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605 Uppsatser om Surface cleaning - Sida 6 av 41

Dikesrensning och skyddsdikning : en fältstudie och utredning av behov i södra Sverige

During the 20th century a significant proportion (about 15 %) of the peat-covered wetlands in Sweden were drained to improve forest productivity. Area wise, most of the forest drainage was done in northern Sweden, but relatively speaking a larger part of the wetlands have been drained in the southern parts of the country. Most often, the forest drainage resulted in increased forest growth, but failures were not unusual, and harmful effects, e.g. on species richness, have been a common cause for draining. Ditch cleaning is necessary for maintaining the ditches in good condition.

Sammanvägda avrinningskoefficienter i rationella metoden : en jämförelse mellan idag och 1970-talet

Storm water is rain and melted snow that runs off, primarily from impervious surfaces.Future storm water management is facing the challenges of increased precipitation, asclimate changes, and increased areas of impervious surfaces due to the expansion anddensification of the cities. Impervious surfaces reduce the potential for water to infiltratein the ground leading to increased surface runoff and higher peak discharge.The runoff coefficient is closely related to the percentage of impervious surfaces andrepresents the maximum percentage of a catchment that can contribute to runoff. In thisstudy, the objective was to evaluate the weighted runoff coefficient for three differenturban types; apartment buildings, townhouses and residential areas and a comparisonbetween today and the 1970`s was made.The runoff coefficient was determined by manual mapping of the different surface typesin each area based on data in the form of orthophotos and aerial photographs. The surfacetypes that were mapped were asphalt, permeable areas, tiles, sand/gravel and roof.Tiles and sand/gravel were the most difficult surface types to map. In order to see towhat extent these categories influenced the weighted runoff coefficient a sensitivityanalysis was carried out and the runoff coefficient based on surface type was changed indifferent scenarios.The results of the sensitivity analysis showed that the surface types tiles and sand/gravelhad little impact on the weighted runoff coefficient which in mainly due to the fact thatthe percentage of these surfaces types of the total area is small.The result of the study showed that the largest change in the runoff coefficient occurredin residential areas where the increase in the percentage of impervious surfaces causedby new roofs in the form of porches and garages and from paved or tiled driveways.

Biogasprocessen : Bestämning av verkningsgrad

Biogas is increasingly used for fuel in for example vehicles and it´s produced in a biogas processconsisting of the steps of pretreatment, digestion and gas cleaning. The pretreatment is a method usedto increase the gas production and / or destroy pathogens. The digestion is the stage when anaerobicmicroorganisms convert bio-mass of a substrate to a raw gas containing about 65% of methane. Thegas cleaning is used to increase the methane content to about 97% so the gas can be used for motors invehicles. The biogas part of the Ekeby sewage plant in Eskilstuna is using multiple substrates.

Uppvärmd konstgräsplan : Beräkning av utnyttjningstid för en uppvärmd konstgräplan med alternativa rörplaceringar

For Skattkärr IF a turf field with warming has been projected to increase field?s utilization hours and to have a longer period for athletes to perform their activities outdoors. The technique chosen to heat the plan is a type of a geothermal heating system without a heat pump. The brine, which is water with 30% ethanol, collects heat from the borehole and discharges it to a coil in the field. There is at position 11 boreholes but it is planned to increase the number to 31, which is the design for the facility.

Shamyana, the out door pleasure

The present work is a continuation of the ideas developed in previous projects during my Masters studies that explored the relation between pattern, form and space. Starting from the pattern multiplication for space construction the present project proposes textiles as an assortment of flexible expressions. The purpose of the project is to explore aesthetic and functional potential of textiles for out door temporary structures. This is to create a pattern interface which filters sunlight through a textile surface to offer instant sheltering solutions for out door activities. The project combines research and analyses of outdoor temporary structures and scope of textile in the area.

Computer Modelling of the Influence of Surface Topography on Water Repellency and a Study on Hydrophobic Paper Surfaces with Partly Controlled Roughness

A computer model based on minimization of the free energy, capable to predict contact angles and spreading transitions between Wenzel and Cassie mode for drops placed on surfaces with different topography were implemented in matlab. Simulations were compared with experiments documented in the literature. These showed that reported transitions between Cassie and Wenzel mode can be explained by minimization of the free energy. In this report, a study on the possibility of constructing water repellent paper surfaces with a combination of treatment with octadecyltrichlorosilane and topography changes, is included..

Stump treatment with the root rot antagonist phlebiopsis gigantea : - sensitivity of P. gigantea spores to high pressure stress; - reduced water consumption for stump treatment

Stump treatment today requires large quantities of clean water mixed with the protective product Rotstop, to fully cover the stump surface. In order to reduce the water consumption without reducing the coverage of the stump surface, the pressure in the stump treatment device can be increased. Therefore, the Phlebiopsis gigantea (Fr.) Jül. suspension used as a biological control agent to prevent Heterobasidion annosum (Fr.) Bref. infection was pressure-tested.

Mekanisering av häststall

Mechanization of Swedish agriculture started in the beginning of the twentieth century, to be able to have more animals without raising the number of employers. The horse business has not by far kept up with these cost savings solutions. Cleaning out stables and feeding horses are the most time-consuming tasks in horse stables today. The most common way to clean out the stable is still by shovel and wheelbarrow. The clean out process can easily be mechanized through semi- permanently beds with movable walls between the boxes so that the litter can be removed by a tractor or a loader.

En jämförelse mellan TLS och UAV-fotogrammetri : Inmätning av hårdgjorda ytor

At present day there are several different methods for measuring of paved surfaces.The most common methods today are measuring with a total station, the GlobalNavigation Satellite System (GNSS) and terrestrial laser scanning (TLS). Recently thedevelopment of unmanned aerial vehicles, known as drones, has increasedexponentially and today there are several ways of using drones for measuring surfacesby photographing and laser scanning.This thesis contains a comparison between the methods terrestrial laser scanning(TLS), and unmanned aerial vehicle photogrammetry (UAV). The measurements havebeen applied on two different test surfaces, one of asphalt and one of gravel. Thepurpose of the comparison is to investigate whether the airborne photogrammetry isequivalent accurate in its height levels as the terrestrial laser scanning. For thecomparison to be more extensive, these two methods have not only been comparedin precision but also in the areas of ease of use and economy.The precision was analyzed by comparing the height levels in randomly placed controlpoints on the test surfaces.

Produktivitet och lönsamhet vid skogsbränsleuttag längs skogsbilvägar :

With an increased demand for biomass based energy and with development of better technique harvest biomass, new possibilities open up. With the possibility to combine traditional cleaning of road?s right of way with biomass harvesting, the work of suppressing tree vegetation could become profitable or at least decrease the road maintenance cost. However, knowledge about productivity and profitability in mechanical biomass harvesting in roads? right of ways are still limited.

"Guud, vad tråkigt." : Matematik och elevmotivation

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

I huvudet på en naturkunskapslärare : Elevernas intresse- problem eller resurs?

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Energy efficient storage of biomass at Vattenfall heat and power plants

Storage of biomass is often associated with problems such as heat development, dry matter losses and reduction of fuel quality. The rise in temperature can potentially cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles can cause health problems in the surrounding. The dry matter losses and reduction of fuel quality can have economical effects. The aim of this thesis project is to develop guidelines on how to store large amount of biomass at Vattenfalls heat and power plants in an optimal way.

Objektspecifik möbeltextil

My project aims to understand more about the methods used in making woven textiles on an industrial level, and how these tech¬niques can be adapted to create object-specific pieces. On visiting the furniture fair in Stockholm, I was surprised to see that most of the textiles used for furniture were so similar, despite the variation in the furniture itself. My project is about creating textile patterns that are specific for each piece.The idea behind the process could be used for any product, but the pattern I created is specifically for the armchair Accent by Yngve Ekström. I wanted to create the feeling of a pattern moving over the surface of the object and adjusting to it. I worked primarily with differences in density.

Varför sviktar elevers intresse för matematiki de högre åldrarna? : Vilka faktorer ger elever motivationoch lust att lära matematik?

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

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