Steel is a particularly challenging material to semi-solid process because of the high temperatures involved and the potential for surface oxidation.Here,the experience of semi-solid processing is reviewed and the cur...Steel is a particularly challenging material to semi-solid process because of the high temperatures involved and the potential for surface oxidation.Here,the experience of semi-solid processing is reviewed and the current situation in relation to commercial application is assessed.The review will include discussion of the range of potential steel materials which are amenable to thixoformingn and identification of suitable steels;modelling of die fill and rheological properties of semi solid steel;technology considerations for industrialisation;die development and the properties of thixoformed products.展开更多
As a result of immense industrialisation and high population growth, groundwater is heavily relied on in Lagos metropolis to serve as an alternative source of water where surface water is seriously polluted. The conti...As a result of immense industrialisation and high population growth, groundwater is heavily relied on in Lagos metropolis to serve as an alternative source of water where surface water is seriously polluted. The continued reliance on ground water has resulted in its decline in quantity and quality. In this study, the coastal aquifers of Lagos metropolis were selected for an assessment of its groundwater quality and impact of saline intrusion. Water samples collected along the coastal region were subjected to various physicochemical analyses. Results obtained were compared with permissible values for drinking water stated by Federal Environmental Protection Agency (FEPA) and World Health Organization (WHO). The results revealed that all the water samples were significantly hard (range 522.14 – 1233.34mg/L). The salinity was delineated by conductivity measurements. Three samples had specific conductance above the stated limits for fresh water. The samples however met the stipulated limits for drinking water for the other tested parameters.展开更多
基金University of Liège,Belgium and EU COST 541 "ThixoSteel"
文摘Steel is a particularly challenging material to semi-solid process because of the high temperatures involved and the potential for surface oxidation.Here,the experience of semi-solid processing is reviewed and the current situation in relation to commercial application is assessed.The review will include discussion of the range of potential steel materials which are amenable to thixoformingn and identification of suitable steels;modelling of die fill and rheological properties of semi solid steel;technology considerations for industrialisation;die development and the properties of thixoformed products.
文摘As a result of immense industrialisation and high population growth, groundwater is heavily relied on in Lagos metropolis to serve as an alternative source of water where surface water is seriously polluted. The continued reliance on ground water has resulted in its decline in quantity and quality. In this study, the coastal aquifers of Lagos metropolis were selected for an assessment of its groundwater quality and impact of saline intrusion. Water samples collected along the coastal region were subjected to various physicochemical analyses. Results obtained were compared with permissible values for drinking water stated by Federal Environmental Protection Agency (FEPA) and World Health Organization (WHO). The results revealed that all the water samples were significantly hard (range 522.14 – 1233.34mg/L). The salinity was delineated by conductivity measurements. Three samples had specific conductance above the stated limits for fresh water. The samples however met the stipulated limits for drinking water for the other tested parameters.
