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2010

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Articles 211 - 240 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Activation Of Propargylic Alcohols By Piano-Stool Ruthenium Complexes Bearing Phosphoramidite Ligands, Stephen Andrew Costin Dec 2010

Activation Of Propargylic Alcohols By Piano-Stool Ruthenium Complexes Bearing Phosphoramidite Ligands, Stephen Andrew Costin

Dissertations

Various piano-stool ruthenium complexes bearing phosphoramidite ligands have been synthesized and characterized spectroscopically and in some cases structurally. Reaction of phosphoramidite ligands with an appropriate metal precursor gives new piano-stool ruthenium complexes [RuCl(L)(arene)(phosphoramidite)], where L = Cl, PPh3, or others. The novel complexes are tested for their ability to activate propargylic alcohols catalytically as well as stoichiometrically. Specifically, catalytic substitution of propargylic alcohols via allenylidene intermediates is envisioned. Stoichiometric reactions designed to form stable, isolable allenylidenes are sought as well. h6-p-cymene complexes of the type [RuCl2(h6-p-cymene)(phosphoramidite)] activate propargylic alcohols in the reaction with carboxylic acids to form b-oxo esters. The …

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Web-Based Ide To Create Model And Controller Components For Mvc-Based Web Applications On Cakephp, Sugiharto Widjaja Dec 2010

Web-Based Ide To Create Model And Controller Components For Mvc-Based Web Applications On Cakephp, Sugiharto Widjaja

Master's Projects

A Web-based IDE that allows users to easily manage Model and Controller components of a CakePHP web application was developed. With this IDE, users are able to manage the model and controller components without having to write very much PHP code. They are able to create new model components without having to worry about creating the database tables for the models as the IDE creates them automatically. The IDE offers a simple interface for users to edit the schema of their models. Users can add or delete data from their models without dealing with the SQL insert/delete statements. The IDE …

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Volcanic Stratigraphy And A Kinematic Analysis Of Ne-Trending Faults Of Allens Ranch 7.5' Quadrangle, Utah County, Utah, Adam Paul Mckean Dec 2010

Volcanic Stratigraphy And A Kinematic Analysis Of Ne-Trending Faults Of Allens Ranch 7.5' Quadrangle, Utah County, Utah, Adam Paul Mckean

Theses and Dissertations

The mineral resources of the Tintic Mining District are influenced by three major events in its geologic history; the Mesozoic Sevier Orogeny, Paleogene volcanism and Late Neogene Basin and Range extension. In this paper a detailed analysis of each these geologic events is presented to help us understand the structural host, mineralization and exhumation of the Tintic Mining District ore. A kinematic analysis of the faults was completed to determine the origin of NE-trending faults, Sevier Orogeny or Basin and Range extension, in the northern part of the East Tintic Mountains in Allens Ranch 7.5' quadrangle, near the eastern margin …

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Trusted Mobile Overlays, Robert Scott Robertson Dec 2010

Trusted Mobile Overlays, Robert Scott Robertson

Theses and Dissertations

Sensitive information is increasingly moving online and as data moves further from the control of its owner, there are increased opportunities for it to fall into malicious hands. The Web is comprised of three untrusted components where there is a risk of information compromise: networks, service providers, and clients. This thesis presents Trusted Mobile Overlays: a system that leverages trusted mobile devices to protect users from these untrusted components of the Web, while minimizing deployment difficulties. It presents a high-level design of the system as well as a prototype that implements the design.

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Sources Of The Radio Background Considered, Jack Singal, L. Stawarz, A. Lawrence, V. Petrosian Dec 2010

Sources Of The Radio Background Considered, Jack Singal, L. Stawarz, A. Lawrence, V. Petrosian

Physics Faculty Publications

We investigate different scenarios for the origin of the extragalactic radio background. The surface brightness of the background, as reported by the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission 2 (ARCADE 2) collaboration, is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low-surface-brightness regions of radio sources and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio …

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Preventing Computer Identity Theft, Donald R. Mcdaniel Dec 2010

Preventing Computer Identity Theft, Donald R. Mcdaniel

Regis University Student Publications (comprehensive collection)

The arrival of the information age has created new challenges to the ability of individuals to protect the security and privacy of their personal information. One such challenge is that of identity theft, which has caused a number of hardships upon its victims. Perpetrators of this fraud may use identities of others to obtain loans, steal money, and violate the law. This paper will discuss the characteristics of the offenders and victims of identity theft. A systematic approach for preventing identity theft will also be presented with the hopes of curtailing this epidemic.

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Nanoparticle Doped Photopolymer With Reduced Shrinkage For Holographic Recording, Mohesh Moothanchery, Svetlana Mintova, Izabela Naydenova, Vincent Toal Dec 2010

Nanoparticle Doped Photopolymer With Reduced Shrinkage For Holographic Recording, Mohesh Moothanchery, Svetlana Mintova, Izabela Naydenova, Vincent Toal

Conference Papers

We demonstrate holographic recording with Si-MFI zeolite doped acrylamide based photopolymerfilm. The influence of silicate nanoparticles on photopolymer shrinkage has been studied and compared withshrinkage in undoped photopolymer layers The shrinkage of the material (1.03%) is significantly lower forrecording in Si-MFI zeolite nanoparticle doped samples than for undoped layers (1.77%).

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Fast Query Processing By Distributing An Index Over Cpu Caches, Xiaoqin Ma, Gene D. Cooperman Dec 2010

Fast Query Processing By Distributing An Index Over Cpu Caches, Xiaoqin Ma, Gene D. Cooperman

Gene D. Cooperman

Data intensive applications on clusters often require requests quickly be sent to the node managing the desired data. In many applications, one must look through a sorted tree structure to determine the responsible node for accessing or storing the data. Examples include object tracking in sensor networks, packet routing over the internet, request processing in publish-subscribe middleware, and query processing in database systems. When the tree structure is larger than the CPU cache, the standard implementation potentially incurs many cache misses for each lookup; one cache miss at each successive level of the tree. As the CPURAM gap grows, this …

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Air Shower Simulation Using Geant4 And Commodity Parallel Computing, L. Anchordoqui, G. Cooperman, V. Grinberg, T. Mccauley, T. Paul, S. Reucroft, J. Swain, G. Alverson Dec 2010

Air Shower Simulation Using Geant4 And Commodity Parallel Computing, L. Anchordoqui, G. Cooperman, V. Grinberg, T. Mccauley, T. Paul, S. Reucroft, J. Swain, G. Alverson

Gene D. Cooperman

We present an evaluation of a simulated cosmic ray shower, based on GEANT4 and TOP-C, which tracks all the particles in the shower. TOP-C (Task Oriented Parallel C) provides a framework for parallel algorithm development which makes tractable the problem of following each particle. This method is compared with a simulation program which employs the Hillas thinning algorithm.

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End Of Year Report : Fy 2005, Gene Cooperman Dec 2010

End Of Year Report : Fy 2005, Gene Cooperman

Gene D. Cooperman

No abstract provided.

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Geant4 Developments And Applications, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce Dubois, M. Asai, G. Barrand, R. Capra, S. Chauvie, R. Chytracek, G. A. P. Cirrone, Gene D. Cooperman, G. Cosmo, G. Cuttone, G. G. Daquino, M. Donszelmann, M. Dressel, G. Folger, F. Foppiano, J. Generowicz, V. Grichine, S. Guatelli, P. Gumplinger, A. Heikkinen, I. Hrivnacova, A. Howard, S. Incerti, V. Ivanchenko, T. Johnson, F. Jones, T. Koi, R. Kokoulin, M. Kossov, H. Kurashige, V. Lara, S. Larsson, F. Lei, O. Link, F. Longo, M. Maire, A. Mantero, B. Mascialino, I. Mclaren, P. Mendez Lorenzo, K. Minamimoto, K. Murakami, P. Nieminen, L. Pandola, S. Parlati, L. Peralta, J. Perl, A. Pfeiffer, M. G. Pia, A. Ribon, P. Rodrigues, G. Russo, S. Sadilov, G. Santin, T. Sasaki, D. Smith, N. Starkov, S. Tanaka, E. Tcherniaev, B. Tomé, A. Trindade, P. Truscott, L. Urban, M. Verderi, A. Walkden, J. P. Wellisch, D. C. Williams, D. Wright, H. Yoshida Dec 2010

Geant4 Developments And Applications, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce Dubois, M. Asai, G. Barrand, R. Capra, S. Chauvie, R. Chytracek, G. A. P. Cirrone, Gene D. Cooperman, G. Cosmo, G. Cuttone, G. G. Daquino, M. Donszelmann, M. Dressel, G. Folger, F. Foppiano, J. Generowicz, V. Grichine, S. Guatelli, P. Gumplinger, A. Heikkinen, I. Hrivnacova, A. Howard, S. Incerti, V. Ivanchenko, T. Johnson, F. Jones, T. Koi, R. Kokoulin, M. Kossov, H. Kurashige, V. Lara, S. Larsson, F. Lei, O. Link, F. Longo, M. Maire, A. Mantero, B. Mascialino, I. Mclaren, P. Mendez Lorenzo, K. Minamimoto, K. Murakami, P. Nieminen, L. Pandola, S. Parlati, L. Peralta, J. Perl, A. Pfeiffer, M. G. Pia, A. Ribon, P. Rodrigues, G. Russo, S. Sadilov, G. Santin, T. Sasaki, D. Smith, N. Starkov, S. Tanaka, E. Tcherniaev, B. Tomé, A. Trindade, P. Truscott, L. Urban, M. Verderi, A. Walkden, J. P. Wellisch, D. C. Williams, D. Wright, H. Yoshida

Gene D. Cooperman

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Its functionality and modeling capabilities continue to be extended, while its performance is enhanced. An overview of recent developments in diverse areas of the toolkit is presented. These include performance optimization for complex setups; improvements for the propagation in fields; new options for event biasing; and additions and improvements in geometry, physics processes and interactive …

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Adaptive Checkpointing For Master-Worker Style Parallelism (Extended Abstract), Gene D. Cooperman, Jason Ansel, Xiaoqin Ma Dec 2010

Adaptive Checkpointing For Master-Worker Style Parallelism (Extended Abstract), Gene D. Cooperman, Jason Ansel, Xiaoqin Ma

Gene D. Cooperman

No abstract provided.

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Dmtcp: Transparent Checkpointing For Cluster Computations And The Desktop, Jason Ansel, Kapil Arya, Gene D. Cooperman Dec 2010

Dmtcp: Transparent Checkpointing For Cluster Computations And The Desktop, Jason Ansel, Kapil Arya, Gene D. Cooperman

Gene D. Cooperman

DMTCP (Distributed MultiThreaded CheckPointing) is a transparent user-level checkpointing package for distributed applications. Checkpointing and restart is demonstrated for a wide range of over 20 well known applications, including MATLAB, Python, TightVNC, MPICH2, OpenMPI, and runCMS. RunCMS runs as a 680 MB image in memory that includes 540 dynamic libraries, and is used for the CMS experiment of the Large Hadron Collider at CERN. DMTCP transparently checkpoints general cluster computations consisting of many nodes, processes, and threads; as well as typical desktop applications. On 128 distributed cores (32 nodes), checkpoint and restart times are typically 2 seconds, with negligible run-time …

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End Of Year Report : Fy 2004, Gene Cooperman Dec 2010

End Of Year Report : Fy 2004, Gene Cooperman

Gene D. Cooperman

No abstract provided.

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Classification Of Generalized Hadamard Matrices H(6,3) And Quaternary Hermitian Self-Dual Codes Of Length 18, Masaaki Harada, Clement Lam, Akihiro Munemasa, Vladimir Tonchev Dec 2010

Classification Of Generalized Hadamard Matrices H(6,3) And Quaternary Hermitian Self-Dual Codes Of Length 18, Masaaki Harada, Clement Lam, Akihiro Munemasa, Vladimir Tonchev

Department of Mathematical Sciences Publications

All generalized Hadamard matrices of order 18 over a group of order 3, H(6,3),are enumerated in two different ways: once, as class regular symmetric (6,3)-nets,or symmetric transversal designs on 54 points and 54 blocks with a group of order 3 acting semi-regularly on points and blocks, and secondly,as collections of fullweight vectors in quaternary Hermitian self-dual codes of length 18. The second enumeration is based on the classification of Hermitian self-dual [18,9] codes over GF(4), completed in this paper. It is shown that up to monomial equivalence, there are 85 generalized Hadamard matrices H(6,3), and 245 inequivalent Hermitian self-dual codes …

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Late 20th Century Hydrologic Change In Western North America: Regional Impacts And The Role Of Climate, Shaleen Jain Dec 2010

Late 20th Century Hydrologic Change In Western North America: Regional Impacts And The Role Of Climate, Shaleen Jain

University of Maine Office of Research Administration: Grant Reports

Hydroclimatic variations and change directly impact the freshwater supplies in western North America. Streamflow in this region has shown increased variability of annual flow volumes and increasing synchroneity in the largest basins in the west towards the end of last century. As land-use change seems to play a lesser role, the PI will study the sensitivity of the western North American winter precipitation and related streamflow to El Nino-Southern Oscillation variations. The PI will use observations and multi-model ensemble integrations to study the decadal variations. The broader impact of this project will be an increase of the scientific knowledge required …

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Discrete Breathers At The Interface Between A Diatomic And A Monoatomic Granular Chain, C. Hoogeboom, G. Theocharis, Panos Kevrekidis Dec 2010

Discrete Breathers At The Interface Between A Diatomic And A Monoatomic Granular Chain, C. Hoogeboom, G. Theocharis, Panos Kevrekidis

Panos Kevrekidis

In the present work, we develop a systematic examination of the existence, stability, and dynamical properties of a discrete breather at the interface between a diatomic and a monoatomic granular chain. We remarkably find that such an “interface breather” is more robust than its bulk diatomic counterpart throughout the gap of the linear spectrum. The latter linear spectral gap needs to exist for the breather state to arise and the relevant spectral conditions are discussed. We illustrate the minimal excitation conditions under which such an interface breather can be “nucleated” and analyze its apparently weak interaction with regular highly nonlinear …

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Retired A Stars And Their Companions. Vi. A Pair Of Interacting Exoplanet Pairs Around The Subgiants 24 Sextanis And Hd 200964*, John Asher Johnson, Matthew J. Payne, Andrew W. Howard, Kelsey I. Clubb, Eric B. Ford, Brendan P. Bowler, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, John M. Brewer, Christian Schwab, Sabine Reffert, Thomas B. Lowe Dec 2010

Retired A Stars And Their Companions. Vi. A Pair Of Interacting Exoplanet Pairs Around The Subgiants 24 Sextanis And Hd 200964*, John Asher Johnson, Matthew J. Payne, Andrew W. Howard, Kelsey I. Clubb, Eric B. Ford, Brendan P. Bowler, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, John M. Brewer, Christian Schwab, Sabine Reffert, Thomas B. Lowe

Information Systems and Engineering Management Research Publications

We report radial velocity (RV) measurements of the G-type subgiants 24 Sextanis (= HD 90043) and HD 200964. Both are massive, evolved stars that exhibit periodic variations due to the presence of a pair of Jovian planets. Photometric monitoring with the T12 0.80 m APT at Fairborn Observatory demonstrates both stars to be constant in brightness to ⩽0.002 mag, thus strengthening the planetary interpretation of the RV variations. Based on our dynamical analysis of the RV time series, 24 Sex b, c have orbital periods of 452.8 days and 883.0 days, corresponding to semimajor axes 1.333 AU and 2.08 AU, …

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The Hanle Effect As A Diagnostic Of Magnetic Fields In Stellar Envelopes. V. Thin Lines From Keplerian Disks., Richard Ignace Dec 2010

The Hanle Effect As A Diagnostic Of Magnetic Fields In Stellar Envelopes. V. Thin Lines From Keplerian Disks., Richard Ignace

ETSU Faculty Works

This paper focuses on the polarized profiles of resonance scattering lines that form in magnetized disks. Optically thin lines from Keplerian planar disks are considered. Model line profiles are calculated for simple field topologies of axial fields (i.e., vertical to the disk plane) and toroidal fields (i.e., purely azimuthal). A scheme for discerning field strengths and geometries in disks is developed based on Stokes Q − U diagrams for the run of polarization across line profiles that are Doppler-broadened by the disk rotation. A discussion of the Hanle effect for magnetized disks in which the magnetorotational instability (MRI) is operating …

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First Order Analysis Of Nitrate Loading In The Upper Elbe River Basin, Czech Republic, Daniel J. Ritter Dec 2010

First Order Analysis Of Nitrate Loading In The Upper Elbe River Basin, Czech Republic, Daniel J. Ritter

Theses and Dissertations

Nitrate contamination of water is a worldwide issue. Nitrate is especially dangerous for young children, and may result in potentially fatal blue baby syndrome when concentration in drinking water is > 10 mg/L N-NO3. Nitrate in surface water may also lead to eutrophication. Sources of NO3- contamination include nitrate fertilizers, wastewater treatment plants, individual domestic septic systems, runoff from animal feedlots, and natural soil nitrogen. Nitrate contamination in the Elbe River drainage, covering 148,270 km2 in Germany and the Czech Republic, has been a long-term issue. This study examines the upper one-third of the basin, located almost entirely in the Czech …

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Tunable Optical Delay In Doppler-Broadened Cesium Vapor, Monte D. Anderson Dec 2010

Tunable Optical Delay In Doppler-Broadened Cesium Vapor, Monte D. Anderson

Theses and Dissertations

Variable-delay tunable optical delay line or optical buffers are critical for the development of all-optical networks components as well as interferometry and analytic instruments. Recent research on slow light may hold the key for the development of the first practical tunable optical delay device. In this research the linear dispersion delay effects in an alkali vapor. The hyperfine relaxation observations present insight into the complex bleach wave dynamics during a high-intensity pulsed pump in DPAL systems.

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Asynchronous Database Drivers, Michael Adam Heath Dec 2010

Asynchronous Database Drivers, Michael Adam Heath

Theses and Dissertations

Existing database drivers use blocking socket I/O to exchange data with relational database management systems (RDBMS). To concurrently send multiple requests to a RDBMS with blocking database drivers, a separate thread must be used for each request. This approach has been used successfully for many years. However, we propose that using non-blocking socket I/O is faster and scales better under load. In this paper we introduce the Asynchronous Database Connectivity in Java (ADBCJ) framework. ADBCJ provides a common API for asynchronous RDBMS interaction. Various implementations of the ADBCJ API are used to show how utilizing non-blocking socket I/O is faster …

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Double Compact Objects As Low-Frequency Gravitational Wave Sources, Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik Dec 2010

Double Compact Objects As Low-Frequency Gravitational Wave Sources, Krzysztof Belczynski, Matthew Benacquista, Tomasz Bulik

Physics and Astronomy Faculty Publications and Presentations

We study the Galactic field population of double compact objects (DCOs; NS-NS, BH-NS, BH-BH binaries) to investigate the number (if any) of these systems that can potentially be detected with the Laser Interferometer Space Antenna (LISA) at low gravitational wave frequencies. We calculate the Galactic numbers and physical properties of these binaries and show their relative contributions from the disk, bulge, and halo. Although the Galaxy hosts ∼10 5 DCO binaries emitting low-frequency gravitational waves, only a handful of these objects in the disk will be detectable with LISA, but none from the halo or bulge. This is because the …

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Graphs Of Bounded Degree And The P-Harmonic Boundary, Michael J. Puls Dec 2010

Graphs Of Bounded Degree And The P-Harmonic Boundary, Michael J. Puls

Publications and Research

Let p be a real number greater than one and let G be a connected graph of bounded degree. We introduce the p-harmonic boundary of G and use it to characterize the graphs G for which the constant functions are the only p-harmonic functions on G. We show that any continuous function on the p-harmonic boundary of G can be extended to a function that is p-harmonic on G. We also give some properties of this boundary that are preserved under rough-isometries. Now let Gamma be a finitely generated group. As an application of our results, we characterize the vanishing …

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Test-Driven Web Application Development: Increasing The Quality Of Web Development By Providing Framework With An Emphasis On Test-Driven Design And Development Methodologies, Jason Hall Dec 2010

Test-Driven Web Application Development: Increasing The Quality Of Web Development By Providing Framework With An Emphasis On Test-Driven Design And Development Methodologies, Jason Hall

Regis University Student Publications (comprehensive collection)

Web applications , especially those based on interpreted programming languages , are quickly becoming more utilized and more commonplace than traditional client applications. Despite this growth, no open solution has yet fulfilled the need of a risk-reducing development framework that supports test-driven methodologies and tools designed to coordinate the resources responsible for the most effective development of web applications based on interpreted programming languages. This research paper presents a test-driven development framework consisting of openly available components that can be used by development teams writing web applications based on interpreted programming languages based on the methodologies and tools used by …

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Factors Influencing Macroinvertebrate Diversity And Community Composition In Riverine Freshwater Rock Pools, Chtaura Jackson Dec 2010

Factors Influencing Macroinvertebrate Diversity And Community Composition In Riverine Freshwater Rock Pools, Chtaura Jackson

Theses and Dissertations

I examined a system of 378-riverine rock pools situated along the James River in Richmond, Virginia, to uncover the factors influencing their macroinvertebrate diversity and community composition. I characterized (total = 60) the physical characteristics, water quality, hydrology, and community assemblages in July 2009 for a subset of pools. I examined whether selected environmental factors (pH, nearest neighbor distance, depth, surface area and inundation height) were related to macroinvertebrate diversity and community composition. Species richness and total abundance of all taxa increased with pool pH and surface area. Ordination indicates that nearest neighbor distance (NND) and pH varied significantly among …

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Equation Of State Of A Dense And Magnetized Fermion System, Efrain J. Ferrer, Vivian De La Incera, Jason P. Keith, Israel Portillo, Paul L. Springsteen Dec 2010

Equation Of State Of A Dense And Magnetized Fermion System, Efrain J. Ferrer, Vivian De La Incera, Jason P. Keith, Israel Portillo, Paul L. Springsteen

Physics and Astronomy Faculty Publications and Presentations

The equation of state of a system of fermions in a uniform magnetic field is obtained in terms of the thermodynamic quantities of the theory by using functional methods. It is shown that the breaking of the O(3) rotational symmetry by the magnetic field results in a pressure anisotropy, which leads to the distinction between longitudinal- and transverse-to-the-field pressures. A criterion to find the threshold field at which the asymmetric regime becomes significant is discussed. This threshold magnetic field is shown to be the same as the one required for the pure field contribution to the energy and pressures to …

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Gene Network Inference And Expression Prediction Using Recurrent Neural Networks And Evolutionary Algorithms, Heather Y. Chan Dec 2010

Gene Network Inference And Expression Prediction Using Recurrent Neural Networks And Evolutionary Algorithms, Heather Y. Chan

Theses and Dissertations

We demonstrate the success of recurrent neural networks in gene network inference and expression prediction using a hybrid of particle swarm optimization and differential evolution to overcome the classic obstacle of local minima in training recurrent neural networks. We also provide an improved validation framework for the evaluation of genetic network modeling systems that will result in better generalization and long-term prediction capability. Success in the modeling of gene regulation and prediction of gene expression will lead to more rapid discovery and development of therapeutic medicine, earlier diagnosis and treatment of adverse conditions, and vast advancements in life science research.

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Contemporary Pedogenesis Of Severely Degraded Tropical Acid Sulfate Soils After Introduction Of Regular Tidal Inundation, Scott G. Johnston, Annabelle F. Keene, Richard T. Bush, Edward D. Burton, Leigh A. Sullivan, C Douglas Smith, Angus E. Mcelnea, Michelle A. Martens, Steven T. Wilbraham Dec 2010

Contemporary Pedogenesis Of Severely Degraded Tropical Acid Sulfate Soils After Introduction Of Regular Tidal Inundation, Scott G. Johnston, Annabelle F. Keene, Richard T. Bush, Edward D. Burton, Leigh A. Sullivan, C Douglas Smith, Angus E. Mcelnea, Michelle A. Martens, Steven T. Wilbraham

Professor Edward D Burton

Marine tidal inundation was partially restored to a severely degraded tropical acid sulfate soil landscape after having been excluded for over 30 years. The effects on soil acidity and iron-sulfide mineral reformation were investigated by comparing the geochemistry of soils before and after five years of regular tidal inundation. The soil pH increased by 2–3 units and titratable actual acidity (TAA) decreased by 40–50 μmol H+ g− 1 within former sulfuric horizons. Relict acidity remained at depth (> 1 m) in the underlying sulfidic horizons. δ34S data indicate that tidal inundation caused exchange of marine solutes within former sulfuric horizons, …

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The Hanle Effect As A Diagnostic Of Magnetic Fields In Stellar Envelopes. V. Thin Lines From Keplerian Disks., R. Ignace Dec 2010

The Hanle Effect As A Diagnostic Of Magnetic Fields In Stellar Envelopes. V. Thin Lines From Keplerian Disks., R. Ignace

Richard Ignace

This paper focuses on the polarized profiles of resonance scattering lines that form in magnetized disks. Optically thin lines from Keplerian planar disks are considered. Model line profiles are calculated for simple field topologies of axial fields (i.e., vertical to the disk plane) and toroidal fields (i.e., purely azimuthal). A scheme for discerning field strengths and geometries in disks is developed based on Stokes Q − U diagrams for the run of polarization across line profiles that are Doppler-broadened by the disk rotation. A discussion of the Hanle effect for magnetized disks in which the magnetorotational instability (MRI) is operating …

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