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345 Uppsatser om Laser Cutting - Sida 13 av 23

Reglerbara skovlar på pumphjul

The thesis investigates if it is possible to replace several pumpimpellers with one controllable pumpimpeller, with a economical and a manufacturing analisys aspect. The studied pumpimpeller is mounted on a midrange wastewaterpump, N3127MT.In the thesis a contemplated manufacturing process is evaluated for a concept that are supposed to act as a controllable pumpimpeller. The pumpimpeller are studied in a manufacturing and flow matter and are presented in the thesis.The manufacturing cost is also estimated, and this has been compared to the storage cost and other costs that the existing pumpimpeller generates.The thesis also shows that the concept has minor losses in cutting quality aswell as the effiency comparing to the existing pumpimpeller.The concept also raises the manufacturing cost and this increasing cost makes the presented concept to expensive to carry through.An investigation of the costs that the existing pumpimpeller produces has also been done, and this shows that there is not that much expenses to earn regarding to for example the storage cost. The storage cost includes information from Flygt?s central storagecenter in Lindas, Sweden and Metz, France, and also an inventory about the pumpimpellers located at Flygt?s different distributors worldwide.The thesis shows that a controllable pumpimpeller will generally increase the cost for the pumpimpeller and the performance of the pumpimpeller will decrease..

Om stenar kunde tala : arkeologiska rön och bebyggelsehistorisk kontext av kvarnstensbrottet Östra Utsjö i Malung

This paper deals with village history around millstone quarry Eastern Utsjö in Malung, Sweden, in the hope of finding deposits that could date the quarry, in that the quarry in the current situation is dated only by the millstone fragments outside the resort. My purpose was to conduct a discussion on the quarry alone can be dated by deposits outside the resort. I have used FMIS RAÄ:s fornsök and a lot of literature to identify village history. The results showed that it is not possible to date the millstone quarry from village history, but through deposits outside the resort of Malung, which have been found around Mälardalen, Sweden through archaeological excavations, and derived from the millstone quarry Eastern Utsjö, can put an age on the quarry..

Att restaurera forna tiders beståndsstruktur : ett exempel från Jämtgaveln

In Sweden today so-called "prescribed nature conservation burning" is performed due to the change in silvicultural law, certification and an increased knowledge regarding the field of fire in the forest landscape. The aim is to re-create structures and qualities made by the fire regimes of the past, though on a much smaller geographical scale. The structures and qualities to be re-created are for example broad leaf stands, trees with large diameter, heterogeneous stands regarding variables such as age and diameter. If we increase our knowledge of the constitution of forests characterized by fire, then we will be able to set goals for what achievements to reach both on landscape scale and stand scale. The aim of this paper is to try to describe how a stand from the past was composed regarding mainly the spatial arrangement and compare it with the stand of today in the same place. This to be done by using relict material, that is stumps and dead standing trees.

En studie av metodbyte vid sintring av hårdmetaller till mikrovågsintring samt dess ekonomiska fördelar : Självständigt arbete i teknisk fysik med materialvetenskap & Självständigt arbete i kemiteknik

The aim with this study was to investigate the effects a change of manufacturing process would have on the mechanical properties of drill bits made of a WC/Co composite used for stone cutting. The method used today is sintering, where the material is heated in a conventional sintering oven. The other method was microwave sintering, where the material is heated by radiation in the microwave region. Also an investigation of the manufacturing cost were made.The main difference between the two heating methods is that the conventional way is a rather slow process and the microwave method is very fast. The material is also heated homogeniously in the method with mirowaves, aposed to the case with the conventional sintering where the material is heated from the outside in.This makes the material harder and more wear resistent.

Dimensionering av ventilhus med avseende på skärkrafter

The company Somas, Säffle, has assigned Fredrik Kjellin the project of finding out how ?KVTF DN250?, one of their own valves, reacts on cutting forces under production. They wish to know if and then how much it?s possible to minimize the wall thickness of the valve with neither plastic nor to big elastic deformations caused by processing.The most critical processes have been identified as rough lathing. The study has shown that the marginal for a wall thickness of two millimeters, to fall short of the yield stress in the most critical process, is good.

St?ndsg?rdens ?vergivna tr?dg?rd: en studie av Kullen i Hova

The higher status homestead called Kullen is located on top of a small hill just outside of Hova in V?stra G?taland. The house stands on a plateau surrounded by a stonewall. Aerial photos from the 1960?s shows what looks like a big parklike garden behind the house, with a gravel walk cutting through on the length of the garden up to the house.

Undersökning av titanföreningar för tillverkning av standarder vid användning av röntgenfluorescens

SECO Tools manufactures tool inserts for all types of metal cutting machining. (Ti,W)C is a common raw material used in the production. At arrival, the material (Ti,W)C is always analyzed. Titanium has previously been analysed with x-ray fluorescence spectrometry, but as the calibration has previously been performed with two different types of titanium (rutile and metallic titanium), the results has differed. Because of that, this thesis project has been devoted to analyze titanium, to find the best titanium compound for producing standards.The work has been performed using literature studies and many experiments in the laboratories at SECO Tools inFagersta,Sweden.

Anlockning och gnag av snytbaggar (Hylobius sp.) : effekt av plantstorlek och behandling med metyljasmonat

Two field experiments were conducted in central Sweden in order to: 1) Determine a relationship between the number of approaching pine weevils (Hylobius sp.) and the number of attacks by pine weevils, in relation to the size of seedlings of Scots pine (Pinus sylvestris). 2) Determine if application of methyljasmonate (MJ) on seedlings of Scots pine will result in higher resistance towards attacks by pine weevils and/or have any effect on the number of approaching pine weevils. The field experiments were designed with two separate parts in close vicinity on the same clear cuttings: a) pitfall traps placed in patches of scarified soil that caught approaching pine weevils at 2.5 cm from the bait, which consisted of different sized seedlings of Scots pine some of which were subjected to application of MJ and b) the same type of seedlings planted out in patches of scarified soil. The first field experiment was conducted on a 1-year old clear cutting outside Uppsala in east central Sweden and the trapping part of the experiment consisted of 8 blocks with 6 treatments: 1) control, 2) small over-wintered seedling, 3) medium sized seedling, 4) medium sized seedling treated with 0.5 ml 100 mmol MJ 4 days prior to start of experiment, 5) large seedling, 6) vial with 9.5 ml of ?-pinene. The trapping experiment lasted for 6 weeks in the early summer.

Förhållandet mellan hudblodflöde och fysisk aktivitet.

SAMMAMFATTNINGBakgrund: Reaktiv hyperemi definieras som ett övergående ökat blodflöde över det normala efter en tids ischemi. Det kan registreras med laserdopplerteknik. Att registrera reaktiv hyperemi är ett sätt att värdera mikrocirkulationen. Det finns många flödesvariabler att studera varav tid till maxflöde efter ocklusion är en. Det har gjorts studier som undersöker om det finns ett samband mellan reaktiv hyperemi och fysisk aktivitet/syreupptagningsförmåga.

Att identifiera signaler för obestånd i tid

To be able to protect themselves from credit risk, the banks must constantly check the performance of  the companies they have lent money to. There are many mathematical models for predicting financial distress. These models use accounting-based ratios, which often are historical and not representative for the present situation. This study describes how the banks do in practice to find signals of insolvency in time and the variables they are observing for doing that.In addition to financial reports which the company sends in to the bank at least once a year, also the relationship between them and information from different information  agencies are of great importance to track  signals of insolvency. Poor profitability is the primary cause of insolvency.

Att arbeta med pedagogisk dokumentation för att överbrygga klyftan mellan teori och praktik : Ett undervisningsförsök för att skapa större förståelse i frisörutbildningen

The aim of this project was to change the way cutting techniques are being taught. I wished to try a method which I believed to enhance my students´ participation and understanding of their education. My purpose was to reduce the gap between theory and practice. After conducting a learning style test I found that most of them considered the best way for them to learn was by combining practice with dialogue and reflection of the tasks being done. That is why we tried to start working with the practical elements rather than traditionally starting with the theoretical aspects, while carefully intertwining terms and language of the trade into the education.

Evighetsträd

FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation. This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock.

Metod för urval av bäriga bestånd längs med bäriga vägar i Sveaskogs planeringsområde Råneå och Överkalix :

With increased need for flexibility in timber deliveries, forest roads become an important factor. The disintegration of roads during the spring season can be avoided if it is possible to rule cutting areas to stands with good carrying capacity along roads with good carrying capacity. The goal with this work was to create a method to find the stands with high carrying capacity located near roads with high carrying capacity, and select them into a collection file. The method was based on Esri ArcGIS 9 and the tables that follow within that program. The method resulted in four different themes: 1. Collections with GYL 100 that cross the bufferzon for 0, 1, 2 and 3 class roads. Result 36 collections. 2. Collections with GYL 100 and 200 that cross the bufferzon for 0, 1, 2 and 3 class roads.

Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet

Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).

Utvärdering av labpilot - flödesbatteri : Experimentell studie

Results have shown that flow batteries may be a solution in the future as an effective and environmental friendly method to an energy storage system (ESS). The technology is reliable and has a high efficiency that comes with low energy losses and a long lifetime. The range of possible fields is suitable for cutting energy peaks in the power grid, by always have a ready and available energy storage that balances the production. By comparing the advantages of flow batteries with conventional batteries it is mainly the fact that they can conserve energy for a long time without being self-discharged thanks to that the storage capacity is in principle endless and limited by the size of the electrolytes tanks that makes them a great energy storage system. The batteries won?t take any damage or decrease in performance when charging or discharging it or if you exhausts it to 100 % and leave it discharged for a long time.

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