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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

New Generation Surface treatment for tools : A preliminary study

Massoud, George January 2013 (has links)
The surface finishing technique called black oxidation is currently being used on the tool holders made of low alloyed tool steel produced by Sandvik Coromant. Black oxidation isn’t considered a sufficient technique because it doesn’t make the tool holders look like the quality products that they actually are. The reasoning behind this is that the tool holders can show signs of corrosion after prolonged storing times or in countries with high humidity and temperature. The corrosion doesn’t decrease the tool holders performance, but the customers might believe otherwise. After the black oxidation is performed the surface is oiled which can cause sticky surfaces that rubs off on the person handling the tool holders which is also something that needs to be avoided. The aim of this master thesis was to study potential substitutes to the current surface finishing technique, which could primarily improve the tool holders corrosion resistance and appearance. Other material properties have been studied as well such as hardness, friction coefficient, fatigue- and wear resistance. The cost of some of the different surface finishing techniques has been studied as well, because in order to be interesting their price must match what improvements the technique provides with. A preliminary study was done where the surface finishing techniques that are available in the market has been examined. This has been a theoretical study which means that no experiments were performed and that most of the information available in this study has been obtained from literature and scientific articles. Companies that work with surface finishing has been contacted which shared information about both the theoretical and practical aspects of finishing techniques. Electro- and electroless plating are the two techniques which seem most suited for the replacement of the current method, black oxidation. Polishing and electropolishining can be suitable aswell, but the corrosion resistance barely increases.
2

Nya träfiberbaserade material = nya formgivningsmöjligheter?

Carlsson, Hanna January 2019 (has links)
Denna studie har fokuserat på materialutveckling genom att undersöka hur ett träfiberbaserat material skulle kunna utformas för att göra det möjligt att skapa dubbelkrökta ytor på ett hållbart sätt. Fördjupningsområden i studien har varit material och produktdesign samt hållbar utveckling. Till studien har ett projekt genomförts utifrån metoden Material Driven Design. Resultatet blev ett material komponerat av restmaterial från andra produktioner. Spånfibrer från träverkstäder samt benlim som tillverkas av rester från slaktindustrin har använts för att skapa ett gjutbart, träfiberbaserat och helt organiskt material. Resultatet av materialutvecklingen applicerades på ett produktkoncept för att visa hur materialet skulle kunna användas samt för att ge en bild av hur materialutveckling och produktdesign kan samspela för att öppna nya formgivningsmöjligheter. / This study has focused on material development to investigate how a new wood fiber-based material could be designed to make it possible to create double-curved surfaces in a sustainable way. Areas that has been focused on in the study have been materials and product design and sustainable development. A project has been carried out for the study based on the method Material Driven Design. The result was a material composed of residual material from other productions. Chip fibers from wooden workshops as well as bone adhesives made from residues from the slaughtering industry have been used to create a castable, wood fiber based and completely organic material. The result of the material development was applied to a product concept to show how the material could be used and to give a picture of how material development and product design can interact to open new design possibilities.
3

Musslor som material – En studie om att använda musslor för material utveckling genom en materialdriven designprocess för en cirkulär ekonomi

Andersson, Sara January 2020 (has links)
Blåmusslor livnär sig på att filtrera vatten på alger och partiklar, som i sin tur tagit upp kväve och fosfor. Genom odling, skörd och effektiv användning av musslorna kan man hjälpa till att minska närsaltsbelastning och övergödning i Öresund. Syftet med denna studie har varit att undersöka möjligheterna att använda en materialdriven designprocess för framtagning av material för en cirkulär ekonomi genom att tillämpa råmaterialet musslor. Fördjupningsområden i studien har varit att studera teorier kring design för hållbar utveckling, cirkulär ekonomi och materialdriven design. Genom en materialdriven designprocess har ett biologiskt nedbrytbart materialet tagits fram som har potential att ingå i en cirkulär ekonomi. Resultatet av materialframtagningen presenteras i form av ett materialkoncept som representerar materialets tekniska och sensoriska egenskaper. / Mussels feed on filtering water on algae and particles, which in turn have absorbed nitrogen and phosphorus. By cultivating, harvesting and efficient use of the mussels, you can help reduce eutrophication in the Sound. The purpose of this study has been to investigate the possibilities of using material driven design processes for creating new materials, for a circular economy by applying the raw material mussels. The main areas of study have been theories within design for sustainable development, circular economics and material driven design. Through a material driven design process, a biodegradable material has been developed that has the potential to be part of a circular economy. The result of the material development is presented in the form of a material concept that represents the technical and sensorial properties of the material.
4

Sequential Machine Learning in Material Science / Sekventiell maskininlärning inom materialvetenskap

Bellander, Victor January 2023 (has links)
This report evaluates the possibility of using sequential learning in a material development setting to help predict material properties and speed up the development of new materials. To do this a Random forest model was built incorporating carefully calibrated prediction uncertainty estimates. The idea behind the model is to use the few data points available in this field and leverage that data to build a better representation of the input-output space as each experiment is performed. Having both predictions and uncertainties to evaluate, several different strategies were developed to investigate performance. Promising results regarding feasibility and potential cost-cutting were found using these strategies. It was found that within a specific performance region of the output space, the mean difference in alloying component price between the cheapest and most expensive material could be as high as 100 %. Also, the model performed fast extrapolation to previously unknown output regions, meaning new, differently performing materials could be found even with very poor initial data. / I denna rapport utvärderas möjligheten att använda sekventiell maskininlärning inom materialutveckling för att kunna prediktera materials egenskaper och därigenom förkorta materialutvecklingsprocessen. För att göra detta byggdes en Random forest regressionsmodell som även innehöll en uppskattning av prediktionsosäkerheten. Tanken bakom modellen är att använda de relativt få datapunkter som generellt brukar vara tillgängliga inom materialvetenskap, och med hjälp av dessa bygga en bättre representation av input-output-rummet genom varje experiment som genomförs. Med både förutsägelser och osäkerheter att utvärdera utvecklades flera olika strategier för att undersöka prestanda för de olika kandidatmaterialen. Genom att använda dessa strategier kunde lovande resultat vad gäller genomförbarhet och potentiell kostnadsbesparing hittas. Det visade sig att, för specifika prestandakrav, den genomsnittliga skillnaden i pris mellan den billigaste och den dyraste materialkemin kan vara så hög som 100 %. Vad gäller övriga resultat klarade modellen av att snabbt extrapolera initial data till tidigare okända regioner av output-rummet. Detta innebär att nya material med ny typ av prestanda kunde hittas även med mycket missanpassad initial träningsdata.
5

A Gradient Boosting Tree Approach for Behavioural Credit Scoring / En gradientförstärkande trädmetod för beteendemässig kreditvärdering

Dernsjö, Axel, Blom, Ebba January 2023 (has links)
This report evaluates the possibility of using sequential learning in a material development setting to help predict material properties and speed up the development of new materials. To do this a Random forest model was built incorporating carefully calibrated prediction uncertainty estimates. The idea behind the model is to use the few data points available in this field and leverage that data to build a better representation of the input-output space as each experiment is performed. Having both predictions and uncertainties to evaluate, several different strategies were developed to investigate performance. Promising results regarding feasibility and potential cost-cutting were found using these strategies. It was found that within a specific performance region of the output space, the mean difference in alloying component price between the cheapest and most expensive material could be as high as 100 %. Also, the model performed fast extrapolation to previously unknown output regions, meaning new, differently performing materials could be found even with very poor initial data. / I denna rapport utvärderas möjligheten att använda sekventiell maskininlärning inom materialutveckling för att kunna prediktera materials egenskaper och därigenom förkorta materialutvecklingsprocessen. För att göra detta byggdes en Random forest regressionsmodell som även innehöll en uppskattning av prediktionsosäkerheten. Tanken bakom modellen är att använda de relativt få datapunkter som generellt brukar vara tillgängliga inom materialvetenskap, och med hjälp av dessa bygga en bättre representation av input-output-rummet genom varje experiment som genomförs. Med både förutsägelser och osäkerheter att utvärdera utvecklades flera olika strategier för att undersöka prestanda för de olika kandidatmaterialen. Genom att använda dessa strategier kunde lovande resultat vad gäller genomförbarhet och potentiell kostnadsbesparing hittas. Det visade sig att, för specifika prestandakrav, den genomsnittliga skillnaden i pris mellan den billigaste och den dyraste materialkemin kan vara så hög som 100 %. Vad gäller övriga resultat klarade modellen av att snabbt extrapolera initial data till tidigare okända regioner av output-rummet. Detta innebär att nya material med ny typ av prestanda kunde hittas även med mycket missanpassad initial träningsdata.
6

Äggskal,avfall eller resurs? : En materialdriven designprocess

Sofee, Sofidar January 2021 (has links)
Egg consumption in Sweden is very high, which means a lot of egg shells are thrown out. For example the average swede consumes about 350 eggs every year. In this thesis I have investigated how eggshells can be applied in new areas as a resource, and I want to inspire the reader and encourage them to rethink what is called waste. Is it really waste or a possible resource? The work began with literature search, interviews and a survey to understand people's views on eggshells. I have concluded that not a lot of people know what eggshells are made of, and what they are used for. In a literature search I came across many scientific articles on eggshells. According to King’ori (2011) eggshells are used as fertilizers, used in medicine, cosmetic surgery, and dental care, calcium supplements, in the food industry and in crafts. When eggshell is thrown as food waste it creates problems in recycling stations, the eggshell is like sediment and lies at the bottom of tanks and pipes. The recycling staff have to perform additional work when cleaning tanks and pipes as eggshells are like sediment and lay at the bottom. The staff have to manually shoot out eggshells with many other useful materials that could have been digested and become biogas. This is an exploratory thesis where I investigate the material eggshell through a material-driven design process to find new sustainable uses. I follow the material-driven design process method by Karana et al.( 2015) plus my own added steps during the process. Material driven design process is a process where designers use a material to find the attributes of the material. These are then presented in new contexts or already existing contexts, this means that the material on the existing product can be replaced. This differs from traditional design, where the material is chosen based on wanted attributes. This report will give you an understanding of the material-driven design process-method and how I have carried out a material-driven design process, to develop different material properties of eggshells. The report ends with a concluding discussion and presents new eggshell-based materials that I have produced in the form of a demonstrator. It is a book which has two different materials, a hard material and a paper material which are combined and put together with a steel thread. I will also share my knowledge about eggshells and what potential it has in the future.

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