<p>This study focuses on the wear of piston rings in a hydraulic radial piston motor. The piston ring has to satisfy increasing demands for reliability and longer service life. It has two contacting surfaces, the face and the flank, and operates under a boundary lubrication state.</p><p>This first part of the project aimed to detect and characterise piston ring wear. Measurement by weighing gives an overall value for wear defined as loss of mass. Two-dimensional form and surface roughness measurements show the distribution of wear on the piston ring face in contact with the cylinder bore and the piston ring flank in contact with the piston groove. Three-dimensional analyses, both quantitative and qualitative, allow the wear mechanisms to be identified.</p><p>The wear of piston rings from an actual hydraulic motor was characterised. As well, rig testing was performed in two different test rig set-ups, one simulating the sliding movement of the piston ring and the other the tilting movement at the end of the strokes. Wear during the running-in period was investigated, and the findings indicate that the period when this takes place is of short duration. In the long term, mild wear makes the surfaces smoother than they were when new, resulting in a very low wear coefficient. Significant levels of wear were measured on both contacting surfaces of the piston ring. In cases in which the flank exhibits more wear than the face, the wear on the flank can be reduced by proper design of the piston groove.</p><p>The second part of the project aimed to evaluate use of a textured surface for the cylinder bore counter surface and a coated surface for the piston ring. Three modelling experiments were performed to characterise the friction and wear properties under lean boundary lubrication conditions. Under such conditions, textured surfaces have the advantage of retaining more lubricant and supplying it over a longer time. Stable friction was also a distinctive feature of the textured surface. Use of a coating could also possibly reduce the amount of wear. Though a smooth surface, like a polished one, is hard to beat for a working texture, a coated surface is far ahead of a smooth uncoated one. Different manufactured and commonly used cylinder bore surfaces, including textured ones, were evaluated in the sliding movement test rig. That allowed favourable wear properties, such as lowest wear coefficient, to be determined with the use of a roller burnished surface.</p><p>A final part of the research involved simulating wear on the piston ring face throughout the entire service life of a hydraulic motor. This allowed us to determine the roles of surface roughness and coating in prolonging service life and achieving acceptable and secure piston ring operation. The model is simple and realistic, but still needs to be refined so as to correspond even better to reality.</p>

<p>Because of increasing environmental demands, especially on dealing with products end of life phase, product manufacturers and designers must consider the future disposal of their products. For conventional materials like steel and aluminium well-functioning recycling methods exists. This is not the case for structures of polymer composites, which are used more extensively, especially for structures like vehicles and vessels. Several techniques do exist but they are not yet commercially available. The current disposal methods of polymer composites are landfill and incineration.</p><p>Polymer composites are materials, which consist of several materials like fibre, matrix, and additives. In the form of sandwich constructions also foam core material is added. This circumstance complicates the waste treatment of composite materials. In this thesis a model for assessing possible future waste treatment techniques for polymer composites including sandwich structures is presented. The model is meant to be used as an aid for preparing future disposal for end of life products for planning waste treatment and for facilitating communication in contacts with waste receivers.</p><p>Recommendations for waste treatment have been formed for a number of polymer composites. These recommendations are based on the analysis of costs and environmental effects and they compare different scenarios for mechanical material recycling and energy recovery by waste incineration. The result of this study points out material recycling as the preferable method for the main part of the studied materials. But this recommendation is strongly dependent on type of virgin material replaced by the recycled material. Energy recovery can also be considered if the polymer composite waste replaces coal, which is non renewable. Though incineration will always result in a cost for the waste producer.</p><p>In the recommendations mentioned above no information concerning implementation of the different waste disposal techniques is included. Therefore, in this study a model for assessing possible waste disposal techniques for polymer composites is presented. The model is based on internal factors, which are related to the waste and to the processes. To implement the model relevant waste properties must be identified in order to fulfil the conditions set by the required processes involved.</p><p>A case study was carried out using the proposed model for assessing different waste disposal techniques for the hull of the Visby Class Corvette in the Royal Swedish Navy. Six different techniques were studied for the hull structure. Since almost all the important waste properties were known and the waste was assessed to be treatable all the included techniques except one are shown to be usable in the future.</p><p>Many investigations have pointed out material recycling as the best alternative considering environmental effects. This is also valid for polymer composite materials. Since recycling polymer composites is a complicated process, especially recycling thermoset composite it is important to aquire comprehensive information about the constituents of these materials.</p>

<p>In recent decades much effort has gone into reducing particle emissions in the exhaust gases of heavy-duty diesel engines. Engine development has now reached the stage where it is worth to put heavy focus on the contribution of lubricating oil to particulate emissions in order to further reduce these emissions.</p><p> </p><p>A literature study demonstrates that the cylinder system is usually the largest source of oil-related particles. Oil consumption in the cylinder can be divided into <em>throw-off</em> effects when inertia forces act on the piston, piston rings and oil; <em>evaporation</em> from hot surfaces; <em>reverse blow-by</em> when gas pressure drives the oil consumption; and <em>top land scraping </em>when oil is scraped off the cylinder liner.</p><p> </p><p>The pressure between the compression rings strongly affects the stability and position of the upper compression ring as well as the oil consumption caused by the reverse blow-by. A method to measure the inter-ring pressure was developed and evaluated. The measurements showed that cycle-to-cycle variations were small, but that the inter-ring pressure varied over time. Calculations with AVL Excite Piston and Rings confirmed that ring gap positions can have a major influence on the inter-ring pressure.</p><p> </p><p>The measured particle size and number distributions at motoring conditions show interesting and unexpected results. The high number of particles with a diameter of around 100 nm was greatly reduced when the temperature in the diluter was increased. The mean number particle diameter decreased until 10 nm and then became stable independent of further temperature increase. Other authors have found that the small particles (nucleation mode) are reduced and the larger particles (accumulation mode) are more or less unaffected when exhaust gases are heated up and diluted.  </p><p> </p>

<p>This thesis has its origin in empirical evidence. Some Swedish companies claimed that despite having plenty of proposals for developing new products, they experienced problems when choosing from all those alternatives. Their problem was how to select among new ideas the ones for being developed and the ones to be rejected, how many projects to run according to their capacity, when to start a development project and when to stop one, and how to decide among ongoing projects which the most important ones were. The companies’ problem was decision making in the context of innovation.</p><p> According to literature, a deeper understanding is needed of the decision making process in innovation, taking into account its organizational and procedural complexities. The purpose of this thesis is to achieve an understanding of the decision making process in innovation.  The thesis is based on an explorative study, with interviews carried out in three companies that have new product development as a core competitive factor. The empirical study focuses on the decisions made for selection and prioritization of different innovative alternatives. </p><p>As a result of the analysis of the empirical data a conceptualization of the decision making process was developed. Furthermore, it was described the relevant problems that decision makers experience, the main characteristics of the decision making process and the role that decision making plays in innovation. The implications of these findings for designing work procedures to support decision making in innovation were discussed; and general descriptions of two practical methods suggested. </p><p>The main findings indicate that for making decisions in the context of innovation, organizations must be able to face uncertain and ambiguous situations, and achieve a collective understanding about what is to be done. To do this, different approaches for making decisions and understanding innovation are needed. However, regardless of the appropriateness of these approaches, they receive different levels of acceptance within organizations; and decision makers must deal with the different grades of organizational acceptance of the different approaches. As a consequence, an organization displays certain dynamic using different approaches for making decisions and for understanding innovation. Such dynamic influences the companies’ innovative potential and the output of the innovation process.</p>

<p>A modern diesel engine is capable of running efficiently with low exhaust gas emissions over a wide operating range. This is thanks to techniques such as turbocharging, EGR, charge air cooling and an advanced fuel injection process. The fuel injection process is important for the combustion and emission formation in the diesel engine. The fuel injector has to atomize and vaporize the fuel as it is injected. During the combustion the emission formation has to be kept to a minimum. Very strong pressure gradients are present in a modern diesel injection nozzle, this causes cavitation to occur in the nozzle holes. The influence of cavitation on flow parameters such as the various discharge coefficients is discussed. The occurrence of cavitation helps the spray break up and it can keep the nozzle holes free from deposits. Excessive amounts of cavitation can lead to hole erosion and thus impact the long term operation of the nozzle in a negative way. Hole erosion as well as other mechanisms can cause hole to hole variations in fuel spray impulse, mass flow, penetration etc. This is a very important issue in any low emission diesel engine, especially during transients, as less than optimal conditions have to be handled. The influence of hole to hole variation on fuel consumption and emissions is not very well known and this thesis contributes to the field. As a part of this work a fuel spray momentum measurement device was developed and tested. Any automotive engine needs to be able to perform quick transitions between different loads and speeds, so called transients. In a turbocharged diesel engine with EGR issues related to the turbocharger and the EGR-circuit arise. A diesel engine has to run with a certain air excess in order to achieve complete combustion with low emissions of soot. When turbocharging is used the turbocharger turbine uses some of the exhaust enthalpy to drive the turbo compressor, in this way the engine is provided with boost pressure. In order for the engine and turbocharger to function at the higher load and thus higher mass flow rate the turbocharger has to increase its rotational speed and the surface temperatures have to settle at a new thermodynamic state. Both of these processes take time and during this time the combustion process may have to proceed under less than optimum circumstances due to the low boost pressure.</p>

Syftet med uppsatsen är att diskutera om rekordårens bebyggelse kan med hjälp av en DIVE-analys betraktas som en del av kulturarvet. En kvalitativ metod har använts där observationer och historisk såväl som samtida litteratur varit grunden till empirin. Detta i enlighet med DIVE som undersökningsmetod. En kvalitativ analys med ett etnologiskt perspektiv har sedan gjorts. Uppsatsen utgår ifrån Grundad teori och behandlar således tidigare forskning kring kulturarvet, som begreppets karaktär och kulturarvets värden, i det avslutande kapitlet. Studien har resulterat i en analys av Hagalund i Solna stad, Stockholms län, vilket mynnar ut i ett resultat att Hagalund som en förort från rekordåren är ett kulturarv, dock enbart ur ett kunskapsperspektiv. Ur ett upplevelseperspektiv krävs helt andra metoder än DIVE för att utröna om Hagalund är ett kulturarv. Dessutom diskuteras DIVE-analysens förhållningssätt till kulturarvet och kulturarvet som objektivistiskt eller konstruktivistiskt betingat. Studien väcker flera nya frågeställningar kring kulturarvet och rekordårens bebyggelse.

De flesta spel som utvecklas i HTML5 använder en Canvas metod som ritar ut 2-D grafik. Med examensarbetet ville utvecklarna och examinatorn undersöka om det var möjligt att göra ett spel med bra prestanda utan att använda Canvas. Istället använde utvecklarna DOM-trädet och de nya funktioner som finns i CSS3 för att rita ut grafiken. Spelet som utvecklades heter Twofighter och är ett spel för två spelare på samma enhet exempelvis en surfplatta eller smartphone. Den ena spelaren styr ett rymdskepp som ska undvika eller plocka upp objekt som den andra spelaren placerar ut.

Detta arbete ägnar sig främst till alla lärare i grundskolan som undervisar i de samhällsorienterande ämnena, främst i religion. Under vår verksamhetsförlagda utbildning och vid arbete på diverse skolor har vi kunnat identifiera ett problem som är knutet till lärares identiteter och religionsundervisning. Syftet med detta arbete är att undersöka interaktionen mellan lärares identitetsarbete och religionsundervisning i hopp om att göra lärare medvetna om vikten av reflektion. Syftesformuleringen väcktes som en respons på lärares uttryck för deras erfarenheter i praktiken. Med beaktande av händelser i vår omvärld och samhällets förändrade dynamik blir det högst relevant att lärare visar medvetenhet för sitt identitetsarbete genom att synliggöra för sig själv hur deras kulturella bakgrunder och tro återspeglas i undervisningen.  Identitet, identitetsarbete och levnadsberättelser utgör centrala delar i detta arbete och är en förutsättning för besvarandet av arbetets frågeställningar. Semistrukturerade intervjuer gjorde det möjligt att undersöka sju lärares upplevelser av hur deras identitetsarbete påverkar religionsundervisningen. Analysen gjordes med hjälp av en tematisk analys med olika teman. Resultatet visade att identitetsarbete är viktigt och nödvändigt, men att det kan se olika ut. Detta beror på deras förståelse av sig själva och vilken plats deras personliga identitet får i undervisningen. Genom resultatet uppmärksammas även att identitetsarbete är en förutsättning för att lärares personliga värderingar ska kunna stå i linje med det yrkesmässiga ansvaret. Vidare fastställdes att levnadsberättelserna hade en stor påverkan på utformandet av den personliga identiteten där deras tidigare erfarenheter och värderingar kom till uttryck. Slutsatsen tyder på att lärarens självbild är kärnan i att kunna bedriva en icke-konfessionell undervisning. Det framgår även att det krävs en medveten reflektion för att kunna integrera personliga värderingar i det professionella tänkandet då lärares religiösa övertygelser inte kan uteslutas.

Philharmonie in der Frauenkirche Ralph Vaughan Williams (1872 – 1958) Five Variants of »Dives and Lazarus« Sarah Christ | Harfe Hamilton Harty (1879 – 1941) Konzert für Violine und Orchester d-Moll Felix Mendelssohn Bartholdy (1809 – 1847) Sinfonie Nr. 3 a-Moll op. 56 »Schottische«

Philharmonie in der Frauenkirche Ralph Vaughan Williams (1872 – 1958) Five Variants of »Dives and Lazarus« Sarah Christ | Harfe Hamilton Harty (1879 – 1941) Konzert für Violine und Orchester d-Moll Felix Mendelssohn Bartholdy (1809 – 1847) Sinfonie Nr. 3 a-Moll op. 56 »Schottische«