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Advanced high strength steels (AHSSs) are considered to have a promising future due to the outstanding properties compared with the conventional steel and have been widely adopted as the base materials for the automotive components. Some of the challenges preventing the extensive applications of AHSSs are due the solidification defects, i.e. hot tearing and segregation. In this thesis, a 3D mesoscale and multi-physics model is developed and validated to directly investigate solidification defects for semi-solid steel with dendritic morphology associated with the peritectic transformation. Similar to the prior models [1,2], the current model explicitly considers the solidification behavior of each grain prior to assembling, which allows for the mesoscale simulation within a semisolid containing thousands of grains. Six sub-models are incorporated: (i) microstructure generation model is used to create the fully solidified microstructure of equiaxed grains based on a Voronoi tessellation; (ii) a dendritic solidification module based on an average volume approach is developed for predicting the solidification behavior of a random set of grains, considering the diffusion in different phases along with peritectic transformation. The progressive coalescence to form a solid cluster is predicted by incorporating an interfacial energy determination model; (iii) a fluid flow module is developed for the prediction of both intra-dendritic flow and extra-dendritic flow within the dendritic network induced by solidification shrinkage and deformation; (iv) a semisolid deformation model is used and extended to simulate the semi-solid mechanical behavior of steel using a discrete element method. The solid grains are modeled using a constitutive law and implemented via Abaqus commercial software; (v) a coupled cracking model incorporated with a failure criterion is used and extended to predict the crack formation and propagation in semi-solid steel. This comprehensive model consists of models (i-iv) and considers the interaction between the deformation within the solid phase and pressure drop in the liquid phase; (vi) a one-way coupled solute transportation module is also developed and used to simulate the solute redistribution due to fluid flow and diffusion within the liquid channels assuming the solid grains are fixed. The movement of the solute-enriched liquid in the solute transport model is induced by solidification shrinkage and deformation. The new 3D mesoscale model is then applied to correlate the semisolid behavior during solidification to different physical and process parameters. The results from the dendritic solidification model show the evolution in semi-solid microstructure and consequently liquid film migration. The model is able to predict the solidification of equiaxed grains with either globular and dendritic structure having experiencing primary solidification and the peritectic transformation. The coalescence phenomenon between grains is considered at the end of solidification using Bulatov’s approach[24] for estimating interfacial energy. It is seen that only 0.9% of the grains are attractive based on their orientations within a specific domain, significantly depressing final-stage solidification. The dendritic fluid flow model quantitatively captures both semi-solid morphology and the fluid flow behavior, and provides an alternative to the convectional experiment for the prediction of permeability by using the given surface area concentration. Comparison of the numerical and experimental permeabilities shows a good agreement (within ± 5%) for either extra-dendrite or intra-dendritic flow, and deviation from the conventional Carman-Kozeny equations using simplified Dendritic Sv or Globular Sv are explained in detail. The results quantitatively demonstrate the effect of grain size and microstructure morphology during solidification on the permeability prediction. The localization of liquid feeding under the pressure gradient is also reproduced. Additionally, the fluid flow due to shrinkage and deformation for non-peritectic and peritectic steel grades with dendritic morphology during solidification was captured for the first time. The cracking model allows for the prediction of hot tearing initiation and the progressive propagation during a tensile test deformation and the results are compared with the experimental results conducted by Seol et al.[3]at different solid fractions. Parametric studies of coalescence criteria and surface tension on the constitutive behavior of the semisolid are discussed and the deformation behavior of alloys with different carbon contents under a feedable mushy zone is investigated. Finally, the solute transport model has been applied to the continuous casting process of steel for the investigation of centreline segregation, and results indicate that the grain size has a great impact on the solute distribution and solute partitioning combined with intra-dendritic fluid flow leads eventually to liquid channels enriched with solute. The predicted composition in these discrete liquid channels shows a great match with the experimental measured profile obtained via the microscopic X-Ray fluorescence (MXRF). / Thesis / Doctor of Philosophy (PhD)

Syftet med den här undersökningen har varit att utgå från Skolinspektionens tillsynsrapport över Malmö kommun från 2011 och bredda den bilden genom att intervjua de som direkt berörs av skolan, nämligen eleverna. Skolinspektionens rapport har visat att resultat och måluppfyllelse sjunker i vissa delar av kommunen samtidigt som skillnader mellan skolor och olika områden inom kommunen ökar. Jag har intervjuat fem elever för den här undersökningen som alla går i samma klass i ett område som beskrivs som socio-ekonomiskt svagt och där skolresultaten försämrats. Syftet har vidare varit att öka förståelsen kring hur ett mindre antal elever upplever att det är gå på en mångkulturell skola och hur de upplever bemötandet från lärare. Min undersökning har visat att lärarnas bemötande gentemot elever ibland bygger på förutbestämda förväntningar som grundar sig på elevers tidigare resultat. Skolinspektionens tillsynsrapport redogör för att elevinflytande är ett område som ska prioriteras. Undersökningen har dock visat att de tillfrågade eleverna inte upplever det som att de har ett nämnvärt inflytande i skolan och att de upplever undervisningen som förhållandevis enformig. Trots detta efterfrågar eleverna inte nödvändigtvis mer inflytande.

Stockholm is a vibrant and attractive city. Surveys show that the residents in Stockholm are happy with their lives. It has also been proved that Stockholm is a highly socio-economic segregated city.Suburbs that are well known as segregated precarious residential areas in Stockholm, are Botkyrka, Tensta, Husby, Skärholmen, Rinkeby, and others. These suburbs were built during the 1960s-1970s as a part of Sweden’s Million Programme housing. Most of the residents are immigrants, and these areas are stigmatized as dangerous locations, it has been proved that non-European migrants face higher segregation than the European ones. These peripheries have mutual characteristics: they suffer from segregation, bad reputation, stigmatization, criminality, mistrust, and a high unemployment rate.Unfortunately when immigrant women; who used to live under patriarchal-male dominant oppressing societies, moved to democratic multicultural societies, found themselves in a stage of transition.

Uppsatsen syftar till att undersöka den mediala diskursen om miljonprogramsområdet Tensta, med ett särskilt fokus på vilka problem och möjligheter som förknippas med stadsdelen och dess utveckling. Uppsatsen syftar även till att undersöka medvetenheten om Tenstas kulturhistoriska värden i diskursen om stadsdelen. En kritisk diskursanalys utförs för att undersöka hur Tensta, kopplat till segregation, skildras. Studien visar att det finns tydliga och dominerande diskurser kring segregation, utanförskap och ojämlikhet som präglar skildringen av Tensta som stadsdel. Studien visar även att det i de enskilda artiklarna även finns andra diskurser. Till exempel företagande, utbildning samt politiska diskurser (liberal och vänster) vilka används för att lyfta fram lösningar för segregation och utanförskap samt för att kritisera politiska motståndare. Tensta är en välbevarad stadsdel som uttrycker miljonprogrammets tidsanda och som är viktig att värna. Stora delar av Tenstas bebyggelse har som helhet ett stort byggnadshistoriskt värde och är kulturhistoriskt värdefullt. Av analysen så framkommer det inga konkreta förslag på stora ombyggnationer eller rivningar av bostadsbeståndet i Tensta. I diskurserna framkommer det inte något kring de kvaliteter och egenskaper som finns i Tenstas bebyggelse. Inga kulturvärden i stadsmiljön lyfts fram som något problematiskt för stadsdelens utveckling. Dock finns det röster som menar att miljonprogrammets bebyggelsestruktur idag inte bör ses som eftersträvansvärd. Det finns utmaningar vad gäller miljonprogrammets bebyggelse eftersom vi saknar distans till deras tillkomst och inte kan värdera det på sina egna villkor. Kan de dominerande diskurserna om segregation och utanförskap samt det negativa sättet att beskriva Tensta i media komma att påverka stadsdelens utveckling?

Many of the municipalities in Sweden experience socioeconomic residential segregation which increase the polarization between high- and low-income groups and contributes to a higher degree of inequality between people. Previous studies on neighbourhood effects have mainly examined on a city district level and some of them show that different factors such as health, education, participation in politics and trust in society varies depending on where you live. However, there are fewer studies investigating the segregation on a municipality level which this study does for the purpose of getting an overview of the residential segregation in Sweden. By using inequality index as a measure of socioeconomic segregation this study examines how different variables of causes and social and political consequences may correlate with the segregation. To find out if there is a connection between the inequality index and the variables supposed to be causes and consequences of segregation a regression analysis and a correlation analysis is used. The results are showing that small as well as large municipalities are experiencing a residential segregation and the weight of structures on a higher degree of socioeconomic residential segregation. There is also a correlation between the segregation and several negative outcomes on social and political variables. Based on the results, a conclusion can be drawn that the segregation not only contributes to injustice among individuals but also between the municipalities since some of them seem to possess more numerous of problems than others regarding the living environment.

Objectives: As social determinants of health, mortgage possessions (primarily foreclosures in the US context) and housing instability have been associated with certain mental and physical health outcomes at the individual level. However, individual risks of foreclosure and of poor health are spatially patterned. The objective of this study is to examine the extent to which area-specific social and economic characteristics help explain the relationship between mortgage possessions and obesity prevalence in 75 of the 100 most populous US metropolitan areas. Study design: This is a cross-sectional study. Methods: The study relies on three sources of data: the Selected Metropolitan/Micropolitan Area Risk Trends (SMART) project, RealtyTrac foreclosure data, and the American Community Survey. Focal social and economic characteristics include foreclosure rates, levels of racial residential segregation, and poverty. Obesity prevalence and several control measures for each metropolitan area are also used. Ordinary least squares regression, weighted using the SMART project data, is used, and statistical significance is set at 0.05. Results: The results suggest that mortgage possessions are independently associated with higher obesity prevalence and that foreclosures operate through the specific channel of racial residential segregation and its tie to the racial composition of a metropolitan area. Socio-economic status of an area, and not poverty, is related to foreclosures and obesity prevalence. Conclusion: Mortgage possessions not only are socio-economic but also have negative health consequences, such as obesity. The findings provide an empirical base for other researchers to uncover the relationships between segregation, mortgage possessions, and obesity at the individual level of analysis. The public health community should be engaged in addressing the issue of foreclosures in the US because the failure to engage may have broad financial and health consequences across large cities.

This is a qualitative study of the perceptions of a purposeful sample of 27 individuals who were students, teachers, or administrators in North Carolina Negro high schools in the period from 1934 to 1966. I interviewed all of them personally or by telephone. All interviews were tape recorded, and the tapes were later transcribed by an individual who was familiar with the speech patterns of the interviewees. A commercial software program was used to help me identify any themes that emerged from the interviews. One main theme was that the conditions of buildings and equipment varied with the particular high school and the time period. Participants’ comments indicated that facilities were substandard because they were old, had not been maintained adequately, or lacked indoor plumbing. A second theme was that students said they had taken a wide range of courses in their senior years, including English, history, mathematics (algebra and trigonometry), science (biology, chemistry and physics), foreign languages (French and Spanish), home economics, and several secretarial or business courses. Responses were mixed about how well the students were prepared for employment, but several students said they were well prepared for college. A third theme was that former students indicated that their parents, teachers, and administrators had worked together effectively to offer supportive environments for students. The fourth theme was that, although the quality of education for black students in general had improved after desegregation began, in some cases desegregation had caused problems for academically talented black students who aspired to go to college. Some expressed the opinion that their teachers had cared more about them than is now the case. A fifth theme was that, although several of the former students said they favored maintaining desegregated public schools, some of them also expressed the hope that more schools attended by blacks would become neighborhood schools. It was the consensus that the federal government was the cause of desegregating Negro high schools altogether. There was a lack of consensus about whether the overall situation of black students had improved or worsened as a result of desegregation.

Segregation, or non-uniformity, in Hot Mix Asphalt (HMA) induces accelerated pavement distress(es) that can reduce a pavement's service life up to 50%. Quality Assurance procedures should detect and quantify the presence of this problem in newly constructed pavements. Current practices are usually based on visual inspections that identify non-uniform surface texture areas. An automatic process that reduces subjectivity would improve the quality-assurance procedures of HMA pavements. Virginia has undertaken a focused research effort to improve the uniformity of hot-mix asphalt (HMA) pavements. A method using a dynamic (laser-based) surface macrotexture instrument showed great promise, but it revealed that it may actually miss significant segregated areas because they only measure very thin longitudinal lines. The main objective of this research is to develop a non-contact system for the detection of segregated HMA areas and for the identification of the locations of these areas along a road for HMA quality assurance purposes. The developed system uses relatively low cost components and innovative image processing and analysis software. It computes the gray level co-occurrence matrix (GLCM) of images of newly constructed pavements to find various parameters that are commonly used in visual texture analysis. Using principal component analysis to integrate multivariable data into a single classifier, Hotelling's T2 statistic, the system then creates a list of the location of possible nonuniformities that require closer inspection. Field evaluations of the system at the Virginia Smart Road proved that it is capable of discriminating between different pavement surfaces. Verification of the system was conducted through a series of field tests to evaluate the uniformity of newly constructed pavements. A total of 18 continuous road segments of recently paved roads were tested and analyzed with the system. Tables and plots to be used by inspection personnel in the field were developed. The results of these field tests confirmed the capability of the system to detect potential nonuniformities of recently completed pavements. The system proved its potential as a useful tool in the final inspection process. / Ph. D.

Den här studien bygger på intervjuer med sju förskollärare från två olika förskolor som ligger i en kommun i Skåne. Syftet med arbetet är att få en inblick i hur förskollärarna arbetar med språkutveckling i en mångkulturell förskola där så gott som samtliga barn har ett annat modersmål än svenska och en förskola där hälften av barnen har annat modersmål än svenska. Vårt syfte var att se likheter och skillnader i arbetssätt med språkutveckling mellan de båda förskolorna.Resultatet visar att båda förskolorna arbetar mycket med språkutveckling. Den mångkulturella förskolan har dock svårt att kommunicera och ha ett bra samarbete med föräldrarna vilket leder till att språkutvecklingen blir lidande. Den andra förskolans starka sidor är att barnen som inte kan språket lär sig svenska snabbare då barnet blir omgivet av svenska språket både av personal och av barnen på förskolan.