WorldWideScience

Sample records for assembled coated conductor

  1. Transport losses in single and assembled coated conductors with textured-metal substrate with reduced magnetism

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, N. [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan)], E-mail: amemiya@kuee.kyoto-u.ac.jp; Jiang, Z.; Li, Z.; Nakahata, M. [Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Kato, T.; Ueyama, M. [Sumitomo Electric Ind., Ltd., Electric Power and Energy Research Laboratories, 1-1-3, Shimaya, Konohana, Osaka 554-0024 (Japan); Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1 Kita-Sekiyama, Ohdaka, Midori, Nagoya 459-8522 (Japan); Shiohara, S. [Superconductivity Research Laboratory, ISTEC, 1-10-13 Shinonome, Koto, Tokyo 136-0062 (Japan)

    2008-09-15

    Transport losses in a coated conductor with a textured-metal substrate with reduced magnetism were studied experimentally. The substrate is with a clad structure, and HoBCO superconductor layer is deposited on the substrate with buffer layers. The measured transport loss of a sample whose critical current is 126.0 A falls between Norris's strip value and Norris's ellipse value. The increase in the measured transport loss from Norris's strip value can be attributed to its non-uniform lateral J{sub c} distribution. The same buffered clad tape was placed under an IBAD-MOCVD coated conductor with a non-magnetic substrate, and its transport loss was measured. The comparison between the measured transport loss of this sample and that of the identical IBAD-MOCVD coated conductor without the buffered clad tape indicates that the increase in the transport loss due to this buffered clad tape is small. The transport losses of hexagonal assemblies of IBAD-MOCVD coated conductors, whose structure simulates that of superconducting power transmission cables, were also measured where the buffered clad tapes were under-lied or over-lied on the coated conductors. The increase in the transport loss of hexagonal assemblies of coated conductors due to the buffered clad tapes is at an allowable level.

  2. Low ac loss geometries in YBCO coated conductors and impact on conductor stability

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, Robert C [ORNL; List III, Frederick Alyious [ORNL; Paranthaman, Mariappan Parans [ORNL; Rupich, M. W. [American Superconductor Corporation, Westborough, MA; Zhang, W. [American Superconductor Corporation, Westborough, MA; Xie, Y. Y. [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York

    2007-01-01

    Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac fields up to 100 mT. While ac loss reduction was achieved with YBCO filaments created through laser scribing and inkjet deposition, the assembly of stacked YBCO conductor provides an alternative method of ac loss reduction. When compared to a 4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of 2-mm wide YBCO coated conductors with a similar total critical current was reduced. While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the engineering current density of the conductor, further reduction of ac loss was obtained through the splicing of the 2-mm wide tapes with low resistance solders. To better determine the practicality of these methods from a stability point of view, a numerical analysis was carried out to determine the influence of bridging and splicing on stability of a YBCO coated conductor for both liquid nitrogen-cooled and conduction cooled geometries.

  3. Persistent currents in a magnetic bearing with coated conductors

    Science.gov (United States)

    Sass, F.; Ramos de Castro, André; Gonçalves Sotelo, Guilherme; de Andrade, R.

    2015-11-01

    Superconducting magnetic bearings are normally built with bulk superconductors. Since coated conductors properties are far superior, we have proposed in a previous work the replacement of bulks for stacks of 2G wires in magnetic levitation devices. A major limitation of this replacement lies in the fact that the induced current is constrained in narrow loops along the available commercial widths of 2G wires. This work presents a technique to achieve wider loops of persistent current without the need of increasing the coated conductors width. As a result, the use of 2G wires in magnetic bearings took a step towards its economical feasibility.

  4. Numerical analysis of quench in coated conductors with defects

    Directory of Open Access Journals (Sweden)

    Wenbin Liu

    2016-09-01

    Full Text Available When the superconductor is subjected to local thermal perturbations, a large amount of joule heat may be generated in the conductor, which may lead to a quench. In a quench event, a normal zone irreversibly spreads throughout the conductor leading to failure of the superconducting device. In this paper, we will discuss the one-dimensional quench behavior in the coated conductors with internal defects or interface defects. Based on the numerical procedure given in the previous works, the normal zone propagation is studied by using the finite difference method. The numerical results are presented to discuss the normal zone propagation. We consider the effect of internal defect on the nonuniform temperature propagation. For the conductor with interface defects, it can be found that the normal zone propagation velocity is increased by defects.

  5. Overview of Materials and Power Applications of Coated Conductors Project

    Science.gov (United States)

    Shiohara, Yuh; Taneda, Takahiro; Yoshizumi, Masateru

    2012-01-01

    There are high expectations for coated conductors in electric power applications such as superconducting magnetic energy storage (SMES) systems, power cables, and transformers owing to their ability to contribute to stabilizing and increasing the capacity of the electric power supply grid as well as to reducing CO2 emission as a result of their high critical-current characteristics. Research and development has been performed on wires/tapes and electric power devices worldwide. The Materials and Power Applications of Coated Conductors (M-PACC) Project is a five-year national project in Japan started in 2008, supported by the Ministry of Economy, Trade and Industry (METI) and the New Energy and Industrial Technology Development Organization (NEDO), to develop both coated conductors that meet market requirements and basic technologies for the above-mentioned power applications using coated conductors. In this article, research and development results are reviewed and compared with the interim/final targets of the project, and future prospects are discussed.

  6. Comparative characterization of Cu–Ni substrates for coated conductors

    DEFF Research Database (Denmark)

    Tian, H.; Suo, H.L.; Wulff, Anders Christian

    2014-01-01

    Three Cu100xNix alloys, with x = 23, 33 and 45 at.%Ni, have been evaluated for use as substrates for coated conductors on the basis of measurements of their microstructure, crystallographic texture and hardness. It is found that high-temperature annealing after heavy rolling generates strong cube...

  7. High-field thermal transports properties of REBCO coated conductors

    CERN Document Server

    Bonura, M

    2015-01-01

    The use of REBCO coated conductors is envisaged for many applications, extending from power cables to high-field magnets. Whatever the case, thermal properties of REBCO tapes play a key role for the stability of superconducting devices. In this work, we present the first study on the longitudinal thermal conductivity (k) of REBCO coated conductors in magnetic fields up to 19 T applied both parallelly and perpendicularly to the thermal-current direction. Copper-stabilized tapes from six industrial manufacturers have been investigated. We show that zero-field k of coated conductors can be calculated with an accuracy of ‡ 15% from the residual resistivity ratio of the stabilizer and the Cu/non-Cu ratio. Measurements performed at high fields have allowed us to evaluate the consistency of the procedures generally used for estimating in-field k in the framework of the Wiedemann-Franz law from an electrical characterization of the materials. In-field data are intended to provide primary ingredients for the ...

  8. IBAD-MgO technology for coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, William [Dept. of Physics, Ewha Womans University, Seoul (Korea, Republic of)

    2016-09-15

    Ion-beam assisted deposition (IBAD) technology has been successfully applied to high-temperature superconductor coated conductors (CC) as textured substrates. Since the coated conductors were proposed as a potential framework for utilizing the superior transport characteristics of YBa2Cu3O7 and related cuprate oxides, several methods including rolling-assisted bi-axial textured substrates (RABiTS) and inclined substrate deposition (ISD), as well as IBAD, have been attempted. As of 2016, most companies that are trying to commercialize CC adapt IBAD technology except for American Superconductors who use RABiTS predominantly. For the materials in the IBAD process, initial efforts to use yttria-stabilized zirconia (YSZ) or related fluorites in Fujikura in Japan have quickly given way to MgO which technique was developed by Stanford University in the USA. In this review, we present a historical overview of IBAD technology, in particular, for the application of CC. We describe the key scientific understanding of nucleation, the texturing mechanism, and the growth of large bi-axial grains and discuss some potential new IBAD materials and systems for large-scale production.

  9. Improvement of spatial homogeneity in IBAD based YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Zulkifli, Z. [Department of Electrical and Electronic Systems Engineering, Graduate School of ISEE, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka-shi 819-0395 (Japan)], E-mail: zulis@super.ees.kyushu-u.ac.jp; Kiss, T.; Inoue, M.; Enpuku, K. [Department of Electrical and Electronic Systems Engineering, Graduate School of ISEE, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka-shi 819-0395 (Japan); Kashima, N.; Watanabe, T.; Mori, M.; Nagaya, S. [Chubu Electric Power Co., Inc., Nagoya 459-8522 (Japan); Ibi, A.; Miyata, S.; Yamada, Y. [Superconductivity Research Laboratory, Nagoya Coated Conductor Center, Nagoya 456-8587 (Japan); Shiohara, Y. [Superconductivity Research Laboratory, Division of Superconducting Tape and Wire, Tokyo 135-0062 (Japan)

    2008-09-15

    Prior to the development of fabrication technique for the chemical vapor deposited (CVD) YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} coated conductor on a IBAD-Gd{sub 2}Zr{sub 2}O{sub 7}, investigations on the improvement of spatial homogeneity have been done. By using spatially resolved measurements and combined multiple microanalysis techniques with length scale of several {mu}m, physical and transport properties of the CVD samples have been investigated before and after fabrication modification. Structural inhomogeneity was visualized using thermoelectric voltage imaging (TVI) technique using a laser scanning microscope. Laser scanning microscopy at superconducting temperature is used to visualize flux flow dissipation; furthermore, mappings of 2D local current flow density distribution have been done using a scanning SQUID microscopy. It has been shown that the superconducting layer consisted of YBCO matrix with localized defects originating from the buffer layer. This led to current non-uniformity and caused high flux flow dissipation within the vicinity of the defects. Process conditions have been modified effectively based on those insights. After fabrication modification, our measurement analyses shows that the texturing of the YBCO layer improved significantly and the appearance of spatially distributed obstacles that are responsible for non-uniform current distribution and localized dissipation are reduced. Our complementing, quick yet non-invasive technique not only can quantify the improvement of YBCO homogeneity but also shed light on the basic understanding of the current limiting mechanism in the IBAD based coated conductors.

  10. Solderability study of RABiTS-based YBCO coated conductors

    Science.gov (United States)

    Zhang, Yifei; Duckworth, Robert C.; Ha, Tam T.; Gouge, Michael J.

    2011-08-01

    The solderability of commercially available YBa2Cu3O7-x (YBCO) coated conductors that were made from Rolling Assisted Biaxially Textured Substrates (RABiTS)-based templates was studied. The coated conductors, also known as second-generation (2G) high temperature superconductor (HTS) wires (in the geometry of flat tapes about 4 mm wide), were laminated with copper, brass, or stainless steel strips as stabilizers. To understand the factors that influence their solderability, surface profilometry and scanning electron microscopy were used to characterize the wire surfaces. The solderability of three solders, 52In48Sn, 67Bi33In, and 100In (wt.%), was evaluated using a standard test (IPC/ECA J-STD-002) and with two different commercial fluxes. It was found that the solderability varied with the solder and flux but the three different wires showed similar solderability for a fixed combination of solder and flux. Solder joints of the 2G wires were fabricated using the tools and the procedures recommended by the HTS wire manufacturer. The solder joints were made in a lap-joint geometry and with the superconducting sides of the two wires face-to-face. The electrical resistances of the solder joints were measured at 77 K, and the results were analyzed to qualify the soldering materials and evaluate the soldering process. It was concluded that although the selection of soldering materials affected the resistance of a solder joint, the resistivity of the stabilizer was the dominant factor.

  11. Impact of Inhomogeneities in HTS Coated Conductors for Resistive FCLs

    Science.gov (United States)

    Colangelo, Daniele; Memiaghe, Steeve; Lacroix, Christian; Sirois, Frédéric; Dutoit, Bertrand

    Several issues remain to be addressed for the commercial development of ResistiveFault Current Limiters based on superconducting technologies (RFCL). In particular, the inhomogeneity of high temperature superconducting coated conductors (HTS-CC) combined with the diffculty to predict RFCLs behaviour when interfaced with the existing electrical grid represents an important bottleneck that limits their competitiveness on the electrical market. In order to study the influence of the local inhomogeneity of the HTS tape on the global effective performance of an RFCL, a modular equivalent circuit model has been developed using SimPowerSystemsTM. The model implements an inhomogeneity distribution based on statistical data and takes into account the thermal conduction between different zones of the HTS-CC. It has been calibrated with experimental measurements and finite element simulations. The model can be used to study various scenarios common to power systems, such as transformer in-rush currents, motor starts, etc.

  12. All MOD buffer/YBCO approach to coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Parans Paranthaman, M. [Chemical Sciences Division, Oak Ridge National Laboratory, Building 4500 South, Room S-244, MS-6100, Oak Ridge, TN 37831-6100 (United States)]. E-mail: paranthamanm@ornl.gov; Sathyamurthy, S. [Chemical Sciences Division, Oak Ridge National Laboratory, Building 4500 South, Room S-244, MS-6100, Oak Ridge, TN 37831-6100 (United States); Heatherly, L. [Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6116 (United States); Martin, P.M. [Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6116 (United States); Goyal, A. [Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6116 (United States); Kodenkandath, T. [American Superconductor Corporation, Westborough, MA 01581 (United States); Li, X. [American Superconductor Corporation, Westborough, MA 01581 (United States); Thieme, C.L.H. [American Superconductor Corporation, Westborough, MA 01581 (United States); Rupich, M.W. [American Superconductor Corporation, Westborough, MA 01581 (United States)

    2006-10-01

    RABiTS based metal-organic deposition (MOD) buffer/YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) approach has been considered as one of the potential, low-cost approaches to fabricate high performance second generation coated conductors. The most commonly used RABiTS architectures consisting of a starting template of biaxially textured Ni-W (5 at.%) substrate with a seed layer of Y{sub 2}O{sub 3}, a barrier layer of YSZ, and a CeO{sub 2} cap. In this three layer architecture, all the buffers are deposited using physical vapor deposition (PVD) techniques. Using these PVD deposited templates, 0.8-{mu}m thick MOD-YBCO films with an I {sub c} (critical current) of 250 A/cm have been achieved routinely in short lengths. We have developed a low-cost, non-vacuum, MOD process to grow epitaxial buffer layers on textured Ni-5W substrates. The main challenge in this effort is to match the performance of MOD templates to that of PVD templates. We have recently shown that the properties of MOD-La{sub 2}Zr{sub 2}O{sub 7} (LZO) layers can be improved by inserting a thin Y{sub 2}O{sub 3} seed layer. Using MOD-CeO{sub 2} cap layers, we have demonstrated the growth of high performance MOD-YBCO films with an I {sub c} of 200 A/cm-width on MOD-La{sub 2}Zr{sub 2}O{sub 7}/Y{sub 2}O{sub 3}/Ni-5W substrates. This approach could potentially decrease the overall cost of the coated conductor fabrication.

  13. All MOD Buffer/YBCO Approach to Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, Mariappan Parans [ORNL; Sathyamurthy, Srivatsan [ORNL; Heatherly Jr, Lee [ORNL; Martin, Patrick M [ORNL; Goyal, Amit [ORNL; Kodenkandath, Thomas [American Superconductor Corporation, Westborough, MA; Li, Xiaoping [American Superconductor Corporation, Westborough, MA; Thieme, C. L. H. [American Superconductor Corporation, Westborough, MA; Rupich, Marty [American Superconductor Corporation, Westborough, MA

    2006-01-01

    RABiTS based metal-organic deposition (MOD) buffer/YBa2Cu3O7-d (YBCO) approach has been considered as one of the potential, low-cost approaches to fabricate high performance second generation coated conductors. The most commonly used RABiTS architectures consisting of a starting template of biaxially textured Ni-W (5 at.%) substrate with a seed layer of Y2O3, a barrier layer of YSZ, and a CeO2 cap. In this three layer architecture, all the buffers are deposited using physical vapor deposition (PVD) techniques. Using these PVD deposited templates, 0.8-{mu}m thick MOD-YBCO films with an Ic (critical current) of 250 A/cm have been achieved routinely in short lengths. We have developed a low-cost, non-vacuum, MOD process to grow epitaxial buffer layers on textured Ni-5W substrates. The main challenge in this effort is to match the performance of MOD templates to that of PVD templates. We have recently shown that the properties of MOD-La2Zr2O7 (LZO) layers can be improved by inserting a thin Y2O3 seed layer. Using MOD-CeO2 cap layers, we have demonstrated the growth of high performance MOD-YBCO films with an Ic of 200 A/cm-width on MOD-La2Zr2O7/Y2O3/Ni-5W substrates. This approach could potentially decrease the overall cost of the coated conductor fabrication.

  14. YBCO coated conductor by multiple-stage CVD

    Energy Technology Data Exchange (ETDEWEB)

    Kashima, N. [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan)]. E-mail: kashima.naoji@chuden.co.jp; Niwa, T. [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Mori, M. [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Nagaya, S. [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Muroga, T. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Miyata, S. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Watanabe, T. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Yamada, Y. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Izumi, T. [ISTEC-SRL, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Shiohara, Y. [ISTEC-SRL, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2005-10-01

    A high speed deposition technique for YBCO coated conductors has been required from the viewpoint of cost reduction for second generation wire. The multiple-stage chemical vapor deposition technique was employed for making YBCO coated conductors with a high deposition rate. In our earlier research, over 2.0 MA/cm{sup 2} of J {sub c} was confirmed on IBAD (PLD-CeO{sub 2}/IBAD-Gd{sub 2}Zr{sub 2}O{sub 7}/Hastelloy) substrates with a maximum deposition rate of 25 m/h using the six-stage CVD system. To evaluate the availability of the multiple-stage CVD technique for making a longer YBCO tape, we have fabricated a 200 m-long YBCO tape on a non-textured silver substrate. Deposition rate was 10 m/h, and number of passing was two times. Total deposition time was 40 h (20 h x 2). During the deposition of a YBCO layer, the CVD system was quite stable. J {sub c} was measured at a voltage tap interval of 10 m with criterion of 1 {mu}V/cm. J {sub c} of the YBCO tape remained in the order of 10{sup 4} A/cm{sup 2} due to the non-textured microstructure. However, J {sub c} distribution of the tape showed a good uniformity. A 210 m-long YBCO/(Ag + IBAD) tape was also prepared. A 210 m-long substrate combined with IBAD and Ag was used. I {sub c} of 60-78 A was obtained on the IBAD substrates part. This result suggested that the multiple-stage CVD technique was very useful to making a long YBCO tape.

  15. Experiment and simulation of superconducting magnetic levitation with REBCO coated conductor stacks

    Science.gov (United States)

    Liu, Kun; Yang, Wenjiao; Ma, Guangtong; Quéval, Loïc; Gong, Tianyong; Ye, Changqing; Li, Xiang; Luo, Zhen

    2018-01-01

    Three superconducting stacks made of 120 REBCO coated conductor tapes were each fabricated and assembled to obtain several REBCO modules. Their levitation responses over two different permanent magnet (PM) guideways were investigated by experiment and finite element simulation. For the experiment, a test rig was developed that can measure the force in the three directions for any given relative movement between the REBCO stacks and the PM guideway. For the finite element simulation, a 2D H-formulation was adopted. To treat the high aspect ratio of REBCO tapes, an anisotropic homogenization technique was used. The agreement between the measurements and the simulations is good, thus validating the modeling methodology. It was observed from the experiment and simulation results that the perpendicular field contributes to the levitation force whereas the parallel field is responsible for the guidance force, as a result of the existence of anisotropy on the local magnetic stimulation. Based on that, promising REBCO modules including both longitudinal and transverse arrangements of REBCO stacks were proposed and tested, in terms of providing a significant levitation force with the lateral stability preserved. Moreover, a pre-load process able to suppress the relaxation of the levitation force was put forward. To conclude, this study outlines explicit principles to obtain an appropriate layout of coated conductor stacks that could be effective for practical magnetic levitation operation.

  16. 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...... 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....

  17. Progress of long coated conductors fabrication with fluorine-free CSD method at SWJTU

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y., E-mail: yzhao@swjtu.edu.cn [Key Lab of Advanced Materials Technologies, Key Lab of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education), Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia); Wang, W.T.; Lei, M.; Pu, M.H.; Zhang, Y. [Key Lab of Advanced Materials Technologies, Key Lab of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education), Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)

    2013-10-15

    Highlights: • Recent progress on the long coated conductors fabrication by F-free CSD method is presented. • Single buffer and partial-melting technology and slot-die coating methods have been developed. • Reel-to-reel facilities for continuous process have been achieved. -- Abstract: Recent progress on the fabrication of long high-T{sub c} superconducting coated conductors with a fluorine-free chemical solution deposition (CSD) method is presented. Developments including such novel methods as single buffer technology, partial-melting process on YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO), slot-die coating and drying; reel-to-reel facilities for continuous process have been achieved in the effort on high-T{sub c} superconducting coated conductors at SWJTU, which form a comprehensive technology to fabricate long coated tapes with high performances.

  18. Biaxially textured copper-iron alloys for coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Gallistl, Bernhard; Hassel, Achim Walter [Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University, Altenberger Str. 69, 4040 Linz (Austria); Kirchschlager, Raimund [Institute for Semiconductor and Solid State Physics, Johannes Kepler University, Altenberger Str. 69, 4040 Linz (Austria)

    2012-05-15

    Two copper based biaxially textured alloys containing 0.37 and 0.91 wt.%-Fe have been investigated for the use as substrate material for coated conductors. Average full width at half maximum (FWHM) values of 7.3 (CuFe0.37) and 6.8 (CuFe0.91) for in-plane alignment and 7.2 (CuFe0.37, CuFe0.91) for out-of-plane are achieved. Ultimate tensile strength for the two alloys is found to be much higher compared to the values for Cu and CuFe2.35. Hysteresis losses are dramatically reduced compared to other available substrate materials. Magnetisation data for both alloys obtained at 5 K show an anticipated saturation magnetisation (M{sub s}) <0.35 {mu}Wb m kg{sup -1}, which is less than 1% of pure Ni. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. High-field thermal transport properties of REBCO coated conductors

    Science.gov (United States)

    Bonura, Marco; Senatore, Carmine

    2015-02-01

    The use of REBCO coated conductors (CCs) is envisaged for many applications, extending from power cables to high-field magnets. Whatever the case, thermal properties of REBCO tapes play a key role for the stability of superconducting devices. In this work, we present the first study on the longitudinal thermal conductivity (κ) of REBCO CCs in magnetic fields up to 19 T applied both parallel and perpendicularly to the thermal-current direction. Copper-stabilized tapes from six industrial manufacturers have been investigated. We show that zero-field κ of CCs can be calculated with an accuracy of +/- 15% from the residual resistivity ratio of the stabilizer and the Cu/non-Cu ratio. Measurements performed at high fields have allowed us to evaluate the consistency of the procedures generally used for estimating in-field κ in the framework of the Wiedemann-Franz law from an electrical characterization of the materials. In-field data are intended to provide primary ingredients for the thermal stability analysis of high-temperature superconductor-based magnets.

  20. AC susceptibility as a characterization tool for coated conductor tapes

    Science.gov (United States)

    Gömöry, F.; Vojenčiak, M.; Solovyov, M.; Frolek, L.; Šouc, J.; Seiler, E.; Bauer, M.; Falter, M.

    2017-11-01

    The measurement and analysis of magnetic AC susceptibility is a useful tool in the study of superconductor (SC) materials. Exposure of a sample to a magnetic field changing in time generates loops of electrical currents that are detectable in a contactless way with the help of a suitable pick-up system. In this paper the applicability of this technique in the characterization and quality control of coated conductor (CC) tapes is evaluated. First we recollect the essential results of the analytical theory derived for thin SC strips and their extrapolation to strips with finite thickness. From the analytical expressions one can see how the properties of CC tape that are important for application in electric power devices, namely its critical current and AC loss, can be deduced from AC susceptibility data in straightforward way. The main focus of our study is to investigate the influence that various cases of non-uniformities in SC layer exhibit on the magnetic properties examined in an AC regime. Numerical computations were used to explore the consequences of lateral variation in the critical current density. Predictions derived for some model cases were compared with experimental findings. A dedicated experiment was also carried out to demonstrate that a transverse scratch that would be detrimental for DC transport could sneak unobserved through the AC magnetic experiment on a long sample. Our study shows that the analysis of both parts of the complex magnetic susceptibility in place of a mere AC loss determination in a common AC magnetization experiment is worth the additional effort.

  1. Development of long YBCO coated conductors by multiple-stage CVD

    Energy Technology Data Exchange (ETDEWEB)

    Mori, M. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan)]. E-mail: Mori.Masami2@chuden.co.jp; Watanabe, T. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Kashima, N. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Nagaya, S. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Muroga, T. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Miyata, S. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Yamada, Y. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Izumi, T. [ISTEC-SRL, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Shiohara, Y. [ISTEC-SRL, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2006-10-01

    We have developed YBCO coated conductors by Multiple-Stage Chemical Vapor Deposition (MS-CVD) technique, which can make YBCO layer with high deposition rate and easy to scale up by increasing the number of reactors. We confirmed that the high speed production by the twelve-stage CVD equipment, which was designed to scale up CVD process, did not affect the property of YBCO coated conductors and that the YBCO coated conductors with I {sub c} of 100 A-class could be fabricated by the high speed production of 10 m/h. In order to demonstrate the advantage of the MS-CVD technique for longer YBCO coated conductors, we have also fabricated the 92-m-long YBCO conductor on an IBAD substrate. The YBCO conductor was fabricated with a tape moving at the speed of 25 m/h and was deposited several times to control the thickness of the YBCO films. The end-to-end I {sub c} of the 92-m-long YBCO tape was measured by criterion of 1 {mu}V/cm and was 96 A (J {sub c} of 1.9 MA/cm{sup 2}). We have successfully realized the fabrication of the YBCO coated conductor with the practical properties of 100 A-class in I {sub c} and 100 m-class in length. Recently, we have also obtained high I {sub c} of 227 A (J {sub c} of 2.3 MA/cm{sup 2}) in a short sample of a YBCO conductor on IBAD substrates by optimization of the fabrication process.

  2. Influence of substrate magnetism of coated conductors on critical current distribution measurement using magnetic knife method

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Z. [Department of Electrical and Computer Engineering, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan)], E-mail: kyo@rain.dnj.ynu.ac.jp; Amemiya, N.; Onuma, T. [Department of Electrical and Computer Engineering, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Kato, T.; Ueyama, M. [Sumitomo Electric Ind., Ltd., Electric Power and Energy Research Laboratories, 1-1-3, Shimaya, Konohana, Osaka 554-0024 (Japan); Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1 Kita-Sekiyama, Ohdaka, Midori, Nagoya 459-8522 (Japan); Shiohara, Y. [Superconductivity Research Laboratory, ISTEC, 1-10-13 Shinonome, Koto, Tokyo 136-0062 (Japan)

    2008-09-15

    A YBCO coated conductor with non-magnetic substrate and a magnetic Ni alloy tape were prepared to investigate the influence of the substrate magnetism on the J{sub c} distribution measurement. We measured the J{sub c} distribution of the YBCO coated conductor and that of the same YBCO coated conductor with the magnetic tape over-lied on its face (the space between the superconducting layer and the magnetic tape is 20 {mu}m which is the thickness of protecting Ag layer), and compared the measured results with each other. The measured results agreed well with each other, and there was little influence of the tape magnetism on the J{sub c} distribution measurement. Based on this fact, the J{sub c} distribution in a HoBCO coated conductor with magnetic substrate was measured using the magnetic knife method. Twenty-two voltage taps were attached to the conductor with 5 mm separation along the conductor axis. The lateral J{sub c} distributions in the sections were generally in the shape of trapezoid.

  3. An evaluation of phase separated, self-assembled LaMnO3-MgO nanocomposite films directly on IBAD-MgO as buffer layers for flux pinning enhancements in YBa2YCu3O7-& coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Polat, Ozgur [ORNL; Aytug, Tolga [ORNL; Paranthaman, Mariappan Parans [ORNL; Leonard, Keith J [ORNL; Lupini, Andrew R [ORNL; Pennycook, Stephen J [ORNL; Meyer III, Harry M [ORNL; Kim, Kyunghoon [ORNL; Qiu, Xiaofeng [ORNL; Cook, Sylvester W [ORNL; Thompson, James R [ORNL; Christen, David K [ORNL; Goyal, Amit [ORNL; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Xiong, X. [SuperPower Incorporated, Schenectady, New York

    2010-01-01

    Technological applications of high temperature superconductors (HTS) require high critical current density, Jc, under operation at high magnetic field strengths. This requires effective flux pinning by introducing artificial defects through creative processing. In this work, we evaluated the feasibility of mixed-phase LaMnO3:MgO (LMO:MgO) films as a potential cap buffer layer for the epitaxial growth and enhanced performance of YBa2Cu3O7-d (YBCO) films. Such composite films were sputter deposited directly on IBAD-MgO templates (with no additional homo-epitaxial MgO layer) and revealed the formation of two phase-separated, but at the same time vertically aligned, self-assembled composite nanostructures that extend throughout the entire thickness of the film. The YBCO coatings deposited on these nanostructured cap layers showed correlated c-axis pinning and improved in-field Jc performance compared to those of YBCO films fabricated on standard LMO buffers. Microstructural characterization revealed additional extended disorder in the YBCO matrix. The present results demonstrate the feasibility of novel and potentially practical approaches in the pursuit of more efficient, economical, and high performance superconducting devices.

  4. Lateral J {sub c} distribution of YBCO coated conductors fabricated by IBAD/MOCVD process

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, N. [Department of Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan)]. E-mail: ame@rain.dnj.ynu.ac.jp; Maruyama, O. [Department of Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501 (Japan); Mori, M. [Chubu Electric Power Co., 20-1 Kita-Sekiyama, Ohdaka-cho, Midori, Nagoya 459-8522 (Japan); Kashima, N. [Chubu Electric Power Co., 20-1 Kita-Sekiyama, Ohdaka-cho, Midori, Nagoya 459-8522 (Japan); Watanabe, T. [Chubu Electric Power Co., 20-1 Kita-Sekiyama, Ohdaka-cho, Midori, Nagoya 459-8522 (Japan); Nagaya, S. [Chubu Electric Power Co., 20-1 Kita-Sekiyama, Ohdaka-cho, Midori, Nagoya 459-8522 (Japan); Shiohara, Y. [ISTEC-SRL, 1-10-13 Shinonome, Koto, Tokyo 135-0062 (Japan)

    2006-10-01

    The lateral J {sub c} distributions of YBCO coated conductors fabricated by IBAD/MOCVD process were measured by the magnetic knife method. In the samples, YBCO layer was deposited by MOCVD process on the IBAD template of GZO together with CeO{sub 2} layer. Ag-protective layer was put on YBCO layer. A series of voltage taps were attached with 10 mm separation, and the lateral J {sub c} distribution was measured in each section between two voltage taps. A sample YBCO coated conductor in which YBCO layer was deposited five times using an up-to-date set-up shows a rather uniform J {sub c} distribution. The magnitude of J {sub c} reaches 2 x 10{sup 10} A/m{sup 2} (2 MA/cm{sup 2}) in wide area of the conductor.

  5. 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...

  6. A Two-Level Undercut-Profile Substrate for Chemical-Solution-Based Filamentary Coated Conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Lundeman, Jesper H.; Hansen, Jørn B.

    2016-01-01

    A recently developed two-level undercut-profile substrate (2LUPS), containing two levels of plateaus connected by a curved wall with an undercut profile, enables self-forming filaments in a coated conductor during physical line-of-sight deposition of buffer and superconducting layers. In the pres...

  7. 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...

  8. Apparatus and method for measuring critical current properties of a coated conductor

    Science.gov (United States)

    Mueller, Fred M [Los Alamos, NM; Haenisch, Jens [Dresden, DE

    2012-07-24

    The transverse critical-current uniformity in a superconducting tape was determined using a magnetic knife apparatus. A critical current I.sub.c distribution and transverse critical current density J.sub.c distribution in YBCO coated conductors was measured nondestructively with high resolution using a magnetic knife apparatus. The method utilizes the strong depression of J.sub.c in applied magnetic fields. A narrow region of low, including zero, magnetic field in a surrounding higher field is moved transversely across a sample of coated conductor. This reveals the critical current density distribution. A Fourier series inversion process was used to determine the transverse J.sub.c distribution in the sample.

  9. Development of productive process for long coated conductors by EB evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Mori, M. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan)], E-mail: Mori.Masami2@chuden.co.jp; Watanabe, T.; Suda, N.; Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Izumi, T.; Shiohara, Y. [ISTEC-SRL, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2007-10-01

    We have installed original EB evaporation system and verified the performance of CeO{sub 2} buffer layers fabricated by EB evaporation method in the YBCO coated conductor in comparison with those fabricated by PLD method. The I{sub c} values of YBCO coated conductors obtained by same deposition for CVD-YBCO were 135 A (EB-CeO{sub 2} sample) and 126 A (PLD-CeO{sub 2} sample). Though the values of {delta}{phi} for the EB-CeO{sub 2} layer and PLD-CeO{sub 2} layer were different, the I{sub c} values of the YBCO were about the same. This result was shown that the CeO{sub 2} layer of {delta}{phi} = 10 deg. obtained by EB evaporation was equivalent in performance for YBCO coated conductors to the CeO{sub 2} layer of {delta}{phi} = 4 deg. obtained by PLD method. The influence of CeO{sub 2} film thickness for high speed production was examined. The I{sub c} did not show the remarkable difference with the reduction of CeO{sub 2} film thickness. The range of the I{sub c} was only about 20% of the maximum I{sub c} value, regardless of the progress by 5 times in the production speed of CeO{sub 2} buffer layers.

  10. Method of reducing multipole content in a conductor assembly during manufacture

    Science.gov (United States)

    Meinke, Rainer

    2013-08-20

    A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departs from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.

  11. Method of reducing multipole content in a conductor assembly during manufacture

    Science.gov (United States)

    Meinke, Rainer

    2016-05-24

    A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departs from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.

  12. Estimation of magnetic relaxation property for CVD processed YBCO-coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Y.; Kiuchi, M.; Otabe, E.S. [Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502 (Japan); Matsushita, T., E-mail: matusita@cse.kyutech.ac.j [Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502 (Japan); Shikimachi, K.; Watanabe, T.; Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan)

    2010-11-01

    Ion Beam Assist Deposition/Chemical Vapor Deposition(IBAD/CVD)-processed YBCO-coated conductors with high critical current density J{sub c} at high magnetic fields are expected to be applied to superconducting equipments such as superconducting magnetic energy storage (SMES). For application to superconducting magnet in SMES one of the most important properties for superconductors is the relaxation property of superconducting current. In this paper, the relaxation property is investigated for IBAD/CVD-processed YBCO-coated conductors of the superconducting layer in the range of 0.18-0.90 {mu}m. This property can be quantitatively characterized by the apparent pinning potential, U{sub 0}*. It is found that U{sub 0}* takes a smaller value due to the two-dimensional pinning mechanism at high magnetic fields for conductor with thinner superconducting layer. Although U{sub 0}* decreases with increasing thickness at low magnetic fields at 20 K, it increases at high magnetic fields. The results are theoretically explained by the model of the flux creep and flow based on the dimensionality of flux pinning. Scaling analysis is examined for the dependence of U{sub 0}{sup *} on the magnetic field, temperature and the layer thickness.

  13. Field and temperature scaling of the critical current density in commercial REBCO coated conductors

    CERN Document Server

    Senatore, Carmine; Bonura, Marco; Kulich, Miloslav; Mondonico, Giorgio

    2016-01-01

    Scaling relations describing the electromagnetic behaviour of coated conductors (CCs) greatly simplify the design of REBCO-based devices. The performance of REBCO CCs is strongly influenced by fabrication route, conductor architecture and materials, and these parameters vary from one manufacturer to the others. In the present work we have examined the critical surface for the current density, Jc(T,B,θ ), of coated conductors from six different manufacturers: American Superconductor Co. (US), Bruker HTS GmbH (Germany), Fujikura Ltd. (Japan), SuNAM Co. Ltd. (Korea), SuperOx ZAO (Russia) and SuperPower Inc. (US). Electrical transport and magnetic measurements were performed at temperatures between 4.2 K and 77 K and in magnetic field up to 19 T. Experiments were conducted at three different orientations of the field with respect to the crystallographic c-axis of the REBCO layer, θ = 0deg , 45deg and 90deg , in order to probe the angular anisotropy of Jc. In spite of the large variability of CCs performance, ...

  14. Developments of low cost coated conductors by multi-stage CVD process

    Energy Technology Data Exchange (ETDEWEB)

    Kashima, N. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan)], E-mail: Kashima.Naoji@chuden.co.jp; Watanabe, T.; Mori, M.; Suda, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1 Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Miyata, S.; Ibi, A.; Yamada, Y. [ISTEC-SRL, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8567 (Japan); Izumi, T.; Shiohara, Y. [ISTEC-SRL, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2007-10-01

    A low cost and a high-speed production process must be required for a realization of a YBCO coated conductor, especially in the electric power field applications. A multi-stage CVD is one of the most promising processes for manufacturing a coated conductor with a low cost and a high-speed production. Recent progress in developments of long YBCO coated conductors by multi-stage MO-CVD process and their properties would be described. The 203-m-long IBAD substrate (PLD-CeO{sub 2}/IBAD-GZO/HastelloyC) was used for preparing the long YBCO tape. The tape traveling speed at the each passing was 50 m/h and number of passing was 14 times. We applied a 12-stage CVD hot-wall chamber system for preparing YBCO layer. As a result, the end-to-end I{sub c} of 92.8 A (77 K self-field, 1 {mu}V/cm criteria) was obtained. The I{sub c}(A) x L(m) value corresponded to 18.8 kA. The n-value of the tape remained 15.5. Then we measured the I{sub c} distribution for longitudinal direction at 0.5 m intervals. The obtained data showed us that the average I{sub c} was roughly 140-150 A, however, we confirmed some low I{sub c} regions, which is about 65-100 A. The origin of the low I{sub c} regions was summarized. Concerning a high performance YBCO development, we achieved I{sub c} of 294 A/cm by introducing a multi-temperature and composition control process.

  15. Growth of graphene on cylindrical copper conductors as an anticorrosion coating: a microscopic study

    Science.gov (United States)

    Datta, A. J.; Gupta, B.; Shafiei, M.; Taylor, R.; Motta, N.

    2016-07-01

    We have successfully grown graphene film on the surface of cylindrical copper conductors by chemical vapour deposition. The quality and number of graphene layers have been investigated using Raman spectroscopy, Raman mapping and scanning electron microscopy, as a function of methane gas flow rate and of growth temperature. Transmission electron microscopy analysis has been performed to verify the number of graphene layers, confirming the results obtained by Raman spectroscopy. The results open up the possibility of using graphene as an anticorrosion coating for copper cables and earth grids.

  16. Transmission electron microscopy studies of YBCO coated conductor deposited using multiple-stage chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, H. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan)]. E-mail: hisasaki@jfcc.or.jp; Kato, T. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Sasaki, Y. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Hirayama, T. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Kashima, N. [Electric Power Research and Development Center, Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya, Aichi 459-8522 (Japan); Nagaya, S. [Electric Power Research and Development Center, Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya, Aichi 459-8522 (Japan); Izumi, T. [Superconductivity Research Center, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Shiohara, Y. [Superconductivity Research Center, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2005-10-01

    A YBCO film was deposited on Hastelloy tape with highly oriented CeO{sub 2}/Gd{sub 2}Zr{sub 2}O{sub 7} multilayer using multiple-stage chemical vapor deposition. The microstructures of the YBCO coated conductor were examined in detail using transmission electron microscopy. Analysis indicated a YBCO film about 1 {mu}m thick was deposited and consisted mainly of c-axis oriented grains. However, a-axis oriented grains were also observed in the YBCO film, and these a-axis oriented grains grew larger with increasing thickness of the YBCO film.

  17. Characterization and properties of an advanced composite substrate for YBCO-coated conductors

    DEFF Research Database (Denmark)

    Gao, M.; Suo, H.; Zhao, Y.

    2010-01-01

    Thin, biaxially textured Ni5W/Ni12W/Ni5W composite substrates for coated conductor applications have been fabricated. The particularity of this three-layer composite configuration resides in the elemental diffusion between the outer layer and the core layer. Due to the migration of elemental W, t......, the diffusion layer in the as-annealed substrate becomes broader than that of the as-rolled substrate. The obtained tape has a sharp cubic texture on the Ni5W outer layers, and the volume fraction of cubic grains exceeds 98.8% (...

  18. Wind Tunnel Tests on Aerodynamic Characteristics of Ice-Coated 4-Bundled Conductors

    Directory of Open Access Journals (Sweden)

    Li Xin-min

    2017-01-01

    Full Text Available Wind tunnel tests were carried out to obtain the static aerodynamic characteristics of crescent iced 4-bundled conductors with different ice thicknesses, initial ice accretion angles, bundle spaces, and wind attack angles. The test models were made of the actual conductors and have a real rough surface. Test results show that the influence of wake interference on the drag coefficients of leeward subconductors is obvious. The interference angle range is larger than 20° and the drag coefficient curves of leeward subconductors have a sudden decrease phenomenon at some certain wind attack angles. The absolute value of the lift and moment coefficient increases with the increase of the ice thickness. In addition, the galloping of the iced subconductor may occur at the angle of wind attack near ±20° and the wake increases the moment coefficient. The variation of initial ice accretion angle has a significant influence on the aerodynamic coefficients. The aerodynamic coefficient curves exhibit a “moving” phenomenon at different initial ice accretion angles. The bundle spaces have a great influence on the moment coefficient of leeward thin ice-coated conductors. With the increase of ice thickness, the bundle spaces generally have little influence on the aerodynamic coefficients.

  19. Ni–Cu interdiffusion and its implication for ageing in Ni-coated Cu conductors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zijing [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Fang, Le; Cotton, Ian [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); Freer, Robert, E-mail: Robert.Freer@manchester.ac.uk [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom)

    2015-08-15

    Highlights: • Ni–Cu interdiffusion increased the effective resistivity of Ni-coated Cu wires. • Ni–Cu interdiffusion coefficients were determined to be typically 2.5 × 10{sup −17} m{sup 2} s{sup −1}. • Ni–Cu interdiffusion coefficients were dependent on the grain size. • A concentric circle model simulated the diffusion-controlled ageing behaviour. - Abstract: After heat treatment at 400 °C the effective resistivities of typical Ni-coated Cu conductor wires increased by up to 6.9% as a result of Ni–Cu interdiffusion. Direct Ni–Cu interdiffusion experiments were performed between metal foils at temperatures of 400–600 °C for times up to 192 h. Calculated activation energies were in range 80–90 kJ mol{sup −1}, consistent with a grain boundary diffusion mechanism. Analysis of published Ni–Cu interdiffusion coefficients suggested a clear dependence on grain size and grain shape. A concentric circle model was developed to simulate changes in composition and effective resistivity in the Ni–Cu wires as a function of time. It was predicted that it would take 1.4 × 10{sup 5} h at 400 °C for 10% increase in the effective resistivity of an AWG18-Class27 conductor wire. Good agreement between simulated and experimental data for effective resistivity was only achieved by employing effective diffusion coefficients corrected for microstructural effects.

  20. Superconducting layer thickness dependence of magnetic relaxation property in CVD processed YGdBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Y.; Kiuchi, M.; Otabe, E.S. [Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502 (Japan); Matsushita, T., E-mail: matusita@cse.kyutech.ac.jp [Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502 (Japan); Shikimachi, K.; Watanabe, T.; Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan)

    2011-11-15

    One of the most important properties of coated conductors for Superconducting Magnetic Energy Storage (SMES) is the relaxation property of persistent superconducting current. This property can be quantitatively characterized by the apparent pinning potential U{sub 0}{sup *}. In this paper, the dependence of U{sub 0}{sup *} on the thickness of superconducting layer d is investigated in the range of 0.33-1.43 {mu}m at the temperature range of 20-30 K and in magnetic fields up to 6.5 T for Y{sub 0.7}Gd{sub 0.3}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} coated conductors. It was found that the value of critical current density did not appreciably depend on d at 20 K. This indicates that no structural deterioration of superconducting layer occurs during the process of increasing thickness. U{sub 0}{sup *} increases and then tends to decrease with an increasing magnetic field. The magnetic field at which U{sub 0}* starts to decrease increases with increasing thickness. This property was analyzed using the flux creep-flow model. Application of scaling law is examined for the dependence of U{sub 0}{sup *} on magnetic field and temperature. It was found that the dependence could be expressed using scaling parameters (B{sub peak},U{sub 0peak}{sup *}) in the temperature range 20-30 K.

  1. Inhomogeneity effects in HTS coated conductors used as resistive FCLs in medium voltage grids

    Science.gov (United States)

    Colangelo, Daniele; Dutoit, Bertrand

    2012-09-01

    For resistive fault current limiters (RFCLs) based on high temperature superconducting coated conductors (HTS-CCs), inhomogeneity, in terms of critical current and geometrical imperfections such as stabilizer and substrate thicknesses, plays a very important role and it may limit the penetration of such devices into the electrical market. This paper presents an electrothermal model, developed in SimPowerSystem™, able to describe the transient response of HTS-CC candidates with different degrees of inhomogeneity, both in terms of critical current and of stabilizer thickness. Critical current inhomogeneity has been modeled with Gaussian distributions. The layer thicknesses used in the simulations have been chosen by fitting the temperature dependence of real tape resistances. Our approach considers relative inhomogeneity positions as well as thermal conduction along the HTS-CC length. The model is tuned using experimental measurements made on ReBaCuO coated conductors. A new dynamical thermal calibration of the model is proposed using finite element method calculations. Inhomegeneity effects with different possible faults (e.g. three phase and single phase short-circuit) are presented.

  2. Reel-to-reel preparation of ion-beam assisted deposition (IBAD)-MgO based coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Kreiskott, Sascha; Arendt, Paul N; Coulter, J Yates; Dowden, Paul C; Foltyn, Stephen R; Gibbons, Brady J; Matias, Vladimir; Sheehan, Chris J [Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2004-05-01

    We report on our efforts in developing and scaling-up the systems for IBAD-MgO based coated conductor fabrication. The overall fabrication process involves a number of different processes including: electropolishing of the substrates; barrier-layer, seed-layer, and IBAD-MgO deposition by e-beam evaporation; and pulsed laser deposition of buffer and YBCO layers. All processes are realized in reel-to-reel processing systems. Latest results have shown that the IBAD-MgO approach yields coated conductor performance comparable to the best results achieved elsewhere to date.

  3. Architecture and Assembly of the Bacillus subtilis Spore Coat

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  4. Architecture and assembly of the Bacillus subtilis spore coat.

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of "nanodot" particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  5. 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...

  6. Test results of 12/18 kA ReBCO coated conductor current leads

    Science.gov (United States)

    Kovalev, I. A.; Surin, M. I.; Naumov, A. V.; Novikov, M. S.; Novikov, S. I.; Ilin, A. A.; Polyakov, A. V.; Scherbakov, V. I.; Shutova, D. I.

    2017-07-01

    A pair of hybrid current leads (brass + stacked & soldered ReBCO tapes) rated for 12 kA in steady state and for up to 18 kA at pulsed over current conditions was designed, developed and tested at NRC ;Kurchatov Institute; (NRC ;KI;). During the experiment at LN2 temperature, the current leads (CLs) were successfully charged with 18 kA at 100 A/s ramp rate. To date, as far as we know, this is the highest current capacity achieved for 2G HTS current leads. The feasibility of ;stack-and-soldering technique; for 10 kA+ class coated conductor CLs for accelerators and fusion was demonstrated. This paper gives an overview of the leads design and presents the preliminary test results. Detailed studies of magnetic properties and current sharing process for the stacked and staggered HTS joints are also reported.

  7. Design study of coated conductor direct drive wind turbine generator for small scale demonstration

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Jensen, Bogi Bech

    2012-01-01

    We have investigated the properties of a superconducting direct drive generator suitable for demonstration in a small scale 11 kW wind turbine. The engineering current density of the superconducting field windings is based on properties of coated conductors wound into coils holding of the order 68...... meters of tape. The active mass of the generators has been investigated as function of the number of poles and a 4 pole generator is suggested as a feasible starting point of an in-field demonstration of the system reliability. An active mass of m = 421 kg and a usage of 3.45 km of tape will be needed...... to realize such a generator with a peak flux density in the airgap of B0 = 1.5 T. © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Guest Editors....

  8. Mechanical and transport properties of IBAD/EDDC-SmBCO coated conductor tapes during fatigue loading

    Science.gov (United States)

    Shin, Hyung-Seop; Dedicatoria, Marlon J.

    2011-06-01

    In electrical devices like superconducting motor, generator and SMES, HTS coated conductor (CC) tapes will be subjected to alternating stress or strain during manufacturing and operation. The repeated loading will affect the mechanical integrity and eventually the electrical transport property of CC tapes. Therefore in such applications, electro-mechanical property of CC tapes should be evaluated. In this study, the endurance of an IBAD/EDDC-SmBCO CC tape under high-cycle fatigue loading has been evaluated. Applied maximum stress and fatigue life ( S-N) relation was obtained at 77 K. The mechanical properties and the critical current, I c, of the sample under fatigue loading were investigated at 77 K. Considering the practical operating environment, the effect of the stress ratio R, on the degradation behavior of I c under fatigue loading was also examined.

  9. Doubling the critical current density of high temperature superconducting coated conductors through proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Y.; LeRoux, M.; Miller, D. J.; Wen, J. G.; Kwok, W. K.; Welp, U. [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States); Rupich, M. W.; Li, X.; Sathyamurthy, S.; Fleshler, S.; Malozemoff, A. P. [American Superconductor Corp., 64 Jackson Road, Devens, Massachusetts 01434 (United States); Kayani, A. [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Ayala-Valenzuela, O.; Civale, L. [Los Alamos National Laboratory, MS-K764, Los Alamos, New Mexico 87545 (United States)

    2013-09-16

    The in-field critical current of commercial YBa{sub 2}Cu{sub 3}O{sub 7} coated conductors can be substantially enhanced by post-fabrication irradiation with 4 MeV protons. Irradiation to a fluence of 8 × 10{sup 16} p/cm{sup 2} induces a near doubling of the critical current in fields of 6 T || c at a temperature of 27 K, a field and temperature range of interest for applications, such as rotating machinery. A mixed pinning landscape of preexisting precipitates and twin boundaries and small, finely dispersed irradiation induced defects may account for the improved vortex pinning in high magnetic fields. Our data indicate that there is significant head-room for further enhancements.

  10. Development of Solution Buffer Layers for RABiTS Based YBCO Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, Mariappan Parans [ORNL; Qiu, Xiaofeng [ORNL; List III, Frederick Alyious [ORNL; Zhang, Yifei [ORNL; Li, Xiaoping [American Superconductor Corporation, Westborough, MA; Sathyamurthy, Srivatsan [ORNL; Thieme, C. L. H. [American Superconductor Corporation, Westborough, MA; Rupich, M. W. [American Superconductor Corporation, Westborough, MA

    2011-01-01

    Abstract The main objective of this research is to find a suitable alternate solution based seed layer for the standard RABiTS three-layer architecture of physical vapor deposited CeO cap/YSZ barrier/Y O seed on Ni-5%W metal tape. In the present work, we have identified CeO buffer layer as a potential replacement for Y O seeds. Using a metal-organic deposition (MOD) process, we have grown smooth, crack-free, epitaxial thin films of CeO (pure and Zr, Cu and Gd-doped) directly on biaxially textured Ni-5W substrates in short lengths. Detailed XRD studies indicate that a single epitaxial CeO phase with slightly improved out-of-plane texture compared to the texture of the underlying Ni-W substrates can be achieved in pure, undoped CeO samples. We have also demonstrated the growth of YSZ barrier layers on pure CeO seeds using sputtering. Both sputtered CeO cap layers and MOD-YBCO films were grown epitaxially on these YSZ-buffered MOD-CeO /Ni-5W substrates. High critical currents per unit width, of 264 A/cm (critical current density, of 3.3 MA/cm ) at 77 K and 0.01 T was achieved for 0.8 m thick MOD-YBCO films grown on MOD-CeO seeds. These results indicate that CeO films can be grown directly on Ni-5W substrates and still support high performance YBCO coated conductors. This work holds promise for a route for producing low-cost buffer architecture for RABiTS based YBCO coated conductors.

  11. Development of Solution Buffer Layers for RABiTS Based YBCO Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, Mariappan Parans [ORNL; Qiu, Xiaofeng [ORNL; Kim, Kyunghoon [ORNL; Shi, D. [University of Cincinnati; Zhang, Yifei [ORNL; Li, Xiaoping [American Superconductor Corporation, Westborough, MA; Sathyamurthy, Srivatsan [ORNL; Thieme, C. L. H. [American Superconductor Corporation, Westborough, MA; Rupich, M. W. [American Superconductor Corporation, Westborough, MA

    2010-01-01

    The main objective of this research is to find a suitable alternate solution based seed layer for the standard RABiTS three-layer architecture of physical vapor deposited CeO2 cap/YSZ barrier/Y2O3 seed on Ni-5%W metal tape. In the present work, we have identified CeO2 buffer layer as a potential replacement for Y2O3 seeds. Using a metal-organic deposition (MOD) process, we have grown smooth, crack-free, epitaxial thin films of CeO2 (both pure and Zr, Cu and Gd-doped) directly on biaxially textured Ni-5W substrates in short lengths. Detailed XRD studies indicate that a single epitaxial CeO2 phase with slightly improved out-of-plane texture compared to the texture of underlying Ni-W substrates can be achieved in pure, undoped CeO2 samples. We have also demonstrated the growth of YSZ barrier layers on pure CeO2 seeds using sputtering. Both sputtered CeO2 cap layers and MOD-YBCO films were grown epitaxially on these YSZ-buffered MOD-CeO2/Ni-5W substrates. High critical currents per unit width, Ic of 264 A/cm (critical current density, Jc of 3.3 MA/cm2) at 77 K and 0.01 T was achieved for 0.8 m thick MOD-YBCO films grown on MOD-CeO2 seeds. These results indicate that CeO2 films can be grown directly on Ni-5W substrates and still support high performance YBCO coated conductors. This work holds promise for a route for producing low-cost buffer architecture for RABiTS based YBCO coated conductors.

  12. Development of a laser scribing process of coated conductors for the reduction of AC losses

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K [Superconductivity Research Laboratory, ISTEC, Division of Superconducting Tapes and Wires, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Matsuda, J [Superconductivity Research Laboratory, ISTEC, Division of Superconducting Tapes and Wires, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Yoshizumi, M [Superconductivity Research Laboratory, ISTEC, Division of Superconducting Tapes and Wires, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Izumi, T [Superconductivity Research Laboratory, ISTEC, Division of Superconducting Tapes and Wires, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Shiohara, Y [Superconductivity Research Laboratory, ISTEC, Division of Superconducting Tapes and Wires, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Iwakuma, M [Research Institute of Superconductor Science and Systems, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Ibi, A [Superconductivity Research Laboratory, ISTEC, Nagoya Coated Conductor Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Miyata, S [Superconductivity Research Laboratory, ISTEC, Nagoya Coated Conductor Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Yamada, Y [Superconductivity Research Laboratory, ISTEC, Nagoya Coated Conductor Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan)

    2007-08-15

    Expectations are high for using coated conductors for electric power applications not only because of better cost performance but also higher J{sub c}-B properties compared with Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} (BSCCO) tapes. Furthermore, the coated conductors could also reduce AC losses by the use of various methods in post-treatment. When a YAG laser was used for scribing the superconductive layer, an AC loss reduction due to a decrease in the width of the superconductivity layer could be confirmed in short samples. In the case of AC applications using long tapes, high resistance between scribed filaments is necessary. However, the resistance between the filaments scribed by a laser was as low as 10{sup -3} {omega} cm{sup -1}. The reason for the low resistance was the existence of dross in the filament spacings, which was confirmed by a cross-sectional compositional mapping observation. Although the superconductivity layer was divided by the laser, the dross of the metal substrate made a bridge over the superconductivity filaments. Post-annealing in an O{sub 2} atmosphere to oxidize the dross was carried out in order to increase the resistance. Consequently, the resistance between the filaments was improved to be as high as 50 {omega} cm{sup -1}. We succeeded in controlling the resistance value between filaments in a range five orders of magnitude higher than that of the as-scribed YBCO film, through oxygen atmosphere post-annealing.

  13. Modified Lanthanum Zirconium Oxide buffer layers for low-cost, high performance YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Parans Paranthaman, M., E-mail: paranthamanm@ornl.go [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Sathyamurthy, S.; Li, Xiaoping [American Superconductor Corporation, Devens, MA 01434 (United States); Specht, E.D.; Wee, S.H.; Cantoni, C.; Goyal, A. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Rupich, M.W. [American Superconductor Corporation, Devens, MA 01434 (United States)

    2010-03-01

    The pyrochlore Lanthanum Zirconium Oxide, La{sub 2}Zr{sub 2}O{sub 7} (LZO), has been developed as a potential replacement barrier layer in the standard RABiTS three-layer architecture of physical vapor deposited CeO{sub 2} cap/YSZ barrier/Y{sub 2}O{sub 3} seed on Ni-5%W metal tape. The main focus of this research is to ascertain whether: (i) we can further improve the barrier properties of LZO; (ii) we can modify the LZO cation ratio and still achieve a high level of performance; and (iii) it is possible to reduce the number of buffer layers. We report a systematic investigation of the LZO film growth with varying compositions of La:Zr ratio in the La{sub 2}O{sub 3}-ZrO{sub 2} system. Using a metal-organic deposition (MOD) process, we have grown smooth, crack-free, epitaxial thin films of La{sub x}Zr{sub 1-x}O{sub y} (x = 0.2-0.6) on standard Y{sub 2}O{sub 3} buffered Ni-5W substrates in short lengths. Detailed XRD studies indicate that a single epitaxial LZO phase with only (0 0 1) texture can be achieved in a broad compositional range of x = 0.2-0.6 in La{sub x}Zr{sub 1-x}O{sub y}. Both CeO{sub 2} cap layers and MOD-YBCO films were grown epitaxially on these modified LZO barriers. High critical currents per unit width, I{sub c} of 274-292 A/cm at 77 K and self-field were achieved for MOD-YBCO films grown on La{sub x}Zr{sub 1-x}O{sub y} (x 0.4-0.6) films. These results indicate that LZO films can be grown with a broad compositional range and still support high performance YBCO coated conductors. In addition, epitaxial MOD La{sub x}Zr{sub 1-x}O{sub y} (x = 0.25) films were grown directly on biaxially textured Ni-3W substrates. About 3 mum thick YBCO films grown on a single MOD-LZO buffered Ni-3W substrates using pulsed laser deposition show a critical current density, J{sub c}, of 0.55 MA/cm{sup 2} (I{sub c} of 169 A/cm) at 77 K and 0.01 T. This work holds promise for a route for producing simplified buffer architecture for RABiTS based YBCO coated conductors.

  14. Modified Lanthanum Zirconium Oxide Buffer for Low-Cost, High Performance YBCO Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, Mariappan Parans [ORNL; Sathyamurthy, Srivatsan [ORNL; Li, Xiaoping [American Superconductor Corporation, Westborough, MA; Specht, Eliot D [ORNL; Wee, Sung Hun [ORNL; Cantoni, Claudia [ORNL; Goyal, Amit [ORNL; Rupich, M. W. [American Superconductor Corporation, Westborough, MA

    2010-01-01

    Lanthanum Zirconium Oxide, La2Zr2O7 (LZO) has been developed as a potential replacement barrier layer in the standard RABiTS three-layer architecture of physical vapor deposited CeO2 cap/YSZ barrier/Y2O3 seed/Ni-5W. The main focus of this research is to see (i) whether we can improve further the barrier properties of LZO; (ii) can we widen the LZO composition and still achieve the high performance?; and (iii) is it possible to reduce the number of buffer layers? We report a systematic investigation of the LZO film growth with varying compositions of La:Zr ratio in the La2O3-ZrO2 system. Using metal-organic deposition (MOD) process, we have grown smooth, crack-free, epitaxial thin films of LaxZr1-xOy (x = 0.2-0.6) on standard Y2O3 buffered Ni-5W substrates in short lengths. Detailed XRD studies indicate that a single epitaxial LZO phase without the (111) texture can be achieved in a wider compositional window of x = 0.2-0.6 in LaxZr1-xOy. Both CeO2 cap layers and MOD-YBCO films were grown 2 epitaxially on these modified LZO barriers. Transport property measurements indicate that we can achieve a higher critical current, Ic of 274-292 A/cm at 77 K and self-field on MOD-YBCO films grown on LaxZr1-xOy (x = 0.4-0.6) films. These results indicate that LZO films can be grown with a wider compositional window and still achieve high performance YBCO coated conductors. In addition, epitaxial MOD LaxZr1-xOy (x = 0.25) films were grown directly on biaxially textured Ni-3W substrates. About 3 m thick YBCO films with a Jc of 0.55 MA/cm2 at 77 K and 0.01 T were grown on a single MOD LZO buffered Ni-3W substrate using pulsed laser deposition. This work promises a route for producing simplified buffer architecture for RABiTS based YBCO coated conductors.

  15. Development of 6.6 kV/600 A superconducting fault current limiter using coated conductors

    Science.gov (United States)

    Yazawa, T.; Koyanagi, K.; Takahashi, M.; Toba, K.; Takigami, H.; Urata, M.; Iijima, Y.; Saitoh, T.; Amemiya, N.; Shiohara, Y.; Ito, T.

    2009-10-01

    As one of the programs in the Ministry of Economy, Trade and Industry (METI) project regarding R&D on superconducting coated conductor, three-phase superconducting fault current limiter (SFCL) for 6.6 kV application was developed and successfully tested. The developed SFCL was mainly comprised three-phase set of current limiting coils installed in a sub-cooled nitrogen cryostat with a GM cryocooler, circuit breakers and a sequence circuit. The whole system was installed in a cubicle. Two tapes of coated conductor were wound in parallel in each coil to obtain the rated current of 72 A rms. After developing the whole SFCL system, short circuit experiments were implemented with a short circuit generator. In a three-line ground fault test, the SFCL successfully restricted the prospected short circuit current over 1.6 kA to about 800 A by the applied voltage of 6.6 kV. The SFCL was installed in a user field and connected with a gas engine generator, followed by a consecutive operation. In this program, 600 A class FCL coil, with which four coated conductor tapes were wound, was also developed. The coil showed sufficiently low AC loss at the rated current. With these results, the program attained the planned target of the fundamentals for the 6.6 kV/600 A SFCL.

  16. Dependence of superconducting layer thickness on critical current density of IBAD/CVD-processed YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Himeki, K.; Kiuchi, M.; Otabe, E.S. [Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502 (Japan); Matsushita, T., E-mail: matusita@cse.kyutech.ac.j [Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka 820-8502 (Japan); Shikimachi, K.; Watanabe, T.; Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Yamada, Y.; Shiohara, Y. [Superconductivity Research Laboratory, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2009-10-15

    The thickness dependence of the critical current characteristics was investigated for YBa{sub 2}Cu{sub 3}O{sub 7-d}elta (YBCO) coated conductors fabricated by Ion Beam Assist Deposition (IBAD)/Chemical Vapor Deposition (CVD) method in the range of 0.18-0.90 mum to find out the optimum thickness for various applications. The transport and magnetization critical current densities were estimated using the electric field criterion of E{sub c} = 1.0 x 10{sup -4} V/m and E{sub c} = 1.0 x 10{sup -9} V/m, respectively. The critical current density decreased with increase thickness in the low magnetic field region in the both electric field region because of the structural degradation of superconducting layer. This decreasing rate was lower than in Pulsed Laser Deposition (PLD)-processed YBCO coated conductors. It is found that the thickness dependence of irreversibility field B{sub i} differed between the low and normal electric field region. In the low electric field region, B{sub i} increased with increasing thickness. On the other hand, B{sub i} is almost independent of the thickness in the normal electric field region. The thickness dependence of B{sub i} was also superior to that of PLD-processed YBCO coated conductors.

  17. Solution Processed Lanthanum Zirconium Oxide as a Primary Barrier Layer for High Ic Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Sathyamurthy, Srivatsan [ORNL; Paranthaman, Mariappan Parans [ORNL; Heatherly Jr, Lee [ORNL; Martin, Patrick M [ORNL; Specht, Eliot D [ORNL; Goyal, Amit [ORNL; Kodenkandath, Thomas [American Superconductor Corporation, Westborough, MA; Li, Xiaoping [American Superconductor Corporation, Westborough, MA; Rupich, Marty [American Superconductor Corporation, Westborough, MA

    2006-01-01

    High-quality lanthanum zirconium oxide (La{sub 2}Zr{sub 2}O{sub 7} or LZO) films have been deposited and processed on Ni-W substrates using a sol-gel processing approach. It has been demonstrated that crack-free coatings with thicknesses up to 100 nm can be processed in a single step, while thicker coatings (200-225 nm) were processed using a multiple coating and annealing process. Using simulated metalorganic deposition (MOD)-YBa{sub 2}Cu{sub 3}O{sub 7-:{angstrom}} (YBCO) processing conditions, the barrier properties of the sol-gel LZO coating with a thickness of 120 nm were found to be comparable to that of the standard 3-layer buffer stack deposited using physical vapor deposition. Secondary ion mass spectroscopy depth profile analysis of LZO films annealed in oxygen-18 shows that LZO effectively stops the diffusion of Ni within the first 80-100 nm. Using MOD processes, a CeO{sub 2} cap layer and superconducting YBCO layer were deposited on sol-gel LZO/Ni-W. For the first time, using such an all-solution conductor architecture, a critical current (I{sub c}) of 140 A/cm with a corresponding critical current density (J{sub c}) of 1.75 MA/cm{sup 2} has been demonstrated. Using a very thin Y{sub 2}O{sub 3} seed layer ({approx}10 nm) deposited by electron beam evaporation; improved texture quality in the LZO layers has been demonstrated. The performance of the LZO deposited on these samples was evaluated using a sputtered CeO{sub 2} cap layer and MOD YBCO layer. Critical currents of up to 255 A/cm (3.2 MA/cm{sup 2}) with 0.8-{micro}m-thick YBCO films have been demonstrated, comparable to the performance of films grown using physical vapor deposited yttria stabilized zirconia as a barrier layer. Similar experiments using an MOD-CeO{sub 2} cap layer and MOD-YBCO layer yielded critical currents of 200 A/cm (2.5 MA/cm{sup 2}) with 0.8-{micro}m-thick YBCO films.

  18. Materials design for artificial pinning centres in superconductor PLD coated conductors

    Science.gov (United States)

    Feighan, J. P. F.; Kursumovic, A.; MacManus-Driscoll, J. L.

    2017-12-01

    To date the strategy for inducing pinning in REBa2Cu3O7‑x (REBCO where RE = rare-earth) coated conductors has largely been empirical. Hence, we are not yet at a point where we can dial-in the compositions and process parameters to optimise pinning for particular applications having specific temperature, field, and field angle requirements. In this review, we cover the critical materials science aspects which enable the understanding, design and engineering of desired pinning centre morphologies. Our main emphasis is on in in situ epitaxial growth of REBCO films by vapour deposition. We review the optimal pinning centre morphologies which have been determined to be effective for different operation regimes. We also highlight how the interplay of thermodynamics (including epitaxial effects), film-particle interfacial strain, and kinetics determine pinning morphologies. Finally, we also briefly cover pinning in rapid ex situ, liquid assisted growth which is likely to be a necessary universal approach for applications where low cost is critical.

  19. Future prospects of high Tc superconductors-coated conductors and their applications

    Science.gov (United States)

    Shiohara, Yuh; Yoshizumi, Masateru; Takagi, Yuji; Izumi, Teruo

    2013-01-01

    The research and development of high-temperature superconducting wires, especially yttrium-based coated conductors (CCs), and their energy applications have been expected to reduce CO2 emissions. This article reviews recent progress in this area, mainly focusing on the results obtained by national projects in Japan. The Ic (critical current) × L (wire length) value of CCs has been improved to reach 466,752 A m (572 A/cm-W, 816 m), which exceeds that of Bi-system wires. CCs have also been improved in terms of in-field performance and AC loss reduction to meet market requirements. Power applications such as superconducting magnetic energy storage (SMES) systems, power cables and transformers have been developed using CCs in the current project. Because of fundamental research on high-capacity power cables, a low AC loss of 0.8 W/m-ph at 3 kA and 73.7 K was achieved. System design and fundamental research were performed on a 2GJ-class SMES system and a 20 MVA-class transformer. Based on the technologies developed by the end of the current project (FY2012), the innovation process of those applications will reach the implementation stage, where the long-term reliability tests will be performed. The process is expected to reach the penetration and propagation stage around 2020.

  20. High critical current density in YBCO coated conductors prepared by thermal co-evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Bindi, M [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy); Botarelli, A [Europa Metalli SpA, Superconductor Division, via Repubblica 257, I-55052 Fornaci di Barga, Lucca (Italy); Gauzzi, A [IMEM-CNR, Area delle Scienze 37/A, I-43010 Parma (Italy); Gianni, L [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy); Ginocchio, S [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy); Holzapfel, B [Institut fuer Festkoerper-und Werkstoffsforschung, Helmholtzstrasse 20, Dresden (Germany); Baldini, A [Europa Metalli SpA, Superconductor Division, via Repubblica 257, I-55052 Fornaci di Barga, Lucca (Italy); Zannella, S [Edison Termoelettrica SpA, Foro Buonaparte 31, I-20121 Milan (Italy)

    2004-03-01

    We report on the in situ preparation of Y Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} films uniformly deposited over large areas,>20 x 20 cm{sup 2}, at 690 C by thermal co-evaporation onto Ni-5 at.% W biaxially textured tapes buffered with e-beam evaporated CeO{sub 2}. Typically, the thickness of the YBCO and CeO{sub 2} layers was 0.9 and 0.1 {mu}m, respectively. Deposition rates were 0.2 and 2.5 nm s{sup -1}, respectively. X-ray diffraction {theta}-2{theta} Bragg-Brentano and pole figure measurements, and Nomarsky optical and SEM microscopy analysis show good biaxial texture of both layers, sharp interfaces and the absence of cracks. Midpoint critical temperatures, T{sub c}, fall reproducibly in the 87-88 K range with transition widths {delta}T{sub c} = 1 K. Remarkably high transport critical current densities, J{sub c}, in the 2.0-2.5 MA cm{sup -2} range are achieved at 77 K in 1 cm long samples. The above deposition route appears to be promising for the development of long-length YBCO coated conductors thanks to the relatively low deposition temperature, the high degree of uniformity over large areas and the simple single buffer layer architecture.

  1. Voltage-ampere characteristics of YBCO coated conductor under inhomogeneous oscillating magnetic field

    Science.gov (United States)

    Geng, J.; Shen, B.; Li, C.; Zhang, H.; Matsuda, K.; Li, J.; Zhang, X.; Coombs, T. A.

    2016-06-01

    Direct current carrying type II superconductors present a dynamic resistance when subjected to an oscillating magnetic field perpendicular to the current direction. If a superconductor is under a homogeneous field with high magnitude, the dynamic resistance value is nearly independent of transport current. Hoffmann and coworkers [Hoffmann et al., IEEE Trans. Appl. Supercond. 21, 1628 (2011)] discovered, however, flux pumping effect when a superconducting tape is under an inhomogeneous field orthogonal to the tape surface generated by rotating magnets. Following their work, we report the whole Voltage-Ampere (V-I) curves of an YBCO coated conductor under permanent magnets rotating with different frequencies and directions. We discovered that the two curves under opposite rotating directions differ from each other constantly when the transport current is less than the critical current, whereas the difference gradually reduces after the transport current exceeds the critical value. We also find that for different field frequencies, the difference between the two curves decreases faster with lower field frequency. The result indicates that the transport loss is dependent on the relative direction of the transport current and field travelling, which is distinct from traditional dynamic resistance model. The work may be instructive for the design of superconducting motors.

  2. New chemical approach to obtain dense layer phosphate-based ionic conductor coating on negative electrode material surface: Synthesis way, outgassing and improvement of C-rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Fleutot, Benoit, E-mail: benoit.fleutot@u-picardie.fr [Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33 rue Saint Leu, 80039 Amiens (France); Réseau sur le Stockage Electrochimique de l’Energie (RS2E), CNRS FR3459 (France); Davoisne, Carine; Gachot, Grégory; Cavalaglio, Sébastien; Grugeon, Sylvie; Viallet, Virginie [Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33 rue Saint Leu, 80039 Amiens (France); Réseau sur le Stockage Electrochimique de l’Energie (RS2E), CNRS FR3459 (France)

    2017-04-01

    Highlights: • Dense layer coating of based-phosphate ionic conductor obtained by spray-drying. • Influence of dense ionic conductor at the negative surface material on performances. • Impact of dense ionic conductor coating on outgassing phenomena. - Abstract: Li{sub 4}Ti{sub 5}O{sub 12} (LTO) based batteries have severe gassing behavior during charge/discharge and storage process, due to interfacial reactions between active material and electrolyte solution. In the same time, the electronic and ionic conductivity of pristine LTO is very poor and induces the use of nanoparticles which increase the outgassing phenomena. The coating of LTO particles could be a solution. For this the LTO spinel particles are modified with ionic conductor Li{sub 3}PO{sub 4} coating using a spray-drying method. For the first time a homogeneous thin dense layer phosphate based conductor is obtained without nanoparticles, as a thin film material. It is so possible to study the influence of ionic conductor deposited on the negative electrode material on performances by the controlled layer thickness. This coating was characterized by XRD, SEM, XPS and TEM. The electrochemical performance of Li{sub 3}PO{sub 4} coated Li{sub 4}Ti{sub 5}O{sub 12} is improved at high C-rate by the surface modification (improvement of 30 mAh g{sup −1} at 5 C-rate compared to pristine LTO for 5 nm of coating), inducing by a modification of surface energy. An optimum coating thickness was studied. This type of coating allows a significant decrease of outgassing phenomena due the conformal coating and opens the way to a great number of studies and new technologies.

  3. Architecture and Assembly of the Bacillus subtilis Spore Coat

    Science.gov (United States)

    2014-09-26

    1ITLE AND SUBTITLE 5a CONTRACTNUMBER Architecture and assembly of the Bacillus subtilis spore coat W911NF-09-l-0286 5b. GRANT NUMBER 5c. PROGRAM...ABSTRACT In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild-type and cotA, cotB, safA, cotH...Std. Z39.18 ABSTRACT Architecture and assembly of the Bacillus subtilis spore coat Report Title In this study, atomic force microscopy was used to

  4. Critical current property in YBCO coated conductor fabricated by improved TFA-MOD process

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, M., E-mail: inoue@ees.kyushu-u.ac.j [Department of EESE, Kyushu University, Moto-oka 744, NIshi-ku, Fukuoka 819-0395 (Japan); Kiss, T.; Motoyama, K. [Department of EESE, Kyushu University, Moto-oka 744, NIshi-ku, Fukuoka 819-0395 (Japan); Awaji, S.; Watanabe, K. [Institute for Materials, Tohoku University, Sendai 980-8577 (Japan); Yoshizumi, M.; Yamada, Y.; Izumi, T.; Shiohara, Y. [Superconductivity Research Laboratory, Tokyo 135-0062 (Japan)

    2009-10-15

    We have investigated critical current property in YBa{sub 2}Cu{sub 3}O{sub 7-d}elta (YBCO) coated conductor fabricated by improved metal organic deposition using trifluoroacetates (TFA-MOD) process optimizing conditions such as solution compositions. The electric field vs. current density (E-J) characteristic measurement was carried out at wide range of temperature, T, and magnetic field, B. Critical current density, J{sub c}, reached 3.8 x 10{sup 10} A/m{sup 2} at 77 K in self-field for 1.2 mum thick YBCO layer. In-field J{sub c} is also improved by this new process. From the analysis of E-J characteristics, we have found out that the shape of statistical distribution of J{sub c} in the new process becomes sharper than that of the previous one. These results indicate that the uniformity of YBCO layer is improved by the new process. Furthermore, analytical expression of E-J characteristics, which is based on a percolation model and a scaling law of the pinning force density, shows good agreement with the experimental results. This allows us to predict the critical current property at arbitrary conditions of T and B even if we could not have measured data. For example, it is predicted that J{sub c} could be about 1 x 10{sup 10} A/m{sup 2} at 4.2 K and 30 T parallel to the c-axis.

  5. High J {sub c} coated conductors with a simple buffer layer architecture

    Energy Technology Data Exchange (ETDEWEB)

    Gianni, L. [Edison S.p.A., Foro Buonaparte 31, I-20121 Milan (Italy)]. E-mail: lgianni@imem.cnr.it; Baldini, A. [Outokumpo Copper Superconductors Italy, I-55052 Fornaci di Barga (Italy); Bindi, M. [Edison S.p.A., Foro Buonaparte 31, I-20121 Milan (Italy); Gauzzi, A. [IMEM-CNR, Area delle Scienze 37/A, I-43010 Parma (Italy); Rampino, S. [IMEM-CNR, Area delle Scienze 37/A, I-43010 Parma (Italy); Zannella, S. [Edison S.p.A., Foro Buonaparte 31, I-20121 Milan (Italy)

    2005-10-01

    We report on the in situ route for the continuous fabrication of YBCO coated conductors (CC) by thermal co-evaporation. CC architecture consists of YBCO film grown on biaxially textured Ni-alloys tapes buffered with a single layer of CeO{sub 2}. The buffer layer deposition has been optimized by either e-beam or thermal evaporation using respectively ceria or metallic cerium. Best results have been obtained on CeO{sub 2} film, with a thickness less or equal than 100 nm, grown in a reducing atmosphere at 690 deg. C with a growth rate of 2.4 A/s. The optimal samples exhibit a highly biaxial texture, as indicated by FWHM values in the range of 5-8 deg. and 4-6 deg. for respectively in- and out-of-plane orientations. The layers are characterized by an uniform and crack-free surface with an average roughness lower than 10 nm. SIMS analysis confirms the effectiveness of CeO{sub 2} buffer layer against Ni interdiffusion. This template allows to obtain YBCO films strong textured, with good superconductive properties. YBCO texture data are equivalent the CeO{sub 2} ones. Midpoint critical temperature, T {sub c}, falls reproducibly in 87-88 K range, with transition widths {delta}T {sub c} < 2-3 K. Critical current density, J {sub c}, up to 2 MA/cm{sup 2} at 77 K in self-field, have been achieved in a meter long CC corresponding to I {sub c}/width value of 130 A/cm-width. Uniformity and reproducibility of long CC properties are under optimization.

  6. Note: Effective anvil size for transverse delamination test of rare-earth-Ba₂Cu₃Oy coated conductor tapes.

    Science.gov (United States)

    Shin, Hyung-Seop; Gorospe, Alking B; Dedicatoria, Marlon J

    2015-10-01

    In coated conductor (CC) tapes used in magnet and coil applications, delamination due to excessive transverse tensile stresses is still one of the major issues that need considerations. Recently, several methods in evaluating the delamination strength of CC tapes are being used. In the case of anvil test, size of the anvils will be an important factor considering its applications (i.e., superconducting coil impregnation). In this study, delamination strength of CC tape was examined using different upper anvil sizes and their effects were discussed. Finally, reasonable sizes of upper anvil to be used were proposed considering the application conditions.

  7. Fabrication, microstructure and persistent current measurement of an intermediate grown superconducting (iGS) joint between REBCO-coated conductors

    Science.gov (United States)

    Ohki, K.; Nagaishi, T.; Kato, T.; Yokoe, D.; Hirayama, T.; Ikuhara, Y.; Ueno, T.; Yamagishi, K.; Takao, T.; Piao, R.; Maeda, H.; Yanagisawa, Y.

    2017-11-01

    A superconducting joint technology used for high-temperature superconductors (HTS) is the key for enabling persistent operation of HTS magnets. In the present work, we have succeeded in developing a superconducting joint between REBCO-coated conductors (CCs) using a joint strap with a microcrystalline GdBCO precursor intermediate layer. Heat treatment and oxygen annealing, with a total processing time of less than 1 d, grows a biaxially-textured intermediate layer to connect the GdBCO layers in the CCs. Microstructure observation of a part of the joint cross-section with SEM and TEM showed that the intermediate layer and the GdBCO layers in the conductors were atomically connected. An electron backscatter diffraction result showed that both the c- and a-axis misorientations among the GdBCO layers of the joined conductor and the GdBCO layer of the joint strap were about less than 5°. This intermediate grown superconducting joint gives a critical current of >100 A at 77 K in a self-field. A critical current of a joint at 4.2 K in a self-field is seven times higher than that at 77 K. The persistent field decay of a small double pancake coil, terminated with this joint, showed a joint resistance in the range of MRI.

  8. Bacillus atrophaeus Outer Spore Coat Assembly and Ultrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Plomp, M; Leighton, T J; Wheeler, K E; Pitesky, M E; Malkin, A J

    2005-11-21

    Our previous atomic force microscopy (AFM) studies successfully visualized native Bacillus atrophaeus spore coat ultrastructure and surface morphology. We have shown that the outer spore coat surface is formed by a crystalline array of {approx}11 nm thick rodlets, having a periodicity of {approx}8 nm. We present here further AFM ultrastructural investigations of air-dried and fully hydrated spore surface architecture. In the rodlet layer, planar and point defects, as well as domain boundaries, similar to those described for inorganic and macromolecular crystals, were identified. For several Bacillus species, rodlet structure assembly and architectural variation appear to be a consequence of species-specific nucleation and crystallization mechanisms that regulate the formation of the outer spore coat. We propose a unifying mechanism for nucleation and self-assembly of this crystalline layer on the outer spore coat surface.

  9. Iridium: An Oxygen Diffusion Barrier and a Conductive Seed Layer for RABiTS-Based Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL; Paranthaman, Mariappan Parans [ORNL; Zhai, Hong-Ying [ORNL; Leonard, Keith J [ORNL; Gapud, Albert Agcaoili [ORNL; Thompson, James R [ORNL; Martin, Patrick M [ORNL; Goyal, Amit [ORNL; Christen, David K [ORNL

    2005-01-01

    For power applications of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) coated conductors, it is necessary to electrically stabilize the conductor. An economic way to achieve this, which also benefits the engineering J{sub E}, is to grow conductive buffer layers directly on textured Cu or Ni metal surfaces. However, due to poor oxidation resistance and high reactivity/diffusivity of Cu or Ni, an insulating oxide layer usually forms at the metal/substrate interface, degrading the electrical connectivity of the entire architecture. To overcome this problem, we have developed a new conductive, nonmagnetic buffer layer architecture of La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/Ir on textured Ni-based tapes. This structure serves as a barrier to both inward diffusion of oxygen and outward diffusion of metal cations. Using PLD to grow YBCO, we demonstrate ideal electrical coupling to the metal substrate. Critical current (I{sub c}) values for 1 {mu}m thick YBCO coatings exceed 100 A/cm-width at 77 K on a Ni-W RABiTS template.

  10. Three-Dimensional Highly Stretchable Conductors from Elastic Fiber Mat with Conductive Polymer Coating.

    Science.gov (United States)

    Duan, Shasha; Wang, Zhihui; Zhang, Ling; Liu, Jin; Li, Chunzhong

    2017-09-13

    The manufacture of stretchable conductors with well-reserved electrical performance under large-degree deformations via scalable processes remains of great importance. In this work, a highly stretchable 3D conductive framework consisting of a polyurethane fiber mat (PUF) and poly(3,4-ethylenedioxythiophene) (PEDOT) is reported through facile approaches, electrospinning, and in situ interfacial polymerization, which was then backfilled with poly(dimethylsiloxane) to obtain 3D conductors. The excellent stretchability of the 3D conductive network imparted the as-prepared electrode a superior mechanical durability. Moreover, the applied strains can be effectively accommodated by the arrangement and orientation of the fibers resulting in a relatively stable electrical performance with only a 20% increased resistance at 100% stretching. Meanwhile, the resistance of the conductor could remain constant during 2000 bending cycles and showed a slight increase during 100 cycles of 50% stretching. The potential in the applications of large-area stretchable electrodes was demonstrated by the construction of LED arrays with the PUF-based conductors as electrical connections.

  11. Modeling the self-assembly of clathrin coats

    NARCIS (Netherlands)

    Giani, Matteo

    2017-01-01

    The assembly of clathrin coats in the presence of adaptor proteins was studied through computer simulations using coarse-grained models and through statistical mechanics. Adopting a reductionist approach based on recent experimental results, we aimed at reproducing and studying the minimal

  12. Modeling study of mesh conductors and their electroluminescent devices

    Science.gov (United States)

    Hu, Bin; Li, Dapeng; Manandhar, Prakash; Fan, Qinguo; Kasilingam, Dayalan; Calvert, Paul

    2015-02-01

    Numerical models were established to correlate with the experimentally measured properties of mesh conductors previously developed through a combined process of dip coating carbon nanotubes and inkjet printing poly 3,4-ethylenedioxythiophene: poly styrene sulfonate. The electroluminescent (EL) devices assembled with such mesh conductors as front electrodes were modeled by commercially available finite element method software COMSOL Multiphysics. The modeling results are in agreement with those from the experiments and suggest that an optimized fiber arrangement is the key for further improving the performance of EL devices based on mesh conductors.

  13. Magnetization Losses of Roebel Cable Samples with 2G YBCO Coated Conductor Strands

    CERN Document Server

    Yang, Y.; Falorio, I.; Young, E.A.; Kario, A.; Goldacker, W.; Dhallé, M. M. J.; van Nugteren, J.; Kirby, G.; Bottura, L.; Ballarino, A.

    2016-01-01

    Roebel cable with 2G YBCO strands is one of the promising HTS solutions of fully transposed high current conductors for high field accelerator magnets. Following the considerable research effort on the manufacturing of Roebel cables in recent years, sample conductors are now available in useful lengths with reproducible performances to allow detailed characterizations beyond the standard critical current measurements. The ac loss and strands coupling are of significant interest for the field quality of the accelerator magnets. We report a set of systematic ac loss measurements on two different Roebel cable samples prepared for the EuCARD2 collaboration. The measurements were performed over a wide range of temperature between 5 K and 90 K and the results were analyzed in the context of strands architecture and coupling. The results show that the transposed bundles are partially decoupled and the strands in transposition sections behave as an isolated single tape if the strands are insulated.

  14. Study on CexLa1-xO2 Buffer Layer used in Coated Conductors by Chemical Solution Method

    DEFF Research Database (Denmark)

    Zhao, Yue; Suo, Hongli; Grivel, Jean-Claude

    2009-01-01

    Developing multi-functional single buffer layer is one of the most important challenges for simplification of coated conductors configuration. Ladoped CeO2 films were prepared by chemical solution method. And surface morphology and texture quality of the La-doped CeO2 films were investigated...

  15. Oxygen order control by post-annealing for optimizing critical temperature of YBaCuO coated conductors with silver protective layer

    Science.gov (United States)

    Jian, Hongbin; Zhong, Huaxiao; Liu, Xumin; Liu, Zhiyong; Bai, Chuanyi; Lu, Yuming; Guo, Yanqun; Boubeche, Mebrouka; Fang, Qiang; Zhang, Hang; Cai, Chuanbing

    2017-07-01

    Oxygenation is one of the most essential processes for practical applications of REBa2Cu3O7-δ (RE123, RE = Y, Gd etc. rare earths) superconductors. Second generation high-Tc superconducting coated conductors are based on biaxial textured RE123 thin films, on which, a cover layer of silver for protecting is normally applied. It results in a little more complicated oxygenation process compared to naked film without silver protective layer. In the present work, a series of absorbing oxygen post-annealing processes were carried out for YBa2Cu3O7-δ coated conductors. The oxygen diffusion procedure and the kinetics in the annealing process were investigated. Analysis and calculations show that the activation energy was 1.01 eV, consistent with previous reports. Moreover, experiments show that the ;over-doping; phenomena frequently occurs in coated conductors, and thus dropping the Tc to as low as 86-88 K. To improve the temperature margin for practical applications (temperature difference between the superconducting transition temperature Tc and application temperature), we investigated the potential of increase in Tc by preventing from the ;over-doped; happening, while keeping oxygen in order. Finally, by employing the new annealing process, we can produce long (several hundred meters) coated conductor with high Tc,onset (92 K), narrow transition width and stable performance.

  16. An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

    DEFF Research Database (Denmark)

    Ainslie, Mark D; Rodriguez Zermeno, Victor Manuel; Hong, Zhiyong

    2011-01-01

    and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC...

  17. Approaches in controllable generation of artificial pinning center in REBa2Cu3Oy-coated conductor for high-flux pinning

    Science.gov (United States)

    Yoshida, Y.; Miura, S.; Tsuchiya, Y.; Ichino, Y.; Awaji, S.; Matsumoto, K.; Ichinose, A.

    2017-10-01

    This paper reviews the progress of studies to determine optimum shapes of the artificial pinning center (APC) of REBa2Cu3Oy thin films and coated conductors towards superconducting magnets operating at temperatures of 77 K or less. Superconducting properties vary depending on the kind and quantity of BaMO3 materials. Therefore, we study changes in the shapes of nanorods that are due to the difference in the quality of additives and growth temperature. In addition, we aim to control the APC using an optimum shape that matches the operating temperature. In particular, we describe the shape control of nanorods in SmBCO thin films and coated conductors by employing lower temperature growth (LTG) technology using seed layers. From the cross-sectional transmission electron microscopy observations, we confirmed that using the LTG method, the BaHfO3 (BHO) nanorods, which were comparatively thin and short in length, formed a firework structure in the case of SmBCO films with coated conductors. The superconducting properties in the magnetic field of the SmBCO-coated conductor with the optimum amount of BHO showed that {F}{{p}}\\max = 1.6 TN m‑3 on a single crystalline substrate and 1.5 TN m‑3 on metallic substrate with a biaxially textured MgO layer fabricated by ion-beam assisted deposition method tape 4.2 K.

  18. High-performance FeSe0.5Te0.5 thin films fabricated on less-well-textured flexible coated conductor templates

    Science.gov (United States)

    Xu, Zhongtang; Yuan, Pusheng; Ma, Yanwei; Cai, Chuanbing

    2017-03-01

    We report on the transport properties of FeSe0.5Te0.5 (FST) thin films fabricated on less-well-textured flexible coated conductor templates with LaMnO3 (LMO) as buffer layers using pulsed laser deposition. The LMO buffer layers exhibit large in-plane misalignment of ˜7.72°, which is unfavorable for cuprate-coated conductors due to the high grain boundaries. The FST thin films show a superconducting transition temperature of 16.8 K, higher than that of bulk materials due to the compressive strain between LMO and FST. Atomic force microscopy observations reveal that island-like features appear at the surfaces of both LMO and FST, confirming the island growth mode. A self-field transport critical-current density of up to 0.43 MA cm-2 at 4.2 K has been observed in FST thin films, which is much higher than that in powder-in-tube processed FST tapes. The films are capable of carrying current densities of over 105 A cm-2 in the whole applied magnetic field up to 9 T, showing great potential for high-field applications. The results indicate that, for FST, highly textured metal tapes are not needed to produce coated conductors with high performance, which is of great advantage over cuprate-coated conductors.

  19. Electromagnetic Scattering Analysis of Coated Conductors With Edges Using the Method of Auxiliary Sources (MAS) in Conjunction With the Standard Impedance Boundary Condition (SIBC)

    DEFF Research Database (Denmark)

    Anastassiu, H.T.; D.I.Kaklamani, H.T.; Economou, D.P.

    2002-01-01

    . The SIBC modeling of coated conductors with edges has previously been investigated in the literature and thus, this work focuses on comparing MAS and the method of moments (MoM) for SIBC surfaces (MoM/SIBC). A detailed complexity analysis shows that the MAS/SIBC method is, under certain conditions, more...

  20. Collective helicity switching of a DNA-coat assembly

    Science.gov (United States)

    Kim, Yongju; Li, Huichang; He, Ying; Chen, Xi; Ma, Xiaoteng; Lee, Myongsoo

    2017-07-01

    Hierarchical assemblies of biomolecular subunits can carry out versatile tasks at the cellular level with remarkable spatial and temporal precision. As an example, the collective motion and mutual cooperation between complex protein machines mediate essential functions for life, such as replication, synthesis, degradation, repair and transport. Nucleic acid molecules are far less dynamic than proteins and need to bind to specific proteins to form hierarchical structures. The simplest example of these nucleic acid-based structures is provided by a rod-shaped tobacco mosaic virus, which consists of genetic material surrounded by coat proteins. Inspired by the complexity and hierarchical assembly of viruses, a great deal of effort has been devoted to design similarly constructed artificial viruses. However, such a wrapping approach makes nucleic acid dynamics insensitive to environmental changes. This limitation generally restricts, for example, the amplification of the conformational dynamics between the right-handed B form to the left-handed Z form of double-stranded deoxyribonucleic acid (DNA). Here we report a virus-like hierarchical assembly in which the native DNA and a synthetic coat undergo repeated collective helicity switching triggered by pH change under physiological conditions. We also show that this collective helicity inversion occurs during translocation of the DNA-coat assembly into intracellular compartments. Translating DNA conformational dynamics into a higher level of hierarchical dynamics may provide an approach to create DNA-based nanomachines.

  1. Strong pinning in very fast grown reactive co-evaporated GdBa2Cu3O7 coated conductors

    Directory of Open Access Journals (Sweden)

    J. L. MacManus-Driscoll

    2014-08-01

    Full Text Available We report on compositional tuning to create excellent field-performance of Jc in “self-doped,” GdBa2Cu3O7−y (GdBCO coated conductors grown by ultrafast reactive co-evaporation. In order to give excess liquid and Gd2O3, the overall compositions were all Ba-poor and Cu-rich compared to GdBCO. The precise composition was found to be critical to the current carrying performance. The most copper-rich composition had an optimum self-field Jc of 3.2 MA cm−2. A more Gd-rich composition had the best in-field performance because of the formation of low coherence, splayed Gd2O3 nanoparticles, giving Jc (77 K, 1 T of over 1 MA cm−2 and Jc (77 K, 5 T of over 0.1 MA cm−2.

  2. Grain boundary transport properties in YBa{sub 2}Cu{sub 3}O{sub x} coated conductors.

    Energy Technology Data Exchange (ETDEWEB)

    Berghuis, P.; Miller, D. J.; Kim, D. H.; Gray, K. E.; Feenstra, R.; Christen, D. K.

    2000-11-02

    Critical current data obtained as a function of magnetic field on an isolated grain boundary (GB) of a coated conductor and two other types of bicrystal GBs of YBa{sub 2}Cu{sub 3}O{sub x} show a peak in the critical current and an unusual hysteresis. These results provide support for a new mechanism for enhanced GB critical currents, arising from interactions of GB vortices with pinned Abrikosov vortices in the banks of a GB, as suggested by Gurevich and Cooley. A substantial fraction of this enhancement, which can exceed a factor of ten, also occurs upon surpassing the critical current of the grains after zero field cooling. A bulk GB and thin film GBs show qualitatively identical results.

  3. Tuning the dipole directed assembly of core-shell nickel coated gold nanorods

    NARCIS (Netherlands)

    Hellenthal, Chris; Ahmed, W.; Kooij, Ernst S.; van Silfhout, Arend; Poelsema, Bene; Zandvliet, Henricus J.W.

    2012-01-01

    We present the dipole-directed assembly of nickel-coated gold nanorods into nanorings and nanowires. We used two different coating methods to synthesise these core-shell superstructures. Surprisingly, the two coating methods lead to very different kinds of dipole directed assembly. We show that the

  4. Development of Strontium Titanate Thin films on Technical Substrates for Superconducting Coated Conductors

    DEFF Research Database (Denmark)

    Pallewatta, Pallewatta G A P; Yue, Zhao; Grivel, Jean-Claude

    2012-01-01

    SrTiO3 is a widely studied perovskite material due to its advantages as a template for high temperature superconducting tapes. Heteroepitaxial SrTiO3 thin films were deposited on Ni/W tapes using dip-coating in a precursor solution followed by drying and annealing under reducing conditions. Nearl...

  5. Study on the interactions between the coatings of electric conductor or dielectric media and piezoelectric substrate in the piezoelectric functional devices

    Science.gov (United States)

    Hou, Peng-Fei; Zhang, Yang; Chen, Bing-Jie

    2017-09-01

    Because that most of piezoelectric functional devices are combined with the coatings of electric conductor or dielectric media and the piezoelectric substrate, the study on the interactions between them is valuable for their advanced design. In this paper, a method for the electro-mechanical coupling fields in these piezoelectric functional devices is presented. Firstly, the two-dimensional Green's function for a normal line force or line charge is derived. Then, based on the obtained Green's function, the interaction mechanism between the coatings of electric conductor or dielectric media and the piezoelectric substrate is studied. Finally, the electro-mechanical coupling fields under arbitrary loads are obtained by superposition principle and Gauss integration. Numerical results show that this method has high computational precision, efficiency and stability. And it can be used to improve the reliability and working performance of the piezoelectric functional device effectively.

  6. Study on the interactions between the coatings of electric conductor or dielectric media and piezoelectric substrate in the piezoelectric functional devices

    Directory of Open Access Journals (Sweden)

    Peng-Fei Hou

    2017-09-01

    Full Text Available Because that most of piezoelectric functional devices are combined with the coatings of electric conductor or dielectric media and the piezoelectric substrate, the study on the interactions between them is valuable for their advanced design. In this paper, a method for the electro-mechanical coupling fields in these piezoelectric functional devices is presented. Firstly, the two-dimensional Green’s function for a normal line force or line charge is derived. Then, based on the obtained Green’s function, the interaction mechanism between the coatings of electric conductor or dielectric media and the piezoelectric substrate is studied. Finally, the electro-mechanical coupling fields under arbitrary loads are obtained by superposition principle and Gauss integration. Numerical results show that this method has high computational precision, efficiency and stability. And it can be used to improve the reliability and working performance of the piezoelectric functional device effectively.

  7. Nanostructural Characterization of Low Resistance Joints Using Ag Pastes for GdBa2Cu3O7-x Coated Conductors

    Science.gov (United States)

    Kato, Tomohiro; Machi, Takato; Yokoe, Daisaku; Yoshida, Ryuji; Kato, Takeharu; Izumi, Teruo; Hirayama, Tsukasa; Shiohara, Yuh

    2017-07-01

    GdBa2Cu3O7-x coated conductors were splice jointed by a face-to-face manner using a paste containing nano-sized Ag particles under a pressure of about 50 MPa at 150 °C for 1 hr. The low electrical resistance of 6 nΩ at the joint was attained. Nanostructural characterizations of the starting Ag paste and the jointed region of the coated conductors were carried out using scanning electron microscopy and transmission electron microscopy. The size of the Ag particles in the starting pastes were confirmed to be a few tens of nanometers in diameter. The size of Ag particles became larger during the jointing process. Both the surfaces of the stabilizing Ag layers were partially bonded by the Ag particles. No oxides or other elements were detected in the region of the bonding parts.

  8. The thermal voltage fluctuations in the planar core-coat conductor of a neuron-semiconductor interface.

    Science.gov (United States)

    Zeitler, Ralf; Fromherz, Peter

    2013-05-21

    The extracellular electrical interfacing of nerve cells with metals or semiconductors is governed by the resistance of the cell-solid junction. With snail neurons on a CMOS chip, we have probed the thermal voltage fluctuations in the junction at a spatial resolution of 7.4 μm in a spectral range from 10 Hz to 1 MHz using an array of sensor transistors. The power spectral density (PSD) could be interpreted in terms of a Johnson-Nyquist noise if the distributed nature of the cell-solid junction and the size of the sensors were taken into account. The PSD over the whole spectral range as well as its spatial profile were matched by the thermal noise of a circular core-coat conductor with a homogeneous sheet resistance in the range of 100 MΩ. The quantitative interpretation of the thermal noise in a cell-solid junction provides a basis for applications of this noninvasive method in the characterization of biosensoric and neuroprosthetic devices.

  9. Measurement and Analysis of Normal Zone Propagation in a ReBCO Coated Conductor at Temperatures Below 50K

    CERN Document Server

    van Nugteren, J; Wessel, S; Krooshoop, E; Nijhuis, A; ten Kate, H

    2015-01-01

    Measurements of the quasi-adiabatic normal zone propagation velocity and quench energies of a Superpower SCS4050 copper stabilised ReBCO superconducting tape are presented over a temperature range of 23 − 47 K; in parallel applied magnetic fields of 6, 10 and 14 T; and over a current range from 50% to 100% of Ic. The data are compared to results of analytic predictions and to one-dimensional numerical simulations. The availability of long lengths of ReBCO coated conductor makes the material interesting for many HTS applications operating well below the boiling point of liquid nitrogen, such as magnets and motors. One of the main issues in the design of such devices is quench detection and protection. At higher temperatures, the quench velocities in these materials are known to be about two orders of magnitude lower compared to low temperature superconductors, resulting in significantly smaller normal zones and the risk of higher peak temperatures. To investigate whether the same also holds for lower tempera...

  10. Protective Coatings for Space System Components Fabricated Using Ionic Self Assembled Monolayer Processes

    National Research Council Canada - National Science Library

    Miler, Mike

    1997-01-01

    Self-assembled multilayer thin film fabrication methods offer unique opportunities to incorporate multiple functionalities into coatings for space system materials and structures as well as consumer products...

  11. Textured Ni-9.0 at.% W substrate tapes for YBCO-coated conductors

    Science.gov (United States)

    Eickemeyer, J.; Hühne, R.; Güth, A.; Rodig, C.; Gaitzsch, U.; Freudenberger, J.; Schultz, L.; Holzapfel, B.

    2010-08-01

    Cube textured tapes were prepared by cold rolling and annealing (RABiTS method) from nickel alloyed with 9.0 at.% tungsten in order to get a flexible nonmagnetic substrate for superconductors of the Y Ba2Cu3O7 - δ (YBCO) type. A fraction of up to 96% of cube orientation was measured for the Ni-9.0 at.% W alloy tape. First coating experiments by pulsed laser deposition revealed an epitaxial growth of the buffer and the YBCO layers on the developed substrate. Critical current densities Jc of up to 1.10 MA cm - 2 were measured at 77 K in self-field.

  12. Modeling pressure-driven assembly of polymer coated nanoparticles

    Science.gov (United States)

    Lane, J. Matthew D.; Salerno, K. Michael; Grest, Gary S.; Fan, Hongyou

    2017-06-01

    High-pressure experiments have successfully produced a variety of gold nanostructures by compressing polymer coated spherical nanoparticles. We apply atomistic simulation to understand the role of the soft polymer response in determining the pressure-driven assembly of gold nanostructures. Quasi-isentropic experiments have shown that 1D, 2D and 3D nanostructures can be formed and recovered from dynamic compression of fcc superlattices of alkanethiol-coated gold nanocrystals on Sandia's Veloce pulsed power accelerator. Molecular modeling has shown that the dimensionality of the final structures depends on the orientation of the superlattice and the uniaxial loading. We describe the role of coating ligand length and grafting density, on ligand migration and deformation processes during pressure-driven coalescence of the cores into permanent nanowires, nanosheets and 3D structures. The role of uniaxial vs isotropic pressure and the effects of compression along various superlattice orientations will be discussed. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  13. Long tape processing for coated conductors by multiple-stage CVD method

    Energy Technology Data Exchange (ETDEWEB)

    Kashima, N.; Niwa, T.; Nagaya, S.; Onabe, K.; Saito, T.; Muroga, T.; Miyata, S.; Watanabe, T.; Yamada, Y

    2004-10-01

    The multiple-stage CVD method is the promising technology, which can be realized for rapid and long formation of YBCO tape. In earlier researches, we have fabricated the six-stage CVD system, and successfully developed 100 m long YBCO tape at the deposition rate of 10 m/h. However, over 500 m long wires are required for the practical applications. In order to achieve this, we have studied the multi-coating of YBCO layer at further high-speed deposition. Five layers of YBCO tape were fabricated on roll milled non-textured Ag substrate directly. Each layer was deposited by the six-stage CVD system at deposition rate of 25 m/h. After each deposition, temperature of YBCO tape went down to room temperature. The distribution of J{sub c} was within 25% and its value is the same as single coating one. No significant degradation of J{sub c} was observed. From these results, it was indicated that the multiple-stage CVD system, which equips more reactors serially, is effective way for making longer YBCO tapes.

  14. Insulation effect on thermal stability of Coated Conductors wires in liquid nitrogen

    Science.gov (United States)

    Rubeli, Thomas; Dutoit, Bertrand; Martynova, Irina; Makarevich, Artem; Molodyk, Alexander; Samoilenkov, Sergey

    2017-02-01

    Superconducting wires are not perfectly homogeneous in term of critical current as well as stabilization. In resistive fault current limiter applications this could lead to hot spots if the fault current is only slightly above the nominal current of the device. Increasing stabilization by using thicker silver coating for example may prevent this problem but this method implies longer wire length to maintain the same impedance during a fault. Very efficient cooling in another way to prevent hot spots, this can be achieved in nucleate boiling regime. Optimal insulation can be used to prevent film boiling regime, staying in nucleate boiling regime in a much broader temperature range. In this work a novel technique is used to monitor in real time the temperature of the wire during the quench. Using this method several increasing insulation thicknesses are tested, measuring for each the heat exchange rate to the nitrogen bath. Exchange rate measurements are made in quasistatic regime and during the re-cooling of the wire. SuperOx wires provided with different insulation thicknesses exhibit an excellent stability, far above a bare wire. On the other side, for very thick insulations the stability gain is lost. Re-cooling speeds dependency on insulation thicknesses is measured too.

  15. Enhancement of delamination strength in Cu-stabilized coated conductor tapes through additional treatments under transverse tension at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyung Seop; Bautista, Zhierwinjay [Andong National University, Andong (Korea, Republic of); Moon, Seung Hyun; Lee, Jae Hun; Mean, Byoung Jean [SuNAM Co Ltd., Anseong (Korea, Republic of)

    2017-06-15

    In superconducting coil applications particularly in wet wound coils, coated conductor (CC) tapes are subjected to different type of stresses that could affect its electromechanical transport property. These include hoop stress acting along the length of the CC tape and the Lorentz force acting perpendicular to the CC tape’s surface. Since the latter is commonly associated with the delamination problem of multi-layered REBCO CC tapes, more understanding and attention on the delamination phenomena induced in the case of coil applications are needed. Difference on the coefficient of thermal expansion (CTE) of each constituent layer of the CC tape, the bobbin, and the impregnating materials is the main causes of delamination in CC tapes when subjected to thermal and mechanical cycling. In the design of degradation-free superconducting coils, therefore, characterization of the delamination behaviors including mechanism and strength in the multi-layered REBCO CC tapes becomes a critical issue. Various trials to increase the delamination strength by improving interface characteristics at interlayers have been performed. In this study, in order to investigate the influences of laser cleaning and Ag annealing treated at the substrate side surface, transverse tensile tests were conducted under different sample configurations using 4.5mm x 8 mm upper anvil. The mechanical delamination strength of differently processed CC samples was examined at room temperature (RT). As a result, the Sample 1 with the additional laser cleaning and Ag annealing processes and the Sample 2 with additional Ag annealing process only showed higher mechanical delamination strength as compared to the Sample 3 without such additional treatments. Sample 3 showed quite different behavior when the loading direction is to the substrate side where the delamination strength much lower as compared to other cases.

  16. Over-current characteristics of superconducting model cable using YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Ishiyama, A. [Department of Electrical Engineering and Bioscience, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan)], E-mail: atsushi@waseda.jp; Wang, X.; Ueda, H. [Department of Electrical Engineering and Bioscience, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Yagi, M.; Mukoyama, S. [Furukawa Electric Co., Ltd., Ecology and Energy Laboratory, Ichihara 290-8555 (Japan); Kashima, N.; Nagaya, S. [Chubu Electric Power Co., Inc., Nagoya (Japan); Shiohara, Y. [International Superconductivity Technology Center, Superconductivity Research Laboratory, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2008-09-15

    For the application to power transmission cables, a number of YBCO tapes would be assembled and wound in spiral on a Cu-former. YBCO tapes and the Cu-former are connected in parallel and they might be subjected to short-circuit fault currents 10-30 times the operating current. In this study, we constructed a 1 m long YBCO model cable. Over-current with a peak of 31.5 kArms and a duration of 2.0 s, which was established by JEC (Japanese Electrotechnical Committee), was applied to this cable in a liquid nitrogen bath. The redistribution of the transport current between YBCO tapes and the Cu-former were examined by using Hall sensors. The numerical simulations were carried out using a newly developed computer program based on the 3D finite element method (FEM) in order to clarify the over-current characteristics in the cable. From the comparison of the experimental and simulation results, the validity of the developed computer program was confirmed. Therefore, we performed the simulations of a 10 m long model cable when carrying a fault current of 31.5 kArms applied for a durations of 2.0 s, and also estimated the influence of the cross-section area of the Cu-former and the Cu shield layer on the thermal behavior of the model cable by using the developed computer program.

  17. Overcurrent characteristics of 1 m long superconducting model cable using YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, H; Wang, X; Ishiyama, A [Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Mukoyama, S; Yagi, M [Furukawa Electric Co., Ltd., Ecology and Energy Laboratory, Ichihara 290-8555 (Japan); Kashima, N; Nagaya, S [Chubu Electric Power Co., Inc., Nagoya 459-8522 (Japan); Shiohara, Y [ISTEC-SRL, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan)], E-mail: ueda@super.elec.waseda.ac.jp

    2008-02-01

    In applications to power transmission cables, a number of YBCO tapes would be assembled and wound spirally on a Cu former. The YBCO tapes and the Cu former would be connected in parallel and could be subjected to short-circuit fault currents 10 to 30 times the operating current. The fault currents would drive the YBCO tapes into the normal state and thus generate Joule heating for the duration of the fault. Therefore, in order to examine the stability and feasibility of YBCO power transmission cables, it is important to demonstrate the redistribution of the transport current and the electromagnetic coupling between the YBCO tapes and the Cu former during a short-circuit fault current. We constructed a 1 m long superconducting model cable and subjected it to an overcurrent with a peak of 31.5 kA{sub rms} for a duration of 2.0 s, as established by JEC (Japanese Electrotechnical Committee), in a liquid nitrogen bath. We examined the redistribution of the transport current between the YBCO sample tapes and the Cu former by using Hall probes. In addition, we developed a novel computer code based on the finite element method and an equivalent circuit in order to clarify the characteristics of the redistribution of the transport current and the thermal behaviour within the cable. Finally, we designed a 10 m long cable that would reach the degradation temperature of the YBCO tape due to the fault currents.

  18. Stochastic nature of clathrin-coated pit assembly

    Science.gov (United States)

    Banerjee, Anand; Berezhkovskii, Alexander; Nossal, Ralph

    2013-03-01

    Clathrin-mediated endocytosis is a complex process through which eukaryotic cells internalize various macromolecules (cargo). The process occurs via the formation of invaginations on the cell membrane, called clathrin-coated pits (CCPs). The dynamics of CCP formation shows remarkable variability. After initiation, a fraction of CCPs, called ``productive pits'', bind to cargo and then grow and mature into clathrin-coated vesicles (CCVs). In contrast, a large fraction of CCPs, called ``abortive pits'', fail to bind to cargo, grow only up to intermediate sizes and then disassemble. There is notable heterogeneity in the lifetimes of both productive and abortive pits. We propose a stochastic model of CCP dynamics to explain these experimental observations. Our model includes a kinetic scheme for CCP assembly and a related functional form for the dependence of free energy of a CCP on its size. Using this model, we calculate the lifetime distribution of abortive pits (via Monte Carlo simulation) and show that the distribution fits experimental data very well. By fitting the data we determine the free energy of CCP formation and show that CCPs without cargo are energetically unstable. We also suggest a mechanism by which cargo binding stabilizes CCPs and facilitates their growth.

  19. Fibrillar assembly and stability of collagen coating on titanium for improved osteoblast responses.

    Science.gov (United States)

    Kim, Hae-Won; Li, Long-Hao; Lee, Eun-Jung; Lee, Su-Hee; Kim, Hyoun-Ee

    2005-12-01

    Collagen, as a major constituent of human connective tissues, has been regarded as one of the most important biomaterials. As a coating moiety on Ti hard-tissue implants, the collagen has recently attracted a great deal of attention. This article reports the effects of fibrillar assembly and crosslinking of collagen on its chemical stability and the subsequent osteoblastic responses. The fibrillar self-assembly of collagen was carried out by incubating acid-dissolved collagen in an ionic-buffered medium at 37 degrees C. The degree of assembly was varied with the incubation time and monitored by the turbidity change. The differently assembled collagen was coated on the Ti and crosslinked with a carbodiimide derivative. The partially assembled collagen contained fibrils with varying diameters as well as nonfibrillar aggregates. On the other hand, the fully assembled collagen showed the complete formation of fibrils with uniform diameters of approximately 100-200 nm with periodic stain patterns within the fibrils, which are typical of native collagen fibers. Through this fibrillar assembly, the collagen coating had significantly improved chemical stability in both the saline and collagenase media. The subsequent crosslinking step also improved the stability of the collagen coating, particularly in the unassembled collagen. The fibrillar assembly and the crosslinking of collagen significantly influenced the osteoblastic cell responses. Without the assembly, the collagen layer on Ti adversely affected the cell attachment and proliferation. However, those cellular responses were improved significantly when the collagen was assembled to fibrils and the assembly degree was increased. After crosslinking the collagen coating, these cellular responses were significantly enhanced in the case of the unassembled collagen but were not altered much in the assembled collagen. Based on these observations, it is suggested that the fibrillar assembly and the crosslinking of collagen

  20. Architecture for coated conductors

    Science.gov (United States)

    Foltyn, Stephen R.; Arendt, Paul N.; Wang, Haiyan; Stan, Liliana

    2010-06-01

    Articles are provided including a base substrate having a layer of an oriented cubic oxide material with a rock-salt-like structure layer thereon, and, a layer of epitaxial titanium nitride upon the layer of an oriented cubic oxide material having a rock-salt-like structure. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of epitaxial titanium nitride or upon a intermediate buffer layer upon the layer of epitaxial titanium nitride.

  1. Introduction of pinning centers into Sm1+xBa2Cu3+YO7-d coated conductor by reactive co-evaporation method

    Science.gov (United States)

    Kim, Gwan-Tae; Kim, Ho-Sup; Ha, Dong-Woo; Chung, Kook-Chae; Shinde, Kiran

    2018-02-01

    Sm1+xBa2Cu3+yO7-d (SmBCO)-coated conductors containing pinning centers were prepared by a reactive co-evaporation method using the EDDC (Evaporation using Drum in Dual Chamber) deposition system. Superconducting materials based on Sm, Ba, and Cu were evaporated in the evaporation chamber and deposited onto the drum-mounted substrate, while the deposited element reacted with oxygen and resulting in the SmBCO superconducting phase inside the reaction chamber. Tape-type samples (length = 30 cm, width = 4 mm, thickness = 0.1 mm) with the structure of Ag/SmBCO/LMO/MgO/Y2O3/Al2O3/Hastelloy were prepared, where the SmBCO film was spread along the tape length. The critical current was measured using the non-contact Hall-probe method, and the field dependences of the critical current under a high magnetic field were measured. The superconducting properties of the samples under a magnetic field were highly influenced by the composition of the SmBCO film. Furthermore, elemental mapping of the high-Jc SmBCO-coated conductor was measured by transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM-EDX). Finally, we confirmed the Sm-related secondary phases take the role of pinning centers.

  2. The Effect of Sintering Oxygen Partial Pressure on a SmBiO3 Buffer Layer for Coated Conductors via Chemical Solution Deposition

    Directory of Open Access Journals (Sweden)

    Xiaolei Zhu

    2016-10-01

    Full Text Available The application of high-temperature YBa2Cu3O7−δ (YBCO superconducting material is a considerable prospect for the growing energy shortages. Here, SmBiO3 (SBO films were deposited on (100-orientated yttrium-stabilized zirconia (YSZ simple crystal substrates via the chemical solution deposition (CSD approach for coated conductors, and the effects of sintering oxygen partial pressure on SBO films were studied. The crystalline structures and surface morphologies of SBO films were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and atomic force microscope (AFM. The optimized growth temperature, the intensity ratios of the SBO (200 peak to the SBO (111 peak, and the crystallinities of SBO films increased with the sintering oxygen partial pressure. The SEM and AFM images displayed a smooth and well-distributed surface in the argon atmosphere. The subsequent YBCO films with superconducting transition temperatures (Tc = 89.5 K, 90.2 K, and 86.2 K and critical current densities (Jc = 0.88 MA/cm2, 1.69 MA/cm2, and 0.09 MA/cm2; 77 K, self-field were deposited to further check the qualities of the SBO layer. These results indicated that sintering oxygen partial pressure had an effect on the epitaxial growth of the SBO buffer layer and YBCO superconducting properties. The experimental results may be a usable reference for the epitaxial growth of YBCO-coated conductors and other oxides.

  3. An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

    Science.gov (United States)

    Ainslie, Mark D.; Rodriguez-Zermeno, Victor M.; Hong, Zhiyong; Yuan, Weijia; Flack, Timothy J.; Coombs, Timothy A.

    2011-04-01

    AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss in superconducting coils made from YBCO coated conductors for use in an all-superconducting electric machine. This paper presents an improved 2D finite element model for the cross-section of such coils, based on the H formulation. The model is used to calculate the transport AC loss of a racetrack-shaped coil using constant and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC Superconductivity Group's all-superconducting permanent magnet synchronous motor design. To validate the modeling results, the transport AC loss of a stator coil is measured using an electrical method based on inductive compensation by means of a variable mutual inductance. Finally, the implications of the findings on the performance of the motor are discussed.

  4. Effect of solder flux residue on the performance of silicone conformal coatings on printed circuit board assemblies

    DEFF Research Database (Denmark)

    Rathinavelu, Umadevi; Jellesen, Morten Stendahl; Ambat, Rajan

    2013-01-01

    Conformal coatings are applied on printed circuit board assemblies (PCBAs) in order to protect the assembly from environmental influence and silicone-based coating is commonly used. A systematic study on the performance of silicone conformal coating in connection with process-related contaminants...

  5. Self-assembled hemocompatible coating on poly (vinyl chloride) surface

    Science.gov (United States)

    Zha, Zhengbao; Ma, Yan; Yue, Xiuli; Liu, Meng; Dai, Zhifei

    2009-11-01

    A stable hemocompatible coating was fabricated by consecutive alternating adsorption of iron (III) and two kinds of polysaccharides, heparin (Hep) and dextran sulfate (DS), onto poly (vinyl chloride) (PVC) surfaces via electrostatic interaction. The fluctuation of contact angles with the alternative deposition of iron (III) and polysaccharides verified the progressive buildup of the mulitilayer coating onto the PVC surface. Atomic force microscopy (AFM) analysis revealed that the PVC surfaces were completely masked by iron-polysaccharides multilayer coatings. The activated partial thromboplastin time (APTT) assay showed that both Hep/Fe 3+/Hep and DS/Fe 3+/Hep coated PVC were less thrombogenic than the uncoated one. Chromogenic assay for heparin activity proved definitively that the inhibition of locally produced thrombin was ascribed to the thromboresistance of the surface-bound heparin. Compared with the unmodified PVC surfaces, iron-polysaccharide multilayer coating presented a drastically reduced adhesion in vitro of platelets, polymorphonuclear neutrophil leukocytes (PMN) and peripheral blood mononuclear cells (PBMC). Interestingly, the DS/Fe 3+/Hep coating was found to exhibit higher hydrophilicity and stability, hence lower non-specific protein adsorption in comparison with Hep/Fe 3+/Hep coating due to the incorporation of dextran sulfate into the multilayer coating.

  6. Self-assembled hemocompatible coating on poly (vinyl chloride) surface

    Energy Technology Data Exchange (ETDEWEB)

    Zha Zhengbao; Ma Yan; Yue Xiuli; Liu Meng [Nanobiotechnology Division, State Key Laboratory of Urban Water Resources and Environment, School of Sciences, Harbin Institute of Technology, Harbin 150001 (China); Dai Zhifei, E-mail: zhifei.dai@hit.edu.cn [Nanobiotechnology Division, State Key Laboratory of Urban Water Resources and Environment, School of Sciences, Harbin Institute of Technology, Harbin 150001 (China)

    2009-11-15

    A stable hemocompatible coating was fabricated by consecutive alternating adsorption of iron (III) and two kinds of polysaccharides, heparin (Hep) and dextran sulfate (DS), onto poly (vinyl chloride) (PVC) surfaces via electrostatic interaction. The fluctuation of contact angles with the alternative deposition of iron (III) and polysaccharides verified the progressive buildup of the mulitilayer coating onto the PVC surface. Atomic force microscopy (AFM) analysis revealed that the PVC surfaces were completely masked by iron-polysaccharides multilayer coatings. The activated partial thromboplastin time (APTT) assay showed that both Hep/Fe{sup 3+}/Hep and DS/Fe{sup 3+}/Hep coated PVC were less thrombogenic than the uncoated one. Chromogenic assay for heparin activity proved definitively that the inhibition of locally produced thrombin was ascribed to the thromboresistance of the surface-bound heparin. Compared with the unmodified PVC surfaces, iron-polysaccharide multilayer coating presented a drastically reduced adhesion in vitro of platelets, polymorphonuclear neutrophil leukocytes (PMN) and peripheral blood mononuclear cells (PBMC). Interestingly, the DS/Fe{sup 3+}/Hep coating was found to exhibit higher hydrophilicity and stability, hence lower non-specific protein adsorption in comparison with Hep/Fe{sup 3+}/Hep coating due to the incorporation of dextran sulfate into the multilayer coating.

  7. Deposition of Coatings from Live Yeast Cells and Large Particles by “Convective-Sedimentation” Assembly

    Science.gov (United States)

    Jerrim, Lindsey B.; Velev, Orlin D.

    2009-01-01

    Convective assembly at high volume fraction was used for the rapid deposition of uniform, close-packed coatings of Saccharomyces cerevisiae yeast cells onto glass slides. A computational model was developed to calculate the thickness profiles of such coatings for different set of conditions. Both the experiments and the numerical simulations demonstrated that the deposition process is strongly affected by the presence of sedimentation. The deposition device was inclined to increase the uniformity of the coatings by causing the cells to sediment toward the three-phase contact line. In accordance with the simulation, the experiments showed that both increasing the angle of the device and decreasing the angle between the slides increased the uniformity of the deposited coatings. Finally, the “convective-sedimentation” assembly method was used to deposit mixed layers of live cells and large latex particles as an example of immobilized biologically active composite coatings. PMID:19366200

  8. Effect of the axial stress and the magnetic field on the critical current and the electric resistance of the joints between HTS coated conductors

    Science.gov (United States)

    Konstantopoulou, K.; Sarazin, M.; Granados, X.; Y Pastor, J.; Obradors, X.

    2015-06-01

    High temperature superconducting (HTS) wires require a detailed characterization of the possible degradation of their properties by handling at room temperature as well as during their service life, establishing the limits for associated functional devices and systems. In this paper, we study the mechanical behavior of spliced joints between commercial HTS coated conductors based on YBCO at room (300 K) and service temperatures (77 K). Single lap shear tests were performed and the evolution of the critical current and electric resistivity of the joints were measured. The complete strain field for the tape and joints was also obtained by digital image correlation. In addition, tensile tests under an external magnetic field were performed, and the effect of the applied field on the critical current and electric resistivity of the joints were studied. Finally, finite element simulations were employed to reproduce the distribution of the stress field developed in the spliced joint samples during axial loading.

  9. Phase Evolution of YBa2Cu3O7-x films by all-chemical solution deposition route for coated conductors

    DEFF Research Database (Denmark)

    Yue, Zhao; Tang, Xiao; Wu, Wei

    2014-01-01

    In order to understand the all-chemical-solution-deposition (CSD) processes for manufacturing coated conductors, we investigated the phase evolution of YBa2Cu3O7 (YBCO) films deposited by a low-fluorine metal-organic solution deposition (LF-MOD) method on CSD derived Ce0.9La0.1O2/Gd2Zr2O7/Ni......-MOD cases. Moreover, we found that the formation of impurities (mainly BaCeO3, NiWO4 and NiO) is strongly related to the annealing temperature, i.e., the diffusion controlled reactions become intensive from 760 oC, which might be connected with the poor structural and superconducting properties of the films...

  10. LTS and HTS high current conductor development for DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzone, Pierluigi, E-mail: pierluigi.bruzzone@psi.ch [EPFL-CRPP, Fusion Technology, CH-5232 Villigen-PSI (Switzerland); Sedlak, Kamil; Uglietti, Davide; Bykovsky, Nikolay [EPFL-CRPP, Fusion Technology, CH-5232 Villigen-PSI (Switzerland); Muzzi, Luigi; De Marzi, Gainluca; Celentano, Giuseppe; Della Corte, Antonio; Turtù, Simonetta [ENEA, Superconductivity Division, I-00044 Frascati (Italy); Seri, Massimo [TRATOS Cavi Spa, I-52036 Pieve Santo Stefano (Italy)

    2015-10-15

    Highlights: • Design and R&D for DEMO TF conductors. • Wind&react vs. react&wind options for Nb{sub 3}Sn high grade TF conductors. • Progress in the manufacture of short length Nb{sub 3}Sn proptotypes. • Design and prototype manufacture for high current HTS cabled conductors. - Abstract: The large size of the magnets for DEMO calls for very large operating current in the forced flow conductor. A plain extrapolation from the superconductors in use for ITER is not adequate to fulfill the technical and cost requirements. The proposed DEMO TF magnets is a graded winding using both Nb{sub 3}Sn and NbTi conductors, with operating current of 82 kA @ 13.6 T peak field. Two Nb{sub 3}Sn prototypes are being built in 2014 reflecting the two approaches suggested by CRPP (react&wind method) and ENEA (wind&react method). The Nb{sub 3}Sn strand (overall 200 kg) has been procured at technical specification similar to ITER. Both the Nb{sub 3}Sn strand and the high RRR, Cr plated copper wire (400 kg) have been delivered. The cabling trials are carried out at TRATOS Cavi using equipment relevant for long length production. The completion of the manufacture of the two 20 m long prototypes is expected in the end of 2014 and their test is planned in 2015 at CRPP. In the scope of a long term technology development, high current HTS conductors are built at CRPP and ENEA. A DEMO-class prototype conductor is developed and assembled at CRPP: it is a flat cable composed of 20 twisted stacks of coated conductor tape soldered into copper shells. The 10 kA conductor developed at ENEA consists of stacks of coated conductor tape inserted into a slotted and twisted Al core, with a central cooling channel. Samples have been manufactured in industrial environment and the scalability of the process to long production lengths has been proven.

  11. ALTERNATING CURRENT LOSSES IN AG-SHEATHED BSCCO (2212 AND 2223) TAPES AND WIRES AND YBCO (123) COATED CONDUCTORS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. John S. Hurley

    2000-01-01

    In this study, we focus on the examination of ac losses in conductors utilizing Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O [BSCCO (2223)] high TC superconductors (HTS). In addition, we seek to assist other facilities such as the University of Wisconsin-Madison Applied Superconductivity Center (UW-ASC), Brookhaven National Laboratory, and other DoE facilities investigating the use of HTS in electric power applications (e.g., generators, motors, and transformers). To accomplish this we will develop an ac losses capability at Clark Atlanta University to complement the established ac losses efforts at Brookhaven National Laboratory (BSCCO) on BSCCO/Ag and various material characterization efforts taking place at the UW-ASC. Our goal is through this effort to gain a greater understanding of the effects on ac losses due to parameters such as ac/dc current, J{sub c}, tape geometry, voltage tap placement, field orientation, material anisotropy, surface irregularities, percolations and filament coupling effects. As a result, we expect to better understand how to minimize ac losses in applications requiring real or practical conductors. HTS conductors based on BSCCO-2223 are now being routinely produced in industrial lengths of high quality. Vendors such as Southwire and ASC are producing multi-filamentary tapes in lengths of 6 km or more carrying critical current densities of up to 3 kA/cm**2 at 77 K. While this is approaching the level of performance where some large-scale applications are considered to be economically viable, a number of problems remain to be solved. The remaining issues include: rapid reduction in JC in magnetic fields; and power dissipation due to varying magnetic fields or currents (ac losses).

  12. Self-assembled polyelectrolyte complexes films as efficient compression coating layers for controlled-releasing tablets.

    Science.gov (United States)

    Li, Wenyan; Huo, Mengmeng; Sen Chaudhuri, Arka; Yang, Chen; Cao, Dazhong; Wu, Zhenghong; Qi, Xiaole

    2017-05-01

    Currently, polysaccharide-based hydrogels are widely studied macromolecular networks to modify drug dissolution from controlled-releasing matrix tablets. Among them, polyelectrolyte complexes (PEC) films consisted of chitosan (CS) and sodium alginate (SA) could be obtained via spontaneously assembling under physiological gastrointestinal environment. Here, we utilized these self-assembled PEC films as an efficient coating materials to develop controlled-released matrix tablets through compression coating process, with paracetamol (APAP) as model drug. The constitutive and morphology characteristic studies on these PEC films illustrated that the mixture of CS and SA with the weight ratio of 1:1 would be an promising outer layer for compression-coating tablets. In addition, the in vitro drug releasing behavior experiments demonstrated that the optimized compression coating tablets displayed satisfied zero-order drug releasing profits. Furthermore, the in vivo pharmacokinetic studies of these APAP loaded compression-coated tablets in New Zealand rabbits gave that the T max (12.32 ± 1.05 h) was significantly prolonged (p tablets (Jinfuning ® ) after oral administration. These studies suggest that the compression-coated tablets with self-assembled PEC film as coating outer layer may be a promising strategy for peroral controlled release delivery system of water soluble drugs.

  13. Water-Based Assembly of Polymer-Metal Organic Framework (MOF) Functional Coatings

    Energy Technology Data Exchange (ETDEWEB)

    De, Souvik [Artie McFerrin Department of Chemical Engineering, Texas A& M University, 77843-3122 TAMU College Station TX 77843-3122 USA; Nandasiri, Manjula I. [Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory, Richland WA 99352 USA; Schaef, Herbert T. [Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; McGrail, Benard Peter [Energy & Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Nune, Satish K. [Energy & Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Lutkenhaus, Jodie L. [Artie McFerrin Department of Chemical Engineering, Texas A& M University, 77843-3122 TAMU College Station TX 77843-3122 USA; Department of Materials Science & Engineering, Texas A& M University, 3122 TAMU College Station TX 77843-3122 USA

    2016-12-27

    Metal organic frameworks (MOFs) have gained tremendous attention for their porosity, size selectivity, and structural diversity. There is a need for MOF-based coatings, particularly in applications such as separations, electronics and energy; yet forming thin, functional, conformal coatings is prohibitive because MOFs exist as a powder. Layer-by- layer assembly, a versatile thin film coating approach, offers a unique solution to this problem, but this approach requires MOFs that are water-dispersible and bear a surface charge. Here, we address these issues by examining water-based dispersions of MIL-101(Cr) that facilitate the formation of robust polymer-MOF hybrid coatings. Specifically, the substrate to be coated is alternately exposed to an aqueous solution of poly(styrene sulfonate) and dispersion MIL-101(Cr), yielding linear film growth and coatings with a MOF content as high as 77 wt%.This approach is surface-agnostic, in which the coating is successfully applied to silicon, glass, flexible plastic, and even cotton fabric, conformally coating individual fibers. In contrast, prior attempts at forming MOF-coatings were severely limited to a handful of surfaces, required harsh chemical treatment, and were not conformal. The approach presented here unambiguously confirms that MOFs can be conformally coated onto complex and unusual surfaces, opening the door for a wide variety of applications.

  14. Barrier efficiency of sponge-like La{sub 2}Zr{sub 2}O{sub 7} buffer layers for YBCO-coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Leopoldo; Tan, Haiyan; Biermans, Ellen; Verbeeck, Jo; Bals, Sara; Tendeloo, Gustaaf Van [EMAT, University of Antwerp, Groenenborgerlaan 171, BE-2020 Antwerp (Belgium); Batenburg, Kees J, E-mail: leopoldo.molina-luna@ua.ac.be [Vision Lab, University of Antwerp, Universiteitsplein 1, BE-2020 Wilrijk (Belgium)

    2011-06-15

    Solution derived La{sub 2}Zr{sub 2}O{sub 7} films have drawn much attention for potential applications as thermal barriers or low-cost buffer layers for coated conductor technology. Annealing and coating parameters strongly affect the microstructure of La{sub 2}Zr{sub 2}O{sub 7}, but different film processing methods can yield similar microstructural features such as nanovoids and nanometer-sized La{sub 2}Zr{sub 2}O{sub 7} grains. Nanoporosity is a typical feature found in such films and the implications for the functionality of the films are investigated by a combination of scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS) and quantitative electron tomography. Chemical solution based La{sub 2}Zr{sub 2}O{sub 7} films deposited on flexible Ni-5 at.%W substrates with a {l_brace}100{r_brace}(001) biaxial texture were prepared for an in-depth characterization. A sponge-like structure composed of nanometer-sized voids is revealed by high-angle annular dark-field scanning transmission electron microscopy in combination with electron tomography. A three-dimensional quantification of nanovoids in the La{sub 2}Zr{sub 2}O{sub 7} film is obtained on a local scale. Mostly non-interconnected highly faceted nanovoids compromise more than one-fifth of the investigated sample volume. The diffusion barrier efficiency of a 170 nm thick La{sub 2}Zr{sub 2}O{sub 7} film is investigated by STEM-EELS, yielding a 1.8 {+-} 0.2 nm oxide layer beyond which no significant nickel diffusion can be detected and intermixing is observed. This is of particular significance for the functionality of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} coated conductor architectures based on solution derived La{sub 2}Zr{sub 2}O{sub 7} films as diffusion barriers.

  15. Self-assembling particle-siloxane coatings for superhydrophobic concrete.

    Science.gov (United States)

    Flores-Vivian, Ismael; Hejazi, Vahid; Kozhukhova, Marina I; Nosonovsky, Michael; Sobolev, Konstantin

    2013-12-26

    We report here, for the first time in the literature, a method to synthesize hydrophobic and superhydrophobic concrete. Concrete is normally a hydrophilic material, which significantly reduces the durability of concrete structures and pavements. To synthesize water-repellent concrete, hydrophobic emulsions were fabricated and applied on portland cement mortar tiles. The emulsion was enriched with the polymethyl-hydrogen siloxane oil hydrophobic agent as well as metakaolin (MK) or silica fume (SF) to induce the microroughness and polyvinyl alcohol (PVA) fibers to create hierarchical surfaces. Various emulsion types were investigated by using different mixing procedures, and single- and double-layer hydrophobic coatings were applied. The emulsions and coatings were characterized with optical microscope and scanning electron microscope (SEM), and their wetting properties, including the water contact angle (CA) and roll-off angle, were measured. A theoretical model for coated and non-coated concrete, which can be generalized for other types of materials, was developed to predict the effect of surface roughness and composition on the CA. An optimized distance between the aggregates was found where the CA has the highest value. The maximal CA measured was 156° for the specimen with PVA fibers treated with MK based emulsion. Since water penetration is the main factor leading to concrete deterioration, hydrophobic water-repellent concretes have much longer durability then regular concretes and can have a broad range of applications in civil and materials engineering.

  16. Stabilization of 2D assemblies of silver nanoparticles by spin-coating polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Longyu; Pfirman, Aubrie; Chumanov, George, E-mail: gchumak@clemson.edu

    2015-12-01

    Graphical abstract: - Highlights: • Spin-coating of polymers onto 2D assemblies of Ag NPs was used to stabilize the assemblies against aggregation. • The polymer filled the space between the particles leaving the metal surface uncoated and accessible to various chemical reactions. • Etching nanoparticles produced crater-like structures. - Abstract: Silver nanoparticles self-assembled on poly(4-vinylpyridine) modified surfaces were spin-coated with poly(methyl methacrylate), poly(butyl methacrylate) and polystyrene from anisole and toluene solutions. The polymers filled the space between the particles thereby providing stabilization of the assemblies against particle aggregation when dried or chemically modified. The polymers did not coat the top surface of the nanoparticles offering the chemical accessibility to the metal surface. This was confirmed by converting the stabilized nanoparticles into silver sulfide and gold clusters. Etching the nanoparticles resulted in crater-like polymeric structures with the cavities extending down to the underlying substrate. Electrochemical reduction of silver inside the craters was performed. The approach can be extended to other nanoparticle assemblies and polymers.

  17. Electrochemical Sensor Coating Based on Electrophoretic Deposition of Au-Doped Self-Assembled Nanoparticles.

    Science.gov (United States)

    Zhang, Rongli; Zhu, Ye; Huang, Jing; Xu, Sheng; Luo, Jing; Liu, Xiaoya

    2018-02-14

    The electrophoretic deposition (EPD) of self-assembled nanoparticles (NPs) on the surface of an electrode is a new strategy for preparing sensor coating. By simply changing the deposition conditions, the electrochemical response for an analyte of deposited NPs-based coating can be controlled. This advantage can decrease the difference between different batches of sensor coating and ensure the reproducibility of each sensor. This work investigated the effects of deposition conditions (including deposition voltage, pH value of suspension, and deposition time) on the structure and the electrochemical response for l-tryptophan of sensor coating formed from Au-doped poly(sodium γ-glutamate) with pendant dopamine units nanohybrids (Au/γ-PGA-DA NBs) via the EPD method. The structure and thickness of the deposited sensor coating were measured by atomic force microscopy, which demonstrated that the structure and thickness of coating can be affected by the deposition voltage, the pH value of the suspension, and the deposition time. The responsive current for l-tryptophan of the deposited sensor coating were measured by differential pulse voltammetry, which showed that the responsive current value was affected by the structure and thickness of the deposited coating. These arguments suggested that a rich design-space for tuning the electrochemical response for analyte and a source of variability in the structure of sensor coating can be provided by the deposition conditions. When Au/γ-PGA-DA NBs were deposited on the electrode surface and formed a continuous coating with particle morphology and thinner thickness, the deposited sensor coating exhibited optimal electrochemical response for l-tryptophan.

  18. Enhanced flux pinning and critical currents in YBa2Cu3O7-δ films by nanoparticle surface decoration: Extension to coated conductor templates

    Science.gov (United States)

    Aytug, T.; Paranthaman, M.; Leonard, K. J.; Kim, K.; Ijaduola, A. O.; Zhang, Y.; Tuncer, E.; Thompson, J. R.; Christen, D. K.

    2008-08-01

    Interfacial engineering via nanoparticle substrate surface decoration has been extended to coated conductor templates. Preformed BaTiO3 and BaZrO3 nanoparticles were applied to substrate surfaces, prior to YBa2Cu3O7-δ (YBCO) deposition, by using a scalable and inexpensive technique of solution-based suspension. Compared to untreated reference samples, nanodecoration yields improved in-field critical current density (Jc) as well as strong correlated pinning along the c-axis direction of the YBCO film. Accordingly, a much reduced falloff of Jc with magnetic field strength was observed in all of the modified samples. In addition, scaling behavior of the normalized volume pinning force density (Fp) with respect to temperature provided insight as to the differences in flux pinning mechanisms dependent on the decoration technique. Finally, with these results our earlier proof-of-concept demonstrations on nanoparticle modified single crystal substrates were replicated on technological substrates, pointing to the versatility of this simple technique for realization of enhanced high temperature superconductor performance.

  19. Adhesion of two physically contacting planar substrates coated with layer-by-layer assembled films.

    Science.gov (United States)

    Matsukuma, Daisuke; Aoyagi, Takao; Serizawa, Takeshi

    2009-09-01

    Adhesives composed of synthetic and low-cost molecules that are based on simple chemical principles are attractive because of their versatility. In this article, we report adhesion between two planar substrates coated with layer-by-layer (LbL) assembled films of cationic poly(diallyldimethylammonium chloride) (PDDA) and anionic poly(sodium styrenesulfonate) (PSS) and perform lap shear measurements of the adhered substrates. Films prepared on the substrates functioned as adhesives when one substrate coated with the PDDA-surface film contacted the other surface coated with the PSS-surface film under adequate pressure in the presence of water droplets, suggesting that two films adhered on the basis of polyion complex formation. Observations suggested that the adhesives failed at the substrate-film interface rather than at the bulk films. The adhesion was compared between film-coated substrates and noncoated ones. Confocal laser scanning microscopic observation of adhesives composed of fluorescently labeled poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) revealed that the labeled PAH assembled on one substrate was well dispersed, even in a nonlabeled film assembled on another substrate. It was therefore confirmed that after adhesion in the presence of the water component, the polyelectrolytes became intermixed between the glassy films, resulting in changes in the adhesive structure at the substrate-film interface.

  20. Design and self-assembly of simple coat proteins for artificial viruses

    Science.gov (United States)

    Hernandez-Garcia, Armando; Kraft, Daniela J.; Janssen, Anne F. J.; Bomans, Paul H. H.; Sommerdijk, Nico A. J. M.; Thies-Weesie, Dominique M. E.; Favretto, Marco E.; Brock, Roland; de Wolf, Frits A.; Werten, Marc W. T.; van der Schoot, Paul; Stuart, Martien Cohen; de Vries, Renko

    2014-09-01

    Viruses are among the simplest biological systems and are highly effective vehicles for the delivery of genetic material into susceptible host cells. Artificial viruses can be used as model systems for providing insights into natural viruses and can be considered a testing ground for developing artificial life. Moreover, they are used in biomedical and biotechnological applications, such as targeted delivery of nucleic acids for gene therapy and as scaffolds in material science. In a natural setting, survival of viruses requires that a significant fraction of the replicated genomes be completely protected by coat proteins. Complete protection of the genome is ensured by a highly cooperative supramolecular process between the coat proteins and the nucleic acids, which is based on reversible, weak and allosteric interactions only. However, incorporating this type of supramolecular cooperativity into artificial viruses remains challenging. Here, we report a rational design for a self-assembling minimal viral coat protein based on simple polypeptide domains. Our coat protein features precise control over the cooperativity of its self-assembly with single DNA molecules to finally form rod-shaped virus-like particles. We confirm the validity of our design principles by showing that the kinetics of self-assembly of our virus-like particles follows a previous model developed for tobacco mosaic virus. We show that our virus-like particles protect DNA against enzymatic degradation and transfect cells with considerable efficiency, making them promising delivery vehicles.

  1. Super-Hydrophobic/Icephobic Coatings Based on Silica Nanoparticles Modified by Self-Assembled Monolayers

    Directory of Open Access Journals (Sweden)

    Junpeng Liu

    2016-12-01

    Full Text Available A super-hydrophobic surface has been obtained from nanocomposite materials based on silica nanoparticles and self-assembled monolayers of 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS using spin coating and chemical vapor deposition methods. Scanning electron microscope images reveal the porous structure of the silica nanoparticles, which can trap small-scale air pockets. An average water contact angle of 163° and bouncing off of incoming water droplets suggest that a super-hydrophobic surface has been obtained based on the silica nanoparticles and POTS coating. The monitored water droplet icing test results show that icing is significantly delayed by silica-based nano-coatings compared with bare substrates and commercial icephobic products. Ice adhesion test results show that the ice adhesion strength is reduced remarkably by silica-based nano-coatings. The bouncing phenomenon of water droplets, the icing delay performance and the lower ice adhesion strength suggest that the super-hydrophobic coatings based on a combination of silica and POTS also show icephobicity. An erosion test rig based on pressurized pneumatic water impinging impact was used to evaluate the durability of the super-hydrophobic/icephobic coatings. The results show that durable coatings have been obtained, although improvement will be needed in future work aiming for applications in aerospace.

  2. Nanostructured Architectures by Assembling Polysaccharide-Coated BSA Nanoparticles for Biomedical Application.

    Science.gov (United States)

    Wang, Zhenming; Wang, Kefeng; Lu, Xiong; Li, Chen; Han, Lu; Xie, Chaoming; Liu, Yaling; Qu, Shuxin; Zhen, Guanming

    2015-04-22

    Nanostructured architectures are produced on Ti surfaces by layer-by layer (LbL) self-assembling of polysaccharide-coated BSA nanoparticles (BNPs), which created cellular microenvironments mimicking natural extracellular matrix. The BMP-2 encapsulated BNPs are prepared by a desolvation method, and are further coated by chitosan (CHI) coatings to obtain positively charged NPs (CBNPs). Vancomycin (Van) encapsulated CBNPs are obtained by the same method and subsequently coated by oxidized alginate (OALG) to obtain negatively charged NPs (OCBNPs). The CBNPs and OCBNPs are assembled on Ti surfaces to construct nanostructured coatings via electrostatic and covalent interactions. The nanostructured architectures realize the sustained release of BMP-2 and Van for a long term. Bone marrow stromal cells (BMSCs) culture tests confirm that the bare nanostructured architectures intrinsically facilitate attachment, proliferation, and differentiation of cells, which is attributed to the nanoscale porous structures that are similar to the size of cellular filopodia. Incorporating BMP-2 into the nanostructured architectures significantly enhances osteogenetic differentiation of BMSCs, which reveals the synergistic effects of nanostructures and growth factors on cell activity. The antibacterial tests indicate that controlled release of Van has good antibacterial ability against Staphylococcus epidermidis, while not affecting the normal biological activity of BMSCs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Nanostructured medical device coatings based on self-assembled poly(lactic-co-glycolic acid) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Dayyoub, Eyas [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, 35037 Marburg (Germany); Hobler, Christian [Department of Pharmaceutical Chemistry, Marburg University, 35037 Marburg (Germany); Nonnweiler, Pierina [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, 35037 Marburg (Germany); Keusgen, Michael [Department of Pharmaceutical Chemistry, Marburg University, 35037 Marburg (Germany); Bakowsky, Udo, E-mail: ubakowsky@aol.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, 35037 Marburg (Germany)

    2013-07-01

    Here we present a new method for providing nanostructured drug-loaded polymer films which enable control of film surface morphology and delivery of therapeutic agents. Silicon wafers were employed as models for implanted biomaterials and poly(lactic-co-glycolic acid) (PLGA) nanoparticles were assembled onto the silicon surface by electrostatic interaction. Monolayers of the PLGA particles were deposited onto the silicon surface upon incubation in an aqueous particle suspension. Particle density and surface coverage of the silicon wafers were varied by altering particle concentration, incubation time in nanoparticle suspension and ionic strength of the suspension. Dye loaded nanoparticles were prepared and assembled to silicon surface to form nanoparticle films. Fluorescence intensity measurements showed diffusion-controlled release of the dye over two weeks and atomic force microscopy (AFM) analysis revealed that these particles remained attached to the surface during the incubation time. This work suggests that coating implants with PLGA nanoparticles is a versatile technique which allows drug release from the implant surface and modulation of surface morphology. - Highlights: • Mono-layer PLGA nanoparticle coatings were fabricated on silicon wafers by electrostatic interactions. • Surface coverage with the particles (coating morphology) was varied by changing preparation parameters. • The coatings were loaded with fluorescence dye and this was released in PBS. • The coatings have the potential to alter surface morphology in nanorange and release biomolecules.

  4. Self-assembled peptides for coating of active sulfur nanoparticles in lithium–sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Jewel, Yead; Yoo, Kisoo; Liu, Jin; Dutta, Prashanta, E-mail: prashanta@wsu.edu [Washington State University, School of Mechanical and Materials Engineering (United States)

    2016-03-15

    Development of lithium–sulfur (Li–S) battery is hindered by poor cyclability due to the loss of sulfur, although Li–S battery can provide high energy density. Coating of sulfur nanoparticles can help maintain active sulfur in the cathode of Li–S battery, and hence increase the cyclability. Among myriad of coating materials, synthetic peptides are very attractive because of their spontaneous self-assembly as well as electrical conductive characteristics. In this study, we explored the use of various synthetic peptides as a coating material for sulfur nanoparticles. Atomistic simulations were carried out to identify optimal peptide structure and density for coating sulfur nanoparticles. Three different peptide models, poly-proline, poly(leucine–lysine) and poly-histidine, are selected for this study based on their peptide–peptide and peptide-sulfur interactions. Simulation results show that both poly-proline and poly(leucine–lysine) can form self-assembled coating on sulfur nanoparticles (2–20 nm) in pyrrolidinone, a commonly used solvent for cathode slurry. We also studied the structural integrity of these synthetic peptides in organic [dioxolane (DOL) and dimethoxyethane (DME)] electrolyte used in Li–S battery. Both peptides show stable structures in organic electrolyte (DOL/DME) used in Li–S battery. Furthermore, the dissolution of sulfur molecules in organic electrolyte is investigated in the absence and presence of these peptide coatings. It was found that only poly(leucine–lysine)-based peptide can most effectively suppress the sulfur loss in electrolyte, suggesting its potential applications in Li–S battery as a coating material.Graphical abstract.

  5. Spray coating of crack templates for the fabrication of transparent conductors and heaters on flat and curved surfaces.

    Science.gov (United States)

    Gupta, Ritu; Rao, K D M; Srivastava, Kartikeya; Kumar, Ankush; Kiruthika, S; Kulkarni, Giridhar U

    2014-08-27

    Transparent conducting electrodes (TCEs) have been made on flat, flexible, and curved surfaces, following a crack template method in which a desired surface was uniformly spray-coated with a crackle precursor (CP) and metal (Ag) was deposited by vacuum evaporation. An acrylic resin (CP1) and a SiO2 nanoparticle-based dispersion (CP2) derived from commercial products served as CPs to produce U-shaped cracks in highly interconnected networks. The crack width and the density could be controlled by varying the spray conditions, resulting in varying template thicknesses. By depositing Ag in the crack regions of the templates, we have successfully produced Ag wire network TCEs on flat-flexible PET sheets, cylindrical glass tube, flask and lens surface with transmittance up to 86%, sheet resistance below 11 Ω/□ for electrothermal application. When used as a transparent heater by joule heating of the Ag network, AgCP1 and AgCP2 on PET showed high thermal resistance values of 515 and 409 °C cm(2)/W, respectively, with fast response (<20 s), requiring only low voltages (<5 V) to achieve uniform temperatures of ∼100 °C across large areas. Similar was the performance of the transparent heater on curved glass surfaces. Spray coating in the context of crack template is a powerful method for producing transparent heaters, which is shown for the first time in this work. AgCP1 with an invisible wire network is suited for use in proximity while AgCP2 wire network is ideal for use in large area displays viewed from a distance. Both exhibited excellent defrosting performance, even at cryogenic temperatures.

  6. One-step polypyrrole coating of self-assembled silver nanoprisms for enhanced stability and Raman scattering

    Science.gov (United States)

    Jeong, Dong-Won; Jeong, Sugyeong; Jang, Du-Jeon

    2017-07-01

    Self-assemblies of silver nanoprisms (AgPRs) having enhanced structural stability and optical properties have been facilely coated with polypyrrole (PPy) via the in situ polymerization of pyrrole monomers that also act as an assembling agent. The assemblies of AgPRs, whose edge lengths and thicknesses are typically 78 and 4 nm, respectively, have been surrounded by a PPy coating of 6 nm. AgPRs are assembled in a side-to-side orientation, and the degree of assembly has been controlled by varying the concentration of trisodium citrate dihydrate, which attaches selectively to the {111} facets of AgPRs. The morphology deformation time of PPy-coated AgPRs in 0.6 mM H2O2(aq) is seven times longer than that of PPy-free AgPRs, suggesting that PPy coating prevents the sharp tips of AgPRs from being truncated by oxidizing agents. The SERS effect of highly self-assembled and PPy-coated AgPRs becomes as high as 6.3 due to numerous hot spots generated between nanoprisms. Overall, our fabricated AgPRs assemblies with PPy coating have not only improved structural stability but also enhanced optical properties, extending the practical use of noble-metal nanoprisms for various optical applications.

  7. Conformal dip-coating of patterned surfaces for capillary die-to-substrate self-assembly

    Science.gov (United States)

    Mastrangeli, M.; Ruythooren, W.; Van Hoof, C.; Celis, J.-P.

    2009-04-01

    Capillarity-driven self-assembly of small chips onto planar target substrates is a promising alternative to robotic pick-and-place assembly. It critically relies on the selective deposition of thin fluid films on patterned binding sites, which is anyway normally non-conformal. We found that the addition of a thin wetting sidewall, surrounding the entire site perimeter, enables the conformal fluid coverage of arbitrarily shaped sites through dip-coating, significantly improves the reproducibility of the coating process and strongly reduces its sensitivity to surface defects. In this paper we support the feasibility and potential of this method by demonstrating the conformal dip-coating of square and triangular sites conditioned with combinations of different hydrophobic and hydrophilic surface chemistries. We present both experimental and simulative evidence of the advantages brought by the introduction of the wetting boundary on film coverage accuracy. Application of our surface preparation method to capillary self-assembly could result in higher precision in die-to-substrate registration and larger freedom in site shape design.

  8. High-Resolution Spore Coat Architecture and Assembly of Bacillus Spores

    Energy Technology Data Exchange (ETDEWEB)

    Malkin, A J; Elhadj, S; Plomp, M

    2011-03-14

    Elucidating the molecular architecture of bacterial and cellular surfaces and its structural dynamics is essential to understanding mechanisms of pathogenesis, immune response, physicochemical interactions, environmental resistance, and provide the means for identifying spore formulation and processing attributes. I will discuss the application of in vitro atomic force microscopy (AFM) for studies of high-resolution coat architecture and assembly of several Bacillus spore species. We have demonstrated that bacterial spore coat structures are phylogenetically and growth medium determined. We have proposed that strikingly different species-dependent coat structures of bacterial spore species are a consequence of sporulation media-dependent nucleation and crystallization mechanisms that regulate the assembly of the outer spore coat. Spore coat layers were found to exhibit screw dislocations and two-dimensional nuclei typically observed on inorganic and macromolecular crystals. This presents the first case of non-mineral crystal growth patterns being revealed for a biological organism, which provides an unexpected example of nature exploiting fundamental materials science mechanisms for the morphogenetic control of biological ultrastructures. We have discovered and validated, distinctive formulation-specific high-resolution structural spore coat and dimensional signatures of B. anthracis spores (Sterne strain) grown in different formulation condition. We further demonstrated that measurement of the dimensional characteristics of B. anthracis spores provides formulation classification and sample matching with high sensitivity and specificity. I will present data on the development of an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures on the B. anthracis surfaces. These studies demonstrate that AFM can probe microbial surface architecture, environmental dynamics and the life cycle of bacterial and cellular systems at near

  9. Growth of thick La{sub 2}Zr{sub 2}O{sub 7} buffer layers for coated conductors by polymer-assisted chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin, E-mail: xzhang@my.swjtu.edu.cn [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Yong, E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Xia, Yudong [State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Guo, Chunsheng [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Zhang, Yong [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhang, Han [Department of Physics, Peking University, Beijing 100871 (China)

    2015-06-15

    Highlights: • We develops a low-cost and high-efficient technology of fabricating LZO buffer layers. • Sufficient thickness LZO buffer layers have been obtained on NiW (2 0 0) alloy substrate. • Highly biaxially textured YBCO thin film has been deposited on LZO/NiW. - Abstract: La{sub 2}Zr{sub 2}O{sub 7} (LZO) epitaxial films have been deposited on LaAlO{sub 3} (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa{sub 2}Cu{sub 3}O{sub 7−x} (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm{sup 2} at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors.

  10. YBCO/Nd{sub 2}CuO{sub 4}/NiO/Ni coated conductors fabricated by liquid phase epitaxy based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X [Department of Materials and Centre for High Temperature Superconductivity, Imperial College, London SW7 2BP (United Kingdom); Lockman, Z [Department of Materials and Centre for High Temperature Superconductivity, Imperial College, London SW7 2BP (United Kingdom); Bugoslavsky, Y [Department of Materials and Centre for High Temperature Superconductivity, Imperial College, London SW7 2BP (United Kingdom); Kursumovic, A [Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Tomov, R [Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Glowacki, B A [Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Evetts, J E [Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); MacManus-Driscoll, J L [Department of Materials and Centre for High Temperature Superconductivity, Imperial College, London SW7 2BP (United Kingdom)

    2004-10-01

    Liquid phase epitaxy (LPE) has a great potential in producing low-cost, high-current, coated conductors due to its fast growth rate in excess of 1 {mu}m min{sup -1} and the capability of growing thick films up to 10 {mu}m without degrading the structural perfection or J{sub c}. The main problem for LPE is the chemical reaction between the films and substrates at elevated growth temperatures. Former efforts have been focused on the reduction of growth temperatures. This has been proved to be unsuccessful due to the limited degree of temperature reduction; reducing the growth temperature also reduces the solubility of YBCO in the liquid, making the growth even more difficult. An alternative solution to this problem is to search for a special buffer which is particularly resistant to the attack of the high-temperature liquid. We have recently developed a new buffer, Nd{sub 2}CuO{sub 4}, which was very stable in the cuprate solution at temperatures around 950 deg. C and therefore extremely useful for LPE. Initial growth of YBCO on Nd{sub 2}CuO{sub 4} buffered, surface oxidized Ni substrates showed a sharp superconducting transition at 90 K and transport J{sub c} over 10{sup 5} A cm{sup -2} (77 K). Although YBCO could be grown on Nd{sub 2}CuO{sub 4} by LPE without any other intermediate seed layer, growth of Nd{sub 2}CuO{sub 4} on both sides of the NiO/Ni substrate with 100% coverage was not easy and had a low success rate. Complete coverage of Nd{sub 2}CuO{sub 4} buffer on the NiO/Ni substrates was the critical step to avoid Ni contamination and achieve a high J{sub c}.

  11. Stable silica-coated self-assembly of gold nanorods: synthesis and plasmonic properties

    Science.gov (United States)

    Liu, Jinsheng; Kan, Caixia; Shi, Daning; Ke, Shanlin; Liu, Yangzheng

    2017-10-01

    Assembled gold nanorods (GNRs) attract much attention for their distinctive plasmon-coupled properties, but it remains challenging to realize practical use for their instability of the structure and the toxicity of the surfactant. We herein present a simple and effective protocol to coat mesoporous silica on the end-to-end and side-by-side assemblies, which are induced by different amount of the dithiol poly(ethylene glycol). The finite-difference time-domain (FDTD) simulations are also utilized to study the plasmonic properties of the nanostructures. Experimental and calculated results indicate that the as-prepared core-shell nanostructure possesses not only the optical stability, but also the fascinating and tunable optical response through changing the organized modes of assemblies. The result is promising in investigating near field plasmonic property, and biomedical application for in vivo bioimaging and photothermal cancer therapy.

  12. Mussel-inspired nanostructured coatings assembled using polydopamine nanoparticles and hydroxyapatite nanorods for biomedical applications

    Directory of Open Access Journals (Sweden)

    Zhenming Wang

    2017-03-01

    Full Text Available Producing hierarchical nanostructured coatings with a biomimetic composition is an effective surface modification strategy to improve the bioactivity of biomaterials. In this study, mussel-inspired polydopamine nanoparticles (PDA-NPs and hydroxyapatite (HA nanorods were used to modify Ti surfaces. Firstly, the PDA-NPs were prepared via oxidative self-polymerization of dopamine. Secondly, the HA nanorods were decorated with a PDA nanolayer in order to improve the adhesion of the HA nanorods. Thirdly, the PDA-NPs and PDA-decorated HA nanorods were alternately assembled to form a porous and hierarchical micro/nanostructured {PDA/HA} composite coating on the Ti surfaces. Finally, Bone ​morphogenetic protein-2 (BMP-2 was immobilized on the {PDA/HA} composite coating using the functional groups of PDA. The BMP-2-loaded {PDA/HA} composite coating exhibited excellent biocompatibility and promoted the adhesion, proliferation, and differentiation of bone marrow stromal cells. The animal implantation tests indicated that the BMP-2-loaded {PDA/HA} composite coating promoted the formation of new bone tissue.

  13. Thin silica shell coated Ag assembled nanostructures for expanding generality of SERS analytes.

    Directory of Open Access Journals (Sweden)

    Myeong Geun Cha

    Full Text Available Surface-enhanced Raman scattering (SERS provides a unique non-destructive spectroscopic fingerprint for chemical detection. However, intrinsic differences in affinity of analyte molecules to metal surface hinder SERS as a universal quantitative detection tool for various analyte molecules simultaneously. This must be overcome while keeping close proximity of analyte molecules to the metal surface. Moreover, assembled metal nanoparticles (NPs structures might be beneficial for sensitive and reliable detection of chemicals than single NP structures. For this purpose, here we introduce thin silica-coated and assembled Ag NPs (SiO2@Ag@SiO2 NPs for simultaneous and quantitative detection of chemicals that have different intrinsic affinities to silver metal. These SiO2@Ag@SiO2 NPs could detect each SERS peak of aniline or 4-aminothiophenol (4-ATP from the mixture with limits of detection (LOD of 93 ppm and 54 ppb, respectively. E-field distribution based on interparticle distance was simulated using discrete dipole approximation (DDA calculation to gain insight into enhanced scattering of these thin silica coated Ag NP assemblies. These NPs were successfully applied to detect aniline in river water and tap water. Results suggest that SiO2@Ag@SiO2 NP-based SERS detection systems can be used as a simple and universal detection tool for environment pollutants and food safety.

  14. Large-scale colloidal self-assembly by doctor blade coating.

    Science.gov (United States)

    Yang, Hongta; Jiang, Peng

    2010-08-17

    This article reports a simple, roll-to-roll compatible coating technology for producing 3D highly ordered colloidal crystal-polymer nanocomposites, colloidal crystals, and macroporous polymer membranes. A vertically beveled doctor blade is utilized to shear align silica microsphere-monomer suspensions to form large-area nanocomposites in a single step. The polymer matrix and the silica microspheres can be selectively removed to create colloidal crystals and self-standing macroporous polymer membranes. The thickness of the shear-aligned crystal is correlated with the viscosity of the colloidal suspension, and the coating speed and the correlations can be qualitatively explained by adapting the mechanisms developed for conventional doctor blade coating. We further demonstrate that the doctor blade coating speed can be significantly increased by using a dual-blade setup. The optical properties of the self-assembled structures are evaluated by normal-incidence reflection measurements, and the experimental results agree well with the theoretical predictions using Bragg's law and a scalar wave approximation model. We have also demonstrated that the templated macroporous polymers with interconnected voids and uniform interconnecting nanopores can be directly used as filtration membranes to achieve size-exclusive separation of particles.

  15. Parallel nano-assembling of a multifunctional GO/HapNP coating on ultrahigh-purity magnesium for biodegradable implants

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C., E-mail: catarina.santos@estsetubal.ips.pt [EST Setúbal, DEM, Instituto Politécnico de Setúbal, Campus IPS, 2914-508 Setúbal (Portugal); CQE, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Piedade, C. [EST Setúbal, DEM, Instituto Politécnico de Setúbal, Campus IPS, 2914-508 Setúbal (Portugal); Uggowitzer, P.J. [Laboratory of Metal Physics and Technology, ETH Zurich, 8093 Zurich (Switzerland); Montemor, M.F. [CQE, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Carmezim, M.J. [EST Setúbal, DEM, Instituto Politécnico de Setúbal, Campus IPS, 2914-508 Setúbal (Portugal); CQE, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2015-08-01

    Graphical abstract: - Highlights: • A GO/HapNP thin coating was applied on XHP-Mg using a parallel nano-assembling route. • The coating surface wettability can be controlled by adding HapNP and/or GO. • Nanostructured GO/HapNP/phosphate coating promotes the apatite mineralization. • Critical properties, including degradation on SBF, of the coating were studied. - Abstract: This work reports the one-step fabrication of a novel coating on ultra high purity magnesium using a parallel nano assembling process. The multifunctional biodegradable surface was obtained by adding hydroxyapatite nanoparticles (HapNP) plus graphene oxide (GO). The coating was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), micro-Raman spectroscopy. The thin phosphate coating (thickness of 1 μm) reveals a uniform coverage with cypress like structures. The incorporation of HapNP and GO promotes the hydrophilic behavior of the coating surface. The results revealed that the proposed coating can be used to tailor the surface properties such as wettability by adjusting the contents of HapNP and GO. The in vitro degradation rate of the coated magnesium suggests that the presence of HapNP and GO/HapNP in the phosphate coating decreased the current density compared to the single phosphate coating and uncoated magnesium. This study also reveals the HapNP/GO/phosphate coating induces apatite formation, showing suitable degradability that makes it a promising coating candidate for enhanced bone regeneration.

  16. Buffer layers for coated conductors

    Science.gov (United States)

    Stan, Liliana [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM; Foltyn, Stephen R [Los Alamos, NM

    2011-08-23

    A composite structure is provided including a base substrate, an IBAD oriented material upon the base substrate, and a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material. Additionally, an article is provided including a base substrate, an IBAD oriented material upon the base substrate, a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material, and a thick film upon the cubic metal oxide material. Finally, a superconducting article is provided including a base substrate, an IBAD oriented material upon the base substrate, a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material, and an yttrium barium copper oxide material upon the cubic metal oxide material.

  17. A comparison of [0 0 1] low-angle tilt grain boundaries of (1 0 0) and (1 1 0) grain boundary planes in YBa 2Cu 3O 7- δ coated conductors

    Science.gov (United States)

    Kung, H.; Hirth, J. P.; Foltyn, S. R.; Arendt, P. N.; Jia, Q. X.; Maley, M. P.

    2001-08-01

    The microstructure and grain boundary structure in YBa 2Cu 3O 7- δ (YBCO) thick film coated conductors are characterized by transmission electron microscopy. The films contain low-angle [0 0 1] tilt grain boundaries with periodic arrays of edge dislocations parallel to the c-axis. A majority of the grain boundary planes are of either the (1 0 0) or the (1 1 0) type. Grain boundary dislocations (GBDs) with a [1 0 0] Burgers vector were observed in tilt boundaries with (1 0 0) boundary planes. However, partial dislocations, separated by stacking faults, were found at boundaries with near (1 1 0) grain boundary planes. Extensive g· b and g· R analyses confirmed the partials to be of 1/2[1 1 0] type. These results suggest that the characteristics of dislocation structures, which have been proposed in various grain boundary-based flux-pinning models, depend not only on the misorientation angle θ, but also on the types of grain boundary plane. The effect of dissociated GBDs on the transport properties of low angle grain boundaries in YBCO coated conductors is discussed.

  18. Self-Assembled Colloidal Gel Using Cell Membrane-Coated Nanosponges as Building Blocks.

    Science.gov (United States)

    Zhang, Yue; Gao, Weiwei; Chen, Yijie; Escajadillo, Tamara; Ungerleider, Jessica; Fang, Ronnie H; Christman, Karen; Nizet, Victor; Zhang, Liangfang

    2017-11-10

    Colloidal gels consisting of oppositely charged nanoparticles are increasingly utilized for drug delivery and tissue engineering. Meanwhile, cell membrane-coated nanoparticles are becoming a compelling biomimetic system for innovative therapeutics. Here, we demonstrate the successful use of cell membrane-coated nanoparticles as building blocks to formulate a colloidal gel that gelates entirely based on material self-assembly without chemical cross-linking. Specifically, we prepare red blood cell membrane-coated nanosponges and mix them with an appropriate amount of cationic nanoparticles, resulting in a spontaneously formed gel-like complex. Rheological test shows that the nanosponge colloidal gel has pronounced shear-thinning property, which makes it an injectable formulation. The gel formulation not only preserves the nanosponges' toxin neutralization capability but also greatly prolongs their retention time after subcutaneous injection into mouse tissue. When tested in a mouse model of subcutaneous group A Streptococcus infection, the nanosponge colloidal gel shows significant antibacterial efficacy by markedly reducing skin lesion development. Overall, the nanosponge colloidal gel system is promising as an injectable formulation for therapeutic applications such as antivirulence treatment for local bacterial infections.

  19. Advanced drug delivery via self-assembled monolayer-coated nanoparticles

    Directory of Open Access Journals (Sweden)

    Amin Shakiba

    2017-04-01

    Full Text Available Nanotechnology has greatly enhanced the field of medicine over the last decade. Within this field, advances in nanoparticle research have rendered them attractive candidates for drug delivery. Consequently, controlling the chemistry that occurs at the nanoparticle interface influences the efficiency of the drug-delivery system. In this review, we explore the role of coating materials, in the form of self-assembled monolayers (SAMs, in enhancing the interfacial properties of nanoparticles. We discuss how SAMs enhance the properties of particles, such as stability and dispersibility, as well as provide a platform for delivering biomolecules and other therapeutic agents. In addition, we describe recent methods for generating nanoparticles with targeted surface functionality using custom-designed SAMs. These functionalities offer marked advances to the three stages of a drug-delivery system: loading, delivery, and release of therapeutic molecules. A suitable functionalization strategy can provide a means for covalent or non-covalent immobilization of drug molecules. Moreover, a robust coating layer can aid the encapsulation of drug molecules and inhibit molecular degradation during the delivery process. A stimuli-responsive SAM layer can also provide an efficient release mechanism. Thus, we also review how stimuli-responsive coatings allow for the controlled release of therapeutic agents. In addition, we discuss the merits and limitations of stimuli-responsive SAMs as well as possible strategies for future delivery systems. Overall, advances in this research area allow for developing novel drug delivery methodologies with high efficiency and minimal toxicity.

  20. Self-assembled gold coating enhances X-ray imaging of alginate microcapsules

    Science.gov (United States)

    Qie, Fengxiang; Astolfo, Alberto; Wickramaratna, Malsha; Behe, Martin; Evans, Margaret D. M.; Hughes, Timothy C.; Hao, Xiaojuan; Tan, Tianwei

    2015-01-01

    Therapeutic biomolecules produced from cells encapsulated within alginate microcapsules (MCs) offer a potential treatment for a number of diseases. However the fate of such MCs once implanted into the body is difficult to establish. Labelling the MCs with medical imaging contrast agents may aid their detection and give researchers the ability to track them over time thus aiding the development of such cellular therapies. Here we report the preparation of MCs with a self-assembled gold nanoparticle (AuNPs) coating which results in distinctive contrast and enables them to be readily identified using a conventional small animal X-ray micro-CT scanner. Cationic Reversible Addition-Fragmentation chain Transfer (RAFT) homopolymer modified AuNPs (PAuNPs) were coated onto the surface of negatively charged alginate MCs resulting in hybrids which possessed low cytotoxicity and high mechanical stability in vitro. As a result of their high localized Au concentration, the hybrid MCs exhibited a distinctive bright circular ring even with a low X-ray dose and rapid scanning in post-mortem imaging experiments facilitating their positive identification and potentially enabling them to be used for in vivo tracking experiments over multiple time-points.Therapeutic biomolecules produced from cells encapsulated within alginate microcapsules (MCs) offer a potential treatment for a number of diseases. However the fate of such MCs once implanted into the body is difficult to establish. Labelling the MCs with medical imaging contrast agents may aid their detection and give researchers the ability to track them over time thus aiding the development of such cellular therapies. Here we report the preparation of MCs with a self-assembled gold nanoparticle (AuNPs) coating which results in distinctive contrast and enables them to be readily identified using a conventional small animal X-ray micro-CT scanner. Cationic Reversible Addition-Fragmentation chain Transfer (RAFT) homopolymer modified Au

  1. ϕX174 Procapsid Assembly: Effects of an Inhibitory External Scaffolding Protein and Resistant Coat Proteins In Vitro.

    Science.gov (United States)

    Cherwa, James E; Tyson, Joshua; Bedwell, Gregory J; Brooke, Dewey; Edwards, Ashton G; Dokland, Terje; Prevelige, Peter E; Fane, Bentley A

    2017-01-01

    During ϕX174 morphogenesis, 240 copies of the external scaffolding protein D organize 12 pentameric assembly intermediates into procapsids, a reaction reconstituted in vitro In previous studies, ϕX174 strains resistant to exogenously expressed dominant lethal D genes were experimentally evolved. Resistance was achieved by the stepwise acquisition of coat protein mutations. Once resistance was established, a stimulatory D protein mutation that greatly increased strain fitness arose. In this study, in vitro biophysical and biochemical methods were utilized to elucidate the mechanistic details and evolutionary trade-offs created by the resistance mutations. The kinetics of procapsid formation was analyzed in vitro using wild-type, inhibitory, and experimentally evolved coat and scaffolding proteins. Our data suggest that viral fitness is correlated with in vitro assembly kinetics and demonstrate that in vivo experimental evolution can be analyzed within an in vitro biophysical context. Experimental evolution is an extremely valuable tool. Comparisons between ancestral and evolved genotypes suggest hypotheses regarding adaptive mechanisms. However, it is not always possible to rigorously test these hypotheses in vivo We applied in vitro biophysical and biochemical methods to elucidate the mechanistic details that allowed an experimentally evolved virus to become resistant to an antiviral protein and then evolve a productive use for that protein. Moreover, our results indicate that the respective roles of scaffolding and coat proteins may have been redistributed during the evolution of a two-scaffolding-protein system. In one-scaffolding-protein virus assembly systems, coat proteins promiscuously interact to form heterogeneous aberrant structures in the absence of scaffolding proteins. Thus, the scaffolding protein controls fidelity. During ϕX174 assembly, the external scaffolding protein acts like a coat protein, self-associating into large aberrant spherical

  2. Contamination profile of Printed Circuit Board Assemblies in relation to soldering types and conformal coating

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition...... by an appropriate cleaning. Selective soldering process generates significantly higher levels of residues compared to the wave and reflow process. For conformal coated PCBAs, the contamination levels generated from the tested wave and selective soldering process are found to be enough to generate blisters under...... by measuring the leak current using a twin platinum electrode setup. Localized extraction of residue was carried out using a commercial C3 extraction system. Results clearly show that the amount and distribution of flux residues are a function of the soldering process, and the level can be reduced...

  3. Microstructural investigation of phases and pinning properties in MBa2Cu3O7-x (M = Y and/or Gd) coated conductors produced by scale-up facilitie

    Science.gov (United States)

    Jin, Hye-Jin; Moon, Han-Kyoul; Yoon, Seokhyun; Jo, William; Kim, Kunsu; Kim, Miyoung; Ko, Rock-Kil; Jo, Young-Sik; Ha, Dong-Woo

    2016-03-01

    To expedite the commercialization of coated conductors, a robust stacking architecture of the wires must be developed and the performance of the critical currents improved. More importantly, the manufacturability, or large-scale delivery, and the capability of sustaining production at a high rate must be considered. The products of three companies, American Superconductor, Superpower Inc., and SuNAM Co., Ltd, were selected because these companies have announced commercial-grade production lines and delivered a significant amounts of wires to the open market that meet the standards demanded by power devices. X-ray diffraction patterns were used to verify the structural properties and the phase formation in the wires, and transmission electron microscopy with energy dispersive spectroscopy was used to investigate the microstructure and composition of the conductors. In addition, Raman scattering spectroscopy was used for the analysis of the phase formation and for the elucidation of secondary phases in the superconducting layers. The field dependence of the critical current was also studied to compare the transport characteristics under relatively low and medium magnetic field at 77 K and 60 K. Pinning forces were obtained from the field dependence of transport properties and pinning characteristics were investigated. The theoretical and experimental analyses were combined together using the Dew-Hughes formula to extract the scaling exponents and estimate the irreversibility lines of the fields. The results showed that the three conductors possess pinning mechanisms that originate from core pinning with a surface pinning geometry. It is remarkable that the wires discussed in this paper exhibit very similar pinning characteristics even though they have different characteristics in terms of chemical composition, microstructure, stacking architectures, and distribution of parasitic phases.

  4. Layer-by-Layer-Assembled High-Performance Broadband Antireflection Coatings

    KAUST Repository

    Shimomura, Hiroomi

    2010-03-24

    Nanoparticles are indispensable ingredients of solution-processed optical, dielectric, and catalytic thin films. Although solution-based methods are promising low-cost alternatives to vacuum methods, they can have significant limitations. Coating uniformity, thickness control, roughness control, mechanical durability, and incorporation of a diverse set of functional organic molecules into nanoparticle thin films are major challenges. We have used the electrostatic layer-by-layer assembly technique to make uniform, conformal multistack nanoparticle thin films for optical applications with precise thickness control over each stack. Two particularly sought-after optical applications are broadband antireflection and structural color. The effects of interstack and surface roughness on optical properties of these constructs (e.g., haze and spectral response) have been studied quantitatively using a combination of Fourier-transform methods and atomic force microscopy measurements. Deconvoluting root-mean-square roughness into its large-, intermediate-, and small-scale components enables enhanced optical simulations. A 4-stack broadband antireflection coating (<0.5% average reflectance in the visible range, and 0.2% haze) composed of alternating high-index (n ≈ 1.96) and low-index (n ≈ 1.28) stacks has been made on glass substrate. Films calcinated at 550 °C endure a one-hour-long cloth cleaning test under 100 kPa normal stress. © 2010 American Chemical Society.

  5. International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Failures and Lessons Learned

    Science.gov (United States)

    Balistreri, Steven F.; Shaw, Laura A.; Laliberte, Yvon

    2010-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within in the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings and potential remediation techniques will also be discussed.

  6. Final Report: Superconducting Joints Between (RE)Ba2Cu3O7-x Coated Conductors via Electric Field Assisted Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Justin [North Carolina State Univ., Raleigh, NC (United States)

    2017-05-23

    Here we report the results from a project aimed at developing a fully superconducting joint between two REBCO coated conductors using electric field processing (EFP). Due to a reduction in the budget and time period of this contract, we reduced the project scope and focused first on the key scientific issues for forming a strong bond between conductors, and subsequently focused on improving through-the-joint transport. A modified timeline and task list is shown in Table 1, summarizing accomplishments to date. In the first period, we accomplished initial surface characterization as well as rounds of EFP experiments to begin to understand processing parameters which produce well-bonded tapes. In the second phase, we explored the effects of two fundamental EFP parameters, voltage and pressure, and the limitations they place on the process. In the third phase, we achieved superconducting joints and established base characteristics of both the bonding process and the types of tapes best suited to this process. Finally, we investigated some of the parameters related to kinetics which appeared inhibit joint quality and performance.

  7. Photoactive nanocomplex formed from chlorophyll assembly on TMA-coated iron oxide nanoparticles

    Science.gov (United States)

    Barbaros, Sibel; Meray, Zeynep; Tecim, Tuğba; Genç, Rükan

    2016-07-01

    In this study, hierarchical self-assembly of photocatalytic nanodisks through non-covalent interactions between spinach-extracted chlorophyll molecules and trimethylammonium hydroxide-coated magnetic iron oxide nanoparticles was discussed. Combination of chlorophyll molecules with iron oxide nanoparticles generated an alteration in light absorption at both visible and near-IR region with accompanying enhancement in fluorescence emission. Further, photocatalytic role of resulting molecular assembly was studied by means of the photoinduced degradation of methylene blue dye under UV light and direct sun irradiation at neutral pH. In order to enhance the long-term stability of the hybrid nanocatalyst, commercially available cellulose membrane was used as a support and magnetic recovery and reusability was achieved where the nanocatalyst retained more than 90 % of its efficiency even after four cycles. This simple strategy could initiate the development of new materials for wastewater treatment including membrane-based technologies. On the other hand, their sunlight-induced photocatalytic activity could easily be conducted to dye-synthesized solar cells or their enhanced photoluminescence can provide a strong basis for future bioimaging tools.

  8. Photoactive nanocomplex formed from chlorophyll assembly on TMA-coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Barbaros, Sibel; Meray, Zeynep; Tecim, Tuğba; Genç, Rükan, E-mail: rukangnc@gmail.com [Mersin University, Functional Nanomaterials Laboratory, Chemical Engineering Department, Engineering Faculty (Turkey)

    2016-07-15

    In this study, hierarchical self-assembly of photocatalytic nanodisks through non-covalent interactions between spinach-extracted chlorophyll molecules and trimethylammonium hydroxide-coated magnetic iron oxide nanoparticles was discussed. Combination of chlorophyll molecules with iron oxide nanoparticles generated an alteration in light absorption at both visible and near-IR region with accompanying enhancement in fluorescence emission. Further, photocatalytic role of resulting molecular assembly was studied by means of the photoinduced degradation of methylene blue dye under UV light and direct sun irradiation at neutral pH. In order to enhance the long-term stability of the hybrid nanocatalyst, commercially available cellulose membrane was used as a support and magnetic recovery and reusability was achieved where the nanocatalyst retained more than 90 % of its efficiency even after four cycles. This simple strategy could initiate the development of new materials for wastewater treatment including membrane-based technologies. On the other hand, their sunlight-induced photocatalytic activity could easily be conducted to dye-synthesized solar cells or their enhanced photoluminescence can provide a strong basis for future bioimaging tools.Graphical Abstract.

  9. Model-Based Control of a Continuous Coating Line for Proton Exchange Membrane Fuel Cell Electrode Assembly

    Directory of Open Access Journals (Sweden)

    Vikram Devaraj

    2015-01-01

    Full Text Available The most expensive component of a fuel cell is the membrane electrode assembly (MEA, which consists of an ionomer membrane coated with catalyst material. Best-performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane; however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. A continuous coating line can reduce the cost and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. A pilot-scale membrane coating line was designed for such a task and is described in this paper. Accurate process control is necessary to prevent manufacturing defects from occurring in the coating line. A linear-quadratic-Gaussian (LQG controller was developed based on a physics-based model of the coating process to optimally control the temperature and humidity of the drying zones. The process controller was implemented in the pilot-scale coating line proving effective in preventing defects.

  10. Enhanced room-temperature magnetoresistance in self-assembled Ag-coated multiphasic chromium oxide nanocomposites.

    Science.gov (United States)

    Dwivedi, S; Biswas, S

    2016-09-14

    Self-assembled Ag-coated multiphasic diluted magnetic chromium oxide nanocomposites were developed by a facile chemical synthesis route involving a reaction of CrO3 in the presence of Ag(+) ions in an aqueous solution of poly-vinyl alcohol (PVA) and sucrose. The tiny ferromagnetic single domains of tetragonal and orthorhombic CrO2 (t-CrO2 and o-CrO2) embedded in a dominantly insulating matrix of antiferromagnetic Cr2O3 and Cr3O8, and paramagnetic CrO3 and Cr2O, with a correlated diamagnetic thin and discontinuous shell layer of Ag efficiently tailor useful magnetic and room-temperature magnetoresistance (RTMR) properties. The t-CrO2, o-CrO2, possible canted ferromagnetism due to spin disorder in the matrix components, and the associated exchange interactions are the elements responsible for the observed ferromagnetism in the composite structure. The chain of ferromagnetic centers embedded in the composite matrix constitutes a type of magnetic tunnel junction through which spin-polarized electrons can effectively move without significant local interruptions. Electrical transport measurements showed that the spin-dependent tunneling (SDT) mechanism in the engineered microstructure of the nanocomposites exists even at room temperature (RT). A typical sample unveils a markedly enhanced RTMR-value, e.g., -80% at an applied field (H) of 3 kOe, compared to the reported values for compacted CrO2 powders or composites. The enhanced RTMR-value observed in the Coulomb blockade regime appears not only due to the considerably suppressed spin flipping at RT but primarily due to a highly effective SDT mechanism through an interlinked structure of Ag-coated multiphasic chromium oxide nanocomposites.

  11. Catechol-based layer-by-layer assembly of composite coatings: a versatile platform to hierarchical nano-materials.

    Science.gov (United States)

    Wang, C X; Braendle, A; Menyo, M S; Pester, C W; Perl, E E; Arias, I; Hawker, C J; Klinger, D

    2015-08-21

    Inspired by the marine mussel's ability to adhere to surfaces underwater, an aqueous catechol-based dip coating platform was developed. Using a catechol-functionalized polyacrylamide binder in combination with inorganic nanoparticles enables the facile fabrication of robust composite coatings via a layer-by-layer process. This modular assembly of well-defined building blocks provides a versatile alternative to electrostatic driven approaches with layer thickness and refractive indices being readily tunable. The platform nature of this approach enables the fabrication of hierarchically ordered nano-materials such as Bragg stacks.

  12. Kinetic Effects on Self-Assembly and Function of Protein-Polymer Bioconjugates in Thin Films Prepared by Flow Coating

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Dongsook [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Huang, Aaron [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA; Olsen, Bradley D. [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave Cambridge MA 02142 USA

    2016-11-04

    The self-assembly of nanostructured globular protein arrays in thin films is demonstrated using protein–polymer block copolymers based on a model protein mCherry and the polymer poly(oligoethylene glycol acrylate) (POEGA). Conjugates are flow coated into thin films on a poly(ethylene oxide) grafted Si surface, forming self-assembled cylindrical nanostructures with POEGA domains selectively segregating to the air–film interface. Long-range order and preferential arrangement of parallel cylinders templated by selective surfaces are demonstrated by controlling relative humidity. Long-range order increases with coating speed when the film thicknesses are kept constant, due to reduced nucleation per unit area of drying film. Fluorescence emission spectra of mCherry in films prepared at <25% relative humidity shows a small shift suggesting that proteins are more perturbed at low humidity than high humidity or the solution state.

  13. Electrochemical performance of Li-rich oxide composite material coated with Li{sub 0.75}La{sub 0.42}TiO{sub 3} ionic conductor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chun-Chen, E-mail: ccyang@mail.mcut.edu.tw [Battery Research Center of Green Energy, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Liao, Pin-Ci [Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Wu, Yi-Shiuan [Battery Research Center of Green Energy, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Lue, Shingjiang Jessie [Department of Chemical and Materials Engineering, and Green Technology Research Center, Chang Gung University, Kwei-shan, Tao-yuan 333, Taiwan , ROC (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Tao-yuan 333, Taiwan, ROC (China); Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, NewTaipei City 243, Taiwan, ROC (China)

    2017-03-31

    Graphical abstract: Schematic diagram for Li-rich oxide (Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2}) coated with Li{sub 0.75}La{sub 0.42}TiO{sub 3} (LLTO) solid ionic conductor. - Highlights: • Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2}/C composite material was prepared by one-pot solid-state method. • 1D a-MnO{sub 2} nanowires and microsphere hollow b-Ni(OH){sub 2} were prepared by a hydrothermal method. • 1 wt.%LLTO-coated composite showed the best performance among samples. • LLTO layer not only improves the ionic transport of Li-rich oxide material, but also prevent Li-rich material corrosion. - Abstract: Li-rich (spray-dried (SP)-Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2}) composite materials were prepared via two-step ball-mill and spray dry methods by using LiOH, α-MnO{sub 2}, β-Ni(OH){sub 2} raw materials. Two raw materials of α-MnO{sub 2} nanowires and microsphere β-Ni(OH){sub 2} were synthesized by a hydrothermal process. In addition, Li{sub 0.75}La{sub 0.42}TiO3 (LLTO) fast ionic conductor was coated on SP-Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2} composite via a sol–gel method. The properties of the LLTO-coated SP-Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2} composites were determined by X-ray diffraction, scanning electron microscopy, micro-Raman, XPS, and the AC impedance method. The discharge capacities of 1 wt.%-LLTO-coated SP-Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2} composites were 256, 250, 231, 200, 158, and 114 mAh g{sup {sub −}{sub 1}} at rates of 0.1, 0.2, 0.5, 1, 3, and 5C, respectively, in the voltage range 2.0–4.8 V. The 1 wt.%-LLTO-coated Li-rich oxide composite showed the discharge capacities of up to 256 mAh g{sup −1} in the first cycle at 0.1C. After 30 cycles, the discharge capacity of 244 mAh g{sup −1} was obtained, which showed the capacity retention of 95.4%.

  14. Extreme Activity of Drug Nanocrystals Coated with A Layer of Non-Covalent Polymers from Self-Assembled Boric Acid

    Science.gov (United States)

    Zhan, Honglei; Liang, Jun F.

    2016-12-01

    Non-covalent polymers have remarkable advantages over synthetic polymers for wide biomedical applications. In this study, non-covalent polymers from self-assembled boric acid were used as the capping reagent to replace synthetic polymers in drug crystallization. Under acidic pH, boric acid self-assembled on the surface of drug nanocrystals to form polymers with network-like structures held together by hydrogen bonds. Coating driven by boric acid self-assembly had negligible effects on drug crystallinity and structure but resulted in drug nanocrystals with excellent dispersion properties that aided in the formation of a more stable suspension. Boric acid coating improved drug stability dramatically by preventing drug molecules from undergoing water hydrolysis in a neutral environment. More importantly, the specific reactivity of orthoboric groups to diols in cell glycocalyx facilitated a rapid cross-membrane translocation of drug nanocrystals, leading to efficient intracellular drug delivery, especially on cancer cells with highly expressed sialic acids. Boric acid coated nanocrystals of camptothecin, an anticancer drug with poor aqueous solubility and stability, demonstrated extreme cytotoxic activity (IC50 boric acid will have wide biomedical applications especially in biomaterials and drug delivery field.

  15. Self-assembly of phospholipid-PEG coating on nanoparticles through dual solvent exchange

    OpenAIRE

    Tong, Sheng; Hou, Sijian; Ren, Binbin; Zheng, Zhilan; Bao, Gang

    2011-01-01

    We coated nanoparticles including iron oxide nanoparticles and quantum dots with phospholipid-PEG using the newly developed dual solvent exchange method and demonstrated that, compared with the conventional film hydration method, the coating efficiency and quality of coated nanoparticles can be significantly improved. A better control of surface coating density and the amount of reactive groups on nanoparticle surface is achieved, allowing conjugation of different moieties with desirable surf...

  16. Fabrication of durable fluorine-free superhydrophobic polyethersulfone (PES) composite coating enhanced by assembled MMT-SiO2 nanoparticles

    Science.gov (United States)

    Zhang, Xiguang; Wang, Huaiyuan; Liu, Zhanjian; Zhu, Yixing; Wu, Shiqi; Wang, Chijia; Zhu, Yanji

    2017-02-01

    A durable fluorine-free polyethersulfone (PES) superhydrophobic composite coating with excellent wear-resistant and anti-corrosion properties has been successfully fabricated by combining sol-gel and spray technology. The robust micro/nano-structures of the prepared surface were established by introducing binary montmorillonite-silica (MMT-SiO2) assembled composite particles, which were formed by in-situ growth of SiO2 on MMT surfaces via sol-gel. Combined with the low surface energy of amino silicon oil (APDMS), the fluorine-free superhydrophoic PES coating was obtained with high water contact angle 156.1 ± 1.1° and low sliding angle 4.8 ± 0.7°. The anti-wear of the final PES/APDMS/MMT-SiO2 superhydrophobic coating can reach up to 60,100 cycles, which is outdistancing the pure PES coating (6800 cycles) and the PES/MMT/SiO2 coating prepared by simple physical mixture (18,200 cycles). The enhanced wear resistance property can be mainly attributed to the lubrication performance of APDMS and stable interface bonding force between the MMT surface and SiO2. Simultaneously, potentiodynamic polarization curves and electrochemical impedance spectroscopy exhibited the outstanding anti-corrosion property of PES/APDMS/MMT-SiO2 composite coating, with low corrosion current (1.6 × 10-10 A/cm2) and high protection efficiency (99.999%) even after 30 d immersion process. These test results show that this durable superhydrophobic PES composite coating can be hopefully to provide the possibility of industrial application.

  17. Investigation and optimization of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} grain boundaries and coated conductors; Untersuchung und Optimierung von YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}-Korngrenzen und Bandsupraleitern

    Energy Technology Data Exchange (ETDEWEB)

    Held, Rainer Robert Martin

    2010-01-29

    With increasing misorientation angle grain boundaries strongly reduce the critical current density of high temperature superconductors. For this reason costly techniques are used in production of modern Coated Conductors to induce sharp textures in the polycrystalline superconductor layers. In this dissertation measurements of the critical current density of different grain boundary types are presented showing that out-of-plane grain boundaries exhibit, also in applied magnetic fields, much higher critical current densities than expected. In further analysis of the grain boundaries indications for a microstructural reason of the high critical current densities were found. The high critical current densities of the out-of-plane grain boundaries should in fabrication of Coated Conductors allow for a relaxation of the out-of-plane grain alignment requirements and a concomitant cost reduction. In this work also results of a industrial cooperation with Nexans are presented demonstrating that the critical current density of metal-organic deposited grain boundaries and Coated Conductor layers can be increased by selective Calcium-doping. In the experiments selective Calcium-doping most effectively increased the critical current density of weak spots. (orig.)

  18. {l_brace}1 1 0{r_brace}<1 1 0> textured Ag tapes for biaxially oriented YBa{sub 2}Cu{sub 3}O{sub 7} coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Doi, T.; Inoue, K.; Hakuraku, Y.; Onabe, K.; Okada, M.; Kashima, N.; Nagaya, S

    2003-10-15

    Textured Ag tape is one of the most ideal substrates for the next generation high-T{sub c} wires operable in liquid nitrogen. {l_brace}1 1 0{r_brace}<1 1 0> textured Ag tapes were obtained by cold rolling and subsequent heat treatments. The texture of the tape after cold rolling (before annealing) was typical 'brass type'. For obtaining the {l_brace}1 1 0{r_brace}<1 1 0> texture, oxygen should exist in the Ag tape during the heat treatment. We find a two-step annealing is very effective to achieve the better {l_brace}1 1 0{r_brace}<1 1 0> textured Ag tape, compared with the samples annealed in one-step; the better grain alignment and the smoother surface could be obtained. Moreover, 300 deg. C annealing in O{sub 2} atmosphere allow us to obtain the {l_brace}1 1 0{r_brace}<1 1 0> texture by only 3 min final heat treatment at around 800 deg. C. This is beneficial to achieve the higher production speed of YBa{sub 2}Cu{sub 3}O{sub 7} coated conductors.

  19. Surfactant-free carnauba wax dispersion and its use for layer-by-layer assembled protective surface coatings on wood

    Energy Technology Data Exchange (ETDEWEB)

    Lozhechnikova, Alina [Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, FI-00076, Aalto (Finland); Bellanger, Hervé; Michen, Benjamin; Burgert, Ingo [Institute for Building Materials (IfB), Wood Materials Science, ETH Zürich, Stefano-Franscini-Platz 3, 8093 Zürich (Switzerland); Applied Wood Materials Laboratory, Empa − Swiss Federal Laboratories for Material Testing and Research, 8600 Dübendorf (Switzerland); Österberg, Monika, E-mail: monika.osterberg@aalto.fi [Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, FI-00076, Aalto (Finland)

    2017-02-28

    Highlights: • A facile sonication route to produce aqueous wax dispersions is developed. • The wax dispersion is naturally stable and free of surfactants or stabilizers. • Wax and ZnO particles are coated onto wood using layer-by-layer assembly. • The coating brings superhydrophobicity while preserving moisture buffering. • ZnO improves the color stability of wood to UV light. - Abstract: Protection from liquid water and UV radiation are equally important, and a sophisticated approach is needed when developing surface coatings that preserve the natural and well-appreciated aesthetic appearance of wood. In order to prevent degradation and prolong the service life of timber, a protective coating was assembled using carnauba wax particles and zinc oxide nanoparticles via layer-by-layer deposition in water. For this purpose, a facile sonication route was developed to produce aqueous wax dispersion without any surfactants or stabilizers. The suspension was stable above pH 4 due to the electrostatic repulsion between the negatively charged wax particles. The particle size could be controlled by the initial wax concentration with average particle sizes ranging from 260 to 360 nm for 1 and 10 g/L, respectively. The deposition of wax particles onto the surface of spruce wood introduced additional roughness to the wood surface at micron level, while zinc oxide provided nano roughness and UV-absorbing properties. In addition to making wood superhydrophobic, this novel multilayer coating enhanced the natural moisture buffering capability of spruce. Moreover, wood surfaces prepared in this fashion showed a significant reduction in color change after exposure to UV light. A degradation of the wax through photocatalytic activity of the ZnO particles was measured by FTIR, indicating that further studies are required to achieve long-term stability. Nevertheless, the developed coating showed a unique combination of superhydrophobicity and excellent moisture buffering

  20. Universal Coating from Electrostatic Self-Assembly to Prevent Multidrug-Resistant Bacterial Colonization on Medical Devices and Solid Surfaces.

    Science.gov (United States)

    Zheng, Wenshu; Jia, Yuexiao; Chen, Wenwen; Wang, Guanlin; Guo, Xuefeng; Jiang, Xingyu

    2017-06-28

    We provide a facile and scalable strategy for preparing gold nanoparticles (AuNPs)-based antibacterial coating on a variety of surfaces through electrostatic self-assembly. AuNPs conjugated with 4,6-diamino-2-pyrimidinethiol (DAPT, not antibacterial by itself), AuDAPT, can form stable coating on different substrates made from polyethylene (PS), polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polydimethylsiloxane (PDMS), and SiO 2 in one step. Such a coating can efficiently eradicate pathogenic Gram-negative bacteria and even multidrug-resistant (MDR) mutants without causing any side-effect such as cytotoxicity, hemolysis, coagulation, and inflammation. We show that immobilized AuDAPT, instead of AuDAPT released from the substrate, is responsible for killing the bacteria and that the antimicrobial components do not enter into the environment to cause secondary contamination to breed drug resistance. Advantages for such coating include applicability on a broad range of surfaces, low cost, stability, high antibacterial efficiency, good biocompatibility, and low risk in antibiotics pollution; these advantages may be particularly helpful in preventing infections that involve medical devices.

  1. Role of the AP2 beta-appendage hub in recruiting partners for clathrin-coated vesicle assembly.

    Directory of Open Access Journals (Sweden)

    Eva M Schmid

    2006-09-01

    Full Text Available Adaptor protein complex 2 alpha and beta-appendage domains act as hubs for the assembly of accessory protein networks involved in clathrin-coated vesicle formation. We identify a large repertoire of beta-appendage interactors by mass spectrometry. These interact with two distinct ligand interaction sites on the beta-appendage (the "top" and "side" sites that bind motifs distinct from those previously identified on the alpha-appendage. We solved the structure of the beta-appendage with a peptide from the accessory protein Eps15 bound to the side site and with a peptide from the accessory cargo adaptor beta-arrestin bound to the top site. We show that accessory proteins can bind simultaneously to multiple appendages, allowing these to cooperate in enhancing ligand avidities that appear to be irreversible in vitro. We now propose that clathrin, which interacts with the beta-appendage, achieves ligand displacement in vivo by self-polymerisation as the coated pit matures. This changes the interaction environment from liquid-phase, affinity-driven interactions, to interactions driven by solid-phase stability ("matricity". Accessory proteins that interact solely with the appendages are thereby displaced to areas of the coated pit where clathrin has not yet polymerised. However, proteins such as beta-arrestin (non-visual arrestin and autosomal recessive hypercholesterolemia protein, which have direct clathrin interactions, will remain in the coated pits with their interacting receptors.

  2. Robust Nanoparticle-DNA Conjugates Based on Mussel-Inspired Polydopamine Coating for Cell Imaging and Tailored Self-Assembly.

    Science.gov (United States)

    Wang, Chenxu; Zhou, Jiajing; Wang, Peng; He, Wenshan; Duan, Hongwei

    2016-03-16

    We have demonstrated that mussel-inspired polydopamine can serve as an intermediate coating layer for covalently attaching oligonucleotides on nanostructures of diverse chemical nature, which are made possible by the universal adhesion and spontaneous reactivity of polydopamine. Our results have shown that polydopamine can strongly bond to representative nanoparticles (i.e., Au nanoparticles and magnetic polymer nanobeads) and form a thin layer of coating that allows for attachment of commercially available DNA with thiol or amine end functionality. The resulting DNA-nanoparticle conjugates not only show excellent chemical and thermal stability and high loading density of DNA, but the linked DNA also maintain their biological functions in directing cancer cell targeting and undergo DNA hybridization to form multifunctional magnetic core-plasmonic satellite assemblies. The generally applicable strategy opens new opportunities for easy adoption of DNA-nanoparticle conjugates for broad applications in biosensors and nanomedicine.

  3. Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules.

    Science.gov (United States)

    Deng, Jie; Liu, Xinyue; Ma, Lang; Cheng, Chong; Shi, Wenbin; Nie, Chuanxiong; Zhao, Changsheng

    2014-12-10

    In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating

  4. Large-area fluidic assembly of single-walled carbon nanotubes through dip-coating and directional evaporation

    Science.gov (United States)

    Kim, Pilnam; Kang, Tae June

    2017-12-01

    We present a simple and scalable fluidic-assembly approach, in which bundles of single-walled carbon nanotubes (SWCNTs) are selectively aligned and deposited by directionally controlled dip-coating and solvent evaporation processes. The patterned surface with alternating regions of hydrophobic polydimethyl siloxane (PDMS) (height 100 nm) strips and hydrophilic SiO2 substrate was withdrawn vertically at a constant speed ( 3 mm/min) from a solution bath containing SWCNTs ( 0.1 mg/ml), allowing for directional evaporation and subsequent selective deposition of nanotube bundles along the edges of horizontally aligned PDMS strips. In addition, the fluidic assembly was applied to fabricate a field effect transistor (FET) with highly oriented SWCNTs, which demonstrate significantly higher current density as well as high turn-off ratio (T/O ratio 100) as compared to that with randomly distributed carbon nanotube bundles (T/O ratio <10).

  5. Antifouling and Antibacterial Multifunctional Polyzwitterion/Enzyme Coating on Silicone Catheter Material Prepared by Electrostatic Layer-by-Layer Assembly.

    Science.gov (United States)

    Vaterrodt, Anne; Thallinger, Barbara; Daumann, Kevin; Koch, Dereck; Guebitz, Georg M; Ulbricht, Mathias

    2016-02-09

    The formation of bacterial biofilms on indwelling medical devices generally causes high risks for adverse complications such as catheter-associated urinary tract infections. In this work, a strategy for synthesizing innovative coatings of poly(dimethylsiloxane) (PDMS) catheter material, using layer-by-layer assembly with three novel functional polymeric building blocks, is reported, i.e., an antifouling copolymer with zwitterionic and quaternary ammonium side groups, a contact biocidal derivative of that polymer with octyl groups, and the antibacterial hydrogen peroxide (H2O2) producing enzyme cellobiose dehydrogenase (CDH). CDH oxidizes oligosaccharides by transferring electrons to oxygen, resulting in the production of H2O2. The design and synthesis of random copolymers which combine segments that have antifouling properties by zwitterionic groups and can be used for electrostatically driven layer-by-layer (LbL) assembly at the same time were based on the atom-transfer radical polymerization of dimethylaminoethyl methacrylate and subsequent partial sulfobetainization with 1,3-propane sultone followed by quaternization with methyl iodide only or octyl bromide and thereafter methyl iodide. The alternating multilayer systems were formed by consecutive adsorption of the novel polycations with up to 50% zwitterionic groups and of poly(styrenesulfonate) as the polyanion. Due to its negative charge, enzyme CDH was also firmly embedded as a polyanionic layer in the multilayer system. This LbL coating procedure was first performed on prefunctionalized silicon wafers and studied in detail with ellipsometry as well as contact angle (CA) and zetapotential (ZP) measurements before it was transferred to prefunctionalized PDMS and analyzed by CA and ZP measurements as well as atomic force microscopy. The coatings comprising six layers were stable and yielded a more neutral and hydrophilic surface than did PDMS, the polycation with 50% zwitterionic groups having the largest

  6. Molecular Simulations of Gold Nanoparticles Coated With Self-Assembled Alkanethiolate Monolayers

    National Research Council Canada - National Science Library

    Henz, Brian J; Fischer, James W; Zachariah, Michael R

    2006-01-01

    In order to utilize the novel electrical, magnetic, optical, and physical properties of coated metal nanoparticles, one must be able to efficiently predict the nanoparticle size-dependent properties...

  7. Surfactant-free carnauba wax dispersion and its use for layer-by-layer assembled protective surface coatings on wood

    Science.gov (United States)

    Lozhechnikova, Alina; Bellanger, Hervé; Michen, Benjamin; Burgert, Ingo; Österberg, Monika

    2017-02-01

    Protection from liquid water and UV radiation are equally important, and a sophisticated approach is needed when developing surface coatings that preserve the natural and well-appreciated aesthetic appearance of wood. In order to prevent degradation and prolong the service life of timber, a protective coating was assembled using carnauba wax particles and zinc oxide nanoparticles via layer-by-layer deposition in water. For this purpose, a facile sonication route was developed to produce aqueous wax dispersion without any surfactants or stabilizers. The suspension was stable above pH 4 due to the electrostatic repulsion between the negatively charged wax particles. The particle size could be controlled by the initial wax concentration with average particle sizes ranging from 260 to 360 nm for 1 and 10 g/L, respectively. The deposition of wax particles onto the surface of spruce wood introduced additional roughness to the wood surface at micron level, while zinc oxide provided nano roughness and UV-absorbing properties. In addition to making wood superhydrophobic, this novel multilayer coating enhanced the natural moisture buffering capability of spruce. Moreover, wood surfaces prepared in this fashion showed a significant reduction in color change after exposure to UV light. A degradation of the wax through photocatalytic activity of the ZnO particles was measured by FTIR, indicating that further studies are required to achieve long-term stability. Nevertheless, the developed coating showed a unique combination of superhydrophobicity and excellent moisture buffering ability and some UV protection, all achieved using an environmentally friendly coating process, which is beneficial to retain the natural appearance of wood and improve indoor air quality and comfort.

  8. Plasma Generator Using Spiral Conductors

    Science.gov (United States)

    Szatkowski, George N. (Inventor); Dudley, Kenneth L. (Inventor); Ticatch, Larry A. (Inventor); Smith, Laura J. (Inventor); Koppen, Sandra V. (Inventor); Nguyen, Truong X. (Inventor); Ely, Jay J. (Inventor)

    2016-01-01

    A plasma generator includes a pair of identical spiraled electrical conductors separated by dielectric material. Both spiraled conductors have inductance and capacitance wherein, in the presence of a time-varying electromagnetic field, the spiraled conductors resonate to generate a harmonic electromagnetic field response. The spiraled conductors lie in parallel planes and partially overlap one another in a direction perpendicular to the parallel planes. The geometric centers of the spiraled conductors define endpoints of a line that is non-perpendicular with respect to the parallel planes. A voltage source coupled across the spiraled conductors applies a voltage sufficient to generate a plasma in at least a portion of the dielectric material.

  9. Decoupling and tuning competing effects of different types of defects on flux creep in irradiated YBa2Cu3O7-δ coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Eley, S.; Leroux, M.; Rupich, M. W.; Miller, D. J.; Sheng, H.; Niraula, P. M.; Kayani, A.; Welp, U.; Kwok, W. -K.; Civale, L.

    2016-11-15

    YBa2Cu3O7-δ coated conductors (CCs) have achieved high critical current densities (J c) that can be further increased through the introduction of additional defects using particle irradiation. However, these gains are accompanied by increases in the flux creep rate, a manifestation of competition between the different types of defects. Here, we study this competition to better understand how to design pinning landscapes that simultaneously increase J c and reduce creep. CCs grown by metal organic deposition show non-monotonic changes in the temperature-dependent creep rate, S(T). Notably, in low fields, there is a conspicuous dip to low S as the temperature (T) increases from ~20 to ~65 K. Oxygen-, proton-, and Au-irradiation substantially increase S in this temperature range. Focusing on an oxygen-irradiated CC, we investigate the contribution of different types of irradiation-induced defects to the flux creep rate. Specifically, we study S(T) as we tune the relative density of point defects to larger defects by annealing both an as-grown and an irradiated CC in O2 at temperatures T A = 250 °C–600 °C. We observe a steady decrease in S(T > 20 K) with increasing T A, unveiling the role of pre-existing nanoparticle precipitates in creating the dip in S(T) and point defects and clusters in increasing S at intermediate temperatures.

  10. Transport Jc Measurements of HTS Conductors under High Magnetic Field at LNCMI

    Science.gov (United States)

    Chaud, Xavier; Debray, François; Mossang, Eric; Tixador, Pascal; Rey, Jean-Michel; Lecrevisse, Thibault; Bruzek, Christian-Eric

    The LNCMI, the national French high magnetic field facility, provides high fields generated mainly by resistive magnets. Because of the forecast increasing price of electricity, LNCMI has a strong incentive to participate to the development and characterizations of HTS conductors in view of their use for the generation of strong field. Latest YBCO coated conductors have improved properties showing a great potential with that respect, without excluding Bi2212 and MgB2 for particular cases. We present the existing set-up to measure short straight or VAMAS type coil samples at variable temperature and high field up to 30 T, and some measurements obtained on different HTS conductors, Bi2212 round wires and YBCO coated conductors. We also report on the first results obtained at 18 T with a pancake coil made of commercial YBCO coated conductor tapes on a newly developed solenoid test bench.

  11. Reversible Self-Assembly of Glutathione-Coated Gold Nanoparticle Clusters via pH-Tunable Interactions.

    Science.gov (United States)

    Moaseri, Ehsan; Bollinger, Jonathan A; Changalvaie, Behzad; Johnson, Lindsay; Schroer, Joseph; Johnston, Keith P; Truskett, Thomas M

    2017-10-31

    Nanoparticle (NP) clusters with diameters ranging from 20 to 100 nm are reversibly assembled from 5 nm gold (Au) primary particles coated with glutathione (GSH) in aqueous solution as a function of pH in the range of 5.4 to 3.8. As the pH is lowered, the GSH surface ligands become partially zwitterionic and form interparticle hydrogen bonds that drive the self-limited assembly of metastable clusters in clusters up to 20 nm in size are stable against cluster-cluster aggregation for up to 1 day, clusters up to 80 nm in size can be stabilized over this period via the addition of citrate to the solution in equal molarity with GSH molecules. The cluster diameter may be cycled reversibly by tuning pH to manipulate the colloidal interactions; however, modest background cluster-cluster aggregation occurs during cycling. Cluster sizes can be stabilized for at least 1 month via the addition of PEG-thiol as a grafted steric stabilizer, where PEG-grafted clusters dissociate back to starting primary NPs at pH 7 in fewer than 3 days. Whereas the presence of excess citrate has little effect on the initial size of the metastable clusters, it is necessary for both the cycling and dissociation to mediate the GSH-GSH hydrogen bonds. In summary, these metastable clusters exhibit significant characteristics of equilibrium self-limited assembly between primary particles and clusters on time scales where cluster-cluster aggregation is not present.

  12. Focus on Organic Conductors

    Directory of Open Access Journals (Sweden)

    Shinya Uji, Takehiko Mori and Toshihiro Takahashi

    2009-01-01

    Full Text Available Organic materials are usually thought of as electrical insulators. Progress in chemical synthesis, however, has brought us a rich variety of conducting organic materials, which can be classified into conducting polymers and molecular crystals. Researchers can realize highly conducting molecular crystals in charge-transfer complexes, where suitable combinations of organic electron donor or acceptor molecules with counter ions or other organic molecules provide charge carriers. By means of a kind of chemical doping, the charge-transfer complexes exhibit high electrical conductivity and, thanks to their highly crystalline nature, even superconductivity has been observed. This focus issue of Science and Technology of Advanced Materials is devoted to the research into such 'organic conductors'The first organic metal was (TTF(TCNQ, which was found in 1973 to have high conductivity at room temperature and a metal–insulator transition at low temperatures. The first organic superconductor was (TMTSF2PF6, whose superconductivity under high pressures was reported by J´erome in 1980. After these findings, the research on organic conductors exploded. Hundreds of organic conductors have been reported, among which more than one hundred exhibit superconductivity. Recently, a single-component organic conductor has been found with metallic conductivity down to low temperatures.In these organic conductors, in spite of their simple electronic structures, much new physics has arisen from the low dimensionality. Examples are charge and spin density waves, characteristic metal–insulator transitions, charge order, unconventional superconductivity, superconductor–insulator transitions, and zero-gap conductors with Dirac cones. The discovery of this new physics is undoubtedly derived from the development of many intriguing novel organic conductors. High quality single crystals are indispensable to the precise measurement of electronic states.This focus issue

  13. Preparation of the antithrombotic and antimicrobial coating through layer-by-layer self-assembly of nattokinase-nanosilver complex and polyethylenimine.

    Science.gov (United States)

    Wei, Xuetuan; Luo, Mingfang; Liu, Huizhou

    2014-04-01

    The bifunctional coating with antithrombotic and antimicrobial activity was developed using nattokinase (NK) and nanosilver (AgNPs). Firstly, the adsorption interactions between NK and AgNPs were confirmed, and the composite particles of NK-AgNPs were prepared by adsorption of NK with AgNPs. At 5FU/mL of NK concentration, the saturation adsorption capacity reached 24.35 FU/mg AgNPs with a high activity recovery of 97%, and adsorption by AgNPs also enhanced the heat stability and anticoagulant effect of NK. Based on the electrostatic force driven layer-by-layer self-assembly, the NK-AgNPs were further assembled with polyethylenimine (PEI) to form coating. UV-vis analysis showed that the self-assembly process was regular, and atom force microscopy analysis indicated that NK-AgNPs were uniformly embedded into the coating. The NK-AgNPs-PEI composite coating showed potent antithrombotic activity and antibacterial activity. This study developed a novel strategy to construct the bifunctional coating with antithrombotic and antimicrobial properties, and the coating material showed promising potential to be applied in the medical device. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Challenges and status of ITER conductor production

    Science.gov (United States)

    Devred, A.; Backbier, I.; Bessette, D.; Bevillard, G.; Gardner, M.; Jong, C.; Lillaz, F.; Mitchell, N.; Romano, G.; Vostner, A.

    2014-04-01

    Taking the relay of the large Hadron collider (LHC) at CERN, ITER has become the largest project in applied superconductivity. In addition to its technical complexity, ITER is also a management challenge as it relies on an unprecedented collaboration of seven partners, representing more than half of the world population, who provide 90% of the components as in-kind contributions. The ITER magnet system is one of the most sophisticated superconducting magnet systems ever designed, with an enormous stored energy of 51 GJ. It involves six of the ITER partners. The coils are wound from cable-in-conduit conductors (CICCs) made up of superconducting and copper strands assembled into a multistage cable, inserted into a conduit of butt-welded austenitic steel tubes. The conductors for the toroidal field (TF) and central solenoid (CS) coils require about 600 t of Nb3Sn strands while the poloidal field (PF) and correction coil (CC) and busbar conductors need around 275 t of Nb-Ti strands. The required amount of Nb3Sn strands far exceeds pre-existing industrial capacity and has called for a significant worldwide production scale up. The TF conductors are the first ITER components to be mass produced and are more than 50% complete. During its life time, the CS coil will have to sustain several tens of thousands of electromagnetic (EM) cycles to high current and field conditions, way beyond anything a large Nb3Sn coil has ever experienced. Following a comprehensive R&D program, a technical solution has been found for the CS conductor, which ensures stable performance versus EM and thermal cycling. Productions of PF, CC and busbar conductors are also underway. After an introduction to the ITER project and magnet system, we describe the ITER conductor procurements and the quality assurance/quality control programs that have been implemented to ensure production uniformity across numerous suppliers. Then, we provide examples of technical challenges that have been encountered and

  15. Correlation of Effective Dispersive and Polar Surface Energies in Heterogeneous Self-Assembled Monolayer Coatings

    DEFF Research Database (Denmark)

    Zhuang, Yanxin; Hansen, Ole

    2009-01-01

    grown oil oxidized (100) silicon Surfaces in a vapor phase process using five different precursors. Experimentally, effective surface energy components of the fluorocarbon self-assembled monolayers were determined from measured contact angles using the Owens-Wendt-Rabel-Kaelble method. We show...

  16. Molecular Dynamics Study of Alkanethiolate Self-Assembled Monolayer Coated Gold Nanoparticle

    Science.gov (United States)

    2007-06-01

    of Organosulfur Compounds on Au( 111). Implications for Molecular Self-Assembly on Gold 21. Plimpton, S.J., "Fast Parallel Algorithms for Short-Range... Organosulfur Compounds SHAKE Algorithm for Molecular Dynamics." Journal of Adsorbed on Gold Single Crystals: Electron Diffraction Computational Physics, 52

  17. Anticorrosion Coatings Based on Assemblies of Superhydrophobic Particles Impregnated with Conductive Oil

    Science.gov (United States)

    2016-05-13

    Amorphous silica nanoparticles were synthesized using sol-gel techniques. The particles were fluorinated to impart them with superhydrophobic properties...coatings based on fluorinated diatomaceous earth: Abrasion resistance versus particle geometry’’ Appl. Surf. Sci. 292, 563–569 (2014). 8. Vlassiouk I...layer graphene by shear exfoliation in liquids” Nature Materials 13, 624-630 (2014). 11. Thermo Scientific Application Note AN52252 “The Raman

  18. Solvent-like ligand-coated ultrasmall cadmium selenide nanocrystals: strong electronic coupling in a self-organized assembly

    Science.gov (United States)

    Lawrence, Katie N.; Johnson, Merrell A.; Dolai, Sukanta; Kumbhar, Amar; Sardar, Rajesh

    2015-07-01

    Strong inter-nanocrystal electronic coupling is a prerequisite for delocalization of exciton wave functions and high conductivity. We report 170 meV electronic coupling energy of short chain poly(ethylene glycol) thiolate-coated ultrasmall (Cryo-transmission electron microscopy analysis showed the formation of a pearl-necklace assembly of nanocrystals in solution with regular inter-nanocrystal spacing. The electronic coupling was studied as a function of CdSe nanocrystal size where the smallest nanocrystals exhibited the largest coupling energy. The electronic coupling in spin-cast thin-film (electronic coupling of SNCs in a self-organized film could facilitate the large-scale production of highly efficient electronic materials for advanced optoelectronic device application.Strong inter-nanocrystal electronic coupling is a prerequisite for delocalization of exciton wave functions and high conductivity. We report 170 meV electronic coupling energy of short chain poly(ethylene glycol) thiolate-coated ultrasmall (Cryo-transmission electron microscopy analysis showed the formation of a pearl-necklace assembly of nanocrystals in solution with regular inter-nanocrystal spacing. The electronic coupling was studied as a function of CdSe nanocrystal size where the smallest nanocrystals exhibited the largest coupling energy. The electronic coupling in spin-cast thin-film (electronic coupling of SNCs in a self-organized film could facilitate the large-scale production of highly efficient electronic materials for advanced optoelectronic device application. Electronic supplementary information (ESI) available: Additional experimental procedure, UV-vis absorption, EDS, and NMR spectra and cryo-TEM image. See DOI: 10.1039/c5nr02038g

  19. Constructing of DNA vectors with controlled nanosize and single dispersion by block copolymer coating gold nanoparticles as template assembly

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junbo, E-mail: Lijunbo@haust.edu.cn [Henan University of Science and Technology, School of Chemical Engineering and Pharmaceutics (China); Wu, Wenlan [Henan University of Science and Technology, School of Medicine (China); Gao, Jiayu; Liang, Ju; Zhou, Huiyun; Liang, Lijuan [Henan University of Science and Technology, School of Chemical Engineering and Pharmaceutics (China)

    2017-03-15

    Synthesized vectors with nanoscale size and stable colloid dispersion are highly desirable for improving gene delivery efficiency. Here, a core-shell template particle was constructed with polyethylene glycol-b-poly1-(3-aminopropyl)-3-(2-methacryloyloxy propylimidazolium bromine) (PEG-b-PAMPImB) coating gold nanoparticles (PEG-b-PAMPImB-@-Au NPs) for loading DNA and delivering in vitro. Data from transmission electron microscopy (TEM) and dynamic light scattering (DLS) suggest that these nanoplexes, by forming an electrostatic complex with DNA at the inner PAMPImB shell, offer steric protection for the outer PEG corona leading to single dispersion and small size. Notably, higher colloid stability and lower cytotoxicity were achieved with these nanoplexes when compared with PAMPImB monolayer-coated gold nanoparticles (Au NPs). Confocal laser scanning microscopy and intracellular trafficking TEM further indicate that the nanoplexes can translocate across the cell membrane and partly enter the nucleus for high efficient expression. Thus, template assembly represents a promising approach to control the size and colloid stability of gene vectors and ensure safety and efficiency of DNA delivery.

  20. Constructing of DNA vectors with controlled nanosize and single dispersion by block copolymer coating gold nanoparticles as template assembly

    Science.gov (United States)

    Li, Junbo; Wu, Wenlan; Gao, Jiayu; Liang, Ju; Zhou, Huiyun; Liang, Lijuan

    2017-03-01

    Synthesized vectors with nanoscale size and stable colloid dispersion are highly desirable for improving gene delivery efficiency. Here, a core-shell template particle was constructed with polyethylene glycol- b-poly1-(3-aminopropyl)-3-(2-methacryloyloxy propylimidazolium bromine) (PEG- b-PAMPImB) coating gold nanoparticles (PEG- b-PAMPImB-@-Au NPs) for loading DNA and delivering in vitro. Data from transmission electron microscopy (TEM) and dynamic light scattering (DLS) suggest that these nanoplexes, by forming an electrostatic complex with DNA at the inner PAMPImB shell, offer steric protection for the outer PEG corona leading to single dispersion and small size. Notably, higher colloid stability and lower cytotoxicity were achieved with these nanoplexes when compared with PAMPImB monolayer-coated gold nanoparticles (Au NPs). Confocal laser scanning microscopy and intracellular trafficking TEM further indicate that the nanoplexes can translocate across the cell membrane and partly enter the nucleus for high efficient expression. Thus, template assembly represents a promising approach to control the size and colloid stability of gene vectors and ensure safety and efficiency of DNA delivery.

  1. International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Operation, Recovery, and Lessons Learned

    Science.gov (United States)

    Balistreri, Steven F.; Steele, John W.; Caron, Mark E.; Laliberte, Yvon J.; Shaw, Laura A.

    2013-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX in the ISS segments, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the ISS cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings as well as remediation and recovery of the full heat exchanger will be

  2. Development of dielectric window to conductor assembly

    Energy Technology Data Exchange (ETDEWEB)

    Heikinheimo, L.; Nuutinen, S.; Taehtinen, S. [VTT Manufacturing Technology, Espoo (Finland). Materials and Structural Integrity

    1998-12-31

    The report summarises the work done by Association Euratom-Tekes in developing manufacturing procedures for vacuum tight ceramic to metal joints and in manufacturing full scale components for the ICRF vacuum window construction. The development started at VTT Manufacturing Technology in 1996 under the Task T238.2 and continued in 1997 under the Underlying Technology tasks. In the design of the components, the following issues were addressed and resolved: (1) The choice of dielectric material; The choice is made as the best compromise among nuclear, mechanical, and thermal properties, but in due consideration of material availability, fabrication issues and response to cyclic loads, (2) Layout and detailed design. The shape of the dielectric window is optimized to minimize electric fields in the dielectric materials; The optimised field distribution is computed in a 2D geometry; The design includes thermal calculation and the cooling layout and includes provision for remote handling replacement in one block, (3) Metal/dielectric joining. The joining technology is selected and justified. Joining tests on material selections to verify the applicability has been done, the validation of the design pre-prototype tests have been carried out selectively. The steps for the manufacture of these full scale components are described in the report with the appropriate concluding remarks and suggestions for the further actions. (orig.)

  3. Mitotic spindle assembly around RCC1-coated beads in Xenopus egg extracts.

    Directory of Open Access Journals (Sweden)

    David Halpin

    2011-12-01

    Full Text Available During cell division the genetic material on chromosomes is distributed to daughter cells by a dynamic microtubule structure called the mitotic spindle. Here we establish a reconstitution system to assess the contribution of individual chromosome proteins to mitotic spindle formation around single 10 µm diameter porous glass beads in Xenopus egg extracts. We find that Regulator of Chromosome Condensation 1 (RCC1, the Guanine Nucleotide Exchange Factor (GEF for the small GTPase Ran, can induce bipolar spindle formation. Remarkably, RCC1 beads oscillate within spindles from pole to pole, a behavior that could be converted to a more typical, stable association by the addition of a kinesin together with RCC1. These results identify two activities sufficient to mimic chromatin-mediated spindle assembly, and establish a foundation for future experiments to reconstitute spindle assembly entirely from purified components.

  4. Contamination profile of Printed Circuit Board Assemblies in relation to soldering types and conformal coating

    OpenAIRE

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition, and concentration are profiled and reported. Presence of localized flux residues were visualized using a commercial Residue RAT gel test and chemical structure was identified by FT-IR, while the concentrat...

  5. Improved textured La{sub 2}Zr{sub 2}O{sub 7} buffer on La{sub 3}TaO{sub 7} seed for all-MOD Buffer/YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Parans Paranthaman, M. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States)], E-mail: paranthamanm@ornl.gov; Bhuiyan, M.S.; Sathyamurthy, S. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Heatherly, L.; Cantoni, C.; Goyal, A. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6116 (United States)

    2008-09-15

    The overall purpose of this research is to develop a potentially low-cost, high throughput, high yield, manufacturing process for buffer deposition, and to gain a fundamental understanding of buffer layers required for an all metal-organic deposition (MOD) based chemical solution approach. This understanding is critical to the development of a reliable, robust, low-cost, long-length manufacturing process of 2G wires. The standard RABiTS architectures consists of a starting template of biaxially textured Ni-W (5 at.%) substrate with a seed layer of Y{sub 2}O{sub 3}, a barrier layer of YSZ, and a CeO{sub 2} cap. In this three-layer architecture, all the buffers are deposited using reactive sputtering. We have recently demonstrated that the barrier properties and the performance of MOD La{sub 2}Zr{sub 2}O{sub 7} (LZO) match that of sputtered YSZ layers. In this work, the texture of MOD LZO was also improved by inserting a sputtered Y{sub 2}O{sub 3} seed layer on which LZO grows without any degradation of texture. Significant improvement in the texture of sputtered Y{sub 2}O{sub 3} seeds on NiW substrates is usually observed which is then transferred to the LZO layer. A key challenge for an all-solution approach is to replace the sputtered seed layer with a possible MOD seed layer with improved texture and on which no degradation of LZO texture occurs. Very recently, we have grown MOD La{sub 3}TaO{sub 7} (LTO) seeds directly on biaxially textured Ni-W (3 at.%) with improved texture. In this study, we report a systematic investigation of the growth MOD LZO barrier layer on MOD LTO seeds. Preliminary results show that it is possible to grow MOD LZO with improved texture on MOD LTO seeds. This approach could be potentially used for future all MOD buffer/YBCO coated conductors.

  6. Films of Carbon Nanomaterials for Transparent Conductors

    Science.gov (United States)

    Ho, Xinning; Wei, Jun

    2013-01-01

    The demand for transparent conductors is expected to grow rapidly as electronic devices, such as touch screens, displays, solid state lighting and photovoltaics become ubiquitous in our lives. Doped metal oxides, especially indium tin oxide, are the commonly used materials for transparent conductors. As there are some drawbacks to this class of materials, exploration of alternative materials has been conducted. There is an interest in films of carbon nanomaterials such as, carbon nanotubes and graphene as they exhibit outstanding properties. This article reviews the synthesis and assembly of these films and their post-treatment. These processes determine the film performance and understanding of this platform will be useful for future work to improve the film performance. PMID:28809267

  7. Films of Carbon Nanomaterials for Transparent Conductors

    Directory of Open Access Journals (Sweden)

    Jun Wei

    2013-05-01

    Full Text Available The demand for transparent conductors is expected to grow rapidly as electronic devices, such as touch screens, displays, solid state lighting and photovoltaics become ubiquitous in our lives. Doped metal oxides, especially indium tin oxide, are the commonly used materials for transparent conductors. As there are some drawbacks to this class of materials, exploration of alternative materials has been conducted. There is an interest in films of carbon nanomaterials such as, carbon nanotubes and graphene as they exhibit outstanding properties. This article reviews the synthesis and assembly of these films and their post-treatment. These processes determine the film performance and understanding of this platform will be useful for future work to improve the film performance.

  8. Physics of superionic conductors

    CERN Document Server

    1979-01-01

    Superionic conductors are solids whose ionic conductivities approach, and in some cases exceed, those of molten salts and electrolyte solutions. This implies an un­ usual state of matter in which some atoms have nearly liquidlike mobility while others retain their regular crystalline arrangement. This liquid-solid duality has much appeal to condensed matter physicists, and the coincident development of powerful new methods for studying disordered solids and interest in superionic conductors for technical applications has resulted in a new surge of activity in this venerable field. It is the purpose of this book to summarize the current re­ search in the physics of superionic conduction. with special emphasis on those aspects which set these materials apart from other solids. The volume is aimed to­ wards the materials community and will, we expect, stimulate further research on these potentially useful substances. The usual characterization of the superionic phase lists high ionic conductivity; low activat...

  9. Hierarchical host-guest assemblies formed on dodecaborate-coated gold nanoparticles.

    Science.gov (United States)

    Assaf, Khaleel I; Hennig, Andreas; Peng, Shu; Guo, Dong-Sheng; Gabel, Detlef; Nau, Werner M

    2017-04-20

    Undecahydro-mercapto-closo-dodecaborate (BSH), a purely inorganic cluster anion, serves as an unconventional stabilizing ligand for the preparation of gold nanoparticles (AuNPs). The BSH-capped AuNPs serve as nano-scaffolds, allowing for the creation of supramolecular architectures by using polycationic macrocyclic host molecules, through strong host-guest complexation. An amphiphilic calixarene (CX) forms first mono- and subsequently bi-layer assemblies on the BSH-AuNP surfaces depending on the CX concentration. The inorganic-organic hybrid materials, combined with host-dye displacement assays, serve as a chemosensing ensemble for negatively charged molecules, including DNA.

  10. The CMS conductor

    CERN Document Server

    Horváth, I L; Marti, H P; Neuenschwander, J; Smith, R P; Fabbricatore, P; Musenich, R; Calvo, A; Campi, D; Curé, B; Desirelli, Alberto; Favre, G; Riboni, P L; Sgobba, Stefano; Tardy, T; Sequeira-Lopes-Tavares, S

    2000-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments, which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN, the design field of the CMS magnet is 4 T, the magnetic length is 13 m and the aperture is 6 m. This high magnetic field is achieved by means of a 4 layer, 5 modules superconducting coil. The coil is wound from an Al-stabilized Rutherford type conductor. The nominal current of the magnet is 20 kA at 4.5 K. In the CMS coil the structural function is ensured, unlike in other existing Al-stabilized thin solenoids, both by the Al-alloy reinforced conductor and the external former. In this paper the retained manufacturing process of the 50-km long reinforced conductor is described. In general the Rutherford type cable is surrounded by high purity aluminium in a continuous co-extrusion process to produce the Insert. Thereafter the reinforcement is joined by Electron Beam Welding to the pure Al of the insert, before being machined to the final dimensions. During the...

  11. Stable Aqueous Suspension and Self-Assembly of Graphite Nanoplatelets Coated with Various Polyelectrolytes

    Directory of Open Access Journals (Sweden)

    Jue Lu

    2010-01-01

    Full Text Available Exfoliated graphite nanoplatelets (xGnPs with an average thickness of 1–10 nm present an inexpensive alternative to carbon nanotubes in many applications. In this paper, stable aqueous suspension of xGnP was achieved by noncovalent functionalization of xGnP with polyelectrolytes. The surfactants and polyelectrolytes were compared with respect to their ability to suspend graphite nanoplatelets. The surface charge of the nanoplatelets was characterized with zeta potential measurements, and the bonding strength of the polymer chains to the surface of xGnP was characterized with Raman spectroscopy. This robust method opens up the possibility of using this inexpensive nanomaterial in many applications, including electrochemical devices, and leads to simple processing techniques such as layer-by-layer deposition. Therefore, the formation of xGnP conductive coatings using layer-by-layer deposition was also demonstrated.

  12. Corrosion resistance and adhesion strength of a spin-assisted layer-by-layer assembled coating on AZ31 magnesium alloy

    Science.gov (United States)

    Zhao, Yan-Bin; Liu, Han-Peng; Li, Chang-Yang; Chen, Yong; Li, Shuo-Qi; Zeng, Rong-Chang; Wang, Zhen-Lin

    2018-03-01

    A polyvinylpyrrolidone (PVP)/polyacrylic acid (PAA) layer-by-layer (LbL) assembled composite coating with a multilayer structure for the corrosion protection of AZ31 magnesium alloy was prepared by a novel spin-casting method. The microstructure and composition of this coating were investigated by means of SEM, XRD and FT-IR measurements. Moreover, electrochemical, immersion and scratch tests in vitro were performed to measure the corrosion performance and the adhesion strength. These results indicated that the (PVP/PAA)10 composite coating with defect-free, dense and uniform morphologies could be successfully deposited on the surface of magnesium alloy. The coating had excellent corrosion resistance and adhesion strength.

  13. Synthesis and characterization of polystyrene coated iron oxide nanoparticles and asymmetric assemblies by phase inversion

    KAUST Repository

    Xie, Yihui

    2014-09-02

    Films with a gradient concentration of magnetic iron oxide nanoparticles are reported, based on a phase inversion membrane process. Nanoparticles with ∼13 nm diameter were prepared by coprecipitation in aqueous solution and stabilized by oleic acid. They were further functionalized by ATRP leading to grafted polystyrene brush. The final nanoparticles of 33 nm diameter were characterized by TGA, FTIR spectroscopy, GPC, transmission electron microscopy, and dynanmic light scattering. Asymmetric porous nanoparticle assemblies were then prepared by solution casting and immersion in water. The nanocomposite film production with functionalized nanoparticles is fast and technically scalable. The morphologies of films were characterized by scanning electron microscopy and atomic force microscopy, demonstrating the presence of sponge-like structures and finger-like cavities when 50 and 13 wt % casting solutions were, respectively, used. The magnetic properties were evaluated using vibrating sample magnetometer.

  14. Structured multilayered electrodes of proton/electron conducting polymer for polymer electrolyte membrane fuel cells assembled by spray coating

    Energy Technology Data Exchange (ETDEWEB)

    Wolz, Andre; Zils, Susanne; Roth, Christina [Institute for Materials Science, TU Darmstadt, Petersenstr. 23, D-64287 Darmstadt (Germany); Michel, Marc [Department of Advanced Materials and Structures, CRP Henri Tudor, 66 Rue de Luxembourg, L-4002 Esch-sur-Alzette (Luxembourg)

    2010-12-15

    Membrane electrode assemblies (MEAs) for fuel cell applications consist of electron conductive support materials, proton conductive ionomer, and precious metal nanoparticles to enhance the catalytic activity towards H{sub 2} oxidation and O{sub 2} reduction. An optimized connection of all three phases is required to obtain a high noble metal utilization, and accordingly a good performance. Using polyaniline (PANI) as an alternative support material, the generally used ionomer Nafion {sup registered} could be replaced in the catalyst layer. PANI has the advantage to be electron and proton conductive at the same time, and can be used as a catalyst support as well. In this study, a new technique building up alternating layers of PANI supported catalyst and single-walled carbon nanotubes (SWCNT) supported catalyst is introduced. Multilayers of PANI and SWCNT catalysts are used on the cathode side, whereas the anode side is composed of commercial platinum/carbon black catalyst and Nafion {sup registered}, applied by an airbrush. No additional Nafion {sup registered} ionomer is used for proton conductivity of the cathode. The so called spray coating method results in high power densities up to 160 mW cm{sup -2} with a Pt loading of 0.06 mg cm{sup -2} at the cathode, yielding a Pt utilization of 2663 mW mg{sub Pt}{sup -1}. As well as PANI, supports of SWCNTs have the advantage to have a fibrous structure and additional, they provide high electron conductivity. The combination of the new technique and the fibrous 1-dimensional support materials leads to a porous 3-dimensional electrode network which could enhance the gas transport through the electrode as well as the Pt utilization. The spray coating method could be upgraded to an in-line process and is not restricted to batch production. (author)

  15. Improvement of SOFC electrodes using mixed ionic-electronic conductors

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzaki, Y.; Hishinuma, M. [Tokyo Gas Co., Ltd. (Japan)

    1996-12-31

    Since the electrode reaction of SOFC is limited to the proximity of a triple phase boundary (TPB), the local current density at the electrode and electrolyte interface is larger than mean current density, which causes large ohmic and electrode polarization. This paper describes an application of mixed ionic-electronic conductors to reduce such polarization by means of (1) enhancing ionic conductivity of the electrolyte surface layer by coating a high ionic conductors, and (2) reducing the local current density by increasing the electrochemically active sites.

  16. Assembling nanoparticle coatings to improve the drug delivery performance of lipid based colloids

    Science.gov (United States)

    Simovic, Spomenka; Barnes, Timothy J.; Tan, Angel; Prestidge, Clive A.

    2012-02-01

    Lipid based colloids (e.g. emulsions and liposomes) are widely used as drug delivery systems, but often suffer from physical instabilities and non-ideal drug encapsulation and delivery performance. We review the application of engineered nanoparticle layers at the interface of lipid colloids to improve their performance as drug delivery systems. In addition we focus on the creation of novel hybrid nanomaterials from nanoparticle-lipid colloid assemblies and their drug delivery applications. Specifically, nanoparticle layers can be engineered to enhance the physical stability of submicron lipid emulsions and liposomes, satbilise encapsulated active ingredients against chemical degradation, control molecular transport and improve the dermal and oral delivery characteristics, i.e. increase absorption, bioavailability and facilitate targeted delivery. It is feasible that hybrid nanomaterials composed of nanoparticles and colloidal lipids are effective encapsulation and delivery systems for both poorly soluble drugs and biological drugs and may form the basis for the next generation of medicines. Additional pre-clinical research including specific animal model studies are required to advance the peptide/protein delivery systems, whereas the silica lipid hybrid systems have now entered human clinical trials for poorly soluble drugs.

  17. Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

    Directory of Open Access Journals (Sweden)

    Ognen Pop-Georgievski

    2015-03-01

    Full Text Available Composite materials based on a titanium support and a thin, alginate hydrogel could be used in bone tissue engineering as a scaffold material that provides biologically active molecules. The main objective of this contribution is to characterize the activation and the functionalization of titanium surfaces by the covalent immobilization of anchoring layers of self-assembled bisphosphonate neridronate monolayers and polymer films of 3-aminopropyltriethoxysilane and biomimetic poly(dopamine. These were further used to bind a bio-functional alginate coating. The success of the titanium surface activation, anchoring layer formation and alginate immobilization, as well as the stability upon immersion under physiological-like conditions, are demonstrated by different surface sensitive techniques such as spectroscopic ellipsometry, infrared reflection–absorption spectroscopy and X-ray photoelectron spectroscopy. The changes in morphology and the established continuity of the layers are examined by scanning electron microscopy, surface profilometry and atomic force microscopy. The changes in hydrophilicity after each modification step are further examined by contact angle goniometry.

  18. Development of membrane electrode assembly for high temperature proton exchange membrane fuel cell by catalyst coating membrane method

    Science.gov (United States)

    Liang, Huagen; Su, Huaneng; Pollet, Bruno G.; Pasupathi, Sivakumar

    2015-08-01

    Membrane electrode assembly (MEA), which contains cathode and anode catalytic layer, gas diffusion layers (GDL) and electrolyte membrane, is the key unit of a PEMFC. An attempt to develop MEA for ABPBI membrane based high temperature (HT) PEMFC is conducted in this work by catalyst coating membrane (CCM) method. The structure and performance of the MEA are examined by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and I-V curve. Effects of the CCM preparation method, Pt loading and binder type are investigated for the optimization of the single cell performance. Under 160 °C and atmospheric pressure, the peak power density of the MEA, with Pt loading of 0.5 mg cm-2 and 0.3 mg cm-2 for the cathode and the anode, can reach 277 mW cm-2, while a current density of 620 A cm-2 is delivered at the working voltage of 0.4 V. The MEA prepared by CCM method shows good stability operating in a short term durability test: the cell voltage maintained at ∼0.45 V without obvious drop when operated at a constant current density of 300 mA cm-2 and 160 °C under ambient pressure for 140 h.

  19. Dissipative particle dynamics simulation on the self-assembly and disassembly of pH-sensitive polymeric micelle with coating repair agent

    Science.gov (United States)

    Wang, Xiumin; Gao, Jianbang; Wang, Zhikun; Xu, Jianchang; Li, Chunling; Sun, Shuangqing; Hu, Songqing

    2017-10-01

    Dissipative particle dynamics (DPD) simulations were applied to investigate the coating repair agent dicyclopentadience (DCPD) in pH-sensitive micelles. The results show micelles self-assembled from triblock copolymers with strong hydrophobic interaction are not conducive to loading DCPD, and only micelles with weak interaction parameter can encapsulate DCPD well. After protonation, the structure of micelle was disassembled and DCPD beads have a stronger ability to shrink polymer chains and exposed to water. This work provides mesoscopic insight into self-assembly and disassembly of desired agent-loaded micelle, and might be useful for the design of new materials for agent delivery.

  20. 77 FR 6482 - Conductor Certification

    Science.gov (United States)

    2012-02-08

    ... TRANSPORTATION Federal Railroad Administration 49 CFR Part 242 Conductor Certification AGENCY: Federal Railroad..., published on November 9, 2011, which prescribed regulations for certification of conductors as required by... Certification, U.S. Department of Transportation, Federal Railroad Administration, Mail Stop-25, Room W38-323...

  1. Interacting with a Virtual Conductor

    NARCIS (Netherlands)

    Bos, P.; Reidsma, Dennis; Ruttkay, Z.M.; Nijholt, Antinus; Harper, R.; Rauterberg, M; Combetto, M.

    This paper presents a virtual embodied agent that can conduct musicians in a live performance. The virtual conductor conducts music specified by a MIDI file and uses input from a microphone to react to the tempo of the musicians. The current implementation of the virtual conductor can interact with

  2. Cluster-inspired Superionic Conductors

    Science.gov (United States)

    Fang, Hong; Jena, Puru

    Superionic conductors with desirable properties hold the key to the development of next generation of rechargeable metal-ion batteries. In this study, we report a new family of superionic conductors composed by clusters based on the antiperovskite fast-ion conductors. The new lightweight conductor shows larger electrochemical stability window and favorable thermal and mechanical properties, while maintain a high Li+-ionconductivity at room temperature and a low activation energy. We reveal the conduction mechanism of the material by identifying the relation between the orientational symmetry of the cluster rotors and the potential surface felt by the lithium ion. We also find that the mixed phase of the new conductors show further enhanced conductivity.

  3. 20 January 2014 - Members of the Regional Assemblies and Parliaments United Kingdom of Great Britain and Northern Ireland visiting the LHC tunnel at Point 8 with Technology Department, Vacuum, Surfaces and Coatings Group P. Cruikshank.

    CERN Multimedia

    Pantelia, Anna

    2014-01-01

    20 January 2014 - Members of the Regional Assemblies and Parliaments United Kingdom of Great Britain and Northern Ireland visiting the LHC tunnel at Point 8 with Technology Department, Vacuum, Surfaces and Coatings Group P. Cruikshank.

  4. Intercalated graphite electrical conductors

    Science.gov (United States)

    Banks, B. A.

    1983-01-01

    For years NASA has wanted to reduce the weight of spacecraft and aircraft. Experiments are conducted to find a lightweight synthetic metal to replace copper. The subject of this paper, intercalated graphite, is such a material. Intercalated graphite is made by heating petroleum or coal to remove the hydrogen and to form more covalent bonds, thus increasing the molecular weight. The coal or petroleum eventually turns to pitch, which can then be drawn into a fiber. With continued heating the pitch-based fiber releases hydrogen and forms a carbon fiber. The carbon fiber, if heated sufficiently, becomes more organized in parallel layers of hexagonally arranged carbon atoms in the form of graphite. A conductor of intercalated graphite is potentially useful for spacecraft or aircraft applications because of its low weight.

  5. Layer-by-layer assembled graphene-coated mesoporous SnO2 spheres as anodes for advanced Li-ion batteries

    KAUST Repository

    Shahid, Muhammad

    2014-10-01

    We report layer-by-layer (LBL) assembly of graphene/carbon-coated mesoporous SnO2 spheres (Gr/C-SnO2 spheres), without binder and conducting additives, as anode materials with excellent Li-ion insertion-extraction properties. Our results indicate that these novel LBL assembled electrodes have high reversible Li storage capacity, improved cycling, and especially good rate performance, even at high specific currents. The superior electrochemical performance offered by these LBL assembled Gr/C-SnO2 spheres is attributed to the enhanced electronic conductivity and effective diffusion of Li ions in the interconnected network of nanoparticles forming the mesoporous SnO2 spheres. © 2014 Elsevier B.V. All rights reserved.

  6. Phase-Separated, Epitaxial, Nanostructured LaMnO3+MgO Composite Cap Layer Films for Propagation of Pinning Defects in YBa2Cu3O7-x Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Wee, Sung Hun [ORNL; Shin, Junsoo [ORNL; Cantoni, Claudia [ORNL; Meyer III, Harry M [ORNL; Cook, Sylvester W [ORNL; Zuev, Yuri L [ORNL; Specht, Eliot D [ORNL; Xiong, Xuming [ORNL; Paranthaman, Mariappan Parans [ORNL; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Goyal, Amit [ORNL

    2009-01-01

    Nanostructural modulation in the cap layer used in coated conductors can be a potential source for nucleating microstructural defects into the superconducting layer for improving the flux-pinning. We report on the successful fabrication of phase separated, epitaxial, nanostructured films comprised of LaMnO{sub 3} (LMO) and MgO via pulsed laser deposition (PLD) on biaxially-textured MgO metallic templates with a LMO buffer layer. Scanning Auger compositional mapping and transmission electron microscopy cross sectional images confirm the nanoscale, spatial modulation corresponding to the nanostructured phase separation in the film. YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} films (0.8 {micro}m thick) grown using PLD on such phase separated, nanostructured cap layers show reduced field dependence of the critical current density with an ? value of -0.38 (in J{sub c}-H{sup -{alpha}}).

  7. 33 CFR 183.445 - Conductors: Protection.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Conductors: Protection. 183.445...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems Manufacturer Requirements § 183.445 Conductors: Protection. (a) Each conductor or group of conductors that passes through a bulkhead, structural...

  8. 30 CFR 56.12004 - Electrical conductors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electrical conductors. 56.12004 Section 56....12004 Electrical conductors. Electrical conductors shall be of a sufficient size and current-carrying... insulating materials. Electrical conductors exposed to mechanical damage shall be protected. ...

  9. 30 CFR 57.12004 - Electrical conductors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electrical conductors. 57.12004 Section 57... Surface and Underground § 57.12004 Electrical conductors. Electrical conductors shall be of a sufficient... operations will not damage the insulating materials. Electrical conductors exposed to mechanical damage shall...

  10. Clathrin Assembly Lymphoid Myeloid Leukemia (CALM) Protein: Localization in Endocytic-coated Pits, Interactions with Clathrin, and the Impact of Overexpression on Clathrin-mediated Traffic

    Science.gov (United States)

    Tebar, Francesc; Bohlander, Stefan K.; Sorkin, Alexander

    1999-01-01

    The clathrin assembly lymphoid myeloid leukemia (CALM) gene encodes a putative homologue of the clathrin assembly synaptic protein AP180. Hence the biochemical properties, the subcellular localization, and the role in endocytosis of a CALM protein were studied. In vitro binding and coimmunoprecipitation demonstrated that the clathrin heavy chain is the major binding partner of CALM. The bulk of cellular CALM was associated with the membrane fractions of the cell and localized to clathrin-coated areas of the plasma membrane. In the membrane fraction, CALM was present at near stoichiometric amounts relative to clathrin. To perform structure–function analysis of CALM, we engineered chimeric fusion proteins of CALM and its fragments with the green fluorescent protein (GFP). GFP–CALM was targeted to the plasma membrane–coated pits and also found colocalized with clathrin in the Golgi area. High levels of expression of GFP–CALM or its fragments with clathrin-binding activity inhibited the endocytosis of transferrin and epidermal growth factor receptors and altered the steady-state distribution of the mannose-6-phosphate receptor in the cell. In addition, GFP–CALM overexpression caused the loss of clathrin accumulation in the trans-Golgi network area, whereas the localization of the clathrin adaptor protein complex 1 in the trans-Golgi network remained unaffected. The ability of the GFP-tagged fragments of CALM to affect clathrin-mediated processes correlated with the targeting of the fragments to clathrin-coated areas and their clathrin-binding capacities. Clathrin–CALM interaction seems to be regulated by multiple contact interfaces. The C-terminal part of CALM binds clathrin heavy chain, although the full-length protein exhibited maximal ability for interaction. Altogether, the data suggest that CALM is an important component of coated pit internalization machinery, possibly involved in the regulation of clathrin recruitment to the membrane and/or the

  11. Substrate-Independent Robust and Heparin-Mimetic Hydrogel Thin Film Coating via Combined LbL Self-Assembly and Mussel-Inspired Post-Cross-linking.

    Science.gov (United States)

    Ma, Lang; Cheng, Chong; He, Chao; Nie, Chuanxiong; Deng, Jie; Sun, Shudong; Zhao, Changsheng

    2015-12-02

    In this work, we designed a robust and heparin-mimetic hydrogel thin film coating via combined layer-by-layer (LbL) self-assembly and mussel-inspired post-cross-linking. Dopamine-grafted heparin-like/-mimetic polymers (DA-g-HepLP) with abundant carboxylic and sulfonic groups were synthesized by the conjugation of adhesive molecule, DA, which exhibited substrate-independent adhesive affinity to various solid surfaces because of the formation of irreversible covalent bonds. The hydrogel thin film coated substrates were prepared by a three-step reaction: First, the substrates were coated with DA-g-HepLP to generate negatively charged surfaces. Then, multilayers were obtained via LbL coating of chitosan and the DA-g-HepLP. Finally, the noncovalent multilayers were oxidatively cross-linked by NaIO4. Surface ATR-FTIR and XPS spectra confirmed the successful fabrication of the hydrogel thin film coatings onto membrane substrates; SEM images revealed that the substrate-independent coatings owned 3D porous morphology. The soaking tests in highly alkaline, acid, and concentrated salt solutions indicated that the cross-linked hydrogel thin film coatings owned high chemical resistance. In comparison, the soaking tests in physiological solution indicated that the cross-linked hydrogel coatings owned excellent long-term stability. The live/dead cell staining and morphology observations of the adhered cells revealed that the heparin-mimetic hydrogel thin film coated substrates had low cell toxicity and high promotion ability for cell proliferation. Furthermore, systematic in vitro investigations of protein adsorption, platelet adhesion, blood clotting, and blood-related complement activation confirmed that the hydrogel film coated substrates showed excellent hemocompatibility. Both the results of inhibition zone and bactericidal activity indicated that the gentamycin sulfate loaded hydrogel thin films had significant inhibition capability toward both Escherichia coli and

  12. Gas-Barrier Hybrid Coatings by the Assembly of Novel Poly(vinyl alcohol) and Reduced Graphene Oxide Layers through Cross-Linking with Zirconium Adducts.

    Science.gov (United States)

    Yan, Ning; Capezzuto, Filomena; Buonocore, Giovanna G; Lavorgna, Marino; Xia, Hesheng; Ambrosio, Luigi

    2015-10-14

    Gas-barrier materials obtained by coating poly(ethylene terephthalate) (PET) substrates have already been studied in the recent literature. However, because of the benefits of using cheaper, biodegradable, and nonpolar polymers, multilayered hybrid coatings consisting of alternate layers of reduced graphene oxide (rGO) nanosheets and a novel high amorphous vinyl alcohol (HAVOH) with zirconium (Zr) adducts as binders were successfully fabricated through a layer-by-layer (LbL) assembly approach. Atomic force microscopy analysis showed that rGO nanoplatelets were uniformly dispersed over the HAVOH polymer substrate. Scanning and transmission electron microscopies revealed that multilayer (HAVOH/Zr/rGO)n hybrid coatings exhibited a brick-wall structure with HAVOH and rGO as buildings blocks. It has been shown that 40 layers of HAVOH/Zr/rGO ultrathin films deposited on PET substrates lead to a decrease of 1 order of magnitude of oxygen permeability with respect to the pristine PET substrate. This is attributed to the effect of zirconium polymeric adducts, which enhance the assembling efficiency of rGO and compact the layers, as confirmed by NMR characterization, resulting in a significant increment of the oxygen-transport pathways. Because of their high barrier properties and high flexibility, these films are promising candidates in a variety of applications such as packaging, selective gas films, and protection of flexible electronics.

  13. Surface coating of siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers: Enhanced gene silencing and reduced adversed effects in vitro

    DEFF Research Database (Denmark)

    Zeng, Xianghui; de Groot, A. M.; Sijts, Alice

    2015-01-01

    Cationic vectors have demonstrated the potential to facilitate intracellular delivery of therapeutic oligonucleotides. However, enhanced transfection efficiency is usually associated with adverse effects, which also proves to be a challenge for vectors based on cationic peptides. In this study...... a series of proteolytically stable palmitoylated α-peptide/β-peptoid peptidomimetics with a systematically varied number of repeating lysine and homoarginine residues was shown to self-assemble with small interfering RNA (siRNA). The resulting well-defined nanocomplexes were coated with anionic lipids...... not display any noticeable cytotoxicity and immunogenicity in vitro. In contrast, the corresponding nanocomplexes mediated a reduced silencing effect with a more narrow safety window. The surface coating with anionic lipid bilayers led to partial decomplexation of the siRNA–peptidomimetic nanocomplex core...

  14. Updated sesame genome assembly and fine mapping of plant height and seed coat color QTLs using a new high-density genetic map.

    Science.gov (United States)

    Wang, Linhai; Xia, Qiuju; Zhang, Yanxin; Zhu, Xiaodong; Zhu, Xiaofeng; Li, Donghua; Ni, Xuemei; Gao, Yuan; Xiang, Haitao; Wei, Xin; Yu, Jingyin; Quan, Zhiwu; Zhang, Xiurong

    2016-01-05

    Sesame is an important high-quality oil seed crop. The sesame genome was de novo sequenced and assembled in 2014 (version 1.0); however, the number of anchored pseudomolecules was higher than the chromosome number (2n = 2x = 26) due to the lack of a high-density genetic map with 13 linkage groups. We resequenced a permanent population consisting of 430 recombinant inbred lines and constructed a genetic map to improve the sesame genome assembly. We successfully anchored 327 scaffolds onto 13 pseudomolecules. The new genome assembly (version 2.0) included 97.5 % of the scaffolds greater than 150 kb in size present in assembly version 1.0 and increased the total pseudomolecule length from 233.7 to 258.4 Mb with 94.3 % of the genome assembled and 97.2 % of the predicted gene models anchored. Based on the new genome assembly, a bin map including 1,522 bins spanning 1090.99 cM was generated and used to identified 41 quantitative trait loci (QTLs) for sesame plant height and 9 for seed coat color. The plant height-related QTLs explained 3-24 % the phenotypic variation (mean value, 8 %), and 29 of them were detected in at least two field trials. Two major loci (qPH-8.2 and qPH-3.3) that contributed 23 and 18 % of the plant height were located in 350 and 928-kb spaces on Chr8 and Chr3, respectively. qPH-3.3, is predicted to be responsible for the semi-dwarf sesame plant phenotype and contains 102 candidate genes. This is the first report of a sesame semi-dwarf locus and provides an interesting opportunity for a plant architecture study of the sesame. For the sesame seed coat color, the QTLs of the color spaces L*, a*, and b* were detected with contribution rates of 3-46 %. qSCb-4.1 contributed approximately 39 % of the b* value and was located on Chr4 in a 199.9-kb space. A list of 32 candidate genes for the locus, including a predicted black seed coat-related gene, was determined by screening the newly anchored genome. This study offers a high

  15. Zinc oxyfluoride transparent conductor

    Science.gov (United States)

    Gordon, Roy G.

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  16. Importance of sialic acid residues illuminated by live animal imaging using phosphorylcholine self-assembled monolayer-coated quantum dots.

    Science.gov (United States)

    Ohyanagi, Tatsuya; Nagahori, Noriko; Shimawaki, Ken; Hinou, Hiroshi; Yamashita, Tadashi; Sasaki, Akira; Jin, Takashi; Iwanaga, Toshihiko; Kinjo, Masataka; Nishimura, Shin-ichiro

    2011-08-17

    Glycans are expected to be one of the potential signal molecules for controlling drug targeting/delivery or long-term circulation of biopharmaceuticals. However, the effect of the carbohydrates of artificially glycosylated derivatives on in vivo dynamic distribution profiles after intravenous injection of model animals remains unclear due to the lack of standardized methodology and a suitable platform. We report herein an efficient and versatile method for the preparation of multifunctional quantum dots (QDs) displaying common synthetic glycosides with excellent solubility and long-term stability in aqueous solution without loss of quantum yields. Combined use of an aminooxy-terminated thiol derivative, 11,11'-dithio bis[undec-11-yl 12-(aminooxyacetyl)amino hexa(ethyleneglycol)], and a phosphorylcholine derivative, 11-mercaptoundecylphosphorylcholine, provided QDs with novel functions for the chemical ligation of ketone-functionalized compounds and the prevention of nonspecific protein adsorption concurrently. In vivo near-infrared (NIR) fluorescence imaging of phosphorylcholine self-assembled monolayer (SAM)-coated QDs displaying various simple sugars (glyco-PC-QDs) after administration into the tail vein of the mouse revealed that distinct long-term delocalization over 2 h can be achieved in cases of QDs modified with α-sialic acid residue (Neu5Ac-PC-QDs) and control PC-QDs, while QDs bearing other common sugars, such as α-glucose (Glc-PC-QDs), α-mannose (Man-PC-QDs), α-fucose (Fuc-PC-QDs), lactose (Lac-PC-QDs), β-glucuronic acid (GlcA-PC-QDs), N-acetyl-β-D-glucosamine (GlcNAc-PC-QDs), and N-acetyl-β-D-galactosamine (GalNAc-PC-QDs) residues, accumulated rapidly (5-10 min) in the liver. Sequential enzymatic modifications of GlcNAc-PC-QDs gave Galβ1,4GlcNAc-PC-QDs (LacNAc-PC-QDs), Galβ1,4(Fucα1,3)GlcNAc-PC-QDs (Le(x)-PC-QDs), Neu5Acα2,3Galβ1,4GlcNAc-PC-QDs (sialyl LacNAc-PC-QDs), and Neu5Acα2,3Galβ1,4(Fucα1,3)GlcNAc-PC-QDs (sialyl Le(x)-PC-QDs) in

  17. Surface coating of siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers: enhanced gene silencing and reduced adverse effects in vitro

    Science.gov (United States)

    Zeng, Xianghui; de Groot, Anne Marit; Sijts, Alice J. A. M.; Broere, Femke; Oude Blenke, Erik; Colombo, Stefano; van Eden, Willem; Franzyk, Henrik; Nielsen, Hanne Mørck; Foged, Camilla

    2015-11-01

    Cationic vectors have demonstrated the potential to facilitate intracellular delivery of therapeutic oligonucleotides. However, enhanced transfection efficiency is usually associated with adverse effects, which also proves to be a challenge for vectors based on cationic peptides. In this study a series of proteolytically stable palmitoylated α-peptide/β-peptoid peptidomimetics with a systematically varied number of repeating lysine and homoarginine residues was shown to self-assemble with small interfering RNA (siRNA). The resulting well-defined nanocomplexes were coated with anionic lipids giving rise to net anionic liposomes. These complexes and the corresponding liposomes were optimized towards efficient gene silencing and low adverse effects. The optimal anionic liposomes mediated a high silencing effect, which was comparable to that of the control (cationic Lipofectamine 2000), and did not display any noticeable cytotoxicity and immunogenicity in vitro. In contrast, the corresponding nanocomplexes mediated a reduced silencing effect with a more narrow safety window. The surface coating with anionic lipid bilayers led to partial decomplexation of the siRNA-peptidomimetic nanocomplex core of the liposomes, which facilitated siRNA release. Additionally, the optimal anionic liposomes showed efficient intracellular uptake and endosomal escape. Therefore, these findings suggest that a more efficacious and safe formulation can be achieved by surface coating of the siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers.Cationic vectors have demonstrated the potential to facilitate intracellular delivery of therapeutic oligonucleotides. However, enhanced transfection efficiency is usually associated with adverse effects, which also proves to be a challenge for vectors based on cationic peptides. In this study a series of proteolytically stable palmitoylated α-peptide/β-peptoid peptidomimetics with a systematically varied number of repeating lysine

  18. Quartz antenna with hollow conductor

    Science.gov (United States)

    Leung, Ka-Ngo; Benabou, Elie

    2002-01-01

    A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.

  19. Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for blood cancer detection

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Chandra Mouli [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Nanobioelectronics Laboratory, Department of Biotechnology, Delhi Technological University, Delhi 110042 (India); Dewan, Srishti [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Biomedical Engineering Department, Deenbandhu Chhotu Ram University of Science & Technology, Haryana 131039 (India); Chawla, Seema [Biomedical Engineering Department, Deenbandhu Chhotu Ram University of Science & Technology, Haryana 131039 (India); Yadav, Birendra Kumar [Rajiv Gandhi Cancer Institute and Research Centre, Rohini, Delhi 110085 (India); Sumana, Gajjala, E-mail: sumanagajjala@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Malhotra, Bansi Dhar, E-mail: bansi.malhotra@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Nanobioelectronics Laboratory, Department of Biotechnology, Delhi Technological University, Delhi 110042 (India)

    2016-09-21

    We report results of the studies relating to controlled deposition of the amino-functionalized silica-coated zinc oxide (Am-Si@ZnO) nano-assemblies onto an indium tin oxide (ITO) coated glass substrate using Langmuir-Blodgett (LB) technique. The monolayers have been deposited by transferring the spread solution of Am-Si@ZnO stearic acid prepared in chloroform at the air-water interface, at optimized pressure (16 mN/m), concentration (10 mg/ml) and temperature (23 °C). The high-resolution transmission electron microscopic studies of the Am-Si@ZnO nanocomposite reveal that the nanoparticles have a microscopic structure comprising of hexagonal assemblies of ZnO with typical dimensions of 30 nm. The surface morphology of the LB multilayer observed by scanning electron microscopy shows uniform surface of the Am-Si@ZnO film in the nanometer range (<80 nm). These electrodes have been utilized for chronic myelogenous leukemia (CML) detection by covalently immobilizing the amino-terminated oligonucleotide probe sequence via glutaraldehyde as a crosslinker. The response studies of these fabricated electrodes carried out using electrochemical impedance spectroscopy show that this Am-Si@ZnO LB film based nucleic acid sensor exhibits a linear response to complementary DNA (10{sup −6}–10{sup −16} M) with a detection limit of 1 × 10{sup −16} M. This fabricated platform is validated with clinical samples of CML positive patients and the results demonstrate its immense potential for clinical diagnosis. - Graphical abstract: Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for label free electrochemical detection of chronic myelogenous leukemia. - Highlights: • Stable and controlled deposition of Am-Si@ZnO nano-assemblies using LB technique. • Uniform monolayer deposition of the Am-Si@ZnO LB film within the nanometer range. • Am-Si@ZnO LB film shows enhanced electrochemical properties. • Fabricated

  20. Development of 1 m HTS conductor using YBCO on textured metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, M., E-mail: m-yagi@ch.furukawa.co.j [Furukawa Electric Co., Ltd, 6, Yawata-Kaigandori, Ichihara, Chiba 290-8555 (Japan); Sakamoto, H. [Furukawa Electric Co., Ltd, 500, Kiyotaki-machi, Nikko, Tochigi 321-1493 (Japan); Mukoyama, S. [Furukawa Electric Co., Ltd, 6, Yawata-Kaigandori, Ichihara, Chiba 290-8555 (Japan); Yamamoto, K. [Furukawa Electric Co., Ltd, 500, Kiyotaki-machi, Nikko, Tochigi 321-1493 (Japan); Amemiya, N. [Kyoto University, Kyotodaigaku-Katsura, Nishikyo, Kyoto 615-8510 (Japan); Nagaya, S.; Kashima, N. [Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Shiohara, Y. [Superconductivity Research Laboratory, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2009-10-15

    We fabricated 1 m high temperature superconducting conductor (HTS conductor) using YBa{sub 2}Cu{sub 3}O{sub 7-x} coated conductors (YBCO tapes) on textured metal substrates, which are expected to be lower in cost than YBCO tapes using ion-beam assisted deposition. Those substrate and intermediate layers were manufactured by Furukawa Electric, and YBCO and a protective layer were applied to the intermediate layer by Chubu Electric Power. Before fabricating the conductor, a 0.1 mm thick copper tape was soldered to the YBCO tape, and 10 mm wide YBCO tape was divided into three strips by a YAG laser. To have sufficient current capacity for 1 kA, a two-layer conductor was fabricated, and its critical current (I{sub c}) was 1976 A, but the magnetic properties of the textured metal substrates affected the increase in AC loss. In a low current region, the AC loss in this conductor was much higher than the Norris strip model, but approached the Norris strip model in the high current region because the magnetization was almost saturated. Low AC loss of 0.144 W/m at 1 kA{sub rms} was achieved even though the conductor had a small outer diameter of 20 mm and was composed of YBCO tapes with magnetic substrates.

  1. 33 CFR 183.425 - Conductors: General.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Conductors: General. 183.425...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems Manufacturer Requirements § 183.425 Conductors: General. (a) Each conductor must be insulated, stranded copper. (b) Except for intermittent...

  2. 33 CFR 159.73 - Conductors.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Conductors. 159.73 Section 159.73 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.73 Conductors. Current carrying conductors must be...

  3. Facile Layer-by-Layer Self-Assembly toward Enantiomeric Poly(lactide) Stereocomplex Coated Magnetite Nanocarrier for Highly Tunable Drug Deliveries.

    Science.gov (United States)

    Li, Zibiao; Yuan, Du; Jin, Guorui; Tan, Beng H; He, Chaobin

    2016-01-27

    A highly tunable nanoparticle (NP) system with multifunctionalities was developed as drug nanocarrier via a facile layer-by-layer (LbL) stereocomplex (SC) self-assembly of enantiomeric poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) in solution using silica-coated magnetite (Fe3O4@SiO2) as template. The poly(lactide) (PLA) SC coated NPs (Fe3O4@SiO2@-SC) were further endowed with different stimuli-responsiveness by controlling the outermost layer coatings with respective pH-sensitive poly(lactic acid)-poly(2-dimethylaminoethyl methacrylate) (PLA-D) and temperature-sensitive poly(lactic acid)-poly(N-isopropylacrylamide) (PLA-N) diblock copolymers to yield Fe3O4@SiO2@SC-D and Fe3O4@SiO2@SC-N NPs, respectively, while the superparamagnetic properties of Fe3O4 were maintained. TEM images show a clearly resolved core-shell structure with a silica layer and sequential PLA SC co/polymer coating layers in the respective NPs. The well-designed NPs possess a size distribution in a range of 220-270 nm and high magnetization of 70.8-72.1 emu/g [Fe3O4]. More importantly, a drug release study from the as-constructed stimuli-responsive NPs exhibited sustained release profiles and the rates of release can be tuned by variation of external environments. Further cytotoxicity and cell culture studies revealed that PLA SC coated NPs possessed good cell biocompatibility and the doxorubicin (DOX)-loaded NPs showed enhanced drug delivery efficiency toward MCF-7 cancer cells. Together with the strong magnetic sensitivity, the developed hybrid NPs demonstrate a great potential of control over the drug release at a targeted site. The developed coating method can be further optimized to finely tune the nanocarrier size and operating range of pHs and temperatures for in vivo applications.

  4. Insulation assembly for electric machine

    Science.gov (United States)

    Rhoads, Frederick W.; Titmuss, David F.; Parish, Harold; Campbell, John D.

    2013-10-15

    An insulation assembly is provided that includes a generally annularly-shaped main body and at least two spaced-apart fingers extending radially inwards from the main body. The spaced-apart fingers define a gap between the fingers. A slot liner may be inserted within the gap. The main body may include a plurality of circumferentially distributed segments. Each one of the plurality of segments may be operatively connected to another of the plurality of segments to form the continuous main body. The slot liner may be formed as a single extruded piece defining a plurality of cavities. A plurality of conductors (extendable from the stator assembly) may be axially inserted within a respective one of the plurality of cavities. The insulation assembly electrically isolates the conductors in the electric motor from the stator stack and from other conductors.

  5. One-Step Self-Assembly Synthesis α-Fe2O3 with Carbon-Coated Nanoparticles for Stabilized and Enhanced Supercapacitors Electrode

    Directory of Open Access Journals (Sweden)

    Yizhi Yan

    2017-08-01

    Full Text Available A cocoon-like α-Fe2O3 nanocomposite with a novel carbon-coated structure was synthesized via a simple one-step hydrothermal self-assembly method and employed as supercapacitor electrode material. It was observed from electrochemical measurements that the obtained α-Fe2O3@C electrode showed a good specific capacitance (406.9 Fg−1 at 0.5 Ag−1 and excellent cycling stability, with 90.7% specific capacitance retained after 2000 cycles at high current density of 10 Ag−1. These impressive results, presented here, demonstrated that α-Fe2O3@C could be a promising alternative material for application in high energy density storage.

  6. Membrane electrode assembly with enhanced platinum utilization for high temperature proton exchange membrane fuel cell prepared by catalyst coating membrane method

    Science.gov (United States)

    Liang, Huagen; Su, Huaneng; Pollet, Bruno G.; Linkov, Vladimir; Pasupathi, Sivakumar

    2014-11-01

    In this work, membrane electrode assemblies (MEAs) prepared by catalyst coating membrane (CCM) method are investigated for reduced platinum (Pt) loading and improved Pt utilization of high temperature proton exchange membrane fuel cell (PEMFC) based on phosphoric acid (PA)-doped poly(2,5-benzimidazole) (AB-PBI) membrane. The results show that CCM method exhibits significantly higher cell performance and Pt-specific power density than that of MEAs prepared with conventional gas diffusion electrode (GDE) under a low Pt loading level. In-suit cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the MEAs prepared by the CCM method have a higher electrochemical surface area (ECSA), low cell ohmic resistance and low charge transfer resistance as compared to those prepared with GDEs at the same Pt loading.

  7. A universal cooperative assembly-directed method for coating of mesoporous TiO2 nanoshells with enhanced lithium storage properties

    Science.gov (United States)

    Guan, Bu Yuan; Yu, Le; Li, Ju; Lou, Xiong Wen (David)

    2016-01-01

    TiO2 is exceptionally useful, but it remains a great challenge to develop a universal method to coat TiO2 nanoshells on different functional materials. We report a one-pot, low-temperature, and facile method that can rapidly form mesoporous TiO2 shells on various inorganic, organic, and inorganic-organic composite materials, including silica-based, metal, metal oxide, organic polymer, carbon-based, and metal-organic framework nanomaterials via a cooperative assembly-directed strategy. In constructing hollow, core-shell, and yolk-shell geometries, both amorphous and crystalline TiO2 nanoshells are demonstrated with excellent control. When used as electrode materials for lithium ion batteries, these crystalline TiO2 nanoshells composed of very small nanocrystals exhibit remarkably long-term cycling stability over 1000 cycles. The electrochemical properties demonstrate that these TiO2 nanoshells are promising anode materials. PMID:26973879

  8. Nano-assemblies consisting of Pd/Pt nanodendrites and poly (diallyldimethylammonium chloride)-coated reduced graphene oxide on glassy carbon electrode for hydrogen peroxide sensors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yanyan; Zhang, Cong; Zhang, Di; Ma, Min; Wang, Weizhen; Chen, Qiang, E-mail: qiangchen@nankai.edu.cn

    2016-01-01

    Non-enzymatic hydrogen peroxide (H{sub 2}O{sub 2}) sensors were fabricated on the basis of glassy carbon (GC) electrode modified with palladium (Pd) core-platinum (Pt) nanodendrites (Pt-NDs) and poly (diallyldimethylammonium chloride) (PDDA)-coated reduced graphene oxide (rGO). A facile wet-chemical method was developed for preparing Pd core-Pt nanodendrites. In this approach, the growth of Pt NDs was directed by Pd nanocrystal which could be regarded as seed. The PDDA-coated rGO could form uniform film on the surface of GC electrode, which provided a support for Pd core- Pt NDs adsorption by self-assembly. The morphologies of the nanocomposites were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (spectrum). Electrocatalytic ability of the nanocomposites was evaluated by cyclic voltammetry and chronoamperometric methods. The sensor fabricated by Pd core-Pt NDs/PDDA-rGO/GCE exhibited high sensitivity (672.753 μA mM{sup −1} cm{sup −2}), low detection limit (0.027 μM), wider linear range (0.005–0.5 mM) and rapid response time (within 5 s). Besides, it also exhibited superior reproducibility, excellent anti-interference performance and long-term stability. The present work could afford a viable method and efficient platform for fabricating all kinds of amperometric sensors and biosensors. - Highlights: • A facial wet-chemical method was developed for preparing Pd core-Pt nanodendrites. • The morphologies of graphene and Pd core-Pt nanodendrites were characterized. • A novel H{sub 2}O{sub 2} sensor was fabricated by nano-assembly. • The performance of H{sub 2}O{sub 2} sensor was evaluated by cyclic voltammetry and chronoamperometric methods.

  9. Perovskite solar cells with CuI inorganic hole conductor

    Science.gov (United States)

    Takahashi, Kenta; Suzuki, Yoshikazu

    2017-08-01

    An organic material, 2,2‧,7,7‧-tetrakis(N,N-di-p-methoxyphenylamine)9,9‧-spirobifluorene (spiro-OMeTAD), is generally used as a hole conductor of perovskite solar cells (PSCs), but spiro-OMeTAD is much more expensive than other materials used in PSCs. In this study, we have prepared PSCs with a cost-effective CuI hole transport layer by spin coating. The merit of using spin coating for CuI is good compatibility with other steps, such as spin coating of a TiO2 electron transport layer and a perovskite active layer. The CuI-based PSC recorded power conversion efficiencies of η = 2.22% (max) on the day of production and η = 6.52% (max) after the 20 days of production. Moreover, the CuI-based PSC had a smaller hysteresis than the spiro-based PSC, suggesting that CuI is a highly promising alternative hole conductor for PSCs.

  10. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  11. Temperature limited heater utilizing non-ferromagnetic conductor

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar,; Harold J. (Bellaire, TX), Harris; Kelvin, Christopher [Houston, TX

    2012-07-17

    A heater is described. The heater includes a ferromagnetic conductor and an electrical conductor electrically coupled to the ferromagnetic conductor. The ferromagnetic conductor is positioned relative to the electrical conductor such that an electromagnetic field produced by time-varying current flow in the ferromagnetic conductor confines a majority of the flow of the electrical current to the electrical conductor at temperatures below or near a selected temperature.

  12. Pulse Propagation on close conductors

    CERN Document Server

    Dieckmann, A

    2001-01-01

    The propagation and reflection of arbitrarily shaped pulses on non-dispersive parallel conductors of finite length with user defined cross section is simulated employing the discretized telegraph equation. The geometry of the system of conductors and the presence of dielectric material determine the capacities and inductances that enter the calculation. The values of these parameters are found using an iterative Laplace equation solving procedure and confirmed for certain calculable geometries including the line charge inside a box. The evolving pulses and the resulting crosstalk can be plotted at any instant and - in the Mathematica notebook version of this report - be looked at in an animation. As an example a differential pair of microstrips as used in the ATLAS vertex detector is analysed.

  13. Sensor for finding conductor dancing

    Energy Technology Data Exchange (ETDEWEB)

    Rudakova, R.M.; Drapeko, Yu.A.; Guzairov, M.B.

    1982-01-01

    The sensor has a current conducting housing and sensitive element in the form of a flat spring. On one end there is a small weight. The other end of the spring is connected in the center of the EI-washer installed at the end of the current conducting housing. With acceleration of dancing of the overhead line conductors exceeding the assigned magnitude, the weight is pressed to the current conducting housing and a signal appears which, for example, can be transmitted on a radio channel to the substation. Improvement in the efficiency of finding the dancing is associated with the fact that the proposed sensor measures the parameters of dancing directly on the conductor and its operation is not influenced by the operating mode of the overhead line.

  14. Method for making conductors for ferrite memory arrays. [from pre-formed metal conductors

    Science.gov (United States)

    Heckler, C. H.; Baba, P. D.; Bhiwandker, N. C. (Inventor)

    1974-01-01

    The ferrite memory arrays are made from pre-formed metal conductors for the ferrite arrays. The conductors are made by forming a thin sheet of a metallizing paste of metal alloy powder, drying the paste layer, bisque firing the dried sheet at a first temperature, and then punching the conductors from the fired sheet. During the bisque firing, the conductor sheet shrinks to 58 percent of its pre-fired volume and the alloy particles sinter together. The conductors are embedded in ferrite sheet material and finally fired at a second higher temperature during which firing the conductors shrink approximately the same degree as the ferrite material.

  15. Graphene, a promising transparent conductor

    OpenAIRE

    Wassei, Jonathan K.; Kaner, Richard B.

    2010-01-01

    New electronic devices such as touch screens, flexible displays, printable electronics, solid-state lighting and thin film photovoltaics have led to a rapidly growing market for flexible transparent conductors. Standard indium tin oxide films are unlikely to satisfy future needs due to losses in conductivity on bending and the escalating cost of indium which is in limited supply. Recent advances in the synthesis and characterization of graphene indicate that it may be suitable for many electr...

  16. Manufacture of ITER feeder sample conductors

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Jinggang, E-mail: qinjg@163.com [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Wu, Yu; Yu, Min; Liu, Bo [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Liu, Huajun, E-mail: liuhj@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Weiss, Klaus-Peter [Institute for Technical Physics, Karlsruhe Institute of Technology, Karlsruhe D-76344 (Germany); Li, Laifeng [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Li, Hongwei; Niu, Erwu [China International Nuclear Fusion Energy Program Execution Center, Beijing 100862 (China); Bruzzone, Pierluigi [EPFL-CRPP, Fusion Technology, 5232 Villigen (Switzerland)

    2013-10-15

    Highlights: ► Develop the technique of MB conductor. ► Develop the technique of CB conductor. ► Sultan test results show that MB and CB samples have good performance. -- Abstract: The ITER feeders are the components that connect the ITER magnet systems located inside the main cryostat to the cryogenics, power-supply and control system interfaces outside the cryostat. The feeder busbars rely on the Cable-In-Conduit Conductor (CICC) design concept as all the conductors for the ITER magnet systems. There are two types of busbars for the feeder systems. One is the Main Busbar (MB) for the TF, CS and PF feeders, and the other is the Corrector Busbar (CB) for the CC feeders. The busbar cable is wound from multiple stage sub-cables made with Cu and superconducting strands. The superconducting material is NbTi for the busbar strands of all feeder systems. All Feeder conductors are provided by China. The R and D programs are needed to acquire knowledge on the behavior of such conductors. Since the conductors are new, some full size copper dummy conductors have been produced for the testing of the cabling parameters, definition of automatic TIG welding of seamless jacket section, elaboration of cable insertion and compaction. Then, two short qualification conductor samples (MB and CB) are prepared in ASIPP, and NbTi advanced strands are produced by Western Superconductor Technology (WST). The details of manufacturing procedures for Feeder conductor samples will be described in this paper.

  17. Transparent conductors based on microscale/nanoscale materials for high performance devices

    Science.gov (United States)

    Gao, Tongchuan

    Transparent conductors are important as the top electrode for a variety of optoelectronic devices, including solar cells, light-emitting diodes (LEDs), at panel displays, and touch screens. Doped indium tin oxide (ITO) thin films are the predominant transparent conductor material. However, ITO thin films are brittle, making them unsuitable for the emerging flexible devices, and suffer from high material and processing cost. In my thesis, we developed a variety of transparent conductors toward a performance comparable with or superior to ITO thin films, with lower cost and potential for scalable manufacturing. Metal nanomesh (NM), hierarchical graphene/metal microgrid (MG), and hierarchical metal NM/MG materials were investigated. Simulation methods were used as a powerful tool to predict the transparency and sheet resistance of the transparent conductors by solving Maxwell's equations and Poisson's equation. Affordable and scalable fabrication processes were developed thereafter. Transparent conductors with over 90% transparency and less than 10 O/square sheet resistance were successfully fabricated on both rigid and flexible substrates. Durability tests, such as bending, heating and tape tests, were carried out to evaluate the robustness of the samples. Haze factor, which characterizes how blurry a transparent conductor appears, was also studied in-depth using analytical calculation and numerical simulation. We demonstrated a tunable haze factor for metal NM transparent conductors and analyzed the principle for tuning the haze factor. Plasmonic effects, excited by some transparent conductors, can lead to enhanced performance in photovoltaic devices. We systematically studied the effect of incorporating metal NM into ultrathin film silicon solar cells using numerical simulation, with the aid of optimization algorithms to reduce the optimization time. Mechanisms contributing to the enhanced performance were then identified and analyzed. Over 72% enhancement in short

  18. The use of layer by layer self-assembled coatings of hyaluronic acid and cationized gelatin to improve the biocompatibility of poly(ethylene terephthalate) artificial ligaments for reconstruction of the anterior cruciate ligament.

    Science.gov (United States)

    Li, Hong; Chen, Chen; Zhang, Shurong; Jiang, Jia; Tao, Hongyue; Xu, Jialing; Sun, Jianguo; Zhong, Wei; Chen, Shiyi

    2012-11-01

    In this study layer by layer (LBL) self-assembled coatings of hyaluronic acid (HA) and cationized gelatin (CG) were used to modify polyethylene terephthalate (PET) artificial ligament grafts. Changes in the surface properties were characterized by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and contact angle and biomechanical measurements. The cell compatibility of this HA-CG coating was investigated in vitro on PET films seeded with human foreskin dermal fibroblasts over 7days. The results of our in vitro studies demonstrated that the HA-CG coating significantly enhanced cell adhesion, facilitated cell growth, and suppressed the expression of inflammation-related genes relative to a pure PET graft. Furthermore, rabbit and porcine anterior cruciate ligament reconstruction models were used to evaluate the effect of this LBL coating in vivo. The animal experiment results proved that this LBL coating significantly inhibited inflammatory cell infiltration and promoted new ligament tissue regeneration among the graft fibers. In addition, the formation of type I collagen in the HA-CG coating group was much higher than in the control group. Based on these results we conclude that PET grafts coated with HA-CG have considerable potential as substitutes for ligament reconstruction. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. Interaction of endothelial and smooth muscle cells with cobalt-chromium alloy surfaces coated with paclitaxel deposited self-assembled monolayers.

    Science.gov (United States)

    Lamichhane, Sujan; Lancaster, Susan; Thiruppathi, Eagappanath; Mani, Gopinath

    2013-11-19

    The use of self-assembled monolayers (SAMs) as a polymer-free platform to deliver an antiproliferative drug, paclitaxel (PAT), from a stent material cobalt-chromium (CoCr) alloy has been previously demonstrated. In this study, the interaction of human aortic endothelial cells (ECs) and human aortic smooth muscle cells (SMCs) with CoCr alloy surfaces coated with SAMs- (SAMs-CoCr) and PAT-deposited SAMs (PAT-SAMs-CoCr) was investigated. A polished CoCr with no coatings was used as a control. The viability, proliferation, morphology, and phenotype of ECs and SMCs were investigated on these samples. SAMs-CoCr significantly enhanced the growth of ECs. Also, the ECs were well spreading with its typical morphological features and showed stronger PECAM-1 expression on SAMs-CoCr. This showed that the SAMs-CoCr surface is conducive to endothelialization. For PAT-SAMs-CoCr, although the adhesion of ECs was lower, the cells continued to proliferate with some degree of spreading and limited PECAM-1 expression. For SMCs, a significant decrease in the cell proliferation was observed on SAMs-CoCr when compared with that of Control-CoCr. PAT-SAMs-CoCr showed maximum inhibitory effect on the proliferation of SMCs. Also, the SMCs on PAT-SAMs-CoCr displayed a poorly spread discoid morphology with disarranged α-actin filaments. This showed that the PAT released from the SAMs platform successfully inhibited the growth of SMCs. Thus, this study showed the interaction of ECs and SMCs with SAMs-CoCr and PAT-SAMs-CoCr for potential uses in stents and other cardiovascular medical devices.

  20. Effect of mixed pinning landscapes produced by 6 MeV oxygen irradiation on the resulting critical current densities Jc in 1.3 μm thick GdBa2Cu3O7-d coated conductors grown by co-evaporation

    Science.gov (United States)

    Haberkorn, N.; Suárez, S.; Pérez, P. D.; Troiani, H.; Granell, P.; Golmar, F.; Lee, Jae-Hun; Moon, S. H.

    2017-11-01

    We report the influence of crystalline defects introduced by 6 MeV 16O3+ irradiation on the critical current densities Jc and flux creep rates in 1.3 μm thick GdBa2Cu3O7-δ coated conductor produced by co-evaporation. Pristine films with pinning produced mainly by random nanoparticles with diameter close to 50 nm were irradiated with doses between 2 × 1013 cm-2 and 4 × 1014 cm-2. The irradiations were performed with the ion beam perpendicular to the surface of the samples. The Jc and the flux creep rates were analyzed for two magnetic field configurations: magnetic field applied parallel (H║c) and at 45° (H║45°) to the c-axis. The results show that at temperatures below 40 K the in-field Jc dependences can be significantly improved by irradiation. For doses of 1 × 1014 cm-2 the Jc values at μ0H = 5 T are doubled without affecting significantly the Jc at small fields. Analyzing the flux creep rates as function of the temperature in both magnetic field configurations, it can be observed that the irradiation suppresses the peak associated with double-kink relaxation and increases the flux creep rates at intermediate and high temperatures. Under 0.5 T, the flux relaxation for H‖c and H||45° in pristine films presents characteristic glassy exponents μ = 1.63 and μ = 1.45, respectively. For samples irradiated with 1 × 1014 cm-2, these values drop to μ = 1.45 and μ = 1.24, respectively

  1. A New Coating Process for Production of Coated Magnesium Powders

    National Research Council Canada - National Science Library

    2008-01-01

    .... In brief, Task 1 involved the construction and assembly of the coating system and supporting infrastructure, which was used for the scale-up and production of 1-lb batches of coated magnesium powder...

  2. Solid-state proton conductors

    Energy Technology Data Exchange (ETDEWEB)

    Jewulski, J.R.; Osif, T.L.; Remick, R.J.

    1990-12-01

    The purpose of this program was to survey the field of solid-state proton conductors (SSPC), identify conductors that could be used to develop solid-state fuel cells suitable for use with coal derived fuel gases, and begin the experimental research required for the development of these fuel cells. This document covers the following topics: the history of developments and current status of the SSPC, including a review of proton conducting electrolyte structures, the current status of the medium temperature SSPC development, electrodes for moderate temperature (SSPC) fuel cell, basic material and measurement techniques applicable for SSPC development, modeling and optimization studies. Correlation and optimization studies, to include correlation studies on proton conduction and oxide cathode optimization for the SSPC fuel cell. Experiments with the SSPC fuel cells including the fabrication of the electrolyte disks, apparatus for conducting measurements, the strontium-cerium based electrolyte, the barium-cerium based electrolyte with solid foil electrodes, the barium-cerium based electrolyte with porous electrodes, and conduction mechanisms. 164 refs., 27 figs., 13 tabs.

  3. 46 CFR 111.15-20 - Conductors.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Conductors. 111.15-20 Section 111.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-20 Conductors. (a...

  4. Assessment of sodium conductor distribution cable

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    The study assesses the barriers and incentives for using sodium conductor distribution cable. The assessment considers environmental, safety, energy conservation, electrical performance and economic factors. Along with all of these factors considered in the assessment, the sodium distribution cable system is compared to the present day alternative - an aluminum conductor system. (TFD)

  5. Doped LZO buffer layers for laminated conductors

    Science.gov (United States)

    Paranthaman, Mariappan Parans [Knoxville, TN; Schoop, Urs [Westborough, MA; Goyal, Amit [Knoxville, TN; Thieme, Cornelis Leo Hans [Westborough, MA; Verebelyi, Darren T [Oxford, MA; Rupich, Martin W [Framingham, MA

    2010-03-23

    A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the substrate, the biaxially textured buffer layer comprising LZO and a dopant for mitigating metal diffusion through the LZO, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.

  6. Dispersive micro-solid phase extraction based on self-assembling, ionic liquid-coated magnetic particles for the determination of clofentezine and chlorfenapyr in environmental water samples.

    Science.gov (United States)

    Peng, Bing; Zhang, Jiaheng; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang

    2013-11-21

    Two ionic liquid-coated-Fe3O4 magnetic particles (IL-Fe3O4 MPs) were developed for use in two types of dispersive micro-solid phase extraction (D-μ-SPE) for the high-performance liquid chromatographic analysis of clofentezine and chlorfenapyr in environmental water samples. Self-assembling IL-Fe3O4 MPs were used in D-μ-SPE as adsorbents. Two D-μ-SPE extraction methods, namely, direct dispersive micro-solid phase extraction (d-D-μ-SPE) and in situ solvent formation-based dispersive micro-solid phase extraction (ISF-D-μ-SPE), were proposed, using [C8MIM][PF6] to extract analytes through two pathways. Lower IL doses were required in the extraction process compared with those in other IL-based methods. Fe3O4 MPs can also be recycled and reused after extraction and are thus environmentally friendly. These newly developed methods were demonstrated to be feasible for use in the quantitation of clofentezine and chlorfenapyr at trace levels, with lower limit of detection values ranging from 0.4 to 0.5 ng mL(-1) for d-D-μ-SPE and 0.4 ng mL(-1) for ISF-D-μ-SPE. Finally, relative standard deviations of less than 6.0% were obtained.

  7. A fully spray-coated fuel cell membrane electrode assembly using Aquivion ionomer with a graphene oxide/cerium oxide interlayer

    Science.gov (United States)

    Breitwieser, Matthias; Bayer, Thomas; Büchler, Andreas; Zengerle, Roland; Lyth, Stephen M.; Thiele, Simon

    2017-05-01

    A novel multilayer membrane electrode assembly (MEA) for polymer electrolyte membrane fuel cells (PEMFCs) is fabricated in this work, within a single spray-coating device. For the first time, direct membrane deposition is used to fabricate a PEMFC by spraying the short-side-chain ionomer Aquivion directly onto the gas diffusion electrodes. The fully sprayed MEA, with an Aquivion membrane 10 μm in thickness, achieved a high power density of 1.6 W/cm2 for H2/air operation at 300 kPaabs. This is one of the highest reported values for thin composite membranes operated in H2/air atmosphere. By the means of confocal laser scanning microscopy, individual carbon fibers from the gas diffusion layer are identified to penetrate through the micro porous layer (MPL), likely causing a low electrical cell resistance in the range of 150 Ω cm2 through the thin sprayed membranes. By spraying a 200 nm graphene oxide/cerium oxide (GO/CeO2) interlayer between two layers of Aquivion ionomer, the impact of the electrical short is eliminated and the hydrogen crossover current density is reduced to about 1 mA/cm2. The peak power density of the interlayer-containing MEA drops only by 10% compared to a pure Aquivion membrane of similar thickness.

  8. Self-assembling peptide hydrogel enables instant epicardial coating of the heart with mesenchymal stromal cells for the treatment of heart failure.

    Science.gov (United States)

    Ichihara, Yuki; Kaneko, Masahiro; Yamahara, Kenichi; Koulouroudias, Marinos; Sato, Nobuhiko; Uppal, Rakesh; Yamazaki, Kenji; Saito, Satoshi; Suzuki, Ken

    2018-02-01

    Transplantation of mesenchymal stromal cells (MSCs) is an emerging therapy for the treatment of heart failure. However, the delivery method of MSC is currently suboptimal. The use of self-assembling peptide hydrogels, including PuraMatrix ® (PM; 3-D Matrix, Ltd), has been reported for clinical hemostasis and in research models. This study demonstrates the feasibility and efficacy of an advanced approach for MSC-therapy, that is coating of the epicardium with the instantly-produced PM hydrogel incorporating MSCs (epicardial PM-MSC therapy). We optimized the conditions/procedure to produce "instant" 2PM-MSC complexes. After spreading on the epicardium by easy pipetting, the PM-MSC complex promptly and stably adhere to the beating heart. Of note, this treatment achieved more extensive improvement of cardiac function, with greater initial retention and survival of donor MSCs, compared to intramyocardial MSC injection in rat heart failure models. This enhanced efficacy was underpinned by amplified myocardial upregulation of a group of tissue repair-related genes, which led to enhanced repair of the damaged myocardium, i.e. augmented microvascular formation and reduced interstitial fibrosis. These data suggest a potential for epicardial PM-MSC therapy to be a widely-adopted treatment of heart failure. This approach may also be useful for treating diseases in other organs than the heart. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Ultra-stretchable conductors based on buckled super-aligned carbon nanotube films.

    Science.gov (United States)

    Yu, Yang; Luo, Shu; Sun, Li; Wu, Yang; Jiang, Kaili; Li, Qunqing; Wang, Jiaping; Fan, Shoushan

    2015-06-14

    Ultra-stretchable conductors are fabricated by coating super-aligned carbon nanotube (SACNT) films on pre-strained polydimethylsiloxane (PDMS) substrates and forming buckled SACNT structures on PDMS after release of the pre-strain. The parallel SACNT/PDMS conductors demonstrate excellent stability with normalized resistance changes of only 4.1% under an applied strain as high as 200%. The SACNT/PDMS conductors prepared with cross-stacked SACNT films show even lower resistance variation. The parallel SACNT/PDMS conductors exhibit high durability with a resistance increase of less than 5% after 10,000 cycles at 150% strain. In situ microscopic observations demonstrate that the buckled SACNT structures are straightened during the stretching process with reversible morphology evolution and thus the continuous SACNT conductive network can be protected from fracture. Due to the excellent electrical and mechanical properties of SACNT films and the formation of the buckled structure, SACNT/PDMS films exhibit high stretchability and durability, possessing great potential for use as ultra-stretchable conductors for wearable electronics, sensors, and energy storage devices.

  10. Design and Preparation of Two ReBCO-CORC® Cable-In-Conduit Conductors for Fusion and Detector Magnets

    Science.gov (United States)

    Mulder, T.; van der Laan, D.; Weiss, J. D.; Dudarev, A.; Dhallé, M.; ten Kate, H. H. J.

    2017-12-01

    Two new ReBCO-CORC® based cable-in-conduit conductors (CICC) are developed by CERN in collaboration with ACT-Boulder. Both conductors feature a critical current of about 80 kA at 4.5 K and 12 T. One conductor is designed for operation in large detector magnets, while the other is aimed for application in fusion type magnets. The conductors use a six-around-one cable geometry with six flexible ReBCO CORC® strands twisted around a central tube. The fusion CICC is designed to be cooled by the internal forced flow of either helium gas or supercritical helium to cope with high heat loads in superconducting magnets in large fusion experimental reactors. In addition, the cable is enclosed by a stainless steel jacket to accommodate with the high level of Lorentz forces present in such magnets. Detector type magnets require stable, high-current conductors. Therefore, the detector CORC® CICC comprises an OFHC copper jacket with external conduction cooling, which is advantageous due to its simplicity. A 2.8 m long sample of each conductor is manufactured and prepared for testing in the Sultan facility at PSI Villigen. In the paper, the conductor design and assembly steps for both CORC® CICCs are highlighted.

  11. 30 CFR 57.12011 - High-potential electrical conductors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-potential electrical conductors. 57.12011... Electricity Surface and Underground § 57.12011 High-potential electrical conductors. High-potential electrical conductors shall be covered, insulated, or placed to prevent contact with low potential conductors. ...

  12. 30 CFR 56.12011 - High-potential electrical conductors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-potential electrical conductors. 56.12011... § 56.12011 High-potential electrical conductors. High-potential electrical conductors shall be covered, insulated, or placed to prevent contact with low potential conductors. ...

  13. 46 CFR 111.60-4 - Minimum cable conductor size.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Minimum cable conductor size. 111.60-4 Section 111.60-4...-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-4 Minimum cable conductor size. Each cable conductor must be #18 AWG (0.82 mm2) or larger except— (a) Each power and lighting cable conductor must be...

  14. 30 CFR 57.12080 - Bare conductor guards.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare conductor guards. 57.12080 Section 57... Underground Only § 57.12080 Bare conductor guards. Trolley wires and bare power conductors shall be guarded at... conductors are less than 7 feet above the rail, they shall be guarded at all points where persons work or...

  15. Assembly for electrical conductivity measurements in the piston cylinder device

    Science.gov (United States)

    Watson, Heather Christine [Dublin, CA; Roberts, Jeffrey James [Livermore, CA

    2012-06-05

    An assembly apparatus for measurement of electrical conductivity or other properties of a sample in a piston cylinder device wherein pressure and heat are applied to the sample by the piston cylinder device. The assembly apparatus includes a body, a first electrode in the body, the first electrode operatively connected to the sample, a first electrical conductor connected to the first electrode, a washer constructed of a hard conducting material, the washer surrounding the first electrical conductor in the body, a second electrode in the body, the second electrode operatively connected to the sample, and a second electrical conductor connected to the second electrode.

  16. Contribution of ethylenetetrafluoroethylene (ETFE) insulation to the electrical performance of Riata® silicone leads having externalized conductors.

    Science.gov (United States)

    Fischer, Avi; Klehn, Russell

    2013-08-01

    The insulation of St. Jude Medical Riata® leads contains a polytetrafluoroethylene (PTFE) liner, silicone tubing, and ethylenetetrafluoroethylene (ETFE) coating on individual cable conductors. ETFE has sufficient dielectric strength to assure electrical function. This investigation intended to analyze performance of leads with and without externalized conductors and with intact and breached ETFE. Testing was performed on ETFE-coated conductors to determine their ability to deliver high-voltage therapy. Tests were performed on samples under different conditions and current leakage was measured. A high-voltage test and a cyclic pulse test were performed, and the effect of lead modifications on the potential gradient from a high-voltage shock was used to determine functionality. Measurements from modified Riata® leads were compared with a control lead with all insulation and conducting elements intact. Current leakage for all conditions tested, was within the acceptance criteria for the high-voltage test and the cyclic pulse test. In conductors that underwent cyclic testing, the highest value of current leakage was within the limit of acceptability for both phases of the test. Testing of leads with externalized conductors and breached ETFE showed similar potential gradients compared with a control lead. Testing of ETFE-coated conductors following multiple preconditioning steps showed that ETFE serves as a redundant layer of insulation. In the event that the ETFE coating is breached, the potential gradient seen resulting from a high-voltage defibrillation shock was similar to a lead with no breach to the ETFE, even after 100 shocks.

  17. Role of self-assembly coated Er(3+): YAlO3/TiO2 in intimate coupling of visible-light-responsive photocatalysis and biodegradation reactions.

    Science.gov (United States)

    Dong, Shanshan; Dong, Shuangshi; Tian, Xiadi; Xu, Zhengxue; Ma, Dongmei; Cui, Bin; Ren, Nanqi; Rittmann, Bruce E

    2016-01-25

    Conventionally used ultraviolet light can result in dissolved organic carbon (DOC) increasing and biofilm damage in intimate coupling of photocatalysis and biodegradation (ICPB). Visible-light-responsive photocatalysis offers an alternative for achieving ICPB. In this study, composite-cubes were developed using self-assembly to coat a thin and even layer of visible-light-responsive photocatalyst (Er(3+): YAlO3/TiO2) on sponge-type carriers, followed by biofilm cultivation. The degradations of phenol (50 mg L(-1)) were compared for four protocols in circulating beds: adsorption (AD), visible-light-responsive photocatalysis (VPC), biodegradation (B), and intimately coupled visible-light-responsive photocatalysis and biodegradation (VPCB). The phenol and DOC removal efficiencies using VPCB in 16 h were 99.8% and 65.2%, respectively, i.e., higher than those achieved using VPC (71.6% and 50.0%) or B (99.4% and 58.2%). The phenol removal of 96.3% could be obtained even after 3 additional cycles. The 6.17-min intermediate detected by HPLC, continuously accumulated for VPC, appeared at 1-6 h and then was completely removed for VPCB in 10 h. ICPB was further illustrated in that most of the biofilm was protected in the carrier interiors, with less protection on the carrier exterior in VPCB. A self-regulation mechanism that helped photocatalyst exposure to visible-light irradiation was identified, promoting the combined photocatalysis and biodegradation. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Rail industry job analysis : passenger conductor.

    Science.gov (United States)

    2013-02-01

    This document describes the results of a job analysis that was conducted for the position of railroad Passenger Conductor. Key aspects of the position were identified, including main tasks and knowledge, skills, abilities, and other characteristics (...

  19. Rail industry job analysis : freight conductor.

    Science.gov (United States)

    2013-03-01

    This document describes the results from a job analysis that was conducted for the position of Freight Conductor. Key aspects of the position were identified, including main tasks and knowledge, skills, abilities, and other characteristics (KSAOs) ne...

  20. Influence of the air Layer Between the Conductor and the Layer Ofinsulating Material in Cable Products

    Directory of Open Access Journals (Sweden)

    Ivanova Evgenia V.

    2016-01-01

    Full Text Available There are developed mathematical model of physical and chemical processes of polymerization adhesive coating stranded cable. There are shown difference in the temperature distribution along the radius of the finished product in the presence of an air gap between the conductor and the rubber sheath. Also, due to the need to change process parameters with possible loose contacts inside the cable. Such as the temperature of the heating surface, feeding speed and dwell time in the oven.

  1. Low inductance power electronics assembly

    Science.gov (United States)

    Herron, Nicholas Hayden; Mann, Brooks S.; Korich, Mark D.; Chou, Cindy; Tang, David; Carlson, Douglas S.; Barry, Alan L.

    2012-10-02

    A power electronics assembly is provided. A first support member includes a first plurality of conductors. A first plurality of power switching devices are coupled to the first support member. A first capacitor is coupled to the first support member. A second support member includes a second plurality of conductors. A second plurality of power switching devices are coupled to the second support member. A second capacitor is coupled to the second support member. The first and second pluralities of conductors, the first and second pluralities of power switching devices, and the first and second capacitors are electrically connected such that the first plurality of power switching devices is connected in parallel with the first capacitor and the second capacitor and the second plurality of power switching devices is connected in parallel with the second capacitor and the first capacitor.

  2. YBCO Coated Conductor with an Integrated Optical Fiber Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sathyamurthy, Srivatsan [American Superconductor Corporation, Devens, MA (United States); Rupich, Marty [American Superconductor Corporation, Devens, MA (United States); Schwartz, Justin [North Carolina State Univ., Raleigh, NC (United States)

    2016-03-31

    The primary objectives of the Phase I Project was to develop a proof-of-principle for a concept of integrating an optical fiber sensor into the laminated 2G wire, there by producing a functionalized 2G wire with self-monitoring capabilities

  3. Effects of Conductor Baton Use on Band and Choral Musicians' Perceptions of Conductor Expressivity and Clarity

    Science.gov (United States)

    Nápoles, Jessica; Silvey, Brian A.

    2017-01-01

    The purpose of this study was to examine participants' (college band and choral musicians, N = 143) perceptions of conductor clarity and expressivity after viewing band and choral directors conducting with or without a baton. One band and one choral conductor each prepared and conducted two excerpts of Guy Forbes's "O Nata Lux", a piece…

  4. The Optical Links of the ATLAS SemiConductor Tracker

    CERN Document Server

    Abdesselam, A; Apsimon, R; Band, C; Barr, C; Batchelor, L; Bates, R; Bell, P; Bernabeu, J; Bizzell, J; Brenner, R; Brodbeck, T; Bruckman De Renstrom, P; Buttar, C; Carter, J; Charlton, D; Cheplakov, A; Chilingarov, A; Chu, M-L; Colijn, A-P; Dawson, I; Demirkõz, B; de Jong, P; Dervan, P; Dolezal, Z; Dowell, J; Escobar, P; Spencer, E; Ekelöf, T J C; Eklund, L; Ferrere, D; Fraser, T; French, M; French, R; Fuster, J; Gallop, B; García, C; Goodrick, M; Greenall, A; Grillo, A; Grosse-Knetter, J; Hartjes, F; Hessey, N; Hill, J C; Homer, J; Hou, L; Hughes, G; Ikegami, Y; Issever, C; Jackson, J; Jones, M; Jones, T J; Jovanovic, P; Koffeman, E; Kodys, P; Kohriki, T; Lee, S-C; Lester, C; Limper, M; Lindsay, S W; Lozano, M; Macwaters, C; Magrath, C; Mahout, G; Mandic, I; Matheson, J; McMahon, T; Mikulec, B; Muijs, A; Morrissey, M; Nichols, A; Nickerson, R; O'Shea, V; Pagenis, S; Parker, M; Pater, J; Perrin, E; Pernegger, H; Peeters, S; Phillips, P; Postranecky, M; Robinson, D; Robson, A; Rudge, A; Sandaker, H; Sedlak, K; Smith, N A; Stapnes, S; Stugu, B; Teng, P K; Terada, S; Tricoli, A; Tyndel, M; Ujiie, N; Ullán, M; Unno, Y; van der Kraaij, E; Van Vulpen, I; Viehhauser, G; Vossebeld, J H; Warren, M; Wastie, R; Weidberg, A; Wells, P; White, D; Wilson, J

    2007-01-01

    Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical link requirements are reviewed, with particular emphasis on the very demanding environment at the LHC. The on-detector components have to operate in high radiation levels for 10 years, with no maintenance, and there are very strict requirements on power consumption, material and space. A novel concept for the packaging of the on-detector optoelectronics has been developed to meet these requirements. The system architecture, including its redundancy features, is explained and the critical on-detector components are described. The results of the extensive Quality Assurance performed during all steps of the assembly are discussed. Optical links are used for the readout of the 4088 silicon microstrip modules that make up the SemiConductor Tracker of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The optical ...

  5. A One-Step Rapid Assembly of Thin Film Coating Using Green Coordination Complexes for Enhanced Removal of Trace Organic Contaminants by Membranes.

    Science.gov (United States)

    Guo, Hao; Yao, Zhikan; Yang, Zhe; Ma, Xiaohua; Wang, Jianqiang; Tang, Chuyang Y

    2017-11-07

    We report a fast, simple, and green coating method using the coordination complex of tannic acid (TA) and ferric ion (Fe3+) to enhance the removal of trace organic contaminants (TrOCs) by polyamide membranes. The entire coating process can be completed in less than 2 min; quartz crystal microbalance characterization revealed that a TA-Fe thin film formed in merely 10-20 s. Coating this TA-Fe thin film on a commercial nanofiltration membrane (NF270) reduced its effective pore size from 0.44 to 0.40 nm. The TA-Fe-coated NF270 showed significantly increased rejection of both NaCl and trace organic contaminants. In comparison with the more-time-consuming polydopamine coating (e.g., 0.5 h), the TA-Fe coating presented greater resistance to TrOC permeation (i.e., lower permeability of TrOCs). The advantages of the fast coating process, greatly improved rejection performance, and use of green accessible materials make TA-Fe a highly promising coating material for large-scale applications.

  6. A sturdy self-cleaning and anti-corrosion superhydrophobic coating assembled by amino silicon oil modifying potassium titanate whisker-silica particles

    Science.gov (United States)

    Lv, Chongjiang; Wang, Huaiyuan; Liu, Zhanjian; Zhang, Wenbo; Wang, Chijia; Tao, Ruifeng; Li, Meiling; Zhu, Yanji

    2018-03-01

    A sturdy self-cleaning and anticorrosion superhydrophobic coating based on poly(phenylene sulfide) (PPS) matrix has been successfully fabricated by combination of sol-gel and spraying technology without using any fluorine materials. The prepared coating possessed excellent superhydrophobicity with the water contact angle (WCA) (161 ± 1.2)° and slide angle (SA) (2 ± 1.5)°, which was ascribed to the synergistic effect of low-surface energy material amino silicon oil (ASO) and the binary potassium titanate whisker-silica (PTW-SiO2) composite particles formed by in-situ growth of SiO2 on modified PTW via sol-gel. Moreover, The PPS/ASO/PTW-SiO2 superhydrophobic coating exhibited decent self-cleaning property with clean surface even after 100 times immersion in muddy solution. The abrasion test demonstrated that the mechanical stability of prepared coating was about 2 times of the pure PPS coating. Simultaneously, the potentiodynamic polarization and electrochemical impedance spectroscopy testified the excellent corrosion resistance of prepared coating with the performance of lower corrosion current (1.289 × 10-10 A/cm2) and high protection efficiency (99.999%) even after immersion in 3.5 wt.% NaCl solution for 28 days. It is believed that this sturdy self-cleaning and anti-corrosion superhydrophobic coating might have a promising application prospect in industry.

  7. Frequency Dependent Losses in Transmission Cable Conductors

    DEFF Research Database (Denmark)

    Olsen, Rasmus Schmidt; Holbøll, Joachim; Guðmundsdóttir, Unnur Stella

    2011-01-01

    and economical gain, such severe network changes necessitate correct estimation and optimisation of load conditions in the cable grid. Both IEC and IEEE have published standards for rating transmission cables' current carrying capacity. These standards are based on assumptions of a number of parameters......, such as thermal conditions in and around the cable, as well as the heat generated in conductors, screens, armours etc., taking into account proximity and skin effects. The work performed and presented in this paper is concerned with an improved determination of the losses generated in the conductor, by means...... of better calculation of the AC resistance of transmission cable conductors, in particular regarding higher frequencies. In this way, also losses under harmonics can be covered. Furthermore, the model is suitable for modelling of transient attenuation in high voltage cables. The AC resistance is calculated...

  8. Properties and applications of perovskite proton conductors

    Directory of Open Access Journals (Sweden)

    Eduardo Caetano Camilo de Souza

    2010-09-01

    Full Text Available A brief overview is given of the main types and principles of solid-state proton conductors with perovskite structure. Their properties are summarized in terms of the defect chemistry, proton transport and chemical stability. A good understanding of these subjects allows the manufacturing of compounds with the desired electrical properties, for application in renewable and sustainable energy devices. A few trends and highlights of the scientific advances are given for some classes of protonic conductors. Recent results and future prospect about these compounds are also evaluated. The high proton conductivity of barium cerate and zirconate based electrolytes lately reported in the literature has taken these compounds to a highlight position among the most studied conductor ceramic materials.

  9. Tunable Broadband Printed Carbon Transparent Conductor

    Science.gov (United States)

    Xu, Yue; Wan, Jiayu

    Transparent conductors have been widely applied in solar cells, transparent smart skins, and sensing/imaging antennas, etc. Carbon-based transparent conductor has attracted great attention for its low cost and broad range transparency. Ion intercalation has been known to highly dope graphitic materials, thereby tuning materials' optoelectronic properties. For the first time, we successfully tune the optical transmittance of a reduced graphene oxide (RGO)/CNT network from mid-IR range to visible range by means of Li-ion intercalation/deintercalation. We also observed a simultaneous increase of the electrical conductivity with the Li-ion intercalation. This printed carbon hybrid thin film was prepared through all solution processes and was easily scalable. This study demonstrates the possibility of using ion intercalation for low cost, tunable broadband transparent conductors.

  10. On Resistance and Inductance of Solid Conductors

    Directory of Open Access Journals (Sweden)

    Oldřich Coufal

    2013-01-01

    Full Text Available The concepts of resistance and inductance are strewn with misunderstanding and errors that result from inaccurate terminology, mistakes in their definitions, and from the fact that they are quantities that characterize elements of ideal electrical circuits as well as real solid conductors. This is shown unfavourably not only in the respective field of the theory of electrical engineering, but also in the calculation of resistance and inductance. In this paper, a brief theoretical analysis of the state of the art is given, and its results are applied in the calculation of the current density, resistance, and inductance of two coaxial solid tubular conductors.

  11. Measuring the Magnetic Force on a Current-Carrying Conductor.

    Science.gov (United States)

    Herreman, W.; Huysentruyt, R.

    1995-01-01

    Describes a fast and simple method for measuring the magnetic force acting on a current-carrying conductor using a digital balance. Discusses the influence of current intensity and wire length on the magnetic force on the conductor. (JRH)

  12. Evaluation of the effect of expansion and shear stress on a self-assembled endothelium mimicking nanomatrix coating for drug eluting stents in vitro and in vivo.

    Science.gov (United States)

    Andukuri, Adinarayana; Min, IlJae; Hwang, Patrick; Alexander, Grant; Marshall, Lauren E; Berry, Joel L; Wick, Timothy M; Joung, Yoon Ki; Yoon, Young-Sup; Brott, Brigitta C; Han, Dong Keun; Jun, Ho-Wook

    2014-09-01

    Coating stability is increasingly recognized as a concern impacting the long-term effectiveness of drug eluting stents (DES). In particular, unstable coatings have been brought into focus by a recently published report (Denardo et al 2012 J. Am. Med. Assoc. 307 2148-50). Towards the goal of overcoming current challenges of DES performance, we have developed an endothelium mimicking nanomatrix coating composed of peptide amphiphiles that promote endothelialization, but limit smooth muscle cell proliferation and platelet adhesion. Here, we report a novel water evaporation based method to uniformly coat the endothelium mimicking nanomatrix onto stents using a rotational coating technique, thereby eliminating residual chemicals and organic solvents, and allowing easy application to even bioabsorbable stents. Furthermore, the stability of the endothelium mimicking nanomatrix was analyzed after force experienced during expansion and shear stress under simulated physiological conditions. Results demonstrate uniformity and structural integrity of the nanomatrix coating. Preliminary animal studies in a rabbit model showed no flaking or peeling, and limited neointimal formation or restenosis. Therefore, it has the potential to improve the clinical performance of DES by providing multifunctional endothelium mimicking characteristics with structural integrity on stent surfaces.

  13. Fabrication and assembly of BOLVAPS (boil-off lithium vapor source) ceramic-option half anodes

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.H.; Appel, D.B.; Cap, J.S.; Spiak, S.H. (Sandia National Labs., Albuquerque, NM (USA)); Cason, B.P.J. (General Electric Co., Largo, FL (USA). Materials and Processes Unit)

    1990-06-01

    In order to generate a lithium vapor on the anode surface within PBFA II, an electrically insulating, lithium-coated substrate is required. One approach for providing this lithium source is the ceramic-option anode. This anode consists of two halves, equatorially split, each containing an insulating ceramic insert onto which a lithium-bearing film is sputtered. A lithium vapor is generated by ohmically pulse heating this film to 1500 K. The half-anode structure required to produce this vapor consists of a ceramic insulator, steel housing, and disk conductors. This report describes the design and fabrication of these separate components and the procedures required to join them to form the half-anode assembly. In addition, appendices are included which contain detailed drawings and specifications for these operations. 5 refs., 10 figs.

  14. 46 CFR 183.372 - Equipment and conductor grounding.

    Science.gov (United States)

    2010-10-01

    ... insulated grounding conductor of a cable must be identified by one of the following means: (1) A green braid or green insulation; (2) Stripping the insulation from the entire exposed length of the grounding conductor; or (3) Marking the exposed insulation of the grounding conductor with green tape or green...

  15. 33 CFR 159.71 - Electrical controls and conductors.

    Science.gov (United States)

    2010-07-01

    ... Electrical controls and conductors. Electrical controls and conductors must be installed in accordance with good marine practice. Wire must be copper and must be stranded. Electrical controls and conductors must... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Electrical controls and...

  16. 30 CFR 77.503 - Electric conductors; capacity and insulation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric conductors; capacity and insulation... UNDERGROUND COAL MINES Electrical Equipment-General § 77.503 Electric conductors; capacity and insulation. Electric conductors shall be sufficient in size and have adequate current carrying capacity and be of such...

  17. 30 CFR 75.513 - Electric conductor; capacity and insulation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric conductor; capacity and insulation. 75... MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.513 Electric conductor; capacity and insulation. All electric conductors shall be sufficient in...

  18. 21 CFR 868.1920 - Esophageal stethoscope with electrical conductors.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Esophageal stethoscope with electrical conductors... stethoscope with electrical conductors. (a) Identification. An esophageal stethoscope with electrical conductors is a device that is inserted into the esophagus to listen to a patient's heart and breath sounds...

  19. 30 CFR 57.12048 - Communication conductors on power poles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Communication conductors on power poles. 57... MINES Electricity Surface and Underground § 57.12048 Communication conductors on power poles. Telegraph, telephone, or signal wires shall not be installed on the same crossarm with power conductors. When carried...

  20. 30 CFR 56.12048 - Communication conductors on power poles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Communication conductors on power poles. 56... Electricity § 56.12048 Communication conductors on power poles. Telegraph, telephone, or signal wires shall not be installed on the same crossarm with power conductors. When carried on poles supporting...

  1. The Conductor as Servant-Leader.

    Science.gov (United States)

    Wis, Ramona M.

    2002-01-01

    Focuses on how conductors can gain leadership skills. Discusses the process of becoming a leader, beginning with developing a personal philosophy. Describes the differences between leadership and management, a specific approach to leadership called the servant-leader, and the characteristics of a servant-leader. Includes a bibliography of…

  2. Impedance Calculations of Induction Machine Rotor Conductors ...

    African Journals Online (AJOL)

    The exact calculation of the impedance of induction machine rotor conductors at several operating frequencies are necessary if the dynamic behaviour of the machine is to give a good correlation between the simulated starting torque and current and the experimental results. This paper describes a method of' calculating ...

  3. Random matrix model for disordered conductors

    Indian Academy of Sciences (India)

    1. Introduction. Matrix models are being successfully employed in a variety of domains of physics includ- ing studies on heavy nuclei [1], mesoscopic disordered conductors [2,3], two-dimensional quantum gravity [4], and chaotic quantum systems [5]. Universal conductance fluctuations in metals [6] and spectral fluctuations in ...

  4. Random matrix model for disordered conductors

    Indian Academy of Sciences (India)

    Keywords. Disordered conductors; random matrix theory; Dyson's Coulomb gas model. ... An interesting random walk problem associated with the joint probability distribution of the ensuing ensemble is discussed and its connection with level dynamics is brought out. It is further proved that Dyson's Coulomb gas analogy ...

  5. Functional Carbon Nanotubes for Electrical Conductors

    Science.gov (United States)

    Schauerman, Christopher Mark

    Carbon nanotube (CNT) conductors are an enabling technology for advancing the efficacy of sustainable energy systems. In parallel, proactive consideration for each of the phases in the material life cycle can enhance device performance while minimizing unwanted impacts. Increasing the yield of CNTs through advances in synthesis will help reduce the electricity, chemicals, and costs associated with their production. Modifications to the nanoscale morphology (alignment, bundling, density and lower contact resistances) are needed to improve the CNT material properties to meet or exceed those of conventional metallic conductors. Also, a robust evaluation of methods for contacting carbon-based wires is needed when interfacing with metallic contacts. Finally, it's important to begin looking at upstream options for proper treatment of waste streams containing CNT conductors when they reach the end of their useable life. Therefore, the subject of this dissertation focuses on the development of functional CNT conductors and considers approaches to improve each phase of their life cycle. Specifically, progress towards using more efficient catalysts in the laser vaporization process has led to a 50% increase in SWCNT yield and simplified the purification procedure. The use of chemical dopants such as KAuCl4 has increased the electrical conductivity up to 1x10 6 S/m which is over an order of magnitude higher than the pre-doping baseline value. Alternatively, chlorosulfonic acid was used to disperse high weight loadings of SWCNTs and modify the nanoscale morphology through the use of selective coagulation and mechanical extrusions of binder free SWCNT wires. The highly dense and aligned wires have electrical conductivities as high as 4.9x106 S/m and are in agreement with the highest CNT conductivities reported. The ability to contact bulk CNT conductors through ultrasonic welding was demonstrated for the first time and exhibit low carbon-copper contact resistances of 4.3 mO-cm2

  6. Synthesis and self-assembly of large-area Cu nanosheets and their application as an aqueous conductive ink on flexible electronics.

    Science.gov (United States)

    Dang, Rui; Song, Lingling; Dong, Wenjun; Li, Chaorong; Zhang, Xiaobo; Wang, Ge; Chen, Xiaobo

    2014-01-08

    Large-area Cu nanosheets are synthesized by a strategy of Cu nanocrystal self-assembly, and then aqueous conductive Cu nanosheet ink is successfully prepared for direct writing on the conductive circuits of flexible electronics. The Cu nanocrystals, as building blocks, self-assemble along the [111] direction and grow into large-area nanosheets approximately 30-100 μm in diameter and a few hundred nanometers in thickness. The laminar stackable patterns of the Cu nanosheet circuits increase the contact area of the Cu nanosheets and improve the stability of the conductor under stress, the result being that the Cu nanosheet circuits display excellent conductive performance during repeated folding and unfolding. Moreover, heterostructures of Ag nanoparticle-coated Cu nanosheets are created to improve the thermal stability of the nanosheet circuits at high temperatures.

  7. Size-Dependent Rupture Strain of Elastically Stretchable Metal Conductors

    Science.gov (United States)

    Graudejus, O.; Jia, Z.; Li, T.; Wagner, S.

    2012-01-01

    Experiments show that the rupture strain of gold conductors on elastomers decreases as the conductors are made long and narrow. Rupture is caused by the irreversible coalescence of microcracks into one long crack. A mechanics model identifies a critical crack length ℓcr, above which the long crack propagates across the entire conductor width. ℓcr depends on the fracture toughness of the gold film and the width of the conductor. The model provides guidance for the design of highly stretchable conductors. PMID:22773917

  8. Enhanced Transmission through the Nanoparticle Coat

    Energy Technology Data Exchange (ETDEWEB)

    Song, G; Yu, L; Liu, B; Li, T, E-mail: candlesinwind@gmail.com [School of Science, Beijing University of Posts and Telecommunications, Beijing, 100876 (China)

    2011-02-01

    By using the full-vectorial three-dimensional finite-difference time-domain method and the perfect electronic conductor as the materials, we studied the enhanced transmission spectra through a substrate with the perfect electronic conductor nanoparticle coat. Single metal nanoparticle exhibited characteristic localized surface plasmon modes. By placing more plasmonic nanoparticles close to each other to make up of a plane, it was possible to observe the interaction between the modes of each individual nanostructure. The results showed that the enhanced transmission spectra through a substrate with different nanoparticle coats which were made by different numbers of the layers or by different metals exhibited different peaks whose values could reach 1. The number of the nanoparticle coat layers influenced the number and the positions of the enhanced transmission peaks.

  9. The Astro-H high temperature superconductor lead assemblies

    Science.gov (United States)

    Canavan, E. R.; James, B. L.; Hait, T. P.; Oliver, A.; Sullivan, D. F.

    2014-11-01

    The Soft X-ray Spectrometer (SXS) instrument, one of several instruments on JAXA's Astro-H mission, will observe diffuse X-ray sources with unparalleled spectral resolution using a microcalorimeter array operating at 50 mK. The array is cooled with a multi-stage Adiabatic Demagnetization Refrigerator mounted on a 40 l helium tank. The tank is at the center of a typical 'shell in shell' cryostat, with the innermost shield cooled by a JT cryocooler, and successive outer shields cooled by stirling-cycle cryocoolers. To achieve a multi-year liquid helium lifetime and to avoid exceeding the limited capacity of the JT cooler, very strict requirements are placed on every source of heat leak into these surfaces from the higher temperature shields. However, each ADR stage draws a maximum of 2 A, and the Wiedemann-Franz Law precludes even an optimized set of normal-metal leads capable of such high current from achieving the required low thermal conductance. Instead, a set of lead assemblies have been developed based on narrow high temperature superconductor (HTS) tapes derived from commercially available coated conductors. Although the HTS tapes are flexible and have high tensile strength, they are extremely sensitive to damage through a number of mechanisms. A robust set of assemblies have been developed that provide mechanical support to the tapes, provide appropriate interfaces at either end, and yet still meet the challenging thermal requirements. An Engineering Model (EM) set of HTS lead assemblies have survived environmental testing, both as individual units and as part of the EM cryostat, and have performed without problem in recent operation of the EM instrument. The Flight Model (FM) HTS lead assemblies are currently nearing completion.

  10. Benchmarking organic mixed conductors for transistors

    KAUST Repository

    Inal, Sahika

    2017-11-20

    Organic mixed conductors have garnered significant attention in applications from bioelectronics to energy storage/generation. Their implementation in organic transistors has led to enhanced biosensing, neuromorphic function, and specialized circuits. While a narrow class of conducting polymers continues to excel in these new applications, materials design efforts have accelerated as researchers target new functionality, processability, and improved performance/stability. Materials for organic electrochemical transistors (OECTs) require both efficient electronic transport and facile ion injection in order to sustain high capacity. In this work, we show that the product of the electronic mobility and volumetric charge storage capacity (µC*) is the materials/system figure of merit; we use this framework to benchmark and compare the steady-state OECT performance of ten previously reported materials. This product can be independently verified and decoupled to guide materials design and processing. OECTs can therefore be used as a tool for understanding and designing new organic mixed conductors.

  11. AA, inner conductor of a magnetic horn

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    At the start-up of the AA and during its initial operation, magnetic horns focused the antiprotons emanating from the production target. These "current-sheet lenses" had a thin inner conductor (for minimum absorption of antiprotons), machined from aluminium to wall thicknesses of 0.7 or 1 mm. The half-sine pulses rose to 150 kA in 8 microsec. The angular acceptance was 50 mrad.

  12. Los conductores re-examinados: El transcurso del tiempo deteriora significativamente los conocimientos de los conductores

    Directory of Open Access Journals (Sweden)

    Francisco J. Martos

    2012-01-01

    Full Text Available Dos mil cinco conductores, 1204 hombres y 801 mujeres, una muestra representativa de la población española de conductores, fueron nuevamente examinados utilizando un cuestionario que reproducía fielmente un examen de conducir realizado por la Dirección General de Tráfico (DGT. Las preguntas fueron clasificadas en"“muy importantes", "importantes" y "poco importantes". El 96.5 % de los conductores, suspendió el examen. Los resultados eran tanto peores cuanto más tiempo había transcurridodesde la obtención del permiso de conducir. Esto era independiente de la importancia de las preguntas, de la mayor o menor frecuencia de conducción y afectaba por igual a hombres y mujeres. Las mujeres obtienen mejores puntuaciones en señalización mientras que los hombres son mejores en las preguntas de seguridad vial. Los resultados también demostraban que los conductores profesionales y los de mayor nivel educativo sufren un menor deterioro. Tales resultados nos llevan a considerar la relación que estos datos puedan tener en los niveles de accidentalidad y la conveniencia de establecer pautas para la actualización del conocimiento de los conductores. Finalmente, se discute la relevancia que el examen que se utiliza para obtener el permiso de conducir tiene como indicador o predictor de una futura conducción segura.

  13. Testing of the 3M Company Composite Conductor

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, John P [ORNL; Rizy, D Tom [ORNL; Kisner, Roger A [ORNL

    2010-10-01

    The 3M Company has developed a high-temperature low-sag conductor referred to as Aluminum-Conductor Composite-Reinforced or ACCR. The conductor uses an aluminum metal matrix material to replace the steel in conventional conductors. The objective of this work is to accelerate the commercial acceptance by electric utilities of this new conductor design by testing four representative conductor classes in controlled conditions. A unique facility called the Powerline Conductor Accelerated Testing (PCAT) Facility was built at ORNL for testing overhead conductors. The PCAT has been uniquely designed for testing overhead bare transmission line conductors at high currents and temperatures after they have been installed and tensioned to the manufacturer's specifications. The ability to operate a transmission line conductor in this manner does not exist elsewhere in the United States. Four classes of ACCR cable designed by the 3M Company have been successfully test at ORNL small, medium, large and small/compact. Based on these and other manufacturer tests, the 3M Company has successfully introduced the ACCR into the commercial market and has completed over twenty installations for utility companies.

  14. Dye-sensitized Solar Cells: New Approaches with Organic Solid-state Hole Conductors.

    Science.gov (United States)

    Vlachopoulos, Nick; Zhang, Jinbao; Hagfeldt, Anders

    2015-02-25

    Solid-state dye-sensitized solar cells (sDSCs) in which a solid organic charge-transfer medium, or hole conductor (HC), is interposed between a dye-coated mesoporous oxide electrode and a conductive counter electrode, have attracted considerable interest as viable alternatives to the more ubiquitous mediator-electrolyte DSC. Of particular importance to efficient operation are, in addition to the useful processes contributing to current generation (light harvesting, electron injection and current collection), the recombinative deleterious processes. The organic HCs are highly reactive toward electrons in the oxide or the conducting glass support, therefore necessitating the inclusion of a carefully prepared thin blocking oxide underlayer support as well as the molecular design of special dark current-suppressing dyes. Initially (mid-1990s) sDSCs with organic small molecular weight hole conductors have undergone systematic investigation. At the same time the first tests of sDSCs with conducting polymer hole conductors were published, with subsequent emphasis on the in situ generation of the HC inside the pores. For both types of devices a light-to-electricity conversion efficiency, in the 5-10% range for several dye-HC combinations, approaches that of the most efficient DSCs with non-volatile liquid electrolytes, thereby encouraging further efforts for obtaining stable, efficient and inexpensive sDSCs.

  15. New Development in the Preparation of Micro/Nano-Wires of Molecular (Magnetic Conductors

    Directory of Open Access Journals (Sweden)

    Lydie Valade

    2010-03-01

    Full Text Available A lot of molecular (magnetic conductors are prepared largely using charge-transfer (CT salts of donor molecules with acceptor molecules or nonmagnetic or magnetic anions such as metal halides and oxides; their CT salts are usually obtained as bulk crystals, which are used to elucidate the electrical conducting (magnetic properties. In contrast, a small number of micro/nano-crystals of the molecular (magnetic conductors, especially micro/nano-wires, are known, of which highly conducting nanowires are necessary as a key component in the development of the next generation of nano-size transistors and spin-transistors. Very recently, we succeeded in preparing highly conductive micro/nano-wires of CT salts between bent donor molecules developed by one of the author’s group and magnetic FeX4– (X = Cl, Br ions: (1 by electrochemical oxidation of the bent donor molecules with a silicon wafer electrode coated with a phospholipid multi-lamellar structure as well as, (ii by electrochemical oxidation of the bent donor molecules with a large arc structure, in the presence of NBu4FeX4 supporting electrolytes. This article reviews template-free and template-assisted methods developed so far for the preparation of micro/nano-wires of molecular (magnetic conductors along with our new methods. The conducting properties of these micro/nano-wires are compared with those of the corresponding bulk crystals.

  16. Simulated nuclear reactor fuel assembly

    Science.gov (United States)

    Berta, Victor T.

    1993-01-01

    An apparatus for electrically simulating a nuclear reactor fuel assembly. It includes a heater assembly having a top end and a bottom end and a plurality of concentric heater tubes having electrical circuitry connected to a power source, and radially spaced from each other. An outer target tube and an inner target tube is concentric with the heater tubes and with each other, and the outer target tube surrounds and is radially spaced from the heater tubes. The inner target tube is surrounded by and radially spaced from the heater tubes and outer target tube. The top of the assembly is generally open to allow for the electrical power connection to the heater tubes, and the bottom of the assembly includes means for completing the electrical circuitry in the heater tubes to provide electrical resistance heating to simulate the power profile in a nuclear reactor. The embedded conductor elements in each heater tube is split into two halves for a substantial portion of its length and provided with electrical isolation such that each half of the conductor is joined at one end and is not joined at the other end.

  17. Advances in Thick Film Conductors for Microwave Integrated Circuits

    OpenAIRE

    Wilson, Larry K.; Rich, Debbie D.; Rich, Phil W.; R. Wayne Johnson

    1980-01-01

    New conductor pastes have made possible great improvements in the loss characteristics of thick film microwave integrated circuits. This paper presents data on the microwave characteristics of transmission structures made from newly developed copper, silver and gold conductor pastes on alumina and garnet substrates. The resistivity and microstructure for each conductor material was examined for correlation with microwave properties. These data show that thick film circuits can give excellent ...

  18. New joints for 'old' LYNX conductor

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, R.

    1988-03-01

    Tension joints (and anchor clamps) are used on overhead line aluminium conductors, steel reinforced (a.c.s.r.). For satisfactory performance and long term reliability, thorough preparation of the conductors prior to jointing is essential. This is relatively easy with new conductors but the preparation of conductors which have been in service for several years is difficult and time consuming. This article outlines an alternative method of preparing 175 sq. mm a.c.s. r.(LYNX) which is easier and quicker but still effective.

  19. First qualification of ITER Toroidal Field Coil conductor jacketing

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Kazuya, E-mail: hamada.kazuya@jaea.go.jp [Japan Atomic Energy Agency (Japan); Takahashi, Yoshikazu; Isono, Takaaki; Nunoya, Yoshihiko; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Koizumi, Norikiyo; Nakajima, Hideo; Okuno, Kiyoshi [Japan Atomic Energy Agency (Japan); Matsuda, Hidemitsu; Yano, Yoshitaka [Nippon Steel Engineering Co. Ltd (Japan); Devred, Arnauld; Bessette, Denis [ITER Organization (France)

    2011-10-15

    The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field Coil conductors as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is a circular shaped, cable-in-conduit conductor, composed of a cable and a stainless steel conduit (jacket). The outer diameter and maximum length of the TF conductor are 43.7 mm and 760 m, respectively. JAEA started to produce strand, cables and jacket sections and to construct a conductor manufacturing (jacketing) facility in 2008. Following preparation in December 2009 of the jacketing facility, the dummy cable, the jacket sections and fabrication procedures, such as welding, cable insertion, compaction and spooling, JAEA manufactured a 760 m long Cu dummy conductor for process qualification. Into the 760 m long Cu dummy conductor jacketing, JAEA successfully inserted the cable with a maximum force of 32 kN. The outer diameter of the cross section of the spooled conductor was 43.7 {+-} 0.15 mm, which complies with the ITER target requirement of 43.7 {+-} 0.3 mm. Following qualification of all manufacturing processes, JAEA has started to fabricate superconducting conductors for the TF coils.

  20. Mechanically flexible and multifunctional polymer-based graphene foams for elastic conductors and oil-water separators.

    Science.gov (United States)

    Wu, Chao; Huang, Xingyi; Wu, Xinfeng; Qian, Rong; Jiang, Pingkai

    2013-10-18

    We present a novel strategy for the fabrication of ordered and flexible polymer-based graphene foams by self-assembly of graphene sheets on a 3D polymer skeleton. The obtained graphene foams show excellent mechanical, electrical, and hydrophobic properties, thus holding great potential as elastic conductors and oil-water separators. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. AA, Inner Conductor of Magnetic Horn

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    Antiprotons emerging at large angles from the production target (hit by an intense 26 GeV proton beam from the PS), were focused into the acceptance of the injection line of the AA by means of a "magnetic horn" (current-sheet lens). Here we see an early protype of the horn's inner conductor, machined from solid aluminium to a thickness of less than 1 mm. The 1st version had to withstand pulses of 150 kA, 15 us long, every 2.4 s. See 8801040 for a later version.

  2. High Temperature Protonic Conductors by Melt Growth

    Science.gov (United States)

    2006-11-21

    electrolyzers, solid state fuel cells, gas separation membranes, moisture sensors and high-density energy storage applications, among others (1-5...A.R. de Arellano-López, A. Sayir. “Microestructura y Comportamiento Plástico de Perovsquitas Conductoras Protónicas de Alta Temperatura ”. Bol. Soc...Conductores Protónicos de Alta Temperatura Crecidos por Fusión de Zona Flotante”. VII Reunión Nacional y VI Conferencia Iberoamericana (Electrocerámica

  3. Flat conductor cable for electrical packaging

    Science.gov (United States)

    Angele, W.

    1972-01-01

    Flat conductor cable (FCC) is relatively new, highly promising means for electrical packaging and system integration. FCC offers numerous desirable traits (weight, volume and cost savings, flexibility, high reliability, predictable and repeatable electrical characteristics) which make it extremely attractive as a packaging medium. FCC, today, finds wide application in everything from integration of lunar equipment to the packaging of electronics in nuclear submarines. Described are cable construction and means of termination, applicable specifications and standards, and total FCC systems. A list of additional sources of data is also included for more intensive study.

  4. The construction of the ATLAS semi-conductor tracker

    Science.gov (United States)

    Jones, Tim

    2006-12-01

    The ATLAS (A Toroidal LHC ApparatuS) experiment at the Large Hadron Collider (LHC) at CERN has been designed to explore physics at the TeV energy scale and will be commissioned in 2007. In the innermost region of the experiment is a charged particle tracker, the Inner Detector of which the Semiconductor Tracker (SCT) is a major component. The SCT comprises a central barrel section enclosed by two endcaps (A and C). The construction of the major components of the ATLAS Semi-conductor tracker (SCT) is now nearing completion. Following a brief description of the design of the SCT, the logistics and organisation of the construction phase of the project are discussed. Central to the delivery of a high quality detector is the testing of large numbers of modules both during assembly and after they are mounted on their final support structures. The results of these tests for endcap C are presented showing that the electrical performance of the 988 modules to be installed in ATLAS is compatible with the specifications required.

  5. 30 CFR 56.12010 - Isolation or insulation of communication conductors.

    Science.gov (United States)

    2010-07-01

    ... conductors. 56.12010 Section 56.12010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... MINES Electricity § 56.12010 Isolation or insulation of communication conductors. Telephone and low... energized power conductors or any other power source. ...

  6. PREFACE: International Symposium on Molecular Conductors: Novel Functions of Molecular Conductors under Extreme Conditions (ISMC 2008)

    Science.gov (United States)

    Takahashi, Toshihiro; Suzumura, Yoshikazu

    2008-02-01

    The International Symposium on Molecular Conductors 2008 (ISMC2008) was held as the second international symposium of the project entitled `Novel Functions of Molecular Conductors under Extreme Conditions', which was supported by the Grant-in-aid for Scientific Research on Priority Areas from the Ministry of Education, Culture, Sports, Science and Technology in Japan. The project lasted from September 2003 to March 2008, and was completed by this symposium held at Okazaki Conference Center, Institute for Molecular Science, Okazaki, Japan (23-25 July 2008), which about 100 scientists attended. During the symposium, five project teams gave summary talks and exciting talks were given on the topics developed recently not only by the members of the project but also by other scientists including invited speakers from abroad, who are doing active research on molecular conductors. It is expected that papers presented in the symposium will give valuable hints for the next step in the research of this field. Therefore the organizers of this symposium decided to publish this proceedings in order to demonstrate these activities, not only for the local community of the project, but also for the broad society of international scientists who are interested in molecular conductors. The editors, who are also the organizers of this symposium, believe that this proceedings provides a significant and relevant contribution to the field of molecular conductors since it is the first time we have published such a proceedings as an electronic journal. We note that all papers published in this volume of Journal of Physics: Conference Series have been peer reviewed by expert referees. Editors made every effort to satisfy the criterion of a proceedings journal published by IOP Publishing. Toshihiro Takahashi and Yoshikazu Suzumura Editors: Toshihiro Takahashi (Gakushuin University) (Chairman) Kazushi Kanoda (University of Tokyo) Seiichi Kagoshima (University of Tokyo) Takehiko Mori (Tokyo

  7. Dual-layered nanogel-coated hollow lipid/polypeptide conjugate assemblies for potential pH-triggered intracellular drug release.

    Directory of Open Access Journals (Sweden)

    Wen-Hsuan Chiang

    Full Text Available To achieve effective intracellular anticancer drug delivery, the polymeric vesicles supplemented with the pH-responsive outlayered gels as a delivery system of doxorubicin (DOX were developed from self-assembly of the lipid/polypeptide adduct, distearin grafted poly(γ-glutamic acid (poly(γ-GA, followed by sequential deposition of chitosan and poly(γ-GA-co-γ-glutamyl oxysuccinimide-g-monomethoxy poly(ethylene glycol in combination with in situ covalent cross-linking on assembly surfaces. The resultant gel-caged polymeric vesicles (GCPVs showed superior performance in regulating drug release in response to the external pH change. Under typical physiological conditions (pH 7.4 and 37 °C at which the γ-GA/DOX ionic pairings remained mostly undisturbed, the dense outlayered gels of GCPVs significantly reduced the premature leakage of the uncomplexed payload. With the environmental pH being reduced from pH 7.4 to 4.7, the drug liberation was appreciably promoted by the massive disruption of the ionic γ-GA/DOX complexes along with the significant swelling of nanogel layers upon the increased protonation of chitosan chain segments. After being internalized by HeLa cells via endocytosis, GCPVs exhibited cytotoxic effect comparable to free DOX achieved by rapidly releasing the payload in intracellular acidic endosomes and lysosomes. This strongly implies the great promise of such unique GCPVs as an intracellular drug delivery carrier for potential anticancer treatment.

  8. Testing of the 3M Company ACCR Conductor

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, J.P.; RIzy, D.T.; Kisner, R.A.; Deve, H.E. (3M Comp.)

    2010-09-15

    The 3M Company has developed a high-temperature low-sag conductor referred to as Aluminum- Conductor Composite-Reinforced or ACCR. The conductor uses an aluminum metal matrix material to replace the steel in conventional conductors so the core has a lower density and higher conductivity. The objective of this work is to accelerate the commercial acceptance by electric utilities of these new conductor designs by testing four representative conductor classes in controlled conditions. Overhead transmission lines use bare aluminum conductor strands wrapped around a steel core strands to transmit electricity. The typical cable is referred to as aluminum-conductor steel-reinforced (ACSR). The outer strands are aluminum, chosen for its conductivity, low weight, and low cost. The center strand is of steel for the strength required to support the weight without stretching the aluminum due to its ductility. The power density of a transmission corridor has been directly increased by increasing the voltage level. Transmission voltages have increased from 115-kV to 765- kV over the past 80 years. In the United States, further increasing the voltage level is not feasible at this point in time, so in order to further increase the power density of a transmission corridor, conductor designs that increase the current carrying capability have been examined. One of the key limiting factors in the design of a transmission line is the conductor sag which determines the clearance of the conductor above ground or underlying structures needed for electrical safety. Increasing the current carrying capability of a conductor increases the joule heating in the conductor which increases the conductor sag. A conductor designed for high-temperature and lowsag operation requires an engineered modification of the conductor materials. To make an advanced cable, the 3M Company solution has been the development of a composite conductor consisting of Nextel ceramic fibers to replace the steel core and

  9. Conductor gestures influence evaluations of ensemble performance.

    Science.gov (United States)

    Morrison, Steven J; Price, Harry E; Smedley, Eric M; Meals, Cory D

    2014-01-01

    Previous research has found that listener evaluations of ensemble performances vary depending on the expressivity of the conductor's gestures, even when performances are otherwise identical. It was the purpose of the present study to test whether this effect of visual information was evident in the evaluation of specific aspects of ensemble performance: articulation and dynamics. We constructed a set of 32 music performances that combined auditory and visual information and were designed to feature a high degree of contrast along one of two target characteristics: articulation and dynamics. We paired each of four music excerpts recorded by a chamber ensemble in both a high- and low-contrast condition with video of four conductors demonstrating high- and low-contrast gesture specifically appropriate to either articulation or dynamics. Using one of two equivalent test forms, college music majors and non-majors (N = 285) viewed sixteen 30 s performances and evaluated the quality of the ensemble's articulation, dynamics, technique, and tempo along with overall expressivity. Results showed significantly higher evaluations for performances featuring high rather than low conducting expressivity regardless of the ensemble's performance quality. Evaluations for both articulation and dynamics were strongly and positively correlated with evaluations of overall ensemble expressivity.

  10. Phthalocyanine Conductors : New Trend for Crystal and Functionality Design

    OpenAIRE

    Inabe, Tamotsu; Ishikawa, Manabu; Asari, Takehiro; Hasegawa, Hiroyuki; Fujita, Akiko; Matsumura, Naoko; Naito, Toshio; Matsuda, Masaki; Tajima, Hiroyuki

    2006-01-01

    Conductors obtained from axially substituted phthalocyanine units are presented. In contrast to face-to-face one-dimensional stacking in conductors with planar phthalocyanins, various types of π−π stacking structures can be obtained owing to the slipped stacking.

  11. Beyond the Beat: Modelling Intentions in a Virtual Conductor

    NARCIS (Netherlands)

    ter Maat, Mark; Ebbers, Rob M.; Reidsma, Dennis; Nijholt, Antinus

    We describe our research on designing and implementing a Virtual Conductor. That is, a virtual human (embodied agent) that acts like a human conductor in its interaction with a real, human orchestra. We reported previously on a first version that used a digital musical score to lead an orchestra.

  12. The Effect of Intentional, Preplanned Movement on Novice Conductors' Gesture

    Science.gov (United States)

    Bodnar, Erin N.

    2017-01-01

    Preplanning movement may be one way to broaden novice conductors' vocabulary of gesture and promote motor awareness. To test the difference between guided score study and guided score study with preplanned, intentional movement on the conducting gestures of novice conductors, undergraduate music education students (N = 20) were assigned to one of…

  13. 46 CFR 120.372 - Equipment and conductor grounding.

    Science.gov (United States)

    2010-10-01

    ... conductor with green tape or green adhesive labels. (e) Cable armor must not be used to ground electrical... specified by the Commandant. (d) Each insulated grounding conductor of a cable must be identified by one of the following means. (1) A green braid or green insulation; (2) Stripping the insulation from the...

  14. Results of conductor testing in SULTAN a review

    CERN Document Server

    Wesche, R; Bruzzone, P; Calvi, M; Cau, F; Herzog, R; Marinucci, C; Stepanov, B

    2009-01-01

    In the last few years, the DC performance of a large number of sub- and full-size NbTi as well as Nb3Sn cablein- conduit (CIC) conductors was tested in the SULTAN facility of CRPP. The “potential” DC performance of various CIC conductors was estimated from the measured strand data. In the present work, the DC performance of CIC conductors, measured in SULTAN, is compared with this “potential” DC performance. The DC performance of NbTi sub- and full size CIC conductors has been found to be in good agreement with the “potential” conductor performance. For Nb3Sn CIC conductors, the situation is more complex because of the strain sensitivity of the critical current. Evidence for strand damage, caused by the large Lorentz forces, has been found in Nb3Sn subsize conductors. Finally, a summary of the results of the tests of the ITER-TF Nb3Sn conductors is provided. Again the measured DC performance is compared to the "potential" performance.

  15. Non-equilibrium and band tailing in organic conductors

    Indian Academy of Sciences (India)

    Band tailing; organic conductors; IR spectra; electrical resistivity. Abstract. The concept of band tailing with focal point and width of the tail from IR absorption spectra of different organic conductors is found valid even for thermal and elastic changes. The experimental situations like change of solvents, method of preparation, ...

  16. 46 CFR 111.50-3 - Protection of conductors.

    Science.gov (United States)

    2010-10-01

    ... of overcurrent protection for conductors is to open the electric circuit if the current reaches a... 46 Shipping 4 2010-10-01 2010-10-01 false Protection of conductors. 111.50-3 Section 111.50-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS...

  17. Professional Orchestral Conductors' Use of Selected Teaching Behaviors in Rehearsal

    Science.gov (United States)

    Whitaker, Jennifer A.

    2017-01-01

    This descriptive study examined professional conductors' use of rehearsal time in sequential pattern components, discussing task presentation targets, and using verbal imagery and modeling techniques. Commercially available videos of 15 professional conductors rehearsing prominent orchestras were scripted, coded, and timed for selected teaching…

  18. Fault-induced conductor motions on distribution lines

    Energy Technology Data Exchange (ETDEWEB)

    Lu, M.L.; Zhang, M.; Luk, H.C.; Chopra, N. [BC Hydro, Burnaby, BC (Canada)

    2010-07-01

    Reclosers are used in power distribution systems to improve the reliability of power supply by isolating any fault area in a distribution line while keeping the rest of the line alive. However, the fault induced conductor motion could cause conductor slapping so that a greater fault could result on the live part of the line, forcing a whole line outage. Some of the recent outages on BC Hydro (BCH) distribution systems are assumed to be attributed to this cause. A breaker lockout event occurred on BCH McLellan 25F42 feeder in November 2009 in Langley, British Columbia. This paper presented a novel approach to predicting the fault conductor motion. The method was validated by checking against limited test data available in the literature and was used to analyze the McLellan event, in order to confirm the hypothesis that the conductor slapping was the cause of the breaker lockout. The paper presented a schematic of the idea of a recloser for line protection against a fault and illustrated the motions of the two parallel conductors due to the fault current. The proposed model for predicting fault-induced conductor motion was then described and validated. The case study of the BCH McLellan 25F42 feeder was presented. The breaker lockout event of was confirmed to be caused by conductor slapping as a result of the fault-induced conductor motion. 7 refs., 2 tabs., 7 figs.

  19. Elastically stretchable thin film conductors on an elastomeric substrate

    Science.gov (United States)

    Jones Harris, Joyelle Elizabeth

    Imagine a large, flat screen television that can be rolled into a small cylinder after purchase in the store and then unrolled and mounted onto the wall of a home. The electronic devices within the television must be able to withstand large deformation and tensile strain. Consider a robot that is covered with an electronic skin that simulates human skin. The skin would enable the machine to lift an elderly person with care and sensitivity. The skin will endure repeated deformation with the highest tensile strains being experienced at the robot's joints. These applications and many others will benefit from stretchable electronic circuitry. While several different methods have been employed to create stretchable electronics, all methods use a common tool -- stretchable conductors. Therefore, the goal of this thesis work was to fabricate elastically stretchable conductors that can be used in stretchable electronics. We deposited Au thin films on an elastomeric substrate, and the resulting conductors remained electrically continuous when stretched by 30% and more. We developed photolithographic processes that can be used to pattern elastically stretchable conductors with a 10 mum resolution. We fabricated bi-level stretchable conductors that are separated by an elastomeric insulator and are electrically connected through via holes in the insulator. We applied our bi-level conductors to create a stretchable resistor-inductor-capacitor (RLC) circuit with a tunable resonant frequency. We also used stretchable conductors to measure action potentials in biological samples. This thesis describes the fabrication and application of our elastically stretchable conductors.

  20. Order and orientation control of mesoporous silica films on conducting gold substrates formed by dip-coating and self-assembly: a grazing angle of incidence small-angle X-ray scattering and field emission scanning electron microscopy study.

    Science.gov (United States)

    Tate, Michael P; Eggiman, Brian W; Kowalski, Jonathan D; Hillhouse, Hugh W

    2005-10-25

    Grazing-angle of incidence small-angle X-ray scattering (GISAXS) and high-resolution field emission scanning electron microscopy have been used to characterize the mesophase symmetry, orientation, and long-range order in PEO20-PPO70-PEO20 (Pluronic P123) templated mesoporous silica thin films on conducting gold substrates as a function of silica-to-ethylene oxide (Si/EO) block ratio and relative humidity (RH). The films are formed by dip-coating followed by evaporation-induced self-assembly under tightly controlled RH. The general evolution of the mesophase follows the trends that are expected based on shape factors due to swelling of the PEO block. However, changes in orientation of the nanostructure relative to the substrate and the degree of long-range order are found to depend on Si/EO ratio. These effects are likely due to the dynamics of evaporation and self-assembly. Generally, at Si/EO ratios lower than 3.29, the films contained regions where the nanostructure was not oriented relative to the plane of the substrate. However, for Si/EO ratios greater than 3.62, conditions were found where the nanostructure of the film was highly oriented relative to the plane of the substrate. This is true over the range of RH studied, independent of the nanostructure symmetry. For low Si/EO ratios at the highest RH levels, the films were composed of a mixture of spherical and cylindrical pores. At high Si/EO ratios and high RH levels, the films had a highly oriented R-3m nanostructure but displayed streaking perpendicular to the substrate in the Bragg spots on GISAXS patterns. This streaking is interpreted as faulting along planes parallel to the substrate.

  1. Three-dimensional highly conductive graphene-silver nanowire hybrid foams for flexible and stretchable conductors.

    Science.gov (United States)

    Wu, Chao; Fang, Lijun; Huang, Xingyi; Jiang, Pingkai

    2014-12-10

    Graphene foams have showed huge application potentials owing to their unique 3D structure and superior properties. Thus, it is highly desired to develop a simple and effective pathway to fabricate high performance graphene-based foams. Here, we present a polymer template-assisted assembly strategy for fabricating a novel class of graphene/AgNW hybrid foams. The hybrid foams show 3D ordered microstructures, high thermal stability, and excellent electrical and mechanical properties, and demonstrate huge application potential in the fields of flexible and stretchable conductors. Importantly, the polymer-template assisted assembly technique is simple, scalable, and low-cost, providing a new synthesis protocol for various multifunctional graphene hybrid foam-based composites.

  2. ELECTRODYNAMIC STABILITY COMPUTATIONS FOR FLEXIBLE CONDUCTORS OF THE AERIAL LINES

    Directory of Open Access Journals (Sweden)

    I. I. Sergey

    2015-01-01

    Full Text Available In aerial transmission lines aluminium multiwire conductors are in use. Owing to their flexible design the electrodynamic effect of short circuit currents may lead to intolerable mutual rendezvous and even cross-whipping of the phase conductors. The increasing motion of the conductors caused by effect of the short-circuit electrodynamic force impulse is accompanied by the dynamic load impact affecting the conductors, insulating and supporting constructions of the aerial lines. Intensity of the short-circuit currents electrodynamic impact on the flexible conductors depends on the short circuit current magnitude. For research into electrodynamic endurance of the conductors of the aerial lines located at the vertices of arbitrary triangle with spans of a large length, the authors assume the conductor analytical model in the form of a flexible tensile thread whose mass is distributed evenly lengthwise the conductor. With this analytical model, by the action of the imposed forces the conductor assumes the form conditioned by the diagram of applied external forces, and resists neither bending nor torsion. The initial conditions calculation task reduces to solving the flexible thread statics equations. The law of motion of the conductor marginal points comes out of the conjoint solution of dynamic equations of the conductor and structural components of the areal electric power lines. Based on the proposed algorithm, the researchers of the Chair of the Electric Power Stations of BNTU developed a software program LINEDYS+, which in its characteristics yields to no foreign analogs, e. g. SAMSEF. To calculate the initial conditions they modified a software program computing the flexible conductor mechanics named MR 21. The conductor short-circuit electrodynamic interaction estimation considers structural elements of the areal lines, ice and wind loads, objective parameters of the short circuit. The software programs are accommodated with the simple and

  3. Edge effect enhanced electron field emission in top assembled reduced graphene oxide assisted by amorphous CNT-coated carbon cloth substrate

    Directory of Open Access Journals (Sweden)

    Rajarshi Roy

    2013-01-01

    Full Text Available In this work a hybrid structure assembly of amorphous carbon nanotubes (a-CNTs -reduced graphene oxide (RGO has been fabricated on carbon cloth/PET substrates for enhanced edge effect assisted flexible field emission device application. The carbon nanostructures prepared by chemical processes were finally deposited one over the other by a simple electrophoretic deposition (EPD method on carbon cloth (CC fabric. The thin films were then characterized by X-ray diffraction (XRD, Fourier transformed infrared spectroscopy (FTIR, field emission scanning electron microscopy (FESEM and high resolution transmission electron microscope (HRTEM. Field assisted electron emission measurement was performed on this hybrid structure. It was observed that the hybrid carbon nanostructure showed exceptional field emission properties with outstanding low turn-on and threshold field (Eto∼ 0.26 Vμm−1, Eth ∼ 0.55 Vμm1. These observed results are far better compared to standalone and plasma etched edge enhanced RGO systems due to the bottom layer a-CNTs bed which assisted in significant enhancement of edge effect in RGO sheets.

  4. Plasmonics with two-dimensional conductors

    Science.gov (United States)

    Yoon, Hosang; Yeung, Kitty Y. M.; Kim, Philip; Ham, Donhee

    2014-01-01

    A wealth of effort in photonics has been dedicated to the study and engineering of surface plasmonic waves in the skin of three-dimensional bulk metals, owing largely to their trait of subwavelength confinement. Plasmonic waves in two-dimensional conductors, such as semiconductor heterojunction and graphene, contrast the surface plasmonic waves on bulk metals, as the former emerge at gigahertz to terahertz and infrared frequencies well below the photonics regime and can exhibit far stronger subwavelength confinement. This review elucidates the machinery behind the unique behaviours of the two-dimensional plasmonic waves and discusses how they can be engineered to create ultra-subwavelength plasmonic circuits and metamaterials for infrared and gigahertz to terahertz integrated electronics. PMID:24567472

  5. Lithium battery electrodes with ultra-thin alumina coatings

    Science.gov (United States)

    Se-Hee, Lee; George, Steven M.; Cavanagh, Andrew S.; Yoon Seok, Jung; Dillon, Anne C.

    2015-11-24

    Electrodes for lithium batteries are coated via an atomic layer deposition process. The coatings can be applied to the assembled electrodes, or in some cases to particles of electrode material prior to assembling the particles into an electrode. The coatings can be as thin as 2 .ANG.ngstroms thick. The coating provides for a stable electrode. Batteries containing the electrodes tend to exhibit high cycling capacities.

  6. Metal-driven hierarchical self-assembled zigzag nanoarchitectures with electrical conductivity.

    Science.gov (United States)

    Qiao, Yan; Lin, Yiyang; Liu, Song; Zhang, Shaofei; Chen, Huanfa; Wang, Yijie; Yan, Yun; Guo, Xuefeng; Huang, Jianbin

    2013-01-25

    Quasi-one-dimensional electroactive materials with zigzag shape are fabricated by supramolecular self-assembly of a tetrathiafulvalene (TTF) derivative and metal ions under mild conditions. This is the first time that self-assembled organic conductors with zigzag shape are reported.

  7. Nonequilibrium fluctuation relations in a quantum coherent conductor.

    Science.gov (United States)

    Nakamura, Shuji; Yamauchi, Yoshiaki; Hashisaka, Masayuki; Chida, Kensaku; Kobayashi, Kensuke; Ono, Teruo; Leturcq, Renaud; Ensslin, Klaus; Saito, Keiji; Utsumi, Yasuhiro; Gossard, Arthur C

    2010-02-26

    We experimentally demonstrate the validity of nonequilibrium fluctuation relations by using a quantum coherent conductor. In equilibrium the fluctuation-dissipation relation leads to the correlation between current and current noise at the conductor, namely, the Johnson-Nyquist relation. When the conductor is voltage biased so that the nonlinear regime is entered, the fluctuation theorem has predicted similar nonequilibrium fluctuation relations, which hold true even when the Onsager-Casmir relations are broken in magnetic fields. Our experiments qualitatively validate the predictions as the first evidence of this theorem in the nonequilibrium quantum regime.

  8. Recent progress in high-pressure studies on organic conductors

    Directory of Open Access Journals (Sweden)

    Syuma Yasuzuka and Keizo Murata

    2009-01-01

    Full Text Available Recent high-pressure studies of organic conductors and superconductors are reviewed. The discovery of the highest Tc superconductivity among organics under high pressure has triggered the further progress of the high-pressure research. Owing to this finding, various organic conductors with the strong electron correlation were investigated under high pressures. This review includes the pressure techniques using the cubic anvil apparatus, as well as high-pressure studies of the organic conductors up to 10 GPa showing extraordinary temperature and pressure dependent transport phenomena.

  9. High-field conductor testing at the FENIX facility

    Science.gov (United States)

    Shen, S. S.; Chaplin, M. R.; Felker, B.; Hassenzahl, W. V.; Kishiyama, K. I.; Parker, J. M.

    1993-04-01

    The Fusion Engineering International experiments (FENIX) Test Facility, which was commissioned at the end of 1991, is the first facility in the world capable of testing prototype conductors for the International Thermonuclear Experimental Reactor (ITER) superconducting magnets. The FENIX facility provides test conditions that simulate the ITER magnet operating environment; more importantly, it also accommodates specific experiments to determine the operational margins for the prototype conductors. The FENIX facility generates magnetic fields close to 14 T, and transport currents over 40 kA for testing the prototype conductors. This paper describes an experimental program that measures critical currents, current-sharing temperatures, forced-flow properties, and cyclic effects.

  10. 30 CFR 56.12005 - Protection of power conductors from mobile equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of power conductors from mobile... MINES Electricity § 56.12005 Protection of power conductors from mobile equipment. Mobile equipment shall not run over power conductors, nor shall loads be dragged over power conductors, unless the...

  11. Development of Stable, Low Resistance Solder Joints for a Space-Flight HTS Lead Assemblies

    Science.gov (United States)

    Canavan, Edgar R.; Chiao, Meng; Panashchenko, Lyudmyla; Sampson, Michael

    2017-01-01

    The solder joints in spaceflight high temperature superconductor (HTS) lead assemblies for certain astrophysics missions have strict constraints on size and power dissipation. In addition, the joints must tolerate years of storage at room temperature, many thermal cycles, and several vibration tests between their manufacture and their final operation on orbit. As reported previously, solder joints between REBCO coated conductors and normal metal traces for the Astro-H mission showed low temperature joint resistance that grew approximately as log time over the course of months. Although the assemblies worked without issue in orbit, for the upcoming X-ray Astrophysics Recovery Mission we are attempting to improve our solder process to give lower, more stable, and more consistent joint resistance. We produce numerous sample joints and measure time- and thermal cycle-dependent resistance, and characterize the joints using x-ray and other analysis tools. For a subset of the joints, we use SEMEDS to try to understand the physical and chemical processes that effect joint behavior.

  12. Kinetic regulation of coated vesicle secretion

    CERN Document Server

    Foret, Lionel

    2008-01-01

    The secretion of vesicles for intracellular transport often rely on the aggregation of specialized membrane-bound proteins into a coat able to curve cell membranes. The nucleation and growth of a protein coat is a kinetic process that competes with the energy-consuming turnover of coat components between the membrane and the cytosol. We propose a generic kinetic description of coat assembly and the formation of coated vesicles, and discuss its implication to the dynamics of COP vesicles that traffic within the Golgi and with the Endoplasmic Reticulum. We show that stationary coats of fixed area emerge from the competition between coat growth and the recycling of coat components, in a fashion resembling the treadmilling of cytoskeletal filaments. We further show that the turnover of coat components allows for a highly sensitive switching mechanism between a quiescent and a vesicle producing membrane, upon a slowing down of the exchange kinetics. We claim that the existence of this switching behaviour, also tri...

  13. Origin of fast ion diffusion in super-ionic conductors

    Science.gov (United States)

    He, Xingfeng; Zhu, Yizhou; Mo, Yifei

    2017-06-01

    Super-ionic conductor materials have great potential to enable novel technologies in energy storage and conversion. However, it is not yet understood why only a few materials can deliver exceptionally higher ionic conductivity than typical solids or how one can design fast ion conductors following simple principles. Using ab initio modelling, here we show that fast diffusion in super-ionic conductors does not occur through isolated ion hopping as is typical in solids, but instead proceeds through concerted migrations of multiple ions with low energy barriers. Furthermore, we elucidate that the low energy barriers of the concerted ionic diffusion are a result of unique mobile ion configurations and strong mobile ion interactions in super-ionic conductors. Our results provide a general framework and universal strategy to design solid materials with fast ionic diffusion.

  14. High voltage switches having one or more floating conductor layers

    Science.gov (United States)

    Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

    2015-11-24

    This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

  15. Electric and Magnetic Forces between Parallel-Wire Conductors.

    Science.gov (United States)

    Morton, N.

    1979-01-01

    Discusses electric and magnetic forces between parallel-wire conductors and derives, in a simple fashion, order of magnitude estimates of the ratio of the likely electrostatic and electromagnetic forces for a simple parallel-wire balance. (Author/HM)

  16. Organic Conductors: Evidence for Correlation Effects in Infrared Properties

    DEFF Research Database (Denmark)

    Jacobsen, Claus Schelde; Johannsen, Ib; Bechgaard, Klaus

    1984-01-01

    The infrared conductivities of four organic conductors with partially filled one-electron bands are compared. The behavior ranges from near Drude type in the best metal to semiconductorlike in the moderate conductor. Electron-molecular-vibration coupling effects of varying degree are seen in all...... materials. It is suggested that the combined effect of electron-electron interaction and electron-phonon interaction in producing 4kF charge-density waves is essential for interpreting the results....

  17. Novel Highly Conductive and Transparent Graphene-Based Conductors

    OpenAIRE

    Khrapach, Ivan; Withers, Freddie; Bointon, Thomas H.; Polyushkin, Dmitry K.; Barnes, William L.; Russo, Saverio; Craciun, Monica F.

    2012-01-01

    Future wearable electronics, displays and photovoltaic devices rely on highly conductive, transparent and yet mechanically flexible materials. Nowadays indium tin oxide (ITO) is the most wide spread transparent conductor in optoelectronic applications, however the mechanical rigidity of this material limits its use for future flexible devices. Here we report novel transparent conductors based on few layer graphene (FLG) intercalated with ferric chloride (FeCl3) with an outstandingly high elec...

  18. A new cable-in-conduit conductor magnet with insulated strands

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Satarou; Yamamoto, Junya; Motojima, Osamu

    1995-09-01

    Many studies have used cable-in-conduit conductor (CICC) coils in trying to develop an AC superconducting magnet because of its enormous potential if AC losses were low and insulation voltage was high. The strands in the most recent CICC magnets are coated with chromium or another metal with high electrical resistance to order to induce current re-distribution among the strands and to avoid a quench caused by a current imbalance. Current re-distribution is highly complex and very difficult to analyze because the conditions of the strand surfaces and the contact areas vary greatly with the operation of the conductor. If, however, the cable currents were well-balanced, insulating the strands would be the best way to reduce AC losses. We propose a new CICC magnet structure featuring a current lead that balances the strand currents via its resistance. Having calculated current balances, we find that strand currents are well within the present parameters for nuclear fusion experiments and superconducting magnet energy storages. (author).

  19. On electromagnetic induction in electric conductors

    CERN Document Server

    Korolev, Alexander I

    2013-01-01

    Experimental validation of the Faraday's law of electromagnetic induction (EMI) is performed when an electromotive force is generated in thin copper turns, located inside a large magnetic coil. It has been established that the electromotive force (emf) value should be dependent not only on changes of the magnetic induction flux through a turn and on symmetry of its crossing by magnetic power lines also. The law of EMI is applicable in sufficient approximation in case of the changes of the magnetic field near the turn are symmetrical. Experimental study of the induced emf in arcs and a direct section of the conductor placed into the variable field has been carried out. Linear dependence of the induced emf on the length of the arc has been ascertained in case of the magnetic field distribution symmetry about it. Influence of the magnetic field symmetry on the induced emf in the arc has been observed. The curve of the induced emf in the direct section over period of current pulse is similar to this one for the t...

  20. The ATLAS SemiConductorTracker

    CERN Document Server

    Mikuz, M

    2004-01-01

    The ATLAS SemiConductor Tracker (SCT) is presented. About 16000 silicon micro-strip sensors with a total active surface of over 60 m /sup 2/ and with 6.3 million read-out channels are built into 4088 modules arranged into four barrel layers and nine disks covering each of the forward regions up to an eta of 2.5. Challenges are imposed by the hostile radiation environment with particle fluences up to 2*10 /sup 14/ cm/sup -2/ 1 MeV neutron NIEL equivalent and 100 kGy TID, the 25 ns LHC bunch crossing time and the need for a hermetic, lightweight tracker. The solution adopted is carefully designed strip detectors operated at -7 degrees C, biased up to 500 V and read out by binary rad-hard fast BiCMOS electronics. A zero-CTE carbon fibre structure provides mechanical support. 30 kW of power are supplied on aluminium/Kapton tapes and cooled by C/sub 3/F/sub 8/ evaporative cooling. Data and commands are transferred by optical links. Prototypes of detector modules have been built, irradiated to the maximum expected ...

  1. Theory of Dirac Electrons in Organic Conductors

    Directory of Open Access Journals (Sweden)

    Akito Kobayashi

    2012-04-01

    Full Text Available The dynamical property of electrons with the tilted Dirac cone was examined using the tilted Weyl equation. The polarization function exhibits cusps and nonmonotonic structures by varying both the frequency and the momentum. A pair of tilted Dirac cones exhibits a new plasmon for the intermediate magnitude of momentum owing to the combined effects of two tilted cones. Dirac electrons with the zero-gap state (ZGS in organic conductor α-(BEDT-TTF2I3 are examined by calculating the Berry curvature, which displays the peak structure for a pair of Dirac particles between the conduction band and the valence band. The ZGS is theoretically predicted for α-(BEDT-TTF2NH4Hg(SCN4 under uniaxial pressure. Examining the band structure of the stripe charge ordered state of α-(BEDT-TTF2I3 under pressure, we have found a topological transition from a conventional insulator to a new phase of a pair of Dirac electrons with a finite mass. Further, investigating the zero-energy (N = 0 Landau level under a strong magnetic field, we propose ferromagnetism breaking the SU(2 valley-pseudo-spin symmetry, and the phase fluctuations of the order parameters leading to Kosterlitz-Thouless transition at lower temperatures.

  2. Ionomigration of neutral phases in ionic conductors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I. Wei; Li, Ju [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA (United States); Kim, Seung-Wan [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA (United States); Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kang, Suk-Joong L. [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Huang, Fuqiang [State Key Laboratory of High Performance, Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai (China)

    2012-11-15

    Without sensing any physical force, a neutral object in an ion conducting solid can move in a uniform electrochemical field by coupling a global ion wind with localized counterion diffusion at the interface. This happens to pores and gas bubbles at 840 C in a fast O{sup 2-} conductor, yttria-stabilized zirconia (YSZ), despite having cations that are essentially frozen with lattice diffusivities 10{sup 12} times slower than the O{sup 2-} diffusivity. Through-thickness migration and massive electro-sintering in thin YSZ ceramics are observed at voltages similar to those in YSZ fuel cells and electrolysis cells. This effect should apply to any electrochemically-loaded multiphase ionic conducting solid, with or without an electric field, and can lead to electrolyte sintering, phase accumulation and electrode debonding, resulting in unexpected benefit or damage in electrochemical devices. As the velocity obeys a pseudo Stokes-Einstein equation, inversely proportional to the object size, an especially enhanced size effect is expected in nanocomposites. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Metal{Polymer Hybrid Materials For Flexible Transparent Conductors

    Science.gov (United States)

    Narayanan, Sudarshan

    The field of organic electronics, till recently a mere research topic, is currently making rapid strides and tremendous progress into entering the mainstream electronics industry with several applications and products such as OLED televisions, curved displays, wearable devices, flexible solar cells, etc. already having been commercialized. A major component in these devices, especially for photovoltaic applications, is a transparent conductor used as one of the electrodes, which in most commercial applications are highly doped wide bandgap semiconducting oxides also called Transparent Conducting Oxides (TCOs). However, TCOs exhibit inherent disadvantages such as limited supply, brittle mechanical properties, expensive processing that present major barriers for the more widespread economic use in applications such as exible transparent conductors, owing to which suitable alternative materials are being sought. In this context we present two approaches in realizing alternative TCs using metal-polymer hybrid materials, with high figures of merit that are easily processable, reasonably inexpensive and mechanically robust as well. In this context, our first approach employs laminated metal-polymer photonic bandgap structures to effectively tune optical and electrical properties by an appropriate design of the material stack, factoring in the effect of the materials involved, the number of layers and layer properties. We have found that in the case of a four-bilayer Au/polystyrene (AujPS) laminate structure, an enhancement in optical transmittance of ˜ 500% in comparison to a monolithic A film of equivalent thickness, can be achieved. The high conductivity (˜ 106 O--1cm--1) of the metallic component, Au in this case, also ensures planar conductivity; metallic inclusions in the dielectric polymer layer can in principle give rise to out-of-plane conductivity as well enabling a fully functional TC. Such materials also have immense potential for several other applications

  4. Application of mixed-organic-cation for high performance hole-conductor-free perovskite solar cells.

    Science.gov (United States)

    Xiao, Meng; Zhao, Li; Wei, Shoubin; Li, Yanyan; Dong, Binghai; Xu, Zuxun; Wan, Li; Wang, Shimin

    2018-01-15

    ABX 3 -type organic lead halide perovskites have gained increasing attention as light harvester for solar cells due to their high power conversion efficiency (PCE). Recently, it has become a trend to avoid the use of expensive hole-transport materials (HTMs) and precious metals, such as Au, to be competitive in future commercial development. In this study, we fabricated mixed-cation perovskite-based solar cells through one-step spin-coating using methylammonium (CH 3 NH 3 + ) and formamidinium (HN=CHNH 3 + ) cations to extend the optical absorption range into the red region and enhance the utilization of solar light. The synthesized hole-conductor-free cells with carbon electrode and mixed cations exhibited increased short-circuit current, outperforming the cells prepared with pure methylammonium, and PCE of 10.55%. This paper proposes an efficient approach for fabricating high-performance and low-cost perovskite solar cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Nanostructured ionic conductors: A study of Vycor 7930-LiI composites

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Stephanie [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, Equipe Physicochimie des Materiaux Desordonnes et Poreux, Universite Montpellier 2, CC 1503, Place E. Bataillon, F-34095 Montpellier Cedex 5 (France)], E-mail: albert@emse.fr; Frolet, Nathalie [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, Equipe Physicochimie des Materiaux Desordonnes et Poreux, Universite Montpellier 2, CC 1503, Place E. Bataillon, F-34095 Montpellier Cedex 5 (France)], E-mail: nathalie.frolet@lpmc.univ-montp2.fr; Yot, Pascal G. [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, Equipe Physicochimie des Materiaux Desordonnes et Poreux, Universite Montpellier 2, CC 1503, Place E. Bataillon, F-34095 Montpellier Cedex 5 (France)], E-mail: pascal.yot@univ-montp2.fr; Pradel, Annie [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, Equipe Physicochimie des Materiaux Desordonnes et Poreux, Universite Montpellier 2, CC 1503, Place E. Bataillon, F-34095 Montpellier Cedex 5 (France)], E-mail: apradel@lpmc.univ-montp2.fr; Ribes, Michel [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2-ENSCM-UM1, Equipe Physicochimie des Materiaux Desordonnes et Poreux, Universite Montpellier 2, CC 1503, Place E. Bataillon, F-34095 Montpellier Cedex 5 (France)], E-mail: mribes@lpmc.univ-montp2.fr

    2008-05-25

    A series of three Vycor glass/LiI composites were prepared by impregnating molten LiI into a porous Vycor 7930 powdered glass. X-ray diffraction showed the presence of LiI and LiI, H{sub 2}O crystallites of about 100 nm in size. Scanning electron microscopy confirmed that an optimisation of heat treatment could lead to a composite with optimal coating and filling of the pores of the matrix. An increase in the pore size, unavoidable and due to the residual water content of the Vycor, was measured by Hg porosimetry. Nevertheless the conductivity of the composites was increased compared to that of pure LiI, with a gain of two orders of magnitude for the best conductor, i.e. 0.5LiI-0.5Vycor.

  6. Self-assembled nanogaps for molecular electronics

    DEFF Research Database (Denmark)

    Tang, Qingxin; Tong, Yanhong; Jain, Titoo

    2009-01-01

    A nanogap for molecular devices was realized using solution-based self-assembly. Gold nanorods were assembled to gold nanoparticle-coated conducting SnO2:Sb nanowires via thiol end-capped oligo(phenylenevinylene)s (OPVs). The molecular gap was easily created by the rigid molecule itself during self...

  7. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

    2009-01-01

    Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies...... and plays an important role in processing the information generated by these methods. Here, we provide a comprehensive overview of the current publicly available sequence assembly programs. We describe the basic principles of computational assembly along with the main concerns, such as repetitive sequences...... in genomic DNA, highly expressed genes and alternative transcripts in EST sequences. We summarize existing comparisons of different assemblers and provide a detailed descriptions and directions for download of assembly programs at: http://genome.ku.dk/resources/assembly/methods.html....

  8. Nanostructured coatings for super hydrophobic textiles

    Indian Academy of Sciences (India)

    A detailed study on nanosilica and clay based nanocomposite coatings using dip coating and layer by layer self assembly (L–b–L) is being described where lotus leaf effect has been mimicked on the cotton fabric surface using these particles as they develop nanosized surface roughness which helps to produce a ...

  9. Numerical modeling of heating and current-sharing effects on I-V curves of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} and MgB{sub 2} conductors

    Energy Technology Data Exchange (ETDEWEB)

    Majoros, M.; Campbell, A.M.; Glowacki, B.A.; Tomov, R.I

    2004-01-15

    Numerical modeling of heating and current-sharing effects on I-V curves of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} coated conductors and MgB{sub 2} wires was performed using finite element method software. The simulations were made when the conductors carried an over-critical current in steady-state conditions in zero applied magnetic field. Power law current-voltage characteristics typical of the real materials were used. It was assumed that the Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} coated conductors were immersed in liquid nitrogen and MgB{sub 2} wires in a liquid helium bath. It was found that a bare MgB{sub 2} wire starts to be unstable already at applied electric fields >1 {mu}V/cm. Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} coated conductor was found to be much more stable, up to applied electric fields {>=}10{sup 4} {mu}V/cm and it can carry an over-critical current {approx}1.4I{sub c}.

  10. Design of force-cooled conductors for large fusion magnets

    Energy Technology Data Exchange (ETDEWEB)

    Dresner, L.; Lue, J.W.

    1977-01-01

    Conductors cooled by supercritical helium in forced convection are under active consideration for large toroidal fusion magnets. One of the central problems in designing such force cooled conductors is to maintain an adequate stability margin while keeping the pumping power tolerably low. A method has been developed for minimizing the pumping power for fixed stability by optimally choosing the matrix-to-superconductor and the metal-to-helium ratios. Such optimized conductors reduce pumping power requirements for fusion size magnets to acceptable limits. Furthermore, the mass flow and hence pumping losses can be varied through a magnet according to the local magnetic field and magnitude of desired stability margin. Force cooled conductors give flexibility in operation, permitting, for example, higher fields to be obtained than originally intended by lowering the bath temperature or increasing the pumping power or both. This flexibility is only available if the pumping power is low to begin with. Scaling laws for the pumping requirement and stability margin as functions of operating current density, number of strands and such physical parameters as stabilizer resistivity and critical current density, have been proved. Numerical examples will be given for design of conductors intended for use in large toroidal fusion magnet systems.

  11. The Silicon Microstrip Sensors of the ATLAS SemiConductor Tracker

    CERN Document Server

    Ahmad, A; Allport, P P; Alonso, J; Andricek, L; Apsimon, R J; Barr, A J; Bates, R L; Beck, G A; Bell, P J; Belymam, A; Benes, J; Berg, C M; Bernabeu, J; Bethke, S; Bingefors, N; Bizzell, J P; Bohm, J; Brenner, R; Brodbeck, T J; Bruckman De Renstrom, P; Buttar, C M; Campbell, D; Carpentieri, C; Carter, A A; Carter, J R; Charlton, D G; Casse, G-L; Chilingarov, A; Cindro, V; Ciocio, A; Civera, J V; Clark, A G; Colijn, A-P; Costa, M J; Dabrowski, W; Danielsen, K M; Dawson, I; Demirkoz, B; Dervan, P; Dolezal, Z; Dorholt, O; Duerdoth, I P; Dwuznik, M; Eckert, S; Ekelöf, T; Eklund, L; Escobar, C; Fasching, D; Feld, L; Ferguson, D P S; Ferrere, D; Fortin, R; Foster, J M; Fox, H; French, R; Fromant, B P; Fujita, K; Fuster, J; Gadomski, S; Gallop, B J; Garcia, C; Garcia-Navarro, J E; Gibson, M D; Gonzalez, S; Gonzalez-Sevilla, S; Goodrick, M J; Gornicki, E; Green, C; Greenall, A; Grigson, C; Grillo, A A; Grosse-Knetter, J; Haber, C; Handa, T; Hara, K; Harper, R S; Hartjes, F G; Hashizaki, T; Hauff, D; Hessey, N P; Hill, J C; Hollins, T I; Holt, S; Horazdovsky, T; Hornung, M; Hovland, K M; Hughes, G; Huse, T; Ikegami, Y; Iwata, Y; Jackson, J N; Jakobs, K; Jared, R C; Johansen, L G; Jones, R W L; Jones, T J; de Jong, P; Joseph, J; Jovanovic, P; Kaplon, J; Kato, Y; Ketterer, C; Kindervaag, I M; Kodys, P; Koffeman, E; Kohriki, T; Kohout, Z; Kondo, T; Koperny, S; van der Kraaij, E; Kral, V; Kramberger, G; Kudlaty, J; Lacasta, C; Limper, M; Linhart, V; Llosa, G; Lozano, M; Ludwig, I; Ludwig, J; Lutz, G; Macpherson, A; McMahon, S J; Macina, D; Magrath, C A; Malecki, P; Mandic, I; Marti-Garcia, S; Matsuo, T; Meinhardt, J; Mellado, B; Mercer, I J; Mikestikova, M; Mikuz, M; Minano, M; Mistry, J; Mitsou, V; Modesto, P; Mohn, B; Molloy, S D; Moorhead, G; Moraes, A; Morgan, D; Morone, M C; Morris, J; Moser, H-G; Moszczynski, A; Muijs, A J M; Nagai, K; Nakamura, Y; Nakano, I; Nicholson, R; Niinikoski, T; Nisius, R; Ohsugi, T; O'Shea, V; Oye, O K; Parzefall, U; Pater, J R; Pernegger, H; Phillips, P W; Posisil, S; Ratoff, P N; Reznicek, P; Richardson, J D; Richter, R H; Robinson, D; Roe, S; Ruggiero, G; Runge, K; Sadrozinski, H F W; Sandaker, H; Schieck, J; Seiden, A; Shinma, S; Siegrist, J; Sloan, T; Smith, N A; Snow, S W; Solar, M; Solberg, A; Sopko, B; Sospedra, L; Spieler, H; Stanecka, E; Stapnes, S; Stastny, J; Stelzer, F; Stradling, A; Stugu, B; Takashima, R; Tanaka, R; Taylor, G; Terada, S; Thompson, R J; Titov, M; Tomeda, Y; Tovey, D R; Turala, M; Turner, P R; Tyndel, M; Ullan, M; Unno, Y; Vickey, T; Vos, M; Wallny, R; Weilhammer, P; Wells, P S; Wilson, J A; Wolter, M; Wormald, M; Wu, S L; Yamashita, T; Zontar, D; Zsenei, A

    2007-01-01

    This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the SemiConductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd supplied 92.2% of the 15,392 installed sensors, with the remainder supplied by CiS.

  12. Magnet design with 100-kA HTS STARS conductors for the helical fusion reactor

    Science.gov (United States)

    Yanagi, N.; Terazaki, Y.; Ito, S.; Tamura, H.; Hamaguchi, S.; Mito, T.; Hashizume, H.; Sagara, A.

    2016-12-01

    The high-temperature superconducting (HTS) option is employed for the conceptual design of the LHD-type helical fusion reactor FFHR-d1. The 100-kA-class STARS (Stacked Tapes Assembled in Rigid Structure) conductor is used for the magnet system including the continuously wound helical coils. Protection of the magnet system in case of a quench is a crucial issue and the hot-spot temperature during an emergency discharge is estimated based on the zero-dimensional and one-dimensional analyses. The number of division of the coil winding package is examined to limit the voltage generation. For cooling the HTS magnet, helium gas flow is considered and its feasibility is examined by simple analysis as a first step.

  13. Characterization of textile electrodes and conductors using standardized measurement setups.

    Science.gov (United States)

    Beckmann, L; Neuhaus, C; Medrano, G; Jungbecker, N; Walter, M; Gries, T; Leonhardt, S

    2010-02-01

    Textile electrodes and conductors are being developed and used in different monitoring scenarios, such as ECG or bioimpedance spectroscopy measurements. Compared to standard materials, conductive textile materials offer improved wearing comfort and enable long-term measurements. Unfortunately, the development and investigation of such materials often suffers from the non-reproducibility of the test scenarios. For example, the materials are generally tested on human skin which is difficult since the properties of human skin differ for each person and can change within hours. This study presents two test setups which offer reproducible measurement procedures for the systematic analysis of textile electrodes and conductors. The electrode test setup was designed with a special skin dummy which allows investigation of not only the electrical properties of textile electrodes but also the contact behavior between electrode and skin. Using both test setups, eight textile electrodes and five textile conductors were analyzed and compared.

  14. Loss and Inductance Investigation in Superconducting Cable Conductors

    DEFF Research Database (Denmark)

    Olsen, Søren Krüger; Tønnesen, Ole; Træholt, Chresten

    1999-01-01

    An important parameter in the design and optimization of a superconducting cable conductor is the control of the current distribution among single tapes and layers. This distribution is to a large degree determined by inductances, since the resistances are low. The self and mutual inductances...... of the layers are therefore studied theoretically. The current distribution between the superconducting layers is monitored as a function of transport current, and the results are compared with the expected current distribution given by our electrical circuit model.The AC-losses are measured as a function...... of transport current and current distribution.This presentation is based on a number of experiments performed on prototype superconducting cable conductors. The critical current (1uV/cm) of the conductor at 77K was 1590 A (cable #1) and 3240 A (cable #2) respectively.At an rms current of 2 kA (50 Hz) the AC...

  15. Westinghouse thermal barrier coatings development

    Energy Technology Data Exchange (ETDEWEB)

    Goedjen, J.G.; Wagner, G. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-01

    Westinghouse, in conjunction with the Department of Energy and Oak Ridge National Laboratory, has embarked upon a program for the development of advanced thermal barrier coatings for industrial gas turbines. Development of thermal barrier coatings (TBC`s) for industrial gas turbines has relied heavily on the transfer of technology from the aerospace industry. Significant differences in the time/temperature/stress duty cycles exist between these two coating applications. Coating systems which perform well in aerospace applications may not been optimized to meet power generation performance requirements. This program will focus on development of TBC`s to meet the specific needs of power generation applications. The program is directed at developing a state-of-the-art coating system with a minimum coating life of 25,000 hours at service temperatures required to meet increasing operating efficiency goals. Westinghouse has assembled a team of university and industry leaders to accomplish this goal. Westinghouse will coordinate the efforts of all program participants. Chromalloy Turbine Technologies, Inc. and Sermatech International, Inc. will be responsible for bond coat and TBC deposition technology. Praxair Specialty Powders, Inc. will be responsible for the fabrication of all bond coat and ceramic powders for the program. Southwest Research Institute will head the life prediction modelling effort; they will also be involved in coordinating nondestructive evaluation (NDE) efforts. Process modelling will be provided by the University of Arizona.

  16. Organic conductors as novel ``molecular rulers`` for advanced manufacturing processes

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.M.

    1995-12-31

    Future advanced manufacturing equipment used in high technology programs will require ultra-high precision and associated machining tool operations that require placement accuracy of {approximately} 1--100 nm (1 nm = 10 {angstrom}). There is consensus among engineers that this equipment will be based on STM (Scanning Tunneling Microscope) technology. All such STM-based ``drivers`` must contain a metrology system that requires absolute length standards referenced to atomic spacings for calibration. Properly designed organic conductor substrate crystals have the potential to be molecular rulers for STM-based advanced manufacturing equipment. The major challenges in future organic conductor research aimed at STM metrology application are listed.

  17. Alternating current flow in internally flawed conductors: A tomographic analysis

    Science.gov (United States)

    Saguy, H.; Rittel, D.

    2006-08-01

    The alternating current potential drop technique is a nondestructive testing method that is mostly applied to estimate the depth of surface breaking flaws (e.g., cracks) in metallic conductors. When the flaw is hidden (internal or bottom cracks), other techniques (e.g., radiographic) must be used, which may only provide limited information on the location and dimensions of the hidden flaw. This work presents a detailed numerical analysis of ac flow in internally flawed conductors. The results can be used to reveal and estimate the dimensions and location of hidden flaws.

  18. Design of a Wireless Sensor Module for Monitoring Conductor Galloping of Transmission Lines.

    Science.gov (United States)

    Huang, Xinbo; Zhao, Long; Chen, Guimin

    2016-10-09

    Conductor galloping may cause flashovers and even tower collapses. The available conductor galloping monitoring methods often employ acceleration sensors to measure the conductor translations without considering the conductor twist. In this paper, a new sensor for monitoring conductor galloping of transmission lines based on an inertial measurement unit and wireless communication is proposed. An inertial measurement unit is used for collecting the accelerations and angular rates of a conductor, which are further transformed into the corresponding geographic coordinate frame using a quaternion transformation to reconstruct the galloping of the conductor. Both the hardware design and the software design are described in details. The corresponding test platforms are established, and the experiments show the feasibility and accuracy of the proposed monitoring sensor. The field operation of the proposed sensor in a conductor spanning 734 m also shows its effectiveness.

  19. Cognitive and collaborative demands of freight conductor activities: results and implications of a cognitive task analysis

    Science.gov (United States)

    2012-07-31

    This report presents the results of a cognitive task analysis (CTA) that examined the cognitive and collaborative demands placed on conductors, as well as the knowledge and skills that experienced conductors have developed that enable them to operate...

  20. Task Analysis for the Jobs of Freight Train Conductor and Brakeman

    Science.gov (United States)

    1975-05-31

    This document describes the results of a research effort undertaken to detail the tasks of freight train conductors and brakemen. Included with text are detailed operational sequence diagrams for both conductor and brakeman. This task : analysis is s...

  1. Application Research on Drag Reduced Conductors for Electric Power Transmission Lines in Strong Wind Areas

    Directory of Open Access Journals (Sweden)

    Li Dong Qing

    2016-01-01

    Full Text Available The breeze vibration duration of conductors is long, the vibration amplitude is strong and the frequency range is wide for electric power transmission lines in strong wind areas, which seriously affects the safe and stable operation of transmission lines. There are two design schemes of conductors which can achieve the purpose of reducing wind-induced disaster. One is enhancing the structural strength of conductors to withstand wind load, but the investment is enormous and the effect is limited. The other is developing drag reduced conductors to reduce wind load by changing conductor structure. This paper started from application feasibility analysis of drag reduced conductors and designed four drag reduced conductors by structure optimization of the conventional aluminium conductor steel reinforced JL/G1A-630/45-45/7, denoted as DFY630/45(45°-R3.5, DFY630/45(60°-R3.5, DFY630/45(45°–R3.2 and DFY630/45(60°-R3.2, respectively. The wind tunnel test was performed and the wind resistance coefficients in unit length of five conductors were compared. Result showed that the wind resistance coefficients in unit length of four drag reduced conductors were obviously lower than that of the conventional conductor. By controlling the manufacturing process, popularization and application of drag reduced conductors for transmission lines in strong wind areas can be realized.

  2. 30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

    Science.gov (United States)

    2010-07-01

    ... Electrical Equipment-General § 75.521 Lightning arresters; ungrounded and exposed power conductors and telephone wires. Each ungrounded, exposed power conductor and each ungrounded, exposed telephone wire that... power conductors and telephone wires. 75.521 Section 75.521 Mineral Resources MINE SAFETY AND HEALTH...

  3. 33 CFR 183.430 - Conductors in circuits of less than 50 volts.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Conductors in circuits of less... HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems Manufacturer Requirements § 183.430 Conductors in circuits of less than 50 volts. (a) Each conductor in a circuit that has a...

  4. 30 CFR 57.12005 - Protection of power conductors from mobile equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of power conductors from mobile... NONMETAL MINES Electricity Surface and Underground § 57.12005 Protection of power conductors from mobile equipment. Mobile equipment shall not run over power conductors, nor shall loads be dragged over power...

  5. 30 CFR 57.12010 - Isolation or insulation of communication conductors.

    Science.gov (United States)

    2010-07-01

    ... conductors. 57.12010 Section 57.12010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... conductors. Telephone and low-potential signal wire shall be protected, by isolation or suitable insulation, or both, from contacting energized power conductors or any other power source. ...

  6. The Spore Coat.

    Science.gov (United States)

    Driks, Adam; Eichenberger, Patrick

    2016-04-01

    Spores of Clostridiales and Bacillales are encased in a complex series of concentric shells that provide protection, facilitate germination, and mediate interactions with the environment. Analysis of diverse spore-forming species by thin-section transmission electron microscopy reveals that the number and morphology of these encasing shells vary greatly. In some species, they appear to be composed of a small number of discrete layers. In other species, they can comprise multiple, morphologically complex layers. In addition, spore surfaces can possess elaborate appendages. For all their variability, there is a consistent architecture to the layers encasing the spore. A hallmark of all Clostridiales and Bacillales spores is the cortex, a layer made of peptidoglycan. In close association with the cortex, all species examined possess, at a minimum, a series of proteinaceous layers, called the coat. In some species, including Bacillus subtilis, only the coat is present. In other species, including Bacillus anthracis, an additional layer, called the exosporium, surrounds the coat. Our goals here are to review the present understanding of the structure, composition, assembly, and functions of the coat, primarily in the model organism B. subtilis, but also in the small but growing number of other spore-forming species where new data are showing that there is much to be learned beyond the relatively well-developed basis of knowledge in B. subtilis. To help summarize this large field and define future directions for research, we will focus on key findings in recent years.

  7. Attentional flexibility and memory capacity in conductors and pianists.

    Science.gov (United States)

    Wöllner, Clemens; Halpern, Andrea R

    2016-01-01

    Individuals with high working memory (WM) capacity also tend to have better selective and divided attention. Although both capacities are essential for skilled performance in many areas, evidence for potential training and expertise effects is scarce. We investigated the attentional flexibility of musical conductors by comparing them to equivalently trained pianists. Conductors must focus their attention both on individual instruments and on larger sections of different instruments. We studied students and professionals in both domains to assess the contributions of age and training to these skills. Participants completed WM span tests for auditory and visual (notated) pitches and timing durations, as well as long-term memory tests. In three dichotic attention tasks, they were asked to detect small pitch and timing deviations from two melodic streams presented in baseline (separate streams), selective-attention (concentrating on only one stream), and divided-attention (concentrating on targets in both streams simultaneously) conditions. Conductors were better than pianists in detecting timing deviations in divided attention, and experts detected more targets than students. We found no group differences for WM capacity or for pitch deviations in the attention tasks, even after controlling for the older age of the experts. Musicians' WM spans across multimodal conditions were positively related to selective and divided attention. High-WM participants also had shorter reaction times in selective attention. Taken together, conductors showed higher attentional flexibility in successfully switching between different foci of attention.

  8. Violence Against Drivers and Conductors in the Road Passenger ...

    African Journals Online (AJOL)

    This cross-sectional study examined the extent, nature and risk factors of workplace violence in the road passenger transport sector in Maputo, the capital city of Mozambique. A random sample of 504 participants was selected from a population of 2 618 registered bus, minibus, and taxi drivers/conductors. The results ...

  9. Women Conductors: A Study of an Italian Major Symphony Orchestra

    African Journals Online (AJOL)

    The investigation sought the opinion of members of Orchestra Sinfonica Nazionale della RAI on a performance directed by a woman. The assumption was that not being used to be directed by a woman would affect their opinion on the individual's ability and on all women conductors, i.e. if few women are invited to be guest ...

  10. 30 CFR 77.503-1 - Electric conductors.

    Science.gov (United States)

    2010-07-01

    ... the minimum current carrying capacity provided for in the National Electric Code, 1968. All trailing... Cable Engineers Association—National Electric Manufacturers Association in effect when such cables are... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric conductors. 77.503-1 Section 77.503-1...

  11. 30 CFR 75.513-1 - Electric conductor; size.

    Science.gov (United States)

    2010-07-01

    ... capacity if it is smaller than is provided for in the National Electric Code, 1968. In addition, equipment... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric conductor; size. 75.513-1 Section 75... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.513-1...

  12. An Organic Mixed Ion–Electron Conductor for Power Electronics

    DEFF Research Database (Denmark)

    Malti, Abdellah; Edberg, Jesper; Granberg, Hjalmar

    2016-01-01

    A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting...

  13. An Organic Mixed Ion-Electron Conductor for Power Electronics

    DEFF Research Database (Denmark)

    Malti, Abdellah; Edberg, Jesper; Granberg, Hjalmar

    2016-01-01

    A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting...

  14. Charge densities and charge noise in mesoscopic conductors

    Indian Academy of Sciences (India)

    February 2002 physics pp. 241–257. Charge densities and charge noise in mesoscopic conductors ... the charge noise [6] based on the scattering approach. Similar to the discussion of linear ...... a novel resistance which determines the dissipative effects in charging and decharging a. 254. Pramana – J. Phys., Vol. 58, No.

  15. Stable Delay of Microstrip Line with Side Grounded Conductors

    OpenAIRE

    Gazizov, T. R.; Salov, V. K.; Kuksenko, S. P.

    2017-01-01

    Characteristics of transmission lines are addressed. Wave impedance and per-unit-length delay of the microstrip structure with grounded side conductors on three layers are calculated under different parameters of the structure. A line which provides the desired value of wave impedance and constant per-unit-length delay, at the expense of correction of the gaps on different layers, is proposed.

  16. Low-frequency scattering from two-dimensional perfect conductors

    DEFF Research Database (Denmark)

    Hansen, Thorkild; Yaghjian, A.D

    1991-01-01

    Exact expressions have been obtained for the leading terms in the low-frequency expansions of the far fields scattered from three different types of two-dimensional perfect conductors: a cylinder with finite cross section, a cylindrical bump on an infinite ground plane, and a cylindrical dent...

  17. Application of the Lifshitz theory to poor conductors

    NARCIS (Netherlands)

    Svetovoy, Vitaly

    2008-01-01

    The Lifshitz formula for dispersive forces is generalized to the materials, which cannot be described with the local dielectric response. The principal nonlocality of poor conductors is related to the finite screening length of the penetrating field and collisional relaxation; at low temperatures

  18. Flexible electrical conductors for high-temperature switchgear

    Science.gov (United States)

    Koutnik, E. A.; Mueller, L. A.; Snider, W. E.

    1970-01-01

    Arch-shaped conductors fabricated from flat strips of beryllium oxide dispersion-strengthened copper alloy serve as flexible electrical connectors capable of operating in 1000 deg F temperature range, under vacuum conditions for periods of 10,000 hours or more without failure.

  19. First-principles electronic-band calculations on organic conductors

    Directory of Open Access Journals (Sweden)

    Shoji Ishibashi

    2009-01-01

    Full Text Available Predicting electronic-band structures is a key issue in understanding the properties of materials or in materials design. In this review article, application examples of first-principles calculations, which are not based on adjustable empirical parameters, to study electronic structures of organic conductors are described.

  20. Effect of annular secondary conductor in a linear electromagnetic ...

    Indian Academy of Sciences (India)

    This paper presents the variation of average axial force density in the annular secondary conductor of a linear electromagnetic stirrer. ... Department of Electrical Engineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076; Power Electronics Group, Department of Electrical Engineering, Indian Institute of ...

  1. 46 CFR 111.05-31 - Grounding conductors for systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Grounding conductors for systems. 111.05-31 Section 111.05-31 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-31...

  2. Charge densities and charge noise in mesoscopic conductors

    Indian Academy of Sciences (India)

    We introduce a hierarchy of density of states to characterize the charge distribution in a mesoscopic conductor. At the bottom of this hierarchy are the partial density of states which represent the contribution to the local density of states if both the incident and the out-going scattering channel is prescribed. The partial density ...

  3. probing the cob(ii)alamin conductor hypothesis with glutamate ...

    African Journals Online (AJOL)

    dell

    ABSTRACT. It had been proposed that during reversible coenzyme B12 dependent rearrangements, cob(II)alamin is not merely present as a spectator but also acts as a conductor by stabilizing the methylene radical intermediates. Density functional theory (DFT) calculations suggested a hydrogen bond between C19-H of ...

  4. An electrical test system for conductor formation process analysis

    Energy Technology Data Exchange (ETDEWEB)

    Estes, T.A. [Sandia National Labs., Albuquerque, NM (United States); Rhodes, R.J. [AT and T Bell Labs., Whippany, NJ (United States)

    1994-03-01

    Sandia National Laboratories has designed and built an electrical test system which fulfills a requirement to quickly, accurately and precisely measure the resistance of conductors formed on Printed Wiring Board (PWB) substrates. This requirement stems from the need to measure small variations in conductors and thus to determine the source of the variations. With this test technology, experiments can be conducted with new materials, equipment, and processes in a timely and scientific manner. Conductor formation processes can be optimized for both conductor yield and uniformity, and process equipment can be fine-tuned prior to processing product to ensure that conductor attributes fulfill requirements. Significant resources have been spent by Sandia National Laboratories and Texas Instruments modifying commercially available two-probe testers. AT&T has built a two-probe tester and obtained a commercially available ``bed-of-nails`` test system. The two-probe systems have limitations in speed and precision; the ``bed-of-nails`` system has proved to be superior to the two-probe designs but is expensive, and lacks test pattern flexibility and ease of use. Due to the need to establish a testing technology which meets the requirements of Sandia National Laboratories and the National Center for Manufacturing Sciences PWB Consortium Imaging Team (current Imaging Team members; AT&T, Texas Instruments, AlliedSignal, IBM, and Sandia National Laboratories), a prototype test system was designed and built by Sandia. This paper will discuss the design and performance of the test system and the results of a comparison to other test systems.

  5. Design of multiband metamaterial absorber based on artificial magnetic conductor

    Science.gov (United States)

    Dang, Kezheng; He, Zijian; Li, Zhigang; Miao, Lei; Liu, Hao

    2015-10-01

    We present a general method to design multiband absorber by replacing the ground plane in a conventional metamaterial absorber with an artificial magnetic conductor. Due to its unique property of in-phase reflection at some specific frequency, the artificial magnetic conductor is used to introduce new absorption in the operation band. Meanwhile, out of the in-phase reflection band, the original absorbing capability of the absorber is reserved. To demonstrate it, we design a metamaterial absorber comprising three layers which are grids patterned resistive frequency selective surface, dielectric layer and the ground plane respectively. With an appropriate design, the absorber performs an absorbing peak at about 10 GHz. Then, we utilize a single band artificial magnetic conductor at 6.25 GHz and a dual-band one at 6.27 GHz and 8.17 GHz, which are both lossy and comprised of patches array varying in periodic size with a thickness of 0.6 mm, to replace the ground plane in the metamaterial absorber separately. The reflectivity of these multiband absorbers are simulated, and experiments are carried out later. Experimental results agree well with the simulations. All results verified that the method presented at the beginning is effective. The results show that additional absorptions exist at the frequencies where microwaves are nearly reflected in phase on the artificial magnetic conductor. Meanwhile the original absorbing capability of the metamaterial absorber has been preserved mostly. Based on the artificial magnetic conductor, the multiband absorber performs better with an increasing absorption bandwidth from 8.5 GHz to 10 GHz compared to the metamaterial absorber.

  6. Research on High Temperature Ceramic Insulation for Electrical Conductors

    Science.gov (United States)

    Kreidler, Eric R.; Bhallamudi, Vidya Praveen

    2001-01-01

    Three methods for applying ceramic coatings to wires were examined in depth and a fourth (chemical vapor deposition) was studied briefly. CVD coatings were not reported in the thesis because it was realized early in the study that the deposition rate of the coatings was too slow to be used in a commercial process. Of the methods reported in the thesis, slurry coating was the most promising. This method consists of slowly drawing a platinum wire through a thixotropic slurry of alumina in a vehicle composed of polyvinyl butyral, methyl ethyl ketone, and toluene. The coatings produced by this method were continuous and free of cracks after sintering. The sintered coatings crack when the wire is bent around sharp corners, but most of the coating remains in place and still provides electrical insulation between the wire and any metallic structure to which the wire may be attached. The coating thickness was 0.61 mm (16 micrometers). The electrical resistivity of the intact coating was 340 M-Ohm-cm at 800 C and 23 M-Ohm-cm at 1050 C. Therefore, these coatings more than meet the electrical requirements for use in turbine engines. Although adherence of the coating to the wire was generally excellent, a problem was noted in localized areas where the coating flaked off. Further work will be needed to obtain good coating adherence along the entire length of the wire. The next most promising coatings were made by electrophoretic deposition (EPD) of Al2O3 onto platinum wires, using mixtures of ethanol and acetone as the suspending liquid. These EPD coatings were made only on short lengths of wire because the coating is too fragile to allow spooling of the wire. The worst coatings were those made by electrophoretic deposition from aqueous suspensions. Continuous slurry coating of wire was achieved, but due to lack of suitable equipment, the wire had to be cut into short lengths for sintering.

  7. Verification of a Novel Method of Detecting Faults in Medium-Voltage Systems with Covered Conductors

    Directory of Open Access Journals (Sweden)

    Mišák Stanislav

    2017-06-01

    Full Text Available This paper describes the use of new methods of detecting faults in medium-voltage overhead lines built of covered conductors. The methods mainly address such faults as falling of a conductor, contacting a conductor with a tree branch, or falling a tree branch across three phases of a medium-voltage conductor. These faults cannot be detected by current digital relay protection systems. Therefore, a new system that can detect the above mentioned faults was developed. After having tested its operation, the system has already been implemented to protect mediumvoltage overhead lines built of covered conductors.

  8. Aplicación de simuladores en la formación de los conductores

    OpenAIRE

    Pardillo Mayora, José M.; Jurado Piña, Rafael

    2008-01-01

    Los simuladores de conducción permiten reproducir el proceso de conducción en un vehículo en un entorno virtual. Los simuladores se emplean en la formación de los conductores de distintas categorías: conductores noveles, perfeccionamiento de conductores profesionales, conductores discapacitados y conductores de edad avanzada. En la comunicación se sintetizan los resultados obtenidos en el marco de la Red de Excelencia HUMANIST (HUMAN centred design for Information Society Technologies) del VI...

  9. Structure Design and Service Performance Study of Low Wind-pressure Conductor

    Directory of Open Access Journals (Sweden)

    Wang Zhao Lin

    2016-01-01

    Full Text Available The low wind-pressure conductor is a dedicated conductor which obtains low wind resistance coefficient by changing the sectional shape of the conductor and has extensive application prospect in electric power transmission lines in strong wind areas. Previous wind tunnel testing results showed that the wind resistance coefficient in unit length of the low wind-pressure aluminium conductor steel reinforced was obviously lower than that of the conventional aluminium conductor steel reinforced, and the control factors of manufacturing process of the low wind-pressure conductor were proposed. In this paper, the low wind-pressure aluminium conductor steel reinforced JLX1/G1A(DFY–680/45–338 was designed based on the structure optimization of the conventional aluminium conductor steel reinforced JL/G1A–630/45–45/7, and the service performance study of the conductor was carried out. Results showed that the mechanical properties, electrical properties and construction properties of the low wind-pressure conductor fully satisfied service requirements, and the conductor can be popularized and applied for transmission lines in strong wind areas.

  10. Test results of the FER/ITER conductors in the FENIX test facility

    Science.gov (United States)

    Sugimoto, M.; Isono, T.; Koizumi, K.; Takahashi, Y.; Nishi, M.; Okuno, K.; Yoshida, K.; Nakajima, H.; Ando, T.; Hosono, F.

    1994-07-01

    The Japan Atomic Energy Research Institute (JAERI) has developed the Advanced Disk and the Hollow Monolithic conductors for the FER/ITER Toroidal Field coils. The Advanced Disk conductor is a Cable-in-Conduit conductor which consists of 324 Nb3Sn strands. The Hollow monolithic conductor has hollow cooling channels and 23 Nb3Sn strands. The JA-FENIX sample consists of a pair of straight legs: one leg is the Advanced disk conductor and another is the Hollow Monolithic one. The FENIX facility at the Lawrence Livermore National Laboratory (LLNL) can provide a magnetic field up to 13T on a sample conductor of over 40cm-length. The performance test of the JA-sample was carried out in Autumn 1992. The critical current, the current sharing temperature, and the stability margin of each conductor were measured in this test. These results are presented and discussed.

  11. Advanced membrane electrode assemblies for fuel cells

    Science.gov (United States)

    Kim, Yu Seung; Pivovar, Bryan S

    2014-02-25

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  12. Crystallization of DNA-coated colloids

    Science.gov (United States)

    Wang, Yu; Wang, Yufeng; Zheng, Xiaolong; Ducrot, Étienne; Yodh, Jeremy S.; Weck, Marcus; Pine, David J.

    2015-01-01

    DNA-coated colloids hold great promise for self-assembly of programmed heterogeneous microstructures, provided they not only bind when cooled below their melting temperature, but also rearrange so that aggregated particles can anneal into the structure that minimizes the free energy. Unfortunately, DNA-coated colloids generally collide and stick forming kinetically arrested random aggregates when the thickness of the DNA coating is much smaller than the particles. Here we report DNA-coated colloids that can rearrange and anneal, thus enabling the growth of large colloidal crystals from a wide range of micrometre-sized DNA-coated colloids for the first time. The kinetics of aggregation, crystallization and defect formation are followed in real time. The crystallization rate exhibits the familiar maximum for intermediate temperature quenches observed in metallic alloys, but over a temperature range smaller by two orders of magnitude, owing to the highly temperature-sensitive diffusion between aggregated DNA-coated colloids. PMID:26078020

  13. Crystallization of DNA-coated colloids.

    Science.gov (United States)

    Wang, Yu; Wang, Yufeng; Zheng, Xiaolong; Ducrot, Étienne; Yodh, Jeremy S; Weck, Marcus; Pine, David J

    2015-06-16

    DNA-coated colloids hold great promise for self-assembly of programmed heterogeneous microstructures, provided they not only bind when cooled below their melting temperature, but also rearrange so that aggregated particles can anneal into the structure that minimizes the free energy. Unfortunately, DNA-coated colloids generally collide and stick forming kinetically arrested random aggregates when the thickness of the DNA coating is much smaller than the particles. Here we report DNA-coated colloids that can rearrange and anneal, thus enabling the growth of large colloidal crystals from a wide range of micrometre-sized DNA-coated colloids for the first time. The kinetics of aggregation, crystallization and defect formation are followed in real time. The crystallization rate exhibits the familiar maximum for intermediate temperature quenches observed in metallic alloys, but over a temperature range smaller by two orders of magnitude, owing to the highly temperature-sensitive diffusion between aggregated DNA-coated colloids.

  14. Study on Evolution of Coating State and Role of Graphene in Graphene-Modified Low-Zinc Waterborne Epoxy Anticorrosion Coating by Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Ding, Rui; Wang, Xiao; Jiang, Jianming; Gui, Taijiang; Li, Weihua

    2017-07-01

    In this paper, corrosion potential and impedance response of the graphene-modified low-zinc waterborne epoxy anticorrosion coating with different compositions were measured experimentally. Microstructure impedance analysis approach was proposed, which was applied to analyze in detail the system impedance and to clarify the variation of coating state as well as the role of graphene in the coating. Results showed that the variation course of coating state was divided into four stages: activation stage; cathodic protection stage; shielding protection stage; and failure stage. Graphene formed numerous isolation layers in the coating to hinder the diffusion of aggressive particles like water and oxygen as well as corrosion products, which played a certain shielding protective role. Moreover, graphene was a good electron conductor, which enabled the outer layer zinc to continue to constitute a galvanic couple with the iron substrate after cathodic protection stage, thereby prolonging the protective effect of the coating to some extent.

  15. Bending Test of Conductor for ALICE and LHCb Dipole Magnets

    CERN Document Server

    Giudici, P A; CERN. Geneva; Flegel, W

    2000-01-01

    Abstract It is foreseen that the coils for the two magnets will be manufactured by winding flat pancakes, which are subsequently shaped to a semi-cylindrical form (ALICE) or bent by 45 degrees (LHCb). We propose here several methods and describe tests that were performed to estimate tolerances and forces which will have to be expected during the manufacturing process. To this end, short Aluminium conductor lengths of adequate cross-section were bent around a shaper piece to an angle of 90 degrees. The tests were repeated for conductors both wrapped with prepreg insulation tape and without this tape. The different test set-ups and the obtained results are described in this note.

  16. Mixed protonic and electronic conductors hybrid oxide synaptic transistors

    Science.gov (United States)

    Fu, Yang Ming; Zhu, Li Qiang; Wen, Juan; Xiao, Hui; Liu, Rui

    2017-05-01

    Mixed ionic and electronic conductor hybrid devices have attracted widespread attention in the field of brain-inspired neuromorphic systems. Here, mixed protonic and electronic conductor (MPEC) hybrid indium-tungsten-oxide (IWO) synaptic transistors gated by nanogranular phosphorosilicate glass (PSG) based electrolytes were obtained. Unique field-configurable proton self-modulation behaviors were observed on the MPEC hybrid transistor with extremely strong interfacial electric-double-layer effects. Temporally coupled synaptic plasticities were demonstrated on the MPEC hybrid IWO synaptic transistor, including depolarization/hyperpolarization, synaptic facilitation and depression, facilitation-stead/depression-stead behaviors, spiking rate dependent plasticity, and high-pass/low-pass synaptic filtering behaviors. MPEC hybrid synaptic transistors may find potential applications in neuron-inspired platforms.

  17. Effects of particle size distribution in thick film conductors

    Science.gov (United States)

    Vest, R. W.

    1983-01-01

    Studies of particle size distribution in thick film conductors are discussed. The distribution of particle sizes does have an effect on fired film density but the effect is not always positive. A proper distribution of sizes is necessary, and while the theoretical models can serve as guides to selecting this proper distribution, improved densities can be achieved by empirical variations from the predictions of the models.

  18. Stable Delay of Microstrip Line with Side Grounded Conductors

    Directory of Open Access Journals (Sweden)

    T. R. Gazizov

    2017-01-01

    Full Text Available Characteristics of transmission lines are addressed. Wave impedance and per-unit-length delay of the microstrip structure with grounded side conductors on three layers are calculated under different parameters of the structure. A line which provides the desired value of wave impedance and constant per-unit-length delay, at the expense of correction of the gaps on different layers, is proposed.

  19. Homogeneous bilayer graphene film based flexible transparent conductor

    OpenAIRE

    Lee, Seunghyun; Lee, Kyunghoon; Liu, Chang-Hua; Zhong, Zhaohui

    2011-01-01

    Graphene is considered a promising candidate to replace conventional transparent conductors due to its low opacity, high carrier mobility and flexible structure. Multi-layer graphene or stacked single layer graphenes have been investigated in the past but both have their drawbacks. The uniformity of multi-layer graphene is still questionable, and single layer graphene stacks require many transfer processes to achieve sufficiently low sheet resistance. In this work, bilayer graphene film grown...

  20. Overcurrent experiments on HTS tape and cable conductor

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Jensen, Kim Høj; Træholt, Chresten

    2001-01-01

    Overcurrents in the power grid can have a magnitude of up to 20 times or higher than the rated current. This may cause problems and permanent damage to electrical equipment in the grid. High temperature superconducting (HTS) tapes are known to be sensitive to currents much larger than their criti......Overcurrents in the power grid can have a magnitude of up to 20 times or higher than the rated current. This may cause problems and permanent damage to electrical equipment in the grid. High temperature superconducting (HTS) tapes are known to be sensitive to currents much larger than...... their critical current. In this light, it is important to investigate the response of HTS tapes and cable conductors to overcurrents several times the critical current. A number of experiments have been performed on HTS tapes and cable conductors, with currents up to 20 times the critical current. During...... overcurrent experiments, the voltage, and the temperature were measured as functions of time in order to investigate the dynamic behavior of the HTS tape and cable conductor. After each experiment, damage to the superconductors was assessed by measuring the critical current. Preliminary results show...

  1. Quantum oscillations in quasi-two-dimensional conductors

    CERN Document Server

    Galbova, O

    2002-01-01

    The electronic absorption of sound waves in quasi-two-dimensional conductors in strong magnetic fields, is investigated theoretically. A longitudinal acoustic wave, propagating along the normal n-> to the layer of quasi-two-dimensional conductor (k-> = left brace 0,0,k right brace; u-> = left brace 0,0,u right brace) in magnetic field (B-> = left brace 0, 0, B right brace), is considered. The quasiclassical approach for this geometry is of no interest, due to the absence of interaction between electromagnetic and acoustic waves. The problem is of interest in strong magnetic field when quantization of the charge carriers energy levels takes place. The quantum oscillations in the sound absorption coefficient, as a function of the magnetic field, are theoretically observed. The experimental study of the quantum oscillations in quasi-two-dimensional conductors makes it possible to solve the inverse problem of determining from experimental data the extrema closed sections of the Fermi surface by a plane p sub z = ...

  2. Conductors for commercial MRI magnets beyond NbTi: requirements and challenges

    Science.gov (United States)

    Parizh, Michael; Lvovsky, Yuri; Sumption, Michael

    2017-01-01

    Magnetic resonance imaging (MRI), a powerful medical diagnostic tool, is the largest commercial application of superconductivity. The superconducting magnet is the largest and most expensive component of an MRI system. The magnet configuration is determined by competing requirements including optimized functional performance, patient comfort, ease of siting in a hospital environment, minimum acquisition and lifecycle cost including service. In this paper, we analyze conductor requirements for commercial MRI magnets beyond traditional NbTi conductors, while avoiding links to a particular magnet configuration or design decisions. Potential conductor candidates include MgB2, ReBCO and BSCCO options. The analysis shows that no MRI-ready non-NbTi conductor is commercially available at the moment. For some conductors, MRI specifications will be difficult to achieve in principle. For others, cost is a key barrier. In some cases, the prospects for developing an MRI-ready conductor are more favorable, but significant developments are still needed. The key needs include the development of, or significant improvements in: (a) conductors specifically designed for MRI applications, with form-fit-and-function readily integratable into the present MRI magnet technology with minimum modifications. Preferably, similar conductors should be available from multiple vendors; (b) conductors with improved quench characteristics, i.e. the ability to carry significant current without damage while in the resistive state; (c) insulation which is compatible with manufacturing and refrigeration technologies; (d) dramatic increases in production and long-length quality control, including large-volume conductor manufacturing technology. In-situ MgB2 is, perhaps, the closest to meeting commercial and technical requirements to become suitable for commercial MRI. Conductor technology is an important, but not the only, issue in introduction of HTS/MgB2 conductor into commercial MRI magnets. These

  3. The Conductor-Dielectric Junctions in a Low Density Plasma

    Science.gov (United States)

    Vayner, Boris; Galofaro, Joel; Ferguson, Dale; deGroot, Wim; Thomson, Clint; Dennison, J. R.; Davies, Robert

    1999-01-01

    A conductor-dielectric junction exposed to the space environment is a frequent spacecraft design feature. Due to spacecraft charging and/or solar array operation, the conductor can acquire a high potential with respect to the surrounding plasma. If this potential is positive the insulators adjacent to exposed conductors can collect current as if they were conductors themselves. This phenomenon, called snapover, results in a substantial increase in current collection, and may even result in a glow discharge if the potential is high enough. If a conductor has a negative potential, arcing can occur at the site of a junction. Both of these phenomena negatively affect spacecraft operation. To prevent negative consequences, the physical mechanisms of snapover and arc inception require investigation. In this paper, results are presented of an experimental and theoretical study of snapover, glow discharge, and arc phenomena for different materials immersed in argon or xenon plasmas. The effect of snapover is investigated for several metal-dielectric junctions: copper-teflon, copper-Kapton, copper-glass, aluminum-teflon, aluminum-Kapton, steel-teflon, anodized aluminum with pinholes, and copper-ceramics. I-V curves are measured and snapover inception voltages, essential parameters (increase in current and collection area due to secondary electrons), and glow discharge inception thresholds are determined. Optical spectra are obtained for glow discharges in both argon and xenon plasmas. These spectra provide information regarding atomic species entrapped in the glow region. Some spectral lines can be used to estimate plasma parameters in the discharge area. A video-camera and linear array were used to confirm that snapover inception is accompanied by very low intensity visible light emission. This result seems to be important for the estimate of the light pollution around spacecraft. Optical spectra (wavelengths 380-650 nm) of arcs are also obtained on a negatively biased

  4. Coarse-grained Simulations of Viral Assembly

    Science.gov (United States)

    Elrad, Oren M.

    2011-12-01

    The formation of viral capsids is a marvel of natural engineering and design. A large number (from 60 to thousands) of protein subunits assemble into complete, reproducible structures under a variety of conditions while avoiding kinetic and thermodynamic traps. Small single-stranded RNA viruses not only assemble their coat proteins in this fashion but also package their genome during the self-assembly process. Recent experiments have shown that the coat proteins are competent to assemble not merely around their own genomes but heterologous RNA, synthetic polyanions and even functionalized gold nanoparticles. Remarkably these viruses can even assemble around cargo not commensurate with their native state by adopting different morphologies. Understanding the properties that confer such exquisite precision and flexibility to the assembly process could aid biomedical research in the search for novel antiviral remedies, drug-delivery vehicles and contrast agents used in bioimaging. At the same time, viral assembly provides an excellent model system for the development of a statistical mechanical understanding of biological self-assembly, in the hopes of that we will identify some universal principles that underly such processes. This work consists of computational studies using coarse-grained representations of viral coat proteins and their cargoes. We find the relative strength of protein-cargo and protein-protein interactions has a profound effect on the assembly pathway, in some cases leading to assembly mechanisms that are markedly different from those found in previous work on the assembly of empty capsids. In the case of polymeric cargo, we find the first evidence for a previously theorized mechanism in which the polymer actively participates in recruiting free subunits to the assembly process through cooperative polymer-protein motions. We find that successful assembly is non-monotonic in protein-cargo affinity, such affinity can be detrimental to assembly if it

  5. Strategic Research on Performance Optimization of YBa2Cu3O7 Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL; Christen, David K [ORNL; Kim, Kyunghoon [ORNL; Lupini, Andrew R [ORNL; Paranthaman, Mariappan Parans [ORNL; Polat, Ozgur [ORNL; Thompson, James R [ORNL; Xiong, X. [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Meyer III, Harry M [ORNL; Qiu, Xiaofeng [ORNL

    2008-01-01

    Practical applications of second generation (2G) high temperature superconductor (HTS) wires require high critical current density, Jc, at high temperatures and magnetic fields. It has been well established that Jc can be increased via nanostructural engineering of artificial pinning centers within the HTS matrix. In the present work, composite LaMnO3:MgO (LMO:MgO) cap buffer layers with varying MgO contents 5 vol% up to 75 vol% have been grown on homo-epi MgO/IBAD(MgO) substrates to enhance the performance of YBa2Cu3O7-x (YBCO) films. Results showed formation of phase separated MgO nanocolumns within the LMO matrix. The impact of these nanocolumns on the superconducting properties of YBCO films deposited on the nanostructured layer was investigated by electrical transport measurements. Such YBCO films showed better in-field performance compared to that of YBCO films on standard LMO cap films. In particular, measurements of the field-angle dependence revealed c-axis correlated pinning for YBCO films on these composite cap layers. The present results demonstrate a practical approach to obtain high performance superconducting wires.

  6. Study on Fabrication of Ni-5 at.%W Tapes for Coated Conductors from Cylinder Ingots

    DEFF Research Database (Denmark)

    Ma, L.; Suo, H. L.; Yue, Zhao

    2015-01-01

    Ni-5 at.%W (Ni5W) tapes with a strong cube texture were fabricated using the RABiTS technique and by starting from cylindrical shaped ingots. In contrast to a conventional cuboid-shaped ingot, a cylinder shaped ingot has no anisotropy along the axial direction and the resulting tape will therefore...

  7. Measurement of AC losses in a racetrack superconducting coil made from YBCO coated conductor

    DEFF Research Database (Denmark)

    Seiler, Eugen; Abrahamsen, Asger Bech; Kovac, Jan

    2012-01-01

    to reinforce it. The AC loss is measured versus the transport current Ia with the coil immersed in liquid nitrogen. Measurements at frequencies 21 Hz, 36 Hz and 72 Hz are compared. The AC losses follow I2 a dependence at low current amplitudes and I3 a at high amplitudes. After cutting the inner steel frame...

  8. Degradation of YBCO coated conductors caused by over-current pulses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X; Ueda, H; Ishiyama, A [Department of Electrical Engineering and Bioscience, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Iijima, Y; Saitoh, T [Fujikura Ltd., Material Technology Laboratory, Koto-ku, Tokyo 135-8512 (Japan); Kashima, N; Mori, M; Watanabe, T; Nagaya, S [Chubu Electric Power Co., Inc., Nagoya 459-8522 (Japan); Katoh, T [Japan Fine Ceramics Center, Nanostructures Research Laboratory, Tokyo 105-0003 (Japan); Machi, T; Shiohara, Y [International Superconductivity Technology Center, Superconductivity Research Laboratory, Koto-ku, Tokyo 135-0062 (Japan)], E-mail: atsushi@waseda.jp

    2008-02-01

    YBCO tapes are expected to be used in future high temperature superconductor (HTS) applications because they have excellent J{sub c} characteristics at high temperatures and in high magnetic fields. For application to electric power devices such as transmission cables, transformers, and fault current limiters, the YBCO tapes might be subjected to a short-circuit fault current that is 10-30 times the normal operating current. In a worst-case scenario, YBCO tapes may degrade and burn. Therefore, it is important to clarify the mechanism of the degradation caused by an over-current pulse. This paper describes the experimental results of the degradation of the YBCO tapes through a series of over-current pulse tests. We focussed on the degradation temperature and carried out the experiments with different bending strains. Measurements were performed as a function of the amplitude of an over-current pulse for an operating temperature of 80 K (Gifford-McMahon cryocooler was adopted) in a self-field. We also examined a tape after the experiments with magneto-optical (MO) imaging, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron diffraction patterns.

  9. 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

    The microstructure, texture, hardness and magnetization have been investigated in a series of strongly cube-textured (Ni95W 5)100-xCux samples with x=0, 5, 10 and 15 at% Cu. It is found that the addition of 5 at% Cu to the Ni-5 at% W alloy results in a substantial decrease of the Curie temperatur...

  10. Creation of high-pinning microstructures in post production YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Welp, Ulrich; Miller, Dean J.; Kwok, Wai-Kwong; Rupich, Martin W.; Fleshler, Steven; Malozemoff, Alexis P.

    2017-01-10

    A method comprising irradiating a polycrystalline rare earth metal-alkaline earth metal-transition metal-oxide superconductor layer with protons having an energy of 1 to 6 MeV. The irradiating process produces an irradiated layer that comprises randomly dispersed defects with an average diameter in the range of 1-10 nm.

  11. Strengthened, biaxially textured Ni substrate with small alloying additions for coated conductor applications

    Science.gov (United States)

    Goyal, A.; Feenstra, R.; Paranthaman, M.; Thompson, J. R.; Kang, B. Y.; Cantoni, C.; Lee, D. F.; List, F. A.; Martin, P. M.; Lara-Curzio, E.; Stevens, C.; Kroeger, D. M.; Kowalewski, M.; Specht, E. D.; Aytug, T.; Sathyamurthy, S.; Williams, R. K.; Ericson, R. E.

    2002-11-01

    Fabrication of a biaxially textured, strengthened Ni substrate with small alloying additions of W and Fe is reported. The substrates have significantly improved mechanical properties compared to 99.99% Ni and surface characteristics which are similar to that of 99.99% Ni substrates. High quality oxide buffer layers can be deposited on these substrates without the need for any additional surface modification steps. Grain boundary misorientation distributions obtained from the substrate show a predominant fraction of low-angle grain boundaries. A high critical current density, Jc, of 1.9 MA/cm 2 at 77 K, self-field is demonstrated on this substrate using a multilayer configuration of YBCO/CeO 2/YSZ/Y 2O 3/ Ni-3at.%W-1.7at.%Fe. This translates to a Ic/width of 59 A/cm at 77 K and self-field. Jc at 0.5 T is reduced by only 21% indicating strongly-linked grain boundaries in the YBCO film on this substrate.

  12. A Boundary Element Solution to the Problem of Interacting AC Fields in Parallel Conductors

    Directory of Open Access Journals (Sweden)

    Einar M. Rønquist

    1984-04-01

    Full Text Available The ac fields in electrically insulated conductors will interact through the surrounding electromagnetic fields. The pertinent field equations reduce to the Helmholtz equation inside each conductor (interior problem, and to the Laplace equation outside the conductors (exterior problem. These equations are transformed to integral equations, with the magnetic vector potential and its normal derivative on the boundaries as unknowns. The integral equations are then approximated by sets of algebraic equations. The interior problem involves only unknowns on the boundary of each conductor, while the exterior problem couples unknowns from several conductors. The interior and the exterior problem are coupled through the field continuity conditions. The full set of equations is solved by standard Gaussian elimination. We also show how the total current and the dissipated power within each conductor can be expressed as boundary integrals. Finally, computational results for a sample problem are compared with a finite difference solution.

  13. Classical Properties of Low-Dimensional Conductors: Giant Capacitance and Non-Ohmic Potential Drop

    OpenAIRE

    Korenblum, Boris; Rashba, Emmanuel

    2002-01-01

    Electrical field arising around an inhomogeneous conductor when an electrical current passes through it is not screened, as distinct from 3D conductors, in low-dimensional conductors. As a result, the electrical field depends on the global distribution of the conductivity sigma(x) rather than on the local value of it, inhomogeneities of sigma(x) produce giant capacitances C(omega) that show frequency dependence at relatively low omega, and electrical fields develop in vast regions around the ...

  14. New Al-Ag Alloys for Electrical Conductors with Increased Current Carrying Capacity

    Directory of Open Access Journals (Sweden)

    Mamala A.

    2016-12-01

    Full Text Available The paper shows a new idea of aluminium alloys. New alloys with specially selected alloying element i.e. silver have electrical conductivity similar to pure aluminium at ambient temperature and better than pure aluminium electrical conductivity at increased temperatures. Al-Ag alloys for electrical applications (mainly for electrical conductors due to high electrical conductivity at increased temperatures at the level of the maximum conductor working temperatures give possibility of better current capacity of conductors.

  15. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  16. Magnetohydrodynamic perturbations arising in metallic conductors under the action of the discharge current

    Science.gov (United States)

    Surkaev, A. L.

    2015-07-01

    The presence of radial and axial mechanical perturbations in metallic conductors (cylinders and flat plates) arising under the action of a nanosecond discharge current are proved experimentally. The amplitude of the mechanical perturbations in solid-state conductors oscillates. The radial component of the mechanical perturbation should be considered as a reason for a magnetohydrodynamic instability with mode m = 0 and, accordingly, for the formation of strata at the electrical explosion of the conductor. Data for the electrical explosion of the metallic cylindrical conductor and flat metal sheet (foil) are presented.

  17. Investigation of the influence of heat transfer on screen printed textile conductor

    Science.gov (United States)

    Kazani, I.; De Mey, G.; Hertleer, C.; Guxho, G.; Van Langenhove, L.

    2017-10-01

    Two different textile substrates were screen printed with silver-based inks in order to be electrically conductive. In every textile four conductors were printed with different widths in order to investigate the influence of heat transfer on each conductor. This was done, by using the thermo graphic camera and through the evaluation of each conductor’s profile. It was found that the conductors printed on the white textile had higher values of heat transfer compared to the other conductors printed on the dark textiles.

  18. Virus Assemblies as Templates for Nanocircuits

    Energy Technology Data Exchange (ETDEWEB)

    James N Culver; Michael T Harris

    2011-08-31

    The goals of this project were directed at the identification and characterization of bio-mineralization processes and patterning methods for the development of nano scale materials and structures with novel energy and conductive traits. This project utilized a simple plant virus as a model template to investigate methods to attach and coat metals and other inorganic compounds onto biologically based nanotemplates. Accomplishments include: the development of robust biological nanotemplates with enhanced inorganic coating activities; novel coating strategies that allow for the deposition of a continuous inorganic layer onto a bio-nanotemplate even in the absence of a reducing agent; three-dimensional patterning methods for the assemble of nano-featured high aspect ratio surfaces and the demonstrated use of these surfaces in enhancing battery and energy storage applications. Combined results from this project have significantly advanced our understanding and ability to utilize the unique self-assembly properties of biologically based molecules to produce novel materials at the nanoscale level.

  19. Neuronal recordings with solid-conductor intracellular nanoelectrodes (SCINEs).

    Science.gov (United States)

    Angle, Matthew R; Schaefer, Andreas T

    2012-01-01

    Direct electrical recording of the neuronal transmembrane potential has been crucial to our understanding of the biophysical mechanisms subserving neuronal computation. Existing intracellular recording techniques, however, limit the accuracy and duration of such measurements by changing intracellular biochemistry and/or by damaging the plasma membrane. Here we demonstrate that nanoengineered electrodes can be used to record neuronal transmembrane potentials in brain tissue without causing these physiological perturbations. Using focused ion beam milling, we have fabricated Solid-Conductor Intracellular NanoElectrodes (SCINEs), from conventional tungsten microelectrodes. SCINEs have tips that are neuroscience.

  20. Magnet and conductor developments for the Mirror Fusion Program

    Energy Technology Data Exchange (ETDEWEB)

    Cornish, D.N.

    1981-10-09

    The conductor development and the magnet design and construction for the MFTF are described. Future plans for the Mirror Program and their influence on the associated superconductor development program are discussed. Included is a summary of the progress being made to develop large, high-field, multifilamentary Nb/sub 3/Sn superconductors and the feasibility of building a 12-T yin-yang set of coils for the machine to follow MFTF. In a further look into the future, possible magnetic configurations and requirements for mirror reactors are surveyed.

  1. Stretchable conductors by kirigami patterning of aramid-silver nanocomposites with zero conductance gradient

    Science.gov (United States)

    Lyu, Jing; Hammig, Mark D.; Liu, Lehao; Xu, Lizhi; Chi, Hang; Uher, Ctirad; Li, Tiehu; Kotov, Nicholas A.

    2017-10-01

    Materials that are both stretchable and electrically conductive enable a broad spectrum of applications in sensing, actuating, electronics, optics and energy storage. The materials engineering concept of stretchable conductors is primarily based on combining nanowires, nanoribbons, nanoparticles, or nanocarbons with rubbery polymers to obtain composites with different abilities to transport charge and alter their nanoscale organization under strain. Although some of these composites reveal remarkably interesting multiscale reconfigurability and self-assembly phenomena, decreasing conductance with increased strain has restricted their widespread implementation. In a broader physical sense, the dependence of conductance on stress is undesirable because it requires a correlated change of electrical inputs. In this paper, we describe highly conductive and deformable sheets with a conductivity as high as 230 000 S cm-1, composed of silver nanoparticles, infiltrated within a porous aramid nanofiber (ANF) matrix. By forming a kirigami pattern, consisting of a regularized network of notches cut within the films, their ultimate tensile strain is improved from ˜2% to beyond 100%. The use of ANFs derived from well-known ultrastrong Kevlar™ fibers imparts high mechanical performance to the base composite. Importantly, the conductance of the films remains constant, even under large deformation resulting in a material with a zero conductance gradient. Unlike other nanocomposites for which strain and conductance are strongly coupled, the kirigami nanocomposite provides a pathway to demanding applications for flexible and stretchable electronics with power/voltage being unaffected by the deformation mode and temperature.

  2. Three-Dimensional Flexible All-Organic Conductors for Multifunctional Wearable Applications.

    Science.gov (United States)

    Moon, In Kyu; Yoon, Seonno; Lee, Hee Uk; Kim, Seung Wook; Oh, Jungwoo

    2017-11-22

    Wearable textile electrodes based on π-conjugated polymers are appealing alternatives to carbon fabrics, conductive yarns, or metal wires because of their design flexibility, low cost, flexibility, and high throughput. This provides the benefits of both electronics and textiles. Herein, a general and new method has been developed to produce tailorable, wearable energy devices that are based on three-dimensional (3D) poly(3,4-ethylenedioxythiophene) (PEDOT)-coated textile conductors. To obtain the desired electrode materials, both facile solution-dropping polymerization methods are used to fabricate a 3D flexible PEDOT conductor on a cotton textile (PEDOT/textile). PEDOT/textile shows a very low sheet resistance of 4.6-4.9 Ω·sq-1. Here, we employ the example of this 3D network-like structure and the excellent electrical conductivities under the large deformation of PEDOT/textiles to show that wearable and portable heaters have immense potential. A flexible textile heater with a large area (8 × 7.8 cm2) reached a saturation temperature of ∼83.9 °C when a bias of 7 V was applied for ∼70 s due to the good electrical conductivity of PEDOT. To demonstrate the performance of all-solid-state supercapacitors, nano-ascidian-like PEDOT (PEDOT-NA) arrays were prepared via a simple vapor-phase polymerization of 3,4-ethylenedioxythiophene on PEDOT/textile to increase both the surface area and the number of ion diffusion paths. The PEDOT-NA arrays on PEDOT/textile showed outstanding performance with an areal capacitance of 563.3 mF·cm-2 at 0.4 mA·cm-2 and extraordinary mechanical flexibility. The maximum volumetric power density and energy density of the nanostructured PEDOT on the textile were 1.75 W·cm-3 and 0.0812 Wh·cm-3, respectively. It is expected that the wearable nanostructured conducting polymers will have advantages when used as structures for smart textronics and energy conversion/storage.

  3. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... the investigative tools offered by assemblage theory, actor-network theory and non-representational theory. Clear theoretical explanation and methodological innovation, alongside empirical applications of these emerging frameworks will offer readers new and refreshing perspectives on consumer culture and market...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....

  4. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Intense UV photoluminescence is observed for intrinsic ZnO film. Keywords : thin films, oxidize zinc doped aluminium (ZnO:Al), sol-gel, spin coating, structural analysis, electric and optical properties. 1. Introduction. Depuis ces vingt dernières années les couches minces d'oxyde de zinc ont connu un intérêt croissant dans ...

  5. Silver nanoprisms self-assembly on differently functionalized silica surface

    Science.gov (United States)

    Pilipavicius, J.; Chodosovskaja, A.; Beganskiene, A.; Kareiva, A.

    2015-03-01

    In this work colloidal silica/silver nanoprisms (NPRs) composite coatings were made. Firstly colloidal silica sols were synthesized by sol-gel method and produced coatings on glass by dip-coating technique. Next coatings were silanized by (3-Aminopropyl)triethoxysilane (APTES), N-[3-(Trimethoxysilyl)propyl]ethylenediamine (AEAPTMS), (3- Mercaptopropyl)trimethoxysilane (MPTMS). Silver NPRs where synthesized via seed-mediated method and high yield of 94±15 nm average edge length silver NPRs were obtained with surface plasmon resonance peak at 921 nm. Silica-Silver NPRs composite coatings obtained by selfassembly on silica coated-functionalized surface. In order to find the most appropriate silanization way for Silver NPRs self-assembly, the composite coatings were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), water contact angle (CA) and surface free energy (SFE) methods. Results have showed that surface functionalization is necessary to achieve self-assembled Ag NPRs layer. MPTMS silanized coatings resulted sparse distribution of Ag NPRs. Most homogeneous, even distribution composite coatings obtained on APTES functionalized silica coatings, while AEAPTMS induced strong aggregation of Silver NPRs.

  6. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  7. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  8. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  9. General Assembly

    CERN Multimedia

    Staff Association

    2017-01-01

    Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 avril 2016. Présentation et approbation du rapport d’activités 2016. Présentation et approbation du rapport financier 2016. Présentation et approbation du rapport des vérificateurs aux comptes pour 2016. Programme de travail 2017. Présentation et approbation du projet de budget 2017 Approbation du taux de cotisation pour 2018. Modifications aux Statuts de l'Association du personnel proposées. Élections des membres de la Commission électorale. Élections des vérifica...

  10. Mechanical characterization and assessment of the CMS conductor

    CERN Document Server

    Sequeira-Lopes-Tavares, S; Desirelli, Alberto; Sgobba, Stefano; Horváth, I L

    2000-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.5m and the free aperture is 6 m in diameter. This is achieved with a 4 layer and 5 module superconducting Al stabilized coil, resulting into 20 lengths of conductor of 2.5 km each, energized at a nominal current of 20 kA at 4.5 K. One of the unique features of this thin solenoid is an Al-stabilized conductor reinforced by an Al-alloy. An extensive characterization of mechanical properties at room temperature and 4.2 K has been carried out in order to define the most appropriate alloy and temper for the reinforcement. The effect of the coil curing cycle on the alloy properties has been taken into account. This paper summarizes the main results of these tests. (7 refs).

  11. Mutual capacitance of liquid conductors in deformable tactile sensing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin [Electrical and Computer Engineering Department, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Fontecchio, Adam K. [Electrical and Computer Engineering and Materials Science and Engineering Departments, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Visell, Yon [Electrical and Computer Engineering Department, Media Arts and Technology, California NanoSystems Institute, University of California, Santa Barbara, California 93106 (United States)

    2016-01-04

    Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.

  12. Amorphous carbon interlayers for gold on elastomer stretchable conductors

    Energy Technology Data Exchange (ETDEWEB)

    Manzoor, M U; Tuinea-Bobe, C L; McKavanagh, F; Byrne, C P; Dixon, D; Maguire, P D; Lemoine, P, E-mail: Manzoor-m@email.ulster.ac.uk [NIBEC, University of Ulster at Jordanstown, Shore Road, Newtownabbey, Co. Antrim, BT37 0QB, Northern Ireland (United Kingdom)

    2011-06-22

    Gold on polydimethylsiloxane (PDMS) stretchable conductors were prepared using a novel approach by interlacing an hydrogenated amorphous carbon (a-C : H) layer between the deposited metal layer and the elastomer. AFM analysis of the a-C : H film surface before gold deposition shows nanoscale buckling, the corresponding increase in specific surface area corresponds to a strain compensation for the first 4-6% of bi-axial tensile loading. Without this interlayer, the deposited gold films show much smaller and uni-directional ripples as well as more cracks and delaminations. With a-C : H interlayer, the initial electrical resistivity of the metal film decreases markedly (280-fold decrease to 8 x 10{sup -6} {Omega} cm). This is not due to conduction within the carbon interlayer; both a-C : H/PDMS and PDMS substrates are electrically insulating. Upon cyclic tensile loading, both films become more resistive, but return to their initial state after 20 tensile cycles up to 60% strain. Profiling experiments using secondary ion mass spectroscopy and x-ray photoelectron spectroscopy indicate that the a-C : H layer intermixes with the PDMS, resulting in a graded layer of decreasing stiffness. We believe that both this graded layer and the surface buckling contribute to the observed improvement in the electrical performance of these stretchable conductors.

  13. A Na(+) Superionic Conductor for Room-Temperature Sodium Batteries.

    Science.gov (United States)

    Song, Shufeng; Duong, Hai M; Korsunsky, Alexander M; Hu, Ning; Lu, Li

    2016-08-30

    Rechargeable lithium ion batteries have ruled the consumer electronics market for the past 20 years and have great significance in the growing number of electric vehicles and stationary energy storage applications. However, in addition to concerns about electrochemical performance, the limited availability of lithium is gradually becoming an important issue for further continued use and development of lithium ion batteries. Therefore, a significant shift in attention has been taking place towards new types of rechargeable batteries such as sodium-based systems that have low cost. Another important aspect of sodium battery is its potential compatibility with the all-solid-state design where solid electrolyte is used to replace liquid one, leading to simple battery design, long life span, and excellent safety. The key to the success of all-solid-state battery design is the challenge of finding solid electrolytes possessing acceptable high ionic conductivities at room temperature. Herein, we report a novel sodium superionic conductor with NASICON structure, Na3.1Zr1.95Mg0.05Si2PO12 that shows high room-temperature ionic conductivity of 3.5 × 10(-3) S cm(-1). We also report successful fabrication of a room-temperature solid-state Na-S cell using this conductor.

  14. A Na+ Superionic Conductor for Room-Temperature Sodium Batteries

    Science.gov (United States)

    Song, Shufeng; Duong, Hai M.; Korsunsky, Alexander M.; Hu, Ning; Lu, Li

    2016-08-01

    Rechargeable lithium ion batteries have ruled the consumer electronics market for the past 20 years and have great significance in the growing number of electric vehicles and stationary energy storage applications. However, in addition to concerns about electrochemical performance, the limited availability of lithium is gradually becoming an important issue for further continued use and development of lithium ion batteries. Therefore, a significant shift in attention has been taking place towards new types of rechargeable batteries such as sodium-based systems that have low cost. Another important aspect of sodium battery is its potential compatibility with the all-solid-state design where solid electrolyte is used to replace liquid one, leading to simple battery design, long life span, and excellent safety. The key to the success of all-solid-state battery design is the challenge of finding solid electrolytes possessing acceptable high ionic conductivities at room temperature. Herein, we report a novel sodium superionic conductor with NASICON structure, Na3.1Zr1.95Mg0.05Si2PO12 that shows high room-temperature ionic conductivity of 3.5 × 10-3 S cm-1. We also report successful fabrication of a room-temperature solid-state Na-S cell using this conductor.

  15. High vacuum tribology of polycrystalline diamond coatings

    Indian Academy of Sciences (India)

    Coating surfaces with PCD offers exciting possibilities of substantially reducing the wear and possibly the friction of the critical moving mechanical assemblies. There are several mechanisms of friction proposed by different authors for diamond films. Gardos (1994, 1999) through his research over decades has proposed that ...

  16. Issues relating to representation of multiple conductors for a conductor equivalent: proposal for a model that takes into account the current distribution among semiconductor beam; Aspectos referentes a representaco de condutores multiplos por um condutor equivalente: proposta de um modelo que leva em conta a distribuicao da corrente entre os subcondutores do feixe

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, S.; Costa, E.C.M.; Prado, A.J.; Bovolato, L.F. [Universidade Estadual Paulista (FEIS/UNESP), Ilha Solteira, SP (Brazil). Fac. de Engenharia], Emails: kurokawa@dee.feis.unesp.br, edumarquescosta@hotmail.com, afonsojp@uol.com.br, bovolato@dee.feis.unesp.br; Pissolato, J. [Universidade Estadual de Campinas (FEEC/UNICAMP), SP (Brazil). Fac. de Engenharia Eletrica e de Computacao], E-mail: pisso@dsce.fee.unicamp.br

    2009-07-01

    In a traditional multiple conductors, the sub-conductors are identical and are separated by a small distance. Based on this fact it is possible to say that currents that run through the sub-conductors are approximately equal, allowing the representation of a multiple conductor as a single conductor whose radius is equal to the geometric mean radius of the sub-conductors that is in the geometric center of the beam. The possibility of emergence of new configurations to multiple conductors, where is not possible to consider that the current is distributed equally among all sub-conductors, led the authors to propose an alternative method for calculating the parameters of the equivalent conductor taking into account the actual distribution of current between the sub-conductors. The method was applied to a typical beam where sub-conductors are equal and also in a multiple conductor in which the sub-conductors are different.

  17. Researches of peak analog modulation of semi-conductor lasers in view of effects of ageing

    Directory of Open Access Journals (Sweden)

    В.І. Олійник

    2004-04-01

    Full Text Available  Are investigated amplitude - frequency characteristics of injection semi-conductor lasers. Measurements of factors of nonlinear distortions and depths of peak modulation of such lasers in a current mode the microwave modulation are executed. Experimental researches are carried out  with use of semi-conductor lasers after their long warehousing modeling effects of ageing.

  18. Synthesis and Characterization of Ethylenedithio-MPTTF-PTM Radical Dyad as a Potential Neutral Radical Conductor

    DEFF Research Database (Denmark)

    Souto, Manuel; Bendixen, Dan; Jensen, Morten

    2016-01-01

    During the last years there has been a high interest in the development of new purely-organic single-component conductors. Very recently, we have reported a new neutral radical conductor based on the perchlorotriphenylmethyl (PTM) radical moiety linked to a monopyrrolo-tetrathiafulvalene (MPTTF...

  19. First resultst of AC loss test on ITER TF conductors with transverse load cycling

    NARCIS (Netherlands)

    Miyoshi, Y.; Rolando, G.; Nijhuis, Arend; Vostner, A.; Nabara, Y.

    2012-01-01

    The influence of the expected Lorentz loading and time dependent operating conditions of a magnet on the conductor AC loss is experimentally simulated by a cryogenic cable press that applies cyclic mechanical loading. A series of ITER conductor tests with the press have commenced and we report on

  20. The Virtual Conductor: Learning and Teaching about Music, Performing, and Conducting

    NARCIS (Netherlands)

    Nijholt, Antinus; Reidsma, Dennis; Ebbers, Rob; ter Maat, Mark

    2008-01-01

    The Virtual Conductor is an artificial conducting system for tutoring purposes that uses real-time audio analysis of music played by musicians and uses this analysis to animate a virtual human that acts as a conductor. The analysis detects the tempo and the dynamics of the music, compares the

  1. Thin magnetic conductor substrate for placement-immune, electrically-small antennas.

    Energy Technology Data Exchange (ETDEWEB)

    Eubanks, Travis Wayne; McDonald, Jacob J.; Loui, Hung

    2011-09-01

    An antenna is considered to be placement-immune when the antenna operates effectively regardless of where it is placed. By building antennas on magnetic conductor materials, the radiated fields will be positively reinforced in the desired radiation direction instead of being negatively affected by the environment. Although this idea has been discussed thoroughly in theoretical research, the difficulty in building thin magnetic conductor materials necessary for in-phase field reflections prevents this technology from becoming more widespread. This project's purpose is to build and measure an electrically-small antenna on a new type of non-metallic, thin magnetic conductor. This problem has not been previously addressed because non-metallic, thin magnetic conductor materials have not yet been discovered. This work proposed the creation of an artificial magnetic conductor (AMC) with in-phase field reflections without using internal electric conductors, the placement of an electrically-small antenna on this magnetic conductor, and the development of a transmit-receive system that utilizes the substrate and electrically-small antenna. By not using internal electric conductors to create the AMC, the substrate thickness can be minimized. The electrically-small antenna will demonstrate the substrate's ability to make an antenna placement immune, and the transmit-receive system combines both the antenna and the substrate while adding a third layer of system complexity to demonstrate the complete idea.

  2. A Systematic Inventory of Motives for Becoming an Orchestra Conductor: A Preliminary Study

    Science.gov (United States)

    Makris, Ioannis; Mullet, Etienne

    2009-01-01

    The study examined the various motives (reasons) that may have led an individual to become an orchestra conductor interpreting classical works, using Apter's (2001) Metamotivational Theory framework. Questionnaires derived from the theory, consisting of 92 possible motives for becoming an orchestra conductor, were presented to 101 orchestra…

  3. 30 CFR 75.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding metallic sheaths, armors, and conduits enclosing power conductors. 75.700 Section 75.700 Mineral Resources MINE SAFETY AND HEALTH... Grounding § 75.700 Grounding metallic sheaths, armors, and conduits enclosing power conductors. All metallic...

  4. 30 CFR 75.1002 - Installation of electric equipment and conductors; permissibility.

    Science.gov (United States)

    2010-07-01

    ... Wires and Trolley Feeder Wires § 75.1002 Installation of electric equipment and conductors... equipment is located within 150 feet of pillar workings or longwall faces. (b) Electric conductors and... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of electric equipment and...

  5. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Science.gov (United States)

    2010-07-01

    ... power conductors and telephone wires. 77.508 Section 77.508 Mineral Resources MINE SAFETY AND HEALTH... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.508 Lightning arresters, ungrounded and exposed power conductors and telephone wires. All ungrounded, exposed power...

  6. An experimental method to determine the electrostatic field enhancement factor of a practical conductor surface

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson; Crichton, George C

    1989-01-01

    A method of determining the field enhancement factor of a practical conductor is presented. The method is developed from a modified theory of discharge onset in a gaseous medium. This modification incorporates the influence of conductor surface roughness. Onset data from an experimental study...

  7. Measuring ac-loss in high temperature superconducting cable-conductors using four probe methods

    DEFF Research Database (Denmark)

    Kühle (fratrådt), Anders Van Der Aa; Træholt, Chresten; Olsen, Søren Krüger

    1999-01-01

    Measuring the ac-loss of superconducting cable conductors have many aspects in common with measuring the ac-loss of single superconducting tapes. In a cable conductor all tapes are connected to each other and to the test circuit through normal metal joints in each end. This makes such measurements...

  8. Design-Based Research as an Informal Learning Model for Choral Conductors

    Science.gov (United States)

    Cooper, Naomi

    2017-01-01

    The number of community choirs continues to grow, and literature endorsing the benefits of choral singing for physical, mental and emotional health and well-being is rapidly expanding, meaning that the professional development of community choral conductors is in the public interest. However, research on choral conductor education remains limited.…

  9. Conductor design of CS and EF coils for JT-60SA

    Energy Technology Data Exchange (ETDEWEB)

    Kizu, K.; Tsuchiya, K.; Yoshida, K.; Edaya, M.; Ichige, T.; Tamai, H.; Matsukawa, M. [Japan Atomic Energy Agency, Ibaraki 311-0193, (Japan); Della Corte, A.; Di Zenobio, A.; Muzzi, L.; Turtu, S. [EURATOM-ENEA Assoc., 00044 Frascati, Rome, (Italy); Duchateau, J.L.; Zani, L. [CEA Cadarache, DSM, DRFC, EURATOM-CEA Assoc., F-13108 Saint Paul lez Durance, (France)

    2008-07-01

    The conductor for central solenoid (CS) and equilibrium field (EF) coils of JT-60 Super Advanced (JT-60SA) were designed. The conductor for CS is Nb{sub 3}Sn Cable-In-Conduit (CIC) conductor with JK2LB jacket. EF coil conductors are NbTi CIC conductor with SS316LN jacket. The field change rate (3.9 T/s), faster than ITER generates the large AC loss in conductor. The analyses of current sharing temperature (T{sub cs}) margins for these coils were performed by the one-dimensional fluid analysis code with transient heat loads. The T{sub cs} margins of these coils are {>=} 1 K for the plasma standard and disruption scenarios. The minimum T,, margin of CS conductor is 1.2 K at plasma break down (BD). The margin is increased by decreasing the rate of initial magnetization. It is found that the disruption mainly impacts the outer low field EF coil. The disruption decreases the T{sub cs} margin of the coil by {>=}1 K. A coupling time constant of {<=} 100 ms, Ni plating, and a central spiral are required for NbTi conductor. (authors)

  10. AC loss characteristics of simulated CIC-type conductors having plastic conduit

    Science.gov (United States)

    Kojo, Y.; Sekine, N.; Tada, S.; Yamaguchi, Y.; Obama, J.; Takao, T.; Miyagi, D.; Yamanaka, A.

    2003-10-01

    When alternating current superconducting coils having cable-in-conduit conductors are fabricated, non-metallic conduit materials are necessary to avoid eddy current losses in the conduits. Using two kinds of non-metallic tapes made of glass fiber reinforced plastics (GFRPs) and Dyneema fiber reinforced plastics (DFRPs), we made the conductors with the GFRP conduits and DFRP conduits, and experimentally studied the total losses of the conductors. The measured results showed that the total loss of the conductor with the GFRP conduit was smaller than that with the DFRP conduit at the same value of the void ratio, the transport current, the external magnetic field, and so on. When the void ratios become high, the superconducting bundle cable can easily move in the conduit. Hence the measured total losses increased with the void ratios of the conductors.

  11. AC loss characteristics of simulated CIC-type conductors having plastic conduit

    Energy Technology Data Exchange (ETDEWEB)

    Kojo, Y.; Sekine, N.; Tada, S.; Yamaguchi, Y.; Obama, J.; Takao, T.; Miyagi, D.; Yamanaka, A

    2003-10-15

    When alternating current superconducting coils having cable-in-conduit conductors are fabricated, non-metallic conduit materials are necessary to avoid eddy current losses in the conduits. Using two kinds of non-metallic tapes made of glass fiber reinforced plastics (GFRPs) and Dyneema fiber reinforced plastics (DFRPs), we made the conductors with the GFRP conduits and DFRP conduits, and experimentally studied the total losses of the conductors. The measured results showed that the total loss of the conductor with the GFRP conduit was smaller than that with the DFRP conduit at the same value of the void ratio, the transport current, the external magnetic field, and so on. When the void ratios become high, the superconducting bundle cable can easily move in the conduit. Hence the measured total losses increased with the void ratios of the conductors.

  12. Wind Tunnel Tests on Aerodynamic Characteristics of two types of Iced Conductors with Elastic Support

    Science.gov (United States)

    Yi, You; Cheng, He; Xinxin, Wang

    2018-01-01

    The wind tunnel tests were carried out to obtain the variation laws of static aerodynamic characteristics of crescent and D-shape iced conductor with different wind velocities, wind attack angles and torsional elastic support stiffness. Test results show that the variation of wind velocity has a relatively large influence on the aerodynamic coefficients of crescent conductor with torsional elastic support 1. However, the influence on that of D-shape conductor is not obvious. With the increase of the torsional elastic support stiffness, the lift and moment coefficient curves of the crescent iced conductor form an obvious peak phenomenon in the range of 0 ° ∼30°. Meanwhile, the wind attack angle position corresponding to the maximum value of the lift and moment coefficients of the D-shape iced conductor appear a backward moving phenomenon.

  13. Testing Short Samples of ITER Conductors and Projection of Their Performance in ITER Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, N N

    2007-08-20

    Qualification of the ITER conductor is absolutely necessary. Testing large scale conductors is expensive and time consuming. To test straight 3-4m long samples in a bore of a split solenoid is a relatively economical way in comparison with fabrication of a coil to be tested in a bore of a background field solenoid. However, testing short sample may give ambiguous results due to different constraints in current redistribution in the cable or other end effects which are not present in the large magnet. This paper discusses processes taking place in the ITER conductor, conditions when conductor performance could be distorted and possible signal processing to deduce behavior of ITER conductors in ITER magnets from the test data.

  14. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Dans ce travail nous avons préparé des couches minces de l'oxyde de zinc ZnO dopées à l'aluminium et non dopées par la technique Sol-Gel associée au « spin coating » sur des substrats en verre « pyrex » à partir de l'acétate de zinc dissous dans une solution de l'éthanol. Nous avons ensuite effectué des analyses ...

  15. Ni-Al composite coatings: Diffusion analysis and coating lifetime estimation

    Energy Technology Data Exchange (ETDEWEB)

    SUSAN,DONALD F.; MARDER,A.R.

    2000-05-09

    The interdiffusion of Ni matrix/Al particle composite coatings and nickel substrates was studied using electron probe microanalysis (EPMA) and a one-dimensional diffusion model. The initial coating microstructure was a two-phase mixture of y(Ni) and y{prime}(Ni{sub 3}Al). The coating/substrate assemblies were aged at 800 to 1,100 C for times up to 2,000 hours. It was found that aluminum losses to the substrate are significant at 1,000 C and above. The experimental results for the diffusion of Al into the substrate were compared to model predictions based on a diffusion equation for a finite layer on an infinite substrate. Using combined experimental and model results, the effects of temperature and coating thickness were determined and a rationale was developed for coating lifetime prediction.

  16. Characterization of a strongly textured non-ferromagnetic Cu-33 at%Ni substrate coated with a CeO2 buffer layer

    DEFF Research Database (Denmark)

    Tian, Hui; Suo, H.L.; Yue, Zhao

    2013-01-01

    the fraction of the cube {001}〈100〉 texture is 99.8% and the fraction of boundary misorientations with angles greater than 10 is only 5%. The material is shown to be non-ferromagnetic at typical operating temperatures for coated conductors. Furthermore, it is shown that a CeO2 buffer layer can be successfully...

  17. Polysulfide flow batteries enabled by percolating nanoscale conductor networks.

    Science.gov (United States)

    Fan, Frank Y; Woodford, William H; Li, Zheng; Baram, Nir; Smith, Kyle C; Helal, Ahmed; McKinley, Gareth H; Carter, W Craig; Chiang, Yet-Ming

    2014-01-01

    A new approach to flow battery design is demonstrated wherein diffusion-limited aggregation of nanoscale conductor particles at ∼1 vol % concentration is used to impart mixed electronic-ionic conductivity to redox solutions, forming flow electrodes with embedded current collector networks that self-heal after shear. Lithium polysulfide flow cathodes of this architecture exhibit electrochemical activity that is distributed throughout the volume of flow electrodes rather than being confined to surfaces of stationary current collectors. The nanoscale network architecture enables cycling of polysulfide solutions deep into precipitation regimes that historically have shown poor capacity utilization and reversibility and may thereby enable new flow battery designs of higher energy density and lower system cost. Lithium polysulfide half-flow cells operating in both continuous and intermittent flow mode are demonstrated for the first time.

  18. Intermediate Temperature Proton Conductors – Why and How

    DEFF Research Database (Denmark)

    Li, Qingfeng; Aili, David; Jensen, Jens Oluf

    represented by early fundamental material research for ionic electrolytes. Such materials, most likely based on proton conductors, are expected to bring a new generation of the technologies: fuel cells by direct oxidation or internal splitting of biofuels such as methanol and ethanol, as well as efficient...... water electrolyzer, preferrably a CO2 co-electrolyzer for generation of organic liquid fuels. Such technologies are of essential simplicity and allow for kinetic enhancement so that the need for precious metal catalysts as in low temperature systems might be eliminated. At the same time......The current technologies of fuel cells and electrolzers are based on ionic conducting electrolyte materials exclusively operational either in the low (20 - 200ºC) or high (600 - 1000ºC) temperature ranges. The intermediate temperature window, especially between 200 and 400 ºC, is still only...

  19. Magnetotransport phenomena in layered conductors under magnetic breakdown

    Science.gov (United States)

    Galbova, O.; Peschansky, V. G.; Stepanenko, D. I.

    2017-06-01

    We study the transport phenomena in layered conductors with rather general electron energy spectrum placed in a high magnetic field H, under conditions when the distance between various sheets of the Fermi surface (FS) may become small under the external effects, such as hydrostatic pressure or impurity atom doping, and electrons can transfer from one sheet of the FS to another due to magnetic breakdown. We calculate the dependence of the in-plane electrical conductivity and magnetoresistance on magnetic field and probability of magnetic breakdown and show that the field-induced quadratic increase of the in-plane resistance in the absence of magnetic breakdown is changed by a linear dependence on H. With a further reduction of the energy gap between FS sheets, the in-plane resistance is saturated.

  20. Admittance of multiterminal quantum Hall conductors at kilohertz frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, C. [Departamento de Física, Universidad Militar Nueva Granada, Carrera 11 101-80 Bogotá D.C. (Colombia); Consejo, C.; Chaubet, C., E-mail: christophe.chaubet@univ-montp2.fr [Université Montpellier 2, Laboratoire Charles Coulomb UMR5221, F-34095 Montpellier, France and CNRS, Laboratoire Charles Coulomb UMR5221, F-34095 Montpellier (France); Degiovanni, P. [Université de Lyon, Fédération de Physique Andrée Marie Ampère, CNRS, Laboratoire de Physique de l' Ecole Normale Supérieure de Lyon, 46 allée d' Italie, 69364 Lyon Cedex 07 (France)

    2014-03-28

    We present an experimental study of the low frequency admittance of quantum Hall conductors in the [100 Hz, 1 MHz] frequency range. We show that the frequency dependence of the admittance of the sample strongly depends on the topology of the contacts connections. Our experimental results are well explained within the Christen and Büttiker approach for finite frequency transport in quantum Hall edge channels taking into account the influence of the coaxial cables capacitance. In the Hall bar geometry, we demonstrate that there exists a configuration in which the cable capacitance does not influence the admittance measurement of the sample. In this case, we measure the electrochemical capacitance of the sample and observe its dependence on the filling factor.

  1. Investigations of Carbon Nanotube Networks for use as Transparent Conductors

    Science.gov (United States)

    Topinka, Mark

    2006-03-01

    Recently there has been increasing interest in the physics of conduction through carbon nanotube networks and the possibility of using carbon nanotube networks as transparent conducting layers for solar cells and other optoelectronic applications(1). Conductivities as high as 30 ohm/square with transparencies of about 80% have been reported(2). Here we present results of our work on understanding the underlying physics behind the real-world behavior of these systems and identifying the bottlenecks which are currently limiting their performance. We focus in particular on their possible use in solar cells as a low-cost alternative to more expensive transparent conductor technologies such as Indium Tin Oxide (ITO). We include numerical simulations of conduction through nanotube networks and scanning probe microscopy studies of transport through these systems. (1) L.Hu, D.S.Hecht, G.Gruner, NanoLetters 4, 2513 (2) Z.Wu, et al, Science 305, 1273

  2. Fuel-Cell Electrolytes Based on Organosilica Hybrid Proton Conductors

    Science.gov (United States)

    Narayan, Sri R.; Yen, Shiao-Pin S.

    2008-01-01

    A new membrane composite material that combines an organosilica proton conductor with perfluorinated Nafion material to achieve good proton conductivity and high-temperature performance for membranes used for fuel cells in stationary, transportation, and portable applications has been developed. To achieve high proton conductivities of the order of 10(exp -1)S/cm over a wide range of temperatures, a composite membrane based on a new class of mesoporous, proton-conducting, hydrogen-bonded organosilica, used with Nafion, will allow for water retention and high proton conductivity over a wider range of temperatures than currently offered by Nafion alone. At the time of this reporting, this innovation is at the concept level. Some of the materials and processes investigated have shown good proton conductivity, but membranes have not yet been prepared and demonstrated.

  3. Mixed conductor anodes: Ni as electrocatalyst for hydrogen conversion

    DEFF Research Database (Denmark)

    Primdahl, S.; Mogensen, Mogens Bjerg

    2002-01-01

    (0.6)Gd(0.4)O(1.8) (CG4) ceramic, a La(0.75)Sr(0.25)Cr(0.97)V(0.03)O(3) (LSCV) ceramic and a Ti(0.22) Y(0.16)Zr(0.92)O(2.52) (TiYSZ) ceramic, Addition of small amounts ( approximate to I w/o) of Ni to the electrode surface is found to improve electrode performance on mixed electronic and ionic...... conductors (MIEC's), distinctly in the low-frequency part of the impedance spectra. An effect of isotope exchange (H(2)/H(2)O to D(2)/D(2)O) is observed for all anodes. The low-frequency limitation is suggested to be hydrogen adsorption and/or dissociation on the surface of MIEC electrodes, (C) 2002 Elsevier...

  4. Novel Electrically Conductive Porous PDMS/Carbon Nanofiber Composites for Deformable Strain Sensors and Conductors.

    Science.gov (United States)

    Wu, Shuying; Zhang, Jin; Ladani, Raj B; Ravindran, Anil R; Mouritz, Adrian P; Kinloch, Anthony J; Wang, Chun H

    2017-04-26

    Highly flexible and deformable electrically conductive materials are vital for the emerging field of wearable electronics. To address the challenge of flexible materials with a relatively high electrical conductivity and a high elastic limit, we report a new and facile method to prepare porous polydimethylsiloxane/carbon nanofiber composites (denoted by p-PDMS/CNF). This method involves using sugar particles coated with carbon nanofibers (CNFs) as the templates. The resulting three-dimensional porous nanocomposites, with the CNFs embedded in the PDMS pore walls, exhibit a greatly increased failure strain (up to ∼94%) compared to that of the solid, neat PDMS (∼48%). The piezoresistive response observed under cyclic tension indicates that the unique microstructure provides the new nanocomposites with excellent durability. The electrical conductivity and the gauge factor of this new nanocomposite can be tuned by changing the content of the CNFs. The electrical conductivity increases, while the gauge factor decreases, upon increasing the content of CNFs. The gauge factor of the newly developed sensors can be adjusted from approximately 1.0 to 6.5, and the nanocomposites show stable piezoresistive performance with fast response time and good linearity in ln(R/R0) versus ln(L/L0) up to ∼70% strain. The tunable sensitivity and conductivity endow these highly stretchable nanocomposites with considerable potential for use as flexible strain sensors for monitoring the movement of human joints (where a relatively high gauge factor is needed) and also as flexible conductors for wearable electronics (where a relatively low gauge factor is required).

  5. Electronic and Ionic Conductors from Ordered Microporous Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dincă, Mircea [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-10-30

    The proposed work aimed to establish metal-organic frameworks (MOFs) as new classes of high-surface area microporous electronic and ionic conductors. MOFs are crystalline materials with pore sizes ranging from 0.2 to ~ 2 nm (or larger for the latter) defined by inorganic or organic building blocks connected by rigid organic linkers. Myriad applications have been found or proposed for these materials, yet those that require electron transport or conductivity in combination with permanent porosity still lag behind because the vast majority of known frameworks are electrical insulators. Prior to our proposal and subsequent work, there were virtually no studies exploring the possibility of electronic delocalization in these materials. Therefore, our primary goal was to understand and control, at a fundamental level, the electron and ion transport properties of this class of materials, with no specific application proposed, although myriad applications could be envisioned for high surface area conductors. Our goals directly addressed one of the DOE-identified Grand Challenges for Basic Energy Sciences: designing perfect atom- and energy-efficient syntheses of revolutionary new forms of matter with tailored properties. Indeed, the proposed work is entirely synthetic in nature; owing to the molecular nature of the building blocks in MOFs, there is the possibility of unprecedented control over the structure and properties of solid crystalline matter. The goals also tangentially addressed the Grand Challenge of controlling materials processes at the level of electrons: the scope of our program is to create new materials where charges (electrons and/or ions) move according to predefined pathways.

  6. Actitudes hacia comportamientos protectores y de riesgo en conductores costarricenses

    Directory of Open Access Journals (Sweden)

    Marjorie Moreno Salas

    2011-12-01

    Full Text Available En el presente estudio se exploraron las actitudes y los comportamientos protectores y de riesgo al conducir vehículos particulares en una muestra de 590 conductores de entre 20 y 60 años (M = 38,57, DE =11,69 residentes del área metropolitana costarricense. Se realizó una investigación exploratoria, desarrollada mediante un diseño transversal con un cuestionario autoaplicado. Los principales resultados fueron que: A mayor cantidad de hijos e hijas dependientes, menores comportamientos y actitudes hacia el riesgo y mayores comportamientos protectores. A mayor cantidad de años de tener licencia, menores actitudes hacia el exceso de velocidad y menores comportamientos de riesgo asociados con la alta velocidad. Entre más días de manejo, mayores comportamientos protectores. A mayor reporte de actitudes y comportamientos favorables hacia el riesgo, menor edad de los participantes. A manera de conclusión, las actitudes y los comportamientos de riesgo se vinculan negativamente. Además, variables sociodemográficas como el número de hijos y la edad de los conductores modula la respuesta en cuanto a las actitudes y los comportamientos protectores y de riesgo al manejar. Los resultados del estudio forman un primer aporte a la investigación nacional en el tema, en tanto, se cuenta con un instrumento susceptible de ser aplicado en otros estudios y múltiples datos empíricos en la temática.

  7. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  8. The performance test and analysis of ITER Main and Correction Busbar conductor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bo, E-mail: liubo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wu, Yu; Qin, Jinggang; Long, Feng; Shi, Yi [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Bruzzone, Pierluigi; Stepanov, Boris [Centre de Recherches en Physique des Plasma, CH-5232 Villigen (Switzerland)

    2013-11-15

    The first ITER Main Busbar (MBCN1) and Correction Busbar (CBCN1) conductor samples were manufactured in ASIPP and tested in the SULTAN facility. This paper introduces the sample manufacture, including strand, cabling, jacketing and sample preparation, and discusses the performance of MBCN1 and CBCN1 conductors. The testing results show that both samples have high T{sub cs}, and meet the ITER requirement. Due to the ITER acceptance standard T{sub cs} of MB conductor was changed to 6.7 K at 45.5 kA/3.9 T. The performance of MBCN1 conductor after cyclic load fits the ITER requirement, but the sample was only tested at 57 kA/2.75 T before cycling test. Using some hypothesis and equation to extrapolate the T{sub cs} performance of MBCN1 conductor before cycling test, the result also fits the ITER requirement. For CBCN1 conductor, the central line of the central cooling spiral shifted about 1.3 mm during the cabling. The deviation causes an increase of the max self-field by about 0.005 T, which could not influence the CBCN1 conductor real T{sub cs} performance at peak field.

  9. Power System State Estimation Accuracy Enhancement Using Temperature Measurements of Overhead Line Conductors

    Directory of Open Access Journals (Sweden)

    Wydra Michał

    2016-06-01

    Full Text Available Power system state estimation is a process of real-time online modeling of an electric power system. The estimation is performed with the application of a static model of the system and current measurements of electrical quantities that are encumbered with an error. Usually, a model of the estimated system is also encumbered with an uncertainty, especially power line resistances that depend on the temperature of conductors. At present, a considerable development of technologies for dynamic power line rating can be observed. Typically, devices for dynamic line rating are installed directly on the conductors and measure basic electric parameters such as the current and voltage as well as non-electric ones as the surface temperature of conductors, their expansion, stress or the conductor sag angle relative to the plumb line. The objective of this paper is to present a method for power system state estimation that uses temperature measurements of overhead line conductors as supplementary measurements that enhance the model quality and thereby the estimation accuracy. Power system state estimation is presented together with a method of using the temperature measurements of power line conductors for updating the static power system model in the state estimation process. The results obtained with that method have been analyzed based on the estimation calculations performed for an example system - with and without taking into account the conductor temperature measurements. The final part of the article includes conclusions and suggestions for the further research.

  10. Reversible and irreversible mechanical effects in real cable-in-conduit conductors

    Science.gov (United States)

    Mitchell, N.; Devred, A.; Larbalestier, D. C.; Lee, P. J.; Sanabria, C.; Nijhuis, A.

    2013-11-01

    The strong strain sensitivity of the critical properties of Nb3Sn is well established. However, the roles played by both the reversible strain sensitivity and the susceptibility to brittle fracture of Nb3Sn filaments is still leading to unexpected results and resulting design modifications of conductors. Practical conductors require acceptance of less than perfect superconducting behaviour because such conductors actually operate continuously in a slightly resistive mode. Performance testing of the ITER conductors has provided a unique database of both strand and corresponding conductor performance. The test database includes strand characterization under uniaxial and bending strain, superconducting measurements on full-size conductor samples and microscopic investigations into filament fracture. A simple mechanical and electrical model of the strands and a multistage cable (capable of operation at 12 T and 45 kA) that focuses on predicting the imperfect superconducting behaviour is used to provide insight into the processes governing the observed conductor behaviour. The conclusions show that a short twist pitch at the first cabling stage provides the best operating conditions for the strands, and further that some strand mechanical properties, essentially a high stiffness to bending and a low stiffness to pinching, increase the ability of the strands to tolerate less well optimized cables.

  11. A Novel Method for Detection and Classification of Covered Conductor Faults

    Directory of Open Access Journals (Sweden)

    Stanislav Misak

    2016-01-01

    Full Text Available Medium-Voltage (MV overhead lines with Covered Conductors (CCs are increasingly being used around the world primarily in forested or dissected terrain areas or in urban areas where it is not possible to utilize MV cable lines. The CC is specific in high operational reliability provided by the conductor core insulation compared to Aluminium-Conductor Steel-Reinforced (ACSR overhead lines. The only disadvantage of the CC is rather the problematic detection of faults compared to the ACSR. In this work, we consider the following faults: the contact of a tree branch with a CC and the fall of a conductor on the ground. The standard protection relays are unable to detect the faults and so the faults pose a risk for individuals in the vicinity of the conductor as well as it compromises the overall safety and reliability of the MV distribution system. In this article, we continue with our previous work aimed at the method enabling detection of the faults and we introduce a method enabling a classification of the fault type. Such a classification is especially important for an operator of an MV distribution system to plan the optimal maintenance or repair the faulty conductors since the fall of a tree branch can be solved later whereas the breakdown of a conductor means an immediate action of the operator.

  12. Modeling and Mechanism of Rain-Wind Induced Vibration of Bundled Conductors

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    2016-01-01

    Full Text Available Under the certain rain-wind conditions, bundled conductors exhibit a rain-wind induced large-amplitude vibration. This type of vibration can cause the fatigue fractures of conductors and fatigue failures of spacers, which threaten the safety operation and serviceability of high-voltage transmission line. To reveal the mechanism of rain-wind induced vibration of bundled conductors, a series of 2-dimensional CFD models about the twin bundled conductors with rivulets are developed to obtain the curves of aerodynamic coefficients with the upper rivulet angle. The influences of the forward conductor’s aerodynamic shielding and the upper rivulet’s aerodynamic characteristics on the leeward conductor are discussed. Furthermore, a 2-dimensional 3DOF model for the rain-wind induced vibration of the leeward conductor is established. The model is solved by finite element method and Newmark method, and the effects of the wind velocity and the upper rivulet’s motion on vibration amplitude of the leeward conductor are analyzed. By contrast with the wake-induced vibration, it can easily find that the characteristics of rain-wind vibration are obviously different from those of the wake-induced vibration, and the main reason of the rain-induced vibration may be due to the upper rivulet’s motion.

  13. Self-assembled monolayers in organic electronics.

    Science.gov (United States)

    Casalini, Stefano; Bortolotti, Carlo Augusto; Leonardi, Francesca; Biscarini, Fabio

    2017-01-03

    Self-assembly is possibly the most effective and versatile strategy for surface functionalization. Self-assembled monolayers (SAMs) can be formed on (semi-)conductor and dielectric surfaces, and have been used in a variety of technological applications. This work aims to review the strategy behind the design and use of self-assembled monolayers in organic electronics, discuss the mechanism of interaction of SAMs in a microscopic device, and highlight the applications emerging from the integration of SAMs in an organic device. The possibility of performing surface chemistry tailoring with SAMs constitutes a versatile approach towards the tuning of the electronic and morphological properties of the interfaces relevant to the response of an organic electronic device. Functionalisation with SAMs is important not only for imparting stability to the device or enhancing its performance, as sought at the early stages of development of this field. SAM-functionalised organic devices give rise to completely new types of behavior that open unprecedented applications, such as ultra-sensitive label-free biosensors and SAM/organic transistors that can be used as robust experimental gauges for studying charge tunneling across SAMs.

  14. A parameter estimation technique for stochastic self-assembly systems and its application to human papillomavirus self-assembly

    Science.gov (United States)

    Senthil Kumar, M.; Schwartz, Russell

    2010-12-01

    Virus capsid assembly has been a key model system for studies of complex self-assembly but it does pose some significant challenges for modeling studies. One important limitation is the difficulty of determining accurate rate parameters. The large size and rapid assembly of typical viruses make it infeasible to directly measure coat protein binding rates or deduce them from the relatively indirect experimental measures available. In this work, we develop a computational strategy to deduce coat-coat binding rate parameters for viral capsid assembly systems by fitting stochastic simulation trajectories to experimental measures of assembly progress. Our method combines quadratic response surface and quasi-gradient descent approximations to deal with the high computational cost of simulations, stochastic noise in simulation trajectories and limitations of the available experimental data. The approach is demonstrated on a light scattering trajectory for a human papillomavirus (HPV) in vitro assembly system, showing that the method can provide rate parameters that produce accurate curve fits and are in good concordance with prior analysis of the data. These fits provide an insight into potential assembly mechanisms of the in vitro system and give a basis for exploring how these mechanisms might vary between in vitro and in vivo assembly conditions.

  15. Graphene Coatings

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Bøggild, Peter

    2014-01-01

    Owing to its remarkable electrical and mechanical properties, graphene has been attracting tremendous interest in materials science. In particular, its chemical stability and impermeability make it a promising protective membrane. However, recent investigations reveal that single layer graphene...... cannot be used as a barrier in the long run, due to galvanic corrosion phenomena arising when oxygen or water penetrate through graphene cracks or domain boundaries. Here, we overcome this issue by using a multilayered (ML) graphene coating. Our lab- as well as industrial-scale tests demonstrate that ML...... graphene can effectively protect Ni in harsh environments, even after long term exposure. This is made possible by the presence of a high number of graphene layers, which can efficiently mask the cracks and domain boundaries defects found in individual layers of graphene. Our findings thus show...

  16. Investigation of the pre-service science teachers' opinions about the concept of "Semi-conductor"

    Science.gov (United States)

    Eryilmaz Muştu, Özlem

    2017-02-01

    In the current study, the purpose was to determine the pre-service science teachers' opinions about the concept of semi-conductor. The participants of the current study carried out in 2015-2016 academic year were 55 third year pre-service science teachers. In the study, open-ended questions were used to determine the pre-service teachers' opinions about semi-conductors. After the administration of the open-ended questions, the students were taught the topic of semi-conductors within the lesson of special issues in physics. Then the open-ended questions were directed to the pre-service teachers again. The pre-service teachers' responses to these questions were categorized by using qualitative analysis method and their frequency values were obtained. The findings of the study revealed that the pre-service teachers had difficulties, before and after the administration of the questions, in defining semi-conductors. At the end of the study, the pre-service teachers were found to have some misconceptions; for example, they think that semi-conductors conduct the half of the electricity conducted by conductors. In the study, it was found that the pre-service teachers cannot define the concept of semi-conductor and this might indicate that they will not be able to teach this concept when they become teachers. In this connection, it can be suggested that studies and activities performed for teaching of abstract concepts such as conductor, semi-conductor, and insulator should be increased.

  17. On the role of precursor powder composition in controlling microstructure, flux pinning, and the critical current density of Ag/Bi2Sr2CaCu2Ox conductors

    Science.gov (United States)

    Li, Pei; Naderi, Golsa; Schwartz, Justin; Shen, Tengming

    2017-03-01

    Precursor powder composition is known to strongly affect the critical current density (J c) of Ag/Bi2Sr2CaCu2Ox (Bi-2212) wires. However, reasons for such J c dependence have not yet been fully understood, compromising our ability to achieve further optimization. We systematically examined superconducting properties, microstructural evolution and phase transformation, and grain boundaries of Bi-2212 conductors fabricated from precursor powders with a range of compositions using a combination of transport-current measurements, a quench technique to freeze microstructures at high temperatures during heat treatment, and scanning transmission electron microscopy (STEM). Samples include both dip-coated tapes and round wires, among which a commercial round wire carries a high J c of 7600 A mm-2 at 4.2 K, self-field and 2600 A mm-2 at 4.2 K, 20 T, respectively. In the melt, this high-J c conductor, made using a composition of Bi2.17Sr1.94Ca0.89Cu2Ox, contains a uniform dispersion of fine alkaline-earth cuprate (AEC) and copper-free solid phases, whereas several low-J c conductors contain large AEC particles. Such significant differences in the phase morphologies in the melt are accompanied by a drastic difference in the formation kinetics of Bi-2212 during recrystallization cooling. STEM studies show that Bi-2212 grain colonies in the high-J c conductors have a high density of Bi2Sr2CuO y (Bi-2201) intergrowths, whereas a low-J c conductor, made using Bi2.14Sr1.66Ca1.24Cu1.96O x , is nearly free of them. STEM investigation shows grain boundaries in low-J c conductors are often insulated with a Bi-rich amorphous phase. High-J c conductors also show higher flux-pinning strength, which we ascribe to their higher Bi-2201 intergrowth density.

  18. Analysis Methods of HTLS Conductors in Terms of Mechanical and Thermal Criteria

    Directory of Open Access Journals (Sweden)

    Paweł Kubek

    2013-03-01

    Full Text Available A thermal modernization allows increasing the thermal rating of the existing lines. This especially concerns the older overhead lines designed for the +40°C temperature conductor limit. This paper presents reconductoring as the attractive method of existing line thermal modernization. The article provides an overview of issues related to the selection of the HTLS conductor for thermal uprating of existing overhead transmission lines. Some aspects related to the extension of the thermal, electrical and mechanical models used so far for analysis of HTLS conductors are presented in the paper.

  19. Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor

    Science.gov (United States)

    Powell, Michael R; Whyatt, Greg A; Howe, Daniel T; Fountain, Matthew S

    2014-03-04

    The efficiency and effectiveness of apparatuses for vaporizing and combusting liquid fuel can be improved using thermal conductors. For example, an apparatus having a liquid fuel vaporizer and a combustion chamber can be characterized by a thermal conductor that conducts heat from the combustion chamber to the vaporizer. The thermal conductor can be a movable member positioned at an insertion depth within the combustion chamber that corresponds to a rate of heat conduction from the combustion chamber to the vaporizer. The rate of heat conduction can, therefore, be adjusted by positioning the movable member at a different insertion depth.

  20. AFM multilayered Bi-2223 conductors for 13,000 A current leads for CERN

    CERN Document Server

    Martini, L; Berti, R; Volpini, G; Bigoni, L; Curcio, F

    2000-01-01

    Large current carrying capacity multilayered Bi-2223 conductors are reproducibly prepared by means of the "Accordion-Folding Method" and suitably used to manufacture the low temperature stage of 13,000 A hybrid metal-HTS current lead prototypes for CERN. In this work, we report on the electrical characterisation of AFM multilayered Bi-2223 conductors having critical current as high as 400 A at 77 K and on a specific experimental set-up that has been developed to study the thermo-electrical performances of the AFM Bi-2223 composite conductors during the sudden resistive transition of the HTS: quench event. (4 refs).

  1. Electrocurtain coating process for coating solar mirrors

    Science.gov (United States)

    Kabagambe, Benjamin; Boyd, Donald W.; Buchanan, Michael J.; Kelly, Patrick; Kutilek, Luke A.; McCamy, James W.; McPheron, Douglas A.; Orosz, Gary R.; Limbacher, Raymond D.

    2013-10-15

    An electrically conductive protective coating or film is provided over the surface of a reflective coating of a solar mirror by flowing or directing a cation containing liquid and an anion containing liquid onto the conductive surface. The cation and the anion containing liquids are spaced from, and preferably out of contact with one another on the surface of the reflective coating as an electric current is moved through the anion containing liquid, the conductive surface between the liquids and the cation containing liquid to coat the conductive surface with the electrically conductive coating.

  2. Insulation-resistance measurements of coated and uncoated printed wiring boards

    Science.gov (United States)

    Jennings, C. W.

    1983-06-01

    Insulation resistance (IR) was measured between narrow spaced conductors on different types of printed circuit boards with and without polymer coatings. Measurement environments consisted of thermal cycling in a humid environment per MIL-STD-202/106, and room temperature with 5 to 100 percent relative humidity (R.H.). The variability of the IR of test patterns both within a board and between boards with the same coating, and the lack of consistent resistivity values, suggest that the measured IR in these environments is not inherent to the materials, but is related to the contaminates present on and in the materials. There was little difference in IR for different conformal coatings or laminate types or sources. Although the IR was found to increase significantly when a board was conformally coated, there was no coating type tested which could ensure a high IR. Porcelain enamel and multiwire boards had lowers IR than conventional circuit boards. An association was observed between low IR and the tendency for dendritic filament formation between conductors in a 100 percent R.H. environment.

  3. Bos taurus genome assembly.

    Science.gov (United States)

    Liu, Yue; Qin, Xiang; Song, Xing-Zhi Henry; Jiang, Huaiyang; Shen, Yufeng; Durbin, K James; Lien, Sigbjørn; Kent, Matthew Peter; Sodeland, Marte; Ren, Yanru; Zhang, Lan; Sodergren, Erica; Havlak, Paul; Worley, Kim C; Weinstock, George M; Gibbs, Richard A

    2009-04-24

    We present here the assembly of the bovine genome. The assembly method combines the BAC plus WGS local assembly used for the rat and sea urchin with the whole genome shotgun (WGS) only assembly used for many other animal genomes including the rhesus macaque. The assembly process consisted of multiple phases: First, BACs were assembled with BAC generated sequence, then subsequently in combination with the individual overlapping WGS reads. Different assembly parameters were tested to separately optimize the performance for each BAC assembly of the BAC and WGS reads. In parallel, a second assembly was produced using only the WGS sequences and a global whole genome assembly method. The two assemblies were combined to create a more complete genome representation that retained the high quality BAC-based local assembly information, but with gaps between BACs filled in with the WGS-only assembly. Finally, the entire assembly was placed on chromosomes using the available map information.Over 90% of the assembly is now placed on chromosomes. The estimated genome size is 2.87 Gb which represents a high degree of completeness, with 95% of the available EST sequences found in assembled contigs. The quality of the assembly was evaluated by comparison to 73 finished BACs, where the draft assembly covers between 92.5 and 100% (average 98.5%) of the finished BACs. The assembly contigs and scaffolds align linearly to the finished BACs, suggesting that misassemblies are rare. Genotyping and genetic mapping of 17,482 SNPs revealed that more than 99.2% were correctly positioned within the Btau_4.0 assembly, confirming the accuracy of the assembly. The biological analysis of this bovine genome assembly is being published, and the sequence data is available to support future bovine research.

  4. Bos taurus genome assembly

    Directory of Open Access Journals (Sweden)

    Sodergren Erica

    2009-04-01

    Full Text Available Abstract Background We present here the assembly of the bovine genome. The assembly method combines the BAC plus WGS local assembly used for the rat and sea urchin with the whole genome shotgun (WGS only assembly used for many other animal genomes including the rhesus macaque. Results The assembly process consisted of multiple phases: First, BACs were assembled with BAC generated sequence, then subsequently in combination with the individual overlapping WGS reads. Different assembly parameters were tested to separately optimize the performance for each BAC assembly of the BAC and WGS reads. In parallel, a second assembly was produced using only the WGS sequences and a global whole genome assembly method. The two assemblies were combined to create a more complete genome representation that retained the high quality BAC-based local assembly information, but with gaps between BACs filled in with the WGS-only assembly. Finally, the entire assembly was placed on chromosomes using the available map information. Over 90% of the assembly is now placed on chromosomes. The estimated genome size is 2.87 Gb which represents a high degree of completeness, with 95% of the available EST sequences found in assembled contigs. The quality of the assembly was evaluated by comparison to 73 finished BACs, where the draft assembly covers between 92.5 and 100% (average 98.5% of the finished BACs. The assembly contigs and scaffolds align linearly to the finished BACs, suggesting that misassemblies are rare. Genotyping and genetic mapping of 17,482 SNPs revealed that more than 99.2% were correctly positioned within the Btau_4.0 assembly, confirming the accuracy of the assembly. Conclusion The biological analysis of this bovine genome assembly is being published, and the sequence data is available to support future bovine research.

  5. Analysis of Hard Thin Film Coating

    Science.gov (United States)

    Shen, Dashen

    1998-01-01

    MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

  6. Transient Thermal Analysis of Intense Proton Beam Loss on a Kicker Magnet Conductor Plate

    CERN Document Server

    Knaus, P

    2000-01-01

    The Super Proton Synchrotron SPS will be used as injector for the Large Hadron Collider LHC and needs adaptation to meet LHC requirements. The SPS injection kicker magnets MKP will undergo important modifications to comply with the requirements on magnetic field rise-time and ripple. The injection kicker presently installed has a return conductor of beryllium to minimise the risk of metal evaporation from its surface due to heating caused by beam impact. In the context of refurbishing the MKP to satisfy LHC requirements these conductors need replacement, preferably with a less delicate material. This article presents the transient thermal analysis of energy deposition caused by beam loss on the conductor plate. The expected time structure of the beam is taken into account. Simulations comparing different conductor materials have been performed, leading to the result that a significantly cheaper and fully inoffensive titanium alloy can satisfy the needs.

  7. Stability of cable-in-conduit, force-cooled conductors: elementary theory

    Energy Technology Data Exchange (ETDEWEB)

    Dresner, L.

    1979-01-01

    The recovery of cable-in-conduit conductors cooled by supercritical helium has been studied. The initial perturbation is a sudden, uniform deposition of heat. The problem has been solved, and answers have been obtained in the form of simple closed formulas under the simplifying assumption of constant thermophysical properties. Stability-optimized conductors have been identified and simple formulas for their material composition are given. A rule of design of cable-in-conduit conductors based on the existence of stability-optimized conductors is suggested. Some ''zero-flow'' experiments of Miller et al. have been analyzed, and it has been determined that for these experiments the effective heat transfer coefficient during the period of recovery is approximately 1000 Wm/sup -2/K/sup -1/.

  8. Numerical modelling of impedance spectra of ionic conductor-insulator core-shell composites

    Science.gov (United States)

    Laugier, J.-M.; Raymond, L.; Albinet, G.; Knauth, P.

    2011-09-01

    Impedance spectra of ionic conductor-insulator core-shell composites are simulated in Cole-Cole and Bode representation using a 3D lattice of parallel resistance-capacitance elements. The composite model is based on a random ternary network, considering three impedance elements: good conductor (representing interface regions), conductor and insulator. The favourable interactions between the two phases lead to a significant non-random situation versus usual percolation models. Two percolation transitions are well observed: the first corresponds to ionic conduction enhancement by space charge layers. After the second transition, the conduction pathways are blocked by the insulator and the conductivity drops dramatically. Experimental impedance spectra of model copper- and lithium-ion conducting composites and nanocomposites are in good agreement with the simulation. The dc conductivity maximum can be described by a master equation: σmax ~ N-0.79 where N is proportional to the ionic conductor grain size.

  9. Stress-tuned conductor-polymer composite for use in sensors

    Science.gov (United States)

    Martin, James E; Read, Douglas H

    2013-10-22

    A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.

  10. Materials, Mechanics, and Patterning Techniques for Elastomer-Based Stretchable Conductors

    Directory of Open Access Journals (Sweden)

    Xiaowei Yu

    2016-12-01

    Full Text Available Stretchable electronics represent a new generation of electronics that utilize soft, deformable elastomers as the substrate or matrix instead of the traditional rigid printed circuit boards. As the most essential component of stretchable electronics, the conductors should meet the requirements for both high conductivity and the capability to maintain conductive under large deformations such as bending, twisting, stretching, and compressing. This review summarizes recent progresses in various aspects of this fascinating and challenging area, including materials for supporting elastomers and electrical conductors, unique designs and stretching mechanics, and the subtractive and additive patterning techniques. The applications are discussed along with functional devices based on these conductors. Finally, the review is concluded with the current limitations, challenges, and future directions of stretchable conductors.

  11. MHD instabilities developing in a conductor exploding in the skin effect mode

    Science.gov (United States)

    Oreshkin, V. I.; Chaikovsky, S. A.; Datsko, I. M.; Labetskaya, N. A.; Mesyats, G. A.; Oreshkin, E. V.; Ratakhin, N. A.; Rybka, D. V.

    2016-12-01

    The results of experiments with exploding copper conductors, performed on the MIG facility (providing currents of amplitude of about 2.5 MA and rise time of 100 ns), are analyzed. With an frame optical camera, large-scale instabilities of wavelength 0.2-0.5 mm were detected on the conductor surface. The instabilities show up as plasma "tongues" expanding with a sound velocity in the opposite direction to the magnetic field gradient. Analysis performed using a two-dimensional MHD code has shown that the structures observed in the experiments were formed most probably due to flute instabilities. The growth of flute instabilities is predetermined by the development of thermal instabilities near the conductor surface. The thermal instabilities arise behind the front of the nonlinear magnetic diffusion wave propagating through the conductor. The wavefront on its own is not subject to thermal instabilities.

  12. Enhanced Mixed Electronic-Ionic Conductors through Cation Ordering

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Allan J. [Univ. of Houston, TX (United States); Morgan, Dane [Univ. of Wisconsin, Madison, WI (United States); Grey, Clare [Stony Brook Univ., NY (United States)

    2014-08-31

    The performance of many energy conversion and storage devices depend on the properties of mixed ionic-electronic conducting (miec) materials. Mixed or ambipolar conductors simultaneously transport ions and electrons and provide the critical interface between chemical and electrical energy in devices such as fuel cells, ion transport membranes, and batteries. Enhancements in storage capacity, reversibility, power density and device lifetime all require new materials and a better understanding of the fundamentals of ambipolar conductivity and surface reactivity.The high temperature properties of the ordered perovksites AA’B2O5+x, where A = rare earth ion, Y and B = Ba, Sr were studied. The work was motivated by the high oxygen transport and surface exchange rates observed for members of this class of mixed ionic and electronic conductors. A combined experimental and computational approach, including structural, electrochemical, and transport characterization and modeling was used. The approach attacks the problem simultaneously at global (e.g., neutron diffraction and impedance spectroscopy), local (e.g., pair distribution function, nuclear magnetic resonance) and molecular (ab initio thermokinetic modeling) length scales. The objectives of the work were to understand how the cation and associated anion order lead to exceptional ionic and electronic transport properties and surface reactivity in AA’B2O5+x perovskites. A variety of compounds were studied by X-ray and neutron diffraction, measurements of thermodynamics and transport and theoretically. These included PrBaCo2O5+x and NdBaCo2O5+x, PrBaCo2-xFexO6- δ (x = 0, 0.5, 1.0, 1.5 and 2) and LnBaCoFeO6- δ (Ln = La, Pr, Nd, Sm, Eu and Gd), Sr3YCo4O10.5, YBaMn2O5+x. A0.5A’0.5BO3 (where A=Y, Sc, La, Ce, Pr, Nd, Pm, Sm; A’= Sr

  13. Qualification of the US made conductors for ITER TF magnet system

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, N; Hatfield, D; Miller, J; Bruzzone, P; Stepanov, B; Seber, B

    2009-10-08

    The US Domestic Agency (USDA) is one of the six suppliers of the TF conductor for ITER. In order to qualify conductors according to ITER requirements we prepared several lengths of the CICC and short samples for testing in the SULTAN facility in CRPP, Switzerland. We also fully characterized the strands that were used in these SULTAN samples. Fabrication experience and test results are presented and discussed.

  14. Powder-in-tube (PIT) $Nb_{3}Sn$ conductors for high-field magnets

    CERN Document Server

    Lindenhovius, J L H; den Ouden, A; Wessel, W A J; ten Kate, H H J

    2000-01-01

    New Nb/sub 3/Sn conductors, based on the powder-in-tube (PIT) process, have been developed for application in accelerator magnets and high-field solenoids. For application in accelerator magnets, SMI has developed a binary 504 filament PIT conductor by optimizing the manufacturing process and adjustment of the conductor lay-out. It uniquely combines a non-copper current density of 2680 A/mm/sup 2/@10 T with an effective filament diameter of about 20 mu m. This binary conductor may be used in a 10 T, wide bore model separator dipole magnet for the LHC, which is being developed by a collaboration of the University of Twente and CERN. A ternary (Nb/7.5wt%Ta)/sub 3/Sn conductor containing 37 filaments is particularly suited for application in extremely high-field superconducting solenoids. This wire features a copper content of 43%, a non-copper current density of 217 A/mm/sup 2/@20 T and a B/sub c2/ of 25.6 T. The main issues and the experimental results of the development program of PIT Nb/sub 3/Sn conductors a...

  15. Conformal coating value/risk assessment for Sandia satellite programs.

    Energy Technology Data Exchange (ETDEWEB)

    Russick, Edward Mark; Thayer, Gayle Echo

    2008-03-01

    Conformal coatings are used in space applications on printed circuit board (PCB) assemblies primarily as a protective barrier against environmental contaminants. Such coatings have been used at Sandia for decades in satellite applications including the GPS satellite program. Recently, the value of conformal coating has been questioned because it is time consuming (requiring a 5-6 week schedule allowance) and delays due to difficulty of repairs and rework performed afterward are troublesome. In an effort to find opportunities where assembly time can be reduced, a review of the literature as well as discussions with satellite engineers both within and external to Sandia regarding the value of conformal coating was performed. Several sources on the value of conformal coating, the functions it performs, and on whether coatings are necessary and should be used at all were found, though nearly all were based on anecdotal information. The first section of this report, titled 'Conformal Coating for Space Applications', summarizes the results of an initial risk-value assessment of the conformal coating process for Sandia satellite programs based on information gathered. In the process of collecting information to perform the assessment, it was necessary to obtain a comprehensive understanding of the entire satellite box assembly process. A production time-line was constructed and is presented in the second section of this report, titled 'Satellite Box Assembly', specifically to identify potential sources of time delays, manufacturing issues, and component failures related to the conformal coating process in relation to the box assembly. The time-line also allows for identification of production issues that were anecdotally attributed to the conformal coating but actually were associated with other production steps in the box assembly process. It was constructed largely in consultation with GPS program engineers with empirical knowledge of times required

  16. Large space-charge effects in a nanostructured proton conductor

    Energy Technology Data Exchange (ETDEWEB)

    Haverkate, Lucas A.; Chan, Wing K.; Mulder, Fokko M. [Fundamental Aspects of Materials and Energy, Department of Radiation, Radionuclides, and Reactors, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands)

    2010-12-08

    Decreasing the dimensions of heterogeneous mixtures of ionic conductors towards the nanoscale results in ionic conduction enhancements, caused by the increased influence of the interfacial space-charge regions. For a composite of TiO{sub 2} anatase and solid acid CsHSO{sub 4}, the strong enhancement of the ionic conductivity at the nanoscale also can be assigned to this space-charge effect. Surprisingly high hydrogen concentrations in the order of 10{sup 21} cm{sup -3} in TiO{sub 2} are measured, which means that about 10% of the available sites for H{sup +} ions are filled on average. Such high concentrations require a specific elaboration of the space-charge model that is explicitly performed here, by taking account of the large occupation numbers on the exhaustible sites. It is shown that ionic defects with negative formation enthalpy reach extremely high concentrations near the interfaces and throughout the material. By performing first-principles density functional theory calculations, it is found that proton insertion from CsHSO{sub 4} into the TiO{sub 2} particles is preferred compared to neutral hydrogen atom insertion and indeed that the formation enthalpy is negative. Moreover, the average proton fractions in TiO{sub 2}, estimated by the theoretical ionic density profiles, are in good agreement with the experimental observations. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Eddy damping effect of additional conductors in superconducting levitation systems

    Science.gov (United States)

    Jiang, Zhao-Fei; Gou, Xiao-Fan

    2015-12-01

    Passive superconducting levitation systems consisting of a high temperature superconductor (HTSC) and a permanent magnet (PM) have demonstrated several fascinating applications such as the maglev system, flywheel energy storage. Generally, for the HTSC-PM levitation system, the HTSC with higher critical current density Jc can obtain larger magnetic force to make the PM levitate over the HTSC (or suspended below the HTSC), however, the process of the vibration of the levitated PM, provides very limited inherent damping (essentially hysteresis). To improve the dynamic stability of the levitated PM, eddy damping of additional conductors can be considered as the most simple and effective approach. In this article, for the HTSC-PM levitation system with an additional copper damper attached to the HTSC, we numerically and comprehensively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. Furthermore, we comparatively studied four different arrangements of the copper damper, on the comprehensive analyzed the damping effect, efficiency (defined by c/VCu, in which VCu is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.

  18. Conduction Mechanisms and Structure of Ionomeric Single-Ion Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Colby, Ralph H. [Pennsylvania State Univ., University Park, PA (United States); Maranas, Janna K. [Pennsylvania State Univ., University Park, PA (United States); Mueller, Karl T. [Pennsylvania State Univ., University Park, PA (United States); Runt, James [Pennsylvania State Univ., University Park, PA (United States); Winey, Karen I. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    2015-03-01

    Our team has designed using DFT (Gaussian) and synthesized low glass transition temperature single-ion conductors that are either polyanions that conduct small cations Li+, Na+, Cs+ or polycations that conduct small anions F-, OH-, Br-. We utilize a wide range of complimentary experimental materials characterization tools to understand ion transport; differential scanning calorimetry, dielectric relaxation spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, linear viscoelasticity, X-ray scattering and molecular dynamics simulations. The glass transition temperature Tg needs to be as low as possible to facilitate ion transport, so the nonionic parts of the polymer need to be polar, flexible and have strong solvation interactions with the ions. The lowest Tg we have managed for polyanions conducting Li+ is -60 °C. In contrast, polysiloxanes with PEO side chains and tetrabutylphosphonium cationic side groups have Tg ≈ -75 °C that barely increases with ion content, as anticipated by DFT. A survey of all polyanions in the literature suggests that Tg < -80 °C is needed to achieve the 10-4 S/cm conductivity needed for battery separators.

  19. Magneto-optical studies of low-dimensional organic conductors

    Directory of Open Access Journals (Sweden)

    Hitoshi Ohta, Motoi Kimata and Yugo Oshima

    2009-01-01

    Full Text Available Our periodic orbit resonance (POR results on quasi-two-dimensional (q2D, highly anisotropic q2D and quasi-one-dimensional (q1D organic conductors are reviewed together with our rotational cavity magneto-optical measurement system. Higher order POR up to seventh order has been observed in the q2D system (BEDT-TTF2Br(DIA, and the experimental conditions to observe POR and the cyclotron resonance (CR are discussed. Highly anisotropic q2D Fermi surface (FS in β''-(BEDT-TTF(TCNQ, which was considered to have q1D FS previously, is proposed by our POR measurements, and the possible interpretations of other experimental results of β''-(BEDT-TTF(TCNQ are discussed assuming the highly anisotropic q2D FS. Finally, detailed q1D FS of (DMET2I3, obtained from our POR results, is discussed in connection with the typical q1D system (TMTSF2ClO4.

  20. Optimization study of normal conductor tokamak for commercial neutron source

    Science.gov (United States)

    Fujita, T.; Sakai, R.; Okamoto, A.

    2017-05-01

    The optimum conceptual design of tokamak with normal conductor coils was studied for minimizing the cost for producing a given neutron flux by using a system code, PEC. It is assumed that the fusion neutrons are used for burning transuranics from the fission reactor spent fuel in the blanket and a fraction of the generated electric power is circulated to opearate the tokamak with moderate plasma fusion gain. The plasma performance was assumed to be moderate ones; {β\\text{N}}~∼ ~3{--}4 in the aspect ratio A~=~2{--}3 and {{H}98y2}~=~1 . The circulating power is an important factor affecting the cost. Though decreasing the aspect ratio is useful to raise the plasma beta and decrease the toroidal field, the maximum field in the coil starts to rise in the very low aspect ratio range and then the circulating power increases with decrease in the plasma aspect ratio A below A~∼ ~2 , while the construction cost increases with A . As a result, the cost per neutron has its minimum around A~∼ ~2.2 , namely, between ST and the conventional tokamak. The average circulating power fraction is expected to be ~51%.