AbstractThis Master?s thesis analyses the dynamics of the medieval counterweight lever engine, ortrebuchet, a type of mechanical artillery. The purpose is to study the differences between different types of these machines, and see if computer simulations can be used to validate preserved advice on construction. Simulations include machines with a fixed counterweight, a hinged counterweight and a combination of both counterweights.Due to the almost complete lack of archaeological finds and insufficient historical source material there are still, after more than a century of research, many unanswered questions concerning the design and performance of these machines.The present study is based on an analysis by Jahsman (2004). A more detailed mathematical model employing Coulomb-friction is used.

This report was performed in order to evaluate a new technological measure and focuses generally on a heat pump system to a HWC-washing machine. The client is Asko Appliances AB, a company well known for its environmentally friendly products. The goal of this study was to improve the energy efficiency of a washing machine by combining a heat pump device to the heater of the wash water, in order to reduce the energy consumed for heating the water. Besides reducing the energy consumption in heating the water, the washing machine was required to meet low noise and short operating time specifications. For that purpose, nine trials in three test series have been carried out.

This master thesis was conducted at Motala Wire Works Ltd (MWW) in Motala during the autumn and winter of 2007-2008. The thesis named ?Future layout of Motala Wire Works? focuses on making a better planed layout for the factory, which also take in to consideration future changes.Motala Wire Work produces wire mesh products of varying sorts for the white goods industry. The factory was started by Electrolux during the 1950?s.

This examination work brings up opportunities to invest in a construction for heating with grain or pellets on farm level. As example we have chosen Fröberga Gård which is a farm located in Östergötland outside of Söderköping. The farm`s residential buildings is to day heated with oil and electricity. The result of our investigation shows that heating with grain is the best alternative, partly because of economical issues but also because you can grow the grain on your own farm and by that you can get better economy in your seed cultivation. To grow 16 tonne of grain as is needed demand gives a insignificant increase of work. Further an advantage is that no investment in machines is needed because all the machines witch is needed already is in use on the farm. In a situation where a new investment is needed as in the case we studied, is it often profitable to invest in a integrated furnace. Because all the components are well adapted to each other, and because that gives a high efficiency. If you already own a well working furnace is it often most profitable to connect a burner to it. It is important to know that heating with grain need more work than heating with pellets, because the high contents of ash in grain. Even if you choose pellets instead of grain the calculation shows good results. Because peat is an excellent but fairly untested raw material for pelletsproduction we have chosen to watch little more on its quality and conductions. We discovered that peat has a high heating value which makes it possible to raise the heat value in pellets through mix up peat and wood. Or you can make pellets with only peat and get a pellet with high heating value. Even the calculation with peatheating shows good results..

The aim of this report is to analyse the use of the capacity at the CNC (computer numerical control) cutters and show how the level of set up time for these cutters at Stålöv AB. This assignment is concrete whereas there are no subjective questions to this matter and there are only cold figures presented.Production economy is getting more important as the competition hardens and there are several different ways to increase productivity and efficiency in a company. In order to increase productivity and efficiency work studies are used to, through an analysis, find developments in methods that result in improved work methods and to establish the time that are used. Increased production of different parts and customer driven production in combination with increased demands on rationalisation of capital have led to an enlarged interest for shorter set up times in the production.To point out the use of capacity and the set up time of the cutters at Stålöv AB we used frequency studies. Frequency studies are work measure methods based on random observations on predetermined events to calculate the relative occurrence of these events.

Kvalitetsbristkostnader handlar om att veta hur mycket avsaknaden av kvalitet kostar organisation samt att spåra dess orsaker och effekter. Genom att mäta kvalitetsbristkostnader kan förbättringsmöjligheter identifieras och resultatet av förbättringsåtgärder mätas. Mätning av kvalitetsbristkostnader bidrar även till att kvalitetsfrågor får en mer framskjuten roll i företaget. Denna studie har genomförts på ABB Machines och inom ABB AB finns idag en förståelse för att bristande kvalitet kostar pengar. Arbetet med att identifiera kvalitetsbristkostnader har därför fått hög prioritet.

In Stockholm, Johanneshov the Slaughterhouse area (Slakthusområdet) can be found. A number of companies have gathered there providing the Stockholmers with meat products. This area has a great need for cooling to supply large cold storages. To facilitate this, a central cooling system has been built, supplying the area with effective and safe cooling.The aim of this master thesis study is to give hints to energy efficient and reliable changes that can be put in place at a low marginal cost depending on the future activities in the area. The suggested changes will be presented to the company Bravida (managing the system), which also desires a deeper understanding of the energy flows through the central cooling system.Firstly visiting the site with proper guidance, we have then tried to understand the function of the system including which machines and media that are used.

The vision of this thesis was to create a concept that can be used as a base for amachine construction. The purpose of this project was to use different methods todevelop a concept that on the best way meets the sat up requirements. This projecthas been divided into three stages/parts; principle, primary and the final solutionstage.This thesis has been conducted in collaboration with Västkustägg AB. It is aconstruction project designed to construct a machine that will automatically putlabels on the egg packages. Västkust AB wanted to automate this process.

Induction motors, often referred to as the workhorse of the industry, play an important role in production today. Therefore, it's important to diagnose any faulty induction motor prior to failure to avoid costly and time consuming production stops.This thesis compares methods for diagnosing induction motors in operation, MCSA, Park's vector approach and the standard method used by Swedish industries today. By simulating broken rotor bars and short-circuit in one of the windings, each method is tested and the results are compared using matlab.The results need further verification due to uncertainties of the condition of the test motor, even though the experiment gives a hint of the different advantages of each method. A combination of the methods should be able to tell if the motor needs further examination..

The most predominant method for forest harvesting in Sweden is the cut-to-length method based on two-machines, a harvester that fells trees and cut them in a predefined length, and a forwarder which transports logs to a landing area for further transport to a processing facility. New machine solutions have to be much gentler to the ground than today?s machines. To be able to develop a forestry machine that preserves the terrain requires a proper understanding of the interaction between tire and soil.The goal of the project is to contribute to the existing knowledge of forest machine tire-soil interaction and to develop a tire-soil model that enables dynamic simulations of forest machines operating in rough terrain. The modeling has especially been focused on the interaction between tires and soft ground.A comparison of theoretical data of different WES-based terrain interaction models and a comparison test data from a full scale field test is presented.

Research has shown fear of childbirth to be as common among men as women, but the phenomenon has not been as studied among men. Some men have trouble talking about their fear and therefore don?t get the support that they need. Where to go to get help is not so obvious for these men. The name mostly used for this clinic is Aurora.

Åmotfors Bruk AB (ÅBAB) has today an inefficient production of steam for the manufacturing of paper. Unpredictable energy prices and modernisation of the current equipment has been the underlying factors to invest in a thermal power plant, mainly driven by garbage. This facility will not only use the steam for paper production, it will also generate electricity through a steam turbine. Today, when a fault on the supplying line occurs which leads to disconnection of the external grid, all the support of electricity to Åmotfors Bruk (ÅB) will disappear. This will lead to major interruptions in the paper production, which will cause severe economical losses.

Hemp is an old agricultural plant and has been used for hundreds of years for making textiles, ropes and other fibre products. In the middle of the last century the Swedish government prohibited all growing of hemp. Natural fibres were replaced by syntetic fibres instead. Today there is a newly awakened interest for using natural fibres from renewable materials. Growing of industrial hemp for fiber is allowed in Sweden again. I want in my Paper give Swedish growers an insight of which harvesting methods that have been tried in Sweden and how they worked.

Forest streams and the associated riparian zones are sensitive to disturbances and changes that occur within these riparian areas. Particularly sensitive are small streams of low order, which will have large impacts down-stream. The disturbances that occur in the riparian zones are reflected quickly in the stream. Driving with forestry machines in the riparian zone will have detrimental effects to the soil and water. Driving the machines will lead to changes in the mineral soil composition, resulting in the reduction of porosity, less infiltration, compaction, and an increased bulk density.

The scarcity of qualified forest machine operators as well as the increased competition for competent machine operators among others from the mining industry in Norrland, were the reasons to investigate what attracts and what deters active and potential forest machine operators to the occupation. An interview study was conducted among four groups with four persons in each group. The groups were students in year 1 and 3 respectively at a forestry school at upper secondary school level as well as employees of a forest company and employees of contractors. The majority of all respondents were of the opinion that their interests in machines had been important for the choice of occupation. But for the active machine operators both the interest in the forest and their interest for machines have had importance for choosing this occupation.