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

Physical Sciences and Mathematics Commons

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

2011

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 10111 - 10140 of 10284

Full-Text Articles in Physical Sciences and Mathematics

Spitzer Reveals What Is Behind Orion's Bar, Robert H. Rubin, Janet P. Simpson, C. R. O'Dell, Ian A. Mcnabb, Sean W. J. Colgan, Scott Y. Zhuge, Gary J. Ferland, Sergio A. Hidalgo Jan 2011

Spitzer Reveals What Is Behind Orion's Bar, Robert H. Rubin, Janet P. Simpson, C. R. O'Dell, Ian A. Mcnabb, Sean W. J. Colgan, Scott Y. Zhuge, Gary J. Ferland, Sergio A. Hidalgo

Physics and Astronomy Faculty Publications

We present Spitzer Space Telescope observations of 11 regions south-east (SE) of the Bright Bar in the Orion Nebula, along a radial from the exciting star θ1 Ori C, extending from 2.6 to 12.1 arcmin. Our Cycle 5 programme obtained deep spectra with matching Infrared Spectrograph (IRS) short-high (SH) and long-high (LH) aperture grid patterns. Most previous IR missions observed only the inner few arcmin (the ‘Huygens’ Region). The extreme sensitivity of Spitzer in the 10–37 μm spectral range permitted us to measure many lines of interest to much larger distances from θ1 Ori C. Orion is the …


Kentucky Water Resources Research Institute Annual Technical Report Fy 2010, Kentucky Water Resources Research Institute, University Of Kentucky Jan 2011

Kentucky Water Resources Research Institute Annual Technical Report Fy 2010, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Annual Technical Reports (USGS’s 104b Grant Program)

The 2010 Annual Technical Report for Kentucky consolidates reporting requirements for the Section 104(b) base grant award into a single document that includes: 1) a synopsis of each research project that was conducted during the period, 2) citations for related publications, reports, and presentations, 3) a description of information transfer activities, 4) a summary of student support during the reporting period, and 5) notable awards and achievements during the year.


Relativistic Red-Black Trees, Philip William Howard, Jonathan Walpole Jan 2011

Relativistic Red-Black Trees, Philip William Howard, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Operating system performance and scalability on sharedmemory many-core systems depends critically on efficient access to shared data structures. Scalability has proven difficult to achieve for many data structures. In this paper we present a novel and highly scalable concurrent red-black tree. Red-black trees are widely used in operating systems, but typically exhibit poor scalability. Our red-black tree has linear read scalability, uncontended read performance that is at least 25% faster than other known approaches, and deterministic lookup times for a given tree size, making it suitable for realtime applications.


A Framework For Transparent Depression Classification In College Settings Via Mining Internet Usage Patterns, Raghavendra Kotikalapudi Jan 2011

A Framework For Transparent Depression Classification In College Settings Via Mining Internet Usage Patterns, Raghavendra Kotikalapudi

Masters Theses

Depression is a serious mental health problem affecting the mind and body of people in our society. As of today, depression affects about 5 to 7% of the American population, which roughly translates to 14 million people! A particularly worrying concern these days is the increasing incidence of depression among college students. The problem is so severe that many US campuses have dedicated centers with mental health professionals catering to students needs. Although there are very effective treatments for depression, studies report that ~80% of depressed students do not seek any help due to the lack of perception of the …


The Ordering Requirements Of Relativistic And Reader-Writer Locking Approaches To Shared Data Access, Philip William Howard, Josh Triplett, Jonathan Walpole, Paul E. Mckenney Jan 2011

The Ordering Requirements Of Relativistic And Reader-Writer Locking Approaches To Shared Data Access, Philip William Howard, Josh Triplett, Jonathan Walpole, Paul E. Mckenney

Computer Science Faculty Publications and Presentations

The semantics of reader-writer locks allow read-side concurrency. Unfortunately, the locking primitives serialize access to the lock variable to an extent that little or no concurrency is realized in practice for small critical sections. Relativistic programming is a methodology that also allows read- side concurrency. Relativistic programming uses dfferent ordering constraints than reader-writer locking. The different ordering constraints allow relativistic readers to proceed without synchronization so relativistic readers scale even for very short critical sections. In this paper we explore the diferences between the ordering constraints for reader-writer locking and relativistic programs. We show how and why the dfferent ordering …


Physical And Electrical Characterization Of Triethanolamine Based Sensors For No₂ Detection And The Influence Of Humidity On Sensing Response, Zachariah Marcus Peterson Jan 2011

Physical And Electrical Characterization Of Triethanolamine Based Sensors For No₂ Detection And The Influence Of Humidity On Sensing Response, Zachariah Marcus Peterson

Dissertations and Theses

Triethanolamine (TEA) is a semiconducting polymer which exhibits a resistance change when exposed to various gases. The polymer also exhibits a number of reactions with nitrogen dioxide, with the reaction products being heavily dependent on the presence or absence of water vapor. Previous studies have attempted the incorporation of a TEA-carbon nanoparticle composite as the active sensing layer in a chemresistive sensor for detection of NO₂. The incorporation of carbon nanoparticles in the polymer nanocomposite was thought to amplify the sensor's response. There are a number of chemical reactions that can occur between TEA and NO₂, with the reaction products …


Stochastic Dynamics Of Gene Transcription, Yan Xie Jan 2011

Stochastic Dynamics Of Gene Transcription, Yan Xie

Theses and Dissertations--Statistics

Gene transcription in individual living cells is inevitably a stochastic and dynamic process. Little is known about how cells and organisms learn to balance the fidelity of transcriptional control and the stochasticity of transcription dynamics. In an effort to elucidate the contribution of environmental signals to this intricate balance, a Three State Model was recently proposed, and the transcription system was assumed to transit among three different functional states randomly.

In this work, we employ this model to demonstrate how the stochastic dynamics of gene transcription can be characterized by the three transition parameters. We compute the probability distribution of …


Finding Haystacks With Needles: Ranked Search For Data Using Geospatial And Temporal Characteristics, Veronika Margaret Megler, David Maier Jan 2011

Finding Haystacks With Needles: Ranked Search For Data Using Geospatial And Temporal Characteristics, Veronika Margaret Megler, David Maier

Computer Science Faculty Publications and Presentations

The past decade has seen an explosion in the number and types of environmental sensors deployed, many of which provide a continuous stream of observations. Each individual observation consists of one or more sensor measurements, a geographic location, and a time. With billions of historical observations stored in diverse databases and in thousands of datasets, scientists have difficulty finding relevant observations. We present an approach that creates consistent geospatial-temporal metadata from large repositories of diverse data by blending curated and automated extracts. We describe a novel query method over this metadata that returns ranked search results to a query with …


Modeling Habitat Associations For The Common Loon (Gavia Immer) At Multiple Scales In Northeastern North America, Anne Kuhn, Jane Copeland, John Cooley, Harry Vogel, Kate Taylor, Diane Nacci, Peter V. August Jan 2011

Modeling Habitat Associations For The Common Loon (Gavia Immer) At Multiple Scales In Northeastern North America, Anne Kuhn, Jane Copeland, John Cooley, Harry Vogel, Kate Taylor, Diane Nacci, Peter V. August

Natural Resources Science Faculty Publications

Common Loon (Gavia immer) is considered an emblematic and ecologically important example of aquatic-dependent wildlife in North America. The northern breeding range of Common Loon has contracted over the last century as a result of habitat degradation from human disturbance and lakeshore development. We focused on the state of New Hampshire, USA, where a long-term monitoring program conducted by the Loon Preservation Committee has been collecting biological data on Common Loon since 1976. The Common Loon population in New Hampshire is distributed throughout the state across a wide range of lake-specific habitats, water quality conditions, and levels of …


Imaging The Extracellular Ph Of Tumors By Mri After Injection Of A Single Cocktail Of T1 And T2 Contrast Agents, Gary V. Martinez, Xiaomeng Zhang, María L. García-Martín, David L. Morse, Mark Woods, A. Dean Sherry, Robert J. Gillies Jan 2011

Imaging The Extracellular Ph Of Tumors By Mri After Injection Of A Single Cocktail Of T1 And T2 Contrast Agents, Gary V. Martinez, Xiaomeng Zhang, María L. García-Martín, David L. Morse, Mark Woods, A. Dean Sherry, Robert J. Gillies

Chemistry Faculty Publications and Presentations

The extracellular pH (pH(e) ) of solid tumors is acidic, and there is evidence that an acidic pH(e) is related to invasiveness. Herein, we describe an MRI single-infusion method to measure pH(e) in gliomas using a cocktail of contrast agents (CAs). The cocktail contained gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate (GdDOTA-4AmP) and dysprosium-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetrakis(methylenephosphonic acid) (DyDOTP), whose effects on relaxation are sensitive and insensitive to pH, respectively. The Gd-CA dominated the spin-lattice relaxivity ΔR(1) , whereas the Dy-CA dominated the spin-spin relaxivity ΔR(2)*. The ΔR(2)* effects were used to determine the pixel-wise concentration of [Dy] which, in turn, was used to calculate a value for [Gd] …


Holomorphic Motions And Extremal Annuli, Zhe Wang Jan 2011

Holomorphic Motions And Extremal Annuli, Zhe Wang

Dissertations, Theses, and Capstone Projects

Holomorphic motions, soon after they were introduced, became an important subject in complex analysis. It is now an important tool in the study of complex dynamical systems and in the study of Teichmuller theory. This thesis serves on two purposes: an expository of the past developments and a discovery of new theories.

First, I give an expository account of Slodkowski's theorem based on the proof given by Chirka. Then I present a result about infinitesimal holomorphic motions. I prove the |ε log ε| modulus of continuity for any infinitesimal holomorphic motion. This proof is a very well application of Schwarz's …


Aerosol Climatology Over Nile Delta Based On Modis, Misr And Omi Satellite Data, H. S. Marey, J. C. Gille, Hesham El-Askary, E. A. Shalaby, Mohamed El Raey Jan 2011

Aerosol Climatology Over Nile Delta Based On Modis, Misr And Omi Satellite Data, H. S. Marey, J. C. Gille, Hesham El-Askary, E. A. Shalaby, Mohamed El Raey

Mathematics, Physics, and Computer Science Faculty Articles and Research

Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the “black cloud” during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr period from 2000–2009. Significant monthly variability is observed in the AOD with maxima in April or May (_0.5) and October (_0.45), and a …


Two-Language, Two-Paradigm Introductory Computing Curriculum Model And Its Implementation, Vladimir Zanev, Atanas Radenski Jan 2011

Two-Language, Two-Paradigm Introductory Computing Curriculum Model And Its Implementation, Vladimir Zanev, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

This paper analyzes difficulties with the introduction of object-oriented concepts in introductory computing education and then proposes a two-language, two-paradigm curriculum model that alleviates such difficulties. Our two-language, two-paradigm curriculum model begins with teaching imperative programming using Python programming language, continues with teaching object-oriented computing using Java, and concludes with teaching object-oriented data structures with Java.


Estimation Of Nox Emissions From Delhi Using Car Max-Doas Observations And Comparison With Omi Satellite Data, R. Shaiganfar, S. Beirle, Manish Sharma, A. Chauhan, Ramesh P. Singh, T. Wagner Jan 2011

Estimation Of Nox Emissions From Delhi Using Car Max-Doas Observations And Comparison With Omi Satellite Data, R. Shaiganfar, S. Beirle, Manish Sharma, A. Chauhan, Ramesh P. Singh, T. Wagner

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present the first Multi-Axis-(MAX-) DOAS observations in India performed during April 2010 and January 2011 in Delhi and nearby regions. The MAX-DOAS instrument was mounted on a car roof, which allowed us to perform measurements along individual driving routes. From car MAX-DOAS observations along closed circles around Delhi, together with information on wind speed and direction, the NOx emissions from the greater Delhi area were determined: our estimate of 4.4 x 10(25) molecules s(-1) is found to be slightly lower than the corresponding emission estimates using the EDGAR emission inventory and substantially smaller compared to a recent study by …


Contrasting Aerosol Trends Over South Asia During The Last Decade Based On Modis Observations, Dimitris G. Kaskaoutis, Shailesh Kumar Kharol, P. R. Sinha, Ramesh P. Singh, K. V. S. Badarinath, Waseem Mehdi, Manish Sharma Jan 2011

Contrasting Aerosol Trends Over South Asia During The Last Decade Based On Modis Observations, Dimitris G. Kaskaoutis, Shailesh Kumar Kharol, P. R. Sinha, Ramesh P. Singh, K. V. S. Badarinath, Waseem Mehdi, Manish Sharma

Mathematics, Physics, and Computer Science Faculty Articles and Research

Atmospheric aerosols over south Asia constitute a major environmental and climate issue. Thus, extensive land and cruise campaigns have been conducted over the area focusing on investigating the aerosol properties and climate implications. Except from the ground-based instrumentation, several studies dealt with analyzing the aerosol properties from space, focusing mainly on the spatial distribution of the aerosol optical depth (AOD) and possible feedbacks of aerosols on the monsoon system. However, except from some works using ground-based instrumentation or satellite observations over a specific region, there is lack of studies dealing with monitoring of the aerosol trend over south Asia. The …


Magnetic Properties Of The Bishop Ash In The San Andreas Fault Borderlands, Becky Strauss Jan 2011

Magnetic Properties Of The Bishop Ash In The San Andreas Fault Borderlands, Becky Strauss

Honors Papers

The San Andreas Fault marks one of the most tectonically active regions of the United States, producing frequent earthquakes that have decimated major population centers throughout central and southern California. Its northern regions have been thoroughly studied, but the complex behavior of the southeast portion of the fault is often neglected, in spite of its potential to nucleate a major earthquake within the next few centuries. In this study, I examined the magnetic traits of the Bishop Ash, a well-dated marker horizon of volcanic ash, to assess deformation adjacent to this part of the fault at hand-sample scale. To this …


Quaternionic Hermitian Spinor Systems And Compatibility Conditions, Alberto Damiano, David Eelbode, Irene Sabadini Jan 2011

Quaternionic Hermitian Spinor Systems And Compatibility Conditions, Alberto Damiano, David Eelbode, Irene Sabadini

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we show that the systems introduced in [12] and [22] are equivalent, both giving the notion of quaternionic Hermitian monogenic functions. This makes it possible to prove that the free resolution associated to the system is linear in any dimension, and that the first cohomology module is nontrivial, thus generalizing the results in [22]. Furthermore, exploiting the decomposition of the spinor space into sp(m)-irreducibles, we find a certain number of "algebraic" compatibility conditions for the system, suggesting that the usual spinor reduction is not applicable.


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 …


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 …


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 …


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 …


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.


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.


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.


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.


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 …


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 …


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.


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 …


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.