A blankholder is used to hold the edges of metal sheet while it is being formed by a matrix and a punch. An efficient way to design a stamping die is to integrate the blankholder plate into the die structure. This would eliminate the time and cost to manufacture blankholder plates. The integrated structure is called integrated blankholder. The main focus of this thesis is structural analysis and optimization of the integrated blankholder. The structural analysis of the integrated blankholder model (used for the production of doors of Volvo car model V70) is performed using Hypermesh and Abaqus. The FE-results were compared with the analytical calculations of the fatigue limit. To increase the stiffness and reduce the stress levels in the integrated blankholder, topology and shape optimization is performed with Optistruct. Thereafter, a CAD model is set up in Catia based on the results of optimization. Finally, structural analysis of this CAD model is performed and the results are compared with the original results. The results show reduction in stress levels by 70% and a more homogeneous stress distribution is obtained. The mass of the die is increased by 17 % and in overall, a stiffer die is obtained. Based on the simulations and results, discussion and conclusions are formulated.

The retrogression-reaging (RRA) and hot forming behavior of AA7075 were studied. AA7075 is a high-strength alloy used in applications where weight is of particular importance, such as in automobiles. Like many of the high-strength aluminum alloys, AA7075 requires elevated temperature forming to achieve ductility comparable to steels at room temperature. Since AA7075 is a precipitation hardening alloy, heat treatments during forming and production need to be closely controlled to limit any loss of strength due to changes in the microstructure. Two new forming concepts are introduced to explore the feasibility of forming AA7075 in manners compatible with current automotive manufacturing processes. They are RRA forming and solution forming. These concepts seek to improve upon the room-temperature formability of AA7075-T6 and incorporate the paint-bake cycle (PBC) into the heat treatment process. The PBC is a mandatory heat treatment used to cure the paint applied to automobiles during production. Currently, the PBC is conducted at 180 °C for 30 minutes. RRA behavior was studied with molten salt bath treatments between 200 and 350 °C. The PBC was used in lieu of the standard 24 hour reaging treatment conducted at 121 °C. It was determined that retrogression treating below 250 °C was acceptable for RRA forming, with retrogressing at 200 °C producing the hardest material after reaging by the PBC. The formability of AA7075-T6 during RRA forming was evaluated by tensile testing at 200 and 225 °C. Ductility of AA7075-T6 at RRA forming temperatures was double compared to those produced at room temperature. RRA forming was demonstrated to achieve this improved ductility and a final material hardness after the PBC of only slightly less than the peak-aged condition. In addition, solution forming behavior was studied at 480 °C. Solution forming can increase ductility compared to RRA forming, but it requires aging at 121 °C prior to the PBC to produce peak-aged hardness. / text

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Chapter 1 of this thesis details the incorporation of a Charged Coupled Device (CCD) detector system with the Durham Imaging Polarimeter. The details include the physical characteristics of the device and the electronics and software associated with the device control and data storage. The introduction of the CCD detector system haa made necessary the inclusion of a super-achromatic half-wave plate in the polarimeter which has an inherent variability in its optic axis. Chapter 2of this work describes fully how suitable corrections for this effect can be made, and derives "first order" results. The CCD performance is examined in comparison with the detector used previously and hence the veracity of the new results is established. Chapter 3 is a relevant summary of the status of the astronomy of the immediate regions of recent star-formation. Chapter 4 describes multicolour polarimetry of NGC2261/R Mon covering the period 1979 to 1986. The data conclusively proves that the polarisation of R Mon must be due to effects close to R Mon (~ 14 astronomical units). This is evident because of the dynamic timescale of the variations of the polarisation of R Mon and the anomalous band of polarisations seen across the head of the nebula. The interpretation presented is an extension of the Elsasser and Staude (1978) method of polarising objects embedded within the confines of a nearly edge-on disk. Detailed polarisations within the main nebula body provide evidence for this extended interpretation and also for an extensive helical magnetic field which may extend into the disk. Also it is seen that R Mon must still be "shrouded" in material preventing light from directly reflecting in the main nebula body. It is not thought that the variations in the region close to R Mon are due to planetary bodies but to accretion from the disk. The results of this re-interpretation of the polarising mechanism are tentatively applied to other similar objects.

The effect of excess gravity on bone-forming elements of the growing perichondrial shaft of embryonic chicks was investigated through the use of the transmission electron microscope and various cytochemical techniques.

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In this thesis I propose an account of knowledge of one's own mental states. My goal is set on a unified transparency account of self-knowledge. It is unified, because the proposal will account for the generation of beliefs about mental states of all types, regardless of whether they are propositional, non-propositional, experiential or non-experiential. My account will thereby be applicable to knowledge of any mental state, from beliefs and desires to fears, hopes, and sensations such as pain. Moreover, it will be a transparency account because it holds on to Gareth Evans's (1982) observation that self-ascribing mental states is done by attending outwards instead of inwards. There is a sense in which we attend to the world when we find out whether we believe something, and my proposal aims to capture this intuition. The core idea I am exploring is the following: generally, when one produces a first-order mental state, one also forms a corresponding, dispositional second-order belief about that state. Both attitudes share elements of their production, which ensures reliability while retaining fallibility. For instance, when you form a belief 'there is a red car' by perceiving a red car, you also generate the dispositional belief 'I believe that there is a red car,' if everything goes right. I argue that almost all features that make self-knowledge special can be explained with this basic idea. The assumption that the production of a first-order mental state and a second-order belief about the state go hand in hand has surprising explanatory power. Moreover, there are at least no obvious reasons why the assumption should be ruled out. The upshot will be a view that we should take seriously as a contender for an explanation of self-knowledge. I will not be able to conclusively show that it is the best explanation, but I argue that it is one worth thinking about. The thesis is structured in three parts. The first part (chapters 1-3) focuses on the phenomenon of self-knowledge and the transparency idea. These chapters serve as the setup for my later proposed view. Chapter 1 and 2 discuss what exactly we want to explain when we say that we aim to explain self-knowledge. I thereby provide an overview of the conceptual landscape of self-knowledge and argue that we should understand the peculiarity of self-knowledge in terms of features of belief and belief-formation. Moreover, I commit myself to the view that the peculiarity has something to do with our cognitive access to mental states and relate that to the goal of a unified account of self-knowledge. Chapter 3 discusses how we ought to understand the other qualification of my goal: a transparency account of self-knowledge. I provide an overview of transparency accounts in the literature and lay out the path to avoid common problems of transparency accounts. In the second part (chapters 4 and 5) I propose the single process model of self-knowledge as a unified, transparency account of self-knowledge. I provide the core principles of the view and show how it explains the features of self-knowledge I aim to explain. Chapter 4 focuses on attitudes, both propositional and non-propositional. Chapter 5 expands the view to phenomenal states, such as being in pain. The third part (chapters 6 and 7) connects the epistemological discussion of the single process model to research on cognition. Chapter 6 proposes a cognitive story of predictive processing that is compatible with the single process model. I thereby discuss the plausibility of the predictive processing idea and its empirical support. I provide a predictive processing story of self-knowledge that fits with the single process model of self-knowledge. In chapter 7 I discuss extended mental states. Clark & Chalmers (1998) propose that at least some mental states, such as beliefs, can be extended to external devices. Given that my aim is a unified account, I ought to say something about knowledge of these extended beliefs. I argue that they cannot be known by the same processes as non-extended mental states because beliefs about extended beliefs show different features than beliefs about our non-extended states that we formed by introspection. Hence, even if my view cannot account for them this is not a problem, because they are not formed by genuine introspection. Instead, we come to know extended mental states by a distinct process that we might call extended introspection. Finally, chapter 8 provides a brief conclusion of the thesis for and points out some placed that require further development. The account is promising as an explanation of self-belief and self-knowledge, but whether it is correct also depends on future research outside the scope of philosophy.

This thesis presents the results of experimental and numerical investigations carried out to assess the effects of tube bending and hydroforming on the crash performance of s-rail structures manufactured from three different advanced high strength steels, namely DDQ, HSLA350, and DP600. The main impetus for this project is to reduce vehicle weight through material substitution and, in order to do so, the effects of material strength on crashworthiness, as well as the interaction between forming processes and crash response must be well understood. To this end, in the current research, s-rails were fabricated through tube bending and hydroforming experiments conducted on DDQ, HSLA350, and DP600 steels with a nominal wall thickness of 1. 8mm, as well as HSLA350 steel with a nominal wall thickness of 1. 5mm. Impact experiments were subsequently performed on non-hydroformed and hydroformed s-rails to examine the effects of the forming processes and material substitution on the crushing loads and levels of absorbed energy. All forming and crash experiments were simulated using numerical finite element methods which provide additional insight into various aspects of the crash response of these structures. In particular, crash simulations were used to show the effects of work-hardening, material thickness changes, and residual stresses incurred during the forming operations. <br /><br /> The numerical tube bending simulations accurately predict the results of the tube bending and hydroforming processes for all materials, particularly for the DP600; the predictions for the DDQ material are the least accurate. Both simulations and experiments show that material thinning occurs on the tensile side of the bend, and material thickening on the compressive side of the bend; the level of thickness change is unaffected by material strength or initial material thickness. The low-pressure hydroforming process does not greatly affect the thickness and strain distributions of s-rails. <br /><br /> The crash simulations provide predictions that are in excellent accord with the measured results, with a maximum error of ±10% in the peak loads and energies; simulations of DP600 s-rails are the most accurate, while simulations of DDQ s-rails are the least accurate. Through simulations and experiments, it is shown that material thickness has the greatest effect on the crash performance of s-rail structures, while material strength plays a secondary role. A 20% increase in the wall thickness of HSLA350 s-rails amounts to a 47% increase in energy absorption. Substituting HSLA350 and DP600 steels in place of DDQ steel leads to increases in energy absorption of 31% and 64%, respectively, for corresponding increases in strength of 30% and 76%. Neglecting material strain-rate effects in the numerical models lowers the predicted peak loads and energies by roughly 15%. By performing a numerical parametric study, it is determined that a weight reduction of 22% is possible by substituting thinner-gauge DP600 s-rails in place of DDQ s-rails while maintaining the energy absorption of the structures.

Streptococcus agalactiae CAMP factor is a protein exotoxin that contains 226 amino acid residues and forms oligomeric pores on susceptible cell membranes and liposomes. In this study, fragments of CAMP factor were created and recombinantly expressed to identify functional domains that are involved in membrane binding, oligomerization, and membrane insertion. Altogether, six truncated forms of CAMP factor were created and assayed. CAMP1-113, CAMP1-170, CAMP57-226, and CAMP171-226 showed different levels of hemolytic activity. CAMP1-56 and CAMP114-226 did not show hemolytic activity or oligomerization ability, but showed binding ability. CAMP114-226 inhibited the hemolytic activity of wild-type CAMP factor, most likely through ‘one-sided’ oligomerization. From the comparison of these fragments, it emerges that the region between residues 57 and 113 plays a crucial role in oligomerization and membrane insertion. The high binding efficiency of CAMP114-226 suggests this region has great responsibility on membrane binding. The hemolytically inactive fragments showed higher binding efficiency than some of the active fragments. For the hemolytic fragments, higher binding efficiency gave stronger hemolysis. These findings support that CAMP factor has different functional regions for pore-formation.