Denna uppsats behandlar frågan kring fördomar, muslimer och interaktion. Undersökningen sker genom en intervjuundersökning där respondenterna får svara på frågor som berör deras syn på muslimer utifrån deras interaktionsnivå. Tidigare forskning säger att den socialt konstruerade bilden av muslimer är negativ, och att den upprätthålls av samhället, däribland filmindustrin. Som ramverk för att undersöka detta används socialkonstruktivismen och kontaktteorin. Kontaktteorin, som introduceras av Gordon Allport, säger att interaktion mellan grupper minskar fördomar genom att grupperna interagerar som jämbördiga och med gemensamma mål. Dessa grupper beskrivs som ingroup och outgroup. Uppsatsen behandlar således om interaktionen hos respondenterna påverkar perceptionen de har av muslimer i Sverige. Slutsatsen är att interaktionen hos respondenterna påverkar uppfattningen de har av muslimer. De respondenter som hade regelbunden kontakt med muslimer, uppfattade inte gruppen i negativa termer.

Für einen sicheren und zuverlässigen Betrieb des gesamten Elektroenergieversorgungs-systems ist der langzeitstabile und möglichst wartungsfreie oder wartungsarme Betrieb jeder einzelnen Komponente wichtig. Eine Wartung aller stromführenden Verbindungen ist aufgrund der Anzahl und ihrer Zugänglichkeit nicht möglich. Eine Großzahl der Verbindungen wird deshalb montiert und muss über die geforderte Lebensdauer der Anlagen von mehreren Jahrzehnten wartungsfrei funktionieren. Um dies gewährleisten zu können, müssen die richtigen Leiter- und Beschichtungswerkstoffe gewählt, eine langzeitstabile Konstruktion vorhanden, die richtige Montage durchgeführt und eine gesicherte Grenztemperatur für die gewünschte Lebensdauer unter Berücksichtigung der Umgebungsbedingungen bekannt sein. In dieser Arbeit werden stromführende Verbindungen betrachtet, die keinen Lichtbogen führen müssen. Es werden die wichtigsten Leiter- und Beschichtungswerkstoffe, die Kontaktphysik insbesondere von Flächenkontakten, der Zusammenhang zwischen mechanischem und elektrischem Kontaktverhalten, die Physik der Alterung und die Wirkung auf das Langzeitverhalten bei unterschiedlichen Einsatz- und Umgebungsbedingungen betrachtet. Basierend auf diesen Erkenntnissen werden genormte Prüfverfahren bewertet und Ansätze zum Weiterentwickeln vorgestellt. Die Erkenntnisse dieser Arbeit basieren auf Ergebnissen, die in 40 Jahren Forschung an der TU Dresden erarbeitet wurden. Als Modellgeometrie für die grundlegenden experimentellen Untersuchungen wurden insbesondere Schrauben¬verbindungen mit Stromschienen verwendet, da diese Verbindungsart eine der am häufigsten verwendeten ist und millionenfach im Elektroenergieversorgungssystem eingesetzt wird.:1 Einleitung 2 Funktion und Anforderung an stromführende Verbindungen 3 Kontaktwerkstoffe 3.1 Leiter 3.2 Beschichten von Leitern 4 Kontaktverhalten von Schraubenverbindungen 4.1 Physikalische Grundlagen zum Flächenkontakt 4.2 Schraubenverbindung mit Stromschienen 4.2.1 Mechanisches Kontaktverhalten 4.2.2 Elektrisches Kontaktverhalten 4.2.3 Zusammenhang elektrisches und mechanisches Kontaktverhalten 4.2.4 Montage stromführender Verbindungen 4.2.5 Verallgemeinern der gewonnenen Erkenntnisse 5 Langzeitverhalten von Schraubenverbindungen 5.1 Alterungsmechanismen 5.1.1 Kraftabbau 5.1.2 Diffusion 5.1.3 Chemische Reaktionen 5.1.4 Reibverschleiß 5.1.5 Elektromigration 5.2 Mathematische Ansätze zum Beschreiben der Alterung 5.3 Experimentell ermittelte Lebensdauerkennlinien 5.3.1 Typische Lebensdauerkennlinie von Schraubenverbindungen 5.3.2 Leiterwerkstoffe - Aluminium, Kupfer und deren Legierungen 5.3.3 Beschichtungswerkstoffe - Silber, Nickel, Zinn 6 Prüfverfahren 7 Zusammenfassung und Ausblick 8 Literaturverzeichnis 9 Abbildungsverzeichnis 10 Tabellenverzeichnis / For a safe and reliable operation of the electric power supply system, the long-term stable and low-maintenance or maintenance-free operation of each component is important. Maintenance of all current-carrying joints is not possible due to their number and accessibility. A large number of joints is installed and must operate during the required life-time of the system of several decades maintenance-free. In order to warrant this, the appropriate conductor and coating material must be selected, a long-term stable construction design must be provided, the correct installation must be guaranteed, and a safe temperature limit for the desired life-time must be known according to the ambient conditions. In this work, non-arcing current-carrying joints are investigated. It considers the most important conductor and coating materials, the physics of surface contacts, the relationship between mechanical and electrical contact behavior, the physics of aging and the effects on the long-term behavior under different conditions of use and environmental conditions. Based on these scientific findings, standardized test methods are evaluated and approaches for further development are presented. The findings of this work are based on the results obtained in 40 years of research at the TU Dresden. As a model geometry for the basic experimental investigations bolted joints with bus bars are used, because this type of joint is one of the most commonly used millions of times in the electric power supply system.:1 Einleitung 2 Funktion und Anforderung an stromführende Verbindungen 3 Kontaktwerkstoffe 3.1 Leiter 3.2 Beschichten von Leitern 4 Kontaktverhalten von Schraubenverbindungen 4.1 Physikalische Grundlagen zum Flächenkontakt 4.2 Schraubenverbindung mit Stromschienen 4.2.1 Mechanisches Kontaktverhalten 4.2.2 Elektrisches Kontaktverhalten 4.2.3 Zusammenhang elektrisches und mechanisches Kontaktverhalten 4.2.4 Montage stromführender Verbindungen 4.2.5 Verallgemeinern der gewonnenen Erkenntnisse 5 Langzeitverhalten von Schraubenverbindungen 5.1 Alterungsmechanismen 5.1.1 Kraftabbau 5.1.2 Diffusion 5.1.3 Chemische Reaktionen 5.1.4 Reibverschleiß 5.1.5 Elektromigration 5.2 Mathematische Ansätze zum Beschreiben der Alterung 5.3 Experimentell ermittelte Lebensdauerkennlinien 5.3.1 Typische Lebensdauerkennlinie von Schraubenverbindungen 5.3.2 Leiterwerkstoffe - Aluminium, Kupfer und deren Legierungen 5.3.3 Beschichtungswerkstoffe - Silber, Nickel, Zinn 6 Prüfverfahren 7 Zusammenfassung und Ausblick 8 Literaturverzeichnis 9 Abbildungsverzeichnis 10 Tabellenverzeichnis

Mobile Miner 40V is a machine used for rock excavation and developed by Epiroc. This machine is equipped with a large cutter wheel to perform the excavation. After a test run, some surfaces associated with bearings within the cutter wheel were found to be damaged due to scuffing - severe sliding wear. There is a static load applied to the surfaces due to gravity. However, the reason for this damaged issue was believed that there is a large dynamic load applied to the surfaces during the excavation. This dynamic load was not found in a previous FE model used to verify safety issues. Therefore, a new FE model that is more in line with reality, and a failure analysis were required. Additionally, a feasibility study for a cutter wheel with a larger dimension was also needed since a larger cutter wheel is desirable. Firstly, wear mechanisms were reviewed, and some theories were chosen to analyze the damaged issue. Since it was unknown whether the surfaces were well-lubricated or not, both cases were investigated. The Archard wear equation was used to analyze the poor-lubricated situation, while the lubrication number and the Reynolds equation were used to analyze the well-lubricated case. Secondly, contact mechanisms between the surfaces were also investigated. The investigation of the contact mechanisms involved several theories, such as the Hertzian contact theory and the impact load factor. Besides these theoretical analyses, a numerical analysis was performed. Lastly, a new FE model was established in Ansys. Both the cutter wheel which was subjected to scuffing(existing cutter wheel), and the cutter wheel with a larger dimension(larger cutter wheel) were analyzed by the use of the new FE model. The maximum and minimum wear rates obtained by the Archard wear equation are approximately 1.9・10-2mm3/m and 4.8・10-3mm3/m, which are considered as a completely unacceptable level in engineering applications. The maximum and minimum critical loads obtained by the Reynold equation are approximately 1.8kN and 24.8kN, which both are larger than the static load applied to the surfaces. The maximum and minimum critical mean contact pressures obtained by the lubrication number are approximately 65MPa and 240MPa, which both are larger than the mean contact pressure generated by the static load. No evidence shows that there is a large dynamic load applied to the surfaces during the excavation. The largest possible contact pressure on the bearings in the existing cutter wheel is very close to the limit of severely damaged. The largest possible contact pressure on the bearings in the larger cutter wheel is believed to exceed the limit of severely damaged. The previous assumption that the surfaces were damaged due to a large dynamic load was wrong. The obtained results support that the surfaces were only subjected to a static load and were damaged due to inadequate lubrication. The existing cutter wheel is operated safely with the current load cases. However, the forward thrust force is suggested to decrease when the cutting angle is large. There is a high risk if the larger cutter wheel is operated with the current load cases.

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This thesis studies group threat theory and contact theory, by analysing whether a change in the exposure to refugees, following a demographic composition shift, results in increased or decreased political support for parties with either an anti- or a pro-immigration political program. It employs a continuous difference-in-difference method by analysing data from Swedish national elections in 2014 and 2018 across all municipalities, combined with the electoral performance of the Sweden Democrats and the Swedish Green Party. The findings reveal a positive correlation between increased refugee intake and the electoral support for the Sweden Democrats, while the Swedish Green Party experiences decreased support. This suggests a trend toward bolstered backing for anti-immigrant platforms in areas with greater refugee exposure, and thus also supports arguments presented within group threat theory. While intergroup contact with immigrants is a well-studied area, limited attention has been devoted to refugee immigration.  Finally, this thesis underscores the need for further investigation of the political and social ramifications of increased refugee immigration on native populations. This holds strong political relevance, as we are likely to continue experiencing high levels of immigration. A suggested way to build off this thesis is by studying the relevant mechanisms, or by establishing the extent and type of experienced intergroup contact.

Représentant entre 10 et 12 millions d’individus en Europe, les Roms sont confrontés à des discriminations et à l’exclusion sociale. 40% des Européens refusent d’avoir des Roms comme voisins, alors que 70% de ceux-ci n’entretiennent même pas de contact direct avec eux dans leur vie. Face à la problématique qu’offrent ces statistiques, cette étude entend observer les mécanismes de construction des attitudes envers les Roms. Je propose d’analyser la production de ces attitudes au sein de deux milieux similaires, mais où les politiques d’intégration locales envers les Roms divergent, rendant ainsi les conditions des contacts intergroupes différent. Cette analyse part des postulats scientifiques selon lesquels l’intégration des migrants est un enjeu d’action publique locale, et que les interactions sociales de qualité structurent les attitudes des uns par rapport aux autres. Ainsi, à partir d’entrevues semi-dirigées réalisées dans les communes françaises de La Courneuve et d’Ivry-sur-Seine, je teste de manière empirique quatre théories dominantes dans le domaine des relations intergroupes: la théorie du contact, l’effet halo, l’impact des politiques locales d’intégration des immigrants et l’influence des médias. / Representing between 10 and 12 million individuals in Europe, the Roma population faces discrimination and social exclusion. 40% of Europeans refuse to have Roma as their neighbors, while 70% of them do not even have direct contact with them in their lives. Based on these observations, this study analyses how attitudes towards Roma are constructed. I propose to investigate this mechanism in two similar environments, but where local integration policies towards Roma diverge, making the conditions of intergroup contact differ. The analysis is premised on two scientific assumptions: that the integration of migrants is a local public policy issue; and that intergroup contact structures attitudes between majority and minority cultures. Thus, from semi-structured interviews in the French communes of La Courneuve and Ivry-sur-Seine, I empirically test four dominant theories in the field of intergroup relations: contact theory, the halo effect, the impact of local immigrants integration policies, and media influence.

Background: Previous studies have consistently identified an association between higher levels of education and lower levels of anti-immigrant sentiment, but the underlying reasons for this relationship remain unclear. Therefore, this research aims to help explain why education matters for attitudes toward immigrants. This thesis consists of two studies, where in I examine the role of two features of education, specifically the aquistition of knowledge and social relationships. In the first study, I analyze how two aspects of teaching in schools are associated with anti-immigrant sentiment. I examine education as a means to knowledge by investigating whether the content of education, such as critical thinking and multicultural education, is inversely related to students' prejudice. I also look into the certification of teachers and whether this has a similar effect. In the second study, I investigate the school as an arena for social interaction and examine the relationship between outgroup contact and prejudiced attitudes. Previous research has found that outgroup contact, especially contact in the form of outgroup friendship, is effective in reducing prejudice. Based on these previous findings, I study how the Secondary Transfer Effect (STE) of friendship with a specific outgroup member is associated with attitudes towards other ethnic or racial groups. Method: The two studies rely on a cross-sectional survey of Swedish high school students (aged 16-18) administered by 'Forum för levande historia' (Forum for living history) and Statistics Sweden during the 2009-2010 academic year. Additionally, survey participants' responses are matched to registry data. This thesis also uses multilevel (MLM) and ordinary least squares (OLS) regression models. Results: Results show that both aspects of education are correlated with lower levels of anti-immigrant sentiment. The first study, in which education is a means to knowledge, demonstrates that education focused on critical thinking and multiculturalism are negatively correlated with anti-immigrant sentiment. Furthermore, results show that more exposure to teachings about xenophobia and racism is associated with less prejudice. However, when controlling for exposure to critical thinking, as well as learning about religions and cultures, the results show that exposure to learning about xenophobia and racism are no longer significant. Moreover, there is a negative association between exposure to teachers with a teaching certification or teaching degree and prejudice. Results from the second study, in which the school functions as an arena for social interaction, shows that positive attitudes associated with intergroup friendship not only generalize to the ethnic outgroup of that friend but, more importantly, also to other secondary outgroups. STEs are most frequently found where boundaries between ingroups and outgroups are perceived to be the thickest. Thus, the presence of STEs appears to be group-specific. Previous research on perceived social distance in Sweden and other countries help shed light on these findings. In summary, the results of this thesis provide evidence of two different complimentary accounts of the negative relationship between education and prejudice.

Ett företag som tillverkar hydrauliska snabbkopplingar har genom regelbundna kvalitetsprover upptäckt att vissa låskulor till snabbkopplingarnas låsmekanism plötsligt fått en bristande kvalité och spricker vid belastning. Låskulorna är gjorda av rostfritt stål och har en viktig funktion i låsmekanismen. Om de spricker vid användning kan det leda till konsekvenser med materiella skador eller personskador. Företaget vill förekomma eventuella kvalitetsproblem och måste därför säkerställa att låskulorna har rätt hållfasthet. Låskulorna köps in från en underleverantör och företaget vill därför utveckla en provmetod som provar låskulornas materialegenskaper när de levereras till fabriken. Arbetet i denna rapport syftar till att hjälpa företaget utveckla en sådan provmetod. Ett första steg är att undersöka orsaken till att låskulorna spricker. Materialanalyser utförs av ett materiallaboratorium för att fastställa vilka faktorer i materialet som orsakar brott i låskulorna. Analyserna visar att låskulorna sannolikt spricker på grund av en ökad sprödhet i materialet. Sprödheten beror på att martensiten i materialet är dåligt anlöpt samt en stor mängd karbider. Med orsaken till sprickorna fastställd undersöks befintliga metoder för materialprovning. En provmetod måste prova materialet i färdigtillverkade låskulor eftersom låskulornas tillverkningsprocess påverkar materialegenskaperna. Många av de standardiserade provmetoderna är dock svåra att tillämpa på låskulorna med anledning av låskulornas geometri och små dimensioner. En form av slagprov och pressprov utförs på låskulorna. Ett av syftena med proven är att undersöka om de är lämpliga att använda som provmetod. Genom proven framträder olika materialegenskaper för olika låskulor. Resultaten är dock inte jämförbara låskulorna emellan och proven anses inte vara lämpliga som provmetod. Även ett utmattningsprov utförs på låskulorna genom en upprepande belastning i en snabbkoppling. Detta prov är inte heller lämpligt att använda som provmetod då provet är mycket tidskrävande samt att det finns vissa osäkerheter kring provresultatet. I detta arbete undersöks även två nyligen framtagna provmetoder för kulor till kullager och möjligheten att tillämpa dessa provmetoder på låskulorna. I undersökningen jämförs de båda provmetoderna med avseende på utförande samt framtagning av provkropp. Även en spänningsanalys av en låskula belastad i en snabbkoppling utförs för att ta reda på i vilket område av låskulan de maximala spänningarna uppstår. Undersökningen ger att enbart en provmetod är intressant för fortsatt arbete.   Den provmetod som föreslås i detta arbete kallas "the notched ball test" (NBT). Provmetoden innebär att en djup och smal skåra bearbetas i en låskula som sedan belastas med en tryckande kraft vinkelrätt mot skåran tills brott uppstår. Den maximala spänningen som verkar vid brottet beräknas med en enkel ekvation och används som mått för låskulans hållfasthet. Provmetoden är lämplig då den går att utföra med befintlig utrustning på företaget, den provar materialet i färdigtillverkade låskulor samt i samma område som de maximala spänningarna i en låskula belastad i en snabbkoppling uppstår. NBT nyttjar även dragspänningar vilket är fördelaktigt när sprödhet ska upptäckas i ett material. För att fastställa hur olika materialegenskaper samt geometrier för provkroppen påverkar provresultaten utförs en djupare analys av provmetoden. Analysen ger även vilka geometrier som bör användas vid utförandet av NBT samt värdet för den konstant som används vid beräkning av brottspänningen. Praktiska prov av NBT utförs inte i detta arbete men rapporten innefattar slutsatser om provmetoden och rekommendationer till företaget hur ett fortsatt arbete med NBT kan utföras. / A company that manufactures hydraulic quick-couplings has discovered through regular quality checks that the quality of some of the locking balls for the locking mechanism in the quick couplings suddenly has become insufficient and the locking balls rupture under load. The locking balls are made of stainless steel and if they rupture during usage the consequences can be material damage or even personal injury. The company wants to prevent any quality problems and must therefore ensure that the strength of the locking balls is sufficient. The locking balls are purchased from a subcontractor and the company would therefore like to develop a method for strength testing locking balls delivered to the factory. This thesis aims to help the company in developing such a method.  A first step is to investigate the cause of the locking balls rupture. Material analyses are executed by a material laboratory in order to determine what features in the material that causes the ruptures. The analyses shows that rupture is probably caused by an increased brittleness in the material and the brittleness is a consequence of less tempered martensite and a high amount of carbides. With the cause of rupture determined, existing methods for testing material properties is studied. It is important that strength testing is carried out with test specimens prepared from the actual locking balls. Otherwise the influence of the locking balls manufacturing process on the material properties is not taking into account. Many of the standardized methods for testing material properties, however, are hard to apply to the locking balls due to the geometry and small dimensions of the locking balls. A kind of impact test and compression test is performed. One of the purposes with the tests is to investigate if they are adequate for strength testing the locking balls. The results of the tests, however, are not suitable for comparison. Also, a fatigue test of the locking balls is performed by a repetitive loading of a quick coupling. The fatigue test is, however, time consuming and there are uncertainties in the test results. None of these tests is considered suitable as a strength testing method. In this thesis, two recently developed methods for strength testing ceramic balls and the possibility to apply these methods on the locking balls is studied. The study includes an analysis of the stress distribution in a locking ball under load to determine in which region the highest stresses occur. The study provides that only one of the methods is suitable for the locking balls due to differences in preparing the test specimen and which region of the locking ball that is tested in each method. The strength testing method that is proposed in this thesis is called the notched ball test (NBT). In NBT a long and narrow notch is cut in a locking ball which is then loaded in compression perpendicular to the notch until rupture occurs. The maximum stress acting at the rupture is calculated and used to determine the strength of the locking ball. NBT is suitable because it can be performed with existing equipment at the company, the test specimen is prepared from actual locking balls and the test uses tensile stresses which is an advantage when brittleness is to be detected in a material. An analysis of NBT is performed to determine how material properties and different notch geometries is affecting the test results. The analysis also gives some recommendations for notch geometries that should be used when performing NBT as well as a constant that is used when calculating the maximum stress. Practical experiments of NBT are not carried out in this thesis. Instead, conclusions regarding NBT and recommendations for the company on how they should proceed with NBT are given.

Since the 1980s, intercultural dialogue has become increasingly recognized as a way to reduce prejudice, improve relationships, increase intercultural understanding, manage diversity, and contribute to democratic processes. Similarly, civic engagement has emerged as a key priority of municipalities to effectively serve and meet the needs of a culturally diverse public. I conducted an exploratory qualitative research study using focus groups with 13 ethnocultural community leaders in Edmonton, Alberta. The main goals were to understand from their lived experiences and perspectives how intercultural dialogue could contribute to meaningful and culturally appropriate civic engagement for ethnocultural communities. The findings indicated that ethnocultural community leaders are passionate about and committed to improving the lives of their communities, identify strongly with Canada and Edmonton as their home, and appreciate being meaningfully involved in civic affairs. The findings indicated that intercultural dialogue is meaningful if it takes place in a larger framework of civic engagement practices. This framework of meaningful practices is presented along with recommendations that can be adapted and implemented by municipalities, institutions, and organizations that wish to engage meaningfully with and respond effectively to diverse ethnocultural communities.