• Energy Research
• 2021-2025close
• other engineering and technologies close
• DE close
• EU close

This study focuses on formulating the most sustainable concrete by incorporating recycled concrete aggregates and other products retrieved from construction and demolition (C&D) activities. Both recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) are firstly used to fully replace the natural coarse and fine aggregates in the concrete mix design. Later, the cement rich ultrafine particles, recycled glass powder and mineral fibres recovered from construction and demolition wastes (CDW) are further incorporated at a smaller rate either as cement substituent or as supplementary additives. Remarkable properties are noticed when the RCA (4–12 mm) and RFA (0.25–4 mm) are fully used to replace the natural aggregates in a new concrete mix. The addition of recycled cement rich ultrafines (RCU), Recycled glass ultrafines (RGU) and recycled mineral fibres (RMF) into recycled concrete improves the modulus of elasticity. The final concrete, which comprises more than 75% (wt.) of recycled components/materials, is believed to be the most sustainable and green concrete mix. Mechanical properties and durability of this concrete have been studied and found to be within acceptable limits, indicating the potential of recycled aggregates and other CDW components in shaping sustainable and circular construction practices. The authors wish to acknowledge the financial support from EU Horizon 2020 Project VEEP ‘‘Cost-Effective Recycling of C&DW in High Added Value Energy Efficient Prefabricated Concrete Compo-nents for Massive Retrofitting of our Built Environment” (No.723582).

Effective access control techniques are in demand, as electronically assisted healthcare services require the patient’s sensitive health records. In emergency situations, where the patient’s well-being is jeopardized, different healthcare actors associated with emergency cases should be granted permission to access Electronic Health Records (EHRs) of patients. The research objective of our study is to develop machine learning techniques based on patients’ time sequential health metrics and integrate them with an Attribute Based Access Control (ABAC) mechanism. We propose an ABAC mechanism that can yield access to sensitive EHRs systems by applying prognostic context handlers where contextual information, is used to identify emergency conditions and permit access to medical records. Specifically, we use patients’ recent health history to predict the health metrics for the next two hours by leveraging Long Short Term Memory (LSTM) Neural Networks (NNs). These predicted health metrics values are evaluated by our personalized fuzzy context handlers, to predict the criticality of patients’ status. The developed access control method provides secure access for emergency clinicians to sensitive information and simultaneously safeguards the patient’s well-being. Integrating this predictive mechanism with personalized context handlers proved to be a robust tool to enhance the performance of the access control mechanism to modern EHRs System.

Abstract In wear protection, cobalt-base or nickel-base materials are very often used for coatings in order to increase the functionality and service life of components. These materials such as stellite, the nickel-base alloy Colmonoy 56 or Tribaloy T400 are characterized by a high resistance to abrasion, adhesion as well as excellent corrosion resistance even at higher temperatures. Given the criticality of cobalt and partly also nickel, it is necessary to look for more sustainable alternatives to be used in wear protection. One possibility is to further develop iron-base materials so that they can be used in wear protection to prevent both abrasion and adhesion. In this context, sufficient corrosion resistance is desirable. This paper will elaborate on the development of a novel intermetallic iron-base hard alloy.

To mitigate climate change, individual greenhouse gas emissions need to decline substantially. This paper empirically explores the relationship between individual carbon footprints and carbon literacy as well as socio-economic and attitudinal factors. To operationalize carbon literacy, we distinguish between carbon knowledge and carbon engagement. Our econometric analysis uses widely representative survey data for 1000 individuals in Germany and distinguishes between components of an aggregate carbon footprint and of carbon footprints related with electricity consumption, heating, motorized individual transport, aviation, and dietary choices. We find a negative and sizeable correlation between carbon engagement and the aggregate footprint, as well as the footprints related to electricity consumption and diet. For example, a one-unit increase in our index reflecting carbon engagement corresponds to a decrease in the aggregate carbon footprint of about 4%. Furthermore, for carbon knowledge we find a negative correlation with the carbon footprint from diet. We also find significant correlations between the carbon footprints and gender, age, income, education, environmental preferences, and policy orientation, which generally exhibit the intuitively expected signs, but differ somewhat across activities. Overall, our findings support the notion that fostering carbon engagement represents a more effective strategy for reducing individuals' carbon footprints than enhancing carbon knowledge.

Abstract Proton exchange membrane fuel cells (PEMFCs) are seen as of one of many possible future means of driving the change towards a zero-emission society. In a civil aircraft, fuel cell systems can have multiple potential benefits, such as reduced noise, lowered emissions and higher fuel economy. For controlling the fuel cell temperature, thermal management systems are required which can be optimized for aircraft applications regarding their weight and reliability. In this work, a novel, simplified and light-weight thermal management system relying on hydrogen cooling is presented and analysed. To investigate the feasibility, a test rig and a three-dimensional, singular channel model in ANSYS Fluent® were designed. Fuel cell temperature could be maintained within the set threshold in the model and the test rig, thus showing that controlling the fuel cell temperature via hydrogen is a viable alternative thermal management system. Results from the model indicate that both the hydrogen mass flow and hydrogen inlet temperature should be used to control the fuel cell temperature. Furthermore, operating the fuel cell at medium to low current densities is favourable for hydrogen cooling. Future studies will explore the advantages of alternate flow field designs to facilitate thermal management system relying on hydrogen.

This paper contains the results of research on a large assemblage of jumping spiders collected by J.-C. Ledoux from Ivory Coast in 1974–75. In total, 105 species are included. Three new genera are erected Pulcherula gen. nov., Sphericula gen. nov. and Vicirionessa gen. nov. Two generic names are synonymized, Polemus Simon, 1902 with Baryphas Simon, 1902 and Brancus Simon, 1902 with Thyene Simon, 1885. Twenty eight new species are described: Afraflacilla albopunctata sp. nov. (♀), Ansienulina lamottei sp. nov. (♂), Asemonaea pusilla sp. nov. (♀), Detalik cavally sp. nov. (♀), Evarcha zougoussi sp. nov. (♀), Heliophanus (Heliophanus) minimus sp. nov. (♂♀), Hyllus ignotus sp. nov. (♀), Hyllus solus sp. nov. (♀), Hyllus unicolor sp. nov. (♀), Icius bandama sp. nov. (♂♀), Langona recta sp. nov. (♂), Malizna zabkai sp. nov. (♀), Menemerus niangbo sp. nov. (♀), Myrmarachne galea sp. nov. (♀), Phintella brevis sp. nov. (♂), Phintella globosa sp. nov. (♀), Phintella occidentalis sp. nov. (♂), Phintella transversa sp. nov. (♂), Pochytoides mirabilis sp. nov. (♂♀), Pochytoides tonkoui sp. nov. (♀), Pochytoides tournieri sp. nov. (♂), Pulcherula magna gen. et sp. nov. (♂), Rhene ferkensis sp. nov. (♀), Sonoita ledouxi sp. nov. (♂♀), Sphericula globulifera gen. et sp. nov. (♀), Thiratoscirtus silvestris sp. nov. (♂♀), Tusitala bandama sp. nov. (♀) and Tusitala cornuta sp. nov. (♂). Five specific names are synonymized: Polemus chrysochirus Simon, 1902 with Baryphas jullieni Simon, 1902, Viciria mondoni Berland & Millot, 1941with Malloneta guineensis Simon, 1902, Brancus lacrimosus Wesołowska & Edwards 2008 with Vicirionessa fuscimana (Simon, 1903), Viciria monodi Berland & Millot, 1941 and Viciria equestris pallida Berland & Millot, 1941 with Vicirionessa equestris (Simon, 1903). Hyllus natali peckhamorum Berland & Millot, 1941 is removed from synonymy of Hyllus brevitarsis Simon, 1902, revalidated and its rank is raised as Hyllus peckhamorum Berland & Millot, 1941 stat. nov. Also rank of Telamonia aequipes minor Lessert, 1925 is elevated as Phintella minor (Lessert, 1925) stat. nov. Menemerus dubius Berland & Millot, 1941 is removed from nomina dubia. This species is considered valid and is redescribed. A lectotype is designated for it. The male of Mexcala torquata Wesołowska, 2009 and females of Hyllus tuberculatus Wanless & Clark, 1975, Iranattus principalis (Wesołowska, 2000), Myrmarachne eidmanni Roewer, 1942 and Thiratoscirtus tentativus (Szűts & Jocqué, 2001) are described for the first time. Many new combinations are proposed. Twenty ex Brancus are recombined: Hyllus nigeriensis (Wesołowska & Edwards, 2012) comb. nov., Thyene blaisei (Simon, 1902) comb. nov., Thyene calebi (Kanesharatnam & Benjamin, 2018) comb. nov., Thyene mutica (Simon, 1902) comb. nov., Thyene verdieri (Berland & Millot, 1941) comb. nov., Vicirionessa besanconi (Berland & Millot, 1941) gen. et comb. nov., Vicirionessa fuscimana (Simon, 1903) gen. et comb. nov., Vicirionessa mustela (Simon, 1902) gen. et comb. nov., Vicirionessa niveimana (Simon, 1902) gen. et comb. nov., Vicirionessa occidentalis (Wesołowska & Russell-Smith, 2011) gen. et comb. nov., Vicirionessa peckhamorum (Lessert, 1927) gen. et comb. nov., Vicirionessa signata (Dawidowicz & Wesołowska, 2016) gen. et comb. nov. Four ex Viciria are recombined: Vicirionessa chabanaudi (Fage, 1923) gen. et comb. nov., Vicirionessa equestris (Simon, 1903) gen. et comb. nov., Vicirionessa prenanti (Berland & Millot, 1941) gen. et comb. nov., Vicirionessa tergina (Simon, 1903) gen. et comb. nov. and one species ex Hyllus: Vicirionessa albocincta (Thorell, 1899) gen. et comb. nov. Furthermore, the following two new combinations are proposed: Thiratoscirtus tentativus (Szűts & Jocqué, 2001) comb. nov. (ex Bacelarella) and Baryphas galeatus (Simon, 1902) comb. nov. (ex Polemus). For 11 species known so far from single records new data are presented: Heliophanus butemboensis Wesołowska, 1986, Hyllus lwoffi Berland & Millot, 1941, Hyllus tuberculatus Wanless & Clark, 1975, Menemerus dubius Berland & Millot, 1941, Mexcala torquata Wesołowska, 2009, Neaetha maxima Wesołowska & Russell-Smith, 2011, Pachyballus miniscutulus Wesołowska, Azarkina & Wiśniewski 2020, Phintella paludosa Wesołowska & Edwards, 2012, Thiratoscirtus gambari Wesołowska & Russell-Smith, 2011, Tusitala guineensis Berland & Millot, 1941 and Tusitala lutzi Lessert, 1927.

This paper aims to fill a research gap in the area of consumer-citizen attitudes to business models for decentralized energy storage, at the level of households and buildings. The study focuses on the interaction of such attitudes and their underlying motivation factors with socio-cultural, contextual factors. Self-determination theory (SDT) is used as a theoretical framework, to connect interpersonal and contextual factors, addressing the question of how contexts influence the motivation to support energy storage. Drawing on SDT, this study examines the role of autarky (independence from the energy system), autonomy (control over energy management) and relatedness (degree of sharing required) in this regard, embedded and interpreted in the socio-cultural local context of two demonstration sites in Sweden and Portugal. A mixed method approach is used. Quantitative survey data provides information on local social and cultural dimensions, followed by stakeholder consultation workshops that elicit participants’ views on different models of decentralized energy storage. The findings raise questions of how to improve autarky and autonomy for prosumers, while keeping the need for time investment low and provide flexibility regarding the required degree of interaction between prosumers. Implications for business models and policy support for citizen-centered sustainable urban energy systems are derived.