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497 Uppsatser om Surface textures - Sida 33 av 34

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.

Rosenlunds bankar : Erosion och förändring sedan 1960

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.

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.

Strötorvsanvändning i djurstallar : en litteraturgenomgång

Peat litter has been used in animal houses for a long time. Because of its good ability to absorb liquid and nutrients from the manure it can create a dry surface for animals and a valuable manure product. Through changes in agricultural practises the use of peat litter has diminished and is to a great extent replaced by straw, sawdust and cutter shavings although Sweden is rich in peat-findings. The aim of this work was to summarize the presented knowledge about the used of peat litter, techniques, advantages and disadvantages and to compare with other commonly used litter materials. Articles on peat litter have been searched for in magazines, databases and books at SLU library. Visits to peat industries, interviews with peat producers and with peat researchers contributed to the material. Peat is not a uniformly material.

Förutsättningar för återintroduktion av stora gräsätare i Sverige

Biodiversity is under threat in Sweden and many species are on the brink of extinction. This is mainly due to the large-scale drainage projects during the 19th and 20th century and the increasingly intensive land use in agriculture and forestry. The intensive land use with sharply defined boundaries between the production units has in many cases led to either overgrazing or overgrowing. As a result many species have been pushed back to "leftover" habitats like shooting ranges, power line corridors, roadsides, dumps, embankments and other similar areas. Therefore the question has been raised, wether or not it is needed to re-introduce large herbivores into the wild in order to maintain the biodiversity that is related to the extensive land use.This study has been conducted as a literature review and will focus on the European bison?s (Bison bonasus) impact on other species and biodiversity; conditions for reintroducing large herbivores in Sweden are also discussed.Free roaming populations of large herbivores have a positive impact on plants, insects and many other groups of organisms.

Erfarenheter av utedrift med köttdjur i Sverige och Kanada :

Beef cattle wintering outdoors should be provided a shelter, e.g. a type of barn or corresponding. This type of production requires appropriate soil types and secured animal welfare. For example, a clean and dry resting place needs to be provided to the animals. To receive an exemption for buildings the farmer has to have something equivalent that provides an adequate shelter.

Föryngringsresultat och beräknad virkesproduktion i naturligt föryngrade tallbestånd i Västerbotten under mitten av 1990-talet :

According to the Board of Forestry, in Västerbotten, many natural regenerations of Scots pine (Pinus sylvestris) carried out on privately owned forest in the middle of 1990 in Västerbotten have rendered a bad regeneration outcome and will provide a low future forest production. The Board of Forestry believes that the negative result can be explained by the fact that the regeneration has been carried out in wrong locations and that scarification failed to work as planned. In order for an accepted rate of regeneration the guidelines of the Forrest Act require, not less than 10 years after final cutting at natural regeneration, that there should be at least 1300 (site indices 16 m) - 1700 (site indices 20 m) main crop stems per hectare. Main crop stems are defined as stems according to the place of growth and appropriate tree type, in addition with regard to quality, stage of development and damage risk have a prospect of succeeding. In addition main crop stems should be separated by surface so that the proportion sample plots with 3 meters radius, and lack main crop stems, are not more than 10 % of site indices 14 meters or higher.

Textil fotokatalytisk vattenreningsreaktor: Optimering av beredningsparametrar för titandioxidbeläggning på polyestersubstrat ämnad för vattenrening

I denna kandidatuppsats avlägsnas organiska föroreningar från vatten genom användning av textilier, vars yta belagts med nanopartiklar utav ämnet titandioxid. När titandioxid belyses med UV-strålning sker en fotokatalytisk reaktion, vilket i sin tur bryter ned bland annat bakterier och organiska färgämnen. I hopp om att finna ultimat vidhäftning mot textil passande titandioxid har olika typer av beläggningar studerats; akrylbaserade, sol-gel och slutligen en hybrid. Dessutom har fem olika konstruktioner av textila bindningar jämförts i syfte att undersöka dess påverkan på den fotokatalytiska effekten. Förorenade vatten är ett stort problem, både i utvecklingsländer och i industriella sammanhang.

Tegel och klinker - keramiska material på mark :

Being an architect I create spaces with roof, walls and fl oor. The availability of the essential materials to create such spaces is practically unlimited. The materials also play a significant part to the character of the created space. I hope to contribute to the general understanding of materials as elements in the design of urban spaces by having intensely explored one specific material in depth, pointing out its bad and good qualities. I am of the opinion that the reason for choosing a material shouldn?t be because of a shortage of knowledge, facts or references, but what character you want for the room. When travelling across Europe, it sometimes feels like clay paving is everywhere, but back in Sweden it is almost unseen of in modern landscape architecture.

En internationell jämförelse av miljölagstiftning avseende växtnäringsläckage med ursprung i jordbruket

SAMMANFATTNINGÖvergödning har de senaste åren blivit en stor och omdebatterad fråga i många EU- länder.Även om problemen har minskat en del är detta inte tillräckligt, vi ser fortfarande fiskdöd,syrefria bottnar och giftiga algblomningar. Hur långt ska vi gå för att kunna övervinnaövergödningsproblemen? Genom olika sorters lagstiftning, ekonomiska styrmedel ochrådgivning har vi nått en bit på vägen, men fortfarande krävs det mycket arbete innan vi haruppnått målet. Jordbruket har pekats ut som en av de största källorna till övergödning pågrund av överskottet av kväve och fosfor som varje år urlakas ur våra jordbruksmarker.Inom EU finns sedan 1991 en gemensam lagstiftning; Nitratdirektivet. Syftet med direktivetär att minska nitratföroreningar och andra föroreningar från jordbruket, då dessa påverkarsåväl yt- och grundvatten som kust- och havsvatten.

Textilteknisk menisk

Denna rapport presenterar det examensarbete som gjorts i samarbete med företaget Artimplant. Syftet med arbetet är att ta fram en prototyp av ett meniskimplantat i trikåteknik. Det kräver stickning av en given form och att prototypen ska inneha vissa egenskaper.Ämnesområden som berörs under arbetets gång är textiltillverkning med inriktning mot väfttrikå samt medicinsk textil. Förutom textila ämnesområden tas även ämnen som knäledens anatomi och meniskens uppbyggnad, funktion och skador upp. Kunskaper inom dessa områden krävs för att på bästa sätt ta fram prototyper av meniskimplantat.Att sticka det triangulära tvärsnittet och den böjda formen som krävs för ett meniskimplantat har varit ett arbete som pågått under hela projektet.

Ljussättning av det lilla trädgårdsrummet :

Sammanfattning Eftsom kalla Sverige blir mörkt ganska tidigt på kvällen på höst, vinter och vår ville jag se hur man kunde förlänga användandet av det lilla trädgårdsrummet både i tid på dygnet och i tid på säsongen. Jag tycker att ljussättning är en viktig del av gestaltningen, belysningen gör trädgården levande. Mitt syfte med arbetet var att skaffa mig grundläggande kunskap om ljussättning och ljuskällor, för att sedan skissa på koncept för det lilla trädgårdsrummet. För att lyckas med detta behövde jag ta reda vad ljus är och hur det fungerar. Ljuset har många olika egenskaper, t ex olika våglängder, och färger.

Survey of regulations concerning pesticides in Sweden and the EU : cultivation techniques and competition aspects for Swedish onion and apple producer

As a member of the EU, Sweden has, in some cases, transferred the controlling rights to the Union. This means that the rules defined by the EU must be followed in all member countries, including Sweden. The European Agricultural policy constitutes the largest part of the EU's annual budget and is in contrast to many other areas fully funded at EU level. The last decade, many new regulations on chemicals and pesticides have been introduced which brought great changes and a lot of work throughout the Union, including Sweden. Sweden has always had a strict policy on chemicals and has been at the forefront when it comes to sustainable agriculture and environmental management.

Frigörelse av kvicksilver och metylkvicksilver till bäckvatten under olika perioder efter skogsavverkning :

High levels of Hg in fish in Swedish lakes have been a problem along time in Sweden. The major concern is production and accumulation of the most toxic form of mercury; methyl mercury (MeHg). Consequently, in about half of our 83 000 lakes fish contain concentrations above the recommended limit for human consumption of 0,5 mg mercury per kg fresh weight (most of it in the form of MeHg). Consumption of fish containing too high levels of MeHg may cause problems for both humans and animals. Three major sources of MeHg in surface waters are: 1) runoff from terrestrial areas, 2) deposition from the atmosphere, and 3) internal production of MeHg in lakes and streams. The aim of this study was to investigate the effect of clear-cutting on the concentration of Hg and MeHg into draining streams.

Miljökonsekvenser av dagvattendamm i Skebäck, Örebro : en fallstudie hur miljöpåverkan av en dagvattendamm intill ett Natura 2000-område kan bedömas

Stormwater is surface runoff water that originates from precipitation or snowmelt and that on hardened surfaces prevents to infiltrate the ground. In city areas stormwater can consists of major amounts pollutants and when reaching a lake or watercourse it can cause damages on vegetation and animals. Therefore it is important to treat polluted stormwater before it reaches the recipient. The municipality of Örebro have since the 90ies an extensive work with treatment of stormwater in sedimentation ponds. A new stormwater treatment project is planned in an industrial estate in Skebäck, Örebro.

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