In this study simultaneously developing single phase, laminar and incompressible flow in a micro gap between parallel plates is numerically analyzed by including the effect of variation in thermal conductivity and viscosity with temperature. Variable property solutions for continuity, momentum and energy equations are performed in a coupled manner, for air as a Newtonian fluid. In these analyses the rarefaction effect, which is important for the slip flow regime, is taken into account by imposing slip velocity and temperature jump boundary conditions to the wall boundaries. Mainly, the influence of viscous dissipation, axial conduction, geometric parameters and rarefaction on the property variation effect is aimed to be discussed in detail. Therefore, the effects of variable thermal conductivity and viscosity are investigated simultaneously with the effects of rarefaction, geometric parameters, viscous dissipation and axial conduction. The difference between constant and variable solutions in terms of heat transfer characteristics is related to the effects of viscous dissipation axial conduction and rarefaction. According to results, property variation is substantially effective in the entrance region where temperature and velocity gradients are high. On the other hand, property variation effects are not significant for fully developed air flows in microchannel.

<p> </p><p>Syftet med denna kvalitativa studie, utifrån en fenomenografisk ansats, var att beskriva lärares uppfattningar av vad elevers tilltro till eget tänkande och egen förmåga att lära matematik innebär och hur de gör för att främja detta. Datainsamlingen bestod av intervjuer med lärare från förskoleklass till och med år sex.</p><p>Lärares uppfattningar beskrevs i att eleven visar lust, mod, stolthet och ansvar, särskilt när eleven vågat ta sig igenom en utmaning som den först inte trott sig klara. En förutsättning för tilltro var ett tryggt gruppklimat.</p><p>I främjandet av tilltro tog lärarna utgångspunkt i elevers erfarenheter med positiva förväntningar på eleverna i en lustfylld och kommunikativ undervisning. Uppmuntran och utmaningar på adekvat nivå, som skapar förståelse är kännetecknande för att eleven ska känna att den lyckas.</p><p>Det omgivande samhället har stor betydelse för elevers tilltro. Lärarens engagemang, nyfikenhet och uppmärksamhet på elevers tillägnade kunskaper för att erövra nytt matematiskt kunnande var av vikt för tilltron. Det framkom att eleverna bör uppmärksammas på att matematiska kunskaper och beräkningar ligger bakom de produkter som finns i vår omgivning.</p><p> </p> / <p> </p><p>The purpose of this qualitative study, based on a phenomenographical approach, was to describe teachers' perceptions of what the students' confidence in their own thinking and their own ability to teach mathematics and how they are doing to promote this. Data collection consisted of interviews with teachers from pre until year six.</p><p>Teacher perceptions were described in the student show desire, courage, pride and responsibility, especially when they dared to get through a challenge as the first not thought to cope. A prerequisite for faith was a safe group environment.</p><p>The promotion of confidence took the teachers based on students' experiences with positive expectations for students in a luscious and communicative teaching. Encouragement and challenges at the appropriate level, which creates understanding is characteristic for the student to feel that they succeed.</p><p>The surrounding community is very important for the students' confidence. The teacher's dedication, curiosity and attention devoted to the pupils' knowledge to conquer new mathematical literacy was important for confidence. It appeared that the students should be aware of the mathematical knowledge and calculations behind the products that are in our surroundings.</p>

Not available / text

published_or_final_version / Linguistics / Master / Master of Philosophy

The modeling results of current global aerosol models agree, generally within a factor of two, with the measured surface concentrations of black carbon (BC) and sulphate (SF) aerosols in rural areas across the northern continents. However, few models are able to capture the observed seasonal cycle of the Arctic aerosols. In general, the observed seasonality of the Arctic aerosols is determined by complex processes, including transport, emissions and removal processes. In this work, the representations of aerosol deposition processes (i.e., dry deposition, in-cloud and below-cloud scavenging) within the framework of the Canadian Global Air Quality Model – GEM-AQ are first enhanced. Through the enhancements in GEM-AQ, the seasonality of the Arctic BC and SF is reproduced, and the improvement in model performance extends to the rest of the globe as well. Then, the importance of these deposition processes in governing the Arctic BC and SF seasonality is investigated. It is found that the observed seasonality of the Arctic BC and SF is mainly caused by the seasonal changes in aerosol wet scavenging, as well as the seasonal injection of aerosols from surrounding source regions. Being able to reproduce the seasonality of the Arctic BC, the enhanced GEM-AQ allows more accurate assessment of the contributions of anthropogenic sources to the BC abundance in the Arctic air and deposition to the Arctic surface. Simulating results on regional contributions to the Arctic BC show a strong dependence on altitude. The results reinforce the previous finding of Eurasia being the dominant contributor to the surface BC in the Arctic, and suggest a significant contribution from Asian Russia. In addition to the seasonality of the Arctic aerosols, the inter-annual variation in the Arctic BC surface concentration is also investigated. To complement the 3-D GEM-AQ model, the atmospheric backward trajectory analysis, together with estimated BC emissions, is implemented as a computational effective approach to reconstruct BC surface concentrations observed at the Canadian high Arctic station, Alert. Strong correlations are found between the reconstructed and the measured BC in the cold season at Alert between 1990 and 2005, which implies that atmospheric transport and emissions are the major contributors to the observed inter-annual variations and trends in BC. The regional contributions estimated annually from 1990 through 2005 suggest that Eurasia is the major contributor in winter and spring to the near-surface BC level at Alert with a 16-year average contribution of over 85% (specifically 94% in winter and 70% in spring). A decreasing trend in the Eurasian contribution to the Arctic is found in this study, which is mainly due to regional emission reduction. However, the inter-annual variation in the North American contribution shows no clear trend.

Post-zygotic genetic variation has previously been shown in healthy individuals and linked to various disorders. The definition of post-zygotic or somatic variation is the existence of genetically distinct populations of cells in a subject derived from a single zygote. Structural changes in the human genome are a major type of inter-individual genetic variation and copy number variation (CNV), involving changes in the copy number of genes, are one of the best studied category of structural genetic changes. In paper I we reported a pair of healthy female monozygotic (MZ) twins discordant for aneuploidy of chromosomes X and Y, contributing to the delineation of the frequency of somatic variation in MZ twins. It also illustrates the plasticity of the genome for tolerating large aberrations in healthy subjects. In paper II we showed age-related accumulation of copy number variation in the nuclear genomes in vivo for both megabase- and kilobase-range variants. Using age-stratified MZ twins and single-born subjects, we detected megabase-range aberrations in 3.4% of people ≥60 years old but not in individuals younger than 55 years. Moreover, the longitudinal analysis of subjects with aberrations suggests that the aberrant cell clones are not immortalized and disappear from circulation. We also showed that sorted blood cells display different genomic profiles.  The detected recurrent rearrangements are candidates for common age-related defects in blood cells. This work might help to describe the cause of an age-related decline in the number of cell clones in the blood, which is one of the hallmarks of immunosenescence. In paper III we described a variable number tandem repeat (VNTR) ~4 kb upstream of the IFNAR1 gene, which was somatically variable.  We detected 14 alleles displaying inter- and intra-individual variation. Further analyses indicated strong clustering of transcription factor binding sites within this region, suggesting an enhancer. This putative VNTR-based enhancer might influence the transcriptional regulation of neighboring cytokine receptor genes and the pathways they are involved in. These three studies stress the importance of research on post-zygotic variation in genetics. Furthermore, they emphasize that biobanks should consider sampling of multiple tissues to better address this issue in the genetic studies.

Recent retrospectives of classic psychology articles by Meehl (1978) and Wachtel (1980), concerning problems with psychology’s research paradigm, have been viewed by commentators, on the whole, as germane as when first published. However, no similar examination of Lykken’s (1991) classic criticisms of psychology’s dominant research tradition has been undertaken. Twenty years on, this thesis investigates whether Lykken’s criticisms and conclusions are still valid via an exposition of three contentious issues in psychological science: the measurement problem, null hypothesis significance testing, and the granularity of research methods. Though finding that little progress has been made, Observation Oriented Modelling is advanced as a promising methodological solution for improving psychological research.

The modeling results of current global aerosol models agree, generally within a factor of two, with the measured surface concentrations of black carbon (BC) and sulphate (SF) aerosols in rural areas across the northern continents. However, few models are able to capture the observed seasonal cycle of the Arctic aerosols. In general, the observed seasonality of the Arctic aerosols is determined by complex processes, including transport, emissions and removal processes. In this work, the representations of aerosol deposition processes (i.e., dry deposition, in-cloud and below-cloud scavenging) within the framework of the Canadian Global Air Quality Model – GEM-AQ are first enhanced. Through the enhancements in GEM-AQ, the seasonality of the Arctic BC and SF is reproduced, and the improvement in model performance extends to the rest of the globe as well. Then, the importance of these deposition processes in governing the Arctic BC and SF seasonality is investigated. It is found that the observed seasonality of the Arctic BC and SF is mainly caused by the seasonal changes in aerosol wet scavenging, as well as the seasonal injection of aerosols from surrounding source regions. Being able to reproduce the seasonality of the Arctic BC, the enhanced GEM-AQ allows more accurate assessment of the contributions of anthropogenic sources to the BC abundance in the Arctic air and deposition to the Arctic surface. Simulating results on regional contributions to the Arctic BC show a strong dependence on altitude. The results reinforce the previous finding of Eurasia being the dominant contributor to the surface BC in the Arctic, and suggest a significant contribution from Asian Russia. In addition to the seasonality of the Arctic aerosols, the inter-annual variation in the Arctic BC surface concentration is also investigated. To complement the 3-D GEM-AQ model, the atmospheric backward trajectory analysis, together with estimated BC emissions, is implemented as a computational effective approach to reconstruct BC surface concentrations observed at the Canadian high Arctic station, Alert. Strong correlations are found between the reconstructed and the measured BC in the cold season at Alert between 1990 and 2005, which implies that atmospheric transport and emissions are the major contributors to the observed inter-annual variations and trends in BC. The regional contributions estimated annually from 1990 through 2005 suggest that Eurasia is the major contributor in winter and spring to the near-surface BC level at Alert with a 16-year average contribution of over 85% (specifically 94% in winter and 70% in spring). A decreasing trend in the Eurasian contribution to the Arctic is found in this study, which is mainly due to regional emission reduction. However, the inter-annual variation in the North American contribution shows no clear trend.

Bacterial endophytes, bacteria residing within plants, play an important role in the growth and development of plants and their ability to thrive under adverse conditions. The endophytes of Acer negundo, Ulmus pumila and Ulmus parvifolia trees sampled from a hydrocarbon-contaminated site were analyzed for variation between seasons and plant species. Branches from the same trees over a span of 3 seasons were collected and analyzed via culture dependent and culture independent methods. Numerous culture independent approaches were tested, culminating in the development of a new method for the amplification of endophytic bacterial ribosomal DNA that excludes plastid DNA. Community analyses using this new method in combination with T-RFLP showed significant differences between the endophytic communities of different plants species and of the same species growing in different seasons. The proposed technique can be used for the future study of endophytic communities of plants.

Bacterial endophytes, bacteria residing within plants, play an important role in the growth and development of plants and their ability to thrive under adverse conditions. The endophytes of Acer negundo, Ulmus pumila and Ulmus parvifolia trees sampled from a hydrocarbon-contaminated site were analyzed for variation between seasons and plant species. Branches from the same trees over a span of 3 seasons were collected and analyzed via culture dependent and culture independent methods. Numerous culture independent approaches were tested, culminating in the development of a new method for the amplification of endophytic bacterial ribosomal DNA that excludes plastid DNA. Community analyses using this new method in combination with T-RFLP showed significant differences between the endophytic communities of different plants species and of the same species growing in different seasons. The proposed technique can be used for the future study of endophytic communities of plants.