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2011

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Articles 10171 - 10200 of 10326

Full-Text Articles in Physical Sciences and Mathematics

Identifying The Stream Erosion Potential Of Cave Levels In Carter Cave State Resort Park, Kentucky, Usa, Eric Peterson, Brianne Jacoby, Toby Dogwiler Dec 2010

Identifying The Stream Erosion Potential Of Cave Levels In Carter Cave State Resort Park, Kentucky, Usa, Eric Peterson, Brianne Jacoby, Toby Dogwiler

Eric Wade Peterson

Cave levels, passages found at similar elevations and formed during the same constant stream base level event, reveal information about paleoclimates and karst geomorphology. The investigation presented here examines how Stream Power Index (SPI) relates to cave levels. The study area, Carter Caves State Resort Park (CCSRP), is a fluviokarst system in northeastern Kentucky containing multiple cave levels. SPI deter-mines the erosive power overland flow based on the assumption that flow accumulation and slope are proportional to potential for sediment entrainment. Part of this digital terrain analysis requires the creation of a flow accumulation raster from a digital elevation model …

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Wind-Speed Inversion From Hf Radar First-Order Backscatter Signal, W Shen, Klaus-Werner Gurgel, George Voulgaris, Thomas Schlick, D Stammer Dec 2010

Wind-Speed Inversion From Hf Radar First-Order Backscatter Signal, W Shen, Klaus-Werner Gurgel, George Voulgaris, Thomas Schlick, D Stammer

George Voulgaris

Land-based high-frequency (HF) radars have the unique capability of continuously monitoring ocean surface environments at ranges up to 200 km off the coast. They provide reliable data on ocean surface currents and under slightly stricter conditions can also give information on ocean waves. Although extraction of wind direction is possible, estimation of wind speed poses a challenge. Existing methods estimate wind speed indirectly from the radar derived ocean wave spectrum, which is estimated from the secondorder sidebands of the radar Doppler spectrum. The latter is extracted at shorter ranges compared with the first-order signal, thus limiting the method to short …

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Hayek's Philosophical Psychology, Leslie Marsh Dec 2010

Hayek's Philosophical Psychology, Leslie Marsh

Leslie Marsh

Hayek's philosophical psychology as set out in his The Sensory Order (1952) has, for the most part, been neglected. Despite being lauded by computer scientist grandee Frank Rosenblatt and by Nobel prize-winning biologist Gerald Edelman, cognitive scientists -- with a few exceptions -- have yet to discover Hayek's philosophical psychology. On the other hand, social theorists, Hayek's traditional disciplinary constituency, have only recently begun to take note and examine the importance of psychology in the complete Hayek corpus. This volume brings together for the first time state-of-the-art contributions from neuroscientists and philosophers of mind as well as economists and social …

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Implementation And Modification Of A Three-Dimensional Radiation Stress Formulation For Surf Zone And Rip-Current Applications, Nirnimesh Kumar, George Voulgaris, John Warner Dec 2010

Implementation And Modification Of A Three-Dimensional Radiation Stress Formulation For Surf Zone And Rip-Current Applications, Nirnimesh Kumar, George Voulgaris, John Warner

George Voulgaris

Regional Ocean Modeling System (ROMS v 3.0), a three-dimensional numerical ocean model, was previously enhanced for shallow water applications by including wave-induced radiation stress forcing provided through coupling to wave propagation models (SWAN, REF/DIF). This enhancement made it suitable for surf zone applications as demonstrated using examples of obliquely incident waves on a planar beach and rip current formation in longshore bar trough morphology (Haas and Warner, 2009). In this contribution, we present an update to the coupled model which implements a wave roller model and also a modified method of the radiation stress term based on Mellor (2008, 2011a,b,in …

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A Call For Standardization Of Aeolian Process Measurements: Moving Beyond Relative Case Studies, Thomas Barchyn, Chris Hugenholtz, Jean Ellis Dec 2010

A Call For Standardization Of Aeolian Process Measurements: Moving Beyond Relative Case Studies, Thomas Barchyn, Chris Hugenholtz, Jean Ellis

Jean Taylor Ellis

No abstract provided.

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Identification And Thermochemical Analysis Of High-Lignin Feedstocks For Biofuel And Biochemical Production, V. Mendu, A. Harman-Ware, M. Crocker, J. Jae, J. Stork, Samuel Morton, A. Placido, G. Huber, S. Debolt Dec 2010

Identification And Thermochemical Analysis Of High-Lignin Feedstocks For Biofuel And Biochemical Production, V. Mendu, A. Harman-Ware, M. Crocker, J. Jae, J. Stork, Samuel Morton, A. Placido, G. Huber, S. Debolt

Samuel A Morton

No abstract provided.

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Climate Change, Sustainable Development, And Ecosystems: 2010 Annual Report, John Dernbach Dec 2010

Climate Change, Sustainable Development, And Ecosystems: 2010 Annual Report, John Dernbach

John C. Dernbach

No abstract provided.

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Insider's Guide To Teaching With Mathematics For Elementary Teachers With Activity Manual, Sybilla Beck, Rachel Bishop-Ross Dec 2010

Insider's Guide To Teaching With Mathematics For Elementary Teachers With Activity Manual, Sybilla Beck, Rachel Bishop-Ross

Rachel E. Bishop-Ross

No abstract provided.

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High Power Efficiency Tandem Organic Light-Emitting Diodes Based On Bulk Heterojunction Organic Bipolar Charge Generation Layer, Yh Chen, Js Chen, Dg Ma, Dh Yan, Lx Wang, F.R. Zhu Dec 2010

High Power Efficiency Tandem Organic Light-Emitting Diodes Based On Bulk Heterojunction Organic Bipolar Charge Generation Layer, Yh Chen, Js Chen, Dg Ma, Dh Yan, Lx Wang, F.R. Zhu

Professor ZHU, Fu Rong

The significant enhancement in power efficiency of tandem organic light-emitting diodes (OLEDs) was achieved using bulk heterojunction organic bipolar charge generation layer (CGL), consisted of zinc phthalocyanine (ZcPc): fullerene (C60) blend. In addition to a significant enhancement in luminance and current efficiency this work yielded a maximum power efficiency of 21 lm/W measured for a tandem OLED, which is notably almost two times higher than that of a single-unit device, with a maximum power efficiency of 10.1 lm/W. The enhancement in power efficiency at higher luminance is also over 90%. The remarkable enhancement in power efficiency has been attributed to …

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Clustering With Exclusion Zones: Genomic Applications, Mark Segal, Yuanyuan Xiao, Fred Huffer Dec 2010

Clustering With Exclusion Zones: Genomic Applications, Mark Segal, Yuanyuan Xiao, Fred Huffer

Mark R Segal

Methods for formally evaluating the clustering of events in space or time, notably the scan statistic, have been richly developed and widely applied. In order to utilize the scan statistic and related approaches, it is necessary to know the extent of the spatial or temporal domains wherein the events arise. Implicit in their usage is that these domains have no “holes”—hereafter “exclusion zones”—regions in which events a priori cannot occur. However, in many contexts, this requirement is not met. When the exclusion zones are known, it is straightforward to correct the scan statistic for their occurrence by simply adjusting the …

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How To Lose As Little As Possible, Vittorio Addona, Stan Wagon, Herb Wilf Dec 2010

How To Lose As Little As Possible, Vittorio Addona, Stan Wagon, Herb Wilf

Stan Wagon, Retired

No abstract provided.

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Conduction And Thermal Properties Of A Proton Conducting Polymer Electrolyte Based On Poly (Epsilon-Caprolactone), Siti Rohana Majid, Woo H. J., Arof A. K. Dec 2010

Conduction And Thermal Properties Of A Proton Conducting Polymer Electrolyte Based On Poly (Epsilon-Caprolactone), Siti Rohana Majid, Woo H. J., Arof A. K.

Siti Rohana Majid

A proton conducting polymer electrolyte based on poly(epsilon-caprolactone) (PCL) complexed with different concentrations of ammonium thiocyanate (NH(4)SCN) salt has been investigated. The ionic conductivity of the solid polymer electrolyte (SPE) of pure PCL obtained at room temperature is 1.86 x 10(-11) S cm(-1). The maximum ionic conductivity achieved in the solution-cast films at room temperature is 1.01 x 10(-4) S cm(-1) for PCL incorporated with 26 wt.% NH(4)SCN. The calculated dielectric constant at selected frequencies follows the same trend as conductivity, concluding an increase in number density of ions with the salt content. DSC thermogram shows that the degree of …

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Webmapreduce: An Accessible And Adaptable Tool For Teaching Map-Reduce Computing, Elizabeth Shoop, Richard Brown, Patrick Garrity, Timothy Yates Dec 2010

Webmapreduce: An Accessible And Adaptable Tool For Teaching Map-Reduce Computing, Elizabeth Shoop, Richard Brown, Patrick Garrity, Timothy Yates

Elizabeth Shoop

No abstract provided.

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Preparation And Characterization Of Magnesium Ion Gel Polymer Electrolytes For Application In Electrical Double Layer Capacitors, Siti Rohana Majid, Asmara S. N., Kufian M. Z., Arof A. K. Dec 2010

Preparation And Characterization Of Magnesium Ion Gel Polymer Electrolytes For Application In Electrical Double Layer Capacitors, Siti Rohana Majid, Asmara S. N., Kufian M. Z., Arof A. K.

Siti Rohana Majid

This work describes the preparation and characterization of poly (methyl methacrylate) (PMMA) based gel polymer electrolytes with magnesium triflate (Mg(CF(3)SO(3))(2)) as the ion providing salt. Liquid electrolytes containing 0.4 M Mg(CF(3)SO(3))(2) in solvents comprising different ratios of ethylene carbonate (EC) and diethyl carbonate (DEC) have been prepared at room temperature. The highest conducting electrolyte contains EC and DEC in the weight ratio of 2:1. To the highest conducting liquid electrolyte, 25-50 wt.% PMMA has been added and the mixtures were heated at 80 degrees C for 2 min to form gel polymer electrolytes. The gel electrolyte with composition 40 wt.% …

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Highly Fluorous Complexes Of Nickel, Palladium And Platinum: Solubility And Catalysis In High Pressure Co2, Brad Berven, George Koutsantonis, Brian Skelton, Robert Trengove, Allan White Dec 2010

Highly Fluorous Complexes Of Nickel, Palladium And Platinum: Solubility And Catalysis In High Pressure Co2, Brad Berven, George Koutsantonis, Brian Skelton, Robert Trengove, Allan White

Brad Berven

A variety of Group 10 metal complexes [MXY(dfppp)], M = Ni, X, Y = Cl, Br, M = Pd, Pt, X, Y = Cl or CH3, containing the recently reported highly fluorous diphosphine ligand, dfppp, 1,3-bis[di(fluoroponytail)phosphino]propane, {(p-F13C6C6H4)2P}2(CH2)3 have been synthesised. They have been characterised by NMR, mass spectrometry and microanalysis, with two platinum complexes, [PtCl2(dfppp)] and [PtClMe(dfppp)], structurally characterised by single crystal X-ray diffraction studies. The highly fluorous nature of the ligands affords the complexes good supercritical CO2 solubility as measured by supercritical fluid extraction (SFE), and has allowed for the copolymerisation of CO and ethylene using [PdClMe(dfppp)] as the …

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Rejoinder: Estimation Issues For Copulas Applied To Marketing Data, Peter Danaher, Michael Smith Dec 2010

Rejoinder: Estimation Issues For Copulas Applied To Marketing Data, Peter Danaher, Michael Smith

Michael Stanley Smith

Estimating copula models using Bayesian methods presents some subtle challenges, ranging from specification of the prior to computational tractability. There is also some debate about what is the most appropriate copula to employ from those available. We address these issues here and conclude by discussing further applications of copula models in marketing.

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Creating The Law Of Environmentally Sustainable Economic Development, John Dernbach Dec 2010

Creating The Law Of Environmentally Sustainable Economic Development, John Dernbach

John C. Dernbach

This article argues that a key to sustainability is redirecting the law of economic development. From a historical perspective, sustainable development is an effort to integrate environmental protection and restoration with development. As a result, it is not possible to fully understand sustainable development unless we understand what development means. While that term is reasonably well understood at the international level, our closest analogue in the United States is not development in general but rather economic development. A great many recently enacted laws that move the United States toward sustainability can be understood as economic development laws. By understanding these …

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Direct Consequences Of The Basic Ballot Theorem, Tamas Lengyel Dec 2010

Direct Consequences Of The Basic Ballot Theorem, Tamas Lengyel

Tamas Lengyel

We use only the classic basic ballot result and simple combinatorial arguments to derive the distributions of the first passage time and the number of visits in the usual random walk model.

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Forecasting Television Ratings, Peter Danaher, Tracey Dagger, Michael Smith Dec 2010

Forecasting Television Ratings, Peter Danaher, Tracey Dagger, Michael Smith

Michael Stanley Smith

Despite the state of flux in media today, television remains the dominant player globally for advertising spend. Since television advertising time is purchased on the basis of projected future ratings, and ad costs have skyrocketed, there is increasing pressure to forecast television ratings accurately. Previous forecasting methods are not generally very reliable and many have not been validated, but more distressingly, none have been tested in today’s multichannel environment. In this study we compare 8 different forecasting models, ranging from a naïve empirical method to a state-of-the-art Bayesian model-averaging method. Our data come from a recent time period, 2004-2008 in …

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Cross-Discipline Perceptions Of The Undergraduate Research Experience, Chris Craney, Tara Mckay, April Mazzeo, Janet Morris, Cheryl Prigodich, Robert De Groot Dec 2010

Cross-Discipline Perceptions Of The Undergraduate Research Experience, Chris Craney, Tara Mckay, April Mazzeo, Janet Morris, Cheryl Prigodich, Robert De Groot

Chris L. Craney

The interest in undergraduate research as a “touchstone” for the integration of research and education (Bauer & Bennett, 2003, p. 212) has led to a large number of programs and models supported by a variety of public and private sources (Seymour, Hunter, Laursen, & DeAntoni, 2004). Assessments have examined students’ progress toward advanced degrees, clarification of career path decisions, understanding of research-associated skills or attitudes, and access to research (Denofrio, Russell, Lopato, & Lu, 2007; Frantz, De Haan, Demetrikopoulos, & Carruth, 2006; Hunter, Laursen, & Seymour, 2006; Hurtado, Eagan, Cabrera, Lin, Park, & Lopez, 2008; Ishiyama, 2002; Lopatto, 2004; Russell, …

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Differentiable Cortical Networks For Inferences Concerning People’S Intentions Versus Physical Causality, Robert Mason, Marcel Just Dec 2010

Differentiable Cortical Networks For Inferences Concerning People’S Intentions Versus Physical Causality, Robert Mason, Marcel Just

Marcel Adam Just

No abstract provided.

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Astrophysical Mechanisms For Pulsar Spindown, Eric Addison Dec 2010

Astrophysical Mechanisms For Pulsar Spindown, Eric Addison

Eric Addison

Pulsars are astrophysical sources of pulsed electromagnetic radiation. The pulses have a variety of shapes in the time-domain, and the pulse energy generally peaks in the radio spectrum. The accepted models theorize that pulsars are rapidly rotating neutron stars with strong dipolar magnetic fields. Current models predict that rotational kinetic energy is extracted from the pulsar in the form of electromagnetic and gravitational radiation, causing it to slowly lose rotational speed, or “spin down”. This spindown can be characterized by a single value n, known as the braking index. This report will review basic characteristics of pulsars, including short treatments …

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An Assessment Of Coastal Land-Use And Land-Cover Change From 1974-2008 In The Vicinity Of Mobile Bay, Alabama, Jean Ellis, Joseph Spruce, Roberta Swann, James Smoot, Kent Hilbert Dec 2010

An Assessment Of Coastal Land-Use And Land-Cover Change From 1974-2008 In The Vicinity Of Mobile Bay, Alabama, Jean Ellis, Joseph Spruce, Roberta Swann, James Smoot, Kent Hilbert

Jean Taylor Ellis

No abstract provided.

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Servicemap: Providing Map And Gps Assistance To Service Composition In Bioinformatics, Wei Tan, Jia Zhang, Ravi Madduri, Ian Foster, David De Roure, Carole Goble Dec 2010

Servicemap: Providing Map And Gps Assistance To Service Composition In Bioinformatics, Wei Tan, Jia Zhang, Ravi Madduri, Ian Foster, David De Roure, Carole Goble

Jia Zhang

No abstract provided.

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The "Cash For Clunkers" Program: A Sustainability Evaluation, Marianne Tyrrell, John Dernbach Dec 2010

The "Cash For Clunkers" Program: A Sustainability Evaluation, Marianne Tyrrell, John Dernbach

John C. Dernbach

This article describes and evaluates the effectiveness of the Consumer Assistance to Recycle and Save Act of 2009, also known as the “Cash for Clunkers” legislation. Under this law, Congress authorized persons trading in older and less fuel-efficient motor vehicles for newer and more fuel-efficient vehicles to receive a voucher worth up to $4,500 toward the purchase of the new vehicle. The article reviews various studies assessing the effectiveness of this legislation based on economic, social, and environmental criteria. Because these criteria are consistent with the goals of sustainable development, the legislation provides important lessons for future efforts to achieve …

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A University-Oriented Web 2.0 Services Portal, Jia Zhang, Karthik Akula, Momtazul Momtazul Karim, Raghu Kumar Reddy Raghu Kumar Reddy Ariga Dec 2010

A University-Oriented Web 2.0 Services Portal, Jia Zhang, Karthik Akula, Momtazul Momtazul Karim, Raghu Kumar Reddy Raghu Kumar Reddy Ariga

Jia Zhang

No abstract provided.

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Rating: How Difficult Is It?, E. Sparling, Shilad Sen Dec 2010

Rating: How Difficult Is It?, E. Sparling, Shilad Sen

Shilad Sen

No abstract provided.

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Computers And Networks, Lisa Zilinski Dec 2010

Computers And Networks, Lisa Zilinski

Lisa Zilinski

Understanding how computers work requires knowledge of the physical structures and capabilities of the hardware, as well as how these capabilities are organized and controlled through software. Effective computer management also requires the ability to understand and support users' activities while at the same time anticipating potential threats to the system. Computing and communication technologies continue to evolve, which means that the system manager must also find ways to keep up with advances that improve the capability, reliability, and accessibility of these important tools for information management.

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Environmental Laws And Sustainability: An Introduction, John Dernbach, Joel Mintz Dec 2010

Environmental Laws And Sustainability: An Introduction, John Dernbach, Joel Mintz

John C. Dernbach

In this introduction to the special issue of Sustainability on environmental laws and sustainability, we attempt to synthesize key lessons from the issue’s ten substantive articles. These lessons involve the use of law to achieve integrated decision-making, the use of pre-existing laws to foster sustainability, the centrality of sub-national governments in achieving sustainability, the background law of unsustainable development, the growing importance of climate change, the need to use law to protect and restore ecological integrity, the importance of judicial review and nongovernmental organizations, the need to translate sustainability into specific legal principles, the challenge of creating an appropriate national …

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Cross-Validated Targeted Minimum-Loss-Based Estimation, Wenjing Zheng, Mark Van Der Laan Dec 2010

Cross-Validated Targeted Minimum-Loss-Based Estimation, Wenjing Zheng, Mark Van Der Laan

Wenjing Zheng

No abstract provided.

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