This work presents findings from experiments carried out using the neutron Laue method in tandem with laboratory source X-ray diffraction to characterise a series of organic molecular complexes which exhibit interesting, and potentially “tunable”, temperature dependent charge transfer effects, such as proton migration and proton disorder within hydrogen bonded networks. These subtle processes are studied by variable temperature neutron diffraction studies, allowing the positional and anisotropic displacement parameters of the hydrogen atoms to be refined accurately and their evolution with temperature followed. The hydrogen atom behaviour is found to be influenced by the local environment, including weak intermolecular interactions in the vicinity of the hydrogen bond under study. Complexes of urea and methyl substituted ureas with small organic acids are presented, which show robust and reproducible structural motifs. In favourable circumstances, these contain short, strong hydrogen bonds (SSHBs) within which the proton may undergo temperature dependent migration. By synthesising a number of complexes containing SSHBs, potential routes to the design of proton migration complexes are found, which utilise crystal engineering principles and pKa matching. Variable temperature studies conducted on these complexes also show unusual thermal expansion properties and phase transitions in urea-acid complexes which do not display proton migration. Systems containing hydrogen bonded dimers of 3,5-dinitrobenzoic acid are also studied, and shown to contain temperature proton disorder within moderate strength hydrogen bonds linking the dimers. The presence and potential onset temperature of any disorder is found to be influenced by interactions around the acid dimers and potential routes to controlling proton disorder are discussed. Complexes of the proton sponge, 1,8-bis(dimethylamino)napthalene (DMAN), with organic acids are also presented, in which the structures have been determined using neutron diffraction. DMAN readily accepts a proton from the acid co-molecules used in forming the complexes, forming a strong intramolecular SSHB within the protonated DMAN. Strong intermolecular hydrogen bonds are also induced between the acid molecules in many cases. The neutron studies presented here investigate the effect of weak interactions on the behaviour of hydrogen atoms located within these SSHBs, and also indicate over what distance such interactions significantly affect the hydrogen atom behaviour.

Properties of cast aluminum components can be improved by strategically placing ferrous inserts to locally improve properties such as wear resistance and stiffness. A cost-effective production method is to cast-in the insert using the solidification of the molten aluminum as a joining method. Metallurgically bonding between the metals could potentially improve both load and heat transfer across the interface. The metallurgical bond between the steel and the aluminum has to be strong enough to withstand stresses related to solidification, residual stresses, thermal expansion stresses, and all other stresses coupled with the use of the component. Formation of a continuous defect free bond is inhibited by the wetting behavior of aluminum and is governed by a diffusion process which requires both energy and time. Due to the diffusional nature of the bond growth in combination with post manufacturing heat treatments defects such as Kirkendall voids can form. The effect of aluminum alloying elements during liquid-solid bond formation in regards to microstructural changes and growth kinetics has been described. A timeframe for defect formation during heat treatments as well as microstructural changes has been established. The effect of low melting point coatings (zinc and tin) on the nucleation of the metallurgical bond has been studied as well the use of a titanium coating for microstructural modification. A set of guidelines for successful metallurgical bonding during multi- material metal casting has also been constructed.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Física, Programa de Pós-Graduação em Física, 2016. / A alternância dos comprimentos de ligação (Bond Length Alternation, BLA) em cadeias moleculares conjugadas longas tem sido tópico de discussões por muitas décadas, tanto experimental quanto teoricamente. O BLA é um parâmetro estrutural que vem da diferença entre o comprimento de ligações duplas e simples ao longo da cadeia conjugada. Neste trabalho nós utilizamos um método estatístico muito utilizado em várias áreas do conhecimento, a Análise dos Componentes Principais (do inglês Principal Components Analysis - PCA), criado por Karl Pearson em 1901, para redefinir o parâmetro BLA. Com esta técnica calculamos um parâmetro estrutural, comparável ao BLA, de um grupo de 17 moléculas derivadas de tertiofeno e, a partir disto, fizemos comparações com a forma mais comum de calcular o BLA, o que nos forneceu uma forma alternativa de calcular este parâmetro. Com a PCA podemos ir mais além ao cálculo do parâmetro estrutural e, por exemplo, podemos identificar quais ligações têm maior relevância para o valor do BLA. Outro ponto desta análise que merece destaque, foi mostrar a evolução dos coeficientes gerados por esta técnica, chamados de PC1, assim como, a evolução dos valores do BLA com o aumento do número de moléculas presentes no grupo inicial para o cálculo e a diferença em relação a aromaticidade de tais moléculas, mostrando qual o número mínimo para que esta técnica possa ser aplicada. / The Bond Length Alternation (BLA) in long conjugated molecular chains have been the topic of discussion for many decades, both experimentally and theoretically. The BLA is a structural parameter that comes from the difference between the length of double and single bonds along the conjugated chain. In this work we have used a statistical method widely used in many fields of knowledge, the Principal Component Analysis, created by Karl Pearson in 1901, to redefine the parameter BLA. With this technique we calculated the BLA of a group of 17 molecules derived from terthiophene and made comparisons with the most common way to calculate the BLA, which provided us with an alternative way to calculate the parameter. With the PCA we can go further the BLA and we can also identify which bonds are more relevant to its value. Another point that is worth mentioning, was showing the evolution of the coefficients generated by this technique, as well as the evolution of BLA values, along with the increasing number of molecules present in the initial group for the calculation and the differences between the aromaticity of such molecules, resulting in the minimum number to apply this technique.

OBJECTIVES: The aim of this study was to evaluate the bond strength of three different veneering porcelains fired over CP Titanium and a CAD/CAM ceramic cemented to CP Titanium. METHODS: Sixty-four bars of CP Titanium grade II (25±1x 3±0.5x 0.5±0.05 mm) were divided randomly into four groups: Group 1: Titankeramik (Vita Zahnfabrik), Group 2: Triceram (Dentaurum), Group 3: Initial Ti (GC), and Group 4: MKII blocks (Vita). Each veneer porcelain (groups 1-3) was applied with dimensions limited to 8x3x1mm and fired on CP Ti bars following the manufacturer’s instructions and ISO 9693 recommendations. Group 4, Vita Mark II blocks were sectioned into sixteen bars (8x3x1mm) and cemented with Multilink Implant cement (Ivoclar) on CP Ti bars. Fifteen specimens from each group were tested for bond strength by Schwickerath crack initiation test (ISO 9693) using an Instron machine; the mode of failure and bond interface was evaluated by SEM / EDS. RESULTSs: The data were analyzed statistically using ANOVA and Tukey ≤ 0.05. Group 4 is significantly higher than the other groups. Group 1 is significantly higher than group 3, but similar to group 2. SEM/EDS analysis reveals that the modes of failure for groups 1 - 4 are a mixture of adhesive, mixed, and cohesive failures. CONCLUSION: Cementing a milled ceramic to CP Ti produces bond strength significantly greater than conventional veneering porcelains. / 2018-09-28T00:00:00Z

Thesis (M.B.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01

The Morita-Baylis-Hillman (MBH) reaction is a carbon-carbon (C-C) bond forming reaction between an activated alkene and an aldehyde. It is a synthetically useful reaction due to the high atom economy and retention of multiple functional groups. Unfortunately, harsh reaction conditions are required during the MBH reaction and unpredictable product stereospecificity have hampered the widespread application of this reaction. Catalysis of the MBH reaction by enzymes has the potential to allow the reaction to occur at ambient conditions, while offering scope for improving the stereospecificity. This thesis focussed on the enzyme design of a MBH enzyme using thermostable fructose-1,6- bisphosphate (FBP) aldolases as scaffolds. These enzymes were chosen because there are common features between the aldol and MBH reactions, both making use of an enol intermediate to attack the aldehyde. In addition, aldolases typically accept a wide variety of substrates. Thermostable aldolases were selected for increased temperature tolerance creating a more desirable catalyst for industrial purposes. Thermoproteus tenax FBP aldolase (TtFBPA; WT and W144L, W144Y, K177A variants) and Staphylococcus carnosus FBP aldolase (ScFruA) were expressed and purified from E. coli. While the retro-aldol reaction catalysed by these enzymes could be easily monitored, the reverse reaction (aldol synthesis) is more difficult to quantify. Multiple methodologies for high throughput spectrophotometric detection of aldol activity were developed as a method of monitoring constructs made during directed evolution of the FBP aldolases. However, none of these proved successful in robustly determining aldol activity. The dihydroxyacetone phosphate (DHAP) mimic 1-hydroxy-3-buten-2-one phosphate (HBOP) was used to assay for MBH catalysis. While crystallographic studies with TtFBPA suggest that HBOP is bound to W144L TtFBPA in a manner compatible with the MBH reaction. NMR studies could not detect any corresponding activity. This suggests further protein engineering will be required to evolve this FBP aldolase to an MBH catalyst. In addition, our crystallographic and NMR studies with TtFBPA reveals this enzyme is capable of catalysing the formation of both FBP and tagatose-1,6-bisphosphate (TBP).Additionally, we determined the first structure of ScFruA. Interestingly, NMR experiments suggested ScFruA lacks significant control of the stereospecificity of the aldol condensation reaction and appears to catalyse the formation of FBP, TBP, xyluose-1,6- bisphosphate and psicose-1,6-bisphosphate. We conclude that while FPB aldolases could indeed provide useful scaffolds for the development of an MBH catalyst, the enzymes lack any inherent activity, necessitating the need for future creation of variants. The success of this approach will depend on the ability to screen mutant libraries for MBH product formation.

Wong Pak Kin. / Year shown on spine: 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliograpical references. / Abstract --- p.i / Acknowledgment --- p.iii / Chapter Chapter I --- Introduction --- p.1 / Chapter Chapter II --- Literature Review --- p.6 / Chapter Chapter III --- Markets and Instruments / Chapter 3.1 --- International Money Markets --- p.15 / Chapter 3.1.1 --- Euro-deposit Market --- p.17 / Chapter 3.2 --- International Bond Markets --- p.20 / Chapter Chapter IV --- Preliminary Analysis of Data --- p.24 / Chapter 4.1 --- Data --- p.24 / Chapter 4.2 --- Descriptive Statistic Of Data Used In This Study --- p.29 / Chapter Chapter V --- Research Methodology / Chapter 5.1 --- Unit Root --- p.33 / Chapter 5.2 --- Cointegration and Error Correction Model --- p.37 / Chapter 5.2.1 --- Cointegration Using Engle and Granger Methodology --- p.39 / Chapter 5.2.2 --- Cointegration Using Johansen Methodology --- p.42 / Chapter Chapter VI --- Empirical Results / Chapter 6.1 --- Testing for Unit Root --- p.47 / Chapter 6.1.1 --- Short-term Interest Rates --- p.47 / Chapter 6.1.2 --- Long-term Interest Rates --- p.48 / Chapter 6.2 --- Testing for Cash-Futures Relationship --- p.54 / Chapter 6.3 --- Multivariate tests for Cointegration and VECM --- p.59 / Chapter 6.3.1 --- Cointegration in the International Money Markets --- p.63 / Chapter 6.3.2 --- Cointegration in the Interest Rate Futures Markets --- p.67 / Chapter 6.3.3 --- Cointegration in the International Bond Markets --- p.71 / Chapter 6.3.4 --- Cointegration in the Bond Futures Markets --- p.75 / Chapter Chapter VII --- Concluding Comment --- p.91 / Reference / Appendix

Le travail de thèse concerne la conception intégrée d'un système de détection et localisation de fautes robuste aux incertitudes paramétriques pour les systèmes hybrides à base de modèle bond graph hybride(BGH) sous la forme LFT (Transformations linéaires fractionnelles). Sur la base de la littérature consultée, les systèmes hybrides sont principalement modélisés pour chaque mode de fonctionnement pour lequel sont générés des indicateurs de fautes déterministes. L'intérêt scientifique de la présente recherche peut être résumé comme suit : (1) l’utilisation d’un seul modèle BGH incertain basé sur les jonctions contrôlées et représentant l’ensemble des modes de fonctionnement, (2) exploitation des propriétés structurelles et causales du BGH LFT pour la génération systématique de Relations de Redondance Analytiques Globales (RRAG) et des seuils de détection robustes aux incertitudes paramétriques et, valides pour tous les modes de fonctionnement, et enfin (3) l’utilisation d’un seul outil : le modèle BGH de Diagnostic (BGHD), pour non seulement la modélisation mais aussi la surveillance en ligne. La démarche développée a été illustrée par un exemple pédagogique représentant un circuit électrique à commutation et par une application à un système hydraulique. / The present PH.D thesis deals with integrated design of robust Fault Detection and Isolation system (FDI) based on Hybrid Bond Graph (HBG) in Linear Fractional Transformation (LFT) form. Based on consulted literature about hybrid systems, each operating mode is mainly modelled by specific model for which are generated determinist fault indicators. The innovative interest of developed research can be summarized as follows: (1) use only one HBG uncertain model based on controlled junctions and representing all operating modes, (2) structural and causal properties of the LFT HBG are exploited for systematic generation of Global Analytical Redundancy Relations (GARRs), and detection thresholds, robust to parameter uncertainties, and (3) finally use of only one tool: the Diagnosis Hybrid Bond Graph (DHBG) for not only modelling but also for online surveillance. The developed approach is illustrated by electrical circuit pedagogical example and application to hydraulic system.

L’électrolyse est une technologie qui permet de répondre à deux problématiques cruciales. D’une part, répondre au besoin en stockage d’énergie liée à l’intégration de sources intermittentes sur les réseaux électriques. D’autre part, répondre à la croissance de la demande en hydrogène, liée aux marchés naissants de l’hydrogène énergie. La nature des besoins liés au développement de la technologie d’électrolyse implique des sollicitations intermittentes dont les impacts quant au fonctionnement du système sont encore méconnus. En ce sens, et face aux manques de la littérature quant à la modélisation à l’échelle système de la technologie d’électrolyse PEM, un nouveau modèle est développé. Pour cela, le formalisme de modélisation graphique Bond Graph est utilisé, notamment pour sa capacité à représenter tout type d’échange énergétique de manière unifiée. Le modèle développé permet de représenter l’intégralité d’un système d’électrolyse PEM, ses différents composants et lois de contrôle associées. Il est validé sur la base du comportement dynamique d’une installation semi-industrielle disponible au CEA. Ce modèle est ensuite utilisé pour identifier et comprendre les enjeux liées à une sollicitation intermittente d’un système d’électrolyse PEM d’un point de vue de l’efficacité du système, de sa flexibilité et de sa capacité de suivi de charge, de sa fiabilité, de sa sûreté ou encore de sa durabilité. Différentes modifications de conception sont simulées et évaluées à la lumière de ces différents enjeux. Finalement, le modèle Bond Graph est exploité d’un point de vue de ses propriétés structurelles afin d’analyser les conditions de surveillabilité d’un système d’électrolyse PEM. / PEM Electrolysis is a technology which to enable to face two major challenges : (i) Fulfill the need of energy storage caused by the integration of intermittent energy sources on electricity networks; (ii) Cope with the growing need of carbon free hydrogen caused by the future market applications of hydrogen energy. These particular needs, regarding electrolysis technology development, involve an intermittent operating mode which impacts on the dynamic behavior of the system remain unknown. Modelling is a critical tool to understand these issues and provide a thorough analysis. State of the art of existing modelling works highlighted that only a few models take into account the dynamic of the whole system including Balance of Plant. Therefore a new dynamic and multiphysic model was developed under Bond Graph formalism. This graphical modelling formalism was selected especially thanks to its ability to represent any kind of power exchange in a unified way. The model enables to represent the whole system including balance of plant and associated control laws. It is validated on the dynamic behavior of an experimental device available in CEA. The model is then used in order to identify and understand the issues related to intermittent operation of a PEM electrolysis system. These issues are related to system efficiency, flexibility, reliability, safety and durability. Regarding these issues, some design changes are simulated and assessed. Finally, the Bond Graph model and its structural properties enable to perform diagnosis and monitorability analyses of a PEM electrolysis system.

The character of James Bond which was first introduced in Ian Fleming’s first novel Casino Royale in 1953 and was then featured in 11 subsequent novels, 2 volumes of short stories, and 24 film adaptations has long been considered to be the ultimate man’s man. There is no feat he cannot conquer, villain he cannot best, or lady he cannot bed. However, in an examination of both the novels and the film, clues exist to Bond’s deeper psyche—most notably his repressed homosexuality. While much discussion has been had of Bond’s misogyny, in many ways it masks his true identity possibly even from himself. Utilizing a framework of theoretical analysis drawing upon Sigmund Freud, Jack Hallberstam, Judith Butler, Susan Sontag, Laura Mulvey, and Charles Klosterman (among many others), this dissertation will fully explore the character Fleming created. Additionally, by examining how the male gaze and camp elements have been utilized by the filmmakers in the Bond films, analysis will be conducted how those elements contribute to a “queerness” of the character’s film incarnations. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection