VictorJuiz/thesis huggingface dataset:
Variational models in martensitic phase transformations with applications to steels
Keywords: Bain strain
Nishiyama-Wassermann
Laminates
lattice transformation
fcc-to-bcc
least atomic movement
non-classical interfaces
lath martensite
twinned martensite
Pitsch
tetragonal
Kurdjumov-Sachs
Quasiconvexity
martensite
Relaxation
austenite
Terephthalic Acid
non-linear elasticity
Bravais lattices
orientation relationships
twins within twins
transformation strain
self-accommodation
double shear theories
volume fractions
(557) habit planes
microstructure
austenite martensite interfaces
Greninger-Troiano
steel

This thesis concerns the mathematical modelling of phase transformations with a special emphasis on martensitic phase transformations and their application to the modelling of steels.
In Chapter 1, we develop a framework that determines the optimal transformation strain between any two Bravais lattices and use it to give a rigorous proof of a conjecture by E.C. Bain in 1924 on the optimality of the so-called Bain strain.
In Chapter 2, we review the Ball-James model and related concepts. We present some simplification of existing results.
In Chapter 3, we pose a conjecture for the explicit form of the quasiconvex hull of the three tetragonal wells, known as the three-well problem. We present a new approach to finding inner and outer bounds.
In Chapter 4, we focus on highly compatible, so called self-accommodating, martensitic structures and present new results on their fine properties such as estimates on their minimum complexity and bounds on the relative proportion of each martensitic variant in them.
In Chapter 5, we investigate the contrary situation when self-accommodating microstructures do not exist. We determine, whether in this situation, it is still energetically favourable to nucleate martensite within austenite. By constructing different types of inclusions, we find that the optimal shape of an inclusion is flat and thin which is in agreement with experimental observation.
In Chapter 6, we introduce a mechanism that identifies transformation strains with orientation relationships. This mechanism allows us to develop a simpler, strain-based approach to phase transformation models in steels. One novelty of this approach is the derivation of an explicit dependence of the orientation relationships on the ratio of tetragonality of the product phase.
In Chapter 7, we establish a correspondence between common phenomenological models for steels and the Ball-James model. This correspondence is then used to develop a new theory for the (5 5 7) lath transformation in low-carbon steels. Compared to existing theories, this new approach requires a significantly smaller number of input parameters. Furthermore, it predicts a microstructure morphology which differs from what is conventionally believed.
Improving the outcomes of kidney transplantation from deceased organ donors
Keywords: organ donation
brain death
kidney transplant
hypoxia inducible factor
hypoxia
liver transplant

This thesis sought to improve our understanding of how kidneys become injured as a consequence of organ donation, with the aim of improving the outcomes of transplantation. Every year, hundreds of patients on the waiting list die whilst awaiting a kidney transplant. With an ever-increasing demand for suitable organs, supply cannot keep up with the pressures on the transplant waiting list. As a consequence the transplant community are forced to use organs that previously would not have been considered suitable for transplant, including from older donors with additional comorbidities. This thesis aimed to develop an understanding as to how the kidney becomes injured during the donation process, identifying which key cellular homeostatic processes are disturbed as a consequence of donation.
The thesis outlines the experimental development of rodent models of organ donation replicating the donation process for donation after brain death (DBD) and donation after circulatory death (DCD) donors and also the development of a kidney ischaemia reperfusion injury (IRI) model. Proteomics was subsequently used to identifying global protein alterations in the kidney as a consequence of brain death and ischemia reperfusion injury using bioinformatics tools to identify involvement of cellular pathways. The results indicated alterations in mitochondrial function and metabolic homeostasis occurring following brain death.
Alterations in cellular metabolism and mitochondrial function were then confirmed using metabolomics and mitochondrial functional assays. I subsequently evaluated how alterations in cellular hypoxia and the hypoxia inducible factor system is altered in the brain dead organ donor kidney and aimed to target this system as a means of conditioning the brain dead organ donor to prevent mitochondrial and metabolic mediated injury to kidney cells following brain death. This involved exploring the role of prolyl hydroxylase inhibitors, including dimethyloxalylglycine, on mitochondrial function and whether this could be a therapeutic target in organ donation.
This thesis provides important insights into the mechanism of injury of kidneys following brain death, providing evidence that even before procurement and preservation in the DBD donor alterations in mitochondrial function and metabolic homeostasis occur. I provide preliminary data on the use of prolyl hydroxylase inhibitors in altering mitochondrial function. I also outline my involvement in other ongoing projects in organ donation and machine perfusion that also aim to improve the outcomes of deceased donor kidney and liver transplantation.
Investigation of candidate risk genes for neuropsychiatric disease in vitro and in vivo using ENU mutagenesis
Keywords: mouse
genetics
bipolar disorder
schizophrenia
animal models
neurobehavioral genetics

Schizophrenia is a complex mental disorder characterised by positive symptoms such as hallucinations and psychosis, negative symptoms such as avolition and anhedonia, and cognitive defects. Schizophrenia risk has a genetic component, and it is likely that this is caused by interaction between numerous genes with individually small effects. Environment also plays a role; factors associated with schizophrenia include drug use, prenatal stressors and living environment.
Candidate genes linked to schizophrenia have been identified through recent GWAS of human populations with the disorder, including ANK3, TCF4 and CACNA1C. GWAS associations alone are not sufficient to identify these as definitive risk genes for the disease. In order to validate these findings, animal models (in particular the mouse) can be used to study the effect of mutations in these genes of interest. Knockouts of these genes in the mouse are lethal, so we have used the ENU mutagenesis DNA archive at MRC Harwell to screen for additional allelic variants expressing more subtle and varied behavioural phenotypes. Endophenotypes associated with schizophrenia and bipolar disorder, such as anxiety, cognitive deficits and sensorimotor gating deficits, can be characterised in these mutants and, together with molecular characterisation, this can validate these genes as risk factors. While mutations in Ank3 and Tcf4 proved to be non-functional, two mutations in Cacna1c have been associated with anxiety phenotypes and differences in EEG power spectra, as well as causing a cardiac phenotype.
Ultra-cold atoms in optical lattices: simulating quantum spin systems
Keywords: Lipkin-Meshkov-Glick
quantum simulation
optical lattice
Ising
Wannier
quantum physics
laser

Optical lattices provide ideal experimental tools for simulating a wide variety of physical systems. They exhibit excellent coherence properties, their microscopic dynamics are well-understood, and they can be dynamically controlled with great precision. Recent advances in cooling and trapping gases of dipolar molecules and Rydberg atoms have further increased the versatility of optical lattices as quantum simulators, particularly for solid state systems possessing long-range interactions.
In this thesis we further examine the microscopic properties of cold atoms trapped in an optical lattice, going beyond the case where the lattice axes are orthogonal. We present a transformation of the single-particle energy eigenstates to a complete, orthonormal basis of so-called 'generalised Wannier functions' that are localised to each lattice site. Generalised Wannier functions, as opposed to ordinary Wannier functions, are formed by mixing states between bands and are required when the bands are degenerate. We modify an algorithm devised by Marzari and Vanderbilt (Phys. Rev. B 56(20) 12847) for calculating maximally localised generalised Wannier functions, specifically to determine these functions for optical lattice systems of arbitrary geometry, including those with degenerate lower bands. Moreover, we overcome an issue with the initialisation of the original algorithm to find the maximally localised set without fail. We then present results for a variety of optical lattice systems in one- and two-dimensions, including hexagonal and Kagomé geometries. In each case we use the generalised Wannier functions to calculate the hopping and interaction parameters, and thus determine a reduced form of the system's Hamiltonian that contains only local interactions.
We also study two spin-1/2 systems with long-range interactions as paradigm examples of the models that can be simulated using optical lattices loaded with dipolar molecules. We first examine the critical properties of a 1D spin-1/2 Ising chain possessing exponentially decaying interactions as the range of the interactions is increased. Using the infinite density matrix renormalisation group method, we calculate the location of the critical point and observe a smooth approach to the classical mean-field result in the limit of infinite-ranged interactions. We go on to consider the quantum dynamics of a single spin-1/2 coupled to a bath of interacting spins as a model for decoherence in solid state quantum memories. The large degree of symmetry of the bath, described by the infinite-ranged Lipkin-Meshkov-Glick model, allows us to find parameter regimes where the initial qubit state is revived at well-defined times after the qubit preparation. We observe that these times may become independent of the bath size for large baths and thus enable faithful qubit storage even in the presence of strong coupling to the bath.
The role of UHRF1 in Fanconi anemia pathway
Keywords: Fanocni Anemia pathway
DNA repair
DNA damage sensor

Fanconi Anemia (FA) is a genetic disease caused by mutations in any one of the identified 16 genes. The corresponding proteins are known as FA proteins and compose the FA pathway, which is critical for the cellular response to DNA inter-strand cross-links (ICLs). Many efforts have been drawn to understand the individual role of the FA proteins, yet the mechanism of the initiation of the pathway remains elusive, and in particular, no sensor protein for ICLs has been identified. The aims of this study are to identify such a putative factor and to investigate the role of this factor in DNA ICL repair.
We have analyzed the DNA binding activity of two up-stream players in the FA pathway, i.e. FANCD2 and FANCI, which do not seem to be able to detect the damage directly. We then designed a novel biochemical purification strategy using biotin-labeled ICL DNA to isolate ICL interacting proteins from HeLa nuclear extract. By using mass-spectrometry following the purification, we identified an E3 ligase named UHRF1. We cloned, expressed and purified UHRF1 from Sf9 cells. In vitro data demonstrate that UHRF1 specifically and directly interacts with cross-linked DNA. In vivo experiments indicate that UHRF1 participates in the FA pathway, potentially by recruiting FANCD2 to the sites of DNA damage, and the reduction of cellular levels of UHRF1 by RNA interference (RNAi) sensitizes cells to MMC. We also identified the SRA domain as the region of UHRF1 that is responsible for DNA ICL binding, and the interference of this region results in defects in the cells in ICL repair.
With the unique feature of ICL DNA binding, UHRF1 is identified as a new player in the FA pathway. Future clinical studies will help to determine if UHRF1 is indeed an FA gene of which mutations can generate phenotypes of the disease. Also, a better understanding of the molecular mechanisms underlying UHRF1 in the FA pathway will enable us to develop better and more targeted modes of cancer therapies.
'Under the general designation of socialist': the many-sided-radicalism of John Stuart Mill
Keywords: socialism
John Stuart Mill

This thesis examines why John Stuart Mill thought his political philosophy to be 'under the general designation of socialist' – an ideological position often thought to be antithetical to liberalism, of which Mill is regularly considered an exemplar. It suggests that in order to understand Mill's self-designation, one has to understand the changes his political theory underwent during his 'crisis', and how he developed a new, 'many-sided-radicalism' to replace the one-sided, Benthamite 'philosophical-radicalism' of his youth, in which he had lost his faith. It explains the core principles of many-sided-radicalism (happiness, liberty, equality, progress and harmony), and the institutions Mill felt would foster and uphold them. Finally, it seeks to situate Mill's many-sided-radicalism within three socialist contexts: his definition; contemporary understandings; and a conceptual definition. I utilise Mill's Collected Works to examine a wide range of his writings, bearing in mind the problems of interpretation caused by his 'crisis', in particular changes to the meaning of concepts (not least happiness); his philosophy of history; and his method of persuasion, along with writings by contemporaries, and modern historians and theorists. I conclude that Mill was a socialist on his own understanding of the word, committed to communal ownership of the means of production combined with private, unequal ownership of articles of consumption; work-place democracy; an egalitarian concept of justice; and the achievement of social harmony through co-operation. Historically, although sometimes linked to utopian socialism, he is a co-operative socialist, akin to Edward Vansittart Neale, William Thompson, Louis Blanc, and Phillipe Buchez and his followers. Conceptually, he is a liberal socialist, equally committed to core principles of liberty, equality and community. Recognising Mill's socialism should make us re-evaluate Mill, and the relationship between liberalism and socialism. It also hints at possible answers to questions of social justice which are neither totalitarian nor illiberal.
The talk of the town: oral communication and networks of information in sixteenth-century St. Gallen
Keywords: Communication
Gossip
Humour
Orality
News
Networks
Rumour

This thesis explores oral communication in St. Gallen through the lens of the linen merchant Johannes Rütiner (1501–1556/7). By reconstructing Rütiner's network of informants and probing four genres of communication within their respective social contexts – jokes, gossip, rumour, and memory narratives –, it explores early modern sociability, the circulation of information, and the relationship between oral testimony, manuscript, and print.
Sixteenth-century St. Gallers relied heavily on informal, oral networks to provide them with news and information of all kinds. An individual's access to information was thus to a large degree determined by the social networks within which they spent their life. As St. Gallers sought to secure a place for themselves in such circles, they in turn used jokes, gossip, and information of all kinds as a form of "communicative social capital", allowing them to present themselves as witty, well-connected, and knowledgeable. Rather than treating the instability of oral narratives as evidence of the inherent unreliability of the spoken word, this study proposes to analyse their evolution as a key to early modern mentalities. It also calls into question some of the dominant narratives regarding the printing revolution. Not only did oral communication continue to play a central role in the dissemination of information in the first half of the sixteenth century, but existing systems of "source criticism", developed in the context of dominantly oral networks, moreover cast doubt on the reliability of anonymous prints: because they made their trust in a piece of news conditional on their trust in the messenger, Rütiner and his fellow citizens often preferred oral narratives provided by familiar, trustworthy informants.
Defects in liquid crystals: mathematical and experimental studies
Keywords: Radial hedgehog
fd-virus
Defects in liquid crystals

Nematic liquid crystals are mesogenic materials that are popular working materials for optical displays. There has been an increased interest in bistable liquid crystal devices which support two optically distinct stable equilibria. These devices typically exploit a complex geometry or anchoring conditions, which often induces defects in the equilibria. There remains a great deal to be understood about the structure of the defects and how they stabilize multiple equilibria in modern devices.
This thesis focuses on four problems: the first three explore the effect of confinement and defects on nematic equilibria in simple geometries, with the aim of exploring multistability in these geometries; the fourth problem concerns the fine structure of point defects, essential for future modelling of nematic equilibria in more complex geometries. Firstly, we study nematic liquid crystals confined to two-dimensional rectangular wells using the Oseen-Frank theory. Secondly, we study equilibria within a semi-infinite rectangular domain with weak tangential anchoring on the surfaces. Thirdly, we study nematic equilibria within two-dimensional annuli. We derive explicit expressions for the director fields and free energies of equilibria within these geometries and discuss the stability of the predicted states.
These three problems are motivated by the experimental work on colloidal nematic liquid crystals, which we interpret in the context of our results.
Finally, we study the fine structure and stability of the radial hedgehog defect in the Landau-de Gennes theory with a sixth order bulk potential, relevant to the observability of global biaxial phases in a model with higher order potential terms.
Heralds of change? On the societal function of Weimar Republic journals, 1918-1933
Keywords: Periodicals
Weimar Republic
Social history

This thesis investigates how societal change is represented and negotiated in Weimar Republic journals. I advance the idea that journals serve as unique crystallisations of the negotiation of social change within social communities due to their inherent periodicity, polyphony and materiality. I elucidate how these journals function, both as material objects with their own specific identities and within Weimar society more generally. To do so, I examine six selected journals: Die Weltbühne, Kladderadatsch, Simplicissimus, Die Gartenkunst, Sport im Bild and Fürs Haus. Together, these journals cover a wide range of bourgeois communities, exemplifying a multiplicity of strategies in order to negotiate the challenges posed by modernisation to their communal identities as well as to the individual identities of their creators and readers. This thesis thus establishes a history of small steps visible in the continuous development of the journals’ content and material form, offering an understanding of history as a continuous development of social practices rather than a history of caesuras and breaks.
Accordingly, I propose that journals tell us about culture, their material Eigenlogik setting them apart from newspaper and book alike. I then develop a notion of culture as dynamic and of journal communities as communities of practice. Next, I provide a case study of the Simplicissimus's communal practices materialised in shifts of its editorial content and material form, before generalising these findings to include non-authorial voices in advertisements and letters to the editor. Finally, I investigate the negotiation of modernisation in the form of sport and the "New Woman" in the journals, highlighting the concurrency of discourse and active participation, and the coexistence of rejection and incorporation. Ultimately, Weimar journal communities exhibit a continuity of social practices and identities that span from the Kaiserreich to Nazi Germany, both negotiating and furthering modernisation in the process.
God at work: an institutional perspective on the impact of religion on organizations
Keywords: Institutional Theory
Institutional Logics
Entrepreneurship
Religion
Hybrid Organizations

The dissertation presents an institutional perspective on the role of values and meaning for organizations focusing on the institutional logic of religion. At its core are Chapter III, a conceptual paper, and Chapters IV and V, empirical papers based on an in-depth two-years long ethnographic case study on the founding process of the first Islamic Bank in Germany. They are framed by an introductory chapter and a conclusion that address the overarching research question of how diverse institutional demands are managed within and beyond the boundaries of organizations, as well as a general literature review chapter that embeds the papers within the wider institutional theory literature.
Chapter III presents a conceptualization that integrates religion, specifically Islam, with entrepreneurship along three interconnected pillars: the entrepreneurial, socio-economic/ethical and religio-spiritual; and outlines how Islam shapes entrepreneurship at the micro-, meso- and macro-level. It suggests the institutional logics perspective to further analyze the impact of religion on organizations, which the subsequent papers build on. Chapter IV extends theory on organizational hybridity by outlining polyphony and polysemy as two mutually reinforcing organizational responses, that allow competing logics to coexist without structurally separating or blending them, and that produce elastic hybridity, showing how hybrid organizations can accommodate competing logics that are both central and incompatible. Chapter V shows how organizations collectively and dynamically co-generate and co-resolve institutional complexity through four combinatory mechanisms: pushing, pulling, clarifying and tolerating. These are subsequently integrated into a framework based on their desired versus required and actual versus perceptual nature. Overall, this dissertation contributes to a better understanding of how organizations manage diverse institutional demands including religion.