Supramolecular catalysis is a rapidly expanding discipline which has benefited from the development of both homogeneous catalysis and supramolecular chemistry. The properties of classical metal and ...organic catalysts can now be carefully tailored by means of several suitable approaches and the choice of reversible interactions such as hydrogen bond, metal-ligand, electrostatic and hydrophobic interactions. The first part of these two subsequent reviews will be dedicated to catalytic systems for which non-covalent interactions between the partners of the reaction have been designed although mimicking enzyme properties has not been intended. Ligand, metal, organocatalyst, substrate, additive, and metal counterion are reaction partners that can be held together by non-covalent interactions. The resulting catalysts possess unique properties compared to analogues lacking the assembling properties. Depending on the nature of the reaction partners involved in the interactions, distinct applications have been accomplished, mainly (i) the building of bidentate ligand libraries (
intra
ligand-ligand), (ii) the building of di- or oligonuclear complexes (
inter
ligand-ligand), (iii) the alteration of the coordination spheres of a metal catalyst (ligand-ligand additive), and (iv) the control of the substrate reactivity (catalyst-substrate). More complex systems that involve the cooperative action of three reaction partners have also been disclosed. In this review, special attention will be given to supramolecular catalysts for which the observed catalytic activity and/or selectivity have been imputed to non-covalent interaction between the reaction partners. Additional features of these catalysts are the easy modulation of the catalytic performance by modifying one of their building blocks and the development of new catalytic pathways/reactions not achievable with classical covalent catalysts.
Non-covalent interactions constitute a suitable tool for the building and modification of catalytic systems (L = ligand, M = metal, LA = ligand additive, S = substrate, cat. = either organic or metal catalyst). This review discusses the various strategies used for the design of supramolecular catalysts.
We report the experimental observation of tunable, nonreciprocal quantum transport of a Bose-Einstein condensate in a momentum lattice. By implementing a dissipative Aharonov-Bohm (AB) ring in ...momentum space and sending atoms through it, we demonstrate a directional atom flow by measuring the momentum distribution of the condensate at different times. While the dissipative AB ring is characterized by the synthetic magnetic flux through the ring and the laser-induced loss on it, both the propagation direction and transport rate of the atom flow sensitively depend on these highly tunable parameters. We demonstrate that the nonreciprocity originates from the interplay of the synthetic magnetic flux and the laser-induced loss, which simultaneously breaks the inversion and the time-reversal symmetries. Our results open up the avenue for investigating nonreciprocal dynamics in cold atoms, and highlight the dissipative AB ring as a flexible building element for applications in quantum simulation and quantum information.
As the Architecture, Engineering and Construction sector is embracing the digital age, the processes involved in the design, construction and operation of built assets are more and more influenced by ...technologies dealing with value-added monitoring of data from sensor networks, management of this data in secure and resilient storage systems underpinned by semantic models, as well as the simulation and optimisation of engineering systems. Aside from enhancing the efficiency of the value chain, such information-intensive models and associated technologies play a decisive role in minimising the lifecycle impacts of our buildings. While Building Information Modelling provides procedures, technologies and data schemas enabling a standardised semantic representation of building components and systems, the concept of a Digital Twin conveys a more holistic socio-technical and process-oriented characterisation of the complex artefacts involved by leveraging the synchronicity of the cyber-physical bi-directional data flows. Moreover, BIM lacks semantic completeness in areas such as control systems, including sensor networks, social systems, and urban artefacts beyond the scope of buildings, thus requiring a holistic, scalable semantic approach that factors in dynamic data at different levels. The paper reviews the multi-faceted applications of BIM during the construction stage and highlights limits and requirements, paving the way to the concept of a Construction Digital Twin. A definition of such a concept is then given, described in terms of underpinning research themes, while elaborating on areas for future research.
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•The construction sector can greatly benefit from adopting a Digital Twin paradigm.•196 academic publications were reviewed on the status of BIM and Digital Twin.•The nD BIM uses during construction are analysed, along with the latest technologies.•The Digital Twin uses are discussed from several nearby engineering fields.•A conceptual framework for a Construction Digital Twin is proposed.
Smart energy and electricity networks are a crucial component in building smart city architectures; their consistent and harmonized inclusion in the smart city design should be carefully considered ...through a detailed analysis of the impacts (environmental, energy, economic, societal) and the implementation of cost benefit analysis (CBA), not only in terms of managing the grid itself but also in a wider perspective that includes environmental, security, and social aspects. This paper first discusses the main impact that smart grid deployment has, in different respects, in smart cities and then presents a methodology for an extended CBA, able to go beyond the strictly financial aspects. It is based on previous developments at the European level. The methodology conceptually illustrated can naturally be extended to the assessment of proposals for the development of smart cities.
One way how to limit the effect of increased moisture on building constructions is the hydrophobization of these constructions or parts thereof. However, hydrophobization protection may be subjected ...of degradation effects that may reduce its effectiveness. The contribution deals with monitoring the degradation degree of hydrophobization protection of ceramic masonry elements caused by climatic effects. There is a comparison available between accelerated/simulated degradation and non-accelerated real-time degradation. The results are compared with the real capillary absorption of the untreated/non-hydrophobized wall blocks.
Abstract
The circulation of used building components is performed through human labour such as assessment, logistics, design, and (de-)construction. This paper analyses different kinds of human ...energy employed in the process of moving building components from demolition to construction sites for reuse. Based on ethnographic data from Switzerland, Italy, and Austria, we qualitatively assess human energy and labour at different stages of circular construction. Through the use of human skills and knowledge, energy is mobilised to evaluate, document, dismantle, design, store, transport, and construct with materials. Our anthropological approach focuses on people and services instead of treating materials and technologies as independent from the workforce handling them. The results underline the complexity and diversity of opinions regarding the value of labour in relation to overall project costs.
Abstract
In accordance with the Paris agreement, the Swiss Climate Strategy (SCS) defines the net-zero target to be reached before 2050, which demands for a thoughtful carbon budget allocation ...between the different contributors. Ongoing normalization tasks are currently defining life cycle carbon budgets at the building scale aligned with the SCS. While recent research has provided promising methodologies to break down a whole building’s carbon budget, SCS-aligned budgets cannot be calculated at the component scale yet. Having the ability to define carbon budgets at the components’ level could support a carbon-responsible design process by reducing the scope of the design problem: the idea is to ensure that the cumulative impact of all the building components (calculated per building energy reference area) remains below the allowed building carbon budget based on SCS targets. This would provide a straightforward link between SCS and carbon budgets at the component scale, a scale at which many decisions need to be taken during the design process. Moreover, based on the set SCS net-zero objectives to be reached by 2050, the carbon budget, whether for buildings or for their components, will have to decrease annually, thereby affecting design flexibility, i.e. the number of design solutions that can still comply with the building’s carbon budget on any specific year. The research presented in this paper aims to provide a framework able to set carbon budgets at the components’ scale and start discussing the consequences of such carbon budgets on façade design flexibility until 2050.
Abstract
The K.118 building on Winterthur’s Lagerplatz, completed in March 2021, has been widely recognised and awarded as an outstanding example for applying the principles of the circular economy ...to architecture. Commissioned by the Swiss pension fund Stiftung Abendrot, the architects Baubüro in situ planned and constructed a building using reclaimed components wherever possible. The planning and construction process was analysed by the Institute of Constructive Design (IKE) at the Zurich University of Applied Sciences (ZHAW) in cooperation with the architects. The study shows that the reuse of building components has great potential for saving resources and reducing greenhouse gas emissions during the construction phase of buildings. In order to use this potential, economic and procedural obstacles created by the framework conditions of today’s construction industry must be tackled.
Abstract
This paper identifies buildings on pathway to meet carbon targets for embodied emissions aligned with global carbon budgets and mitigation pathways. A simplified bottom-up model is used, ...assessing multiple variations of a new construction archetype to identify the main strategies to achieve the targets. The model estimates the quantities of the main components with a few input geometry parameters. Life cycle emissions are then computed based on predefined building components. The reference building is representative of a typical new construction with standard operational values and massive construction. Strategies evaluate design optimization measures, construction techniques, and materials variations. Results show that (1) characteristics and volume of the building play a determining role. The existence and size of underground floors can determine the achievement of todays and future targets. (2) Construction choices can half emissions just by switching from concrete to wood and using natural insulation. (3) Future improvements in the supply chain of materials do not follow the required reduction pathway determined by the Swiss climate strategy. Net-zero compatible buildings are already possible, it is just a matter of making the right choices.
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