Värdefull litteratur : Fyra gymnasielärare om samhällsuppdragets etik i förhållande till litteraturen i klassrummet

The ethical aspects of the Swedish Curriculum for the non-compulsory school system, Lpf94, will form the basis of the research in this essay. The ethical aspects constitute fundamental values and goals as well as common tasks that must be carried out by every teacher. Since the school debate focuses a lot on this perspective, which is often mentioned together with the words problematic and contradictory, it will consequently also be the focus of this essay. Here these features are treated in relation to literature in all its forms used by teachers in class, which also represents a part of the school debate. Together ethics and literature form a perspective that lacks research. The goal is to investigate the ethical awareness of teachers in relation to the literature, and find out which ethical decisions are made by teachers and in what ways the ethical aspects of the curriculum is fulfilled. A qualitative method has been used in order to gain results: four upper secondary school teachers/senior high school teachers have been interviewed. The results are presented in interview transcripts which have been analyzed and interpreted in the light of recent studies and research and pedagogical-didactical literature. Accordingly I have been able to draw the conclusions that the ethical features in teaching is not explicit and that there seldom seems to be any conscious ethical reflections in relation to the literature. The ethical aspects are rather invisible and unconscious. However, it is clear that the interviews raise the awareness of the ethical perspective and thus emphasize the growing and developing function of the dialogue. Finally the results have been interpreted from the point of view of the ethical tasks of the teacher in order to make the ethics visible.I detta examensarbete ligger fokus på de etiska aspekterna av samhällsuppdraget i förhållande till den litteratur som lärare använder sig av i klassrumsundervisningen. Eftersom en stor del av skoldebatten handlar om samhällsuppdraget och dess värdegrund utgör också detta perspektiv utgångspunkten för denna undersökning. Målet är att undersöka vilka etiska avvägningar lärare gör i valet av litteratur och på vilket sätt samhällsuppdragets etik blir synlig i lärares arbete. Därmed framkommer också till viss del i vilken omfattning värdegrundsarbetet sker. Genom en kvalitativ undersökningsmetod i form av samtal har fyra gymnasielärare intervjuats. Erhållna resultat har presenterats i form av intervjutranskript som analyserats och tolkats med hjälp av aktuell forskning och pedagogisk-didaktisk litteratur. De slutsatser som kan dras utifrån resultaten är att etiken i lärarnas arbete inte är explicit och att det oftast inte finns en medveten etisk reflektion utifrån litteraturen. Etiken är snarare osynlig och tämligen omedveten. Dock medvetandegörs den under samtalen vilket framhåller dialogens betydelse för utveckling. Vidare framkommer att etiken aldrig är ett mål i sig, utan fungerar mer som medel för att nå andra mål i klassrummet. Slutligen, för att synliggöra etiken, har resultaten tolkats utifrån de etiska krav i samhällsuppdraget som ställs på lärare.

Characterization of residential chimney conditions for flue gas flow measurements

A literature survey and a theoretical study were performed to characterize residential chimney conditions for flue gas flow measurements. The focus is on Pitot-static probes to give sufficient basis for the development and calibration of a velocity pressure averaging probe suitable for the continuous dynamic (i.e. non steady state) measurement of the low flow velocities present in residential chimneys. The flow conditions do not meet the requirements set in ISO 10780 and ISO 3966 for Pitot-static probe measurements, and the methods and their uncertainties are not valid. The flow velocities in residential chimneys from a heating boiler under normal operating condi-tions are shown to be so low that they in some conditions result in voiding the assumptions of non-viscous fluid justifying the use of the quadratic Bernoulli equation. A non-linear Reynolds number dependent calibration coefficient that is correcting for the viscous effects is needed to avoid significant measurement errors. The wide range of flow velocity during normal boiler operation also results in the flow type changing from laminar, across the laminar to turbulent transition region, to fully turbulent flow, resulting in significant changes of the velocity profile during dynamic measurements. In addition, the short duct lengths (and changes of flow direction and duct shape) used in practice are shown to result in that the measurements are done in the hydrodynamic entrance region where the flow velocity profiles most likely are neither symmetrical nor fully developed. A measurement method insensitive to velocity profile changes is thus needed, if the flow velocity profile cannot otherwise be determined or predicted with reasonable accuracy for the whole measurement range. Because of particulate matter and condensing fluids in the flue gas it is beneficial if the probe can be constructed so that it can easily be taken out for cleaning, and equipped with a locking mechanism to always ensure the same alignment in the duct without affecting the calibration. The literature implies that there may be a significant time lag in the measurements of low flow rates due to viscous effects in the internal impact pressure passages of Pitot probes, and the significance in the discussed application should be studied experimentally. The measured differential pressures from Pitot-static probes in residential chimney flows are so low that the calibration and given uncertainties of commercially available pressure transducers are not adequate. The pressure transducers should be calibrated specifically for the application, preferably in combination with the probe, and the significance of all different error sources should be investigated carefully. Care should be taken also with the temperature measurement, e.g. with averaging of several sensors, as significant temperature gradients may be present in flue gas ducts.