lnu.sePublications
Change search
Refine search result
1 - 33 of 33
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Shevtsov, Stepan
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM). KU Leuven, Belgium.
    A Control-theoretic Approach to Realize Self-adaptive Software Systems with Guarantees2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Engineering modern software systems is a challenging task as these systems are subject to different types of uncertainties. Examples of such uncertainties are disturbances in the environment that are difficult to predict and goals that may change during operation. The idea of self-adaptation is to handle these uncertainties at runtime, when the knowledge becomes available to resolve them. As more software systems with strict requirements are designed to be self-adaptive, the need for adaptation guarantees is becoming a high-priority concern. Providing such guarantees with traditional architecture-based approaches has shown to be challenging, calling for new approaches to engineer self-adaptive systems. To tackle this challenge, this thesis studies control-based software adaptation (CBSA). CBSA applies principles from control theory to design self-adaptive software systems. More specifically, we address the following research problem using CBSA: how to realize self-adaptive software systems that satisfy multiple stakeholder requirements with guarantees in the presence of uncertainties.

    The thesis addresses the research problem in two subsequent stages. The first stage focuses on satisfying multiple stakeholder requirements of different types, and providing adaptation guarantees. This stage starts with a systematic literature review of CBSA, which provides a comprehensive overview of the field, including existing CBSA approaches, applied models and controllers, and analyzed guarantees. From the review, we identify a number of gaps in the existing research and concrete challenges in addressing the research problem. Then, we devise SimCA, a control-theoretic approach to realize self-adaptive software systems that satisfy multiple requirements with guarantees. SimCA combines mathematical models of software system, a control-based adaptation mechanism, and formal analysis of the required guarantees. SimCA is also reusable, meaning that it can be applied to a family of cooperative software systems with strict requirements. The second research stage focuses on handling different types of uncertainty.We first discuss the types of uncertainty and study whether existing CBSA approaches try to deal with these types. We then introduce an enhanced approach called SimCA* that includes components to deal with uncertainty in software parameters, addition or removal of requirements at runtime and software component interactions. In order to obtain evidence about the applicability and reusability of SimCA and SimCA*, we apply informal exploratory case studies with three software systems with strict requirements from different domains.

  • 2.
    Jalilzadehazhari, Elaheh
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    A decision-making framework for enhancing client well-being: When designing windows and blinds2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The current state of window and blind design moves beyond evaluating a single function, such as energy consumption, to include a human perspective in architectural design approach to create value. A current thought among architects and design professionals is that the highest value outcomes can be obtained when any architectural design contributes to enhanced well-being. Previous studies show that an individual’s well-being is determined by five main life domain factors: health, economy, personality, demographic variables and behavior variables. However, the life domain factors health and economy show stronger and more positive correlations to well-being. At this point, value creation within architectural design context, including window and blind design, can be seen as an attempt to enhance well-being by improving health and providing economic benefits for clients. Clients can represent i) owners who own a built asset, ii) investors who commit capital and expect to obtain financial return, or iii) occupants who live or work in the building every day. In the context of owner-occupied buildings, the value creation process is mainly seen as an attempt to enhance well-being for one entity by improving health and providing economic benefits. When considering investment properties or assets held for sale, the value creation process is mainly translated into an attempt to enhance well-being for several entities by improving health for occupants and providing economic benefits for owners and/or investors.Selecting a window and blind design to enhance client well-being remains a challenging task due to three main difficulties. The first difficulty relates to the contradictory effects of windows and blinds on visual and thermal comfort, energy consumption and life cycle cost. The second difficulty is the availability of a variety of window and blind designs in different sizes, positions and forms, making the selection of windows and blinds an intricate decision challenge for architects and designers. The third difficulty involves decisions about the selection of windows and blinds that should include all criteria and their interactions simultaneously.To resolve the abovementioned difficulties, this research applied the analytical hierarchy process (AHP) as a multi-criteria decision-making method to select a window and blind design based on a trade-off between visual comfort, thermal comfort, energy consumption and life cycle cost. The analyses of results show the capability of AHP in resolving difficulties, however its application is mainly limited to a small number of designs. To overcome this limitation, a decision-making framework was developed based on integration between non-dominated sorting genetic algorithm-II (NSGA-II) as an optimization algorithm and AHP. The strength and limitations of the decision-making framework were later tested by employing it in window and blind design practice. To investigate further benefits from the implementation of the framework, it was expanded by evaluating additional building envelopes, i.e. windows as well as external walls, roof and floor constructions, which made it possible to select a trade-off construction solution. The analyses of results show the framework’s ability to resolve difficulties and locate a trade-off design in a relatively short period of time. However, the decision-making framework only allows the analysis of the objective criteria for evaluating visual comfort, thermal comfort, energy consumption and life cycle cost. This is because it is necessary to rely on the creativity of the architects and designers when designing windows and blinds in order to consider subjective issues. The decision-making framework can be used either by design teams or customer service experts in window manufacturing companies. A literature study was therefore conducted to extend the technology acceptance model and thereby investigate the determinants of framework user acceptance of the decision-making framework. The results showed that organizational, individual, technological and environmental characteristics were the most influential external variables when investigating determinants of framework user acceptance of the framework. Organizational characteristics included top management support, training, organizational culture, and organizational size, while individual characteristics included the users’ previous knowledge and experience. Technological characteristics embraced information quality and system quality, meanwhile environmental characteristics comprised fulfillment of regulations and competitiveness.

  • 3.
    Rahman, Mohammad A.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Biophysical studies of the actin-myosin motor system and applications in nanoscience2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The actin-myosin motor system plays important roles in cellular processes. In addition, actin and myosin have been used for developments towards nanotechnological applications in recent years. Therefore, fundamental biophysical studies of actin and myosin and the actomyosin force generating cycle are important both in biology and for nanotechnology where the latter applications require methodological insights for optimization. This dual goal is central in the present thesis with major focus on factors that control the function (e.g. velocity) and the effectiveness of transport of filaments (e.g. filament flexural rigidity) through nanoscale channels with supplementation of methodological insights. The thesis thus provides evidence that actin is a dynamic filament whose flexural rigidity is different at different MgATP concentrations as well as in the presence or absence of myosin binding. Furthermore, probing the myosin ATPase cycle with the myosin inhibitor blebbistatin revealed that velocity is easily modified by this drug. Our detailed studies also suggest that actin-myosin force generation is preceded by Pi release and that blebbistatin changes the rate limiting transition in the cycle from the attachment step to a step between weakly attached states. The studies of actin dynamics and of the actomyosin force generating cycle were largely performed using in vitro motility assay (IVMA) where surface adsorbed myosin motor or its proteolytic fragments propel fluorescently labeled actin filaments. The IVMA is often taken as the basis for developments towards different nanotechnological applications. However, in the IVMA, actomyosin motility is often negatively affected by the presence of “dead”, non-functional myosin heads. Therefore, in this thesis, two popular methods, that are often used to remove dead myosin heads, are analyzed and compared. It was found that after affinity purification, the in vitro actin sliding velocity is reduced compared to the control conditions, something that was not seen with the use of blocking actin. Therefore, the effects of the affinity purification method should be considered when interpreting IVMA data. This is important while using IVMA both for fundamental studies and for nanotechnological applications. Another issue in the use of IVMAs in nanotechnological applications is the requirement for expensive and time-consuming fabrication of nanostructured devices. We therefore developed a suitable method for regenerating molecular motor based bionanodevices without a need to disassemble the flow cell. Evidence is presented that, use of proteinase K with a suitable detergent (SDS or Triton X100) lead to successful regeneration of devices where both actin-myosin and microtubule-kinesin motility are used. Lastly, this thesis presents efforts to immobilize engineered light sensitive myosin motors on trimethyl chlorosilane (TMCS) derivatized surfaces for light operated switching of myosin motor in order to control actin movement in nano-networks. This has potential for developing a programmable junction in a biocomputation network. In brief, the described results have contributed both to the fundamental understanding of actin and myosin properties and the actomyosin interaction mechanisms. They have also given technical insights for molecular motor based bionanotechnology.

  • 4.
    Sjökvist, Tinh
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Coated Norway Spruce: Influence of Wood Characteristics on Water Sorption and Coating Durability2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wood used outdoors is often degraded and discoloured by microorganisms as a natural part of its life cycle, particularly when exposed to high levels of moisture for prolonged times. In this case, the application of a coating (i.e. paint) is an option for increasing the service life of the wood.

    Norway spruce (Picea abies (L.) Karst.) is commonly used for outdoor applications in Sweden. Earlier studies have shown that uncoated spruce heartwood is less prone to moisture sorption in outdoor exposure, resulting in lower moisture content (MC) levels, as compared to sapwood. However, studies related to the above mentioned characteristics are rather limited for coated spruce, especially including the influence of outdoor exposure (i.e. weathering).

    The aim of this thesis is, therefore, to increase the knowledge of how heartwood and sapwood of different densities influence on the durability of coated Norway spruce for outdoor use. Different types of coatings with alkyd-, acrylic-, flour- (calcimine paint), or linseed-oil-based resin were included. The objectives were to study the water sorption (including MC variation) behaviour and crack formation of uncoated and coated heartwood and sapwood of different densities.

    Furthermore was an objective to study the microbial growth on the surface of similar samples of coated spruce in outdoor exposure. The used methods included wetting and liquid permeability experiments, accelerated water absorption (with samples floating freely in water), and outdoor field test. The field method lasted between three to five years and involved monitoring of the MC variation, the crack formation and the microbial growth on the samples.

    The results based on wetting measurements using octane as the adsorbed liquid showed no difference in liquid permeability between the spruce heartwood and sapwood samples of comparable densities, and indicated a similar level of pit aspiration (closure). The common flow path between two cells of conifers occurs through the pits. Still, the sapwood samples had in general a clearly higher water sorption rate than heartwood samples. It could be concluded that the increased sorption was presumably caused by a lowered water surface tension, most likely by a contamination effect of the water by surface-active sapwood extractives rather than differences in morphology of heartwood and sapwood.

    However, no clear difference in water absorption and MC levels was seen between coated heartwood and sapwood in the field study or in the accelerated water absorption study. Thus, it is suggested that a coating hinders the surfaceactive extractives to lower the water surface tension, resulting in a similar water absorption behaviour of coated heartwood and sapwood. The influence of density on water sorption of coated spruce was similarly to uncoated spruce, meaning the low-density samples had a higher MC than the high-density samples in the field tests. Furthermore, a one-year weathering of the coated and uncoated samples caused a larger increase in water sorption of high-density heartwood in the accelerated water absorption study.

    The field study on uncoated and calcimine-coated spruce showed a higher number of cracks on the high-density samples than on the low-density samples. Additionally, within each density group, a larger number of cracks were seen on sapwood samples as compared to heartwood samples. High-density samples with an alkyd- or an acrylic coating also showed a higher number of cracks. As expected, the formation of cracks on the samples increased their water sorption significantly. The microbial growth was higher on sapwood than on heartwood samples with a white coloured alkyd coating.

    The main conclusion is that heartwood and sapwood of different densities influence the water sorption and durability of coated Norway spruce. However, the principles in water sorption of uncoated heartwood and sapwood could not be applied to coated samples. Overall, the results point out that low-density heartwood could be the best material combination to improve the durability of coated spruce in outdoor use. The knowledge acquired in this thesis can enable an increased service life of coated spruce in outdoor use. The increase in service life is achieved by a careful selection of the wood material regarding the proportion of heartwood and to the choice of wood density. As a concluding remark, the role of surface-active spruce extractives needs to be explored, and a follow-up investigation in the context of water sorption is suggested for future research.

  • 5.
    Waxegård, Gustaf
    Linnaeus University, Faculty of Health and Life Sciences, Department of Psychology.
    Conceptualizing professionals' strategies in care pathways for neurodevelopmental disorders2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Neurodevelopmental disorders (ND), are complex neuropsychological functional impairments. About 3-5% of all children meet criteria for attention deficit and hyperactivity disorder (ADHD), and about 1% for autism spectrum disorder – along with intellectual developmental disorder the most common ND diagnoses. Degree and type of functional impairment vary greatly within and between patients, necessitating multi-professional assessment and treatment. Using classic grounded theory (Glaser), this thesis offers a new theory of professionals’ practices in care pathways for ND. It also contains a pilot evaluation of a new, tablet-based, clinical test of attention.

    Study I shows that care pathways for ND are characterized by social dilemmas. What is rational for an individual professional, team or clinic, is not always rational for the care pathway as a whole. Collective action therefor requires development and sustainability of inter-professional trust. The study highlights strategies used by professionals to decide on whether to act collectively or unilaterally. Such trust testing strategies are couched in the frameworks of social dilemma-theory and game-theory.  

    Study II emphasizes the importance of professional control over strategies, structures and methods in the care pathway for ND (unpacking control) to deal with ND-related complexity. Lack of such control can short-circuit the ability to work successfully as a professional. Unpacking control is understood mainly in the light of professions theory.

    Study III evaluates the new MapCog Spectra test as a rapid method to detect and assess clinical problems of attention. Four groups of children and adolescents took the test. Two groups were comprised of patients with either ND or other psychiatric problems. Two groups were comprised of school children without known clinical conditions. The MapCog Spectra test separated clinical from non-clinical groups with good precision.

    In the thesis, concepts from studies I and II are integrated and extended to form a unified theory about professional practices in care pathways for ND. The latters are suggested to be a particular form of commons, which can be collectively managed by professionals in more or less successful ways. A quantitative model for the dynamics in the care pathways is presented.

  • 6.
    Sandholm, Kerstin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Development and evaluation of immunoassays for complement diagnostics2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Laboratory analyses of human body fluids play an important role in clinical diagnosis. This thesis comprises projects in which various immune assays have been developed and evaluated as complement diagnostics in both plasma and cerebrospinal fluid (CSF). Various methods have been used, such as ELISA, Western blot, flow cytometry, and xMAP technology.

    In paper 1, we monitored complement parameters in EDTA-plasma and CSF from patients with suspected neuroborreliosis (NB) by using in-house sandwich ELISAs.  We found significantly elevated levels of C1q, C4, C3, and C3a in CSF, but not in plasma, suggesting that complement plays a role in the intrathecal immune response in NB.

    Complement is a main player in early inflammation, and in paper 2, we investigated the role of complement activation in phagocytosis and the release of cytokines and chemokines in response to two clinical isolates: Borrelia afzelii K78 and Borrelia garinii LU59. Our results show that complement activation plays an important role in the initial process of phagocytosis, but not in the subsequent cytokine release that occurs in response to live Borrelia spirochetes. C1q, a valuable biomarker of disease activity in systemic lupus erythematosus (SLE), can be quantitated using a number of different immunochemical techniques.

    In paper 3, we developed and validated a magnetic bead-based immunoassay for quantifying C1q in EDTA-plasma and CSF. In contrast to soluble immunoprecipitation assays such as nephelometry and turbidimetry, this new assay was not hampered by the interaction between C1q and detecting antibodies. The novel assay was shown to give a clear correlation between nephritis and SLEDAI score in SLE.

    Warfarin is a commonly used but complicated treatment in patients with thrombosis. It reduces the function of vitamin K-dependent coagulation proteins, including protein S, which is a ligand for C4b-binding protein (C4BP). In paper 4, we demonstrated a decrease in various isoforms of C4BP that resulted in a strong complement activation in patients treated with warfarin, but not in patients treated with other anticoagulants.

    Taken together, the results from the papers included in this thesis stress the importance of validated assays with high sensitivity and specificity in enabling accurate diagnosis in patients with various inflammatory diseases.

  • 7.
    Billsten, Johan
    Linnaeus University, Faculty of Health and Life Sciences, Department of Psychology.
    Dissemination and Implementation of the Swedish National Guidelines for Treatment of Substance use: – A five year evaluation2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis contains four empirical studies. The data derives from an evaluation project named Knowledge to Practice (KtP) that aimed to disseminate and implement the Swedish National Guidelines for Alcohol and Substance Abuse in Substance Use Disorder-treatment from 2010–2014. The aim of this thesis was to identify key determinants affecting implementation.

    The data collection consisted of:

    - Web surveys that were distributed annually from 2010–2014 to a panel of 3,852 respondents working in substance abuse treatment in social services and health care

    - Web surveys distributed to approximately 10,000 participants in the national core curriculum course. Surveys were distributed before the start of the course and immediately after the course ended. A follow-up web survey was distributed one year later

    - Semi-structured surveys for all regions’ user organizations to answer in focus groups

    - Interviews with process managers in every region

    The aim of Study I was to describe KtP's efforts and the situation in 2012. Web surveys were distributed to a panel of 3,852 respondents and 10,000 participants from core curriculum courses. Process managers from all 21 regions were interviewed. Study II used an instrument named Organizational Readiness for Change (ORC).The aim was to: (a) identify clusters of employees with different ORC profiles and (b) investigate whether belonging to a specific profile predicted the use of therapy methods, assessment instruments and cross-sectional collaboration. The ORC instrument was part of an annual web survey to a panel of 3,852 respondents.The aim of Study III was to evaluate, via a four-year follow-up study, whether user organizations continued existing after national support concluded and if their influence within social services and health care was implemented over time. The aim of Study III was to evaluate, via a four-year follow-up study, whether user organizations continued existing after national support concluded and if their influence within social services and health care was implemented over time. The aim of Study IV was to evaluate the extent of the dissemination and implementation work organised by KtP and whether there was increased use of treatment methods, assessment instruments and changes in cross-sectional collaboration between authorities. Factors associated with success were studied on three organizational levels: regional, municipal and individual. Results show that setting and person-related determinants, as measured by the ORC instrument, predicted implementation of assessment instruments and treatment methods. Profiles with high scores on institutional resources, staff attributes and organizational climate and low scores on motivational readiness were associated with more successful implementation. Respondent-level specialist competence and the ORC factors of staff attributes and institutional resources were related to the use of treatment methods. The ORC factor of organizational climate was related to the increase of cross-sectionalcollaboration at a respondent level. Years of employment working with substance users predicted increased use of assessment instruments and in contrast, the ORC factor institutional resources available were negatively related to instrument use. No predictors were found at the region/municipality level. The majority of respondents were positive to the national guidelines and found them useful in their daily work. They also reported positive attitudes to the KtP project. In 2011, two-thirds of the process managers from Sweden's 21 counties assessed that KtP's most important results were access to education and method support. The one-year follow-up web survey distributed to the participants in core curriculum courses showed that memory retention of the course content was fair. Eighty per cent of the respondents gave the correct answer to seven out of nine questions. User organizations still existed in most regions and they reported increased influence in the field of substance use treatment, both in social services and within health care services.

  • 8.
    Jonsdottir, Sigridur Sia
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Effects of perinatal distress, satisfaction in partner relationship and social support on pregnancy and outcome of childbirth2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aim: The aim of this thesis was to achieve a deeper understanding of the situation among women experiencing perinatal distress during pregnancy and childbirth and the effects that dissatisfaction in partner relationship and weak social support from family and friends could have on pregnancy and childbirth.

    Methods: Following screening for perinatal distress, 562 expecting mothers came for a semi-structured interview. This screening, done with the Depression Anxiety Stress Scales and the Edinburgh Postpartum Depression Scale, categorized 360 (64.1%) women into the perinatal distressed group (PDG) and 202 (35.9%) into the non-distressed group (NDG). During the interview women answered the Dyadic Adjustment Scale and the Multidimensional Scale of Perceived Social Support. Data were collected with these instruments for study I. Additional data for the three other studies were gathered from the women´s pregnancy records (II), electronic medical records (II, III), and childbirth records (IV). Results of the four studies were obtained by using descriptive statistics; parametric and nonparametric statistics and regression modeling.

    Results: Women in the PDG were significantly more likely than the NDG to be dissatisfied in their partner relationship, continue smoking during pregnancy, be dissatisfied with division of household tasks and child-rearing, have elementary or lower education, and to be students or unemployed. They were also significantly more likely to experience fatigue, vomiting and pelvic girdle pain during pregnancy. Women in the PDG who received weak family support reported nausea and heartburn more frequently than those with strong family support. Women in the PDG utilized more antenatal care service and were allocated more part time as well as earlier sick leaves during pregnancy, than those in the NDG. Women in the PDG were significantly more likely to use epidural anesthesia as a single pain management during labor.

    Conclusion: Perinatal distress affects pregnancy and childbirth. It is more common among women who are dissatisfied in their partner relationship and with the division of household tasks and child-rearing. Perception of weak social support also affects pregnancy among distressed women. Distressed women along with their partners and families should be offered support and consultation to relieve distress and strengthen their bonds during pregnancy and childbirth.  

  • 9.
    Osbeck, Christofer
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Exploring gene expression responses of marine bacteria to environmental factors2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Bacterioplankton are abundant in marine ecosystems, where they as “masters of transformation” of dissolved organic matter (DOM) are important for energy fluxes and biogeochemical cycles. However, the performance of bacteria in a changing marine environment influenced by anthropogenic activities is poorly understood. In this thesis, I did experiments with model bacteria and natural assemblages of bacteria, using microbiology methods combined with modern molecular tools, to investigate responses of marine bacteria to changes in environmental conditions like ocean acidification, organic pollution and organic matter released by phytoplankton. Experiments with a model gammaproteobacterium demonstrated that bacteria in stationary phase showed little responses to organic pollutants, whereas pollutants caused decreased bacterial growth and had a broad physiological impact on actively growing bacteria (as deduced from gene expression analysis). In an experiment with two distantly related marine model bacteria, we identified several important bacterial mechanisms, such as uptake of macromolecules and phosphonates, by which bacteria respond when exposed to DOM produced by photosynthetic dinoflagellates. Using natural bacterial communities in a Baltic Sea mesocosm experiment with the addition of river water from a forested or an agriculture influenced catchment area, we showed important interactions between river water type and the development of phytoplankton blooms that caused different bacterial gene expression activities. In the fourth set of experiments, marine bacterial communities were subjected to elevated CO2, to mimic ocean acidification, under high and low nutrient conditions in a mesocosm study. We found increased bacterial gene expression activity focused on maintaining pH homeostasis, but only under low nutrient conditions, indicating that bacteria focus on cell maintenance instead of growth when challenged by lowered pH. Finally, in a computational analysis, we compared genomes from yet uncultivated prokaryotes by two different strategies: metagenome assembled and single amplified genomes. Importantly, the analysis showed that both methods selected abundant taxa and generated nearly identical sequences in overlapping regions. To conclude, this thesis presents discoveries that will help form a better understanding of marine bacterial responses to present and future anthropogenic disturbances of marine ecosystems.

  • 10.
    Eriksson, Katarina
    Linnaeus University, School of Business and Economics, Department of Management Accounting and Logistics.
    Finance and Supply Chain Management: Coordination of a Dyadic Supply Chain through Application of Option Contracts2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of this dissertation is to study the relationship between dyadic supply chain flexibility and dyadic supply chain profitability.

    In today’s global environment, competition is no longer limited to companies but has evolved to supply chains. Supply disruption, lead time uncertainty and stochastic demand can result in costly inefficiencies of up to 40% when companies are trying to coordinate ordering and production. A dyadic supply chain competing in a global economy cannot afford to end up with a 40% smaller share of the pie.

    This thesis applies theory and instruments from finance, specifically portfolio theory and real options theory when applying option contracts to create flexibility in a dyadic supply chain.

    The methodology applied was to conduct an initial literature review of prior research to establish research gaps (first paper). This resulted in the development of an algorithm (second paper) combining the base stock model and the option mechanism to create flexibility for an OEM and supplier to coordinate ordering and production bilaterally in a multi-period setting. In the third paper the algorithm was applied to a case study using data from two companies, which resulted in the algorithm being tested and validated. Furthermore, option contract theory was integrated with dyadic supply chain practise while Fisher portfolio paradox was addressed.

    The dissertation contributes in the following areas: the empirical contribution is evidence of the relationship between dyadic supply chain flexibility and profitability using quantitative data from two companies.

    The methodological contribution is a method for the objective valuation of dyadic supply chain flexibility and the measurement of profitability, by valuing the option contract.

    The theoretical contribution is achieved through the integration of portfolio and option theory into SCM while addressing Fisher’s portfolio paradox.

    The practical contribution is an algorithm that creates flexibility for an OEM and asupplier to coordinate ordering and production bilaterally and maintain its collaborative advantage when competing in a global economy, thus avoiding ending up with a 40% smaller share of the pie. In addition, this dissertation advances this topic in SCM into a quantitatively measurable theory.

  • 11.
    Österlund, Erik
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Going beyond on-the fly-garbage collection and improving self-adaptation with enhanced interfaces2019Doctoral thesis, comprehensive summary (Other academic)
  • 12.
    Zimmer, Björn
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Guided Interaction and Collaborative Exploration in Heterogeneous Network Visualizations2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The visual exploration of large and complex network structures remains a challenge for many application fields, such as systems biology or social sciences. Often, various domain experts would like to work together to improve the analysis time or the quality of the analysis results. Collaborative visualization tools can facilitate the analysis process in such situations. Moreover, a growing number of real world networks are multivariate and often interconnected with each other. Entities in a network may have relationships with elements of other related data sets, which do not necessarily have to be networks themselves, and these relationships may be defined by attributes that can vary greatly. A challenge is to correctly assign the attributes and relations between different data sets and graphs in order to be able to analyze them visually afterwards. The navigation between the resulting visualizations is also difficult. How can users be guided to other interesting data points relevant to their current view and how can this information be additionally displayed in a graph without losing the overview of the data?

    In this dissertation, we propose our new web-based visualization environment OnGraX, which supports distributed, synchronous and asynchronous collaboration of networks and related multivariate data sets. In addition to standard collaboration features like event tracking or synchronizing, our client/server-based system provides a rich set of visualization and interaction techniques for better navigation and overview of the input network. Changes made by specific analysts or even just visited network elements can be highlighted by heat maps, which enable us to visualize user behavior data without affecting the original graph visualization. We evaluate the usability of the heat map approach against two alternatives in a user experiment.

    Additional features of OnGraX include a comprehensive visual analytics approach that supports researchers to specify and subsequently explore attribute-based relationships across networks, text documents, and derived secondary data. Our approach provides an individual search functionality based on keywords and semantically similar terms over an entire text corpus to find related network nodes. For examining these nodes in the interconnected network views, we introduce a new interaction technique, called Hub2Go, which facilitates the navigation by guiding the user to the information of interest. To showcase these features, we use a large text corpus collected from papers listed in the IEEE VIS publications data set (1990--2015) that consists of 2,752 documents. We analyze relationships between various heterogeneous networks, a Bag-of-Words index, and a word similarity matrix, all derived from the initial corpus and metadata. We also propose a design for the interactive specification of degree-of-interest functions, which can be used to provide and evaluate configurations for guidance based on network attributes and logged user data in heterogeneous networks.

  • 13.
    Eklund, Andreas
    Linnaeus University, School of Business and Economics, Department of Marketing.
    Harmonising value in a car’s interior using sensory marketing as a lens2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The human senses have always influenced people’s perceptions of thesurrounding environment and objects. As a consequence of the evolvement ofthe experience economy, research on the human senses has increasedsubstantially and attracted scholars from various research domains, includingsensory marketing. In the marketing domain, research emphasises that value iscreated when consumers experience brands, products, and servicescapes that areexciting and fun to interact with through the human senses. In accordance withthe service-dominant logic discussion, value is created from the servicesurrounding the product, such as the experience, which includes manufacturersand consumers. Although this has partly been captured under sensorymarketing, little is known of how sensory marketing cues contribute to brandexperience and brand value. Theoretically, it is emphasised that creating valueis a service process, where the manufacturer’s goal is to plan and design amultisensory brand experience facilitated by the human senses leading toconsumer value, as well as to enhance the brand as an image. Hence, the purposeof this dissertation is to understand and explain how value is created within acar’s interior by applying sensory marketing as a lens.

    To address the purpose, an exploratory sequential mixed methods approachwas employed to capture different aspects of creating value. The empirical dataare based on a case study with a global premium car manufacturer, focusing onhow value is created and offered within a car’s interior. The qualitative sequenceexplored how the manufacturer plans and designs a value proposition byembedding sensory cues in the car’s interior. Furthermore, how value-in-use iscreated by providing a brand experience is analysed. The quantitative sequenceexamined the relationship between brand experience and brand image to explainhow consumer value as an experience is created.

    The dissertation concludes that creating value in the car’s interior followsthe logic of service-dominant logic and includes manufacturers and consumers.For the manufacturer, this was a strategic process to position the automotivebrand as premium by offering value in the car’s interior. To achieve this, valuewas planned and designed by embedding sensory cues in the car’s interior.However, sensory cues were not embedded in isolation; rather they wereharmonised with another to gestalt the coherent theme of Scandinavia in termsof colour, material, and shape to provide consumers with a brand experience forsense-making. Moreover, it was demonstrated that not all brand experiencedimensions impact brand image to create value as an experience. The resultsshow that sensory, affective, and harmony experience have a positiverelationship with brand image, which generates the consumer’s value as anexperience.

    Overall, the dissertation contributes to the process of creating value in thecar’s interior by relating sensory marketing with branding and service-dominantlogic, with harmony uniting these. Similar to an orchestra, where the conductorstrategically organises various instruments on the stage to play a harmoniousmelody for the audience, the manufacturer uses the car’s interior as a stage withsensory cues to provide consumers with a harmonious brand experience, leadingto a positive brand image. Harmony has been identified, operationalised,measured, and tested with a positive result. Theoretical, managerial, and ethicalimplications are discussed.

  • 14.
    Lindblad, Fredrik
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Identifying drivers and barriers for market growth within the industry producing wooden multi-family houses: Land allocation process for future growth2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    At present, Sweden is experiencing a housing shortage, which Swedish authorities expect to continue until at least 2025. Producers of wooden multi-family houses have a relatively small market share compared to those who use traditional building materials. Limited ability to meet the increased building demand restricts possibilities for development regarding innovation, bio-economy and sustainability.

     

    Swedish municipalities are responsible for planning the building development in their regions based on their projected requirements and strategies. Combining this with a desire to develop sustainable building solutions based on wood increases complexity in the public procurement process. Currently, public building developments are achieved through the Public Procurement Act or land-allocation activity, depending on the development strategy. This normally involves developing local strategies regarding, e.g. design, material choice and geographical development. Identifying drivers and barriers in the industry and market enables improved market entry activities related to public building initiatives using wood-based solutions. Hence, improving transparency in land-allocation activity generates possibilities for companies to respond successfully to requests from municipalities. This knowledge is used to better understand the required strategic development for companies, the government and municipalities to increase use of sustainable building materials such as wood in Swedish multi-family housing projects.

     

    Results show that the industry experiences barriers associated with municipalities' actions and knowledge related to wood as a building solution. Further, concrete’s strength as a building material is an issue, since municipalities tend to opt for familiar solutions. Furthermore, the way in which municipalities manage land-allocation activity is perceived as insufficient, with limited information, a subjective evaluation process, and uncertainties regarding their roles in the process. These factors contribute to ambiguity and sub-optimisation for developers proposing wood-based building solutions.

  • 15.
    Johansson, Maria
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Intensivvårdsdagbok i Sverige: betydelse och tillämpning2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aim: The overall aim of the thesis was to explore how the Intensive Care Unit (ICU) diary was experienced by family members, family members of non-survivors and nursing staff in the ICU setting, thereby contributing to the development of national clinical practice guidelines regarding the structure, content and use of the ICU diary.

    Methods:  A qualitative design was employed for all four studies:  a hermeneutic approach was adopted in studies I and II, whilst a qualitative descriptive design with the use of focus groups interviews was chosen in study III. An Instrumental Multiple Case Study design was carried out in study IV.

    Main Findings: The diary symbolised the maintenance of relationships with the patients and was a substitute for the usual opportunities for communication. The diary was instrumental in meeting the needs of the majority of participant family members. The diary provided the means to be present at the patient’s bedside, to feel involved in caregiving, to maintain hope and to relay relevant information. If the critically ill family member did not survive the stay in the ICU, the diary acted as a form of bereavement support by processing the death of the patient. Nevertheless, some family members found the diary too public an arena to write in as the diary entries indicated visiting patterns which in turn provoke feelings of guilt when the visits were infrequent. Further, not knowing what to write was another source of pressure.

    Nursing staff experienced that writing diaries often felt meaningful and led to an increased motivation and engagement in patient care and family support. They expressed that they felt they did something good for the patient and family members. Thus, the diary can be seen as a way to promote person-centred care, where family members were offered to participate in the care. However, in the absence of guidelines or clear guidelines about the use of an ICU diary, then not many patients actually received a diary.

    Conclusions: Practice guidelines concerning ICU diaries would help to ensure the more widespread and consistent use of diaries for all ICU patients. As family members may benefit from the diary, even if the patient may not always be able to do so. The ICU diary can be seen as a tool to help promote person-centred care by directly involving family members and providing a human touch, thus helping to counterbalance the highly technical physical environment of ICU.

  • 16.
    Hanell, Fredrik
    Lund University, Sweden.
    Lärarstudenters digitala studievardag: Informationslitteracitet vid en förskollärarutbildning2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This dissertation reports on an investigation into how digital tools are used, negotiated and given meaning in Swedish pre-school teacher education. The overall aim has been to create a deeper understanding of how students’ information literacies are enacted when digital tools are used and appropriated in the daily life at a pre-school teacher education, in relation to conceptions of the digitalisation of teacher education in national policy. A netnographical study at a pre-school teacher education was conducted between 2012 and 2015. The study generated online material, mainly from a Facebook Group used by students and teacher, and field notes from participant observations, transcribed interviews and a field diary. Through application of a socio-cultural perspective on information literacy, the netnographical material was analysed using the concepts appropriation and identity. To analyse the discursive level, four national policy documents with demands for increased digital competence in teacher education were analysed using Carol Bacchi’s ‘what’s the problem represented to be?’ approach.

    The findings show how views on learning and identity interact with the materiality of the digital tools and the enabling and constraining properties of the local learning environment when information literacies are enacted. The identity position discussion-oriented student is connected to how the Facebook Group is appropriated as a relation-building tool and a relational information literacy. This type of information literacy entails a view on learning as co-learning, rooted in the historical development of pre-school teacher education, and a non-hierarchical understanding of teacher and student roles. The identity positions goal-oriented student and customer-oriented student are connected to how the Facebook Group is appropriated as a collaborative problem-solving tool and a pragmatic information literacy. This form of information literacy reflects instrumental and neoliberal views on learning, and a traditional understanding of teacher and student roles. The policy analysis shows how an economic and competitive perspective underpins demands for increased digital competence in teacher education, and how the value of digital tools for learning and teaching is taken for granted. The idea of co-learning, that is found to be influential but not fully accepted at the pre-school teacher education, is difficult to combine with an economic perspective emphasising measurability and quantification. The economic perspective is partly compatible with a pragmatic information literacy. The findings of the dissertation shed light on the gap between what is described as important in policy documents and what teacher students and teachers describe as important when digital tools are used in teacher education.

  • 17.
    Olsson, Jörgen
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. RISE Research Institutes of Sweden, Sweden.
    Low Frequency Impact Sound in Timber Buildings: Transmission Measurements and Simulations2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An increased share of multi-story buildings that have timber structures entails potential in terms of increased sustainability as well as human-friendly manufacturing and habitation. Timber buildings taller than two stories were prohibited in Europe until the 1990s due to fire regulations. In 1994, this prohibition was removed in Sweden. Thus, being a rather new sector, the multi-story timber building sector lags behind in maturity compared to the multi-story concrete sector. The low-frequency range down to 20 Hz has been shown to be important for the perception of the impact of sound in multi-story apartments with lightweight floors. This frequency range is lower than the one that has traditionally been measured according to standards and regulations. In small rooms, the measurement conditions tend to go from diffuse fields above 100 Hz to modal sound fields dominated by few resonances, below 100 Hz. These conditions lead to new challenges and to new possibilities for measurements and modelling.

    In the present research, a frequency response functions (FRFs) strategy aimed to simplify simulations and correlations between the simulations and test results was used. Measurements made indicate that, in the low frequencies, the highest sound pressures occur at the floor level opposite the ceiling / floor that is excited. By having an iterative measurement strategy with several microphones and making measurements until a required standard error is obtained, it is possible to gain a desired precision and information about the statistical distribution of both the sound fields and floor insulation performance. It was also found that, depending on the excitation source, the FRF from an excitation point on the floor above to the sound pressure at a microphone position in the room below may differ. This indicates that non-linearities in sound transmissions are present. Thus, the excitation source used in a test should be similar in force levels and characteristics to the real excitation stemming, for instance, from a human footfall, to achieve reliable measurement results. The ISO rubber ball is an excitation source that is close to fulfilling this need. In order to obtain an FRF, the impact force must be known. A rig that enables the impact force from a rubber ball to be measured was developed and manufactured. The results show that the force spectra are the same up to about 55 Hz, regardless of the point impedances of the floors excited in the tests. Similar results have been found by others in tests with human excitations. This means that FRFs up to about 55Hz can be achieved without actually measuring the excitation force.

    On the calculation side, finite element simulations based on FRFs may offer advantages. FRFs combined with the actual excitation force spectra of interest give the sound transmission. At higher frequencies, it is more important to extract the point mobilities of the floors and relate them to the excitation forces. By using an infinite shaft, sound transmission can be studied without involving reverberation time. The calculation methodology is used in the present research to evaluate different floor designs using FE models.

  • 18.
    Ivanenko, Yevhen
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Optimization and Physical Bounds for Passive and Non-passive Systems2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Physical bounds in electromagnetic field theory have been of interest for more than a decade. Considering electromagnetic structures from the system theory perspective, as systems satisfying linearity, time-invariance, causality and passivity, it is possible to characterize their transfer functions via Herglotz functions. Herglotz functions are useful in modeling of passive systems with applications in mathematical physics, engineering, and modeling of wave phenomena in materials and scattering. Physical bounds on passive systems can be derived in the form of sum rules, which are based on low- and high-frequency asymptotics of the corresponding Herglotz functions. These bounds provide an insight into factors limiting the performance of a given system, as well as the knowledge about possibilities to improve a desired system from a design point of view. However, the asymptotics of the Herglotz functions do not always exist for a given system, and thus a new method for determination of physical bounds is required. In Papers I–II of this thesis, a rigorous mathematical framework for a convex optimization approach based on general weighted Lp-norms, 1≤p≤∞, is introduced. The developed framework is used to approximate a desired system response, and to determine an optimal performance in realization of a system satisfying the target requirement. The approximation is carried out using Herglotz functions, B-splines, and convex optimization. 

    Papers III–IV of this thesis concern modeling and determination of optimal performance bounds for causal, but not passive systems. To model them, a new class of functions, the quasi-Herglotz functions, is introduced. The new functions are defined as differences of two Herglotz functions and preserve the majority of the properties of Herglotz functions useful for the mathematical framework based on convex optimization. We consider modeling of gain media with desired properties as a causal system, which can be active over certain frequencies or  frequency intervals.  Here, sum rules can also be used under certain assumptions.

    In Papers V–VII of this thesis, the optical theorem for scatterers immersed in lossy media is revisited. Two versions of the optical theorem are derived: one based on internal equivalent currents and the other based on external fields in terms of a T-matrix formalism, respectively. The theorems are exploited to derive fundamental bounds on absorption by using elementary optimization techniques. The theory has a potential impact in applications where the surrounding losses cannot be neglected, e.g., in medicine, plasmonic photothermal therapy, radio frequency absorption of gold nanoparticle suspensions, etc.  In addition to this, a new method for detection of electrophoretic resonances in a material with Drude-type of dispersion, which is placed in a straight waveguide, is proposed.

  • 19.
    Sjöstrand Öhrfelt, Magdalena
    Linnaeus University, Faculty of Social Sciences, Department of Education and Teacher's Practice.
    Ord och inga visor: konstruktioner av förskolebarnet i kunskapsekonomin2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Historically, changes in preschool policy have been legitimized in relation to ideas about the preschool child and the various problems that the education of this child is supposed to be able to “solve”. From an early age, children have been considered the most effective tool for dealing with a variety of social, economic or environmental issues of central importance for maintaining and developing society.

    Against this background, the purpose of this thesis is to examine representations of the preschool child in different policy texts (textbooks, research- and educational policy) related to changing requirements and targets affecting contemporary Swedish preschools. Discursive constructions of the preschool child are considered as important central aspects, used to legitimize political reforms in accordance with pedagogical ideas and prevailing social contexts. The thesis focuses on the tensions within contemporary constructions of the preschool child in the so-called “knowledge economy”: i.e. the tensions between a competent child, who is both able and willing to take advantage of education, and a “newcomer” – the vulnerable child – in need of obtaining the benefits of education in order to be able to cope with the future.

    The simultaneously competent and vulnerable preschool child is thus an efficiently designed target for the interests of economic transnational organizations viewing education mainly in terms of human capital development, as well as an important factor for economic competitiveness.

    In the thesis’ final analysis, I study how the OECD, EU and IEA are developing methods for measuring and evaluating the results of preschool education, with the intention of being able to "streamline" it by finding universally successful concepts that are both cost-effective and of high quality. The construction of the preschool child as simultaneously competent and vulnerable is used to legitimize shifts in power over the definition of the Swedish preschool agenda, the fundamental ideas of what preschool is about, what its aims are, and for whom it is intended. As these ideas are disguised as being the result of supposedly "objective" forces far from the ideological contradictions of the political sphere, a critical discussion concerning the goals and aims of early childhood education becomes almost impossible to achieve.

  • 20.
    Vingare, Emme-Li
    Linnaeus University, Faculty of Social Sciences, Department of Social Work.
    Paradoxer i välfärden: När anhöriga blir lösningen på demensomsorgens utmaningar2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis addresses dementia care in Sweden and the function family caregivers are given. The aim of the thesis is to analyse critically the system of municipal eldercare and the function of family caregivers in this system, and in various types of organisations. In the thesis, both organisational perspectives and the experiences of family caregivers are in focus. Eldercare has been a focus of the welfare state from its early days. Throughout the years both the organisation of care and the understanding of responsibility between family and state has changed several times. Today, family caregivers in Sweden have no formal responsibility for people with dementia, but many family caregivers still take on a caregiver responsibility. This raises questions about the function family caregivers play in dementia care and the reasons behind the choice of caregiving. The thesis consists of four papers on which a cumulative analysis was made. The empirical material is based on interviews with 146 family caregivers, of which 55 answered additional questions. Furthermore, a mapping study of activities and professional specialisation was used to study variations between municipalities. Text material was also utilised, both in the form of policies and formal documentation on a municipal level, and on research on family caregiving in dementia care on a national level. The cumulative analysis was made from the perspective of critical systems theory and resulted in three paradoxes: The welfare paradox, the value paradox and the responsibility paradox. The paradoxes are closely connected, and limit agency among family caregivers. Opposition in processes of familisation (the welfare paradox), individual values rather than family values (the value paradox), and the limitations in factual choice in taking on a caregiver responsibility (the responsibility paradox) cooperate in shaping the function of family caregiving and simultaneously limiting family caregiver agency. Since it is in the interest of dementia care to involve family caregivers the paradoxes also contribute to a solution to challenges in dementia care.

  • 21.
    Johansson, Maude
    Linnaeus University, Faculty of Health and Life Sciences, Department of Psychology.
    Postpartum depression, depressive symptoms and parental stress in mothers and fathers 25-30 months after child birth: A family perspective2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aim of this thesis was to explore the prevalence of postpartum depression and parental stress 25 - 30 months after delivery. The first study was conducted 25 months after delivery. The aims were to investigate the prevalence of postpartum depression and the associations between postpartum depression and parental stress in two areas of study; spouse relationship problems and feelings of incompetence in parenthood. Seven hundred mothers and 646 fathers answered a questionnaire. The results showed that the prevalence of depressive symptoms was more than 11% for mothers and nearly 5% for fathers and that parents with postpartum depressive symptoms experienced more feelings of incompetence and spouse relationship problems than parents without postpartum depressive symptoms.

    The second study included 176 mothers and 146 fathers. The aims of the study were to determine the prevalence of postpartum depressive symptoms, and if parental stress and attachment style affected postpartum depression in mothers and fathers 30 months after birth. The prevalence rate of postpartum depressive symptoms in mothers was 14.9 %, while for fathers it was 11.5 %. We observed a difference with the preoccupied and fearful attachment style in terms of parents with postpartum depressive symptoms and parents without postpartum depressive symptoms. However, the differences were not significant. Furthermore, parental stress outperformed attachment styles as a predictor for postpartum depressive symptoms in both the mothers and the fathers.

    Study III was a qualitative interview study explored the lived experiences of mothers and fathers, their experiences of postpartum depression, and parental stress. Five prominent themes were identified. Both mothers and fathers described experiences of inadequacy as the most stressful. Experiences of problems during pregnancy or a traumatic delivery contributed to depressive symptoms and anxiety in mothers, and affected fathers’ wellbeing.

    Thus, identifying depressive symptoms with the Edinburgh Postnatal Depressive Scale (EPDS), mothers described varying experiences of child health care support. Depressive symptoms seemed to affect the spouses’ relationships. Experiences of emotional problems and insecure upbringing in the parents’ family of origin may contribute to vulnerability that led to long-term problems for mothers.

    The overall conclusion of this thesis was that postpartum depression and parental stress had a significant impact on the everyday lives and that postpartum depression does not seemed to decline 25- 30 months after childbirth.

  • 22.
    Thulin, Johanna
    Linnaeus University, Faculty of Social Sciences, Department of Social Work.
    Putting words to child physical abuse: Possible consequences, the process of disclosure, and effects of treatment. From children’s perspectives2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aim: The overall aim of the thesis is to explore the experiences and possible consequences concerning reported health and relations between a parent perpetrator of physical child abuse and the children who are victims of the parental physical abuse, the children’s thoughts when disclosing the abuse, and the impact of an intervention designed to support these children in a Swedish context – Combined Parent Child Cognitive Behavioral Therapy (CPC-CBT). Methods: This thesis has a mix-method design. Study I and IV used different self-assessment scales, and the outcomes were analysed using descriptive statistics, paired-samples t test, independent t test, ANOVA, Pearson correlations, and hierarchical linear regression. Study II and III consisted of interviews with 15 (Study II) and 20 (Study III) children, respectively. The interviews were transcribed verbatim and analysed using qualitative content analysis. Results: The results suggest that experiencing child physical abuse affects the relationship between a parent and a child as well as the child’s wellbeing in several ways. However, the results also suggest that participating in the CPC-CBT intervention could decrease parents’ use of violence and increase the child’s wellbeing. In addition, the results suggest that trust and participation influence whether a child discloses abuse and contributes to the success of treatment. Conclusion: The CPC-CBT could be seen as a successful turning point for the participating children, shifting from one trajectory (living in fear of violence) to another (living without fear). Furthermore, when children disclose to adults about their physical abuse, it is important that the adults recognise the children’s participatory rights and strive to earn their trust.

  • 23.
    Ahlryd, Sara
    University of Borås, Sweden.
    På gränsen till en ny värld: studenters informationspraktiker på väg mot arbetslivet2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    With the increasing academisation of vocational educations the need for higher education to prove to students the relevance of theoretical domain knowledge to professional experience is growing. One way of doing so is to provide students with opportunities for professional training during the course of their studies. The aim of this thesis is to explore the ways in which professional training help students to connect education with working life. The study is carried out through a practice theoretical lens on students’ information practices. It also entails exploring how their information activities contribute to their socialization within workplace communities and to their construction of professional identities. Through qualitative semi-structured interviews, the empirically driven analysis shows that students’ appropriation of information practices during professional training support learning, socialization into a workplace as well as identification with their future professional roles. Students’ information practices can be viewed as significant tools in the process of transition between education and profession where they function as facilitators for learning and participation in workplace activities. 

  • 24.
    Ståhlkrantz, Katarina
    Linnaeus University, Faculty of Social Sciences, Department of Pedagogy and Learning.
    Rektors pedagogiska ledarskap: en kritisk policyanalys2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The pedagogical leadership is regarded as the most significant of the principal ́s duties. Because there is no clear definition of pedagogical leadership as a concept, it may be difficult for the principal to know how to practice it. Various versions of the concept’s meaning are currently circulating, in turn offering different norms to relate to and act upon. This doctoral thesis takes its point of departure from the policy proposal of a Rektorslyft in the Swedish national budget of 2011, as a solution to the problem that principals were not considered to be good enough pedagogical leaders. The study is designed as a critical policy analysis, with a curriculum theory framework and a critical interpretative perspective. The critical approach is directing focus towards the steering of the school. Further, a poststructuralist perspective adds a discursive approach to the study. The empirical material consists of a selection of official education policy documents, mainly governmental official reports. The aim of the study is to examine and analyse how the pedagogical leader is discursively constructed in official education government documents, what changes and stabilities can be distinguished in these discursive constructions over time and how these can be understood and explained. Bacchi ́s WPR-method and Foucault ́s genealogy is used as a methodological framework for the text analysis. The result shows six discursive breakpoints in the construction of the pedagogical leader from the 1950s to 2010s. These breakpoints have a close relationship to changes in school steering. Principals’ pedagogical leadership can therefore be regarded as a policy to legitimise new steering reforms. The result further indicates that principals from the 1950s to 2010s were given a clearer personal responsibility within the pedagogical leadership. The changes identified through the critical policy analysis can be explained by the context and policy streams. The text analysis also indicated stabilities in the discursive construction of the pedagogical leader. These stabilities can be explained by traditions and school structures. Hopefully, this study has contributed to a better and deepened understanding of principals’ pedagogical leadership, as well as have given the concept an empirical and theoretical basis.

  • 25.
    Svensson, Anders
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Räddningsaktörers tidiga närvaro vid akuta situationer på svensk landsbygd2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aim: The overall aim was to describe the first responders´ (FRs) experiences ofarriving early at emergency situations in rural areas in Sweden and the characteristicfeatures of the assignments they encounter. The four studies aimed to: describe critical incidents in which ambulance nurses experience worry in their professional life and the actions they take in order to prevent and cope with it (I), explore and describe experiences of the First Incident Person (FIP) assignment within an Fire Department (FD) (II), describe experiences of the While Waiting for the Ambulance (WWFA) assignment, as experienced by home healthcare nurses (III) and map out and describe WWFA assignments focusing on frequency, event time,CardioPulmonary Resuscitation (CPR) and survival >30 days after performed CPR (IV).

    Methods: The four studies in this thesis had both descriptive and explorative designs. They were analysed with qualitative and quantitative analysis methods.

    Results: By dispatching FRs in rural areas an early presence at the scene of anaccident or emergency situation can be secured, which prevent full scenarios to happen and increase the possibility to save lives. However, FRs are worried about specific emergency situations as well as situations related to their work environment.Leaving ongoing work tasks cause ethical dilemmas and inner emotional worries why support before, during and after an FR assignment is sought for.

    Conclusions: Generating effective interprofessional collaboration during FR assignment requires that the FRs work conditions are adopted to the assignment requirements for immediate response. The feeling of security disappears when the FRs are excluded from the group affiliation and the need to feel support in new interprofessional collaboration structures becomes clear. Support function based on individual requests is to be designed. Continuous collaborative exercises are required where all involved FRs participate.

  • 26.
    Kucher, Kostiantyn
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Sentiment and Stance Visualization of Textual Data for Social Media2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Rapid progress in digital technologies has transformed the world in many ways during the past few decades, in particular, with the new means of communication such as social media. Social media platforms typically rely on textual data produced or shared by the users in multiple timestamped posts. Analyses of such data are challenging for traditional manual methods that are unable to scale up to the volume and the variety of the data. While computational methods can partially address these challenges, they have to be used together with the methods developed within information visualization and visual analytics to gain knowledge from the text data by using interactive visual representations.

    One of the most interesting aspects of text data is related to expressions of sentiments and opinions. The corresponding task of sentiment analysis has been studied within computational linguistics, and sentiment visualization techniques exist as well. However, there are gaps in research on the related task of stance analysis, dedicated to subjectivity that is not expressible only in terms of sentiment. Research on stance is an area of interest in linguistics, but support by computational and visual methods has been limited so far. The challenges related to definition, analysis, and visualization of stance in textual data call for an interdisciplinary research effort. The StaViCTA project addressed these challenges with a focus on written text in English. The corresponding results in the area of visualization are reported in this work, based on multiple publications.

    The main goal of this dissertation is to define, categorize, and implement means for visual analysis of sentiment and stance in textual data, in particular, for social media. Our work is based on the theoretical framework and automatic classifier of stance developed by our project collaborators, involving multiple non-exclusive stance categories such as certainty and prediction. We define a design space for sentiment and stance visualization techniques based on literature surveys. We discuss multiple visualization and visual analytics approaches developed by us to facilitate the underlying research on stance analysis, data collection and annotation, and visual analysis of sentiment and stance in real-world text data from several social media sources. The work described in this dissertation was carried out in cooperation with domain experts in linguistics and computational linguistics, and our approaches were validated with case studies, expert user reviews, and critical discussion. The results of this work open up further opportunities for research in text visualization and visual text analytics. The potential application areas are academic research, business intelligence, social media monitoring, and journalism.

  • 27.
    Henriksson, Kristina
    Linnaeus University, Faculty of Social Sciences, Department of Education and Teacher's Practice.
    Skolbesökets osynliga bedömningsprocesser: en studie av hur lärarstudenters yrkeskunnande bedöms under verksamhetsförlagd utbildning2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis treats the assessment of student teachers’ professional skills within the school-based section of Swedish teacher education, more specifically the school visits organized by the university. School visits ordinarily consist of an observed lesson, followed by a post-observation conference. School-based teacher education is regarded as a specific educational element, where the education is transferred to the organisation of professional teachers who educate the student teacher. However, there is a lack of direct research about what happens to the assessment of the student teacher’s proficiency when the assessment system of the education is applied outside the university domain. Research shows that there is tension regarding the view of professional skills between players in teacher education and school organisations, and uncertainties regarding the mandate to develop the student teacher’s professional skills. From a political perspective the school visit is perceived as a guarantee for the fulfilment of the increasing demands for equal and legally secure assessments. The aim of this thesis has therefore been to enhance the understanding of the function of assessment within school-based teacher education. The interactive assessment process of the post-observation conference has been in focus and studied through video observations and interviews. The study assumes multiple theoretical perspectives; a new institutional perspective, Goffman’s interactionist perspective and a professional theoretical perspective. The result shows that simultaneous and conflicting assessment logics guide the assessment task, creating protective and defensive interaction patterns to establish a loyal consensus between conference participants. The situation needs to be played down. The interactive patterns of the conference counteract the institutional logics of the visit, making access to information selective and limited. Judgements and feedback become invisible and the aim of the assessment process is unclear. The controlling purpose of the process, and partly also the formative purpose, is impaired. However, in the execution of assessment itself, assessment logics collaborate with interaction patterns, displaying a secondary adaptation to the situation. This collaboration contributes to a reasonable and legitimate manner of executing the assessment process, assigning meaning to the school visit.

  • 28.
    Lindgren, Patric
    Linnaeus University, Faculty of Social Sciences, Department of Political Science.
    Småstat i brytningstid: Sveriges säkerhetspolitiska orientering efter tre världskonflikter under 1900-talet2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis aims to explain how small states, in this case Sweden, security politics adapts to new circumstances after great conflicts in the 20th century. The analytical model is built by a combination of the opposite theories of international politics, realism and idealism, combined with actor based and structure based perspectives and thus creating a four field analytical matrix.

    The empirical foundation constitutes of three post conflict periods; post-first world war, post-second world war and post-cold war periods. For every period three cases are analyzed; one foreign politics initiative, one association to an international organization and one defence politics decision. In the post-first world war period the focus is on the Swedish intervention of the Åland archipelago, the association to the League of Nations and disarmament decision in 1925. In the post-second world war period the focus is on the association of Sweden to the United Nations, the Swedish initiative to a Scandinavian defence alliance and the defence decision of 1948. In the post-cold war period the focus is on the Swedish association to the European Union, the Swedish participation in the NATO led IFOR operation in Bosnia and the defence decision in 1996.

    The main conclusions of these investigations are that small states, like Sweden, both are restricted in their foreign and security politics by international structures and able to use the same structure to promote their interests. Time is a key element for analyzing both structural and actor based aspects of a small states capacity. Also, in the case of Sweden, there tends to be a tension between an idealistic dominated politics and a realistic dominated politics when it comes to foreign and security politics, and that idealism seems to have increased in the latter period.

  • 29.
    Johansson, Maria C.
    Linnaeus University, Faculty of Social Sciences, Department of Education and Teacher's Practice.
    The institutionalisation of validation and the transformation of vocational knowledge: The case of admission into Vocational Teacher Education in Sweden2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The aim of this thesis was to understand the validation of vocational knowledge prior to entry into vocational teacher education in Sweden with regard to conceptions and understandings of vocational knowledge, and also to understand how institutional conditions, such as ideas of how to organise validation, influence the content and form of the validation practice. From this aim the following research questions were developed: What ideas about the organisation of validation stand out in the policy and practice of validation? What conceptions and understandings of vocational knowledge is the organisation of validation built on and what do they entail? Who has the agency to describe and decide upon vocational knowledge in the policy and practice of validation? What institutional arrangements appear in the practice of validation?

    To conduct the studies in the thesis a multimethods approach was adopted, combining policy analysis and interviews. For theoretical support, new institutional theories were used and also theories of knowledge. The results revealed that the regulative elements of validation have transformed vocational knowledge to fit a frame similar to formal education. In terms of norms and values, it appears as if validation is more of a social and economic project than one of accounting for vocational knowledge and vocational pride. Cultural/cognitive matters that are taken for granted when considering vocational knowledge differ quite significantly between agents involved in validation. Validation of vocational knowledge exhibits a conceptual confusion having different conceptions of knowledge simultaneously at play. This confusion blurs the boundaries between concepts of knowledge, learning, and the learning context. In the complexity of ideas of how to organise validation and different knowledge conceptions, institutional arrangements appear to be based on a sense of belonging, either to academia or to the trade. The agency of those with vocational knowledge is limited in several ways within validation.

  • 30.
    Roos, Helena
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    The meaning(s) of inclusion in mathematics in student talk: Inclusion as a topic when students talk about learning and teaching in mathematics2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis contributes to research and practice within the field of special education in mathematics with more knowledge about, and an understanding of, students´ meaning(s) of inclusion in mathematics education. Three research questions guide the study: What meaning(s) is/are ascribed, and how is inclusion used, in mathematics education research? What meaning(s) do the students ascribe to inclusion in mathematics learning and teaching? And what frames students´ meaning(s) of inclusion in mathematics learning and teaching?The first part of this study began with a systematic literature review on the notion of inclusion in mathematics education research, and the search resulted in 1,296 research studies. Of these, 76 studies were retained after the criteria for time span and peer-reviewed research were applied and 19 duplicates had been removed. The second part of the study involves a case study of three students and their meaning(s) of inclusion in mathematics education. The selected school was a lower secondary school in an urban area of Sweden. The school had set out to work inclusively, meaning their aims were to include all students in the ordinary classroom teaching in every subject and to incorporate special education into the ordinary teaching with no fixed special education groups. Three students were chosen for this part of the study: one in Grade 7 and two in Grade 8. Edward, one of the students in Grade 8, was chosen because he was thought to be a student in access to mathematics education. The other two students were chosen because they were thought to be struggling to gain access to mathematics education: Veronica in Grade 7 and Ronaldo in Grade 8 (the same class as Edward). In this study, the object of the study is the meaning(s) of inclusion in student talk. This study is an instrumental and collective case (Stake, 1995), as it involves several students’ meaning(s) aimed at developing a more general understanding of inclusion in mathematics education. The case is also an information-rich case (Patton, 2002), with contributions from students in mathematics education at an inclusive school. Applying Flyvbjerg’s (2006; 2011) notions, one can also call this kind of selection “information-oriented”, and the case is an extreme one – a choice made in order to get “a best case scenario”. An extreme case is a case used to “obtain information on unusual cases  which can be especially problematic or especially good in a more closely defined sense” (Flyvbjerg, 2011, p. 307). The data in this study consists of both observations and interviews conducted during the spring semester 2016. The observations took place in a Grade 7 and Grade 8 classroom at the same school where the interviewed students were enrolled. At least one mathematics lesson each month for each class was observed, and student interviews followed each observation. The observations were used to provide a context for the interviews and to support the analysis. In this study, discourse analysis (DA) as described by Gee (2014a; 2014b) was chosen as both the theoretical frame and as an analytical tool because of its explanatory view on discourse, with description foregrounded. With the help of DA, this study describes both the meaning(s) and the use of the notion of inclusion in mathematics education research. It also describes students’ meaning(s) of inclusion in mathematics education as well as framing issues in student talk of inclusion in mathematics education. From Gee´s point of view, DA encompasses all forms of interaction, both spoken and written, and he provides a toolkit for analysing such interaction by posing questions to the text. Gee distinguishes two theoretical notions, big and small discourses, henceforth referred to as Discourse (D) and discourse (d). Discourse represents a wider context, both social and political, and is constructed upon ways of saying, doing, and being: “If you put language, action, interaction, values, beliefs, symbols, objects, tools, and places together in such a way that other recognize you as a particular type of who (identity) engaged in a particular type of what (activity), here and now, then you have pulled of a Discourse” (Gee, 2014 a, p. 52, Gee’s italics). When looking at discourse (with a small d), it focuses on language in use – the “stretches of language” we can see in the conversations we investigate (Gee, 2014a, 2014b), meaning the relations between words and sentences and how these relations visualize the themes within the conversations. These small discourses can inform on how the language is used, what typical words and themes are visible, and how the speakers or writers design the language. According to Gee (2015), big Discourse sets a larger context for the analysis of small discourse. The results of the first part of the study answer to the research question, What meaning(s) is ascribed, and how is inclusion used in mathematics education research? They show that research on inclusion in mathematics education use the term inclusion when both referring to an ideology and a way of teaching, although these two uses are usually treated separately and independently of each other. The results of the second part of the study answer to the following research questions: What meaning(s) do the students ascribe to inclusion in mathematics learning and teaching? And what frames students´ meaning(s) of inclusion in mathematics learning and teaching? These questions show how meaning(s) of inclusion in student talk can be described by three overarching Discourses: the Discourse of mathematics classroom setting, of assessment, and of accessibility in mathematics education. Within these Discourses, smaller discourses make issues of meanings of inclusion for the students visible in terms of: testing, grades, tasks, the importance of the teacher, (not) being valued, the dislike of mathematics, the classroom organization, and being in a small group. This study shows the complexities and challenges of teaching mathematics, all while simultaneously handling students’ diversity and promoting the mathematical development of each student. To enhance students’ participation and access demands that the teacher knows her or his students, is flexible, has a pedagogical stance and tactfulness, and is knowledgeable in mathematics and mathematics education. It also demands that the teacher is able to take a critical stance and resist the prevailing discourse of assessment that can sometimes overshadow the mathematics education, and in a sense, almost become mathematics for the students. Furthermore, this study also shows how complex and challenging it is to be a mathematics student: they are required to relate to, understand, and participate in many Discourses existing at the same time in a single mathematics classroom. These Discourses interrelate and are embedded in power relations between students and teachers and institutions. This demands that the students are alert and able to use various symbols and objects as well as recognize patterns, and then act accordingly. Hence, to be able to fully participate, you have to be able to talk the talk and walk the walk (Gee, 2014a). This means that not only do you have to use the language correctly, but also you have to act properly at the right time and place.

  • 31.
    Engström, Robin
    Linnaeus University, Faculty of Arts and Humanities, Department of Languages.
    The Scottish Independence Referendum in Text, Image and Thought2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In 2014, a referendum was held in Scotland in order to decide the country’s constitutional future. The referendum was the climax of years of campaigning that gave rise to a rich body of political discourse. This compilation thesis attempts to show how an independent Scotland was discursively constructed, and how these constructions impacted on Scottish identity. The thesis consists of four original research papers which employ a number of complementary approaches in order to analyse a rich and diverse data set.

    The first article examines how the Scottish government looked at small European states in order to construct a vision of a future independent Scotland. This was achieved by discursively constructing small states as economically successful and democratically progressive and then by emphasizing Scotland’s role as a small country.

    The second article analyses the many new metaphorical personifications of Scotland, notably as a woman, that appeared during the campaign. The article finds that traditional, gendered metaphors were largely reworked in order to function in a modern political context.

    The third article maps the central topics and the ideological morphology of discourses on Scottish independence produced by the Scottish National Party and the intellectual and artistic movement National Collective. Unlike previous research, the results of the analysis suggest that these organizations as complementary but labels the former politically nationalist and the latter culturally nationalist.

    The fourth article analyses image tweets published by the official Yes and No campaigns in order to ascertain how the two campaigns legitimated their own standpoints and how they delegitimated their opponents online. The analysis finds that the Yes campaign balanced between promoting its own visions whilst criticizing their opponents, in contrast to the No campaign which almost entirely focused on delegitimating its opponents, thus failing to offer alternative visions.

    Collectively, the thesis paints a picture of a diverse independence movement with different aims and different rationales for advocating independence. Besides making a contribution to the literature on nationalism in general and Scottish nationalism in particular, the thesis further integrates the fields of political theory and discourse studies.

  • 32.
    Fridolfsson, Emil
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Thiamin (vitamin B1) in the aquatic food web2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Thiamin (vitamin B1) is required for several life-sustaining processes in most organisms and cells, e.g. in the conversion of food to energy. It also serves as an antioxidant and is important for proper nerve signaling. Thiamin is produced predominantly by bacteria and phytoplankton in the aquatic food web. Not all bacteria and phytoplankton, nor any organisms in higher trophic levels can produce thiamin; instead, they rely on a continuous external supply and uptake of this essential compound. Thiamin deficiencies occur episodically in a wide range of taxa, especially in higher trophic levels. In the Baltic Sea, thiamin deficiencies has been most pronounced in salmon (Salmo salar) and recently deficiencies are also reported for other fish species and birds.

    This thesis focuses on thiamin dynamics in lower trophic levels, covering primary producers as well as primary consumers, as this topic has not received much attention previously. Thiamin content of common phytoplankton and zooplankton species and the transfer between them was investigated in experiments and field studies. The relationship between thiamin deficiency and underlying environmental factors was also investigated using monitoring data.

    Thiamin content differed among phytoplankton classes, species and even strains. Filamentous Cyanophyceae had considerably higher thiamin content than other classes. However, thiamin transfer to copepods was lower, probably associated with difficulties ingesting the filaments. Moreover, thiamin content in seston varied seasonally, being highest during summer when both Prymnesiophyceae and filamentous Cyanophyceae were more abundant. Thiamin content in the two size fractions correlated strongly and was always higher in the smaller size fraction, illustrating the importance of picoplankton and bacteria in the food web. Also, seston thiamin content was higher in the Baltic Proper than in the Skagerrak. Copepods differed in thiamin content among genera, as well as between locations. Acartia sp. had the highest thiamin content and copepods from the Skagerrak had higher levels than congeners from the Baltic Sea. Thiamin deficiency syndromes in salmon was associated with changes in all trophic levels, as well as changes in several abiotic variables.

    In all, this thesis provides new insights on thiamin content and seasonal dynamics in various phytoplankton and zooplankton species, the transfer of this vitamin between trophic levels as well as the overall importance of thiamin in the aquatic food web.

  • 33.
    Hemmilä, Venla
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Towards low-emitting and sustainable particle and fibreboards: Formaldehyde emission test methods and adhesives from biorefinery lignins2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    High volumes, fast production speed, and low material costs have been historically the driving factors of the particle- and fibreboard industries. However, in recent years the fossil-fuel dependency and health issues of the formaldehyde-containing adhesives used in the production have gained attention from both legislators and consumers. The latest example of legislation development is the change that the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety of Germany  (Bundesministerium für Umwelt, Naturschutz und Nukleare Sicherheit) made to their testing method, effectively lowering the formaldehyde emission levels of wood-based panels in Germany from the European emission level of 0.1 ppm (E1, EN 717-1) to 0.05 ppm. As the emission levels of requirements decrease, market opportunities arise for formaldehyde-free bio-based adhesive systems. The aim of this thesis was thus to evaluate the different formaldehyde test methods at low emission levels (<0.05 ppm), and to explore new adhesive alternatives to the formaldehyde and petroleum-based systems used today.

    As formaldehyde emissions decrease, choosing the right measurement method becomes increasingly important. Repeatability and correlation between the main European and American formaldehyde measurement chambers, described in EN 717-1 and ASTM D 6007 standards respectively, were determined. In addition, an alternative fast factory method based on emissions was evaluated, and the effect of reducing the conditioning time before emission measurements was investigated. A literature research was conducted on different bio-based raw materials in order to review their potential, from both scientific and industrial viewpoints, as alternatives to the current petroleum-derived and formaldehyde-based adhesives. Lignin residues from biorefinery processes were chosen for further testing due to their increasing volumes and potential to suit various pathways for adhesive making. Three different biorefinery lignins were compared, and ammonium lignosulfonate was chosen for making adhesives for particleboards by using one petroleum-based and one bio-based crosslinker.

    The main conclusion of the formaldehyde emission part of the thesis was that formaldehyde emissions can be measured both accurately and quickly at low levels using chamber methods, even at factory environment. There was a good correlation between the American D 6007 and European EN 717-1 chamber methods at emission levels <0.05 ppm for both particleboards (r2 = 0.9167) and fibreboards (r2 = 0.9443). Further understanding on the effect of edge-sealing of boards and analytical methods described in the standards was obtained. It was confirmed that a fast chamber method with 1 day conditioning and 15 minutes measuring time could be used for factory formaldehyde control for most board types.

    The bio-based adhesives’ literature review revealed a large amount of studies on different sustainable adhesive systems, some of which seem promising. Both soy protein and tannin were found to be partially commercialized, with certain pre-requisites. Kraft-lignin was especially well researched, but was found to be difficult to use for other applications than partial replacement of phenol in phenol-formaldehyde (PF) adhesives due to poor water solubility and purity. Lignin residues from biorefinery processes were found to be a less studied, growing raw-material source with a lot of potential. Thus, supercritical water hydrolysis lignin (SCWH) and two biorefinery lignosulfonates were chemically and thermally characterized, and evaluated as raw materials for value-added applications, including adhesives. SCWH lignin was found to have more β-R linkages and lower amount of impurities than the lignosulfonates. High amount of phenolic hydroxyl groups indicated that SCWH would be well suited for phenol replacement in PF adhesives. The two lignosulfonates had more aliphatic hydroxyl groups, which can be interesting for other crosslinking reactions than PF. Ammonium lignosulfonate (ALS) was chosen for further evaluation as having slightly better properties than sodium lignosulfonate (SLS). ALS was combined with one bio-based crosslinker, furfuryl alcohol (FOH), and one synthetic crosslinker, 4,4’-diphenylmethane diisocyanate (pMDI), and tested as particleboard adhesive. Although in veneer tensile shear strength testing the crosslinkers worked equally well, pMDI provided significantly better results in particleboards. In addition, higher emissions than what can be expected from wood particles alone were detected from the particleboard samples crosslinked with FOH, even though FOH can be classified as non-formaldehyde added adhesive system. Further research is needed to elucidate how much the lignin contributes to the final adhesion strength when it is used together with pMDI.

    This thesis has provided new insights on formaldehyde emissions and bio-based adhesives towards healthier and more sustainable particle- and fibreboards. It has been proven that formaldehyde emissions can be measured accurately at emission levels of wood, enabling comparisons of formaldehyde-free systems. Formaldehyde-free adhesives based on a biorefinery lignin type and pMDI showed promising results for particleboards. However, these results need to be improved by different modifications of the lignin in order to bring the adhesive system to the economical and performance level required by the particleboard industry.

1 - 33 of 33
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf