The development of heat recovery equipment from conception to commercialisation

A comprehensive survey of industrial sites and heat recovery products revealed gaps between equipment that was required and that which was available. Two heat recovery products were developed to fill those gaps: a gas-to-gas modular heat recovery unit; a gas-to-liquid exhaust gas heat exchanger. The former provided an entire heat recovery system in one unit. It was specifically designed to overcome the problems associated with existing component system of large design commitment, extensive installation and incompatibility between parts. The unit was intended to recover heat from multiple waste gas sources and, in particular, from baking ovens. A survey of the baking industry defined typical waste gas temperatures and flow rates, around which the unit was designed. The second unit was designed to recover heat from the exhaust gases of small diesel engines. The developed unit differed from existing designs by having a negligible effect on engine performance. In marketing terms these products are conceptual opposites. The first, a 'product-push' product generated from site and product surveys, required marketing following design. The second, a 'market-pull' product, resulted from a specific user need; this had a captive market and did not require marketing. Here marketing was replaced by commercial aspects including the protection of ideas, contracting, tendering and insurance requirements. These two product development routes are compared and contrasted. As a general conclusion this work suggests that it can be beneficial for small companies (as was the sponsor of this project) to undertake projects of the market-pull type. Generally they have a higher probability of success and are less capital intensive than their product-push counterparts. Development revealed shortcomings in three other fields: British Standards governing heat exchangers; financial assessment of energy saving schemes; degree day procedure of calculating energy savings. Methods are proposed to overcome these shortcomings.

Pre-conception care : current practice and methods of provision

This thesis examines the present provisions for pre-conception care and the views of the providers of services. Pre-conception care is seen by some clinicians and health educators as a means of making any necessary changes in life style, corrections to imbalances in the nutritional status of the prospective mother (and father) and the assessment of any medical problems, thus maximizing the likelihood of the normal development of the baby. Pre-conception care may be described as a service to bridge the gap between the family planning clinic and the first ante-natal booking appointment. There were three separate foci for the empirical research - the Foresight organisation (a charity which has pioneered pre-conception care in Britain); the pre-conception care clinic at the West London Hospital, Hammersmith; and the West Midlands Regional Health Authority. The six main sources of data were: twenty five clinicians operating Foresight pre-conception clinics, couples attending pre-conception clinics, committee members of the Foresight organisation, staff of the West London Hospital pre-conception clinic, Hammersmith, District Health Education Officers working in the West Midlands Regional Health Authority and the members of the Ante-Natal Care Action Group, a sub-group of the Regional Health Advisory Group on Health Promotion and Preventive Medicine. A range of research methods were adopted. These were as follows: questionnaires and report forms used in co-operation with the Foresight clinicians, interviews, participant observation discussions and informal meetings and, finally, literature and official documentation. The research findings illustrated that pre-conception care services provided at the predominantly private Foresight clinics were of a rather `ad hoc' nature. The type of provision varied considerably and clearly reflected the views held by its providers. The protocol which had been developed to assist in the standardization of results was not followed by the clinicians. The pre-conception service provided at the West London Hospital shared some similarities in its approach with the Foresight provision; a major difference was that it did not advocate the use of routine hair trace metal analysis. Interviews with District Health Education Officers and with members of the Ante Natal Care Action Group revealed a tentative and cautious approach to pre-conception care generally and to the Foresight approach in particular. The thesis concludes with a consideration of the future of pre-conception care and the prospects for the establishment of a comprehensive pre-conception care service.

Compression spectrale dans les fibres optiques en présence de dispersion normale

Nous étudions numériquement le phénomène de compression spectrale se déroulant dans une fibre optique à dispersion normale. Les conditions conduisant à une impulsion en quasi-limite de Fourier sont déterminées et nous montrons que loin de dégrader les performances, la présence de dispersion normale permet une amélioration significative des résultats.