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181 Uppsatser om First layer - Sida 12 av 13

EN TOTALKOSTNADSJÄMFÖRELSE MELLAN CELL-, SKUM- OCH LECA-BETONG

This report provides a comparison between the products cellular concrete, foam concrete and LECA concrete. The questions to be answered during the work is how the cellular concrete stands up in cost terms to the existing competitors on the market, how the concrete products differ in design work, and in which situations the concrete varieties are preferred to use.Cellular concrete is a variant of ordinary concrete, with the difference that the ballast is exchanged from stone materials to expanded polystyrene beads (EPS). This substitution gives a product with higher insulation values but lower weight than ordinary concrete.The work was carried out by designing a survey which was sent to two hundred randomly chosen companies across Sweden, to see the building industry?s opinion of the product cellular concrete. The survey showed that cellular concrete was equals its competitors in terms of price, while the product was said to be more flexible, quicker and easier to cast.Then some of the companies, who participated in the survey, were interviewed to see more carefully, how the price, the workmanship and the time for casting and dehydration differed between the products.

Trädslagsinverkan på markvegetationens utveckling i odlingsförsök med tall och contorta :

In the 1970?s it was predicted that in the beginning of the 21st century there would be a timber shortage in Sweden and a large scale introduction of the exotic tree species lodgepole pine started. An introduction of a foreign tree species means a risk of a negative influence on the forests ecosystem. Today, the stands that were established in the 70?s are middle-aged and the effect on the forest floor vegetation can be studied.

Biogaspotential hos våtmarksgräs

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).

Geografiska informationssystem för studier av polyaromatiska kolväten (PAH) : undersökning av djupvariation i BO01-området, Västra hamnen, Malmö, samt utveckling av en matematisk formel för beräkning av PAH-koncentrationer från ett kontinuerligt utsläpp

At the end of August 1999, the local government council of Malmö city decided thatthe area known as Kvarteret Bilen would be made available for the European HousingExhibition 2001 (Bo01-mässan). Kvarteret Bilen extends over approximately 80hectars and includes the western parts of the Western Harbour area (Västra hamnen)of Malmö.Kvarteret Bilen as a whole, but especially the western sections of this area, the socalledBo01 section, has been the subject of heated discussions. This is mainly due tothe fact that the ground in question has proven to be contaminated to a certain extentby different chemical compounds. Investigations undertaken during 1998 showed sporadically high concentrations forespecially one chemical group: polycyclic aromatic hydrocarbons (PAH).The first part of the paper describes the use of a mathematical equation (Fetter 1994)to calculate the concentration of PAH from a continuous discharge at a given time byemploying Geographical Information System (GIS). Even the constraints of theequation are discussed, as well as the consequences that follow as a result of usingGIS.The second part of the paper focuses on the connections between the content ofcarcinogenic PAH in Kvarteret Bilen and the ground water level and type of fillingmaterial.

Kartering av markföroreningar inom Skutskärs Bruk samt utvärdering av spridningsrisker enligt Naturvårdsverkets MIFO fas 2

With the prospect of future construction on the Skutskär Pulp Mill property, Stora Enso Fine Paper has initiated an investigation of soil contaminants and a risk assessment of these contaminants. A soil and groundwater investigation has therefore been conducted on an open area of about 16 000 square meters, situated between the current wood room and digester house. To be able to integrate this study into an investigation for the whole industrial property, the study has been carried out as a phase 2 study according to the Swedish Environmental Protection Agency?s Methods of Inventories of Contaminated sites (MIFO).The site investigation has involved soil and groundwater sampling, together with the analysis of heavy metals and organic contaminants. The degree of hazard posed by the contaminants, the level of contamination, the potential for migration of the contaminants, as well as the degree to which protection of human health and the environment is required in the area, have been weighed together for an overall risk assessment of the area with regard to human health and the environment.The investigated area was built up by filling in the coastal waters.

Prästgårdsträdgårdar : barndomsskildringar från 14 prästgårdsträdgårdar i Växjö stift

Few rectory gardens are today remaining in their former design and the cultural heritage that they represent are disappearing. Since 1987-88 the parishes are no longer bound to keep housing for their priests, which means that they, for economical reasons, are starting to sell their rectories. With this in mind, a group of people, growing up in rectories in Småland and Öland between the 1930th and 1950th, formed an interest group to save the memory of their rectory gardens. On the basis of their memories, they have written a couple of descriptions of the rectories, which describe the gardens content, design and the life they once lived there. With this compilation of the 14 rectory gardens I want to keep the memory of them and create a ground for future work in this field. Historically the rectory gardens played an important roll as patterns and examples in the countryside.

Att återställa en naturlig ordning : skogshistoria och restaureringsbränning i Långsidbergets naturreservat

During the late 1800s fire suppression became increasingly effective in northern Sweden which led to decreased areas of fire-disturbed woodland and successive changes in the structure of forests. In the long run this can pose a serious threat to fire-dependent and fire-favored species. Today some fire-prone forest reserves are burned as a nature conservation act. Often partial cuttings are made before burning, with somewhat different motives. The purpose of the study in Långsidberget nature reserve was to give a general picture of forest history and its affect on today?s forest condition, and to show how partial cuttings affect burning conditions and results. Långsidberget is located close to areas that were colonized during the Middle Ages.

Echinococcus multilocularis immunomodulatory strategies in the intermediate host

Echinococcus multilocularis är en helmint med indirekt livscykel. Parasiten lever i tarmen på sin huvudvärd, framför allt räv, som utsöndrar ägg med faeces. Äggen tas upp av en mellanvärd, migrerar till levern och utvecklas där till ett larvstadium kallat metacestod. Mellanvärdar är framför allt vilda smågnagare, men även andra djur inklusive människor kan infekteras. Hos mellanvärden ger E. multilocularis upphov till en sjukdom kallad alveolär echinococcos.

Skattning av den integrerade hydrauliska konduktivitetens variation kring Tunåsens infiltrationsanläggning : En utredning av påverkan från möjliga osäkerheter i befintlig information

Estimation of the variation in the integrated hydraulic conductivity around the Tunåsen infiltration facility - An investigation of the effects of uncertainties in existing informationAlmost half of Sweden?s drinking water volume is produced from groundwater. The main fraction of this is extracted from eskers, some of which allow for very large extraction rates. Despite this, the groundwater volume is not sufficient in some areas. This has led to an extensive use of artificial recharge.In Uppsala, the total volume added through artificial recharge is divided between four infiltration facilities.

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.

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.

Effekter av spädningsvätska på motilitet och fertilitet hos hingstsperma : en jämförelse av subjektiv motilitetsbedömning och QualispermTM

At SLU, Divison of Reproduction, Dept of Clinical Science, there is an ongoing project on the development and evaluation of new methods for the assessment of stallion semen quality. This EEF-study, which is a part of that larger project, has focused on the effects on motility and fertility of stallion semen of two different extenders and selection. Both an objective method and a subjective method for analysis have been used and compared in the study. The increase in the use of artificial insemination with cooled semen in Swedish horse breeding over the last decade is thought to play a part in declining foaling rates (Kareskoski et al, 2006, Kuisma et al, 2006). This calls for better evaluation methods of semen quality since cooling and transportation put higher demands on semen quality in order to maintain fertility (Aurich, 2005).

Geosynteter för hållbara vägar : Modell för jämförelse av vägöverbyggnader med eller utan geotextiler och/eller geonät

The different material layers as part of a road construction fill all a function so theroad becomes durable, safe, comfortable and aesthetically pleasing. Recently, anew group of construction materials started to play an important role in roadconstruction ? geosynthetics.This thesis addresses the two most common types ofgeosynthetics used in modern road construction, namely geogrids and geotextiles.The most common use of geogrids is reinforcement of poor subgrade by usinggeogrid soil reinforcement, which occurs when road material particles wedge inthe geogrid?s mesh. Geotextiles act partly as a barrier that prevents the finermaterial in the below ground from being mixed with coarser upper material andalso act as a load spreader.Road contractors often face a choice of whether geogrids and/or geotextiles areappropriate in a particular road project and also how much profit the choice mightbring. This phase in the tender calculation process is the intended scope of thisthesis.The thesis deals with both the "hard" cost-function aspects and the "softer" values e.g.

Potentiell fosforfrigörelse från sedimentet i Bornsjön, sydvästra Stockholm : The potential leakage of phosphorus from sediment in Lake Bornsjön, south western Stockholm

Lake Bornsjön is situated 30 km southwest of Stockholm in a rift valley lake and consist three basins outstretched in northwest-southeast direction. The surface area is 6,7 km2 with a maximum depth of 18,3 meters, a mean depth of 9,8 meters and a retention time of the water of 6,5 years. The drainage area is 42 km2 and consists mainly of arable land (ca 1000 ha) and productive forestry land (2500 ha), but in the drainage area there are also restored and fairly newly constructed wetlands.Today the Stockholm area receives its drinking water from Lake Mälaren, but if there would be any pollution of this source, Lake Bornsjön would act as the water source. The area surrounding the lake was bought already in 1899 by Stockholm Stad for protection of the lake and was taken over 1993 by Stockholm Vatten AB. It has been a water protection area from 1988 and it was also accepted as a nature reserve in 1995.

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