The provision of water and sanitation services is a key challenge worldwide.The size,complexity,and critical nature of the water and wastewater infrastructure providing such services make the planning and management o...The provision of water and sanitation services is a key challenge worldwide.The size,complexity,and critical nature of the water and wastewater infrastructure providing such services make the planning and management of these systems extremely difficult.Following the digital revolution in many areas of our lives,the water sector has begun to benefit from digital transformation.Effective utilization of remotely sensed weather and soil moisture data for more efficient irrigation(i.e.,for food production),better detection of anomalies and faults in pipe networks using artificial intelligence,the use of nature-inspired optimization to improve the management and planning of systems,and greater use of digital twins and robotics all exhibit great potential to change and improve the ways in which complex water systems are managed.However,there are additional risks associated with these developments,including—but not limited to—cybersecurity,incorrect use,and overconfidence in the capability and accuracy of digital solutions and automation.This paper identifies key advances in digital technology that have found application in the water sector,and applies forensic engineering principles to failures that have been experienced in industries further ahead with automation and digital transformation.By iden-tifying what went wrong with new digital technologies that might have contributed to high-profile acci-dents in the car and aircraft industries(e.g.,Tesla self-driving cars and the Boeing 737 MAX),it is possible to identify similar risks in the water sector,learn from them,and prevent future failures.The key findings show that:①Automation will require“humans in the loop”;②human operators must be fully aware of the technology and trained to use it;③fallback manual intervention should be available in case of tech-nology malfunctioning;④while redundant sensors may be costly,they reduce the risks due to erroneous sensor readings;⑤cybersecurity risks must be considered;and⑥ethics issues have to be considered,given the increasing automation and interconnectedness of water systems.These findings also point to major research areas related to digital transformation in the water sector.展开更多
A viscous boundary layer flow of an electrically-conducting fluid over a moving flat plate in a parallel stream with a constant magnetic field applied outside the boundary layer parallel to the plate was investigated....A viscous boundary layer flow of an electrically-conducting fluid over a moving flat plate in a parallel stream with a constant magnetic field applied outside the boundary layer parallel to the plate was investigated. The goveming system of partial differential equations was transformed to ordinary differential equations using a similarity transformation. The similarity equations were then solved numerically using a finite-difference scheme known as the Keller-box method. Numerical results of the skin friction coefficient, velocity profiles, and the induced magnetic field profiles were obtained for some values of the moving parameter, magnetic parameter, and reciprocal magnetic Prandtl number. The results indicate that dual solutions exist when the plate and the fluid move in the opposite directions up to a critical value of the moving parameter, whose value depends on the value of the magnetic parameter.展开更多
Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the technology.Furthermore,uncontrolled livestock faeces in rural communities constitute envir...Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the technology.Furthermore,uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks.Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable elec-tricity access to underserved rural communities while achieving waste management.Therefore,this study presents a hybrid solar-biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities.A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study.The findings show that the daily household energy consumption was 6.6 kWh,equivalent to 206.40 kWh/month.A 1.2-kWp and 1.2-m^(3)hybrid solar-biogas system was found to adequately power the house.Financially,the total initial investment cost of the system was$5777.20 with a net present value of$6566.78,net profit of$4443.6,a payback period of 14 years and 8 months,and a levelized cost of energy of$0.21/kWh;these include a 60%initial investment and maintenance costs subsidy.Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system.The study successfully revealed the design,specifications and upscaling mechanism of the proposed hybrid solar-biogas system.More research is required to unveil the efficacy of the system,the performance gap and the perception of the technology by the beneficiaries.展开更多
文摘The provision of water and sanitation services is a key challenge worldwide.The size,complexity,and critical nature of the water and wastewater infrastructure providing such services make the planning and management of these systems extremely difficult.Following the digital revolution in many areas of our lives,the water sector has begun to benefit from digital transformation.Effective utilization of remotely sensed weather and soil moisture data for more efficient irrigation(i.e.,for food production),better detection of anomalies and faults in pipe networks using artificial intelligence,the use of nature-inspired optimization to improve the management and planning of systems,and greater use of digital twins and robotics all exhibit great potential to change and improve the ways in which complex water systems are managed.However,there are additional risks associated with these developments,including—but not limited to—cybersecurity,incorrect use,and overconfidence in the capability and accuracy of digital solutions and automation.This paper identifies key advances in digital technology that have found application in the water sector,and applies forensic engineering principles to failures that have been experienced in industries further ahead with automation and digital transformation.By iden-tifying what went wrong with new digital technologies that might have contributed to high-profile acci-dents in the car and aircraft industries(e.g.,Tesla self-driving cars and the Boeing 737 MAX),it is possible to identify similar risks in the water sector,learn from them,and prevent future failures.The key findings show that:①Automation will require“humans in the loop”;②human operators must be fully aware of the technology and trained to use it;③fallback manual intervention should be available in case of tech-nology malfunctioning;④while redundant sensors may be costly,they reduce the risks due to erroneous sensor readings;⑤cybersecurity risks must be considered;and⑥ethics issues have to be considered,given the increasing automation and interconnectedness of water systems.These findings also point to major research areas related to digital transformation in the water sector.
文摘A viscous boundary layer flow of an electrically-conducting fluid over a moving flat plate in a parallel stream with a constant magnetic field applied outside the boundary layer parallel to the plate was investigated. The goveming system of partial differential equations was transformed to ordinary differential equations using a similarity transformation. The similarity equations were then solved numerically using a finite-difference scheme known as the Keller-box method. Numerical results of the skin friction coefficient, velocity profiles, and the induced magnetic field profiles were obtained for some values of the moving parameter, magnetic parameter, and reciprocal magnetic Prandtl number. The results indicate that dual solutions exist when the plate and the fluid move in the opposite directions up to a critical value of the moving parameter, whose value depends on the value of the magnetic parameter.
文摘Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the technology.Furthermore,uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks.Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable elec-tricity access to underserved rural communities while achieving waste management.Therefore,this study presents a hybrid solar-biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities.A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study.The findings show that the daily household energy consumption was 6.6 kWh,equivalent to 206.40 kWh/month.A 1.2-kWp and 1.2-m^(3)hybrid solar-biogas system was found to adequately power the house.Financially,the total initial investment cost of the system was$5777.20 with a net present value of$6566.78,net profit of$4443.6,a payback period of 14 years and 8 months,and a levelized cost of energy of$0.21/kWh;these include a 60%initial investment and maintenance costs subsidy.Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system.The study successfully revealed the design,specifications and upscaling mechanism of the proposed hybrid solar-biogas system.More research is required to unveil the efficacy of the system,the performance gap and the perception of the technology by the beneficiaries.
