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The purpose of this paper is to propose a novel type of switched flux PM machines with two separate stators.

2D-FEA is employed to analyze the electromagnetic performance of the proposed machines. Moreover, the results are validated by experiments.

The proposed machine has higher torque density, less unbalanced magnetic force on the modulating steel piece and uses less PM volume.

The proposed machine is a low-cost novel topology with different rotor pole combinations.

THE FUEL SYSTEM is a simple state‐of‐the‐art system which is designed to minimise system maintenance and provide a very high probability of mission success. It requires no fuel management or manipulation of system controls during a normal mission. It is designed to use MIL‐J‐5624G, grades JP‐4 and JP‐5 turbine fuel.

The aim of this paper was to review the knowledge and practice‐related literature, as well as to develop a theoretical framework that functions like a sorting device, in order to improve our understanding about how theories are turned into practice.

This is a theoretical paper that discusses the relationships between practice and knowledge using practice‐based lenses.

This paper discusses the relationships between diverse forms of knowledge and practice, and it elaborates the cognitive mechanisms used to know how to shift from the inside to the outside view, and vice versa.

By organising a wide range of knowledge‐ and practice‐related concepts into meaningful categories, this paper contributes to overcoming the use of the concepts of knowledge and practice as universal.

By recognising the implicit epistemological stance associated with the diverse theories and concepts, the framework may be useful in selecting the most suitable practice concepts and theories for specific situations, especially since they are not universal and are usually developed with different purposes.

The proposed framework contributes to improve our understanding about how theories are turned into practice.

The background of missile costs is discussed. Missiles are new and very costly. Developments in this field have been subjected to political vicissitudes which have often upset long‐term developments. Missile technology is on the frontier of science and there is no background of knowledge to draw on; much basic and expensive research is required. Missile engineering models are complex in detail and assembly, and therefore costly, and constant change occurs while making and testing the model. The complexity and functional requirements of missile parts are running a parallel race with the machines and processes being developed to fabricate the materials required. The usually small runs required in missile production again add to costs. Imposed on all these activities is the requirement that reliability of near 100 per cent is needed and in no case can reliability be allowed to be secondary to cost. The inflight life and shelf conditions for a missile are usually fairly well established and 100 per cent reliability for a short operating life with a long shelf life are the real requirements. There is a considerable tendency to overdesign for reliability. Some costly features of design such as finest finish, closest tolerances and highest strength are carried over by habit from aircraft design and are not always required in missiles. Having examined some causes of high costs, a programme for cost reduction is set out. Costs can be reduced by: (i) earlier freezing of designs making changes only in groups of several changes at wider intervals, (ii) making a more realistic approach to reliability designs, (iii) selecting tolerances in a more analytical manner according to individual needs, (iv) selecting materials on the basis of actual design requirements instead of using the very best materials available even when the short life makes them unnecessary, (v) avoiding tool‐room methods in production engineering, (vi) setting work standards on as many operations as possible and enforcing them to the greatest degree possible, (vii) selecting the best type of workers to make the transition from development models to production missiles as smooth as possible, and (viii) setting up rigid systems and parts designation procedures for handling production parts. Finally, methods of organizing research and development and production for bridging the gap between engineering design and production are proposed.

THE use of the variable‐pitch airscrew has to‐day become commonplace. Its wide application permits certain facts derived from experience to be postulated and leads to new development problems.

Periodic inspection of bridge cables is essential, and cable-climbing robots can replace human workers to perform risky tasks and improve inspection efficiency. However, cable inspection robots often fail to surmount large obstacles and cable clamps. The purpose of this paper is to develop a practical cable inspection robot with stronger obstacle-surmounting performance and circumferential rotation capability.

A cable inspection robot with novel elastic suspension mechanisms and circumferential rotation mechanisms is designed and proposed in this study. The supporting force and spring deformation of the elastic suspension are investigated and calculated. Dynamic analysis of obstacle surmounting and circumferential rotation is performed. Experiments are conducted on vertical and inclined cables to test the obstacle-surmounting performance and cable-clamp passing of the robot. The practicality of the robot is then verified in field tests.

With its elastic suspension mechanisms, the cable inspection robot can carry a 12.4 kg payload and stably climb a vertical cable. The maximum heights of obstacles surmounted by the driving wheels and the passive wheels of the robot are 15 mm and 13 mm, respectively. Equipped with circumferential rotation mechanisms, the robot can flexibly rotate and successfully pass cable clamps.

The novel elastic suspension mechanism and circumferential rotation mechanism improve the performance of the cable inspection robot and solve the problem of surmounting obstacles and cable clamps. Application of the robot can promote the automation of bridge cable inspection.

Smiths Industries is to supply the head‐up display system for the Sea Harrier. The company will design, develop and make the electronic head‐up display and weapon aiming computer system for the latest version of the HS Harrier which will operate from Royal Navy ships.

THE Trident IE fuel system, designed to operate on cither kerosene or JP.4, has a straightforward layout with few controls. Five integral tanks (FIG. 1), comprising four in the wings and one in the centre section, give a total of 5,880 Imp. gall, of which 2,000 Imp. gall, are contained in the centre tank. (Total fuel capacity of the Trident 1C is 4,960 Imp. gall, with 1,160 Imp. gall, in the centre tank.) Each wing inner tank has slightly more than twice the capacity of the outer.

FOR a number of years now it has been evident that a successor to the well‐tried Vickers Viscount and Convoir 240/340/440 series was required. However, the big problem was to design an aircraft such that its economics and passengerappealweresub‐stantially better than the machines it would ultimately replace. Other important factors which had to be con‐sidered were improved reliability, easier and cheaper maintenance, higher standards of safety and means of reducing ramp times. Furthermore, the difficult choice of passenger capacity and cruising speed had to be made. Probably the easiest decision was to employ the twin‐engine configuration with the power plants placed in the now familiar rear position, one on cither side of the fuselage.

NORTH Sea Aerial & General Transport, Ltd., a subsidiary of the Blackburn Aeroplane & Motor Co., Ltd., which operates a Royal Air Force Reserve Flying School at Brough, E. Yorks, has recently built an engine test room adjoining the engine repair shop and has installed a very ingenious engine test bed. Mr. T. Bancroft, Chief Engineer of the Flying School, is responsible for the design of the bed. With the exception of the brake gear, cooling fan, starting motor, switch gear and instruments the whole of the installation has been constructed by the Company.