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The automotive industry, has been innovating in the field of materials development in order to meet the demand for lower emissions, improved passenger safety and performance. Despite various attempts of introducing other lightweight materials (Al, Mg or polymers) in car manufacturing, steel has remained as the material of choice till date due to its excellent adaptability to systematic upgradation and optimization in its design and processing. One of the outcomes is the development of second generation high Mn TWin Induced Plasticity (TWIP) steels with excellent strength-ductility balance suitable for automotive applications. Cost effective high performance TWIP steel design is mostly based on its alloy design and advanced up and down stream processing methods (thermomechanical controlled processing (TMCP)) which can help achieve suitable microstructure to meet the property requirements. It has been observed that grain boundary migration (GBM) in austenite during high temperature TMCP stage dictates grain growth to control the final microstructure. This research work initially investigates the grain growth in Fe-30%Mn steel within a temperature regime of 1000-1200°C. Compared to conventional low Mn steel, austenite boundary mobility in Fe-30%Mn was found to be 1-2 orders of magnitude smaller. Atom probe tomography results showed no Mn segregation at austenite high angle grain boundaries (γ-HAGB) which rules out the effect of Mn solute drag on growth kinetics in Fe-30%Mn steels. Grain boundary character distribution (GBCD) study showed that the sample consists of two different population of grain boundaries. 50% of the grain boundaries are random HAGBs with high mobility. Remaining 50% are special in nature which introduce low mobility boundary/boundary segments in the global boundary network. The special boundaries are mostly in the form of Σ3 CSL boundaries or its variants like Σ9, Σ 27. These boundary/ boundary segments were introduced by the formation of annealing twins and their interactions with the random HAGBs. An attempt to investigate the effect of Mn on growth kinetics at 1200°C showed that Mn slows down growth kinetics up to 15 wt% predominantly by the formation of annealing twins. A qualitative study of the microstructures showed that as Mn concentration is increased from 1% to 15%, the annealing twin density increases resulting in Σ3 frequency to be 30%. The increased twinning frequency is attributed to the effect of Mn on lowering the stacking fault energy (SFE). Annealing twins, belonging to Σ3 CSL family, intersect the HAGBs resulting into twin induced boundary segments which possess very low mobility. In the light of this idea, slow grain growth in high Mn steel was attributed to the population of low mobility boundaries. The proposed ‘twin inhibited grain growth’ model clearly points to the low mobility boundary/boundary segments to be the rate controlling factor during grain growth in high Mn steels. The effect of carbon on grain growth in Fe-30%Mn steel showed that the presence of carbon makes the growth kinetics faster by a factor of 4 and 6 at 1200°C and 1100°C respectively. Although, atom probe tomography results indicated that in presence of carbon, Mn segregation takes place at γ-HAGBs in Fe-30%Mn steel, solute drag does not appear to play a role as it was seen that with increase in Mn content beyond 1%, the solute effect of Mn in slowing down HAGB migration becomes weak. Also, abovementioned higher mobility values are obtained from the growth kinetics of Fe-30Mn-0.5C. This once again highlights the fact that effect of Mn in slowing down grain growth is due to the low mobility of twin/twin related boundaries or boundary segments. Controlling grain growth has been commonly proposed to be accomplished through small addition (<0.1%) of microalloying elements (Nb, V and Ti) which can slow down GBM at high temperature by solute drag and at low temperature by precipitate pinning (Zener drag). This research work has also experimentally quantified the solute drag of Nb in a series of Fe- 30%Mn steels. Grain boundary mobility was estimated for various temperatures and niobium contents. An attempt was made to calculate the grain boundary mobility in presence of niobium using Cahn’s solute drag model. This calculated mobility, when used in the proposed ‘twin inhibited grain growth’ model, the predicted growth kinetics which showed very good fit with the experimentally obtained growth kinetics in case of Fe-30Mn-0.03Nb and Fe-30Mn-0.05Nb steels at 1100°C. The effect of Nb solute drag, thus captured using Cahn’s model, was shown to be slowing down only the HAGB migration in the microstructure, whilst the special boundary mobility was not affected by solute Nb. Another attempt was made through grain boundary engineering (GBE) to control grain growth in Fe-30Mn-0.5C steel. Using different TMCP schemes, GBCD was modified to produce maximum frequency of special boundary. Preliminary studies on grain growth of single step-grain boundary engineered samples did show a significant lowering of grain size compared to a no-GBE sample after grain growth. However, the effect of iterative GBE didn’t show any significant effect in controlling grain growth in spite of the fact that it increased Σ3 frequency to 64%. This probably indicates that the effect of GBE on grain growth by the formation of annealing twins/special low mobility boundaries is a complicated process which might involve twin/special boundary morphology, annihilation kinetics and formation of grain clusters in the microstructure other than the formation of immobile special triple junctions through the intersection of twins/special boundaries with the random HAGBs. / Thesis / Doctor of Philosophy (PhD)

Border delineations and walls have been used to protect cities and towns throughout history. In the present age of modern surveillance and advanced military technology however, physical walls have much less significance for the protection of present-day states and nations and have become artifacts of mostly symbolic significance. In an increasingly connected world with the potential for becoming more compassionate, the symbolic significance of the border wall, barrier, and delineation demands to be reassessed and reapproached. This opens the possibility of designing a new binational border typology with functions of business, tourism, cultural education, hospitality, and public assembly that can mutually benefit bordering regions. The site of this thesis is the 1949 Armistice Agreement, or Green Line, on the perimeter of the West Bank of Palestine – a prolonged border conflict of our time and a powerful example of spatial injustice. Through a combination of ancient and modern materials, this thesis explores the potential of hospitality through the design of a roadside inn to recognize the history of its place and create a physical and symbolic bridge for future cooperation. In addition to lodging for travelers, the program incorporates a museum, artist workshops, dining areas, gift shops, and gathering spaces. Straddling the Green Line along the Dead Sea shoreline, it is designed to carry the memory of the land, but also to symbolize a future that joins divided communities. / Master of Architecture / This thesis looks at the problem of border delineations and walls within a modern context and proposes the use of borders for functions supplementary to border control and security – such as local commerce, cultural spaces, tourism, hospitality, and public gathering places. Border delineations and walls have been used to protect cities and towns throughout history. In the present age of modern surveillance and advanced military technology however, physical walls have much less significance for the protection of present-day states and nations and have become artifacts of mostly symbolic significance. In an increasingly connected world with the potential for becoming more compassionate, the symbolic significance of the border wall, barrier, and delineation demands to be reassessed and reapproached. This opens the possibility of designing a new binational border typology with functions of business, tourism, cultural education, hospitality, and public assembly that can mutually benefit bordering regions. Spatial justice involves the fair and equitable distribution within a space of resources and opportunities. The site of this thesis is the 1949 Armistice Agreement, or Green Line, on the perimeter of the West Bank of Palestine – a prolonged border conflict of our time and a powerful example of spatial injustice. Through a combination of ancient and modern materials, this thesis explores the potential of hospitality through the design of a roadside inn to recognize the history of its place and create a physical and symbolic bridge for future cooperation. In addition to lodging for travelers, the project's program, or scope of work, includes a museum, artist workshops, dining areas, gift shops, and gathering spaces. Straddling the Green Line along the Dead Sea shoreline, it is designed to carry the memory of the land, but also to symbolize a future that joins divided communities.

Text in Afrikaans / The earlier conceptualisation of the roles of fathers that only focused on the breadwinner, has been replaced by a number of unique roles that are fulfilled by the father. The different aspects of fatherhood have a reciprocal influence on each other and can influence the father’s experience. The goal of this qualitative study was to explore the father’s experience of twins in their middle childhood. Semi-structured interviews were conducted with eight fathers. From this study it became clear that fatherhood of twins can generally be seen as a positive experience, but fathers of twins face extra challenges that lack in the case of single children. The researcher came to the conclusion that by being aware of the changes in each developmental stage, the father can prepare himself better for fatherhood and handle situations that he experiences at a particular moment. Various suggestions that can be useful for parental guidance and preparing fathers of twins for fatherhood were made. / Social Work / M. Diac. (Play Therapy)

Ye, Maoliang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 32-36). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.ii / ACKNOWLEDGEMENT --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Literature Review --- p.5 / Chapter 2.1 --- Measurement of Happiness and Its Reliability --- p.5 / Chapter 2.2 --- Income and Happiness: Hypotheses --- p.8 / Chapter 2.3 --- Literature Review on MZ twins approach --- p.12 / Chapter 3 --- Methods --- p.15 / Chapter 3.1 --- Omitted Variable Bias (Selection Effect) --- p.15 / Chapter 3.1.1 --- Ordinary Least Squares (OLS) Model --- p.15 / Chapter 3.1.2 --- Fixed-Effect (FE) Model --- p.16 / Chapter 3.2 --- Measurement Error --- p.17 / Chapter 4 --- Data --- p.19 / Chapter 5 --- Results --- p.21 / Chapter 5.1 --- Does Income Matter? --- p.21 / Chapter 5.1.1 --- OLS Regressions Using the Whole Sample --- p.21 / Chapter 5.1.2 --- Within-twin-pair Fixed-effect Estimations --- p.23 / Chapter 5.2 --- Sensitivity Analysis --- p.24 / Chapter 5.2.1 --- Other Indicators of Wealth --- p.24 / Chapter 5.2.2 --- Wage or Wage Rate? --- p.25 / Chapter 5.2.3 --- Measurement Error --- p.25 / Chapter 5.2.3.1 --- Does Education Matter? --- p.25 / Chapter 5.2.3.2 --- Reexamine the Income Effect --- p.27 / Chapter 5.3 --- Men vs Women --- p.29 / Chapter 5.4 --- Within Marriage: Income Pooling or Relative Economic Status? --- p.30 / Chapter 6 --- Conclusions --- p.31 / Chapter 7 --- Bibliography --- p.32 / Table 1: Descriptive Statistics of the Twins --- p.37 / Table 2: OLS Estimates of Happiness Using All Twins --- p.38 / Table 3: Ordered Probit Estimates of Happiness Using All Twins --- p.39 / Table 4: Within-twin-pair Fixed Effect Estimates of Happiness Using MZ Twins --- p.40 / Table 5: Within-twin-pair Fixed Effects Estimates of Happiness Using MZ Twins: Other Indexes --- p.41 / Table 6: Within-twin-pair Fixed Effects Estimates of Happiness Using MZ Twins: Using Wage Rate --- p.42 / Table 7a： Correlation Matrices of Different Measurements on Education --- p.43 / Table 7b： Correlation Matrices of Different Measurements on Income --- p.43 / Table 8: Estimates of The Effect of Education on Happiness: Considering Measurement Error --- p.44 / Table 9: Reexamine the Effect of Income on Happiness: Considering Measurement Error --- p.45 / Table 10: OLS Estimates of Happiness Using Female and Male Twins --- p.46 / Table 11: Within-twin-pair Fixed Effect Estimates of Happiness Using Male MZ Twins --- p.47 / Table 12: Within-twin-pair Fixed Effect Estimates of Happiness Using Female MZ Twins --- p.48 / Table 13: Within-twin-pair Fixed Effect Estimates of Happiness Using Married MZ Twins --- p.49 / Table 14: Within-twin-pair Fixed Effect Estimates of Happiness Using Married Male MZ Twins --- p.50 / Table 15: Within-twin-pair Fixed Effect Estimates of Happiness Using Married Female MZ Twins --- p.51

Text in Afrikaans / The earlier conceptualisation of the roles of fathers that only focused on the breadwinner, has been replaced by a number of unique roles that are fulfilled by the father. The different aspects of fatherhood have a reciprocal influence on each other and can influence the father’s experience. The goal of this qualitative study was to explore the father’s experience of twins in their middle childhood. Semi-structured interviews were conducted with eight fathers. From this study it became clear that fatherhood of twins can generally be seen as a positive experience, but fathers of twins face extra challenges that lack in the case of single children. The researcher came to the conclusion that by being aware of the changes in each developmental stage, the father can prepare himself better for fatherhood and handle situations that he experiences at a particular moment. Various suggestions that can be useful for parental guidance and preparing fathers of twins for fatherhood were made. / Social Work / M. Diac. (Play Therapy)

This essay examines the Proto-Indo-European motif of the Divine Twins, as it has been interpreted in Scandinavia during the Bronze and Iron Ages. Because of the difference in opinion between archaeological researchers regarding when the Divine Twins disappeared, an examination of the material culture that has been connected to this motif is undertaken. Duality as a concept is used to discuss the relationship of mythological twins to, on one hand, likeness and closeness, and, on the other, opposing personalities, contrasting aspects and animosity. Based on the analysis of the Scandinavian material culture, it is concluded that the Divine Twins as a motif survived the debated Bronze Age collapse. Furthermore, the inclusion of Nordic ethnographic accounts from the 19th and 20th century may imply that the Divine Twins survived, at least in popular beliefs, well into the 1900s.

Zhan Siyan. / "November 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 133-152) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

The topic of cleft lip and/or palate is widely researched in literature. However no research to date has focused on mothers' experiences raising twins when one twin is born with a cleft lip and/or palate. This qualitative study aims to explore the unigue experiences of these mothers. The epistemological foundations of this study are postmodern, social constructionist and systemic. In accordance with a gualitative methodology data was collected in the form of the participants' personal written stories. This was done from a post-modern paradigm, from a systemic perspective. Themes that were extracted from the stories according to thematic content analysis, not only reflect the experiences of mothers raising twins when one twin is born with a cleft lip and/or palate, they also provide an in-depth understanding of these mothers' experiences and unique situations. Recommendations for future research are offered. / Psychology / M.A. (Clinical Psychology)

Investigations on post service material showed that Alloy 800H pigtails from methanol producer Methanex have service lives ranging from 3 to 18 years. Because of this variability in service life, Alloy 800H creep performance was assessed and a new criterion for its procurement developed. The current criterion recommends an ASTM grain size of 5 (72µm) or coarser with no consideration given to grain size distribution, grain boundary types, or grain boundary network topology. Results from the investigation showed that this current criterion may produce variations in steady state creep rates of an order of magnitude between ASTM grain size 1 and 5, and a 2.5 times variation in creep ductility. The ability to accurately reveal grain boundaries and assess grain boundary types is fundamental to the identification and quantification of coherent twin boundaries, and the measurement of average grain size and grain size distribution. EBSD mapping has the ability to distinguish grain boundary types using crystal orientation measurement. Grain size measurement from optical micrographs relies on morphological indicators to identify coherent twins. However, it is shown that many of the boundaries observed as straight line morphology on 2D sections did not possess {111} (coherent) interfaces. 3D reconstructions of Alloy 800H revealed the deficiencies in classifying geometry from two-dimensional (2D) sections. Σ3 Crystal volumes can be categorized as lamellar or edge structures. Lamellar structures are characterized by the appearance of parallel Σ3 boundary planes while an edge structure contains a single Σ3 interface. Sectioning plane location alters the perception of morphology. For simple twin structures, the tradition 2D classifications of morphology (complete parallel, incomplete parallel and corner Σ3) may all appear on a section plane from a single lamellar structure.