Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 14 of 14 for “"trapped field"”.
-
Investigation of High-Temperature Superconducting Trapped Field Magnets in a Superconducting Motor
… investigation of magnetisation and cross-field demagnetisation in high-temperature superconducting (HTS) trapped field stacks (TFSs) within a partially superconducting machine, employing a finite element method (FEM)-based modelling approach. The key innovations presented in this work are: …
-
Stacks of high temperature superconducting tape as trapped field magnets for energy applications
… using superconducting materials. In particular, trapped field superconducting magnets, where the field is generated by a circulating persistent current in the sample, can create magnetic fields an order of magnitude higher than possible using conventional ferromagnets, thus increasing the power …
-
Development of a Bulk Superconducting Magnet for Benchtop Nuclear Magnetic Resonance
… for the generation of the strong polarising fields required for nuclear magnetic resonance (NMR) when utilised as trapped field magnets (TFMs). To date, these stacks have been magnetised by the quasi-static field cooled magnetisation (FCM) technique within NMR-grade fields, requiring access …
-
The microstructure, mechanical and superconducting properties of (RE)BCO bulk single grains
… was calculated from the maximum measured trapped field in 22 different sized YBCO bulk superconductors. A correlation between porosity and *J<sub>c</sub>* was established by evaluating the experimental results statistically using Spearman’s correlation coefficient. The direct correlation …
-
The mechanical properties of Y-Ba-Cu-O and Gd-Ba-Cu-O/Ag bulk superconductor magnets
… due to their ability to trap magnetic fields in excess of 17 T, which is an order of magnitude greater than what can be achieved with conventional iron-based permanent magnets. One of the major obstacles to the use of (RE)BCO trapped field magnets is their poor mechanical properties, as …
-
Advanced Numerical Modelling of Bulk Superconductor Magnetisation
… of a material, and the expulsion of magnetic fields from within its volume, below a certain (critical) temperature. Superconductors can be subdivided into two classifications; type-I, or type-II, with the latter exhibiting a ‘mixed-state’ of superconductivity across their volume. Through …
-
Tailoring Superconductor and SOFC Structures for Power Applications
… design, the Roebel cable, can be used to make trapped field magnets that produce a uniform magnetic field profile over a large area. This trapped field magnet work is extended to study self-supporting soldered stacks of HTS tape that demonstrate unprecedented magnetic field uniformity. Section …
-
Improvement in the Growth and Superconducting Properties of Bulk Sm-Ba-Cu-O Superconductors Fabricated in Air
… at relatively high applied magnetic field and higher irreversibility field than that of the more established YBCO. The aim of this study is to investigate and overcome the obstacles in fabricating SmBCO bulk superconductors in air, to further improve their superconducting properties …
-
Magnetisation of bulk superconductors for future light-weight electric motors
Bulk superconductors, in their capacity as trapped field magnets, offer a practical means of generating high magnetic fields in small volumes. This is desirable for applications in which portability is of primary concern. In particular, superconducting materials are seen as enablers leading towards …
-
Applications of Pulse-Magnetised Bulk Superconductors
Magnetic fields are used in a wide variety of scientific disciplines, especially those concerned with the macroscopic and microscopic examination of matter. Superconductors have proved to be the most economical form of generating magnetic fields when strong magnetic fields are required. In recent …
-
Determination of the possible role of arthropods as vectors for "Potomac Horse Fever" in equines
… rickettsial diseases. A series of laboratory and field studies were designed to examine the potential role of D. variabilis in the transmission of E. risticii. We first attempted to transmit E. risticii by feeding adult D. variabilis collected from an endemic farm on susceptible horses. Other …
-
Pulsed field magnetization of composite superconducting bulks for magnetic bearing applications
… rare-earth magnets are limited to a remanent field of 1.4 T, whereas superconducting materials such as YBCO in their bulk form have the extraordinary ability to trap magnetic fields an order of magnitude higher, whilst being very compact. This gives them the potential to increase efficiency …
-
Modelling and experimental studies of the magnetic properties of bulk high temperature superconductors
… the generation of relatively large magnetic fields by these materials for their potential use in a number of high field, 'quasi-permanent' magnet applications. Chapters I and 2 introduce bulk HTS based on their magnetic properties. More specifically, Chapter I describes the background for …
-
An investigation into high temperature superconducting flux pump technology with the circular type magnetic flux pump devices and YBaCuO films
… under different conditions, such as zero-field cooling (ZFC), field cooling (FC), delta-shape trapped field, etc. A simulation based on the H-formulation using FEM software revealed that, after application of the travelling wave, the current density distribution inside the round shape YBCO …