40 research outputs found
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Does the root to shoot ratio show a hormetic response to stress? An ecological and environmental perspective
Root/shoot (R/S) ratio is an important index for assessing plant health, and has received increased attention in the last decades as a sensitive indicator of plant stress induced by chemical or physical agents. The R/S ratio has been discussed in the context of ecological theory and its potential importance in ecological succession, where species follow different strategies for above-ground growth for light or below-ground competition for water and nutrients. We present evidence showing the R/S ratio follows a biphasic dose–response relationship under stress, typical of hormesis. The R/S ratio in response to stress has been widely compared among species and ecological succession classes. It is constrained by a variety of factors such as ontogeny. Furthermore, the current literature lacks dose–response studies incorporating the full dose–response continuum, hence limiting scientific understanding and possible valuable application. The data presented provide an important perspective for new-generation studies that can advance current ecological understanding and improve carbon storage estimates by R/S ratio considerations. Hormetic response of the R/S ratio can have an important role in forestry for producing seedlings with desired characteristics to achieve maximum health/productivity and resilience under plantation conditions
Integrating children's perspectives in policy-making to combat poverty and social exclusion experienced by single-parent families: a transnational comparative approach
This is the final report of a research project that addressed social exclusion and poverty as it relates to single parent families and their children in particular. The rising numbers of single parent families and
children throughout the EU and the increased likelihood that these families will live in poverty and experience many different forms of social exclusion in their daily lives brings in sharp focus the need to address the issue as an urgent one in our efforts to eradicate poverty and social exclusion. The focus on the children of single parent
families seeks to rectify a long-standing problem in our knowledge and understanding of single parent families and the social problems they face, namely, the fact that little, if anything, is known about how these children experience and understand their lives as members of these families. The research set out to contribute to policy development and the transnational exchange of best practice by adding a much-neglected dimension on single parent families. The project used a cross-national comparative qualitative research design and methods (Mangen 1999) which involved all partners in the design of each research phase
including the analysis; partners were England, Cyprus and Greece
A review of solar hybrid photovoltaic-thermal (PV-T) collectors and systems
In this paper, we provide a comprehensive overview of the state-of-the-art in hybrid PV-T collectors and the wider systems within which they can be implemented, and assess the worldwide energy and carbon mitigation potential of these systems. We cover both experimental and computational studies, identify opportunities for performance enhancement, pathways for collector innovation, and implications of their wider deployment at the solar-generation system level. First, we classify and review the main types of PV-T collectors, including air-based, liquid-based, dual air–water, heat-pipe, building integrated and concentrated PV-T collectors. This is followed by a presentation of performance enhancement opportunities and pathways for collector innovation. Here, we address state-of-the-art design modifications, next-generation PV cell technologies, selective coatings, spectral splitting and nanofluids. Beyond this, we address wider PV-T systems and their applications, comprising a thorough review of solar combined heat and power (S–CHP), solar cooling, solar combined cooling, heat and power (S–CCHP), solar desalination, solar drying and solar for hydrogen production systems. This includes a specific review of potential performance and cost improvements and opportunities at the solar-generation system level in thermal energy storage, control and demand-side management. Subsequently, a set of the most promising PV-T systems is assessed to analyse their carbon mitigation potential and how this technology might fit within pathways for global decarbonization. It is estimated that the REmap baseline emission curve can be reduced by more than 16% in 2030 if the uptake of solar PV-T technologies can be promoted. Finally, the review turns to a critical examination of key challenges for the adoption of PV-T technology and recommendations
Arthropod outbreaks, stressors, and sublethal stress
Outbreaks are characterized by a sudden increase in population density of a given species, and are recognized as an important phenomenon in both natural and artificial systems. Climate and anthropogenic stressors are the main abiotic drivers of outbreaks directly affecting arthropod populations, or influencing them indirectly through their heterospecifics and resources (e.g., host plants). Both are dose- or intensity-dependent and mainly sublethal when outbreaks are considered. Thus, sublethal stimulation or hormesis is an important phenomenon to consider. However, its study is restricted to a few (agricultural) settings and neglects key complexities of biological systems, including arthropods as an ecocosm of symbionts, the role of arthropod interactions, and the co-occurrence of multiple stressors. Therefore, more research is required to tackle the complexities of biological systems
Building integration of active solar energy systems: A review of geometrical and architectural characteristics
Solar building integration, differs from everyday active solar energy systems on a building envelope, because the active system replaces building elements and are integrated into the architectural envelope and structure. This article aims to present a comprehensive review and analyse the geometrical and architectural characteristics and design possibilities offered by the building integration of active solar energy systems. The literature studies are separated into double and single façade solutions, as well as solutions where the active system performs as an independent architectural element of the building. It is concluded that the majority of the researchers preferred the single façade solutions, followed by the double façade systems since the second one offers a cavity which can be used as an air duct for the BIPV (Building Integrated Photovoltaics) and BIPV/T (Building Integrated Photovoltaic/Thermal) solutions. This work provides an overview of the state of the art systems and geometrical solutions emerging by the development, research, and applications of the BISS (Building Integrated Solar Systems)
Preliminary assessment of waste heat potential in major European industries
Abstract Industrial processes are currently responsible for almost 26% of European primary energy consumptions (275 Mtoe/yr). Furthermore, most of the energy sources that drive the industrial sector are fossil fuel based. Every industrial process is characterised by a multitude of waste heat streams at different temperature levels whose recovery would undoubtedly contribute to the enhancement of the sustainability of the industrial sites and their products. Waste heat recovery systems can offer significant energy savings and substantial greenhouse gas emission reductions. For the latter to materialise technological improvements and innovations aimed at improving the energy efficiency of heat recovery equipment and reducing installation costs should take place. This paper outlines the opportunities and the potential for industrial heat recovery in the European Union by identifying and quantifying primary energy consumption in the major industrial sectors and their related waste streams and temperature levels. Through a systematic analysis considering waste heat and Carnot’s potential estimation, detailed results are given for all industrial sectors, temperature ranges and EU countries. The ‘big picture’ is rather promising with regards to the estimated total waste heat potential.The research presented in this paper has received funding from the European Union’s Horizon 2020 research and
innovation programme under grant agreement No. 680599.
Aspects of the work are also funded by the Centre for Sustainable Energy Use in Food Chains (CSEF). CSEF is an
End Use Energy Demand Centre funded by the Research Councils UK, Grant No: EP/K011820/1
Building integration of active solar energy systems: A review of geometrical and architectural characteristics
Solar building integration, differs from everyday active solar energy systems on a building envelope, because the active system replaces building elements and are integrated into the architectural envelope and structure. This article aims to present a comprehensive review and analyse the geometrical and architectural characteristics and design possibilities offered by the building integration of active solar energy systems. The literature studies are separated into double and single façade solutions, as well as solutions where the active system performs as an independent architectural element of the building. It is concluded that the majority of the researchers preferred the single façade solutions, followed by the double façade systems since the second one offers a cavity which can be used as an air duct for the BIPV (Building Integrated Photovoltaics) and BIPV/T (Building Integrated Photovoltaic/Thermal) solutions. This work provides an overview of the state of the art systems and geometrical solutions emerging by the development, research, and applications of the BISS (Building Integrated Solar Systems)
Waste Heat Recovery in the EU industry and proposed new technologies
In the European Union (EU), industrial sectors use 26% of the primary energy consumption and are characterized by large amounts of energy losses in the form of waste heat at different temperature levels. Their recovery is a challenge but also an opportunity for science and business. In this study, after a brief description of the conventional Waste Heat Recovery (WHR) approaches, the novel technologies under development within the I-ThERM Horizon 2020 project are presented and assessed from an energy and market perspectives. These technologies are: heat to power conversion systems based on bottoming thermodynamic cycles (Trilateral Flash Cycle for low grade waste heat and Joule-Brayton cycle working with supercritical carbon dioxide for high temperature waste heat sources); heat recovery devices based on heat pipes (flat heat pipe for high grade radiative heat sources and condensing economizer for acidic effluents).European Union’s Horizon 2020 research and innovation programme, the Centre for Sustainable Energy Use in Food Chains (CSEF) and the Engineering and Physical Sciences Research Council (EPSRC) funded project ‘Optimising Energy Management in Industry-OPTEMIN