Work carried out by engineers, research and design laboratories for the treatment and purification of water, treatment of industrial and household waste, treatment of sludge and ashes, re-use of industrial and household waste, of sub-products derived from the treatment of water, sludge, industrial and household waste, regularisation of chemical products in effluents in particular in water and sludge; consultancy and expertise in the treatment of water, effluent, industrial and household waste, sludge and ashes from urban and industrial plants; technical assistance for the selection and optimisation of above-mentioned chemical products, for the improvement in the conditions of use of these products and follow-up of the efficiency of these products; technical assistance for improvement in conditions of use of apparatus and instruments for the above mentioned services, follow-up of the efficiency of such apparatus and instruments; periodical inspection of such apparatus and instruments; construction consultancy services; drafting construction plans, in particular for sewage treatment plants; quality control; professional consultancy services (unconnected with business management); bacteriological, chemical research. Work carried out by engineers, research and design laboratories in the field of heating, air-conditioning and acoustics engineering; consultancy and expertise in heating, air-conditioning and acoustics engineering; technical assistance in the field of heating, air-conditioning and acoustics engineering; technical assistance for improvement in conditions of use of appliances and instruments for the above-mentioned services, follow-up of the efficiency of these appliances and instruments; periodical inspection of these appliances and instruments. Work conducted by engineers, research and design laboratories for the production, processing and distribution of electricity and oil products; consultancy and expertise in the processing of electricity and oil products; technical assistance to improve conditions of use of appliances and instruments for the above-mentioned services, follow-up of the efficiency of said appliances and instruments; periodical inspection of said appliances and instruments; inspection of oil wells and oil and electricity installations; oil and gas prospecting; oil field expertise; geological expertise; geological prospecting and research. Work done by engineers, research and design laboratories for construction work and erection of buildings; building consultancy; expertise in the field of construction; technical assistance to improve conditions of use of appliances and instruments for the above-mentioned services, follow-up of the efficiency of said appliances and instruments; periodical inspection of said appliances and instruments, copyright management; patent operation; data processing consultancy; software development; video taping; licensing of intellectual property rights; hire of computers and computer programmes. Blood bank services; aesthetic surgery services; pharmaceutical consultancy; cosmetic research; child nurseries; dental art; dispensaries; patient care services; homes (relief homes); convalescent homes; rest homes; retirement homes; massage services; sanatoriums; health services; funeral services, cafeteria services; cafe-restaurants; operation of camp sites; camp site services (lodging); canteen services; hotel services; hotel bookings; weather information services; hire of temporary lodgings; reservation of temporary lodgings; holiday homes; reporter services; fast, non-stop catering services (snack bars); self service restaurants; catering (meals), hire of access time to data base servers; hire service of said equipment