Modeling of Transport Loss in Bi-2212 Round Wires: Effects of Local Defects and Non-uniformity

2021 ◽  
pp. 1-1
Author(s):  
Min Xu ◽  
Wei Chen ◽  
Boyang Shen ◽  
Qingbin Hao ◽  
Chengshan Li ◽  
...  
Keyword(s):  
Transport Loss ◽  
Local Defects

DIAGNOSING QUALITY OF FRICTION SYSTEMS OF MECHANISMS OF DEVICES

2019 ◽  
Vol 1 (7) ◽  
pp. 10-13
Author(s):  
D. Yu. Ershov ◽  
I. N. Lukyanenko ◽  
E. E. Aman
Keyword(s):  
Surface Defects ◽  
Diagnostic Methods ◽  
Design Parameters ◽  
Diagnostic Model ◽  
Mechanical Assemblies ◽  
Local Defects ◽  
Relationship Of ◽  
The Relationship ◽  
Production And Operation

The article shows the need to develop diagnostic methods for monitoring the quality of lubrication systems, which makes it possible to study the dynamic processes of contacting elements of the friction systems of instrument mechanisms, taking into account roughness parameters, the presence of local surface defects of elements and the bearing capacity of a lubricant. In the present article, a modern diagnostic model has been developed to control the quality of the processes of production and operation of friction systems of instrument assemblies. With the help of the developed model, it becomes possible to establish the relationship of diagnostic and design parameters of the mechanical system, as well as the appearance of possible local defects and lubricant state, which characterize the quality of friction systems used in many mechanical assemblies of the mechanisms of devices. The research results are shown in the form of nomograms to assess the defects of the elements of friction mechanisms of the mechanisms of the devices.

Mapping local defects of extended media using localized structures

2008 ◽  
Vol 93 (11) ◽  
pp. 111104 ◽  
Author(s):  
F. Pedaci ◽  
G. Tissoni ◽  
S. Barland ◽  
M. Giudici ◽  
J. Tredicce
Keyword(s):  
Localized Structures ◽  
Local Defects

scholarly journals Structure and Properties of Polyoxymethylene/Silver/Maleic Anhydride-Grafted Polyolefin Elastomer Ternary Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1954
Author(s):  
Yang Liu ◽  
Xun Zhang ◽  
Quanxin Gao ◽  
Hongliang Huang ◽  
Yongli Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Maleic Anhydride ◽  
Ag Nanoparticles ◽  
Decomposition Temperature ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Maximum Value ◽  
Polyolefin Elastomer ◽  
Local Defects

In the present study, silver (Ag) nanoparticles and maleic anhydride-grafted polyolefin elastomer (MAH-g-POE) were used as enhancement additives to improve the performance of the polyoxymethylene (POM) homopolymer. Specifically, the POM/Ag/MAH-g-POE ternary nanocomposites with varying Ag nanoparticles and MAH-g-POE contents were prepared by a melt mixing method. The effects of the additives on the microstructure, thermal stability, crystallization behavior, mechanical properties, and dynamic mechanical thermal properties of the ternary nanocomposites were studied. It was found that the MAH-g-POE played a role in the bridging of the Ag nanoparticles and POM matrix and improved the interfacial adhesion between the Ag nanoparticles and POM matrix, owing to the good compatibility between Ag/MAH-g-POE and the POM matrix. Moreover, it was found that the combined addition of Ag nanoparticles and MAH-g-POE significantly enhanced the thermal stability, crystallization properties, and mechanical properties of the POM/Ag/MAH-g-POE ternary nanocomposites. When the Ag/MAH-g-POE content was 1 wt.%, the tensile strength reached the maximum value of 54.78 MPa. In addition, when the Ag/MAH-g-POE content increased to 15wt.%, the elongation at break reached the maximum value of 64.02%. However, when the Ag/MAH-g-POE content further increased to 20 wt.%, the elongation at break decreased again, which could be attributed to the aggregation of excessive Ag nanoparticles forming local defects in the POM/Ag/MAH-g-POE ternary nanocomposites. Furthermore, when the Ag/MAH-g-POE content was 20 wt.%, the maximum decomposition temperature of POM/Ag/MAH-g-POE ternary nanocomposites was 398.22 °C, which was 71.39 °C higher than that of pure POM. However, compared with POM, the storage modulus of POM/Ag/MAH-g-POE ternary nanocomposites decreased with the Ag/MAH-g-POE content, because the MAH-g-POE elastomer could reduce the rigidity of POM.

A New Strategy for Detecting Gear Faults Using Denoising With the Orthogonal Discrete Wavelet Transform (ODWT)

1999 ◽  
Author(s):  
Sidi M. Berri ◽  
J. M. Klosner
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Power Transmission ◽  
Discrete Wavelet ◽  
Amplitude Noise ◽  
Transmission Pair ◽  
New Strategy ◽  
Band Pass ◽  
Local Defects ◽  
Low Amplitude

Abstract This paper investigates a new strategy for early detection of defects in a power transmission pair of spur gears. Sensitivity to local defects is enhanced by processing the signal as follows. The orthogonal discrete wavelet transform (ODWT) of the band-pass filtered averaged signal is first obtained. This is followed by thresholding in the wavelet domain, thereby removing the low amplitude noise contribution. The inverse wavelet transform then essentially reconstructs the component of the signal that is due to the defect. Experimental results demonstrate the efficiency of this procedure.

Frequency Dependence of AC Transport Loss in Bi-2223/Ag Tapes

1998 ◽  
pp. 731-738 ◽  
Author(s):  
Y. K. Huang ◽  
J. J. Rabbers ◽  
B. ten Haken ◽  
H. H. J. ten Kate
Keyword(s):  
Frequency Dependence ◽  
Transport Loss

Defected/decorated benzenoid/graphitic nanostructures

2008 ◽  
Vol 80 (7) ◽  
pp. 1399-1414 ◽  
Author(s):  
D. J. Klein
Keyword(s):  
Density Of States ◽  
Local Density ◽  
Valence Bond ◽  
Two Dimensions ◽  
Local Density Of States ◽  
Reliable Prediction ◽  
Vacancy Defects ◽  
Substitutional Defects ◽  
Local Defects ◽  
Property Characterization

Various decorations, functionalizations, or defects of conjugated benzenoid or graphitic networks are considered, with special attention to the case that the structures are possibly extended in one or two dimensions. This includes various polymers, their end structures, and defects of side groups or vacancies along the chain, strip, or nanotube. This approach further includes various boundary (or edge) structures on semi-infinite graphite, as well as various "quasi-local" defects in what is otherwise two-dimensionally infinite graphite, such defects encompassing vacancy defects, selected substitutional defects, and perhaps even dislocations and disclinations. There are many possible such nanostructures, but property characterization is ultimately desired. Attention is paid to consequent occurrences of defect-localized unpaired (or weakly paired) electrons, as formulated within a resonating valence bond (RVB) framework, especially as regards simple classically appealing theorems or rules. But a further molecular orbital (MO) view is developed. Note is made of associated modifications in the local density of states near the Fermi energy. Consonance of predictions from RVB and MO viewpoints is taken as an indicator of reliable prediction.

scholarly journals Analysis of AC Transport Loss in Conductor on Round Core Cables

2021 ◽  
Author(s):  
Jiabin Yang ◽  
Chao Li ◽  
Mengyuan Tian ◽  
Shuyu Liu ◽  
Boyang Shen ◽  
...  
Keyword(s):  
Eddy Current ◽  
Complex Geometry ◽  
Layer Structure ◽  
Single Layer ◽  
Element Model ◽  
Structure Design ◽  
Ac Loss ◽  
Shielding Effect ◽  
Transport Loss ◽  
Electro Magnetic

AbstractThe conductor on round core (CORC) cable wound with second-generation high-temperature superconducting (HTS) tapes is a promising cable candidate with superiority in current capacity and mechanical strength. The composing superconductors and the former are tightly assembled, resulting in a strong electro-magnetic interaction between them. Correspondingly, the AC loss is influenced by the cable structure. In this paper, a 3D finite-element model of the CORC cable is first built, and it includes the complex geometry, the angular dependence of critical current and the periodic settings. The modelling is verified by the measurements conducted for the transport loss of a two-layer CORC cable. Subsequently, the simulated results show that the primary transport loss shifts from the former to the superconductors as the current increases. Meanwhile, the loss exhibited in the outer layer is larger than that of the inner layer, which is caused by the shielding effect among layers and the former. This also leads to the current inhomogeneity in CORC cables. In contrast with the two-layer case, the simulated single-layer structure indicates stronger frequency dependence because the eddy current loss in the copper former is always dominant without the cancellation of the opposite-wound layers. The core eddy current of the single structure is denser on the outer surface. Finally, the AC transport losses among a straight HTS tape, a two-layer cable and a single-layer cable are compared. The two-layer structure is confirmed to minimise the loss, meaning an even-numbered arrangement makes better use of the cable space and superconducting materials. Having illustrated the electro-magnetic behaviour inside the CORC cable, this work is an essential reference for the structure design of CORC cables.

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