Sök:

Sökresultat:

1847 Uppsatser om Ground water - Sida 16 av 124

The effects of Gotland pony grazing on forest composition and structure in Lojsta hed, south eastern Sweden

Livestock animals affect their environment in a number of different ways, mostly through grazing and trampling. This study focused on the effects of Gotland pony grazing on forest structure and diversity, and the impact on ground cover. To compare the fenced and grazed area with a reference area outside the enclosure a number of transects were used. The study showed that there was no significant difference in height structure and diversity between the compared sites; however, there were a significantly higher proportion of damaged trees inside the enclosure. The ground cover variables showed a higher amount of bare soil, plant litter and wood-rush (Luzula sp.) inside the enclosure whilst grass was more frequent in the reference area.

Wallenius waters AOT luftrenare

This bachelors thesis was made forWallenius Water AB to develop a basisfor an Airpurifier prototype. Wallenius Water isone of the world's leading environmentaltechnology companies engaged inchemical-free water treatment based onUV-radiation. The thesis aim was toproduce a basis for a prototype that canbe used in three applications:Standalone, RAS systems and ventilationsystems. The work includes anintroductory description of the theorybehind AOP technology based on aliterature review on the subject. Asurvey of products currently on themarket and a product specification hasbeen used as the basis for thepreparation of a number of concepts inthis report.

Development of green space in Dar es Salaam, Tanzania

In Dar es Salaam, as in many cities in developing countries, green areas are decreasing due to the fact that the growth of buildings, infrastructure and services has become a priority. As the population increases more buildings and infrastructure are needed and much of the building activity takes the form of uncontrolled settlements, which encroaches the public green space. Dar es Salaam has approximately three million inhabitants, of which about 70 percent are living in informal settlements. The aim with this study is to make a design proposal for a park and recreation area where the Msimbazi river basin in the centre of Dar es Salaam is today. The basin consist of a few playing fields, footpaths and some urban farming, but apart from this it mostly consists of unused grasslands, swamps and forests. Because it is an unsafe place and badly connected to the rest of the city infrastructure, it has become a barrier. The annual flood combined with the constant still shallow water creates a good breading ground for malaria mosquitoes.

Jordlöparfaunan i bestånd av contortatall (Pinus contorta) och svensk tall (P. sylvestris) 1987 och 2010

In the 1970´s the North American lodgepole pine (Pinus contorta) was introduced to Sweden in large scale. The lodgepole pine affects its new environment different from Scots pine (P. sylvestris), leading to a change in biological diversity. Forestry today affects the ground beetle fauna (Carabidae). Habitat specialists associated with older forests are first affected. When the canopy closes again after a clear-cutting species that prefer open habitats reduces and those who prefer mature/closed forests increase. In this study we compare differences in diversity and community structure of ground beetles in stands of lodgepole pine and Scots pine.

Skalkonstruktion : Med inriktning mot hållfasthet och dämpning av ljud

The sound part is mainly practical and is dependent on concepts that have been tested through measuring with a sound level meter. The design part is more theoretical and has been verified with CAD models and finite element analysis.With a sound damping hood on the compressor the sound level is reduced with up to four dB. An optimized absorbent for the compressor space gives a reduction with three dB. By using the insulation for the heat water tank as absorbent we can see a sound reduction on the lover octave bands. A reduction like this is elsewhere hard to achieve as at it requires thick absorbents.By changing the today?s insulation to the heat water tank to a form of polystyrene polymer insulation the weight from the heat pump above can be transferred to the stable heat water tank.

Removal efficiency of perfluoroalkyl substances (PFASs) in drinking water : evaluation of granular activated carbon (GAC) and anion exchange (AE) using column tests, and the effect of dissolved organic carbon

Poly- and perfluoroalkyl substances (PFASs) are a group of environmental contaminants that have gained increasing attention due to their potential to bioaccumulate, environmental persistence and potential toxicity. PFASs have been found in surface water, sediment, air, soil, sludge and ice caps globally, as well as in wildlife and humans. Furthermore, PFASs have also been detected in drinking water, leading to raised concerns for human health, since drinking water is one of the most significant sources of PFASs for the general population. Conventional water treatment techniques have shown to be ineffective removing PFASs, highlighting the importance for further research to develop efficient removal techniques. The aim of this study was to investigate the removal efficiency of PFASs in water using two treatment techniques; granular activated carbon (GAC), type Filtrasorb 400®, and anion exchange (AE), type Purolite A-600. Additionally, the effect of dissolved organic carbon (DOC) on removal efficiency was studied.

Förutsättningarna för ett parallellt generation IV system vid svensk nybyggnation av kärnkraft.

A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.

Klimatförändringars påverkan på kulturmiljöer i Uppsala stad ur ett geovetenskapligt perspektiv

Cultural heritages are environments created by humans that are considered to have a conservation value for the posterity. They can be seen as one of society's non renewable resources. It is important to have knowledge of how cultural heritages are affected by future climate changes.The water flow in Uppsala is estimated to increase during winter and decrease during spring and summer. Precipitation will gradually increase as well as the intense short period precipitation. The average temperature is estimated to increase as well.

Projektering av småhus med solvärme som huvudkälla

In this report a study has been done regarding different heating systems on which are the mostcomprehensive with solar heating systems. The report has also been focusing if solar power can beused as a primary heating source for supplying more than 50 % of the buildings total heatingproduction. The University of Dalarna constructed a demo-house for this purpose and according tocalculations the total solar usage is more than 50 %. This house has been made for referenceregarding the design of the heating system of property 5:37.Further studies have been made to compare different heating systems that are compatible with asolar system, where the compared systems purpose is to be independent of direct using electricity. Asystem of this design is regarded as sustainable according to environmental as economic issues.

Avbördningsekvationer för sjöar utan vattenföringsmätningar

Stage-discharge equations for lakes without disharge measurementsSimon AnderssonIn 2015 all lakes, rivers, coastal water and groundwater should be of good ecological statusaccording to the water framework directive from the European Union. In the process ofimproving the quality of Swedish water bodies, knowledge of where problems occur isneeded in order to utilize the resources optimally. The ability of lakes to store water is animportant factor since it controls the flow of water through the country. A stage-dischargeequation is a mathematical relation between discharge from a lake and its water level. Bybetter understanding of stage-discharge equations for lakes, their storage capacity can bedescribed better in hydrological models.This master thesis aims to evaluate methods for determining stage-discharge equations forlakes where a variable amount of field measurements is available.

Aktivt system för tidvattenreglering av Lysekilsprojektets vågkraftsteknik

This report investigates a possible solution to the problem with adapting wave powerplants to work in countries with tidal water. The wire connecting the buoy at the surface with the generator at the bottom needs to adjust to the varying water depth. Our solution to this problem is to attach the wire to a jack which is then placed inside the buoy. The jack is then powered by an electric engine. The report discuss what forces the buoy will be exposed to and then the structural integrity of the design is evaluated through simulations.

ENERGIÅTERVINNING I GRANSHOT® - PROCESSEN

Uvån Hagfors Teknologi AB (UHT) has developed a process ? GRANSHOT® ? for quicksolidification of metals in water baths. In the process liquid metal is splintered ? granulated ?into small drops. The drops are rapidly cooled in a water bath where all the heat energy from theliquid metal is transferred into the water.

Koldioxidavgång vid ekologisk odling på organogen jord

The background of this work is the media discussion about the effect of cultivation on peatsoils on greenhouse gas emissions. It has been argued that row sown and intensivelycultivated crops such as carrots are more likely to emit carbon dioxide than for example grassleys. The association KRAV (an association promoting organic farming) shall, from this yearadapt their environmental policy to be more climate smart and have asked the question if thecultivation of some crops is more climate smart than others? Carbon dioxide emissions fromsoil are due to degradation of organic material and the rate is controlled by microbial activity.The microbial activity is determined by a variety of factors such as temperature, soil organicmatter quality and water content. I have measured the carbon dioxide emission from fourdifferent crops at two different farms.

Kläder i hampa - ett miljövänligt alternativ/komplement till bomull?

Hemp has been used for textiles for a long time in history until it became illegal to grow in many countries in the 1930s. It is interesting from an environmental point of view because it doesn?t need any pesticides and in most locations it doesn?t need any irrigation either, compared to cotton, which normally requires big amounts of both pesticides and water for irrigation. Hemp is a bast fiber, which means that the fibers are located on the bast of the stem (on the outer layer of the stem). Therefore they cannot be spun directly, they have to be removed from the stem first.

Sand pits as habitat for ground beetles (Carabidae) : does the area affect species number and composition?

Sand pits are a valuable habitat which can hold many sand living species including several endangered ones. As many sand habitats with exposed sand are declining, sand pits have a potential as a substitute habitat. This study was conducted to see what effect the area of a sand pit has on species number and composition of ground beetles (Coleoptera: Carabidae). Also, the effects of other environmental variables were tested, for example the proportion open sand, vegetation cover, sun exposure and tree cover. The study was conducted in the county of Uppsala in 2008 and included 13 sand pits with areas between 200 and 180,000 m2.

<- Föregående sida 16 Nästa sida ->