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404 Uppsatser om Metal cutting - Sida 18 av 27
Nytt spritsrör på TwinRoll typ TRPE : Undersökning av kostnad på spritsrör
This thesis describes possibilities for Metso Paper to lower their costs of spray pipes for their pulp wash press TRPE, with maintained good functionality and quality.Information that can be used by competitors has been censored in this version of the essay.To find solutions, alternative suppliers have been contacted and asked to quote. There has also been a new spray pipe designed. The manufacturing costs of the new design have been calculated.The thesis also contains a concept generation of an alternative product to the spray pipes in installations where a high pressure washer is used.To be able to ask other manufacturers of spray pipes to quote, a demand specification based on the currently used spray pipe was made. This was then sent to two alternative suppliers.An investigation of earlier used spray pipes, and the currently used, shows that the nozzles are a big part of the total costs of the spray pipes. To attempt to reduce the nozzles high cost an concept generation was made to find the best solution for a new design.There was a request that it should be possible to change the internal brushes in the spray pipe without cutting and welding.
Konstruktion av kostnadseffektiv fläkt till härdningsugnar
Scana-Booforge is a Swedish company which specialize in heat treatment of various metal. The treatments take place in quenching ovens, where fans are used to circulate the hot air. The fans used today do not have a satisfactory lifespan. This thesis aims to develop a new design of the fans for the quenching ovens, and the goal is that the new fans will bring cost savings for Scana-Booforge.The design development process started with mapping out the environment in which the fans operate, and with analysis of the existing fan structure and damages, in order to establish the cause of failure and of short durability. The performance of the fan were also established at this stage.
Vad påverkar skogsägarnas naturhänsyn vid föryngringsavverkning i region Mellannorrland? :
The objective of this thesis was to investigate what influence nature conservation measures taken at regeneration felling. Factors analysed were the forest owners´ situation and their characters, and information activities from wood-suppliers and the Regional Forest Board (RFB). The inventory was performed with a posted questionnaire followed up by telephone to forest owners and a posted questionnaire to wood-buyers.
The forest owners were grouped in three strata, depending on the quality results (D- polytax inventory) of the taken forest conservation measures, and for this investigation forest owners were sampled from the population in the tree groups. In total 73 % (41/56) of the sampled forest owners answered the questionnaire
Group A (17 answers): Good judgement
Group B (19 answers): Bad judgement
Group C (5 answers): This group was formed from the forest owners that were informed, by RFB, about nature conservation measures and culture history consideration before the regeneration cutting.
Förutsättningarna för ett parallellt generation IV system vid svensk nybyggnation av kärnkraft.
A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.
Ackumulation av CO2 och CH4 i istäckta boreala sjöar : Hur förändras ackumulationen i sjöar påverkade av avverkning jämfört med referenssjöar?
The aim of this report was to quantify the accumulation of carbon dioxide (CO2) and methane (CH4) in ice-covered lakes in winter (October-March) during three consecutive years, and to assess whether the concentrations of DIC and CH4, as well as the ratio DIC:CH4 differs between years and between lakes affected by clearcutting and untreated reference lakes. Water- and gas samples were collected from four boreal lakes (two affected by clearcutting and two untreated reference lakes) located in Västerbottens inland in spring. The lakes were found to accumulate on average 91, 55, and 84 mgCm-2d-1 during winters 2012-2013, 2013-2014, and 2014-2015, mostly originating from CO2. The concentrations of DIC (autumn and spring) were higher in the affected clear-cut lakes compared to reference lakes for all years, including the reference year (2012-2013) before clear-cutting. No such difference was found for CH4 or the ratio DIC:CH4.
Identifiering av lakbara potentiellt farliga ämnen i gummiasfalt
The main purpose of the project was to identify potential environmentally harmful substances which can be leached from rubber asphalt. A method for analysing asphalt was developed and three rubber asphalt materials were analysed after being cryogrinded. One of the materials was also tested in a road machine made for testing of asphalt paving. The particles created in the machine were analysed in the same manner as the cryogrinded asphalt materials.The asphalt materials were leached by water during 24 hours. The leachates were extracted with dichloromethane, dried with sodium sulphate and concentrated to a small volume.
ACL-rupturer hos fotbollstjejer ? riskfaktorer och prevention
Non-contact anterior cruciate ligament (ACL) injuries is a serius and traumatic injury to the knee that is common in female soccer players and often force the player to quit or lower the level of activity because of lost stability in the knee or from fear to suffer a new injury. Female soccerplayers have a higher risk than their male counterparts to get an ACL rupture and especially adolescent females have a high risk. The most common causes to a non-contact ACL rupture is side-cutting manuvers and landing after jumping. Every other player with an ACL rupture develops osteoarthritis within 10-15 years from the time of injuryResults: The higher risk for females to incur a ACL rupture is due to smaller intercondylar notch, they?re in the follicular or ovulatory phase of their menstrual cycle, increased knee laxity, dominance in the quadriceps muscles, flexion in hip and valgus movement in the knee.
Miljöanpsassad metod för hjultvätt
In order to avoid harmful substances ending up at the municipal sewage treatment plants, it is important to purify the wastewater at the source. One such source is the wheel washers available in many tire garages which are used to wash the wheels on our vehicles when we change between summer and winter tires. It is important to wash the wheels before storage, to extend the tires lifetime. The purpose of this study is to find a green innovative solution for reduction of emissions of heavy metals at the source, so that the sludge from the sewage treatment plants can be used as fertilizer. The target is to find a wheel wash method which leads to compliance with the guidelines for car washers, and that also provides a better washing result than with the existing method.
Entrébänk för Bonum seniorboenden
The following report comprises my bachelor´s thesis in Industrial design, 30 hp. It is executed in collaboration with Bonum senior housing, who has been the client and assignment- maker of this project.The goal was to design a bench for their entrances, which could represent not only the needs of the target group but also Bonum as a trademark. The work is done with great care for both human kind and the environment, with sustainability as beacon.The design process has been followed.Initially, you will find the definition of a bench for entrances, the framework including inclusive as well as sustainable design, a function- and market analysis followed by the inspiration part of the project. Getting to know the target group and their specific needs has been essential for this work.Investigations about what senior house living and senior products are and what the target group thinks and feels, has been done. As a result, two ?personas? has been developed.With the help of a purposely chosen group of people, surveys and ergonomic studies has been executed, as well as prototype-testing.The fact-finding has formed the stable and unavoidable foundation of this project, which later on gets more creative and idea based.
Konststycket
Projektets utgångspunkt är ett nytt konstmuseum i Uppsala, i området bakom Uppsala centralstation, som nyligen genomgått ett ansiktslyft.Museets långsmala karaktär har hämtats från det intilliggande godsmagasinet och från tomtens form. Genom byggnaden har ett diagonalt stråk öppnats, för att ge möjlighet åt fotgängare att passera genom byggnaden och för att skapa liv och rörelse på platsen.Genom fönstren i passagen kan förbipasserande få en skymt av vad som händer inuti muséet. I passagen ligger museets entré, den pedagogiska verksamheten och ett kafé för allmänheten.Museets fasad är inspirerad av den arabiska mashrabiyan. Byggnaden har fönster längs hela fasaden, som i sin tur är täckta av skärmar tillverkade av sträckmetall. Ljuset tillåts komma in i byggnaden samtidigt som sträckmetallen täcker fasaden och bevarar något av museets hemligheter för förbipasserande.Museets inre väggar består av massiva betongskivor, placerade i ett rutnät som fått sin riktning av passagen genom huset.
Samband mellan tjockleken hos PVD-skikt och förslitningsbeteendet vid svarvning
This project has as main goal to study the influence of the coating thickness, deposited by arc-PVD- technology, on the wear resistance of coated cemented carbide inserts in three different turning operations. An additional effort has also been made to develop a new test method for evaluating flank wear resistance. Three different coating types (Coating A, Coating B and Coating C) have been studied in three distinctive thicknesses (2, 4 and 6 µm) for each type. For two of the coating types (Coating A and B) special studies has been done with the thickest coating, creating two additional coating versions of the thickest coating, by changing various deposition parameters, with the aim to enhance the cohesive properties of the coating and lower the residual stresses at the cutting edge. The results show increased crater wear resistance with increased coating thickness for all coating types, but the amount of increase changes with coating type (Coating A>B>C).
En studie om förutsättningar för ledarskap i kunskapsintensiva verksamheter
Title: A study about conditions for leadership in knowledge-intensive firms.Authors: Cecilia Ekström and Niklas SandbergKeywords: Leadership, knowledge-intensive firm, hierarchies, followers.Background: Leadership is becoming one of our greatest social myths and is considered a total solution for many problems that occur in an organization. The view of leadership is usually from a top-down perspective, which contributes to an often underestimated view of the follower. Just as it is important to understand the leader's view of leadership, it is important to understand how employees view the structure from which the leader derives its legitimacy. The existing conditions in knowledge-intensive firms, such as autonomy, place special demands on the formal leadership.Purpose: The purpose of this study takes an employee perspective, to understand what the conditions are for formal leadership in knowledge-intensive firms.Method: A qualitative research method was used and empirical material was collected through interviews with employees in knowledge-intensive firms. The empirical material was analyzed by the respondents? mental images which were set against the theoretical framework of the thesis.Conclusions: The conditions for formal leadership in knowledge-intensive firms make it advantageous to have a leader with a withdrawn role.
Säsongsvis avverkning : det operativa traktvalets påverkan på den säsongsmässiga uthålligheten i ett bolagsdistrikts traktbank
Due to soft grounds in combination with seasonal variation in soil humidity, there is a lack of stands that are possible to cut during spring and autumn in some geographical regions. For Holmen Skog this sometimes means that a large proportion of the contracted private forest is cut during the winter when the ground is frozen. One consequence of this is that the proportion of winter stands in the stand bank of own forest increases while spring and autumn stands becomes a scarcity. This in combination with milder winters, especially when there is a long period of reduced bearing capacity in spring or autumn, means that the situation rapidly can become critical.
The overall goal with this study was to generate basic data for decision support in the work to achieve a sustainable distribution between own forest and contracted private forest in the stand bank.
The study took place at Holmen Skog, district of Umeå, during autumn 2007 and was based on interviews and an analysis of harvest planning and delivery data.
The study showed that there is a problem with how the cutting is distributed between own and contracted private forest during the year and that it foremost is the proportion of winter thinning of own forest that has increased in the stand bank.
Faktorer som påverkar sjuksköterskans användande av omvårdnadsplaner : en litteraturstudie
The purpose is to illustrate the phenomenon of self-harm from a social psychological and sociological perspective. The purpose is furthermore to examine the role social relationships play in the individuals´ self- imagine and what role does identification play for anyone who harm themselves? We want to examine in what way social relationships are important and how they function for individuals who harm themselves, both once they have started to harm themselves, and if the relationships in any part caused the cutting to begin with.Questions:How do individuals shape their identity based on self- harm? Which self-image do individuals have who self-harm? Is there anything in the person's previous social relationships that have caused them to begin to hurt themselves?Method:In this paper we have analyzed five autobiographies. We have used open coding from grounded theory as analytical method and subject positions based on discourse analysis.Theory:We have used the Cooley concepts looking glass self, Foucault's theory of power, Giddens' concept of ontological security and existential anxiety.Results and Analysis:We found six different categories that we thought were central. These were negative self-image, guilt, lack of family support, negative experiences of others' views, the protective identity as self- harmer and insecure social relationships in school.Conclusion:The self-harming is a very complex behavior.
Analys av förvridning vid hålning av rör : Analysis of metal torsion in rotary piercing
Hålningsprocessen är det inledande bearbetningssteget vid varmvalsning av sömlösa rör. Det är en tvärvalsningsprocess i vilken ett cylindriskt ämne valsas mellan två dubbelkoniska val¬sar över en plugg. Valsarna är snedställda med en viss mat¬ningsvinkel, vilken ger upphov till en axiell drivkraft genom ver¬ket. Hela denna pro¬cess är roterande. Detta i kombination med bl.a.