Towards an\u2028 EU research and innovation policy agenda for nature-based solutions & re-naturing cities. Final report of the Horizon 2020 expert group on nature-based solutions and re-naturing cities.

1. Nature-based solutions harness the power and sophistication of nature to turn environmental, social and economic challenges into innovation opportunities. They can address a variety of societal challenges in sustainable ways, with the potential to contribute to green growth, 'future-proofing' society, fostering citizen well-being, providing business opportunities and positioning Europe as a leader in world markets. \u2028 2. Nature-based solutions are actions which are inspired by, supported by or copied from nature. They have tremendous potential to be energy and resource-efficient and resilient to change, but to be successful they must be adapted to local conditions. \u2028 3. Many nature-based solutions result in multiple co-benefits for health, the economy, society and the environment, and thus they can represent more efficient and cost-effective solutions than more traditional approaches. \u2028 4. An EU Research & Innovation (R&I) agenda on nature-based solutions will enable Europe to become a world leader both in R&I and in the growing market for nature-based solutions. For this, the evidence base for the effectiveness of nature-based solutions needs to be developed and then used to implement solutions. Both need to be done in conjunction with stakeholders. The potential for transferability and upscaling of solutions also requires further investigation. There is also a need to develop a systemic approach that combines technical, business, finance, governance, regulatory and social innovation. \u2028 5. Four principal goals have been identified that can be addressed by nature-based solutions: �� Enhancing sustainable urbanisation through nature-based solutions can stimulate economic growth as well as improving the environment, making cities more attractive, and enhancing human well-being. \u2028 �� Restoring degraded ecosystems using nature-based solutions can improve the resilience of ecosystems, enabling them to deliver vital ecosystem services and also to meet other societal challenges. \u2028 �� Developing climate change adaptation and mitigation using nature-based solutions can provide more resilient responses and enhance the storage of carbon. \u2028 �� Improving risk management and resilience using nature-based solutions can lead to greater benefits than conventional methods and offer synergies in reducing multiple risks. \u2028 6. Based on the four goals, seven nature-based solutions for R&I actions are recommended to be taken forward by the European Commission and Member States: �� Urban regeneration through nature-based solutions \u2028 �� Nature-based solutions for improving well-being in urban areas \u2028 �� Establishing nature-based solutions for coastal resilience \u2028 �� Multi-functional nature-based watershed management and ecosystem restoration \u2028 �� Nature-based solutions for increasing the sustainability of the use of matter and energy \u2028 �� Nature-based solutions for enhancing the insurance value of ecosystems \u2028 �� Increasing carbon sequestration through nature-based solutions \u2028This report was produced by the Horizon 2020 Expert Group on 'Nature-Based Solutions and Re- Naturing Cities', informed by the findings of an e-consultation and a stakeholder workshop. \u202

Polyradical character and spin frustration in fullerene molecules: An ab initio non-collinear Hartree--Fock study

Most {\em ab initio} calculations on fullerene molecules have been carried out based on the paradigm of the H\"uckel model. This is consistent with the restricted nature of the independent-particle model underlying such calculations, even in single-reference-based correlated approaches. On the other hand, previous works on some of these molecules using model Hamiltonians have clearly indicated the importance of short-range inter-atomic spin-spin correlations. In this work, we consider {\em ab initio} non-collinear Hartree--Fock (HF) solutions for representative fullerene systems: the bowl, cage, ring, and pentagon isomers of C$_{20}$, and the larger C$_{30}$, C$_{36}$, C$_{60}$, C$_{70}$, and C$_{84}$ fullerene cages. In all cases but the ring we find that the HF minimum corresponds to a truly non-collinear solution with a torsional spin density wave. Optimized geometries at the generalized HF (GHF) level lead to fully symmetric structures, even in those cases where Jahn-Teller distortions have been previously considered. The nature of the GHF solutions is consistent with the $\pi$-electron space becoming polyradical in nature: each $p$-orbital remains effectively singly occupied. The spin frustration, induced by the pentagon rings in an otherwise anti-ferromagnetic background, is minimized at the HF level by aligning the spins in non-collinear arrangements. The long-range magnetic ordering observed is reminiscent of the character of broken symmetry HF solutions in polyacene systems.Comment: 16 figure

The role of tacit knowledge in the construction industry: towards a definition

The construction industry is perceived as one of the knowledge-based value creating sectors of the economy; however, it faces many challenges, especially in terms of performance, due to its intrinsic nature. Different knowledge-based solutions have been proposed in the past to overcome this problem. However, the process-based solutions, enhancing personalisation strategies and interactions between construction workers to generate and share tacit knowledge, would be much more relevant to overcome KM problems in construction organisations. As the initial step towards the management of tacit knowledge, this paper examines the nature and importance of tacit knowledge in the construction industry. Based on research findings a definition for tacit knowledge is synthesised to: understanding, capabilities, skills and the experiences of individuals; often expressed in human actions in the form of thoughts, points of view, evaluation and advice; generated and acquired through past experiences, individuals, and repositories; utilised for the benefit of individual and organisational development

Trust but verify: The case for astrophysical black holes

This article is based on a pair of lectures given at the 2005 SLAC Summer Institute. Our goal is to motivate why most physicists and astrophysicists accept the hypothesis that the most massive, compact objects seen in many astrophysical systems are described by the black hole solutions of general relativity. We describe the nature of the most important black hole solutions, the Schwarzschild and the Kerr solutions. We discuss gravitational collapse and stability in order to motivate why such objects are the most likely outcome of realistic astrophysical collapse processes. Finally, we discuss some of the observations which -- so far at least -- are totally consistent with this viewpoint, and describe planned tests and observations which have the potential to falsify the black hole hypothesis, or sharpen still further the consistency of data with theory.Comment: Based on invited lectures at the 2005 SLAC Summer Institute (SSI05-L006). 22 pages, 5 eps figures. Very embarrassing typo in third paragraph fixed; numerous minor typos throughout paper fixe

Point Charge Self-Energy in the General Relativity

Singularities in the metric of the classical solutions to the Einstein equations (Schwarzschild, Kerr, Reissner -- Nordstr\"om and Kerr -- Newman solutions) lead to appearance of generalized functions in the Einstein tensor that are not usually taken into consideration. The generalized functions can be of a more complex nature than the Dirac \d-function. To study them, a technique has been used based on a limiting solution sequence. The solutions are shown to satisfy the Einstein equations everywhere, if the energy-momentum tensor has a relevant singular addition of non-electromagnetic origin. When the addition is included, the total energy proves finite and equal to $mc^2$, while for the Kerr and Kerr--Newman solutions the angular momentum is $mc {\bf a}$. As the Reissner--Nordstr\"om and Kerr--Newman solutions correspond to the point charge in the classical electrodynamics, the result obtained allows us to view the point charge self-energy divergence problem in a new fashion.Comment: VI Fridmann Seminar, France, Corsica, Corgeze, 2004, LaTeX, 6 pages, 2 fige