This paper compares different strategies to transform the heating sector into a future 100% renewable energy solution. It focuses on the consequences for infrastructures in terms of grids and storage ...across the electricity, gas and heating sectors. The hypothesis is that these consequences are rarely taken into proper consideration, even though the costs are significant and differ substantially between the alternative pathways. While the smart grid scenarios are based on electricity as an energy carrier, the “smart energy systems” approach is based on a cross-sectoral use of all grids. Using Denmark as a case, this paper shows how the current gas and district heating grids each have twice the capacity of the electricity distribution grid. Moreover, the existing gas and thermal storage capacities are substantially higher and the additional future capacities are more affordable than within the electricity sector. The conclusion is that the “smart grid” pathway requires a 2–4 times expansion of the electricity grid and significant investments in electricity storage capacities, while the “smart energy systems” pathway can be implemented with relatively few investments in affordable minor expansions of existing grids and storage capacities.
•Comparing different strategies to transform the heating sector to 100% renewables.•Comparing a Smart Energy Systems to a Smart Grid approach.•Focus is on the consequences for storage and grid infrastructures.•Smart grids may require significant expansion of grid and storage infrastructures.•Smart energy systems can succeed within existing grid and storage infrastructures.
This review article presents a description of contemporary developments and findings related to the different elements needed in future 4th generation district heating systems (4GDH). Unlike the ...first three generations of district heating, the development of 4GDH involves meeting the challenge of more energy efficient buildings as well as the integration of district heating into a future smart energy system based on renewable energy sources. Following a review of recent 4GDH research, the article quantifies the costs and benefits of 4GDH in future sustainable energy systems. Costs involve an upgrade of heating systems and of the operation of the distribution grids, while benefits are lower grid losses, a better utilization of low-temperature heat sources and improved efficiency in the production compared to previous district heating systems. It is quantified how benefits exceed costs by a safe margin with the benefits of systems integration being the most important.
•Provides a review of 4th Generation District Heating (4GDH) in scientific papers.•Shows how 4GDH is an important integrated part of future sustainable energy systems.•Quantifies costs and benefits of 4GDH in a future sustainable energy system.•Shows how benefits exceed costs by a safe margin.•Shows the significant benefits of systems integration.
iCourts is a research center for international courts and international law at the Faculty of Law in Copenhagen. The purpose of this book is to show how the establishment, operation and ambitions of ...a research center can impact a whole field of research.
Further development and upscaling of the Solid Oxide fuel and electrolysis Cell (SOCs) technologies would significantly benefit from improvement of their mechanical robustness. In this work, ...microstructure, crystalline phase composition, fracture toughness and susceptibility to low- and high-temperature degradation of six different Ni(O)‒Zirconia fuel electrode supports, manufactured from six different stabilized zirconia compounds, are investigated.
In the oxidized state, tetragonal zirconia-based supports have higher fracture toughness than cubic zirconia-based substrate, due to the transformation toughening effect and a finer grained microstructure. The NiO‒1.5CeO2 4.5YO1.5-SZ support exhibits the highest fracture toughness, showing a 30 and 10 % improvement compared to the state-of-the-art NiO‒5.8YO1.5-SZ support at room temperature and 800 °C, respectively. In the reduced state on the other hand, the tetragonal and cubic zirconia-based substrates have comparable fracture toughness. The Ceria-Yttria co-doped materials possess superior resistance to hydrothermal degradation due to the stabilizing effect of Ce3+ formed during reduction.
In a late Swedish Viking Age population dating from around 10th-12th century AD, the prevalence, distribution and location of dental caries were studied. Tooth wear, other dental pathology and ...anatomical variations were identified and recorded clinically and radiographically. A total of 3293 teeth were analyzed from 171 individuals with complete and partial dentitions, of which 133 were permanent and 38 deciduous/mixed dentition. The dentitions were studied clinically, using a dental probe under a strong light source, and radiographs were taken for 18 of the individuals to verify and complement the clinical caries registration. Almost half the population, 83 of 171 individuals (49%), had at least one carious lesion. All individuals with deciduous or mixed dentitions were caries-free. The number of teeth affected by caries among adults was 424 (13%) and the surface most susceptible to caries was the root surface. The tooth most commonly affected by caries was the first mandibular molar. Other findings included apical infections, which were detected clinically in 4% of the teeth, and one case of filed front teeth. The findings gave a unique understanding of life and death in this early Christian Viking community and indicated that it was common to suffer from dental caries, tooth loss, infections of dental origin and tooth pain. These Vikings also manipulated their teeth through filing, tooth picking and other occupational behaviors.
Abstract
Due to the complexity of heterogeneous catalysts, identification of active sites and the ways for their experimental design are not inherently straightforward but important for tailored ...catalyst preparation. The present study reveals the active sites for efficient C–H bond activation in C
1
–C
4
alkanes over ZrO
2
free of any metals or metal oxides usually catalysing this reaction. Quantum chemical calculations suggest that two Zr cations located at an oxygen vacancy are responsible for the homolytic C–H bond dissociation. This pathway differs from that reported for other metal oxides used for alkane activation, where metal cation and neighbouring lattice oxygen form the active site. The concentration of anion vacancies in ZrO
2
can be controlled through adjusting the crystallite size. Accordingly designed ZrO
2
shows industrially relevant activity and durability in non-oxidative propane dehydrogenation and performs superior to state-of-the-art catalysts possessing Pt, CrO
x
, GaO
x
or VO
x
species.
The continuous introduction of renewable electricity and increased consumption through electrification of the transport and heating sector challenges grid stability. This study investigates load ...shifting through demand side management as a solution. We present a four-month experimental study of a low-complexity, hierarchical Model Predictive Control approach for demand side management in a near-zero emission occupied single-family house in Denmark. The control algorithm uses a price signal, weather forecast, a single-zone building model, and a non-linear heat pump efficiency model to generate a space-heating schedule. The weather-compensated, commercial heat pump is made to act smart grid-ready through outdoor temperature input override to enable heat boosting and forced stops to accommodate the heating schedule. The cost reduction from the controller ranged from 2-17% depending on the chosen comfort level. The experiment demonstrates that load shifting is feasible and cost-effective, even without energy storage, and that the current price scheme provides an incentive for Danish end-consumers to shift heating loads. However, issues related to controlling the heat pump through input-manipulation were identified, and the authors propose a more promising path forward involving coordination with manufacturers and regulators to make commercial heat pumps truly smart grid-ready.
•We conduct a long-term control demonstration in a real occupied single-family house with heat pump and floor heating.•The demonstration employs a price responsive, mixed-Integer, hierarchical model predictive control algorithm.•The domestic air-to-water heat pump is retrofitted to be smart-grid-ready.•We demonstrate the actual load shifting potential of the heat pump in a nearly zero emission building.•Results show that a single-zone model based on an average indoor temperature can maintain a comfortable indoor environment.
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•Electron beam melting and field-assisted sintering were coupled to fabricate load-bearing Ti6Al4V-BaTiO3 piezoelectric bone scaffolds.•Images of sintered composite scaffold interface ...revealed that the Ti6Al4V cylindrical lattice structure bounded with BaTiO3 matrix without its major deformation.•The fabricated Ti6Al4V-BaTiO3 scaffold showed a piezoelectric response of (0.63 ± 0.12) pC/N without poling which increased to (4.92 ± 0.75) pC/N after corona poling.•Nanoindentation values reveal that Ti6Al4V is the harder and stiffer part of the Ti6Al4V-BaTiO3 scaffold.
A critical-size bone defect in load-bearing areas is a challenging clinical problem in orthopaedic surgery. Titanium alloy (Ti6Al4V) scaffolds have advantages because of their biomechanical stability but lack electrical activity, which hinders their further use. This work is focused on the fabrication of Ti6Al4V-Barium Titanate (BaTiO3) bulk composite scaffolds to combine the biomechanical stability of Ti6Al4V with electrical activity through BaTiO3. For the first time, a hollow cylindrical Ti6Al4V is additively manufactured by electron beam melting and combined with piezoelectric BaTiO3 powder for joint processing in field-assisted sintering. Scanning electron microscope images on the interface of the Ti6Al4V-BaTiO3 composite scaffold showed that after sintering, the Ti6Al4V lattice structure bounded with BaTiO3 matrix without its major deformation. The Ti6Al4V-BaTiO3 scaffold had average piezoelectric constants of (0.63 ± 0.12) pC/N directly after sintering due to partial dipole alignment of the BaTiO3 tetragonal phase, which increased to (4.92 ± 0.75) pC/N after a successful corona poling. Moreover, the nanoindentation values of Ti6Al4V exhibited an average hardness and Young’s modulus of (5.9 ± 0.9) GPa and (130 ± 14) GPa, and BaTiO3 showed (4.0 ± 0.6) GPa and (106 ± 10) GPa, respectively. It reveals that the Ti6Al4V is the harder and stiffer part in the Ti6Al4V-BaTiO3 composite scaffold. Such a scaffold has the potential to treat critical-size bone defects in load-bearing areas and guide tissue regeneration by physical stimulation.
Aims
To evaluate the prevalence and severity of diabetic retinopathy including macular oedema in pregnant women with diabetes and to identify women in whom the frequency of retinal screening can be ...reduced to minimize the burden of health care visits.
Methods
A cohort study of 348 women with pre‐existing diabetes were routinely screened with retinal photo in early (12 weeks) and late pregnancy (27 weeks). Diabetic retinopathy was classified in five stages in accordance with National Danish Guidelines based on the eye with the highest retinopathy level. Sight‐threatening retinopathy was defined as the presence of proliferative retinopathy and/or clinically significant macular oedema (CSMO).
Results
Retinopathy was present in 52% (116/223) vs. 14% (17/125), with sight‐threatening retinopathy in 16% (35/223) vs. 6% (7/125) of women with type 1 and type 2, respectively. Women without retinopathy in early and late pregnancy were characterized by shorter diabetes duration (p < 0.0001 and p = 0.008) and predominance of type 2 diabetes. Amongst the 50% (175/348) of the cohort having no retinopathy in early pregnancy and HbA1c<53 mmol/mol (7.0%), none developed sight‐threatening retinopathy and 94% (165/175) remained without any retinopathy during pregnancy. Development of sight‐threatening retinopathy was mainly observed in women with retinopathy in early pregnancy. Treatment for sight‐threatening retinopathy was given to a minority (2.7 and 2.4%, respectively).
Conclusion
Good glycaemic control and no retinopathy was seen in a large proportion of women in early pregnancy and none of these women developed sight‐threatening retinopathy. The frequency of retinal screening can probably be safely reduced during pregnancy in these women.
•Exploratory analysis of manufacturing reshoring to Norway.•Highlights the potential of advanced technology as driver for reshoring.•Technologies must be connected to existing intra- and extra-firm ...capabilities.•Develops an analytical framework based on key global production network concepts.•Presents a nuanced perspective on strategic coupling as temporal and partial.
The explorative paper investigates the drivers for the emerging trend of manufacturing reshoring from low- to high-cost locations. To date research on the reshoring phenomenon has been dominated by micro-level analyses of firms in supply chain management and reported in international business literature. The paper introduces reshoring as a research topic to the economic geography research field, arguing that it connects with the broader topic of regional development. To provide a better understanding of the reshoring phenomenon and to test the applicability of the global production network (GPN) framework in the analysis of the phenomenon, the authors analyse the reshoring of nine of Norwegian manufacturing firms. With the multiscalar lens provided by the GPN framework, the authors find that the implementation of advanced manufacturing technologies is a driver for manufacturing reshoring, but only when matched with key regional assets such as automation knowledge and competence, key human capital, and region-specific manufacturing competence. Additionally, reshoring decisions are influenced by extra-regional factors such as changes in the global economy and market fluctuations. Furthermore, the paper provides a refined conceptualization of strategic coupling processes by including acts of disinvestments and reinvestments performed by actors within global production networks. Accordingly, the authors advocate a more nuanced understanding, defined as partial coupling processes, in contrast to the predominant understanding of coupling processes as ruptures. This refined conceptualization provides enhanced analytical purchase when studying the reshoring phenomenon, as it illuminates the complexity of firms’ production and sourcing strategies and the resulting implications for the economic landscape.
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