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- Andersson, Oscar, 1968-
(författare)
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Digital process planning of joining by numerical models in the automotive industry
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The automotive industry is striving towards reduction of greenhouse gas emission by reducing product weight and improving fuel efficiency of their products. The introduction of lightweight materials have imposed greater pressure not only on the product development but also on manufacturing systems. One integral aspect of manufacturing systems, which is meeting these challenges is joining technology. In order to achieve successful joining of new automotive products, joining process planning must be equally successful.This research aims at improving process planning of joining by introducing digital tools into the process planning work method. The digital tools are designed to reduce lead times and increase accuracy of the process planning to realize more advanced, complex and environmentally friendly product solutions in the vehicles of the future.The research has two main focuses. Firstly, the joining process planning structure and organization have been analysed. The analysis has identified specific instances where digital tools can be introduced to improve the process planning and make it more efficient. Digital tools, such as numerical models for prediction and databases for re-use of knowledge, have been suggested for the process planning. An assessment of the impact of the introduction of these tools in an industrial test case has been performed to show the possible reduction in lead times.Secondly, geometrical distortions due to laser beam welding have been investigated, both by experimental trials and numerical modelling. The influences of design and process parameters on the distribution and magnitude of geometrical distortions have been established. Numerical models of different modelling detail and complexity have been developed and evaluated in order to find modelling approaches with reduced computation times aimed at industrial implementation. The predictive accuracy and computational efficiency of the numerical models have been assessed and evaluated with regard to industrial implementation.
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| 2. |
- Andersson, Oscar, 1968-
(författare)
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Italiensk-amerikaner i Bostons North End : En omanalys av William Foote Whytes fältanteckningar
- 2022. - 1
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Bok (refereegranskat)abstract
- I sin nya bok gör Oscar Andersson en omanalys av William Foote Whytes fältanteckningar från hans klassiska fältstudie Street Corner Society från 1943, som utspelar sig i Bostons stadsdel North End under andra hälften av 1930-talet. Att få tillgång till en annan antropologs kompletta samling fältanteckningar är unikt. Antropologer ser fältanteckningar som sin intellektuella egendom och det finns ingen utomstående som kan kräva att få se dem. Forskning har visat att antropologer oroar sig över att fältanteckningarna – vid en jämförande analys – inte validerar etnografin, vilket gör att de ogärna lämnar ut dem. Bill Whyte var tvärtom en tillitsfull person som såg det som en självklarhet att efterkommande forskargenerationer skulle få tillgång till hans ocensurerade fältanteckningar. Whytes oredigerade fältanteckningar och banbrytande observationsmetoder analyseras ingående i denna studie av Oscar Andersson. Bill Whytes fältanteckningar har använts analytiskt för att historiskt beskriva och teoretiskt förklara italiensk-amerikaners kultur i Bostons North End i teman som både överlappar och skiljer sig från Whytes. Dessa teman binds samman av rumsliga och temporala grupphändelser, och innefattar den stora depressionen under 1930-talet, emigrationen från Italien till USA, stadsdelen North Ends befolkningsutveckling, lokalpolitik, organiserad brottslighet, arbetsmarknadskonflikter, social rörlighet och gruppkonflikter som kunde blossa upp i det gäng av cornerboys, som Bill Whyte umgicks med i North End. En händelse som också ingående återberättas är mobiliseringen av invånarna för att protestera mot stadsdelens sanitära och hygieniska missförhållanden som befolkningen tvingades leva under.
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| 3. |
- Andersson, Oscar, 1968-
(författare)
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The Moral System of Corner boys and College boys in Boston’s North End During the Great Depression of the 1930s : A Reinterpretation of William Foote Whyte’s Street Corner Society Based on His Fieldnotes and an Unpublished Case Study
- 2021
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Ingår i: Journal of the North End Historical Society. - Boston : North End Historical Society. - 9780578831329 ; , s. 23-49
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Bokkapitel (refereegranskat)abstract
- The article is about the attitudes of corner boys and college boys’ to social mobility, showing that the 1930s was a watershed era. The first generation of Italians were often farmers and fishermen who became industrial workers in the United States. The second generation of Italians had adapted to American cultural conditions to varying degrees, with commitments in both the local community and the majority society. Corner boys planned for a future in the local community. College boys strove to pursue a career outside the social and geographical boundaries of the community. Corner boys learned the rules of society on the street. College boys were handpicked at school and in the settlement house to become middle-class Americans. Corner boys regarded college boys as hypocrites who put their short-term interests before those of the local community. The schisms between corner boys and college boys were an indication that the family values of the local Italian community were changing. But it was not until some time after the Second World War that the third and fourth generations of Italians had acquired moral values similar to those of the average American about abortion, mixed marriages, homosexuality, sexual abstinence before marriage, and divorce.
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| 4. |
- Creed, Irena F., et al.
(författare)
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Global change-driven effects on dissolved organic matter composition : Implications for food webs of northern lakes
- 2018
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 24:8, s. 3692-3714
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Forskningsöversikt (refereegranskat)abstract
- Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change-driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice-out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans.
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| 5. |
- Fahlström, Karl, 1986-, et al.
(författare)
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Metallurgical effects and distortions in laser welding of thin sheet steels with variations in strength
- 2017
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Ingår i: Science and technology of welding and joining. - : Informa UK Limited. - 1362-1718 .- 1743-2936. ; 22:7, s. 573-579
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Tidskriftsartikel (refereegranskat)abstract
- Geometrical distortions occur while welding, but the understanding of how and why they occur and how to control them is limited. The relation between the weld width, weld metal volume, total energy input, width of hard zone and distortions when laser welding three different thin sheet steels with varying strength has therefore been studied. Weld metal volume and total energy input show a good correlation with distortion for one steel at a time. The best correlation with the when including all three steel grades was the width of the hard zone composed of weld metal and the martensitic area in the heat affected zone. © 2017 Institute of Materials, Minerals and Mining.
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