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2007

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Articles 2461 - 2490 of 6758

Full-Text Articles in Physical Sciences and Mathematics

Corrosion Electrochemical Behavior Of Aluminum Flake Pigmented Water-Borne Epoxy Coating On Carbon Steel In Nacl Solution, Li-Li Xue, Li-Kun Xu, Qing-Fen Li, Hong-Qing Song, Wen-Juan Zhou, Guang-Zhang Chen May 2007

Corrosion Electrochemical Behavior Of Aluminum Flake Pigmented Water-Borne Epoxy Coating On Carbon Steel In Nacl Solution, Li-Li Xue, Li-Kun Xu, Qing-Fen Li, Hong-Qing Song, Wen-Juan Zhou, Guang-Zhang Chen

Journal of Electrochemistry

The corrosion electrochemical behavior of a water-borne epoxy coating pigmented with aluminum flake on carbon steel with artificial scratch defect was studied in 3.5% NaCl solution using electrochemical impedance spectroscopy(EIS)and scanning vibrating electrode technique(SVET).The results indicated that the defect presented anodic electroactivity at the initial stage of immersion,which extended gradually with time from the scratch into the neighboring coating,lowering the coating impedance.With further immersion,however,the electroactivity of the coating/steel interface decreased significantly due to the self-repairing of the corrosion products,causing an obvious increase of the coating impedance.In the later period of immersion,more scattered electroactive areas appeared under the coating because of …


Modification Of Electrolytic Manganese Dioxide, Shu-Rong Ding, Xin-Hai Li, Zhi-Xing Wang, Hua-Jun Guo May 2007

Modification Of Electrolytic Manganese Dioxide, Shu-Rong Ding, Xin-Hai Li, Zhi-Xing Wang, Hua-Jun Guo

Journal of Electrochemistry

The EMD samples coated with CMD-Bi compound were prepared by liquid-phase surface treatment method.XRD and SEM research indicated that the modified manganese dioxide,i.e,EMD/CMD-Bi,could keep γ-MnO2 crystal structure of EMD and had more pores on its surface with an obvious floccule layer.Electrochemical test indicated that the second electron reduction peak current increased by 1.5 times and the discharge capacity increased by 40.8% and 78.3% respectively than that of pure EMD electrode under the condition of-0.8 V(vs.Hg/HgO)cut-off voltage at 30.8 mA/g and 102.7 mA/g current density.


Study On The Electrochemical Extraction Of Oxygen And Influence Factors Of Oxygen Purity, Xiao-Ke Zhi, Guang-Chuan Liang, Xiu-Qin Ou, Shu-Guang Liu, Bin Han May 2007

Study On The Electrochemical Extraction Of Oxygen And Influence Factors Of Oxygen Purity, Xiao-Ke Zhi, Guang-Chuan Liang, Xiu-Qin Ou, Shu-Guang Liu, Bin Han

Journal of Electrochemistry

A method for the electrochemical extraction of oxygen is prasented.The concentration of HO2-ions and the purity of oxygen were measured by KMnO4 standard method,and by cuprammonium absorb method respectively.Effect of the membrane and the spacing between cathode and anode on the purity of oxygen were also tested.The experiment results were showed that the system could work continuously above 500h and the purity of oxygen was above 99.8% when using proper membrane at 80 mA·cm-2 current density,Electrochemical reaction included 4e reacting course and 2e reacting course,the ratio of 2e reaction is about 38%~44% of the whole reaction.


Voltammetric Behavior And Electrocatalytic Properties Of Hemoglobin At Glassy Carbon Electrode Modified With Lauric Acid, Xin-Rui Miao, Xu-Hong Zhang, Ying Xie May 2007

Voltammetric Behavior And Electrocatalytic Properties Of Hemoglobin At Glassy Carbon Electrode Modified With Lauric Acid, Xin-Rui Miao, Xu-Hong Zhang, Ying Xie

Journal of Electrochemistry

The electrochemical behavior of hemoglobin at glassy carbon(GC)electrode modified with Lauric Acid was studied.In the potential of +0.6~-0.7 V(vs.Ag/AgCl),an irreversible cathodic peak was observed at-0.3 V at the scan rate of 20 mV·s-1.In the medium of 0.02 mol·L-1 KH2PO4-Na2HPO4(pH 7.0),ip increased with the increasing concentration of Hb and the value of pH.The peak currents were proportional to the concentrations of hemoglobin in the range of 1.00×10-8~5.00×10-9 mol·L-1 and 1.92×10-6~2.06×10-7 mol·L-1.The data was analyzed in details by simulating in order to obtain more information and reaction mechanism of Hb on modified electrode.The electrode can be used as an approach for determining …


Study On The Contribution Of Cobalt Additives To Foam Nickel Electrodes, Xiao-Feng Li, Tong-Chi Xia, Shao-Peng Yi, Xiu-Juan Gu, Yu-Lin Song May 2007

Study On The Contribution Of Cobalt Additives To Foam Nickel Electrodes, Xiao-Feng Li, Tong-Chi Xia, Shao-Peng Yi, Xiu-Juan Gu, Yu-Lin Song

Journal of Electrochemistry

Two incorporation ways of the cobalt additives into foam nickel electrodes,i.e.the co-precipitated and admixed method are used.The results of X-ray diffraction(XRD),cyclic voltammetry,electrochemical impedance spectrum(EIS)and galvanostatic charge-discharge curves show that(Ⅰ)there is a decrease in intensity and increase in half peak breadths of the diffraction peaks of Ni(OH)2 with co-precipitated cobalt additive;(Ⅱ)the electrochemical activity of nickel hydroxide can be improved by both incorporation ways and the effect of admixed CoO is more notable;(Ⅲ)β-CoOOH derived from admixed CoO is not stable at lower potential,thus results in an irreversible capacity loss of nickel-metal-hydride(Ni-MH)battery after imposed overdischarged-state storage.


Square Wave Stripping Voltammetric Behaviors Of Actinomycin D On Glod Electrode And Its Application, Qing-Tao Zhu, Fang Liao, Xiao-Ying He May 2007

Square Wave Stripping Voltammetric Behaviors Of Actinomycin D On Glod Electrode And Its Application, Qing-Tao Zhu, Fang Liao, Xiao-Ying He

Journal of Electrochemistry

The electrochemical behaviors of Actinomycin D(ACTD)at glod electrode were investigated by square wave stripping voltammeter in the KH2PO4-Na2HPO4 buffer solution(pH=5.90).The sensitive oxidation peak of ACTD was observed and the potential peak for ACTD is-0.17 V(vs.SCE).The Experimental parameters,such as pH value,amplitude,accumulation potential and time were optimized,and a direct electroanalytical method for determining ACTD was developed.The peak currents were proportional to the concentration of ACTD in the range of 0.1μmol·L-1~10.0μmol·L-1,and the linear regression coefficient equaled 0.9991.The detection limit for ACTD was 1.0×10-8mol·L-1.


Study On The Electrogeneration And Properties Of Superoxide Ion In Aprotic Media By Using Carbon Nanotubes Powder Microelectrode, Ying-Liang Wei, Chen Shao, Hui Feng May 2007

Study On The Electrogeneration And Properties Of Superoxide Ion In Aprotic Media By Using Carbon Nanotubes Powder Microelectrode, Ying-Liang Wei, Chen Shao, Hui Feng

Journal of Electrochemistry

Multi-wall carbon nanotubes are filled in the cavity at the tip of a microelectrode to form a carbon nanotubes powder microelectrode(CNTs-PME).The CNTs-PME is used to study the electrochemical reduction of oxygen in aprotic media.It is a nearly reversible redox process of the O2/O·-2 couple at the CNTs-PME in the dimethyl sulfoxide(DMSO)solution.The heterogeneous electron transfer rate constant(ks)can be measured by steady-state voltammogram and the result is 9.8 10-3cm /s.As a weak oxidant,the reaction of O·-2 with epinephrine was studied by cyclic voltammetry.Additionally,the reaction of O·-2 with benzoic acid was also discussed in detail.


Electrochemical Behavior And Determination Of Β,Β-Dimethyl-Acry-Lalkannin, Li-Qing Lin, Jing-Hua Chen, Hong-Yan Wan, Xin-Hua Lin May 2007

Electrochemical Behavior And Determination Of Β,Β-Dimethyl-Acry-Lalkannin, Li-Qing Lin, Jing-Hua Chen, Hong-Yan Wan, Xin-Hua Lin

Journal of Electrochemistry

The electrochemical behavior of the β,β-dimethyl-acry-lalkannin and a novel differential pulse voltammetric method for the determination of the β,β-DAL content were studied.Experiments indicated that the β,β-DAL has excellent adsorbability and the electrochemical reaction is a reversible two-electro and two-proton process.In phosphate buffer solution(pH 4.6),the differential pulse voltammograms for β,β-DAL reduction signals from +0.8~-0.4 V were monitored.The relationship between reduction peak current and concentration of β,β-DAL is linear in the range of 1.3×10-7~ 1.7×10-6 mol/L(r=0.9996).The detection limit is 4.0×10-8 mol/L.This method is sensitive and reliable for the determination of the β,β-DAL in radix with satisfactory results.


Spectral Variability Of The Particulate Backscattering Ratio, A. L. Whitmire, E. Boss, T. J. Cowles, W. S. Pegau May 2007

Spectral Variability Of The Particulate Backscattering Ratio, A. L. Whitmire, E. Boss, T. J. Cowles, W. S. Pegau

Marine Sciences Faculty Scholarship

The spectral dependency of the particulate backscattering ratio is relevant in the fields of ocean color inversion, light field modeling, and inferring particle properties from optical measurements. Aside from theoretical predictions for spherical, homogeneous particles, we have very limited knowledge of the actual in situ spectral variability of the particulate backscattering ratio. This work presents results from five research cruises that were conducted over a three-year period. Water column profiles of physical and optical properties were conducted across diverse aquatic environments that offered a wide range of particle populations. The main objective of this research was to examine the behavior …


Influence Of Lateral And Top Boundary Conditions On Regional Air Quality Prediction: A Multiscale Study Coupling Regional And Global Chemical Transport Models, Youhua Tang, Gregory R. Carmichael, Narisara Thongbongchoo, Tianfeng Chai, Larry Horowitz, R B. Pierce, J Al-Saadi, G G. Pfister, Jeffrey Vukovich, Melody A. Avery, Glen Sachse, Thomas B. Ryerson, J S. Holloway, E L. Atlas, F Flocke, Rodney J. Weber, L Gregory Huey, Jack E. Dibb, David G. Streets, William H. Brune May 2007

Influence Of Lateral And Top Boundary Conditions On Regional Air Quality Prediction: A Multiscale Study Coupling Regional And Global Chemical Transport Models, Youhua Tang, Gregory R. Carmichael, Narisara Thongbongchoo, Tianfeng Chai, Larry Horowitz, R B. Pierce, J Al-Saadi, G G. Pfister, Jeffrey Vukovich, Melody A. Avery, Glen Sachse, Thomas B. Ryerson, J S. Holloway, E L. Atlas, F Flocke, Rodney J. Weber, L Gregory Huey, Jack E. Dibb, David G. Streets, William H. Brune

Earth Sciences

The sensitivity of regional air quality model to various lateral and top boundary conditions is studied at 2 scales: a 60 km domain covering the whole USA and a 12 km domain over northeastern USA. Three global models (MOZART-NCAR, MOZART-GFDL and RAQMS) are used to drive the STEM-2K3 regional model with time-varied lateral and top boundary conditions (BCs). The regional simulations with different global BCs are examined using ICARTT aircraft measurements performed in the summer of 2004, and the simulations are shown to be sensitive to the boundary conditions from the global models, especially for relatively long-lived species, like CO …


Dumbots: Unexpected Botnets Through Networked Embedded Devices, Kwang-Hyun Baek, Sergey Bratus, Sara Sinclair May 2007

Dumbots: Unexpected Botnets Through Networked Embedded Devices, Kwang-Hyun Baek, Sergey Bratus, Sara Sinclair

Computer Science Technical Reports

Currently, work on botnets focuses primarily on PCs. However, as lightweight computing devices with embedded operating systems become more ubiquitous, they present a new and very disturbing target for botnet developers. In this paper, we present both an empirical demonstration on a widely deployed multimedia box, as well as an evaluation of the deeper potential of these dumbots.


Hygroscopic Behavior Of Nacl-Bearing Natural Aerosol Particles Using Environmental Transmission Electron Microscopy, Matthew E. Wise, Trudi A. Semeniuk, Roelof Bruintjes, Scot T. Martin, Lynn M. Russell, Peter R. Buseck May 2007

Hygroscopic Behavior Of Nacl-Bearing Natural Aerosol Particles Using Environmental Transmission Electron Microscopy, Matthew E. Wise, Trudi A. Semeniuk, Roelof Bruintjes, Scot T. Martin, Lynn M. Russell, Peter R. Buseck

CUP Faculty Research

We used conventional and environmental transmission electron microscopes to determine morphology, composition, and water uptake of individual natural inorganic aerosol particles collected from industrial pollution plumes and from clean and polluted marine environments. Five particle types are described in detail. They range from relatively insoluble mineral grains to internally mixed particles containing NaCl with other soluble or relatively insoluble material. We studied the hygroscopic behavior of these particles from 0 to 100% relative humidity (RH). Relatively insoluble materials do not take up water over the experimental RH range. Single crystals of NaCl from both natural and laboratory sources have a …


Jet-Radius Dependence Of Inclusive-Jet Cross Sections In Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi May 2007

Jet-Radius Dependence Of Inclusive-Jet Cross Sections In Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi

Faculty Publications

Differential inclusive-jet cross sections have been measured for different jet radii in neutral current deep inelastic ep scattering for boson virtualities Q2 > 125 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb-1. Jets were identified in the Breit frame using the kT cluster algorithm in the longitudinally inclusive mode for different values of the jet radius R. Differential cross sections are presented as functions of Q2 and the jet transverse energy, ET, Bjet. The dependence on R of the inclusive-jet cross section has been measured for Q2 > 125 and 500 GeV2 and found to be …


Multivariate Searches For Single Top Quark Production With The D0 Detector, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration May 2007

Multivariate Searches For Single Top Quark Production With The D0 Detector, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We present a search for electroweak production of single top quarks in the s-channel (pp̅tb̅ + X) and t-channel (pp̅tqb̅ + X) modes.We have analyzed 230 pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider at a center-of-mass energy of √s = 1.96 TeV. No evidence for a single top quark signal is found. We set 95% confidence level upper limits on the production cross sections, based on binned likelihoods formed from a neural network output. The observed (expected) limits are 6.4 pb (4.5 pb) in the …


Interpreting Force Concept Inventory Scores: Normalizedgain And Sat Scores, Vincent P. Coletta, Jeffrey A. Phillips May 2007

Interpreting Force Concept Inventory Scores: Normalizedgain And Sat Scores, Vincent P. Coletta, Jeffrey A. Phillips

Physics Faculty Works

Preinstruction SAT scores and normalized gains (G) on the force concept inventory (FCI) were examined for individual students in interactive engagement (IE) courses in introductory mechanics at one high school (N=335) and one university (N=292), and strong, positive correlations were found for both populations (r=0.57 and r=0.46, respectively). These correlations are likely due to the importance of cognitive skills and abstract reasoning in learning physics. The larger correlation coefficient for the high school population may be a result of the much shorter time interval between taking the SAT and studying mechanics, because the SAT may provide a more current measure …


On Connections Between Univalent Harmonic Functions, Symmetry Groups, And Minimal Surfaces, Stephen M. Taylor May 2007

On Connections Between Univalent Harmonic Functions, Symmetry Groups, And Minimal Surfaces, Stephen M. Taylor

Theses and Dissertations

We survey standard topics in elementary differential geometry and complex analysis to build up the necessary theory for studying applications of univalent harmonic function theory to minimal surfaces. We then proceed to consider convex combination harmonic mappings of the form f=sf_1+(1-s) f_2 and give conditions on when f lifts to a one-parameter family of minimal surfaces via the Weierstrauss-Enneper representation formula. Finally, we demand two minimal surfaces M and M' be locally isometric, formulate a system of partial differential equations modeling this constraint, and calculate their symmetry group. The group elements generate transformations that when applied to a prescribed harmonic …


Interview With Paul Fischer, Professor Of Chemistry, Paul Fischer May 2007

Interview With Paul Fischer, Professor Of Chemistry, Paul Fischer

Chemistry Department Oral Histories

No abstract provided.


Usda/Aphis/Wildlife Services Research Needs Assessment 2006, Larry Clark, David Nelson, Kirk Gustad May 2007

Usda/Aphis/Wildlife Services Research Needs Assessment 2006, Larry Clark, David Nelson, Kirk Gustad

United States Department of Agriculture Wildlife Services: Staff Publications

Research Needs Assessment Report
Reassessment of WS Research Needs (NWRC Director memo)
WS Research Needs Assessment (WS Deputy Administrator memo to WS Program)
WS Research Needs Assessment (NWRC Director memo to WSNAC)
Current APHIS/WS Methods Development Research


Coronary Evaluation Using Multi-Detector Spiral Computed Tomography Angiography: Statistical Design And Analysis, William F. Mccarthy, Douglas R. Thompson, Bruce A. Barton May 2007

Coronary Evaluation Using Multi-Detector Spiral Computed Tomography Angiography: Statistical Design And Analysis, William F. Mccarthy, Douglas R. Thompson, Bruce A. Barton

COBRA Preprint Series

Contrast-enhanced multi-detector row spiral computed tomography (MDCT) has been introduced as a method for non-invasive visualization of coronary artery stenosis. To determine the diagnostic accuracy of MDCT coronary angiography, as compared to the “gold standard” invasive coronary angiography, sensitivity and specificity are estimated (95% Confidence Intervals). Three separate levels of estimation are computed: at the patient level, at the coronary artery level, and at the coronary artery segment level. We review the methodology for the estimation of sensitivity and specificity of non-clustered binary data (patient level analysis) and present a methodology for the estimation of sensitivity and specificity that considers …


The Analysis Of Pixel Intensity (Myocardial Signal Density) Data: The Quantification Of Myocardial Perfusion By Imaging Methods., William F. Mccarthy, Douglas R. Thompson May 2007

The Analysis Of Pixel Intensity (Myocardial Signal Density) Data: The Quantification Of Myocardial Perfusion By Imaging Methods., William F. Mccarthy, Douglas R. Thompson

COBRA Preprint Series

This paper described a number of important issues in the analysis of pixel intensity data, as well as approaches for dealing with these. We particularly emphasized the issue of clustering, which may be ubiquitous in studies of pixel intensity data. Clustering can take many forms, e.g., measurements of different sections of a heart or repeated measurements of the same research participant. Clustering typically has the effect of increasing variance estimates. When one fails to account for clustering, variance estimates may be unrealistically small, resulting in spurious significance. We illustrated several possible approaches to account for clustering, including adjusting standard errors …


Using Sawsdl For Semantic Service Interoperability, Kunal Verma, Amit P. Sheth May 2007

Using Sawsdl For Semantic Service Interoperability, Kunal Verma, Amit P. Sheth

Kno.e.sis Publications

No abstract provided.


Neutron Diffraction Analysis Of Magnetic Ordering In Ysr2cu2ruo8, William B. Yelon, Q. Cai, Jagat Lamsal, H. A. Blackstead, M. Kornecki, V. Awana, H. Kishan, S. Balamurugan, E. Takayama-Muromachi May 2007

Neutron Diffraction Analysis Of Magnetic Ordering In Ysr2cu2ruo8, William B. Yelon, Q. Cai, Jagat Lamsal, H. A. Blackstead, M. Kornecki, V. Awana, H. Kishan, S. Balamurugan, E. Takayama-Muromachi

Physics Faculty Research & Creative Works

The superconducting ruthenocuprates RESr2Cu2RuO8 (where RE is a rare earth or Y) have been interpreted as ferromagnetic superconductors, based on a strong response to applied field at the Ru Ńel temperature (around 130 K). However, neutron diffraction measurements on the Gd compound by Lynn [Phys. Rev. B 61, 1214964 (2000)] (using a separated isotope) show evidence only of antiferromagnetic order, while very limited data by Takagiwa [J. Phys. Soc. Jpn. 70, 333 (2001)] on the Y compound show one antiferromagnetic Bragg peak and possible coexisting ferromagnetism. We have studied a sample of YSr2Cu …


Functionalization Of Resorcinarenes And Study Of Antimicrobial Activity, Kirankirti Muppalla May 2007

Functionalization Of Resorcinarenes And Study Of Antimicrobial Activity, Kirankirti Muppalla

USF Tampa Graduate Theses and Dissertations

Cavitands are very important class of compounds in supramolecular chemistry. These molecules contain rigid enforced cavity,and have attracted considerable attention in supramolecular chemistry as building blocks for the construction of carcerands, hemicarcerands, and other host guests complexes. Nearly 40 years ago, Niederl and Vogel laid foundation for the study of such type of condensation reactions. In our laboratory we are involved in synthesis of resorcinarenes with readily available substrates such as resorcinol and aldehydes to form a cyclic tetramer.

Herein, I present detailed studies about the functionalization of the synthesized tetramers and their antimicrobial activity. Octahydroxy resorcinarenes were synthesized and …


A Leveled Examination Of Test-Driven Development Acceptance, David S. Janzen, Hossein Saiedian May 2007

A Leveled Examination Of Test-Driven Development Acceptance, David S. Janzen, Hossein Saiedian

Computer Science and Software Engineering

Test-driven development (TDD) has garnered considerable attention in professional settings and has made some inroads into software engineering and computer science education. A series of leveled experiments were conducted with students in beginning undergraduate programming courses through upper-level undergraduate, graduate, and professional training courses. This paper reports that mature programmers who try TDD are more likely to choose TDD over a similar test-last approach. Additionally this research reveals differences in programmer acceptance of TDD between beginning programmers who were reluctant to adopt TDD and more mature programmers who were more willing to adopt TDD. Attention is given to confounding factors, …


Make The Most Of Your Time: How Should The Analyst Work With Automated Traceability Tools?, Alex Dekhtyar, Jane Huffman Hayes, Jody Larsen May 2007

Make The Most Of Your Time: How Should The Analyst Work With Automated Traceability Tools?, Alex Dekhtyar, Jane Huffman Hayes, Jody Larsen

Computer Science and Software Engineering

Several recent studies employed traditional information retrieval (IR) methods to assist in the mapping of elements of software engineering artifacts to each other. This activity is referred to as candidate link generation because the final say in determining the final mapping belongs to the human analyst. Feedback techniques that utilize information from the analyst (on whether the candidate links are correct or not) have been shown to improve the quality of the mappings. Yet the analyst is making an investment of time in providing the feedback. This leads to the question of whether or not guidance can be provided to …


Gemini Mid-Ir Polarimetry Of Ngc 1068: Polarized Structures Around The Nucleus, C. Packham, S. Young, S. Fisher, K. Volk, R. Mason, J. H. Hough, P. F. Roche, Moshe Elitzur, J. Radomski, E. Perlman May 2007

Gemini Mid-Ir Polarimetry Of Ngc 1068: Polarized Structures Around The Nucleus, C. Packham, S. Young, S. Fisher, K. Volk, R. Mason, J. H. Hough, P. F. Roche, Moshe Elitzur, J. Radomski, E. Perlman

Physics and Astronomy Faculty Publications

We present diffraction-limited, 10 μm imaging polarimetry data for the central regions of the archetypal Seyfert active galactic nucleus NGC 1068. The position angle of polarization is consistent with three dominant polarizing mechanisms. We identify three distinct regions of polarization: (1) north of the nucleus, arising from aligned dust in the narrow emission line region, (2) south, east, and west of the nucleus, consistent with dust being channeled toward the central engine, and (3) a central minimum of polarization consistent with a compact (≤22 pc) torus. These observations provide continuity between the geometrically and optically thick torus and the …


Utilizing A Multi-Technique, Multi-Taxa Approach To Monitoring Wildlife Passageways On The Bennington Bypass In Southern Vermont, Mark A. Bellis, Scott D. Jackson, Curtis R. Griffin, Paige S. Warren, Alan O. Thompson May 2007

Utilizing A Multi-Technique, Multi-Taxa Approach To Monitoring Wildlife Passageways On The Bennington Bypass In Southern Vermont, Mark A. Bellis, Scott D. Jackson, Curtis R. Griffin, Paige S. Warren, Alan O. Thompson

Scott D. Jackson

Roadways affect wildlife habitat disproportionate to the area of land they occupy while impacting wildlife directly through direct loss of habitat, road mortality and disruption of movement. Roadways indirectly impact wildlife by isolating populations and disrupting gene flow and metapopulation dynamics. A variety of strategies have been used with mixed success to mitigate the impacts of transportation systems on wildlife. Underpasses are commonly used to facilitate movement of wildlife across roadways in Europe, Australia, Canada and the U.S. Through 2005, 460 terrestrial and 300 aquatic crossing structures have been identified throughout the United States but only a small portion of …


An Investigation Into The Effects Of Luminosity On The Mid-Infrared Spectral Energy Distributions Of Radio-Quiet Quasars, S. C. Gallagher, G. T. Richards, M. Lacy, D. C. Hines, Moshe Elitzur, L. J. Storrie-Lombardi May 2007

An Investigation Into The Effects Of Luminosity On The Mid-Infrared Spectral Energy Distributions Of Radio-Quiet Quasars, S. C. Gallagher, G. T. Richards, M. Lacy, D. C. Hines, Moshe Elitzur, L. J. Storrie-Lombardi

Physics and Astronomy Faculty Publications

We present an analysis of the effects of luminosity on the shape of the mid-infrared spectral energy distributions (SEDs) of 234 radio-quiet quasars originally presented by Richards et al. In quasars without evident dust extinction, the spectrally integrated optical and infrared luminosities are linearly correlated over nearly three decades in luminosity. We find a significant (≳99.99\% confidence) correlation between the 1.8-8.0 μm spectral index and infrared luminosity that indicates an enhancement of the mid-infrared continuum with increasing luminosity. Coupled with strong evidence for spectral curvature in more luminous quasars, we conclude that this trend is likely a manifestation of …


Gemini Mid-Ir Polarimetry Of Ngc 1068: Polarized Structures Around The Nucleus, Christopher C. Packham, Stuart Young, Scott E. Fisher, Kevin M. Volk, Rachel E. Mason, James H. Hough, Patrick F. Roche, Moshe Elitzur, James T. Radomski, Eric S. Perlman May 2007

Gemini Mid-Ir Polarimetry Of Ngc 1068: Polarized Structures Around The Nucleus, Christopher C. Packham, Stuart Young, Scott E. Fisher, Kevin M. Volk, Rachel E. Mason, James H. Hough, Patrick F. Roche, Moshe Elitzur, James T. Radomski, Eric S. Perlman

Aerospace, Physics, and Space Science Faculty Publications

We present diffraction-limited, 10 μm imaging polarimetry data for the central regions of the archetypal Seyfert active galactic nucleus NGC 1068. The position angle of polarization is consistent with three dominant polarizing mechanisms. We identify three distinct regions of polarization: (1) north of the nucleus, arising from aligned dust in the narrow emission line region, (2) south, east, and west of the nucleus, consistent with dust being channeled toward the central engine, and (3) a central minimum of polarization consistent with a compact (≤22 pc) torus. These observations provide continuity between the geometrically and optically thick torus and the host …


Depleted Carbon Monoxide In Fragment C Of The Jupiter-Family Comet 73p/Schwassmann-Wachmann 3, M. Disanti, W. Anderson, G. Villanueva, B. Bonev, K. Magee-Sauer, E. Gibb, M. Mumma May 2007

Depleted Carbon Monoxide In Fragment C Of The Jupiter-Family Comet 73p/Schwassmann-Wachmann 3, M. Disanti, W. Anderson, G. Villanueva, B. Bonev, K. Magee-Sauer, E. Gibb, M. Mumma

Physics Faculty Works

Carbon monoxide emission was targeted in fragment C of the recently split Jupiter-family comet 73P/Schwassmann-Wachmann 3 during its 2006 apparition, using the Cryogenic Echelle Spectrograph (CSHELL) at the NASA IRTF on Mauna Kea, Hawaii. Simultaneous sounding with H2O near 4.65 μm revealed highly depleted CO, consistent with a mixing ratio of 0.5% ± 0.13%. Along with depleted CH3OH but nearly normal HCN, this may indicate that this comet formed in the inner giant planets' region or, alternatively, that it formed relatively late, after significant clearing of the protosolar nebula.