This paper presents an overview of the recent developments in hybrid wind-wave energy.With the focus on floating concepts,the possible configurations introduced in the literature are categorized and depicted,and the m...This paper presents an overview of the recent developments in hybrid wind-wave energy.With the focus on floating concepts,the possible configurations introduced in the literature are categorized and depicted,and the main conclusions obtained from the references are summarized.Moreover,offshore wind and wave resources are discussed in terms of complementarity and supplementarity,offering a new perspective to developing hybrid wind-wave energy systems that look for synergies not limited to maximizing power output.Then,the feasibility of the concepts under development is discussed in detail,with focus on technical feasibility,dynamic feasibility and limitations of the methods employed.The hybrid configurations that surpassed the experimental validation phase are highlighted,and the experimental results are summarized.By compiling more than 40 floating wind turbine concepts,new relations are drawn between power,wind turbine dimensions,platforms’draft and displacement,which are further related to the payload allowance of the units to accommodate wave devices and onboard power take-off systems.Bearing in mind that it is a challenge to model the exact dynamics of hybrid floating wind-wave platforms,this paper elucidates the current research gaps,limitations and future trends in the field.Lastly,based on the overview and topics discussed,several major conclusions are drawn concerning hybrid synergies,dynamics and hydrodynamics of hybrid platforms,feasibility of concepts,among other regards.展开更多
This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal syste...This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal systems have the heat, permeability and fluid, requiring only drilling down to °C, normal heat flow or decaying radiogenic granite as heat sources, and used in district heating. Medium-temperature (MT) 100°C - 190°C, and high-temperature (HT) 190°C - 374°C resources are mostly at plate boundaries, with volcanic intrusive heat source, used mostly for electricity generation. Single well capacities are °C - 500°C) and a range of depths (1 m to 20 Km), but lack permeability or fluid, thus requiring stimulations for heat extraction by conduction. HVAC is 1 - 2 m deep and shallow geothermal down to 500 m in wells, both capturing °C, with °C are either advanced by geothermal developers at <7 Km depth (Enhanced Geothermal Systems (EGS), drilling below brittle-ductile transition zones and under geothermal fields), or by the Oil & Gas industry (Advanced Geothermal Systems, heat recovery from hydrocarbon wells or reservoirs, Superhot Rock Geothermal, and millimeter-wave drilling down to 20 Km). Their primary aim is electricity generation, relying on closed-loops, but EGS uses fractures for heat exchange with earthquake risks during fracking. Unconventional approaches could be everywhere, with shallow geothermal already functional. The deeper and hotter unconventional alternatives are still experimental, overcoming costs and technological challenges to become fully commercial. Meanwhile, the conventional geothermal resources remain the most proven opportunities for investments and development.展开更多
Low-and middle-income countries(LMICs)bear the greater share of the global mental health burden but are ill-equipped to deal with it because of severe resource constraints leading to a large treatment gap.The remote p...Low-and middle-income countries(LMICs)bear the greater share of the global mental health burden but are ill-equipped to deal with it because of severe resource constraints leading to a large treatment gap.The remote provision of mental health services by digital means can effectively augment conventional services in LMICs to reduce the treatment gap.Digital psychiatry in LMICs has always lagged behind high-income countries,but there have been encouraging developments in the last decade.There is increasing research on the efficacy of digital psychiatric interventions.However,the evidence is not adequate to conclude that digital psychiatric interventions are invariably effective in LMICs.A striking development has been the rise in mobile and smartphone ownership in LMICs,which has driven the increasing use of mobile technologies to deliver mental health services.An innovative use of mobile technologies has been to optimize task-shifting,which involves delivering mental healthcare services in community settings using non-specialist health professionals.Emerging evidence from LMICs shows that it is possible to use digital tools to train non-specialist workers effectively and ensure that the psychosocial interventions they deliver are efficacious.Despite these promising developments,many barriers such as service costs,underdeveloped infrastructure,lack of trained professionals,and significant disparities in access to digital services impede the progress of digital psychiatry in LMICs.To overcome these barriers,digital psychiatric services in LMICs should address contextual factors influencing the delivery of digital services,ensure collaboration between different stakeholders,and focus on reducing the digital divide.展开更多
基金supported by the Portuguese Foundation for Science and Technology(Fundação para a Ciência e Tecnologia-FCT)it contributes to the Strategic Research Plan of the Centre for Marine Technology and Ocean Engineering(Grant No.UIDB/UIDP/00134/2020)funded the first author for his PhD Scholarship(Grant No.SFRH/BD/145602/2019).
文摘This paper presents an overview of the recent developments in hybrid wind-wave energy.With the focus on floating concepts,the possible configurations introduced in the literature are categorized and depicted,and the main conclusions obtained from the references are summarized.Moreover,offshore wind and wave resources are discussed in terms of complementarity and supplementarity,offering a new perspective to developing hybrid wind-wave energy systems that look for synergies not limited to maximizing power output.Then,the feasibility of the concepts under development is discussed in detail,with focus on technical feasibility,dynamic feasibility and limitations of the methods employed.The hybrid configurations that surpassed the experimental validation phase are highlighted,and the experimental results are summarized.By compiling more than 40 floating wind turbine concepts,new relations are drawn between power,wind turbine dimensions,platforms’draft and displacement,which are further related to the payload allowance of the units to accommodate wave devices and onboard power take-off systems.Bearing in mind that it is a challenge to model the exact dynamics of hybrid floating wind-wave platforms,this paper elucidates the current research gaps,limitations and future trends in the field.Lastly,based on the overview and topics discussed,several major conclusions are drawn concerning hybrid synergies,dynamics and hydrodynamics of hybrid platforms,feasibility of concepts,among other regards.
文摘This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal systems have the heat, permeability and fluid, requiring only drilling down to °C, normal heat flow or decaying radiogenic granite as heat sources, and used in district heating. Medium-temperature (MT) 100°C - 190°C, and high-temperature (HT) 190°C - 374°C resources are mostly at plate boundaries, with volcanic intrusive heat source, used mostly for electricity generation. Single well capacities are °C - 500°C) and a range of depths (1 m to 20 Km), but lack permeability or fluid, thus requiring stimulations for heat extraction by conduction. HVAC is 1 - 2 m deep and shallow geothermal down to 500 m in wells, both capturing °C, with °C are either advanced by geothermal developers at <7 Km depth (Enhanced Geothermal Systems (EGS), drilling below brittle-ductile transition zones and under geothermal fields), or by the Oil & Gas industry (Advanced Geothermal Systems, heat recovery from hydrocarbon wells or reservoirs, Superhot Rock Geothermal, and millimeter-wave drilling down to 20 Km). Their primary aim is electricity generation, relying on closed-loops, but EGS uses fractures for heat exchange with earthquake risks during fracking. Unconventional approaches could be everywhere, with shallow geothermal already functional. The deeper and hotter unconventional alternatives are still experimental, overcoming costs and technological challenges to become fully commercial. Meanwhile, the conventional geothermal resources remain the most proven opportunities for investments and development.
文摘Low-and middle-income countries(LMICs)bear the greater share of the global mental health burden but are ill-equipped to deal with it because of severe resource constraints leading to a large treatment gap.The remote provision of mental health services by digital means can effectively augment conventional services in LMICs to reduce the treatment gap.Digital psychiatry in LMICs has always lagged behind high-income countries,but there have been encouraging developments in the last decade.There is increasing research on the efficacy of digital psychiatric interventions.However,the evidence is not adequate to conclude that digital psychiatric interventions are invariably effective in LMICs.A striking development has been the rise in mobile and smartphone ownership in LMICs,which has driven the increasing use of mobile technologies to deliver mental health services.An innovative use of mobile technologies has been to optimize task-shifting,which involves delivering mental healthcare services in community settings using non-specialist health professionals.Emerging evidence from LMICs shows that it is possible to use digital tools to train non-specialist workers effectively and ensure that the psychosocial interventions they deliver are efficacious.Despite these promising developments,many barriers such as service costs,underdeveloped infrastructure,lack of trained professionals,and significant disparities in access to digital services impede the progress of digital psychiatry in LMICs.To overcome these barriers,digital psychiatric services in LMICs should address contextual factors influencing the delivery of digital services,ensure collaboration between different stakeholders,and focus on reducing the digital divide.
