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1998 Uppsatser om Steel construction - Sida 41 av 134

Modell för att utvärdera spänningar vid reducervalsning

Ovako Steel AB i Hofors tillverkar varmvalsade rör. Ett av de sista stegen i tillverkningsprocessen är en konventionell valsning i ett antal valspar kallad reducervalsning. De valsade rören uppvisar ibland en ojämn väggtjocklek längs rörlängden på grund av att det uppstår drag- och tryckspänningar i rören mellan valsparen. Syftet med examensarbetet är att öka kunskapen om dessa spänningars inverkan på det färdiga röret samt ge förslag på hur processen kan förbättras. I examensarbetet har undersökts vilka parametrar som påverkar spänningarna i valsningsprocessen.

Solenergi på Kvarnholmen

In recent years it has become more and more evident that man has contributed to much of the climate changes that have taken place during the last century. A major challenge today is to reduce emissions and energy usage at the same time as the global population is growing. To contribute to a better environment, Stockholms Stad has set at target of becoming fossil fuel free by the year of 2050. The construction of new districts is done with this goal in mind; energy efficiency and renewable energy sources are examples of methods to achieve this.Solar energy is considered to be a sustainable energy source and the most common techniques to harvest solar energy in Sweden are solar cells and solar collectors which produce electricity and heat respectively. This report aims to investigate whether an investment in any of these systems would prove to be economically beneficial at Kvarnholmen, a district under construction in eastern Nacka, Stockholm.Since the finished blueprints only cover a small portion of Kvarnholmen, the report examines the possibilities for a house where construction has already begun, Nya Kvarnen.

Moderna trä- och betongstommar i flerbostadshus : En teknisk jämförelse av ett fyravåningshus med två stomalternativ.

Målet med detta arbete var att belysa skillnaderna mellan ett fyravåningshus med trä- respektive halvprefabricerad betongstomme ur ett tekniskt perspektiv för att utröna vilket stomalternativ som är att föredra.Faktorer som belystes var:Tjocklekar på bärverksdelarLängsta möjliga spännvidderInstallationsmonteringElementmonteringGrundstorlekLjudisolerande förmågaRisk för fuktskadorBranddimensioneringProjekteringskomplexitetBygghandlingar från ett befintligt flerbostadshus med trästomme erhölls och analyserades, och ett hus med likvärdig stomme av betong projekterades.Bärverket med halvprefabricerad betong dimensionerades efter rådande Eurokoder och detaljer utformades enligt gällande lagar och regler samt erkänd branschstandard.Ur de tekniska perspektiv som avhandlats i denna rapport väger fördelarna med betong något tyngre än träalternativets fördelar trots att egenskaperna i vissa hänseenden är mycket lika.Betongalternativet ger stora fördelar vad gäller brand och ljud och är samtidigt enklare att projektera, medan trä har sina fördelar i montering och grundläggning. Att välja en stomme av trä till ett flerbostadshus verkar också ha fördelar i de icke avhandlade aspekterna, t.ex. miljö och arbetsmiljö.För att uppfylla ljud-, brand- och fuktkrav i ett trähus krävs det avancerade byggsystem som innebär stor komplexitet i projekteringen vilket kräver ett nära samarbete mellan träprojektör och fabrikör. .

Ombyggnad av flerbostadshus : Hur påverkas hyresgästerna av  en ombyggnad

During the years 1950-75 was the construction of building apartments in high speed. A rapidly growing reconstruction requirement is the consequence of the rapid construction speed in these years. The technical lifetime of the different parts of the buildings is about to end and the needs for reconstruction is huge. One of Sweden's national environmental objectives is to reduce the urge of energy in buildings. This calls for radical measures to implement energy efficiency of existing assistance particularly in the assistance that is now facing reconstruction.

Planering och val av metod i byggprojekt

This report describes the construction process and the aspects that should be taken into consideration. It includes models of decision and how these can be used in practice. Planning of a building project is very important for a successful execution. This will be the foundation of problems that will occur during the production. In the planning process people with different positions, search for the best suitable building methods.

Ekot från djupaste Afrika : En kritisk diskursanalys av nyhetsprogrammet Ekots gestaltning av konflikten i Goma, Demokratiska Republiken Kongo.

This is a critical discourse analysis of the conformation of the conflict in Goma, Democratic Republic of the Congo, as constructed by Ekot, a news-show on Radio Sweden. The ambition of this bachelor thesis is to examine the production of a Congolese conflict for a Swedish audience and to find out how the construction differences with and without a reporter in the field. To obtain this purpose the narrative is studied as well as the use of voices that define the conflict. The construction of proximity between Swedish audience and the Congolese event and the meaning of sound to stabilize the formation of discourse within foreign news is examined as well. To conform and explain foreign news it must be put in relation to a starting point.

Jämförelse av solhybrider

Research in solar energy is taking big steps in both solar heating and solar electricity. It´s not only the technologies alone, but also the combination of both solar electricity and solar heating which is what is called a solar hybrid. The idea of a solar hybrid is that a solar cells efficiency decrease with increased temperature and can with help from a solar collector be cooled and the heat can be utilized. This thesis report compares heat production and electricity production with respect of, in first hand, a solar hybrids geometry in the cooler. The theory chapter describes solar heating and how different solar cell technologies work and their environmental impact at the production and how compatible these technologies are for the solar hybrid.

10-åring spårlöst borta : En studie om hur försvunna barn konstrueras i svensk press

The purpose of our study was to examine how missing children are portrayed in media. We wanted to see if there are any recurring story patterns and characters in the texts. We also wanted to examine how the relationship between children and adults are framed and which comprehensive view of children is mediated in journalistic texts.Our questions were: how do Swedish newspapers write about missing children? Which narrative pattern are there in the texts? How are children and adults represented in the texts? What relationship between children and adults are made visible in the texts? What a comprehensive approach to children is constructed in the texts?For this study, we used the media discourse, theories of representation, stereotypes and characters. And theories of narrative, dramatic turns and opposites.We chose to make three case studies in which children suddenly disappeared, the case of Bobby Äikiä, the case of Engla Höglund and the case of Sebastian Hedman.

Konstruktion av steghållare till brandbilar

High demands are set on all equipment used in emergency service work, where small margins can be the distinguishing factor between life and death during a rescue operation. It is important that tools such as ladders quickly and easily can be dismounted from a vehicle and still satisfy the regulatory requirements for securing loads during transport. The existing solution for getting ladders down from the roof of a fire engine requires a large manual effort from the user in an ergonomically unsound posture.In this degree project a new ladder holder is developed with focus on the user to solve the ergonomic problems and at the same time create a more compact design that can be adapted to several different types of ladders. After an initial pre-study with user-interviews and measurement of forces and distances a set of requirements was formulated that came to govern the project's direction. Creative methods were used to generate concepts that improved the function and through design solutions, calculations and testing in CAD a base for manufacturing of a new product was created.The result is a completely new type of ladder holder that minimizes the user's manual effort and simplifies the securing of ladders in the holder.

Prefabricerade Passivhus

European Union has made a new decision that all new built houses by 2020 shallbe near-zero energy houses. Boverket?s definition of near-zero energy housesintends buildings with good energy performance in which a proportion of theamount of energy that must be added to the building is made of renewable energy.Passive House is a set of requirements from FEBY designed to build energyefficient buildings. This is achieved by reducing loss of heat through the buildingenvelope and to take advantage of the passive heat from solar radiation,installation and heat sources like people living in the house.This project has been made with help of Anebyhus and one of their model houseshave been examined from the report?s issues, including Anebyhus?s energyperformance, requirements for the manufacturing and assembly, how theenvelope must be improved to fulfill the requirements for the Passive House andwhat energy calculation programs are available on the market.The report aims to provide solutions for energy efficient houses that are adaptedfor production of house building.Two visits to Anebyhus has been done to study their manufacture and assemblyof building elements.

Mek Stans 07

Mek Stans 07 is a machine developed for Tetra Pak in Lund as a 10p candidate theses project at Halmstad University. The commission behind the project involved development of a machine that punches holes in packages for the inspection division at Tetra Pak. The task for the machine was to facilitate the process of making openings for testing in the company?s other equipment. Researches on different methods of cutting, types of automatization and possible designs were made. To implement the project a design and construction from the base where chosen.

En kartl?ggning av inv?ndiga f?nsterluckors utbredning och konstruktion

Interior window shutters can be found in historical buildings, but they are an uncommon occurrence in modern buildings. In modern contemporary construction, large glass panels are often the ideal because of increased light inflow and for architectural purposes. However, this can generate several negative effects, such as increased energy loss, lack of privacy and high sunlight penetration. Problems that window shutters could have accommodated historically. This thesis identifies a lack of knowledge about interior window shutters in the Swedish building stock.

Dimensionering av betongkonstruktioner : En jämförande studie av BBK 04 och Eurokod 2 vid dimensionering av balkar och pelare

Today, we use BKR and BBK 04 when designing concrete structures inSweden, which will, in the near future, be replaced by Eurocode 2. When you are designing buildings, you will use Eurocode 2 Part 1-1 and with this new standard, some new rules and general rules will be necessary to adopt. To examine how BKR and BBK 04 tells apart from Eurocode 2 when designing concrete structures, one beam and one column with often common dimensions, is studied. The beam is designed with consideration of (considerate to) durability at bending moments, shear forces and control of cracking. The column is designed with consideration of durability at eccentric axial load and bending moments in cross section on account of (due to) geometric imperfections. BBK 04 has gone one step closer to Eurocode 2 than earlier editions and the things that are different, when calculating reinforcement, is how they use the partial factors.

Ämnestransport med grundvatten i hydrogeologiska typmiljöer

Certain types of waste, e.g. bottom ash originating from municipal solid waste incineration (MSWI bottom ash) can be used as road construction materials. A potential problem is the possibility of substances leaching out of the road and spreading in the surrounding groundwater.The aim of this master?s thesis is to conclude whether hydrogeological type settings can be employed to, based on local conditions, provide an estimate of the probable spreading of these substances in the surrounding groundwater, and whether certain types of soils can be identified as being less suitable for the localization of a MSWI bottom ash road. A hydrogeological type setting is defined as a mappable unit with similar hydrogeological properties.

Framtagning av ett dimensioneringsverktyg för balkonginfästningar enligt Eurocode och ETAG.

The purpose of this paper is to standardize and simplify the design work on a few specific types of storage brackets for balconies. The company Balco AB had the wish to simplify the design work in the preparation of attachments to their balcony structures. This would be done by a calculation matrix that could be produced which then in turn could be used for each new project by the company. The design work behind the development of these fittings at each new project is costly both in terms of time devoted by each calculation but also the cost of the time. The purpose of this report is that in a systematic manner, a calculation matrix can be created that then the company instead may follow from each new project.In carrying out the project used HILTI calculation program, which was provided by the company HILTI.

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