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Article
Publication date: 1 March 2002

M. Al‐Odat, M.A. Al‐Nimr and M. Hamdan

The thermal stability of superconductor is numerically investigated under the effect of a two‐dimensional hyperbolic heat conduction model. Two types of superconductor

Abstract

The thermal stability of superconductor is numerically investigated under the effect of a two‐dimensional hyperbolic heat conduction model. Two types of superconductor wires are considered, Types II and I. The thermal stability of superconductor wires under the effect of different design, geometrical and operating conditions is studied. The Effect of the time rate of change of the disturbance and the disturbance duration time is investigated. Generally, it is found that wave model predicts a wider stability region as compared to the predictions of the classical diffusion model.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 12 no. 2
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 17 July 2018

H.T. Rahal, A.M. Abdel-Gaber, R. Awad and B.A. Abdel-Naby

The paper aims to examine the inhibition effect of NiO nanoparticles and the influence of liquid nitrogen immersion on the corrosion behavior of (NiO)x(Bi1.6 Pb0.4)Sr2Ca2Cu…

Abstract

Purpose

The paper aims to examine the inhibition effect of NiO nanoparticles and the influence of liquid nitrogen immersion on the corrosion behavior of (NiO)x(Bi1.6 Pb0.4)Sr2Ca2Cu3O10-δ and (NiO)x (Bi, Pb 2223), where x = 0.00 and 0.05 Wt.% phase superconductor in 0.1 M Na2SO4 at 30°C.

Design/methodology/approach

This study was done using open-circuit potential electrochemical impedance spectroscopy, potentiodynamic polarization curves and chronoamperometry measurements.

Findings

Potentiodynamic polarization technique showed that NiO nanoparticles suppress both the anodic and cathodic parts of the polarization curves of (NiO)x(Bi, Pb)-2223 superconductor in 0.1 M Na2SO4 solution. A significant enhancement in the corrosion resistance of the prepared superconductors is observed on immersing them in liquid nitrogen. This is owing to the fact that immersion in liquid nitrogen increases the volume contraction of the superconductor matrix, causing the shrinkage of the pores and voids present in the samples and thus reducing the active surface area for the dissolution of (NiO)x(Bi, Pb)-2223 superconductor matrix.

Originality/value

This paper fulfills the need to investigate the corrosion behavior of superconductors and the influence of liquid nitrogen immersion on such behavior.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 June 2000

Michael Fosmire

The phenomenon of superconductivity has been studied for 90 years, with the latest surge in popularity occurring in the late 1980s, when high‐temperature superconductors

Abstract

The phenomenon of superconductivity has been studied for 90 years, with the latest surge in popularity occurring in the late 1980s, when high‐temperature superconductors were first created. In this time much progress has been made to create commercially viable applications of the technology and understand the theory behind the phenomenon. Furthermore, at a time when national science policy was undergoing close scrutiny, the high‐temperature superconductor boom served as a high‐profile case study of the role of government in spurring the acceptance of new technologies. This bibliography provides resources that chronicle the technological and scientific developments in the field since its discovery and the policy decisions and issues that governments and society made when faced with a possible scientific revolution.

Details

Reference Services Review, vol. 28 no. 2
Type: Research Article
ISSN: 0090-7324

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Article
Publication date: 1 March 2001

T.A. Coombs, A.M. Campbell, A. Murphy and M. Emmens

A method is presented for calculating the critical state profiles in bulk superconductors. It can be used for asymmetric samples in non‐uniform fields and for transport…

Abstract

A method is presented for calculating the critical state profiles in bulk superconductors. It can be used for asymmetric samples in non‐uniform fields and for transport currents as well as magnetisation. In this technique the sample starts with no current flowing. Elements carrying Jc are then inserted at the point of maximum vector potential and the field recalculated. The process is continued until the external field is screened from the interior. As an example the force on a magnet above a cylindrical puck is calculated.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 June 2000

George K. Chako

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or…

Abstract

Briefly reviews previous literature by the author before presenting an original 12 step system integration protocol designed to ensure the success of companies or countries in their efforts to develop and market new products. Looks at the issues from different strategic levels such as corporate, international, military and economic. Presents 31 case studies, including the success of Japan in microchips to the failure of Xerox to sell its invention of the Alto personal computer 3 years before Apple: from the success in DNA and Superconductor research to the success of Sunbeam in inventing and marketing food processors: and from the daring invention and production of atomic energy for survival to the successes of sewing machine inventor Howe in co‐operating on patents to compete in markets. Includes 306 questions and answers in order to qualify concepts introduced.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 12 no. 2/3
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 8 March 2011

Mark D. Ainslie, Tim J. Flack, Zhiyong Hong and Tim A. Coombs

The purpose of the paper is to provide a comparison of first‐ and second‐order two dimensional finite element models for evaluating the electromagnetic properties and…

Abstract

Purpose

The purpose of the paper is to provide a comparison of first‐ and second‐order two dimensional finite element models for evaluating the electromagnetic properties and calculating AC loss in high‐temperature superconductor (HTS) coated conductors.

Design/methodology/approach

The models are based on the two‐dimensional (2D) H formulation, which is based on directly solving the magnetic field components in 2D. Two models – one with a minimum symmetric triangular mesh and one with a single‐layer square mesh – are compared based on different types of mesh elements: first‐order (Lagrange – linear) and second‐order (Lagrange – quadratic) mesh elements, and edge elements.

Findings

The number and type of mesh elements are critically important to obtain the minimum level of discretization to achieve accurate results. Artificially increasing the superconductor layer and choosing a minimum symmetric mesh with triangular edge elements can provide a sufficiently accurate estimation of the hysteretic superconductor loss for a transport current.

Originality/value

This paper describes how the selection of mesh type and number of elements affects the computation speed and convergence properties of the finite element model using two different types of meshing. It offers an insight into the different factors modelers must consider when modeling HTS coated conductors and the methods that may be applied when extending the model to complex device geometries, such as wound coils.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 June 2002

George K. Chacko

Develops an original 12‐step management of technology protocol and applies it to 51 applications which range from Du Pont’s failure in Nylon to the Single Online Trade…

Abstract

Develops an original 12‐step management of technology protocol and applies it to 51 applications which range from Du Pont’s failure in Nylon to the Single Online Trade Exchange for Auto Parts procurement by GM, Ford, Daimler‐Chrysler and Renault‐Nissan. Provides many case studies with regards to the adoption of technology and describes seven chief technology officer characteristics. Discusses common errors when companies invest in technology and considers the probabilities of success. Provides 175 questions and answers to reinforce the concepts introduced. States that this substantial journal is aimed primarily at the present and potential chief technology officer to assist their survival and success in national and international markets.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 14 no. 2/3
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 26 November 2018

Krzysztof Dominik Pomorski, Hiroyuki Akaike, Akira Fujimaki and Krzysztof Rusek

The lack of reliable and scalable superconducting random access memory (RAM) cells is the main obstacle for full implementation of superconducting rapid single flux…

Abstract

Purpose

The lack of reliable and scalable superconducting random access memory (RAM) cells is the main obstacle for full implementation of superconducting rapid single flux quantum(RSFQ) computers. This work points the methodology and the structures that shall be used in future implementation of RSFQ RAM.

Design/methodology/approach

A new design for RAM using two ferromagnetic strips in proximity to the superconductor in a RSFQ computer is presented (1). The concept of using a RAM RSFQ cell as a tuneable superconducting qubit is also explored.

Findings

Two basic architectures for superconducting RAM cells were developed with integration schemes in two dimensions.

Research limitations/implications

The proposed RAM cells as depicted in Figures 7 and 16 offer smaller size and greater 3 scalability in comparison to other suggested schemes (4), (3), (2), (5).

Practical implications

Currently, the main obstacle in implementation of RSQF computer is lack of reliable RAM cell. RSQF computer shall have potential to take a large fraction of classical supercomputers, as it consumes much less power.

Social implications

Computation power shall be cheaper when one uses RSQF computers for big data and computational centres. It is a matter of some time.

Originality/value

The publication presents the new design of superconducting RAM cell for use in RSQF computer. The numerical relaxation method is used to solve biharmonic Ginzburg–Landau equation. The analytic approach as a solution of a specified problem is given.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 December 1998

Gábor Harsányi, Yanqing Liu and W. Kinzy Jones

Specially formulated frit materials have been applied in thick film superconductors similar to the standard thick film materials in order to achieve processing parameters…

Abstract

Specially formulated frit materials have been applied in thick film superconductors similar to the standard thick film materials in order to achieve processing parameters closely compatible with conventional thick film technology and alumina substrates. The applied frits have improved the adhesion and superconductor properties at the same time due to a superconductor bridge formation between the grains. Both YBCO and BSCCO systems have been analyzed. The results are promising.

Details

Microelectronics International, vol. 15 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 January 1994

Antoni Cieśla and Andrzej Matras

In the paper a field model of superconductor matrix separator is shortly presented. It allows to determine the electromagnetic induction voltage value in magnet winding…

Abstract

In the paper a field model of superconductor matrix separator is shortly presented. It allows to determine the electromagnetic induction voltage value in magnet winding during matrix removing out of the field. The case of matrix removing taking place with various as well as constant velocity will is regarded. The last concept allowed to determine optimum velocity function regarding minimal removing matrix time satisfying the condition of superconductor winding stable work.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 13 no. 1
Type: Research Article
ISSN: 0332-1649

1 – 10 of 266