Life cycle management of TVO nuclear power plant

Tämä diplomityö tutkii eri elinkaarihallinnan menetelmiä ja vertaa niitä TVO:n menetelmiin. Lisäksi TVO:n prosessin ongelmakohdat tunnistetaan ja niihin esitetään ratkaisuja. Vertailukohteina toimii ydinvoimateollisuuden lisäksi vesivoima, fossiiliset voimalaitokset sekä paperiteollisuus. Sähkön hinnan jatkaessa laskuaan on elinkaariajattelusta tullut ajankohtaista myös ydinvoimayhtiöille. Ydinvoimalaitoksien pitkän suunnitellun käyttöiän ansiosta laitoksen elinkaaren aikana voi tapahtua useita asioita, jotka vaikuttavat laitoksen investointitarpeisiin. Turvallisen sähköntuotannon varmistamiseksi eri laitososia on joko muokattava tai uusittava. Elinkaariajatteluun kuuluu tehokas laitoksen kunnon valvonta, laitoksen ikääntymiseen vaikuttavien ilmiöiden tunnistaminen, sekä ikääntymistä hillitsevien toimenpiteiden pitkän tähtäimen suunnittelu. Hyvällä ennakkosuunnittelulla pyritään varmistamaan se, että laitoksella voidaan tuottaa sähköä koko sen jäljellä olevan käyttöiän aikana. Kun tarpeiden tunnistus ja suunnittelu tehdään hyvissä ajoin mahdollistetaan myös investointien optimointi. Paras hyöty pyritään saamaan ajoittamalla oikeat investoinnit oikeaan aikaan.

A case study of the English language teachers’ attitudes toward use of information and communication technology (ICT) in Finland

This qualitative study was aimed at investigating foreign language teachers’ attitudes toward use of information and communication technology (ICT) in their instruction. The insight was gained through the reported experience of ICT implementation by teachers, in what way and for which purpose they refer to use of technology, what kind of support and training they are provided with, and what beliefs they express about the influence of ICT implementation. This case study took place in one of the training schools in Finland. Five teachers participated in semi-structured interviews through a face-to-face approach. The findings demonstrated positive attitudes of teachers toward integration of ICT. The teachers shared their opinions about positive influence that ICT implementation has on both teaching and learning processes. However, they also pointed out the negative sides of ICT use: distraction of the students from usage of technology and technical problems causing frustration to the teachers. In addition, the responses revealed that the teachers are provided with adequate training aimed at enhancing their qualification which is provided with well-timed technology support and colleagues’ collaboration facilitating an efficient and smooth pace of the teaching process. According to the teachers’ opinions ICT integration in education appeared to have changed the role of the teacher. Due to different alterations in the field of ICT development teachers are required to upgrade their skills. The paper concludes with the limitations of the study and the recommendations for conducting further research.

Wood-derived biomaterials for biomedical applications

Driven by the global trend in the sustainable economy development and environmental concerns, the exploring of plant-derived biomaterials or biocomposites for potential biomedical and/or pharmaceutical applications has received tremendous attention. Therefore, the work of this thesis is dedicated to high-value and high-efficiency utilization of plant-derived materials, with the focus on cellulose and hemicelluloses in the field of biomedical applications in a novel biorefinery concept. The residual cellulose of wood processing waste, sawdust, was converted into cellulose nanofibrils (CNFs) with tunable surface charge density and geometric size through 2,2,6,6-tetramethylpiperidinyloxy (TEMPO)-mediated oxidation and mechanical defibrillation. The sawdust-based CNFs and its resultant free-standing films showed comparable or even better mechanical properties than those from a commercial bleached kraft pulp at the same condition, demonstrating the feasibility of producing CNFs and films thereof with outstanding mechanical properties from birch sawdust by a process incorporated into a novel biorefinery platform recovering also polymeric hemicelluloses for other applications. Thus, it is providing an efficient route to upgrade sawdust waste to valuable products. The surface charge density and geometric size of the CNFs were found to play key roles in the stability of the CNF suspension, as well as the gelling properties, swelling behavior, mechanical stiffness, morphology and microscopic structural properties, and biocompatibility of CNF-based materials (i.e. films, hydrogels, and aerogels). The CNFs with tunable surface chemistry and geometric size was found promising applications as transparent and tough barrier materials or as reinforcing additive for production of biocomposites. The CNFs was also applied as structural matrices for the preparation of biocomposites possessing electrical conductivity and antimicrobial activity by in situ polymerization and coating of polypyrrole, and incorporation of silver nanoparticles, which make the material possible for potential wound healing application. The CNF-based matrices (films, hydrogels, and aerogels) with tunable structural and mechanical properties and biocompatibility were further prepared towards an application as 3D scaffolds in tissue engineering. The structural and mechanical strength of the CNF matrices could be tuned by controlling the charge density of the nanocellulose, as well as the pH and temperature values of the hydrogel formation conditions. Biological tests revealed that the CNF scaffolds could promote the survival and proliferation of tumor cells, and enhance the transfection of exogenous DNA into the cells, suggesting the usefulness of the CNF-based 3D matrices in supporting crucial cellular processes during cell growth and proliferation. The CNFs was applied as host materials to incorporate biomolecules for further biomedical application. For example, to investigate how the biocompatibility of a scaffold is influenced by its mechanical and structural properties, these properties of CNF-based composite matrices were controlled by incorporation of different hemicelluloses (O-acetyl galactoglucomanan (GGM), xyloglucan (XG), and xylan) into CNF hydrogel networks in different ratios and using two different approaches. The charge density of the CNFs, the incorporated hemicellulose type and amount, and the swelling time of the hydrogels were found to affect the pore structure, the mechanical strength, and thus the cells growth in the composite hydrogel scaffolds. The mechanical properties of the composite hydrogels were found to have an influence on the cell viability during the wound healing relevant 3T3 fibroblast cell culture. The thusprepared CNF composite hydrogels may work as promising scaffolds in wound healing application to provide supporting networks and to promote cells adhesion, growth, and proliferation.

A case study of the English language teachers’ attitudes toward use of information and communication technology (ICT) in Finland

This qualitative study was aimed at investigating foreign language teachers’ attitudes toward use of information and communication technology (ICT) in their instruction. The insight was gained through the reported experience of ICT implementation by teachers, in what way and for which purpose they refer to use of technology, what kind of support and training they are provided with, and what beliefs they express about the influence of ICT implementation. This case study took place in one of the training schools in Finland. Five teachers participated in semi-structured interviews through a face-to-face approach. The findings demonstrated positive attitudes of teachers toward integration of ICT. The teachers shared their opinions about positive influence that ICT implementation has on both teaching and learning processes. However, they also pointed out the negative sides of ICT use: distraction of the students from usage of technology and technical problems causing frustration to the teachers. In addition, the responses revealed that the teachers are provided with adequate training aimed at enhancing their qualification which is provided with well-timed technology support and colleagues’ collaboration facilitating an efficient and smooth pace of the teaching process. According to the teachers’ opinions ICT integration in education appeared to have changed the role of the teacher. Due to different alterations in the field of ICT development teachers are required to upgrade their skills. The paper concludes with the limitations of the study and the recommendations for conducting further research.