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Sample records for 2g ybco coated

  1. Doubling of the Critical Current Density of 2G-YBCO Coated Conductors through proton irradiation

    NASA Astrophysics Data System (ADS)

    Welp, Ulrich; Jia, Ying; Kwok, Wai-Kwong; Rupich, Marty; Fleshler, Steven; Kayani, Asfghar

    2013-03-01

    We report on magnetization and transport measurements of the critical current density of commercial 2G YBCO coated conductors before and after proton irradiation. The samples were irradiated along the c-axis with 4 MeV protons to a fluence of 1.5x1016 p/cm2. We find that at temperatures below 50 K, proton irradiation increases Jc by a factor of 2 in low fields and increases up to 2.5 in fields of 7 T. At 77 K, proton irradiation is less effective in enhancing the critical current. Doubling of Jc in fields of several Tesla and at temperatures below 50 K will be highly beneficial for applications of coated conductors in rotating machinery, generators and magnet coils. - Work supported by the US DoE-BES funded Energy Frontier Research Center (YJ), and by Department of Energy, Office of Science, Office of Basic Energy Sciences (UW, WKK), under Contract No. DE-AC02-06CH11357.

  2. AC Loss Measurements on a 2G YBCO Coil

    SciTech Connect

    Rey, Christopher M; Duckworth, Robert C; Schwenterly, S W

    2011-01-01

    The Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES) to continue development of HTS power transformers. For compatibility with the existing power grid, a commercially viable HTS transformer will have to operate at high voltages in the range of 138 kV and above, and will have to withstand 550-kV impulse voltages as well. Second-generation (2G) YBCO coated conductors will be required for an economically-competitive design. In order to adequately size the refrigeration system for these transformers, the ac loss of these HTS coils must be characterized. Electrical AC loss measurements were conducted on a prototype high voltage (HV) coil with co-wound stainless steel at 60 Hz in a liquid nitrogen bath using a lock-in amplifier technique. The prototype HV coil consisted of 26 continuous (without splice) single pancake coils concentrically centered on a stainless steel former. For ac loss measurement purposes, voltage tap pairs were soldered across each set of two single pancake coils so that a total of 13 separate voltage measurements could be made across the entire length of the coil. AC loss measurements were taken as a function of ac excitation current. Results show that the loss is primarily concentrated at the ends of the coil where the operating fraction of critical current is the highest and show a distinct difference in current scaling of the losses between low current and high current regimes.

  3. Fabrication of Filamentary YBCO Coated Conductor by Inkjet Printing

    SciTech Connect

    List III, Frederick Alyious; Kodenkandath, Thomas; Rupich, Marty

    2007-01-01

    Inkjet printing is a potentially low cost, high rate method for depositing precursors for filamentary YBCO coated conductors. The method offers considerable flexibility of filament pattern, width, and thickness. Using standard solution precursors and RABiTSTM substrates, the printing, processing, and properties of some inkjet-derived filamentary YBCO coated conductors for Second Generation (2G) wire are demonstrated on a laboratory scale. Some systematic variations of growth rate and critical transport current with filament width are observed and discussed.

  4. Maximum permissible voltage of YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.

    2014-06-01

    Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  5. Remarkable weakness against cleavage stress for YBCO-coated conductors and its effect on the YBCO coil performance

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Y.; Nakagome, H.; Takematsu, T.; Takao, T.; Sato, N.; Takahashi, M.; Maeda, H.

    2011-08-01

    Cleavage strength for an YBCO-coated conductor at 77 K was investigated with a model experiment. The nominal cleavage strength for an YBCO-coated conductor is extremely low, typically 0.5 MPa. This low nominal cleavage strength is due to stress concentration on a small part of the YBCO-coated conductor in cleavage fracture. Debonding by the cleavage stress occurs at the interface between the buffer layer and the Hastelloy substrate. The nominal cleavage strength for a slit edge of the conductor is 2.5-times lower than that for the original edge of the conductor; cracks and micro-peel existing over the slit edge reduce the cleavage strength for the slit edge. Cleavage stress and peel stress should be avoided in coil winding, as they easily delaminate the YBCO-coated conductor, resulting in substantial degradation of coil performance. These problems are especially important for epoxy impregnated YBCO-coated conductor coils. It appears that effect of cleavage stress and peel stress are mostly negligible for paraffin impregnated YBCO-coated conductor coils or dry wound YBCO-coated conductor coils.

  6. Solderability Study of RABiTS-Based YBCO Coated Conductors

    SciTech Connect

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

    2011-01-01

    The solderability of commercially available YBa{sub 2}Cu{sub 3}O{sub 7-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.

  7. All MOD buffer/YBCO approach to coated conductors

    NASA Astrophysics Data System (ADS)

    Parans Paranthaman, M.; Sathyamurthy, S.; Heatherly, L.; Martin, P. M.; Goyal, A.; Kodenkandath, T.; Li, X.; Thieme, C. L. H.; Rupich, M. W.

    2006-10-01

    RABiTS based metal-organic deposition (MOD) buffer/YBa2Cu3O7-δ (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-μm 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.

  8. All MOD Buffer/YBCO Approach to Coated Conductors

    SciTech Connect

    Paranthaman, Mariappan Parans; Sathyamurthy, Srivatsan; Heatherly Jr, Lee; Martin, Patrick M; Goyal, Amit; Kodenkandath, Thomas; Li, Xiaoping; Thieme, C. L. H.; Rupich, Marty

    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.

  9. Reel-to-reel fabrication of meter-long YBCO coated conductor

    NASA Astrophysics Data System (ADS)

    Yang, J.; Zhang, H.; Wang, S. M.; Lin, C. G.; Shi, D. Q.; Dou, S. X.

    2011-04-01

    YBa 2Cu 3O 7-δ (YBCO) superconductors were coated on the CeO 2/YSZ/Y 2O 3 buffered Ni-5at%W tapes by a reel-to-reel pulsed laser deposition (PLD). The process of a multi-layer deposition of YBCO film was explored. X-ray diffraction texture measurements showed good both in-plane and out of plane crystalline orientations in YBCO films. The average values calculated at a full width at half maximum (FWHM) of the peaks from phi-scans ( φ) and omega ( ω) scans for one meter-long YBCO tape were 7.49° and 4.71°, respectively. The critical current ( Ic) was over 200 A/cm-width at 77 K and under self-field for meter-long YBCO tape. The critical transition temperature of the YBCO tape was typically as 90.1 K with 0.5 K transition widths.

  10. YBCO coated conductors on highly textured Pd-buffered Ni-W tape

    NASA Astrophysics Data System (ADS)

    Celentano, G.; Galluzzi, V.; Mancini, A.; Rufoloni, A.; Vannozzi, A.; Augieri, A.; Petrisor, T.; Ciontea, L.; Gambardella, U.

    2006-06-01

    High critical current density YBa2Cu3O7-x (YBCO) coated conductors were obtained on cube textured Ni-W. The use of a Pd transient layer as a first buffer led to a sharp out-of-plane grains alignment of the CeO2/YSZ/CeO2 buffer layer. YBCO films grown on this template exhibit an out-of-plane orientation with a full width at half maximum of about 3°, less than 50% of the respective starting Ni-W value. Despite the complete interdiffusion between Ni-W and Pd after the YBCO film deposition, the coated conductors exhibit good film adherence as well as a crack free and smooth surface of the YBCO film. YBCO thin films show critical temperature values above than 88 K and a critical current density of 2.1 MA/cm2 at 77 K and self field.

  11. Preparation and characterization of YBCO coating on metallic RABiT substrates by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Gonal, M. R.; Prajapat, C. L.; Igalwar, P. S.; Maji, B. C.; Singh, M. R.; Krishnan, M.

    2016-05-01

    Superconducting YBCO films are coated on metallic Rolling Assisted Bi-axially Textured Substrates (RABiTS) Ni-5wt % W (NiW) (002) substrate using pulsed laser deposition (PLD) system. Targets of YBa2Cu3O7-δ (YBCO) and buffer layers of Ceria and 8 mole % Yttria Stabilized Zirconia (YSZ) of high density are synthesized. At each stage of deposition coatings are characterized by XRD. Transport studies show superconducting nature of YBCO only when two successive buffer layers of YSZ and CeO2 are used.

  12. Nonvacuum Deposition of Silver Doped YBCO Coated Conductor on %100 Lattice Match Buffered Ni Tapes

    NASA Astrophysics Data System (ADS)

    Arda, L.; Cakiroglu, O.; Keskin, S.; Sacli, O. A.

    2007-04-01

    Silver doped YBa2Cu3O7-δ (YBCO) coated conductors were fabricated on Gd1.624Ho0.376O3 (100 % lattice match with YBCO) textured buffer layers on Ni tape by reel-to-reel sol-gel dip coating system. Sample were prepared with different wt(1-5) % Ag doped ratio. The surface morphologies and microstructure of all sample were characterized by ESEM, EDS and XRD. Pole figure texture analyses have been done to characterize texture of buffer layer and YBCO superconducting film . The critical current Ic measurement was performed using four wire method with the 1 μV/cm criterion. The critical current density, Jc was measured to be 2.2 × 104 A/cm2 at 77 K self field for 1 wt % Ag doped YBCO sample.

  13. Enhanced critical currents of commercial 2G superconducting coated conductors through proton irradiation

    NASA Astrophysics Data System (ADS)

    Welp, Ulrich; Leroux, M.; Kihlstrom, K. J.; Kwok, W.-K.; Koshelev, A. E.; Miller, D. J.; Rupich, M. W.; Fleshler, S.; Malozemoff, A. P.; Kayani, A.

    2015-03-01

    We report on magnetization and transport measurements of the critical current density, Jc, of commercial 2G YBCO coated conductors before and after proton irradiation. The samples were irradiated along the c-axis with 4 MeV protons. Proton irradiation produces a mixed pinning landscape composed of pre-existing rare earth particles and a uniform distribution of irradiation induced nm-sized defects. This pinning landscape strongly reduces the suppression of Jc in magnetic fields resulting in a doubling of Jc in a field of ~ 4T. The irradiation dose-dependence of Jc is characterized by a temperature and field dependent sweat spot that at 5 K and 6 T occurs around 20x1016 p/cm2. Large-scale time dependent Ginzburg-Landau simulations yield a good description of our results. This work supported by the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the U.S. D.O.E., Office of Science, Office of Basic Energy Sciences (KK, ML, AEK) and by the D.O.E, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 (UW, WKK).

  14. On-line characterization of YBCO coated conductors using Raman spectroscopy methods.

    SciTech Connect

    Maroni, V. A.; Reeves, J. L.; Schwab, G.; Chemical Engineering; SuperPower, Inc.

    2007-04-01

    The use of Raman spectroscopy for on-line monitoring of the production of superconducting YBa2Cu3O6+X (YBCO) thin films on long-length metal tapes coated with textured buffer layers is reported for the first time. A methodology is described for obtaining Raman spectra of YBCO on moving tape exiting a metal-organic-chemical-vapor-deposition (MOCVD) enclosure. After baseline correction, the spectra recorded in this way show the expected phonons of the specific YBCO crystal orientation required for high supercurrent transport, as well as phonons of non-superconducting second-phase impurities when present. It is also possible to distinguish YBCO films that are properly textured from films having domains of misoriented YBCO grains. An investigation of the need for focus control on moving tape indicated that focusing of the laser on the surface of the highly reflective YBCO films exiting the MOCVD enclosure tends to produce aberrant photon bursts that swamp the Raman spectrum. These photon bursts are very likely a consequence of optical speckle effects induced by a combination of surface roughness, crystallographic texture, and/or local strain within the small grain microstructure of the YBCO film. Maintaining a slightly out-of-focus condition provides the best signal-to-noise ratio in terms of the obtained Raman spectra. In addition to examining moving tape at the post-MOCVD stage, Raman spectra of the film surface can also be recorded after the oxygen anneal performed to bring the YBCO to the optimum superconducting state. Consideration is given to data processing methods that could be adapted to the on-line Raman spectra to allow the tagging of out-of-specification tape segments and, at a more advanced level, feedback control to the MOCVD process.

  15. Nickel-copper alloy tapes as textured substrates for YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Vannozzi, A.; Celentano, G.; Angrisani, A.; Augieri, A.; Ciontea, L.; Colantoni, I.; Galluzzi, V.; Gambardella, U.; Mancini, A.; Petrisor, T.; Rufoloni, A.; Thalmaier, G.

    2008-02-01

    NiCuCo alloy tape was studied as textured substrates for YBCO coated conductors application. The addition of a small amount of cobalt was pursued in order to enhance the microstructure of the NiCu alloy. The use of different thermal treatments during the recrystallization process permitted to obtain area densities of cube orientation as high as 95%. The substrate was thoroughly characterized by means of x-ray diffraction, EBSD and SEM analyses. Further, the mechanical properties and the magnetic behaviour of this substrate have been investigated and compared with those exhibited by Ni, NiW and NiCu tapes. The suitability of this alloy substrate for YBCO coated conductors has been tested through the deposition of a conventional CeO2/YSZ/CeO2 buffer layer architecture using a Pd transient layer. Apart from passivating Ni-Cu-Co substrate, the use of a Pd transient layer produces a relevant texture sharpening in the out-of-plane orientation and the full width at half maximum of the ?-scan drops from about 9° of NiCuCo to 2° of Pd layer. This sharp texture is transferred to the YBCO film and the results indicate that NiCuCo alloy is a promising alternative substrate for the realization of YBCO coated conductors.

  16. Pd layer on cube-textured substrates for MOD-TFA and PLD YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Mancini, A.; Celentano, G.; Galluzzi, V.; Rufoloni, A.; Vannozzi, A.; Augieri, A.; Ciontea, L.; Petrisor, T.; Gambardella, U.; Longo, G.; Cricenti, A.

    2008-01-01

    Pd films were deposited on rolling assisted biaxially textured substrate (RABiTS) Ni-5 at.% W in order to exploit the Pd effect of the texture sharpening with respect to that of the substrate, for the development of YBa2Cu3O7-x (YBCO) coated conductors. The Pd sharpening effect was relevant in the out-of-plane direction where the reduction for the ω-scans' full width at half maximum (FWHM) ranged from 55 to 65%, depending on the substrate roughness. The obtained minimum values of the FWHM in the transverse rolling direction of the (002) Pd ω-scan and in the (111) Pd phi-scan were of about 2.5° and 5°, respectively. The CeO2/YSZ/CeO2 (YSZ is Y2O3-stabilised ZrO2) heterostructure of the buffer layer was developed by pulsed laser deposition (PLD). In order to transfer the sharp orientation of the Pd film, both the seed CeO2 layer and the YSZ layer were deposited at low temperatures (450 °C), low enough to avoid Pd/Ni-W interdiffusion. The YBCO, films deposited by both PLD and metal-organic deposition (MOD) using metal trifluoroacetate acid (TFA), exhibited rolling direction (005) ω-scan and the (113) phi-scan FWHM values of about 2° and 5°, respectively. In spite of the complete interdiffusion between Ni and Pd during the YBCO film deposition, the coated conductors exhibit good adherence, as well as a smooth and crack-free surface. A zero-resistance critical temperature (TC0) of 90.8 K for the MOD-TFA YBCO films and critical current-density (JC) up to 2.2 MA cm-2 at 77 K and self-field for PLD YBCO films have been obtained.

  17. Long length oxide template for YBCO coated conductor prepared by surface-oxidation epitaxy method

    NASA Astrophysics Data System (ADS)

    Watanabe, Tomonori; Matsumoto, Kaname; Maeda, Toshihiko; Tanigawa, Toru; Hirabayashi, Izumi

    2001-08-01

    A 50 m long, biaxially textured NiO buffer layer for epitaxial growth ofYBa 2Cu 3O 7- δ (YBCO) film has been fabricated on the long cube textured nickel tape using surface-oxidation epitaxy (SOE) method. The SOE-NiO layers were highly {1 0 0} <0 0 1> textured. The full width at half maximum of 10-14.5° from X-ray φ-scan ( Δφ) was in the range of 10-14.5° through the whole length. The critical current density ( Jc) values exceeding 0.3 MA/cm 2 (77 K, 0 T) have been obtained in short samples of YBCO films on NiO/Ni tapes, by using thin MgO cap layer. Thirty meters long Ni-clad Ni-20wt.%Cr (Ni/NiCr) and Ni-clad austenitic stainless steel (Ni/SS) tapes were also prepared for YBCO coated conductors with higher strength and lower magnetism than those of pure nickel tape. Highly {1 0 0} <0 0 1> textured NiO layers were formed on those textured composite tapes by SOE method as same as on cube textured pure nickel tapes. YBCO films with Jc of 0.1 MA/cm 2 (77 K, 0 T) have been obtained on MgO/SOE-NiO layer of short Ni/NiCr composite tape.

  18. Thermal stability of YBCO coated conductor with different Cu stabilizer thickness

    NASA Astrophysics Data System (ADS)

    Bae, J. H.; Park, H. Y.; Eom, B. Y.; Seong, K. C.; Baik, S. K.

    2010-11-01

    The studies on the conduction-cooled superconducting magnets are actively underway with rapid advancement in refrigeration technology recently. YBCO coated conductor (CC) is one of the promising conductors for a conduction-cooled superconducting magnet because of increasing the operation temperature of magnets and being able to have cost collectiveness with conventional copper conductor in the future. However, it is known that quench propagation velocity in high-temperature superconductor (HTS) is two or three orders of magnitude slower than that in low-temperature superconductor because of its large heat capacity and the high operating temperature. The hot spot will emerge in local region if a critical current is non-uniform along the length of HTS tape and eventually, it causes permanent destroy for the whole HTS tape. Based on the protection of YBCO CC, it is necessary to determine a suitable stabilizer thickness for YBCO CC so that the temperature of hot spot in local area does not exceed the permissible temperature. In this study, we have established a suitable thermal analysis model, and analyzed minimum quench energy and thermal properties for three kinds of YBCO CC samples with different stabilizer thickness, which are fabricated by Superpower Incorporated, using finite element method.

  19. Fabrication and Characterization of YBCO Coated Conductors by Inclined Substrate Deposition

    NASA Astrophysics Data System (ADS)

    Ma, B.; Balachandran, U.; Xu, Y.; Bhattacharya, R.

    2006-03-01

    Inclined substrate deposition (ISD) is an effective method for rapid fabrication of high-quality template layers for YBCO-coated conductors. We have deposited biaxially textured ISD-MgO films on flexible metallic tapes in a reel-to-reel system by electron-beam evaporation at rapid deposition rates, 2-10 nmṡs-1. Strontium ruthenium oxide (SRO) buffer and YBCO films were grown by pulsed laser deposition (PLD). Pole figure analysis of a meter-long ISD-MgO tape was carried out by X-ray diffraction using a Bruker's D8 DISCOVER equipped with GADDS (general area detection diffraction system). The c-axis of the ISD-MgO film was tilted away from substrate normal. A full-width at half maximum (FWHM) of ≈10° was observed from the φ-scan of the MgO (002) diffraction measured on samples deposited with 35° inclination angle. Surface morphology measured by atomic force microscopy revealed a roof-tile shaped structure for the ISD-MgO films. Through the use of the SRO buffer, biaxial alignment in the YBCO film deposited on the ISD-MgO template was improved. The φ-scan FWHM was 5.8° for the YBCO (005) diffraction. We have measured the critical transition temperature Tc = 91 K and transport critical current density Jc >1.6×106 Aṡcm-2 at 77 K in self-field on a SRO-buffered YBCO film grown with ISD-MgO architecture.

  20. Inkjet printing of multifilamentary YBCO for low AC loss coated conductors

    NASA Astrophysics Data System (ADS)

    Hopkins, S. C.; Joseph, D.; Mitchell-Williams, T. B.; Calleja, A.; Vlad, V. R.; Vilardell, M.; Ricart, S.; Granados, X.; Puig, T.; Obradors, X.; Usoskin, A.; Falter, M.; Bäcker, M.; Glowacki, B. A.

    2014-05-01

    Considerable progress has been made with the development of REBCO coated conductors in recent years, and high performance conductors are available commercially. For many applications, however, the cost remains prohibitive, and AC losses discourage their selection for higher frequency applications. Chemical solution deposition (CSD) methods are attractive for low-cost, scalable preparation of buffer and superconductor layers, and in many respects inkjet printing is the method of choice, permitting non-contact deposition with minimal materials wastage and excellent control of coating thickness. Highly textured coatings of YBCO and Gd-doped CeO2 have previously been reported on buffered metal substrates. Inkjet printing also introduces the possibility of patterning - directly depositing two and three dimensional structures without subtractive processing - offering a low-cost route to coated conductors with reduced AC losses. In this contribution, the inkjet deposition of superconducting YBCO tracks is reported on industrially relevant buffered metal substrates both by direct printing and an inverse patterning approach. In the latter approach, ceria tracks were printed reported, which are a candidate both for resistive filament spacers and buffer layers. TFA-based precursor solutions have been printed on SS/ABAD-YSZ/CeO2 and Ni-W/LZO/CeO2 RABiTS substrates, and the resulting multifilamentary samples characterised by microscopy and scanning Hall probe measurements. The prospects for future inkjet-printed low AC loss coated conductors are discussed, including control of interfilamentary resistivity and bridging, transposed filamentary structures and stabilisation material.

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

    SciTech Connect

    Paranthaman, Mariappan Parans; Qiu, Xiaofeng; Kim, Kyunghoon; Shi, D.; Zhang, Yifei; Li, Xiaoping; Sathyamurthy, Srivatsan; Thieme, C. L. H.; Rupich, M. W.

    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.

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

    SciTech Connect

    Paranthaman, Mariappan Parans; Qiu, Xiaofeng; List III, Frederick Alyious; Zhang, Yifei; Li, Xiaoping; Sathyamurthy, Srivatsan; Thieme, C. L. H.; Rupich, M. W.

    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.

  3. HTS current lead units prepared by the TFA-MOD processed YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Shiohara, K.; Sakai, S.; Ishii, Y.; Yamada, Y.; Tachikawa, K.; Koizumi, T.; Aoki, Y.; Hasegawa, T.; Tamura, H.; Mito, T.

    2010-11-01

    Two superconducting current lead units have been prepared using ten coated conductors of the Tri-Fluoro-Acetate - Metal Organic Deposition (TFA-MOD) processed Y 1Ba 2Cu 3O 7-δ (YBCO) coated conductors with critical current ( Ic) of about 170 A at 77 K in self-field. The coated conductors are 5 mm in width, 190 mm in length and about 120 μm in overall thickness. The 1.5 μm thick superconducting YBCO layer was synthesized through the TFA-MOD process on Hastelloy™ C-276 substrate tape with two buffer oxide layers of Gd 2Zr 2O 7 and CeO 2. The five YBCO coated conductors are attached on a 1 mm thick Glass Fiber Reinforced Plastics (GFRP) board and soldered to Cu caps at the both ends. We prepared two 500 A-class current lead units. The DC transport current of 800 A was stably applied at 77 K without any voltage generation in all coated conductors. The voltage between both Cu caps linearly increased with increasing the applied current, and was about 350 μV at 500 A in both current lead units. According to the estimated values of the heat leakage from 77 K to 4.2 K, the heat leakage for the current lead unit was 46.5 mW. We successfully attained reduction of the heat leakage because of improvement of the transport current performance ( I c), a thinner Ag layer of YBCO coated conductor and usage of the GFRP board for reinforcement instead of a stainless steel board used in the previous study. The DC transport current of 1400 A was stably applied when the two current lead units were joined in parallel. The sum of the heat leakages from 77 K to 4.2 K for the combined the current lead units was 93 mW. In comparison with the conventional Cu current leads by gas-cooling, it could be noted that the heat leakage of the current lead is about one order of magnitude smaller than that of the Cu current lead.

  4. Biaxially aligned template films fabricated by inclined-substrate deposition for YBCO-coated conductor applications.

    SciTech Connect

    Ma, B.; Li, M.; Koritala, R. E.; Fisher, B. L.; Erck, R. A.; Dorris, S. E.; Miller, D. J.; Balachandran, U.

    2002-08-12

    Inclined substrate deposition (ISD) has the potential for rapid production of high-quality biaxially textured buffer layers, which are important for YBCO-coated conductor applications. We have grown biaxially textured MgO films by ISD at deposition rates of 20-100 {angstrom}/sec. Columnar grains with a roof-tile surface structure were observed in the ISD-MgO films. X-ray pole figure analysis revealed that the (002) planes of the ISD-MgO films are tilted at an angle from the substrate normal. A small {phi}-scan full-width at half maximum (FWHM) of {approx}9{sup o} was observed on MgO films deposited at an inclination angle of 55{sup o}. In-plane texture in the ISD MgO films developed in the first 0.5 {micro}m from the interface, then stabilized with further increases in film thickness. YBCO films deposited by pulsed laser deposition on ISD-MgO buffered Hastelloy C276 substrates were biaxially aligned with the c-axis parallel to the substrate normal. T{sub c} of 91 K with a sharp transition and transport J{sub c} of 5.5 x 10{sup 5} A/cm{sup 2} at 77 K in self-field were measured on a YBCO film that was 0.46-{micro}m thick, 4-mm wide, 10-mm long.

  5. High-material yield fabrication of YBCO coated conductors by Nd:YAG-PLD system

    NASA Astrophysics Data System (ADS)

    Ono, I.; Ichino, Y.; Yoshida, Y.; Yoshizumi, M.; Izumi, T.; Shiohara, Y.

    In order to fabricate superconducting coated conductors with lower cost, fabrication processes are required high material yield. We report an improvement of the material yield of YBCO films prepared by inside-plume Nd:YAG pulsed laser deposition method on metal substrates with an architecture of CeO2/LMO/IBAD-MgO/GZO/HastelloyTM. In this study, we shortened a distance from the target to the substrate (dT-S) in order to improve the material yield. Additionally, we have used Nd:YAG laser because initial and running costs are anticipated to be lower than those of excimer laser. As a result, by shorting the dT-S from 40 mm to 20 mm, the material yield increased on 10 mm×10 mm substrates. Additionally, by changing the O2 pressure (PO2) from 40 Pa to 400 Pa at dT-S = 20 mm, the material yield had a local maximal value of 18.6% at PO2=200 Pa. On multi-turn (MT) metal substrates, the material yield reached 56.0%. However, the critical current density (Jc) of the YBCO film which was deposited at dT-S = 20 mm and PO2=200 Pa on the 10 mm×10 mm substrate was 1.2 MA/cm2 at the edges and 0.2 MA/cm2 at the center at 77 K in self-field, although the YBCO films showed good aligned crystal textures. In order to improve this non-uniformity, we tilted the surface normal of the target 15 degree from a line connecting target and substrate. As a result, we achieved the uniformity in deposition rate. Then, we prepared YBa1.78Cu2.9Oy target to fabricate YBCO films with stoichiometric composition and obtained the uniform-high Jc.

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

    NASA Astrophysics Data System (ADS)

    Parans Paranthaman, M.; Sathyamurthy, S.; Li, Xiaoping; Specht, E. D.; Wee, S. H.; Cantoni, C.; Goyal, A.; Rupich, M. W.

    2010-03-01

    The pyrochlore Lanthanum Zirconium Oxide, La 2Zr 2O 7 (LZO), has been developed as a potential replacement barrier layer in the standard RABiTS three-layer architecture of physical vapor deposited CeO 2 cap/YSZ barrier/Y 2O 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 2O 3-ZrO 2 system. Using a metal-organic deposition (MOD) process, we have grown smooth, crack-free, epitaxial thin films of La xZr 1-xO y ( x = 0.2-0.6) on standard Y 2O 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 xZr 1-xO y. Both CeO 2 cap layers and MOD-YBCO films were grown epitaxially on these modified LZO barriers. High critical currents per unit width, Ic of 274-292 A/cm at 77 K and self-field were achieved for MOD-YBCO films grown on La xZr 1-xO 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 xZr 1-xO y ( x = 0.25) films were grown directly on biaxially textured Ni-3W substrates. About 3 μm thick YBCO films grown on a single MOD-LZO buffered Ni-3W substrates using pulsed laser deposition show a critical current density, Jc, of 0.55 MA/cm 2 ( Ic 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.

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

    SciTech Connect

    Paranthaman, Mariappan Parans; Sathyamurthy, Srivatsan; Li, Xiaoping; Specht, Eliot D; Wee, Sung Hun; Cantoni, Claudia; Goyal, Amit; Rupich, M. W.

    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.

  8. The mechanism of thermal runaway due to continuous local disturbances in the YBCO-coated conductor coil winding

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Y.; Okuyama, E.; Nakagome, H.; Takematsu, T.; Takao, T.; Hamada, M.; Matsumoto, S.; Kiyoshi, T.; Takizawa, A.; Takahashi, M.; Maeda, H.

    2012-07-01

    Though YBCO coils are stable against transient disturbances such as conductor motion, they suffer from thermal runaway at a current below the coil critical current due to continuous local disturbances attributed to partial degradation of the conductor in the coil winding. Continuous heat generation in the degraded layer induces thermal runaway in adjacent layers; thermal runaway does not occur in the degraded layer spontaneously due to the small n index of the degraded YBCO-coated conductor. The thermal runaway current depends on the cooling conditions of the winding. For a paraffin-impregnated YBCO coil under quasi-adiabatic conditions, the thermal runaway current is far below the coil critical current, while it is close to the coil critical current in the case of a dry-wound coil. The permissible temperature rise following a thermal runaway for YBCO conductors in the degraded layer is demonstrated to be 340 K. If the YBCO coils are operated at a temperature below 20 K, the current density, typically 600-800 A mm-2, is much higher than that at 77 K. Therefore, the time interval between thermal runaway initiation and the melting temperature becomes less than 0.5 s, posing a difficult problem for protection; i.e., thermal runaway due to continuous local disturbances is hazardous to the safe operation of high current density YBCO coils.

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

    NASA Astrophysics Data System (ADS)

    Takahashi, Y.; Kiuchi, M.; Otabe, E. S.; Matsushita, T.; Shikimachi, K.; Watanabe, T.; Kashima, N.; Nagaya, S.

    2010-11-01

    Ion Beam Assist Deposition/Chemical Vapor Deposition(IBAD/CVD)-processed YBCO-coated conductors with high critical current density Jc 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 μm. This property can be quantitatively characterized by the apparent pinning potential, U0∗. It is found that U0∗ takes a smaller value due to the two-dimensional pinning mechanism at high magnetic fields for conductor with thinner superconducting layer. Although U0∗ 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 U0∗ on the magnetic field, temperature and the layer thickness.

  10. VOLTAGE DISTRIBUTION AND MECHANICAL STRENGTH IN SPLICE JOINTS MADE FROM AS-MANUFACTURED YBCO COATED CONDUCTORS

    SciTech Connect

    Duckworth, Robert C; Zhang, Yifei; Gouge, Michael J; Rey, Christopher M; Van der Laan, Danko; Clickner, Cam

    2010-01-01

    With recommendations from wire manufacturers as a starting point, a series of solder joints were fabricated and characterized to determine the best method to produce repeatable, low-resistance and high-mechanical-strength splices in as-manufactured, stabilized YBCO coated conductors. From the 2.54 cm long splice joints that were fabricated, parameters such as solder material, stabilization material, fabrication method, and conductor geometry were varied to determine the impact of each on splice joint properties. Results indicate that the lowest resistance splice joints were influenced primarily by the tape orientation in the joint and the stabilization material. The lowest resistances were between 2 10-8 and 1.0 10-7 in 4-mm wide tapes and were obtained from pure copper stabilized tapes oriented with the YBCO layers in closest proximity. The voltage drop along the splice length indicated that only a fraction of the splice length contributes to the splice joint resistance. Mechanical characterization of splice joints showed that the joint resistance remained unchanged under axial stress up to a stress level at which the critical current of the tapes forming the joint degrades irreversibly.

  11. Inclined-substrate deposition of biaxially textured magnesium oxide thin films for YBCO coated conductors.

    SciTech Connect

    Ma, B.; Li, M.; Jee, Y. A.; Koritala, R. E.; Fisher, B. L.; Balachandran, U.; Energy Technology

    2002-02-01

    Highly textured MgO films were grown by the inclined-substrate deposition (ISD) technique at a high deposition rate. A columnar grain with a roofing-tile-shaped surface was observed in these MgO films. X-ray pole figure, and {phi}- and {omega}-scan were used to characterize in-plane and out-of-plane textures. MgO films deposited when the incline angle {alpha} was 55 and 30 degrees exhibited the best in-plane and out-of-plane texture, respectively. High-quality YBCO films were epitaxially grown on ISD-MgO-buffered Hastelloy C substrates by pulsed laser deposition. {Tc}=88 K, with sharp transition, and j{sub c} values of {approx}2x10{sup 5} A/cm{sup 2} at 77 K in zero field were observed on films 5 mm wide and 1 cm long. This work has demonstrated that biaxially textured ISD MgO buffer layers deposited on metal substrates are excellent candidates for fabrication of high-quality YBCO coated conductors.

  12. On the use of copper-based substrates for YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Vannozzi, A.; Fabbri, F.; Augieri, A.; Angrisani Armenio, A.; Galluzzi, V.; Mancini, A.; Rizzo, F.; Rufoloni, A.; Padilla, J. A.; Xuriguera, E.; De Felicis, D.; Bemporad, E.; Celentano, G.

    2014-05-01

    It is well known that the recrystallization texture of heavily cold-rolled pure copper is almost completely cubic. However, one of the main drawbacks concerning the use of pure copper cube-textured substrates for YBCO coated conductor is the reduced secondary recrystallization temperature. The onset of secondary recrystallization (i.e., the occurrence of abnormal grains with unpredictable orientation) in pure copper substrate was observed within the typical temperature range required for buffer layer and YBCO processing (600-850 °C). To avoid the formation of abnormal grains the effect of both grain size adjustment (GSA) and recrystallization annealing was analyzed. The combined use of a small initial grain size and a recrystallization two-step annealing (TSA) drastically reduced the presence of abnormal grains in pure copper tapes. Another way to overcome the limitation imposed by the formation of abnormal grains is to deposit a buffer layer at temperatures where secondary recrystallization does not occur. For example, La2Zr2O7 (LZO) film with a high degree of epitaxy was grown by metal-organic decomposition (MOD) at 1000 °C on pure copper substrate. In several samples the substrate underwent secondary recrystallization. Our experiments indicate that the motion of grain boundaries occurring during secondary recrystallization process does not affect the quality of LZO film.

  13. Factors associated with biaxial texturing of Cu tapes for YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Kim, Y. H.; Sung, T. H.; Han, S. C.; Han, Y. H.; Jeong, N. H.; Kim, C. J.; Jun, B. H.; Oh, S. S.; Kim, H. S.; Kim, T. H.; No, K. S.

    2007-10-01

    A biaxially textured Cu(2 0 0) tape was used as a substrate for YBCO coated conductors by cold rolling followed by recrystallization heat treatment. In this work, we studied the influence of annealing conditions and final tape thickness on the recrystallization process. Phi (ϕ) scan and omega (ω) scan XRD revealed that the best in-plane and out-of-plane alignment of the Cu tape (thickness 100 μm), measured in terms of full width half maximum (FWHM) values of 6.64° and 4.49°, were obtained by annealing at 800 °C for 30 min. The texture of CeO2 buffer layer thermally-evaporated on the Cu tape was also analyzed.

  14. High-Tc Coated Conductors - Performance of Meter-Long YBCO/IBAD Flexible Tapes

    SciTech Connect

    Foltyn, S.R.; Arendt, P.N.; Dowden, P.C.; DePaula, R.F.; Groves J.R.; Coulter, J.Y.; Jia, Q.; Maley, M.P.; Peterson, D.E.

    1998-09-13

    One meter long tapes based on 50-100 {micro}m thick by 1 cm wide nickel alloy substrates have been coated in a continuous process with a textured yttria-stabilized zirconia layer by ion beam-assisted deposition, followed by a 1-2 {micro}m thick layer of YBCO by pulsed laser deposition. The best result to date is a tape with a critical current (I{sub c}) at 75 K of 96 A over an 87 cm measurement length. The overall critical current density and engineering current density are 1 MA/cm{sup 2} and 10 kA/cm{sup 2}, respectively. Using a special probe, individual I-V curves were generated for each centimeter of tape length in order to investigate longitudinal uniformity of the transport properties: the highest and lowest I{sub c} values fall within a range of {+-}25%.

  15. Engineered oxide thin films as 100% lattice match buffer layers for YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Akin, Y.; Heiba, Z. K.; Sigmund, W.; Hascicek, Y. S.

    2003-12-01

    One of the most important qualities of buffer layers for RE-BCO coated conductors' growth is close lattice match with RE-BCO. However, there is no natural material with a 100% lattice match with RE-BCO. In this study mixtures of europium oxide (Eu 2O 3) and ytterbium oxide (Yb 2O 3), (Eu 1- uYb u) 2O 3 (0.0⩽ u⩽1.0), were investigated as a candidate buffer layer that could have same lattice parameter as YBa 2Cu 3O 7- δ(YBCO). Because the pseudocubic lattice parameter of Eu 2O 3 is bigger, and that of Yb 2O 3 is smaller than lattice parameter of YBCO, and the mixed oxides with appropriate ratio would have same lattice parameter of YBCO. The mixtures were prepared using metal-organic precursor by sol-gel process, and it was found that all mixed samples are single phase, complete solid solutions, and have same crystal system over the whole range of " u". Lattice parameters of mixed (Eu 1- uYb u) 2O 3 oxide powders were changed between 10.86831 and 10.42828 Å which are lattice parameter of Eu 2O 3 and Yb 2O 3, respectively by changing the ratio of Eu/Yb in the mixture. Phase and lattice parameter analysis revealed that pseudocubic lattice parameter of (Eu 0.893Yb 0.107) 2O 3 is 3.82 Å which is same as the lattice parameter of YBCO. Textured (Eu 0.893Yb 0.107) 2O 3 buffer layers were grown on biaxially textured-Ni (1 0 0) substrates. The solution was prepared from Europium and Ytterbium 2,4-pentadioanate, and was deposited on the Ni substrates using a reel-to-reel sol-gel dip coating system. The textured films were annealed at 1150 °C for 10 min under 4% H 2-Ar gas flow. Extensive texture analysis has been done to characterize the texture of (Eu 0.893Yb 0.107) 2O 3 buffer layers. X-ray diffraction (XRD) of the buffer layer showed strong out-of-plane orientation on Ni tape. The (Eu 0.893Yb 0.107) 2O 3 (2 2 2) pole figure indicated a single cube-on-cube textured structure. The omega and phi scans revealed good out-of-plane and in-plane alignments. The full

  16. Fabrication of YSZ buffer layer by single source MOCVD technique for YBCO coated conductor

    NASA Astrophysics Data System (ADS)

    Jun, Byung-Hyuk; Sun, Jong-Won; Kim, Ho-Jin; Lee, Dong-Wook; Jung, Choong-Hwan; Park, Soon-Dong; Kim, Chan-Joong

    2003-10-01

    Yttria stabilized zirconia (YSZ) buffer layers were deposited by a metal organic chemical vapor deposition technique using a single liquid source for the application of YBa 2Cu 3O 7- δ (YBCO) coated conductor. Y:Zr mole ratio was 0.2:0.8, and tetrahydrofuran (THF) was used as a solvent. The (1 0 0) single crystal MgO substrate was used for searching the deposition conditions. Bi-axially oriented CeO 2 and NiO films were fabricated on {1 0 0} <0 0 1> textured Ni substrate by the same method and used as templates. At a constant working pressure of 10 Torr, the deposition temperatures (660-800 °C) and oxygen flow rates (100-500 sccm) were changed to find the optimum deposition condition. The best (1 0 0) oriented YSZ film on MgO was obtained at 740 °C and O 2 flow rate of 300 sccm. For a YSZ buffer layer with this deposition condition on a CeO 2/Ni template, full width half maximum values of the in-plane ( ϕ-scan) and out-of-plane ( ω-scan) alignments were 10.6° and 9.8°, respectively. The SEM image of YSZ film on CeO 2/Ni showed surface morphologies without microcracks. The film deposition rate was about 100 nm/min.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Grain morphology of YBCO coated superconductors prepared by spin process on Ni substrate

    NASA Astrophysics Data System (ADS)

    Liu, C. F.; Du, S. J.; Yan, G.; Xi, W.; Wu, X.; Pang, Y.; Wang, F. Y.; Liu, X. H.; Feng, Y.; Zhang, P. X.; Wu, X. Z.; Zhou, L.

    2003-04-01

    The YBCO thick films with c-axis preferred orientation were prepared by spin and printing processes on Ni substrates (including cold rolling Ni, cube textured Ni, and cube textured Ni+ self-oxided NiO ). The results show that the chrysanthemum (or spherulite) and polygon morphology grains dominate the microstructure of YBCO films. The chrysanthemum size is about 0.2-0.5 mm range, some reaches 1 mm, and polygon grains normally are placed in the center of the chrysanthemum grains. No chrysanthemum grains appear in the thick films prepared on the substrate with Ag or YBCO intermediate layers.

  19. AC over-current characteristics of YBCO coated conductor with copper stabilizer layer considering insulation layer

    NASA Astrophysics Data System (ADS)

    Du, H.-I.; Kim, M.-J.; Kim, Y.-J.; Lee, D.-H.; Han, B.-S.; Song, S.-S.

    2010-11-01

    Compared with the first-generation BSCCO wire, the YBCO thin-film wire boasts low material costs and high Jc and superior magnetic-field properties, among other strengths. Meanwhile, the previous BSCCO wire material for superconducting cables has been researched on considerably with regard to its post-wire quenching characteristics during the application of an alternating over-current. In this regard, the promising YBCO thin-film wire has yet to be further researched on. Moreover, still lacking is research on the YBCO thin-film wire with insulating layers, which is essential in the manufacture of superconducting cables, along with the testing of the application of an alternating over-current to the wire. In this study, YBCO thin-film wires with copper-stabilizing layers were used in testing alternating over-current application according to the presence or absence of insulating layers and to the thickness of such layers, to examine the post-quenching wire resistance increase and quenching trends. The YBCO thin-film wire with copper-stabilizing layers has a critical temperature of 90 K and a critical current of 85 A rms. Moreover, its current application cycle is 5.5 cycles, and its applied currents are 354, 517, 712, and 915 A peak. These figures enabled the YBCO thin-film wires with copper-stabilizing layers to reach 90, 180, 250, and 300 K, respectively, in this study. These temperatures serve as a relative reference to examine the post-quenching wire properties following the application of an alternating over-current.

  20. Effect of Interim Annealing on Mechanical Strength of TFA-MOD Derived YBCO Coated Conductors

    NASA Astrophysics Data System (ADS)

    Takagi, Y.; Nakaoka, K.; Nakamura, T.; Yoshizumi, M.; Kiss, T.; Izumi, T.; Shiohara, Y.

    TFA-MOD derived YBCO tapes are expected for many applications due to cost-efficiency. In some applications, uniformity and mechanical strength are required for tapes. A 205 m-long YBCO tape was fabricated with high and uniform Ic performance throughout the tape by adopting the interim annealing before the conversion process. The effect of the interim annealing on the crystal growth mechanism of YBCO has been studied focusing on the relationship between the interim annealing conditions and delamination, in this work. Delamination strength was evaluated in the samples prepared with and without interim annealing by the stud pull method. Measurements were carried out on 50 different points for each sample and the results were analyzed statistically. The difference between the two samples was remarkably seen in the delamination strength below 60 MPa. The conventionally annealed sample had more points with low delamination strength below 60 MPa than the interim annealed one. The cross sectional images of both samples observed by SEM showed that there were few pores within the interim annealed superconducting layer, although conventional superconducting layer had many pores. These results suggest that the pores within YBCO layer might be origins to be propagated for delamination at low strength.

  1. Temperature and Magnetic Field Dependence of Critical Currents in YBCO Coated Conductors with Processing-Induced Variations in Pinning Properties

    SciTech Connect

    Gapud, Albert Agcaoili; Feenstra, Roeland; Christen, David K; Thompson, James R; Holesinger, T. G.

    2005-01-01

    Several applications of high-temperature super-conducting wire require high currents at intermediate magnetic fields B and over a range of orientations; however, such conditions are at present achievable only at low temperatures (-30 K). The goal of this study is to determine the feasibility of higher operating temperatures for these applications by investigating temperature dependent, low- and high-field pinning properties of YBCO coated conductor samples. The YBCO films were grown on RABiTS templates by a PVD ex situ BaF{sub 2} process. Variations in pinning properties were induced by introducing excess yttrium (Y) in the precursor and controllably increasing the growth rate. The main result is a more uniform dependence of J{sub c} over all orientations of B, along with high irreversibility field B{sub irr} and high critical current densities J{sub c}. Results also show that for films with various pinning properties and processed under different conditions the self-field J{sub c} at 77 K is an effective indicator of performance in the temperatures and fields of interest.

  2. H-formulation for simulating levitation forces acting on HTS bulks and stacks of 2G coated conductors

    NASA Astrophysics Data System (ADS)

    Sass, F.; Sotelo, G. G.; Junior, R. de Andrade; Sirois, Frédéric

    2015-12-01

    Several techniques to model high temperature superconductors (HTSs) are used throughout the world. At the same time, the use of superconductors in transportation and magnetic bearings promises an increase in energy efficiency. However, the most widespread simulation technique in the literature, the H-formulation, has not yet been used to simulate superconducting levitation. The goal of this work is to present solutions for the challenges concerning the use of the H-formulation to predict the behavior of superconducting levitators built either with YBCO bulks or stacks of 2G wires. It is worth mentioning the originality of replacing bulks with HTS stacks in this application. In our simulation methodology, the movement between the HTS and the permanent magnet was avoided by restricting the simulation domain to the HTS itself, which can be done by applying appropriate boundary conditions and analytical expressions for the source field. Commercial finite element software was used for the sake of ease of implementation. Simulation results were compared with experimental data, showing good agreement. We conclude that the H-formulation is suitable for problems involving moving objects and is a good alternative to other approaches for simulating superconducting magnetic bearings.

  3. Change in fatigue property and its relation to critical current for YBCO coated conductor with additional Cu layer

    NASA Astrophysics Data System (ADS)

    Yoshida, Y.; Hojo, M.; Sugano, M.; Adachi, T.; Inoue, Y.; Shikimachi, K.; Hirano, N.; Nagaya, S.

    2009-10-01

    YBa 2Cu 3O 7-δ, (YBCO) coated conductors with an additional Cu layer are expected to be applied as coils used in superconducting magnetic energy storage, SMES. In the operation of SMES, large cyclic hoop stress is applied to the coated conductor in the longitudinal direction. In the present study, we carried out fatigue tests in liquid nitrogen, LN 2, and measured the critical current, I c, after a specific number of fatigue cycles to clarify its fatigue fracture mechanism. All fatigue tests were carried out under a stress ratio (the ratio of the minimum to maximum load) of 0.5. The frequency of stress cycling was 30 Hz. Our results showed that the addition of a Cu layer increased the fatigue strength after 10 6 cycles, F, by about 19%. Decrease of I c was more than 30% of the initial critical current, I c0, without loading at the point of final overall fracture when the maximum load in the stress cycles was close to that corresponding to irreversible strain. Furthermore, microscopic observation and the change in I c showed that fatigue fracture mainly initiated from the Hastelloy C-276 substrate. Fatigue fracture also initiated from the Cu layer, but only when the maximum load was approximately F.

  4. Growth of epitaxial Y 2O 3 buffer layers on biaxially textured Ni-W substrates for YBCO coated conductors by MOD approach

    NASA Astrophysics Data System (ADS)

    Bhuiyan, M. S.; Paranthaman, M.; Kang, S.; Lee, D. F.; Salama, K.

    2005-06-01

    We have grown epitaxial Y 2O 3 buffer layers on biaxially textured Ni-W substrates for YBCO coated conductors using a newly developed metal organic decomposition (MOD) approach. Y 2O 3 precursor solution of 0.25 M concentration was spin coated on short samples of Ni-3 at.%W (Ni-W) substrates and heat-treated at 1150 °C in a gas mixture of Ar-4% H 2 for an hour. Detailed X-ray studies indicate that Y 2O 3 films have good out-of-plane and in-plane textures with full-width-half-maximum values of 6.22° and 7.51°, respectively. SEM and AFM investigations of Y 2O 3 films reveal a fairly dense and smooth microstructure without cracks and porosity. Highly textured YSZ barrier layers and CeO 2 cap layers were deposited on MOD Y 2O 3-buffered Ni-W substrates using rf-magnetron sputtering. Pulsed laser deposition was used to grow YBCO films on these substrates. A critical current, Jc, of about 1.21 MA/cm 2 at 77 K and self-field was obtained on YBCO (PLD)/CeO 2 (sputtered)/YSZ (sputtered)/Y 2O 3 (spin-coated)/Ni-W.

  5. MOD approach for the growth of epitaxial CeO2 buffer layers on biaxially textured Ni W substrates for YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Bhuiyan, M. S.; Paranthaman, M.; Sathyamurthy, S.; Aytug, T.; Kang, S.; Lee, D. F.; Goyal, A.; Payzant, E. A.; Salama, K.

    2003-11-01

    We have grown epitaxial CeO2 buffer layers on biaxially textured Ni-W substrates for YBCO coated conductors using a newly developed metal organic decomposition (MOD) approach. Precursor solution of 0.25 M concentration was spin coated on short samples of Ni-3 at%W (Ni-W) substrates and heat-treated at 1100 °C in a gas mixture of Ar-4%H2 for 15 min. Detailed x-ray studies indicate that CeO2 films have good out-of-plane and in-plane textures with full-width-half-maximum values of 5.8° and 7.5°, respectively. High temperature in situ XRD studies show that the nucleation of CeO2 films starts at 600 °C and the growth completes within 5 min when heated at 1100 °C. SEM and AFM investigations of CeO2 films reveal a fairly dense microstructure without cracks and porosity. Highly textured YSZ barrier layers and CeO2 cap layers were deposited on MOD CeO2-buffered Ni-W substrates using rf-magnetron sputtering. Pulsed laser deposition (PLD) was used to grow YBCO films on these substrates. A critical current, Jc, of about 1.5 MA cm-2 at 77 K and self-field was obtained on YBCO (PLD)/CeO2 (sputtered)/YSZ (sputtered)/CeO2 (spin-coated)/Ni-W.

  6. Low AC Loss YBCO Coated Conductor Geometry by Direct Inkjet Printing

    SciTech Connect

    Rupich, Martin, Dr.; Duckworth, Robert, Dr.

    2009-10-01

    The second generation (2G) high temperature superconductors (HTS) wire offers potential benefits for many electric power applications, including ones requiring filamentized conductors with low ac loss, such as transformers and fault current limiters. However, the use of 2G wire in these applications requires the development of both novel multi-filamentary conductor designs with lower ac losses and the development of advanced manufacturing technologies that enable the low-cost manufacturing of these filamentized architectures. This Phase I SBIR project focused on testing inkjet printing as a potential low-cost, roll-to-roll manufacturing technique to fabricate potential low ac loss filamentized architectures directly on the 2G template strips.

  7. Demonstration of High Current Density YBCO Coated Conductors on RE2O3-Buffered Ni Substrates with Two New Alternative Architectures

    SciTech Connect

    Beach, D.B.; Chirayil, T.G.; Christen, D.K.; Cui, X.; Feenstra, R.; Goyal, A.; Kroeger, D.M.; Lee, D.F.; Martin, P.M.; Mathis, J.E.; Morrell, J.S.; Norton, D.P.; Paranthaman, M.; Specht, E.D.; Verebelyi, D.T.

    1999-07-12

    In continuation of our effort to develop single buffer layer architectures for YBCO (YBa2Cu3O7-g) coated tape conductors, we have studied RE2O3 (RE = Y, and rare earths) as candidate materials. Three types of crystal structures including the preferred cubic phase are known for the rare earth oxides. High quality simple cubic RE2O3 buffer layers were grown epitaxiahy on {100}<001> textured Ni substrates using both reactive evaporation and sol-gel processing. Detailed X-ray studies have shown that the Y2O3, Eu2O3, Gd2O3, and Yb2O3 were grown with a single epitaxial orientation. SEM micrographs indicated that both e-beam and sol-gel grown films were dense, continuous and crack free. High Jc YBCO films were grown on RE2O3-buffered Ni substrates with sputtered cap layers. Two new alternative buffer layer architectures were developed. A high Jc of 1.8 MA/cm2 at 77 K and self-field was obtained on YBCO films with a layer sequence of YBCO (pulsed laser deposition)/Yb2O3 (sputtered)/Y2O3 (e-beam)/Ni. Also, a high Jc of over 1 MA/cm2 at 77 K and self-field was obtained on YBCO films with a layer sequence of YBCO (ex-situ BaF2 process)/CeO2 (sputtered)YSZ sputtered)/RE2O3 (sol-gel or e-beam)Ni. The performance of sol-gel grown buffers approached the quality of e-beam grown buffers.

  8. The role of a-axis grains in the transition to the normal state of YBa{sub 2}Cu{sub 3}O{sub 7−δ} films and of 2G-coated conductors when induced by high electrical current densities

    SciTech Connect

    Bernstein, P. Harnois, C.; Mc Loughlin, C.; Noudem, J.; Thimont, Y.; Ferro, G.; Osorio, M. R.; Veira, J. A.; Vidal, D.; Vidal, F.

    2014-02-07

    The influence of surface defects, in particular of a-axis grains, on the transition to the normal state induced by high current densities in YBa{sub 2}Cu{sub 3}O{sub 7−δ} (YBCO) thin films and in a commercial 2G-coated conductor is investigated. For that purpose, the surface of the samples is observed by scanning electron microscopy and isothermal current-voltage curves are measured at different temperatures with pulsed currents up to the quenching value I*. The results show that the ratio of I* to the critical current is large if a-axis grains are not visible at the surface of the YBCO films, while it is much lower if the surface includes a-axis grains as this is the case for the coated conductor. The connection between the transition onset and the vortex dynamics, as well as the role of the a-axis grains in this process are discussed. The relation between the I* values obtained from thermal calculations and those resulting from vortex dynamics considerations is also discussed, as well as the possible consequences suggested by this work for the different applications of the coated conductors.

  9. Insert Coil Test for HEP High Field Magnets Using YBCO Coated Conductor Tapes

    SciTech Connect

    Lombardo, V.; Barzi, E.; Turrioni, D.; Zlobin, A.V.; /Fermilab

    2011-06-15

    The final beam cooling stages of a Muon Collider may require DC solenoid magnets with magnetic fields of 30-50 T. In this paper we present progress in insert coil development using commercially available YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} Coated Conductor. Technological aspects covered in the development, including coil geometry, insulation, manufacturing process and testing are summarized and discussed. Test results of double pancake coils operated in liquid nitrogen and liquid helium are presented and compared with the performance of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} tape short samples.

  10. High Jc YBCO coated conductors on non-magnetic metallic substrate using YSZ-based buffer layer architecture

    NASA Astrophysics Data System (ADS)

    Celentano, G.; Boffa, V.; Ciontea, L.; Fabbri, F.; Galluzzi, V.; Gambardella, U.; Mancini, A.; Petrisor, T.; Rogai, R.; Rufoloni, A.; Varesi, E.

    2002-08-01

    Biaxially aligned YBa 2Cu 3O 7- δ (YBCO) thick films were deposited by pulsed laser ablation technique on cube textured non-magnetic Ni 89V 11 (Ni-V) substrate, using CeO 2/YSZ/CeO 2/NiO buffer layer architecture. The first NiO seed layer was formed by epitaxial oxidation of the Ni-V substrate. Structural analyses show typical full width at half maximum values of φ- and ω-scans less than 10° and 8°, respectively. The highest value obtained for the critical current density at 77 K and zero magnetic field was 6×10 5 A cm -2, which is close to that obtained for YBCO films grown on CeO 2/NiO buffer layer architecture.

  11. Epitaxial Growth Of Y2O3 On Biaxially Textured Ni Tapes Using A Sol-Gel Process For YBCO Coated Conductors

    NASA Astrophysics Data System (ADS)

    Ciontea, L.; Ristoiu, T.; Suciu, R.-C.; Petrisor, T.

    2007-04-01

    A solution processing technique was used to deposit an epitaxial Y2O3 film on (001)[100] cube textured Ni tapes for YBa2Cu3Ox (YBCO) coated conductors manufacturing. The cube texture was developed in Ni by a conventional thermo-mechanical process. A precursor solution of yttrium 2-methoxyethoxide in 2-methoxyethanol was spin-coated on the Ni substrate. The as-deposited amorphous film was thermally treated at 1100°C in a flowing Ar+4%H2 gas mixture. The θ-2θ X-ray spectra revealed predominantly (001) reflections, indicating a high degree of out-of-plane orientation. Pole figures for the (222) Y2O3 reflections demonstrate a single in-plane texture. The out-of-plane and in-plane epitaxial relationship is [400]Y2O3//[200] Ni and [110]Y2O3//[100] Ni, respectively. The full-width-half-maximum (FWHM) of the ω-scans and φ-scans is 6° and 11°, respectively.

  12. Development of cube textured Ni 5at.%W alloy substrates for YBCO coated conductor application using a powder metallurgy process

    NASA Astrophysics Data System (ADS)

    Kim, S.-S.; Tak, J.-S.; Bae, S.-Y.; Chung, J.-K.; Ahn, I.-S.; Kim, C.-J.; Kim, K.-W.; Cho, K.-K.

    2007-10-01

    In this paper, Ni-5at.%W alloy substrate for YBCO coated conductor was fabricated by a dry powder metallurgy process including powder compaction, cold isostatic pressing (CIP), cold rolling and annealing for recrystallization. Ni and W powders were ball-milled at this process for various times of 10, 30, 50 and 100 h in argon atmosphere. The rod-like Ni-W alloy compacts were sintered at 1150 °C for 1 h in 96%Ar-4%H2 atmosphere. The sintered rods were cold rolling into thin tape of 70-90 μm thickness with 5% reduction at each path. The Ni-W alloy tapes were annealed at 800-1200 °C in an atmosphere of 96%Ar-4%H2 mixing gas for the development of cube texture. The tape with the best properties of low surface roughness, small grain size and strong cube texture was obtained at the condition annealed at 1200 °C using ball-milled powder for 30 min. The W addition to Ni improved the mechanical properties by solid solution hardening and inhibited grain growth for annealing heat treatment. The tapes were characterized by X-ray pole-figure, optical microscopy (OM), scanning electron microscopy (SEM) and scanning probe microscopy (SPM).

  13. Temperature dependence of critical current and transport current losses of 4 mm YBCO coated conductors manufactured using nonmagnetic substrate

    NASA Astrophysics Data System (ADS)

    Kvitkovic, J.; Hatwar, R.; Pamidi, S. V.; Fleshler, S.; Thieme, C.

    2015-12-01

    The temperature dependence of the critical current and AC losses were measured on American Superconductor Corporation's (AMSC) second generation high temperature superconducting (2G HTS) wire produced by Rolling Assisted Biaxially Textured Substrate (RABiTS) and Metal Organic Deposition (MOD) process. Wires manufactured with two types of substrates were characterized. The magnetic substrate with composition Ni5a%W exhibits a magnetic signature and has non-negligible AC losses in AC power applications. A new nonmagnetic substrate with an alloy composition Ni9a%W has been developed by AMSC to address the AC losses in 2G HTS. The data presented show that the performance of the new conductor is identical to the conductor with magnetic substrate in terms of critical current density. The data on AC losses demonstrate the absence of ferromagnetic loss component in the new conductor and significantly reduced AC losses at low to moderate values of I/Ic. The reduced losses will translate into reduced capital costs and lower operating costs of superconducting electrical devices for AC applications.

  14. MOD Buffer/YBCO Approach to Fabricate Low-Cost Second Generation HTS Wires

    SciTech Connect

    Paranthaman, Mariappan Parans; Sathyamurthy, Srivatsan; Bhuiyan, Md S; Martin, Patrick M; Aytug, Tolga; Kim, Kyunghoon; Fayek, Mostafa; Leonard, Keith J; Li, Jing; Zhang, W.; Rupich, Marty

    2007-01-01

    The metal organic deposition (MOD) of buffer layers on RABiTS substrates is considered a potential, low-cost approach to manufacturing high performance Second Generation (2G) high temperature superconducting (HTS) wires. The typical architecture used by American Superconductor in their 2G HTS wire consists of a Ni-W (5 at.%) substrate with a reactively sputtered Y2O3 seed layer, YSZ barrier layer and a CeO2 cap layer. This architecture supports critical currents of over 300 A/cm-width (77 K, self-field) with 0.8 mum YBCO films deposited by the TFA-MOD process. The main challenge in the development of the MOD buffers is to match or exceed the performance of the standard vacuum deposited buffer architecture. We have recently shown that the texture and properties of MOD - La2Zr2Ogamma (LZO) barrier layers can be improved by inserting a thin sputtered Y2O3 seed layer and prepared MOD deposited LZO layers followed by MOD or RF sputtered CeO2 cap layers that support MOD-YBCO films with Ic's of 200 and 255 A/cm-width, respectively. Detailed X-ray and microstructural characterizations indicated that MOD - CeO2 cap reacted completely with MOD YBCO to form BaCeOs. However, sputtered CeO2 cap/MOD YBCO interface remains clean. By further optimizing the coating conditions and reducing the heat-treatment temperatures, we have demonstrated an Ic of 336 A/cm with improved LZO layers and sputtered CeO2 cap and exceeded the performance of that of standard vacuum deposited buffers.

  15. A study on the required performance of a 2G HTS wire for HTS wind power generators

    NASA Astrophysics Data System (ADS)

    Sung, Hae-Jin; Park, Minwon; Go, Byeong-Soo; Yu, In-Keun

    2016-05-01

    YBCO or REBCO coated conductor (2G) materials are developed for their superior performance at high magnetic field and temperature. Power system applications based on high temperature superconducting (HTS) 2G wire technology are attracting attention, including large-scale wind power generators. In particular, to solve problems associated with the foundations and mechanical structure of offshore wind turbines, due to the large diameter and heavy weight of the generator, an HTS generator is suggested as one of the key technologies. Many researchers have tried to develop feasible large-scale HTS wind power generator technologies. In this paper, a study on the required performance of a 2G HTS wire for large-scale wind power generators is discussed. A 12 MW class large-scale wind turbine and an HTS generator are designed using 2G HTS wire. The total length of the 2G HTS wire for the 12 MW HTS generator is estimated, and the essential prerequisites of the 2G HTS wire based generator are described. The magnetic field distributions of a pole module are illustrated, and the mechanical stress and strain of the pole module are analysed. Finally, a reasonable price for 2G HTS wire for commercialization of the HTS generator is suggested, reflecting the results of electromagnetic and mechanical analyses of the generator.

  16. Chemical Solution Based Epitaxial Oxide Filmes on Biaxially Textured Ni-W Substrates with Improved Out-of-Plane Texture for YBCO Coated Conductors

    SciTech Connect

    Bhuiyan, Md S; Paranthaman, Mariappan Parans; Sathyamurthy, Srivatsan

    2007-01-01

    Epitaxial films of rare-earth (RE) niobates (where the rare earth includes La, Ce, and Nd) and lanthanum tantalate with pyrochlore structures were grown directly on biaxially textured nickel-3 at.% tungsten (Ni-W) substrates using a chemical solution deposition (CSD) process. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis revealed the surface morphology of the films to be smooth and homogeneous. Detailed X-ray diffraction analysis showed that the films of pyrochlore RE niobate and La-tantalate are highly textured with cube-on-cube epitaxy. The overall texture quality of the films was investigated by measuring the full-width half-maximum (FWHM) of the (004) and (222) rocking curves. We observed a sharper texture for both lanthanum niobate (La{sub 3}NbO{sub 7}) and lanthanum tantalate (La{sub 3}TaO{sub 7}) films compared to the underlying Ni-W substrate, though they have a larger lattice misfit with the Ni-W substrates. These results were comparable to the texture improvement observed in vacuum-deposited Y{sub 2}O{sub 3} seed layers. Texture improvement in the seed layer is the key towards obtaining YBCO films with a higher critical current density. Hence, solution-deposited La{sub 3}NbO{sub 7} and La{sub 3}TaO{sub 7} films can be used as a seed layer towards developing all metalorganic-deposited (MOD) buffer/YBCO architectures.

  17. Study on Quench Protection of HTS Coil Wound of YBCO Conductor

    NASA Astrophysics Data System (ADS)

    Fu, Youkun; Tsukamoto, Osami; Furuse, Mitsuho

    Recent progress of long YBCO coated conductors is remarkable and coils wound of YBCO conductors will be developed in near future. YBCO coated conductors that are made by deposition of thin YBCO film on high resistance metal substrates such as Hastelloy and nickel tapes are highly resistive when they are quenched. Therefore, measures for stabilization and quench protection are more important for YBCO conductors than for Bi/Ag sheathed tapes which have low resistive silver matrix. Though HTS conductors working at liquid nitrogen temperature are hard to be quenched, the conductors still have possibilities of quenches due to local defects for example. We studied necessary amount of copper stabilizer to protect the YBCO conductors in coils from damages caused by hot spots due to quenches. In the work we numerically calculated maximum hot spot temperature of a YBCO conductor quenched by a local disturbance during the sequence of quench detection and energy dump. In the analysis, necessary amounts of copper to keep the maximum hot spot temperature below a threshold are calculated. Based on the analysis, optimum conductor design is discussed to obtain safe and high current density conductors.

  18. Direct deposition of YBCO on polished Ag substrates by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Ma, B.; Li, M.; Koritala, R. E.; Fisher, B. L.; Dorris, S. E.; Maroni, V. A.; Miller, D. J.; Balachandran, U.

    2002-09-01

    YBCO thin films were directly deposited on mechanically polished nontextured silver (Ag) substrates at elevated temperature by pulsed laser deposition with various inclination angles of 35°, 55°, and 72°. Strong fiber texture, with the c-axis parallel to the substrate normal was detected by X-ray diffraction pole figure analysis. Atomic force microscopy and scanning electron microscopy images revealed that a few a-axis-oriented grains were dispersed on the top surface of the YBCO films. Transmission electron microscopy revealed dense amorphous layer at the interface between the YBCO film and the Ag substrate. Energy dispersive spectrum analysis indicates that the YBCO film deposited on the Ag substrate is slightly Cu-deficient. A YBCO film deposited at 755 °C and an inclination angle of 55° exhibited Tc=90 K. Transport critical current density measured by the four-probe method at 77 K in self-field was ≈2.7×10 5 A/cm 2. This work demonstrated a simple and inexpensive method to fabricate YBCO-coated conductors with high critical current density.

  19. Electrospinning of superconducting YBCO nanowires

    NASA Astrophysics Data System (ADS)

    Duarte, Edgar A.; Rudawski, Nicholas G.; Quintero, Pedro A.; Meisel, Mark W.; Nino, Juan C.

    2015-01-01

    YBa2Cu3O7-δ (YBCO) nanowires with critical transition temperature Tc = 91.7 K were synthesized by an electrospinning process with the use of sol-gel precursors. A homogeneous polymeric solution containing Y, Ba, and Cu acetates was electrospun, resulting in collections of randomly oriented nanowires as well as bundles of aligned nanowires. Fully crystallized YBCO nanowires were obtained after calcination at temperatures as low as 820 °C. The morphology, microstructure, and crystal structure were investigated, and the diameters of the polycrystalline nanowires varied between 120 and 550 nm depending on the viscosity of the precursors. Thinner individual wires, with diameters in the 50-80 nm range, were synthesized with a single grain structure across the entire wire cross-section.

  20. Deposition of YBCO films by high temperature spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Shields, T. C.; Abell, J. S.; Button, T. W.; Chakalov, R. A.; Chakalova, R. I.; Cai, C.; Haessler, W.; Eickemeyer, J.; de Boer, B.

    2002-08-01

    The fabrication of YBCO coated conductors on flexible textured metallic substrates requires the deposition of biaxially textured buffer layers and superconducting films. In this study we have prepared YBCO thin films on single crystal SrTiO 3 substrates and cube textured Ni substrates by spray pyrolysis. The Ni substrates have been pre-buffered with CeO 2/YSZ/CeO 2, layers deposited by pulsed laser deposition. Spray pyrolysis of nitrate solutions has been performed directly on heated substrates at temperatures between 800 and 900 °C without need for a subsequent annealing step. YBCO films deposited on both types of substrate are biaxially textured. Full width half maximum values determined from φ-scans are 8° and 20° for films on SrTiO 3 and buffered Ni substrates respectively. A transport Jc value of 1.2×10 5 A/cm 2 at 77 K and zero field has been achieved on SrTiO 3 ( T c onset=91 K, ΔTc=6 K). χ ac susceptibility measurements of films on buffered Ni substrates show Tc onsets of 88 K with ΔTc=18 K.

  1. The Effect of Axial Stress on YBCO Coils

    SciTech Connect

    Sampson, W.; Anerella, M.; Cozzolino, J.P.; Gupta, R.C.; Shiroyanagi, Y.; Evangelou, E.

    2011-03-28

    The large aspect ratio of typical YBCO conductors makes them ideal for constructing solenoids from pancake style coils. An advantage of this method is that each subunit can be tested before assembly into the finished magnet. The fact that conductors are available in relatively short lengths is another reason for using such a fabrication technique. The principal drawback is the large number of joints required to connect the coils together. When very high field solenoids such as those contemplated for the muon collider are built in this way the magnetic forces between pancakes can be very large. Extensive measurements have been made on the effect of stress on short lengths of conductor, but there is little or no data on the effect of intercoil loading. The experiment described in this paper was designed to test the ability of YBCO coils to withstand these forces. A spiral wound 'pancake' coil made from YBCO coated conductor has been stressed to a pressure of 100MPa in the axial direction at 77K. In this case axial refers to the coil so that the force is applied to the edge of the conductor. The effect on the critical current was small and completely reversible. Repeatedly cycling the pressure had no measureable permanent effect on the coil. The small current change observed exhibited a slight hysteretic behaviour during the loading cycle.

  2. Passivation of Flexible YBCO Superconducting Current Lead With Amorphous SiO2 Layer

    NASA Technical Reports Server (NTRS)

    Johannes, Daniel; Webber, Robert

    2013-01-01

    Adiabatic demagnetization refrigerators (ADR) are operated in space to cool detectors of cosmic radiation to a few 10s of mK. A key element of the ADR is a superconducting magnet operating at about 0.3 K that is continually energized and de-energized in synchronism with a thermal switch, such that a piece of paramagnetic salt is alternately warm in a high magnetic field and cold in zero magnetic field. This causes the salt pill or refrigerant to cool, and it is able to suck heat from an object, e.g., the sensor, to be cooled. Current has to be fed into and out of the magnets from a dissipative power supply at the ambient temperature of the spacecraft. The current leads that link the magnets to the power supply inevitably conduct a significant amount of heat into the colder regions of the supporting cryostat, resulting in the need for larger, heavier, and more powerful supporting refrigerators. The aim of this project was to design and construct high-temperature superconductor (HTS) leads from YBCO (yttrium barium copper oxide) composite conductors to reduce the heat load significantly in the temperature regime below the critical temperature of YBCO. The magnet lead does not have to support current in the event that the YBCO ceases to be superconducting. Cus - tomarily, a normal metal conductor in parallel with the YBCO is a necessary part of the lead structure to allow for this upset condition; however, for this application, the normal metal can be dispensed with. Amorphous silicon dioxide is deposited directly onto the surface of YBCO, which resides on a flexible substrate. The silicon dioxide protects the YBCO from chemically reacting with atmospheric water and carbon dioxide, thus preserving the superconducting properties of the YBCO. The customary protective coating for flexible YBCO conductors is silver or a silver/gold alloy, which conducts heat many orders of magnitude better than SiO2 and so limits the use of such a composite conductor for passing current

  3. Development of Modified MOD-TFA Approach for YBCO Film Growth

    SciTech Connect

    Bhuiyan, Md S; Paranthaman, Mariappan Parans; Sathyamurthy, Srivatsan; Hunt, Rodney Dale; List III, Frederick Alyious; Duckworth, Robert C

    2007-01-01

    Low-cost coated-conductor fabrication methods are essential for various electric-power applications. Metal-organic-deposition (MOD) approach to grow both YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) and buffer layers on textured metal substrates is very promising towards fabrication of lower-cost second generation wires. YBCO coated conductors (CC) are being developed with high critical currents that should be sufficient for their extensive use in power applications. However, the present CC has high energy losses in ac magnetic field that are unacceptable. We have developed a modified MOD precursor route to deposit {approx} 0.8 {micro}m thick YBCO films in a single coat that requires less than one-fifth of the pyrolysis time compared to the traditional MOD approach. We have also developed a filamentization technique of CC using ink-jet printing to reduce ac losses due to applied ac fields. The preliminary results of YBCO films deposited on standard RABiTS template yielded an of 140 A/cm at 77 K and self- field. A modest reduction of ac loss was observed for the solution ink-jet printed filamentary conductor.

  4. Cryolubricity of YBCO powder deposits

    NASA Astrophysics Data System (ADS)

    Stevens, Keeley M.; Krim, Jacqueline

    2010-03-01

    Motivated by recent reports of superconductivity-dependent friction [1] in macroscopic pin-on-disk measurements of steel on YBCO, [2] we have investigated the tribological properties of YBCO powder deposits on metal electrodes of a quartz crystal microbalance (QCM). Measurements are performed as a function of temperature over the range 80 - 300K, by monitoring the frequency and amplitude of the QCM both in the presence and absence of adsorbed nitrogen film layers. A pulsed magnetic field was applied to isolate the effect of superconductivity at and around the transition temperature. The powder deposits produce negative shifts in the QCM fundamental frequency, an indication of the strength of their attachment to the surface. The shifts exhibit structure as the temperature passes through the superconducting transition temperature, but the presumed drop in friction is not so large as to produce a decoupling effect which would lead to positive shifts. [3] Measurements on alternate QCM electrodes in the presence of adsorbed film layers are ongoing and will be reported on. Funding provided by NSF DMR. [4pt] [1] Highland, M. and Krim, J. Phys. Rev. Lett. 2006, 96, 226107.[0pt] [2] Ding, Q. et al. Wear 2008, 265, 1136.[0pt] [3] Dybwad, G.L. J. Appl. Phys. 1985, 58, 2789.

  5. Superconducting properties of experimental YBCO coils for FFAG accelerator magnets

    NASA Astrophysics Data System (ADS)

    Takayama, S.; Koyanagi, K.; Tosaka, T.; Tasaki, K.; Kurusu, T.; Ishii, Y.; Amemiya, N.; Ogitsu, T.

    2014-05-01

    A project to develop fundamental technologies for accelerator magnets using high-Tc coated conductors is currently in progress. The primary applications of this project are fixed field alternating gradient (FFAG) accelerators for carbon cancer therapy systems and accelerator-driven subcritical reactors. Several types of superconducting coils for FFAG accelerators have been conceptually designed. These coils have complicated shapes, including a negative-bend part or a three-dimensional bent part. One of the aims of the project is to establish winding technologies for complicated coil shapes using coated conductors. To demonstrate winding technologies for YBa2Cu3O7-x (YBCO) coils, small test coils having a negative-bend part or a three-dimensional bent part were designed and fabricated according to the present design of the FFAG magnet. The outside dimensions of the negative-bend test coil were 460 mm long and 190 mm wide, and the radius of curvature of the negative-bend part was 442 mm. The outside dimensions of the three-dimensional test coil were 380 mm long and 280 mm wide, and the radius of curvature of the mandrel of the three-dimensional coil was 700 mm. The test coils were wound using YBCO coated conductors with a length of about 100 m and were then impregnated with epoxy resin. The coils were placed in liquid nitrogen and excited to measure their V-I characteristics. From the V-I characteristics throughout a voltage range down to 10-9 V/cm, the V-I characteristics before and after impregnation were approximately the same, demonstrating that the superconducting properties were not degraded.

  6. High speed production of YBCO precursor films by advanced TFA-MOD process

    NASA Astrophysics Data System (ADS)

    Ichikawa, H.; Nakaoka, K.; Miura, M.; Sutoh, Y.; Nakanishi, T.; Nakai, A.; Yoshizumi, M.; Izumi, T.; Shiohara, Y.

    2009-10-01

    YBa 2Cu 3O 7-y (YBCO) long tapes derived from the metal-organic deposition (MOD) method using the starting solution containing trifluoroacetate (TFA) have been developed with high critical currents ( I c) over 200 A/cm-width. However, high speed production of YBCO films is simultaneously necessary to satisfy the requirements of electric power device applications in terms of cost and the amounts of the tapes. In this work, we developed a new TFA-MOD starting solution using F-free salt of Y, TFA salt of Ba and Cu-Octylate for application to the coating/calcination process and discussed several issues by using the Multi-turn (MT) Reel-to-Reel (RTR) system calcination furnace for the purpose of high throughput without degradation of the properties. The coating system was improved for uniform deposition qualities in both longitudinal and transversal directions. YBCO films using the new starting solution at the traveling rate of 10 m/h in coating/calcination by the MT-RTR calcination furnace showed the values of the critical current density of 1.6 MA/cm 2 as thick as 1.5 μm at 77 K under the self fields after firing at the high heating rate in the crystallization.

  7. Properties of YBCO on LaMnO3-capped IBAD MgO-templates without Homo-epitaxial MgO layer.

    SciTech Connect

    Aytug, Tolga; Paranthaman, Mariappan Parans; Kim, Kyunghoon; Zhang, Yifei; Cantoni, Claudia; Zuev, Yuri L; Goyal, Amit; Thompson, James R; Christen, David K

    2009-01-01

    Previously, it has been well established that in an IBAD architecture for coated conductors, (1) LaMnO3 (LMO) buffer layers are structurally and chemically compatible with an underlying homo-epitaxial MgO layer and (2) high current density YBCO films can be grown on these LMO templates. In the present work, the homo-epi MgO layer has been successfully eliminated and a LMO cap layer was grown directly on the IBAD (MgO) template. The performance of the LMO/IBAD (MgO) samples has been qualified by depositing 1 m-thick YBCO coatings by pulsed laser deposition. Electrical transport measurements of YBCO films on the standard (with homo-epi MgO) and simplified (without homo-epi MgO) IBAD architectures were carried out. The angular dependencies of critical current density (Jc) are similar for both IBAD architectures. XRD measurements indicate good, c-axis aligned YBCO films. Transmission electron microscopy (TEM) images reveal that microstructures of YBCO/LMO/IBAD (MgO) and YBCO/LMO/homo-epi MgO/IBAD (MgO) templates are similar. These results demonstrate the strong potential of using LMO as a single cap layer directly on IBAD (MgO) for the development of a simplified IBAD architecture.

  8. Microstructural analysis on growth and crystallization mechanism of YBCO films deposited by advanced TFA-MOD process

    NASA Astrophysics Data System (ADS)

    Matsuda, J.; Nakaoka, K.; Sutoh, Y.; Nakanishi, T.; Yoshizumi, M.; Yamada, Y.; Izumi, T.; Shiohara, Y.

    2007-10-01

    We have investigated effects of the heating rate in the crystallization process on Ic values and microstructures of YBa2Cu3O7-δ (YBCO) films, which were fabricated by the advanced metalorganic deposition (MOD) method using trifluoroacetates. As a result, it was found that the slow heating rate less than 2 °C/min in the crystallization process increases the volume of randomly oriented YBCO crystals, which results in a low Ic value of the YBCO film. TEM observations of quenched samples prepared by cooling rapidly during the crystallization process revealed that unreacted phase particles such as CuO, Y2Cu2O5 and Ba-O-F crystallize and coarsen to large crystals before the nucleation and growth of YBCO crystals in the case of slow heating. We conclude that it is important to control the size and distributions of the unreacted phase particles in the crystallization process, in order to fabricate the YBCO coated conductor with high Ic.

  9. Coated conductor scale-up program at IGC-SuperPower

    NASA Astrophysics Data System (ADS)

    Selvamanickam, V.; Li, Y.; Sathiaraju, S.; Qiao, Y.; Zdun, K.; Hope, L.; Reeves, J.; Lenseth, K.; Haldar, P.

    2002-01-01

    The objective of the coated conductor program at IGC-SuperPower is to scale up substrate, buffer, and YBCO deposition process to manufacturing. Recently, pilot-scale manufacturing facilities were established for substrate, buffer, and YBCO preparation at IGC-SuperPower. High-quality substrate, buffer, and Y-Ba-Cu-O (YBCO) tapes are being produced in the pilot-scale facilities. .

  10. Growth and superconducting properties of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} films on conductive SrRuO{sub 3} and LaNiO{sub 3} multilayers for coated conductor applications

    SciTech Connect

    Aytug, T.; Wu, J. Z.; Cantoni, C.; Verebelyi, D. T.; Specht, E. D.; Paranthaman, M.; Norton, D. P.; Christen, D. K.; Ericson, R. E.; Thomas, C. L.

    2000-02-07

    Conductive multilayers of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}/SrRuO{sub 3}/LaNiO{sub 3} (YBCO/SRO/LNO), YBCO/SRO, and YBCO/LNO were grown epitaxially on single-crystal LaAlO{sub 3} and SrTiO{sub 3} substrates. Property characterizations revealed that the YBCO films on SRO and SRO/LNO buffer structures have excellent structural and superconducting properties. The YBCO/LNO, however, suffers degradation in superconducting transition temperatures and critical current densities, despite a good crystalline structure. The SRO/LNO bilayer showed excellent electrical contact with YBCO. These results have demonstrated the structural and chemical compatibility of SRO/LNO multilayers with YBCO and their potential use as conductive buffer layers for YBCO-based coated conductors as well as for other high-temperature superconducting applications. (c) 2000 American Institute of Physics.

  11. Epitaxial growth of biaxially oriented YBCO films on silver

    NASA Astrophysics Data System (ADS)

    Liu, Danmin; Zhou, Meiling; Wang, Xue; Suo, Hongli; Zuo, Tieyong; Schindl, Michael; Flükiger, René

    2001-09-01

    YBCO films were deposited on (100), (110) and (111) oriented silver single crystals and { 100} <100>, { 110} <211> and { 012} <100> biaxially textured Ag substrates by pulsed laser deposition. It is shown that the (100) and (110) orientated single crystals and the { 110} biaxially textured Ag tape are all suitable for the deposition of YBCO thin films with c-axis in-plane alignment. The Jc of YBCO film deposited on { 110} <211> biaxially textured Ag foil is 7×105A cm-2 at 77 K, 0 T. A scheme for the regular growth of YBCO on silver was put forward.

  12. Coatings.

    ERIC Educational Resources Information Center

    Anderson, Dennis G.

    1989-01-01

    This review covers analytical techniques applicable to the examination of coatings, raw materials, and substrates upon which coatings are placed. Techniques include chemical and electrochemical methods, chromatography, spectroscopy, thermal analysis, microscopy, and miscellaneous techniques. (MVL)

  13. EDITORIAL: Coated conductors and their applications Coated conductors and their applications

    NASA Astrophysics Data System (ADS)

    Freyhardt, Herbert C.; Lee, Dominic; Izumi, Teruo

    2010-01-01

    The attractive perspectives offered by coated conductors, known as the 2nd generation of high temperature superconductors (2G-HTS), have triggered broad and fruitful R&D efforts to make them ready for the marketplace. The anisotropic features of YBCO and its weak-link behavior require the processing of almost single crystalline thin films into flat tapes of coated conductors by basically two different methods: RABiTS—rolling-assisted biaxially textured substrates; and IBAD—ion-beam assisted deposition. Reliable processing technologies are now at hand, and critical current carrying capacities can be raised to almost 10-20% of the theoretically possible limit by optimizing current transfer through grain boundaries as well as flux pinning through control and design of the microstructural landscapes. The optimization of the in-field properties of the 2G-HTS wires, as well as the manufacturing of coated conductors with low ac losses and of assembled conductors for high current application remain active development areas. Cost reduction and more economic processing are still an issue. However, coated conductors are now beginning to penetrate the market, particularly for power and electrical applications, where savings in energy are essential and where the unique features of high temperature superconducting materials can be utilized. Major international conferences have followed up the progress in this exciting realm, and important workshops and discussion meetings have been held on this topic. Nonetheless, it was felt that a concise and up-to-date issue of Superconductor Science and Technology would be most welcome to summarize and collect the latest developments in processing and characterizing coated conductors, as well as drawing attention to the most innovative applications. The Guest Editors of this focus issue owe great thanks to those colleagues who were willing to contribute with their most recent findings to this issue on 'Coated conductors and their

  14. Study of the Nucleation and Growth of YBCO on Oxide Buffered Metallic Tapes

    SciTech Connect

    Solovyov, Vyacheslav

    2009-04-10

    The CRADA collaboration concentrated on developing the scientific understanding of the factors necessary for commercialization of high temperature superconductors (HTS) based on the YBCO coated conductor technology for electric power applications. The project pursued the following objectives: 1. Establish the correlations between the YBCO nuclei density and the properties of the CeO{sub 2} layer of the RABiTS{trademark} template; 2. Compare the nucleation and growth of e-beam and MOD based precursors on the buffered RABiTS{trademark} templates and clarify the materials science behind the difference; and 3. Explore routes for the optimization of the nucleation and growth of thick film MOD precursors in order to achieve high critical current densities in thick films. The CRADA work proceeded in two steps: 1. Detailed characterization of epitaxial ceria layers on “model” substrates, such as (001) YSZ and on RABiTS tapes; and 2. Study of YBCO nucleation on well-defined substrates and on long-length RABiTS.

  15. Low Cost Fabrication of 2G Wires for AC Applications

    SciTech Connect

    Kodenkandath, T.; List, F.A., III

    2005-09-15

    Ink-jet printing has been demonstrated as an adaptable technology for printing YBCO filaments using a Metal Organic (MO) YBCO precursor. The technology was demonstrated using AMSC's proprietary metal organic TFA-based YBCO precursor and a commercial piezoelectric print-head on RABiTS templates. Filaments with a width of 100 um and spacing of 200 um were successfully printed, decomposed and processed to YBCO. Critical currents of {approx} 200 A/cm-w were achieved in a series of filaments with a 2 mm width. The single nozzle laboratory printer used in the Phase 1 program is capable of printing {approx} 100 um wide single filaments at a rate of 8-10 cm/sec. The electrical stabilization of filaments with a Ag ink was also evaluated using ink-jet printing. The overall objective of the Phase 1 Project was the evaluation and demonstration of inkjet-printing for depositing YBCO filaments on textured templates (RABiTS, IBAD, ISD, etc. substrates) with properties appropriate for low loss ac conductors. Goals of the Phase 1 program included development of an appropriate precursor ink, demonstration of the printing process, processing and characterization of printed YBCO filaments and evaluation of the process for further development.

  16. Fast infrared response of YBCO thin films

    NASA Technical Reports Server (NTRS)

    Ballentine, P. H.; Kadin, A. M.; Donaldson, W. R.; Scofield, J. H.; Bajuk, L.

    1990-01-01

    The response to short infrared pulses of some epitaxial YBCO films prepared by sputter deposition and by electron-beam evaporation is reported. The response is found to be essentially bolometric on the ns timescale, with some indirect hints of nonequilibrium electron transport on the ps scale. Fast switching could be obtained either by biasing the switch close to the critical current or by cooling the film below about 20 K. These results are encouraging for potential application to a high-current optically-triggered opening switch.

  17. Manufacture of YBCO Superconducting Flexible Tapes from Nanoparticle Films Derived from Sedimentation and by Flame Deposition of Nanoparticles from Solution

    SciTech Connect

    Wiesmann, Harold

    2008-02-24

    The objective of this CRADA was to develop the experimental and theoretical basis of a technology to produce yttrium barium copper oxide (YBCO) superconducting flexible tapes derived from nanoparticle metal oxide sols. The CRADA was a joint effort between Oxford Superconducting Technology, Brookhaven National Laboratory and Karpov Institute of Physical Chemistry. The effort was divided into three main tasks, the synthesis of a heteroepitaxial oxide buffer layer, and the manufacture of a flexible biaxially textured metallic substrate and the synthesis of a heteroepitaxial crystalline YBCO layer. The formation of a heteroepitaxial buffer layer was implemented using technology developed at the Karpov Institute of Physical Chemistry for the synthesis, stabilization and deposition of polymer stabilized nanoparticle metal oxide sols. Using this technology, flexible oriented RABiTS nickel tapes, manufactured and supplied by the CRADA partner, Oxford Superconducting Technology, Carteret, New Jersey, were coated with a film of metal oxide nanoparticles. After coating the RABiTS nickel tapes with the nanoparticle sols the nickel tape/nanoparticle composite structure was sintered in order to form a dense crystalline heteroepitaxial oxide layer on the surface of the tape, also known as a ‘buffer’ layer. The final phase of the research was the formation of a heteroepitaxial YBCO layer, grown on top of the metal oxide buffer layer. This work was scheduled to follow the development of the heteroepitaxial oxide buffer layer as described above. Three different polymer stabilized sols, yttrium hydroxide, Y(OH){sub 3}, copper hydroxide, Cu(OH){sub 2}, and barium fluoride, BaF{sub 2}, were synthesized and combined in the appropriate stoichiometric ratio. This metal oxide sol was then be deposited onto the buffer layer and reacted to form a crystalline heteroepitaxial YBCO film ranging from 1–5 microns thick.

  18. CHEMICAL SOLUTION DEPOSITION BASED OXIDE BUFFERS AND YBCO COATED CONDUCTORS

    SciTech Connect

    Paranthaman, Mariappan Parans

    2011-01-01

    We have reviewed briefly the growth of buffer and high temperature superconducting oxide thin films using a chemical solution deposition (CSD) method. In the Rolling-Assisted Biaxially Textured Substrates (RABiTS) process, developed at Oak Ridge National Laboratory, utilizes the thermo mechanical processing to obtain the flexible, biaxially oriented copper, nickel or nickel-alloy substrates. Buffers and Rare Earth Barium Copper Oxide (REBCO) superconductors have been deposited epitaxially on the textured nickel alloy substrates. The starting substrate serves as a template for the REBCO layer, which has substantially fewer weak links. Buffer layers play a major role in fabricating the second generation REBCO wire technology. The main purpose of the buffer layers is to provide a smooth, continuous and chemically inert surface for the growth of the REBCO film, while transferring the texture from the substrate to the superconductor layer. To achieve this, the buffer layers need to be epitaxial to the substrate, i.e. they have to nucleate and grow in the same bi-axial texture provided by the textured metal foil. The most commonly used RABiTS multi-layer architectures consist of a starting template of biaxially textured Ni-5 at.% W (Ni-W) substrate with a seed (first) layer of Yttrium Oxide (Y2O3), a barrier (second) layer of Yttria Stabilized Zirconia (YSZ), and a Cerium Oxide (CeO2) cap (third) layer. These three buffer layers are generally deposited using physical vapor deposition (PVD) techniques such as reactive sputtering. On top of the PVD template, REBCO film is then grown by a chemical solution deposition. This article reviews in detail about the list of oxide buffers and superconductor REBCO films grown epitaxially on single crystal and/or biaxially textured Ni-W substrates using a CSD method.

  19. Obtention and characterization of YBCO/Ag/YBCO welds at different misorientation angles

    NASA Astrophysics Data System (ADS)

    Bozzo, B.; Bartolomé, E.; Granados, X.; Puig, T.; Obradors, X.

    2006-06-01

    The microstructural and magnetic properties of YBa2Cu3O7 (YBCO) welds with different crystallographic [001]-tilt misorientation, prepared by the Ag surface melting induced welding technique, have been studied. The inter- and intra-grain critical current densities have been simultaneously obtained by solving the Inverse Problem from the remanent local magnetization magnetic field maps measured by Hall Probe imaging. The obtained dependence of the inter-grain current density with the angle, JcGB(θ), is compared to previous results for thin-film bicrystals and bulk boundaries.

  20. Engineered pinning landscapes for enhanced 2G coil wire

    DOE PAGES

    Rupich, Martin W.; Sathyamurthy, Srivatsan; Fleshler, Steven; Li, Qiang; Solovyov, Vyacheslav; Ozaki, Toshinori; Welp, Ulrich; Kwok, Wai -Kwong; Leroux, Maxime; Koshelev, Alexei E.; et al

    2016-04-01

    We demonstrate a twofold increase in the in-field critical current of AMSC's standard 2G coil wire by irradiation with 18-MeV Au ions. The optimum pinning enhancement is achieved with a dose of 6 × 1011 Au ions/cm2. Although the 77 K, self-field critical current is reduced by about 35%, the in-field critical current (H//c) shows a significant enhancement between 4 and 50 K in fields > 1 T. The process was used for the roll-to-roll irradiation of AMSC's standard 46-mm-wide production coated conductor strips, which were further processed into standard copper laminated coil wire. The long-length wires show the samemore » enhancement as attained with short static irradiated samples. The roll-to-roll irradiation process can be incorporated in the standard 2G wire manufacturing, with no modifications to the current process. In conclusion, the enhanced performance of the wire will benefit rotating machine and magnet applications.« less

  1. AC and DC transport currents in melt-grown YBCO

    SciTech Connect

    Yi, Z.; Ashworth, S.; Becluz, C.; Scurlock, R.G. )

    1991-03-01

    It has been suggested that the transport J{sub c} in multi-grain samples of bulk YBCO are limited by the intergrain links. This paper reports on preliminary measurements of intergrain currents. The intergrain critical currents in melt grown YBCO do not appear to be as sensitive to the precise crystallographic alignment of adjacent grains a has been reported for thin films. The measured critical current of similar grain boundaries varies widely, between 15000 A/cm{sup 2} and 200A/Cm{sub 2} for adjacent boundaries in the same sample.

  2. Critical currents of YBCO tapes and Bi-2212 wires at different temperatures and magnetic fields

    SciTech Connect

    Lombardo, V.; Barzi, e.; Turrioni, D.; Zlobin, A.V.; /Fermilab

    2010-08-01

    Design studies for the cooling channel of a Muon Collider call for straight and helical solenoids generating field well in excess of the critical fields of state of the art Low Temperature Superconductors (LTS) such as Nb{sub 3}Sn or NbTi. Therefore, High Temperature Superconductors (HTS) will need to be used for the manufacturing of all or certain sections of such magnets to be able to generate and withstand the field levels at the cryogenic temperatures required by the new machine. In this work, two major High Temperature Superconductors - Bi2212 round wires and YBCO coated conductor tapes - are investigated to understand how critical current density of such conductors scales as a function of external field and operating temperature. This is vital information to make conductor choices depending on the application and to proceed with the design of such magnets.

  3. Effect of copper content in precursor solution on the superconducting properties of YBCO films derived from low-fluorine solution

    NASA Astrophysics Data System (ADS)

    Zhao, Gaoyang; Lei, Li; Liu, Xiaomei; Chen, Yuanqing

    2008-12-01

    Four low-fluorine solutions with different stoichiometry of Y:Ba:Cu = 1:2: ξ ( ξ = 3, 3.5, 4, 4.5) were prepared using Ba-TFA, yttrium and copper acetate as precursors. YBa 2Cu 3O 7-δ (YBCO) films derived from these low-fluorine solutions were coated on LaAlO 3 (LAO) single crystal substrates by dip-coating process. The effect of copper stoichiometry in precursor solution on the microstructure and superconductivity of YBCO films was studied. The growth orientation and microstructure of the films were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The results show that there are large volume fraction of a-axis oriented YBCO grains in the films derived from precursor solutions with stoichiometry of Y:Ba:Cu = 1:2: ξ ( ξ = 3, 3.5, 4.5), while the films from the solution with stoichiometry of Y:Ba:Cu = 1:2:4 mainly grow along c-axis orientation and the volume fraction of c-axis oriented grains is 96.33%. Superconductivity test indicate that the film derived from the precursor solution with stoichiometry of Y:Ba:Cu = 1:2:4 exhibits excellent superconducting properties with the critical transition temperature Tc approximate 90 K, the sharp transition temperature Δ T below 1 K and the critical current density Jc over 1 MA/cm 2 (77 K, 0 T).

  4. High Tc YBCO superconductor deposited on biaxially textured Ni substrate

    DOEpatents

    Budai, John D.; Christen, David K.; Goyal, Amit; He, Qing; Kroeger, Donald M.; Lee, Dominic F.; List, III, Frederick A.; Norton, David P.; Paranthaman, Mariappan; Sales, Brian C.; Specht, Eliot D.

    1999-01-01

    A superconducting article includes a biaxially-textured Ni substrate, and epitaxial buffer layers of Pd (optional), CeO.sub.2 and YSZ, and a top layer of in-plane aligned, c-axis oriented YBCO having a critical current density (J.sub.c) in the range of at least 100,000 A/cm.sup.2 at 77 K.

  5. Superconductivity of YBCO Thick Films Prepared by Spark Plasma Sintering

    NASA Astrophysics Data System (ADS)

    Kim, Youngha; Lee, Kyong H.; Sung, Tae-Hyun; Han, Sang-Chul; Han, Young-Hee; Jeong, Nyeon-Ho; No, Kwangsoo

    2007-10-01

    YBa2Cu3O x (YBCO) superconducting thick films have been fabricated on Cu substrates, using a simple screen-printing method from Cu-free powders (Y2O3 and BaCO3). However, such films have poor superconducting properties such as critical current density ( J c) due to the low film density. In this work, we investigate the effect of uniaxial c-axis pressure on the superconducting properties of these YBCO films using a spark plasma sintering (SPS) technique. The film screen-printed on Cu substrates was heat-treated at 850°C for 5 min in vacuum varying the pressure (15, 30, and 45 MPa). To form a superconducting YBCO phase, the film was reheat-treated at 930°C for 30 s in air followed by oxygen annealing at 450°C for 1 h. For heat-treatments performed under pressure, lower film porosity was obtained, and a higher crack density was also observed compared to films prepared without pressure. The densification of the YBCO thick films using the SPS technique was very effective in improving the superconducting properties of the films.

  6. Pulsed laser deposition of YBCO thin films on IBAD-YSZ substrates

    NASA Astrophysics Data System (ADS)

    Li, M.; Ma, B.; Koritala, R. E.; Fisher, B. L.; Venkataraman, K.; Balachandran, U.

    2003-01-01

    High-quality YBa2Cu3O7-x (YBCO) films were fabricated on yttria-stabilized zirconia (YSZ)-buffered Hastelloy C276 substrates by pulsed laser deposition. YSZ was grown by ion-beam-assisted deposition. A thin (approx10 nm) CeO2 layer was deposited before the deposition of YBCO. The crystalline structure and biaxial texture of the YBCO film and the buffer layer were examined by x-ray diffraction 2theta-scan, phi-scan and pole-figure analysis. Epitaxial growth of the YBCO film on the buffer layer was observed. Full width at half maximum (FWHM) value of 7.4° was measured from the phi-scan of YBCO(103). Raman spectroscopy showed compositional uniformity and phase integrity in the YBCO films. Surface morphologies of the YBCO films were examined by scanning electron microscopy. Comparative studies indicated that the CeO2 buffer layer significantly improves the structural alignment and superconducting properties of YBCO films. Tc = 90 K, with sharp transition, and transport Jc = 2.2 × 106 A cm-2 at 77 K in zero-external field were obtained on the 0.5 mum thick YBCO films. The dependence of Jc on the FWHM of the YBCO(103) phi-scan indicated that high Jc is associated with low FWHM.

  7. Coated Conductors for the Magnetic Bearing Application

    NASA Astrophysics Data System (ADS)

    Sass, Felipe; Dias, Daniel Henrique Nogueira; Sotelo, Guilherme Gonçalves; Júnior, Rubens de Andrade

    The second generation (2G) of superconductor wires have been considered for several applications lately. This work presents a preliminary study of superconducting magnetic bearings (SMB) using 2G wires as passive levitators. A superconducting block using stacked 2G wires was built to evaluate the magnetic bearing behavior, thought levitation force measurements, when a permanent magnet cylinder approaches or moves away from the block. The superconducting block was compared with an YBCO bulk with nearly the same dimensions and the results show a promising potential for this application.

  8. STANFORD IN-SITU HIGH RATE YBCO PROCESS: TRANSFER TO METAL TAPES AND PROCESS SCALE UP

    SciTech Connect

    Malcolm R. Beasley; Robert H.Hammond

    2009-04-14

    Executive Summary The materials science understanding of high rate low cost processes for Coated Conductor will benefit the application to power utilities for low loss energy transportation and power generation as well for DOD applications. The research in this program investigated several materials processing approaches that are new and original, and are not being investigated elsewhere. This work added to the understanding of the material science of high rate PVD growth of HTSC YBCO assisted by a liquid phase. A new process discovered uses amorphous glassy precursors which can be made at high rate under flexible conditions of temperature and oxygen, and later brought to conditions of oxygen partial pressure and temperature for rapid conversion to YBCO superconductor. Good critical current densities were found, but further effort is needed to optimize the vortex pinning using known artificial inclusions. A new discovery of the physics and materials science of vortex pinning in the HTSC system using Sm in place of Y came at growth at unusually low oxygen pressure resulting in clusters of a low or non superconducting phase within the nominal high temperature phase. The driving force for this during growth is new physics, perhaps due to the low oxygen. This has the potential for high current in large magnetic fields at low cost, applicable to motors, generators and transformers. The technical demands of this project were the motivation for the development of instrumentation that could be essential to eventual process scale up. These include atomic absorption based on tunable diode lasers for remote monitoring and control of evaporation sources (developed under DARPA support), and the utility of Fourier Transform Infrared Reflectivity (FTIR) for aid in the synthesis of complex thin film materials (purchased by a DURIP-AFOSR grant).

  9. BaHfO3 artificial pinning centres in TFA-MOD-derived YBCO and GdBCO thin films

    NASA Astrophysics Data System (ADS)

    Erbe, M.; Hänisch, J.; Hühne, R.; Freudenberg, T.; Kirchner, A.; Molina-Luna, L.; Damm, C.; Van Tendeloo, G.; Kaskel, S.; Schultz, L.; Holzapfel, B.

    2015-11-01

    Chemical solution deposition (CSD) is a promising way to realize REBa2Cu3O7-x (REBCO; RE = rare earth (here Y, Gd))-coated conductors with high performance in applied magnetic fields. However, the preparation process contains numerous parameters which need to be tuned to achieve high-quality films. Therefore, we investigated the growth of REBCO thin films containing nanometre-scale BaHfO3 (BHO) particles as pinning centres for magnetic flux lines, with emphasis on the influence of crystallization temperature and substrate on the microstructure and superconductivity. Conductivity, microscopy and x-ray investigations show an enhanced performance of BHO nano-composites in comparison to pristine REBCO. Further, those measurements reveal the superiority of GdBCO to YBCO—e.g. by inductive critical current densities, J c, at self-field and 77 K. YBCO is outperformed by more than 1 MA cm-2 with J c values of up to 5.0 MA cm-2 for 265 nm thick layers of GdBCO(BHO) on lanthanum aluminate. Transport in-field J c measurements demonstrate high pinning force maxima of around 4 GN m-3 for YBCO(BHO) and GdBCO(BHO). However, the irreversibility fields are appreciably higher for GdBCO. The critical temperature was not significantly reduced upon BHO addition to both YBCO and GdBCO, indicating a low tendency for Hf diffusion into the REBCO matrix. Angular-dependent J c measurements show a reduction of the anisotropy in the same order of magnitude for both REBCO compounds. Theoretical models suggest that more than one sort of pinning centre is active in all CSD films.

  10. Doping Effect of Nano-Ybco Additive on MgB2

    NASA Astrophysics Data System (ADS)

    Rui, X. F.; Sun, X. F.; Xu, X. L.; Zhang, L.; Zhang, H.

    The effect of YBCO nanoparticles added into MgB2 on Tc, Jc, and flux pinning was studied for MgB2(YBCO)x with x=0, 5, 10, 15 wt%. Phase analysis shows that none of elements are doped into the MgB2 lattice in the samples with YBCO addition. For the samples with YBCO addition, the Jc-H characteristics behave poorly in comparison with the pure sample. Our experimental results show that the nanoscale size of addition dosen't comprise the only condition for its effectiveness as pinning centers.

  11. Influence of oxygen partial pressure and silver additions on microstructure and related properties of YBCO superconductors

    SciTech Connect

    Singh, J.P.; Joo, J.; Guttschow, R.; Poeppel, R.B.

    1992-02-01

    Microstructure has a great influence on the mechanical and superconducting properties of YBCO. Mechanical properties of YBCO can be improved by both modifying the monolithic microstructure and developing composites of YBCO with silver (Ag). When monolithic YBCO was sintered to high densities ({approx} 91%) at a relatively low temperature ({approx} 910{degrees}C) by controlling oxygen partial pressure during sintering, the result was a small-grain microstructure (average grain size {approx} 5 {mu}m) and hence a high strength of 191 {plus_minus} 7 MPa. Addition of Ag as a second phase further improved the strength of YBCO. Composites of YBCO with 10 to 15 vol % Ag has a strength of 225 {plus_minus} 6 MPa and a fracture toughness of 3.3 {plus_minus} 0.2 MPa{radical}m. These improvements are believed to be due to compressive stresses in the YBCO matrix as a result of thermal mismatch between the YBCO and Ag phases. Furthermore, the Ag particles may provide increased resistance to crack propagation by pinning the crack. On the other hand, addition of Ag as a dopant to substitute for Cu sites in YBCO has a profound but nonmonotonic effect on grain microstructure and the resulting critical current density.

  12. Influence of oxygen partial pressure and silver additions on microstructure and related properties of YBCO superconductors

    SciTech Connect

    Singh, J.P.; Joo, J.; Guttschow, R.; Poeppel, R.B.

    1992-02-01

    Microstructure has a great influence on the mechanical and superconducting properties of YBCO. Mechanical properties of YBCO can be improved by both modifying the monolithic microstructure and developing composites of YBCO with silver (Ag). When monolithic YBCO was sintered to high densities ({approx} 91%) at a relatively low temperature ({approx} 910{degrees}C) by controlling oxygen partial pressure during sintering, the result was a small-grain microstructure (average grain size {approx} 5 {mu}m) and hence a high strength of 191 {plus minus} 7 MPa. Addition of Ag as a second phase further improved the strength of YBCO. Composites of YBCO with 10 to 15 vol % Ag has a strength of 225 {plus minus} 6 MPa and a fracture toughness of 3.3 {plus minus} 0.2 MPa{radical}m. These improvements are believed to be due to compressive stresses in the YBCO matrix as a result of thermal mismatch between the YBCO and Ag phases. Furthermore, the Ag particles may provide increased resistance to crack propagation by pinning the crack. On the other hand, addition of Ag as a dopant to substitute for Cu sites in YBCO has a profound but nonmonotonic effect on grain microstructure and the resulting critical current density.

  13. Unique magnetic structure of YbCo2Si2

    NASA Astrophysics Data System (ADS)

    Mufti, N.; Kaneko, K.; Hoser, A.; Gutmann, M.; Geibel, C.; Krellner, C.; Stockert, O.

    2016-07-01

    We report on the results of powder and single-crystal neutron diffraction to investigate the magnetic order in YbCo2Si2 below the Néel temperature TN=1.7 K in detail. Two different magnetically ordered phases can clearly be distinguished. At lowest temperatures a commensurate magnetic structure with a propagation vector k1=(0.25 0.25 1 ) is found, while the intermediate phase (T >0.9 K) is characterized by an incommensurate magnetic structure with k2=(0.25 0.086 1 ) . The magnetic structure in YbCo2Si2 is in marked contrast to all other known R Co2Si2 compounds (R = rare earth element) likely due to some itineracy of the Yb 4 f states being responsible for the magnetism.

  14. High frequency properties of YBCO bridges fabricated by MOCVD

    SciTech Connect

    Chen, J.; Yamoshita, T. ); Suzuki, H.; Kurosawa, H. ); Yamane, H.; Hirai, T. . Inst. for Materials Research)

    1991-03-01

    This paper reports on the high frequency properties of YBCO bridges at 4.2% and 77K. The YBCO films were prepared by MOCVD. For small bridges with the width(w) of about 1 {mu}m and thickness(t) of less than 0.5{mu}m, the constant voltage steps at integral multiples of {phi}{sub 0}fr = 20 {mu}V were observed up to 1 mV, which is much higher than the IcR{sub N} ({lt}0.13 mV) product of these bridges at 77K. The magnitudes of the current steps as functions of the rf current at 4.2K and 77K were in quantitative agreement with the theoretical results based on the RSJ model.

  15. Temperature dependence of nanoscale friction for Fe on YBCO

    NASA Astrophysics Data System (ADS)

    Altfeder, Igor; Krim, Jacqueline

    2012-05-01

    A magnetic probe microscopy study of levitation and atomic-scale friction is reported for Fe on YBCO (Tc = 92.5 K) in the temperature range 65-293 K. Below Tc, the friction coefficient is constant and exhibits no correlation with the strength of superconducting levitation forces. Above Tc, the friction coefficient increases progressively, and nearly doubles between Tc and room temperature. The results are discussed within the context of the underlying atomic-scale electronic and phononic mechanisms that give rise to friction, and it is concluded that contact electrification and static electricity may play a significant role in the non-superconducting phase. Given that the properties of YBCO can be finely tuned, the results point the way to a variety of interesting studies of friction and superconductors.

  16. Zone refining of sintered, microwave-derived YBCO superconductors

    SciTech Connect

    Warrier, K.G.K.; Varma, H.K.; Mani, T.V.; Damodaran, A.D.; Balachandran, U.

    1993-07-01

    Post-sintering treatments such as zone melting under thermal gradient has been conducted on sintered YBCO tape cast films. YBCO precursor powder was derived through decomposition of a mixture of nitrates of cations in a microwave oven for {approx}4 min. The resulting powder was characterized and made into thin sheets by tape casting and then sintered at 945 C for 5 h. The sintered tapes were subjected to repeated zone refining operations at relatively high speeds of {approx}30 mm/h. A microstructure having uniformly oriented grains in the a-b plane throughout the bulk of the sample was obtained by three repeated zone refining operations. Details of precursor preparation, microwave processing and its advantages, zone refining conditions, and microstructural features are presented in this paper.

  17. Vortex creep in TFA-YBCO nanocomposite films

    NASA Astrophysics Data System (ADS)

    Rouco, V.; Bartolomé, E.; Maiorov, B.; Palau, A.; Civale, L.; Obradors, X.; Puig, T.

    2014-11-01

    Vortex creep in YBa2Cu3O7 - x (YBCO) films grown from the trifluoracetate (TFA) chemical route with BaZrO3 and Ba2YTaO6 second-phase nanoparticles (NPs) has been investigated by magnetic relaxation measurements. We observe that in YBCO nanocomposites the phenomenological crossover line from the elastic to the plastic creep regime is shifted to higher magnetic fields and temperatures. The origin of this shift lies on the new isotropic-strong vortex pinning contribution appearing in these nanocomposites, induced by local lattice distortions. As a consequence, we demonstrate that the addition of non-coherent NPs produces a decrease in the creep rate S in most of the phase diagram, particularly, in the range of fields and temperatures (T\\gt 60 K, {{μ }0}H\\gt 0.5 T) relevant for large scale applications.

  18. Current Distribution in Wide YBCO Tapes

    NASA Astrophysics Data System (ADS)

    Carrera, M.; Granados, X.; Amorós, J.; Puig, T.; Obradors, X.

    The need of a better mechanical behaviour and the stabilization of coated conductors for applications, as Magnets, cables or Fault Current Limiters, has motivated the lamination of tapes with stainless steel or copper alloys, increasing so the elastic modulus of the conductors and their mechanical performance. Some of the stainless steels used are magnetic, thus introducing some perturbations of the current flow when energizing the conductor. In order to detect these possible perturbations, the magnetic self field in the surface of the tape has been explored by Hall mapping technique at several current loads in a monotonically driven cyclic sequence. By increasing current steps when loading up, crossing the critical field threshold, and decreasing down to remanent state. Deviation from the expected magnetic map has been observed. In this work, we will report on the resulting measurements, and the current flow is calculated by solving the inverse problem for a 12 mm wide stainless steel reinforced Coated Conductor tape. We discuss on the likely origin of the observed perturbations.

  19. A 5.9 tesla conduction-cooled coil composed of a stack of four single pancakes wound with YBCO wide tapes

    NASA Astrophysics Data System (ADS)

    Iwai, Sadanori; Miyazaki, Hiroshi; Tosaka, Taizo; Tasaki, Kenji; Urata, Masami; Ioka, Shigeru; Ishii, Yusuke

    2013-11-01

    We have been developing a conduction-cooled coil wound with YBCO-coated conductors for HTS applications. Previously, we have fabricated a coil composed of a stack of 12 single pancakes wound with 4 mm-wide YBCO tapes. This coil had a central magnetic field as high as 5.1 T at 10 K under conduction-cooled conditions. In the present study, we fabricated and tested a coil composed of a stack of four single pancakes wound with 12 mm-wide YBCO tapes. The total size of the coil and the Jc value of the tapes were almost the same as those of the former coil. At 77 K, the voltage-current characteristics showed a high n-value of 24, confirming that the coil had no degradation. Furthermore, in a conduction-cooled configuration at 20 K to 60 K, the coil showed a high n-value of over 20. At 20 K, the central magnetic field reached 5.9 T at 903 A, which is 1.3-times higher than that of the former coil.

  20. Thickness-Dependent Properties of YBCO Films Grown on GZO/CLO-Buffered NiW Substrates

    NASA Astrophysics Data System (ADS)

    Malmivirta, M.; Huhtinen, H.; Zhao, Y.; Grivel, J.-C.; Paturi, P.

    2016-07-01

    To study the role of novel Gd_2 Zr_2 O_7 /Ce_{0.9} La_{0.1} O_2 buffer layer structure on a biaxially textured NiW substrate, a set of YBa_2 Cu_3 O_{7-δ } (YBCO) films with different thicknesses were prepared by pulsed laser deposition (PLD). Interface imperfections as well as thickness-dependent structural properties were observed in the YBCO thin films. The structure is also reflected into the improved superconducting properties with the highest critical current densities in films with intermediate thicknesses. Therefore, it can be concluded that the existing buffer layers need more optimization before they can be successfully used for films with various thicknesses. This issue is linked to the extremely susceptible growth method of PLD when compared to the commonly used chemical deposition methods. Nevertheless, PLD-grown films can give a hint on what to concentrate to be able to further improve the buffer layer structures for future coated conductor technologies.

  1. Interactions of Y2BaCuO5 particles and the YBCO matrix within melt-textured YBCO samples studied by means of electron backscatter diffraction

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Mücklich, F.; Ogasawara, K.; Murakami, M.

    2005-02-01

    By means of automated electron backscatter diffraction (EBSD) analysis, we studied the local orientations of embedded Y2BaCuO5(211) particles within melt-textured YBa2Cu3Ox (YBCO) samples. On both components, we obtained high-quality Kikuchi patterns, thus allowing the automated mapping of the crystal orientations and a two-phase analysis of the samples. Investigations were performed on a variety of melt-textured YBCO samples. In melt-textured YBCO with (001) orientation, we find that the embedded 211 particles do not have any preferred orientation. The EBSD maps also reveal that at certain orientations of the 211 particles the YBCO growth is not altered. From the obtained EBSD mappings, we can conclude that the formation of small 211 particles will not disturb the YBCO matrix growth, whereas the presence of large 211 particles causes severe changes in the YBCO growth, leading to the formation of subgrains. The EBSD results are presented in the form of local orientation maps and local pole figures.

  2. Structure of human ubiquitin-conjugating enzyme E2 G2 (UBE2G2/UBC7)

    SciTech Connect

    Arai, Ryoichi; Yoshikawa, Seiko; Murayama, Kazutaka; Imai, Yuzuru; Takahashi, Ryosuke; Shirouzu, Mikako; Yokoyama, Shigeyuki

    2006-04-01

    The crystal structure of human UBE2G2/UBC7 was solved at 2.56 Å resolution. The superimposition of UBE2G2 on UbcH7 in a c-Cbl–UbcH7–ZAP70 ternary complex suggested that the two loop regions of UBE2G2 interact with the RING domain in a similar way as UbcH7. The human ubiquitin-conjugating enzyme E2 G2 (UBE2G2/UBC7) is involved in protein degradation, including a process known as endoplasmic reticulum-associated degradation (ERAD). The crystal structure of human UBE2G2/UBC7 was solved at 2.56 Å resolution. The UBE2G2 structure comprises a single domain consisting of an antiparallel β-sheet with four strands, five α-helices and two 3{sub 10}-helices. Structural comparison of human UBE2G2 with yeast Ubc7 indicated that the overall structures are similar except for the long loop region and the C-terminal helix. Superimposition of UBE2G2 on UbcH7 in a c-Cbl–UbcH7–ZAP70 ternary complex suggested that the two loop regions of UBE2G2 interact with the RING domain in a similar way to UbcH7. In addition, the extra loop region of UBE2G2 may interact with the RING domain or its neighbouring region and may be involved in the binding specificity and stability.

  3. The use of monolithic YBCO in electromagnetic launchers

    NASA Astrophysics Data System (ADS)

    Putman, Philip T.

    One of the fundamental barriers to the use of electromagnetic launchers is the high power required to reach launch speed in a reasonable distance. It has been proposed that large external power supplies can be avoided by using superconducting persistent currents in the barrel of the launcher to store energy. This study examines the use of monolithic YBCO for these persistent current magnets. Monolithic magnets, unlike wound magnets, can have a nonuniform current distribution, which causes energy transfer between the stationary energy storage magnets and the accelerated magnet to be inefficient. This problem can be overcome by optimization of the magnet shape. This requires a model for computation of current distribution, force vs. distance, and efficiency. A model is presented for calculating the current distribution and magnetic force for two YBCO rings, each with a trapped field such that an attractive force is developed between them. Two different methods were used to find current as a function of time. The first is a system of differential equations for the time dependence of the current distribution, which is solved using the 4-step vector Runge-Kutta method. The second is a speed-independent approximation that is less computationally intensive. The integral equation for force at each time step is solved using the finite sum method. After verifying the speed-dependent model by comparing computations to measured force vs. distance curves for twenty-eight pairs of YBCO magnets, the model was used to examine behavior at speeds up to 10,000 m/s. It was found that energy transfer is almost independent of speed for a properly designed launcher. Also, heating due to flux flow was found to be minimal. The fact that energy transfer did not depend on speed allowed the speed-independent model to be used with an optimizer to find a more efficient shape for the accelerated YBCO magnet. A magnet of this shape was fabricated, and efficiency was measured to be 84%, compared

  4. Investigation of Radiation Affected High Temperature Superconductors - YBCO

    NASA Astrophysics Data System (ADS)

    Veterníková, J.; Chudý, M.; Slugeň, V.; Sojak, S.; Degmová, J.; Snopek, J.

    In this paper, high temperature superconductors are studied in terms of radiation stability, which is necessary for application in fusion reactors. Perspective superconducting materials based on YBCO (Perkovskite structure) were measured by positron annihilation lifetime spectroscopy. Measurements were performed for samples prior to and after fast neutron irradiation in TRIGA MARK II reactor in Vienna. The samples demonstrated accumulation of Cu-O di-vacancies due to the irradiation. Nevertheless, the structure showed regeneration during thermal treatment by defects recombination. Positron spectroscopy results were complemented with values of critical temperature, which also showed changes of superconducting properties after the irradiation and the annealing.

  5. Progress of 275 kV-3 kA YBCO HTS cable

    NASA Astrophysics Data System (ADS)

    Yagi, M.; Mukoyama, S.; Amemiya, N.; Ishiyama, A.; Wang, X.; Aoki, Y.; Saito, T.; Ohkuma, T.; Maruyama, O.

    2011-11-01

    A 275 kV-3 kA high temperature superconducting (HTS) cable has been developed in the Materials & Power Applications of Coated Conductors (M-PACC) project. AC loss reduction of a two-layer HTS conductor was undertaken by removing the edges of YBCO tapes with low critical current density. The HTS conductor using these tapes was fabricated, and low loss of 0.235 W/m at 3 kA rms was achieved. The 275 kV-3 kA cable was designed, and the 2 m model cables were fabricated. This cable had 325 mm 2 copper stranded former inside the HTS conductor and a 310 mm 2 copper shield layer on the HTS shield layer for over-current protection. These cables withstood an over-current of 63.0 kA for 0.6 s, which is the worst situation for 275 kV systems. The partial discharge (PD) and V- t characteristics of a liquid nitrogen (LN 2)/polypropylene (PP) laminated paper composite insulation system have been integrated into the design of the insulation for the 275 kV cable. The results revealed that the PD inception stress (PDIE) did not depend on the insulation thickness, and that lifetime indices of V- t characteristics at PD inception were as high as about 80-100.

  6. Thermal stability of NdBCO/YBCO/MgO thin film seeds

    NASA Astrophysics Data System (ADS)

    Volochová, D.; Kavečanský, V.; Antal, V.; Diko, P.; Yao, X.

    2016-04-01

    Thermal stability of the Nd1+x Ba2-x Cu3O7-δ (Nd-123 or NdBCO) thin films deposited on MgO substrate, with YBa2Cu3O7-δ (Y-123 or YBCO) buffer layer (NdBCO/YBCO/MgO thin film), has been experimentally studied in order to determine the optimal film thickness acting as seed for bulk YBCO growth. YBCO bulk superconductors with Y2BaCuO5 (Y-211) and CeO2 addition were prepared by the top seeded melt growth process in a chamber furnace using NdBCO/YBCO/MgO thin film seeds of different thicknesses (200-700 nm with 20 nm YBCO buffer layer) and different maximum temperatures, T max. The maximum temperatures varied in the range of 1040 °C-1125 °C. The highest thermal stability 1118 °C was observed in the case of NdBCO/YBCO/MgO thin film of 300 nm thickness. These results are corroborated with differential scanning calorimetry and high temperature x-ray diffraction measurements, as well as microstructure observations.

  7. A YBCO RF-SQUID magnetometer and its applications

    NASA Technical Reports Server (NTRS)

    Luwei, Zhou; Jingwu, Qiu; Xienfeng, Zhang; Zhiming, Tank; Yongjia, Qian

    1990-01-01

    An applicable RF-superconducting quantum interference detector (SQUID) magnetometer was made using a bulk sintered yttrium barium copper oxide (YBCO). The temperature range of the magnetometer is 77 to 300 K and the field range 0 to 0.1T. At 77 K, the equivalent flux noise of the SQUID is 5 x 10 to minus 4 power theta sub o/square root of Hz at the frequency range of 20 to 200 Hz. The experiments show that the SQUID noise at low-frequency end is mainly from 1/f noise. A coil test shows that the magnetic moment sensitivity delta m is 10 to the minus 6th power emu. The RF-SQUID is shielded in a YBCO cylinder with a shielding ability B sub in/B sub ex of about 10 to the minus 6th power when external dc magnetic field is about a few Oe. The magnetometer is successfully used in characterizing superconducting thin films.

  8. Formation of superconducting junctions in MT-YBCO

    NASA Astrophysics Data System (ADS)

    Prikhna, T. A.; Gawalek, W.; Novikov, N. V.; Moshchil, V. E.; Sverdun, V. B.; Sergienko, N. V.; Surzhenko, A. B.; Uspenskaya, L. S.; Viznichenko, R.; Kordyuk, A. A.; Litzkendorf, D.; Habisreuther, T.; Krachunovska, S.; Vlasenko, A. V.

    2005-02-01

    The formation of superconducting junctions between MT-YBCO using TmBa2Cu3O7-δ powder as a solder has been studied. The method proposed excludes the step of a very slow cooling (at a rate of several degrees per hour) during seam formation. The heating and cooling rate for joining parts produced from single-domain material without visible cracks (macrocracks) can be rather high (500-1000 K h-1) and a holding time at the highest temperature (1010 °C) of several minutes (0.05 h) is enough to form a reliable junction. Reasonable rates of heating and cooling are however around 100 K h-1 if crack propagation is to be avoided in joined blocks used for practical application. Modelling experiments on rings and studies of the ring properties by vibrating sample magnetometer (VSM), field mapping with a Hall probe and magneto-optical microscopy have shown that superconducting properties of the junction were not lower than that of the joined material (jc of about 30 kA cm-2 was observed in zero field at 77 K) and that the proposed process of joining did not adversely affect the properties of the material. The structure of the resulting junction was in good agreement with the structure of MT-YBCO.

  9. Limitations for the trapped field in large grain YBCO superconductors

    NASA Astrophysics Data System (ADS)

    Eisterer, M.; Haindl, S.; Zehetmayer, M.; Gonzalez-Arrabal, R.; Weber, H. W.; Litzkendorf, D.; Zeisberger, M.; Habisreuther, T.; Gawalek, W.; Shlyk, L.; Krabbes, G.

    2006-07-01

    The actual limitations for the trapped field in YBa2Cu3O7-δ (YBCO) monoliths are discussed. The influence of the sample geometry and of the critical current density on the trapped field is investigated by numerical calculations. The field dependence of the critical current density strongly influences the trapped field. A nonlinear relationship between the sample size, the critical current density and the resulting trapped field is derived. The maximum achievable trapped field in YBCO at 77 K is found to be around 2.5 T. This limit is obtained for reasonable geometries and high but realistic critical current densities. Such high fields have not been reached experimentally so far, due to non-optimized flux pinning and material inhomogeneities. These inhomogeneities can be directly assessed by the magnetoscan technique, and their influence is discussed. Significant differences between the a- and the c-growth sectors were found. Limitations due to cracks and non-superconducting inclusions (e.g. 211 particles) are estimated and found to be candidates for variations of Jc on a millimetre length scale, as observed in experiments.

  10. Towards G2G: Systems of Technology Database Systems

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Bell, David

    2005-01-01

    We present an approach and methodology for developing Government-to-Government (G2G) Systems of Technology Database Systems. G2G will deliver technologies for distributed and remote integration of technology data for internal use in analysis and planning as well as for external communications. G2G enables NASA managers, engineers, operational teams and information systems to "compose" technology roadmaps and plans by selecting, combining, extending, specializing and modifying components of technology database systems. G2G will interoperate information and knowledge that is distributed across organizational entities involved that is ideal for NASA future Exploration Enterprise. Key contributions of the G2G system will include the creation of an integrated approach to sustain effective management of technology investments that supports the ability of various technology database systems to be independently managed. The integration technology will comply with emerging open standards. Applications can thus be customized for local needs while enabling an integrated management of technology approach that serves the global needs of NASA. The G2G capabilities will use NASA s breakthrough in database "composition" and integration technology, will use and advance emerging open standards, and will use commercial information technologies to enable effective System of Technology Database systems.

  11. Thermodynamic Study of UO3(g), UO2(OH)2(g), UO2Cl2(g), and UO2F2(g)

    SciTech Connect

    Ebbinghaus, B B; Krikorian, O H; Fleming, D L

    2002-11-07

    Using the transpiration method, the volatility of uranium oxide in the presence of oxygen and water vapor has been measured at temperatures ranging from 1173 to 1573 K and the volatility of uranium oxide in the presence of oxygen and chlorine has been measured at 1175 K. The major vapor species in the presence of oxygen and water vapor are found to be UO{sub 3}(g) and UO{sub 2}(0H){sub 2}(g). Third law treatment of the vaporization data yields {Delta}H{sub f}{sup o}(298) values of -790.52 {+-} 7.32 and -1199.94 {+-} 10.25 kJ/mol, respectively. The major vapor species in the presence of oxygen and chlorine is found to be UO{sub 2}Cl{sub 2}(g). Third law treatment of the vaporization data yields a {Delta}H{sub f}{sup o}(298) value of -1002.04 {+-} 3.26 kJ/mol. From an assessment of all the thermodynamic data available for UO{sub 3}(g), UO{sub 2}(OH){sub 2}(g), UO{sub 2}Cl{sub 2}(g), and UO{sub 2}F{sub 2}(g), the best {Delta}H{sub f{sup o}}(298) values for each of these species are calculated to be -796.74 {+-} 3.52, -1199.94 {+-} 10.25, -999.64 {+-} 2.40, and -1369.22 {+-} 2.87 kJ/mol, respectively. From these, the {Delta}H{sub f{sup o}} (298) values for UO{sub 2}ClOH(g), UO{sub 2}FOH(g), and UO{sub 2}FCl(g) are estimated to be -1099.79, -1284.58, and -1184.43 kJ/mol, respectively. The thermodynamic data for all the vapor species are then applied to conditions one might expect in a thermal oxidation processor for mixed waste to estimate the amount of uranium volatility.

  12. Properties of large-scale melt-processed YBCO samples

    NASA Astrophysics Data System (ADS)

    Gauss, S.; Elschner, S.; Bestgen, H.

    Magnetic bearings and superconducting permanent magnets are some of the first possible applications of bulk high Tc superconductors. Large samples were prepared by a new melt process starting from reacted YBCO 123 and 211 powders. The addition of PtO 2 to the mixture led to reduced 211 inclusion size and better homogeneity. Simultaneously the density of microcracks dividing the a- b basal plane was reduced. For testing the overall magnetic properties of these samples magnetization and levitation force measurements were performed. In comparison to samples without PtO 2 addition a strong increase in the magnetization M and the repulsion force from a magnet were observed. The maximum in the field dependence of M increased to more than 1000 G. According to the time dependence of the trapped field after a field cooling experiment an acceptable flux creep at 77 K for a long-term application was achieved.

  13. Magnetic coupling by using levitation characteristics of YBCO superconductors

    NASA Astrophysics Data System (ADS)

    Ishigaki, H.; Ito, H.; Itoh, M.; Hida, A.; Takahata, R.

    1993-03-01

    A mechanical system which uses high lateral restoring forces of high-Tc materials as the driving force for a magnetic coupling is proposed. As the basic study of the superconducting magnetic coupling, the relationship between the lateral restoring force and levitation force, transmitted torque characteristics as a function of a twisting angle and clearance, and damping characteristics of the coupling were examined. Superiorities of the coupling such as high damping coefficients and high stability against time and twisting angle were revealed. A magnetic force sensor system was used to evaluate the superconducting characteristics of materials, and nonuniform distribution of repulsive force was observed for the YBCO pellet fabricated by the melt-powder-melt-growth process. The improvement of the homogeneity was achieved by compensating for the composition rate which had changed during the quenching process.

  14. Texture analysis of melt-textured YBCO superconductors

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Simon, P.; Ogasawara, K.; Murakami, M.

    2003-10-01

    We compare the results of an X-ray based pole figure texture analysis with the local texture analysis by means of electron-backscatter diffraction (EBSD) analysis. As samples, we employ two different melt-textured YBCO samples; one fully processed and one without oxygen treatment. To enable the direct comparison of the two techniques, we employ the [1 0 3] pole figures. We find a clear coincidence between the results obtained by the two measurement techniques on our samples, however, the EBSD results are much more detailed, yielding the local grain orientation distribution and quantitative results of the grain or subgrain misorientation angles. Therefore, the EBSD measurements give information not accessible to the X-ray pole figure analysis. The surface preparation procedure is essential to enable the automated EBSD mapping as high image quality Kikuchi patterns are required. The polishing procedures are discussed in detail.

  15. Metallization and interconnection of HTS YBCO thin film devices and circuits

    NASA Astrophysics Data System (ADS)

    Du, J.; Lam, S. K. H.; Tilbrook, D. L.

    2001-10-01

    A comprehensive study of specific contact resistivity and ultrasonic wire bonding yield and strength was carried out on noble metal-YBa2Cu3O7-x (YBCO) thin film contacts prepared by a variety of methods and with different YBCO surface conditions. The metallization techniques investigated include in situ and ex situ deposition of gold or silver on YBCO films. The ex situ contacts were made with and without lithographic processes. Contact resistivities of less than 5×10-8 Ω cm2 at 77 K were achieved for contacts made by the rapid ex situ deposition of gold or silver on fresh YBCO films with smooth surfaces. These contacts also gave a high wire bonding yield and strength of 10-19 g. High contact resistivities in excess of 5×10-4 Ω cm2 and poor wire bonding yield and strength were observed for the contacts made by standard lithographic lift-off processes on old YBCO films. Surface treatments using either argon ion beam etching or rf O2 plasma cleaning prior to metallization were found to be useful in reducing the contact resistivity and improving the wire bonding results for the lift-off contacts. The influence of YBCO film morphology on the contact resistance and wire bonding yield and strength was also studied.

  16. Temperature regulation in rats exposed to a 2 G field

    NASA Technical Reports Server (NTRS)

    Ishihama, Linda M.; Murakami, Dean M.; Fuller, Charles A.

    1989-01-01

    The regulation of body temperature involves both homeostatic and circadian control systems. Both systems are influenced by exposure to hyperdynamic fields and demonstrate acute responses that eventually recover to an adapted level. This experiment examined both the homeostatic and circadian responses of body temperature to a separate environmental challenge (high frequency light/dark cycles) during exposure to a 2 G hyperdynamic field.

  17. Measuring the performance of G2G services in Iran

    NASA Astrophysics Data System (ADS)

    Zarei, Behrouz; Safdari, Maryam

    To highlight the growth of e-government and the importance of its services it is essential to evaluate the performance of the service delivery to customers. Research indicates that traditional performance indexes are not suitable for this evaluation; moreover, it is noticeable that the e-government services are intangible and invisible. Among different e-government services, measurement of quality government to government (G2G) services has been less attractive for researchers while crucial for government policy-makers. This calls for a better understanding of the specific needs of users of these services in order to provide appropriate type and level of services that meets those needs. In this paper, the performance of the G2G services is measured in the Iranian context. For this purpose, SERVQUAL, which is a well-known method for assessing service quality, is employed. This study proposes and tests a five-factor of SERVQUAL instrument to explain user satisfaction and gap analysis, between expectations and perceptions of its customers, consisting thirty ministries and main governmental organizations. Based on a Chi-square test, factor analysis, gap analysis and correlations, it is concluded the gap between expectations and perceptions of G2G customers is significant and customer satisfaction of G2G services is at low level.

  18. Deposition of YBCO thin films on silver substrate via a fluorine-free sol-gel synthesis

    NASA Astrophysics Data System (ADS)

    Xu, Yongli; Shi, Donglu; Lian, L.; Wang, M.; McClellan, Shaun M.

    2002-05-01

    To further develop grain-textured YBCO thin films for conductor development, we deposited, via a fluorine-free sol-gel synthesis, YBCO thin films on non-textured silver substrate. The interface structures were studied by both x-ray diffraction (XRD) and transmission electron microscopy (HRTEM). XRD data indicated that the YBCO films on silver substrate exhibited c-axis grain orientations. Experimental details are reported on the sol-gel synthesis chemistry and XRD and HRTEM characterization of the YBCO thin films.

  19. ME-μSR study in YBCO vortex states.

    NASA Astrophysics Data System (ADS)

    Le, T. H.; Boekema, C.

    2007-03-01

    We are analyzing μSR vortex data of YBa2Cu3O7-δ (Tc = 91 K). The average superconducting grain size is ˜20 μm. The μSR data are recorded in a transverse 1 kOe field and at temperatures below 10 K. The μSR technique is used to probe the magnetic fields in the cuprate vortex state. The μSR signals show an oscillatory time dependence. To determine the frequency-dependent signals, we use the Maximum Entropy (ME) transform technique. [2] The ME-Burg algorithm removes noise, and does not suffer from Fourier-like truncation effects. The frequency signals are better fit with Lorentzians than static Gaussians. This Lorentzian behavior indicates the existence of dynamic magnetism in and around the vortex cores. This is consistent with earlier YBCO vortex ME-μSR results [3] and the SO(5) modeling [4] of cuprate superconductivity, predicting the existence of antiferromagnetism in the vortex states. Research is supported by NSF-REU and WiSE at SJSU. [1] C. Boekema et al, Physica C282-287 (1997) 2069. [2] J Lee et al, J Appl Phys 95 (2004) 6906 and ref therein; AIP www: Virtual J Appl of Superconductivity 2004 V6 Iss11. [3] C. Boekema et al, 8th Int M2S-HTSC Conf, Physica C in press. [4] H-D Chen et al, Phys Rev B70 (2004) 024516; SC Zhang, Science 275 (1997) 1089.

  20. Nanoscale inhomogeneities in yttrium-barium-copper-oxide (YBCO) superconductors

    NASA Astrophysics Data System (ADS)

    Islam, Zahirul; Sinha, S. K.; Lang, J. C.; Liu, X.; Haskel, D.; Moss, S. C.; Srajer, G.; Veal, B. W.; Wermeille, D.; Lee, D. R.; Haeffner, D. R.; Welp, U.; Wochner, P.

    2004-03-01

    X-ray diffraction studies at the Advanced Photon Source reveal that nanoscale inhomogeneities, electronic or structural in origin, form in yttrium-barium-copper-oxide (YBa_2Cu_3O_6+x) superconductors and coexist with the superconducting (SC) state. Diffuse scattering from these inhomogeneous superstructures is due to atomic displacements with respect to equilibrium lattice sites (Z. Islam et al. Phys. Rev. B 66, 92501 (2002)), that are characterized by a wavevector of the form q=(q_x,0,0), where qx varies with hole doping from 2 unit cells (along shorter Cu-O-Cu direction) for very low doping to 4 unit cells at optimal doping. Interestingly, while these superstructures are 3-dimensionally ordered when the SC state is weakened (e.g., at x=0.4), as the doping increases, they become quasi 1D with correlation lengths comparable to SC coherence lengths in these cuprates. Recent first-principles calculations (D. de Fontaine et al., to be published) for the x=0.63 compound show that atomic displacements consistent with experimental data can be the result of ordering of O vacancies in YBCO. Models for various superstructures and their role in the phase diagram will be discussed.

  1. Electric field poling 2G V/m to improve piezoelectricity of PVDF thin film

    NASA Astrophysics Data System (ADS)

    Hartono, Ambran; Darwin, Ramli, Satira, Suparno; Djamal, Mitra; Herman

    2016-03-01

    Polyvinylidene fluoride (PVDF) is a polymer with unique characteristics i.e. piezoelectric and ferrroelectric properties. Piezoelectric propertiesof PVDF are determined by the fraction of β-phase structure. Several optimization methods have been developed to improve the piezoelectric properties of PVDF. One of our research efforts is to improve the piezoelectricity of PVDF by electric poling with high electric field 2G V/m. The application of high electric field performed on PVDF films with a thickness of 1 1m. Each sample was made with a deep coating method, with annealing temperature 70°C-110°C. Based on the XRD characterization, we have obtained value of β-fraction of samples after poling are: 56%, 61%, 77%, 81% and 83%, respectively. Therefore, high electric field poling has been able to improve the piezoelectric properties of PVDF films. The PVDF with good piezoelectric properties are potential can did a tes for piezoelectric sensors and actuators devices.

  2. Propagation characteristics of the magnetostatic surface wave in the YBCO-YIG film-layered structure

    SciTech Connect

    Tsutsumi, M.; Fukusako, T.; Yoshida, S.

    1996-08-01

    Propagation characteristics of the magnetostatic surface wave (MSSW) in a YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (YBCO)-yttrium iron garnet (YIG) multilayered structure are investigated. Effects of the superconductor on the MSSW are discussed with regard to the dispersion characteristics of both the phase and attenuation constants as a function of the air gap between YIG and YBCO, taking into consideration the magnetic line-width of the YIG film. It was found that the nonreciprocity of MSSW is enhanced significantly by the superconductivity and depends on the magnetic line-width of the YIG film. To examine the effect of a YBCO on the MSSW propagation, experiments are carried out using a commercially available YIG film. Magnetic losses at low temperature are briefly discussed with experimentally observed nonreciprocity.

  3. Structural and electrical properties of epitaxial YBCO films on Si (Abstract Only).

    NASA Astrophysics Data System (ADS)

    Fork, David K.; Barrera, A.; Phillips, Julia M.; Newman, N.; Fenner, David B.; Geballe, Theodore H.; Connell, G. A. N.; Boyce, James B.

    1991-03-01

    Efforts to grow high quality films of YBCO on Si have been complicated by factors discussed in Ref. 1, chief among them being the reaction between YBCO and Si, which is damaging even at 550 C. This is well below the customary temperatures for YBCO film growth. To avoid the reaction problem, epitaxial YBCO films were grown on Si (100) using an intermediate buffer layer of yttria-stabilized zirconia (YSZ).2 Both layers are grown via an entirely in situ process by pulsed laser deposition (PLD). Although the buffer layer prevents reaction, another problem arises; the large difference in thermal expansion coefficients between silicon and YBCO causes strain at room temperature. Thin (<500 A) YBCO films are unrelaxed and under tensile strain with a distorted unit cell. Thicker films are cracked and have poorer electrical properties. The thermal strain may be reduced by growing on silicon-on-sapphire (SOS) rather than silicon.3 This allows the growth of films of arbitrary thickness. Ion channeling reveals a high degree of crystalline perfection with a channeling minimum yield for Ba as low as 12% on either silicon or SOS. The normal state resistivity is 250-300 i-cm at 300 K; the critical temperature, Tc (R=0), is 86-88 K with a transition width (ATc) of I K. Critical current densities (J)°f 2x107 A/cm2 at 4.2 K and >2x106 A/cm2 at 77 K have been achieved. In addition, the surface resistance of a YBCO film on SOS was measured against Nb at 4.2 K. At 10 GHz, a value of 45 was obtained. This compares favorably to values reported for LaAlO3. Application of this technology to produce reaction patterned microstrip lines has been tested.4 This was done by ion milling away portions of the YSZ buffer layer prior to the YBCO deposition. YBCO landing on regions of exposed Si reacts to form an insulator. This technique was used to make 3 micron lines 1.5 mm long. The resulting structure had a Jc of l.6xl06 A/cm2 at 77 K. Isolation of separate structures exceeded 20 M. Several

  4. YBCO thin films on CeO2 buffered silver substrates

    NASA Astrophysics Data System (ADS)

    Gallistl, B.; Gritzner, G.

    2008-02-01

    CeO2 was deposited on silver substrates by the chemical solution deposition method. Silver was dipped into a 0.05 M Ce(NO3)3 solution, dried in air and then annealed in air at 900 °C for 30 minutes. The CeO2 buffer layer was characterized by X-ray diffraction and scanning electron microscopy. YBCO was deposited onto the buffered substrate via screen printing. The YBCO films where sintered at temperatures of 880 °C and 890 °C. Dense and crack free YBCO layers were obtained with transition temperatures (Tc0) up to 83 K. Characterization of the superconducting film was performed by X-ray diffraction and SEM.

  5. YBCO thin film evaporation on as-deposited silver film on MgO

    NASA Astrophysics Data System (ADS)

    Azoulay, J.

    1999-11-01

    YBa 2Cu 3O 7- δ (YBCO) thin film was evaporated on as-deposited Ag buffer layer on MgO substrate. A simple, inexpensive vacuum system equipped with one resistively heated source was used. The subsequent heat treatment was carried out under low oxygen partial pressure at a relatively low temperature and short dwelling time. The films thus obtained were characterized for electrical properties using DC four-probe electrical measurements and inspected for structural properties and chemical composition by scanning electron microscopy (SEM). It is shown that YBCO thin film can grow on as-deposited thin silver layer on MgO substrate.

  6. Transient Electromagnetic Phenomena during Current Limiting Process in YBCO Thin Film

    NASA Astrophysics Data System (ADS)

    Ichiki, Y.; Ohsaki, H.

    2006-06-01

    In order to design a reliable and high-performance fault current limiter, it is necessary to estimate the influences of the inhomogeneous superconducting properties on the current limiting process and S-N transition. This paper describes the measurements of transient electromagnetic phenomena in YBCO thin film using pick-up coils to observe current-sharing process and change of current distribution. At first current distribution in a steady state was measured. And then transient phenomena caused by applying an overcurrent to YBCO thin film covered with a silver layer were measured.

  7. Levitation forces of a bulk YBCO superconductor in gradient varying magnetic fields

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Gong, Y. M.; Wang, G.; Zhou, D. J.; Zhao, L. F.; Zhang, Y.; Zhao, Y.

    2015-09-01

    The levitation forces of a bulk YBCO superconductor in gradient varying high and low magnetic fields generated from a superconducting magnet were investigated. The magnetic field intensity of the superconducting magnet was measured when the exciting current was 90 A. The magnetic field gradient and magnetic force field were both calculated. The YBCO bulk was cooled by liquid nitrogen in field-cooling (FC) and zero-field-cooling (ZFC) condition. The results showed that the levitation forces increased with increasing the magnetic field intensity. Moreover, the levitation forces were more dependent on magnetic field gradient and magnetic force field than magnetic field intensity.

  8. National accelerated coated conductor initiative

    NASA Astrophysics Data System (ADS)

    Hawsey, Robert A.; Peterson, Dean E.

    2002-01-01

    The national Accelerated Coated Conductor Initiative (ACCI) is committed to assuring continued U.S. leadership in the development of high-temperature superconducting (HTS) wire for electric power and other applications of national interest. Increased energy efficiency, power density, and power-to-weight ratio are just a few of the tangible benefits that will be possible if today's meter lengths of HTS wire based upon the compound yttrium-barium-copper-oxygen (YBCO) can be scaled up by U.S. industry to kilometer lengths. This paper presents an evaluation of the current state of the development of coated conductor technology and a vision for its future. The challenges that U.S. Department of Energy (DOE) laboratories and their industrial and university partners face will be presented against the backdrop of the history of superconductivity program achievements. It is the purpose of this initiative to accelerate the development, commercialization, and application of high temperature superconductors through joint efforts among DOE laboratories, American industry, and universities, so that future challenges of the electric power industry can be met. Based on their advances in HTS coated conductor development in a program funded by the DOE's Office of Power Technologies, Los Alamos and Oak Ridge National Laboratories lead and support this effort by improving their own capabilities, including equipment, facilities, and technical expertise. Each laboratory has, in 2001, acquired new laboratory space, new capital equipment, and new personnel with the goal of working closely with U.S. companies to take technologies invented in the labs and demonstrated in 1-m lengths and transfer these technologies to the commercial sector. The present status of the performance of the second-generation YBCO wires will be described, and the future plans of the national laboratories will be presented. Opportunities for collaboration are discussed, as well. .

  9. A comparative study on in situ grown superconducting YBCO and YBCO-Ag thin films by PLD on polycrystalline SmBa2NbO6 substrate

    NASA Astrophysics Data System (ADS)

    Kurian, J.; John, Asha M.; Wariar, P. R. S.; Sajith, P. K.; Koshy, J.; Pai, S. P.; Pinto, R.

    2000-02-01

    The development and characterization of SmBa2NbO6, which is a new ceramic substrate material for the YBa2Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> superconductor, are reported. SmBa2NbO6 has a complex cubic perovskite structure with lattice constant a = 8.524 Å. The dielectric properties of SmBa2NbO6 are in a range suitable for its use as a substrate for microwave applications. SmBa2NbO6 was found to have a thermal conductivity of 77 W m-1 K-1 and a thermal expansion coefficient of 7.8 × 10-6 °C-1 at room temperature. Superconducting YBa2 Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> and YBa2Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> -Ag thin films have been grown in situ on polycrystalline SmBa2NbO6 by the pulsed laser ablation technique. The films exhibited (00l) orientation of an orthorhombic YBa2 Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> phase and gave a zero resistivity superconducting transition (TC(0)) at 90 K with a transition width of ~1.5 K. The critical current density of YBCO-Ag thin films grown on polycrystalline SmBa2NbO6 substrate was ~3 × 105 A cm-2 at 77 K. A comparative study of YBCO and YBCO-Ag thin films developed on polycrystalline SmBa2NbO6 substrate by PLD based on the crystallinity, orientation and critical current density of the YBCO film is discussed in detail.

  10. Muscle phenotypic variability in limb girdle muscular dystrophy 2 G.

    PubMed

    Paim, Julia F; Cotta, Ana; Vargas, Antonio P; Navarro, Monica M; Valicek, Jaquelin; Carvalho, Elmano; da-Cunha, Antonio L; Plentz, Estevão; Braz, Shelida V; Takata, Reinaldo I; Almeida, Camila F; Vainzof, Mariz

    2013-06-01

    Limb girdle muscular dystrophy type 2 G (LGMD2G) is caused by mutations in the telethonin gene. Only few families were described presenting this disease, and they are mainly Brazilians. Here, we identified one additional case carrying the same common c.157C > T mutation in the telethonin gene but with an atypical histopathological muscle pattern. In a female patient with a long duration of symptoms (46 years), muscle biopsy showed, in addition to telethonin deficiency, the presence of nemaline rods, type 1 fiber predominance, nuclear internalization, lobulated fibers, and mitochondrial paracrystalline inclusions. Her first clinical signs were identified at 8 years old, which include tiptoe walking, left lower limb deformity, and frequent falls. Ambulation loss occurred at 41 years old, and now, at 54 years old, she presented pelvic girdle atrophy, winging scapula, foot deformity with incapacity to perform ankle dorsiflexion, and absent tendon reflexes. The presence of nemaline bodies could be a secondary phenomenon, possibly associated with focal Z-line abnormalities of a long-standing disease. However, these new histopathological findings, characteristic of congenital myopathies, expand muscle phenotypic variability of telethoninopathy. PMID:23479141

  11. Effects of thickness on superconducting properties and structures of Y2O3/BZO-doped MOD-YBCO films

    NASA Astrophysics Data System (ADS)

    Ding, Fa-Zhu; Gu, Hong-Wei; Wang, Hong-Yan; Zhang, Hui-Liang; Zhang, Teng; Qu, Fei; Dong, Ze-Bin; Zhou, Wei-Wei

    2015-05-01

    We report the thickness dependence of critical current density (Jc) in YBa2Cu3O7-x (YBCO) films with BaZrO3 (BZO) and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using trifluoroacetates (TFA-MOD). Comparing with pure YBCO films, the Jc of BZO/Y2O3-doped YBCO films was significantly enhanced. It was also found that with the increase of the thickness of YBCO film from 0.25 μm to 1.5 μm, the Ic of BZO/Y2O3-doped YBCO film increased from 130 A/cm to 250 A/cm and yet Jc of YBCO film decreased from 6.5 MA/cm2 to 2.5 M A/cm2. The thick BZO/Y2O3-doped MOD-YBCO film showed lower Jc, which is mainly attributed to the formation of a-axis grains and pores. Project supported by the National Natural Science Foundation of China (Grant No. 51272250), the National Basic Research Program of China (Grant No. 2011CBA00105), the National High Technology Research and Development Program of China (Grant No. 2014AA032702), and the Beijing Natural Science Foundation, China (Grant No. 2152035).

  12. Critical current behavior of Ag-coated YBa2Cu3O(7-x) thin films

    NASA Astrophysics Data System (ADS)

    Ono, R. H.; Beall, J. A.; Harvey, T. E.; Reintsema, C. D.; Johansson, M.

    1991-03-01

    The authors studied the behavior of high-quality YBa2Cu3O(7-x) (YBCO) thin films with Ag overlayers. The authors chose to study Ag in detail because of its widespread use as contact metallization and because of their earlier studies of proximity effects in YBCO. The details of transport critical current measurements are presented. It is shown that the Ag coatings can reduce normal state resistance while not degrading the critical current density. The key technological result is that the various thicknesses of Ag that were used did not reduce Jc or Jc(H). Critical current densities in excess of 106 A/sq cm have been achieved at temperatures greater than 76 K. An unusual effect was seen in Jc(H) when the field was oriented perpendicular to the c axis of the film. The Jc at 1 T was higher in samples with 10-nm coatings of Ag than in similar uncoated samples. It was also shown that the composite resistance of Ag-YBCO bilayers can be much lower than the resistance of uncoated YBCO.

  13. New method for introducing nanometer flux pinning centers into single domain YBCO bulk superconductors

    NASA Astrophysics Data System (ADS)

    Yang, W. M.; Wang, Miao

    2013-10-01

    Single domain YBCO superconductors with different additions of Bi2O3 have been fabricated by top seeded infiltration and growth process (TSIG). The effect of Bi2O3 additions on the growth morphology, microstructure and levitation force of the YBCO bulk superconductor has been investigated. The results indicate that single domain YBCO superconductors can be fabricated with the additions of Bi2O3 less than 2 wt%; Bi2O3 can be reacted with Y2BaCuO5 and liquid phase and finally form Y2Ba4CuBiOx(YBi2411) nanoscale particles; the size of the YBi2411 particles is about 100 nm, which can act as effective flux pinning centers. It is also found that the levitation force of single domain YBCO bulks is increasing from 13 N to 34 N and decreasing to 11 N with the increasing of Bi2O3 addition from 0.1 wt% to 0.7 wt% and 2 wt%. This result is helpful for us to improve the physical properties of REBCO bulk superconductors.

  14. Experimental studies of helical solenoid model based on YBCO tape-bridge joints

    SciTech Connect

    Yu, M.; Lombardo, V.; Turrioni, D.; Zlobin, A.V.; Flangan, G.; Lopes, M.L.; Johnson, R.P.; /Fermilab

    2011-06-01

    Helical solenoids that provide solenoid, helical dipole and helical gradient field components are designed for a helical cooling channel (HCC) proposed for cooling of muon beams in a muon collider. The high temperature superconductor (HTS), 12 mm wide and 0.1 mm thick YBCO tape, is used as the conductor for the highest-field section of HCC due to certain advantages, such as its electrical and mechanical properties. To study and address the design, and technological and performance issues related to magnets based on YBCO tapes, a short helical solenoid model based on double-pancake coils was designed, fabricated and tested at Fermilab. Splicing joints were made with Sn-Pb solder as the power leads and the connection between coils, which is the most critical element in the magnet that can limit the performance significantly. This paper summarizes the test results of YBCO tape and double-pancake coils in liquid nitrogen and liquid helium, and then focuses on the study of YBCO splices, including the soldering temperatures and pressures, and splice bending test.

  15. Microstructural studies of K 2CO 3 and Rb 2CO 3 doped YBCO HTSC

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.

    2003-10-01

    The influence of Me 2CO 3 (Me=K or Rb) additions on the microstructural morphology of YBa 2Cu 3O x (YBCO) HTSC with nominal composition Y (1-0.2 x) Ba (2-0.2 x) M xCu 3O y ( x=0-2.0) were investigated by means of orientation imaging microscopy which provides a method for measuring a large number of individual grain orientations and relating them directly to the microstructural features by means of evaluating electron backscatter Kikuchi patterns in scanning electron microscopy. We investigated the influence of the alkali additions on the grain orientation distributions of YBCO. The samples are characterized by grain orientation maps, and pole and inverse pole figures. Finally, the grain orientation distribution functions are obtained from the measured data. Within a certain range of doping (up to 5 wt.% in the initial batch), the grain sizes are found to increase as compared to pure YBCO, accompanied by an improvement of the superconducting properties ( Tc). It is shown that the additions of alkali carbonates do not introduce any preferred grain orientations in YBCO HTSC in the entire doping range.

  16. Enhanced pinning in YBCO films with BaZrO.sub.3 nanoparticles

    DOEpatents

    Driscoll, Judith L.; Foltyn, Stephen R.

    2010-06-15

    A process and composition of matter are provided and involve flux pinning in thin films of high temperature superconductive oxides such as YBCO by inclusion of particles including barium and a group 4 or group 5 metal, such as zirconium, in the thin film.

  17. The role of Ag in the pulsed laser growth of YBCO thin films

    NASA Astrophysics Data System (ADS)

    Kalyanaraman, R.; Oktyabrsky, S.; Narayan, J.

    1999-05-01

    We have studied systematically the role of silver in improving microstructure and properties of Y1Ba2Cu3O7-δ (YBCO) thin films. We have more than doubled the grain size to nearly 1.8 μm and reduced processing temperatures by incorporating Ag in the YBCO films, which is accomplished by using a composite target containing 15% by weight of Ag. These films show approximately four times higher Jc than the best films obtained on MgO(001) substrates deposited from stoichiometric Y1Ba2Cu3O7-δ targets. Study of the silver content in the film as a function of the deposition temperature shows clearly a decreasing concentration with increasing temperature and a segregation of the Ag to the surface. The increased oxygen content in the films is also observed at lower processing temperatures, providing strong support for the efficient oxygenation of YBCO via the presence of silver. A qualitative model suggests that the formation of silver oxide, rapid surface diffusion of Ag on MgO surfaces, and the nonreactivity of Ag with YBCO are the key aspects to the improvement in microstructure. The possibility of extending these ideas to the growth of oxides is also discussed, along with the fabrication of in-situ superconducting-metal junctions with 3D geometries.

  18. Trapped Field Characteristics of Stacked YBCO Thin Plates for Compact NMR Magnets: Spatial Field Distribution and Temporal Stability

    PubMed Central

    Hahn, Seungyong; Kim, Seok Beom; Ahn, Min Cheol; Voccio, John; Bascuñán, Juan; Iwasa, Yukikazu

    2010-01-01

    This paper presents experimental and analytical results of trapped field characteristics of a stack of square YBCO thin film plates for compact NMR magnets. Each YBCO plate, 40 mm × 40 mm × 0.08 mm, has a 25-mm diameter hole at its center. A total of 500 stacked plates were used to build a 40-mm long magnet. Its trapped field, in a bath of liquid nitrogen, was measured for spatial field distribution and temporal stability. Comparison of measured and analytical results is presented: the effects on trapped field characteristics of the unsaturated nickel substrate and the non-uniform current distribution in the YBCO plate are discussed. PMID:20585463

  19. Trapped Field Characteristics of Stacked YBCO Thin Plates for Compact NMR Magnets: Spatial Field Distribution and Temporal Stability.

    PubMed

    Hahn, Seungyong; Kim, Seok Beom; Ahn, Min Cheol; Voccio, John; Bascuñán, Juan; Iwasa, Yukikazu

    2010-06-01

    This paper presents experimental and analytical results of trapped field characteristics of a stack of square YBCO thin film plates for compact NMR magnets. Each YBCO plate, 40 mm × 40 mm × 0.08 mm, has a 25-mm diameter hole at its center. A total of 500 stacked plates were used to build a 40-mm long magnet. Its trapped field, in a bath of liquid nitrogen, was measured for spatial field distribution and temporal stability. Comparison of measured and analytical results is presented: the effects on trapped field characteristics of the unsaturated nickel substrate and the non-uniform current distribution in the YBCO plate are discussed.

  20. Double disordered YBCO coated conductors of industrial scale: high currents in high magnetic field

    NASA Astrophysics Data System (ADS)

    Abraimov, D.; Ballarino, A.; Barth, C.; Bottura, L.; Dietrich, R.; Francis, A.; Jaroszynski, J.; Majkic, G. S.; McCallister, J.; Polyanskii, A.; Rossi, L.; Rutt, A.; Santos, M.; Schlenga, K.; Selvamanickam, V.; Senatore, C.; Usoskin, A.; Viouchkov, Y. L.

    2015-11-01

    A significant increase of critical current in high magnetic field, up to 31 T, was recorded in long tapes manufactured by employing a double-disorder route. In a double-disordered high-temperature superconductor (HTS), a superimposing of intrinsic and extrinsic disorder takes place in a way that (i) the intrinsic disorder is caused by local stoichiometry deviations that lead to defects of crystallinity that serve as pining centers in the YBa2Cu3O x-δ matrix and (ii) the extrinsic disorder is introduced via embedded atoms or particles of foreign material (e.g. barium zirconate), which create a set of lattice defects. We analyzed possible technological reasons for this current gain. The properties of these tapes over a wider field-temperature range as well as field anisotropy were also studied. Record values of critical current as high as 309 A at 31 T, 500 A at 18 Tm and 1200 A at 5 T were found in 4 mm wide tape at 4.2 K and B perpendicular to tape surface. HTS layers were processed in medium-scale equipment that allows a maximum batch length of 250 m while 22 m long batches were provided for investigation. Abnormally high ratios (up to 10) of critical current density measured at 4.2 K, 19 T to critical current density measured at 77 K, self-field were observed in tapes with the highest in-field critical current. Anisotropy of the critical current as well as angular dependences of n and α values were investigated. The temperature dependence of critical current is presented for temperatures between 4.2 and 40 K. Prospects for the suppression of the dog-bone effect by Cu plating and upscale of processing chain to >500 m piece length are discussed.

  1. AC loss reduction of TFA-MOD coated conductors in long length by laser scribing technique

    NASA Astrophysics Data System (ADS)

    Katayama, K.; Hirano, H.; Machi, T.; Takagi, Y.; Takahashi, Y.; Izumi, T.

    TFA-MOD process is expected to be promising for future applications since it can produce high performance YBCO coated conductors with low cost. Applying YBCO coated conductors to the power electric devices such as transformer, cable, motors, reduction of AC loss for long wire is necessary. Multifilamentation, which is one of the effective approaches for AC loss reduction, has been developed by the scribing process. YBCO coated conductors produced by our standard TFA-MOD process delaminated into two parts by the laser scribing. The delamination was clarified to occur within the superconducting layer caused by the defects such as pores in the superconducting layer. In order to reduce the defects in the superconducting layer, we modify the heat treatment profile performed on the decomposed precursor films by applying the interim annealing(550-600°C) before crystallization heat treatment(740-770°C). The interim annealed samples had much less and smaller pores than the standard processed ones. The peel strength measured by transverse tensile test was as high as the PLD derived coated conductors which was successfully scribed into five filaments resulting in 1/5 AC loss. A 50m long YBCO coated conductor with the characteristics of 398A/cmwidth was obtained and cut into 5 mm width, followed by the laser scribing process into five filaments. The multifilamentation process was successfully performed without delamination throughout the wire. The hysteresis loss was down to 1/N (N: number of filaments), as we aimed. The IC properties of the filaments were 29±4A, indicating the wire was uniformly fabricated.

  2. Development of YBCO Superconductor for Electric Systems: Cooperative Research and Development Final Report, CRADA Number CRD-04-150

    SciTech Connect

    Bhattacharya, R.

    2013-03-01

    The proposed project will be collaborative in exploration of high temperature superconductor oxide films between SuperPower, Inc. and the National Renewable Energy Laboratory. This CRADA will attempt to develop YBCO based high temperature oxide technology.

  3. Growth and properties of YBCO thin films on polycrystalline Ag substrates by inclined substrate pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Li, M.; Ma, B.; Koritala, R. E.; Fisher, B. L.; Dorris, S. E.; Venkataraman, K.; Balachandran, U.

    2002-06-01

    Fully c-axis-oriented YBCO films were directly deposited on polycrystalline silver substrates by inclined substrate pulsed laser ablation. The orientation and microstructure of the YBCO films were characterized by x-ray diffraction 2θ-scans, Ω-scans and pole figure analysis. Surface morphology was examined by scanning electron microscopy. Irregular-mosaic-shaped supergrains were observed in the films. Raman spectroscopy was used to evaluate the quality of the YBCO films. The superconducting transition temperature (Tc) and the critical current density (Jc) of the films were determined by inductive and transport measurements, respectively. Tc = 91 K with sharp transition and Jc = 2.7 × 105 A cm-2 at 77 K in zero field were obtained on a film that was 0.14 μm thick, 5 mm wide and 10 mm long. This work demonstrated a promising approach to obtain high-Jc YBCO films on nontextured polycrystalline silver substrate.

  4. Tailoring the vortex pinning strength of YBCO thin films by systematic incorporation of hybrid artificial pinning centers

    NASA Astrophysics Data System (ADS)

    Jha, Alok K.; Matsumoto, Kaname; Horide, Tomoya; Saini, Shrikant; Mele, Paolo; Ichinose, Ataru; Yoshida, Yutaka; Awaji, Satoshi

    2015-11-01

    The effect of hybrid (columnar and spherical together) artificial pinning centers (APCs) on the vortex pinning properties of YBa2Cu3O7-δ (YBCO) thin films is investigated in detail on the basis of variation of critical current density (J C ) with applied magnetic field and also with the orientation of the applied magnetic field at 65 K and 77 K. Premixed YBCO + BaSnO3 composite targets are used for the deposition of the YBCO films which consist of self-assembled BaSnO3 nanocolumns (1D APCs); on the other hand, for the deposition of the YBCO films with hybrid APCs (BaSnO3 nanocolumns together with Y2O3 nanoparticles), the surface of the premixed YBCO + BaSnO3 composite targets are modified by putting a thin Y2O3 sectored piece on the premixed YBCO + BaSnO3 composite targets by means of silver paste. F pmax value increases systematically with incorporation of 1D and 1D and 3D APCs and it also shifts towards higher applied magnetic fields. Films with 1D APCs exhibit a strong J C peak at Θ = 0° (H//c-axis) whereas films consisting of hybrid APCs exhibit enhanced J C at all the investigated angular regimes. A possible mechanism of vortex pinning in samples with hybrid APCs is also discussed suggesting the role of 1D and 3D APCs.

  5. The mechanism of sputter-induced orientation change in YBCO films on MgO (001)

    SciTech Connect

    Huang, Y.; Vuchic, B.V.; Baldo, P.; Merkle, K.L.; Buchholz, D.B.; Mahajan, S.; Lei, J.S.; Markworth, P.R.; Chang, R.P.H.

    1996-12-01

    The mechanisms of the sputter-induced orientation change in YBa{sub 2}Cu{sub 3}O{sub 7{minus}x}(YBCO) films grown on MgO (001) substrates by pulsed organometallic beam epitaxy (POMBE) are investigated by x-ray diffraction. Rutherford backscatter spectroscopy (RBS), cross-section TEM (XTEM) and microanalysis. It is found that the W atom implantation concurring with the ion sputtering plays an important role in effecting the orientation change. This implantation changes the surface structure of the substrate and induces an intermediate layer in the initial growth of the YBCO film, which in turn acts as a template that induces the orientation change. It seems that the surface morphology change caused by ion sputtering has only a minor effect on the orientation change.

  6. Study of microstructure and electrical properties of bulk YBCO prepared by melt textured growth technique

    SciTech Connect

    Gonal, M. R.; Krishnan, Madangopal; Tewari, R.; Tyagi, A. K.; Gyore, A.; Vajda, I.

    2015-06-24

    Bulk YBCO components were prepared using Melt Texture Growth (MTG) technique. Components were fabricated using MTG by addition of Y{sub 2}BaCuO{sub 5} (Y211) and Ag to YBCO, which leads to improved grain size without affecting superconducting properties. Green compacts prepared by cold isostatic pressing were pre-sintered at 930°C before subjecting melt texturing. Cooling rates lower than 1 °C.h{sup −1} was used, in between (peritectic) temperature of about 995 and 1025°C, to obtain large grained components. Microstructure studies in details were carried out by Scanning Electron Microscope (SEM), Electron Probe Micro Analysis (EPMA), Orientation Imaging Microscope (OIM) and TEM correlated with electrical properties like Critical current density (J{sub c})

  7. Static Test for a Gravitational Force Coupled to Type 2 YBCO Superconductors

    NASA Technical Reports Server (NTRS)

    Li, Ning; Noever, David; Robertson, Tony; Koczor, Ron; Brantley, Whitt

    1997-01-01

    As a Bose condensate, superconductors provide novel conditions for revisiting previously proposed couplings between electromagnetism and gravity. Strong variations in Cooper pair density, large conductivity and low magnetic permeability define superconductive and degenerate condensates without the traditional density limits imposed by the Fermi energy (approx. 10(exp -6) g cc. Recent experiments have reported anomalous weight loss for a test mass suspended above a rotating type II, YBCO superconductor, with the percentage change (0.05 - 2.1 %) independent of the test mass' chemical composition and diamagnetic properties. A variation of 5 parts per 10' was reported above a stationary (non-rotating) superconductor. In experiments using a sensitive gravimeter, bulk YBCO superconductors were stably levitated in a DC magnetic field. Changes in acceleration were measured to be less than 2 parts in 108 of the normal gravitational acceleration. This result puts new limits on the strength and range of the proposed coupling between static superconductors and gravity.

  8. T /B scaling without quasiparticle mass divergence: YbCo2Ge4

    NASA Astrophysics Data System (ADS)

    Sakai, Akito; Kitagawa, Kentaro; Matsubayashi, Kazuyuki; Iwatani, Makoto; Gegenwart, Philipp

    2016-07-01

    YbCo2Ge4 is a clean paramagnetic Kondo lattice which displays non-Fermi-liquid behavior. We report a detailed investigation of the specific heat, magnetic Grüneisen parameter (Γmag), and temperature derivative of the magnetization (M ) on a high-quality single crystal at temperatures down to 0.1 K and magnetic fields up to 7 T. Γmag and d M /d T display a divergence upon cooling and obey T /B scaling. Similar behavior has previously been found in several other Yb-based Kondo lattices and related to a zero-field quantum critical point without fine tuning of pressure or composition. However, in the approach of B →0 the electronic heat capacity coefficient of YbCo2Ge4 saturates at low T , excluding ferromagnetic quantum criticality. This indicates that T /B scaling is insufficient to prove a zero-field quantum critical point.

  9. Versatility of metalorganic chemical vapor deposition process for fabrication of high quality YBCO superconducting thin films

    NASA Astrophysics Data System (ADS)

    Chern, C. S.; Kear, B. H.; Zhao, J.; Norris, P. E.; Li, Y. Q.

    1991-03-01

    YBCO films, having critical current densities in excess of 10 to the 6th A/sq cm at 77 K and transition temperatures of about 89 K, successfully deposited on close lattice matched substrate materials at substrate temperature in the range from 720 to 740 C, are presented. The critical current densities are 10,000 A/sq cm at 70 K and the critical temperatures are 82 K for the films deposited on sapphire substrates. Successful deposition of c-axis oriented YBCO films with a transition temperature of 85 K was also achieved on silver substrates. Detailed analyses of the films were carried out by X-ray diffraction, EDS, SEM, resistivity measurements, critical current density measurements, and magnetization susceptibility measurements.

  10. Hybrid quantum systems with YBCO coplanar resonators and spin ensembles of organic radicals

    NASA Astrophysics Data System (ADS)

    Ghirri, Alberto; Bonizzoni, Claudio; Troiani, Filippo; Cassinese, Antonio; D'Arienzo, Massimiliano; Beverina, Luca; Affronte, Marco

    We have studied the coherent coupling of microwave photons in a superconducting coplanar resonator with a spin ensemble of stable open-shell organic radicals. We fabricated YBCO/sapphire coplanar resonators that show quality factors ~= 3*104 at 1.8 K, that remain remarkably stable in high magnetic field applied parallel to the YBCO film [QL (7 T) = 90% QL (0 T)]. Spin ensembles of (3,5-Dichloro-4-pyridyl)bis(2,4,6-trichlorophenyl)methyl organic radical (PyBTM) show sharp EPR linewidth (8 MHz) due to the effect of the exchange narrowing. The frequency of the spin transition is tuned by means of the external magnetic field. We show the achievement of the strong collective coupling with the resonant photons with coupling rates exceeding 90 MHz at 1.8 K.

  11. Pinning features of the magnetic flux trapped by YBCO single crystals in weak constant magnetic fields

    NASA Astrophysics Data System (ADS)

    Monarkha, V. Yu.; Paschenko, V. A.; Timofeev, V. P.

    2013-02-01

    The dynamics of Abrikosov vortices and their bundles was experimentally investigated in weak constant magnetic fields, in the range of Earth's magnetic field. Characteristics of the isothermal magnetization relaxation in YBCO single-crystal samples with strong pinning centers were studied for different sample-field orientation. The obtained values of normalized relaxation rate S allowed us to estimate the effective pinning potential U in the bulk of the YBCO sample and its temperature dependence, as well as the critical current density Jc. A comparison between the data obtained and the results of similar measurements in significantly higher magnetic fields was performed. To compare different techniques for evaluation of Jc, the magnetization loop measurements M(H), which relate the loop width to the critical current, were carried out. These measurements provided important parameters of the samples under study (penetration field Hp and first critical field Hc1), which involve the geometrical configuration of the samples.

  12. Proximity effect induced by Kondo interaction in a network composed of YBCO and spin density wave

    NASA Astrophysics Data System (ADS)

    Maity, S.; Ghosh, Ajay Kumar

    2015-10-01

    The possibility of the proximity effect mediated by Kondo interaction in YBCO embedded in system of diluted magnetic spin ordering has been studied. An YBCO sample is selected in which both metal to insulator transition and superconducting state exist in the different ranges of temperature. The intergranular network of the bulk Y-123 has been modified by the inclusion of YMnO3 which has a well defined magnetic structure depending on temperature. The current-voltage measurements have been carried out in pure Y-123 at several temperatures. At the same set of temperatures the current-voltage curves in presence of YMnO3 have been studied. The role of the diluted spin magnetic ordering in tuning proximity effect and conduction property in binary systems is associated with reduced coherence length in the normal region.

  13. Epitaxial growth of YBCO films on metallic substrates buffered with yttria-stabilized zirconia

    NASA Astrophysics Data System (ADS)

    Ma, B.; Li, M.; Fisher, B. L.; Koritala, R. E.; Balachandran, U.

    2002-05-01

    Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on polished Hastelloy C (HC) substrates by ion-beam-assisted deposition (IBAD) and electron-beam evaporation. A water-cooled sample stage was used to dissipate heat generated by the Kaufman ion source and to maintain the substrate temperature below 100 °C during deposition. X-ray pole figures were used for texture analysis. In-plane texture measured from the YSZ (111) φ-scan full-width-at-half-maximum (FWHM) was 13.2° and out-of-plane texture from the YSZ (002) ω-scan FWHM was 7.7°. In-plane texture improved with lowered substrate temperature during IBAD deposition. RMS surface roughness of 3.3 nm was measured by atomic force microscopy. A thin CeO2 buffer layer (≈10 nm) was deposited to improve the lattice match between the YSZ and YBCO films and to enhance the biaxial alignment of YBCO films. YBCO films were epitaxially grown on IBAD-YSZ buffered HC substrates with and without CeO2 buffer layers by pulsed laser deposition (PLD). In-plane texture FWHMs of 12° and 9° were observed for CeO2 (111) and YBCO (103), respectively. Tc=90 K, with sharp transition, and Jc values of ≈2×106 A/cm2 at 77 K in zero field were observed on 0.5-μm-thick, 5-mm-wide, and 1-cm-long samples.

  14. Design of a Cryogen Free Cryo-flipper using a High Tc YBCO Film

    NASA Astrophysics Data System (ADS)

    Parnell, S. R.; Kaiser, H.; Washington, A. L.; Li, F.; Wang, T.; Baxter, D. V.; Pynn, R.

    It is well-known that the Meissner effect in superconducting materials can be used to provide a well-defined non- adiabatic magnetic field transition that can be utilised to produce an efficient white beam neutron spin flipper. Typically these devices utilise niobium and hence require continuous use of liquid helium in order to maintain the device tem- perature. The use of high Tc materials removes the need for cryogens and has been explored previously and shown to provide efficient flipping of the neutron spin. Improvements in thin high Tc films over the past few years make these materials even more attractive. Here we present a design using a 350-nm-thick YBCO film capped with 100 nm of gold on a 78 x 100 x 0.5 mm sapphire substrate (Theva, Germany). The apparatus is compact (200 mm in length along the neutron beam), consisting of an oxygen-free high-conductivity copper frame, which holds the YBCO film and is mounted to the cold finger of a closed-cycle refrigerator. The part of the vacuum chamber, where the YBCO film is located, is ≈ 50 mm wide, which allows us to minimise the distance from the film to the external magnets. This distance is 26 mm on each side. The details of the guide field design are also discussed. In this design, the maximum neutron beam size that can be used is 40 × 40 mm2 and we can easily switch from a vertical to a horizontal guide field on either side of the YBCO film.

  15. Enhancing critical current in YBCO thick films: Substrate decoration and quasi-superlattice approach

    NASA Astrophysics Data System (ADS)

    Sarkar, A.; Mikheenko, P.; Dang, V. S.; Abell, J. S.; Crisan, A.

    2009-10-01

    For power applications of superconducting films, the critical current density ( J c) and the thickness of the film ( d) should be as high as possible. Since J c decreases with both thickness and magnetic field, artificial pinning centres in addition to natural ones are required to keep J c high. The earliest cost-effective method used for introducing artificial pinning centres was the so-called substrate decoration, i.e., growing nano-scale islands (nano-dots) of certain materials on the substrate prior to the deposition of the superconducting thin film. Later on another version of this approach proved to be successful: building up a layered distribution of a second phase using a multilayer deposition (quasi-superlattices). Several materials have been used for the creation of artificial pinning centres. Here we report on the artificial pinning centres induced in YBCO thick films by substrate decoration and quasi-superlattice approaches using nano-dots of Pd and non-superconducting YBCO. The cross-sectional AFM images show evidence of c-axis correlated columnar defects. These defects significantly contribute to the pinning of magnetic flux and increase critical current in the films. We observed an important shift of the position of the maximum in the thickness dependence of J c( B) towards higher thicknesses compared with pure YBCO films by both approaches. A high J c( B) in our quite thick films provides a very high total critical current per cm of the film width. Critical current as high as 800 A/cm width was achieved in a 2.4 μm thick quasi-superlattice film with non-superconducting YBCO nano-dots.

  16. Flux pinning effect in a melt textured YBCO bulk evaluated by using tension measurements

    NASA Astrophysics Data System (ADS)

    Lee, Joon Ho; Ahmad, Dawood; Kim, Byoung Joo; Cha, Myoungsik; Yang, Ho Soon; Kim, Young Cheol; Ko, Rock Kil; Jeong, Dae Young

    2013-01-01

    Research on the flux pinning effect in type-II superconductors has usually been focused on microor nanosize pinning centers, and mm-sized pinning centers have been relatively less studied. In order to investigate the flux pinning effect caused by mm-sized pinning centers, we introduce a tension measurement method in this research. A cm-sized melt-textured YBCO bulk, in which holes with a 2 mm diameter are made, is prepared. The YBCO bulk is field-cooled by using a strong magnet in liquid nitrogen, and the bulk and the magnet are separated from each other. Then, an attractive force ( f a ) between them is generated, and f a is detected by using a tension measuring device. As the distance ( d) between them is increased, f a increases at short distance and decreases at long distance, showing a maximum value, f am , at a specific distance. The measurement of f a is stopped when d reaches a value defined as the breaking distance ( d bk ), as if a `string' between the magnet and the YBCO bulk is broken. As the number of holes ( n) made in the YBCO bulk increases from 1 to 6, f am and d bk increase, in spite of the superconducting volume loss. f am and d bk for n ≥ 7 converge to nearly constant values, which are smaller than the values for n = 6. This means that the critical current density can be calculated by using f am or d bk for a sufficient number of holes.

  17. Effect of Au nano-particles doping on polycrystalline YBCO high temperature superconductor

    NASA Astrophysics Data System (ADS)

    Dadras, Sedigheh; Gharehgazloo, Zahra

    2016-07-01

    In this research, we prepared different Au nanoparticles (0.1-2 wt%) doped YBCO high temperature superconductor samples by sol-gel method. To characterize the samples, we used X-Ray diffraction (XRD) and scanning electron microscope (SEM) analysis. Results show the formation of orthorhombic phase of superconductivity for all prepared samples. We observed that by adding Au nanoparticles, the grains' size of the samples reduces from 76 nm to 47 nm as well. The critical current density (Jc) and transition temperature (Tc) were determined using current versus voltage (I-V) and resistivity versus temperature (ρ-T) measurements, respectively. We found that by increasing Au nanoparticles in the compound, in comparison to the pure YBCO sample, the transition temperature, pinning energy and critical current density will increase. Also, the highest Jc is for 1 wt% Au doped YBCO compound that its critical current density is about 8 times more than the Jc of pure one in 0.7 T magnetic field.

  18. Bulk YBCO seeded with 45°-45° bridge-seeds of different lengths

    NASA Astrophysics Data System (ADS)

    Shi, Y.-H.; Durrell, J. H.; Dennis, A. R.; Cardwell, D. A.

    2013-01-01

    Single grain, (RE)BCO (rare earth-barium-copper oxide) bulk superconductors in large or complicated geometries are required for a variety of potential applications, such as in motors and generators and magnetic shielding devices. As a result, top, multi-seeded, melt growth has been investigated over the past 15 years in an attempt to enlarge the size of (RE)BCO single grains specifically for such applications. Of these multi-seeding techniques, so-called bridge-seeding provides the best alignment of two seeds in a single grain growth process. Here we report, for the first time, the successful growth of YBCO (yttrium-barium-copper oxide) using a special, 45°-45°, arrangement of bridge-seeds. The superconducting properties, including trapped field, of the multi-seeded YBCO grains have been measured for different bridge lengths of the 45°-45° bridge-seeds. The boundaries at the impinging growth front and the growth features of the top, multi-seeded surface and cross-section of the multi-seeded, samples have been analysed using optical microscopy. The results suggest that an impurity-free boundary between the two seeds of each leg of the bridge-seed can form when 45°-45° bridge-seeds are used to enlarge the size of YBCO grains.

  19. High Critical Current Coated Conductors

    SciTech Connect

    Paranthaman, M. P.; Selvamanickam, V.

    2011-12-27

    One of the important critical needs that came out of the DOE’s coated conductor workshop was to develop a high throughput and economic deposition process for YBCO. Metal-organic chemical vapor deposition (MOCVD) technique, the most critical steps in high technical micro fabrications, has been widely employed in semiconductor industry for various thin film growth. SuperPower has demonstrated that (Y,Gd)BCO films can be deposited rapid with world record performance. In addition to high critical current density with increased film thickness, flux pinning properties of REBCO films needs to be improved to meet the DOE requirements for various electric-power equipments. We have shown that doping with Zr can result in BZO nanocolumns, but at substantially reduced deposition rate. The primary purpose of this subtask is to develop high current density MOCVD-REBCO coated conductors based on the ion-beam assisted (IBAD)-MgO deposition process. Another purpose of this subtask is to investigate HTS conductor design optimization (maximize Je) with emphasis on stability and protection issues, and ac loss for REBCO coated conductors.

  20. The adipocyte-inducible secreted phospholipases PLA2G5 and PLA2G2E play distinct roles in obesity.

    PubMed

    Sato, Hiroyasu; Taketomi, Yoshitaka; Ushida, Ayako; Isogai, Yuki; Kojima, Takumi; Hirabayashi, Tetsuya; Miki, Yoshimi; Yamamoto, Kei; Nishito, Yasumasa; Kobayashi, Tetsuyuki; Ikeda, Kazutaka; Taguchi, Ryo; Hara, Shuntaro; Ida, Satoshi; Miyamoto, Yuji; Watanabe, Masayuki; Baba, Hideo; Miyata, Keishi; Oike, Yuichi; Gelb, Michael H; Murakami, Makoto

    2014-07-01

    Metabolic disorders, including obesity and insulin resistance, have their basis in dysregulated lipid metabolism and low-grade inflammation. In a microarray search of unique lipase-related genes whose expressions are associated with obesity, we found that two secreted phospholipase A2s (sPLA2s), PLA2G5 and PLA2G2E, were robustly induced in adipocytes of obese mice. Analyses of Pla2g5(-/-) and Pla2g2e(-/-) mice revealed distinct roles of these sPLA2s in diet-induced obesity. PLA2G5 hydrolyzed phosphatidylcholine in fat-overladen low-density lipoprotein to release unsaturated fatty acids, which prevented palmitate-induced M1 macrophage polarization. As such, PLA2G5 tipped the immune balance toward an M2 state, thereby counteracting adipose tissue inflammation, insulin resistance, hyperlipidemia, and obesity. PLA2G2E altered minor lipoprotein phospholipids, phosphatidylserine and phosphatidylethanolamine, and moderately facilitated lipid accumulation in adipose tissue and liver. Collectively, the identification of "metabolic sPLA2s" adds this gene family to a growing list of lipolytic enzymes that act as metabolic coordinators.

  1. Feasibility of a short-period superconducting undulator using 2G HTS tapes.

    SciTech Connect

    Kim, S. H.; Doose, C. L.; Jaski, M. S.; Kasa, M. T. )

    2011-06-01

    This paper presents a design concept of a planar-type superconducting undulator (SCU) using YBCO high-temperature superconductor (HTS) tapes. The SCU has a period length of 15 mm, and the tape conductor has dimensions of 4-mm width and 0.1-mm thickness. It has been shown that the conductor transition from one coil groove to the one in the next period is possible by making a semi-circular concave loop of the tape for continuous winding in the same direction. Non-uniform current distribution in the tape may cause field quality degradation. Assuming a uniform current density in the tape, the engineering critical-current density of the HTS in the coil for the design and the corresponding achievable on-axis peak field at 4.2 K were calculated.

  2. Orientations of Y 2BaCuO 5 and YBCO within melt-textured and directional solidified samples studied by EBSD

    NASA Astrophysics Data System (ADS)

    Koblischka, M. R.; Koblischka-Veneva, A.; Reddy, E. S.; Schmitz, G. J.; Ogasawara, K.; Murakami, M.

    2003-10-01

    By means of automated electron backscatter diffraction (EBSD) analysis, we studied the local orientations of embedded Y 2BaCuO 5 (2 1 1) particles within melt-textured YBCO samples, and also the orientations of embedded YBCO particles in directional solidified 211 samples. On both systems, we obtained high-quality Kikuchi patterns, allowing the automated mapping of the crystal orientations and a multi-phase analysis. In melt-textured YBCO with (0 0 1) orientation, we find that the embedded 211 particles do not have any preferred orientation, but the maps also reveal that at certain orientations of the 211 particles the YBCO growth is not altered. In directional solidified 211 samples, where the 211 is mainly oriented in (0 0 1) direction, the embedded YBCO particles show only some specific orientations.

  3. Electronic Properties of Layered Oxides:. Pulsed Laser Deposition of YBCO Films for In-Situ Studies by Photoemission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pavuna, D.; Ariosa, D.; Berger, H.; Christensen, S.; Frazer, B.; Gatt, R.; Grioni, M.; Margaritondo, G.; Misra, S.; Onellion, M.; Schmauder, T.; Vobornik, I.; Xi, X.; Zacchigna, M.; Zwick, F.

    Due to imperfect surfaces of most cuprate samples, almost all Photoemission studies in the past decade were performed on Bi2Sr2CaCu2O8+x, even though a large fraction of other studies and electronic applications was reported for YBa2Cu3O7-δ (YBCO) family of superconducting compounds. In order to systematically study the gap parameter and the Fermi surface variation in high symmetry directions of YBCO and related oxide films we have constructed a new facility at the Wisconsin Synchrotron Radiation Center. We use the pulsed laser ablation (PLD) system that is directly linked to the photoemission chamber. In our unique approach, the samples never leave the controlled ambient and we oxidize our films, either by molecular oxygen or by ozone. In this paper, we, summarize some of the most relevant recent results on electronic properties of layered oxides and describe our new facility for the study of YBCO and related oxide films.

  4. Synchronous Generator with HTS-2G field coils for Windmills with output power 1 MW

    NASA Astrophysics Data System (ADS)

    Kovalev, K.; Kovalev, L.; Poltavets, V.; Samsonovich, S.; Ilyasov, R.; Levin, A.; Surin, M.

    2014-05-01

    Nowadays synchronous generators for wind-mills are developed worldwide. The cost of the generator is determined by its size and weight. In this deal the implementation of HTS-2G generators is very perspective. The application of HTS 2G field coils in the rotor allows to reduce the size of the generator is 1.75 times. In this work the design 1 MW HTS-2G generator is considered. The designed 1 MW HTS-2G generator has the following parameters: rotor diameter 800 mm, active length 400 mm, phase voltage 690V, rotor speed 600 min-1 rotor field coils with HTS-2G tapes. HTS-2G field coils located in the rotating cryostat and cooled by liquid nitrogen. The simulation and optimization of HTS-2G field coils geometry allowed to increase feed DC current up to 50A. Copper stator windings are water cooled. Magnetic and electrical losses in 1 MW HTS-2G generator do not exceed 1.6% of the nominal output power. In the construction of HTS-2G generator the wave multiplier with ratio 1:40 is used. The latter allows to reduce the total mass of HTS-2G generator down to 1.5 tons. The small-scale model of HTS-2G generator with output power 50 kW was designed, manufactured and tested. The test results showed good agreement with calculation results. The manufacturing of 1 MW HTS-2G generator is planned in 2014. This work is done under support of Rosatom within the frames of Russian Project "Superconducting Industry".

  5. YBCO High-Temperature Superconducting Filters on M-Plane Sapphire Substrates

    NASA Technical Reports Server (NTRS)

    Sabataitis, J. C.; Mueller, C. H.; Miranda, F. A.; Warner, J.; Bhasin, K. B.

    1996-01-01

    Since the discovery of High Temperature Superconductors (HTS) in 1986, microwave circuits have been demonstrated using HTS films on various substrates. These HTS-based circuits have proven to operate with less power loss than their metallic film counterparts at 77 K. This translates into smaller and lighter microwave circuits for space communication systems such as multiplexer filter banks. High quality HTS films have conventionally been deposited on lanthanum aluminate (LaAlO3) substrates. However, LaAlO3 has a relative dielectric constant (epsilon(sub r)) of 24. With a epsilon(sub r) approx. 9.4-11.6, sapphire (Al2O3) would be a preferable substrate for the fabrication of HTS-based components since the lower dielectric constant would permit wider microstrip lines to be used in filter design, since the lower dielectric constant would permit wider microstrip lines to be used for a given characteristic impedance (Z(sub 0)), thus lowering the insertion losses and increasing the power handling capabilities of the devices. We report on the fabrication and characterization of YBa2Cu3O(7-delta) (YBCO) on M-plane sapphire bandpass filters at 4.0 GHz. For a YBCO 'hairpin' filter, a minimum insertion loss of 0.5 dB was measured at 77 K as compared with 1.4 dB for its gold counterpart. In an 'edge-coupled' configuration, the insertion loss went down from 0.9 dB for the gold film to 0.8 dB for the YBCO film at the same temperature.

  6. Microstructure of artificial 45{sup degree} [001] tilt grain boundaries in YBCO films grown on (001) MgO

    SciTech Connect

    Huang, Y.; Vuchic, B.V.; Merkle, K.L.; Buchholz, D.B.; Chang, R.P.H.

    1996-03-01

    High-angle grain boundaries in YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) show weak-link effects and behave as Josephson junctions. This kind of grain boundary junction (GBJs) has potential applications in magnetic field measurement and electronic devices. This work studies the microstructure of artificially made GBJs in YBCO films on (001) MgO and the mechanism of boundary formation, with the goal to improve GBJ quality and obtain a better understanding of the junctions` transport properties.

  7. Centre seeded infiltration and growth process for fabrication of large grain bulk YBCO/Ag superconducting composites

    NASA Astrophysics Data System (ADS)

    Parthasarathy, R.; Seshubai, V.

    2012-06-01

    We report the fabrication of a large grain bulk YBCO/Ag superconductor using a novel technique which we call Centre Seeded Infiltration and Growth Process (CSIGP). Using this technique, it has been made possible to get bulk YBCO/Ag composite sample with uniform grain growth textured along the c-axis. The resulting large grain sample has been found to have high critical current densities up to large magnetic fields. We correlate the improved superconducting and magnetic properties to the modified grain growth conditions employed in this fabrication technique.

  8. The peculiarities of local structure of YbNi2 and YbCo2 intermetallics synthesized at high pressure.

    NASA Astrophysics Data System (ADS)

    Chernysheva, O. V.; Menushenkov, A. P.; Tsvyashchenko, A. V.; Fomicheva, L. N.; Ivanov, A. A.; Kuznetsov, A. V.

    2016-09-01

    Local structure of YbCo2 and YbNi2 was investigated by EXAFS and XANES spectroscopy. It was found that the bond Yb-Co(Ni) has the highest static disorder and its length increases with temperature decrease, while all other bonds remain almost unchanged. This phenomenon may be caused by short-range magnetic ordering at temperatures above the phase transition. XANES measurements above ZIII-Yb absorption edge in YbCo2 and YbNi2 revealed that both compounds have almost the same density of free 5d-states

  9. Much simplified ion-beam assisted deposition-TiN template for high-performance coated conductors

    NASA Astrophysics Data System (ADS)

    Xiong, J.; Matias, V.; Wang, H.; Zhai, J. Y.; Maiorov, B.; Trugman, D.; Tao, B. W.; Li, Y. R.; Jia, Q. X.

    2010-10-01

    A much simplified template, i.e., two nonsuperconducting layers between the superconducting YBa2Cu3O7-δ (YBCO) and the polycrystalline metal substrate, has been developed for high-performance coated conductors by using biaxially aligned TiN as a seed layer. A combination of a thin TiN (˜10 nm by ion-beam assisted deposition) layer and an epitaxial buffer LaMnO3 layer (˜120 nm) allows us to grow epitaxial YBCO films with values of full width at half-maximum around 3.5° and 1.7° for the ϕ-scan of (103) and rocking curve of (005) YBCO, respectively. The YBCO films grown on electropolished polycrystalline Hastelloy using this two-layer template exhibited a superconducting transition temperature of 89.5 K, a critical current density of 1.2 MA/cm2 at 75.5 K, and an α value (proportional factor of critical current density Jc˜H-α) of around 0.33, indicating a high density of pinning centers and an absence of weak links.

  10. Performance of a polarised neutron cryo-flipper using a high TcYBCO film

    NASA Astrophysics Data System (ADS)

    Parnell, S. R.; Washington, A. L.; Kaiser, H.; Li, F.; Wang, T.; Hamilton, W. A.; Baxter, D. V.; Pynn, R.

    2013-09-01

    It is well-known that the Meissner effect in superconducting materials can be used to provide a well-defined, non-adiabatic, magnetic-field transition. This can be utilised to produce a highly efficient neutron spin flipper that is suitable for use with neutrons of multiple wavelengths. Devices of this type using superconducting niobium have been deployed on neutron diffractometers for several decades but have required liquid helium to maintain the correct temperature. The use of high Tc materials, which removes the need for cryogens and simplifies the device, was first explored by Fitzsimmons et al. in [1]. In this communication, we describe a π flipper which uses commercially available films consisting of a 350-nm-thick YBCO film capped with 100 nm of gold on a 78×100×0.5 mm sapphire substrate. We discuss the design and performance of this device. The apparatus is compact (≈200 mm in length along the neutron beam), consisting of an oxygen-free high-conductivity copper frame, which holds the YBCO film and is mounted to the cold finger of a closed-cycle He refrigerator. The part of the vacuum chamber, where the YBCO film is located, is 5 cm wide, which allows us to minimise the distance from the film to the magnetic guide fields. Negligible small angle neutron scattering is observed from the flipper and its transmission is measured to be greater than 98.5% over a wide band of neutron wavelengths. In this design, the maximum neutron beam size that can be used is 42×42 mm2 and we can easily switch from a vertical to a horizontal guide field (both perpendicular to the neutron beam) on either side of the YBCO film. Data are reported for neutron wavelengths between 4 and 8.5 Å and flipping efficiencies under a variety of conditions are discussed. Under optimum conditions an efficiency of 99.5±0.3% was achieved for 4-8 Å neutrons on a pulsed source and 99.4±0.5% was achieved at a monochromatic source using a neutron wavelength of 4.2 Å.

  11. Direct observation of surface plasmons in YBCO by attenuated total reflection of light in the infrared

    NASA Astrophysics Data System (ADS)

    Walmsley, D. G.; Smyth, C. C.; Sellai, A.; McCafferty, P. G.; Dawson, P.; Morrow, T.; Graham, W. G.

    1994-02-01

    Surface plasmons have been observed directly in YBCO films in an Otto-geometry attenuated total reflection measurement at a wavelength of 3.392 μm. The laser deposited films are c-axis oriented on an MgO substrate. This observation confirms theoretical deductions from complex dielectric function data. Measured data have been fitted to a theoretical model and are compared with the optical constants determined by Bozovic [1]. The investigations have been extended to films with other orientations to investigate whether material anisotropy is reflected in the results and non-metallic behaviour is found.

  12. Co-doping effects of Gd and Ag on YBCO films derived by metalorganic deposition

    NASA Astrophysics Data System (ADS)

    Sun, Meijuan; Liu, Zhiyong; Bai, Chuanyi; Guo, Yanqun; Lu, Yuming; Fan, Feng; Cai, Chuanbing

    2015-12-01

    Y1-xGdxBa2Cu3O7-δ-Ag (x = 0, 0.25, 0.5, 0.75, 1) thin films were prepared on oxide buffered Hastelloy substrates by low fluorine metalorganic depostion (MOD) process. The effects of co-doping of Ag and Gd on the microstructures and superconducting properties of YBCO thin films are investigated with respect to improvement on texture and superconducting performance in case of optimized doping content. It is found that optimum addition of Ag and Gd may lead to better c-axis orientation, superior surface microstructure and finally give rise to much improvement of superconducting performance.

  13. Switching of YBCO thin films into the dissipative state at high current densities

    NASA Astrophysics Data System (ADS)

    Villard, Catherine; Devismes, Marie-Françoise; Carbone, Laurent; Bourgault, Daniel

    We report on the switching properties at high current densities of YBCO thin films shunted by an Ag layer. These experiments are performed either in liquid nitrogen or liquid argon (87.3K). Different transition regimes associated to specific electric field thresholds are observed. The nature of the thermal exchange with the bath and the role of the silver shunt and substrate are discussed. While only two regimes in the current-voltage characteristics are observed in liquid nitrogen, successively reversible and hysteretic, an intermediate behaviour appears at 87.3K associated with a total current diversion by the silver layer.

  14. Study on Quench Protection of Coil Wound of Copper or Silver Stabilized YBCO Conductors

    NASA Astrophysics Data System (ADS)

    Tsukamoto, O.; Fu, Y.; Yoshida, H.; Furuse, M.

    2004-06-01

    We investigated necessary amount of copper or silver stabilizer added to YBCO conductor by numerical calculation to protect the conductor in a coil of dry windings from damages caused by quenches. The coil is assumed to be operated at 20K, 40K and 77K and hot-spot temperature of the conductor during energy dump sequence is calculated. The necessary amount of the stabilizer and overall conductor current density of the conductor including the stabilizer were calculated to suppress the hot spot temperature below a certain threshold depending on the operation temperature.

  15. Fabrication and test of short helical solenoid model based on YBCO tape

    SciTech Connect

    Yu, M.; Lombardo, V.; Lopes, M.L.; Turrioni, D.; Zlobin, A.V.; Flanagan, G.; Johnson, R.P.; /MUONS Inc., Batavia

    2011-03-01

    A helical cooling channel (HCC) is a new technique proposed for six-dimensional (6D) cooling of muon beams. To achieve the optimal cooling rate, the high field section of HCC need to be developed, which suggests using High Temperature Superconductors (HTS). This paper updates the parameters of a YBCO based helical solenoid (HS) model, describes the fabrication of HS segments (double-pancake units) and the assembly of six-coil short HS model with two dummy cavity insertions. Three HS segments and the six-coil short model were tested. The results are presented and discussed.

  16. Semifluorinated Alkylphosphonic Acids Form High-Quality Self-Assembled Monolayers on Ag-Coated Yttrium Barium Copper Oxide Tapes and Enable Filamentization of the Tapes by Microcontact Printing.

    PubMed

    Park, Chul Soon; Lee, Han Ju; Lee, Dahye; Jamison, Andrew C; Galstyan, Eduard; Zagozdzon-Wosik, Wanda; Freyhardt, Herbert C; Jacobson, Allan J; Lee, T Randall

    2016-08-30

    A custom-designed semifluorinated phosphonic acid, (9,9,10,10,11,11,12,12,13,13,14,14,15,15,16,16,16-heptadecafluorohexadecyl)phosphonic acid (F8H8PA), and a normal hexadecylphosphonic acid (H16PA) were synthesized and used to generate self-assembled monolayers (SAMs) on commercially available yttrium barium copper oxide (YBCO) tapes. In this study, we wished to evaluate the effectiveness of these monolayer films as coatings for selectively etching YBCO. Initial films formed by solution deposition and manual stamping using a non-patterned polydimethylsiloxane stamp allowed for a comparison of the film-formation characteristics. The resulting monolayers were characterized by X-ray photoelectron spectroscopy (XPS), contact angle goniometry, and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS). To prepare line-patterned (filamentized) YBCO tapes, standard microcontact printing (μ-CP) procedures were used. The stamped patterns on the YBCO tapes were characterized by scanning electron microscopy (SEM) before and after etching to confirm the effectiveness of the patterning process on the YBCO surface and energy-dispersive X-ray spectroscopy (EDX) to obtain the atomic composition of the exposed interface. PMID:27482760

  17. 77 FR 61279 - Approval and Promulgation of Implementation Plans; Mississippi; 110(a)(2)(G) Infrastructure...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-09

    ...) Infrastructure Requirement for the 1997 and 2006 Fine Particulate Matter National Ambient Air Quality Standards... ``110(a)(2)(G) Infrastructure Requirement for the 1997 and 2006 Fine Particulate Matter National Ambient... section 110(a)(2)(G), of the CAA for both the 1997 and 2006 fine particulate matter (PM 2.5 )...

  18. WELLTON GOVERNMENT CAMP, PERMANENT GARAGE TYPE 2G. PLAN, ELEVATIONS, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    WELLTON GOVERNMENT CAMP, PERMANENT GARAGE TYPE 2-G. PLAN, ELEVATIONS, AND SECTIONS. Drawing 50-308-4553, dated October 21, 1949. U.S. Department of the Interior, Bureau of Reclamation, Yuma, Arizona - Wellton-Mohawk Irrigation System, Permanent Garage Type 2-G, 30611 and 30621 Wellton-Mohawk Drive, Wellton, Yuma County, AZ

  19. Preparation of YBCO single-crystal surfaces for angularly resolved planar tunneling studies

    NASA Astrophysics Data System (ADS)

    Lussier, Benoit; Charalambous, M.; Guillou, H.; Chaussy, J.; Lejay, P.; Pissas, M.

    1998-03-01

    For BCS superconductors, tunneling has proven to be a valuable tool. Indeed, using multiple recrystallisation techniques, planar junctions could be prepared along various crystalline directions enabling a direct mapping of the superconducting gap. For various reasons, such techniques are difficult (if not impossible) to apply to high-Tc materials. Furthermore, due to the small thickness of the single crystals, very few planar tunneling results into the basal plane are availlable. We present a new sample preparation technique which enables us to prepare surfaces for planar tunneling in any direction in the basal plane. After proper orientation of the high-Tc single crystal, the surface is mechanically polished using fine diamond paste. Such process routinely yields samples with rms surface roughness as low as 15ÅThe sample is then ion-polished with normal incidence xenon atoms and the tunneling barrier and counter-electrode are evaporated in-situ. Preliminary tunneling results for Au/YBCO and Nb/YBCO will be presented for twinned single crystals with tunneling in the (100) and (110) directions.

  20. Transport AC loss characteristics of a nine strand YBCO Roebel cable

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenan; Badcock, R. A.; Long, N. J.; Staines, Mike; Thakur, K. P.; Lakshmi, L. S.; Wright, A.; Hamilton, K.; Sidorov, G. N.; Buckley, R. G.; Amemiya, Naoyuki; Caplin, A. D.

    2010-02-01

    Transport AC loss in a short length of 9/2 YBCO Roebel cable (nine 2 mm wide strands) is measured. The AC loss data are compared with those in a 5/2 YBCO Roebel cable (five 2 mm wide strands) as well as that in a single strand. All the strands composing the cables and the single strand are insulated and cut from the same stock material. The validity of the measurement method was reconfirmed by results at a range of frequencies. At a wide range of It/Ic, the normalized AC losses in the Roebel cable were around 6.2-6.7 times of those in the single strand. This is less than the nine times predicted for a tight bundle of nine conductors. The normalized transport AC losses in the 5/2 Roebel cable are much smaller than those in the 9/2 Roebel. This should be due to larger superposition of magnetic field in the 9/2 Roebel. The Ic of the 9/2 and 5/2 Roebel cables is determined by serial connection of the strands. This eliminates the effect where differing resistances in the current terminations cause uneven current sharing between strands when the strands are connected in parallel.

  1. Test Status for Proposed Coupling of a Gravitational Force to Extreme Type II YBCO Ceramic Superconductors

    NASA Technical Reports Server (NTRS)

    Noever, David; Li, Ning; Robertson, Tony; Koczor, Ron; Brantley, Whitt

    1999-01-01

    As a Bose condensate, superconductors provide novel conditions for revisiting previously proposed couplings between electromagnetism and gravity. Strong variations in Cooper pair electron density, large conductivity and low magnetic permeability define superconductive and degenerate condensates without the traditional density limits imposed by the Fermi energy (about 10-6 g/cu cm). Recent experiments have reported anomalous weight loss for a test mass suspended above a rotating Type II, YBCO superconductor, with the percentage change (0.05-2.1%) independent of the test mass' chemical composition and diamagnetic properties. A variation of 5 parts per 10(exp 4) was reported above a stationary (non-rotating) superconductor. In the present experiments reported using a sensitive gravimeter (resolution <10(exp -9) unit gravity or variation of 10(exp -6) cm/sq s in accelerations), bulk YBCO superconductors were stably levitated in a DC magnetic field (0.6 Tesla) subject to lateral AC fields (60 Gauss at 60 Hz) and rotation. With magnetic shielding, thermal control and buoyancy compensation, changes in acceleration were measured to be less than 2 parts in 10(exp 8) of the normal gravitational acceleration. This result puts new limits on the strength and range of the proposed coupling between high-Tc superconductors and gravity. Latest test results will be reported, along with status for future improvements and prospects.

  2. Position-dependent texture analysis of melt-textured YBCO by means of electron backscatter diffraction

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Ogasawara, K.; Murakami, M.

    2003-10-01

    The texture and phase distribution of melt-textured YBa 2Cu 3O x (YBCO) was studied by means of automated electron backscatter diffraction (EBSD) analysis as a function of the position in the bulk pellet of 4 cm diameter. A total of five samples was cut from the pellet; four samples from the surface of the bulk with different distances to the seed crystal, and one cut in vertical direction in the middle of the pellet. The melt-textured YBCO samples require a two-phase analysis to be performed, so a high surface quality is necessary to enable an automated EBSD scan. Good quality Kikuchi patterns are obtained from both the 1 2 3 and 2 1 1 phases. We found an inhomogeneous distribution of the 2 1 1 particles. Whereas the samples cut from the surface contain a large amount of 2 1 1 particles, in the samples of the vertical direction only traces of 2 1 1 particles are found. Furthermore, we measured the misorientation angle distribution of all samples. The data are presented in form of phase mappings, misorientation distribution functions and pole figures.

  3. The influence of magnetic nano metal oxides doping on structure and electrical properties of YBCO superconductor

    NASA Astrophysics Data System (ADS)

    Salama, A. H.; El-Hofy, M.; Rammah, Y. S.; Elkhatib, M.

    2016-03-01

    Superconductor samples of YBa2Cu3O7-δ (YBCO) + x where x = 0.1, 0.2, 0.3, 0.4 and 0.5 wt% of nano metal oxides namely Cr2O3, Co3O4 and Mn3O4 namely are synthesized by the solid-state reaction route. Both x-ray diffraction and electron microscopy have been employed to study the phase identification and the microstructure of these samples. Transition temperature of the samples has been determined by four probe resistivity measurements. The x-ray diffraction patterns indicate that the gross structure of YBCO does not change with the substitution of three types of nano metal oxides with different doping level. The critical transition temperature (Tc) is found to decrease with the increases of doping level. Mn3O4 has highest Tc value which may be due to flux pinning from some defects and the rapid suppression in Tc with increasing concentration of Mn3O4 may be due to the cooper pair breaking and the hole filling in the CuO2 planes.

  4. Microstructural, transport, and RF properties of multilayer-deposited YBCO films

    NASA Astrophysics Data System (ADS)

    Madhavrao, L. R.; Track, E. K.; Drake, R. E.; Patt, R.; Hohenwarter, G. K. G.

    1991-03-01

    Thin films of Y1Ba2Cu3O(7-x) (YBCO) have been fabricated by sequential multilayer RF magnetron sputter-deposition from Y2O3, BaCo3, and CuO targets and postannealing in oxygen. This approach readily allows precise control of the film stoichiometry and is promising for applications that require deposition over large areas. Films on different substrates-including SrTiO3, LaAlO3, MgO and sapphire-are found to be c-axis oriented for film thicknesses between 300 A and 10,000 A. Transport current densities in the range of 106 A/sq cm are obtained on SrTiO3 and LaAlO3 substrates and in the range of 105 A/sq cm on MgO and sapphire. Transition temperatures of 89 K (resistive) and 87 K (inductive) are obtained repeatably with LaAlO3 substrates. Copper cavity end wall measurements at 77 K and 35.6 GHz set an upper limit for the surface resistance of the YBCO films on LaAlO3 that is equal to the surface resistance of high-quality silver films. The fabrication and properties of these films are discussed.

  5. YBCO grain boundary Josephson junction coupled with a slot dipole antenna for terahertz wave detectors

    NASA Astrophysics Data System (ADS)

    Yamada, H.; Hayasaka, T.; Toya, G.; Saito, A.; Ohshima, S.; Nakajima, K.

    2014-05-01

    We examined terahertz wave detectors that used YBa2Cu3O7-δ (YBCO) grain boundary Josephson junctions (GBJJs) coupled with a slot dipole antenna (SDA). The detectors consisted of a 220-GHz full-wavelength SDA patterned on a Au layer and a GBJJ patterned on an YBCO/bicrystal MgO film, which were separated by an insulating benzocyclobutene layer. The microbridge of the fabricated junction was 5-μm wide and was trimmed to 2 μm using an ultraviolet laser cutter to modify the junction parameters. The critical current IC, normal resistance RN, and ICRN product after the trimming at 30 K were 0.62 mA, 1.42 Ω, and 0.88 mV, respectively. The current-voltage characteristics and radio frequency (RF) wave responses of these detectors for a millimeter wave of 180-240 GHz were measured at 30 K. The coupling efficiency between the GBJJ and the SDA and the system sensitivity were obtained as -19.0 dB and 630 V/W, respectively, at 193 GHz. For the RF wave response of 180-240 GHz, the coupling efficiency was relatively flat.

  6. Influence of Both Cooling Rate and TeO2 Addition on the Properties of YBCO Superconductor

    NASA Astrophysics Data System (ADS)

    Ahmed, Yasser Momtaz Zaki; Hassan, Mervat Said; Abd-Elatif, Hassan

    2016-08-01

    Composite of superconducting system YBCO-TeO2 was synthesized utilizing solid-state reaction technique. Different weight percentages of TeO2 were mixed with a basic mixture [YBCO] for the synthesis of [YBa2Cu3O7-y ]1-x (TeO2) x composites. These mixtures were sintered at 1213 K (940 °C) for 24 hours and the samples cooled down by two different ways. The first way carried out via slowly cooling in furnace with the rate of 274 K/min to 275 K/min (1 °C/min to 2 °C/min) and the second one is quenching in oxygen gas. The XRD analysis showed that YBCO orthorhombic phase is the major phase appeared in all samples with different TeO2 content regardless of the cooling way. Additionally, minor unknown secondary phases appeared and enlarged with increasing TeO2 addition. Although quenched samples showed a phase difference between the sample's outer surface (orthorhombic) and its interior (tetragonal), the slowly cooled one did not clearly show such distinction. Moreover, doping YBCO with TeO2 leads to increase in the sample bulk density and reduction in their degradation degree in the wet atmosphere.

  7. In-plane aligned YBCO film on textured YSZ buffer layer deposited on NiCr alloy tape by laser ablation with only O+ ion beam assistance

    NASA Astrophysics Data System (ADS)

    Tang Huang, Xin; Qing Wang, You; Wang, Qiu Liang; Chen, Qing Ming

    2000-02-01

    High critical current density and in-plane aligned YBa2 Cu3 O7-x (YBCO) film on a textured yttria-stabilized zirconia (YSZ) buffer layer deposited on NiCr alloy (Hastelloy c-275) tape by laser ablation with only O+ ion beam assistance was fabricated. The values of the x-ray phi-scan full width at half-maximum (FWHM) for YSZ(202) and YBCO(103) are 18° and 11°, respectively. The critical current density of YBCO film is 7.9 × 105 A cm-2 at liquid nitrogen temperature and zero field, and its critical temperature is 90 K.

  8. Aluminide coatings

    SciTech Connect

    Henager, Jr; Charles, H; Shin, Yongsoon; Samuels, William D

    2009-08-18

    Disclosed herein are aluminide coatings. In one embodiment coatings are used as a barrier coating to protect a metal substrate, such as a steel or a superalloy, from various chemical environments, including oxidizing, reducing and/or sulfidizing conditions. In addition, the disclosed coatings can be used, for example, to prevent the substantial diffusion of various elements, such as chromium, at elevated service temperatures. Related methods for preparing protective coatings on metal substrates are also described.

  9. COATED ALLOYS

    DOEpatents

    Harman, C.G.; O'Bannon, L.S.

    1958-07-15

    A coating is described for iron group metals and alloys, that is particularly suitable for use with nickel containing alloys. The coating is glassy in nature and consists of a mixture containing an alkali metal oxide, strontium oxide, and silicon oxide. When the glass coated nickel base metal is"fired'' at less than the melting point of the coating, it appears the nlckel diffuses into the vitreous coating, thus providing a closely adherent and protective cladding.

  10. 19. INTERIOR, 'CHILLER NO. 2' (G.S.A. PHOTOCOPY, N.D.) (4 x ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. INTERIOR, 'CHILLER NO. 2' (G.S.A. PHOTOCOPY, N.D.) (4 x 5 NEGATIVE) - U.S. General Services Administration, Central Heating Plant, C & D Streets between Twelfth & Thirteenth Streets Southwest, Washington, District of Columbia, DC

  11. Encouraging vehicle-to-grid (V2G) participation through premium tariff rates

    NASA Astrophysics Data System (ADS)

    Richardson, David B.

    2013-12-01

    The provision of vehicle-to-grid (V2G) services to an electric grid by electric vehicles (EVs) can potentially reduce the cost of vehicle ownership through revenue generation. Recent studies indicate that yearly vehicle profit from V2G may not be sufficient to induce widespread participation. This paper investigates the feasibility of a premium tariff rate for V2G power, similar to current feed-in-tariff (FIT) programs for renewable energy. Using Ontario, Canada as a case study, an hourly time-series model for a fleet of commuter EVs is created. Tariff rates for V2G peak power are calculated based on the same return on investment as the current FIT for renewable energy in Ontario. The tariff rates are competitive with the renewable energy tariffs, especially when EVs are allowed to provide ancillary services to the grid in addition to peak power. Despite the guaranteed rate of return, yearly vehicle profit is low. Two variations are considered to increase vehicle profit, thereby enhancing the attractiveness of V2G. A higher return on investment is favored over direct benefits offered to EV owners. A higher return on investment may be justifiable based on the higher level of risk inherent in V2G when compared to renewable energy.

  12. The HABP2 G534E polymorphism does not increase nonmedullary thyroid cancer risk in Hispanics

    PubMed Central

    Bohórquez, Mabel E; Estrada, Ana P; Stultz, Jacob; Sahasrabudhe, Ruta; Williamson, John; Lott, Paul; Duque, Carlos S; Donado, Jorge; Mateus, Gilbert; Bolaños, Fernando; Vélez, Alejandro; Echeverry, Magdalena

    2016-01-01

    Familial nonmedullary thyroid cancer (NMTC) has not been clearly linked to causal germline variants, despite the large role that genetic factors play in risk. Recently, HABP2 G534E (rs7080536A) has been implicated as a causal variant in NMTC. We have previously shown that the HABP2 G534E variant is not associated with TC risk in patients from the British Isles. Hispanics are the largest and the youngest minority in the United States and NMTC is now the second most common malignancy in women from this population. In order to determine if the HABP2 G534E variant played a role in NMTC risk among Hispanic populations, we analyzed 281 cases and 1105 population-matched controls from a multicenter study in Colombia, evaluating the association through logistic regression. We found that the HABP2 G534E variant was not significantly associated with NMTC risk (P=0.843) in this Hispanic group. We also stratified available clinical data by multiple available clinicopathological variables and further analyzed the effect of HABP2 on NMTC presentation. However, we failed to detect associations between HABP2 G534E and NMTC risk, regardless of disease presentation (P≥0.273 for all cases). Therefore, without any significant associations between the HABP2 G534E variant and NMTC risk, we conclude that the variant is not causal of NMTC in this Hispanic population. PMID:27097599

  13. The HABP2 G534E polymorphism does not increase nonmedullary thyroid cancer risk in Hispanics.

    PubMed

    Bohórquez, Mabel E; Estrada, Ana P; Stultz, Jacob; Sahasrabudhe, Ruta; Williamson, John; Lott, Paul; Duque, Carlos S; Donado, Jorge; Mateus, Gilbert; Bolaños, Fernando; Vélez, Alejandro; Echeverry, Magdalena; Carvajal-Carmona, Luis G

    2016-05-01

    Familial nonmedullary thyroid cancer (NMTC) has not been clearly linked to causal germline variants, despite the large role that genetic factors play in risk. Recently, HABP2 G534E (rs7080536A) has been implicated as a causal variant in NMTC. We have previously shown that the HABP2 G534E variant is not associated with TC risk in patients from the British Isles. Hispanics are the largest and the youngest minority in the United States and NMTC is now the second most common malignancy in women from this population. In order to determine if the HABP2 G534E variant played a role in NMTC risk among Hispanic populations, we analyzed 281 cases and 1105 population-matched controls from a multicenter study in Colombia, evaluating the association through logistic regression. We found that the HABP2 G534E variant was not significantly associated with NMTC risk (P=0.843) in this Hispanic group. We also stratified available clinical data by multiple available clinicopathological variables and further analyzed the effect of HABP2 on NMTC presentation. However, we failed to detect associations between HABP2 G534E and NMTC risk, regardless of disease presentation (P≥0.273 for all cases). Therefore, without any significant associations between the HABP2 G534E variant and NMTC risk, we conclude that the variant is not causal of NMTC in this Hispanic population. PMID:27097599

  14. Coated conductors

    DOEpatents

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

    2010-06-15

    Articles are provided including a base substrate having a layer of an IBAD oriented material thereon, and, a layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the layer of an IBAD oriented material. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates.

  15. Recycling failed bulk YBCO superconductors using the NdBCO/YBCO/MgO film-seeded top-seeded melt growth method

    NASA Astrophysics Data System (ADS)

    Xu, H. H.; Cheng, L.; Yan, S. B.; Yu, D. J.; Guo, L. S.; Yao, X.

    2012-05-01

    REBa2Cu3Oy (RE123 or REBCO, RE = rare earth elements) bulk high-temperature superconductors have a potential perspective for large-scale engineering applications. However, the cost of REBCO bulk production is rather high, considering high failure rates, expensive RE materials, and Pt or Ag addition. Using the cold-seeding in the top-seeded melt growth, a simple and feasible process, we succeeded in recycling the failed REBCO (RE = Y) bulks. The distinctive feature of this recycling process is the use of YBCO-buffered NdBCO films as seeds, which have high thermal stability and can endure a maximum processing temperature (Tmax) up to 1120 °C to enable full decomposition of solid REBCO. Three typical microstructures were recognized in the failed samples attributed to the inherent differences in the non-optimized growth heating profiles. Preferential recycling procedures were chosen according to the difficulty of the failed-samples decomposition, which has a certain connection with the microstructures of the failed bulks. Finally, after oxygenation, the recycled bulks demonstrate good superconducting properties.

  16. Syndrome to gene (S2G): in-silico identification of candidate genes for human diseases.

    PubMed

    Gefen, Avitan; Cohen, Raphael; Birk, Ohad S

    2010-03-01

    The identification of genomic loci associated with human genetic syndromes has been significantly facilitated through the generation of high density SNP arrays. However, optimal selection of candidate genes from within such loci is still a tedious labor-intensive bottleneck. Syndrome to Gene (S2G) is based on novel algorithms which allow an efficient search for candidate genes in a genomic locus, using known genes whose defects cause phenotypically similar syndromes. S2G (http://fohs.bgu.ac.il/s2g/index.html) includes two components: a phenotype Online Mendelian Inheritance in Man (OMIM)-based search engine that alleviates many of the problems in the existing OMIM search engine (negation phrases, overlapping terms, etc.). The second component is a gene prioritizing engine that uses a novel algorithm to integrate information from 18 databases. When the detailed phenotype of a syndrome is inserted to the web-based software, S2G offers a complete improved search of the OMIM database for similar syndromes. The software then prioritizes a list of genes from within a genomic locus, based on their association with genes whose defects are known to underlie similar clinical syndromes. We demonstrate that in all 30 cases of novel disease genes identified in the past year, the disease gene was within the top 20% of candidate genes predicted by S2G, and in most cases--within the top 10%. Thus, S2G provides clinicians with an efficient tool for diagnosis and researchers with a candidate gene prediction tool based on phenotypic data and a wide range of gene data resources. S2G can also serve in studies of polygenic diseases, and in finding interacting molecules for any gene of choice.

  17. Calibration of Hall sensor array for critical current measurement of YBCO tape with ferromagnetic substrate

    NASA Astrophysics Data System (ADS)

    Zhu, Yunpeng; Wang, Gang; Liu, Liyuan; Yang, Xinsheng; Zhao, Yong

    2015-12-01

    HAS (Hall sensor array) is a powerful tool to detect the uniformity of HTS (high temperature superconductor) tape through mapping the distribution of remanent or shielding field along the surface of the tape. However, measurement of HTS tape with ferromagnetic parts by HSA is still an issue because the ferromagnetic substrate has influence on the magnetic field around the HTS layer. In this work, a continuous HSA system has been designed to measure the critical current of the YBCO tape with ferromagnetic substrate. The relationship between the remanent field and critical current was calibrated by the finite element method. The result showed that the HSA is an effective method for evaluating the critical current of the HTS tape with ferromagnetic substrate.

  18. 2D SQIF arrays using 20 000 YBCO high R n Josephson junctions

    NASA Astrophysics Data System (ADS)

    Mitchell, E. E.; Hannam, K. E.; Lazar, J.; Leslie, K. E.; Lewis, C. J.; Grancea, A.; Keenan, S. T.; Lam, S. K. H.; Foley, C. P.

    2016-06-01

    Superconducting quantum interference filters (SQIFs) have been created using two dimensional arrays of YBCO step-edge Josephson junctions connected together in series and parallel configurations via superconducting loops with a range of loop areas and loop inductances. A SQIF response, as evidenced by a single large anti-peak at zero applied flux, is reported at 77 K for step-edge junction arrays with the junction number N = 1 000 up to 20 000. The SQIF sensitivity (slope of peak) increased linearly with N up to a maximum of 1530 V T-1. Array parameters related to geometry and average junction characteristics are investigated in order to understand and improve the SQIF performance in high temperature superconducting arrays. Initial investigations also focus on the effect of the SQUID inductance factor on the SQIF sensitivity by varying both the mean critical current and the mean inductance of the loops in the array. The RF response to a 30 MHz signal is demonstrated.

  19. Experimental and numerical study of a YBCO pancake coil with a magnetic substrate

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Kvitkovic, J.; Pamidi, S. V.; Coombs, T. A.

    2012-12-01

    A finite element model for a YBCO pancake coil with a magnetic substrate is developed in this paper. An axial symmetrical H formulation and the E-J power law are used to construct the model, with the magnetic substrate considered by introducing an extra time-dependent term in the formula. A pancake coil is made and tested. The measurement of critical current and transport loss is compared to the model result, showing good consistency. The influence of magnetic substrate in the condition of AC and DC current is studied. The AC loss decreases without a magnetic substrate. It is observed that when the applied DC current approaches the critical current the coil turn loss profile changes completely in the presence of magnetic substrate due to the change of magnetic field distribution.

  20. 2D SQIF arrays using 20 000 YBCO high R n Josephson junctions

    NASA Astrophysics Data System (ADS)

    Mitchell, E. E.; Hannam, K. E.; Lazar, J.; Leslie, K. E.; Lewis, C. J.; Grancea, A.; Keenan, S. T.; Lam, S. K. H.; Foley, C. P.

    2016-06-01

    Superconducting quantum interference filters (SQIFs) have been created using two dimensional arrays of YBCO step-edge Josephson junctions connected together in series and parallel configurations via superconducting loops with a range of loop areas and loop inductances. A SQIF response, as evidenced by a single large anti-peak at zero applied flux, is reported at 77 K for step-edge junction arrays with the junction number N = 1 000 up to 20 000. The SQIF sensitivity (slope of peak) increased linearly with N up to a maximum of 1530 V T‑1. Array parameters related to geometry and average junction characteristics are investigated in order to understand and improve the SQIF performance in high temperature superconducting arrays. Initial investigations also focus on the effect of the SQUID inductance factor on the SQIF sensitivity by varying both the mean critical current and the mean inductance of the loops in the array. The RF response to a 30 MHz signal is demonstrated.

  1. BIG films fabricated by PLD for magnetic flux visualisation of YBCO

    NASA Astrophysics Data System (ADS)

    Kawano, K.; Chakalov, R. A.; Kong, G.; Abell, J. S.; Kahl, S.; Grishin, A. M.

    2002-08-01

    Bi 3Fe 5O 12 (BIG) magneto-optic (MO) films have been grown onto (1 1 1) and (1 0 0) gadolinium gallium garnet substrates by pulsed laser deposition (PLD). X-ray and transmission electron microscopy measurements have confirmed the epitaxial growth of the BIG films on both substrate orientations. Faraday rotation angles of both films showed linear field dependence from -1600 to +1600 G and the saturated Faraday rotation angle values were ∼5 deg/μm and ∼7.8 deg/μm for the (1 1 1) and (1 0 0) oriented films, respectively. A change in the MO contrast of both films in applied magnetic field has been observed and magnetic flux distributions have been visualised in YBa 2Cu 3O 7- x (YBCO) bulk superconductor using the (0 0 1) oriented BIG film.

  2. Radiation induced modifications on microstructure and related properties of high temperature superconductor YBCO

    NASA Astrophysics Data System (ADS)

    Marhas, Manmeet Kaur; Balakrishnan, K.; Saravanan, P.; Ganesan, V.; Srinivasan, R.; Kanjilal, D.; Mehta, G. K.; Vedwyas, M.; Ogale, S. B.; Pai, S. P.; Ramachandra Rao, M. S.; Pinto, R.; Mohan Rao, G.; Senthilnathan, S.; Mohan, S.

    Role of swift heavy ion irradiation on the modification of transport and structural properties of high temperature superconductors is studied. Good quality YBCO thin films prepared by high pressure oxygen sputtering and laser ablation were used in this investigation. Resistivity and atomic force microscopy (AFM) were mainly used to probe superconducting and microstructural modifications resulted from the irradiation of high energy and heavy ions like 100 MeV oxygen and 200 MeV silver. Radiation induced sputtering or erosion is likely to be a major disastrous component of such high energy irradiation that could be powerful in masking phase coherence effects, atleast in grain boundaries. The extent of damage/nature of defects other than columnar defects produced by swift heavy ions is discussed in the light of AFM measurements. The effect of high energy oxygen ion irradiation is anomalous. A clear annealing effect at higher doses is seen.

  3. Investigation of the bulk pinning force in YBCO superconducting films with nano-engineered pinning centres

    NASA Astrophysics Data System (ADS)

    Crisan, A.; Dang, V. S.; Yearwood, G.; Mikheenko, P.; Huhtinen, H.; Paturi, P.

    2014-08-01

    For practical applications of superconducting materials in applied magnetic fields, artificial pinning centres in addition to natural ones are required to oppose the Lorentz force. These pinning centres are actually various types of defects in the superconductor matrix. The pinning centres can be categorised on their dimension (volume, surface, or point) and on their character (normal cores or Δκ cores). We have used the Dew Hughes approach to determine the types of pinning centres present in various samples, with various thicknesses, temperatures and nanostructured additions to the superconducting matrix. Results show that normal surface pinning centres are present throughout almost all the samples, as dominant pinning mechanism. Such 2D extended pinning centres are mainly due to dislocations, grain boundaries, nanorods. Strong normal point pinning centres were found to be common in BZO doped YBCO samples. Other types of pinning centres, in various (minor) concentrations were also found in some of the samples.

  4. Magnetic levitation and its application for education devices based on YBCO bulk superconductors

    NASA Astrophysics Data System (ADS)

    Yang, W. M.; Chao, X. X.; Guo, F. X.; Li, J. W.; Chen, S. L.

    2013-10-01

    A small superconducting maglev propeller system, a small spacecraft model suspending and moving around a terrestrial globe, several small maglev vehicle models and a magnetic circuit converter have been designed and constructed. The track was paved by NdFeB magnets, the arrangement of the magnets made us easy to get a uniform distribution of magnetic field along the length direction of the track and a high magnetic field gradient in the lateral direction. When the YBCO bulks mounted inside the vehicle models or spacecraft model was field cooled to LN2 temperature at a certain distance away from the track, they could be automatically floating over and moving along the track without any obvious friction. The models can be used as experimental or demonstration devices for the magnetic levitation applications.

  5. (abstract) All Epitaxial Edge-geometry SNS Devices with Doped PBCO and YBCO Normal Layers

    NASA Technical Reports Server (NTRS)

    Barner, J. B.; Hunt, B. D.; Foote, M. C.

    1995-01-01

    We will present our results on tapered-edge-geometry SNS weak link fabricated from c-axis oriented base-, counterelectrode and normal layers using a variety of processing conditions. To date, we have employed a variety of different normal materials (Co-doped YBCO, Y-doped PBCO, Ca-doped PBCO). We have been examining the junction fabrication process in detail and we will present our methods. In particular, we have been examining both epitaxial and non-epitaxial milling mask overlayers and we will present a comparison of both methods. These devices behave similar to the expectations of the resisively shunted junction model and conventional SNS proximity effect models but with some differences which will be discussed. We will present the detailed systematics of our junctions including device parameters versus temperature, rf and dc magnetic response for the various processing conditions.

  6. Magnetization losses in superconducting YBCO conductor-on-round-core (CORC) cables

    NASA Astrophysics Data System (ADS)

    Majoros, M.; Sumption, M. D.; Collings, E. W.; van der Laan, D. C.

    2014-12-01

    Described are the results of magnetization loss measurements made at 77 K on several YBCO conductor-on-round-core (CORC) cables in ac magnetic fields of up to 80 mT in amplitude and frequencies of 50 to 200 Hz, applied perpendicular to the cable axis. The cables contained up to 40 tapes that were wound in as many as 13 layers. Measurements on the cables with different configurations were made as functions of applied ac field amplitude and frequency to determine the effects of their layout on ac loss. In large scale devices such as e.g. Superconducting Magnetic Energy Storage (SMES) magnets, the observed ac losses represent less than 0.1% of their stored energy.

  7. Numerical simulation and analysis of single grain YBCO processed from graded precursor powders

    NASA Astrophysics Data System (ADS)

    Zou, J.; Ainslie, M. D.; Hu, D.; Zhai, W.; Devendra Kumar, N.; Durrell, J. H.; Shi, Y.-H.; Cardwell, D. A.

    2015-03-01

    Large single-grain bulk high-temperature superconducting materials can trap high magnetic fields in comparison with conventional permanent magnets, making them ideal candidates to develop more compact and efficient devices, such as actuators, magnetic levitation systems, flywheel energy storage systems and electric machines. However, macro-segregation of Y-211 inclusions in melt processed Y-Ba-Cu-O (YBCO) limits the macroscopic critical current density Jc of such bulk superconductors, and hence, the potential trapped field. Recently, a new fabrication technique with graded precursor powders has been developed, which results in a more uniform distribution of Y-211 particles, in order to further improve the superconducting properties of such materials. In order to develop this graded fabrication technique further, a 3D finite-element numerical simulation based on the H-formulation is performed in this paper. The trapped field characteristics of a graded YBCO sample magnetized by the field cooling method are simulated to validate the model, and the simulation results are consistent with the experimental measurements. In addition, the influence of the graded technique and various graded Jc distributions for pulsed field magnetization, recognized widely as a practical route for magnetizing samples in bulk superconductor applications, is also investigated, with respect to the trapped field and temperature profiles of graded samples. This modelling framework provides a new technique for assessing the performance of various sizes and geometries of graded bulk superconductors, and by adjusting the Y-211, and hence Jc, distribution, samples can be fabricated based on this concept to provide application-specific trapped field profiles, such as the generation of either a high magnetic field gradient or a high level of uniformity for the traditionally conical, trapped field profile.

  8. Planar tunneling into Zn and Ni-doped YBCO thin films

    NASA Astrophysics Data System (ADS)

    Badica, E.; Greene, L. H.

    2001-03-01

    Superconducting thin films of Y_1Ba_2Cu_3-xM_xO_7-delta (M = Zn, Ni; x = 0, 0.01, 0.02, 0.08, and 0, 0.01, 0.02, 0.24 respectively) are grown in different crystallographic orientations, classified into c-axis and ab-oriented. The critical temperatures of the films are 90, 84, 81, 60K, and 90, 81 77K, for Zn and Ni doping, respectively. Planar tunneling spectroscopy into the ab-planes, using Pb and Bi counter-electrodes, shows that the gap-like feature scales with the critical temperature, and the magnitude of the surface-induced Andreev bound states (ABS) seen at zero bias decreases with increasing doping concentration. In the case of Zn-doping, the surface-induced ABS are quenched for the highest doping concentration used, consistent with previous measurements on ion-irradiated (1) and Pr-doped (2) YBCO thin films. A detailed comparison (3) of the influence of doping and disorder on the low-energy density of states of YBCO, as a function of temperature and externally applied magnetic field, will be presented. We acknowledge support from NSF (DMR 94-21957) and NSF (DMR 99-72087). 1. M. Aprili, M. Covington, E. Paraoanu, B. Niedermeier, and L. H. Greene, Phys. Rev. B 57, R8139 (1998); 2. M. Covington, and L. H. Greene, Phys. Rev. B 62, 12 440 (2000); 3. E. Badica, M. Aprili, M. Covington, and L. H. Greene, Proceedings for the SPIE 2000 Aerosense Symposium, 'Oxide Superconductors: Physics and Nano-engineering IV', April 24-28, 2000, Orlando, Florida.

  9. Magnetic moment of single vortices in YBCO nano-superconducting particle: Eilenberger approach

    NASA Astrophysics Data System (ADS)

    Zakharchuk, I.; Sharafeev, A.; Belova, P.; Safonchik, M.; Traito, K. B.; Lähderanta, E.

    2013-12-01

    Temperature dependence of single vortex magnetic moment in nanosize superconducting particles is investigated in the framework of quasiclassical Eilenberger approach. Such nanoparticles can be used for preparation of high-quality superconducting thin films with high critical current density. In contrast to bulk materials where the vortex magnetic moment is totally determined by flux quantum, in nano-sized specimens (with characteristic size, D, much less than effective penetration depth, λeff) the quantization rule is violated and magnetic moment is proportional to D2/λ2eff(T). Due to strong repulsion between vortices in nanoparticles only a single vortex can be trapped in them. Because of small size of particles the screening current of the vortex is located near the vortex core where the current is quite high and comparable to depairing currents. Therefore, the superconducting electron density, ns, depends on the current value and the distance from the vortex core. This effect is especially important for superconductors having gap nodes, such as YBCO. The current dependence of ns in nanoparticles is analogous to the Volovik effect in flux-line lattice in bulk samples. The magnitude of the effect can be obtained by comparing the temperature dependence of magnetic moment in the vortex and in the Meissner states. In the last case the value of screening current is small and superconducting response to the external field is determined by London penetration depth. Because of importance of nonlinear and nonlocal effects, the quantum mechanical Eilenberger approach is applied for description of the vortex in nanoparticles. The flattening of 1/λ2eff(T) dependence has been found. A comparison of the theoretical results with experimental magnetization data in Meissner and mixed states of YBCO nanopowders has been done. The presence of nonlinear and nonlocal effects in vortex current distribution is clearly visible. The obtained results are important for the description

  10. Size effects of nano-scale pinning centers on the superconducting properties of YBCO single grains

    NASA Astrophysics Data System (ADS)

    Moutalbi, Nahed; Noudem, Jacques G.; M'chirgui, Ali

    2014-08-01

    High pinning superconductors are the most promising materials for power engineering. Their superconducting properties are governed by the microstructure quality and the vortex pinning behavior. We report on a study of the vortex pinning in YBa2Cu3O7-x (YBCO) single grain with defects induced through the addition of insulating nano-particles. In order to improve the critical current density, YBCO textured bulk superconductors were elaborated using the Top Seeded Melt Texture and Growth process with different addition amounts of Al2O3 nano-particles. Serving as strong pinning centers, 0.05% excess of Al2O3 causes a significant enhancement of the critical current density Jc under self field and in magnetic fields at 77 K. The enhanced flux pinning achieved with the low level of alumina nano-particles endorses the effectiveness of insulating nano-inclusions to induce effectives pinning sites within the superconducting matrix. On the other side, we focused on the effect of the size of pinning centers on the critical current density. This work was carried out using two batches of alumina nano-particles characterized by two different particle size distributions with mean diameters PSD1 = 20 nm and PSD2 = 2.27 μm. The matching effects of the observed pinning force density have been compared. The obtained results have shown that the flux pinning is closely dependent on the size of the artificial pinning centers. Our results suggest that the optimization of the size of the artificial pinning centers is crucial to a much better understanding of the pinning mechanisms and therefore to insure high superconducting performance for the practical application of superconducting materials.

  11. Loss of PLA2G6 leads to elevated mitochondrial lipid peroxidation and mitochondrial dysfunction

    PubMed Central

    Castillo-Quan, Jorge Iván; Bartolome, Fernando; Angelova, Plamena R.; Li, Li; Pope, Simon; Cochemé, Helena M.; Khan, Shabana; Asghari, Shabnam; Bhatia, Kailash P.; Hardy, John; Abramov, Andrey Y.; Partridge, Linda

    2015-01-01

    The PLA2G6 gene encodes a group VIA calcium-independent phospholipase A2 beta enzyme that selectively hydrolyses glycerophospholipids to release free fatty acids. Mutations in PLA2G6 have been associated with disorders such as infantile neuroaxonal dystrophy, neurodegeneration with brain iron accumulation type II and Karak syndrome. More recently, PLA2G6 was identified as the causative gene in a subgroup of patients with autosomal recessive early-onset dystonia-parkinsonism. Neuropathological examination revealed widespread Lewy body pathology and the accumulation of hyperphosphorylated tau, supporting a link between PLA2G6 mutations and parkinsonian disorders. Here we show that knockout of the Drosophila homologue of the PLA2G6 gene, iPLA2-VIA, results in reduced survival, locomotor deficits and organismal hypersensitivity to oxidative stress. Furthermore, we demonstrate that loss of iPLA2-VIA function leads to a number of mitochondrial abnormalities, including mitochondrial respiratory chain dysfunction, reduced ATP synthesis and abnormal mitochondrial morphology. Moreover, we show that loss of iPLA2-VIA is strongly associated with increased lipid peroxidation levels. We confirmed our findings using cultured fibroblasts taken from two patients with mutations in the PLA2G6 gene. Similar abnormalities were seen including elevated mitochondrial lipid peroxidation and mitochondrial membrane defects, as well as raised levels of cytoplasmic and mitochondrial reactive oxygen species. Finally, we demonstrated that deuterated polyunsaturated fatty acids, which inhibit lipid peroxidation, were able to partially rescue the locomotor abnormalities seen in aged flies lacking iPLA2-VIA gene function, and restore mitochondrial membrane potential in fibroblasts from patients with PLA2G6 mutations. Taken together, our findings demonstrate that loss of normal PLA2G6 gene activity leads to lipid peroxidation, mitochondrial dysfunction and subsequent mitochondrial membrane

  12. Identification of Aquifex aeolicus tRNA (m2(2G26) methyltransferase gene.

    PubMed

    Takeda, Hiroshi; Hori, Hiroyuki; Endo, Yaeta

    2002-01-01

    The modifications of N2,N2-dimethylguanine (m2(2)G) are found in tRNAs and rRNAs from eukarya and archaea. In tRNAs, modification at position G26 is generated by tRNA (m2(2)G26) methyltransferase, which is encoded by the corresponding gene, trm1. This enzyme catalyzes the methyl-transfer from S-adenosyl-L-methionine to the semi-conserved residue, G26, via the intermediate modified base, m2G26. Recent genome sequencing project has been reported that the putative trm1 is encoded in the genome of Aquifex aeolicus, a hyper-thermophilic eubacterium as only one exception among eubacteria. In order to confirm whether this bacterial trm1 gene product is a real tRNA (m2(2)G26) methyltransferase or not, we expressed this protein by wheat germ in vitro cell-free translation system. Our biochemical analysis clearly showed that this gene product possessed tRNA (m2(2)G26) methyltransferase activity.

  13. Magnetic and magnetotransport characterization of La0.7Sr0.3MnO3/YBCO/La0.7Sr0.3MnO3/YBCO spin valve

    NASA Astrophysics Data System (ADS)

    Dybko, K.; Aleshkevych, P.; Sawicki, M.; Przyslupski, P.

    2015-01-01

    We present magnetoresistance measurements on La0.7Sr0.3MnO3/YBCO/La0.7Sr0.3MnO3/YBCO (L1/Y1/L2/Y) heterostructure. The Ll/Y1/L2/Y spin valve shows large magnetoresistance peaks in coercive field at temperatures below the onset of the superconducting transition. The rotation in parallel magnetic field demonstrates a change of magnetoresistance; simultaneously the transition temperature to superconducting state Tc0(H=450 Oe, β) exhibits nonmonotonic dependence due to change of noncolinearity of magnetic moments of LSMO layers. Nonmonotonic change of the transition temperature as a function of angle is interpreted as a signature of generation of the triplet component superconducting phase in the Ll/Y1/L2/Y heterostructure.

  14. THE VITAMIN B(1) AND B(2) G CONTENT OF LIVER EXTRACT AND BREWERS' YEAST CONCENTRATE.

    PubMed

    Miller, D K; Rhoads, C P

    1934-02-28

    1. Liver extract powder, No. 343 Lilly, and the same material prepared for parenteral use, when administered daily by mouth in amounts derived from 2.5 gm. of fresh whole liver, to rats weighing from 40 to 50 gm., contain sufficient vitamin B(1) to support normal growth, provided the animals receive in addition an adequate amount of vitamin B(2) G. Moreover, liver extract in the forms mentioned, administered in the same amounts, does not contain sufficient vitamin B(2) G to maintain normal growth of similar rate when all other necessary constituents of the diet are provided. 2. Liver extract (Lilly) in the form prepared for parenteral use, when administered daily by intraperitoneal injections, in amounts derived from 2.5 gm. of fresh whole liver, to rats under standard experimental conditions, does not contain sufficient vitamin B(2) G to maintain normal growth. Furthermore, the amount of vitamin B(1) present in liver extract in this form is not as effective in supporting normal growth when given by intraperitoneal injection as it is when given by mouth. 3. Vegex, when administered daily in amounts of 50, 150, and 250 mg. to rats of 40 to 50 gm. in weight contains sufficient vitamin B(1) to maintain normal growth of the rats, provided the animals receive in addition an adequate amount of vitamin B(2) G. However, vegex in the same amounts does not contain sufficient vitamin B(2) G to support normal growth of similar rats when all other necessary constituents of the diet are provided. 4. These experiments indicate that the extrinsic, anti-anemic factor of Castle and the thermostable growth-promoting food constituent, commonly known as vitamin B(2) G, are not identical.

  15. Metal Coatings

    NASA Technical Reports Server (NTRS)

    1994-01-01

    During the Apollo Program, General Magnaplate Corporation developed process techniques for bonding dry lubricant coatings to space metals. The coatings were not susceptible to outgassing and offered enhanced surface hardness and superior resistance to corrosion and wear. This development was necessary because conventional lubrication processes were inadequate for lightweight materials used in Apollo components. General Magnaplate built on the original technology and became a leader in development of high performance metallurgical surface enhancement coatings - "synergistic" coatings, - which are used in applications from pizza making to laser manufacture. Each of the coatings is designed to protect a specific metal or group of metals to solve problems encountered under operating conditions.

  16. Crystalline phase transition information induced by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ

    NASA Astrophysics Data System (ADS)

    Zhang, C. P.; Chaud, X.; Beaugnon, E.; Zhou, L.

    2015-01-01

    The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the crystalline phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu2O reciprocally as well as the copper ion valence changed between divalent Cu2+ and trivalent Cu1+ each other. It was essential to keep quantities of CuO phase instead of the Cu2O for Y123 crystal solidification.

  17. Strong vortex matching effects in YBCO films with periodic modulations of the superconducting order parameter fabricated by masked ion irradiation

    NASA Astrophysics Data System (ADS)

    Haag, L. T.; Zechner, G.; Lang, W.; Dosmailov, M.; Bodea, M. A.; Pedarnig, J. D.

    2014-08-01

    We report on measurements of the magnetoresistance and of the critical current in thin films of the high-temperature superconductor YBa2Cu3O7-δ (YBCO). A square array of regions with suppressed superconducting order parameter has been created in these films by introducing point defects via irradiation with He+ ions through a silicon stencil mask. In such a structure distinct peaks of the critical current can be observed at commensurate arrangements of magnetic flux quanta with the artificial defect lattice. Concurrently, the magnetoresistance shows pronounced minima. Both observations demonstrate that the strong intrinsic pinning in YBCO can be overcome by a periodic array of ion-damage columns with 300 nm spacing.

  18. EBSD characterisation of Y2Ba4CuUOx phase in melttextured YBCO with addition of depleted uranium oxide

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Mücklich, F.; Koblischka, M. R.; Babu, N. Hari; Cardwell, D. A.

    2006-06-01

    Melt-textured YBCO samples processed with added Y2O3 and depleted uranium oxide (DU) contain nano-particles, which have been identified previously as Y2Ba4CuUOx (U-411). This phase has a cubic unit cell, which is clearly distinct from the orthorhombic Y-123 and Y-211 phases within the YBCO system. In samples with a high amount of DU addition (0.8 wt-% DU), U-2411 particles have sizes between 200 nm and several µm, so identification of the Kikuchi patterns of this phase becomes possible. Together with a parallel EDX analysis, the particles embedded in the Y-123 matrix can be identified unambiguously. In this way, a three-phase EBSD scan becomes possible, allowing also the identification of nanometre-sized particles in the sample microstructure.

  19. A simple multi-seeding approach to growth of large YBCO bulk with a diameter above 53 mm

    NASA Astrophysics Data System (ADS)

    Tang, Tian-wei; Wu, Dong-jie; Wu, Xing-da; Xu, Ke-Xi

    2015-12-01

    A successful simple multi-seeding approach to growing large size Y-Ba-C-O (YBCO) bulks is reported. Compared with the common single seeding method, our multi-seeding method is more efficient. By using four SmBa2Cu3O7-δ (Sm-123) seeds cut from a large size Sm-Ba-C-O (SmBCO) single domain, large YBCO samples up to 53 mm in diameter could be produced successfully and 100 mm diameter samples can also be grown. Experimental results show that the processing time can be shortened greatly by using this new approach, and the superconducting properties can also be improved. The Hall probe mapping shows that the trapped field distribution of 53 mm diameter multi-seeded sample is homogeneous and the peak value is up to 0.53 T. The magnetic levitation force density reaches to 14.7 N/cm2 (77 K, 0.5 T).

  20. Development of a 20 GHz scanned beam microstrip antenna array with a proximity coupled YBCO feed network

    SciTech Connect

    Mittleman, S.D.; Herd, J.S.; Kenny, J.P.; Poles, L.D.; Champion, M.H.; Rainville, P.J.; Silva, J.H.

    1994-12-31

    A superconducting antenna array with a proximity coupled feed network operating at 20 GHz has been developed. The antenna is a 4x4 array and its performance was measured from 18 GHz to 22 GHz. At temperatures below 80 K, there was a 15 dBi gain measured at several frequencies in this range. The design of a low loss superconducting phase shifter monolithically incorporated into the YBCO feed network is indicated.

  1. Anisotropy of 2G HTS racetrack coils in external magnetic fields

    NASA Astrophysics Data System (ADS)

    Chudy, Michal; Chen, Yiran; Zhang, Min; Coombs, T. A.

    2013-07-01

    Pancake or racetrack coils wound with second generation high-temperature superconductors (2G HTSs) are important elements for numerous applications of HTS. The applications of these coils are primarily in rotating machines such as motors and generators where they must withstand external magnetic fields from various orientations. The characterization of 2G HTS coils is mostly focused on AC loss assessment, critical current and maximum magnetic field evaluation. In this study, racetrack coils will be placed in different orientations of external magnetic fields—Jc (Ic) versus angle measurements will be performed and interpreted. Full attention is paid to studies of anisotropy Jc versus angle curves for short samples of 2G HTS tapes. As will be shown, the shape of the Jc versus angle curves for tapes has a strong influence on the Jc (Ic) versus angle curves for coils. In this work, a unique and unpredicted behavior of the Jc versus angle curves for the 2G HTS racetrack coils was found. This will be analyzed and fully explained.

  2. Effects of 2 G hypergravity exposure on Bobwhite (Colinus virginianus) and Japanese quail (Coturnix coturnix japonica)

    NASA Technical Reports Server (NTRS)

    Ronca, April E.; Baer, Lisa A.; Everett, Erin M.; Shaughnessey, Rebecca; Foushee, Rebecca E.

    2004-01-01

    We compared reproductive fitness and early postnatal growth of Bobwhite (Colinus virginianus) and Japanese (Coturnix coturnix japonica) quail incubated and hatched during 2 G centrifugation. Fertilized Bobwhite and Japanese quail eggs were placed in portable incubators on the 8-ft International Space Station Test Bed (ISSTB) Centrifuge at NASA Ames Research Center. The quail eggs were incubated throughout hatching and reared until Postnatal day (P)4 at either 1.0, 1.2 or 2.0 G. Two days before hatching, candling revealed significantly greater numbers of viable Bobwhite than Japanese quail eggs at all g-loads. Bobwhite quail exhibited significantly better hatching success at all g-loads than did Japanese quail. Bobwhite hatchlings were sensitive to gravitational loading as evidenced by reduced postnatal body mass and length of 2 G hatchlings relative to 1 G control hatchlings. In contrast, mass and length of Japanese quail hatchlings were unaffected by 1.2 or 2 G exposure. Together, our findings provide evidence for superior viability and hatching success in Bobwhite quail relative to Japanese quail, coupled with greater sensitivity of postnatal body growth and development to 2 G loading. Bobwhite quail may be better suited than Japanese quail for scientific studies on space biology platforms.

  3. The effect of a BRN 3.1 deletion on the temperature response to 2G

    NASA Technical Reports Server (NTRS)

    Murakami, D. M.; Erkman, L.; Rosenfeld, M. G.; Fuller, C. A.

    1998-01-01

    Researchers studied the effect of 2G exposure on body temperature in Wild type and BRN 3.1 Knockout mice to determine the feasibility to using BRN 3.1 Knockout mice as an animal model of the effects of altered gravitational fields on vestibular system physiology.

  4. 76 FR 36618 - Proposed Collection; Comment Request for Form W-2G

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form W-2G, Certain Gambling Winnings... through the Internet, at Allan.M.Hopkins@irs.gov . SUPPLEMENTARY INFORMATION: Title: Certain Gambling..., 3402(q), and 3406 require payers of certain gambling winnings to withhold tax and to report...

  5. 78 FR 57219 - Proposed Collection; Comment Request for Form W-2G

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form W-2G, Certain Gambling Winnings...@irs.gov . SUPPLEMENTARY INFORMATION: Title: Certain Gambling Winnings. OMB Number: 1545-0238. Form... certain gambling winnings to withhold tax and to report the winnings to the IRS. IRS uses the...

  6. Solution structure and dynamics of human ubiquitin conjugating enzyme Ube2g2

    PubMed Central

    Ju, Tingting; Bocik, William; Majumdar, Ananya; Tolman, Joel R.

    2009-01-01

    Ube2g2 is an E2 enzyme which functions as part of the endoplasmic reticulum-associated degradation (ERAD) pathway responsible for identification and degradation of misfolded proteins in the endoplasmic reticulum. In tandem with a cognate E3 ligase, Ube2g2 assembles K48-linked polyubiquitin chains and then transfers them to substrate, leading ultimately to proteasomal degradation of the polyubiquitin-tagged substrate. We report here the solution structure and backbone dynamics of Ube2g2 solved by nuclear magnetic resonance spectroscopy. Although the solution structure agrees well with crystallographic structures for the E2 core, catalytically important loops (encompassing residues 95-107 and 130-135) flanking the active site cysteine are poorly defined. 15N spin relaxation and residual dipolar coupling analysis directly demonstrates that these two loops are highly dynamic in solution. These results suggest that Ube2g2 requires one or more of its protein partners, such as cognate E3, acceptor ubiquitin substrate or thiolester-linked donor ubiquitin, in order to assume its catalytically relevant conformation. Within the NMR structural ensemble, interactions were observed between His94 and the highly mobile loop residues Asp98 and Asp99, supporting a possible role for His94 as a general base activated by the carboxylate side-chains of Asp98 or Asp99. PMID:20014027

  7. Overview of Shipyard coast line with Piers G1, G2, G3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview of Shipyard coast line with Piers G-1, G-2, G-3, G-4, and G-5 in view, view facing east-southeast - U.S. Naval Base, Pearl Harbor, Pier & Quay Walls, Entrance to Dry Dock No. 2 & Repair Wharfs, east & west sides of Dry Dock No. 2 & west side of Dry Dock No. 3, Pearl City, Honolulu County, HI

  8. Security enhancement mechanism based on contextual authentication and role analysis for 2G-RFID systems.

    PubMed

    Tang, Wan; Chen, Min; Ni, Jin; Yang, Ximin

    2011-01-01

    The traditional Radio Frequency Identification (RFID) system, in which the information maintained in tags is passive and static, has no intelligent decision-making ability to suit application and environment dynamics. The Second-Generation RFID (2G-RFID) system, referred as 2G-RFID-sys, is an evolution of the traditional RFID system to ensure better quality of service in future networks. Due to the openness of the active mobile codes in the 2G-RFID system, the realization of conveying intelligence brings a critical issue: how can we make sure the backend system will interpret and execute mobile codes in the right way without misuse so as to avoid malicious attacks? To address this issue, this paper expands the concept of Role-Based Access Control (RBAC) by introducing context-aware computing, and then designs a secure middleware for backend systems, named Two-Level Security Enhancement Mechanism or 2L-SEM, in order to ensure the usability and validity of the mobile code through contextual authentication and role analysis. According to the given contextual restrictions, 2L-SEM can filtrate the illegal and invalid mobile codes contained in tags. Finally, a reference architecture and its typical application are given to illustrate the implementation of 2L-SEM in a 2G-RFID system, along with the simulation results to evaluate how the proposed mechanism can guarantee secure execution of mobile codes for the system.

  9. Alterations of Body Mass Gain of Neonates (P7&P14) During Certrifugation AT 2G

    NASA Technical Reports Server (NTRS)

    Baer, L. A.; Corbin, B. J.; Wade, C. E.; Hargens, Alan R. (Technical Monitor)

    1996-01-01

    Previous research has shown animal body mass to be significantly affected by centrifugation. At the onset of centrifugation, animals have a selective loss of fat, causing an initial body mass loss. Body mass gain will resume at the same rate as uncentrifuged animals, but this subsequent gain will be lower. For this study, two different ages of Sprague Hawley neonate families were observed during centrifugation. Eight litters (dam with eight neonates) of postnatal day (PN) seven and four litters (dam with ten neonates) of PN 14 were separated into two separate groups each, centrifuge (+2G(sub z)) and environmental controls (EC) and placed into either the centrifuge or an animal holding unit in the centrifuge rotunda for a total of 16 days. P7: Total litter start mass of +2G(sub z) litter = 138.90 g/end = 311.0 g EC litter = 150.85 g/end = 516.9 g. P14: Total litter start mass of +2G(sub z) litter = 287.70 g/end = 762.5g; EC litter = 245 g/end = 942.9 g. An initial body mass loss was observed in both groups of +2G(sub z) animals for two days after the onset of centrifugation, but then an increase began to occur. Literature suggests adult animals at +2G(sub z), will have an initial loss, but will resume similar growth rates over time as compared to control animals. The P7 +2G(sub z) animals began to gain body mass, but showed a significantly slower growth rate than their EC animals for the duration of the test (pace). The P14 +2G(sub z) animals began to show similar growth rates to their EC after day nine. At day 16, both groups of +2Gz animals were significantly smaller than the EC animals (pace). At +2Gz, animals experience an initial body mass loss. Older animals are able to resume similar growth rates as their controls, but younger animals showed growth rates to be significantly reduced.

  10. Improvements in Crystal Structure of Two Inch Double-Sided YBCO Thin Films by Preseeded Self-Template Layer

    NASA Astrophysics Data System (ADS)

    Li, Yanrong; Liu, Xingzhao; Tao, Bowan; Zhang, Ying; Deng, Xinwu

    2003-03-01

    A self-template layer was employed to improve the crystal structure and microwave properties of large-area double-sided YBCO thin films. Two-inch double-sided YBCO thin films with excellent out-of-plane orientation and lateral homogeneity of microwave surface resistance were prepared by using a preseeded self-template layer. The full width at half maximum (FWHM) value of the rocking curve as low as 0.15° was achieved. The electronic channeling pattern was very sharp, clear and symmetric. The values of microwave surface resistance Rs (75 K, 145 GHz, 0 T) below 55 mΩ were obtained over the entire YBCO thin films on 2-inch LaAlO3 wafers. The majority of the wafer area given in percent has Rs (75 K, 145 GHz, 0 T) values in the range from 15 mΩ to 40 mΩ. The high frequency (HF) power handling capability was demonstrated by a breakdown field higher than 6 mT at 8.5 GHz and 77 K.

  11. Peculiarities of the current-voltage characteristics of a Josephson medium in a YBCO high-temperature superconductor

    NASA Astrophysics Data System (ADS)

    Vasyutin, M. A.

    2013-12-01

    The influence of a weak magnetic field ( H < 150 Oe) on the current-voltage ( I- U) characteristic of a YBa2Cu3O7 - x (YBCO) high-temperature superconductor (HTSC) near the superconducting transition temperature has been studied. It is established that there exist narrow (<0.2 K) temperature regions where the I- U curve exhibits sharp bending for H < 30 Oe and the ohmic behavior changes to a quadratic dependence of the voltage on current in a region of several milliamperes. At higher temperatures, the I- U curve bending exhibits smearing. This behavior is observed at a temperature below that corresponding to a zero critical current. Above a certain current, the temperature and magnetic field exhibit equivalent effects on the I- U curve of YBCO. Experimental results are explained by a sharp decrease in the critical currents of intergranular Josephson junctions under the action of magnetic field and by the current-induced formation of uncoupled (with respect to the order parameter) superconducting grains. Characteristic currents for the transition of the intergranular Josephson medium into an incoherent state are determined and the first critical fields in YBCO are evaluated.

  12. An electron backscatter diffraction investigation of crystallographic orientations of embedded nanoparticles within melt-textured YBCO high temperature superconductors

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Babu, N. Hari; Cardwell, D. A.; Shlyk, L.; Krabbes, G.

    2006-07-01

    Microstructures of melt-textured YBCO samples with embedded nanosized particles of Y2BaCuO5 (Y-211) and Y2Ba4CuMOx (M-2411 with M = U,Zr) are analysed by means of electron backscatter diffraction (EBSD). With the recent developments of the EBSD technique, we can directly measure the crystallographic orientation of the embedded nanoparticles, employing a spatial resolution of about 40 nm. The high image quality of the Kikuchi patterns allows true three-phase (YBCO, Y-211 and M-2411) scans to be performed. The Y-211 particles do not exhibit any preferred orientation, even if their size is considerably reduced, to the 100 nm range. The size reduction reduces the negative influence of the Y-211 particles on the YBCO matrix, however. U-2411 particles, which are formed during the processing stage, do not show any orientation, and with increasing concentration, some texture develops. In contrast to this, embedded Zr-2411 particles are fully oriented in the (001) orientation according to the surrounding superconducting matrix.

  13. Field Performance of an Optimized Stack of YBCO Square “Annuli” for a Compact NMR Magnet

    PubMed Central

    Hahn, Seungyong; Voccio, John; Bermond, Stéphane; Park, Dong-Keun; Bascuñán, Juan; Kim, Seok-Beom; Masaru, Tomita; Iwasa, Yukikazu

    2011-01-01

    The spatial field homogeneity and time stability of a trapped field generated by a stack of YBCO square plates with a center hole (square “annuli”) was investigated. By optimizing stacking of magnetized square annuli, we aim to construct a compact NMR magnet. The stacked magnet consists of 750 thin YBCO plates, each 40-mm square and 80- μm thick with a 25-mm bore, and has a Ø10 mm room-temperature access for NMR measurement. To improve spatial field homogeneity of the 750-plate stack (YP750) a three-step optimization was performed: 1) statistical selection of best plates from supply plates; 2) field homogeneity measurement of multi-plate modules; and 3) optimal assembly of the modules to maximize field homogeneity. In this paper, we present analytical and experimental results of field homogeneity and temporal stability at 77 K, performed on YP750 and those of a hybrid stack, YPB750, in which two YBCO bulk annuli, each Ø46 mm and 16-mm thick with a 25-mm bore, are added to YP750, one at the top and the other at the bottom. PMID:22081753

  14. Effect of addition of BaTiO3 nano particles on the electrical transport properties of YBCO superconductor

    NASA Astrophysics Data System (ADS)

    Rejith, P. P.; Vidya, S.; Thomas, J. K.

    2015-02-01

    The flux pinning properties of YBCO bulk superconductors synthesized by conventional solid state route and are added with different weight% (x=0, 0.5, 1, 2, 3, 5) of nano BaTiO3 which are prepared by a modified combustion route are studied systematically. The phase analysis of the samples was done by using X-ray diffraction and scanning electron microscopy. Temperature-resistivity measurements, magnetic field dependence of critical current density (Jc-B Characteristics) and flux pinning force calculations were done at 77 K. From the SEM images the microstructure of the sample showed a relative uniform distribution of the nano-particles within the specimen. We found that, even though the transition temperature (Tc) does not change considerably with the BaTiO3 addition, both the critical current density (Jc) and flux pinning force (Fp) increased systematically up to 2 wt% BaTiO3 in the composite, in the presence of magnetic field ranging between 0 and 0.6 T. The Jc value in 2 wt% BaTiO3 added sample showed at least 250% larger than that of the pure YBCO. Also the flux pinning force calculated for the 2 wt% BaTiO3 added is found to be enhanced more than 9 times that of pure YBCO. These observations suggest that the BaTiO3 addition to the Y-123- compounds improve the electrical connection between superconducting grains to result in the increase in Jc.

  15. Persistent currents in a magnetic bearing with coated conductors

    NASA Astrophysics Data System (ADS)

    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.

  16. Pulsed laser deposition of c-axis untilted YBCO films on c-axis tilted ISD MgO-buffered metallic substrates

    NASA Astrophysics Data System (ADS)

    Li, M.; Ma, B.; Koritala, R. E.; Fisher, B. L.; Venkataraman, K.; Maroni, V. A.; Vlasko-Vlasov, V.; Berghuis, P.; Welp, U.; Gray, K. E.; Balachandran, U.

    2003-05-01

    Biaxially textured MgO template layer was deposited on nontextured metal substrates by inclined-substrate deposition (ISD) at a deposition rate of 24-600 nm/min. c-axis untilted YBa 2Cu 3O 7- x (YBCO) films were deposited on these MgO-buffered substrates by pulsed laser deposition. The crystalline structures of the YBCO films and MgO layers were examined by X-ray pole figure analysis, X-ray φ-scans, and χ-scans. A tilt angle of 33° of the MgO[0 0 1] with respect to the substrate normal and c-axis untilted YBCO films were observed, respectively. Good biaxial texture of these films with full-width-at-half-maximum values of 13.8° and 10.6° for the φ-scans of YBCO(1 0 3) and MgO(2 2 0), respectively, were obtained. Morphologies were examined by scanning electron microscopy, which revealed a unique roof-tile feature and columnar grain growth for the ISD MgO layer. Raman spectroscopy and magneto-optical image technique were also used to evaluate the quality of the YBCO film. An angular dependence of Jc on the direction of an applied magnetic field confirmed the c-axis untilted orientation of the YBCO films. Tc=90 K with sharp transition and Jc=3.0×10 5 A/cm 2 at 77 K in zero field were obtained on 0.4-μm-thick YBCO films.

  17. Modeling the Critical Current Decrease in Coated Conductors with Film Thickness

    SciTech Connect

    D. Agassi; D.K. Christen; S.J. Pennycook

    2007-01-01

    YBCO-based Coated Conductors (CC) are touted as the next generation of high current=carrying capacity High Temperature Superconductors (HTS) wires. If commercially viable, CC will signal a revolution in power trnasmission, with enormous economic consequences. It has been recently reported that the observed ciritical current in such CC is decreasing with the fil thickness d, roughly as d-1/2. The origin of this decrease is not understood. This work is aimed at developing a simple model to explain this feature.

  18. Influence of superconductor film composition on adhesion strength of coated conductors

    SciTech Connect

    Kesgin, Ibrahim; Khatri, Narayan; Liu, Yuhao; Delgado, Louis; Galstyan, Eduard; Selvamanickam, Venkat

    2015-11-20

    The effect of high temperature superconductor (HTS) film composition on the adhesion strength of rare- earth barium copper oxide coated conductors (CCs) has been studied. It has been found that the mechanical integrity of the superconductor layer is very susceptible to the defects especially those along the ab plane, probably due to the weak interfaces between the defects and the matrix. Gd and Y in the standard composition were substituted with Sm and the number of in-plane defects was drastically reduced. Consequently, a four-fold increase in adhesion or peeling strength in Sm-based CCs was achieved compared to the standard GdYBCO samples.

  19. Analysis of the hematopoietic tissue in Pleurodeles waltl newts exposed to 2 g hypergravity

    NASA Astrophysics Data System (ADS)

    Domaratskaya, Elena; Nikonova, Tatyana M.; Grigoryan, Eleonora N.; Dvorochkin, Natalya; Yousuf, Rukhsana; Almeida, Eduardo; Butorina, Nina N.

    2012-07-01

    Gravity is an important factor in creating biologically-relevant mechanical loads, and in spaceflight living organisms encounter both microgravity as well as hypergravity conditions. Here we studied the influence of hypergravity on the hematopoietic tissue of P. waltl newts in parallel with tissue regeneration experiments of the newt lens and tail. At day 9 post-surgery one group of newts was subjected to centrifugation at 2 g (2G, 12 days), while another was kept at 1 g. In addition, a basal control in wet mats, at 1g, (BC, 1G), and an aquarium control, neutrally buoyant, (AC, low G), were also performed. Differential blood counts and histological analysis of the spleen and liver were carried out in experimental and control groups of animals. At day 21 post-surgery in all groups (AC, 1G, and 2G), the number of neutrophils in the blood was significantly lower than in BC indicating a decrease in the inflammation induced by surgery. The 2G group however, showed numbers of neutrophils significantly higher than AC (neutrally buoyant) animals. This result suggests that post-operative inflammation can persist longer at 2 g that under unloaded aquarium conditions. In contrast we did not observe any significant differences in lymphocyte numbers between any experimental and control groups. Histological examination of the liver and spleen also did not show any significant morphological alterations due to hypergravity. These results indicate that 12 day exposure to hypergravity at 2 g, had only partial influence on newt hematopoiesis, possibly extending the duration of surgery-related inflammatory responses. Data obtained with newts in our previous experiments on Foton-M2 and Foton-M3 flights in microgravity also showed only slight effect on blood cells. Furthermore microgravity also did not cause any morphological changes in the hematopoietic and lymphoid tissues, and did not impair the proliferative capacity of newt hematopoietic cells. In sum these results indicate the

  20. Differences in Shiga toxin and phage production among stx2g-positive STEC strains

    PubMed Central

    Granobles Velandia, Claudia V.; Krüger, Alejandra; Parma, Yanil R.; Parma, Alberto E.; Lucchesi, Paula M. A.

    2012-01-01

    Shiga toxin-producing Escherichia coli (STEC) are characterized by the production of Shiga toxins (Stx) encoded by temperate bacteriophages. Stx production is linked to the induction of the phage lytic cycle. Several stx variants have been described and differentially associated with the risk of developing severe illness. The variant named stx2g was first identified in a STEC strain isolated from the faeces of healthy cattle. Analysis of stx2g-positive strains isolated from humans, animals, and environmental sources have shown that they have a close relationship. In this study, stx2g-positive STEC isolated from cattle were analyzed for phage and Stx production, with the aim to relate the results to differences observed in cytotoxicity. The presence of inducible phages was assessed by analyzing the bacterial growth/lysis curves and also by plaque assay. Bacterial growth curves in the absence of induction were similar for all isolates, however, notably differed among induced cultures. The two strains that clearly evidenced bacteriolysis under this condition also showed higher phage titers in plaque assays. However, only the phage plaques produced by one of these strains (FB 62) hybridized with a stx2-probe. Furthermore, the production of Stx was evaluated by enzyme immunoassay (EIA) and Western immunoblotting in overnight supernatants. By EIA, we detected Stx only in supernatants of FB 62, with a higher signal for induced than uninduced cultures. By immunoblotting, Stx2 could be detected after induction in all stx2g-positive isolates, but with lower amounts of Stx2B subunit in those supernatants where phages could not be detected. Taking into account all the results, several differences could be found among stx2g-positive strains. The strain with the highest cytotoxic titer showed higher levels of stx2-phages and toxin production by EIA, and the opposite was observed for strains that previously showed low cytotoxic titers, confirming that in stx2g-positive strains

  1. Differences in Shiga toxin and phage production among stx(2g)-positive STEC strains.

    PubMed

    Granobles Velandia, Claudia V; Krüger, Alejandra; Parma, Yanil R; Parma, Alberto E; Lucchesi, Paula M A

    2012-01-01

    Shiga toxin-producing Escherichia coli (STEC) are characterized by the production of Shiga toxins (Stx) encoded by temperate bacteriophages. Stx production is linked to the induction of the phage lytic cycle. Several stx variants have been described and differentially associated with the risk of developing severe illness. The variant named stx(2g) was first identified in a STEC strain isolated from the faeces of healthy cattle. Analysis of stx(2g)-positive strains isolated from humans, animals, and environmental sources have shown that they have a close relationship. In this study, stx(2g)-positive STEC isolated from cattle were analyzed for phage and Stx production, with the aim to relate the results to differences observed in cytotoxicity. The presence of inducible phages was assessed by analyzing the bacterial growth/lysis curves and also by plaque assay. Bacterial growth curves in the absence of induction were similar for all isolates, however, notably differed among induced cultures. The two strains that clearly evidenced bacteriolysis under this condition also showed higher phage titers in plaque assays. However, only the phage plaques produced by one of these strains (FB 62) hybridized with a stx(2)-probe. Furthermore, the production of Stx was evaluated by enzyme immunoassay (EIA) and Western immunoblotting in overnight supernatants. By EIA, we detected Stx only in supernatants of FB 62, with a higher signal for induced than uninduced cultures. By immunoblotting, Stx2 could be detected after induction in all stx(2g)-positive isolates, but with lower amounts of Stx2B subunit in those supernatants where phages could not be detected. Taking into account all the results, several differences could be found among stx(2g)-positive strains. The strain with the highest cytotoxic titer showed higher levels of stx(2)-phages and toxin production by EIA, and the opposite was observed for strains that previously showed low cytotoxic titers, confirming that in stx(2g

  2. Thermal diffusion and quench propagation in YBCO pancake coils wound with ZnO and Mylar insulations

    NASA Astrophysics Data System (ADS)

    Sumption, M. D.; Majoros, M.; Susner, M.; Lyons, D.; Peng, X.; Clark, C. F.; Lawless, W. N.; Collings, E. W.

    2010-07-01

    The thermal diffusion properties of several different kinds of YBCO (yttrium barium copper oxide) insulations and the quench properties of pancake coils made using these insulations were studied. Insulations investigated include Nomex, Kapton, and Mylar, as well as insulations based on ZnO, Zn2GeO4, and ZnO-Cu. Nomex, Kapton, and Mylar, chosen for their availability and ease of use, were obtained as thin ribbons, while the ZnO based insulations were chosen for their high thermal conductivity and were applied by a thin film technique. Initially, short stacks of YBCO conductors with interlayer insulation, epoxy, and a central heater strip were made and later measured as regards their thermal conductivity in liquid nitrogen. Subsequently, three different pancake coils were made. The first two were smaller, each using one meter total of YBCO tape present as four turns around a G-10 former. One of these smaller coils used Mylar insulation co-wound with the YBCO tape, the other used YBCO tape onto which ZnO based insulation had been deposited. One larger coil was made which used 12 total meters of ZnO insulated tape and had 45 turns. Temperature gradients were measured and thermal conductivities were estimated from these coils; the results obtained were compared to those for the short stacks. Quench propagation velocity measurements were performed on the coils (77 K, self-field) by applying a DC current and then using a heater pulse to initiate a quench. Radial NZP (normal zone propagation velocity) values (0.02-1 mm s - 1) were two orders of magnitude lower than axial values (~10-20 mm s - 1). Nevertheless, the quenches were generally seen to propagate radially within the coils, in the sense that any given turn in the coil is driven normal by the turn underneath it. This was due to the fact that while the radial NZP is much lower than the NZP along the conductor (~100 ×) the distance by which the normal zone must expand longitudinally is much larger than the distance

  3. Study on fatigue experiment for transverse butt welds under 2G and 3G weld positions

    NASA Astrophysics Data System (ADS)

    Kang, Sung-Wook; Park, Yong-Man; Jang, Beom-Seon; Jeon, Yu-Chul; Kim, Seong-Min

    2015-09-01

    Although the transverse butt weld method with ceramic backing strip has been widely used in various industrial fields for its fabricational convenience, it is rarely used in offshore industries since the fatigue strength of the weld joint has not been proved sufficiently. This study conducted fatigue tests for series of butt weld specimens with horizontal (2G) and vertical (3G) welding positions in order to verify the fatigue strength compared to S-N curve by DNV (Det Norske Veritas), IIW (International Institute of Welding) and Eurocode 3. The difference of the 2G specimens and the 3G specimens are investigated in terms of angular distortion and the effect on the fatigue strength are analyzed.

  4. Measurement Of Transverse Jc Profiles Of Coated Conductors Using A Magnetic Knife Of Permanent Magnets

    SciTech Connect

    Hanisch, J; Mueller, F M; Ashworth, S P; Coulter, J Y; Matias, Vlad

    2008-01-01

    The transverse J{sub c} distribution in YBCO coated conductors was measured nondestructively with high resolution using a 'magnetic knife' made of permanent magnets. 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 the sample in order to reveal the critical-current density distribution. The net resolution of this device is approximately 65 {mu}m, and the J{sub c} resolution is better than 0.5%. A Fourier series inversion process was used to determine the transverse J{sub c} distribution in the sample. The J{sub c} profile was correlated with other sample properties of coated conductors prepared by pulsed laser deposition. Because of its straight-forward and inexpensive design, this J{sub c} imaging technique can be a powerful tool for quality control in coated-conductor production.

  5. A temperature tracking SPICE2G.6 macromodel of the 6N134 optocoupler

    SciTech Connect

    Helms, C.; Perry, G.

    1992-09-01

    The popular circuit simulator platform SPICE2G.6 was chosen for the development of an advanced macromodel for the 6N134 optocoupler. The subcircuit model presented in this paper properly simulates DC and transient characteristics over the temperature range {minus}55 to 125{degrees}C using a single parameter set and the .TEMP statement available within SPICE. The model`s limitations and predictive accuracy relative to measured data are described.

  6. Parkinson Disease Phenotype in Ashkenazi Jews with and without LRRK2 G2019S mutations

    PubMed Central

    Alcalay, Roy N.; Mirelman, Anat; Saunders-Pullman, Rachel; Tang, Ming-X; Santana, Helen Mejia; Raymond, Deborah; Roos, Ernest; Orbe-Reilly, Martha; Gurevich, Tanya; Shira, Anat Bar; Weisz, Mali Gana; Yasinovsky, Kira; Zalis, Maayan; Thaler, Avner; Deik, Andres; Barrett, Matthew James; Cabassa, Jose; Groves, Mark; Hunt, Ann L.; Lubarr, Naomi; Luciano, Marta San; Miravite, Joan; Palmese, Christina; Sachdev, Rivka; Sarva, Harini; Severt, Lawrence; Shanker, Vicki; Swan, Matthew Carrington; Soto-Valencia, Jeannie; Johannes, Brooke; Ortega, Robert; Fahn, Stanley; Cote, Lucien; Waters, Cheryl; Mazzoni, Pietro; Ford, Blair; Louis, Elan; Levy, Oren; Rosado, Llency; Ruiz, Diana; Dorovski, Tsvyatko; Pauciulo, Michael; Nichols, William; Orr-Urtreger, Avi; Ozelius, Laurie; Clark, Lorraine; Giladi, Nir; Bressman, Susan; Marder, Karen S

    2013-01-01

    Background The phenotype of Parkinson disease (PD) patients with and without LRRK2 G2019S mutations is reported to be similar; however large uniformly evaluated series are lacking. Objective To characterize the clinical phenotype of Ashkenazi Jewish (AJ) PD carriers of the LRRK2 G2019S mutation. Methods We studied 553 AJ PD patients, including 65 patients who were previously reported, from three sites (two in New York and one in Tel-Aviv). GBA mutation carriers were excluded. Evaluations included the Montreal Cognitive Assessment (MoCA), the Unified Parkinson's Disease Rating Scale (UPDRS), the geriatric depression scale (GDS) and the non-motor symptoms (NMS) questionnaire. Regression models were constructed to test the association between clinical and demographic features and LRRK2 status (outcome) in 488 newly recruited participants. Results LRRK2 G2019S carriers (n=97) and non-carriers (n=391) were similar in age and age-at-onset of PD. Carriers had longer disease duration (8.6years versus 6.1years, p<0.001), were more likely to be women (51.5% versus 37.9%, p=0.015) and more often reported first symptoms in lower extremities (40.0% versus 19.2%, p<0.001). In logistic models adjusted for age, disease duration, gender, education, and site, carriers were more likely to have lower extremity onset (p<0.001), postural instability gait difficulty (PIGD, p=0.043) and persistent levodopa response for>5 years (p=0.042). Performance on UPDRS, MoCA, GDS and NMS did not differ by mutation status. Conclusion PD in AJ-LRRK2 G2019S mutation carriers is similar to idiopathic PD, but characterized by more frequent lower extremity involvement at onset and PIGD without the associated cognitive impairment. PMID:24243757

  7. Basic study of HTS magnet using 2G wires for maglev train

    NASA Astrophysics Data System (ADS)

    Ogata, M.; Miyazaki, Y.; Hasegawa, H.; Sasakawa, T.; Nagashima, K.

    2010-11-01

    There are several advantages by applying a high-temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the Ic measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of Ic characteristics for the small race track-shaped superconducting coil.

  8. Preliminary study of HTS magnet using 2G wires for maglev train

    NASA Astrophysics Data System (ADS)

    Ogata, Masafumi; Miyazaki, Yoshiki; Hasegawa, Hitoshi; Sasakawa, Takashi; Nagashima, Ken

    2010-06-01

    There are several advantages by applying a high temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the Ic measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of Ic characteristics for the small race track-shaped superconducting coil.

  9. Orientation of embedded Y2BaCuO5 particles within the YBa2Cu3Ox matrix in melt-textured YBCO superconductors

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Babu, N. Hari; Cardwell, D. A.; Mücklich, F.; Murakami, M.

    2005-03-01

    Automated electron backscatter diffraction (EBSD) was employed to study the local orientations of embedded Y2BaCuO5 (Y-211) particles within the YBa2Cu3Ox (Y-123) superconducting matrix of large grain, melt-textured Y-Ba-Cu-O (YBCO) samples. High-quality Kikuchi patterns were obtained, enabling automated mapping of the individual crystal orientations and a two-phase analysis of the samples. Investigations were performed on a variety of melt-textured YBCO samples, including samples with different element additions. We observe from the maps that the embedded Y-211 particles do not have any preferred orientation in melt-textured YBCO with (001) orientation, and that the YBCO growth is not altered for certain orientations of the Y-211 particles. In samples with (100) orientation, on the other hand, we observe only a small misorientation within the YBCO matrix, and the embedded Y-211 particles do not exhibit any texture. We can conclude from the EBSD maps obtained that the formation of small Y-211 particles does not disturb the Y-123 matrix growth, whereas the presence of large Y-211 particles leads, significantly, to the formation of subgrains.

  10. Photoemissive coating

    NASA Technical Reports Server (NTRS)

    Gange, R. A.

    1972-01-01

    Polystyrene coating is applied to holographic storage tube substrate via glow discharge polymerization in an inert environment. After deposition of styrene coating, antimony and then cesium are added to produce photoemissive layer. Technique is utilized in preparing perfectly organized polymeric films useful as single-crystal membranes.

  11. Evaluation of the invasion heat for the HTS current lead using YBCO

    NASA Astrophysics Data System (ADS)

    Endoh, R.; Kato, H.; Izumi, T.; Shiohara, Y.

    2003-10-01

    Current leads using high- TC superconductors (HTS current leads) are one of cryogenic key devices to assemble compact superconducting magnets such as applied for maglev trains etc. It is essential to evaluate effective thermal conductance through a HTS current lead package together with evaluating Joule heat and critical current for efficient design that has high current capacity and low heat invasion. We have designed the 500 A class HTS current lead package using a YBCO rod whose size is ∅ 3 × 30 mm, and developed an apparatus to measure its heat invasion. Temperature drop as a function of heat flow between the two ends of the package was measured by a conventional steady heat flow method. The quantity of heat invasion of the package under typical practical conditions, from 80 K hot end to 20 K cold end, was 163 mW. This value was simulated to the total value of 158 mW by counting contributions of all the component materials.

  12. The effect of disorder on the critical points in the vortex phase diagram of YBCO

    SciTech Connect

    Crabtree, G. W.; Kwok, W. K.; Paulius, L. M.; Petrean, A. M.; Olsson, R. J.; Karapetrov, G.; Tobos, V.; Moulton, W. G.

    2000-01-19

    The effect of line disorder induced by heavy ion irradiation and of point disorder induced by proton and electron irradiation on the upper and lower critical points in the vortex phase diagram of YBCO is presented. The authors find that dilute line disorder induces a Bose glass transition at low fields which is replaced at the lower critical point by first order melting at higher fields. Strong pinning point defects raise the lower critical point, while weak pinning point defects have little or no effect on the lower critical point. The upper critical point is lowered by point disorder, but raised by line disorder. First order melting is suppressed by point disorder in two ways, by lowering of the upper critical point only for weak point pins, or by merging of the upper and lower critical points for strong point pins. The differing responses of the upper and lower critical points to line and point disorder can be understood in a picture of transverse and longitudinal spatial fluctuations.

  13. C-axis critical current density of second-generation YBCO tapes.

    SciTech Connect

    Jia, Y.; Hua, J.; Crabtree, G. W.; Kwok, W. K.; Welp, U.; Malozemoff, A. P.; Rupich, M.; Fleshler, S.; Materials Science Division; American Superconductor Corp.

    2010-10-01

    We report on measurements of the temperature and field dependence of the c-axis critical current density (J{sub c}{sup c}) obtained on mesa structures that were patterned into the YBCO layer of second-generation HTS tapes. We find the J{sub c}{sup c}-values of {approx}4 kA cm{sup -2} at 77 K and self-field, corresponding to an unexpectedly high anisotropy in the critical current density J{sub c}{sup ab}/J{sub c}{sup c} of 500-600. C-axis current flow is expected to arise in applications such as the helically wound wires in HTS cables. A simple estimate is given of the fraction of tape width for such a c-axis flow; while in our samples this fraction is approximately 5% for a typical geometry, the fraction will grow linearly with increasing current density anisotropy and could affect the current-carrying ability of the tape.

  14. Self-assembled artificial pinning centres in thick YBCO superconducting films

    NASA Astrophysics Data System (ADS)

    Mikheenko, P.; Abell, J. S.; Sarkar, A.; Dang, V. S.; Awang Kechik, M. M.; Tanner, J. L.; Paturi, P.; Huhtinen, H.; Babu, N. Hari; Cardwell, D. A.; Crisan, A.

    2010-06-01

    Strong, artificial pinning centres are required in superconducting films of large thickness for power applications in high magnetic fields. One of the methods for the introduction of pinning centres in such films is substrate decoration, i.e., growing nanoscale islands of certain materials on the substrate prior to the deposition of the superconducting film. Two other methods are building up a layered distribution of a second phase and homogeneous incorporation of second phase inclusions from a compositional target. In this paper, we compare the effectiveness of these methods in terms of the type of the self-assembly of nanoparticles. The comparison is made over a large set of YBa2Cu3O7 films of thickness up to 6.6 μm deposited with Au, Ag, Pd, LaNiO3, PrBa2Cu3O7, YBCO, BaZrO3 and Gd2Ba4CuWOy nanoparticles. It is found that substrate-decoration self-assembly is able to provide higher critical current in low magnetic field than the incorporation of homogeneous second phase in the sample microstructure. By specific modification of substrate decoration we achieved the self-field critical current per centimetre of width of 896 A/cm at 77.3 K and 1620 A/cm at 65 K in a film of thickness of 4.8 μm.

  15. Vortex dynamics of 250 MeV Ag ions irradiated YBCO films

    NASA Astrophysics Data System (ADS)

    Khatua, Sanghamitra; Kumar, Ravi; Mishra, P. K.; Sahni, V. C.; Pinto, R.

    YBCO thin films with c-axis orientation were grown in-situ by KrF laser on LaAIO 3 substrate. The films were irradiated with 250 MeV Ag ions at doses equivalent to B φ ranging from 1 T to 4 T. Critical currents were measured using SQUID magnetometer with field parallel to columnar defects. There is a marked enhancement of vortice pinning due to generation of additional pinning centres. There seems to be an upper limit to the irradiation doses beyond which there is a 'smearing effect' on Jc. We also find a shift in Irreversibility Line towards higher field which is attributed to better pinning induced by columnar defects. Defect production is examined in the framework of "Coulomb explosion" model and the consequences are analysed in terms of defect-induced behaviour within the purview of models such as "Bean model", 'Exponential model' and "Vortex Glass" model. We point out that the 'stress model' provides a qualitative explanation for the reduced Tc and a broad transition at high fluence.

  16. Irreversible properties of YBCO thick films deposited by liquid phase epitaxy on single crystalline substrates

    NASA Astrophysics Data System (ADS)

    Vostner, A.; Tönies, S.; Weber, H. W.; Cheng, Y. S.; Kurumovic, A.; Evetts, J. E.; Mennema, S. H.; Zandbergen, H. W.

    2003-10-01

    We report on the field and temperature dependence of the critical transport current density Jc, the angular dependence of the transport current at various external magnetic fields and the irreversibility fields in YBa2Cu3O7-delta (Y-123) thick films prepared by liquid phase epitaxy (LPE). A comparison of the irreversible properties between specimens produced with and without silver additions to the melt is also presented. Transmission electron microscopy (TEM) was employed to obtain information on the correlation between the transport properties and the microstructure. The samples were deposited either directly on NdGaO3 (NGO) or on seeded (100) MgO substrates, where a 200 nm thin YBCO film deposited by pulsed laser deposition (PLD) acts as seed layer for the LPE process. The final thickness of the Y-123 layer is of the order of 1 µm for the NGO and between 2 and 10 µm for the MgO samples. The critical current densities reach 3 × 109 A m-2 at zero field and 77 K in the best case.

  17. Superconducting YBCO thin film on multicrystalline Ag film evaporated on MgO substrate

    NASA Astrophysics Data System (ADS)

    Azoulay, Jacob; Verdyan, Armen; Lapsker, Igor

    Superconducting YBa 2Cu 3O 7-δ films were grown by resistive evaporation on multicrystalline silver film which was evaporated on MgO substrate. A simple inexpensive vacuum system equipped with resistively heated boat was used for the whole process. Silver film was first evaporated on MgO substrate kept at 400°C during the evaporation after which with no further annealing a precursor mixture of yttrium small grains and Cu and BaF2 in powder form weighed in the atomic proportion to yield stoichiometric YBa 2Cu 3O 7 was evaporated. The films thus obtained were annealed at 740°C under low oxygen partial pressure of about 1Pa for 30 minutes to form the superconducting phase. X-ray diffraction and scanning electron microscopy techniques were used for texture and surface analysis. Electrical properties were determined using a standard dc four-probe for electrical measurements. The physical and electrical properties of the YBCO films are discussed in light of the fact that X-ray diffraction measurements done on the silver film have revealed a multicrystalline structure

  18. ENSYSTROB - Design, manufacturing and test of a 3-phase resistive fault current limiter based on coated conductors for medium voltage application

    NASA Astrophysics Data System (ADS)

    Elschner, S.; Kudymow, A.; Brand, J.; Fink, S.; Goldacker, W.; Grilli, F.; Noe, M.; Vojenciak, M.; Hobl, A.; Bludau, M.; Jänke, C.; Krämer, S.; Bock, J.

    2012-11-01

    Within the German project ENSYSTROB a 3-phase resistive fault current limiter for medium voltage applications (12 kV, 533 Arms) was designed, built, tested and installed in the grid for a one year’s field test. The superconducting modules are made of YBCO coated conductors and replace the modules of an already successfully tested limiter on the basis of BSCCO 2212 bulk material. The components are multifilar spirals equipped with pairs of 12 mm wide YBCO tapes. The single components were characterized with respect to critical current, AC losses and limitation behavior under all possible operation conditions. The finally mounted limiter was successfully tested with respect to high voltage and limitation according to the standards of the customer. It is now installed and operating in its field test location. Finally we give a first comparison of both materials with respect to the different operational aspects.

  19. Regulatory Aspects of Coatings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter gives a history of the development and uses of edible coating regulations, detailed chapters on coating caracteristics, determination of coating properties, methods for making coatings, and discription of coating film formers (polysaccharieds, lipids, resins, proteins). The chapter also...

  20. Serotonin synthesis rate and the tryptophan hydroxylase-2: G-703T polymorphism in social anxiety disorder.

    PubMed

    Furmark, Tomas; Marteinsdottir, Ina; Frick, Andreas; Heurling, Kerstin; Tillfors, Maria; Appel, Lieuwe; Antoni, Gunnar; Hartvig, Per; Fischer, Håkan; Långström, Bengt; Eriksson, Elias; Fredrikson, Mats

    2016-10-01

    It is disputed whether anxiety disorders, like social anxiety disorder, are characterized by serotonin over- or underactivity. Here, we evaluated whether our recent finding of elevated neural serotonin synthesis rate in patients with social anxiety disorder could be reproduced in a separate cohort, and whether allelic variation in the tryptophan hydroxylase-2 (TPH2) G-703T polymorphism relates to differences in serotonin synthesis assessed with positron emission tomography. Eighteen social anxiety disorder patients and six healthy controls were scanned during 60 minutes in a resting state using positron emission tomography and 5-hydroxy-L-[β -(11)C]tryptophan, [(11)C]5-HTP, a substrate of the second enzymatic step in serotonin synthesis. Parametric images were generated, using the reference Patlak method, and analysed using Statistical Parametric Mapping (SPM8). Blood samples for genotyping of the TPH2 G-703T polymorphism were obtained from 16 social anxiety disorder patients (T carriers: n=5, GG carriers: n=11). A significantly elevated [(11)C]5-HTP accumulation rate, indicative of enhanced decarboxylase activity and thereby serotonin synthesis capacity, was detected in social anxiety disorder patients compared with controls in the hippocampus and basal ganglia nuclei and, at a more lenient (uncorrected) statistical threshold, in the amygdala and anterior cingulate cortex. In patients, the serotonin synthesis rate in the amygdala and anterior cingulate cortex was significantly elevated in TPH2 T carriers in comparison with GG homozygotes. Our results support that social anxiety disorder entails an overactive presynaptic serotonergic system that, in turn, seems functionally influenced by the TPH2 G-703T polymorphism in emotionally relevant brain regions.

  1. Serotonin synthesis rate and the tryptophan hydroxylase-2: G-703T polymorphism in social anxiety disorder.

    PubMed

    Furmark, Tomas; Marteinsdottir, Ina; Frick, Andreas; Heurling, Kerstin; Tillfors, Maria; Appel, Lieuwe; Antoni, Gunnar; Hartvig, Per; Fischer, Håkan; Långström, Bengt; Eriksson, Elias; Fredrikson, Mats

    2016-10-01

    It is disputed whether anxiety disorders, like social anxiety disorder, are characterized by serotonin over- or underactivity. Here, we evaluated whether our recent finding of elevated neural serotonin synthesis rate in patients with social anxiety disorder could be reproduced in a separate cohort, and whether allelic variation in the tryptophan hydroxylase-2 (TPH2) G-703T polymorphism relates to differences in serotonin synthesis assessed with positron emission tomography. Eighteen social anxiety disorder patients and six healthy controls were scanned during 60 minutes in a resting state using positron emission tomography and 5-hydroxy-L-[β -(11)C]tryptophan, [(11)C]5-HTP, a substrate of the second enzymatic step in serotonin synthesis. Parametric images were generated, using the reference Patlak method, and analysed using Statistical Parametric Mapping (SPM8). Blood samples for genotyping of the TPH2 G-703T polymorphism were obtained from 16 social anxiety disorder patients (T carriers: n=5, GG carriers: n=11). A significantly elevated [(11)C]5-HTP accumulation rate, indicative of enhanced decarboxylase activity and thereby serotonin synthesis capacity, was detected in social anxiety disorder patients compared with controls in the hippocampus and basal ganglia nuclei and, at a more lenient (uncorrected) statistical threshold, in the amygdala and anterior cingulate cortex. In patients, the serotonin synthesis rate in the amygdala and anterior cingulate cortex was significantly elevated in TPH2 T carriers in comparison with GG homozygotes. Our results support that social anxiety disorder entails an overactive presynaptic serotonergic system that, in turn, seems functionally influenced by the TPH2 G-703T polymorphism in emotionally relevant brain regions. PMID:27189957

  2. 2G HTS wires made on 30 μm thick Hastelloy substrate

    NASA Astrophysics Data System (ADS)

    Sundaram, A.; Zhang, Y.; Knoll, A. R.; Abraimov, D.; Brownsey, P.; Kasahara, M.; Carota, G. M.; Nakasaki, R.; Cameron, J. B.; Schwab, G.; Hope, L. V.; Schmidt, R. M.; Kuraseko, H.; Fukushima, T.; Hazelton, D. W.

    2016-10-01

    REBCO (RE = rare earth) based high temperature superconducting (HTS) wires are now being utilized for the development of electric and electromagnetic devices for various industrial, scientific and medical applications. In the last several years, the increasing efforts in using the so-called second generation (2G) HTS wires for some of the applications require a further increase in their engineering current density (J e). The applications are those typically related to high magnetic fields where the higher J e of a REBCO wire, in addition to its higher irreversibility fields and higher mechanical strength, is already a major advantage over other superconducting wires. An effective way to increase the J e is to decrease the total thickness of a wire, for which using a thinner substrate becomes an obvious and attractive approach. By using our IBAD-MOCVD (ion beam assisted deposition-metal organic chemical vapor deposition) technology we have successfully made 2G HTS wires using a Hastelloy® C276 substrate that is only 30 μm in thickness. By using this thinner substrate instead of the typical 50 μm thick substrate and with a same critical current (I c), the J e of a wire can be increased by 30% to 45% depending on the copper stabilizer thickness. In this paper, we report the fabrication and characterization of the 2G HTS wires made on the 30 μm thick Hastelloy® C276 substrate. It was shown that with the optimization in the processing protocol, the surface of the thinner Hastelloy® C276 substrate can be readily electropolished to the quality needed for the deposition of the buffer stack. Same in the architecture as that on the standard 50 μm thick substrate, the buffer stack made on the 30 μm thick substrate showed an in-plane texture with a Δϕ of around 6.7° in the LaMnO3 cap layer. Low-temperature in-field transport measurement results suggest that the wires on the thinner substrate had achieved equivalent superconducting performance, most importantly the I

  3. Method for Determining Local Current Density in 2G HTS Tapes

    NASA Astrophysics Data System (ADS)

    Bludova, A. I.

    Practically important problem is to determine the density and direction of 2G HTS induced currents at each point on the tape in order to examine its local deviations. This problem is resolved indirectly by spatial measurement of generated magnetic field with a scanning Hall sensor at a given height above the tape surface. Current density is subsequently determined by the Biot-Savart law inversion in Fourier domain. Tikhonov regularization is used in order to increase precision. Method is verified with the model current density reconstruction. Optimal calculation parameters and resulting precision are described.

  4. In-situ deposition of YBCO high-Tc superconducting thin films by MOCVD and PE-MOCVD

    NASA Technical Reports Server (NTRS)

    Zhao, J.; Noh, D. W.; Chern, C.; Li, Y. Q.; Norris, P. E.; Kear, B.; Gallois, B.

    1991-01-01

    Metal-Organic Chemical Vapor Deposition (MOCVD) offers the advantages of a high degree of compositional control, adaptability for large scale production, and the potential for low temperature fabrication. The capability of operating at high oxygen partial pressure is particularly suitable for in situ formation of high temperature superconducting (HTSC) films. Yttrium barium copper oxide (YBCO) thin films having a sharp zero-resistance transition with T(sub c) greater than 90 K and J(sub c) of approximately 10(exp 4) A on YSZ have been prepared, in situ, at a substrate temperature of about 800 C. Moreover, the ability to form oxide films at low temperature is very desirable for device applications of HTSC materials. Such a process would permit the deposition of high quality HTSC films with a smooth surface on a variety of substrates. Highly c-axis oriented, dense, scratch resistant, superconducting YBCO thin films with mirror-like surfaces have been prepared, in situ, at a reduced substrate temperature as low as 570 C by a remote microwave-plasma enhanced metal-organic chemical vapor deposition (PE-MOCVD) process. Nitrous oxide was used as a reactant gas to generate active oxidizing species. This process, for the first time, allows the formation of YBCO thin films with the orthorhombic superconducting phase in the as-deposited state. The as-deposited films grown by PE-MOCVD show attainment of zero resistance at 72 K with a transition width of about 5 K. MOCVD was carried out in a commercial production scale reactor with the capability of uniform deposition over 100 sq cm per growth run. Preliminary results indicate that PE-MOCVD is a very attractive thin film deposition process for superconducting device technology.

  5. In Situ deposition of YBCO high-T(sub c) superconducting thin films by MOCVD and PE-MOCVD

    NASA Technical Reports Server (NTRS)

    Zhao, J.; Noh, D. W.; Chern, C.; Li, Y. Q.; Norris, P.; Gallois, B.; Kear, B.

    1990-01-01

    Metalorganic Chemical Vapor Deposition (MOCVD) offers the advantages of a high degree of compositional control, adaptability for large scale production, and the potential for low temperature fabrication. The capability of operating at high oxygen partial pressure is particularly suitable for in situ formation of high temperature superconducting (HTSC) films. Yttrium barium copper oxide (YBCO) thin films having a sharp zero-resistance transition with T( sub c) greater than 90 K and Jc approx. 10 to the 4th power A on YSZ have been prepared, in situ, at a substrate temperature of about 800 C. Moreover, the ability to form oxide films at low temperature is very desirable for device applications of HTSC materials. Such a process would permit the deposition of high quality HTSC films with a smooth surface on a variety of substrates. Highly c-axis oriented, dense, scratch resistant, superconducting YBCO thin films with mirror-like surfaces have been prepared, in situ, at a reduced substrate temperature as low as 570 C by a remote microwave-plasma enhanced metalorganic chemical vapor deposition (PE-MOCVD) process. Nitrous oxide was used as a reactant gas to generate active oxidizing species. This process, for the first time, allows the formation of YBCO thin films with the orthorhombic superconducting phase in the as-deposited state. The as-deposited films grown by PE-MOCVD show attainment of zero resistance at 72 K with a transition width of about 5 K. MOCVD was carried out in a commercial production scale reactor with the capability of uniform deposition over 100 sq cm per growth run. Preliminary results indicate that PE-MOCVD is a very attractive thin film deposition process for superconducting device technology.

  6. IRS-2 G1057D polymorphism in Turkish patients with colorectal cancer

    PubMed Central

    Celik, Sevim Karakas; Kucuk, Meral Urhan; Yalin, Erdinc; Ozkal, S. Sebnem; Ates, Cengiz; Berkoz, Mehmet; Yalin, Serap; Ates, Nurcan Aras

    2014-01-01

    Introduction Gene polymorphisms have a broad range of analysis, but are of particular use in molecular medicine due to their potential in revealing the genetic tendency in diseases such as cancer, heart attack etc. These studies basically depend on mutations that can be detected by proper techniques. The genes coding the insulin receptor substrate (IRS) proteins are among the most widely analysed polymorphisms in various cancer types, in which a G1057D mutation is seen. Aim To determine the risk of colon cancer by analysing the IRS-2 gene polymorphism in Turkish patients. Material and methods A total of 161 newly diagnosed colorectal cancer patients were analysed and compared to 197 unrelated healthy controls. A polymerase chain reaction-based restriction fragment length polymorphism method was carried out. Results No differences were observed between the patient and control groups for both allele and genotype frequencies of the IRS-2 G1057D gene. Conclusions Our results demonstrated that IRS-2 G1057D polymorphism is not associated with colorectal cancer in the Turkish population. This research is a preliminary and original study in Turkish patients with colorectal cancer. It also provides population-level genetic data on IRS-2 in the Turkish population. Further studies should be performed on larger number of patients and controls for more reliable results about the genetic tendency in colorectal cancer in Turkey. The study is a collaborative work of different universities and scientists. PMID:25061488

  7. Temperature measurements along the principal Hugoniot for 0.2g/cc aerogel foam

    NASA Astrophysics Data System (ADS)

    Benage, John; Taccetti, Martin; Luo, Shengnian; Lanier, Nick; Falk, Katerina; Schmidt, Derek; Crockett, Scott; Fryer, Chris

    2012-10-01

    Aerogel (SiO2) foams are used in a variety of HED experiments such as radiation flow experiments and more recently as a low-density shock standard for WDM equation of state experiments. Many of these experiments can be sensitive to the equation of state (EOS) of the foam. Despite recent very successful Hugoniot measurements of 0.2 g/cc aerogel foam, the temperature of these foams at a given pressure has not been measured and many EOS models for foams ignore important physics, thus predicting very different temperatures for a given condition. We have completed a set of temperature measurements of 0.2 g/cc aerogel foam shocked along the principal Hugoniot from 100 to 400 GPa. The experiments were done using 12 beams at the Omega laser facility to launch strong steady shocks into the foam targets. The temperature of the shocked foam was determined from measurements using the streaked optical pyrometer (SOP). The range of pressures covered established the behavior of the temperature through the important dissociation and initial ionization range. Equation of state models, where available, are compared to the data.

  8. Manufacturing and test of 2G-HTS coils for rotating machines: Challenges, conductor requirements, realization

    NASA Astrophysics Data System (ADS)

    Oomen, Marijn; Herkert, Werner; Bayer, Dietmar; Kummeth, Peter; Nick, Wolfgang; Arndt, Tabea

    2012-11-01

    We investigate the use of 2nd-generation High-Temperature Superconductors (2G-HTSs) in the rotors of electrical motors and generators. For these devices the conductor must be wound into robust impregnated coils, which are operated in vacuum at temperatures around 30 K, in strong magnetic fields of about 2T. Differences in thermal contraction between the coil former, conductor constituents, impregnation resin, bandage and heat-sink materials (assembled at room temperature) cause mechanical stresses at operating temperature. Rotating-machine operation adds Lorentz forces and challenging centripetal accelerations up to thousands of g. Second generation-HTS conductors withstand large tensile stresses in axial direction and compression in normal direction. However, shear stresses, axial compression, and tension normal to the conductor can cause degradation in superconducting properties. Such stresses can be mitigated by correct choice of materials, coil lay-out and manufacturing process. A certain stress level will remain, which the conductor must withstand. We have manufactured many impregnated round and race-track coils, using different 2G-HTS conductors, and tested them at temperatures from 25 K to 77 K. Degradation of the superconductor in early coils was traced to the mentioned differences in thermal contraction, and was completely avoided in coils produced later. We will discuss appropriate coil-winding techniques to assure robust and reliable superconductor performance.

  9. Protective Coating

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Inorganic Coatings, Inc.'s K-Zinc 531 protective coating is water-based non-toxic, non-flammable and has no organic emissions. High ratio silicate formula bonds to steel, and in 30 minutes, creates a very hard ceramic finish with superior adhesion and abrasion resistance. Improved technology allows application over a minimal commercial sandblast, fast drying in high humidity conditions and compatibility with both solvent and water-based topcoats. Coating is easy to apply and provides long term protection with a single application. Zinc rich coating with water-based potassium silicate binder offers cost advantages in materials, labor hours per application, and fewer applications over a given time span.

  10. Noise measurements in a composite niobium/YBCO SQUID and determination of the magnetic noise by direct measurement

    SciTech Connect

    Harrop, S.P.; Keene, M.N.; Muirhead, C.M.; Gough, C.E. )

    1991-03-01

    We have measured the noise performance of a composite niobium/YBCO point contact 2-hole SQUID, at 4.2 K in both rf and dc bias modes. The noise was measured by a technique which allowed the component which was flux noise to be measured. The flux noise was found to be the same in both bias modes. A direct measurement of the noise in a single hole in the same sample was made as a function of temperature and was found to display two peaks. Possible causes are discussed in this paper.

  11. Effects of 2 G on adiposity, leptin, lipoprotein lipase, and uncoupling protein-1 in lean and obese Zucker rats

    NASA Technical Reports Server (NTRS)

    Warren, L. E.; Horwitz, B. A.; Hamilton, J. S.; Fuller, C. A.

    2001-01-01

    Male Zucker rats were exposed to 2 G for 8 wk to test the hypothesis that the leptin regulatory pathway contributes to recovery from effects of 2 G on feeding, growth, and nutrient partitioning. After initial hypophagia, body mass-independent food intake of the lean rats exposed to 2 G surpassed that of the lean rats maintained at 1 G, but food intake of the obese rats exposed to 2 G remained low. After 8 wk at 2 G, body mass and carcass fat were less in both genotypes. Leptin and percent fat were lower in lean rats exposed to 2 G vs. 1 G but did not differ in obese rats exposed to 2 G vs. 1 G. Although exposure to 2 G did not alter uncoupling protein-1 levels, it did elicit white fat pad-specific changes in lipoprotein lipase activity in obese but not lean rats. We conclude that 2 G affects both genotypes but that the lean Zucker rats recover their food intake and growth rate and retain "normal" lipoprotein lipase activity to a greater degree than do the obese rats, emphasizing the importance of a functional leptin regulatory pathway in this acclimation.

  12. Characterization of MgO substrates for growth of epitaxial YBCO thin films

    NASA Astrophysics Data System (ADS)

    Du, J.; Gnanarajan, S.; Bendavid, A.

    2005-08-01

    YBCO films were grown on magnesium oxide (MgO) substrates for fabricating step-edge junction SQUIDs and other Josephson junction-based devices. In-plane 45° grain misorientation was frequently observed in films grown on degraded or contaminated MgO substrates. The appearance of these misoriented grains results in a decrease of the thin-film critical-current density and reduces the device yield. In this work, we investigated the chemical properties of MgO substrates with various surface conditions due to different substrate preparation methods and environmental degradation, by using x-ray photoelectron spectroscopy (XPS). The XPS characteristics of the surface are compared before and after a thermal annealing at 760 °C resembling the thin-film deposition heating cycle. The MgO substrates, after lithographic processing or only weeks of exposure to the laboratory environment, showed surface degradation characterized by the presence of hydroxyl groups, carbonate, and other possible carbon compounds such as bicarbonate, alcohols and carboxyl. Heating of the substrates to 760 °C improves the surface quality to a certain degree with the removal of some of the above contaminants, but is not sufficient to recover the MgO surfaces. A final Ar ion-beam etch cleaning process at low ion energy proved to be very effective in refreshing the MgO substrate surface that had been degraded due to lithographic processing or storage. Films grown on MgO with this pre-treatment showed perfect grain alignment and high critical-current densities.

  13. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    NASA Astrophysics Data System (ADS)

    Schoenhuber, P.; Moon, F. C.

    1995-04-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  14. Magnetism in EuBCO and YBCO vortex states near and below Tc

    NASA Astrophysics Data System (ADS)

    Schwartz, R.; Browne, M. C.; Boekema, C.

    2012-02-01

    By means of MaxEnt-μSR [1] analysis, we investigate transverse field μSR data [2] of EuBa2Cu3O7-δgEuBCO; Tc = 93 K). Our focus is on a temperature interval near Tc to search for precursor effects, [3] and for predicted [4a] pseudogap loop currents above and below Tc, already observed [4b] above Tc for GdBCO. Further, we continue to study the field-direction dependence of the predicted [5a] and observed [5b] antiferromagnetism (AF) below 0.5Tc for the vortex states in c-axis-oriented YBCO. This AF in and near the vortex cores is likely three-dimensional. In sum, magnetic roots of cuprate superconductivity are well plausible. Research is supported by LANL-DOE, REU-NSF and AFC. [4pt] [1] C Boekema and MC Browne, AIP Conf Proc #1073 (2008) 260.[0pt] [2] DW Cooke et al, Phys Rev B 39 (1989) 2748.[0pt] [3] B Aguilar, C Boekema et al, Bull Am Phys Soc 37 (1992).[0pt] [4a] CM Varma, Phys Rev Lett 83 (1999) 3538.[0pt] [4b] T Songatikamas et al, J Supercond & Novel Magn 23 (2010) 793.[0pt] [5a] S-C Zhang, Science 275 (1997) 1089; H-D Chen et al, Phys Rev B70 (2004) 024516.[0pt] [5b] C. Boekema et al, J Phys Conf Series, 150 (2009) 052022. http://jpcs.iop.org/LT25

  15. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    NASA Technical Reports Server (NTRS)

    Schoenhuber, P.; Moon, F. C.

    1995-01-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  16. Onset of Superconductivity in YBCO in Very High Fields from ^17O and ^63Cu NMR

    NASA Astrophysics Data System (ADS)

    Halperin, William

    2000-03-01

    We have used NMR to study the onset of superconductivity in near optimally doped YBCO in fields from 1 to 27 T. We have compared Knight shift(^17O), spin-spin relaxation measurements(^17O), and spin lattice relaxation measurements (^63Cu and ^17O). The measurements have been performed as a function of temperature above and below the transition region. The Knight shift can be measured with considerable precision directly giving the Pauli spin susceptibility. We show that the onset of superconductivity in a magnetic field is really a crossover region from normal state behavior to a vortex liquid for which we determine a H-T phase diagram up to high field. The relaxation measurements show clear evidence for the opening of a pseudo gap near 100 K in the transition region. The different NMR experiments are sensitive to the susceptibility dependence on wave vector from different regions of the Brillouin zone indicating possible origins of such a gap including superconducting fluctuations or a gap in the spin excitation spectrum. Magnetic field dependence of the data allows discrimination. Intercomparison between samples near optimal doping as well as the work from other laboratories will be made. This work was performed in collaboration with V. F. Mitović, H. N. Bachman, E. E. Sigmund, M. Eschrig, J. A. Sauls, A. P. Reyes, P. Kuhns, and W. G. Moulton. Work at Northwestern University is supported by the NSF (DMR 91-20000) through the Science and Technology Center for Superconductivity. The NHMFL is supported through the NSF and the state of Florida.

  17. Preliminary characterization of ST2G: Solar thermionic-thermoelectric generator for concentrating systems

    NASA Astrophysics Data System (ADS)

    Bellucci, Alessandro; Calvani, Paolo; Cappelli, Emilia; Orlando, Stefano; Sciti, Diletta; Yogev, Ronen; Kribus, Abraham; Trucchi, Daniele M.

    2015-06-01

    An innovative conversion module (CM) for concentrating solar power applications, named ST2G (Solar Thermionic-Thermoelectric Generator), has been developed and fabricated. The new technology is based on a solid-state converter that works at temperatures up to 1000 °C and exploits a double conversion stage: a thermionic stage and a thermoelectric one, connected thermally in series. Potentially, the CM could reach a combined solar energy-to-electrical efficiency larger than 30%, producing also additional thermal energy to be exploited as a co-generation. Different prototypes have been fabricated and the discussion on the technological key-points has been reported, relating them to the physical requirements necessary for an efficient conversion mechanism. The preliminary results obtained at a lab-level are here discussed, indicating low electrical power output, but also how to increase the performance by solving the identified issues.

  18. Influence of Proton Irradiation on Angular Dependence of Second Generation (2G)HTS

    SciTech Connect

    Shiroyanagi, Y.; Greene, G.; Gupta, R.; Sampson, W.

    2011-05-01

    In the Facility for Rare Isotope Beams (FRIB) the quadrupoles in the fragment separator are exposed to very high radiation and heat loads. High Temperature Superconductors (HTS) are a good candidate for these magnets because they can be used at {approx}30-50 K and tolerate higher heat generation than Nb-Ti magnets. Radiation damage studies of HTS wires are crucial to ensure that they will survive in a high radiation environment. HTS wires from two vendors were studied. Samples of 2G HTS wires from SuperPower and American Superconductor (ASC) were irradiated with a 42 {mu}A, 142 MeV proton beam from the Brookhaven Linac Isotope Producer (BLIP). The angular dependence of the critical current was measured in magnetic fields at 77K.

  19. Design, fabrication and testing of a dipole magnet made with 2G HTS wire

    NASA Astrophysics Data System (ADS)

    Bogdanov, I. V.; Kozub, S. S.; Sytnik, V. V.; Terskiy, I. S.; Tkachenko, L. M.; Trusov, O. V.; Shirshov, L. S.; Smirnov, V. M.; Shuvalov, V. I.; Shcherbakov, P. A.; Molodyk, A. A.; Lee, S. R.; Samoilenkov, S. V.

    2016-10-01

    An HTS dipole magnet with a 1 T (at 77 K) central magnetic field in a 40 × 80 mm2 aperture has been designed, fabricated and tested. The magnet coils were wound with SuperOx 2G HTS wire. The paper describes the magnet design, properties of the magnet materials, and results of calculations and measurements. The central field in the dipole reached 1.12 T at 77 K and 1.66 T at 65 K. In a liquid helium bath the maximum input current of 847 A was limited by the capacity of the power supply, and in that case the central field was 3.03 T. The measurement data were in good agreement with the calculation results.

  20. Neuropsychological performance in LRRK2 G2019S carriers with Parkinson’s disease

    PubMed Central

    Alcalay, Roy N.; Mejia-Santana, Helen; Mirelman, Anat; Saunders-Pullman, Rachel; Raymond, Deborah; Palmese, Christina; Caccappolo, Elise; Ozelius, Laurie; Orr-Urtreger, Avi; Clark, Lorraine; Giladi, Nir; Bressman, Susan; Marder, Karen

    2014-01-01

    Background Ashkenazi Jewish (AJ) LRRK2 carriers are more likely to manifest the postural instability gait difficulty (PIGD) motor phenotype than non-carriers but perform similarly to non-carriers on cognitive screening tests. Objective To compare the cognitive profiles of AJ with Parkinson’s disease (PD) with and without LRRK2 G2019S mutations using a comprehensive neuropsychological battery. Methods We administered a neuropsychological battery to PD participants in the Michael J. Fox Foundation AJ consortium. Participants (n=236) from Beth Israel Medical Center, NY, Columbia University Medical Center, NY and Tel Aviv Medical Center, Israel included 116 LRRK2 G2019S carriers and 120 non-carriers. Glucocerbrosidase mutation carriers were excluded. We compared performance on each neuropsychological test between carriers and non-carriers. Participants in New York (n=112) were evaluated with the entire battery. Tel Aviv participants (n=124) were evaluated on attention, executive function and psychomotor speed tasks. The association between G2019S mutation status (predictor) and each neuropsychological test (outcome) was assessed using linear regression models adjusted for PIGD motor phenotype, site, sex, age, disease duration, education, Unified Parkinson’s Disease Rating Scale (UPDRS) Part III, levodopa equivalent dose, and Geriatric Depression Score (GDS). Results Carriers had longer disease duration (p<0.001) and were more likely to manifest the PIGD phenotype (p=0.024). In adjusted regression models, carriers performed better than non-carriers in Stroop Word Reading (p<0.001), Stroop Interference (p=0.011) and Category Fluency (p=0.026). Conclusion In AJ-PD, G2019S mutation status is associated with better attention (Stroop Word Reading), executive function (Stroop Interference) and language (Category Fluency) after adjustment for PIGD motor phenotype. PMID:25434972

  1. Architecture for coated conductors

    DOEpatents

    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.

  2. Studies of Solution Deposited Cerium Oxide Thin Films on Textured Ni-Alloy Substractes for YBCO Superconductor

    SciTech Connect

    Stewart, Erin L; Bhuiyan, Md S; Sathyamurthy, Srivatsan; Paranthaman, Mariappan Parans

    2006-01-01

    Cerium oxide (CeO2) buffer layers play an important role for the development of YBa2Cu3O7-x (YBCO) based superconducting tapes using the rolling assisted biaxially textured substrates (RABiTS) approach. The chemical solution deposition (CSD) approach has been used to grow epitaxial CeO2 films on textured Ni-3 a 4% W alloy substrates with various starting precursors of ceria. Precursors such as cerium acetate, cerium acetylacetonate, cerium 2-ethylhexanoate, cerium nitrate, and cerium trifluoroacetate were prepared in suitable solvents. The optimum growth conditions for these cerium precursors were Ar-4% H2 gas processing atmosphere, solution concentration levels of 0.2-0.5 M, a dwell time of 15 min, and a process temperature range of 1050-1150 degrees C. X-ray diffraction, AFM, SEM, and optical microscopy were used to characterize the CeO2 films. Highly textured CeO2 layers were obtained on Ni-W substrates with both cerium acetate and cerium acetylacetonate as starting precursors. YBCO films with a Jc of 1.5 MA/cm2 were obtained on cerium acetylacetonate-based CeO2 films with sputtered YSZ and CeO2 cap layers.

  3. The mechanism of sputter-induced epitaxy modification in YBCO (001) films grown on MgO (001) substrates

    SciTech Connect

    Huang, Y.; Vuchic, B.V.; Carmody, M.; Baldo, P.M.; Merkle, K.L.; Buchholz, D.B.; Mahajan, S.; Lei, J.S.; Markworth, P.R.; Chang, R.P.; Marks, L.D.

    1998-12-01

    The sputter-induced epitaxy change of in-plane orientation occurring in YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (001) thin films grown on MgO (001) substrates by pulsed organo-metallic beam epitaxy (POMBE) is investigated by a series of film growth and characterization experiments, including RBS and TEM. The factors influencing the orientation change are systematically studied. The experimental results suggest that the substrate surface morphology change caused by the ion sputtering and the Ar ion implantation in the substrate surface layer are not the major factors that affect the orientation change. Instead, the implantation of W ions, which come from the hot filament of the ion gun, and the initial Ba deposition layer in the YBCO film growth play the most important roles in controlling the epitaxy orientation change. Microstructure studies show that a Ba{sub x}Mg{sub 1{minus}x}O buffer layer is formed on top of the sputtered substrate surface due to Ba diffusion into the W implanted layer. It is believed that the formation of this buffer layer relieves the large lattice mismatch and changes the YBCO film from the 45{degree} oriented growth to the 0{degree} oriented growth. {copyright} {ital 1998 Materials Research Society.}

  4. Design of a cryogenic system for a 20m direct current superconducting MgB2 and YBCO power cable

    NASA Astrophysics Data System (ADS)

    Cheadle, Michael J.; Bromberg, Leslie; Jiang, Xiaohua; Glowacki, Bartek; Zeng, Rong; Minervini, Joseph; Brisson, John

    2014-01-01

    The Massachusetts Institute of Technology, the University of Cambridge in the United Kingdom, and Tsinghua University in Beijing, China, are collaborating to design, construct, and test a 20 m, direct current, superconducting MgB2 and YBCO power cable. The cable will be installed in the State Key Laboratory of Power Systems at Tsinghua University in Beijing beginning in 2013. In a previous paper [1], the cryogenic system was briefly discussed, focusing on the cryogenic issues for the superconducting cable. The current paper provides a detailed discussion of the design, construction, and assembly of the cryogenic system and its components. The two-stage system operates at nominally 80 K and 20 K with the primary cryogen being helium gas. The secondary cryogen, liquid nitrogen, is used to cool the warm stage of binary current leads. The helium gas provides cooling to both warm and cold stages of the rigid cryostat housing the MgB2 and YBCO conductors, as well as the terminations of the superconductors at the end of the current leads. A single cryofan drives the helium gas in both stages, which are thermally isolated with a high effectiveness recuperator. Refrigeration for the helium circuit is provided by a Sumitomo RDK415 cryocooler. This paper focuses on the design, construction, and assembly of the cryostat, the recuperator, and the current leads with associated superconducting cable terminations.

  5. Effect of magnetic and nonmagnetic nano metal oxides doping on the critical temperature of a YBCO superconductor

    NASA Astrophysics Data System (ADS)

    Salama, A. H.; El-Hofy, M.; Rammah, Y. S.; Elkhatib, M.

    2015-12-01

    Bulk superconductor samples of YBa2Cu3O7-δ (YBCO) doped with nano metal oxides of Mn3O4, Co3O4, Cr2O3, CuO and SnO2 respectively with 0.2 wt% are synthesized by a solid-state reaction route. The structural characterization of all samples has been carried out by x-ray diffraction (XRD) and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The XRD patterns indicate that the magnetic doping of nano metal oxides ≤ft({{{Mn}}}{{3}}{{{O}}}{{4}}, {{{Co}}}{{3}}{{{O}}}{{4}}, {{{Cr}}}{{2}}{{{O}}}{{3}}\\right) gives a high value of orthorhombicity of the YBCO samples which is the result of high oxygen content, and consequently could give better superconducting properties contrary to the non magnetic nano oxides (CuO, SnO2). The critical temperature (Tc) of the studied samples was found to improve by nano magnetic doping and lower with nano nonmagnetic doping. The superconducting transition temperature Tc determined from electrical resistivity measurements was found to increase for Mn3O4 (5.27 μB) doping and decrease for other metal oxides doping.

  6. Grid Interconnection and Performance Testing Procedures for Vehicle-To-Grid (V2G) Power Electronics: Preprint

    SciTech Connect

    Kramer, W.; Chakraborty, S.; Kroposki, B.; Hoke, A.; Martin, G.; Markel, T.

    2012-03-01

    Bidirectional power electronics can add vehicle-to-grid (V2G) capability in a plug-in vehicle, which then allows the vehicle to operate as a distributed resource (DR). The uniqueness of the battery-based V2G power electronics requires a test procedure that will not only maintain IEEE interconnection standards, but can also evaluate the electrical performance of the vehicle working as a DR. The objective of this paper is to discuss a recently published NREL technical report that provides interim test procedures for V2G vehicles for their integration into the electrical distribution systems and for their performance in terms of continuous output power, efficiency, and losses. Additionally, some other test procedures are discussed that are applicable to a V2G vehicle that desires to provide power reserve functions. A few sample test results are provided based on testing of prototype V2G vehicles at NREL.

  7. Nanostructured Coatings

    NASA Astrophysics Data System (ADS)

    Rivière, J.-P.

    In many branches of technology where surfaces are playing a growing role, the use of coatings is often the only way to provide surfaces with specific functional properties. For example, the austenitic stainless steels or titanium alloys exhibit poor resistance to wear and low hardness values, which limits the field of applications. The idea then is to develop new solutions which would improve the mechanical performance and durability of objects used in contact and subjected to mechanical forces in hostile gaseous or liquid environments. Hard coatings are generally much sought after to enhance the resistance to wear and corrosion. They are of particular importance because they constitute a class of protective coatings which is already widely used on an industrial scale to improve the hardness and lifetime of cutting tools.

  8. Protective Coatings

    NASA Technical Reports Server (NTRS)

    1980-01-01

    General Magnaplate Corporation's pharmaceutical machine is used in the industry for high speed pressing of pills and capsules. Machine is automatic system for molding glycerine suppositories. These machines are typical of many types of drug production and packaging equipment whose metal parts are treated with space spinoff coatings that promote general machine efficiency and contribute to compliance with stringent federal sanitation codes for pharmaceutical manufacture. Collectively known as "synergistic" coatings, these dry lubricants are bonded to a variety of metals to form an extremely hard slippery surface with long lasting self lubrication. The coatings offer multiple advantages; they cannot chip, peel or be rubbed off. They protect machine parts from corrosion and wear longer, lowering maintenance cost and reduce undesired heat caused by power-robbing friction.

  9. Preparation and microstructures of high-current density YBCO films by no-water post-annealing of precursor films including BaF 2

    NASA Astrophysics Data System (ADS)

    Ichinose, Ataru; Kikuchi, Akihiro; Kiss, Takanobu; Tachikawa, Kyoji; Akita, Shirabe; Inoue, Kiyoshi

    2003-10-01

    Precursor films are deposited on SrTiO 3 single crystals at room temperature by the co-evaporation technique using Y, BaF 2 and Cu as evaporation sources. Then, the precursor films are annealed in a low-pressure oxygen atmosphere without introduction of water vapor. A sample with a reflection high-energy electron diffraction (RHEED) pattern exhibiting some streaks, Kikuchi lines and Kikuchi zone, which resembles that of a single crystal, is successfully prepared. According to the cross-sectional TEM observation results, epitaxial growth of this YBCO film is achieved for the entire film thickness. The transport properties are measured using a small bridge with a width of 0.1 mm and a length of 1 mm by a standard four-probe method. The obtained YBCO film has a high Jc of over 1 MA/cm 2 at 77 K and a self-field. Furthermore, we discuss the relationship between the epitaxial YBCO layer thickness and the annealing conditions. Approximately 300- and 400-nm-thick epitaxial YBCO films are successfully prepared.

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

    DOEpatents

    Mueller, Fred M.; Haenisch, Jens

    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.

  11. Gold Coating

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Epner Technology Inc. responded to a need from Goddard Space Flight Center for the ultimate in electroplated reflectivity needed for the Mars Global Surveyor Mars Orbiter Laser Altimeter (MOLA). Made of beryllium, the MOLA mirror was coated by Epner Technology Laser Gold process, specially improved for the project. Improved Laser Gold- coated reflectors have found use in an epitaxial reactor built for a large semiconductor manufacturer as well as the waveguide in Braun-Thermoscan tympanic thermometer and lasing cavities in various surgical instruments.

  12. Water molecules inside protein structure affect binding of monosaccharides with HIV-1 antibody 2G12.

    PubMed

    Ueno-Noto, Kaori; Takano, Keiko

    2016-10-01

    Water molecules inside biomolecules constitute integral parts of their structure and participate in the functions of the proteins. Some of the X-ray crystallographic data are insufficient for analyzing a series of ligand-protein complexes in the same condition. We theoretically investigated antibody binding abilities of saccharide ligands and the effects of the inner water molecules of ligand-antibody complexes. Classical molecular dynamics and quantum chemical simulations using a model with possible water molecules inside the protein were performed with saccharide ligands and Human Immunodeficiency Virus 1 neutralizing antibody 2G12 complexes to estimate how inner water molecules of the protein affect the dynamics of the complexes as well as the ligand-antibody interaction. Our results indicate the fact that d-fructose's strong affinity to the antibody was partly due to the good retentiveness of solvent water molecules of the ligand and its stability of the ligand's conformation and relative position in the active site. © 2016 Wiley Periodicals, Inc.

  13. Exotic insulating states of (t2 g) 4 Hubbard model with spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Sato, Toshihiro; Shirakawa, Tomonori; Yunoki, Seiji

    We numerically study electronic properties of a t2 g-orbital Hubbard model with a relativistic spin-orbit coupling (SOC) at four electrons per site. Our approach is a multi-orbital dynamical mean field theory with a continuous-time quantum Monte Carlo solver based on a strong coupling expansion. The main issue is the variation of electronic structure in the parameter space of the SOC and the Coulomb interactions at temperature fixed. For larger Coulomb interactions, a Van Vleck-type nonmagnetic insulating state with a total angular momentum J = 0 is induced by the SOC. When the SOC decreases, the insulating state is magnetically ordered along with increasing the hybridization between a nonmagnetic J = 0 state and an excited J = 1 state. Moreover, for smaller Coulomb interactions, we demonstrate that an excitonic insulating state without magnetic order appears, in addition to metallic and band insulating states. The exciton condensation is formed by an electron-hole pairing between the local effective total angular momentum j = 1 / 2 and j = 3 / 2 based bands.

  14. Affleck-Kennedy-Lieb-Tasaki State on a Honeycomb Lattice from t(2g) Orbitals.

    PubMed

    Koch-Janusz, Maciej; Khomskii, D I; Sela, Eran

    2015-06-19

    The two-dimensional Affleck-Kennedy-Lieb-Tasaki (AKLT) model on a honeycomb lattice has been shown to be a universal resource for quantum computation. In this valence bond solid, however, the spin interactions involve higher powers of the Heisenberg coupling (S[over →](I)·S[over →](j))(n), making these states seemingly unrealistic on bipartite lattices, where one expects a simple antiferromagnetic order. We show that those interactions can be generated by orbital physics in multiorbital Mott insulators. We focus on t(2g) electrons on the honeycomb lattice and propose a physical realization of the spin-3/2 AKLT state. We find a phase transition from the AKLT to the Néel state on increasing Hund's rule coupling, which is confirmed by density matrix renormalization group simulations. An experimental signature of the AKLT state consists of protected, free S=1/2 spins on lattice vacancies, which may be detected in the spin susceptibility. PMID:26197004

  15. Water molecules inside protein structure affect binding of monosaccharides with HIV-1 antibody 2G12.

    PubMed

    Ueno-Noto, Kaori; Takano, Keiko

    2016-10-01

    Water molecules inside biomolecules constitute integral parts of their structure and participate in the functions of the proteins. Some of the X-ray crystallographic data are insufficient for analyzing a series of ligand-protein complexes in the same condition. We theoretically investigated antibody binding abilities of saccharide ligands and the effects of the inner water molecules of ligand-antibody complexes. Classical molecular dynamics and quantum chemical simulations using a model with possible water molecules inside the protein were performed with saccharide ligands and Human Immunodeficiency Virus 1 neutralizing antibody 2G12 complexes to estimate how inner water molecules of the protein affect the dynamics of the complexes as well as the ligand-antibody interaction. Our results indicate the fact that d-fructose's strong affinity to the antibody was partly due to the good retentiveness of solvent water molecules of the ligand and its stability of the ligand's conformation and relative position in the active site. © 2016 Wiley Periodicals, Inc. PMID:27388036

  16. Phenotype in parkinsonian and nonparkinsonian LRRK2 G2019S mutation carriers

    PubMed Central

    Schuele, B.; Munhoz, R.P.; Rogaeva, E.; Langston, J.W.; Kasten, M.; Meaney, C.; Klein, C.; Wadia, P.M.; Lim, S.-Y.; Chuang, R.S.-I.; Zadikof, C.; Steeves, T.; Prakash, K.M.; de Bie, R.M.A.; Adeli, G.; Thomsen, T.; Johansen, K.K.; Teive, H.A.; Asante, A.; Reginold, W.; Lang, A.E.

    2011-01-01

    Objectives: Using a family study design, we describe the motor and nonmotor phenotype in probands with LRRK2 G2019S mutations and family members and compare these individuals to patients with idiopathic Parkinson disease (iPD) and unrelated controls. Methods: Probands with G2019S mutations and their first-degree relatives, subjects with iPD, and unrelated control subjects were identified from 4 movement disorders centers. All underwent neurologic examinations and tests of olfaction, color vision, anxiety, and depression inventories. Results: Tremor was more often a presenting feature among 25 individuals with LRRK2-associated PD than among 84 individuals with iPD. Subjects with LRRK2-PD had better olfactory identification compared with subjects with iPD, higher Beck Depression Inventory scores, and higher error scores on Farnsworth-Munsell 100-Hue test of color discrimination. Postural or action tremor was more common among 29 nonmanifesting mutation carriers compared with 53 noncarriers within the families. Nonparkinsonian family members had higher Unified Parkinson's Disease Rating Scale motor scores, more constipation, and worse color discrimination than controls, regardless of mutation status. Conclusions: Although tremor is a more common presenting feature of LRRK2-PD than iPD and some nonmotor features differed in degree, the phenotype is largely overlapping. Postural or action tremor may represent an early sign. Longitudinal evaluation of a large sample of nonmanifesting carriers will be required to describe any premotor phenotype that may allow early diagnosis. PMID:21753163

  17. Comparison of six denuder methods and a filter pack for the collection of ambient HNO 3(g), HNO 2(g) and SO 2(g) in the 1985 NSMC study

    NASA Astrophysics Data System (ADS)

    Eatough, Norman L.; McGregor, Scott; Lewis, Edwin A.; Eatough, Delbert J.; Huang, Andrew A.; Ellis, Elizabeth C.

    The concentrations of HNO 2(g), HNO 2(g), particle nitrate and particle nitrite have been determined using annular denuders (AD), nylon denuders (ND), short nylon denuders (SD), tungstic acid denuders (TD), cylindrical carbonate denuders (CD), a filter pack (FP), and a denuder difference method (DD) in field tests during the 1985 NSMCS. Concentrations of SO 2(g) and particle sulfate were measured by the annular denuder (AD) and cylindrical carbonate denuder (CD) systems. The results of linear regression comparison of various collection methods for total nitrate, HNO 3(g) and HNO 2(g), and results calculated as the denuder difference between nitrate and nitrite collected on the FP sampler and on the filter pack after the AD are presented. Results for HNO 3(g) and particle nitrate measured by the different sampling systems compared well with the exception of the TD and CD systems. The AD, FP and SD samplers showed the best consistency in results presumably because they operate at higher flow rates and give more sample with correspondingly lower analytical errors. The results obtained for the nitrogenous species studied are also correlated with other atmospheric parameters which might be related to the formation of HNO 3(g) and/or HNO 2(g) in the atmosphere. Concentrations of SO 2(g) measured by the annular denuder (AD) are compared to values determined by flame photometry.

  18. A new RE + 011 TSIG method for the fabrication of high quality and large size single domain YBCO bulk superconductors

    NASA Astrophysics Data System (ADS)

    Yang, W. M.; Chen, L. P.; Wang, X. J.

    2016-02-01

    High quality single domain YBCO bulk superconductors, 20 mm in diameter, have been fabricated using a new top seeded infiltration and growth method (called the RE + 011 TSIG method), with a new solid phase (Y2O3 + xBaCuO2) instead of the conventional Y2BaCuO5 solid phase, x = 0, 0.5, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 3.0. The effects of different BaCuO2 contents x on the growth morphology, microstructure, and levitation force have been investigated. The results show that the levitation force of the YBCO bulks first increases and then decreases with increasing x, and reaches maximum levitation forces of about 49.2 N (77 K, 0.5 T, with the traditional liquid phase of YBa2Cu3O y + 3 BaCuO2 + 2 CuO) and 47 N (77.3 K, 0.5 T, with the new liquid phase of Y2O3 + 10 BaCuO2 + 6 CuO) when x = 1.2, which is much higher than that of the samples fabricated with the conventional solid phases (23 N). The average Y2BaCuO5 particle size is about 1 μm, which is much smaller than the 3.4 μm in the samples prepared with the conventional Y2BaCuO5 solid phase; this means that the flux pinning force of the sample can be improved by using the new solid phase. Based on this method, single domain YBCO bulks 40 mm, 59 mm, and 93 mm in diameter have also been fabricated using the TSIG process with the new solid phases (Y2O3 + 1.2BaCuO2). These results indicate that the new TSIG process developed by our lab is a very important and practical method for the fabrication of low cost, large size, and high quality single domain REBCO bulk superconductors.

  19. Dimeric Ube2g2 simultaneously engages donor and acceptor ubiquitins to form Lys48-linked ubiquitin chains

    PubMed Central

    Liu, Weixiao; Shang, Yongliang; Zeng, Yan; Liu, Chao; Li, Yanchang; Zhai, Linhui; Wang, Pan; Lou, Jizhong; Xu, Ping; Ye, Yihong; Li, Wei

    2014-01-01

    Cellular adaptation to proteotoxic stress at the endoplasmic reticulum (ER) depends on Lys48-linked polyubiquitination by ER-associated ubiquitin ligases (E3s) and subsequent elimination of ubiquitinated retrotranslocation products by the proteasome. The ER-associated E3 gp78 ubiquitinates misfolded proteins by transferring preformed Lys48-linked ubiquitin chains from the cognate E2 Ube2g2 to substrates. Here we demonstrate that Ube2g2 synthesizes linkage specific ubiquitin chains by forming an unprecedented homodimer: The dimerization of Ube2g2, mediated primarily by electrostatic interactions between two Ube2g2s, is also facilitated by the charged ubiquitin molecules. Mutagenesis studies show that Ube2g2 dimerization is required for ER-associated degradation (ERAD). In addition to E2 dimerization, we show that a highly conserved arginine residue in the donor Ube2g2 senses the presence of an aspartate in the acceptor ubiquitin to position only Lys48 of ubiquitin in proximity to the donor E2 active site. These results reveal an unanticipated mode of E2 self-association that allows the E2 to effectively engage two ubiquitins to specifically synthesize Lys48-linked ubiquitin chains. PMID:24366945

  20. BRN 3.1 Knockouts Affect the Vestibular, Autonomic, and Circadian Rhythm Responses to 2G Exposure

    NASA Technical Reports Server (NTRS)

    Murakami, D. M.; Erkman, L.; Rosenfeld, M. G.; Fuller, C. A.

    1999-01-01

    Our previous studies have demonstrated that 2G exposure via centrifugation significantly attenuated the daily mean and circadian rhythm amplitude of rat body temperature (Tb), heart rate, and activity (Act). In addition, 2G exposure activates neural responses in several vestibular, autonomic, and circadian nuclei. Although we have characterized the effect of 2G on an animal's physiological, neuronal, and behavioral responses, it will be important to understand the underlying neural and physiological mechanisms that mediate those responses. For example, the vestibular responses, proprioceptive feedback, or fluid shifts may be the critical factors that mediate the responses to 2G. As a first step to understand the relative importance of these different response pathways to altered gravitational fields, this study examined the contribution of the vestibular system by utilizing an animal model from molecular biology. Brain 3.1 (Bm 3.1) is a POU domain homeobox gene involved in the normal development of the vestibular and auditory system. Brn 3.1 deletion results in a loss of hair cells in the otoliths, semicircular canals, and cochlea. As a result mice with a Brn 3.1 deletion do not have a functioning vestibular or auditory system. The BRN 3.1 knockout mouse could be a very useful animal model for isolating the role of the vestibular system in mediating the physiological responses to 2G exposure. Therefore, this study compared the effect of 2G exposure via centrifugation between Brn 3.1 knockout (KO) versus Wildtype (W) mice.

  1. The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Myers, Dwight L.

    2011-01-01

    The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.

  2. COATING METHOD

    DOEpatents

    Townsend, R.G.

    1959-08-25

    A method is described for protectively coating beryllium metal by etching the metal in an acid bath, immersing the etched beryllium in a solution of sodium zincate for a brief period of time, immersing the beryllium in concentrated nitric acid, immersing the beryhlium in a second solution of sodium zincate, electroplating a thin layer of copper over the beryllium, and finally electroplating a layer of chromium over the copper layer.

  3. Quantitative magneto-optical analysis of the role of finite temperatures on the critical state in YBCO thin films

    NASA Astrophysics Data System (ADS)

    Albrecht, Joachim; Brück, Sebastian; Stahl, Claudia; Ruoß, Stephen

    2016-11-01

    We use quantitative magneto-optical microscopy to investigate the influence of finite temperatures on the critical state of thin YBCO films. In particular, temperature and time dependence of supercurrents in inhomogeneous and anisotropic films are analyzed to extract the role of temperature on the supercurrents themselves and the influence of thermally activated relaxation. We find that inhomogeneities and anisotropies of the current density distribution correspond to a different temperature dependence of local supercurrents. In addition, the thermally activated decay of supercurrents can be used to extract local vortex pinning energies. With these results the modification of vortex pinning introduced by substrate structures is studied. In summary the local investigation of supercurrent densities allows the full description of the vortex pinning landscape with respect to pinning forces and energies in superconducting films with complex properties under the influence of finite temperatures.

  4. Dependence of levitation force on frequency of an oscillating magnetic levitation field in a bulk YBCO superconductor

    NASA Astrophysics Data System (ADS)

    Carter, Hamilton; Pate, Stephen; Goedecke, George

    2013-02-01

    The dependence of the magnetic field strength required for levitation of a melt textured, single domain YBCO superconductor disk on the frequency of the current generating the levitating magnetic field has been investigated. The magnetic field strength is found to be independent of frequency between 10 and 300 Hz. This required field strength is found to be in good experimental and theoretical agreement with the field strength required to levitate the same superconductor with a non-oscillating magnetic field. Hysteretic losses within the superconductor predicted by Bean’s critical-state model were also calculated. The measured data rules out any significant Bean’s model effects on the required levitation field strength within the measured frequency range.

  5. Power grid operation risk management: V2G deployment for sustainable development

    NASA Astrophysics Data System (ADS)

    Haddadian, Ghazale J.

    The production, transmission, and delivery of cost--efficient energy to supply ever-increasing peak loads along with a quest for developing a low-carbon economy require significant evolutions in the power grid operations. Lower prices of vast natural gas resources in the United States, Fukushima nuclear disaster, higher and more intense energy consumptions in China and India, issues related to energy security, and recent Middle East conflicts, have urged decisions makers throughout the world to look into other means of generating electricity locally. As the world look to combat climate changes, a shift from carbon-based fuels to non-carbon based fuels is inevitable. However, the variability of distributed generation assets in the electricity grid has introduced major reliability challenges for power grid operators. While spearheading sustainable and reliable power grid operations, this dissertation develops a multi-stakeholder approach to power grid operation design; aiming to address economic, security, and environmental challenges of the constrained electricity generation. It investigates the role of Electric Vehicle (EV) fleets integration, as distributed and mobile storage assets to support high penetrations of renewable energy sources, in the power grid. The vehicle-to-grid (V2G) concept is considered to demonstrate the bidirectional role of EV fleets both as a provider and consumer of energy in securing a sustainable power grid operation. The proposed optimization modeling is the application of Mixed-Integer Linear Programing (MILP) to large-scale systems to solve the hourly security-constrained unit commitment (SCUC) -- an optimal scheduling concept in the economic operation of electric power systems. The Monte Carlo scenario-based approach is utilized to evaluate different scenarios concerning the uncertainties in the operation of power grid system. Further, in order to expedite the real-time solution of the proposed approach for large-scale power systems

  6. The growth of the complex oxide YBCO by pulsed organo-metallic beam epitaxy

    NASA Astrophysics Data System (ADS)

    Buchholz, Donald Bruce

    To address the problems associated with the thin film heteroepitaxial growth of complex oxides a deposition technique, called pulsed organo-metallic beam epitaxy (POMBE), is developed. POMBE is designed to grow films layer-by-layer. Organo-metallics are delivered to the substrate as a series of discrete pulses via a set of computer-controlled valves. The precursor sequence and the amount of precursor in each pulse is programmed as the computer. Quartz crystal microbalances monitor the precursor transport rates. Computer feedback control maintains the precursor pulses at their programmed values. The ability to grow films layer-by-layer and to control the amount of material in each layer is demonstrated by the growth of YBasb2CUsb3Osb{7-delta}/PrBasb2CUsb3Osb{7-delta} superlattices. This is the first report of a high temperature superconductor superlattice grown by a chemical vapor deposition technique. The ability to grow films layer-by-layer is used to investigate the effect of changing the type and amount of precursor used to start the film growth. The correct choice of these parameters allows the growth of (001) YBasb2Cusb3Osb{7-delta} with a single in-plane orientation and Jsb{c}(77 K,0T) = 1-2× 10sp6amp/cmsp2 on (100) LaAlOsb3, (100) NdGaOsb3, (100) MgO, and (100) YSZ. The ability to control the initial film layer provides a means to control the in-plane orientation of (001) YBasb2Cusb3Osb{7-delta} (YBCO) grown on (100) MgO. Depositions started with thin BaO layers ({}{≈}1.1× 10sp{15}Ba/cmsp2) grow lbrack 100rbrack YBCOVertlbrack 100rbrack MgO. A mechanism that relates the change of in-plane orientation to a structural change of the initial BaO layer is described. The in-plane orientation of (001) YBasb2Cusb3Osb{7-delta} grown on (100) MgO can also be controlled by the ex situ, low energy Arsp+ sputtering of the MgO surface prior to film growth. To simultaneously grow lbrack 110rbrack YBCOVertlbrack 100rbrack MgO on non-sputtered MgO and lbrack 100rbrack

  7. Effects of ambient background gases on YBCO plume propagation under film growth conditions: Spectroscopic, ion probe, and fast photographic studies

    SciTech Connect

    Geohegan, D.B.

    1991-09-01

    The formation, composition, and propagation of KrF laser-produced plasmas from Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x} have been studied with emphasis on topics relevant to film growth by pulsed-laser deposition. Spatially and temporally resolved, high-resolution optical absorption and emission spectroscopy, fast ion probes, and fast photography (obtained with a gated, image-intensified CCD array detector (ICCD)) are employed to investigate both emitting and non-emitting species in the laser plume as well as the overall shape and propagation of the laser plasma in background gases of oxygen and xenon. Transient optical absorption spectroscopy is applied to study the composition of the plume of ejected material from the dense layer near the target surface to distances of several centimeters. Optical absorption persists long after the decay of plasma fluorescence, indicating a slower component to plume transport. The absorption of YO formed by YBCO ablation in vacuum and by-yttrium ablation in oxygen is presented. Fast electric ion probes are utilized to measure velocities and total collected charge of the positive ions in the expanding YBCO laser plasma from near-threshold, vacuum conditions into the high fluence, background gas conditions utilized for thin-film growth. The exponential attenuation of the positive ion flux transmitted through 50--300 mTorr background oxygen is measured and used to define an attenuation coefficient. The showing of the laser plasma and formation of shock structures due to gas collisions is studied by ion probe measurements and fast ICCD photography. A comparison between shock wave propagation and drag models is presented to describe the arrival time and shape of the ion probe current waveform with distance. 11 refs, 11 figs.

  8. The magnetisation profiles and ac magnetisation losses in a single layer YBCO thin film caused by travelling magnetic field waves

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Coombs, Timothy

    2015-05-01

    This paper studies the magnetisation and ac magnetisation losses caused by a travelling magnetic wave on a single-layer YBCO thin film. This work provides thorough investigations on how the critical magnetic field gradient has been changed by the application of a travelling wave. Several conditions were studied such as zero-field cooling (ZFC), field cooling (FC) and a delta-shaped trapped field. It was found that the travelling wave tends to attenuate the existing critical magnetic field gradients in all these conditions. This interesting magnetic behaviour can be well predicted by the finite element (FEM) software with the E-J power law and Maxwell’s equations. The numerical simulations show that the existing critical current density has been compromised after applying the travelling wave. The magnetisation profile caused by the travelling wave is very different from the standing wave, while the magnetisation based on the standing wave can be interpreted by the Bean model and constant current density assumption. Based on the numerical method, which has reliability that has been solidly proven in the study, we have extended the study to the ac magnetisation losses. Comparisons were made between the travelling wave and the standing wave for this specific YBCO sample. It was found that by applying the magnetic wave of the same amplitude, the ac magnetisation loss caused by the travelling wave is about 1/3 of that caused by the standing wave. These results are helpful in understanding the general magnetism problems and ac magnetisation loss in the travelling magnetic wave conditions such as inside a high temperature superconducting (HTS) rotating machine, etc.

  9. Simulation and experiment of a YBCO SMES prototype in voltage sag compensation

    NASA Astrophysics Data System (ADS)

    Zhu, Jiahui; Yuan, Weijia; Coombs, T. A.; Ming, Q.

    2011-03-01

    This paper gives a introduction of a SMES unit using 2G HTS wires. A complete SMES system including both superconducting coils and control circuit has been designed to operate at 77 K. Three single-phase H-bridge converters have been used in the control circuit. A loop control signal is sent out by using 32 fixed point Digital Signal Processor (DSP). The complete circuit has been both modelled in simulation and built experimentally. The results validate that this SMES successfully compensates a voltage sag in a power system.

  10. Magnetic and structural characterization of inkjet-printed TFAYBa2Cu3O7-x/MODCZO/ABADYSZ/SS coated conductors

    NASA Astrophysics Data System (ADS)

    Bartolomé, E.; Vlad, V. R.; Calleja, A.; Aklalouch, M.; Guzmán, R.; Arbiol, J.; Granados, X.; Palau, A.; Obradors, X.; Puig, T.; Usoskin, A.

    2013-12-01

    The superconductor industry is demanding new methodologies to manufacture km-long, high quality coated conductors at high growth rates, using cost-effective, scalable processes. We report on the fabrication by an all-chemical deposition method of highly textured, thick (0.9 μm) inkjet-printed YBCO films, using a Ce0.9Zr0.1O2 (CZO) capping layer deposited by MOD, on top of robust, buffered ABADYSZ/SS substrates. Thinner, 0.25 μm spin-coated YBCO films were also analyzed for comparison. The structural study performed by x-ray diffraction, optical, AFM, SEM and TEM microscopy demonstrates the success of the capping layer for enhancing the planarity of the as-received tape and obtaining highly homogeneous and well-textured YBCO films. DC magnetometry granularity analysis was used to determine the mean superconducting grain diameter, ˜2.5 μm, and the intra- and intergranular critical current densities of the coated conductors (CCs). For the thin, spin-coated sample, high self-field intragrain critical currents were measured ({J}_{{c}}^{{G}}=4 0, 3.3 MA cm-2 at 5, 77 K). For the thick, inkjet-printed tape {J}_{{c}}^{{G}} was reduced by ˜30%, but, notably, the percolative critical current, {J}_{{c}}^{{GB}}=1 2.5~{MA}~{{cm}}^{-2}, was only ˜10% smaller at 5 K, thanks to good preservation of the texture. At 77 K, {J}_{{c}}^{{GB}}=1.3~{MA}~{{cm}}^{-2} was achieved, implying a critical current of Ic = 117 A/cm-width. AC susceptibility measurements allowed us to demonstrate the high homogeneity of the fabricated CCs, and investigate the magnetic vortex-pinning phase diagram. Remarkably, the thick, inkjet-printed sample showed comparable irreversibility line (IL) and activation energy for thermal depinning, Ue(H), to the thin sample. The present results open new perspectives for the fabrication of high quality-to-cost ratio, all-chemical CCs with yet higher Ic values by inkjet printing multideposition of thicker YBCO layers.

  11. Dual Ion Assist Beam Deposition of Magnesium Oxide for Coated Conductors

    NASA Astrophysics Data System (ADS)

    Groves, J. R.; Arendt3, P. N.; Holesinger, T. G.; Hammond, R. H.; Foltyn, S. R.; DePaula, R. F.; Stan, L.; Usov, I. O.

    2006-03-01

    Ion Beam Assisted Deposition (IBAD) of Magnesium Oxide (MgO) has been proven to be a viable route for producing template films used to deposit high quality YBCO coated conductors on flexible polycrystalline metal substrates. Here we will discuss improvements in this process using a dual ion assist beam configuration. Dual ion assist beam deposition of MgO reduces the requirements for substrate surface finishing while maintaining comparable film quality (phi scan full-width at half-maximum values between 7 and 8 degrees). Furthermore, this adaptation of the IBAD process eliminates the degradation of MgO texture observed in thick IBAD MgO films deposited on silicon nitride. We have deposited films up to 50 nanometers thick without degradation of in-plane texture. Increasing the MgO thickness increases the chemical stability of the template layer and can eliminate the necessity for subsequent buffer layers or the application of the homoepitaxial MgO layer needed to stabilize the thin, conventional IBAD MgO layer. Initial results of subsequently deposited YBCO on these dual assist ion beam MgO templates are quite promising.

  12. Solution Deposition Approaches To Coated Conductor Fabrication on Biaxially Textured Ni-W Alloy Substrates

    SciTech Connect

    Sathyamurthy, S.

    2001-06-20

    Sol-gel processing of La{sub 2}Zr{sub 2}O{sub 7} (LZO) was used to process buffer layers on biaxially textured Ni-3 at.%W substrates. A reel-to-reel continuous dip-coating unit was used to deposit the solution buffers. Epitaxial LZO films have been obtained through continuous processing on Ni-3 at.%W substrates with strong texture and uniform microstructure. The carbon content in these films were analyzed using proton resonance Rutherford Backscattering (RBS). The process parameters have been modified so as to study the effect of the carbon content in these films towards further growth of YBCO films with better properties. The LZO buffers were used as seed layers for RABiTS with the architecture of CeO{sub 2}/YSZ/LZO/Ni-3 at.%W, and YBCO films with critical current density (J{sub c}) of 1.9 MA/cm{sup 2} at 77K in self-field, and a J{sub c} of 0.34 MA/cm{sup 2} at 0.5 T, have been obtained.

  13. Thermal radiative properties: Coatings.

    NASA Technical Reports Server (NTRS)

    Touloukian, Y. S.; Dewitt, D. P.; Hernicz, R. S.

    1972-01-01

    This volume consists, for the most part, of a presentation of numerical data compiled over the years in a most comprehensive manner on coatings for all applications, in particular, thermal control. After a moderately detailed discussion of the theoretical nature of the thermal radiative properties of coatings, together with an overview of predictive procedures and recognized experimental techniques, extensive numerical data on the thermal radiative properties of pigmented, contact, and conversion coatings are presented. These data cover metallic and nonmetallic pigmented coatings, enamels, metallic and nonmetallic contact coatings, antireflection coatings, resin coatings, metallic black coatings, and anodized and oxidized conversion coatings.

  14. A simple MOD method to grow a single buffer layer of Ce 0.8Gd 0.2O 1.9 (CGO) for coated conductors

    NASA Astrophysics Data System (ADS)

    Liu, Min; Shi, Dongqi; Suo, Hongli; Ye, Shuai; Zhao, Yue; Zhu, Yonghua; Li, Qi; Wang, Lin; Jihyun, Ahn; Zhou, Meiling

    2009-03-01

    A single Ce 0.8Gd 0.2O 1.9 (CGO) buffer layer was successfully grown on the home-made textured Ni-5 at.%W (Ni-5W) substrates for YBCO coated conductors by a simple metal-organic deposition (MOD) technique. The precursor solution was prepared using a newly developed process and only contained common metal-organic salts of both Ce and Gd dissolved into a propionic acid solvent. The precursor solution at 0.4 M concentration was spin coated on short samples of Ni-5W substrates and heat-treated at 1100 °C in a mixture gas of 5% H 2 in Ar for an hour. X-ray studies indicated that the CGO films had good out-of-plane and in-plane textures with full-width-half-maximum values of 4.18° and 6.19°, respectively. Atomic force microscope (AFM) investigations of the CGO films revealed that most of the grain boundary grooves on the Ni-5W surface were found to be well covered by CGO layers, which had a fairly dense and smooth microstructure without cracks and porosity. These results indicate that our MOD technique is very promising for further development of single buffer layer architecture for YBCO coated conductors, due to its low cost and simple process.

  15. Singularity-conquering ZG controllers of z2g1 type for tracking control of the IPC system

    NASA Astrophysics Data System (ADS)

    Zhang, Yunong; Yu, Xiaotian; Yin, Yonghua; Peng, Chen; Fan, Zhengping

    2014-09-01

    With wider investigations and applications of autonomous robotics and intelligent vehicles, the inverted pendulum on a cart (IPC) system has become more attractive for numerous researchers due to its concise and representative structure. In this article, the tracking-control problem of the IPC system is considered and investigated. Based on Zhang dynamics (ZD) and gradient dynamics (GD), a novel kind of ZG controllers are developed and investigated for achieving the tracking-control purpose, which contains controllers of z2g0 and z2g1 types according to the number of times of using the ZD and GD methods. Besides, theoretical analyses are presented to guarantee the global and exponential convergence performance of both z2g0 and z2g1 controllers. Computer simulations are further performed to substantiate the feasibility and effectiveness of ZG controllers. More importantly, comparative simulation results demonstrate that controllers of z2g1 type can conquer the singularity problem (i.e. the division-by-zero problem).

  16. Grain orientations and distribution of Y2Ba4CuUOx phase in melt-textured YBCO with addition of depleted uranium oxide studied by EBSD

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Mücklich, F.; Koblischka, M. R.; Babu, N. Hari; Cardwell, D. A.; Murakami, M.

    2006-07-01

    The local grain orientations and the distribution of Y2Ba4CuUOx (U-2411) phase are measured within melt-textured YBCO samples by means of electron backscatter diffraction (EBSD). In this work, several samples with varying addition (0.1-0.8 wt%) of depleted uranium oxide (DU) were analysed by means of EBSD. The embedded U-2411 particles were found to have sizes around 200 nm, some large particles being present in the samples with a high DU concentration. Combined EBSD and EDX analysis enabled the identification of the Kikuchi patterns of the U-2411 phase, so that a true three-phase EBSD scan (YBCO, Y2BaCuO5 and U-2411) becomes possible.

  17. Nesprin-2G, a Component of the Nuclear LINC Complex, Is Subject to Myosin-Dependent Tension.

    PubMed

    Arsenovic, Paul T; Ramachandran, Iswarya; Bathula, Kranthidhar; Zhu, Ruijun; Narang, Jiten D; Noll, Natalie A; Lemmon, Christopher A; Gundersen, Gregg G; Conway, Daniel E

    2016-01-01

    The nucleus of a cell has long been considered to be subject to mechanical force. Despite the observation that mechanical forces affect nuclear geometry and movement, how forces are applied onto the nucleus is not well understood. The nuclear LINC (linker of nucleoskeleton and cytoskeleton) complex has been hypothesized to be the critical structure that mediates the transfer of mechanical forces from the cytoskeleton onto the nucleus. Previously used techniques for studying nuclear forces have been unable to resolve forces across individual proteins, making it difficult to clearly establish if the LINC complex experiences mechanical load. To directly measure forces across the LINC complex, we generated a fluorescence resonance energy transfer-based tension biosensor for nesprin-2G, a key structural protein in the LINC complex, which physically links this complex to the actin cytoskeleton. Using this sensor we show that nesprin-2G is subject to mechanical tension in adherent fibroblasts, with highest levels of force on the apical and equatorial planes of the nucleus. We also show that the forces across nesprin-2G are dependent on actomyosin contractility and cell elongation. Additionally, nesprin-2G tension is reduced in fibroblasts from Hutchinson-Gilford progeria syndrome patients. This report provides the first, to our knowledge, direct evidence that nesprin-2G, and by extension the LINC complex, is subject to mechanical force. We also present evidence that nesprin-2G localization to the nuclear membrane is altered under high-force conditions. Because forces across the LINC complex are altered by a variety of different conditions, mechanical forces across the LINC complex, as well as the nucleus in general, may represent an important mechanism for mediating mechanotransduction.

  18. 3-Formyl-BODIPY Phenylhydrazone as a Chromo-Fluorogenic Probe for Selective Detection of NO2 (g).

    PubMed

    Juárez, L Alberto; Costero, Ana M; Parra, Margarita; Gaviña, Pablo; Gil, Salvador

    2016-06-13

    A new colorimetric and fluorogenic probe, based on a 3-formyl boron dipyrromethene (BODIPY) phenylhydrazone, for the sensitive and selective detection NO2 (g) has been prepared. The probe in solution experiences a remarkable hypsochromic shift of its absorption and fluorescence emission bands in the presence gaseous NO2 (g), leading to limits of detection of few ppb. The probe also works in the solid phase, adsorbed on filter paper strips, or chemically immobilized on the surface of silica nanoparticles, with limits of detection to the naked eye of about 0.5 ppm. PMID:27144840

  19. Search for E(2g) phonon modes in MgB2 single crystals by point-contact spectroscopy.

    PubMed

    Naidyuk, Yu G; Yanson, I K; Kvitnitskaya, O E; Lee, S; Tajima, S

    2003-05-16

    The electron-phonon interaction in magnesium diboride MgB2 single crystals is investigated by point-contact (PC) spectroscopy. For the first time the electron coupling with E(2g) phonon modes is resolved in the PC spectra. The correlation between intensity of the extremely broad E(2g) modes in the PC spectra and value of the superconducting gap is established. Our observations favor current theoretical models for electron-phonon mediated superconductivity in MgB2, and they better match the harmonic phonon model.

  20. 3-Formyl-BODIPY Phenylhydrazone as a Chromo-Fluorogenic Probe for Selective Detection of NO2 (g).

    PubMed

    Juárez, L Alberto; Costero, Ana M; Parra, Margarita; Gaviña, Pablo; Gil, Salvador

    2016-06-13

    A new colorimetric and fluorogenic probe, based on a 3-formyl boron dipyrromethene (BODIPY) phenylhydrazone, for the sensitive and selective detection NO2 (g) has been prepared. The probe in solution experiences a remarkable hypsochromic shift of its absorption and fluorescence emission bands in the presence gaseous NO2 (g), leading to limits of detection of few ppb. The probe also works in the solid phase, adsorbed on filter paper strips, or chemically immobilized on the surface of silica nanoparticles, with limits of detection to the naked eye of about 0.5 ppm.

  1. Concentrations of ticarcillin and clavulanic acid in human bone after prophylactic administration of 5.2 g of timentin.

    PubMed Central

    Adam, D; Heilmann, H D; Weismeier, K

    1987-01-01

    The penetration of ticarcillin and clavulanate into their distribution space within human bone was determined after prophylactic administration of 5.2 g of timentin (5 g of ticarcillin plus 0.2 g of clavulanic acid) to 20 patients undergoing hip surgery. All samples were taken 45 to 85 min postadministration. The mean concentrations of ticarcillin in spongiosa and corticalis bone were 57.1 and 70.5 mg/kg, respectively; those of clavulanic acid were 17.8 and 32.5 mg/kg, respectively. No infections occurred in these patients. PMID:3619427

  2. Polymorphisms in PLA2G6 and PLA2G4C genes for calcium-independent phospholipase A2 do not contribute to attenuated niacin skin flush response in schizophrenia patients.

    PubMed

    Nadalin, S; Radović, I; Buretić-Tomljanović, A

    2015-09-01

    We hypothesized that attenuated niacin skin flushing in schizophrenia patients might be associated with polymorphic variants in PLA2G6 and PLA2G4C genes (rs4375 and rs1549637 variations) which encode calcium-independent phospholipase A2 beta (iPLA2β) and cytosolic phospholipase A2 gamma (cPLA2γ) enzymes. The iPLA2β and cPLA2γ may play an important role in niacin-mediated signaling; in addition to their major role - mediating phospholipids remodeling, which alters membrane receptors and signal transduction, they regulate the reservoir of arachidonic acid for prostaglandins synthesis. Skin response to topical niacin of 0.1M, 0.01M, 0.001M and 0.0001M concentrations in 75 schizophrenia patients was rated using the method of volumetric niacin response (VNR). Neither PLA2G6 nor PLA2G4C gene polymorphisms were significantly associated with VNR values. Furthermore, polymorphisms׳ synergy on niacin skin flushing was also not detected.

  3. Progress in fabrication of large magnetic sheilds by using extended YBCO thick films sprayed on stainless steel with the HVOF technique

    SciTech Connect

    Pavese, F.; Bergadano, E.; Ferri, D.

    1997-06-01

    Fabricating a full box-type magnetic shield, by spraying a thick film of commercial YBCO powder on stainless steel with the oxygen-fuel high-velocity technique (HVOF, also referred to as {open_quotes}continuous detonation spray{close_quotes} (CDS)), requires the solution of several specific problems since the design stage of the project. The design problems of this type of shield are examined and the results obtained in the early stages of the realization are discussed.

  4. NICKEL COATED URANIUM ARTICLE

    DOEpatents

    Gray, A.G.

    1958-10-01

    Nickel coatings on uranium and various methods of obtaining such coatings are described. Specifically disclosed are such nickel or nickel alloy layers as barriers between uranium and aluminum- silicon, chromium, or copper coatings.

  5. Effects on Jc of pinning center morphology for multiple-in-line-damage in coated conductor and bulk, melt-textured HTS

    NASA Astrophysics Data System (ADS)

    Weinstein, R.; Parks, D.; Sawh, R.-P.; Mayes, B.; Gandini, A.; Goyal, A.; Chen, Y.; Selvamanickam, V.

    2009-12-01

    The properties of discontinuous aligned pinning centers (PCs) created by high-energy heavy-ions are compared for bulk melt-textured and coated conductor HTS. Properties of PCs, which increase Jc (pinning potential and entanglement), and negative properties which decrease Jc (e.g., decreased Tc and percolation paths) are evaluated. Mechanisms are proposed to explain the very large increases in Jc resulting from multiple-in-line-damage (MILD) compared to continuous columnar pinning centers (CCPC). In particular, a mechanism which results in fluxoid entanglement, even for parallel (unsplayed) PCs, is discussed. The same mechanism is found to also account for restoration of much of the pinning potential expected to be lost due to the gaps in MILD PCs. It also accounts for the fact that at high fluence, Jc increases as fluence is increased, instead of decreasing as expected. The very low self-field in coated conductor permits separation of the negative and positive effects of PCs. It is found that parameters developed to quantify the negative effects in bulk melt-textured YBCO, by 63 GeV U 238 ions, successfully describe damage to 2.1 μm thick coated conductor by 1 GeV Ru 44 ions. Coated conductor at 77 K and self-field is generally known to have Jc about 100 times that of melt-textured YBCO. However, at 77 K and applied field of 1 T, when both forms of HTS are processed with comparable numbers of near-optimum MILD PCs, the difference in Jc is reduced to a factor of 1.3-2. Whereas Jc for melt-textured YBCO increased sharply, by a factor of up to 16.8 for high-fluence MILD PCs, Jc in coated conductor increased by a smaller factor of 2.5-3.0. Nevertheless, 2.1 μm thick coated conductor, with near-optimum MILD PCs, exhibits Jc = 543 kA/cm 2 at 77 K and applied field of 1.0 T, and Ic = 114 A/cm-width of conductor. This is the highest value we find in the literature. The phenomenology developed indicates that for optimum MILD PCs in coated conductor, Jc ∼ 700 ± 70 k

  6. Corrosion resistant coating

    DOEpatents

    Wrobleski, D.A.; Benicewicz, B.C.; Thompson, K.G.; Bryan, C.J.

    1997-08-19

    A method of protecting a metal substrate from corrosion including coating a metal substrate of, e.g., steel, iron or aluminum, with a conductive polymer layer of, e.g., polyaniline, coating upon said metal substrate, and coating the conductive polymer-coated metal substrate with a layer of a topcoat upon the conductive polymer coating layer, is provided, together with the resultant coated article from said method.

  7. Corrosion resistant coating

    DOEpatents

    Wrobleski, Debra A.; Benicewicz, Brian C.; Thompson, Karen G.; Bryan, Coleman J.

    1997-01-01

    A method of protecting a metal substrate from corrosion including coating a metal substrate of, e.g., steel, iron or aluminum, with a conductive polymer layer of, e.g., polyaniline, coating upon said metal substrate, and coating the conductive polymer-coated metal substrate with a layer of a topcoat upon the conductive polymer coating layer, is provided, together with the resultant coated article from said method.

  8. The Chemistry of Coatings.

    ERIC Educational Resources Information Center

    Griffith, James R.

    1981-01-01

    The properties of natural and synthetic polymeric "coatings" are reviewed, including examples and uses of such coatings as cellulose nitrate lacquers (for automobile paints), polyethylene, and others. (JN)

  9. Enhanced quench propagation in 2G-HTS coils co-wound with stainless steel or anodised aluminium tapes

    NASA Astrophysics Data System (ADS)

    Núñez-Chico, A. B.; Martínez, E.; Angurel, L. A.; Navarro, R.

    2016-08-01

    Early quench detection and thermal stability of superconducting coils are of great relevance for practical applications. Magnets made with second generation high temperature superconducting (2G-HTS) tapes present low quench propagation velocities and therefore slow voltage development and high local temperature rises, which may cause irreversible damage. Since quench propagation depends on the anisotropy of the thermal conductivity, this may be used to achieve an improvement of the thermal stability and robustness of 2G-HTS coils. On pancake type coils, the thermal conductivity along the tapes (coil’s azimuthal direction) is mostly fixed by the 2G-HTS tape characteristics, so that the reduction of anisotropy relies on the improvement of the radial thermal conductivity, which depends on the used materials between superconducting tapes, as well as on the winding and impregnation processes. In this contribution, we have explored two possibilities for such anisotropy reduction: by using anodised aluminium or stainless steel tapes co-wound with the 2G-HTS tapes. For all the analysed coils, critical current distribution, minimum quench energy values and both tangential and radial quench propagation velocities at different temperatures and currents are reported and compared with the results of similar coils co-wound with polyimide (Kapton®) tapes.

  10. Inactivation of pqq Genes of Enterobacter Intermedium 60-2G Reduces Antifungal Activity and Induction of Systemic Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enterobacter intermedium 60-2G, a phosphate solubilizing bacterium, has the ability to induce systemic resistance in plants against soft rot pathogen Erwinia carotovora. Phosphate solubilization is mediated by the production of organic acids. Glucose dehydrogenase, an enzyme which utilizes pyrroloq...

  11. In-situ non-disruptive cleaning of Ge(100) using H2O2(g) and atomic hydrogen

    NASA Astrophysics Data System (ADS)

    Kaufman-Osborn, Tobin; Kiantaj, Kiarash; Chang, Chorng-Ping; Kummel, Andrew C.

    2014-12-01

    In-situ gas phase cleaning of the Ge(100) surface was studied at the atomic level using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) while chemical analysis of the surface was performed using X-ray photoelectron spectroscopy (XPS). High purity H2O2(g) dosing removed carbon contamination from an air exposed Ge(100) sample. The oxide formed via H2O2(g) dosing was subsequently removed via either atomic hydrogen exposure at 300 °C or 550-700 °C annealing. STM imaging showed an air exposed Ge(100) surface after H2O2(g) dosing and 600-700 °C annealing produced a flat and ordered surface while STS verified the density of states (DOS) is equal to that of a Ge(100) surface which has been cleaned via sputter (500 °C) and annealing (700 °C). Combining H2O2(g) with atomic hydrogen dosing or annealing removed carbon via oxidation and oxygen via thermal desorption or reduction from an air exposed Ge(100) surface.

  12. Degradation of Tectilon Yellow 2G by hybrid technique: combination of sonolysis and biodegradation using mutant Pseudomonas putida.

    PubMed

    Srinivasan, Raman; Kathiravan, Mathur Nadarajan; Gopinath, Kannappan Panchamoorthy

    2011-02-01

    Degradation of Tectilon Yellow 2G (TY2G), an azo dye has been studied by hybrid technique involving pretreatment by sonochemical method and further biological treatment by Pseudomonas putida mutant. Pretreatment experiments were carried out by sonolysis of the dye solution at different concentrations (100-1000 mg/L). Wild type Gram-negative P. putida species isolated from the textile effluent contaminated soil, which was found to be effective towards dye degradation, has been acclimatized so as to consume TY2G as the sole source of nutrition. Mutant strain was obtained from the acclimatized species by random mutagenesis using the chemical mutagen ethidium bromide for various time intervals (6-30 min). The optimum mutagenesis exposure time for obtaining the most efficient species for dye degradation was found to be 18 min. An efficient mutant strain P. putida ACT 1 has been isolated and was used for growth experiments. The mutant strain showed a better growth compared to the wild strain. The substrate utilization kinetics has been modeled using Monod and Haldane model equations of which the Haldane model provided a better fit. The enzyme kinetics of the mutant and wild species was obtained using Michaelis-Menten equation. The mutated species showed better enzyme kinetics towards the degradation of TY2G.

  13. 12 CFR 225.139 - Presumption of continued control under section 2(g)(3) of the Bank Holding Company Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... personal or household use to an individual transferee; (ii) student loans made for the education of the... Counsel the authority to issue such determinations, 12 CFR 265.2(b)(1). (b) The purpose of section 2(g)(3... consideration of the effect of such transfers in advance of their being deemed effective. Whether or not...

  14. 12 CFR 225.139 - Presumption of continued control under section 2(g)(3) of the Bank Holding Company Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... personal or household use to an individual transferee; (ii) student loans made for the education of the... Counsel the authority to issue such determinations, 12 CFR 265.2(b)(1). (b) The purpose of section 2(g)(3... consideration of the effect of such transfers in advance of their being deemed effective. Whether or not...

  15. 12 CFR 225.139 - Presumption of continued control under section 2(g)(3) of the Bank Holding Company Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... personal or household use to an individual transferee; (ii) student loans made for the education of the... Counsel the authority to issue such determinations, 12 CFR 265.2(b)(1). (b) The purpose of section 2(g)(3... consideration of the effect of such transfers in advance of their being deemed effective. Whether or not...

  16. Controllable synthesis of CeO2/g-C3N4 composites and their applications in the environment.

    PubMed

    She, Xiaojie; Xu, Hui; Wang, Hefei; Xia, Jiexiang; Song, Yanhua; Yan, Jia; Xu, Yuanguo; Zhang, Qi; Du, Daolin; Li, Huaming

    2015-04-21

    This research has developed a photocatalytic reactor that includes circulating water, light, and a temperature control system. CeO2/g-C3N4 composites with high photocatalytic activity and stability were synthesized by a simple and facile hydrothermal method. The obtained photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It was found that in the CeO2/g-C3N4 composites, the CeO2 nanoparticles were homogeneously cubic in shape (from 3 to 10 nm) and were evenly dispersed on the surface of the g-C3N4. At constant temperature (30 °C), 5% CeO2/g-C3N4 photocatalyst showed the best photocatalytic activity for degrading organic dye methylene blue (MB) under visible light irradiation. The photocatalytic reaction for degrading MB followed first-order kinetics and 5% CeO2/g-C3N4 exhibited a higher apparent rate of 1.2686 min(-1), 7.8 times higher than that of the pure g-C3N4 (0.1621 min(-1)). In addition, it was found that 5% CeO2/g-C3N4 had a new property that it could be used as a sensor for the determination of trace amounts of Cu(2+). Such unique design and one-step synthesis, with an exposed high-activity surface, are important for both technical applications and theoretical investigations.

  17. Thrombus imaging: A comparison of radiolabeled GC4 and T2G1s fibrin-specific monoclonal antibodies

    SciTech Connect

    Rosebrough, S.F.; McAfee, J.G.; Grossman, Z.D.; Kudryk, B.J.; Ritter-Hrncirik, C.A.; Witanowski, L.S.; Maley, B.L.; Bertrand, E.A.; Gagne, G.M. )

    1990-06-01

    Radioimmunoimaging of experimentally-induced canine thrombi has previously been achieved with iodine-131- and indium-111-labeled ({sup 131}I and {sup 111}In) anti-fibrin T2G1s monoclonal antibody (MAb). We now compare T2G1s to another anti-fibrin MAb, designated GC4, for imaging fresh and aged canine thrombi. GC4 is specific for a neoepitope exposed on fibrin later in the thrombolytic process after plasmin digestion. Femoral venous thrombi were induced in six groups of dogs, each containing three dogs. In two groups, the MAbs were compared when the thrombi were 3-hr or 3-days old at the time of injection, and the dogs were killed at 48 hr. In thrombi 3-hr-old, the GC4/T2G1s concentration ratio averaged 0.53 compared to 1.9 in 3-day-old thrombi. Two groups of dogs with thrombi 1- or 3-days-old were heparinized before MAb injection and were killed at 24 hr. The heparinized dogs with thrombi 1- or 3-days-old had GC4/T2G1s mean ratios of 2.3 and 2.9, respectively. In the unheparinized groups, the corresponding ratios were 1.1 and 1.9. GC4 may be more useful for clinical thrombus imaging than T2G1s because spontaneous venous thrombi are usually several days old at the time of presentation and patients are often heparinized immediately.

  18. Sensitive and Specific Immunohistochemical Diagnosis of Human Alveolar Echinococcosis with the Monoclonal Antibody Em2G11

    PubMed Central

    Tappe, Dennis; Stark, Lorenz; Grüner, Beate; Buttenschoen, Klaus; Hillenbrand, Andreas; Juchems, Markus; Henne-Bruns, Doris; Kern, Petra; Seitz, Hanns M.; Möller, Peter; Rausch, Robert L.; Deplazes, Peter

    2012-01-01

    Background Alveolar echinococcosis (AE) is caused by the metacestode stage of Echinococcus multilocularis. Differential diagnosis with cystic echinococcosis (CE) caused by E. granulosus and AE is challenging. We aimed at improving diagnosis of AE on paraffin sections of infected human tissue by immunohistochemical testing of a specific antibody. Methodology/Principal Findings We have analysed 96 paraffin archived specimens, including 6 cutting needle biopsies and 3 fine needle aspirates, from patients with suspected AE or CE with the monoclonal antibody (mAb) Em2G11 specific for the Em2 antigen of E. multilocularis metacestodes. In human tissue, staining with mAb Em2G11 is highly specific for E. multilocularis metacestodes while no staining is detected in CE lesions. In addition, the antibody detects small particles of E. multilocularis (spems) of less than 1 µm outside the main lesion in necrotic tissue, liver sinusoids and lymphatic tissue most probably caused by shedding of parasitic material. The conventional histological diagnosis based on haematoxylin and eosin and PAS stainings were in accordance with the immunohistological diagnosis using mAb Em2G11 in 90 of 96 samples. In 6 samples conventional subtype diagnosis of echinococcosis had to be adjusted when revised by immunohistology with mAb Em2G11. Conclusions/Significance Immunohistochemistry with the mAb Em2G11 is a new, highly specific and sensitive diagnostic tool for AE. The staining of small particles of E. multilocularis (spems) outside the main lesion including immunocompetent tissue, such as lymph nodes, suggests a systemic effect on the host. PMID:23145198

  19. New Findings in a Global Approach to Dissect the Whole Phenotype of PLA2G6 Gene Mutations

    PubMed Central

    Salih, Mustafa A.; Mundwiller, Emeline; Khan, Arif O.; AlDrees, Abdulmajeed; Elmalik, Salah A.; Hassan, Hamdy H.; Al-Owain, Mohammed; Alkhalidi, Hisham M. S.; Katona, Istvan; Kabiraj, Mohammad M.; Chrast, Roman; Kentab, Amal Y.; Alzaidan, Hamad; Rodenburg, Richard J.; Bosley, Thomas M.; Weis, Joachim; Koenig, Michel

    2013-01-01

    Mutations in PLA2G6 gene have variable phenotypic outcome including infantile neuroaxonal dystrophy, atypical neuroaxonal dystrophy, idiopathic neurodegeneration with brain iron accumulation and Karak syndrome. The cause of this phenotypic variation is so far unknown which impairs both genetic diagnosis and appropriate family counseling. We report detailed clinical, electrophysiological, neuroimaging, histologic, biochemical and genetic characterization of 11 patients, from 6 consanguineous families, who were followed for a period of up to 17 years. Cerebellar atrophy was constant and the earliest feature of the disease preceding brain iron accumulation, leading to the provisional diagnosis of a recessive progressive ataxia in these patients. Ultrastructural characterization of patients’ muscle biopsies revealed focal accumulation of granular and membranous material possibly resulting from defective membrane homeostasis caused by disrupted PLA2G6 function. Enzyme studies in one of these muscle biopsies provided evidence for a relatively low mitochondrial content, which is compatible with the structural mitochondrial alterations seen by electron microscopy. Genetic characterization of 11 patients led to the identification of six underlying PLA2G6 gene mutations, five of which are novel. Importantly, by combining clinical and genetic data we have observed that while the phenotype of neurodegeneration associated with PLA2G6 mutations is variable in this cohort of patients belonging to the same ethnic background, it is partially influenced by the genotype, considering the age at onset and the functional disability criteria. Molecular testing for PLA2G6 mutations is, therefore, indicated in childhood-onset ataxia syndromes, if neuroimaging shows cerebellar atrophy with or without evidence of iron accumulation. PMID:24130795

  20. Association between PLA2G12A Polymorphisms and Schizophrenia in a Han Chinese Population from Northeast China

    PubMed Central

    Zhang, Huiping; Yu, Qiong; Wu, Yanhua; Shi, Jieping; Rao, Wenwang; You, Yueyue; Yu, Yaqin

    2016-01-01

    Objective The purpose of this study was to explore the association between single nucleotide polymorphisms (SNPs) in the phospholipase A2 (PLA2), group XIIA gene (PLA2G12A) and schizophrenia. Methods This study included 1,063 schizophrenia patients and 1,103 healthy controls from a Han Chinese Population in Northeast China. Four tagSNPs (rs11728699 in intron 1, synonymous rs2285714 in exon 3, rs3087494 in the 3’ UTR, and rs7694620 in the downstream region) in PLA2G12A were selected, and they were genotyped by the MALDI-TOF-MS technology. The Chi-square (χ2) test and haplotype analysis were performed to analyze the association of PLA2G12A SNPs and schizophrenia using the software packages SPSS 16.0 and Haploview 4.2. Results Among the four tagSNPs, only SNP rs3087494 in the 3’ UTR of PLA2G12A showed significant differences in both allele frequencies (χ2 = 20.136, P<0.001) compared to healthy controls. The minor allele G of SNP rs3087494 is potentially a predictive factor for schizophrenia (OR = 0.753, 95% CI: 0.665–0.882). The frequency distribution of haplotypes consisting of specific alleles of two SNPs (rs7694620-rs3087494 or rs3087494-rs2285714), three SNPs (rs7694620-rs3087494-rs2285714 or rs3087494-rs2285714-rs11728699), or all four SNPs (rs7694620-rs3087494-rs2285714-rs11728699) was significantly different between schizophrenia patients and control subjects (P<0.001). Conclusions Our study demonstrated that PLA2G12A SNPs or haplotypes might influence the susceptibility to schizophrenia in the Han Chinese population from Northeast China. PMID:27434078

  1. Assembling different antennas of the gp120 high mannose-type glycans on gold nanoparticles provides superior binding to the anti-HIV antibody 2G12 than the individual antennas.

    PubMed

    Chiodo, Fabrizio; Enríquez-Navas, Pedro M; Angulo, Jesús; Marradi, Marco; Penadés, Soledad

    2015-03-20

    In order to re-build Man9GlcNAc2 clusters of the HIV gp120 glycoprotein, ∼2 nm gold glyconanoparticles (GNPs) were coated with the synthetic partial structures of Man9, the tetramannoside Manα1-2Manα1-2Manα1-3Manα1- and the pentamannoside Manα1-2Manα1-3[Manα1-2Manα1-6]Manα1-. Their interactions with the anti-HIV broadly neutralizing antibody 2G12 were studied by surface plasmon resonance (SPR)-based biosensors and saturation transfer difference (STD)-NMR spectroscopy. A synergistic effect of the tetra- and pentamannosides multimerized on a same GNP was observed. The assembly of these antennas of the gp120 high-mannose type glycan on GNPs provided superior binding to the anti-HIV antibody 2G12 with respect to GNPs carrying only the individual oligomannosides. The results presented in this work provide new molecular information on the interactions between clusters of oligomannosides and 2G12 that could help in the design of a carbohydrate-based vaccine against HIV.

  2. Electrocurtain coating process for coating solar mirrors

    DOEpatents

    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.

  3. Electronic, magnetic, and optical characteristics of half-semiconductor double perovskite oxide Sr2CrOsO6 governed by 3d (t2g3)-5d (t2g3) antiferromagnetic coupling

    NASA Astrophysics Data System (ADS)

    H.-E., M. Musa Saad

    2016-07-01

    In this study, motivated by observations of the remarkable magnetic insulating nature and high Curie temperature (TC=725 K) of double perovskite oxide Sr2CrOsO6, the electronic, magnetic, and optical characteristics of Sr2CrOsO6 were determined using the full potential linear muffin-tin orbital method according to density functional theory. The spin-orbit coupling contribution was included in the local spin density approximation (LSDA) and generalized gradient approximation (GGA). In addition, the Coulomb repulsion (U) and Hund's exchange (J) energies were considered in both methods (LSDA+U and GGA+U). Full structural optimization confirmed that the ground state of Sr2CrOsO6 is face-centered cubic (Fm-3m symmetry). Calculations predicted that Sr2CrOsO6 is ferrimagnetic half-semiconductive (HSC) due to the vertical hopping of t2g electrons via antiferromagnetic coupling [Cr3+ (t2g3↑)-O (2pπ)-Os5+ (t2g3↓)], which agreed with the experimental results. The HSC energy-gaps originate from the splitting of three partially occupied Os5+ (5d) bands into two fully filled bands and one empty spin-down band. The real ε1 (ω) and imaginary ε2 (ω) parts of the dielectric function ε (ω) and energy-loss spectrum L (ω) were calculated, analyzed, and compared with the electronic results.

  4. Multi-layer coatings

    DOEpatents

    Maghsoodi, Sina; Brophy, Brenor L.; Abrams, Ze'ev R.; Gonsalves, Peter R.

    2016-06-28

    Disclosed herein are coating materials and methods for applying a top-layer coating that is durable, abrasion resistant, highly transparent, hydrophobic, low-friction, moisture-sealing, anti-soiling, and self-cleaning to an existing conventional high temperature anti-reflective coating. The top coat imparts superior durability performance and new properties to the under-laying conventional high temperature anti-reflective coating without reducing the anti-reflectiveness of the coating. Methods and data for optimizing the relative thickness of the under-layer high temperature anti-reflective coating and the top-layer thickness for optimizing optical performance are also disclosed.

  5. Critical current anisotropy and pinning in (103) YBCO superconducting thin films on SrTiO3(110) substrates

    NASA Astrophysics Data System (ADS)

    Wu, K. H.; Huang, S. J.; Wang, S. J.; Chen, S. P.; Juang, J. Y.; Uen, T. M.; Gou, Y. S.

    1996-03-01

    High quality (103) oriented YBCO superconducting thin films with T c ≈89 K have been prepared by pulsed laser deposition on SrTiO3(110) substrates. The grain morphology of the films, as revealed by both scanning electron microscopy and atomic force microscopy, shows distinct brick wall structure. The critical current densities measured along (001) direction of the substrates are about an order of magnitude higher than that measured on the other in-plane direction with no apparent weak- link behavior observed. The critical current densities in both directions, however, show a similar linear temperature dependence over a wide temperature range, indicative of a flux-creep limited mechanism. The creep rate in both cases, as fit to the Anderson-Kim creep model, is of order of 1 which is about an order of magnitude higher than that of conventional type-II superconductors. Samples co-ablated with silver were also studied. Detail mechanisms of pinning as wall as grain morphology evolutions are discussed.

  6. Superconductor-Mediated Modification of Gravity? AC Motor Experiments with Bulk YBCO Disks in Rotating Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Koczor, Ronald J.; Roberson, Rick

    1998-01-01

    We have previously reported results using a high precision gravimeter to probe local gravity changes in the neighborhood of large bulk-processed high-temperature superconductors. Podkietnov, et al (Podkietnov, E. and Nieminen, R. (1992) A Possibility of Gravitational Force Shielding by Bulk YBa2 Cu3 O7-x Superconductor, Physica C, C203:441-444.) have indicated that rotating AC fields play an essential role in their observed distortion of combined gravity and barometric pressure readings. We report experiments on large (15 cm diameter) bulk YBCO ceramic superconductors placed in the core of a three-phase, AC motor stator. The applied rotating field produces up to a 12,000 revolutions per minute magnetic field. The field intensity decays rapidly from the maximum at the outer diameter of the superconducting disk (less than 60 Gauss) to the center (less than 10 Gauss). This configuration was applied with and without a permanent DC magnetic field levitating the superconducting disk, with corresponding gravity readings indicating an apparent increase in observed gravity of less than 1 x 10(exp -6)/sq cm, measured above the superconductor. No effect of the rotating magnetic field or thermal environment on the gravimeter readings or on rotating the superconducting disk was noted within the high precision of the observation. Implications for propulsion initiatives and power storage flywheel technologies for high temperature superconductors will be discussed for various spacecraft and satellite applications.

  7. Feasibility study for reduction of the screening current induced field in a 2G high temperature superconducting coil

    NASA Astrophysics Data System (ADS)

    Hwang, Y. J.; Jang, J. Y.; Ahn, M. C.; Park, Y. G.; Lee, S. G.

    2016-10-01

    This paper reports the effects of thermal energy on reducing the overshoot of the current sweep cycle method to reduce the screening current-induced field (SCF) in a 2G high temperature superconducting (HTS) coil. A disadvantage of the current sweep cycle method is the necessity for large overshoot in the coil current. For a 2G HTS coil, excessive overshooting of the coil current is undesirable (Yanagisawa et al 2012 AIP Conf. Proc. 1434 1373-8). In an effort to circumvent this overshooting problem, the thermal energy effect was investigated in combination with the current sweep cycle method based on experiments in this study. The experimental results show that greater SCF reduction in the HTS coil was obtained upon increasing thermal energy by heater current.

  8. Quantitative visualization of biological data in Google Earth using R2G2, an R CRAN package.

    PubMed

    Arrigo, Nils; Albert, Loren P; Mickelson, Pascal G; Barker, Michael S

    2012-11-01

    We briefly introduce R2G2, an R CRAN package to visualize spatially explicit biological data within the Google Earth interface. Our package combines a collection of basic graph-editing features, including automated placement of dots, segments, polygons, images (including graphs produced with R), along with several complex three-dimensional (3D) representations such as phylogenies, histograms and pie charts. We briefly present some example data sets and show the immediate benefits in communication gained from using the Google Earth interface to visually explore biological results. The package is distributed with detailed help pages providing examples and annotated source scripts with the hope that users will have an easy time using and further developing this package. R2G2 is distributed on http://cran.r-project.org/web/packages. PMID:22994899

  9. Purification and Characterization of a Fibrinolytic Enzyme from Bacillus pumilus 2.g Isolated from Gembus, an Indonesian Fermented Food

    PubMed Central

    Afifah, Diana Nur; Sulchan, Muhammad; Syah, Dahrul; Yanti; Suhartono, Maggy Thenawidjaja; Kim, Jeong Hwan

    2014-01-01

    Bacillus pumilus 2.g isolated from gembus, an Indonesian fermented soybean cake, secretes several proteases that have strong fibrinolytic activities. A fibrinolytic enzyme with an apparent molecular weight of 20 kDa was purified from the culture supernatant of B. pumilus 2.g by sequential application of ammonium sulfate precipitation, ion-exchange chromatography, and hydrophobic chromatography. The partially purified enzyme was stable between pH 5 and pH 9 and temperature of less than 60°C. Fibrinolytic activity was increased by 5 mM MgCl2 and 5 mM CaCl2 but inhibited by 1 mM phenylmethylsulfonyl fluoride (PMSF), 1 mM sodium dodecyl sulfate (SDS), and 1 mM ethylenediaminetetraacetic acid (EDTA). The partially purified enzyme quickly degraded the α and β chains of fibrinogen but was unable to degrade the γ chain. PMID:25320719

  10. Dissolved inorganic carbon and stable carbon isotopic evolution of neutral mine drainage interacting with atmospheric CO2(g).

    PubMed

    Abongwa, Pride Tamasang; Atekwana, Eliot Anong; Puckette, James

    2016-03-01

    We investigated the spatial variations in the concentrations of dissolved inorganic carbon (DIC), the stable carbon isotopic composition (δ(13)C) of DIC and the δ(13)C of carbonate precipitated from neutral mine drainage interacting with the atmospheric CO2(g). We assessed the chemical, DIC and δ(13)CDIC evolution of the mine drainage and the δ(13)C evolution of carbonate precipitates for a distance of 562 m from the end of an 8 km tunnel that drains a mine. Our results show that as the mine drainage interacts with atmospheric CO2(g) the outgassing of CO2 due to the high initial partial pressure of CO2 (pCO2) causes the DIC to evolve under kinetic conditions followed by equilibration and then under equilibrium conditions. The carbonate evolution was characterized by spatial increases in pH, decreasing concentrations of Ca(2+) and DIC and by the precipitation of carbonate. The δ(13)CDIC showed a larger enrichment from the tunnel exit to 38 m, moderate continuous enrichment to 318 m and almost no enrichment to 562 m. On the other hand, the δ(13)C of the carbonate precipitates also showed large enrichment from the tunnel exit to 38 m, moderate enrichment to 318 m after which the δ(13)C remained nearly constant. The enrichment in the δ(13)C of the DIC and the carbonate precipitates from 0 to 38 m from kinetic fractionation caused by CO2(g) outgassing was followed by a mix of kinetic fractionation and equilibrium fractionation controlled by carbon exchange between DIC and atmospheric CO2(g) to 318 m and then by equilibrium fractionation from 318 to 562 m. From the carbonate evolution in this neutral mine drainage, we estimated that 20% of the carbon was lost via CO2 outgassing, 12% was sequestered in sediments in the drainage ponds from calcite precipitation and the remainder 68% was exported to the local stream.

  11. Coating life prediction

    NASA Technical Reports Server (NTRS)

    Nesbitt, James A.; Gedwill, Michael A.

    1985-01-01

    The investigation combines both experimental studies and numerical modeling to predict coating life in an oxidizing environment. The experimental work provides both input to and verification of two numerical models. The coatings being examined are an aluminide coating on Udimet 700 (U-700), a low-pressure plasma spray (LPPS) Ni-18Co-17Cr-24Al-0.2Y overlay coating also on U- 700, and bulk deposits of the LPPS NiCoCrAlY coating.

  12. Introduction of germline residues improves the stability of anti-HIV mAb 2G12-IgM

    PubMed Central

    Chromikova, Veronika; Mader, Alexander; Hofbauer, Stefan; Göbl, Christoph; Madl, Tobias; Gach, Johannes S.; Bauernfried, Stefan; Furtmüller, Paul G.; Forthal, Donald N.; Mach, Lukas; Obinger, Christian; Kunert, Renate

    2015-01-01

    Immunoglobulins M (IgMs) are gaining increasing attention as biopharmaceuticals since their multivalent mode of binding can give rise to high avidity. Furthermore, IgMs are potent activators of the complement system. However, they are frequently difficult to express recombinantly and can suffer from low conformational stability. Here, the broadly neutralizing anti-HIV-1 antibody 2G12 was class-switched to IgM and then further engineered by introduction of 17 germline residues. The impact of these changes on the structure and conformational stability of the antibody was then assessed using a range of biophysical techniques. We also investigated the effects of the class switch and germline substitutions on the ligand-binding properties of 2G12 and its capacity for HIV-1 neutralization. Our results demonstrate that the introduced germline residues improve the conformational and thermal stability of 2G12-IgM without altering its overall shape and ligand-binding properties. Interestingly, the engineered protein was found to exhibit much lower neutralization potency than its wild-type counterpart, indicating that potent antigen recognition is not solely responsible for IgM-mediated HIV-1 inactivation. PMID:25748881

  13. Fiber size, type, and myosin heavy chain content in rhesus hindlimb muscles after 2 weeks at 2 G

    NASA Technical Reports Server (NTRS)

    Tavakol, Morteza; Roy, Roland R.; Kim, Jung A.; Zhong, Hui; Hodgson, John A.; Hoban-Higgins, Tana M.; Fuller, Charles A.; Edgerton, V. Reggie

    2002-01-01

    BACKGROUND: Fiber atrophy and an increase in the percentage of fast fibers have been observed in Rhesus leg muscles after spaceflight. Hypothesis: Hypergravity will result in muscle fiber hypertrophy and an increase in the percentage of slow fibers. METHODS: Open muscle biopsies were obtained from Rhesus soleus, medial gastrocnemius (MG), and tibialis anterior (TA) muscles before and after 14 d of centrifugation (2 G) and in time-matched controls. Cage activity levels were measured by telemetry. RESULTS: Based on monoclonal antibody binding for myosin heavy chains (MHC), the fastest region of soleus contained a higher proportion of type I+II (27 vs. 13%) and had a tendency for a lower proportion of type I (38 vs. 61%, p = 0.10) fibers after than before centrifugation. There was a higher proportion of type I+II fibers in post- vs. pre-2 G (10 vs. 0.6%) MG biopsies. Fiber type distribution and MHC composition were unaffected in the TA. Overall, mean fiber sizes were unaffected by centrifugation. Average cage activity levels were 36% lower during than before 2 G. CONCLUSIONS: Our hypothesis was rejected. The changes in the proportion of fibers expressing type I MHC are the reverse of that expected with chronic loading of extensors and, paradoxically, are similar to changes observed with chronic unloading, such as occurs during spaceflight, in this primate model. The data are consistent with the observed decrease in total daily activity levels.

  14. Magnetic field orientation dependence of flux pinning in (Gd,Y)Ba2Cu3O7-x coated conductor with tilted lattice and nanostructures

    SciTech Connect

    Zhang, Yifei; Specht, Eliot D; Cantoni, Claudia; Christen, David K; Zuev, Yuri L; Goyal, Amit; Sinclair, J.; Thompson, James R; Aytug, Tolga; Paranthaman, Mariappan Parans; Chen, Y; Selvamanickam, V.

    2009-01-01

    The dependence of the critical current density (J{sub c}) on the orientation of an applied magnetic field was studied for a prototype (Gd,Y)Ba{sub 2}Cu{sub 3}O{sub 7?x} (GdYBCO) coated conductor fabricated by MOCVD on an IBAD-MgO template. Additional rare-earth cations (Y and Gd) and Zr were incorporated into the superconducting film to form (Y,Gd){sub 2}O{sub 3} and BaZrO{sub 3} nanoparticles extended nearly parallel to the a-b planes and to the c-axis, respectively, to enhance the flux pinning. In-field measurement of J{sub c} was carried out with electrical current flowing either along or perpendicular to the longitudinal axis of the tape, while a maximum Lorentz force configuration was always maintained. Details in the angular dependence of J{sub c} were related to the unique structure of the film, specifically the tilt in the GdYBCO lattice and the tilts in the extended (Y,Gd){sub 2}O{sub 3} and BaZrO{sub 3} nanoparticles. XRD and TEM were used to study the structure of the coated conductor. The effect of the misalignment between the external field H and the internal field B on the angular dependence of J{sub c} is discussed.

  15. A Herpes Simplex Virus 2 (HSV-2) gD Mutant Impaired for Neural Tropism Is Superior to an HSV-2 gD Subunit Vaccine To Protect Animals from Challenge with HSV-2

    PubMed Central

    Goodman, Kyle N.; Li, Daniel Y.; Raffeld, Mark; Chavez, Mayra

    2015-01-01

    ABSTRACT A recent phase 3 trial with soluble herpes simplex virus 2 (HSV-2) glycoprotein D (gD2t) in adjuvant failed to show protection against genital herpes. We postulated that live attenuated HSV-2 would provide more HSV antigens for induction of virus-specific antibodies and cellular immunity than would gD2t. We previously reported an HSV-2 mutant, HSV2-gD27, in which the nectin-1 binding domain of gD2 is altered so that the virus is impaired for infecting neural cells, but not epithelial cells, in vitro and is impaired for infecting dorsal root ganglia in mice (K. Wang, J. D. Kappel, C. Canders, W. F. Davila, D. Sayre, M. Chavez, L. Pesnicak, and J. I. Cohen, J Virol 86:12891–12902, 2012, doi:10.1128/JVI.01055-12). Here we report that the mutations in HSV2-gD27 were stable when the virus was passaged in cell culture and during acute infection of mice. HSV2-gD27 was attenuated in mice when it was inoculated onto the cornea, intramuscularly (i.m.), intravaginally, and intracranially. Vaccination of mice i.m. with HSV2-gD27 provided better inhibition of challenge virus replication in the vagina than when the virus was used to vaccinate mice intranasally or subcutaneously. Comparison of i.m. vaccinations with HSV2-gD27 versus gD2t in adjuvant showed that HSV2-gD27 induced larger reductions of challenge virus replication in the vagina and reduced latent viral loads in dorsal root ganglia but induced lower serum neutralizing antibody titers than those obtained with gD2t in adjuvant. Taken together, our data indicate that a live attenuated HSV-2 vaccine impaired for infection of neurons provides better protection from vaginal challenge with HSV-2 than that obtained with a subunit vaccine, despite inducing lower titers of HSV-2 neutralizing antibodies in the serum. IMPORTANCE Genital herpes simplex is one of the most prevalent sexually transmitted diseases. Though HSV-2 disease is usually mild, it can be life threatening in neonates and immunocompromised persons. In

  16. Flow coating apparatus and method of coating

    SciTech Connect

    Hanumanthu, Ramasubrahmaniam; Neyman, Patrick; MacDonald, Niles; Brophy, Brenor; Kopczynski, Kevin; Nair, Wood

    2014-03-11

    Disclosed is a flow coating apparatus, comprising a slot that can dispense a coating material in an approximately uniform manner along a distribution blade that increases uniformity by means of surface tension and transfers the uniform flow of coating material onto an inclined substrate such as for example glass, solar panels, windows or part of an electronic display. Also disclosed is a method of flow coating a substrate using the apparatus such that the substrate is positioned correctly relative to the distribution blade, a pre-wetting step is completed where both the blade and substrate are completed wetted with a pre-wet solution prior to dispensing of the coating material onto the distribution blade from the slot and hence onto the substrate. Thereafter the substrate is removed from the distribution blade and allowed to dry, thereby forming a coating.

  17. Reel-to-reel deposition of epitaxial double-sided MgO buffer layers for coated conductors

    NASA Astrophysics Data System (ADS)

    Xue, Yan; Xiong, Jie; Zhang, Yahui; Zhang, Fei; Zhao, Rui-Peng; Hui, Wang; Wang, Quiling; Cheng, Guo; Zhao, Xiao-Hui; Tao, Bo-Wan

    2016-06-01

    We have successfully employed a double-sided process to deposit MgO buffer layers on both sides of amorphous Y2O3 surface for double-sided YBa2Cu3O7-δ (YBCO) coated conductors (CCs) for the first time, the structure of which is of great prospect to improve the performance and cut the production cost. The biaxial textures of MgO buffer layer are noticeably affected by the ion energy and film thickness, which is demonstrated by X-ray diffraction. The best biaxial texture of double-sided MgO films shows ω-scan of (002) MgO and Φ-scan of (220) MgO yield full width at half maximum values of 4° and 7.8° for one side, respectively, as well as 3.5° and 6.7° for the other side. The subsequent double-sided YBCO films are deposited on the as-prepared MgO template with entire critical current of over 300 A/cm for both sides.

  18. Stabilization of the high-temperature phases in ceramic coatings on zirconium alloy produced by plasma electrolytic oxidation

    NASA Astrophysics Data System (ADS)

    Apelfeld, A. V.; Betsofen, S. Y.; Borisov, A. M.; Vladimirov, B. V.; Savushkina, S. V.; Knyazev, E. V.

    2016-09-01

    The composition and structure of ceramic coatings obtained on Zr-1%Nb alloy by plasma electrolytic oxidation (PEO) in aqueous electrolyte comprising 2 g/L KOH, 6 g/L NaAlO2 and 2 g/L Na2SiO3 with addition of yttria nanopowder, have been studied. The PEO coatings of thickness ∼⃒20 μm were studied using scanning electron microscopy, X-ray microanalysis and X-ray phase analysis. Additives in the electrolyte of yttria nanopowder allowed stabilizing the high-temperature tetragonal and cubic zirconia in the coating.

  19. Quantitation of Bone Growth Rate Variability in Rats Exposed to Micro-(near zero G) and Macrogravity (2G)

    NASA Technical Reports Server (NTRS)

    Bromage, Timothy G.; Doty, Stephen B.; Smolyar, Igor; Holton, Emily

    1997-01-01

    Our stated primary objective is to quantify the growth rate variability of rat lamellar bone exposed to micro- (near zero G: e.g., Cosmos 1887 & 2044; SLS-1 & SLS-2) and macrogravity (2G). The primary significance of the proposed work is that an elegant method will be established that unequivocally characterizes the morphological consequences of gravitational factors on developing bone. The integrity of this objective depends upon our successful preparation of thin sections suitable for imaging individual bone lamellae, and our imaging and quantitation of growth rate variability in populations of lamellae from individual bone samples.

  20. Quantification of Bone Growth Rate Variability in Rats Exposed to Micro- (near zero G) and Macrogravity (2G)

    NASA Technical Reports Server (NTRS)

    Bromage, Timothy G.; Doty, Stephen B.; Smolyar, Igor; Holton, Emily

    1996-01-01

    Our stated primary objective is to quantify the growth rate variability of rat lamellar bone exposed to micro and macrogravity (2G). The primary significance of the proposed work is that an elegant method will be established that unequivocally characterizes the morphological consequences of gravitational factors on developing bone. The integrity of this objective depends upon our successful preparation of thin sections suitable for imaging individual bone lamellae, and our imaging and quantitation of growth rate variability in populations of lamellae from individual bone samples.

  1. Epitaxial growth and thermal dynamics of CeO II buffer layer on textured Ni-W substrates for YBCO coated conductors

    NASA Astrophysics Data System (ADS)

    Pan, C. Y.; Cai, C. B.; Ying, L. L.; Lu, Y. M.; Liu, Z. Y.; Gao, B.; Liu, J. L.

    2008-02-01

    In present study, the biaxially textured CeO II buffer layers on Ni-W substrates have been prepared by chemical solution deposition (CSD) with cerium acetate as the starting precursor, mixed with solvents of Propionic acid, Isopropanol and Acetylacetone. Typical XRD θ-2θ scans and the pole figure display well out-of-plane and in-plane textures of CeO II films. SEM and AFM results suggest that the buffer layer have uniform and smooth surface. Meanwhile, the effects of heating rate on CeO II formation starting from the precursor solution have been studied using differential thermal analysis (DTA). And the further analysis is given by XRD results for precursor xrogel at the corresponding temperature. Detailed high temperature optical microscope (HTOM) photographs investigate the surface characteristics evolved with temperature.

  2. Corrosion inhibiting organic coatings

    SciTech Connect

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  3. Experiments with ceramic coatings

    NASA Technical Reports Server (NTRS)

    Lynn, E. K.; Rollins, C. T.

    1968-01-01

    Report describes the procedures and techniques used in the application of a ceramic coating and the evaluation of test parts through observation of the cracks that occur in this coating due to loading.

  4. Thermal barrier coating system

    NASA Technical Reports Server (NTRS)

    Stecura, S. (Inventor)

    1984-01-01

    A high temperature oxidation resistant, thermal barrier coating system is disclosed for a nickel cobalt, or iron base alloy substrate. An inner metal bond coating contacts the substrate, and a thermal barrier coating covers the bond coating. NiCrAlR, FeCrAlR, and CoCrAlR alloys are satisfactory as bond coating compositions where R=Y or Yb. These alloys contain, by weight, 24.9-36.7% chromium, 5.4-18.5% aluminum, and 0.05 to 1.55% yttrium or 0.05 to 0.53% ytterbium. The coatings containing ytterbium are preferred over those containing yttrium. An outer thermal barrier coating of partial stabilized zirconium oxide (zirconia) which is between 6% and 8%, by weight, of yttrium oxide (yttria) covers the bond coating. Partial stabilization provides a material with superior durability. Partially stabilized zirconia consists of mixtures of cubic, tetragonal, and monoclinic phases.

  5. Measurement of transverse Jc profiles of coated conductors using a magnetic knife of permanent magnets

    SciTech Connect

    Haenisch, J; Mueller, F M; Ashworth, S P; Coulter, J Y; Matias, Vlad

    2008-01-01

    The transverse J{sub c} distribution in YBCO coated conductors was measured non-destructively with high resolution using a 'magnetic knife' made of permanent magnets. 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 the sample in order to reveal the critical-current density distribution. The net resolution of this device is approximately 65 {micro}m, and the J{sub c} resolution is better than 0.5%. A Fourier series inversion process was used to determine the transverse J{sub c} distribution in the sample. The J{sub c} profile was correlated with other sample properties of coated conductors prepared by pulsed laser deposition. Because of its straight-forward and inexpensive design, this J{sub c} imaging technique can be a powerful tool for quality control in coated-conductor production.

  6. Development of a new method to get a reliable powder flow characteristics using only 1 to 2 g of powder.

    PubMed

    Seppälä, Kari; Heinämäki, Jyrki; Hatara, Juha; Seppälä, Lassi; Yliruusi, Jouko

    2010-03-01

    In powder technology, it is often important to directly measure real powder flow rate from a small amount of powder. For example, in pharmaceutical industry, a frequent problem is to determine powder flow properties of new active pharmaceutical ingredient (API) in an early stage of the development when the amount of API is limited. The purpose of this paper is to introduce a new direct method to measure powder flow when the material is poorly flowing (cohesive) and the amount of material is about 1 to 2 g. The measuring system was simple, consisting of a flow chamber and electronic balance and an automated optical detection system, and for each measurement, only 1 to 2 g of sample was required. Based on the results obtained with this testing method, three selected sugar excipients, three grades of microcrystalline cellulose, and APIs (caffeine, carbamazepine, and paracetamol) can be classified as freely flowing, intermediate flowing, and poorly flowing powders, respectively. The average relative standard deviation for the flow time determinations was not more than 2-10%. The present novel flowability testing method provides a new tool for a rapid determination of flowing characteristics of powders (e.g., inhalation powders) and granules at a small scale.

  7. Contribution of N-linked glycans on HSV-2 gB to cell–cell fusion and viral entry

    SciTech Connect

    Luo, Sukun; Hu, Kai; He, Siyi; Wang, Ping; Zhang, Mudan; Huang, Xin; Du, Tao; Zheng, Chunfu; Liu, Yalan; Hu, Qinxue

    2015-09-15

    HSV-2 is the major cause of genital herpes and its infection increases the risk of HIV-1 acquisition and transmission. HSV-2 glycoprotein B together with glycoproteins D, H and L are indispensable for viral entry, of which gB, as a class III fusogen, plays an essential role. HSV-2 gB has seven potential N-linked glycosylation (N-CHO) sites, but their significance has yet to be determined. For the first time, we systematically analyzed the contributions of N-linked glycans on gB to cell–cell fusion and viral entry. Our results demonstrated that, of the seven potential N-CHO sites on gB, mutation at N390, N483 or N668 decreased cell–cell fusion and viral entry, while mutation at N133 mainly affected protein expression and the production of infectious virus particles by blocking the transport of gB from the endoplasmic reticulum to Golgi. Our findings highlight the significance of N-linked glycans on HSV-2 gB expression and function. - Highlights: • N-linked glycan at N133 is important for gB intracellular trafficking and maturation. • N-linked glycans at N390, N483 and N668 on gB are necessary for optimal cell–cell fusion. • N-linked glycans at N390, N483 and N668 on gB are necessary for optimal viral entry.

  8. [Results of a post-marketing surveillance of meropenem administered over 2 g/day for serious infectious diseases].

    PubMed

    Wakisaka, Koji; Tani, Shunsuke; Ishibashi, Kazuo; Nukui, Kazuhiko; Nagao, Munehiko

    2015-10-01

    The post-marketing surveillance of meropenem (Meropen®) administered over 2g/day for serious infectious diseases was conducted between August 2011 and June 2013 to evaluate safety and efficacy under actual clinical use. There were 382 and 322 evaluable cases for safety and efficacy respectively, of 399 case cards collected from 87 institutions. In safety analysis, the incidence of adverse drug reactions (ADRs) associated with use of meropenem (including abnormal laboratory findings) was 19.1% (73/382 cases), and the main ADRs were hepatic function abnormal, aspartate aminotransferase increased, alanine aminotransferase increased, liver disorder, and diarrhoea, which were similar to these observed in the post-marketing surveillances of meropenem conducted before. In efficacy analysis, the efficacy was 73.6% (237/322 cases), which is as same as 71.4% (3214/4504 cases) of post-marketing surveillance of meropenem conducted after first approval under 2 g/day for infectious diseases. These results confirmed meropenem (Meropen®) is one of the useful antimicrobial agents for serious infectious diseases.

  9. Basic fibroblast growth factor is pro-adipogenic in rat skeletal muscle progenitor clone, 2G11 cells.

    PubMed

    Nakano, Shin-ichi; Nakamura, Katsuyuki; Teramoto, Naomi; Yamanouchi, Keitaro; Nishihara, Masugi

    2016-01-01

    Intramuscular adipose tissue (IMAT) formation is a hallmark of marbling in cattle. IMAT is considered to originate from skeletal muscle progenitor cells with adipogenic potential. However, the mechanism involved in IMAT formation from these progenitor cells in vivo remains unclear. In the present study, among the growth factors tested, which were known to be expressed in skeletal muscle, we found only basic fibroblast growth factor (bFGF) has a pro-adipogenic effect on skeletal muscle derived adipogenic progenitor clone, 2G11 cells. Pre-exposure of 2G11 cells to bFGF did not affect initial gene expressions of CCAAT/enhancer-binding protein (C/EBP)β and C/EBPδ, while resulting in an enhancement of subsequent expressions of C/EBPα and proliferator-activated receptor gamma (PPARγ) during adipogenesis, indicating that bFGF is acting on the transcriptional regulation of C/EBPα and PPARγ. In addition, the effect of bFGF is mediated via two types of FGF receptor (FGFR) isoforms: FGFR1 and FGFR2 IIIc, and both receptors are prerequisite for bFGF to express its pro-adipogenic effect. These results suggest that bFGF plays an important role as a key trigger of IMAT formation in vivo.

  10. Crystal structure of the HIV neutralizing antibody 2G12 in complex with a bacterial oligosaccharide analog of mammalian oligomannose

    PubMed Central

    Stanfield, Robyn L; De Castro, Cristina; Marzaioli, Alberto M; Wilson, Ian A; Pantophlet, Ralph

    2015-01-01

    Human immunodeficiency virus-1 (HIV-1) is a major public health threat that continues to infect millions of people worldwide each year. A prophylactic vaccine remains the most cost-effective way of globally reducing and eliminating the spread of the virus. The HIV envelope spike, which is the target of many vaccine design efforts, is densely mantled with carbohydrate and several potent broadly neutralizing antibodies to HIV-1 recognize carbohydrate on the envelope spike as a major part of their epitope. However, immunizing with recombinant forms of the envelope glycoprotein does not typically elicit anti-carbohydrate antibodies. Thus, studies of alternative antigens that may serve as a starting point for carbohydrate-based immunogens are of interest. Here, we present the crystal structure of one such anti-carbohydrate HIV neutralizing antibody (2G12) in complex with the carbohydrate backbone of the lipooligosaccharide from Rhizobium radiobacter strain Rv3, which exhibits a chemical structure that naturally mimics the core high-mannose carbohydrate epitope of 2G12 on HIV-1 gp120. The structure described here provides molecular evidence of the structural homology between the Rv3 oligosaccharide and highly abundant carbohydrates on the surface of HIV-1 and raises the potential for the design of novel glycoconjugates that may find utility in efforts to develop immunogens for eliciting carbohydrate-specific neutralizing antibodies to HIV. PMID:25380763

  11. METHOD FOR TESTING COATINGS

    DOEpatents

    Johns, I.B.; Newton, A.S.

    1958-09-01

    A method is described for detecting pin hole imperfections in coatings on uranium-metal objects. Such coated objects are contacted with a heated atmosphere of gaseous hydrogen and imperfections present in the coatings will allow the uranlum to react with the hydrogen to form uranium hydride. Since uranium hydride is less dense than uranium metal it will swell, causing enlargement of the coating defeot and rendering it visible.

  12. Coatings for laser fusion

    SciTech Connect

    Lowdermilk, W.H.

    1981-12-18

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors.

  13. Spin coating of electrolytes

    DOEpatents

    Stetter, Joseph R.; Maclay, G. Jordan

    1989-01-01

    Methods for spin coating electrolytic materials onto substrates are disclosed. More particularly, methods for depositing solid coatings of ion-conducting material onto planar substrates and onto electrodes are disclosed. These spin coating methods are employed to fabricate electrochemical sensors for use in measuring, detecting and quantifying gases and liquids.

  14. Ceramic with zircon coating

    NASA Technical Reports Server (NTRS)

    Wang, Hongyu (Inventor)

    2003-01-01

    An article comprises a silicon-containing substrate and a zircon coating. The article can comprise a silicon carbide/silicon (SiC/Si) substrate, a zircon (ZrSiO.sub.4) intermediate coating and an external environmental/thermal barrier coating.

  15. PIT Coating Requirements Analysis

    SciTech Connect

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  16. Highlights in R&D for coated conductors in Japan

    NASA Astrophysics Data System (ADS)

    Shiohara, Yuh; Kitoh, Yutaka; Izumi, Teruo

    2006-10-01

    The current 5-year national project since 2003 for development of coated conductors (CC) using Y-system superconductors has passed for almost a half term and has achieved satisfactory results. In this paper, the current status and the future prospect are reviewed. The group of Fujikura Ltd. and SRL-ISTEC has worked on the long tape with high performance in the PLD-YBCO superconducting tapes on the IBAD-Gd2Zr2O7 buffered substrates. The highest value on the product of Ic × L in the world was marked by the result which were 51,940 A m (212 m × 245 A) by the SRL group. Fujikura Ltd. also realized the longest tape of 200 m with a reasonable high Ic value of 100 A. The values have been steadily improved and the trend is going to be continued, since the large equipments for both IBAD and PLD have been installed, and ready to work on large tapes with a high production rate. In another group, the long tape processing has been developed focusing on lowering the production cost. The extremely high Ic value of 470 A was obtained in the film by the TFA-MOD method on CeO2 (PLD)/GZO(IBAD)/hastelloy substrate. In the efforts for the long tape in the process, a 25 m long tape with its Ic value of 100 A was realized by a continuous reel-to-reel system. Additionally, 100 m class long tapes were also obtained by the MOCVD and PLD-HoBCO processes. Both groups are aiming to achieve the final goals of 500 m long tapes with the high Ic value of 300 A/cm-w by the production rate of 5 m/h. Furthermore, the feasibility study for applications using coated conductors has been already started due to the above-mentioned success of long tape production. Several kinds of coils using long coated conductors such as a solenoid and a pancake coils and the spiral shaped conductors for cable applications were firstly made. Reasonable high performances were confirmed in the trials. For the future plans of coated conductor applications, the following power devices using coated conductors have been

  17. Capillary electrophoresis of affinity complexes between subviral 80S particles of human rhinovirus and monoclonal antibody 2G2.

    PubMed

    Kremser, Leopold; Petsch, Martina; Blaas, Dieter; Kenndler, Ernst

    2006-07-01

    Human rhinoviruses (HRVs), the main etiologic agents of the common cold, transform into subviral B- or 80S particles (they sediment at 80S upon sucrose density gradient centrifugation) during infection and, in vitro, upon exposure to a temperature between 50 and 56 degrees C. With respect to the native virion they lack the genomic RNA and the viral capsid protein VP4. 80S particles are unstable and easily disintegrate into their components, VP1, VP2, and VP3 in buffers containing SDS. However, this detergent was found to be a necessary constituent of the BGE for the analysis of these viruses and their complexes with receptors and antibodies by CE. We here demonstrate that dodecylpoly(ethyleneglycol ether) (D-PEG) a nonionic detergent, is suitable for analysis of subviral particles as it preserves their integrity, in contrast to SDS. Electrophoresis of the 80S particles in borate buffer (pH 8.3, 100 mM) containing 10 mM D-PEG resulted in a well-defined electrophoretic peak. The identity of the peak was confirmed, among other means, by complexation with mAb 2G2, which recognizes a structural epitope exclusively present on subviral particles but not on native virus. Upon incubation of the 80S particles with mAb 2G2 the peak disappeared, but a new peak, attributed to the antibody complex emerged. The separation system allowed following the time course of the transformation of intact HRV serotype 2 into 80S particles upon incubation at temperatures between 40 and 65 degrees C. We also demonstrate that subviral particles derived from HRV2 labeled with the fluorescence dyes FITC or Cy3.5 were stable in the separation system containing D-PEG. Dye-modified particles were still recognized by mAb 2G2, suggesting that the exposed lysines that are derivatized by the reagent do not form part of the epitope of the antibody.

  18. Functional Analysis of Two PLA2G2A Variants Associated with Secretory Phospholipase A2-IIA Levels

    PubMed Central

    Exeter, Holly J.; Folkersen, Lasse; Palmen, Jutta; Franco-Cereceda, Anders; Cooper, Jackie A.; Kalea, Anastasia Z.; Hooft, Ferdinand van’t; Eriksson, Per; Humphries, Steve E.; Talmud, Philippa J.

    2012-01-01

    Background Secretory phospholipase A2 group IIA (sPLA2-IIA) has been identified as a biomarker of atherosclerosis in observational and animal studies. The protein is encoded by the PLA2G2A gene and the aim of this study was to test the functionality of two PLA2G2A non-coding SNPs, rs11573156 C>G and rs3767221 T>G where the rare alleles have been previously associated with higher and lower sPLA2-IIA levels respectively. Methodology/Principal Findings Luciferase assays, electrophoretic mobility shift assays (EMSA), and RNA expression by RT-PCR were used to examine allelic differences. For rs3767221 the G allele showed ∼55% lower luciferase activity compared to the T allele (T = 62.1 (95% CI 59.1 to 65.1) G = 27.8 (95% CI 25.0 to 30.6), p = 1.22×10−35, and stronger EMSA binding of a nuclear protein compared to the T-allele. For rs11573156 C >G there were no luciferase or EMSA allelic differences seen. In lymphocyte cell RNA, from individuals of known rs11573156 genotype, there was no allelic RNA expression difference for exons 5 and 6, but G allele carriers (n = 7) showed a trend to lower exon 1–2 expression compared to CC individuals. To take this further, in the ASAP study (n = 223), an rs11573156 proxy (r2 = 0.91) showed ∼25% higher liver expression of PLA2G2A (1.67×10−17) associated with the G allele. However, considering exon specific expression, the association was greatly reduced for exon 2 (4.5×10−5) compared to exons 3–6 (10−10 to 10−20), suggesting rs11573156 G allele-specific exon 2 skipping. Conclusion Both SNPs are functional and provide useful tools for Mendelian Randomisation to determine whether the relationship between sPLA2-IIA and coronary heart disease is causal. PMID:22879865

  19. Thermal Barrier Coatings

    NASA Technical Reports Server (NTRS)

    1993-01-01

    In order to reduce heat transfer between a hot gas heat source and a metallic engine component, a thermal insulating layer of material is placed between them. This thermal barrier coating is applied by plasma spray processing the thin films. The coating has been successfully employed in aerospace applications for many years. Lewis Research Center, a leader in the development engine components coating technology, has assisted Caterpillar, Inc. in applying ceramic thermal barrier coatings on engines. Because these large engines use heavy fuels containing vanadium, engine valve life is sharply decreased. The barrier coating controls temperatures, extends valve life and reduces operating cost. Additional applications are currently under development.

  20. Aircraft surface coatings

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Liquid, spray on elastomeric polyurethanes are selected and investigated as best candidates for aircraft external protective coatings. Flight tests are conducted to measure drag effects of these coatings compared to paints and a bare metal surface. The durability of two elastometric polyurethanes are assessed in airline flight service evaluations. Laboratory tests are performed to determine corrosion protection properties, compatibility with aircraft thermal anti-icing systems, the effect of coating thickness on erosion durability, and the erosion characteristics of composite leading edges-bare and coated. A cost and benefits assessment is made to determine the economic value of various coating configurations to the airlines.

  1. Coating Life Prediction

    NASA Technical Reports Server (NTRS)

    Nesbitt, J. A.; Gedwill, M. A.

    1984-01-01

    Hot-section gas-turbine components typically require some form of coating for oxidation and corrosion protection. Efficient use of coatings requires reliable and accurate predictions of the protective life of the coating. Currently engine inspections and component replacements are often made on a conservative basis. As a result, there is a constant need to improve and develop the life-prediction capability of metallic coatings for use in various service environments. The purpose of this present work is aimed at developing of an improved methodology for predicting metallic coating lives in an oxidizing environment and in a corrosive environment.

  2. Antibacterial polymer coatings.

    SciTech Connect

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  3. Coatings For Plastic Optics

    NASA Astrophysics Data System (ADS)

    Schaffer, Robert W.

    1983-11-01

    Over the past decade there has been a tremendous surge of interest in the use of plastic optical elements to supplement or replace glass optics. While the technology of molding and polishing plastic optics has been the chief interest, there has been increasing need for precision coatings for these elements. In some instances these coatings are as critical as the elements themselves. In this paper we will describe the difficulties incurred in coating plastic and some of the many coatings presently available today despite the difficulties encountered. We will then cover the durability aspects of these coatings and lastly, point out some areas to consider when evaluating using plastic instead of glass.

  4. Lubricant Coating Process

    NASA Technical Reports Server (NTRS)

    1989-01-01

    "Peen Plating," a NASA developed process for applying molybdenum disulfide, is the key element of Techniblast Co.'s SURFGUARD process for applying high strength solid lubricants. The process requires two machines -- one for cleaning and one for coating. The cleaning step allows the coating to be bonded directly to the substrate to provide a better "anchor." The coating machine applies a half a micron thick coating. Then, a blast gun, using various pressures to vary peening intensities for different applications, fires high velocity "media" -- peening hammers -- ranging from plastic pellets to steel shot. Techniblast was assisted by Rural Enterprises, Inc. Coating service can be performed at either Techniblast's or a customer's facility.

  5. Coatings for directional eutectics

    NASA Technical Reports Server (NTRS)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Significant advances have been made in the development of an environmentally stable coating for a very high strength, directionally solidified eutectic alloy designated NiTaC-13. Three duplex (two-layer) coatings survived 3,000 hours on a cyclic oxidation test (1,100 C to 90 C). These coatings were fabricated by first depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam heated source, followed by depositing an aluminizing overlayer. The alloy after exposure with these coatings was denuded of carbide fibers at the substrate/coating interface. It was demonstrated that TaC fiber denudation can be greatly retarded by applying a carbon-bearing coating. The coating was applied by thermal spraying followed by aluminization. Specimens coated with NiCrAlCY+Al survived over 2,000 hours in the cyclic oxidation test with essentially no TaC denudation. Coating ductility was studied for coated and heat-treated bars, and stress rupture life at 871 C and 1,100 C was determined for coated and cycled bars.

  6. Bacillus subtilis Spore Coat

    PubMed Central

    Driks, Adam

    1999-01-01

    In response to starvation, bacilli and clostridia undergo a specialized program of development that results in the production of a highly resistant dormant cell type known as the spore. A proteinacious shell, called the coat, encases the spore and plays a major role in spore survival. The coat is composed of over 25 polypeptide species, organized into several morphologically distinct layers. The mechanisms that guide coat assembly have been largely unknown until recently. We now know that proper formation of the coat relies on the genetic program that guides the synthesis of spore components during development as well as on morphogenetic proteins dedicated to coat assembly. Over 20 structural and morphogenetic genes have been cloned. In this review, we consider the contributions of the known coat and morphogenetic proteins to coat function and assembly. We present a model that describes how morphogenetic proteins direct coat assembly to the specific subcellular site of the nascent spore surface and how they establish the coat layers. We also discuss the importance of posttranslational processing of coat proteins in coat morphogenesis. Finally, we review some of the major outstanding questions in the field. PMID:10066829

  7. Effects of V2G Reactive Power Compensation on the Component Selection in an EV or PHEV Bidirectional Charger

    SciTech Connect

    Kisacikoglu, Mithat C; Ozpineci, Burak; Tolbert, Leon M

    2010-01-01

    Electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) are becoming a part of the electric grid day by day. Chargers for these vehicles have the ability to make this interaction better for the consumer and for the grid. Vehicle to grid (V2G) power transfer has been under research for more than a decade because of the large energy reserve of an electric vehicle battery and the potential of thousands of these connected to the grid. Rather than discharging the vehicle batteries, reactive power compensation in particular is beneficial for both consumers and for the utility. However, certain adverse effects or requirements of reactive power transfer should be defined before a design stage. To understand the dynamics of this operation, this study investigates the effect of reactive power transfer on the charger system components, especially on the dc-link capacitor and the battery.

  8. Dopaminergic neurons differentiating from LRRK2 G2019S induced pluripotent stem cells show early neuritic branching defects.

    PubMed

    Borgs, Laurence; Peyre, Elise; Alix, Philippe; Hanon, Kevin; Grobarczyk, Benjamin; Godin, Juliette D; Purnelle, Audrey; Krusy, Nathalie; Maquet, Pierre; Lefebvre, Philippe; Seutin, Vincent; Malgrange, Brigitte; Nguyen, Laurent

    2016-01-01

    Some mutations of the LRRK2 gene underlie autosomal dominant form of Parkinson's disease (PD). The G2019S is a common mutation that accounts for about 2% of PD cases. To understand the pathophysiology of this mutation and its possible developmental implications, we developed an in vitro assay to model PD with human induced pluripotent stem cells (hiPSCs) reprogrammed from skin fibroblasts of PD patients suffering from the LRKK2 G2019S mutation. We differentiated the hiPSCs into neural stem cells (NSCs) and further into dopaminergic neurons. Here we show that NSCs bearing the mutation tend to differentiate less efficiently into dopaminergic neurons and that the latter exhibit significant branching defects as compared to their controls. PMID:27640816

  9. Dopaminergic neurons differentiating from LRRK2 G2019S induced pluripotent stem cells show early neuritic branching defects

    PubMed Central

    Borgs, Laurence; Peyre, Elise; Alix, Philippe; Hanon, Kevin; Grobarczyk, Benjamin; Godin, Juliette D.; Purnelle, Audrey; Krusy, Nathalie; Maquet, Pierre; Lefebvre, Philippe; Seutin, Vincent; Malgrange, Brigitte; Nguyen, Laurent

    2016-01-01

    Some mutations of the LRRK2 gene underlie autosomal dominant form of Parkinson’s disease (PD). The G2019S is a common mutation that accounts for about 2% of PD cases. To understand the pathophysiology of this mutation and its possible developmental implications, we developed an in vitro assay to model PD with human induced pluripotent stem cells (hiPSCs) reprogrammed from skin fibroblasts of PD patients suffering from the LRKK2 G2019S mutation. We differentiated the hiPSCs into neural stem cells (NSCs) and further into dopaminergic neurons. Here we show that NSCs bearing the mutation tend to differentiate less efficiently into dopaminergic neurons and that the latter exhibit significant branching defects as compared to their controls. PMID:27640816

  10. Coated Aerogel Beads

    NASA Technical Reports Server (NTRS)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  11. Liposomes physically coated with peptides: preparation and characterization.

    PubMed

    Su, Cuicui; Xia, Yuqiong; Sun, Jianbo; Wang, Nan; Zhu, Lin; Chen, Tao; Huang, Yanyi; Liang, Dehai

    2014-06-01

    Physically coating liposomes with peptides of desirable functions is an economic, versatile, and less time-consuming approach to prepare drug delivery vehicles. In this work, we designed three peptides-Ac-WWKKKGGNNN-NH2 (W2K3), Ac-WWRRRGGNNN-NH2(W2R3), Ac-WWGGGGGNNN-NH2(W2G3)-and studied their coating ability on negatively charged liposomes. It was found that the coating was mainly driven by the electrostatic interaction between the peptides' cationic side groups and the acidic lipids, which also mediated the "anchoring " of Trp residuals in the interfacial region of lipid bilayers. At the same conditions, the amount of the coated W2R3 was more than that of W2K3, but the stability of the liposome coated with W2R3 was deteriorated. This was caused by the delocalized charge of the guanidinium group of arginine. The coating of the peptide rendered the liposome pH-responsive behavior but did not prominently change the phase transition temperature. The liposome coated with peptides displayed appropriate pH/temperature dual responsive characteristics and was able to release the content in a controlled manner.

  12. Liposomes physically coated with peptides: preparation and characterization.

    PubMed

    Su, Cuicui; Xia, Yuqiong; Sun, Jianbo; Wang, Nan; Zhu, Lin; Chen, Tao; Huang, Yanyi; Liang, Dehai

    2014-06-01

    Physically coating liposomes with peptides of desirable functions is an economic, versatile, and less time-consuming approach to prepare drug delivery vehicles. In this work, we designed three peptides-Ac-WWKKKGGNNN-NH2 (W2K3), Ac-WWRRRGGNNN-NH2(W2R3), Ac-WWGGGGGNNN-NH2(W2G3)-and studied their coating ability on negatively charged liposomes. It was found that the coating was mainly driven by the electrostatic interaction between the peptides' cationic side groups and the acidic lipids, which also mediated the "anchoring " of Trp residuals in the interfacial region of lipid bilayers. At the same conditions, the amount of the coated W2R3 was more than that of W2K3, but the stability of the liposome coated with W2R3 was deteriorated. This was caused by the delocalized charge of the guanidinium group of arginine. The coating of the peptide rendered the liposome pH-responsive behavior but did not prominently change the phase transition temperature. The liposome coated with peptides displayed appropriate pH/temperature dual responsive characteristics and was able to release the content in a controlled manner. PMID:24826785

  13. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    SciTech Connect

    Hampikian, J.M.; Carter, W.B.

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  14. Comparison of density functionals for energy and structural differences between the high- [5T2g:(t2g)4(eg)2] and low- [1A1g:(t2g)6(eg)0] spin states of iron(II) coordination compounds. II. More functionals and the hexaminoferrous cation, [Fe(NH3)6]2+

    NASA Astrophysics Data System (ADS)

    Fouqueau, Antony; Casida, Mark E.; Daku, Latévi Max Lawson; Hauser, Andreas; Neese, Frank

    2005-01-01

    The ability of different density functionals to describe the structural and energy differences between the high- [5T2g:(t2g)4(eg)2] and low- [1A1g:(t2g)6(eg)0] spin states of small octahedral ferrous compounds is studied. This work is an extension of our previous study of the hexaquoferrous cation, [Fe(H2O)6]2+, [J. Chem. Phys. 120, 9473 (2004)] to include a second compound—namely, the hexaminoferrous cation, [Fe(NH3)6]2+—and several additional functionals. In particular, the present study includes the highly parametrized generalized gradient approximations (GGAs) known as HCTH and the meta-GGA VSXC [which together we refer to as highly parametrized density functionals (HPDFs)], now readily available in the GAUSSIAN03 program, as well as the hybrid functional PBE0. Since there are very few experimental results for these molecules with which to compare, comparison is made with best estimates obtained from second-order perturbation theory-corrected complete active space self-consistent field (CASPT2) calculations, with spectroscopy oriented configuration interaction (SORCI) calculations, and with ligand field theory (LFT) estimations. While CASPT2 and SORCI are among the most reliable ab initio methods available for this type of problem, LFT embodies many decades of empirical experience. These three methods are found to give coherent results and provide best estimates of the adiabatic low-spin-high-spin energy difference, ΔELHadia, of 12 000-13 000 cm-1 for [Fe(H2O)6]2+ and 9 000-11 000 cm-1 for [Fe(NH3)6]2+. All functionals beyond the purely local approximation produce reasonably good geometries, so long as adequate basis sets are used. In contrast, the energy splitting, ΔELHadia, is much more sensitive to the choice of functional. The local density approximation severely over stabilizes the low-spin state with respect to the high-spin state. This "density functional theory (DFT) spin pairing-energy problem" persists, but is reduced, for traditional GGAs. In

  15. Comparison of density functionals for energy and structural differences between the high- [5T2g: (t2g)4(eg)2] and low- [1A1g: (t2g)6(eg)0] spin states of the hexaquoferrous cation [Fe(H2O)6]2+

    NASA Astrophysics Data System (ADS)

    Fouqueau, Antony; Mer, Sébastien; Casida, Mark E.; Lawson Daku, Latevi Max; Hauser, Andreas; Mineva, Tsonka; Neese, Frank

    2004-05-01

    A comparison of density functionals is made for the calculation of energy and geometry differences for the high- [5T2g:(t2g)4(eg)2] and low- [1A1g: (t2g)6(eg)0] spin states of the hexaquoferrous cation [Fe(H2O)6]2+. Since very little experimental results are available (except for crystal structures involving the cation in its high-spin state), the primary comparison is with our own complete active-space self-consistent field (CASSCF), second-order perturbation theory-corrected complete active-space self-consistent field (CASPT2), and spectroscopy-oriented configuration interaction (SORCI) calculations. We find that generalized gradient approximations (GGAs) and the B3LYP hybrid functional provide geometries in good agreement with experiment and with our CASSCF calculations provided sufficiently extended basis sets are used (i.e., polarization functions on the iron and polarization and diffuse functions on the water molecules). In contrast, CASPT2 calculations of the low-spin-high-spin energy difference ΔELH=ELS-EHS appear to be significantly overestimated due to basis set limitations in the sense that the energy difference of the atomic asymptotes (5D→1I excitation of Fe2+) are overestimated by about 3000 cm-1. An empirical shift of the molecular ΔELH based upon atomic calculations provides a best estimate of 12 000-13 000 cm-1. Our unshifted SORCI result is 13 300 cm-1, consistent with previous comparisons between SORCI and experimental excitation energies which suggest that no such empirical shift is needed in conjunction with this method. In contrast, after estimation of incomplete basis set effects, GGAs with one exception underestimate this value by 3000-4000 cm-1 while the B3LYP functional underestimates it by only about 1000 cm-1. The exception is the GGA functional RPBE which appears to perform as well as or better than the B3LYP functional for the properties studied here. In order to obtain a best estimate of the molecular ΔELH within the context of

  16. A peptide inhibitor of HIV-1 neutralizing antibody 2G12 is not a structural mimic of the natural carbohydrate epitope on gp120

    PubMed Central

    Menendez, Alfredo; Calarese, Daniel A.; Stanfield, Robyn L.; Chow, Keith C.; Scanlan, Chris N.; Kunert, Renate; Katinger, Herman; Burton, Dennis R.; Wilson, Ian A.; Scott, Jamie K.

    2008-01-01

    MAb 2G12 neutralizes HIV-1 by binding with high affinity to a cluster of high-mannose oligosaccharides on the envelope glycoprotein, gp120. Screening of phage-displayed peptide libraries with 2G12 identified peptides that bind specifically, with Kds ranging from 0.4 to 200 μM. The crystal structure of a 21-mer peptide ligand in complex with 2G12 Fab was determined at 2.8 Å resolution. Comparison of this structure with previous structures of 2G12-carbohydrate complexes revealed striking differences in the mechanism of 2G12 binding to peptide vs. carbohydrate. The peptide occupies a site different from, but adjacent to, the primary carbohydrate-binding site on 2G12, and makes only slightly fewer contacts to the Fab than Man9GlcNAc2 (51 vs. 56, respectively). However, only two antibody contacts with the peptide are hydrogen bonds in contrast to six with Man9GlcNAc2, and only three of the antibody residues that interact with Man9GlcNAc2 also contact the peptide. Thus, this mechanism of peptide binding to 2G12 does not support structural mimicry of the native carbohydrate epitope on gp120, since it neither replicates the oligosaccharide footprint on the antibody nor most of the contact residues. Moreover, 2G12.1 peptide is not an immunogenic mimic of the 2G12 epitope, since antisera produced against it did not bind gp120.—Menendez, A., Calarese, D. A., Stanfield, R. L., Chow, K. C., Scanlan, C. N., Kunert, R., Katinger, H., Burton, D. R., Wilson, I. A., Scott, J. K. A peptide inhibitor of HIV-1 neutralizing antibody 2G12 is not a structural mimic of the natural carbohydrate epitope on gp120. PMID:18198210

  17. Tailored coatings for hardfacing

    SciTech Connect

    Dustoor, M.R.; Moskowitz, L.N.

    1984-01-01

    An update on Conforma Clad coatings, first presented at the 1982 National Powder Metallurgy Conference in Montreal, Canada, is presented. The major advantage is the ability to offer selective-area coatings in a wide range of thicknesses and material choices while retaining dimensional and edge control of the coating. Complex geometries can be coated with a high materials utilization and with coating properties tailored to the end application. Porosity and bond strength values can match or exceed those seen with the best commercially available thermal sprayed coatings. The ability of the process to balance abrasion resistance and toughness requirements for a specific wear mode, is illustrated by microstructural control of the size, shape and density of carbide particles contained in the coatings. Dry sand abrasive test data are provided on Conforma Clad coatings and competitive processes. Ongoing developments of non-furnace fusion techniques, such as laser cladding, are presented and the microstructures compared with those obtained with conventional coating processes. Commercial applications for these coatings are highlighted with some typical examples.

  18. NX-2G : autonomous BBOBS-NX for a highly mobile broadband seismic observation at the seafloor

    NASA Astrophysics Data System (ADS)

    Shiobara, Hajime; Sugioka, Hiroko; Ito, Aki; Shinohara, Masanao

    2016-04-01

    We had developed the broadband ocean bottom seismometer (BBOBS) and its new generation system (BBOBS-NX), and, with them, several practical observations have been performed to create and establish a new category of the ocean floor broadband seismology, since 1999. Now, our BBOBS and BBOBS-NX data is proved to be at acceptable level for broadband seismic analyses. Especially, the BBOBS-NX is able to obtain the low noise horizontal data comparable to the land station in periods longer than 10 s, which is adequate for modern analyses of the mantle structure. Moreover, the BBOBS(T)-NX is under practical evaluation for the mobile tilt observation at the seafloor, which will enable dense geodetic monitoring. The BBOBS-NX system must be a powerful tool, although, the current system has intrinsic limitation in opportunity of observations due to the necessary use of the submersible vehicle for the deployment and recovery. If we can use this system with almost any kind of vessels, like as the BBOBS (self pop-up system), it should lead us a true breakthrough of seafloor observations in geodynamics. Hereafter, we call the new autonomous BBOBS-NX as NX-2G in short. There are two main problems to be cleared to realize the NX-2G system. The first one is a tilt of the sensor unit on landing, which is larger than the acceptable limit of the sensor (±8°) in 47 % after our 15 free-fall deployments of the BBOBS-NX. As we had no evidence at which moment the tilt occurred, so it was observed during the BBOBS-NX deployment in the last year by attaching a video camera and an acceleration logger those were originally developed for this purpose. The only one result shows that the tilt on landing seemed determined by the final posture of the BBOBS-NX system just before the penetration into the sediment. The second problem is a required force to extract the sensor unit from the sticky clay sediment, which was about 80 kgf in maximum with the current BBOBS-NX system from in-situ measurements

  19. Coatings for graphite fibers

    NASA Technical Reports Server (NTRS)

    Galasso, F. S.; Scola, D. A.; Veltri, R. D.

    1980-01-01

    Graphite fibers released from composites during burning or an explosion caused shorting of electrical and electronic equipment. Silicon carbide, silica, silicon nitride and boron nitride were coated on graphite fibers to increase their electrical resistances. Resistances as high as three orders of magnitude higher than uncoated fiber were attained without any significant degradation of the substrate fiber. An organo-silicone approach to produce coated fibers with high electrical resistance was also used. Celion 6000 graphite fibers were coated with an organo-silicone compound, followed by hydrolysis and pyrolysis of the coating to a silica-like material. The shear and flexural strengths of composites made from high electrically resistant fibers were considerably lower than the shear and flexural strengths of composites made from the lower electrically resistant fibers. The lower shear strengths of the composites indicated that the coatings on these fibers were weaker than the coating on the fibers which were pyrolyzed at higher temperature.

  20. Fabrication of highly textured Ni-7at.%W substrates and further application for coated La 2Zr 2O 7 buffer layer

    NASA Astrophysics Data System (ADS)

    Cheng, Y. L.; Suo, H. L.; Zhao, Y.; Gao, M. M.; Zhu, Y. H.; Wang, R.; Liu, M.; Ma, L.; Zhou, M. L.

    2011-11-01

    In this work, highly cube textured Ni-7at.%W (Ni7W) substrate was fabricated from the ingots synthesized by Spark Plasma Sintering (SPS) technique. Both the La 2Zr 2O 7 (LZO) buffer layer and the YBCO superconducting layer were coated using chemical solution deposition (CSD) and pulsed laser deposition (PLD) layer by layer. The full-width-at-half-maximum (FWHM) values of the (1 1 1) phi-scan and the (2 0 0) ω-scan in rolling direction of the Ni7W substrate were 6.30° and 5.08°, respectively. The EBSD analyses indicated that the percentage of the cube texture component on the surface of the as-obtained Ni7W substrate was 99.4% within a tolerance angle of less than 10°. Highly epitaxial growth of homogenous crack-free LZO film was obtained cube-on-cube relative to the Ni7W substrate, with FWHM values of (2 2 2) phi-scan and (4 0 0) ω-scan of 7.57° and 5.73°, respectively. The critical temperature of the YBCO layer prepared on LZO/Ni7 W substrate is about 90.5 K, while the critical current density is 1.25 MA cm -2 (77 K, sf).

  1. Optical coating in space

    NASA Technical Reports Server (NTRS)

    Bunner, A. N.

    1983-01-01

    A technological appraisal of the steps required to approach the goal of in-situ optical coating, cleaning and re-coating the optical elements of a remote telescope in space is reported. Emphasis is placed on the high ultraviolet throughput that a telescope using bare aluminum mirrors would offer. A preliminary design is suggested for an Orbital Coating Laboratory to answer basic technical questions.

  2. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2004-08-31

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  3. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2003-10-14

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  4. Thermally sprayed coatings

    SciTech Connect

    Diaz, D.J.; Blann, G.A. )

    1991-05-01

    Standardization of specimen preparation for microstructural evaluation of thermally sprayed coatings is considered. Metallographic specimen preparation procedures including sectioning, encapsulation, planar grinding, and power lapping of thermally sprayed coatings are described. A Co-Ni-Cr-W coating on an AISI 410 stainless steel substrate is used as a control sample. Specimen-preparation techniques have been evaluated through scanning electron microscopy for determining the percentage of apparent porosity and energy dispersive spectroscopy for determining elemental composition.

  5. Glutathione S-transferase P1, a novel downstream regulator of LRRK2 (G2019S)-induced cytotoxicity in neural cells

    PubMed Central

    Chen, Jie; Liou, Anthony; Zhang, Lili; Weng, Zhongfang; Gao, Yanqin; Cao, Guodong; Zigmond, Michael J.; Chen, Jun

    2014-01-01

    The enhanced neurotoxicity of the Parkinson’s disease-associated LRRK2 mutant, G2019S, than its wild-type counter-part has recently been reported. Overexpression of LRRK2 (G2019S) in cultured neural cells results in caspase-3-dependent apoptosis via a yet undefined signaling pathway. Elucidation of the mechanism underlying LRRK2 (G2019S) neurotoxicity may offer new insights into the pathogenesis of Parkinson’s disease. In this study, utilizing two-dimensional gel electrophoresis coupled with mass spectrometry, we have identified glutathione s-transferase P1 (GSTP1) as a selective target whose expression is negatively regulated at the transcriptional levels by LRRK2 (G2019S). Overexpression of LRRK2 (G2019S) in the human neuronal cell line SH-SY5Y markedly suppressed the expression of GSTP1 prior to any manifestation of cell death. This suppression of GSTP1 expression was due to LRRK2 (G2019S) – elicited production of peroxides and subsequent hyper-methylation on the promoter of GSTP1. Moreover, shRNA-mediated knockdown of endogenous GSTP1 expression exacerbated LRRK2 (G2019S) neurotoxicity, whereas overexpression of GSTP1 protected against LRRK2 (G2019S)-induced caspase-3 activation and neuronal apoptosis. In conclusion, the results suggest a previously undefined signaling mechanism underlying the neurotoxic effect of LRRK2 (G2019S), in which LRRK2 (G2019S) triggers oxidative stress in cells and, in turn, results in caspase-dependent apoptosis at least in part by suppressing the expression of GSTP1. PMID:22652643

  6. AC loss of a model 5m 2G HTS power cable using wires with NiW substrates

    NASA Astrophysics Data System (ADS)

    Vysotsky, V. S.; Shutov, K. A.; Nosov, A. A.; Polyakova, N. V.; Fetisov, S. S.; Zubko, V. V.; Sytnikov, V. E.; Carter, W. L.; Fleshler, S.; Malozemoff, A. P.; Snitchler, G.

    2010-06-01

    A model 5 m cable prototype was constructed using American Superconductor second generation (2G) high temperature superconductor (HTS) wires - 344 superconductors, produced with the MOD/RABiTSTM process. The model cable consists of two helically counterwound layers of brass-laminated tapes. Twist pitches were calculated to provide uniform current distribution between the two cable layers. The NiW substrates of the tapes were oriented to face radially inward and radially outward for the inner and outer layers of the cable, respectively, to minimize the spacing between the HTS layers and any effects of the weak substrate magnetism. To verify the calculations and design principles, the model cable was instrumented with potential taps and sensors, including Rogowski coils and Hall probes, to measure the current distribution among layers, voltage - current characteristics and other parameters. AC losses in this cable model have been measured and analyzed by use of digital measurements of current and voltage. At low to intermediate currents, they are in the range of a few tenths of a watt per meter, consistent with the ferromagnetic loss of the substrate. Analysis of the individual contributions of the Ni-W substrate and the superconductor hysteresis loss is given.

  7. TiO2/g-C3N4 heterojunctions: In situ fabrication mechanism and enhanced photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Wu, Li-Cheng; Zhao, Hang; Jin, Li-Guo; Xu, Huan-Yan

    2016-09-01

    In situ fabrication of TiO2/g-C3N4 (TCN) heterojunctions was achieved by a modified sol-gel method. TG analysis was employed to determine the content of TiO2 in TCN composites. XRD, FTIR, TEM and HRTEM were used to analyze the phase composition, functional groups, morphology and microstructure of as-obtained products, respectively. Based on the measurement of surface Zeta potential of g-C3N4, a possible mechanism on in situ fabrication of TCN heterojunctions was concluded. The control experiments indicated that TCN heterojunctions exhibited better photocatalytic performance than either TiO2 or g-C3N4, suggesting that the enchanced photocatalytic activity could be realized by TCN heterojunctions. Then, the evaluation of parameters affecting the photocatalytic performance of TCN heterojunctions was investigated. Even after five cycles, TCN heterojunctions still maintained high photocatalytic activity, exhibiting the good photocatalytic stability. UV-vis absorption spectra showed that almost all MB molecules were decomposed in the photocatalytic process. Finally, the possible mechanism on enhanced photocatalytic performance of TCN heterojunctions was discussed.

  8. Aircraft surface coatings

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A series of studies in which films and liquid spray-on materials were evaluated in the laboratory for transport aircraft external surface coatings are summarized. Elastomeric polyurethanes were found to best meet requirements. Two commercially available products, CAAPCO B-274 and Chemglaze M313, were subjected to further laboratory testing, airline service evaluations, and drag-measurement flight tests. It was found that these coatings were compatible with the severe operating environment of airlines and that coatings reduced airplane drag. An economic analysis indicated significant dollar benefits to airlines from application of the coatings.

  9. Oxide coating development

    SciTech Connect

    Stinton, D.P.

    1995-06-01

    Monolithic SiC heat exchangers and fiber-reinforced SiC-matrix composite heat exchangers and filters are susceptible to corrosion by alkali metals at elevated temperatures. Protective coatings are currently being developed to isolate the SiC materials from the corrodants. Unfortunately, these coatings typically crack and spall when applied to SiC substrates. The purpose of this task is to determine the feasibility of using a compliant material between the protective coating and the substrate. The low-modulus compliant layer could absorb stresses and eliminate cracking and spalling of the protective coatings.

  10. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  11. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  12. Coatings for Graphite Fibers

    NASA Technical Reports Server (NTRS)

    Galasso, F. S.; Scola, D. A.; Veltri, R. D.

    1980-01-01

    Several approaches for applying high resistance coatings continuously to graphite yarn were investigated. Two of the most promising approaches involved (1) chemically vapor depositing (CVD) SiC coatings on the surface of the fiber followed by oxidation, and (2) drawing the graphite yarn through an organo-silicone solution followed by heat treatments. In both methods, coated fibers were obtained which exhibited increased electrical resistances over untreated fibers and which were not degraded. This work was conducted in a previous program. In this program, the continuous CVD SiC coating process used on HTS fiber was extended to the coating of HMS, Celion 6000, Celion 12000 and T-300 graphite fiber. Electrical resistances three order of magnitude greater than the uncoated fiber were measured with no significant degradation of the fiber strength. Graphite fibers coated with CVD Si3N4 and BN had resistances greater than 10(exp 6) ohm/cm. Lower pyrolysis temperatures were used in preparing the silica-like coatings also resulting in resistances as high as three orders of magnitude higher than the uncoated fiber. The epoxy matrix composites prepared using these coated fibers had low shear strengths indicating that the coatings were weak.

  13. Combustion chemical vapor deposited coatings for thermal barrier coating systems

    SciTech Connect

    Hampikian, J.M.; Carter, W.B.

    1995-12-31

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.

  14. SO/sub 2/(g)-to-sulfate conversion rate in an oil-fired-power-plant plume in a fog bank

    SciTech Connect

    Eatough, D.J.; Arthur, R.J.; Eatough, N.L.; Hill, M.W.; Mangelson, N.F.; Richter, B.E.; Hansen, L.D.; Cooper, J.A.

    1983-01-01

    High acidity in rainfall, cloud droplets and fog droplets in areas influenced by anthropogenic sources of SO/sub 2/(g) and NO/sub x/(g) has been attributed to the formation of both H/sub 2/SO/sub 4/ and HNO/sub 3/. It has been suggested, based on the analysis of field data, that rapid conversion of SO/sub 2/(g) to sulfate must occur in cloud or fog droplets. Direct measurements of the rate of SO/sub 2/(g) to sulfate conversion in an oil-fired power plant plume as it passes through a fog bank are reported here. A conversion rate of 30+-4% SO/sub 2/(g) h/sup -1/ was found in the fog bank.

  15. New analytical techniques for mycotoxins in complex organic matrices. [Aflatoxins B1, B2, G1, and G2

    SciTech Connect

    Bicking, M.K.L.

    1982-07-01

    Air samples are collected for analysis from the Ames Solid Waste Recovery System. The high level of airborne fungi within the processing area is of concern due to the possible presence of toxic mycotoxins, and carcinogenic fungal metabolites. An analytical method has been developed to determine the concentration of aflatoxins B1, B2, G1, and G2 in the air of the plant which produces Refuse Derived Fuel (RDF). After extraction with methanol, some components in the matrix are precipitated by dissolving the sample in 30% acetonitrile/chloroform. An aliquot of this solution is injected onto a Styragel column where the sample components undergo simultaneous size exclusion and reverse phase partitioning. Additional studies have provided a more thorough understanding of solvent related non-exclusion effects on size exclusion gels. The Styragel column appears to have a useable lifetime of more than six months. After elution from Styragel, the sample is diverted to a second column containing Florisil which has been modified with oxalic acid and deactivated with water. Aflatoxins are eluted with 5% water/acetone. After removal of this solvent, the sample is dissolved in 150 ..mu..L of a spotting solvent and the entire sample applied to a thin layer chromatography (TLC) plate using a unique sample applicator developed here. The aflatoxins on the TLC plate are analyzed by laser fluorescence. A detection limit of 10 pg is possible for aflatoxin standards using a nitrogen laser as the excitation source. Sample concentrations are determined by comparing with an internal standard, a specially synthesized aflatoxin derivative. In two separate RDF samples, aflatoxin B1 was found at levels of 6.5 and 17.0 ppB. The analytical method has also proven useful in the analysis of contaminated corn and peanut meal samples. 42 figures, 8 tables.

  16. Determination of aflatoxins B1, B2, G1, and G2 in olive oil, peanut oil, and sesame oil.

    PubMed

    Bao, Lei; Trucksess, Mary W; White, Kevin D

    2010-01-01

    Edible oils are consumed directly, and used as ingredients in food, soaps, and skin products. However, oils such as olive oil, peanut oil, and sesame oil could be contaminated with aflatoxins, which are detrimental to human and animal health. A method using immunoaffinity column cleanup with RPLC separation and fluorescence detection (FLD) for determination of aflatoxins (AF) B1, B2, G1, and G2 in olive oil, peanut oil, and sesame oil was developed and validated. Test samples were extracted with methanol-water (55 + 45, v/v). After shaking and centrifuging, the lower layer was filtered, diluted with water, and filtered through glass microfiber filter paper. The filtrate was then passed through an immunoaffinity column, and the toxins were eluted with methanol. The toxins were then subjected to RPLC/FLD analysis after postcolumn UV photochemical derivatization. The accuracy and repeatability characteristics of the method were determined. Recoveries of AFB1 spiked at levels from 1.0 to 10.0 microg/kg in olive oil, peanut oil, and sesame oil ranged from 82.9 to 98.6%. RSDs ranged from 0.6 to 8.9%. HorRat values were < 0.2 for all of the matrixes tested. Recoveries of AF spiked at levels from 2.0 to 20.0 microg/kg ranged from 87.7 to 102.2%. RSDs ranged from 1.3 to 12.6%. HorRat values were < 0.4 for all of the matrixes tested. LC/MS/MS with multiple-reaction monitoring was used to confirm the identities of aflatoxins in a naturally contaminated peanut oil.

  17. The phzA2-G2 Transcript Exhibits Direct RsmA-Mediated Activation in Pseudomonas aeruginosa M18

    PubMed Central

    Ren, Bin; Shen, Huifeng; Lu, Zhi John; Liu, Haiming; Xu, Yuquan

    2014-01-01

    In bacteria, RNA-binding proteins of the RsmA/CsrA family act as post-transcriptional regulators that modulate translation initiation at target transcripts. The Pseudomonas aeruginosa genome contains two phenazine biosynthetic (phz) gene clusters, phzA1-G1 (phz1) and phzA2-G2 (phz2), each of which is responsible for phenazine-1-carboxylic acid (PCA) biosynthesis. In the present study, we show that RsmA exhibits differential gene regulation on two phz clusters in P. aeruginosa M18 at the post-transcriptional level. Based on the sequence analysis, four GGA motifs, the potential RsmA binding sites, are found on the 5′-untranslated region (UTR) of the phz2 transcript. Studies with a series of lacZ reporter fusions, and gel mobility shift assays suggest that the third GGA motif (S3), located 21 nucleotides upstream of the Shine-Dalgarno (SD) sequence, is involved in direct RsmA-mediated activation of phz2 expression. We therefore propose a novel model in which the binding of RsmA to the target S3 results in the destabilization of the stem-loop structure and the enhancement of ribosome access. This model could be fully supported by RNA structure prediction, free energy calculations, and nucleotide replacement studies. In contrast, various RsmA-mediated translation repression mechanisms have been identified in which RsmA binds near the SD sequence of target transcripts, thereby blocking ribosome access. Similarly, RsmA is shown to negatively regulate phz1 expression. Our new findings suggest that the differential regulation exerted by RsmA on the two phz clusters may confer an advantage to P. aeruginosa over other pseudomonads containing only a single phz cluster in their genomes. PMID:24586939

  18. Relationship of the Levitation Force Between Single and Multiple YBCO Bulks Above a Permanent Magnet Guideway Operating Dive-Lift Movement with Different Angles

    NASA Astrophysics Data System (ADS)

    Zeng, R.; Wang, S. Y.; Liao, X. L.; Deng, Z. G.; Wang, J. S.

    2013-04-01

    In practical applications, the acceleration and deceleration motions inevitably happen in the operation of high temperature superconducting (HTS) maglev trains. For further research of the maglev properties of YBaCuO bulk above a permanent magnet guideway (PMG), by moving a fixed vertical distance, this paper studies the relationship of the levitation force between single and multiple YBCO bulks above a PMG operating dive-lift movement with different angles. Experimental results show that the maximal levitation force increment of two bulks than one bulk is smaller than the maximal levitation force increment of three bulks than two bulks. With the degree decreasing, the maximal levitation force increment of three bulks is bigger than the maximal levitation force increment of two bulks and one bulk, and the hysteresis loop of the levitation force of the three-bulk arrangement is getting smaller.

  19. Facile and Cost-Effective Synthesis and Deposition of a YBCO Superconductor on Copper Substrates by High-Energy Ball Milling

    NASA Astrophysics Data System (ADS)

    Alami, Abdul Hai; Assad, Mhd Adel; Aokal, Camilia

    2016-09-01

    The article investigates the synthesis and deposition of YBCO on a copper substrate for various functional purposes. The superconductor is first prepared by mechanically alloying elemental components (yttrium, barium, and copper) for 50 hours in a high-energy ball mill with subsequent protocol of heat treatment in an oxygen-rich atmosphere to arrive at stoichiometric ratios of YBa2Cu3O7. The material is then deposited on a thin copper substrate also by ball milling under various parameters of rotational speed and deposition time to select the best and most homogenous substrate coverage. Atomic force microscopy has confirmed the desired results, and other microstructural, thermal, and electrical techniques are used to characterize the obtained material. High-energy ball milling proved to be a versatile means to synthesize and deposit the material in a straightforward manner and controllable parameters for different deposit thicknesses and coverages.

  20. Melting of SmBa2Cu3O7-y-seeds during preparation of YBCO Bulk Superconductors by Infiltration Growth Method

    NASA Astrophysics Data System (ADS)

    Vojtkova, L.; Diko, P.; Volochová, D.

    2016-03-01

    The conditions for single-grain growth of YBCO bulk superconductors by top seeded infiltration growth were tested. It is shown that the interaction of melt formed from BaCuO2 + CuO + Y2O3 precursor with the Sm123 seed causes dissolution of the seed at maximum melting temperature 1045 °C. Experiments with low weight Y211 pellet confirmed that the low concentration of Y in the infiltration melt is responsible for this effect. The most effective way suppressing the seed dissolution was shown to be the insertion of Y123 + Y211 buffer layer between the seed and the Y211 pellet. This buffer layer possesses the melt which is saturated with yttrium what prevents dissolution of the seed.

  1. Counter magnetization of SmCo5 permanent magnet by YBCO/Ag composite bulk superconductor — A competing interaction picture

    NASA Astrophysics Data System (ADS)

    Parthasarathy, R.; Lakshmi, M. M.; Seshubai, V.

    2012-06-01

    We report here for the first time the counter magnetization of an SmCo5 permanent magnet in the presence of a YBCO/Ag composite bulk superconductor. This remarkable phenomenon has been observed during our experiments to measure the levitation force of the superconductor. The inclination to study the effects of the superconductor on the permanent magnet led us to observe this surprising and curious phenomenon for the first time. A complete M-H hysteresis loop of the SmCo5 permanent magnet has been recorded using the bulk superconductor itself as a magnet. We present some of the initial results which are interesting and we discuss the possible kind of interaction that could lead to our observations.

  2. Effects of Long Term Exposure of 900-1800 MHz Radiation Emitted from 2G Mobile Phone on Mice Hippocampus- A Histomorphometric Study

    PubMed Central

    Shanmugasamy, Kathirvelu; Anbalagan, Jayaram; Rajanarayanan, Swamynathan; Meenachi, Swamynathan

    2016-01-01

    Introduction The advancement in the telecommunications technology with multi-functional added features in mobile phone, attracts more users of all age group. It is alarming to note that, the mobile phone use has increased amongst children and they are exposed to potentially harmful radiofrequency radiation in their lifetime. Aim To investigate the long term exposure of 900 to 1800 MHz radiations emitted from 2G mobile phone in mice hippocampus at histomorphometric level. Materials and Methods With due approval from institutional animal ethics committee, 36 mice were exposed to 2G mobile phone radiation, 48 minutes per day for a period of 30-180 days. The control group was kept under similar conditions without 2G exposure. Mice were sacrificed and the brain was removed from the first month to six months period. Brain was removed from the cranial cavity and hippocampus region was dissected out carefully and processed for routine histological study. Random serial sections were analysed under microscope for histomorphometric changes. For statistical analysis, independent t-test was used for comparing control and 2G exposed groups. Results The mean density of neurons in the hippocampus regions CA1, CA2 and DGDB from first to sixth month was significantly lower in the 2G exposed groups; however, in CA3 and DGVB, the 2G exposed mice showed significantly higher density of neurons. The mean nuclear diameter of neurons in the hippocampus region of CA1, CA2, CA3, DGDB and DGVB from first to sixth months showed lower nuclear diameter in 2G exposed mice. Conclusion The long term exposure to 900-1800 MHz frequency radiations emitted from 2G mobile phone could cause significantly reduced neuron density and decreased nuclear diameter in the hippocampus neurons of mice. PMID:27656427

  3. Thermal barrier coating

    DOEpatents

    Bowker, Jeffrey Charles; Sabol, Stephen M.; Goedjen, John G.

    2001-01-01

    A thermal barrier coating for hot gas path components of a combustion turbine based on a zirconia-scandia system. A layer of zirconium scandate having the hexagonal Zr.sub.3 Sc.sub.4 O.sub.12 structure is formed directly on a superalloy substrate or on a bond coat formed on the substrate.

  4. Thermal barrier coating system

    NASA Technical Reports Server (NTRS)

    Stecura, S. (Inventor)

    1985-01-01

    An oxide thermal barrier coating comprises ZrO3-Yb2O3 that is plasma sprayed onto a previously applied bond coating. The zirconia is partially stabilized with about 124 w/o ytterbia to insure cubic, monoclinic, and terragonal phases.

  5. Molecular Adsorber Coating

    NASA Technical Reports Server (NTRS)

    Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

    2011-01-01

    A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.

  6. Coated ceramic breeder materials

    DOEpatents

    Tam, Shiu-Wing; Johnson, Carl E.

    1987-04-07

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  7. Duplex aluminized coatings

    NASA Technical Reports Server (NTRS)

    Gedwill, M. A.; Grisaffe, S. J. (Inventor)

    1975-01-01

    The surface of a metallic base system is initially coated with a metallic alloy layer that is ductile and oxidation resistant. An aluminide coating is then applied to the metallic alloy layer. The chemistry of the metallic alloy layer is such that the oxidation resistance of the subsequently aluminized outermost layer is not seriously degraded.

  8. Fast-drying coating

    NASA Technical Reports Server (NTRS)

    Bartoszek, E. J.

    1978-01-01

    Nontoxic coating has excellent optical properties and can be pigmented in many different colors. It bonds well, can be applied by conventional methods, weathers well, and is self-extinguishing. Coating composition comprises latex blends of fluorocarbons, acrylic resins, stabilizers, modifiers, variety of inorganic pigments, and other additives. Suitable latex primers have also been developed from acrylic latex base.

  9. Polyphosphazene Icephobic Coating Materials

    NASA Technical Reports Server (NTRS)

    Willis, Paul B.

    1992-01-01

    Coating materials consisting mostly of modified polyphosphazene (Class FZ) elastomers provide better protection against icing than fluorocarbon polymers and silicone elastomers. Reduces adhesive force between ice and surface. As consequence, increasing weight of ice, wind loading, or vibration of surface causes ice to be shed. New icephobic coats reduce accumulation of ice on aircraft, radomes, antennas, ships, and power-transmission lines.

  10. Coated ceramic breeder materials

    DOEpatents

    Tam, Shiu-Wing; Johnson, Carl E.

    1987-01-01

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  11. High-Pressure Oxygenation of Mt-Ybco the way to Reduce the Oxygenation Time, to Prevent Macrocracking, and to Obtain Materials with High Critical Currents.

    NASA Astrophysics Data System (ADS)

    Prikhna, T. A.; Chaud, X.; Gawalek, W.; Joulain, A.; Rabier, J.; Moshchil, V. E.; Savchuk, Ya. M.; Sergienko, N. V.; Dub, S. N.; Melnikov, V. S.; Habisreuther, T.; Litzkendorf, D.; Bierlich, J.

    2008-03-01

    The oxygenation of MT-YBCO under isostatic oxygen pressure (up to 16 MPa) at 900-800 °C allowed reduced process time, lower macrocracking, and reduced microcracks. Additionally higher critical currents, trapped fields and mechanical characteristics can be attained. At 77 K thin-walled MT-YBCO had a jc in the ab plane of 85 kA/cm2 at 0 T and higher than 10 kA/cm2 in fields up to 5 T and the irreversibility field was 9.8 T. In the c-direction jc was 34 kA/cm2 in 0 T and higher than 2.5 kA/cm2 in a 10 T field. At 4.9 N-load the micohardness, Hv, was 8.7±0.3 GPa in the ab-plane and 7.6±0.3 GPa in the c-direction. The fracture toughness, K1C, was 2.5±0.1 MPaṡm0.5 (ab-plane) and 2.8±0.24 MPaṡm0.5 (c-direction). The samples with a higher twin density demonstrated a higher jc, especially in applied magnetic field. The twin density correlates with the sizes and distribution of Y211 grains in Y123. The thin-walled ceramics that demonstrated the highest jc contained about 22 twins in 1 μm and were practically free from dislocations and stacking faults. The maximal trapped field of the block of thin-walled ceramic oxygenated at 900-800 °C and 16 MPa was doubled as compared to that oxygenated at low temperature under ambient pressure.

  12. Rapid and semi-analytical design and simulation of a toroidal magnet made with YBCO and MgB2 superconductors

    DOE PAGES

    Dimitrov, I. K.; Zhang, X.; Solovyov, V. F.; Chubar, O.; Li, Qiang

    2015-07-07

    Recent advances in second-generation (YBCO) high-temperature superconducting wire could potentially enable the design of super high performance energy storage devices that combine the high energy density of chemical storage with the high power of superconducting magnetic storage. However, the high aspect ratio and the considerable filament size of these wires require the concomitant development of dedicated optimization methods that account for the critical current density in type-II superconductors. In this study, we report on the novel application and results of a CPU-efficient semianalytical computer code based on the Radia 3-D magnetostatics software package. Our algorithm is used to simulate andmore » optimize the energy density of a superconducting magnetic energy storage device model, based on design constraints, such as overall size and number of coils. The rapid performance of the code is pivoted on analytical calculations of the magnetic field based on an efficient implementation of the Biot-Savart law for a large variety of 3-D “base” geometries in the Radia package. The significantly reduced CPU time and simple data input in conjunction with the consideration of realistic input variables, such as material-specific, temperature, and magnetic-field-dependent critical current densities, have enabled the Radia-based algorithm to outperform finite-element approaches in CPU time at the same accuracy levels. Comparative simulations of MgB2 and YBCO-based devices are performed at 4.2 K, in order to ascertain the realistic efficiency of the design configurations.« less

  13. Rapid and semi-analytical design and simulation of a toroidal magnet made with YBCO and MgB2 superconductors

    SciTech Connect

    Dimitrov, I. K.; Zhang, X.; Solovyov, V. F.; Chubar, O.; Li, Qiang

    2015-07-07

    Recent advances in second-generation (YBCO) high-temperature superconducting wire could potentially enable the design of super high performance energy storage devices that combine the high energy density of chemical storage with the high power of superconducting magnetic storage. However, the high aspect ratio and the considerable filament size of these wires require the concomitant development of dedicated optimization methods that account for the critical current density in type-II superconductors. In this study, we report on the novel application and results of a CPU-efficient semianalytical computer code based on the Radia 3-D magnetostatics software package. Our algorithm is used to simulate and optimize the energy density of a superconducting magnetic energy storage device model, based on design constraints, such as overall size and number of coils. The rapid performance of the code is pivoted on analytical calculations of the magnetic field based on an efficient implementation of the Biot-Savart law for a large variety of 3-D “base” geometries in the Radia package. The significantly reduced CPU time and simple data input in conjunction with the consideration of realistic input variables, such as material-specific, temperature, and magnetic-field-dependent critical current densities, have enabled the Radia-based algorithm to outperform finite-element approaches in CPU time at the same accuracy levels. Comparative simulations of MgB2 and YBCO-based devices are performed at 4.2 K, in order to ascertain the realistic efficiency of the design configurations.

  14. Development of a superconducting joint between a GdBa2Cu3O7-δ-coated conductor and YBa2Cu3O7-δ bulk: towards a superconducting joint between RE (Rare Earth) Ba2Cu3O7-δ-coated conductors

    NASA Astrophysics Data System (ADS)

    Jin, Xinzhe; Yanagisawa, Yoshinori; Maeda, Hideaki; Takano, Yoshiki

    2015-07-01

    We have started to develop a superconducting bridge joint between two GdBa2Cu3O7-δ (Gd123)-coated conductors, where both conductors are placed in an end-to-end arrangement on the surface of a melt-textured YBCO (including Y2BaCuO5 and YBa2Cu3O7-δ) bulk, which acts as a superconducting medium between the coated conductors. As a first step in the development, one half of the bridge joint assembly was modeled and investigated. Experimental results achieved are as follows: (a) the higher-melting-temperature textured Gd123-coated conductor acts as a seed for the melt texture of the YBa2Cu3O7-δ (Y123) bulk, and (b) the superconducting phase continues across the Y123/Gd123 boundary. The critical current of the joint model is 10 A, which is about 10% of the original Gd123-coated conductor, at 77 K in a self-magnetic field. These results are considered to be extensible to the superconducting bridge joint between the Gd123-coated conductors.

  15. Catalytic thermal barrier coatings

    DOEpatents

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  16. Coated carbonaceous material

    SciTech Connect

    Young, C.B.F.

    1989-04-18

    This patent describes a coated fuel product comprising a piece of charcoal, and a glossy coating of paraffin completely enclosing the piece of charcoal, the charcoal further including a flammable liquid therein, the flammable liquid consisting of a light kerosene product and being sealed within the charcoal by the coating, the coating of paraffin consisting of from about 3 percent to about 7 percent by weight of the fuel product, and the flammable liquid consisting of from about 7 percent to 12 percent by weight of the fuel product. It also describes a similar product further including an additive for increasing the gloss of the coating, the additive being selected from the group consisting of polyethylene, stearic amide and monocrystalline wax.

  17. Thermal barrier coatings

    DOEpatents

    Alvin, Mary Anne

    2010-06-22

    This disclosure addresses the issue of providing a metallic-ceramic overlay coating that potentially serves as an interface or bond coat layer to provide enhanced oxidation resistance to the underlying superalloy substrate via the formation of a diffusion barrier regime within the supporting base material. Furthermore, the metallic-ceramic coating is expected to limit the growth of a continuous thermally grown oxide (TGO) layer that has been primarily considered to be the principal cause for failure of existing TBC systems. Compositional compatibility of the metallic-ceramic with traditional yttria-stabilized zirconia (YSZ) top coats is provided to further limit debond or spallation of the coating during operational use. A metallic-ceramic architecture is disclosed wherein enhanced oxidation resistance is imparted to the surface of nickel-based superalloy or single crystal metal substrate, with simultaneous integration of the yttria stabilized zirconia (YSZ) within the metallic-ceramic overlayer.

  18. LEVELING METAL COATINGS

    DOEpatents

    Gage, H.A.

    1959-02-10

    A method is described for applying metallic coatings to a cylinder of uranium. An aluminum-silicon coat is applied by a process consisting of first cleaning the article by immersion for 5 minutes in 50% nitric acid at 65 C. The article then is dipped through a flux, prepared by adding 10% sodium fluoride to 90% of a flux comprising 53% potassium chloride, 42% lithium chloride, and 5% sodium chloride at 560 for 2 minutes and then directly into a molten metal bath comprising 99% aluminun and 12% silicon at 620 C for 3 minutes. While the coating is yet molten the article is transferred to a pair of steel rollers and rolled until the coating solidifies. By varying the composition of the flux other metals such as zinc, lead or the like may be coated on uranium in a similar manner.

  19. Aerocoat 7 Replacement Coatings

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Kennedy Space Center has used Aerocoat 7 (AR-7) to protect stainless-steel flex hoses at Launch Complex (LC-39) and hydraulic lines of the Mobile Launcher Platform (MLP) because it provides excellent corrosion protection in low-temperature applications. The Sovereign Company produced AR-7 exclusively for NASA but discontinued production because the coating released high levels of volatile organic compounds (VOCs) and had a significant environmental impact. The purpose of this project was to select and evaluate potential replacement coatings for AR-7 that would be more environmentally sound. The physical and mechanical properties of commercially available coatings were investigated through the Internet. The ideal coating would be fluid enough to penetrate the outer mesh of a stainless-steel flex hose and coat the inner hose, and flexible enough to withstand the movement of the hose, as well as the expansion and contraction of its metal caused by changes in temperature.

  20. Coating Reduces Ice Adhesion

    NASA Technical Reports Server (NTRS)

    Smith, Trent; Prince, Michael; DwWeese, Charles; Curtis, Leslie

    2008-01-01

    The Shuttle Ice Liberation Coating (SILC) has been developed to reduce the adhesion of ice to surfaces on the space shuttle. SILC, when coated on a surface (foam, metal, epoxy primer, polymer surfaces), will reduce the adhesion of ice by as much as 90 percent as compared to the corresponding uncoated surface. This innovation is a durable coating that can withstand several cycles of ice growth and removal without loss of anti-adhesion properties. SILC is made of a binder composed of varying weight percents of siloxane(s), ethyl alcohol, ethyl sulfate, isopropyl alcohol, and of fine-particle polytetrafluoroethylene (PTFE). The combination of these components produces a coating with significantly improved weathering characteristics over the siloxane system alone. In some cases, the coating will delay ice formation and can reduce the amount of ice formed. SILC is not an ice prevention coating, but the very high water contact angle (greater than 140 ) causes water to readily run off the surface. This coating was designed for use at temperatures near -170 F (-112 C). Ice adhesion tests performed at temperatures from -170 to 20 F (-112 to -7 C) show that SILC is a very effective ice release coating. SILC can be left as applied (opaque) or buffed off until the surface appears clear. Energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) data show that the coating is still present after buffing to transparency. This means SILC can be used to prevent ice adhesion even when coating windows or other objects, or items that require transmission of optical light. Car windshields are kept cleaner and SILC effectively mitigates rain and snow under driving conditions.

  1. Isomolybdate conversion coatings

    NASA Technical Reports Server (NTRS)

    Minevski, Zoran (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating solution and process forms a stable and corrosion-resistant layer on metal substrates or layers or, more preferably, on a boehmite layer or other base conversion coating. The conversion coating process involves contacting the substrate, layer or coating with an aqueous alkali metal isomolybdate solution in order to convert the surface of the substrate, layer or coating to a stable conversion coating. The aqueous alkali metal molybdates are selected from sodium molybdate (Na.sub.2 MoO.sub.4), lithium molybdate (Li.sub.2 MoO.sub.4), potassium molybdate (K.sub.2 MoO.sub.4), or combinations thereof, with the most preferred alkali metal molybdate being sodium molybdate. The concentration of alkali metal molybdates in the solution is preferably less than 5% by weight. In addition to the alkali metal molybdates, the conversion coating solution may include alkaline metal passivators selected from lithium nitrate (LiNO.sub.3), sodium nitrate (NaNO.sub.3), ammonia nitrate (NH.sub.4 NO.sub.3), and combinations thereof; lithium chloride, potassium hexafluorozirconate (K.sub.2 ZrF.sub.6) or potassium hexafluorotitanate (K.sub.2 TiF.sub.6).

  2. Phenol-formaldehyde intumescent coating composition and coating prepared therefrom

    NASA Technical Reports Server (NTRS)

    Salyer, Ival O. (Inventor); Fox, Bernard L. (Inventor)

    1986-01-01

    Intumescent coatings which form a thick, uniform, fine celled, low density foam upon exposure to a high intensity heat flux or flame are disclosed, the invention coatings comprise phenolic resin prepolymer containing a blowing agent and a nucleating agent; in the preferred embodiments the coatings also contains a silicone surfactant, the coatings are useful in thermal and fire protection systems.

  3. COATING URANIUM FROM CARBONYLS

    DOEpatents

    Gurinsky, D.H.; Storrs, S.S.

    1959-07-14

    Methods are described for making adherent corrosion resistant coatings on uranium metal. According to the invention, the uranium metal is heated in the presence of an organometallic compound such as the carbonyls of nickel, molybdenum, chromium, niobium, and tungsten at a temperature sufficient to decompose the metal carbonyl and dry plate the resultant free metal on the surface of the uranium metal body. The metal coated body is then further heated at a higher temperature to thermally diffuse the coating metal within the uranium bcdy.

  4. Double-blind randomized study of 1 g versus 2 g intravenous ceftriaxone daily in the therapy of community-acquired infections.

    PubMed

    Segev, S; Raz, R; Rubinstein, E; Shmuely, H; Hassin, D; Rosen, N; Platau, E; Ben Assuli, S; Pitlik, S

    1995-10-01

    In a multicentre, double-blind, randomized study involving four general hospitals in Israel, the efficacy and safety of ceftriaxone 1 g/day i.v. was compared to that of 2 g/day i.v. in the treatment of moderate to severe community-acquired infections requiring hospitalization. Two hundred and twenty-two patients were enrolled; 112 received intravenous ceftriaxone 1 g/day, and 110 received 2 g/day. The two groups were matched demographically, and their mean APACHE II score (10 points) and mean duration of successful therapy (7 days) were identical. The sites of infection in the 1 g and 2 g groups respectively were lower respiratory tract in 57 versus 51 patients, urinary tract in 31 versus 40 patients, and soft tissue in 24 versus 19 patients. There were no significant differences in clinical outcome between the 1 g and 2 g groups, the outcome being cure in 91% versus 86% of patients, improvement in 3% versus 3% of patients, failure in 3% versus 8% of patients, and relapse in 3% versus 3% of patients. The findings of this study indicate that ceftriaxone 1 g/day is as effective as 2 g/day in the treatment of moderate to severe community-acquired infections. The low-dose form is a more economical means of treating these infections.

  5. An introduction to the design and fabrication progress of a megawatt class 2G HTS motor for the ship propulsion application

    NASA Astrophysics Data System (ADS)

    Moon, Heejong; Kim, Yeong-Chun; Park, Heui-Joo; Yu, In-Keun; Park, Minwon

    2016-03-01

    This paper introduces the design and fabrication progress of a megawatt class 2G high temperature superconductor (HTS) motor for the ship propulsion application at Doosan Heavy Industries and Construction. The purpose of this 2G HTS propulsion motor is to launch the business area for marine applications such as surface ship, submarine, merchant ship etc. The principles and interpretation of the magnetic field for 2G HTS motor and permanent magnet type motors are similar on the basis of 3D design and production. The most important component of an HTS motor is the rotor, which is composed of HTS coil, non-ferrous metal, torque disk, damper, and hollow shaft. A HTS rotor using hastelloy-based 2G HTS coils was designed and built. Open-circuit and short-circuit characteristics of the superconducting motor were investigated and compared with the analysis results at reduced excitation to verify the design. Preliminary testing of a 2G HTS motor has been conducted at a few hundred kilowatts as per the design. Through these results, we anticipate that most of the design criteria can be satisfied. However, we have faced several issues during the testing of the motor and these issues need to be resolved in order to take the design further.

  6. Structural basis for enhanced neutralization of HIV-1 by a dimeric IgG form of the glycan-recognizing antibody 2G12

    PubMed Central

    Wu, Yunji; West, Anthony P.; Kim, Helen J.; Thornton, Matthew E.; Ward, Andrew B.; Bjorkman, Pamela J.

    2013-01-01

    SUMMARY The human IgG 2G12 recognizes high-mannose carbohydrates on the HIV-1 envelope glycoprotein gp120. Its two antigen-binding fragments (Fabs) are intramolecularly domain exchanged, resulting in a rigid (Fab)2 unit including a third antigen-binding interface not found in antibodies with flexible Fab arms. We determined crystal structures of dimeric 2G12 IgG created by intermolecular domain exchange, which exhibits increased breadth and >50-fold increased neutralization potency compared with monomeric 2G12. The four Fab and two Fc regions of dimeric 2G12 were localized at low resolution in two independent structures, revealing IgG dimers with two (Fab)2 arms analogous to the Fabs of conventional monomeric IgGs. Structures revealed three conformationally-distinct dimers, demonstrating flexibility of the (Fab)2–Fc connections that was confirmed by electron microscopy, small-angle X-ray scattering, and binding studies. We conclude that intermolecular domain exchange, flexibility, and bivalent binding to allow avidity effects are responsible for the increased potency and breadth of dimeric 2G12. PMID:24316082

  7. Association between matrix metalloproteinase 1 -1607 1G>2G polymorphism and cancer risk: a meta-analysis including 19706 subjects.

    PubMed

    Han, Guoda; Wei, Zhijiang; Lu, Zhiliang; Cui, Haibin; Bai, Xiyong; Ge, Huai'e; Zhang, Wei

    2014-01-01

    The association between MMP1 -1607 1G>2G polymorphism and cancer risk has been reported, but results remained controversial and ambiguous. To assess the association between MMP1 -1607 1G>2G polymorphism and cancer risk, a meta-analysis was performed. Based on comprehensive searches of the PubMed, Elsevier Science Direct, Excerpta Medica Database (Embase), and Chinese Biomedical Literature Database (CBM), we identified outcome data from all articles estimating the association between MMP1 -1607 1G>2G polymorphism and cancer risk. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated. Thirty-eight studies involving 10178 cases and 9528 controls were included. Overall, significant association between MMP1 -1607 1G>2G polymorphism and cancer susceptibility was observed for additive model (OR = 1.21, 95% CI 1.09-1.35), for codominant model (OR = 1.34, 95% CI 1.10-1.63), for dominant model (OR = 1.17, 95% CI 1.01-1.34), for recessive model (OR = 1.31, 95% CI 1.14-1.52). In the subgroup analysis by ethnicity, the significant association was found among Asians but not among Caucasians. In the subgroup analysis by site of cancer, significant associations were found among lung cancer, colorectal cancer, head and neck cancer and bladder cancer. This meta-analysis demonstrated that the MMP1 -1607 1G>2G polymorphism was significantly associated with cancer risk.

  8. 'Mazatzal's' Many Coats

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This close-up image taken by the Mars Exploration Rover Spirit's microscopic imager shows a section of the hole drilled into the rock dubbed 'Mazatzal' after the hole was ground for a second time. The first drilling by the rover's rock abrasion tool left an incomplete hole, so a second one was performed. The blue arrow points to leftover portions of the dark rind that coats Mazatzal and the scrape marks left by the rock abrasion tool. The yellow arrow highlights the bright edges surrounding the leftover rind. The crack in the rock may have once contained fluids out of which minerals precipitated along its walls (red arrows). Mazatzal is a highly coated rock, containing at least four 'cake layers': a top coat of dust, a pinking coating, a dark rind and its true interior. The observed area is 3 centimeters (1.2 inches) across. This image was taken on sol 85.

  9. Multilayer optical dielectric coating

    DOEpatents

    Emmett, John L.

    1990-01-01

    A highly damage resistant, multilayer, optical reflective coating includes alternating layers of doped and undoped dielectric material. The doping levels are low enough that there are no distinct interfaces between the doped and undoped layers so that the coating has properties nearly identical to the undoped material. The coating is fabricated at high temperature with plasma-assisted chemical vapor deposition techniques to eliminate defects, reduce energy-absorption sites, and maintain proper chemical stoichiometry. A number of differently-doped layer pairs, each layer having a thickness equal to one-quarter of a predetermined wavelength in the material are combined to form a narrowband reflective coating for a predetermined wavelength. Broadband reflectors are made by using a number of narrowband reflectors, each covering a portion of the broadband.

  10. Super Thin Ceramic Coatings

    NASA Video Gallery

    New technology being developed at NASA's Glenn Research Center creates super thin ceramic coatings on engine components. The Plasma Spray – Physical Vapor Deposition (PS-PVD) rig uses a powerful ...

  11. Aluminum phosphate coatings

    DOEpatents

    Sambasivan, Sankar; Steiner, Kimberly A.; Rangan, Krishnaswamy K.

    2007-12-25

    Aluminophosphate compounds and compositions as can be used for substrate or composite films and coating to provide or enhance, without limitation, planarization, anti-biofouling and/or anti-microbial properties.

  12. POWDER COAT APPLICATIONS

    EPA Science Inventory

    The report discusses an investigation of critical factors that affect the use of powder coatings on the environment, cost, quality, and production. The investigation involved a small business representative working with the National Defense Center for Environmental Excellence (ND...

  13. Coated particle waste form development

    NASA Astrophysics Data System (ADS)

    Oma, K. H.; Buckwalter, C. Q.; Chick, L. A.

    1981-12-01

    Coated particle waste forms were developed as part of the multibarrier concept. Primary efforts were to coat simulated nuclear waste glass marbles and ceramic pellets with low temperature pyrolytic carbon (LT-PyC) coatings via the process of chemical vapor deposition (CVD). Fluidized bed coaters, screw agitated coaters, and rotating tube coaters were used. Coating temperatures were reduced by using catalysts and plasma activation. In general, the LT-PyC coatings did not provide the expected high leach resistance as previously measured for carbon alone. The coatings were friable and often spalled off the substrate. A totally different concept, thermal spray coating, was investigated as an alternative to CVD coating. Flame spray, wire gun, and plasma gun systems were evaluated using glass, ceramic, and metallic coating materials. Metal plasma spray coatings (Al, Sn, Zn, Pb) provided a two to three orders of magnitude increase in chemical durability.

  14. Friction surfaced Stellite6 coatings

    SciTech Connect

    Rao, K. Prasad; Damodaram, R.; Rafi, H. Khalid; Ram, G.D. Janaki; Reddy, G. Madhusudhan; Nagalakshmi, R.

    2012-08-15

    Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material for friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.

  15. Preventing Cracking of Anodized Coatings

    NASA Technical Reports Server (NTRS)

    He, Charles C.; Heslin, Thomas M.

    1995-01-01

    Anodized coatings have been used as optical and thermal surfaces in spacecraft. Particulate contamination from cracked coatings is a concern for many applications. The major cause for the cracking is the difference in the coefficient of thermal expansion between the oxide coatings and the aluminum substrate. The loss of water when the coating is exposed to a vacuum also could induce cracking of the coating. Hot-water sealing was identified as the major cause for the cracking of the coatings because of the large temperature change when the parts were immersed in boiling water and the water was absorbed in the coating. when the hot-water sealing process was eliminated, the cracking resistance of the anodized coatings was greatly improved. Also, it was found that dyed black coatings were more susceptible than clear coatings to cracking during thermo-vacuum cyclings.

  16. Electrodeposited Biaxially Textured CeO2 and CeO2:Sm Buffer Layer for YBCO Superconductor Oxide Films

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Raghu; Phok, Sovannary; Spagnol, Priscila; Chaudhuri, Tapas

    2006-03-01

    Nonvacuum electrodeposition was used to prepare biaxially textured CeO2 and Sm-doped CeO2 coatings on Ni-W substrates. The samples were characterized by X-ray diffraction (including θ/2θ, pole figures, omega scans, and phi scans), atomic force microscopy (AFM), Auger electron spectroscopy (AES), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Full-width at half-maximum values of the ω scan and φ scan of the electrodeposited layers were better than those of the Ni-W base substrates, indicating improved biaxial texturing of the electrodeposited layers.

  17. Ceramic electrolyte coating methods

    DOEpatents

    Seabaugh, Matthew M.; Swartz, Scott L.; Dawson, William J.; McCormick, Buddy E.

    2004-10-12

    Processes for preparing aqueous suspensions of a nanoscale ceramic electrolyte material such as yttrium-stabilized zirconia. The invention also includes a process for preparing an aqueous coating slurry of a nanoscale ceramic electrolyte material. The invention further includes a process for depositing an aqueous spray coating slurry including a ceramic electrolyte material on pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

  18. Intumescent coating development

    NASA Technical Reports Server (NTRS)

    Sayler, I. O.; Griffen, C. W.

    1983-01-01

    A program was completed at the University of Dayton Research Institute in which polyimide and phenolic intumescent coatings were evaluated as supplemental thermal insulation for the sprayed-on foam insulation on the aft bulkhead of the space shuttle external tank. The purpose of the intumescent coating was to provide additional thermal protection during lift-off in order to replace the ablative heat resistant layer with a lighter weight material for increased payload in the shuttle.

  19. Spin coating apparatus

    DOEpatents

    Torczynski, John R.

    2000-01-01

    A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

  20. Nanostructured Superhydrophobic Coatings

    SciTech Connect

    2009-03-01

    This factsheet describes a research project that deals with the nanostructured superhydrophobic (SH) powders developed at ORNL. This project seeks to (1) improve powder quality; (2) identify binders for plastics, fiberglass, metal (steel being the first priority), wood, and other products such as rubber and shingles; (3) test the coated product for coating quality and durability under operating conditions; and (4) application testing and production of powders in quantity.

  1. METAL COATING BATHS

    DOEpatents

    Robinson, J.W.

    1958-08-26

    A method is presented for restoring the effectiveness of bronze coating baths used for hot dip coating of uranium. Such baths, containing a high proportion of copper, lose their ability to wet uranium surfaces after a period of use. The ability of such a bath to wet uranium can be restored by adding a small amount of metallic aluminum to the bath, and skimming the resultant hard alloy from the surface.

  2. Interaction analysis of HIV-1 antibody 2G12 and Man9GlcNAc2 ligand: Theoretical calculations by fragment molecular orbital and MD methods

    NASA Astrophysics Data System (ADS)

    Koyama, Yuka; Ueno-Noto, Kaori; Takano, Keiko

    2013-07-01

    In HIV-1 infection, human antibody 2G12 is capable of recognizing the high-mannose glycans on the HIV-1 surface glycoprotein, gp120. To investigate the ligand binding mechanisms of antibody 2G12 with glycans aiming for the contribution to the medications, we carried out classical molecular dynamics (MD) simulations and ab initio fragment molecular orbital (FMO) calculations on the antibody 2G12 complex with its high-mannose ligand. We found that Mannose D1 of the ligand had the largest binding affinity with the antibody, which was well consistent with experimental reports. Furthermore, significant roles of Mannose 4 and 4‧ in the ligand binding were theoretically indicated.

  3. Fc-glycosylation influences Fcγ receptor binding and cell-mediated anti-HIV activity of monoclonal antibody 2G12.

    PubMed

    Forthal, Donald N; Gach, Johannes S; Landucci, Gary; Jez, Jakub; Strasser, Richard; Kunert, Renate; Steinkellner, Herta

    2010-12-01

    Interactions between the Fc segment of IgG and FcγRs on a variety of cells are likely to play an important role in the anti-HIV activity of Abs. Because the nature of the glycan structure on the Fc domain is a critical determinant of Fc-FcγR binding, proper Fc glycosylation may contribute to Ab-mediated protection. We have generated five different glycoforms of the broadly HIV-1-neutralizing mAb 2G12 in wild-type and glycoengineered plants and Chinese hamster ovary cells. Plant-derived 2G12 exhibited highly homogeneous glycosylation profiles with a single dominant N-glycan species. Using flow cytometry with FcγR-expressing cell lines, all 2G12 glycoforms demonstrated similar binding to FcγRI, FcγRIIa, and FcγRIIb. In contrast, two glycoforms derived from glycoengineered plants that lack plant-specific xylose and core α1,3-fucose, and instead carry human-like glycosylation with great uniformity, showed significantly enhanced binding to FcγRIIIa compared with Chinese hamster ovary or wild-type plant-derived 2G12. Using surface plasmon resonance, we show that binding of 2G12 to FcγRIIIa is markedly affected by core fucose, irrespective of its plant-specific α1,3 or mammalian-type α1,6 linkage. Consistent with this finding, 2G12 glycoforms lacking core fucose (and xylose) mediated higher antiviral activity against HIV-1 or simian immunodeficiency virus as measured by Ab-dependent cell-mediated virus inhibition. This is, to our knowledge, the first demonstration that specific alterations of Fc glycosylation can improve antiviral activity. Such alterations may result in better immunotherapeutic reagents. Moreover, biasing vaccine-induced immune responses toward optimal Fc glycosylation patterns could result in improved vaccine efficacy. PMID:21041724

  4. Multilayer thermal barrier coating systems

    DOEpatents

    Vance, Steven J.; Goedjen, John G.; Sabol, Stephen M.; Sloan, Kelly M.

    2000-01-01

    The present invention generally describes multilayer thermal barrier coating systems and methods of making the multilayer thermal barrier coating systems. The thermal barrier coating systems comprise a first ceramic layer, a second ceramic layer, a thermally grown oxide layer, a metallic bond coating layer and a substrate. The thermal barrier coating systems have improved high temperature thermal and chemical stability for use in gas turbine applications.

  5. Coated particle waste form development

    SciTech Connect

    Oma, K.H.; Buckwalter, C.Q.; Chick, L.A.

    1981-12-01

    Coated particle waste forms have been developed as part of the multibarrier concept at Pacific Northwest Laboratory under the Alternative Waste Forms Program for the Department of Energy. Primary efforts were to coat simulated nuclear waste glass marbles and ceramic pellets with low-temperature pyrolytic carbon (LT-PyC) coatings via the process of chemical vapor deposition (CVD). Fluidized bed (FB) coaters, screw agitated coaters (SAC), and rotating tube coaters were used. Coating temperatures were reduced by using catalysts and plasma activation. In general, the LT-PyC coatings did not provide the expected high leach resistance as previously measured for carbon alone. The coatings were friable and often spalled off the substrate. A totally different concept, thermal spray coating, was investigated at PNL as an alternative to CVD coating. Flame spray, wire gun, and plasma gun systems were evaluated using glass, ceramic, and metallic coating materials. Metal plasma spray coatings (Al, Sn, Zn, Pb) provided a two to three orders-of-magnitude increase in chemical durability. Because the aluminum coatings were porous, the superior leach resistance must be due to either a chemical interaction or to a pH buffer effect. Because they are complex, coated waste form processes rank low in process feasibility. Of all the possible coated particle processes, plasma sprayed marbles have the best rating. Carbon coating of pellets by CVD ranked ninth when compared with ten other processes. The plasma-spray-coated marble process ranked sixth out of eleven processes.

  6. Controlled Thermal Expansion Coat for Thermal Barrier Coatings

    NASA Technical Reports Server (NTRS)

    Brindley, William J. (Inventor); Miller, Robert A. (Inventor); Aikin, Beverly J. M. (Inventor)

    1999-01-01

    A improved thermal barrier coating and method for producing and applying such is disclosed herein. The thermal barrier coating includes a high temperature substrate, a first bond coat layer applied to the substrate of MCrAlX, and a second bond coat layer of MCrAlX with particles of a particulate dispersed throughout the MCrAlX and the preferred particulate is Al2O3. The particles of the particulate dispersed throughout the second bond coat layer preferably have a diameter of less then the height of the peaks of the second bond coat layer, or a diameter of less than 5 microns. The method of producing the second bond coat layer may either include the steps of mechanical alloying of particles throughout the second bond coat layer, attrition milling the particles of the particulate throughout the second bond coat layer, or using electrophoresis to disperse the particles throughout the second bond coat layer. In the preferred embodiment of the invention, the first bond coat layer is applied to the substrate, and then the second bond coat layer is thermally sprayed onto the first bond coat layer. Further, in a preferred embodiment of die invention, a ceramic insulating layer covers the second bond coat layer.

  7. Thermal barrier coating system with intermetallic overlay bond coat

    SciTech Connect

    Duderstadt, E.C.; Nagaraj, B A.

    1993-08-24

    A superalloy article is described having a thermal barrier coating system thereon, comprising: a substrate made of a material selected from the group consisting of a nickel-based superalloy and a cobalt-based superalloy; and a thermal barrier coating system on the substrate, the thermal barrier coating system including an intermetallic bond coat overlying the substrate, the bond coat being selected from the group consisting of a nickel aluminide and a platinum aluminide intermetallic compound, a thermally grown aluminum oxide layer overlying the intermetallic bond coat, and a ceramic topcoat overlying the aluminum oxide layer.

  8. Epitaxial growth of Ce 2Y 2O 7 buffer layers for YBa 2Cu 3O 7-δ coated conductors using reel-to-reel DC reactive sputtering

    NASA Astrophysics Data System (ADS)

    Fan, F.; Lu, Y. M.; Ying, L. L.; Liu, Z. Y.; Cai, C. B.; Hühne, R.; Holzapfel, B.

    2011-08-01

    Biaxially textured Ce 2Y 2O 7 (CYO) films were deposited on Ni-5at.%W (Ni-5W) tapes by a DC reactive sputtering technique in a reel-to-reel system. Subsequent YBa 2Cu 3O 7-δ (YBCO) films were prepared using pulsed laser deposition leading to a simplified coated conductor architecture of YBCO/CYO/Ni-5W. X-ray diffraction measurements revealed an epitaxial growth of the CYO buffer layer with a texture spread down to 2.2° and 4.7° for the out-of-plane and in-plane alignment, respectively. Microstructural investigations showed a dense, smooth and crack-free surface morphology for CYO film up to a thickness of 350 nm, implying an effective suppression of cracks due to the incorporation of Y in CeO 2. The superconducting transition temperature T c of about 90 K with a narrow transition of 0.8 K and the inductively measured critical current density J c of about 0.7 MA/cm 2 indicate the potential of the single CYO buffer layer.

  9. Fabrication and characterization of La2Zr2O7 films on different buffer architectures for YBa2Cu3O7-δ coated conductors by RF magnetron sputtering.

    PubMed

    Xu, Da; Liu, Linfei; Xiao, Guina; Li, Yijie

    2013-02-27

    La2Zr2O7 (LZO) films were grown on different buffer architectures by radio frequency magnetron sputtering for the large-scale application of YBa2Cu3O7-x (YBCO)-coated conductors. The three different buffer architectures were cerium oxide (CeO2), yttria-stabilized zirconia (YSZ)/CeO2, and CeO2/YSZ/CeO2. The microstructure and surface morphology of the LZO film were studied by X-ray diffraction, optical microscopy, field emission scanning electron microscopy, and atomic force microscopy. The LZO films prepared on the CeO2, YSZ/CeO2, and CeO2/YSZ/CeO2 buffer architectures were preferentially c-axis-oriented and highly textured. The in-plane texture of LZO film on CeO2 single-buffer architecture was ∆ φ = 5.5° and the out-of-plane texture was ∆ ω = 3.4°. All the LZO films had very smooth surfaces, but LZO films grown on YSZ/CeO2 and CeO2/YSZ/CeO2 buffer architectures had cracks. The highly textured LZO film grown on CeO2-seed buffered NiW tape was suitable for the epitaxial growth of YBCO film with high currents.

  10. The roles of sPLA2-IIA (Pla2g2a) in cancer of the small and large intestine.

    PubMed

    Fijneman, Remond J A; Cormier, Robert T

    2008-05-01

    The mouse secretory phospholipase A2 group IIA (sPLA2-IIA) gene Pla2g2a has been identified as a susceptibility gene for cancer of the small and large intestine. Interestingly, unlike most previously identified tumor susceptibility genes, Pla2g2a does not behave like a classical oncogene or tumor suppressor gene. Hence, identification of its biological functions in tumor development may shed new light on general mechanisms that modulate colon cancer risk. So far, sPLA2-IIA has been proposed to play a role in anti-bacterial defense, inflammation and eicosanoid generation, in clearance of apoptotic cells, and in the Wnt signaling pathway. More recently, comparison of RNA expression profiles of colon from Pla2g2a-transgenic to Pla2g2a-deficient mice confirmed and even extended sPLA2-IIA's diverse biological effects. In this review we aim to summarize current knowledge about the various links of sPLA2-IIA to cancer of the gastro-intestinal tract, and propose several models to illustrate its putative biological effects on tumor development.

  11. Development of V2G and G2V Power Profiles and Their Implications on Grid Under Varying Equilibrium of Aggregated Electric Vehicles

    NASA Astrophysics Data System (ADS)

    Jain, Prateek; Jain, Trapti

    2016-04-01

    The objective of this paper is to examine the vehicle-to-grid (V2G) power capability of aggregated electric vehicles (EV) in the manner that they are being adopted by the consumers with their growing infiltration in the vehicles market. The proposed modeling of V2G and grid-to-vehicle (G2V) energy profiles blends the heterogeneous attributes namely, driven mileages, arrival and departure times, travel and parking durations, and speed dependent energy consumption of mobility trends. Three penetration percentages of 25 %, 50 % and 100 % resulting in varied compositions of battery electric vehicle (BEV) and plug-in hybrid electric vehicle (PHEV) in the system, as determined by the consumers' acceptance, have been considered to evaluate the grid capacity for V2G. Distinct charge-discharge powers have been selected as per charging standards to match contemporary vehicles and infrastructure requirements. Charging and discharging approaches have been devised to replicate non-linear characteristics of Li-ion battery. Effects of simultaneous conjunction of V2G and G2V power curves with daily conventional load profile are quantified drawn upon workplace-discharging home-charging scheme. Results demonstrated a marked drop in load and hence in market price during morning hours which is hurriedly overcompensated by the hike during evening hours with rising penetration level and charge-discharge power.

  12. The structure at 1.7 Å resolution of the protein product of the At2g17340 gene from Arabidopsis thaliana

    PubMed Central

    Bitto, Eduard; Bingman, Craig A.; Allard, Simon T. M.; Wesenberg, Gary E.; Phillips, George N.

    2005-01-01

    The crystal structure of the At2g17340 protein from A. thaliana was determined by the multiple-wavelength anomalous diffraction method and was refined to an R factor of 16.9% (R free = 22.1%) at 1.7 Å resolution. At2g17340 is a member of the Pfam01937.11 protein family and its structure provides the first insight into the structural organization of this family. A number of fully and highly conserved residues defined by multiple sequence alignment of members of the Pfam01937.11 family were mapped onto the structure of At2g17340. The fully conserved residues are involved in the coordination of a metal ion and in the stabilization of loops surrounding the metal site. Several additional highly conserved residues also map into the vicinity of the metal-binding site, while others are clearly involved in stabilizing the hydrophobic core of the protein. The structure of At2g17340 represents a new fold in protein conformational space. PMID:16511115

  13. Widespread Lewy body and tau accumulation in childhood and adult onset dystonia-parkinsonism cases with PLA2G6 mutations

    PubMed Central

    Paisán-Ruiz, Coro; Li, Abi; Schneider, Susanne A.; Holton, Janice L.; Johnson, Robert; Kidd, Desmond; Chataway, Jeremy; Bhatia, Kailash P.; Lees, Andrew J.; Hardy, John; Revesz, Tamas; Houlden, Henry

    2012-01-01

    The 2 major types of neurodegeneration with brain iron accumulation (NBIA) are the pantothenate kinase type 2 (PANK2)-associated neurodegeneration (PKAN) and NBIA2 or infantile neuroaxonal dystrophy (INAD) due to mutations in the phospholipase A2, group VI (PLA2G6) gene. We have recently demonstrated clinical heterogeneity in patients with mutations in the PLA2G6 gene by identifying a poorly defined subgroup of patients who present late with dystonia and parkinsonism. We report the clinical and genetic features of 7 cases with PLA2G6 mutations. Brain was available in 5 cases with an age of death ranging from 8 to 36 years and showed widespread alpha-synuclein-positive Lewy pathology, which was particularly severe in the neocortex, indicating that the Lewy pathology spread corresponded to Braak stage 6 and was that of the “diffuse neocortical type”. In 3 cases there was hyperphosphorylated tau accumulation in both cellular processes as threads and neuronal perikarya as pretangles and neurofibrillary tangles. Later onset cases tended to have less tau involvement but still severe alpha-synuclein pathology. The clinical and neuropathological features clearly represent a link between PLA2G6 and parkinsonian disorders. PMID:20619503

  14. Protective coatings for concrete

    SciTech Connect

    NAGY, KATHRYN L.; CYGAN, RANDALL T.; BRINKER, C. JEFFREY; SELLINGER, ALAN

    2000-05-01

    The new two-layer protective coating developed for monuments constructed of limestone or marble was applied to highway cement and to tobermorite, a component of cement, and tested in batch dissolution tests. The goal was to determine the suitability of the protective coating in retarding the weathering rate of concrete construction. The two-layer coating consists of an inner layer of aminoethylaminopropylsilane (AEAPS) applied as a 25% solution in methanol and an outer layer of A2** sol-gel. In previous work, this product when applied to calcite powders, had resulted in a lowering of the rate of dissolution by a factor of ten and was shown through molecular modeling to bind strongly to the calcite surface, but not too strongly so as to accelerate dissolution. Batch dissolution tests at 22 C of coated and uncoated tobermorite (1.1 nm phase) and powdered cement from Gibson Blvd. in Albuquerque indicated that the coating exhibits some protective behavior, at least on short time scales. However, the data suggest that the outer layer of sol-gel dissolves in the high-pH environment of the closed system of cement plus water. Calculated binding configuration and energy of AEAPS to the tobermorite surface suggests that AEAPS is well-suited as the inner layer binder for protecting tobermorite.

  15. Coatings for directional eutectics

    NASA Technical Reports Server (NTRS)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  16. Based Adaptive Nanocomposite Coatings

    NASA Astrophysics Data System (ADS)

    Ramazani, M.; Ashrafizadeh, F.; Mozaffarinia, R.

    2014-08-01

    A promising Ni(Al)-Cr2O3-Ag-CNT-WS2 self-lubricating wear-resistant coating was deposited via atmospheric plasma spray of Ni(Al), nano Cr2O3, nano silver and nano WS2 powders, and CNTs. Feedstock powders with various compositions prepared by spray drying were plasma sprayed onto carbon steel substrates. The tribological properties of coatings were tested by a high temperature tribometer in a dry environment from room temperature to 400 °C, and in a natural humid environment at room temperature. It was found that all nanocomposite coatings have better frictional behavior compared with pure Ni(Al) and Ni(Al)-Cr2O3 coatings; the specimen containing aproximately 7 vol.% Ag, CNT, and WS2 had the best frictional performance. The average room temperature friction coefficient of this coating was 0.36 in humid atmosphere, 0.32 in dry atmosphere, and about 0.3 at high temperature.

  17. Combined magnetic screen made of Bi-2223 bulk cylinder and YBCO tape rings—Modeling and experiments

    NASA Astrophysics Data System (ADS)

    Tomków, Ł.; Ciszek, M.; Chorowski, M.

    2015-01-01

    Recent advances in the measurements with sensitive magnetic field sensors made the issue of magnetic shielding important. The application of high temperature superconductors allows to obtain full shielding in zero field cooling conditions for DC and low frequency magnetic fields by the means of the Meissner effect. However, currently used conventional bulk magnetic shields maintain full shielding only in low magnetic fields—up to approximately 10 mT. In this paper, it is proposed to apply an additional screen made of a coated superconducting tape in order to increase the magnetic field interval of full shielding region. Computer model of such set of screens was created in Matlab and validated experimentally. Improvement of shielding quality was observed experimentally and calculated with the model.

  18. Functional interaction between herpes simplex virus type 2 gD and HVEM transiently dampens local chemokine production after murine mucosal infection.

    PubMed

    Yoon, Miri; Kopp, Sarah J; Taylor, Joann M; Storti, Christopher S; Spear, Patricia G; Muller, William J

    2011-01-24

    Herpes virus entry mediator (HVEM) is one of two principal receptors mediating herpes simplex virus (HSV) entry into murine and human cells. It functions naturally as an immune signaling co-receptor, and may participate in enhancing or repressing immune responses depending on the natural ligand used. To investigate whether engagement of HVEM by HSV affects the in vivo response to HSV infection, we generated recombinants of HSV-2(333) that expressed wild-type gD (HSV-2/gD) or mutant gD able to bind to nectin-1 (the other principal entry receptor) but not HVEM. Replication kinetics and yields of the recombinant strains on Vero cells were indistinguishable from those of wild-type HSV-2(333). After intravaginal inoculation with mutant or wild-type virus, adult female C57BL/6 mice developed vaginal lesions and mortality in similar proportions, and mucosal viral titers were similar or lower for mutant strains at different times. Relative to HSV-2/gD, percentages of HSV-specific CD8(+) T-cells were similar or only slightly reduced after infection with the mutant strain HSV-2/gD-Δ7-15, in all tissues up to 9 days after infection. Levels of HSV-specific CD4(+) T-cells five days after infection also did not differ after infection with either strain. Levels of the cytokine IL-6 and of the chemokines CXCL9, CXCL10, and CCL4 were significantly lower in vaginal washes one day after infection with HSV-2/gD compared with HSV-2/gD-Δ7-15. We conclude that the interaction of HSV gD with HVEM may alter early innate events in the murine immune response to infection, without significantly affecting acute mortality, morbidity, or initial T-cell responses after lethal challenge.

  19. Corrosion resistant coatings. (Latest citations from World Surface Coatings abstracts). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations concerning anticorrosive protective coatings. Patents include surface treatments, paints, antistatic coatings, silicate coatings, fatty acids, organic and inorganic materials, and techniques for applying various coatings. Citations concerning epoxy coatings, acrylic and acrylate coatings, urethane coatings, and water-borne coatings are excluded and examined in separate bibliographies. (Contains 250 citations and includes a subject term index and title list.)

  20. METHOD OF PROTECTIVELY COATING URANIUM

    DOEpatents

    Eubank, L.D.; Boller, E.R.

    1959-02-01

    A method is described for protectively coating uranium with zine comprising cleaning the U for coating by pickling in concentrated HNO/sub 3/, dipping the cleaned U into a bath of molten zinc between 430 to 600 C and containing less than 0 01% each of Fe and Pb, and withdrawing and cooling to solidify the coating. The zinccoated uranium may be given a; econd coating with another metal niore resistant to the corrosive influences particularly concerned. A coating of Pb containing small proportions of Ag or Sn, or Al containing small proportions of Si may be applied over the zinc coatings by dipping in molten baths of these metals.

  1. Electrodeposition of nickel composite coatings

    NASA Astrophysics Data System (ADS)

    Borkar, Tushar

    Pulse electrodeposition (PC) and pulse reverse electrodeposition (PRC) bring a new era in improving the surface properties of metals. These processes are associated with many advantages, such as reduction in porosity, low level of inclusions, and higher deposition rates compared to direct current (DC) electrodeposition process. There is much more flexibility in varying three basic parameters which are, pulse current density, on time, and off time in pulse electrodeposition resulting in unique composition and microstructure of coating being deposited. In this work, nickel matrix composite coatings were synthesized by co-depositing nano particles (Al2O3, SiC, and ZrO2) from Watts bath. To get detailed insight into effect of processing parameters on the microstructure, mechanical, and tribological properties of the composite coatings, the coatings were also fabricated using DC, PC, and PRC techniques. Also, the effect of bath loading on the level of reinforcement in the coating was investigated for Ni-Al2O 3 composite coatings. Furthermore an attempt was made to produce Ni-CNT coatings by pulse electrodeposition method. Pure nickel coatings were also prepared for comparison. Composite coatings deposited using PC and PRC techniques exhibited significant improvement in microhardness and wear resistance. The presence of nanoparticles in the composite coating seems to prohibit the columnar growth of the nickel grains resulting in random/weak texture and smaller thickness of the composite coatings. Ni-Al2O3 composite coatings show maximum hardness and wear resistance compared to Ni-SiC and Ni-ZrO 2 composite coatings. As Al2O3 content in electroplating bath increases, Microhardness and wear resistance of composite coatings increases but thickness of the coatings decreases due to nanoparticles obstructing grain growth. The Ni-CNT composite coatings exhibited significantly improved microhardness compared to pure nickel coatings.

  2. Coated microneedles for transdermal delivery

    PubMed Central

    Gill, Harvinder S.; Prausnitz, Mark R.

    2007-01-01

    Coated microneedles have been shown to deliver proteins and DNA into the skin in a minimally invasive manner. However, detailed studies examining coating methods and their breadth of applicability are lacking. This study’s goal was to develop a simple, versatile and controlled microneedle coating process to make uniform coatings on microneedles and establish the breadth of molecules and particles that can be coated onto microneedles. First, microneedles were fabricated from stainless steel sheets as single microneedles or arrays of microneedles. Next, a novel micron-scale dip-coating process and a GRAS coating formulation were designed to reliably produce uniform coatings on both individual and arrays of microneedles. This process was used to coat compounds including calcein, vitamin B, bovine serum albumin and plasmid DNA. Modified vaccinia virus and microparticles of 1 to 20 μm diameter were also coated. Coatings could be localized just to the needle shafts and formulated to dissolve within 20 s in porcine cadaver skin. Histological examination validated that microneedle coatings were delivered into the skin and did not wipe off during insertion. In conclusion, this study presents a simple, versatile, and controllable method to coat microneedles with proteins, DNA, viruses and microparticles for rapid delivery into the skin. PMID:17169459

  3. Preparation of hydrophobic coatings

    DOEpatents

    Branson, Eric D.; Shah, Pratik B.; Singh, Seema; Brinker, C. Jeffrey

    2009-02-03

    A method for preparing a hydrophobic coating by preparing a precursor sol comprising a metal alkoxide, a solvent, a basic catalyst, a fluoroalkyl compound and water, depositing the precursor sol as a film onto a surface, such as a substrate or a pipe, heating, the film and exposing the film to a hydrophobic silane compound to form a hydrophobic coating with a contact angle greater than approximately 150.degree.. The contact angle of the film can be controlled by exposure to ultraviolet radiation to reduce the contact angle and subsequent exposure to a hydrophobic silane compound to increase the contact angle.

  4. Thermal Barrier Coating Workshop

    NASA Technical Reports Server (NTRS)

    Brindley, W. J. (Compiler); Lee, W. Y. (Compiler); Goedjen, J. G. (Compiler); Dapkunas, S. J. (Compiler)

    1995-01-01

    This document contains the agenda and presentation abstracts for the Thermal Barrier Coating Workshop, sponsored by NASA, DOE, and NIST. The workshop covered thermal barrier coating (TBC) issues related to applications, processing, properties, and modeling. The intent of the workshop was to highlight the state of knowledge on TBC's and to identify critical gaps in knowledge that may hinder TBC use in advanced applications. The workshop goals were achieved through presentations by 22 speakers representing industry, academia, and government as well as through extensive discussion periods.

  5. Tribology and coatings

    SciTech Connect

    1995-06-01

    The future use of fuel-efficient, low-emission, advanced transportation systems (for example, those using low-heat-rejection diesel engines or advanced gas turbines) presents new challenges to tribologists and materials scientists. High service temperatures, corrosive environments, and extreme contact pressures are among the concerns that make necessary new tribological designs, novel materials, and effective lubrication concepts. Argonne is working on methods to reduce friction, wear and corrosion, such as soft metal coatings on ceramics, layered compounds, diamond coatings, and hard surfaces.

  6. Advanced Coating Removal Techniques

    NASA Technical Reports Server (NTRS)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  7. Fiber coating method

    DOEpatents

    Corman, Gregory Scot

    2003-04-15

    A coating is applied to reinforcing fibers arranged into a tow by coaxially aligning the tow with an adjacent separation layer and winding or wrapping the tow and separation layer onto a support structure in an interleaved manner so that the separation layer separates a wrap of the tow from an adjacent wrap of the tow. A coating can then be uniformly applied to the reinforcing fibers without defects caused by fiber tow to fiber tow contact. The separation layer can be a carbon fiber veil.

  8. Fiber coating method

    DOEpatents

    Corman, Gregory Scot

    2001-01-01

    A coating is applied to reinforcing fibers arranged into a tow by coaxially aligning the tow with an adjacent separation layer and winding or wrapping the tow and separation layer onto a support structure in an interleaved manner so that the separation layer separates a wrap of the tow from an adjacent wrap of the tow. A coating can then be uniformly applied to the reinforcing fibers without defects caused by fiber tow to fiber tow contact. The separation layer can be a carbon fiber veil.

  9. Templated biomimetic multifunctional coatings

    NASA Astrophysics Data System (ADS)

    Sun, Chih-Hung; Gonzalez, Adriel; Linn, Nicholas C.; Jiang, Peng; Jiang, Bin

    2008-02-01

    We report a bioinspired templating technique for fabricating multifunctional optical coatings that mimic both unique functionalities of antireflective moth eyes and superhydrophobic cicada wings. Subwavelength-structured fluoropolymer nipple arrays are created by a soft-lithography-like process. The utilization of fluoropolymers simultaneously enhances the antireflective performance and the hydrophobicity of the replicated films. The specular reflectivity matches the optical simulation using a thin-film multilayer model. The dependence of the size and the crystalline ordering of the replicated nipples on the resulting antireflective properties have also been investigated by experiment and modeling. These biomimetic materials may find important technological application in self-cleaning antireflection coatings.

  10. Low-cost and high-power-density resistive fault-current limiting elements using YBCO thin films and Au-Ag alloy shunt layers

    NASA Astrophysics Data System (ADS)

    Yamasaki, H.; Arai, K.; Furuse, M.; Kaiho, K.; Nakagawa, Y.

    2006-06-01

    We propose a new design for the high-temperature superconducting thin-film faultcurrent limiter (FCL), which uses high-resistivity Au-Ag alloy shunt layers instead of the pure gold (or silver) shunt layers conventionally used. An FCL element (5 mm wide and 40 mm long) with a YBCO thin film (THEVA) and a parallel inductively-wound shunt resistor successfully withstood very high electric field (> 44 Vpeak/cm) for 5 cycles (0.1 sec) after switching, and achieved a very high switching power density, ~2.0 kVA/cm2. We confirmed similar maximum tolerable electric field (>40 Vpeak/cm, limited by power supply) in a larger sample (1 cm × 6 cm). The composition of our FCL element is very simple, and the achieved power density is more than five times higher than conventional devices, which leads to a dramatic reduction in the amount of expensive superconducting thin films. We made a conceptual design and cost estimation of our FCL elements used in a typical 6.6 kV FCL.

  11. Parylene coating for circuit components

    NASA Technical Reports Server (NTRS)

    Berkebile, M. J.; Holbrook, R. J.; Oberin, F. W.

    1977-01-01

    Inexpensive internal coating improves reliability of plastic-packaged parts. Coating protects device from effects of humidity and heat and acts as barrier between device and harmful substances generated by plastic-packaging material.

  12. Multilayer coatings on flexible substrates

    SciTech Connect

    Martin, P.M.; Affinito, J.D.; Gross, M.E.; Coronado, C.A.; Bennett, W.D.; Stewart, D.C.

    1995-04-01

    Thin-film optical and non-optical multilayer coatings are deposited onto flexible substrates using a vacuum web coater developed at Pacific Northwest Laboratory. The coater`s primary application is rapid prototyping of multilayer (1) polymer coatings, (2) polymer/metal coatings, (3) ceramic/metal coatings, and (4) hybrid polymer, ceramic, and metal coatings. The coater is fully automated and incorporates polymer evaporation and extrusion heads, high-rate magnetron sputtering cathodes, and e-beam evaporation sources. Polymer electrolytes are deposited by extrusion techniques. Flexible plastic, metal, and ceramic substrates can be coated using roll-to-roll or closed-loop configurations. Examples of multilayer optical coatings demonstrated to date are solar reflectors, heat mirrors, Fabry-Perot filters, and alpha particle sensors. Nonoptical coatings include multilayer magnetic metal/ceramic and lamellar composites.

  13. Large Area Vacuum Deposited Coatings

    SciTech Connect

    Martin, Peter M.

    2003-04-30

    It's easy to make the myriad of types of large area and decorative coatings for granted. We probably don't even think about most of them; the low-e and heat mirror coatings on our windows and car windows, the mirrors in displays, antireflection coatings on windows and displays, protective coatings on aircraft windows, heater coatings on windshields and aircraft windows, solar reflectors, thin film solar cells, telescope mirrors, Hubble mirrors, transparent conductive coatings, and the list goes on. All these products require large deposition systems and chambers. Also, don't forget that large batches of small substrates or parts are coated in large chambers. In order to be cost effective hundreds of ophthalmic lenses, automobile reflectors, display screens, lamp reflectors, cell phone windows, laser reflectors, DWDM filters, are coated in batches.

  14. Protective coating for ceramic materials

    NASA Technical Reports Server (NTRS)

    Kourtides, Demetrius A. (Inventor); Churchward, Rex A. (Inventor); Lowe, David M. (Inventor)

    1994-01-01

    A protective coating for ceramic materials such as those made of silicon carbide, aluminum oxide, zirconium oxide, aluminoborosilicate and silicon dioxide, and a thermal control structure comprising a ceramic material having coated thereon the protective coating. The protective coating contains, in admixture, silicon dioxide powder, colloidal silicon dioxide, water, and one or more emittance agents selected from silicon tetraboride, silicon hexaboride, silicon carbide, molybdenum disilicide, tungsten disilicide and zirconium diboride. In another aspect, the protective coating is coated on a flexible ceramic fabric which is the outer cover of a composite insulation. In yet another aspect, a metallic foil is bonded to the outer surface of a ceramic fabric outer cover of a composite insulation via the protective coating. A primary application of this invention is as a protective coating for ceramic materials used in a heat shield for space vehicles subjected to very high aero-convective heating environments.

  15. water-soluble fluorocarbon coating

    NASA Technical Reports Server (NTRS)

    Nanelli, P.

    1979-01-01

    Water-soluble fluorocarbon proves durable nonpolluting coating for variety of substrates. Coatings can be used on metals, masonry, textiles, paper, and glass, and have superior hardness and flexibility, strong resistance to chemicals fire, and weather.

  16. Thermal barrier coating for alloy systems

    DOEpatents

    Seals, Roland D.; White, Rickey L.; Dinwiddie, Ralph B.

    2000-01-01

    An alloy substrate is protected by a thermal barrier coating formed from a layer of metallic bond coat and a top coat formed from generally hollow ceramic particles dispersed in a matrix bonded to the bond coat.

  17. Effect of concentration of sodium silicate solution in the synthesis of silica-coated magnetite nanoparticles by ultrasonication

    NASA Astrophysics Data System (ADS)

    Fajaroh, Fauziatul; Sumari, Nazriati

    2016-02-01

    An ex-situ silica coating of magnetite nanoparticles synthesized electrochemically had been successfully carried out by ultrasonication. An aqueous solution of sodium silicate had been used as silica source.The Si-O-Si, Si-O and Fe-O-Si bonds on the surface of the silica-coated magnetite had been successfully identified using FTIR. Reduction in particle size due to the influence of ultrasound was studied using SEM. Enhancement in the specific surface area of the particles due to the silica coating and reduction in particle size was learned through BET analysis. The Characters of the resulting silica-coated magnetite were influenced by the concentration of sodium silicate solution. The greater the concentration of sodium silicate solution, the smaller the particle crystallinity and the larger the particles surface area was produced. The resulting silica-coated magnetite has a surface area of 38.171 to 67.993 m2/g, otherwise the non-coated particles only has a surface area of 27.894 m2/g. This silica-coated magnetite nanoparticles has more potent as an adsorbent than that of the bare magnetite. Besides that, the presence of silanol groups on its surface makes an opportunity for further functionalization needed for some applications.

  18. Roebel assembled coated conductor cables (RACC): Ac-Losses and current carrying potential

    NASA Astrophysics Data System (ADS)

    Frank, A.; Heller, R.; Goldacker, W.; Kling, A.; Schmidt, C.

    2008-02-01

    Low ac-loss HTS cables for transport currents well above 1 kA are required for application in transformers and generators and are taken into consideration for future generations of fusion reactor coils. Coated conductors (CC) are suitable candidates for high field application at an operation temperature in the range 50-77 K. Ac-field applications require cables with low ac-losses and hence twisting of the individual strands. We solved this problem using the Roebel technique. Short lengths of Roebel bar cables were prepared from industrial DyBCO and YBCO-CC. Meander shaped tapes of 4 or 5 mm width with twist pitches of 123 or 127 mm were cut from the 10 or 12 mm wide CC tapes using a specially designed tool. Eleven or twelve of these strands were assembled to a cable. The electrical and mechanical connection of the tapes was achieved using a silver powder filled conductive epoxy resin. Ac-losses of a short sample in an external ac-field were measured as a function of frequency and field amplitude as well as the coupling current decay time constant. We discuss the results in terms of available theories and compare measured time constants in transverse field with measured coupling losses. Finally the potential of this cable type for ac-use is discussed with respect to ac-losses and current carrying capability.

  19. Coated article and method of making

    NASA Technical Reports Server (NTRS)

    Wang, Hongyu (Inventor); Lee, Kang Neung (Inventor)

    2002-01-01

    An article includes a silicon-containing substrate and a modified mullite coating. The modified mullite coating comprises mullite and a modifier component that reduces cracks in the modified mullite coating. The article can further comprise a thermal barrier coating applied to the modified mullite coating. The modified mullite coating functions as a bond coating between the external environmental/thermal barrier coating and the silicon-containing substrate. In a method of forming an article, a silicon-containing substrate is formed and a modified mullite coating is applied. The modified mullite coating comprises mullite and a modifier component that reduces cracks in the modified mullite coating.

  20. Coated article and method of making

    NASA Technical Reports Server (NTRS)

    Wang, Hongyu (Inventor); Lee, Kang Neung (Inventor)

    2003-01-01

    An article includes a silicon-containing substrate and a modified mullite coating. The modified mullite coating comprises mullite and a modifier component that reduces cracks in the modified mullite coating. The article can further comprise a thermal barrier coating applied to the modified mullite coating. The modified mullite coating functions as a bond coating between the external environmental/thermal barrier coating and the silicon-containing substrate. In a method of forming an article, a silicon-containing substrate is formed and a modified mullite coating is applied. The modified mullite coating comprises mullite and a modifier component that reduces cracks in the modified mullite coating.