Anchor bolts are commonly used throughout underground mining and tunnelling operations to improve roof stability.However,premature failures of anchor bolts are significant safety risks in underground excavations aroun...Anchor bolts are commonly used throughout underground mining and tunnelling operations to improve roof stability.However,premature failures of anchor bolts are significant safety risks in underground excavations around the world due to susceptible bolt materials,a moist and corrosive environment and tensile stress.In this paper,laboratory experiments and hydrogeochemical models were combined to investigate anchor bolt corrosion and failure associated with aqueous environments in underground coal mines.Experimental data and collated mine water chemistry data were used to simulate bolt corrosion reactions with groundwater and rock materials with the PHREEQC code.A series of models quantified reactions involving iron and carbon under aerobic and anaerobic conditions in comparison with ion,pH and pE trends in experimental data.The models showed that corrosion processes are inhibited by some natural environmental factors,because dissolved oxygen would cause more iron from the bolts to oxidize into solution.These interdisciplinary insights into corrosion failure of underground anchor bolts confirm that environmental factors are important contributors to stress corrosion cracking.展开更多
Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered envir...Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered environmentally friendly,the understanding on absorbing and oxidative capacity of soot emitted from them are still unclear.The watersoluble organic carbon(WSOC)content,surface chemical structure,light absorption and oxidative potential(OPDTT)of soot from biodiesel/diesel and chemicals/diesel blends were investigated utilizing total organic carbon analyzer,X-ray photoelectron spectrometer,ultraviolet–visible spectrophotometry and dithiothreitol(DTT)assay.The differences and correlations between soot properties were statistically analyzed.Chemicals/diesel blends soot owned significantly higher WSOC content,ratio of mass absorbing efficiency(MAE)in250 and 365 nm(E2/E3),OPDTT,and higher surface carbonyl content.Coconut biodiesel/diesel blends soot contained evidently higher aromatic carbon–oxygen single bond(ArC–O)content,and higher MAE365.The individual comparison of biodiesel/diesel blends showed20%coconut biodiesel blend owned the lowest WSOC,E2/E3 and OPDTT,while highest ArC–O and MAE365,representing strongest absorbing properties.Association analysis showed OPDTTwas significantly positively correlated with WSOC.Further,the evident negative correlation between MAE365 and OPDTT was observed.Our results showed coconut biodiesel/diesel blends soot induced lower levels of oxidative potential,whereas absorption of light was higher,which have far reaching consequences on climate forcing.Therefore,it is important to evaluate the balance point between light-absorbing properties and oxidative potential,under the wide use of biodiesel.展开更多
The presented study focused on developing an innovative decision-making framework to select the best renewable-power-plant technologies,considering comprehensive techno-economic and environmental variables.Due to the ...The presented study focused on developing an innovative decision-making framework to select the best renewable-power-plant technologies,considering comprehensive techno-economic and environmental variables.Due to the favourable conditions,Australia was selected as the case study.A fuzzy-logic method and analytical hierarchy process were applied to prioritize different renewable-energy power plants.The techno-economic factors included levelized cost of energy,initial cost,simple payback time,and operation and maintenance costs along with environmental factors including carbon payback time,energy payback time and greenhouse-gas emissions were used to rank the power plants.The results showed that the capital cost and simple payback time had the highest priority from an economic point of view.In comparison,greenhouse-gas emissions and carbon payback time were the dominant environmental factors.The analysis results provided economic and environmental priority tables for developing different power plants in the current state and a future scenario by 2030.The fuzzy results and pairwise composite matrix of alternatives indicated that the onshore wind,offshore wind,single-axis tracker polycrystalline photovoltaic,single-axis tracker monocrystalline photovoltaic,fix-tilted polycrystalline photovoltaic and fix-tilted monocrystalline photovoltaic scored the highest in the current state.In contrast,by 2030,the single-axis tracker photovoltaic power plants will be the best choice in the future scenario in Australia.Finally,the results were used and analysed to recommend and suggest several policy implementations and future research studies.展开更多
基金Project(140100153)supported by Australian Research Council Linkage Grant。
文摘Anchor bolts are commonly used throughout underground mining and tunnelling operations to improve roof stability.However,premature failures of anchor bolts are significant safety risks in underground excavations around the world due to susceptible bolt materials,a moist and corrosive environment and tensile stress.In this paper,laboratory experiments and hydrogeochemical models were combined to investigate anchor bolt corrosion and failure associated with aqueous environments in underground coal mines.Experimental data and collated mine water chemistry data were used to simulate bolt corrosion reactions with groundwater and rock materials with the PHREEQC code.A series of models quantified reactions involving iron and carbon under aerobic and anaerobic conditions in comparison with ion,pH and pE trends in experimental data.The models showed that corrosion processes are inhibited by some natural environmental factors,because dissolved oxygen would cause more iron from the bolts to oxidize into solution.These interdisciplinary insights into corrosion failure of underground anchor bolts confirm that environmental factors are important contributors to stress corrosion cracking.
基金supported by the National Natural Science Foundation of China(Nos.21577003,21876003)the National Key Research and Development Program of China(No.2016YFC0202200)+1 种基金the Australian Research Council under Discovery Project(No.DP180102632)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.19Y02ESPCP)
文摘Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered environmentally friendly,the understanding on absorbing and oxidative capacity of soot emitted from them are still unclear.The watersoluble organic carbon(WSOC)content,surface chemical structure,light absorption and oxidative potential(OPDTT)of soot from biodiesel/diesel and chemicals/diesel blends were investigated utilizing total organic carbon analyzer,X-ray photoelectron spectrometer,ultraviolet–visible spectrophotometry and dithiothreitol(DTT)assay.The differences and correlations between soot properties were statistically analyzed.Chemicals/diesel blends soot owned significantly higher WSOC content,ratio of mass absorbing efficiency(MAE)in250 and 365 nm(E2/E3),OPDTT,and higher surface carbonyl content.Coconut biodiesel/diesel blends soot contained evidently higher aromatic carbon–oxygen single bond(ArC–O)content,and higher MAE365.The individual comparison of biodiesel/diesel blends showed20%coconut biodiesel blend owned the lowest WSOC,E2/E3 and OPDTT,while highest ArC–O and MAE365,representing strongest absorbing properties.Association analysis showed OPDTTwas significantly positively correlated with WSOC.Further,the evident negative correlation between MAE365 and OPDTT was observed.Our results showed coconut biodiesel/diesel blends soot induced lower levels of oxidative potential,whereas absorption of light was higher,which have far reaching consequences on climate forcing.Therefore,it is important to evaluate the balance point between light-absorbing properties and oxidative potential,under the wide use of biodiesel.
文摘The presented study focused on developing an innovative decision-making framework to select the best renewable-power-plant technologies,considering comprehensive techno-economic and environmental variables.Due to the favourable conditions,Australia was selected as the case study.A fuzzy-logic method and analytical hierarchy process were applied to prioritize different renewable-energy power plants.The techno-economic factors included levelized cost of energy,initial cost,simple payback time,and operation and maintenance costs along with environmental factors including carbon payback time,energy payback time and greenhouse-gas emissions were used to rank the power plants.The results showed that the capital cost and simple payback time had the highest priority from an economic point of view.In comparison,greenhouse-gas emissions and carbon payback time were the dominant environmental factors.The analysis results provided economic and environmental priority tables for developing different power plants in the current state and a future scenario by 2030.The fuzzy results and pairwise composite matrix of alternatives indicated that the onshore wind,offshore wind,single-axis tracker polycrystalline photovoltaic,single-axis tracker monocrystalline photovoltaic,fix-tilted polycrystalline photovoltaic and fix-tilted monocrystalline photovoltaic scored the highest in the current state.In contrast,by 2030,the single-axis tracker photovoltaic power plants will be the best choice in the future scenario in Australia.Finally,the results were used and analysed to recommend and suggest several policy implementations and future research studies.
