| 1. |
- Allard, Erik, 1976-, et al.
(författare)
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Quantitative aspects of analyzing small molecules - monitoring singly or doubly charged ions? : A case study of ximelagatran.
- 2010
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Ingår i: Rapid Communications in Mass Spectrometry. - : Wiley. - 0951-4198 .- 1097-0231. ; 24:4, s. 429-435
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Tidskriftsartikel (refereegranskat)abstract
- Precision, reproducibility and lower limit of quantitation (LLOQ) are important characteristics of a quantitative method. We have investigated these properties for Ximelagatran (Xi), which has a high tendency to form doubly charged ions in electrospray ionization (ESI), by studying the percentage of doubly charged species formed when varying the formic acid (FA) concentration, analyte concentration, amount of organic modifier and flow rate. It was found that the percentage of [Xi + 2H]2+ can be controlled to be more than 90% or less than 10% by varying the amount of FA present, and that the change between these values is dramatic. Furthermore, the percentage of [Xi + 2H]2+ formed decreases with increased analyte concentration and increased flow rate. No apparent relationship with the amount of organic modifier was found. The results have the implication that, by carefully controlling the selected parameters, the LLOQ, precision and reproducibility can be improved. We have compared the fragmentation of the singly and doubly charged species and concluded that the [Xi + 2H]2+ ion is more inclined to undergo fragmentation than [Xi + H]+. As a consequence, unusual instrumental settings had to be used for the experiments. The fragmentation patterns are to a great extent similar, but the doubly charged species is more inclined to generate low-mass product ions.
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| 2. |
- Alsarve [Arvidsson], Daniel, 1976-
(författare)
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I ständig strävan efter framgång? : föreningsdemokratins innehåll och villkor i Örebro Sportklubb 1908-89
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this dissertation is to study the conditions of and changes in sociative democracy processes at club level. One sports club is studied, Örebro Sportklubb (ÖSK), from its foundation in 1908 up to 1989. The main sources are club minutes, member magazines and annual reports. Democracy, and its twofolded relation to sport and economy processes, is the main problem area of the study. The specific question is how aspirations for economic effectiveness and sporting success influenced the democracy processes in ÖSK between 1908 and 1989.The Swedish sports movement has been described as a democratic movement. But the same movement has also been portrayed as an undemocratic movement made of men, for men. The study is based on a broad understanding of the democracy concept where issues of representativeness, influence, participation and knowledge are prominent. At a club level, the study is analysing the contents of the Swedish sports movement's democracy and its change during the 1900s. The thesis also illustrates how the pursuit of economic efficiency affected the associative democracy. These efficiencies were visible already in the 1920s, but was deepened during the 1970s. In short, the democratic range decreased, and successful sections became less and less motivated to finance the deficits of other sections.But the increased market orientation did not only represent a threat to the associative democracy. Marketisation and commercialization also preconditioned the democracy. At the club arena (Eyravallen), the members met in the clubhouse and café which, in turn, deepened the social capital and friendships within the club.
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| 3. |
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| 4. |
- Amirkhani, Ardeshir, et al.
(författare)
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Interferon-beta affects the tryptophan metabolism in multiple sclerosis patients
- 2005
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Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 12:8, s. 625-631
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Tidskriftsartikel (refereegranskat)abstract
- Tryptophan and its metabolites are of great interest in understanding the pathogenesis of multiple sclerosis (MS). The total levels of tryptophan and its metabolites, kynurenine and kynurenic acid were determined in plasma by capillary liquid chromatography electrospray ionisation tandem mass spectrometry. This is the first report of the plasma levels of these analytes in healthy controls and relapsing-remitting MS patients receiving long-term and acute interferon-beta (IFN-beta) treatment. Twenty-four hours post-administration increased kynurenine levels (first IFN MS versus healthy, P = 0.042) and kynurenine/tryptophan ratio (K/T; first IFN MS versus healthy, P =0.027; first IFN MS versus long-term IFN MS, P = 0.036) were found. The long-term IFN MS group had higher K/T ratios at 4 and 12 h post-administration (P = 0.015 and 0.009, respectively). The increase of K/T ratio in the first IFN MS group indicate an induction of the enzyme indolamine-2,3-dioxygenase (IDO), as reported earlier in experimental allergic encephalomyelitis. As IDO is participating in both inflammatory and neurodegenerative processes, further knowledge of its involvement in the pathogenesis of MS is of great importance.
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| 5. |
- Andersson, Sara, et al.
(författare)
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Rehabilitering
- 2007
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Ingår i: Nordisk lärobok i audiologi. - Bromma : C. A. Tegnér AB. - 9789163194405 ; , s. 325-389
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Sjukdomstillstånd och skador i organ och vävnader orsakar diverse funktionella avvikelser, som i sin tur ger upphov till symptom, som personen ifråga kan iaktta och lida av. Dessa orsakar funktionsnedsättningar, som påverkar individens möjligheter att fungera och klara sig i sin dagliga miljö hemma, i olika arbetssituationer och i olika sociala sammanhang.
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| 6. |
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| 7. |
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Aquatic Conservation with Focus on Margaritifera margaritifera : Proceedings of the International Conference in Sundsvall, Sweden, 12-14 August, 2009
- 2012
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Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- The freshwater pearl mussel Margaritifera margaritifera (L.) has attracted a large human interest, since the mussel is fascinating from biological, cultural andenvironmental perspectives. The mussel has a complicated life cycle dependingon host fish, and has great demands on its habitat. Furthermore, the mussel is anenvironmental indicator, and is used as an umbrella and flagship species. Pearl fishing has been described in Sweden as early as in the 16th century and by Carl Linnaeus in the 18th century.Many freshwater pearl mussel populations have insufficient recruitment and therefore decrease in numbers, and many populations are even extinct. Therefore, conservation work on the freshwater pearl mussel is going on all over Europe. Actions to preserve the freshwater pearl mussel will also favour other aquatic species – freshwater pearl mussel conservation is aquatic biodiversity conservation! WWF (World Wide Fund for Nature) Sweden implemented the project “The Freshwater Pearl Mussel and its habitats in Sweden” during 2004-2009 (LIFE04NAT/SE/000231). The overall objective was to improve the habitats of juvenile freshwater pearl mussels and the host fish brown trout Salmo trutta in21 streams. The actions were improvements of the biotopes, re-introduction of mussels, information to the stakeholders, and development of planning methods. An international conference “Aquatic Conservation with Focus on the Freshwater Pearl Mussel Margaritifera margaritifera” was held in Sundsvall 12–14 August, 2009. In these proceedings, presentations from the conference are published.
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| 8. |
- Ardelius, John, et al.
(författare)
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On the effects of caching in access aggregation networks
- 2012
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Ingår i: ICN 2012, Helsinki, Finland. - : Association for Computing Machinery (ACM). - 9781450314794
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Konferensbidrag (refereegranskat)abstract
- All forecasts of Internet trac point at a substantial growth over the next few years. From a network operator perspective, efficient in-network caching of data is and will be a key component in trying to cope with and profit from this increasing demand. One problem, however, is to evaluate the performance of different caching policies as the number of available data items as well as the distribution networks grows very large.In this work, we develop an analytical model of an aggregation access network receiving a continuous flow of requests from external clients. We provide exact analytical solutions for cache hit rates, data availability and more. This enables us to provide guidelines and rules of thumb for operators and Information-Centric Network designers.Finally, we apply our analytical results to a real VoD trace from a network operator and show that substantial bandwidth savings can be expected when using in-network caching in a realistic setting.
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| 9. |
- Ardelius, John, et al.
(författare)
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On the effects of caching in access aggregation networks
- 2012. - 6
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Konferensbidrag (refereegranskat)abstract
- All forecasts of Internet traffic point at a substantial growth over the next few years. From a network operator perspective, efficient in-network caching of data is and will be a key component in trying to cope with and profit from this increasing demand. One problem, however, is to evaluate the performance of different caching policies as the number of available data items as well as the distribution networks grows very large. In this work, we develop an analytical model of an aggregation access network receiving a continuous flow of requests from external clients. We provide exact analytical solutions for cache hit rates, data availability and more. This enables us to provide guidelines and rules of thumb for operators and Information-Centric Network designers. Finally, we apply our analytical results to a real VoD trace from a network operator and show that substantial bandwidth savings can be expected when using in-network caching in a realistic setting.
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| 10. |
- Arvidsson, Anna K, 1971-, et al.
(författare)
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Friktions- och texturutveckling på nya beläggningar
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En ny vägyta bör vara och upplevas som säker av trafikanterna oavsett vilket väglag som råder. Det är därför viktigt att vägbanan har en tillfredställande nivå på friktion redan när vägen öppnas. Det finns begränsade dokumenterade kunskaper hur vägen förändras den första tiden efter en beläggningsåtgärd.Syftet med detta projekt är att fastställa hur friktionen förändras under den första tiden efter att vägbeläggningen är lagd och trafikpåsläpp sker. Ambitionen är att kunna avgöra om nylagda vägavsnitt har nedsatt friktion och ge rekommendationer för när en friktionsmätning ska utföras och hur skyltning ska ske i anslutning till beläggningsarbeten. Upplägget har varit att följa olika objekt med täta friktions- och texturmätningar från strax innan trafikpåsläpp tills nivåerna har stabiliserats.Initialt är friktionen hög för att sen avta med mängden trafik. Efter 1–3 veckor nåddes det lägsta värdet och därefter ökade eller stabiliserades friktionen. Gemensamt för alla undersökta sträckor var att det sker stora förändringar i texturnivåerna från att det första fordonet trafikerar vägen och därefter är den starkaste tendensen en sjunkande texturnivå tills en stabil nivå uppnås efter 1–3 veckor.
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| 11. |
- Arvidsson, Björn, et al.
(författare)
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A methodological approach for mapping and analysing cascading effects of flooding events
- 2023
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Ingår i: International Journal of River Basin Management. - : Informa UK Limited. - 1814-2060 .- 1571-5124. ; 21:4, s. 659-671
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Tidskriftsartikel (refereegranskat)abstract
- Current local or regional flood risk assessments, as required by the EU flood risk directive, rarely account for cascading effects due to interdependencies between critical infrastructures. However, it is essential to consider these effects, as they may severely impact areas outside the immediate flood risk area. The main purpose is to present and problematize a method (AB-CEM) for mapping and analysing cascading effects due to floods, aiming at also being relevant for other spatially widespread hazards. The method development and the pilot study, in Sweden, reveal that there is a prominent practical need for methods for mapping and analysing critical infrastructure interdependencies and cascading effects. Another key finding is that the method process and its results can serve as an important basis for decision-making about proactive and reactive efforts related to geographically extensive hazards. We further conclude that there is a recurring problem regarding sensitive and secret data. More specifically, the conflicting interests of information availability and information security concerning critical infrastructures, which needs to be resolved at the national level and communicated through clear guidelines. The method is a much-needed step towards accounting for cascading effects of floods in practice.
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| 12. |
- Arvidsson, Björn
(författare)
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Cascading effects and critical infrastructure : Methods, challenges, and implications
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cascading effects, arising from intricate interactions among vital social and technical infrastructures, are essential to consider when assessing the societal impacts of various disruptions caused by, for example, natural hazards, climate change, and antagonistic attacks. Critical Infrastructures (CIs) form the backbone of society, and their interdependent nature amplifies the risk of cascading effects. To analyse and mitigate large-scale disruptions in CIs, numerous countries and organisations, including Sweden and the European Union, have implemented several resilience management programs and policies.This thesis aims to enhance understanding and methodologies for analysing cascading effects across interdependent CIs, particularly within the context of the Swedish implementation of EU directives. Employing various methods such as scoping studies, qualitative content analysis, and vulnerability analysis, the research reveals both scientific and practical gaps in the consideration of cascading effects. The findings reveal an immature consideration of cascading effects in assessments in Sweden related to flood risk management and that CIs are frequently treated in isolation, hindering the identification of interdependencies and analysis of cascading effects. Challenges include a lack offeasible analysis methods, data accessibility issues, national security and confidentiality considerations and resource constraints.To address these challenges, the thesis proposes a simplified yet robust method (AB-CEM) aiding risk analysts and crisis managers in identifying interdependencies and cascading effects. It also advocates for a coordinated national initiative to gather CI data and establish secure data-sharing platformsalongside explicit guidelines for handling sensitive data and an empirical library of cascading effects accounts.The thesis explores and emphasises the importance of considering cascading effects in risk, vulnerability and resilience assessments to ensure comprehensive identification and mitigation of potential risks and vulnerabilities. Ignoring these effects could lead to significant consequences being overlooked, particularly in severe scenarios. Thus, integrating cascading effects into assessments, incentives and governance structures is crucial for effective governance and resilience-building efforts.
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| 13. |
- Arvidsson, Björn, et al.
(författare)
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Case studies of risk governance – a literature review
- 2016
-
Ingår i: Risk, Reliability and Safety - Proceedings of the 26th European Safety and Reliability Conference : Innovating Theory and Practice - Innovating Theory and Practice. - Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742 : CRC Press. - 9781138029972 - 9781315374987 ; , s. 1231-1238
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Konferensbidrag (refereegranskat)
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| 14. |
- Arvidsson, Björn, et al.
(författare)
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Critical infrastructure, geographical information science and risk governance: A systematic cross-field review
- 2021
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Ingår i: Reliability Engineering & System Safety. - : Elsevier BV. - 0951-8320. ; 213, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Two key challenges for governing and managing critical infrastructure risk and resilience are interdependencies between infrastructures and the multi-actor setting in which they operate. This paper looks beyond the Critical Infrastructure (CI) field of research to identify and discuss cross-disciplinary approaches to address these challenges. It explores two related and slightly overlapping research fields: Geographical Information Science (GIScience) and Risk Governance (RG). The purpose is to systematically explore how concepts and approaches from these two fields can help develop the CI field further. The overall methodology follows the scoping study framework, which is strengthened by presenting a novel method for article keyword analysis of 14 170 articles guiding a content analysis of 51 articles. The results reveal that research areas intersecting CI and GIScience are natural hazard modelling, network analysis, data management, and geovisualisation and for CI and RG the inclusion of socio-cultural dimensions. These areas constitute good opportunities for further research. Challenges for cross-disciplinary research and practical applications include harmonisation of concepts, management of confidential data, and addressing less-technical CI sectors. In conclusion, the CI field is young and growing, and in need of further cross- and interdisciplinary research endeavours to tackle the complex issues at hand.
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| 15. |
- Arvidsson, Björn, et al.
(författare)
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CRITICAL INFRASTRUCTURES, GISCIENCE AND RISK GOVERNANCE: A LITERATURE REVIEW OF SYNERGISTIC RESEARCH OPPORTUNITIES
- 2018
-
Ingår i: ; , s. 19-20
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Konferensbidrag (refereegranskat)abstract
- Critical infrastructures today are highly interdependent and increasingly important in providing services to the rest of the society. At the same time, each type of infrastructure requires specialised knowledge to design and manage. Therefore, to get a better understanding of how the infrastructures and the effect of interdependencies work as a whole, it is necessary to have an interdisciplinary approach to Critical Infrastructure Protection (CIP). We have identified two research fields with high potential for synergies with the CIP field, namely Geographical Information Science (GIScience) and Risk Governance (RG). GIScience is a mature research field which encompasses, for example, spatial data collection, spatial statistics, theories of spatial data and data structures. RG is a relatively young field which focuses on how several stakeholders can manage shared risks, for example, the effect of interdependencies, together. Other researchers have also expressed a potential for synergies in combining these areas. This study reviews scientific literature that integrates either GIScience or RG in a CIP context, or preferably all three fields simultaneously. The review was carried out based on a scoping study methodology. Preliminary results from the study show that GIScience is used to perform a variety of tasks within a CIP-context such as data collection, information management, both supporting and performing modelling and simulation, hazard mapping, vulnerability mapping or visualisation of data. Most GIScience-related articles are closer related to risk management or disaster risk reduction, and only a few combine it also slightly with an RG perspective. An interesting finding is that quite a few articles consider national geographical information databases as critical infrastructures by themselves. Another observation is that GIS is often used in combination with network theory, either to perform analysis directly in GIS software or as a pre- or post-processor for network analysis. The RG and CIP articles seem to focus on the need for a shift from risk management to risk governance within CIP. However, they remain limited to a conceptual level. We found several useful examples of combining GIScience or RG with CIP in the gathered material, although we did not find any articles that integrated all three fields as we see it. We conclude that there seem to be significant benefits and research opportunities in more closely and coherently integrating GIScience and RG approaches and methods to address research problems within the CIP-field.
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| 16. |
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| 17. |
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| 18. |
- Arvidsson, Björn, 1952-, et al.
(författare)
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Flodpärlmussla - vad behöver vi göra för att rädda arten? : En workshop på Karlstads universitet
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Flodpärlmusslans situation i Sverige är bekymmersam, och i en stor del av de återstående populationerna sker ingen nyrekrytering av små musslor. För att belysa kunskapsläget om flodpärlmusslans situation och för att diskutera olika åtgärdsmöjligheter genomfördes i november 2005 en work shop vid Karlstads universitet med deltagande av naturvårdare från olika myndigheter och forskare. Vid mötet presenterades aktuell forskning i Skandinavien och olika uppföljningar som sker i olika myndigheters regi. Mötet bekostades av länsstyrelsen i Västernorrland, som fått ett nationellt ansvar att ta fram ett åtgärdsprogram för arten. I denna sammanställning redovisas en del av de föredrag och diskussioner som förekom vid mötet.
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| 19. |
- Arvidsson, Björn, et al.
(författare)
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Flood risk assessments—Exploring maturity and challenges in Sweden
-
Ingår i: Journal of Flood Risk Management. - 1753-318X.
-
Tidskriftsartikel (refereegranskat)abstract
- Floods are destructive to society. Hence, to assess and manage flood risk is imperative. Flood risk assessments require several layers of analysis, from flood hazard to societal impact. This paper explores the maturity level and challenges related to three components of a comprehensive risk assessment: flood hazard, direct consequences, and indirect consequences. This is achieved by introducing and applying a maturity framework on flood hazard reports and flood risk management plans in Sweden, as required by the EU Floods Directive (FD). A longitudinal analysis is conducted over two FD cycles (2009–2015 and 2016–2021). Complementary interviews with county administrative boards and responsible authorities provide deeper insights into processes and practical challenges. The results reveal that the maturity level of flood hazard assessment is high, while direct and, in particular, indirect consequences assessments need increased attention and substantial improvements. Further, there is no significant increase in maturity between the FD cycles, indicating fundamental challenges towards achieving this. Critical steps forward include developing applicable methods for analysing both direct and indirect consequences of floods, improving data availability on functionality and interdependency of critical infrastructure and society at large, and creating incentives for a broader range of societal actors to participate in flood risk management.
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| 20. |
- Arvidsson, Björn, 1952-, et al.
(författare)
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Förändringar och kontinuitet i vardagslivets Värmland
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här studien ingår i Karlstads universitets och fakultetens för samhälls- och livsvetenskaper satsning på mångvetenskaplig forskning om "uthålliga livsmiljöer och komplexa nätverk". Målet med fakultetens satsning är att stimulera forskning och samverkan mellan offentliga och privata aktörer så att Karlstads universitet effektivt kan bidra till och bli en motor i det långsiktigt hållbara utvecklingsarbetet i regionen. Studien tar sin utgångspunkt i intervjuer med några värmländska familjer om hur vardagen gestaltar sig idag, hur det såg ut historiskt och hur det kan tänkas se ut i framtiden. Intervjuerna kommenteras av forskare från olika ämnesområden. I mötet mellan forskare från olika ämnen och forskningstraditioner uppstår nya sätt att problematisera det komplicerade växelspelet mellan olika sektorer av vår tillvaro. Problemen kan omformuleras, nya möten och kontakter vänder invanda tankegångar mot nya och innovativa riktningar och beredskapen att möta framtida utmaningar såväl för forskare som för regionala aktörer stärks och uppgraderas. Förhoppningen är att studien ska fungera som en plattform för den viktiga diskussionen kring uthållig regional utveckling för kvinnor, män, barn och gamla och stimulera innovationer och forskning som garanterar en framtid där utveckling och tillväxt balanseras mot uthållig miljö för människor och natur.
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| 21. |
- Arvidsson, Björn, et al.
(författare)
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High throughput analysis of tryptophan metabolites in a complex matrix using capillary electrophoresis coupled to time-of-flight mass spectrometry
- 2007
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1159:1-2, s. 154-158
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Tidskriftsartikel (refereegranskat)abstract
- A capillary electrophoresis method for separation and detection with time-of-flight mass spectrometry is described for tryptophan metabolites in the kynurenic pathway. Tryptophan metabolites are usually difficult to detect with electrospray mass spectrometry since they have low surface activity and occur in low nanomolar to micromolar range in body fluids. Modification of the silica-wall with 1-(4-iodobutyl)4-aza-1-azoniabicyclo[2,2,2]octane iodide, also named M7C4I, has successfully been used to deactivate the fused silica wall and generate a stable reversed electroosmotic flow. Utilizing this advantage together with electrospray ionization time-of-flight mass spectrometry, which generates high resolution and fast acquisition monitoring of species, proved to be successful even for such a complex matrix like human cerebrospinal fluid.
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| 22. |
- Arvidsson, Björn, et al.
(författare)
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Investigation method for cascading effects between critical infrastructures
- 2015
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Ingår i: Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015. - 9781138028791 ; , s. 3399-3407
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Konferensbidrag (refereegranskat)abstract
- This paper presents an investigation method for studying cascading effects in incidents, which is to some extent lacking in the scientific literature. Several incident investigation methods are reviewed and used to influence the presented method. The usefulness of the method is demonstrated in a case study for a recent event in Sweden, a severe flooding event in the city of Malmö in south of Sweden 31st of August 2014. The case study revealed that the method enables the gathering and structuring of information about cascading effects and conditions that affect the outcome of cascading effects. An advantage of the method is that it also captures aggravating or mitigating conditions as well as potential cascading effects, enabling the study of near misses and alternative scenario developments. Concluding that the method has proven its practical value and it fills a current gap when it comes to investigation methods focused on cascading effects.
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| 23. |
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| 24. |
- Arvidsson, Björn L, 1952-, et al.
(författare)
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Recruitment of the threatened mussel Margaritifera margaritifera in relation to mussel population size, mussel density and host density
- 2012
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Ingår i: Aquatic conservation. - Malden, MA : John Wiley & Sons. - 1052-7613 .- 1099-0755. ; 22, s. 526-532
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic, abiotic factors are considered main causes of recruitment failure of unionid mussels, including the freshwater pearl mussel (Margaritifera margaritifera). In this large-scale investigation, we instead examined the relationship between biotic factors and mussel recruitment.Juvenile mussel density was positively related to both mussel population size and density of which the last appeared to be a more accurate measure of recruitment.Host fish density of young-of-the-year and older brown trout (Salmo trutta) were positively related to recruitment. Moreover, the mean density of both age classes of fish, when grouped into density classes was positively related to juvenile mussel density, an effect that decreased at trout densities above 10 trout 100 m-2.There was a higher relative importance of mussel population size and density than trout density to recruitment.To increase recruitment of juvenile mussels, managers may apply measures that increase mussel density, and trout density up to about 10 trout 100 m-2 in connection to mussel beds. Mussel beds may also be managed and one possible measure within small and sparse mussel populations may be to concentrate the remaining mussels to areas where trout density is high. Likewise, young-of-the-year trout may also be moved to areas of high mussel density, as young trout individuals are relatively resident during their first year. This may increase mussel larval infection rates and mussel recruitment.
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| 25. |
- Arvidsson, Björn, et al.
(författare)
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Method for cascading effect analysis in flooding events
- 2018
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Ingår i: Proceedings of the 5th IAHR EUROPE CONGRESS : New Challenges in Hydraulic Research and Engineering - New Challenges in Hydraulic Research and Engineering. - 9789811127311 ; , s. 387-388
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A method is presented aiming at enabling more holistic flood risk management efforts by accounting for cascading effects that arise in critical infrastructure and vital societal functions in flooding events. The method is under development but shows promise in guiding national, regional and local risk management efforts in Sweden towards flooding events.
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| 26. |
- Arvidsson, Björn, et al.
(författare)
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Online capillary solid phase extraction and liquid chromatographic separation with quantitative tandem mass spectrometric detection (SPE-LC-MS/MS) of ximelagatran and its metabolites in a complex matrix.
- 2009
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Ingår i: Journal of chromatography. B. - : Elsevier BV. - 1570-0232 .- 1873-376X. ; 877:3, s. 291-297
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Tidskriftsartikel (refereegranskat)abstract
- This work presents the development and validation of a fully automated quantitative analysis method of melagatran, its prodrug ximelagatran, and its major metabolites for the study of drug behavior in biofluids. The method involves online sample clean-up and enrichment on a C4 capillary column followed by separation on a capillary C18 column. Electrospray ionization tandem mass spectrometric detection in positive ion mode was performed with multiple reactions monitoring of eight different transients, divided into two time segments with four transients each. The structural similarity, the complexity of the matrix (pig liver extract) and the formation of isobaric fragment ions, made efficient chromatographic separation necessary. The analysis method provides valid accuracy (<9%; RSD%), precision (<8%; RSD%), linearity (<1.2 nM–1 μM; R2 > 0.999), limit of quantitation (<3.6 nM), retention repeatability (<1.2%; RSD%), selectivity, as well as analyte and column stabilities over a wide concentration range.
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| 27. |
- Arvidsson, Björn, 1974-
(författare)
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Quantitative Bioanalysis : Liquid separations coupled to targeted mass spectrometric measurements of bioactive compounds
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Performing quantitative analysis of targeted bioactive compounds in biological samples, such as blood plasma, cerebrospinal fluid or extracts from pig liver, put high demands on the ruggedness of the method acquiring the results. In addition to the complexity of the sample matrix, the bioactive compounds targeted for analysis usually have low levels of natural abundance, further increasing the demand on the analytical method sensitivity. Furthermore, quantitation of analytes at trace levels in the presence of large amounts of interfering species in biofluids must aim for repeatable precision, high accuracy ensuring the closeness to the true values, a linear response spanning over several orders of magnitude and low limits of quantitation to be valid for monitoring disease states in clinical analysis.An analytical method most commonly follow a certain order of events, called the analytical chain, which includes; experimental planning, sampling, sample pre-treatment, separation of species, detection, evaluation, interpretation and validation, all equally important for the outcome of the results.In this thesis, the scope has been to create novel methods, or to refine already existing methods, in order to achieve even better performances of the different events in the analytical chain.One of the aspects has been to sample and enrich analytes in vivo by the use of solid supported microdialysis, giving the advantage of almost real-time monitoring of analyte levels within a living host with targeted selectivity due to the analyte affinity for solid particles. Another aspect to selectively clean and enrich analytes in a complex matrix has been developed and automated on-line by the use of a column-switching technique before the analytical separation. By using several steps of extraction and separation coupled on-line to selected detection by the use of a triple quadrupole mass spectrometer facilitates great selectivity of species. The mass spectrometer also gives the ability to distinguish between isotopically labelled analogues coeluting with the analytes yielding the necessary accuracy for quantitative evaluation.Both development of analytical methods and clinical applications has been performed, as well as improvements of existing techniques, all to improve the quantitation of trace levels of targeted analytes in biofluids.
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| 28. |
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| 29. |
- Arvidsson, Björn, et al.
(författare)
-
Resource Decline in Higher Education – Perceptions and Consequences
- 2016
-
Ingår i: LTHs 9:e Pedagogiska Inspirationskonferens.
-
Konferensbidrag (refereegranskat)abstract
- Teaching students is one of the main tasks of LTH, as thousands of students engage on their engineering studies at the faculty every year. The funding for teaching these students is an essential source of income for LTH, but in recent years there has been an increased worry for diminishing financing for lecturing at the faculty.This study aims to investigate how lecturers perceive the development and what practical measures they have taken in their courses to counteract it. Interviews with ten lecturers at the department of Building and Environmental technology were performed. Many different practical strategies for dealing with the situation were documented during the interviews. The strategies are mainly focusing on making the students do more of the work on their own, e.g. working with the course literature. But the approaches to the problem varied greatly, as some lecturers tried to change as little as possible in order to save time, and others who saw a need for restructuring the entire educational program.
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| 30. |
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| 31. |
- Arvidsson, Inger, et al.
(författare)
-
Betydelsen av fysiska och psykosociala riskfaktorer för sjukdom/besvär i muskler och leder - En uppföljningsstudie av kvinnor inom vård och skola
- 2015
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Vi har upprättat en kohort med 1591 kvinnor från fem vanliga yrken: Operationssköterskor (Op), anestesisköterskor (Ane), undersköterskor på operation (Usk), biomedicinska analytiker som gör ultraljudsundersökningar (BMA) samt lärarinnor (Lär). Enkät har skickats ut vid baseline och i genomsnitt ca 28 månader därefter. Data från uppföljningen är inte analyserade ännu, varför rapporten enbart omfattar resultat från baseline. Fallen definierades baserat på kombinationen av frekvens och intensitet av rapporterade besvär. Samband mellan smärttillstånd och arbetsbelastning, individ- och livsstilsfaktorer analyserades med multivariat analys, backward proceedure. Samband påvisades för nacken med högt mekaniskt index, lågt fysiskt index, missnöje med datorarbetsplatsens utformning, höga krav, låg kontroll, höga känslomässiga krav, låga sensoriska krav samt låg ålder. axlarna med högt mekaniskt index, missnöjd med datorarbetsplatsens utformning, krav och lite egen tid för återhämtning. handleder/händer med högt mekaniskt index, höga krav, låg kontroll, hög ålder, högt BMI och inga/få hemmavarande barn. ländryggen med högt mekaniskt index, höga krav, låg kontroll, låga sensoriska krav, hög ålder, högt BMI och lite egen tid för återhämtning. fötterna med högt BMI, högt fysiskt index, hög ålder, höga krav, inga eller få hemmavarande barn samt låg kontroll. De ergonomiska problem som framkommit vid intervjuerna av operationspersonal har presenterats för studenter på Lunds tekniska högskola. Ett särskilt problem avsåg de statiska, obekväma och ansträngande arbetsställningarna som uppkom då operationssjuksköterskorna assisterade under operationer. Med hjälp av en operationhake höll de isär såret under operationen. Haken har ett grepp som tvingar Op till ett böjt och icke funktionellt handgrepp. Studenterna tog fram prototyp för en hållare till haken, som ger möjlighet till en mer ergonomisk handledsställning, samt att byta hand vid behov under operationen. Hållaren till haken utvärderas f n på två operationsavdelningar.
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| 32. |
- Arvidsson, Inger, et al.
(författare)
-
Burnout among Swedish school teachers - a cross-sectional analysis
- 2016
-
Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Teachers are at high risk of stress-related disorders. This study aimed to examine the occurrence of burnout in a sample of Swedish school-teachers, to test a combined measure of three burnout dimensions on the individual level, to characterize associations between burnout and factors encountered during work and leisure time, and to explore any differences between the genders. Methods: A questionnaire of occupational, sociodemographic and life-style factors was answered by 490 teachers in school years 4-9. Outcome measures were (a) the single burnout dimensions of exhaustion, cynicism and professional efficacy (Maslach Burnout Inventory-General Survey), and (b) a combined measure based on high or low values in the three dimensions. The combined measure was used to stratify the study population into four levels (0-3) of burnout. Multivariable Poisson regression was applied on level 2 + 3 vs. level 0 + 1, for variables that we considered as relevant risk factors for burn out. Results: Half of the teachers reported low values in all three dimensions (level 0), whereas 15 were classified as having high burnout in at least two out of the three dimensions (level 2 + 3), and 4 % in all three dimensions (level 3). Almost all psychosocial factors were incrementally more unfavourably reported through the rising levels of burnout, and so were dissatisfaction with the computer workstation, pain, sleep problems and lack of personal recovery. There was no association between gender and rising levels of overall burnout (p > 0.30). Low self-efficacy, poor leadership, high job demands and teaching in higher grades were the variables most clearly associated with burnout in multivariable Poisson regression. Conclusions: Even if circa 50 % of the teachers appear do well with respect to burnout, the results points to the need of implementing multifaceted countermeasures that may serve to reduce burnout.
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| 33. |
- Arvidsson, Inger, et al.
(författare)
-
Cross-sectional associations between occupational factors and musculoskeletal pain in women teachers, nurses and sonographers.
- 2016
-
Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 17:1
-
Tidskriftsartikel (refereegranskat)abstract
- It is usually assumed that musculoskeletal pain is associated with both the physical workload and the psychosocial work environment, as well as with personal and lifestyle factors. This study aims to ascertain the prevalence of musculoskeletal pain in women with varying or different occupational exposures, and to explore the associations between musculoskeletal pain and the occupational and personal factors.
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| 34. |
- Arvidsson, Inger, et al.
(författare)
-
Discrepancies in pain presentation caused by adverse psychosocial conditions as compared to pain due to high physical workload?
- 2012
-
Ingår i: Work: A Journal of Prevention, Assessment & Rehabilitation. - 1875-9270. ; 41, s. 2472-2475
-
Tidskriftsartikel (refereegranskat)abstract
- Disorders in the musculoskeletal system have been associated with a high physical workload as well as psychosocial and individual factors. It is however not obvious which of these factors that is most important to prevent. Musculoskeletal disorders in neck and upper extremity was assessed by interview and clinical examination in 79 teachers and 93 assisting nurses, all females. Psychosocial work environment was assessed by questionnaire. The physical workload was recorded by technical measurements of postures, movements and muscular load, in 9 teachers and 12 nurses. The physical workload was lower among the teachers, but they had a more demanding psychosocial work environment. Among the nurses, but not in the teachers, the neck-shoulder disorders were associated with a high body mass index (BMI). The teachers reported neck-shoulder complaints to a higher extent than the nurses, but had much lower prevalence of diagnoses in the clinical examination (12% vs. 25%; POR 0.3 CI 0.1 - 1.2; adjusted for age and BMI). The results suggest that adverse psychosocial conditions among the teachers give rise to a different kind of pain in the neck-shoulder region than from physical overload, troublesome but not as severe as the one afflicting the nurses.
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| 35. |
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| 36. |
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| 37. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
A crustal scarcity indicator for long-term global elemental resource assessment in LCA
- 2020
-
Ingår i: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 25:9, s. 1805-1817
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: How to assess impacts of mineral resources is much discussed in life cycle assessment (LCA). We see a need for, and a lack of, a mineral resource impact assessment method that captures the perspective of long-term global scarcity of elements. Method: A midpoint-level mineral resource impact assessment method matching this perspective is proposed, called the crustal scarcity indicator (CSI), with characterization factors called crustal scarcity potentials (CSPs) measured as kg silicon equivalents per kg element. They are based on crustal concentrations, which have been suggested to correlate with several important resource metrics (reserves, reserve base, reserves plus cumulative production, and ore deposits), thereby constituting proxies for long-term global elemental scarcity. Results and discussion: Ready-to-use CSPs are provided for 76 elements, through which the CSI can be calculated by multiplying with the respective masses of elements extracted from Earth’s crust for a certain product. As follows from their crustal concentrations, the three platinum-group metals iridium, osmium, and rhodium have the highest CSPs, whereas silicon, aluminum, and iron have the lowest CSPs. Conclusion: An evaluation of the CSPs and the characterization factors of four other mineral resource impact assessment methods in LCA (the abiotic depletion, the surplus ore, the cumulative exergy demand, and the EPS methods) were conducted. It showed that the CSPs are temporally reliable, calculated in a consistent way, and have a high coverage of elements in comparison. Furthermore, a quantitative comparison with the characterization factors of the four other methods showed that the CSPs reflect long-term global elemental scarcity comparatively well while requiring a minimum of assumptions and input parameters. Recommendations: We recommend using the CSI for assessments of long-term global elemental scarcity in LCA. Since the CSI is at the midpoint level, it can be complemented by other mineral resource impact assessment methods (both existing and to be developed) to provide a more comprehensive view of mineral resource impacts in an LCA.
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| 38. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Assessing the Environmental Risks of Silver from Clothes in an Urban Area
- 2014
-
Ingår i: Human and Ecological Risk Assessment (HERA). - : Informa UK Limited. - 1549-7860 .- 1080-7039. ; 20:4, s. 1008-1022
-
Tidskriftsartikel (refereegranskat)abstract
- The environmental risks from the use of silver-containing clothes (“silver clothes”)were assessed for an urban area. First, we evaluated whether the use of silver clothesmay cause contamination of wastewater treatment sludge that exceeds certain risk thresholds. Second, we assessed the risk of silver exposure to earthworms from applyingthe sludge as fertilizer to agricultural land. The most critical parameter was the concentration of silver in silver clothes, for which estimates in the literaturevary by more than five orders of magnitude. For concentrations at the high end of that parameter range, there is considerably increased concentration of silver in the sludge, and toxic effects on earthworms even at modest use rates of silver clothes suggest high risk. At the low end, no risks can be expected. The main recommendationfrom this study is that if silver is used in clothes, the silver concentration must be kept at the lower end of the range applied in this study if risks are to be avoided.This can be done either by design choices of companies, or by regulation. If the function of the applied silver is not maintained at these lower levels, the use of silver clothes should be minimized.
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| 39. |
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| 40. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Can carbon nanomaterials help avoiding resource scarcity?
- 2015
-
Ingår i: International Society of Industrial Ecology’s biennial conference, 7-10 July 2015, University of Surry, England.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The pressure on resource extraction is increasing due to a continued growth of world population and affluence. In particular, scarcity may become a pressing problem for several metals in the coming decades (Ljunggren Söderman et al. 2014). Carbon nanomaterials, such as fullerenes, carbon nanotubes, graphene and nanocellulose, have been suggested as a potential remedy for this. They have gained high interest in recent years, owing to their unique properties, which potentially could make them viable substitutes for a range of scarce and critical metals. However, carbon nanomaterials also require raw materials in order to be produced. Having carbon as main constituent, carbon nanomaterials require carbon feedstock of either renewable or fossil origin. Although carbon is an abundant element, not all chemical forms of carbon can be used directly for carbon nanomaterial production. The first aim of this study is to list potential raw materials for the carbon nanomaterials fullerenes, carbon nanotubes, graphene and nanocellulose. Second, raw material reserves available for future potential production rates of carbon nanomaterials are assessed. This analysis is done using prospective material flow analysis (MFA), which is a forward-looking type of MFA in contrast to the more traditional MFA that typically considers current material flows. Third, we outline which scarce materials that may be replaced by carbon nanomaterials in these applications. With this method, resource benefits from substitution and resource constraints of carbon nanomaterials can be assessed, both in the short and long term. Preliminary results show that the carbon nanomaterials investigated have the potential to replace a number of scarce materials. For example, graphene could replace indium and tin in transparent screens (Segal 2009). There may also be short term resource constraints for carbon nanomaterials. For example, graphene is currently suggested to be produced from graphite for some applications, and graphite has been listed as a critical material. We also discuss risks of competition over carbon feedstock (fossil and biomass) between current uses of carbon feedstock (e.g. plastics and wood) and carbon nanomaterials.
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| 41. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Carbon nanomaterials as potential substitutes for scarce metals
- 2017
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 156, s. 253-261
-
Forskningsöversikt (refereegranskat)abstract
- There is growing evidence of resource problems related to the use of scarce metals in society, includingthe long-term risk of world-wide depletion of high-grade ores, shorter-term supply deficits and mineralrelated conflicts. In this study, we explore the idea that scarce metals may be substituted by nanomaterialsbased on the abundant element carbon, primarily graphene, nanotubes and fullerenes. We depart from a list of 14 geochemically scarce metals: antimony, beryllium, chromium, cobalt, gallium, germanium, gold, indium, niobium, platinum, silver, tantalum, tin and tungsten. We then review scientific papers and patents for carbon nanomaterial technologies that, if successfully implemented, couldreduce or eliminate the need for each metal in its main application. For all main applications except forgold in jewelry, such technologies were identified. Most of the identified technologies were described inmore than 100 papers. This suggests that there is an ongoing promising development of carbon nanomaterialtechnologies for applications currently relying on scarce metals. However, we recommend further studies to scrutinize these technologies regarding their environmental performance to avoid problem shifting from metal scarcity to (eco)toxic effects of the carbon nanomaterials themselves orother impacts related to their production and use.
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| 42. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Challenges in Exposure Modeling of Nanoparticles in Aquatic Environments
- 2011
-
Ingår i: Human and Ecological Risk Assessment. - : Informa UK Limited. - 1080-7039 .- 1549-7860. ; 17:1, s. 245-262
-
Tidskriftsartikel (refereegranskat)abstract
- Managing the potential environmental risks of nanoparticles requires methods to link nanoparticle properties with macro-scale risks. This study outlines challenges in exposure modeling of nanoparticles in aquatic environments, such as the role of natural organic matter, natural colloids, fractal dimensions of agglomerates, coatings and doping of particles, and uncertainties regarding nanoparticle emissions to aquatic environments. The pros and cons of the exposure indicators mass concentration, particle number concentration, and surface area are discussed. By applying colloid chemistry kinetic equations describing particle agglomeration and sedimentation for the case of titanium dioxide nanoparticles, a limited exposure assessment including some of the factors mentioned is conducted with particle number concentration as the exposure indicator. The results of the modeling indicate that sedimentation, shear flows, and settling are of less importance with regard to particle number based predicted environmental concentrations. The inflow of nanoparticles to the water compartment had a significant impact in the model, and the collision efficiency (which is affected by natural organic matter) was shown to greatly affect model output. Implications for exposure modeling, regulation and science are discussed. A broad spectrum of scientific disciplines must be engaged in the development of exposure models where nano-level properties are linked to macro-scale risk.
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| 43. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Energy and resource use assessment of graphene as a substitute for indium tin oxide in transparent electrodes
- 2016
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 132, s. 289-297
-
Tidskriftsartikel (refereegranskat)abstract
- One of the most promising applications of graphene is as material in transparent electrodes in applications such as liquid crystal displays (LCDs) and solar cells. In this study, we assess life cycle resource requirements of producing an electrode area of graphene by chemical vapor deposition (CVD) and compare to the production of indium tin oxide (ITO). The resources considered are energy and scarce metals. The results show that graphene layers can have lower life cycle energy use than ITO layers, with 3–10 times reduction for our best case scenario. Regarding use of scarce metals, the use of indium in ITO production is more problematic than the use of copper in graphene production, although the latter may constitute a resource constraint in the very long run. The substitution of ITO by graphene thus seems favorable from a resource point of view. Higher order effects may outweigh or enhance the energy use benefit. For example, cheaper, graphene-based electrodes may spur increased production of LCDs, leading to increased absolute energy use, or spur the development of new energy technologies, such as solar cells and fuel cells. The latter could potentially lead to larger absolute reductions in resource use if these new technologies will replace fossil-based energy systems.
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| 44. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Energy use and climate change improvements of Li/S batteries based on life cycle assessment
- 2018
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 383, s. 87-92
-
Tidskriftsartikel (refereegranskat)abstract
- We present a life cycle assessment (LCA) study of a lithium/sulfur (Li/S) cell regarding its energy use (in electricity equivalents, kWhel) and climate change (in kg carbon dioxide equivalents, CO2 eq) with the aim of identifying improvement potentials. Possible improvements are illustrated by departing from a base case of Li/S battery design, electricity from coal power, and heat from natural gas. In the base case, energy use is calculated at 580 kWhel kWh−1 and climate change impact at 230 kg CO2 eq kWh−1 of storage capacity. The main contribution to energy use comes from the LiTFSI electrolyte salt production and the main contribution to climate change is electricity use during the cell production stage. By (i) reducing cell production electricity requirement, (ii) sourcing electricity and heat from renewable sources, (iii) improving the specific energy of the Li/S cell, and (iv) switching to carbon black for the cathode, energy use and climate change impact can be reduced by 54 and 93%, respectively. For climate change, our best-case result of 17 kg CO2 eq kWh−1 is of similar magnitude as the best-case literature results for lithium-ion batteries (LIBs). The lithium metal requirement of Li/S batteries and LIBs are also of similar magnitude.
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| 45. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Environmental Assessment of Emerging Technologies: Recommendations for Prospective LCA
- 2018
-
Ingår i: Journal of Industrial Ecology. - : Wiley. - 1530-9290 .- 1088-1980. ; 22:6, s. 1286-1294
-
Forskningsöversikt (refereegranskat)abstract
- The challenge of assessing emerging technologies with life cycle assessment (LCA) has been increasingly discussed in the LCA field. In this article, we propose a definition of prospective LCA: An LCA is prospective when the (emerging) technology studied is in an early phase of development (e.g., small-scale production), but the technology is modeled at a future, more-developed phase (e.g., large-scale production). Methodological choices in prospective LCA must be adapted to reflect this goal of assessing environmental impacts of emerging technologies, which deviates from the typical goals of conventional LCA studies. The aim of the article is to provide a number of recommendations for how to conduct such prospective assessments in a relevant manner. The recommendations are based on a detailed review of selected prospective LCA case studies, mainly from the areas of nanomaterials, biomaterials, and energy technologies. We find that it is important to include technology alternatives that are relevant for the future in prospective LCA studies. Predictive scenarios and scenario ranges are two general approaches to prospective inventory modeling of both foreground and background systems. Many different data sources are available for prospective modeling of the foreground system: scientific articles; patents; expert interviews; unpublished experimental data; and process modeling. However, we caution against temporal mismatches between foreground and background systems, and recommend that foreground and background system impacts be reported separately in order to increase the usefulness of the results in other prospective studies.
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| 46. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Environmental Impact of Titanium Dioxide Nanoparticles – Applying Life Cycle Thinking and Risk Assessment for Swedish Conditions
- 2008
-
Ingår i: 3rd International Conference on the Environmental Effects of Nanoparticles and Nanomaterials, Birmingham University, Birmingham, UK, September 15-16, 2008.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The risks of nanoparticles have been issued by several different groups, e.g. The Royal Society (2004) and Friends of the Earth (2006), and the concept nanotoxicology has been introduced to underline the distinctive toxicological features of nanoparticles (Oberdörster et al. 2005). Some nanoparticles, such as carbon nanotubes, have been outlined as hazardous and great caution has been suggested before introducing carbon nanotubes into the market (Poland et al. 2008). According to a risk assessment performed by Mueller and Nowack (2007), titanium dioxide nanoparticles had higher predicted environmental concentration compared with the predicted no effect concentration than both silver nanoparticles and carbon nanotubes, and further detailed studies regarding titanium dioxide nanoparticles were suggested. However, no sensitivity analysis was performed in Mueller and Nowack (2007), and a crude model was used to model environmental faith of the titanium dioxide nanoparticles. Our study applied substance flow analysis in order to facilitate a comprehensive environmental risk assessment of titanium dioxide nanoparticles (see e.g. Tsunemi and Wada (2008) and Fuster et al. (2002)). A detailed investigation of the production of titanium dioxide nanoparticles and their application in society was performed facilitating hazard identification according to Hansen et al. (2007). Emissions were calculated based on use assumptions and a modelling of the environmental faith of the titanium dioxide nanoparticles was attempted including the particle aggregation and interaction with natural organic substances that modify bioavailability. Predicted environmental concentrations were calculated and compared with predicted no effect concentrations according to several ecotoxicological studies and in order to assess the uncertainty a sensitivity analysis was performed for input parameters.
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| 47. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Fate modeling of titanium dioxide nanoparticles in the water compartment by colloid chemistry
- 2009
-
Ingår i: 1st International Conference on the Environmental Implications and Applications of Nanotechnology, June 9-11, 2009, Amherst, U.S.A..
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Titanium dioxide is one of the most produced nanoparticles according to the Project of Emerging Nanotechnologies (www.nanotechproject.org). According to Mueller and Nowack (2008) it is also the nanoparticle that has the largest environmental concentration in the Swiss water compartment, 16 µg/l according to their high estimate. Further, Boxall et al. (2007) estimate a titanium dioxide nanoparticle environmental concentration of 24.5 µg/l in the UK water compartment for a scenario that probably overestimates the current exposure levels. However, neither of these risk models take fate processes such as aggregation and sedimentation into account. Colloid chemistry deals with particles within the size range of 1 nm to 1 µm. Nanoparticles of a size between one nanometer and a few hundred nanometers are thus well within the colloid range. Theories of colloid chemistry suggest that sedimentation of nanoparticles depends mainly on the density and the viscosity of the water and the density and size of the particles. Sedimentation is shown not to be an important factor, since the sedimentation of particles smaller than ~300 nm is negligible. Aggregation is a more complex process which depends on factors such as temperature, salinity, ion valence, pH, point of zero charge, the Hamaker constant, particle size and particle concentration (Elimelech et al. 1995). These factors were estimated for a typical Swedish lake and calculations were performed in MATLAB. The aggregation is modeled by kinetics according to Smoluchowski (1917) but adjusted according to the DLVO theory (see Elimelech et al. 1995). Preliminary results show that aggregation can reduce the predicted environmental concentration significantly in a short time. It would take less than 4 minutes for the initial environmental concentrations predicted by both Mueller and Nowack (2008) and Boxall et al. (2007) to be reduced by 50%. After 24 hours, both predicted environmental concentrations would have fallen below 0.1 µg/l.
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| 48. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
How to make policy-relevant life cycle assessments of future products? Lessons learned from nanomaterials
- 2013
-
Ingår i: 6th International Conference on Life Cycle Management, Gothenburg, 25-28 August.
-
Konferensbidrag (refereegranskat)abstract
- Many new nanomaterials are currently being developed, and there is a great demand from policy-makers such as governments and agencies to understand the future environmental impact of nanomaterials. However, assessing the life cycle environmental impacts, e.g. in terms of emissions and energy use, related to these materials and products that contain them constitutes a great challenge, which makes it difficult to meet such needs from policy-makers. The challenge is much due to the many uncertainties that surround new nanomaterials at an early point of technological development, which makes environmental assessment methods such as life cycle assessment difficult to apply. These uncertainties include the future areas of application of the nanomaterial, future designs of products within those areas, and future production processes. When one or more of these uncertainties are present, we say that the life cycle or product chain is embryonic. This embryonic nature of nanomaterial life cycles differentiates them from the life cycles of more established products, such as cups and cucumbers. Assessing the environmental impacts of embryonic nanomaterial life cycles requires the assessor to understand the future, or rather some aspects of a number of possible futures. Hence, we need to make use of methods belonging to the field of future studies, including monitoring of trends in technology development (e.g. via patent analysis) and application areas as well as predicting and exploring by trend analysis, expert judgement, and sometimes even fantasizing. We illustrate the theoretical concept of embryonic life cycles with a number of examples of embryonic nanomaterial life cycles, including carbon nanotubes in composites, titanium dioxide nanoparticles in self-cleaning cement and graphene in electronic devices and composites. We show that a range of future study approaches may enrich, or even be essential to, policy-relevant life cycle assessments. We also show that environmental assessments such as life cycle assessment can be misused or used in questionable ways when applied to embryonic life cycles with the purpose of obtaining policy-relevant results.
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| 49. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Impacts of a Silver-Coated Future - Particle Flow Analysis of Silver Nanoparticles
- 2011
-
Ingår i: Journal of Industrial Ecology. - 1530-9290 .- 1088-1980. ; 15:6, s. 844-854
-
Tidskriftsartikel (refereegranskat)abstract
- Silver is a compound that is well known for its adverse environmental effects. More recently, silver in the form of silver nanoparticles (Ag NPs) have begun to be produced in increasingly larger amounts for antibacterial purposes in for instance textiles, wound dressings and cosmetics. Several authors have highlighted the potential environmental impact of these NPs. In order to contribute to a risk assessment of Ag NPs, a suggested method named particle flow analysis is applied to estimate current emissions from society to the environment. In addition, explorative scenarios are set up to account for potential technology diffusion of selected Ag NP applications. The results are uncertain and need to be refined, but they indicate that emissions from all applications included may increase significantly in the future. Ag NPs in textiles and electronic circuitry may increase more than in wound dressings due to the limited consumption of wound dressings. Due to the dissipative nature of Ag NPs in textiles, the results indicate that they may cause the highest emissions in the future, thus partly confirming the woes of both scientists and environmental organizations. Gaps in current knowledge have been identified. Especially the fate of Ag NPs during different waste handling processes is outlined as an area that requires more research.
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| 50. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Is graphene a ”wonder material” also from an environmental life cycle perspective?
- 2014
-
Ingår i: Abstract of Papers of the American Chemical Society. - 0065-7727. ; 247
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The nanomaterial graphene has attracted great interest for its many potential applications, including composites and electronic devises, and has been referred to by some as a "wonder material" from a technical point of view. However, the question remains whether graphene is also a "wonder material" from an environmental life cycle perspective. In order to investigate this, we applied life cycle assessment (LCA) to assess the cradle-to-gate environmental impacts of graphene production. The focus of the assessment was on the foreground system and on more inherent impact categories, namely energy use, water use, human toxicity, and ecotoxicity. Two different production routes were investigated. In the first, called chemical reduction, graphite is first oxidized to graphite oxide, and then reduced by hydrazine to form graphene sheets in solution that could be used in e.g. composites. The second is ultrasonication, where graphite is exposed to ultrasound, and thereby breaks up into graphene sheets in solution, also possible to use in composites. These two routes were compared on a kg of graphene basis. The results indicate that ultrasonication has a considerably lower cradle-to-gate impact than chemical reduction for all included impact categories. For example, the energy use of chemical reduction-made graphene appears to be more than 100 times higher than that of ultrasonication-made graphene. Comparing to the energy use of other nanomaterials, chemical reduction-based graphene appears to have an energy use close to the median. Ultrasonication-made graphene, however, appears to have a lower energy use than any previously assessed nano material. This implicates that the chemical industry should focus their efforts on developing the ultrasonication production route rather than chemical reduction.
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