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1999 Uppsatser om Ground water modeling - Sida 2 av 134

PWM Effekt Audioförstärkare

The purpose with the report is to show that it is possible to design a class-D amplifier, using a programmable FPGA mounted on a developing card from Xess and a H-bridge. The FPGA was programmed in VHDL which is the language the software from Xilinx use to implement a logical function into the FPGA The logical function corresponds to a modeling of the music signal and the modeling can be described as a comparator which compare the music signal with a triangle wave and as a out signal produce a pulse width modulated (PWM) signal. The report is also a review and evaluating of two different modulating technologies, AD- modeling and BD-modeling. A detailed part about how the H-bridge was designed and how it works. The result of this project is a working audio amplifier to a significant lower price than the products in todays market..

Bättre åtkomst till avverkningstrakter med anpassat marktryck från avverkningsmaskinerna

The global climate-change means increasing mean-temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged harvesting grounds was made.

Segmentering och klassificering av LiDAR-data

With numerous applications in both military and civilian life, the demand for accurate 3D models of real world environments increases rapidly. Using an airborne laser scanner for the raw data acquisition and robust methods for data processing, the researchers at the Swedish Defence Research Agency (FOI) in Linköping hope to fully automate the modeling process.The work of this thesis has mainly been focused on three areas: ground estimation, image segmentation and classification. Procedures have in each of these areas been developed, leading to a new algorithm for ground estimation, a number of segmentation methods as well as a full comparison of various decision values for an object based classification. The ground estimation algorithm developed has yielded good results compared to the method based on active contours previously elaborated at FOI. The computational effort needed by the new method has been greatly reduced compared to the former, as performance, particularly in urban areas, has been improved.

Translokation av större vattensalamander : -bevarandestrategi eller riskåtgärd?

This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.

Vattenbehov och olika system för vattentilldelning till nyavvanda grisar :

We all know that water is very important for both animals and humans. When we are weaning the piglets from the sow we must guarantee that the piglets can start to drink more water instead of sow milk. The first thing to check is always the quality of the water that is to be used. To secure that, you must take a water sample. If the water is inadequate it can bring a lot of problems and diseases.

Näringsämnesretention i fyra nyanlagda våtmarker i Falkenbergs Kommun

This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.

Översyn av vattenskyddsföreskrifter med tillhörande vattenskyddsområde i Hallstahammars kommun. : Vilka revideringsbehov finns?

Water is an important food and an important natural resource. In order to protect these are the Environmental Code and the EU directive given to water protection and related water protection regulations will be established for all water sources until 2010. Those who will prepare a water protection and related water protection regulations is the municipality or person responsible for water supply. The person then decides and declares the area as water protection and related water protection regulations are municipal or provincial government. The idea of creating a water protection is to protect the water supply and the body of water against pollution caused by point sources, diffuse sources and accidents combined.

Naturlig förekomst av arsenik och avskiljning av arsenik från grundvatten : test av olika filtertekniker avsedda för enskilda brunnar

During the last few years the presence of high arsenic (As) concentrations in ground water has been of major concern both internationally and in Sweden. Much evidence has been reported about toxic effects caused by arsenic. The carcinogenic effects and the possibility to measure the toxic impacts at low concentrations made the World Health Organisation (WHO) to reduce the guideline value from 50 to 10 ?g l-1 in 1993. In Sweden the corresponding reduction was implemented in 2003. Several surveys in Sweden have shown that high arsenic concentrations may occur in ground water.

Uran i dricksvatten : litteraturstudie om reningsmetoder samt pilotförsök med jonbytesteknik

Uranium (U) is a naturally occurring component in bedrock and under the "right" conditions it can dissolve and move into the ground water. Since many people in Sweden depend on drilled wells as their main drinking water supply, they may be exposed to the uranium in the water. Radioactive radiation is not the major concern associated with naturally occurring uranium. It is rather the chemical properties of uranium that make it a potential danger to human health. Uranium is proven to have toxic effects with respect to the functioning of the kidneys.

Användbarheten av Tekla i Betongkonstruktioner : En jämförelsestudie mellan två modelleringsprogram

This thesis has examined the Tekla Structures modeling software and answered the question of whether it could act as a suitable modeling program for the design department at Bjerking AB in Uppsala. The method used in this work is a case study of a previous project with existing basis to work form. The demarcation of the study was to examine only the usability of the foundations of in situ concrete. The work examined three main areas within the design process. The first was to model the concrete elements then to model the reinforcing and ultimately production of the drawings. Because Autodesk Revit was the existing modeling program in the Department conducted the evaluation as a comparison between the two programs.

Vibrationsproblem i närliggande konstruktioner i samband med markarbete

Ground work like blasting, piling and excavation has always had a great influence during the planning phase of a construction project since it can cause damages on adjacent buildings and have severe economic consequences. This thesis deals with how vibrations caused by ground work influence near-by buildings and what methods geotechnicians and construction entrepreneurs use to handle these risks.The purpose of this thesis is to explain risk management in relation to ground work. In order to achieve this I have used a qualitative method by interviewing a geotechnician and a ground work contractor who possess knowledge and experience useful to this thesis. The result shows that vibrations from ground work spread through the ground as seismic waves that cause displacements and packing in the ground visible in adjacent buildings as cracks and subsidence damages. Geotechnicians study ground work vibrations by means of ground investigations and experience from previous projects in order to produce a risk analysis that entrepreneurs can use to reduce damages.

Termisk Vattenpump

 This degree project aims at developing a concept for how to use solar energy to pump up water. The target audience is people living in areas where the functioning of the electricity and water network is absent. In these areas, the hand-powered water pump is the most common technology. The degree project's goal is to find an economically viable alternative to the time consuming hand-powered water pumps. The power comes from solar energy.

Design av utomhusträdgård i Dubai :

To plan and build a garden in Dubai has other conditions and challenges than what you experience in Sweden. The heat, wind and lack of water makes the need for durable plants, a good design and landscaping important if you want to have the opportunity to use your garden during most of the year. The soil is poor of nutrients, alkaline and sometimes saline, witch makes supplying the soil with organic material and various fertilizers necessary if you want to be able to plant a bigger range of plant material in your garden. Another important part is to provide your garden with a good irrigation system that should be put into the ground before planting so that the plants are given a more even irrigation. It?s relatively green scenery you meet and to me it?s in a way surprising since the country with its climate is rather harsh for the purpose of supporting plant life.

Utrymning av folkmassor - simulering och verklighet

The report contains a comparison between computer based modeling of evacuation and evacuation experiments with large crowds. Crowd movement, behavior and management is examined, as well as the evacuation time. The conclusions in this report are based on observations made during the evacuation of a football ground (Swedish)..

Vattenskydd och krisberedskap hos allmän dricksvattenproduktion : Skydd av täkter, tillgång till reservvattentäkter och andra nödvattenlösningar hos svenska vattenproducenter

The objective of this report was to analyse and compare vulnerability and preparation in Swedish municipal drinking water production, in case the commonly used water sources were inoperative. Methods used were a questionnaire and a less extensive study of regulations for water protection areas. The questionnaire was answered by 41 Swedish municipalities. A handful of them were companies co-owned by a few municipalities. Only one out of four municipalities had source protection areas to all their water sources and for many sources the protection was not satisfactory.

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