Control of the glass-liquid transition temperature in YBa2Cu3O7-x films

Magnetic field dependences of the glass-liquid transition temperature (Tg) were studied in YBa2Cu3O7−x films containing various types of nanoinclusions. The vortex configuration entangled or straight and pinning strength for each vortex are crucial to the behaviors of Tg. c-axis correlated pinning centers optimize these factors and achieve the upper limit of Tg, which is determined by loss of line tension of vortices, if they are elongated through a thickness of a sample. By optimizing pinning centers, critical temperature, and a matching field, a Tg value of 77 K can be obtained in YBa2Cu3O7−x in a magnetic field as high as 27 T

Association of glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS): a cross-sectional study

Background While survival of systemic lupus erythematosus (SLE) patients has improved substantially, problems remain in the management of their emotional health. Medium to high-dose glucocorticoid doses are known to worsen emotional health; the effect is unclear among patients receiving relatively low-dose glucocorticoids. This study aims to investigate the association between low glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS). Methods This cross-sectional study drew on data from SLE patients in 10 Japanese institutions. The participants were adult patients with SLE duration of >= 1 year who met LLDAS criteria at the study visit from April 2018 through September 2019. The exposure was the daily glucocorticoid dose (mg oral prednisolone). The outcome was the emotional health score of the lupus patient-reported outcome scale (range: 0 to 100). Multiple linear regression analysis was performed with adjustment for confounders including disease-related damage, activity, and psychotropic drug use. Results Of 192 patients enrolled, 175 were included in the analysis. Their characteristics were as follows: female, 89.7%; median age, 47 years (interquartile range (IQR): 37.0, 61.0). Median glucocorticoid dose was 4.0 mg (IQR 2.0, 5.0), and median emotional health score 79.2 (IQR 58.3, 91.7). Multiple linear regression analysis showed daily glucocorticoid doses to be associated with worse emotional health (beta coefficient = - 2.54 [95% confidence interval - 4.48 to - 0.60], P = 0.01). Conclusions Daily glucocorticoid doses were inversely associated with emotional health among SLE patients in LLDAS. Further studies are needed to determine whether glucocorticoid tapering leads to clinically significant improvements in emotional health

High critical current density YBa₂Cu₃O₇ coating on conductive Nb-doped SrTiO₃ and Ni double-buffered {100}〈001〉 textured pure Cu tape for low-cost coated conductors without generation of any insulative oxides at interfaces

For development of a low-cost superconducting wire operating at high-temperature, we propose a new approach using conductive rather than insulating buffer layers, combined with {100}〈001〉 textured pure Cu tape to form YBa₂Cu₃O₇ (YBCO)/Nb-doped SrTiO₃/Ni/Cu/stainless steel. The critical current density of the YBCO layer was 2.5 MA cm⁻² at 77 K in a magnetic self-field. We also confirmed that some current flowed into the Cu tape through the conductive buffer layers when the current exceeded the critical current of the YBCO layer, suggesting that the textured Cu tape worked not only as a biaxial template but also as a stabilizer layer

Fabrication of YBa2Cu3O7 Superconducting Film on {100}<001> Textured Cu Tape via Conductive Buffer Layers

This Paper was Originally Published in Japanese in J. Japan Inst. Met. Mater. 80 (2016) 428–433.Long-length coated conductors (CCs) have recently become commercially available, serving as a promising candidate for use in electric power applications. However, the material and manufacturing costs are high, which discourages their use in a wide range of commercially feasible products. REBa2Cu3O7 (REBCO; RE: Y or rare-earth elements) superconducting films with high critical current density (Jc) have been grown on cube-textured metal tapes to develop CCs for high temperature, high magnetic field ap buffered Ni-W tape. CCs become highly resistive when they are quenched; therefore, for reliable and safe application, it is necessary to attach low-resistivity metal layers, such as Cu and/or Ag, to the CCs to stabilize and protect them from damage due to quenching. Presently, insulative oxides are used for the buffer layers; thus, thick Ag and Cu layers are required to be deposited as stabilizer layers on the YBCO layer. However, the high material and process costs for obtaining the Ag and Cu layers are one of the major obstacles to achieving low-cost CCs. The use of conductive buffer layers instead of insulative reduces the cost of CCs. In this paper, we propose a new configuration for CCs: YBCO deposited on a conductive Sr(Ti0.95Nb0.05)O3 buffered Ni-electroplated {100} textured Cu and SUS316 lamination tape. Sr(Ti0.95Nb0.05)O3 was epitaxially grown on the Ni-electroplated {100} textured Cu tape, and its resistivity was as low as 2.5 mΩ-cm at 77 K. An excellent Jc of 2.6 × 106 A/cm2 was achieved at 77 K under a magnetic self-field for the YBCO/Sr(Ti0.95Nb0.05)O3/Ni/Cu/SUS316 tape. We believe that Sr(Ti0.95Nb0.05)O3 is a promising candidate for the conductive buffer layer material

Microstructures of YBa2Cu3Oy Layers Deposited on Conductive Layer-Buffered Metal Tapes

Proceedings of the 28th International Symposium on Superconductivity (ISS 2015) November 16-18, 2015, Tokyo, JapanREBa2Cu3Oy (REBCO; RE: rare-earth elements)-coated conductors (CCs) have high potential for use in superconducting devices. In particular, REBCO CCs are useful for superconducting devices working at relatively high temperatures near 77 K. The important issues in their applications are high performance, reliability and low cost. To date, sufficient performance for some applications has almost been achieved by considerable efforts. The establishment of the reliability of superconducting devices is under way at present. The issue of low cost must be resolved to realize the application of superconducting devices in the near future. Therefore, we have attempted several ways to reduce the cost of REBCO CCs. The coated conductors using a Nb-doped SrTiO3 buffer layer and Ni-plated Cu and stainless steel laminate metal tapes have recently been developed to eliminate the use of electric stabilization layers of Cu and Ag, which are expected to reduce the material cost. Good superconducting properties are obtained at 77 K. The critical current density (JC) at 77 K under a magnetic self-field is determined to be more than 2x106 A/cm2. The microstructures of the CCs are analyzed by transmission electron microscopy to obtain a much higher quality. By microscopic structure analysis, an overgrowth of the buffer layer is observed at a grain boundary of the metal substrate, which is one of the reasons for the high JC

Program Slicing on VHDL Descriptions and Its Applications

We propose applying program slicing to hardware description language VHDL; program slicing is a technique developed in the software engineering field, and it can extract all the sentences which have a certain dependence to a given sentence, and it can be utilized for analysis and modification of programs. Program slicing for hardware description languages should have a variety of applications in VLSI CAD, such as functional verification, test generation, designer assistance, and design synthesis. We show several examples of program slicing on VHDL descriptions, and address a list of related issues. 1 Introduction Hardware description languages (HDLs) are now being widely used as a tool for total system description, from low-level circuit descriptions to high-level abstract and conceptual descriptions. As design resources in the form of HDL descriptions are going to be accumulated, verification, maintenance and reuse of HDL descriptions will become an important issue. We propose apply..