Calendar: 1968-1969 Page 436

xciv Annual Report of the Delegacy 1966 He also introduced session at the Conference on 'Educating and Training of Engineers for Africa' held at Kumasi Ghana in July Following the Aberfan disaster Professor Nash was invited by the National Coal Board to advise them on the stability of the shale tip and he was one of the final expert witnesses to give evidence to the Tribunal He also gave evidence on the stability of the sea bed at the public enquiry set up to investigate the loss of the drilling-rig Sea Gem in the North Sea Dr White visited number of universities in Denmark and Sweden for discussions on research in fluid flow The Civil Engineering department played an active part in an inter- national conference on Prestressed Concrete Pressure Vessels in March Professor Ross was member of the organising committee and also acted as Reporter General for two of the sessions Dr England presented paper describing some of his recent experimental and analytical researches Dr Hussey gave lectures to research colloquia at University College London and at the University College of Swansea in which he discussed special problems in the analysis of structures Mr Charlton introduced the topic 'Air entrainment problems in civil engineering' at seminar for university teachers at the Univer- sity of Aberdeen Research activity in the Civil Engineering department was sustained at high level Studies of the creep of concrete were pursued and certain fundamental concepts of great importance in nuclear power plants were published and attracted widespread interest Research into the long-term strains in concrete under three-dimensional stressing commenced last year with the aid of an grant began to produce significant results The displacements and cracking of reinforced- concrete structures under sustained loading topic of importance when drafting national codes of practice is further item in the research programme The effects of differential thermal creep in concrete struc- tures is an important subject of study both experimentally and theoretic- ally In the field of continuum mechanics the theory of fluid saturated porous-elastic and porous-plastic media is being enlarged The be- haviour of soils under transient loads topic of importance in the foundations of many structures was examined with the aid of equip- ment specially developed in the department The use of specially