Theoretical investigations are made on the sound radiation from a system consisting of a vibrating wall and a layer of porous material mounted on the wall. The wall has an arbitrary amplitude distribution and the material is in the same motion as the wall. The radiation field is obtained from the solution of a boundary value problem in the whole space including the inside of the material and free space in which the sound is radiated. The “generalized efficiency coefficient of radiation” is proposed. By using it, simple formulas for the radiation pattern and the radiation power are obtained.
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The impact of the energy crisis of 1973 has created the impetus for technological innovations and process improvements to reduce the consumption of energy and labour. The cost of production in the iron and steel industry is to a great extent affected by the consumption of both energy and labour. Therefore, the reduction of the consumption of these two vital components is the key to an efficient operation.In this context, Funabashi Steel Works has made significant progress in developing the most efficient and economical process for the electric arc furnace and continuous casting operations. The essence of this process is that melting, casting and rolling operations are continuous, without int. erruption between operations. The advantages of this process are:(1) energy saving, resource saving, manpower saving and reduction of cost of production;(2) possibility of charging hot billets to reheating furnaces and thereby saving fuel consumption;(3) high level of efficiency of operations and productivity gains.Detailed in this paper are the important phases of rapid melting which permitted continuous longsequence casting. Techniques adopted for achieving a record production of more than 110 continuously cast heats are highlighted. Résumé L'impact de la crise énergétique de 1973 a donné l'élan aux innovations technologiques et aux améliorations de procédés afin de réduire la consommation de l' énergie et de la maind' oeuvre. Les coûts de production dans l'industrie du fer et de l'acier sont affectés dans une large mesure par la consommation de l' énergie et le coût de la main-d'oeuvre. Dès lors, diminution de ces deux composantes vitales affecte directement l'efficacité des operations.Dans ce contexte, Funabashi Steel Works a fait un progrès significatif en développant un procédé efficace et économique au four à arc électrique et à la coulée continue.L'idée maitresse de ce procédé est la continuité des opérations de fusion, de coulée et de laminage.Les avantages de ce procédé sont:1° Economie d'énergie, economie des ressources, economie de main-d'oeuvre et réduction du cout de production.2° Possibilité de chargement des billettes chaudes aux fours de recuit et économie sur la consommation de combustible de cette façon.3° Efficacite élevée des opérations et gain de productivité.On présente les détails qui permettent d'obtenir une fusion rap ide et des séquences prolongées à la coulée continue. On explique aussi les techniques adoptées pour réaliser une production record de plus de 110 coulées, en continu.
The study described in this report targets total systems for treating waste and shows a method for performing a comprehensive qualitative evaluation of a total system from initial waste generation to final waste treatment over its life cycle. In this report, "waste" as an object of treatment excludes raw sewage and industrial waste. The items evaluated are the environment loads (CO_2, NO_X, and SO_X discharges associated with each of the processes of waste generation, collection, transport, intermediate treatment, and final treatment), and amounts of waste recycled and waste disposed as landfill, and the costs.
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