No description available.

No description available.

A small lathe has been modified to work under microprocessor control to enhance the facilities which the lathe offers and provide a wider operating range with relevant economic gains. The result of these modifications give better operating system characteristics. A system of electronic circuits have been developed, utilising the latest technology, to replace the pegboard with the associated obsolete electrical components. Software for the system includes control programmes for the implementation of the original pegboard operation and several sample machine code programmes are included, covering a wide spectrum of applications, including diagnostic testing of the control system. It is concluded that it is possible to carry out a low cost retrofit on existing machine tools to enhance their range of capabilities.

No description available.

No description available.

No description available.

Industrially developed countries are able to absorb modern techniques of science and technology quite readily; this is not the case for less-developed countries. Attempts made by developing countries have been ineffective due to factors not readily admitted. This thesis highlights the areas that need to be developed by under-developed countries, and covers economic, scientific and technological, and social aspects as well as technology transfer. Economic areas considered acknowledge that within any one country there should be proper procedures for planning economic and industrial projects (plant design) supported by efficient economic development strategy. Scientific and technological factors considered include the major areas that need to be developed in order to produce and/or deal with scientific and technological issues for the interest of the national development. Technology transfer areas considered include the necessity of building up a national body (system) responsible for dealing with activities and tasks of transferring foreign-made technology so that it can be employed effectively within the environment of the country. Social factors considered include the need to develop human resources which can be employed efficiently into the whole process of development, and particularly for the above proposed systems. Education and training are the major elements that ought to be tackled to produce skilled manpower and to overcome the social and cultural values and traditions that are inherited by the society. This thesis highlights the above areas in an attempt to plan and organise the development of science and technology, and their implementation into the development as a whole. Whilst recognising the problems of creating this sort of development in developing countries, the author considers the benefits to be obtained are much greater in the long run.

The technology of precision bending of tubes has recently increased in importance and is widely demanded for many industrial applications. However, whilst attention has been concentrated on automation and increasing the production rate of the bending machines, it seems that with one exception very little work has been done in order to understand and therefore fundamentally improve the bending process. A new development for the process of draw-bending of tubes, in which the supporting mandrel is axially vibrated at an ultrasonic frequency, has been perfected. A research programme was undertaken to study the mechanics of tube• bending under both vibratory and non-vibratory conditions. For this purpose, a conventional tube-bending machine was modified and equipped with an oscillatory system. Thin-walled mild steel tubes of different diameter to thickness ratios were bent to mean bend radii having various values from 1.5 to 2.0 times the tube diameter. It was found that the application of ultrasonic vibration reduces the process forces and that the force reduction increases with increasing the vibration amplitude. A reduction in the bending torque of up to 30 per cent was recorded and a reduction in the maximum tube-wall thinning of about 15 per cent was observed. The friction vector reversal mechanism as well as a reduction in friction account for the changes of the forces and the strains. Monitoring the mandrel friction during bending showed, in some cases, that the axial vibration reverses the mandrel .mean force from tension to compression and, thus, the mandrel is assisting the tube motion instead of resisting it. A theory has been proposed to describe the mechanics of deformation during draw-bending of tubes, which embodies the conditions of both "with" and "without" mandrel axial vibration. A theoretical analysis, based on the equilibrium of forces approach, has been developed in which the basic process parameters were taken into consideration. The stresses, the strains and the bending torque were calculated utilising this new solution, and a specially written computer programme was used to perform the computations. It was shown that the theory is in good agreement with the measured values of the strains under vibratory and non-vibratory conditions. Also, the predicted bending 'torque showed a similar trend to that recorded experimentally.

No description available.

The research, which was given the terms of reference, ITo cut the lead time for getting new products into volume production i , was sponsored by a company which develops and manufactures telecommunications equipment. The research described was based on studies made of the development of two processors which were designed to control telephone exchanges in the public network. It was shown that for each of these products, which were large electronic systems containing both hardware and software, most of their lead time was taken up with development. About half of this time was consumed by activities associated with redesign resulting from changes found to be necessary after the original design had been built. Analysing the causes of design changes showed the most significant to be Design Faults. The reasons why these predominated were investigated by seeking the collective opinion from design staff and their management using a questionnaire. Using the results from these studies to build upon the worki of other authors, a model of the development process of large hierarchical systems is derived. An important feature of this model is its representation of iterative loops due to design changes. In order to reduce the development time, two closely related philosophies are proposed: By spending more time at the early stages of development (detecting and remedying faults in the design) even greater savings can be made later on, The collective performance of the development organisation would be improved by increasing the amount and speed of feedback about that performance. A trial was performed to test these philosophies using readily available techniques for design verification. It showed that about an 11 per cent saving would be made on the development time and that the philosophies might be equally successfully applied to other products and techniques.