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[en] Energy is needed to sustain the economy, health and welfare of nations. As a consequence of this, energy consumption figures are frequently used as an index of a nation's advancement. As a result of the global energy crisis, almost every nation has had to develop all its available energy resources and plan its future use of energy. The planners of national and international energy policies are however often faced with a problem of 'public acceptance' arising from the potential health and environmental impacts of developing energy resources. The public's desire to preserve the quality of man's health and his environment frequently results in opposition to many industrial innovations, including the generation and use of energy. Reliable, quantitative data and information are needed on the risks to health and the environment of different contemporary energy systems, to improve public understanding, and to serve as the basis from which national planners can choose between different energy supply options. With the exception of nuclear energy, even in technologically advanced countries little systematic research and development has been done on the quantitative assessment of the effects on health and the environment of the conventional energy sources. The need for this information has only been realized over the past decade as the climate and environment in many regions of the world has deteriorated with the unabated release of pollutants from factories and energy generating plants in particular. A number of countries have started national environmental health research programmes to monitor and regulate toxic emissions from industry and energy plants. Energy-related environmental health research has been supported and co-ordinated by various international organizations such as the International Atomic Energy Agency (IAEA), World Health Organization (WHO) and United Nations Environment Programme (UNEP). WHO has supported expert reviews on the potential health risks posed by chemical and physical pollutants
[en] A first chapter comments the content of the French national document (proposed in appendix) presented at the conference, proposes a brief overview of the French policy of development of new and renewable energies and of the action of France in international collaboration in the field of these energies. In the second part, it comments the content of a leaflet (proposed in appendix) of the industrial activity of France in the development of geothermal in high and low energy. The third part describes the French geothermal potential, and presents some examples in France. The two last chapters contains contributions to the Nairobi exhibition, and brief presentations of the situation of collaborative actions in several different countries
[en] This report proposes an inventory of knowledge in geothermal energy (high and low enthalpy) in 55 countries of the world concerned by this resource. For each country, a sheet briefly indicates currently exploited and potential fields, produced and foreseen powers, and some field characteristics (fluid nature, temperature, number of drilled wells), proposes a brief overview of the sector organization (indication of national bodies, and of foreign companies intervening in the country), and states some general remarks related to the local energy policy, and, in some cases, research orientations
[en] Sulphate-reducing and methanogenic bacteria are anaerobic micro-organisms which are notably archaic as far for their origin as for the nature of reactions occurring in their metabolism. They are present in soft waters and in marine sediments, and their ecological and economic roles are very important: anaerobic corrosion of some metals, decrease of cereal efficiency (rice, maize), microbial associations during the degradation of organic matter into methane, carbon dioxide and hydrogen sulphide (biomass processing). Thus, this research thesis reports the study of the structure-function relationships of some types of redox proteins present in these bacteria. After a bibliographical study on sulphate-reducing bacteria and on methanogenic bacteria (history and classification, metabolism, electron carriers), the author presents the studied organisms and their growth conditions, the preparation of a hydrophilic colloidal sulphur, dosage techniques, protein purification techniques, activity tests, and techniques of analysis of the protein primary structure. Results are then presented and discussed: purification and characterisation of different redox proteins from sulphate-reducing and methanogenic bacteria (cytochromes, ferredoxins and hydrogenases), function of different redox proteins from sulphate-reducing bacteria (cytochromes, ferredoxins and hydrogenases).
[fr]Les bacteries methanigenes effectuent la synthese du methane a partir d'un petit nombre de composes a un ou deux atomes de carbone. Avec les bacteries sulfato-reductrices, elles jouent un role preponderant dans les associations microbiennes conduisant a la degradation complete de la matiere organique en methane, gaz carbonique et hydrogene sulfure. Les bacteries sulfata-reductrices peuvent, a partir de l'oxydation de substrats organiques, recuperer de l'energie sous forme d'adenosine-triphosphate au cours du transfert des electrons vers les composes oxygenes du soufre. Les micro-organismes sulfato-reducteurs du genre Desulfovibrio contiennent un grand nombre de transporteurs d'electrons de faible poids moleculaire (rubredoxine, flavodoxine, ferredoxines, cytochromes) ainsi que de nombreuses reductases de haut poids moleculaire (hydrogenases, sulfite-reductase, pyruvate-deshydrogenase). Le systeme complexe de transfert des electrons des bacteries sulfato-reductrices du genre Desulfovibrio est a l'origine de recherches considerables dans le domaine des relations structure-fonction des differentes proteines constituant les chaines d'oxydo-reduction. Par contre, chez les bacteries methanigenes on a actuellement peu de connaissance sur les differentes etapes de la reduction du gaz carbonique en methane ainsi que sur la biochimie des transporteurs d'electrons impliques dans la methanogenese. L'intervention des hydrogenases et le metabolisme de l'hydrogene moleculaire sont etroitement associes dans trois domaines interessant aussi bien la recherche fondamentale qu'appliquee: les fermentations complexes de la biomasse, la fixation de l'azote moleculaire, la production d'hydrogene par biophotolyse de l'eau. Pour ameliorer le rendement de photoproduction de H2 par le systeme: chloroplastes, transporteurs d'electrons a bas potentiel d'oxydo-reduction et hydrogenases, il est necessaire de bien comprendre le fonctionnement des differentes proteines de transfert intervenant dans la biophotolyse de l'eau. Au cours de ce travail, nous nous sommes plus particulierement interesse aux relations structure-fonction de differents types de proteines d'oxydo-reduction: - hydrogenases periplasmiques isolees de Desulfovibrio gigas et Desulfovibrio vulgaris souche Hildenborough, - hydrogenase soluble d'une bacterie methanigene: Methanosarcina barkeri souche DSM 800, - ferredoxines de Desulfovibrio desulfuricans souche Norway 4, - cytochromes de type c mono ou pluri hemiques de Desulfovibrio.