| 1. |
- Buhr, Katarina, et al.
(författare)
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End users’ challenges, needs and requirements for assessing resilience
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report summarizes the results from the work in Task 1.3 of the SmartResilience project. Within the Work Package “Establishing the project baseline and the common framework”, Task 1.3 contributes to a better understanding of the indicators for resilience assessment by examining the actual needs from the ones responsible for such an assessment.This deliverable establishes, at an early stage in the project, a baseline for understanding end users’ current and projected challenges, needs and requirements for assessing resilience of critical infrastructures and using resilience indicators (RIs) for doing so. This is a necessary step to ensure that the resilience assessment methodology and smart RIs will be designed in ways that are useful and therefore adopted, thus delivering increased resilience for critical infrastructures, beyond the project.The identification of end users’ challenges, needs and requirements in assessing resilience within Task 1.3 has been guided by an actor analysis approach and is predominantly based on qualitative methods, consisting of semi-structured individual or group interviews with key end users connected to critical infrastructures, desktop studies and literature reviews. The task has covered eight critical infrastructures in the SmartResilience case studies (ALPHA-HOTEL) as well as an additional case study covering interconnected critical infrastructures (DSB). Furthermore, in order to take into account end users beyond these nine case studies, a literature review has been carried out as well as a survey among the Members of the Community of Users of Safe, Secure and Resilient Societies (CoU).The key findings from Task 1.3 are summarized below:Designing useful indicators requires extensive end user involvement in order to be able to integrate the indicators into existing organizational processes. There is a need to define the “work” that the indicators are supposed to do and make sure they meet the challenges of interconnected infrastructures.End users in the case studies confirmed and provided further insight into the following key challenges, which are illustrated by examples: the concept of resilience; external threats (climate change, cyber-attacks, terrorist attacks, flooding); the complexity of critical infrastructures; and data management.End users in the case studies expressed specific needs and requirements, which has been analyzed in terms of five dimensions of resilience and illustrated by examples: system/physical; information/data; organizational/business: societal/political and cognitive/decision-making.The survey to the CoU indicated that some actors do not see a need to develop RIs because they think current practices are sufficient. Although the low response rate calls for caution in interpreting the results, the responses suggests a number of challenges for the SmartResilience project. First, the need for the project to create assessments and RIs that are clearly regarded as providing added value in relation to end users’ current and projected needs. Second, the challenge to design assessments and RIs that can be widely disseminated, while at the same time taking different contexts into account.Three implications for indicator development are suggested. Firstly, indicators should be developed with an appropriate end user in mind. This means posing questions such as: What organization, and what function or user group, will use it? What is their interest in using indicators? What is their legitimacy to spread the indicator in the critical infrastructure? Secondly, indicators should be developed in dialogue with end users, in order to increase the likelihood that they cover areas that are relevant and currently not sufficiently covered; are relevant, understandable and legitimate; and are designed according to end users’ own motives for assessing resilience and perceptions of usefulness. Thirdly, indicators should be developed in alignment with end users’ organizational processes. This suggests that the project should develop indicators which are easy to understand in order to decrease the dependency of individual expertise and misunderstandings across different organizations; meet the level of capacity of resources that the organization(s) are willing to spend on assessments of resilience; and allow end users to collect, process and share (big) data, taking data security into account.
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| 2. |
- Gebremariam, Goitom K., et al.
(författare)
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Hydrogen Evolution Volcano(es)-From Acidic to Neutral and Alkaline Solutions
- 2022
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Ingår i: Catalysts. - : MDPI AG. - 2073-4344. ; 12:12
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Tidskriftsartikel (refereegranskat)abstract
- As the global energy crisis continues, efficient hydrogen production is one of the hottest topics these days. In this sense, establishing catalytic trends for hydrogen production is essential for choosing proper H-2 generation technology and catalytic material. Volcano plots for hydrogen evolution in acidic media are well-known, while a volcano plot in alkaline media was constructed ten years ago using theoretically calculated hydrogen binding energies. Here, for the first time, we show that the volcano-type relationships are largely maintained in a wide range of pH values, from acidic to neutral and alkaline solutions. We do this using theoretically calculated hydrogen binding energies on clean metallic surfaces and experimentally measured hydrogen evolution overpotentials. When metallic surfaces are exposed to high anodic potentials, hydrogen evolution can be boosted or significantly impeded, depending on the type of metal and the electrolyte in which the reaction occurs. Such effects are discussed here and can be used to properly tailor catalytic materials for hydrogen production via different water electrolysis technologies.
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| 3. |
- Jovanovic, Aleksandar, et al.
(författare)
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Tuning the electronic and chemisorption properties of hexagonal MgO nanotubes by doping - Theoretical study
- 2018
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 457, s. 1158-1166
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Tidskriftsartikel (refereegranskat)abstract
- Oxide materials offer a wide range of interesting physical and chemical properties. Even more versatile behavior of oxides is seen at the nanoscale, qualifying these materials for a number of applications. In this study we used DFT calculations to investigate the physical and chemical properties of small hexagonal MgO nanotubes of different length. We analyzed the effect of Li, B, C, N, and F doping on the properties of the nanotubes. We find that all dopants favor the edge positions when incorporated into the nanotubes. Doping results in the net magnetization whose value depends on the type of the impurity. Using the CO molecule as a probe, we studied the adsorption properties of pristine and doped MgO nanotubes. Our results show that the dopant sites are also the centers of significantly altered chemical reactivity. While pristine MgO nanotubes adsorb CO weakly, very strong adsorption at the dopant sites (B-, C-, and N-doped nanotubes) or neighboring edge atoms (F- and Li-doped nanotubes) is observed. Our results suggest that impurity engineering in oxide materials can be a promising strategy for the development of novel materials with possible use as selective adsorbents or catalysts.
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| 4. |
- Jovanovic, Aleksandar Z., et al.
(författare)
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Enhancement of hydrogen evolution reaction kinetics in alkaline media by fast galvanic displacement of nickel with rhodium-From smooth surfaces to electrodeposited nickel foams
- 2022
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 414
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Tidskriftsartikel (refereegranskat)abstract
- Energy-efficient hydrogen production is one of the key factors for advancing hydrogen-based economy. Alkaline water electrolysis is the main route for the production of high-purity hydrogen, but further improvements of hydrogen evolution reaction (HER) catalysts are still needed. Industrial alkaline electrolysis relies on Ni-based catalysts, and here we describe a drastic improvement of HER activity of Ni in alkaline media using several model catalysts for HER, obtained upon nickel surface modification in the aqueous solution of rhodium salts, where a spontaneous deposition of rhodium takes place, based on the chemical displacement reaction 3Ni + 2Rh3+ = 3Ni2+ + 2Rh. In the case of smooth Ni-poly electrodes, HER activity surpasses the activity of Pt-poly after just 30 s of exchange with Rh. SEM analysis showed that Rh is uniformly distributed, and that surface roughness changes are lower than 10%, which is in agreement with the electrochemical measurements. Furthermore, XPS analysis has shown effective incorporation of Rh in the surface, while DFT calculations suggest that hydrogen binding is significantly weakened on the Rh-modified Ni surfaces. Such tuning of the hydrogen binding energy is seen as the main factor governing HER activity improvements. The same galvanic displacement protocols were employed for nickel foam electrodes and electrodeposited Ni on Ti mesh. In both cases, somewhat longer Rh exchange times are needed to obtain superior activities than for the smooth Ni surface, but within 10 min. HER overpotentials corresponding to -10 mA cm-2 for nickel foam and electrodeposited Ni electrodes, after modification with Rh, amounted to only -0.07 and -0.09 V, respectively. Thus, it is suggested that a fast spontaneous displacement of Ni with Rh could effectively boost HER in alkaline media with minor cost penalties with regards to energy saving in the electrolysis process.
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| 5. |
- Jovanović, Aleksandar Z., et al.
(författare)
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Reactivity of Stone-Wales defect in graphene lattice – DFT study
- 2023
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Ingår i: FlatChem. - : Elsevier. - 2452-2627. ; 42
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the reactivity of carbon surfaces is crucial for the development of advanced functional materials. The SW defect is commonly present in carbon materials, but a comprehensive understanding of its effects on the reactivity of carbons is missing. In this study, we systematically investigate the reactivity of graphene surfaces with the Stone-Wales (SW) defect using Density Functional Theory calculations. We explore the atomic adsorption of various elements, including rows 1–3 of the Periodic Table, potassium, calcium, and selected transition metals. Our results demonstrate that the SW defect enhances binding with the studied adsorbates when compared to pristine graphene, with carbon and silicon showing the most significant differences. Additionally, we examine the effects of mechanical deformation on the lattice by constraining the system with the SW defect to the pristine graphene cell. Interestingly, these constraints lead to even stronger binding interactions. Furthermore, for carbon, nitrogen, and oxygen adsorbates, we observe that mechanical deformation triggers the incorporation of adatoms into the carbon bond network, leading to the reorganization of the SW defect structure. This work establishes a foundation for future studies in the defect and strain engineering of graphene, opening avenues for developing advanced materials and catalysts with enhanced reactivity and performance.
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| 6. |
- Nedić Vasiljević, Bojana, et al.
(författare)
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Galvanic displacement of Co with Rh boosts hydrogen and oxygen evolution reactions in alkaline media
- 2023
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Ingår i: Journal of Solid State Electrochemistry. - : Springer Nature. - 1432-8488 .- 1433-0768. ; 27:7, s. 1877-1887
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Tidskriftsartikel (refereegranskat)abstract
- The growing energy crisis put an emphasis on the development of novel efficient energy conversion and storage systems. Here we show that surface modification of cobalt by a fast galvanic displacement with rhodium significantly affects the activity towards hydrogen (HER) and oxygen evolution reactions (OER) in alkaline media. After only 20 s of galvanic displacement, the HER overpotential is reduced by 0.16 V and OER overpotential by 0.06 V. This means that the predicted water splitting voltage is reduced from 2.03 V (clean Co anode and cathode) to 1.81 V at 10 mA cm−2 (Rh-exchanged Co electrode). During the galvanic displacement process, the surface roughness of the Co electrode does not suffer significant changes, which suggests an increase in the intrinsic catalytic activity. Density Functional Theory calculations show that the reactivity of the Rh-modified Co(0001) surface is modified compared to that of the clean Co(0001). In the case of HER, experimentally observed activity improvements are directly correlated to the weakening of the hydrogen-surface bond, confirming the beneficial role of Rh incorporation into the Co surface. Graphical abstract: [Figure not available: see fulltext.].
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| 7. |
- Neumüller, Daniela, et al.
(författare)
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Hydrogen Evolution Reaction on Ultra-Smooth Sputtered Nanocrystalline Ni Thin Films in Alkaline Media-From Intrinsic Activity to the Effects of Surface Oxidation
- 2023
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Ingår i: Nanomaterials. - : MDPI. - 2079-4991. ; 13:14
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Tidskriftsartikel (refereegranskat)abstract
- Highly effective yet affordable non-noble metal catalysts are a key component for advances in hydrogen generation via electrolysis. The synthesis of catalytic heterostructures containing established Ni in combination with surface NiO, Ni(OH)(2), and NiOOH domains gives rise to a synergistic effect between the surface components and is highly beneficial for water splitting and the hydrogen evolution reaction (HER). Herein, the intrinsic catalytic activity of pure Ni and the effect of partial electrochemical oxidation of ultra-smooth magnetron sputter-deposited Ni surfaces are analyzed by combining electrochemical measurements with transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy. The experimental investigations are supplemented by Density Functional Theory and Kinetic Monte Carlo simulations. Kinetic parameters for the HER are evaluated while surface roughening is carefully monitored during different Ni film treatment and operation stages. Surface oxidation results in the dominant formation of Ni(OH)(2), practically negligible surface roughening, and 3-5 times increased HER exchange current densities. Higher levels of surface roughening are observed during prolonged cycling to deep negative potentials, while surface oxidation slows down the HER activity losses compared to as-deposited films. Thus, surface oxidation increases the intrinsic HER activity of nickel and is also a viable strategy to improve catalyst durability.
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| 8. |
- Pasti, Igor A., et al.
(författare)
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Atomic adsorption on graphene with a single vacancy : systematic DFT study through the periodic table of elements
- 2018
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 20:2, s. 858-865
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Tidskriftsartikel (refereegranskat)abstract
- Vacancies in graphene present sites of altered chemical reactivity and open possibilities to tune graphene properties by defect engineering. The understanding of chemical reactivity of such defects is essential for successful implementation of carbon materials in advanced technologies. We report the results of a systematic DFT study of atomic adsorption on graphene with a single vacancy for the elements of rows 1-6 of the periodic table of elements (PTE), excluding lanthanides. The calculations have been performed using the PBE, long-range dispersion interaction-corrected PBE (PBE+D2 and PBE+D3) and non-local vdW-DF2 functionals. We find that most elements strongly bind to the vacancy, except for the elements of groups 11 and 12, and noble gases, for which the contribution of dispersion interaction to bonding is most significant. The strength of the interaction with the vacancy correlates with the cohesive energy of the elements in their stable phases: the higher the cohesive energy is, the stronger bonding to the vacancy can be expected. As most atoms can be trapped at the SV site we have calculated the potentials of dissolution and found that in most cases the metals adsorbed at the vacancy are more "noble" than they are in their corresponding stable phases.
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| 9. |
- Pasti, Igor A., et al.
(författare)
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Atomic adsorption on pristine graphene along the Periodic Table of Elements - From PBE to non-local functionals
- 2018
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Ingår i: Applied Surface Science. - : ELSEVIER SCIENCE BV. - 0169-4332 .- 1873-5584. ; 436, s. 433-440
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Tidskriftsartikel (refereegranskat)abstract
- The understanding of atomic adsorption on graphene is of high importance for many advanced technologies. Here we present a complete database of the atomic adsorption energies for the elements of the Periodic Table up to the atomic number 86 (excluding lanthanides) on pristine graphene. The energies have been calculated using the projector augmented wave (PAW) method with PBE, long-range dispersion interaction corrected PBE (PBE+D2, PBE+D3) as well as non-local vdW-DF2 approach. The inclusion of dispersion interactions leads to an exothermic adsorption for all the investigated elements. Dispersion interactions are found to be of particular importance for the adsorption of low atomic weight earth alkaline metals, coinage and s-metals (11th and 12th groups), high atomic weight p-elements and noble gases. We discuss the observed adsorption trends along the groups and rows of the Periodic Table as well some computational aspects of modelling atomic adsorption on graphene.
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| 10. |
- Rafailovic, Lidija D., et al.
(författare)
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High density of genuine growth twins in electrodeposited aluminum
- 2019
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Ingår i: Science Advances. - : AMER ASSOC ADVANCEMENT SCIENCE. - 2375-2548. ; 5:10
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate electrodeposition as a synthesis method for fabrication of Al coatings, up to 10 mu m thick, containing a high density of genuine growth twins. This has not been expected since the twin boundary energy of pure Al is very high. TEM methods were used to analyze deposited Al and its nanoscaled twins. DFT methods confirmed that the influence of the substrate is limited to the layers close to the interface. Our findings are different from those achieved by sputtering of Al coatings restricted to a thickness less than 100 nm with twins dominated by epitaxial effects. We propose that in the case of electrodeposition, a high density of twins arises because of fast nucleation and is additionally promoted by a monolayer of adsorbed hydrogen originating from water impurities. Therefore, electrodeposition is a viable approach for tailoring the structure and properties of thicker, deposited Al coatings reinforced by twins.
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| 11. |
- Vollmer, Maike, et al.
(författare)
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Initial Framework for Resilience Assessment
- 2016
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Rapport (refereegranskat)abstract
- This report is targeting a framingof what SmartResilience actually wants to measure –“resilience”–,taking relevant research results and existing guidelinesand standardsinto account. This is especially challenging due to the vast variety of understandings, definitions, concepts, and applications of the term, including usages in different research areas or fields of application. In addition, for thereasonof this variety, a huge number of articlesand reportsdiscussing the term, its understandings and usages on a theoretical basis have been developed. Even several comprehensive reviews on the term, including qualitative and quantitative literature analyses as well as expert interviews, have already been conducted.SmartResilience starts with an initial concept of (critical infrastructure) resilience, which was already defined in the proposal phase of the project. Up-to-date comprehensive reviews on definitions and concepts of resilience, including critical infrastructure resilience, have been available from recent results prepared in the framework of projects that answer to the call topic EU H2020 DRS-07-2014 “Crises and disaster resilience –operationalizing resilience concepts”. The resulting reportshave been reviewed, identifying results that seem useful for the SmartResilience resilience definition and concept. Reviewing approaches and identifying aspects that seem useful for SmartResilience from selected additionalsources (international and US organisations, industry, standards) complemented the basis for framing the (still initial) SmartResilience resilience definition and concept.The initial definition has only slightly been changed, resulting in:Resilience of an infrastructure is the ability to understand risks, anticipate, prepare for, and adapt to changing conditions and withstand, respond to, and recover rapidly from disruption.However, the concept of resilience in a broader sense (including further framing questions such as resilience “of what” is in focus, what is the relation to vulnerability or risk management, how should the different levels and components of resilience be categorised) has been complemented, and slightly changed. Several aspects that were concluded based onthe reviews, are described in this report as issues to be considered and decided on when workingon the actual methodology (WP3), and/ or its application to specific SCI’s(WP2, WP5).This includes questions such asif a “transformative” character should be included as a main componentof resilience, or if “ability” and“capacity” should be distinguished, but also what to consider when identifyingrelevantissues for the resilience of specific SCI’s.Asfurther instrument forcreating and maintaining a common understanding, a first version of a glossary of terms that are relevant for SmartResilience has been developed, is online accessible,and will be continuously updated throughout the project.
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