Sök:

Sökresultat:

249 Uppsatser om Lake sediment - Sida 11 av 17

Hemoglobinkoncentrationen och dess påverkan på individens känslighet för AMS vid höghöjdsvistelse.

Kroppens prestation försämras vid höghöjdsvistelse pga. syrebrist och individer kan drabbas av akut höjdsjuka (AMS). Samtidigt acklimatiserar sig kroppen genom att bl.a. öka syreupptaget som kompensation för det låga syretrycket. Studiens syfte var att undersöka hur hemoglobinkoncentrationen (Hb) påverkas av hög höjd och om det finns någon korrelation mellan Hb i vila eller Hb-ökningen under arbete tillika individers välmående på hög höjd.

Hur såg Birkas hamn ut och vilka transporter behövdes?

What is located on the bottom in the water outside of Birka? Remains of a water palisade or jetties and other constructions.Birka a Viking Age town that existed between AD 750 and 975 was located on the northwestern part of the small island of Björkö, in the Mälar archipelago of the Baltic Sea in Sweden. The Town was protected onshore by a hill fort and a town rampart. It is a widely spread assumption that Birka had a water palisade as a part of its defense. There are logs and other remnants on the bottom of the lake dating back to the Viking age.

En geokemisk kartering över området kring Nasa silvergruva : Effekterna av historisk gruvdrift i svensk fjällmiljö

The aim of the study was to map the extent of Fe, Cu, Pb, As, Zn and S contamination in the area surrounding the Nasa silver mine. The mine operated between 1635 and 1810 with some prospecting performed in 1889, and has become infamous for the gruesome ways that the indigenous people were treated during the early years of operation. This study tested three hypotheses through a geochemical survey: 1) sulfide oxidation is still active in the abandoned mine, 2) the soil downslope of the mine is contaminated by mine drainage, and 3) the stream downslope of the mine is affected in the same way. All three hypotheses were valid, as the results showed that still, >200 years after mining operations ceased, signs of the historical mining are clearly visible in the surrounding environment. Acidic conditions were discovered in surface waters close to the waste rock piles, which indicates active sulfide oxidation.

Kantzoner, skogsbruk och vattenkvalitet : modellgenererad kantzonsbredd

Kantzoner mot vattendrag är av stor betydelse för att upprätthålla eller förbättra vattenkvaliteten i våra vattendrag. De strandnära zonerna fungerar som reservat i skogen med stor biologisk mångfald. De utgör barriärer för näringsämnen, löst organiskt kol, sediment, kvicksilver och andra miljögifter. Trädens rötter armerar jorden närmast vattendraget och minskar erosion och sedimentation. Syftet med detta arbete har varit att beskriva varför kantzoner bör användas och hur bredden på kantzonen, med hjälp av en modell i ArcMap, kan anpassas efter förhållandena runt vattendraget.

Dagvatten i Märsta : förslag till anläggning för ekologisk hantering samt metodöversikt

Stormwater in urban areas has been treated as a problem for a long time. The large proportion of impermeable surfaces inhibits the water from infiltrating in the ground to the same extent that it does in nature. This causes intensive surface flow during rain, which in turn causes inconveniences such as decreased accessability, floods and increased risk of desease spreading. Drainage through pipes is the traditional and usually functional metod for storm water disposal. That is as long as water flows are moderate. But precipitation varies naturally in amount and intensity and additional impermeable surfaces make some pipes insufficient for heavy or lasting precipitation.

Lokala skillnader i konsumtion av påväxtalger och terrestra löv hos en differentierad population av Asellus aquaticus

That ecological and evolutionary processes can take place on the same time scale is a recent insight. Today we also know that they are directly linked to each other. In the lake Tåkern, in year 2000, there was a structural change when phytoplankton declined and submerged vegetation, mainly stoneworts began to spread. This led to evolutionary changes in the aquatic sowbug, Asellus aquaticus which had previously been limited to the reed, most likely feeding on detritus. But then, sowbugs could exploit the new habitat in stoneworts and a new food resource in terms of periphyton.

Vegetationens roll i erosiva vattendrag : en review och fältstudie av två nyckelområden i Rönne å

The vegetation?s impact on erosion control is widely explored, even though research? results are scattered where it suggests a both positive and negative relationship between roots and erosion tendency. Research has measured the roots? impact on erosion by many different methods, hence the aim of this study is to offer a clearance of what factors play an important role in the choice of appropriate species controlling river bank erosion. I have therefore studied 17 articles concerning vegetation and erosion control, which were found in different databases such as: Web of Knowledge, Biological Sciences, Academic Search Elite and Google Scholar.

Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet

Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).

Trattbägarkeramik i Väte : när jordbruket kom till Gotland

This essay is a study and analysis of the funnel beaker pottery at Gullarve 1:13 in Väte parish. The purpose of the study is to analyse the chronology of the settlement by determine the distribution, stratigraphic context and the ornamentation of the pottery. Another purpose is to discuss the geographical location of the settlement in the landscape.In this essay a short review of the pottery and the funnel beaker culture as well as a description of the pottery from the archaeological excavation from 1984 at Gullarve 1:13 is presented. Since the documentation of the archaeological excavation from 1984 is missing or is very inadequate, no spatial analysis can be carried out. The distribution of the pottery can?t contribute to the result of the essay, though if possible it probably would have provided some interesting results.

Habitatpreferenser hos tjockskalig målarmussla (Unio crassus) med avseende på vattendjup och beskuggning.

The thick-shelled river mussel (Unio crassus) is a red listed species classified as Endangered (EN) and is also considered within the Habitats Directive. The distribution in Sweden is fragmented and it is mostly occurring in the south eastern parts. We investigated the presence of Unio crassus in a section of the stream Storån, Östergötland County, from Falerum to the inflow into Lake Åkervristen. The environmental parameters investigated were water depth, bottom substrate, shading, water velocity and the slope over the water surface. In this thesis I have focused mainly on water depth and shading, comparing sites with and without mussels.

Studier av habitatval och revirstrukturer hos vassångare (Locustella luscinioides) i Tåkern

The Savi?s Warbler (Locustella luscinioides) is a recently established bird species in a few reedy shallow lakes of southern Sweden and has only been found nesting for the last twenty years. Little is known about the species' habitat preferences, breeding biology and demands for specific territory structures at breeding sites in Sweden. Knowledge of a newly established species? habitat requirements is essential to maintain a viable population and design action plans.

Hassel (Corylus avellana) som indikator på markanvändningshistorik

Hazel (Corylus avellana L.) is a common feature of meadows and pastures where it can grow in large populations and become very old. Is it possible to use the size of hazel stools for age determination and is it possible to use the size distribution of a population to provide information about how the land has been used? Hazel populations on ground where the lake-water level had been lowered, has been studied to validate an already developed growth model of hazel clones. Different hazel populations, on wooded meadows affected by mowing or grazing or overgrown meadows, were studied to evaluate the method utilizing hazel as land use indicator. The growth model was used to compare the size distributions of hazel populations with historical periods, which has been important for changes in agriculture or demography.

Båtbottenfärger innehållande TBTO : huvudsaklig källa till TBT i miljön

Antifouling paint containing the biocide bisTributyltinoxide (TBTO) has been used since1960 to reduce the occurrence of fouling on hulls on boats/ships. January 1st, 2003 theantifouling paints containing TBTO were prohibited. This ban covered all use of paintcontaining the substance TBTO. The ban was introduced because of alarming observationssuch as development of imposex in aquatic non-target organisms. Imposex is the impositionof male sexual characteristics on mainly female marine snails and occurs due to exposure toTributyltin (TBT).

Re-design of Toledo Riverfront : from industrial past to sustainable biodiverse future

Effects of climate change, urbanization and global homogenization are resulted in the degradation of land and losses of natural habitats. Ecological design integrates nature into urban environment by respecting natural ecological principles and processes and creating resilient urban biotopes which also can be used by local urban communities. The aim of the thesis is to answer the research questions: How ecological design principles can be applied for re-design of Toledo Riverfront (with requirements of the design competition)? and What is the ecological design in landscape architecture? I participated in the USA design competition with the aim to create a vision and redesign of Toledo Riverfront in Ohio State, USA. The site is located in the south point of Lake Erie. As a result of a long industrial activity, riverfront of Toledo had been transformed into inaccessible and abandoned brownfields. In my proposal I applied ecological design principles on three scales: the city of Toledo by reinforcing of ecological connection and creating green corridors along the river; the intermediate scale by suggesting public parks along the river front and on the fine level by proposing detailed design including remediation of the site and use of dredged material.

Känslighets- och osäkerhetsanalys av parametrar och indata i dagvatten- och recipientmodellen StormTac

Three methods of sensitivity and unceartainty analysis have been applied to the operative stormwater- and recipient model StormTac. The study area is the watershed of lake Flaten in the municipality Salem. StormTac?s submodels for stormwater, pollutant transport and the recipient are cosidired. In the sensitivity assessment, the model parametres and inputs were varied one at a time by a constant percentage according to the ?one at a time? (OAAT) method and the response of the outputs were calculated.

<- Föregående sida 11 Nästa sida ->