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114 Uppsatser om Floating wetlands - Sida 4 av 8

Förändringar i markanvändning över tid och dess påverkan på vattenkvalitet

The EU Water Framework Directive has led that management follows the boundaries of natural catchments.The Swedish waters suffer from a nutrient overload that originates mainly from diffuse sources such as agriculture and the subcatchment of Hackstabäcken in Vallentuna Kommun, just north of Stockholm, has been chosen for this study because of its high nutrient load and because it has undergone obvious changes in land use through the years.In this study, the land use in 1902 is compared with the land use in 2011 in order to investigate if it has influenced the ability of the landscape to produce ecosystem services related to nutrient removal. These services will continue to be produced as long as the system is stable and resilient, but when landuse changes and manure from horses increases it will lead to disturbances that can convert a system from one regime in to a completely different one. That will result in loss, or degradation, of ecosystem services such as denitrification, phosphor sedimentation and adsorption, vegetation uptake and infiltration.The results of this study are based upon area calculations of landuse from old maps from 1902 and 2011. Through these maps it becomes clear that the forests in Hackstabäcken, has increased with 170 ha together with an urbanization of 311 ha, at the same time as wetlands and arable land has diminished and lakes has suffered from reductions. Wetlands have been reduced with 76 ha and the ones remaining are of insufficient quality from a nutrient removal perspective.Data from 1902 and 2011 regarding number of horses and bovines indicated a decrease in bovines and an increase in horses.

Dikesrensning och skyddsdikning : en fältstudie och utredning av behov i södra Sverige

During the 20th century a significant proportion (about 15 %) of the peat-covered wetlands in Sweden were drained to improve forest productivity. Area wise, most of the forest drainage was done in northern Sweden, but relatively speaking a larger part of the wetlands have been drained in the southern parts of the country. Most often, the forest drainage resulted in increased forest growth, but failures were not unusual, and harmful effects, e.g. on species richness, have been a common cause for draining. Ditch cleaning is necessary for maintaining the ditches in good condition.

Kan man genom kartstudier förutse häckningsframgång för ängshök (Circus pygargus) i Uppland? :

Montagu´s harrier (Circus pygargus) is a diurnal, Eurasian raptor, which migrates from its northern breeding grounds to winter in sub-Saharan Africa. In Sweden, its core breeding area is centred on the island of Öland, with a stable breeding population of approximately 40 pairs. The province of Uppland is on the northern end the distribution range, where 4-8 pairs have regularly bred since the 1980s. In Sweden, the Montagu?s harrier is classified as an endangered (EN) species. This classification is partly due to a lack of preferred nesting habitat, such as shrub-lands or dense wetlands with Claudium spp.

Födosammansättning hos gråsäl (Halichoerus grypus) samt test av flotte för insamling av sälfekalier.

During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught.The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase.

Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län

During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams.The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net called strömöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets.

Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län

During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams.The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net calledströmöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets.

Dagvattendammars reningseffekt : påverkande faktorer och metodik för statistisk modellering

Storm water is defined as runoff from precipitation such as rain or snow. It is collected in sewage disposal systems and since it mainly originates from urban areas it can contain high levels of heavy metals, nutrients and oil etc. Polluted storm water is currently treated by different methods such as wet ponds, constructed wetlands and filter strips. This study investigates these methods, which in earlier studies have shown to give varying results regarding their treatment efficiency.This thesis has been written on commission of SWECO VIAK and was aimed at studying those parameters that may affect the treatment efficiency of nutrients and heavy metals in storm water treatment facilities (STF:s). Through literature studies the dominating treatment processes in ponds and wetlands were examined.

Parallell beräkning av omslutande volymer

This paper presents techniques for speeding up commonly used algorithms forbounding volume (BV) computation, such as the AABB, sphere and k-DOP. Byexploiting the possibilities of parallelismin modern processors, the result exceedsthe expected theoretical result. The methods focus on data-level-parallelism(DLP) using Intel?s SSE instructions, for operations on 4 parallel independentsingle precision floating point values, with a theoretical speed-up factor of 4 ondata throughput. Still, a speed-up between 7?9 are shown in the computation ofAABBs and k-DOPs.

Development and evaluation of environmental enrichment for captive Humboldt penguins

Environmental enrichment is of high importance for zoos. Borås zoo asked SLU (Swedish University of Agricultural Sciences) for a student to perform a bachelor thesis for them. The task was to develop and evaluate environmental enrichment for their Humboldt penguins. A structure was made, consisting of a sinking skeleton with a floating bridge attached to it. It was presented in an area of the pool that the keepers had experienced that the penguins did not use to any extent.

Vattenlek i förskolan : Möjligheter till fysik i förskolan

The purpose of this study is to investigate witch knowledge and thoughts children will have about the term of floating and sinking, and witch possibilities there is to make various knowledge visible in preschool physics through playing with water. The study also concern the differences and similarities between two different groups of age who have participated in the study. The study was carried out by an activity with participant observation and feedback interviews afterwards. The result shows that the possibilities to physics are many in preschool. The children expressed new thoughts and ideas who concern other phenomena in physics during the investigation and discussed similar experiments and material to examine.

Kombinerad DSP- och FPGA-lösning för en bildbehandlingsapplikation

This Master's Thesis describes the design of a new system where a digital signal processor has been added to an existing imaging system consisting of field programmable gate arrays. The new system will offer a higher degree of flexibility by considerably shortening the design time and make it possible to implement more complex algorithms than the existing ones. The choice of system architecture and a test implementation are discussed. The test implementation consists of a program for the digital signal processor and VHDL code for one of the field programmable gate arrays. The code for the digital signal processor was designed for testing on an evaluation board from Texas Instruments.

Skäran i bäcken - En lösfyndsstudie om möjliga senneolitiska offerynd på ön Hven

This paper examines the possibility of identifying votive offerings among a collection of stray finds in a Late neolithic material from one farm land on the island Hven.First, I identify the Late neolithic artefacts in a collection of stray finds and make a register as well as take photographes of the artefacts. Then I compare these stray finds with material from hoards found in Scania to analyz if any similarities arise regarding length, fragmentation and patina. Additionally, I use maps to identify wetlands and a field survey to help identify and discover important areas connected to votive offerings. There is a strong possibility that the stray finds collection contains some votive offerings because similarities can be found between the lengths of the stray finds and the materials from the hoards..

Utanförskapets villkor & Politikens möjligheter - Diskursteoretiska perspektiv på utanförskapets artikulering i 2007 års vårproposition

This thesis studies how the Swedish government articulates social exclusion within the spring budget of 2007. Through a discourse theoretical approach, inspired by Ernest Laclau and Chantal Mouffe, the empirical findings are reconstructed through the nodal point of labour and two chains of equivalence, based upon the duality between employment and unemployment. By viewing social exclusion as a phenomenon concerning discourse, identity and politics, this duality forms the basis of a deconstructive and hegemonic analysis.I argue that the term social exclusion is a powerful and flexible political concept in that it obscures ideological assumptions and objectives as well as draws attention away from alternative social concepts. Throughout the thesis social exclusion is stressed as a social category constituting the relation between individual and society. Hence I argue that it is of vital importance that the values underlying its usage are made explicit and that social exclusion as a floating signifier is made an object of academic analysis..

Dygnsvariation av metanemission från en anlagd våtmark

The aim of the study was to investigate if methane emission in a constructed wetland changed in a diurnal pattern correlating to temperature, humidity or light conditions. The gas measurements were carried out with a static chamber technique. The wetland (in Nykvarn outside of Linköping, Sweden) takes care of wastewater to reduce the nitrogen loads. Measurements were carried out at three different occasions in the summer of 1998 on two sites in the wetland. One site was close to the inflow, inhabited by Lemnaceae, and another site was located further downstream inhabited by the emergent macrophyte Typha latifolia.

Företagsrekonstruktion och förmånsrättsreformen : Vad är det som gick snett?

Sweden needs a policy that stimulates economic growth. Year 1996 the Business Reorganization Act (1996:764) came into force. The goal with this law was to savebusiness, make it profitable and avoid unnecessary bankruptcies. Shortly afterwards itturned out that the law had no positive effect. A very few numbers of companies appliedfor reconstruction and the number of applications for bankruptcies continued to increase.In 2004, in order to stabilize the situation and bring about neutrality between twoproceedings, company reorganization and bankruptcy, the government proposed thereform of priority rules.

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