| 11. |
- Hoff Rudhult, Maria
(författare)
-
SIDA VID SIDA? : Svenska företag i biståndsverksamheten, 1946–2013
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis studies how the way private businesses were viewed came to affect their participation, and thus role, in Swedish development aid activities in the 1946-2013 period. The role is here viewed in terms of the relationship between “the public” and “the private”. The relationship between public and private activities, as well as the distinction between them, is mutable, and needs to be understood within the framework of a specific context. This, in turn, means that these relationships between the state, in the form of public activity, and the businesses, in the form of private activity, constitute the more comprehensive research problem of the thesis. The analytical strategy of the thesis is based on a discourse theoretical approach, discursive institutionalism, to study how development aid, based on the ideal of “solidarity”, was formulated, established and upheld as an area of policy, focusing especially on the role that was concurrently created for Swedish private businesses. The application of a genealogical approach in the reading of political texts as well as archival material, reports and evaluations, makes visible how the businesses have been part of the Swedish developmental aid activities during practically the entirety of the time period studied, and that this has not been openly accounted for in the public political material. The study shows that upholding the ideal of the “solidarity-based” politics regarding development aid was enabled by applying different logics of action to different parts of the development aid activity. This is made clear by the political ability to involve businesses in development aid activities without having to expressly renounce the position of solidarity. The result of the thesis also shows that the ideal of “solidarity” influenced both the preconditions for distinctions between public and private, and how views of businesses as illegitimate or legitimate actors in development aid activity changed over time.
|
|
| 12. |
- Jonsson, Kristina, 1967-
(författare)
-
Practices for the Living and the Dead : Medieval and Post-Reformation Burials in Scandinavia
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main themes of the thesis are burial customs and social identities, and how medieval and post-Reformation graves can provide information on such as age structures, phases in life, gender relations and social organization. The study is based on nine groups of Scandinavian material, and it comprises four case studies. The first one deals with social zoning in medieval cemeteries and how age and gender structures varied within and between different social strata. The second concerns ‘atypical’ medieval burials, such as graves in which individuals have been buried in a deviant or peripheral position; and it also focusses on burials of the sick and the impaired. The third case study examines two mainly medieval burial practices: the use of charcoal and burial rods, and possible interpretations of their inclusion in graves. The fourth study deals with post-Reformation burial customs; how they differ from the medieval ones and what notions may have caused the changes in practice. It is concluded that in the Early Middle Ages, social identity was to a large extent intermingled with group identity. Towards the twelfth century, the social boundaries were sharpened and burial customs emphasizing personal aspects such as gender, age and body developed. A person’s biological status was a major factor in determining gender and social identities, and thereby also social status. In the Late Middle Ages the inner burial customs became more homogeneous, probably as a result of new religious beliefs and ecclesiastical restrictions. After the Reformation, social differences in burial prevailed, and above all the memorials displayed and shaped social identities. The inner burial customs became more varied again, displaying a ‘revival’ of old customs. This was most likely caused by changes in religious practices: since the Church no longer provided comforting and protective ritualistic practices they were instead performed before the funeral by the next of kin.
|
|
| 13. |
- Thibblin, Anders, 1980-
(författare)
-
Thermal Barrier Coatings for Diesel Engines
- 2017
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reducing the heat losses in heavy-duty diesel engines is of importance for improving engine efficiency and reducing CO2 emissions. Depositing thermal barrier coatings (TBCs) onto engine components has been demonstrated to have great potential to reduce heat loss from the combustion chamber as well as from exhaust components. The overall aim of this thesis is to evaluate the thermal cycling lifetime and thermal insulation properties of TBCs for the purpose of reducing heat losses and thermal fatigue in heavy-duty diesel engines.In the thermal cycling test inside exhaust manifolds, nanostructured yttria-stabilized zirconia (YSZ) performed best, followed by YSZ with conventional microstructure and then La2Zr2O7. Forsterite and mullite could not withstand the thermal cycling conditions and displayed large cracks or spallation. Two sol-gel composite coatings displayed promising thermal cycling performance results in a furnace test under similar conditions.Thermal cycling testing of YSZ coatings having different types of microstructure, in a furnace at temperatures up to 800°C, indicated that the type of microstructure exerted a great influence. For the atmospheric plasma sprayed coatings, a segmented microstructure resulted in the longest thermal cycling lifetime. An even longer lifetime was seen for a plasma spray–physical vapour deposition (PS-PVD) coating.In situ heat flux measurements inside the combustion chamber indicated that plasma-sprayed Gd2Zr2O7 was the TBC material providing the largest heat flux reduction. This is explained by a combination of low thermal conductivity and high reflectance. The plasma-sprayed YSZ and La2Zr2O7 coatings provided very small heat flux reductions. Long-term testing indicated a running-in behaviour of YSZ and Gd2Zr2O7, with a reduction in heat flux due to the growth of microcracks in YSZ and the growth of macrocracks in Gd2Zr2O7.
|
|
| 14. |
- Xiang, Shengmei, 1991-
(författare)
-
Oxidation, Creep and Fatigue Synergies in Cast Materials for Exhaust Manifolds
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The future development of engines of heavy-duty vehicles towards reduced CO2 emission will increase the exhaust gas temperature and render the exhaust atmosphere more corrosive. The current service material of exhaust gas components - a ferritic ductile cast iron called SiMo51 - will soon meet its upper-temperature limit. Three alternative materials were suggested in a previous study: SiMo1000 (ferritic, nodular cast iron), D5S (austenitic, nodular cast iron), and HK30 (austenitic, cast steel). Together with SiMo51 (reference) the alternative materials are investigated in the present thesis with respect to performance and degradation mechanisms, under the individual or collective influence of high-temperature fatigue, corrosion, and creep.Firstly, fatigue, corrosion and corrosion-fatigue at 800oC were studied to establish their degradation mechanisms and relative performance. The individual influence of fatigue and corrosion was studied using low-cycle fatigue (LCF) tests in argon, and oxidation tests in a synthetic exhaust gas (5%O2-10%CO2-5%H2O-1ppmSO2-N2(bal.)), respectively. The collective influence of fatigue and corrosion was studied using LCF test in the synthetic exhaust gas. The degradation mechanisms were analyzed through extensive characterization of the tested specimens. Different crack-initiation mechanisms were found for the various combinations of materials and atmospheres. In argon, crack initiation was generally caused by secondary phases at the surface (graphite in SiMo51/SiMo1000, graphite and intermetallics in D5S) and near-surface casting defects (in all materials). In the exhaust atmosphere, crack initiation was generally influenced by oxide intrusions (formed from oxidized graphite in SiMo51 and expressed as dendrite boundary corrosion in HK30), internal fracture of intermetallics (in D5S), decarburization creating microcracks/stress concentrations (in SiMo1000), and near-surface casting defects (in all materials). The relative performance was analyzed using fatigue and oxidation curves.Secondly, two improvements were attempted for SiMo1000, a modified casting geometry for improved graphite morphology and a surface treatment method, nitrocarburizing. The first attempt resulted in significantly reduced decarburization, decreased initial crack size formed by graphite/matrix debonding and an improved corrosion-fatigue life of 8 to 16 times. The second attempt resulted in two types of microcracks after the process and a self-sustained growth of the diffusion layer, when subjected to high-temperature corrosion. A strong corrosion-fatigue synergy was found, reducing the fatigue lifetime by 84-89%.Thirdly, the collective influence of fatigue and creep was studied for D5S using regular LCF tests (reference) and creep-fatigue tests, with either tension or compression dwell. Both dwell directions reduce fatigue life but promote different creep-fatigue-corrosion interactions. Tension dwell produces a clear creep-fatigue synergy, generating creep pinholes near graphite nodules. Typically, such damage is observed in regular creep tests of several months. Compression dwell decreases lifetime more than tension dwell due to increased peak tensile stress and a more pronounced surface crack initiation by an oxide wedging mechanism.The investigation in the present study gives a better understanding of the correlation between microstructure and corrosion-fatigue/creep-fatigue properties in materials used for exhaust gas components. Moreover, the combination of fatigue tests in argon/exhaust atmosphere, oxidation tests in the exhaust atmosphere, creep-fatigue tests, and creep tests from a previous study shows how corrosion, fatigue, and creep individually and synergistically affect the material performance at elevated temperature.
|
|
| 15. |
- Zhang, Qing
(författare)
-
Mechanical Properties of Semi-Solid Al Castings : Role of Stirring
- 2022
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Semi-solid metal (SSM) casting has been widely used in automotive industries to reduce the weight. In RheoMetalTM process which is one of the variations of SSM, the slurry fabrication can be finished within 30 second and can the slurry making process can be integrated into a high pressure die casting (HPDC) route without significant adjustments, making the process a promising alternative for industrial application. However, the application of SSM is still limited due to the semi-solid deformation-induced casting defects, such as macrosegregation and large pores. Due to the short stirring duration, the inefficient stirring is the leading cause of defects formation. Another critical issue in the RheoMetalTM process is the oxidation during the stirring process, which results in the increase of oxides in the castings, reducing the mechanical properties.This study aims to investigate the ductility and the fatigue performance of SSM castings. The main focuses were on the role of the stirring and oxides. The quenched slurry was analyzed to evaluate the effect of the stirring on the particle distribution in the slurry, and its effect on the formation of pores and segregation was discussed. To investigate the oxidation during the slurry making process, two alloys with different Mg content were cast. Scanning electron microscopy (JEOL JSM-7001F SEM) equipped with Energy-dispersive X-ray spectroscopy (EDS) was used to identify the oxides on the fracture surface. Tensile test and fatigue test accompanied with direct current potential drop (DCPD) were performed to investigate the ductility and fatigue performance, respectively.The results suggest that the intensive stirring can avoid the formation of the large clusters, making the particle distribution homogeneous in the slurry. The Mg contents determined the types of the oxides formed in the slurry making process. For alloys with sufficient Mg, the oxides would be MgAl2O4, which exist as small films with numerous cracks, while a large oxides film will be formed in the case of low Mg content.The combined influence of porosity and oxides was concluded. In the 42000 alloy, because of the low Mg content, the ductility was dominated by the large oxide films. In contrast, in the Magsimal 59 alloy, the presence of small oxides (less than 0.2 mm in majority) leads to the influence of oxides on the elongation negligible. However, a good correlation was obtained between the largest pores and ductility.The fatigue test shows that the surface liquid segregation (SLS) determined the fatigue strength under cyclic bend loading, due to its higher hardness. The effect of the inner pores on the fatigue performance was negligible, as the maximum stress was applied on the surface.
|
|
| 16. |
- Aman, Robert, 1982-
(författare)
-
Impossible Interculturality? : Education and the Colonial Difference in a Multicultural World
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- An increasing number of educational policies, academic studies, and university courses today propagate ‘interculturality’ as a method for approaching ‘the Other’ and reconciling universal values and cultural specificities. Based on a thorough discussion of Europe’s colonial past and the hierarchies of knowledge that colonialism established, this dissertation interrogates the definitions of intercultural knowledge put forth by EU policy discourse, academic textbooks on interculturality, and students who have completed a university course on the subject. Taking a decolonial approach that makes its central concern the ways in which differences are formed and sustained through references to cultural identities, this study shows that interculturality, as defined in these texts, runs the risk of affirming a singular European outlook on the world, and of elevating this outlook into a universal law. Contrary to its selfproclaimed goal of learning from the Other, interculturality may in fact contribute to the repression of the Other by silencing those who are already muted. The dissertation suggests an alternative definition of interculturality, which is not framed in terms of cultural differences but in terms of colonial difference. This argument is substantiated by an analysis of the Latin American concept of interculturalidad, which derives from the struggles for public and political recognition among indigenous social movements in Bolivia, Ecuador and Peru. By bringing interculturalidad into the picture, with its roots in the particular and with strong reverberations of the historical experience of colonialism, this study explores the possibility of decentring the discourse of interculturality and its Eurocentric outlook. In this way, the dissertation argues that an emancipation from colonial legacies requires that we start seeing interculturality as inter-epistemic rather than simply inter-cultural.
|
|
| 17. |
- Bomark, Niklas, 1984-
(författare)
-
Drawing Lines in the Sand : Organizational Responses to Evaluations in a Swedish University
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As organizations are increasingly evaluated, evaluative practices are becoming central to organization theory. While highlighting how organizations may respond to evaluations, earlier work on organizations and evaluation has been limited to inter-organizational evaluations, such as third-party rankings or ratings. As a consequence, the prevailing perspective on organizational responses has been developed almost entirely based on an idea that what is being evaluated in the first place – the evaluation entities – is unproblematic. Acknowledging that the definition of the evaluation entity may be ambiguous prior to the evaluation, and that this definition might vary over time, some interesting areas of inquiry emerge in relation to current understandings of organizational responses to evaluations.First, it raises questions of how entities are defined in evaluations, and how this can be seen as an organizational response? Second, it raises questions about our current understanding of the dynamics of organizational responses and how organizational responses shape organizational adaptation and change. Third, it raises question about how entity definitions shape how organizations become evaluated. Despite recent interest in understanding organizational responses to evaluations, organizational scholars have largely refrained from entertaining these questions.The objective of this dissertation is to revisit the assumption of the unambiguously defined evaluation entity in the current theorizing on organizational responses to evaluations. An opportunity to investigate this question emerged when the oldest university in Sweden, Uppsala University, decided to carry out two large evaluations of the research activities within the university – in 2007 and in 2011. The evaluation was made public and aimed to identify and evaluate (partly through a rating) the research achievements of the departments of the university. This presented an opportunity to study organizational responses to evaluations in a setting that is different from what has been studied previously. Based on a study of 44 of the departments within the university my main finding show how entities are defined and how this can be seen as an organizational response to evaluations. My findings also show how entity definitions interact with the more traditional responses taken after an evaluation, and that entity definitions shape the evaluation of the department. This dissertation thus lends support for the idea that apart from responding by changing activities or their organizational units, organizations can also respond to evaluations by the way they shape what will be evaluated – the entities being subject for the evaluation. The findings in this dissertation holds consequences for organizational theory and the evaluation of organizations.
|
|
| 18. |
- Freitas de Abreu, Marcio
(författare)
-
Cavitation Erosion Mechanisms in Cast Irons
- 2021
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The research presented in this thesis investigated the mechanisms by which cavitation erosion damage develops in lamellar graphite iron (LGI) and austempered ductile irons (ADIs). This has been achieved by image sequences of surface erosion on test samples in tandem with weight change measurements. Cavitation erosion is caused by the appearance and collapse of bubbles in a liquid which undergoes rapid pressure oscillations. Imploding bubbles release heat, shockwaves and high-speed microjets which may strike nearby solid walls and damage them.The heavy-duty automotive industry encounters this problem in the engine cooling system. The combustion chamber requires precise temperature control for optimal operation and excess heat must be removed by a liquid coolant. In trucks, the coolant liquid achieves this by circulating around the cylinder liner, a hollow cylindrical part that encloses the combustion chamber and prevents its gases from escaping. However, the engine’s intense vibrations create repeated pressure variations in the coolant, and bubbling ensues. With prolonged operation, the cylinder liner’s wet outer wall may be severely worn, resulting in surface roughening, eroded patches and pits. Cavitation is responsible for great losses due to vehicle downtime and maintenance costs. The present work aims, therefore, at analyzing the behavior under cavitation exposure of cast irons that are currently used, or being considered for use, in the cooling system.Cylinder liners are currently made of lamellar graphite iron with a matrix structure consisting of pearlite and a network of steadite, and the analysis for this material has been presented in Paper 1. Austempered ductile irons are candidate materials for pumps and other components of the cooling system due to their very good mechanical properties; three ADIs of increasing hardness, obtained from different heat treatments of a spheroidal graphite iron, have been analyzed in Paper 2. Experiments consisted of an ultrasonic vibratory probe to which material samples were attached and subsequently immersed in a beaker containing engine coolant. The samples were weighed and photographed in an SEM after several predetermined time intervals. This produced a detailed sequence of images which, in combination with mass loss data, can explain the mechanisms by which cavitation damage initiates and develops in these materials. The text of this thesis summarizes the findings presented in the appended articles and compares the behavior of LGI and ADI.
|
|
| 19. |
- Jonsson, Anders, 1967-
(författare)
-
Regulation of Glutamine Synthetase in the Diazotroph Rhodospirillum rubrum
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The bacterial cell needs ammonia for synthesis of glutamine from glutamate. Only one enzyme is able to catalyze this reaction, namely glutamine synthetase (GS). GS can be regulated both transcriptionally and post-translationally and it is present in all kingdoms of life. Our study has been focused on the post-translational regulation of GS in the diazotrophic bacterium Rhodospirillum rubrum. A number of proteins are involved in the covalent regulation of GS, among them are the regulatory PII proteins that depending on growth conditions also like GS are covalently modified. We have purified all proteins involved in GS regulation and developed several in vitro assays with the aim of understanding GS regulation in R. rubrum. Studies on the influence of the small metabolite effectors α-ketoglutarate and glutamine are also included together with the effect of divalent cations. In both R. rubrum and Escherichia coli, one of the enzymes participating in GS regulation is the bifunctional enzyme GlnE. GlnE is responsible for both the attachment and the removal of AMP groups from GS, which basically leads to a more inactive or active enzyme respectively. Apart from examining the above functions of GlnE, we have also found a novel third activity of R. rubrum GlnE, an antioxidant function, which is located in the C-terminal domain. We have examined this novel activity of GlnE in great detail, including site specific mutagenesis. We also generated and analyzed ΔglnE mutants in R. rubrum and the results from these studies show that suppressor mutations can occur within glnA, the gene encoding GS. We assume that the function of these suppressor mutations is to lower the specific activity of GS, which otherwise might be too high in a ΔglnE mutant since they lack the ability to adenylylate GS. In other words, it seems that ΔglnE mutants can not be generated without producing suppressor mutations.
|
|
| 20. |
- Nicol, Christopher, 1980-
(författare)
-
Change in the cage : Exploring an organisaitonal field: Sweden's biofuel region
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This Ph.D. thesis seeks to better understand how change occurs within a group of organisations. Aiming to make a contribution to institutional theory, it brings together three main schools, namely: old, new and neoinstitutionalism, in an integrative approach for understanding organisational field change. The study seeks to examine and explore a community of organisations who have come together to form an organisational field. More specifically, the object is to better understand how an organisational field is formed and developed and how change is driven, at an organisational and organisational field level, as a consequence of this field formation. Moreover, the study investigates the impact of triggers for change upon the field, and the role that institutional forces and individuals play in the process of organisational field change.The theoretical chapters, as discussed, integrate the concepts of change from three schools developing a comprehensive framework of organisational field change with which the empirical material can be analysed, in order to make the theoretical contribution. The empirical work is based on a case study, incorporating two rounds of interviews and secondary data collection, undertaken from 2007 - 2011. The case study examines the development of the Biofuel Region, a collection of organisations based, principally, in Ornskoldsvik, Northern Sweden, that have worked together to develop a public and private biofuel transportation infrastructure. Besides being a fascinating case of regional development and having the reassuring object of creating an eco-efficient fuel the Biofuel Region, regarded as an organisational field, provided good access to respondents and useful insights into the way that fields form and change.The contributions of this thesis offer an insight into the manner with which the formation of an organisational field can begin with a drive for a legitimisation of the field's endeavours.Underscored is how the field can restructure continuously as a consequence of triggers for change, and that consequently fields are dynamic and not static and are thus changing frequently. Furthermore, it highlights that given the correct conditions individuals can play a key role in the management of an organisational field. The overarching contribution is that change occurs in a plethora of different ways within a field as a consequence of its formation,development, triggers for change, individual's contributions and institutional forces.
|
|
