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120 Uppsatser om Hydraulic conductivity - Sida 6 av 8
Soil carbon in small-holder plantain farms, Uganda : a comparison between agroforestry and non-agroforestry
Smallholder farmers in Uganda suffer from declining productivity. With a rapidly increasing population, marginal land is taken into production and the current land
management leads to loss in soil fertility and escalation in soil erosion. There are studies indicating that the use of agroforestry increases soil organic carbon (SOC)
compared to systems without trees. Soils which are high in carbon have many advantages, for example better water holding capacity, which can reduce stress on
crops during drought.
The aim of this study was to determine the effect agroforestry has on SOC concentration in small-holder farming systems in Uganda. The intended system to
study was farms practicing agroforestry methods or not in intercropped plantain (cooking banana) fields.
Vallört som växtnäringskälla : växtnäringsförsök och litteraturstudie
Russian comfrey, Symphytum x uplandicum, was tested as a plant nutrient source in a trial with tomatoes. Comfrey liquid was produced by Stiftelsen Holma i Höör. Tomato plants of the cultivar Aromata planted in a medium of soil:peat (1:1) enriched with organic nutrients and lime, were fed with comfrey liquid plus Biofer, in three different concentrations. Two different concentrations of BioRika were used as comparison, along with an unfertilized control group. In the comfrey treatment I a total amont of 1g N, 0,23 g P, 0,84 g K, was given to the tomatoes.
InsuFlex : Framtagning och analys av högpresterande isoleringskoncept i sandwichelement
Rapportens huvudsyfte är att ta fram en isoleringskombination av högpresterande material, som ska bidra till ett förbättrat U-värde och reducerad väggtjocklek. Konstruktionen är baserad på en befintlig sandwichvägg från Strängbetong, där författarna ersatt den ursprungliga isoleringen med det utvecklade isolerskiktet för att slutligen studera väggarna med lika villkor. Den framtagna väggens isolerings- förmåga presenteras genom handberäkningar, där det erhålls U-värde och temperaturfördelningar mellan elementens olika skikt vid stationära förhållanden. Det har även utförts värmesimuleringar för att analysera samma fysikaliska faktorer dock baserat på 3D förhållanden.I samarbete med företag har flera högpresterande isoleringsmaterial valts ut att ingå i väggkonstruktionen. Genom fördjupade studier av materialens fysikaliska egenskaper kunde en komplett isoleringskombination utvecklas och fick namnet InsuFlex.
Brunnsviken : Utvärdering av åtgärder för förbättrad vattenkvalitet
Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin. The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.
VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor
Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.
Geotermisk fjärrvärme i Gunsta
Gunsta is situated about 10 km east of Uppsala. Today there are plans to establish 1000 new households in Gunsta before year 2030. The required energy for heating houses and water would be distributed via a district heating system, which also includes 200 existing residences. The annual required energy, according to this study, would be 16.2 GWh with a maximal peak effect of 6.9 MW.
To meet this need, the study suggests a system with heat pumps to upgrade the 31?C water from a 1.8 kilometre deep borehole.
Analys och utveckling av boggi till ramstyrd dumper
Volvo Construction Equipment is one of the worlds largest manufacturer of heavymachinery. In Braås, Sweden, they develop and manufacture articulated haulers inseveral sizes. The biggest, the A40, is capable of loading almost 40 metric tonnes.These haulers have a bogie to distribute the forces of the load evenly onto the two axlesand there wheels. The bogie is constructed using a rigid balance beam on each side ofthe frame connecting the axles or an independent solution using hydropneumatics.An analysis has been made in order to establish the forces created during corneringand through the theory, an estimation of the extensive tyre wear and extra fuelconsumption has been made. All due to the effects of the tyres not being inline with thecornering radius.
Utveckling av programvara till ett inbyggt styrsystem
This thesis considers the development of the software for an, newly developed, embedded real-time control system, based on a Periferal Interface Controller (PIC). The control system is developed to be used for several different applications. In this thesis work, software for two different applications are developed. The first task is a time controlled system, while the other task is implementation of aPI-/PID-controller. A user interface is also developed and implemented.The time controlled system is an automatic horse feeder, which is used for feeding horses at certain predefined points in time.
Utveckling av nytt koncept till processmaskin
Metso Paper offers a front-running range of solutions and services for the pulp and paper industry. At the baling unit, design solutions are developed for manufacturing and handling of pulp bales. The machines are continuously developed to satisfy customer needs. One big step in the development of the baling line was to remove hydraulics from the machines and replace it with electrical motors and pneumatics. This was not done on the folding machine which is still driven by mainly hydraulics.
Översvämningsrisker längs Funboån
Flooding events are no longer rare, floods occur all over the world. Accordingly, it is vital for the society and different authorities to work with flood mapping. To meet the goal of Uppsala kommun to map the risks of floods in Uppsala län, a map of the different areas around Funboån which are inside the area of risk for flooding have been developed.In the work, cross sections and the water flow have been measured. Moreover, an echo-sounding have been carried out in Funboån to map the bottom topography. From the bottom map and laser scanned data covering the study area, a terrain model was created.
Undersökning av deponerat ferrokromstoft : Utvärdering av ny behandlingsmetod
The production of ferrochromium alloys at Vargön Alloys AB contributes to formation of unwanted ferrochromium dust, which contains toxic Cr(VI). The dust is since summer 2005 treated with an iron-sulphate solution to reduce Cr(VI) to the non-toxic Cr(III). A year later the treatment technique was improved and disposal occurs in cells on the landfill. The cells can be up to 300 m3 and the edges can be made out of fro example concrete. Tests are conducted on the treated dust when it is disposed.
Bestämning av dagvattenflöden i Knivstaåns avrinningsområde
The purpose of the thesis was to map the hydraulic load on the Knivsta river from stormwater runoff, and build a platform for further studies of pollution loads on the rivers ecosystems. New residential areas are planned to be built in Knivsta municipality and it will have an impact on stormwater flows to Knivsta river. To examine the impact this will have, simulations were made in the area as it stands today and after expansion work. The work includes calculation of flows from the populated areas but also from the catchment area around it consisting of woodlands and fields. Because of expected climatic changes which may affect rainfall, the simulations have been performed with different return periods for rainfall data.
Konstruktion av truckmonterad hjulhanterare
GBD-Storage Systems is a company that provides the industries with products for efficient storage.The company produces pallet racks and accessories like cassettes and extending units. The companyhas also supplied tire racks for a number of tire companies. The company's CEO Gunnar Berglund hasfor some time had an idea to improve the working situation of the workers on tire firms by allowingthe wheels to be handled by a counterbalance truck. The current situation poses numerous heavy liftswhen the tires are handled and therefore is hurting the workers.This thesis has been aiming at helping the GBD-Storage Systems by developing a concept of howan accessory to counterbalanced trucks can be designed to cope with the wheels. This concept willthen be produced as prototype by the company.
Järnets förekomst i grundvattnet i isälvsavlagringar i Dalarna : Bakgrundshalter och rörmaterialets inverkan vid grundvattenprovtagning
A study has been performed that investigates the variation of iron content in groundwater.The study was initiated by Midvatten AB, which noticed that the iron content in groundwater samples can vary greatly over small distances. The purpose of this study was to geochemically and geohydrologically determine the factors that influence the content of iron and manganese in groundwater from a selection of eskers in Dalarna, and determine how to best sample groundwater with the method used by Midvatten AB. An evaluation was made of how the vertical variation in soil material, water composition, pumping time and pipe material affects the content of iron in groundwater. Piper diagrams were used to study the relationship between the chemical composition of the groundwater and the content of iron and manganese in groundwater samples from the studied areas. The groundwater from the studied areas was then classified in the Piper diagrams, according to the content of the major ions.
Wobblerpump
The task was to design and manufacture a submersible displacement pump working with the wobble plate principle. The main task for the Wobble plate pump is to be used as a sewage pump for smaller households or dewatering pump in environments where small flows and high pressures are acquired. For these purposes ITT Flygt sell a screw pump, PC-Grinder 3068. The hydraulic part of the PC-Grinder is manufactured by a subcontractor. Therefore ITT Flygt wants to evaluate an alternative to their screwpump PC-Grinder, which can be entirely manufactured by them self.