During the nineties, ecological handling of urban storm water became very popular in Sweden. Together with Chalmers University of Technology and two Swedish communities, DHI Water and Environment has been doing research of storm water ponds and constructed wetlands. This thesis work is a part of that research project. The work has been applied at the Bäckaslöv storm water treatment plant in Växjö, Sweden. The plant consists of one storm water pond and a downstream constructed wetland.

The aim of this thesis project is to produce an algorithm for finding a topologicalrepresentation of a polygon, called a straight skeleton, using floating pointarithmetic. Various straight skeleton algorithms are examined and discussed witha focus on time complexity and one is chosen for implementation. This implementationis then compared with the open source library CGAL with regards torunning time. The result is an algorithm which is based on an algorithm by Felkeland Obdrzalek and which, for polygons with more than five thousand vertices andthree significant digits representing points, runs around 25% faster than CGALsimplementation. Complications regarding the use of floating-point arithmetic arealso discussed..

The loss of such great wetlands, which has arose in Sweden the last decades, has created a situation that threats both the function and the biological diversity within the wetlands. Many ecological niches can be found in the wetlands and it is one of the habitats where most different species exist. In the 17th Century people started to ditch damp environments, such as bogs, to create a productive cultivated ground. Further ditches were made when the forestry gave large economical profits. The wetlands were impoverished from both groundwater and nourishment, and this led to a great loss of species.In a corporation with WWF and Skogsstyrelsen in Arvika, the University of Karlstad has participated in the Laskerudproject, a hydrological restoration-project in a forest landscape.

BIOGAS POTENTIAL IN GRASSES FROM WETLANDSMarvin MartinsThe purpose of this study has been to survey wetlands that are suitable for mowing and to analyze the biogas potential in the harvested grasses. A preformed investigation showed that there are suitable wetlands, which can be harvestable, namely those mowed formerly in traditional haymaking. The practice of traditional haymaking is dying out in Sweden today but there are several good reasons why it should to be reconsidered. Nature- and cultural values are obvious, also the unutilized energy in the grass.The suitable types of wetland that were specifically studied were the productive wetlands; meadow marshes and wet meadows. These wetlands are represented in the Swedish meadow- and pasture inventory database; (TUVA) and the Swedish national wetland inventory (VMI).

SummaryI have a great interest in bouzoukis and since I, during my education in guitar making, mainly have focused on building bouzoukis and other traditional folk instruments, I have chosen the bouzouki as the object of my degree project.In connection to the making of these instruments, I started to consider the construction of the bouzouki and why the bouzouki has such a characteristic sound.One of my theories is based on the fact that most bouzoukis are made with floating bridges instead of glued pinbridges. Do these types of bridges differ from each other tonally and if so, how much and in what way?To receive answers to my questions, I have built two identical bouzoukis with different types of bridges, one with a glued pinbridge and one with a floating bridge. I have been very precise in the making of these instruments, giving them the exact same dimensions and using material from the same piece of wood. This to make sure that the instruments should be as exactly alike as possible.After finishing the making of the bouzoukis, I arranged for a sound test where I let musicians play and listen to the instruments.

I have done a follow up study of the restoration of two rivers, Röälven and Grundan, in order to evaluate the effects of the restoration on the endemic population of trout. Both rivers have been used for timber floating during many years throughout the 20th century, and because of this, had all obstacles such as rocks and wood parts removed. In 2004-2005 both rivers were restored, and rocks and wood were put back into the rivers. Spawning grounds were created and boulder dams were constructed to promote the streaming water. The result showed that the trout population of both rivers increased after the restoration, but also that the trout population of Röälven increased more than that of Grundan.

In ambition to produce more and better harvests, artificial fertilizers are used to produce a better growth of crops in the agriculture landscape. This contributes to leakage of nutrients. Our forests also exhibit a leakage of nutrients. Air pollution contributes to more nutrients. High precipitation with high water flows as a consequence seems currently to occur more frequently in the county of Halland.

In this master thesis, the possibilities of customizing a low-cost microprocessor with the purpose of replacing an existing microprocessor solution are investigated. A brief survey of suitable processors is carried out wherein a replacement is chosen. The replacement processor is then analyzed and extended with accelerators in order to match set requirements.The result is a port of the processor Lattice Mico32 for the FPGA curcuit Xilinx Virtex-5 which replaces an earlier solution using Xilinx MicroBlaze. To reach the set requirements, accelerators for floating point arithmetics and FIR filtering have been developed. The toolchain for the processor has been modified to support the addition of accelerated floating point arithmetics.A final evaluation of the presented solution shows that it fulfills the set requirements and constitutes a functional replacement for the previous solution..

In coastal wetlands carbon/organic matter can be stored for long periods of time thanks to, among other things, the presence of water which slows down the decomposition. Because of this, restauration and management of such habitats have the potential to decrease the emission of greenhouse gasses and help mitigate climate. Internationally these environments are called ?blue carbon? ecosystems. In Sweden, alder (Alnus glutinosa and Alnus incanata) covered wetlands along the coast is a nature type that potentially could function as a ?blue carbon? habitat.

Wetlands are important ecosystems and form habitat for both common and threatened species. In Sweden, as well in many other places on earth, there is a lack of wetlands. There is an expressed will to adjust this lack through restoration of wetlands with reduced function and through construction of new wetlands. Follow-ups and evaluations are important steps to optimize these actions. The wetland Vattenparken was constructed 1999 ? 2000 for treatment of surface water.

The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

Seventy-two working horses (they had been ridden with bit and bridle within the last two weeks) were examined in the oral cavity. Findings and status were noted. The horses were randomly chosen among individuals without clinical symptoms from the mouth and gastrointestinal system. The result showed that 93% of the horses had changes in the mucus membranes, 86% in the form of ulcerations. The P2 region was most commonly affected followed by wounds more caudally in the mouth (P3-M3 region).

Treatment wetlands been showed efficient for reducing pollutant in waste water. In Lajeado ? RS, Brazil the landfill has poor leachate water treatment. It is necessary to supplement the treatment plant because they need to reduce BOD, COD and nitrate of the water going to recipient. A subsurface flow wetland (SSF) can be a good choice.  In order to be able to design an efficient SSF it is important to understand how the grain sizes of a substrate affect the reducing of pollutants in waste water.

The practice of landscape architectural involves forming the space in our cities and suburbs, as well as the landscape surrounding. The need of exploiting green environment leads up to, among other issues, flood problem during heavy rain and overfed water environments. The problem is partially caused by the shortage of knowledge, how the environment is responding of the innovations made by the city- urban planning and how to get sustainability. Research and knowledge how to take care of our environment, in a natural way, is increasing. The object of the thesis is to propose control and balance in urban wetlands, and discuss the difference a plant design can do. The thesis deals with discourses in the field of landscape architecture, biological diversity, dam construction, limnology, planting design and management, pollution of the environment and urban design practice.

The overall aim is to examine how the European Union Water Framework Directive has affected the local water management in the catchment Märstaån situated in the eastern part of the lake Mälaren river basin, Sweden. The first part of the study gives an historical overview of the area with focus on how the old agricultural landscape was handling the nutrient load from farming activities by means of different kinds of wetlands. By using the concept of the procedural landscape, introduced by Torsten Hägerstrand , together with historical maps with dates starting from the 17th century, the pre-modern landscape is analyzed.  The second part is an investigation, based on qualitative data, on how the different actors in the catchment area work together to secure the water quality for the Märstaån river. The analysis shows that the Märstaån catchment river systems are mostly unchanged in the rural areas.  The exception is the mainstream section of the Märstaån river running partly underground today and the Halmsjöbäcken river that is heavily affected by the Arlanda airport situated within the catchment area.