With the current tightening of environmental regulations of waste water treatment, there is a need for the enhancement of the treatment efficiency. This can be done through process changes, or by adding a finishing tr...With the current tightening of environmental regulations of waste water treatment, there is a need for the enhancement of the treatment efficiency. This can be done through process changes, or by adding a finishing treatment after the process, like flotation or filtration. Wetlands are also one possibility for the finishing treatment of waste water. In Finland Wetlands have been used as a polishing treatment for municipal wastewater for approx. 20 years. Most of these are natural wetlands. Using wetlands after efficient wastewater treatment is an economical way of producing high quality treated water and cutting down the pollution load of water bodies. Wetlands have also been used in the control of diffuse pollution in agriculture and forestry.展开更多
In this study, shot peening is applied to the titanium alloy Ti–6Al–4V, and the surface treatment effect on fatigue life of shot-peened specimens under high cycle loading is investigated. The induced residual stress...In this study, shot peening is applied to the titanium alloy Ti–6Al–4V, and the surface treatment effect on fatigue life of shot-peened specimens under high cycle loading is investigated. The induced residual stress is measured by using the orbital hole-drilling method. Surface profilometer and optical microscopy are employed to characterize the surface roughness and morphology. The deformed microstructure layers of the shot-peened specimens are investigated by using scanning electron microscopy. Experiments reveal that the fatigue life of Ti–6Al–4V is improved by the shot peening process, and the surface pre-peening polishing. The combination of pre-and post-peening polishing treatments further improves fatigue life of Ti–6Al–4V specimens. The present work provides useful guidelines for developing more efficient shot peening strategies.展开更多
文摘With the current tightening of environmental regulations of waste water treatment, there is a need for the enhancement of the treatment efficiency. This can be done through process changes, or by adding a finishing treatment after the process, like flotation or filtration. Wetlands are also one possibility for the finishing treatment of waste water. In Finland Wetlands have been used as a polishing treatment for municipal wastewater for approx. 20 years. Most of these are natural wetlands. Using wetlands after efficient wastewater treatment is an economical way of producing high quality treated water and cutting down the pollution load of water bodies. Wetlands have also been used in the control of diffuse pollution in agriculture and forestry.
基金the Aerospace Program and Agency for Science,Technology and Research,Singapore(A*STAR)
文摘In this study, shot peening is applied to the titanium alloy Ti–6Al–4V, and the surface treatment effect on fatigue life of shot-peened specimens under high cycle loading is investigated. The induced residual stress is measured by using the orbital hole-drilling method. Surface profilometer and optical microscopy are employed to characterize the surface roughness and morphology. The deformed microstructure layers of the shot-peened specimens are investigated by using scanning electron microscopy. Experiments reveal that the fatigue life of Ti–6Al–4V is improved by the shot peening process, and the surface pre-peening polishing. The combination of pre-and post-peening polishing treatments further improves fatigue life of Ti–6Al–4V specimens. The present work provides useful guidelines for developing more efficient shot peening strategies.
