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Sample records for surface vanadia overlayer

  1. Dispersion state and catalytic properties of vanadia species on the surface of V2O5/TiO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    许波连; 陈懿; 范以宁; 刘浏; 林明

    2002-01-01

    The dispersion state and catalytic properties of anatase-supported vanadia species are studied by means of X-ray diffraction (XRD), laser Raman spectroscopy (LRS), H2 temperature-programmed reduction (TPR) and the selective oxidation of o-xylene to phthalic anhydride. The almost identical values of the experimental dispersion capacity of V2O5 on anatase and the surface vacant sites available on the preferentially exposed (001) plane of anatase suggest that the highly dispersed vanadium cations are bonded to the vacant sites on the surface of anatase as derived by the incorporation model. When the loading amount of V2O5 is far below its dispersion capacity, the dispersed vanadia species might mainly consist of isolated VOx species bridging to the surface through V-O-Ti bonds. With the increase of V2O5 loading the isolated vanadia species interact with their nearest neighbors (either isolated or polymerized vanadia) through bridging V-O-V at the expenses of V-O-Ti bonds, resulting in the increase of the ra

  2. Dispersion state and catalytic properties of vanadia species on the surface of V2O5/TiO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    许波连; 范以宁; 刘浏; 林明; 陈懿

    2002-01-01

    The dispersion state and catalytic properties of anatase-supported vanadia species are studied by means of X-ray diffraction (XRD), laser Raman spectroscopy (LRS), H2 temperature-programmed reduction (TPR) and the selective oxidation of o-xylene to phthalic anhydride. The almost identical values of the experimental dispersion capacity of V2O5 on anatase and the surface vacant sites available on the preferentially exposed (001) plane of anatase suggest that the highly dispersed vanadium cations are bonded to the vacant sites on the surface of anatase as derived by the incorporation model. When the loading amount of V2O5 is far below its dispersion capacity, the dispersed vanadia species might mainly consist of isolated VOx species bridging to the surface through V-O-Ti bonds. With the increase of V2O5 loading the isolated vanadia species interact with their nearest neighbors (either isolated or polymerized vanadia) through bridging V-O-V at the expenses of V-O-Ti bonds, resulting in the increase of the ratio of polymerized to isolated vanadia species and the decrease of the reactivity of the associated surface oxygen anions and, consequently, although the activity increases with loading to reach a maximum value, the turn over number (TON) of the V2O5/TiO2 catalyst decreases linearly. When the loading amount of V2O5 is higher than its dispersion capacity, the turn over number decreases more rapidly with the increase of V2O5 loading due to the formation of V2O5 crystallites in which the oxygen anions associated with V-O-V bonds are less reactive and only partially exposed on the surface.

  3. CO Chemisorption at Metal Surfaces and Overlayers

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Morikawa, Y.; Nørskov, Jens Kehlet

    1996-01-01

    A database of ab initio calculations of the chemisorption energy of CO over Ni(111), Cu(111), Ru(0001), Pd(111), Ag(111), Pt(111), Au(111), Cu3Pt(111), and some metallic overlayer structures is presented. The trends can be reproduced with a simple model describing the interaction between the meta...... d states and the CO 2 pi* and 5 sigma states, renormalized by the metal sp continuum. Our model rationalizes the results by Rodriguez and Goodman [Science 257, 897 (1992)] showing a strong correlation between the CO chemisorption energy and the surface core level shift.......A database of ab initio calculations of the chemisorption energy of CO over Ni(111), Cu(111), Ru(0001), Pd(111), Ag(111), Pt(111), Au(111), Cu3Pt(111), and some metallic overlayer structures is presented. The trends can be reproduced with a simple model describing the interaction between the metal...

  4. Nanocrystalline Anatase Titania Supported Vanadia Catalysts: Facet-dependent Structure of Vanadia

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei-Zhen; Gao, Feng; Li, Yan; Walter, Eric D.; Liu, Jun; Peden, Charles HF; Wang, Yong

    2015-07-09

    Titania supported vanadia, a classic heterogeneous catalyst for redox reactions, typically has nonhomogeneous vanadia species on various titania facets, making it challenging not only to determine and quantify each species but also to decouple their catalytic contributions. We prepared truncated tetragonal bipyramidal (TiO2-TTB) and rod-like (TiO2-Rod) anatase titania with only {101} and {001} facets at ratios of about 80:20 and 93:7, respectively, and used them as supports of sub-monolayer vanadia. The structure and redox properties of supported vanadia were determined by XRD, TEM, XPS, EPR, Raman, FTIR and TPR, etc. It was found that vanadia preferentially occupy TiO2 {001} facets and form isolated O=V4+(O-Ti)2 species, and with further increase in vanadia surface coverage, isolated O=V5+(O-Ti)3 and oligomerized O=V5+(O-M)3 (M = Ti or V) species form on TiO2 {101} facets. The discovery on support facet-dependent structure of vanadia on anatase titania is expected to enable the elucidation of structure-function correlations on high surface area TiO2 supported vanadia catalysts. This work was supported by U. S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences. The research was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research, and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for DOE by Battelle.

  5. Enhancing of catalytic properties of vanadia via surface doping with phosphorus using atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Strempel, Verena E.; Naumann d' Alnoncourt, Raoul, E-mail: r.naumann@bascat.tu-berlin.de [BasCat - UniCat BASF JointLab, Technische Universität Berlin, Sekr. EW K 01, Hardenbergstraße 36, 10623 Berlin (Germany); Löffler, Daniel [Process Research and Chemical Engineering, BASF SE, Carl-Bosch-Straße 38, 67056 Ludwigshafen (Germany); Kröhnert, Jutta; Skorupska, Katarzyna; Johnson, Benjamin [Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany); Driess, Matthias [BasCat - UniCat BASF JointLab, Technische Universität Berlin, Sekr. EW K 01, Hardenbergstraße 36, 10623 Berlin, Germany and Technische Universität Berlin, Institut für Chemie, Sekr. C2, Straße des 17. Juni 135, 10623 Berlin (Germany); Rosowski, Frank [BasCat - UniCat BASF JointLab, Technische Universität Berlin, Sekr. EW K 01, Hardenbergstraße 36, 10623 Berlin, Germany and Process Research and Chemical Engineering, BASF SE, Carl-Bosch-Straße 38, 67056 Ludwigshafen (Germany)

    2016-01-15

    Atomic layer deposition is mainly used to deposit thin films on flat substrates. Here, the authors deposit a submonolayer of phosphorus on V{sub 2}O{sub 5} in the form of catalyst powder. The goal is to prepare a model catalyst related to the vanadyl pyrophosphate catalyst (VO){sub 2}P{sub 2}O{sub 7} industrially used for the oxidation of n-butane to maleic anhydride. The oxidation state of vanadium in vanadyl pyrophosphate is 4+. In literature, it was shown that the surface of vanadyl pyrophosphate contains V{sup 5+} and is enriched in phosphorus under reaction conditions. On account of this, V{sub 2}O{sub 5} with the oxidation state of 5+ for vanadium partially covered with phosphorus can be regarded as a suitable model catalyst. The catalytic performance of the model catalyst prepared via atomic layer deposition was measured and compared to the performance of catalysts prepared via incipient wetness impregnation and the original V{sub 2}O{sub 5} substrate. It could be clearly shown that the dedicated deposition of phosphorus by atomic layer deposition enhances the catalytic performance of V{sub 2}O{sub 5} by suppression of total oxidation reactions, thereby increasing the selectivity to maleic anhydride.

  6. Vanadia supported on zeolites for SCR of NO by ammonia

    DEFF Research Database (Denmark)

    Putluru, Siva Sankar Reddy; Riisager, Anders; Fehrmann, Rasmus

    2010-01-01

    Vanadia supported on zeolites were prepared and characterized by N-2 physisorption, FTIR. XRPD, and NH3-TPD methods. The influence of the Si/Al ratio on the total surface acidity of the catalysts as well as the optimum V2O5 content were studied and compared with the catalytic activity in the sele......Vanadia supported on zeolites were prepared and characterized by N-2 physisorption, FTIR. XRPD, and NH3-TPD methods. The influence of the Si/Al ratio on the total surface acidity of the catalysts as well as the optimum V2O5 content were studied and compared with the catalytic activity......, acidity and micropore structure of the support. Apparently the support hosted the potassium oxide on the acid sites, thereby protecting the active vanadium species from poisoning. Zeolite based catalysts might therefore prove useful for SCR of NO in alkali-containing flue gases from, e.g. biomass fired...

  7. Effect of catalyst structure on oxidative dehydrogenation of ethane and propane on alumina-supported vanadia

    Energy Technology Data Exchange (ETDEWEB)

    Argyle, Morris D.; Chen, Kaidong; Bell, Alexis T.; Iglesia, Enrique

    2001-09-11

    The catalytic properties of Al2O3-supported vanadia with a wide range of VOx surface density (1.4-34.2 V/nm2) and structure were examined for the oxidative dehydrogenation of ethane and propane. UV-visible and Raman spectra showed that vanadia is dispersed predominantly as isolated monovanadate species below {approx}2.3 V/nm2. As surface densities increase, two-dimensional polyvanadates appear (2.3-7.0 V/nm2) along with increasing amounts of V2O5 crystallites at surface densities above 7.0 V/nm2. The rate constant for oxidative dehydrogenation (k1) and its ratio with alkane and alkene combustion (k2/k1 and k3/k1, respectively) were compared for both alkane reactants as a function of vanadia surface density. Propene formation rates (per V-atom) are {approx}8 times higher than ethene formation rates at a given reaction temperature, but the apparent ODH activation energies (E1) are similar for the two reactants and relatively insensitive to vanadia surface density. Ethene and propene formation rates (per V-atom) are strongly influenced by vanadia surface density and reach a maximum value at intermediate surface densities ({approx}8 V/nm2). The ratio of k2/k1 depends weakly on reaction temperature, indicating that activation energies for alkane combustion and ODH reactions are similar. The ratio of k2/k1 is independent of surface density for ethane, but increase slightly with vanadia surface density for propane, suggesting that isolated structures prevalent at low surface densities are slightly more selective for alkane dehydrogenation reactions. The ratio of k3/k1 decreases markedly with increasing reaction temperature for both ethane and propane ODH. Thus, the apparent activation energy for alkene combustion (E3) is much lower than that for alkane dehydrogenation (E1) and the difference between these two activation energies decreases with increasing surface density. The lower alkene selectivities observed at high vanadia surface densities are attributed to an

  8. High performance vanadia-anatase nanoparticle catalysts for the selective catalytic reduction of NO by ammonia

    DEFF Research Database (Denmark)

    Kristensen, Steffen Buus; Kunov-Kruse, Andreas Jonas; Riisager, Anders;

    2011-01-01

    Highly active nanoparticle SCR deNO(x) catalysts composed of amorphous vanadia on crystalline anatase have been prepared by a sol-gel, co-precipitation method using decomposable crystallization seeds. The catalysts were characterized by means of XRPD, TEM/SEM, FT-IR, nitrogen physisorption and NH(3......)-TPD. Due to the high-surface area anatase particles, loading of 20 wt% vanadia could be obtained without exceeding monolayer coverage of V(2)O(5). This resulted in unprecedented high deNO(x) SCR activity corresponding to a factor of two compared to an industrial reference and to other V(2)O(5)/TiO(2...

  9. Thermal stability of vanadia-tungsta-titania catalysts in the SCR process

    Energy Technology Data Exchange (ETDEWEB)

    Madia, G.; Elsener, M.; Koebel, M.; Raimondi, F.; Wokaun, A. [Paul Scherrer Institute, CH-5232 PSI Villigen (Switzerland)

    2002-11-28

    The thermal behaviour of TiO{sub 2}-WO{sub 3}-V{sub 2}O{sub 5} catalysts with various vanadia contents (1, 2 and 3wt.% V{sub 2}O{sub 5}) was investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and BET surface area determination. The activity and selectivity of the new and thermally treated catalysts were tested in the SCR reaction. Both structural and catalytic investigations have shown that the vanadia content has a strong effect on the thermal behaviour of the SCR catalysts. The structural investigations evidenced anatase sintering, increase of polymeric vanadyl surface species and three-dimensional growth of supported vanadia upon ageing. The catalytic tests have shown that the SCR activity of catalysts containing 1 or 2% V{sub 2}O{sub 5} increased upon ageing, whereas the SCR performance of the catalyst with 3% V{sub 2}O{sub 5} decreased. The observed improvement of the SCR performance is attributed to an increase of the amount of polymeric vanadyl surface species upon ageing. The decrease of the SCR performance of the catalyst with 3% V{sub 2}O{sub 5} is due to the extensive loss of surface area and to the three-dimensional growth of supported vanadia upon ageing. The catalyst containing 2% V{sub 2}O{sub 5} represents the best compromise between high SCR activity and good thermal stability.

  10. Impact of organic overlayers on a-Si:H/c-Si surface potential

    KAUST Repository

    Seif, Johannes P.

    2017-04-11

    Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.

  11. Structure of alumina supported vanadia catalysts for oxidative dehydrogenation of propane prepared by flame spray pyrolysis

    DEFF Research Database (Denmark)

    Høj, Martin; Jensen, Anker Degn; Grunwaldt, Jan-Dierk

    2013-01-01

    .%. The catalysts were subsequently characterized by BET surface area, X-ray diffraction (XRD), Raman, UV–vis diffuse reflectance and X-ray absorption spectroscopy (XAS) as well as measurement of the catalytic performance. The catalysts had specific surface areas from 143 to 169 m2/g corresponding to average.......1 VOx/nm2), a mixture of vanadia oligomers and monomers at 5wt.% V (3.6 VOx/nm2) and mainly oligomers at 7.5 and 10wt.% V (6.0 and 8.4 VOx/nm2). Diffuse reflectance UV–vis and extended X-ray absorption fine structure (EXAFS) spectroscopy measurements supported the results of Raman spectroscopy. In situ...... particles diameters from 9.0 to 10.9nm and apparent vanadia surface densities from 1.4 to 8.4 VOx/nm2. The only crystalline phase detected by XRD was γ-Al2O3, except at 10wt.% vanadium where traces of crystalline vanadia were observed. Raman spectroscopy showed vanadia monomers at 2 and 3wt.% V (1.4 and 2...

  12. Thickness effects of water overlayer on its explosive evaporation at heated metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Dou Yusheng E-mail: ysd@chem.psu.edu; Zhigilei, Leonid V.; Postawa, Zbigniew; Winograd, Nicholas; Garrison, Barbara J

    2001-06-01

    Molecular dynamics (MD) simulations have been employed to investigate the effect of the thickness of a water overlayer on the character of its ejection from a heated Au surface. The simulations are performed for five systems differing in the thickness of the water overlayer which was adsorbed on a metal substrate heated to 1000 K. For each system, an explosive evaporation occurs in the part of the water film adjacent to the metal surface and the upper part of the film is pushed off by the generated force. The average maximum temperature of the water film decreases as the film thickness increases. In contrast, the temperature achieved by the fast cooling due to the explosive evaporation shows an inverse trend. The significance of these model calculations to matrix-assisted laser desorption and ionization (MALDI) mass spectrometry is discussed.

  13. Vibrations of alkali metal overlayers on metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rusina, G G; Eremeev, S V; Borisova, S D [Institute of Strength Physics and Materials Science SB RAS, 634021, Tomsk (Russian Federation); Echenique, P M; Chulkov, E V [Donostia International Physics Center (DIPC), 20018 San Sebastian/Donostia, Basque Country (Spain); Benedek, G [Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy)], E-mail: rusina@ispms.tsc.ru

    2008-06-04

    We review the current progress in the understanding of vibrations of alkalis adsorbed on metal surfaces. The analysis of alkali vibrations was made on the basis of available theoretical and experimental results. We also include in this discussion our recent calculations of vibrations in K/Pt(111) and Li(Na)/Cu(001) systems. The dependence of alkali adlayer localized modes on atomic mass, adsorption position and coverage as well as the dependence of vertical vibration frequency on the substrate orientation is discussed. The square root of atomic mass dependence of the vertical vibration energy has been confirmed by using computational data for alkalis on the Al(111) and Cu(001) substrates. We have confirmed that in a wide range of submonolayer coverages the stretch mode energy remains nearly constant while the energy of in-plane polarized modes increases with the increase of alkali coverage. It was shown that the spectrum of both stretch and in-plane vibrations can be very sensitive to the adsorption position of alkali atoms and substrate orientation.

  14. Vibrations of alkali metal overlayers on metal surfaces

    Science.gov (United States)

    Rusina, G. G.; Eremeev, S. V.; Echenique, P. M.; Benedek, G.; Borisova, S. D.; Chulkov, E. V.

    2008-06-01

    We review the current progress in the understanding of vibrations of alkalis adsorbed on metal surfaces. The analysis of alkali vibrations was made on the basis of available theoretical and experimental results. We also include in this discussion our recent calculations of vibrations in K/Pt(111) and Li(Na)/Cu(001) systems. The dependence of alkali adlayer localized modes on atomic mass, adsorption position and coverage as well as the dependence of vertical vibration frequency on the substrate orientation is discussed. The square root of atomic mass dependence of the vertical vibration energy has been confirmed by using computational data for alkalis on the Al(111) and Cu(001) substrates. We have confirmed that in a wide range of submonolayer coverages the stretch mode energy remains nearly constant while the energy of in-plane polarized modes increases with the increase of alkali coverage. It was shown that the spectrum of both stretch and in-plane vibrations can be very sensitive to the adsorption position of alkali atoms and substrate orientation.

  15. Stability and catalytic performance of vanadia supported on nanostructured titania catalyst in oxidative dehydrogenation of propane

    Science.gov (United States)

    Kootenaei, A. H. Shahbazi; Towfighi, J.; Khodadadi, A.; Mortazavi, Y.

    2014-04-01

    Titanate nanotubes with a high specific surface area were synthesized by the simple hydrothermal method and investigated as support for V2O5 catalyst in oxidative dehydrogenation of propane (ODP). The structures of pristine nanotubes as well as the prepared catalysts were investigated by XRD, Raman, FTIR, HRTEM, SEM, EDS, BET, and XPS techniques. The characterization of the as-synthesized nanotubes showed the synthesis of hydrogen titanate nanotube. The incipient wetness impregnation method was utilized to prepare VTNT-x (x = 5, 10, and 15 wt.% vanadia supported on nanotube) together with VTi5 (5 wt.% vanadia supported on Degussa P25). The anatase phase was developed in VTNT-x catalysts upon calcination along with specific surface area loss. Higher vanadia loading resulted in the lowering of support capacity in maintaining vanadia in dispersed state such that eventually crystalline vanadia appeared. The measured catalyst activity demonstrates that in spite of major support surface area loss in VTNT-5 catalyst, the propylene yield is superior in comparison with VTi5 catalyst. The catalyst activity can be correlated with maximum reduction temperature. Deactivation of VTi5 and VTNT-5 as well as VTNT-15 were studied for 3,000 min time-on-stream. It was found that the activity of VTNT-5 catalyst remain unchanged while a decline in catalytic activity observed in VTi5 and VTNT-15 catalysts. The development of rutile was considered as being a major element in the deactivation of the investigated catalysts which is influenced by the presence of vanadium and reaction atmosphere.

  16. Passivating surface states on water splitting hematite photoanodes with alumina overlayers

    KAUST Repository

    Le Formal, Florian

    2011-01-24

    Hematite is a promising material for inexpensive solar energy conversion via water splitting but has been limited by the large overpotential (0.5-0.6 V) that must be applied to afford high water oxidation photocurrent. This has conventionally been addressed by coating it with a catalyst to increase the kinetics of the oxygen evolution reaction. However, surface recombination at trapping states is also thought to be an important factor for the overpotential, and herein we investigate a strategy to passivate trapping states using conformal overlayers applied by atomic layer deposition. While TiO2 overlayers show no beneficial effect, we find that an ultra-thin coating of Al2O3 reduces the overpotential required with state-of-the-art nano-structured photo-anodes by as much as 100 mV and increases the photocurrent by a factor of 3.5 (from 0.24 mA cm-2 to 0.85 mA cm-2) at +1.0 V vs. the reversible hydrogen electrode (RHE) under standard illumination conditions. The subsequent addition of Co2+ ions as a catalyst further decreases the overpotential and leads to a record photocurrent density at 0.9 V vs. RHE (0.42 mA cm-2). A detailed investigation into the effect of the Al2O3 overlayer by electrochemical impedance and photoluminescence spectroscopy reveals a significant change in the surface capacitance and radiative recombination, respectively, which distinguishes the observed overpotential reduction from a catalytic effect and confirms the passivation of surface states. Importantly, this work clearly demonstrates that two distinct loss processes are occurring on the surface of high-performance hematite and suggests a viable route to individually address them. © The Royal Society of Chemistry 2011.

  17. Electron coincidence studies of sulfur-overlayers on Cu(001) and Ni(001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Di Filippo, G., E-mail: gianluca.filippo@fau.de [Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany); Schumann, F.O.; Patil, S.; Wei, Z. [Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany); Stefani, G. [CNISM and Dipartimento di Scienze, Università Roma Tre, Via della Vasca Navale 84, 00146 Rome (Italy); Fratesi, G. [Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milan (Italy); Trioni, M.I. [CNR – National Research Council of Italy, ISTM, Via Golgi 19, 20133 Milan (Italy); Kirschner, J. [Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany)

    2016-08-15

    Highlights: • The LVV Auger decay of different sulfur-overlayers is investigated. • The decay can be described within a two-step model. • The Auger line shapes furnish information on the electronic structure at the surface. • The e–e correlation energy is hardly affected by coverage or substrate variations. - Abstract: We have prepared different sulfur-overlayers on Cu(001) and Ni(001) surfaces which differ in their coverage and local environment of the S adatoms. Via photon absorption we excited the S 2p level and studied the subsequent Auger decay with a coincidence spectrometer. We discuss the variation of the coincidence rate as a function of the energy sum of the photo-Auger electron pair. This is linked to the binding energy of the double-hole state. We find that the photon energy has no dramatic influence on the spectra. Differences are observed when the local environment of sulfur is changed. The observed spectral changes are mainly ascribable to the variation of the density of states at the different surfaces. On the contrary, the strength of electron–electron correlation at the surface states is hardly affected by coverage or substrate variation.

  18. Vanadia-based SCR Catalysts Supported on Tungstated and Sulfated Zirconia: Influence of Doping with Potassium

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Boghosian, Soghomon; Kustov, Arkadii

    2007-01-01

    A series of vanadium-based SCR catalysts supported on sulfated or tungstated ZrO2 were synthesized and characterized by means of N2-BET, XRD, NH3-TPD and in situ Raman spectroscopy. The effect of potassium doping on the properties of vanadia species is studied in detail. A number of catalyst...... and morphology, the surface composition and the molecular configuration of the dispersed vanadates. It was observed that poisoning with potassium had a negligible effect on the surface vanadate species (especially the V=O stretching frequency observed by in situ Raman spectroscopy) if supported on the sulfated...... the observed decrease in V=O stretching frequency and the higher proportion of dimers and higher polymers through coordination between K+ and two neighbouring V=O. The results suggest an increased resistance towards potassium doping for the vanadia-based catalysts supported on sulfated zirconia....

  19. Structural analyses of a rigid pavement overlaying a sub-surface void

    Science.gov (United States)

    Adam, Fatih Alperen

    Pavement failures are very hazardous for public safety and serviceability. These failures in pavements are mainly caused by subsurface voids, cracks, and undulation at the slab-base interface. On the other hand, current structural analysis procedures for rigid pavement assume that the slab-base interface is perfectly planar and no imperfections exist in the sub-surface soil. This assumption would be violated if severe erosion were to occur due to inadequate drainage, thermal movements, and/or mechanical loading. Until now, the effect of erosion was only considered in the faulting performance model, but not with regards to transverse cracking at the mid-slab edge. In this research, the bottom up fatigue cracking potential, caused by the combined effects of wheel loading and a localized imperfection in the form of a void below the mid-slab edge, is studied. A robust stress and surface deflection analysis was also conducted to evaluate the influence of a sub-surface void on layer moduli back-calculation. Rehabilitative measures were considered, which included a study on overlay and fill remediation. A series regression of equations was proposed that provides a relationship between void size, layer moduli stiffness, and the overlay thickness required to reduce the stress to its original pre-void level. The effect of the void on 3D pavement crack propagation was also studied under a single axle load. The amplifications to the stress intensity was shown to be high but could be mitigated substantially if stiff material is used to fill the void and impede crack growth. The pavement system was modeled using the commercial finite element modeling program Abaqus RTM. More than 10,000 runs were executed to do the following analysis: stress analysis of subsurface voids, E-moduli back-calculation of base layer, pavement damage calculations of Beaumont, TX, overlay thickness estimations, and mode I crack analysis. The results indicate that the stress and stress intensity are, on

  20. The presence of a (1 x 1) oxygen overlayer on ZnO(0001) surfaces and at Schottky interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Schleputz, Christian M.; Yang, Yongsoo; Husseini, Naji S.; Heinhold, Robert; Kim, Hyung-Suk; Allen, Martin W.; Durbin, Steven M.; Clarke, Roy (MacDiarmid); (Michigan)

    2012-05-10

    The atomic surface and interface structures of uncoated and metal-coated epi-polished ZnO(0001) Zn-polar wafers were investigated via surface x-ray diffraction. All uncoated samples showed the presence of a fully occupied (1 x 1) overlayer of oxygen atoms located at the on-top position above the terminating Zn atom, a structure predicted to be unstable by several density functional theory calculations. The same oxygen overlayer was clearly seen at the interface of ZnO with both elemental and oxidized metal Schottky contact layers. No significant atomic relaxations were observed at surfaces and interfaces processed under typical device fabrication conditions.

  1. A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst

    Science.gov (United States)

    Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

    2016-07-01

    Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe–Cr–Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1–3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 105 h‑1. The turnover frequency for the NO–CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading.

  2. A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst

    Science.gov (United States)

    Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

    2016-01-01

    Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe–Cr–Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1–3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 105 h−1. The turnover frequency for the NO–CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading. PMID:27388976

  3. A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst.

    Science.gov (United States)

    Misumi, Satoshi; Yoshida, Hiroshi; Hinokuma, Satoshi; Sato, Tetsuya; Machida, Masato

    2016-07-08

    Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe-Cr-Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1-3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 10(5) h(-1). The turnover frequency for the NO-CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading.

  4. First principles analysis of hydrogen chemisorption on Pd-Re alloyed overlayers and alloyed surfaces

    DEFF Research Database (Denmark)

    Pallassana, Venkataraman; Neurock, Matthew; Hansen, Lars Bruno;

    2000-01-01

    Gradient corrected periodic density functional theory (DFT-GGA) slab calculations were used to examine the chemisorption of atomic hydrogen on various Pd-Re alloyed overlayers and uniformly alloyed surfaces. Adsorption was examined at 33% surface coverage, where atomic hydrogen preferred the three......-fold fcc sites. The binding energy of atomic hydrogen is observed to vary by as much as 0.7 eV due to Pd-Re interactions. The computed adsorption energies were found to be between -2.35 eV [for monolayer Pd-on-Re, i.e., Pd-ML/Re(0001)] and -3.05 eV [for Pd-33 Re-66/Pd(111)]. A d-band weighting scheme...... was developed to extend the Hammer-Norskov surface reactivity model [Surf. Sci. 343, 211 (1995)] to the analysis of bimetallic Pd-Re alloyed systems. The hydrogen chemisorption energies are correlated linearly to the surface d-band center, which is weighted appropriately by the d-band coupling matrix elements...

  5. Photoemission from real iron surfaces and its relationship to light penetration of the overlayer

    Science.gov (United States)

    Momose, Yoshihiro; Suzuki, Daisuke; Sakurai, Takao; Nakayama, Keiji

    2015-02-01

    We report the photoemission from real iron surfaces at elevated temperatures, called thermally assisted photoemission (TAPE), and its relationship to the X-ray photoelectron spectroscopy (XPS) results. TAPE measurements were carried out using a Geiger counter under a gaseous atmosphere of He containing 1 % isobutane vapor at normal atmospheric pressure. A sample was initially heated to temperatures ranging from 25 to 353 °C under light irradiation at a certain wavelength of 200, 210, 220, and 230 nm, and then, wavelength was scanned from 300 to 170 nm at the final temperature. The values of a constant related to electron photoemission probability, αA, where A is identical with the Richardson constant, and photothreshold (photoelectric work function), ϕ, were obtained from a plot of the square root of the electron photoemission intensity against the photon energy; the αA values increased with temperature, and the ϕ values also increased with temperature. From the Arrhenius plot, the αA was found to have an activation energy Δ E αA = 0.096 eV. The activation energies of the surface oxygen component ratio Z = O2-/(OH + O2-) and the surface elemental composition ratio X = Fe/(O + N + C + Fe) obtained from the XPS data were also determined from their Arrhenius plots: Δ E Z = 0.113 eV and Δ E X = 0.039 eV, respectively. From a close resemblance between the latter activation energies and those of the Δ E αA and the Δ E a = 0.112-0.040 eV for the quantum yields (Momose et al. in Appl Phys A. doi: 10.1007/s00339-014-8589-7, 2014), it was found that the increase in the intensity of the TAPE with temperature was strongly associated with the increase in the values of Z and X with temperature. It was therefore concluded that the ability of the surface overlayer to pass the incident light became a rate-determining step to start the photoemission, which was decisively controlled by the temperature-dependent surface oxygen components and surface compositions. The

  6. Vanadia-silica and vanadia-cesium-silica catalysts for oxidation of SO2

    DEFF Research Database (Denmark)

    Pârvulescu, Vasile I.; Paun, Christina; Pârvulescu, Viorica

    2004-01-01

    of the V/Cs catalysts vanadia is dissolved in a sulfate containing molten salt. The activity of these catalysts for the oxidation of SO2 was tested in a gas containing 2% SO2, 19% O-2, 79% N-2 in the temperature range 523-823 K. Similar experiments with gases containing 10% H2O in the feed or with wet......)-based industrial catalyst, where kieselghur is used as carrier material. The high dispersion of vanadium in the studied catalysts results in an increased catalytic activity for the oxidation of SO2 contained in feed gases with low SO2 content....

  7. He atom-surface scattering: Surface dynamics of insulators, overlayers and crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Investigations in this laboratory have focused on the surface structure and dynamics of ionic insulators and on epitaxial growth onto alkali halide crystals. In the later the homoepitaxial growth of NaCl/NaCl(001) and the heteroepitaxial growth of KBr/NaCl(001), NaCl/KBr(001) and KBr/RbCl(001) have been studied by monitoring the specular He scattering as a function of the coverage and by measuring the angular and energy distributions of the scattered He atoms. These data provide information on the surface structure, defect densities, island sizes and surface strain during the layer-by-layer growth. The temperature dependence of these measurements also provides information on the mobilities of the admolecules. He atom scattering is unique among surface probes because the low-energy, inert atoms are sensitive only to the electronic structure of the topmost surface layer and are equally applicable to all crystalline materials. It is proposed for the next year to exploit further the variety of combinations possible with the alkali halides in order to carry out a definitive study of epitaxial growth in the ionic insulators. The work completed so far, including measurements of the Bragg diffraction and surface dispersion at various stages of growth, appears to be exceptionally rich in detail, which is particularly promising for theoretical modeling. In addition, because epitaxial growth conditions over a wide range of lattice mismatches is possible with these materials, size effects in growth processes can be explored in great depth. Further, as some of the alkali halides have the CsCl structure instead of the NaCl structure, we can investigate the effects of the heteroepitaxy with materials having different lattice preferences. Finally, by using co-deposition of different alkali halides, one can investigate the formation and stability of alloys and even alkali halide superlattices.

  8. Electronic and structural characterizations of unreconstructed {l_brace}0001{r_brace} surfaces and the growth of graphene overlayers

    Energy Technology Data Exchange (ETDEWEB)

    Emtsev, Konstantin

    2009-06-03

    The present work is focused on the characterization of the clean unreconstructed SiC{l_brace}0001{r_brace} surfaces and the growth of graphene overlayers thereon. Electronic properties of SiC surfaces and their interfaces with graphene and few layer graphene films were investigated by means of angle resolved photoelectron spectroscopy, X-ray photoelectron spectroscopy and low energy electron diffraction. Structural characterizations of the epitaxial graphene films grown on SiC were carried out by atomic force microscopy and low energy electron microscopy. Supplementary data was obtained by scanning tunneling microscopy. (orig.)

  9. He atom surface spectroscopy: Surface lattice dynamics of insulators, metals and metal overlayers

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    During the first three years of this grant (1985--1988) the effort was devoted to the construction of a state-of-the-art He atom scattering (HAS) instrument which would be capable of determining the structure and dynamics of metallic, semiconductor or insulator crystal surfaces. The second three year grant period (1988--1991) has been dedicated to measurements. The construction of the instrument went better than proposed; it was within budget, finished in the proposed time and of better sensitivity and resolution than originally planned. The same success has been carried over to the measurement phase where the concentration has been on studies of insulator surfaces, as discussed in this paper. The experiments of the past three years have focused primarily on the alkali halides with a more recent shift to metal oxide crystal surfaces. Both elastic and inelastic scattering experiments were carried out on LiF, NaI, NaCl, RbCl, KBr, RbBr, RbI, CsF, CsI and with some preliminary work on NiO and MgO.

  10. Vanadia on sulphated-ZrO2, a promising catalyst for NO abatement with ammonia in alkali containing flue gases

    DEFF Research Database (Denmark)

    Kustov, Arkadii; Kustova, Marina; Fehrmann, Rasmus

    2005-01-01

    Vanadia supported on TiO2, ZrO2, and sulphated-ZrO2 have been prepared. These catalysts were characterized by elemental analysis, N-2-BET, XRD, FTIR, and NH3-TPD methods. The stability of surface sulphated groups, studied by FTIR- spectroscopy, was found to depend dramatically on the temperature...... in the total acidity is less pronounced in this case. The results of NO SCR with ammonia reveal a noticeable shift of the maximum catalytic activity towards higher temperatures in going from the conventional catalyst to vanadia supported on sulphated zirconia. The loading of the catalysts with potassium leads...... to considerable decrease of their catalytic activity, and to a shift of the maximum catalytic activity towards lower temperatures. Among all the catalysts, V2O5/sulphated-ZrO2 reveals the highest resistance towards alkali poisoning. The presence Of SO2 in the reaction mixture was found to enhance stability...

  11. Structure and properties of samarium overlayer and Sm/Rh surface alloy on Rh(1O0)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The structure and properties of Sm overlayer and Sm/Rh surface alloy have been investigated with Auger electron spectroscopy (AES), low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), and temperature programmed desorption spectroscopy (TDS). The growth of Sm on Rh(100) at room temperature (RT) appears following the Stranski-Krastanov growth mode and only the trivalent state Sm is observed from XPS results. Thermal treatment of the Sm film at 900 K leads to the formation of ordered surface alloy which shows the c(5 2 × 2 )R45°and c(2 × 2) LEED patterns. Annealing the Sm film at temperature above 400 K makes the binding energy (B.E.) of Sm 3d5/2 shift to higher energy by 0.7 eV, which indicates charge transfer from Sm to Rh(100) substrate, causing the increase of CO desorption temperature.

  12. Oxidative dehydrogenation of isobutane over vanadia catalysts supported by titania nanoshapes

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Shannon; Rondinone, Adam J.; Tsai, Yu-Tong; Schwartz, Viviane; Overbury, Steven H.; Idrobo, Juan-Carlos; Wu, Zili

    2016-04-01

    Support plays a complex role in catalysis by supported metal oxides and the exact support effect still remains elusive. One of the approaches to gain fundamental insights into the support effect is to utilize model support systems. In this paper, we employed for the first time titania nanoshapes as the model supports and investigated how the variation of surface structure of the support (titania, TiO2) impacts the catalysis of supported oxide (vanadia, VOx). TiO2 truncated rhombi, spheres and rods were synthesized via hydrothermal method and characterized with XRD and TEM. These TiO2 nanoshapes represent different mixtures of surface facets including [1 0 1], [0 1 0] and [0 0 1] and were used to support vanadia. The structure of supported VOx species was characterized in detail with in situ Raman spectroscopy as a function of loading on the three TiO2 nanoshapes. Oxidative dehydrogenation (ODH) of isobutane to isobutene was used as a model reaction to test how the support shape influences the activity, selectivity and activation energy of the surface VOx species. It was shown that the shape of TiO2 support does not pose evident effect on either the structure of surface VOx species or the catalytic performance of surface VOx species in isobutane ODH reaction. This insignificant support shape effect was ascribed to the small difference in the surface oxygen vacancy formation energy among the different TiO2 surfaces and the multi-faceting nature of the TiO2 nanoshapes.

  13. Impact of Solvent on Photocatalytic Mechanisms: Reactions of Photodesorption Products with Ice Overlayers on the TiO2(110) Surface

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Mingmin; Henderson, Michael A.

    2011-04-07

    The effects of water and methanol ice overlayers on the photodecomposition of acetone on rutile TiO2(110) were evaluated in ultrahigh vacuum (UHV) using photon stimulated desorption (PSD) and temperature programmed desorption (TPD). In the absence of ice overlayers, acetone photodecomposed on TiO2(110) at 95 K by ejection of a methyl radical into the gas phase and formation of acetate on the surface. With ice overlayers, the methyl radicals are trapped at the interface between TiO2(110) and the ice. When water ice was present, these trapped methyl radicals reacted either with each other to form ethane or with other molecules in the ice (e.g., water or displaced acetone) to form methane (CH4), ethane (CH3CH3) and other products (e.g., methanol), with all of these products trapped in the ice. The new products were free to revisit the surface or depart during desorption of the ice. When methanol ice was present, methane formation came about only from reaction of trapped methyl radicals with the methanol ice. Methane and ethane slowly leaked through methanol ice overlayers into vacuum at 95 K, but not through water ice overlayers. Different degrees of site competition between water and acetone, and between methanol and acetone led to different hydrogen abstraction pathways in the two ices. These results provide new insights into product formation routes and solution-phase radical formation mechanisms that are important in heterogeneous photocatalysis.

  14. The characterization and activity of F-doped vanadia/titania for the selective catalytic reduction of NO with NH3 at low temperatures.

    Science.gov (United States)

    Li, Yuntao; Zhong, Qin

    2009-12-30

    A F-doped vanadia/titania catalyst has been developed by partly substituting the lattice oxygen of the catalyst with fluorine, using NH(4)F as a precursor. The aim of this novel design was to promote the activity of a catalyst with low vanadia loading in the low-temperature selective catalytic reduction of NO with NH(3). Analysis by N(2) physisorption, XPS, ICP, XRD, ESR and PL spectra showed that fluorine doping facilitated the formation of V(4+) and Ti(3+) ions mainly by charge compensation, promoted the distribution of vanadium on the catalyst surface, and increased the amount of surface superoxide ions. The catalytic activity of NO removal was promoted by F-doping. And the catalyst with [F]/[Ti]=1.35 x 10(-2) showed the highest NO removal efficiency in SCR reaction at low temperatures.

  15. Generation of nanocrystalline surface layer in short pulse laser processing of metal targets under conditions of spatial confinement by solid or liquid overlayer

    Science.gov (United States)

    Shugaev, Maxim V.; Shih, Cheng-Yu; Karim, Eaman T.; Wu, Chengping; Zhigilei, Leonid V.

    2017-09-01

    The effect of spatial confinement by a solid or liquid overlayer on short pulse laser-induced surface microstructure modification is investigated in a series of large-scale atomistic simulations performed for Ag targets irradiated in the regime of melting and resolidification, below the thresholds for laser spallation and ablation. For Ag targets with free surfaces, the formation of a nanocrystalline region with random crystallographic grain orientation is observed under irradiation conditions leading to the generation of numerous sub-surface voids that slow down the solidification process. When no voids are generated, the resolidification produces grains misoriented with respect to the bulk of the target by just several degrees and separated from each other by low angle grain boundaries or dislocation walls. The presence of a liquid or solid overlayer suppresses nucleation of sub-surface voids, provides an additional pathway for cooling through the heat conduction to the overlayer, and facilitates the formation of nanocrystalline structure in a region of the metal target adjacent to the overlayer. Moreover, the stabilizing effect of the solid overlayer may result in an incomplete melting of metal in the vicinity of the interface, making it possible for grains growing from the interface to retain ;memory; of the target orientation and to produce nanocrystalline interfacial region with small misorientation of grains with respect to the bulk of the target. In all simulations, the nanocrystalline layers generated by laser processing of single crystal Ag targets are characterized by a high density of stacking faults, twin boundaries, and point defects produced in the course of the rapid resolidification.

  16. Platinum overlayers on Co(0001) and Ni(111): numerical simulation of surface alloying

    Science.gov (United States)

    Légaré, P.; Cabeza, G. F.; Castellani, N. J.

    1999-11-01

    The surface alloying of one and two monolayers (ML) of platinum deposited on Ni(111) and Co(0001) were studied by means of the ECT-BFS method. The 1 ML deposit appears to be very stable on both substrates. Platinum can diffuse at high temperature only, the large activation barrier being represented by the first substrate layer. On the contrary, the stability of the 2 ML deposit is poor so that alloying is easily obtained. In both cases, the platinum diffusion produces metastable states. The lowest-energy states exhibit a propensity for platinum dilution in a limited region below the surface. The initial platinum thickness determines not only the features of the alloyed region, but also the surface concentration. The surface alloys have features qualitatively similar to those reported for the (111) surface of bulk Pt-Ni and Pt-Co alloys: a platinum-rich surface and oscillating concentration profiles.

  17. Repair, Evaluation, Maintenance, and Rehabilitation Research Program Overlays on Horizontal Concrete Surfaces: Case Histories

    Science.gov (United States)

    1994-02-01

    thermal expansion and contraction and autogenous shrinkage. No attempt was made to repair the cracks. During an inspection in August of 1984, it was...LATEX- ’ * """* 9 MODIFIED CONCRETE SLOPE PATCH IF NECESSARY EXOSTING CRACK TO MAINTAIN DRAINAGE Figure 27. Typical surface repair, Mississippi River...102-mm) deep densely graded aggregate base. The sand base extended to the ditch foreslopes to provide drainage of subbase. The average daily

  18. XPS investigation of ion beam induced conversion of GaAs(0 0 1) surface into GaN overlayer

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Praveen [Surface Physics and Nanostructure Group, National Physical Laboratory, New Delhi 110012 (India); Department of Physics, Indian Institute of Technology, New Delhi 110016 (India); Kumar, Mahesh; Govind [Surface Physics and Nanostructure Group, National Physical Laboratory, New Delhi 110012 (India); Mehta, B.R. [Department of Physics, Indian Institute of Technology, New Delhi 110016 (India); Shivaprasad, S.M., E-mail: smsprasad@jncasr.ac.in [Jawaharlal Nehru Centre for Advanced Scientific Research, International Center for Material Science and Chemistry and Physics Materials Unit, Jakkur, 560064 Bangalore, Karnataka (India)

    2009-10-30

    For the advance of GaN based optoelectronic devices, one of the major barriers has been the high defect density in GaN thin films, due to lattice parameter and thermal expansion incompatibility with conventional substrates. Of late, efforts are focused in fine tuning epitaxial growth and in search for a low temperature method of forming low defect GaN with zincblende structure, by a method compatible to the molecular beam epitaxy process. In principle, to grow zincblende GaN the substrate should have four-fold symmetry and thus zincblende GaN has been prepared on several substrates including Si, 3C-SiC, GaP, MgO, and on GaAs(0 0 1). The iso-structure and a common shared element make the epitaxial growth of GaN on GaAs(0 0 1) feasible and useful. In this study ion-induced conversion of GaAs(0 0 1) surface into GaN at room temperature is optimized. At the outset a Ga-rich surface is formed by Ar{sup +} ion bombardment. Nitrogen ion bombardment of the Ga-rich GaAs surface is performed by using 2-4 keV energy and fluence ranging from 3 x 10{sup 13} ions/cm{sup 2} to 1 x 10{sup 18} ions/cm{sup 2}. Formation of surface GaN is manifested as chemical shift. In situ core level and true secondary electron emission spectra by X-ray photoelectron spectroscopy are monitored to observe the chemical and electronic property changes. Using XPS line shape analysis by deconvolution into chemical state, we report that 3 keV N{sub 2}{sup +} ions and 7.2 x 10{sup 17} ions/cm{sup 2} are the optimal energy and fluence, respectively, for the nitridation of GaAs(0 0 1) surface at room temperature. The measurement of electron emission of the interface shows the dependence of work function to the chemical composition of the interface. Depth profile study by using Ar{sup +} ion sputtering, shows that a stoichiometric GaN of 1 nm thickness forms on the surface. This, room temperature and molecular beam epitaxy compatible, method of forming GaN temperature can serve as an excellent template for

  19. Does Each Atom Count in the Reactivity of Vanadia Nanoclusters?

    Science.gov (United States)

    Zhang, Mei-Qi; Zhao, Yan-Xia; Liu, Qing-Yu; Li, Xiao-Na; He, Sheng-Gui

    2017-01-11

    Vanadium oxide cluster anions (V2O5)nVxOy(-) (n = 1-31; x = 0, 1; and x + y ≤ 5) with different oxygen deficiencies (Δ = 2y-1-5x = 0, ± 1, and ±2) have been prepared by laser ablation and reacted to abstract hydrogen atoms from alkane molecules (n-butane) in a fast flow reactor. When the cluster size n is less than 25, the Δ = 1 series [(V2O5)nO(-) clusters] that can contain atomic oxygen radical anions (O(•-)) generally have much higher reactivity than the other four cluster series (Δ = -2, -1, 0, and 2), indicating that each atom counts in the hydrogen-atom abstraction (HAA) reactivity. Unexpectedly, all of the five cluster series have similar HAA reactivity when the cluster size is greater than 25. The critical dimension of vanadia particles separating the cluster behavior (each atom counts) from the bulk behavior (each atom contributes a little part) is thus about 1.6 nm (∼V50O125). The strong electron-phonon coupling of the vanadia particles has been proposed to create the O(•-) radicals (V(5+) = O(2-)+ heat → V(4+)-O(•-)) for the n > 25 clusters with Δ = -2, -1, 0, and 2. Such a mechanism is supported by a comparative study with the scandium system [(Sc2O3)nScxOy(-) (n = 1-29; x = 0, 1; and x + y ≤ 4)] for which the Δ = 1 series [(Sc2O3)nO(-) clusters] always have much higher HAA reactivity than the other cluster series.

  20. On the Role of Vanadia Species for VOx/SiO2 in the Selective Oxidation of Methane

    Institute of Scientific and Technical Information of China (English)

    Shaojun Miao; Ding Ma; Qingjun Zhu; Heng Zheng; Guoqing Jia; Shutian Zhou; Xinhe Bao

    2005-01-01

    Various VOx/SiO2 catalysts were prepared by the methods of physical mixing, conventional wetness impregnation and ultrasonication-assistant impregnation. The catalysts were characterized by XRD, UV-Vis DRS, Raman, TPR, ESR and TPSR techniques and the nature of the vanadium species were correlated to their catalytic performance in the reaction of direct conversion of methane to formaldehyde. It is concluded that highly dispersed monomeric and low oligomeric vanadia species are formed on the sample prepared with both traditional wetness impregnation method and ultrasonication-assistant impregnation, whereas in the latter case, the amount of oligomeric vanadia species is much smaller. The V2O5 microcrystallines are the dominant species on the material prepared by physical mixing method.During the selective oxidation of methane, Vv species are reduced to VⅣ paramagnetic species and both microcrystalline V2O5 species and oligomeric vanadia species are found to further disperse and transform into tetrahedral vanadia species. Based on the results of UV Raman spectroscopy and TPSR, CO2 is suggested to be formed via two different routes, in which one is from the sequence reaction of CH4 → HCHO → CO → CO2 over monomeric vanadia species, and the other is from the direct oxidation of methane to CO2 over oligomeric vanadia species. Oligomeric vanadia species is more active than monomeric vanadia species for methane activation.

  1. Vanadia on sulphated-ZrO2, a promising catalyst for NO abatement with ammonia in alkali containing flue gases

    DEFF Research Database (Denmark)

    Kustov, Arkadii; Kustova, Marina; Fehrmann, Rasmus

    2005-01-01

    to almost complete depression of the samples acidity and considerable weakening of the remaining acid sites for TiO2 and ZrO2 based systems. For the sulphated system, surface sulphur groups, due to their strong acidity, represent attractive sites for the localization of potassium oxide and the decrease...... of the calcination of the samples. No considerable decomposition of surface sulphates was observed below 350 ° C. The influence of potassium oxide additives on the acidity and activity in NO SCR with ammonia was studied. It was found that the introduction of small amounts of potassium (K/V molar ratio ... in the total acidity is less pronounced in this case. The results of NO SCR with ammonia reveal a noticeable shift of the maximum catalytic activity towards higher temperatures in going from the conventional catalyst to vanadia supported on sulphated zirconia. The loading of the catalysts with potassium leads...

  2. Evolution of the SrTiO3 surface electronic state as a function of LaAlO3 overlayer thickness

    Science.gov (United States)

    Plumb, N. C.; Kobayashi, M.; Salluzzo, M.; Razzoli, E.; Matt, C. E.; Strocov, V. N.; Zhou, K. J.; Shi, M.; Mesot, J.; Schmitt, T.; Patthey, L.; Radović, M.

    2017-08-01

    The novel electronic properties emerging at interfaces between transition metal oxides, and in particular the discovery of conductivity in heterostructures composed of LaAlO3 (LAO) and SrTiO3 (STO) band insulators, have generated new challenges and opportunities in condensed matter physics. Although the interface conductivity is stabilized when LAO matches or exceeds a critical thickness of 4 unit cells (uc), other phenomena such as a universal metallic state found on the bare surface of STO single crystals and persistent photon-triggered conductivity in otherwise insulating STO-based interfaces raise important questions about the role of the LAO overlayer and the possible relations between vacuum/STO and LAO/STO interfaces. Here, using angle-resolved photoemission spectroscopy (ARPES) on in situ prepared samples complemented by resonant inelastic X-ray scattering (RIXS), we study how the metallic STO surface state evolves during the growth of a crystalline LAO overlayer. In all the studied samples, the character of the conduction bands, their carrier densities, the Ti3+ crystal field, and the response to photon irradiation bear strong similarities. Nevertheless, we report here that studied LAO/STO interfaces exhibit an instability toward an apparent 2 × 1 folding of the Fermi surface at and above a 4 uc thickness threshold, which distinguishes these heterostructures from bare STO and sub-critical-thickness LAO/STO.

  3. Fe90合金等离子堆焊工艺的研究%Research on Plasma Surfacing Process of Fe90 Overlay Deposit

    Institute of Scientific and Technical Information of China (English)

    鲁海龙; 康建东

    2012-01-01

    采用等离子弧堆焊工艺将Fe90合金堆焊到低碳钢表面;采用洛氏硬度仪、湿砂橡胶轮磨料磨损试验机对不同规范下堆焊试样的硬度、耐磨性能进行测试;采用OM及SEM对堆焊层进行显微组织分析,研究堆焊电流对堆焊层组织、性能的影响规律和作用机理.结果表明,堆焊层表面性能优于侧面;当堆焊电流为180A时,堆焊层性能取得最佳值,其表面硬度为67.7HRC,耐磨性能最好.%Fe90 alloy was surfaced on low carbon steel by plasma surfacing. The microhardness and wear resistance of surfacing samples test were studied by hardness test and wet sand rubber wheel abrasive abrasion tester. The microstructure of surfacing layer was studied by OM and SEM. The effects of surfacing current on the properties and microstructure of overlay deposit were researched. The results indicate that the properties of overlay deposit surface are better than that of side. The optimal result is acquired when surfacing current is 180A, the surface hardness is 67.7 HRC and then the abrasive resistance is best

  4. Oxidative dehydrogenation of ethylbenzene using nitrous oxide over vanadia-magnesia catalysts

    NARCIS (Netherlands)

    Shiju, N.R.; Anilkumar, M.; Gokhale, S.P.; Rao, B.S.; Satyanarayana, C.V.V.

    2011-01-01

    A series of V-Mg-O catalysts with different loadings of vanadia were prepared by the wet impregnation method and the effect of the local structure of these catalysts on the oxidative dehydrogenation of ethylbenzene with N2O was investigated. High styrene selectivity (97%) was obtained at 773 K. The

  5. Deactivation of vanadia-based commercial SCR catalysts by polyphosphoric acids

    DEFF Research Database (Denmark)

    Castellino, Francesco; Rasmussen, Søren Birk; Jensen, Anker Degn;

    2008-01-01

    Commercial vanadia-based SCR monoliths have been exposed to flue gases in a pilot-scale Setup into which phosphoric acid has been added and the deactivation has been followed during the exposure time. Separate measurements by SMPS showed that the phosphoric acid formed polyphosphoric acid aerosol...

  6. Rhodium particles supported by thin vanadia films as model systems for catalysis: An electron microscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Penner, S. [Institut fuer Physikalische Chemie, Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Wang, D. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg, 4-6, D-14195 Berlin (Germany); Schloegl, R. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg, 4-6, D-14195 Berlin (Germany); Hayek, K. [Institut fuer Physikalische Chemie, Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria)]. E-mail: konrad.hayek@uibk.ac.at

    2005-07-22

    Well-shaped Rh particles grown epitaxially on NaCl surfaces were coated with a 25 nm layer of crystalline vanadium oxide by reactive deposition in 10{sup -4} mbar oxygen. The Rh/VO{sub x} film was subjected to consecutive heat treatments in 1 bar oxygen and in 1 bar hydrogen up to 673 K. The structural and morphological changes were monitored by (high-resolution) transmission electron microscopy, selected area electron diffraction and electron energy-loss spectroscopy and compared to the alterations of a bare vanadium oxide film treated under equal conditions. The stoichiometry and structure of the VO{sub x} support depend on the temperature of the NaCl template and on the deposition rate. Low deposition rates and high substrate temperatures favour the generation of a pure V{sub 2}O{sub 3} phase, with both V{sub 2}O{sub 3} and the Rh particles in epitaxial relation to NaCl (001). A treatment in 1 bar O{sub 2} between 300 and 573 K converts the supporting oxide into mixed V{sub 2}O{sub 3}, VO{sub 2} and V{sub 2}O{sub 5} phases. Oxidation at 673 K induces a complete reconstruction into a single V{sub 2}O{sub 5} phase, while an oxygen treatment at 723 K transforms also the Rh particles into ({beta})Rh{sub 2}O{sub 3}. Reduction of the bare V{sub 2}O{sub 5} film in 1 bar hydrogen yields cubic VO at 673 K, but reduction of the Rh/V{sub 2}O{sub 5} film leads to VO formation already at 473 K. Finally, a reduction of vanadia-supported Rh particles at and above 573 K results in the formation of Rh/V alloy structures.

  7. RADAR PPI Scope Overlay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — RADAR PPI Scope Overlays are used to position a RADAR image over a station at the correct resolution. The archive maintains several different RADAR resolution types,...

  8. [Experience in overlay tympanoplasty].

    Science.gov (United States)

    Peng, Ben-gang; Miao, Xu-tao; Wang, Xin; Sun, Yi-qing; Liu, Zhi-ying; Li, Yong-xin

    2009-05-01

    To explore the experience and value of overlay tympanoplasty. Sixty-three ears with overlay tympanoplasty were reviewed and followed up for the external auditory canal, tympanic membrane and hearing. The diseases of the patients included middle ear cholesteatoma in 25 ears and chronic suppurative otitis media in 38 ears. The surgical techniques involved three kinds: overlay tympanoplasty, overlay tympanoplasty with canal wall up mastoidectomy and overlay tympanoplasty with canal wall down mastoidectomy. In middle ear cholesteatoma and suppurative otitis media patients, the case received the three techniques are 4, 17, 4 ears and 19, 18, 1 ears respectively. All patients gained stage I incision cure. Followed up for 0.5 to 3.5 years respectively, the external auditory canal was wide and tympanic membrane gained a good shape. The hearing in all case kept intact or increased while hearing decrease did not occur. Complications were free in patients with punctual visit. Overlay tympanoplasty has positive significance in treating the chronic otitis media with the merits of standard procedure, sufficient operative field and thorough erosion elimination.

  9. New holographic overlays

    Science.gov (United States)

    Hopwood, Anthony I.

    1991-10-01

    This paper discusses a new type of holographic overlay, FLASHPRINT, which may be used in both security and packaging applications. Unlike the more common embossed holograms currently used, FLASHPRINT leads to reduced set-up costs and offers a simpler process. This reduces the long lead times characteristic of the existing technology and requires the customer to provide only two-dimensional artwork. The overlay material contains a covert 2-D image. The image may be switched on or off by simply tilting the overlay in a light source. The overlay is replayed in the 'on' position to reveal the encoded security message as a highly saturated gold colored image. This effect is operable for a wide range of lighting conditions and viewing geometries. In the 'off' position the overlay is substantially transparent. These features make the visual effect of the overlay attractive to incorporate into product design. They may be laminated over complex printed artwork such as labels and security passes without masking the printed message. When switched 'on' the image appears both sharp and more than seven times brighter than white paper. The image remains sharp and clear even in less favorable lighting conditions. Although the technique offers a low set-up cost for the customer, through its simplicity, it remains as technically demanding and difficult to counterfeit as any holographic process.

  10. Analysis of the electrodeposition and surface chemistry of CdTe, CdSe, and CdS thin films through substrate-overlayer surface-enhanced Raman spectroscopy.

    Science.gov (United States)

    Gu, Junsi; Fahrenkrug, Eli; Maldonado, Stephen

    2014-09-02

    The substrate-overlayer approach has been used to acquire surface enhanced Raman spectra (SERS) during and after electrochemical atomic layer deposition (ECALD) of CdSe, CdTe, and CdS thin films. The collected data suggest that SERS measurements performed with off-resonance (i.e. far from the surface plasmonic wavelength of the underlying SERS substrate) laser excitation do not introduce perturbations to the ECALD processes. Spectra acquired in this way afford rapid insight on the quality of the semiconductor film during the course of an ECALD process. For example, SERS data are used to highlight ECALD conditions that yield crystalline CdSe and CdS films. In contrast, SERS measurements with short wavelength laser excitation show evidence of photoelectrochemical effects that were not germane to the intended ECALD process. Using the semiconductor films prepared by ECALD, the substrate-overlayer SERS approach also affords analysis of semiconductor surface adsorbates. Specifically, Raman spectra of benzenethiol adsorbed onto CdSe, CdTe, and CdS films are detailed. Spectral shifts in the vibronic features of adsorbate bonding suggest subtle differences in substrate-adsorbate interactions, highlighting the sensitivity of this methodology.

  11. Zeolite Based SCR Catalysts - An Interesting Alternative To Vanadia-Titania Systems

    Energy Technology Data Exchange (ETDEWEB)

    Devadas, M.; Kroecher, O.; Wokaun, A.

    2004-03-01

    Metal exchanged zeolite catalysts were tested for the selective catalytic reduction of NO{sub x} with ammonia (NH{sub 3}-SCR) and compared with a vanadia based catalyst. With pure NO in the feed Cu-ZSM5 exhibited a better NO{sub x} conversion than Fe-ZSM5 and V{sub 2}O{sub 5}/WO{sub 3}-TiO{sub 2} at all temperatures. The main drawback of Cu-ZSM5 is the required excess of ammonia due to oxidation of NH{sub 3} to N{sub 2} (SCO). For a feed ratio of NO:NO{sub 2} = 0.5, all catalysts showed a high activity at elevated temperatures, but Fe-ZSM5 and Cu-ZSM5 performed better than the vanadia catalyst at lower temperatures. (author)

  12. Oxidation of the Si(100) surface promoted by Sr overlayer - An X-ray photoemission study. [high temperature superconductors

    Science.gov (United States)

    Mesarwi, A.; Fan, W. C.; Ignatiev, A.

    1990-01-01

    The interaction of strontium films with the underlaying Si (100) surface and the Sr-promoted low-temperature oxidation of Si were investigated, using XPS, at three different Sr coverages (theta): theta = 0.55 monolayer (ML), theta = 1 ML, and theta = 1.85 ML. Oxygen adsorption was studied both at room temperature and at 500 C, and at oxygen exposures up to 2 x 10 to the 6th L (1 L = 10 to the -6th torr) and 2 x 10 to the 5th L, respectively. The XPS spectra of the Si2p, O1s, and Sr3d core levels were measured for the atomically clean Si, the Sr-covered Si, and for the Sr-covered Si after each oxygen exposure. Results indicate that Sr interacts with the Si(100) surface forming a strong ionic bond, and that Sr promotes the oxidation of the Si (100) surface.

  13. Cyclohexene Photo-oxidation over Vanadia Catalyst Analyzed by Time Resolved ATR-FT-IR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Frei, Heinz; Mul, Guido; Wasylenko, Walter; Hamdy, M. Sameh; Frei, Heinz

    2008-06-04

    Vanadia was incorporated in the 3-dimensional mesoporous material TUD-1 with a loading of 2percent w/w vanadia. The performance in the selective photo-oxidation of liquid cyclohexene was investigated using ATR-FT-IR spectroscopy. Under continuous illumination at 458 nm a significant amount of product, i.e. cyclohexenone, was identified. This demonstrates for the first time that hydroxylated vanadia centers in mesoporous materials can be activated by visible light to induce oxidation reactions. Using the rapid scan method, a strong perturbation of the vanadyl environment could be observed in the selective oxidation process induced by a 458 nm laser pulse of 480 ms duration. This is proposed to be caused by interaction of the catalytic centre with a cyclohexenyl hydroperoxide intermediate. The restoration of the vanadyl environment could be kinetically correlated to the rate of formation of cyclohexenone, and is explained by molecular rearrangement and dissociation of the peroxide to ketone and water. The ketone diffuses away from the active center and ATR infrared probing zone, resulting in a decreasing ketone signal on the tens of seconds time scale after initiation of the photoreaction. This study demonstrates the high potential of time resolved ATR FT-IR spectroscopy for mechanistic studies of liquid phase reactions by monitoring not only intermediates and products, but by correlating the temporal behavior of these species to molecular changes of the vanadyl catalytic site.

  14. Synergetic Hybrid Aerogels of Vanadia and Graphene as Electrode Materials of Supercapacitors

    Directory of Open Access Journals (Sweden)

    Xuewei Fu

    2016-08-01

    Full Text Available The performance of synergetic hybrid aerogel materials of vanadia and graphene as electrode materials in supercapacitors was evaluated. The hybrid materials were synthesized by two methods. In Method I, premade graphene oxide (GO hydrogel was first chemically reduced by L-ascorbic acid and then soaked in vanadium triisopropoxide solution to obtain V2O5 gel in the pores of the reduced graphene oxide (rGO hydrogel. The gel was supercritically dried to obtain the hybrid aerogel. In Method II, vanadium triisopropoxide was hydrolyzed from a solution in water with GO particles uniformly dispersed to obtain the hybrid gel. The hybrid aerogel was obtained by supercritical drying of the gel followed by thermal reduction of GO. The electrode materials were prepared by mixing 80 wt % hybrid aerogel with 10 wt % carbon black and 10 wt % polyvinylidene fluoride. The hybrid materials in Method II showed higher capacitance due to better interactions between vanadia and graphene oxide particles and more uniform vanadia particle distribution.

  15. Overlay mark optimization for thick-film resist overlay metrology

    Institute of Scientific and Technical Information of China (English)

    Zhu Liang; Li Jie; Zhou Congshu; Gu Yili; Yang Huayue

    2009-01-01

    For thick resist implant layers, such as a high voltage P well and a deep N well, systematic and uncorrectable overlay residues brought about by the tapered resist profiles were found. It was found that the tapered profile is closely related to the pattern density. Potential solutions of the manufacturing problem include hardening the film solidness or balancing the exposure density. In this paper, instead of focusing on the process change methodology,we intend to solve the issue of the overlay metrology error from the perspective of the overlay mark design. Based on the comparison of the overlay performances between the proposed overlay mark and the original design, it is shown that the optimized overlay mark target achieves better performance in terms of profiles, dynamic precision,tool induced shift (TIS), and residues. Furthermore, five types of overlay marks with dummy bars are studied, and a recommendation for the overlay marks is given.

  16. Evaluation of the Effect of Different Surface Treatments on Luting CAD/CAM Composite Resin Overlay Workpieces.

    Science.gov (United States)

    Kassotakis, Emmanuel M; Stavridakis, Minos; Bortolotto, Tissiana; Ardu, Stefano; Krejci, Ivo

    2015-12-01

    To evaluate the effect of different surface treatments on luting CAD/CAM composite resin workpieces. One-hundred eight (108) composite CAD/CAM block sections (Lava Ultimate) 3 mm in thickness were polished up to 4000 grit and then randomly assigned to 6 experimental groups according to the applied surface treatment (no treatment, sodium bicarbonate [NaHCO3], glycine, alumina [Al2O3], CoJet, and SilJet). After standardized sandblasting procedures, 2 block sections from each group were randomly chosen for the qualitative SEM evaluation of the sandblasted surfaces. The remaining 96 CAD/CAM block sections were luted in pairs using a bonding agent (Single Bond) and a restorative composite resin (Filtek Ultimate). Specimens were aged for 2 weeks in 37°C water with 3000 thermal cycles (5°C/55°C), the microtensile test was performed (n = 30), and the values were statistically analyzed with ANOVA and Tukey's HSD post-hoc test (p = 0.05). The qualitative SEM evaluation of the sandblasted surfaces showed that sodium bicarbonate and glycine had almost no conditioning effect on the CAD/CAM composite resin. In contrast, aluminum oxide, CoJet, and SilJet had a profound conditioning effect on the CAD/CAM composite resin. No treatment, sodium bicarbonate, and glycine specimens were debonded after thermal stressing (0 MPa), while aluminum oxide, CoJet, and SilJet showed high microtensile values (Al2O3: 104.45 ± 18.76 MPa; CoJet: 105.55 ± 11.88 MPa; SilJet: 105.02 ± 20.84 MPa), which were not statistically significantly different from each other. Aluminum oxide-based sandblasting powders are the best choice for the surface treatment of CAD/ CAM workpieces.

  17. Nonhydrolytic vanadia-titania xerogels. Synthesis, characterization, and behavior in the selective catalytic reduction of NO by NH{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Mutin, P. Hubert; Popa, Aurelian F.; Vioux, Andre [Chimie Moleculaire et Organisation du Solide-UMR CNRS 5637,Universite Montpellier 2, case 007, Place E. Bataillon, 34095 Montpellier Cedex 5 (France); Delahay, Gerard; Coq, Bernard [Laboratoire de Materiaux Catalytiques et Catalyse en Chimie Organique-UMR CNRS 5618, ENSCM, 8 rue de l' Ecole Normale, 34296 Montpellier Cedex 5 (France)

    2006-12-01

    V{sub 2}O{sub 5}-TiO{sub 2} catalysts with V{sub 2}O{sub 5} contents ranging from 6 to 18wt% were obtained by calcination at 773K of xerogels prepared by a nonhydrolytic sol-gel route from VOCl{sub 3}, TiCl{sub 4}, and {sup i}Pr{sub 2}O. These materials were characterized by X-ray diffraction, micro-FT-Raman spectroscopy, static {sup 51}V NMR, SEM, N{sub 2} physisorption, temperature-programmed desorption of ammonia (NH{sub 3}-TPD), and temperature-programmed reduction by H{sub 2} (H{sub 2}-TPR). In all cases mesoporous solids were obtained with specific surface areas up to 87m{sup 2}g{sup -1}. Raman spectroscopy indicated the presence of the same vanadia species as in conventional vanadia-titania catalysts. Up to a critical V{sub 2}O{sub 5} loading (between 10 and 12wt%), all the vanadium was highly dispersed in the form of monomeric vanadyl and polymeric vanadate species, whereas for higher loadings V{sub 2}O{sub 5} crystallites also formed. Most of the vanadium species (80-90%) were accessible to reduction by H{sub 2}. The catalytic properties of these materials were evaluated in the selective catalytic reduction of NO by NH{sub 3}. The estimated turnover frequency 'TOF' at 473K (mole of NO converted per mole of V per hour) went through a maximum value (16.6h{sup -1}) at a V loading of 8wt%, corresponding to an estimated surface vanadia loading of about 10{mu}molm{sup -2}. The N{sub 2}O selectivity increased upon V loading as expected. A compromise between activity and high N{sub 2} selectivity (98% at 623K) could be found with the material containing 6wt% V{sub 2}O{sub 5}. (author)

  18. Surface structure determinations of ordered sulfur overlayers on Mo(100) and Re(0001) by low-energy electron diffraction intensity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jentz, D.W.

    1992-11-01

    A newly developed method for surface structure determination, tensor LEED, combined with automated search was used to analyze the structures. The ordered structures of S on Mo(100) which were studied formed a c(2 {times} 2), c(4 {times} 2), and p(2 {times} l) periodicities at coverages of 0.5, 0.75, 1.0 ML (monolayers, of one sulfur atom per one molybdenum atom) respectively. A MO{sub 2}S-like overlayer, which formed at coverages greater than 1.0 ML, is also discussed. Calculations for the c(2 {times} 2) structure gave a best fit geometry with S adsorbed in a four-fold symmetric hollow site and the second layer buckled by 0.09{Angstrom}. The S-Mo bond length is 2.45{Angstrom} and the Pendry R-factor is 0.21. Preliminary calculations for the c(4 {times} 2) structure did not yield an acceptable fit. The three models tried are discussed. Calculations for p(2 {times} l) data did not yield an acceptable geometry either. The types of models that were tried are discussed. Implications of this analysis are discussed along with results of a scanning tunneling microscopy (STM) investigation. The ordered structures on the RE(0001) surface studied have p(2 {times} 2) and (2{radical}3 {times} 2{radical}3)R30{degree} periodicities and occurred at S coverages of 0.25 and 0.5 ML respectively. Best fit structure for p(2 {times} 2) structure has S adsorbed in a three-fold hollow hcp site and exhibits a buckling of the first and second Re layers. The first layer is buckled by 0.05{Angstrom} and the second layer is buckled by 0.06{Angstrom}. Re-S bond length is 2.32{Angstrom} and Pendry R-factor is 0.21. Preliminary results of dynamical LEED investigation of (2{radical}3 {times} 2{radical}3)R30{degree} structure show reasonable agreement with a model with a 6-S atom basis.

  19. New vanadia-mesoporous catalysts for the oxidation of SO{sub 2} in diluted gases

    Energy Technology Data Exchange (ETDEWEB)

    Paun, C.; Parvulescu, V.; Parvulescu, V.I. [Department of Catalysis, Faculty of Chemistry, University of Bucharest, B-dul Regina, Elisabeta 4-12, Bucharest 70346 (Romania); Massiot, Ph.; Centeno, M.A. [Instituto de Ciencia de Materiales de Sevilla, Universidad de Sevilla-CSIC, Avenida Americo Vespucio s/n, 41092 Sevilla (Spain); Grange, P. [Universite Catholique de Louvain, Croix du Sud 2/17, 1348 LLN (Belgium)

    2004-07-15

    Mesoporous SO{sub 2} oxidation catalysts were prepared by impregnation of a sol-gel prepared vanadia-silica support with various amounts of cesium sulfate or mixtures of alkaline sulfate species (Na or K). The resulting catalysts were characterized by adsorption-desorption isotherms of nitrogen at 77K, in situ evolution of crystallinity by X-ray diffraction, NH{sub 3}-DRIFT, XPS, transmission electron microscopy, dispersive X-ray analysis, and X-ray fluorescence spectrometry. Catalytic tests in oxidation of SO{sub 2} in diluted gases (1vol.%) showed that these systems were very active. A dependence on the alkaline metal loading was also evidenced.

  20. Overlay networks toward information networking

    CERN Document Server

    Tarkoma, Sasu

    2010-01-01

    With their ability to solve problems in massive information distribution and processing, while keeping scaling costs low, overlay systems represent a rapidly growing area of R&D with important implications for the evolution of Internet architecture. Inspired by the author's articles on content based routing, Overlay Networks: Toward Information Networking provides a complete introduction to overlay networks. Examining what they are and what kind of structures they require, the text covers the key structures, protocols, and algorithms used in overlay networks. It reviews the current state of th

  1. Influence of reaction products of K-getter fuel additives on commercial vanadia-based SCR catalysts

    DEFF Research Database (Denmark)

    Castellino, Francesco; Jensen, Anker Degn; Johnsson, Jan Erik

    2009-01-01

    Commercial vanadia-based full-length monoliths have been exposed to aerosols formed by injection of K3PO4 (dissolved in water) in a hot flue gas (T > 850 °C) from a natural gas burner. Such aerosols may form when burning fuels with high K- and P-content, or when P-compounds are mixed with biomass...

  2. Catalytic Performance of Zeolite-Supported Vanadia in the Aerobic Oxidation of 5-hydroxymethylfurfural to 2,5- diformylfuran

    DEFF Research Database (Denmark)

    Sádaba, Irantzu; Gorbanev, Yury; Kegnæs, Søren;

    2013-01-01

    on the four different zeolite supports H-beta, H-Y, H-mordenite, and H-ZSM-5 with 1–10 wt% vanadia loading were prepared and characterized by nitrogen physisorption, X-ray powder diffraction, scanning electron  microscopy, ammonia temperature-programmed desorption, Raman spectroscopy and UV/Vis...

  3. The Role of Vanadia for the Selective Oxidation of Benzyl Alcohol over Heteropolymolybdate Supported on Alumina

    Institute of Scientific and Technical Information of China (English)

    Pasupulet Siva Nageswara RAO; Kasanneni Tirumala Venkateswara RAO; Potharaju S. SAI PRASAD; Nakka LINGAIAH

    2011-01-01

    A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption,X-ray diffraction,temperature-programmed reduction,in situ laser Raman spectroscopy,UV-Vis diffused reflectance spectroscopy,scanning electron microscopy,and temperature-programmed desorption of NH3 techniques.Their catalytic activities were evaluated for the vapor phase aerobic oxidation of benzyl alcohol.The catalysts exhibited high catalytic activity and the conversion of benzyl alcohol depended on the vanadia content while the catalyst with 15 wt% V2O5 content showed optimum activity.The characterization results suggest the presence of well-dispersed V2O5 and partially disintegrated Keggin ions of MPA on the support.In situ Raman studies showed a reduced Mo(IV) species when the catalysts were calcined at high temperatures.The high oxidation activity of the catalysts is related to the synergistic effect between MPA and V2O5.

  4. He atom-surface scattering: Surface dynamics of insulators, overlayers and crystal growth. Progress report, May 1, 1991--April 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    Investigations in this laboratory have focused on the surface structure and dynamics of ionic insulators and on epitaxial growth onto alkali halide crystals. In the later the homoepitaxial growth of NaCl/NaCl(001) and the heteroepitaxial growth of KBr/NaCl(001), NaCl/KBr(001) and KBr/RbCl(001) have been studied by monitoring the specular He scattering as a function of the coverage and by measuring the angular and energy distributions of the scattered He atoms. These data provide information on the surface structure, defect densities, island sizes and surface strain during the layer-by-layer growth. The temperature dependence of these measurements also provides information on the mobilities of the admolecules. He atom scattering is unique among surface probes because the low-energy, inert atoms are sensitive only to the electronic structure of the topmost surface layer and are equally applicable to all crystalline materials. It is proposed for the next year to exploit further the variety of combinations possible with the alkali halides in order to carry out a definitive study of epitaxial growth in the ionic insulators. The work completed so far, including measurements of the Bragg diffraction and surface dispersion at various stages of growth, appears to be exceptionally rich in detail, which is particularly promising for theoretical modeling. In addition, because epitaxial growth conditions over a wide range of lattice mismatches is possible with these materials, size effects in growth processes can be explored in great depth. Further, as some of the alkali halides have the CsCl structure instead of the NaCl structure, we can investigate the effects of the heteroepitaxy with materials having different lattice preferences. Finally, by using co-deposition of different alkali halides, one can investigate the formation and stability of alloys and even alkali halide superlattices.

  5. Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ogletree, D.F.

    1986-11-01

    LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2..sqrt..3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (..sqrt..3 x ..sqrt..3) reconstruction on the (111) face of the ..cap alpha..-CuAl alloy has been determined.

  6. MICROSTRUCTURES AND OXIDATION RESISTANCE OF Fe3Al WELD OVERLAY

    Institute of Scientific and Technical Information of China (English)

    X.G.Min; X.Q.Yu; Y.S.Sun; J.R.Sun

    2001-01-01

    Using the Fe3Al electrode through manual arc surfacing (MAS),Fe3Al coatings havebeen deposited on the stainless steel substrate.The microstructures,hardness andoxidation resistance of the weld overlay have been investigated.The results show thatcrack-free overlays can be obtained when pre-heating of the substrate at 500℃ andpostweld heat treatment at 700℃ were used.Elements of Al,Cr,Ni etc.transferredbetween the substrate and the overlay,but this does not influence the microhardnessof the substrate and the Fe3Al overlay.Oxidation tests show that the Fe3Al overlayshave excellent oxidation resistance in comparison with the stainless steel substrate at800℃ and 900℃.

  7. Towards Social Profile Based Overlays

    CERN Document Server

    Wolinsky, David Isaac; Boykin, P Oscar; Figueiredo, Renato

    2010-01-01

    Online social networking has quickly become one of the most common activities of Internet users. As social networks evolve, they encourage users to share more information, requiring the users, in turn, to place more trust into social networks. Peer-to-peer (P2P) overlays provide an environment that can return ownership of information, trust, and control to the users, away from centralized third-party social networks. In this paper, we present a novel concept, social profile overlays, which enable users to share their profile only with trusted peers in a scalable, reliable, and private manner. Each user's profile consists of a unique private, secure overlay, where members of that overlay have a friendship with the overlay owner. Profile data is made available without regard to the online state of the profile owner through the use of the profile overlay's distributed data store. Privacy and security are enforced through the use of a public key infrastructure (PKI), where the role of certificate authority (CA) i...

  8. Perceived effects of coloured overlays on reading material in persons with albinism

    Directory of Open Access Journals (Sweden)

    N. T. Makgaba

    2008-01-01

    Full Text Available Persons with albinism often complain of glare when reading. They may therefore benefit from coloured filter overlays just as they benefit from tinted lenses. The purpose of this study was to assess the effectof coloured overlays on print perception in persons with oculocutaneous albinism (OCA.   Fifty subjects were included in this study, their ages ranged from 12 to 31 years with a mean of 16.12 years (SD = ± 4.56 years.  Following refraction and subsequent compensation for refractive errors, subjective perception of print was examined with the subject looking at the Wilkins® reading rate test chart with and without colored filter overlay/s.  The subjects were asked to respond to questions previously used in a questionnaire by Wilkins (2001. The percentage frequencies of positive (beneficial responses were used to decide whether or not a particular overlay would enhance reading performance.  McNemar’s test was used to establish significant differences between responses to questions without and with overlays. All single overlays gave greater percentages of positive responses (92.0-97.2% than without overlay (85.2%.  The single overlay that provided the highest positive responses was blue (97.2% and the least was purple (92.0%. All double overlays, except grey/grey (82.0% gave greater positive responses than without overlay (85.2%. Aqua/blue gave the greatest positive responses (possible benefits (97.2%, followed by rose/rose (96.8%.  Comparing the responses without overlay with single and double overlays, the difference in responses to the five questions was only significant (p < 0.05 with regard to brightness of the surface. The results suggest that overlays provided a more glare-free reading surface than without an overlay. It was, therefore concluded that the best advantage of the coloured overlays was in glare reduction.  Although this study showed that there were more subjects who preferred single blue and aqua/blue double

  9. A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Khaliullin, Rustam Z.; Bell, Alexis T.

    2002-09-05

    Density functional theory was used to investigate the mechanism and kinetics of methanol oxidation to formaldehyde over vanadia supported on silica, titania, and zirconia. The catalytically active site was modeled as an isolated VO{sub 4} unit attached to the support. The calculated geometry and vibrational frequencies of the active site are in good agreement with experimental measurements both for model compounds and oxide-supported vanadia. Methanol adsorption is found to occur preferentially with the rupture of a V-O-M bond (M = Si, Ti, Zr) and with preferential attachment of a methoxy group to V. The vibrational frequencies of the methoxy group are in good agreement with those observed experimentally as are the calculated isobars. The formation of formaldehyde is assumed to occur via the transfer of an H atom of a methoxy group to the O atom of the V=O group. The activation energy for this process is found to be in the range of 199-214 kJ/mol and apparent activation energies for the overall oxidation of methanol to formaldehyde are predicted to lie in the range of 112-123 kJ/mol, which is significantly higher than that found experimentally. Moreover, the predicted turnover frequency (TOF) for methanol oxidation is found to be essentially independent of support composition, whereas experiments show that the TOF is 10{sup 3} greater for titania- and zirconia-supported vanadia than for silica-supported vanadia. Based on these findings, it is proposed that the formation of formaldehyde from methoxy groups may require pairs of adjacent VO{sub 4} groups or V{sub 2}O{sub 7} dimer structures.

  10. Respiratory motion compensated overlay of surface models from cardiac MR on interventional x-ray fluoroscopy for guidance of cardiac resynchronization therapy procedures

    Science.gov (United States)

    Manzke, R.; Bornstedt, A.; Lutz, A.; Schenderlein, M.; Hombach, V.; Binner, L.; Rasche, V.

    2010-02-01

    Various multi-center trials have shown that cardiac resynchronization therapy (CRT) is an effective procedure for patients with end-stage drug invariable heart failure (HF). Despite the encouraging results of CRT, at least 30% of patients do not respond to the treatment. Detailed knowledge of the cardiac anatomy (coronary venous tree, left ventricle), functional parameters (i.e. ventricular synchronicity) is supposed to improve CRT patient selection and interventional lead placement for reduction of the number of non-responders. As a pre-interventional imaging modality, cardiac magnetic resonance (CMR) imaging has the potential to provide all relevant information. With functional information from CMR optimal implantation target sites may be better identified. Pre-operative CMR could also help to determine whether useful vein target segments are available for lead placement. Fused with X-ray, the mainstay interventional modality, improved interventional guidance for lead-placement could further help to increase procedure outcome. In this contribution, we present novel and practicable methods for a) pre-operative functional and anatomical imaging of relevant cardiac structures to CRT using CMR, b) 2D-3D registration of CMR anatomy and functional meshes with X-ray vein angiograms and c) real-time capable breathing motion compensation for improved fluoroscopy mesh overlay during the intervention based on right ventricular pacer lead tracking. With these methods, enhanced interventional guidance for left ventricular lead placement is provided.

  11. 不同高度全口覆盖义齿短冠基牙根面临床观察%Clinical observation of different short crown root surface height complete overlay denture base

    Institute of Scientific and Technical Information of China (English)

    田丽; 杨军成

    2012-01-01

    目的探讨全口覆盖义齿基牙根面不同高度牙龈病的发病率.方法随机选择30例口内有多个残根残冠的中老年患者,选择符合条件的残根或残冠共126个基牙经治疗后.将残根残冠根面预备平整,上颌残根根面平齐龈缘,下颌残根根面高出龈缘1-2mm.根管口及根面均采用光固化树脂充填,然后进行常规全口义齿修复.观察两种不同方法牙龈炎的发病率.结果30例全口覆盖义齿患者中平齐龈缘的残根龈炎发病率较高.结论选择全口覆盖义齿修复方式时,短冠基牙残根根面高度预备最好高出龈缘1-2mm,可以预防牙周炎的发生.%Objective : Study of complete overdenture based on root surface in different height of gingival disease incidence rate Methods: In 30 randomly selected patients with a number of residual root and crown in the elderly patients, Selection of eligible residual roots or crowns in a total of 126 abutment teeth after the treatment, The residual crown and root to root surface preparation leveling, maxillary residual root surface flush gingival margin, Mandibular residual root surface above the gingival margin 1-2mm, Root canal orifice and root surface using light curing resin filling, then the conventional complete denture restoration. Observe the effect of two different methods the incidence of gingivitis. Results:In 30 patients with complete overlay denture patients with gingival margin in a higher incidence of residual root gingivitis. Conclusion: Selection of overlay denture repairing mode, Short crown abutment teeth residual root surface height above the gingival margin 1-2mm is the better mode, it can prevent the onset of periodontitis.

  12. Ceria-Vanadia/Silica-Catalyzed Cascade for C-C and C-O Bond Activation: Green One-Pot Synthesis of 2-Amino-3-cyano-4H-pyrans.

    Science.gov (United States)

    Maddila, Surya Narayana; Maddila, Suresh; van Zyl, Werner E; Jonnalagadda, Sreekantha B

    2016-02-01

    We designed a ceria-vanadia/silica (Ce-V/SiO2) heterogeneous catalyst and used it for the green and efficient synthesis of 2-amino-3-cyano-4H-pyran derivatives. The green reaction was a multicomponent one-pot condensation of 5,5-dimethylcyclohexane-1,3-dione, aromatic aldehyde, and malononitrile in an eco-compatible solvent (ethanol). The catalyst was synthesized and fully characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The reported procedure offers a number of advantages including decreased reaction times, mild conditions, high yields, operational simplicity, and environmentally benign and simple work-up procedures. Furthermore, the catalyst is economical, fully recyclable, and reusable for over five runs while preserving its high activity. The synthesized 2-amino-3-cyano-4H-pyran products can later be used for pharmaceutical purposes.

  13. COMPARISON OF NORMAL SELFISH OVERLAY NETWORK AND SELFISH OVERLAY NETWORK WITH DEPLOYMENT OF OVERLAY NODES USING FUZZY LOGIC

    OpenAIRE

    S.Prayla Shyry; Ramachandran, V.

    2011-01-01

    Selfish overlay routing is the technique whereby the sender of the packet can specify the route that the packet should take through the network. Selfish overlay routing allow end users to select routes in an egocentic fashion to optimize their own performance without considering the system wide criteria which in turn cause performance degradation .The main concept behind the selfish overlay network is whenever there is a link failure the overlay nodes in the network will route the packet to t...

  14. Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays

    Science.gov (United States)

    Dubois, Cameron; Ramseyer, Chris

    2010-10-01

    The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

  15. Culture systems: mineral oil overlay.

    Science.gov (United States)

    Morbeck, Dean E; Leonard, Phoebe H

    2012-01-01

    Mineral oil overlay microdrop is commonly used during in vitro fertilization (IVF) procedures. Though mineral oil appears homogeneous, it is an undefined product that can vary in quality. Here, we describe the history, chemistry, processing, and optimal use of mineral oil for IVF and embryo culture.

  16. Pitting corrosion resistance and bond strength of stainless steel overlay by friction surfacing on high strength low alloy steel

    Directory of Open Access Journals (Sweden)

    Amit Kumar Singh

    2015-09-01

    Full Text Available Surface modification is essential for improving the service properties of components. Cladding is one of the most widely employed methods of surface modification. Friction surfacing is a candidate process for depositing the corrosion resistant coatings. Being a solid state process, it offers several advantages over conventional fusion based surfacing process. The aim of this work is to identify the relationship between the input variables and the process response and develop the predictive models that can be used in the design of new friction surfacing applications. In the current work, austenitic stainless steel AISI 304 was friction surfaced on high strength low alloy steel substrate. Friction surfacing parameters, such as mechtrode rotational speed, feed rate of substrate and axial force on mechtrode, play a major role in determining the pitting corrosion resistance and bond strength of friction surfaced coatings. Friction surfaced coating and base metal were tested for pitting corrosion by potentio-dynamic polarization technique. Coating microstructure was characterized using optical microscopy, scanning electron microscopy and X-ray diffraction. Coatings in the as deposited condition exhibited strain-induced martensite in austenitic matrix. Pitting resistance of surfaced coatings was found to be much lower than that of mechtrode material and superior to that of substrate. A central composite design with three factors (mechtrode rotational speed, substrate traverse speed, axial load on mechtrode and five levels was chosen to minimize the number of experimental conditions. Response surface methodology was used to develop the model. In the present work, an attempt has been made to develop a mathematical model to predict the pitting corrosion resistance and bond strength by incorporating the friction surfacing process parameters.

  17. Advanced overlay analysis through design based metrology

    Science.gov (United States)

    Ji, Sunkeun; Yoo, Gyun; Jo, Gyoyeon; Kang, Hyunwoo; Park, Minwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Yim, Donggyu; Maruyama, Kotaro; Park, Byungjun; Yamamoto, Masahiro

    2015-03-01

    As design rule shrink, overlay has been critical factor for semiconductor manufacturing. However, the overlay error which is determined by a conventional measurement with an overlay mark based on IBO and DBO often does not represent the physical placement error in the cell area. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion caused by etching or CMP also can be a source of the mismatch. In 2014, we have demonstrated that method of overlay measurement in the cell area by using DBM (Design Based Metrology) tool has more accurate overlay value than conventional method by using an overlay mark. We have verified the reproducibility by measuring repeatable patterns in the cell area, and also demonstrated the reliability by comparing with CD-SEM data. We have focused overlay mismatching between overlay mark and cell area until now, further more we have concerned with the cell area having different pattern density and etch loading. There appears a phenomenon which has different overlay values on the cells with diverse patterning environment. In this paper, the overlay error was investigated from cell edge to center. For this experiment, we have verified several critical layers in DRAM by using improved(Better resolution and speed) DBM tool, NGR3520.

  18. Overlay networking:applications and research challenges

    Institute of Scientific and Technical Information of China (English)

    LU Jun-xiu; SHAN Xiu-ming; REN Yong

    2004-01-01

    Overlay networking is one of the perspective solutions to today's Intemet challenges. At basic service level, overlay networks can serve as a supplement and enhancement of existing services, such as routing and addressing. At high application level, overlay networks can be used for applications, which are difficult to deploy in existing IP architecture with some specific reasons, e.g., they need high-level information, which is hard to obtain by underlying layers. To address the heterogeneity of today's Internet, overlay networks provide ways to service availability and desirable performance while retaining scalability. In contrast to changing the existing network layer, overlay networks allow bootstrapping, which is most important in the development of Internet infrastructure. Various applications of overlay networking are clarified in this paper. Research challenges including routing and searching in overlay networking are also identified.

  19. Water Resources Overlays Users Guide

    Science.gov (United States)

    1990-12-01

    ORGANIZATION REPORT NUMBER Water Resources Division TEC-SR3 U.S. Geological Survey Reston, Virginia 9. SPONSORING/ MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10...SPONSORING/ MONITORING AGENCY REPORT NUMBER U.S. Army Topographic Engineering Center Fort Belvoir, Virginia 22060-5546 11. SUPPLEMENTARY NOTES...overlay, nor is there any other apparent source of water. However, the ranks and towers could be provided warer from an unmapped pipeline, or could be

  20. Recommendations for the repair, the lining or the strengthening of concrete slabs or pavements with bonded cement-based material overlays

    OpenAIRE

    Courard, Luc; Bissonnette, Benoît; Beushausen, Hans; Fowler,David; Trevino, Manuel; Alex, Vaysburd; Johan, Silfwerbrand

    2013-01-01

    The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM technical committee TC 193 RLS Bonded cement-based material overlays for the repair, the lining or the strengthening of slabs and pavements. The objective is to lay out all the practical aspects to be considered in the design of concrete overlays: bonded concrete overlay process, assessment of the existing structure, surface preparation, overlay materials, design methods, construc...

  1. Overlay metrology for double patterning processes

    Science.gov (United States)

    Leray, Philippe; Cheng, Shaunee; Laidler, David; Kandel, Daniel; Adel, Mike; Dinu, Berta; Polli, Marco; Vasconi, Mauro; Salski, Bartlomiej

    2009-03-01

    The double patterning (DPT) process is foreseen by the industry to be the main solution for the 32 nm technology node and even beyond. Meanwhile process compatibility has to be maintained and the performance of overlay metrology has to improve. To achieve this for Image Based Overlay (IBO), usually the optics of overlay tools are improved. It was also demonstrated that these requirements are achievable with a Diffraction Based Overlay (DBO) technique named SCOLTM [1]. In addition, we believe that overlay measurements with respect to a reference grid are required to achieve the required overlay control [2]. This induces at least a three-fold increase in the number of measurements (2 for double patterned layers to the reference grid and 1 between the double patterned layers). The requirements of process compatibility, enhanced performance and large number of measurements make the choice of overlay metrology for DPT very challenging. In this work we use different flavors of the standard overlay metrology technique (IBO) as well as the new technique (SCOL) to address these three requirements. The compatibility of the corresponding overlay targets with double patterning processes (Litho-Etch-Litho-Etch (LELE); Litho-Freeze-Litho-Etch (LFLE), Spacer defined) is tested. The process impact on different target types is discussed (CD bias LELE, Contrast for LFLE). We compare the standard imaging overlay metrology with non-standard imaging techniques dedicated to double patterning processes (multilayer imaging targets allowing one overlay target instead of three, very small imaging targets). In addition to standard designs already discussed [1], we investigate SCOL target designs specific to double patterning processes. The feedback to the scanner is determined using the different techniques. The final overlay results obtained are compared accordingly. We conclude with the pros and cons of each technique and suggest the optimal metrology strategy for overlay control in double

  2. Two-step-wise interpretation of highly asymmetric, grazing angle (e,2e) on solids: A real momentum spectroscopy for surfaces and overlayers

    Science.gov (United States)

    Liscio, A.; Ruocco, A.; Stefani, G.; Iacobucci, S.

    2008-02-01

    This paper deals with the mechanism of grazing incidence (e,2e) events from surfaces. Two different approaches are considered. In both cases, elastic scattering with the crystal lattice assists the inelastic collision; these two steps are coupled either coherently or incoherently. Experimental evidence is given that the “coherent” approach reproduces better the cross section dependence on momentum transfer in the specific case of asymmetric kinematics at moderate electron energies. This model has allowed us to map out the band dispersion of the outermost valence states of highly oriented pyrolytic graphite and to measure the momentum distribution of π -electron states without invoking the contribution of reciprocal lattice vectors in the momentum conservation. Agreement between theory and experiment is satisfactory, though the presence of events where crystal momentum is reconstructed cannot be ruled out. These results, obtained with a significant reduction of the experiment duration by an implemented apparatus, show that reflection (e,2e) can be used to build up a momentum spectroscopy with high surface sensitivity.

  3. Silver overlayer-modified surface-enhanced Raman scattering-active gold substrates for potential applications in trace detection of biochemical species.

    Science.gov (United States)

    Ou, Keng-Liang; Hsu, Ting-Chu; Liu, Yu-Chuan; Yang, Kuang-Hsuan; Tsai, Hui-Yen

    2014-01-02

    Because Ag and Au nanoparticles (NPs) possess well-defined localized surface plasmon resonance (LSPR) they are popularly employed in the studies of surface-enhanced Raman scattering (SERS). As shown in the literature and in our previous studies, the advantage of SERS-active Ag NPs is their higher SERS enhancement over Au NPs. On the other hand, the disadvantage of SERS-active Ag NPs compared to Au NPs is their serious decay of SERS enhancement in ambient laboratory air. In this work, we develop a new strategy for preparing highly SERS-active Ag NPs deposited on a roughened Au substrate. This strategy is derived from the modification of electrochemical underpotential deposition (UPD) of metals. The coverage of Ag NPs on the roughened Au substrate can be as high as 0.95. Experimental results indicate that the SERS of Rhodamine 6G (R6G) observed on this developed substrate exhibits a higher intensity by ca. 50-fold of magnitude, as compared with that of R6G observed on the substrate without the deposition of Ag NPs. The limit of detection (LOD) for R6G measured on this substrate is markedly reduced to 2×10(-15)M. Moreover, aging of SERS effect observed on this developed substrate is significantly depressed, as compared with that observed on a generally prepared SERS-active Ag substrate. These aging tests were performed in an atmosphere of 50% relative humidity (RH) and 20% (v/v) O2 at 30°C for 60 day. Also, the developed SERS-active substrate enables it practically applicable in the trace detection of monosodium urate (MSU)-containing solution in gouty arthritis without a further purification process.

  4. Analysis Of Overlay Distortion Patterns

    Science.gov (United States)

    Armitage, John D.; Kirk, Joseph P.

    1988-01-01

    A comprehensive geometrical approach is presented for the least-squares analysis of overlay distortion patterns into useful, physically meaningful systematic distortion subpatterns and an essentially non-systematic residue. A scheme of generally useful distortion sub-patterns is presented in graphic and algorithmic form; some of these sub-patterns are additions to those already in widespread use. A graphic and geometric approach is emphasized rather than an algebraic or statistical approach, and an example illustrates the value in utilizing the pattern-detecting ability of the eye-brain system. The conditions are described under which different distortion sub-patterns may interact, possibly leading to misleading or erroneous conclusions about the types and amounts of different distortions present. Examples of typical interaction situations are given, and recommendations are made for analytic procedures to avoid misinterpretation. It is noted that the lower-order distortion patterns preserve straight-line linearity, but that higher-order distortion may result in straight lines becoming curved. The principle of least-squares analysis is outlined and a simple polynomial data-fitting example is used to illustrate the method. Algorithms are presented for least-squares distortion analysis of overlay patterns, and an APL2 program is given to show how this may easily be implemented on a digital computer. The appendix extends the treatment to cases where small-angle approximation is not permissible.

  5. KMPlayer出现Overlay Mixer错误

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    问:我使用KMPlayer播放器播放电影时,经常出现Overlay Mixer错误,有时候不出现,我将Overlay Mixer插件删除了,但它还会自动加载,继续出错。请问这是什么原因?

  6. LMS filters for cellular CDMA overlay

    OpenAIRE

    1996-01-01

    This paper extends and complements previous research we have performed on the performance of nonadaptive narrowband suppression filters when used in cellular CDMA overlay situations. In this paper, an adaptive LMS filter is applied to cellular CDMA overlay situations in order to reject narrowband interference.

  7. Overlay accuracy with respect to device scaling

    Science.gov (United States)

    Leray, Philippe; Laidler, David; Cheng, Shaunee

    2012-03-01

    Overlay metrology performance is usually reported as repeatability, matching between tools or optics aberrations distorting the measurement (Tool induced shift or TIS). Over the last few years, improvement of these metrics by the tool suppliers has been impressive. But, what about accuracy? Using different target types, we have already reported small differences in the mean value as well as fingerprint [1]. These differences make the correctables questionable. Which target is correct and therefore which translation, scaling etc. values should be fed back to the scanner? In this paper we investigate the sources of these differences, using several approaches. First, we measure the response of different targets to offsets programmed in a test vehicle. Second, we check the response of the same overlay targets to overlay errors programmed into the scanner. We compare overlay target designs; what is the contribution of the size of the features that make up the target? We use different overlay measurement techniques; is DBO (Diffraction Based Overlay) more accurate than IBO (Image Based Overlay)? We measure overlay on several stacks; what is the stack contribution to inaccuracy? In conclusion, we offer an explanation for the observed differences and propose a solution to reduce them.

  8. Study on the rupture characteristics of the overlaying soil with soft interlayer due to fault bedrock dislocation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lei; LI Xiao-jun; HUO Da

    2006-01-01

    In this paper, the rupture characteristics of the overlaying soil with soft interlayer were studied by plane-strain finite element method. From the results, it can be shown that the existence of soft layer separates rupture process of the overlaying soil into two phases. The depth of a buried soft interlayer will influence the rupture process and the rupture range of the overlaying soil. The deeply buried soft interlayer would bring about a wider range of surface failure. In addition, the thickness of the soft layer also has effect on the rupture process and rupture range of the overlaying soil.

  9. CFDP for Interplanetary Overlay Network

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for Interplanetary Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.

  10. The Assessment of Distortion in Neurosurgical Image Overlay Projection.

    Science.gov (United States)

    Vakharia, Nilesh N; Paraskevopoulos, Dimitris; Lang, Jozsef; Vakharia, Vejay N

    2016-02-01

    Numerous studies have demonstrated the superiority of neuronavigation during neurosurgical procedures compared to non-neuronavigation-based procedures. Limitations to neuronavigation systems include the need for the surgeons to avert their gaze from the surgical field and the cost of the systems, especially for hospitals in developing countries. Overlay projection of imaging directly onto the patient allows localization of intracranial structures. A previous study using overlay projection demonstrated the accuracy of image coregistration for a lesion in the temporal region but did not assess image distortion when projecting onto other anatomical locations. Our aim is to quantify this distortion and establish which regions of the skull would be most suitable for overlay projection. Using the difference in size of a square grid when projected onto an anatomically accurate model skull and a flat surface, from the same distance, we were able to calculate the degree of image distortion when projecting onto the skull from the anterior, posterior, superior, and lateral aspects. Measuring the size of a square when projected onto a flat surface from different distances allowed us to model change in lesion size when projecting a deep structure onto the skull surface. Using 2 mm as the upper limit for distortion, our results show that images can be accurately projected onto the majority (81.4%) of the surface of the skull. Our results support the use of image overlay projection in regions with ≤2 mm distortion to assist with localization of intracranial lesions at a fraction of the cost of existing methods. © The Author(s) 2015.

  11. Device overlay method for high volume manufacturing

    Science.gov (United States)

    Lee, Honggoo; Han, Sangjun; Kim, Youngsik; Kim, Myoungsoo; Heo, Hoyoung; Jeon, Sanghuck; Choi, DongSub; Nabeth, Jeremy; Brinster, Irina; Pierson, Bill; Robinson, John C.

    2016-03-01

    Advancing technology nodes with smaller process margins require improved photolithography overlay control. Overlay control at develop inspection (DI) based on optical metrology targets is well established in semiconductor manufacturing. Advances in target design and metrology technology have enabled significant improvements in overlay precision and accuracy. One approach to represent in-die on-device as-etched overlay is to measure at final inspection (FI) with a scanning electron microscope (SEM). Disadvantages to this approach include inability to rework, limited layer coverage due to lack of transparency, and higher cost of ownership (CoO). A hybrid approach is investigated in this report whereby infrequent DI/FI bias is characterized and the results are used to compensate the frequent DI overlay results. The bias characterization is done on an infrequent basis, either based on time or triggered from change points. On a per-device and per-layer basis, the optical target overlay at DI is compared with SEM on-device overlay at FI. The bias characterization results are validated and tracked for use in compensating the DI APC controller. Results of the DI/FI bias characterization and sources of variation are presented, as well as the impact on the DI correctables feeding the APC system. Implementation details in a high volume manufacturing (HVM) wafer fab will be reviewed. Finally future directions of the investigation will be discussed.

  12. Overlay considerations for 300-mm lithography

    Science.gov (United States)

    Mono, Tobias; Schroeder, Uwe P.; Nees, Dieter; Palitzsch, Katrin; Koestler, Wolfram; Bruch, Jens; Kramp, Sirko; Veldkamp, Markus; Schuster, Ralf

    2003-05-01

    Generally, the potential impact of systematical overlay errors on 300mm wafers is much larger than on 200mm wafers. Process problems which are merely identified as minor edge yield detractors on 200mm wafers, can evolve as major roadblocks for 300mm lithography. Therefore, it is commonly believed that achieving product overlay specifications on 300mm wafers is much more difficult than on 200mm wafers. Based on recent results on high volume 300mm DRAM manufacturing, it is shown that in reality this assumption does not hold. By optimizing the process, overlay results can be achieved which are comparable to the 200mm reference process. However, the influence of non-lithographic processes on the overlay performance becomes much more critical. Based on examples for specific overlay signatures, the influence of several processes on the overlay characteristics of 300mm wafers is demonstrated. Thus, process setup and process changes need to be analyzed monitored much more carefully. Any process variations affecting wafer related overlay have to be observed carefully. Fast reaction times are critical to avoid major yield loss. As the semiconductor industry converts to 300mm technology, lithographers have to focus more than ever on process integration aspects.

  13. The effect of individually-induced processes on image-based overlay and diffraction-based overlay

    Science.gov (United States)

    Oh, SeungHwa; Lee, Jeongjin; Lee, Seungyoon; Hwang, Chan; Choi, Gilheyun; Kang, Ho-Kyu; Jung, EunSeung

    2014-04-01

    In this paper, set of wafers with separated processes was prepared and overlay measurement result was compared in two methods; IBO and DBO. Based on the experimental result, theoretical approach of relationship between overlay mark deformation and overlay variation is presented. Moreover, overlay reading simulation was used in verification and prediction of overlay variation due to deformation of overlay mark caused by induced processes. Through this study, understanding of individual process effects on overlay measurement error is given. Additionally, guideline of selecting proper overlay measurement scheme for specific layer is presented.

  14. Diffraction based overlay re-assessed

    Science.gov (United States)

    Leray, Philippe; Laidler, David; D'havé, Koen; Cheng, Shaunee

    2011-03-01

    In recent years, numerous authors have reported the advantages of Diffraction Based Overlay (DBO) over Image Based Overlay (IBO), mainly by comparison of metrology figures of merit such as TIS and TMU. Some have even gone as far as to say that DBO is the only viable overlay metrology technique for advanced technology nodes; 22nm and beyond. Typically the only reported drawback of DBO is the size of the required targets. This severely limits its effective use, when all critical layers of a product, including double patterned layers need to be measured, and in-die overlay measurements are required. In this paper we ask whether target size is the only limitation to the adoption of DBO for overlay characterization and control, or are there other metrics, which need to be considered. For example, overlay accuracy with respect to scanner baseline or on-product process overlay control? In this work, we critically re-assess the strengths and weaknesses of DBO for the applications of scanner baseline and on-product process layer overlay control. A comprehensive comparison is made to IBO. For on product process layer control we compare the performance on critical process layers; Gate, Contact and Metal. In particularly we focus on the response of the scanner to the corrections determined by each metrology technique for each process layer, as a measure of the accuracy. Our results show that to characterize an overlay metrology technique that is suitable for use in advanced technology nodes requires much more than just evaluating the conventional metrology metrics of TIS and TMU.

  15. Ion beam mixing of titanium overlayers with hydroxyapaptite substrates

    Energy Technology Data Exchange (ETDEWEB)

    Levine, T.E. [Cornell Univ., Ithaca, NY (United States). Dept. of Materials Science and Engineering; Nastasi, M. [Los Alamos National Lab., NM (United States); Alford, T.L.; Suchicital, C.; Russell, S.; Luptak, K.; Pizziconi, V.; Mayer, J.W. [Arizona State Univ., Tempe, AZ (United States)

    1995-01-01

    The mixing of titanium overlayers with hydroxyapatite (HA) substrates via ion irradiation has been demonstrated. Analysis via secondary ion mass spectroscopy (SIMS) indicates an interfacial broadening of titanium and calcium of the implanted sample compared to that of the unimplanted sample. Attendant to the observed ion beam mixing of titanium into the HA, the oxygen signal of the titanium overlayer increases as a result of ion irradiation. It is supposed that this change is evident of diffusion through the metal layer and possibly from titania formation at the free surface and perovskite formation at the film/substrate interface. This possibility is consistent with thermodynamic predictions. Additionally, the force required to separate the film from the substrate increased as a result of ion irradiation, validating the continued study of ion beam processing of Ti/HA systems towards the improvement of long term fixation of implant devices.

  16. Qmerit-calibrated overlay to improve overlay accuracy and device performance

    Science.gov (United States)

    Ullah, Md Zakir; Jazim, Mohamed Fazly Mohamed; Sim, Stella; Lim, Alan; Hiem, Biow; Chuen, Lieu Chia; Ang, Jesline; Lim, Ek Chow; Klein, Dana; Amit, Eran; Volkovitch, Roie; Tien, David; Choi, DongSub

    2015-03-01

    In advanced semiconductor industries, the overlay error budget is getting tighter due to shrinkage in technology. To fulfill the tighter overlay requirements, gaining every nanometer of improved overlay is very important in order to accelerate yield in high-volume manufacturing (HVM) fabs. To meet the stringent overlay requirements and to overcome other unforeseen situations, it is becoming critical to eliminate the smallest imperfections in the metrology targets used for overlay metrology. For standard cases, the overlay metrology recipe is selected based on total measurement uncertainty (TMU). However, under certain circumstances, inaccuracy due to target imperfections can become the dominant contributor to the metrology uncertainty and cannot be detected and quantified by the standard TMU. For optical-based overlay (OBO) metrology targets, mark asymmetry is a common issue which can cause measurement inaccuracy, and it is not captured by standard TMU. In this paper, a new calibration method, Archer Self-Calibration (ASC), has been established successfully in HVM fabs to improve overlay accuracy on image-based overlay (IBO) metrology targets. Additionally, a new color selection methodology has been developed for the overlay metrology recipe as part of this calibration method. In this study, Qmerit-calibrated data has been used for run-to-run control loop at multiple devices. This study shows that color filter can be chosen more precisely with the help of Qmerit data. Overlay stability improved by 10~20% with best color selection, without causing any negative impact to the products. Residual error, as well as overlay mean plus 3-sigma, showed an improvement of up to 20% when Qmerit-calibrated data was used. A 30% improvement was seen in certain electrical data associated with tested process layers.

  17. Logical Networks: Towards Foundations for Programmable Overlay Networks and Overlay Computing Systems

    OpenAIRE

    Liquori, Luigi; Cosnard, Michel

    2007-01-01

    International audience; We propose and discuss foundations for programmable overlay networks and overlay computing systems. Such overlays are built over a large number of distributed computational individuals, virtually organized in colonies, and ruled by a leader (broker) who is elected or imposed by system administrators. Every individual asks the broker to log in the colony by declaring the resources that can be offered (with variable guarantees). Once logged in, an individual can ask the ...

  18. Polishing Your Transparencies: Mounting, Masking, Overlays.

    Science.gov (United States)

    Jobe, Holly; Cannon, Glenn

    This brief guide discusses the mounting of overhead transparencies on frames, the types of mounts, the proper masking for presentation, and the use of overlays. Numerous line drawings provide the reader with a helpful visual reference. (RAO)

  19. Diffraction based overlay and image based overlay on production flow for advanced technology node

    Science.gov (United States)

    Blancquaert, Yoann; Dezauzier, Christophe

    2013-04-01

    One of the main challenges for lithography step is the overlay control. For the advanced technology node like 28nm and 14nm, the overlay budget becomes very tight. Two overlay techniques compete in our advanced semiconductor manufacturing: the Diffraction based Overlay (DBO) with the YieldStar S200 (ASML) and the Image Based Overlay (IBO) with ARCHER (KLA). In this paper we will compare these two methods through 3 critical production layers: Poly Gate, Contact and first metal layer. We will show the overlay results of the 2 techniques, explore the accuracy and compare the total measurement uncertainty (TMU) for the standard overlay targets of both techniques. We will see also the response and impact for the Image Based Overlay and Diffraction Based Overlay techniques through a process change like an additional Hardmask TEOS layer on the front-end stack. The importance of the target design is approached; we will propose more adapted design for image based targets. Finally we will present embedded targets in the 14 FDSOI with first results.

  20. 3D Finite Element Analysis of HMA Overlay Mix Design to Control Reflective Cracking

    CERN Document Server

    Ghauch, Ziad G

    2011-01-01

    One of the most common rehabilitation techniques of deteriorated pavements is the placement of an HMA overlay on top of the existing Asphalt Concrete (AC) or Portland Cement Concrete (PCC) pavement. However, shortly after pavement resurfacing, HMA overlays exhibit a cracking pattern similar to that of the underlying pavement. This phenomenon is known as reflective cracking. This study examines the effectiveness of several HMA overlay mix design strategies for the purpose of controlling the development of reflective cracking. A parametric study was conducted using a 3D Finite Element (FE) model of a rigid pavement section including a Linear Viscoelastic (LVE) model for Hot Mix Asphalt (HMA) materials and non-uniform tire-pavement contact stresses. Results obtained show that for the intermediate and surface courses, using a Dense Graded (DG) or Polymer Modified (PM) asphalt mixture instead of a Standard Binder (SB) mixture results in reduced tensile stresses at the bottom of the HMA overlay but higher levels of...

  1. Overlay degradation induced by film stress

    Science.gov (United States)

    Huang, Chi-hao; Liu, Yu-Lin; Luo, Shing-Ann; Yang, Mars; Yang, Elvis; Hung, Yung-Tai; Luoh, Tuung; Yang, T. H.; Chen, K. C.

    2017-03-01

    The semiconductor industry has continually sought the approaches to produce memory devices with increased memory cells per memory die. One way to meet the increasing storage capacity demand and reduce bit cost of NAND flash memories is 3D stacked flash cell array. In constructing 3D NAND flash memories, increasing the number of stacked layers to build more memory cell number per unit area necessitates many high-aspect-ratio etching processes accordingly the incorporation of thick and unique etching hard-mask scheme has been indispensable. However, the ever increasingly thick requirement on etching hard-mask has made the hard-mask film stress control extremely important for maintaining good process qualities. The residual film stress alters the wafer shape consequently several process impacts have been readily observed across wafer, such as wafer chucking error on scanner, film peeling, materials coating and baking defects, critical dimension (CD) non-uniformity and overlay degradation. This work investigates the overlay and residual order performance indicator (ROPI) degradation coupling with increasingly thick advanced patterning film (APF) etching hard-mask. Various APF films deposited by plasma enhanced chemical vapor deposition (PECVD) method under different deposition temperatures, chemicals combinations, radio frequency powers and chamber pressures were carried out. And -342MPa to +80MPa film stress with different film thicknesses were generated for the overlay performance study. The results revealed the overlay degradation doesn't directly correlate with convex or concave wafer shapes but the magnitude of residual APF film stress, while increasing the APF thickness will worsen the overlay performance and ROPI strongly. High-stress APF film was also observed to enhance the scanner chucking difference and lead to more serious wafer to wafer overlay variation. To reduce the overlay degradation from ever increasingly thick APF etching hard-mask, optimizing the

  2. A moving overlay shrinks the attentional blink.

    Science.gov (United States)

    Chua, Fook K

    2015-01-01

    This report describes a study examining the effects of overlaying a veil of spots on the letters in a central rapid serial visual presentation stream. Observers identified two target letters (T1 and T2, respectively) embedded in a stream of distractor letters printed in a different color. In Experiment 1, the attentional blink (AB) diminished when a different overlay veiled each letter, such that the spots appeared to move as the letters changed. Experiment 2 concerned whether the performance enhancement occurred because the overlay hampered processing of the lag 1 distractor, thus weakening the distractor's interference with T1. Experiment 3 focused on how changing the overlay at or around T1 affected the AB. The attention disengagement hypothesis was proposed to explain the common theme in the results-that performance was only enhanced when different overlays were applied to the T1 and lag 1 frames. The claim is that the AB reflects a failure of prompt attentional disengagement from T1, which, in turn, delays reengagement when T2 appears shortly thereafter. When T1's disappearance is accompanied by an overlay change, the perceptual system gets an additional cue signaling that the visual scene has changed, thereby inducing attentional disengagement. Apart from facilitating prompt reengagement at the next target, earlier disengagement also improves target recovery by excluding features of the trailing item, likely to be a distractor, from working memory.

  3. Structural integrity analyses for preemptive weld overlay on the dissimilar metal weld of a pressurizer nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chin-Cheng, E-mail: cchuang@iner.gov.tw [Institute of Nuclear Energy Research, Taiwan (China); Liu, Ru-Feng [Institute of Nuclear Energy Research, Taiwan (China)

    2012-02-15

    This paper presents structural integrity analyses for preemptive weld overlay on the dissimilar metal weld (DMW) of a pressurizer nozzle in a pressurized water reactor (PWR). Based on MRP-169 and ASME Code Case N-504-2, weld overlay sizing calculation, residual stress improvement, shrinkage evaluation, fatigue crack growth and fatigue usage analysis are performed. The weld overlay procedure has to be confirmed to improve the residual stresses around the inside surface of DMW. The residual compressive stress distribution is thus addressed to be resistant to subsequent primary water stress corrosion cracking (PWSCC) initiation and further crack growth. To ensure the structural integrity of the original attached piping system, the measured displacement is transformed to temperature gradient to simulate the shrinkage after overlay and is used to determine the post weld distortion and stress situation. Further, the conservative postulated surface cracks are assumed in the DMW for fatigue crack growth analysis with system design cycles. The stress limits and cumulative fatigue usages of the pressurizer nozzle with overlay are also evaluated to meet ASME Code, Section III. Based on the present results, the structural integrity of the pressurizer nozzle with preemptive weld overlay is shown.

  4. Correlation-aware multimedia content distribution in overlay networks

    Science.gov (United States)

    Zhu, Ying; Li, Baochun

    2006-01-01

    We address the question: What is the best way to construct a mesh overlay topology for multimedia content distribution, such that the highest streaming rate can be achieved? We model overlay capacity correlations as linear capacity constraints (LCC) and propose a distributed algorithm that constructs an overlay mesh which incorporates heuristically inferred linear capacity constraints. Our simulations results confirm the accuracy of representing overlays using our LCC model and show the LCC-overlay achieving substantial improvement in achievable flow rate.

  5. Diffusion Barriers to Increase the Oxidative Life of Overlay Coatings

    Science.gov (United States)

    Nesbitt, James A.; Lei, Jih-Fen

    1999-01-01

    Currently, most blades and vanes in the hottest section of aero gas turbine engines require some type of coating for oxidation protection. Newly developed single crystal superalloys have the mechanical potential to operate at increasingly higher component temperatures. However, at these elevated temperatures, coating/substrate interdiffusion can shorten the protective life of the coating. Diffusion barriers between overlay coatings and substrates are being examined to extend the protective life of the coating. A previously- developed finite-difference diffusion model has been modified to predict the oxidative life enhancement due to use of a diffusion barrier. The original diffusion model, designated COSIM, simulates Al diffusion in the coating to the growing oxide scale as well as Al diffusion into the substrate. The COSIM model incorporates an oxide growth and spalling model to provide the rate of Al consumption during cyclic oxidation. Coating failure is predicted when the Al concentration at the coating surface drops to a defined critical level. The modified COSIM model predicts the oxidative life of an overlay coating when a diffusion barrier is present eliminating diffusion of Al from the coating into the substrate. Both the original and the modified diffusion models have been used to predict the effectiveness of a diffusion barrier in extending the protective life of a NiCrAl overlay coating undergoing cyclic oxidation at 1100 C.

  6. Enhacement of intrafield overlay using a design based metrology system

    Science.gov (United States)

    Jo, Gyoyeon; Ji, Sunkeun; Kim, Shinyoung; Kang, Hyunwoo; Park, Minwoo; Kim, Sangwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Maruyama, Kotaro; Park, Byungjun

    2016-03-01

    As the scales of the semiconductor devices continue to shrink, accurate measurement and control of the overlay have been emphasized for securing more overlay margin. Conventional overlay analysis methods are based on the optical measurement of the overlay mark. However, the overlay data obtained from these optical methods cannot represent the exact misregistration between two layers at the circuit level. The overlay mismatch may arise from the size or pitch difference between the overlay mark and the real pattern. Pattern distortion, caused by CMP or etching, could be a source of the overlay mismatch as well. Another issue is the overlay variation in the real circuit pattern which varies depending on its location. The optical overlay measurement methods, such as IBO and DBO that use overlay mark on the scribeline, are not capable of defining the exact overlay values of the real circuit. Therefore, the overlay values of the real circuit need to be extracted to integrate the semiconductor device properly. The circuit level overlay measurement using CDSEM is time-consuming in extracting enough data to indicate overall trend of the chip. However DBM tool is able to derive sufficient data to display overlay tendency of the real circuit region with high repeatability. An E-beam based DBM(Design Based Metrology) tool can be an alternative overlay measurement method. In this paper, we are going to certify that the overlay values extracted from optical measurement cannot represent the circuit level overlay values. We will also demonstrate the possibility to correct misregistration between two layers using the overlay data obtained from the DBM system.

  7. Reducibility, heats of re-oxidation, and structure of vanadia supported on TiO{sub 2} and TiO{sub 2}-Al{sub 2}O{sub 3} supports used as vanadium traps in FCC

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Silvia [CIEP/Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava 6, Zona Universitaria, CP 78210 San Luis Potosi, SLP Mexico (Mexico); Morales, Rosario [CIEP/Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava 6, Zona Universitaria, CP 78210 San Luis Potosi, SLP Mexico (Mexico); Cardenas-Galindo, Maria Guadalupe [CIEP/Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava 6, Zona Universitaria, CP 78210 San Luis Potosi, SLP Mexico (Mexico); Rodriguez, A. Gabriel [Instituto de Investigaciones en Comunicaciones y Opticas, Universidad Autonoma de San Luis Potosi, Av. Karakorum 1470, CP 78216 San Luis Potosi, SLP Mexico (Mexico); Pedraza, Francisco [Instituto Mexicano del Petroleo, Eje Centrale Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, Delg. Gustavo I. Madero, Mexico DF 07730 (Mexico); Handy, Brent E. [CIEP/Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava 6, Zona Universitaria, CP 78210 San Luis Potosi, SLP Mexico (Mexico)]. E-mail: handy@uaslp.mx

    2005-08-15

    V/TiO{sub 2} and V/TiO{sub 2}-Al{sub 2}O{sub 3} (1:1 w/w basis) supports were characterized by TPR, Raman spectroscopy, and heats of re-oxidation of samples pre-reduced in CO at 770 K with a heat-flow calorimeter. Supports were pure anatase or rutile dispersed with hydrated aluminas (boehmite, gibbsite, bayerite) subsequently calcined at 870 K. Raman spectroscopy of fully oxidized, air-exposed samples show the presence of polymeric polyvanadate species, but not of isolated monomeric species. Sample loadings were 4 wt.% and show different reduction and structural features. During TPR, vanadia reduced to V(III) and V(IV) in V/rutile and V/anatase, respectively, and multiple reduction peaks were observed due to crystalline V{sub 2}O{sub 5} and amorphous vanadia. In V/TiO{sub 2}-Al{sub 2}O{sub 3} samples, vanadium coverages were 6-8 {mu}mol V m{sup -2} yielding well-dispersed, amorphous vanadia. Trends observed during TPR were: addition of bayerite phase to anatase or rutile increases H{sub 2} consumption by 100%, implying formation of V(III) and V(II), respectively. However, with addition of boehmite or gibbsite to either titania phase, vanadia reduces only to V(IV). Oxygen doses at 473 K of pre-reduced samples titrated about one-third of total vanadia content. Re-oxidation heat values range from 400 to 500 kJ mol{sup -1} O{sub 2} and represent oxygen-vanadium ion bond strengths within the dispersed vanadia. The heat values are higher than expected for re-oxidation of a bulk phase, and are indicative of the degree of stabilization provided by the support.

  8. Robotic weld overlay coatings for erosion control

    Science.gov (United States)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  9. Duplex 2209 Weld Overlay by ESSC Process

    Directory of Open Access Journals (Sweden)

    Er. Manoj Kumar

    2017-03-01

    Full Text Available In the modern world of industrialization the wear is eating metal assets worth millions of dollars per year. The wear is in the form of corrosion, erosion, abrasion etc. which occur in the process industries like oil & gas, refineries, cement plants, steel plants, shipping and offshore working structures. The equipments like pressure vessels, heat exchangers, hydro processing reactors which very often work at elevated temperatures face corrosion in the internal diameter. Duplex 2209 weld overlay on ferrous material is developed for high corrosion resistance properties and having high productivity by Electroslag strip cladding process due to its less dilution ~10% as compared to SMAW , GTAW or FCAW process. Because of Low Dilution ~10% undiluted chemistry can be achieved with single layer as compared to other weld overlay processes. The facility was developed inhouse to carry out weld overlay by ESSC and Testing

  10. Patent Overlay Mapping: Visualizing Technological Distance

    CERN Document Server

    Kay, Luciano; Youtie, Jan; Porter, Alan L; Rafols, Ismael

    2012-01-01

    The purpose of this paper is to present a new global patent map that represents all technological categories, and a method to locate patent data of individual organizations and technological fields on the global map. This second patent overlay map technique is shown to be of potential interest to support competitive intelligence and policy decision-making. The global patent map is based on similarities in citing-to-cited relationships between categories of the International Patent Classification (IPC) of European Patent Office (EPO) patents from 2000 to 2006. This patent dataset, extracted from PatStat database, represents more than 760,000 patent records in more than 400 IPC categories. To illustrate the kind of analytical support offered by this approach, the paper shows the overlay of nanotechnology-related patenting activities of two companies and two different nanotechnology subfields on to the global patent map. The exercise shows the potential of patent overlay maps to visualize technological areas and...

  11. Exploring overlay journals: the RIOJA project

    CERN Document Server

    CERN. Geneva

    2007-01-01

    Researchers in cosmology and astrophysics depend on the arXiv repository for the registration and dissemination of their work, as well as for current awareness, yet they continue to submit papers to journals for review. Could rapid quality certification be overlaid directly onto the arXiv repository? This presentation introduces the RIOJA (Repository Interface to Overlaid Journal Archives) project, on which a group of cosmology researchers from the UK is working with UCL Library Services and Cornell University. The project is creating a tool to support the overlay of journals onto repositories, and will demonstrate a cosmology journal overlaid on top of arXiv. RIOJA will also work with the cosmology community to explore the social and economic aspects of journal overlay in this discipline: what other value, besides the quality stamp, does journal publication typically add? What are the costs of the ideal overlay journal for this community, and how could those costs be recovered? Would researchers real...

  12. KML Super Overlay to WMS Translator

    Science.gov (United States)

    Plesea, Lucian

    2007-01-01

    This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

  13. Hybrid overlay metrology for high order correction by using CDSEM

    Science.gov (United States)

    Leray, Philippe; Halder, Sandip; Lorusso, Gian; Baudemprez, Bart; Inoue, Osamu; Okagawa, Yutaka

    2016-03-01

    Overlay control has become one of the most critical issues for semiconductor manufacturing. Advanced lithographic scanners use high-order corrections or correction per exposure to reduce the residual overlay. It is not enough in traditional feedback of overlay measurement by using ADI wafer because overlay error depends on other process (etching process and film stress, etc.). It needs high accuracy overlay measurement by using AEI wafer. WIS (Wafer Induced Shift) is the main issue for optical overlay, IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). We design dedicated SEM overlay targets for dual damascene process of N10 by i-ArF multi-patterning. The pattern is same as device-pattern locally. Optical overlay tools select segmented pattern to reduce the WIS. However segmentation has limit, especially the via-pattern, for keeping the sensitivity and accuracy. We evaluate difference between the viapattern and relaxed pitch gratings which are similar to optical overlay target at AEI. CDSEM can estimate asymmetry property of target from image of pattern edge. CDSEM can estimate asymmetry property of target from image of pattern edge. We will compare full map of SEM overlay to full map of optical overlay for high order correction ( correctables and residual fingerprints).

  14. Use of Hydrogen Chemisorption and Ethylene Hydrogenation as Predictors for Aqueous Phase Reforming of Lactose over Ni@Pt and Co@Pt Bimetallic Overlayer Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Qinghua; Skoglund, Michael D.; Zhang, Chen; Morris, Allen R.; Holles, Joseph H.

    2016-10-20

    Overlayer Pt on Ni (Ni@Pt) or Co (Co@Pt) were synthesized and tested for H2 generation from APR of lactose. H2 chemisorption descriptor showed that Ni@Pt and Co@Pt overlayer catalysts had reduced H2 adsorption strength compared to a Pt only catalyst, which agree with computational predictions. The overlayer catalysts also demonstrated lower activity for ethylene hydrogenation than the Pt only catalyst, which likely resulted from decreased H2 binding strength decreasing the surface coverage of H2. XAS results showed that overlayer catalysts exhibited higher white line intensity than the Pt catalyst, which indicates a negative d-band shift for the Pt overlayer, further providing evidence for overlayer formation. Lactose APR studies showed that lactose can be used as feedstock to produce H2 and CO under desirable reaction conditions. The Pt active sites of Ni@Pt and Co@Pt overlayer catalysts showed significantly enhanced H2 production selectivity and activity when compared with that of a Pt only catalyst. The single deposition overlayer with the largest d-band shift showed the highest H2 activity. The results suggest that overlayer formation using directed deposition technique could modify the behavior of the surface metal and ultimately modify the APR activity.

  15. Study on cracking of welding overlay based on the theory of diffusion-induced stress

    Institute of Scientific and Technical Information of China (English)

    Xiliang ZHANG; Changyu ZHOU

    2011-01-01

    Hydrogen diffusion in the wall of hydrogenation reactor for three situations,i.e. operating,normal shutdown and abnormal shutdown,was numerically simulated based on the finite element program-ABAQUS. The formula of diffusion-induced stress was deduced for model of the thin walled cylinder. Distribution of diffusion-induced stress in the wall of hydrogenation reactor was studied. The results showed that the maximum stress was at the fusion surface between welding overlay and base metal,and which would increase with cooling rate. The crack will initiate and propagate from fusion surface to welding overlay when the diffusion-induced stress is higher than yield stress,but it will not propagate to the base metal. Diffusion-induced stress is one of the important factors for crack initiation and propagation of welding overlay of hydrogenation reactor.

  16. Laser-induced desorption of overlayer films off a heated metal substrate

    Science.gov (United States)

    Gu, Xiang; Urbassek, Herbert M.

    2007-02-01

    The temperature-induced desorption of adsorbed overlayer films with thicknesses between 4 and 200 ML off a suddenly heated metal substrate is studied using molecular-dynamics simulation. We observe that the rapid heating vaporizes the surface-near part of the overlayer film. The initial heating-induced thermoelastic pressure and the vapor pressure in the vapor film drive the remaining film as a large relatively cold cluster away from the surface. In our simulations, the material present in the developing vapor film amounts to roughly 2 ML and is quite independent of the overlayer film thickness. For cluster thicknesses beyond 40 ML, the desorption time increases only little with film thickness, while the resulting cluster velocity decreases only slightly.

  17. Colors, colored overlays, and reading skills

    Directory of Open Access Journals (Sweden)

    Arcangelo eUccula

    2014-07-01

    Full Text Available In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e. who experience eyestrain and/or visual distortions – e.g. color, shape or movement illusions – while reading. This condition would interest the 12-14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature.

  18. Physical expander in Virtual Tree Overlay

    CERN Document Server

    Izumi, Taisuke; Valero, Mathieu

    2011-01-01

    In this paper, we propose a new construction of constantdegree expanders motivated by their application in P2P overlay networks and in particular in the design of robust trees overlay. Our key result can be stated as follows. Consider a complete binary tree T and construct a random pairing {\\Pi} between leaf nodes and internal nodes. We prove that the graph G\\Pi obtained from T by contracting all pairs (leaf-internal nodes) achieves a constant node expansion with high probability. The use of our result in improving the robustness of tree overlays is straightforward. That is, if each physical node participating to the overlay manages a random pair that couples one virtual internal node and one virtual leaf node then the physical-node layer exhibits a constant expansion with high probability. We encompass the difficulty of obtaining this random tree virtualization by proposing a local, selforganizing and churn resilient uniformly-random pairing algorithm with O(log2 n) running time. Our algorithm has the merit ...

  19. Low temperature influence in the predicted of pavement overlay

    OpenAIRE

    Minhoto, Manuel; Pais, Jorge; Pereira, Paulo; Picado-Santos, Luís

    2003-01-01

    This paper describes a study of the influence of temperature variation in the pavement overlay life, using finite-element methodology that considers the most predominant type of overlay distress observed in the field: the reflective cracking. The temperature variation has a significant influence on thermally induced stresses that, in turn, affects the overlay predictive service life. This paper presents a three-dimensional (3D) finite element analysis used to predict the pavement overlay life...

  20. An Overlay Architecture for Throughput Optimal Multipath Routing

    Science.gov (United States)

    2017-01-14

    1 An Overlay Architecture for Throughput Optimal Multipath Routing Nathaniel M. Jones, Georgios S. Paschos, Brooke Shrader, and Eytan Modiano...decisions. In this work, we study an overlay architecture for dynamic routing such that only a subset of devices (overlay nodes) need to make dynamic routing...a legacy network. Network overlays are frequently used to deploy new communication architectures in legacy networks [13]. To accomplish this, messages

  1. Large dynamic range Atomic Force Microscope for overlay improvements

    NARCIS (Netherlands)

    Kuiper, S.; Fritz, E.C.; Crowcombe, W.E.; Liebig, T.; Kramer, G.F.I.; Witvoet, G.; Duivenvoorde, T.; Overtoom, A.J.; Rijnbeek, R.A.; Zwet, E.J. van; Dijsseldonk, A. van; Boef, A. den; Beems, M.; Levasier, L.

    2016-01-01

    Nowadays most overlay metrology tools assess the overlay performance based on marker features which are deposited next to the functional device features within each layer of the semiconductor device. However, correct overlay of the relatively coarse marker features does not directly guarantee correc

  2. Network-aware SuperPeers-Peers Geometric Overlay Network

    NARCIS (Netherlands)

    Lua, E.K.; Zhou, X.

    2007-01-01

    Peer-to-Peer (P2P) overlay networks can be utilized to deploy massive Internet overlay services such as multicast, content distribution, file sharing, etc. efficiently without any underlying network support. The crucial step to meet this objective is to design network-aware overlay network

  3. Network-aware SuperPeers-Peers Geometric Overlay Network

    NARCIS (Netherlands)

    Lua, E.K.; Zhou, X.

    2007-01-01

    Peer-to-Peer (P2P) overlay networks can be utilized to deploy massive Internet overlay services such as multicast, content distribution, file sharing, etc. efficiently without any underlying network support. The crucial step to meet this objective is to design network-aware overlay network topologie

  4. Network-aware SuperPeers-Peers Geometric Overlay Network

    NARCIS (Netherlands)

    Lua, E.K.; Zhou, X.

    2007-01-01

    Peer-to-Peer (P2P) overlay networks can be utilized to deploy massive Internet overlay services such as multicast, content distribution, file sharing, etc. efficiently without any underlying network support. The crucial step to meet this objective is to design network-aware overlay network topologie

  5. Influence of curing time, overlay material and thickness on three light-curing composites used for luting indirect composite restorations.

    Science.gov (United States)

    D'Arcangelo, Camillo; De Angelis, Francesco; Vadini, Mirco; Carluccio, Fabio; Vitalone, Laura Merla; D'Amario, Maurizio

    2012-08-01

    To assess the microhardness of three resin composites employed in the adhesive luting of indirect composite restorations and examine the influence of the overlay material and thickness as well as the curing time on polymerization rate. Three commercially available resin composites were selected: Enamel Plus HRI (Micerium) (ENA), Saremco ELS (Saremco Dental) (SAR), Esthet-X HD (Dentsply/DeTrey) (EST-X). Post-polymerized cylinders of 6 different thicknesses were produced and used as overlays: 2 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, and 6 mm. Two-mm-thick disks were produced and employed as underlays. A standardized amount of composite paste was placed between the underlay and the overlay surfaces which were maintained at a fixed distance of 0.5 mm. Light curing of the luting composite layer was performed through the overlays for 40, 80, or 120 s. For each specimen, the composite to be cured, the cured overlay, and the underlay were made out of the same batch of resin composite. All specimens were assigned to three experimental groups on the basis of the resin composite used, and to subgroups on the basis of the overlay thickness and the curing time, resulting in 54 experimental subgroups (n = 5). Forty-five additional specimens, 15 for each material under investigation, were produced and subjected to 40, 80, or 120 s of light curing using a microscope glass as an overlay; they were assigned to 9 control subgroups (n = 5). Three Vicker's hardness (VH) indentations were performed on each specimen. Means and standard deviations were calculated. Data were statistically analyzed using 3-way ANOVA. Within the same material, VH values lower than 55% of control were not considered acceptable. The used material, the overlay thickness, and the curing time significantly influenced VH values. In the ENA group, acceptable hardness values were achieved with 3.5-mm or thinner overlays after 120 or 80 s curing time (VH 41.75 and 39.32, respectively), and with 2-mm overlays after 40 s (VH 54

  6. Overlay welding for corrugating roll

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of chemical compositions and microstructures on wearability properties of overlaid corrugating roll were studied, and the factors governing the hardness and the wearability of overlaid layer were explored.The results show that the hardness and wearability of the overlaid layer significantly rise with the increase of the mass fraction of various types of eutectic, but the crack-resistance falls. The chief factor governing the hardness of overlaid layer is the matrix microstructure, especially the amount of austenite; and the second is the amount of carbide. The principal factor governing the wearability of overlaid layer is the amount of special carbide, particularly the amount of eutectic; and the second is the hardness of overlaid layer. Meanwhile, high alloying electrodes may cause the gear-surface hardness of corrugating roll to be higher than 63HRc, and may enhance the wearability of the gear-surface of corrugating roll by a factor of 5.63 and 9.08.

  7. Analysis of overlay weld effect on preventing PWSCC in dissimilar metal weld

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Gun; Oh, Chang Kyun; Jin, Tae Eun [Korea Power Engineering Co., Inc., Yongin (Korea, Republic of); Kim, Yong Tae [Korea Plant Service and Engineering Co., Ltd., Seongnam (Korea, Republic of); Yoo, Sung Soo [Korea Hydro and Nuclear Power Co., Ltd., Seoul (Korea, Republic of)

    2009-07-01

    PWSCC(Primary Stress Corrosion Cracking) in Alloy 82/182 butt welds is the problem affecting safety and integrity of nuclear power plant. PWSCC can be occurred in high magnitude of tensile residual stress, such as Alloy 82/182 dissimilar metal welds in Pressurizer(PZR) nozzles. There have been related incidents recently at the dissimilar metal welds in overseas nuclear power plants. Overlay weld is the one of the effective methods to decrease tensile residual stress of inside surface, which will result in preventing PWSCC. In this paper, overlay weld conditions on the purpose of preventing PWSCC was explained and the benefit of the overlay weld was confirmed performing finite element analysis.

  8. Analysis of Overlay Weld Effect on Preventing PWSCC in Dissimilar Metal Weld

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Gun; Oh, Chang Kyun; Park, Heung Bae; Jin, Tae Eun [Korea Power Engineering Company, Daejeon (Korea, Republic of)

    2010-01-15

    PWSCC(Primary Stress Corrosion Cracking) in Alloy 82/182 butt welds is the problem affecting safety and integrity of nuclear power plant. PWSCC can be occurred in the area that is at high magnitude of tensile residual stress, such as Alloy 82/182 dissimilar metal welds in PZR(pressurizer) nozzles. There have been a number of incidents recently at the dissimilar metal welds in overseas nuclear power plants. Overlay weld is the one of the effective methods to decrease tensile residual stress of inside surface, which will result in preventing PWSCC. In this paper, overlay weld conditions on the purpose of preventing PWSCC was explained and the benefit of the overlay weld was confirmed performing finite element analysis.

  9. Maxillary and mandibular overlay removable partial dentures for the restoration of worn teeth.

    Science.gov (United States)

    Ganddini, Mario R; Al-Mardini, Majd; Graser, Gerald N; Almog, Dov

    2004-03-01

    This clinical report describes the fabrication of maxillary and mandibular cast overlay removable partial dentures for the restoration of severely worn teeth with accompanying loss of vertical dimension of occlusion. The frameworks supported porcelain veneers for esthetics and metal occlusal surfaces for strength and durability.

  10. Using overlays to improve network security

    Science.gov (United States)

    Keromytis, Angelos D.; Misra, Vishal; Rubenstein, Daniel

    2002-07-01

    As we increase our dependency upon networked communication, the incentive to compromise and degrade network performance increases for those who wish to disrupt the flow of information. Attacks that lead to such compromise and degradation can come in a variety of forms, including distributed denial of service (DDoS) attacks, cutting wires, jamming transmissions, and monitoring/eavesdropping. Users can protect themselves from monitoring by applying cryptographic techniques, and the recent work has explored developing networks that react to DDoS attacks by locating the source(s) of the attack. However, there has been little work that addresses preventing the other kinds of attacks as opposed to reacting to them. Here, we discuss how network overlays can be used to complicate the job of an attacker that wishes to prevent communication. To amplify our point, we focus briefly on a study of preventing DDoS attacks by using overlays.

  11. ATLAS Pile-up and Overlay Simulation

    CERN Document Server

    Novak, Tadej; The ATLAS collaboration

    2017-01-01

    The high luminosity of the LHC results in a significant background to interesting physics events known as pile-up. ATLAS uses several methods for simulating the effects of pile-up. The mostly used method is a direct simulation of background events where multiple simulated background events are combined for each physics event. For some physics processes, a more accurate simulation can be achieved by overlaying real proton-proton collisions on a simulated hard-scatter process. Overlay is also being investigated for a premixed pile-up background to reduce CPU usage and I/O stress during the simulation. Embedding replaces the muons found in Z→mumu decays in data with simulated taus at the same 4-momenta, thus preserving the underlying event and pileup from the original data event. This talk compares the pile-up simulation methods used at the ATLAS experiment pointing their benefits and drawbacks.

  12. Süperpozisyon apareyleri (*) (Overlay Dentures)

    OpenAIRE

    Muğan, Nuri; Cansevergil, Esengün

    2013-01-01

    SUMMARYRemovable partial or complete prothèses which are used to alleviate maxillary constriction and discrepancies in vertical -dimension are called « overlay dentures». The patients maxillary teeth or ridge is overiayed by acriylic and the artificial teeth are positioned in accordance with the mandibular teeth to establish a better occlusion as well as to improve the estetios of the individual. The improved anterior tooth relationships also provide the anatomic basis for the correct produc...

  13. Overlay Spectrum Sharing using Improper Gaussian Signaling

    KAUST Repository

    Amin, Osama

    2016-11-30

    Improper Gaussian signaling (IGS) scheme has been recently shown to provide performance improvements in interference limited networks as opposed to the conventional proper Gaussian signaling (PGS) scheme. In this paper, we implement the IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to match the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio to maximize the secondary link achievable rate while satisfying the primary network quality of service requirements. In particular, we consider full and partial channel knowledge scenarios and derive the feasibility conditions of operating the overlay cognitive radio systems. Moreover, we derive the superiority conditions of the IGS schemes over the PGS schemes supported with closed form expressions for the corresponding power distribution and the circularity coefficient and parameters. Simulation results are provided to support our theoretical derivations.

  14. Achieving optimum diffraction based overlay performance

    Science.gov (United States)

    Leray, Philippe; Laidler, David; Cheng, Shaunee; Coogans, Martyn; Fuchs, Andreas; Ponomarenko, Mariya; van der Schaar, Maurits; Vanoppen, Peter

    2010-03-01

    Diffraction Based Overlay (DBO) metrology has been shown to have significantly reduced Total Measurement Uncertainty (TMU) compared to Image Based Overlay (IBO), primarily due to having no measurable Tool Induced Shift (TIS). However, the advantages of having no measurable TIS can be outweighed by increased susceptibility to WIS (Wafer Induced Shift) caused by target damage, process non-uniformities and variations. The path to optimum DBO performance lies in having well characterized metrology targets, which are insensitive to process non-uniformities and variations, in combination with optimized recipes which take advantage of advanced DBO designs. In this work we examine the impact of different degrees of process non-uniformity and target damage on DBO measurement gratings and study their impact on overlay measurement accuracy and precision. Multiple wavelength and dual polarization scatterometry are used to characterize the DBO design performance over the range of process variation. In conclusion, we describe the robustness of DBO metrology to target damage and show how to exploit the measurement capability of a multiple wavelength, dual polarization scatterometry tool to ensure the required measurement accuracy for current and future technology nodes.

  15. Facilitating Service Discovery with Semantic Overlay

    Institute of Scientific and Technical Information of China (English)

    Hai Jin; Hao Wu; Xiao-Min Ning

    2006-01-01

    Service Oriented Architecture (SOA) and Peer-to-Peer (P2P) computing share many common characteristics.It is believed that the combination of the two emerging techniques is a very promising method in promoting the web services (WS). Because the service discovery plays a key role in the integration, here a P2P-based framework to manage the knowledge of service and locating services is proposed. In this paper, the details of the principle, constructing and maintaining of service semantic overlay architecture have been described, and the way how the semantic overlay facilitates discovery of service resources is illustrated. To enable the semantic web service superiority, Service Ontology, which is considered as the service semantic model, is employed to depict service. The service discovery includes two phases: searching on the service semantic overlay; and local discovery in peer's service repository. Various solutions have been proposed to realize those two phases.Furthermore, tests are carried out to evaluate service discovery on the architecture.

  16. High-throughput electrical characterization for robust overlay lithography control

    Science.gov (United States)

    Devender, Devender; Shen, Xumin; Duggan, Mark; Singh, Sunil; Rullan, Jonathan; Choo, Jae; Mehta, Sohan; Tang, Teck Jung; Reidy, Sean; Holt, Jonathan; Kim, Hyung Woo; Fox, Robert; Sohn, D. K.

    2017-03-01

    Realizing sensitive, high throughput and robust overlay measurement is a challenge in current 14nm and advanced upcoming nodes with transition to 300mm and upcoming 450mm semiconductor manufacturing, where slight deviation in overlay has significant impact on reliability and yield1). Exponentially increasing number of critical masks in multi-patterning lithoetch, litho-etch (LELE) and subsequent LELELE semiconductor processes require even tighter overlay specification2). Here, we discuss limitations of current image- and diffraction- based overlay measurement techniques to meet these stringent processing requirements due to sensitivity, throughput and low contrast3). We demonstrate a new electrical measurement based technique where resistance is measured for a macro with intentional misalignment between two layers. Overlay is quantified by a parabolic fitting model to resistance where minima and inflection points are extracted to characterize overlay control and process window, respectively. Analyses using transmission electron microscopy show good correlation between actual overlay performance and overlay obtained from fitting. Additionally, excellent correlation of overlay from electrical measurements to existing image- and diffraction- based techniques is found. We also discuss challenges of integrating electrical measurement based approach in semiconductor manufacturing from Back End of Line (BEOL) perspective. Our findings open up a new pathway for accessing simultaneous overlay as well as process window and margins from a robust, high throughput and electrical measurement approach.

  17. New low-viscosity overlay medium for viral plaque assays

    Directory of Open Access Journals (Sweden)

    Garten Wolfgang

    2006-08-01

    Full Text Available Abstract Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3% ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.

  18. SEM based overlay measurement between resist and buried patterns

    Science.gov (United States)

    Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

    2016-03-01

    With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

  19. Assessment of Potential Location of High Arsenic Contamination Using Fuzzy Overlay and Spatial Anisotropy Approach in Iron Mine Surrounding Area

    Directory of Open Access Journals (Sweden)

    Thanes Weerasiri

    2014-01-01

    Full Text Available Fuzzy overlay approach on three raster maps including land slope, soil type, and distance to stream can be used to identify the most potential locations of high arsenic contamination in soils. Verification of high arsenic contamination was made by collection samples and analysis of arsenic content and interpolation surface by spatial anisotropic method. A total of 51 soil samples were collected at the potential contaminated location clarified by fuzzy overlay approach. At each location, soil samples were taken at the depth of 0.00-1.00 m from the surface ground level. Interpolation surface of the analysed arsenic content using spatial anisotropic would verify the potential arsenic contamination location obtained from fuzzy overlay outputs. Both outputs of the spatial surface anisotropic and the fuzzy overlay mapping were significantly spatially conformed. Three contaminated areas with arsenic concentrations of 7.19±2.86, 6.60±3.04, and 4.90±2.67 mg/kg exceeded the arsenic content of 3.9 mg/kg, the maximum concentration level (MCL for agricultural soils as designated by Office of National Environment Board of Thailand. It is concluded that fuzzy overlay mapping could be employed for identification of potential contamination area with the verification by surface anisotropic approach including intensive sampling and analysis of the substances of interest.

  20. Assessment of potential location of high arsenic contamination using fuzzy overlay and spatial anisotropy approach in iron mine surrounding area.

    Science.gov (United States)

    Weerasiri, Thanes; Wirojanagud, Wanpen; Srisatit, Thares

    2014-01-01

    Fuzzy overlay approach on three raster maps including land slope, soil type, and distance to stream can be used to identify the most potential locations of high arsenic contamination in soils. Verification of high arsenic contamination was made by collection samples and analysis of arsenic content and interpolation surface by spatial anisotropic method. A total of 51 soil samples were collected at the potential contaminated location clarified by fuzzy overlay approach. At each location, soil samples were taken at the depth of 0.00-1.00 m from the surface ground level. Interpolation surface of the analysed arsenic content using spatial anisotropic would verify the potential arsenic contamination location obtained from fuzzy overlay outputs. Both outputs of the spatial surface anisotropic and the fuzzy overlay mapping were significantly spatially conformed. Three contaminated areas with arsenic concentrations of 7.19 ± 2.86, 6.60 ± 3.04, and 4.90 ± 2.67 mg/kg exceeded the arsenic content of 3.9 mg/kg, the maximum concentration level (MCL) for agricultural soils as designated by Office of National Environment Board of Thailand. It is concluded that fuzzy overlay mapping could be employed for identification of potential contamination area with the verification by surface anisotropic approach including intensive sampling and analysis of the substances of interest.

  1. Robotic weld overlay coatings for erosion control. Final technical progress report, July 1992--July 1995

    Energy Technology Data Exchange (ETDEWEB)

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1995-10-15

    The erosion behavior of weld overlay coatings has been studied. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400{degrees}C at 90{degrees} and 30{degrees} particle impact angles. The microstructure of each coating was characterized before erosion testing. A relative ranking of the coatings erosion resistance was developed by determining the steady state erosion rates. Ultimet, Inconel-625, and 316L SS coatings showed the best erosion resistance at both impact angles. It was found that weld overlays that exhibit good abrasion resistance did not show good erosion resistance. Erosion tests were also performed for selected wrought materials with chemical composition similar to weld overlays. Eroded surfaces of the wrought and weld alloys were examined by Scanning Electron Microscopy (SEM). Microhardness tests were performed on the eroded samples below the erosion surface to determine size of the plastically deformed region. It was found that one group of coatings experienced significant plastic deformation as a result of erosion while the other did not. It was also established that, in the steady state erosion regime, the size of the plastically deformed region is constant.

  2. Life extension of boilers using weld overlay protection

    Energy Technology Data Exchange (ETDEWEB)

    Lai, G.; Hulsizer, P. [Welding Services Inc., Norcross, GA (United States); Brooks, R. [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

    1998-12-31

    The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

  3. Overlay Technique for Transcatheter Left Atrial Appendage Closure.

    Science.gov (United States)

    Li, Shuang; Zhu, Mengyun; Lu, Yunlan; Tang, Kai; Zhao, Dongdong; Chen, Wei; Xu, Yawei

    2015-08-01

    The Overlay technique is popular in peripheral artery interventions, but not in coronary or cardiac structural procedures. We present an initial experience using three-episode overlays during a transcatheter left atrial appendage closure. The first overlay was applied to facilitate advancement of the delivery sheath into left atrium. The second overlay was used to navigate the advancement of prepped delivery system containing the compressed occluder into its optimal position in the left atrium. The third overlay facilitated the real-time deployment of the closure device. This case report demonstrates the effectiveness of the overlay technique in facilitating each step of the transcatheter left atrial appendage closure. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  4. Topology-aware Overlay Multicast over IP Multicast Networks

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao; SHAO Hua-gang; WANG Wei-nong

    2008-01-01

    Most existing overlay multicast approaches refuse to consider any network layer support no matter whether it is available or not. This design principle greatly increases the complexity of the routing algorithms and makes the overlay topologies incompatible with the underlying network. To address these issues, topology-aware overlay multicast over IP multicast networks (TOMIMN) was proposed as a novel overlay multicast protocol, which exploits the cooperation between end-hosts and IP multicast routers to construct a topology-aware overlay tree. Through a little modification to protocol independent multicast sparse mode (PIM-SM),a multicast router is able to receive registration from nearby group members and redirect passing-by join re-quests to them. Due to the multicast router's support, TOMIMN organizes its group members into an overlay multicast tree efficiently, which matches the physical network topology well.

  5. Layout optimization for multilayer overlay targets

    Science.gov (United States)

    Binns, L. A.; Smith, N. P.; Ausschnitt, C. P.; Morningstar, J.; Muth, W.; Schneider, J.; Yerdon, R.

    2006-03-01

    A novel overlay target developed by IBM and Accent Optical Technologies, Blossom, allows simultaneous overlay measurements of multiple layers (currently, up to 28) with a single target. This is achieved by a rotationally symmetric arrangement of small (4 micron) targets in a 50 micron square area, described more fully in a separate paper. In this paper, we examine the lessons learned in developing and testing the Blossom design. We start by examining proximity effects; the spacing of adjacent targets means that both the precision-like Total Measurement Uncertainty (TMU) and accuracy of a measurement can be affected by proximity of features. We use a mixture of real and modelled data to illustrate this problem, and find that the layout of Blossom reduces the proximity-induced bias. However, we do find that in certain cases proximity effects can increase the TMU of a particular measurement. The solution is to ensure that parts of the target that interact detrimentally are maximally separated. We present a solution to this, viewing the problem as a constrained Travelling Salesman Problem. We have imposed some global constraints, for example printing front-end and back-end layers on separate targets, and consistency with the overlay measurement strategy. Initially, we assume that pairwise measurements are either critical or non-critical, and optimize the layout so that the critical layers are both not placed adjacent to any prior or intermediate-layer features. We then build upon this structure, to consider the effect of low-energy implants (that cannot be seen once processed) and site re-use possibilities. Beyond this, we also investigate the impact of more strategic optimizations, for example, tuning the number of features on each layer. In each case, we present on-product performance data achieved, and modelled data on some additional target variants / extreme cases.

  6. Molecular Dynamics study of Pb overlayer on Cu(100)

    Science.gov (United States)

    Karimi, M.; Tibbits, P.; Ila, D.; Dalins, I.; Vidali, G.

    1991-01-01

    Isothermal-isobaric Molecular Dynamics (MD) simulation of a submonolayer Pb film in c(2x2) ordered structure adsorbed on a Cu(100) substrate showed retention of order to high T. The Embedded Atom Method (EAM) calculated the energy of atoms of overlayer and substrate. The time-averaged squared modulus of the two dimensional structure factor for the Pb overlayer measured the order of the overlayer. The results are for increasing T only, and require verification by simulated cooling.

  7. Overlay performance with advanced ATHENA trademark alignment strategies

    CERN Document Server

    Huijbregtse, Jeroen; Jeunink, Andre; Megens, Henry; Navarro, Ramon; Simons, Geert; Swinnen, Bart; Tolsma, Hoite; Van Bilsen, Frank; Van Haren, Richard

    2003-01-01

    The introduction of the ATHENA**T**M alignment sensor has made advanced applications of the sensor data increasingly important to meet the tightening overlay specifications for future technology nodes. As part of the total overlay budget, the effects of different alignment strategies on overlay performance need to be investigated. Keeping in mind that such strategies are simple and easy to use, two developments are addressed: advanced alignment recipes and advanced mark designs. (Edited abstract) 8 Refs.

  8. Assessment of a Cambridge Structural Database-driven overlay program.

    Science.gov (United States)

    Giangreco, Ilenia; Olsson, Tjelvar S G; Cole, Jason C; Packer, Martin J

    2014-11-24

    We recently published an improved methodology for overlaying multiple flexible ligands and an extensive data set for validating pharmacophore programs. Here, we combine these two developments and present evidence of the effectiveness of the new overlay methodology at predicting correct superimpositions for systems with varying levels of complexity. The overlay program was able to generate correct predictions for 95%, 73%, and 39% of systems classified as easy, moderate, and hard, respectively.

  9. Molecular Dynamics study of Pb overlayer on Cu(100)

    Science.gov (United States)

    Karimi, M.; Tibbits, P.; Ila, D.; Dalins, I.; Vidali, G.

    1991-01-01

    Isothermal-isobaric Molecular Dynamics (MD) simulation of a submonolayer Pb film in c(2x2) ordered structure adsorbed on a Cu(100) substrate showed retention of order to high T. The Embedded Atom Method (EAM) calculated the energy of atoms of overlayer and substrate. The time-averaged squared modulus of the two dimensional structure factor for the Pb overlayer measured the order of the overlayer. The results are for increasing T only, and require verification by simulated cooling.

  10. Capacity of Intelligent Underlay and Overlay Network

    DEFF Research Database (Denmark)

    Ling, Yim; Elling, Jan; Nielsen, Thomas Toftegaard

    1996-01-01

    This paper suggests a method of dimensioning the cell configuration of radio sites in a cellular network using the intelligent overlay and underlay (IOU) technique. The traffic capacity has been analysed by means of a teletraffic model, which is developed based on the classical theory of overflow...... and therefore can be used to dimension the network. The model shows that the increase of capacity for a GSM network with 34 frequencies is about 30%. Further capacity enhancement can be achieved by intelligent frequency planning method which is currently being developed...

  11. The hilum overlay sign in a child

    Directory of Open Access Journals (Sweden)

    M J Van Wyk

    2010-12-01

    Full Text Available A 9-month-old girl presented with a 1-month history of coughing. A chest X-ray (CXR was performed, and the antero-posterior view demonstrated the hilum overlay sign. Furthermore, there was absence of the azygo-oesophageal line and bilateral paraspinal lines. The lateral CXR revealed a posterior mediastinal mass. Subsequently, a computed tomogram of the chest confirmed a posterior mediastinal mass, with calcifications and intraspinal extension consistent with neuroblastoma. Histological analysis confirmed this mass as a neuroblastoma.

  12. Practical Coding Schemes for Cognitive Overlay Radios

    CERN Document Server

    Kurniawan, Ernest; Rini, Stefano

    2012-01-01

    We develop practical coding schemes for the cognitive overlay radios as modeled by the cognitive interference channel, a variation of the classical two user interference channel where one of the transmitters has knowledge of both messages. Inspired by information theoretical results, we develop a coding strategy for each of the three parameter regimes where capacity is known. A key feature of the capacity achieving schemes in these regimes is the joint decoding of both users' codewords, which we accomplish by performing a posteriori probability calculation over a combined trellis. The schemes are shown to perform close to the capacity limit with low error rate.

  13. P2P overlay over Simctl

    OpenAIRE

    Sicart López, Gerard Carles

    2016-01-01

    This project intends to find and implement a p2p overlay over the simctl platform. Simctl is used both for teaching and research in the network engineering department. P2P systems became an interesting area since early 2000. Researchers conducted a large amount of research in some challenging areas and, to check their experiments, several implementations and simulators were created. Over time, Internet has evolved and P2P has been widely used for file sharing, but the main structured P2P o...

  14. A novel antibody overlay technique for two-dimensional immunoelectrophoresis.

    Science.gov (United States)

    Lebecq, J C; Salhi, S L; Bastide, J M

    1984-02-10

    A new antibody overlay technique for 2-dimensional immunoelectrophoresis (2-D-IEP) is described. After the first dimension electrophoresis of the antigen, the desired amount of antiserum is applied to the initial agarose layer and then evenly distributed over a defined surface of the gel with a PVC film. This modification of the conventional 2-D-IEP procedure makes it possible to perform tandem 2-D-IEPs comparing 2 antisera on the same gel plate, rocket IEPs where several antisera are compared by electrophoresis on the same gel plate, and 2-D-IEPs with an intermediate antiserum, avoiding the need to pour an intermediate gel. With this technique, 77 antigens have been demonstrated in a Candida albicans serotype A somatic antigen preparation. This is the first description of such a large number of immunoprecipitates on the same immunoplate.

  15. Overlay Share Mesh for Interactive Group Communication with High Dynamic

    Institute of Scientific and Technical Information of China (English)

    WU Yan-hua; CAI Yun-ze; XU Xiao-ming

    2007-01-01

    An overlay share mesh infrastructure is presented for high dynamic group communication systems, such as distributed interactive simulation (DIS) and distributed virtual environments (DVE). Overlay share mesh infrastructure can own better adapting ability for high dynamic group than tradition multi-tree multicast infrastructure by sharing links among different groups. The mechanism of overlay share mesh based on area of interest (AOI) was discussed in detail in this paper. A large number of simulation experiments were done and the permance of mesh infrastructure was studied. Experiments results proved that overlay mesh infrastructure owns better adaptability than traditional multi-tree infrastructure for high dynamic group communication systems.

  16. Real cell overlay measurement through design based metrology

    Science.gov (United States)

    Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

    2014-04-01

    Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

  17. Hybrid overlay metrology with CDSEM in a BEOL patterning scheme

    Science.gov (United States)

    Leray, Philippe; Jehoul, Christiane; Inoue, Osamu; Okagawa, Yutaka

    2015-03-01

    Overlay metrology accuracy is a major concern for our industry. Advanced logic process require more tighter overlay control for multipatterning schemes. TIS (Tool Induced Shift) and WIS (Wafer Induced Shift) are the main issues for IBO (Image Based Overlay) and DBO (Diffraction Based Overlay). Methods of compensation have been introduced, some are even very efficient to reduce these measured offsets. Another related question is about the overlay target designs. These targets are never fully representative of the design rules, strong efforts have been achieved, but the device cannot be completely duplicated. Ideally, we would like to measure in the device itself to verify the real overlay value. Top down CDSEM can measure critical dimensions of any structure, it is not dependent of specific target design. It can also measure the overlay errors but only in specific cases like LELE (Litho Etch Litho Etch) after final patterning. In this paper, we will revisit the capability of the CDSEM at final patterning by measuring overlay in dedicated targets as well as inside a logic and an SRAM design. In the dedicated overlay targets, we study the measurement differences between design rules gratings and relaxed pitch gratings. These relaxed pitch which are usually used in IBO or DBO targets. Beyond this "simple" LELE case, we will explore the capability of the CDSEM to measure overlay even if not at final patterning, at litho level. We will assess the hybridization of DBO and CDSEM for reference to optical tools after final patterning. We will show that these reference data can be used to validate the DBO overlay results (correctables and residual fingerprints).

  18. Community overlays upon real-world complex networks

    NARCIS (Netherlands)

    Ge, X.; Wang, H.

    2012-01-01

    Many networks are characterized by the presence of communities, densely intra-connected groups with sparser inter-connections between groups. We propose a community overlay network representation to capture large-scale properties of communities. A community overlay Go can be constructed upon a netwo

  19. Multi-level Reconfigurable Self-organization in Overlay Services

    NARCIS (Netherlands)

    Pournaras, E.

    2013-01-01

    Large-scale decentralized systems organized in overlay networks are complex to manage. Such systems integrate organizational complexity in the application-level resulting in low abstraction and modularity in their services. This thesis introduces a multi-level conceptual architecture for overlay

  20. Community overlays upon real-world complex networks

    NARCIS (Netherlands)

    Ge, X.; Wang, H.

    2012-01-01

    Many networks are characterized by the presence of communities, densely intra-connected groups with sparser inter-connections between groups. We propose a community overlay network representation to capture large-scale properties of communities. A community overlay Go can be constructed upon a

  1. Strategic intelligence on emerging technologies: Scientometric overlay mapping

    NARCIS (Netherlands)

    Rotolo, D.; Rafols, I.; Hopkins, M.M.; Leydesdorff, L.

    This paper examines the use of scientometric overlay mapping as a tool of “strategic intelligence” to aid the governing of emerging technologies. We develop an integrative synthesis of different overlay mapping techniques and associated perspectives on technological emergence across geographical,

  2. EOS: Evolutionary Overlay Service in Peer-to-Peer Systems

    Directory of Open Access Journals (Sweden)

    L. I. Zhijun

    2005-01-01

    Full Text Available The peer-to-peer (P2P systems nowadays can be mainly classified into two categories: structured and structure-less systems based on their overlay organization. The structured systems can achieve determinate efficiency due to their rigorous structure with the cost of losing robustness and vice versa. We provide a semi-structured overlay based on the separation of routing structures and overlay organizations in this paper and the new overlay can achieve determinate efficiency with high robustness. Moreover, the performance of the existing overlay is determined by the initial design and the overlay can not evolve with the information collected. But the new overlay devised in this paper is evolutionary inherent and accompanied by evolving service (EOS, EOS can improve the performance with the running of the P2P systems. Finally, our evolutionary overlay structure is constructed on the basis of linear algebra. So, the EOS can be theoretically analyzed and the results indicate that EOS can work with preferable integrated performance. The experimental results gained on the simulative platform verify the performance of EOS further.

  3. Finite elements simulation of reflective cracking in asphaltic overlays

    NARCIS (Netherlands)

    Scarpas, A.; De Bondt, A.H.

    1996-01-01

    Overlaying is one of the most popular and cost effective techniques of rehabilitation of cracked pavements. The placing of reinforcement between the overlay and the top layer of the cracked pavement is currently being utilised as a possible technique for delaying the development of cracks into the o

  4. Diffraction-based overlay metrology for double patterning technologies

    Science.gov (United States)

    Dasari, Prasad; Korlahalli, Rahul; Li, Jie; Smith, Nigel; Kritsun, Oleg; Volkman, Cathy

    2009-03-01

    The extension of optical lithography to 32nm and beyond is made possible by Double Patterning Techniques (DPT) at critical levels of the process flow. The ease of DPT implementation is hindered by increased significance of critical dimension uniformity and overlay errors. Diffraction-based overlay (DBO) has shown to be an effective metrology solution for accurate determination of the overlay errors associated with double patterning [1, 2] processes. In this paper we will report its use in litho-freeze-litho-etch (LFLE) and spacer double patterning technology (SDPT), which are pitch splitting solutions that reduce the significance of overlay errors. Since the control of overlay between various mask/level combinations is critical for fabrication, precise and accurate assessment of errors by advanced metrology techniques such as spectroscopic diffraction based overlay (DBO) and traditional image-based overlay (IBO) using advanced target designs will be reported. A comparison between DBO, IBO and CD-SEM measurements will be reported. . A discussion of TMU requirements for 32nm technology and TMU performance data of LFLE and SDPT targets by different overlay approaches will be presented.

  5. Multi-level Reconfigurable Self-organization in Overlay Services

    NARCIS (Netherlands)

    Pournaras, E.

    2013-01-01

    Large-scale decentralized systems organized in overlay networks are complex to manage. Such systems integrate organizational complexity in the application-level resulting in low abstraction and modularity in their services. This thesis introduces a multi-level conceptual architecture for overlay ser

  6. Multi-level Reconfigurable Self-organization in Overlay Services

    NARCIS (Netherlands)

    Pournaras, E.

    2013-01-01

    Large-scale decentralized systems organized in overlay networks are complex to manage. Such systems integrate organizational complexity in the application-level resulting in low abstraction and modularity in their services. This thesis introduces a multi-level conceptual architecture for overlay ser

  7. Effect of Colored Overlays on Computer Vision Syndrome (CVS

    Directory of Open Access Journals (Sweden)

    Mark Rosenfield, MCOptom, PhD

    2015-06-01

    Full Text Available Background: Colored overlays may produce an improvement in reading when superimposed over printed materials. This study determined whether improvements in reading occur when the overlays are placed over a computer monitor. Methods: Subjects (N=30 read from a computer screen for 10 minutes with either a Cerium or control overlay positioned on the monitor. In a third condition, no overlay was present. Immediately following each trial, subjects reported ocular and visual symptoms experienced during the task. Results: Mean symptom scores following the Cerium, control, and no overlay conditions were 12.83, 17.37, and 15.65, respectively (p=0.47. However, a subgroup of 7 subjects (23% reported significant improvements with the Cerium overlay. The mean symptom scores for the Cerium, control, and no overlay trials for this subgroup were 12.14, 29.86, and 28.93, respectively (p=0.03. No significant improvements in either reading speed or reading errors were observed in this subgroup. Conclusion: The use of colored overlays may provide a treatment method for some subjects reporting symptoms during computer use.

  8. Solidification paths in modified Inconel 625 weld overlay material

    DEFF Research Database (Denmark)

    Chandrasekaran, Karthik; Tiedje, Niels Skat; Hald, John

    2009-01-01

    Inconel 625 is commonly used for overlay welding to protect the base metal against high temperature corrosion. The efficiency of corrosion protection depends on effective mixing of the overlay weld with the base metal and the subsequent segregation of alloy elements during solidification...

  9. Improving text recognition by distinguishing scene and overlay text

    Science.gov (United States)

    Quehl, Bernhard; Yang, Haojin; Sack, Harald

    2015-02-01

    Video texts are closely related to the content of a video. They provide a valuable source for indexing and interpretation of video data. Text detection and recognition task in images or videos typically distinguished between overlay and scene text. Overlay text is artificially superimposed on the image at the time of editing and scene text is text captured by the recording system. Typically, OCR systems are specialized on one kind of text type. However, in video images both types of text can be found. In this paper, we propose a method to automatically distinguish between overlay and scene text to dynamically control and optimize post processing steps following text detection. Based on a feature combination a Support Vector Machine (SVM) is trained to classify scene and overlay text. We show how this distinction in overlay and scene text improves the word recognition rate. Accuracy of the proposed methods has been evaluated by using publicly available test data sets.

  10. Decentralized Overlay for Federation of Enterprise Clouds

    CERN Document Server

    Ranjan, Rajiv

    2008-01-01

    This chapter describes Aneka-Federation, a decentralized and distributed system that combines enterprise Clouds, overlay networking, and structured peer-to-peer techniques to create scalable wide-area networking of compute nodes for high-throughput computing. The Aneka-Federation integrates numerous small scale Aneka Enterprise Cloud services and nodes that are distributed over multiple control and enterprise domains as parts of a single coordinated resource leasing abstraction. The system is designed with the aim of making distributed enterprise Cloud resource integration and application programming flexible, efficient, and scalable. The system is engineered such that it: enables seamless integration of existing Aneka Enterprise Clouds as part of single wide-area resource leasing federation; self-organizes the system components based on a structured peer-to-peer routing methodology; and presents end-users with a distributed application composition environment that can support variety of programming and execu...

  11. Weld overlay cladding with iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions have limited their use in applications where good weldability is required. Using hot crack testing techniques invented at ORNL, and experimental determinations of preheat and postweld heat treatment needed to avoid cold cracking, we have developed iron aluminide filler metal compositions which can be successfully used to weld overlay clad various substrate materials, including 9Cr-1Mo steel, 2-1/4Cr-1Mo steel, and 300-series austenitic stainless steels. Dilution must be carefully controlled to avoid crack-sensitive deposit compositions. The technique used to produce the current filler metal compositions is aspiration-casting, i.e. drawing the liquid from the melt into glass rods. Future development efforts will involve fabrication of composite wires of similar compositions to permit mechanized gas tungsten arc (GTA) and/or gas metal arc (GMA) welding.

  12. Characterization of waferstepper and process related front- to backwafer overlay errors in bulk micro machining using electrical overlay test structures

    NARCIS (Netherlands)

    Van Zeijl, H.W.; Bijnen, F.G.C.; Slabbekoorn, J.

    2004-01-01

    To validate the Front- To Backwafer Alignment (FTBA) calibration and to investigate process related overlay errors, electrical overlay test structures are used that requires FTBA [1]. Anisotropic KOH etch through the wafer is applied to transfer the backwafer pattern to the frontwafer. Consequently,

  13. Hydrophilic property of SiO2-TiO2 overlayer films and TiO2/SiO2 mixing films

    Institute of Scientific and Technical Information of China (English)

    关凯书; 徐宏; 吕宝君

    2004-01-01

    The photo-induced hydrophilicity of SiO2 overlayer on TiO2 films prepared by sol-gel method was investigated by means of soak angle measurement, XPS, UV-VIS and FTIR spectra. The results show that, compared with the TiO2 film without SiO2 overlayer, when the TiO2 film is thoroughly covered by SiO2 overlayer, the hydrophilicity and the sustained effect are enhanced. It is found that the significant growth of the OH group occurs in the surface of SiO2 overlayer. The different mechanism of enhanced hydrophilicity between SiO2 overlayer on TiO2 films and TiO2/SiO2 mixing films was analyzed. The result suggests that the photo-generated electrons created in the interface between TiO2 and SiO2 tend to reduce the Ti(Ⅳ) cation to the Ti(Ⅲ) state, and the photogenerated holes transmit through the SiO2 layer to uppermost surface efficiently. Once the holes go up to the surface, they tend to make the surface hydrophilic. The stable hydrophilicity of SiO2 overlayer which adsorbs more stable OH groups, enhances the sustained effect, i.e. the super-hydrophilic state can be maintained for a long time in dark place.

  14. Fracture strength of teeth restored with ceramic inlays and overlays.

    Science.gov (United States)

    Morimoto, Susana; Vieira, Glauco Fioranelli; Agra, Carlos Martins; Sesma, Newton; Gil, Carlos

    2009-01-01

    This study evaluated the fracture strength of teeth restored with bonded ceramic inlays and overlays compared to sound teeth. Thirty sound human maxillary premolars were assigned to 3 groups: 1- sound/unprepared (control); 2- inlays and 3- overlays. The inlay cavity design was Class II MOD preparation with an occlusal width of 1/2 of the intercuspal distance. The overlay cavity design was similar to that of the inlay group, except for buccal and palatal cusp coverage The inlay and overlay groups were restored with feldspathic porcelain bonded with adhesive cement. The specimens were subjected to a compressive load until fracture. Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. The fracture strength means (KN) were: Sound/unprepared group = 1.17, Inlay group= 1.17, and Overlay group = 1.14. There were no statistically significant differences (p>0.05) among the groups. For inlays and overlays, the predominant fracture mode involved fragments of one cusp (70% of simple fractures). The fracture strength of teeth restored with inlay and overlay ceramics with cusp coverage was similar to that of intact teeth.

  15. Advanced diffraction-based overlay for double patterning

    Science.gov (United States)

    Li, Jie; Liu, Yongdong; Dasari, Prasad; Hu, Jiangtao; Smith, Nigel; Kritsun, Oleg; Volkman, Catherine

    2010-03-01

    Diffraction based overlay (DBO) technologies have been developed to address the tighter overlay control challenges as the dimensions of integrated circuit continue to shrink. Several studies published recently have demonstrated that the performance of DBO technologies has the potential to meet the overlay metrology budget for 22nm technology node. However, several hurdles must be cleared before DBO can be used in production. One of the major hurdles is that most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. A more advanced spectroscopic ellipsometry (SE) technology-Mueller Matrix SE (MM-SE) is developed to address the challenge. We use a double patterning sample to demonstrate the potential of MM-SE as a DBO candidate. Sample matrix (the matrix that describes the effects of the sample on the incident optical beam) obtained from MM-SE contains up to 16 elements. We show that the Mueller elements from the off-diagonal 2x2 blocks respond to overlay linearly and are zero when overlay errors are absent. This superior property enables empirical DBO (eDBO) using two pads per direction. Furthermore, the rich information in Mueller matrix and its direct response to overlay make it feasible to extract overlay errors from only one pad per direction using modeling approach (mDBO). We here present the Mueller overlay results using both eDBO and mDBO and compare the results with image-based overlay (IBO) and CD-SEM results. We also report the tool induced shifts (TIS) and dynamic repeatability.

  16. A portable image overlay projection device for computer-aided open liver surgery.

    Science.gov (United States)

    Gavaghan, Kate A; Peterhans, Matthias; Oliveira-Santos, Thiago; Weber, Stefan

    2011-06-01

    Image overlay projection is a form of augmented reality that allows surgeons to view underlying anatomical structures directly on the patient surface. It improves intuitiveness of computer-aided surgery by removing the need for sight diversion between the patient and a display screen and has been reported to assist in 3-D understanding of anatomical structures and the identification of target and critical structures. Challenges in the development of image overlay technologies for surgery remain in the projection setup. Calibration, patient registration, view direction, and projection obstruction remain unsolved limitations to image overlay techniques. In this paper, we propose a novel, portable, and handheld-navigated image overlay device based on miniature laser projection technology that allows images of 3-D patient-specific models to be projected directly onto the organ surface intraoperatively without the need for intrusive hardware around the surgical site. The device can be integrated into a navigation system, thereby exploiting existing patient registration and model generation solutions. The position of the device is tracked by the navigation system's position sensor and used to project geometrically correct images from any position within the workspace of the navigation system. The projector was calibrated using modified camera calibration techniques and images for projection are rendered using a virtual camera defined by the projectors extrinsic parameters. Verification of the device's projection accuracy concluded a mean projection error of 1.3 mm. Visibility testing of the projection performed on pig liver tissue found the device suitable for the display of anatomical structures on the organ surface. The feasibility of use within the surgical workflow was assessed during open liver surgery. We show that the device could be quickly and unobtrusively deployed within the sterile environment.

  17. Evaluating the mechanical performance of Very Thin Asphalt Overlay (VTAO as a sustainable rehabilitation strategy in urban pavements

    Directory of Open Access Journals (Sweden)

    M. Sol-Sánchez

    2017-07-01

    Full Text Available Very Thin Asphalt Overlay (VTAO has been introduced as an alternative to traditional thick overlays, seal coats, and micro-surfacings. Nonetheless, there are some challenges that still remain regarding the application of VTAOs (such as mixture type, cohesiveness, wear resistance, cracking and durability, particularly in heavy traffic urban areas. Therefore, this paper presents an extensive comparative evaluation of the mechanical performance, durability and safety issues (cohesiveness, adhesiveness, ageing, cracking, plastic deformation, permeability, macrotexture, skid and wear resistance, and fuel resistance of a VTAO (20 mm thick and a high performance BBTM 11B (35 mm thick, commonly used as an open-graded mixture for pavement overlays. The results demonstrated that VTAO is an appropriate material for urban pavements as it provides good durability and resistance to the propagation of defects. Nonetheless, further studies are required to improve its behavior under distresses related to plastic deformations and safety properties.

  18. Maxillary and mandibular overlay removable partial dentures for restoration of worn teeth. A three-year follow-up.

    Science.gov (United States)

    Almog, Dov M; Ganddini, Mario R

    2006-01-01

    This clinical report describes the fabrication and a three-year follow-up of maxillary and mandibular cast overlay removable partial dentures for the restoration of severely worn dentition with accompanying loss of vertical dimension of occlusion. The frameworks supported porcelain veneers for esthetics, and metal occlusal surfaces for strength and durability.

  19. Combined conjunctival autograft and overlay amniotic membrane transplantation; a novel surgical treatment for pterygium.

    Science.gov (United States)

    Ghanavati, Siamak Zarei; Shousha, Mohamed Abou; Betancurt, Carolina; Perez, Victor L

    2014-01-01

    The authors report the long-term results of combined conjunctival autograft and overlay amniotic membrane transplantation (AMT) for treatment of pterygium as a new surgical technique. Nineteen patients including 12 male and 7 female subjects with pterygium (primary, 14 cases; recurrent, 5 cases) underwent combined conjunctival autograft and overlay AMT and were followed from 10 to 26 months. Mean age was 44.21±12.49 (range, 29.0-73.0) years. In one patient with grade T3 primary pterygium, the lesion recurred (5.2%, recurrence rate). No intra-and postoperative complication developed. This procedure seems a safe and effective surgical technique for pterygium treatment. Protection of the ocular surface during the early postoperative period reduces the friction-induced inflammation and might be helpful to prevent the recurrence.

  20. The Interplanetary Overlay Networking Protocol Accelerator

    Science.gov (United States)

    Pang, Jackson; Torgerson, Jordan L.; Clare, Loren P.

    2008-01-01

    A document describes the Interplanetary Overlay Networking Protocol Accelerator (IONAC) an electronic apparatus, now under development, for relaying data at high rates in spacecraft and interplanetary radio-communication systems utilizing a delay-tolerant networking protocol. The protocol includes provisions for transmission and reception of data in bundles (essentially, messages), transfer of custody of a bundle to a recipient relay station at each step of a relay, and return receipts. Because of limitations on energy resources available for such relays, data rates attainable in a conventional software implementation of the protocol are lower than those needed, at any given reasonable energy-consumption rate. Therefore, a main goal in developing the IONAC is to reduce the energy consumption by an order of magnitude and the data-throughput capability by two orders of magnitude. The IONAC prototype is a field-programmable gate array that serves as a reconfigurable hybrid (hardware/ firmware) system for implementation of the protocol. The prototype can decode 108,000 bundles per second and encode 100,000 bundles per second. It includes a bundle-cache static randomaccess memory that enables maintenance of a throughput of 2.7Gb/s, and an Ethernet convergence layer that supports a duplex throughput of 1Gb/s.

  1. Weld overlay cladding with iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    The author has established a range of compositions for these alloys within which hot cracking resistance is very good, and within which cold cracking can be avoided in many instances by careful control of welding conditions, particularly preheat and postweld heat treatment. For example, crack-free butt welds have been produced for the first time in 12-mm thick wrought Fe{sub 3}Al plate. Cold cracking, however, still remains an issue in many cases. The author has developed a commercial source for composite weld filler metals spanning a wide range of achievable aluminum levels, and are pursuing the application of these filler metals in a variety of industrial environments. Welding techniques have been developed for both the gas tungsten arc and gas metal arc processes, and preliminary work has been done to utilize the wire arc process for coating of boiler tubes. Clad specimens have been prepared for environmental testing in-house, and a number of components have been modified and placed in service in operating kraft recovery boilers. In collaboration with a commercial producer of spiral weld overlay tubing, the author is attempting to utilize the new filler metals for this novel application.

  2. Government Districts, Other - MO 2014 Springfield Conditional Overlay Districts (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Conditional Overlay District polygons for the City of Springfield, inside city limits only. Created and maintained by the GIS Division of the Information Systems...

  3. Zoning Districts - MO 2011 Springfield Conditional Overlay Districts (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Conditional Overlay District polygons for the City of Springfield, inside city limits only. Created and maintained by the GIS Division of the Information Systems...

  4. Hastelloy C-276Weld Overlay bySMAW Process

    National Research Council Canada - National Science Library

    Er. Rahul Sharma; Er. Manoj Kumar; Dr. Abhishek Kamboj

    2017-01-01

    ... diameter.Hastelloy C-276weld overlay on ferrous material is developed for outstanding resistance to wide variety of chemical process environments such as ferric and cupric chlorides, hot contaminated mineral...

  5. nowCOAST's Map Service for Political Map Overlays

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST map service provides map overlays depicting the boundaries of U.S. states, territories, counties and townships/county subdivisions,...

  6. SPHERE: a scalable multicast framework in overlay networks

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presents Sphere, a scalable multicast framework in overlay network. Sphere is a highly efficient, self-organizing and robust multicast protocol overlayed on the Internet. The main contributions of this paper are twofold. First, Sphere organizes the control topology of overlay network in two directions: horizontal and vertical. The horizontal meshes are used to locate and organize hosts in tracks, and the vertical meshes are used to manage the data paths between tracks. Second, Sphere balances stress and stretch of the overlay network by assigning hosts into different tracks and clusters. This structure distributes stress on the multicast trees uniformly, and meantime makes path stretch as small as possible.Simulations results show that Sphere can support multicast with large group size and has good performance on organizing meshes and building data delivery trees.

  7. Augmenting reality in Direct View Optical (DVO) overlay applications

    Science.gov (United States)

    Hogan, Tim; Edwards, Tim

    2014-06-01

    The integration of overlay displays into rifle scopes can transform precision Direct View Optical (DVO) sights into intelligent interactive fire-control systems. Overlay displays can provide ballistic solutions within the sight for dramatically improved targeting, can fuse sensor video to extend targeting into nighttime or dirty battlefield conditions, and can overlay complex situational awareness information over the real-world scene. High brightness overlay solutions for dismounted soldier applications have previously been hindered by excessive power consumption, weight and bulk making them unsuitable for man-portable, battery powered applications. This paper describes the advancements and capabilities of a high brightness, ultra-low power text and graphics overlay display module developed specifically for integration into DVO weapon sight applications. Central to the overlay display module was the development of a new general purpose low power graphics controller and dual-path display driver electronics. The graphics controller interface is a simple 2-wire RS-232 serial interface compatible with existing weapon systems such as the IBEAM ballistic computer and the RULR and STORM laser rangefinders (LRF). The module features include multiple graphics layers, user configurable fonts and icons, and parameterized vector rendering, making it suitable for general purpose DVO overlay applications. The module is configured for graphics-only operation for daytime use and overlays graphics with video for nighttime applications. The miniature footprint and ultra-low power consumption of the module enables a new generation of intelligent DVO systems and has been implemented for resolutions from VGA to SXGA, in monochrome and color, and in graphics applications with and without sensor video.

  8. Mixing materials within zone boundaries using shape overlays

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, J.

    1997-04-22

    Shape overlays provide a means of statically imposing a physical region containing specified material properties onto a zoned mesh. In the most general case, material interface boundaries are unrelated to mesh zone boundaries, causing zones to contain a mixture of materials, and the mesh itself is not uniform in physical space. We develop and apply an algorithm for shape overlays on nonorthogonal, nonuniform meshes in two dimensions. Examples of shape generation in a multiblock uid dynamics code are shown.

  9. Robust overlay metrology with differential Mueller matrix calculus.

    Science.gov (United States)

    Chen, Xiuguo; Gu, Honggang; Jiang, Hao; Zhang, Chuanwei; Liu, Shiyuan

    2017-04-17

    Overlay control is of vital importance to good device performances in semiconductor manufacturing. In this work, the differential Mueller matrix calculus is introduced to investigate the Mueller matrices of double-patterned gratings with overlay displacements, which helps to reveal six elementary optical properties hidden in the Mueller matrices. We find and demonstrate that, among these six elementary optical properties, the linear birefringence and dichroism, LB' and LD', along the ± 45° axes show a linear response to the overlay displacement and are zero when the overlay displacement is absent at any conical mounting. Although the elements from the two 2 × 2 off-diagonal blocks of the Mueller matrix have a similar property to LB' and LD', as reported in the literature, we demonstrate that it is only valid at a special conical mounting with the plane of incidence parallel to grating lines. The better property of LB' and LD' than the Mueller matrix elements of the off-diagonal blocks in the presence of overlay displacement verifies them to be a more robust indicator for the diffraction-based overlay metrology.

  10. Interplanetary Overlay Network Bundle Protocol Implementation

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

  11. A theoretical study of symmetry-breaking organic overlayers on single- and bi-layer graphene

    Science.gov (United States)

    Morales-Cifuentes, Josue; Einstein, T. L.

    2013-03-01

    An ``overlayer'' of molecules that breaks the AB symmetry of graphene can produce (modify) a band gap in single- (bi-) layer graphene.[2] Since the triangular shaped trimesic acid (TMA) molecule forms two familiar symmetry breaking configurations, we are motivated to model TMA physisorption on graphene surfaces in conjunction with experiments by Groce et al. at UMD. Using VASP, with ab initio van der Waals density functionals (vdW-DF), we simulate adsorption of TMA onto a graphene surface in several symmetry-breaking arrangements in order to predict/understand the effect of TMA adsorption on experimental observables. Supported by NSF-MRSEC Grant DMR 05-20471.

  12. The Corrosion and Corrosion Fatigue Behavior of Nickel Based Alloy Weld Overlay and Coextruded Claddings

    Science.gov (United States)

    Stockdale, Andrew

    The use of low NOx boilers in coal fired power plants has resulted in sulfidizing corrosive conditions within the boilers and a reduction in the service lifetime of the waterwall tubes. As a solution to this problem, Ni-based weld overlays are used to provide the necessary corrosion resistance however; they are susceptible to corrosion fatigue. There are several metallurgical factors which give rise to corrosion fatigue that are associated with the localized melting and solidification of the weld overlay process. Coextruded coatings offer the potential for improved corrosion fatigue resistance since coextrusion is a solid state coating process. The corrosion and corrosion fatigue behavior of alloy 622 weld overlays and coextruded claddings was investigated using a Gleeble thermo-mechanical simulator retrofitted with a retort. The experiments were conducted at a constant temperature of 600°C using a simulated combustion gas of N2-10%CO-5%CO2-0.12%H 2S. An alternating stress profile was used with a minimum tensile stress of 0 MPa and a maximum tensile stress of 300 MPa (ten minute fatigue cycles). The results have demonstrated that the Gleeble can be used to successfully simulate the known corrosion fatigue cracking mechanism of Ni-based weld overlays in service. Multilayer corrosion scales developed on each of the claddings that consisted of inner and outer corrosion layers. The scales formed by the outward diffusion of cations and the inward diffusion of sulfur and oxygen anions. The corrosion fatigue behavior was influenced by the surface finish and the crack interactions. The initiation of a large number of corrosion fatigue cracks was not necessarily detrimental to the corrosion fatigue resistance. Finally, the as-received coextruded cladding exhibited the best corrosion fatigue resistance.

  13. Further beyond: registration and overlay control enhancements for optical masks

    Science.gov (United States)

    Gorhad, Kujan; Cohen, Avi; Avizemer, Dan; Dmitriev, Vladimir; Beyer, Dirk; Degel, Wolfgang; Kirsch, Markus

    2014-10-01

    Mask registration control is one of the key performance specifications during the mask qualification process. It is becoming an important factor for yield improvement with the continuously tightening registration specs driven by tight wafer overlay specs. Understanding the impact of miss classified masks on the final wafer yield is gaining more and more attention, especially with the appearance of Multiple Patterning Technologies, where mask to mask overlay effect on wafer is heavily influenced by mask registration. ZEISS has established a promising closed loop solution implemented in the mask house, where the PROVE® system - a highly accurate mask registration and overlay metrology measurement tool, is being used to feed the RegC® - a registration and mask to mask overlay correction tool that can also accurately predict the correction potential in advance. The well-established RegC® process typically reaches 40-70% improvement of the mask registration/overlay error standard deviation. The PROVE® - RegC® closed loop solution has several advantages over alternative registration control methods apart of the mask re-write saving. Among the advantages is the capability to correct for pellicle mounting registration effects without the need to remove the pellicle. This paper will demonstrate improved method for enhanced mask to mask overlay control based on a new scheme of data acquisition and performance validation by the PROVE®. The mask registration data as well as additional mask information will be used to feed the RegC® correction process. Significantly improved mask to mask overlay correction results will be discussed and presented in details.

  14. Initial experience with circumferential pulmonary vein isolation guided by Overlay Ref and CartoMerge in the treatment of paroxysmal atrial fibrillation.

    Science.gov (United States)

    Tang, Kai; Zhao, Dong-dong; Zhang, Jing-ying; Chen, Yan-qing; Xu, Ya-wei

    2010-05-20

    CartoMerge has been widely used in guiding circumferential pulmonary vein isolation (CPVI) for the treatment of paroxysmal atrial fibrillation (PAF). However, the procedure of landmarks selection varies among operators according to their experience. Techniques have to be established to standardize this procedure. We propose that Overlay Ref could facilitate this procedure. This paper aimed to report our initial experience with CPVI guided by Overlay Ref and CartoMerge for the treatment of PAF. Fifty-nine patients with PAF were enrolled in this study. Using Overlay Ref technique, a reference image (inverted) was faded into the live fluoroscopic image. Landmarks of CartoMerge were selected from anatomic points of the top of superior pulmonary veins (PVs) and the bottom of inferior PVs guided by Overlay Ref image. Overlay Ref images were also used to guide the ablation procedure combining with CartoMerge. All patients were successfully mapped by CartoMerge guided by Overlay Ref. The distance between the mapping points and the CT surfaces was (1.42 +/- 0.67) mm for the patients as a whole. This led to a successful rate of 96% for isolation of pulmonary veins. Duration of ablation procedure was (92 +/- 17) minutes. And the total duration of procedure was (139 +/- 32) minutes. CartoMerge could also be performed just with 3 paries to 4 paries selected landmarks guided by Overlay Ref without a full anatomic model constructed by Carto. Then, the total duration of procedure could be shortened to (115 +/- 38) minutes. Overlay Ref technique can facilitate the catheter ablation of PAF and can help to standardize the procedure of landmarks selection.

  15. Initial experience with circumferential pulmonary vein isolation guided by Overlay Ref and CartoMerge in the treatment of paroxysmal atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    TANG Kai; ZHAO Dong-dong; ZHANG Jing-ying; CHEN Yan-qing; XU Ya-wei

    2010-01-01

    Background CartoMerge has been widely used in guiding circumferential pulmonary vein isolation (CPVI) for the treatment of paroxysmal atrial fibrillation (PAF).However, the procedure of landmarks selection varies among operators according to their experience.Techniques have to be established to standardize this procedure.We propose that Overlay Ref could facilitate this procedure.This paper aimed to report our initial experience with CPVI guided by Overlay Ref and CartoMerge for the treatment of PAF.Methods Fifty-nine patients with PAF were enrolled in this study.Using Overlay Ref technique, a reference image (inverted) was faded into the live fluoroscopic image.Landmarks of CartoMerge were selected from anatomic points of the top of superior pulmonary veins (PVs) and the bottom of inferior PVs guided by Overlay Ref image.Overlay Ref images were also used to guide the ablation procedure combining with CartoMerge.Results All patients were successfully mapped by CartoMerge guided by Overlay Ref.The distance between the mapping points and the CT surfaces was (1.42±0.67) mm for the patients as a whole.This led to a successful rate of 96%for isolation of pulmonary veins.Duration of ablation procedure was (92±17) minutes.And the total duration of procedure was (139±32) minutes.CartoMerge could also be performed just with 3 paries to 4 paries selected landmarks guided by Overlay Ref without a full anatomic model constructed by Carto.Then, the total duration of procedure could be shortened to (115±38) minutes.Conclusions Overlay Ref technique can facilitate the catheter ablation of PAF and can help to standardize the procedure of landmarks selection.

  16. Location-Aware Cross-Layer Design Using Overlay Watermarks

    Directory of Open Access Journals (Sweden)

    Xianbin Wang

    2007-01-01

    Full Text Available A new orthogonal frequency division multiplexing (OFDM system embedded with overlay watermarks for location-aware cross-layer design is proposed in this paper. One major advantage of the proposed system is the multiple functionalities the overlay watermark provides, which includes a cross-layer signaling interface, a transceiver identification for position-aware routing, as well as its basic role as a training sequence for channel estimation. Wireless terminals are typically battery powered and have limited wireless communication bandwidth. Therefore, efficient collaborative signal processing algorithms that consume less energy for computation and less bandwidth for communication are needed. Transceiver aware of its location can also improve the routing efficiency by selective flooding or selective forwarding data only in the desired direction, since in most cases the location of a wireless host is unknown. In the proposed OFDM system, location information of a mobile for efficient routing can be easily derived when a unique watermark is associated with each individual transceiver. In addition, cross-layer signaling and other interlayer interactive information can be exchanged with a new data pipe created by modulating the overlay watermarks. We also study the channel estimation and watermark removal techniques at the physical layer for the proposed overlay OFDM. Our channel estimator iteratively estimates the channel impulse response and the combined signal vector from the overlay OFDM signal. Cross-layer design that leads to low-power consumption and more efficient routing is investigated.

  17. Investigation on reticle heating effect induced overlay error

    Science.gov (United States)

    Lim, Mijung; Kim, Geunhak; Kim, SeoMin; Lee, Byounghoon; Kim, Seokkyun; Lim, Chang-moon; Kim, Myoungsoo; Park, Sungki

    2014-04-01

    As design rule of semiconductor decreases continuously, overlay error control gets more and more important and challenging. It is also true that On Product Overlay (OPO) of leading edge memory device shows unprecedented level of accuracy, owing to the development of precision optics, mechanic stage and alignment system with active compensation method. However, the heating of reticle and lens acts as a dominant detriment against further improvement of overlay. Reticle heating is more critical than lens heating in current advanced scanners because lens heating can be mostly compensated by feed-forward control algorithm. In recent years, the tools and technical ideas for reticle heating control are proposed and thought to reduce the reticle heating effect. Nevertheless, it is not still simple to predict the accurate heating amount and overlay. And it is required to investigate the parameters affecting reticle heating quantitatively. In this paper, the reticle pattern density and exposure dose are considered as the main contributors, and the effects are investigated through experiments. Mask set of various transmittance are prepared by changing pattern density. After exposure with various doses, overlay are measured and analyzed by comparing with reference marks exposed in heating free condition. As a result, it is discovered that even in the case of low dose and high transmittance, reticle heating is hardly avoidable. It is also shown that there is a simple relationship among reticle heating, transmittance and exposure dose. Based on this relationship, the reticle heating is thought to be predicted if the transmittance and dose are fixed.

  18. Overlay metrology solutions in a triple patterning scheme

    Science.gov (United States)

    Leray, Philippe; Mao, Ming; Baudemprez, Bart; Amir, Nuriel

    2015-03-01

    Overlay metrology tool suppliers are offering today several options to their customers: Different hardware (Image Based Overlay or Diffraction Based Overlay), different target designs (with or without segmentation) or different target sizes (from 5 um to 30 um). All these variations are proposed to resolve issues like robustness of the target towards process variations, be more representative of the design or increase the density of measurements. In the frame of the development of a triple patterning BEOL scheme of 10 nm node layer, we compare IBO targets (standard AIM, AIMid and multilayer AIMid). The metrology tools used for the study are KLA-Tencor's nextgeneration Archer 500 system (scatterometry- and imaging-based measurement technologies on the same tool). The overlay response and fingerprint of these targets will be compared using a very dense sampling (up to 51 pts per field). The benefit of indie measurements compared to the traditional scribes is discussed. The contribution of process effects to overlay values are compared to the contribution of the performance of the target. Different targets are combined in one measurement set to benefit from their different strengths (performance vs size). The results are summarized and possible strategies for a triple patterning schemes are proposed.

  19. EXPERIENCE WITH OVERLAY TYMPANOPLASTY IN 83 CHINESE PATIENTS

    Institute of Scientific and Technical Information of China (English)

    PENG Bengang; MIAO Xutao; WANG Xin; ZHU Sixiang; SUN Yiqing

    2014-01-01

    Background In many European and American hospitals, represented by the House Ear Clinic (HEC), the overlay tympanoplasty is used with rare exception, with simultaneous canal wall up or down mastoidectomy being taken if needed. In China, underlay tympanoplasty is used across the country, but the overlay tech-nique is used rarely. The aim of the current study was to report the authors’experience with overlay tympa-noplasty in 83 Chinese patients and study its value. Methods Eight-three patients (86 ears) underwent over-lay tympanoplasty in accordance to the standard of the HEC. The patients were followed up and conditions of the external auditory canal, tympanic membrane and hearing were reviewed and analyzed. Results All patients gained stage I incision healing. The size of external auditory canal and tympanic membrane mor-phology were satisfactory. Hearing either remained unchanged or improved. There were no hearing deterio-ration or serious complications. Conclusions Overlay tympanoplasty carries positive value in treating chron-ic otitis media and cholesteatoma with the merits of procedure standardization, adequate operative exposure, thorough disease elimination and extensive adaptation.

  20. High-order distortion control using a computational prediction method for device overlay

    Science.gov (United States)

    Kang, Young-Seog; Affentauschegg, Cedric; Mulkens, Jan; Kim, Jang-Sun; Shin, Ju-Hee; Kim, Young-Ha; Nam, Young-Sun; Choi, Young-Sin; Ha, Hunhwan; Lee, Dong-Han; Lee, Jae-il; Rizvi, Umar; Geh, Bernd; van der Heijden, Rob; Baselmans, Jan; Kwon, Oh-Sung

    2016-04-01

    As a result of the continuously shrinking features of the integrated circuit, the overlay budget requirements have become very demanding. Historically, overlay has been performed using metrology targets for process control, and most overlay enhancements were achieved by hardware improvements. However, this is no longer sufficient, and we need to consider additional solutions for overlay improvements in process variation using computational methods. In this paper, we present the limitations of third-order intrafield distortion corrections based on standard overlay metrology and propose an improved method which includes a prediction of the device overlay and corrects the lens aberration fingerprint based on this prediction. For a DRAM use case, we present a computational approach that calculates the overlay of the device pattern using lens aberrations as an additional input, next to the target-based overlay measurement result. Supporting experimental data are presented that demonstrate a significant reduction of the intrafield overlay fingerprint.

  1. Enhanced interfacial adhesion and osteogenesis for rapid "bone-like" biomineralization by PECVD-based silicon oxynitride overlays.

    Science.gov (United States)

    Ilyas, Azhar; Lavrik, Nickolay V; Kim, Harry K W; Aswath, Pranesh B; Varanasi, Venu G

    2015-07-22

    Structurally unstable fracture sites require metal fixative devices, which have long healing times due to their lack of osteoinductivity. Bioactive glass coatings lack in interfacial bonding, delaminate, and have reduced bioactivity due to the high temperatures used for their fabrication. Here, we test the hypothesis that low-temperature PECVD amorphous silica can enhance adhesion to the underlying metal surface and that N incorporation enhances osteogenesis and rapid biomineralization. A model Ti/TiO2-SiOx interface was formed by first depositing Ti onto Si wafers, followed by surface patterning, thermal annealing to form TiO2, and depositing SiOx/Si(ON)x overlays. TEM micrographs showed conformal SiOx layers on Ti/TiO2 overlays while XPS data revealed the formation of an elemental Ti-O-Si interface. Nanoscratch testing verified strong SiOx bonding with the underlying TiO2 layers. In vitro studies showed that the surface properties changed significantly to reveal the formation of hydroxycarbonate apatite within 6 h, and Si(ON)x surface chemistry induced osteogenic gene expression of human periosteal cells and led to a rapid "bone-like" biomineral formation within 4 weeks. XANES data revealed that the incorporation of N increased the surface HA bioactivity by increasing the carbonate to phosphate ratio. In conclusion, silicon oxynitride overlays on bone-implant systems enhance osteogenesis and biomineralization via surface nitrogen incorporation.

  2. Tensile Characteristics of Bond of Stainless Steel Overlay Weld after Absorption of Hydrogen : Study on a Stainless Steel Overlay Welding Process for Superior Resistance to Disbonding (Report 4)

    OpenAIRE

    Akiyoshi, FUJI; Etsuo, KUDO; Tomoyuki, TAKAHASHI; The Japan Steel Works, Ltd., Muroran Plant

    1987-01-01

    The tensile characteristics of the bond of the disbanding-resistant overlay weld after absorption of hydrogen were studied and compared with those of the conventional overlay weld. It was found that the tensile strength of the bond of the conventional overlay weld was lower than that of the disbanding-resistant overlay weld. This is due to existence of the coarse planar grains in first layer overlay weld metal adjacent to the bond. The coarse planar grains strongly reduce the resistance to hy...

  3. Cooperative Resource Pricing in Service Overlay Networks for Mobile Agents

    Science.gov (United States)

    Nakano, Tadashi; Okaie, Yutaka

    The success of peer-to-peer overlay networks depends on cooperation among participating peers. In this paper, we investigate the degree of cooperation among individual peers required to induce globally favorable properties in an overlay network. Specifically, we consider a resource pricing problem in a market-oriented overlay network where participating peers sell own resources (e.g., CPU cycles) to earn energy which represents some money or rewards in the network. In the resource pricing model presented in this paper, each peer sets the price for own resource based on the degree of cooperation; non-cooperative peers attempt to maximize their own energy gains, while cooperative peers maximize the sum of own and neighbors' energy gains. Simulation results are presented to demonstrate that the network topology is an important factor influencing the minimum degree of cooperation required to increase the network-wide global energy gain.

  4. Structural Design of Pavement Overlays Based on Functional Parameters

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper reports a practical pavement overlay design methodbased on PCI (Pavement Condition Index). Current pavement investigation method (JTJ 073-96) is compared to the ASTM D 5340, which is the standard test method for airport pavement condition evaluation initially developed for US Air Force. The deficiency in the calculation of PCI based on field data in JTJ 073 is discussed. The proposed design method is compared to AASHTO overlay design method with good agreement. The paper concludes with an example illustrating how the existing pavement structural capacity is related to pavement distress survey results. The presented design method can be used in the design for overlay rehabilitation of pavements of highways, urban streets and airports.

  5. A Proactive Tree Recovery Mechanism for Resilient Overlay Multicast

    Directory of Open Access Journals (Sweden)

    Poorna Satyanarayana B.

    2012-06-01

    Full Text Available Overlay multicast constructs a multicast delivery tree among end hosts. An important problem for making overlay multicast more dependable is how to recover from node departures in order to minimize the disruption of service to those affected nodes. In this paper, we propose a proactive tree recovery mechanism to make the overlay multicast resilient to these failures and unexpected events. The salient feature of the approach is that rescue plans for multiple non-leaf nodes can work together for their respective children when they fail or leave at the same time. Extensive simulations demonstrate that our proactive approach can recover from node departures much faster than reactive methods, while the quality of trees restored and the cost of recovery are reasonable

  6. Ductile film delamination from compliant substrates using hard overlayers

    Energy Technology Data Exchange (ETDEWEB)

    Cordill, M.J. [Erich Schmid Institute of Materials Science, Austrian Academy of Sciences (Austria); Marx, V.M.; Kirchlechner, C. [Max-Plank-Insitut für Eisenforschung GmbH, Düsseldorf (Germany)

    2014-11-28

    Flexible electronic devices call for copper and gold metal films to adhere well to polymer substrates. Measuring the interfacial adhesion of these material systems is often challenging, requiring the formulation of different techniques and models. Presented here is a strategy to induce well defined areas of delamination to measure the adhesion of copper films on polyimide substrates. The technique utilizes a stressed overlayer and tensile straining to cause buckle formation. The described method allows one to examine the effects of thin adhesion layers used to improve the adhesion of flexible systems. - Highlights: • Measuring the adhesion energies of ductile metal–polymer interfaces is difficult. • A Cu film would plastically deform under tensile strain without a Cr overlayer. • A Cr overlayer forces cracking and induces buckling between the crack fragments. • The adhesion energy of the metal–polymer interface can be measured.

  7. Using Mobile Agents and Overlay Networks to Secure Electrical Networks

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-02-11

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats.

  8. Using Mobile Agents and Overlay Networks to Secure Electrical Netoworks

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-04-01

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats

  9. Simulated fatigue resistance of composite resin versus porcelain CAD/CAM overlay restorations on endodontically treated molars.

    Science.gov (United States)

    Magne, Pascal; Knezevic, Alena

    2009-02-01

    To assess the influence of material selection (porcelain versus composite resin) for overlay-type restoration of endodontically treated molars and its effect on the in vitro fatigue resistance and failure mode. A standardized tooth preparation was applied to 30 extracted molars, including root canal treatment, 3-mm coverage of all cusps, a mesial box 1.5 mm below the cementoenamel junction (CEJ), a distal box in enamel, a glass-ionomer base, and immediately sealed dentin. Using the Cerec machine (Sirona), all teeth were restored with an overlay of standardized thickness and occlusal anatomy. Fifteen restorations were milled in the ceramic Vita MKII block (Vident) and the other 15 using the composite resin Paradigm MZ100 block (3M ESPE). The intaglio surfaces of the ceramic restorations were etched and silanated. The intaglio surfaces of the composite resin overlays were airborne-particle abraded and silanated. Preparations were airborne-particle abraded and etched before restoration insertion. All restorations were adhesively luted with an adhesive resin (Optibond FL, Kerr) and a light-curing composite resin (Filtek Z100, 3M ESPE). Cyclic isometric chewing (5 Hz) was simulated, starting with a load of 200 N (5,000 cycles), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,000 cycles each. Samples were loaded until fracture or to a maximum of 185,000 cycles. MKII overlays fractured at a mean load of 1,147 N, and none of them withstood all 185,000 loading cycles (survival = 0%); with MZ100, the survival rate was 73%. With MKII, 40% of the fractures ended below the CEJ; with MZ100, only 25% did. Composite resin MZ100 increased the fatigue resistance of overlay-type restorations in endodontically treated molars when compared to porcelain MKII. The efficiency of the bond strategy (immediate dentin sealing) was demonstrated by the absence of adhesive failures.

  10. Comparison between five commonly used two-dimensional methods of human bite mark overlay production from the dental study casts.

    Science.gov (United States)

    Maloth, Saritha; Ganapathy, K S

    2011-01-01

    The present study was conducted to determine the most accurate bite mark overlay fabrication technique by studying two physical characteristics, i.e., area and rotation of biting edges of anterior teeth of thirty volunteers. The objective of the study was to evaluate the reliability and efficacy of five commonly used methods of human bite mark overlays using two dimensional (2D) digital images of dental study casts as a gold standard, to rank different methods according to statistically based determination of relative accuracy of each method and to determine its feasibility in Forensic science. Overlays were produced from the biting surfaces of six upper and six lower anterior teeth of 30 volunteers using the following five methods: a) hand tracing from study casts, b) hand tracing from wax impressions, c) xerographic method, d) radiopaque impression method and e) 2D computer-based method. Area of the biting edges of the anterior teeth and relative rotation of each anterior tooth were measured and compared. The xerographic method was determined to be the more accurate method with respect to tooth area and rotation. Hand tracing methods, from either wax impressions of teeth or directly from study casts, were determined to be inaccurate and subjective. It is recommended that forensic odontologists discontinue the use of hand tracing overlays in bite mark comparison cases as there is lot of scope for manipulation and observer bias.

  11. Field application of phased array ultrasonic testing for structural weld overlay on dissimilar welds of pressurizer nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hoi; Kim, Yong Sik [Korea Hydro and Nuclear Power Company Ltd., Central Research Institute, Daejeon (Korea, Republic of)

    2015-08-15

    Weld overlay was first used in power plants in the US in the early 1980s as an interim method of repairing the welds of flawed piping joints. Weld overlaid piping joints in nuclear power plants must be examined periodically using ultrasonic examination technology. Portable phased array ultrasonic technology has recently become available. Currently, the application of preemptive weld overlays as a mitigation technique and/as a method to improve the examination surface condition for more complex configurations is becoming more common. These complex geometries may require several focused conventional transducers for adequate inspection of the overlay, the original weld, and the base material. Alternatively, Phased array ultrasonic probes can be used to generate several inspection angles simultaneously at various focal depths to provide better and faster coverage than that possible by conventional methods. Thus, this technology can increase the speed of examinations, save costs, and reduce radiation exposure. In this paper, we explain the general sequence of the inspection of weld overlay and the results of signal analysis for some PAUT (phased array ultrasonic testing) signals detected in on-site inspections.

  12. Implementing a Trust Overlay Framework for Digital Ecosystems

    Science.gov (United States)

    Malone, Paul; McGibney, Jimmy; Botvich, Dmitri; McLaughlin, Mark

    Digital Ecosystems, being decentralised in nature, are inherently untrustworthy environments. This is due to the fact that these environments lack a centralised gatekeeper and identity provider. In order for businesses to operate in these environments there is a need for security measures to support accountability and traceability. This paper describes a trust overlay network developed in the OPAALS project to allow entities participating in digital ecosystems to share experience through the exchange of trust values and to leverage on this network to determine reputation based trustworthiness of unknown and initially untrusted entities. An overlay network is described together with sample algorithms and a discussion on implementation.

  13. OVERLAY DENTURES: A REVIEW AND REPORT OF FOUR CASES

    Directory of Open Access Journals (Sweden)

    Deeksha SHARMA

    2013-12-01

    Full Text Available Patients with ectodermal dysplasia or having under‑ gone cleft surgery with anodontia or hypodontia, hypo‑ plastic conical teeth and patients with severely worn dentition are difficult to treat because of the poor remaining tooth structure. These patients often exhibit loss of vertical dimension of occlusion and aesthetic problems and usually need complex prosthetic treatments. Financial constraints or other priorities often restrict one from choosing the most desirable treatment. The overlay removable denture is a covering prosthesis partially supported by natural teeth, tooth roots, or dental implants, providing an efficient alter‑ native of treatment. Clinical reports describe the various applications of overlay dentures.

  14. QUANTIFIED COST-BALANCED ROUTING SCHEME FOR OVERLAY MULTICAST

    Institute of Scientific and Technical Information of China (English)

    Lu Jun; Ruan Qiuqi

    2006-01-01

    This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem between overlay path delay and access bandwidth at Multicast Server Nodes (MSN) for real-time applications over Internet. Besides implementing a dynamic priority to MSNs by weighing the size of its service clients for better efficiency, QCost-Balanced tradeoffs these two metrics by a unified tradeoff metric based on quantitative analysis. Simulation experiments demonstrate that the scheme achieves a better tradeoff gain in both two metrics, and effective performance in metric quantitative control.

  15. Diffraction-based overlay for spacer patterning and double patterning technology

    Science.gov (United States)

    Lee, Byoung Hoon; Park, JeongSu; Lee, Jongsu; Park, Sarohan; Lim, ChangMoon; Yim, Dong-Gyu; Park, Sungki; Ryu, Chan-Ho; Morgan, Stephen; van de Schaar, Maurits; Fuchs, Andreas; Bhattacharyya, Kaustuve

    2011-03-01

    Overlay performance will be increasingly important for Spacer Patterning Technology (SPT) and Double Patterning Technology (DPT) as various Resolution Enhancement Techniques are employed to extend the resolution limits of lithography. Continuous shrinkage of devices makes overlay accuracy one of the most critical issues while overlay performance is completely dependent on exposure tool. Image Based Overlay (IBO) has been used as the mainstream metrology for overlay by the main memory IC companies, but IBO is not suitable for some critical layers due to the poor Tool Induced Shift (TIS) values. Hence new overlay metrology is required to improve the overlay measurement accuracy. Diffraction Based Overlay (DBO) is regarded to be an alternative metrology to IBO for more accurate measurements and reduction of reading errors. Good overlay performances of DBO have been reported in many articles. However applying DBO for SPT and DPT layers poses extra challenges for target design. New vernier designs are considered for different DPT and SPT schemes to meet overlay target in DBO system. In this paper, we optimize the design of the DBO target and the performance of DBO to meet the overlay specification of sub-3x nm devices which are using SPT and DPT processes. We show that the appropriate vernier design yields excellent overlay performance in residual and TIS. The paper also demonstrated the effects of vernier structure on overlay accuracy from SEM analysis.

  16. Metallographic Characteristics of Stainless Steel Overlay Weld with Resistance to Hydrogen-Induced Disbonding : Study on a Stainless Steel Overlay Welding Process for Superior Resistance to Disbonding (Report 3)

    OpenAIRE

    Akiyoshi, FUJI; Etsuo, KUDO; Tomoyuki, TAKAHASHI; The Japan Steel Works, Ltd., Muroran Plant

    1986-01-01

    The metallographic characteristics of the disbanding resistant stainless steel overlay weld were studied and compared with those of the conventional overlay weld. It was found that the first layer overlay weld metal of the disbanding resistant overlay weld consisted of austenite and martensite after regular post-weld heat treatment. A coarse planar grain, which strongly affects the disbanding resistance of over-lay welds, scarcely existed in the disbanding resistant overlay weld. A higher wel...

  17. Coverage dependence of photoemission core levels of alkali-metal overlayers

    Energy Technology Data Exchange (ETDEWEB)

    Sham, T.K.; Shek, M.; Xu, G.; Hrbek, J.

    1989-05-01

    Photoemission from alkali-metal core levels (Li 1s, Na 2s, K 3p, Cs 5p, and 4d) has been studied for different alkali-metal coverages on Ru(001) using synchrotron radiation from the Vacuum Ultraviolet (VUV) ring at the National Synchrotron Light Source (NSLS). The alkali atoms interacting directly with the Ru substrate show coverage-dependent binding-energy shifts towards the Fermi level, with the largest shift for Li (1.1 eV) and the smallest ones for K and Cs. At coverages > 1 monolayer (ML), the core-level shift between the second (surface) and the first (interface) layer is observed in all alkali overlayers. At ''thin'' multilayer coverages (/similar to/3 ML), all alkali overlayers exhibit three sets of core-level photoemission bands which are assigned to the interface, the immediate ''bulk,'' and the surface in increasing binding energy. At coverages >5 ML (''thick'' multilayer) all alkali metals exhibit bulklike properties and surface--atom core-level binding-energy shifts are observed in all cases.

  18. Heavy Vehicle Simulator aided evaluation of overlays on pavements with active cracks

    CSIR Research Space (South Africa)

    Viljoen, AW

    1987-07-01

    Full Text Available Conventional overlay life estimates are often invalidated by the reflection of existing cracks in a pavement through an overlay. This is attributable to a lack of understanding of the factors influencing relative crack movements and their mechanisms...

  19. Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay

    Science.gov (United States)

    Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

    2006-01-01

    In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

  20. 3D Align overlay verification using glass wafers

    NARCIS (Netherlands)

    Smeets, E.M.J.; Bijnen, F.C.G.; Slabbekoorn, J.; Van Zeijl, H.W.

    2004-01-01

    In the MEMS world, increasing attention is being given to 3D devices requiring dual-sided processing. This requires lithography tools that are able to align a wafer to both its back side as front side. Overlay describes how well front and back side layers are positioned with respect to each other. C

  1. Promoting Learning of Instructional Design via Overlay Design Tools

    Science.gov (United States)

    Carle, Andrew Jacob

    2012-01-01

    I begin by introducing Virtual Design Apprenticeship (VDA), a learning model--built on a solid foundation of education principles and theories--that promotes learning of design skills via overlay design tools. In VDA, when an individual needs to learn a new design skill or paradigm she is provided accessible, concrete examples that have been…

  2. Research on overlaying welding rod of high hardness maraging steel

    Institute of Scientific and Technical Information of China (English)

    PAN Yong-ming; CHEN Shao-wei

    2006-01-01

    The development of new maraging steel overlaying welding rod,which contains Co,Mo,W and V alloy,solved the problems of poor homogeneity of hardness and mechanical process, prolonged the service life of wear-resistant components and increased the productive efficiency of repairing,greatly benefiting the national economy.

  3. Loop overlay tympanoplasty for anterior or subtotal perforations.

    Science.gov (United States)

    Lee, Heung-Yeup; Auo, Hyeon-Jin; Kang, Jun-Myung

    2010-04-01

    To report our experience with "loop overlay" tympanoplasty, a modified overlay technique with a superiorly based skin flap, for the reconstruction of anterior, subtotal or total tympanic membrane (TM) perforations. Retrospective review of patients undergoing loop overlay tympanoplasty from March 1998 to February 2007 was performed. Four hundred and twenty-nine patients who underwent loop overlay tympanoplasty and then follow-up visits a minimum of 6 months later were included in this study. Hearing test results were reported using a four-frequency (0.5, 1, 2, and 3kHz) pure tone average air-bone gap. The outcome was considered successful if the TM was intact without lateralization or anterior blunting after the follow-up visit. There was a 98.8% success rate. There was no graft lateralization, anterior blunting, neocholesteatoma, or sensorineural hearing loss. The mean preoperative to postoperative four-tone air-bone gap improved from 23.5 to 8.1dB, which is a mean gain of 15dB; this was statistically significant (poverlay graft method is a safe and effective technique for reconstruction of anterior, subtotal or total TM perforations, with excellent graft take and significant improvement of hearing. It provides a precise replacement of the flap and a preserved healing plane. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  4. Promoting Learning of Instructional Design via Overlay Design Tools

    Science.gov (United States)

    Carle, Andrew Jacob

    2012-01-01

    I begin by introducing Virtual Design Apprenticeship (VDA), a learning model--built on a solid foundation of education principles and theories--that promotes learning of design skills via overlay design tools. In VDA, when an individual needs to learn a new design skill or paradigm she is provided accessible, concrete examples that have been…

  5. Crosslayer Survivability in Overlay-IP-WDM Networks

    Science.gov (United States)

    Pacharintanakul, Peera

    2010-01-01

    As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

  6. Forged seal detection based on the seal overlay metric.

    Science.gov (United States)

    Lee, Joong; Kong, Seong G; Lee, Young-Soo; Moon, Ki-Woong; Jeon, Oc-Yeub; Han, Jong Hyun; Lee, Bong-Woo; Seo, Joong-Suk

    2012-01-10

    This paper describes a method for verifying the authenticity of a seal impression imprinted on a document based on the seal overlay metric, which refers to the ratio of an effective seal impression pattern and the noise in the neighborhood of the reference impression region. A reference seal pattern is obtained by taking the average of a number of high-quality impressions of a genuine seal. A target seal impression to be examined, often on paper with some background texts and lines, is segmented out from the background by an adaptive threshold applied to the histogram of color components. The segmented target seal impression is then spatially aligned with the reference by maximizing the count of matching pixels. Then the seal overlay metric is computed for the reference and the target. If the overlay metric of a target seal is below a predetermined limit for the similarity to the genuine, then the target is classified as a forged seal. To further reduce the misclassification rate, the seal overlay metric is adjusted by the filling rate, which reflects the quality of inked pattern of the target seal. Experiment results demonstrate that the proposed method can detect elaborate seal impressions created by advanced forgery techniques such as lithography and computer-aided manufacturing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. 3D Align overlay verification using glass wafers

    NARCIS (Netherlands)

    Smeets, E.M.J.; Bijnen, F.C.G.; Slabbekoorn, J.; Van Zeijl, H.W.

    2004-01-01

    In the MEMS world, increasing attention is being given to 3D devices requiring dual-sided processing. This requires lithography tools that are able to align a wafer to both its back side as front side. Overlay describes how well front and back side layers are positioned with respect to each other.

  8. Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay

    Science.gov (United States)

    Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

    2006-01-01

    In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

  9. Mapping (USPTO) patent data using overlays to Google Maps

    NARCIS (Netherlands)

    Leydesdorff, L.; Bornmann, L.

    2012-01-01

    A technique is developed using patent information available online (at the U.S. Patent and Trademark Office) for the generation of Google Maps. The overlays indicate both the quantity and the quality of patents at the city level. This information is relevant for research questions in technology anal

  10. Recovery of Sublethally Injured Bacteria Using Selective Agar Overlays.

    Science.gov (United States)

    McKillip, John L.

    2001-01-01

    This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)

  11. Crosslayer Survivability in Overlay-IP-WDM Networks

    Science.gov (United States)

    Pacharintanakul, Peera

    2010-01-01

    As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

  12. 3D Align overlay verification using glass wafers

    NARCIS (Netherlands)

    Smeets, E.M.J.; Bijnen, F.C.G.; Slabbekoorn, J.; Van Zeijl, H.W.

    2004-01-01

    In the MEMS world, increasing attention is being given to 3D devices requiring dual-sided processing. This requires lithography tools that are able to align a wafer to both its back side as front side. Overlay describes how well front and back side layers are positioned with respect to each other. C

  13. Dynamic adaptable overlay networks for personalised service delivery

    NARCIS (Netherlands)

    Mathieu, B.; Stiemerling, M.; Soveri, M.C.; Galis, A.; Jean, K.; Ocampo, R.; Lai, Z.; Kampmann, M.; Tariq, M.A.; Balos, K.; Ahmed, O.K.; Busropan, B.J.; Prins, M.J.

    2007-01-01

    Overlay Networks have been designed as a promising solution to deliver new services via the use of intermediate nodes, acting as proxies or relays. This concept enables to hide the heterogeneity and variability of the underlying networks. In the Ambient Networks (ANs) project, the objectives are to

  14. Insights into the vanadia catalyzed oxidative dehydrogenation of isobutane with CO2%钒氧化物催化CO2氧化异丁烷脱氢的研究

    Institute of Scientific and Technical Information of China (English)

    袁瑞雪; 刘昭铁; 郝郑平; 李杨; 闫浩兵; 王欢; 宋健; 张中申; 樊卫斌; 陈建刚; 刘忠文

    2014-01-01

    采用溶胶-凝胶法制备了一系列钒氧化物催化剂,并用于CO2氧化异丁烷脱氢反应.采用X射线衍射、低温N2吸附-脱附、O2程序升温氧化、程序升温表面反应和原位傅里叶变换红外光谱等方法研究了催化剂的性质.反应结果表明,尽管所有钒氧化物催化剂的丁烯选择性都大于85%,但随着催化剂组成和制备方法的改变,催化活性和稳定性差异显著.其中,12 wt% V2O5/Ce0.6Zr0.4O2(7 wt%)-Al2O3的催化活性最高,而6 wt% V2O5-Ce0.6Zr0.4O2(7 wt%)-Al2O3的稳定性最佳.关联分析催化反应结果与催化剂表征表明,钒氧化物的催化活性取决于VOx物种的结晶度和分散度,而催化剂表面所积重质焦炭的特性是决定催化剂稳定性的关键.非稳态反应和原位光谱结果确认, CO2氧化异丁烷脱氢遵循Mars-van Krevelen氧化还原机理.%Vanadia-based catalysts were prepared using the sol-gel method and were subjected to the oxida-tive dehydrogenation of isobutane with CO2. The materials were extensively characterized by using X-ray diffraction, N2 adsorption-desorption, O2-temperature programmed oxidation, temperature programmed surface reaction, and in situ Fourier transform infrared techniques. Catalytic results indicate that a high selectivity toward total C4 olefins over 85%was obtained over all of the cata-lysts. On the contrary, the highest conversion of isobutane was observed over 12 wt%V2O5/Ce0.6Zr0.4O2(7 wt%)-Al2O3, and a more stable performance was achieved over 6 wt%V2O5-Ce0.6Zr0.4O2(7 wt%)-Al2O3. The catalytic activity for the titled reaction was found to be de-pendent on the dispersion and crystallinity of the VOx species over the catalyst, and the deposition of the heavier coke over the catalyst was revealed to be the main reason for the catalyst deactiva-tion. Moreover, the benefit of CO2 toward the titled reaction was clearly revealed from TPSR results, and the reaction was confirmed to follow the redox mechanism.

  15. Outcomes of the overlay graft technique in tympanoplasty.

    Science.gov (United States)

    Ryan, Jennifer E; Briggs, Robert J S

    2010-09-01

    This audit was undertaken to review the outcomes achieved with the overlay graft technique of tympanic membrane repair in tympanoplasty surgery. The charts of all patients who underwent tympanoplasty, in whom an overlay graft technique of temporalis fascia tympanic membrane repair was used, between 1994 and 2007 were reviewed. Information with respect to patient demographics, presence of cholesteatoma or active infection and perforation size was documented. Details of the surgical procedure and clinical outcomes and pre- and post-operative hearing thresholds were recorded in a computer database. A total of 147 overlay graft procedures were performed in 130 patients. Graft failure with reperforation occurred following five procedures, for an overall success rate of 96.6%. Eighty Type 1 tympanoplasty procedures were performed in which one failure occurred for a 98.75% success rate. Overlay grafting was combined with intact canal wall mastoidectomy (ICW) in 38 cases and with modified radical mastoidectomy (MRM) in 17 cases for a success rate of 93.8 and 95%, respectively. Delayed graft healing as a result of infection, problems such as epithelial pearl, blunting and myringitis occurred in 39 cases (26.5%). Thirty-one cases underwent procedures for ossicular chain reconstruction, 21 of which were 2nd stage procedures. Hearing outcomes were significantly better with Type 1 tympanoplasty compared with ICW or MRM procedures. This review demonstrates the overlay graft technique of tympanoplasty to be highly successful for tympanic membrane repair, particularly for the more difficult cases such as revision surgery, subtotal perforations and mesotympanic cholesteatoma. © 2010 The Authors. ANZ Journal of Surgery © 2010 Royal Australasian College of Surgeons.

  16. Scalable Lunar Surface Networks and Adaptive Orbit Access Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovative network architecture, protocols, and algorithms are proposed for both lunar surface networks and orbit access networks. Firstly, an overlaying...

  17. Adlayer Core-Level Shifts of Random Metal Overlayers on Transition-Metal Substrates

    DEFF Research Database (Denmark)

    Ganduglia-Pirovano, M. V.; Kudrnovský, J.; Scheffler, M.

    1997-01-01

    We calculate the difference of the ionization energies of a core electron of a surface alloy, i.e., a B atom in a A(1-x)B(x) overlayer on a fee B(001) substrate, and a core electron of the clean fee B(001) surface using density-functional theory. We analyze the initial-state contributions and the...... the initial-state trends are explained in terms of the change of inter- and intra-atomic screening upon alloying. A possible role of alloying on the chemical reactivity of metal surfaces is discussed....... and the screening effects induced by the core hole, and study the influence of the alloy composition for a number of noble metal-transition metal systems. Our analysis clearly indicates the importance of final-state screening effects for the interpretation of measured core-level shifts. Calculated deviations from...

  18. Atomistic simulation study of short pulse laser interactions with a metal target under conditions of spatial confinement by a transparent overlayer

    Science.gov (United States)

    Karim, Eaman T.; Shugaev, Maxim; Wu, Chengping; Lin, Zhibin; Hainsey, Robert F.; Zhigilei, Leonid V.

    2014-05-01

    The distinct characteristics of short pulse laser interactions with a metal target under conditions of spatial confinement by a solid transparent overlayer are investigated in a series of atomistic simulations. The simulations are performed with a computational model combining classical molecular dynamics (MD) technique with a continuum description of the laser excitation, electron-phonon equilibration, and electronic heat transfer based on two-temperature model (TTM). Two methods for incorporation of the description of a transparent overlayer into the TTM-MD model are designed and parameterized for Ag-silica system. The material response to the laser energy deposition is studied for a range of laser fluences that, in the absence of the transparent overlayer, covers the regimes of melting and resolidification, photomechanical spallation, and phase explosion of the overheated surface region. In contrast to the irradiation in vacuum, the spatial confinement by the overlayer facilitates generation of sustained high-temperature and high-pressure conditions near the metal-overlayer interface, suppresses the generation of unloading tensile wave, decreases the maximum depth of melting, and prevents the spallation and explosive disintegration of the surface region of the metal target. At high laser fluences, when the laser excitation brings the surface region of the metal target to supercritical conditions, the confinement prevents the expansion and phase decomposition characteristic for the vacuum conditions leading to a gradual cooling of the hot compressed supercritical fluid down to the liquid phase and eventual solidification. The target modification in this case is limited to the generation of crystal defects and the detachment of the metal target from the overlayer.

  19. Overlay metallic-cermet alloy coating systems

    Science.gov (United States)

    Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

    1984-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

  20. Vanadia Supported on Mesoporous Carbon Nitride as a New Catalyst for Selective Oxidation of Benzyl Alcohol%介孔氮化碳负载氧化钒催化苯甲醇选择氧化反应

    Institute of Scientific and Technical Information of China (English)

    尚介坤; 王悦; 蒋权; 许杰; 李永昕

    2016-01-01

    Mesoporous graphitic carbon nitride (CND)was prepared and used as a catalytic support to load vanadia.The obtained V/CND materials were characterized by several characterization techniques including N2 adsorption-desorption,SAXS,TEM,XPS,Raman,FT-IR,and XPS spectroscopy.In the selective ox-idation reactions of benzyl alcohol,the V/CND showed high catalytic performances and good recyclability, especially superior selectivities (> 84%)to the values obtained over other vanadia catalysts supported on traditional materials (SBA-1 5 ,carbon nanotubes,and active carbon).As revealed by FT-IR and XPS re-sults,the active sites were attributed to the dispersed vanadia species.More importantly,the basic chemi-cal environment of the CND support was regarded to effectively restrain the deep oxidation of benzalde-hyde.%制备一系列介孔石墨相氮化碳负载氧化钒催化剂(V/CND)。通过 N2吸-脱附、小角 X 射线散射、透射电镜、X射线衍射、拉曼光谱、傅里叶红外光谱、X射线光电子能谱等表征手段对 V/CND材料的结构、形貌等理化性质进行表征。在苯甲醇选择氧化反应中,V/CND催化剂表现出较高的催化活性及良好的循环使用性。与传统载体材料(SBA-15、碳纳米管和活性炭)相比,V/CND催化剂具有更高的选择性(>84%)。测试结果表明催化剂活性中心是分散的氧化钒物种。CND材料作为一种碱性载体可以有效地抑制苯甲醛的深度氧化。

  1. Early age performance of latex-modified concrete bridge deck overlays

    Science.gov (United States)

    Sujjavanich, Suvimol

    Environmental factors and physical properties of latex modified concrete (LMC) are hypothesized to contribute to early age cracking in bridge deck overlays. Cracking permits the ingress of moisture and aggressive solutions into the substrate and may contribute to other subsequent distresses. Understanding the material properties and mechanisms involved is necessary to minimize these distresses. This research consisted of a two part study: first, the development of LMC strength and fracture properties at ages ranging from 5 hours to 28 days was studied, and secondly, the effects of the environment on LMC distresses were modelled. Environmental conditions: temperature, solar energy, and wind speed were determined from weather records. A fracture mechanics based model, the Fictitious Crack Model (FCM), incorporating finite element analyses and superposition techniques was employed with material properties from the first part of study on LMC performance. Different bilinear strain softening diagrams were used to predict fracture performance at different ages. The predictions agreed well with the test data. The impacts of temperature differentials on crack development were studied. The shrinkage effect was also indirectly incorporated through the temperature analysis. The material properties study indicated significant changes in strength, deformability and fracture properties, particularly during the early age. The developments differ slightly from conventional concrete. Test results indicated a significant improvement in reducing and bridging microcracks, especially in the prepeak-load region. Fracture toughness and deformability increased significantly with time. Fracture energy varied from 2.3 to 133.1 N/m, depending on age, and to some degree, on notch depth ratio. In the second stage, the FCM provided a reasonable prediction for crack initiation and propagation when only temperature effects are of concern. Age, surface conditions and structural restraint strongly

  2. The promotion of CO dissociation by molybdenum oxide overlayers on rhodium

    Science.gov (United States)

    Szenti, Imre; Bugyi, László; Kónya, Zoltán

    2017-03-01

    A considerable promotional effect of MoOx species observed at high pressures on the catalytic activity of rhodium initiated the present UHV model study. The MoOx overlayers formed on Rh films (0.15-20.0 ML) supported by TiO2(110) substrate were characterized by AES, TPD, work function (WF) measurements and CO adsorption. On the mixed oxide support produced by depositing 1.2 ML Mo onto TiO2(110), a new recombinative CO desorption state was observed with Tp=700 K, assigned as β-CO and related to the promotional effect of MoOx species diffused onto Rh particles of 1.0 ML coverage. The development of β-CO needs 0.5-0.7 ML threshold Rh coverage, attributable to particle size effect and geometric factors governing the CO adsorption. The β-CO state with Tp=725-742 K could also be detected on Rh films covered by MoOx moiety formed by the oxidation of Mo overlayers in O2. Remarkably, recombinative CO desorption with Tp=700 K could be observed on the Rh nanoparticles covered by MoOzCy produced from pure Mo deposits by CO adsorption, too. In harmony with the promotional effect of MoOx overlayer found at high pressures, it is established that the dissociation of CO is maximal at 0.2-0.3 ML Mo coverage, attributed to the presence of active sites at the oxide-metal interface. The low desorption peak temperature (700 K) of associative CO desorption observed in the presence of MoOx and MoOzCy overlayers indicates a low activation energy for the reactions of Oa and Ca atoms, allowing high reaction rates for these intermediates. The MoOx species exerted both promotion and inhibition effects on CO adsorption at sub-monolayer coverages, but above 1 ML it completely suppressed the reactivity of rhodium layers towards CO, suggesting that its surface concentration is a critical factor.

  3. Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

    Directory of Open Access Journals (Sweden)

    Yaw ChiaHwan

    2014-01-01

    Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

  4. A comparative study of overlay generation methods in bite mark analysis.

    Science.gov (United States)

    Khatri, Mihir; Daniel, Mariappan Jonathan; Srinivasan, Subramanian Vasudevan

    2013-01-01

    To evaluate the best method of overlay generation out of the three methods, i.e., manual, photocopying, and computer assisted method. Impressions of maxillary and mandibular arches of 25 individuals participating in the study were made and dental study models were prepared. Overlay production was done by manual, photocopying, and computer assisted methods. Finally, the overlays obtained by each method were compared. Kruskal Wallis ANOVA H test was used for the comparison of manual, photocopying, and computer assisted overlay generation methods. H value being highest in case of computer assisted overlays, thus, making it the best method of overlay generation out of the three methods. We conclude that the method of computer assisted overlay generation is the best among the three methods used in our study.

  5. A comparative study of overlay generation methods in bite mark analysis

    Directory of Open Access Journals (Sweden)

    Mihir Khatri

    2013-01-01

    Full Text Available Aim: To evaluate the best method of overlay generation out of the three methods, i.e., manual, photocopying, and computer assisted method. Materials and Methods: Impressions of maxillary and mandibular arches of 25 individuals participating in the study were made and dental study models were prepared. Overlay production was done by manual, photocopying, and computer assisted methods. Finally, the overlays obtained by each method were compared. Results: Kruskal Wallis ANOVA H test was used for the comparison of manual, photocopying, and computer assisted overlay generation methods. H value being highest in case of computer assisted overlays, thus, making it the best method of overlay generation out of the three methods. Conclusion: We conclude that the method of computer assisted overlay generation is the best among the three methods used in our study.

  6. Virtual Private Overlays: Secure Group Commounication in NAT-Constrained Environments

    CERN Document Server

    Wolinsky, David Isaac; Choi, Tae Woong; Boykin, P Oscar; Figueiredo, Renato

    2010-01-01

    Structured P2P overlays provide a framework for building distributed applications that are self-configuring, scalable, and resilient to node failures. Such systems have been successfully adopted in large-scale Internet services such as content delivery networks and file sharing; however, widespread adoption in small/medium scales has been limited due in part to security concerns and difficulty bootstrapping in NAT-constrained environments. Nonetheless, P2P systems can be designed to provide guaranteed lookup times, NAT traversal, point-to-point overlay security, and distributed data stores. In this paper we propose a novel way of creating overlays that are both secure and private and a method to bootstrap them using a public overlay. Private overlay nodes use the public overlay's distributed data store to discover each other, and the public overlay's connections to assist with NAT hole punching and as relays providing STUN and TURN NAT traversal techniques. The security framework utilizes groups, which are cr...

  7. CodedStream: live media streaming with overlay coded multicast

    Science.gov (United States)

    Guo, Jiang; Zhu, Ying; Li, Baochun

    2003-12-01

    Multicasting is a natural paradigm for streaming live multimedia to multiple end receivers. Since IP multicast is not widely deployed, many application-layer multicast protocols have been proposed. However, all of these schemes focus on the construction of multicast trees, where a relatively small number of links carry the multicast streaming load, while the capacity of most of the other links in the overlay network remain unused. In this paper, we propose CodedStream, a high-bandwidth live media distribution system based on end-system overlay multicast. In CodedStream, we construct a k-redundant multicast graph (a directed acyclic graph) as the multicast topology, on which network coding is applied to work around bottlenecks. Simulation results have shown that the combination of k-redundant multicast graph and network coding may indeed bring significant benefits with respect to improving the quality of live media at the end receivers.

  8. Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

    Institute of Scientific and Technical Information of China (English)

    LIAO Weidong; CHEN Zheng; WU Shaopeng; MO Liantong; LIU Gang

    2006-01-01

    The rutting resistance of multilayer asphalt overlay was researched by using laboratory wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evaluated by means of multilayer specimens .In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test temperature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test temperature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

  9. Modeling the dynamical interaction between epidemics on overlay networks

    CERN Document Server

    Marceau, Vincent; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J

    2011-01-01

    Epidemics seldom occur as isolated phenomena. Typically, two or more viral agents spread within the same host population and may interact dynamically with each other. We present a general model where two viral agents interact via an immunity mechanism as they propagate simultaneously on two networks connecting the same set of nodes. Exploiting a correspondence between the propagation dynamics and a dynamical process performing progressive network generation, we develop an analytic approach that accurately captures the dynamical interaction between epidemics on overlay networks. The formalism allows for overlay networks with arbitrary joint degree distribution and overlap. To illustrate the versatility of our approach, we consider a hypothetical delayed intervention scenario in which an immunizing agent is disseminated in a host population to hinder the propagation of an undesirable agent (e.g. the spread of preventive information in the context of an emerging infectious disease).

  10. On-demand Overlay Networks for Large Scientific Data Transfers

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Lavanya [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Guok, Chin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jackson, Keith [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kissel, Ezra [Univ. of Delaware, Newark, DE (United States); Swany, D. Martin [Univ. of Delaware, Newark, DE (United States); Agarwal, Deborah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2009-10-12

    Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.

  11. Performance of Superposition Coded Broadcast/Unicast Service Overlay System

    Science.gov (United States)

    Yoon, Seokhyun; Kim, Donghee

    The system level performance of a superposition coded broadcast/unicast service overlay system is considered. Cellular network for unicast service only is considered as interference limited system, where increasing the transmission power does not help improve the network throughput especially when the frequency reuse factor is close to 1. In such cases, the amount of power that does not contribute to improving the throughput can be considered as “unused.” This situation motivates us to use the unused power for broadcast services, which can be efficiently provided in OFDM based single frequency networks as in digital multimedia broadcast systems. In this paper, we investigate the performance of such a broadcast/unicast overlay system in which a single frequency broadcast service is superimposed over a unicast cellular service. Alternative service multiplexing using FDM/TDM is also considered for comparison.

  12. Effect of Fe doping on low temperature deNOx activity of high-performance vanadia-anatase nanoparticles

    DEFF Research Database (Denmark)

    Schill, Leonhard; Putluru, Siva Sankar Reddy; Jensen, Anker Degn;

    2014-01-01

    . The activities of the composite materials in the selective catalytic reduction (SCR) of NO with NH3 were measured at temperatures of up to 200 °C and in the presence of 20 vol. % H2O. Presence of Fe can increase the surface area, enhance the redox properties, increase the number of surface acid sites, increase......VFe/TiO2 catalysts have been prepared using a sol-gel based method. Fe was introduced using 3 different methods. The resulting substances were characterized with N2-physisorption, NH3-TPD, H2-TPR, XPS and XRD. Extrudates of the VFe/TiO2 powders were prepared using sepiolite (20 wt.%) as binder...

  13. Overlay bit restorer as a Phase 1 orthotic.

    Science.gov (United States)

    Neuenschwander, D

    1991-01-01

    Phase 1 (reversible) orthotic therapy is often complicated by missing teeth or the fragile nature of the materials used to construct appliances that must function under the pressures of mastication. The bite restorer combines the strength of Vitallium with the occlusal acceptability of Anodyne to produce an esthetic and functional orthotic without the ill effects of cast metallic overlays. The author uses his experience as a certified dental technician to discuss arch and tooth preparation, clasping, and proper impression technique.

  14. Mapping (USPTO) Patent Data using Overlays to Google Maps

    OpenAIRE

    Leydesdorff, Loet; Bornmann, Lutz

    2011-01-01

    A technique is developed using patent information available online (at the US Patent and Trademark Office) for the generation of Google Maps. The overlays indicate both the quantity and quality of patents at the city level. This information is relevant for research questions in technology analysis, innovation studies and evolutionary economics, as well as economic geography. The resulting maps can also be relevant for technological innovation policies and R&D management, because the US market...

  15. Pasadena, California Anaglyph with Aerial Photo Overlay

    Science.gov (United States)

    2000-01-01

    This anaglyph shows NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. Red-blue glasses are required to see the 3-D effect. The surrounding residential areas of La Canada-Flintridge (to the left) and Altadena/Pasadena (to the right) are also shown. JPL is located at the base of the San Gabriel Mountains, an actively growing mountain range, seen towards the top of the image. The large canyon coming out of the mountains (top to bottom of image) is the Arroyo Seco, which is a major drainage channel for the mountains. Sand and gravel removal operations in the lower part of the arroyo (bottom of image) are removing debris brought down by flood and mudflow events. Old landslide scars (lobe-shaped features) are seen in the arroyo, evidence that living near steep canyon slopes in tectonically active areas can be hazardous. The data can also be utilized by recreational users such as hikers enjoying the natural beauty of these rugged mountains.This anaglyph was generated using topographic data from the Shuttle Radar Topography Mission to create two differing perspectives of a single image, one perspective for each eye. The detailed aerial image was provided by U. S. Geological Survey digital orthophotography. Each point in the image is shifted slightly, depending on its elevation. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and

  16. Scalable Overlay Multicasting in Mobile Ad Hoc Networks (SOM

    Directory of Open Access Journals (Sweden)

    Pariza Kamboj

    2010-10-01

    Full Text Available Many crucial applications of MANETs like the battlefield, conference and disaster recovery defines the needs for group communications either one-to-many or many-to-many form. Multicast plays an important role in bandwidth scarce multihop mobile ad hoc networks comprise of limited battery power mobile nodes. Multicast protocols in MANETs generate many controls overhead for maintenance of multicast routingstructures due to frequent changes of network topology. Bigger multicast tables for the maintenance of network structures resultsin inefficient consumption of bandwidth of wireless links andbattery power of anemic mobile nodes, which in turn, pose thescalability problems as the network size is scaled up. However,many MANET applications demands scalability from time to time. Multicasting for MANETs, therefore, needs to reduce the state maintenance. As a remedy to these shortcomings, this paper roposes an overlay multicast protocol on application layer. In the proposed protocol titled “Scalable Overlay Multicasting in Mobile Ad Hoc Networks (SOM” the network nodes construct overlay hierarchical framework to reduce the protocols states and constrain their distribution within limited scope. Based on zone around each node, it constructs a virtual structure at application layer mapped with the physical topology at network layer, thus formed two levels of hierarchy. The concept of two level hierarchies reduces the protocol state maintenance and hence supports the vertical scalability. Protocol depends on the location information obtained using a distributed location service, which effectively reduces the overhead for route searching and updating the source based multicast tree.

  17. The outcomes of overlay myringoplasty: Endoscopic versus microscopic approach.

    Science.gov (United States)

    Plodpai, Yuvatiya; Paje, Nanatphong

    To investigate the outcomes of overlay myringoplasty by comparing the endoscopic versus the microscopic approach. This is a retrospective comparative study of 181 patients who underwent myringoplasty with overlay techniques between January 2010 and 2016 at Songklanagarind Hospital, Thailand. Group 1 underwent an endoscopic-assisted (n=90), and group 2 underwent the microscopic-assisted (n=91) overlay myringoplasty. The outcomes were graft take rates, the audiometric results, the need of canalplasty, complications and operative time. All patients were followed up for at least 6months. The graft take rates were 96.7% in the endoscopic group and 91.2% in the microscopic group, p=0.22. The operative time was 98.9±11.0min for the endoscopic group, and 176.6±14.9min for the microscope group, poverlay myringoplasty provided satisfactory surgical as well as audiometric outcomes when compared with the microscopic approach. The graft take rate and postoperative hearing were similar in both groups. The endoscopic approach seemed to be superior than the microscopic approach in term of operative time, complication, and no need for canalplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Ground truth data generation for skull-face overlay.

    Science.gov (United States)

    Ibáñez, O; Cavalli, F; Campomanes-Álvarez, B R; Campomanes-Álvarez, C; Valsecchi, A; Huete, M I

    2015-05-01

    Objective and unbiased validation studies over a significant number of cases are required to get a more solid picture on craniofacial superimposition reliability. It will not be possible to compare the performance of existing and upcoming methods for craniofacial superimposition without a common forensic database available for the research community. Skull-face overlay is a key task within craniofacial superimposition that has a direct influence on the subsequent task devoted to evaluate the skull-face relationships. In this work, we present the procedure to create for the first time such a dataset. We have also created a database with 19 skull-face overlay cases for which we are trying to overcome legal issues that allow us to make it public. The quantitative analysis made in the segmentation and registration stages, together with the visual assessment of the 19 face-to-face overlays, allows us to conclude that the results can be considered as a gold standard. With such a ground truth dataset, a new horizon is opened for the development of new automatic methods whose performance could be now objectively measured and compared against previous and future proposals. Additionally, other uses are expected to be explored to better understand the visual evaluation process of craniofacial relationships in craniofacial identification. It could be very useful also as a starting point for further studies on the prediction of the resulting facial morphology after corrective or reconstructive interventionism in maxillofacial surgery.

  19. How a gold substrate can increase the reactivity of a Pt overlayer

    DEFF Research Database (Denmark)

    Pedersen, Morten Ø.; Helveg, Stig; Ruban, Andrei

    1999-01-01

    The growth and chemical reactivity of Pt on Au(111) have been studied using scanning tunneling microscopy (STM) and temperature programmed desorption (TPD). Deposition of Pt at coverages from 0.02 ML up to 2.5 ML on Au(111) at room temperature initially leads to the formation of a surface alloy......, in which 3% of the Au atoms are replaced by Pt. Subsequent Pt evaporation leads to island growth with a mixed Pt-Au island composition. The reactivity of the Pt/Au system is studied using CO as a probe molecule. We show that a stronger bonding of CO to the first layer of Pt on Au(111) exists compared...... with the binding of CO on clean Pt. The Au substrate therefore very surprisingly increases the Pt overlayer reactivity. The results can be understood in a simple model, in which the change in the CO binding energy is directly proportional to the shift of the d-band center of the metal overlayer. According...

  20. Mechanical Properties of Stainless Steel Overlay Weld with Resistance to Hydrogen-Induced Disbonding : Study on a Stainless Steel Overlay Welding Process for Superior Resistance to Disbonding (Report 2)

    OpenAIRE

    Akiyoshi, FUJI; Etsuo, KUDO; Tomoyuki, TAKAHASHI; Kazuaki, MANO; The Japan Steel Works, Ltd., Muroran Plant

    1986-01-01

    The mechanical properties of the disbanding resistant stainless steel overlay weld were studied and compared with those of the conventional overlay weld. It was found that the mechanical properties of the disbanding resistant overlay weld were almost equal to those of the conventional overlay weld, whereas the residual sites in through-thickness direction at the bond between the first layer weld metal and the base metal was smaller than t/.al of the conventional overlay weld. This low residua...

  1. Improved antifouling properties and selective biofunctionalization of stainless steel by employing heterobifunctional silane-polyethylene glycol overlayers and avidin-biotin technology

    Science.gov (United States)

    Hynninen, Ville; Vuori, Leena; Hannula, Markku; Tapio, Kosti; Lahtonen, Kimmo; Isoniemi, Tommi; Lehtonen, Elina; Hirsimäki, Mika; Toppari, J. Jussi; Valden, Mika; Hytönen, Vesa P.

    2016-07-01

    A straightforward solution-based method to modify the biofunctionality of stainless steel (SS) using heterobifunctional silane-polyethylene glycol (silane-PEG) overlayers is reported. Reduced nonspecific biofouling of both proteins and bacteria onto SS and further selective biofunctionalization of the modified surface were achieved. According to photoelectron spectroscopy analyses, the silane-PEGs formed less than 10 Å thick overlayers with close to 90% surface coverage and reproducible chemical compositions. Consequently, the surfaces also became more hydrophilic, and the observed non-specific biofouling of proteins was reduced by approximately 70%. In addition, the attachment of E. coli was reduced by more than 65%. Moreover, the potential of the overlayer to be further modified was demonstrated by successfully coupling biotinylated alkaline phosphatase (bAP) to a silane-PEG-biotin overlayer via avidin-biotin bridges. The activity of the immobilized enzyme was shown to be well preserved without compromising the achieved antifouling properties. Overall, the simple solution-based approach enables the tailoring of SS to enhance its activity for biomedical and biotechnological applications.

  2. Improved antifouling properties and selective biofunctionalization of stainless steel by employing heterobifunctional silane-polyethylene glycol overlayers and avidin-biotin technology

    Science.gov (United States)

    Hynninen, Ville; Vuori, Leena; Hannula, Markku; Tapio, Kosti; Lahtonen, Kimmo; Isoniemi, Tommi; Lehtonen, Elina; Hirsimäki, Mika; Toppari, J. Jussi; Valden, Mika; Hytönen, Vesa P.

    2016-01-01

    A straightforward solution-based method to modify the biofunctionality of stainless steel (SS) using heterobifunctional silane-polyethylene glycol (silane-PEG) overlayers is reported. Reduced nonspecific biofouling of both proteins and bacteria onto SS and further selective biofunctionalization of the modified surface were achieved. According to photoelectron spectroscopy analyses, the silane-PEGs formed less than 10 Å thick overlayers with close to 90% surface coverage and reproducible chemical compositions. Consequently, the surfaces also became more hydrophilic, and the observed non-specific biofouling of proteins was reduced by approximately 70%. In addition, the attachment of E. coli was reduced by more than 65%. Moreover, the potential of the overlayer to be further modified was demonstrated by successfully coupling biotinylated alkaline phosphatase (bAP) to a silane-PEG-biotin overlayer via avidin-biotin bridges. The activity of the immobilized enzyme was shown to be well preserved without compromising the achieved antifouling properties. Overall, the simple solution-based approach enables the tailoring of SS to enhance its activity for biomedical and biotechnological applications. PMID:27381834

  3. Malaspina Glacier, Alaska, Anaglyph with Landsat Overlay

    Science.gov (United States)

    2003-01-01

    are caught up in the deposits and then melt, locally collapsing the deposit. The combination of Landsat imagery and SRTM elevation data used in this stereoscopic display is very effective in visualizing these and other features of this terrain. The stereoscopic effect of this anaglyph was created by registering a Landsat image to the SRTM elevation model and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 55 x 55 kilometers (34 x 34 miles) Location: 60 deg N latitude, 140 deg W longitude Orientation: North at top Image Data: Landsat Thematic Mapper visible and infrared band mix Original Data

  4. Malaspina Glacier, Alaska, Perspective with Landsat Overlay

    Science.gov (United States)

    2003-01-01

    in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 55 kilometers wide x 55 kilometers distance (34 x 34 miles) Location: 60 deg N latitude, 140 deg W longitude Orientation: View North, 2X vertical exaggeration Image Data: Landsat Thematic Mapper false-color image Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Landsat 30 meters (98 feet) Date Acquired: February 2000 (SRTM), 31 August 2000 (Landsat)

  5. The migration law of overlay rock and coal in deeply inclined coal seam with fully mechanized top coal caving.

    Science.gov (United States)

    Liu, Jian; Chen, Shan-Le; Wang, Hua-Jun; Li, Yu-Cheng; Geng, Xiaowei

    2015-07-01

    In a mine area, some environment geotechnics problems always occure, induced by mined-out region such as the subsidence and cracks at ground level, deformation and destruction of buildings, landslides destruction of water resources and the ecological environment. In order to research the migration of surrounding rock and coal in steeply inclined super high seams which used fully mechanized top coal caving, a working face of a certain mine was made as an example, analyzed the migration law of the overlay rock and coal under different caving ratio of fully mechanized top coal caving with numerical simulation analysis. The results suggest that the laws of overlay rock deformation caused by deeply inclined coal seam were different from horizontal coal seam. On the inclined direction, with an increase of dip angle and caving ratio, the vertical displacement of overlay rock and coal became greater, the asymmetric phenomenon of vertical displacement became obvious. On the trend direction, active region and transition region in goaf became smaller along with the increase of mining and caving ratio. On the contrary, the stable region area became greater. Therefore, there was an essential difference between the mechanism of surface movement deformation with deeply inclined coal seam and that with horizontal coal seam.

  6. Intra-lot wafer by wafer overlay control using integrated and standalone metrology combined sampling

    Science.gov (United States)

    Choi, Young Sin; Nam, Young Sun; Lee, Dong Han; Lee, Jae Il; Kang, Young Seog; Jang, Se Yeon; Kong, Jeong Heung

    2016-03-01

    As overlay margin is getting tighter, traditional overlay correction method is not enough to secure more overlay margin without extended correction potential on lithography tool. Timely, the lithography tool has a capability of wafer to wafer correction. From these well-timed industry's preparations, the uncorrected overlay error from current sampling in a lot could be corrected for yield enhancement. In this paper, overlay budget break was performed prior to experiments with the purpose of estimating amount of overlay improvement. And wafer to wafer correction was simulated to the specified layer of a 2x node DRAM device. As a result, not only maximum 94.4% of residual variation improvement is estimated, but also recognized that more samplings to cover all wafer's behavior is inevitable. Integrated metrology with optimized sampling scheme was also introduced as a supportive method for more samplings.

  7. Evaluation of parameters affecting reflection cracking in geogrid-reinforced overlay

    Institute of Scientific and Technical Information of China (English)

    Shahab Fallah; Ali Khodaii

    2015-01-01

    The influence of the most important parameters on the service life of reinforced asphalt overlay with geogrid materials in bending mode was examined by employing the Taguchi method and analysis of variance techniques. The objectives of this experiment was to investigate the effects of grid stiffness, tensile strength, coating type, amount of tack coat, overlay thickness, crack width and stiffnesses of asphalt overlay and existing asphalt concrete on propagation of the reflection cracking. Results indicate that the stiffnesses of cracked layer and overlay are the main significant factors that can directly improve the service life of an overlay against the reflection cracking. Generally, glass grid is more effective in reinforced overlay than polyester grid. Effect of crack width of the existing layer is significant when its magnitude increases from 6 to 9 mm.

  8. MR-guided vertebroplasty with augmented reality image overlay navigation.

    Science.gov (United States)

    Fritz, Jan; U-Thainual, Paweena; Ungi, Tamas; Flammang, Aaron J; Kathuria, Sudhir; Fichtinger, Gabor; Iordachita, Iulian I; Carrino, John A

    2014-12-01

    To evaluate the feasibility of magnetic resonance imaging (MRI)-guided vertebroplasty at 1.5 Tesla using augmented reality image overlay navigation. Twenty-five unilateral vertebroplasties [5 of 25 (20%) thoracic, 20 of 25 (80%) lumbar] were prospectively planned in 5 human cadavers. A clinical 1.5-Teslan MRI system was used. An augmented reality image overlay navigation system and 3D Slicer visualization software were used for MRI display, planning, and needle navigation. Intermittent MRI was used to monitor placement of the MRI-compatible vertebroplasty needle. Cement injections (3 ml of polymethylmethacrylate) were performed outside the bore. The cement deposits were assessed on intermediate-weighted MR images. Outcome variables included type of vertebral body access, number of required intermittent MRI control steps, location of final needle tip position, cement deposit location, and vertebroplasty time. All planned procedures (25 of 25, 100%) were performed. Sixteen of 25 (64%) transpedicular and 9 of 25 (36%) parapedicular access routes were used. Six (range 3-9) MRI control steps were required for needle placement. No inadvertent punctures were visualized. Final needle tip position and cement location were adequate in all cases (25 of 25, 100%) with a target error of the final needle tip position of 6.1 ± 1.9 mm (range 0.3-8.7 mm) and a distance between the planned needle tip position and the center of the cement deposit of 4.3 mm (range 0.8-6.8 mm). Time requirement for one level was 16 (range 11-21) min. MRI-guided vertebroplasty using image overlay navigation is feasible allowing for accurate vertebral body access and cement deposition in cadaveric thoracic and lumbar vertebral bodies.

  9. A comparative study of overlay generation methods in bite mark analysis

    OpenAIRE

    Mihir Khatri; Mariappan Jonathan Daniel; Subramanian Vasudevan Srinivasan

    2013-01-01

    Aim: To evaluate the best method of overlay generation out of the three methods, i.e., manual, photocopying, and computer assisted method. Materials and Methods: Impressions of maxillary and mandibular arches of 25 individuals participating in the study were made and dental study models were prepared. Overlay production was done by manual, photocopying, and computer assisted methods. Finally, the overlays obtained by each method were compared. Results: Kruskal Wallis ANOVA H test was used for...

  10. OMAN - A Management Architecture for P2P Service Overlay Networks

    OpenAIRE

    Fiorese, Adriano; Simões, Paulo; Boavida, Fernando

    2010-01-01

    International audience; In a world where networking services are increasingly being provided by service overlay networks, management of these services at overlay level is becoming crucially important. This paper presents an architecture for services management in P2P Service Overlay Networks (SON). The architecture, named OMAN, takes into account the formation of the P2P SON comprising several different service providers belonging to several different network domains. It uses P2P mechanisms t...

  11. Using overlay network architectures for scalable video distribution

    Science.gov (United States)

    Patrikakis, Charalampos Z.; Despotopoulos, Yannis; Fafali, Paraskevi; Cha, Jihun; Kim, Kyuheon

    2004-11-01

    Within the last years, the enormous growth of Internet based communication as well as the rapid increase of available processing power has lead to the widespread use of multimedia streaming as a means to convey information. This work aims at providing an open architecture designed to support scalable streaming to a large number of clients using application layer multicast. The architecture is based on media relay nodes that can be deployed transparently to any existing media distribution scheme, which can support media streamed using the RTP and RTSP protocols. The architecture is based on overlay networks at application level, featuring rate adaptation mechanisms for responding to network congestion.

  12. Autologous adventitial overlay method reinforces anastomoses in aortic surgery.

    Science.gov (United States)

    Minato, Naoki; Okada, Takayuki; Sumida, Tomohiko; Watanabe, Kenichi; Maruyama, Takahiro; Kusunose, Takashi

    2014-05-01

    In this study, we present an inexpensive and effective method for providing a secure and hemostatic anastomosis using autologous adventitia obtained from a dissected or aneurysmal wall. The resected aortic wall is separated between the adventitia and media, and a soft, 2 × 10-cm adventitial strip is overlaid to cover the anastomotic margin. A graft is sutured to the aortic stump. This autologous adventitial overlay method can inexpensively and strongly reinforce the anastomosis during aortic surgery for dissection or aneurysm and will contribute to anastomotic hemostasis and long-term stability.

  13. THE FUZZY OVERLAY STUDENT MODEL IN AN INTELLIGENT TUTORING SYSTEM

    Directory of Open Access Journals (Sweden)

    D. I. Popov

    2015-01-01

    Full Text Available The article is devoted to the development of the student model for use in an intelligent tutoring system (ITS designed for the evaluation of students’ competencies in different Higher Education Facilities. There are classification and examples of the various student models, the most suitable for the evaluation of competencies is selected and finalized. The dynamic overlay fuzzy student model builded on the domain model based on the concept of didactic units is described in this work. The formulas, chart and diagrams are provided.

  14. Bandwidth auction for SVC streaming in dynamic multi-overlay

    Science.gov (United States)

    Xiong, Yanting; Zou, Junni; Xiong, Hongkai

    2010-07-01

    In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.

  15. Ductile film delamination from compliant substrates using hard overlayers

    Science.gov (United States)

    Cordill, M.J.; Marx, V.M.; Kirchlechner, C.

    2014-01-01

    Flexible electronic devices call for copper and gold metal films to adhere well to polymer substrates. Measuring the interfacial adhesion of these material systems is often challenging, requiring the formulation of different techniques and models. Presented here is a strategy to induce well defined areas of delamination to measure the adhesion of copper films on polyimide substrates. The technique utilizes a stressed overlayer and tensile straining to cause buckle formation. The described method allows one to examine the effects of thin adhesion layers used to improve the adhesion of flexible systems. PMID:25641995

  16. Opportunistic transmitter selection for selfless overlay cognitive radios

    KAUST Repository

    Shaqfeh, Mohammad

    2013-11-01

    We propose an opportunistic strategy to grant channel access to the primary and secondary transmitters in causal selfless overlay cognitive radios over block-fading channels. The secondary transmitter helps the primary transmitter by relaying the primary messages opportunistically, aided by a buffer to store the primary messages temporarily. The optimal channel-aware transmitter- selection strategy is the solution of the maximization of the average secondary rate under the average primary rate requirement and the buffer stability constraints. Numerical results demonstrate the gains of the proposed opportunistic selection strategy. © 2013 IEEE.

  17. Employing Multicast in P2P Overlay Networks

    Science.gov (United States)

    Kolberg, Mario

    The work on multicast has evolved from bottom IP layer multicast to Application Layer Multicast. While there are issues with the dep-loyment of IP layer multicast, it outperforms Application Layer Multicast. However, the latter has the advantage of an easier dep-loyment. Furthermore, as will be illustrated later in this Chapter, IP layer multicast has the potential to make parallel overlay operations more efficient. Application Layer Multicast is primarily used to send application specific messages/data to a number of nodes.

  18. Infrared differential interference contrast microscopy for 3D interconnect overlay metrology.

    Science.gov (United States)

    Ku, Yi-sha; Shyu, Deh-Ming; Lin, Yeou-Sung; Cho, Chia-Hung

    2013-08-12

    One of the main challenges for 3D interconnect metrology of bonded wafers is measuring through opaque silicon wafers using conventional optical microscopy. We demonstrate here the use infrared microscopy, enhanced by implementing the differential interference contrast (DIC) technique, to measure the wafer bonding overlay. A pair of two dimensional symmetric overlay marks were processed at both the front and back sides of thinned wafers to evaluate the bonding overlay. A self-developed analysis algorithm and theoretical fitting model was used to map the overlay error between the bonded wafers and the interconnect structures. The measurement accuracy was found to be better than 1.0 micron.

  19. Algorithms for Constructing Overlay Networks For Live Streaming

    CERN Document Server

    Andreev, Konstantin; Meyerson, Adam; Saks, Jevan; Sitaraman, Ramesh K

    2011-01-01

    We present a polynomial time approximation algorithm for constructing an overlay multicast network for streaming live media events over the Internet. The class of overlay networks constructed by our algorithm include networks used by Akamai Technologies to deliver live media events to a global audience with high fidelity. We construct networks consisting of three stages of nodes. The nodes in the first stage are the entry points that act as sources for the live streams. Each source forwards each of its streams to one or more nodes in the second stage that are called reflectors. A reflector can split an incoming stream into multiple identical outgoing streams, which are then sent on to nodes in the third and final stage that act as sinks and are located in edge networks near end-users. As the packets in a stream travel from one stage to the next, some of them may be lost. A sink combines the packets from multiple instances of the same stream (by reordering packets and discarding duplicates) to form a single in...

  20. Hastelloy C-276Weld Overlay bySMAW Process

    Directory of Open Access Journals (Sweden)

    Er. Rahul Sharma

    2017-05-01

    Full Text Available In the modern world of industrialization the wear is eating metal assets worth millions of dollars per year. The wear is in the form of corrosion, erosion, abrasion etc. which occur in the process industries like oil & gas, refineries, cement plants, steel plants, shipping and offshore working structures. The equipments like pressure vessels, heat exchangers, hydro processing reactors which very often work at elevated temperatures face corrosion in the internal diameter.Hastelloy C-276weld overlay on ferrous material is developed for outstanding resistance to wide variety of chemical process environments such as ferric and cupric chlorides, hot contaminated mineral acids, solvents, chlorine and chlorine contained media, both inorganic and organic, dry chlorine, formic and acetic acids, acetic anhydride, sea water and brine solutions.Selection of SMAW is for development of hastalloy C-276 material with SMAW process to use as a weld overlay process at non accessible area & where position is constraint which is not feasible by other processes like ESSC, FCAW, and SAW etc.

  1. Replication in Overlay Networks: A Multi-objective Optimization Approach

    Science.gov (United States)

    Al-Haj Hassan, Osama; Ramaswamy, Lakshmish; Miller, John; Rasheed, Khaled; Canfield, E. Rodney

    Recently, overlay network-based collaborative applications such as instant messaging, content sharing, and Internet telephony are becoming increasingly popular. Many of these applications rely upon data-replication to achieve better performance, scalability, and reliability. However, replication entails various costs such as storage for holding replicas and communication overheads for ensuring replica consistency. While simple rule-of-thumb strategies are popular for managing the cost-benefit tradeoffs of replication, they cannot ensure optimal resource utilization. This paper explores a multi-objective optimization approach for replica management, which is unique in the sense that we view the various factors influencing replication decisions such as access latency, storage costs, and data availability as objectives, and not as constraints. This enables us to search for solutions that yield close to optimal values for these parameters. We propose two novel algorithms, namely multi-objective Evolutionary (MOE) algorithm and multi-objective Randomized Greedy (MORG) algorithm for deciding the number of replicas as well as their placement within the overlay. While MOE yields higher quality solutions, MORG is better in terms of computational efficiency. The paper reports a series of experiments that demonstrate the effectiveness of the proposed algorithms.

  2. Lightweight storage and overlay networks for fault tolerance.

    Energy Technology Data Exchange (ETDEWEB)

    Oldfield, Ron A.

    2010-01-01

    The next generation of capability-class, massively parallel processing (MPP) systems is expected to have hundreds of thousands to millions of processors, In such environments, it is critical to have fault-tolerance mechanisms, including checkpoint/restart, that scale with the size of applications and the percentage of the system on which the applications execute. For application-driven, periodic checkpoint operations, the state-of-the-art does not provide a scalable solution. For example, on today's massive-scale systems that execute applications which consume most of the memory of the employed compute nodes, checkpoint operations generate I/O that consumes nearly 80% of the total I/O usage. Motivated by this observation, this project aims to improve I/O performance for application-directed checkpoints through the use of lightweight storage architectures and overlay networks. Lightweight storage provide direct access to underlying storage devices. Overlay networks provide caching and processing capabilities in the compute-node fabric. The combination has potential to signifcantly reduce I/O overhead for large-scale applications. This report describes our combined efforts to model and understand overheads for application-directed checkpoints, as well as implementation and performance analysis of a checkpoint service that uses available compute nodes as a network cache for checkpoint operations.

  3. The role of carbon overlayers on Pt-based catalysts for H2-cleanup by CO-PROX

    Science.gov (United States)

    Romero-Sarria, F.; Garcia-Dali, S.; Palma, S.; Jimenez-Barrera, E. M.; Oliviero, L.; Bazin, P.; Odriozola, J. A.

    2016-06-01

    In this work, we analyze the effect of the activation method on the catalytic activity of Pt-based catalysts supported on alumina in the PROX reaction. For this, model Pt/Al2O3 catalysts with variable amounts of acetic acid were prepared and their thermal evolution studied by FTIR spectroscopy. From the analysis of the nature of the platinum surface upon acetic acid decomposition and the gas phase evolved products, we have demonstrated the formation of partially hydrogenated carbon overlayers that tailor the activity of Pt-based catalysts in the PROX reaction.

  4. Laser-induced ferroelectric domain engineering in LiNbO3 crystals using an amorphous silicon overlayer

    Science.gov (United States)

    Zisis, G.; Martinez-Jimenez, G.; Franz, Y.; Healy, N.; Masaud, T. M.; Chong, H. M. H.; Soergel, E.; Peacock, A. C.; Mailis, S.

    2017-08-01

    We report laser-induced poling inhibition and direct poling in lithium niobate crystals (LiNbO3), covered with an amorphous silicon (a-Si) light-absorbing layer, using a visible (488 nm) continuous wave laser source. Our results show that the use of the a-Si overlayer produces deeper poling inhibited domains with minimum surface damage, as compared to previously reported UV laser writing experiments on uncoated crystals, thus increasing the applicability of this method in the production of ferroelectric domain engineered structures for nonlinear optical applications. The characteristics of the poling inhibited domains were investigated using differential etching and piezoresponse force microscopy.

  5. 用于网格计算的Overlay Network 设计算法的研究%Research on Overlay Network Topology Design Algorithm Used in Grid

    Institute of Scientific and Technical Information of China (English)

    曹怀虎; 余镇危; 潘耘

    2006-01-01

    针对如何提供丰富的通信交互提出了一种基于Overlay Network 的网格架构,设计Overlay Network,给出了一种动态环境中分布式拉格朗日启发式算法DLagrOTDP,计算的结果显示该算法具有更快的适应性.

  6. Influence of overlay restorative materials and load cusps on the fatigue resistance of endodontically treated molars.

    Science.gov (United States)

    Magne, Pascal; Knezevic, Alena

    2009-10-01

    To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL and MKIIGL-Z, oven-glazed), and 10 restorations were duplicated with a composite resin (Miris 2, Coltane/Whaledent; group M2). The fitting surfaces of the restorations were hydrofluoric acid etched (porcelain only) and silanated. Preparations were airborne-particle abraded and etched. All restorations were luted with preheated Filtek Z100 (3M ESPE) and subjected to cyclic isometric chewing (5 Hz) starting at 200 N (5,000 cycles), followed by stages of 400, 600, 800, 1,000, 1,200, and 1,400 N at a maximum of 30,000 cycles each. A stainless steel load sphere was used for groups MKIIGL and M2, while a composite resin load sphere was used in group MKIIGL-Z. All samples were loaded until fracture or to a maximum of 185,000 cycles. Groups were compared using the Kaplan-Meier survival curves (P = .05). None of the molars restored with porcelain withstood all 185,000 loading cycles (survival = 0%). The mean fracture load for MKIIGL was 1,060 N and for MKIIGL-Z, 1,280 N. In group M2, the survival rate was 50%. The rate of fracture below the CEJ was 40%, 30%, and 20% for MKIIGL, MKIIGL-Z, and M2, respectively. Miris 2 overlays showed higher fatigue resistance than MKII porcelain (P = .01) when loaded with a stainless steel antagonist.

  7. Thickness of CAD-CAM composite resin overlays influences fatigue resistance of endodontically treated premolars.

    Science.gov (United States)

    Magne, Pascal; Knezevic, Alena

    2009-10-01

    Evaluate the influence of composite resin CAD-CAM restoration thickness on the in vitro fatigue resistance and failure mode of overlay-type restoration in endodontically treated premolars. Thirty extracted premolars received root canal treatment followed by a standardized tooth preparation (1.5-, 2.5- or 3.5-mm cusp reduction, proximal gingival margins located 1.5mm below the CEJ, glass-ionomer base and immediately sealed dentin with Optibond FL). Restorations were milled using Cerec3 and FiltekMZ100 composite blocks. The intaglio surfaces of the overlays were sandblasted and silanated. Tooth preparations were sandblasted and etched before insertion of the restoration. All restorations were luted with Optibond FL and preheated FiltekZ100. A closed-loop servohydraulic unit was used for simulating cyclic isometric chewing at 5 Hz, starting with a load of 200 N (5000 cycles), followed by stages of 400, 600, 800, 1000, 1200 and 1400 N at a maximum of 30,000 cycles each. All samples were loaded until fracture or to a maximum of 185,000 cycles. Groups were compared using the Kaplan-Meier survival curves. None of the restored premolars with the 1.5-mm cusp overlap restoration withstood all 185,000 loading cycles. With 2.5- and 3.5-mm cusp overlap, the survival rate was 30% and 40%, respectively. The rate of fracture below the CEJ was 60%, 60% and 30% for 1.5, 2.5 and 3.5 mm of cusp overlap, respectively. Survival of restored premolars with 2.5- and 3.5-mm cusp coverage was not significantly different (p=.23). Thick FiltekMZ100 composite resin onlays showed higher fatigue resistance than thin ones and may be associated with fractures that are less subgingival.

  8. Questioning the Benefits That Coloured Overlays Can Have for Reading in Students with and without Dyslexia

    Science.gov (United States)

    Henderson, Lisa M.; Tsogka, Natassa; Snowling, Margaret J.

    2013-01-01

    Visual stress (the experience of visual distortions and discomfort during prolonged reading) is frequently identified and alleviated with coloured overlays or lenses. Previous studies have associated visual stress with dyslexia and as a consequence, coloured overlays are widely distributed to children and adults with reading difficulty. However,…

  9. Live 3D image overlay for arterial duct closure with Amplatzer Duct Occluder II additional size.

    Science.gov (United States)

    Goreczny, Sebstian; Morgan, Gareth J; Dryzek, Pawel

    2016-03-01

    Despite several reports describing echocardiography for the guidance of ductal closure, two-dimensional angiography remains the mainstay imaging tool; three-dimensional rotational angiography has the potential to overcome some of the drawbacks of standard angiography, and reconstructed image overlay provides reliable guidance for device placement. We describe arterial duct closure solely from venous approach guided by live three-dimensional image overlay.

  10. Predicting the accuracy of ligand overlay methods with Random Forest models.

    Science.gov (United States)

    Nandigam, Ravi K; Evans, David A; Erickson, Jon A; Kim, Sangtae; Sutherland, Jeffrey J

    2008-12-01

    The accuracy of binding mode prediction using standard molecular overlay methods (ROCS, FlexS, Phase, and FieldCompare) is studied. Previous work has shown that simple decision tree modeling can be used to improve accuracy by selection of the best overlay template. This concept is extended to the use of Random Forest (RF) modeling for template and algorithm selection. An extensive data set of 815 ligand-bound X-ray structures representing 5 gene families was used for generating ca. 70,000 overlays using four programs. RF models, trained using standard measures of ligand and protein similarity and Lipinski-related descriptors, are used for automatically selecting the reference ligand and overlay method maximizing the probability of reproducing the overlay deduced from X-ray structures (i.e., using rmsd overlay accuracy, and their use in template and method selection produces correct overlays in 57% of cases for 349 overlay ligands not used for training RF models. The inclusion in the models of protein sequence similarity enables the use of templates bound to related protein structures, yielding useful results even for proteins having no available X-ray structures.

  11. Viral concentration determination through plaque assays: using traditional and novel overlay systems.

    Science.gov (United States)

    Baer, Alan; Kehn-Hall, Kylene

    2014-11-04

    Plaque assays remain one of the most accurate methods for the direct quantification of infectious virons and antiviral substances through the counting of discrete plaques (infectious units and cellular dead zones) in cell culture. Here we demonstrate how to perform a basic plaque assay, and how differing overlays and techniques can affect plaque formation and production. Typically solid or semisolid overlay substrates, such as agarose or carboxymethyl cellulose, have been used to restrict viral spread, preventing indiscriminate infection through the liquid growth medium. Immobilized overlays restrict cellular infection to the immediately surrounding monolayer, allowing the formation of discrete countable foci and subsequent plaque formation. To overcome the difficulties inherent in using traditional overlays, a novel liquid overlay utilizing microcrystalline cellulose and carboxymethyl cellulose sodium has been increasingly used as a replacement in the standard plaque assay. Liquid overlay plaque assays can be readily performed in either standard 6 or 12 well plate formats as per traditional techniques and require no special equipment. Due to its liquid state and subsequent ease of application and removal, microculture plate formats may alternatively be utilized as a rapid, accurate and high throughput alternative to larger scale viral titrations. Use of a non heated viscous liquid polymer offers the opportunity to streamline work, conserves reagents, incubator space, and increases operational safety when used in traditional or high containment labs as no reagent heating or glassware are required. Liquid overlays may also prove more sensitive than traditional overlays for certain heat labile viruses.

  12. A new approach for overlay text detection and extraction from complex video scene.

    Science.gov (United States)

    Kim, Wonjun; Kim, Changick

    2009-02-01

    Overlay text brings important semantic clues in video content analysis such as video information retrieval and summarization, since the content of the scene or the editor's intention can be well represented by using inserted text. Most of the previous approaches to extracting overlay text from videos are based on low-level features, such as edge, color, and texture information. However, existing methods experience difficulties in handling texts with various contrasts or inserted in a complex background. In this paper, we propose a novel framework to detect and extract the overlay text from the video scene. Based on our observation that there exist transient colors between inserted text and its adjacent background, a transition map is first generated. Then candidate regions are extracted by a reshaping method and the overlay text regions are determined based on the occurrence of overlay text in each candidate. The detected overlay text regions are localized accurately using the projection of overlay text pixels in the transition map and the text extraction is finally conducted. The proposed method is robust to different character size, position, contrast, and color. It is also language independent. Overlay text region update between frames is also employed to reduce the processing time. Experiments are performed on diverse videos to confirm the efficiency of the proposed method.

  13. A cortical locus for anisotropic overlay suppression of stimuli presented at fixation.

    Science.gov (United States)

    Hansen, Bruce C; Richard, Bruno; Andres, Kristin; Johnson, Aaron P; Thompson, Benjamin; Essock, Edward A

    2015-01-01

    Human contrast sensitivity for narrowband Gabor targets is suppressed when superimposed on narrowband masks of the same spatial frequency and orientation (referred to as overlay suppression), with suppression being broadly tuned to orientation and spatial frequency. Numerous behavioral and neurophysiological experiments have suggested that overlay suppression originates from the initial lateral geniculate nucleus (LGN) inputs to V1, which is consistent with the broad tuning typically reported for overlay suppression. However, recent reports have shown narrowly tuned anisotropic overlay suppression when narrowband targets are masked by broadband noise. Consequently, researchers have argued for an additional form of overlay suppression that involves cortical contrast gain control processes. The current study sought to further explore this notion behaviorally using narrowband and broadband masks, along with a computational neural simulation of the hypothesized underlying gain control processes in cortex. Additionally, we employed transcranial direct current stimulation (tDCS) in order to test whether cortical processes are involved in driving narrowly tuned anisotropic suppression. The behavioral results yielded anisotropic overlay suppression for both broadband and narrowband masks and could be replicated with our computational neural simulation of anisotropic gain control. Further, the anisotropic form of overlay suppression could be directly modulated by tDCS, which would not be expected if the suppression was primarily subcortical in origin. Altogether, the results of the current study provide further evidence in support of an additional overlay suppression process that originates in cortex and show that this form of suppression is also observable with narrowband masks.

  14. FLUORESCENCE OVERLAY ANTIGEN MAPPING OF THE EPIDERMAL BASEMENT-MEMBRANE ZONE .1. GEOMETRIC ERRORS

    NARCIS (Netherlands)

    BRUINS, S; DEJONG, MCJM; HEERES, K; WILKINSON, MHF; JONKMAN, MF; VANDERMEER, JB

    To identify in tissue sections the relative positions of antigen distributions close to the resolving power of the microscope, we have developed the fluorescence overlay antigen mapping (FOAM) procedure. As this technique makes high demands on the geometric fidelity of the overlay image, it is

  15. Trends in Development of Weld Overlaying During The 21ST Century

    Directory of Open Access Journals (Sweden)

    Nikolov Mitko

    2014-08-01

    Full Text Available The present article discusses the trends in the development of welding and weld overlaying on the threshold of the new millennium and during it. It presents the trends in the production of welding materials for welding and weld overlaying in industrially developed and developing countries. The structure of welding methods is also shown, giving priority to its development until 2020.

  16. Questioning the Benefits That Coloured Overlays Can Have for Reading in Students with and without Dyslexia

    Science.gov (United States)

    Henderson, Lisa M.; Tsogka, Natassa; Snowling, Margaret J.

    2013-01-01

    Visual stress (the experience of visual distortions and discomfort during prolonged reading) is frequently identified and alleviated with coloured overlays or lenses. Previous studies have associated visual stress with dyslexia and as a consequence, coloured overlays are widely distributed to children and adults with reading difficulty. However,…

  17. FLUORESCENCE OVERLAY ANTIGEN MAPPING OF THE EPIDERMAL BASEMENT-MEMBRANE ZONE .1. GEOMETRIC ERRORS

    NARCIS (Netherlands)

    BRUINS, S; DEJONG, MCJM; HEERES, K; WILKINSON, MHF; JONKMAN, MF; VANDERMEER, JB

    1994-01-01

    To identify in tissue sections the relative positions of antigen distributions close to the resolving power of the microscope, we have developed the fluorescence overlay antigen mapping (FOAM) procedure. As this technique makes high demands on the geometric fidelity of the overlay image, it is essen

  18. FLUORESCENCE OVERLAY ANTIGEN MAPPING OF THE EPIDERMAL BASEMENT-MEMBRANE ZONE .1. GEOMETRIC ERRORS

    NARCIS (Netherlands)

    BRUINS, S; DEJONG, MCJM; HEERES, K; WILKINSON, MHF; JONKMAN, MF; VANDERMEER, JB

    1994-01-01

    To identify in tissue sections the relative positions of antigen distributions close to the resolving power of the microscope, we have developed the fluorescence overlay antigen mapping (FOAM) procedure. As this technique makes high demands on the geometric fidelity of the overlay image, it is essen

  19. Strain Response of Hot-Mix Asphalt Overlays for Bottom-Up Reflective Cracking

    CERN Document Server

    Ghauch, Ziad G

    2011-01-01

    This paper examines the strain response of typical HMA overlays above jointed PCC slabs prone to bottom-up reflective cracking. The occurrence of reflective cracking under the combined effect of traffic and environmental loading significantly reduces the design life of the HMA overlays and can lead to its premature failure. In this context, viscoelastic material properties combined with cyclic vehicle loadings and pavement temperature distribution were implemented in a series of FE models in order to study the evolution of horizontal tensile and shear strains at the bottom of the HMA overlay. The effect of several design parameters, such as subbase and subgrade moduli, vehicle speed, overlay thickness, and temperature condition, on the horizontal and shear strain response was investigated. Results obtained show that the rate of horizontal and shear strain increase at the bottom of the HMA overlay drop with higher vehicle speed, higher subgrade modulus, and higher subbase modulus. Moreover, the rate of horizon...

  20. Axial compression behavior of concrete masonry wallettes strengthened with cement mortar overlays

    Directory of Open Access Journals (Sweden)

    F. L. De Oliveira

    Full Text Available This paper presents the results of a series of axial compression tests on concrete block wallettes coated with cement mortar overlays. Different types of mortars and combinations with steel welded meshes and fibers were tested. The experimental results were discussed based on different theoretical approaches: analytical and Finite Element Method models. The main conclusions are: a the application of mortar overlays increases the wall strength, but not in a uniform manner; b the strengthening efficiency of wallettes loaded in axial compression is not proportional to the overlay mortar strength because it can be affected by the failure mechanisms of the wall; c steel mesh reinforced overlays in combination with high strength mortar show better efficiency, because the steel mesh mitigates the damage effects in the block wall and in the overlays themselves; d simplified theoretical methods of analysis as described in this paper can give satisfactory predictions of masonry wall behavior up to a certain level.

  1. Fundamentals of overlay measurement and inspection using scanning electron-microscope

    Science.gov (United States)

    Kato, T.; Okagawa, Y.; Inoue, O.; Arai, K.; Yamaguchi, S.

    2013-04-01

    Scanning electron-microscope (SEM) has been successfully applied to CD measurement as promising tools for qualifying and controlling quality of semiconductor devices in in-line manufacturing process since 1985. Furthermore SEM is proposed to be applied to in-die overlay monitor in the local area which is too small to be measured by optical overlay measurement tools any more, when the overlay control limit is going to be stringent and have un-ignorable dependence on device pattern layout, in-die location, and singular locations in wafer edge, etc. In this paper, we proposed new overlay measurement and inspection system to make an effective use of in-line SEM image, in consideration of trade-off between measurement uncertainty and measurement pattern density in each SEM conditions. In parallel, we make it clear that the best hybrid overlay metrology is in considering each tool's technology portfolio.

  2. Effect of PCC Joint Skew on Reflective Cracking in HMA Overlays

    CERN Document Server

    Ghauch, By Ziad G

    2011-01-01

    Reflective cracking is a relatively premature distress that occurs in HMA materials overlaying cracked and jointed underlying pavements. The high concentration of stresses and strains in the vicinity of the discontinuity of the old pavement causes the cracks to reflect into the newly placed HMA overlay. While it is a common practice to use skewed transverse joints in rigid pavements to improve the latter's performance, the impact of such a practice on the cracking of a potential HMA overlay has not been examined so far. In this context, this study investigates the effect of using skewed transverse joints in rigid pavements on reflective cracking development in the HMA overlay. Advanced three-dimensional Finite Element models including viscoelastic material properties for the HMA overlay, 3D beam modeling of dowel bars, non-uniform tire-pavement contact stresses, friction interfaces, and infinite boundary elements were constructed for both normal and skewed transverse joints using ABAQUS v-6.11. The potential ...

  3. Overlay removable denture for treatment of worn teeth.

    Science.gov (United States)

    Beyth, Nurit; Tamari, Israel; Buller Sharon, Anat

    2014-01-01

    Rehabilitation of partially edentulous patients with excessively worn dentitions can be challenging. Factors including medical history as well as the cost of the treatment and patient wishes for simpler approaches must be considered. This manuscript describes the use of an overlay partial denture to treat patients with excessive wear of the maxillary teeth. We describe a technique to restore severely worn teeth using heat-cured acrylic as part of a partial or full denture. Minimal preparations of the teeth are required, and the restoration provides protection from further wear, and stabilizes the occlusion. This solution was functionally and esthetically suitable to the patients. The technique can be used in medically complex patients where extractions are contraindicated, such as post radiation therapy or bisphosphonate treatment.

  4. Ubiquitous map-image access through wireless overlay networks

    Science.gov (United States)

    Cai, Jianfei; Huang, Haijie; Ni, Zefeng; Chen, Chang Wen

    2004-10-01

    With the availability of various wireless link-layer technologies, such as Bluetooth, WLAN and GPRS, in one wireless device, ubiquitous communications can be realized through managing vertical handoff in the environment of wireless overlay networks. In this paper, we propose a vertical handoff management system based on mobile IPv6, which can automatically manage the multiple network interfaces on the mobile device, and make decisions on network interface selection according to the current situation. Moreover, we apply our proposed vertical handoff management with JPEG-2000 codec to the wireless application of map image access. The developed system is able to provide seamless communications, as well as fast retrieve any interested map region with any block size, in different resolutions and different color representations directly from the compressed bitstream.

  5. Range of slow positrons in metal overlayers on Al

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, B.; Lynn, K.G.; Leung, T.C. (Brookhaven National Laboratory, Upton, New York 11973 (USA)); Van der Kolk, G.J.; Van Ijzendoorn, L.J. (Philips Research Laboratories, 5600 JA Eindhoven, (Netherlands))

    1990-02-19

    Polycrystalline Pd and amorphous PdTa films on Al substrates were studied by a variable energy positron beam and by Rutherford backscattering. Since positron diffusion in the overlayers is limited, the range follows directly from the Doppler broadening as a function of incident positron energy. To observe possible effects of positron backscattering, a sandwich of Al/Pd/Al was studied as well. It was found that the mean penetration depth is not described well by {bar {ital z}}({ital E})={ital A}({mu}g/cm{sup 2}){times}{ital E}{sup {ital n}({ital E})}, if {ital A} and {ital n} are assumed to be material and energy independent.

  6. Complete Imageless solution for overlay front-end manufacturing

    Science.gov (United States)

    Herisson, David; LeCacheux, Virginie; Touchet, Mathieu; Vachellerie, Vincent; Lecarpentier, Laurent; Felten, Franck; Polli, Marco

    2005-09-01

    Imageless option of KLA-Tencor RDM system (Recipe Data Management) is a new method of recipe creation, using only the mask design to define alignment target and measurement parameters. This technique is potentially the easiest tool to improve recipe management of a large amount of products in logic fab. Overlay recipes are created without wafer, by using a synthetic image (copy of gds mask file) for alignment pattern and target design like shape (frame in frame) and size for the measurement. A complete gauge study on critical CMOS 90nm Gate level has been conducted to evaluate reliability and robustness of the imageless recipe. We show that Imageless limits drastically the number of templates used for recipe creation, and improves or maintains measurement capability compare to manual recipe creation (operator dependant). Imageless appears to be a suitable solution for high volume manufacturing, as shown by the results obtained on production lots.

  7. Performance Analysis of Vertical Handover Strategy for Heterogeneous Overlay Network

    Institute of Scientific and Technical Information of China (English)

    BINGHongyan; HEChen; JIANGLingge

    2004-01-01

    Future wireless networks are envisioned to integrate cellular network and hot spots (e.g. ultrawideband network, UWB) in virtue of the individual coverage and capacity complementary characteristics. In this heterogeneous overlay network, seamless Vertical handover (VHO) is one of the important issues because users expect to be provided with continuous service at anytime, anywhere. This paper presents an analytical vertical handover initiation model based on Received signal strength(RSS) criterion and network blocking probability criterion. Meanwhile, the handover performance criteria of interest are: the handover probability and call-dropping probability. The analytical formulas are derived in details and the handover performance is evaluated by computer simulations. The simulation results show that our model can give improved performance compared with vertical HO algorithm only based on RSS criterion and can perform well when UWB hot spot is in heavy network load.

  8. Overlay cognitive radio systems with adaptive two-way relaying

    KAUST Repository

    Hyadi, Amal

    2013-12-01

    In this paper, we propose a spectrum sharing mechanism with a two-phase two-way relaying protocol for an overlay cognitive network. The system comprises two primary users (PUs) and two secondary users (SUs). One of the SUs acts as a relay for the PUs and gains spectrum sharing as long as he respects outage probability constraints of the primary system. Moreover, we consider that the relaying node performs an optimal power allocation scheme that minimizes the outage performance of the secondary receiver. Closed form expressions for the outage probability are derived for the cases of Decode-and-Forward (DF), Amplify-and-Forward (AF), and adaptive relaying. Numerical simulations are presented to illustrate and compare the obtained results. © 2013 IEEE.

  9. Computer vision and soft computing for automatic skull-face overlay in craniofacial superimposition.

    Science.gov (United States)

    Campomanes-Álvarez, B Rosario; Ibáñez, O; Navarro, F; Alemán, I; Botella, M; Damas, S; Cordón, O

    2014-12-01

    Craniofacial superimposition can provide evidence to support that some human skeletal remains belong or not to a missing person. It involves the process of overlaying a skull with a number of ante mortem images of an individual and the analysis of their morphological correspondence. Within the craniofacial superimposition process, the skull-face overlay stage just focuses on achieving the best possible overlay of the skull and a single ante mortem image of the suspect. Although craniofacial superimposition has been in use for over a century, skull-face overlay is still applied by means of a trial-and-error approach without an automatic method. Practitioners finish the process once they consider that a good enough overlay has been attained. Hence, skull-face overlay is a very challenging, subjective, error prone, and time consuming part of the whole process. Though the numerical assessment of the method quality has not been achieved yet, computer vision and soft computing arise as powerful tools to automate it, dramatically reducing the time taken by the expert and obtaining an unbiased overlay result. In this manuscript, we justify and analyze the use of these techniques to properly model the skull-face overlay problem. We also present the automatic technical procedure we have developed using these computational methods and show the four overlays obtained in two craniofacial superimposition cases. This automatic procedure can be thus considered as a tool to aid forensic anthropologists to develop the skull-face overlay, automating and avoiding subjectivity of the most tedious task within craniofacial superimposition. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Adsorption and dissociation of SO3 on N-doped TiO2 supported Au overlayers investigated by van der Waals corrected DFT

    Science.gov (United States)

    Abbasi, Amirali; Sardroodi, Jaber Jahanbin

    2017-09-01

    We present a density functional theory (DFT) study of the reactivity towards SO3 adsorption and dissociation over the TiO2 supported Au overlayers. We model different adsorption configurations of SO3 on the considered structures. For all adsorption systems, we find that the interaction of SO3 molecule with the surfaces of Au atoms is strongly favored. On the TiO2 supported Au overlayer, SO3 also dissociated into SO2 and adsorbed atomic oxygen. The atomic oxygen binds directly to the Au atoms. The structural properties are explained in terms of the bond lengths, bond angles and adsorption energies. The electronic structure of the system and Mulliken population analysis were also studied for the discussion of results. The results indicate that the SO3 interaction with N-doped TiO2-supported Au overlayer is more favorable in energy than the interaction with undoped one, suggesting the increased sensing capability of N-doped TiO2-supported Au towards detection of SO3 molecule. The oxygen atoms of the SO3 molecule bind to the Au and Ti atoms of the TiO2 supported Au overlayer in a bridge geometry. The significant overlaps in the PDOSs of the Au and oxygen atoms of the SO3 molecule, as well as titanium and oxygen atoms indicate the formation of chemical bonds between these atoms. Our DFT study therefore provides a theoretical basis for why the reactivity of SO3 molecule with N-doped TiO2 supported Au overlayer may increase, thus being a helpful procedure in the development of efficient sensor devices for SO3 detection.

  11. Structural studies of molecular and metallic overlayers using angle- resolved photoemission extended fine structure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z.

    1992-10-01

    Angle-resolved photoemission extended fine structure (ARPEFS) was used to study molecular and metallic overlayers on metal surfaces through analysis of p2mg(2[times]1)CO/Ni(110) and the p(2[times]2)K/Ni(111) adsorption. For the dense p2mg(2[times]1)CO/Ni(110) surface layer, photoemission intensities from C 1s level were measured in three directions at photoelectron kinetic energies 60-400 eV. Using multiple-scattering spherical-wave (MSSW) modeling, it was found that CO molecules are adsorbed on short-bridge sites, with adjacent CO along the [110] direction displaced alternatively in opposite directions towards the [001] azimuths to form a zigzag chain geometry. The tilt angle is 16[plus minus]2[degree] from the surface normal for the direction linking the C atom and the center of the Ni bridge. The carbon C-Ni interatomic distance was determined to be 1.94[plus minus]0.02[Angstrom]. The first- to second-layer spacing of Ni is 1.27[plus minus]0.04[Angstrom], up from 1.10[Angstrom] for the clean Ni(110) surface, but close to the 1.25[Angstrom] Ni interlayer spacing in the bulk. The C-O bond length and tilt angle were varied within small ranges (1.10--1.20[Angstrom] and 15--23[degrees]) in our MSSW simulations. Best agreement between experiment and simulations was achieved at 1.16[Angstrom] and 19[degrees]. This yields an O-O distance of 2.95[Angstrom] for the two nearest CO molecules, (van der Waals' radius [approximately] 1.5 [Angstrom] for oxygen). Two different partial-wave phase-shifts were used in MSSW, and structural results from both are in very good agreement. For the p(2[times]2)K/Ni(111) overlayer, ARPEFS [chi](k) curves from K 1s level measured along [111] and [771] at 130K showed that the K atoms are preferentially adsorbed on the atop sites, in agreement with a LEED study of the same system.

  12. Structural studies of molecular and metallic overlayers using angle- resolved photoemission extended fine structure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z.

    1992-10-01

    Angle-resolved photoemission extended fine structure (ARPEFS) was used to study molecular and metallic overlayers on metal surfaces through analysis of p2mg(2{times}1)CO/Ni(110) and the p(2{times}2)K/Ni(111) adsorption. For the dense p2mg(2{times}1)CO/Ni(110) surface layer, photoemission intensities from C 1s level were measured in three directions at photoelectron kinetic energies 60-400 eV. Using multiple-scattering spherical-wave (MSSW) modeling, it was found that CO molecules are adsorbed on short-bridge sites, with adjacent CO along the [110] direction displaced alternatively in opposite directions towards the [001] azimuths to form a zigzag chain geometry. The tilt angle is 16{plus_minus}2{degree} from the surface normal for the direction linking the C atom and the center of the Ni bridge. The carbon C-Ni interatomic distance was determined to be 1.94{plus_minus}0.02{Angstrom}. The first- to second-layer spacing of Ni is 1.27{plus_minus}0.04{Angstrom}, up from 1.10{Angstrom} for the clean Ni(110) surface, but close to the 1.25{Angstrom} Ni interlayer spacing in the bulk. The C-O bond length and tilt angle were varied within small ranges (1.10--1.20{Angstrom} and 15--23{degrees}) in our MSSW simulations. Best agreement between experiment and simulations was achieved at 1.16{Angstrom} and 19{degrees}. This yields an O-O distance of 2.95{Angstrom} for the two nearest CO molecules, (van der Waals` radius {approximately} 1.5 {Angstrom} for oxygen). Two different partial-wave phase-shifts were used in MSSW, and structural results from both are in very good agreement. For the p(2{times}2)K/Ni(111) overlayer, ARPEFS {chi}(k) curves from K 1s level measured along [111] and [771] at 130K showed that the K atoms are preferentially adsorbed on the atop sites, in agreement with a LEED study of the same system.

  13. Curing units' ability to cure restorative composites and dual-cured composite cements under composite overlay.

    Science.gov (United States)

    Park, Sung-Ho; Kim, Su-Sun; Cho, Yong-Sik; Lee, Chang-Kyu; Noh, Byng-Duk

    2004-01-01

    This study compared the efficacy of using conventional low-power density QTH (LQTH) units, high-power density QTH (HQTH) units, argon (Ar) laser and Plasma arc curing (PAC) units for curing dual-cured resin cements and restorative resin composites under a pre-cured resin composite overlay. The microhardness of the two types of restorative resins (Z100 and Tetric Ceram) and a dual-cured resin cement (Variolink II) were measured after they were light cured for 60 seconds in a 2 mm Teflon mold. The recorded microhardness was determined to be the optimum microhard-ness (OM). Either one of the two types of restorative resins (Z100, Tetric Ceram) or the dual cured resin cement (Variolink II) were placed under a 1.5-mm thick and 8 mm diameter pre-cured Targis (Vivadent/Ivoclar AG, Schaan, Liechtenstein) overlay. The specimens that were prepared for each material were divided into four groups depending upon the curing units used (HQTH, PAC, Laser or LQTH) and were further subdi-vided into subgroups according to light curing time. The curing times used were 30, 60, 90 and 120 seconds for HQTH; 12, 24, 36 and 48 seconds for the PAC unit; 15, 30, 45 and 60 for the Laser and 60, 120 or 180 seconds for the LQTH unit. Fifteen specimens were assigned to each sub- group. The microhardness of the upper and and lower composite surfaces under the Targis overlay were measured using an Optidur Vickers hardness-measuring instrument (Göttfert Feinwerktechnik GmbH, Buchen, Germany). In each material, for each group, a three-way ANOVA with Tukey was used at the 0.05 level of significance to compare the microhardnesses of the upper and lower composite surfaces and the previously measured OM of the material. From the OM of each material, 80% OM was calculated and the time required for the microhardness of the upper and lower surface of the specimen to reach 100% and 80% of OM was determined. In Z100 and Tetric Ceram, when the composites were light cured for 120 seconds using the HQTH lamp

  14. Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Gonzalez, C. [Centro de Ingenieria y Desarrollo Industrial, Pie de la Cuesta No. 702, Desarrollo San Pablo, Queretaro, Qro. 76130 (Mexico)]. E-mail: crubio@cidesi.mx; Gomez-Rosas, G. [Departamento de Ciencias Exactas y Tecnologicas, Centro Universitario de los Lagos, Universidad de Guadalajara. Lagos de Moreno Jal. (Mexico); Ocana, J.L. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Molpeceres, C. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Banderas, A. [Centro de Ingenieria y Desarrollo Industrial, Pie de la Cuesta No. 702, Desarrollo San Pablo, Queretaro, Qro. 76130 (Mexico); Porro, J. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain); Morales, M. [Departamento de Fisica Aplicada a la Ingenieria Industrial, E.T.S.I.I. Universidad Politecnica de Madrid (Spain)

    2006-07-15

    Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm{sup 2} with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy.

  15. Reduction of wafer-edge overlay errors using advanced correction models, optimized for minimal metrology requirements

    Science.gov (United States)

    Kim, Min-Suk; Won, Hwa-Yeon; Jeong, Jong-Mun; Böcker, Paul; Vergaij-Huizer, Lydia; Kupers, Michiel; Jovanović, Milenko; Sochal, Inez; Ryan, Kevin; Sun, Kyu-Tae; Lim, Young-Wan; Byun, Jin-Moo; Kim, Gwang-Gon; Suh, Jung-Joon

    2016-03-01

    In order to optimize yield in DRAM semiconductor manufacturing for 2x nodes and beyond, the (processing induced) overlay fingerprint towards the edge of the wafer needs to be reduced. Traditionally, this is achieved by acquiring denser overlay metrology at the edge of the wafer, to feed field-by-field corrections. Although field-by-field corrections can be effective in reducing localized overlay errors, the requirement for dense metrology to determine the corrections can become a limiting factor due to a significant increase of metrology time and cost. In this study, a more cost-effective solution has been found in extending the regular correction model with an edge-specific component. This new overlay correction model can be driven by an optimized, sparser sampling especially at the wafer edge area, and also allows for a reduction of noise propagation. Lithography correction potential has been maximized, with significantly less metrology needs. Evaluations have been performed, demonstrating the benefit of edge models in terms of on-product overlay performance, as well as cell based overlay performance based on metrology-to-cell matching improvements. Performance can be increased compared to POR modeling and sampling, which can contribute to (overlay based) yield improvement. Based on advanced modeling including edge components, metrology requirements have been optimized, enabling integrated metrology which drives down overall metrology fab footprint and lithography cycle time.

  16. Tl overlayers on Si(1-bar 0-bar 0) and their self-assembly induced by STM tip

    Energy Technology Data Exchange (ETDEWEB)

    Kishida, M. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)]. E-mail: kishida@ele.eng.osaka-u.ac.jp; Saranin, A.A. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Institute of Automation and Control Processes, 690041 Vladivostok (Russian Federation); Faculty of Physics and Engineering, Far Eastern State University, 690000 Vladivostok (Russian Federation); Zotov, A.V. [Faculty of Physics and Engineering, Far Eastern State University, 690000 Vladivostok (Russian Federation); Kotlyar, V.G. [Institute of Automation and Control Processes, 690041 Vladivostok (Russian Federation); Nishida, A. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Murata, Y. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Okado, H. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Katayama, M. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Oura, K. [Department of Electronic Engineering, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)

    2004-10-15

    Formation of the thallium (Tl) overlayers on the Si(1-bar 0-bar 0) 2x1 surface has been studied using scanning tunneling microscopy (STM). It has been found that adsorption of Tl atom involves a charge transfer leading to the development of a static dipole which is responsible for the field-assisted migration of the Tl adsorbate on the surface. When the STM tip bias voltage is positive, Tl atoms are repelled out from the region underneath the tip apex. In the case of the negative bias voltage, Tl is accumulated underneath the tip. Thus, the observed structure of the surface is controlled not only by Tl coverage, but also by the STM bias voltage and tunneling current.

  17. Prosthodontic management of worn dentition in pediatric patient with complete overlay dentures: a case report.

    Science.gov (United States)

    Kumar, Prince; Rastogi, Jyoti; Jain, Chandni; Singh, Harkanwal Preet

    2012-11-01

    Overlay complete dentures are simple, reversible and economical treatment modality for patients with congenital or acquired disorders that severely affect the tooth development. It satisfies both the esthetic and functional demands where the extraction of teeth is not generally indicated. In pediatric patients, the overlay dentures establish a relatively stable occlusion that improves patient's tolerance to the future treatment procedures for worn dentition. This clinical report highlights the imperative need of appropriate treatment strategy and application of maxillary and mandibular overlay dentures in a pediatric patient who suffered from congenitally mutilated and worn dentition.

  18. An algorithm of multi-model spatial overlay based on three-dimensional terrain model TIN and its application

    Institute of Scientific and Technical Information of China (English)

    王少安; 张子平; 龚健雅

    2001-01-01

    3D-GIS spatial overlay analysis is being broadly concerned about in international academe and is a research focus. It is one of the important functions of spatial analysis using GIS technology. An algorithm of multi-model spatial overlay based on three-dimensional terrain model TIN is introduced in this paper which can be used to solve the TIN-based thrcc-dimensional overlay operation in spatial analysis. The feasibility arid validity of this algorithm is identified. This algorithm is used successfully in three-dimensional overlay and region variation overlay analysis.

  19. An algorithm of multi-model spatial overlay based on three-dimensional terrain model TIN and its application

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-an; ZHANG Zi-ping; GONG Jian-ya

    2001-01-01

    3D-GIS spatial overlay analysis is being broadly concerned about in in ternational academe and is a research focus. It is one of the important function s of spatial analysis using GIS technology. An algorithm of multi-model spatial overlay based on three-dimensional terrain model TIN is introduced in this pape r which can be used to solve the TIN-based three-dimensional overlay operation in spatial analysis. The feasibility and validity of this algorithm is identified. This algorithm is used successfully in three-dimensional overlay and region va riation overlay analysis.

  20. Synchrotron radiation photoemission study of metal overlayers on hydrogenated amorphous silicon at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pi, J.

    1990-09-21

    In this dissertation, metals deposited on a hydrogenated amorphous silicon (a-Si:H) film at room temperature are studied. The purpose of this work is mainly understanding the electronic properties of the interface, using high-resolution synchrotron radiation photoemission techniques as a probe. Atomic hydrogen plays an important role in passivating dangling bonds of a-Si:H films, thus reducing the gap-state distribution. In addition, singly bonded hydrogen also reduces states at the top of the valence band which are now replaced by deeper Si-H bonding states. The interface is formed by evaporating metal on an a-Si:H film in successive accumulations at room temperature. Au, Ag, and Cr were chosen as the deposited metals. Undoped films were used as substrates. Since some unique features can be found in a-Si:H, such as surface enrichment of hydrogen diffused from the bulk and instability of the free surface, we do not expect the metals/a-Si:H interface to behave exactly as its crystalline counterpart. Metal deposits, at low coverages, are found to gather preferentially around regions deficient in hydrogen. As the thickness is increased, some Si atoms in those regions are likely to leave their sites to intermix with metal overlayers like Au and Cr. 129 refs., 30 figs.

  1. Optical resonance analysis of reflected long period fiber gratings with metal film overlay

    Science.gov (United States)

    Zhang, Guiju; Cao, Bing; Wang, Chinua; Zhao, Minfu

    2008-11-01

    We present the experimental results of a novel single-ended reflecting surface plasma resonance (SPR) based long period fiber grating (LPFG) sensor. A long period fiber grating sensing device is properly designed and fabricated with a pulsed CO2 laser writing system. Different nm-thick thin metal films are deposited on the fiber cladding and the fiber end facet for the excitation of surface plasma waves (SPWs) and the reflection of the transmission spectrum of the LPFG with doubled interaction between metal-dielectric interfaces of the fiber to enhance the SPW of the all-fiber SPR-LPFG sensing system. Different thin metal films with different thicknesses are investigated. The effect of the excited SPW transmission along the fiber cladding-metal interface with silver and aluminum films is observed. It is found that different thicknesses of the metal overlay show different resonant behaviors in terms of resonance peak situation, bandwidth and energy loss. Within a certain range, thinner metal film shows narrower bandwidth and deeper peak loss.

  2. Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O2 molecules.

    Science.gov (United States)

    Friedlein, R; Van Bui, H; Wiggers, F B; Yamada-Takamura, Y; Kovalgin, A Y; de Jong, M P

    2014-05-28

    As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O2 molecules, as well as the combination of both, with epitaxial silicene on thin ZrB2(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O2 gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O2 molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.

  3. An optimal light-extracting overlayer, inspired by the lantern of a Photuris firefly, to improve the external efficiency of existing light-emitting diodes

    CERN Document Server

    Bay, Annick; Sarrazin, Michael; Belarouci, Ali; Aimez, Vincent; Francis, Laurent A; Vigneron, Jean Pol

    2012-01-01

    Actual light emission diodes (LED) have most often good internal efficiencies but poor external efficiencies due to total internal reflection at the air interface. In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is investigated. The purpose of this overlayer is to improve light extraction into air, after the photons have been generated in the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp., described by Bay et al. : a surface with an asymmetrical triangular profile (a "factory-roof" shape), developed on the scale of a few micrometers, thus somewhat larger than usually suggested in the related literature. The profile of the overlayer corrugated surface of the coating film was copied from the natural model. Yet, the actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. The optimization proc...

  4. A genetic algorithm for flexible molecular overlay and pharmacophore elucidation

    Science.gov (United States)

    Jones, Gareth; Willett, Peter; Glen, Robert C.

    1995-12-01

    A genetic algorithm (GA) has been developed for the superimposition of sets of flexible molecules. Molecules are represented by a chromosome that encodes angles of rotation about flexible bonds and mappings between hydrogen-bond donor proton, acceptor lone pair and ring centre features in pairs of molecules. The molecule with the smallest number of features in the data set is used as a template, onto which the remaining molecules are fitted with the objective of maximising structural equivalences. The fitness function of the GA is a weighted combination of: (i) the number and the similarity of the features that have been overlaid in this way; (ii) the volume integral of the overlay; and (iii) the van der Waals energy of the molecular conformations defined by the torsion angles encoded in the chromosomes. The algorithm has been applied to a number of pharmacophore elucidation problems, i.e., angiotensin II receptor antagonists, Leu-enkephalin and a hybrid morphine molecule, 5-HT1D agonists, benzodiazepine receptor ligands, 5-HT3 antagonists, dopamine D2 antagonists, dopamine reuptake blockers and FKBP12 ligands. The resulting pharmacophores are generated rapidly and are in good agreement with those derived from alternative means.

  5. Quality metric for accurate overlay control in <20nm nodes

    Science.gov (United States)

    Klein, Dana; Amit, Eran; Cohen, Guy; Amir, Nuriel; Har-Zvi, Michael; Huang, Chin-Chou Kevin; Karur-Shanmugam, Ramkumar; Pierson, Bill; Kato, Cindy; Kurita, Hiroyuki

    2013-04-01

    The semiconductor industry is moving toward 20nm nodes and below. As the Overlay (OVL) budget is getting tighter at these advanced nodes, the importance in the accuracy in each nanometer of OVL error is critical. When process owners select OVL targets and methods for their process, they must do it wisely; otherwise the reported OVL could be inaccurate, resulting in yield loss. The same problem can occur when the target sampling map is chosen incorrectly, consisting of asymmetric targets that will cause biased correctable terms and a corrupted wafer. Total measurement uncertainty (TMU) is the main parameter that process owners use when choosing an OVL target per layer. Going towards the 20nm nodes and below, TMU will not be enough for accurate OVL control. KLA-Tencor has introduced a quality score named `Qmerit' for its imaging based OVL (IBO) targets, which is obtained on the-fly for each OVL measurement point in X & Y. This Qmerit score will enable the process owners to select compatible targets which provide accurate OVL values for their process and thereby improve their yield. Together with K-T Analyzer's ability to detect the symmetric targets across the wafer and within the field, the Archer tools will continue to provide an independent, reliable measurement of OVL error into the next advanced nodes, enabling fabs to manufacture devices that meet their tight OVL error budgets.

  6. Ultrasonic Evaluation of Two Dissimilar Metal Weld Overlay Specimens

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Cinson, Anthony D.; Prowant, Matthew S.; Moran, Traci L.; Anderson, Michael T.

    2012-06-30

    Two dissimilar metal weld (DMW) pipe-to-nozzle specimens were implanted with thermal fatigue cracks in the 13% to 90% through-wall depth range. The specimens were ultrasonically evaluated with phased-array probes having center frequencies of 0.8, 1.0, 1.5, and 2.0 megahertz (MHz). An Alloy 82/182 weld overlay (WOL) was applied and the specimens were ultrasonically re-evaluated for flaw detection and characterization. The Post-WOL flaw depths were approximately 10% to 56% through-wall. This study has shown the effectiveness of ultrasonic examinations of Alloy 82/182 overlaid DMW specimens. Phased-array probes with center frequency in the 0.8- to 1.0-MHz range provide a strong coherent signal but the greater ultrasonic wavelength and larger beam spot size prevent the reliable detection of small flaws. These small flaws had nominal through-wall depths of less than 15% and length in the 50-60 mm (2-2.4 in.) range. Flaws in the 19% and greater through-wall depth range were readily detected with all four probes. At the higher frequencies, the reflected signals are less coherent but still provide adequate signal for flaw detection and characterization. A single inspection at 2.0 MHz could provide adequate detection and sizing information but a supplemental inspection at 1.0 or 1.5 MHz is recommended.

  7. 64nm pitch metal1 double patterning metrology: CD and OVL control by SEMCD, image based overlay and diffraction based overlay

    Science.gov (United States)

    Ducoté, Julien; Dettoni, Florent; Bouyssou, Régis; Le-Gratiet, Bertrand; Carau, Damien; Dezauzier, Christophe

    2015-03-01

    Patterning process control of advanced nodes has required major changes over the last few years. Process control needs of critical patterning levels since 28nm technology node is extremely aggressive showing that metrology accuracy/sensitivity must be finely tuned. The introduction of pitch splitting (Litho-Etch-Litho-Etch) at 14FDSOInm node requires the development of specific metrologies to adopt advanced process control (for CD, overlay and focus corrections). The pitch splitting process leads to final line CD uniformities that are a combination of the CD uniformities of the two exposures, while the space CD uniformities are depending on both CD and OVL variability. In this paper, investigations of CD and OVL process control of 64nm minimum pitch at Metal1 level of 14FDSOI technology, within the double patterning process flow (Litho, hard mask etch, line etch) are presented. Various measurements with SEMCD tools (Hitachi), and overlay tools (KT for Image Based Overlay - IBO, and ASML for Diffraction Based Overlay - DBO) are compared. Metrology targets are embedded within a block instanced several times within the field to perform intra-field process variations characterizations. Specific SEMCD targets were designed for independent measurement of both line CD (A and B) and space CD (A to B and B to A) for each exposure within a single measurement during the DP flow. Based on those measurements correlation between overlay determined with SEMCD and with standard overlay tools can be evaluated. Such correlation at different steps through the DP flow is investigated regarding the metrology type. Process correction models are evaluated with respect to the measurement type and the intra-field sampling.

  8. ViTexOCR; a script to extract text overlays from digital video

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The ViTexOCR script presents a new method for extracting navigation data from videos with text overlays using optical character recognition (OCR) software. Over the...

  9. Computing a single cell in the overlay of two simple polygons

    NARCIS (Netherlands)

    Berg, M. de; Devillers, O.; Dobrindt, K.T.G.; Schwarzkopf, O.

    1997-01-01

    This note combines the lazy randomized incremental construction scheme with the technique of \\connectivity acceleration" to obtain an O ( n (log ? n ) 2 ) time randomized algorithm to compute a single face in the overlay oftwo simple polygons in the plane.

  10. FLUORESCENCE OVERLAY ANTIGEN MAPPING OF THE EPIDERMAL BASEMENT-MEMBRANE ZONE .2. COLOR FIDELITY

    NARCIS (Netherlands)

    BRUINS, S; DEJONG, MCJM; HEERES, K; WILKINSON, MHF; JONKMAN, MF; VANDERMEER, JB

    In this second report on the fluorescence overlay antigen mapping (FOAM) technique, we highlight some of the errors that may influence faithful color rendition of slide preparations using triple antigen immunofluorescence staining. Reliable interpretation of multicolor fluorescence images requires

  11. ONE YEAR PROSPECTIVE STUDY TO COMPARE UNDERLAY AND OVERLAY TECHNIQUES OF MYRINGOPLASTY

    National Research Council Canada - National Science Library

    Thomas Rony; Anil; Asha Annie; Jacob; Sajeev George

    2014-01-01

    ... to infection and improves hearing. Two basic techniques have come up in which the graft is placed either over the drum remnant or under the drum remnant and the techniques are called overlay and underlay respectively...

  12. Oral rehabilitation of a patient with amelogenesis imperfecta using removable overlay denture: a clinical report

    National Research Council Canada - National Science Library

    Ghodsi, S; Rasaeipour, S; Vojdani, M

    2012-01-01

    The aim of this study was oral rehabilitation of 17-year old patient with amelogenesis imperfecta using removable overlay denture in order to satisfy her esthetic and functional expectations and enhance her self-image...

  13. Viral Concentration Determination Through Plaque Assays: Using Traditional and Novel Overlay Systems

    National Research Council Canada - National Science Library

    Baer, Alan; Kehn-Hall, Kylene

    2014-01-01

    ... (infectious units and cellular dead zones) in cell culture. Here we demonstrate how to perform a basic plaque assay, and how differing overlays and techniques can affect plaque formation and production...

  14. An optimal algorithm based on extended kalman filter and the data fusion for infrared touch overlay

    Science.gov (United States)

    Zhou, AiGuo; Cheng, ShuYi; Pan, Qiang Biao; Sun, Dong Yu

    2016-01-01

    Current infrared touch overlay has problems on the touch point recognition which bring some burrs on the touch trajectory. This paper uses the target tracking algorithm to improve the recognition and smoothness of infrared touch overlay. In order to deal with the nonlinear state estimate problem for touch point tracking, we use the extended Kalman filter in the target tracking algorithm. And we also use the data fusion algorithm to match the estimate value with the original target trajectory. The experimental results of the infrared touch overlay demonstrate that the proposed target tracking approach can improve the touch point recognition of the infrared touch overlay and achieve much smoother tracking trajectory than the existing tracking approach.

  15. How to minimize CD variation and overlay degradation induced by film stress

    Science.gov (United States)

    Jung, Woo-Yung; Lim, Yong-Hyun; Park, Shin-Ae; Ahn, Sang-Joon; Lee, Ji-Hyun; Yoo, Jung-A.; Pyi, Seung-Ho; Kim, Jin-Woong

    2012-03-01

    It is getting harder to minimize feature size to satisfy bit growth requirement. 3D NAND flash memory has been developed to meet bit growth requirement without shrinking feature size. To increase the number of memory cells per unit area without shrinking feature size, we should increase the number of stacked film layers which finally become memory cells. Wafer warpage is induced by the stress between film and wafer. Both of film stress and wafer warpage increase in proportion to stacked film layers, and the increase of wafer warpage makes CD uniformity worse. Overlay degradation has no relation with wafer warpage, but has indirect relation with film stress. Wafer deformation in film deposition chamber is the source of overlay degradation. In this paper, we study the reasons why CD uniformity and overlay accuracy are affected by film stress, and suggest the methods which keep CD uniformity and overlay accuracy safe without additional processes.

  16. The Effect of Colored Overlays on Reading Fluency in Individuals with Dyslexia.

    Science.gov (United States)

    Denton, Tiffany Freeze; Meindl, James N

    2016-09-01

    Colored overlays, one type of tinted filter, are plastic reading sheets tinted with color and placed over text to eliminate or alleviate a wide range of reading difficulties such as low reading rate, accuracy, and comprehension. The effects of colored overlays on reading problems associated with dyslexia were investigated in this study via a multielement design. Reading fluency was assessed when participants read with and without colored overlays. Undifferentiated responding, or decreased accuracy, resulted across three participants, suggesting that colored overlays were ineffective and potentially detrimental to participants' reading abilities. As a result, empirically validated reading techniques were implemented across individuals. These findings are discussed and recommendations are made in regards to the use of research-based reading interventions.

  17. Development of Temper Bead Welding Process for Weld Overlay of Dissimilar Welds

    Energy Technology Data Exchange (ETDEWEB)

    Byeon, J. G.; Park, K. S.; Kim, Y. J. [Doosan Heavy Industries and Construction Co., Ltd., Seoul (Korea, Republic of)

    2008-10-15

    In recent years, the dissimilar weld metal used to connect stainless steel piping and low alloy steel or carbon steel components have experienced cracking in nuclear reactor piping systems. The cracking has been observed in several Pressurized Water Reactors in overseas. In Several cases, the cracking was repaired using structural weld overlays, a repair technique that has been in use in the U.S. in Boiling Water Reactors for over twenty years. Although weld overlays have been used primarily as a repair for flawed piping, they can also be applied at locations that have not yet exhibited any cracking, but are considered susceptible to cracking. The purpose of this research is to develop the temper bead weld process for the weld overlay of the dissimilar weld pipe. We developed equipment for the overlay system, applied Procedure Qualification(PQ) for the temper bead welding process.

  18. CHC: A Robust P2P Overlay Network with Simple Routing and Small-World Features

    Directory of Open Access Journals (Sweden)

    Wenjun Xiao

    2011-08-01

    Full Text Available Almost all recent researches on P2P systems focus on howto build a highly usable P2P overlay network. Researchersinclude small routing table, short query path and goodrobustness into their design objectives of overlay topology. Inthis paper, we present a general group theory method anddefine a new Cayley graph. Based on this Cayley graph, wepropose a novel P2P overlay network called CHC, which hassimple routing (searching scheme and many other excellentproperties such as short query path, high clustering and goodrobustness because of its symmetry. The performance isevaluated by simulation to show that CHC possesses shorterquery path length and higher clustering and better robustnessthan several popular P2P overlay networks such as Chord andUlysses.

  19. Computing a single cell in the overlay of two simple polygons

    NARCIS (Netherlands)

    Berg, M. de; Devillers, O.; Dobrindt, K.T.G.; Schwarzkopf, O.

    2001-01-01

    This note combines the lazy randomized incremental construction scheme with the technique of \\connectivity acceleration" to obtain an O ( n (log ? n ) 2 ) time randomized algorithm to compute a single face in the overlay oftwo simple polygons in the plane.

  20. OVERLAY NETWORKS APPLICATION MODEL FOR MILITARY TRAFFIC%Overlay Networks在军事通信中的应用模型

    Institute of Scientific and Technical Information of China (English)

    孙晓; 王晖

    2008-01-01

    首先简单介绍了Overlay Networks,然后分析了当前军事通信的弊端和未来发展趋势,提出采用Overlay Networks的思想,提升军事通信网络的性能,为未来信息化战争提供网络基础架构.最后分析了该应用模型的优点和亟待解决的几个问题.

  1. Vanadium and molybdenum oxide thin films on Au(111). Growth and surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Guimond, Sebastien

    2009-06-04

    The growth and the surface structure of well-ordered V{sub 2}O{sub 3}, V{sub 2}O{sub 5} and MoO{sub 3} thin films have been investigated in this work. These films are seen as model systems for the study of elementary reaction steps occurring on vanadia and molybdena-based selective oxidation catalysts. It is shown that well-ordered V{sub 2}O{sub 3}(0001) thin films can be prepared on Au(111). The films are terminated by vanadyl groups which are not part of the V{sub 2}O{sub 3} bulk structure. Electron irradiation specifically removes the oxygen atoms of the vanadyl groups, resulting in a V-terminated surface. The fraction of removed vanadyl groups is controlled by the electron dose. Such surfaces constitute interesting models to probe the relative role of both the vanadyl groups and the undercoordinated V ions at the surface of vanadia catalysts. The growth of well-ordered V{sub 2}O{sub 5}(001) and MoO{sub 3}(010) thin films containing few point defects is reported here for the first time. These films were grown on Au(111) by oxidation under 50 mbar O{sub 2} in a dedicated high pressure cell. Contrary to some of the results found in the literature, the films are not easily reduced by annealing in UHV. This evidences the contribution of radiation and surface contamination in some of the reported thermal reduction experiments. The growth of ultrathin V{sub 2}O{sub 5} and MoO{sub 3} layers on Au(111) results in formation of interface-specific monolayer structures. These layers are coincidence lattices and they do not correspond to any known oxide bulk structure. They are assumed to be stabilized by electronic interaction with Au(111). Their formation illustrates the polymorphic character and the ease of coordination units rearrangement which are characteristic of both oxides. The formation of a second layer apparently precedes the growth of bulk-like crystallites for both oxides. This observation is at odds with a common assumption that crystals nucleate as soon as a

  2. Combined Excimer Laser Photoablation and Amniotic Membrane Overlay for Relief of Symptomatic Discomfort in Gelatinous Drop-like Corneal Dystrophy.

    Science.gov (United States)

    Alex, Anne F; Eter, Nicole; Uhlig, Constantin E

    2015-10-01

    To describe the efficacy of combined excimer laser photoablation and amniotic overlay membrane in the relief of symptomatic discomfort in a 17-year-old patient who had gelatinous drop-like corneal dystrophy. The best-corrected visual acuity (BCVA) was measured with Snellen letters. Slit-lamp examination of the ocular surface and anterior chamber was performed at baseline. Results were photodocumented. Excimer laser photoablation was performed and subsequently 2 amniotic membranes were transconjunctivally fixated with 10.0 nylon sutures. Investigations and documentation were performed at baseline, every 2 months in the first year, and then every 6 months. The duration of follow-up was 22 months. At baseline, the BCVA was 20/70 in the right eye and 20/200 in the left eye. The patient reported distinct photophobia. Slit-lamp examination was difficult because of blepharospasm. Although gelatinous drops developed again and the BCVA decreased to 2/200, the patient reported significant relief after both microsurgical treatments and remained comfortable at 20 and 22 months. Excimer laser photocoagulation combined with amniotic membrane overlay does not stop the development of gelatinous drop-like corneal dystrophy but may improve subjective comfort. Such treatment does not hinder subsequent lamellar or penetrating grafts and is helpful in providing the necessary time for preparation of matched keratoplasties.

  3. Sol-Gel-Based Titania-Silica Thin Film Overlay for Long Period Fiber Grating-Based Biosensors.

    Science.gov (United States)

    Chiavaioli, Francesco; Biswas, Palas; Trono, Cosimo; Jana, Sunirmal; Bandyopadhyay, Somnath; Basumallick, Nandini; Giannetti, Ambra; Tombelli, Sara; Bera, Susanta; Mallick, Aparajita; Baldini, Francesco

    2015-12-15

    An evanescent wave optical fiber biosensor based on titania-silica-coated long period grating (LPG) is presented. The chemical overlay, which increases the refractive index (RI) sensitivity of the sensor, consists of a sol-gel-based titania-silica thin film, deposited along the sensing portion of the fiber by means of the dip-coating technique. Changing both the sol viscosity and the withdrawal speed during the dip-coating made it possible to adjust the thickness of the film overlay, which is a crucial parameter for the sensor performance. After the functionalization of the fiber surface using a methacrylic acid/methacrylate copolymer, an antibody/antigen (IgG/anti-IgG) assay was carried out to assess the performance of sol-gel based titania-silica-coated LPGs as biosensors. The analyte concentration was determined from the wavelength shift at the end of the binding process and from the initial binding rate. This is the first time that a sol-gel based titania-silica-coated LPG is proposed as an effective and feasible label-free biosensor. The specificity of the sensor was validated by performing the same model assay after spiking anti-IgG into human serum. With this structured LPG, detection limits of the order of tens of micrograms per liter (10(-11) M) are attained.

  4. Bullet: high bandwidth data dissemination using an overlay mesh

    OpenAIRE

    Kostic, D.; Rodriguez, A.; J. Albrecht; Vahdat, A.

    2003-01-01

    In recent years, overlay networks have become an effective alternative to IP multicast for efficient point to multipoint communication across the Internet. Typically, nodes self-organize with the goal of forming an efficient overlay tree, one that meets performance targets without placing undue burden on the underlying network. In this paper, we target high-bandwidth data distribution from a single source to a large number of receivers. Applications include large-file transfers and real-time ...

  5. On cooperative and efficient overlay network evolution based on a group selection pattern.

    Science.gov (United States)

    Wang, Yufeng; Nakao, Akihiro

    2010-06-01

    In overlay networks, the interplay between network structure and dynamics remains largely unexplored. In this paper, we study dynamic coevolution between individual rational strategies (cooperative or defect) and the overlay network structure, that is, the interaction between peer's local rational behaviors and the emergence of the whole network structure. We propose an evolutionary game theory (EGT)-based overlay topology evolution scheme to drive a given overlay into the small-world structure (high global network efficiency and average clustering coefficient). Our contributions are the following threefold: From the viewpoint of peers' local interactions, we explicitly consider the peer's rational behavior and introduce a link-formation game to characterize the social dilemma of forming links in an overlay network. Furthermore, in the evolutionary link-formation phase, we adopt a simple economic process: Each peer keeps one link to a cooperative neighbor in its neighborhood, which can slightly speed up the convergence of cooperation and increase network efficiency; from the viewpoint of the whole network structure, our simulation results show that the EGT-based scheme can drive an arbitrary overlay network into a fully cooperative and efficient small-world structure. Moreover, we compare our scheme with a search-based economic model of network formation and illustrate that our scheme can achieve the experimental and analytical results in the latter model. In addition, we also graphically illustrate the final overlay network structure; finally, based on the group selection model and evolutionary set theory, we theoretically obtain the approximate threshold of cost and draw the conclusion that the small value of the average degree and the large number of the total peers in an overlay network facilitate the evolution of cooperation.

  6. Shadow Segmentation and Augmentation Using á-overlay Models that Account for Penumbra

    DEFF Research Database (Denmark)

    Nielsen, Michael; Madsen, Claus B.

    2006-01-01

    that an augmented virtual object can cast an exact shadow. The penumbras (half-shadows) must be taken into account so that we can model the soft shadows.We hope to achieve this by modelling the shadow regions (umbra and penumbra alike) with a transparent overlay. This paper reviews the state-of-the-art shadow...... theories and presents two overlay models. These are analyzed analytically in relation to color theory and tangibility....

  7. Application of overlay modeling and control with Zernike polynomials in an HVM environment

    Science.gov (United States)

    Ju, JaeWuk; Kim, MinGyu; Lee, JuHan; Nabeth, Jeremy; Jeon, Sanghuck; Heo, Hoyoung; Robinson, John C.; Pierson, Bill

    2016-03-01

    Shrinking technology nodes and smaller process margins require improved photolithography overlay control. Generally, overlay measurement results are modeled with Cartesian polynomial functions for both intra-field and inter-field models and the model coefficients are sent to an advanced process control (APC) system operating in an XY Cartesian basis. Dampened overlay corrections, typically via exponentially or linearly weighted moving average in time, are then retrieved from the APC system to apply on the scanner in XY Cartesian form for subsequent lot exposure. The goal of the above method is to process lots with corrections that target the least possible overlay misregistration in steady state as well as in change point situations. In this study, we model overlay errors on product using Zernike polynomials with same fitting capability as the process of reference (POR) to represent the wafer-level terms, and use the standard Cartesian polynomials to represent the field-level terms. APC calculations for wafer-level correction are performed in Zernike basis while field-level calculations use standard XY Cartesian basis. Finally, weighted wafer-level correction terms are converted to XY Cartesian space in order to be applied on the scanner, along with field-level corrections, for future wafer exposures. Since Zernike polynomials have the property of being orthogonal in the unit disk we are able to reduce the amount of collinearity between terms and improve overlay stability. Our real time Zernike modeling and feedback evaluation was performed on a 20-lot dataset in a high volume manufacturing (HVM) environment. The measured on-product results were compared to POR and showed a 7% reduction in overlay variation including a 22% terms variation. This led to an on-product raw overlay Mean + 3Sigma X&Y improvement of 5% and resulted in 0.1% yield improvement.

  8. Application Oriented Flow Routing Algorithm for VoIP Overlay Networks

    Science.gov (United States)

    Wipusitwarakun, Komwut; Chimmanee, Sanon

    Overlay networks which are dynamically created over underlying IP networks are becoming widely used for delivering multimedia contents since they can provide several additional user-definable services. Multiple overlay paths between a source-destination overlay node pair are designed to improve service robustness against failures and bandwidth fluctuation of the underlying networks. Multimedia traffic can be distributed over those multiple paths in order to maximize paths' utilization and to increase application throughputs. Most of flow-based routing algorithms consider only common metrics such as paths' bandwidth or delay, which may be effective for data applications but not for real-time applications such as Voice over IP (VoIP), in which different levels of such performance metrics may give the same level of the performance experienced by end users. This paper focuses on such VoIP overlay networks and proposes a novel alternative path based flow routing algorithm using an application-specific traffic metric, i.e. “VoIP Path Capacity (VPCap), ” to calculate the maximum number of QoS satisfied VoIP flows which may be distributed over each available overlay path at a moment. The simulation results proved that more QoS-satisfied VoIP sessions can be established over the same multiple overlay paths, comparing to traditional approaches.

  9. Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

    Energy Technology Data Exchange (ETDEWEB)

    Beushausen, Hans, E-mail: hans.beushausen@uct.ac.za; Chilwesa, Masuzyo

    2013-11-15

    Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.

  10. VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.

    Science.gov (United States)

    Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu

    2015-01-01

    Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution.

  11. VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.

    Directory of Open Access Journals (Sweden)

    Weidong Gu

    Full Text Available Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs, i.e., multicast VMs (MVMs and compensation VMs (CVMs. MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD, and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast. The results show that it can obviously enhance the stability of the data distribution.

  12. Error analysis of overlay compensation methodologies and proposed functional tolerances for EUV photomask flatness

    Science.gov (United States)

    Ballman, Katherine; Lee, Christopher; Dunn, Thomas; Bean, Alexander

    2016-05-01

    Due to the impact on image placement and overlay errors inherent in all reflective lithography systems, EUV reticles will need to adhere to flatness specifications below 10nm for 2018 production. These single value metrics are near impossible to meet using current tooling infrastructure (current state of the art reticles report P-V flatness ~60nm). In order to focus innovation on areas which lack capability for flatness compensation or correction, this paper redefines flatness metrics as being "correctable" vs. "non-correctable" based on the surface topography's contributions to the final IP budget at wafer, as well as whether data driven corrections (write compensation or at scanner) are available for the reticle's specific shape. To better understand and define the limitations of write compensation and scanner corrections, an error budget for processes contributing to these two methods is presented. Photomask flatness measurement tools are now targeting 6σ reproducibility <1nm (previous 3σ reproducibility ~3nm) in order to drive down error contributions and provide more accurate data for correction techniques. Taking advantage of the high order measurement capabilities of improved metrology tooling, as well as computational capabilities which enable fast measurements and analysis of sophisticated shapes, we propose a methodology for the industry to create functional tolerances focused on the flatness errors that are not correctable with compensation.

  13. A hybrid solution using computational prediction and measured data to accurately determine process corrections with reduced overlay sampling

    Science.gov (United States)

    Noyes, Ben F.; Mokaberi, Babak; Mandoy, Ram; Pate, Alex; Huijgen, Ralph; McBurney, Mike; Chen, Owen

    2017-03-01

    Reducing overlay error via an accurate APC feedback system is one of the main challenges in high volume production of the current and future nodes in the semiconductor industry. The overlay feedback system directly affects the number of dies meeting overlay specification and the number of layers requiring dedicated exposure tools through the fabrication flow. Increasing the former number and reducing the latter number is beneficial for the overall efficiency and yield of the fabrication process. An overlay feedback system requires accurate determination of the overlay error, or fingerprint, on exposed wafers in order to determine corrections to be automatically and dynamically applied to the exposure of future wafers. Since current and future nodes require correction per exposure (CPE), the resolution of the overlay fingerprint must be high enough to accommodate CPE in the overlay feedback system, or overlay control module (OCM). Determining a high resolution fingerprint from measured data requires extremely dense overlay sampling that takes a significant amount of measurement time. For static corrections this is acceptable, but in an automated dynamic correction system this method creates extreme bottlenecks for the throughput of said system as new lots have to wait until the previous lot is measured. One solution is using a less dense overlay sampling scheme and employing computationally up-sampled data to a dense fingerprint. That method uses a global fingerprint model over the entire wafer; measured localized overlay errors are therefore not always represented in its up-sampled output. This paper will discuss a hybrid system shown in Fig. 1 that combines a computationally up-sampled fingerprint with the measured data to more accurately capture the actual fingerprint, including local overlay errors. Such a hybrid system is shown to result in reduced modelled residuals while determining the fingerprint, and better on-product overlay performance.

  14. Using the overlay assay to qualitatively measure bacterial production of and sensitivity to pneumococcal bacteriocins.

    Science.gov (United States)

    Maricic, Natalie; Dawid, Suzanne

    2014-09-30

    Streptococcus pneumoniae colonizes the highly diverse polymicrobial community of the nasopharynx where it must compete with resident organisms. We have shown that bacterially produced antimicrobial peptides (bacteriocins) dictate the outcome of these competitive interactions. All fully-sequenced pneumococcal strains harbor a bacteriocin-like peptide (blp) locus. The blp locus encodes for a range of diverse bacteriocins and all of the highly conserved components needed for their regulation, processing, and secretion. The diversity of the bacteriocins found in the bacteriocin immunity region (BIR) of the locus is a major contributor of pneumococcal competition. Along with the bacteriocins, immunity genes are found in the BIR and are needed to protect the producer cell from the effects of its own bacteriocin. The overlay assay is a quick method for examining a large number of strains for competitive interactions mediated by bacteriocins. The overlay assay also allows for the characterization of bacteriocin-specific immunity, and detection of secreted quorum sensing peptides. The assay is performed by pre-inoculating an agar plate with a strain to be tested for bacteriocin production followed by application of a soft agar overlay containing a strain to be tested for bacteriocin sensitivity. A zone of clearance surrounding the stab indicates that the overlay strain is sensitive to the bacteriocins produced by the pre-inoculated strain. If no zone of clearance is observed, either the overlay strain is immune to the bacteriocins being produced or the pre-inoculated strain does not produce bacteriocins. To determine if the blp locus is functional in a given strain, the overlay assay can be adapted to evaluate for peptide pheromone secretion by the pre-inoculated strain. In this case, a series of four lacZ-reporter strains with different pheromone specificity are used in the overlay.

  15. Evaluation of Tizian overlays by means of a swept source optical coherence tomography system

    Science.gov (United States)

    Marcauteanu, Corina; Sinescu, Cosmin; Negrutiu, Meda Lavinia; Stoica, Eniko Tunde; Topala, Florin; Duma, Virgil Florin; Bradu, Adrian; Podoleanu, Adrian Gh.

    2016-03-01

    The teeth affected by pathologic attrition can be restored by a minimally invasive approach, using Tizian overlays. In this study we prove the advantages of a fast swept source (SS) OCT system in the evaluation of Tizian overlays placed in an environment characterized by high occlusal forces. 12 maxillary first premolars were extracted and prepared for overlays. The Tizian overlays were subjected to 3000 alternating cycles of thermo-cycling (from -10°C to +50°C) and to mechanical occlusal overloads (at 800 N). A fast SS OCT system was used to evaluate the Tizian overlays before and after the mechanical and thermal straining. The SS (Axsun Technologies, Billerica, MA) has a central wavelength of 1060 nm, sweeping range of 106 nm (quoted at 10 dB) and a 100 kHz line rate. The depth resolution of the system, measured experimentally in air was 10 μm. The imaging system used for this study offers high spatial resolutions in both directions, transversal and longitudinal of around 10 μm, a high sensitivity, and it is also able to acquire entire tridimensional (3D)/volume reconstructions as fast as 2.5 s. Once the full dataset was acquired, rendered high resolutions en-face projections could be produced. Using them, the overlay (i.e., cement) abutment tooth interfaces were remarked both on B-scans/two-dimensional (2D) sections and in the 3D reconstructions. Using the system several open interfaces were possible to detect. The fast SS OCT system thus proves useful in the evaluation of zirconia reinforced composite overlays, placed in an environment characterized by high occlusal forces.

  16. A system to optimize mix-and-match overlay in lithography

    Science.gov (United States)

    Wakamoto, Shinji; Ishii, Yuuki; Yasukawa, Koji; Maejima, Shinroku; Kato, Atsuhiko; Robinson, John C.; Choi, Dong-Sub

    2008-03-01

    Critical processing factors in the lithography process include overlaying the pattern properly to previous layers and properly exposing the pattern to achieve the desired line width. Proper overlay can only be attained in the lithography process while the desired line width accuracy is achieved by both lithography and etch processes. Since CD is substantially influenced by etch processing, therefore, it is possible to say that overlay is one of the most important processing elements in the lithography process. To achieve the desired overlay accuracy, it is desirable to expose critical layers with the same exposure tool that exposed the previous or target layer. This need to dedicate a particular exposure tool, however, complicates the lot dispatching schedule and, even worse, decreases exposure tool utilization. In order to allow any exposure tool available to print the arriving lot, M&M (Mix and Match) overlay control becomes necessary. By reducing overlay errors in M&M control, lot dispatching scheduling will become more flexible and exposure tool utilization will improve. Since each exposure tool has a unique registration signature, high order errors appear when overlaying multiple layers exposed with different tools. Even with the same exposure tool, if a different illumination is used, a similar error will be seen. A correction scheme to make the signature differences has to be implemented, however manually characterizing each tool's signature per illumination condition is extremely tedious, and is subject human errors. The challenge is to design a system to perform the corrections automatically. In the previous paper(1), we have outlined concepts of the system scheme. The system has subsequently been developed and tested using exposure tools. In this paper test results are shown using automated distortion correction. By analyzing the results, suggestions for further improvements and further developments are shown.

  17. Faster diffraction-based overlay measurements with smaller targets using 3D gratings

    Science.gov (United States)

    Li, Jie; Kritsun, Oleg; Liu, Yongdong; Dasari, Prasad; Volkman, Catherine; Hu, Jiangtao

    2012-03-01

    Diffraction-based overlay (DBO) technologies have been developed to address the overlay metrology challenges for 22nm technology node and beyond. Most DBO technologies require specially designed targets that consist of multiple measurement pads, which consume too much space and increase measurement time. The traditional empirical approach (eDBO) using normal incidence spectroscopic reflectometry (NISR) relies on linear response of the reflectance with respect to overlay displacement within a small range. It offers convenience of quick recipe setup since there is no need to establish a model. However it requires three or four pads per direction (x or y) which adds burden to throughput and target size. Recent advances in modeling capability and computation power enabled mDBO, which allows overlay measurement with reduced number of pads, thus reducing measurement time and DBO target space. In this paper we evaluate the performance of single pad mDBO measurements using two 3D targets that have different grating shapes: squares in boxes and L-shapes in boxes. Good overlay sensitivities are observed for both targets. The correlation to programmed shifts and image-based overlay (IBO) is excellent. Despite the difference in shapes, the mDBO results are comparable for square and L-shape targets. The impact of process variations on overlay measurements is studied using a focus and exposure matrix (FEM) wafer. Although the FEM wafer has larger process variations, the correlation of mDBO results with IBO measurements is as good as the normal process wafer. We demonstrate the feasibility of single pad DBO measurements with faster throughput and smaller target size, which is particularly important in high volume manufacturing environment.

  18. Simultaneous overlay and CD measurement for double patterning: scatterometry and RCWA approach

    Science.gov (United States)

    Li, Jie; Liu, Zhuan; Rabello, Silvio; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Park, Jungchul; Singh, Lovejeet

    2009-03-01

    As optical lithography advances to 32 nm technology node and beyond, double patterning technology (DPT) has emerged as an attractive solution to circumvent the fundamental optical limitations. DPT poses unique demands on critical dimension (CD) uniformity and overlay control, making the tolerance decrease much faster than the rate at which critical dimension shrinks. This, in turn, makes metrology even more challenging. In the past, multi-pad diffractionbased overlay (DBO) using empirical approach has been shown to be an effective approach to measure overlay error associated with double patterning [1]. In this method, registration errors for double patterning were extracted from specially designed diffraction targets (three or four pads for each direction); CD variation is assumed negligible within each group of adjacent pads and not addressed in the measurement. In another paper, encouraging results were reported with a first attempt at simultaneously extracting overlay and CD parameters using scatterometry [2]. In this work, we apply scatterometry with a rigorous coupled wave analysis (RCWA) approach to characterize two double-patterning processes: litho-etch-litho-etch (LELE) and litho-freeze-litho-etch (LFLE). The advantage of performing rigorous modeling is to reduce the number of pads within each measurement target, thus reducing space requirement and improving throughput, and simultaneously extract CD and overlay information. This method measures overlay errors and CDs by fitting the optical signals with spectra calculated from a model of the targets. Good correlation is obtained between the results from this method and that of several reference techniques, including empirical multi-pad DBO, CD-SEM, and IBO. We also perform total measurement uncertainty (TMU) analysis to evaluate the overall performance. We demonstrate that scatterometry provides a promising solution to meet the challenging overlay metrology requirement in DPT.

  19. Effect of Fe content on the friction and abrasion properties of copper base overlay on steel substrate by TIG welding

    Institute of Scientific and Technical Information of China (English)

    Lü Shixiong; Song Jianling; Liu Lei; Yang Shiqin

    2009-01-01

    Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas (TIG) welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), and the friction and abrasion properties of the overlay were measured. The results show that the Fe content increases in the overlay with increasing the welding current. And with the increase of Fe content in the overlay, the friction coefficient increases and the wear mechanism changes from oxidation wear to abrasive wear and plough wear, which is related to the size and quantity of Fe grains in the overlay. While with the increase of Fe content in the overlay, the protection of oxidation layer against the oxidation wear on the melted metal decreases.

  20. Facile embedding of single vanadium atoms at the anatase TiO2(101) surface.

    Science.gov (United States)

    Koust, Stig; Arnarson, Logi; Moses, Poul G; Li, Zheshen; Beinik, Igor; Lauritsen, Jeppe V; Wendt, Stefan

    2017-04-05

    To understand the structure-reactivity relationships for mixed-metal oxide catalysts, well-defined systems are required. Mixtures of vanadia and titania (TiO2) are of particular interest for application in heterogeneous catalysis, with TiO2 often acting as the support. By utilizing high-resolution scanning tunneling microscopy, we studied the interaction of vanadium (V) with the anatase TiO2(101) surface in the sub-monolayer regime. At 80 K, metallic V nucleates into homogeneously distributed clusters onto the terraces with no preference for nucleation at the step edges. However, embedding of single V atoms into TiO2 occurs following annealing at room temperature. In conjunction with X-ray photoelectron spectroscopy data and density functional theory calculations, we propose that monomeric V atoms occupy positions of regular surface Ti sites, i.e., Ti atoms are substituted by V atoms.

  1. Research on the Impact of Amplitude of Vibrations on Electrical Parameters of Vibroarc Weld Overlay in Argon

    Directory of Open Access Journals (Sweden)

    Nikolov Mitko Ivanov

    2015-06-01

    Full Text Available The research is taken on the vibroarc welding apparatus ENTON-60 equipped with an axial non-inertial vibrator in argon shield. The criteria used for assessing the flow of the electric arc process and the formation of weld overlay clad surfaces are: short circuit voltage, voltage at the start of arc combustion, short circuit amperage, and amperage at the end of arc combustion. Wire electrode‘s vibrating frequency is considered as an input variable of the cybernetic model. It has been found that amplitude of vibrations has a significant impact on the vibroarc process - voltage parameters and welding current ratio, as the minimum amperage of short circuit and the lowest voltage at the start of arc combustion is realized at 2 mm amplitude of vibrations.

  2. Optical DC overlay measurement in the 2nd level process of 65 nm alternating phase shift mask

    Science.gov (United States)

    Ma, Jian; Han, Ke; Lee, Kyung; Korobko, Yulia; Silva, Mary; Chavez, Joas; Irvine, Brian; Henrichs, Sven; Chakravorty, Kishore; Olshausen, Robert; Chandramouli, Mahesh; Mammen, Bobby; Padmanaban, Ramaswamy

    2005-11-01

    Alternating phase shift mask (APSM) techniques help bridge the significant gap between the lithography wavelength and the patterning of minimum features, specifically, the poly line of 35 nm gate length (1x) in Intel's 65 nm technology. One of key steps in making APSM mask is to pattern to within the design tolerances the 2nd level resist so that the zero-phase apertures will be protected by the resist and the pi-phase apertures will be wide open for quartz etch. The ability to align the 2nd level to the 1st level binary pattern, i.e. the 2nd level overlay capability is very important, so is the capability of measuring the overlay accurately. Poor overlay could cause so-called the encroachment after quartz etch, producing undesired quartz bumps in the pi-apertures or quartz pits in the zero-apertures. In this paper, a simple, low-cost optical setup for the 2nd level DC (develop check) overlay measurements in the high volume manufacturing (HVM) of APSM masks is presented. By removing systematic errors in overlay associated with TIS and MIS (tool-induced shift and Mask-process induced shift), it is shown that this setup is capable of supporting the measurement of DC overlay with a tolerance as small as +/- 25 nm. The outstanding issues, such as DC overlay error component analysis, DC - FC (final check) overlay correlation and the overlay linearity (periphery vs. indie), are discussed.

  3. Desarrollo de sistemas y servicios de información sobre redes overlay peer-to-peer

    OpenAIRE

    Muñoz Gea, Juan Pedro

    2012-01-01

    [SPA] Una red overlay es una red virtual de nodos y enlaces lógicos construida sobre la red Internet. Por lo tanto, las redes overlay se pueden ver como una capa intermedia situad entre los protocolos básicos de Internet y el nivel de aplicación. Para entender por qué las redes overlay son importantes y el papel que desempeñan, merece la pena considerar las distintas razones que han motivado su aparición. En primer lugar, las redes overlay pueden utilizarse para soportar los requisitos especi...

  4. Desarrollo de sistemas y servicios de información sobre redes overlay peer-to-peer

    OpenAIRE

    Muñoz Gea, Juan Pedro

    2011-01-01

    [SPA] Una red overlay es una red virtual de nodos y enlaces lógicos construida sobre la red Internet. Por lo tanto, las redes overlay se pueden ver como una capa intermedia situad entre los protocolos básicos de Internet y el nivel de aplicación. Para entender por qué las redes overlay son importantes y el papel que desempeñan, merece la pena considerar las distintas razones que han motivado su aparición. En primer lugar, las redes overlay pueden utilizarse para soportar los requisitos especi...

  5. Agarose overlay selectively improves macrocolony formation and radiosensitivity assessment in primary fibroblasts.

    Science.gov (United States)

    Chandna, Sudhir; Dagur, Raghubendra Singh; Mathur, Ankit; Natarajan, Adayapalam Tyagarajan; Harms-Ringdahl, Mats; Haghdoost, Siamak

    2014-05-01

    Primary fibroblasts are not suitable for in vitro macrocolony assay due to their inability to form distinct colonies. Here we present a modification of agarose overlay that yielded extensive improvement in their colony formation and assessment of radiosensitivity. Macrocolony formation was assessed in primary human fibroblasts VH10 and HDFn with or without overlay using 0.5% agarose in growth medium at 24 h post-seeding. Malignant human cell lines (A549, U87) and transformed non-malignant fibroblasts (AA8 hamster, MRC5 human) were used for comparison. Agarose overlay caused significant improvement marked by early appearance (one week) of distinct colonies with high cell density and multifold higher plating efficiency than conventional macrocolony assay in VH10 and HDFn human fibroblasts. Compared to conventional assay or feeder cell supplementation, agarose overlay resulted in broader cell morphology due to improved adherence, and yielded more compact colonies. Gamma-radiation dose-response survival curves could be successfully generated for both fibroblast cell lines using this method, which yielded no such effects in the transformed/malignant cell lines tested. This easy and inexpensive 'agarose overlay technique' significantly and selectively improves the fibroblast plating efficiency, thus considerably reducing time and effort to greatly benefit the survival studies on primary fibroblasts.

  6. Design and development of a mobile image overlay system for needle interventions.

    Science.gov (United States)

    Anand, M; King, F; Ungi, T; Lasso, A; Rudan, J; Jayender, J; Fritz, J; Carrino, J A; Jolesz, F A; Fichtinger, G

    2014-01-01

    Previously, a static and adjustable image overlay systems were proposed for aiding needle interventions. The system was either fixed to a scanner or mounted over a large articulated counterbalanced arm. Certain drawbacks associated with these systems limited the clinical translation. In order to minimize these limitations, we present the mobile image overlay system with the objective of reduced system weight, smaller dimension, and increased tracking accuracy. The design study includes optimal workspace definition, selection of display device, mirror, and laser source. The laser plane alignment, phantom design, image overlay plane calibration, and system accuracy validation methods are discussed. The virtual image is generated by a tablet device and projected into the patient by using a beamsplitter mirror. The viewbox weight (1.0 kg) was reduced by 8.2 times and image overlay plane tracking precision (0.21 mm, STD = 0.05) was improved by 5 times compared to previous system. The automatic self-calibration of the image overlay plane was achieved in two simple steps and can be done away from patient table. The fiducial registration error of the physical phantom to scanned image volume registration was 1.35 mm (STD = 0.11). The reduced system weight and increased accuracy of optical tracking should enable the system to be hand held by the physician and explore the image volume over the patient for needle interventions.

  7. Implementation and benefits of advanced process control for lithography CD and overlay

    Science.gov (United States)

    Zavyalova, Lena; Fu, Chong-Cheng; Seligman, Gary S.; Tapp, Perry A.; Pol, Victor

    2003-05-01

    Due to the rapidly reduced imaging process windows and increasingly stingent device overlay requirements, sub-130 nm lithography processes are more severely impacted than ever by systamic fault. Limits on critical dimensions (CD) and overlay capability further challenge the operational effectiveness of a mix-and-match environment using multiple lithography tools, as such mode additionally consumes the available error budgets. Therefore, a focus on advanced process control (APC) methodologies is key to gaining control in the lithographic modules for critical device levels, which in turn translates to accelerated yield learning, achieving time-to-market lead, and ultimately a higher return on investment. This paper describes the implementation and unique challenges of a closed-loop CD and overlay control solution in high voume manufacturing of leading edge devices. A particular emphasis has been placed on developing a flexible APC application capable of managing a wide range of control aspects such as process and tool drifts, single and multiple lot excursions, referential overlay control, 'special lot' handling, advanced model hierarchy, and automatic model seeding. Specific integration cases, including the multiple-reticle complementary phase shift lithography process, are discussed. A continuous improvement in the overlay and CD Cpk performance as well as the rework rate has been observed through the implementation of this system, and the results are studied.

  8. Reduction of image-based ADI-to-AEI overlay inconsistency with improved algorithm

    Science.gov (United States)

    Chen, Yen-Liang; Lin, Shu-Hong; Chen, Kai-Hsiung; Ke, Chih-Ming; Gau, Tsai-Sheng

    2013-04-01

    In image-based overlay (IBO) measurement, the measurement quality of various measurement spectra can be judged by quality indicators and also the ADI-to-AEI similarity to determine the optimum light spectrum. However we found some IBO measured results showing erroneous indication of wafer expansion from the difference between the ADI and the AEI maps, even after their measurement spectra were optimized. To reduce this inconsistency, an improved image calculation algorithm is proposed in this paper. Different gray levels composed of inner- and outer-box contours are extracted to calculate their ADI overlay errors. The symmetry of intensity distribution at the thresholds dictated by a range of gray levels is used to determine the particular gray level that can minimize the ADI-to-AEI overlay inconsistency. After this improvement, the ADI is more similar to AEI with less expansion difference. The same wafer was also checked by the diffraction-based overlay (DBO) tool to verify that there is no physical wafer expansion. When there is actual wafer expansion induced by large internal stress, both the IBO and the DBO measurements indicate similar expansion results. The scanning white-light interference microscope was used to check the variation of wafer warpage during the ADI and AEI stages. It predicts a similar trend with the overlay difference map, confirming the internal stress.

  9. Diffraction-based overlay measurement on dedicated mark using rigorous modeling method

    Science.gov (United States)

    Lu, Hailiang; Wang, Fan; Zhang, Qingyun; Chen, Yonghui; Zhou, Chang

    2012-03-01

    Diffraction Based Overlay (DBO) is widely evaluated by numerous authors, results show DBO can provide better performance than Imaging Based Overlay (IBO). However, DBO has its own problems. As well known, Modeling based DBO (mDBO) faces challenges of low measurement sensitivity and crosstalk between various structure parameters, which may result in poor accuracy and precision. Meanwhile, main obstacle encountered by empirical DBO (eDBO) is that a few pads must be employed to gain sufficient information on overlay-induced diffraction signature variations, which consumes more wafer space and costs more measuring time. Also, eDBO may suffer from mark profile asymmetry caused by processes. In this paper, we propose an alternative DBO technology that employs a dedicated overlay mark and takes a rigorous modeling approach. This technology needs only two or three pads for each direction, which is economic and time saving. While overlay measurement error induced by mark profile asymmetry being reduced, this technology is expected to be as accurate and precise as scatterometry technologies.

  10. Residual stress determination in a dissimilar weld overlay pipe by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Wanchuck, E-mail: chuckwoo@kaeri.re.kr [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Em, Vyacheslav [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Hubbard, Camden R. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Lee, Ho-Jin [Nuclear Materials Research Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Park, Kwang Soo [Corporate R and D Institute, Doosan Heavy Industries and Construction, Changwon 641-792 (Korea, Republic of)

    2011-10-15

    Highlights: {yields} Determined residual stress distribution in a dissimilar weld overlay pipe. {yields} Consists of a ferritic (SA508), austenitic (F316L) steels, Alloy 182 consumable. {yields} Measured significant compression (-600 MPa) near the inner wall of overlay. {yields} Validate integrity of the inner wall for the pressurized nozzle nuclear structure. - Abstract: Residual stresses were determined through the thickness of a dissimilar weld overlay pipe using neutron diffraction. The specimen has a complex joining structure consisting of a ferritic steel (SA508), austenitic steel (F316L), Ni-based consumable (Alloy 182), and overlay of Ni-base superalloy (Alloy 52M). It simulates pressurized nozzle components, which have been a critical issue under the severe crack condition of nuclear power reactors. Two neutron diffractometers with different spatial resolutions have been utilized on the identical specimen for comparison. The macroscopic 'stress-free' lattice spacing (d{sub o}) was also obtained from both using a 2-mm width comb-like coupon. The results show significant changes in residual stresses from tension (300-400 MPa) to compression (-600 MPa) through the thickness of the dissimilar weld overlay pipe specimen.

  11. A Measurement Study of the Structured Overlay Network in P2P File-Sharing Systems

    Directory of Open Access Journals (Sweden)

    Mo Zhou

    2007-01-01

    Full Text Available The architecture of P2P file-sharing applications has been developing to meet the needs of large scale demands. The structured overlay network, also known as DHT, has been used in these applications to improve the scalability, and robustness of the system, and to make it free from single-point failure. We believe that the measurement study of the overlay network used in the real file-sharing P2P systems can provide guidance for the designing of such systems, and improve the performance of the system. In this paper, we perform the measurement in two different aspects. First, a modified client is designed to provide view to the overlay network from a single-user vision. Second, the instances of crawler programs deployed in many nodes managed to crawl the user information of the overlay network as much as possible. We also find a vulnerability in the overlay network, combined with the character of the DNS service, a more serious DDoS attack can be launched.

  12. Overlay control methodology comparison: field-by-field and high-order methods

    Science.gov (United States)

    Huang, Chun-Yen; Chiu, Chui-Fu; Wu, Wen-Bin; Shih, Chiang-Lin; Huang, Chin-Chou Kevin; Huang, Healthy; Choi, DongSub; Pierson, Bill; Robinson, John C.

    2012-03-01

    Overlay control in advanced integrated circuit (IC) manufacturing is becoming one of the leading lithographic challenges in the 3x and 2x nm process nodes. Production overlay control can no longer meet the stringent emerging requirements based on linear composite wafer and field models with sampling of 10 to 20 fields and 4 to 5 sites per field, which was the industry standard for many years. Methods that have emerged include overlay metrology in many or all fields, including the high order field model method called high order control (HOC), and field by field control (FxFc) methods also called correction per exposure. The HOC and FxFc methods were initially introduced as relatively infrequent scanner qualification activities meant to supplement linear production schemes. More recently, however, it is clear that production control is also requiring intense sampling, similar high order and FxFc methods. The added control benefits of high order and FxFc overlay methods need to be balanced with the increased metrology requirements, however, without putting material at risk. Of critical importance is the proper control of edge fields, which requires intensive sampling in order to minimize signatures. In this study we compare various methods of overlay control including the performance levels that can be achieved.

  13. Image-based overlay (IBO) target segment design on self-aligned patterning process

    Science.gov (United States)

    Ye, Lei; Hu, Huayong; He, Weiming

    2016-03-01

    Self-Aligned Double Patterning (SADP) is widely applied in advanced sub-4X patterning technology, especially for the 1D resolution shrinkage of memory technology. As the application of SADP makes lithography minimum pitch down to half of design pitch with the remaining spacer aside core, its alignment mark and overlay (OVL) mark have to be well-segmented to ensure enough mark contrast. In this paper, we designed two types of image-based overlay (IBO) bar in bar (BIB) OVL target: bar-segmentation and background-segmentation with different duty ratio. Based on these two designed types of marks, we focus on the OVL of 2nd photo layer to 1st SADP layer with the core removed (which means spacer grating structure remained). We studied the effect of the overlay target segmentation on the precision and robustness of wafer-level overlay performance. Different lithography processes were also studied, including single layer lithography and tri-layer lithography with planarized spacer grating structures. We found there are strong correlations between overlay measurement accuracy and background segmentation rules. The results of our study will be presented and discussed in this paper.

  14. The challenges of transitioning from linear to high-order overlay control in advanced lithography

    Science.gov (United States)

    Adel, M.; Izikson, P.; Tien, D.; Huang, C. K.; Robinson, J. C.; Eichelberger, B.

    2008-03-01

    In the lithography section of the ITRS 2006 update, at the top of the list of difficult challenges appears the text "overlay of multiple exposures including mask image placement". This is a reflection of the fact that today overlay is becoming a major yield risk factor in semiconductor manufacturing. Historically, lithographers have achieved sufficient alignment accuracy and hence layer to layer overlay control by relying on models which define overlay as a linear function of the field and wafer coordinates. These linear terms were easily translated to correctibles in the available exposure tool degrees of freedom on the wafer and reticle stages. However, as the 45 nm half pitch node reaches production, exposure tool vendors have begun to make available, and lithographers have begun to utilize so called high order wafer and field control, in which either look up table or high order polynomial models are modified on a product by product basis. In this paper, the major challenges of this transition will be described. It will include characterization of the sources of variation which need to be controlled by these new models and the overlay and alignment sampling optimization problem which needs to be addressed, while maintaining the ever tightening demands on productivity and cost of ownership.

  15. Information Exchange rather than Topology Awareness: Cooperation between P2P Overlay and Traffic Engineering

    Directory of Open Access Journals (Sweden)

    Jia Zhao

    2014-01-01

    Full Text Available Solutions to the routing strategic conflict between noncooperative P2P overlay and ISP underlay go separate ways: hyperselfishness and cooperation. Unpredictable (possibly adverse impact of the hyperselfish topology awareness, which is adopted in both overlay routing and traffic engineering, has not been sufficiently studied in the literature. Topology-related information exchange in a cooperatively efficient way should be highlighted to alleviate the cross-layer conflict. In this paper, we first illustrate the hyperselfish weakness with two dynamic noncooperative game models in which hyperselfish overlay or underlay has to accept a suboptimal profit. Then we build a synergistic cost-saving (SC game model to reduce the negative effects of noncooperation. In the SC model, through information exchange, that is, the classified path-delay metrics for P2P overlay and peer locations for underlay, P2P overlay selects proximity as well as saving traffic transit cost for underlay, and ISP underlay adjusts routing to optimize network cost as well as indicating short delay paths for P2P. Simulations based on the real and generated topologies validate cost improvement by SC model and find a proper remote threshold value to limit P2P traffic from remote area, cross-AS, or cross-ISP.

  16. Investigation on synchronization of the offset printing process for fine patterning and precision overlay

    Science.gov (United States)

    Kang, Dongwoo; Lee, Eonseok; Kim, Hyunchang; Choi, Young-Man; Lee, Seunghyun; Kim, Inyoung; Yoon, Dukkyun; Jo, Jeongdai; Kim, Bongmin; Lee, Taik-Min

    2014-06-01

    Offset printing processes are promising candidates for producing printed electronics due to their capacity for fine patterning and suitability for mass production. To print high-resolution patterns with good overlay using offset printing, the velocities of two contact surfaces, which ink is transferred between, should be synchronized perfectly. However, an exact velocity of the contact surfaces is unknown due to several imperfections, including tolerances, blanket swelling, and velocity ripple, which prevents the system from being operated in the synchronized condition. In this paper, a novel method of measurement based on the sticking model of friction force was proposed to determine the best synchronized condition, i.e., the condition in which the rate of synchronization error is minimized. It was verified by experiment that the friction force can accurately represent the rate of synchronization error. Based on the measurement results of the synchronization error, the allowable margin of synchronization error when printing high-resolution patterns was investigated experimentally using reverse offset printing. There is a region where the patterning performance is unchanged even though the synchronization error is varied, and this may be viewed as indirect evidence that printability performance is secured when there is no slip at the contact interface. To understand what happens at the contact surfaces during ink transfer, the deformation model of the blanket's surface was developed. The model estimates how much deformation on the blanket's surface can be borne by the synchronization error when there is no slip at the contact interface. In addition, the model shows that the synchronization error results in scale variation in the machine direction (MD), which means that the printing registration in the MD can be adjusted actively by controlling the synchronization if there is a sufficient margin of synchronization error to guarantee printability. The effect of

  17. Specification guidelines for surface preparation of concrete prior to repair

    OpenAIRE

    Courard, Luc; Bissonnette, Benoît; Garbacz, Andrzej

    2017-01-01

    The repair of concrete requests specific preparation operations needed for guaranteeing compatibility between substrate and new materials as well as the development of adhesion properties. These specification guidelines contain design and construction recommendations for surface preparation of concrete for repair and overlay. The paper summarizes current knowledge, best practices and results of the research concerning the surface preparation of concrete prior to application of repair/overlay ...

  18. 基于SDN架构的Overlay VPN技术研究

    Institute of Scientific and Technical Information of China (English)

    张鹏; 孙琼

    2016-01-01

    首先介绍基于SDN架构的Overlay VPN技术,能为中小企业提供低成本、高性能、易使用、安全的VPN服务.Overlay VPN预先在网络中部署中间转发节点vPE,集中式控制器通过智能选路算法,为用户提供有保障的VPN服务.此外,分析Overlay VPN的架构、控制平面和数据平面的流程,并提出若干优化的方向.

  19. Maxillary overlay removable partial dentures for the restoration of worn teeth.

    Science.gov (United States)

    Fonseca, Júlio; Nicolau, Pedro; Daher, Tony

    2011-04-01

    Prolonged tooth maintenance by a more aged population considerably increases the probability of dentists having to treat patients with high levels of tooth wear. Pathological tooth wear, caused primarily by parafunction, seems to be a growing problem that affects a large number of adult patients. The clinical report presents a case of a partially edentulous patient with an elevated degree of wear in the upper jaw caused by attrition and erosion, rehabilitated with a maxillary overlay removable partial denture (ORPD) consisting of a chrome-cobalt (Cr-Co) framework with anterior acrylic resin veneers, posterior cast overlays, and acrylic resin denture bases. Removable partial prosthesis is a treatment alternative when teeth are found to be severely worn or when the patient needs a simple and economical option. Because economics is a conditional factor of the treatment, the clinician should present different treatment alternatives to the patient, in which the overlay prosthesis can be considered.

  20. An Efficient Method for Performance Evaluation of Femto-Macro Overlay Systems

    DEFF Research Database (Denmark)

    Huang, Yue-Cai; Ko, King-Tim; Huang, Qian

    2011-01-01

    This paper considers a two-tier femto-macro overlay network architecture, where groups of femtocells are overlaid by macrocells. The capacity of the femtocells is limited, thus redirection of blocked femto calls to the overlaid macrocell is used as a QoS assurance strategy. Similar overflow...... approaches have been used in telephony; however, extension of this approach to capacity-constrained femto-macro overlay networks poses significant challenges due to the wide variety of bandwidth requirement of Internet services, the large number of femtocells overlaid by a macrocell, and the need for fast...... computations imposed by practical requirements of dynamic real-time resource allocation. We propose a new computationally efficient numerical method for the loss probability approximation in such two-tier femto-macro overlay networks. The accuracy of the method is verified by exact Markov-chain solutions...

  1. Analysis of an Orthotropic Deck Stiffened with a Cement-Based Overlay

    DEFF Research Database (Denmark)

    Walter, Rasmus; Olesen, John Forbes; Stang, Henrik

    2007-01-01

    Over the past years, with increasing traffic volumes and higher wheel loads, fatigue damage in steel parts of typical orthotropic steel bridge decks has been experienced on heavily trafficked routes. A demand exists to find a durable system to increase the fatigue safety of orthotropic steel bridge...... decks. A solution might be to enhance the stiffness of the traditional orthotropic bridge deck by using a cement-based overlay. In this paper, an orthotropic steel bridge deck stiffened with a cement-based overlay is analyzed. The analysis is based on nonlinear fracture mechanics, and utilizes...... of crack widths. Furthermore, the analysis shows that debonding is initiated for a certain crack width in the overlay. The load level where cracking and debonding is initiated depends on the stress-crack opening relationship of the material....

  2. Mn3{ital s} multiplet splitting of pseudomorphic Mn overlayers on Ru(001)

    Energy Technology Data Exchange (ETDEWEB)

    Sham, T.K. [Department of Chemistry, The University of Western Ontario, London N6A 5B7 (Canada); Shek, M.L. [National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States); Hrbek, J.; Campen, D.G. [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    1996-07-01

    The Mn3{ital s} multiplet splitting for a series of Mn overlayers on Ru(001) has been measured with synchrotron radiation photoemission spectroscopy. These overlayers were prepared by vapor deposition of Mn onto a Ru(001) substrate at a monolayer/minute dosing rate at room temperature. Under these conditions, the Mn overlayers grow pseudomorphically to multilayer coverages. It is found that this system exhibits a noticeable increase in the Mn3{ital s} multiplet splitting and a positive binding energy shift as the coverage increases from monolayer to multilayer (12 ML). These results are attributed to the increase in the atomic volume, and hence the local magnetic moment at the Mn site on the average, with increasing coverage. {copyright} {ital 1996 American Vacuum Society}

  3. Streaming Media over a Color Overlay Based on Forward Error Correction Technique

    Institute of Scientific and Technical Information of China (English)

    张晓瑜; 沈国斌; 李世鹏; 钟玉琢

    2004-01-01

    The number of clients that receive high-quality streaming video from a source is greatly limited by the application requirements,such as the high bandwidth and reliability.In this work,a method was developed to construct a color overlay,which enables clients to receive data across multiple paths,based on the forward error correction technique.The color overlay enlarges system capacity by reducing the bottlenecks and extending the bandwidth,improves reliability against node failure,and is more resilient to fluctuations of network metrics.A light-weight protocol for building the overlay is also presented.Extensive simulations were conducted and the results clearly support the claimed advantages.

  4. Welding overlay analysis of dissimilar metal weld cracking of feedwater nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Y.L., E-mail: YLTsai@itri.org.t [National Chiao Tung University, Mechanical Engineering Department, 1001 TaHsueh Road, HsinChu, Taiwan 30010 (China); Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Wang, Li. H. [Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Fan, T.W. [Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Chung Hua University, Department of Civil Engineering and Engineering Informatics, 707, Sec.2, WuFu Rd., HsinChu, Taiwan 300 (China); Ranganath, Sam [Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Wang, C.K. [Taiwan Power Company (TPC), No.242, Sec. 3, Roosevelt Rd., Zhongzheng District, Taipei City 100, Taiwan (China); Chou, C.P. [National Chiao Tung University, Mechanical Engineering Department, 1001 TaHsueh Road, HsinChu, Taiwan 30010 (China)

    2010-01-15

    Inspection of the weld between the feedwater nozzle and the safe end at one Taiwan BWR showed axial indications in the Alloy 182 weld. The indication was sufficiently deep that continued operation could not be justified considering the crack growth for one cycle. A weld overlay was decided to implement for restoring the structural margin. This study reviews the cracking cases of feedwater nozzle welds in other nuclear plants, and reports the lesson learned in the engineering project of this weld overlay repair. The overlay design, the FCG calculation and the stress analysis by FEM are presented to confirm that the Code Case structural margins are met. The evaluations of the effect of weld shrinkage on the attached feedwater piping are also included. A number of challenges encountered in the engineering and analysis period are proposed for future study.

  5. On the Degree Distribution of Faulty Peer-to-Peer Overlays

    CERN Document Server

    Ferretti, Stefano

    2011-01-01

    This paper presents an analytical framework to model fault-tolerance in unstructured peer-to-peer overlays, represented as complex networks. We define a distributed protocol peers execute for managing the overlay and reacting to node faults. Based on the protocol, evolution equations are defined and manipulated by resorting to generating functions. Obtained outcomes provide insights on the nodes' degree probability distribution. From the study of the degree distribution, it is possible to estimate other important metrics of the peer-to-peer overlay, such as the diameter of the network. We study different networks, characterized by three specific desired degree distributions, i.e. nets with nodes having a fixed desired degree, random graphs and scale-free networks. All these networks are assessed via the analytical tool and simulation as well. Results show that the approach can be factually employed to dynamically tune the average attachment rate at peers so that they maintain their own desired degree and, in ...

  6. Refractometric sensor utilizing a vertically coupled polymeric microdisk resonator incorporating a high refractive index overlay.

    Science.gov (United States)

    Kim, Gun-Duk; Son, Geun-Sik; Lee, Hak-Soon; Kim, Ki-Do; Lee, Sang-Shin

    2009-04-01

    A refractometric sensor resorting to a vertically coupled polymeric microdisk resonator was demonstrated, estimating the refractive index (RI) of an analyte by monitoring the resonant wavelength shift in its transfer characteristics. The disk resonator was especially overlaid with a high RI TiO2 film, thereby reinforcing the interaction of the evanescent field of its guided mode with the analyte. The sensitivity of the sensor was theoretically and experimentally confirmed to be enhanced by adjusting the overlay thickness. The fabricated sensor provided the maximum sensitivity of approximately 294 nm/RIU (refractive index unit) with the 40-nm-thick overlay, which is equivalent to an improvement of 150% compared with the case without the overlay.

  7. Topology-aware peer-to-peer overlay network for Ad-hoc

    Institute of Scientific and Technical Information of China (English)

    WANG Shi-guo; JI Hong; LI Ting; MEI Jing-qing

    2009-01-01

    The mismatch between the structured peer-to-peer (P2P) overlay network, which is based on Hashing, and the actual physical network, leads to query repeatedly passing through some nodes in the actual route when it is applied in Ad-hoc networks. An approach of getting an appropriate node identifier (ID) bearing its local physical information is proposed, in which the traditional theory of getting node ID through Hashing the node's Internet protocol (IP) address is abandoned, and a topology-aware overlay network suiting Ad-hoc networks is constructed. The simulation results show that the overlay network constructed in the proposed method can avoid the route being iteratively accessed. Meanwhile, it can effectively minimize the latency and improve the load balance.

  8. Intermittent-contact scanning capacitance microscopy imaging and modeling for overlay metrology

    Science.gov (United States)

    Mayo, S.; Kopanski, J. J.; Guthrie, W. F.

    1998-11-01

    Overlay measurements of the relative alignment between sequential layers are one of the most critical issues for integrated circuit (IC) lithography. We have implemented on an AFM platform a new intermittent-contact scanning capacitance microscopy (IC-SCM) mode that is sensitive to the tip proximity to an IC interconnect, thus making it possible to image conductive structures buried under planarized dielectric layers. Such measurements can be used to measure IC metal-to-resist lithography overlay. The AFM conductive cantilever probe oscillating in a vertical plane was driven at frequency ω, below resonance. By measuring the tip-to-sample capacitance, the SCM signal is obtained as the difference in capacitance, ΔC(ω), at the amplitude extremes. Imaging of metallization structures was obtained with a bars-in-bars aluminum structure embedded in a planarized dielectric layer 1 μm thick. We have also modeled, with a two-dimensional (2D) electrostatic field simulator, IC-SCM overlay data of a metallization structure buried under a planarized dielectric having a patterned photoresist layer deposited on it. This structure, which simulates the metal-to-resist overlay between sequential IC levels, allows characterization of the technique sensitivity. The capacitance profile across identical size electrically isolated or grounded metal lines embedded in a dielectric was shown to be different. The floating line shows capacitance enhancement at the line edges, with a minimum at the line center. The grounded line shows a single capacitance maximum located at the line center, with no edge enhancement. For identical line dimensions, the capacitance is significantly larger for grounded lines making them easier to image. A nonlinear regression algorithm was developed to extract line center and overlay parameters with approximately 3 nm resolution at the 95% confidence level, showing the potential of this technique for sub-micrometer critical dimension metrology. Symmetric test

  9. A New Approach to Assess the Positional Accuracy of Maps Generated by GIS Overlay Operations

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper proposes a new approach to assess the positional accuracy of maps generated by overlaying multi-scale spatial data layers with different levels of positional accuracy.The existing techniques for assessing the positional accuracy of point,line and polygon features is first examined.Then a taxonomy of graphic features on the derived maps is developed by analyzing the specific processes of overlay operations.Finally,a detailed description of the new approach is provided and the implementation of this new method in practical applications is described.

  10. Studying protein-protein interactions via blot overlay/far western blot.

    Science.gov (United States)

    Hall, Randy A

    2015-01-01

    Blot overlay is a useful method for studying protein-protein interactions. This technique involves fractionating proteins on SDS-PAGE, blotting to nitrocellulose or PVDF membrane, and then incubating with a probe of interest. The probe is typically a protein that is radiolabeled, biotinylated, or simply visualized with a specific antibody. When the probe is visualized via antibody detection, this technique is often referred to as "Far Western blot." Many different kinds of protein-protein interactions can be studied via blot overlay, and the method is applicable to screens for unknown protein-protein interactions as well as to the detailed characterization of known interactions.

  11. A study on outcome of underlay, overlay and combined techniques of myringoplasty.

    Science.gov (United States)

    Sengupta, Arunabha; Basak, Bijan; Ghosh, Debasish; Basu, Deepjoy; Adhikari, Debasish; Maity, Kuntal

    2012-03-01

    Myringoplasty is a procedure which deals on repair of the tympanic membrane. This procedure can be done via postaural, endaural or endomeatal route. Various grafts such as temporalis fascia, vein graft, perichondrium are used. The technique can be categorized as underlay, overlay, interlay or its combination depending on the placement of the graft material. This study was done to compare underlay, overlay and combined technique in terms of the closure of the membrane defect, postoperative complications and over all success rates. Apart from few complications, this study revealed over all success rate was best with combined technique but the difference was not significant statistically when the methods are comparable among them.

  12. Detection of overlay error in double patterning gratings using phase-structured illumination.

    Science.gov (United States)

    Peterhänsel, Sandy; Gödecke, Maria Laura; Paz, Valeriano Ferreras; Frenner, Karsten; Osten, Wolfgang

    2015-09-21

    With the help of simulations we study the benefits of using coherent, phase-structured illumination to detect the overlay error in resist gratings fabricated by double patterning. Evaluating the intensity and phase distribution along the focused spot of a high numerical aperture microscope, the capability of detecting magnitude and direction of overlay errors in the range of a few nanometers is investigated for a wide range of gratings. Furthermore, two measurement approaches are presented and tested for their reliability in the presence of white Gaussian noise.

  13. Kenny-Caffey Syndrome: oral findings and 4-year follow-up of overlay denture therapy.

    Science.gov (United States)

    Demir, Tahsin; Kecik, Defne; Cehreli, Zafer C

    2007-01-01

    Kenny-Caffey Syndrome (KCS) is an extremely rare osteosclerotic bone dysplasia associated with hypocalcemia and ocular abnormalities. Although the condition is well reported in the medical literature, dental manifestations have not been discussed in great detail. The purpose of this report is to present specific oral features and prosthetic management in a KCS patient. Overlay dentures were utilized in the management of low vertical dimension of occlusion, congenital absence of several permanent teeth, and problems associated with function and esthetics. Results of the 4-year follow-up overlay denture therapy are presented.

  14. Development of Weld Overlay Technology for Dissimilar Welds in Pressurizer Nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Park, K. S.; Byeon, J. G.; Lee, J. B. [Doosan Heavy Industries and Construction Co., Daejeon (Korea, Republic of)

    2009-10-15

    As a result of Primary Water Stress Corrosion Cracking (PWSCC) in alloy 600, leaks in dissimilar metal welds of pressurizer nozzles were discovered recently in several US plants. The involved companies developed advanced repair techniques to prevent or repair PWSCC applying weld overlay procedures to dissimilar metal welds such as those between pipes and nozzles. Within 2 or 3 years, more than half of the nuclear power plants in Korea will have been in operation for more than 20 years. From this background, a weld overlay procedure has been developed in Korea for the dissimilar metal welds of pressurizer nozzles.

  15. Impact of reticle writing errors on the on-product overlay performance

    Science.gov (United States)

    van Haren, Richard; Cekli, Hakki Ergun; Liu, Xing Lan; Beltman, Jan; Pastol, Anne; Massin, Jean; Dupre La Tour, Emilie; Gatefait, Maxime; Sundermann, Frank

    2014-10-01

    The on-product overlay specification and Advanced Process Control (APC) are getting extremely challenging particularly after the introduction of multi-patterning applications like Litho-Etch-Litho-Etch (LELE). While the Reticle Writing Error (RWE) contribution could be marginalized for quite some time in the layer-to-layer overlay budget, it will become one of the dominating overlay contributors when the intra-layer overlay budget is considered. While most of the overlay contributors like wafer processing, scanner status, reticle transmission, dose, illumination conditions drop out of the intra-layer overlay budget, this is certainly not the case for reticle to reticle writing differences. In this work, we have studied the impact of the RWE on the on-product overlay performance. We show that the RWE can be characterized by an off-line mask registration tool and the modelled results can be sent as feed-forward corrections to the ASML TWINSCANTM. By doing so, the overlay control complexity (e.g. send-ahead wafers, APC settling time) can be reduced significantly. Off-line characterization enables that all reticles virtually become equal after correction (at least to the level of correction capability of the scanner). This means that all higher order RWE contributions (currently up to a third order polynomial) can be removed from the fingerprint. We show that out of 50 production reticles (FEOL, 28-nm technology), 30% can be improved on residual level when non-linear feed-forward corrections are considered as well. The additional benefit of feeding forward linear corrections to the scanner is even higher: it is anticipated that a large portion of the APC variation might find its origin in the RWE contribution. In order to send feed-forward corrections to the scanner, we obviously rely on the quality of the off-line RWE measurements. These measurements are usually provided by a registration tool at the mask shop. To secure the quality, an independent experimental

  16. Super-proximity routing in structured peer-to-peer overlay networks

    Institute of Scientific and Technical Information of China (English)

    WU Zeng-de(吴增德); RAO Wei-xiong(饶卫雄); MA Fan-yuan(马范援)

    2004-01-01

    Peer-to-Peer systems are emerging as one of the most popular Internet applications. Structured Peer-to-Peer overlay networks use identifier based routing algorithms to allow robustness, load balancing, and distributed lookup needed in this environment. However, identifier based routing that is independent of Internet topology tends to be of low efficiency. Aimed at improving the routing efficiency, the super-proximity routing algorithms presented in this paper combine Internet topology and overlay routing table in choosing the next hop. Experimental results showed that the algorithms greatly improve the efficiency of Peer-to-Peer routing.

  17. Digital reconstructed radiography with multiple color image overlay for image-guided radiotherapy.

    Science.gov (United States)

    Yoshino, Shinichi; Miki, Kentaro; Sakata, Kozo; Nakayama, Yuko; Shibayama, Kouichi; Mori, Shinichiro

    2015-05-01

    Registration of patient anatomical structures to the reference position is a basic part of the patient set-up procedure. Registration of anatomical structures between the site of beam entrance on the patient surface and the distal target position is particularly important. Here, to improve patient positional accuracy during set-up for particle beam treatment, we propose a new visualization methodology using digitally reconstructed radiographs (DRRs), overlaid DRRs, and evaluation of overlaid DRR images in clinical cases. The overlaid method overlays two DRR images in different colors by dividing the CT image into two CT sections at the distal edge of the target along the treatment beam direction. Since our hospital uses fixed beam ports, the treatment beam angles for this study were set at 0 and 90 degrees. The DRR calculation direction was from the X-ray tube to the imaging device, and set to 180/270 degrees and 135/225 degrees, based on the installation of our X-ray imaging system. Original and overlaid DRRs were calculated using CT data for two patients, one with a parotid gland tumor and the other with prostate cancer. The original and overlaid DRR images were compared. Since the overlaid DRR image was completely separated into two regions when the DRR calculation angle was the same as the treatment beam angle, the overlaid DRR visualization technique was able to provide rich information for aiding recognition of the relationship between anatomical structures and the target position. This method will also be useful in patient set-up procedures for fixed irradiation ports.

  18. The asphalt overlay Engineering construction control points%沥青罩面工程施工控制要点

    Institute of Scientific and Technical Information of China (English)

    朱新春

    2012-01-01

      沥青罩面是近年来发展起来的一种路面养护新技术,所谓沥青罩面就是以一定级配的碎石作为骨料,以沥青作为结合料,利用专业机械或人工撒铺均匀,经过压实后在路面上形成的表面处治层。多年的实践证明,沥青罩面具有良好的使用性能,不仅可以周期性地恢复原路面被磨耗的厚度,还可以处理路面的一般性破损,改善路面的抗滑能力和平整度,尤其在封闭路面龟网裂、防水抗滑、改善路容和增强耐磨性等方面,效果十分良好。此外,它还具有质量好、进度快、成本低、工序简单、开放交通早等显著优点。在这项技术的推广应用方面,我们不断总结经验,努力探讨提高质量、降低成本的方法,使这一技术在公路养护中充分发挥了作用,现就沥青罩面的施工控制谈几点体会。%  A road asphalt overlay is developed in recent years the conservation of new technologies, the so-called asphalt overlay is to a certain level with gravel as aggregate in asphalt as the binder, the use of the professional machinery or artificial Caesar Shop uniform, after Treatment on the road surface formed after compaction layer. Years of practice proved asphalt overlay has good performance, not only periodically restore the original road wear thickness can also handle the general road damage, improve the skid resistance of the road surface and flatness, especially in a closed road turtle net crack, waterproof skid, improve road capacity and enhanced wear resistance, the effect is very good. In addition, it has a good quality, fast progress, low-cost, simple process, open to traffic as early as other notable advantages. Promote the application of this technology, we are con-stantly sum up experience, efforts to explore methods to improve quality, lower costs, making this technology to give full play to the role of road maintenance, construction of the asphalt

  19. Overlaying Design of Lianguang Road Old Asphalt Pavement%联广路旧沥青路面加铺设计

    Institute of Scientific and Technical Information of China (English)

    陈燕飞

    2013-01-01

    Through the Lianguang road pavement reconstruction project, this paper introduced the assessment of asphalt pavement surface distress situation and proposed the different overlaying designs for different road damage situation.%  通过联广路路面改造项目,介绍沥青路面破损状况分析评定,针对不同的路面破损情况提出不同的旧路加铺设计方案。

  20. Interactive overlay maps for US Patent (USPTO) data based on International Patent Classifications (IPC)

    NARCIS (Netherlands)

    L. Leydesdorff; D. Kushnir; I. Rafols

    2014-01-01

    We report on the development of an interface to the US Patent and Trademark Office (USPTO) that allows for the mapping of patent portfolios as overlays to basemaps constructed from citation relations among all patents contained in this database during the period 1976-2011. Both the interface and the

  1. Frenkel-Kontorova Model of the Dimerized Overlayer System with Vacancies

    Institute of Scientific and Technical Information of China (English)

    XU Hai-Bo; WANG Guang-Rui; CHEN Shi-Gang

    2000-01-01

    The reconstruction of the dimerized overlayer system with vacancies is studied via a diatomic chain Frenkel Kontorova model. We present the details of the exactly solvable model and the analytical solution of the atomic displacements in the ground state. Our calculations explain the 2 × N reconstruction observed in Ge/Si(100) and Ga/Si(112).

  2. Colored Overlays Enhance Visual Perceptual Performance in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Ludlow, A. K.; Wilkins, A. J.; Heaton, P.

    2008-01-01

    Children with autism spectrum disorders (ASD), together with controls matched for age and ability participated in three experiments that assessed the therapeutic benefit of colored overlays. The findings from the first experiment showed that a significantly greater proportion of children with ASD, than controls, increased reading speed when using…

  3. Assessing the Crossdisciplinarity of Technology-Enhanced Learning with Science Overlay Maps and Diversity Measures

    Science.gov (United States)

    Kalz, Marco; Specht, Marcus

    2014-01-01

    This paper deals with the assessment of the crossdisciplinarity of technology-enhanced learning (TEL). Based on a general discussion of the concept interdisciplinarity and a summary of the discussion in the field, two empirical methods from scientometrics are introduced and applied. Science overlay maps and the Rao-Stirling diversity index are…

  4. Improved Intelligent Underlay-Overlay Combined with Frequency Hopping in GSM

    DEFF Research Database (Denmark)

    Wigard, Jeroen; Nielsen, Thomas Toftegaard; Mogensen, Preben Elgaard

    1997-01-01

    IUO (intelligent underlay-overlay) in a combination with random frequency hopping in GSM is analysed. Several improvements to the original IUO concept analysed in Nielsen et al. (1997) are introduced. With the improved IUO concept it is possible to load a network configuration consisting of 4 reg...

  5. Colored Overlays Enhance Visual Perceptual Performance in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Ludlow, A. K.; Wilkins, A. J.; Heaton, P.

    2008-01-01

    Children with autism spectrum disorders (ASD), together with controls matched for age and ability participated in three experiments that assessed the therapeutic benefit of colored overlays. The findings from the first experiment showed that a significantly greater proportion of children with ASD, than controls, increased reading speed when using…

  6. Posterior open occlusion management by registration of overlay removable partial denture: A clinical report

    Directory of Open Access Journals (Sweden)

    Saeid Nosouhian

    2015-01-01

    Full Text Available This clinical report describes prosthetic rehabilitation of posterior open bite relationship in a patient with several missing teeth and skeletal Class III malocclusion. Primary diagnostic esthetic evaluations were performed by mounting casts in centric relation and estimating lost vertical dimension of occlusion. Exclusive treatments were designated by applying overlay removable partial denture with external attachment systems for higher retentions.

  7. Posterior open occlusion management by registration of overlay removable partial denture: A clinical report.

    Science.gov (United States)

    Nosouhian, Saeid; Davoudi, Amin; Derhami, Mohammad

    2015-01-01

    This clinical report describes prosthetic rehabilitation of posterior open bite relationship in a patient with several missing teeth and skeletal Class III malocclusion. Primary diagnostic esthetic evaluations were performed by mounting casts in centric relation and estimating lost vertical dimension of occlusion. Exclusive treatments were designated by applying overlay removable partial denture with external attachment systems for higher retentions.

  8. Assessing the Crossdisciplinarity of Technology-Enhanced Learning with Science Overlay Maps and Diversity Measures

    Science.gov (United States)

    Kalz, Marco; Specht, Marcus

    2014-01-01

    This paper deals with the assessment of the crossdisciplinarity of technology-enhanced learning (TEL). Based on a general discussion of the concept interdisciplinarity and a summary of the discussion in the field, two empirical methods from scientometrics are introduced and applied. Science overlay maps and the Rao-Stirling diversity index are…

  9. Science overlay maps: a new tool for research policy and library management

    NARCIS (Netherlands)

    Rafols, I.; Porter, A.L.; Leydesdorff, L.

    2010-01-01

    We present a novel approach to visually locate bodies of research within the sciences, both at each moment of time and dynamically. This article describes how this approach fits with other efforts to locally and globally map scientific outputs. We then show how these science overlay maps help

  10. Field Investigation of Various Weld Overlays in a Waste Incineration Plant

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Larsen, O. H.

    2005-01-01

    which was present in every test panel. It was observed that all the weld overlay test sections behaved similar to machined alloy 625 in that there was general corrosion and pitting corrosion. In addition, alloy 622 also exhibited preferential corrosion with respect to its dendrite structure....

  11. Overlay versus underlay myringoplasty: report of outcomes considering closure of perforation and hearing function.

    Science.gov (United States)

    Sergi, B; Galli, J; De Corso, E; Parrilla, C; Paludetti, G

    2011-12-01

    In this series of patients, the underlay or overlay positioning of a graft achieves successful outcome for both repair of perforation and hearing function, with better hearing gain in the underlay group. In myringoplasty, the two most common techniques for positioning the graft relative to the remnant of both the tympanic membrane and the annulus are the "overlay" and the "underlay" techniques. 115 patients who underwent myringoplasty for tympanic membrane perforation secondary to chronic otitis media and/or trauma were included, and hearing function was evaluated. We prefer an overlay technique in subtotal perforations, in those involving the anterior and antero-inferior parts of the ear drum with respect to the handle of the malleus and in revision surgery. We reserve an underlay technique for smaller perforations and for those limited to the posterior part of the tympanic membrane. Of 115 cases, 63 underwent an overlay myringoplasty and 52 underlay myringoplasty. In the former group, five cases were anatomically unsuccessful, whereas in the second group there were three failures. The air bone gap improved significantly in both groups with a better hearing gain in the underlay group.

  12. Science overlay maps: a new tool for research policy and library management

    NARCIS (Netherlands)

    Rafols, I.; Porter, A.L.; Leydesdorff, L.

    2010-01-01

    We present a novel approach to visually locate bodies of research within the sciences, both at each moment of time and dynamically. This article describes how this approach fits with other efforts to locally and globally map scientific outputs. We then show how these science overlay maps help benchm

  13. Assessing the crossdisciplinarity of technology-enhanced learning with science overlay maps and diversity measures

    NARCIS (Netherlands)

    Kalz, Marco; Specht, Marcus

    2013-01-01

    This paper deals with the assessment of the crossdisciplinarity of technology-enhanced learning (TEL). Based on a general discussion of the concept interdisciplinarity and a summary of the discussion in the field two empirical methods from scientometrics are introduced and applied. Science overlay m

  14. Precision-guided surgical navigation system using laser guidance and 3D autostereoscopic image overlay.

    Science.gov (United States)

    Liao, Hongen; Ishihara, Hirotaka; Tran, Huy Hoang; Masamune, Ken; Sakuma, Ichiro; Dohi, Takeyoshi

    2010-01-01

    This paper describes a precision-guided surgical navigation system for minimally invasive surgery. The system combines a laser guidance technique with a three-dimensional (3D) autostereoscopic image overlay technique. Images of surgical anatomic structures superimposed onto the patient are created by employing an animated imaging method called integral videography (IV), which can display geometrically accurate 3D autostereoscopic images and reproduce motion parallax without the need for special viewing or tracking devices. To improve the placement accuracy of surgical instruments, we integrated an image overlay system with a laser guidance system for alignment of the surgical instrument and better visualization of patient's internal structure. We fabricated a laser guidance device and mounted it on an IV image overlay device. Experimental evaluations showed that the system could guide a linear surgical instrument toward a target with an average error of 2.48 mm and standard deviation of 1.76 mm. Further improvement to the design of the laser guidance device and the patient-image registration procedure of the IV image overlay will make this system practical; its use would increase surgical accuracy and reduce invasiveness.

  15. Interactive overlays: a new method for generating global journal maps from Web-of-Science data

    NARCIS (Netherlands)

    Leydesdorff, L.; Rafols, I.

    2012-01-01

    Recent advances in methods and techniques enable us to develop interactive overlays to a global map of science based on aggregated citation relations among the 9162 journals contained in the Science Citation Index and Social Science Citation Index 2009. We first discuss the pros and cons of the vari

  16. A Novel Approach to Overlay Multicasting Schemes for Multi-Hop Ad-Hoc Networks

    Science.gov (United States)

    Kang, Namhi; Oh, Jejun; Kim, Younghan

    Multicast is an efficient transport mechanism for group-based community communications and mobile ad-hoc networks (MANET) is recently regarded as a promising solution for supporting ubiquitous computing as an underlying network technology. However, it is challenging to deploy the multicast mechanism used in a wired network directly into MANET owing to scarce resources in wireless networks and unpredictable changes in network topology. Several multicast mechanisms have been proposed in the literature to overcome these limitations. In MANET, especially, overlay multicasting schemes present several advantages over network-based multicasting schemes. However we have observed a common limitation of previously proposed overlay multicasting schemes. They introduce redundant data transmissions that waste network bandwidth and the battery of relay nodes. The observation motivated us to propose an efficient way to create and maintain a “semi-overlay structure” that utilizes a few nonmember nodes selected as branch nodes. The proposed scheme, called “SOMRP (Semi-overlay multicast routing protocol),” has been evaluated by using extensive network simulation in two different scenarios, comparing the performance of SOMRP with two previously proposed schemes. Simulation results show that SOMRP outperforms the two schemes in terms of the packet delivery ratio, transmission cost and end-to-end delay.

  17. Arbitration Intervention Worker (AIW) Services: Case Management Overlay in a Juvenile Diversion Program

    Science.gov (United States)

    Poythress, Norman G.; Dembo, Richard; DuDell, Gary; Wareham, Jennifer

    2006-01-01

    In this issue we describe a clinical trials study of the impact of adding specific case manager overlay services to "treatment as usual" services for youths in a Juvenile Arbitration Program. In this first article we describe the experimental intervention, the Arbitration Intervention Worker (AIW) service, which was provided to a randomly selected…

  18. Gossip-Based Topology Management Protocol for Self-Organizing Overlays

    Institute of Scientific and Technical Information of China (English)

    Chen Nao; Hu Ruimin; Zhu Yongqiong

    2011-01-01

    Gossip-based protocols have attracted more and more attention because of their simplicity and reliability.They can be applied to large-scale overlays for solving problems such as topology management,information dissemination,and aggregation.However,previous works sample nodes by their indegrees,without considering the differences in capability among nodes,and result in losing global load balancing.This paper proposes a load balancing gossip protocol for self-organizing overlays-LBTMP (Load-Balancing Topology Management Protocol),which takes into account the differences in capability among nodes and real loads.The novel protocol takes remainder service ability as the determinant for node selection metric,making light loading nodes from local neighbor view as returned samples preferentially.In the meantime,LBTMP selects light loading nodes preferentially for topology information exchange,which can diffuse light loading nodes over the whole overlay more quickly.Simulations show that returned sample node selection is biased to light loading nodes in a global view,and the overlay tends to load balancing.

  19. A study and simulation of the impact of high-order aberrations to overlay error distribution

    Science.gov (United States)

    Sun, G.; Wang, F.; Zhou, C.

    2011-03-01

    With reduction of design rules, a number of corresponding new technologies, such as i-HOPC, HOWA and DBO have been proposed and applied to eliminate overlay error. When these technologies are in use, any high-order error distribution needs to be clearly distinguished in order to remove the underlying causes. Lens aberrations are normally thought to mainly impact the Matching Machine Overlay (MMO). However, when using Image-Based overlay (IBO) measurement tools, aberrations become the dominant influence on single machine overlay (SMO) and even on stage repeatability performance. In this paper, several measurements of the error distributions of the lens of SMEE SSB600/10 prototype exposure tool are presented. Models that characterize the primary influence from lens magnification, high order distortion, coma aberration and telecentricity are shown. The contribution to stage repeatability (as measured with IBO tools) from the above errors was predicted with simulator and compared to experiments. Finally, the drift of every lens distortion that impact to SMO over several days was monitored and matched with the result of measurements.

  20. An Efficient Method for Performance Evaluation of Femto-Macro Overlay Systems

    DEFF Research Database (Denmark)

    Huang, Yue-Cai; Ko, King-Tim; Huang, Qian;

    2011-01-01

    This paper considers a two-tier femto-macro overlay network architecture, where groups of femtocells are overlaid by macrocells. The capacity of the femtocells is limited, thus redirection of blocked femto calls to the overlaid macrocell is used as a QoS assurance strategy. Similar overflow appro...

  1. Assessment of the Potential for Color Overlays to Enhance the Reading Skills of Enlisted Navy Recruits

    Science.gov (United States)

    2006-07-30

    sheets of colored plastic designed to be placed over text. A set of overlays include nine colors: rose, blue, yellow, purple, mint green, lime green...Reading by the colors: Overcoming dyslexia and other reading disabilities through the Irlen Method. Garden City Park, NY: Avery Publishing. Irlen, H

  2. FEM Analysis and Measurement of Residual Stress by Neutron Diffraction on the Dissimilar Overlay Weld Pipe

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Soo; Lee, Ho Jin; Woo, Wan Chuck; Seong, Baek Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Byeon, Jin Gwi; Park, Kwang Soo; Jung, In Chul [Doosan Heavy Industries and Construction Co., Changwon (Korea, Republic of)

    2010-10-15

    Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM Model on the dissimilar overlay weld pipe was made and analyzed by the ABAQUS Code (ABAQUS, 2004). Thermal analysis and stress analysis were performed, and the residual stress was calculated. Thirdly, the results of the FEM analysis were compared with those of the experimental methods

  3. Interactive overlay maps for US Patent (USPTO) data based on International Patent Classifications (IPC)

    NARCIS (Netherlands)

    Leydesdorff, L.; Kushnir, D.; Rafols, I.

    2014-01-01

    We report on the development of an interface to the US Patent and Trademark Office (USPTO) that allows for the mapping of patent portfolios as overlays to basemaps constructed from citation relations among all patents contained in this database during the period 1976-2011. Both the interface and the

  4. High order overlay modeling and APC simulation with Zernike-Legendre polynomials

    Science.gov (United States)

    Ju, JawWuk; Kim, MinGyu; Lee, JuHan; Sherwin, Stuart; Hoo, George; Choi, DongSub; Lee, Dohwa; Jeon, Sanghuck; Lee, Kangsan; Tien, David; Pierson, Bill; Robinson, John C.; Levy, Ady; Smith, Mark D.

    2015-03-01

    Feedback control of overlay errors to the scanner is a well-established technique in semiconductor manufacturing [1]. Typically, overlay errors are measured, and then modeled by least-squares fitting to an overlay model. Overlay models are typically Cartesian polynomial functions of position within the wafer (Xw, Yw), and of position within the field (Xf, Yf). The coefficients from the data fit can then be fed back to the scanner to reduce overlay errors in future wafer exposures, usually via a historically weighted moving average. In this study, rather than using the standard Cartesian formulation, we examine overlay models using Zernike polynomials to represent the wafer-level terms, and Legendre polynomials to represent the field-level terms. Zernike and Legendre polynomials can be selected to have the same fitting capability as standard polynomials (e.g., second order in X and Y, or third order in X and Y). However, Zernike polynomials have the additional property of being orthogonal over the unit disk, which makes them appropriate for the wafer-level model, and Legendre polynomials are orthogonal over the unit square, which makes them appropriate for the field-level model. We show several benefits of Zernike/Legendre-based models in this investigation in an Advanced Process Control (APC) simulation using highly-sampled fab data. First, the orthogonality property leads to less interaction between the terms, which makes the lot-to-lot variation in the fitted coefficients smaller than when standard polynomials are used. Second, the fitting process itself is less coupled - fitting to a lower-order model, and then fitting the residuals to a higher order model gives very similar results as fitting all of the terms at once. This property makes fitting techniques such as dual pass or cascading [2] unnecessary, and greatly simplifies the options available for the model recipe. The Zernike/Legendre basis gives overlay performance (mean plus 3 sigma of the residuals

  5. Precise X-ray and video overlay for augmented reality fluoroscopy.

    Science.gov (United States)

    Chen, Xin; Wang, Lejing; Fallavollita, Pascal; Navab, Nassir

    2013-01-01

    The camera-augmented mobile C-arm (CamC) augments any mobile C-arm by a video camera and mirror construction and provides a co-registration of X-ray with video images. The accurate overlay between these images is crucial to high-quality surgical outcomes. In this work, we propose a practical solution that improves the overlay accuracy for any C-arm orientation by: (i) improving the existing CamC calibration, (ii) removing distortion effects, and (iii) accounting for the mechanical sagging of the C-arm gantry due to gravity. A planar phantom is constructed and placed at different distances to the image intensifier in order to obtain the optimal homography that co-registers X-ray and video with a minimum error. To alleviate distortion, both X-ray calibration based on equidistant grid model and Zhang's camera calibration method are implemented for distortion correction. Lastly, the virtual detector plane (VDP) method is adapted and integrated to reduce errors due to the mechanical sagging of the C-arm gantry. The overlay errors are 0.38±0.06 mm when not correcting for distortion, 0.27±0.06 mm when applying Zhang's camera calibration, and 0.27±0.05 mm when applying X-ray calibration. Lastly, when taking into account all angular and orbital rotations of the C-arm, as well as correcting for distortion, the overlay errors are 0.53±0.24 mm using VDP and 1.67±1.25 mm excluding VDP. The augmented reality fluoroscope achieves an accurate video and X-ray overlay when applying the optimal homography calculated from distortion correction using X-ray calibration together with the VDP.

  6. Orthogonal Rings, Fiducial Markers, and Overlay Accuracy When Image Fusion is Used for EVAR Guidance.

    Science.gov (United States)

    Koutouzi, G; Sandström, C; Roos, H; Henrikson, O; Leonhardt, H; Falkenberg, M

    2016-11-01

    Evaluation of orthogonal rings, fiducial markers, and overlay accuracy when image fusion is used for endovascular aortic repair (EVAR). This was a prospective single centre study. In 19 patients undergoing standard EVAR, 3D image fusion was used for intra-operative guidance. Renal arteries and targeted stent graft positions were marked with rings orthogonal to the respective centre lines from pre-operative computed tomography (CT). Radiopaque reference objects attached to the back of the patient were used as fiducial markers to detect patient movement intra-operatively. Automatic 3D-3D registration of the pre-operative CT with an intra-operative cone beam computed tomography (CBCT) as well as 3D-3D registration after manual alignment of nearby vertebrae were evaluated. Registration was defined as being sufficient for EVAR guidance if the deviation of the origin of the lower renal artery was less than 3 mm. For final overlay registration, the renal arteries were manually aligned using aortic calcification and vessel outlines. The accuracy of the overlay before stent graft deployment was evaluated using digital subtraction angiography (DSA) as direct comparison. Fiducial markers helped in detecting misalignment caused by patient movement during the procedure. Use of automatic intensity based registration alone was insufficient for EVAR guidance. Manual registration based on vertebrae L1-L2 was sufficient in 7/19 patients (37%). Using the final adjusted registration as overlay, the median alignment error of the lower renal artery marking at pre-deployment DSA was 2 mm (0-5) sideways and 2 mm (0-9) longitudinally, mostly in a caudal direction. 3D image fusion can facilitate intra-operative guidance during EVAR. Orthogonal rings and fiducial markers are useful for visualization and overlay correction. However, the accuracy of the overlaid 3D image is not always ideal and further technical development is needed. Copyright © 2016 European Society for Vascular Surgery

  7. Use of a fluoroscopic overlay to guide femoral tunnel placement during posterior cruciate ligament reconstruction.

    Science.gov (United States)

    Araujo, Paulo H; Moloney, Gele; Rincon, Gustavo; Carey, Robert; Zhang, Xudong; Harner, Christopher

    2014-11-01

    Intraoperative recognition of the local anatomy of the posterior cruciate ligament (PCL) is difficult for many surgeons, and correct positioning of the graft can be challenging. To investigate the efficacy of an overlay system based on fluoroscopic landmarks in guiding femoral tunnel placement during PCL reconstruction. Controlled laboratory study. Twenty cadaveric knees were arthroscopically prepared, and their PCL femoral insertion sites were digitized. The digitized images were co-registered to computed tomography-acquired 3-dimensional bone models. Twenty surgeons with diverse backgrounds performed simulated arthroscopic reconstruction of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, first without and then with the aid of a lateral fluoroscopic image on which the position of a target insertion site based on literature data was displayed as an overlay. The surgeons were allowed to adjust tunnel placement in accordance with the displayed target position. A 3-way comparison was made of the tunnel positions placed by the surgeons, the native insertion site positions, and the literature-based positions. The overlay system was effective in helping surgeons to improve femoral tunnel placement toward the target and toward the anatomic insertion site (P 5 mm from the native insertion site. With the use of the overlay, 70% of the surgeons were overlay to guide intraoperative placement of the femoral tunnel(s) during PCL reconstruction can result in more anatomic reconstructions and therefore assist in re-creating native knee kinematics after PCL reconstruction. Intraoperative fluoroscopy is an effective, easy, and safe method for improving femoral tunnel positioning during PCL reconstruction. © 2014 The Author(s).

  8. Surface chemistry and catalytic properties of VO{sub X}/Ti-MCM-41 catalysts for dibenzothiophene oxidation in a biphasic system

    Energy Technology Data Exchange (ETDEWEB)

    González, J. [ESIQIE, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n, 07738 Col. Zacatenco, Mexico City (Mexico); Chen, L.F., E-mail: lchen@ipn.mx [ESIQIE, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n, 07738 Col. Zacatenco, Mexico City (Mexico); Wang, J.A.; Manríquez, Ma.; Limas, R. [ESIQIE, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n, 07738 Col. Zacatenco, Mexico City (Mexico); Schachat, P.; Navarrete, J. [Dirección de Investigación, Instituto Mexicano del Petróleo, Eje Lázaro Cárdenas 152, 07730 México D.F. (Mexico); Contreras, J.L. [Laboratorio de Catálisis y Polímeros, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-A, Av. San Pablo No. 180, 02200 México D.F. (Mexico)

    2016-08-30

    Highlights: • Oxidative desulfurization of model diesel was tested in a biphasic system. • ODS activity was proportional to the V{sup 5+}/(V{sup 4+} + V{sup 5+}) values of the catalysts. • Lewis acidity was related to vanadium content and catalytic activity. • 99.9% DBT was oxidized using 25%V{sub 2}O{sub 5}/Ti-MCM-41 at 60 °C within 60 min. - Abstract: A series of vanadium oxide supported on Ti-MCM-41 catalysts was synthesized via the incipient impregnation method by varying the vanadia loading from 5 wt% to 10, 15, 20 and 25 wt%. These catalysts were characterized by a variety of advanced techniques for investigating their crystalline structure, textural properties, and surface chemistry information including surface acidity, reducibility, vanadium oxidation states, and morphological features. The catalytic activities of the catalysts were evaluated in a biphasic reaction system for oxidative desulfurization (ODS) of a model diesel containing 300 ppm of dibenzothiophene (DBT) where acetonitrile was used as extraction solvent and H{sub 2}O{sub 2} as oxidant. ODS activity was found to be proportional to the V{sup 5+}/(V{sup 4+} + V{sup 5+}) values of the catalysts, indicating that the surface vanadium pentoxide (V{sub 2}O{sub 5}) was the active phase. Reaction temperature would influence significantly the ODS efficiency; high temperature, i.e., 80 °C, would lead to low ODS reaction due to the partial decomposition of oxidant. All the catalysts contained both Lewis and Brønsted acid sites but the former was predominant. The catalysts with low vanadia loading (5 or 10 wt%V{sub 2}O{sub 5}) had many Lewis acid sites and could strongly adsorb DBT molecule via the electron donation/acceptance action which resulted in an inhibition for the reaction of DBT with the surface peroxometallic species. The catalyst with high vanadia loading (25wt%V{sub 2}O{sub 5}/Ti-MCM-41) showed the highest catalytic activity and could remove 99.9% of DBT at 60 °C within 60 min.

  9. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Science.gov (United States)

    2010-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... be considered in any assay for quality of a gold filled, gold overlay and rolled gold plate industry...

  10. In situ growth of vanadia-titania nano/micro-porous layers with enhanced photocatalytic performance by micro-arc oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bayati, M.R., E-mail: bayati@iust.ac.i [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, P.O. Box 16845-161, Tehran (Iran, Islamic Republic of); Center of Excellence for Advanced Materials, Iran University of Science and Technology, P.O. Box 16845-195, Tehran (Iran, Islamic Republic of); Moshfegh, A.Z. [Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran (Iran, Islamic Republic of); Golestani-Fard, F. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, P.O. Box 16845-161, Tehran (Iran, Islamic Republic of); Center of Excellence for Advanced Materials, Iran University of Science and Technology, P.O. Box 16845-195, Tehran (Iran, Islamic Republic of)

    2010-03-30

    Micro-arc oxidation process was used to synthesize V{sub 2}O{sub 5}-TiO{sub 2} porous layers for the first time. Surface morphology and topography of the layers were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were also employed to evaluate phase structure and chemical composition of the layers. It was found that the V{sub 2}O{sub 5}-TiO{sub 2} layers consisted of anatase, rutile, and vanadium pentoxide phases fraction of which varied with the applied voltage and the electrolyte concentration. It was also revealed that pore size and surface roughness increased with the applied voltage and the electrolyte concentration. Optical properties of the layers were studied by a UV-vis spectrophotometer, and the band gap energies of the MAO-grown pure TiO{sub 2} and V{sub 2}O{sub 5}-TiO{sub 2} layers were respectively calculated as 3.21 and 2.56 eV. Furthermore, the composite layers exhibited a significantly enhanced photo-activity when compared to pure TiO{sub 2} layers. The photocatalytic reaction rate constants of degradation of methylene blue on the surface of the V{sub 2}O{sub 5}-TiO{sub 2} layers under ultraviolet and visible irradiations were measured as 0.0228 and 0.0117 min{sup -1}, respectively. As a consequence, micro-arc oxidation was deduced to be an appropriate and efficient method for synthesis of V{sub 2}O{sub 5}-TiO{sub 2} porous layers.

  11. CO Adsorption on Co(0001-Supported Pt Overlayers

    Directory of Open Access Journals (Sweden)

    N. J. Castellani

    2001-11-01

    Full Text Available The growth of Pt deposits on Co(0001 was followed by STM and XPS. The chemical reactivity of the resulting surface was checked by CO adsorption. Pt grows as dendritic islands on the Co terraces whereas forming stripes at the Co step edges. Annealing the sample has no apparent effect on the STM pictures. However, XPS suggests that a limited dilution of Pt in Co takes place. The adsorption of CO on the surface is drastically affected by the presence of Pt even for minute traces. The adsorption energy on the Pt areas is decreased by 40 %. The maximum coverage on the Co areas is also decreased. This indicates that Pt impurities diluted in Co have a high passivating power as a consequence of the induced electronic changes.

  12. Two Dimensional Array Based Overlay Network for Balancing Load of Peer-to-Peer Live Video Streaming

    Science.gov (United States)

    Faruq Ibn Ibrahimy, Abdullah; Rafiqul, Islam Md; Anwar, Farhat; Ibn Ibrahimy, Muhammad

    2013-12-01

    The live video data is streaming usually in a tree-based overlay network or in a mesh-based overlay network. In case of departure of a peer with additional upload bandwidth, the overlay network becomes very vulnerable to churn. In this paper, a two dimensional array-based overlay network is proposed for streaming the live video stream data. As there is always a peer or a live video streaming server to upload the live video stream data, so the overlay network is very stable and very robust to churn. Peers are placed according to their upload and download bandwidth, which enhances the balance of load and performance. The overlay network utilizes the additional upload bandwidth of peers to minimize chunk delivery delay and to maximize balance of load. The procedure, which is used for distributing the additional upload bandwidth of the peers, distributes the additional upload bandwidth to the heterogeneous strength peers in a fair treat distribution approach and to the homogeneous strength peers in a uniform distribution approach. The proposed overlay network has been simulated by Qualnet from Scalable Network Technologies and results are presented in this paper.

  13. MOC Image of Phobos with TES Temperature Overlay

    Science.gov (United States)

    1998-01-01

    This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. The Thermal Emission Spectrometer (TES) measured the brightness of thermal radiation at the same time the camera acquired this image. By analyzing the brightness, TES scientists could deduce the various fractions of the surface exposed to the Sun and their temperatures. This preliminary analysis shows that the surface temperature, dependent on slope and particle size, varies from a high of +25o F (-4o C) on the most illuminated slopes to -170o F (-112o C) in shadows. This large difference, and the fact that such differences can be found in close proximity, adds support to the notion that the surface of Phobos is covered by very small particles.Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  14. Li overlayer formation, oxidation and sputtering characteristics of Al-Li alloys and W/Al-Li composites for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A.R. (Argonne National Lab., IL (USA)); DeWald, A.B.; Scott, P.; Savage, H. (Corium Industries, Inc., Atlanta, GA (USA))

    1990-01-01

    The next generation of long pulse fusion devices will impose severe requirements on the properties of plasma-facing materials. In devices such as ITER, a divertor design is being considered, using a divertor plate which would be either tungsten or a low-Z material such as graphite or beryllium. Strongly segregating lithium alloys have been proposed as a means of producing a self-sustaining low-Z overlayer which lowers plasma Z{sub eff} and resists self-sputtering. Aluminum-lithium alloys are among the better-characterized lithium-bearing alloys, and it has been demonstrated that lithium segregates strongly in aluminum. However, aluminum has a relatively low melting point, and for low lithium concentrations, the lithium diffusion rate is too slow to replenish lithium at the rate at which it is eroded by the incoming plasma. It has been suggested previously that the superionic {beta} phase Al-Li alloy (48--54 at. % Li) should have high enough diffusivity to be able to replenish surface lithium, and that incorporation of the {beta}-phase AlLi in a composite with tungsten would provide high temperature strength and melt layer stability, along with significantly better thermal conductivity than pure tungsten. Such a composite has been fabricated, as well as a variation containing titanium as a means of controlling oxidation at grain boundaries. The Li overlayer formation, erosion, and replenishment are characterized for the {beta}-phase LiAl alloy, and W-AlLi and W-Ti-AlLi composites. It is found that if there is no oxide layer to inhibit the Li segregation, Li diffusion is extremely rapid, and an oxygen-free Li overlayer is formed which is stable under continuous ion beam sputtering. 21 refs., 7 figs.

  15. The Research of QoS Mechanisms Based Overlay Network%基于Overlay Network的QoS机制研究

    Institute of Scientific and Technical Information of China (English)

    邱春荣; 王湘渝

    2009-01-01

    重叠网服务质量(OverQoS)是一个崭新的研究课题.该文从应用的角度出发,根据OverQoS的驱动者不同,将基于重叠网的QoS架构分为主机系统驱动型和Overlay ISP驱动型,并剖析了两种OverQoS模型的内在特点,最后提出了相应的技术实现方案.

  16. Initial clinical experience with implantation of left ventricular lead guided by Overlay Ref for the treatment of congestive heart failure.

    Science.gov (United States)

    Zhang, Bu-Chun; Tang, Kai; Xu, Ya-Wei

    2011-01-01

    Cardiac resynchronization therapy (CRT) improves clinical outcome in selected patients with advanced congestive heart failure. The Overlay Ref technique may facilitate the procedure for implanting left ventricular (LV) pacing leads to deliver CRT. To assess the feasibility of deploying a LV pacing lead into a coronary sinus side branch guided by Overlay Ref. Data from 88 consecutive patients who met the CRT implantation criteria in our hospital between 28 November 2007 and 30 December 2009 were randomly assigned to two groups. Forty-four patients underwent CRT device implantation using Overlay Ref to guide target vein selection and advance a specifically designed pacing lead into the target vein (Overlay Ref group); 44 patients were conventionally implanted (control group). LV lead implantation was successful in all patients. Mean CRT total procedure times (skin-to-skin) were: Overlay Ref group, 80.7 ± 18.0 min; control group, 98.5 ± 32.2 min; p = 0.029. Mean placement of LV pacing lead into target vein times were: Overlay Ref group, 16.2 ± 7.7 min; control group, 36.4 ± 23.4 min; p=0.004. Mean total fluoroscopy times were: Overlay Ref group, 13.6 ± 4.3 min; control group, 23.8 ± 15.7 min; p=0.007. Mean LV lead fluoroscopy times were: Overlay Ref group, 5.7 ± 2.9 min; control group, 14.4 ± 4.6 min; p=0.003. No major complications occurred. Overlay Ref facilitates location of and entry into the coronary sinus, and shortens the duration of LV pacing lead implantation into the target vein. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  17. Ridge preservation comparing socket allograft alone to socket allograft plus facial overlay xenograft: a clinical and histologic study in humans.

    Science.gov (United States)

    Poulias, Evmenios; Greenwell, Henry; Hill, Margaret; Morton, Dean; Vidal, Ricardo; Shumway, Brian; Peterson, Thomas L

    2013-11-01

    Previous studies of ridge preservation showed a loss of ≈18% or 1.5 mm of crestal ridge width in spite of treatment. The primary aim of this randomized, controlled, masked clinical trial is to compare a socket graft to the same treatment plus a buccal overlay graft, both with a polylactide membrane, to determine if loss of ridge width can be prevented by use of an overlay graft. Twelve patients who served as positive controls received an intrasocket mineralized cancellous allograft (socket group), and 12 patients received the same socket graft procedure plus buccal overlay cancellous xenograft (overlay group). Horizontal ridge dimensions were measured with a digital caliper, and vertical ridge changes were measured from a stent. Before implant placement, at 4 months, a trephine core was obtained for histologic analysis. The mean horizontal ridge width at the crest for the socket group decreased from 8.7 ± 1.0 to 7.1 ± 1.5 mm for a mean loss of 1.6 ± 0.8 mm (P overlay group decreased from 8.4 ± 1.4 to 8.1 ± 1.4 mm for a mean loss of 0.3 ± 0.9 mm (P >0.05). The overlay group was significantly different from the socket group (P overlay group had 40% ± 16% (P >0.05). The overlay treatment significantly prevented loss of ridge width and preserved or augmented the buccal contour. The socket and overlay groups healed with a high percentage of vital bone.

  18. C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

    Science.gov (United States)

    Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

    2010-05-01

    Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1

  19. Holistic overlay control for multi-patterning process layers at the 10nm and 7nm nodes

    Science.gov (United States)

    Verstappen, Leon; Mos, Evert; Wardenier, Peter; Megens, Henry; Schmitt-Weaver, Emil; Bhattacharyya, Kaustuve; Adam, Omer; Grzela, Grzegorz; van Heijst, Joost; Willems, Lotte; Wildenberg, Jochem; Ignatova, Velislava; Chen, Albert; Elich, Frank; Rajasekharan, Bijoy; Vergaij-Huizer, Lydia; Lewis, Brian; Kea, Marc; Mulkens, Jan

    2016-03-01

    Multi-patterning lithography at the 10-nm and 7-nm nodes is driving the allowed overlay error down to extreme low values. Advanced high order overlay correction schemes are needed to control the process variability. Additionally the increase of the number of split layers results in an exponential increase of metrology complexity of the total overlay and alignment tree. At the same time, the process stack includes more hard-mask steps and becomes more and more complex, with as consequence that the setup and verification of the overlay metrology recipe becomes more critical. All of the above require a holistic approach that addresses total overlay optimization from process design to process setup and control in volume manufacturing. In this paper we will present the holistic overlay control flow designed for 10-nm and 7-nm nodes and illustrate the achievable ultimate overlay performance for a logic and DRAM use case. As figure 1 illustrates we will explain the details of the steps in the holistic flow. Overlay accuracy is the driver for target design and metrology tool optimization like wavelength and polarization. We will show that it is essential to include processing effects like etching and CMP which can result in a physical asymmetry of the bottom grating of diffraction based overlay targets. We will introduce a new method to create a reference overlay map, based on metrology data using multiple wavelengths and polarization settings. A similar approach is developed for the wafer alignment step. The overlay fingerprint correction using linear or high order correction per exposure (CPE) has a large amount of parameters. It is critical to balance the metrology noise with the ultimate correction model and the related metrology sampling scheme. Similar approach is needed for the wafer align step. Both for overlay control as well as alignment we have developed methods which include efficient use of metrology time, available for an in the litho-cluster integrated

  20. Effect of preemptive weld overlay sequence on residual stress distribution for dissimilar metal weld of Kori nuclear power plant pressurizer

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hong Yeol; Song, Tae Kwang; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of); Lee, Kyoung Soo; Park, Chi Yong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2008-07-01

    Weld overlay is one of the residual stress mitigation method which arrest crack. An overlay weld sued in this manner is termed a Preemptive Weld OverLay(PWOL). PWOL was good for distribution of residual stress of Dissimilar Metal Weld(DMW) by previous research. Because range of overlay welding is wide relatively, residual stress distribution on PWR is affected by welding sequence. In order to examine the effect of welding sequence, PWOL was applied to a specific DMW of KORI nuclear power plant by finite element analysis method. As a result, the welding direction that from nozzle to pipe is better good for residual stress distribution on PWR.

  1. Metagenomic and geochemical characterization of pockmarked sediments overlaying the Troll petroleum reservoir in the North Sea

    Directory of Open Access Journals (Sweden)

    Håvelsrud Othilde

    2012-09-01

    Full Text Available Abstract Background Pockmarks (depressions in the seabed have been discovered throughout the world’s oceans and are often related to hydrocarbon seepage. Although high concentrations of pockmarks are present in the seabed overlaying the Troll oil and gas reservoir in the northern North Sea, geological surveys have not detected hydrocarbon seepage in this area at the present time. In this study we have used metagenomics to characterize the prokaryotic communities inhabiting the surface sediments in the Troll area in relation to geochemical parameters, particularly related to hydrocarbon presence. We also investigated the possibility of increased potential for methane oxidation related to the pockmarks. Five metagenomes from pockmarks and plain seabed sediments were sequenced by pyrosequencing (Roche/454 technology. In addition, two metagenomes from seabed sediments geologically unlikely to be influenced by hydrocarbon seepage (the Oslofjord were included. The taxonomic distribution and metabolic potential of the metagenomes were analyzed by multivariate analysis and statistical comparisons to reveal variation within and between the two sampling areas. Results The main difference identified between the two sampling areas was an overabundance of predominantly autotrophic nitrifiers, especially Nitrosopumilus, and oligotrophic marine Gammaproteobacteria in the Troll metagenomes compared to the Oslofjord. Increased potential for degradation of hydrocarbons, especially aromatic hydrocarbons, was detected in two of the Troll samples: one pockmark sample and one from the plain seabed. Although presence of methanotrophic organisms was indicated in all samples, no overabundance in pockmark samples compared to the Oslofjord samples supports no, or only low level, methane seepage in the Troll pockmarks at the present time. Conclusions Given the relatively low content of total organic carbon and great depths of hydrocarbon containing sediments in the Troll

  2. A bi-overlayer type plasmonic photocatalyst consisting of mesoporous Au/TiO2 and CuO/SnO2 films separately coated on FTO.

    Science.gov (United States)

    Naya, Shin-ichi; Kume, Takahiro; Okumura, Nozomi; Tada, Hiroaki

    2015-07-21

    The principal purpose of this study is to present a new design for preparing highly active immobilized gold nanoparticle-based plasmonic photocatalysts. Gold nanoparticles were loaded on rutile TiO2 particles with a mean size of 80 nm (Au/TiO2) by the deposition precipitation method. The surface of SnO2 particles with a mean size of 100 nm was modified by copper(ii) oxide clusters (CuO/SnO2) with the loading amount (Γ/Cu ions nm(-2)) precisely controlled by the chemisorption-calcination cycle technique. Two mesoporous overlayers of Au/TiO2 and CuO/SnO2 were coated side by side on glass substrates with a fluorine-doped tin oxide film (FTO) using the doctor blade method (Au/mp-TiO2|FTO|CuO/mp-SnO2). As test reactions for assessing the visible-light activity, we carried out gas-phase decomposition of acetaldehyde and liquid-phase oxidation of alcohol. In each reaction, this bi-overlayer type catalyst shows a high level of visible-light activity much exceeding those of Au/TiO2 particles and a Au/mp-TiO2|FTO mono-overlayer type catalyst [J. Phys. Chem. C, 2014, 118, 26887]. To confirm the origin of the striking visible-light activity, we studied the electrocatalytic activity of CuO/mp-SnO2|FTO electrodes for the oxygen reduction reaction (ORR). Both the visible-light activity of Au/mp-TiO2|FTO|CuO/mp-SnO2 and the electrocatalytic activity of CuO/mp-SnO2|FTO for ORR strongly depend on the Γ value. A good positive correlation has been found between the visible-light activities and the electrocatalytic activity for ORR. The striking activity of the present bi-overlayer type catalyst can be attributed to the efficient and long-range charge separation by the vectorial electron transport (Au(oxidation sites) → TiO2→ FTO, SnO2→ CuO(reduction sites)) and the excellent electrocatalytic activity of the CuO clusters.

  3. Interaction of carbon dioxide with Cu overlayers on Pt(111)

    DEFF Research Database (Denmark)

    Schumacher, N.; Andersson, Klas Jerker; Grabow, L.C.

    2008-01-01

    Experimental and theoretical studies on the interaction of carbon dioxide with pseudomorphic and rough copper layers deposited on a platinum (111) single crystal are reported. Evidence for carbon dioxide dissociation and carbonate formation is presented and the relevance to methanol synthesis......) reveals a broad high temperature desorption state for CO2 with peak maximum around 450 K. X-ray photoelectron spectroscopy (XPS) shows that approximately one third of the oxygen accumulated on the surface upon CO2 exposure remains after TPD, indicative of carbonate formation via CO2 dissociation supplying...... O-ads and then facile CO2 + O-ads association, as well as subsequent decomposition at higher temperatures. Density functional theory studies of stepped Cu and Cu/Pt slabs reproduce vibrational frequencies of the carbonate, suggesting a nearly flat tridentate configuration at steps/defect sites....

  4. Overlay Network技术在云计算数据中心中的应用

    Institute of Scientific and Technical Information of China (English)

    马文杰

    2014-01-01

    随着云计算技术的飞速普及和发展,传统的数据中心逐渐向由各种虚拟化技术所支撑的云数据中心转变.服务器虚拟化、存储虚拟化已被大量运用在数据中心的组建中,新型的云数据中心对组网提出了新的要求.overlay network技术作为一种网络虚拟化技术,为解决云数据中心的组网问题提供技术支持.本文对overlay network技术进行了分析研究,并探讨了其在云数据中心中的应用.

  5. Impact of Improper Gaussian Signaling on the Achievable Rate of Overlay Cognitive Radio

    KAUST Repository

    Amin, Osama

    2017-05-12

    Improper Gaussian signaling (IGS) has been recently shown to provide performance improvements in underlay cognitive radio systems as opposed to the conventional proper Gaussian signaling (PGS) scheme. For the first time, this paper implements IGS scheme in overlay cognitive radio system, where the secondary transmitter broadcasts a mixture of two different signals. The first signal is selected from the PGS scheme to support the primary message transmission. On the other hand, the second signal is chosen to be from the IGS scheme in order to reduce the interference effect on the primary receiver. We then optimally design the overlay cognitive radio that employs IGS to maximize the secondary link achievable rate while satisfying the minimum rate requirement of the primary network. In particular, we derive closed form expressions for the circularity coefficient used in the IGS scheme and the power distribution parameters. Simulation results are provided to support our theoretical derivations.

  6. Cast titanium overlay denture for a geriatric patient with a reduced vertical dimension.

    Science.gov (United States)

    Guttal, Satyabodh; Patil, Narendra P

    2005-12-01

    An older patient reporting to the dental surgery for his/her dental treatment is becoming a common occurrence. Improved oral hygiene has meant that teeth are retained for a longer time, along with the potential problems of attrition, decreased vertical dimension, temporomandibular joint discomfort/strain, and poor aesthetics. The case in question is that of a 65-year-old male patient who had severe attrition in the lower arch, temporomandibular joint pain and reduced vertical dimension. The maxillary arch had previously been restored with a fixed partial prosthesis. For restoration of the lower teeth, a removable cast titanium overlay denture was fabricated incorporating an increased vertical dimension. Porcelain facings were placed to restore the aesthetics of the anterior teeth. The titanium was cast in a semi-automatic electric arc, pressure type casting machine. A titanium overlay denture with porcelain facing on the anterior teeth may provide a means of restoring a patient's concerns regarding aesthetics and function.

  7. Science overlay maps: a new tool for research policy and library management

    CERN Document Server

    Rafols, Ismael; Leydesdorff, Loet

    2009-01-01

    We present a novel approach to visually locate bodies of research within the sciences, both at each moment of time and dynamically. This article describes how this approach fits with other efforts to locally and globally map scientific outputs. We then show how these science overlay maps help benchmark, explore collaborations, and track temporal changes, using examples of universities, corporations, funding agencies, and research topics. We address conditions of application, with their advantages, downsides and limitations. Overlay maps especially help investigate the increasing number of scientific developments and organisations that do not fit within traditional disciplinary categories. We make these tools accessible to help researchers explore the ongoing socio-cognitive transformation of science and technology systems.

  8. DEAON: dynamically-evolving active overlay networks for scalable information retrieval

    Institute of Scientific and Technical Information of China (English)

    Huang Xinli; Ma Fanyuan

    2007-01-01

    In this paper,we propose the dynamically-evolving active overlay network(DEAON),which is an efficient,scalable yet simple protocol to facilitate applications of decentralized information retrieval in P2P networks.DEAON consists of three novel components:a Desirable Topology Construction and Adantation algorithm to guide the evolution of the overlay topology towards a small-world-like graph;a Semantic-based Neighbor Selection scheme to conduct an online neighbor ranking;a Topology-aware Intelligent Search mechanism to forward incoming queries to deliberately selected neighbors.We deploy and compare DEAON with other several existing distributed search techniques over static and dynamic environments.The results indicate that DEAON outperforms its competitors by achieving higher recall rate while using much less network resources,in both of the above environments.

  9. Application of graph overlay method to environmental impact assessment of railway noise

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-ping; YANG Xiao-yu; MA Chao-qun; RAN Mao-ping

    2005-01-01

    The graph overlay method is used to evaluate the noise impact of route alignment and the results can serve as a reference for the route alignment optimal selection. The geographic information system(GIS), with its powerful function of handling attribute data and spatial analysis, is adopted to calculate the noise comprehensive impact area of each alignment. With the graph overlay method, the noise vulnerability and noise impact distribution are both taken into account in the noise impact assessment of route alignment. With GIS, the efficiency of work and the reliability of result are greatly improved. By a combination of them, the noise impact on environment is fully presented in a visual way and the assessment result has vital value in route alignment optimal selection. A detailed case study is illustrated and the efficiency of the method is verified.

  10. A Secure and Stable Multicast Overlay Network with Load Balancing for Scalable IPTV Services

    Directory of Open Access Journals (Sweden)

    Tsao-Ta Wei

    2012-01-01

    Full Text Available The emerging multimedia Internet application IPTV over P2P network preserves significant advantages in scalability. IPTV media content delivered in P2P networks over public Internet still preserves the issues of privacy and intellectual property rights. In this paper, we use SIP protocol to construct a secure application-layer multicast overlay network for IPTV, called SIPTVMON. SIPTVMON can secure all the IPTV media delivery paths against eavesdroppers via elliptic-curve Diffie-Hellman (ECDH key exchange on SIP signaling and AES encryption. Its load-balancing overlay tree is also optimized from peer heterogeneity and churn of peer joining and leaving to minimize both service degradation and latency. The performance results from large-scale simulations and experiments on different optimization criteria demonstrate SIPTVMON's cost effectiveness in quality of privacy protection, stability from user churn, and good perceptual quality of objective PSNR values for scalable IPTV services over Internet.

  11. A TWO-LAYER RECURRENT NEURAL NETWORK BASED APPROACH FOR OVERLAY MULTICAST

    Institute of Scientific and Technical Information of China (English)

    Liu Shidong; Zhang Shunyi; Zhou Jinquan; Qiu Gong'an

    2008-01-01

    Overlay multicast has become one of the most promising multicast solutions for IP network, and Neutral Network(NN) has been a good candidate for searching optimal solutions to the constrained shortest routing path in virtue of its powerful capacity for parallel computation. Though traditional Hopfield NN can tackle the optimization problem, it is incapable of dealing with large scale networks due to the large number of neurons. In this paper, a neural network for overlay multicast tree computation is presented to reliably implement routing algorithm in real time. The neural network is constructed as a two-layer recurrent architecture, which is comprised of Independent Variable Neurons (IDVN) and Dependent Variable Neurons (DVN), according to the independence of the decision variables associated with the edges in directed graph. Compared with the heuristic routing algorithms, it is characterized as shorter computational time, fewer neurons, and better precision.

  12. A Hybrid P2P Overlay Network for Non-strictly Hierarchically Categorized Content

    Science.gov (United States)

    Wan, Yi; Asaka, Takuya; Takahashi, Tatsuro

    In P2P content distribution systems, there are many cases in which the content can be classified into hierarchically organized categories. In this paper, we propose a hybrid overlay network design suitable for such content called Pastry/NSHCC (Pastry for Non-Strictly Hierarchically Categorized Content). The semantic information of classification hierarchies of the content can be utilized regardless of whether they are in a strict tree structure or not. By doing so, the search scope can be restrained to any granularity, and the number of query messages also decreases while maintaining keyword searching availability. Through simulation, we showed that the proposed method provides better performance and lower overhead than unstructured overlays exploiting the same semantic information.

  13. Research on P2P Overlay Network Model with Small-world Features

    Directory of Open Access Journals (Sweden)

    Hao LIU

    2013-09-01

    Full Text Available Topology structure of P2P network decides its system performance. However, the existing P2P network models don’t take clustering and symmetry of nodes into account. Based on the algebra and graph theory method of Cayley graph, this paper proposes a novel P2P overlay network model with small-world features. Its simplicity and symmetry can ensure the self-organization and scalability of P2P network. The results of analysis and experiment shows that this model provides better robustness, higher enquiry efficiency and better load balance than the existing P2P Overlay Network models such as Chord and CAN. Furthermore, it possesses the property of high clustering.

  14. A hierarchical P2P overlay network for interest-based media contents lookup

    Science.gov (United States)

    Lee, HyunRyong; Kim, JongWon

    2006-10-01

    We propose a P2P (peer-to-peer) overlay architecture, called IGN (interest grouping network), for contents lookup in the DHC (digital home community), which aims to provide a formalized home-network-extended construction of current P2P file sharing community. The IGN utilizes the Chord and de Bruijn graph for its hierarchical overlay network construction. By combining two schemes and by inheriting its features, the IGN efficiently supports contents lookup. More specifically, by introducing metadata-based lookup keyword, the IGN offers detailed contents lookup that can reflect the user interests. Moreover, the IGN tries to reflect home network environments of DHC by utilizing HG (home gateway) of each home network as a participating node of the IGN. Through experimental and analysis results, we show that the IGN is more efficient than Chord, a well-known DHT (distributed hash table)-based lookup protocol.

  15. DSP overlay program design%DSP覆盖(Overlay)程序设计

    Institute of Scientific and Technical Information of China (English)

    吴洁; 李尚柏

    2014-01-01

    The fundamental of the overlay program design technology is to divide the task to several function modules through the modularized designing idea. The memory just need to load the module which would be executed currently, and do not load the others . When the other modules need to be executed, the modules in memory would be unloaded firstly, and then the modules need to execute would be load to memory. As far as the usage condition of memory to be concerned, overlay technology and dynamic link libraries(DLL) is highly similar. With the target platform of TM320C6000 series DSP, this article provide the ways and implementation steps for DSP overlay program design technology through a concrete instance, and discuss every link of the overlay program design technology in detail.%Overlay程序设计技术的基本原理是利用模块化设计思想,将任务划分成多个功能模块,在内存中只加载当前需要执行的模块,不加载其他暂不执行的模块。但当其他模块需要执行时,首先将内存中的模块卸载,然后将需要执行的模块再加载到内存。就内存的使用情况而言,Overlay技术与动态链接库是非常类似的。本文以TM320C6000系列DSP为目标平台,通过一个具体实例给出开发DSP覆盖(Overlay)程序设计技术的方法和实现步骤,详细地讨论了Overlay程序设计技术各个环节。

  16. Nasal bone grafts from the removed hump used as overlay grafts to camouflage concave lateral crura.

    Science.gov (United States)

    Kubilay, Utku; Erdogdu, Suleyman; Sezen, Ozan Seymen

    2014-01-01

    Alar cartilage consists of a medial crus, middle crus and lateral crus. The lateral crus is an important aesthetic and functional structure of the nose. A 32-year-old male patient with concave lateral crura was operated by the authors. An open rhinoplasty with a dorsal approach to the septum is preferred. The nasal bones harvested from the hump, which is an autogenous graft trimmed and sutured on both concave lateral crura as an overlay camouflage grafts. Satisfactory result was achieved.

  17. Association of Lateral Crural Overlay Technique With Strength of the Lower Lateral Cartilages.

    Science.gov (United States)

    Insalaco, Louis; Rashes, Emma R; Rubin, Samuel J; Spiegel, Jeffrey H

    2017-07-06

    The lateral crural overlay technique is a powerful technique for altering nasal tip projection and rotation. By overlapping and thus shortening the lateral crura, the nasal tip is shortened and rotated upward, thus decreasing projection and increasing rotation. There is no data to show the association of this technique with the strength of the lower lateral cartilage. Strengthening of the lower lateral cartilages would presumably lead to resistance to external nasal valve collapse and improved airway. In this cadaver study, we set out to determine the differences in the strength and resilience of the lateral crura after performing lateral crural overlay using 2 different techniques. Seven individual lower lateral cartilages were harvested from 6 cadavers for analysis. Each of the 7 cartilages was included sequentially in 3 test groups in the following order: a preprocedure group (preP), a postprocedure group (postP) in which the lateral crural overlay technique was performed, and a postprocedure with glue group (postPG) in which cyanoacrylate glue was added to the postP cartilages to simulate cartilage healing. A force gauge was used to measure the force required to deflect the lower lateral cartilages distances from 1 to 6 mm. Differences measured in newtons (N) for strength and resilience of lateral crura between the preP, postP, and postPG groups. A statistically significant increase in lower lateral cartilage resilience was noted between the preP and postPG groups at all distances of tip deflection (1 mm, 0.20 vs 0.70 N; P overlay technique affords increased strength and resilience to the lateral crura of the lower lateral cartilages, which should in turn decrease the likelihood of external nasal valve collapse postoperatively. NA.

  18. Identification of Lipid Binding Modulators Using the Protein-Lipid Overlay Assay.

    Science.gov (United States)

    Tang, Tuo-Xian; Xiong, Wen; Finkielstein, Carla V; Capelluto, Daniel G S

    2017-01-01

    The protein-lipid overlay assay is an inexpensive, easy-to-implement, and high-throughput methodology that employs nitrocellulose membranes to immobilize lipids in order to rapid screen and identify protein-lipid interactions. In this chapter, we show how this methodology can identify potential modulators of protein-lipid interactions by screening water-soluble lipid competitors or even the introduction of pH changes during the binding assay to identify pH-dependent lipid binding events.

  19. Reestablishment of occlusion through overlay removable partial dentures: a case report

    OpenAIRE

    Bataglion, César; Hotta, Takami Hirono; Matsumoto, Wilson; Ruellas, Carlos Ventura de Oliveira

    2012-01-01

    Loss of posterior teeth may cause an imbalance in the stomatognathic system. Overlay removable partial dentures (ORPD) are a reversible and relatively inexpensive treatment for patients with severely worn teeth. This paper presents a treatment with ORPD in a 55-year-old male patient who had severe attrition in the maxillary and mandibular teeth, temporomandibular joint pain and reduced vertical dimension of occlusion (VDO). The treatment consisted in the reestablishment of the VDO using Lucia...

  20. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  1. In-die photomask registration and overlay metrology with PROVE using 2D correlation methods

    Science.gov (United States)

    Seidel, D.; Arnz, M.; Beyer, D.

    2011-11-01

    According to the ITRS roadmap, semiconductor industry drives the 193nm lithography to its limits, using techniques like double exposure, double patterning, mask-source optimization and inverse lithography. For photomask metrology this translates to full in-die measurement capability for registration and critical dimension together with challenging specifications for repeatability and accuracy. Especially, overlay becomes more and more critical and must be ensured on every die. For this, Carl Zeiss SMS has developed the next generation photomask registration and overlay metrology tool PROVE® which serves the 32nm node and below and which is already well established in the market. PROVE® features highly stable hardware components for the stage and environmental control. To ensure in-die measurement capability, sophisticated image analysis methods based on 2D correlations have been developed. In this paper we demonstrate the in-die capability of PROVE® and present corresponding measurement results for shortterm and long-term measurements as well as the attainable accuracy for feature sizes down to 85nm using different illumination modes and mask types. Standard measurement methods based on threshold criteria are compared with the new 2D correlation methods to demonstrate the performance gain of the latter. In addition, mask-to-mask overlay results of typical box-in-frame structures down to 200nm feature size are presented. It is shown, that from overlay measurements a reproducibility budget can be derived that takes into account stage, image analysis and global effects like mask loading and environmental control. The parts of the budget are quantified from measurement results to identify critical error contributions and to focus on the corresponding improvement strategies.

  2. Microeconomics-based resource allocation in overlay networks by using non-strategic behavior modeling

    Science.gov (United States)

    Analoui, Morteza; Rezvani, Mohammad Hossein

    2011-01-01

    Behavior modeling has recently been investigated for designing self-organizing mechanisms in the context of communication networks in order to exploit the natural selfishness of the users with the goal of maximizing the overall utility. In strategic behavior modeling, the users of the network are assumed to be game players who seek to maximize their utility with taking into account the decisions that the other players might make. The essential difference between the aforementioned researches and this work is that it incorporates the non-strategic decisions in order to design the mechanism for the overlay network. In this solution concept, the decisions that a peer might make does not affect the actions of the other peers at all. The theory of consumer-firm developed in microeconomics is a model of the non-strategic behavior that we have adopted in our research. Based on it, we have presented distributed algorithms for peers' "joining" and "leaving" operations. We have modeled the overlay network as a competitive economy in which the content provided by an origin server can be viewed as commodity and the origin server and the peers who multicast the content to their downside are considered as the firms. On the other hand, due to the dual role of the peers in the overlay network, they can be considered as the consumers as well. On joining to the overlay economy, each peer is provided with an income and tries to get hold of the service regardless to the behavior of the other peers. We have designed the scalable algorithms in such a way that the existence of equilibrium price (known as Walrasian equilibrium price) is guaranteed.

  3. Clinical Applications of a CT Window Blending Algorithm: RADIO (Relative Attenuation-Dependent Image Overlay).

    Science.gov (United States)

    Mandell, Jacob C; Khurana, Bharti; Folio, Les R; Hyun, Hyewon; Smith, Stacy E; Dunne, Ruth M; Andriole, Katherine P

    2017-06-01

    A methodology is described using Adobe Photoshop and Adobe Extendscript to process DICOM images with a Relative Attenuation-Dependent Image Overlay (RADIO) algorithm to visualize the full dynamic range of CT in one view, without requiring a change in window and level settings. The potential clinical uses for such an algorithm are described in a pictorial overview, including applications in emergency radiology, oncologic imaging, and nuclear medicine and molecular imaging.

  4. Monoplane 3D Overlay Roadmap versus Conventional Biplane 2D Roadmap Technique for Neurointervenional Procedures

    Science.gov (United States)

    Jang, Dong-Kyu; Stidd, David A.; Schafer, Sebastian; Chen, Michael; Moftakhar, Roham

    2016-01-01

    Purpose We investigated whether a 3D overlay roadmap using monoplane fluoroscopy offers advantages over a conventional 2D roadmap using biplane fluoroscopy during endovascular aneurysm treatment. Materials and Methods A retrospective chart review was conducted for 131 consecutive cerebral aneurysm embolizations by three neurointerventionalists at a single institution. Allowing for a transition period, the periods from January 2012 to August 2012 (Time Period 1) and February 2013 to July 2013 (Time Period 2) were analyzed for radiation exposure, contrast administration, fluoroscopy time, procedure time, angiographic results, and perioperative complications. Two neurointerventionalists (Group 1) used a conventional 2D roadmap for both Time Periods, and one neurointerventionalist (Group 2) transitioned from a 2D roadmap during Time Period 1 to a 3D overlay roadmap during Time Period 2. Results During Time Period 2, Group 2 demonstrated reduced fluoroscopy time (p<0.001), procedure time (P=0.023), total radiation dose (p=0.001), and fluoroscopy dose (P=0.017) relative to Group 1. During Time Period 2, there was no difference of immediate angiographic results and procedure complications between the two groups. Through the transition from Time Period 1 to Time Period 2, Group 2 demonstrated decreased fluoroscopy time (p< 0.001), procedure time (p=0.022), and procedure complication rate (p=0.041) in Time Period 2 relative to Time Period 1. Conclusion The monoplane 3D overlay roadmap technique reduced fluoroscopy dose and fluoroscopy time during neurointervention of cerebral aneurysms with similar angiographic occlusions and complications rate relative to biplane 2D roadmap, which implies possible compensation of limitations of monoplane fluoroscopy by 3D overlay technique. PMID:27621947

  5. Novel indazole non-nucleoside reverse transcriptase inhibitors using molecular hybridization based on crystallographic overlays.

    Science.gov (United States)

    Jones, Lyn H; Allan, Gill; Barba, Oscar; Burt, Catherine; Corbau, Romuald; Dupont, Thomas; Knöchel, Thorsten; Irving, Steve; Middleton, Donald S; Mowbray, Charles E; Perros, Manos; Ringrose, Heather; Swain, Nigel A; Webster, Robert; Westby, Mike; Phillips, Chris

    2009-02-26

    A major problem associated with non-nucleoside reverse transcriptase inhibitors (NNRTIs) for the treatment of HIV is their lack of resilience to mutations in the reverse transcriptase (RT) enzyme. Using structural overlays of the known inhibitors efavirenz and capravirine complexed in RT as a starting point, and structure-based drug design techniques, we have created a novel series of indazole NNRTIs that possess excellent metabolic stability and mutant resilience.

  6. Pasadena, California Perspective View with Aerial Photo and Landsat Overlay

    Science.gov (United States)

    2000-01-01

    This perspective view shows the western part of the city of Pasadena, California, looking north towards the San Gabriel Mountains. Portions of the cities of Altadena and La Canada-Flintridge are also shown. The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation data; Landsat data from November 11, 1986 provided the land surface color (not the sky) and U. S. Geological Survey digital aerial photography provides the image detail. The Rose Bowl, surrounded by a golf course, is the circular feature at the bottom center of the image. The Jet Propulsion Laboratory, is the cluster of large buildings north of the Rose Bowl at the base of the mountains. A large landfill, Scholl Canyon, is the smooth area in the lower left corner of the scene.This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Wildfires strip the mountains of vegetation, increasing the hazards from flooding and mudflows for several years afterwards. Data such as shown on this image can be used to predict both how wildfires will spread over the terrain and also how mudflows will be channeled down the canyons.For a full-resolution, annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site] The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is

  7. Kamchatka Peninsula, Russia 3-D Perspective with Landsat Overlay

    Science.gov (United States)

    2000-01-01

    This three-dimensional perspective view, looking up the Tigil River, shows the western side of the volcanically active Kamchatka Peninsula, Russia. The image shows that the Tigil River has eroded down from a higher and differing landscape and now flows through, rather than around the large green-colored bedrock ridge in the foreground. The older surface was likely composed of volcanic ash and debris from eruptions of nearby volcanoes. The green tones indicate that denser vegetation grows on south facing sunlit slopes at the northern latitudes. High resolution SRTM elevation data will be used by geologists to study how rivers shape the landscape, and by ecologists to study the influence of topography on ecosystems.This image shows how data collected by the Shuttle Radar Topography Mission (SRTM) can be used to enhance other satellite images. Color and natural shading are provided by a Landsat 7 image acquired on January 31, 2000. Terrain perspective and shading were derived from SRTM elevation data acquired on February 12, 2000. Topography is exaggerated by about six times vertically. The United States Geological Survey's Earth Resources Observations Systems (EROS) DataCenter, Sioux Falls, South Dakota, provided the Landsat data.The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion

  8. Simulated Prosthesis Overlay for Patient-Specific Planning of Transcatheter Aortic Valve Implantation Procedures.

    Science.gov (United States)

    Sündermann, Simon H; Gessat, Michael; Maier, Willibald; Kempfert, Jörg; Frauenfelder, Thomas; Nguyen, Thi D L; Maisano, Francesco; Falk, Volkmar

    2015-01-01

    We tested the hypothesis that simulated three-dimensional prosthesis overlay procedure planning may support valve selection in transcatheter aortic valve implantation (TAVI) procedures. Preoperative multidimensional computed tomography (MDCT) data sets from 81 consecutive TAVI patients were included in the study. A planning tool was developed, which semiautomatically creates a three-dimensional model of the aortic root from these data. Three-dimensional templates of the commonly used TAVI implants are spatially registered with the patient data and presented as graphic overlay. Fourteen physicians used the tool to perform retrospective planning of TAVI procedures. Results of prosthesis sizing were compared with the prosthesis size used in the actually performed procedure, and the patients were accordingly divided into three groups: those with equal size (concordance with retrospective planning), oversizing (retrospective planning of a smaller prosthesis), and undersizing (retrospective planning of a larger prosthesis). In the oversizing group, 85% of the patients had new pacemaker implantation. In the undersizing group, in 66%, at least mild paravalvular leakage was observed (greater than grade 1 in one third of the cases). In 46% of the patients in the equal-size group, neither of these complications was observed. Three-dimensional prosthesis overlay in MDCT-derived patient data for patient-specific planning of TAVI procedures is feasible. It may improve valve selection compared with two-dimensional MDCT planning and thus yield better outcomes.

  9. Monoplane 3D Overlay Roadmap versus Conventional Biplane 2D Roadmap Technique for Neurointervenional Procedures.

    Science.gov (United States)

    Jang, Dong-Kyu; Stidd, David A; Schafer, Sebastian; Chen, Michael; Moftakhar, Roham; Lopes, Demetrius K

    2016-09-01

    We investigated whether a 3D overlay roadmap using monoplane fluoroscopy offers advantages over a conventional 2D roadmap using biplane fluoroscopy during endovascular aneurysm treatment. A retrospective chart review was conducted for 131 consecutive cerebral aneurysm embolizations by three neurointerventionalists at a single institution. Allowing for a transition period, the periods from January 2012 to August 2012 (Time Period 1) and February 2013 to July 2013 (Time Period 2) were analyzed for radiation exposure, contrast administration, fluoroscopy time, procedure time, angiographic results, and perioperative complications. Two neurointerventionalists (Group 1) used a conventional 2D roadmap for both Time Periods, and one neurointerventionalist (Group 2) transitioned from a 2D roadmap during Time Period 1 to a 3D overlay roadmap during Time Period 2. During Time Period 2, Group 2 demonstrated reduced fluoroscopy time (poverlay roadmap technique reduced fluoroscopy dose and fluoroscopy time during neurointervention of cerebral aneurysms with similar angiographic occlusions and complications rate relative to biplane 2D roadmap, which implies possible compensation of limitations of monoplane fluoroscopy by 3D overlay technique.

  10. Use of the Soft-agar Overlay Technique to Screen for Bacterially Produced Inhibitory Compounds.

    Science.gov (United States)

    Hockett, Kevin L; Baltrus, David A

    2017-01-14

    The soft-agar overlay technique was originally developed over 70 years ago and has been widely used in several areas of microbiological research, including work with bacteriophages and bacteriocins, proteinaceous antibacterial agents. This approach is relatively inexpensive, with minimal resource requirements. This technique consists of spotting supernatant from a donor strain (potentially harboring a toxic compound(s)) onto a solidified soft agar overlay that is seeded with a bacterial test strain (potentially sensitive to the toxic compound(s)). We utilized this technique to screen a library of Pseudomonas syringae strains for intraspecific killing. By combining this approach with a precipitation step and targeted gene deletions, multiple toxic compounds produced by the same strain can be differentiated. The two antagonistic agents commonly recovered using this technique are bacteriophages and bacteriocins. These two agents can be differentiated using two simple additional tests. Performing a serial dilution on a supernatant containing bacteriophage will result in individual plaques becoming less in number with greater dilution, whereas serial dilution of a supernatant containing bacteriocin will result a clearing zone that becomes uniformly more turbid with greater dilution. Additionally, a bacteriophage will produce a clearing zone when spotted onto a fresh soft agar overlay seeded with the same strain, whereas a bacteriocin will not produce a clearing zone when transferred to a fresh soft agar lawn, owing to the dilution of the bacteriocin.

  11. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system.

    Science.gov (United States)

    Gao, Shengkui; Mondal, Suman B; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use.

  12. Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

    Science.gov (United States)

    Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

    2015-10-01

    The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (poverlay pattern was between 2 and 3. Emax with optimal cutoff at 45.1 kPa showed the highest Az value, sensitivity, specificity and accuracy among other quantitative SWE parameters (poverlay pattern and pathology (poverlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. A Prediction System Using a P2P Overlay Network for a Bus Arrival System

    Directory of Open Access Journals (Sweden)

    Ssu-Hsuan Lu

    2014-01-01

    Full Text Available Along with the evolution of times and the surge of metropolitan populations, government agencies often promote the construction of public transport. Unlike rail transportation or rapid transit systems, it is often difficult to estimate the vehicle arrival times at each station in a bus transportation system due to metropolitan transportation congestion. Traffic status is often monitored using wireless sensor networks (WSNs. However, WSNs are always separated from one another spatially. Recent studies have considered the connection of multiple sensor networks. This study considers a combination view of peer-to-peer (P2P overlay networks and WSN architecture to predict bus arrival times. Each bus station, which is also a P2P overlay peer, is connected in a P2P overlay network. A sensor installed in each bus can receive data via peers to obtain the moving speed of a bus. Then, each peer can exchange its data to predict bus arrival times at bus stations. This method can considerably increase the accuracy with which bus arrival times can be predicted and can provide traffic status with high precision. Furthermore, these data can also be used to plan new bus routes according to the information gathered.

  14. Restoration of the Occlusal Vertical Dimension with an Overlay Removable Partial Denture: A Clinical Report.

    Science.gov (United States)

    Zanardi, Piero Rocha; Santos, Mayara Silva; Stegun, Roberto Chaib; Sesma, Newton; Costa, Bruno; Laganá, Dalva Cruz

    2016-10-01

    The process of tooth loss throughout life associated with severe occlusal wear may pose a challenge in the rehabilitation of partially edentulous arches. In these cases, many therapeutic procedures are necessary because each tooth must be restored to obtain the correct anatomical contour and recover the occlusal vertical dimension (OVD). A removable partial denture (RPD) with occlusal/incisal coverage, also known as an overlay RPD, is an alternative treatment option with fewer interventions, and, consequently, lower cost. This clinical report reviews the principles involved in the clinical indication for an overlay RPD, as well as the necessary planning and execution, to discuss the feasibility and clinical effectiveness of this treatment, identifying the indications, advantages, and disadvantages of this procedure through the presentation of a clinical case. The overlay RPD can be an alternative treatment for special situations involving partially edentulous arches in patients who need reestablishment of the OVD and/or realignment of the occlusal plane, and it can be used as a temporary or definitive treatment. The main advantages of this type of treatment are its simplicity, reversibility, and relatively low cost; however, further studies are needed to ensure the efficacy of this treatment option. © 2015 by the American College of Prosthodontists.

  15. Structural evolution of the Pb/Si(111) interface with metal overlayer thickness

    Science.gov (United States)

    Souto-Casares, Jaime; Chan, Tzu-Liang; Chelikowsky, James R.; Ho, Kai-Ming; Wang, Cai-Zhuang; Zhang, S. B.

    2015-09-01

    We employ a real-space pseudopotential method to compute the structural energies of a prototypical metal-semiconductor interface. Specifically, we examine a Pb(111) film overlaid on a Si(111) substrate as a function of the metal thickness. For each layer of Pb, we fully relax the atomic coordinates and determine the lowest-energy structure. Owing to the lattice mismatch between the Pb and Si crystal structures, we consider a large supercell containing up to 1505 atoms for the largest system. Systems of this size remain challenging for most current computational approaches and require algorithms specifically designed for highly parallel computational platforms. We examine the structural properties of the interface with respect to the thickness of the metal overlayer, e.g., the corrugation of the profile of the Pb overlayer. The combined influence of the Si substrate and quantum confinement results in a rich profile for a transition between a thin overlayer (less than a few monolayers), where the corrugation is strong, and the bulk region (more than a half-dozen layers), where the overlaid Pb film is atomically flat. This work proves the feasibility of handling systems with such a level of complexity.

  16. Effect of oil overlay on inhibition potential of roscovitine in sheep cumulus-oocyte complexes.

    Science.gov (United States)

    Crocomo, L F; Marques Filho, W C; Ulian, C M V; Branchini, N S; Silva, D T; Ackermann, C L; Landim-Alvarenga, F C; Bicudo, S D

    2015-06-01

    Inhibitors of cyclin-dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus-oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor-free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (-) at 38.5°C and 5% CO2 . At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/-) exhibited total expansion while in both Rosco groups (+/-) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression. © 2015 Blackwell Verlag GmbH.

  17. Iron aluminide weld overlay coatings for boiler tube protection in coal-fired low NOx boilers

    Energy Technology Data Exchange (ETDEWEB)

    Banovic, S.W.; DuPont, J.N.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States). Energy Research Center

    1997-12-01

    Iron aluminide weld overlay coatings are currently being considered for enhanced sulfidation resistance in coal-fired low NO{sub x} boilers. The use of these materials is currently limited due to hydrogen cracking susceptibility, which generally increases with an increase in aluminum concentration of the deposit. The overall objective of this program is to attain an optimum aluminum content with good weldability and improved sulfidation resistance with respect to conventional materials presently in use. Research has been initiated using Gas Tungsten Arc Welding (GTAW) in order to achieve this end. Under different sets of GTAW parameters (wire feed speed, current), both single and multiple pass overlays were produced. Characterization of all weldments was conducted using light optical microscopy, scanning electron microscopy, and electron probe microanalysis. Resultant deposits exhibited a wide range of aluminum contents (5--43 wt%). It was found that the GTAW overlays with aluminum contents above {approximately}10 wt% resulted in cracked coatings. Preliminary corrosion experiments of 5 to 10 wt% Al cast alloys in relatively simple H{sub 2}/H{sub 2}S gas mixtures exhibited corrosion rates lower than 304 stainless steel.

  18. Managing Peer to Peer and Overlay Content Traffic in ISP Networks

    Directory of Open Access Journals (Sweden)

    Stanislaus Kaosoluchukwu Ogbuokebe

    2013-04-01

    Full Text Available Peer-to-Peer content distribution systems are major source of traffic in today’s internet services, Peer-to-peer (P2P traffic consumes network resources without creating additional revenue. It is estimated that high percentage of broadband bandwidth is consumed by downloads of music, games, video, and other content. The use of peer to peer systems introduces many new problems related to traffic engineering or network optimization. This research work will investigate characteristics and behavioural interactions between Peer to Peer overlay content distribution operations, as well as suggests/discuss algorithms for optimizing P2P content distribution overlay infrastructure and the internet service provider “ISP” network. Techniques to harmonise the relationship between P2P overlay content distribution services and the underlying network is also discussed. Indeed the system performance of a P2P network is critically affected by its overload, thus the processing load of the peers, the communication load and the system management load, must be carefully handled to obtain satisfactory system performance.

  19. Disbond detection with piezoelectric wafer active sensors in RC structures strengthened with FRP composite overlays

    Institute of Scientific and Technical Information of China (English)

    Victor Giurgiutiu; Kent Harries; Michael Petrou; Joel Bost; Josh B. Quattlebaum

    2003-01-01

    The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) for structural health monitoring (SHM) of reinforced concrete (RC) structures strengthened with fiber reinforced polymer (FRP) composite overlays is explored. First, the disbond detection method were developed on coupon specimens consisting of concrete blocks covered with an FRP composite layer. It was found that the prescnce of a disbond crack drastically changes the electromecbanical (E/M) impedance spectrum measured at the PWAS terminals. The spectral changes depend on the distance between the PWAS and the crack tip. Second, large scale experiments were conducted on a RC beam strengthened with carbon fiber reinforced polymer (CFRP) composite overlay. The beam was subject to an acccleratcd fatigue load regime in a three-point bending configuration up to a total of807,415 cycles. During these fatigue tests, the CFRP overlay experienced disbonding beginning at about 500,000 cycles. The PWAS were able to detect the disbonding before it could be reliably seen by visual inspection. Good correlation between the PWAS readings and the position and extent of disbond damage was observed. These preliminary results demonstrate the potential of PWAS technology for SHM of RC structures strengthened with FRP composite ovcrlays.

  20. Numerical evaluation of weld overlay applied to a pressurized water reactor nozzle mock-up

    Energy Technology Data Exchange (ETDEWEB)

    Rabello, Emerson G.; Silva, Luiz L.; Gomes, Paulo T.V., E-mail: egr@cdtn.b, E-mail: silvall@cdtn.b, E-mail: gomespt@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Integridade Estrutural

    2011-07-01

    The primary water stress corrosion cracking (PWSCC) is a major mechanism of failure in the primary circuit of PWR type nuclear power plants. The PWSCC is associated with the presence of corrosive environment, the susceptibility to corrosion cracking of the materials involved and the tensile stresses presence. Residual stresses generated during dissimilar materials welding can contribute to PWSCC. An alternative to the PWSCC mitigation is the application of external weld layers in the regions of greatest susceptibility to corrosion cracking. This process, called Weld Overlay (WOL), has been widely used in regions of dissimilar weld (low alloy steel and stainless steel with nickel alloy addition) of nozzles and pipes on the primary circuit in order to promote internal compressive stresses on the wall of these components. This paper presents the steps required to the numerical stress evaluation (by finite element method) during the dissimilar materials welding as well as application of Weld Overlay process in a nozzle mock-up. Thus, one can evaluate the effectiveness of the application of weld overlay process to internal compressive stress generation on the wall nozzle. (author)

  1. Energy Efficiency in MIMO Underlay and Overlay Device-to-Device Communications and Cognitive Radio Systems

    Science.gov (United States)

    Zappone, Alessio; Matthiesen, Bho; Jorswieck, Eduard Axel

    2017-02-01

    This paper addresses the problem of resource allocation for systems in which a primary and a secondary link share the available spectrum by an underlay or overlay approach. After observing that such a scenario models both cognitive radio and D2D communications, we formulate the problem as the maximization of the secondary energy efficiency subject to a minimum rate requirement for the primary user. This leads to challenging non-convex, fractional problems. In the underlay scenario, we obtain the global solution by means of a suitable reformulation. In the overlay scenario, two algorithms are proposed. The first one yields a resource allocation fulfilling the first-order optimality conditions of the resource allocation problem, by solving a sequence of easier fractional problems. The second one enjoys a weaker optimality claim, but an even lower computational complexity. Numerical results demonstrate the merits of the proposed algorithms both in terms of energy-efficient performance and complexity, also showing that the two proposed algorithms for the overlay scenario perform very similarly, despite the different complexity.

  2. Identification of cellular proteins that interact with Newcastle Disease Virus and human Respiratory Syncytial Virus by a two-dimensional virus overlay protein binding assay (VOPBA).

    Science.gov (United States)

    Holguera, Javier; Villar, Enrique; Muñoz-Barroso, Isabel

    2014-10-13

    Although it is well documented that the initial attachment receptors for Newcastle Disease Virus (NDV) and Respiratory Syncytial Virus (RSV) are sialic acid-containing molecules and glycosaminoglycans respectively, the exact nature of the receptors for both viruses remains to be deciphered. Moreover, additional molecules at the host cell surface might be involved in the entry mechanism. With the aim of identifying the cellular proteins that interact with NDV and RSV at the cell surface, we performed a virus overlay protein binding assay (VOPBA). Cell membrane lysates were separated by two dimensional (2D) gel electrophoresis and electrotransferred to PVDF membranes, after which they were probed with high viral concentrations. NDV interacted with a Protein Disulfide Isomerase from chicken fibroblasts. In the case of RSV, we detected 15 reactive spots, which were identified as six different proteins, of which nucleolin was outstanding. We discuss the possible role of PDI and nucleolin in NDV and RSV entry, respectively.

  3. A photoemission study of BaO overlayers adsorbed on W(110) and their interaction with H 2O, CO 2, and O 2

    Science.gov (United States)

    Mueller, D. R.; Kurtz, R. L.; Stockbauer, R. L.; Madey, T. E.; Shih, Arnold

    1990-11-01

    The electronic structure of barium oxide overlayers on W(110) and their interaction with H 2O, CO 2 and O 2 has been examined using ultraviolet photo electron spectroscopy. At room temperature water vapor and carbon dioxide react with a c(5 × 1)-BaO monolayer adsorbed on W(110) to produce adsorbed OH and CO 3 species. Heating the W(110)-c(5 × 1)-BaO surface following water or carbon dioxide exposure dissociates the adsorbed hydroxide or carbonate. On the lower coverage c(7 × 1)-BaO and c(2 × 4)-BaO adlayers complete dissociation of a fraction of the adsorbed species is evident at room temperature. The interaction of oxygen with W(110) is enhanced by the presence of barium oxide on the tungsten surface. These results are compared with the findings of a previous study of barium oxide films adsorbed on W(100).

  4. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization.

    Science.gov (United States)

    Whiteside, Wendy; Christensen, Jason; Zampi, Jeffrey D

    2015-01-01

    Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  5. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    Directory of Open Access Journals (Sweden)

    Wendy Whiteside

    2015-01-01

    Full Text Available Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  6. Two-layer critical dimensions and overlay process window characterization and improvement in full-chip computational lithography

    Science.gov (United States)

    Sturtevant, John L.; Liubich, Vlad; Gupta, Rachit

    2016-04-01

    Edge placement error (EPE) was a term initially introduced to describe the difference between predicted pattern contour edge and the design target for a single design layer. Strictly speaking, this quantity is not directly measurable in the fab. What is of vital importance is the relative edge placement errors between different design layers, and in the era of multipatterning, the different constituent mask sublayers for a single design layer. The critical dimensions (CD) and overlay between two layers can be measured in the fab, and there has always been a strong emphasis on control of overlay between design layers. The progress in this realm has been remarkable, accelerated in part at least by the proliferation of multipatterning, which reduces the available overlay budget by introducing a coupling of overlay and CD errors for the target layer. Computational lithography makes possible the full-chip assessment of two-layer edge to edge distances and two-layer contact overlap area. We will investigate examples of via-metal model-based analysis of CD and overlay errors. We will investigate both single patterning and double patterning. For single patterning, we show the advantage of contour-to-contour simulation over contour to target simulation, and how the addition of aberrations in the optical models can provide a more realistic CD-overlay process window (PW) for edge placement errors. For double patterning, the interaction of 4-layer CD and overlay errors is very complex, but we illustrate that not only can full-chip verification identify potential two-layer hotspots, the optical proximity correction engine can act to mitigate such hotspots and enlarge the joint CD-overlay PW.

  7. Brief Announcement: Decentralized Construction of Multicast Trees Embedded into P2P Overlay Networks based on Virtual Geometric Coordinates

    CERN Document Server

    Andreica, Mugurel Ionut; Sambotin, Ana-Delia; Tapus, Nicolae; 10.1145/1835698.1835766

    2010-01-01

    In this paper we consider the problem of efficiently constructing in a fully distributed manner multicast trees which are embedded into P2P overlays using virtual geometric node coordinates. We consider two objectives: to minimize the number of messages required for constructing a multicast tree by using the geometric properties of the P2P overlay, and to construct stable multicast trees when the lifetime durations of the peers are known.

  8. Utility of iodine overlay technique and virtual unenhanced images for the characterization of renal masses by dual-energy CT.

    Science.gov (United States)

    Song, Kyoung Doo; Kim, Chan Kyo; Park, Byung Kwan; Kim, Bohyun

    2011-12-01

    The objective of our study was to assess the utility of dual-energy CT for characterizing renal masses using iodine overlay techniques and virtual unenhanced images and to measure the potential radiation dose reduction for two-phase kidney CT compared with a standard three-phase protocol. Sixty patients with suspected renal masses underwent dual-energy CT including true unenhanced, dual-energy corticomedullary, and dual-energy late nephrographic phase imaging. Iodine overlay and virtual unenhanced images were derived from the corticomedullary and late nephrographic phases, respectively. The CT numbers of renal masses were calculated using the iodine overlay images superimposed on the virtual unenhanced images. The overall imaging quality of the true unenhanced images and of the virtual unenhanced images was also evaluated. The effective radiation doses for dual-energy CT and for true unenhanced imaging were calculated. For overlay or enhancement values on iodine overlay images, 36 simple cysts and 10 hemorrhagic cysts had an attenuation value of less than 20 HU, whereas 21 renal cell carcinomas showed an attenuation value of 20 HU or greater. Eleven angiomyolipomas contained macroscopic fat tissue. All renal masses were accurately classified on the basis of dual-energy CT. The imaging quality of the virtual unenhanced images from the corticomedullary and late nephrographic phases was inferior to the image quality of the true unenhanced images (p overlay techniques and virtual unenhanced images may be useful for characterizing renal masses.

  9. Visually assessed colour overlay features in shear-wave elastography for breast masses: quantification and diagnostic performance.

    Science.gov (United States)

    Gweon, Hye Mi; Youk, Ji Hyun; Son, Eun Ju; Kim, Jeong-Ah

    2013-03-01

    To determine whether colour overlay features can be quantified by the standard deviation (SD) of the elasticity measured in shear-wave elastography (SWE) and to evaluate the diagnostic performance for breast masses. One hundred thirty-three breast lesions in 119 consecutive women who underwent SWE before US-guided core needle biopsy or surgical excision were analysed. SWE colour overlay features were assessed using two different colour overlay pattern classifications. Quantitative SD of the elasticity value was measured with the region of interest including the whole breast lesion. For the four-colour overlay pattern, the area under the ROC curve (Az) was 0.947; with a cutoff point between pattern 2 and 3, sensitivity and specificity were 94.4 % and 81.4 %. According to the homogeneity of the elasticity, the Az was 0.887; with a cutoff point between reasonably homogeneous and heterogeneous, sensitivity and specificity were 86.1 % and 82.5 %. For the SD of the elasticity, the Az was 0.944; with a cutoff point of 12.1, sensitivity and specificity were 88.9 % and 89.7 %. The colour overlay features showed significant correlations with the quantitative SD of the elasticity (P overlay features and the SD of the elasticity in SWE showed excellent diagnostic performance and showed good correlations between them.

  10. Hurricane Rita Track Radar Image with Topographic Overlay

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Animation About the animation: This simulated view of the potential effects of storm surge flooding on Galveston and portions of south Houston was generated with data from the Shuttle Radar Topography Mission. Although it is protected by a 17-foot sea wall against storm surges, flooding due to storm surges caused by major hurricanes remains a concern. The animation shows regions that, if unprotected, would be inundated with water. The animation depicts flooding in one-meter increments. About the image: The Gulf Coast from the Mississippi Delta through the Texas coast is shown in this satellite image from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) overlain with data from the Shuttle Radar Topography Mission (SRTM), and the predicted storm track for Hurricane Rita. The prediction from the National Weather Service was published Sept. 22 at 4 p.m. Central Time, and shows the expected track center in black with the lighter shaded area indicating the range of potential tracks the storm could take. Low-lying terrain along the coast has been highlighted using the SRTM elevation data, with areas within 15 feet of sea level shown in red, and within 30 feet in yellow. These areas are more at risk for flooding and the destructive effects of storm surge and high waves. Data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial

  11. SRTM Perspective View with Landsat Overlay: Santa Barbara, California

    Science.gov (United States)

    2001-01-01

    Santa Barbara, California, is often called 'America's Riviera.' It enjoys a Mediterranean climate, a mountain backdrop, and a long and varied coastline. This perspective view of the Santa Barbara region was generated using data from the Shuttle Radar Topography Mission (SRTM) and an enhanced Landsat satellite image. The view is toward the northeast, from the Goleta Valley in the foreground to a snow-capped Mount Abel (elevation 2526 m or 8286 feet) along the skyline. The coast here generally faces south. Consequently, Fall and Winter sunrises occur over the ocean, which is unusual for the U.S. west coast. The Santa Barbara 'back country' is very rugged and largely remains as undeveloped wilderness and an important watershed for local communities. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface.To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200-feet) long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science Enterprise,Washington, D.C. JPL is a

  12. SRTM Perspective View with Landsat Overlay: Santa Barbara Coastline, California

    Science.gov (United States)

    2001-01-01

    This image of the Santa Barbara, California, region provides a beautiful snapshot of the area's rugged mountains and long and varied coastline. Generated using data acquired from the Shuttle Radar Topography Mission (SRTM) and an enhanced Landsat image this is a perspective view toward the northeast, from the Goleta Valley in the foreground to a snow-capped Mount Abel (elevation 2,526 m or 8,286 feet) along the skyline at the left. On a clear day, a pilot might see a similar view shortly before touching down on the east-west runway of the Santa Barbara Airport, seen just to the left of the coastline near the center of image. This area is one of the few places along the U.S. West Coast where because of a south-facing beach, fall and winter sunrises occur over the ocean.Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter(98-foot) resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.The elevation data used in this image was acquired by SRTM aboard Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science Enterprise

  13. Perspective View with Landsat Overlay, Salt Lake City, Utah

    Science.gov (United States)

    2002-01-01

    Most of the population of Utah lives just west of the Wasatch Mountains in the north central part of the state. This broad east-northeastward view shows that region with the cities of Ogden, Salt Lake City, and Provo seen from left to right. The Great Salt Lake (left) and Utah Lake (right) are quite shallow and appear greenish in this enhanced natural color view. Thousands of years ago ancient Lake Bonneville covered all of the lowlands seen here. Its former shoreline is clearly seen as a wave-cut bench and/or light colored 'bathtub ring' at several places along the base of the mountain front - evidence seen from space of our ever-changing planet.This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM), a Landsat 5 satellite image mosaic, and a false sky. Topographic expression is exaggerated four times.Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif

  14. Advanced overlay: sampling and modeling for optimized run-to-run control

    Science.gov (United States)

    Subramany, Lokesh; Chung, WoongJae; Samudrala, Pavan; Gao, Haiyong; Aung, Nyan; Gomez, Juan Manuel; Gutjahr, Karsten; Park, DongSuk; Snow, Patrick; Garcia-Medina, Miguel; Yap, Lipkong; Demirer, Onur Nihat; Pierson, Bill; Robinson, John C.

    2016-03-01

    In recent years overlay (OVL) control schemes have become more complicated in order to meet the ever shrinking margins of advanced technology nodes. As a result, this brings up new challenges to be addressed for effective run-to- run OVL control. This work addresses two of these challenges by new advanced analysis techniques: (1) sampling optimization for run-to-run control and (2) bias-variance tradeoff in modeling. The first challenge in a high order OVL control strategy is to optimize the number of measurements and the locations on the wafer, so that the "sample plan" of measurements provides high quality information about the OVL signature on the wafer with acceptable metrology throughput. We solve this tradeoff between accuracy and throughput by using a smart sampling scheme which utilizes various design-based and data-based metrics to increase model accuracy and reduce model uncertainty while avoiding wafer to wafer and within wafer measurement noise caused by metrology, scanner or process. This sort of sampling scheme, combined with an advanced field by field extrapolated modeling algorithm helps to maximize model stability and minimize on product overlay (OPO). Second, the use of higher order overlay models means more degrees of freedom, which enables increased capability to correct for complicated overlay signatures, but also increases sensitivity to process or metrology induced noise. This is also known as the bias-variance trade-off. A high order model that minimizes the bias between the modeled and raw overlay signature on a single wafer will also have a higher variation from wafer to wafer or lot to lot, that is unless an advanced modeling approach is used. In this paper, we characterize the bias-variance trade off to find the optimal scheme. The sampling and modeling solutions proposed in this study are validated by advanced process control (APC) simulations to estimate run-to-run performance, lot-to-lot and wafer-to- wafer model term monitoring to

  15. Overlay of conventional angiographic and en-face OCT images enhances their interpretation

    Directory of Open Access Journals (Sweden)

    Pool Chris W

    2005-06-01

    Full Text Available Abstract Background Combining characteristic morphological and functional information in one image increases pathophysiologic understanding as well as diagnostic accuracy in most clinical settings. En-face optical coherence tomography (OCT provides a high resolution, transversal OCT image of the macular area combined with a confocal image of the same area (OCT C-scans. Creating an overlay image of a conventional angiographic image onto an OCT image, using the confocal part to facilitate transformation, combines structural and functional information of the retinal area of interest. This paper describes the construction of such overlay images and their aid in improving the interpretation of OCT C-scans. Methods In various patients, en-face OCT C-scans (made with a prototype OCT-Ophthalmoscope (OTI, Canada in use at the Department of Ophthalmology (Academic Medical Centre, Amsterdam, The Netherlands and conventional fluorescein angiography (FA were performed. ImagePro, with a custom made plug-in, was used to make an overlay-image. The confocal part of the OCT C-scan was used to spatially transform the FA image onto the OCT C-scan, using the vascular arcades as a reference. To facilitate visualization the transformed angiographic image and the OCT C-scan were combined in an RGB image. Results The confocal part of the OCT C-scan could easily be fused with angiographic images. Overlay showed a direct correspondence between retinal thickening and FA leakage in Birdshot retinochoroiditis, localized the subretinal neovascular membrane and correlated anatomic and vascular leakage features in myopia, and showed the extent of retinal and pigment epithelial detachment in retinal angiomatous proliferation as FA leakage was subject to blocked fluorescence. The overlay mode provided additional insight not readily available in either mode alone. Conclusion Combining conventional angiographic images and en-face OCT C-scans assists in the interpretation of both

  16. Sensitivity enhancement of an in-fiber Michelson interferometer evanescent wave sensor using a silver nanoparticle-polymer composite overlay

    Science.gov (United States)

    Sandhu, Sukhpawan S.; Yang, Jian; Xu, C. Q.

    2008-02-01

    Many configurations of fiber optic evanescent wave sensors have recently been explored, with various structural and material modifications applied in attempt to increase their resolution and/or sensitivity. With the aid of long period gratings inscribed within the core of standard single mode fibers, fiber optic evanescent wave sensors with in-fiber interferometric configurations have been realized and have been shown to have excellent resolution due to sharp spectral features. The Michelson interferometer configuration, whereby a single long period grating acts as a beam splitter for the core and cladding modes, is of interest because it operates in reflection mode, which allows for easy signal detection schemes. In this work, it is experimentally demonstrated for the first time that the deposition of a nanoparticle-polymer composite high refractive index overlay film onto the cladding arm surface of such an interferometric sensor greatly increases its sensitivity. Film refractive indices of > 1.7 are achieved and can be further increased to > 2 upon repetition of the nanoparticle synthesis cycle. Sensitivity enhancement factors as large as 16.7 occur in the film index range of 1.9 - 2.1. Experimental data are presented and compared to the theoretical simulation results.

  17. Gigi Tiruan Overlay Thermoplastic Resin Pada Pasien Celah Bibir dan Palatum

    Directory of Open Access Journals (Sweden)

    Elka Ayu Amalia

    2014-12-01

    Full Text Available Kasus celah bibir dan palatum, adalah kasus yang memiliki tingkat kesulitan lebih tinggi dalam hal perbaikan bila dibandingkan dengan kasus kecacatan lain yang disebabkan oleh cacat bawaan maupun dapatan lain. Karena kasus celah bibir dan palatum meminta perhatian khusus pada tahap-tahap perbaikannya, serta memerlukan kolaborasi antar disiplin ilmu kedokteran untuk mendapatkan hasil yang optimal. Prostodonsi adalah salah satu bidang kedokteran gigi yang memegang peranan menentukan hasil akhir dari rangkaian perawatan yang telah dilakukan. Gigi tiruan overlay adalah gigi tiruan lepasan yang digunakan untuk mengurangi penyempitan rahang atas dan perbedaan dalam dimensi vertikal. Tujuan dari artikel ini adalah membahas perawatan yang lebih nyaman dengan gigi tiruan overlay thermoplastic resin untuk kasus celah bibir dan palatum. Seorang pasien perempuan, 25 tahun, datang dengan keluhan ingin perbaikan estetik pada regio anterior rahang atas, untuk menutupi defek sisa hasil operasi penyatuan celah palatum yang telah dilakukan ketika balita. Tatalaksana kasus: 1 Anamnesa, 2 Pemeriksaan klinis dan radiografis, 3 Pencetakan model studi, 4 Pencetakan model kerja, 5 Pemasangan pada artikulator, 6 Penyusunan gigi, 7 Pasang coba model malam, 8 Processing laboratorium, 9 Insersi, 10 Kontrol. Kesimpulan: Perawatan pasien celah palatum dengan gigi tiruan overlay thermoplastic resin memberikan kenyamanan, perbaikan estetis sehingga menimbulkan dampak psikologis yang baik pada pasien.   Thermoplastic Resin Overlay Denture On Cleft Lip And Palate Patient (A Case Report. Background: Cleft lip and palate has a degree of difficulities in habilitativeness among other congenital or acquired handicaps. Because this case requires a special attention on the habilitation stage, also requires an interdiciplinary collaboration in medical professions in order to achieve optimal results. Prosthodontics is a part in dentistry that has a role in determining

  18. Corrosion resistance and microstructure of alloy 625 weld overlay on ASTM A516 grade 70

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Mohammad J. [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Petroleum Engineering Dept.; Ketabchi, Mostafa [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Mining and Metallurgical Engineering Dept.

    2016-02-01

    Nickel-based alloys are a crucial class of materials because of their excellent corrosion resistance. In the present study, single layer and two layers alloy 625 weld overlays were deposited by GTAW process on A516 grade 70 carbon steel. The dilution in terms of Fe, Ni, Mo and Nb content was calculated in 30 points of weld overlay. Microstructure observations showed that alloy 625 had austenitic structure with two types of Laves and NbC secondary phases. The uniform and pitting corrosion resistance of alloy 625 weld overlay as casted and as forged were evaluated in accordance with ASTM G48-2011 standard at different temperatures to determine the weight loss and critical pitting temperature. For achieving a better comparison, samples from alloy 625 as casted and as forged were tested under the same conditions. The results point out that single layer alloy 625 weld overlay is not suitable for chloride containing environments, two layers alloy 625 weld overlay and alloy 625 as casted have acceptable corrosion resistance and almost the same critical pitting temperature. Alloy 625 as forged has the best corrosion resistance and the highest critical pitting temperature among all test specimens. Also, the corrosion behavior was evaluated in accordance with ASTM G28 standard. The corrosion rate of single layer weld overlay was unacceptable. The average corrosion rate of two layers weld overlay and in casted condition were 35.82 and 33.01 mpy, respectively. [German] Nickellegierungen sind aufgrund ihres exzellenten Korrosionswiderstandes eine bedeutende Werkstoffklasse. In der diesem Beitrag zugrunde liegenden Studie wurden mittels WIG-Schweissens ein- und zweilagige Schweissplattierungen auf den Kohlenstoffstahl A516 (Grade 70) aufgebracht. Die Vermischung in Form des Fe-, Ni-, Mo- und Nb-Gehaltes wurde an 30 Punkten der Schweissplattierungen berechnet. Die mikrostrukturellen Untersuchungen ergaben, dass die Legierung 625 eine austenitische Struktur mit zwei Arten von

  19. Mount Ararat, Turkey, Perspective with Landsat Image Overlay

    Science.gov (United States)

    2004-01-01

    (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. View Size: 124 kilometers (77 miles) wide, 148 kilometers (92 miles) distance Location: 39.7 degrees North latitude, 44.3 degrees East longitude Orientation: Looking South, 2 degrees down from horizontal, 1.25X vertical exaggeration Image Data: Landsat Bands 1, 2+4, 3 as blue, green, red respectively Date Acquired: February 2000 (SRTM), August 31, 1989 (Landsat)

  20. Strait of Gibraltar, Perspective with Landsat Image Overlay

    Science.gov (United States)

    2003-01-01

    ) resolution of most Landsat images and will substantially help in analyses of the large Landsat image archive.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.View Size: 46 kilometers (28 miles) wide, 106 kilometers (66 miles) distance Location: 36 degrees North latitude, 5.5 degrees West longitude Orientation: Looking East, 15 degrees down from horizontal, 3X vertical exaggeration Image Data: Landsat Bands 1, 2+4, 3 as blue, green, red respectively Original Data Resolution: 30 meters (99 feet) Date Acquired: February 2000 (SRTM), July 6, 1987 (Landsat)