WorldWideScience

Sample records for textured metal substrates

  1. Highly textured oxypnictide superconducting thin films on metal substrates

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Kazumasa, E-mail: iida@nuap.nagoya-u.ac.jp; Kurth, Fritz; Grinenko, Vadim; Hänisch, Jens [Institute for Metallic Materials, IFW Dresden, D-01171 Dresden (Germany); Chihara, Masashi; Sumiya, Naoki; Hatano, Takafumi; Ikuta, Hiroshi [Department of Crystalline Materials Science, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Ichinose, Ataru; Tsukada, Ichiro [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Matias, Vladimir [iBeam Materials, Inc., 2778A Agua Fria Street, Santa Fe, New Mexico 87507 (United States); Holzapfel, Bernhard [Institute for Technical Physics, Karlsruhe Institute of Technology, Hermann von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2014-10-27

    Highly textured NdFeAs(O,F) thin films have been grown on ion beam assisted deposition-MgO/Y{sub 2}O{sub 3}/Hastelloy substrates by molecular beam epitaxy. The oxypnictide coated conductors showed a superconducting transition temperature (T{sub c}) of 43 K with a self-field critical current density (J{sub c}) of 7.0×10{sup 4} A/cm{sup 2} at 5 K, more than 20 times higher than powder-in-tube processed SmFeAs(O,F) wires. Albeit higher T{sub c} as well as better crystalline quality than Co-doped BaFe{sub 2}As{sub 2} coated conductors, in-field J{sub c} of NdFeAs(O,F) was lower than that of Co-doped BaFe{sub 2}As{sub 2}. These results suggest that grain boundaries in oxypnictides reduce J{sub c} significantly compared to that in Co-doped BaFe{sub 2}As{sub 2} and, hence biaxial texture is necessary for high J{sub c.}.

  2. Cube-textured metal substrates for reel-to-reel processing of coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian

    This thesis presents the results of a study aimed at investigating important fabrication aspects of reel-to-reel processing of metal substrates for coated conductors and identifying a new substrate candidate material with improved magnetic properties. The eect of mechanical polishing on surface r...... texture and the fraction of low angle grain boundaries. Finally, a Ni-5Cu-5W substrate may be a good candidate material as a substrate in future coated conductors....

  3. Conductive and robust nitride buffer layers on biaxially textured substrates

    Science.gov (United States)

    Sankar, Sambasivan [Chicago, IL; Goyal, Amit [Knoxville, TN; Barnett, Scott A [Evanston, IL; Kim, Ilwon [Skokie, IL; Kroeger, Donald M [Knoxville, TN

    2009-03-31

    The present invention relates to epitaxial, electrically conducting and mechanically robust, cubic nitride buffer layers deposited epitaxially on biaxially textured substrates such as metals and alloys. The invention comprises of a biaxially textured substrate with epitaxial layers of nitrides. The invention also discloses a method to form such epitaxial layers using a high rate deposition method as well as without the use of forming gases. The invention further comprises epitaxial layers of oxides on the biaxially textured nitride layer. In some embodiments the article further comprises electromagnetic devices which may have superconducting properties.

  4. Epitaxial hexagonal materials on IBAD-textured substrates

    Science.gov (United States)

    Matias, Vladimir; Yung, Christopher

    2017-08-15

    A multilayer structure including a hexagonal epitaxial layer, such as GaN or other group III-nitride (III-N) semiconductors, a oriented textured layer, and a non-single crystal substrate, and methods for making the same. The textured layer has a crystalline alignment preferably formed by the ion-beam assisted deposition (IBAD) texturing process and can be biaxially aligned. The in-plane crystalline texture of the textured layer is sufficiently low to allow growth of high quality hexagonal material, but can still be significantly greater than the required in-plane crystalline texture of the hexagonal material. The IBAD process enables low-cost, large-area, flexible metal foil substrates to be used as potential alternatives to single-crystal sapphire and silicon for manufacture of electronic devices, enabling scaled-up roll-to-roll, sheet-to-sheet, or similar fabrication processes to be used. The user is able to choose a substrate for its mechanical and thermal properties, such as how well its coefficient of thermal expansion matches that of the hexagonal epitaxial layer, while choosing a textured layer that more closely lattice matches that layer.

  5. Development and application of a green-chemistry solution deposition technique for buffer layer coating on cube-textured metal substrates in view of further deposition of rare-earth based superconductors

    DEFF Research Database (Denmark)

    Pallewatta, Pallewatta G A P

    which consist of YBCO superconducting coatings on cube-textured Ni based alloy tapes.  Before the epitaxial deposition this superconducting layer, a buffer layer is applied on the metal substrate as a diffusion barrier which is also required to transfer the strong texture of the underlying substrate......, allowing the epitaxial growth of the superconducting layer. State-of-the-art coated conductor hetero structures are mainly based on CeO2 based buffer stacks that consist of a sequence of several different buffer layers. Buffer layers deposited by continuous chemical deposition techniques, which...... are the most suitable for large scale production, use to suffer from porosity and cracks that lead to material diffusion from the metal substrate into the superconductor as well as oxidation of the metal during high-temperature processing of the buffer layer. SrTiO3 buffer layers have attracted interest due...

  6. Highly textured Gd2Zr2O7 films grown on textured Ni-5 at.%W substrates by solution deposition route: Growth, texture evolution, and microstructure dependency

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; Napari, M.

    2012-01-01

    or crystallization in the thicker films. This work not only demonstrates a route for producing textured Gd2Zr2O7 buffer layers with dense structure directly on technical substrates, but also provides some fundamental understandings related to chemical solution derived films grown on metallic substrates.......Growth, texture evolution and microstructure dependency of solution derived Gd2Zr2O7 films deposited on textured Ni-5 at.%W substrates have been extensively studied. Influence of processing parameters, in particular annealing temperature and dwell time, as well as thickness effect on film texture...... the difference of interfacial energy along two directions in the anisotropic metallic substrate. Growth of Gd2Zr2O7 films displays an ultrafast kinetics under optimized conditions. Independency of sharp epitaxial (004) and polycrystalline (222) orientation is revealed from further synchrotron diffraction studies...

  7. Composite biaxially textured substrates using ultrasonic consolidation

    Science.gov (United States)

    Blue, Craig A; Goyal, Amit

    2013-04-23

    A method of forming a composite sheet includes disposing an untextured metal or alloy first sheet in contact with a second sheet in an aligned opposing position; bonding the first sheet to the second sheet by applying an oscillating ultrasonic force to at least one of the first sheet and the second sheet to form an untextured intermediate composite sheet; and annealing the untextured intermediate composite sheet at a temperature lower than a primary re-crystallization temperature of the second sheet and higher than a primary re-crystallization temperature of the first sheet to convert the untextured first sheet into a cube textured sheet, wherein the cube texture is characterized by a .phi.-scan having a FWHM of no more than 15.degree. in all directions, the second sheet remaining untextured, to form a composite sheet.

  8. Fabrication of a Textured Non-Magnetic Ni-12at.%V Alloy Substrate for Coated Conductors

    DEFF Research Database (Denmark)

    Gao, M. M.; Grivel, Jean-Claude; Suo, H. L.

    2011-01-01

    Ni-12at.%V alloy is a promising candidate for non-magnetic cube textured metallic substrates used for high temperature coated conductors. In this work, a textured Ni-12at.%V substrate has been fabricated by powder metallurgy route. After cold rolling and recrystallization annealing, a cube texture...

  9. Effects of surface relief on the texture formation of melt-solidified YBa 2Cu 3O z thick films on metal substrates

    Science.gov (United States)

    Goodilin, E. A.; Reddy, E. S.; Noudem, J. G.; Tarka, M.; Schmitz, G. J.

    2002-08-01

    Biaxial orientation of up to 75-85% of YBa 2Cu 3O z square crystals of 0.1-1 mm size was achieved on polycrystalline Ag-Pd substrates with artificial surface reliefs by adopting the principles of artificial epitaxy and a shape-preserving low-temperature infiltration process. Unlike artificial epitaxy for thin films, the crystal alignment was attained reproducibly by mechanical patterning of the substrates at a large, millimeter length-scale. Texture formation might be related to various factors like solute redistribution in a multicomponent system, capillarity, crystallization pressure and wall effects. Possible applications of this approach for coated conductors or in the field of multiseeded substrates are discussed.

  10. Method of Forming Textured Silicon Substrate by Maskless Cryogenic Etching

    Science.gov (United States)

    Yee, Karl Y. (Inventor); Homyk, Andrew P. (Inventor)

    2014-01-01

    Disclosed herein is a textured substrate comprising a base comprising silicon, the base having a plurality of needle like structures depending away from the base, wherein at least one of the needle like structures has a depth of greater than or equal to about 50 micrometers determined perpendicular to the base, and wherein at least one of the needle like structures has a width of less than or equal to about 50 micrometers determined parallel to the base. An anode and a lithium ion battery comprising the textured substrate, and a method of producing the textured substrate are also disclosed.

  11. Crystallographic Texture in Ceramics and Metals.

    Science.gov (United States)

    Vaudin, M D

    2001-01-01

    Preferred crystallographic orientation, or texture, occurs almost universally, both in natural and man-made systems. Many components and devices in electronic and magnetic systems are fabricated from materials that have crystallographic texture. With the rapidly increasing use of thin film technology, where sharp axisymmetric crystallographic texture normal to the film plane is frequently observed, the occurrence and impact of texture are rising. Thin film applications in which the texture of the material plays a key role in determining properties and performance are broad: complex oxides in random access memory devices, ZnO thin film resonators for cell phone applications, metallic alloys in magnetic recording media, and Al and Cu interconnects in integrated circuits are but a few examples. Texture is established during the synthesis or post-synthesis heat treatment of a material and thus has a strong dependence upon processing history. Accurate measurement of texture is not simple and a variety of tools and approaches are being actively employed in texture studies. X-ray, neutron and electron diffraction based techniques are practiced around the world at varying levels of complexity with regard to equipment and analysis methods. Despite the well-documented existence of these varied approaches, many reported texture measurements on electronic materials are based solely on the relative intensities of conventional θ-2θ x-ray diffraction peaks, which typically yield inaccurate results. NIST has developed quantitative texture measurement techniques that employ equipment commonly available in most industrial and academic settings. A number of examples of texture measurement in ceramic and metal systems will be presented, taken from the historical development and application of these techniques at NIST over the past 7 years.

  12. Texture and wettability of metallic lotus leaves

    Science.gov (United States)

    Frankiewicz, C.; Attinger, D.

    2016-02-01

    Superhydrophobic surfaces with the self-cleaning behavior of lotus leaves are sought for drag reduction and phase change heat transfer applications. These superrepellent surfaces have traditionally been fabricated by random or deterministic texturing of a hydrophobic material. Recently, superrepellent surfaces have also been made from hydrophilic materials, by deterministic texturing using photolithography, without low-surface energy coating. Here, we show that hydrophilic materials can also be made superrepellent to water by chemical texturing, a stochastic rather than deterministic process. These metallic surfaces are the first analog of lotus leaves, in terms of wettability, texture and repellency. A mechanistic model is also proposed to describe the influence of multiple tiers of roughness on wettability and repellency. This demonstrated ability to make hydrophilic materials superrepellent without deterministic structuring or additional coatings opens the way to large scale and robust manufacturing of superrepellent surfaces.Superhydrophobic surfaces with the self-cleaning behavior of lotus leaves are sought for drag reduction and phase change heat transfer applications. These superrepellent surfaces have traditionally been fabricated by random or deterministic texturing of a hydrophobic material. Recently, superrepellent surfaces have also been made from hydrophilic materials, by deterministic texturing using photolithography, without low-surface energy coating. Here, we show that hydrophilic materials can also be made superrepellent to water by chemical texturing, a stochastic rather than deterministic process. These metallic surfaces are the first analog of lotus leaves, in terms of wettability, texture and repellency. A mechanistic model is also proposed to describe the influence of multiple tiers of roughness on wettability and repellency. This demonstrated ability to make hydrophilic materials superrepellent without deterministic structuring or additional

  13. Fourier optics for polymeric substrates and coating textures analysis

    OpenAIRE

    Sparavigna, Amelia; Wolf, Rory A.

    2008-01-01

    Several devices for substrate texture detection based on diffractive optics, for paper, textiles and non-wovens have been proposed in the past for direct inspection during the production processes. In spite of the presence of devices totally based on image processing, the use of diffractive optics cannot be considered surpassed for many reasons. Compared with image processing procedures, it is less sensitive to vibrations and does not suffer from the presence of ambient light. Based on transm...

  14. The neural substrate for working memory of tactile surface texture.

    Science.gov (United States)

    Kaas, Amanda L; van Mier, Hanneke; Visser, Maya; Goebel, Rainer

    2013-05-01

    Fine surface texture is best discriminated by touch, in contrast to macro geometric features like shape. We used functional magnetic resonance imaging and a delayed match-to-sample task to investigate the neural substrate for working memory of tactile surface texture. Blindfolded right-handed males encoded the texture or location of up to four sandpaper stimuli using the dominant or non-dominant hand. They maintained the information for 10-12 s and then answered whether a probe stimulus matched the memory array. Analyses of variance with the factors Hand, Task, and Load were performed on the estimated percent signal change for the encoding and delay phase. During encoding, contralateral effects of Hand were found in sensorimotor regions, whereas Load effects were observed in bilateral postcentral sulcus (BA2), secondary somatosensory cortex (S2), pre-SMA, dorsolateral prefrontal cortex (dlPFC), and superior parietal lobule (SPL). During encoding and delay, Task effects (texture > location) were found in central sulcus, S2, pre-SMA, dlPFC, and SPL. The Task and Load effects found in hand- and modality-specific regions BA2 and S2 indicate involvement of these regions in the tactile encoding and maintenance of fine surface textures. Similar effects in hand- and modality-unspecific areas dlPFC, pre-SMA and SPL suggest that these regions contribute to the cognitive monitoring required to encode and maintain multiple items. Our findings stress both the particular importance of S2 for the encoding and maintenance of tactile surface texture, as well as the supramodal nature of parieto-frontal networks involved in cognitive control. Copyright © 2012 Wiley Periodicals, Inc.

  15. Carbon Nanotube Patterning on a Metal Substrate

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor)

    2016-01-01

    A CNT electron source, a method of manufacturing a CNT electron source, and a solar cell utilizing a CNT patterned sculptured substrate are disclosed. Embodiments utilize a metal substrate which enables CNTs to be grown directly from the substrate. An inhibitor may be applied to the metal substrate to inhibit growth of CNTs from the metal substrate. The inhibitor may be precisely applied to the metal substrate in any pattern, thereby enabling the positioning of the CNT groupings to be more precisely controlled. The surface roughness of the metal substrate may be varied to control the density of the CNTs within each CNT grouping. Further, an absorber layer and an acceptor layer may be applied to the CNT electron source to form a solar cell, where a voltage potential may be generated between the acceptor layer and the metal substrate in response to sunlight exposure.

  16. Fabrication of the Textured Ni-9.3at.%W Alloy Substrate for Coated Conductors

    DEFF Research Database (Denmark)

    Gao, M. M.; Suo, H. L.; Grivel, Jean-Claude

    2011-01-01

    It is difficult to obtain a sharp cube texture in the Ni-9.3at.% W substrate used for coated conductors due to its low stacking fault energy. In this paper, the traditional cold rolling procedure was optimized by introducing an intermediate recovery annealing. The deformation texture has been imp...

  17. Metal oxide nanorod arrays on monolithic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Pu-Xian; Guo, Yanbing; Ren, Zheng

    2018-01-02

    A metal oxide nanorod array structure according to embodiments disclosed herein includes a monolithic substrate having a surface and multiple channels, an interface layer bonded to the surface of the substrate, and a metal oxide nanorod array coupled to the substrate surface via the interface layer. The metal oxide can include ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide. The substrate can include a glass substrate, a plastic substrate, a silicon substrate, a ceramic monolith, and a stainless steel monolith. The ceramic can include cordierite, alumina, tin oxide, and titania. The nanorod array structure can include a perovskite shell, such as a lanthanum-based transition metal oxide, or a metal oxide shell, such as ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide, or a coating of metal particles, such as platinum, gold, palladium, rhodium, and ruthenium, over each metal oxide nanorod. Structures can be bonded to the surface of a substrate and resist erosion if exposed to high velocity flow rates.

  18. Epitaxial YBa2Cu3O7 films on rolled-textured metals for high temperature superconducting applications

    International Nuclear Information System (INIS)

    Norton, D.P.; Park, C.; Prouteau, C.

    1998-04-01

    The epitaxial growth of high temperature superconducting (HTS) films on rolled-textured metal represents a viable approach for long-length superconducting tapes. Epitaxial, 0.5 microm thick YBa 2 Cu 3 O 7 (YBCO) films with critical current densities, J c , greater than 1 MA/cm 2 have been realized on rolled-textured (001) Ni tapes with yttria-stabilized zirconia (YSZ)/CeO 2 oxide buffer layers. This paper describes the synthesis using pulsed-laser deposition (PLD) of epitaxial oxide buffer layers on biaxially-textured metal that comprise the so-called rolling-assisted biaxially-textured substrates (RABiTs trademark). The properties of the buffer and YBa 2 Cu 3 O 7 films on rolled-textured Ni are discussed, with emphasis given to the crystallographic and microstructural properties that determine the superconducting properties of these multilayer structures

  19. Laser textured substrates for light in-coupling in thin-film solar cells

    Science.gov (United States)

    Chakanga, Kambulakwao; Siepmann, Ortwin; Sergeev, Oleg; Geißendörfer, Stefan; von Maydell, Karsten; Agert, Carsten

    2014-03-01

    In this work we investigate the use of a picosecond (ps) laser used for monolithic connection to pattern glass substrates to achieve light in-coupling in silicon thin film solar cells. We present our results on the patterning of three commercially available and frequently used multi-component glasses Corning EAGLE XG®, Schott BOROFLOAT® 33 and Saint-Gobain SGG DIAMANT®. We find that the different glass structural components influence the degree of texturing obtained. This can be attributed to the different laser induced electron collision times and recombination rates, and thus the critical electron density evolution leading to ablation. Thus the ablated crater profile is glass composition dependent. The surface texture is altered from periodic to random with decreasing scribing speed. The transmission of the textured substrates gradually decreases while the reflection increases as a consequence of the topological and morphological changes. The angular resolved measurements illustrate that highly textured substrates scatter the light towards greater angles. This demonstrates potential for the application in substrate configuration (nip) thin film solar cells, as the scattering can increase the optical path, and hence the absorption in the absorber layer. Simulations of periodically textured glass substrates demonstrate a focused optical generation rate near the front contact and absorber layer interface. The influence of the modified refractive index region on the optical generation rate and reflection depends on the crater profile. The reflection is generally reduced when a periodic texture in the micrometre range is implemented.

  20. Adhesion of rhodium films on metallic substrates

    International Nuclear Information System (INIS)

    Marot, L.; Covarel, G.; Tuilier, M.-H.; Steiner, R.; Oelhafen, P.

    2008-01-01

    Rhodium coated metallic films were prepared by magnetron sputtering on metallic substrates. All films were elaborated in same conditions on copper, molybdenum and stainless steel. Adhesion strength tests were carried out by scratch test. The results reveal that the adhesion strength between the film and the substrate is influenced by the hardness of the substrate. Increase of deposition temperature improves the adhesion of the coating. In addition, pre-treatment of substrates by a filtered cathodic vacuum arc and the layer thickness have has some effects on the final adhesion strength

  1. Textural and morphological studies of transition metal doped SBA ...

    Indian Academy of Sciences (India)

    rials with short and open channels are well explored because they are more ..... is important to note that the increase in unit cell con- stant, ao is not .... The strik- ing improvement in textural parameters suggests that the metal salts promote the silica condensation as a result possesses thicker pore walls. 3.3 TG Analysis.

  2. Development of cube textured Ni-W alloy substrates used for coated conductors

    DEFF Research Database (Denmark)

    Suo, Hongli; Ma, Lin; Gao, Mangmang

    2014-01-01

    It is considered as a challenge for RABiTS route to get cube textured Ni-W alloy substrates with high mechanical and magnetic properties for coated conductors. The works of our group in recent years are summarized about different Ni-W substrates with high W content and composite tapes made by RABi...

  3. Interpretation of quantitative crystallographic texture in copper electrodeposits on amorphous substrates

    DEFF Research Database (Denmark)

    Pantleon, Karen; Jensen, Jens Arne Dahl; Somers, Marcel A. J.

    2004-01-01

    Crystallographic texture and morphology in Cu electrodeposits was studied in relation to the current density and the content of the organic levelling additive 3-mercapto-1-propanesulfonate. The substrate onto which Cu was electrodeposited consisted of amorphous Ni-P in order to allow substrate...

  4. Rare earth zirconium oxide buffer layers on metal substrates

    Science.gov (United States)

    Williams, Robert K.; Paranthaman, Mariappan; Chirayil, Thomas G.; Lee, Dominic F.; Goyal, Amit; Feenstra, Roeland

    2001-01-01

    A laminate article comprises a substrate and a biaxially textured (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer over the substrate, wherein 0layer can be deposited using sol-gel or metal-organic decomposition. The laminate article can include a layer of YBCO over the (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer. A layer of CeO.sub.2 between the YBCO layer and the (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer can also be include. Further included can be a layer of YSZ between the CeO.sub.2 layer and the (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer. The substrate can be a biaxially textured metal, such as nickel. A method of forming the laminate article is also disclosed.

  5. Control of texture in Ag and Ag-alloy substrates for superconducting tapes

    International Nuclear Information System (INIS)

    Gladstone, T.A.

    2000-01-01

    The use of a biaxially textured silver tape as a substrate for high temperature superconductor (HTS) phases is one possible route towards the fabrication of high-J c superconducting tape. Using a cold-rolling and annealing process we have reproducibly fabricated {110} textured silver which is stable up to 900 deg. C. We have found that there are two critical process requirements for the formation of this texture; a low oxygen content in the material prior to deformation, and a cold-rolling thickness reduction of less than 97%. To overcome the problems associated with the poor mechanical strength of pure silver, texture development in Ag-Mg and Ag-Hf alloys with improved mechanical properties has been studied. Heat treatments in a reducing atmosphere allow the {110} annealing texture to be obtained in Ag-0.1 wt%Mg. The recrystallization behaviour of a Ag-Pd alloy with an increased stacking fault energy was also investigated and a partial cube texture was obtained in this material. Using orientation distribution function (ODF) analysis we have shown that minor variations in the deformation texture of both pure silver and Ag-based alloys can lead to significant differences in the recrystallization textures obtained. (author)

  6. Control of texture in Ag and Ag-alloy substrates for superconducting tapes

    Science.gov (United States)

    Gladstone, T. A.; Moore, J. C.; Henry, B. M.; Speller, S.; Salter, C. J.; Wilkinson, A. J.; Grovenor, C. R. M.

    2000-09-01

    The use of a biaxially textured silver tape as a substrate for high temperature superconductor (HTS) phases is one possible route towards the fabrication of high-Jc superconducting tape. Using a cold-rolling and annealing process we have reproducibly fabricated {110} textured silver which is stable up to 900 °C. We have found that there are two critical process requirements for the formation of this texture; a low oxygen content in the material prior to deformation, and a cold-rolling thickness reduction of less than 97%. To overcome the problems associated with the poor mechanical strength of pure silver, texture development in Ag-Mg and Ag-Hf alloys with improved mechanical properties has been studied. Heat treatments in a reducing atmosphere allow the {110} annealing texture to be obtained in Ag-0.1 wt%Mg. The recrystallization behaviour of a Ag-Pd alloy with an increased stacking fault energy was also investigated and a partial cube texture was obtained in this material. Using orientation distribution function (ODF) analysis we have shown that minor variations in the deformation texture of both pure silver and Ag-based alloys can lead to significant differences in the recrystallization textures obtained.

  7. Neurite development in PC12 cells on flexible micro-textured substrates under cyclic stretch.

    Science.gov (United States)

    Haq, Furqan; Keith, Charles; Zhang, Guigen

    2006-01-01

    We investigated the combined effect of micro-texture and mechanical strain on neuronal cell development such as neurite length and neurite density in a rat pheochromocytoma cell line (PC12 cells). Cells were seeded on flexible silicone substrates with micro-texture or no texture (smooth) and cultured under static and dynamic conditions. In the static condition substrates were not stretched and in the dynamic conditions substrates were subjected to cyclic uniaxial stretching at three different strain levels of 4%, 8%, and 16% with each at three different strain rates at 0.1, 0.5, and 1.0 Hz. Results showed that of all cell cultures there was no significant difference in neurite development between cells on smooth and textured substrates, except in the static and 4% at 0.1 Hz conditions, where micro-texture induced significantly longer neurites. With both types of substrates, a lower mechanical condition (4% at 1.0 Hz or 16% at 0.1 Hz) resulted in more and longer neurites and lower cell density, and a higher mechanical condition (16% at 1.0 Hz) resulted in fewer and shorter neurites and lower cell density as compared to the static condition. These findings suggest that the effect of the micro-texture on neurite development is more prominent in low mechanical conditions than in high mechanical conditions and that the strain level and strain rate have an interrelated effect on neurite development: a higher strain level at a lower strain rate has a similar effect as a lower strain level at a higher strain rate in terms of promoting neurite development.

  8. Enhancement of low pressure cold sprayed copper coating adhesion by laser texturing on aluminum substrates

    Science.gov (United States)

    Knapp, Wolfgang; Gillet, Vincent; Courant, Bruno; Aubignat, Emilie; Costil, Sophie; Langlade, Cécile

    2017-02-01

    Surface pre-treatment is fundamental in thermal spraying processes to obtain a sufficient bonding strength between substrate and coating. Different pre-treatments can be used, mostly grit-blasting for current industrial applications. This study is focused on Cu-Al2O3 coatings obtained by Low Pressure Cold Spray on AW5083 aluminum alloy substrate. Bonding strength is measured by tensile adhesion test, while deposition efficiency is measured. Substrates are textured by laser, using a pattern of equally spaced grooves with almost constant diameter and variations of depth. Results show that bonding strength is improved up to +81% compared to non-treated substrate, while deposition efficiency remains constant. The study of the samples after rupture reveals a modification of the failure mode, from mixed failure to cohesive failure. A modification of crack propagation is also noticed, the shape of laser textured grooves induces a deviation of cracks inside the coating instead of following the interface between the layers.

  9. Development of cube textured Ni-5 at.%W alloy substrates for coated conductor application using a melting process

    International Nuclear Information System (INIS)

    Zhao Yue; Suo Hongli; Liu Min; Liu Danmin; Zhang Yingxiao; Zhou Meiling

    2006-01-01

    Biaxially textured Ni-5 at.%W substrates have been prepared by cold rolling, followed by three different annealing routes. In this paper, the processes of melting Ni and W metals, flat rolling, various annealing methods are described in detail. The Ni-5 at.%W tapes annealed under either high vacuum or flowing Ar (7% H 2 ) gas were characterized by X-ray pole figures, ODF, EBSD as well as AFM analysis. The texture analysis indicated that as fabricated tapes have a sharp cube texture formed after annealing at a wide temperature range of 800-1100 o C. The high quality of cube orientation on tapes was obtained after a two-step annealing (TSA), where the percentage of the cube texture component was as high as 93.5% within a misorientation angle smaller than 8 o from EBSD analysis. Furthermore, it was also observed that the number of twin boundaries in this tape decreased with respect to that of tapes annealed both in vacuum and one-step gas annealing. From AFM on 1 μm 2 areas, it was concluded that the roughness (RMS) on the tape surface reached 0.98 nm

  10. Effect of substrate on texture and mechanical properties of Mg-Cu-Zn thin films

    Science.gov (United States)

    Eshaghi, F.; Zolanvari, A.

    2018-04-01

    In this work, thin films of Mg-Cu-Zn with 60 nm thicknesses have been deposited on the Si(100), Al, stainless steel, and Cu substrates using DC magnetron sputtering. FESEM images displayed uniformity of Mg-Cu-Zn particles on the different substrates. AFM micrograph revealed the roughness of thin film changes due to the different kinds of the substrates. XRD measurements showed the existence of strong Mg (002) reflections and weak Mg (101) peaks. Residual stress and adhesion force have been measured as the mechanical properties of the Mg-Cu-Zn thin films. The residual stresses of thin films which have been investigated by X-ray diffraction method revealed that the thin films sputtered on the Si and Cu substrates endure minimum and maximum stresses, respectively, during the deposition process. However, the force spectroscopy analysis indicated that the films grew on the Si and Cu experienced maximum and minimum adhesion force. The texture analysis has been done using XRD instrument to make pole figures of Mg (002) and Mg (101) reflections. ODFs have been calculated to evaluate the distribution of the orientations within the thin films. It was found that the texture and stress have an inverse relation, while the texture and the adhesion force of the Mg-Cu-Zn thin films have direct relation. A thin film that sustains the lowest residual stresses and highest adhesive force had the strongest {001} basal fiber texture.

  11. Microstructure, texture and magnetic properties of Ni-Cu-W substrates for coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Mishin, Oleg; Andersen, Niels Hessel

    2013-01-01

    concentrations of copper, increasing the Cu-content to 10 at% and 15 at% leads to increased frequencies of annealing twins in the cube-textured matrix. It is suggested that the (Ni 95W5)100-xCux alloy with x=5 at% Cu may be a good candidate material for using as a substrate for coated conductors. © 2012 Elsevier...

  12. Evolution of microstructure, texture and topography during additional annealing of cube-textured Ni–5at.%W substrate for coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Mishin, Oleg; Grivel, Jean-Claude

    2012-01-01

    Microstructure, texture and topography have been studied in a recrystallized Ni–5at.%W substrate before and after additional annealing at 1025C for 1 h. The initial recrystallized material contained a strong cube texture and a high fraction of low angle grain boundaries. R3 boundaries were also f...

  13. Study on the formation of cubic texture in Ni-7 at.% W alloy substrates by powder metallurgy routes

    DEFF Research Database (Denmark)

    Zhao, Yue; Suo, HongLi; Zhu, YongHua

    2009-01-01

    One of the main challenges for coated conductor applications is to produce sharp cubic textured alloy substrates with high strength and low magnetism. In this work, the cubic textured Ni–7 at.% W substrates were prepared from different powder metallurgy ingots by rolling-assisted biaxially textured...... substrate processing. The fabrication processes of cubic texture in the Ni–7 at.% W tapes by two powder metallurgy routes are described in detail. Through the optimized process, full width at half maximum values of 6.7° and 5.0° were obtained, as estimated by X-ray (1 1 1) phi scan and (2 0 0) rocking curve...

  14. Common Dorsal Stream Substrates for the Mapping of Surface Texture to Object Parts and Visual Spatial Processing.

    Science.gov (United States)

    Zachariou, Valentinos; Nikas, Christine V; Safiullah, Zaid N; Behrmann, Marlene; Klatzky, Roberta; Ungerleider, Leslie G

    2015-12-01

    Everyday objects are often composed of multiple parts, each with a unique surface texture. The neural substrates mediating the integration of surface features on different object parts are not fully understood, and potential contributions by both the ventral and dorsal visual pathways are possible. To explore these substrates, we collected fMRI data while human participants performed a difference detection task on two objects with textured parts. The objects could either differ in the assignment of the same texture to different object parts ("texture-location") or the types of texture ("texture-type"). In the ventral stream, comparable BOLD activation levels were observed in response to texture-location and texture-type differences. In contrast, in a priori localized spatial processing regions of the dorsal stream, activation was greater for texture-location than texture-type differences, and the magnitude of the activation correlated with behavioral performance. We confirmed the reliance of surface texture to object part mapping on spatial processing mechanisms in subsequent psychophysical experiments, in which participants detected a difference in the spatial distance of an object relative to a reference line. In this task, distracter objects occasionally appeared, which differed in either texture-location or texture-type. Distracter texture-location differences slowed detection of spatial distance differences, but texture-type differences did not. More importantly, the distracter effects were only observed when texture-location differences were presented within whole shapes and not between separated shape parts at distinct spatial locations. We conclude that both the mapping of texture features to object parts and the representation of object spatial position are mediated by common neural substrates within the dorsal visual pathway.

  15. Formation of biaxial texture in metal films by selective ion beam etching

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J. [Department of Materials Science and Engineering, University of Florida, 106 Rhines Hall, P.O. Box 116400, Gainesville, FL 32611 (United States); Norton, D.P. [Department of Materials Science and Engineering, University of Florida, 106 Rhines Hall, P.O. Box 116400, Gainesville, FL 32611 (United States)]. E-mail: dnort@mse.ufl.edu; Selvamanickam, Venkat [IGC-SuperPower, LLC, 450 Duane Avenue, Schenectady, NY 12304 (United States)

    2006-05-15

    The formation of in-plane texture via ion bombardment of uniaxially textured metal films was investigated. In particular, selective grain Ar ion beam etching of uniaxially textured (0 0 1) Ni was used to achieve in-plane aligned Ni grains. Unlike conventional ion beam assisted deposition, the ion beam irradiates the uniaxially textured film surface with no impinging deposition flux. The initial uniaxial texture is established via surface energy minimization with no ion irradiation. Within this sequential texturing method, in-plane grain alignment is driven by selective etching and grain overgrowth. Biaxial texture was achieved for ion beam irradiation at elevated temperature.

  16. Formation of biaxial texture in metal films by selective ion beam etching

    International Nuclear Information System (INIS)

    Park, S.J.; Norton, D.P.; Selvamanickam, Venkat

    2006-01-01

    The formation of in-plane texture via ion bombardment of uniaxially textured metal films was investigated. In particular, selective grain Ar ion beam etching of uniaxially textured (0 0 1) Ni was used to achieve in-plane aligned Ni grains. Unlike conventional ion beam assisted deposition, the ion beam irradiates the uniaxially textured film surface with no impinging deposition flux. The initial uniaxial texture is established via surface energy minimization with no ion irradiation. Within this sequential texturing method, in-plane grain alignment is driven by selective etching and grain overgrowth. Biaxial texture was achieved for ion beam irradiation at elevated temperature

  17. Crystallographic texture analysis of archaeological metals: interpretation of manufacturing techniques

    International Nuclear Information System (INIS)

    Artioli, G.

    2007-01-01

    Neutron probes and high energy X-rays are sources of primary importance for the non-invasive characterization of materials related to cultural heritage. Their employment in the characterization of archaeological metal objects, combined with the recent instrumental and computational developments in the field of crystallographic texture analysis (CTA) from diffraction data proves to be a powerful tool for the interpretation of ancient metal working techniques. Diffraction based CTA, when performed using penetrating probes and adequate detector coverage of reciprocal space, for example using large detector arrays and/or ToF mode, allows simultaneous identification and quantification of crystalline phases, besides the microstructural and textural characterization of the object, and it can be effectively used as a totally non-invasive tool for metallographic analysis. Furthermore, the chemical composition of the object may also be obtained by the simultaneous detection of prompt gamma rays induced by neutron activation, or by the fluorescence signal from high energy X-rays, in order to obtain a large amount of complementary information in a single experiment. The specific application of neutron CTA to the characterization of the manufacturing processes of prehistoric copper axes is discussed in detail. (orig.)

  18. Crystallographic texture analysis of archaeological metals: interpretation of manufacturing techniques

    Science.gov (United States)

    Artioli, G.

    2007-12-01

    Neutron probes and high energy X-rays are sources of primary importance for the non-invasive characterization of materials related to cultural heritage. Their employment in the characterization of archaeological metal objects, combined with the recent instrumental and computational developments in the field of crystallographic texture analysis (CTA) from diffraction data proves to be a powerful tool for the interpretation of ancient metal working techniques. Diffraction based CTA, when performed using penetrating probes and adequate detector coverage of reciprocal space, for example using large detector arrays and/or ToF mode, allows simultaneous identification and quantification of crystalline phases, besides the microstructural and textural characterization of the object, and it can be effectively used as a totally non-invasive tool for metallographic analysis. Furthermore, the chemical composition of the object may also be obtained by the simultaneous detection of prompt gamma rays induced by neutron activation, or by the fluorescence signal from high energy X-rays, in order to obtain a large amount of complementary information in a single experiment. The specific application of neutron CTA to the characterization of the manufacturing processes of prehistoric copper axes is discussed in detail.

  19. Alluvial substrate mapping by automated texture segmentation of recreational-grade side scan sonar imagery.

    Science.gov (United States)

    Hamill, Daniel; Buscombe, Daniel; Wheaton, Joseph M

    2018-01-01

    Side scan sonar in low-cost 'fishfinder' systems has become popular in aquatic ecology and sedimentology for imaging submerged riverbed sediment at coverages and resolutions sufficient to relate bed texture to grain-size. Traditional methods to map bed texture (i.e. physical samples) are relatively high-cost and low spatial coverage compared to sonar, which can continuously image several kilometers of channel in a few hours. Towards a goal of automating the classification of bed habitat features, we investigate relationships between substrates and statistical descriptors of bed textures in side scan sonar echograms of alluvial deposits. We develop a method for automated segmentation of bed textures into between two to five grain-size classes. Second-order texture statistics are used in conjunction with a Gaussian Mixture Model to classify the heterogeneous bed into small homogeneous patches of sand, gravel, and boulders with an average accuracy of 80%, 49%, and 61%, respectively. Reach-averaged proportions of these sediment types were within 3% compared to similar maps derived from multibeam sonar.

  20. Improvement of IBAD-MgO texturing for high throughput of buffered substrate

    International Nuclear Information System (INIS)

    Ito, T.; Takahashi, Y.; Matsuse, K.; Kuriki, R.; Tokumaru, M.; Yoshizumi, M.; Izumi, T.

    2011-01-01

    The requirements from the market on two important factors of performance and cost need to be satisfied for commercialization of the coated conductors. Highly biaxially grain texturing with high production rate should be realized from the perspective of buffer layers processing. IBAD-MgO process is one of the major techniques which are possible to satisfy those requirements. The structure of our buffered substrate is IBS-GZO/IBAD-MgO/RFsputter-LaMnO 3 /PLD-CeO 2 . The PLD-CeO 2 process is the rate limiting and cost dominant one in this architecture. It is proposed that the self-texturing CeO 2 layer thickness could be reduced by optimization of the MgO processing due to higher MgO texturing and/or effective growth of self-texturing CeO 2 . Influence of the IBAD beam conditions and deposition time has been studied to optimize the IBAD conditions. Optimized IBAD conditions were decided from the viewpoints of in-plane grain texturing and the stability to obtain high texturing on fabrication. The Δφ value of CeO 2 layer was improved from 4-5 o to 3-3.5 o by the optimization. This buffered substrate gave high and uniform I c values of 524-565 A/cm-width for 50 m long GdBCO (1.5 μm) tape, indicating uniform distribution of Δφ(CeO 2 ). This improvement of Δφ(CeO 2 ) enables to reduce the CeO 2 thickness down to 300 nm without making Δφ(CeO 2 ) > 5 o , which improves CeO 2 throughput from 10 m/h to 30 m/h. A 50 m long patch sample showed more uniform Δφ distribution around 4 o even by high speed of 30 m/h as CeO 2 through-put. Highly and uniformly textured CeO 2 buffered substrate was obtained in 100 m long cost-effectively by optimization of IBAD-MgO processing.

  1. Nanocrystalline ZnO film deposited by ultrasonic spray on textured silicon substrate as an anti-reflection coating layer

    International Nuclear Information System (INIS)

    Sali, S.; Boumaour, M.; Kechouane, M.; Kermadi, S.; Aitamar, F.

    2012-01-01

    A ZnO thin film was successfully synthesized on glass, flat surface and textured silicon substrates by chemical spray deposition. The textured silicon substrate was carried out using two solutions (NaOH/IPA and Na 2 CO 3 ). Textured with Na 2 CO 3 solution, the sample surface exhibits uniform pyramids with an average height of 5 μm. The properties and morphology of ZnO films were investigated. X-ray diffraction (XRD) spectra revealed a preferred orientation of the ZnO nanocrystalline film along the c-axis where the low value of the tensile strain 0.26% was obtained. SEM images show that all films display a granular, polycrystalline morphology. The morphology of the ZnO layers depends dramatically on the substrate used and follows the contours of the pyramids on the substrate surface. The average reflectance of the textured surface was found to be around 13% and it decreases dramatically to 2.57% after deposition of a ZnO antireflection coating. FT-IR peaks arising from the bonding between Zn-O are clearly represented using a silicon textured surface. A very intense photoluminescence (PL) emission peak is observed for ZnO/textured Si, revealing the good quality of the layer. The PL peak at 380.5 nm (UV emission) and the high-intensity PL peak at 427.5 nm are observed and a high luminescence occurs when using a textured Si substrate.

  2. Substrate texture affects female cricket walking response to male calling song

    Science.gov (United States)

    Sarmiento-Ponce, E. J.; Sutcliffe, M. P. F.; Hedwig, B.

    2018-03-01

    Field crickets are extensively used as a model organism to study female phonotactic walking behaviour, i.e. their attraction to the male calling song. Laboratory-based phonotaxis experiments generally rely on arena or trackball-based settings; however, no attention has been paid to the effect of substrate texture on the response. Here, we tested phonotaxis in female Gryllus bimaculatus, walking on trackballs machined from methyl-methacrylate foam with different cell sizes. Surface height variations of the trackballs, due to the cellular composition of the material, were measured with profilometry and characterized as smooth, medium or rough, with roughness amplitudes of 7.3, 16 and 180 µm. Female phonotaxis was best on a rough and medium trackball surface, a smooth surface resulted in a significant lower phonotactic response. Claws of the cricket foot were crucial for effective walking. Females insert their claws into the surface pores to allow mechanical interlocking with the substrate texture and a high degree of attachment, which cannot be established on smooth surfaces. These findings provide insight to the biomechanical basis of insect walking and may inform behavioural studies that the surface texture on which walking insects are tested is crucial for the resulting behavioural response.

  3. Uniform performance of continuously processed MOD-YBCO-coated conductors using a textured Ni-W substrate

    International Nuclear Information System (INIS)

    Verebelyi, D T; Schoop, U; Thieme, C; Li, X; Zhang, W; Kodenkandath, T; Malozemoff, A P; Nguyen, N; Siegal, E; Buczek, D; Lynch, J; Scudiere, J; Rupich, M; Goyal, A; Specht, E D; Martin, P; Paranthaman, M

    2003-01-01

    Second-generation coated conductor composite HTS wires have been fabricated using a continuous reel-to-reel process with deformation-textured Ni-W substrates and a metal-organic deposition process for YBa 2 Cu 3 O 7-x . Earlier results on 1 m long and 1 cm wide wires with 77 K critical current performance greater than 100 A cm -1 width have now been extended to 7.5 m in length and even higher performance, with one wire at 132 and another at 127 A cm -1 width. Performance as a function of wire length is remarkably uniform, with only 2-4% standard deviation when measured on a 50 cm length scale. The length-scale dependence of the deviation is compared with a statistical calculation. (rapid communication)

  4. Uniform performance of continuously processed MOD-YBCO-coated conductors using a textured Ni-W substrate

    Energy Technology Data Exchange (ETDEWEB)

    Verebelyi, D T [American Superconductor Corporation, Westborough, MA 01581 (United States); Schoop, U [American Superconductor Corporation, Westborough, MA 01581 (United States); Thieme, C [American Superconductor Corporation, Westborough, MA 01581 (United States); Li, X [American Superconductor Corporation, Westborough, MA 01581 (United States); Zhang, W [American Superconductor Corporation, Westborough, MA 01581 (United States); Kodenkandath, T [American Superconductor Corporation, Westborough, MA 01581 (United States); Malozemoff, A P [American Superconductor Corporation, Westborough, MA 01581 (United States); Nguyen, N [American Superconductor Corporation, Westborough, MA 01581 (United States); Siegal, E [American Superconductor Corporation, Westborough, MA 01581 (United States); Buczek, D [American Superconductor Corporation, Westborough, MA 01581 (United States); Lynch, J [American Superconductor Corporation, Westborough, MA 01581 (United States); Scudiere, J [American Superconductor Corporation, Westborough, MA 01581 (United States); Rupich, M [American Superconductor Corporation, Westborough, MA 01581 (United States); Goyal, A [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Specht, E D [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Martin, P [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Paranthaman, M [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States)

    2003-05-01

    Second-generation coated conductor composite HTS wires have been fabricated using a continuous reel-to-reel process with deformation-textured Ni-W substrates and a metal-organic deposition process for YBa{sub 2}Cu{sub 3}O{sub 7-x}. Earlier results on 1 m long and 1 cm wide wires with 77 K critical current performance greater than 100 A cm{sup -1} width have now been extended to 7.5 m in length and even higher performance, with one wire at 132 and another at 127 A cm{sup -1} width. Performance as a function of wire length is remarkably uniform, with only 2-4% standard deviation when measured on a 50 cm length scale. The length-scale dependence of the deviation is compared with a statistical calculation. (rapid communication)

  5. Metal plating removal from insulator substrate using pulsed arc discharge

    Science.gov (United States)

    Imasaka, K.; Gnapowski, S.; Akiyama, H.

    2014-06-01

    Removal technique of metal materials from a metal plating insulator substrate using a pulsed arc discharge was proposed and its fundamental characteristics were investigated. The metal plating substrate with three metal-layers structure (cupper, nickel and gold layers) is used as the sample substrate. Repetitive pulsed arc discharge plasma is generated using three types of electrode systems. Effects of the electrode systems on the metal plating removal from the insulator substrate were investigated. The metal plating was removed by the pulsed arc discharge between the electrode and substrate surface. A part of the gold layer, which is the topmost metal layer on the insulator substrate is vaporized and removed by the repetitive pulsed arc discharges.

  6. Texture evolution and mechanical behaviour of irradiated face-centred cubic metals.

    Science.gov (United States)

    Chen, L R; Xiao, X Z; Yu, L; Chu, H J; Duan, H L

    2018-02-01

    A physically based theoretical model is proposed to investigate the mechanical behaviour and crystallographic texture evolution of irradiated face-centred cubic metals. This model is capable of capturing the main features of irradiated polycrystalline materials including irradiation hardening, post-yield softening and plasticity localization. Numerical results show a good agreement with experimental data for both unirradiated and irradiated stress-strain relationships. The study of crystallographic texture reveals that the initial randomly distributed texture of unirradiated metals under tensile loading can evolve into a mixture of [111] and [100] textures. Regarding the irradiated case, crystallographic texture develops in a different way, and an extra part of [110] texture evolves into [100] and [111] textures. Thus, [100] and [111] textures become dominant more quickly compared with those of the unirradiated case for the reason that [100] and [111]-oriented crystals have higher strength, and their plastic deformation behaviours are more active than other oriented crystals. It can be concluded that irradiation-induced defects can affect both the mechanical behaviour and texture evolution of metals, both of which are closely related to irradiation hardening.

  7. The quantitative representation of fiber-and sheet-texture in metals of cubic system

    International Nuclear Information System (INIS)

    Kim, H.J.; Kim, S.C.; Chun, B.C.; Lee, C.Y.

    1983-01-01

    This is the first article of a series dealing with studies on the quantitative representation of fiber-and sheet-type textures in metals of cubic crystal system. Texture measurements by neutron diffraction method are analyzed using Bunge's series expansion method and the effect of series truncation is studied for samples of various texture sharpness. The present article describes two computer programs, TXFIB and TXSHT, develped for the analysis of the respective fiber-and sheet-type texture. Using these computer programs, the orientation distribution function can be expanded in the series of generalized spherical harmonics up to 58th term from 6 experimental pole figures as input. Estimations of various errors involved in the texture analysis and texture sharpness index are also included in the programs. (Author)

  8. Texture formation in metals with bcc lattice during drawing in dead rollers

    International Nuclear Information System (INIS)

    Gubchevskij, V.P.; Zemlyanskov, V.A.; Zlatoustovskij, D.M.; Nemkina, Eh.D.

    1976-01-01

    The texture of low-carbon steel, molybdenum and tungsten wires subjected to intermediate and finish drawing were studied to find whether it is common to metals with a body-centered lattice. Experimental data tend to indicate that both the intermediate drawing and the finish drawing give rise to two axial textures, or (110) and (114), parallel to the axis of drawing. It was inferred that the mechanism of the formation of texture in drawing is common to all the metals of a VCC lattice

  9. High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Dutta, P.; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V.; Zheng, N.; Ahrenkiel, P.; Martinez, J.

    2014-01-01

    We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ∼10 7  cm −2 . Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300 cm 2 /V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

  10. Enhancement of c-axis texture of AlN films by substrate implantation

    International Nuclear Information System (INIS)

    Chen, C.H.; Yeh, J.M.; Hwang, J.

    2005-01-01

    Highly oriented AlN films are successfully deposited on B + implanted Si(1 1 1) substrates in a radio frequency inductively coupled plasma (RF/ICP) system. The implanted energy and dose used for the B + implanted Si(1 1 1) substrates are 200 keV and 10 15 cm -2 , respectively. The c-axis texture of AlN films can be affected by RF gun power and ion implantation. Experimental results show that the full width at half-maximum (FWHM) of AlN(0 0 2) in the X-ray rocking curve measurements decreases with increasing RF gun power. The optimum condition is at 500 W, where the FWHM of the AlN films deposited on Si(1 1 1) with and without B + implantation are 2.77 and 3.17, respectively. In average, the FWHM of the AlN films on B + implanted Si(1 1 1) are less than those on Si(1 1 1) by a factor of ∼10%. The enhancement of c-axis of AlN films due to B + implantation is attributed to the reduction of AlN grains. Raman spectra also suggest that ion implantation plays a role in reducing the tensile stress in AlN films deposited on B + implanted Si(1 1 1)

  11. System and process for aluminization of metal-containing substrates

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.

    2017-12-12

    A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices that can degrade performance during operation at high temperature.

  12. Cube Texture Formation of Cu-33at.%Ni Alloy Substrates and CeO2 Buffer Layer for YBCO Coated Conductors

    DEFF Research Database (Denmark)

    Tian, Hui; Li, Suo Hong; Ru, Liang Ya

    2014-01-01

    .%Ni alloy substrate with the cube texture fraction of 99.8 % (omega-scan in this substrate were 7.31° and 5.51°, respectively. Furthermore, the cube texture fraction...... of epitaxially grown CeO2 buffer layer was 95 % (omega-scan being 6.98° and 5.92°, respectively....

  13. Application of a mixed metal oxide catalyst to a metallic substrate

    Science.gov (United States)

    Sevener, Kathleen M. (Inventor); Lohner, Kevin A. (Inventor); Mays, Jeffrey A. (Inventor); Wisner, Daniel L. (Inventor)

    2009-01-01

    A method for applying a mixed metal oxide catalyst to a metallic substrate for the creation of a robust, high temperature catalyst system for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in propulsion systems. The method begins by forming a prepared substrate material consisting of a metallic inner substrate and a bound layer of a noble metal intermediate. Alternatively, a bound ceramic coating, or frit, may be introduced between the metallic inner substrate and noble metal intermediate when the metallic substrate is oxidation resistant. A high-activity catalyst slurry is applied to the surface of the prepared substrate and dried to remove the organic solvent. The catalyst layer is then heat treated to bind the catalyst layer to the surface. The bound catalyst layer is then activated using an activation treatment and calcinations to form the high-activity catalyst system.

  14. Quantitative texture analysis of metal sheets and polymer foils by neutron diffraction

    Science.gov (United States)

    Vratislav, Stanislav; Dlouhá, Maja; Kalvoda, Ladislav; Grishin, Alexander

    2006-11-01

    Experimental and calculation techniques for quantitative texture analysis based on the ODF combined with the diffraction of thermal neutrons were developed and tested. In our work the texture of the oriented steel sheets was investigated after different stages of their processing. The texture experiments were carried out on the KSN-2 diffractometer (installed by the LVR-15 reactor in Rez near Prague) which is equipped with the TG-1 texture goniometer-supplied automatic data collection for transmission and reflection geometry. The TODF-N package was used and the ODF values were obtained together with all texture characteristics. Although most of our texture studies performed until recently concentrated on metallic materials, now we have extended research field to texture investigation of semi-crystalline polymer materials (rigid PVC foils) finding an extensive industrial application. Results achieved in our study confirm that the quantitative texture analysis in connection with neutron diffraction can help to improve the technology of the preparation of oriented magnetic steel sheets and to determine the final functional properties of polymer foils.

  15. Metal substrates with nanometer scale surface roughness for flexible electronics

    Science.gov (United States)

    Lee, Jong-Lam; Kim, Kisoo

    2012-09-01

    In this work, we present a novel way in fabricating a metal substrate with nanometer scale in surface roughness (Ra INVAR (Invariable alloy) one (20 cm × 20 cm, Ra = 1.40 nm) were demonstrated. The INVAR film was used as a substrate for fabricating organic light emitting diodes (OLED) and organic photovoltaic (OPV). The optical and electrical characteristics of OLEDs and OPVs using the INVAR were comparable to those using a conventional ITO glass substrate.

  16. Microstructure, Texture, and Mechanical Property Analysis of Gas Metal Arc Welded AISI 304 Austenitic Stainless Steel

    Science.gov (United States)

    Saha, Saptarshi; Mukherjee, Manidipto; Pal, Tapan Kumar

    2015-03-01

    The present study elaborately explains the effect of welding parameters on the microstructure, texture, and mechanical properties of gas metal arc welded AISI 304 austenitic stainless steel sheet (as received) of 4 mm thickness. The welded joints were prepared by varying welding speed (WS) and current simultaneously at a fixed heat input level using a 1.2-mm-diameter austenitic filler metal (AISI 316L). The overall purpose of this study is to investigate the effect of the variation of welding conditions on: (i) Microstructural constituents using optical microscope and transmission electron microscope; (ii) Micro-texture evolution, misorientation distributions, and grain boundaries at welded regions by measuring the orientation data from electron back scattered diffraction; and (iii) Mechanical properties such as hardness and tensile strength, and their correlation with the microstructure and texture. It has been observed that the higher WS along with the higher welding current (weld metal W1) can enhance weld metal mechanical properties through alternation in microstructure and texture of the weld metal. Higher δ-ferrite formation and high-angle boundaries along with the + grain growth direction of the weld metal W1 were responsible for dislocation pile-ups, SFs, deformation twinning, and the induced martensite with consequent strain hardening during tensile deformation. Also, fusion boundary being the weakest link in the welded structure, failure took place mainly at this region.

  17. Influence of deposition conditions and substrate morphology on the electrical properties of sputtered ZnO:Al grown on texture-etched glass

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Nicolas, E-mail: n.sommer@fz-juelich.de [IEK5 — Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Götzendörfer, Stefan [Berliner Glas Surface Technology, 89428 Syrgenstein (Germany); Köhler, Florian [IEK5 — Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Ziegner, Mirko [IEK2 — Werkstoffstruktur und -eigenschaften, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Hüpkes, Jürgen [IEK5 — Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany)

    2014-10-01

    The focus of this work is the growth of aluminum-doped zinc oxide (ZnO:Al) on texture-etched glass substrates. We investigated the influence of sputter parameters, pressure and temperature on the charge carrier mobility of ZnO:Al films grown on different substrate textures. An optimized sputtering process was developed which led to charge carrier mobilities on textured substrates that are close to those on flat substrates. Based on X-ray diffraction measurements, we qualitatively explain the effect of different sputtering conditions. Furthermore, the ZnO:Al charge carrier mobility was related to the substrate morphology. ZnO:Al films on U-shaped surface morphologies showed significantly higher charge carrier mobilities than those on V-shaped structures. ZnO:Al damp heat stability and etching behavior provided evidence that the number of ZnO:Al growth disturbances on textured substrates can be reduced by adequate substrate morphology and sputtering conditions. - Highlights: • Growth of ZnO:Al on various texture-etched glass substrates • Reduced influence of growth disturbances using optimized sputtering conditions • Higher ZnO:Al charge carrier mobility on U-shaped than on V-shaped textures.

  18. Textured surface boron-doped ZnO transparent conductive oxides on polyethylene terephthalate substrates for Si-based thin film solar cells

    International Nuclear Information System (INIS)

    Chen Xinliang; Lin Quan; Ni Jian; Zhang Dekun; Sun Jian; Zhao Ying; Geng Xinhua

    2011-01-01

    Textured surface boron-doped zinc oxide (ZnO:B) thin films were directly grown via low pressure metal organic chemical vapor deposition (LP-MOCVD) on polyethylene terephthalate (PET) flexible substrates at low temperatures and high-efficiency flexible polymer silicon (Si) based thin film solar cells were obtained. High purity diethylzinc and water vapors were used as source materials, and diborane was used as an n-type dopant gas. P-i-n silicon layers were fabricated at ∼ 398 K by plasma enhanced chemical vapor deposition. These textured surface ZnO:B thin films on PET substrates (PET/ZnO:B) exhibit rough pyramid-like morphology with high transparencies (T ∼ 80%) and excellent electrical properties (Rs ∼ 10 Ω at d ∼ 1500 nm). Finally, the PET/ZnO:B thin films were applied in flexible p-i-n type silicon thin film solar cells (device structure: PET/ZnO:B/p-i-n a-Si:H/Al) with a high conversion efficiency of 6.32% (short-circuit current density J SC = 10.62 mA/cm 2 , open-circuit voltage V OC = 0.93 V and fill factor = 64%).

  19. Texture characterisation of hexagonal metals: Magnesium AZ91 alloy, welded by laser processing

    International Nuclear Information System (INIS)

    Kouadri, A.; Barrallier, L.

    2006-01-01

    Cooled and cast magnesium AZ91 alloy was welded using a CO 2 laser. The changes in the microstructure were analysed by optical and scanning electron microscopy and X-ray diffraction. Modification of the anisotropic properties was evaluated by the characterization of the texture in the base metal, in the core of the welded zone and in the welded zone close to the surface. In the two former zones, we have not observed a texture. Laser welding only leads to a change of the grain size and a disappearance of the eutectic phase. By contrast, in the welded zone close to the surface, the laser process leads both to a finer microstructure, to a loss of the Al-content and to the presence of several texture components. In this zone, our results showed that these textures are on pyramidal {101-bar 1} and prismatic {101-bar 0} planes. Much of the explanation for such texture rests with the fact that during the laser welding, material solidifies in strong non-equilibrium conditions. The kinetics of the nucleation and the growth are partly controlled by the high-rise and high fall of the temperature and the power produced by the laser process. The nature of the texture has been explained by the presence of a columnar to equiaxed transition in the welded zone

  20. Growth and BZO-doping of the nanostructured YBCO thin films on buffered metal substrates

    DEFF Research Database (Denmark)

    Huhtinen, H.; Irjala, M.; Paturi, P.

    2010-01-01

    The growth of the nanostructured YBa2Cu3O6+x (YBCO) films is investigated for the first time on biaxially textured NiW substrates used in coated conductor technology. The optimization process of superconducting layers is made in wide magnetic field and temperature range in order to understand...... the vortex pinning structure and mechanism in our films prepared from nanostructured material. Structural analysis shows that growth mechanism in YBCO films grown on NiW is completely different when compared to YBCO on STO. Films on NiW are much rougher, there is huge in-plane variation of YBCO crystals...... and moreover out-of-plane long range lattice ordering is greatly reduced. Magnetic measurements demonstrate that jc in films grown on NiW is higher in high magnetic fields and low temperatures. This effect is connected to the amount of pinning centres observed in films on metal substrates which are effective...

  1. White Top-Emitting OLEDs on Metal Substrates

    OpenAIRE

    Freitag, Patricia

    2011-01-01

    This work focusses on the development of top-emitting white organic light-emitting diodes (OLEDs), which can be fabricated on metal substrates. Bottom-emitting OLEDs have been studied intensively over the years and show promising perspectives for future commercial applications in general lighting. The development of top-emitting devices has fallen behind despite the opportunities to produce these devices also on low-cost opaque substrates. This is due to the challenges of top-light-emission c...

  2. Stress in and texture of PVD deposited metal nitride films

    NARCIS (Netherlands)

    Machunze, R.

    2010-01-01

    Thin metal nitride films deposited by Physical Vapor Deposition (PVD) are used amongst many other applications as wear protective coatings in tool industry or as diffusion barriers in integrated circuit technology. Typically these films exhibit a residual in-plane stress when deposited onto rigid

  3. Catalytic Metallodrugs: Substrate-Selective Metal Catalysts as Therapeutics.

    Science.gov (United States)

    Yu, Zhen; Cowan, James A

    2017-10-12

    Metal complexes that catalyze inactivation and degradation of biomolecular targets can be developed into novel therapeutics (catalytic metallodrugs) against a variety of diseases. Despite recent advances in the field, a lack of substrate selectivity is a major hindrance to the development of catalytic metallodrugs for application in clinical practice. Improved targeting can minimize nonselective activity and the potential for side effects. Herein, we focus on recent developments toward novel metal catalysts that exhibit substrate selectivity against a variety of therapeutically relevant biomolecules. Design strategies for developing selective catalytic metallodrugs are also highlighted. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Textured Sb2Te3 films and GeTe/Sb2Te3 superlattices grown on amorphous substrates by molecular beam epitaxy

    NARCIS (Netherlands)

    Boschker, Jos E.; Tisbi, E.; Placidi, E.; Momand, Jamo; Redaelli, Andrea; Kooi, Bart J.; Arciprete, Fabrizio; Calarco, Raffaella

    The realization of textured films of 2-dimensionally (2D) bonded materials on amorphous substrates is important for the integration of this material class with silicon based technology. Here, we demonstrate the successful growth by molecular beam epitaxy of textured Sb2Te3 films and GeTe/Sb2Te3

  5. Rational growth of semi-polar ZnO texture on a glass substrate for optoelectronic applications

    Science.gov (United States)

    Lu, B.; Ma, M. J.; Ye, Y. H.; Lu, J. G.; He, H. P.; Ye, Z. Z.

    2013-02-01

    Semi-polar ZnO films with surface texture were grown on glass substrates via pulsed-laser deposition (PLD) through Co-Ga co-doping. Oxygen pressure (PO2) was found to have significant effects on the structural and optical properties of the Zn(Co, Ga)O (ZCGO) films. A self-textured film with (1\\,0\\,\\bar {1}\\,1) preferred orientation (PO) was achieved by varying the growth conditions including a crucial narrow PO2 window and growth time. A possible mechanism underlying the PO evolution and the final texture of the films was proposed, which can be attributed to the collaboration of the doping effect and the PO2-dependent evolutionary selection process, in which certain grains can have increased vertical growth rate with respect to the substrate surface through interplane diffusion. Moreover, the growth of undoped pure ZnO films proceeded by using the (1\\,0\\,\\bar {1}\\,1) ZCGO film as a buffer layer. The ZnO layers retained a semi-polar characteristic with improved crystallinity and better optical quality. The epitaxy-like orientation of ZnO layers grown on (1\\,0\\,\\bar {1}\\,1) ZCGO films has applications in the development of semi-polar ZnO-based light-emitting diodes.

  6. Itqiy: A metal-rich enstatite meteorite with achondritic texture

    Science.gov (United States)

    Patzer, Andrea; Hill, Dolores H.; Boynton, William V.

    2001-11-01

    Itqiy is a unique coarse-grained, metal-rich enstatite meteorite that was found in the Western Sahara and consists of two rocks together weighing 4.72 kg, which are both completely coated with fusion crust. We report results from our electron microprobe and INAA techniques. Itqiy consists of subhedral, equigranular, millimeter-sized enstatite, ~ 25 vol% of mm-sized kamacite and a few tiny intergrowths of sulfides and kamacite. Relic chondrules are absent. Pyroxene (Fs 0.2) is chemically similar to enstatite in EL chondrites, but the metal is closer in composition to that in EH chondrites. Sulfides resemble those in E chondrites but their compositions are distinct from those in both EL and EH chondrites. Itqiy clearly formed under very reducing conditions, but it does not appear to have formed from EH or EL chondrites. Two thermal events can be distinguished. Silicate compositions including REE abundances indicate loss of partial melt and slow cooling. Heterogeneous sulfides indicate a subsequent reheating and quenching event, which may have been due to shock as many enstatite grains show shock stage S3 features.

  7. Development of textured ZnO-coated low-cost glass substrate with very high haze ratio for silicon-based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hongsingthong, Aswin, E-mail: aswin.hongsingthong@nectec.or.th [Solar Energy Technology Laboratory, National Electronics and Computer Technology Center, 112 Thailand Science Park, Phahonyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120 (Thailand); Krajangsang, Taweewat; Limmanee, Amornrat; Sriprapha, Kobsak; Sritharathikhun, Jaran [Solar Energy Technology Laboratory, National Electronics and Computer Technology Center, 112 Thailand Science Park, Phahonyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120 (Thailand); Konagai, Makoto [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, NE-15, O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2013-06-30

    Zinc oxide (ZnO) films with a very high haze ratio and low resistivity were developed on soda–lime glass substrate by using reactive ion etching (RIE) treatment with carbon tetrafluoride (CF{sub 4}) to modify the substrate surface morphology before the deposition of ZnO films. We found that the surface morphology of the ZnO films deposited by metal organic chemical vapor deposition (MOCVD) technique could be modified by varying the glass treatment conditions and the gas pressure was a key parameter. With increasing glass-etching pressure, the surface morphology of the ZnO films changed from conventional pyramid-like single texture to greater cauliflower-like double texture, leading to significant increases in root mean square roughness and haze ratio of the films. By employing the developed high-haze ZnO films as a front transparent conductive oxide (TCO) layer in microcrystalline silicon solar cells, an enhancement in the quantum efficiency in the long-wavelength region has been achieved. Experimental results have verified that our unique and original glass etching treatment is a simple and effective technique to improve the light-scattering properties of the ZnO films while preserving their good transparency and electrical properties. Thus, the ZnO films deposited on etched soda–lime glass have a high potential for the use as a front TCO layer in thin-film Si solar cells. - Highlights: • High-haze zinc oxide (ZnO) grown on low cost soda–lime glass has been developed. • Surface of the ZnO can be modified by varying glass-substrate etching conditions. • Glass-etching pressure is a key to increase haze ratio of the ZnO films. • Higher cell efficiency has been achieved from cell using etched glass. • High-haze ZnO coated glass is a promising transparent conductive oxide coated glass.

  8. High haze textured surface B-doped ZnO-TCO films on wet-chemically etched glass substrates for thin film solar cells

    Science.gov (United States)

    Xinliang, Chen; Jieming, Liu; Jia, Fang; Ze, Chen; Ying, Zhao; Xiaodan, Zhang

    2016-08-01

    Textured glass substrates with crater-like feature sizes of ˜5-30 μm were obtained using the chemical etching method through adjusting the treatment round (R). Pyramid-like boron-doped zinc oxide (ZnO:B) films with feature sizes of ˜300-800 nm were deposited on the etched glass substrates by the metal organic chemical deposition (MOCVD) technique using water, diethylzinc and 1%-hydrogen-diluted diborane. The ZnO:B films on the etched glass with micro/nano double textures presented a much stronger light-scattering capability than the conventional ZnO:B on the flat glass and their electrical properties changed little. Typical etched glass-3R/ZnO:B exhibited a high root mean square (RMS) roughness of ˜160 nm. The haze values at the wavelengths of 550 nm and 850 nm for etched glass-3R/ZnO:B sample were 61% and 42%, respectively. Finally, the optimized etched glass/ZnO:B was applied in the silicon (Si) based thin film solar cells. The high haze etched glass/ZnO:B substrates have potential merits for thin film solar cells. Project supported by the State Key Development Program for Basic Research of China (Nos. 2011CBA00706, 2011CBA00707), the Tianjin Applied Basic Research Project and Cutting-Edge Technology Research Plan (No. 13JCZDJC26900), the Tianjin Major Science and Technology Support Project (No. 11TXSYGX22100), the National High Technology Research and Development Program of China (No. 2013AA050302), and the Fundamental Research Funds for the Central Universities (No. 65010341).

  9. Microstructured silicone substrate for printable and stretchable metallic films.

    Science.gov (United States)

    Robinson, Adam P; Minev, Ivan; Graz, Ingrid M; Lacour, Stéphanie P

    2011-04-19

    Stretchable electronics (i.e., hybrid inorganic or organic circuits integrated on elastomeric substrates) rely on elastic wiring. We present a technique for fabricating reversibly stretchable metallic films by printing silver-based ink onto microstructured silicone substrates. The wetting and pinning of the ink on the elastomer surface is adjusted and optimized by varying the geometry of micropillar arrays patterned on the silicone substrate. The resulting films exhibit high electrical conductivity (∼11 000 S/cm) and can stretch reversibly to 20% strain over 1000 times without failing electrically. The stretchability of the ≥200 nm thick metallic film relies on engineered strain relief in the printed film on patterned PDMS. © 2011 American Chemical Society

  10. Superior light metals by texture engineering: Optimized aluminum and magnesium alloys for automotive applications

    International Nuclear Information System (INIS)

    Hirsch, J.; Al-Samman, T.

    2013-01-01

    Aluminum and magnesium are two highly important lightweight metals used in automotive applications to reduce vehicle weight. Crystallographic texture engineering through a combination of intelligent processing and alloying is a powerful and effective tool to obtain superior aluminum and magnesium alloys with optimized strength and ductility for automotive applications. In the present article the basic mechanisms of texture formation of aluminum and magnesium alloys during wrought processing are described and the major aspects and differences in deformation and recrystallization mechanisms are discussed. In addition to the crystal structure, the resulting properties can vary significantly, depending on the alloy composition and processing conditions, which can cause drastic texture and microstructure changes. The elementary mechanisms of plastic deformation and recrystallization comprising nucleation and growth and their orientation dependence, either within the homogeneously formed microstructure or due to inhomogeneous deformation, are described along with their impact on texture formation, and the resulting forming behavior. The typical face-centered cubic and hexagonal close-packed rolling and recrystallization textures, and related mechanical anisotropy and forming conditions are analyzed and compared for standard aluminum and magnesium alloys. New aspects for their modification and advanced strategies of alloy design and microstructure to improve material properties are derived

  11. Femtosecond laser texturing of glass substrates for improved light in-coupling in thin-film photovoltaics

    Science.gov (United States)

    Imgrunt, J.; Chakanga, K.; von Maydell, K.; Teubner, U.

    2017-12-01

    Due to their low thickness, thin-film solar cells usually suffer from poor light absorption. To improve this situation, light-management is necessary. Within the present work, in order to enhance light coupling, an ultra-short-pulse laser is used for texturing substrates. Here commercially available multi component soda lime glass substrates are patterned with a dot grid at ambient air pressure with 150 fs pulses, centered at a wavelength of 775 nm. The structures consist of small depressions with approximately 3 μ m diameter. Varying depths of around 300 nm could be well reproduced. Reducing the pitch (distance between structure-to-structure centers), from ten to approximately one times the crater diameter, influences the structure quality and increases the deformation of the surface in the vicinity of the depressions. Consequently, the diffuse light scattering is improved from 0 to 30% haze. Overall, the presented approach is quite simple. This single-step texturing technique which can be easily used on different substrates is applicable in a wide range of thin-film solar cells. It has the advantage that ultra-thin electrodes can be used as the front contact as well as the potential to be integrated into a PV production line. Thus, complicated layer stacks for absorption enhancement can be avoided.

  12. Single-crystal metal growth on amorphous insulating substrates.

    Science.gov (United States)

    Zhang, Kai; Pitner, Xue Bai; Yang, Rui; Nix, William D; Plummer, James D; Fan, Jonathan A

    2018-01-23

    Metal structures on insulators are essential components in advanced electronic and nanooptical systems. Their electronic and optical properties are closely tied to their crystal quality, due to the strong dependence of carrier transport and band structure on defects and grain boundaries. Here we report a method for creating patterned single-crystal metal microstructures on amorphous insulating substrates, using liquid phase epitaxy. In this process, the patterned metal microstructures are encapsulated in an insulating crucible, together with a small seed of a differing material. The system is heated to temperatures above the metal melting point, followed by cooling and metal crystallization. During the heating process, the metal and seed form a high-melting-point solid solution, which directs liquid epitaxial metal growth. High yield of single-crystal metal with different sizes is confirmed with electron backscatter diffraction images, after removing the insulating crucible. Unexpectedly, the metal microstructures crystallize with the [Formula: see text] direction normal to the plane of the film. This platform technology will enable the large-scale integration of high-performance plasmonic and electronic nanosystems.

  13. Enhanced quantum efficiency of photoelectron emission, through surface textured metal electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, Anna; Bandaru, Prabhakar R., E-mail: pbandaru@ucsd.edu [Program in Materials Science, Department of Mechanical Engineering, University of California, San Diego, La Jolla, California, 92130 (United States); Moody, Nathan A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-03-15

    It is predicted that the quantum efficiency (QE) of photoelectron emission from metals may be enhanced, possibly by an order of magnitude, through optimized surface texture. Through extensive computational simulations, it is shown that the absorption enhancement in select surface groove geometries may be a dominant contributor to enhanced QE and corresponds to localized Fabry–Perot resonances. The inadequacy of extant analytical models in predicting the QE increase, and suggestions for further improvement, are discussed.

  14. Texture-geometric deformational effects in some metal-hydrogen systems

    International Nuclear Information System (INIS)

    Spivak, L.V.; Kats, M.Ya.

    1992-01-01

    Possible deformation effects were studied in vanadium, tantalum, niobium, palladium and iron which occurred during electrolytic hydrogenation of specimens preliminarily deformed by torsion and then annealed. Noticeable texture-geometric effects were observed and related to the system tendency to enhance the degree of specimen form symmetry during hydrogenation. The latter was an off-beat realization of Le-Chatelier principle. It was assumed that the nature of deformation effects was connected with one of minimization channels for overall elastic stress fields in metals being hydrogenated. Some distinction was revealed in behaviour of 5a group metal, palladium and iron

  15. Structural coloration of metallic surfaces with micro/nano-structures induced by elliptical vibration texturing

    Science.gov (United States)

    Yang, Yang; Pan, Yayue; Guo, Ping

    2017-04-01

    Creating orderly periodic micro/nano-structures on metallic surfaces, or structural coloration, for control of surface apparent color and optical reflectivity has been an exciting research topic over the years. The direct applications of structural coloration include color marking, display devices, and invisibility cloak. This paper presents an efficient method to colorize metallic surfaces with periodic micro/nano-gratings using elliptical vibration texturing. When the tool vibration is coupled with a constant cutting velocity, controlled periodic ripples can be generated due to the overlapping tool trajectory. These periodic ripples with a wavelength near visible spectrum can act as micro-gratings to introduce iridescent colors. The proposed technique also provides a flexible method for color marking of metallic surfaces with arbitrary patterns and images by precise control of the spacing distance and orientation of induced micro/nano-ripples. Theoretical analysis and experimental results are given to demonstrate structural coloration of metals by a direct mechanical machining technique.

  16. Assessment of Automotive Coatings Used on Different Metallic Substrates

    OpenAIRE

    Bensalah, W.; Loukil, N.; Wery, M. De-Petris; Ayedi, H. F.

    2014-01-01

    Four epoxy primers commonly used in the automotive industry were applied by gravity pneumatic spray gun over metallic substrates, specifically, steel, electrogalvanized steel, hot-dip galvanized steel, and aluminum. A two-component polyurethane resin was used as topcoat. To evaluate the performance of the different coating systems, the treated panels were submitted to mechanical testing using Persoz hardness, impact resistance, cupping, lattice method, and bending. Tribological properties of ...

  17. High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, P., E-mail: pdutta2@central.uh.edu; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V. [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); Zheng, N.; Ahrenkiel, P. [Department of Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701 (United States); Martinez, J. [Materials Evaluation Laboratory, NASA Johnson Space Center, Houston, Texas 77085 (United States)

    2014-09-01

    We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ∼10{sup 7 }cm{sup −2}. Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300 cm{sup 2}/V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

  18. Epitaxial growth of nobel metals on alumina substrates

    International Nuclear Information System (INIS)

    Al-Mohammad, A.

    2007-06-01

    The influence of the reconstructed (0001) α-Al 2 O 3 surface on the heteroepitaxial growth and adhesion properties of small metal particles (gold, silver and copper) of noncontinuous thin films has been investigated. The crystallographic structure and morphology of substrate surfaces were examined by Reflection High Energy Electron Diffraction and Atomic Force Microscopy techniques. The reconstructed surfaces are terminated by one or more Aluminum atomic layers. By means of the Transmission Electronic Microscopy, the various granulometric and lattice parameters variations are investigated during different stages of the heteroepitaxial growth of metallic thin films. We estimated the adhesion energy values for each case of metal//(0001)α-Al 2 O 3 interfaces by two methods: the maximum cluster density and the Lifshits theory of Van der Waals energy of interfaces. The results of both methods are in good agreement. Using these methods, we found interfaces Hamaker's constants values and we investigated all the heteroepitaxial growth steps.(author)

  19. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by super duplex filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9 (Canada)

    2015-08-15

    In the present paper, microstructural changes across an as-welded dissimilar austenitic/duplex stainless steel couple welded by a super duplex stainless steel filler metal using gas tungsten arc welding process is characterized with optical microscopy and electron back-scattered diffraction techniques. Accordingly, variations of microstructure, texture, and grain boundary character distribution of base metals, heat affected zones, and weld metal were investigated. The results showed that the weld metal, which was composed of Widmanstätten austenite side-plates and allotriomorphic grain boundary austenite morphologies, had the weakest texture and was dominated by low angle boundaries. The welding process increased the ferrite content but decreased the texture intensity at the heat affected zone of the super duplex stainless steel base metal. In addition, through partial ferritization, it changed the morphology of elongated grains of the rolled microstructure to twinned partially transformed austenite plateaus scattered between ferrite textured colonies. However, the texture of the austenitic stainless steel heat affected zone was strengthened via encouraging recrystallization and formation of annealing twins. At both interfaces, an increase in the special character coincident site lattice boundaries of the primary phase as well as a strong texture with <100> orientation, mainly of Goss component, was observed. - Graphical abstract: Display Omitted - Highlights: • Weld metal showed local orientation at microscale but random texture at macroscale. • Intensification of <100> orientated grains was observed adjacent to the fusion lines. • The austenite texture was weaker than that of the ferrite in all duplex regions. • Welding caused twinned partially transformed austenites to form at SDSS HAZ. • At both interfaces, the ratio of special CSL boundaries of the primary phase increased.

  20. The Effects of Texture on the Resistivity of Thin Metallic Face-Centered Cubic Films

    Science.gov (United States)

    Soss, Steven Robert

    This thesis is concerned with the identification of the role of texture to the resistivity in thin silver, copper, and aluminum films. The results of this work can, in principle, be applied to any cubic structure, electronic conduction metal film with suitable changes to the calculations. We utilize the theory of Mayadas and Shatzke, and extended by Tellier, et. al., for electron transport properties at the grain boundaries. In particular, the theory is used to determine the probability of specular transmittance of an electron through the grain boundary. In addition, a Monte-Carlo simulation was developed which, given the measured texture distribution in the film, can determine the effective dislocation density at the grain boundary. It is found that the density of dislocations at the grain boundary can be identified as the underlying cause for the resistivity changes with texture. The films are deposited using the partially ionized beam (PIB) deposition system. The PIB technique utilizes a small percentage of ions derived from the evaporant flux to bombard the growth front during deposition. This deposition technique is unique in the fact that the texture distribution in the film can be dramatically changed while keeping the grain size relatively constant and while avoiding the incorporation of foreign species as impurities in the film. The films were deposited on glass microslides. Resistivity was measured using a standard four-point probe technique, grain size measurements were performed using X-ray and atomic force microscopy, and the film thickness was determined using a Tencor Alpha Step profilometer. The texture distribution in the film was measured by the X-ray Pole Figure technique, which found all the films to possess a fiber texture. Using the dislocation core model, an expression for the potential seen by an electron at the boundary can be written. The solution to the wave equation gives rise to a probability for the electron to be specularly

  1. Single crystalline metal films as substrates for graphene growth

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, Patrick; Henss, Ann-Kathrin; Wintterlin, Joost [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen (Germany); Weinl, Michael; Schreck, Matthias [Institut fuer Physik, Universitaet Augsburg (Germany); Speck, Florian; Ostler, Markus [Lehrstuhl fuer Technische Physik, Universitaet Erlangen-Nuernberg, Erlangen (Germany); Institut fuer Physik, Technische Universitaet Chemnitz (Germany); Seyller, Thomas [Institut fuer Physik, Technische Universitaet Chemnitz (Germany)

    2017-11-15

    Single crystalline metal films deposited on YSZ-buffered Si(111) wafers were investigated with respect to their suitability as substrates for epitaxial graphene. Graphene was grown by CVD of ethylene on Ru(0001), Ir(111), and Ni(111) films in UHV. For analysis a variety of surface science methods were used. By an initial annealing step the surface quality of the films was strongly improved. The temperature treatments of the metal films caused a pattern of slip lines, formed by thermal stress in the films, which, however, did not affect the graphene quality and even prevented wrinkle formation. Graphene was successfully grown on all three types of metal films in a quality comparable to graphene grown on bulk single crystals of the same metals. In the case of the Ni(111) films the originally obtained domain structure of rotational graphene phases could be transformed into a single domain by annealing. This healing process is based on the control of the equilibrium between graphene and dissolved carbon in the film. For the system graphene/Ni(111) the metal, after graphene growth, could be removed from underneath the epitaxial graphene layer by a pure gas phase reaction, using the reaction of CO with Ni to give gaseous Ni(CO){sub 4}. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Assessment of Automotive Coatings Used on Different Metallic Substrates

    Directory of Open Access Journals (Sweden)

    W. Bensalah

    2014-01-01

    Full Text Available Four epoxy primers commonly used in the automotive industry were applied by gravity pneumatic spray gun over metallic substrates, specifically, steel, electrogalvanized steel, hot-dip galvanized steel, and aluminum. A two-component polyurethane resin was used as topcoat. To evaluate the performance of the different coating systems, the treated panels were submitted to mechanical testing using Persoz hardness, impact resistance, cupping, lattice method, and bending. Tribological properties of different coating systems were conducted using pin on disc machine. Immersion tests were carried out in 5% NaCl and immersion tests in 3% NaOH solutions. Results showed which of the coating systems is more suitable for each substrate in terms of mechanical, tribological, and anticorrosive performance.

  3. Excimer laser texturing of natural composite polymer surfaces for studying cell-to-substrate specific response

    Energy Technology Data Exchange (ETDEWEB)

    Dinca, V., E-mail: dincavalentina@yahoo.com [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, Magurele, Bucharest (Romania); Alloncle, P.; Delaporte, P. [Aix-Marseille University, CNRS, LP3 Laboratory, Campus de Luminy, 13288 Marseille (France); Ion, V. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, Magurele, Bucharest (Romania); Faculty of Physics, University of Bucharest, 077125 Magurele (Romania); Rusen, L.; Filipescu, M. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, Magurele, Bucharest (Romania); Mustaciosu, C. [Horia Hulubei National Institute of Physics and Nuclear Engineering – IFIN HH, Magurele, Bucharest (Romania); Luculescu, C.; Dinescu, M. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, Magurele, Bucharest (Romania)

    2015-10-15

    Highlights: • Roughness gradients are obtained in one step by applying single laser pulses and sample tilting. • BSA protein and cell dependence behavior onto gradient characteristics was studied. • The degradation of the samples by lysozyme was correlated to its ability to access the textured area. - Abstract: Surface modifications of biocompatible materials are among the main factors used for enhancing and promoting specific cellular activities (e.g. spreading, adhesion, migration, and differentiation) for various types of medical applications such as implants, microfluidic devices, or tissue engineering scaffolds. In this work an excimer laser at 193 nm was used to fabricate chitosan–collagen roughness gradients. The roughness gradients were obtained in one step by applying single laser pulses and sample tilting. Fourier transform infrared spectroscopy measurements, atomic force microscopy (AFM), scanning electron microscopy (SEM), and spectro-ellipsometry (SE) were used for sample characterization. The goal is to determine the optimal morpho-chemical characteristics of these structures for in vitro tailoring of protein adsorption and cell behavior. The response induced by the roughness gradient onto various cell lines (i.e. L 929 fibroblasts, HEP G2 hepatocytes, OLN 93 oligodendrocytes, M63 osteoblasts) and bovine serum albumin (BSA) protein absorption was investigated.

  4. Metal-coordinating substrate analogs as inhibitors of metalloenzymes.

    Science.gov (United States)

    Holmquist, B; Vallee, B L

    1979-01-01

    A group of active-site metal coordinating inhibitors of zinc proteases (carboxypeptidase A, thermolysin, Bacillus cereus neutral protease, and angiotensin-converting enzyme) have been synthesized and their properties investigated. Their general structures are R-SH and R-NH-PO2(O phi)H, where-S- or -O- serve as metal ligands and R refers to an amino acid or peptide group designed to interact with substrate recognition sites. These inhibitors can be extremely potent; thus, N-(2-mercaptoacetyl)-D-phenylalanine, e.g., inhibits carboxypeptidase A with a Kiapp of 2.2 x 10(-7) M. The spectral response of cobalt(II)-substituted thermolysin or carboxypeptidase A to the sulfur-containing inhibitors signals the direct interaction of the mercaptan with the metal. An S leads to Co(II) charge transfer band is generated near 340 nm and is detected by absorption, circular dichroism, and magnetic circular dichroism. The cobalt(II) spectra indicate both inner sphere coordination with sulfur and 4-coordination in the enzyme-inhibitor complex. Thus, the metal undergoes a simple substitution reaction, the inhibitor most likely displacing water at the fourth coordination site. PMID:230502

  5. Influence of Femtosecond Laser Parameters and Environment on Surface Texture Characteristics of Metals and Non-Metals - State of the Art

    Science.gov (United States)

    Bharatish, A.; Soundarapandian, S.

    2018-04-01

    Enhancing the surface functionality by ultrashort pulsed laser texturing has received the considerable attention from researchers in the past few decades. Femtosecond lasers are widely adopted since it provides high repeatability and reproducibility by minimizing the heat affected zone (HAZ) and other collateral damages to a great extent. The present paper reports some recent studies being made worldwide on femtosecond laser surface texturing of metals, ceramics, polymers, semiconductors, thinfilms and advanced nanocomposites. It presents the state of the art knowledge in femtosecond laser surface texturing and the potential of this technology to improve properties in terms of biological, tribological and wetting performance. Since the texture quality and functionality are enhanced by the proper selection of appropriate laser parameters and ambient conditions for individual application, reporting the influence of laser parameters on surface texture characteristics assume utmost importance.

  6. COATING OF POLYMERIC SUBSTRATE CATALYSTS ON METALLIC SURFACES

    Directory of Open Access Journals (Sweden)

    H. HOSSEINI

    2010-12-01

    Full Text Available This article presents results of a study on coating of a polymeric substrate ca-talyst on metallic surface. Stability of coating on metallic surfaces is a proper specification. Sol-gel technology was used to synthesize adhesion promoters of polysilane compounds that act as a mediator. The intermediate layer was coated by synthesized sulfonated polystyrene-divinylbenzene as a catalyst for production of MTBE in catalytic distillation process. Swelling of catalyst and its separation from the metal surface was improved by i increasing the quantity of divinylbenzene in the resin’s production process and ii applying adhesion pro¬moters based on the sol-gel process. The rate of ethyl silicate hydrolysis was intensified by increasing the concentration of utilized acid while the conden¬sation polymerization was enhanced in the presence of OH–. Sol was formed at pH 2, while the pH should be 8 for the formation of gel. By setting the ratio of the initial concentrations of water to ethyl silicate to 8, the gel formation time was minimized.

  7. Metal oxide films on glass and steel substrates

    CERN Document Server

    Sohi, A M

    1987-01-01

    in the pH8 electrolyte supports the view that the rate limiting reduction reaction is possibly oxygen (or water) reduction although some contribution from an organic 'impurity' cannot be ruled out. Coatings of Fe sub 3 O sub 4 on mild steel have been prepared by CVD using pneumatic spraying techniques and the corrosion behaviour of coated electrodes in organic-phosphate electrolyte (pH8) has been examined. A variety of thin (10-1000nm) metal oxide films have been deposited on flat glass substrates by the pyrolysis of an aerosol of metal acetylacetonates in a suitable carrier. The optical characteristics and thickness of the films have been measured and particular interest has centered on the use of a novel pin on disc apparatus to measure the physical durability of such thin films. Characteristic friction/penetration force traces have been established for 1st Series transition metal oxide films and some ranking in terms of 'hardness' established. The use of SnO sub 2 - coated glass for electrodes in a light m...

  8. In vitro tensile strength of luting cements on metallic substrate.

    Science.gov (United States)

    Orsi, Iara A; Varoli, Fernando K; Pieroni, Carlos H P; Ferreira, Marly C C G; Borie, Eduardo

    2014-01-01

    The aim of this study was to determine the tensile strength of crowns cemented on metallic substrate with four different types of luting agents. Twenty human maxillary molars with similar diameters were selected and prepared to receive metallic core castings (Cu-Al). After cementation and preparation the cores were measured and the area of crown's portion was calculated. The teeth were divided into four groups based on the luting agent used to cement the crowns: zinc phosphate cement; glass ionomer cement; resin cement Rely X; and resin cement Panavia F. The teeth with the crowns cemented were subjected to thermocycling and later to the tensile strength test using universal testing machine with a load cell of 200 kgf and a crosshead speed of 0.5 mm/min. The load required to dislodge the crowns was recorded and converted to MPa/mm(2). Data were subjected to Kruskal-Wallis analysis with a significance level of 1%. Panavia F showed significantly higher retention in core casts (3.067 MPa/mm(2)), when compared with the other cements. Rely X showed a mean retention value of 1.877 MPa/mm(2) and the zinc phosphate cement with 1.155 MPa/mm(2). Glass ionomer cement (0.884 MPa/mm(2)) exhibited the lowest tensile strength value. Crowns cemented with Panavia F on cast metallic posts and cores presented higher tensile strength. The glass ionomer cement showed the lowest tensile strength among all the cements studied.

  9. Microscopic mechanisms of graphene electrolytic delamination from metal substrates

    International Nuclear Information System (INIS)

    Fisichella, G.; Di Franco, S.; Roccaforte, F.; Giannazzo, F.; Ravesi, S.

    2014-01-01

    In this paper, hydrogen bubbling delamination of graphene (Gr) from copper using a strong electrolyte (KOH) water solution was performed, focusing on the effect of the KOH concentration (C KOH ) on the Gr delamination rate. A factor of ∼10 decrease in the time required for the complete Gr delamination from Cu cathodes with the same geometry was found increasing C KOH from ∼0.05 M to ∼0.60 M. After transfer of the separated Gr membranes to SiO 2 substrates by a highly reproducible thermo-compression printing method, an accurate atomic force microscopy investigation of the changes in Gr morphology as a function of C KOH was performed. Supported by these analyses, a microscopic model of the delamination process has been proposed, where a key role is played by graphene wrinkles acting as nucleation sites for H 2 bubbles at the cathode perimeter. With this approach, the H 2 supersaturation generated at the electrode for different electrolyte concentrations was estimated and the inverse dependence of t d on C KOH was quantitatively explained. Although developed in the case of Cu, this analysis is generally valid and can be applied to describe the electrolytic delamination of graphene from several metal substrates.

  10. Coatings of metal substrates assisted by laser radiation

    Directory of Open Access Journals (Sweden)

    Caudevilla, H.

    1998-04-01

    Full Text Available In this contribution, a new way of obtaining ceramic coatings is presented. This method uses precursor suspensions, settled on substrates and in-situ pyrolised with a laser. Different deposition techniques of the ceramic precursors have been tested in order to obtain a homogeneous distribution on the metal substrate before the laser treatment.

    La combinación de recubrimientos utilizando disoluciones de precursores metálicos con la pirólisis asistida por láser, permite obtener una gran diversidad de recubrimientos sobre sustratos de muy distinta naturaleza. Se han realizado estudios, tanto con disoluciones poliméricas, como con disoluciones de tipo sol-gel y pastas obtenidas con técnicas similares, depositadas utilizando métodos convencionales de inmersión y atomización previa a la pirólisis asistida por láser, así como simultánea. En este trabajo se presenta un resumen de los resultados más significativos obtenidos en la realización de recubrimientos sobre sustratos metálicos y cerámicos.

  11. Artificial in-plane ordering of textured YBa2Cu3O(7-x) films deposited on polycrystalline yttria-stabilized zirconia substrates

    Science.gov (United States)

    Harshavardhan, K. S.; Rajeswari, M.; Hwang, D. M.; Chen, C. Y.; Sands, T. D.; Venkatesan, T.; Tkaczyk, J. E.; Lay, K. W.; Safari, A.; Johnson, L.

    1992-12-01

    Anisotropic surface texturing of the polycrystalline yttria-stabilized zirconia substrates, prior to YBa2Cu3O(7-x) film deposition, is shown to promote in-plane (basal plane) ordering of the film growth in addition to the c-axis texturing. The Jc's of the films in the weak-link-dominated low-field regime are enhanced considerably, and this result is attributed to the reduction of weak links resulting from a reduction in the number of in-plane large-angle grain boundaries.

  12. Extrapolating Dynamic Leidenfrost Principles to Metallic Nanodroplets on Asymmetrically Textured Surfaces.

    Science.gov (United States)

    Horne, Joseph E; Lavrik, Nickolay V; Terrones, Humberto; Fuentes-Cabrera, Miguel

    2015-06-30

    In an effort to enhance our knowledge on how to control the movement of metallic nanodroplets, here we have used classical molecular dynamics simulations to investigate whether Cu nanostructures deposited on nanopillared substrates can be made to jump at desired angles. We find that such control is possible, especially for Cu nanostructures that are symmetric; for asymmetric nanostructures, however, control is more uncertain. The work presented here borrows ideas from two seemingly different fields, metallic droplets and water droplets in the dynamic Leidenfrost regime. Despite the differences in the respective systems, we find common ground in their behavior on nanostructured surfaces. Due to this, we suggest that the ongoing research in Leidenfrost droplets is a fertile area for scientists working on metallic nanodroplets.

  13. Deposition and Characterization of Thin Films on Metallic Substrates

    Science.gov (United States)

    Gatica, Jorge E.

    2005-01-01

    on aluminum and other metallic substrates.

  14. Geology mineralogy, structure and texture of Agh-Otagh base- precious metal mineralization (North Takab

    Directory of Open Access Journals (Sweden)

    Nahid Rahmati

    2017-07-01

    Full Text Available The Agh-Otagh mineralization area in the north of Takab, was formed within the andesistic tuffaceous rocks of the Oligo- Miocene age. Mineralization include polymetallic (Cu-Pb-Zn-Au-Ag quartz veins and silicified zones, which occurred as breccia and vein- veinlets with comb, cockade and disseminated textures. Chalcopyrite, pyrite, galena and sphalerite are common ore minerals. Alteration zones consist of silicification, sericitization, argillitic, propelitic and carbonatization. Cu-Au mineralization is associated with silicification and sericitization. Analytical results of the samples from the ore- bearing quartz veins and the silicified zones indicate that the highest grade for Au is 664 ppb (ave.181 ppb. The highest and the average grades for Ag, Cu, Pb, and Zn are 120 ppm (300 ppm, 1.3 % (0.38 %, 5.5 % (0.06 % and 4.5 % (0.28 %, respectively. The investigations indicate that the Agh-Otagh mineralization was formed in four stages. In the first stage or the pre-mineralization stage, the host rock, as a result of hydrothermal process, underwent brecciation and some quartz veins and siliceous cap were formed. In the second stage or the mineralization stage the sulfide minerals formed within the quartz veins and silicification zones developed at the third stage, some unmineralized quartz, barite and carbonate vein- veinlets crosscut the previous stages. The last stage of mineralization related to supergene processes. Based on geological, mineralogical, alteration, structural and textural evidences, the Agh-Otagh base- precious metal mineralization is similar to the medium sulfidation epithermal deposits.

  15. When lithography meets self-assembly: a review of recent advances in the directed assembly of complex metal nanostructures on planar and textured surfaces

    Science.gov (United States)

    Hughes, Robert A.; Menumerov, Eredzhep; Neretina, Svetlana

    2017-07-01

    One of the foremost challenges in nanofabrication is the establishment of a processing science that integrates wafer-based materials, techniques, and devices with the extraordinary physicochemical properties accessible when materials are reduced to nanoscale dimensions. Such a merger would allow for exacting controls on nanostructure positioning, promote cooperative phenomenon between adjacent nanostructures and/or substrate materials, and allow for electrical contact to individual or groups of nanostructures. With neither self-assembly nor top-down lithographic processes being able to adequately meet this challenge, advancements have often relied on a hybrid strategy that utilizes lithographically-defined features to direct the assembly of nanostructures into organized patterns. While these so-called directed assembly techniques have proven viable, much of this effort has focused on the assembly of periodic arrays of spherical or near-spherical nanostructures comprised of a single element. Work directed toward the fabrication of more complex nanostructures, while still at a nascent stage, has nevertheless demonstrated the possibility of forming arrays of nanocubes, nanorods, nanoprisms, nanoshells, nanocages, nanoframes, core-shell structures, Janus structures, and various alloys on the substrate surface. In this topical review, we describe the progress made in the directed assembly of periodic arrays of these complex metal nanostructures on planar and textured substrates. The review is divided into three broad strategies reliant on: (i) the deterministic positioning of colloidal structures, (ii) the reorganization of deposited metal films at elevated temperatures, and (iii) liquid-phase chemistry practiced directly on the substrate surface. These strategies collectively utilize a broad range of techniques including capillary assembly, microcontact printing, chemical surface modulation, templated dewetting, nanoimprint lithography, and dip-pen nanolithography and

  16. Superconducting and structural properties of plasma sprayed YBaCuO layers deposited on metallic substrates

    NARCIS (Netherlands)

    Hemmes, Herman K.; Jäger, D; Smithers, M.A.; Smithers, M.; van der Veer, J.; van der Veer, J.M.; Stover, D.; Rogalla, Horst

    1993-01-01

    The properties of plasma sprayed Y-Ba-Cu-O coatings deposited on metallic substrates are studied. Stainless steel, nickel steels and pure nickel are used as substrate. Y-Ba-Cu-O deposited on stainless steel and nickel steel reacts with the substrate. This interaction can be suppressed by using an

  17. Ultrasonic measurement of through-thickness stress gradients in textured sheet metals

    International Nuclear Information System (INIS)

    Man Chising; Li Jianbo; Fan Xingyan; Lu Weiyang

    2000-01-01

    The objective of this investigation is to explore the possibility of using the dispersion of high-frequency Rayleigh waves for the evaluation of through-thickness stress gradients at the surface of metal sheets. We consider an orthorhombic sheet of cubic metal with through-thickness inhomogeneities in stress and texture, and adopt a coordinate system under which the rolling (RD), transverse (TD), and normal direction (ND) of the sheet are taken as the 1-, 2-, and 3-direction, respectively. We restrict our attention to the special case where only the stress components T 11 (x 3 ) and T 22 (x 3 ) in the sheet are nonzero, and consider only Rayleigh waves of sufficiently high frequency for which the sheet can be taken as the half-space x 3 ≥0. For Rayleigh waves of two different frequencies (with wave numbers k 1 and k k 2 respectively) propagating on the same wave path along either RD or TD, we appeal to an analysis of J. Li and Man to obtain a high-frequency asymptotic formula which gives the relative change in time-of-flight Δt/t 0 as (1/k 1 -1/k 2 ) times a linear combination of the derivatives T 11 ' (0), T 22 ' (0), W 4m0 ' (0)(m=0,2,4) and W 6m0 (0)(m=0,2,4,6) at the surface are ascertained and the material constants in the acoustoelastic consitutive equation of this polycrystal are known. An experiment was performed on an AA7075-T651 aluminum alloy beam, in which Δt/t 0 was measured for various values of T 11 (0) and T 11 ' (0) produced by beam bending (with (T 22 ≡0). The relevant texture coefficients of the beam were measured by X-ray diffraction. To obtain specific predictions from the aforementioned symptotic formula, we replace the material constants of the sample by their counterparts predicted for polycrystalline (pure) aluminum by the Man-Paroni model. The predictions and Δt/t 0 are then compared with the experimental results

  18. Dynamics of a metal overlayer on metallic substrates: High temperature effects

    International Nuclear Information System (INIS)

    Rahman, T.S.; Black, J.E.; Tian, Zeng Ju

    1992-01-01

    We have explored the structure and the dynamics of a bimetallic system consisting of a hexagonal (almost) overlayer of Ag on a square lattice (Ni(100) and Cu(100)), as a function of the surface temperature. In each case the structure is ''nearly'' incommensurate giving rise to a low frequency Goldstone mode. Also, the overlayer atoms slosh back and forth over the substrate in a corrugated fashion. The calculated dispersion of the Ag/metal vertical mode, at room temperature, is in excellent agreement with experimental data. At higher temperatures floater atoms appear on top of the overlayer displaying a variety of cluster formations and also exchanges with the substrate atoms leading to surface disordering, interdiffusion and melting

  19. Autoradiographic techniques to determine noble metal distribution in automotive catalyst substrates

    International Nuclear Information System (INIS)

    Lange, W.H.

    1976-01-01

    The distribution of noble metals in the ceramic substrates of automotive catalytic converter systems is important to the functional characteristics of the systems. A radiotracer technique involving microtomy of bead substrate samples and autoradiography using the resultant thin sections was developed to produce detailed images of the metal distributions. The method is particularly valuable to determine the distribution of one metal in the presence of another to aid in the development of more efficient systems

  20. Deposition of highly oriented (K,Na)NbO3 films on flexible metal substrates

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Thydén, Karl; Bowen, Jacob R.

    2018-01-01

    In view of developing flexible, highly textured Pb-free piezoelectric thin films, (K,Na)NbO3 was deposited by chemical solution deposition on cube-textured Ni-W alloy substrates. After heat treatment, a strong (001)pc out-of-plane preferential orientation is created in the (K,Na)NbO3 layer, which...

  1. Effect of surface shear on cube texture formation in heavy cold-rolled Cu-45 at%Ni alloy substrates

    DEFF Research Database (Denmark)

    Tian, Hui; Suo, Hongli; Liang, Yaru

    2015-01-01

    Two types of Cu-45 at%Ni alloy thin tapes with and without surface shear were obtained by different heavy cold rolling processes. The deformation and recrystallization textures of the two tapes were thoroughly investigated by electron back scattering diffraction technique. The results showed...... that a shear texture mainly covered the surface of the heavy deformed tapes because of the fraction between the surface of rolling mills and the thin tapes when the rolling force strongly reduced at high strain, which significantly reduced the fraction of rolling texture on the surface of the Cu-45at %Ni alloy...

  2. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by austenitic filler metal

    International Nuclear Information System (INIS)

    Eghlimi, Abbas; Shamanian, Morteza; Eskandarian, Masoomeh; Zabolian, Azam; Szpunar, Jerzy A.

    2015-01-01

    The evolution of microstructure and texture across an as-welded dissimilar UNS S32750 super duplex/UNS S30403 austenitic stainless steel joint welded by UNS S30986 (AWS A5.9 ER309LMo) austenitic stainless steel filler metal using gas tungsten arc welding process was evaluated by optical micrography and EBSD techniques. Due to their fabrication through rolling process, both parent metals had texture components resulted from deformation and recrystallization. The weld metal showed the highest amount of residual strain and had large austenite grain colonies of similar orientations with little amounts of skeletal ferrite, both oriented preferentially in the < 001 > direction with cub-on-cube orientation relationship. While the super duplex stainless steel's heat affected zone contained higher ferrite than its parent metal, an excessive grain growth was observed at the austenitic stainless steel's counterpart. At both heat affected zones, austenite underwent some recrystallization and formed twin boundaries which led to an increase in the fraction of high angle boundaries as compared with the respective base metals. These regions showed the least amount of residual strain and highest amount of recrystallized austenite grains. Due to the static recrystallization, the fraction of low degree of fit (Σ) coincident site lattice boundaries, especially Σ3 boundaries, was increased in the austenitic stainless steel heat affected zone, while the formation of subgrains in the ferrite phase increased the content of < 5° low angle boundaries at that of the super duplex stainless steel. - Graphical abstract: Display Omitted - Highlights: • Extensive grain growth in the HAZ of austenitic stainless steel was observed. • Intensification of < 100 > orientated grains was observed adjacent to both fusion lines. • Annealing twins with Σ3 CSL boundaries were formed in the austenite of both HAZ. • Cub-on-cube OR was observed between austenite and ferrite in the weld

  3. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by austenitic filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada)

    2015-08-15

    The evolution of microstructure and texture across an as-welded dissimilar UNS S32750 super duplex/UNS S30403 austenitic stainless steel joint welded by UNS S30986 (AWS A5.9 ER309LMo) austenitic stainless steel filler metal using gas tungsten arc welding process was evaluated by optical micrography and EBSD techniques. Due to their fabrication through rolling process, both parent metals had texture components resulted from deformation and recrystallization. The weld metal showed the highest amount of residual strain and had large austenite grain colonies of similar orientations with little amounts of skeletal ferrite, both oriented preferentially in the < 001 > direction with cub-on-cube orientation relationship. While the super duplex stainless steel's heat affected zone contained higher ferrite than its parent metal, an excessive grain growth was observed at the austenitic stainless steel's counterpart. At both heat affected zones, austenite underwent some recrystallization and formed twin boundaries which led to an increase in the fraction of high angle boundaries as compared with the respective base metals. These regions showed the least amount of residual strain and highest amount of recrystallized austenite grains. Due to the static recrystallization, the fraction of low degree of fit (Σ) coincident site lattice boundaries, especially Σ3 boundaries, was increased in the austenitic stainless steel heat affected zone, while the formation of subgrains in the ferrite phase increased the content of < 5° low angle boundaries at that of the super duplex stainless steel. - Graphical abstract: Display Omitted - Highlights: • Extensive grain growth in the HAZ of austenitic stainless steel was observed. • Intensification of < 100 > orientated grains was observed adjacent to both fusion lines. • Annealing twins with Σ3 CSL boundaries were formed in the austenite of both HAZ. • Cub-on-cube OR was observed between austenite and ferrite in the weld

  4. Through-substrate via and redistribution layer with metal paste

    NARCIS (Netherlands)

    Roozeboom, F.; Grunsven, E.C.E. van; Sanders, F.H.M.; Burghoorn, M.M.A.

    2013-01-01

    A semiconductor device and a method for manufacturing such semiconductor device for use in a stacked configuration of the semiconductor device are disclosed. The semiconductor device includes a substrate including at least part of an electronic circuit provided at a first side thereof. The substrate

  5. Changes in element availability induced by sterilization in heavy metal contaminated substrates: A comprehensive study.

    Science.gov (United States)

    Krauße, Thomas; Schütze, Eileen; Phieler, René; Fürst, David; Merten, Dirk; Büchel, Georg; Kothe, Erika

    2017-11-10

    Microbiome analyses of soils and microcosm experiments depend on conditions that include sterilization in order to perform experimental manipulation of microbial communities. Still, they should represent conditions close to nature. When using metal contaminated soils, sterilization methods might alter metal availability. Here, four typical metal contaminated substrates were analyzed, representing different contamination histories and soil types. They included two very poor substrates, as they are often found at metal contaminated sites. The low contents in organic carbon and nitrogen as well as two substrates with slightly higher nutrient availability were used to perform a comprehesive study for element availability changes induced by sterilization. Autoclaving, dry heat or gamma raγ sterilization were applied and compared to a non-treated control. The sterile substrates were analyzed using sequential extraction to account for different associations of the elements. Metals forming specific (hydro)oxide layers were specifically analyzed since they in turn may also impact other metals or ions. In addition, (heavy) metals and (micro)nutrients were analyzed for changes in speciation. The effects of autoclaving (wet heat) was found acceptable, while γ-ray irradiation did show unexpected changes in metal associations, especially for one substrate. Dry heat changed metal availability to the highest degree. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. The coalescence of heterogeneous liquid metal on nano substrate

    Science.gov (United States)

    Wang, Long; Li, Yifan; Zhou, Xuyan; Li, Tao; Li, Hui

    2017-06-01

    Molecular dynamics simulation has been performed to study the asymmetric coalescence of heterogeneous liquid metal on graphene. Simulation results show that the anomalies in the drop coalescence is mainly caused by the wettability of heterogeneous liquid metal. The silver atoms incline to distribute on the outer layer of the gold and copper droplets, revealing that the structure is determined by the interaction between different metal atoms. The coalescence and fusion of heterogeneous liquid metal drop can be predicted by comparing the wettability and the atomic mass of metallic liquid drops, which has important implications in the industrial application such as ink-jet printing and metallurgy.

  7. Synthesis of organolanthanides by metal addition on insaturated substrates in ether and reactivity

    International Nuclear Information System (INIS)

    Olivier, H.

    1988-01-01

    The aim of the study is the extension to rare earths of the synthesis, well known for alkaline or alkaline earth metals, by direct metal addition to insaturated substrates in ether and where the metal is directly bound to carbon. A definition of formation conditions and affinity rules is attempled, both with substrates (essentially aromatic hydrocarbons and ketones) and with metals: Yb, Sm, Ce, Nd and others. The nature of obtained products by reaction of electrophiles on synthetised organometallics, allows investigations specific reactivity and structure. Potential catalytic transformation of olefins is precised [fr

  8. Intercalation of metals and silicon at the interface of epitaxial graphene and its substrates

    International Nuclear Information System (INIS)

    Huang Li; Xu Wen-Yan; Que Yan-De; Mao Jin-Hai; Meng Lei; Pan Li-Da; Li Geng; Wang Ye-Liang; Du Shi-Xuan; Gao Hong-Jun; Liu Yun-Qi

    2013-01-01

    Intercalations of metals and silicon between epitaxial graphene and its substrates are reviewed. For metal intercalation, seven different metals have been successfully intercalated at the interface of graphene/Ru(0001) and form different intercalated structures. Meanwhile, graphene maintains its original high quality after the intercalation and shows features of weakened interaction with the substrate. For silicon intercalation, two systems, graphene on Ru(0001) and on Ir(111), have been investigated. In both cases, graphene preserves its high quality and regains its original superlative properties after the silicon intercalation. More importantly, we demonstrate that thicker silicon layers can be intercalated at the interface, which allows the atomic control of the distance between graphene and the metal substrates. These results show the great potential of the intercalation method as a non-damaging approach to decouple epitaxial graphene from its substrates and even form a dielectric layer for future electronic applications. (topical review - low-dimensional nanostructures and devices)

  9. Copper Metallic Substrates for High Temperature Superconducting Coated Conductors

    National Research Council Canada - National Science Library

    Yust, Nicholas A; Nekkanti, Rama; Brunke, Lyle B; Srinivasan, Raghavan; Barnes, Paul N

    2006-01-01

    ...) coated conductor applications. A comparison is made between Cu substrates fabricated by reverse cold rolling followed by recrystallization, from stock materials that were obtained in the form of extruded rod and rolled plate...

  10. Long Spin-Relaxation Times in a Transition-Metal Atom in Direct Contact to a Metal Substrate.

    Science.gov (United States)

    Hermenau, Jan; Ternes, Markus; Steinbrecher, Manuel; Wiesendanger, Roland; Wiebe, Jens

    2018-03-14

    Long spin-relaxation times are a prerequisite for the use of spins in data storage or nanospintronics technologies. An atomic-scale solid-state realization of such a system is the spin of a transition-metal atom adsorbed on a suitable substrate. For the case of a metallic substrate, which enables the direct addressing of the spin by conduction electrons, the experimentally measured lifetimes reported to date are on the order of only hundreds of femtoseconds. Here, we show that the spin states of iron atoms adsorbed directly on a conductive platinum substrate have a surprisingly long spin-relaxation time in the nanosecond regime, which is comparable to that of a transition metal atom decoupled from the substrate electrons by a thin decoupling layer. The combination of long spin-relaxation times and strong coupling to conduction electrons implies the possibility to use flexible coupling schemes to process the spin information.

  11. Long Spin-Relaxation Times in a Transition-Metal Atom in Direct Contact to a Metal Substrate

    Science.gov (United States)

    Hermenau, Jan; Ternes, Markus; Steinbrecher, Manuel; Wiesendanger, Roland; Wiebe, Jens

    2018-03-01

    Long spin relaxation times are a prerequisite for the use of spins in data storage or nanospintronics technologies. An atomic-scale solid-state realization of such a system is the spin of a transition metal atom adsorbed on a suitable substrate. For the case of a metallic substrate, which enables directly addressing the spin by conduction electrons, the experimentally measured lifetimes reported to date are on the order of only hundreds of femtoseconds. Here, we show that the spin states of iron atoms adsorbed directly on a conductive platinum substrate have an astonishingly long spin relaxation time in the nanosecond regime, which is comparable to that of a transition metal atom decoupled from the substrate electrons by a thin decoupling layer. The combination of long spin relaxation times and strong coupling to conduction electrons implies the possibility to use flexible coupling schemes in order to process the spin-information.

  12. Recent Developments of Flexible CdTe Solar Cells on Metallic Substrates: Issues and Prospects

    OpenAIRE

    M. M. Aliyu; M. A. Islam; N. R. Hamzah; M. R. Karim; M. A. Matin; K. Sopian; N. Amin

    2012-01-01

    This study investigates the key issues in the fabrication of CdTe solar cells on metallic substrates, their trends, and characteristics as well as effects on solar cell performance. Previous research works are reviewed while the successes, potentials, and problems of such technology are highlighted. Flexible solar cells offer several advantages in terms of production, cost, and application over glass-based types. Of all the metals studied as substrates for CdTe solar cells, molybdenum appears...

  13. Physical masking process for integrating micro metallic structures on polymer substrate

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard

    2009-01-01

    . The current study shows a novel approach for fabricating thin micro metallic structures on polymer substrates using a simple physical mask and a PVD equipment. The new process involves fewer process steps, it is cost effective and suitable for high volume industrial production. Current study suggests...... that physical masking process in combination with PVD can be a cost effective alternative to photolithography when thin metallic structures on a polymers substrate are concerned....

  14. Dry texturing of solar cells

    Science.gov (United States)

    Sopori, Bhushan L.

    1994-01-01

    A textured backside of a semiconductor device for increasing light scattering and absorption in a semiconductor substrate is accomplished by applying infrared radiation to the front side of a semiconductor substrate that has a metal layer deposited on its backside in a time-energy profile that first produces pits in the backside surface and then produces a thin, highly reflective, low resistivity, epitaxial alloy layer over the entire area of the interface between the semiconductor substrate and a metal contact layer. The time-energy profile includes ramping up to a first energy level and holding for a period of time to create the desired pit size and density and then rapidly increasing the energy to a second level in which the entire interface area is melted and alloyed quickly. After holding the second energy level for a sufficient time to develop the thin alloy layer over the entire interface area, the energy is ramped down to allow epitaxial crystal growth in the alloy layer. The result is a textured backside an optically reflective, low resistivity alloy interface between the semiconductor substrate and the metal electrical contact layer.

  15. Epitaxial growth of CdTe thin film on cube-textured Ni by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Gaire, C.; Rao, S.; Riley, M.; Chen, L.; Goyal, A.; Lee, S.; Bhat, I.; Lu, T.-M.; Wang, G.-C.

    2012-01-01

    Single crystal-like CdTe thin film has been grown by metalorganic chemical vapor deposition on cube-textured Ni(100) substrate. Using X-ray pole figure measurements we observed the epitaxial relationship of {111} CdTe //{001} Ni with [11 ¯ 0] CdTe //[010] Ni and [112 ¯ ] CdTe //[100] Ni . The 12 diffraction peaks in the (111) pole figure of CdTe film and their relative positions with respect to the four peak positions in the (111) pole figure of Ni substrate are consistent with four equivalent orientational domains of CdTe with three to four superlattice match of about 1.6% in the [11 ¯ 0] direction of CdTe and the [010] direction of Ni. The electron backscattered diffraction images show that the CdTe domains are 30° oriented from each other. These high structural quality films may find applications in low cost optoelectronic devices.

  16. Inductive Cross Shaped Metal Meshes in Silicon Substrate

    National Research Council Canada - National Science Library

    Sternberg, O; Moller, K. D; Grebel, H; Stewart, K. P; Henry, R. M

    2002-01-01

    .... The Micro-Stripes program was used for the calculation of resonance wavelength and width of resonance of cross shaped metal meshes and best- fit formulas were developed for the presentation of the data...

  17. Interfacial Structure and Photocatalytic Activity of Magnetron Sputtered TiO2 on Conducting Metal Substrates

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Petit, Jean-Pierre; Mermoux, Michel

    2014-01-01

    The photocatalytic behavior of magnetron sputtered anatase TiO2 coatings on copper, nickel, and gold was investigated with the aim of understanding the effect of the metallic substrate and coating-substrate interface structure. Stoichiometry and nanoscale structure of the coating were investigated...... using X-ray diffraction, Raman spectroscopy, atomic force microscope, and scanning and transmission electron microscopy. Photocatalytic behavior of the coating was explored by using optical spectrophotometry and electrochemical methods via photovoltage, photocurrent, and scanning kelvin probe microscopy...... measurements. The nature of the metal substrate and coating-substrate interface had profound influence on the photocatalytic behavior. Less photon energy was required for TiO2 excitation on a nickel substrate, whereas TiO2 coating on copper showed a higher band gap attributed to quantum confinement. However...

  18. Preparation of Ag superhydrophobic surface on metal substrates

    Science.gov (United States)

    Li, J. Y.; Lu, S. X.; Xu, W. G.; Duan, Y. Q.; Yang, X. C.; Cheng, Y. Y.; He, G.; Cui, S.

    2018-01-01

    In this work, the facile approaches are developed for preparation the Ag superhydrophobic surfaces (SHSs) on zinc (Zn), copper (Cu) and aluminium (Al) substrates. The water contact angles (WCAs) of the Ag SHSs on Zn, Cu and Al substrates are 167°, 165° and 154°, respectively. Furthermore, the water sliding angle (WSA) of each surface is less than 1°. The morphology and chemical composition of the samples are characterized using scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). The as-prepared three kinds of SHSs possess the self-cleaning performance, which can quickly take the chalk away when the water droplets fall down the SHSs. In addition, the superhydrophobicity of the SHSs can well maintain after exposure to the air for 6 months, indicating that the surfaces can sustain good stability.

  19. MM&T-Ceramic Metal Substrates for Hybrid Electronics: Handbook

    Science.gov (United States)

    1984-01-01

    Copper EL-P0II-2 Alloy 42 EK5/EK6 303 Stainless Steel Steel- Invar -Steel (a) FERRO-ECA Electronics Company 3130 West 22nd Street, P.O. Box 8305...AND ADDRESS Harry Diamond Laboratories 2800 Powder Mill Road Adelphi, MD 20783 12. REPORT DATE January 1984 13. NUMBER OF PAGES 14...PLASMA-SPRAYED CERAMIC ON METAL Metal Coating Results of Coating Effect of 850oC Thkr Film Profile Alloy #2 105SF 334F LINDE A Good Good

  20. ZnO buffer layer for metal films on silicon substrates

    Science.gov (United States)

    Ihlefeld, Jon

    2014-09-16

    Dramatic improvements in metallization integrity and electroceramic thin film performance can be achieved by the use of the ZnO buffer layer to minimize interfacial energy between metallization and adhesion layers. In particular, the invention provides a substrate metallization method utilizing a ZnO adhesion layer that has a high work of adhesion, which in turn enables processing under thermal budgets typically reserved for more exotic ceramic, single-crystal, or metal foil substrates. Embodiments of the present invention can be used in a broad range of applications beyond ferroelectric capacitors, including microelectromechanical systems, micro-printed heaters and sensors, and electrochemical energy storage, where integrity of metallized silicon to high temperatures is necessary.

  1. Methods of making textured catalysts

    Science.gov (United States)

    Werpy, Todd [West Richland, WA; Frye, Jr., John G.; Wang, Yong [Richland, WA; Zacher, Alan H [Kennewick, WA

    2010-08-17

    A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.

  2. Removing paint from a metal substrate using a flattened top laser

    International Nuclear Information System (INIS)

    Shi Shu-Dong; Li Wei; Du Peng; Wang Meng; Song Feng; Liu Shu-Jing; Chen Nian-Jiang; Zhao Hong; Yang Wen-Shi

    2012-01-01

    In this paper, we investigate laser cleaning using a flattened top laser to remove paint coating from a metal substrate. Under the irradiation of a flattened top laser, the coating paint of the metal substrate can be removed efficiently by laser induced ablation, stress, and displacement force. The temperature distribution, stress, and displacement are calculated in the coating layer and substrate using finite element analysis. The effects of a Gaussian laser and a flattened top laser and the results of different diameters of laser spot are compared. The investigation shows that the flattened top laser can reduce the substrate damage and enhance the cleaning efficiency. This method meets the need of large area industrial cleaning applications by optimizing the flattened top laser parameters

  3. Removing paint from a metal substrate using a flattened top laser

    Science.gov (United States)

    Shi, Shu-Dong; Li, Wei; Du, Peng; Wang, Meng; Song, Feng; Liu, Shu-Jing; Chen, Nian-Jiang; Zhao, Hong; Yang, Wen-Shi

    2012-10-01

    In this paper, we investigate laser cleaning using a flattened top laser to remove paint coating from a metal substrate. Under the irradiation of a flattened top laser, the coating paint of the metal substrate can be removed efficiently by laser induced ablation, stress, and displacement force. The temperature distribution, stress, and displacement are calculated in the coating layer and substrate using finite element analysis. The effects of a Gaussian laser and a flattened top laser and the results of different diameters of laser spot are compared. The investigation shows that the flattened top laser can reduce the substrate damage and enhance the cleaning efficiency. This method meets the need of large area industrial cleaning applications by optimizing the flattened top laser parameters.

  4. Nanoparticles and modified clays influenced distribution of heavy metals fractions in a light-textured soil amended with sewage sludges.

    Science.gov (United States)

    Feizi, Morteza; Jalali, Mohsen; Renella, Giancarlo

    2018-02-05

    We comparatively assessed the effect of modified clays (MCs) (zeolite and bentonite) and nanoparticles (NPs) (ZnO and MgO) on the distribution of cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn) fractions in a light-textured soil amended with five sewage sludges (SSs) differed in chemical properties during a 92-day incubation experiment in the laboratory. Results indicated that presence of adsorbents and incubation time were critical parameters in stabilizing metals in SS-amended soil. The adsorbents that significantly decreased the easily soluble and exchangeable of metals in SS-amended soil (rate 2%) were bentonite, ZnO and MgO for Cd and Cu, ZnO and MgO for Ni, and bentonite and MgO for Zn. The calculated mobility factor of the metals at five incubation times (5, 15, 29, 57 and 92days) was found in the range of 34.7-51.8 for Cd, 16.7-20.0 for Cu, 15.0-27.7 for Ni, and 35.3-40.7 for Zn indicating a higher mobility of Cd. The addition of MCs and NPs decreased the available fraction of metals, and among them, we suggest bentonite and MgO as novel, promising and feasible adsorbents with the unique characteristics in ameliorating the toxic effects of metals by converting their form from labile to non-labile phases in the SS-amended soil. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Highly textured films of layered metal disulfide 2H-WS{sub 2}: Preparation and optoelectronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Matthaeus, A.; Ennaoui, A.; Fiechter, S. [Hahn-Meitner-Inst., Berlin (Germany)] [and others

    1997-03-01

    Highly textured films of 2H-WS{sub 2} can be obtained by sulfurization of up to 4 {micro}m thick WO{sub 3} layers in the presence of hydrogen using amorphous (quartz glass, glassy carbon) or crystalline (sapphire, Muscovite, highly oriented pyrolytic graphite) substrates. Best conditions have been found employing (00.1) oriented sapphire substrates with a 5 nm thick nickel layer interposed between substrate and oxide film (0.5 to 4 {micro}m thickness) and a reaction temperature ranging from 973 to 1,173 K. Depending on time the crystallites, oriented with their hexagonal basal planes parallel to the substrate, exhibited a lateral extension of up to 20 {micro}m and a thickness of {le}300 nm. Conductivity measurements of the films showed a p-type conductivity in the range from 0.1 to 3 {Omega}{sup {minus}1} cm{sup {minus}1} and a lateral mobility as high as 105 cm{sup 2}/V s at room temperature. The conductivity type has been confirmed by ultraviolet photoelectron and x-ray photoelectron spectroscopy which were compared with n-type single crystals. A freestanding film pealed off from a Pt coated quartz substrate and mounted on a brass holder was investigated photoelectrochemically. Using a 0.2 M Fe{sup 2+}/Fe{sup 3+} redox electrolyte in 0.5 M H{sub 2}SO{sub 4} an open-circuit voltage of {approx}100 mV and a short-circuit current of 5 mA/cm{sup 2} has been detected for the first time.

  6. Electroless deposition of metal nanoparticles on graphene with substrate-assisted techniques

    Science.gov (United States)

    Zaniewski, Anna M.; Trimble, Christie J.; Meeks, Veronica; Nemanich, Robert J.

    2015-03-01

    We present the electroless reduction of solution-based metal ions for nanoparticle deposition on a variety of substrates. The substrates include graphene-coated metals, insulators, doped semiconductors, and patterned ferroelectrics. We find that the metal ions are spontaneously reduced on a wide variety of graphene substrates, and the substrates play a large role in the nanoparticle coverage. For example, the reduction of gold chloride to gold nanoparticles on graphene/lithium niobate results in 3% nanoparticle coverage compared to 20% coverage on graphene/silicon and 60% on graphene/copper. Given that the work function of graphene is approximately 4.4eV, the Fermi level is -0.1 V vs the normal hydrogen electrode (NHE). Since the reduction potential of gold chloride is +1.002 V, the spontaneous transfer of electrons from the graphene to the metal ion is energetically favorable. However, we find substrates with similar work functions nevertheless result in varied deposition rates, which we attribute to electron availability. We also find that patterned ferrolectrics can be used as a template for patterned nanoparticle deposition, with and without graphene. This work is supported by the National Science Foundation under Grant # DMR-1206935.

  7. Topography evolution of rough-surface metallic substrates by solution deposition planarization method

    Science.gov (United States)

    Chu, Jingyuan; Zhao, Yue; Liu, Linfei; Wu, Wei; Zhang, Zhiwei; Hong, Zhiyong; Li, Yijie; Jin, Zhijian

    2018-01-01

    As an emerging technique for surface smoothing, solution deposition planarization (SDP) has recently drawn more attention on the fabrication of the second generation high temperature superconducting (2G-HTS) tapes. In our work, a number of amorphous oxide layers were deposited on electro-polished or mirror-rolled metallic substrates by chemical solution route. Topography evolution of surface defects on these two types of metallic substrates was thoroughly investigated by atomic force microscopy (AFM). It was showed that root mean square roughness values (at 50 × 50 μm2 scanning scale) on both rough substrates reduced to ∼5 nm after coating with SDP-layer. The smoothing effect was mainly attributed to decrease of the depth at grain boundary grooving on the electro-polished metallic substrate. On the mirror-rolled metallic substrates, the amplitude and frequency of the height fluctuation perpendicular to the rolling direction were gradually reduced as depositing more numbers of SDP-layer. A high Jc value of 4.17 MA cm-2 (at 77 K, s.f.) was achieved on a full stack of YBCO/CeO2/IBAD-MgO/SDP-layer/C276 sample. This study enhanced understanding of the topography evolution on the surface defects covered by the SDP-layer, and demonstrated a low-cost route for fabricating IBAD-MgO based YBCO templates with a simplified architecture.

  8. Multi-Scale Texturing of Metallic Surfaces for High Performance Military Systems

    Science.gov (United States)

    2015-08-17

    reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of...Larger scan step sizes facilitated quick collection of statistically significant data for studying crystallographic textures. Beam diameter was set at...s. The velocity of impact was measured to be approximately 10 m/s by recording the mass flow rate. Numerical simulation was performed using ABAQUS

  9. TOPICAL REVIEW - Texturing by cooling a metallic melt in a magnetic field

    Directory of Open Access Journals (Sweden)

    Robert F Tournier and Eric Beaugnon

    2009-01-01

    Full Text Available Processing in a magnetic field leads to the texturing of materials along an easy-magnetization axis when a minimum anisotropy energy exists at the processing temperature; the magnetic field can be applied to a particle assembly embedded into a liquid, or to a solid at a high diffusion temperature close to the melting temperature or between the liquidus and the solidus temperatures in a region of partial melting. It has been shown in many experiments that texturing is easy to achieve in congruent and noncongruent compounds by applying the field above the melting temperature Tm or above the liquidus temperature of alloys. Texturing from a melt is successful when the overheating temperature is just a few degrees above Tm and fails when the processing time above Tm is too long or when the overheating temperature is too high; these observations indicate the presence of unmelted crystals above Tm with a size depending on these two variables that act as growth nuclei. A recent model that predicts the existence of unmelted crystals above the melting temperature is used to calculate their radius in a bismuth melt.

  10. Surface defects on the Gd2Zr2O7 oxide films grown on textured NiW technical substrates by chemical solution method

    DEFF Research Database (Denmark)

    Zhao, Y.; Opata, Yuri Aparecido; Wu, W.

    2017-01-01

    Epitaxial growth of oxide thin films has attracted much interest because of their broad applications in various fields. In this study, we investigated the microstructure of textured Gd2Zr2O7 films grown on (001)〈100〉 orientated NiW alloy substrates by a chemical solution deposition (CSD) method...... showed that the Gd2Zr2O7 grains present within the regular-shaped regions are polycrystalline, whereas those present in the surrounding are epitaxial. Some polycrystalline regions ranging from several micrometers to several tens of micrometers grew across the NiW grain boundaries underneath...... of chemical reaction path to enhance the stability and homogeneity of the precursors of the CSD route....

  11. Influence of metal substrates on the detection of explosive residues with laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Gottfried, Jennifer L

    2013-02-01

    Laser-induced breakdown spectroscopy is a promising approach for explosive residue detection, but several limitations to its widespread use remain. One issue is that the emission spectra of the residues are dependent on the substrate composition because some of the substrate is usually entrained in the laser-induced plasma and the laser-material interaction can be significantly affected by the substrate type. Here, we have demonstrated that despite the strong spectral variation in cyclotrimethylenetrinitramine (RDX) residues applied to various metal substrates, classification of the RDX residue independent of substrate type is feasible. Several approaches to improving the chemometric models based on partial least squares discriminant analysis (PLS-DA) have been described: classifying the RDX residue spectra together in one class independent of substrate, using selected emission intensities and ratios to increase the true positive rate (TPR) and decrease the false positive rate (FPR), and fusing the results from two PLS-DA models generated using the full broadband spectra and selected intensities and ratios. The combination of these approaches resulted in a TPR of 97.5% and a FPR of 1.0% for RDX classification on metal substrates.

  12. Incorporation of metal nanoparticles into wood substrate and methods

    Science.gov (United States)

    Rector, Kirk D; Lucas, Marcel

    2015-11-04

    Metal nanoparticles were incorporated into wood. Ionic liquids were used to expand the wood cell wall structure for nanoparticle incorporation into the cell wall structure. Nanoparticles of elemental gold or silver were found to be effective surface enhanced Raman spectroscopy (SERS) imaging contrast or sensing agents. Nanoparticles of elemental iron were found to be efficient microwave absorbers and caused localized heating for disrupting the integrity of the lignocellulosic matrix. Controls suggest that the localized heating around the iron nanoparticles reduces losses of cellulose in the form of water, volatiles and CO.sub.2. The ionic liquid is needed during the incorporation process at room temperature. The use of small amounts of ionic liquid combined with the absence of an ionic liquid purification step and a lower energy and water use are expected to reduce costs in an up-scaled pretreatment process.

  13. Multi-Component Organic Layers on Metal Substrates.

    Science.gov (United States)

    Goiri, Elizabeth; Borghetti, Patrizia; El-Sayed, Afaf; Ortega, J Enrique; de Oteyza, Dimas G

    2016-02-17

    Increasingly high hopes are being placed on organic semiconductors for a variety of applications. Progress along these lines, however, requires the design and growth of increasingly complex systems with well-defined structural and electronic properties. These issues have been studied and reviewed extensively in single-component layers, but the focus is gradually shifting towards more complex and functional multi-component assemblies such as donor-acceptor networks. These blends show different properties from those of the corresponding single-component layers, and the understanding on how these properties depend on the different supramolecular environment of multi-component assemblies is crucial for the advancement of organic devices. Here, our understanding of two-dimensional multi-component layers on solid substrates is reviewed. Regarding the structure, the driving forces behind the self-assembly of these systems are described. Regarding the electronic properties, recent insights into how these are affected as the molecule's supramolecular environment changes are explained. Key information for the design and controlled growth of complex, functional multicomponent structures by self-assembly is summarized. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Flexible Metal Oxide/Graphene Oxide Hybrid Neuromorphic Devices on Flexible Conducting Graphene Substrates

    OpenAIRE

    Wan, Chang Jin; Wang, Wei; Zhu, Li Qiang; Liu, Yang Hui; Feng, Ping; Liu, Zhao Ping; Shi, Yi; Wan, Qing

    2016-01-01

    Flexible metal oxide/graphene oxide hybrid multi-gate neuron transistors were fabricated on flexible graphene substrates. Dendritic integrations in both spatial and temporal modes were successfully emulated, and spatiotemporal correlated logics were obtained. A proof-of-principle visual system model for emulating lobula giant motion detector neuron was investigated. Our results are of great interest for flexible neuromorphic cognitive systems.

  15. Thin film pc-Si by aluminium induced crystallization on metallic substrate

    Directory of Open Access Journals (Sweden)

    Cayron C.

    2013-04-01

    Full Text Available Thin film polycrystalline silicon (pc-Si on flexible metallic substrates is promising for low cost production of photovoltaic solar cells. One of the attractive methods to produce pc-Si solar cells consists in thickening a large-grained seed layer by epitaxy. In this work, the deposited seed layer is made by aluminium induced crystallization (AIC of an amorphous silicon (a-Si thin film on metallic substrates (Ni/Fe alloy initially coated with a tantalum nitride (TaN conductive diffusion barrier layer. Effect of the thermal budget on the AIC grown pc-Si seed layer was investigated in order to optimize the process (i.e. the quality of the pc-Si thin film. Structural and optical characterizations were carried out using optical microscopy, μ-Raman and Electron Backscatter Diffraction (EBSD. At optimal thermal annealing conditions, the continuous AIC grown pc-Si thin film showed an average grain size around 15 μm. The grains were preferably (001 oriented which is favorable for its epitaxial thickening. This work proves the feasibility of the AIC method to grow large grains pc-Si seed layer on TaN coated metal substrates. These results are, in terms of grains size, the finest obtained by AIC on metallic substrates.

  16. Materials design considerations involved in the fabrication of implantable bionics by metallization of ceramic substrates.

    Science.gov (United States)

    Patel, Sunil; Guenther, Thomas; Dodds, Christopher W D; Kolke, Sergej; Privat, Karen L; Matteucci, Paul B; Suaning, Gregg J

    2013-01-01

    The Pt metallization of co-fired Al2O3/SiO2 substrates containing Pt feedthroughs was shown to be a suitable means to construct implantable bionics. The use of forge welding to join an electrode to such a metallized feedthrough was demonstrated and subsequently evaluated through the use of metallography and electron microscopy. Metallurgical phenomena involved in forge welding relevant to the fabrication of all types of biomedical implants are discussed within this paper. The affect of thermal profiles used in brazing or welding to build implantable devices from metal components is analysed and the case for considered selection of alloys in implant design is put forward.

  17. Relation between morphology and work function of metals deposited on organic substrates

    Science.gov (United States)

    Kampen, T. U.; Das, A.; Park, S.; Hoyer, W.; Zahn, D. R. T.

    2004-07-01

    Ultraviolet photoemission spectroscopy (UPS) is employed to determine the work function of silver and indium films grown on two perylene derivatives, dimethylen-3, 4, 9, 10-perylenetetracarboxyiimide (DiMe-PTCDI) and 3, 4, 9, 10-perylenetetracarboxylic dianhydride (PTCDA). The PTCDA and DiMe-PTCDI substrates were prepared as thick organic layers on sulphur passivated GaAs(0 0 1), where the molecular planes of PTCDA and DiMe-PTCDI are parallel and tilted with respect to the substrate surface, respectively. The crystalline structure of the evaporated metal layers is investigated using X-ray diffraction (XRD) and is found to be strongly dependent on the underlying organic substrate. Correspondingly, work functions are found to be different by more than 200 meV in agreement with the crystalline orientation of the metal films.

  18. Thermo-mechanically induced texture evolution and micro-structural change of aluminum metallization

    DEFF Research Database (Denmark)

    Brincker, Mads; Walter, Thomas; Kristensen, Peter Kjær

    2018-01-01

    During operation of high power electronic chips the topside metallization is subjected to cyclic compressive and tensile stresses leading to unwanted thermo-mechanical fatigue of the metallization layer. The stress is caused by the difference in the thermal expansion coefficients of the metalliza...

  19. Usefulness of NIR spectroscopy for the estimation of the mineral composition and texture of soils and heavy metal uptake

    Science.gov (United States)

    Soriano-Disla, J. M.; Gómez, I.; Jordán, M. M.; Guerrero, C.; Navarro-Pedreño, J.; Meseguer, S.; Sanfeliu, T.

    2009-04-01

    The accumulation of heavy metals in soils from different sources (atmospheric deposition, agricultural practices, urban-industrial activities, etc.) is of a great environmental concern. In this sense, there is a consensus in the literature that the total heavy metals in soil are not a suitable tool for risk assessment regarding heavy metal mobility and bioavailability. Several approaches have been proposed to estimate this bioavailability but controversy exists to define an universal method. The bioavailability is influenced, apart from other properties like pH, organic matter, etc., by the mineral fraction and texture of a soil. However, the determination of these parameters, especially the mineral composition, is laborious, expensive, and time consuming. Thus, the objectives of this work are the estimation of the texture and mineral components of contrasting soils and the heavy metal uptake (Cu, Zn, Pb, Ni, Cr, Cd) by barley after sewage sludge application using NIR spectroscopy. A set of 70 contrasting soils from different parts of Spain were used for the analysis of the texture and mineral composition. The mineralogical characterization of soil samples was carried out by X-ray diffraction (XRD) using whole soil random powder, oriented clay on ceramic plates, and clay random powder. Chung method was used for semi-quantitative interpretation of X-ray diffraction patterns of soils, obtaining the percentage of Calcite (Ca), Quartz (Q), Albite (Ab), Potassium Feldspar (FK), phyllosilicates (PS). For the prediction of heavy metal uptake, the 70 soils were divided in two separate sets of 36 (experiment 1) and 34 (experiment 2) soils. The methodology for both experiments, separated in time, was the same. The soils were amended with the same dose of sewage sludge (15.71 g dry weight kg-1) and placed in pots. In these pots, a bioassay with barley, under greenhouse conditions, was carried out. Eight weeks after sowing, the plants were harvested. Roots were dried in an

  20. Epitaxial growth of CdTe thin film on cube-textured Ni by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gaire, C. [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States); Rao, S. [Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States); Riley, M. [Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States); Chen, L. [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States); Goyal, A. [Oak Ridge National Lab, Oak ridge, TN, 37831-6116 (United States); Lee, S. [US Army ARDEC Benet Labs, Watervliet, NY, 12189-4050 (United States); Bhat, I. [Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States); Lu, T.-M. [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States); Wang, G.-C., E-mail: wangg@rpi.edu [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590 (United States)

    2012-01-01

    Single crystal-like CdTe thin film has been grown by metalorganic chemical vapor deposition on cube-textured Ni(100) substrate. Using X-ray pole figure measurements we observed the epitaxial relationship of {l_brace}111{r_brace}{sub CdTe}//{l_brace}001{r_brace}{sub Ni} with [11{sup Macron }0]{sub CdTe}//[010]{sub Ni} and [112{sup Macron }] {sub CdTe}//[100]{sub Ni}. The 12 diffraction peaks in the (111) pole figure of CdTe film and their relative positions with respect to the four peak positions in the (111) pole figure of Ni substrate are consistent with four equivalent orientational domains of CdTe with three to four superlattice match of about 1.6% in the [11{sup Macron }0] direction of CdTe and the [010] direction of Ni. The electron backscattered diffraction images show that the CdTe domains are 30 Degree-Sign oriented from each other. These high structural quality films may find applications in low cost optoelectronic devices.

  1. Malic enzyme: Tritium isotope effects with alternative dinucleotide substrates and divalent metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Karsten, W.E.; Harris, B.G.; Cook, P.F. (Texas College of Osteopathic Medicine, Fort Worth (United States))

    1992-01-01

    The NAD-malic enzyme from Ascaris suum catalyzes the divalent metal ion dependent oxidative decarboxylation of L-malate to yield pyruvate, carbon dioxide and NADH. Multiple isotope effect studies suggest a stepwise chemical mechanism with hydride transfer from L-malate to NAD occurring first to form oxalacetate, followed by decarboxylation. Utilizing L-malate-2-T, tritium V/K isotope effects have been determined for the hydride transfer step using a variety of alternative dinucleotide substrates and divalent metal ions. Combination of these data with deuterium isotope effects data and previously determined [sup 13]C isotope effects has allowed the calculation of intrinsic isotope effects for the malic enzyme catalyzed reaction. The identity of both the dinucleotide substrate and divalent metal ion has an effect of the size of the intrinsic isotope effect for hydride transfer.

  2. Modification of graphene chemistry for metal nanoparticle growth: the effect of substrate selection

    Science.gov (United States)

    Zaniewski, Anna; Nemanich, Robert

    2014-03-01

    Graphene and metal nanoparticle composites are a promising class of materials with unique electronic, optical, and chemical properties. In this work, graphene is used as a reducing surface to grow metal nanoparticles out of solution-based metal precursors. The nanoparticle formation is found to strongly depend upon the graphene substrate selection. The studied substrates include silicon oxide, silicon, lithium niobate, and copper. Our results indicate that the chemical properties of graphene depend upon this selection. For example, for the same reaction times and concentration, the reduction of gold chloride to gold nanoparticles on graphene/lithium niobate results in 3% nanoparticle coverage compared to 20% coverage on graphene/silicon and 60% on graphene/copper. This work is supported through the National Science Foundation under Grant # DMR-1206935 .

  3. The Influence of Ceramic and Metallic Substrates on the Oxidation Behavior of Gold ABA

    Energy Technology Data Exchange (ETDEWEB)

    Weil, K. Scott; Rice, Joseph P.

    2004-12-31

    Two commercial ceramic-to-metal braze alloys, Nioro ABA and Gold ABA, were exposure tested in high-temperature air to evaluate their oxidation behavior, microstructural stability, and materials compatibility for potential application in sealing the ceramic and metal components of a solid-state oxygen separation device. Oxidation studies were conducted on the as-received braze alloy foils, on wetting samples prepared using yttria-stabilized zirconia (YSZ) and stainless steel substrates, and on brazed YSZ/stainless steel joints. It was found that the introduction of the YSZ and/or the stainless steel can significantly modify the inherent oxidation characteristics of these brazes due to accelerated oxygen transport along the braze/ceramic interface and/or diffusion of oxidizable species from the metal substrate into the braze during joining and subsequent segregation and oxidation of these species at the braze/ceramic interface.

  4. Malic enzyme: Tritium isotope effects with alternative dinucleotide substrates and divalent metal ions

    International Nuclear Information System (INIS)

    Karsten, W.E.; Harris, B.G.; Cook, P.F.

    1992-01-01

    The NAD-malic enzyme from Ascaris suum catalyzes the divalent metal ion dependent oxidative decarboxylation of L-malate to yield pyruvate, carbon dioxide and NADH. Multiple isotope effect studies suggest a stepwise chemical mechanism with hydride transfer from L-malate to NAD occurring first to form oxalacetate, followed by decarboxylation. Utilizing L-malate-2-T, tritium V/K isotope effects have been determined for the hydride transfer step using a variety of alternative dinucleotide substrates and divalent metal ions. Combination of these data with deuterium isotope effects data and previously determined 13 C isotope effects has allowed the calculation of intrinsic isotope effects for the malic enzyme catalyzed reaction. The identity of both the dinucleotide substrate and divalent metal ion has an effect of the size of the intrinsic isotope effect for hydride transfer

  5. Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates

    Directory of Open Access Journals (Sweden)

    Leticia Esteban-Tejeda

    2014-07-01

    Full Text Available The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log.

  6. Texture and neutron diffraction

    International Nuclear Information System (INIS)

    Szpunar, J.

    1976-01-01

    The neutron diffraction method has only recently become a tool for studying the structure of polycrystalline materials. There are some fields such as texture studies where this method offers several advantages over other more common methods. Texture is the main subject of the review. The current status of the theory or deformation and recrystallization texture is discussed briefly. Texture is then described with the aid of the ODF function. Finally, applications of the neutron diffraction method are discussed using several examples of textures measured in metals and in non-metallic materials. Other, less known applications of neutron diffraction are also given, e.g. in stress measurements. The neutron diffraction method is extremely useful for studying the texture of coarse-grained materials. This method provides information on the average texture in a large volume. This enables one to measure texture in the same specimen in which anisotropy of the physical roperties has been measured. Selected examples are provided in which correlations between elastic, plastic and magnetic properties of polycrystalline materials and their texture are pointed out. Texture was measured in all these cases using the neutron diffraction method. (author)

  7. 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

    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...

  8. Investigation the effects of metallic substrate surfaces due to ion-plasma treatment

    International Nuclear Information System (INIS)

    Shulaev, V.M.; Taran, V.S.; Timoshenko, A.I.; Gasilin, V.V.

    2011-01-01

    It has been found correlation between modification effects and duration of ion-plasma cleaning the substrate surface with titanium ions. Experiments were carried out using serial vacuum-arc equipment ''Bulat-6'' at the stationary mode in non-filtered titanium plasma, which contained considerable quantity of evaporated material droplets. The polished cylinder substrates (diameter and height 9,14,20 mm) have been treated. The substrates were manufactured of stainless steel 12X18H10T and non-oxygen copper M00b. The substrates surface roughness after ion-plasma treatment has been investigated with electron microscope JEOL JSM-840 and optic interference non-contact profilograph- profilometer ''Micron-alpha''. According obtained results the surface of copper and stainless steel substrates has been treated to intensive modification, i.e. substrate surface after treatment significantly differs from initial one. During final ion-plasma treatment a number of effects occur: purification from surface oxides is accompanied with metallic surface ''contamination'' by the cathode material macrodroplets, surface micromelting accompanied by roughness increase, the surface layer annealing with noticeable decrease of hardness.

  9. Metal Palladium Dispersed Inside Macroporous Ion-Exchange Resins: Textural Characterization and Accessibility to Gaseou Reactants

    Czech Academy of Sciences Publication Activity Database

    Biffis, A.; Jeřábek, Karel; D'Archivio, A. A.; Galantini, L.; Corain, B.

    2000-01-01

    Roč. 130, - (2000), s. 2327-2332 ISSN 0167-2991. [International Congress on Catalysis /12./. Granada, 09.07.2000-14.07.2000] Institutional research plan: CEZ:AV0Z4072921 Keywords : metal palladium * dispersed * ion-exchange resins Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.513, year: 2000

  10. Mesoscale plastic texture in body-centered cubic metals under uniaxial load

    Czech Academy of Sciences Publication Activity Database

    Gröger, Roman; Vitek, V.; Lookman, T.

    2017-01-01

    Roč. 1, č. 6 (2017), s. 063601 E-ISSN 2475-9953 R&D Projects: GA MŠk(CZ) LQ1601; GA ČR(CZ) GA16-13797S Institutional support: RVO:68081723 Keywords : dislocations * mesoscale * bcc metals Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.)

  11. Transfer-Free Electrical Insulation of Epitaxial Graphene from its Metal Substrate

    DEFF Research Database (Denmark)

    Lizzit, Silvano; Larciprete, Rosanna; Lacovig, Paolo

    2012-01-01

    High-quality, large-area epitaxial graphene can be grown on metal surfaces, but its transport properties cannot be exploited because the electrical conduction is dominated by the substrate. Here we insulate epitaxial graphene on Ru(0001) by a stepwise intercalation of silicon and oxygen......, and the eventual formation of a SiO2 layer between the graphene and the metal. We follow the reaction steps by X-ray photoemission spectroscopy and demonstrate the electrical insulation using a nanoscale multipoint probe technique....

  12. Fully solution-processed organic solar cells on metal foil substrates

    KAUST Repository

    Gaynor, Whitney

    2009-08-19

    We demonstrate fully solution-processed organic photovoltaic cells on metal foil substrates with power conversion efficiencies similar to those obtained in devices on transparent substrates. The cells are based on the regioregular poly- (3-hexylthiophene) and C61 butyric acid methyl ester bulk heterojunction system. The bottom electrode is a silver film whose workfunction is lowered by Cs2CO3 using spin-coating to serve as a cathode. The transparent top anode consists of a conductive polymer in combination with a solution-processed silver nanowire mesh that is laminated onto the devices. Each layer of the device, including the transparent electrode, is fabricated from solution, giving rise to the possibility of completely printed solar cells on low-cost substrates.

  13. Recent Developments of Flexible CdTe Solar Cells on Metallic Substrates: Issues and Prospects

    Directory of Open Access Journals (Sweden)

    M. M. Aliyu

    2012-01-01

    Full Text Available This study investigates the key issues in the fabrication of CdTe solar cells on metallic substrates, their trends, and characteristics as well as effects on solar cell performance. Previous research works are reviewed while the successes, potentials, and problems of such technology are highlighted. Flexible solar cells offer several advantages in terms of production, cost, and application over glass-based types. Of all the metals studied as substrates for CdTe solar cells, molybdenum appears the most favorable candidate, while close spaced sublimation (CSS, electrodeposition (ED, magnetic sputtering (MS, and high vacuum thermal evaporation (HVE have been found to be most common deposition technologies used for CdTe on metal foils. The advantages of these techniques include large grain size (CSS, ease of constituent control (ED, high material incorporation (MS, and low temperature process (MS, HVE, ED. These invert-structured thin film CdTe solar cells, like their superstrate counterparts, suffer from problems of poor ohmic contact at the back electrode. Thus similar strategies are applied to minimize this problem. Despite the challenges faced by flexible structures, efficiencies of up to 13.8% and 7.8% have been achieved in superstrate and substrate cell, respectively. Based on these analyses, new strategies have been proposed for obtaining cheaper, more efficient, and viable flexible CdTe solar cells of the future.

  14. Growth of simplified buffer template on flexible metallic substrates for YBa2Cu3O7-δ coated conductors

    International Nuclear Information System (INIS)

    Xue, Yan; Zhang, Ya-Hui; Zhang, Fei; Zhao, Rui-Peng; Wang, Hui; Xiong, Jie; Tao, Bo-Wan

    2016-01-01

    A much simplified buffer structure, including a three-layer stack of LaMnO 3 /MgO/composite Y 2 O 3 –Al 2 O 3 , was proposed for high performance YBa 2 Cu 3 O 7-δ (YBCO) coated conductors. In this structure, biaxially textured MgO films were prepared on solution deposition planarized amorphous substrate through ion-beam-assisted deposition (IBAD) technology. By the use of in situ reflection high-energy electron diffraction monitor, X-ray diffraction and atomic force microscope, the influence of deposition parameters, such as film deposition rate, ion penetrate energy and ion beam flux, on crystalline orientation, texture, lattice parameter and surface morphology was systematically investigated. Moreover, stopping and range of ion in mater simulation was performed to study the effects of ion bombardment on MgO films. By optimizing IBAD process parameters, the best biaxial texture showed ω-scan of (002) MgO and Φ-scan of (220) MgO yield full width at half maximum values of 2.4° and 3.7°, indicating excellent biaxial texture. Subsequently, LaMnO 3 films were directly deposited on the IBAD-MgO template to improve the lattice mismatch between MgO and YBCO. Finally, YBCO films grown on this simplified buffer template exhibited a critical current density of 2.4 MA/cm 2 at 77 K and self-field, demonstrating the feasibility of this buffer structure. - Highlights: • Simplified buffer structure for YBCO coated conductors. • Growth of biaxially textured MgO films on flexible amorphous substrates. • Studying the influence of film deposition rate, ion energy and ion beam flux on the development of biaxial texture. • Demonstrating highly oriented YBCO films with a critical current density of 2.4 MA/cm 2 at self-field and 77 K.

  15. Substrate temperature control for the formation of metal nanohelices by glancing angle deposition

    International Nuclear Information System (INIS)

    Sumigawa, Takashi; Sakurai, Atsushi; Iwata, Kazuya; Chen, Shaoguang; Kitamura, Takayuki; Tanie, Hisashi

    2015-01-01

    The targets of this study are to develop a device to precisely control the temperature during glancing angle deposition, to make films consisting of low melting temperature metal nanoelements with a controlled shape (helix), and to explore the substrate temperature for controlling the nanoshapes. A vacuum evaporation system capable of both cooling a substrate and measurement of its temperature was used to form thin films consisting of arrays of Cu and Al nanohelices on silicon substrates by maintaining the substrate temperature at T s /T m  < 0.22 (T s is the substrate temperature and T m is the melting temperature of target material). The critical T s /T m to produce Cu and Al nanohelices corresponds to the transitional homologous temperature between zones I and II in the structure zone model for the solid film, where surface diffusion becomes dominant. X-ray diffraction analysis indicated that the Cu and Al nanohelix thin films were composed of coarse oriented grains with diameters of several tens of nanometers

  16. Interface structure and mechanics between graphene and metal substrates: a first-principles study

    International Nuclear Information System (INIS)

    Xu Zhiping; Buehler, Markus J

    2010-01-01

    Graphene is a fascinating material not only for technological applications, but also as a test bed for fundamental insights into condensed matter physics due to its unique two-dimensional structure. One of the most intriguing issues is the understanding of the properties of graphene and various substrate materials. In particular, the interfaces between graphene and metal substrates are of critical importance in applications of graphene in integrated electronics, as thermal materials, and in electromechanical devices. Here we investigate the structure and mechanical interactions at a graphene-metal interface through density functional theory (DFT)-based calculations. We focus on copper (111) and nickel (111) surfaces adhered to a monolayer of graphene, and find that their cohesive energy, strength and electronic structure correlate directly with their atomic geometry. Due to the strong coupling between open d-orbitals, the nickel-graphene interface has a much stronger cohesive energy with graphene than copper. We also find that the interface cohesive energy profile features a well-and-shoulder shape that cannot be captured by simple pair-wise models such as the Lennard-Jones potential. Our results provide a detailed understanding of the interfacial properties of graphene-metal systems, and help to predict the performance of graphene-based nanoelectronics and nanocomposites. The availability of structural and energetic data of graphene-metal interfaces could also be useful for the development of empirical force fields for molecular dynamics simulations.

  17. Influence of chemical pretreatment of hard metal substrates for diamond deposition

    International Nuclear Information System (INIS)

    Buck, V.; Kluwe, H.; Schmiler, B.; Deuerler, F.

    2001-01-01

    Diamond coated cutting tools are of increasing importance in the fields of high speed cutting, dry machining or machining of special materials such as metal-matrix-composites. A well known problem is the poor adhesion of diamond films on hard metals due to the Co- or Ni-binder that catalyzes the formation of graphite. Several methods - such as the application of intermediate layers or mechanical or chemical pretreatment of the hard metal substrate - have been developed to overcome this effect. Usually chemical pretreatment is used in order to reduce the concentration of binder phase on the surface that is to be coated. Surprisingly pretreatment with agents such as Murakami's solution result in improved adhesion and nucleation of diamond films while the concentration of the binder phase on the surface is enhanced. This 'contradiction' can be explained by proving that the surface is converted into a very thin oxide/hydroxide film. (author)

  18. Enhancing the Hydrogen Activation Reactivity of Nonprecious Metal Substrates via Confined Catalysis Underneath Graphene.

    Science.gov (United States)

    Zhou, Yinong; Chen, Wei; Cui, Ping; Zeng, Jiang; Lin, Zhuonan; Kaxiras, Efthimios; Zhang, Zhenyu

    2016-10-12

    In the hydrogen evolution reaction (HER), the reactivity as a function of the hydrogen adsorption energy on different metal substrates follows a well-known volcano curve, peaked at the precious metal Pt. The goal of turning nonprecious metals into efficient catalysts for HER and other important chemical reactions is a fundamental challenge; it is also of technological significance. Here, we present results toward achieving this goal by exploiting the synergistic power of marginal catalysis and confined catalysis. Using density functional theory calculations, we first show that the volcano curve stays qualitatively intact when van der Waals attractions between a hydrogen adatom and different metal (111) surfaces are included. We further show that the hydrogen adsorption energy on the metal surfaces is weakened by 0.12-0.23 eV when hydrogen is confined between graphene and the metal surfaces, with Ni exhibiting the largest change. In particular, we find that the graphene-modified volcano curve peaks around Ni, whose bare surface already possesses moderate (or marginal) reactivity, and the corresponding HER rate of graphene-covered Ni is comparable to that of bare Pt. A hydrogen adatom has high mobility within the confined geometry. These findings demonstrate that graphene-covered Ni is an appealing effective, stable, and economical catalytic platform for HER.

  19. Fracture characterization of inhomogeneous wrinkled metallic films deposited on soft substrates

    Science.gov (United States)

    Kishida, Hiroshi; Ishizaka, Satoshi; Nagakura, Takumi; Suzuki, Hiroaki; Yonezu, Akio

    2017-12-01

    This study investigated the fracture properties of wrinkled metallic films on a polydimethylsiloxane (PDMS) soft substrate. In particular, the crack density of the wrinkled film during tensile deformation was examined. In order to achieve better deformability of metallic thin films, a method to fabricate a wrinkled thin film on a PDMS soft substrate was first established. The copper (Cu) nano-film fabricated in this study possessed a wrinkled geometry, which plays a critical role in determining the extent of large elastic deformation. To create the wrinkled structure, wet-etching with a polymeric sacrificial layer was used. A sacrificial layer was first deposited onto a silicone rubber sheet. During the curing process of the layer, a compressive strain was applied such that the hardened surface layer buckled, and a wrinkled form was obtained. Subsequently, a PDMS solution was used to cover the layer in order to form a wrinkled PDMS substrate. Finally, the Cu film was deposited onto the wrinkled PDMS, such that the wrinkled Cu film on a soft PDMS substrate was fabricated. The use of uni-axial tensile tests resulted in film crack generation at the stress concentration zone in the wrinkled structure of the films. When the tensile loading was increased, the number of cracks increased. It was found that the increase in crack density was strongly related to the inhomogeneous nature of the wrinkled structure. Such a trend in crack density was investigated using FEM (finite element method) computations, such that this study established a simple mechanical model that may be used to predict the increase in crack density during tensile deformation. This model was verified through several experiments using various wrinkle patterns. The proposed mechanical model may be useful to predict the crack density of a wrinkled metallic film subject to tensile loading.

  20. Dropwise condensation on inclined textured surfaces

    CERN Document Server

    Khandekar, Sameer

    2014-01-01

    Dropwise Condensation on Textured Surfaces presents a holistic framework for understanding dropwise condensation through mathematical modeling and meaningful experiments. The book presents a review of the subject required to build up models as well as to design experiments. Emphasis is placed on the effect of physical and chemical texturing and their effect on the bulk transport phenomena. Application of the model to metal vapor condensation is of special interest. The unique behavior of liquid metals, with their low Prandtl number and high surface tension, is also discussed. The model predicts instantaneous drop size distribution for a given level of substrate subcooling and derives local as well as spatio-temporally averaged heat transfer rates and wall shear stress.

  1. Ab initio investigations of magnetic properties of ultrathin transition-metal films on 4d substrates

    International Nuclear Information System (INIS)

    In this thesis, we investigate the magnetic properties of 3d transition-metal monolayers on 4d transition-metal substrates by means of state of the art first-principles quantum theory. In order to reveal the underlying physics of these systems we study trends by performing systematic investigations across the transition-metal series. Case studies are presented for which Rh has been chosen as exemplary 4d substrate. We consider two substrate orientations, a square lattice provided by Rh(001) and a hexagonal lattice provided by Rh(111). We find, all 3d transition-metal (V, Cr, Mn, Fe, Co and Ni) monolayers deposited on the Rh substrate are magnetic and exhibit large local moments which follow Hund's rule with a maximum magnetic moment for Mn of about 3.7 μ B depending on the substrate orientation. The largest induced magnetic moment of about 0.46 μ B is found for Rh atoms adjacent to the Co(001)-film. On Rh(001) we predict a ferromagnetic (FM) ground state for V, Co and Ni, while Cr, Mn and Fe monolayers favor a c(2 x 2) antiferromagnetic (AFM) state, a checkerboard arrangement of up and down magnetic moments. The magnetic anisotropy energies of these ultrathin magnetic films are calculated for the FM and the AFM states. With the exception of V and Cr, the easy axis of the magnetization is predicted to be in the film plane. With the exception of Fe, analogous results are obtained for the 3d-metal monolayers on Rh(111). For Fe on Rh(111) a novel magnetic ground state is predicted, a double-row-wise antiferromagnetic state along the [11 anti 2] direction, a sequence of ferromagnetic double-rows of atoms, whose magnetic moments couple antiferromagnetically from double row to double row. The magnetic structure can be understood as superposition of a left- and right-rotating flat spin spiral. In a second set of case studies the properties of an Fe monolayer deposited on varies hexagonally terminated hcp (0001) and fcc (111) surfaces of 4d-transition metals (Tc, Ru, Rh

  2. Ab initio investigations of magnetic properties of ultrathin transition-metal films on 4d substrates

    Energy Technology Data Exchange (ETDEWEB)

    Al-Zubi, Ali

    2010-12-22

    In this thesis, we investigate the magnetic properties of 3d transition-metal monolayers on 4d transition-metal substrates by means of state of the art first-principles quantum theory. In order to reveal the underlying physics of these systems we study trends by performing systematic investigations across the transition-metal series. Case studies are presented for which Rh has been chosen as exemplary 4d substrate. We consider two substrate orientations, a square lattice provided by Rh(001) and a hexagonal lattice provided by Rh(111). We find, all 3d transition-metal (V, Cr, Mn, Fe, Co and Ni) monolayers deposited on the Rh substrate are magnetic and exhibit large local moments which follow Hund's rule with a maximum magnetic moment for Mn of about 3.7 {mu}{sub B} depending on the substrate orientation. The largest induced magnetic moment of about 0.46 {mu}{sub B} is found for Rh atoms adjacent to the Co(001)-film. On Rh(001) we predict a ferromagnetic (FM) ground state for V, Co and Ni, while Cr, Mn and Fe monolayers favor a c(2 x 2) antiferromagnetic (AFM) state, a checkerboard arrangement of up and down magnetic moments. The magnetic anisotropy energies of these ultrathin magnetic films are calculated for the FM and the AFM states. With the exception of V and Cr, the easy axis of the magnetization is predicted to be in the film plane. With the exception of Fe, analogous results are obtained for the 3d-metal monolayers on Rh(111). For Fe on Rh(111) a novel magnetic ground state is predicted, a double-row-wise antiferromagnetic state along the [11 anti 2] direction, a sequence of ferromagnetic double-rows of atoms, whose magnetic moments couple antiferromagnetically from double row to double row. The magnetic structure can be understood as superposition of a left- and right-rotating flat spin spiral. In a second set of case studies the properties of an Fe monolayer deposited on varies hexagonally terminated hcp (0001) and fcc (111) surfaces of 4d

  3. Selective synthesis of double helices of carbon nanotube bundles grown on treated metallic substrates

    International Nuclear Information System (INIS)

    Cervantes-Sodi, Felipe; Iniguez-Rabago, Agustin; Rosas-Melendez, Samuel; Ballesteros-Villarreal, Monica; Vilatela, Juan J.; Reyes-Gutierrez, Lucio G.; Jimenez-Rodriguez, Jose A.; Palacios, Eduardo; Terrones, Mauricio

    2012-01-01

    Double-helix microstructures consisting of two parallel strands of hundreds of multi-walled carbon nanotubes (MWCNTs) have been synthesized by chemical vapour deposition of ferrocene/toluene vapours on metal substrates. Growth of coiled carbon nanostructures with site selectivity is achieved by varying the duration of thermochemical pretreatment to deposit a layer of SiO x on the metallic substrate. Production of multibranched structures of MWCNTs converging in SiO x microstructure is also reported. In the abstract figure, panel (a) shows a coloured micrograph of a typical double-helix coiled microstructure of MWCNTs grown on SiO x covered steel substrate. Green and blue show each of the two individual strands of MWCNTs. Panel (b) is an amplification of a SiO x microparticle (white) on the tip of the double-stranded coil (green and blue). The microparticle guides the collective growth of hundreds of MWCNTs to form the coiled structure. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Metal Nanoparticles Deposited on Porous Silicon Templates as Novel Substrates for SERS

    Directory of Open Access Journals (Sweden)

    Lara Mikac

    2015-12-01

    Full Text Available In this paper, results on preparation of stable and uniform SERS solid substrates using macroporous silicon (pSi with deposited silver and gold are presented. Macroporous silicon is produced by anodisation of p-type silicon in hydrofluoric acid. The as prepared pSi is then used as a template for Ag and Au depositions. The noble metals were deposited in three different ways: by immersion in silver nitrate solution, by drop-casting silver colloidal solution and by pulsed laser ablation (PLA. Substrates obtained by different deposition processes were evaluated for SERS efficiency using methylene blue (MB and rhodamine 6G (R6G at 514.5, 633 and 785 nm. Using 514.5 nm excitation and R6G the limits of detection (LOD for macroporous Si samples with noble metal nanostructures obtained by immersion of pSi sample in silver nitrate solution and by applying silver colloidal solution to pSi template were 10–9 M and 10–8 M respectively. Using 633 nm laser and MB the most noticeable SERS activity gave pSi samples ablated with 30000 and 45000 laser pulses where the LODs of 10–10 M were obtained. The detection limit of 10–10 M was also reached for 4 mA cm–2-15 min pSi sample, silver ablated with 30000 pulses. Macroporous silicon proved to be a good base for the preparation of SERS substrates.

  5. Selective synthesis of double helices of carbon nanotube bundles grown on treated metallic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes-Sodi, Felipe; Iniguez-Rabago, Agustin; Rosas-Melendez, Samuel; Ballesteros-Villarreal, Monica [Departamento de Fisica y Matematicas, Universidad Iberoamericana, Prolongacion Paseo de la Reforma 880, Lomas de Santa Fe (Mexico); Vilatela, Juan J. [IMDEA Materials Institute, E.T.S. de Ingenieros de Caminos, Madrid (Spain); Reyes-Gutierrez, Lucio G.; Jimenez-Rodriguez, Jose A. [Ingenieria Industrial, Grupo JUMEX, Ecatepec de Morelos, Estado de Mexico (Mexico); Palacios, Eduardo [Lab. de Microscopia Electronica de Ultra Alta Resolucion, Instituto Mexicano del Petroleo, San Bartolo Atepehuacan (Mexico); Terrones, Mauricio [Department of Physics, Department of Materials Science and Engineering and Materials Research Institute, Pennsylvania State University, University Park, PA (United States); Research Center for Exotic Nanocarbons (JST), Shinshu University, Nagano (Japan)

    2012-12-15

    Double-helix microstructures consisting of two parallel strands of hundreds of multi-walled carbon nanotubes (MWCNTs) have been synthesized by chemical vapour deposition of ferrocene/toluene vapours on metal substrates. Growth of coiled carbon nanostructures with site selectivity is achieved by varying the duration of thermochemical pretreatment to deposit a layer of SiO{sub x} on the metallic substrate. Production of multibranched structures of MWCNTs converging in SiO{sub x} microstructure is also reported. In the abstract figure, panel (a) shows a coloured micrograph of a typical double-helix coiled microstructure of MWCNTs grown on SiO{sub x} covered steel substrate. Green and blue show each of the two individual strands of MWCNTs. Panel (b) is an amplification of a SiO{sub x} microparticle (white) on the tip of the double-stranded coil (green and blue). The microparticle guides the collective growth of hundreds of MWCNTs to form the coiled structure. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Role of Cooperative Interactions in the Intercalation of Heteroatoms between Graphene and a Metal Substrate

    Science.gov (United States)

    Du, Shixuan

    Graphene, a two-dimensional crystal of carbon atoms packed in a honeycomb structure, has many promising mechanical, electrical, and optical properties. The intercalation of heteroatoms between graphene and a metal substrate has been studied intensively over the past few years, due to its effect on the graphene properties, and as a method to create vertical heterostructures. Various intercalation processes have been reported with different combinations of heteroatoms and substrates. In this talk, I will present the investigation of the key processes governing the intercalation of heteroatoms between graphene and a substrate by combining atomic-scale characterization with density functional theory (DFT). Si intercalation between graphene and Ru(0001) is chosen as a test bed. We elucidate the role of cooperative interactions between heteroatoms, graphene, and substrate. By combining scanning tunneling microscopy with density functional theory, the intercalation process is confirmed to consist of four key steps, involving creation of defects, migration of heteroatoms, self-repairing of graphene, and growth of an intercalated monolayer. Other combinations of heteroatoms (such as Ni, Pd and Pt) and substrates (such as Ir(111) and SiC(0001)) are also investigated to support the generality of our study. Both theory and experiments indicate that this mechanism applies also to other combinations of heteroatoms and substrates. (G. Li et al., J. Am. Chem. Soc. 137 (2015) 7099. In collaboration with G. Li, H.T. Zhou, L.D. Pan, Y. Zhang, L. Huang, W.Y. Xu, and H.J. Gao in CAS, Min Ouyang in MU, and A.C. Ferrari in U. Cambridge.)

  7. Protein-associated water and secondary structure effect removal of blood proteins from metallic substrates.

    Science.gov (United States)

    Anand, Gaurav; Zhang, Fuming; Linhardt, Robert J; Belfort, Georges

    2011-03-01

    Removing adsorbed protein from metals has significant health and industrial consequences. There are numerous protein-adsorption studies using model self-assembled monolayers or polymeric substrates but hardly any high-resolution measurements of adsorption and removal of proteins on industrially relevant transition metals. Surgeons and ship owners desire clean metal surfaces to reduce transmission of disease via surgical instruments and minimize surface fouling (to reduce friction and corrosion), respectively. A major finding of this work is that, besides hydrophobic interaction adhesion energy, water content in an adsorbed protein layer and secondary structure of proteins determined the access and hence ability to remove adsorbed proteins from metal surfaces with a strong alkaline-surfactant solution (NaOH and 5 mg/mL SDS in PBS at pH 11). This is demonstrated with three blood proteins (bovine serum albumin, immunoglobulin, and fibrinogen) and four transition metal substrates and stainless steel (platinum (Pt), gold (Au), tungsten (W), titanium (Ti), and 316 grade stainless steel (SS)). All the metallic substrates were checked for chemical contaminations like carbon and sulfur and were characterized using X-ray photoelectron spectroscopy (XPS). While Pt and Au surfaces were oxide-free (fairly inert elements), W, Ti, and SS substrates were associated with native oxide. Difference measurements between a quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance spectroscopy (SPR) provided a measure of the water content in the protein-adsorbed layers. Hydrophobic adhesion forces, obtained with atomic force microscopy, between the proteins and the metals correlated with the amount of the adsorbed protein-water complex. Thus, the amount of protein adsorbed decreased with Pt, Au, W, Ti and SS, in this order. Neither sessile contact angle nor surface roughness of the metal substrates was useful as predictors here. All three globular proteins

  8. Structural and textural characterization of LiFePO{sub 4} thin films prepared by pulsed laser deposition on Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    Legrand, C.; Dupont, L. [Laboratoire de Reactivite et Chimie des Solides, UMR CNRS 6007, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens Cedex (France); Tang, K.; Li, H.; Huang, X.J. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Baudrin, E., E-mail: emmanuel.baudrin@u-picardie.f [Laboratoire de Reactivite et Chimie des Solides, UMR CNRS 6007, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens Cedex (France)

    2010-07-30

    LiFePO{sub 4} thin films were grown on silicon (100) substrates by pulsed laser deposition using Traditional Geometry (TG) and Off-Axis Geometry (OAG) deposition chambers. We examined and compared the structure and composition of the so formed thin films. The nails observed on the OAG-film present an amorphous 'body' and a crystallized 'head'. The Fe/P ratio determined using energy dispersive spectrometry combined with high angle annular dark field images reveals a metallic iron heart surrounded by LiFePO{sub 4} shell. On the other hand, the protuberances on TG-film are pure iron. The focused ion beam prepared cross-section of the film suggests the presence of iron particles and iron dendritic like filaments inside the LiFePO{sub 4} layer.

  9. Stabilization of ultrathin (hydroxy)oxide films on transition metal substrates for electrochemical energy conversion

    Science.gov (United States)

    Zeng, Zhenhua; Chang, Kee-Chul; Kubal, Joseph; Markovic, Nenad M.; Greeley, Jeffrey

    2017-06-01

    Design of cost-effective electrocatalysts with enhanced stability and activity is of paramount importance for the next generation of energy conversion systems, including fuel cells and electrolysers. However, electrocatalytic materials generally improve one of these properties at the expense of the other. Here, using density functional theory calculations and electrochemical surface science measurements, we explore atomic-level features of ultrathin (hydroxy)oxide films on transition metal substrates and demonstrate that these films exhibit both excellent stability and activity for electrocatalytic applications. The films adopt structures with stabilities that significantly exceed bulk Pourbaix limits, including stoichiometries not found in bulk and properties that are tunable by controlling voltage, film composition, and substrate identity. Using nickel (hydroxy)oxide/Pt(111) as an example, we further show how the films enhance activity for hydrogen evolution through a bifunctional effect. The results suggest design principles for this class of electrocatalysts with simultaneously enhanced stability and activity for energy conversion.

  10. Regal electrochemistry: British 5 pence coins provide useful metallic macroelectrode substrates.

    Science.gov (United States)

    Tan, Fang; Smith, Jamie P; Kampouris, Dimitrios K; Kamieniak, Joanna; Banks, Craig E

    2015-10-07

    The utilisation of British Currency (GBP) as an electrode substrate is demonstrated for the first time. Termed Regal electrochemistry, a 5 pence (5p) coin (GBP) is electrically wired using a bespoke electrochemical cell and is electrochemically characterised using the outer-sphere redox probe hexaammineruthenium(III) chloride. The electroanalytical utility of the 5p coin electrode is demonstrated towards the novel, proof-of-concept sensing of lead(II) ions using square-wave voltammetry in model buffer solutions over the linear range 5-2000 nM exhibiting a limit of detection (3σ) of 1.97 nM. Interestingly, the actual cost of the electrode is 2.5 pence (GBP) since both sides of the coins can be utilised and provide a cheap yet reproducible and disposable metallic electrode substrate that is electrochemically useful.

  11. Use of an arc plasma rotating in a magnetic field for metal coating glass substrates

    International Nuclear Information System (INIS)

    Vukanovic, V.; Butler, S.; Kapur, S.; Krakower, E.; Allston, T.; Belfield, K.; Gibson, G.

    1983-01-01

    First results are reported about deposition of metals on glass substrate using a low current arc plasma source at atmospheric pressure. The arc source consists of a graphite cathode rod placed on the axis of a graphite anode cylinder aligned in a magnetic field. The carrier gas is argon. The deposition material, zinc or gold, is evaporated from a reservoir in the cathode. Depositions on flat substrates positioned on the periphery of the rotating plasma within the anode tube and in a jet outside the anode have been investigated. The investigations are planned to lead towards laser fusion target pusher layer fabrication. This fabrication would be facilitated by a high pressure deposition process where target levitation is readily performed

  12. Development of Ceramic Coating on Metal Substrate using Industrial Waste and Ore Minerals

    Science.gov (United States)

    Bhuyan, S. K.; Thiyagarajan, T. K.; Mishra, S. C.

    2017-02-01

    The technological advancement in modern era has a boon for enlightening human life; but also is a bane to produce a huge amount of (industrial) wastes, which is of great concern for utilization and not to create environmental threats viz. polution etc. In the present piece of research work, attempts have been made to utilize fly ash (wastes of thermal power plants) and along with alumina bearing ore i.e. bauxite, for developing plasma spray ceramic coatings on metals. Fly ash and with 10 and 20% bauxite addition is used to deposit plasma spray coatings on a metal substrate. The surface morphology of the coatings deposited at different power levels of plasma spraying investigated through SEM and EDS analysis. The coating thickness is measured. The porosity levels of the coatings are evaluated. The coating hardness isalso measured. This piece of research work will be beneficial for future development and use of industrial waste and ore minerals for high-valued applications.

  13. Symmetric textures

    International Nuclear Information System (INIS)

    Ramond, P.

    1993-01-01

    The Wolfenstein parametrization is extended to the quark masses in the deep ultraviolet, and an algorithm to derive symmetric textures which are compatible with existing data is developed. It is found that there are only five such textures

  14. Texture studies using neutron diffraction

    International Nuclear Information System (INIS)

    Szpunar, J.A.

    1984-01-01

    Various aspects of the application of neutron scattering methods to texture studies are reviewed. The neutron method is compared with other methods of texture measurement and techniques of neutron diffraction registration of texture are discussed. Examples are presented of the use of neutron scattering for texture examination in materials having various grain sizes and degrees of structural inhomogeneity. It is also demonstrated that the information about texture can be used in the discussion of the deformation and recrystallization processes in metals. Neutron diffraction results are shown to be helpful in the examination of the influence of texture on the anisotropy of physical properties in materials. The possibility of neutron diffraction measurements of magnetic texture is reported. Finally the accuracy of texture measurements using the neutron method is discussed. (author)

  15. Phosphate chemical conversion coatings on metallic substrates for biomedical application: a review.

    Science.gov (United States)

    Liu, Bing; Zhang, Xian; Xiao, Gui-yong; Lu, Yu-peng

    2015-02-01

    Phosphate chemical conversion (PCC) technology has been investigated for improving the surface performance of metallic implants in the biomedical field over the last decade. The metallic materials, such as magnesium and its alloys, titanium, pure iron and stainless steel are widely used as orthopedic devices for immobilization of bone fractures in clinic. They were previously studied as metal substrates for PCC coating aiming to modify their biocompatibility and osteoconductivity. Zinc, calcium and zinc-calcium PCC coatings are frequently utilized considering their nature and the end-use. Although PCC coating has been confirmed to potentially improve the bio-performance of metallic implants in vitro and in vivo by many researchers, there are no unified standards or regulations to give quantitative appraisal of its quality and property. As such, an overview of several main phosphate phases together with their properties and behaviors in vitro and in vivo was conducted. The mechanism of phosphating was also briefly discussed. Critical qualities of PCC coating used for biomedical application including corrosion resistance, wettability and bonding strength were analyzed separately. Biological response including in vitro cell investigations and in vivo tissue response were discussed in terms of the cytocompatibility and bioactivity of PCC coating. Further investigations are proposed to develop appropriate performance evaluation measurements by combining conventional technologies and biomedical procedures. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Proximity Band Structure and Spin Textures on Both Sides of Topological-Insulator/Ferromagnetic-Metal Interface and Their Charge Transport Probes.

    Science.gov (United States)

    Marmolejo-Tejada, Juan Manuel; Dolui, Kapildeb; Lazić, Predrag; Chang, Po-Hao; Smidstrup, Søren; Stradi, Daniele; Stokbro, Kurt; Nikolić, Branislav K

    2017-09-13

    The control of recently observed spintronic effects in topological-insulator/ferromagnetic-metal (TI/FM) heterostructures is thwarted by the lack of understanding of band structure and spin textures around their interfaces. Here we combine density functional theory with Green's function techniques to obtain the spectral function at any plane passing through atoms of Bi 2 Se 3 and Co or Cu layers comprising the interface. Instead of naively assumed Dirac cone gapped by the proximity exchange field spectral function, we find that the Rashba ferromagnetic model describes the spectral function on the surface of Bi 2 Se 3 in contact with Co near the Fermi level E F 0 , where circular and snowflake-like constant energy contours coexist around which spin locks to momentum. The remnant of the Dirac cone is hybridized with evanescent wave functions from metallic layers and pushed, due to charge transfer from Co or Cu layers, a few tenths of an electron-volt below E F 0 for both Bi 2 Se 3 /Co and Bi 2 Se 3 /Cu interfaces while hosting distorted helical spin texture wounding around a single circle. These features explain recent observation of sensitivity of spin-to-charge conversion signal at TI/Cu interface to tuning of E F 0 . Crucially for spin-orbit torque in TI/FM heterostructures, few monolayers of Co adjacent to Bi 2 Se 3 host spectral functions very different from the bulk metal, as well as in-plane spin textures (despite Co magnetization being out-of-plane) due to proximity spin-orbit coupling in Co induced by Bi 2 Se 3 . We predict that out-of-plane tunneling anisotropic magnetoresistance in Cu/Bi 2 Se 3 /Co vertical heterostructure can serve as a sensitive probe of the type of spin texture residing at E F 0 .

  17. Patterning of metallic electrodes on flexible substrates for organic thin-film transistors using a laser thermal printing method

    International Nuclear Information System (INIS)

    Chen, Kun-Tso; Lin, Yu-Hsuan; Ho, Jeng-Rong; Chen, Chih-Kant; Liu, Sung-Ho; Liao, Jin-Long; Cheng, Hua-Chi

    2011-01-01

    We report on a laser thermal printing method for transferring patterned metallic thin films on flexible plastic substrates using a pulsed CO 2 laser. Aluminium and silver line patterns, with micrometre scale resolution on poly(ethylene terephthalate) substrates, are shown. The printed electrodes demonstrate good conductivity and fulfil the properties for bottom-contact organic thin-film transistors. In addition to providing the energy for transferring the film, the absorption of laser light results in a rise in the temperature of the film and the substrate. This also further anneals the film and softens the plastic substrate. Consequently, it is possible to obtain a film with better surface morphology and with its film thickness implanted in part into the plastic surface. This implantation reveals excellent characteristics in adhesion and flexure resistance. Being feasible to various substrates and executable at ambient temperatures renders this approach a potential alternative for patterning metallic electrodes.

  18. Metallization and biopatterning on ultra-flexible substrates via dextran sacrificial layers.

    Science.gov (United States)

    Tseng, Peter; Pushkarsky, Ivan; Di Carlo, Dino

    2014-01-01

    Micro-patterning tools adopted from the semiconductor industry have mostly been optimized to pattern features onto rigid silicon and glass substrates, however, recently the need to pattern on soft substrates has been identified in simulating cellular environments or developing flexible biosensors. We present a simple method of introducing a variety of patterned materials and structures into ultra-flexible polydimethylsiloxane (PDMS) layers (elastic moduli down to 3 kPa) utilizing water-soluble dextran sacrificial thin films. Dextran films provided a stable template for photolithography, metal deposition, particle adsorption, and protein stamping. These materials and structures (including dextran itself) were then readily transferrable to an elastomer surface following PDMS (10 to 70∶1 base to crosslinker ratios) curing over the patterned dextran layer and after sacrificial etch of the dextran in water. We demonstrate that this simple and straightforward approach can controllably manipulate surface wetting and protein adsorption characteristics of PDMS, covalently link protein patterns for stable cell patterning, generate composite structures of epoxy or particles for study of cell mechanical response, and stably integrate certain metals with use of vinyl molecular adhesives. This method is compatible over the complete moduli range of PDMS, and potentially generalizable over a host of additional micro- and nano-structures and materials.

  19. Chlorobenzene, chloroform, and carbon tetrachloride adsorption on undoped and metal-doped sol-gel substrates (SiO2, Ag/SiO2, Cu/SiO2 and Fe/SiO2)

    International Nuclear Information System (INIS)

    Hernandez, M.A.; Gonzalez, A.I.; Corona, L.; Hernandez, F.; Rojas, F.; Asomoza, M.; Solis, S.; Portillo, R.; Salgado, M.A.

    2009-01-01

    Adsorption isotherms of chlorobenzene, chloroform and carbon tetrachloride vapors on undoped SiO 2 , and metal-doped Ag/SiO 2 , Cu/SiO 2 and Fe/SiO 2 substrates were measured in the temperature range of 398-593 K. These substrates were prepared from a typical sol-gel technique in the presence of metal dopants that rendered an assortment of microporous-mesoporous solids. The relevant characteristic of these materials was the different porosities and micropore to mesopore volume ratios that were displayed; this was due to the effect that the cationic metal valence exerts on the size of the sol-gel globules that compose the porous solid. The texture of these SiO 2 materials was analyzed by X-ray diffraction (XRD), FTIR, and diverse adsorption methods. The pore-size distributions of the adsorbents confirmed the existence of mesopores and supermicropores, while ultramicropores were absent. The Freundlich adsorption model approximately fitted the chlorinated compounds adsorption data on the silica substrates by reason of a heterogeneous energy distribution of adsorption sites. The intensity of the interaction between these organic vapors and the surface of the SiO 2 samples was analyzed through evaluation of the isosteric heat of adsorption and standard adsorption energy; from these last results it was evident that the presence of metal species within the silica structure greatly affected the values of both the amounts adsorbed as well as of the isosteric heats of adsorption

  20. Adherence of diamond films on refractory metal substrates for thermionic applications

    International Nuclear Information System (INIS)

    Tsao, B.H.; Ramalingam, M.L.; Adams, S.F.; Cloyd, J.S.

    1991-01-01

    Diamond films are currently being considered as electrical insulation material for application in the thermionic fuel element of a power producing nuclear reactor system. The function of the diamond insulator in this application is to electrically isolate the collector of each cell in the TFE from the coolant and outer sheath. Deposition of diamond films on plane surfaces of Si/SiO 2 have already been demonstrated to be quite effective. However, the diamond films on refractory metal surfaces tend to spall off in the process of deposition revealing an inefficient adherence characteristic between the film and the substrate. This paper is geared towards explaining this deficiency by way of selected experimentation and the use of analytical tools to predict uncertainties such as the mismatch in coefficient of expansion, micrographic study of the interface between the film and the substrate and X-ray diffraction spectra. The investigation of the adherence characteristics of several diamond films on Mo and Nb substrates revealed that there was an allowable stress that resulted in the formation of the critical thickness for the diamond film

  1. Greatly Enhancing Catalytic Activity of Graphene by Doping the Underlying Metal Substrate.

    Science.gov (United States)

    Guo, Na; Xi, Yongjie; Liu, Shuanglong; Zhang, Chun

    2015-07-09

    Graphene-based solid-state catalysis represents a new direction in applications of graphene and has attracted a lot of interests recently. However, the difficulty in fine control and large-scale production of previously proposed graphene catalysts greatly limits their industrial applications. Here we present a novel way to enhance the catalytic activity of graphene, which is highly efficient yet easy to fabricate and control. By first-principles calculations, we show that when the underlying metal substrate is doped with impurities, the catalytic activity of the supported graphene can be drastically enhanced. Graphene supported on a Fe/Ni(111) surface is chosen as a model catalyst, and the chemical reaction of CO oxidation is used to probe the catalytic activity of graphene. When the underlying Fe/Ni(111) substrate is impurity free, the graphene is catalytically inactive. When a Zn atom is doped into the substrate, the catalytic activity of the supported graphene is greatly enhanced, and the reaction barrier of the catalyzed CO oxidation is reduced to less than 0.5 eV. Intriguing reaction mechanism of catalyzed CO oxidation is revealed. These studies suggest a new class of graphene-based catalysts and pave the way for future applications of graphene in solid-state catalysis.

  2. Insights into Substrate Specificity and Metal Activation of Mammalian Tetrahedral Aspartyl Aminopeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuanyuan; Farquhar, Erik R.; Chance, Mark R.; Palczewski, Krzysztof; Kiser, Philip D. (Case Western)

    2012-07-11

    Aminopeptidases are key enzymes involved in the regulation of signaling peptide activity. Here, we present a detailed biochemical and structural analysis of an evolutionary highly conserved aspartyl aminopeptidase called DNPEP. We show that this peptidase can cleave multiple physiologically relevant substrates, including angiotensins, and thus may play a key role in regulating neuron function. Using a combination of x-ray crystallography, x-ray absorption spectroscopy, and single particle electron microscopy analysis, we provide the first detailed structural analysis of DNPEP. We show that this enzyme possesses a binuclear zinc-active site in which one of the zinc ions is readily exchangeable with other divalent cations such as manganese, which strongly stimulates the enzymatic activity of the protein. The plasticity of this metal-binding site suggests a mechanism for regulation of DNPEP activity. We also demonstrate that DNPEP assembles into a functionally relevant tetrahedral complex that restricts access of peptide substrates to the active site. These structural data allow rationalization of the enzyme's preference for short peptide substrates with N-terminal acidic residues. This study provides a structural basis for understanding the physiology and bioinorganic chemistry of DNPEP and other M18 family aminopeptidases.

  3. Metal-enhanced fluorescent detection for protein microarrays based on a silver plasmonic substrate.

    Science.gov (United States)

    Li, Hui; Wang, Min; Qiang, Weibing; Hu, Hongting; Li, Wei; Xu, Danke

    2014-04-07

    This paper presents an ultrasensitive fluorescent detection method through fabricating a silver microarray substrate. Silver nanoparticles (AgNPs) and Ag@Au core-shell nanoparticles with different sizes were first synthesized by a seed-mediated growth method and the metal-enhanced fluorescence of these nanoparticles on different fluorescent dyes was investigated. The results indicated that AgNPs could act as a versatile and effective metal-enhanced fluorescence material for various fluorophores, whereas the enhanced fluorescence from Ag@Au was limited only to certain fluorophores. When the AgNPs were functionalized with aptamers and fluorescent dyes, a good analytical performance for simultaneous detection of human IgE and platelet-derived growth factor-BB (PDGF-BB) could be obtained. AgNPs were not only used as detection tags but also used to fabricate the plasmonic microarray substrate to further enhance the sensitivity of fluorescent detection. As a result, a linear response to PDGF-BB concentration was obtained in the concentration range of 16 pg mL(-1) to 50 ng mL(-1), and the detection limit was 3.2 pg mL(-1). In addition, the AgNP modified plasmonic microarrays showed remarkable recovery and no significant interference from human serum when applied to 2 ng mL(-1) PDGF-BB concentration. The plasmonic microarray substrate demonstrated both high specificity and sensitivity for protein microarray detection and this novel approach has great potential for ultrasensitive detection of protein biomarkers in the bio-medical field.

  4. The effects of Y{sub 2}BaCuO{sub 5} substrate on the melt textured growth of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Choi, C.H.; Zhao, Y.; Sorrell, C.C. [Univ. of New South Wales, Sydney, NSW (Australia). Supercond. Res. Group; La Robina, M. [Australian Nuclear Science and Technol. Organization, Menai (Australia). Advanced Materials Program; Andrikidis, C. [Commonwealth Scientific and Industrial Research Organization, Sydney (Australia). Div. of Applied Physics

    1996-07-16

    The effects of contact area as well as the weight fraction of Y{sub 2}BaCuO{sub 5} (211) substrate on the melt textured growth (MTG) of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (123) crystals are investigated. It is found that the 123 grain size and its orientation have been greatly improved by a well designed 211 substrate with maximized number of contact points. The size of the 123 single domain has been extended up to 2.7 cm with no porosity and cracks by applying 50% of contact area and 35% of absorbed liquid weight into 211 substrate. Magnetization and levitation measurements show that the MTG 123 crystals have a high J{sub c} and a good performance in high magnetic fields. (orig.) 16 refs.

  5. Anticorrosive coating of SixOyCz on metallic substrates applied with the plasma CVD technique

    International Nuclear Information System (INIS)

    Perillo, P; Lasorsa, C; Versaci, R

    2006-01-01

    This work deals with the production of anticorrosive coatings of Si x O y C z on metallic substrates by PECVD (Plasma Enhanced Chemical Vapor Deposition) in a two layer coating, with a gaseous mixture using methyltrimethoxysilane (Z6070) with the contribution of O 2 and methane as reactive gases. The process involves two steps, the first with the substrate thermalized to 500 o C and the second step with the substrate at room temperature. In the first step the process is carried out with the mixture of O 2 and Z6070, in the second step methane is added to the mixture of the plasma forming gases. The coatings were carried out on AISI 410 stainless steel, AISI M2 steel, titanium and AA6061 aluminum substrates. This work presents the preliminary results of the electrochemical evaluation and the mechanical properties of the coating. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS/ESCA ), and scanning electron microscopy were used for this study. Electrochemical techniques were used to study the reaction to the corrosion of the coatings. Potentiodynamic polarization curves were prepared in a solution of 5% H 2 SO 4 and in NaCl 0,1M. The tests were undertaken at room temperature. This process is presented as an alternative to the conventional immersion processes by the sol-gel method, which produces the polymerization of the reagent as a result of the effect of the oxygen from the environment, while the plasma process produces very different chemical reactions in the center of the plasma itself with coatings also different (CW)

  6. Conduction properties of micro-crystals of 2,5-dimethyl- N, N'-dicyanoquinonediimine metal (metal = Ag, Cu) complexes on SiO 2/Si substrates

    Science.gov (United States)

    Yamamoto, Hiroshi M.; Kawasugi, Yoshitaka; Ito, Hiromi; Fukunaga, Takeo; Suzuki, Toshiaki; Tsukagoshi, Kazuhito; Kato, Reizo

    2008-12-01

    Conduction properties of two kinds of DMe-DCNQI complexes deposited on SiO 2/Si substrate are presented. Direct chemical growth of (DMe-DCNQI) 2Ag on the substrate afforded single crystals attached to a gold electrode deposited on the substrate. The system showed bistable switching behavior associated with rectifying property, which seems suitable for resistive random access memory. Speculative mechanism for this behavior is discussed. On the other hand, single crystal of (DMe-DCNQI- d7) 2Cu grown elsewhere was attached to four gold electrodes by carbon paste and fixed on the substrate with epoxy resin. Four-probe measurement of this sample revealed an absence of metal-insulator (M-I) transition which is expected at 80 K for crystal without substrate. This phenomenon can be explained by pseudo-negative pressure effect due to the hard silicon substrate (DMe-DCNQI = 2,5-dimethyl- N, N'-dicyanoquinonediimine).

  7. Waste or substrate for metal hyperaccumulating plants - The potential of phytomining on waste incineration bottom ash.

    Science.gov (United States)

    Rosenkranz, Theresa; Kisser, Johannes; Wenzel, Walter W; Puschenreiter, Markus

    2017-01-01

    Phytomining could represent an innovative low-cost technology for the selective recovery of valuable trace elements from secondary resources. In this context the potential of phytomining from waste incineration bottom ash was tested in a pot experiment. Fresh bottom ash was acidified, leached to reduce salinity and amended with organic material to obtain a suitable substrate for plant growth. Two hyperaccumulator species, Alyssum serpyllifolium subsp. lusitanicum and Sedum plumbizincicola as well as three metal tolerant species, Brassica napus, B. juncea and Nicotiana tabacum were tested for their phytomining potential on the pre-treated and amended bottom ashes from municipal solid waste and hazardous waste incineration. The hyperaccumulators had severe difficulties to establish on the bottom ash and to produce sufficient biomass, likely due to salinity and Cu toxicity. Nevertheless, concentrations of Ni in A. serpyllifolium and Zn in S. plumbizincicola were high, but total metal removal was limited by the low biomass production and was clearly less than on metalliferous soils. The Brassica species proved to be more tolerant to salinity and high Cu concentrations and produced considerably higher biomass, but total metal removal was limited by rather low shoot concentrations. The observed limitations of the phytomining process along with currently low market prices of Ni and Zn suggest that further optimisation of the process is required in order to make phytomining economically feasible on the tested waste incineration bottom ashes. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Nanoscale “Quantum” Islands on Metal Substrates: Microscopy Studies and Electronic Structure Analyses

    Directory of Open Access Journals (Sweden)

    Da-Jiang Liu

    2010-07-01

    Full Text Available Confinement of electrons can occur in metal islands or in continuous films grown heteroepitaxially upon a substrate of a different metal or on a metallic alloy. Associated quantum size effects (QSE can produce a significant height-dependence of the surface free energy for nanoscale thicknesses of up to 10–20 layers. This may suffice to induce height selection during film growth. Scanning STM analysis has revealed remarkable flat-topped or mesa-like island and film morphologies in various systems. We discuss in detail observations of QSE and associated film growth behavior for Pb/Cu(111, Ag/Fe(100, and Cu/fcc-Fe/Cu(100 [A/B or A/B/A], and for Ag/NiAl(110 with brief comments offered for Fe/Cu3Au(001 [A/BC binary alloys]. We also describe these issues for Ag/5-fold i-Al-Pd-Mn and Bi/5-fold i-Al-Cu-Fe [A/BCD ternary icosohedral quasicrystals]. Electronic structure theory analysis, either at the level of simple free electron gas models or more sophisticated Density Functional Theory calculations, can provide insight into the QSE-mediated thermodynamic driving force underlying height selection.

  9. Digital image processing of nanometer-size metal particles on amorphous substrates

    Science.gov (United States)

    Soria, F.; Artal, P.; Bescos, J.; Heinemann, K.

    1989-01-01

    The task of differentiating very small metal aggregates supported on amorphous films from the phase contrast image features inherently stemming from the support is extremely difficult in the nanometer particle size range. Digital image processing was employed to overcome some of the ambiguities in evaluating such micrographs. It was demonstrated that such processing allowed positive particle detection and a limited degree of statistical size analysis even for micrographs where by bare eye examination the distribution between particles and erroneous substrate features would seem highly ambiguous. The smallest size class detected for Pd/C samples peaks at 0.8 nm. This size class was found in various samples prepared under different evaporation conditions and it is concluded that these particles consist of 'a magic number' of 13 atoms and have cubooctahedral or icosahedral crystal structure.

  10. Silver Nanowire Top Electrodes in Flexible Perovskite Solar Cells using Titanium Metal as Substrate.

    Science.gov (United States)

    Lee, Minoh; Ko, Yohan; Min, Byoung Koun; Jun, Yongseok

    2016-01-08

    Flexible perovskite solar cells (FPSCs) have various applications such as wearable electronic textiles and portable devices. In this work, we demonstrate FPSCs on a titanium metal substrate employing solution-processed silver nanowires (Ag NWs) as the top electrode. The Ag NW electrodes were deposited on top of the spiro-MeOTAD hole transport layer by a carefully controlled spray-coating method at moderate temperatures. The power conversion efficiency (PCE) reached 7.45 % under AM 1.5 100 mW cm(-2) illumination. Moreover, the efficiency for titanium-based FPSCs decreased only slightly (by 2.6 % of the initial value) after the devices were bent 100 times. With this and other advances, fully solution-based indium-free flexible photovoltaics, advantageous in terms of price and processing, have the potential to be scaled into commercial production. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. New fabrication method for an ellipsoidal neutron focusing mirror with a metal substrate.

    Science.gov (United States)

    Guo, Jiang; Takeda, Shin; Morita, Shin-ya; Hino, Masahiro; Oda, Tatsuro; Kato, Jun-ichi; Yamagata, Yutaka; Furusaka, Michihiro

    2014-10-06

    We propose an ellipsoidal neutron focusing mirror using a metal substrate made with electroless nickel-phosphorus (NiP) plated material for the first time. Electroless NiP has great advantages for realizing an ellipsoidal neutron mirror because of its amorphous structure, good machinability and relatively large critical angle of total reflection for neutrons. We manufactured the mirror by combining ultrahigh precision cutting and fine polishing to generate high form accuracy and low surface roughness. The form accuracy of the mirror was estimated to be 5.3 μm P-V and 0.8 μm P-V for the minor-axis and major-axis direction respectively, while the surface roughness was reduced to 0.2 nm rms. The effect of form error on focusing spot size was evaluated by using a laser beam and the focusing performance of the mirror was verified by neutron experiments.

  12. Electrodeposition of metallic tungsten coating from binary oxide molten salt on low activation steel substrate

    International Nuclear Information System (INIS)

    Liu, Y.H.; Zhang, Y.C.; Jiang, F.; Fu, B.J.; Sun, N.B.

    2013-01-01

    Tungsten is considered a promising plasma facing armor material for future fusion devices. An electrodeposited metallic tungsten coating from Na 2 WO 4 –WO 3 binary oxide molten salt on low activation steel (LAS) substrate was investigated in this paper. Tungsten coatings were deposited under various pulsed currents conditions at 1173 K in atmosphere. Cathodic current density and pulsed duty cycle were investigated for pulsed current electrolysis. The crystal structure and microstructure of tungsten coatings were characterized by X-ray diffractometry, scanning electron microscopy, and energy X-ray dispersive analysis techniques. The results indicated that pulsed current density and duty cycle significantly influence tungsten nucleation and electro-crystallization phenomena. The average grain size of the coating becomes much larger with increasing cathodic current density, which demonstrates that appropriate high cathodic current density can accelerate the growth of grains on the surface of the substrate. The micro-hardness of tungsten coatings increases with the increasing thickness of coatings; the maximum micro-hardness is 482 HV. The prepared tungsten coatings have a smooth surface, a porosity of less than 1%, and an oxygen content of 0.024 wt%

  13. Structural characteristics and properties of plasma-polymerized films of hexamethyldisiloxane on metal substrates

    Energy Technology Data Exchange (ETDEWEB)

    Zeik, D.B.; Clarson, S.J.; Taylor, C.E.; Boerio, F.J. [Univ. of Cincinnati, OH (United States); van Ooij, W.J.; Sabata, A. [Amco Research & Technology, Middletown, OH (United States)

    1993-12-31

    Films of 500-1000{angstrom} thickness of hexamethyldisiloxane polymerized in an RF discharge were prepared on substrates of cold-rolled steel (CRS) and electrogalvanized steel (EGS). The substrate were pretreated in plasmas of oxygen, argon or mixtures of argon and hydrogen. The objective of this study was to develop new pretreatments of such steels that could possibly obviate the need for oiling, phosphating or chromating, as is routinely done in the automotive and building materials industries. Therefore, important aspects of such films that had to be optimized are corrosion protection, deformability, weldability and paintability. The films were characterized by a multitude of analytical techniques, viz, ellipsometry, reflection-absorption infrared (RAIR), EIS, AES, SEM, XPS and Time-of-Flight SIMS. These techniques allowed a detailed description of the morphology, thickness, structure, elemental depth profiles and compositions of the bulk, the surface and the film-metal interface. Several properties of the films such as adhesion to paint systems and corrosion performance in humidity tests before and after severe mechanical deformation of the films are reported and discussed.

  14. Thermal Stability of Copper-Aluminum Alloy Thin Films for Barrierless Copper Metallization on Silicon Substrate

    Science.gov (United States)

    Wang, C. P.; Dai, T.; Lu, Y.; Shi, Z.; Ruan, J. J.; Guo, Y. H.; Liu, X. J.

    2017-08-01

    Copper thin films with thickness of about 500 nm doped with different aluminum concentrations have been prepared by magnetron sputtering on Si substrate and their crystal structure, microstructure, and electrical resistivity after annealing at various temperatures (200°C to 600°C) for 1 h or at 400°C for different durations (1 h to 11 h) investigated by grazing-incidence x-ray diffraction (GIXRD) analysis, scanning electron microscopy (SEM), and four-point probe (FPP) measurements. Cu-1.8Al alloy thin film exhibited good thermal stability and low electrical resistivity (˜5.0 μΩ cm) after annealing at 500°C for 1 h or 400°C for 7 h. No copper silicide was observed at the Cu-Al/Si interface by GIXRD analysis or SEM for this sample. This result indicates that doping Cu thin film with small amounts of Al can achieve high thermal stability and low electrical resistivity, suggesting that Cu-1.8Al alloy thin film could be used for barrierless Cu metallization on Si substrate.

  15. Synergistic effects of semiconductor substrate and noble metal nano-particles on SERS effect both theoretical and experimental aspects

    Science.gov (United States)

    Yang, Chen; Liang, Pei; Tang, Lisha; Zhou, Yongfeng; Cao, Yanting; Wu, Yanxiong; Zhang, De; Dong, Qianmin; Huang, Jie; He, Peng

    2018-04-01

    As a means of chemical identification and analysis, Surface enhanced Raman spectroscopy (SERS), with the advantages of high sensitivity and selectivity, non-destructive, high repeatability and in situ detection etc., has important significance in the field of composition detection, environmental science, biological medicine etc. Physical model of coupling effect between different semiconductor substrates and noble metal particles were investigated by using 3D-FDTD method. Mechanism and the effects of excitation wavelength, particle spacing and semiconductor substrate types on the SERS effect were discussed. The results showed that the optimal excitation wavelengths of three noble metals of Ag, Au, Cu, were located at 510, 600 and 630 nm, respectively; SERS effect of Ag, Au, Cu increases with the decreasing of the inter distance of particles, while the distance of the NPs reaches the critical value of 3 nm, the strength of SERS effect will be greatly enhanced. For the four different types of substrate of Ge, Si, SiO2 (glass) and Al2O3, the SERS effect of Ag on SiO2 > Ge > Al2O3 > Si. For Au and Cu nanoparticles, the SERS effect of them on oxide substrate is stronger than that on non-oxide substrate. In order to verify FDTD simulations, taking silver nanoparticles as an example, and silver nanoparticles prepared by chemical method were spinning coating on the four different substrates with R6G as probe molecules. The results show that the experimental results are consistent with FDTD theoretical simulations, and the SERS enhancement effect of Ag-SiO2 substrate is best. The results of this study have important theoretical significance to explain the variations of SERS enhancement on different noble metals, which is also an important guide for the preparation of SERS substrates, especially for the microfluidics. The better Raman effect can be realized by choosing proper substrate type, particle spacing and excitation wavelength, result in expanding the depth and width

  16. Influence of substrate metal alloy type on the properties of hydroxyapatite coatings deposited using a novel ambient temperature deposition technique.

    Science.gov (United States)

    Barry, J N; Cowley, A; McNally, P J; Dowling, D P

    2014-03-01

    Hydroxyapatite (HA) coatings are applied widely to enhance the level of osteointegration onto orthopedic implants. Atmospheric plasma spray (APS) is typically used for the deposition of these coatings; however, HA crystalline changes regularly occur during this high-thermal process. This article reports on the evaluation of a novel low-temperature (alloy substrates. This study addresses the suitability of the CoBlast technique for the deposition of HA coatings on a number of alternative metal alloys utilized in the fabrication of orthopedic devices. In addition to titanium grade 5, both cobalt chromium and stainless steel 316 were investigated. In this study, HA coatings were deposited using both the CoBlast and the plasma sprayed techniques, and the resultant HA coating and substrate properties were evaluated and compared. The CoBlast-deposited HA coatings were found to present similar surface morphologies, interfacial properties, and composition irrespective of the substrate alloy type. Coating thickness however displayed some variation with the substrate alloy, ranging from 2.0 to 3.0 μm. This perhaps is associated with the electronegativity of the metal alloys. The APS-treated samples exhibited evidence of both coating, and significantly, substrate phase alterations for two metal alloys; titanium grade 5 and cobalt chrome. Conversely, the CoBlast-processed samples exhibited no phase changes in the substrates after depositions. The APS alterations were attributed to the brief, but high-intensity temperatures experienced during processing. Copyright © 2013 Wiley Periodicals, Inc.

  17. Nitrogen-Doped Graphene on Transition Metal Substrates as Efficient Bifunctional Catalysts for Oxygen Reduction and Oxygen Evolution Reactions.

    Science.gov (United States)

    Zhou, Si; Liu, Nanshu; Wang, Zhiyu; Zhao, Jijun

    2017-07-12

    Composites of transition metal and carbon-based materials are promising bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), and are widely used in rechargeable metal-air batteries. However, the mechanism of their enhanced bicatalytic activities remains elusive. Herein, we construct N-doped graphene supported by Co(111) and Fe(110) substrates as bifunctional catalysts for ORR and OER in alkaline media. First-principles calculations show that these heterostructures possess a large number of active sites for ORR and OER with overpotentials comparable to those of noble metal benchmark catalysts. The catalytic activity is modulated by the coupling strength between graphene and the metal substrates, as well as the charge distribution in the graphitic sheet, which is delicately mediated by N dopants. These theoretical results uncover the key parameters that govern the bicatalytic properties of hybrid materials and help prescribe the principles for designing multifunctional electrocatalysts of high performance.

  18. Synthesis and characterization of Cerium-doped hydroxyapatite/polylactic acid composite coatings on metal substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Qiuhua, E-mail: yuanqiuh@szu.edu.cn; Qin, Caoping; Wu, Jianbo; Xu, Anping; Zhang, Ziqiang; Liao, Junquan; Lin, Songxin; Ren, Xiangzhong; Zhang, Peixin

    2016-10-01

    Ce-doped hydroxyapatite/polylactic acid (HA/PLA) composites serving as implant coatings have rarely been studied by other researchers in recent years. This paper was focused to study the existence of Ce ions in structure, chemical composition and surface morphology of HA and its composite coatings. Ce-doped HA powders were synthesized by chemical precipitation method with different Ce molar fractions (0(pure HA), 0.5 mol%, 1 mol% and 2 mol%). And Ce-doped HA/PLA composite coatings were fabricated for the first time on stainless steel substrates by spin coating technique. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) coupled with energy dispersive X-ray detector (EDX), thermo gravimetric-differential thermal analysis (TG-DTA) and X-ray photoelectron spectroscopy (XPS). The results showed that Ce ions were doped into the crystal lattice of apatite successfully. The (Ce + Ca)/P atomic ratios in the doped HA/PLA samples ranged from 1.614 to 1.673, which were very close to the theoretical value of 1.67 for the stoichiometric HA. The addition of PLA could keep metal substrates from catalyzing the decomposition of HA. TG-DTA analysis indicated that Ce-doped HA powder had high thermal stability, and the SEM micrographs revealed that the surface topography of Ce-doped HA/PLA composite coatings was uniform and dense when the Ce molar fraction was 2 mol%. XPS results indicated that the Ce ions doped in HA showed mixed valences of Ce{sup 3+} and Ce{sup 4+}. - Highlights: • Ce-doped HA composite coatings were synthesized by spin-coating technique for the first time. • Ce ions were demonstrated to dope into HA crystal lattice successfully. • The addition of PLA could keep metal substrates from catalyzing the decomposition of HA. • XPS results showed that Ce ions doped in HA have mixed valences of Ce{sup 3+} and Ce{sup 4+}.

  19. Depth profiling of metal overlayers on organic substrates with cluster SIMS.

    Science.gov (United States)

    Shen, Kan; Mao, Dan; Garrison, Barbara J; Wucher, Andreas; Winograd, Nicholas

    2013-11-05

    Molecular depth profiling of organic thin films by erosion with energetic cluster ion beams is a unique aspect of secondary ion mass spectrometry (SIMS) experiments. Although depth profiles of complex multilayer organic structures can be acquired with little damage accumulation and with depth resolution of gold layer of 1.4 to 3.5 nm deposited either on top of or sandwiched within a cholesterol thin film matrix which is several hundred nanometers thick. For these systems, the results show that by erosion with a 40 keV C60(+) beam, reliable depth profiles can always be acquired as indicated by the presence of a steady state molecular ion signal. During the erosion process, however, gold atoms from the gold overlayer are implanted into the cholesterol matrix beneath it, resulting in a reduced sputter yield, an increase in the amount of cholesterol fragmentation and an increase in the thickness of the cluster ion-induced altered layer. The results also show that the effects of the metal film on the organic substrate are independent of the gold film thickness once the film thickness exceeds 1.4 nm. In general, this model study provides mechanistic insight into the depth profiling of heterogeneous thin film structures and offers a possible path for improving the quality of the depth profiles by employing low energy atomic ion sputtering in the region of the metal layer.

  20. Jet formation in spallation of metal film from substrate under action of femtosecond laser pulse

    International Nuclear Information System (INIS)

    Inogamov, N. A.; Zhakhovskii, V. V.; Khokhlov, V. A.

    2015-01-01

    It is well known that during ablation by an ultrashort laser pulse, the main contribution to ablation of the substance is determined not by evaporation, but by the thermomechanical spallation of the substance. For identical metals and pulse parameters, the type of spallation is determined by film thickness d f . An important gauge is metal heating depth d T at the two-temperature stage, at which electron temperature is higher than ion temperature. We compare cases with d f < d T (thin film) and d f ≫ d T (bulk target). Radius R L of the spot of heating by an optical laser is the next (after d f ) important geometrical parameter. The morphology of film bulging in cases where d f < d T on the substrate (blistering) changes upon a change in radius R L in the range from diffraction limit R L ∼ λ to high values of R L ≫ λ, where λ ∼ 1 μm is the wavelength of optical laser radiation. When d f < d T , R L ∼ λ, and F abs > F m , gold film deposited on the glass target acquires a cupola-shaped blister with a miniature frozen nanojet in the form of a tip on the circular top of the cupola (F abs and F m are the absorbed energy and the melting threshold of the film per unit surface area of the film). A new physical mechanism leading to the formation of the nanojet is proposed

  1. Stable iridium dinuclear heterogeneous catalysts supported on metal-oxide substrate for solar water oxidation.

    Science.gov (United States)

    Zhao, Yanyan; Yang, Ke R; Wang, Zechao; Yan, Xingxu; Cao, Sufeng; Ye, Yifan; Dong, Qi; Zhang, Xizi; Thorne, James E; Jin, Lei; Materna, Kelly L; Trimpalis, Antonios; Bai, Hongye; Fakra, Sirine C; Zhong, Xiaoyan; Wang, Peng; Pan, Xiaoqing; Guo, Jinghua; Flytzani-Stephanopoulos, Maria; Brudvig, Gary W; Batista, Victor S; Wang, Dunwei

    2018-03-05

    Atomically dispersed catalysts refer to substrate-supported heterogeneous catalysts featuring one or a few active metal atoms that are separated from one another. They represent an important class of materials ranging from single-atom catalysts (SACs) and nanoparticles (NPs). While SACs and NPs have been extensively reported, catalysts featuring a few atoms with well-defined structures are poorly studied. The difficulty in synthesizing such structures has been a critical challenge. Here we report a facile photochemical method that produces catalytic centers consisting of two Ir metal cations, bridged by O and stably bound to a support. Direct evidence unambiguously supporting the dinuclear nature of the catalysts anchored on α-Fe 2 O 3 is obtained by aberration-corrected scanning transmission electron microscopy (AC-STEM). Experimental and computational results further reveal that the threefold hollow binding sites on the OH-terminated surface of α-Fe 2 O 3 anchor the catalysts to provide outstanding stability against detachment or aggregation. The resulting catalysts exhibit high activities toward H 2 O photooxidation.

  2. TEXTURAL FRACTOGRAPHY

    Directory of Open Access Journals (Sweden)

    Hynek Lauschmann

    2011-05-01

    Full Text Available The reconstitution of the history of a fatigue process is based on the knowledge of any correspondences between the morphology of the crack surface and the velocity of the crack growth (crack growth rate - CGR. The textural fractography is oriented to mezoscopic SEM magnifications (30 to 500x. Images contain complicated textures without distinct borders. The aim is to find any characteristics of this texture, which correlate with CGR. Pre-processing of images is necessary to obtain a homogeneous texture. Three methods of textural analysis have been developed and realized as computational programs: the method based on the spectral structure of the image, the method based on a Gibbs random field (GRF model, and the method based on the idealization of light objects into a fibre process. In order to extract and analyze the fibre process, special methods - tracing fibres and a database-oriented analysis of a fibre process - have been developed.

  3. Several hundred-fold enhanced fluorescence from single fluorophores assembled on silver nanoparticle-dielectric-metal substrate.

    Science.gov (United States)

    Ray, Krishanu; Badugu, Ramachandram; Szmacinski, Henryk; Lakowicz, Joseph R

    2015-10-18

    We observed over 400-fold enhanced fluorescence from single Cy5 molecules assembled on multilayer silver nanoparticle-dielectric-metal (PDM) substrate. This substantial enhancement is due to the near-field enhanced excitation, emission, and interaction of Cy5 with plasmonic nanostructures. Experimental observation is supported by finite-element method calculations.

  4. Two level undercut-profile substrate-based filamentary coated conductors produced using metal organic chemical vapor deposition

    DEFF Research Database (Denmark)

    Insinga, Andrea R.; Sundaram, Aarthi; Hazelton, Drew W.

    2018-01-01

    of a filamentary CC produced in an industrial setup by SuperPower Inc. using ion beam assisted deposition and metal organic chemical vapor deposition (IBAD-MOCVD) on a 2LUPS substrate realized at the Technical University of Denmark (DTU), whereas previous studies discussed the fabrication using alternating beam...

  5. BaxSr1-xTi1.02O3 metal-insulator-metal capacitors on planarized alumina substrates

    NARCIS (Netherlands)

    Tiggelman, M.P.J.; Reimann, K.; Klee, M.; Mauczok, R.; Keur, W.; Hueting, Raymond Josephus Engelbart

    2010-01-01

    Nanocrystalline barium strontium titanate (BaxSr1−xTi1.02O3) thin films with a barium content of x=0.8, 0.9 and 1 have been fabricated in a metal–insulator–metal configuration on glass-planarized alumina substrates. Cost-effective processing measures have been utilized by using poly-crystalline

  6. Correlation of morphology and barrier properties of thin microwave plasma polymer films on metal substrate

    International Nuclear Information System (INIS)

    Barranco, V.; Carpentier, J.; Grundmeier, G.

    2004-01-01

    The barrier properties of thin model organosilicon plasma polymers layers on iron are characterised by means of electrochemical impedance spectroscopy (EIS). Tailored thin plasma polymers of controlled morphology and chemical composition were deposited from a microwave discharge. By the analysis of the obtained impedance diagrams, the evolution of the water uptake φ, coating resistance and polymer capacitance with immersion time were monitored and the diffusion coefficients of the water through the films were calculated. The impedance data correlated well with the chemical structure and morphology of the plasma polymer films with a thickness of less than 100 nm. The composition of the films were determined by means of infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The morphology of the plasma polymer surface and the interface between the plasma polymer and the metal were characterised using atomic force microscopy (AFM). It could be shown that, at higher pressure, the film roughness increases which is probably due to the adsorption of plasma polymer nanoparticles formed in the plasma bulk and the faster film growth. This leads to voids with a size of a few tens of nanometers at the polymer/metal interface. The film roughness increases from the interface to the outer surface of the film. By lowering the pressure and thereby slowing the deposition rate, the plasma polymers perfectly imitate the substrate topography and lead to an excellent blocking of the metal surface. Moreover, the ratio of siloxane bonds to methyl-silyl groups increases which implies that the crosslink density is higher at lower deposition rate. The EIS data consistently showed higher coating resistance as well as lower interfacial capacitance values and a better stability over time for the film deposited at slower pressure. The diffusion coefficient of water in thin and ultra-thin plasma

  7. Pulsed laser deposition of epitaxial YBa{sub 2}Cu{sub 3}O{sub 7-y}/oxide multilayers onto textured NiFe substrates for coated conductor applications

    Energy Technology Data Exchange (ETDEWEB)

    Tomov, R.I. [Department of Materials Science and IRC in Superconductivity, University of Cambridge, Cambridge (United Kingdom)]. E-mail: rit21@cam.ac.uk; Kursumovic, A.; Kang, D.-J.; Glowacki, B.A.; Evetts, J.E. [Department of Materials Science and IRC in Superconductivity, University of Cambridge, Cambridge (United Kingdom); Majoros, M. [IRC in Superconductivity, University of Cambridge, Cambridge (United Kingdom)

    2002-04-01

    Pulsed laser depositions of double-buffer and triple-buffer YBa{sub 2}Cu{sub 3}O{sub 7-y} (YBCO)/Y{sub 2}O{sub 3}(YSZ)/CeO{sub 2} heterostructures have been performed in situ onto commercially available biaxially textured NiFe 50%/50% tape. The deposition in the forming gas (4% H{sub 2}/Ar) from a CeO{sub 2} target and the deposition in vacuum from a CeO{sub 2}:Pd composite target have been explored as two possible routes for cube-on-cube growth of the first buffer layer. The influence of the critical processing parameters on the texture is investigated and some of the issues involved in the reduction of NiO (111) and the formation of cube-on-cube NiO (200) growth are discussed. X-ray diffraction has been used for texture evaluation of the substrate and subsequent deposited layers. The substrate-buffer interface region has been studied by focused ion beam cross section electron microscopy. Both the buffers and YBCO layers show biaxial alignment with {omega} and {phi} scans having optimum YBCO full width at half maximum (FWHM) values of 4.3 deg. and 8.8 deg., respectively. The morphology has been characterized using atomic force microscopy and scanning electron microscopy. The value of T{sub c} (onset) has been measured at 90 K ({delta}T{sub c}=10 K). The critical current density, J{sub c}, has been measured by transport measurements and magnetic measurements performed in a dc SQUID magnetometer. (author)

  8. Development of CPV solar receiver based on insulated metal substrate (IMS): Comparison with receiver based on the direct bonded copper substrate (DBC) - A reliability study

    Science.gov (United States)

    Mabille, Loïc; Mangeant, Christophe; Baudrit, Mathieu

    2012-10-01

    Most of the CPV solar receivers are based on III-V multijunction cells die-attached to a direct bonded copper (DBC) substrate. An alternative to DBC resides in the insulated metal substrate (IMS). This paper presents the behavior of IMS and DBC receivers when tested under accelerated aging conditions such as described in the IEC 62108. Characterization tools involved in the monitoring of potential degradation are electroluminescence (EL), dark-I (V) (DIV), spectral response (EQE), diode factor measurements (VIM), RX tomography (RX-T), and, of course, illuminated I (V) under various concentration factors. Based on EL, DIV and EQE first results, IMS and DBC age in a similar way. Study is ongoing.

  9. Texture of welded joints of 316L stainless steel, multi-scale orientation analysis of a weld metal deposit

    International Nuclear Information System (INIS)

    Bouche, G.; Bechade, J.L.; Mathon, M.H.; Allais, L.; Gourgues, A.F.; Naze, L.

    2000-01-01

    Weld material of type 316L is widely used in stainless steel X weldments in fast breeder reactors. As it is difficult to cut test specimens from an X weldment, the two-phase microstructure of 316L welds was simulated by manually filling a mould with longitudinally deposited weld beads. The material consists of γ columnar grains which form a matrix where δ-ferrite dendrites can be found. The crystallographic texture of the material was investigated on the basis of a multi-scale approach. Neutron diffraction analysis showed that on a macroscopic scale both phases had predominantly the same fibre texture with some reinforcements, {1 0 0} γ being parallel to {1 0 0} δ . Further analysis on an increasingly fine scale were then carried out by EBSD and by TEM, showing that the ferrite dendrites were nearly parallel to the neighbouring austenite columnar grains

  10. Texture of welded joints of 316L stainless steel, multi-scale orientation analysis of a weld metal deposit

    Science.gov (United States)

    Bouche, G.; Béchade, J. L.; Mathon, M. H.; Allais, L.; Gourgues, A. F.; Nazé, L.

    2000-01-01

    Weld material of type 316L is widely used in stainless steel X weldments in fast breeder reactors. As it is difficult to cut test specimens from an X weldment, the two-phase microstructure of 316L welds was simulated by manually filling a mould with longitudinally deposited weld beads. The material consists of γ columnar grains which form a matrix where δ-ferrite dendrites can be found. The crystallographic texture of the material was investigated on the basis of a multi-scale approach. Neutron diffraction analysis showed that on a macroscopic scale both phases had predominantly the same fibre texture with some reinforcements, {1 0 0} γ being parallel to {1 0 0} δ. Further analysis on an increasingly fine scale were then carried out by EBSD and by TEM, showing that the ferrite dendrites were nearly parallel to the neighbouring austenite columnar grains

  11. Application of ultrasonic guided waves to the characterization of texture in metal sheets of cubic and hexagonal crystallites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan.

    1990-10-08

    Ultrasonic techniques have recently been applied to the texture characterization in polycrystalline aggregates of hexagonal crystals. The basis of this application lies in the relations between the elastic constants {bar C}{sub ij} of the aggregates, which can be inferred from ultrasonic wave velocity measurements, and the orientation distribution coefficients. This communication present such relations for aggregates which possess orthotopic material symmetry and hexagonal crystal symmetry for Voigt, Reuss, and Hill averaging methods in a unified and concise representation.

  12. The effect of substrate orientation on the kinetics and thermodynamics of initial oxide-film growth on metals

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, Friederike

    2007-11-19

    This thesis addresses the effect of the parent metal-substrate orientation on the thermodynamics and kinetics of ultra-thin oxide-film growth on bare metals upon their exposure to oxygen gas at low temperatures (up to 650 K). A model description has been developed to predict the thermodynamically stable microstructure of a thin oxide film grown on its bare metal substrate as function of the oxidation conditions and the substrate orientation. For Mg and Ni, the critical oxide-film thickness is less than 1 oxide monolayer and therefore the initial development of an amorphous oxide phase on these metal substrates is unlikely. Finally, for Cu and densely packed Cr and Fe metal surfaces, oxide overgrowth is predicted to proceed by the direct formation and growth of a crystalline oxide phase. Further, polished Al single-crystals with {l_brace}111{r_brace}, {l_brace}100{r_brace} and {l_brace}110{r_brace} surface orientations were introduced in an ultra-high vacuum system for specimen processing and analysis. After surface cleaning and annealing, the bare Al substrates have been oxidized by exposure to pure oxygen gas. During the oxidation, the oxide-film growth kinetics has been established by real-time in-situ spectroscopic ellipsometry. After the oxidation, the oxide-film microstructures were investigated by angle-resolved X-ray photoelectron spectroscopy and low energy electron diffraction. Finally, high-resolution transmission electron microscopic analysis was applied to study the microstructure and morphology of the grown oxide films on an atomic scale. (orig.)

  13. Crystallographic textures

    Directory of Open Access Journals (Sweden)

    Klosek Vincent

    2017-01-01

    Full Text Available In material science, crystallographic texture is an important microstructural parameter which directly determines the anisotropy degree of most physical properties of a polycrystalline material at the macro scale. Its characterization is thus of fundamental and applied importance, and should ideally be performed prior to any physical property measurement or modeling. Neutron diffraction is a tool of choice for characterizing crystallographic textures: its main advantages over other existing techniques, and especially over the X-ray diffraction techniques, are due to the low neutron absorption by most elements. The obtained information is representative of a large number of grains, leading to a better accuracy of the statistical description of texture.

  14. Jet formation in spallation of metal film from substrate under action of femtosecond laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Inogamov, N. A., E-mail: nailinogamov@googlemail.com [Russian Academy of Sciences, Landau Institute for Theoretical Physics (Russian Federation); Zhakhovskii, V. V. [Dukhov All-Russia Research Institute of Automatics (Russian Federation); Khokhlov, V. A. [Russian Academy of Sciences, Landau Institute for Theoretical Physics (Russian Federation)

    2015-01-15

    It is well known that during ablation by an ultrashort laser pulse, the main contribution to ablation of the substance is determined not by evaporation, but by the thermomechanical spallation of the substance. For identical metals and pulse parameters, the type of spallation is determined by film thickness d{sub f}. An important gauge is metal heating depth d{sub T} at the two-temperature stage, at which electron temperature is higher than ion temperature. We compare cases with d{sub f} < d{sub T} (thin film) and d{sub f} ≫ d{sub T} (bulk target). Radius R{sub L} of the spot of heating by an optical laser is the next (after d{sub f}) important geometrical parameter. The morphology of film bulging in cases where d{sub f} < d{sub T} on the substrate (blistering) changes upon a change in radius R{sub L} in the range from diffraction limit R{sub L} ∼ λ to high values of R{sub L} ≫ λ, where λ ∼ 1 μm is the wavelength of optical laser radiation. When d{sub f} < d{sub T}, R{sub L} ∼ λ, and F{sub abs} > F{sub m}, gold film deposited on the glass target acquires a cupola-shaped blister with a miniature frozen nanojet in the form of a tip on the circular top of the cupola (F{sub abs} and F{sub m} are the absorbed energy and the melting threshold of the film per unit surface area of the film). A new physical mechanism leading to the formation of the nanojet is proposed.

  15. Electro-chemical deposition of nano hydroxyapatite-zinc coating on titanium metal substrate.

    Science.gov (United States)

    El-Wassefy, N A; Reicha, F M; Aref, N S

    2017-08-13

    Titanium is an inert metal that does not induce osteogenesis and has no antibacterial properties; it is proposed that hydroxyapatite coating can enhance its bioactivity, while zinc can contribute to antibacterial properties and improve osseointegration. A nano-sized hydroxyapatite-zinc coating was deposited on commercially pure titanium using an electro-chemical process, in order to increase its surface roughness and enhance adhesion properties. The hydroxyapatite-zinc coating was attained using an electro-chemical deposition in a solution composed of a naturally derived calcium carbonate, di-ammonium hydrogen phosphate, with a pure zinc metal as the anode and titanium as the cathode. The applied voltage was -2.5 for 2 h at a temperature of 85 °C. The resultant coating was characterized for its surface morphology and chemical composition using a scanning electron microscope (SEM), energy dispersive x-ray spectroscope (EDS), and Fourier transform infrared (FT-IR) spectrometer. The coated specimens were also evaluated for their surface roughness and adhesion quality. Hydroxyapatite-zinc coating had shown rosette-shaped, homogenous structure with nano-size distribution, as confirmed by SEM analysis. FT-IR and EDS proved that coatings are composed of hydroxyapatite (HA) and zinc. The surface roughness assessment revealed that the coating procedure had significantly increased average roughness (Ra) than the control, while the adhesive tape test demonstrated a high-quality adhesive coat with no laceration on tape removal. The developed in vitro electro-chemical method can be employed for the deposition of an even thickness of nano HA-Zn adhered coatings on titanium substrate and increases its surface roughness significantly.

  16. Substrate-Based Noble-Metal Nanomaterials: Shape Engineering and Applications

    Science.gov (United States)

    Hajfathalian, Maryam

    Nanostructures have potential for use in state-of-the-art applications such as sensing, imaging, therapeutics, drug delivery, and electronics. The ability to fabricate and engineer these nanoscale materials is essential for the continued development of such devices. Because the morphological features of nanomaterials play a key role in determining chemical and physical properties, there is great interest in developing and improving methods capable of controlling their size, shape, and composition. While noble nanoparticles have opened the door to promising applications in fields such as imaging, cancer targeting, photothermal treatment, drug delivery, catalysis and sensing, the synthetic processes required to form these nanoparticles on surfaces are not well-developed. Herein is a detailed account on efforts for adapting established solution-based seed-mediated synthetic protocols to structure in a substrate-based platform. These syntheses start by (i) defining heteroepitaxially oriented nanostructured seeds at site-specific locations using lithographic or directed-assembly techniques, and then (ii) transforming the seeds using either a solution or vapor phase processing route to activate kinetically- or thermodynamically-driven growth modes, to arrive at nanocrystals with complex and useful geometries. The first series of investigations highlight synthesis-routes based on heterogeneous nucleation, where templates serve as nucleation sites for metal atoms arriving in the vapor phase. In the first research direction, the vapor-phase heterogeneous nucleation of Ag on Au was carried out at high temperatures, where the Ag vapor was sourced from a sublimating foil onto adjacent Au templates. This process transformed both the composition and morphology of the initial Au Wulff-shaped nanocrystals to a homogeneous AuAg nanoprism. In the second case, the vapor-phase heterogeneous nucleation of Cu atoms on Au nanocrystal templates was investigated by placing a Cu foil next

  17. Substrate Lattice-Guided Seed Formation Controls the Orientation of 2D Transition Metal Dichalcogenides

    KAUST Repository

    Aljarb, Areej

    2017-08-07

    Two-dimensional (2D) transition metal dichalcogenide (TMDCs) semiconductors are important for next-generation electronics and optoelectronics. Given the difficulty in growing large single crystals of 2D TMDC materials, understanding the factors affecting the seed formation and orientation becomes an important issue for controlling the growth. Here, we systematically study the growth of molybdenum disulfide (MoS2) monolayer on c-plane sapphire with chemical vapor deposition (CVD) to discover the factors controlling their orientation. We show that the concentration of precursors, i.e., the ratio between sulfur and molybdenum oxide (MoO3), plays a key role in the size and orientation of seeds, subsequently controlling the orientation of MoS2 monolayers. High S/MoO3 ratio is needed in the early stage of growth to form small seeds that can align easily to the substrate lattice structures while the ratio should be decreased to enlarge the size of the monolayer at the next stage of the lateral growth. Moreover, we show that the seeds are actually crystalline MoS2 layers as revealed by high-resolution transmission electron microscopy. There exist two preferred orientations (0° or 60°) registered on sapphire, confirmed by our density functional theory (DFT) simulation. This report offers a facile technique to grow highly aligned 2D TMDCs and contributes to knowledge advancement in growth mechanism.

  18. Study of polymorphism using patterned self-assembled monolayers approach on metal substrates

    Science.gov (United States)

    Quiñones, Rosalynn; Brown, Ryanne T.; Searls, Noah; Richards-Waugh, Lauren

    2018-01-01

    Polymorphism is a molecule's ability to possess altered physical crystalline structures and has become an active interest in pharmaceuticals due to its ability to influence a drug's physical and chemical properties. Crystal stability and solubility are crucial in determining a drug's pharmacokinetics and pharmacodynamics. Changes in these properties due to polymorphisms have contributed to recalls and modifications in industrial production. For this study, the effects of surface interactions with pharmaceuticals were examined through surface modification methodology using organic phosphonic and sulfonic acid self-assembled monolayers (SAMs) developed on a nickel or zinc oxide metal substrate. Drugs analyzed included carbamazepine, cimetidine, tolfenamic acid, and flufenamic acid. All drugs were thermodynamically applied to the reformed surface to aid in recrystallization. It was hypothesized and confirmed that intermolecular bonds, especially hydrogen bonds between the SAMs and pharmaceutical drugs, were the force that assisted in polymorph development. The study was successful in revealing multiple forms for each drug, including their commercial form and at least one additional form using micro FT-IR, Raman spectroscopy, and PXRD. Visual comparisons of crystal polymorphisms were performed with IR microscopy.

  19. Programming Feature Size in the Thermal Wrinkling of Metal Polymer Bilayer by Modulating Substrate Viscoelasticity.

    Science.gov (United States)

    Das, Anuja; Banerji, Aditya; Mukherjee, Rabibrata

    2017-07-12

    We report a novel strategy for creating stress-induced self-organized wrinkles in a metal polymer bilayer with programmable periodicity (λ S ) varying over a wide range, from ∼20 μm down to ∼800 nm by modulating the viscoelasticity of the bottom polymer layer. Substrates with different viscoelasticity are prepared by precuring thin films of a thermo-curable poly dimethylsiloxane (PDMS) elastomer (Sylgard 184) for different durations (t P ) prior to deposition of the top aluminum layer by thermal evaporation. Precuring of the Sylgard 184 film for different durations leads to films with different degrees of viscoelasticity due to variation in the extent of cross-linking of the polymer matrix. The λ S as well as the amplitude (a S ) of the wrinkles progressively decrease with an increase in the extent of elasticity of the film, manifested as an increase in the storage modulus (G'). Based on the variation in the rate of decay of λ S with G', we identify three clearly distinguishable regimes over predominantly viscous, viscoelastic, and elastic bottom layers. While λ S and a S drop with an increase in G' for both the first and the third regimes, it remains nearly independent of G' for the intermediate regime. This is attributed to the difference in the mechanisms of wrinkle formation in the different regimes. We finally show that simultaneous modulation of λ S and a S can be used to engineer surfaces with different wettability as well as anti-reflection properties.

  20. Characterization of PZT thin films on metal substrates; Charakterisierung von PZT-Duennschichten auf Metallsubstraten

    Energy Technology Data Exchange (ETDEWEB)

    Dutschke, A.

    2008-02-02

    Lead zirconate titanate (PbZr{sub x}Ti{sub 1-x}O{sub 3},PZT) is one of the most applied ceramic materials because of its distinctive piezo- and ferroelectric properties. Prepared as thin films on flexible, metallic substrates it can be used for various applications as strain gauges, key switches, vibration dampers, microactuators and ultrasonic transducers. The aim of this work is to analyze the microstructure and the phase-content of PZT-thin films deposited on temperature- und acid-resistant hastelloy-sheets, to correlate the results with the ferroelectric and dielectric properties. It is demonstrated, that the specific variation of the microstructure can be achieved by different thermal treatments and the selective addition of Neodymium as dopant. Nd-doping leads to a shift of the maximum nucleation rate towards reduced temperatures and a decrease in the rate of growth compared to undoped films. The PZT-films are prepared by a sol-gel-process in fourfold multilayers with a composition near the morphotropic phase boundary, where the tetragonal und rhombohedral perovskite-phases coexist. The crystallisation in Nd-doped and undoped films takes place heterogeneously, preferentially at the interfaces and on the surface of the multilayered films as well as on the inner surface of pores within the films. For the first time, the Zr:Ti fluctuation phenomena emerging in sol-gel derived PZT films is related to the microstructure and the local phase content on a nanometer scale. In this connection it is proved, that long-distance Zr:Ti gradients arise preferentially before and during the crystallisation of the pyrochlore phase. During the following crystallisation of the perovskite phase, the crystallites grow across these gradients without modifying them. It is pointed out that the fluctuation in the Zr:Ti ratio has only minor influence on the amount of the tetragonal or rhombohedral distortion of the crystallites after the transition from the para- to the ferroelectric

  1. Textural variations and fragmentation processes in peperite formed between felsic lava flow and wet substrate: An example from the Cretaceous Buan Volcanics, southwest Korea

    Science.gov (United States)

    Gihm, Yong Sik; Kwon, Chang Woo

    2017-02-01

    Multiple exposures of peperite within the Cretaceous Buan Volcanics, southwest Korea, have been examined in order to determine variations in their textural characteristics and to investigate their mode of formation. Along undulating boundaries between rhyolite (lava flow) and deformed host sediment expressed as a series of load and flame structures, exposures commonly contain two distinct types of peperite. Type-1 peperites are composed mostly of rounded juvenile clasts at their base and polyhedral juvenile clasts at their upper levels, interpreted to have formed via a two-stage process. Firstly, abrasion of juvenile clasts occurred after their fragmentation due to shear stress imparted by the overlying and still-moving lava flow, forming rounded juvenile clasts. Subsequent in situ quenching fragmentation of the lava flow produced clasts with platy to polyhedral shapes immediately after emplacement of the lava flow. Type-2 peperites laterally extend into the interior of featureless rhyolite as layers that decrease in thickness with increasing distance away from the flame zone. These layers exhibit horizontal textural variations, ranging from poorly sorted mixtures of ash- to block-sized angular juvenile clasts in the proximal zone, to closely packed polyhedral and tabular juvenile clasts with jigsaw-crack textures in the middle and distal zones. Type-2 peperite are inferred to have formed due to internal steam explosions that resulted from an expansion of heated pore water (leading to an increase in pore fluid pressure) that had been vertically injected into the interior of the rhyolite from the flame zone. The proximal zone, composed mainly of poorly sorted mixtures of juvenile clasts, represents the explosion sites. Juvenile clasts in the middle and distal zones are interpreted to have formed due to three separate processes: the development of fractures in the rhyolite during the internal steam explosions, injection of the host sediment through the fractures, and

  2. Modeling of metal nanocluster growth on patterned substrates and surface pattern formation under ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, Satoshi

    2012-11-01

    This work addresses the metal nanocluster growth process on prepatterned substrates, the development of atomistic simulation method with respect to an acceleration of the atomistic transition states, and the continuum model of the ion-beam inducing semiconductor surface pattern formation mechanism. Experimentally, highly ordered Ag nanocluster structures have been grown on pre-patterned amorphous SiO{sub 2} surfaces by oblique angle physical vapor deposition at room temperature. Despite the small undulation of the rippled surface, the stripe-like Ag nanoclusters are very pronounced, reproducible and well-separated. The first topic is the investigation of this growth process with a continuum theoretical approach to the surface gas condensation as well as an atomistic cluster growth model. The atomistic simulation model is a lattice-based kinetic Monte-Carlo (KMC) method using a combination of a simplified inter-atomic potential and experimental transition barriers taken from the literature. An effective transition event classification method is introduced which allows a boost factor of several thousand compared to a traditional KMC approach, thus allowing experimental time scales to be modeled. The simulation predicts a low sticking probability for the arriving atoms, millisecond order lifetimes for single Ag monomers and {approx}1 nm square surface migration ranges of Ag monomers. The simulations give excellent reproduction of the experimentally observed nanocluster growth patterns. The second topic specifies the acceleration scheme utilized in the metallic cluster growth model. Concerning the atomistic movements, a classical harmonic transition state theory is considered and applied in discrete lattice cells with hierarchical transition levels. The model results in an effective reduction of KMC simulation steps by utilizing a classification scheme of transition levels for thermally activated atomistic diffusion processes. Thermally activated atomistic movements

  3. Direct and contactless electrical control of temperature of paper and textile foldable substrates using electrospun metallic-web transparent electrodes

    Science.gov (United States)

    Busuioc, Cristina; Evanghelidis, Alexandru; Galatanu, Andrei; Enculescu, Ionut

    2016-10-01

    Multiple and complex functionalities are a demand nowadays for almost all materials, including common day-to-day materials such as paper, textiles, wood, etc. In the present report, the surface temperature control of different types of materials, including paper and textiles, was demonstrated by Joule heating of metallic-web transparent electrodes both by direct current and by RF induced eddy currents. Polymeric submicronic fiber webs were prepared by electrospinning, and metal sputtering was subsequently performed to transform them into flexible transparent electrodes. These electrodes were thermally attached to different substrates, including paper, textiles and glass. Using thermochromic inks, we demonstrated a high degree of control of the substrates’ surface temperature by means of the Joule effect. Metallic fiber webs appear to be excellently suited for use as transparent electrodes for controlling the surface temperature of common materials, their highly flexible nature being a major advantage when dealing with rough, bendable substrates. This kind of result could not be achieved on bendable substrates with rough surfaces such as paper or textiles while employing classical transparent electrodes i.e. metal oxides. Moreover, contactless heating with induced currents is a premiere for transparent electrodes and opens up a score of new application fields.

  4. Comparison of two metal-dependent pyruvate aldolases related by convergent evolution: substrate specificity, kinetic mechanism, and substrate channeling.

    Science.gov (United States)

    Wang, Weijun; Baker, Perrin; Seah, Stephen Y K

    2010-05-04

    HpaI and BphI are two pyruvate class II aldolases found in aromatic meta-cleavage degradation pathways that catalyze similar reactions but are not related in sequence. Steady-state kinetic analysis of the aldol addition reactions and product inhibition assays showed that HpaI exhibits a rapid equilibrium random order mechanism while BphI exhibits a compulsory order mechanism, with pyruvate binding first. Both aldolases are able to utilize aldehyde acceptors two to five carbons in length; however, HpaI showed broader specificity and had a preference for aldehydes containing longer linear alkyl chains or C2-OH substitutions. Both enzymes were able to bind 2-keto acids larger than pyruvate, but only HpaI was able to utilize both pyruvate and 2-ketobutanoate as carbonyl donors in the aldol addition reaction. HpaI lacks stereospecific control producing racemic mixtures of 4-hydroxy-2-oxopentanoate (HOPA) from pyruvate and acetaldehyde while BphI synthesizes only (4S)-HOPA. BphI is also able to utilize acetaldehyde produced by the reduction of acetyl-CoA catalyzed by the associated aldehyde dehydrogenase, BphJ. This aldehyde was directly channeled from the dehydrogenase to the aldolase active sites, with an efficiency of 84%. Furthermore, the BphJ reductive deacylation reaction increased 4-fold when BphI was catalyzing the aldol addition reaction. Therefore, the BphI-BphJ enzyme complex exhibits unique bidirectionality in substrate channeling and allosteric activation.

  5. Structural and chemical characterization of terbia thin films grown on hexagonally close packed metal substrates

    Science.gov (United States)

    Cartas, William

    Rare earth oxides (REOs) exhibit favorable catalytic performance for a diverse set of chemical transformations, including both partial and complete oxidation reactions. I will discuss our efforts to develop thin film systems of terbia for model surface science investigations of a REO that is effectively reducible, and which is thus expected to promote complete oxidation chemistry of adsorbed species. The growth of terbia on Cu(111) is shown to produce a complex surface that exhibits multiple phases of the oxide as well as exposed substrate. Growing the film on Pt(111) results in more uniform, single phase, and closed film. We used low energy electron diffraction (LEED) and scanning tunneling microscopy (STM) to characterize the structural properties of terbia thin films grown on Pt(111) in ultrahigh vacuum (UHV) using physical vapor deposition. We find that the REO grows as a high quality Tb2O 3(111) film, and adopts oxygen-deficient fluorite structures wherein the metal cations form a hexagonal lattice in registry with the Pt(111) substrate, while oxygen vacancies are randomly distributed within the film. The Tb 2O3(111) films are thermally stable when heated to 1000 K in UHV. LEED and STM show that a fraction of the Tb2O3 forms hexagonal islands when first deposited, and further depositions typically result in three dimensional growth of the film. The Tb2O3 (111) / Pt(111) system produces a coincidence structure, seen very clearly in LEED images. We have also found that Tb2O3(111) films can be oxidized in UHV by exposure to plasma-generated atomic oxygen beams. The oxidized films have an estimated TbO2 stoichiometry and decompose to Tb2O3 during heating, with O2 desorption starting at about 500 K. Terbia films oxidized at 90 K show a weakly bound state of oxygen that is likely chemisorbed. Temperature programmed reaction spectroscopy (TPRS) studies using methanol show that increased oxygen in the film does not modify the chemical selectivity of the film; however

  6. Development and characterization of a metallic substrat for nanostructured membranes in the separation of gas mixtures; Entwicklung und Charakterisierung eines metallischen Substrats fuer nanostrukturierte Gastrennmembranen

    Energy Technology Data Exchange (ETDEWEB)

    Brands, Katharina

    2010-07-01

    In order to minimize the further increase of CO{sub 2}-content in the atmosphere, efforts are made to separate and store CO{sub 2} from exhaust gases of fossil power plants. Beside well-established separation techniques like chemical scrubber, the application of membrane technology is intensively investigated. One focus of this thesis is the development of metal supported substrates for microporous ceramic gas separation membranes, which are expected to have a higher mechanical stability than ceramic supported substrates. Starting with commercial porous steel substrates, interlayers are applied by wet powder spraying. For the interlayers the materials 1.4404-stainless steel and TiO{sub 2} or 1.4845-stainless steel and yttria stabilized zirconia (8YSZ) are chosen. The interlayers have to be defect-free, as minimal defects can deteriorate the membrane performance. By a subsequent mechanical treatment and an adjustment of the viscosity of the 8YSZ-suspension, the surface quality is considerably increased. At the same time the limits of the wet powder spraying process become obvious, as sporadic agglomerates, which are formed during the spraying process, cannot be totally avoided. The metal supported substrates are characterized regarding to the interaction between steel and ceramic, the roughness of the layers compared to polished ceramic substrates, the mechanical properties and the flow through the substrates. Furthermore microporous ceramic gas separation membranes are deposited on wet powder sprayed and dip coated substrates. The selectivity of these membranes is above Knudsen selectivity. The other focus of the thesis is the exposure of substrates and membranes to real flue gas conditions. Beside microporous ceramic membranes polymer membranes are analysed as a reference, which show a higher state of development compared to microporous ceramic membranes. For this purpose a test bed is built up in the EnBW ''Rheinhafendampfkraftwerk RDK 7&apos

  7. Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy.

    Science.gov (United States)

    Dominiczak, Maguy; Otubo, Larissa; Alamarguy, David; Houzé, Frédéric; Volz, Sebastian; Noël, Sophie; Bai, Jinbo

    2011-04-14

    Using an atomic force microscope (AFM) at a controlled contact force, we report the electrical signal response of multi-walled carbon nanotubes (MWCNTs) disposed on a golden thin film. In this investigation, we highlight first the theoretical calculation of the contact resistance between two types of conductive tips (metal-coated and doped diamond-coated), individual MWCNTs and golden substrate. We also propose a circuit analysis model to schematize the «tip-CNT-substrate» junction by means of a series-parallel resistance network. We estimate the contact resistance R of each contribution of the junction such as Rtip-CNT, RCNT-substrate and Rtip-substrate by using the Sharvin resistance model. Our final objective is thus to deduce the CNT intrinsic radial resistance taking into account the calculated electrical resistance values with the global resistance measured experimentally. An unwished electrochemical phenomenon at the tip apex has also been evidenced by performing measurements at different bias voltages with diamond tips. For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance. This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip. For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism.

  8. Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy

    Directory of Open Access Journals (Sweden)

    Alamarguy David

    2011-01-01

    Full Text Available Abstract Using an atomic force microscope (AFM at a controlled contact force, we report the electrical signal response of multi-walled carbon nanotubes (MWCNTs disposed on a golden thin film. In this investigation, we highlight first the theoretical calculation of the contact resistance between two types of conductive tips (metal-coated and doped diamond-coated, individual MWCNTs and golden substrate. We also propose a circuit analysis model to schematize the «tip-CNT-substrate» junction by means of a series-parallel resistance network. We estimate the contact resistance R of each contribution of the junction such as R tip-CNT, R CNT-substrate and R tip-substrate by using the Sharvin resistance model. Our final objective is thus to deduce the CNT intrinsic radial resistance taking into account the calculated electrical resistance values with the global resistance measured experimentally. An unwished electrochemical phenomenon at the tip apex has also been evidenced by performing measurements at different bias voltages with diamond tips. For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance. This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip. For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism.

  9. The growth of the metallic ZrNx thin films on P-GaN substrate by pulsed laser deposition

    Science.gov (United States)

    Gu, Chengyan; Sui, Zhanpeng; Li, Yuxiong; Chu, Haoyu; Ding, Sunan; Zhao, Yanfei; Jiang, Chunping

    2018-03-01

    Although metal nitride thin films have attractive prospects in plasmonic applications due to its stable properties in harsh environments containing high temperatures, shock, and contaminants, the effect of deposition parameters on the properties of the metallic ZrN grown on III-N semiconductors by pulse laser deposition still lacks of detailed exploration. Here we have successfully prepared metallic ZrNx films on p-GaN substrate by pulsed laser deposition in N2 ambient of various pressures at a fixed substrate temperature (475 °C). It is found that the films exhibit quite smooth surfaces and (111) preferred orientation. The X-ray photoelectron spectroscopy measurements indicate that carbon contamination can be completely removed and oxygen contamination is significantly reduced on the film surfaces after cleaning using Ar+ sputtering. The N/Zr ratio increases from 0.64 to 0.75 when the N2 pressure increases from 0.5 Pa to 3 Pa. The optical reflectivity spectra measured by the UV-vis-NIR spectrophotometer show that the ZrNx is a typical and good metallic-like material and its metallic properties can be tuned with changing the film compositions.

  10. The fabrication and high temperature stability of biaxially textured Ni tape by ion beam structure modification method

    International Nuclear Information System (INIS)

    Wu, K.; Wang, S.S.; Meng, J.; Han, Z.

    2004-01-01

    For the conventional rolling assisted biaxially textured metallic substrate (RABiTS) process, a large degree of cold rolling deformation and a subsequent high temperature annealing procedure are required to obtain adequately biaxially textured Ni tape. Recently, we have reported a newly developed process, named as ion beam structure modification (ISM), for fabricating biaxially textured Ni tape by use of low energy argon ion beam bombardment. In this paper, the biaxial texture of ISM processed Ni tape and its thermal stability at high temperatures are investigated. Results show that Ni tape processed under optimum ISM conditions, the (2 0 0) rocking curve FWHM is less than 5.7 deg. , and the (1 1 1) phi-scan FWHM is less than 7.5 deg. . High temperature annealing does not impair the biaxial-texture already developed in ISM processed Ni foils, although ISMs should not be regarded as a complete equilibrium process

  11. Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mina, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Tecno-Academia ASTIN SENA Reginal Valle (Colombia); Castaño, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, J.C., E-mail: julio.cesar.caicedo@correo.univalle.edu.co [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, H.H. [Biologics Research, Biotechnology Center of Excellence, Janssen R& D, LLC, Pharmaceutical Companies of Johnson & Johnson, Spring House, PA 19477 (United States); National Biotechnology & Pharmaceutical Association, Chicago, IL 60606 (United States); Aguilar, Y. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia)

    2015-06-15

    Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices.

  12. Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

    International Nuclear Information System (INIS)

    Mina, A.; Castaño, A.; Caicedo, J.C.; Caicedo, H.H.; Aguilar, Y.

    2015-01-01

    Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices

  13. Fabrication of friction-reducing texture surface by selective laser melting of ink-printed (SLM-IP) copper (Cu) nanoparticles(NPs)

    Science.gov (United States)

    Wang, Xinjian; Liu, Junyan; Wang, Yang; Fu, Yanan

    2017-02-01

    This paper reports a process of selective laser melting of ink-printed (SLM-IP) copper (Cu) nanoparticles(NPs) for the fabrication of full dense Cu friction-reducing texture on the metallic surface in ambient condition. This technique synthesizes pure Cu by chemical reduction route using an organic solvent during laser melting in the atmosphere environment, and provides a flexible additive manufacture approach to form complex friction-reduction texture on the metallic surface. Microtextures of ring and disc arrays have been fabricated on the stainless steel surface by SLM-IP Cu NPs. The friction coefficient has been measured under the lubricating condition of the oil. Disc texture surface (DTS) has a relatively low friction coefficient compared with ring texture surface (RTS), Cu film surface (Cu-FS) and the untreated substrate. The study suggests a further research on SLM-IP approach for complex microstructure or texture manufacturing, possibly realizing its advantage of flexibility.

  14. Chemically-modified graphene sheets as an active layer for eco-friendly metal electroplating on plastic substrates

    International Nuclear Information System (INIS)

    Oh, Joon-Suk; Hwang, Taeseon; Nam, Gi-Yong; Hong, Jung-Pyo; Bae, Ah-Hyun; Son, Sang-Ik; Lee, Geun-Ho; Sung, Hak kyung; Choi, Hyouk Ryeol; Koo, Ja Choon; Nam, Jae-Do

    2012-01-01

    Eco-friendly nickel (Ni) electroplating was carried out on a plastic substrate using chemically modified graphene sheets as an active and conductive layer to initiate electroplating without using conventional pre-treatment or electroless metal-seeding processes. A graphene oxide (GO) solution was self-assembled on a polyethylene terephthalate (PET) film followed by evaporation to give GO layers (thickness around 6.5 μm) on PET (GO/PET) film. Then, the GO/PET film was chemically and thermally reduced to convert the GO layers to reduced graphene oxide (RGO) layers on the PET substrate. The RGO-coated PET (RGO/PET) film showed the sheet resistance of 100 Ω per square. On RGO/PET film, Ni electroplating was conducted under the constant-current condition and the entire surface of the PET film was completely metalized with Ni without any voids.

  15. Scattering properties of textured TCO substrates in thin-film silicon solar cells; Streuverhalten von texturierten TCO-Substraten in Silizium-Duennschichtsolarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Melanie

    2009-04-27

    In this PhD thesis the scattering properties of textured transparent conducting oxides (TCO) for the application in thin-film silicon solar cells are investigated. The main focus is the correlation between the nanotextured surface and its scattering behaviour. Therefore a ray tracing model based on geometric optics and atomic force microscopy data is developed. Simulation results are compared and discussed with measurements of angle resolved scattering in the far field and experimentally determined scanning near field microscopy data in the near field. Besides, simulation results obtained by applying geometric optics and solutions of the Maxwell equation in the near field are compared and discussed. The scattering properties of TCO-air and TCO-silicon interfaces are considered. (orig.)

  16. A facile metal-free "grafting-from" route from acrylamide-based substrate toward complex macromolecular combs

    KAUST Repository

    Zhao, Junpeng

    2013-01-01

    High-molecular-weight poly(N,N-dimethylacrylamide-co-acrylamide) was used as a model functional substrate to investigate phosphazene base (t-BuP 4)-promoted metal-free anionic graft polymerization utilizing primary amide moieties as initiating sites. The (co)polymerization of epoxides was proven to be effective, leading to macromolecular combs with side chains being single- or double-graft homopolymer, block copolymer and statistical copolymer. © 2013 The Royal Society of Chemistry.

  17. Nanosecond laser texturing of uniformly and non-uniformly wettable micro structured metal surfaces for enhanced boiling heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Zupančič, Matevž, E-mail: matevz.zupancic@fs.uni-lj.si; Može, Matic; Gregorčič, Peter; Golobič, Iztok

    2017-03-31

    Highlights: • Surfaces with periodically changed wettability were produced by a ns marking laser. • Heat transfer was investigated on uniformly and non-uniformly wettable surfaces. • Microporous surfaces with non-uniform wettability enhance boiling heat transfer. • The most bubble nucleations were observed in the vicinity of the microcavities. • Results agree with the predictions of the nucleation criteria. - Abstract: Microstructured uniformly and non-uniformly wettable surfaces were created on 25-μm-thin stainless steel foils by laser texturing using a marking nanosecond Nd:YAG laser (λ = 1064 nm) and utilizing various laser fluences and scan line separations. High-speed photography and high-speed IR thermography were used to investigate nucleate boiling heat transfer on the microstructured surfaces. The most pronounced results were obtained on a surface with non-uniform microstructure and non-uniform wettability. The obtained results show up to a 110% higher heat transfer coefficients and 20–40 times higher nucleation site densities compared to the untextured surface. We show that the number of active nucleation sites is significantly increased in the vicinity of microcavities that appeared in areas with the smallest (10 μm) scan line separation. Furthermore, this confirms the predictions of nucleation criteria and proves that straightforward, cost-effective nanosecond laser texturing allows the production of cavities with diameters of up to a few micrometers and surfaces with non-uniform wettability. Additionally, this opens up important possibilities for a more deterministic control over the complex boiling process.

  18. Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates

    Energy Technology Data Exchange (ETDEWEB)

    Patty, Kira; Campbell, Quinn; Hamilton, Nathan; West, Robert G. [Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Sadeghi, Seyed M., E-mail: seyed.sadeghi@uah.edu [Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Nano and Micro Device Center, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States); Mao, Chuanbin [Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2014-09-21

    We used photoactive substrates consisting of about 1 nm coating of a metal oxide on glass substrates to investigate the impact of the structures of colloidal quantum dots on their photophysical and photochemical properties. We showed during irradiation these substrates can interact uniquely with such quantum dots, inducing distinct forms of photo-induced processes when they have different cores, shells, or ligands. In particular, our results showed that for certain types of core-shell quantum dot structures an ultrathin layer of a metal oxide can reduce suppression of quantum efficiency of the quantum dots happening when they undergo extensive photo-oxidation. This suggests the possibility of shrinking the sizes of quantum dots without significant enhancement of their non-radiative decay rates. We show that such quantum dots are not influenced significantly by Coulomb blockade or photoionization, while those without a shell can undergo a large amount of photo-induced fluorescence enhancement via such blockade when they are in touch with the metal oxide.

  19. The copper spoil heap Knappenberg, Austria, as a model for metal habitats – Vegetation, substrate and contamination

    Energy Technology Data Exchange (ETDEWEB)

    Adlassnig, Wolfram; Weiss, Yasmin S. [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria); Sassmann, Stefan [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria); University of Exeter, College of Life and Environmental Sciences, Biosciences, Stocker Road, Exeter EX4 4QD (United Kingdom); Steinhauser, Georg [Leibniz University Hannover, Institute of Radioecology and Radiation Protection, Herrenhäuser Straße 2, D30419 Hannover (Germany); Hofhansl, Florian [University of Vienna, Department of Microbiology and Ecosystem Science, Althanstraße 14, A-1090 Vienna (Austria); Instituto Nacional de Pesquisas da Amazônia, Coordenação de Dinâmica Ambiental, Manaus (Brazil); Baumann, Nils [Helmholtz-Zentrum Dresden-Rossendorf, Division of Biogeochemistry, Bautzner Landstraße 400, D-01328 Dresden (Germany); Lichtscheidl, Irene K. [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria); Lang, Ingeborg, E-mail: ingeborg.lang@univie.ac.at [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria)

    2016-09-01

    Historic mining in the Eastern Alps has left us with a legacy of numerous spoil heaps hosting specific, metal tolerant vegetation. Such habitats are characterized by elevated concentrations of toxic elements but also by high irradiation, a poorly developed substrate or extreme pH of the soil. This study investigates the distribution of vascular plants, mosses and lichens on a copper spoil heap on the ore bearing Knappenberg formed by Prebichl Layers and Werfener Schist in Lower Austria. It serves as a model for discriminating between various ecological traits and their effects on vegetation. Five distinct clusters were distinguished: (1) The bare, metal rich Central Spoil Heap was only colonised by highly resistant specialists. (2) The Northern and (3) Southern Peripheries contained less copper; the contrasting vegetation was best explained by the different microclimate. (4) A forest over acidic bedrock hosted a vegetation overlapping with the periphery of the spoil heap. (5) A forest over calcareous bedrock was similar to the spoil heap with regard to pH and humus content but hosted a vegetation differing strongly to all other habitats. Among the multiple toxic elements at the spoil heap, only Cu seems to exert a crucial influence on the vegetation pattern. Besides metal concentrations, irradiation, humidity, humus, pH and grain size distribution are important for the establishment of a metal tolerant vegetation. The difference between the species poor Northern and the diverse Southern Periphery can be explained by the microclimate rather than by the substrate. All plant species penetrating from the forest into the periphery of the spoil heap originate from the acidic but not from the calcareous bedrock. - Highlights: • Strong impact on plant diversity by isolation and extreme abiotic conditions • Both, microclimate and substrate explain species distribution. • Increased cellular metal tolerance of plants from the Central Spoil Heap • Among toxic elements

  20. Fabrication of single-phase ε-GaSe films on Si(100) substrate by metal organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chang, Chia-Chen; Zeng, Jia-Xian; Lan, Shan-Ming; Uen, Wu-Yih; Liao, Sen-Mao; Yang, Tsun-Neng; Ma, Wei-Yang; Chang, Kuo-Jen

    2013-01-01

    Single-phase ε-gallium selenide (GaSe) films were fabricated on Si(100) substrate by metal organic chemical vapor deposition using dual-source precursors: triethylgallium (TEG) and hydrogen selenide (H 2 Se) with the flow ratio of [H 2 Se]/[TEG] being maintained at 1.2. In particular, an arsine (AsH 3 ) flow was introduced to the Si substrate before the film deposition to induce an arsenic (As)-passivation effect on the substrate. The crystalline structure of GaSe films prepared was analyzed using X-ray diffraction and the surface morphology of them was characterized by scanning electron microscopy. It was found that the film quality could be improved by the As-passivation effect. The optical properties of the films were studied by temperature dependent photoluminescence (PL) measurements. PL spectra obtained with different distributions and intensities favored for resolving the superior material quality of the films produced on the substrate with As-passivation compared to those produced on the substrate without As-passivation. The former was dominated by the excitonic emissions for the whole temperature range of 20–300 K examined, while the latter was initially dominated by the defect-related emission at 1.907 eV for a low-temperature range ≦ 80 K and then became dominated by the weak excitonic emission band instead. The ε modification of GaSe films prepared was further recognized by the Raman scattering measurements conducted at room temperature. - Highlights: • Gallium selenide (GaSe) layered structures are fabricated on Si(100) substrate. • Metal–organic chemical vapor deposition is used for film fabrication. • Arsenic-passivation effects of Si substrate on the GaSe film quality are analyzed. • Photoluminescence measurements of GaSe polycrystals are reported

  1. Influence of Nano-Crystal Metals on Texture and Biological Properties of Water Soluble Polysaccharides of Medicinal Plants

    Science.gov (United States)

    Churilov, G.; Ivanycheva, J.; Kiryshin, V.

    2015-11-01

    When treating the plants seeds with nano-materials there are some quality and quantity changes of polysaccharides, the molecular mass increase and monosaccharides change that leads to the increase of physiological and pharmacological activity of carbohydrates got from medicinal plants. We have got water soluble polysaccharides and nano-metals combinations containing 0.000165-0.000017 mg/dm3 of the metal. In a case of induced anemia the blood composition has practically restored on the 10th day of the treatment with nanocomposites. The use of pectin polysaccharides (that are attributed to modifiers of biological respond) to get nano-structured materials seems to be actual relative to their physiological activity (radio nuclides persorption, heavy metals ions, bacteria cells and their toxins; lipids metabolism normalization; bowels secreting and motor functions activation and modulation of the endocrine system.

  2. The Role of III-V Substrate Roughness and Deoxidation Induced by Digital Etch in Achieving Low Resistance Metal Contacts

    Directory of Open Access Journals (Sweden)

    Florent Ravaux

    2017-06-01

    Full Text Available To achieve low contact resistance between metal and III-V material, transmission-line-model (TLM structures of molybdenum (Mo were fabricated on indium phosphide (InP substrate on the top of an indium gallium arsenide (InGaAs layer grown by molecular beam epitaxy. The contact layer was prepared using a digital etch procedure before metal deposition. The contact resistivity was found to decrease significantly with the cleaning process. High Resolution Transmission & Scanning Electron Microscopy (HRTEM & HRSTEM investigations revealed that the surface roughness of treated samples was increased. Further analysis of the metal-semiconductor interface using Energy Electron Loss Spectroscopy (EELS showed that the amount of oxides (InxOy, GaxOy or AsxOy was significantly decreased for the etched samples. These results suggest that the low contact resistance obtained after digital etching is attributed to the combined effects of the induced surface roughness and oxides removal during the digital etch process.

  3. Catalytic transformations of biomass substrates using mixed metal oxides derived from substituted hydrotalcites

    Science.gov (United States)

    Macala, Gerald Stephen, II

    Fueled by seemingly endless reserves of cheap and easily accessible fossil energy, the industrial age has brought to the developed world tremendous advances in human health and well being. Unfortunately the burning of fossil fuels has also been implicated in increasing atmospheric CO2 concentrations and global climate change. Concerns about short-term and long-term supply further build a case for the need for alternative energy sources. Biomass derived materials are a tantalizing source of fuels and fine chemicals. Unlike petroleum derived hydrocarbons, biomass can be both renewable and carbon neutral. Crops can be regenerated annually or even more often in tropical climates, and since the captured carbon originates as atmospheric CO2, the overall cycle has the potential to be nearly carbon neutral regardless of the final fate of the carbon. In contrast to petroleum derived hydrocarbons, which can often be made more valuable by adding functionality, biomass derived materials are already highly functionalized and can usually be made more valuable by selective removal of functionality. The development of robust catalysts capable of selective defuntionalization of biomass derived substrates remains an important challenge with potentially enormous economic and societal impact. In addition to being robust and selective, catalysts should preferably be heterogeneous to allow for easier removal and regeneration after the reaction is complete. New materials consisting of Mg-Al hydrotalcite-like structures, with a limiting percentage of Mg or Al substituted with other M2+ or M3+ cations, were synthesized by a co-precipitation process in basic aqueous solution with carbonate as counterion. Calcination of these materials at 460 °C resulted in evolution of CO2 and water and yielded high surface area mixed metal oxides with enhanced reactivity. Materials were characterized by ICP for elemental analysis, XRD for structural information, XPS for surface elemental analysis and TEM

  4. FCC Rolling Textures Reviewed in the Light of Quantitative Comparisons between Simulated and Experimental Textures

    DEFF Research Database (Denmark)

    Wierzbanowski, Krzysztof; Wroński, Marcin; Leffers, Torben

    2014-01-01

    The crystallographic texture of metallic materials has a very strong effect on the properties of the materials. In the present article, we look at the rolling textures of fcc metals and alloys, where the classical problem is the existence of two different types of texture, the "copper-type texture......} slip without or with deformation twinning, but we also consider slip on other slip planes and slip by partial dislocations. We consistently make quantitative comparison of the simulation results and the experimental textures by means of a scalar correlation factor. We find that the development...

  5. Mineral formation on metallic copper in a `Future repository site environment`: Textural considerations based on natural analogs

    Energy Technology Data Exchange (ETDEWEB)

    Amcoff, Oe. [Uppsala Univ. (Sweden). Inst. of Earth Sciences

    1998-01-01

    Copper mineral formation in the Swedish `repository site environment` is discussed. Special attention is given to ore mineral textures (=the spatial relation among minerals), with examples given from nature. It is concluded: By analogy with observations from natural occurrences, an initial coating of Cu-oxide on the canister surface (because of entrapped air during construction) will probably not hinder a later sulphidation process. Early formation of Cu-sulphides on the canister surface may be accompanied by formation of CuFe-sulphides. The latter phase(s) may form through replacement of the Cu-sulphides or, alternatively, by means of reaction between dissolved copper and fine-grained iron sulphide (pyrite) in the surrounding bentonite. Should for some reason the bentonite barrier fail and the conditions become strongly oxidizing, we can expect crustifications and rhythmic growths of Cu(II)-phases, like malachite (Cu{sub 2}(OH){sub 2}CO{sub 3}). A presence of Fe{sup 2} in the clay minerals making up the bentonite might prove to have an adverse effect on the canister stability, since, in this case, the bentonite might be expected to act as a sink for dissolved copper. The mode of mineral growth along the copper - bentonite interface remains an open question.

  6. Influence of vicinal sapphire substrate on the properties of N-polar GaN films grown by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zhiyu; Zhang, Jincheng, E-mail: jchzhang@xidian.edu.cn; Xu, Shengrui; Chen, Zhibin; Yang, Shuangyong; Tian, Kun; Hao, Yue [Key Lab of Wide Band-Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi' an, Shaanxi 710071 (China); Su, Xujun [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123 (China); Shi, Xuefang [School of Advanced Materials and Nanotechnology, Xidian University, Xi' an, Shaanxi 710071 (China)

    2014-08-25

    The influence of vicinal sapphire substrates on the growth of N-polar GaN films by metal-organic chemical vapor deposition is investigated. Smooth GaN films without hexagonal surface feature are obtained on vicinal substrate. Transmission electron microscope results reveal that basal-plane stacking faults are formed in GaN on vicinal substrate, leading to a reduction in threading dislocation density. Furthermore, it has been found that there is a weaker yellow luminescence in GaN on vicinal substrate than that on (0001) substrate, which might be explained by the different trends of the carbon impurity incorporation.

  7. Investigation of the interfacial condition between bioceramic coatings and metallic substrates using guided waves

    Science.gov (United States)

    Saffari, Nader; Ong, Chuon-Szen

    2001-04-01

    The work reported here is on the characterization of the interfacial properties between plasma-sprayed Hydroxyapatite coatings on titanium substrates as used in cement-less hip orthopaedic implants. The phase velocity dispersion for the first Rayleigh-type mode for the coating-substrate system has been shown to be sensitive to the interfacial stiffness. Different interfacial conditions between the coating and substrate have been obtained by cyclic loading of the specimens in a four-point bend fatigue machine. The measured interfacial stiffness is then correlated with the interfacial fracture strength obtained by standard destructive shear tests.

  8. Highly textured Sr, Nb co-doped BiFeO3 thin films grown on SrRuO3/Si substrates by rf- sputtering

    International Nuclear Information System (INIS)

    Ostos, C.; Raymond, O.; Siqueiros, J. M.; Suarez-Almodovar, N.; Bueno-Baques, D.; Mestres, L.

    2011-01-01

    In this study, (011)-highly oriented Sr, Nb co-doped BiFeO 3 (BFO) thin films were successfully grown on SrRuO 3 /Si substrates by rf-magnetron sputtering. The presence of parasite magnetic phases was ruled out based on the high resolution x-ray diffraction data. BFO films exhibited a columnar-like grain growth with rms surface roughness values of ≅5.3 nm and average grain sizes of ≅65-70 nm for samples with different thicknesses. Remanent polarization values (2P r ) of 54 μC cm -2 at room temperature were found for the BFO films with a ferroelectric behavior characteristic of an asymmetric device structure. Analysis of the leakage mechanisms for this structure in negative bias suggests Schottky injection and a dominant Poole-Frenkel trap-limited conduction at room temperature. Oxygen vacancies and Fe 3+ /Fe 2+ trap centers are consistent with the surface chemical bonding states analysis from x-ray photoelectron spectroscopy data. The (011)-BFO/SrRuO 3 /Si film structure exhibits a strong magnetic interaction at the interface between the multiferroic film and the substrate layer where an enhanced ferromagnetic response at 5 K was observed. Zero-field cooled (ZFC) and field cooled (FC) magnetization curves of this film system revealed a possible spin glass behavior at spin freezing temperatures below 30 K depending on the BFO film thickness.

  9. Insulator-metal transition in substrate-independent VO2 thin film for phase-change devices.

    Science.gov (United States)

    Taha, Mohammad; Walia, Sumeet; Ahmed, Taimur; Headland, Daniel; Withayachumnankul, Withawat; Sriram, Sharath; Bhaskaran, Madhu

    2017-12-20

    Vanadium has 11 oxide phases, with the binary VO 2 presenting stimuli-dependent phase transitions that manifest as switchable electronic and optical features. An elevated temperature induces an insulator-to-metal transition (IMT) as the crystal reorients from a monoclinic state (insulator) to a tetragonal arrangement (metallic). This transition is accompanied by a simultaneous change in optical properties making VO 2 a versatile optoelectronic material. However, its deployment in scalable devices suffers because of the requirement of specialised substrates to retain the functionality of the material. Sensitivity to oxygen concentration and larger-scale VO 2 synthesis have also been standing issues in VO 2 fabrication. Here, we address these major challenges in harnessing the functionality in VO 2 by demonstrating an approach that enables crystalline, switchable VO 2 on any substrate. Glass, silicon, and quartz are used as model platforms to show the effectiveness of the process. Temperature-dependent electrical and optical characterisation is used demonstrating three to four orders of magnitude in resistive switching, >60% chromic discrimination at infrared wavelengths, and terahertz property extraction. This capability will significantly broaden the horizon of applications that have been envisioned but remained unrealised due to the lack of ability to realise VO 2 on any substrate, thereby exploiting its untapped potential.

  10. Films of Transition Metal Complexes Including Ionic Liquids: Dramatic Effects of Processing Parameters and Substrate on the Film Morphology

    Science.gov (United States)

    Bayatpour, Sareh; Isik, Dilek; Santato, Clara

    2018-01-01

    Bis(2-phenylpyridine- C, N)(2,2'-bipyridine- N, N') iridium(III) hexafluorophosphate ([Ir(ppy)2(bpy)][PF6]) is an ionic transition-metal complex (iTMC) of interest for use in light-emitting electrochemical cells (LEECs). Films of [Ir(ppy)2(bpy)][PF6] blended with the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]), deposited on different substrates, have been investigated for their morphological features, which are expected to affect the functional properties of the films, e.g., charge carrier transport. In literature, ionic liquids have been included in films of transition-metal complexes (TMCs) to increase the ion mobility and improve the performance of LEECs. A systematic comparison between the morphology of pure [Ir(ppy)2(bpy)][PF6] films and [Ir(ppy)2(bpy)][PF6] films containing [BMIm][PF6] has been carried out on different types of substrate, namely Au-patterned SiO2, indium tin oxide (ITO), and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-modified ITO. Although [Ir(ppy)2(bpy)][PF6] forms smooth films on SiO2, ITO, and PEDOT:PSS-modified ITO substrates, addition of [BMIm][PF6] caused formation of vertical, discontinuous aggregates, which are expected to be detrimental to charge transport in LEECs with planar architecture.

  11. Molecular beam epitaxy of quasi-freestanding transition metal disulphide monolayers on van der Waals substrates: a growth study

    Science.gov (United States)

    Hall, Joshua; Pielić, Borna; Murray, Clifford; Jolie, Wouter; Wekking, Tobias; Busse, Carsten; Kralj, Marko; Michely, Thomas

    2018-04-01

    Based on an ultra-high vacuum compatible two-step molecular beam epitaxy synthesis with elemental sulphur, we grow clean, well-oriented, and almost defect-free monolayer islands and layers of the transition metal disulphides MoS2, TaS2 and WS2. Using scanning tunneling microscopy and low energy electron diffraction we investigate systematically how to optimise the growth process, and provide insight into the growth and annealing mechanisms. A large band gap of 2.55 eV and the ability to move flakes with the scanning tunneling microscope tip both document the weak interaction of MoS2 with its substrate consisting of graphene grown on Ir(1 1 1). As the method works for the synthesis of a variety of transition metal disulphides on different substrates, we speculate that it could be of great use for providing hitherto unattainable high quality monolayers of transition metal disulphides for fundamental spectroscopic investigations.

  12. Stress Corrosion Cracking Susceptibility of 304L Substrate and 308L Weld Metal Exposed to a Salt Spray.

    Science.gov (United States)

    Hsu, Chia-Hao; Chen, Tai-Cheng; Huang, Rong-Tan; Tsay, Leu-Wen

    2017-02-15

    304 stainless steels (SS) were considered as the materials for a dry storage canister. In this study, ER (Electrode Rod) 308L was utilized as the filler metal for the groove and overlay welds of a 304L stainless steel substrate, which was prepared via a gas tungsten arc-welding process in multiple passes. The electron backscatter diffraction (EBSD) map was used to identify the inherent microstructures in distinct specimens. U-bend and weight-loss tests were conducted by testing the 304L substrates and welds in a salt spray containing 5 wt % NaCl at 80 °C to evaluate their susceptibility to stress corrosion cracking (SCC). Generally, the weight loss of the ER 308L deposit was higher than that of the 304L substrate in a salt spray in the same sample-prepared condition. The dissolution of the skeletal structure in the fusion zone (FZ) was responsible for a greater weight loss of the 308L deposit, especially for the cold-rolled and sensitized specimen. Cold rolling was detrimental and sensitization after cold rolling was very harmful to the SCC resistance of the 304L substrate and 308L deposit. Overall, the SCC susceptibility of each specimen was correlated with its weight loss in each group.

  13. Stress Corrosion Cracking Susceptibility of 304L Substrate and 308L Weld Metal Exposed to a Salt Spray

    Directory of Open Access Journals (Sweden)

    Chia-Hao Hsu

    2017-02-01

    Full Text Available 304 stainless steels (SS were considered as the materials for a dry storage canister. In this study, ER (Electrode Rod 308L was utilized as the filler metal for the groove and overlay welds of a 304L stainless steel substrate, which was prepared via a gas tungsten arc-welding process in multiple passes. The electron backscatter diffraction (EBSD map was used to identify the inherent microstructures in distinct specimens. U-bend and weight-loss tests were conducted by testing the 304L substrates and welds in a salt spray containing 5 wt % NaCl at 80 °C to evaluate their susceptibility to stress corrosion cracking (SCC. Generally, the weight loss of the ER 308L deposit was higher than that of the 304L substrate in a salt spray in the same sample-prepared condition. The dissolution of the skeletal structure in the fusion zone (FZ was responsible for a greater weight loss of the 308L deposit, especially for the cold-rolled and sensitized specimen. Cold rolling was detrimental and sensitization after cold rolling was very harmful to the SCC resistance of the 304L substrate and 308L deposit. Overall, the SCC susceptibility of each specimen was correlated with its weight loss in each group.

  14. Highly textured Sr, Nb co-doped BiFeO{sub 3} thin films grown on SrRuO{sub 3}/Si substrates by rf- sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ostos, C. [Universidad Nacional Autonoma de Mexico, Instituto de Investigaciones en Materiales, AP 70360, Mexico D.F. 04510 (Mexico); Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, AP 14, Ensenada B.C. 22890 (Mexico); Raymond, O.; Siqueiros, J. M. [Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, AP 14, Ensenada B.C. 22890 (Mexico); Suarez-Almodovar, N. [Universidad de La Habana, Facultad de Fisica-IMRE, San Lazaro y L, 10400, Louisiana Habana (Cuba); Bueno-Baques, D. [Centro de Investigacion en Quimica Aplicada, Enrique Reyna 140, Saltillo, Coah. 25253 (Mexico); Mestres, L. [Universitat de Barcelona, Facultat de Quimica, Av. Diagonal 648, 08028, Barcelona (Spain)

    2011-07-15

    In this study, (011)-highly oriented Sr, Nb co-doped BiFeO{sub 3} (BFO) thin films were successfully grown on SrRuO{sub 3}/Si substrates by rf-magnetron sputtering. The presence of parasite magnetic phases was ruled out based on the high resolution x-ray diffraction data. BFO films exhibited a columnar-like grain growth with rms surface roughness values of {approx_equal}5.3 nm and average grain sizes of {approx_equal}65-70 nm for samples with different thicknesses. Remanent polarization values (2P{sub r}) of 54 {mu}C cm{sup -2} at room temperature were found for the BFO films with a ferroelectric behavior characteristic of an asymmetric device structure. Analysis of the leakage mechanisms for this structure in negative bias suggests Schottky injection and a dominant Poole-Frenkel trap-limited conduction at room temperature. Oxygen vacancies and Fe{sup 3+}/Fe{sup 2+} trap centers are consistent with the surface chemical bonding states analysis from x-ray photoelectron spectroscopy data. The (011)-BFO/SrRuO{sub 3}/Si film structure exhibits a strong magnetic interaction at the interface between the multiferroic film and the substrate layer where an enhanced ferromagnetic response at 5 K was observed. Zero-field cooled (ZFC) and field cooled (FC) magnetization curves of this film system revealed a possible spin glass behavior at spin freezing temperatures below 30 K depending on the BFO film thickness.

  15. Performance characterization of metallic substrates coated by HVOF WC–Co

    International Nuclear Information System (INIS)

    Venter, Andrew M.; Oladijo, O. Philip; Luzin, Vladimir; Cornish, Lesley A.; Sacks, Natasha

    2013-01-01

    Integral to the performance of high-velocity oxygen-fuel (HVOF) coatings is the thermo-mechanical interaction associated with the thermal misfit, or differences in thermal expansion coefficients (CTEs), between coating and substrate. This investigation reports results on the microstructures, chemical phase content, coating–substrate misfit residual stress, and wear resistance. For this purpose a systematic characterization of WC–Co sprayed coatings on a number of substrates covering a range of CTE values were pursued for both the as-coated and heat-treated conditions. The neutron diffraction technique in conjunction with sub-millimeter sized gauge volumes enabled depth-resolved studies of the stress in the coatings and substrates by paying special attention to the determination of the stress contribution attributed by the final spray process. In the as-coated condition the stress values in the coatings were compressive for CTEs larger than that of WC–Co and tensile for CTE lower than WC–Co. Wear resistance increased for increased compressive stress and macrohardness. In the heat-treated condition, this trend became enhanced due to increased compressive stress in the coatings. - Highlights: • Four different substrate systems coated with HVOF WC-Co has been investigated. • Each substrate set encompassed the grit-blast surface and as-coated conditions, as well as their heat-treated counterparts. • Microstructural, macrohardness, wear performance and depth-resolved residual stress characterised. • Successful application of neutron strain scanning to investigating the combined systems, coatings and substrates. • Link observed between macrohardness, residual stress and wear performance

  16. Performance characterization of metallic substrates coated by HVOF WC–Co

    Energy Technology Data Exchange (ETDEWEB)

    Venter, Andrew M., E-mail: andrew.venter@necsa.co.za [Research and Development Division, Necsa Limited, Pretoria (South Africa); School of Chemical and Metallurgical Engineering, University of the Witwatersrand (South Africa); DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand (South Africa); Oladijo, O. Philip [School of Chemical and Metallurgical Engineering, University of the Witwatersrand (South Africa); DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand (South Africa); Luzin, Vladimir [ANSTO (Australian Nuclear Science and Technology Organisation), Lucas Height (Australia); Cornish, Lesley A.; Sacks, Natasha [School of Chemical and Metallurgical Engineering, University of the Witwatersrand (South Africa); DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand (South Africa)

    2013-12-31

    Integral to the performance of high-velocity oxygen-fuel (HVOF) coatings is the thermo-mechanical interaction associated with the thermal misfit, or differences in thermal expansion coefficients (CTEs), between coating and substrate. This investigation reports results on the microstructures, chemical phase content, coating–substrate misfit residual stress, and wear resistance. For this purpose a systematic characterization of WC–Co sprayed coatings on a number of substrates covering a range of CTE values were pursued for both the as-coated and heat-treated conditions. The neutron diffraction technique in conjunction with sub-millimeter sized gauge volumes enabled depth-resolved studies of the stress in the coatings and substrates by paying special attention to the determination of the stress contribution attributed by the final spray process. In the as-coated condition the stress values in the coatings were compressive for CTEs larger than that of WC–Co and tensile for CTE lower than WC–Co. Wear resistance increased for increased compressive stress and macrohardness. In the heat-treated condition, this trend became enhanced due to increased compressive stress in the coatings. - Highlights: • Four different substrate systems coated with HVOF WC-Co has been investigated. • Each substrate set encompassed the grit-blast surface and as-coated conditions, as well as their heat-treated counterparts. • Microstructural, macrohardness, wear performance and depth-resolved residual stress characterised. • Successful application of neutron strain scanning to investigating the combined systems, coatings and substrates. • Link observed between macrohardness, residual stress and wear performance.

  17. Crystal conversion between metal-organic frameworks with different crystal topologies for efficient crystal design on two-dimensional substrates

    Science.gov (United States)

    Tsuruoka, Takaaki; Inoue, Kohei; Miyanaga, Ayumi; Tobiishi, Kaho; Ohhashi, Takashi; Hata, Manami; Takashima, Yohei; Akamatsu, Kensuke

    2018-04-01

    Crystal conversion of metal-organic frameworks (MOFs) between different crystal topologies on a polymer substrate has been successfully achieved by localized dissolution of MOF crystals followed by a rapid self-assembly of framework components. Upon addition of the desired organic linkers to the reaction system containing MOF crystals on the substrate, reversible crystal conversion between the [Cu2(btc)3]n and [Cu2(ndc)2(dabco)]n frameworks (btc = 1,3,5-benzene tricarboxylate, ndc = 1,4-naphthalene dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane) could be routinely achieved in high yields. Most surprisingly, in the case of conversion from the [Cu2(ndc)2(dabco)]n to [Cu2(btc)3]n frameworks, the [Cu2(btc)3]n crystals with unique shapes (cuboctahedron and truncated cube) could be prepared using butanol as a reaction medium.

  18. Investigation on electrically-driven semiconductor-metal transition of polycrystalline VO2 thin films on two kinds of substrates

    Directory of Open Access Journals (Sweden)

    Deen Gu

    2018-01-01

    Full Text Available Electrical driving is one of frequently-used stimuli for the semiconductor-metal transition (SMT of VO2. But the driving mechanism is still under debate. We investigated the DC electrically-driven SMT features of polycrystalline VO2 thin films deposited on two kinds of substrates (quartz and silicon with obviously-different thermal conductivity and the influence of cooling by a thermo electric cooler (TEC on the SMT of VO2. Interestingly, the SMT doesn’t happen at a high voltage at very start, but at a relatively low one. Moreover, the SMT of VO2 thin films on silicon substrate is completely restrained by cooling through a TEC although the electric field strength across VO2 reaches 1.1×107 V/m. Our findings reveal that the Joule-heating effect plays an important role in the DC electrically-driven SMT of VO2.

  19. Effect of pH, various divalent metal ion and different substrates on ...

    African Journals Online (AJOL)

    EZUGWU ARINZE LINUS

    Key words: Glucoamylase, pH, metal ions, Aspergillus niger, tiger nut starch, amylopectin. INTRODUCTION. Glucoamylase (α-1 ... glycosidic bonds from the non-reducing ends of starch and 1,6-alpha-glucsidic linkages in ..... stable at neutral pH 7.0, it is more likely to readily form neucleophilichydroxide ions with metals by ...

  20. State of the art and prospective of large scale applications of YBCO thick films grown on metallic substrates

    International Nuclear Information System (INIS)

    Boffa, Vincenzo

    1997-09-01

    In the framework of the high temperature superconducting materials, YBa 2 Cu 3 O 7 (YBCO) shows very interesting intrinsic superconducting transport properties at temperature higher than the liquid nitrogen temperature. These properties are very important in large scale applications: transport of energy, magnets, transformers, etc. Unfortunately the potential of this material cannot be achieved today, since it is very difficult to manufacture YBCO based tapes or cables. In the last years several groups have tried to overcome the problems with new fabrication techniques. In the present report the state of the art and the prospective in the field of YBCO film fabrication on metallic substrates are presented

  1. High performance SERS on nanoporous gold substrates synthesized by chemical de-alloying a Au-based metallic glass

    Science.gov (United States)

    Xue, Yanpeng; Scaglione, Federico; Rizzi, Paola; Battezzati, Livio

    2017-12-01

    A Au20Cu48Ag7Pd5Si20 metallic glass precursor has been used to synthesize nanoporous gold by chemical de-alloying in a mixture of HNO3 and HF. Gold ligaments of size ranging from 45 to 100 nm were obtained as a function of HNO3 concentration, electrolyte temperature and de-alloying time. The as-prepared nanoporous gold exhibited strong surface enhanced Raman scattering (SERS) effect using 4,4‧-bi-pyridine as probe molecule. For application in melamine sensing, the detection limit of 10-6 M was achieved, which indicated that this biocompatible material has great potential as SERS active substrate.

  2. Near-field microwave detection of corrosion precursor pitting under thin dielectric coatings in metallic substrate

    International Nuclear Information System (INIS)

    Hughes, D.; Zoughi, R.; Austin, R.; Wood, N.; Engelbart, R.

    2003-01-01

    Detection of corrosion precursor pitting on metallic surfaces under various coatings and on bare metal is of keen interest in evaluation of aircraft fuselage. Near-field microwave nondestructive testing methods, utilizing open-ended rectangular waveguides and coaxial probes, have been used extensively for detection of surface flaws in metals, both on bare metal and under a dielectric coating. This paper presents the preliminary results of using microwave techniques to detect corrosion precursor pitting under paint and primer, applique and on bare metal. Machined pits of 500 μm diameter were detected using open-ended rectangular waveguides at V-Band under paint and primer and applique, and on bare metal. Using coaxial probes, machined pits with diameters down to 150 μm on bare metal were also detected. Relative pit size and density were shown on a corrosion-pitted sample using open-ended rectangular waveguides at frequencies of 35 GHz to 70 GHz. The use of Boeing's MAUS TM scanning systems provided improved results by alleviating standoff variation and scanning artifact. Typical results of this investigation are also presented

  3. Infrared-transmittance tunable metal-insulator conversion device with thin-film-transistor-type structure on a glass substrate

    Directory of Open Access Journals (Sweden)

    Takayoshi Katase

    2017-05-01

    Full Text Available Infrared (IR transmittance tunable metal-insulator conversion was demonstrated on a glass substrate by using thermochromic vanadium dioxide (VO2 as the active layer in a three-terminal thin-film-transistor-type device with water-infiltrated glass as the gate insulator. Alternative positive/negative gate-voltage applications induce the reversible protonation/deprotonation of a VO2 channel, and two-orders of magnitude modulation of sheet-resistance and 49% modulation of IR-transmittance were simultaneously demonstrated at room temperature by the metal-insulator phase conversion of VO2 in a non-volatile manner. The present device is operable by the room-temperature protonation in an all-solid-state structure, and thus it will provide a new gateway to future energy-saving technology as an advanced smart window.

  4. The role of substrate electrons in the wetting of a metal surface

    DEFF Research Database (Denmark)

    Schiros, T.; Takahashi, O.; Andersson, Klas Jerker

    2010-01-01

    We address how the electronic and geometric structures of metal surfaces determine water-metal bonding by affecting the balance between Pauli repulsion and electrostatic attraction. We show how the rigid d-electrons and the softer s-electrons utilize different mechanisms for the redistribution...... of charge that enables surface wetting. On open d-shell Pt(111), the ligand field of water alters the distribution of metal d-electrons to reduce the repulsion. The closed-shell Cu d(10) configuration of isostructural Cu(111), however, does not afford this mechanism, resulting in a hydrophobic surface...

  5. Investigation of photocatalytic activity of titanium dioxide deposited on metallic substrates by DC magnetron sputtering

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Canulescu, Stela; Dirscherl, Kai

    2013-01-01

    The photocatalytic properties of titanium dioxide (TiO2) coating in the anatase crystalline structure deposited on aluminium AA1050 alloy and stainless steel S316L substrates were investigated. The coating was prepared by DC magnetron sputtering. The microstructure and surface morphology...

  6. Oxidative damage to collagen and related substrates by metal ion/hydrogen peroxide systems

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1997-01-01

    (II)-H2O2, evidence has been obtained for: i) altered sites of attack and fragmentation, ii) C-terminal decarboxylation, and iii) hydrogen abstraction at N-terminal alpha-carbon sites. This altered behaviour is believed to be due to the binding of copper ions to some substrates and hence site...

  7. Metal-free magnetic conductor substrates for placement-immune antenna assemblies

    Science.gov (United States)

    Eubanks, Travis Wayne; Loui, Hung; McDonald, Jacob Jeremiah

    2015-09-29

    A magnetic conductor substrate produced for mounting to an antenna includes a sheet of dielectric lattice material having a length, a width and a thickness that is less than the length and less than the width. Within the sheet of dielectric lattice material is disposed an array of dielectric elements.

  8. Strontium Titanate Buffer Layers on Cu/33%Ni Substrates using a Novel Solution Chemistry

    DEFF Research Database (Denmark)

    Pallewatta, Pallewatta G A P; Yue, Zhao; Hui, Tian

    2013-01-01

    SrTiO3 is a widely studied perovskite material due to its advantages as a buffer template which can be simply applied between a metal substrate tape and a superconducting layer in 2G high temperature superconducting (HTS) tapes. In this study, heteroepitaxial SrTiO3 thin films were deposited...... on textured Cu/33%Ni substrates using dip-coating in a precursor solution followed by drying and annealing under controlled oxygen partial pressures. The control of the ambient atmosphere during annealing is an important experimental issue in order to achieve thin films with high quality surface texture. We...

  9. Limitation of current hardening models in predicting anisotropy by twinning in hcp metals: Application to a rod-textured AM30 magnesium alloy

    Science.gov (United States)

    Oppedal, A. L.; El Kadiri, H.; Tomé, C. N.; Baird, J. C.; Vogel, S. C.; Horstemeyer, M. F.

    When a strongly textured hexagonal close packed (HCP) metal is loaded under an orientation causing profuse twinning or detwinning, the stress-strain curve is sigmoidal in shape and inflects at some threshold. Authors have largely attributed the dramatic stress increase in the lower-bound vicinity of the inflection point to a combined effect of a Hall-Petch mechanism correlated to grain refinement by twinning, and twinning-induced reorientation requiring activation of hard slip modes. We experimentally and numerically demonstrate that these two mechanisms alone are unable to reproduce the stress-strain behaviors obtained under intermediate loading orientations correlated to in-between profuse twinning and nominal twinning. We argue based on adopting various mechanistic approaches in hardening model correlations from the literature. We used both a physics dislocation based model and a phenomenological Voce hardening model. The HCP material is exemplified by an extruded AM30 magnesium alloy with a < {10\\bar 10} \\rangle-fiber parallel to the extrusion direction.

  10. Real-time texture experiments

    International Nuclear Information System (INIS)

    Juul Jensen, D.

    1985-01-01

    A technique for fast in-situ texture determination by neutron diffraction is described. The basic instrument is variable wavelength neutron spectrometer modified to incorporate a linear position-sensitive detector and a fully automatic Eulergoniometer. At present a complete textural analysis with an accuracy of 2-3% determined by counting statistics, requires from 15 to 30 minutes measuring time depending on the sample material. By on-line recording of the change in texture, which commonly accompanies such processes as deformation, recrystallization and grain growth in crystalline materials, information about the process and its kinetics is obtained. This is illustrated by in-situ kinetic investigations of recrystallization and grain growth in various polycrystalline metals; the potential of the technique for problems related to metallurgical practice is demonstrated by an approach of texture tailoring in commercially pure aluminium. (author)

  11. Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

    International Nuclear Information System (INIS)

    Sujan, G.K.; Haseeb, A.S.M.A.; Afifi, A.B.M.

    2014-01-01

    Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu 6 Sn 5 from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping of flux

  12. Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sujan, G.K., E-mail: sgkumer@gmail.com; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Afifi, A.B.M., E-mail: amalina@um.edu.my

    2014-11-15

    Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu{sub 6}Sn{sub 5} from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping

  13. Growth of ZnO nanowires through thermal oxidation of metallic zinc films on CdTe substrates

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, O., E-mail: oscar@fmc.uva.es [Optronlab Group, Dpto. Fisica Materia Condensada, Edificio I-D, Universidad de Valladolid, Paseo de Belen 1, 47011, Valladolid (Spain); Hortelano, V.; Jimenez, J. [Optronlab Group, Dpto. Fisica Materia Condensada, Edificio I-D, Universidad de Valladolid, Paseo de Belen 1, 47011, Valladolid (Spain); Plaza, J.L.; Dios, S. de; Olvera, J.; Dieguez, E. [Laboratorio de Crecimiento de Cristales, Departamento de Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Fath, R.; Lozano, J.G.; Ben, T.; Gonzalez, D. [Dpto. Ciencia de los Materiales e Ingenieria Metalurgica y Q.I., Facultad de Ciencias, Apdo. 40, 11510 Puerto Real, Cadiz (Spain); Mass, J. [Dpto. de Fisica, Universidad del Norte, Km.5 Via Puerto Colombia, Barranquilla (Colombia)

    2011-04-28

    Research highlights: > ZnO nanowires grown from thermal Zn oxidation. > TEM reveals high quality thin nanowires several microns long. > New phase formation at long oxidation time. > Good spectroscopic properties measured by Raman, Photo and Cathodoluminsecence spectroscopies. - Abstract: <112-bar 0> wurtzite ZnO nanowires (NWs) have been obtained by oxidizing in air at 500 deg. C thermally evaporated Zn metal films deposited onto CdTe substrates. The presence of Cd atoms from the substrate on the ZnO seeding layer and NWs seems to affect the growth of the NWs. The effects of the oxidation time on the structural and optical properties of the NWs are described in detail. It is shown that the NWs density decreases and their length increases when increasing the oxidation time. Thicker Zn layers result in thinner and longer ZnO NWs. Very long oxidation times also lead to the formation of a new CdO phase which is related to the partial destruction and quality reduction of the NWs. The possible process for ZnO NW formation on CdTe substrates is discussed.

  14. Phytochelatin-metal(loid) transport into vacuoles shows different substrate preferences in barley and Arabidopsis.

    Science.gov (United States)

    Song, Won-Yong; Mendoza-Cózatl, David G; Lee, Youngsook; Schroeder, Julian I; Ahn, Sang-Nag; Lee, Hyun-Sook; Wicker, Thomas; Martinoia, Enrico

    2014-05-01

    Cadmium (Cd) and arsenic (As) are toxic to all living organisms, including plants and humans. In plants, Cd and As are detoxified by phytochelatins (PCs) and metal(loid)-chelating peptides and by sequestering PC-metal(loid) complexes in vacuoles. Consistent differences have been observed between As and Cd detoxification. Whereas chelation of Cd by PCs is largely sufficient to detoxify Cd, As-PC complexes must be sequestered into vacuoles to be fully detoxified. It is not clear whether this difference in detoxification pathways is ubiquitous among plants or varies across species. Here, we have conducted a PC transport study using vacuoles isolated from Arabidopsis and barley. Arabidopsis vacuoles accumulated low levels of PC2 -Cd, and vesicles from yeast cells expressing either AtABCC1 or AtABCC2 exhibited negligible PC2 -Cd transport activity compared with PC2 -As. In contrast, barley vacuoles readily accumulated comparable levels of PC2 -Cd and PC2 -As. PC transport in barley vacuoles was inhibited by vanadate, but not by ammonium, suggesting the involvement of ABC-type transporters. Interestingly, barley vacuoles exhibited enhanced PC2 transport activity when essential metal ions, such as Zn(II), Cu(II) and Mn(II), were added to the transport assay, suggesting that PCs might contribute to the homeostasis of essential metals and detoxification of non-essential toxic metal(loid)s. © 2013 John Wiley & Sons Ltd.

  15. Phytochelatin–metal(loid) transport into vacuoles shows different substrate preferences in barley and Arabidopsis

    Science.gov (United States)

    Song, Won-Yong; Mendoza-Cózatl, David G.; Lee, Youngsook; Schroeder, Julian I.; Ahn, Sang-Nag; Lee, Hyun-Sook; Wicker, Thomas; Martinoia, Enrico

    2014-01-01

    Cadmium (Cd) and arsenic (As) are toxic to all living organisms, including plants and humans. In plants, Cd and As are detoxified by phytochelatins (PCs) and metal(loid)-chelating peptides and by sequestering PC–metal(loid) complexes in vacuoles. Consistent differences have been observed between As and Cd detoxification. Whereas chelation of Cd by PCs is largely sufficient to detoxify Cd, As–PC complexes must be sequestered into vacuoles to be fully detoxified. It is not clear whether this difference in detoxification pathways is ubiquitous among plants or varies across species. Here, we have conducted a PC transport study using vacuoles isolated from Arabidopsis and barley. Arabidopsis vacuoles accumulated low levels of PC2–Cd, and vesicles from yeast cells expressing either AtABCC1 or AtABCC2 exhibited negligible PC2–Cd transport activity compared with PC2–As. In contrast, barley vacuoles readily accumulated comparable levels of PC2–Cd and PC2–As. PC transport in barley vacuoles was inhibited by vanadate, but not by ammonium, suggesting the involvement of ABC-type transporters. Interestingly, barley vacuoles exhibited enhanced PC2 transport activity when essential metal ions, such as Zn(II), Cu(II) and Mn(II), were added to the transport assay, suggesting that PCs might contribute to the homeostasis of essential metals and detoxification of non-essential toxic metal(loid)s. PMID:24313707

  16. Corrosion Monitoring of Flexible Metallic Substrates for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Trystan Watson

    2013-01-01

    Full Text Available Two techniques for monitoring corrosion within a dye-sensitized solar cell (DSC system are presented, which enable continuous, high sensitivity, in situ measurement of electrolyte breakdown associated with DSCs fabricated on metals. The first method uses UV/Vis reflectance spectrophotometry in conjunction with encapsulation cells, which incorporate a 25 μm thick electrolyte layer, to provide highly resolved triiodide absorption data. The second method uses digital image capture to extract colour intensity data. Whilst the two methods provide very similar kinetic data on corrosion, the photographic method has the advantage that it can be used to image multiple samples in large arrays for rapid screening and is also relatively low cost. This work shows that the triiodide electrolyte attacks most metals that might be used for structural applications. Even a corrosion resistant metal, such as aluminium, can be induced to corrode through surface abrasion. This result should be set in the context with the finding reported here that certain nitrogen containing heterocyclics used in the electrolyte to enhance performance also act as corrosion inhibitors with significant stabilization for metals such as iron. These new techniques will be important tools to help develop corrosion resistant metal surfaces and corrosion inhibiting electrolytes for use in industrial scale devices.

  17. Nano-/micro metallic wire synthesis on Si substrate and their characterization

    International Nuclear Information System (INIS)

    Kaur, Jaskiran; Kaur, Harmanmeet; Singh, Surinder; Kanjilal, Dinakar; Chakarvarti, Shiv Kumar

    2014-01-01

    Nano-/micro wires of copper are grown on semiconducting Si substrate using the template method. It involves the irradiation of 8 um thick polymeric layer coated on Si with150 MeV Ni ion beam at a fluence of 2E8. Later, by using the simple technique of electrodeposition, copper nano-/micro wires were grown via template synthesis. Synthesized wires were morphologically characterized using SEM and electrical characterization was carried out by finding I-V plot

  18. Metallic substrate materials for thin film oxygen transport membranes for application in a fossil power plant

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Y.; Baumann, S.; Sebold, D.; Meulenberg, W.A.; Stoever, D. [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF) - IEF-1 Materials Synthesis and Processing

    2010-07-01

    La{sub 0.58}Sr{sub 0.4}CO{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58428) and Ba{sub 0.5}Sr{sub 0.5}CO{sub 0.8}Fe{sub 3-{delta}} (BSCF5582) exhibit high oxygen permeability due to their high ionic and electronic conductivity. For this reason they are under discussion for application in oxygen transport membranes (OTMs) in zero-emission power plants using oxyfuel technology. A thin film membrane which can increase the oxygen flux is beneficial and a structural substrate is required. Two types of Ni-base alloys were studied as substrate material candidates with a number of advantages, such as high strength, high temperature stability, easy joining and similar thermal expansion coefficient to the selected perovskite materials. Chemical compositions and thermal expansion coefficients of Ni-base alloys were measured in this study. LSCF58428 and BSCF5582 layers were screen printed on Ni-based alloys and co-fired at high temperature in air. The microstructure and element analysis of samples were characterized by scanning electron microscopy (SEM and EDX). A Ni-base alloy, MCrAlY, with a high Al content was the most suitable substrate material, and showed better chemical compatibility with perovskite materials at high temperature than Hastelloy X, which is a chromia-forming Ni-base alloy. A reaction occurred between Sr in the perovskite and the alumina surface layers on MCr-AlY. However, the reaction zone did not increase in thickness during medium-term annealing at 800 C in air. Hence, it is expected that this reaction will not prevent the application of MCr-AlY as a substrate material. (orig.)

  19. Laser engineered multilayer coating of biphasic calcium phosphate/titanium nanocomposite on metal substrates.

    Science.gov (United States)

    Zhang, Martin Yi; Ye, Chang; Erasquin, Uriel Joseph; Huynh, Toan; Cai, Chengzhi; Cheng, Gary J

    2011-02-01

    In this work, laser coating of biphasic calcium phosphate/titanium (BCP/Ti) nanocomposite on Ti-6Al-4 V substrates was developed. A continuous wave neodymium-doped yttrium aluminium garnet (Nd:YAG) laser was used to form a robust multilayer of BCP/Ti nanocomposite starting from hydroxyapatite and titanium nanoparticles. In this process, low power coating is realized because of the strong laser-nanoparticle interaction and good sinterability of nanosized titanium. To guide the optimization of laser processing conditions for the coating process, a multiphysics model coupling electromagnetic module with heat transfer module was developed. This model was validated by laser coating experiments. Important features of the coated samples, including microstructures, chemical compositions, and interfacial bonding strength, were characterized. We found that a multilayer of BCP, consisting of 72% hydroxyapatite (HA) and 28% beta-tricalcium phosphate (β-TCP), and titanium nanocomposite was formed on Ti-6Al-4 V substrates. Significantly, the coating/substrate interfacial bonding strength was found to be two times higher than that of the commercial plasma sprayed coatings. Preliminary cell culture studies showed that the resultant BCP/Ti nanocomposite coating supported the adhesion and proliferation of osteoblast-like UMR-106 cells.

  20. Quantum electron states and resonances in thin monocrystal layers of noble metals on W (110) substrate

    CERN Document Server

    Vyalykh, D V; Prudnikova, G V; Grigoriev, A Y; Starodubov, A G; Adamchuk, V K

    2002-01-01

    For the first time in monocrystal layers of gold, silver and copper formed at W (110) single crystal surface one observed experimentally electron states and resonances of s p-type. They resulted from spatial localization of the Bloch type electron wave functions in quantum pit with potential barriers formed by vacuum/metal and metal/W (110) interfaces. One applied photoelectron spectroscopy with angular resolution to investigate experimentally into quantization of an electron structure of a valence band in Au/W (110), Ag/W (110) and Cu/W (110) systems

  1. On the origin of recrystallization textures

    Indian Academy of Sciences (India)

    Unknown

    specially oriented grains have a high mobility boundary and thus can migrate faster and grow to a larger size as compared to random orientations thus contributing to the final recrystallization texture. In FCC metals and alloys like aluminium, cube orientation [(001) 〈100〉] is the recrystallization texture component.

  2. On the origin of recrystallization textures

    Indian Academy of Sciences (India)

    Unknown

    specially oriented grains have a high mobility boundary and thus can migrate faster and grow to a larger size as compared to random orientations thus contributing to the final recrystallization texture. In FCC metals and alloys like aluminium, cube orientation [(001) 〈100〉] is the recrystallization texture component. In the ...

  3. Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Latifi, Afrooz, E-mail: afroozlatifi@yahoo.com [Department of Biomaterials, Biomedical Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Imani, Mohammad [Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran (Iran, Islamic Republic of); Khorasani, Mohammad Taghi [Biomaterials Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/159, Tehran (Iran, Islamic Republic of); Daliri Joupari, Morteza [Animal and Marine Biotechnology Dept., National Institute of Genetic Engineering and Biotechnology, P.O. Box 14965/161, Tehran (Iran, Islamic Republic of)

    2014-11-30

    Highlights: • Stainless steel 316L was surface modified by plasma surface oxidation (PSO) and silicone rubber (SR) coating. • On the PSO substrates, concentration of oxide species was increased ca. 2.5 times comparing to non-PSO substrates. • The surface wettability was improved to 12.5°, in terms of water contact angle, after PSO. • Adhesion strength of SR coating on the PSO substrates was improved by more than two times comparing to non-PSO ones. • After pull-off test, the fractured area patterns for SR coating were dependent on the type of surface modifications received. - Abstract: Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m{sup −1}), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer–metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

  4. Long range wetting transparency on top of layered metal dielectric substrates

    Science.gov (United States)

    2015-11-20

    and classical physics, involving electronic interactions and transitions in a broad range of frequencies, depend not only on the local dielectric...controlled by the vicinity of metamaterials and metallic surfaces and which do not always belong to the traditional domain of electrodynamics include

  5. Application of carbohydrate polymers as corrosion inhibitors for metal substrates in different media: A review.

    Science.gov (United States)

    Umoren, Saviour A; Eduok, Ubong M

    2016-04-20

    Naturally occurring polysaccharides are biopolymers existing as products of biochemical processes in living systems. A wide variety of them have been employed for various material applications; as binders, coatings, drug delivery, corrosion inhibitors etc. This review describes the application of some green and benign carbohydrate biopolymers and their derivatives for inhibition of metal corrosion. Their modes and mechanisms of protection have also been described as directly related to their macromolecular weights, chemical composition and their unique molecular and electronic structures. For instance, cellulose and chitosan possess free amine and hydroxyl groups capable of metal ion chelation and their lone pairs of electrons are readily utilized for coordinate bonding at the metal/solution interface. Some of the carbohydrate polymers reviewed in this work are either pure or modified forms; their grafted systems and nanoparticle composites with multitude potentials for metal protection applications have also been highlighted. Few inhibitors grafted to introduce more compact structures with polar groups capable of increasing the total energy of the surface have also been mentioned. Exudate gums, carboxymethyl and hydroxyethyl cellulose, starch, pectin and pectates, substituted/modified chitosans, carrageenan, dextrin/cyclodextrins and alginates have been elaborately reviewed, including the effects of halide additives on their anticorrosion performances. Aspects of computational/theoretical approach to corrosion monitoring have been recommended for future studies. This non-experimental approach to corrosion could foster a better understanding of the corrosion inhibition processes by correlating actual inhibition mechanisms with molecular structures of these carbohydrate polymers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Theoretical simulations of atomic and polyatomic bombardment of an organic overlayer on a metallic substrate

    CERN Document Server

    Krantzman, K D; Delcorte, A; Garrison, B J

    2003-01-01

    Our previous molecular dynamics simulations on initial test systems have laid the foundation for understanding some of the effects of polyatomic bombardment. In this paper, we describe simulations of the bombardment of a more realistic model system, an overlayer of sec-butyl-terminated polystyrene tetramers on a Ag left brace 1 1 1 right brace substrate. We have used this model system to study the bombardment with Xe and SF sub 5 projectiles at kinetic energies ranging from 0.50 to 5.0 keV. SF sub 5 sputters more molecules than Xe, but a higher percentage of these are damaged rather than ejected intact when the bombarding energy is greater than 0.50 keV. Therefore, at energies comparable to experimental values, the efficiency, measured as the yield-to-damage ratio, is greater with Xe than SF sub 5. Stable and intact molecules are generally produced by upward moving substrate atoms, while fragments are produced by the upward and lateral motion of reflected projectile atoms and fragments from the target molecul...

  7. Experimental studies on the effect of different metallic substrates on marine biofouling.

    Science.gov (United States)

    Vedaprakash, L; Dineshram, R; Ratnam, Krupa; Lakshmi, K; Jayaraj, K; Mahesh Babu, S; Venkatesan, R; Shanmugam, A

    2013-06-01

    In the wake of adoption of the resolution by the International Maritime Organization to control biofouling on vessels, which is recognized as a major vector for transfer of invasive species, this study attempts to create a baseline data on major hard-shelled biofouling organisms in the harbour waters. This study was primarily focused towards understanding the biofouling and corrosion pattern on various metals and their performance under immersed condition in a marine environment, at 0.3 and 3.0m depths. Furthermore, the study attempts to understand the surface dependent characteristics of barnacle base plate and its adhesion strength. Barnacle, mussels and oysters were the major fouling organisms accounting for 72.33% of the variation. Stainless steel and Titanium panels showed the highest average biofouling load of 176.36 and 168.35 g/300 cm(2), respectively. The variance in biofouling between metals and depths was highly significant at p<0.001 and p<0.01, respectively. Morphology of barnacle base plate interfacial surface varied between metals. Barnacles with 8-9 mm base diameter showed the maximum adhesion strength in shear of 6.86±0.95 kPa. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Metal Oxide Nanostructures Generated from In Situ Sacrifice of Zinc in Bimetallic Textures as Flexible Ni/Fe Fast Battery Electrodes.

    Science.gov (United States)

    Huang, Tianyi; Liu, Zhifang; Zhang, Zitong; Xiao, Bangqing; Jin, Yong

    2017-08-04

    An "in situ sacrifice" process was devised in this work as a room-temperature, all-solution processed electrochemical method to synthesize nanostructured NiO x and FeO x directly on current collectors. After electrodepositing NiZn/FeZn bimetallic textures on a copper net, the zinc component is etched and the remnant nickel/iron are evolved into NiO x and FeO x by the "in situ sacrifice" activation we propose. As-prepared electrodes exhibit high areal capacities of 0.47 mA h cm -2 and 0.32 mA h cm -2 , respectively. By integrating NiO x as the cathode, FeO x as the anode, and poly(vinyl alcohol) (PVA)-KOH gel as the separator/solid-state electrolyte, the assembled quasi-solid-state flexible battery delivers a volumetric capacity of 6.91 mA h cm -3 at 5 mA cm -2 , along with a maximum energy density of 7.40 mWh cm -3 under a power density of 0.27 W cm -3 and a maximum tested power density of 3.13 W cm -3 with a 2.17 mW h cm -3 energy density retention. Our room-temperature synthesis, which only consumes minute electricity, makes it a promising approach for large-scale production. We also emphasize the in situ sacrifice zinc etching process used in this work as a general strategy for metal-based nanostructure growth for high-performance battery materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Fabrication of 5 cm long epitaxial Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} single buffer layer on textured Ni-5%W substrate for YBCO coated conductors via dip-coating PACSD method

    Energy Technology Data Exchange (ETDEWEB)

    Lei, M.; Wang, W.T.; Pu, M.H.; Yang, X.S.; He, L.J. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Science and Engineering, University of New South Wales, Sydney 2052, New South Wales (Australia); Zhao, Y., E-mail: yzhao@home.swjtu.edu.cn [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)] [Science and Engineering, University of New South Wales, Sydney 2052, New South Wales (Australia)

    2011-11-15

    Epitaxial Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} single buffer layer for YBCO coated conductors was deposited via fluorine-free dip-coating CSD. Flat, dense and crack-free SCO films with sharp (2 0 0) c-axis texture were obtained by carefully controlling the processing. YBCO thin films with a homogeneous surface microstructure were deposited on the SCO-buffered NiW substrate via CSD approach. Five centimeters long epitaxial Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} (SCO) single buffer layer for YBCO coated conductors was deposited via dip-coating polymer-assisted chemical solution deposition (PACSD) approach on bi-axially textured Ni-5%W (2 0 0) alloy substrate. The film formation and texture evolution were investigated using X-ray diffraction and scanning electron microscopy. Flat, dense and crack-free SCO films with sharp (2 0 0) c-axis texture were obtained by way of carefully controlling the concentration of precursor solution, withdrawing speed, annealing temperature and dwelling time. On consideration of both microstructure and texture, epitaxial SCO single buffer layers were fabricated using precursor solution of 0.3 M cationic concentration, the withdrawing speed of 10 mm/min and heat treatment at 1100 deg. C in Ar-5%H{sub 2} mixture gas for 0.5 h. Epitaxial YBCO thin films with a homogeneous surface microstructure were deposited on the SCO-buffered NiW substrate via dip-coating PACSD approach. The PACSD approach was a promising way to fabricate long and low-cost YBCO coated conductors.

  10. Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

    KAUST Repository

    Park, Soohyung

    2018-01-03

    Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron–hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

  11. Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

    Science.gov (United States)

    Park, Soohyung; Mutz, Niklas; Schultz, Thorsten; Blumstengel, Sylke; Han, Ali; Aljarb, Areej; Li, Lain-Jong; List-Kratochvil, Emil J. W.; Amsalem, Patrick; Koch, Norbert

    2018-04-01

    Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron-hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

  12. Preparation of a Novel Ce0.9La0.1O2/Gd2Zr2O7 Buffer Layer Stack on NiW Alloy Substrates by the MOD Route

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; Abrahamsen, Asger Bech

    2011-01-01

    An optimized buffer layer architecture prepared by a metal organic deposition method on biaxially textured metallic substrate is proposed and developed successfully. The major achievement of this work is to choose a ${\\rm Ce}_{0.9}{\\rm La}_{0.1}{\\rm O}_{2}$ layer as cap layer that possesses an ex...

  13. InAs/GaSb core-shell nanowires grown on Si substrates by metal-organic chemical vapor deposition

    Science.gov (United States)

    Ji, Xianghai; Yang, Xiaoguang; Du, Wenna; Pan, Huayong; Luo, Shuai; Ji, Haiming; Xu, Hongqi; Yang, Tao

    2017-06-01

    We report the growth of InAs/GaSb core-shell heterostructure nanowires with smooth sidewalls on Si substrates using metal-organic chemical vapor deposition (MOCVD) with no assistance from foreign catalysts. Sb adatoms were observed to strongly influence the morphology of the GaSb shell. In particular, Ga droplets form on the nanowire tips when a relatively low TMSb flow rate is used, whereas the droplets are missing and the radial growth of the GaSb is enhanced due to a reduction in the diffusion length of the Ga adatoms when the TMSb flow rate is increased. Moreover, transmission electron microscopy measurements revealed that the GaSb shell coherently grew on the InAs core without any misfit dislocations.

  14. Recent advances and perspectives in analytical methodologies for monitoring the bioavailability of trace metals in environmental solid substrates

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald

    2006-01-01

    In the last decades, researchers have realised that the impact of trace elements (TE) in environmental solid substrates on ecological systems and biota cannot be ascertained appropriately by means of total metal content measurements. Assessment of TE chemical forms, types of binding and reactivity...... of their associations with particulate forms has, thus, been commonly performed via batch-wise equilibrium-based sequential extraction fractionation methods able to discern TE bound to different soil-phase compartments. In this paper, novel analytical strategies for monitoring the mobility, bioavailability...... and the eventual impact of anthropogenic TE in environmental solids are addressed. The potential of passive dosimeters based on microdialysis sampling for on-site, real-time monitoring of chemical contaminants in pore soil solution is thoroughly discussed and critically compared with active microsamplers. Recent...

  15. Synthesis of LaAlO3 by metal organic decomposition on SrTiO3 substrates

    Science.gov (United States)

    Ampuero, J. L.; Iliescu, I.; Boudard, M.; Jamaoui, A.; Rapenne, L.; Jimenez, C.; Roussel, H.

    2013-11-01

    LaAlO3 (LAO) films on SrTiO3 (STO) substrates have been produced by metal organic decomposition using La(C5H7O2)3 and Al(C5H7O2)3 as precursors dissolved in propionic acid. The process consists of growing thin layers through dip coating and subsequent annealing. After testing different cationic ratios of La and Al, it was determined that an optimal ratio leads to a single LAO phase film that grows epitaxially (cube on cube) on top of the STO. This was shown by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses. These analyses, as well as additional X-ray reflectivity analysis, also revealed that the LAO's thickness obtained in one dip ranges from 8 nm to 16 nm. Taking advantage of the epitaxial conditions, several layers can be stacked by successive dip coatings and annealing to form an epitaxial structure.

  16. Comparison of the columnar-thin-film and vacuum-metal-deposition techniques to develop sebaceous fingermarks on nonporous substrates.

    Science.gov (United States)

    Williams, Stephanie F; Pulsifer, Drew P; Shaler, Robert C; Ramotowski, Robert S; Brazelle, Shelly; Lakhtakia, Akhlesh

    2015-03-01

    Both the columnar-thin-film (CTF) and the vacuum-metal-deposition (VMD) techniques for visualizing sebaceous fingermarks require the deposition of a material thereon in a vacuum chamber. Despite that similarity, there are many differences between the two techniques. The film deposited with the CTF technique has a columnar morphology, but the film deposited with the VMD technique comprises discrete islands. A split-print methodology on a variety of fingermarked substrates was used to determine that the CTF technique is superior for developing fingermarks on clear sandwich bags and partial bloody fingermarks on stainless steel. Both techniques are similar in their ability to develop fingermarks on glass but the CTF technique yields higher contrast. The VMD technique is superior for developing fingermarks on white grocery bags and the smooth side of Gloss Finish Scotch Multitask(™) tape. Neither technique worked well for fingermarks on black garbage bags. © 2014 American Academy of Forensic Sciences.

  17. New Mechanistic Insight from Substrate- and Product-Bound Structures of the Metal-Dependent Dimethylsulfoniopropionate Lyase DddQ.

    Science.gov (United States)

    Brummett, Adam E; Dey, Mishtu

    2016-11-08

    The marine microbial catabolism of dimethylsulfoniopropionate (DMSP) by the lyase pathway liberates ∼300 million tons of dimethyl sulfide (DMS) per year, which plays a major role in the biogeochemical cycling of sulfur. Recent biochemical and structural studies of some DMSP lyases, including DddQ, reveal the importance of divalent transition metal ions in assisting DMSP cleavage. While DddQ is believed to be zinc-dependent primarily on the basis of structural studies, excess zinc inhibits the enzyme. We examine the importance of iron in regulating the DMSP β-elimination reaction catalyzed by DddQ as our as-isolated purple-colored enzyme possesses ∼0.5 Fe/subunit. The UV-visible spectrum exhibited a feature at 550 nm, consistent with a tyrosinate-Fe(III) ligand-to-metal charge transfer transition. Incubation of as-isolated DddQ with added iron increases the intensity of the 550 nm peak, whereas addition of dithionite causes a bleaching as Fe(III) is reduced. Both the Fe(III) oxidized and Fe(II) reduced species are active, with similar k cat values and 2-fold differences in their K m values for DMSP. The slow turnover of Fe(III)-bound DddQ allowed us to capture a substrate-bound form of the enzyme. Our DMSP-Fe(III)-DddQ structure reveals conformational changes associated with substrate binding and shows that DMSP is positioned optimally to bind iron and is in the proximity of Tyr 120 that acts as a Lewis base to initiate catalysis. The structures of Tris-, DMSP-, and acrylate-bound forms of Fe(III)-DddQ reported here illustrate various states of the enzyme along the reaction pathway. These results provide new insights into DMSP lyase catalysis and have broader significance for understanding the mechanism of oceanic DMS production.

  18. Metal-assisted exfoliation (MAE): green, roll-to-roll compatible method for transferring graphene to flexible substrates

    International Nuclear Information System (INIS)

    Zaretski, Aliaksandr V; Moetazedi, Herad; Kong, Casey; Sawyer, Eric J; Savagatrup, Suchol; Valle, Eduardo; O’Connor, Timothy F; Printz, Adam D; Lipomi, Darren J

    2015-01-01

    Graphene is expected to play a significant role in future technologies that span a range from consumer electronics, to devices for the conversion and storage of energy, to conformable biomedical devices for healthcare. To realize these applications, however, a low-cost method of synthesizing large areas of high-quality graphene is required. Currently, the only method to generate large-area single-layer graphene that is compatible with roll-to-roll manufacturing destroys approximately 300 kg of copper foil (thickness = 25 μm) for every 1 g of graphene produced. This paper describes a new environmentally benign and scalable process of transferring graphene to flexible substrates. The process is based on the preferential adhesion of certain thin metallic films to graphene; separation of the graphene from the catalytic copper foil is followed by lamination to a flexible target substrate in a process that is compatible with roll-to-roll manufacturing. The copper substrate is indefinitely reusable and the method is substantially greener than the current process that uses relatively large amounts of corrosive etchants to remove the copper. The sheet resistance of the graphene produced by this new process is unoptimized but should be comparable in principle to that produced by the standard method, given the defects observable by Raman spectroscopy and the presence of process-induced cracks. With further improvements, this green, inexpensive synthesis of single-layer graphene could enable applications in flexible, stretchable, and disposable electronics, low-profile and lightweight barrier materials, and in large-area displays and photovoltaic modules. (paper)

  19. Metal-assisted exfoliation (MAE): green, roll-to-roll compatible method for transferring graphene to flexible substrates

    Science.gov (United States)

    Zaretski, Aliaksandr V.; Moetazedi, Herad; Kong, Casey; Sawyer, Eric J.; Savagatrup, Suchol; Valle, Eduardo; O'Connor, Timothy F.; Printz, Adam D.; Lipomi, Darren J.

    2015-01-01

    Graphene is expected to play a significant role in future technologies that span a range from consumer electronics, to devices for the conversion and storage of energy, to conformable biomedical devices for healthcare. To realize these applications, however, a low-cost method of synthesizing large areas of high-quality graphene is required. Currently, the only method to generate large-area single-layer graphene that is compatible with roll-to-roll manufacturing destroys approximately 300 kg of copper foil (thickness = 25 μm) for every 1 g of graphene produced. This paper describes a new environmentally benign and scalable process of transferring graphene to flexible substrates. The process is based on the preferential adhesion of certain thin metallic films to graphene; separation of the graphene from the catalytic copper foil is followed by lamination to a flexible target substrate in a process that is compatible with roll-to-roll manufacturing. The copper substrate is indefinitely reusable and the method is substantially greener than the current process that uses relatively large amounts of corrosive etchants to remove the copper. The sheet resistance of the graphene produced by this new process is unoptimized but should be comparable in principle to that produced by the standard method, given the defects observable by Raman spectroscopy and the presence of process-induced cracks. With further improvements, this green, inexpensive synthesis of single-layer graphene could enable applications in flexible, stretchable, and disposable electronics, low-profile and lightweight barrier materials, and in large-area displays and photovoltaic modules.

  20. Investigation of structural and electrical properties on substrate material for high frequency metal-oxide-semiconductor (MOS) devices

    Science.gov (United States)

    Kumar, M.; Yang, Sung-Hyun; Janardhan Reddy, K.; JagadeeshChandra, S. V.

    2017-04-01

    Hafnium oxide (HfO2) thin films were grown on cleaned P-type Ge and Si substrates by using atomic layer deposition technique (ALD) with thickness of 8 nm. The composition analysis of as-deposited and annealed HfO2 films was characterized by XPS, further electrical measurements; we fabricated the metal-oxide-semiconductor (MOS) devices with Pt electrode. Post deposition annealing in O2 ambient at 500 °C for 30 min was carried out on both Ge and Si devices. Capacitance-voltage (C-V) and conductance-voltage (G-V) curves measured at 1 MHz. The Ge MOS devices showed improved interfacial and electrical properties, high dielectric constant (~19), smaller EOT value (0.7 nm), and smaller D it value as Si MOS devices. The C-V curves shown significantly high accumulation capacitance values from Ge devices, relatively when compare with the Si MOS devices before and after annealing. It could be due to the presence of very thin interfacial layer at HfO2/Ge stacks than HfO2/Si stacks conformed by the HRTEM images. Besides, from current-voltage (I-V) curves of the Ge devices exhibited similar leakage current as Si devices. Therefore, Ge might be a reliable substrate material for structural, electrical and high frequency applications.

  1. Design and production of a 2.5 kWe insulated metal substrate-based densely packed CPV assembly

    Science.gov (United States)

    Micheli, Leonardo; Sarmah, Nabin; Luo, Xichun; Reddy, K. S.; Mallick, Tapas K.

    2014-09-01

    The original design of a new 144-cell concentrating photovoltaic assembly is presented in this paper. It is conceived to work under 500 suns and to generate about 2.5 kWe. An insulated metal substrate was selected as baseplate, in order to get the best compromise between costs and thermal performances. It is based on a 2mm thick aluminum plate, which is in charge of removing the heat as quick as possible. The copper pattern and thickness has been designed accordingly to the IPC Generic Standard on Printed Board Design and to the restrictions of fit a reflective 125x primary optics and a 4x secondary refractive optics. The original outline of the conductive copper layer has been developed to minimize Joule losses by reducing the number of interconnections between the cells in series. Multijunction solar cells and Schottky bypass diodes have been soldered onto the board as surface mounted components. All the fabrication processes are described. This board represents a novelty for the innovative pattern of the conductive layer, which can be easily adapted to be coupled with different optics geometries and to allocate a different number of cells. The use of an IMS as baseplate will give an experimental contribution to the debate about the exploitability of this kind of substrates in CPV. This board is being characterized indoor and outdoor: the results will be used to improve the design and the reliability of the future receivers.

  2. Development and evolution of biaxial texture of rolled nickel tapes by ion beam bombardment for high Tc coated conductors

    International Nuclear Information System (INIS)

    Wang, S.S.; Wu, K.; Shi, K.; Liu, Q.; Han, Z.

    2004-01-01

    High quality YBa 2 Cu 3 O 7-x films on metallic substrates with high critical current densities well over 10 6 A/cm 2 can be prepared by the rolling assisted biaxially textured substrates (RABiTS) method. Nickel or its alloys have been used as biaxially textured substrates formed through a specific rolling and high temperature annealing procedures. In this paper, we report a newly developed process for developing biaxial texture in rolled Ni tape by argon ion beam bombardment. It is named the ion-beam structure modification (ISM) process. In the ISM processed Ni foils, X-ray diffraction ω scans showed the full width-half maximum (FWHM) value of the (2 0 0) peak was 5.7 deg. . And the electron back scattering diffraction (EBSP) analysis based on scanning electron microscopy showed good {1 0 0} cubic orientation and the mean grain size was determined as about 25 μm. The texture evolution of rolled Ni foils during ISM process is reported also. For ISM process, local temperature elevation and distribution arises from the ion bombardment, coupled with anisotropic incident ion penetration and propagation as a result of channeling effects in the metal lattice, are expected to play the major roles in the development of grain reorientation in the Ni foil. Due to the simplicity and efficiency of the ISM process, the technique shows a great promise for application in the industrial scale production of long-lengths of superconductor tapes

  3. Copper-vapor-assisted chemical vapor deposition for high-quality and metal-free single-layer graphene on amorphous SiO2 substrate.

    Science.gov (United States)

    Kim, Hyungki; Song, Intek; Park, Chibeom; Son, Minhyeok; Hong, Misun; Kim, Youngwook; Kim, Jun Sung; Shin, Hyun-Joon; Baik, Jaeyoon; Choi, Hee Cheul

    2013-08-27

    We report that high-quality single-layer graphene (SLG) has been successfully synthesized directly on various dielectric substrates including amorphous SiO2/Si by a Cu-vapor-assisted chemical vapor deposition (CVD) process. The Cu vapors produced by the sublimation of Cu foil that is suspended above target substrates without physical contact catalyze the pyrolysis of methane gas and assist nucleation of graphene on the substrates. Raman spectra and mapping images reveal that the graphene formed on a SiO2/Si substrate is almost defect-free and homogeneous single layer. The overall quality of graphene grown by Cu-vapor-assisted CVD is comparable to that of the graphene grown by regular metal-catalyzed CVD on a Cu foil. While Cu vapor induces the nucleation and growth of SLG on an amorphous substrate, the resulting SLG is confirmed to be Cu-free by synchrotron X-ray photoelectron spectroscopy. The SLG grown by Cu-vapor-assisted CVD is fabricated into field effect transistor devices without transfer steps that are generally required when SLG is grown by regular CVD process on metal catalyst substrates. This method has overcome two important hurdles previously present when the catalyst-free CVD process is used for the growth of SLG on fused quartz and hexagonal boron nitride substrates, that is, high degree of structural defects and limited size of resulting graphene, respectively.

  4. Fly ash based geopolymer thin coatings on metal substrates and its thermal evaluation.

    Science.gov (United States)

    Temuujin, Jadambaa; Minjigmaa, Amgalan; Rickard, William; Lee, Melissa; Williams, Iestyn; van Riessen, Arie

    2010-08-15

    Class F fly ash based Na-geopolymer formulations have been applied as fire resistant coatings on steel. The main variables for the coating formulations were Si: Al molar and water: cement weight ratios. We have determined that the adhesive strength of the coatings strongly depend on geopolymer composition. The ease with which geopolymer can be applied onto metal surfaces and the resultant thickness depend on the water content of the formulation. Adhesive strengths of greater than 3.5 MPa have been achieved on mild steel surfaces for compositions with Si:Al of 3.5. Microstructure evolution and thermal properties of the optimised coating formulations show that they have very promising fire resistant characteristics. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Interaction of cw CO2 laser radiation with plasma near-metallic substrate surface

    Science.gov (United States)

    Azharonok, V. V.; Astapchik, S. A.; Zabelin, Alexandre M.; Golubev, Vladimir S.; Golubev, V. S.; Grezev, A. N.; Filatov, Igor V.; Chubrik, N. I.; Shimanovich, V. D.

    2000-07-01

    Optical and spectroscopic methods were used in studying near-surface plasma that is formed under the effect CW CO2 laser of (2- 5)x106W/cm2 power density upon stainless steel in He and Ar shielding gases. The variation of plume spatial structure with time has been studied, the outflow of gas-vapor jets from the interaction area has been characterized. The spectra of plasma plume pulsations have been obtained for the frequency range Δf = 0-1 MHz. The temperature and electron concentration of plasma plume have been found under radiation effect upon the target of stainless steel. Consideration has been given to the most probable mechanisms of CW laser radiation-metal non-stationary interaction.

  6. Mid-infrared reflectance of silicone resin coating on metal substrates: Effect of polymeric binders' absorption

    Science.gov (United States)

    Ho, Wen-Dar; Ma, Chen-Chi M.

    1997-04-01

    This study examines the infrared reflectance of polymeric coatings of silicone resin, silicone modified alkyd resin, and alkyd resin on aluminum substrates. The Kubelka-Munk's two constants theory is applied to calculate the reflectance while considering the surface reflection. An integrating sphere, infrared spectroradiometer and blackbody source are utilized as the measurement systems. The extinction coefficients are determined and used to calculate the reflectances of coatings on aluminum. Coefficients in the mid-infrared region display the quantitative difference between the polymers' structure. Silicone content enhances the absorptance of the coating in the mid-IR region. The coefficients of miscible silicone resin/alkyd resin blends are determined as well. Comparing the measured and calculated reflectances reveals that the discrepancies in thinner coatings or at the IR transparent wavelength are higher and around 0.1. Such a discrepancy is owing to the polymers' non-scattering with absorption properties which affect the validity of the values involving internal reflectances considered in the model. The internal reflectance can be assigned a negligible value in the high absorption region and is also a variable depending on thickness and transparency.

  7. Molten-Metal Droplet Deposition on a Moving Substrate in Microgravity: Aiding the Development of Novel Technologies for Microelectronic Assembly

    Science.gov (United States)

    Megaridis, C. M.; Bayer, I. S.; Poulikakos, D.; Nayagam, V.

    2002-01-01

    Driven by advancements in microelectronics manufacturing, this research investigates the oblique (non-axisymmetric) impact of liquid-metal droplets on flat substrates. The problem of interest is relevant to the development of the novel technology of on-demand dispension (printing) of microscopic solder deposits for the surface mounting of microelectronic devices. The technology, known as solder jetting, features on-demand deposition of miniature solder droplets (30 to 120 microns in diameter) in very fine, very accurate patterns using techniques analogous to those developed for the ink-jet printing industry. Despite its promise, severe limitations exist currently with regards to the throughput rates of the technology; some of these limitations are largely due to the lack of the capability for reliable prediction of solder bump positioning and shapes, especially under ballistic deposition conditions where the droplet impact phenomena are inherently three-dimensional. The study consists of a theoretical and an experimental component. The theoretical work uses a finite element formulation to simulate numerically the non-axisymmetric (3-D) fluid mechanics and heat transfer phenomena of a liquid solder droplet impacting at an angle alpha on a flat substrate. The work focuses on the pre-solidification regime. The modeling of the most challenging fluid mechanics part of the process has been completed successfully. It is based upon the full laminar Navier-Stokes equations employing a Lagrangian frame of reference. Due to the large droplet deformation, the surface (skin) as well as the volumetric mesh have to be regenerated during the calculations in order to maintain the high accuracy of the numerical scheme. The pressure and velocity fields are then interpolated on the newly created mesh. The numerical predictions are being tested against experiments, for cases where wetting phenomena are not important. For the impact parameters used in the example shown (We = 2.38, Fr

  8. Thermo-chemical production of hydrogen from water by metal oxides fixed on ceramic substrates

    International Nuclear Information System (INIS)

    Roeb, M.; Monnerie, N.; Schmitz, M.; Sattler, C.; Konstandopoulos, A.G.; Agrafiotis, C.; Zaspalis, V.T.; Nalbandian, L.; Steele, A.; Stobbe, P.

    2006-01-01

    In the European project HYDROSOL a simple two-step thermo-chemical cycle process has been developed and investigated. It is based on metal oxide redox pair systems, which can split water molecules by abstracting oxygen atoms and reversibly incorporating them into their lattice. If concentrated solar radiation is used as the heat source one has a promising method in hand to produce hydrogen without any environmentally critical emissions. The basic idea is to combine a support capable of achieving high temperatures when heated by concentrated solar radiation, with a redox pair system suitable for water dissociation and at the same time for regeneration at these temperatures, so that complete operation of the whole process could be achieved by a single solar energy converter. The feasibility of the process has proven possible in a mini-plant scale using concentrated sunlight provided by the solar furnace in Cologne. Suitable redox materials as coatings and a dedicated receiver-reactor have been developed to produce hydrogen with significant conversions by repeating several subsequent water splitting and regeneration steps. In a design study a possible way of operating the process in commercial scale is demonstrated. (authors)

  9. Effect of Adhesive Type on the Shear Bond Strength of Metal Brackets to Two Ceramic Substrates

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Ahmad Akhoundi

    2014-04-01

    Full Text Available Increased number of adult patients requesting orthodontic treatment result in bonding bracket to ceramic restorations more than before. The aim of this study was to evaluate and compare the shear bond strength of orthodontic brackets bonded to two types of ceramic bases with conventional orthodontic bonding resin and a new nano-filled composite resin.Twenty four feldespathic porcelain and 24 lithium disilicate ceramic disks were fabricated. All of the samples were conditioned by sandblasting, hydrofluoric acid and silane. Maxillary incisor metal brackets were bonded to half of the disks in each group by conventional orthodontic bonding resin and the other half bonded with a nano-filled composite. The samples then were thermocycled for 2000 cycle between 5-55° C. Shear bond strength was measured and the mode of failure was examined. Randomly selected samples were also evaluated by SEM.The lowest bond strength value was found infeldespathic ceramic bonded by nano-filled composite (p<0.05. There was not any statistically significant difference between other groups regarding bond strength. The mode of failure in the all groups except group 1 was cohesive and porcelain damages were detected.Since less damages to feldspathic porcelain was observed when the nano-filled composite was used to bond brackets, the use of nano-filled composite resins can be suggested for bonding brackets to feldspathic porcelain restorations.

  10. Formation of Ultrathin, Continuous Metal-Organic Framework Membranes on Flexible Polymer Substrates.

    Science.gov (United States)

    Hou, Jingwei; Sutrisna, Putu D; Zhang, Yatao; Chen, Vicki

    2016-03-14

    Metal-organic framework (MOF) materials have an enormous potential in separation applications, but to realize their potential as semipermeable membranes they need to be assembled into thin continuous macroscopic films for fabrication into devices. By using a facile immersion technique, we prepared ultrathin, continuous zeolitic imidazolate framework (ZIF-8) membranes on titania-functionalized porous polymeric supports. The coherent ZIF-8 layer was surprisingly flexible and adhered well to the support, and the composite membrane could sustain bending and elongation. The membranes exhibited molecular sieving behavior, close to the theoretical permeability of ZIF-8, with hydrogen permeance up to 201×10(-7)  mol m(-2)  s(-1)  Pa(-1) and an ideal H2 /CO2 selectivity of 7:1. This approach offers significant opportunities to exploit the unique properties of MOFs in the fabrication of separation and sensing devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Interaction of Pd with α-Al2O3(0001): A case study of modeling the metal-oxide interface on complex substrates

    OpenAIRE

    Gomes, J. R. B.; Illas, Francesc; Cruz Hernández, Norge; Márquez Cruz, Antonio Marcial; Fernández Sanz, Javier

    2002-01-01

    The Pd/α-Al2O3(0001) interface at low Pd coverage has been studied by a variety of theoretical methods and models at this metal-oxide interface. All results are consistent and predict a noticeable interaction dominated by the metal polarization in response to the presence of the substrate. A significant contribution of the charge transfer from the transition metal to the surface is also observed. The periodic fully relaxed calculations show that the most favorable adsorption site for the inte...

  12. A New Sample Substrate for Imaging and Correlating Organic and Trace Metal Composition in Biological Cells and Tissues

    International Nuclear Information System (INIS)

    Miller, L.; Wang, Q.; Smith, R.; Zhong, H.; Elliott, D.; Warren, J.

    2007-01-01

    Many disease processes involve alterations in the chemical makeup of tissue. Synchrotron-based infrared (IR) and X-ray fluorescence (XRF) microscopes are becoming increasingly popular tools for imaging the organic and trace metal compositions of biological materials, respectively, without the need for extrinsic labels or stains. Fourier transform infrared microspectroscopy (FTIRM) provides chemical information on the organic components of a material at a diffraction-limited spatial resolution of 2-10 μm in the mid-infrared region. The synchrotron X-ray fluorescence (SXRF) microprobe is a complementary technique used to probe trace element content in the same systems with a similar spatial resolution. However to be most beneficial, it is important to combine the results from both imaging techniques on a single sample, which requires precise overlap of the IR and X-ray images. In this work, we have developed a sample substrate containing a gold grid pattern on its surface, which can be imaged with both the IR and X-ray microscopes. The substrate consists of a low trace element glass slide that has a gold grid patterned on its surface, where the major and minor parts of the grid contain 25 and 12 nm gold, respectively. This grid pattern can be imaged with the IR microscope because the reflectivity of gold differs as a function of thickness. The pattern can also be imaged with the SXRF microprobe because the Au fluorescence intensity changes with gold thickness. The tissue sample is placed on top of the patterned substrate. The grid pattern's IR reflectivity image and the gold SXRF image are used as fiducial markers for spatially overlapping the IR and SXRF images from the tissue. Results show that IR and X-ray images can be correlated precisely, with a spatial resolution of less than one pixel (i.e., 2-3 microns). The development of this new tool will be presented along with applications to paraffin-embedded metalloprotein crystals, Alzheimer's disease, and hair

  13. Texture and microstructure analysis of epitaxial oxide layers prepared on textured Ni-12wt%Cr tapes

    Energy Technology Data Exchange (ETDEWEB)

    Huehne, R; Kursumovic, A; Tomov, R I; Glowacki, B A [Department of Materials Science and IRC in Superconductivity, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Holzapfel, B [Institut fuer Festkoerper- und Werkstoffforschung, Helmholtzstrasse 20, 01069 Dresden (Germany); Evetts, J E [Department of Materials Science and IRC in Superconductivity, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    2003-05-07

    Oxide layers for the preparation of YBa{sub 2}Cu{sub 3}O{sub 7-x} coated conductors were grown on highly textured Ni-12wt%Cr tapes in pure oxygen using surface oxidation epitaxy at temperatures between 1000 deg. C and 1300 deg. C. Microstructural investigations revealed a layered oxide structure. The upper layer consists mainly of dense cube textured NiO. This is followed by a porous layer containing NiO and NiCr{sub 2}O{sub 4} particles. A detailed texture analysis showed a cube-on-cube relationship of the NiCr{sub 2}O{sub 4} spinel to the metal substrate. Untextured Cr{sub 2}O{sub 3} particles in a nickel matrix were found in a third layer arising from internal oxidation of the alloy. A high surface roughness and mechanical instability of the oxide were observed, depending on oxidation temperature and film thickness. However, mechanically stable oxide layers have been prepared using an additional annealing step in a protective atmosphere. Additionally, mechanical polishing or a second buffer layer, which grows with a higher smoothness, may be applied to reduce the surface roughness for coated conductor applications.

  14. Liberation of metal clads of waste printed circuit boards by removal of halogenated epoxy resin substrate using dimethylacetamide.

    Science.gov (United States)

    Verma, Himanshu Ranjan; Singh, Kamalesh K; Mankhand, Tilak Raj

    2017-02-01

    Present work reports the evaluation of dimethylacetamide (DMAc) as a solvent to dissolve the halogenated epoxy resin substrate (HERS) of waste printed circuit boards (WPCBs). Studies revealed that HERS dissolution attributes to the cracking and delamination of WPCB's layers. Variation of the parameters governing the dissolution elucidated that dissolution is directly dependent on temperature and WPCBs concentration in DMAc. The results also showed that increase in the WPCBs size drastically retards the rate of HERS dissolution. After delamination, the spent DMAc was regenerated, and the dissolved HERS was recovered as residue. The chemical structure of regenerated solution and recovered residue were found to be similar to pure DMAc and untreated HERS, respectively. Cyclic usage of regenerated DMAc revealed that 3-5% of DMAc is lost after each usage cycle while its effectiveness to dissolve the HERS remains equivalent to the pure DMAc. The dissolution of HERS ensures the liberation of copper cladded on the surface of WPCBs, and thus the proposed process avoids the requirement of highly energy intensive metal liberation processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

    Science.gov (United States)

    Latifi, Afrooz; Imani, Mohammad; Khorasani, Mohammad Taghi; Daliri Joupari, Morteza

    2014-11-01

    Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m-1), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer-metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

  16. Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

    KAUST Repository

    Semple, James

    2017-01-02

    Electronic memory cells are of critical importance in modern-day computing devices, including emerging technology sectors such as large-area printed electronics. One technology that has being receiving significant interest in recent years is resistive switching primarily due to its low dimensionality and nonvolatility. Here, we describe the development of resistive switching memory device arrays based on empty aluminum nanogap electrodes. By employing adhesion lithography, a low-temperature and large-area compatible nanogap fabrication technique, dense arrays of memory devices are demonstrated on both rigid and flexible plastic substrates. As-prepared devices exhibit nonvolatile memory operation with stable endurance, resistance ratios >10⁴ and retention times of several months. An intermittent analysis of the electrode microstructure reveals that controlled resistive switching is due to migration of metal from the electrodes into the nanogap under the application of an external electric field. This alternative form of resistive random access memory is promising for use in emerging sectors such as large-area electronics as well as in electronics for harsh environments, e.g., space, high/low temperature, magnetic influences, radiation, vibration, and pressure.

  17. Growth of InAs Quantum Dots on Germanium Substrate Using Metal Organic Chemical Vapor Deposition Technique

    Directory of Open Access Journals (Sweden)

    Tyagi Renu

    2009-01-01

    Full Text Available Abstract Self-assembled InAs quantum dots (QDs were grown on germanium substrates by metal organic chemical vapor deposition technique. Effects of growth temperature and InAs coverage on the size, density, and height of quantum dots were investigated. Growth temperature was varied from 400 to 450 °C and InAs coverage was varied between 1.40 and 2.35 monolayers (MLs. The surface morphology and structural characteristics of the quantum dots analyzed by atomic force microscope revealed that the density of the InAs quantum dots first increased and then decreased with the amount of InAs coverage; whereas density decreased with increase in growth temperature. It was observed that the size and height of InAs quantum dots increased with increase in both temperature and InAs coverage. The density of QDs was effectively controlled by growth temperature and InAs coverage on GaAs buffer layer.

  18. The growth of high density network of MOF nano-crystals across macroporous metal substrates - Solvothermal synthesis versus rapid thermal deposition

    Science.gov (United States)

    Maina, James W.; Gonzalo, Cristina Pozo; Merenda, Andrea; Kong, Lingxue; Schütz, Jürg A.; Dumée, Ludovic F.

    2018-01-01

    Fabrication of metal organic framework (MOF) films and membranes across macro-porous metal substrates is extremely challenging, due to the large pore sizes across the substrates, poor wettability, and the lack of sufficient reactive functional groups on the surface, which prevent high density nucleation of MOF crystals. Herein, macroporous stainless steel substrates (pore size 44 × 40 μm) are functionalized with amine functional groups, and the growth of ZIF-8 crystals investigated through both solvothermal synthesis and rapid thermal deposition (RTD), to assess the role of synthesis routes in the resultant membranes microstructure, and subsequently their performance. Although a high density of well interconnected MOF crystals was observed across the modified substrates following both techniques, RTD was found to be a much more efficient route, yielding high quality membranes under 1 h, as opposed to the 24 h required for solvothermal synthesis. The RTD membranes also exhibited high gas permeance, with He permeance of up to 2.954 ± 0.119 × 10-6 mol m-2 s-1 Pa-1, and Knudsen selectivities for He/N2, Ar/N2 and CO2/N2, suggesting the membranes were almost defect free. This work opens up route for efficient fabrication of MOF films and membranes across macro-porous metal supports, with potential application in electrically mediated separation applications.

  19. Origin of low sodium capacity in graphite and generally weak substrate binding of Na and Mg among alkali and alkaline earth metals.

    Science.gov (United States)

    Liu, Yuanyue; Merinov, Boris V; Goddard, William A

    2016-04-05

    It is well known that graphite has a low capacity for Na but a high capacity for other alkali metals. The growing interest in alternative cation batteries beyond Li makes it particularly important to elucidate the origin of this behavior, which is not well understood. In examining this question, we find a quite general phenomenon: among the alkali and alkaline earth metals, Na and Mg generally have the weakest chemical binding to a given substrate, compared with the other elements in the same column of the periodic table. We demonstrate this with quantum mechanics calculations for a wide range of substrate materials (not limited to C) covering a variety of structures and chemical compositions. The phenomenon arises from the competition between trends in the ionization energy and the ion-substrate coupling, down the columns of the periodic table. Consequently, the cathodic voltage for Na and Mg is expected to be lower than those for other metals in the same column. This generality provides a basis for analyzing the binding of alkali and alkaline earth metal atoms over a broad range of systems.

  20. Laser surface texturing of tool steel: textured surfaces quality evaluation

    Science.gov (United States)

    Šugár, Peter; Šugárová, Jana; Frnčík, Martin

    2016-05-01

    In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

  1. Production of stable superhydrophilic surfaces on 316L steel by simultaneous laser texturing and SiO2 deposition

    Science.gov (United States)

    Rajab, Fatema H.; Liu, Zhu; Li, Lin

    2018-01-01

    Superhydrophilic surfaces with liquid contact angles of less than 5 ° have attracted much interest in practical applications including self-cleaning, cell manipulation, adhesion enhancement, anti-fogging, fluid flow control and evaporative cooling. Standard laser metal texturing method often result in unstable wetting characteristics, i.e. changing from super hydrophilic to hydrophobic in a few days or weeks. In this paper, a simple one step method is reported for fabricating a stable superhydrophilic metallic surface that lasted for at least 6 months. Here, 316L stainless steel substrates were textured using a nanosecond laser with in-situ SiO2 deposition. Morphology and chemistry of laser-textured surfaces were characterised using SEM, XRD, XPS and an optical 3D profiler. Static wettability analysis was carried out over a period of 6 months after the laser treatment. The effect of surface roughness on wettability was also studied. Results showed that the wettability of the textured surfaces could be controlled by changing the scanning speed of laser beam and number of passes. The main reason for the realisation of the stable superhydrophilic surface is the combination of the melted glass particles mainly Si and O with that of stainless steel in the micro-textured patterns. This study presents a useful method

  2. Oxidations of Organic and Inorganic Substrates by Superoxo-, hydroperoxo-, and oxo-compounds of the transition metals

    International Nuclear Information System (INIS)

    Michael John Vasbinder

    2006-01-01

    values of the Hammett reaction constant PN were -1.0(1) for 4-nitro-2-methylpyridine-N-oxide and -2.6(4) for 4-methylpyridine-N-oxide as substrates. The negative value confirms pyridine is acting as a nucleophile. Nucleophiles other than pyridine derivatives were also tested. In the end, it was found that the most effective nucleophiles were the pyridine-N-oxides themselves, meaning that a second equivalent of substrate serves as the most efficient promoter of this oxygen-atom transfer reaction. This relative nucleophilicity of pyridines and pyridine-N-oxides is similar to what is observed in other OAT reactions generating high-valent metal-oxo species

  3. The effect of surface treatment on the surface texture and contact angle of electrochemically deposited hydroxyapatite coating and on its interaction with bone-forming cells.

    Science.gov (United States)

    Eliaz, Noam; Shmueli, Sharon; Shur, Irena; Benayahu, Dafna; Aronov, Daniel; Rosenman, Gil

    2009-10-01

    This work demonstrates the effects of both surface preparation and surface post-treatment by exposure to electron beam on the surface texture, contact angle and the interaction with bone-forming cells of electrochemically deposited hydroxyapatite (HAp) coating. Both the surface texture and the contact angle of the ground titanium substrate changed as a result of either heat treatment following soaking in NaOH solution or soaking in H(2)O(2) solution. Consequently, the shape of the current transients during potentiostatic deposition of HAp changed, and the resulting coatings exhibited different surface textures and contact angles. The developed interfacial area ratio Sdr and the core fluid retention index Sci were found more reliable than the mean roughness R(a) and the root-mean-square roughness Z(rms) in correlating the adhesion of the coating to the metal substrate and the cellular response with surface texture. The NaOH pretreatment provided the highest surface area and induced the highest cell attachment, even though the H(2)O(2) treatment provided the highest hydrophilicity to the metal substrate. Electrodeposition at pH 6 was found preferable compared to electrodeposition at pH 4.2. The ability to modify the cellular response by exposure to unique electron-beam surface treatment was demonstrated. The very high hydrophilicity of the as-deposited HAp coating enhanced its bioactivity.

  4. Guidelines for bottom-up approach of nanocarbon film formation from pentacene using heated tungsten on quartz substrate without metal catalyst

    Science.gov (United States)

    Heya, Akira; Matsuo, Naoto

    2018-04-01

    The guidelines for a bottom-up approach of nanographene formation from pentacene using heated tungsten were investigated using a novel method called hot mesh deposition (HMD). In this method, a heated W mesh was set between a pentacene source and a quartz substrate. Pentacene molecules were decomposed by the heated W mesh. The generated pentacene-based decomposed precursors were then deposited on the quartz substrate. The pentacene dimer (peripentacene) was obtained from pentacene by HMD using two heated catalysts. As expected from the calculation with the density functional theory in the literature, it was confirmed that the pentacene dimer can be formed by a reaction between pentacene and 6,13-dihydropentacene. This technique can be applied to the formation of novel nanographene on various substrates without metal catalysts.

  5. Mathematical modelling of dropwise condensation on textured ...

    Indian Academy of Sciences (India)

    The minimum drop radius is insensitive to surface texturing and does not provide controllability at larger length and timescales. A closer examination of droplet distribution over the substrate reveals that small drops are locations of high heat transfer rates, which diminishes with increasing drop radius. The largest drop ...

  6. Initial-rate kinetics of human NMN-adenylyltransferases: substrate and metal ion specificity, inhibition by products and multisubstrate analogues, and isozyme contributions to NAD+ biosynthesis.

    Science.gov (United States)

    Sorci, Leonardo; Cimadamore, Flavio; Scotti, Stefania; Petrelli, Riccardo; Cappellacci, Loredana; Franchetti, Palmarisa; Orsomando, Giuseppe; Magni, Giulio

    2007-04-24

    Initial-rate and product inhibition studies revealed distinctive ordered ternary complex kinetic mechanisms, substrate specificities, and metal ion preferences for the three isozymes of human nicotinamide mononucleotide adenylyl-transferase (NMNAT, EC 2.7.7.1). ATP binds before NMN with nuclear isozyme NMNAT1 and Golgi apparatus NMNAT2, but the opposite order is observed with the mitochondrial isozyme NMNAT3. Only the latter utilizes ITP efficiently in place of ATP, and while NMNH conversion to NADH by NMNAT1 and NMNAT3 occurs at similar rates, conversion by NMNAT2 is much slower. These isozymes can also be discriminated by their action on tiazofurin monophosphate (TrMP), a metabolite of the antineoplastic prodrug tiazofurin. Our finding that TrMP is only a substrate with NMNAT1 and NMNAT3 reveals for the first time an organelle selectivity in the metabolism of this important drug. In search of additional ways to discriminate these isozymes, we synthesized and tested the P1-(nicotinamide/nicotinate-riboside-5')-Pn-(adenosine-5') dinucleotides Np3AD, Np4AD, and Nap4AD. In addition to being highly effective inhibitors, these multisubstrate geometric inhibitors gave inhibition patterns that are consistent with the aforementioned isozyme differences in substrate binding order. Distinctive differences in their substrate specificity and metal ion selectivity also permitted us to quantify individual isozyme contributions to NAD+ formation in human cell extracts.

  7. Investigation of the effects of misfit strain on barium strontium titanate thin films deposited on base metal substrates by a modified phenomenological model

    Science.gov (United States)

    Dong, Hanting; Li, Hongfang; Chen, Jianguo; Jin, Dengren; Cheng, Jinrong

    2017-10-01

    The Landau-Devonshire phenomenological model, which has been utilized to investigate epitaxial barium strontium titanate (BST) thin films, was modified to investigate the effects of misfit strain on the dielectric properties of polycrystalline BST thin films deposited on base metal substrates. The modification considers the relaxation of lattice misfit stress resulting from the formation of in-plane misfit dislocations. The modified lattice misfit strain was calculated by referring to the ferroelectric critical grain size. Moreover, the misfit strain and dielectric properties of BST thin films with different structures and substrates were investigated by the models. It was found that the measured dielectric constant and tunability of BST thin films on different metal substrates overall agreed with the computed data. In addition, the good agreement was also observed for sandwich-like structural BST thin films deposited on LNO buffered stainless steel plates. Our results indicated that the modified L-D models might be utilized to predict dielectric properties of polycrystalline BST thin films for varied substrates and multilayer structures.

  8. Electrohydrodynamic spinning of random-textured silver webs for electrodes embedded in flexible organic solar cells

    Science.gov (United States)

    Yoon, Dai Geon; Chin, Byung Doo; Bail, Robert

    2017-03-01

    A convenient process for fabricating a transparent conducting electrode on a flexible substrate is essential for numerous low-cost optoelectronic devices, including organic solar cells (OSCs), touch sensors, and free-form lighting applications. Solution-processed metal-nanowire arrays are attractive due to their low sheet resistance and optical clarity. However, the limited conductance at wire junctions and the rough surface topology still need improvement. Here, we present a facile process of electrohydrodynamic spinning using a silver (Ag) - polymer composite paste with high viscosity. Unlike the metal-nanofiber web formed by conventional electrospinning, a relatively thick, but still invisible-to-naked eye, Ag-web random pattern was formed on a glass substrate. The process parameters such as the nozzle diameter, voltage, flow rate, standoff height, and nozzle-scanning speed, were systematically engineered. The formed random texture Ag webs were embedded in a flexible substrate by in-situ photo-polymerization, release from the glass substrate, and post-annealing. OSCs with a donor-acceptor polymeric heterojunction photoactive layer were prepared on the Ag-web-embedded flexible films with various Ag-web densities. The short-circuit current and the power conversion efficiency of an OSC with a Ag-web-embedded electrode were not as high as those of the control sample with an indium-tin-oxide electrode. However, the Ag-web textures embedded in the OSC served well as electrodes when bent (6-mm radius), showing a power conversion efficiency of 2.06% (2.72% for the flat OSC), and the electrical stability of the Ag-web-textured patterns was maintained for up to 1,000 cycles of bending.

  9. Oxidations of Organic and Inorganic Substrates by Superoxo-, hydroperoxo-, and oxo-compounds of the transition metals.

    Energy Technology Data Exchange (ETDEWEB)

    Vasbinder, Michael John [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    fitting the observed rate constants to the Hammett correlation. It was found that the values of the Hammett reaction constant PN were -1.0(1) for 4-nitro-2-methylpyridine-N-oxide and -2.6(4) for 4-methylpyridine-N-oxide as substrates. The negative value confirms pyridine is acting as a nucleophile. Nucleophiles other than pyridine derivatives were also tested. In the end, it was found that the most effective nucleophiles were the pyridine-N-oxides themselves, meaning that a second equivalent of substrate serves as the most efficient promoter of this oxygen-atom transfer reaction. This relative nucleophilicity of pyridines and pyridine-N-oxides is similar to what is observed in other OAT reactions generating high-valent metal-oxo species.

  10. Occupancy of the Zinc-binding Site by Transition Metals Decreases the Substrate Affinity of the Human Dopamine Transporter by an Allosteric Mechanism.

    Science.gov (United States)

    Li, Yang; Mayer, Felix P; Hasenhuetl, Peter S; Burtscher, Verena; Schicker, Klaus; Sitte, Harald H; Freissmuth, Michael; Sandtner, Walter

    2017-03-10

    The human dopamine transporter (DAT) has a tetrahedral Zn 2+ -binding site. Zn 2+ -binding sites are also recognized by other first-row transition metals. Excessive accumulation of manganese or of copper can lead to parkinsonism because of dopamine deficiency. Accordingly, we examined the effect of Mn 2+ , Co 2+ , Ni 2+ , and Cu 2+ on transport-associated currents through DAT and DAT-H193K, a mutant with a disrupted Zn 2+ -binding site. All transition metals except Mn 2+ modulated the transport cycle of wild-type DAT with affinities in the low micromolar range. In this concentration range, they were devoid of any action on DAT-H193K. The active transition metals reduced the affinity of DAT for dopamine. The affinity shift was most pronounced for Cu 2+ , followed by Ni 2+ and Zn 2+ (= Co 2+ ). The extent of the affinity shift and the reciprocal effect of substrate on metal affinity accounted for the different modes of action: Ni 2+ and Cu 2+ uniformly stimulated and inhibited, respectively, the substrate-induced steady-state currents through DAT. In contrast, Zn 2+ elicited biphasic effects on transport, i.e. stimulation at 1 μm and inhibition at 10 μm A kinetic model that posited preferential binding of transition metal ions to the outward-facing apo state of DAT and a reciprocal interaction of dopamine and transition metals recapitulated all experimental findings. Allosteric activation of DAT via the Zn 2+ -binding site may be of interest to restore transport in loss-of-function mutants. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Occupancy of the Zinc-binding Site by Transition Metals Decreases the Substrate Affinity of the Human Dopamine Transporter by an Allosteric Mechanism*

    Science.gov (United States)

    Li, Yang; Mayer, Felix P.; Hasenhuetl, Peter S.; Burtscher, Verena; Schicker, Klaus; Sitte, Harald H.; Freissmuth, Michael; Sandtner, Walter

    2017-01-01

    The human dopamine transporter (DAT) has a tetrahedral Zn2+-binding site. Zn2+-binding sites are also recognized by other first-row transition metals. Excessive accumulation of manganese or of copper can lead to parkinsonism because of dopamine deficiency. Accordingly, we examined the effect of Mn2+, Co2+, Ni2+, and Cu2+ on transport-associated currents through DAT and DAT-H193K, a mutant with a disrupted Zn2+-binding site. All transition metals except Mn2+ modulated the transport cycle of wild-type DAT with affinities in the low micromolar range. In this concentration range, they were devoid of any action on DAT-H193K. The active transition metals reduced the affinity of DAT for dopamine. The affinity shift was most pronounced for Cu2+, followed by Ni2+ and Zn2+ (= Co2+). The extent of the affinity shift and the reciprocal effect of substrate on metal affinity accounted for the different modes of action: Ni2+ and Cu2+ uniformly stimulated and inhibited, respectively, the substrate-induced steady-state currents through DAT. In contrast, Zn2+ elicited biphasic effects on transport, i.e. stimulation at 1 μm and inhibition at 10 μm. A kinetic model that posited preferential binding of transition metal ions to the outward-facing apo state of DAT and a reciprocal interaction of dopamine and transition metals recapitulated all experimental findings. Allosteric activation of DAT via the Zn2+-binding site may be of interest to restore transport in loss-of-function mutants. PMID:28096460

  12. Effect of thermal annealing on the redistribution of alkali metals in Cu(In,Ga)Se2 solar cells on glass substrate

    Science.gov (United States)

    Kamikawa, Yukiko; Nishinaga, Jiro; Ishizuka, Shogo; Tayagaki, Takeshi; Guthrey, Harvey; Shibata, Hajime; Matsubara, Koji; Niki, Shigeru

    2018-03-01

    The precise control of alkali-metal concentrations in Cu(In,Ga)Se2 (CIGS) solar cells via post deposition treatment (PDT) has recently attracted attention. When PDT is performed at an elevated temperature, an accompanying annealing effect is expected. Here, we investigate how thermal annealing affects the redistribution of alkali metals in CIGS solar cells on glass substrates and the properties of the solar cells. In addition, we investigate the origin of non-homogeneous alkali-metal depth profiles that are typical of CIGS grown using a three-stage process. In particular, we use secondary-ion mass spectrometry measurements of the ion concentration as a function of distance from the CIGS surface to investigate the impact of thermal annealing on the distribution of alkali metals (Na, Ka, and Rb) and constituent elements (Ga and In) in the CIGS absorbers. We find that the depth profiles of the alkali metals strongly reflect the density of sites that tend to accommodate alkali metals, i.e., vacancies. Annealing at elevated temperature caused a redistribution of the alkali metals. The thermal-diffusion kinetics of alkali metals depends strongly on the species involved. We introduced low flux potassium fluoride (KF) to study a side effect of KF-PDT, i.e., Na removal from CIGS, separately from its predominant effects such as surface modification. When sufficient amounts of Na are supplied from the soda lime glass via annealing at an elevated temperature, the negative effect was not apparent. Conversely, when the Na supply was not sufficient, it caused a deterioration of the photovoltaic properties.

  13. Effect of Thermal Annealing on the Redistribution of Alkali Metals in Cu(In,Ga)Se2 Solar Cells on Glass Substrate

    Energy Technology Data Exchange (ETDEWEB)

    Guthrey, Harvey L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kamikawa, Yukiko [National Institute of Advanced Industrial Science and Technology (AIST); Nishinaga, Jiro [National Institute of Advanced Industrial Science and Technology (AIST); Ishizuka, Shogo [National Institute of Advanced Industrial Science and Technology (AIST); Tayagaki, Takeshi [National Institute of Advanced Industrial Science and Technology (AIST); Shibata, Hajime [National Institute of Advanced Industrial Science and Technology (AIST); Matsubara, Koji [National Institute of Advanced Industrial Science and Technology (AIST); Niki, Shigeru [National Institute of Advanced Industrial Science and Technology (AIST)

    2018-03-02

    The precise control of alkali-metal concentrations in Cu(In,Ga)Se2 (CIGS) solar cells via post deposition treatment (PDT) has recently attracted attention. When PDT is performed at an elevated temperature, an accompanying annealing effect is expected. Here, we investigate how thermal annealing affects the redistribution of alkali metals in CIGS solar cells on glass substrates and the properties of the solar cells. In addition, we investigate the origin of non-homogeneous alkali-metal depth profiles that are typical of CIGS grown using a three-stage process. In particular, we use secondary-ion mass spectrometry measurements of the ion concentration as a function of distance from the CIGS surface to investigate the impact of thermal annealing on the distribution of alkali metals (Na, Ka, and Rb) and constituent elements (Ga and In) in the CIGS absorbers. We find that the depth profiles of the alkali metals strongly reflect the density of sites that tend to accommodate alkali metals, i.e., vacancies. Annealing at elevated temperature caused a redistribution of the alkali metals. The thermal-diffusion kinetics of alkali metals depends strongly on the species involved. We introduced low flux potassium fluoride (KF) to study a side effect of KF-PDT, i.e., Na removal from CIGS, separately from its predominant effects such as surface modification. When sufficient amounts of Na are supplied from the soda lime glass via annealing at an elevated temperature, the negative effect was not apparent. Conversely, when the Na supply was not sufficient, it caused a deterioration of the photovoltaic properties.

  14. All Metal Organic Deposited High-Tc Superconducting Transition Edge Bolometer on Yttria-Stabilized Zirconia Substrate

    DEFF Research Database (Denmark)

    Mohajeri, Roya; Opata, Yuri Aparecido; Wulff, Anders Christian

    2016-01-01

    We report on the results of a YBa2Cu3O7−x (YBCO) superconductive transition edge bolometer (TEB) fabricated on a Ce0.9La0.1O2−7 (CLO) buffered single crystalline yttria-stabilized zirconia (YSZ) substrate. Metal organic deposition was used for the fabrication of both the YBCO thin film as well as...... (STO). This increase is assumed to be a result of the lower thermal conductivity and lower specific heat capacity of YSZ compared to STO substrate....... of voltage amplitude and phase was analysed and measured through four-probe technique in a liquid nitrogen cooling system. An increase in voltage amplitude response was observed for the fabricated YBCO/CLO/YSZ bolometer compared to previously reported TEBs with similarly deposited YBCO thin film on a SrTiO3...

  15. N-polar GaN/AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistor formed on sapphire substrate with minimal step bunching

    Science.gov (United States)

    Prasertsuk, Kiattiwut; Tanikawa, Tomoyuki; Kimura, Takeshi; Kuboya, Shigeyuki; Suemitsu, Tetsuya; Matsuoka, Takashi

    2018-01-01

    The metal-insulator-semiconductor (MIS) gate N-polar GaN/AlGaN/GaN high-electron-mobility transistor (HEMT) on a (0001) sapphire substrate, which can be expected to operate with lower on-resistance and more easily work on the pinch-off operation than an N-polar AlGaN/GaN HEMT, was fabricated. For suppressing the step bunching and hillocks peculiar in the N-polar growth, a sapphire substrate with an off-cut angle as small as 0.8° was introduced and an N-polar GaN/AlGaN/GaN HEMT without the step bunching was firstly obtained by optimizing the growth conditions. The previously reported anisotropy of transconductance related to the step was eliminated. The pinch-off operation was also realized. These results indicate that this device is promising.

  16. Measurement of Color Texture

    NARCIS (Netherlands)

    Hoang, M.A.; Geusebroek, J.M.; Deprettere, E.F.; Belloum, A.; Heijnsdijk, J.W.J.; van der Stappen, F.

    2002-01-01

    In computer vision, measurement of image properties such as color or texture is essential. However, existing methods for measuring color and texture in combination are not well-defined neither from a measurement theoretical basis nor from a physical point of view. We propose a solid framework for

  17. Textured perovskite cells

    NARCIS (Netherlands)

    Deelen, J. van; Tezsevin, Y.; Barink, M.

    2017-01-01

    Most research of texturization of solar cells has been devoted to Si based cells. For perovskites, it was assumed that texturization would not have much of an impact because of the relatively low refractive indexes lead to relatively low reflection as compared to the Si based cells. However, our

  18. Mimicking human texture classification

    NARCIS (Netherlands)

    Rogowitz, B.E.; van Rikxoort, Eva M.; van den Broek, Egon; Pappas, T.N.; Schouten, Theo E.; Daly, S.J.

    2005-01-01

    In an attempt to mimic human (colorful) texture classification by a clustering algorithm three lines of research have been encountered, in which as test set 180 texture images (both their color and gray-scale equivalent) were drawn from the OuTex and VisTex databases. First, a k-means algorithm was

  19. Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystals at imperfect metals.

    Science.gov (United States)

    Kaiser, V; Comtet, J; Niguès, A; Siria, A; Coasne, B; Bocquet, L

    2017-07-01

    The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon a previous approach [M. A. Vorotyntsev and A. A. Kornyshev, Zh. Eksp. Teor. Fiz., 1980, 78(3), 1008-1019] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas-Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allows for an estimation of the interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. The counter-intuitive outcome is that electronic screening, as characterized by a molecular Thomas-Fermi length l TF , profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement.

  20. Electrostatic interactions between ions near Thomas-Fermi substrates and the surface energy of ionic crystal at imperfect metals

    Science.gov (United States)

    Kaiser, V.; Comtet, J.; Niguès, A.; Siria, A.; Coasne, B.; Bocquet, L.

    2017-01-01

    The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas-Fermi description. In this paper we build upon the approach by [Kornyshev et al. Zh. Eksp. Teor. Fiz., 78(3):1008–1019, 1980] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas-Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas-Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allow for an estimate of interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. A counterintuitive outcome is that electronic screening, as characterized by a molecular Thomas-Fermi length ℓTF, profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement. PMID:28436506

  1. Pilot-scale passive bioreactors for the treatment of acid mine drainage: efficiency of mushroom compost vs. mixed substrates for metal removal.

    Science.gov (United States)

    Song, Hocheol; Yim, Gil-Jae; Ji, Sang-Woo; Neculita, Carmen Mihaela; Hwang, Taewoon

    2012-11-30

    Pilot-scale field-testing of passive bioreactors was performed to evaluate the efficiency of a mixture of four substrates (cow manure compost, mushroom compost, sawdust, and rice straw) relative to mushroom compost alone, and of the effect of the Fe/Mn ratio, during the treatment of acid mine drainage (AMD) over a 174-day period. Three 141 L columns, filled with either mushroom compost or the four substrate mixture (in duplicate), were set-up and fed with AMD from a closed mine site, in South Korea, using a 4-day hydraulic retention time. In the former bioreactor, effluent deterioration was observed over 1-2 months, despite the good efficiency predicted by the physicochemical characterization of mushroom compost. Steady state effluent quality was then noted for around 100 days before worsening in AMD source water occurred in response to seasonal variations in precipitation. Such changes in AMD quality resulted in performance deterioration in all reactors followed by a slow recovery toward the end of testing. Both substrates (mushroom compost and mixtures) gave satisfactory performance in neutralizing pH (6.1-7.8). Moreover, the system was able to consistently reduce sulfate from day 49, after the initial leaching out from organic substrates. Metal removal efficiencies were on the order of Al (∼100%) > Fe (68-92%) > Mn (49-61%). Overall, the mixed substrates showed comparable performance to mushroom compost, while yielding better effluent quality upon start-up. The results also indicated mushroom compost could release significant amounts of Mn and sulfate during bioreactor operation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. PLZT capacitor on glass substrate

    Science.gov (United States)

    Fairchild, M. Ray; Taylor, Ralph S.; Berlin, Carl W.; Wong, Celine W. K.; Ma, Beihai; Balachandran, Uthamalingam

    2016-01-05

    A lead-lanthanum-zirconium-titanate (PLZT) capacitor on a substrate formed of glass. The first metallization layer is deposited on a top side of the substrate to form a first electrode. The dielectric layer of PLZT is deposited over the first metallization layer. The second metallization layer deposited over the dielectric layer to form a second electrode. The glass substrate is advantageous as glass is compatible with an annealing process used to form the capacitor.

  3. In-situ wafer bowing measurements of GaN grown on Si (111) substrate by reflectivity mapping in metal organic chemical vapor deposition system

    International Nuclear Information System (INIS)

    Yang Yi-Bin; Liu Ming-Gang; Chen Wei-Jie; Han Xiao-Biao; Chen Jie; Lin Xiu-Qi; Lin Jia-Li; Luo Hui; Liao Qiang; Zang Wen-Jie; Chen Yin-Song; Qiu Yun-Ling; Wu Zhi-Sheng; Liu Yang; Zhang Bai-Jun

    2015-01-01

    In this work, the wafer bowing during growth can be in-situ measured by a reflectivity mapping method in the 3×2″ Thomas Swan close coupled showerhead metal organic chemical vapor deposition (MOCVD) system. The reflectivity mapping method is usually used to measure the film thickness and growth rate. The wafer bowing caused by stresses (tensile and compressive) during the epitaxial growth leads to a temperature variation at different positions on the wafer, and the lower growth temperature leads to a faster growth rate and vice versa. Therefore, the wafer bowing can be measured by analyzing the discrepancy of growth rates at different positions on the wafer. Furthermore, the wafer bowings were confirmed by the ex-situ wafer bowing measurement. High-resistivity and low-resistivity Si substrates were used for epitaxial growth. In comparison with low-resistivity Si substrate, GaN grown on high-resistivity substrate shows a larger wafer bowing caused by the highly compressive stress introduced by compositionally graded AlGaN buffer layer. This transition of wafer bowing can be clearly in-situ measured by using the reflectivity mapping method. (paper)

  4. Metal Decoration Effects on the Gas-Sensing Properties of 2D Hybrid-Structures on Flexible Substrates

    Directory of Open Access Journals (Sweden)

    Byungjin Cho

    2015-09-01

    Full Text Available We have investigated the effects of metal decoration on the gas-sensing properties of a device with two-dimensional (2D molybdenum disulfide (MoS2 flake channels and graphene electrodes. The 2D hybrid-structure device sensitively detected NO2 gas molecules (>1.2 ppm as well as NH3 (>10 ppm. Metal nanoparticles (NPs could tune the electronic properties of the 2D graphene/MoS2 device, increasing sensitivity to a specific gas molecule. For instance, palladium NPs accumulate hole carriers of graphene/MoS2, electronically sensitizing NH3 gas molecules. Contrarily, aluminum NPs deplete hole carriers, enhancing NO2 sensitivity. The synergistic combination of metal NPs and 2D hybrid layers could be also applied to a flexible gas sensor. There was no serious degradation in the sensing performance of metal-decorated MoS2 flexible devices before/after 5000 bending cycles. Thus, highly sensitive and endurable gas sensor could be achieved through the metal-decorated 2D hybrid-structure, offering a useful route to wearable electronic sensing platforms.

  5. Metal Decoration Effects on the Gas-Sensing Properties of 2D Hybrid-Structures on Flexible Substrates.

    Science.gov (United States)

    Cho, Byungjin; Yoon, Jongwon; Lim, Sung Kwan; Kim, Ah Ra; Choi, Sun-Young; Kim, Dong-Ho; Lee, Kyu Hwan; Lee, Byoung Hun; Ko, Heung Cho; Hahm, Myung Gwan

    2015-09-25

    We have investigated the effects of metal decoration on the gas-sensing properties of a device with two-dimensional (2D) molybdenum disulfide (MoS₂) flake channels and graphene electrodes. The 2D hybrid-structure device sensitively detected NO₂ gas molecules (>1.2 ppm) as well as NH₃ (>10 ppm). Metal nanoparticles (NPs) could tune the electronic properties of the 2D graphene/MoS₂ device, increasing sensitivity to a specific gas molecule. For instance, palladium NPs accumulate hole carriers of graphene/MoS₂, electronically sensitizing NH₃ gas molecules. Contrarily, aluminum NPs deplete hole carriers, enhancing NO₂ sensitivity. The synergistic combination of metal NPs and 2D hybrid layers could be also applied to a flexible gas sensor. There was no serious degradation in the sensing performance of metal-decorated MoS₂ flexible devices before/after 5000 bending cycles. Thus, highly sensitive and endurable gas sensor could be achieved through the metal-decorated 2D hybrid-structure, offering a useful route to wearable electronic sensing platforms.

  6. Zn-bis-glutathionate is the best co-substrate of the monomeric phytochelatin synthase from the photosynthetic heavy metal-hyperaccumulator Euglena gracilis.

    Science.gov (United States)

    García-García, Jorge D; Girard, Lourdes; Hernández, Georgina; Saavedra, Emma; Pardo, Juan P; Rodríguez-Zavala, José S; Encalada, Rusely; Reyes-Prieto, Adrián; Mendoza-Cózatl, David G; Moreno-Sánchez, Rafael

    2014-03-01

    The phytochelatin synthase from photosynthetic Euglena gracilis (EgPCS) was analyzed at the transcriptional, kinetic, functional, and phylogenetic levels. Recombinant EgPCS was a monomeric enzyme able to synthesize, in the presence of Zn(2+) or Cd(2+), phytochelatin2-phytochelatin4 (PC2-PC4) using GSH or S-methyl-GS (S-methyl-glutathione), but not γ-glutamylcysteine or PC2 as a substrate. Kinetic analysis of EgPCS firmly established a two-substrate reaction mechanism for PC2 synthesis with Km values of 14-22 mM for GSH and 1.6-2.5 μM for metal-bis-glutathionate (Me-GS2). EgPCS showed the highest Vmax and catalytic efficiency with Zn-(GS)2, and was inactivated by peroxides. The EgPCS N-terminal domain showed high similarity to that of other PCSases, in which the typical catalytic core (Cys-70, His-179 and Asp-197) was identified. In contrast, the C-terminal domain showed no similarity to other PCSases. An EgPCS mutant comprising only the N-terminal 235 amino acid residues was inactive, suggesting that the C-terminal domain is essential for activity/stability. EgPCS transcription in Euglena cells was not modified by Cd(2+), whereas its heterologous expression in ycf-1 yeast cells provided resistance to Cd(2+) stress. Phylogenetic analysis of the N-terminal domain showed that EgPCS is distant from plants and other photosynthetic organisms, suggesting that it evolved independently. Although EgPCS showed typical features of PCSases (constitutive expression; conserved N-terminal domain; kinetic mechanism), it also exhibited distinct characteristics such as preference for Zn-(GS)2 over Cd-(GS)2 as a co-substrate, a monomeric structure, and ability to solely synthesize short-chain PCs, which may be involved in conferring enhanced heavy-metal resistance.

  7. Textures and ores structure

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    In this part of book author made conclusion that structural-texture particularities reflect the physical and chemical conditions, velocity of minerals crystallization, further tectonic situation, presence appearances of meta-somatic substitution, second decomposition and minerals leaching

  8. Quantitative texture analysis of electrodeposited line patterns

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A.J.

    2005-01-01

    Free-standing line patterns of Cu and Ni were manufactured by electrochemical deposition into lithographically prepared patterns. Electrodeposition was carried out on top of a highly oriented Au-layer physically vapor deposited on glass. Quantitative texture analysis carried out by means of x......-ray diffraction for both the substrate layer and the electrodeposits yielded experimental evidence for epitaxy between Cu and Au. An orientation relation between film and substrate was discussed with respect to various concepts of epitaxy. While the conventional mode of epitaxy fails for the Cu...

  9. Comment on "Nanosecond laser textured superhydrophobic metallic surfaces and their chemical sensing applications" by Duong V. Ta, Andrew Dunn, Thomas J. Wasley, Robert W. Kay, Jonathan Stringer, Patrick J. Smith, Colm Connaughton, Jonathan D. Shephard (Appl. Surf. Sci. 357 (2015) 248-254)

    Science.gov (United States)

    Boinovich, L. B.; Emelyanenko, A. M.; Emelyanenko, K. A.; Domantovsky, A. G.; Shiryaev, A. A.

    2016-08-01

    Nowadays the problem of design of durable ecologically friendly superhydrophobic surfaces is of great importance for science and technology. A recent paper in Applied Surface Science reports the method of fabricating the superhydrophobic metallic surfaces by infrared nanosecond laser surface texturing without using hydrophobic agents. Since this method of surface texturing can be considered as one of the most suitable for various industrial applications, the nature of superhydrophobic state of surfaces produced by laser texturing in the abovementioned paper deserves to be analyzed in detail. Authors of the commented paper attributed the change in wettability to the partial deoxidation of CuO into Cu2O on the surface during storage in atmosphere. However, such interpretation of the results contradicts to the basic notions in the theory of wetting and to more accurate and detailed data. In our Comment we discuss these contradictions point by point.

  10. Chiral-Selective Formation of 1D Polymers Based on Ullmann-Type Coupling : The Role of the Metallic Substrate

    NARCIS (Netherlands)

    Pham, Tuan Anh; Tran, Van Bay; Nguyen, Manh-Thuong; Stöhr, Meike

    2017-01-01

    The chiral-selective formation of 1D polymers from a prochiral molecule, namely, 6,12-dibromochrysene in dependence of the type of metal surface is demonstrated by a combined scanning tunneling microscopy and density functional theory study. Deposition of the chosen molecule on Au(111) held at room

  11. Toxic effects of heavy metals in three worm species exposed in artificially contaminated soil substrates and contaminated field soils

    NARCIS (Netherlands)

    Posthuma L; Notenboom J; ECO

    1996-01-01

    The toxicity of chemicals is often determined in standardised laboratory experiments. OECD artificial soil (artisoil) is often used to determine chemical toxicity for soil organisms. This report presents exposure and effect assessments of metals for three worm species (Eisenia andrei, Enchytraeus

  12. Texture and deformation mechanism of yttrium

    International Nuclear Information System (INIS)

    Adamesku, R.A.; Grebenkin, S.V.; Stepanenko, A.V.

    1992-01-01

    X-ray pole figure analysis was applied to study texture and deformation mechanism in pure and commercial polycrystalline yttrium on cold working. It was found that in cast yttrium the texture manifected itself weakly enough both for pure and commercial metal. Analysis of the data obtained made it possible to assert that cold deformation of pure yttrium in the initial stage occurred mainly by slip the role of which decreased at strains higher than 36%. The texture of heavily deformed commercial yttrium contained two components, these were an 'ideal' basic orientation and an axial one with the angle of inclination about 20 deg. Twinning mechanism was revealed to be also possible in commercial yttrium

  13. Phosphorous gettering in acidic textured multicrystalline solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Montesdeoca-Santana, A. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez 2, 38206 La Laguna, S/C de Tenerife (Spain); Fraunhofer Institut fuer Solare Energiesysteme ISE, Laboratory and Servicecenter Gelsenkirchen, Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Jimenez-Rodriguez, E.; Diaz-Herrera, B.; Hernandez-Rodriguez, C. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez 2, 38206 La Laguna, S/C de Tenerife (Spain); Gonzalez-Diaz, B. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez 2, 38206 La Laguna, S/C de Tenerife (Spain); Departamento de Energia Fotovoltaica, Instituto Tecnologico y de Energias Renovables. Poligono Industrial de Granadilla s/n, 38600 San Isidro-Granadilla de Abona, S/C de Tenerife (Spain); Rinio, M.; Borchert, D. [Fraunhofer Institut fuer Solare Energiesysteme ISE, Laboratory and Servicecenter Gelsenkirchen, Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Guerrero-Lemus, R. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez 2, 38206 La Laguna, S/C de Tenerife (Spain); Fundacion de Estudios de Economia Aplicada, Catedra Focus-Abengoa, Jorge Juan 46, 28001 Madrid (Spain)

    2011-03-15

    The influence of phosphorus gettering is studied in this work applied to an acidic textured multicrystalline silicon substrate. The texturization was achieved with an HF/HNO{sub 3} solution leading to nanostructures on the silicon surface. It has been demonstrated in previous works that this textured surface decreases the reflectance on the solar cell and increases the surface area improving the photon collection and enhancing the short circuit current. The present study investigates the effect on the minority carrier lifetime of the phosphorous diffusion when it is carried out on this textured surface. The lifetime is measured by means microwave photoconductance decay and quasi steady state phototoconductance devices. The diffused textured wafers are used to fabricate solar cells and their electrical parameters are analyzed. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Design of experiment evaluation of sputtered thin film platinum surface metallization on alumina substrate for implantable conductive structures.

    Science.gov (United States)

    Kiele, P; Cvancara, P; Mueller, M; Stieglitz, T

    2017-07-01

    Reliability and reproducibility of implants and their fabrication are highly depending on the assembly and packaging procedures. Individual fabrication skills like soldering introduce inaccuracies and should be avoided as much as possible. Screen printing is often utilized for the metallization of ceramics. Using platinum/gold (Pt/Au) paste liquidus diffusion leads to a low adhesion strength of the Pt/Au pads after soldering. As an alternative, sputtering of thin film surface metallization was investigated. However, this alternative comes with a huge amount of different layer and parameter setups. In order to keep the amount of experiments and data acquisition in a reasonable magnitude, the Design of Experiment (DoE) evaluation displays a powerful tool. We found an optimal layer setup that maximizes the adhesion strength of the layer, while simultaneously minimizing the sheet resistance and removing the dependency of soldering time.

  15. Characteristics of ion spectrum in a low energy nitrogen operated plasma focus: application to the metallic substrates thermal treatment

    International Nuclear Information System (INIS)

    Kelly, H.; Lepone, A.; Marquez, A.

    1998-01-01

    Full text: This work presents the nitrogen ion spectrum characteristics in a Plasma Focus device, determined using a Thomson spectrometer and a Faraday cup, operated in the secondary electron collective mode. It is also discussed the thermal treatment and the re coating induce by ions incident on a metallic surface (AISI 304 steel) placed in front of the coaxial gun, when the device is operated with a Ti implant at the end of the central electrode

  16. Effect of variable soil texture, metal saturation of soil organic matter (SOM) and tree species composition on spatial distribution of SOM in forest soils in Poland.

    Science.gov (United States)

    Gruba, Piotr; Socha, Jarosław; Błońska, Ewa; Lasota, Jarosław

    2015-07-15

    In this study we investigated the effect of fine (ϕsoils, site moisture, metal (Al and Fe) of soil organic matter (SOM) and forest species composition on the spatial distribution of carbon (C) pools in forest soils at the landscape scale. We established 275 plots in regular 200×200m grid in a forested area of 14.4km(2). Fieldwork included soil sampling of the organic horizon, mineral topsoil and subsoil down to 40cm deep. We analysed the vertical and horizontal distribution of soil organic carbon (SOC) stocks, as well as the quantity of physically separated fractions including the free light (fLF), occluded light (oLF) and mineral associated fractions (MAF) in the mineral topsoil (A, AE) horizons. Distribution of C in soils was predominantly affected by the variation in the FF content. In soils richer in the FF more SOC was accumulated in mineral horizons and less in the organic horizons. Accumulation of SOC in mineral soil was also positively affected by the degree of saturation of SOM with Al and Fe. The increasing share of beech influenced the distribution of C stock in soil profiles by reducing the depth of O horizon and increasing C stored in mineral soil. The content of FF was positively correlated with the content of C in MAF and fLF fractions. The content of oLF and MAF fractions was also positively influenced by a higher degree of metal saturation, particularly Al. Our results confirmed that Al plays an important role in the stabilization of SOM inside aggregates (CoLF) and as in CMAF fractions. We also found a significant, positive effect of beech on the CfLF and fir on the CoLF content. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. DNA Modified with Metal Nanoparticles: Preparation and Characterization of Ordered Metal-DNA Nanostructures in a Solution and on a Substrate

    Directory of Open Access Journals (Sweden)

    Nina Kasyanenko

    2016-01-01

    Full Text Available DNA interaction with silver and aluminum nanoparticles in a solution has been investigated with the AFM, SEM, dynamic light scattering, viscometry, and spectral methods. The comparison of DNA interaction with nanoparticles synthesized by the reduction of Ag+ ions and with nanoparticles obtained by the electric discharge plasma method was done. DNA metallization in a solution and on n-silicon surface with metal nanoparticles or by the reduction of silver ions after their binding to DNA was executed and studied. It was shown that DNA strands with regular location of silver or aluminum nanoparticles can be prepared. The conditions for the formation of silver nanoparticles and silver nanoclusters on DNA were analyzed.

  18. Computer Texture Mapping for Laser Texturing of Injection Mold

    Directory of Open Access Journals (Sweden)

    Yongquan Zhou

    2014-04-01

    Full Text Available Laser texturing is a relatively new multiprocess technique that has been used for machining 3D curved surfaces; it is more flexible and efficient to create decorative texture on 3D curved surfaces of injection molds so as to improve the surface quality and achieve cosmetic surface of molded plastic parts. In this paper, a novel method of laser texturing 3D curved surface based on 3-axis galvanometer scanning unit has been presented to prevent the texturing of injection mold surface from much distortion which is often caused by traditional texturing processes. The novel method has been based on the computer texture mapping technology which has been developed and presented. The developed texture mapping algorithm includes surface triangulation, notations, distortion measurement, control, and numerical method. An interface of computer texture mapping has been built to implement the algorithm of texture mapping approach to controlled distortion rate of 3D texture math model from 2D original texture applied to curvature surface. Through a case study of laser texturing of a high curvature surface of injection mold of a mice top case, it shows that the novel method of laser texturing meets the quality standard of laser texturing of injection mold.

  19. Ion-beam texturing of uniaxially textured Ni films

    International Nuclear Information System (INIS)

    Park, S.J.; Norton, D.P.; Selvamanickam, Venkat

    2005-01-01

    The formation of biaxial texture in uniaxially textured Ni thin films via Ar-ion irradiation is reported. The ion-beam irradiation was not simultaneous with deposition. Instead, the ion beam irradiates the uniaxially textured film surface with no impinging deposition flux, which differs from conventional ion-beam-assisted deposition. The uniaxial texture is established via a nonion beam process, with the in-plane texture imposed on the uniaxial film via ion beam bombardment. Within this sequential ion beam texturing method, grain alignment is driven by selective etching and grain overgrowth

  20. Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation

    Science.gov (United States)

    Liu, Jinxuan; Shekhah, Osama; Stammer, Xia; Arslan, Hasan K.; Liu, Bo; Schüpbach, Björn; Terfort, Andreas; Wöll, Christof

    2012-01-01

    The liquid phase epitaxy (LPE) of the metal-organic framework (MOF) HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs) on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA), 4’-carboxyterphenyl-4-methanethiol (TPMTA) and 9-carboxy-10-(mercaptomethyl)triptycene (CMMT). The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100) direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111) direction.

  1. Deposition of metal-organic frameworks by liquid-phase epitaxy: The influence of substrate functional group density on film orientation

    KAUST Repository

    Liu, J.

    2012-09-05

    The liquid phase epitaxy (LPE) of the metal-organic framework (MOF) HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs) on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA), 4\\'-carboxyterphenyl-4-methanethiol (TPMTA) and 9-carboxy-10-(mercaptomethyl)triptycene (CMMT). The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100) direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111) direction.

  2. Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation

    Directory of Open Access Journals (Sweden)

    Christof Wöll

    2012-09-01

    Full Text Available The liquid phase epitaxy (LPE of the metal-organic framework (MOF HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA, 4’-carboxyterphenyl-4-methanethiol (TPMTA and 9-carboxy-10-(mercaptomethyltriptycene (CMMT. The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100 direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111 direction.

  3. Precise Placement of Metallic Nanowires on a Substrate by Localized Electric Fields and Inter-Nanowire Electrostatic Interaction

    Directory of Open Access Journals (Sweden)

    U Hyeok Choi

    2017-10-01

    Full Text Available Placing nanowires at the predetermined locations on a substrate represents one of the significant hurdles to be tackled for realization of heterogeneous nanowire systems. Here, we demonstrate spatially-controlled assembly of a single nanowire at the photolithographically recessed region at the electrode gap with high integration yield (~90%. Two popular routes, such as protruding electrode tips and recessed wells, for spatially-controlled nanowire alignment, are compared to investigate long-range dielectrophoretic nanowire attraction and short-range nanowire-nanowire electrostatic interaction for determining the final alignment of attracted nanowires. Furthermore, the post-assembly process has been developed and tested to make a robust electrical contact to the assembled nanowires, which removes any misaligned ones and connects the nanowires to the underlying electrodes of circuit.

  4. A Molecular Dynamics Study of the Epitaxial Growth of Metallic Nanoclusters Softly Deposited on Substrates with Very Different Lattice Parameter

    International Nuclear Information System (INIS)

    Jimenez-Saez, J C; Perez-MartIn, A M C; Jimenez-RodrIguez, J J

    2007-01-01

    The soft deposition of Cu and Au clusters on Au(001) and Cu(001) surfaces respectively is studied by constant-temperature molecular-dynamics simulations. The initial shape of the nanoclusters is icosahedral or truncated octahedral (Wulff type). Their number of atoms ranges between 12 and 1289 atoms. Bombardment energy is of the order of a few meV/atom. The atomic interactions are mimicked by a many-body potential based on the tightbinding model. The effect of the temperature as activation to get the complete epitaxy is analysed. We have found that Cu clusters manage to align their {002} planes with the substrate by increasing the temperature. However, there is not epitaxial growth in any case since the lattice becomes bcc or important stacking faults are generated. For Au clusters, the alignment of these planes is practically independent of the temperature

  5. Shaping drops with textured surfaces

    Science.gov (United States)

    Ehlinger, Quentin; Biance, Anne-Laure; Ybert, Christophe

    2017-11-01

    When a drop impacts a substrate, it can behave differently depending on the nature of the surface and of the liquid (spreading, bouncing, resting, splashing ...). Understanding these behaviors is crucial to predict the drop morphology during and after impact. Whereas surface wettability has extensively been studied, the effect of surface roughness remains hardly explored. In this work, we consider the impact of a drop in a pure non-wetting situation by using superheated substrates i.e. in the Leidenfrost regime. The surface texture consists of a well-controlled microscopic defect shaped with photolithography on a smooth silicon wafer. Different regimes are observed, depending on the distance between the defect and the impact point and the defect size. Comparing the lamella thickness versus the defect height proves relevant as the transition criteria between regimes. Others characteristics of the drop behavior (direction of satellite droplet ejection, lamella rupture) are also well captured by inertial/capillary models. Drop impacts on multiple defects are also investigated and drop shape well predicted considering the interactions between the local flow and the defects.

  6. The pH-sensitive Pd nanoparticles as ink for ink-jet printing technology and electroless Cu metallic patterns on indium-doped tin oxide substrate

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Chun-Chieh; Lin, Yi [Medical Device Section, Medical Devices and Opto-Electronics Equipment Department, Metal Industries Research and Development Centre, Kaohsiung 802, Taiwan (China); Liu, Tsai-Yun [Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan (China); Nian, Yan-Yu [Graduate School of Defense Science, Chung Cheng Institute of Technology, National Defense University, 335 Taiwan (China); Wang, Min-Wen, E-mail: mwwang@cc.kuas.edu.tw [Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan (China); Ger, Ming-Der, E-mail: mingderger@gmail.com [Department of Chemical and Materials Engineering, Chung Cheng Institute of Technology, National Defense University, 335 Taiwan (China)

    2013-06-01

    In this work, a method to fabricate copper pattern on an indium-doped tin oxide (ITO) glass substrate is described. This method involves ink-jet printing of a pH-sensitive chitosan-g-polyvinyl acetate/Pd nanoparticle (CTS-g-PVAc-Pd) based ink on an untreated ITO plate to create the catalytic sites, onto which copper is subsequently deposited by an electroless plating method. To prepare the CTS-g-PVAc-Pd nanoparticles, a pH-sensitive chitosan-g-polyvinyl acetate (CTS-g-PVAc) copolymer is utilized to self-reduce Pd nanoparticles. The pH-sensitive CTS chains function as stabilizing agent for noble metal nanoparticles in acidic ink solution. On the other hand, CTS-g-PVAc copolymers convert to hydrophilic CTS-g-poly(vinyl alcohol) via alkali hydrolysis during the electroless copper plating. Therefore, the copper film with dramatically enhanced adhesion is formed on the surface of ITO glass without special pretreatment step before electroless deposition of copper film. Our results show that this process yields copper line with width down to 60 μm and ITO plated with the copper coating has good electrical conductivity, with an electrical resistivity of about 5.4 μΩ cm. - Highlights: • Chitosan-g-polyvinyl acetate copolymer provides reducing environment for Pd nanoparticles. • pH-sensitive Pd nanoparticles as ink for ink-jet printing. • Patterning Pd catalyst for the electroless deposition of copper patterns. • Method to fabricate copper patterns on In-doped tin oxide substrates. • Ink-jet printing can be directly and easily applied to fabricate metal patterns.

  7. SU-8-Induced Strong Bonding of Polymer Ligands to Flexible Substrates via in Situ Cross-Linked Reaction for Improved Surface Metallization and Fast Fabrication of High-Quality Flexible Circuits.

    Science.gov (United States)

    Hu, Mingjun; Guo, Qiuquan; Zhang, Tengyuan; Zhou, Shaolin; Yang, Jun

    2016-02-01

    On account of in situ cross-linked reaction of epoxy SU-8 with poly(4-vinylpyridine) (P4VP) and its strong reactive bonding ability with different pretreated substrates, we developed a simple universal one-step solution-based coating method for fast surface modification of various objects. Through this method, a layer of P4VP molecules with controllable thickness can be tethered tightly onto substrates with the assistance of SU-8. P4VP molecules possess a lot of pyridine ligands to immobilize transitional metal ions that can behave as the catalyst of electroless copper plating for surface metallization while functioning as the adhesion-promoting layer between the substrate and deposited metal. Attributed to interpenetrated entanglement of P4VP molecules and as-deposited metal, ultrathick (>7 μm) strongly adhesive high-quality copper layer can be formed on flexible substrates without any delamination. Then through laser printer to print toner mask, a variety of designed circuits can be easily fabricated on modified flexible PET substrate.

  8. In-situ wafer bowing measurements of GaN grown on Si (111) substrate by reflectivity mapping in metal organic chemical vapor deposition system

    Science.gov (United States)

    Yang, Yi-Bin; Liu, Ming-Gang; Chen, Wei-Jie; Han, Xiao-Biao; Chen, Jie; Lin, Xiu-Qi; Lin, Jia-Li; Luo, Hui; Liao, Qiang; Zang, Wen-Jie; Chen, Yin-Song; Qiu, Yun-Ling; Wu, Zhi-Sheng; Liu, Yang; Zhang, Bai-Jun

    2015-09-01

    In this work, the wafer bowing during growth can be in-situ measured by a reflectivity mapping method in the 3×2″ Thomas Swan close coupled showerhead metal organic chemical vapor deposition (MOCVD) system. The reflectivity mapping method is usually used to measure the film thickness and growth rate. The wafer bowing caused by stresses (tensile and compressive) during the epitaxial growth leads to a temperature variation at different positions on the wafer, and the lower growth temperature leads to a faster growth rate and vice versa. Therefore, the wafer bowing can be measured by analyzing the discrepancy of growth rates at different positions on the wafer. Furthermore, the wafer bowings were confirmed by the ex-situ wafer bowing measurement. High-resistivity and low-resistivity Si substrates were used for epitaxial growth. In comparison with low-resistivity Si substrate, GaN grown on high-resistivity substrate shows a larger wafer bowing caused by the highly compressive stress introduced by compositionally graded AlGaN buffer layer. This transition of wafer bowing can be clearly in-situ measured by using the reflectivity mapping method. Project supported by the National Natural Science Foundation of China (Grant Nos. 61274039 and 51177175), the National Basic Research Program of China (Grant No. 2011CB301903), the Ph.D. Programs Foundation of Ministry of Education of China (Grant No. 20110171110021), the International Science and Technology Collaboration Program of China (Grant No. 2012DFG52260), the International Science and Technology Collaboration Program of Guangdong Province, China (Grant No. 2013B051000041), the Science and Technology Plan of Guangdong Province, China (Grant No. 2013B010401013), the National High Technology Research and Development Program of China (Grant No. 2014AA032606), and the Opened Fund of the State Key Laboratory on Integrated Optoelectronics, China (Grant No. IOSKL2014KF17).

  9. Wetting transitions on textured hydrophilic surfaces.

    Science.gov (United States)

    Ishino, C; Okumura, K

    2008-04-01

    We consider the quasi-static energy of a drop on a textured hydrophilic surface, with taking the contact angle hysteresis (CAH) into account. We demonstrate how energy varies as the contact state changes from the Cassie state (in which air is trapped at the drop bottom) to the Wenzel state (in which liquid fills the texture at the drop bottom) assuming that the latter state nucleates from the center of the drop bottom. When the textured substrate is hydrophilic enough to allow spontaneous penetration of liquid film of the texture thickness, the present theory asserts that the drop develops into an experimentally observed state in which a drop looks like an egg fried without flipped over (sunny-side up) with a well-defined radius of "the egg yolk." Otherwise, the final contact state of the drop becomes like a Wenzel state, but with the contact circle smaller than the original Wenzel state due to the CAH. We provide simple analytical estimations for the yolk radius of the "sunny-side-up" state and for the final radius of the contact circle of the pseudo-Wenzel state.

  10. Numerical study of melted particles crush metallic substrates and the interaction between particles and a plasma beam in the thermal projection process

    International Nuclear Information System (INIS)

    Kriba, Ilhem; Djebaili, A.

    2009-01-01

    Plasma spray processes have been widely used to produce high performance coatings of a wide range of materials (metallic, non-metallic, and ceramics), offering protection from, e.g. wear, extreme temperature, chemical attack and environmental corrosion. To obtain good quality coatings, spray parameters must be carefully selected. Due to the large variety in process parameters, it is difficult to optimize the process for each specific coating and substrate combinations. Furthermore modelling the spray process allows a better understanding of the process sequences during thermal spraying. The simulation of coating formation to estimate the process parameters is an important tool to develop new coating structures with defined properties. In this work, the process of plasma sprayed coating has been analyzed by numerical simulation. Commercial code is used to predict the plasma jet characteristics, plasma-particle interaction, and coating formation. Using this model we can obtain coating microstructure and characteristics which form a foundation for further improvement of an advanced ceramic coating build up model

  11. Numerical Study Of Melted Particles Crush Metallic Substrates And The Interaction Between Particles And A Plasma Beam In The Thermal Projection Process

    International Nuclear Information System (INIS)

    Kriba, Ilhem; Djebaili, A.

    2008-01-01

    Plasma spray processes have been widely used to produce high performance coatings of a wide range of Materials (metallic, non-metallic, ceramics), offering protection from, eg. wear, extreme temperature, chemical attack and environmental corrosion. To obtain good quality coatings, spray parameters must be carefully selected. Due to the large variety in process parameters, it is difficult to optimize the process for each specific coating and substrate combinations. Furthermore modelling the spray process allows a better understanding of the process sequences during thermal spraying. Good agreement of the virtual spraying process with the real coating formation is achieved by modelling the particular process steps. The simulation of coating formation to estimate the process parameters is an important tool to develop new coating structures with defined properties. In this work, the process of plasma sprayed coating has been analyzed by numerical simulation. Commercial code is used to predict the plasma jet characteristics, plasma--particle interaction, and coating formation. Using this model we can obtain coating microstructure and characteristics which form a foundation for further improvement of an advanced ceramic coating build up model.

  12. The preparation and characterization of nearly hysteresis-free metal-nitride-silicon capacitors on both p- and n-type silicon substrates

    Science.gov (United States)

    Lau, W. S.

    1992-01-01

    The hysteresis in metal-nitride-silicon (MNS) capacitors can be reduced to nearly zero by using nitrogen-rich silicon nitride as the gate dielectric and treating the silicon substrate by an ammonia plasma before dielectric deposition. However, the ammonia plasma treatment step also causes an increase in interface state density, especially in the middle of the silicon band gap. Without the ammonia plasma treatment, the virgin flat-band voltage V*FB is always negative. With the ammonia plasma treatment, V*FB can be shifted from a negative value to zero for MNS capacitors on n-type silicon, whereas V*FB will be shifted from a negative value to a more negative value for MNS capacitors on p-type silicon. These effects can be explained by postulating that the interface states generated by the ammonia plasma treatment step are amphoteric defects similar to Pb centers at the oxide/silicon interface in metal-oxide-silicon capacitors.

  13. Numerical study of melted particles crush metallic substrates and the interaction between particles and a plasma beam in the thermal projection process

    Energy Technology Data Exchange (ETDEWEB)

    Kriba, Ilhem [Plasma Laboratory, Faculty of Sciences, Department of Physics, University of Ouargla, Ouargla (Algeria)], E-mail: ilhem_kriba@yahoo.fr; Djebaili, A. [Laboratory of Chemistry and Environment Chemistry L.C.C.E, University of Batna (Algeria)

    2009-03-01

    Plasma spray processes have been widely used to produce high performance coatings of a wide range of materials (metallic, non-metallic, and ceramics), offering protection from, e.g. wear, extreme temperature, chemical attack and environmental corrosion. To obtain good quality coatings, spray parameters must be carefully selected. Due to the large variety in process parameters, it is difficult to optimize the process for each specific coating and substrate combinations. Furthermore modelling the spray process allows a better understanding of the process sequences during thermal spraying. The simulation of coating formation to estimate the process parameters is an important tool to develop new coating structures with defined properties. In this work, the process of plasma sprayed coating has been analyzed by numerical simulation. Commercial code is used to predict the plasma jet characteristics, plasma-particle interaction, and coating formation. Using this model we can obtain coating microstructure and characteristics which form a foundation for further improvement of an advanced ceramic coating build up model.

  14. Epitaxial growth of textured YBa2Cu3O7-δ films on silver

    International Nuclear Information System (INIS)

    Liu Dan-Min; Liu Wei-Peng; Suo Hong-Li; Zhou Mei-Ling

    2005-01-01

    YBa 2 Cu 3 O 7-δ (YBCO) films were deposited on (100), (110) and (111) oriented silver single crystals and {100} left angle 100 right angle, {110} left angle 211 right angle, {110} left angle 100 right angle +{110} left angle 011 right angle {110} left angle 011 right angle and {012} left angle 100 right angle textured Ag substrates using pulsed laser deposition. The relationship between the epitaxial growth YBCO film and silver substrate has been determined. It is shown that among polycrystalline Ag substrates, {110} left angle 011 right angle textured tape is suitable for the deposition of YBCO thin films having strong texture. (orig.)

  15. Dielectric properties of thin C r2O3 films grown on elemental and oxide metallic substrates

    Science.gov (United States)

    Mahmood, Ather; Street, Michael; Echtenkamp, Will; Kwan, Chun Pui; Bird, Jonathan P.; Binek, Christian

    2018-04-01

    In an attempt to optimize leakage characteristics of α-C r2O3 thin films, its dielectric properties were investigated at local and macroscopic scale. The films were grown on Pd(111), Pt(111), and V2O3 (0001), supported on A l2O3 substrate. The local conductivity was measured by conductive atomic force microscopy mapping of C r2O3 surfaces, which revealed the nature of defects that formed conducting paths with the bottom Pd or Pt layer. A strong correlation was found between these electrical defects and the grain boundaries revealed in the corresponding topographic scans. In comparison, the C r2O3 film on V2O3 exhibited no leakage paths at similar tip bias value. Electrical resistance measurements through e-beam patterned top electrodes confirmed the resistivity mismatch between the films grown on different electrodes. The x-ray analysis attributes this difference to the twin free C r2O3 growth on V2O3 seeding.

  16. Influence of Substrate on Crystal Orientation of Large-Grained Si Thin Films Formed by Metal-Induced Crystallization

    Directory of Open Access Journals (Sweden)

    Kaoru Toko

    2015-01-01

    Full Text Available Producing large-grained polycrystalline Si (poly-Si film on glass substrates coated with conducting layers is essential for fabricating Si thin-film solar cells with high efficiency and low cost. We investigated how the choice of conducting underlayer affected the poly-Si layer formed on it by low-temperature (500°C Al-induced crystallization (AIC. The crystal orientation of the resulting poly-Si layer strongly depended on the underlayer material: (100 was preferred for Al-doped-ZnO (AZO and indium-tin-oxide (ITO; (111 was preferred for TiN. This result suggests Si heterogeneously nucleated on the underlayer. The average grain size of the poly-Si layer reached nearly 20 µm for the AZO and ITO samples and no less than 60 µm for the TiN sample. Thus, properly electing the underlayer material is essential in AIC and allows large-grained Si films to be formed at low temperatures with a set crystal orientation. These highly oriented Si layers with large grains appear promising for use as seed layers for Si light-absorption layers as well as for advanced functional materials.

  17. Texture analysis of

    NARCIS (Netherlands)

    Lubsch, A.; Timmermans, K.

    2017-01-01

    Texture analysis is a method to test the physical properties of a material by tension and compression. The growing interest in commercialisation of seaweeds for human food has stimulated research into the physical properties of seaweed tissue. These are important parameters for the survival of

  18. Texture affects color emotion

    NARCIS (Netherlands)

    Lucassen, M.P.; Gevers, T.; Gijsenij, A.

    2011-01-01

    Several studies have recorded color emotions in subjects viewing uniform color (UC) samples. We conduct an experiment to measure and model how these color emotions change when texture is added to the color samples. Using a computer monitor, our subjects arrange samples along four scales: warm-cool,

  19. Texture & Textiles, Together

    Science.gov (United States)

    Guhin, Paula

    2011-01-01

    Creating a painting with texture is easy, although using heavy gel medium or modeling paste may be pricey ways to go about it. High school artists generally like making collages and mixed-media. In this article, the author suggests ways to capitalize on that interest with inexpensive fabric in a painting project.

  20. Chameleons: Reptilian Texture

    Science.gov (United States)

    Petersen, Hugh

    2009-01-01

    This article presents an art project inspired by a drawing of a chameleon the author saw in an art-supply catalog. Chameleons prove to be a good subject to highlight shape, color and texture with eigth-graders. In this project, middle- and high-school students draw a chameleon, learn how to use shapes to add to their chameleon drawing, learn how…

  1. Strings, texture, and inflation

    International Nuclear Information System (INIS)

    Hodges, H.M.; Primack, J.R.

    1991-01-01

    We examine mechanisms, several of which are proposed here, to generate structure formation, or to just add large-scale features, through either gauged or global cosmic strings or global texture, within the framework of inflation. We first explore the possibility that strings or texture form if there is no coupling between the topological theory and the inflaton or spacetime curvature, via (1) quantum creation, and (2) a sufficiently high reheat temperature. In addition, we examine the prospects for the inflaton field itself to generate strings or texture. Then, models with the string/texture field coupled to the curvature, and an equivalent model with coupling to the inflaton field, are considered in detail. The requirement that inflationary density fluctuations are not so large as to conflict with observations leads to a number of constraints on model parameters. We find that strings of relevance for structure formation can form in the absence of coupling to the inflaton or curvature through the process of quantum creation, but only if the strings are strongly type I, or if they are global strings. If formed after reheating, naturalness suggests that gauged cosmic strings correspond to a type-I superconductor. Similarly, gauged strings formed during inflation via conformal coupling ξ=1/6 to the spacetime curvature (in a model suggested by Yokoyama in order to evade the millisecond pulsar constraint on cosmic strings) are expected to be strongly type I

  2. Space-optimized texture atlases

    OpenAIRE

    Martínez Bayona, Jonàs

    2009-01-01

    Texture atlas parameterization provides an effective way to map a variety of colour and data attributes from 2D texture domains onto polygonal surface meshes. Most of the existing literature focus on how to build seamless texture atlases for continuous photometric detail, but little e ort has been devoted to devise e cient techniques for encoding self-repeating, uncontinuous signals such as building facades. We present a perception-based scheme for generating space-optimized texture ...

  3. Mechanisms of texture evolution during annealing of Zr and Ti alloys

    International Nuclear Information System (INIS)

    Gerspacher, F.

    2007-12-01

    Zirconium and Titanium are hexagonal metals. Thus, they have a weaker symmetry than cubic metals, and a stronger crystalline anisotropy. Despite this strong anisotropy, the fundamental mechanisms of the texture evolution of these metals have not been deeply investigated yet. We studied here the texture and microstructure evolution during annealing after several conditions of deformation, and showed that: - slow texture change is expected in grain growth after severe rolling, because of oriented growth - rapid texture change after low reductions is due to oriented nucleation - transverse rolling gives rise to a correlation between orientation and stored energy in the deformed material, which also induces fast texture changes. These mechanisms have been explained on the basis of microstructure specificities. In addition, texture evolution during normal grain growth was studied and the use of modeling allowed to confirm some hypotheses made on boundary mobility anisotropy. The mechanisms of appearance of abnormal grain growth have also been clarified. (author)

  4. Parallel-Sequential Texture Analysis

    NARCIS (Netherlands)

    van den Broek, Egon; Singh, Sameer; Singh, Maneesha; van Rikxoort, Eva M.; Apte, Chid; Perner, Petra

    2005-01-01

    Color induced texture analysis is explored, using two texture analysis techniques: the co-occurrence matrix and the color correlogram as well as color histograms. Several quantization schemes for six color spaces and the human-based 11 color quantization scheme have been applied. The VisTex texture

  5. Nonlinear operator for oriented texture

    NARCIS (Netherlands)

    Kruizinga, Peter; Petkov, Nikolay

    1999-01-01

    Texture is an important part of the visual world of animals and humans and their visual systems successfully detect, discriminate, and segment texture. Relatively recently progress was made concerning structures in the brain that are presumably responsible for texture processing. Neurophysiologists

  6. Facile Formation of High-quality InGaN/GaN Quantum-disks-in-Nanowires on Bulk-Metal Substrates for High-power Light-emitters

    KAUST Repository

    Zhao, Chao

    2016-01-08

    High-quality nitride materials grown on scalable and low-cost metallic substrates are considerably attractive for high-power light emitters. We demonstrate here, for the first time, the high-power red (705 nm) InGaN/GaN quantum-disks (Qdisks)-in-nanowire light-emitting diodes (LEDs) self-assembled directly on metal-substrate. The LEDs exhibited a low turn-on voltage of ~2 V without efficiency droop up to injection current of 500 mA (1.6 kA/cm2) at ~5 V. This is achieved through the direct growth and optimization of high-quality nanowires on titanium (Ti) coated bulk polycrystalline-molybdenum (Mo) substrates. We performed extensive studies on the growth mechanisms, obtained high-crystal-quality nanowires, and confirmed the epitaxial relationship between the cubic titanium nitride (TiN) transition layer and the hexagonal nanowires. The growth of nanowires on all-metal stack of TiN/Ti/Mo enables simultaneous implementation of n-metal contact, reflector and heat-sink, which greatly simplifies the fabrication process of high-power light emitters. Our work ushers in a practical platform for high-power nanowires light emitters, providing versatile solutions for multiple cross-disciplinary applications that are greatly enhanced by leveraging on the chemical stability of nitride materials, large specific surface of nanowires, chemical lift-off ready layer structures, and reusable Mo substrates.

  7. High-quality III-V semiconductor MBE growth on Ge/Si virtual substrates for metal-oxide-semiconductor device fabrication

    Science.gov (United States)

    Choi, Donghun; Harris, James S.; Kim, Eunji; McIntyre, Paul C.; Cagnon, Joel; Stemmer, Susanne

    2009-03-01

    We describe the molecular-beam epitaxial (MBE) growth and fabrication of III-V metal-oxide-semiconductor (MOS) devices on Ge/Si virtual substrates. We show that high-temperature in-situ H 2 annealing in the chemical-vapor deposition system changes the Ge surface configuration and produces a surface with predominantly double-step-layer conditions, which is crucial for the growth of single-domain GaAs. In addition, the surface morphology of III-V on Ge/Si improved significantly with an annealing treatment of the Ge surface carried out under high arsenic background pressure in the MBE chamber. This facilitates uniform As-monolayer formation on the entire Ge surface. Low-temperature migration-enhanced epitaxy (MEE) and low-temperature conventional GaAs growth not only enhance the growth of single-domain GaAs without Ge outdiffusion but also produce a sufficiently smooth surface for high-k dielectric deposition, achieving low leakage current. A 300-nm-thick GaAs buffer layer was grown, followed by a 10 nm growth of In 0.2Ga 0.8As high-mobility channel layer. A 7-8-nm-thick Al 2O 3 layer was deposited ex-situ by atomic-layer deposition (ALD). We verify the quality of III-V growth using transmission electron microscopy (TEM), X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS) and photoluminescence (PL) measurement. The C-V characteristics show unpinning of the Fermi level, which is a necessary condition for gate voltage control of the drain current. This work suggests this materials combination is a promising candidate for the realization of advanced, nonclassical complementary-MOS and optoelectronic devices on Si substrates.

  8. Simulating X-ray diffraction of textured films

    DEFF Research Database (Denmark)

    Breiby, Dag W.; Bunk, Oliver; Andreasen, Jens Wenzel

    2008-01-01

    Computationally efficient simulations of grazing-incidence X-ray diffraction (GIXD) are discussed, with particular attention given to textured thin polycrystalline films on supporting substrates. A computer program has been developed for simulating scattering from thin films exhibiting varying...... from the totally substrate-reflected beam ( two-beam approximation) and refraction effects are also included in the program, together with the geometrical intensity corrections associated with GIXD measurements. To achieve 'user friendliness' for scientists less familiar with diffraction...

  9. Quantification of elemental area densities in multiple metal layers (Au/Ni/Cu) on a Cr-coated quartz glass substrate for certification of NMIJ CRM 5208-a.

    Science.gov (United States)

    Ariga, Tomoko; Zhu, Yanbei; Ito, Mika; Takatsuka, Toshiko; Terauchi, Shinya; Kurokawa, Akira; Inagaki, Kazumi

    2018-04-01

    Area densities of Au/Ni/Cu layers on a Cr-coated quartz substrate were characterized to certify a multiple-metal-layer certified reference material (NMIJ CRM5208-a) that is intended for use in the analysis of the layer area density and the thickness by an X-ray fluorescence spectrometer. The area densities of Au/Ni/Cu layers were calculated from layer mass amounts and area. The layer mass amounts were determined by using wet chemical analyses, namely inductively coupled plasma mass spectrometry (ICP-MS), isotope-dilution (ID-) ICP-MS, and inductively coupled plasma optical emission spectrometry (ICP-OES) after dissolving the layers with diluted mixture of HCl and HNO 3 (1:1, v/v). Analytical results of the layer mass amounts obtained by the methods agreed well with each another within their uncertainty ranges. The area of the layer was determined by using a high-resolution optical scanner calibrated by Japan Calibration Service System (JCSS) standard scales. The property values of area density were 1.84 ± 0.05 μg/mm 2 for Au, 8.69 ± 0.17 μg/mm 2 for Ni, and 8.80 ± 0.14 μg/mm 2 for Cu (mean ± expanded uncertainty, coverage factor k = 2). In order to assess the reliability of these values, the density of each metal layer calculated from the property values of the area density and layer thickness measured by using a scanning electron microscope were compared with available literature values and good agreement between the observed values and values obtained in previous studies.

  10. Correlation between texture and mechanical stress durability of thin aluminum films

    Energy Technology Data Exchange (ETDEWEB)

    Nüssl, R., E-mail: rudolf.nuessl@uct.ac.za [Institut für Physik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg (Germany); Jewula, T.; Ruile, W. [TDK Corporation, Systems, Acoustics, Waves Business Group, Anzingerstraße 13, 81617 Munich (Germany); Sulima, T.; Hansch, W. [Institut für Physik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg (Germany)

    2014-04-01

    In this article, differently textured aluminum (Al) metallizations of surface acoustic wave (SAW) devices have been exposed to cyclic mechanical stress in order to investigate a potential correlation between their texture and their mechanical stress durability. Samples of SAW devices with differently textured Al thin film electrodes have been manufactured, and texture measurements have been carried out on all samples with electron backscatter diffraction. Subsequently, the SAW devices have been operated at heavy electrical load until a defined mechanical fatigue of its Al electrodes occurred. SAW devices with highly textured Al electrodes showed almost 20 times higher power durability than SAW devices with untextured Al electrodes. We show that this increase in electrical power durability has to be fully attributed to the strongly enhanced mechanical stress durability of highly textured Al films. Furthermore, a positive correlation between the Al films' texture and its electrical conductivity has been found. - Highlights: • We show highly textured growth of thin Al films on a clean, monocrystalline LiTaO{sub 3} • Highly textured Al growth gets disturbed by prior photolithographic process steps • Power durability of a SAW device increases with texture of its metallizationTexture and mechanical stress durability of a thin Al film are tightly correlated.

  11. Direct Synthesis of Carbon Nanotube Field Emitters on Metal Substrate for Open-Type X-ray Source in Medical Imaging

    Directory of Open Access Journals (Sweden)

    Amar Prasad Gupta

    2017-07-01

    Full Text Available We report the design, fabrication and characterization of a carbon nanotube enabled open-type X-ray system for medical imaging. We directly grew the carbon nanotubes used as electron emitter for electron gun on a non-polished raw metallic rectangular-rounded substrate with an area of 0.1377 cm2 through a plasma enhanced chemical vapor deposition system. The stable field emission properties with triode electrodes after electrical aging treatment showed an anode emission current of 0.63 mA at a gate field of 7.51 V/μm. The 4.5-inch cubic shape open type X-ray system was developed consisting of an X-ray aperture, a vacuum part, an anode high voltage part, and a field emission electron gun including three electrodes with focusing, gate and cathode electrodes. Using this system, we obtained high-resolution X-ray images accelerated at 42–70 kV voltage by digital switching control between emitter and ground electrode.

  12. Al0.3Ga0.7As/GaAs metal-insulator-semiconductor-type field-effect transistor fabricated on an InP substrate

    Science.gov (United States)

    Agarwala, S.; Patil, M. B.; Peng, C. K.; Morkoç, H.

    1988-08-01

    A metal-insulator-semiconductor-type Al0.3Ga0.7As/GaAs field-effect transistor with 1-μm-long by 145-μm-wide gates and intrinsic transconductance of 180 mS/mm has been demonstrated on an InP substrate. The dislocation propagation is minimized by incorporating a superlattice on InP, and a 1.5 μm undoped GaAs buffer layer is grown prior to the actual channel to ensure good quality of the 250 Å active layer. A channel mobility of 1920 cm2/(V s) and a carrier concentration of 1.28×1018 cm-3 have been measured at 300 K. The device exhibits excellent pinch-off, and the gate-to-source reverse breakdown voltage is greater than 5 V. The low output conductance of 2.5 mS/mm indicated small parallel conduction in the undoped GaAs buffer layer. Also, very little hysteresis was found in the current-voltage characteristics, implying few traps in the epilayer.

  13. One-shot deep-UV pulsed-laser-induced photomodification of hollow metal nanoparticles for high-density data storage on flexible substrates.

    Science.gov (United States)

    Wan, Dehui; Chen, Hsuen-Li; Tseng, Shao-Chin; Wang, Lon A; Chen, Yung-Pin

    2010-01-26

    In this paper, we report a new optical data storage method: photomodification of hollow gold nanoparticle (HGN) monolayers induced by one-shot deep-ultraviolet (DUV) KrF laser recording. As far as we are aware, this study is the first to apply HGNs in optical data storage and also the first to use a recording light source for the metal nanoparticles (NPs) that is not a surface plasmon resonance (SPR) wavelength. The short wavelength of the recording DUV laser improved the optical resolution dramatically. We prepared HGNs exhibiting two absorbance regions: an SPR peak in the near-infrared (NIR) region and an intrinsic material extinction in the DUV region. A single pulse from a KrF laser heated the HGNs and transformed them from hollow structures to smaller solid spheres. This change in morphology for the HGNs was accompanied by a significant blue shift of the SPR peak. Employing this approach, we demonstrated its patterning ability with a resolving power of a half-micrometer (using a phase mask) and developed a readout method (using a blue-ray laser microscope). Moreover, we prepared large-area, uniform patterns of monolayer HGNs on various substrates (glass slides, silicon wafers, flexible plates). If this spectral recording technique could be applied onto thin flexible tapes, the recorded data density would increase significantly relative to that of current rigid discs (e.g., compact discs).

  14. Substrate specificity, metal binding properties, and spectroscopic characterization of the DapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Haemophilus influenzae.

    Science.gov (United States)

    Bienvenue, David L; Gilner, Danuta M; Davis, Ryan S; Bennett, Brian; Holz, Richard C

    2003-09-16

    The catalytic and structural properties of divalent metal ion cofactor binding sites in the dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae were investigated. Co(II)-substituted DapE enzyme was 25% more active than the Zn(II)-loaded form of the enzyme. Interestingly, Mn(II) can activate DapE, but only to approximately 20% of the Zn(II)-loaded enzyme. The order of the observed k(cat) values are Co(II) > Zn(II) > Cd(II) > Mn(II) >Ni(II) approximately equal Cu(II) approximately equal Mg(II). DapE was shown to only hydrolyze L,L-N-succinyl-diaminopimelic acid (L,L-SDAP) and was inactive toward D,L-, L,D-, and D,D-SDAP. DapE was also inactive toward several acetylated amino acids as well as D,L-succinyl aminopimelate, which differs from the natural substrate, L,L-SDAP, by the absence of the amine group on the amino acid side chain. These data imply that the carboxylate of the succinyl moiety and the amine form important interactions with the active site of DapE. The affinity of DapE for one versus two Zn(II) ions differs by nearly 2.2 x 10(3) times (K(d1) = 0.14 microM vs K(d2) = 300 microM). In addition, an Arrhenius plot was constructed from k(cat) values measured between 16 and 35 degrees C and was linear over this temperature range. The activation energy for [ZnZn(DapE)] was found to be 31 kJ/mol with the remaining thermodynamic parameters calculated at 25 degrees C being DeltaG(++) = 64 kJ/mol, DeltaH(++) = 28.5 kJ/mol, and DeltaS(++) = -119 J mol(-1) K(-1). Electronic absorption and EPR spectra of [Co_(DapE)] and [CoCo(DapE)] indicate that the first Co(II) binding site is five-coordinate, while the second site is octahedral. In addition, any spin-spin interaction between the two Co(II) ions in [CoCo(DapE)] is very weak. The kinetic and spectroscopic data presented herein suggest that the DapE from H. influenzae has similar divalent metal binding properties to the aminopeptidase from Aeromonas proteolytica (AAP), and

  15. Local Treatment for Monochrome Outdoor Painted Metal Sculptures: Assessing the suitability of conservation paints for retouching

    OpenAIRE

    van Basten, Nikki; Defeyt, Catherine; Rivenc, Rachel

    2015-01-01

    When outdoor painted sculptures get chipped, scratched or abraded, conservators might consider local retouching treatments as an option that would protect the exposed metal substrate and restore the aesthetic integrity, thus postponing a very costly and invasive overall repainting. Unfortunately, matching colour gloss and texture on large monochrome surfaces is always challenging. This paper reports on research undertaken to investigate some of the materials and application techniques that co...

  16. Direct cooled power electronics substrate

    Science.gov (United States)

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  17. Seismic texture classification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinther, R.

    1997-12-31

    The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

  18. Impact of substrate contamination with mycotoxins, heavy metals and pesticides on the growth performance and composition of black soldier fly larvae (Hermetia illucens) for use in the feed and food value chain.

    Science.gov (United States)

    Purschke, Benedict; Scheibelberger, Rafaela; Axmann, Sonja; Adler, Andreas; Jäger, Henry

    2017-08-01

    Edible insects have emerged as an alternative and sustainable source of high-quality, animal-derived protein and fat for livestock production or direct human nutrition. During the production of insects, substrate quality is a key parameter to assure optimal insect biomass gain as well as the safety of feed and food derived from commercially reared insects. Therefore, the influence of a realistic substrate contamination scenario on growth performance and accumulation behaviour of black soldier fly larvae (BSFL; Hermetia illucens L.) was investigated. Newly hatched larvae were fed on a corn-based substrate spiked with heavy metals (As, Cd, Cr, Hg, Ni, Pb), mycotoxins (aflatoxins B1/B2/G2, deoxynivalenol, ochratoxin A, zearalenone) and pesticides (chlorpyrifos, chlorpyrifos-methyl, pirimiphos-methyl) under defined breeding conditions (10 days, 28°C, 67% relative humidity). The extent of contaminants' bioaccumulation in the larval tissue as well as the effect on growing determinants were examined. The applied heavy metal substrate contamination was shown to impair larval growing indicated by significantly lower post-trial larval mass and feed conversion ratio (FCR). Cd and Pb accumulation factors of 9 and 2, respectively, were determined, while the concentrations of other heavy metals in the larvae remained below the initial substrate concentration. In contrast, mycotoxins and pesticides have neither been accumulated in the larval tissue nor significantly affected the growing determinants in comparison with the control. The use of BSFL as livestock feed requires contaminant monitoring - especially for Cd and Pb - in the substrates as well as in feedstuff containing BSFL to ensure feed and food safety along the value chain.

  19. Combination of Functional Nanoengineering and Nanosecond Laser Texturing for Design of Superhydrophobic Aluminum Alloy with Exceptional Mechanical and Chemical Properties.

    Science.gov (United States)

    Boinovich, Ludmila B; Modin, Evgeny B; Sayfutdinova, Adeliya R; Emelyanenko, Kirill A; Vasiliev, Alexander L; Emelyanenko, Alexandre M

    2017-10-24

    Industrial application of metallic materials is hindered by several shortcomings, such as proneness to corrosion, erosion under abrasive loads, damage due to poor cold resistance, or weak resistance to thermal shock stresses, etc. In this study, using the aluminum-magnesium alloy as an example of widely spread metallic materials, we show that a combination of functional nanoengineering and nanosecond laser texturing with the appropriate treatment regimes can be successfully used to transform a metal into a superhydrophobic material with exceptional mechanical and chemical properties. It is demonstrated that laser chemical processing of the surface may be simultaneously used to impart multimodal roughness and to modify the composition and physicochemical properties of a thick surface layer of the substrate itself. Such integration of topographical and physicochemical modification leads to specific surface nanostructures such as nanocavities filled with hydrophobic agent and hard oxynitride nanoinclusions. The combination of superhydrophobic state, nano- and micro features of the hierarchical surface, and the appropriate composition of the surface textured layer allowed us to provide the surface with the outstanding level of resistance of superhydrophobic coatings to external chemical and mechanical impacts. In particular, experimental data presented in this study indicate high resistance of the fabricated coatings to pitting corrosion, superheated water vapor, sand abrasive wear, and rapid temperature cycling from liquid nitrogen to room temperatures, without notable degradation of superhydrophobic performance.

  20. RotoTexture: automated tools for texturing raw video.

    Science.gov (United States)

    Fang, Hui; Hart, John C

    2006-01-01

    We propose a video editing system that allows a user to apply a time-coherent texture to a surface depicted in the raw video from a single uncalibrated camera, including the surface texture mapping of a texture image and the surface texture synthesis from a texture swatch. Our system avoids the construction of a 3D shape model and instead uses the recovered normal field to deform the texture so that it plausibly adheres to the undulations of the depicted surface. The texture mapping method uses the nonlinear least-squares optimization of a spring model to control the behavior of the texture image as it is deformed to match the evolving normal field through the video. The texture synthesis method uses a coarse optical flow to advect clusters of pixels corresponding to patches of similarly oriented surface points. These clusters are organized into a minimum advection tree to account for the dynamic visibility of clusters. We take a rather crude approach to normal recovering and optical flow estimation, yet the results are robust and plausible for nearly diffuse surfaces such as faces and t-shirts.

  1. Texture Enhanced Appearance Models

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Stegmann, Mikkel Bille; Darkner, Sune

    2007-01-01

    Statistical region-based registration methods such as the Active Appearance Model (AAM) are used for establishing dense correspondences in images. At low resolution, images correspondences can be recovered reliably in real-time. However, as resolution increases this becomes infeasible due...... to excessive storage and computational requirements. We propose to reduce the dimensionality of the textural components by selecting a subset of basis functions from a larger dictionary, estimate regression splines and model only the coeffcients of the retained basis functions. We demonstrate the use of two...

  2. A crystallographic texture perspective formability investigation of aluminium 5052 alloy sheets at various annealing temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Narayanasamy, R. [Department of Production Engineering, National Institute of Technology, Tiruchirappalli - 620015, Tamilnadu (India); Ravindran, R. [Department of Mechanical Engineering, VLB Janakiammal College of Engineering and Technology, Coimbatore - 641042, Tamilnadu (India)], E-mail: mceravindran@yahoo.co.in; Manonmani, K. [Department of Mechanical Engineering, Government College of Technology, Coimbatore - 641013, Tamilnadu (India)], E-mail: manokmani@yahoo.co.in; Satheesh, J. [Department of Production Engineering, National Institute of Technology, Tiruchirappalli - 620015, Tamilnadu (India)

    2009-05-15

    Formability, an important mechanical property of the sheet metal is strongly reliant on the crystallographic texture. Consequently deep drawability is also influenced. This paper deals with the perspective of crystallographic texture and its relevance with the formability of AA 5052 aluminium alloy sheet of 2 mm thickness annealed at four different temperatures namely 200 deg. C, 250 deg. C, 300 deg. C and 350 deg. C. Forming limit diagrams determined and plotted experimentally, their crystallographic textures obtained and their ODF plots prepared by X-ray diffraction were analyzed. The Forming limit diagrams (FLDs) of AA 5052 sheets annealed under different temperatures were examined with respect to the crystallographic texture point of view. The FLDs and crystallographic textures were then correlated with normal anisotropy of the sheet metal. It was found that the formability of aluminium alloy AA 5052 annealed at 350 deg. C possessed good formability, optimal texture and high normal anisotropy value.

  3. Surface texture and hardness of dental alloys processed by alternative technologies

    Science.gov (United States)

    Porojan, Liliana; Savencu, Cristina E.; Topală, Florin I.; Porojan, Sorin D.

    2017-08-01

    Technological developments have led to the implementation of novel digitalized manufacturing methods for the production of metallic structures in prosthetic dentistry. These technologies can be classified as based on subtractive manufacturing, assisted by computer-aided design/computer-aided manufacturing (CAD/CAM) systems, or on additive manufacturing (AM), such as the recently developed laser-based methods. The aim of the study was to assess the surface texture and hardness of metallic structures for dental restorations obtained by alternative technologies: conventional casting (CST), computerized milling (MIL), AM power bed fusion methods, respective selective laser melting (SLM) and selective laser sintering (SLS). For the experimental analyses metallic specimens made of Co-Cr dental alloys were prepared as indicated by the manufacturers. The specimen structure at the macro level was observed by an optical microscope and micro-hardness was measured in all substrates. Metallic frameworks obtained by AM are characterized by increased hardness, depending also on the surface processing. The formation of microstructural defects can be better controlled and avoided during SLM and MIL process. Application of power bed fusion techniques, like SLS and SLM, is currently a challenge in dental alloys processing.

  4. Textured YBCO films grown on wires: application to superconducting cables

    International Nuclear Information System (INIS)

    Dechoux, N; Jiménez, C; Chaudouët, P; Rapenne, L; Sarigiannidou, E; Robaut, F; Petit, S; Garaudée, S; Porcar, L; Soubeyroux, J L; Odier, P; Bruzek, C E; Decroux, M

    2012-01-01

    Efforts to fabricate superconducting wires made of YBa 2 Cu 3 O 7 (YBCO) on La 2 Zr 2 O 7 (LZO) buffered and biaxially textured Ni-5 at.%W (NiW) are described. Wires were manually shaped from LZO buffered NiW tapes. Different diameters were produced: 1.5, 2 and 3 mm. The wires were further covered with YBCO grown by metal organic chemical vapor deposition (MOCVD). We developed an original device in which the round substrate undergoes an alternated rotation of 180° around its axis in addition to a reel-to-reel translation. This new approach allows covering the whole circumference of the wire with a YBCO layer. This was confirmed by energy dispersive x-ray spectroscopy (EDX) analysis coupled to a scanning electron microscope (SEM). For all wire diameters, the YBCO layer thickness varied from 300 to 450 nm, and the cationic composition was respected. Electron backscattering diffraction (EBSD) measurements were performed directly on an as-deposited wire without surface preparation allowing the investigation of the crystalline quality of the film surface. Combining EBSD with XRD results we show that YBCO grows epitaxially on the LZO buffered NiW wires. For the first time, superconductive behaviors have been detected on round substrates in both the rolling and circular direction. J c reached 0.3 MA cm −2 as measured at 77 K by transport and third-harmonic detection. Those preliminary results confirm the effectiveness of the MOCVD for complex geometries, especially for YBCO deposition on small diameter wires. This approach opens huge perspectives for the elaboration of a new generation of YBCO-based round conductors. (paper)

  5. Neutron diffraction texture analysis of multi-phase systems

    International Nuclear Information System (INIS)

    Brokmeier, H.G.

    1989-01-01

    Neutron diffraction methods for texture analysis are closely parallel to well-known X-ray diffraction techniques. The chief advantage of neutron diffraction over X-ray diffraction, however, arises from the fact that the interaction of neutrons with matter is relatively weak, and consequently the penetration depth of neutrons is 10 2 -10 3 times larger than that of X-rays. Hence neutron diffraction is an efficient tool for measuring textures in multi-phase systems. Based on the high transmission of a neutron beam the effect of anisotropic absorption in multi-phase materials can be neglected in most cases. Moreover, the analysis of bulk textures becomes possible, such that textures in a wide variety of multi-phase systems can be studied which are of special interest in engineering and science (metals, alloys, composites, ceramics and geological specimens). (orig.)

  6. Tape Textured Works of Art

    Science.gov (United States)

    Skophammer, Karen

    2009-01-01

    Texture is how things feel or how they look as though they might feel if one touches them. Some surfaces are rough and some are smooth to the touch. There are many other words, such as bumpy, used to describe texture when one feels or sees it. This article presents an art project in which elementary students explain how texture is used in art,…

  7. Texture determination by neutron diffraction

    International Nuclear Information System (INIS)

    Dervin, P.

    1981-02-01

    Application of neutron diffraction to crystallographic texture determination shows many advantages: possibility of an important grain size, the quantity of material contributing to diffraction is more important than with X rays, good accuracy and complete pole figures are obtained by transmission only eliminating corrections needed with X rays. Texture determination allows control and improvement of material quality. Texture studies give good informations on mechanisms occuring in deformation or recrystallization of polycrystals and on anisotropy of physical and mechanical properties [fr

  8. General relativistic collapse of textures

    International Nuclear Information System (INIS)

    Durrer, R.; Heusler, M.; Jetzer, P.; Straumann, N.

    1991-01-01

    We present an exact self-similar solution of the coupled Einstein-σ model equations which describes the general relativistic collapse of global textures. In one coordinate system the texture geometry has a simple interpretation in terms of a deficit solid angle. We also briefly discuss the behavior of matter and light in this geometry. In particular we show that the weak field approximation for the metric perturbations of flat space texture solutions is quantitatively quite reliable. (orig.)

  9. SERS substrate and a method of providing a SERS substrate

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2011116089A A substrate primarily for SERS determination, the substrate has a number of elongate elements with a density of at least 1x108 elongate elements per cm2 and having metal coated tips. When the elements may be made to lean toward each other, such as by providing a drop...

  10. LOCAL TEXTURE DESCRIPTION FRAMEWORK FOR TEXTURE BASED FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    R. Reena Rose

    2014-02-01

    Full Text Available Texture descriptors have an important role in recognizing face images. However, almost all the existing local texture descriptors use nearest neighbors to encode a texture pattern around a pixel. But in face images, most of the pixels have similar characteristics with that of its nearest neighbors because the skin covers large area in a face and the skin tone at neighboring regions are same. Therefore this paper presents a general framework called Local Texture Description Framework that uses only eight pixels which are at certain distance apart either circular or elliptical from the referenced pixel. Local texture description can be done using the foundation of any existing local texture descriptors. In this paper, the performance of the proposed framework is verified with three existing local texture descriptors Local Binary Pattern (LBP, Local Texture Pattern (LTP and Local Tetra Patterns (LTrPs for the five issues viz. facial expression, partial occlusion, illumination variation, pose variation and general recognition. Five benchmark databases JAFFE, Essex, Indian faces, AT&T and Georgia Tech are used for the experiments. Experimental results demonstrate that even with less number of patterns, the proposed framework could achieve higher recognition accuracy than that of their base models.

  11. Cytokine induction of sol–gel-derived TiO2 and SiO2 coatings on metallic substrates after implantation to rat femur

    Science.gov (United States)

    Urbanski, Wiktor; Marycz, Krzysztof; Krzak, Justyna; Pezowicz, Celina; Dragan, Szymon Feliks

    2017-01-01

    Material surface is a key determinant of host response on implanted biomaterial. Therefore, modification of the implant surface may optimize implant–tissue reactions. Inflammatory reaction is inevitable after biomaterial implantation, but prolonged inflammation may lead to adverse reactions and subsequent implant failure. Proinflammatory activities of cytokines like interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are attractive indicators of these processes and ultimately characterize biocompatibility. The objective of the study was to evaluate local cytokine production after implantation of stainless steel 316L (SS) and titanium alloy (Ti6Al4V) biomaterials coated with titanium dioxide (TiO2) and silica (SiO2) coatings prepared by sol–gel method. Biomaterials were implanted into rat femur and after 12 weeks, bones were harvested. Bone–implant tissue interface was evaluated; immunohistochemical staining was performed to identify IL-6, TNF-α, and Caspase-1. Histomorphometry (AxioVision Rel. 4.6.3 software) of tissue samples was performed in order to quantify the cytokine levels. Both the oxide coatings on SS and Ti6Al4V significantly reduced cytokine production. However, the lowest cytokine levels were observed in TiO2 groups. Cytokine content in uncoated groups was lower in Ti6Al4V than in SS, although coating of either metal reduced cytokine production to similar levels. Sol–gel TiO2 or SiO2 coatings reduced significantly the production of proinflammatory cytokines by local tissues, irrespective of the material used as a substrate, that is, either Ti6Al4V or SS. This suggests lower inflammatory response, which directly points out improvement of materials’ biocompatibility. PMID:28280331

  12. Ligating Dopamine as Signal Trigger onto the Substrate via Metal-Catalyst-Free Click Chemistry for "Signal-On" Photoelectrochemical Sensing of Ultralow MicroRNA Levels.

    Science.gov (United States)

    Ye, Cui; Wang, Min Qiang; Gao, Zhong Feng; Zhang, Ying; Lei, Jing Lei; Luo, Hong Qun; Li, Nian Bing

    2016-12-06

    The efficiency of photon-to-electron conversion is extremely restricted by the electron-hole recombinant. Here, a new photoelectrochemical (PEC) sensing platform has been established based on the signal amplification of click chemistry (CC) via hybridization chain reaction (HCR) for highly sensitive microRNA (miRNA) assay. In this proposal, a preferred electron donor dopamine (DA) was first assembled with designed ligation probe (probe-N 3 ) via amidation reaction to achieve DA-coordinated signal probe (P DA -N 3 ). The P DA -N 3 served as a flexible trigger to signal amplification through efficiently suppressing the electron-hole recombinant. Specifically, the P DA -N 3 can be successfully ligated into the trapped hairpins (H1 and H2) via the superior ligation method of metal-catalyst-free CC, in which the electron donor DA was introduced into the assay system. Moreover, the enzyme-free HCR, employed as a versatile amplification way, ensures that lots of P DA -N 3 can be attached to the substrate. This PEC sensing for miRNA-141 detection illustrated the outstanding linear response to a concentration variation from 0.1 fM to 0.5 nM and a detection limit down to 27 aM, without additional electron donors. The sensor is further employed to monitor miRNA-141 from prostate carcinoma cell (22Rv1), showing good quantitative detection capability. This strategy exquisitely influences the analytical performance and offers a new PEC route to highly selective and sensitive detection of biological molecules.

  13. Surface texturing of superconductors by controlled oxygen pressure

    Science.gov (United States)

    Chen, N.; Goretta, K.C.; Dorris, S.E.

    1999-01-05

    A method of manufacture of a textured layer of a high temperature superconductor on a substrate is disclosed. The method involves providing an untextured high temperature superconductor material having a characteristic ambient pressure peritectic melting point, heating the superconductor to a temperature below the peritectic temperature, establishing a reduced pO{sub 2} atmosphere below ambient pressure causing reduction of the peritectic melting point to a reduced temperature which causes melting from an exposed surface of the superconductor and raising pressure of the reduced pO{sub 2} atmosphere to cause solidification of the molten superconductor in a textured surface layer. 8 figs.

  14. Triangular Graphene Grain Growth on Cube-Textured Cu Substrates

    Science.gov (United States)

    2011-01-01

    semiconductor with extremely high carrier mobility and a single layer of graphene absorbs only 2.3% of visible light. [ 3 , 4 ] Many applications have...rate of CuOx decreases with decreasing H 2 partial pressure. [ 32 ] According to the Cu-O phase diagram, [ 33 ] the eutectic temperature of Cu- CuO and

  15. Crystallographic texture and mechanical anisotropy of zircaloys

    International Nuclear Information System (INIS)

    Hussien, S.A.

    1987-01-01

    Hexagonal-closed-packed metals are inherently anisotropic, and deformation during processing leads to the development of preferred orientation or texture in the finished product. Tube Reduced Extrusions (TREXs) are an intermediate product in the production of zircaloy canning tubes for nuclear reactors. The objective of this research has been to study the mechanical anisotropy which has a direct relation to the formability of Zircaloy TREXs. Anisotropy parameters (R and P) in the modified Hills equation were investigated. The use of the impression test for measuring R and P under different annealing temperatures, test temperatures and strain rates, and the grid-analysis technique for measuring R and P gradients through the TREX thickness are demonstrated. The mechanical-test results are compared with the predictions of the Bishop-Hill model using the quantitative orientation distribution function. There is a good agreement between the model prediction and the mechanical-test data. The value of R was found to be insensitive to the strain rate, test temperature, annealing temperature, and texture gradient. The value of P was found to increase with the annealing temperature within the recrystallization range and to be relatively insensitive elsewhere, to decrease with increasing test temperature and to be considerable sensitive to texture gradient

  16. Methods of etching a substrate

    International Nuclear Information System (INIS)

    Cosmo, J.J.; Gambino, R.J.; Harper, J.M.E.

    1979-01-01

    The invention relates to a method of etching a substrate. The substrate is located opposite a target electrode in a vacuum chamber, and the surface of the target electrode is bombarded with energetic particles of atomic dimensions. The target electrode is an intermetallic composition (compound, alloy or finely divided homogeneous mixture) of two metals A and B such that upon bombardment the electrode emits negative ions of metal B which have sufficient energy to produce etching of the substrate. Many target materials are exemplified. Typically the metal A has an electronegativity XA and metal B has an electronegativity XB such that Xb - Xa is greater than about 2.55 electron volts, with the exception of combinations of metals having a fractional ionicity Q less than about 0.314. The source of the energetic particles may be an ionised gas in the vacuum chamber. The apparatus and its mode of operation are described in detail. (U.K.)

  17. Laser surface textured titanium alloy (Ti–6Al–4V): Part 1 – Surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Pfleging, Wilhelm [Karlsruhe Institute of Technology, IAM-AWP, P.O. Box 3640, 76021 Karlsruhe (Germany); Karlsruhe Nano Micro Facility, H.-von-Helmholtz-Pl. 1, 76344 Egg.-Leopoldshafen (Germany); Kumari, Renu [Department of Metal. and Maters. Eng., I. I. T. Kharagpur, WB 721302 (India); Besser, Heino [Karlsruhe Institute of Technology, IAM-AWP, P.O. Box 3640, 76021 Karlsruhe (Germany); Scharnweber, Tim [Karlsruhe Institute of Technology, IBG-1, P.O. Box 3640, 76021 Karlsruhe (Germany); Majumdar, Jyotsna Dutta, E-mail: jyotsna@metal.iitkgp.ernet.in [Department of Metal. and Maters. Eng., I. I. T. Kharagpur, WB 721302 (India)

    2015-11-15

    Highlights: • Texturing of Ti–6Al–4V with linear and dimple patterns are developed with ArF laser. • Linear textures have width of 25 μm and are at an interval of 20 μm. • Dimple textures are equi-spaced and have a diameter of 60 μm. • Significant refinement of microstructure in textured zone as compared to substrate. • Increased wettability of the textured surface against simulated body fluid. - Abstract: In the present study, a detailed study of the characterization of laser-surface textured titanium alloy (Ti–6Al–4V) with line and dimple geometry developed by using an ArF excimer laser operating at a wavelength of 193 nm with a pulse length of 5 ns is undertaken. The characterization of the textured surface (both the top surface and cross section) is carried out by scanning electron microscopy, electron back scattered diffraction (EBSD) technique and X-ray diffraction techniques. There is refinement of microstructure along with presence of titanium oxides (rutile, anatase and few Ti{sub 2}O{sub 3} phase) in the textured surface as compared to as-received one. The area fractions of linear texture and dimple texture measured by image analysis software are 45% and 20%, respectively. The wettability is increased after laser texturing. The total surface energy is decreased due to linear (29.6 mN/m) texturing and increased due to dimple (67.6 mN/m) texturing as compared to as-received Ti–6Al–4V (37 mN/m). The effect of polar component is more in influencing the surface energy of textured surface.

  18. Quantitative Characterisation of Surface Texture

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Lonardo, P.M.; Trumpold, H.

    2000-01-01

    This paper reviews the different methods used to give a quantitative characterisation of surface texture. The paper contains a review of conventional 2D as well as 3D roughness parameters, with particular emphasis on recent international standards and developments. It presents new texture...

  19. Emotional effects of dynamic textures

    NARCIS (Netherlands)

    Toet, A.; Henselmans, M.; Lucassen, M.P.; Gevers, T.

    2011-01-01

    This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music) and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely

  20. Cartoon+Texture Image Decomposition

    Directory of Open Access Journals (Sweden)

    Antoni Buades

    2011-09-01

    Full Text Available In this article we give a thorough description of the algorithm proposed in [A. Buades, T. Le, J.M. Morel and L. Vese, Fast cartoon + texture image filters, IEEE Transactions on Image Processing, 2010] for cartoon+texture decomposition using of a nonlinear low pass-high pass filter pair.

  1. Human versus artificial texture perception

    NARCIS (Netherlands)

    Petiet, Peter J.; van Erp, J.; Drullman, R.; van den Broek, Egon; Beintema, J.; van Wijngaarden, S.

    2006-01-01

    The performances of current texture analysis algorithms are still poor, especially when applied to a large, diffuse texture domain. Most of these purely computationally driven techniques are created to function within a highly restricted domain. When applied as computer vision techniques, frequently

  2. Emotional Effects of Dynamic Textures

    Directory of Open Access Journals (Sweden)

    Alexander Toet

    2011-12-01

    Full Text Available This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely unknown, despite their natural ubiquity and increasing use in digital media. Participants watched a set of dynamic textures, representing either water or various different media, and self-reported their emotional experience. Motion complexity was found to have mildly relaxing and nondominant effects. In contrast, motion change complexity was found to be arousing and dominant. The speed of dynamics had arousing, dominant, and unpleasant effects. The amplitude of dynamics was also regarded as unpleasant. The regularity of the dynamics over the textures' area was found to be uninteresting, nondominant, mildly relaxing, and mildly pleasant. The spatial scale of the dynamics had an unpleasant, arousing, and dominant effect, which was larger for textures with diverse content than for water textures. For water textures, the effects of spatial contrast were arousing, dominant, interesting, and mildly unpleasant. None of these effects were observed for textures of diverse content. The current findings are relevant for the design and synthesis of affective multimedia content and for affective scene indexing and retrieval.

  3. Texture dependent lattice strains and texture gradient in AI7020

    Science.gov (United States)

    Y Zhong, Z.; Brokmeier, H.-G.; Maawad, E.; Schell, N.

    2015-04-01

    Firstly, an Al7020 block was characterized by the texture gradient, which was remarkably strong. Texture sharpness in the center with about 30 mrd (multiple random distribution) shows typical plain strain texture components. On the surface and close to the surface the texture sharpness is much weaker showing also shear components. Strongest shear was not directly at the surface but 4 mm deeper. The texture analysis at HEMS Beamline (Petra III/DESY-Hamburg) was done with continuous scanning mode to include all grains to improve the grain statistics. Secondly, with an in situ synchrotron experiment the texture dependent lattice strain behavior was investigated using flat tensile samples oriented 0°, 45° and 90° to the rolling direction (RD). Texture induced anisotropy influenced on the lattice dependent yield strength and the lattice dependent stress-strain behavior, which will be discussed in detail. Due to the high energy synchrotron beam complete Debye-Scherrer rings were obtained so that the patterns, parallel and perpendicular to loading direction (LD), were obtained simultaneously.

  4. Substrate-mediated sub-diffraction guiding of optical signals through a linear chain of metal nanoparticles : Polarization dependence and the role of the dispersion relation

    NARCIS (Netherlands)

    Compaijen, P.J.; Malyshev, V.A.; Knoester, J.

    We theoretically investigate the efficiency of transmitting optical signals through a linear chain consisting of identical and equidistantly spaced silver nanoparticles in the presence of a reflecting substrate. The energy exchange between surface plasmon polaritons of the chain and the substrate

  5. In vitro formation of Ca-oxalates and the mineral glushinskite by fungal interaction with carbonate substrates and seawater

    Directory of Open Access Journals (Sweden)

    K. Kolo

    2005-01-01

    Full Text Available This study investigates the in vitro formation of Ca-oxalates and glushinskite through fungal interaction with carbonate substrates and seawater as a process of biologically induced metal recycling and neo-mineral formation. The study also emphasizes the role of the substrates as metal donors. In the first experiment, thin sections prepared from dolomitic rock samples of Terwagne Formation (Carboniferous, Viséan, northern France served as substrates. The thin sections placed in Petri dishes were exposed to fungi grown from naturally existing airborne spores. In the second experiment, fungal growth and mineral formation was monitored using only standard seawater (SSW as a substrate. Fungal growth media consisted of a high protein/carbohydrates and sugar diet with demineralized water for irrigation. Fungal growth process reached completion under uncontrolled laboratory conditions. The newly formed minerals and textural changes caused by fungal attack on the carbonate substrates were investigated using light and scanning electron microscopy (SEM-EDX, x-ray diffraction (XRD and Raman spectroscopy. The fungal interaction and attack on the dolomitic and seawater substrates resulted in the formation of Ca-oxalates (weddellite CaC2O4·2(H2O, whewellite (CaC2O4·(H2O and glushinskite MgC2O4·2(H2O associated with the destruction of the original hard substrates and their replacement by the new minerals. Both of Ca and Mg were mobilized from the experimental substrates by fungi. This metal mobilization involved a recycling of substrate metals into newly formed minerals. The biochemical and diagenetic results of the interaction strongly marked the attacked substrates with a biological fingerprint. Such fingerprints are biomarkers of primitive life. The formation of glushinskite is of specific importance that is related, besides its importance as a biomineral bearing a recycled Mg, to the possibility of its transformation through diagenetic pathway into an

  6. Evaporation dynamics of completely wetting drops on geometrically textured surfaces

    Science.gov (United States)

    Mekhitarian, Loucine; Sobac, Benjamin; Dehaeck, Sam; Haut, Benoît; Colinet, Pierre

    2017-10-01

    This study deals with the evaporation dynamics of completely wetting and highly volatile drops deposited on geometrically textured but chemically homogeneous surfaces. The texturation consists in a cylindrical pillars array with a square pitch. The triple line dynamics and the drop shape are characterized by an interferometric method. A parametric study is realized by varying the radius and the height of the pillars (at fixed interpillar distance), allowing to distinguish three types of dynamics: i) an evaporation-dominated regime with a receding triple line; ii) a spreading-dominated regime with an initially advancing triple line; iii) a cross-over region with strong pinning effects. The overall picture is in qualitative agreement with a mathematical model showing that the selected regime mostly depends on the value of a dimensionless parameter comparing the time scales for evaporation and spreading into the substrate texture.

  7. Cytokine induction of sol–gel-derived TiO2 and SiO2 coatings on metallic substrates after implantation to rat femur

    Directory of Open Access Journals (Sweden)

    Urbanski W

    2017-02-01

    Full Text Available Wiktor Urbanski,1 Krzysztof Marycz,2 Justyna Krzak,3 Celina Pezowicz,4 Szymon Feliks Dragan1 1Department of Orthopaedic Surgery and Traumatology, Wroclaw University Hospital, 2Electron Microscope Laboratory, Wroclaw University of Environmental and Life Sciences, 3Institute of Materials Science and Applied Mechanics, 4Division of Biomedical Engineering and Experimental Mechanics, Wroclaw University of Technology, Wroclaw, Poland Abstract: Material surface is a key determinant of host response on implanted biomaterial. Therefore, modification of the implant surface may optimize implant–tissue reactions. Inflammatory reaction is inevitable after biomaterial implantation, but prolonged inflammation may lead to adverse reactions and subsequent implant failure. Proinflammatory activities of cytokines like interleukin (IL-1, IL-6, and tumor necrosis factor-alpha (TNF-α are attractive indicators of these processes and ultimately characterize biocompatibility. The objective of the study was to evaluate local cytokine production after implantation of stainless steel 316L (SS and titanium alloy (Ti6Al4V biomaterials coated with titanium dioxide (TiO2 and silica (SiO2 coatings prepared by sol–gel method. Biomaterials were implanted into rat femur and after 12 weeks, bones were harvested. Bone–implant tissue interface was evaluated; immunohistochemical staining was performed to identify IL-6, TNF-α, and Caspase-1. Histomorphometry (AxioVision Rel. 4.6.3 software of tissue samples was performed in order to quantify the cytokine levels. Both the oxide coatings on SS and Ti6Al4V significantly reduced cytokine production. However, the lowest cytokine levels were observed in TiO2 groups. Cytokine content in uncoated groups was lower in Ti6Al4V than in SS, although coating of either metal reduced cytokine production to similar levels. Sol–gel TiO2 or SiO2 coatings reduced significantly the production of proinflammatory cytokines by local tissues

  8. Self-adaptive surface texture design for friction reduction across the lubrication regimes

    Science.gov (United States)

    Hsu, Stephen M.; Jing, Yang; Zhao, Fei

    2016-03-01

    Surface texturing has been shown to reduce friction and improve durability in mechanical face seals and metal forming operations, and lightly loaded thrust bearings. However, the success has been limited to conformal contacts and low load high speed operating conditions, i.e. hydrodynamic lubrication dominated regime. Both experiments and numerical simulations have shown that textural patterns, under higher loading and/or slower speeds may increase friction and even cause the lubrication film collapse. Specific designs of surface texture pattern, as its shape, depth and density, are required for different lubrication regimes. Our own study has shown (Hsu et al 2014 J. Phys. D: Appl. Phys. 47 335307) that large/shallow dimple reduces friction in hydrodynamic lubrication regime, whereas small/deep dimple shows benefit in mixed/boundary lubrication regimes (if the textural designs can provides hydrodynamic/hydrostatic lift forces to reduce the machine loading). In considering an engine component typically experiences duty cycles that may cross various lubrication regimes, a multiscale surface texture design appears attractive. This type of mixed shape texturing combines textures designed for low load, high speed operating conditions and the textures that are designed for high load, low speed operations. In this paper, two types of multiscale surface texture designs are presented. Ball-on-three-flats (BOTF) wear tester (under high loading conditions) is used to evaluate the performance of these multiscale texture designs along with the baselines of un-textured surfaces under the same surface preparation procedures. Two texture designs with only a single shape dimples are included in the study. Results suggest that multiscale surface texture design not only further reduces friction in comparison to the textures with single shape dimples, but also shows the effectiveness across hydrodynamic regimes to the mixed lubrication regimes.

  9. Growth of (100)-highly textured BaBiO{sub 3} thin films on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Ferreyra, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Departamento de Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 1, Ciudad Universitaria, Buenos Aires (Argentina); Marchini, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Departamento de Química Inorgánica, Analítica y Química-Física, INQUIMAE-CONICET, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires (Argentina); Granell, P. [INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Golmar, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, UNSAM, Campus Miguelete, 1650 San Martín, Buenos Aires (Argentina); Albornoz, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); and others

    2016-08-01

    We report on the growth and characterization of non-epitaxial but (100)-highly textured BaBiO{sub 3} thin films on silicon substrates. We have found the deposition conditions that optimize the texture, and show that the textured growth is favoured by the formation of a BaO layer at the first growth stages. X-ray diffraction Φ-scans, together with the observation that the same textured growth is found on films grown on Pt and SiO{sub 2} buffered Si, demonstrate the absence of epitaxy. Finally, we have shown that our (100)-oriented BaBiO{sub 3} films can be used as suitable buffers for the growth of textured heterostructures on silicon, which could facilitate the integration of potential devices with standard electronics. - Highlights: • BaBiO{sub 3} thin films were grown on Si substrates and characterized. • Films prepared using optimized conditions are highly textured in the (100) direction. • The absence of in-plane texture was demonstrated by X-ray diffraction. • Our films are suitable buffers for the growth of (100)-textured oxide heterostructures.

  10. Textures in Utopia Planitia

    Science.gov (United States)

    2002-01-01

    [figure removed for brevity, see original site] Bizarre textures cover the surface of eastern Utopia Planitia where there is a high probability that ground ice has played a role in the formation of this unusual landscape.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Pulsed laser deposition of YBCO films on ISD MgO buffered metal tapes

    CERN Document Server

    Ma, B; Koritala, R E; Fisher, B L; Markowitz, A R; Erck, R A; Baurceanu, R; Dorris, S E; Miller, D J; Balachandran, U

    2003-01-01

    Biaxially textured magnesium oxide (MgO) films deposited by inclined-substrate deposition (ISD) are desirable for rapid production of high-quality template layers for YBCO-coated conductors. High-quality YBCO films were grown on ISD MgO buffered metallic substrates by pulsed laser deposition (PLD). Columnar grains with a roof-tile surface structure were observed in the ISD MgO films. X-ray pole figure analysis revealed that the (002) planes of the ISD MgO films are tilted at an angle from the substrate normal. A small full-width at half maximum (FWHM) of approx 9deg was observed in the phi-scan for ISD MgO films deposited at an inclination angle of 55deg . In-plane texture in the ISD MgO films developed in the first approx 0.5 mu m from the substrate surface, and then stabilized with further increases in film thickness. Yttria-stabilized zirconia and ceria buffer layers were deposited on the ISD MgO grown on metallic substrates prior to the deposition of YBCO by PLD. YBCO films with the c-axis parallel to the...

  12. Plasma-nitriding assisted micro-texturing into stainless steel molds

    Directory of Open Access Journals (Sweden)

    Aizawa Tatsuhiko

    2015-01-01

    Full Text Available Micro-texturing has grown up to be one of the most promising procedures. This related application required for large-area, fine micro-texturing onto the stainless steel mold materials. A new method other than laser-machining, micro-milling or micro-EDM was awaited for further advancement of this micro-texturing. In the present paper, a plasma nitriding assisted micro-texturing was developed to make various kinds of micro-patterns onto the martensitic stainless steels. First, original patterns were printed onto the surface of substrate by using the ink-jet printer. Then, the masked substrate was subjected to high density plasma nitriding; the un-masked surfaces were nitrided to have higher hardness. This nitrided substrate was further treated by sand-blasting to selectively dig the soft, masked surfaces. Finally, the micro-patterned martensitic stainless steel substrate was fabricated as a mold to duplicate these micro-patterns onto the work materials. The spatial resolution and depth profile controllability of this plasma nitriding assisted micro-texturing was investigated for variety of initial micro-patterns. The original size and dimension of initial micro-patterns were precisely compared with the three dimensional geometry of micro-textures after blasting treatment. The plastic cover case for smart cellular phones was employed to demonstrate how useful this processing is in practice.

  13. Effect of surface texture by ion beam sputtering on implant biocompatibility and soft tissue attachment

    Science.gov (United States)

    Gibbons, D. F.

    1977-01-01

    The objectives in this report were to use the ion beam sputtering technique to produce surface textures on polymers, metals, and ceramics. The morphology of the texture was altered by varying both the width and depth of the square pits which were formed by ion beam erosion. The width of the ribs separating the pits were defined by the mask used to produce the texture. The area of the surface containing pits varies as the width was changed. The biological parameters used to evaluate the biological response to the texture were: (1) fibrous capsule and inflammatory response in subcutaneous soft tissue; (2) strength of the mechanical attachment of the textured surface by the soft tissue; and (3) morphology of the epidermal layer interfacing the textured surface of percutaneous connectors. Because the sputter yield on teflon ribs was approximately an order of magnitude larger than any other material the majority of the measurements presented in the report were obtained with teflon.

  14. Offshore Substrate

    Data.gov (United States)

    California Department of Resources — This shapefile displays the distribution of substrate types from Pt. Arena to Pt. Sal in central/northern California. Originally this data consisted of seven paper...

  15. Symmetry realization of texture zeros

    International Nuclear Information System (INIS)

    Grimus, W.; Joshipura, A.S.; Lavoura, L.; Tanimoto, M.

    2004-01-01

    We show that it is possible to enforce texture zeros in arbitrary entries of the fermion mass matrices by means of Abelian symmetries; in this way, many popular mass-matrix textures find a symmetry justification. We propose two alternative methods which allow one to place zeros in any number of elements of the mass matrices that one wants. They are applicable simultaneously in the quark and lepton sectors. They are also applicable in grand unified theories. The number of scalar fields required by our methods may be large; still, in many interesting cases this number can be reduced considerably. The larger the desired number of texture zeros is, the simpler are the models which reproduce the texture. (orig.)

  16. EUROMET SUPPLEMENTARY COMPARISON - SURFACE TEXTURE

    DEFF Research Database (Denmark)

    Koenders, L.; Andreasen, Jan Lasson; De Chiffre, Leonardo

    At the length meeting in Prague in Oct. 1999 a new comparison was suggested on surface texture. The last comparison on this field was finished in 1989. In the meantime the instrumentation, the standards and the written standards have been improved including some software filters. The pilot...... laboratories for this supplementary comparison on surface texture are the Centre for Geometrical Metrology at the Technical University of Denmark and the Micro- and Nanotopography laboratory at the Physikalisch-Technische Bundesanstalt, Germany....

  17. Preparation of (11n) oriented Bi2Sr2CaCu2O8+x thin films without c-axis twin structure by the metal-organic decomposition method using vicinal SrTiO3 (110) substrates

    Science.gov (United States)

    Yamada, Yasuyuki; Kato, Takahiro; Ishibashi, Takayuki; Okamoto, Tomoichiro; Mori, Natsuki

    2018-01-01

    We have prepared (11n) oriented Bi2Sr2CaCu2O8+x (Bi2212) thin films by metal-organic decomposition method. The vicinal (110) substrate of SrTiO3 (STO) inclined toward the [1 ¯ 10] direction was used for suppressing "c-twinning". In the sample prepared in the O2 atmosphere, only the (11n) peak appeared in the θ-2θ X-ray diffraction pattern. When the miscut angle of the substrate was φ = 10°, it was shown by the scanning electron microscope images and the (008) pole figures that the c-axis was inclined by about 38° and the c-twinning was substantially suppressed. ρab and ρc of this sample were calculated by the corrected van der Pauw method and component calculation of the two-dimensional resistivity tensor. The superconducting transition temperatures were Tc = 81 K. The temperature dependence of ρab was a typical metallic behavior reflecting the characteristics of the ab-plane of Bi2212. On the other hand, that of ρc did not become a typical semiconductor behavior in the c-axis direction of Bi2212, but it showed a metallic behavior. The anisotropic parameter γ was about 10.

  18. Audio Classification from Time-Frequency Texture

    OpenAIRE

    Yu, Guoshen; Slotine, Jean-Jacques

    2008-01-01

    Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired by an earlier visual classification scheme particularly efficient at classifying textures. While solely based on time-frequency texture features, the algorithm achieves surprisingly good performance in musical instrument classification experiments.

  19. Food Texture Preferences in Infants Versus Toddlers.

    Science.gov (United States)

    Lundy, Brenda; And Others

    1998-01-01

    Compared food texture preferences during infancy and toddlerhood. Found that infants displayed more negative expressions and head and body movements in response to complex textures than to simple textures. Toddlers displayed more positive head and body movements and more eagerness in response to complex than to simple textures. Experience with…

  20. Microstructure in electrodeposited copper layers; the role of the substrate

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Jensen, Jens Dahl; Horsewell, Andy

    2001-01-01

    The microstructures of Cu layers, ranging in thickness from 3 to 12 microns, were investigated. The layers were electrodeposited from an acidic copper electrolyte onto two distinct substrate materials important for the micro-components industry: an Au layer with a pronounced lll-texture, and a nano...... stongly on the crystallographic texture in the substrate. The Cu crystallites inherited the lll-orientation of the Au substrate, whilst no preferred crystallographic orientation was observed in the Cu crystallites on the nano-crystalline Ni-P substate. For Cu layers thicker than 3 microns a lll...

  1. Evaluation of Surface Cleaning Procedures for CTGS Substrates for SAW Technology with XPS

    Directory of Open Access Journals (Sweden)

    Erik Brachmann

    2017-11-01

    Full Text Available A highly efficient and reproducible cleaning procedure of piezoelectric substrates is essential in surface acoustic waves (SAW technology to fabricate high-quality SAW devices, especially for new applications such SAW sensors wherein new materials for piezoelectric substrates and interdigital transducers are used. Therefore, the development and critical evaluation of cleaning procedures for each material system that is under consideration becomes crucial. Contaminants like particles or the presence of organic/inorganic material on the substrate can dramatically influence and alter the properties of the thin film substrate composite, such as wettability, film adhesion, film texture, and so on. In this article, focus is given to different cleaning processes like SC-1 and SC-2, UV-ozone treatment, as well as cleaning by first-contact polymer Opticlean, which are applied for removal of contaminants from the piezoelectric substrate Ca 3 TaGa 3 Si 2 O 14 . By means of X-ray photoelectron spectroscopy, the presence of the most critical contaminants such as carbon, sodium, and iron removed through different cleaning procedures were studied and significant differences were observed between the outcomes of these procedures. Based on these results, a two-step cleaning process, combining SC-1 at a reduced temperature at 30 ∘ C instead of 80 ∘ C and a subsequent UV-ozone cleaning directly prior to deposition of the metallization, is suggested to achieve the lowest residual contamination level.

  2. On soil textural classifications and soil-texture-based estimations

    Science.gov (United States)

    Ángel Martín, Miguel; Pachepsky, Yakov A.; García-Gutiérrez, Carlos; Reyes, Miguel

    2018-02-01

    The soil texture representation with the standard textural fraction triplet sand-silt-clay is commonly used to estimate soil properties. The objective of this work was to test the hypothesis that other fraction sizes in the triplets may provide a better representation of soil texture for estimating some soil parameters. We estimated the cumulative particle size distribution and bulk density from an entropy-based representation of the textural triplet with experimental data for 6240 soil samples. The results supported the hypothesis. For example, simulated distributions were not significantly different from the original ones in 25 and 85 % of cases when the sand-silt-clay and very coarse+coarse + medium sand - fine + very fine sand - silt+clay were used, respectively. When the same standard and modified triplets were used to estimate the average bulk density, the coefficients of determination were 0.001 and 0.967, respectively. Overall, the textural triplet selection appears to be application and data specific.

  3. Auditory Perception of Statistically Blurred Sound Textures

    DEFF Research Database (Denmark)

    McWalter, Richard Ian; MacDonald, Ewen; Dau, Torsten

    Sound textures have been identified as a category of sounds which are processed by the peripheral auditory system and captured with running timeaveraged statistics. Although sound textures are temporally homogeneous, they offer a listener with enough information to identify and differentiate...... sources. This experiment investigated the ability of the auditory system to identify statistically blurred sound textures and the perceptual relationship between sound textures. Identification performance of statistically blurred sound textures presented at a fixed blur increased over those presented...

  4. Texture synthesis models and material perception in the visual periphery

    Science.gov (United States)

    Balas, Benjamin

    2015-03-01

    The feature vocabularies used to support texture synthesis algorithms are increasingly being used to examine various aspects of human visual perception. These algorithms offer both a rich set of features that are typically sufficient to capture the appearance of complex natural inputs and a means of carrying out psychophysical experiments using synthetic textures as a proxy for the transformations ostensibly carried out by the visual system when processing natural images using summary statistics. Texture synthesis algorithms have recently been successfully applied to a wide range of visual tasks including texture perception, visual crowding, visual search, among others. Presently, we used both nonparametric and parametric texture synthesis models to investigate the nature of material perception in the visual periphery. We asked participants to classify images of four natural materials (metal, stone, water, and wood) when briefly presented in the visual periphery and compared the errors made under these viewing conditions to the errors made when judging the material category of synthetic images made from the original targets. We found that the confusions made under these two scenarios were substantially different, suggesting that these particular models do not appear to account for material perception in the periphery.

  5. Microstructure and mechanical characteristics of laser coating-texturing alloying dimples

    International Nuclear Information System (INIS)

    Wan Daping; Chen Bingkui; Shao Yimin; Wang Shilong; Hu Dejin

    2008-01-01

    A novel laser coating-texturing (LCT) technique was proposed to achieve appropriate surface topographies and frictional behaviour. The LCT process was realized by applying laser pulses at very high repetition rate to produce innumerable micro-craters with required shape profile on the surface of the workpiece. Moreover, surface alloying of the dimples was carried out by melting submicron WC-TiC-Co alloy powder on the substrates. Morphology and microstructures of the texturing layers were characterised using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Mechanical properties of the textured samples were evaluated by abrasive resistance tests and microhardness measurement. Experimental results show that good fusion bonding between the texturing layers and the substrate has been formed, and the texturing layers are mainly composed of dense and hard fine-grained structures. The abrasive wear resistance of the laser coating-textured surface was 10 times higher than that of the substrates. The average surface microhardness values were as high as 830 HV.

  6. Texture classification using logical operators.

    Science.gov (United States)

    Manian, V; Vasquez, R; Katiyar, P

    2000-01-01

    In this paper, a new algorithm for texture classification based on logical operators is presented. Operators constructed from logical building blocks are convolved with texture images. An optimal set of six operators are selected based on their texture discrimination ability. The responses are then converted to standard deviation matrices computed over a sliding window. Zonal sampling features are computed from these matrices. A feature selection process is applied and the new set of features are used for texture classification. Classification of several natural and synthetic texture images are presented demonstrating the excellent performance of the logical operator method. The computational superiority and classification accuracy of the algorithm is demonstrated by comparison with other popular methods. Experiments with different classifiers and feature normalization are also presented. The Euclidean distance classifier is found to perform best with this algorithm. The algorithm involves only convolutions and simple arithmetic in the various stages which allows faster implementations. The algorithm is applicable to different types of classification problems which is demonstrated by segmentation of remote sensing images, compressed and reconstructed images and industrial images.

  7. Surface texture measurement for additive manufacturing

    International Nuclear Information System (INIS)

    Triantaphyllou, Andrew; Tomita, Ben; Milne, Katherine A; Giusca, Claudiu L; Macaulay, Gavin D; Roerig, Felix; Hoebel, Matthias; Leach, Richard K

    2015-01-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting. (paper)

  8. NiTi intermetallic surface coatings by laser metal deposition for improving wear properties of Ti-6Al-4V substrates

    CSIR Research Space (South Africa)

    Mokgalaka, MN

    2014-03-01

    Full Text Available The NiTi intermetallic possesses a number of good properties, such as high wear, oxidation, and corrosion resistance. This paper focuses on the deposition of NiTi intermetallic coatings on Ti6Al4V substrate by laser melting of Ti and Ni elemental...

  9. Di-uniform texture spaces

    Directory of Open Access Journals (Sweden)

    Selma Ozcag

    2003-04-01

    Full Text Available Textures were introduced by the second author as a point-based setting for the study of fuzzy sets, and have since proved to be an appropriate framework for the development of complement-free mathematical concepts. In this paper the authors lay the foundation for a theory of uniformities in a textural context. Analogues are given for both the diagonal and covering approaches to the classical theory of uniform structures, the notion of uniform topology is generalized and an analogue given for the well known result that a topological space is uniformizable if and only if it is completely regular. Finally a textural analogue of the classical interplay between uniformities and families of pseudo-metrics is presented.

  10. BREAD CRUMBS TEXTURE OF SPELT

    Directory of Open Access Journals (Sweden)

    Joanna Korczyk – Szabó

    2014-02-01

    Full Text Available Texture analysis is an objective physical examination of baked products and gives direct information on the product quality, oppositely to dough rheology tests what inform on the baking suitability of the flour, as raw material. Evaluation of the mechanical properties of bread crumb is important not only for quality assurance in the bakeries, but also for assessing the effects of changes in dough ingredients and processing condition and also for describing the changes in bread crumb during storage. Crumb cellular structure is an important quality criterion used in commercial baking and research laboratories to judge bread quality alongside taste, crumb colour and crumb physical texture. In the framework of our research during the years 2010 – 2011 were analyzed selected indicators of bread crumb for texture quality of three Triticum spelta L. cultivars – Altgold, Rubiota and Ostro grown in an ecological system. The bread texture quality was evaluated on texture analyzer TA.XT Plus (Stable Micro Systems, Surrey, UK, following the AACC (74-09 standard and expressed as crumb firmness (N, stiffness (N.mm-1 and relative elasticity (%. Our research proved that all selected indicators were significantly influenced by the year of growing and variety. The most soft bread was achieved in Rubiota, whereas bread crumb samples from Altgold and Ostro were the most firm and stiff. Correlation analysis showed strong negative correlation between relative elasticity and bread crumb firmness as well as bread stiffness (-0.65++, -0.66++. The spelt wheat bread crumb texture need further investigation as it can be a reliable quality parameter.

  11. A novel approach using powder metallurgy for strengthened RABiTS composite substrates for coated superconductors

    International Nuclear Information System (INIS)

    Suo Hongli; Zhao Yue; Liu Min; Ye Shuai; Zhu YongHua; He Dong; Ma Lingji; Ji Yuan; Zhou Meiling

    2008-01-01

    We report on the development of mechanically strengthened, highly textured Ni-5 at.%W/Ni-12 at.%W composite materials prepared by a powder metallurgical approach as promising weakly magnetic substrates for coated superconductors. The key configuration of this composite substrate consists of a thin, sharp cubic textured Ni-5 at.%W layer on a Ni-12 at.%W alloy core, thus providing a mechanical reinforcement while decreasing the saturation magnetization of the whole substrate. The composite substrates have a sharp cubic texture at the top Ni-5 at.%W outer layer and their yield strength reaches 272 MPa, exceeding that of the commercially used Ni5W substrates by a factor of 1.6. The saturation magnetization of the composite substrate Ni5W/Ni12W/Ni5W is substantially reduced when compared to that of pure Ni and Ni-5 at.%W substrates, respectively

  12. Metallic nanomesh

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhifeng; Sun, Tianyi; Guo, Chuanfei

    2018-02-20

    A transparent flexible nanomesh having at least one conductive element and sheet resistance less than 300.OMEGA./.quadrature. when stretched to a strain of 200% in at least one direction. The nanomesh is formed by depositing a sacrificial film, depositing, etching, and oxidizing a first metal layer on the film, etching the sacrificial film, depositing a second metal layer, and removing the first metal layer to form a nanomesh on the substrate.

  13. Quantitative determination of wear metals in engine oils using LIBS: The use of paper substrates and a comparison between single- and double-pulse LIBS

    International Nuclear Information System (INIS)

    A comparison between single- and double-pulse LIBS for the quantitative elemental analysis of used engine oils has been performed. Paper substrates have been utilised for the analysis and are shown to provide better limits of detection (LODs), no splashing and easier sample handling compared to the previously reported experiments using laminar liquid jets and static liquid surfaces. Single-pulse LIBS analysis of oil on paper substrates has had on average 2x better LODs than was obtained using flowing liquid jets, while double-pulse LIBS showed 4x improvement. Single-pulse LIBS has been found preferable for the analysis, as the use of an additional laser in double-pulse LIBS yielded only a minor improvement while adding substantially to the complexity and cost of the system

  14. Effect of maleic anhydride-aniline derivative buffer layer on the properties of flexible substrate heterostructures: Indium tin oxide/nucleic acid base/metal

    Energy Technology Data Exchange (ETDEWEB)

    Stanculescu, A., E-mail: sanca@infim.ro [National Institute of Materials Physics, 105 bis Atomistilor Street, P.O. Box MG-7, 077125, Bucharest-Magurele (Romania); Socol, M. [National Institute of Materials Physics, 105 bis Atomistilor Street, P.O. Box MG-7, 077125, Bucharest-Magurele (Romania); Socol, G.; Mihailescu, I.N. [National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG-36, 077125, Bucharest-Magurele (Romania); Girtan, M. [Laboratoire de Photonique d' Angers, Universite d' Angers, 2, Bd. Lavoisier, 49045, Angers (France); Preda, N. [National Institute of Materials Physics, 105 bis Atomistilor Street, P.O. Box MG-7, 077125, Bucharest-Magurele (Romania); Albu, A.-M. [Department of Polymer Science, University ' Politehnica' of Bucharest, Bucharest (Romania); Stanculescu, F. [University of Bucharest, Faculty of Physics, Str. Atomistilor nr.405, P.O. Box MG-11, Bucharest-Magurele, 077125 (Romania)

    2011-12-01

    This paper presents some investigations on the properties of guanine (G) and cytosine (C) based heterostructures deposited on flexible substrates. The effects of two types of maleic anhydride-aniline derivatives (maleic anhydride-cyano aniline or maleic anhydride-2,4 dinitroaniline) buffer layer, deposited between indium tin oxide and (G) or (C) layer, on the optical and electrical properties of the heterostructures have been identified. The heterostructures containing a film of maleic anhydride-2,4 dinitroaniline have shown a good transparency and low photoluminescence in visible range. This buffer layer has determined an increase in the conductance only in the heterostructures based on (G) and (C) deposited on biaxially-oriented polyethylene terephthalate substrate.

  15. Probing the effect of charge transfer enhancement in off resonance mode SERS via conjugation of the probe dye between silver nanoparticles and metal substrates.

    Science.gov (United States)

    Selvakannan, Pr; Ramanathan, Rajesh; Plowman, Blake J; Sabri, Ylias M; Daima, Hemant K; O'Mullane, Anthony P; Bansal, Vipul; Bhargava, Suresh K

    2013-08-21

    The charge transfer-mediated surface enhanced Raman scattering (SERS) of crystal violet (CV) molecules that were chemically conjugated between partially polarized silver nanoparticles and optically smooth gold and silver substrates has been studied under off-resonant conditions. Tyrosine molecules were used as a reducing agent to convert silver ions into silver nanoparticles where oxidised tyrosine caps the silver nanoparticle surface with its semiquinone group. This binding through the quinone group facilitates charge transfer and results in partially oxidised silver. This establishes a chemical link between the silver nanoparticles and the CV molecules, where the positively charged central carbon of CV molecules can bind to the terminal carboxylate anion of the oxidised tyrosine molecules. After drop casting Ag nanoparticles bound with CV molecules it was found that the free terminal amine groups tend to bind with the underlying substrates. Significantly, only those CV molecules that were chemically conjugated between the partially polarised silver nanoparticles and the underlying gold or silver substrates were found to show SERS under off-resonant conditions. The importance of partial charge transfer at the nanoparticle/capping agent interface and the resultant conjugation of CV molecules to off resonant SERS effects was confirmed by using gold nanoparticles prepared in a similar manner. In this case the capping agent binds to the nanoparticle through the amine group which does not facilitate charge transfer from the gold nanoparticle and under these conditions SERS enhancement in the sandwich configuration was not observed.

  16. Charge transfer from an adsorbed ruthenium-based photosensitizer through an ultra-thin aluminium oxide layer and into a metallic substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Andrew J.; Temperton, Robert H.; Handrup, Karsten; Weston, Matthew; Mayor, Louise C.; O’Shea, James N., E-mail: james.oshea@nottingham.ac.uk [School of Physics and Astronomy and Nottingham Nanotechnology and Nanoscience Centre (NNNC), University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2014-06-21

    The interaction of the dye molecule N3 (cis-bis(isothiocyanato)bis(2,2-bipyridyl-4,4′-dicarbo-xylato) -ruthenium(II)) with the ultra-thin oxide layer on a AlNi(110) substrate, has been studied using synchrotron radiation based photoelectron spectroscopy, resonant photoemission spectroscopy, and near edge X-ray absorption fine structure spectroscopy. Calibrated X-ray absorption and valence band spectra of the monolayer and multilayer coverages reveal that charge transfer is possible from the molecule to the AlNi(110) substrate via tunnelling through the ultra-thin oxide layer and into the conduction band edge of the substrate. This charge transfer mechanism is possible from the LUMO+2 and 3 in the excited state but not from the LUMO, therefore enabling core-hole clock analysis, which gives an upper limit of 6.0 ± 2.5 fs for the transfer time. This indicates that ultra-thin oxide layers are a viable material for use in dye-sensitized solar cells, which may lead to reduced recombination effects and improved efficiencies of future devices.

  17. Block Textured a-Si:H Solar Cell

    Directory of Open Access Journals (Sweden)

    Seung Jae Moon

    2014-01-01

    Full Text Available A series of etching experiments on light trapping structure have been carried out by glass etching. The block structure provides long light traveling path and a constant distance between the cathode and anode electrodes regardless of the block height, which results in higher efficiency of the block textured solar cell. In terms of etching profile of the glass substrate, the addition of NH4F resulted in the smooth and clean etching profile, and the steep slope of the block was obtained by optimizing the composition of etching solution. For a higher HF concentration, a more graded slope was obtained and the addition of HNO3 and NH4F provided steep slope and clean etching profile. The effects of the block textured glass were verified by a comparison of the solar cell efficiency. For the textured solar cell, the surface was much rougher than that of the plain glass, which also contributes to the improvement of the efficiency. We accomplished block shaped light trapping structure for the first time by wet etching of the glass substrate, which enables the high efficiency thin film solar cell with the aid of the good step coverage deposition.

  18. Structural and morphological characterizations of ZnO films grown on GaAs substrates by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Agouram, S.; Zuniga Perez, J.; Munoz-Sanjose, V. [Universitat de Valencia, Departamento de Fisica Aplicada y Electromagnetismo, Burjassot (Spain)

    2007-07-15

    ZnO films were grown on GaAs(100), GaAs(111)A and GaAs(111)B substrates by metal organic chemical vapour deposition (MOCVD). Diethylzinc (DEZn) and tertiarybutanol (t-butanol) were used as Zn and O precursors, respectively. The influence of the growth temperature and GaAs substrate orientation on the crystalline orientation and morphology of the ZnO grown films has been analysed. Crystallinity of grown films was studied by X-ray diffraction (XRD); thickness and morphology of ZnO films were investigated by scanning electron microscopy (SEM). SEM results reveal significant differences between morphologies depending on growth temperature but not significant differences were detected on the texture of grown films. (orig.)

  19. Height and Tilt Geometric Texture

    DEFF Research Database (Denmark)

    Andersen, Vedrana; Desbrun, Mathieu; Bærentzen, Jakob Andreas

    2009-01-01

    compromise between functionality and simplicity: it can efficiently handle and process geometric texture too complex to be represented as a height field, without having recourse to full blown mesh editing algorithms. The height-and-tilt representation proposed here is fully intrinsic to the mesh, making...

  20. Texture analysis using Gabor wavelets

    Science.gov (United States)

    Naghdy, Golshah A.; Wang, Jian; Ogunbona, Philip O.

    1996-04-01

    Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for texture classification. The 'rosette' spans 360 degrees of orientation and covers frequencies from dc. In the proposed algorithm, the texture images are decomposed by the Gabor wavelet configuration and the feature vectors corresponding to the mean of the outputs of the multi-channel filters extracted. A minimum distance classifier is used in the classification procedure. As a comparison the Gabor filter has been used to classify the same texture images from the Brodatz album and the results indicate the superior discriminatory characteristics of the Gabor wavelet. With the test images used it can be concluded that the Gabor wavelet model is a better approximation of the cortical cell receptive field profiles.

  1. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Köster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19-60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  2. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, van T.

    2010-01-01

    The perception of complex textures in food is strongly related to the way food is processed during eating, and is modulated by other basic characteristics, such as taste and aroma. An understanding at the colloidal level of the basic processes in the mouth is essential in order to link the

  3. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Koster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19¿60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  4. Euromet Comparison on Surface Texture

    DEFF Research Database (Denmark)

    Koenders, L.; Andreasen, Jan Lasson; De Chiffre, Leonardo

    2004-01-01

    In the region of EUROMET, we performed from 2001 to 2003 a comparison covering a number among the most interesting parameters in the field of surface texture, i.e. Pt, D, Ra, Rz, RSm, and the Rk-parameters. 16 institutes carried out measurements on typical roughness standards as described in ISO...

  5. Texture of lipid bilayer domains

    DEFF Research Database (Denmark)

    Jensen, Uffe Bernchou; Brewer, Jonathan R.; Midtiby, Henrik Skov

    2009-01-01

    We investigate the texture of gel (g) domains in binary lipid membranes composed of the phospholipids DPPC and DOPC. Lateral organization of lipid bilayer membranes is a topic of fundamental and biological importance. Whereas questions related to size and composition of fluid membrane domain...

  6. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, T. van; Aken, G.A. van; Jongh, H.H.J. de; Hamer, R.J.

    2009-01-01

    Recently, considerable attention has been given to the understanding of texture attributes that cannot directly be related to physical properties of food, such as creamy, crumbly and watery. The perception of these attributes is strongly related to the way the food is processed during food intake,

  7. Extending ultra-short pulse laser texturing over large area

    Energy Technology Data Exchange (ETDEWEB)

    Mincuzzi, G., E-mail: girolamo.mincuzzi@alphanov.com; Gemini, L.; Faucon, M.; Kling, R.

    2016-11-15

    Highlights: • We carried out metal surface texturing (Ripples, micro grooves, Spikes) using a high power, high repetition rate, industrial, Ultra-short pulses laser. • Extremely Fast processing is shown (Laser Scan speed as high as 90 m/s) with a polygon scanner head. • Stainless steel surface blackening with Ultra-short pulses laser has been obtained with unprecedented scanspeed. • Full SEM surface characterization was carried out for all the different structures obtained. • Reflectance measurements were carried out to characterize surface reflectance. - Abstract: Surface texturing by Ultra-Short Pulses Laser (UPL) for industrial applications passes through the use of both fast beam scanning systems and high repetition rate, high average power P, UPL. Nevertheless unwanted thermal effects are expected when P exceeds some tens of W. An interesting strategy for a reliable heat management would consists in texturing with a low fluence values (slightly higher than the ablation threshold) and utilising a Polygon Scanner Heads delivering laser pulses with unrepeated speed. Here we show for the first time that with relatively low fluence it is possible over stainless steel, to obtain surface texturing by utilising a 2 MHz femtosecond laser jointly with a polygonal scanner head in a relatively low fluence regime (0.11 J cm{sup −2}). Different surface textures (Ripples, micro grooves and spikes) can be obtained varying the scan speed from 90 m s{sup −1} to 25 m s{sup −1}. In particular, spikes formation process has been shown and optimised at 25 m s{sup −1} and a full morphology characterization by SEM has been carried out. Reflectance measurements with integrating sphere are presented to compare reference surface with high scan rate textures. In the best case we show a black surface with reflectance value < 5%.

  8. Feature-aware natural texture synthesis

    KAUST Repository

    Wu, Fuzhang

    2014-12-04

    This article presents a framework for natural texture synthesis and processing. This framework is motivated by the observation that given examples captured in natural scene, texture synthesis addresses a critical problem, namely, that synthesis quality can be affected adversely if the texture elements in an example display spatially varied patterns, such as perspective distortion, the composition of different sub-textures, and variations in global color pattern as a result of complex illumination. This issue is common in natural textures and is a fundamental challenge for previously developed methods. Thus, we address it from a feature point of view and propose a feature-aware approach to synthesize natural textures. The synthesis process is guided by a feature map that represents the visual characteristics of the input texture. Moreover, we present a novel adaptive initialization algorithm that can effectively avoid the repeat and verbatim copying artifacts. Our approach improves texture synthesis in many images that cannot be handled effectively with traditional technologies.

  9. Surface Hydrophilicity and Antifungal Properties of TiO2 Films Coated on a Co-Cr Substrate

    Directory of Open Access Journals (Sweden)

    Lijuan Huang

    2017-01-01

    Full Text Available The purpose of this study was to deposit a thin layer of TiO2 on a Co-Cr substrate, serving as a deactivation film protecting the metallic fitting surface. The crystalline structure and surface morphology of the film were characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM. A scratch tester was used to examine the adhesion strength between the TiO2 film and the Co-Cr substrate. The water contact angles and antifungal efficacy against C. albicans of the TiO2-deposited Co-Cr samples were investigated and further compared with those of uncoated Co-Cr substrates. The results indicated that a pure anatase microstructure and dense and smooth surface texture as well as strong binding to the underlying metallic surface were obtained. The originally hydrophobic Co-Cr alloy surface turned hydrophilic after TiO2 film coating. Most importantly, the TiO2-coated surface showed a superior antifungal capability under UV-irradiation compared to those without TiO2 coating. This work contains meaningful results for the development of a new metallic framework coating with improved hydrophilicity and antifungal properties.

  10. The Influence of Tool Texture on Friction and Lubrication in Strip Reduction Testing

    DEFF Research Database (Denmark)

    Sulaiman, Mohd Hafis Bin; Christiansen, Peter; Bay, Niels Oluf

    2017-01-01

    While texturing of workpiece surfaces to promote lubrication in metal forming has beenapplied for several decades, tool surface texturing is rather new. In the present paper, tool texturing is studied as a method to prevent galling. A strip reduction test was conducted with tools provided...... the pocket width. Larger drawing speed facilitates escape of the entrapped lubricant in the pockets. Testing with low-to-medium viscosity oils leads to a low sheet roughness on the plateaus, but also local workpiece material pick-up on the tool plateaus. Large lubricant viscosity results in higher sheet...

  11. A multi-resolution texture fusion algorithm

    Science.gov (United States)

    Li, Yu Qin; Zhou, Xiang; Guo, Jia Yu; Yang, Tao; Fei, Zi Xuan

    2017-09-01

    Texture fusion is essential for three-dimensional photo-realistic texture model reconstruction. Multi-resolution texture fusion mainly is applied to reconstruct three-dimensional models that the local texture is very realistic. This paper presents a multi-resolution texture fusion algorithm based on digital image processing. The technique utilizes the depth camera to obtain range data and the texture camera to obtain the local interested high-resolution texture of the object. And each point of the range images a pixel of the picture corresponding to this view should be found, so the map between high-resolution texture and local three-dimensional points could be obtained by calibrating texture camera and depth camera to register the local high-resolution texture with the low resolution texture collected by the depth camera or calibrating texture camera and depth camera. ICP is applied to register models, and mapping different-resolution textures onto three-dimensional models. Then the light source correction of textures is applied to remove the systematic differences such as lighting change which are achieved by computing linear regression correction mode. Finally, the global correction is applied to refine the observable variations in color that may still exist near the fusion boundaries. These corrections will utilize the grid triangle vertex color as a constraint to drive texture fusion to remove discontinuities from different resolutions. The advantage of this technique is that it utilizes the light source correction and global correction to fuse different resolutions textures. Experiments with this technique indicate that it significantly corrects the observable discontinuities within the overlapping areas, which are given from different resolutions, lighting change, non-lambertian object surface, etc.

  12. Texture analysis using Renyi's generalized entropies

    NARCIS (Netherlands)

    Grigorescu, SE; Petkov, N

    2003-01-01

    We propose a texture analysis method based on Renyi's generalized entropies. The method aims at identifying texels in regular textures by searching for the smallest window through which the minimum number of different visual patterns is observed when moving the window over a given texture. The

  13. Real-time Texture Error Detection

    Directory of Open Access Journals (Sweden)

    Dan Laurentiu Lacrama

    2008-01-01

    Full Text Available This paper advocates an improved solution for the real-time error detection of texture errors that occurs in the production process in textile industry. The research is focused on the mono-color products with 3D texture model (Jacquard fabrics. This is a more difficult task than, for example, 2D multicolor textures.

  14. Evaluation of color representation for texture analysis

    NARCIS (Netherlands)

    Verbrugge, R.; van den Broek, Egon; van Rikxoort, E.M.; Taatgen, N.; Schomaker, L.

    2004-01-01

    Since more than 50 years texture in image material is a topic of research. Hereby, color was ignored mostly. This study compares 70 different configurations for texture analysis, using four features. For the configurations we used: (i) a gray value texture descriptor: the co-occurrence matrix and a

  15. Texture Control: Theoretical and Practical Study

    DEFF Research Database (Denmark)

    Leffers, Torben; Gangli, P.

    1978-01-01

    The possibility of controlling the rolling texture by simple modifications to the rolling process is investigated. It is demonstrated that the computer programs developed for simulation of the normal rolling textures can also satisfactorily predict textures formed under new rolling conditions...

  16. Bi axially textured YBCO coated tape prepared using dynamic magnetic grain alignment

    International Nuclear Information System (INIS)

    Genoud, Jean-Yves; Quinton, William

    1999-01-01

    A new magnetic grain alignment technique has been applied to produce bi axially aligned YBCO coated tapes. A bi axially aligned dispersion of orthorhombic Y 2 Ba 4 Cu 7 O 15 (Y-247) powder was settled on un textured silver substrates. The Y-247 tapes were then melt processed to achieve high critical current YBa 2 Cu 3 O 7 (Y-123) tapes with CuO as a secondary phase. The biaxial alignment is preserved after the densification process and a clear enhancement of J c relative to identically prepared un textured or uniaxially textured samples is obtained. Critical current densities of up to 5000 A cm -2 at 77 K in self-field and 1500 A cm -2 in 0.5 T magnetic field at 65 K were obtained in films from 20 to 40 μm thick. Problems were experienced in achieving fully densified thick films while retaining biaxial texture. The initial grain size distribution was found to have a major influence on the final microstructure. Provided significant improvements in J c can be obtained this method offers an alternative to coated tape processes based on epitaxial growth which has the advantage that it does not require textured substrates. The biaxial alignment technique described here intrinsically acts on the bulk material rather than at surfaces. This offers the possibility of texturing without thickness limitations. (author)

  17. Magnetic properties of the melt-textured (Nd,Eu,Gd)Ba.sub.2./sub.Cu.sub.3./sub.O.sub.y./sub. superconductors doped by nanoparticles of refractory metals

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Muralidhar, M.; Rameš, Michal

    2012-01-01

    Roč. 36, č. 2012 (2012), s. 453-457 ISSN 1875-3892 R&D Projects: GA MŠk(CZ) ME10069 Institutional research plan: CEZ:AV0Z10100520 Keywords : bulk cuprates * NEG-123 * vortex pinning * nanoparticle doping * refactory metal oxide doping Subject RIV: BM - Solid Matter Physics ; Magnetism

  18. Effect of Glomus intraradices isolated from Pb-contaninated soil on Pb uptake by Agrostis capillaris is changed by its cultivation i a metal-free substrate

    Czech Academy of Sciences Publication Activity Database

    Rydlová, Jana; Vosátka, Miroslav

    2003-01-01

    Roč. 38, - (2003), s. 155-165 ISSN 0015-5551 R&D Projects: GA AV ČR KSK6005114; GA MŠk OC 838.10; GA ČR GA526/99/P032; GA ČR GA526/99/0895 Institutional research plan: CEZ:AV0Z6005908 Keywords : arbuscular mycorrhizal fungi * heavy metal tolerance * lead contamination Subject RIV: EF - Botanics Impact factor: 1.057, year: 2003

  19. Metal insulator semiconductor solar cell devices based on a Cu2O substrate utilizing h-BN as an insulating and passivating layer

    International Nuclear Information System (INIS)

    Ergen, Onur; Gibb, Ashley; Vazquez-Mena, Oscar; Zettl, Alex; Regan, William Raymond

    2015-01-01

    We demonstrate cuprous oxide (Cu 2 O) based metal insulator semiconductor Schottky (MIS-Schottky) solar cells with efficiency exceeding 3%. A unique direct growth technique is employed in the fabrication, and hexagonal boron nitride (h-BN) serves simultaneously as a passivation and insulation layer on the active Cu 2 O layer. The devices are the most efficient of any Cu 2 O based MIS-Schottky solar cells reported to date

  20. Electro-deposition metallic tungsten coatings in a Na{sub 2}WO{sub 4}-WO{sub 3} melt on copper based alloy substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.H., E-mail: dreamerhong77@126.com [School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang, Y.C.; Liu, Q.Z.; Li, X.L.; Jiang, F. [School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The tungsten coating (>1 mm) was obtained by electro-deposition method in molten salt. Black-Right-Pointing-Pointer Different thickness tungsten coatings were obtained by using different durations. Black-Right-Pointing-Pointer Good performance of coating was obtained when pulse parameters were modulated. - Abstract: The tungsten coating was prepared by electro-deposition technique on copper alloy substrate in a Na{sub 2}WO{sub 4}-WO{sub 3} melt. The coating's surface and cross-section morphologies as well as its impurities were investigated by XPS, SEM and line analysis. Various plating durations were investigated in order to obtain an optimal coating's thickness. The results demonstrated that the electro-deposited coating was compact, voidless, crackless and free from impurities. The tungsten coating's maximum Vickers hardness was measured to be 520 HV. The tungsten coating's minimum oxygen content was determined to be 0.018 wt%. Its maximum thickness was measured to be 1043.67 {mu}m when the duration of electrolysis was set to 100 h. The result of this study has demonstrated the feasibility of having thicker tungsten coatings on copper alloy substrates. These electrodeposited tungsten coatings can be potentially implemented as reliable armour for the medium heat flux plasma facing component (PFC).

  1. Effect of Metal Chelators on γ-Secretase Indicates That Calcium and Magnesium Ions Facilitate Cleavage of Alzheimer Amyloid Precursor Substrate

    Directory of Open Access Journals (Sweden)

    Michael Ho

    2011-01-01

    Full Text Available Gamma-secretase is involved in the production of Aβ amyloid peptides. It cleaves the transmembrane domain of the amyloid precursor protein (APP at alternative sites to produce Aβ and the APP intracellular domain (AICD. Metal ions play an important role in Aβ aggregation and metabolism, thus metal chelators and ligands represent potential therapeutic agents for AD treatment. A direct effect of metal chelators on γ-secretase has not yet been investigated. The authors used an in vitro  γ-secretase assay consisting of cleavage of APP C100-3XFLAG by endogenous γ-secretase from rodent brains and human neuroblastoma SH-SY5Y, and detected AICD production by western blotting. Adding metalloprotease inhibitors to the reaction showed that clioquinol, phosphoramidon, and zinc metalloprotease inhibitors had no significant effect on γ-secretase activity. In contrast, phenanthroline, EDTA, and EGTA markedly decreased γ-secretase activity that could be restored by adding back calcium and magnesium ions. Mg2+ stabilized a 1,000 kDa presenilin 1 complex through blue native gel electrophoresis and size-exclusion chromatography. Data suggest that Ca2+ and Mg2+ stabilize γ-secretase and enhance its activity.

  2. Adjoint-based optimization of mechanical performance in polycrystalline materials and structures through texture control

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Grace [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bishop, Joseph E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The texture of a polycrystalline material refers to the preferred orientation of the grains within the material. In metallic materials, texture can significantly affect the mechanical properties such as elastic moduli, yield stress, strain hardening, and fracture toughness. Recent advances in additive manufacturing of metallic materials offer the possibility in the not too distant future of controlling the spatial variation of texture. In this work, we investigate the advantages, in terms of mechanical performance, of allowing the texture to vary spatially. We use an adjoint-based gradient optimization algorithm within a finite element solver (COMSOL) to optimize several engineering quantities of interest in a simple structure (hole in a plate) and loading (uniaxial tension) condition. As a first step to general texture optimization, we consider the idealized case of a pure fiber texture in which the homogenized properties are transversely isotropic. In this special case, the only spatially varying design variables are the three Euler angles that prescribe the orientation of the homogenized material at each point within the structure. This work paves a new way to design metallic materials for tunable mechanical properties at the microstructure level.

  3. Imparting Icephobicity with Substrate Flexibility

    Science.gov (United States)

    Schutzius, Thomas; Vasileiou, Thomas; Poulikakos, Dimos

    2017-11-01

    Ice accumulation poses serious safety and performance issues for modern infrastructure. Rationally designed superhydrophobic surfaces have demonstrated potential as a passive means to mitigate ice accretion; however, further studies on solutions that reduce impalement and contact time for impacting supercooled droplets are urgently needed. Here we demonstrate the collaborative effect of substrate flexibility and surface texture on enhancing icephobicity and repelling viscous droplets. We first investigate the influence of increased viscosity on impalement resistance and droplet-substrate contact time. Then we examine the effect of droplet partial solidification on recoil by impacting supercooled water droplets onto surfaces containing ice nucleation promoters. We demonstrate a passive method for shedding partially solidified droplets that does not rely on the classic recoil mechanism. Using an energy-based model, we identify a previously unexplored mechanism whereby the substrate oscillation governs the rebound process by efficiently absorbing the droplet kinetic energy and rectifying it back, allowing for droplet recoil. This mechanism applies for a range of droplet viscosities and ice slurries, which do not rebound from rigid superhydrophobic substrates. Partial support of the Swiss National Science Foundation under Grant No. 162565 and the European Research Council under Advanced Grant No. 669908 (INTICE) is acknowledged.

  4. Post annealing effect on transport properties of La0.67Ca0.33MnO3 films grown on vicinal cut substrates

    International Nuclear Information System (INIS)

    Yu, L.; Wang, Y.; Li, H.S.; Liu, X.; Zhang, P.X.

    2011-01-01

    Highlights: → Epitaxial La 0.67 Ca 0.33 MnO 3 thin films grown on vicinal cut substrate. → The metal-insulator transition temperature shows large enhancement about 20-30 K towards higher temperature after post annealing. → Film on 10 o vicinal cut substrate has a metal-insulator transition temperature of 291.4 K. - Abstract: La 0.67 Ca 0.33 MnO 3 thin films have been grown on 10 o , 15 o , and 20 o vicinal cut SrTiO 3 (1 0 0) substrates by pulse laser deposition. The single phase and the least textured growth have been studied by X-ray diffraction analysis. The post annealing effect with high temperature and high oxygen pressure on the transport properties of films has been investigated by resistance versus temperature measurements. Films with post annealing show large enhancement of metal-insulator transition temperature T p about 20-30 K towards higher temperature and obvious decrease of resistance, which is attributed to the refilling of oxygen, the change of Mn-O-Mn angle and the improvement of crystallinity by the post annealing effect. Specially, film on 20 o vicinal cut substrate exhibits the biggest range gap of peak resistance drop, which may originate from more defects caused by steps at this tilt angle and many of these defects are removed after post annealing.

  5. Room temperature growth of biaxially aligned yttria-stabilized zirconia films on glass substrates by pulsed-laser deposition

    CERN Document Server

    Li Peng; Mazumder, J

    2003-01-01

    Room temperature deposition of biaxially textured yttria-stabilized zirconia (YSZ) films on amorphous glass substrates was successfully achieved by conventional pulsed-laser deposition. The influence of the surrounding gases, their pressure and the deposition time on the structure of the films was studied. A columnar growth process was revealed based on the experimental results. The grown biaxial texture appears as a kind of substrate independence, which makes it possible to fabricate in-plane aligned YSZ films on various substrates.

  6. Watermarking textures in video games

    Science.gov (United States)

    Liu, Huajian; Berchtold, Waldemar; Schäfer, Marcel; Lieb, Patrick; Steinebach, Martin

    2014-02-01

    Digital watermarking is a promising solution to video game piracy. In this paper, based on the analysis of special challenges and requirements in terms of watermarking textures in video games, a novel watermarking scheme for DDS textures in video games is proposed. To meet the performance requirements in video game applications, the proposed algorithm embeds the watermark message directly in the compressed stream in DDS files and can be straightforwardly applied in watermark container technique for real-time embedding. Furthermore, the embedding approach achieves high watermark payload to handle collusion secure fingerprinting codes with extreme length. Hence, the scheme is resistant to collusion attacks, which is indispensable in video game applications. The proposed scheme is evaluated in aspects of transparency, robustness, security and performance. Especially, in addition to classical objective evaluation, the visual quality and playing experience of watermarked games is assessed subjectively in game playing.

  7. Growing Periandra mediterranea on post-mining substrate: native Fabaceae with potential for revegetation of degraded rupestrian grasslands in Brazil

    Directory of Open Access Journals (Sweden)

    Maurilio Assis Figueiredo

    2018-01-01

    Full Text Available ABSTRACT Recovery of degraded areas of rupestrian grasslands is hampered mainly by the limited knowledge regarding substrate management and the biology of native species suitable for revegetation of these areas. The aim of our study was to examine the establishment and growth of Periandra mediterranea in different textures of lateritic substrate from a mining-degraded area. The growth of P. mediterranea was evaluated using fine and coarse laterite, both with and without the addition of topsoil. Survival, dry biomass, content of chemical elements and nodulation were evaluated in ten individuals per treatment sixteen months after planting. Although the substrate has low nutrient content, yet high metal concentrations, all plants survived. Plants growing on coarse laterite had 140 % greater biomass than those growing on fine laterite. The addition of topsoil increased biomass in coarse and fine laterite by 46 and 151 %, respectively, and doubled the number of nodulated plants, regardless of grain size. The biomass accumulation of P. mediterranea to a dystrophic substrate revealed its potential for use in the revegetation of degraded areas of rupestrian grasslands. Furthermore, the addition of topsoil facilitated the association of P. mediterranea with nitrogen-fixing bacteria, and increased its growth and capacity to improve substrate fertility.

  8. Nanomechanical and Macrotribological Properties of CVD-Grown Graphene as a Middle Layer between Metal Pt Cylinders and SiO2/Si Substrate

    Directory of Open Access Journals (Sweden)

    Hongyan Wu

    2015-01-01

    Full Text Available The CVD-grown graphene as a middle layer was introduced between Pt cylinders and SiO2/Si to extend the application of graphene for improving the wear performance of microelectromechanical systems. Periodic arrays of Pt cylinders were prepared on the graphene/SiO2/Si (Pt/graphene and SiO2/Si substrate (Pt/SiO2 using the magnetron sputtering technique. To characterize Pt/graphene and Pt/SiO2, nanoindentation and macrotribological tests were performed. The results showed that the friction coefficient was lower and the wear lifetime of Pt/graphene was longer than those of Pt/SiO2. Graphene, as a middle layer, was not only observed to have significant influence on the mechanical properties (i.e., microhardness and elastic modulus, but also found to improve the adhesive strength between SiO2/Si and Pt cylinders.

  9. Comparative Study of the Optical and Textural Properties of Tetrapyrrole Macrocycles Trapped Within ZrO2, TiO2, and SiO2 Translucent Xerogels

    Directory of Open Access Journals (Sweden)

    Eduardo Salas-Bañales

    2015-10-01

    Full Text Available The entrapping of physicochemical active molecules inside mesoporous networks is an appealing field of research due to the myriad of potential applications in optics, photocatalysis, chemical sensing, and medicine. One of the most important reasons for this success is the possibility of optimizing the properties that a free active species displays in solution but now trapped inside a solid substrate. Additionally it is possible to modulate the textural characteristics of substrates, such as pore size, specific surface area, polarity and chemical affinity of the surface, toward the physical or chemical adhesion of a variety of adsorbates. In the present document, two kinds of non-silicon metal alkoxides, Zr and Ti, are employed to prepare xerogels containing entrapped tetrapyrrolic species that could be inserted beforehand in analogue silica systems. The main goal is to develop efficient methods for trapping or binding tetrapyrrole macrocycles inside TiO2 and ZrO2 xerogels, while comparing the properties of these systems against those of the SiO2 analogues. Once the optimal synthesis conditions for obtaining translucent monolithic xerogels of ZrO2 and TiO2 networks were determined, it was confirmed that these substrates allowed the entrapment, in monomeric form, of macrocycles that commonly appear as aggregates within the SiO2 network. From these experiments, it could be determined that the average pore diameters, specific surface areas, and water sorption capacities depicted by each one of these substrates, are a consequence of their own nature combined with the particular structure of the entrapped tetrapyrrole macrocycle. Furthermore, the establishment of covalent bonds between the intruding species and the pore walls leads to the obtainment of very similar pore sizes in the three different metal oxide (Ti, Zr, and Si substrates as a consequence of the templating effect of the encapsulated species.

  10. Oblique ion texturing of yttria-stabilized zirconia: the {211} structure

    International Nuclear Information System (INIS)

    Berdahl, Paul; Reade, Ronald P.; Liu, Jinping; Russo, Richard E.; Fritzemeier, Les; Buczek, David; Schoop, Urs

    2003-01-01

    Amorphous (Zr,Y)O x films were synthesized by reactive magnetron sputtering and subsequently crystallized by oblique ion bombardment. Crystalline texture nucleated by the ion beam was replicated by solid-phase epitaxial growth throughout the formerly amorphous yttria-stabilized zirconia (YSZ) film. The resulting YSZ films have (211) orientation normal to the substrate with in-plane directions (111), parallel, and (110), transverse, to the azimuth of the ion beam. We hypothesize that the texture mechanism involves ion-induced film compression and shear. The results, taken together with prior work, show that oblique ion texturing of amorphous films is a general phenomenon that can be used to fabricate substrates with more than one type of crystallographic orientation

  11. Oblique ion texturing of yttria-stabilized zirconia: The {211} structure

    International Nuclear Information System (INIS)

    Berdahl, Paul; Reade, Ronald P.; Liu, Jinping; Russo, Richard E.; Fritzemeier, Les; Buczek, David; Schoop, Urs

    2002-01-01

    Amorphous (Zr,Y)O x films were synthesized by reactive magnetron sputtering and subsequently crystallized by oblique ion bombardment. Crystalline texture nucleated by the ion beam was replicated by solid-phase epitaxial growth throughout the formerly amorphous yttria-stabilized zirconia (YSZ) film. The resulting YSZ films have (211) orientation normal to the substrate with in-plane directions (111), parallel, and (110), transverse, to the azimuth of the ion beam. We hypothesize that the texture mechanism involves ion-induced film compression and shear. The results, taken together with prior work, show that oblique ion texturing of amorphous films is a general phenomenon that can be used to fabricate substrates with more than one type of crystallographic orientation

  12. Droop-free AlxGa1-xN/AlyGa1-yN quantum-disks-in-nanowires ultraviolet LED emitting at 337 nm on metal/silicon substrates

    KAUST Repository

    Janjua, Bilal

    2017-01-18

    Currently the AlGaN-based ultraviolet (UV) solid-state lighting research suffers from numerous challenges. In particular, low internal quantum efficiency, low extraction efficiency, inefficient doping, large polarization fields, and high dislocation density epitaxy constitute bottlenecks in realizing high power devices. Despite the clear advantage of quantum-confinement nanostructure, it has not been widely utilized in AlGaN-based nanowires. Here we utilize the self-assembled nanowires (NWs) with embedding quantum-disks (Qdisks) to mitigate these issues, and achieve UV emission of 337 nm at 32 A/cm (80 mA in 0.5 × 0.5 mm device), a turn-on voltage of ∼5.5 V and droop-free behavior up to 120 A/cm of injection current. The device was grown on a titanium-coated n-type silicon substrate, to improve current injection and heat dissipation. A narrow linewidth of 11.7 nm in the electroluminescence spectrum and a strong wavefunctions overlap factor of 42% confirm strong quantum confinement within uniformly formed AlGaN/AlGaN Qdisks, verified using transmission electron microscopy (TEM). The nitride-based UV nanowires light-emitting diodes (NWs-LEDs) grown on low cost and scalable metal/silicon template substrate, offers a scalable, environment friendly and low cost solution for numerous applications, such as solid-state lighting, spectroscopy, medical science and security.

  13. Trifluoroacetate metal organic deposition derived (Y0.77Gd0.23)Ba2Cu3O y films on CeO2 buffered R-plane Al2O3 substrates

    Science.gov (United States)

    Sakuma, Keita; Sato, Michio; Miura, Masashi

    2018-03-01

    (Y0.77Gd0.23)Ba2Cu3O y [(Y,Gd)BCO] films were grown on CeO2 buffered R-plane sapphire (R-Al2O3) substrates using trifluoroacetate metal organic deposition (TFA-MOD). Annealing of the CeO2 buffered R-Al2O3 substrates was performed to control the crystallinity and surface morphology of the CeO2 buffer layer. The annealing treatment led to a significant improvement in the crystallinity and surface morphology of the CeO2 buffer layer. A (Y,Gd)BCO film grown on the CeO2 buffer layer with high crystallinity and an atomically flat surface exhibited high self-field (at 77 K) and in-field (at 20 K, 9 T, μ0 H∥c) critical current densities (J c). Annealing of the CeO2 buffer layer thus enabled enhancement of not only the self-field J c for the (Y,Gd)BCO film but also the in-field J c.

  14. Forward impact extrusion of surface textured steel blanks using coated tooling

    Science.gov (United States)

    Hild, Rafael; Feuerhack, Andreas; Trauth, Daniel; Arghavani, Mostafa; Kruppe, Nathan C.; Brögelmann, Tobias; Bobzin, Kirsten; Klocke, Fritz

    2017-10-01

    A method to enable dry metal forming by the means of a self-lubricating coating and surface textures was researched using an innovative Pin-On-Cylinder-Tribometer. The experimental analysis was complemented by a numerical model of the complex contact conditions between coated tools and the surface textured specimen at the micro-level. Based on the results, the explanation of the tribological interactions between surface textured specimens and the tool in dry full forward extrusion is the objective of this work. Therefore, experimental dry extrusion tests were performed using a tool system. The extruded specimens were evaluated regarding their geometry as well as by the required punch force. Thereby, the effectiveness and the feasibility of dry metal forming on the example of full forward extrusion was evaluated. Thus, one more step towards the technical realization of dry metal forming of low alloy steels under industrial conditions was realized.

  15. Texture Classification for 3D Urban Map

    Directory of Open Access Journals (Sweden)

    Inatsuka Hiroyuki

    2009-01-01

    Full Text Available This paper proposes a method to control texture resolution for rendering large-scale 3D urban maps. Since on the 3D maps texture data generally tend to be far larger than geometry information such as vertices and triangles, it is more effective to reduce the texture by exploiting the LOD (Level of Detail in order to decrease whole data size. For this purpose, we propose a new method to control the resolution of the texture. In our method we classify the textures to four classes based on their salient features. The appropriate texture resolutions are decided based on the classification resulsts, their rendered sizes on a display, and their level of importance. We verify the validity of our texture classification algorithm by applying it to the large-scale 3D urban map rendering.

  16. Comparison of germination and seed vigor of sunflower in two contaminated soils of different texture

    Science.gov (United States)

    Zhao, Xin; Han, Jaemaro; Lee, Jong Keun; Kim, Jae Young

    2014-05-01

    Phytoremediation as an emerging low-cost and ecologically friendly alternative to the conventional soil remediation technologies has gained a great deal of attention and into lots of research. As a kind of the methods that use of green plants to remediate heavy metals contaminated soils, the early growth status of plant seeds in the contaminated environmental directly affects the effect of phytoremediation. Germination test in the water (aqueous solution of heavy metal) is generally used for assessing heavy metal phytotoxicity and possibility of plant growth, but there is a limit. Because soil is commonly main target of phytoremediation, not the water. The bioavailability of heavy metals in the soil also depends on the texture. So soil texture is an important factor of phytoremediation effect. Sunflower is the representative species which have good tolerance to various heavy metals; furthermore, the seeds of sunflower can be used as the raw-material for producing bio-diesel. The objectives of this research were to investigate germination rate of sunflowers in various heavy metal contaminated soils and to compare the seedling vigor index (SVI) of sunflower in two contaminated soils of different texture. Sunflower (Helianthusannuus L.) seeds were obtained from a commercial market. In order to prove the soil texture effect on heavy metal contaminated soil, germination tests in soil were conducted with two different types of soil texture (i.e., loam soil and sandy loam soil) classified by soil textural triangle (defined by USDA) including representative soil texture of Korea. Germination tests in soil were conducted using KS I ISO 11260-1 (2005) for reference that sunflower seeds were incubated for 7 days in dark at 25 ± 1 Celsius degree. The target heavy metals are Nickel (Ni) and Zinc (Zn). The Ni and Zn concentrations were 0, 10, 50, 100, 200, 300, 500 mg-Ni/kg-dry soil, and 0, 10, 50, 100, 300, 500, 900 mg-Zn/kg-dry soil, respectively. After germination test for 7

  17. Carrier transport in polycrystalline silicon thin films solar cells grown on a highly textured structure

    Czech Academy of Sciences Publication Activity Database

    Honda, Shinya; Takakura, H.; Hamakawa, Y.; Muhida, R.; Kawamura, T.; Harano, T.; Toyama, T.; Okamoto, H.

    2004-01-01

    Roč. 43, 9A (2004), s. 5955-5959 ISSN 0021-4922 Institutional research plan: CEZ:AV0Z1010914 Keywords : polycrystalline silicon thin film * solar cells * substrate texture Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.142, year: 2004

  18. Metal-oxide-semiconductor devices based on epitaxial germanium-carbon layers grown directly on silicon substrates by ultra-high-vacuum chemical vapor deposition

    Science.gov (United States)

    Kelly, David Quest

    After the integrated circuit was invented in 1959, complementary metal-oxide-semiconductor (CMOS) technology soon became the mainstay of the semiconductor industry. Silicon-based CMOS has dominated logic technologies for decades. During this time, chip performance has grown at an exponential rate at the cost of higher power consumption and increased process complexity. The performance gains have been made possible through scaling down circuit dimensions by improvements in lithography capabilities. Since scaling cannot continue forever, researchers have vigorously pursued new ways of improving the performance of metal-oxide-semiconductor field-effect transistors (MOSFETs) without having to shrink gate lengths and reduce the gate insulator thickness. Strained silicon, with its ability to boost transistor current by improving the channel mobility, is one of the methods that has already found its way into production. Although not yet in production, high-kappa dielectrics have also drawn wide interest in industry since they allow for the reduction of the electrical oxide thickness of the gate stack without having to reduce the physical thickness of the dielectric. Further out on the horizon is the incorporation of high-mobility materials such as germanium (Ge), silicon-germanium (Si1-xGe x), and the III-V semiconductors. Among the high-mobility materials, Ge has drawn the most attention because it has been shown to be compatible with high-kappa dielectrics and to produce high drive currents compared to Si. Among the most difficult challenges for integrating Ge on Si is finding a suitable method for reducing the number of crystal defects. The use of strain-relaxed Si1- xGex buffers has proven successful for reducing the threading dislocation density in Ge epitaxial layers, but questions remain as to the viability of this method in terms of cost and process complexity. This dissertation presents research on thin germanium-carbon (Ge 1-yCy layers on Si for the fabrication

  19. Pulsed injection metal organic chemical vapour deposition and characterisation of thin CaO films

    Energy Technology Data Exchange (ETDEWEB)

    Borges, R.P., E-mail: rpborges@fc.ul.p [Centro de Fisica da Materia Condensada, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Ferreira, P. [Departamento de Engenharia Ceramica e do Vidro, CICECO, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Saraiva, A. [Centro de Fisica da Materia Condensada, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Goncalves, R., E-mail: rjbarrosog@hotmail.co [Centro de Fisica da Materia Condensada, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Rosa, M.A. [Centro de Fisica da Materia Condensada, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Goncalves, A.P. [Centro de Fisica da Materia Condensada, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Departamento de Quimica, Instituto Tecnologico e Nuclear, P-2686-953 Sacavem (Portugal); Silva, R.C. da [Laboratorio de Feixe de Ioes, Dep. Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Magalhaes, S. [Laboratorio de Feixe de Ioes, Dep. Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Lourenco, M.J.V.; Santos, F.J.V. [Centro de Ciencias Moleculares e Materiais, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016, Lisboa (Portugal); Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Godinho, M. [Centro de Fisica da Materia Condensada, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Dep. de Fisica, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal)

    2009-05-01

    Thin films of CaO were grown on silicon (Si) and lanthanum aluminate (LaAlO{sub 3}) substrates by pulsed injection metal-organic chemical vapour deposition in a vertical injection MOCVD system. Growth parameters were systematically varied to study their effect on film growth and quality and to determine the optimal growth conditions for this material. Film quality and growth rate were evaluated by atomic force microscopy, X-ray diffraction and Rutherford Backscattering Spectroscopy measurements. Optimised conditions allowed growing transparent, single phase films textured along the (0 0 l) direction.

  20. Experimental investigation of new manufacturing process chains to create micro-metal structures on polymer substrates for lab-on-chip sensors

    DEFF Research Database (Denmark)

    Calaon, Matteo; Islam, Aminul; Hansen, Hans Nørgaard

    2012-01-01

    Over the last two decades, lab-on-a-chip devices have emerged as a leading technology for life sciences, drug development, medical diagnostics, food safety, agricultural and environmental monitoring. The conventional methods used nowadays to manufacture these micro- and nano-functional surface to...... olefin co-polymer substrates. The achievements authorize to consider the proposed process chain a valid option to fabricate structured surface topography in the sub-μ range for biological applications.......Over the last two decades, lab-on-a-chip devices have emerged as a leading technology for life sciences, drug development, medical diagnostics, food safety, agricultural and environmental monitoring. The conventional methods used nowadays to manufacture these micro- and nano-functional surface...... topography are very expensive, and they do not fit the requirements for industrial production. In particular, we report an experimental investigation to link technologies as structuring process and replication processes by establishing through the proposed low-cost-based approaches new manufacturing process...