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Hydrogen is often suggested as a universal fuel that can replace fossil fuels. This paper analyses the feasibility of direct hydrogen utilisation in all energy sectors in a 100% renewable energy system for Europe in 2050 using hour-by-hour energy system analysis. Our results show that using hydrogen for heating purposes has high costs and low energy efficiency. Hydrogen for electricity production is beneficial only in limited quantities to restrict biomass consumption, but increases the system costs due to losses. The transport sector results show that hydrogen is an expensive alternative to liquid e-fuels and electrified transport due to high infrastructure costs and respectively low energy efficiency. The industry sector may benefit from hydrogen to reduce biomass at a lower cost than in the other energy sectors, but electrification and e-methane may be more feasible. Seen from a systems perspective, hydrogen will play a key role in future renewable energy systems, but primarily as e-fuel feedstock rather than direct end-fuel in the hard-to-abate sectors.

Artiklen tager afsæt i en forståelsesramme informeret af teori om paradokser i organisering. På den baggrund tydeliggøres det, hvordan deltagere i arbejdsfællesskaber stilles overfor grundlæggende dilemmaer, som kalder på det, vi benævner dilemmatænkning. Formålet er at undersøge, hvordan dilemmatænkning, som en praksisorienteret metode, kan bidrage med en lærende respons på komplekse problemstillinger, der i øvrigt udfordrer det psykosociale og organisatoriske arbejdsmiljø. Udgangspunktet er, at det psykosociale arbejdsmiljø er præget af komplekse problemstillinger, der kalder på løbende undersøgelse og læring. Gennem en case på en hospitalsafdeling, hvor sygeplejersker håndterer kronisk syge patienter, viser artiklen, at det i et samspil mellem sygeplejerskerne og forskerne bliver muligt at genfortolke konkret oplevede belastningsmæssige problemstillinger som dilemmaer, der ikke kan finde en Enten-Eller-løsning. Gennem en kollektiv og lærende dialog udforsker sygeplejerskerne dilemmaerne i lyset af de paradokser, som er indlejret i den sociotekniske organisering. Dilemmatænkning bidrager dermed til afindividualisering og en øget fælles forståelse for de indlejrede forskellige muligheder, der er i at tilgå opgaverne.

With the Danish government's goals of decreasing 70% of CO2 emissions by 2030 and reaching a fully decarbonised society in the years after, this paper aims to identify the role of sustainable bioenergy in achieving this goal. The methodology and approach presented are relevant for other countries heading in the same direction. The focus is on strategies to further develop the sustainable biomass resources and conversion technologies within energy and transport paired with CCUS (carbon capture utilisation and storage) to coordinate with other sectors and achieve a fully decarbonised society. By using hourly energy system modelling and a Smart Energy Systems approach, it is possible to create a robust multiple technology strategy and keep the sustainable bioenergy levels. The results are presented as principles and guidelines on how to include the use of sustainable biomass in the individual country as an integrated part of global decarbonisation.

Current standard wound care involves dressings that provide moisture and protection; however, dressings providing active healing are still scarce and expensive. We aimed to develop an ecologically sustainable 3D printed bioactive hydrogel-based topical wound dressing targeting healing of hard-to-heal wounds, such as chronic or burn wounds, which are low on exudate. To this end, we developed a formulation composed of renewable marine components; purified extract from unfertilized salmon roe (heat-treated X, HTX), alginate from brown seaweed, and nanocellulose from tunicates. HTX is believed to facilitate the wound healing process. The components were successfully formulated into a 3D printable ink that was used to create a hydrogel lattice structure. The 3D printed hydrogel showed a HTX release profile enhancing pro-collagen I alpha 1 production in cell culture with potential of promoting wound closure rates. The dressing has recently been tested on burn wounds in Göttingen minipigs and shows accelerated wound closure and reduced inflammation. This paper describes the dressings development, mechanical properties, bioactivity, and safety.

This study develops scenarios aiming to transition the Chilean energy system in 2050 to 100% renewable energy; taking into account local resource potentials, demands, cross-sectoral integration of the electricity, heating, transport, and industrial sectors, and synergies in their related infrastructures. The energy system model EnergyPLAN is used to simulate the hourly operation of the energy system. The relationship between potential CO2 emissions reductions and relative costs is estimated using marginal abatement cost curves with the EPLANoptMAC tool to assess the optimal sequence of capacity expansion and carbon abatement alternatives. The analysis demonstrates that it is possible to carry out this transition from a technical perspective more efficiently than what is proposed with current national scenarios while still aligning with climate neutrality targets; and that, in different phases of the Chilean energy transition, specific options could be prioritized based on an improved balance between carbon abatement and costs.

CO2 hydrogenation to methanol was investigated over CuZnIn/MZrOx (M = La, Y or Ti) catalysts at 20 bar and at 225 °C with the purpose to elucidate the effects of the metal oxide promoter for ZrO2 and InOx for CuZnOx on reaction scheme of product formation, catalyst activity and product selectivity. Although the additives do not affect the overall scheme of product formation, they are relevant for the rates of direct CO2 conversion into methanol or CO and of methanol decomposition to CO and H2. This is due to their influence on dispersion of CuOx and the strength of basic sites for CO2 adsorption. Highly dispersed CuOx species are essential for CO2 conversion but not for methanol selectivity. The selectivity is improved over polymerized CuOx with strong basicity. This catalyst property can be controlled through promoting of (i) ZrO2 with La2O3/Y2O3 or (ii) CuZnOx with InOx. The latter promoter is crucial for hindering the undesired methanol decomposition to carbon monoxide.

The synthesis of vitamin precursors via alkyne semi-hydrogenation has been achieved with a lead- and palladium-free catalyst.

Today, coal is responsible for 40% of annual CO2 emissions. At the same time, global warming causes climate changes accompanied with catastrophic meteorological phenomena all over the world. After the 2015 Paris Agriment many countries set ambitious energy policy to reduce the annual greenhouse gas emission. The 2021 UN Climate Change Conference, COP26 - Glasgow, ended with the adoption of a less stringent resolution than some anticipated: countries only agreed to “phase down” rather than “phase out” coal. Is possible the realization of the Paris Agreement after COP-26? For achieving this ambitious targets in such conditions, the support of the multi-disciplinary scientific knowledge is needed. Since 2002 a series of SDEWES Conferences were founded. This paper presents an overview of published researches in special issues of leading journals dedicated to the series SDEWES Conferences, including also the papers in current special issue presented on Conferences held in 2020: 2nd LA SDEWES Conference - Buenos Aires, 1st AP SDEWES Conference - Gold Coast, 4th SEE SDEWES Conference - Sarajevo and 15th SDEWES Conference - Cologne. The focus is on five main fields: (1) energy system analysis ; (2) energy savings in the building sector ; (3) district heating ; (4) electrification of transport and (5) water-energy nexus. Undoubtedly, the researches presented in this special issue as well as in previous ones, will contribute to the achievement of the goals of the Paris Agreement in difficult conditions after COP26.

Partial-thickness thermal burn wounds are characterized by a prolonged inflammatory response, oxidative stress, tissue damage, and secondary necrosis. An optimal dressing for burn wounds would reduce inflammation and oxidative stress while providing a moist, absorbent, and protective cover. We have developed an extract from unfertilized salmon roe containing components with potential anti-inflammatory and antioxidative properties, called HTX. HTX has been combined with alginate from brown algae and nanocellulose from tunicates, and 3D printed into a solid hydrogel wound dressing called Collex. Here, Collex was tested on partial thickness burn wounds in Göttingen minipigs compared to Jelonet, and a variant of Collex without HTX. We found that dermal treatment of burn wounds with Collex resulted in accelerated healing at a majority of measured points over 23 days, compared to treatment with Jelonet. In comparison to Collex without HTX, Collex enhanced healing in the first week after trauma where wound progression was pronounced. Notably, Collex reduced the inflammatory response in the early post-injury phase. The anti-inflammatory response of Collex was investigated in more detail on activated M1 macrophages. We found that Collex, as well as HTX alone, significantly reduced the secretion of pro-inflammatory interleukin-1β as well as intracellular levels of oxidative stress. The results from this study indicate that Collex is a potent dressing for the treatment of burn wounds, with the anti-inflammatory effect of HTX beneficial in the initial phase, and the moist qualities of the hydrogel favorable both in the initial and the proceeding proliferative phase of wound healing.

The kind of alkali metal in ferrous oxalate dihydrate affect the concentration and spatial distribution of iron carbides formed in situ in CO2 hydrogenation. These structural changes impact the rate of CH4 formation from CO2 but not from CO.

Following the 2015 Paris Agreement and other agreements which have been signed after, sustainable energy development is becoming the major goal in many countries. EU have set the targets to reduce the annual greenhouse gas emission by 40% in 2030 and 80% for 2050 compared with 1990 levels. For achieving this ambitious energy policy, three major technological changes are available: energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Also, for realization cited three major technological changes the support of the multi-disciplinary scientific knowledge is needed. Therefore, from the beginning of the 21st century, since 2002, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences were founded. This paper presents an overview of published researches in special issues of leading journals dedicated to the series SDEWES Conferences, including also the papers in current special issue. The focus is on five main fields: (1) energy policy and analysis of smart energy systems; (2) energy savings in the building sector; (3) co/polygeneration - integrated heating, cooling and electricity systems and district heating; (4) biomass for energy; and (5) measurement of energo-environmental sustainability of processes and systems. Researchers are focused on the development of methods, policies and technologies for both efficient production of energy, mainly from renewable sources, and consumption in industry, buildings and transport. Undoubtedly, the researches presented in the papers in this special issue as well as in previous ones, dedicated to SDEWES conferences, will contribute to the promotion of sustainable development and thus to the achievement of the goals of the Paris Agreement.

Limiting the degradation of solid oxide fuel cells is an important challenge for their widespread use and commercialization. The computational expense of long-term simulation of a full stack with conventional models is immense. In this study, we present a multiscale three-dimensional model of a degrading full stack of solid oxide cells, where we integrate degradation phenomena of nickel particle coarsening in the anode electrode, chromium poisoning of the cathode electrode, and oxidation of the interconnect into a multiscale model of the stack. This approach makes this type of simulation computationally feasible, and 38 thousand hours of the stack operation can be simulated in 1 h and 15 min on a high-end workstation. Hereby one can start to explore the optimum operating conditions for a range of parameters. The model is validated with experimental data from an 18-cell Julich Mark-F stack experiment and predicts common trends reported in the literature for evolutions of the stack performance, degradation phenomena, and the related model variables. Moreover, it captures how different regimes in the full stack degrades at different rates and how the various degradation phenomena interact over time. The model is used to investigate the effects of galvanostatic and potentiostatic operation modes, operating conditions, and flow configurations on the long-term performance of the stack. Results demonstrate, as expected, that potentiostatic operation mode, moderate temperature, lower load current, and counter-flow configuration improve the long-term performance of the stack.

This paper presents a strategy for achieving a fully decarbonized Danish energy system (including transport and industry) in 2045. The strategy could also be relevant for most countries at a global level. The energy system analysis includes hour-by-hour computer simulations leading to the design of a Smart Energy System with the ability to balance all sectors of the complete energy system. In the analysis, issues such as international shipping and aviation, the sustainable use of biomass, and the exchange of electricity and gas with neighbouring countries are all considered. Moreover, the energy system is coordinated with other sectors to achieve a fully decarbonized society. Finally, the size of the employment impact of investing in decarbonizing the Danish economy is discussed.

Although energy system models have become more complex, it does not necessarily mean that they are better suited to answer the questions, or address the challenges, faced by decision- and policymakers. In this report, we aim to tackle such critical issues and challenges of the European energy transition towards climate neutrality by 2050, with the user-driven updated SENTINEL modelling ensemble. Specifically, we showcase the applicability and usefulness of the SENTINEL modelling suite in the context of three case studies, a. a Continental level case study (European Union, Iceland, Norway, Switzerland, the United Kingdom, and some Balkan countries), b. a Regional level case study (Nordic countries), and c. a National level case study (Greece). Specifically, this report provides details on input data, as well as model linkages and results, and serves two purposes. It provides (i). detailed specifications for the application of the SENTINEL models in the context of policy-relevant scenarios and energy and climate targets, and (ii). answers to stakeholders’ critical research questions through scientific evidence from the SENTINEL models. Modelling results relevant to the power sector’s transformation showcase that the transition to a low-carbon power sector would need to consider potential lock-ins to intermediate technologies, such as natural gas, which could decrease European energy security, and increase import dependency. On the demand side, the potential for energy demand reduction in the European transport sector is large, while the industry sector presents inertia. However, electrification in both sectors is expected to become significant, which would decrease fossil-fuel extraction and use, and consequently direct fossil carbon dioxide emissions. Furthermore, achieving decarbonisation in the building sector by 2050 is possible but would require a higher annual rate of high-efficiency renovations and new buildings than currently prescribed, which would also require strong political support to accelerate the implementation of measures. Overall, increasing electrification across all demand sectors is expected to cause changes in total and hourly power demand, which could potentially increase peak demand. In this context, sector coupling can provide the necessary flexibility to the power system and ensure an adequate balance between energy supply and demand. Regarding the environmental impacts of the energy transition, we highlight that greenhouse-gas emission reductions should not be looked at solely, as the effect of the energy transition on other aspects (such as for example, human toxicity, human health, water depletion, particulate matter formation, terrestrial acidification, etc.) may be negative. On top of that, risks regarding the availability of critical raw materials should be taken into account to avoid scarcity of raw materials required for key new renewable technologies. Finally, on the socio-economic aspect, we show that although a people-powered, decentralised energy system has the highest system cost, it has the largest economy-wide welfare benefits, including positive aggregate EU27+ employment effects by 2030 and by 2050., The authors would like to acknowledge the support from the EC. The authors would like to thank the SENTINEL colleagues that contributed to specific sections relevant to their models' application to the SENTINEL case studies. The content of this report is the sole responsibility of its authors and does not necessary reflect the views of the EC.

Underwater rugby is a team sport where players try to score points with a negatively buoyant ball while submerged in a swimming pool. Reports of syncope incidents at the Swedish Championships led to us to investigate end-tidal oxygen and carbon dioxide levels during simulated match play.Eight male underwater rugby club players of varying experience participated. Repetitive measurements were made while players were defending during simulated match play. Each time a player surfaced they exhaled through a mouthpiece connected to a flow meter and a gas analyzer to measure tidal volume, PETO2 and PETCO2.Measurements were made over 12 dives, with an average dive duration of 18.5 seconds. The mean maximal PETCO2 across the eight participants was 10.0 kPa (~75 mmHg) (range, 9.1-11.7 [~68-88]). The corresponding mean minimum PETO2 was 7.6 kPa (~57 mmHg) (6.3-10.4 [~47-78)). PETCO2 drifted upward, with the mean upward change from the first to last dive for each participant being +1.8 (~13.5 mmHg) (SD 1.74) kPa. A similar trend for PETO2 was not detected, with a mean change of -0.1 (~0.75 mmHg) (SD 3.79) kPa.Despite high PETCO2 values that were close to narcotic being recorded, these players seemed to regulate their urge to breathe based on hypoxia rather than hypercapnia.

A successful Green Transition requires efficient, and cost competitive technologies for converting & storing energy from renewable sources and for providing energy to the stationary and the transport sector. Solid oxide fuel cells and electrolysis (SOFC, SOE - SOC) provide high efficiencies for electricity generation and production of storage media / fuels, respectively. In addition, they are flexible and versatile, which makes them attractive in many different application areas and energy scenarios. Research on solid oxide concepts has a long tradition at the Department of Energy Conversion and Storage (DTU Energy) of the Technical University of Denmark. It spans from fundamental topics such as materials & electrode development over methodology development for example in micro structural & electrochemical characterization, up to the applied level, where integration of SOC with up- and down-stream processes becomes important. Significant funding from National and European programs supported this research. The presentation will introduce highlights of recent achievements in the areas of (i) materials & electrode development to reach higher activity and better durability, (ii) cell & stack development for lowering costs and increasing robustness, (iii) power to X concepts with special emphasis on X= fuels, (iv) lifetime & diagnostics approaches for accelerating durability studies, and (v) modelling from materials to stack levels aiding lifetime evaluation and designing of stacks & systems. (i) Materials & electrode development: With the aim to reduce use of critical raw materials in SOCs, Co-free oxygen electrodes were developed based on lanthanum, strontium, and iron containing perovskite materials (LSF) applying a nano engineered hybrid catalyst coating via co-infiltration. The electrodes were integrated into cells and a high electro catalytic activity was achieved leading to power densities of ca. 1 W/cm2 in SOFC mode. Such cells with CGO infiltrated Ni/YSZ fuel electrode allowed for a stable electrolysis operation at 650 oC and -0.5 A/cm2 with a voltage close to 1.3 V. (ii) Cell & stack development: A novel, metal-based monolithic concept for SOFC stacks was developed. It is based on tape casting & lamination to build a monolithic structure thereby combining interconnect and gas distribution into one layer. Electro catalytic materials are infiltrated after sintering. This concept allows for an increase of the power density >5 kW/l, a decrease of materials costs by a factor of ca. 4-5 as compared to conventional stacks, and robustness for cycling operations. (iii) Power to X concepts: A novel and efficient route for producing green methanol was demonstrated by use of residue from the agriculture. A 6 kW SOEC stack unit produced hydrogen, which was combined with syngas from a thermal gasifier operating on straw in a down-stream methanol reactor. Methanol is considered a promising green fuel for the shipping sector. The same applies for ammonia. SOFC anodes catalyze the cracking of ammonia. This endothermal process can be integrated and tailored with the exothermal hydrogen oxidation in the electrode. The cracking of ammonia was studied on materials and stack level. (iv) Lifetime & diagnostics approaches: The long lifetimes –both required and achieved - of mature SOC generations make it necessary to develop new approaches for degradation studies and lifetime assessment. With the aim to harvest gained results from single cell durability testing over the last ca. 20 years at DTU Energy, a database was established allowing for a new evaluation of durability behavior. The database makes it possible to apply machine learning routines to reveal linear and non-linear correlations and single & combined effects of operating parameters on durability over a large range of data. The aim is to identify accelerating testing approaches and establish lifetime prediction. (v) Modelling: To further optimize the operation of an SOC and avoid degradation, a time dependent 3D stack model describing the degradation over the entire lifetime was developed. For this to be computational feasible, the model was built using the multi-scale, multi-physics homogenization concept, making it possible to simulate 40,000 hours of operation for a full 3D stack in one hour and 15 minutes. Same modelling concept was also utilized to describe local mechanical failures by use of a sub-model for the mechanical stress concentrations near assembly points inside the stack.

Summary Objectives To compare treatment time, patients’ perceptions during orthodontic treatment, dental fear and side effects, between open and closed surgical exposures in patients with palatally displaced canines (PDCs). Trial design Multicentre, randomized controlled trial, with random 1:1 allocation of two parallel groups. Materials and methods One hundred and twenty patients from three different orthodontic centres were randomized into one of the two intervention arms, open or closed surgical exposure. Both techniques had mucoperiosteal flaps raised and bone removed above the PDCs. In open exposure, tissue was removed above the canine, and glass ionomer – reaching above soft tissue – was built on the crown. The canine was then left to erupt spontaneously, prior to orthodontic alignment. At closed exposure, a chain was bonded to the canine and orthodontic traction was applied under the mucosa until eruption. Orthodontic alignment of the canines was undertaken after eruption into the oral cavity, with fixed appliances in both groups. All participants were treated according to intention to treat (ITT). Blinding Due to the nature of this trial, only outcome assessors could be blinded to the intervention group. Results One hundred and seventeen patients completed the trial. All PDCs were successfully aligned. Total treatment time was equal in the two techniques, mean difference −0.1 months (95% CI −3.2 to 2.9, P = 0.93). The closed group experienced more pain and discomfort during the active orthodontic traction. Dental fear, root resorption and periodontal status did not show any clinically significant differences between the groups. Generalizability Results of this randomized controlled trial (RCT) can be generalized only to a similar population aged 9–16 years, if exclusion criteria are met. Conclusion The closed exposure group experienced more pain and discomfort mostly during active orthodontic traction. All other studied outcomes were similar between the two exposure groups. Clinical Trial registration ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

Objective: Seasonal and non-seasonal depression are prevalent conditions in visual impairment (VI). We assessed the effects and side effects of light therapy in persons with severe VI/blindness who experienced recurrent depressive symptoms in winter corresponding to seasonal affective disorder (SAD) or subsyndromal SAD (sSAD). Results: We included 18 persons (11 with severe VI, 3 with light perception and 4 with no light perception) who met screening criteria for sSAD/SAD in a single-arm, assessor-blinded trial of 6 weeks light therapy. In the 12 persons who completed the 6 weeks of treatment, the post-treatment depression score was reduced (p < 0.001), and subjective wellbeing (p = 0.01) and sleep quality were improved (p = 0.03). In 6/12 participants (50%), the post-treatment depression score was below the cut-off set for remission. In four participants with VI, side effects (glare or transiently altered visual function) led to dropout or exclusion. Conclusion: Light therapy was associated with a reduction in depressive symptoms in persons with severe VI/blindness. Eye safety remains a concern in persons with residual sight.

In order to support European-wide transition of heating systems, it is useful to categorise the types of transitions that are necessary. Coherent actions are needed at (supra-)national level to support transition aligned with the energy efficiency first principle and long-term development of a smart energy system. Owing to the decentralised nature of heating, transition must also reflect particular local circumstances. This article uses commonalities between countries to create a representative typology, which can suggest appropriate policies for transition. Following the energy efficiency first principle, transition should include supply-side and demand-side efficiency to ensure coherency and efficient use of resources. Their comparative analysis supports implementing the energy efficiency first principle locally, and a more coherent European strategy for the heating sector. Methodologically, 14 national heating strategies are considered which include current and future energy system developments, demand- and supply side energy efficiency, hectare-level thermal mapping and energy system analysis. Four heat sector types are proposed and discussed. These are (1) extant heat planning traditions, aiming for more efficiency and integration; (2) extant heating infrastructure, aiming to refurbish and upgrade both building stock and existing heating infrastructure; (3) existing gas infrastructure, requiring radical transition; (4) and those without strong historic heat planning traditions.

A detailed study was carried out to elucidate the factors affecting the activity and, particularly, selectivity of bare Al2O3 in the non-oxidative propane dehydrogenation (PDH) to propene under industrially relevant conditions. A series of samples were synthesized by a precipitation method upon varying the ratio of OH−/Al3+ in the solution. This ratio was established to affect the ability of Al2O3 to form aluminium cations with lower coordination (Alcus) than regular surface Al3+ sites. Such defective sites show higher activity for propene formation and lower ability for coke formation. In addition to the preparation method, the kind of reducing agent for Al2O3 is decisive for creation of the desired defects, with CO showing higher reactivity owing to its ability to react with surface OH groups.

To date, a great number of various materials have been tested for the oxidative coupling of methane (OCM). On the basis of previous statistical analysis of OCM-related literature data, we developed novel catalysts based on K2MnO4 or KMnO4 supported on SiO2 showing selectivity to C2-hydrocarbons (C2H4 and C2H6) up to 68 or 66%. The analysis of catalysts containing the single components (Mn/SiO2, K2O/SiO2 or SiO2) demonstrates that the co-existence of K and Mn is essential for achieving high selectivity to the desired products. The selectivity can be additionally improved when the OCM reaction is performed in the presence of water. The positive effect of water is attributed to the suppressed direct oxidation of CH4 to CO2. Water also enhances the rates of methane conversion into C2-hydrocarbons and CO. Besides, the effects of water are more pronounced for samples based on crystalline SiO2 rather than amorphous SiO2. Transient experiments with isotopically labelled oxygen suggest that the accelerating effect should be of heterogenous nature. As the positive influence of water on the selective methane oxidation to C2-hydrocarbons has been established over different catalysts, it may be advantageous to consider it when developing novel materials for the OCM reaction and even for other oxidation reactions.