Raaka-aine- ja energiatehokkuuden parantaminen Oras Oy:n valimossa

Tämän diplomityön tavoitteena oli tutkia toimintatapoja ja edellytyksiä parantaa Oras Oy:n valimon raaka-aine- ja energiatehokkuutta. Tarkastelu suoritettiin ekotehokkuusajattelun näkökulmasta. Valimon ekotehokkuutta mitattiin metallin saannon sekä valu-uunien energiatehokkuuden avulla. Tutkimustyö suoritettiin valitsemalla tarkastelun kohteeksi 20 valutuotetta. Metallin saantoa selvitettäessä punnittiin tuotteita eri työvaiheissa,jolloin saatiin selville valukanavien sekä koneistus- ja hiontavarojen osuudet valutuotteisiin panostetusta messingistä. Saantoa laskettaessa tuli myös huomioida vuosittain hylättävien tuotteiden määrät sekä messingin raaka-ainekierto kokonaisuudessaan. Valu-uunien osalta selvitettiin toiminta-ajan ja energiankulutuksen jakautuminen messingin sulattamisen ja sulan kuumanapidon kesken. Työssä tarkasteltiin, kuinka paljon metallin saantoa voitaisiin parantaa pienentämällä valukanavien ja työvarojen osuutta valoksissa sekä vähentämällähylkyjen määrää. Lisäksi tarkasteltiin muutosten vaikutuksia raaka-ainekustannuksiin sekä jätteiden määrään. Valu-uunien energiatehokkuuden parantamisen osaltatarkasteltiin käyttöasteen nostamisen eli viikoittaisen käyntiajan lisäämisen vaikutuksia energiankulutukseen ja -kustannuksiin sekä edellytyksiä pitää osa uuneista kylmänä.

Side peaks in Nb and NbTi point-contact spectra

Superconductor – normal metal point contacts were investigated, using different combinations of Cu, brass, Nb and NbTi. The resulting spectra contained side peaks. The currents at which these side peaks appeared, depended on the radii of the contacts. For contacts with Nb this dependence was quadratic, while for contacts with NbTi it was linear. Based on this, we argue that the side peaks in the case of the Nb contacts are due to the critical current density being exceeded. In contrast, side peaks of the NbTi contacts are caused by the self-magnetic field exceeding the lower critical field of NbTi. The NbTi contacts did not show the expected contribution from the vanishing Maxwell resistance of the superconductor, a question which remained open.

Det planlagda och det som visar sig : klasslärarstuderandes syn på undervisning i teknisk slöjd

Sloyd as an activity concretizes man’s ability to, with the help of mind and body, reshape materials into objects and change her conditions for survival. The sloyd actor outside school works when the spirit moves her, while the pupil in school is expected to sloyd regardless of motivation. Subject teachers become experts on sloyd in educational settings, while the qualification requirements may set the class teachers’ voluntariness within parenthesis. All class teachers qualify to teach all core subjects of the national curriculum in Finland from preschool to grade six. The aim of the current thesis is to deepen the knowledge on how the science of sloyd education can support class teacher students’ future teaching in sloyd. In the empirical part of the study, Swedish-speaking Finnish class teacher students’ views on technical sloyd as one of their future subjects for teaching are examined. The class teacher’s qualifying skills in teaching technical sloyd are expected to take shape during only a few ECTS study points. The teacher students’ experience of the subject from the pupil’s perspective is supposed to move into a budding teacher subject. In a research-based teacher education, self-reflection and reflection as a dialogue are extended aided by research results. Intuitive thinking interplays with rational thinking during this time. The teacher student’s approach to make use of the autonomous free space in teaching is, in the current thesis, as considerations where the individual weighs the pros and cons in relation to various phenomena in sloyd and the school overall. The basis for an individual autonomy is shaped and is expected to interplay on the common arena of autonomy. In the exercise of their profession, the class teacher teaching sloyd is expected to oscillate between the sloyd educational practice and theory. The first step in this movement within the teacher education is the coverage of a selection of theories during the studies. The empirical part of the study is carried out at two separate occasions with directed open-ended interviews with fifteen class teacher students in the beginning and end of their first year of study. The data was analysed with a hermeneutic approach and a qualitatively oriented approach to content analysis. The results are mirrored against theory within the science of sloyd education. The results show that class teacher students have a versatile view of educational sloyd. The overall results overthrow parts of the researcher’s pre-understanding. The viewpoint of the students seems to broaden from a merely manual activity to seeing sloyd as an educational activity. In order for the results to gain significance in the teacher education of the future, a line of reasoning is conducted in order to recommend an extended dialogue and thirteen possible themes for enriching discussions are put forth as a result of the present study. The extended dialogue focuses on that teacher education should make conscious ventures to create opportunities for the students to take part in effective discussions on the subject of sloyd, complementing the existing dialogue between the teacher educator and the students. This thesis lends support to reflections on the following aspects of educational sloyd in these dialogues: the reasons for why the sloyd subject exists, the ambitions of the subject, the content and organization of the subject for students as well as for the teacher educators.