Cellulose Nanocrystals have been used in a wide range of applications including cement composites as a strength enhancer. This work analyses the use of CNC from several sources and production methods, and their effects on rheology and hydration of pastes made using different cement types with different compositions. Cement Types I/II and V were used to prepare pastes with different water to cement ratios (w/c) and measure the changes in rheology upon CNC addition. The presence of tricalcium aluminate (cement chemistry denotes as C3A) made a difference in the magnitude of CNC effects. At dosages under 0.5vol% to dry cement, CNC reduced the yield stress up to 50% the control value. Pastes with more C¡A reduced yield stress over a wider range of CNC dosages. CNC also increased yield stress of pastes with dosages above 0.5%, twice the control value for pastes with high C3A content at 1.5% CNC and up to 20 times for pastes without C3A at the same dosage.<br>All the CNCs used were characterized in length, aspect ratio, and zeta potential to identify a definitive factor that governs the effect in the rheology of cement pastes. However, no definitive evidence was found that any of these characteristics dominated the measured effects.<br>The CNC dosage at which the maximum yield stress reduction occurred increased with the amount of water used in the paste preparation, which provides evidence of the dominance of the water to cement ratio in the rheological impact of CNC.<br>14<br>Isothermal calorimetry showed that CNC cause concerning retardation effects in cement hydration. CNC slurries were then tested for sugars and other carbohydrates that could cause the aforementioned effect, then slurries were filtered, and impurities were detected in the filtrate, these impurities were quantified and characterized, however, the retardation appeared to be unaffected by the amount of the species detected, suggesting that the crystal chemistry, which is a consequence of the production method, is responsible of this retardation.<br>This work explores the benefits and drawbacks of the use of CNC in cement composites by individually approaching rheology and heat of hydration on a range of physical and chemical tests to build a better understanding of the observed effects.<br>Understanding the effect of CNCs on cement paste rheology can provide insights for future work of CNCs applications in cement composites.

Das Bronchialkarzinom ist die häufigste Todesursache bei den Krebserkrankungen und weist eine schlechte Prognose auf. Die Behandlung besteht aus einer Chemotherapie mit platinbasierten Medikamenten, doch der Erfolg ist unbefriedigend. In den letzten Jahren wurden zielgerichtete Therapien gegen Proteine wie den EGFR entwickelt. Klinische Studien zeigten, dass nur Subpopulationen von den Medikamenten Erlotinib und Cetuximab profitieren. Eine bessere (Vor-)Selektion der Patienten ist wünschenswert, um unnötige Behandlungen zu vermeiden. Für diese Analysen bedarf es relevanter präklinischer Modelle. Im Rahmen dieser Arbeit wurden 25 Xenograftmodelle des Lungenkarzinoms vergleichend charakterisiert. Ein Schwerpunkt bestand im Vergleich der Xenografts mit ihren Patiententumoren. Die Analyse der Histologie, der Proliferationsmarker als auch der Genexpressionsprofile fand übereinstimmende Ergebnisse in den Patiententumoren und ihren abgeleiteten Xenografts. Mit Hilfe von mRNA-, Protein- und SNP-Profilen ressistenzassoziierter Marker der Chemotherapie konnte die Bedeutung der Modelle zur Charakterisierung von prädiktiven und prognostischen Markern aufklärt werden. Diese Arbeit untersuchte auch Marker der anti-EGFR-Therapien. mRNA- und Proteinprofile der ERBB-Rezeptoren sowie der Liganden wurden erstellt und stimmten mit publizierten klinischen Daten überein. Genexpressionsstudien in Erlotinib Respondern und Non-Respondern zur Therapieoptimierung identifizierten den Wachstumsfaktor VEGFA als Ziel für eine Kombinationsbehandlung mit dem Angiogeneseinhibitor Bevacizumab. Die Kombination von Bevacizumab mit Erlotinib führte zu einem reduzierten Tumorwachstum. Die Ergebnisse dieser Arbeit machten deutlich, dass die individuellen Tumoreigenschaften in den patientenabgleiteten Xenografts auf Gen- und Proteinebene erhalten bleiben und diese als Modelle zur Markeranalyse sowie zur Therapieoptimierung eingesetzt werden können. / Lung cancer is still one of the most frequent cancers worldwide. The treatment option is classical chemotherapy that is based upon the combination of platin-based drugs. But no further improvement seems to be possible. For some years targeted drugs against single proteins like the EGFR were developed. The clinical trials showed that only subpopulations of patients benefit from the treatment. A better selection of patients to avoid treatment would be helpful. Therefore, pre-clinical models that are suitable for analysis and that represent clinical populations of patients are required. In this work 25 patient derived xenografts from lung cancer were intensely studied. First, the xenografts were compared with their corresponding patient tumor. The analysis of the histology and the expression of proliferation and epithelial or mesenchymal markers showed concordance of the patient tumor and the derived xenograft. The gene expression profiles were also maintained. Further analysis should elucidate the relevance of the xenografts as models for the characterisation and validation of predictive and prognostic markers. SNP, mRNA and protein expression profiles of resistance markers for chemotherapy were generated and showed similarities with clinical data. As marker for the anti-EGFR targeted therapies the ERBB receptors and the ligands of the EGFR were analysed. The mRNA and protein expression profiles resemble clinical data sets. An optimisation of the therapy should be achieved with gene expression studies. The vascular endothelial growth factor A was identified for a combination treatment with the anti-angiogenic drug bevacizumab in erlotinib resistant tumors. The combination of erlotinib and bevacizumab reduced the tumor growth in selected models. In summary, the analysis could show that the individual characteristics of the patient tumor were maintained in the xenograft. The models are a reliable tool for studies designed to improve treatment strategies.

Technology entrepreneurs and managers aim to navigate emerging technology ventures and innovations towards successful commercialisation and business development, often over long periods of time. However, this is challenging due to high uncertainties associated with planning and navigating relevant market and business drivers, technological resources and capabilities, and applications. Failure to understand and manage these uncertainties appropriately can lead to undesired consequences and poor outcomes in the realisation of value creation and capture. This research firstly built a knowledge base of technology ventures by conducting a literature review, enabling the development of a conceptual retrospective roadmapping framework as the basis for characterising the emergence of technology ventures. This leads to an analysis of 13 case studies, characterising phases, transitions, patterns, enablers and barriers associated with the emergence of technology ventures. A conceptual model, the so-called ‘emergence archetypes’, was then developed by conducting an in-depth analysis with a further 19 case studies. The concept provides practical insights regarding how emerging technology ventures can be exposed to different levels of technological and market uncertainties along the journey of technology commercialisation and business development. Finally, a strategy visualisation tool and process have been designed based on the research outputs, and a focus group was then conducted with industrial practitioners to review and evaluate the research outputs for practical use in industry. In total, 32 case studies and a focus group have been conducted in the United Kingdom, The Netherlands, Japan, Australia and the United States. Overall, this research demonstrates that characterising technology venture emergence, by applying roadmapping principles, provides significant implications for both researchers and practitioners of strategy and innovation. Success or failure of emerging technology ventures, in terms of value creation and capture, is not only directly related to products or services, but more broadly to the innovation systems in which the technology ventures operate. By demonstrating the characterisation of technology venture emergence, the conceptualisation of emergence archetypes and the strategy visualisation tool and process development, this research shows that applying roadmapping is an appropriate method to characterise and improve emerging technology venturing practices, supporting value creation and capture.

In the drive towards higher strength alloys, a diverse range of alloying elements is employed to enhance their strength and ductility. Limited solid solubility of these elements in steel leads to segregation during casting which affects the entire down-stream processing and eventually the mechanical properties of the finished product. The work presented in this PhD shows that segregation of alloying elements during casting, particularly aluminium, leads directly to banding in the final product. It has been demonstrated that no significant homogenisation is possible in this alloy within practical time constraints of the industrial thermo-mechanical process. A through-process model was developed to design a thermo-mechanical treatment aimed at reducing the effects of segregation on the formation of banding. A new polynomial function for calculating the local phase transformation temperature (Ae3) between the austenite + ferrite and the fully austenitic phase fields during heating and cooling of steel is presented. Material was produced both with and without banding and used to study the effect upon the mechanical properties. The banded steel variants show a significant reduction in tensile strength for a similar level of ductility compared to non-banded variants. In situ measurement under uniaxial loading using high-energy synchrotron diffraction allowed direct quantification of the impact of the mechanically induced transformation of metastable austenite on the work- hardening behaviour. The results reveal that the mechanically induced transformation of austenite does not begin until the onset of matrix yielding and the experimental evidence demonstrates that the austenite to martensite transformation increases the work-hardening rate of the ferrite phase and delays the onset of Stage-III hardening until the yield point of austenite. The increase in work-hardening rate (and thus work required) supports a driving force approach to transformation induced plasticity. The transformation work required leads to an increase in the macroscopic work-hardening rate after matrix yielding which offsets the decrease in the work-hardening rate in the ferrite and martensite phases up to the UTS. Steels with a high degree of banding do not show this extra contribution due to the more dominant anisotropic effect of martensite bands on the work-hardening of ferrite coupled to increased mechanical austenite stability as a result of increased carbon content. A list of revisions as requested by the examiners is produced on pages 18 and 19 of the thesis for examination. Abstract: In the drive towards higher strength alloys, a diverse range of alloying elements is employed to enhance their strength and ductility. Limited solid solubility of these elements in steel leads to segregation during casting which affects the entire down-stream processing and eventually the mechanical properties of the finished product. The work presented in this PhD shows that segregation of alloying elements during casting, particularly aluminium, leads directly to banding in the final product. It has been demonstrated that no significant homogenisation is possible in this alloy within practical time constraints of the industrial thermo-mechanical process. A through-process model was developed to design a thermo-mechanical treatment aimed at reducing the effects of segregation on the formation of banding. A new polynomial function for calculating the local phase transformation temperature (Ae3) between the austenite + ferrite and the fully austenitic phase fields during heating and cooling of steel is presented. Material was produced both with and without banding and used to study the effect upon the mechanical properties. The banded steel variants show a significant reduction in tensile strength for a similar level of ductility compared to non-banded variants. In situ measurement under uniaxial loading using high-energy synchrotron diffraction allowed direct quantification of the impact of the mechanically induced transformation of metastable austenite on the work- hardening behaviour. The results reveal that the mechanically induced transformation of austenite does not begin until the onset of matrix yielding and the experimental evidence demonstrates that the austenite to martensite transformation increases the work-hardening rate of the ferrite phase and delays the onset of Stage-III hardening until the yield point of austenite. The increase in work-hardening rate (and thus work required) supports a driving force approach to transformation induced plasticity. The transformation work required leads to an increase in the macroscopic work-hardening rate after matrix yielding which offsets the decrease in the work-hardening rate in the ferrite and martensite phases up to the UTS. Steels with a high degree of banding do not show this extra contribution due to the more dominant anisotropic effect of martensite bands on the work-hardening of ferrite coupled to increased mechanical austenite stability as a result of increased carbon content.

Résumé confidentiel / Résumé confidentiel

Online social networks (OSNs) have seen a remarkable rise in the presence of automated social agents, or social bots. Social bots are the new computing viral, that are surreptitious and clever. What facilitates the creation of social agents is the massive human user-base and business-supportive operating model of social networks. These automated agents are injected by agencies, brands, individuals, and corporations to serve their work and purpose; utilising them for news and emergency communication, marketing, social activism, political campaigning, and even spam and spreading malicious content. Their influence was recently substantiated by coordinated social hacking and computational political propaganda. The thesis of my dissertation argues that automated agents exercise a profound impact on OSNs that transforms into an array of influence on our society and systems. However, latent or veiled, these agents can be successfully detected through measurement, feature extraction and finely tuned supervised learning models. The various types of automated agents can be further unravelled through unsupervised machine learning and natural language processing, to formally inform the populace of their existence and impact.

"Instead of studying, for example, how the psychology of personality limits and prevents real social and political change, we should be studying how political and ideological changes create new personalities and individual needs and motives." The above quotation is from social psychologist Professor John Turner, who is one of the two theorists, the other being Henri Tajfel, most responsible for the Social Identity Perspective, the principle subject of this thesis. The Social Identity Perspective is an approach to Social Psychology that incorporates two sub-theories: Tajfel's Social Identity Theory and Turner's Self-Categorization Theory. This thesis is based upon using the perspective for the purposes of creating more realistic and believable fictional characters in realist fiction. For the purposes of this thesis Pam Morris' definition of realism will be used, that being, 'any writing that is based upon an implicit or explicit assumption that it is possible to communicate about a reality beyond the writing.' According to both theories, individuals can develop two principal identities: the personal self, which is to say a collection of idiosyncratic qualities that define them as a unique individual, and a collective self (or social identity) that encapsulates the status and characteristics of the social groups they belong to in opposition to other social groupings. Turner theorised that the personality of a human being is heavily influenced by their social context at an unconscious level. This influence can be made manifest by their parents, by their school friends and work colleagues, by their romantic partners, and especially by the collective cultural expectations native to the area they choose to reside in. Turner put forward the concept that our personality and actions are therefore influenced by society at the level of how the individual defines himself or herself. This occurs without agency on the part of the individual. These social belief systems therefore mould what the individual thinks, their actions, and their motivations. This thesis will demonstrate a method of usage for elements of Social Psychology, specifically the Social Identity Perspective that underpins the actions, interactions and motivations of the fictional characters contained within the thesis's creative element. It is the contention of this thesis that The Social Identity Perspective will assist an author in marrying together ever more realistic characterisation to other areas of writer research already extensively drawn upon by the author such as those projects focused upon creating a more realistic setting in a historical novel for instance. As previously stated it is the intention of this thesis to apply aspects of social psychology to the creation of realist texts only, the findings however may also be of use to authors who write in other genres, after all even the writer of fantastic fiction still requires characters whose actions are fundamentally recognisable and justifiable to the reader in order for them to be able to make sense of the fiction and as Henry James said, 'one can speak best from one's own taste, and I may therefore venture to say the air of reality (solidity of specification) seems to me to be the supreme virtue of a novel'. It is the aim of this thesis that its findings may highlight the potential of using The Social Identity Perspective and other adjuncts of Social Psychology as tools for both plot construction and character development that is completely realistic. This may then lead to other areas of research, some of which are suggested in the concluding chapter of this thesis.

Les microsphères polymériques, biodégradables et biocompatibles sont prometteuses comme échafaudages pour fournir des cellules aux tissus sans dommage et améliorer la réponse des cellules souches. Il a été montré que les microparticules à base de PLGA à base de protéines ECM préparées par une technique d'extraction par solvant en émulsion améliorent l'adhésion et la prolifération des cellules souches. Bien qu'un certain effet biologique du revêtement protéique sur les microparticules de polymère soit établi, il n'est pas bien compris car des informations détaillées sur l'interaction entre les propriétés de surface des particules chimiques et physiques, l'adsorption protéique et la réponse cellulaire restent floues. Le but de cette étude est d'établir une relation entre les propriétés de surface des particules qui proviennent des variables utilisées lors des formulations, l'adsorption des protéines et la réponse des cellules souches pour permettre une conception plus rationnelle des microparticules. Deux types de polymères différents (PLGA et PLGA-P188-PLGA) et deux stabilisants d'émulsion différents; un polymérique PVA et une huile polaire Propylène glycol ont été utilisés pour préparer quatre types de particules dans un procédé en émulsion. Les particules ont été caractérisées en termes de taille, charge, topographie et morphologie et chimie de surface Identification des effets des variables dans la chimie et l'émulsifiant des polymères Des surfaces de polymère plat recouvertes de spins sont générées pour comprendre les interactions entre les polymères et les molécules d'adhésion de la fibronectine et de la poly-D-Lysine pour la fonctionnalisation des microparticule. / Polymeric, biodegradable and biocompatible microspheres are promising as colloidal scaffolds to deliver cells to tissues without damage and to enhance stem cell survival. It has been shown that PLGA (poly(lactic-co-glycolic acid)) based microparticles prepared by an emulsion solvent extraction technique and functionalised with ECM proteins improves stemcell adhesion and proliferation. While it is established that the presence of proteins in these systems has abiological effect, the interplay between microparticle properties and cells is poorly understood because there lationship between chemical and physical particle surface properties, protein adsorption and cell response remain unclear. Protein adsorption on a polymer particle surface is a complex phenomenon that is affected by different interfacial mechanisms/forces (e.g. DLVO and non-DLVO forces) and inherents tructural properties of macromolecules (e.g. polymers, surfactants, peptides and proteins) present on surface, establishing the parameters that involves inprotein/peptide adsorption on microparticles insights the logical design of the particles as a biomaterial useby contributing the understanding of another related complex phenomenon of the colloidal biomaterial-cell interface interaction in tissue engineering where limited study available to fully understand the concept.The purpose of this study is to investigate the impact of different formulation approaches on the physicochemical properties of the microparticles and identify connections between the particle properties, protein adsorption and ensuing cell response on these materials. To examine these, two different polymertypes (PLGA and PLGA-P188-PLGA) and two different emulsion stabilizers; a polymeric surfactant (PVA(Polyvinyl alcohol) and a polar oil propylene glycol were used to prepare four different types of particles in an emulsion process (O/W). Particles were characterized in terms of size, charge, topography, morphology and surface chemistry to identify the effect of the variables of polymer chemistry and use of surfactant on particle properties in first part of the study. Spin coated flatpolymer surfaces were generated to understand the interactions between the polymers and the proteins (fibronectin /poly-d-Lysine).

Particles and macromolecular components, including biopolymers (protein and carbohydrate), are viewed as the main foulants in the complex feed submerged membrane filtration systems such as membrane bioreactor (MBR). This work focused on two aspects of fouling in complex fluids: 1- Assessing fouling propensity and mechanisms for various model solutions. 2- Using of two specific solutions modelling biomass found in MBR for a better understanding of the fouling mechanisms in submerged MBR processes. Filtrations were carried out with 0.22 ??m PVDF hollow fibre membrane. Alginate was used as a model for polysaccharide, bovine serum albumin (BSA) as a model for protein, (un)washed yeast and bentonite were representing suspended solid contents. According to the data obtained during this study the fouling propensity of each model solution was classified as follow in a decreasing order: Alginate &gt unwashed yeast &gt washed yeast &gt BSA &gt bentonite for one-component solutions; and Alginate-washed yeast &gt Alginate-BSA &gt Alginate-bentonite &gt Alginate-unwashed yeast for two-component solutions. Introducing the alginate increased the reversible fouling (except BSA). Passive adsorption had a significant effect on fouling of alginate even before the beginning of the filtration. Washed yeast and a mixture of washed yeast + BSA were then used as model solutions to simulate the activated sludge found in MBR. The concentration of washed yeast and BSA used in this study were calculated in order for the characterisations of the two model solution to match (in terms of biopolymer contents) those of MBR biomasses reported in the literature. By rinsing, backwashing and chemical cleaning of the membrane, three fouling layers of upper, intermediate and lower were defined respectively. Results obtained from the analysis of the biopolymers found in the cleaning solutions allow a better understanding of the fouling mechanisms occurring for the two model solutions used in this study: for washed yeast, the lower layer and for washed yeast + BSA , the upper and intermediate layers were found to have relatively high biopolymeric composition. This was explained by higher concentration of solids on the membrane surface and by higher biopolymer interactions when washed yeast was mixed with BSA.

This thesis systematically investigates the effects of a recently developed modified ageing procedure of aluminium alloys, termed the T6I6 temper, on the microstructural development and mechanical properties of the Al ??? Mg ??? Si - Cu alloy 6061. For the T6I6 temper, a conventional single stage T6 temper is interrupted by an ageing period at a reduced temperature (65??C) to facilitate secondary precipitation, before resuming the final ageing at the temperature of the initial T6 treatment. The T6I6 temper was found to cause simultaneous increases in tensile properties, hardness, and toughness as compared with 6061 T6. Al ??? Mg ??? Si ??? Cu alloys are medium strength alloys widely used in the automotive industry and their further improvement is underpinned by stringent demands for weight reduction placed on the transportation industry in recent years. The potential for further improvement of the mechanical properties was found in the control of secondary precipitation that may take place even in some fully aged alloys when exposed to reduced temperatures. The overall improvement in the mechanical properties of 6061 T6I6 was attributed to the formation of finer and more densely dispersed precipitates in the final microstructure. The refinement of precipitates was facilitated by control of the precipitation processes and gradual evolution of the microstructure throughout each stage of the T6I6 treatment. The results indicated that the concentration and the chemical environment of the vacancies controlled the precipitation processes in this alloy. Findings also show that the proportion of the different precipitate phases present in the final microstructure, as well as the amount of the solute in these precipitates, can be controlled and modified utilizing secondary precipitation. A number of analytical techniques were used in this study. The evolution of the microstructure was studied using Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM) and Three Dimensional Atom Probe (3DAP). Vacancy-solute interactions were studied using Positron Annihilation Lifetime Spectroscopy (PALS) and 3DAP. The distribution of the solute was studied using 3DAP and Nuclear Magnetic Resonance (NMR). Differential Scanning Calorimetry (DSC) was used to identify precipitation reactions and to determine the stability of vacancy-associated aggregates.