Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1531 - 1560 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Collaborative Research: Centers For Ocean Science Education Excellence- Ocean In The Earth-Sun System, Lee Karp-Boss, Emmanuel S. Boss Sep 2010

Collaborative Research: Centers For Ocean Science Education Excellence- Ocean In The Earth-Sun System, Lee Karp-Boss, Emmanuel S. Boss

University of Maine Office of Research Administration: Grant Reports

This award establishes a new Center for Ocean Science Education Excellence (COSEE) via awards to the Bigelow Laboratory for Ocean Sciences (0528706), the University of Maine (0528702), and the University of New Hampshire (0528686). The main goals of this thematic Center are to broaden understanding of the oceans in the context of the earth and solar systems and to help the COSEE network reach rural and inland audiences. The PIs will pioneer a system of interfaces, tools, and resources to reach underserved and underrepresented groups, and to bring ocean sciences to inland audiences by presenting it in the context of …

Go to article

Induced Absorption Dynamics In Quantum Dot Based Waveguide Electroabsorbers, T. Piwonski, Jaroslaw Pulka, Guillaume Huyet, Et. Al. Sep 2010

Induced Absorption Dynamics In Quantum Dot Based Waveguide Electroabsorbers, T. Piwonski, Jaroslaw Pulka, Guillaume Huyet, Et. Al.

Physical Sciences Publications

Two-color pump-probe measurements are used to study the carrier dynamics of InAs/GaAs quantum dots in a waveguide structure under reverse bias conditions. For the case of initially populating the ground state (GS), we find relaxation dynamics that include both absorptive and bleaching components in the excited state (ES) wavelength range. We reproduce the main features of this induced absorption dynamics using a simple model with an additional term for induced absorption at the ES due to carriers injected at the GS. The induced absorption dynamics includes multiple recovery timescales which can be attributed to phonon-assisted processes of GS/ES interaction.

Go to article

Results Of The Gulfwatch 2010 Samples : Memorandum, Matthew A. Wood Sep 2010

Results Of The Gulfwatch 2010 Samples : Memorandum, Matthew A. Wood

PREP Reports & Publications

The purpose of this memorandum is to document the sample collection activities for Gulfwatch 2010. .

Go to article

Wind Energy Collaboration Is Great Idea, The Newport Daily News Sep 2010

Wind Energy Collaboration Is Great Idea, The Newport Daily News

East Bay Energy Consortium Documents

No abstract provided.

Go to article

Teaching Calculus With Wolfram Alpha, Andrew Lang Sep 2010

Teaching Calculus With Wolfram Alpha, Andrew Lang

College of Science and Engineering Faculty Research and Scholarship

This article describes the benefits and drawbacks of using Wolfram|Alpha as the platform for teaching calculus concepts in the lab setting. It is a result of our experiences designing and creating an entirely new set of labs using Wolfram|Alpha. We present the reasoning behind our transition from using a standard computer algebra system (CAS) to Wolfram|Alpha in our differential and integral calculus labs, together with the positive results from our experience. We also discuss the current limitations of Wolfram|Alpha, including a discussion on why we still use a CAS for our multivariate calculus labs.

Go to article

Discovery Of Cyclic Spot Activity On The G8 Giant Hd 208472, Orkun Özdarcan, Serdar Evren, Klaus G. Strassmeier, Thomas Granzer, Gregory W. Henry Sep 2010

Discovery Of Cyclic Spot Activity On The G8 Giant Hd 208472, Orkun Özdarcan, Serdar Evren, Klaus G. Strassmeier, Thomas Granzer, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We present and analyze 17 consecutive years of UBVRI time-series photometry of the spotted giant component of the RS CVn binary HD 208472. Our aim is to determine the morphology and the evolution of its starspots by using periodsearch techniques and two-spot light-curve modelling. Spots on HD208472 always occur on hemispheres facing the observer during orbital quadrature and flip their location to the opposite hemisphere every approximately six years. The times when the spots change their preferential hemisphere correspond to times when the light curve amplitudes are the smallest and when abrupt changes of the photometric periods are observed. During …

Go to article

Seawater Inundation Of Fe-Rich Coastal Lowlands – Hydrogeochemical Coupling And Hysteresis At The Tidal Fringe, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan Sep 2010

Seawater Inundation Of Fe-Rich Coastal Lowlands – Hydrogeochemical Coupling And Hysteresis At The Tidal Fringe, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan

Associate Professor Edward D Burton

Over 17 million ha of coastal lowlands contain acid sulfate soils (CASS). These soils are rich in meta-stable, redoxsensitive Fe (III)-minerals. Large areas of CASS are at risk of increased saline tidal inundation due to sea-level rise. Fieldbased CASS remediation trials reveal that tidal seawater inundation initiates radical changes in sediment hydrogeochemistry, stimulating Fe and SO4 reducing conditions, generating alkalinity and greatly decreasing the acidity hazard. However, these changes also have profound consequences for the fate, mobilisation, redistribution and transformation of Fe minerals and co-associated trace elements. Here, we examine the consequences for iron and arsenic by investigating the hydrology, …

Go to article

Climate Change Impacts On Acid Sulfate Soil Landscapes, Richard Bush, Leigh Sullivan, Edward Burton, Scott Johnston, Annabelle Keene, Vanessa Wong, L Mosley Sep 2010

Climate Change Impacts On Acid Sulfate Soil Landscapes, Richard Bush, Leigh Sullivan, Edward Burton, Scott Johnston, Annabelle Keene, Vanessa Wong, L Mosley

Associate Professor Edward D Burton

The anticipated impacts of climate change are warmer conditions, an increasing proportion of rainfall to occur from heavy falls, increasing occurrence of drought in many regions, increasing frequency of intense tropical cyclones, rising sea levels and frequency of extreme high seas (e.g. storm surges). All of these predicted impacts have direct relevance to coastal acid sulfate soils landscapes, through either exacerbating sulfide oxidation by drought, re-instating reductive geochemical processes or changing the export and mobilisation of contaminants. The interaction of specific land management factors such as man-made drainage will also have a significant role in how the predicted impacts of …

Go to article

The Nature Of Starbursts: I. The Star Formation Histories In Eighteen Nearby Starburst Dwarf Galaxies, Kristen B.W. Mcquinn, Evan D. Skillman, John M. Cannon, Julianne Dalcanton, Andrew Dolphin, Sebastian Hidalgo-Rodríguez, Jon Holtzman, David Stark, Daniel Weisz, Benjamin Williams Sep 2010

The Nature Of Starbursts: I. The Star Formation Histories In Eighteen Nearby Starburst Dwarf Galaxies, Kristen B.W. Mcquinn, Evan D. Skillman, John M. Cannon, Julianne Dalcanton, Andrew Dolphin, Sebastian Hidalgo-Rodríguez, Jon Holtzman, David Stark, Daniel Weisz, Benjamin Williams

John Cannon

No abstract provided.

Go to article

The Energetics Of Molecular Gas In Ngc 891 From H2 And Far-Infrared Spectroscopy, G. J. Stacey, Vassilis Charmandaris, F. Boulanger, Yanling Wu, F. Combes, S. J. U. Higdon, J. D. T. Smith, T. Nikola Sep 2010

The Energetics Of Molecular Gas In Ngc 891 From H2 And Far-Infrared Spectroscopy, G. J. Stacey, Vassilis Charmandaris, F. Boulanger, Yanling Wu, F. Combes, S. J. U. Higdon, J. D. T. Smith, T. Nikola

Department of Physics and Astronomy Faculty Publications

We have studied the molecular hydrogen energetics of the edge-on spiral galaxy NGC?891, using a 34 position map in the lowest three pure rotational H2 lines observed with the Spitzer Infrared Spectrograph. The S(0), S(1), and S(2) lines are bright with an extinction-corrected total luminosity of ~2.8 × 107 L ?, or 0.09% of the total-infrared luminosity of NGC?891. The H2 line ratios are nearly constant along the plane of the galaxy?we do not observe the previously reported strong drop-off in the S(1)/S(0) line intensity ratio in the outer regions of the galaxy, so …

Go to article

A Correlation Attack Against User Mobility Privacy In A Large-Scale Wlan Network, Keren Tan, Guanhua Yan, Jihwang Yeo, David Kotz Sep 2010

A Correlation Attack Against User Mobility Privacy In A Large-Scale Wlan Network, Keren Tan, Guanhua Yan, Jihwang Yeo, David Kotz

Dartmouth Scholarship

User association logs collected from real-world wireless LANs have facilitated wireless network research greatly. To protect user privacy, the common practice in sanitizing these data before releasing them to the public is to anonymize users' sensitive information such as the MAC addresses of their devices and their exact association locations. In this work,we demonstrate that these sanitization measures are insufficient in protecting user privacy from a novel type of correlation attack that is based on CRF (Conditional Random Field). In such a correlation attack, the adversary observes the victim's AP (Access Point) association activities for a short period of time …

Go to article

Storage Virtualization Promises Agility In The Data Center, Peter Egli Sep 2010

Storage Virtualization Promises Agility In The Data Center, Peter Egli

Regis University Student Publications (comprehensive collection)

Data storage and protection has moved to the forefront of Information Technology solutions because the business value of data has gained in rank and importance in the world of internet commerce. Modern business models are built around instant and continuous data availability and they would not be able to function without this quality. This level of data availability requires data storage technologies to be of increased flexibility and higher performance. However the more sophisticated technologies pose a greater challenge to the architects of data storage solutions who are required to evaluate products of much higher complexity and administrators who need …

Go to article

Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner Sep 2010

Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner

Faculty Publications

Although the broadly observed increase in nutrient loading rates to coastal waters in the last 100 years may increase aboveground biomass, it also tends to increase soil metabolism and lower root and rhizome biomass—responses that can compromise soil strength. Fourteen different multiyear field combinations of nutrient amendments to salt marshes were made to determine the relationship between soil strength and various nitrogen, phosphorus, and nitrogen+phosphorus loadings. There was a proportional decline in soil strength that reached 35% in the 60- to 100-cm soil layer at the highest loadings and did not level off. These loading rates are equivalent to those …

Go to article

Diagnosing And Responding To Violations In The Positivity Assumption, Maya L. Petersen, Kristin Porter, Susan Gruber, Yue Wang, Mark J. Van Der Laan Sep 2010

Diagnosing And Responding To Violations In The Positivity Assumption, Maya L. Petersen, Kristin Porter, Susan Gruber, Yue Wang, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

The assumption of positivity or experimental treatment assignment requires that observed treatment levels vary within confounder strata. This article discusses the positivity assumption in the context of assessing model and parameter-specific identifiability of causal effects. Positivity violations occur when certain subgroups in a sample rarely or never receive some treatments of interest. The resulting sparsity in the data may increase bias with or without an increase in variance and can threaten valid inference. The parametric bootstrap is presented as a tool to assess the severity of such threats and its utility as a diagnostic is explored using simulated data. Several …

Go to article

Deformation Waves In Microstructured Materials: Theory And Numerics, Juri Engelbrecht, Arkadi Berezovski, Mihhail Berezovski Sep 2010

Deformation Waves In Microstructured Materials: Theory And Numerics, Juri Engelbrecht, Arkadi Berezovski, Mihhail Berezovski

Publications

A linear model of the microstructured continuum based on Mindlin theory is adopted which can be represented in the framework of the internal variable theory. Fully coupled systems of equations for macro-motion and microstructure evolution are represented in the form of conservation laws. A modification of wave propagation algorithm is used for numerical calculations. Results of direct numerical simulations of wave propagation in periodic medium are compared with similar results for the continuous media with the modelled microstructure. It is shown that the proper choice of material constants should be made to match the results obtained by both approaches

Go to article

Implementing Functionality To Identify And Fix Time Gaps, And Generate Custom Reports And Graphs Will Improve The Analysis, Modification And Reporting Off Tidal Data In Ireland, Shane Galvin Sep 2010

Implementing Functionality To Identify And Fix Time Gaps, And Generate Custom Reports And Graphs Will Improve The Analysis, Modification And Reporting Off Tidal Data In Ireland, Shane Galvin

Regis University Student Publications (comprehensive collection)

The Irish National Tide Gauge Network (ITGN) is ongoing development involving the Marine Institute (MI) and a number of public sector organisations to develop a permanent tidal monitoring infrastructure. As part of this ongoing work the MI wish to be able to analyse the existing ITGN dataset for time gaps, and make changes to the dataset if needed, they would also like to be able to view custom reports and graphs based on the ITGN dataset. This thesis presents a webbased and windows application to meet the aforementioned needs of the Marine Institute and ITGN.

Go to article

Impacts Of Sea Level Rise On The Biogeochemistry Of A Coastal Floodplain In Eastern Australia, Vanessa Wong, Phillip Hirst, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton, P Slavich Sep 2010

Impacts Of Sea Level Rise On The Biogeochemistry Of A Coastal Floodplain In Eastern Australia, Vanessa Wong, Phillip Hirst, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton, P Slavich

Associate Professor Edward D Burton

No abstract provided.

Go to article

Evaluation Of Existing Methods For Assessing Retained Acidity In Acid Sulfate Soil Materials, C Vithana, Leigh Sullivan, Richard Bush, Edward Burton, Scott Johnston Sep 2010

Evaluation Of Existing Methods For Assessing Retained Acidity In Acid Sulfate Soil Materials, C Vithana, Leigh Sullivan, Richard Bush, Edward Burton, Scott Johnston

Associate Professor Edward D Burton

No abstract provided.

Go to article

Mobilisation Of Arsenic Following Sea-Water Inundation Of Acid Sulfate Soils, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan Sep 2010

Mobilisation Of Arsenic Following Sea-Water Inundation Of Acid Sulfate Soils, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan

Associate Professor Edward D Burton

No abstract provided.

Go to article

Reductive Dissolution Of Natural Jarosite In A Tidally Inundated Acid Sulfate Soil: Geochemical Implications, Annabelle Keene, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton Sep 2010

Reductive Dissolution Of Natural Jarosite In A Tidally Inundated Acid Sulfate Soil: Geochemical Implications, Annabelle Keene, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton

Associate Professor Edward D Burton

No abstract provided.

Go to article

Effectiveness Of Lime Particle Size In The Neutralisation Of Sulfidic Acid Sulfate Soil Materials, Kim Watling, Angus Mcelnea, Colin Ahern, Edward Burton, Scott Johnston, Annabelle Keene, Richard Bush, Leigh Sullivan Sep 2010

Effectiveness Of Lime Particle Size In The Neutralisation Of Sulfidic Acid Sulfate Soil Materials, Kim Watling, Angus Mcelnea, Colin Ahern, Edward Burton, Scott Johnston, Annabelle Keene, Richard Bush, Leigh Sullivan

Associate Professor Edward D Burton

No abstract provided.

Go to article

Sulfidisation Processes In A Reactive Fe-Enriched Acid Sulfate Soil, Northeastern Australia, Annabelle Keene, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton Sep 2010

Sulfidisation Processes In A Reactive Fe-Enriched Acid Sulfate Soil, Northeastern Australia, Annabelle Keene, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton

Associate Professor Edward D Burton

No abstract provided.

Go to article

Remediating Coastal Acid Sulfate Soils By Tidal Inundation: Geochemical Hysteresis Of Iron, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan Sep 2010

Remediating Coastal Acid Sulfate Soils By Tidal Inundation: Geochemical Hysteresis Of Iron, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan

Associate Professor Edward D Burton

No abstract provided.

Go to article

Stockmarket Trading Using Fundamental Variables And Neural Networks, Bruce Vanstone, Gavin Finnie, Tobias Hahn Sep 2010

Stockmarket Trading Using Fundamental Variables And Neural Networks, Bruce Vanstone, Gavin Finnie, Tobias Hahn

Tobias Hahn

This paper uses a neural network methodology developed by Vanstone & Finnie[1] to develop a successful stockmarket trading system. The approach is based on these same 4 fundamental variables used within the Aby et al. fundamental trading strategies [2, 3], and demonstrates the important role neural networks have to play within complex and noisy environments, such as that provided by the stockmarket.

Go to article

Stockmarket Trading Using Fundamental Variables And Neural Networks, Bruce Vanstone, Gavin Finnie, Tobias Hahn Sep 2010

Stockmarket Trading Using Fundamental Variables And Neural Networks, Bruce Vanstone, Gavin Finnie, Tobias Hahn

Bruce Vanstone

This paper uses a neural network methodology developed by Vanstone & Finnie[1] to develop a successful stockmarket trading system. The approach is based on these same 4 fundamental variables used within the Aby et al. fundamental trading strategies [2, 3], and demonstrates the important role neural networks have to play within complex and noisy environments, such as that provided by the stockmarket.

Go to article

Improvements In Water Quality Following Restoring Tidal Exchange In An Acidified, Diked And Drained Estuarine Catchment, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton, D Smith, Michelle Martens, Angus Mcelnea, Colin Ahern, Bernard Powell, Luisa Stephens, Steven Wilbraham, Simon Van Heel Sep 2010

Improvements In Water Quality Following Restoring Tidal Exchange In An Acidified, Diked And Drained Estuarine Catchment, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton, D Smith, Michelle Martens, Angus Mcelnea, Colin Ahern, Bernard Powell, Luisa Stephens, Steven Wilbraham, Simon Van Heel

Associate Professor Edward D Burton

No abstract provided.

Go to article

Managing Floodplain Drains To Reduce Acid Export From Acid Sulfate Soil Backswamps, Richard Bush, Scott Johnston, Nadia Toppler, P Hurst, Edward Burton, Leigh Sullivan, Peter Slavich Sep 2010

Managing Floodplain Drains To Reduce Acid Export From Acid Sulfate Soil Backswamps, Richard Bush, Scott Johnston, Nadia Toppler, P Hurst, Edward Burton, Leigh Sullivan, Peter Slavich

Associate Professor Edward D Burton

No abstract provided.

Go to article

Catalytic Action Of Aqueous Ferrous Iron And Sulfide On The Transformation Of Iron Oxides In Acid Sulfate Soils, Richard Bush, Edward Burton, Leigh Sullivan, Scott Johnston Sep 2010

Catalytic Action Of Aqueous Ferrous Iron And Sulfide On The Transformation Of Iron Oxides In Acid Sulfate Soils, Richard Bush, Edward Burton, Leigh Sullivan, Scott Johnston

Associate Professor Edward D Burton

No abstract provided.

Go to article

Remediation Of Coastal Acid Sulfate Soils By Tidal Inundation: Effectiveness And Geochemical Implications, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan Sep 2010

Remediation Of Coastal Acid Sulfate Soils By Tidal Inundation: Effectiveness And Geochemical Implications, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan

Associate Professor Edward D Burton

The effects of restoring marine tidal inundation to a severely degraded acid sulfate soil landscape were investigated. Five years of regular tidal inundation led to substantial improvements in a range of key parameters used to assess soil and water quality. The pH of estuarine creeks improved dramatically following reintroduction of tidal inundation. Time series water quality and climatic data indicate a substantial decrease in the magnitude of creek acidification per given quantity of antecedent rainfall. The soil pH also increased by 2–3 units and titratable actual acidity (TAA) decreased by ~40–50 μmol H+ g-1 within former sulfuric horizons. Tidal inundation …

Go to article

A National Demonstration Site For Innovative Acid Sulfate Soil Research, East Trinity, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton, D Smith, Michelle Martens, Angus Mcelnea, Colin Ahern, Bernard Powell, Luisa Stephens, Steven Wilbraham, Simon Van Heel Sep 2010

A National Demonstration Site For Innovative Acid Sulfate Soil Research, East Trinity, Scott Johnston, Richard Bush, Leigh Sullivan, Edward Burton, D Smith, Michelle Martens, Angus Mcelnea, Colin Ahern, Bernard Powell, Luisa Stephens, Steven Wilbraham, Simon Van Heel

Associate Professor Edward D Burton

No abstract provided.

Go to article

First Prev Next Last