Sammanfattning   Undersökningen i denna studie handlar om förskolebarns tankar om nederbörd och olika nederbördsformer. Genom kvalitativa intervjuer visas barnens tankar kring nederbörd. I undersökningen intervjuades åtta förskolebarn i åldern tre till fem år.   Resultatet som tolkats visar att barns uppfattning av snö och regn är att det kommer från himlen. Majoriteten av barnen vet att regn är vatten.  De kopplar inte ihop moln med nederbörd. Barnen förstår att is är den fasta formen av vatten men inte att även snö är det. Något barn förstår fasövergången mellan flytande till fast. Att is smälter av värme vet barnen och de förstår att temperaturen har betydelse. Däremot visar barnen inte ett tydligt tecken på att de förstår innebörden i avdunstning med vatten i flytande form som övergår till vatten i gasform. Barnen visar ingen förståelse för fenomenet kondensation.      Nyckelord: förskolan, regn, snö, yngre barn / Abstract   The investigation in this study is about preschool children's ideas about precipitation and different forms of precipitation. Through qualitative interviews shows the children's ideas about precipitation. In the survey interviewed eight preschool children in the aged three to five years.   The result which has been interpreted is that children's perception of snow and rain is that it comes from heaven. The majority of the children know that rain is water. They do not associate clouds with precipitation. The children understand that ice is the solid form of water but not that snow is that. One of the children understands the phase transition between liquid to solid. That the ice is melting in heat understand the children and they understand that the temperature is significant. However the children show no clear signs that they understand the meaning of evaporation, that there is water in liquid form which is put into water in gaseous form. The children show no understanding of the phenomenon of condensation.    Keywords: preschool, rain, snow, younger children

Leptosporangiate ferns, with more than 9000 extant species, are truly exceptional among the non-flowering lineages of vascular plants. However, this rather remarkable diversity was not simply a consequence of being able to "hold on" as flowering plants rose to dominance. Instead, it appears to be the result of an ecological opportunistic response to the establishment of more complex, angiosperm-dominated ecosystems. The proliferation of flowering plants across the landscape undoubtedly resulted in the formation of a plethora of new niches into which leptosporangiate ferns could diversify. Many of these were evidently on shady forest floors, but many others were actually within the new angiosperm-dominated canopies. Today, almost one third of leptosporangiate species grow as epiphytes on angiosperm trees. My dissertation aims to demystify the evolution and diversification of epiphytic ferns in order to more fully understand the leptosporangiate success story. By assembling and analyzing the most inclusive molecular dataset for leptosporangiate ferns to date, I provide unprecedented insight into overall fern relationships and a solid and balanced phylogenetic framework within which the evolution of epiphytism can be examined. By employing this phylogeny and numerous constraints from the fern fossil record, I uncover the timing of epiphytic fern diversification and examine the origin of the modern tropical rain forest biome in which these ferns reside. / Dissertation

Thesis (doctoral) - Delft University of Technology, Delft, 2002. / "Dissertation submitted in fulfillment of the requirements of the Board for Doctorates of Delft University of Technology and of the Academic Board of the International Institute for Infrastructural, Hydraulic and Environmental Engineering for the Degree of Doctor to be defended in public on Monday, 29 April 2002 at 13:30 hours in Delft, The Netherlands." Includes bibliographical references (p. [191]-199).

Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references (leaves 52-62). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 185-199). Also available on the Internet.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : 48-51).

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 185-199). Also available on the Internet.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 97-106).

Emissions of ammonia (NH3) into the atmosphere, principally from agricultural sources, have been implicated in the pollution of forests, moorlands and grasslands, through the subsequent deposition of reduced nitrogen (NH,, -N). Consequently, legislation has been implemented to control both the transboundary transport and local environmental impacts of NH,,. This thesis investigates the emission, dispersion and local deposition of N113 from two sources that are major components of national N113 emissions inventories, slurry applied to grassland and naturally ventilated cattle buildings. AN balance method was identified for determining the time-average deposition of N113 downwind of a farm building, whilst an adapted micrometeorological flux-gradient technique was developed for estimating local deposition downwind of slurry spreading. This method used an analytical atmospheric dispersion model to provide advection corrections to the standard flux-gradient method. The UK-ADMS model, which incorporates a reasonably detailed treatment of building effects, was identified for use in determining the near-field dispersion from naturally ventilated farm buildings. Eight field experiments were conducted to determine the emission, dispersion and local deposition of N113 volatilised from slurry applications. Emission fluxes during the initial runs following slurry spreading were found to depend on friction velocity, relative humidity and rainfall. Local deposition, at sufficient rates to affect local deposition budgets, was not found to occur during near-freezing conditions or following the application of fertilisers. Local deposition velocities during other periods were found to depend on the latent heat flux, temperature and the roughness length. During such periods, 14 - 18 % of the emitted NH3 was estimated to deposit within 50 rn of the source. Experiments were also conducted at two naturally ventilated farm buildings, the Silsoe Research Institute Structures Building and a working dairy farm. Ammonia emission factors were determined for the main building and slurry lagoon at the dairy farm. A novel application of a model back-calculation method was applied to determine the emission from the lagoon. Dispersion of NH3 from both sites was found to be adequately modelled using UK-ADMS. Approximately 2% of the emitted NH3 deposited within 100 - 150 rn of each building. Time averaged deposition velocities calculated from the farm building studies confirmed that NH3 was deposited to the leaf surfaces and uptaken across the leaf cuticle. Temperature dependent exchange rates were also indicated by the results of the farm building experiments, With NH3 uptake being regulated by the assimilation potential of the plant. The experimental results demonstrated that deposition around both sources could lead to local critical load exceedancesT. hese were only estimatedt o occur within a few tens of metres downwind of slurry spreading whilst critical load exceedancesw ere predicted at distanceso f up to 100 m or more downwind of the farm building. The temporal variability in local recapture found in these experiments, particularly for farm buildings, suggests that seasonal variability in the treatment of N113 eniission and deposition should be included in atmospheric transport models. Furthermore, it is possible that transboundary transport of NHx may increase during winter periods with peak housing emissions.

This thesis presents data from an integrated study of precip~tation, ground and surface water chemistry from 460 km of the Peak District, between May 1987 and April 1988. All samples have been analysed for a suite of nine major ions. Data have been used to: (1) describe temporal and spatial variability of acid precipitation and deposition; (2); examine the controls on precipitation chemistry; (3) describe the chemistry of sampled waters and elucidate catchment processes; and (4) examine the impact of bulk deposition on ground and surface water chemistry. The dense network of collectors has clearly identified significant small scale variability of precipitation chemistry across the study area. However, temporal variability is consistent with observations of other workers. It has been statistically demonstrated that calcium and non-marine sulphate have a close temporal and spatial association. This is hypothesised as being the result of atmospheric reactions between regional gaseous sulphur dioxide and extractive industry derived calcium. The resultant calcium sulphate is prinCipally removed by below cloud scavenging and dry deposition. All sampled groundwaters bave .a high acid neutralising capacity which illustrates the dominance of limestone solutional processes. Surface waters have relatively high concentrations of base cations indicating some buffering potential. However, high variability of bo~~ hydrogen and aluminium suggests a limited buffering capability during storm events. Advanced statistical techniques have demonstrated a complex association between surface water acidification and the bulk deposition of marine ions. This is consistent with the findings of other researchers. Cross and partial correlation have shown the mobility of aluminium in acid sensitive waters to be related to elevated loadings of hydrogen. This research has demonstrated the importance of finescale resolution in precipitation chemistry monitoring networks. Advanced statistical techniques have identified relationships between precipitation chemistry and ground and surface water quality in a geologically complex ..environment.