nonperturbative calculations in QCD drawn from a restricted set of “gold-plated” quantities. We find agreement to within statistical and systematic errors of 3% or less. We discuss the implications for phenomenology and, in particular, for heavy-quark physics.

Dense Nonaqueous Phase Liquid (Dnapl) Source Zone Characterization: Influence Of Hydraulic Property Correlation On Predictions Of Dnapl Infiltration And Entrapment, Lawrence D. Lemke, Linda M. Abriola, Pierre Goovaerts

Environmental Science and Geology Faculty Research Publications

The influence of aquifer property correlation on multiphase fluid migration and entrapment was explored through the use of correlated and uncorrelated porosity, permeability, and capillary pressure-saturation (P_c-Sat) parameter fields in a crosssectional numerical multiphase flow model. Data collected from core samples in a nonuniform sandy aquifer were used to generate three-dimensional aquifer parameter fields. Porosity was assumed to be uniform or simulated using sequential Gaussian simulation (SGS). Permeability (k) was modeled independently of porosity using SGS as well as simulated geostatistical indicator classes derived from measured grain size distribution curves. Retention characteristics were assigned employing Leverett …

Climatology Of Katabatic Winds In The Mcmurdo Dry Valleys, Southern Victoria Land, Antarctica, Thomas H. Nylen, Andrew G. Fountain, Peter T. Doran

Geography Faculty Publications and Presentations

Katabatic winds dramatically affect the climate of the McMurdo dry valleys, Antarctica. Winter wind events can increase local air temperatures by 30°C. The frequency of katabatic winds largely controls winter (June to August) temperatures, increasing 1°C per 1% increase in katabatic frequency, and it overwhelms the effect of topographic elevation (lapse rate). Summer katabatic winds are important, but their influence on summer temperature is less. The spatial distribution of katabatic winds varies significantly. Winter events increase by 14% for every 10 km up valley toward the ice sheet, and summer events increase by 3%. The spatial distribution of katabatic frequency …

Overlap Bias In The Case-Crossover Design, With Application To Air Pollution Exposures, Holly Janes, Lianne Sheppard, Thomas Lumley

UW Biostatistics Working Paper Series

The case-crossover design uses cases only, and compares exposures just prior to the event times to exposures at comparable control, or “referent” times, in order to assess the effect of short-term exposure on the risk of a rare event. It has commonly been used to study the effect of air pollution on the risk of various adverse health events. Proper selection of referents is crucial, especially with air pollution exposures, which are shared, highly seasonal, and often have a long term time trend. Hence, careful referent selection is important to control for time-varying confounders, and in order to ensure that …

A Study In Modeling Low-Conservation Protein Superfamilies, Chang Wang, Stephen Scott, Jun Zhang, Qingping Tao, Dmitri E. Fomenko, Vadim N. Gladyshev

CSE Technical Reports

We present several algorithms for identification of new proteins in superfamilies with low primary sequence conservation. The low conservation of primary sequence in protein superfamilies such as Thioredoxin-fold (Trxfold) makes conventional methods such as hidden Markov models (HMMs) difficult to use. Therefore, we use structural properties to build our classifiers. These structural properties include secondary structure patterns as well as various properties of the residues in the protein sequences. We use this information to model proteins via hidden Markov models, support vector machines and algorithms in the multiple-instance learning model. In 20-fold jackknife tests, some of our models performed well, …

High-Resolution Chandra Spectroscopy Of Gamma Cassiopeiae (B0.5e), M. A. Smith, David H. Cohen, M. F. Gu, R. D. Robinson, N. R. Evans, Prudence G. Schran

Physics & Astronomy Faculty Works

gamma Cas is the prototypical classical B0.5e star and is now known to be the primary in a wide binary system. It has long been famous for its unique hard X-ray characteristics, among which are variations that correlate with changes in a number of optical light and UV line and continuum properties. These peculiarities have led to a picture in which processes on or near the Be star produce the observed X-ray emission. In this paper we report on a 53 ks Chandra High Energy Transmission Grating Spectrometer observation of this target. An inspection of our spectrum shows that it …

Testing Protoplanetary Disk Alignment In Young Binaries, Eric L.N. Jensen, R. D. Mathieu, A. X. Donar, Allyn Dullighan , '01

Physics & Astronomy Faculty Works

We present K-band (2.2 mum) imaging polarimetry that resolves 19 T Tauri binary and multiple systems in the Taurus-Auriga and Scorpius-Ophiuchus star-forming regions. We observed systems with projected separations 1."5 - 7."2 (similar to200 - 1000 AU) in order to determine the relative orientation of the circumstellar disks in each binary system. Scattered light from these disks is polarized, allowing us to deduce the position angle of the disk on the sky from the position angle of polarization even though our observations do not resolve the disks themselves. We detected measurable polarization ( typically 0.5% - 2%, with typical uncertainty …

Tool Support For Two-Tiered Architectural Design For Automotive Control Systems, Kevin Steppe, Greg Bylenok, David Garlan, Bradley Schmerl, Kanat Abirov, Nataliya Shevchenko

Research Collection School Of Computing and Information Systems

An attractive approach to architecture-based design is to structure the development process into two tiers. The top tier represents the abstract design (or architecture) of a system in terms of abstract components. The bottom tier refines that design by making specific implementation decisions, such as platform, middleware, and component implementations. While attractive in principle, there has been relatively little industrial-based experience to shed light on problems and solutions involved in such an approach. In this paper we describe our experience in developing tools to introduce a two-tiered model-based approach to the design of Ford Motor Company’s automotive control systems, highlighting …

Development Of A Fourier Transform-Based Time-Of-Flight Electron Spectrometer With Ultra-High Resolution, Brian Frederick, Peter H. Kleban

University of Maine Office of Research Administration: Grant Reports

This project, funded by the Major Research Instrumentation program, will develop a time-of-flight electron velocity analyzer using advanced modulation and Fourier deconvolution techniques with a throughput advantage on the order of 1000 over existing instruments. The new spectrometer will operate with ultra-high resolution in the energy range 1-1000 electron volts. It will be useful for the investigation of surface properties under ultra-high vacuum and a variety of other scientific and commercial applications. The device utilizes secondary chopping of the electron beam in the nanosecond or sub-nanosecond time regime, and state-of-the-art Fourier transform-based digital signal recovery methods. Additionally, there is potential …

Are Half-Metallic Ferromagnets Half Metals? (Invited), Peter A. Dowben, Ralph Skomski

Peter Dowben Publications

Several classes of materials are currently under investigation as potential high-spin-polarization materials. Unfortunately, the proposed half-metallic materials, including the semi-Heusler alloys, the manganese perovskites, and the "simpler" oxides such as chromium dioxide and magnetite, suffer from fundamental limitations. First, the postulated half-metallic systems lose their full (T = 0) spin polarization at finite temperatures and, second, surfaces, interfaces, and structural inhomogenities destroy the complete spin polarization of half-metallic systems even at zero temperature. In a strict sense, half-metallic ferromagnetism is limited to zero temperature since magnon and phonon effects lead to reductions in polarization at finite temperatures. ©2004 American Institute …

Magmatic To Solid-State Fabric Transition In A Post-Tectonic Tonalite Pluton, Scott E. Johnson

University of Maine Office of Research Administration: Grant Reports

Magma chambers are an essential component in the construction of oceanic and continental lithosphere, and profoundly influence the thermal and mechanical behavior of the crust and mantle. The mechanical properties of a magma chamber change during cooling and crystallization, as accommodation of deformation changes from magmatic flow to solid-state processes. Thus, to understand the thermo-mechanical evolution of magma chambers, it is crucial to understand the relative importance of magmatic and solid-state flow, and the nature of the transition between them. This project is investigating such a transition preserved in the San Jose pluton, Baja California, Mexico. The pluton postdates the …

Superferromagnetic Domain State Dynamics In Discontinuous Cofe/Al2o3, Christian Binek

Christian Binek Publications

Magnetization hysteresis and AC susceptibility measurements were performed on the discontinuous metal–insulator multilayer [Co80Fe20(1.4 nm)/Al2O3(3 nm)]10. CoFe forms ferromagnetic single-previous domain term particles being embedded in the Al2O3 matrix. Due to strong dipolar inter-particle interactions a “previous superferromagnetic term” correlation of particle moments was previously stated. The dynamical magnetic properties of the superferromagnet can be understood in the framework of previous domain term wall motion in an impure ferromagnet. Kinetic simulations are employed, which are based on field and temperature-dependent previous domain term wall velocities. The magnetization hysteresis as well as the AC susceptibility, χ′−iχ′′, are calculated and compared to …

Surface Deformations As Indicators Of Deep Ebullition Fluxes In A Large Northern Peatland, P. H. Glaser, J. P. Chanton, P. Morin, D. O. Rosenberry, D. I. Siegel, O. Ruud, L. I. Chasar, Andrew S. Reeve

Earth Science Faculty Scholarship

Peatlands deform elastically during precipitation cycles by small (+/- 3 cm) oscillations in surface elevation. In contrast, we used a Global Positioning System network to measure larger oscillations that exceeded 20 cm over periods of 4 - 12 hours during two seasonal droughts at a bog and fen site in northern Minnesota. The second summer drought also triggered 19 depressuring cycles in an overpressured stratum under the bog site. The synchronicity between the largest surface deformations and the depressuring cycles indicates that both phenomena are produced by the episodic release of large volumes of gas from deep semi-elastic compartments confined …

Greenpass: Flexible And Scalable Authorization For Wireless Networks, Sean Smith, Nicholas C. Goffee, Sung Hoon Kim, Punch Taylor, Meiyuan Zhao, John Marchesini

Computer Science Technical Reports

Wireless networks break the implicit assumptions that supported authorization in wired networks (that is: if one could connect, then one must be authorized). However, ensuring that only authorized users can access a campus-wide wireless network creates many challenges: we must permit authorized guests to access the same network resources that internal users do; we must accommodate the de-centralized way that authority flows in real universities; we also must work within standards, and accommodate the laptops and systems that users already have, without requiring additional software or plug-ins.

This paper describes our ongoing project to address this problem, using SPKI/SDSI delegation …

Invariant Currents And Dynamical Lelong Numbers, Dan Coman, Vincent Guedj

Mathematics - All Scholarship

Let f be a polynomial automorphism of C^k of degree lamda, whose rational extension to P^k maps the hyperplane at infinity to a single point. Given any positive closed current S on Pk of bidegree (1,1), we show that the sequence lamda−ⁿ(fⁿ)*S converges in the sense of currents on P^k to a linear combination of the Green current T₊ of f and the current of integration along the hyperplane at infinity. We give an interpretation of the coefficients in terms of generalized Lelong numbers with respect to an invariant dynamical current for …

Water Absorption And Dielectric Changes In Crystalline Poly(Vinylidene Fluoride-Trifluoroethylene) Copolymer Films, P.A. Jacobson, Luis G. Rosa, Christina M. Othon, Kristin L. Kraemer, A.V. Sorokin, Stephen Ducharme, Peter A. Dowben

Peter Dowben Publications

Crystalline Langmuir–Blodgett copolymer films of vinylidene fluoride with trifluoroethylene (70%:30% and 80%:20%) absorb water. Water absorption is accompanied by film swelling, as indicated by an increase in lattice spacing, sometimes by as much as 5%. This water absorption, between 0 and 40 °C, is a result of intercalation or occupation of interstitial sites between the layers of the film, not just water molecules filling voids and defect sites alone. An increase in the film capacitance is observed, although the polymer chains retain all trans configuration of the ferroelectric phase. © 2004 American Institute of Physics.

Hypothetical Thermodynamic Properties: The Boiling And Critical Temperatures Of Polyethylene And Polytetrafluoroethylene, James S. Chickos

James Chickos

No abstract provided.

Extrinsic Control Of The Exchange Bias, Christian Binek

Christian Binek Publications

A new control mechanism for the exchange bias effect in magnetic heterostructures is proposed. It takes advantage of the magnetoelectric effect which takes place in the antiferromagnetic pinning layer. In contrast with the pioneering AC measurements of the magnetoelectric effect, we investigate the magnetic response of the prototypical magnetoelectric compound Cr2O3 on static electric fields. The linear dependence of the magnetic moment on the applied axial electric field and the temperature dependence of the corresponding slopes αshort parallel are measured by DC SQUID magnetometry. The contribution of the field-induced surface magnetization and its impact on the exchange bias effect is …

Measures Of Concordance Of Polynomial Type, Heather Edwards

Electronic Theses and Dissertations

A measure of concordance, $\kappa$, is of polynomial type if and only if $\kappa (tA+(1-t)B)$ is a polynomial in $t$ where $A$ and $B$ are 2-copulas. The degree of such a type of measure of concordance is simply the highest degree of the polynomial associated with $\kappa$. In previous work [2], [3], properties of measures of concordance preserving convex sums (equivalently measures of concordance of polynomial type degree one) were established; however, a characterization was not made. Here a characterization is made using approximations involving doubly stochastic matrices. Other representations are provided from this characterization leading naturally to two interpretations …

Study Of The Excited-State Absorption Properties Of Polymethine Molecules, Richard Stanley Lepkowicz

Electronic Theses and Dissertations

This dissertation investigates excited-state nonlinearities in a series of polymethine dyes for the application of nanosecond optical limiting. Optical limiters are devices that for low intensity light exhibit a high linear transmittance, but for high intensity light strongly attenuate the incident radiation. These devices would serve to protect optical sensors from intense laser radiation by clamping the maximum energy allowed through an optical system below the damage threshold of the sensor. The search is ongoing for optical materials that are both broadband and have high damage thresholds to be effective materials for limiting applications. Polymethine dyes are promising compounds due …

Camera System Support For Highway Transportation Using Mobile Devices, Le Minh

Electronic Theses and Dissertations

With the very fast growing technology in wireless, advancement in hardware and the dramatically falling cost of mobile computing devices such as PDA, handheld device, People nowadays can have a personal device that fits in their hand but has computing power as a desktop did few years ago. The same device now is able to communicate over a wireless network and view office document at the same time. The combination of size, power and flexibility makes the personal devices increasingly appear in many aspects of life. In this proposal, we focus on a simple yet useful application of mobile devices …

Methods Development And Application Of Two Dimensional Chromatography And Tandem Mass Spectrometry In Proteomics, Brett Romain Wenner

University of Kentucky Doctoral Dissertations

Although molybdenum blue solutions have been known for more than twocenturies, an understanding of their chemical nature is only beginning to emerge.This dissertation aimed at elucidating the structural nature of the polydisperse,nanoscopic components in the solution phases and the solid states of partiallyreduced polyoxomolybdate (Mo-POM). The study offered at least fourcontributions to the area: (1) a rational protocol for the molecular recognition ofMo-POM with de novo organic hosts. (2) demonstration of kinetic precipitation ofa dynamic mixture of polyoxomolybdates and application of the technique to thestudy of the dynamic mixture by TEM (3) characterization of the Mo-POMnanostructures by an unusual combination …

Bidirectional Lao* Algorithm (A Faster Approach To Solve Goal-Directed Mdps), Venkata Deepti Kiran Bhuma

University of Kentucky Master's Theses

Uncertainty is a feature of many AI applications. While there are polynomial-time algorithms for planning in stochastic systems, planning is still slow, in part because most algorithms plan for all eventualities. Algorithms such as LAO* are able to find good or optimal policies more quickly when the starting state of the system is known.

In this thesis we present an extension to LAO*, called BLAO*. BLAO* is an extension of the LAO* algorithm to a bidirectional search. We show that BLAO* finds optimal or ^_E-optimal solutions for goal-directed MDPs without necessarily evaluating the entire state space. BLAO* …

Solvent-Free Conversion Of Alpha-Naphthaldehyde To 1-Naphthoic Acid And 1-Naphthalenemethanol: Application Of The Cannizzaro Reaction, John J. Esteb, Keith M. Glogorich, Stacey A. O'Reilly

Scholarship and Professional Work - LAS

The Cannizzaro reaction is routinely covered in organic textbooks, but owing to the shortage of suitable procedures for the undergraduate teaching laboratory, this reaction is seldom performed in a first-year organic chemistry class. In this experiment, powdered potassium hydroxide and α-naphthaldehyde are heated under solvent-free conditions to produce 1-naphthoic acid and 1-naphthalenemethanol in 86% and 79% yields, respectively. The solvent-free nature of this procedure greatly reduces the quantity of waste generated by students relative to the typical solvent-based method of preparation. Note:Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information …

Geology And Paleontology Of The Upper John Day Beds, John Day River Valley, Oregon: Lithostratigraphic And Biochronologic Revision In The Haystack Valley And Kimberly Areas (Kimberly And Mt. Misery Quadrangles), Robert M. Hunt Jr., Ellen Stepleton

Department of Earth and Atmospheric Sciences: Faculty Publications

The John Day Formation of north-central Oregon preserves a succession of speciose, superposed Oligocene through early Miocene mammalian faunas that establish the sequence of mid-Cenozoic mammalian evolution within the Pacific Northwest. Upper John Day rock units initially described by Merriam (1900, 1901) in the Kimberly and Haystack Valley areas were later divided into lower (Kimberly) and upper (Haystack Valley) members by Fisher and Rensberger (1972). We focused our study on the lithostratigraphic succession within the Haystack Valley Member. Rocks previously included in the Haystack Valley Member can be subdivided into four unconformity-bounded, genetic lithostratigraphic units that range in age from …

Do Meteorologists Suppress Thunderstorms? Radar-Derived Statistics And The Behavior Of Moist Convection, Matthew D. Parker, Jason C. Knievel

Department of Earth and Atmospheric Sciences: Faculty Publications

Most meteorologists are acquainted with the notion of a weather hole—that is, a place that receives less exciting weather than does its surroundings. Exciting weather takes many forms, but when people use the term weather hole, they tend to mean a place that thunderstorms often barely miss, or near which approaching storms often dissipate. For this paper, that is the meaning we adopt.

In our experience, many meteorologists and lay weather enthusiasts genuinely believe that they live in weather holes, and this belief, almost without fail, seems to stem from countless hours spent gazing at displays of radar reflectivity. We …