scholarly journals Improved flux pinning behavior in bulk YBCO achieved by nano-alumina addition

2008 ◽  
Vol 97 ◽  
pp. 012284 ◽  
Author(s):  
N Moutalibi ◽  
A M'chirgui
Keyword(s):  
Flux Pinning ◽  
Bulk Ybco ◽  
Nano Alumina ◽  
Alumina Addition

scholarly journals The Antifouling and Drag-Reduction Performance of Alumina Reinforced Polydimethylsiloxane Coatings Containing Phenylmethylsilicone Oil

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3067
Author(s):  
Qiang Yang ◽  
Zhanping Zhang ◽  
Yuhong Qi ◽  
Hongyang Zhang
Keyword(s):  
Elastic Modulus ◽  
Drag Reduction ◽  
Surface Deformation ◽  
Silicone Oil ◽  
Leaching Behavior ◽  
Nano Alumina ◽  
Fouling Release ◽  
Alumina Addition ◽  
Fouling Organisms ◽  
Addition Amount

Fouling-release coatings reinforced with micro-alumina and nano-alumina were prepared based on polydimethylsiloxane (PDMS) containing phenylmethylsilicone oil. The surface properties, mechanical properties, leaching behavior of silicone oil, anti-fouling and drag-reduction performance of the coating were studied. The results show that the addition of alumina can significantly improve the tensile strength, elastic modulus and Shore’s hardness of the coating. The adhesion experiments of marine bacteria and Navicula Tenera show that the addition of alumina can reduce the antifouling performance of the coating, which is related to the stripping mode of fouling organisms. The fouling organisms leave the coating surface by shearing, and the energy required for shearing is proportional to the elastic modulus of the coating. At 800–1400 rpm, the addition of alumina will reduce the drag reduction performance of the coating, which is related to the drag reduction mechanism of PDMS. PDMS counteracts part of the resistance by surface deformation. The larger the elastic modulus is, the more difficult the surface deformation is. The experiment of silicone oil leaching shows that the increase of alumina addition amount and the decrease of particle size will inhibit the leaching of silicone oil.

Influence of Irradiation-Induced Correlated and Random Disorder on Flux Pinning in Bulk YBCO Melt-Textured Samples

1997 ◽  
Vol 10 (5) ◽  
pp. 541-548 ◽  
Author(s):  
G. Ghigo ◽  
R. Gerbaldo ◽  
L. Gozzelino ◽  
E. Mezzetti ◽  
B. Minetti ◽  
...  
Keyword(s):  
Flux Pinning ◽  
Bulk Ybco ◽  
Random Disorder

Research on Inclusions in Low Alloy Steel Welds with Nano Alumina Addition

2012 ◽  
Vol 9 (9) ◽  
pp. 1533-1536 ◽  
Author(s):  
Cuixin Chen ◽  
Huifen Peng ◽  
Ran Liu ◽  
Yuanyuan Li ◽  
Pu Zhao
Keyword(s):  
Alloy Steel ◽  
Low Alloy Steel ◽  
Nano Alumina ◽  
Alumina Addition ◽  
Steel Welds

Interfacial studies in Nb3Sn superconductors

1991 ◽  
Vol 49 ◽  
pp. 590-591
Author(s):  
Ernest L. Hall ◽  
Lee E. Rumaner ◽  
Mark G. Benz
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Flux Pinning ◽  
Size Control ◽  
High Magnetic Fields ◽  
Type Ii ◽  
Reaction Interface ◽  
Liquid Diffusion ◽  
Type Ii Superconductor ◽  
Grain Size Control

The intermetallic compound Nb3Sn is a type-II superconductor of interest because it has high values of critical current density Jc in high magnetic fields. One method of forming this compound involves diffusion of Sn into Nb foil containing small amounts of Zr and O. In order to maintain high values of Jc, it is important to keep the grain size in the Nb3Sn as small as possible, since the grain boundaries act as flux-pinning sites. It has been known for many years that Zr and O were essential to grain size control in this process. In previous work, we have shown that (a) the Sn is transported to the Nb3Sn/Nb interface by liquid diffusion along grain boundaries; (b) the Zr and O form small ZrO2 particles in the Nb3Sn grains; and (c) many very small Nb3Sn grains nucleate from a single Nb grain at the reaction interface. In this paper we report the results of detailed studies of the Nb3Sn/Nb3Sn, Nb3Sn/Nb, and Nb3Sn/ZrO2 interfaces.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

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