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4324 Uppsatser om Calculations model - Sida 7 av 289
Analysmetoder för rörsystem
The purpose of this thesis work is to evaluate how the physical behaviour of a pipe bend is affected by the pipe bending procedure. Effects such as initial ovalization, thinning, thickening and plastic hardening from the bending procedure are examined and the mechanical properties of pipe bends containing these effects are investigated.This has been evaluated by creating a detailed Finite Element model of a pipe that is being bent. Then the differences compared to a bent tube in a virgin state, so called Elbow elements and an analytical in-house program have been evaluated. The virgin state refers to a model of a pipe that is bent from the beginning, thus having a homogeneous thickness and not containing any plastic hardening. The Elbow element is a calculationally cheap element, specially developed for accurate calculations of pipe bends in an initially virgin state.The goal with the thesis work is to get a better picture of what happens to a pipe as it is being bent, how this affects the mechanical properties and to evaluate the possibility to develop an easy method for taking these effects into account when using the Elbow element.This report describes the layout of the work and how the detailed FE-model has been constructed.
Minivindkraftverks inverkan på lågspänningsnät
Micro-power wind energy convertors have recently increased in popularity. The reasons for this are among other things the increasing cost of electric energy and enviromental concern.In this thesis the connection of these micro-power wind energy convertors to the utility network is discussed. Electric standards for the connection of small production units is presented. Finally some calculations and measurements of electric quality are also presented. The utility network used in the calculations is part of Halmstad Energi och Miljö network..
A Strategic Decision-Making Model for Supply Chain - A Void to be Filled
Many researchers emphasize the increasing strategic importance of supply chain management, but there is still a lack of concrete guidance for managers faced with strategic decisions in supply chain. Within decision-making theories, the rational decision-making model is the most commonly used. This because of its suitable foundation, enabling a structure to the complex decision process. The rational decision-making model is today not developed to include the aspects of strategic decision-making made in supply chain. The purpose of this research is to adjust a structured rational decision-making model, making it applicable for strategic decision-making in supply chain.
Tätning eller ventilering mot fukt på kalla vindsutrymmen
This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab.The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics.The background of the problem with moisture is that today?s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate.
Dynamisk modellering av VSC-HVDC : En statisk och dynamisk modelldesign o?ver VSC-HVDC fo?r implementering i ARISTO
This thesis treats the subject of a complete steady state and dynamic model of the VSC-HVDC covering both the AC and DC system-side of the converter. The topology of the model is recreated after the scheduled transmission line in the south of Sweden, called SydVa?stla?nken. The topology covers both a simple two terminal connection as well as a multi-terminal one. This model is to be implemented in the power system simulation program ARISTO.
Beräkning av direktljud genom homogena betongväggar : Densitetens och tjocklekens påverkan på reduktionstalet
Today's urban centers become denser, which contributes to higher demands on sound and noise. It is therefore highly relevant to build homes with good sound environment while maintaining living space. This thesis aimed to reduce the current concrete walls and see how the mass law affects the reduction index value and flanking transmissions. Handmade calculations were calculated according to the Swedish standard SS-EN 21354-1, where only air sound was calculated.Calculations were performed on wall elements with different weights and thicknesses, and compared with results from Bastian.In Bastian calculations of flanking transmissions were also made, this was made to see the impact of the flanking transmission when changing the mass per unit area. Mass law's impact was examined by flanking transmission and the result shows that they are not affected as long as the ratio between the thickness and the density remains the same.A questionnaire survey was conducted to determine the actual sound experience; this questionnaire was conducted on three concrete buildings in Växjö.
Yrkesrelevant Gymnasiearbete på El- och Energiprogrammet
The purpose of this development project is to create a model for working with a high school project in Electrical and Energy Program. It should be conducted in a form like companies do according to the goals from The Swedish National Agency for Education. In order to fully perform this we use the concept of Young Entrepreneurship. The model is created according to the new conditions from The National Electrical Safety Board. There is now an exception saying that a student during education is released from the demand of employment that is the normal procedure where you are under supervision from a certified electrician. During the project there has been theoretical and practical examinations in order to clear out the advantages and disadvantages using this model, but also to examine whether it is useful in the future and to what extent it can be used. The result indicates that the model is useful and fulfills the goals from The Swedish National Agency for Education but that the model has its limitations and difficulties.
Stubbskörd : från modell till verklighet
In the near future we need to reduce the greenhouse gas emissions significantly for the benefit of the environment around us. The European Union has de-manded a variety of climate and energy goals to be achieved by year 2020, the ?20-20-20? targets. With these aims, The European Union means that we must reduce our emissions from fossil fuels and instead increase our renewable fuels.
With stump harvest in the forest it?s possible to increase the use of renewable fuels and reduce our emissions from fossil fuels.
Beräkning av energianvändning i svenska småhus
An energy calculation model for Swedish houses that is fast, flexible and user-friendly has been developed within the framework of this thesis. The model also provides a set of actions which may be investigated in the model based on savings and payback period. Energy use in a house depends on the technical conditions, such as building envelope and heating systems, which outdoor climate the house is exposed to and who lives in the house. Energy use for a house can be divided into heating, hot water and household electricity. There are several methods to calculate the energy use of a house. This report summarizes the methods that may be suitable for a fast and user-friendly calculation model.
Marknadens riskpremie ex-ante på Stockholmsbörsen
Resultaten visar på att abnormal earnings model är en mertillförlitlig modell i förhållande till dividend growth model. Dettafrämst då abnormal earnings model grundar sig på mer tillgängliginformation samt att tillväxträntan i dividend growth model harkonstaterats vara orealistiskt hög. Analytikers prognoser tenderaratt vara optimistiska i början av undersökningsperioden 2000-2002. Perioden 2003-2007 präglas mer av pessimistiskavinstprognoser. Marknadens riskpremie fluktuerar mindre underperioden 2005-2007, vilket kan förklaras utav införandet av IFRSår 2005..
Småskalig elproduktion i Arvika
Arvika Fjärrvärme AB, a district heating company from Arvika, today cover 74 % of their total energy production with biofuel wich runs a 16 MW bioler giving process water at saturated liquid state.In recent years Vaporel AB has introduced a new tecnique that gives an external generation of steam after boilers. The concept is built on an adiabatic pressure drop of the saturated liquid in a so called Flashbox which makes a small part of the liquid to evaporate. The generated steam is lead into a turbine where electricity is in a conventional manner.The purpose with this rapport was to do a basic study for the specific system at Arvika where it?s possible to see the potential production of electricity that follows an installation of a flasbox.The final goal was to introduce an economic analysis of a flashox installation at given conditions.To reach our goals we have created a model in Excel where we used the given conditions at Arvika Fjärrvärme to do our calculations. The model has been tested at three different states, of process water returning to potboiler, to be able to decide the optimal operation for the system at present.The studies have resulted in a pressure of the processwater at 14,5 bar (at) and a pressuredrop to 9,5 bar (at) in the flashbox.
Higgsbosonen, standardmodellen och LHC
This report aims to provide an insight into the particle physics of today, and into the research that goes on within the field. The focus is partly on the recent discovery of the Higgs boson, and partly on how software can be used to simulate processes in particle accelerators. Basic concepts of particle physics and the search for the Higgs boson are discussed, and experimental results, including those from the Large Hadron Collider, are compared with simulations made in MadGraph 5. Furthermore, simple new models of particle physics are created in FeynRules, in order to make simulations based on the models. To support the presentations of these aspects, some of the underlying theory is built from the ground up.
Värdeförändring på butiksfastigheter och makroekonomiska variabler - en ekonometrisk studie av samvariation
The purpose of this Bachelor thesis in Economics at Lund University is to try to establish the correlation between the value change of retail real estate buildings in Sweden and macro economic variables. The principal method is the multiple regression model and it is used to estimate the basic model. The basic model is enhanced by estimating some 30 models and the result is two good models. The difference between the basic model and the two better models are small but important. In the lagged basic model, the same variables are used as in the basic model but with different time lags.
Skolsituationen för elever med betyget MVG i matematik : En fallstudie av fyra elever i grundskolans årskurs 9
This thesis has been focused around the Diels Alder reaction with the goal to design an enzyme catalyzed reaction pathway. To achieve this goal computer aided enzyme design was utilized. Common traditional methods of computational chemistry (B3LYP, MP2) do not do well when calculating reaction barriers or even reaction energies for the Diels Alder reaction. New calcu- lation methods were developed and tested. This was the focus of the first part of the thesis, by choosing a small system, extensive and heavy calculations could be done with CBS-QB3.
Den svenska modellen och dess framtid
This study reflects on the swedish model and the models future. The swedish modelmeans that legisilation acts with the collective agreements . The wage issue is notregulated by law instead it is managed by the social partners in the form of collectiveagreements. In 2008, a report was presented by the Commission on a joint regulation ofthe minimum wage for all EU countries. The issue has become increasinglycontroversial and was especially disccused for the election of candidates to theEuropean Parlament last spring.