The project covers the substitution of a stamping shut height measurement at the chainsaw chain factory Husqvarna Edge, with a new sensor-based processmonitoring system, set to increase productivity and decrease running costs. The workflow covers the span from external and needs analysis to development and testing of both hardware and software, in conjunction with communication with external suppliers to find the most usable and profitable solution going forward. Regarding hardware was inductive / eddy-current distance measurement sensors the most suitable for the stamping press environment, providing high sample rate and repeatability to a micrometre level, while subjected to oil andvibration. Husqvarna’s state of the art stamping setup is not yet fully supported by process monitoring suppliers, which resulted in the creation of the new program called Live Height, which was successfully used for sensor evaluation and serves as an example for suppliers to expand upon. This work provides several options in different price ranges for Husqvarna’s management to make decisions upon.

Diploma thesis deals with the topic of monitoring and directing financial costs in chosen company. First part of thesis describes theoretical basis and connects the knowledge of different fields, which complete the knowledge of general economic theory. This part defines basic terms and relationships between different quantities. Second part of the thesis describes the costs of the companies and the methods of the calculation of the costs. Thesis specifically focuses on chosen products. In this place, specifically the microeconomic evidence is used, such as break-even point or shut-down of the production in the short and long term. On the basis of this cost Analysis I created some recommendations concerning the purchase of materials, cost calculation, sale price and the quantity.

The topic of this thesis is the degradation of fuel cell electrodes in proton exchange membrane fuel cells (PEMFCs). In particular, the degradation associated with localized fuel starvation, which is often encountered during start-ups and shut-downs (SUs/SDs) of PEMFCs. At SU/SD, O2 and H2 usually coexist in the anode compartment. This situation forces the opposite electrode, i.e. the cathode, to very high potentials, resulting in the corrosion of the carbon supporting the catalyst, referred to as carbon corrosion. The aim of this thesis has been to develop methods, materials and strategies to address the issues associated to carbon corrosion in PEMFC.The extent of catalyst degradation is commonly evaluated determining the electrochemically active surface area (ECSA) of fuel cell electrode. Therefore, it was considered important to study the effect of RH, temperature and type of accelerated degradation test (ADT) on the ECSA. Low RH decreases the ECSA of the electrode, attributed to re-structuring the ionomer and loss of contact with the catalyst.In the search for more durable supports, we evaluated different accelerated degradation tests (ADTs) for carbon corrosion. Potentiostatic holds at 1.2 V vs. RHE were found to be too mild. Potentiostatic holds at 1.4 V vs. RHE were found to induce a large degree of reversibility, also attributed to ionomer re-structuring. Triangle-wave potential cycling was found to irreversibly degrade the electrode within a reasonable amount of time, closely simulating SU/SD conditions.Corrosion of carbon-based supports not only degrades the catalyst by lowering the ECSA, but also has a profound effect on the electrode morphology. Decreased electrode porosity, increased agglomerate size and ionomer enrichment all contribute to the degradation of the mass-transport properties of the cathode. Graphitized carbon fibers were found to be 5 times more corrosion resistant than conventional carbons, primarily attributed to their lower surface area. Furthermore, fibers were found to better maintain the integrity of the electrode morphology, generally showing less degradation of the mass-transport losses. Different system strategies for shut-down were evaluated. Not doing anything to the fuel cell during shut-downs is detrimental for the fuel cell. O2 consumption with a load and H2 purge of the cathode were found to give around 100 times lower degradation rates compared to not doing anything and almost 10 times lower degradation rate than a simple air purge of the anode. Finally, in-situ measurements of contact resistance showed that the contact resistance between GDL and BPP is highly dynamic and changes with operating conditions. / Denna doktorsavhandling behandlar degraderingen av polymerelektrolytbränslecellselektroder. polymerelektrolytbränslecellselektroder. Den handlar särskilt om nedbrytningen av elektroden kopplad till en degraderingsmekanism som heter ”localized fuel starvation” oftast närvarande vid uppstart och nedstängning av bränslecellen. Vid start och stopp kan syrgas och vätgas förekomma samtidigt i anoden. Detta leder till väldigt höga elektrodpotentialer i katoden. Resultatet av detta är att kolbaserade katalysatorbärare korroderar och att bränslecellens livslängd förkortas. Målet med avhandlingen har varit att utveckla metoder, material och strategier för att både öka förståelsen av denna degraderingsmekanism och för att maximera katalysatorbärarens livslängd.Ett vanligt tillvägagångsätt för att bestämma graden av katalysatorns degradering är genom mätning av den elektrokemiskt aktiva ytan hos bränslecellselektroderna. I denna avhandling har dessutom effekten av temperatur och relativ fukthalt studerats. Låga fukthalter minskar den aktiva ytan hos elektroden, vilket sannolikt orsakas av en omstrukturering av jonomeren och av kontaktförlust mellan jonomer och katalysator.Olika accelererade degraderingstester för kolkorrosion har använts. Potentiostatiska tester vid 1.2 V mot RHE visade sig vara för milda. Potentiostatiska tester vid 1.4 V mot RHE visade sig däremot medföra en hög grad av reversibilitet, som också den tros vara orsakad av en omstrukturering av jonomeren. Cykling av elektrodpotentialen degraderade istället elektroden irreversibelt, inom rimlig tid och kunde väldigt nära simulera förhållandena vid uppstart och nedstängning.Korrosionen av katalysatorbäraren medför degradering av katalysatorn och har också en stor inverkan på elektrodens morfologi. En minskad elektrodporositet, en ökad agglomeratstorlek och en anrikning av jonomeren gör att elektrodens masstransportegenskaper försämras. Grafitiska kolfibrer visade sig vara mer resistenta mot kolkorrosion än konventionella kol, främst p.g.a. deras låga ytarea. Grafitiska kolfibrer visade också en förmåga att bättre bibehålla elektrodens morfologi efter accelererade tester, vilket resulterade i lägre masstransportförluster.Olika systemstrategier för nedstängning jämfördes. Att inte göra något under nedstängning är mycket skadligt för bränslecellen. Förbrukning av syre med en last och spolning av katoden med vätgas visade 100 gånger lägre degraderingshastighet av bränslecellsprestanda jämfört med att inte göra något alls och 10 gånger lägre degraderingshastighet jämfört med spolning av anoden med luft. In-situ kontaktresistansmätningar visade att kontaktresistansen mellan bipolära plattor och GDL är dynamisk och kan ändras beroende på driftförhållandena. / <p>QC 20131104</p>

Introduciton. The aim of this master’s thesis is to investigate whether the Library Outreach Service (Boken kommer), a home-library-service, contributes positively to how the users’ experience their life quality. Method. This study is based on semi-structured interviews with ten Boken kommer-users, a smaller qualitative survey and one interview with the librarian in charge of the home-library-service in the Swedish municipality Norrtälje. Analysis. The theoretical framework used for the analysis in this study is based on the results from two different studies that define life quality for people over the age of 65. These results are used to explain and understand the users’ experiences and perceptions of whether the service has a positive impact on their perceived quality of life. Results. The analysis identifies several themes that were brought up by the users in the interviews and in the survey. These themes covered a social aspect, to be part of the community, the access to literature, the possibility to participate in different ways and their perception of what is meaningful in their lives. These themes can all contribute to life quality.  Conclusion. The findings indicate that users find the home-library-service to contribute positively to their experienced life quality and that the service is a very important element in their lives. Limitations. As this study draws its findings from a small sample selection, general conclusions are limited and further studies of larger groups in a broader context with this perspective would make a good contribution to research. This is a two-year master’s thesis in Library and Information Science.

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