Cost‐effectiveness of nearly zero energy detached houses

While new buildings or appropriately carried out refurbishment can already show considerable potential for the reduction of greenhouse gas emissions with the available technology and definite measures, a certain ”last mile“ problem would arise if the requirements were made increasingly stringent toward zero‐energy building: the more saved in the overall balance, the more laborious are the measures that have to be introduced. Using the example of a typical detached house, this article eva luates variants for the building envelope and building supply systems from the viewpoints of energy‐saving and economy, and derives the possible consequences for future requirements and the arrangement of the framework conditions.     

The M1 Energy‐efficiency building Plus – Conclusion of monitoring / Das M1 Energieeffizienzhaus Plus – Abschluss des Monitorings

The M1 energy‐efficiency building Plus was to render practical proof that the advantages of solid construction such as carrying capacity, fire protection and sound protection could be connected to state‐of‐the‐art and future energy efficiency standards in the scope of a pilot project. With simple and thought‐through planning details and a coordinated system technology, energy plus solid houses are no longer merely visions. The M1 project mostly focuses on the claim to economic efficiency and saleability of the product, points out new possibilities for implementation to consumers, planners and executing companies. The house is to document, that the means available now are sufficient to construct a solid building that produces more energy than it consumes. In the technical term of construction physics, the building is targeted at a negative final energy and primary energy consumption. The data presented in this article from the monitoring of the last two years show that a plus energy target can be achieved by “nearly” conventionally built solid buildings. For both years, the M1 pus energy house reached an excess of final and primary energy.     

Compact energy storage enabled by graphenes: Challenges,strategies and progress

Storing as much energy as possible in as compact a space as possible is an ever-increasing concern to deal with the emerging “space anxiety” in electrochemical energy storage (EES) devices like batteries, which is known as “compact energy storage”. Carbons built from graphene units can be used as active electrodes or inactive key materials acting as porous micro- or even nano-reactors that facilitate battery reactions and play a vital role in optimizing the volumetric performance of the electrode and the battery. In this review, we discuss and clarify the key issues and specific strategies for compact energy storage, especially in batteries. The use of shrinkable carbon networks to produce small yet sufficient reaction space together with smooth charge delivery is highlighted as the simplest structure–function-performance relationship when used in supercapacitors and is then extended to overcome problems in compact rechargeable lithium/sodium/potassium batteries. Special concerns about cycling stability, fast charging and safety in compact batteries are discussed in detail. Strategies for compact energy storage ranging from materials to electrodes to batteries are reviewed here to provide guidance for how to produce a compact high energy battery by densifying the electrodes using customized carbon structures.     

Necessary changes in the residential building sector to achieve the climate protection aims for 2030/2050

The aims of German energy and climate policy are ambitious: by 2050, emissions of greenhouse gases should be reduced by at least 80 %, ideally by 95 % compared to 1990. In addition, there are the decisions of the Paris Climate Accord, which intends to limit global warming to considerably less than 2°, better to 1.5°. The building sector as is known plays an important role in the energy transition. The transformation of the building industry and its thermal consumption is of decisive importance for the energy transition as a whole. A study recently commissioned by the alliance for building energy efficiency (geea), the German energy agency (dena) and further industry associations with the title ”Scenarios for a market‐based climate and resources policy 2050 in the building sector“ [1] shows clearly that the ”business as usual“ strategy will not suffice in order to even near the climate protection aims in the building sector. The scientific processing was undertaken by the ewi Energy Research & Scenarios, the institute for building services Dresden (ITG Dresden) and the research institute for thermal insulation (FIW Munich). The scope of this article only deals with the share of residential buildings.     

The Pathway to Intelligence: Using Stimuli‐Responsive Materials as Building Blocks for Constructing Smart and Functional Systems

Systems that are intelligent have the ability to sense their surroundings, analyze, and respond accordingly. In nature, many biological systems are considered intelligent (e.g., humans, animals, and cells). For man‐made systems, artificial intelligence is achieved by massively sophisticated electronic machines (e.g., computers and robots operated by advanced algorithms). On the other hand, freestanding materials (i.e., not tethered to a power supply) are usually passive and static. Hence, herein, the question is asked: can materials be fabricated so that they are intelligent? One promising approach is to use stimuli‐responsive materials; these “smart” materials use the energy supplied by a stimulus available from the surrounding for performing a corresponding action. After decades of research, many interesting stimuli‐responsive materials that can sense and perform smart functions have been developed. Classes of functions discussed include practical functions (e.g., targeting and motion), regulatory functions (e.g., self‐regulation and amplification), and analytical processing functions (e.g., memory and computing). The pathway toward creating truly intelligent materials can involve incorporating a combination of these different types of functions into a single integrated system by using stimuli‐responsive materials as the basic building blocks.     

Autoclaved aerated concrete with sulphate content: an environmentally friendly,durable and recyclable building material

Autoclaved aerated concrete (AAC) contains a small quantity of sulphate. For example, a modern quality class PP2‐0,35 AAC (λ = 0.09 W/(mK)) from Xella contains about five per cent by mass of sulphate in the form of gypsum or anhydrite. The addition of sulphate reduces shrinkage and enhances compressive strength and durability. AAC thus has an almost unrestricted lifetime. Regarding the environmental acceptability of sulphate, dogmatic discussions have been held for years. What is certain: sulphate is not a hazardous substance. Calcium sulphate (gypsum) has been categorised according to the Directive (EC) No. 1272/2008 (CLP) as not hazardous. Xella's voluntary environmental declarations for AAC confirm not only the excellent ecological balance of this product but also the absence of hazardous substances. For construction and demolition (C&D) waste from AAC, disposal is ensured in Germany with landfill class I (“Non‐hazardous waste, domestic waste”). In order to save disposal costs, Xella offers to take back unmixed cutting waste, which arises in the course of new building or refurbishment, without charge at the Ytong‐factories. Xellas long‐term aim is a closed recycling loop for AAC. A collaborative pilot project between Xella and the Otto Dörner Entsorgung GmbH has shown that from the point of view of process and materials technology, production of high‐quality AAC is even possible under utilization of crushed AAC from demolition.     

Standard of nearly zero energy buildings in Germany

The European Union intends to reduce the energy consumption in the building sector. The European Directive 2010/31/EU requires the definition of national standards for nearly zero energy buildings. This article presents a research study supported as part of the research initiative “Zukunft Bau” of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety for the definition of a nearly zero energy building standard for new buildings in Germany. First, the methodology is discussed, then the first results of a variant study on a model building are presented and discussed.     

Energy‐efficient masonry buildings

In line with the general trend to improved energy‐related properties of buildings in massive construction, many massive buildings have been designed and built in recent years, which have proactively observed and also helped to determine the specification of future building standards in Europe. According to [1], the first low‐energy house was built in Kassel in 1986 with an area‐related energy demand for hot water and heating of only 60 kWh/(m²a). The use of massive building materials with low thermal conductivity played a similarly important role in this case to the increasing use of thermal insulation materials and new building services technology using renewable energy sources. Keeping the constructional details simple to build by tradesmen in order to avoid thermal bridging and useless building mistakes was and is still an important practical requirement. With the help of examples, the article demonstrates that monolithic construction is suitable for compliance with current energy‐related requirements and how this is carried out.     

Thermally Driven Transport and Relaxation Switching Self‐Powered Electromagnetic Energy Conversion

Electromagnetic energy radiation is becoming a “health‐killer” of living bodies, especially around industrial transformer substation and electricity pylon. Harvesting, converting, and storing waste energy for recycling are considered the ideal ways to control electromagnetic radiation. However, heat‐generation and temperature‐rising with performance degradation remain big problems. Herein, graphene‐silica xerogel is dissected hierarchically from functions to “genes,” thermally driven relaxation and charge transport, experimentally and theoretically, demonstrating a competitive synergy on energy conversion. A generic approach of “material genes sequencing” is proposed, tactfully transforming the negative effects of heat energy to superiority for switching self‐powered and self‐circulated electromagnetic devices, beneficial for waste energy harvesting, conversion, and storage. Graphene networks with “well‐sequencing genes” (w = P_c/P_p > 0.2) can serve as nanogenerators, thermally promoting electromagnetic wave absorption by 250%, with broadened bandwidth covering the whole investigated frequency. This finding of nonionic energy conversion opens up an unexpected horizon for converting, storing, and reusing waste electromagnetic energy, providing the most promising way for governing electromagnetic pollution with self‐powered and self‐circulated electromagnetic devices.     

Forgotten phenomenon of materials selection and use in geothermal energy applications

Abstract

Pioneering activities of experimental testing and application of engineering experience identified a range of materials and process design guidelines for early geothermal energy plant developments. The success of these guidelines is evidenced by energy plant operation periods extended well beyond design lifetimes, not only in New Zealand but around the world. The efficacy of these guidelines has frequently been tested and in many cases failures have been encountered where the specific conditions of environment-material combinations have not been reliably defined. New R&D continues to build on these guidelines with opportunity for development for more aggressive environments. The historical and evolving “rules of thumb” for materials selection for geothermal energy applications are reviewed and illustrated by experienced successes and failures, the majority of the failures being attributable to readily identifiable forgotten phenomenon.     

Modifizierung organischer Konstruktionswerkstoffe für technische Anwendungen

Modification of Organic Engineering Materials for Technological Applications It is reported about experiments for synthesis of novel reactive, thermotropic, liquid‐crystalline polymers (LCPs) as well as about investigations concerning the use of these LCPs as a blend component for the production of modified polyamide and polyester fibres and their properties. These reactive LCPs are synthetically easy accessible p oly e ster i mid a nhydrides ( PEIA ) bearing lateral as well as terminal anhydride groups. The average number of anhydride groups is variable between 4 and 18. Molecular weights of 30 kg/mol up to 80 kg/mol could be obtained. During mixing of the reactive LC‐PEIAs with polyamide 6 [PA 6] or poly(ethylene terephthalate) [PET] in an extruder under melting conditions both components evidently react within some few minutes to form graft‐block‐copolymers containing on their backbone chains lateral and terminal polyamide respectively polyester blocks. These quickly occurring modification reactions are the base for the industrial application in form of a continuously arrangeable “reactive blending‐spinning‐drawing”‐process. Graft‐block‐copolymers synthesised by this way in the sense of “reactive blending” can be processed together with the corresponding adequate matrix material polyamide 6 or polyester into drawable filaments. After spinning and drawing under suitable conditions lc‐PEIA‐fibrils modified by molecules of the basic polymer with diameters of less than 500 nm are detectable in the resulting filaments. The desired “microphase distribution” of the PA‐modified respectively PET‐modified lc‐PEIA‐macromolecules as the reinforcing system components could be achieved. Moreover these graft‐block‐copolymers built by “reactive blending” in‐situ have a high thermodynamic compatibility because of their chemical similarity to the primary structure of the respective matrix materials resulting in a relatively high reinforcing effect. These both aspects as well as the proceeding orientation of the lc‐PEIA‐microphases by the filament drawing cause, though optimising processes are still remaining, a remarkable increase of the tensile strengths as well as clearly improved initial moduli at a simultaneously raised stretchability of the lc‐PEIA‐modified polyamide and polyester filaments. These effects could be achieved with PEIA‐amounts of lower than 5 percentages by weight .     

Toward an Aqueous Solar Battery: Direct Electrochemical Storage of Solar Energy in Carbon Nitrides

Graphitic carbon nitrides have emerged as an earth‐abundant family of polymeric materials for solar energy conversion. Herein, a 2D cyanamide‐functionalized polyheptazine imide (NCN‐PHI) is reported, which for the first time enables the synergistic coupling of two key functions of energy conversion within one single material: light harvesting and electrical energy storage. Photo‐electrochemical measurements in aqueous electrolytes reveal the underlying mechanism of this “solar battery” material: the charge storage in NCN‐PHI is based on the photoreduction of the carbon nitride backbone and charge compensation is realized by adsorption of alkali metal ions within the NCN‐PHI layers and at the solution interface. The photoreduced carbon nitride can thus be described as a battery anode operating as a pseudocapacitor, which can store light‐induced charge in the form of long‐lived, “trapped” electrons for hours. Importantly, the potential window of this process is not limited by the water reduction reaction due to the high intrinsic overpotential of carbon nitrides for hydrogen evolution, potentially enabling new applications for aqueous batteries. Thus, the feasibility of light‐induced electrical energy storage and release on demand by a one‐component light‐charged battery anode is demonstrated, which provides a sustainable solution to overcome the intermittency of solar radiation.     

Ultrahigh Energy Absorption Multifunctional Spinodal Nanoarchitectures

Nanolattices are promoted as next‐generation multifunctional high‐performance materials, but their mechanical response is limited to extreme strength yet brittleness, or extreme deformability but low strength and stiffness. Ideal impact protection systems require high‐stress plateaus over long deformation ranges to maximize energy absorption. Here, glassy carbon nanospinodals, i.e., nanoarchitectures with spinodal shell topology, combining ultrahigh energy absorption and exceptional strength and stiffness at low weight are presented. Noncatastrophic deformation up to 80% strain, and energy absorption up to one order of magnitude higher than for other nano‐, micro‐, macro‐architectures and solids, and state‐of‐the‐art impact protection structures are shown. At the same time, the strength and stiffness are on par with the most advanced yet brittle nanolattices, demonstrating true multifunctionality. Finite element simulations show that optimized shell thickness‐to‐curvature‐radius ratios suppress catastrophic failure by impeding propagation of dangerously oriented cracks. In contrast to most micro‐ and nano‐architected materials, spinodal architectures may be easily manufacturable on an industrial scale, and may become the next generation of superior cellular materials for structural applications.     

Dry laying of masonry to build demountable,highly energy‐efficient prototype houses – First findings from a currently running research project

In recent decades, energy efficiency has been the priority for masonry buildings in order to keep up with ever more stringent requirements. For the evaluation of the sustainability of building solutions, however, the embodied energy to produce a building and finally to dispose of it at the end of its lifecycle are also important. The energy used for the disposal of a building and the processing of the residues are also important for the overall energy balance since the handling of natural resources is increasingly the centre point of thought and action. A research team at the Chair of Structural Design of TU Dresden has thus been working since 2012 on demountable solutions in masonry, which can be dismantled at the end of a building lifetime and sorted for recycling, which fully complies with the requirement for the reduction of rubbish and waste products. The high precision of block production today permits us to omit the levelling effect of mortar and to build dry buildings in the future, i.e. to do without the bonding principle. The associated strength reductions can be suffered without problems. The appropriate basics of such a dry building method have been researched in a collaboration between the ILEK in Stuttgart and the Xella Technologie‐ und Forschungsgesellschaft mbH in Emstal. In this research project with the abbreviation ”REMOMAB“, the basics of an energy‐efficient dry building method suitable for recycling were collected and made available for practical application. In a follow‐up project, these basics are being implemented and tested on an experimental building. Cost aspects are also to be taken into account and if possible, construction solutions available on the market will be used – modified if necessary. Another aim is for the first time to dismantle such a building and to rebuild it at another location. This is intended to demonstrate that a reuse is possible after dismantling and such a building method can react to changing demands in the housing market.     

Device‐Level Photonic Memories and Logic Applications Using Phase‐Change Materials

Inspired by the great success of fiber optics in ultrafast data transmission, photonic computing is being extensively studied as an alternative to replace or hybridize electronic computers, which are reaching speed and bandwidth limitations. Mimicking and implementing basic computing elements on photonic devices is a first and essential step toward all‐optical computers. Here, an optical pulse‐width modulation (PWM) switching of phase‐change materials on an integrated waveguide is developed, which allows practical implementation of photonic memories and logic devices. It is established that PWM with low peak power is very effective for recrystallization of phase‐change materials, in terms of both energy efficiency and process control. Using this understanding, multilevel photonic memories with complete random accessibility are then implemented. Finally, programmable optical logic devices are demonstrated conceptually and experimentally, with logic “OR” and “NAND” achieved on just a single integrated photonic phase‐change cell. This study provides a practical and elegant technique to optically program photonic phase‐change devices for computing applications.     

Life cycle assessment framework for asphalt pavements: methods to calculate and allocate energy of binder and additives

The construction, maintenance and disposal of asphalt pavements may lead to considerable environmental impacts, in terms of energy use and emissions during the life of the pavement. In order to enable quantification of the potential environmental impacts due to construction, maintenance and disposal of roads, an open life cycle assessment (LCA) framework for the asphalt pavements is presented in this paper. Emphasis was placed on the calculation and allocation of energy used for binder and additives at the project level. It was concluded from this study that when progressing from LCA to its corresponding life cycle cost, the feedstock energy of the binder becomes highly relevant as the cost of the binder will be reflected in its alternative value as fuel. Regarding additives like wax, a framework for energy allocation was suggested. The suggested project level LCA framework was demonstrated in a limited case study of a Swedish asphalt pavement. It was concluded that the asphalt production and transporting materials were the two most energy-consuming processes, emitting most greenhouse gases depending on the fuel type and electricity mix.     

Plasma‐Assisted Synthesis and Surface Modification of Electrode Materials for Renewable Energy

Renewable energy technology has been considered as a “MUST” option to lower the use of fossil fuels for industry and daily life. Designing critical and sophisticated materials is of great importance in order to realize high‐performance energy technology. Typically, efficient synthesis and soft surface modification of nanomaterials are important for energy technology. Therefore, there are increasing demands on the rational design of efficient electrocatalysts or electrode materials, which are the key for scalable and practical electrochemical energy devices. Nevertheless, the development of versatile and cheap strategies is one of the main challenges to achieve the aforementioned goals. Accordingly, plasma technology has recently appeared as an extremely promising alternative for the synthesis and surface modification of nanomaterials for electrochemical devices. Here, the recent progress on the development of nonthermal plasma technology is highlighted for the synthesis and surface modification of advanced electrode materials for renewable energy technology including electrocatalysts for fuel cells, water splitting, metal–air batteries, and electrode materials for batteries and supercapacitors, etc.     

Shock Exfoliation of Graphene Fluoride in Microwave

An unprecedented microwave‐based strategy is developed to facilitate solid‐phase, instantaneous delamination and decomposition of graphite fluoride (GF) into few‐layer, partially fluorinated graphene. The shock reaction occurs (and completes in few seconds) under microwave irradiation upon exposing GF to either “microwave‐induced plasma” generated in vacuum or “catalyst effect” caused by intense sparking of graphite at ambient conditions. A detailed analysis of the structural and compositional transformations in these processes indicates that the GF experiences considerable exfoliation and defluorination, during which sp²‐bonded carbon is partially recovered despite significant structural defects being introduced. The exfoliated fluorinated graphene shows excellent electrochemical performance as anode materials in potassium ion batteries and as catalysts for the conversion of O₂ to H₂O₂. This simple and scalable method requires minimal energy input and does not involve the use of other chemicals, which is attractive for extensive research in fluorine‐containing graphene and its derivatives in laboratories and industrial applications.     

“Changes or not” is the question: The meaning of posttraumatic stress reactions one year after the Taiwan chi‐chi earthquake

Abstract

“Resource gains” and “resource losses”, based on the Conservation of Resources Theory, are equally important in trauma recovery. This study was to investigate their influence on the severity of post‐traumatic stress reactions and psychosocial adjustment patterns of the residents in two severely damaged townships. Five hundred and fifty six adults (157 males and 399 females) were assessed in terms of objective and subjective threat (of losses), subjective evaluations of changes in life domains and coping resources, and severity of post‐traumatic symptoms one year after the Earthquake. The results showed that those who reported “No Change”, compared to those were either “better” or “worse”, had the least severity of PTSD symptoms. The subjective evaluation of changes in life domains and subjective threat were positively associated with changes in coping resources, but not the severity of PTSD symptoms. Results are discussed from the viewpoint of Cox's Stress Model and Wu's Life‐Energy Stress Model, and it is suggested that successful coping might be accompanied by PTSD symptoms. Reconsideration and expansion of the meaning of “changed vs. unchanged” following a traumatic experience is also discussed.