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  • Public defence: 2017-03-08 13:15 9C203, Karlstad
    Sjöstrand, Björn
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Dewatering aspects at the forming section of the paper machine: Rewetting and forming fabric structure2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The underlying motives of the research undertaken here are twofold: to obtain a deeper understanding of the dewatering mechanisms at the forming section of a papermaking machine and to develop numerical models that describe the flow through forming fabrics. More comprehensive knowledge of dewatering in the forming section allows suggestions to be made for improvements that reduce the amount of energy used in the process without affecting the quality of the end product.

     

    The objective of this thesis is to answer the following questions:

    • How and why does rewetting occur at the high vacuum suction boxes?
    • How does the structure of the forming fabric affect dewatering at the forming section?
    • Is it possible to create accurate numerical models for forming fabrics, and can these be used to predict the dewatering behaviour of new types of fabrics?

     

    Laboratory and pilot studies simulating high vacuum suction boxes were performed together with numerical modelling of the flow of air and water through both the forming fabric and the paper sheet.

     

    The conclusion drawn from the pilot study is that rewetting significantly lowers the dryness of the paper sheet exiting the suction boxes. The phenomenon is extremely rapid and is most likely driven by capillary forces. The high speed at which this rewetting occurs makes it difficult to impede by placing the suction boxes closer to the couch pick-up: the solution is more likely to be the use of new and improved designs of the forming fabric. The structure of the forming fabric has been shown to affect the dewatering rate at certain conditions of vacuum dewatering, and can possibly be connected partly to the fact that fibres penetrate the surface of the fabric to varying degrees and partly to the flow resistance of the different fabric structures. Numerical models of high accuracy can be constructed and used to predetermine how new fabric designs would affect dewatering at the forming section.

     

    This thesis quantifies aspects of dewatering such as rewetting and the influence of the forming fabric. Understanding these dewatering aspects further provides for the potential enhancement of energy efficiency in the forming section, and thereby the entire papermaking process. The forming fabric can play an important role in improving energy efficiency: rewetting after the high vacuum suction boxes occurs more rapidly than was previously known, so its design might be the only possible way of impeding it. The forming fabric can also improve the rate of dewatering: it is therefore likely that its design will be important in the next stage of developing energy efficiency and thereby play a part in achieving a more sustainable future.

  • Duek, Susanne
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Educational Studies.
    Med andra ord: Samspel och villkor för litteracitet bland nyanlända barn2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This doctoral thesis centres on six children, aged four to nine, who relatively recently immigrated to Sweden. The children’s encounters with literacy are in focus. These children are not only new arrivals to Sweden, they also have in common that Swedish is their second language and that their parents have had little or no formal education prior to arriving in Sweden. The study draws on sociocultural approaches to literacy, and more specifically the field of New Literacy Studies. In this study, reading and writing are viewed as social practices comprising different related sociocultural aspects such as norms, values, habits, traditions and ideologies, and the study concentrates on social and ideological perspectives on literacy. Bourdieu’s notions of habitus and symbolic capital have also been used for the analysis.

    The empirical material was collected through an ethnographic approach. Each child was followed for one year, particularly at school/preschool. The children’s homes were also visited, and their parents and teachers were interviewed. Observations involved different degrees of participation and were documented through field notes and photographs. The interviews were audio-recorded and transcribed. In addition, artefacts and school material from the field were collected or photographed. A qualitative content analysis of the collected data was performed.

    The analysis show that sociocultural incongruence, coupled with flawed communication between the schools and the homes, caused the children less continuity between school and home practices. Though, the results also show, that the children studied to a considerable extent adapted to the monolingual, homogenous norms when they participated in school practices. These children are therefore highly adaptable, while their teachers found it much harder to handle or even be aware of sociocultural incongruences.

  • Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Eulerian vs. Lagrangian analyses of pedestrian dynamics asymmetries in a staircase landing2017In: Collective Dynamics, ISSN 2366-8539Article in journal (Refereed)
  • Schneider, Lea Dominique
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences.
    Conservation ecology of the thick-shelled river mussel Unio crassus : The importance of parasite-host interactions2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Unionoid mussels are globally threatened and their conservation requires species-specific knowledge on their ecology and parasite-host interaction. Unio crassus is one of Europe’s most threatened unionoid species and has a temporary obligate parasitic life stage (glochidia) on fish. A lack of suitable hosts is probably a major limitation for mussel recruitment, but host species composition, suitability and availability in time and space have yet to be fully explored. This thesis examines different aspects of the host fish species, including their composition, suitability and ecological importance, in relation to U. crassus, using both field and laboratory studies. The effects of mussel and host density on mussel reproductive potential were considered, as were aspects of evolutionary adaptations between mussels and fish and how climate change may affect their interaction.

    The results show that U. crassus is a host generalist, parasitizing a variety of fish species. Host suitability and density, which varied among fish species and rivers, affected the level of glochidia encapsulation, hence mussel reproductive potential, more so than the density of mussels taking part in reproduction. Ecologically important hosts included both highly suitable primary hosts, and less suitable hosts that were highly abundant. Whether or not U. crassus has specific adaptations to its hosts to enhance juvenile transformation remains unclear. No distinct pattern of local adaptation was found, nor was there an effect of host fish presence on the timing of glochidia release by adult mussels. Instead, temperature played a major role, with results suggesting that changes in spring water temperature regimes can cause temporal and spatial mismatches in the mussel-host interaction. This thesis indicates that investigations of local mussel-host interactions help in identifying mechanisms important for unionoid conservation management and prioritization.

  • Hilander, Markus
    University of Helsinki.
    Reading the geographical content of media images as part of young people’s geo-media skills2016In: Nordidactica: Journal of Humanities and Social Science Education, ISSN 2000-9879, no 2016:2, 69-92 p.Article in journal (Refereed)
    Abstract [en]

    As a new set of skills, geo-media tools and resources are being introduced in the Finnish comprehensive school curriculum, although an explicit definition of ‘geo-media’ is not given. In the Finnish upper secondary school curriculum, geo-media is described with one sentence. In this article, the concept of geo-media is approached with online questionnaires introduced to Finnish and international experts on geography education and geo-media (n=6) and Finnish geography teachers (n=22). Both groups tend to perceive geo-media as digital sources used in geography education. Yet, teachers think that geo-media will not change their teaching practices. In the literature, geo-media refer to all media that carry georeferenced information. Therefore, this paper introduces three visions of how geo-media can be understood as a broader concept; that is, geographical media literacy skills. The first example is (1) a photograph of ‘Reverend Billy’ with which the value of geolocative information is studied with the semiotic procedure of a ‘commutation test.’ The second example is (2) an advertisement by Diesel, in which geographical stereotypes are questioned with a semiotic process of the ‘transfer of meanings.’ The third example, (3) a Finnish cartoon strip ‘Viivi & Wagner,’ highlights the role of global events when reading images from a geographical perspective. Although location plays a crucial role in all three of the examples, the experts and the teachers did not pay that much attention to the question of ‘where.’ In consequence, young people need to be competent in interpreting and evaluating the geographical content of visual re-presentations before producing geo-media presentations of their own.

  • Eliasson, Per
    et al.
    Malmö högskola.
    Nordgren, Kenneth
    Karlstad University.
    Vilka är förutsättningarna i svensk grundskola för en interkulturell historieundervisning?2016In: Nordidactica: Journal of Humanities and Social Science Education, ISSN 2000-9879, no 2016:2, 47-68 p.Article in journal (Refereed)
    Abstract [en]

    This is the first major quantitative study of how teachers at the compulsory school look at the subject of History and its conditions. The article focuses on elements of the survey related to the content of teaching and how teachers perceive the conditions for the intercultural mission of the subject. The historical content in the form of selected time periods and geographic focus forms a clear canon: in grades 1–3 local history and Swedish history, in 4–6 Swedish and Nordic history, and in 7–9 Western European history with global, but mainly Eurocentric, outlooks. In terms of students’ skills to interpret history they encounter the result is to some extent contradictory. Empathy and critical thinking are highly valued but the actual work to develop these abilities is of lesser importance. Instead, storytelling is stressed as the major form of education. Teachers in grades 7–9 emphasize that long lines of development are important in their teaching. History’s orienting function leans more to the future and contemporary perspectives in grades 7–9, while students’ perspective on their own historical background ranked highest in 1–3 and 4–6. Future and contemporary issues are highlighted as a pattern in which racism and xenophobia become more important in higher grades while environmental issues decrease in importance. Multiculturalism and diversity issues occupy an intermediate position in this context but are perceived as important by teachers on all levels. An overall conclusion is that in the tension that exists between the traditions of the subject and an external pressure for change teachers need support to deal with the intercultural perspective.

  • Dessingué, Alexandre
    University of Stavanger.
    Dynamisk kulturarv, kritisk literacy og (fler)kulturforståelse i norsk grunnskole?2016In: Nordidactica: Journal of Humanities and Social Science Education, ISSN 2000-9879, no 2016:2, 22-46 p.Article in journal (Refereed)
    Abstract [en]

    In 2010 and 2011 several political leaders in Europe took distance from the multicultural society model. The concept of cultural heritage has been central to this political debate. But this concept is also central in education and actively used both in the general part of the curriculum in Norway and also in the curricula of several subjects. This article examines how «cultural heritage» is defined and used in three central curricula: Norwegian, Religious Studies and Ethics (KRLE), and Social Sciences, at a macro level (subject’s purpose) and also at a micro level (learning outcomes). To analyze how this concept is used in these curricula is an important premise for being able to think critically about this concept within the classroom. It also creates a better prerequisite for understanding the extent to which these subjects are focusing on a more or less dynamic and inclusive understanding of identity, as well as a self-reflexive and critical skills development

  • Vestøl, Jon Magne
    Department of Teacher Education and School Research, University of Oslo.
    On teaching what cannot be said: Reflections on the role of the unsayable in religious education2016In: Nordidactica: Journal of Humanities and Social Science Education, ISSN 2000-9879, no 2016:2, 1-21 p.Article in journal (Refereed)
    Abstract [en]

    This paper discusses how religious education can address the aspects of religion that transcend the limits of verbal communication. It draws on empirical data from group interviews with young Norwegian members of the Catholic and Lutheran Churches. The young informants reflect on aspects of religion that seem to exceed the limits of language and suggest that how religious education deals with these elements needs to be improved if it is to promote respect and understanding for religion and believers. Excerpts from the material are discussed in the light of theological and philosophical perspectives on the unsayable. Finally, possible pedagogical approaches to facilitate the understanding of and dealing with the handling of non-verbal aspects of religious faith are explored, including the use of philosophical perspectives, experiences from art and music and empirical descriptions of religious experience.

  • Löfström, Jan
    et al.
    University of Helsinki.
    Tani, Sirpa
    University of Helsinki.
    Editorial Nordidactica 2016:2: Does the future of subject didactics look darker than its past?2016In: Nordidactica: Journal of Humanities and Social Science Education, ISSN 2000-9879, no 2016:2, i-iii p.Article in journal (Other academic)
  • Olsson, Lars E
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center.
    Gärling, Tommy
    Department of Psychology, University of Gothenburg, Gothenburg, Sweden.
    Ettema, Dick
    Department of Human Geography and Planning, Utrecht University, Utrecht, Netherlands.
    Friman, Margareta
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center.
    Ståhl, Michael
    Current Mood vs. Recalled Impacts of Current Moods after Exposures to Sequences of Uncertain Monetary Outcomes2017In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 8, no 66Article in journal (Refereed)
    Abstract [en]

    Events in a sequence may each be evaluated as good or bad. We propose that such good-bad evaluations evoke emotional responses that change current mood. A model of recurrent updating of current mood is developed and compared to a model of how a sequence of events evoking emotional responses is evaluated retrospectively. In Experiment 1, 149 undergraduates are presented sequences of lottery outcomes with a fixed probability of losing or winning different amounts of money. Ratings of current mood are made after the sequence. Retrospective evaluations are either made after the ratings of current mood or, in a control condition, when no ratings of current mood are made. The results show an expected effect on current mood of the valence of the end of the sequence. The results are less clear in showing an expected beginning effect on the retrospective evaluations. An expected beginning effect on retrospective evaluations is found in Experiment 2 in which 41 undergraduates are first asked to remember the different amounts of money, then to evaluate the sequence as lottery outcomes.