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713 Uppsatser om Calculations - Sida 41 av 48
Surhetstillståndet i bäckar uppströmskalkdoserare i Dalarnas län
The acid deposition of sulphur- and nitrogenoxides from combustion of coal and oil cause acidification that lowers pH and gives increased contents of metals and altered aquatic biodiversity in the stream. The liming of lakes and streams, which was introduced to resist the acidification, demand large economic resourses despite of the decreased deposition of the acidifyng substances. Some of the streams are influenced by the acid deposition, while others are naturally acidic. It is therefore importaint to separate the anthropogenically acidified waters from the naturally acidic, in order to optimize the use of governmental fundings for liming. This thesis aims to estimate the acidity status and impact of acidification on 24 catchments upstream liming dispensers, which is part of the liming activities at the County of Dalarna.The acidity status of the streams was classified according to the Swedish Environmental Protection Agency old classification system (Naturvårdsverket 1999) as very acid to acid, with small ability to withstand a pH-change (alkalinity) due to acid deposition.
Internetmarknadsföringens effektivitet : en studie på fyra utvalda former av Internetmarknadsföring
The society is developing fast and the development is constantly on-going, new technology results in new opportunities and new problems for both companies and consumers. The use of Internet has heavily increased around the world; this means that the companies can use Internet as a channel of communication to reach the consumers. The most recent type of marketing is web marketing. The fact that web marketing is constantly changing raise the question of how effective different types of web marketing are.The purpose of this study is to investigate four selected types of web marketing. This is achieved by comparing the response from the consumers and the cost for the different types of web marketing.
Planering av vägupprustning med hjälp av GIS och optimering : en fallstudie på Holmen Skog
The objective of this thesis was to develop a method for the planning of road upgrading at Holmen Skog, a Swedish forest company. A critical issue for creating such plans is to identify roads that are suitable to upgrade to a standard that can handle heavy traffic during spring thaw, since spring thaw is a bottle neck for transporting timber. The method was tested in a case study at a district.
The work consisted of two parts. The first was to retrieve and prepare geographical data for the roads.
Privatskogsägarens nettoinkomst vid avverkning under perioden 1952-2008
During the period 1952-2008, real prices of wood before taxes and charges declined. However, the actual net income has not changed by the same percentage as the price list, because taxation, driving costs and the ability to make deductions has changed. This report considers the inflation by using the Swedish consumer price index. Net income refers to the remaining income when relevant costs, taxes and fees have been paid.The purpose of this study was to examine how the private forest owner's real net income has evolved over the period 1952-2008 for three categories of forest owners. These three categories are1.
Optisk undersökning av dieselsprayer från en höghastighetsroterande insprutare
There have been changes in Earth?s climate system on both global and regional scale since the pre-industrial era and some of these changes are due to human activities such as the combustion of fossil fuels. This calls for the development of engines with a higher efficiency and less harmful emissions. One interesting concept is the Homogeneous Charge Compression Ignition (HCCI) engine, which has the advantages of potentially low emissions combined with high efficiency. However, HCCI with diesel fuel requires a relatively long fuel/air mixing time to ensure a "homogenous" charge.
FEM?modeller för expansionsanalys av piplines
REINERTSEN AS performs expansion and buckling analyses of pipelines using ANSYS, afinite element modelling and analysis tool. In an expansion analysis the pipeline is modelledwith thin?walled pipe elements called PIPE20 which allows plastic deformation. However, ina recent analysis the results retrieved from the PIPE20 element were incorrect for strainsabout 1 percent. One main issue was that the PIPE20 element overestimated the strains.The purpose with this Master Thesis was to become familiar with the theories and analysismethods used in pipeline design.
Timeliness cost for agricultural sprayers : weed control in cereal crops
Evaluation of machinery costs is necessary for selecting appropriate farm machinery. Timeliness cost due to untimely operations is an important component of machinery costs. Timeliness costs can be high for crop sprayers, since pesticide application must be carried out within a short time interval. This Master thesis investigated the timeliness cost and the probability of a suitable workday for spraying. Timeliness factors were estimated for four different crops (oats, spring wheat, winter wheat and barley) using historical weed trial data.
Prefabricerade passivhusväggar
Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments.
Delta X : Utveckling av värmeväxlare
Stockholms vattenskärning AB in Kungsängen has through the acquisition of a company begun to design and produce aircraft heaters whose origin is early 1970s which follows a high inefficiency in terms of energy consumption and size.The aircraft heater, which is sold worldwide, serves its purpose for customer satisfaction and has done so ever since it was developed in the 70s.Stockholms vattenskärning AB is now investigating the possibility in making the aircraft heaters more efficient, both in terms of energy consumption but also on a more efficient design with the belief that it would lead them to an edge in the market. The aircraft heater consists of several main components whose function altogether is to keep passenger aircrafts warm while they are on the ground.This project has been limited to the further development of the heat exchanger package which accounts for the conversion of the hot medium to the fresh air being carried in to the aircraft cabin. Work has been divided into different phases in order to create a better understanding of the project range and to make it easier to divide the various elements in the time available, 10 weeks. These phases are literature review, situation analysis, concept generation, CAD, concept comparison and writing reports.After the initial literature review was made, a fundamental theory was written which is essential in understanding the remaining parts of the project.With the theoretical part as support, measurements and Calculations were made on the current heat exchange package in a situation analysis to ensure its operation and efficiency.In the concept generation phase, the collected facts from the literature review was used as the basis for creating a matrix. The purpose of the matrix was to indicate the two most suitable types of heat exchangers to develop four new concepts out of.In the CAD phase the four concepts was drawn up and then described with text and images.The last phase is the concept comparison where a concept selection matrix is used to function as a decision basis for further production at Stockholms vattenskärning AB. The four concepts have been developed based on the current heat exchanger and is gradually changed into a design of a cross-flow heat exchanger constructed out of stainless sections. The purpose of this is to have gradual upgrading of the heat exchanger as an option, in order not to saturate the market..
Deep Green i oceana strömmar - en konceptstudie
With growing economies and better living standards in many parts of the world today, there is a need of expanding the capacity of generating electricity. The alternatives for renewable energy technologies are not fully developed and have still some problems to conquer.The company Minesto has developed a technology that is called Deep Green. It is designed to gain electricity from tidal currents. Deep Green works in a similar way as a kite that is attached to the seafloor with a moving wire. It contains of a wing that moves due to the water current.
Dammsäkerhetsanalys via stabilitetsberäkningar för Långströmmens kraftverk : En jämförelse mellan olika dimensioneringsmetoder
A detailed dam safety evaluation (in Sweden called FDU) was performed in 2009 by WSP where stability control was performed for Långströmmen power plant with associated spillways. This evaluation concluded that stability could not be ensured, and risk of sliding occurred. The evaluation is based entirely on the recommendations outlined in RIDAS, the power companies guidelines for dam safety, and it is clear that extensive renovations are necessary to stabilize the dam.In this work, the stability will also be checked with guidance through new proposals on guidelines for concrete dams sliding stability, ELFORSK?s report 08:59. This report considered the guidelines in RIDAS as oversimplified, both from an international perspective, but also with regard to the current state of knowledge regarding dam safety.
Nollföljdsmodellering av transformator-Beräkningar av följdproblem vid ökad kablifiering på mellanspänningsnivå
Historically transformers with system earth equipment have been modeled as open circuits in zero sequence. This approximation has been satisfying, but lately it has been discovered that equipment on one side of the transformer have responded to faults that occurred at the other side. Most of these problems took place when the majority of the system on the secondary side of the transformer contained cables. These findings have led to questioning whether or not the former model of the transformer in zero sequence is correct. This report investigates if it is necessary to represent the transformer in zero sequence in another way than it is usually done today.
Solvärme på Utö
The guest harbor on Utö, Utö Gästhamn, is currently using electricity for heating all of the water used in the showers and taps. Because of the large amount of visitors, especially during the summer months, the hot water usage gets very high and that is also the case for the electrical bills. During the year of 2011 the cost of electricity for Utö Gästhamn reached a total of 257 500 kr. Out of these 257 500 kr approximately 142 000 kr, 55 % of the total cost, were because of the water heating.The report is the result of a cooperation with Skärgårdsstiftelsen, the Green Islands-project and Utö Gästhamn where the mutual goal is to dimension a solar energy system, to promote the sustainable development.Initially the different techniques for the solar energy system are researched. The techniques are plane solar collectors, evacuated tube collectors, pool collectors and photovoltaic cells.
Nitrogen flow in Scania : substance flow analysis on a regional level
In this thesis, the flows of reactive nitrogen (Nr) in Scania were investigated and quantified. The thesis was also intended to form a basis for comparison between the urban nitrogen flow and other flows of nitrogen within Scania. The management of nitrogen in society has disturbed the natural nitrogen cycle. This is linked to a series of environmental problems such as eutrophication, acidification, global warming and smog.
The method used was Substance Flow Analysis (SFA) for Nr. For calculation and flow charts Scania was divided into three subsystems; air, water and society.
Design och utveckling av monteringsverktyg
With this essay we want to describe the transformation process that the real estate owner has to go through to sell the current rented flats to tenant. We also want to provide an understanding how the valuation is performed in the transformation process and highlight the issues that affects the price in the valuations. In the essay we would like to see if the valuation and the transformation process differ in a public real estate company compared to a private real estate company. Based on this we have asked us the following question to answer: -Is there any differences in how real estate?s are valued in the transformation process between public real estate companies and private real estate companies? We have used a qualitative approach to keep our main question.