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737 Uppsatser om Calculations of crack widths - Sida 43 av 50

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.

CE-ma?rkning av produkter under byggproduktfo?rordningen

The purpose of this study is to achieve an understanding of how a CE- marking process is conducted and to identify the relevant factors that must be considered in such a process. We have conducted our study at Lo?vhults Svets & Smide AB (Lo?vhults) in Skruv, Sma?land Sweden, which are manufacturing brackets for small covering constructions.To understand how a CE-marking process is conducted several documents and provisions have been reviewed to achieve a basic understanding and insight of the subject. It thus led to that guideline ETAG 015 were studied and the factors to be considered in the CE-marking of brackets were identified. Together with Jan-A?ke Johansson at Lo?vhults we agreed on four different brackets to investigate for a potential CE-marking.

Samhällsekonomisk analys av ett djupförvar för använt kärnbränsle i Forsmark :

This thesis investigates the socio- and environmental economic effects of a deep repository for spent nuclear fuel in Forsmark in the municipality of Östhammar. I seek to show the general picture but focus on the effects on employment, environment and income. Cost-benefit analysis is used to investigate the differences in utility between a scenario with and a scenario without a deep repository in Forsmark. Most of the possible effects can not be valued and many can not even be quantified with the data available today. Therefore this thesis has a bit of a ?preliminary study character? and seeks to show what we know today and what needs to be further investigated when available data allow it. The costs that could be valued are noise from the traffic during the period of building and emissions of carbon dioxide and nitrogen oxides from the transportation of rock masses during the building period.

Logistik för stråbränsle :

Summary Today energy prices are rising. As a result biomass fuel is getting more and more interesting. Wood chips is very popular, but also straw from grain production is on the table. Lunds Energi AB project a combined power and heating plant in Örtofta out of Lund. Wood chips is meant to be the main energy source, complemented by straw. In this thesis the transportation of straw for fuel is studied.

OMBILDNING FRÅN HYRESRÄTT TILL BOSTADSRÄTT  : En jämförelse mellan ett allmännyttigt och ett privat fastighetsföretag

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.

Evaluation of creditability and risk minimisation : The effect of accounting for intangibles

The recent history knows numerous examples of creditor?s inability to evaluate financial solvency of the client correctly. Creditors? risks do not only concern individual relations between the two parties but the economy in general. The standard loan-giving procedure considers evaluation based on a number of financial ratios.

Mineraliska material som reaktiva filter för avskiljning av tungmetaller från dagvatten

Highly polluted urban storm water from e.g. highways can contain large amounts of heavy metals that may cause harm if they are discharged into recipients. To remove the heavy metals a possible low-cost method that does not require much maintenance, could be the use of reactive filters with filter materials consisting of industrial residues or other cheap mineral based materials. Dissolved metal ions are removed by reactive filters through the processes of ions binding to active sites on the surface of the filter materials, or by formation of insoluble precipitates.The ability of CaO-treated granulated blast-furnace slag, iron oxide coated sand, olivine and nepheline to remove seven heavy metals (Cr, Cd, Cu, Ni, Zn, Pb and Hg) from urban storm water was studied. Initially batch experiments were performed where the effect of pH, dissolved organic carbon (DOC) and dissolved ions on the adsorption efficiency was studied.

Att möta sorg i arbetet : En kvantitativ enkätundersökning över begravningsrådgivare anslutna till SBF (Sveriges Begravningsbyråers Förbund).

This quantitative survey aims to highlight the impact of the meeting with the grief for customer advisers and representatives of funeral homes connected to the SBF (Sveriges Begravningsbyråers förbund). It also aims to demonstrate any differences between the sexes on this subject. Issues include: How does the person experience expectations and requirements in relation to their professional role? Does the person experience a personal impact due to the encounter with grief and death in their profession, in what way and to what extent? What consequences does the expectations, reactions and the possible impact result in for that person? What conditions does the person have to help cope with the professional role? Is there a gender difference in this experience? The theory base, which consists of theories taken from The Managed Heart: The commercialization of Human Feeling by Arlie Hochschild (2003) and descriptions taken from Yrke: begravningsentreprenör. Om utanförskap, döda kroppar, riter och professionalisering by Anna Davidsson Bremborg (2002), has been fundamental in both the preparatory work and the analysis.

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