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.

In cooperate with Asko Cylinda we have developed a new heat system too short the processtime and reduce the energy consume in a dishwasher and still have it too be a class AAA.The environment and quality is important for the company too still be the number one onthe market, If they want too keep that position the product developed of new innovations willbe very important. The systems we have developed are more effective and reduce energy uptoo 25 %. The process time is reduced too less than two hours, from the today two andhalf-hour. The solutions are too heat up the rinse water and the dishwater at the same time,with a new heating system and it make are solutions unique and effective. Its good for thedish and the environment.

This is a heuristic evaluation of Umeå university library?s Online Public Access Catalog (OPAC). It makes use of four of Nielsen?s ten heuristics, flexibility and efficiency to use, match between the system and real world, visibility of system status, and aesthetic and minimalist design. The evaluation was done by having 3 evaluators inspect the interface individually, as per Nielsen?s (1990) recommendation of 3-5 evaluators.

Fuel pellets are a refined bio fuel mostly consisting of residues from sawmills and wood industry. At Rindi Västerdala AB's combined bio energy plant in Vansbro fuel pellets are produced, while the waste heat from the process is used for district heating. The pellets are produced from sawdust, wood shavings and dry wood chips that is dried, milled and pressed into small cylindrical rods. The advantage of refining the wood material in this manner is that the energy value is greater per unit volume and unit weight, thereby the cost of transportation per energy unit is reduced. Also, less storage space is needed.Pellet manufacturing is a complex process since many parameters affects the final results.

Environment friendly transports are one of the main topics in the industry and society today.Shell organizes an annual university competition called Shell Eco Marathon. The goal is to buildthe car that consumes the least fuel during a race. KTH participated for the first time in 2006.The engine for this competition, DoubleTwo, has been developed within the school. Theprinciple is a two stroke counter piston HCCI engine with variable compression ratio. HCCIstands for homogenous charge compression ignition.

This thesis is the result of the investigation and solution of a mechanicalproblem regarding flywheel malfunctions. A flywheel is, in short, a devicethat relies on a rotating object?s moment of inertia to store energy overshort time spans. This project is part of the development of a fourthflywheel prototype at the division for electricity at Uppsala university,which uses magnetic levitation to keep a hollow cylinder rotating at veryhigh speeds inside a vacuum chamber. Should the magnets fail however, orsome other error occur that leads to an uncontrolled state of rotation, thecylinder needs to be stabilized mechanically by a device usually referredto as ?back-up bearing?.

Emission of nitrogen oxides as well as carbon monoxides is an inevitable result of combustion. A Swedish law "Law of environmental fee for emissions of nitrogen oxides as a result of energy production" (lagen om miljöavgift på utsläpp av kväveoxider vid energiproduktion (SFS 1990:613)) controls the emission of NOx from energy production by a system of fees. The system has resulted in a strong approach toward less emissions of NOx among the energy production plants. High emission levels, today exceeding 52 mg/MJsupplied fuel, leads to costs for energy production companies. This paper examines possibilities to reduce the emissions of NOx by optimization of the SNCR-technique in a biofuel fired heat and power plant.

AbstractWe are interested in group meetings of the self-help group Alcoholic Anonymous and the emotional energy created therein. We examine which impact self-help group AA has on its group participants regarding: group meetings, dealing with alcoholism and identity. Group membership has great value for individuals; it provides social identity and possibility to self-value. Previous research shows that group members of self-help groups who have been sober for a period of time experience higher self-esteem and less anxiety compared to non-members. Our thesis is based on a hermeneutic approach.

Detta examensarbete har genomförts i samarbete med Värmex AB där vi har haft Anders Ericsson som handledare, och Peter Hansson (Sweco) som handledare från skolan, Kungliga tekniska högskolan i Haninge.Idag är energianvändningen i flerbostadshus en stor fråga att ta itu med, och för varje byggnadsprojekt skall en energideklaration som visar mängd köpt energi göras. Vi strävar idag efter att minska energianvändningen i flerbostadshus med 50 % till 2050. I denna analys beskriver vi vilka åtgärder man kan ta an för att minska just energianvändningen i ett specifikt flerbostadshus belägen i kommunen Nacka i Stockholm.Då denna byggnad stått från år 1949 utan större underhållning har det visat sig att byggnaden står över BBRs krav gällande energianvändning (90 kWh/m2), och stor anledning är klimatskalet. Källor visar även att delar av klimatskalet så som fasad etc. bör ändras inom 30 år efter det att det byggts, vilket inte har gjorts.Vi har genom en programvara, VIP-Energy valt att utföra denna analys.

BackgroundThere are different organizational structures and control and it has been proved difficult to find a combination between these that leads to goal congruence and improved efficiency. An organization can be structured according to hierarchical levels and the decision making can be either centralized or decentralized. Organizational control can be classified according to the amount of rules and balanced scorecard can be used to weld together the structure with the control.PurposeThe purpose is to create an understanding of how two types of structures and control in an organization appears and also to investigate how these differ from one another concerning the balanced scorecard as a control system. We will also investigate how the variables goal congruence and efficiency are affected by the implementation of the balanced scorecard.MethodTo answer the purpose of this thesis we have mainly used the qualitative method since we have studied two organizations thoroughly through interviews on different levels of the organization. The study also has some quantitative elements since we wanted to get a more truthful picture of the organizations.

This thesis is based on a case study for the real estate manager Mimer in Västerås. Mimer provides a great deal of this city?s rental apartments. Many of their buildings have ventilation systems with a type of heat-recovery called ?heatpipe?.

This project operate an environmental assessment of total waste was conducted by using a life cycle assessment (LCA), that examines the environmental benefits of recycling production waste from Atlas Copco at Stena recycling. Atlas Copco is a company engaged in the development and production of rig-mounted hydraulic breakers and handheld air breakers and handheld motorized rotisserie. Stena recycling is a recycling company engaged in recycling, processing and refining of metals, paper, electronics waste and hazardous waste.The purpose of this study is to focus on Stena customer Atlas Copco and evaluate environmental benefits between to recycle and not to do it. The result shows that the total energy gain, resulting from the recycling of waste fractions, lands at 6 990 089 MJ, corresponding to drive 3 times around the Equator with a truck (40 t). The result shows that recycling 3040 kg paper provides an energy gain of (38 600 MJ) compared with burning paper (19 500 MJ) is 19 100 MJ, which corresponds to heat a house for 11 weeks.

Wind power is an energy source that is becoming increasingly popular in Sweden and around the world. The establishment of large wind farms supply and contributes to energy production within grid in search of a more sustainable energy production. Wind power is becoming more popular and opens up new areas of implementation. More cities are starting to use small-scale urban wind power, everything from full-scale work for a little less work adapted to the villas. Sweden has high goals regarding the production of green electricity and the work which deals with the conditions Sweden plays in achieving those goals.

This is a work that look at the factors that affect future monthly costs when buying a house in Sweden and which options are the most financially favorable over a 30 year period. The work also examines whether it is economically beneficial to invest in a low-energy house regardless of geographic location in Sweden, and discuss about whether a calculation template can help individuals to choose more environmentally friendly options. The work has been limited so that a certain number of predetermined factors and its measurable values have been developed with the help of a literature study. The factors chosen are building type, climate, heating systems, loan interest rates, energy prices, energy price increases, inflation rates and down payment. These are then combined into 72 different calculation cases which get put in a calculation model made in excel.

This thesis is made by Carl Persson and Alejandro Saavedra for Gryaab. Gryaab is Gothenburg?s water processing plant and produces about 60 GWh biogas annually with a flow around 1150 Nm3/h. Gryaab wants to research their possibilities to become independent with electrical energy and the possibilities to enrich, upgrade biogas. The use of methane rich gases like biogas and natural gas is today low in Sweden compared to major parts of the world.