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1999 Uppsatser om Ground water modeling - Sida 55 av 134

Mixture and single-compound toxicity using Daphnia magna : comparisons with estimates of concentration addition and independent action

Aquatic organisms are usually not exposed to single substances but rather to mixtures of toxicants in streams located in agricultural areas. The transport of pesticides used in the agricultural area in Sweden is monitored with continuous environmental supervision every year. During 2002-2008 an average of 10 pesticides were found in each sample and 40% of the samples contained substances with concentrations higher than the Water Quality Standards. Chemical risk management is normally based on single-test evaluations. A problem when assessing mixture toxicities is that the constituents and concentrations of pollutants in the environment vary greatly.

Produktutveckling av koncept för isbanesystem

Today most ice rinks in Sweden use secondary refrigeration systems with a solution of calcium chloride and water as secondary refrigerant. Due to the large amount of energy such a system uses more efficient systems would be desired.An earlier study concluded in the possibilities of using carbon dioxide as secondary refrigerant with copper tubes as the loops in the ice rink. Since then 3 ice rink refrigeration systems has been built with carbon dioxide in copper tubes. Excluding the ones being direct involved in those projects there is still very little knowledge about how these system works. This study has been made primarily with the aim of adding to the knowledge concerning availability and cost and secondary to look at possibilities for improvement.A comparison between systems with carbon dioxide, calcium chloride respective ammonium solved in water has been made by using Decision Matrix.

Evaluation of an ectomycorrhizal macrofungi as an indicator species of high conservation value pine-heath forests in northern Sweden

Since the 1950s, the development of modern rotation forestry in boreal Fennoscandia has resulted in a severe reduction of older forests, and a high degree of fragmentation among the small patches that remains of old forest. In Sweden, when performing conservation value assessments in order to identify and preserve the remaining forest habitats, the government authorities use to a significant extent a set of indicator species that indicate habitats of high biological conservation value. One species considered to indicate high conservation values in pine-heath forests is the red-listed ectomycorrhizal (EM) macrofungi Sarcodon scabrosus (Fr.) P. Karst. In the present study, the validity of using S.

Biodling i Stockholms stadskärna : Ekonomi, ekologi eller ekosofi?

Previous research confirms that there is a major decline of pollinators worldwide. Investigations have mainly focused on pollination services in the agricultural landscapes and therefore, there is a lack of knowledge on the effects pollinators may have in urban environment. This paper examines the presence of honey bees in central parts of Stockholm, Sweden. The study presents what conditions, possibilities and motives there are behind the phenomenon of urban bee keeping. I found ten locations with beehives and a total of 18 hives within the delimited area. Nothing seems to indicate that conditions may limit the presence of honey bees.

Passivhus av helväggselement i träull

Environmental destruction is a growing problem in our world. Almost every day there are new reports concerning that we have to do something about the greenhouse gasses. Simultaneously is the human constantly more eager to have a life with higher standards and therefore uses more energy. The environment is a question that is highly up-to-date and more people try to find solutions on how to save our planet. One way to decrease the energy demand is to build passive houses, where the houses don?t have any active heating.

Utformning av hamnområdet i Arvika : stadsbild och offentliga miljöer

The harbour in Arvika is closed down and the industry that has been established in the area is now beeing wound up. A deepened comprehensive plan for the area is under progress in the municipality. The intentions are for instance that the harbour should be integrated with the city and that Arvika is facing a lake should be more apparent from the city center. The harbour should also contribute to a more attractive city. These intentions have hence been the starting point of my undergraduate theses, which has resulted in a proposal on how to develop the harbour. During the process I have analysed the city image, how the area is used today and the public places in the city centre.

På vandring mot handling : Utbyte av perspektiv i landskapet

Sustainable Development is often described as a balance between ecological, economical and social aspects. Between these exists a complicated interaction that creates conflicts in the planning of the landscape. We see a growing need for a functional interaction between values and interest and an understanding for different perspectives. Cooperation and dialogue are key ideas with the focus on cooperation rather than the goal. There is a lack of forum for dialogue and cooperation within municipalities where a great knowledge and competence are gathered.

Utveckling av takra?cken fo?r sla?pvagnar

This report is a bachelor thesis work in the field of product development and design. The assignment has been to develop a solution for roof racks, normally used for cars, to fit on the open trailer models FS1425 and Alugance. The project was implemented by Johan Andersson and Victor Karlsson, students at the Mechanical Engineering program with a focus on product development and design at Jo?nko?ping?s school of Engineering, in spring 2012.The client wants to use transport solutions in the same way as roof racks on cars. The user of such a product is assumed to desire simplicity, safety and an attractive design with an appealing price, which has been a challenge during the thesis work.Pre-studies have been conducted to examine the potential competitors and gain knowledge in the research area.

Systemlösningar för plus- eller passivhus : En studie med syftet att lösa energibehovet för ett specifikt hus.

The purpose of the house which is the basis of this report is to be able present itself on the market as a relatively cheap and at the same time a climate friendly choice. The house is supposed to be able to be built anywhere in Sweden and the rest of Scandinavia in a short period of time. This puts demand on what kind of heating system the house can have, since not all places have the geographic advantage of being able to use geothermal or district heating. Therefore the heating system choices will only include those that are not limited by their geographic location. The house will be built in modules which only require the groundwork to be done before the house can be erected. In this report "System solutions for plus or passive-housing" a comprehensive literature search has been conducted as well as a number of calculations.

Företaget i varseltider - Påverkan på dess effektivitet och produktivitet

Syftet med studien är att undersöka varsels effekter för företags effektivitet och produktivitet under lågkonjunktur. Vår studie bygger på intervjuer med både chefer och anställda från företaget Water Jet Sweden AB. Studiens resultat är att personal påverkas av företags beslut om varsel om uppsägning genom att arbeta mindre effektivt. Detta är så för att varslet sänker arbetsmotivationen och tryggheten vilket gör att personalen underpresterar, detta påverkar hela företaget negativt..

Löslighet och metylering av kvicksilver i en förorenad sjö (Ala-Lombolo) i Kiruna kommun :

Transformation of inorganic mercury (Hg) to methyl mercury (MeHg) is a biotic process that is proposed to be conducted primarily by sulphate reducing bacteria (SRB). The formation of MeHg is of great interest because it is the mercury species that biomagnifies to the greatest extent in the aquatic food webs; about 90 % of all Hg in fish is MeHg. Our understanding of factors involved in the production of MeHg is very important for making a reliable risk assessment. The purposes of this study were to investigate the different factors that control the solubility of Hg and the production of MeHg in a contaminated lake sediment. The lake Ala-Lombolo, Kiruna municipality, is well-known to be contaminated by mercury from different sources. Sediment cores were sampled at three different locations (N, SW and SE) in the lake and divided in three different layers; 0-5, 5-10 and 10-15 cm.

Vermicompost for reduction of vegetable waste - and a possible means to produce fish feed in aquaponic systems?

Aquaponics is a food production system consisting of a consecutive cultivation of plants and aquatic animals, fish or shellfish, in recirculating water. The plants feed on the nutritious effluents from the fish tank and bacteria converts ammonia from the fish tank into nitrate that is absorbed by the plants. The plants receive nutrition and the fish gain purified water. The environmental impact of the production of fish meal and fish oil used in conventional fish feed includes a large consumption of fossil fuels with subsequent carbon dioxide emission. The aquaponic system can be made environmentally sustainable and self-supporting if supplemented with a vermicompost/vermiculture for the production of worm protein as a fish feed. Vegetable waste from the hydroponic part of the system can be reused as worm feed in the compost and the protein rich worms can be harvested, dried and grinded and brought back to the aquaculture as fish feed. As a first step in this direction, I have investigated the effect of recycling of vegetable waste in vermicomposts on the growth and number of earthworms (this was evaluated after harvesting). The hypotheses were that earthworms can be cultivated in the vegetable waste and that by adding manure to the vermicompost it is possible to obtain a nutrient content adequate to support a continuous worm harvest, in other words create a vermiculture. Eisenia fetida and Dendrobaena veneta were grown in 20 L bins containing peat mixed with either poultry or cattle manure. The proportions were 70% peat and 30 % manure. Discarded plant parts from lettuce cultivation was added to the vermicomposts (35 g per week) and water was supplied with 0.8 L per week.

Vattentäta och ?andande? textilier

Rapporten innefattar en jämförande studie mellan olika typer av membran och beläggningar.Främst sker en jämförelse mellan materialens förmåga att andas. Vattentäthet testas på nyamaterial och efter olika sorters nötning så som martindale, flexing och tvätt för att få en ökadförståelse för materialen. Verktyget som används i studien för att mätaånggenomsläppligheten är hudmodellen. Resultatet presenteras med ett Ret-värde vilket är enförkortning på Evaporative resistance of a textile. Metoden används för att på ett bra sättsimulera hur huden svettas.Projektet har utförts på Swerea IVF som är ett forskningsinstitut beläget i Mölndal.Hudmodellen är en av de senaste stora investeringarna på Swereas textil och plast avdelning.Resultatet av studien visar att laminat andas bättre än beläggningar, dock har bärarmaterialetstor inverkan på resultaten.

Hur påverkar ny teknik företags relation och kommunikation mot sina kunder och leverantörer?: En studie av fyra företags utnyttjande av moderna affärssystem och effekterna i kund- och leverantörsrelationerna.

This qualitative case study, made with four companies, looks closer at how more effective information management, with the help of IT-systems, affect companies market communication and relations to customers and suppliers. Customer Relationship Management perspective is used and Enterprise Resource Planning-systems are the ground for new technology change. The main conclusions are that new technology affects the outcome of companies? relationships towards their customers and suppliers and that the processes and activities between the involved parties are more closely linked. Also involving your suppliers and external actors makes the information handling more effective and companies that do so most likely have a competitive advantage..

Fågel fisk eller mittemellan?

The project is a thesis which intends to strengthen the form language and increase the user friendliness of an International Moth. This is a single handed dinghy with only one sail. It sails on two hydrofoils and receives a very high speed compared to its size, and are therefore often referred to as ?the Formula One on water ?. The result is a new concept where the aerodynamic forces have been used to stabilize the boat and relieve the hydrofoils.

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