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2009

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Articles 841 - 870 of 7616

Full-Text Articles in Physical Sciences and Mathematics

Modeling Multilevel Sleep Transitional Data Via Poisson Log-Linear Multilevel Models, Bruce J. Swihart Oct 2009

Modeling Multilevel Sleep Transitional Data Via Poisson Log-Linear Multilevel Models, Bruce J. Swihart

COBRA Preprint Series

This paper proposes Poisson log-linear multilevel models to investigate population variability in sleep state transition rates. We specifically propose a Bayesian Poisson regression model that is more flexible, scalable to larger studies, and easily fit than other attempts in the literature. We further use hierarchical random effects to account for pairings of individuals and repeated measures within those individuals, as comparing diseased to non-diseased subjects while minimizing bias is of epidemiologic importance. We estimate essentially non-parametric piecewise constant hazards and smooth them, and allow for time varying covariates and segment of the night comparisons. The Bayesian Poisson regression is justified …


Integration And Deployment Techniques In Combination With Development Methodologies, Brian E. Nesbitt Oct 2009

Integration And Deployment Techniques In Combination With Development Methodologies, Brian E. Nesbitt

Regis University Student Publications (comprehensive collection)

Efficient and inefficient pairings of software development methodologies and software integration and deployment techniques exist. Often times the automation of code integration and deployment is chosen but the full benefit of these technologies are throttled by the incorporation of a development methodology. It can be hypothesized that the evolution of software development created this situation along with the latency of implementing development methodologies. This work examines four scenarios comprised of traditional and conventional development methodologies with manual and automated software integration and deployment techniques. Similar web-based software applications were selected from waterfall (traditional) and agile (conventional) run project development teams. …


Radiatively Induced Lorentz And Gauge Symmetry Violation In Electrodynamics With Varying Alph A, Alejandro Ferrero, Brett David Altschul Oct 2009

Radiatively Induced Lorentz And Gauge Symmetry Violation In Electrodynamics With Varying Alph A, Alejandro Ferrero, Brett David Altschul

Faculty Publications

A time-varying fine structure constant α(t) could give rise to Lorentz- and CPT-violating changes to the vacuum polarization, which would affect photon propagation. Such changes to the effective action can violate gauge invariance, but they are otherwise permitted. However, in the minimal theory of varying α, no such terms are generated at lowest order. At second order, vacuum polarization can generate an instability—a Lorentz-violating analogue of a negative photon mass squared −m2γ∝α(˙α2α)2log(Λ2), where Λ is the cutoff for the low-energy effective theory.


Giant Plasmonic Energy And Momentum Transfer On The Nanoscale, Maxim Durach Oct 2009

Giant Plasmonic Energy And Momentum Transfer On The Nanoscale, Maxim Durach

Physics and Astronomy Dissertations

We have developed a general theory of the plasmonic enhancement of many-body phenomena resulting in a closed expression for the surface plasmon-dressed Coulomb interaction. It is shown that this interaction has a resonant nature. We have also demonstrated that renormalized interaction is a long-ranged interaction whose intensity is considerably increased compared to bare Coulomb interaction over the entire region near the plasmonic nanostructure. We illustrate this theory by re-deriving the mirror charge potential near a metal sphere as well as the quasistatic potential behind the so-called perfect lens at the surface plasmon (SP) frequency. The dressed interaction for an important …


Dispersion Interactions Between Optically Anisotropic Cylinders At All Separations: Retardation Effects For Insulating And Semiconducting Single-Wall Carbon Nanotubes, Roger H. French Oct 2009

Dispersion Interactions Between Optically Anisotropic Cylinders At All Separations: Retardation Effects For Insulating And Semiconducting Single-Wall Carbon Nanotubes, Roger H. French

Faculty Scholarship

We derive the complete form of the van der Waals dispersion interaction between two infinitely long anisotropic semiconducting/insulating thin cylinders at all separations. The derivation is based on the general theory of dispersion interactions between anisotropic media as formulated in Munday et al. [Phys. Rev. A 71, 042102 (2005)]. This formulation is then used to calculate the dispersion interactions between a pair of single-walled carbon nanotubes at all separations and all angles. Nonretarded and retarded forms of the interactions are developed separately. The possibility of repulsive dispersion interactions and nonmonotonic dispersion interactions is discussed within the framework of the formulation.


Magnetic And Petrologic Characterization Of Synthetic Martian Basalts And Implications For The Surface Magnetization Of Mars, Julie A. Bowels, Julie E. Hammer, Stefanie A. Brachfeld Oct 2009

Magnetic And Petrologic Characterization Of Synthetic Martian Basalts And Implications For The Surface Magnetization Of Mars, Julie A. Bowels, Julie E. Hammer, Stefanie A. Brachfeld

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

A suite of synthetic Martian basalts is generated with the objective of providing fundamental material properties data for use in modeling and interpretation of mission data. We systematically evaluate the effects of major element composition, oxygen fugacity (ƒO2), and cooling rate on phase chemistry and magnetic mineralogy, grain size, and intensity of remanent magnetization. The range of experimental compositions and ƒO2 are chosen to bracket the range expected in the Martian crust; our results should therefore span the range of possible mineralogies, textures, and magnetic properties in rapidly cooled Mars crustal materials. Two starting compositions are used for the sample …


A Spectroscopically Confirmed Excess Of 24 Μm Sources In A Super Galaxy Group At Z=0.37: Enhanced Dusty Star Formation Relative To The Cluster And Field Environment, Kim-Vy H. Tran, Amelie Saintonge, John Moustakas, Lei Bai, Anthony H. Gonzalez, Bradford P. Holden, Dennis Zaritsky, Stefan Kautsch Oct 2009

A Spectroscopically Confirmed Excess Of 24 Μm Sources In A Super Galaxy Group At Z=0.37: Enhanced Dusty Star Formation Relative To The Cluster And Field Environment, Kim-Vy H. Tran, Amelie Saintonge, John Moustakas, Lei Bai, Anthony H. Gonzalez, Bradford P. Holden, Dennis Zaritsky, Stefan Kautsch

Chemistry and Physics Faculty Articles

To trace how dust-obscured star formation varies with environment, we compare the fraction of 24 μm sources in a super galaxy group to the field and a rich galaxy cluster at z ~ 0.35. We draw on multi-wavelength observations that combine Hubble, Chandra, and Spitzer imaging with extensive optical spectroscopy (>1800 redshifts) to isolate galaxies in each environment and thus ensure a uniform analysis. We focus on the four galaxy groups (σ1D = 303-580 km s–1) in supergroup 1120-12 that will merge to form a galaxy cluster comparable in mass to Coma. We find …


Provenir Ontology: Towards A Framework For Escience Provenance Management, Satya S. Sahoo, Amit P. Sheth Oct 2009

Provenir Ontology: Towards A Framework For Escience Provenance Management, Satya S. Sahoo, Amit P. Sheth

Kno.e.sis Publications

Provenance metadata describes the 'lineage' or history of an entity and necessary information to verify the quality of data, validate experiment protocols, and associate trust value with scientific results. eScience projects generate data and the associated provenance metadata in a distributed environment (such as myGrid) and on a very large scale that often precludes manual analysis. Given this scenario, provenance information should be, (a) interoperable across projects, research groups, and application domains, and (b) support analysis over large datasets using reasoning to discover implicit information. In this paper, we introduce an ontology-driven framework for eScience provenance management underpinned by an …


Exchange Bias Training Effect In Magnetically Coupled Bilayers, Srinivas Polisetty Oct 2009

Exchange Bias Training Effect In Magnetically Coupled Bilayers, Srinivas Polisetty

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Interfaces in magnetically coupled bilayer heterostructures play a vital role in novel spintronics devices. Particularly, control of the interface spin structure enables the development of progressively down-scalable magnetic read-heads which are of major importance for non volatile magnetic recording media. Exchange bias and its accompanying training effect are fundamental magnetic coupling phenomena taking place at the interfaces of antiferromagnetic/ferromagnetic and hard/soft ferromagnetic bilayers. Here, in my thesis I present the experimental results of exchange bias training in the prototypical antiferromagnetic/ferromagnetic exchange bias system CoO/Co and the corresponding coupling and aging phenomena in the all ferromagnetic hard/soft bilayer CoPtCrB/CoCr. The latter …


Model Reduction For Simulation, Optimization And Control, Oleg Edward Roderick Oct 2009

Model Reduction For Simulation, Optimization And Control, Oleg Edward Roderick

Dissertations and Theses

Many tasks of simulation, optimization and control can be performed more efficiently if the intermediate complexity of the numerical model is reduced. In our work, we investigate model reduction, as applied to reaction-transport systems of atmospheric chemistry. We use a Proper Orthogonal Decomposition-based approach to extract information from a set of model observations, and to project the model equations onto a reduced order space chosen in such a way that the essential model behavior is preserved in the solution of the reduced version. We examine and improve many features of the method. In particular, we show how to measure sensitivities …


Infrasonic Ambient Noise Interferometry From Correlations Of Microbaroms, Matthew M. Haney Oct 2009

Infrasonic Ambient Noise Interferometry From Correlations Of Microbaroms, Matthew M. Haney

CGISS Publications and Presentations

We show that microbaroms, continuous infrasound fluctuations resulting from the interaction of the ocean with the atmosphere, have long-range correlation properties that make it possible to estimate the impulse response between two microphones from passive recordings. The processing is analogous to methods employed in the emerging field of ambient noise seismology, where the random noise source is the ocean coupling with the solid Earth (microseisms) instead of the atmosphere (microbaroms). We find that timedependent temperature fields and temperature inversions determine the character of infrasonic impulse responses at Fourpeaked Volcano in Alaska. Applications include imaging and monitoring the gross structure of …


Slides: Intermountain Oil And Gas Bmp Project, Kathryn Mutz Oct 2009

Slides: Intermountain Oil And Gas Bmp Project, Kathryn Mutz

Best Practices for Community and Environmental Protection (October 14)

Presenter: Kathryn Mutz, Natural Resources Law Center

19 slides


Birch Bay Village Lakes 2009 Final Report, Robin A. Matthews, Joan Vandersypen, Jessie Rosanbalm Oct 2009

Birch Bay Village Lakes 2009 Final Report, Robin A. Matthews, Joan Vandersypen, Jessie Rosanbalm

Birch Bay/Village Lakes

The Institute for Watershed Studies was contracted by the Birch Bay Village Lakes Committee to continue water testing at two sites in Kwann Lake and two sites in Thunderbird Lake (Figure 1, page 4). The sampling effort was initiated in August 2007 and the results were summarized in the Birch Bay Village Lakes 2008 Final Report. The 2009 final report summarizes all results collected from August 2007 through August 2009.


Agenda: Best Practices For Community And Environmental Protection, University Of Colorado Boulder. Natural Resources Law Center. Intermountain Oil And Gas Bmp Project, Colorado. Oil And Gas Conservation Commission Oct 2009

Agenda: Best Practices For Community And Environmental Protection, University Of Colorado Boulder. Natural Resources Law Center. Intermountain Oil And Gas Bmp Project, Colorado. Oil And Gas Conservation Commission

Best Practices for Community and Environmental Protection (October 14)

The first Intermountain BMP Project workshop, sponsored by the Natural Resources Law Center and the Colorado Oil and Gas Conservation Commission, was held in Rifle, Colorado on October 14, 2009 at the Garfield County Fairground for over 170 participants.

Speakers from Federal, state and local governments, the community, industry and environmental consultants, and conservation groups focused presentations and discussion on a greater understanding of what Best Management Practices (BMPs) are appropriate to the western slope of Colorado and how they are integrated into developments.


Slides: Best Management Practices: Planning, Leasing, Permitting, Jamie Connell Oct 2009

Slides: Best Management Practices: Planning, Leasing, Permitting, Jamie Connell

Best Practices for Community and Environmental Protection (October 14)

Presenter: Jamie Connell, Northwest Colorado District Manager, U.S. Bureau of Land Management (BLM) Colorado

23 slides


Slides: Disappearing Roads--An Efd Project: An Exploration Into Low Impact And Efficient Gas Field Drilling, Charles Dolan Oct 2009

Slides: Disappearing Roads--An Efd Project: An Exploration Into Low Impact And Efficient Gas Field Drilling, Charles Dolan

Best Practices for Community and Environmental Protection (October 14)

Presenter: Rich Haut, Houston Advanced Research Center (HARC), for Dr. Charles Dolan, University of Wyoming, Environmentally Friendly Drilling Program

25 slides


Slides: Energy By Design: Possible Bmp For Mitigation Planning, Dave Gann Oct 2009

Slides: Energy By Design: Possible Bmp For Mitigation Planning, Dave Gann

Best Practices for Community and Environmental Protection (October 14)

Presenter: Dave Gann, The Nature Conservancy

15 slides


Slides: Recommended Best Management Practices For Plants Of Concern: Practices Developed To Reduce The Impacts Of Oil And Gas Development Activities To Plants Of Concern, Brian Kurzel, Colorado Rare Plant Conservation Initiative Oct 2009

Slides: Recommended Best Management Practices For Plants Of Concern: Practices Developed To Reduce The Impacts Of Oil And Gas Development Activities To Plants Of Concern, Brian Kurzel, Colorado Rare Plant Conservation Initiative

Best Practices for Community and Environmental Protection (October 14)

Presenter: Brian Kurzel, Colorado Natural Areas Program (CNAP)

27 slides


Slides: Environmentally Friendly Drilling Systems Program (Efd), Rich Haut Oct 2009

Slides: Environmentally Friendly Drilling Systems Program (Efd), Rich Haut

Best Practices for Community and Environmental Protection (October 14)

Presenter: Rich Haut, Houston Advanced Research Center

23 slides


Slides: Innovative Best Practices For The Western Slope: Stormwater Management Solutions And Philosophy For The Oil And Gas Industry, Kyle N. Schildt Oct 2009

Slides: Innovative Best Practices For The Western Slope: Stormwater Management Solutions And Philosophy For The Oil And Gas Industry, Kyle N. Schildt

Best Practices for Community and Environmental Protection (October 14)

Presenter: Kyle N. Schildt, P.E., LT Environmental, Inc.

12 slides


Slides: Rifle, Silt, New Castle Community Development Plan: A Collaborative Planning Approach To Natural Gas Development, Peggy Utesch Oct 2009

Slides: Rifle, Silt, New Castle Community Development Plan: A Collaborative Planning Approach To Natural Gas Development, Peggy Utesch

Best Practices for Community and Environmental Protection (October 14)

Presenter: Peggy Utesch, Movin' Forward Consulting

25 slides


Slides: Introduction To Constructive Engagement In The Oil And Gas Industry, Susan T. Wildau, Christopher W. Moore Oct 2009

Slides: Introduction To Constructive Engagement In The Oil And Gas Industry, Susan T. Wildau, Christopher W. Moore

Best Practices for Community and Environmental Protection (October 14)

Presenters: Susan T. Wildau and Christopher W. Moore, CDR Associates (Collaborative Decision Resources), Boulder, CO

22 slides


Geopolitics Of Global Change: The Melting Of The Arctic, Charles K. Ebinger Oct 2009

Geopolitics Of Global Change: The Melting Of The Arctic, Charles K. Ebinger

Brookings Scholar Lecture Series

Arctic Melt:
- Climate change, feedback loops
- More than one million square miles of ice melted in 2007
- We could have ice-free Arctic summers as early as 2013 or 2015
- New environmental and strategic challenges


Slides: The Use Of Terrestrial Cyanobacteria For The Rehabilitation Of Arid Soils: Not Just Another Good Idea, Timothy Flynn Oct 2009

Slides: The Use Of Terrestrial Cyanobacteria For The Rehabilitation Of Arid Soils: Not Just Another Good Idea, Timothy Flynn

Best Practices for Community and Environmental Protection (October 14)

Presenter: Dr. Timothy Flynn, Primordial Solutions Inc.

42 slides


Slides: Bmp Project, Kent Kuster Oct 2009

Slides: Bmp Project, Kent Kuster

Best Practices for Community and Environmental Protection (October 14)

Presenter: Kent Kuster, Consultation Coordinator, Colorado Department of Public Health and Environment (CDPHE)

17 slides


Slides: Comprehensive Drilling Plans, Dave Neslin Oct 2009

Slides: Comprehensive Drilling Plans, Dave Neslin

Best Practices for Community and Environmental Protection (October 14)

Presenter: Dave Neslin, Director, Colorado OIl and Gas Conservation Commission (COGCC)

8 slides


Zincast-1: A Photochemically Active Chelator For Zn2+, Shawn Burdette, Celina Gwizdala, Daniel Kennedy Oct 2009

Zincast-1: A Photochemically Active Chelator For Zn2+, Shawn Burdette, Celina Gwizdala, Daniel Kennedy

Shawn C. Burdette

Two strategies were applied to the synthesis of ZinCast-1, a nitrobenzhydrol-based caged complex that upon photolysis exhibits a nearly 400-fold difference in binding for Zn2+.


Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009 Oct 2009

Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009

Education and Outreach

No abstract provided.


Effect Of Surfactants On The Structure And Morphology Of Magnesium Borate Hydroxide Nanowhiskers Synthesized By Hydrothermal Route, Latha Kumari, Wz Li, Shrinivas Kulkarni, Kh Wu, Wei Chen, Chunlei Wang, Charles H. Vannoy, Roger M. Leblanc Oct 2009

Effect Of Surfactants On The Structure And Morphology Of Magnesium Borate Hydroxide Nanowhiskers Synthesized By Hydrothermal Route, Latha Kumari, Wz Li, Shrinivas Kulkarni, Kh Wu, Wei Chen, Chunlei Wang, Charles H. Vannoy, Roger M. Leblanc

Department of Physics

Magnesium borate hydroxide (MBH) nanowhiskers were synthesized using a one step hydrothermal process with different surfactants. The effect surfactants have on the structure and morphology of the MBH nanowhiskers has been investigated. The X-ray diffraction profile confirms that the as-synthesized material is of single phase, monoclinic MgBO2(OH). The variations in the size and shape of the different MBH nanowhiskers have been discussed based on the surface morphology analysis. The annealing of MBH nanowhiskers at 500 °C for 4 h has significant effect on the crystal structure and surface morphology. The UV–vis absorption spectra of the MBH nanowhiskers synthesized …


Fantom - Lessons Learned From Design, Implementation, Administration, And Use Of A Visualization System For Over 10 Years, Alexander Wiebel, Christoph Garth, Mario Hlawitschka, Thomas Wischgoll, Gerik Scheuermann Oct 2009

Fantom - Lessons Learned From Design, Implementation, Administration, And Use Of A Visualization System For Over 10 Years, Alexander Wiebel, Christoph Garth, Mario Hlawitschka, Thomas Wischgoll, Gerik Scheuermann

Computer Science and Engineering Faculty Publications

No abstract provided.