SwePub - search: WFRF:(Andersson Viktor 1983)

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1.	Andersson, Viktor, 1983, et al. (author) Integrated Algae Cultivation for Municipal Wastewater Treatment and Biofuels Production in Industrial Clusters 2012 In: World Renewable Energy Forum, WREF 2012. - 9781622760923 ; 1, s. 684-691 Conference paper (peer-reviewed)abstract This paper presents a case study on biofuels production from microalgae cultivated in municipal wastewater in Gothenburg, Sweden. A) Combined biodiesel and biogas production and B) only biogas production, are compared in terms of product outputs, impact on global CO2 emissions reduction and economic performance. Land-use efficiency of biofuels from microalgae was compared with other biofuel production routes. The biofuel production process is assumed to be integrated with a wastewater treatment plant and an industrial cluster, providing the opportunity to reduce the CO2 emissions of the process compared to stand-alone operation.The results show that case A is advantageous in terms of all the studied factors. A higher area efficiency of algae biofuels production routes compared to other biofuel production routes was shown. Nutrient availability in municipal wastewater is shown to be the limiting factor regarding product output. The competitive advantage of co-location with a wastewater treatment plant is clearly shown.
2.	Andersson, Viktor, 1983, et al. (author) Transition pathway towards a sustainable and competitive production of energy commodities and materials 2013 In: International Process Integration Jubilee Conference 2013. Conference paper (other academic/artistic)
3.	Broberg, Sarah, 1983-, et al. (author) Integrated Algae Cultivation for Biofuels Production in Industrial Clusters 2011 Reports (other academic/artistic)abstract Declining fossil resources and the issue of climate change caused by anthropogenic emissions of greenhouse gases make global action towards a more sustainable society inevitable. The EU decided in 2007 that 20 % of the union´s energy use should origin from renewable resources by the year 2020. One way of achieving this goal is to increase the utilisation of biofuels. Today 2nd generation biofuels are being developed. They are seen as a more sustainable solution than 1st generation biofuels since they have a higher area efficiency (more fuel produced per area) and the biomass can be cultivated at land which is not suitable for food crops. One of these 2nd generation biofuels are fuels derived from microalgae. In this study a thorough literature survey has been conducted in order to assess the State-of-the-Art in algae biofuels production. The literature review showed the importance of a supplementary function in conjunction with algae cultivation and therefore algae cultivation for municipal wastewater treatment and capturing CO2 emissions from industry was included in the study. It was assumed that all the wastewater of the city of Gothenburg, Sweden, was treated by algae cultivation. A computer model of the whole production process has been developed, covering; algae cultivation in conjunction with wastewater treatment, algae harvesting and biofuels production. Two different cases are modelled; a first case including combined biodiesel and biogas production, and a second case investigating only biogas production. Both cases have been evaluated in terms of product outputs, CO2 emissions savings and compared to each other in an economic sense. Utilising the nutrients in the wastewater of Gothenburg it is possible to cultivate 29 ktalgae/year. In the biogas case it is possible to produce 205 GWhbiogas/year. The biogas/biodiesel case showed a production potential of 63 GWhbiodiesel/year and 182 GWhbiogas/year. There is a deficit of carbon in the wastewater, hence CO2 is injected as flue gases from industrial sources. The biodiesel/biogas case showed an industrial CO2 sequestration capacity of 24 ktCO2/year while in the biogas case 22.6 ktCO2/year, could be captured. Estimating the total CO2 emissions savings showed 46 ktCO2/year in the biodiesel/biogas case and 38 ktCO2/year for the biogas case. The importance of including wastewater treatment in the process was confirmed, as it contributes with 13.7 ktCO2/year to the total CO2 emissions savings. Economic comparison of the two cases showed that biodiesel in conjunction with biogas production is advantageous compared to only biogas production. This is mainly due to the higher overall fuel yield and the high willingness to pay for biodiesel. The total incomes from biodiesel/biogas sales were calculated to 221 million SEK/year and 193 million SEK/year for biogas. It was found that the higher incomes from biodiesel/biogas sales repay the increased investment for the biodiesel process in approximately 3 years.
4.	Ali, Hassan, et al. (author) Cost estimation of heat recovery networks for utilization of industrial excess heat for carbon dioxide absorption 2018 In: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 74, s. 219-228 Journal article (peer-reviewed)abstract The absorption of CO 2 using solvents (e.g., amines) is considered a state-of-the-art, albeit energy-intensive process for CO 2 capture. While it is generally recognized that the utilization of waste heat has potential to reduce the energy-associated costs for CO 2 capture, the cost of waste heat recovery is seldom quantified. In this work, the cost of heat-collecting steam networks for waste heat recovery for solvent regeneration is estimated. Two types of networks are applied to waste heat recovery from the flue gases of four process industries (cement, silicon, iron & steel, and pulp & paper) via a heat recovery steam generator (HRSG). A novel approach is presented that estimates the capital and operational expenditures for waste heat recovery from process industries. The results show that the overall cost (CAPEX + OPEX) of steam generated from one hot flue gas source is in the range of 1.1–4.1 €/t steam. The cost is sensitive to economic parameters, installation factors, the overall heat transfer coefficient, steam pressure, and to the complexity of the steam network. The cost of steam from an existing natural gas boiler is roughly 5–20-times higher than that of steam generated from recovered waste heat. The CAPEX required to collect the heat is the predominant factor in the cost of steam generation from waste heat. The major contributor to the CAPEX is the heat recovery steam generator, although the length of the steam pipeline (when heat is collected from two sources or over long distances) is also important for the CAPEX.
5.	Andersson, Viktor, 1983, et al. (author) Algae-based biofuel production as part of an industrial cluster 2014 In: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 71, s. 113-124 Journal article (peer-reviewed)abstract This paper presents a study on the production of biofuels from algae cultivated in municipal wastewater in Gothenburg, Sweden. A possible biorefinery concept is studied based on two cases; Case A) combined biodiesel and biogas production, and Case B) only biogas production. The cases are compared in terms of product outputs and impact on global CO2 emissions mitigation. The area efficiency of the algae-based biofuels is also compared with other biofuel production routes. The study investigates the collaboration between an algae cultivation, biofuel production processes, a wastewater treatment plant and an industrial cluster for the purpose of utilizing material flows and industrial excess heat between the actors. This collaboration provides the opportunity to reduce the CO2 emissions from the process compared to a stand-alone operation. The results show that Case A is advantageous to Case B with respect to all studied factors. It is found that the algae-based biofuel production routes investigated in this study has higher area efficiency than other biofuel production routes. The amount of algae-based biofuel possible to produce corresponds to 31 MWfuel for Case A and 26 MWfuel in Case B.
6.	Andersson, Viktor, 1983, et al. (author) Alkali desorption from ilmenite oxygen carrier particles used in biomass combustion 2024 In: Fuel. - 0016-2361 .- 1873-7153. ; 359 Journal article (peer-reviewed)abstract Oxygen-carrying fluidized bed materials are increasingly used in novel technologies for carbon capture and storage, and to improve the efficiency of fuel conversion processes. Potassium- and sodium-containing compounds are released during biomass combustion and may have both negative and positive effects on conversion processes. Ilmenite is an important oxygen carrier material with the ability to capture alkali in the form of titanates. This is a desirable property since it may reduce detrimental alkali effects including fouling, corrosion, and fluidized bed agglomeration. This study investigates the interactions of alkali-containing compounds with ilmenite particles previously used in an industrial scale (115 MWth) oxygen carrier aided combustion system. The ilmenite samples were exposed to temperatures up to 1000 °C under inert and oxidizing conditions while the alkali release kinetics were characterized using online alkali monitoring. Alkali desorption occurs between 630 and 800 °C, which is attributed to loosely bound alkali at or near the surface of the particles. Extensive alkali release is observed above 900 °C and proceeds during extended time periods at 1000 °C. The release above 900 °C is more pronounced under oxidizing conditions and approximately 9.1 and 3.2 wt% of the alkali content is emitted from the ilmenite samples in high and low oxygen activity, respectively. Detailed material analyses using scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy were conducted before and after temperature treatment, which revealed that the concentrations of potassium, sodium and chlorine decrease at the outermost surface of the ilmenite particles during temperature treatment, and Cl is depleted to a deeper level in oxidizing conditions compared to inert. The implications for ilmenite-ash interactions, oxygen carrier aided combustion and chemical looping systems are discussed.
7.	Andersson, Viktor, 1983, et al. (author) Alkali interactions with a calcium manganite oxygen carrier used in chemical looping combustion 2022 In: Fuel Processing Technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 227 Journal article (peer-reviewed)abstract Chemical-Looping Combustion (CLC) of biofuels is a promising technology for cost-efficient CO2 separation and can lead to negative CO2 emissions when combined with carbon capture and storage. A potential challenge in developing CLC technology is the effects of alkali metal-containing compounds released during fuel conversion. This study investigates the interactions between alkali and an oxygen carrier (OC), CaMn0.775Ti0.125Mg0.1O3-δ, to better understand the fate of alkali in CLC. A laboratory-scale fluidized bed reactor is operated at 800–900 °C in oxidizing, reducing and inert atmospheres to mimic CLC conditions. Alkali is fed to the reactor as aerosol KCl particles, and alkali in the exhaust is measured online with a surface ionization detector. The alkali concentration changes with gas environment, temperature, and alkali loading, and the concentration profile has excellent reproducibility over repeated redox cycles. Alkali-OC interactions are dominated by alkali uptake under most conditions, except for a release during OC reduction. Uptake is significant during stable reducing conditions, and is limited under oxidizing conditions. The total uptake during a redox cycle is favored by a high alkali loading, while the influence of temperature is weak. The implications for the understanding of alkali behavior in CLC and further development are discussed.
8.	Andersson, Viktor, 1983, et al. (author) Alkali-wall interactions in a laboratory-scale reactor for chemical looping combustion studies 2021 In: Fuel Processing Technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 217 Journal article (peer-reviewed)abstract Alkali metal-containing compounds are readily released during thermal conversion of solid fuels, and may have both detrimental and beneficial effects on chemical looping combustion. Here, we characterize alkali interactions with the inner walls of a laboratory-scale reactor under oxidizing, reducing and inert conditions at temperatures up to 900 °C. KCl aerosol particles are continuously introduced to the stainless steel reactor and the alkali concentration is measured on-line with a surface ionization detector. Aerosol particles evaporate at temperatures above 500 °C and KCl molecules rapidly diffuse to the reactor wall. Up to 92% of the alkali reaching the wall below 700 °C remains adsorbed, while re-evaporation is important at higher temperatures, where up to 74% remains adsorbed. Transient changes in alkali concentration are observed during repeated redox cycles, which are associated with changes in chemical composition of the wall material. Metal oxides on the reactor wall are partially depleted under reducing conditions, which allow for the formation of a new potassium-rich phase that is stable in a reducing atmosphere, but not under inert conditions. The observed wall effects are concluded to be extensive and include major transient effects depending on gas composition, and the implications for laboratory studies and improved experimental methodology are discussed.
9.	Andersson, Viktor, 1983, et al. (author) Design and first application of a novel laboratory reactor for alkali studies in chemical looping applications 2023 In: Fuel Processing Technology. - 0378-3820. ; 252 Journal article (peer-reviewed)abstract Alkali compounds are readily released during biomass conversion and their complex interactions with reactor walls and sampling equipment makes detailed investigations challenging. This study evaluates a novel laboratory-scale fluidized bed reactor for chemical looping combustion (CLC) studies. The reactor design is based on detailed consideration of the behavior of alkali-containing molecules and aerosol particles and is guided by computational fluid dynamic simulations. The design allows for interactions between gaseous alkali and a fluidized bed, while minimizing alkali interactions with walls before and after the fluidized bed. The function of the laboratory reactor is demonstrated in experiments using online gas and alkali analysis. Alkali is continuously fed to the reactor as KOH or KCl aerosol with and without a fluidized bed of the oxygen carrier CaMn0.775Ti0.125Mg0.1O3-δ present in inert, reducing and oxidizing conditions at temperatures up to 900 °C. Alkali uptake by the OC is characterized in all conditions, and observed to sensitively depend on gas composition, reactor temperature and type of alkali compound. The experimental setup is concluded to have a significantly improved functionality compared to a previously used reactor, which opens up for detailed studies of interactions between alkali compounds and oxygen carriers used in CLC.
10.	Andersson, Viktor, 1983, et al. (author) Dubbel energivinst med alger som biobränsle 2013 In: Energimagasinet. Journal article (other academic/artistic)abstract Idag kan produktionen av biobränsle påverka livsmedelsförsörjningen negativt. Istället för att biobränsleproduktion ska konkurrera med produktion av livsmedel kan en hittills outnyttjad resurs - kommunalt avloppsvatten - användas för produktion av alger som i sin tur kan användas till biogas och biodiesel. Ny forskning visar på denna potential.
11.	Andersson, Viktor, 1983, et al. (author) Efficient Utilization of Industrial Excess Heat for Post-combustion CO2 Capture: An Oil Refinery Sector Case Study 2014 In: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 63, s. 6548-6556 Conference paper (peer-reviewed)abstract A key issue in post-combustion carbon capture is the choice of absorbent. In this paper two different absorbents, monoethanolamine (MEA) and ammonia (NH3), have been modeled in Aspen Plus at different temperatures for possible implementation at an oil refinery. The focus of investigation is the possibilities of heat integration between the oil refinery and the carbon capture process and how these possibilities could change in a future situation where energy efficiency measures have been implemented.The results show that if only using excess heat from the refinery for heating of the carbon capture process, the MEA process can capture more CO2 than the NH3 process. It is shown that the configuration requiring least supplementary heat when applying carbon capture to all flue gases is MEA at 120 °C.The temperature profile of the excess heat from the refinery suits the MEA and NH3 processes differently. The NH3 process would benefit from a flat section above 100 °C to better integrate the heat needed to reduce slip, while the MEA process only needs heat at stripper temperature.
12.	Andersson, Viktor, 1983 (author) Excess heat utilisation in oil refineries - CCS and algae-based biofuels 2016 Doctoral thesis (other academic/artistic)abstract The main objective of this thesis is to investigate two different concepts for CO2 mitigation, from a system perspective, in relation to the oil refining industry: CO2 capture and storage; and algae-based biofuels. For all these processes, process integration with an oil refinery is assumed. The oil refinery sector is a major emitter of CO2 and is responsible for 9% of the industrial emissions of CO2 worldwide. Oil refineries have large amounts of unused excess heat, which can be used to satisfy the heat demands of a CO2 capture plant, a land-based algal cultivation facility, or an algae-based biofuel process. The use of this excess heat significantly reduces the cost for CO2 capture, while an economic evaluation for algae-based biofuels has not been made.Since the amount of heat available from the oil refinery´s processes increase with decreasing temperature in the stripper reboiler, it was investigated how much heat was available at different temperatures. It was also investigated how the decreased temperature would affect the heat demand of CO2 capture processes that use MEA or ammonia as the absorbent. The findings show that it is possible to capture more CO2 using excess heat when the temperature in the stripper reboiler is decreased. For the MEA process, the lower limit of the temperature interval investigated showed the maximum CO2 capture rate, while the ammonia process benefitted from a lower temperature than the standard temperature but showed maximal CO2 capture rate above the lower limit. These results are valid only when using excess heat to satisfy the entire heat demand. At the case study refinery, the available excess heat could satisfy between 28% and 50% of the heat demand of the MEA process when treating the flue gases from all chimneys, depending on the temperature in the stripper reboiler. This utilisation of excess heat represents a way to reduce significantly the costs for CCS in an oil refinery. Land-based cultivation of algae proved to be unsuitable for the utilisation of excess heat. Since the cultivation pond is exposed to wind, rain, and cold, the heat demand fluctuates strongly over the year, making the pond an unstable recipient of the excess heat.Three types of biofuel processes based on microalgae and macroalgae were investigated with respect to integration with the oil refinery. For the algae-based biofuel processes, heat integration and material integration combined to increase the efficiency of the system. When two different build margin technologies (with different CO2 emission factors) are employed for electricity production, macroalgae-based biofuel production appears to be the more robust process from the perspective of CO2 due to the lower electricity demands of the algal cultivation and harvesting phases.
13.	Andersson, Viktor, 1983, et al. (author) Gaseous alkali interactions with ilmenite, manganese oxide and calcium manganite under chemical looping combustion conditions 2024 In: Fuel Processing Technology. - 0378-3820 .- 1873-7188. ; 254 Journal article (peer-reviewed)abstract Alkali species present in biomass pose significant challenges in chemical looping combustion (CLC) processes and other thermal conversion applications. The interactions between different alkali species and three common oxygen carrier (OC) materials that are considered to be state of the art in CLC applications have been investigated. A dedicated fluidized bed laboratory reactor was used to study interactions of KCl, NaCl, KOH, NaOH, K2SO4 and Na2SO4 with manganese oxide, calcium manganite and ilmenite. Alkali vapor was generated by injecting alkali salts under reducing, oxidizing and inert conditions at 900 °C. Gaseous species were measured online downstream of the reactor, and the efficiency of alkali uptake was determined under different conditions. The result show significant alkali uptake by all OCs under the studied conditions. Ilmenite shows near complete alkali uptake in reducing conditions, while manganese oxide and calcium manganite exhibited less effective alkali uptake, but have advantages in terms of fuel conversion and oxidizing efficiency. Alkali chlorides, sulfates and hydroxides show distinctly different behavior, with alkali hydroxides being efficiently captured all three investigate OC materials. The findings contribute to a deeper understanding of alkali behavior and offer valuable guidance for the design and optimization of CLC with biomass.
14.	Andersson, Viktor, 1983, et al. (author) Industrial excess heat driven post-combustion CCS: The effect of stripper temperature level 2014 In: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 21, s. 1-10 Journal article (peer-reviewed)abstract The implementation of post-combustion CCS provides an opportunity for the oil refining sector to drastically decrease its CO2 emissions. Previous studies have shown that the largest cost is the heat supply to the stripper reboiler. When performing CCS at an oil refinery it could therefore prove economically beneficial to utilize the excess heat from refinery processes to meet this demand for heat. The present study investigates the heat demand in a stripper reboiler at different temperature levels from 120 degrees C down to 90 degrees C. At temperatures lower than 120 degrees C the heat demand increases, but the availability of excess heat also increases. A case study that connects heat demand results with data from an oil refinery shows that if only excess heat is utilized as a heat source, the amount of CO2 that can be separated is largest when the temperature in the stripper reboiler is 90 degrees C. If, however, CCS with a capture rate of 85% were applied to the four largest chimneys at the refinery, the external heat demand would be the lowest for the standard temperature of 120 degrees C. (C) 2013 Elsevier Ltd. All rights reserved.
15.	Andersson, Viktor, 1983, et al. (author) Integration of algae-based biofuel production with an oil refinery: Energy and carbon footprint assessment 2020 In: International Journal of Energy Research. - : Hindawi Limited. - 1099-114X .- 0363-907X. ; 44:13, s. 10860-10877 Journal article (peer-reviewed)abstract Biofuel production from algae feedstock has become a topic of interest in the recent decades since algae biomass cultivation is feasible in aquaculture and does therefore not compete with use of arable land. In the present work, hydrothermal liquefaction of both microalgae and macroalgae is evaluated for biofuel production and compared with transesterifying lipids extracted from microalgae as a benchmark process. The focus of the evaluation is on both the energy and carbon footprint performance of the processes. In addition, integration of the processes with an oil refinery has been assessed with regard to heat and material integration. It is shown that there are several potential benefits of co-locating an algae-based biorefinery at an oil refinery site and that the use of macroalgae as feedstock is more beneficial than the use of microalgae from a system energy performance perspective. Macroalgae-based hydrothermal liquefaction achieves the highest system energy efficiency of 38.6%, but has the lowest yield of liquid fuel (22.5 MJ per 100 MJalgae) with a substantial amount of solid biochar produced (28.0 MJ per 100 MJalgae). Microalgae-based hydrothermal liquefaction achieves the highest liquid biofuel yield (54.1 MJ per 100 MJalgae), achieving a system efficiency of 30.6%. Macro-algae-based hydrothermal liquefaction achieves the highest CO2 reduction potential, leading to savings of 24.5 resp 92 kt CO2eq/year for the two future energy market scenarios considered, assuming a constant feedstock supply rate of 100 MW algae, generating 184.5, 177.1 and 229.6 GWhbiochar/year, respectively. Heat integration with the oil refinery is only possible to a limited extent for the hydrothermal liquefaction process routes, whereas the lipid extraction process can benefit to a larger extent from heat integration due to the lower temperature level of the process heat demand.
16.	Andersson, Viktor, 1983, et al. (author) Techno-economic analysis of excess heat driven post-combustion CCS at an oil refinery 2016 In: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 45, s. 130-138 Journal article (peer-reviewed)abstract Carbon capture and storage may, as a bridging technology, rapidly decrease CO2 emissions in the industrial sector. In this paper, a techno-economic study of a future MEA carbon capture plant implemented at a case study oil refinery is presented. Costs are calculated for six setups of carbon capture at the refinery. Excess heat from the refinery processes is used in the capture plant for regeneration of the absorption fluid, and the stripper reboiler temperature is varied to increase the extractable of excess heat. Supplementary heating is carried out with a heat pump. The number of chimneys to be included in the capture process is also varied, resulting in different CO2 concentrations and amounts of CO2 at the inlet of the capture plant. Results show that the specific cost for carbon capture increases as the amount of captured carbon increases due to the need for heat pumps. The costs are in the range of 41-57(sic)/t for the low-temperature cases (T-Reb =90 degrees C) and 39-44(sic)/t for the high-temperature cases (T-Reb = 120 degrees C).
17.	Andersson, Viktor, 1983, et al. (author) Temperature Dependence of Heat Integration Possibilities of an MEA Scrubber Plant at a Refinery 2013 In: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 37, s. 7205-7213 Conference paper (peer-reviewed)abstract A study has been conducted in order to investigate how the specific heat requirements in the stripper reboiler of a MEA capture plant changes with changing temperature. It was found that the increase in heat demand is dramatic when lowering the temperature, approximately 40% when the temperature changes from 120 to 90° C. Heat integration with a refinery was also studied, and showed that even if the heat demand was larger for the lower temperature the heat integration possibilities were also larger for the base case.
18.	Beukes, Eldré W., et al. (author) Development and technical functionality of an Internet-based intervention for tinnitus in the UK 2016 In: Internet Interventions. - : Elsevier. - 2214-7829. ; 6, s. 6-15 Journal article (peer-reviewed)abstract PurposeCreative approaches to improve access to evidence-based tinnitus treatments are required. The purpose of this study was to develop an Internet-based cognitive behavioural therapy (iCBT) intervention, for those experiencing tinnitus in the United Kingdom (UK). Furthermore, it aimed, through technical functionality testing, to identify specific aspects of the iCBT that require improving.MethodAn innovative iCBT intervention for treating tinnitus in the UK has been developed using a cognitive-behavioural theoretical framework. This iCBT was evaluated by two user groups during this developmental phase. Initially, five expert reviews evaluated the intervention, prior to evaluation by a group of 29 adults experiencing significant levels of tinnitus distress. Both groups evaluated iCBT in an independent measures design, using a specifically designed satisfaction outcome measure.ResultsOverall, similar ratings were given by the expert reviewers and adults with tinnitus, showing a high level of satisfaction regarding the content, suitability, presentation, usability and exercises provided in the intervention. The iCBT intervention has been refined following technical functionality testing.ConclusionsRigorous testing of the developed iCBT intervention has been undertaken. These evaluations provide confidence that further clinical trials can commence in the UK, to assess the feasibility and effectiveness of this iCBT intervention for tinnitus.
19.	Dods, Robert, 1989, et al. (author) Ultrafast structural changes within a photosynthetic reaction centre. 2021 In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 589:7841, s. 310-314 Journal article (peer-reviewed)abstract Photosynthetic reaction centres harvest the energy content of sunlight by transporting electrons across an energy-transducing biological membrane. Here we use time-resolved serial femtosecond crystallography1 using an X-ray free-electron laser2 to observe light-induced structural changes in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds. Structural perturbations first occur at the special pair of chlorophyll molecules of the photosynthetic reaction centre that are photo-oxidized by light. Electron transfer to the menaquinone acceptor on the opposite side of the membrane induces a movement of this cofactor together with lower amplitude protein rearrangements. These observations reveal how proteins use conformational dynamics to stabilize the charge-separation steps of electron-transfer reactions.
20.	Sköld Gustafsson, Viktor (author) Decision Support for Emergency Response to Multiple Natural Hazards : CHALLENGES AND NEEDS 2022 Licentiate thesis (other academic/artistic)abstract Global warming exceeding 1.5°C above pre-industrial levels will very likely lead to unavoidable increases of several climate hazards in the coming decades. Climate change phenomena can increase the risk of several extreme weather events, leading to risks of what is commonly considered as natural hazards, for instance landslides and forest fires. These chains or networks of events are termed natural multi-hazards or compound natural events, referring to a primary event or a driver that directly triggers or increases the probability of one or more secondary events by changing the environment. The very likely increase of single and compound natural hazards due to climate change require increased attention since it may imply new challenges to emergency response systems and new threats to society. Especially, how emergency response systems can prepare for and respond to these hazards by using knowledge of the interactions between different natural events. The purpose of this thesis is to increase the knowledge on interactions between natural hazards, investigate how multiple natural hazards lead to challenges for emergency response systems, and how these challenges can be addressed. The purpose can be further divided into three objectives: (i) to identify relevant multiple natural hazards in a Swedish context, (ii) to identify planning and decision-making challenges these hazards may imply for emergency response systems, and (iii) to develop a decision support tool addressing one of these challenges. The objectives have been addressed in three sub-studies, one for each of the objectives, leading to the production of four papers. The first sub-study focused on the first objective and resulted in the construction of a national natural hazard interaction framework for Sweden, which is presented in Paper 1. The second sub-study focused on the second objective, leading to the identification of needs for information, planning, and decision support systems in the Swedish emergency response system. The results from this study are presented in Paper 2 and 3. The third and last sub-study focused on the development of a decision support tool addressing one of the needs identified in the second sub-study. The sub-study led to the development of an optimization model for resource preparedness location planning, presented in Paper 4. This thesis contributes to the emergency management field, both scientifically and practically. The scientific contributions are the development of a national natural hazard interactions framework and a resource preparedness location model for wildfires, both filling gaps in the current knowledge. Also, the thesis contributes scientifically through the alternative applications of theory, which can inform the research community in future studies. The natural hazard interaction framework and the resource preparedness location model for wildfires are also considered practical contributions. The former can support the extension of regional and local risk and vulnerability analyses to also include multiple natural hazards, while the latter sheds light on the potential of optimization-based decision support tools to increase preparedness to natural hazards.
21.	Sköld Gustafsson, Viktor, et al. (author) Identifying decision support needs for emergency response to multiple natural hazards: an activity theory approach 2023 In: Natural Hazards. - : Springer. - 0921-030X .- 1573-0840. Journal article (peer-reviewed)abstract Planning and decision making in emergency response systems face new challenges due to climate changes and the increased risk of multiple or compound natural hazards. This is especially the case in areas with inexperience of such events. The aim of this paper is to identify important activities concerning planning and decision-making during responses to natural hazards, and their potential need for decision support. The knowledge base of the study consists of interviews with 12 representatives from the Swedish emergency response system, supplemented by documents covering policies, operations, and responsibility. Thematic coding was applied to the interview data for identification of important planning and decision activities. Needs of decision support were identified by applying activity theory to the identified activities. We found needs of decision support connected to eight identified key activities concerning consequence analysis, national reinforcements, and resource management. The results illuminate a lack of technology to support response activities during both single and multiple natural hazards. The findings can inform policy makers of emergency response of where to concentrate the development of tools for collaborative preparedness and response work to cope with future challenges from natural hazards.
22.	Sköld Gustafsson, Viktor, et al. (author) Managing Natural Hazards in Sweden – Needs for Improved Information and Decision Support Systems 2022 In: ISCRAM 2022 Conference Proceedings – 19th International Conference on Information Systems for Crisis Response and Management. - 9788284270999 ; , s. 376-384 Conference paper (peer-reviewed)abstract This paper explores opportunities for information systems to support emergency response to multiple natural hazards. Interviews were conducted with 12 representatives from actors of the Swedish emergency response system about response to multiple natural hazards. Challenges and needs connected to five themes influencing the response effort were identified: Cooperation, Resource management, Command and control, Common operational picture, and Risk management. The results illuminate a lack of technology to support decisions and analyses during emergency response to both single and multiple natural hazards. Based on this, the paper suggests and discusses information systems and decision support tools to assist in satisfying the identified needs. The findings can inform policy makers in emergency response of where to concentrate the development of collaborative preparedness and response work, and the scientific community of future research directions.
23.	Sköld Gustafsson, Viktor, et al. (author) Multipla naturhändelser i Sverige 2021 Reports (other academic/artistic)abstract Denna rapport syftar till att (i) redogöra för begreppet ’multipla naturhändelser’ och kunskapsläget kring interaktioner mellan olika naturhändelser, samt att (ii) fastställa vilka naturhändelser som är mest relevanta med hänsyn till beredskap och förmåga innanför Sveriges territoriala gränser. Översiktligt diskuteras dessutom förutsättningar för och behov av hantering av multipla naturhändelser. Rapporten innehåller en sammanställning av hur naturhändelser interagerar med varandra i vetenskaplig litteratur, en sammanställning av förekomst av naturhändelser i Sverige utifrån sekundärdata från myndigheter och en workshop med experter för att identifiera multipla naturhändelser med relevans för svenska förhållanden. Rapporten presenterar resultat från en första delstudie inom forskningsprojektet Effektiv hantering av multipla naturhändelser (EMMUNE), som finansieras av Myndigheten för samhällsskydd och beredskap (MSB) och Formas. Naturhändelser kan vara multipla på olika sätt. En primär naturhändelse kan direkt utlösa en eller flera andra naturhändelser. De sekundära händelserna kan sedan i sin tur orsaka ytterligare händelser, vilket skapar en kaskad av händelser. En naturhändelse kan också öka sannolikheten eller förutsättningen för en eller flera andra naturhändelser, exempelvis genom höga flöden eller långvarig torka. Det kan också inträffa flera naturhändelser som sammanfaller i tid och rum utan att händelserna är direkt relaterade till varandra. I rapporten redogörs för interaktioner mellan följande naturhändelser: jordbävning; tsunami; geofysiska jordrörelser och hydrologiska skred, ras och sättningar; vulkanutbrott; blixtnedslag; extremt höga respektive låga temperaturer; isstormar; översvämningar; torka; laviner; skogs- och markbränder; skadedjursangrepp; meteoriter; och geomagnetisk storm. En bedömning görs också av vilka naturhändelser som kan anses vara mest relevanta för Sverige i relation till vårt klimat och väder. Bedömningen grundar sig i litteraturstudien och det genomgångna materialet kring förekomst och magnitud och leder fram till att följande naturhändelser anses relevanta: laviner; kraftig vind; kraftig nederbörd; extrema temperaturer; blixturladdningar; översvämningar; ras och sättningar; torka; samt skog- och markbränder. De påverkas alla antingen direkt eller indirekt av klimategenskaper eller väderhändelser. Kunskapen om klimatförändringarnas påverkan på förekomsten av extrema väderförhållanden är varierande och innefattar olika grader av osäkerheter beroende av vilken typ av extremt förhållande det handlar om. I Sverige innefattar eller drivs multipla naturhändelser oftast av atmosfäriska eller hydrologiska händelser. De multipla naturhändelser som av experterna anses vara mest frekventa samt får allvarliga konsekvenser inkluderar antingen höga flöden eller skogsbrand i kombination med annan händelse. När det gäller kunskapsläget kring multipla naturhändelser visar litteraturstudien att det finns vetenskapligt stöd för en mängd olika interaktioner mellan naturhändelser. Experterna som deltog i vår workshop beskriver också att vissa naturhändelser, som exempelvis kustöversvämningar, oftast uppstår vid ”multipla” väderfenomen och att det finns många potentiella multipla interaktioner både kopplade till ett utgångsläge med långvarig torka och värme eller höga flöden i vattendrag. Sammantaget talar detta för att naturhändelser behöver betraktas mer utifrån ett multipelt perspektiv. Naturhändelser sker inte bara isolerat utan kan påverkas av eller påverka andra naturhändelsers förlopp, antingen genom ett direkt utlösande eller genom förändring av miljön som ökar sannolikheten för andra naturhändelser. I såväl forskning om naturhändelser och klimatförändringar som i forskning om hantering av naturhändelser har händelserna hittills främst betraktats en och en. Det genomgångna materialet indikerar inte att Sverige kommer att drabbas av några nya företeelser på nationell nivå, däremot är det troligt att frekvensen och magnituden för vissa av naturhändelserna kommer att öka i ett förändrat klimat. Det kan även finnas anledning att inkludera biologiska naturhändelser, såsom det gjordes i exempelvis MSB:s sammanställning av riskområden och scenarioanalyser (MSB 2015). För att öka medvetenheten om multipla naturhändelser beskrivs tre scenarier för multipla naturhändelser, 1. en situation med höga flöden i vattendrag där det oväntat inträffar ett kraftigt regn, 2. en situation med en torr sommar där det inträffar en värmebölja, och 3. en relativ nederbördsfattning senvinter och varm april med låg markfuktigheten där det uppstår en skogsbrand. Ett lågtryck drar sedan in som ger mycket kraftiga vindar varvid skogsbranden intensifieras och sprids. Redan när det gäller förekomst och omfattning av enskilda atmosfäriska eller hydrologiska händelser är det stora osäkerheter i befintliga prognoser och klimatförändringsprojektioner, även om det sannolikt kommer bli både starkare och mer frekvent förekomst av väderfenomen framgent. Att prognostisera och simulera multipla naturhändelser innefattar därmed ännu större osäkerheter. Beredskapen att hantera multipla naturhändelser kan gynnas av ett fortsatt fokus på konsekvensbaserade vädervarningssystem. Exempelvis att vid en period med höga flöden i vattendrag kunna informera att om detta fortsätter ökar risken för sekundära händelser exempelvis skred. Multipla naturhändelsers hantering skulle kunna underlättas genom att tillhandahålla information baserad på förutsättningar för olika naturhändelser på specifika platser, detta för att bedöma risken för sekundära naturhändelser under givna förutsättningar samt de möjliga konsekvenserna av multipla naturhändelser för en specifik plats. Det är därför viktigt att för de tänkta målgrupperna öka förmågan att kunna tolka sådan information och vädervarningar samt att målgrupperna i förväg haft möjlighet kartlägga tänkbara konsekvenser för olika naturhändelser så att behovet av insatser snabbare kan bedömas när en händelse inträffar.

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