| 1. |
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| 2. |
- Betancourt, Lazaro Hiram, et al.
(författare)
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The human melanoma proteome atlas-Defining the molecular pathology
- 2021
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Ingår i: Clinical and Translational Medicine. - : Wiley. - 2001-1326. ; 11:7, s. 1-20
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Tidskriftsartikel (refereegranskat)abstract
- The MM500 study is an initiative to map the protein levels in malignant melanoma tumor samples, focused on in-depth histopathology coupled to proteome characterization. The protein levels and localization were determined for a broad spectrum of diverse, surgically isolated melanoma tumors originating from multiple body locations. More than 15,500 proteoforms were identified by mass spectrometry, from which chromosomal and subcellular localization was annotated within both primary and metastatic melanoma. The data generated by global proteomic experiments covered 72% of the proteins identified in the recently reported high stringency blueprint of the human proteome. This study contributes to the NIH Cancer Moonshot initiative combining detailed histopathological presentation with the molecular characterization for 505 melanoma tumor samples, localized in 26 organs from 232 patients.
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| 3. |
- Molarius, Anu, et al.
(författare)
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Mental health symptoms in relation to socio-economic conditions and lifestyle factors : a population-based study in Sweden
- 2009
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Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 9, s. 302-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Poor mental health has large social and economic consequences both for the individual and society. In Sweden, the prevalence of mental health symptoms has increased since the beginning of the 1990s. There is a need for a better understanding of the area for planning preventive activities and health care. Methods: The study is based on a postal survey questionnaire sent to a random sample of men and women aged 18-84 years in 2004. The overall response rate was 64%. The area investigated covers 55 municipalities with about one million inhabitants in central part of Sweden. The study population includes 42,448 respondents. Mental health was measured with self-reported symptoms of anxiety/depression (EQ-5D, 5th question). The association between socio-economic conditions, lifestyle factors and mental health symptoms was investigated using multivariate multinomial logistic regression models. Results: About 40% of women and 30% of men reported that they were moderately or extremely anxious or depressed. Younger subjects reported poorer mental health than older subjects, the best mental health was found at ages 65-74 years. Factors that were strongly and independently related to mental health symptoms were poor social support, experiences of being belittled, employment status (receiving a disability pension and unemployment), economic hardship, critical life events, and functional disability. A strong association was also found between how burdensome domestic work was experienced and anxiety/depression. This was true for both men and women. Educational level was not associated with mental health symptoms. Of lifestyle factors, physical inactivity, underweight and risk consumption of alcohol were independently associated with mental health symptoms. Conclusion: Our results support the notion that a ground for good mental health includes balance in social relations, in domestic work and in employment as well as in personal economy both among men and women. In addition, physical inactivity, underweight and risk consumption of alcohol are associated with mental health symptoms independent of socio-economic factors.
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| 4. |
- Smith, Frida, 1973, et al.
(författare)
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Exploring the meaning, role and experiences of a patient-led social innovation for people affected by cancer: a new collaborative care model complementing traditional cancer rehabilitation in Sweden
- 2021
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Ingår i: BMJ open quality. - : BMJ. - 2399-6641. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Objective Kraftens Hus is the first support centre in Sweden designed by and for people affected by cancer, including patients, family, friends, staff members and local community representatives (collectively 'stakeholders'). The purpose of this study was to explore the meaning, role and experiences of Kraftens Hus stakeholders using a patient and public involved methodology. Methods To understand and map the experiences of visitors to Kraftens Hus, we applied concept mapping (CM), a mixed methods approach where data are collected and analysed in four structured steps designed to capture the diverse perspectives of multiple stakeholders. Qualitative interviews with relevant stakeholders supplemented the CM findings. Results The final concept map contained six clusters of ideas. Within the clusters, there was a recurring theme that cancer-affected people value accessible and long-term psychosocial support (PSS). The intended emotional, social and practical needs identified in a previous design process seem to have been addressed and appreciated by Kraftens Hus visitors. Conclusion Kraftens Hus is an example of a new patient-led social innovation based on a life-event perspective and integration of resources from different sectors in society. By focusing on life, not the disease, the care continuum expands, and long-term PSS is provided alongside cancer treatment. The evaluation confirms that PSS should focus on health and well-being in the broadest sense.
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| 5. |
- Winqvist, Marianne, et al.
(författare)
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Stöd till anhöriga : erfarenheter från åtta kommuner 2010-2012
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett omfattande arbete har utförts i landets kommuner sedan slutet av 1990-talet för att utveckla stödet till anhöriga. Staten har bidragit med cirka enmiljard kronor i stimulansmedel och en förändring har införts i Socialtjänstlagen som innebär att kommunerna har en skyldighet att erbjuda anhöriga stöd.I denna undersökning kartläggs och följs stödet till anhöriga under tre år i åtta kommuner. De studerade kommunerna är Borås, Härjedalen, Hässleholm, Malmö, Skara, Strängnäs, Uppsala och Västervik. I rapporten presenteras resultatet av kartläggningen för år 2010. Syftet med studien är att:Kartlägga innehållet i stödet till anhöriga, hur stödet organiseras, planeras,följs upp och utvärderas inom äldre-, funktionshinder- och individ-och familjeområdet samt samverkan mellan kommun, landsting,ideella organisationer och andra aktörer inom området.Undersöka hur de olika huvudintressenterna bedömer kvaliteten påstödet till anhöriga.Under tre år följa utvecklingen i de kommuner/kommundelar som ingår i studien.
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| 6. |
- Ahlstedt, Carina, et al.
(författare)
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Flourishing at work : Nurses' motivation through daily communication - An ethnographic approach
- 2020
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Ingår i: Nursing and Health Sciences. - Australia : John Wiley & Sons. - 1441-0745 .- 1442-2018. ; 22:4, s. 1169-1176
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Tidskriftsartikel (refereegranskat)abstract
- Shortage and turnover of registered nurses are worldwide challenges, and work motiva-tion is one factor in retaining staff in the healthcare sector. The aim of this study was toexplore registered nurses' motivation expressed in daily communication, using the basicneeds in self-determination theory as a framework. A secondary analysis of ethno-graphic data, collected through participant observations, informal interviews duringobservations, and individual interviews, was used. A total sample of all registered nursesemployed at a hospital unit in Sweden (n = 10) participated. The data were analyzed the-matically through the lens of the basic needs in self-determination theory: autonomy,competence, and relatedness. Self-regulation of learning, the possibilities to discuss work-related challenges with colleagues, and having registered nurses lead dialogues with phy-sicians were factors connected to autonomy. Having a registered nurse and physiciansolve problems together was a factor connected to competence.Asenseofbelongingand security in a permissive climate between registered nurses was co nnected to relat-edness. This paper has implications for increased awareness of the three basic motiva-tional needs, which could be used in the development of attractive workplaces
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| 7. |
- Ahlstedt, Carina, 1969-, et al.
(författare)
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What makes registered nurses remain in work? : An ethnographic study
- 2019
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Ingår i: International Journal of Nursing Studies. - : Elsevier Ltd. - 0020-7489 .- 1873-491X. ; 89, s. 32-38
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Tidskriftsartikel (refereegranskat)abstract
- Background: Registered nurses’ work-related stress, dissatisfaction and burnout are some of the problems in the healthcare and that negatively affect healthcare quality and patient care. A prerequisite for sustained high quality at work is that the registered nurses are motivated. High motivation has been proved to lead to better working results. The theory of inner work life describes the dynamic interplay between a person's perceptions, emotions and motivation and the three key factors for a good working life: nourishment, progress and catalysts. Objectives: The aim of the study was to explore registered nurses’ workday events in relation to inner work life theory, to better understand what influences registered nurses to remain in work. Design: A qualitative explorative study with an ethnographic approach. Methods: Participant observation over four months; in total 56 h with 479 events and 58 informal interviews during observation; all registered nurses employed at the unit (n = 10) were included. In addition, individual interviews were conducted after the observation period (n = 9). The dataset was analysed using thematic analysis and in the final step of the analysis the categories were reflected in relation to the three key factors in theory of inner work life. Results: Nourishment in a registered nurse context describes the work motivation created by the interpersonal support between colleagues. It was important to registered nurses that physicians and colleagues respected and trusted their knowledge in the daily work, and that they felt comfortable asking questions and supporting each other. Progress in the context of registered nurses’ work motivation was the feeling of moving forward with a mix of small wins and the perception of solving more complex challenges in daily work. It was also fundamental to the registered nurses’ development through new knowledge and learning during daily work. Catalysts, actions that directly facilitate the work, were highlighted as the possibility to work independently along with the opportunity to work together with other registered nurses. Conclusion: This study has a number of implications for future work and research on creating an attractive workplace for registered nurses. Working independently, with colleagues from the same profession, integrated with learning, visible progress, and receiving feedback from the work itself, contribute to work motivation.
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| 8. |
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| 9. |
- Andersson, Carina, et al.
(författare)
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Design fixations among information design students : What has been seen cannot be unseen
- 2012
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Ingår i: Proceedings of the 14th International Conference on Engineering and Product Design Education: Design Education for Future Wellbeing, EPDE 2012. - 9781904670360 ; , s. 159-166
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Konferensbidrag (refereegranskat)abstract
- This research explores the phenomenon of design fixation by studying undergraduate design students undertaking an information product design problem. The research is based on a case study, with 64 students. The students were given a design problem, and their design processes were documented in a weblog, which was analyzed jointly with handouts and slide presentations. The research suggests that the formulation of ideas in and recording of an early group brainstorming sessions may contribute to fixation of the finale design solution.
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| 10. |
- Andersson, Carina, 1970-
(författare)
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Informationsdesign i tillståndsövervakning : En studie av ett bildskärmsbaserat användargränssnitt för tillståndsövervakning och tillståndsbaserat underhåll
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This research concerns the information design and visual design of graphical user interfaces (GUI) in the condition monitoring and condition-based maintenance (CBM) of production equipment. It also concerns various communicative aspects of a GUI, which is used to monitor the condition of assets. It applies to one Swedish vendor and its intentions to design information. In addition, it applies to the interaction between the GUI and its individual visual elements, as well as the communication between the GUI and the users (in four Swedish paper mills).The research is performed as a single case study. Interviews and observations have been the main methods for data collection. Empirical data is analyzed with methods inferred to semiotics, rhetoric and narratology. Theories in information science and regarding remediation are used to interpret the user interface design.The key conclusion is that there are no less than five different forms of information, all important when determining the conditions of assets. These information forms include the words, images and shapes in the GUI, the machine components and peripherals equipment, the information that takes form when personnel communicate machine conditions, the personnel’s subjective associations, and the information forms that relate to the personnel's actions and interactions.Preventive technicians interpret the GUI-information individually and collectively in relation to these information forms, which influence their interpretation and understanding of the GUI information. Social media in the GUI makes it possible to represent essential information that takes form when employees communicate a machine’s condition. Photographs may represent information forms as a machine’s components, peripherals, and local environment change over time. Moreover, preventative technicians may use diagrams and photographs in the GUI to change attitudes among the personnel at the mills and convince them, for example, of a machine’s condition or the effectiveness of CBM as maintenance policy.
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| 11. |
- Anund, Anna, 1964-, et al.
(författare)
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Utvärderingsmodell för ITS-baserade system vid hållplats : kunskapsöversikt och förslag på forskningsbehov
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det finns nya produkter av typen varningssystem som syftar till att öka säkerhet och trygghet för oskyddade trafikanter. De har ofta tagits fram med särskilt fokus på barn. Produktutvecklarna har utvärderat sina produkter med positiva resultat och intresset hos Trafikverket och kommuner är stort för flera av dessa produkter. En typ av system är utmärkning vid hållplatser där blinkande ljus aktiveras när det finns oskyddade trafikanter i närheten, ett så kallat ITS-baserat varningssystem. Det finns idag ett antal platser i landet där sådana anläggningar är i bruk som ”försök” och det har skett utvärderingar av valda system vid hållplats som visat att systemen sannolikt är effektiva när det gäller att reducera hastigheten hos förbipasserande. Det finns dock en avsaknad av ett samlat utvärderingsupplägg. Avsaknaden av systematisk utvärdering har bidragit till bristen på formella beslut för att integrera denna typ av produkt i Vägar och Gators Utformning, VGU eller i Trafiklagstiftningen. I Trafikverkets region Stockholm har man utifrån resenärernas behov och i samarbete med kommunerna kring glesbygdsproblematik, särskilt intresse i att dessa produkter blir möjliga att använda. En förutsättning för detta är en systematisk utvärdering med avseende på om ett specifikt system fyller den funktion som det var avsett att fylla.
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| 12. |
- Beausang, Angela, et al.
(författare)
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"Möjligheten att rädda några av dessa kvinnors liv har inte vägts in"
- 2014
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Ingår i: Dagens Medicin. - : Dagens Medicin.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Namnet på Socialstyrelsens vägledning lyder: Hur upptäcka våldsutsatthet? Ja, det kan man verkligen fråga sig efter att ha läst detta föga vägledande dokument, skriver ett stort antal kritiska debattörer.
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| 13. |
- Bergquist, Magnus, 1960, et al.
(författare)
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Combining Actor Network Theory and Genre Theory to Understand the Evolution of Digital genres
- 2008
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Ingår i: Proceedings of the JAIS Theory Development Workshop. Sprouts Working Papers on Information Systems. - Amsterdam : Sprouts Alliance. ; 8:20, s. 36-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we argue that a combination of Actor-Network Theory (ANT) and Genre Theory can constitute a theoretical framework for understanding how digital genres evolve. Genre theory states that genres evolve over time through reciprocal interaction between institutionalized practices and individual action; that they develop from actors’ responses to recurrent situations, and are shaped around characteristics as content, form, functionality and purpose. Genres emerge out of practice and at the same time they shape that practice. While genre theory can describe the characteristics of a genre, it cannot handle the process of how a genre is formed and what powers and forces are involved in this shaping process. In order to address this problem, several authors have incorporated structuration theory into genre analysis. However, structuration theory can only catch these constitutional processes of genre in a very broad manner. As a genre is evolving and stabilizing over time in interplay with different actors, it goes beyond what is possible to explain only by means of structuration theory. Instead, ANT could work as a tool to capture the process of how a genre takes form in negotiations with different stakeholders. In this paper we discuss how genre theory and ANT can be combined in a framework for analyzing emerging genres. We apply this theoretical framework on an e-newspaper project that embodies a new genre in the making. We will here show how evolving genre characteristics are developed, formed and stabilized in a negotiation and struggle between the involved actors when they translate their interests in ways that finally are resulting in a new genre.
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| 14. |
- Bergvall-Kåreborn, Birgitta, et al.
(författare)
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A Milieu for Innovation : Defining Living Labs
- 2009
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Ingår i: Stimulating recovery. - New York : ISPIM. - 9789522148643 - 9522148644 ; , s. 12-
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Konferensbidrag (refereegranskat)abstract
- A new trend of user involvement in open innovation processes has emerged. Concurring with this trend the Living Lab concept has been re-vitalized. This concept has attracted attention lately, but there exist no coherent view. In this paper we discuss and define the concept and propose five key components and five key principles for Living Labs based on experiences from over 30 development and research projects within two Living Labs, Botnia Living Lab and Halmstad Living Lab. The key components are: ICT & Infrastructure; Management; Partners & Users; Research; and Approach. The key principles are: Openness; Influence; Realism; Value; and Sustainability. Our proposed definition of a Living Lab is: A Living Lab is a user-centric innovation milieu built on every-day practice and research, with an approach that facilitates user influence in open and distributed innovation processes engaging all relevant partners in real-life contexts, aiming to create sustainable values.
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| 15. |
- Bergvall-Kåreborn, Birgitta, et al.
(författare)
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A Model for Reflective Participatory Design : The Role of Participation, Voice and Space
- 2015
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Ingår i: 21st Americas Conference on Information Systems. - : Americas Conference on Information Systems. - 9780996683104
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Konferensbidrag (refereegranskat)abstract
- This paper aims to contribute to the participatory tradition in health informatics by presenting a model for reflective participatory design emerging from qualitative fieldwork in a participatory project aimed to improve the health and wellbeing of older people in the northern periphery regions of Europe, through new mobile services. The model brings together two established processes in novel ways: systems development and user participation. Within each process three concepts are presented to facilitate discussion and reflection at the concept level, the process level and the integrated process level.
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| 16. |
- Bergvall-Kåreborn, Birgitta, 1968-, et al.
(författare)
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Places and Spaces - Their Influence on Innovation Milieus and Innovation Processes
- 2015
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Ingår i: Proceedings of the 2015 ISPIM Conference in Budapest, June 14-17. - : International Society for Professional Innovation Management (ISPIM).
-
Konferensbidrag (refereegranskat)abstract
- Intensified and matured use of internet-based technologies aimed to facilitate development and innovation are increasingly characterized by a mixture of physical and digital locations; commonly referred to as places and spaces. The aim of this paper was therefore to identify different types of places and spaces central for the innovation milieus and processes of Living Lab projects, illustrate their impact on both process and results, and develop guidelines for space that can be designed in order to facilitate value-driven and democratized innovation. Based on a literature review and a cross case analyses different aspects of space, relevant for Innovation and Living Lab studies, have been identified: 1) local-global; 2) physical and digital, and 3) private-public. In the paper we focus on these concepts as tools for understanding present day innovation and we examples of how digital technology has influenced placement and permeability in relation to place and space.
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| 17. |
- Bergvall-Kåreborn, Birgitta, et al.
(författare)
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Places and Spaces within Living Labs
- 2015
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Ingår i: Technology Innovation Management Review. - Ottawa, ON : Carleton University. - 1927-0321. ; 5:12, s. 37-47
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we propose the concepts of places and spaces as conceptual tools to facilitate the organization of innovation activities within living labs. We have taken a pragmatic perspective on these concepts regarding how they are integrated in design situations, and how different types of places and spaces can facilitate or hinder innovation. We have found that, by applying openness, realism, and influence in the different spaces of our living lab milieus, they have transformed into many different places depending on the stakeholders involved, the methods chosen, and the facilitation of activities. Hence, by understanding this line of reasoning, living lab managers can make more informed decisions and plans for innovation activities.
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| 18. |
- Bernardo, Carina, et al.
(författare)
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Molecular pathology of the luminal class of urothelial tumors
- 2019
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Ingår i: Journal of Pathology. - : Wiley. - 0022-3417 .- 1096-9896. ; 249:3, s. 308-318
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Tidskriftsartikel (refereegranskat)abstract
- Molecular subtypes of urothelial carcinoma may be divided into luminal and nonluminal tumors. Nonluminal tumors are composed of cases with basal/squamous-like or small cell/neuroendocrine features, with a consensus on the molecular characteristics of the respective subtype. In contrast, luminal tumors are more disparate with three to five suggested subtypes and with definitions that do not always cohere. To resolve some of these disparities we assembled a cohort of 344 luminal tumors classified as urothelial-like (Uro), with the subtypes UroA, UroAp, UroB, and UroC, or genomically unstable (GU) according to the LundTax system. Cases were systematically analyzed by immunohistochemistry using antibodies for proteins representing important biological processes or cellular states: KRT5, EGFR, and CDH3 for the integrity of a basal cell layer; CCNB1, Ki67, and FOXM1 for proliferation; FGFR3 and ERBB2 for receptor tyrosine kinase status; CCND1, CDKN2A(p16), RB1, and E2F3 for cell cycle regulation; PPARG, GATA3, and TP63 for the differentiation regulatory system; and KRT20 and UPK3 for the differentiation readout. We show that Uro tumors form one, albeit heterogenous, group characterized by FGFR3, CCND1, and RB1 expression, but low or absence of CDKN2A(p16) and ERBB2 expression. The opposite expression pattern is observed in GU cases. Furthermore, Uro tumors are distinguished from GU tumors by showing a high RB1/p16 expression ratio. Class defining characteristics were independent of pathological stage and growth pattern, and thus intrinsic. In Uro tumors, proliferation was limited to a well-defined single layer of basal-like cells in UroA tumors but occurred throughout the tumor parenchyma, independent of the basal layer, in the more progressed UroAp and UroC tumors. A similar change in proliferation topology was not observed in GU. We conclude that luminal urothelial carcinomas consist, at the molecular pathology level, of two major subtypes, the larger heterogenous Uro and the biologically distinct GU subtype.
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| 19. |
- Bernardo, Carina, et al.
(författare)
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Molecular pathology of the non-luminal Ba/Sq-like and Sc/NE-like classes of urothelial tumours : An integrated immunohistochemical analysis
- 2022
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Ingår i: Human Pathology. - : Elsevier BV. - 0046-8177. ; 122, s. 11-24
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Tidskriftsartikel (refereegranskat)abstract
- Several groups have during past years produced molecular classification schemes for bladder cancer. Even though no consensus on how to define a subtype exists, one approach has been to base definitions on how tumours cluster according to their mRNA expression profiles. In many cases, obtained profiles, and thus class defining features, are affected by signals from non-tumour cells within the biopsy. To overcome this issue, we combined gene expression analyses with analyses of the actual tumour cells by extensive immunohistochemistry (IHC). By this approach we were able to define tumour cell phenotypes i.e., subtypes defined by features of the tumour cells only, and adjust mRNA-based algorithms accordingly. In the present investigation we address the non-luminal Basal/Squamous-like (Ba/Sq) and Small cell/Neuroendocrine-like (Sc/NE) categories of tumours defined by mRNA-based classification. We make use of IHC data for 15 proteins, all known to be instrumental for defining molecular subtypes of urothelial carcinoma. We show that the UroB type of tumours, frequently grouped together with Ba/Sq, are different from the Ba/Sq entity at several essential features and is a derivative of Urothelial-like tumours (Uro). We show that the Sc/NE tumours are similar to but represents extreme versions of Genomically Unstable (GU) tumours. We apply clustering to 423 cases representing all subtypes using IHC data for 14 proteins and show that the obtained grouping conforms well with the mRNA-based classification. This work describes in detail the molecular pathology of non-luminal RNA-based bladder cancer subtypes and highlight similarities/dissimilarities suggestive of origin.
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| 20. |
- Brown, Rosemary, 1990, et al.
(författare)
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Surface Composition of a Highly Active Pt3Y Alloy Catalyst for Application in Low Temperature Fuel Cells
- 2020
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Ingår i: Fuel Cells. - : Wiley. - 1615-6846 .- 1615-6854. ; 20:4, s. 413-419
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Tidskriftsartikel (refereegranskat)abstract
- Currently, platinum is the most widely used catalyst for low temperature proton exchange membrane fuel cells (PEMFC). However, the kinetics at the cathode are slow, and the price of platinum is high. To improve oxygen reduction reaction (ORR) kinetics at the cathode, platinum can be alloyed with rare earth elements, such as yttrium. We report that Pt3Y has the potential to be over 2 times more active for the ORR compared with Pt inside a real fuel cell. We present detailed photoemission analysis into the nature of the sputtered catalyst surface, using synchrotron radiation photoelectron spectroscopy (SRPES) to examine if surface adsorbates or impurities are present and can be removed. Pretreatment removes most of the yttrium oxide in the surface leaving behind a Pt overlayer which is only a few monolayers thick. Evidence of a substochiometric oxide peak in the Y 3d core level is presented, this oxide extends into the surface even after Ar+ sputter cleaning in-situ. This information will aid the development of new highly active nanocatalysts for employment in real fuel cell electrodes.
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| 21. |
- Butori, Martina, et al.
(författare)
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The effect of oxygen partial pressure and humidification in proton exchange membrane fuel cells at intermediate temperature (80-120 degrees C)
- 2023
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 563, s. 232803-
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Tidskriftsartikel (refereegranskat)abstract
- The integration of proton exchange membrane fuel cells (PEMFCs) in heavy-duty vehicles would be facilitated if operating temperatures above 100 degrees C were possible. In this work, the effect of temperature in the intermediate range of 80-120 degrees C is investigated for a commercial membrane electrode assembly (MEA) through polarization curves and electrochemical impedance spectroscopy. The importance of oxygen partial pressure on voltage is systematically studied by decoupling it from humidity and temperature. The results show that adequate oper-ation at intermediate temperature is achievable if the oxygen partial pressure is sufficient. Although the cathode kinetics is faster with rising temperatures, the voltage gain is counteracted by the decreasing equilibrium po-tential. At intermediate temperature, the water transport is enhanced, levelling out the relative humidity dif-ference between anode and cathode. However, ionic conductivity in the polymer can become limiting at high currents, due to a smaller relative humidity increase at these temperatures. To conclude, a higher operating temperature does not inherently cause a decrease in obtained current density. Rather, the difficulty to simul-taneously have sufficient oxygen partial pressure and high relative humidity causes limitations within the cathode that to some extent can be solved by pressurizing the cell.
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| 22. |
- Carlson, Annika, et al.
(författare)
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Electrode parameters and operating conditions influencing the performance of anion exchange membrane fuel cells
- 2018
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Ingår i: Electrochimica Acta. - : Elsevier. - 0013-4686 .- 1873-3859. ; 277, s. 151-160
-
Tidskriftsartikel (refereegranskat)abstract
- A deeper understanding of porous electrode preparation and performance losses is necessary to advance the anion exchange membrane fuel cell (AEMFC) technology. This study has investigated the performance losses at 50 °C for varied: Tokuyama AS-4 ionomer content in the catalyst layer, Pt/C loading and catalyst layer thickness at the anode and cathode, relative humidity, and anode catalyst. The prepared gas diffusion electrodes in the interval of ionomer-to-Pt/C weight ratio of 0.4–0.8 or 29–44 wt% ionomer content show the highest performance. Varying the loading and catalyst layer thickness simultaneously shows that both the cathode and the anode influence the cell performance. The effects of the two electrodes are shown to vary with current density and this is assumed to be due to non-uniform current distribution throughout the electrodes. Further, lowering the relative humidity at the anode and cathode separately shows small performance losses for both electrodes that could be related to lowered ionomer conductivity. Continued studies are needed to optimize, and understand limitations of, each of the two electrodes to obtain improved cell performance.
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| 23. |
- Carlson, Annika, et al.
(författare)
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Fuel cell evaluation of anion exchange membranes based on poly(phenylene oxide) with different cationic group placement
- 2020
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Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry. - 2398-4902. ; 4:5, s. 2274-2283
-
Tidskriftsartikel (refereegranskat)abstract
- Four novel poly(phenylene oxide)-based anion exchange membranes were investigated for electrochemical performance, ionic conductivity and water transport properties in an operating anion exchange membrane fuel cell (AEMFC), using Pt/C gas diffusion electrodes with Tokuyama ionomer. The poly(phenylene oxide)-membranes have a 1- or 5-carbon alkyl spacer between the backbone and a trimethylalkylammonium (TMA) or piperidinium (Pip) cationic group, and ion-exchange capacities (IECs) between 1.5 and 1.9 mequiv g(-1). The polymer with a 5-carbon alkyl spacer, a TMA cationic group, and a higher IEC showed the highest ion conductivity and performance in the AEMFC. The results also show that introducing a 5-carbon alkyl spacer does not improve performance unless the IEC is increased and that exchanging the TMA with a Pip cationic group results in lower fuel cell performance despite a higher IEC. A discrepancy in ion conductivity between fuel cell and ex situ test was observed for the 5-carbon spacer polymers and is attributed to a higher sensitivity for dehydration. Similar water flux under load, from the anode to the cathode with increased water content at both electrodes, was observed for all membranes and only varied with membrane thickness. The deviation in fuel cell performance observed between the membranes could not be explained by differences in water flux or ionic conduction, suggesting that the electrode-membrane interaction plays a major role. Nevertheless, the study emphasizes that high membrane conductivity (for the lambda-range in a fuel cell) and efficient water transport (obtained by lower membrane thickness) promote higher electrochemical performance.
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| 24. |
- Carlson, Annika, et al.
(författare)
-
Fuel cell evaluation of anion exchange membranes based on poly(phenylene oxide) with different cationic group placement
- 2020
-
Ingår i: Sustainable Energy & Fuels. - 2398-4902. ; 4:5, s. 2274-2283
-
Tidskriftsartikel (refereegranskat)abstract
- Four novel poly(phenylene oxide)-based anion exchange membranes were investigated for electrochemical performance, ionic conductivity and water transport properties in an operating anion exchange membrane fuel cell (AEMFC) , using Pt/C gas diffusion electrodes with Tokuyama ionomer. The poly(phenylene oxide)-membranes have a 1- or 5-carbon alkyl spacer between the backbone and a trimethylalkylammonium (TMA) or piperidinium (Pip) cationic group, and ion-exchange capacities (IECs) between 1.5 and 1.9 mequiv g-1. The polymer with a 5-carbon alkyl spacer, a TMA cationic group, and a higher IEC showed the highest ion conductivity and performance in the AEMFC. The results also show that introducing a 5-carbon alkyl spacer does not improve performance unless the IEC is increased and that exchanging the TMA with a Pip cationic group results in lower fuel cell performance despite a higher IEC. A discrepancy in ion conductivity between fuel cell and ex-situ test was observed for the 5-carbon spacer polymers and is attributed to a higher sensitivity for dehydration. Similar water flux under load, from the anode to the cathode with increased water content at both electrodes, was observed for all membranes and only varied with membrane thickness. The deviation in fuel cell performance observed between the membranes could not be explained by differences in water flux or ionic conduction, suggesting that the electrodes – membrane interaction plays a major role. Nevertheless, the study emphasizes that high membrane conductivity (for the λ-range in a fuel cell) and an efficient water transport (obtained by lower membrane thickness) promote higher electrochemical performance.
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| 25. |
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| 26. |
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| 27. |
- Chiche, Ariel
(författare)
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On Hybrid Fuel Cell and Battery Systems for Maritime Applications
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hydrogen is seen as a key player in leading to a sustainable energy sector and decarbonizing the transport sector. Proton Exchange Membrane Fuel Cells (PEMFCs) consume hydrogen and oxygen to generate water, heat and electricity. If designed properly, a hydrogen-fuelled system can significantly increase the endurance of vehicles without increasing the weight or volume of the energy system, which makes it a promising solution for maritime applications. To take advantage of the high density of energy in hydrogen and of power in batteries, a sizing strategy for hybrid systems was developed and implemented for an underwater vessel and a rescue boat, considering various constraints, e.g. neutral buoyancy for underwater vehicles. Several types of storage for reactants were compared and their thermal properties were included in the sizing strategy. To understand the behaviour of fuel cells in an underwater environment, i.e. a closed environment without presence of oxygen, an experimental lab-scale setup was built, and various hydrogen supply methods were tested. Finally, modelling of the hybrid system was used to compare different energy management strategies (EMSs). The developed sizing strategy, tested through real power profiles, demonstrates that an optimized hybrid system becomes more compact and lighter than a battery system when the length of the mission increases. Such a system can also compete in terms of weight and volume with a diesel engine and help reduce the environmental impact of a vehicle. The heat balance analysis shows that the fuel cell is the major heat contributor, regardless of the combination of reactants storage units. The experimental work highlights that the fuel cell should deliver a low current density at a high relative humidity in order to limit the waste of hydrogen and increase the performance of the stack. The symmetric purging strategy appears to increase the stability of the stack over time. It is also shown that it is crucial to select an adapted EMS for each mission in order to fulfil it. Some EMSs tend to limit the hydrogen consumption while others deplete more battery power. To conclude, it is relevant to use fuel cell systems for maritime applications, and has the potential to increase the length of the missions performed.
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| 28. |
- Crowston, Kevin, et al.
(författare)
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Introduction to genres in communication and digital documents minitrack
- 2008
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Ingår i: Proceedings of the Annual Hawaii International Conference on System Sciences. - Washington, DC : IEEE Computer Society. - 1530-1605.
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Tidskriftsartikel (refereegranskat)abstract
- Rhetoricians since Aristotle have attempted to classify communications into categories or "genres" with similar form, topic or purpose. Given a socially recognized need to communicate, individuals will typically express similar social motives, themes and topics in a communication with similar physical and linguistic characteristics, that is, they will communicate in a recognized genre.
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| 29. |
- de-Wahl Granelli, Anne, 1970, et al.
(författare)
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Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns.
- 2009
-
Ingår i: BMJ (Clinical research ed.). - 1468-5833. ; 338
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the use of pulse oximetry to screen for early detection of life threatening congenital heart disease. DESIGN: Prospective screening study with a new generation pulse oximeter before discharge from well baby nurseries in West Götaland. Cohort study comparing the detection rate of duct dependent circulation in West Götaland with that in other regions not using pulse oximetry screening. Deaths at home with undetected duct dependent circulation were included. SETTING: All 5 maternity units in West Götaland and the supraregional referral centre for neonatal cardiac surgery. PARTICIPANTS: 39,821 screened babies born between 1 July 2004 and 31 March 2007. Total duct dependent circulation cohorts: West Götaland n=60, other referring regions n=100. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values, and likelihood ratio for pulse oximetry screening and for neonatal physical examination alone. RESULTS: In West Götaland 29 babies in well baby nurseries had duct dependent circulation undetected before neonatal discharge examination. In 13 cases, pulse oximetry showed oxygen saturations
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| 30. |
- Ebbesson, Esbjörn, 1979-, et al.
(författare)
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A User Driven Design Approach to Creating UGC Services – Challenging the Newspaper Industry
- 2013
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Ingår i: Human Interface and the Management of Information Information and Interaction Design. - Berlin : Springer Berlin/Heidelberg. - 9783642392085 - 9783642392092 ; , s. 187-196
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Konferensbidrag (refereegranskat)abstract
- This paper presents a user driven approach to creating user generated content services together with newspaper representatives and researchers in a Living Lab setting. Two cases are discussed, one with creating city district blogs and one with creating a site for un-employed youth. In each case both situated and distributed design activities were conducted, and the paper discusses the challenges with this approach. As the newspaper industry traditionally designs their services in-house from their own ideas and thereafter tests them with their readers, a user driven approach by readers was very challenging. However, the newspaper representatives also found it rewarding to embrace their ideas. The participating readers were very active in the situated activities but only a few continued the same activity online. The paper concludes by proposing a model for how to view the changing role of a researcher or facilitator in these types of setting. © 2013 Springer-Verlag Berlin Heidelberg.
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| 31. |
- Ebbesson, Esbjörn, 1979-, et al.
(författare)
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Co-creating Innovative UGC Services with the Media Industry
- 2013
-
Ingår i: Proceedings of the Annual Hawaii International Conference on System Sciences. - Piscataway : IEEE Press. - 9781467359337 - 9781509056460 - 9780769548920 - 9781467359337 ; , s. 3057-3066
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Konferensbidrag (refereegranskat)abstract
- In this paper, we identify challenges of involving different stakeholders in distributed co-creative open innovation processes and discuss how these challenges can be handled. In the LoCoMedia project, researchers, newspaper representatives and readers/users have co-created innovative user generated content (UGC) services. With a Living Lab approach with the user in focus in a real life setting, we have experimented with different ways of involving different stakeholders in nine experimental UGC projects. The study concludes that careful recruitment, face to face meetings as a compliment to online activities, heterogeneous participant groups, feedback and careful selection of a flexible online platform is important aspects for involving different stakeholders in co-creating innovative processes. © 2012 IEEE.
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| 32. |
- Ehnman, Monika, et al.
(författare)
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Distinct Effects of Ligand-Induced PDGFR alpha and PDGFR beta Signaling in the Human Rhabdomyosarcoma Tumor Cell and Stroma Cell Compartments
- 2013
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Ingår i: Cancer Research. - 1538-7445. ; 73:7, s. 2139-2149
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor receptors (PDGFR) alpha and beta have been suggested as potential targets for treatment of rhabdomyosarcoma, the most common soft tissue sarcoma in children. This study identifies biologic activities linked to PDGF signaling in rhabdomyosarcoma models and human sample collections. Analysis of gene expression profiles of 101 primary human rhabdomyosarcomas revealed elevated PDGF-C and -D expression in all subtypes, with PDGF-D as the solely overexpressed PDGFR beta ligand. By immunohistochemistry, PDGF-CC, PDGF-DD, and PDGFR alpha were found in tumor cells, whereas PDGFR beta was primarily detected in vascular stroma. These results are concordant with the biologic processes and pathways identified by data mining. While PDGF-CC/PDGFR alpha signaling associated with genes involved in the reactivation of developmental programs, PDGF-DD/PDGFR beta signaling related to wound healing and leukocyte differentiation. Clinicopathologic correlations further identified associations between PDGFR beta in vascular stroma and the alveolar subtype and with presence of metastases. Functional validation of our findings was carried out in molecularly distinct model systems, where therapeutic targeting reduced tumor burden in a PDGFR-dependent manner with effects on cell proliferation, vessel density, and macrophage infiltration. The PDGFR-selective inhibitor CP-673,451 regulated cell proliferation through mechanisms involving reduced phosphorylation of GSK-3 alpha and GSK-3 beta. Additional tissue culture studies showed a PDGFR-dependent regulation of rhabdosphere formation/cancer cell stemness, differentiation, senescence, and apoptosis. In summary, the study shows a clinically relevant distinction in PDGF signaling in human rhabdomyosarcoma and also suggests continued exploration of the influence of stromal PDGFRs on sarcoma progression. Cancer Res; 73(7); 2139-49. (C)2013 AACR.
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| 33. |
- Eigmüller, P., et al.
(författare)
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K2-60b and K2-107b. A Sub-Jovian and a Jovian Planet from the K2 Mission
- 2017
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 1538-3881 .- 0004-6256. ; 153:3
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Tidskriftsartikel (refereegranskat)abstract
- We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 ± 0.037 R Jup and a mass of 0.426 ± 0.037 M Jup and orbits a G4 V star with an orbital period of 3.00267 ± 0.00006 days. K2-107b has a radius of 1.44 ± 0.15 R Jup and a mass of 0.84 ± 0.08 M Jup and orbits an F9 IV star every 3.31392 ± 0.00002 days. K2-60b is among the few planets at the edge of the so-called “desert” of short-period sub-Jovian planets. K2-107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence.
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| 34. |
- Eliason, Emma
(författare)
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Value awareness in web site design
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims to develop knowledge about value-awareness in website design. To achieve the aim - this thesis investigates values in thedesign of Swedish municipality web sites through a perspective ofinherited values. It covers the designer perspectives’ intentions andreasons as well as user experiences and expectations. Value awarenessis influenced by theories where values and the creation of meaning arefocused. E.g., theories about: Genres; Use quality; Value sensitivedesign. The design process is seen as a decision process, wherequestions about prioritization of values have been considered.The study yields four main contributions. 1) A reflective concept ofvalue awareness; 2) Knowledge about genre-related design effects byusing the perspective of inherited values; 3) A method for value awareweb design; and 4) A guide to design by example. The empirical studyis a contribution for practical web site design for municipalities.A conclusion made in the study is that the perspective of inheritedvalues contributes to reflections on website design in several differentways. The perspective makes it possible to detect effects of designdecisions and it supports the identification of different designexamples which can be used to discuss design priorities,communicated values, and design effects. This study has shown that itis important to be value aware in web site design. Inspiration fromother designs, leads to inheritance of value prioritizations. Elements ofthe design process, such as technical and organizational arrangementsconvey prioritizations made elsewhere at earlier stages. These factorscreate expectations and experiences that might not be appropriate inthe context in which the web site is intended.
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| 35. |
- Eriksson, Annika
(författare)
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Förutsättningar blir till erbjudanden : belyst genom utformning och genomförande av förskolans temainriktade arbetssätt
- 2014
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to develop knowledge on the influence of preschool working conditions, i.e. social and political factors and factors within the individual preschool, on offers afforded to children. To illustrate this influence, I chose to investigate the design and implementation of preschool theme work. The study examined preschool pedagogues’ motives, organisation, contents and methods that underlie their teaching in the theme work and the influence of working conditions in this process. Ethnographic methods have been applied, including observations and interviews with preschool pedagogues in four preschool settings. The study had a theoretical starting point in curriculum theory, with Bernstein’s concept of classification and framing as well as frame factor theory used as tools in analysing the material. The results show that a combination of various working conditions affects offers afforded to preschool children in theme work. The pedagogues make decisions that underlie their teaching partly in relations to social and political changes and reforms, and partly in relation to processes formed historically. The children are offered an organisation, contents and methods in the theme work that arise from pedagogues’ understanding of their mission, curriculum and the childrens’ interests and needs.
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| 36. |
- Eriksson, Anna, et al.
(författare)
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Identification of AKN-032, a novel 2-aminopyrazine tyrosine kinase inhibitor, with significant preclinical activity in acute myeloid leukemia
- 2010
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Ingår i: Biochemical Pharmacology. - : Elsevier BV. - 0006-2952 .- 1356-1839. ; 80:10, s. 1507-1516
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Tidskriftsartikel (refereegranskat)abstract
- Aberrant signal transduction by mutant or overexpressed protein kinases has emerged as a promising target for treatment of acute myeloid leukemia (AML). We here present a novel low molecular weight kinase inhibitor, AKN-032, targeting the FMS-like tyrosine kinase 3 (FLT3) and discovered in a new type of screening funnel combining the target therapy approach with sequential cellular screens. AKN-032 was identified among 150 selected hits from three different high throughput kinase screens. Further characterization showed inhibitory activity on FLT3 enzyme with an IC50 of 70 nM. Western blot analysis revealed reduced autophosphorylation of the FLT3-receptor in AML cell line MV4-11 cells after exposure to AKN-032. Flow cytometry disclosed cytotoxic activity against MV4-11, but not against non-malignant 3T3-L1 fibroblast cells. Using a fluorometric microculture cytotoxicity assay, AKN-032 was tested against 15 cell lines and displayed a potent cytotoxic activity in AML cell lines MV4-11 (IC50 = 0.4 mu M) and Kasumi-1 (IC50 = 2.3 mu M). AKN-032 was also highly cytotoxic in tumor cells from AML patients in vitro. Furthermore, AKN-032 demonstrated significant antileukemic effect in a relatively resistant in vivo hollow fiber mouse model. No major toxicity was observed in the animals. In conclusion. AKN-032 is a promising new kinase inhibitor with significant in vivo and in vitro activity in AML Results from the hollow fiber mouse assay suggest a favorable toxicity profile. Future studies will focus on pharmacokinetic properties, toxicity as well as further clarifying the mechanisms of action of AKN-032 in AML.
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| 37. |
- Eriksson, Björn, et al.
(författare)
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Degradation and lifetime evaluation of Fe-N-C based catalyst in PEMFC
- 2015
-
Ingår i: Proceedings of the 6th European Fuel Cell - Piero Lunghi Conference, EFC 2015. - : ENEA. - 9788882863241 ; , s. 223-224
-
Konferensbidrag (refereegranskat)abstract
- The restricted lifetime of Fe-N-C based catalysts is often assumed to be connected to the operating temperature. This study will investigate how the cell performance, electrode structure and composition vary over time, at different cell temperatures. At lower temperature, one may expect an increase in radical's stability, but a decrease in reactivity. Results show that the electrode degenerates over time, and that the electrochemical performance decay is similar for 40, 60, and 80° C. However, the loss of active sites is higher at higher temperature. This suggests that indirect production of radicals via H2O2 production during ORR is higher at higher temperatures and is a key degradation mechanism for this Fe-N-C catalyst.
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| 38. |
- Eriksson, Björn
(författare)
-
Electrochemical evaluation of new materials in polymer electrolyte fuel cells
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Polymer electrolyte fuel cells (PEFC) convert the chemical energy in hydrogen to electrical energy and heat, with the only exhaust being water. Fuel cells are considered key in achieving a sustainable energy sector. The main obstacles to wide scale commercialization are cost and durability. The aim of this thesis is to evaluate new materials for PEFC to potentially lower cost and increase durability. To lower the amount of expensive platinum catalyst in the fuel cell, the activities of Pt-rare earth metal (REM) alloy catalysts have been tested. To improve the lifetime of the carbon support, the carbon corrosion properties of multi walled carbon nanotubes have been evaluated. To reduce the overall cost of fuel cell stacks, carbon coated and metal coated bipolar plates have been tested. To increase the performance and lifetime of anion exchange membranes, the water transport has been studied.The results show that the Pt-REM catalysts had at least two times higher specific activity than pure platinum, and even higher activities should be obtainable if the surface structures are further refined.Multi-walled carbon nanotubes had lower carbon corrosion than conventional carbon Vulcan XC-72. However, once severely corroded their porous structure collapsed, causing major performance losses.The carbon coated metallic bipolar plates showed no significant increase of internal contact resistance (ICR) by cycling, suggesting that these coatings are stable in fuel cells. The NiMo- and NiMoP coated bipolar plates showed low ICR, however, presence of the coated bipolar plates caused secondary harmful effects on the polymer membrane and ionomer.Considering the water transport through anion exchange membranes it was found that most membranes showed very similar water transport properties, with more water detected at both the anode and cathode when a current was applied. The most significant factor governing the water transport properties was the membrane thickness, with thicker membranes reducing the backflow of water from anode to cathode.The results indicate that all of the new tested materials have the capability to improve the lifetime and reduce cost and thereby improve the overall performance of PEFC.
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| 39. |
- Eriksson, Björn, et al.
(författare)
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Enhanced oxygen reduction activity with rare earth metal alloy catalysts in proton exchange membrane fuel cells
- 2021
-
Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 387
-
Tidskriftsartikel (refereegranskat)abstract
- Alloying platinum is an approach to increase the oxygen reduction reaction (ORR) activity and at the same time reduce the amount of precious platinum catalyst in proton exchange membrane fuel cells (PEMFC). In this work the cathode activity of thin films of rare earth metals (REM) alloys, Pt Y, Pt Gd and Pt Tb, produced by sputter deposition onto gas diffusion layers, are evaluated in a fuel cell by means of polarization curves in O /H , and cyclic- and CO-stripping voltammetry in N /5% H . Prior to evaluation, the model electrodes were acid-treated to obtain a Pt skin covering the PtREM alloy bulk, as was revealed by energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The core shell alloys of Pt Y and Pt Gd catalysts show a specific activity enhancement at 0.9 V of 2.5 times compared to pure Pt. The slightly lower enhancement factor of 2.0 for Pt Tb is concluded to be due to leaching of the REM, that resulted in a thicker, and subsequently less strained, Pt overlayer. The high activity, combined with the minor changes in surface composition, achieved in the fuel cell environment shows that PtREM core shell catalysts are promising for the cathode reaction in PEMFC.
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| 40. |
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| 41. |
- Eriksson, Björn, et al.
(författare)
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Quantifying water transport in anion exchange membrane fuel cells
- 2019
-
Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 44:10, s. 4930-4939
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Tidskriftsartikel (refereegranskat)abstract
- Sufficient water transport through the membrane is necessary for a well-performing anion exchange membrane fuel cell (AEMFC). In this study, the water flux through a membrane electrode assembly (MEA), using a Tokuyama A201 membrane, is quantified using humidity sensors at the in- and outlet on both sides of the MEA. Experiments performed in humidified inert gas at both sides of the MEA or with liquid water at one side shows that the aggregation state of water has a large impact on the transport properties. The water fluxes are shown to be approximately three times larger for a membrane in contact with liquid water compared to vaporous. Further, the flux during fuel cell operation is investigated and shows that the transport rate of water in the membrane is affected by an applied current. The water vapor content increases on both the anode and cathode side of the AEMFC for all investigated current densities. Through modeling, an apparent water drag coefficient is determined to −0.64, indicating that the current-induced transport of water occurs in the opposite direction to the transport of hydroxide ions. These results implicate that flooding, on one or both electrodes, is a larger concern than dry-out in an AEMFC.
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| 42. |
- Eriksson, Björn, et al.
(författare)
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Shut-down cycles as accelerated degradation tests of metallic bipolar plates in proton exchange membrane fuel cells
- 2017
-
Ingår i: EFC 2017 - Proceedings of the 7th European Fuel Cell Piero Lunghi Conference. - : ENEA. ; , s. 169-170
-
Konferensbidrag (refereegranskat)abstract
- The lifetime of coated stainless steel bipolar plates (BPPs) is investigated using shutdown strategies as an accelerated degradation test (ADT). The effect of 1550 shutdowns is evaluated from contact resistance measurements and from cyclic voltammetry. The results show that the bipolar plate is not affected by the ADT, however, the membrane electrode assembly (MEA) is adversely affected. The cathode catalyst layer is severely reduced during the cycling, causing performance loss. The results show that air purge shutdown cycling for 1550 cycles is not an effective ADT for BPP.
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| 43. |
- Eriksson Bergström, Sofia, 1974-, et al.
(författare)
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Design för lärande i Särskolan
- 2021
-
Ingår i: Praktiknära pedagogisk forskning i det lärande nordiska nätverket Gemensamma Vägar. - Umeå : Universitetet. - 9789178555611 ; , s. 48-63
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Bokkapitel (refereegranskat)
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| 44. |
- Eriksson, Carina, et al.
(författare)
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Antifeedants and feeding stimulants in bark extracts of ten woody non-host species of the pine weevil, Hylobius abietis
- 2008
-
Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 34:10, s. 1290-1297
-
Tidskriftsartikel (refereegranskat)abstract
- Bark of ten woody species, known to be rejected as a food source by the pine weevil, Hylobius abietis, were sequentially extracted by a Soxhlet apparatus with pentane followed by methanol. Species were alder (Alnus glutinosa), aspen (Populus tremula), beech (Fagus sylvatica), guelder rose (Viburnum opulus), holly (Ilex aquifolium), horse chestnut (Aesculus hippocastanum), lilac (Syringa vulgaris), spindle tree (Evonymus europaeus), walnut (Juglans regia), and yew (Taxus baccata). Bark of each species was collected in southern Scandinavia during the summer. Resulting extracts were tested for antifeedant activity against the pine weevil by a micro-feeding choice assay. At a dose corresponding to that in the bark, methanol extracts from Aesculus, Taxus, Ilex, and Populus were antifeedant active, while pentane extracts of Aesculus, Fagus, Syringa, and Viburnum were stimulatory. Four known antifeedants against H. abietis, the straight-chained carboxylic acids, hexanoic and nonanoic acid (C6 and C9), carvone, and carvacrol were identified by gas chromatography (GC)-mass spectrometry (MS) in several extracts. The major constituents were identified and tested for feeding deterrence. The aromatic compounds benzyl alcohol and 2-phenylethanol are new non-host plant-derived feeding deterrents for the pine weevil. Additionally, two feeding stimulants, beta-sitosterol and 5-(hydroxymethyl)-2-furaldehyde, were identified. One active methanol extract of Aesculus bark was sequentially fractionated by liquid chromatography, and major compounds were tentatively identified as branched alcohols and esters of hexanoic acid. Five commercially available hexanoate esters and two commercially available branched alcohols were identified as new active antifeedants. Both stimulatory and inhibiting compounds were found in the same extracts and co-eluted in the same or adjacent fractions. The mix of semiochemicals of opposite activity in each extract or fraction could explain the stimulatory-, inhibitory-, or sometimes neutral activity. Generally, such co-occurrence confounds the isolation of antifeedants.
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| 45. |
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| 46. |
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| 47. |
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| 48. |
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| 49. |
- Eriksson, Carina, 1973-
(författare)
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Isolation, Synthesis and Structure-Activity Relationships of Antifeedants against the Pine Weevil, Hylobius Abietis
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The large pine weevil, Hylobius abietis L., is a major insect pest on conifer seedlings in northern Europe. Due to its feeding newly planted trees get girdled, resulting in high seedling mortality (up to 80%). As a consequence great financial losses to the forest industry occur. Today the seedlings are protected with the pyrethroid insecticide cypermethrin. This insecticide is toxic to aquatic organisms and is, from 2010, prohibited for use in Sweden by the Swedish Chemicals Inspectorate. An alternative to insecticides is to protect the seedlings with antifeedants, compounds that, either through taste or smell or both, deter the weevils from feeding. This thesis describes the search for and the synthesis of such antifeedant compounds. Bark extracts of several woody species, known to be non-palatable to the weevil, were prepared and found to display antifeedant activity against H. abietis. The major chemical constituents of the extracts were tested for antifeedant activity. Antifeedants such as eugenol, 2-phenylethanol and benzylalcohol, but also feeding stimulants such as β-sitosterol and linoleic acid, were identified. An extract of linden bark, Tilia cordata, was shown to contain nonanoic acid, a highly active antifeedant. Other aliphatic carboxylic acids were also found to display high antifeedant activities against the weevil, both in laboratory and in field tests. The enantiomers of dihydropinidine, a piperidine alkaloid present in several conifer species, were prepared by dimethylzinc mediated allylation of 2- methyltetrahydropyridine-N-oxide. When tested in micro feeding assays, no difference in antifeedant activity was found for the enantiomers. In a field test high antifeedant activity, comparable with that of the presently used insecticide cypermethrin, was found for (±)-dihydropindine. Other naturally occurring piperidine alkaloids were synthesised and also found to display high antifeedant activities in laboratory tests. Structure-activity relationships were evaluated for methoxy substituted benzaldehydes, benzoic acids and cinnamic aldehydes, -acids, -esters and -alcohols. While the carboxylic acids were inactive or even feeding stimulants, the aldehydes were the most active antifeedants
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| 50. |
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