| 1. |
- Holmgren, Carina A., 1961-
(författare)
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Formandet av den entreprenöriella läraren : Entreprenöriellt lärande som styrningsteknologi
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this thesis is to, from a governing perspective, describe and enhance the understanding of the form entrepreneurial learning takes in lower and upper secondary schools’ practice, and its effects in terms of which approaches and practices are strengthened and marginalized. The context of this thesis is the industrial policy work to implement entrepreneurship in the Swedish educational system in 1996–2009. Industrial policy with its objectives concerning more companies and an entrepreneurial citizen is pervaded by expectations of the impacts of entrepreneurship. Discussing entrepreneurial learning as a governing technology, based on Rose's development of Foucault's concept governmentality, provides a distance from these expectations and put productive power and complexity into focus. The governing perspective allows for the visualization of how an educational concept in entrepreneurial learning contributes to hierarchies of what is considered valuable but also how the fostering of the entrepreneurial citizen is made possible.I have followed three regional projects aimed at supporting teachers to implement entrepreneurship in their teaching practice. The analysed material includes observations of teacher training in entrepreneurial learning, interviews with participating teachers and principals, as well as project documents, policy documents and entrepreneurship research.This thesis contributes to 'governing research' which use governmentality to understand entrepreneurship related to education. I show how entrepreneurial learning affects teachers’ subjectivities, how they should be and act, through the production of the entrepreneurial teacher, and what ways to be as a teacher this governing technology marginalizes. I also show how an educational concept in entrepreneurial learning enables governing at a distance by creating links between policy, entrepreneurship research, and teachers. These links contribute to teachers embracing entrepreneurial learning, and thus engaging in the fostering of the entrepreneurial citizen. By making visible the complexity of the entrepreneurial teacher and show the three subjectivities this ‘teacher’ offers: the collaborating, the flexible and the individual forming teacher, and the teachers marginalized: the supporting teacher and the autonomous subject teacher, this thesis contributes to a language to talk about how teachers are governed through entrepreneurial learning and its effects.
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| 2. |
- Lidman, Johan, 1988-
(författare)
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Metals take flight : Transport and effects across ecosystems
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Metal contamination can have severe toxic effects in the ecosystems, resulting in loss of biodiversity, reduced abundance of organisms, and loss of ecosystem services. Traditionally, aquatic ecosystems have been regarded as a sink of metal contamination. However, lakes could also act as a source, as metals can be transported by emerging aquatic insects from the aquatic to the terrestrial ecosystem. The consequence of this transport for terrestrial organisms has previously gained little focus. In this thesis, I study metal contamination transport and toxic effects on metal exposed aquatic invertebrates and the terrestrial insectivorous bird, pied flycatcher (Ficedula hypoleuca), in aquatic and terrestrial environments contaminated by metals from a closed lead (Pb) and zinc (Zn) mine. Studied lakes adjacent to the mine all displayed elevated metal concentrations from the start of the mining operation, but with different temporal and spatial patterns with lakes used as part of the mining activity even more affected. Factors affecting metal toxicity, such as organic matter concentration in lakes, varied during the mining and post-mining period, indicating fluctuating toxicity despite similar metal concentrations. The contamination level and toxicity risk are still high 15 years after closure of the mine, but ecosystems are starting to recover. Despite high metal concentrations in lake water and sediment, no effect on invertebrate abundance or composition of aquatic invertebrates was observed. However, when focusing on metamorphosis, proportionally fewer insects emerged from more contaminated lakes. In contrast, in lab mesocosm was no effect on metamorphosis observed of non-biting midges (Chironomus riparus), although larval survival decreased, and emergence was delayed at higher metal concentrations in sediments. Emerging adult insects transported a significant amount of metals to terrestrial ecosystems, observed both in the lab and in the field. Emerging aquatic insect and ants were major dietary metal exposure routes for pied flycatcher’s nestlings. Thus, aquatic-derived metals can influence terrestrial consumers, especially in riparian zones of contaminated lakes where availability of aquatic insects is high. Increasing accumulation of Pb has been observed to reduce hemoglobin (Hb) levels in birds. Despite elevated Pb concentrations in nestling blood in contaminated environments, nestling Hb levels, used also as indicator of nestling health, was more affected by availability of different prey than Pb levels in the blood, where availability of aquatic insects and aerial terrestrial insect had positive impact on nestling health. Overall, this thesis show that metal contamination of aquatic ecosystems also influences terrestrial organisms by decreasing their food availability and increasing metal exposure via diets. Thus, potential effects on terrestrial systems should to larger extent be included when studying aquatic contaminants. Further, indirect effects and metal bioavailability could alter the toxic effects on metal-exposed organism and should be included to accurately estimate direct toxic effects.
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| 3. |
- Sehaqui, Houssine, 1981-
(författare)
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Nanofiber networks, aerogels and biocomposites based on nanofibrillated cellulose from wood
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nanofibrillated cellulose (NFC) from wood is an interesting material constituent of high strength and high aspect ratio, which easily forms networks through interfibril secondary bonding including hydrogen bonds. This has been exploited in preparation of new materials, which extend the range of properties for existing cellulosic materials. The objective is to explore processing-structure and structure-property relationships in NFC materials. Dense networks of NFC, referred to as “nanopaper” having a random-in-the-plane orientation of the fibrils have been successfully prepared by a papermaking-like process involving vacuum filtration and water evaporation using laboratory papermaking equipment. Large, flat and transparent nanopaper sheets have thus been prepared in a relatively short time. Using the same preparation route, NFC was used to reinforce pulped wood fibers in dense network structures. NFC networks formed in the pore space of the wood fiber network give an interesting hierarchical structure of reduced porosity. These NFC/wood fiber biocomposites have greater strength, greater stiffness and greater strain-to-failure than reference networks of wood fibers only. In particular, the work to fracture (area under the stress-strain curve) is doubled with an NFC content of only 2%. The papermaking preparation route was extended to prepare nanocomposites of high NFC content with a cellulose derivative matrix (hydroxyethyl cellulose, HEC) strongly associated to the NFC. Little HEC was lost during filtration. The NFC/HEC composites have high work to fracture, higher than that of any reported cellulose composite. This is related to NFC network characteristics, and HEC properties and its nanoscale distribution and association with NFC. Higher porosity NFC nanopaper networks of high specific surface area were prepared by new routes including supercritical drying, tert-butanol freeze-drying and CO2 evaporation. Light-weight porous nanopaper materials resulted with mechanical properties similar to thermoplastics but with a much lower density and a specific surface area of up to 480 m2/g. Freeze-drying of hydrocolloidal NFC dispersions was used to prepare ultra-high porosity foam structures. The NFC foams have a cellular foam structure of mixed open/closed cells and “nanopaper” cell wall. Control of density and mechanical properties was possible by variation of NFC concentration in the dispersion. A cellulose I foam of the highest porosity ever reported (99.5%) was prepared. The NFC foams have high ductility and toughness and may be of interest for applications involving mechanical energy absorption. Freeze-drying of NFC suspended in tert-butanol gave highly porous NFC network aerogels with a large surface area. The mechanical behavior was significantly different from NFC foams of similar density due to differences in deformation mechanisms for NFC nanofiber networks.
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| 4. |
- Svagan, Anna, 1979-
(författare)
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Bio-inspired cellulose nanocomposites and foams based on starch matrix
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In 2007 the production of expanded polystyrene (EPS) in the world was over 4 million tonnes and is expected to grow at 6 percent per year. With the increased concern about environmental protection, alternative biodegradable materials from renewable resources are of interest. The present doctoral thesis work successfully demonstrates that starch-based foams with mechanical properties similar to EPS can be obtained by reinforcing the cell-walls in the foams with cellulose nanofibers (MFC). High cellulose nanofiber content nanocomposites with a highly plasticized (50/50) glycerol-amylopectin starch matrix are successfully prepared by solvent-casting due to the high compatibility between starch and MFC. At 70 wt% MFC, the nanocomposites show a remarkable combination of high tensile strength, modulus and strain to failure, and consequently very high work to fracture. The interesting combination of properties are due to good dispersion of nanofibers, the MFC network, nanofiber and matrix properties and favorable nanofiber-matrix interaction. The moisture sorption kinetics (30% RH) in glycerol plasticized and pure amylopectin film reinforced with cellulose nanofibers must be modeled using a moisture concentration-dependent diffusivity in most cases. The presence of cellulose nanofibers has a strong reducing effect on the moisture diffusivity. The decrease in zero-concentration diffusivity with increasing nanofiber content could be due to geometrical impedance, strong starch-MFC molecular interaction and constrained swelling due to the cellulose nanofiber network present. Novel biomimetic starch-based nanocomposite foams with MFC contents up to 40 wt% are successfully prepared by freeze-drying. The hierarchically structured nanocomposite foams show significant increase in mechanical properties in compression compared to neat starch foam. Still, better control of the cell structure could further improve the mechanical properties. The effect of cell wall composition, freeze-drying temperature and freezing temperature on the resulting cell structure are therefore investigated. The freeze-drying temperature is critical in order to avoid cell structure collapse. By changing the starch content, the cell size, anisotropy ratio and ratio between open and closed cells can be altered. A decrease in freezing temperature decreases the cell size and increases the anisotropy ratio. Finally, mechanical properties obtained in compression for a 30 wt% MFC foam prepared by freeze-drying demonstrates comparable properties (Young's modulus and yield strength) to expanded polystyrene at 50% RH and similar relative density. This is due to the reinforcing cellulose nanofiber network within the cell walls.
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| 5. |
- Åström, Linda A.
(författare)
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Gatekeepers of democracy? : a comparative study of elite support for democracy in Russia and the Baltic States
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study deals with the consolidation of democracy in general and with political support for democracy, in particular. The theoretical reason for observing support for democracy rests on the assumption that this kind of support is a vital factor that will foster (or its absence will obstruct) the development of democracy in the countries analysed in this study, i.e. Russia, Estonia, Latvia, and Lithuania. A democratic regime cannot be sustained without legitimacy or popular and/or elite support. The aim of this study is to map and compare political support among local elites in five regions in Russia, using eight regions in the Baltic states as points of references. The major theoretical point of departure is David Easton's identification of three objects of support, namely, the political community, the regime and the authorities. The local elites (political, administrative, civil society, and economic) were surveyed in 1999 and 2000. The analyses show that the elites in Russia, Estonia, Latvia, and Lithuania generally support the political community, the first object of support in the theoretical model. There are varying degrees of support among the elites for regime values and principles, norms and the regime structure, which constitute the second object of support. And finally, only the Estonian elites could be said to have some support for the authorities, the third object of support. The study also illustrates that support is a multidimensional phenomenon, and the respondents differentiate between diffuse and specific support.
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