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Faculty Publications

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Articles 3391 - 3420 of 4091

Full-Text Articles in Physical Sciences and Mathematics

Interface Relaxation In Electrophoretic Deposition Of Polymer Chains: Effects Of Segmental Dynamics, Molecular Weight, And Field, Frank W. Bentrem, Jun Xie, Ras B. Pandey Apr 2002

Interface Relaxation In Electrophoretic Deposition Of Polymer Chains: Effects Of Segmental Dynamics, Molecular Weight, And Field, Frank W. Bentrem, Jun Xie, Ras B. Pandey

Faculty Publications

Using different segmental dynamics and relaxation, characteristics of the interface growth is examined in an electrophoretic deposition of polymer chains on a three (2+1)-dimensional discrete lattice with a Monte Carlo simulation. Incorporation of faster modes such as crankshaft and reptation movements along with the relatively slow kink-jump dynamics seems crucial in relaxing the interface width. As the continuously released polymer chains are driven (via segmental movements) and deposited, the interface width W grows with the number of time steps t, W∝tβ, (β ~0.4-0.8), which is followed by its saturation to a steady-state value Ws …

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Anomalous Conductance Distribution In Quasi-One-Dimensional Gold Wires: Possible Violation Of The One-Parameter Scaling Hypothesis, Pritiraj Mohanty, Richard A. Webb Mar 2002

Anomalous Conductance Distribution In Quasi-One-Dimensional Gold Wires: Possible Violation Of The One-Parameter Scaling Hypothesis, Pritiraj Mohanty, Richard A. Webb

Faculty Publications

We report measurements of conductance distribution in a set of quasi-one-dimensional gold wires. The distribution includes the second cumulant or the variance which describes the universal conductance fluctuations, and the third cumulant which denotes the leading deviation. We have observed an asymmetric contribution—or, a nonvanishing third cumulant—contrary to the expectation for quasi-one-dimensional systems in the noninteracting theories in the one-parameter scaling framework, which include the perturbative diagrammatic calculations and the random matrix theory.

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Rapid Heterogeneous Ad Hoc Connection Establishment: Accelerating Bluetooth Inquiry Using Irda, Trevor Clifton, Derek D. Joos, Charles D. Knutson, Ryan W. Woodings Mar 2002

Rapid Heterogeneous Ad Hoc Connection Establishment: Accelerating Bluetooth Inquiry Using Irda, Trevor Clifton, Derek D. Joos, Charles D. Knutson, Ryan W. Woodings

Faculty Publications

Bluetooth device discovery is a time-intensive phase of the Bluetooth connection-establishment procedure. In this paper we propose a technique that integrates existing IrDA technology with Bluetooth technology to improve the ad hoc connection establishment time of Bluetooth devices. We accomplish this improvement by first establishing an IrDA connection between two devices equipped with both Bluetooth and IrDA capabilities and then exchanging Bluetooth device discovery information via the established IrDA connection. As a result of this cooperative exchange, the devices are able to bypass the time-intensive Bluetooth device discovery procedure. Our research shows that IrDA-assisted Bluetooth connection establishment is up to …

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The Effect Of Reactor Geometry On Frontal Polymerization Spin Modes, John A. Pojman, Jonathan Masere, Enrico Petretto, Mauro Rustici, Do-Sung Huh, Min Suk Kim, Vladimir Volpert Mar 2002

The Effect Of Reactor Geometry On Frontal Polymerization Spin Modes, John A. Pojman, Jonathan Masere, Enrico Petretto, Mauro Rustici, Do-Sung Huh, Min Suk Kim, Vladimir Volpert

Faculty Publications

Using reactors of different sizes and geometries the dynamics of the frontal polymerization of 1,6-hexanediol diacrylate (HDDA) and pentaerythritol tetraacrylate (PETAC), with ammonium persulfate as the initiator were studied. For this system, the frontal polymerization exhibits complex behavior that depends on the ratio of the monomers. For a particular range of monomers concentration, the polymerization front becomes nonplanar, and spin modes appear. By varying the reactor diameter, we experimentally confirmed the expected shift of the system to a greater number of "hot spots" for larger diameters. For square test tubes a "zig-zag" mode was observed for the first time in …

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Pattern Classification Using A Quantum System, Dan A. Ventura Mar 2002

Pattern Classification Using A Quantum System, Dan A. Ventura

Faculty Publications

We consider and compare three approaches to quantum pattern classification, presenting empirical results from simulations.

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Dijet Production In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli Mar 2002

Dijet Production In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli

Faculty Publications

Dijet cross sections in neutral current deep inelastic ep scattering have been measured in the range 10 < Q2 < 104 GeV 2 with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb-1. The cross sections, measured in the Breit frame using the kT jet algorithm, are compared with next-to-leading-order perturbative QCD calculations using proton parton distribution functions. The uncertainties of the QCD calculations have been studied. The predictions are in reasonable agreement with the measured cross sections over the entire kinematic range.

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Collisional Dynamics Of Bi2 A(0U+). Ii. State-To-State Rotational Energy Transfer, Robert E. Franklin, Glen P. Perram Mar 2002

Collisional Dynamics Of Bi2 A(0U+). Ii. State-To-State Rotational Energy Transfer, Robert E. Franklin, Glen P. Perram

Faculty Publications

Rotational-to-translational (R–T) energy transfer within v′=1 of the A(0+u) state of Bi2 has been investigated using spectrally resolved, laser induced fluorescence techniques. Spectrally resolved emissions from collisionally populated rotational levels of Bi2(A,v′=1) were observed for helium, neon, and argon collision partners after laser excitation of the high rotational levels J′=171, 201, and 231. Total rotational removal rates from the initially prepared state range from 2.8–8.9×10−10 cm3/molecule s. Collisional population of rotational states with |ΔJ|⩽56 was observed at pressures of 0.09–1.4 Torr. The state-to-state rates are adequately modeled by the energy based statistical power gap …

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Negative Band Gap Bowing In Epitaxial Inas/Gaas Alloys And Predicted Band Offsets Of The Strained Binaries And Alloys On Various Substrates, Gus L. W. Hart, Kwiseon Kim, Alex Zunger Feb 2002

Negative Band Gap Bowing In Epitaxial Inas/Gaas Alloys And Predicted Band Offsets Of The Strained Binaries And Alloys On Various Substrates, Gus L. W. Hart, Kwiseon Kim, Alex Zunger

Faculty Publications

We use pseudopotential theory to provide (1) the band offsets of strained GaAs and InAs on various substrates and (2) the energies Ev(x) of the valence and conduction bands of InxGa1-xAs alloy, as a function of composition. Results are presented for both the bulk alloy and for the alloy strained on InP or GaAs. We predict that while Ex(x) bows downward for relaxed bulk alloys, it bows upward for strained epitaxial alloys. The calculated alloy offsets are used to discuss electron and hole localization in this system.

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A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification Of Proteins By Scavenging Carbonyl Intermediates Of Carbohydrate And Lipid Degradation, Paul A. Voziyan, Thomas O. Metz, John W. Baynes, Billy G. Hudson Feb 2002

A Post-Amadori Inhibitor Pyridoxamine Also Inhibits Chemical Modification Of Proteins By Scavenging Carbonyl Intermediates Of Carbohydrate And Lipid Degradation, Paul A. Voziyan, Thomas O. Metz, John W. Baynes, Billy G. Hudson

Faculty Publications

Reactive carbonyl compounds are formed during autoxidation of carbohydrates and peroxidation of lipids. These compounds are intermediates in the formation of advanced glycation end products (AGE) and advanced lipoxidation end products (ALE) in tissue proteins during aging and in chronic disease. We studied the reaction of carbonyl compounds glyoxal (GO) and glycolaldehyde (GLA) with pyridoxamine (PM), a potent post-Amadori inhibitor of AGE formation in vitro and of development of renal and retinal pathology in diabetic animals. PM reacted rapidly with GO and GLA in neutral, aqueous buffer, forming a Schiff base intermediate that cyclized to a hemiaminal adduct by intramolecular …

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The Planetary Nebula Spectrograph: The Green Light For Galaxy Kinematics, N. G. Douglas, M. Arnaboldi, K. C. Freeman, K. Kuijken, M. R. Merrifield, Aaron J. Romanowsky, K. Taylor, M. Capaccioli, T. Axelrod, R. Gilmozzi, J. Hart, G. Bloxham, D. Jones Jan 2002

The Planetary Nebula Spectrograph: The Green Light For Galaxy Kinematics, N. G. Douglas, M. Arnaboldi, K. C. Freeman, K. Kuijken, M. R. Merrifield, Aaron J. Romanowsky, K. Taylor, M. Capaccioli, T. Axelrod, R. Gilmozzi, J. Hart, G. Bloxham, D. Jones

Faculty Publications

Planetary nebulae (PNe) are now well established as probes of galaxy dynamics and as standard candles in distance determinations. Motivated by the need to improve the efficiency of planetary nebulae searches and the speed with which their radial velocities are determined, a dedicated instrument—the Planetary Nebula Spectrograph, or PN.S—has been designed and commissioned at the 4.2 m William Herschel Telescope. The high optical efficiency of the spectrograph results in the detection of typically ∼150 PNe in galaxies at the distance of the Virgo Cluster in one night of observations. In the same observation, the radial velocities are obtained with an …

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Decomposition Of Pascal’S Kernels Mod PS, Richard P. Kubelka Jan 2002

Decomposition Of Pascal’S Kernels Mod PS, Richard P. Kubelka

Faculty Publications

For a prime p we define Pascal's Kernel K(p,s) = [k(p,s)ij]∞i,j=0 as the infinite matrix satisfying k(p,s)ij = 1/px(i+jj) mod p if (i+jj) is divisible by ps and k(p,s)ij = 0 otherwise. While the individual entries of Pascal's Kernel can be computed using a formula of Kazandzidis that has been known for some time, our purpose here will be to use that formula …

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Comment On ‘‘Stress-Density Ratio Slip-Corrected Reynolds Equation For Ultra-Thin Film Gas Bearing Lubrication’’, Alejandro Garcia Jan 2002

Comment On ‘‘Stress-Density Ratio Slip-Corrected Reynolds Equation For Ultra-Thin Film Gas Bearing Lubrication’’, Alejandro Garcia

Faculty Publications

No abstract provided.

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Recent Applications Of Flame Atomic Absorption Spectrometry To Environmental Measurements, Michael A. Janusa Jan 2002

Recent Applications Of Flame Atomic Absorption Spectrometry To Environmental Measurements, Michael A. Janusa

Faculty Publications

Atomic absorption spectroscopy is very useful for the determination of a large number of elements, especially at trace levels. It is a widely used technique for analysis of a wide variety of sample matrices including biota, soils, and water. Atomic absorption spectroscopy is a very reputable technique that is inexpensive and delivers accurate results even in a complex matrix. This review focuses on the applications of flame atomic absorption spectroscopy to environmental measurements, and is mainly based on papers published from 1999–2002.

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Soil Leachate Responses During 10 Years Of Induced Whole-Watershed Acidification, Pamela J. Edwards, James N. Kochenderfer, Dean W. Coble, Mary Beth Adams Jan 2002

Soil Leachate Responses During 10 Years Of Induced Whole-Watershed Acidification, Pamela J. Edwards, James N. Kochenderfer, Dean W. Coble, Mary Beth Adams

Faculty Publications

Soil solution was collected from zero-tension lysimeters for 10 yr on two small central Appalachian watersheds in West Virginia, U.S.A. Ammonium sulfate fertilizer was applied to one catchment 3 times per year during each year. The other watershed was used as a reference to account for ambient baseline conditions. Ca and Mg concentrations collected below the A- and B-horizons of the treated watershed increased and then decreased over time as a result of the treatment. By contrast, Ca and Mg concentrations in the C-horizon continued to increase throughout the study period.

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Effect Of Ga Content On Defect States In Cuin1-XGaXSe2 Photovoltaic Devices, Jennifer T. Heath, J. David Cohen, William N. Shafarman, Dongxiang Liao, Angus Rockett Jan 2002

Effect Of Ga Content On Defect States In Cuin1-XGaXSe2 Photovoltaic Devices, Jennifer T. Heath, J. David Cohen, William N. Shafarman, Dongxiang Liao, Angus Rockett

Faculty Publications

Defects in the band gap of CuIn1-xGaxSe2 have been characterized using transient photocapacitance spectroscopy. The measured spectra clearly show response from a band of defects centered around 0.8 eV from the valence band edge as well as an exponential distribution of band tail states. Despite Ga contents ranging from Ga/(In+Ga)=0.0 to 0.8, the defect bandwidth and its position relative to the valence band remain constant. This defect band may act as an important recombination center, contributing to the decrease in device efficiency with increasing Ga content.

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Pair Attribute Learning: Network Construction Using Pair Features, Tony R. Martinez, Eric K. Henderson Jan 2002

Pair Attribute Learning: Network Construction Using Pair Features, Tony R. Martinez, Eric K. Henderson

Faculty Publications

We present the Pair Attribute Learning (PAL) algorithm for the selection of relevant inputs and network topology. Correlations on training instance pairs are used to drive network construction of a single-hidden layer MLP. Results on nine learning problems demonstrate 70% less complexity, on average, without a significant loss of accuracy.

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The Algebra And Geometry Of Curve And Surface Inversion, Thomas W. Sederberg, Eng-Wee Chionh, Kent Ridge Jan 2002

The Algebra And Geometry Of Curve And Surface Inversion, Thomas W. Sederberg, Eng-Wee Chionh, Kent Ridge

Faculty Publications

An inversion equation takes the Cartesian coordinates of a point on a parametric curve or surface and returns the parameter value(s) of that point. A 2-D curve inversion equation has the form t = f(x,y)/g(x,y). This paper shows that practical insight into inversion can be obtained by studying the geometry of the implicit curves f(x,y) = 0 and g(x,y) = 0. For example, the relationship between the singular locus of the parametric curve and the lowest possible degree of an inversion equation can be understood in this way. Also, insight is given into what parameter value will be returned if …

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Measurement Of The Q2 And Energy Dependence Of Diffractive Dnteractions At Hera: The Zeus Collaboration, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Anzivino, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari Jan 2002

Measurement Of The Q2 And Energy Dependence Of Diffractive Dnteractions At Hera: The Zeus Collaboration, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Anzivino, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, M. Chiarini, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, C. Nemoz, F. Palmonari

Faculty Publications

Diffractive dissociation of virtual photons, γ*p → Xp, has been studied in ep interactions with the ZEUS detector at HERA. The data cover photon virtualities 0.17 < Q2 < 0.70 GeV2 and 3 < Q2 < 80 GeV2 with 3 < MX < 38 GeV, where MX is the mass of the hadronic final state. Diffractive events were selected by two methods: the first required the detection of the scattered proton in the ZEUS leading proton spectrometer (LPS); the second was based on the distribution of MX. The integrated luminosities of the low- and high-Q2 samples used in the LPS-based analysis are ≃ 0.9 pb-1 and ≃ 3.3 pb-1, respectively. The sample used for the MX-based analysis corresponds to an integrated luminosity of ≃ 6.2 pb-1. The dependence of the diffractive cross section on W, the virtual photon-proton centre-of-mass energy, and on Q2 is studied. In the low-Q2 range, the energy dependence is compatible with Regge theory and is used to determine the intercept of the Pomeron trajectory. The W dependence of the diffractive cross section exhibits no significant change from the low-Q2 to the high-Q2 region. In the low-Q2 range, little Q2 dependence is found, a significantly different behaviour from the rapidly falling cross section measured for Q2 > 3 GeV2. The ratio of the diffractive to the virtual photon-proton total cross section is studied as a function of W and Q2. Comparisons are made with a model based on perturbative QCD.

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A Sufficient Condition For The Uniqueness Of Positive Steady State To A Reaction Diffusion System, Joon Hyuk Kang, Yun Oh Jan 2002

A Sufficient Condition For The Uniqueness Of Positive Steady State To A Reaction Diffusion System, Joon Hyuk Kang, Yun Oh

Faculty Publications

In this paper, we concentrate on the uniqueness of the positive solution for the general elliptic system { Δu + u(g1(u) - g 2(v)) = 0 in R+ × Ω, Δν + v(h 1(u) - h2(v)) = 0 u|∂Ω = v| ∂Ω = 0. This system is the general model for the steady state of a competitive interacting system. The techniques used in this paper are upper-lower solutions, maximum principles and spectrum estimates. The arguments also rely on some detailed properties for the solution of logistic equations.

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Crustal Fissuring On The Crest Of The Southern East Pacific Rise At 17˚15'-40'S, Dawn J. Wright, Rachel M. Haymon, Scott M. White, Ken C. Macdonald Jan 2002

Crustal Fissuring On The Crest Of The Southern East Pacific Rise At 17˚15'-40'S, Dawn J. Wright, Rachel M. Haymon, Scott M. White, Ken C. Macdonald

Faculty Publications

Fissure densities and widths have been mapped along the axial zone of the superfast spreading southern East Pacific Rise (EPR) at 17_150–400S with the near-bottom DSL-120 and Argo II imaging systems. We observe that the youngest lava flows (on a relative age scale) are sparsely fissured and that there is a cumulative increase in fissure abundance with time that produces a strong positive correlation between fissure density and relative age of lava flows. Average fissure widths were used to estimate fissure depths. In the 17_150–400S area, calculated fissure depths are estimated to extend below the seismic layer 2A/2B boundary, and …

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Role Of A Phase: Change Moho In Stabilization And Preservation Of The Southern Uralide Orogen, Russia, Camelia C. Diaconescu, James H. Knapp Jan 2002

Role Of A Phase: Change Moho In Stabilization And Preservation Of The Southern Uralide Orogen, Russia, Camelia C. Diaconescu, James H. Knapp

Faculty Publications

Geophysical (URSEIS experiment) and geological data from the Southern Uralides of central Russia provide the basis for a geodynamic model involving eclogitization of the Uralian crustal root in Late Triassic to Early Jurassic time as a mechanism for stabilization and preservation of this Paleozoic orogen. The crustal structure of the orogen implies eastward subduction of the East European continental crust, and balanced restoration implies a significant volume of crust (comprised of ~70% European crust, and ~30% accreted terranes) was carried to sub-Moho depths of up to 70 km. The lack of a clearly defined near-vertical incidence reflection Moho corroborated by …

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A New Occurrence Of Archaeoscyphia Pulchra (Bassler) From The Ordovician Of Western Canada, J. Keith Rigby, Godfrey S. Nowlan, Peter A. Rowlands Jan 2002

A New Occurrence Of Archaeoscyphia Pulchra (Bassler) From The Ordovician Of Western Canada, J. Keith Rigby, Godfrey S. Nowlan, Peter A. Rowlands

Faculty Publications

A few specimens of the ornate anthaspidellid demosponge, Archaeoscyphia pulchra (Bassler), have been collected from the Lower Ordovician Outram Formation or Skoki Formation, from a saddle at the head of South Rice Brook in northeastern British Columbia. This is the first report of the flanged-appearing annulate, steeply obconical sponge in western Canada, although it has been reported from the Mingan Islands of Quebec and was initially described from Nevada, in the western United States. The taxon has also been reported as other species of Archaeoscyphia from Ordovician rocks of Missouri and from the San Juan region of Argentina.

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Peppering Knowledge Sources With Salt: Boosting Conceptual Content For Ontology Generation, Deryle W. Lonsdale, Yihong Ding, David W. Embley, Alan Melby Jan 2002

Peppering Knowledge Sources With Salt: Boosting Conceptual Content For Ontology Generation, Deryle W. Lonsdale, Yihong Ding, David W. Embley, Alan Melby

Faculty Publications

This paper describes work done to explore the common ground between two different ongoing research projects: the standardization of lexical and terminological resources, and the use of conceptual ontologies for information extraction and data integration. Specifically, this paper explores improving the generation of extraction ontologies through use of a comprehensive terminology database that has been represented in a standardized format for easy tool-based implementation. We show how, via the successful integration of these two distinct efforts, it is possible to leverage large-scale terminological and conceptual information having relationship-rich semantic resources in order to reformulate, match, and merge retrieved information of …

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“[Cu(Pyrazine-2-Carboxylate)2]2Cd4I8: Unprecedented 1-D Serpentine Chains And Regular 2-D Regular Metal-Organic Square Grids In A 3-D Framework., Delia M. Ciurtin, Mark D. Smith, Hans Conrad Zur Loye Dec 2001

“[Cu(Pyrazine-2-Carboxylate)2]2Cd4I8: Unprecedented 1-D Serpentine Chains And Regular 2-D Regular Metal-Organic Square Grids In A 3-D Framework., Delia M. Ciurtin, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

A novel three-dimensional coordination polymer containing
an unprecedented one-dimensional serpentine motif conjoined
with a two-dimensional square grid motif is presented.

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Development Of Cfl-Free, Explicit Schemes For Multidimensional Advection-Reaction Equations, Hong Wang, Jiangguo Liu Dec 2001

Development Of Cfl-Free, Explicit Schemes For Multidimensional Advection-Reaction Equations, Hong Wang, Jiangguo Liu

Faculty Publications

We combine an Eulerian–Lagrangian approach and multiresolution analysis to develop unconditionally stable, explicit, multilevel methods for multidimensional linear hyperbolic equations. The derived schemes generate accurate numerical solutions even if large time steps are used. Furthermore, these schemes have the capability of carrying out adaptive compression without introducing mass balance error. Computational results are presented to show the strong potential of the numerical methods developed.

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Origins Of Nonstoichiometry And Vacancy Ordering In Sc1-X□Xs, Gus L. W. Hart, Alex Zunger Dec 2001

Origins Of Nonstoichiometry And Vacancy Ordering In Sc1-X□Xs, Gus L. W. Hart, Alex Zunger

Faculty Publications

Whereas nearly all compounds AnBm obey Dalton's rule of integer stoichiometry (n:m, both integer), there is a class of systems, exemplified by the rocksalt structure Sc1-x□xS, that exhibits large deviations from stoichiometry via vacancies, even at low temperatures. By combining first-principles total energy calculations with lattice statistical mechanics, we scan an astronomical number of possible structures, identifying the stable ground states. Surprisingly, all have the same motifs: (111) planes with (112) vacancy rows arranged in (110) columns. Electronic structure calculations of the ground states (identified out of ~3 × 10^6 structures) reveal the remarkable origins of nonstoichiometry.

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Three Unique Coordination Geometries Involving 1,2-Dimethoxy-4,5-Bis(2-Pyridylethynyl)Benzene, Jeffrey E. Fiscus, Sandra Shotwell, Ralph C. Layland, Mark D. Smith, Hans Conrad Zur Loye, Uwe H. F. Bunz Dec 2001

Three Unique Coordination Geometries Involving 1,2-Dimethoxy-4,5-Bis(2-Pyridylethynyl)Benzene, Jeffrey E. Fiscus, Sandra Shotwell, Ralph C. Layland, Mark D. Smith, Hans Conrad Zur Loye, Uwe H. F. Bunz

Faculty Publications

Reaction of the new ligand 1,2-dimethoxy-4,5-bis(2-pyridylethynyl) benzene with different metal centers under similar reaction conditions led to three distinct structure formation processes: molecular ring closure, dimerization, and polymer formation.

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Image Magnification Using Level-Set Reconstruction, Bryan S. Morse, Duane Schwartzwald Dec 2001

Image Magnification Using Level-Set Reconstruction, Bryan S. Morse, Duane Schwartzwald

Faculty Publications

Image magnification is a common problem in imaging applications, requiring interpolation to “read between the pixels”. Although many magnification/interpolation algorithms have been proposed in the literature, all methods must suffer to some degree the effects of impefect reconstruction―false high-frequency content introduced by the underlying original sampling. Most often, these effects manifest themselves as jagged contours in the image. This paper presents a method for constrained smoothing of such artifacts that attempts to produce smooth reconstructions of the image’s level curves while still maintaining image fidelity. This is similar to other iterative reconstruction algorithms and to Bayesian restoration techniques, but instead …

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Houghing The Hough: Peak Collection For Detection Of Corners, Junctions And Line Intersections, William A. Barrett, Kevin D. Petersen Dec 2001

Houghing The Hough: Peak Collection For Detection Of Corners, Junctions And Line Intersections, William A. Barrett, Kevin D. Petersen

Faculty Publications

We exploit the Accumulator Array of the Hough Transform by finding collections of (2 or more) peaks through which a given sinusoid will pass. Such sinusoids identify points in the original image where lines intersect. Peak collection (or line aggregation) is performed by making a second pass through the edge map, but instead of laying points down in the accumulator array (as with the original Hough Transform), we compute the line integral over each sinusoid that corresponds to the current edge point. If a sinusoid passes through greater than or equal to 2 peaks, we deposit that sum/integral into a …

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A Confidence Measure For Boundary Detection And Object Selection, William A. Barrett, Eric N. Mortensen Dec 2001

A Confidence Measure For Boundary Detection And Object Selection, William A. Barrett, Eric N. Mortensen

Faculty Publications

We introduce a confidence measure that estimates the assurance that a graph arc (or edge) corresponds to an object boundary in an image. A weighted, planar graph is imposed onto the watershed lines of a gradient magnitude image and the confidence measure is a function of the cost of fixed-length paths emanating from and extending to each end of a graph arc. The confidence measure is applied to automate the detection of object boundaries and thereby reduces (often greatly) the time and effort required for object boundary definition within a user-guided image segmentation environment.

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