Dissertations / Theses on the topic 'MFA phase'

Die Realstruktur des perowskitischen Modellsystems SrTiO3, welches in der Raumgruppe Pm-3m kristallisiert, wird durch die Sauerstoffvakanz als wichtigstem Defekt dominiert. Durch Temperaturbehandlung unter reduzierenden Bedingungen können Sauerstoffvakanzen in die Kristallstruktur eingebracht werden. Aufgrund ihrer positiven Ladung relativ zum Kristallgitter bewegen sie sich im elektrischen Feld entlang des TiO6-Oktaedernetzwerkes. Die Elektroformierung folgt dabei einem Arrheniuszusammenhang, wobei sowohl die Aktivierungsenergie als auch die Mobilität eine deutliche Abhängigkeit von der Kristallorientierung zeigen. Die Umverteilung der Sauerstoffvakanzen führt zu lokalen reversiblen Strukturänderungen, welche die Ausbildung einer neuen migrationsinduzierten feldstabilisierten polaren (MFP) Phase verursachen. In Abhängigkeit von der elektrischen Feldstärke zeichnet sie sich strukturell durch eine tetragonale Verzerrung der ursprünglich kubischen Elementarzelle aus und geht mit dem Verlust der Inversionssymmetrie einher. Die Polarisation in der Struktur wird durch die erwiesene Pyroelektrizität bestätigt und gilt als Grundlage, um anhand eines kristallographischen Symmetrieabstieges die Herleitung der Raumgruppe P4mm zu ermöglichen. Der durch die Migration hervorgerufene intrinsische Defektkonzentrationsgradient ruft eine elektromotorische Kraft hervor, deren Verwendung in einem elektrochemischen Energiespeicher experimentell nachgewiesen wurde. Diese neuen Funktionalitäten sind durch die Anwendung defektchemischer und kristallphysikalischer Konzepte infolge gezielter Materialmodifizierung unter Einfluss von Temperatur und elektrischem Feld zu verstehen<br>The real structure of the perovskite-type model system SrTiO3, crystallizing in space group Pm-3m, is dominated by oxygen vacancies as most important defects. They are introduced in the crystal structure through heat-treatment under reducing conditions. Because of their positive charge relative to the crystal lattice, oxygen vacancies move in an electric field along the TiO6 octahedron network. This electroformation process follows an Arrhenius behavior. Both the activation energy and the mobility show an obvious dependence on the crystal orientation. Redistribution of oxygen defects causes local reversible structural changes, which involve the formation of a migration-induced field-stabilized polar (MFP) phase. In dependence on the electric field strength, this is structurally marked by a tetragonal distortion of the original cubic unit cell and accompanied by a loss of inversion symmetry. The polarisation in the crystal structure is confirmed by the proven pyroelectricity and serves for the argumentation to derive the space group P4mm by means of a crystallographic symmetry descent. The migration-induced intrinsic concentration gradient of oxygen vacancies leads to an electromotive force, whose application as electrochemical energy storage was proven experimentally. These new functionalities are explainable using defect chemistry and crystal physics in consequence of specific material modifications under the influence of temperature and external electric fields

Cette étude trouve un intérêt fondamental dans la compréhension des isothermes à sous-marches qui sont susceptibles d'être observées au cours de l'adsorption, par des zéolithes de topologie MFI, de certains composés qui présentent des caractéristiques géométriques comparables à celles de l'ouverture des canaux de l'adsorbant. Ainsi, l'interaction du trichloroéthène et du tétrachloroéthène, avec trois zéolithes ZSM-5 de rapport Si/Al egal a 26,5, 339 et 500 et une silicalite-1 a été analysée, après une caractérisation préalable, par thermogravimétrie, microcalorimétrie et diffraction des rayons X. L'adsorption du trichloroéthène et du tétrachloroéthène induit un changement de structure monoclinique-orthorhombique des zéolithes riches en silice (Si/Al 339) bien avant le remplissage de 4 molec. /maille à 25°C. Les isothermes d'adsorption du trichloroéthène présentent toujours à 25°C une allure de type I. En revanche, les isothermes d'adsorption du tétrachloroéthène présentent à basse pression une sous-marche dès que le remplissage excède 4 molec. /maille. Cette sous-marche est d'autant plus verticale, plus haute et plus déplacée vers les plus petites valeurs de la pression relative que le rapport Si/Al de l'adsorbant est élevé. De plus, une boucle d'hystérésis est associée a la sous-marche pour les échantillons de rapport Si/Al 339. La sous-marche dans l'isotherme d'adsorption, associée à un pic exothermique dans la courbe de chaleur, a été interprétée comme la signature d'une transition de phase de l'adsorbat. L'existence d'interactions adsorbat-adsorbat fortes est à l'origine de la boucle d’hystérésis (20 kJ. Mol#-#1). Un modèle de remplissage des canaux de la zéolithe est proposé pour chaque espèce adsorbée. Les molécules de trichloroéthène sondent la totalité de la microporosité disponible en formant des chaines de dipôles. Dans le cas du tétrachloroéthène, les quatre premières molécules s'adsorbent aux intersections des canaux droits et des canaux sinusoïdaux puis accèdent, par saut diffusionnel, aux canaux sinusoïdaux. Quatre molécules supplémentaires sont alors adsorbées aux intersections donnant naissance à des chaines sinusoïdales. Cet agencement particulier des molécules par maille de zéolithe donne alors une image de la densification de la phase adsorbée.

Les composés MF3 de structure cubique ReO3, sont le siège d'une transition de phase structurale du 1er ordre par rotation des octaèdres autour de l'axe ternaire, qui conduit à une symétrie rhomboédrique (R3C). La croissance cristalline de ces composés est étudiée et les structures cristallines de AlF3, VF3 et ScF3 sont déterminées. L'étude des fluorures MF3 par diffusion Raman est effectuée et l'attribution des raies est faite par comparaison avec la symétrie des modes en phase cubique. L'étude Raman en température montre l'existence de deux modes mous. La transition peut alors être attribuée à la condensation d'un mode situé au point r de la zone de Brillouin cubique. Les données Raman sont suffisantes pour estimer les constantes de forces et calculer le spectre de phonons en phase cubique. L'évolution des constantes de forces en fonction de la distance interionique suit une loi de type Born Mayer et la densité d'état calculée apparaît dépendante de la fréquence du mode mou R5 de la phase cubique. L'étude dynamique de ces composés, directement dans la phase rhomboédrique a mis en évidence par le calcul la levée de dégénérescence du mode R5 comme observe expérimentalement. Un ajustement des constantes de forces peut être effectué et la transition est décrite dans le cadre de la théorie de Landau.

Neisseria meningitidis (Nm) est une bactérie commensale du nasopharynx humain qui traverse quelques fois la barrière nasopharyngée et se propage dans la circulation sanguine jusqu'à atteindre les méninges. Un bactériophage filamenteux appelé MDA (Meningococcal Disease Associated) est associé aux infections invasives à méningocoques chez les jeunes adultes. Le MDA semble augmenter l'incidence de la maladie en augmentant la colonisation bactérienne au point d'entrée. L'objectif de ce travail a été de comprendre le mécanisme moléculaire précis de l'infection de Nm par le MDA. L'étude des mutants des gènes impliqués dans la machinerie des pili de type IV (PT4) a montré que l'entrée du phage nécessite un PT4 rétractable. Ce résultat est cohérent avec la littérature sur les phages Ff ou CTX qui interagissent directement avec l'extrémité du pilus. Mais aucune preuve de l'interaction du MDA avec l'extrémité du pilus n'a été trouvée. L'interaction possible entre la fibre du pilus et la capside du phage a été examinée. Comme PilE, la piline majeure, est sujette à variation antigénique, des variants de PilE qui diminuent l'entrée du phage ont été identifiés. L'infection par le phage se produit dans des populations de bactéries exprimant des séquences de PilE spécifiques. Par imagerie, nous avons montré que les pili et les MDA s'associaient ensemble. Une analyse de la charge des acides aminés de PilE et celle de la capside soutient l'hypothèse d'une interaction variable selon le variant de PilE. Finalement, il a été montré que les P4T avec un potentiel électrostatique positif favorisaient l'infection par le phage et permettaient, de plus, une forte adhésion des Nm aux cellules humaines. L'inverse est observé pour les P4T chargés négativement. Ce travail présente également les premières caractérisations de la machinerie de sécrétion du phage. Des études préliminaires avaient montré que dans un biofilm formé sur cellules épithéliales, Nm produisaient soit des pili, soit des phages, mais pas les deux en même temps. Nous avons montré que la sécrétion du phage nécessitait PilQ, PilW et TsaP de la machinerie des P4T. Les analyses bio-informatiques suggèrent que l'ORF8 du phage, qui aurait une activité ATPase, s'associerait avec l'ORF11 pour former un complexe qui interagirait avec la sécrétine bactérienne PilQ. Ce modèle est soutenu par des tests d'interaction par double-hybride. Cette interaction mobiliserait les PilQ de la bactérie, les rendant inaccessible à la machinerie de piliation. La surexpression d'ORF8 entraine une inhibition de la piliation. Ces données permettent d'établir un nouveau modèle d'interaction entre les phages filamenteux et les P4T, ce qui pourrait participer à la sélection des souches pathogènes de Nm<br>Neisseria meningitidis (Nm) is a commensal bacterium of the human nasopharynx that sometimes crosses the nasopharyngeal barrier and spreads through the bloodstream to reach the meninges. A filamentous bacteriophage called MDA (Meningococcal Disease Associated) is associated with invasive meningococcal disease in young adults. MDA appears to increase the incidence of the disease by increasing bacterial colonization at the point of entry. The aim of this work was to understand the precise molecular mechanism of infection of Nm by MDA. The study of mutants of genes involved in the type IV pili (T4P) machinery showed that phage entry requires a retractable T4P. This result is consistent with the literature on Ff or CTX phages, which interact directly with the pilus tip. However, no evidence was found for MDA interacting with the T4P tip. The possible interaction between the pilus fiber and the phage capsid was investigated. Since PilE, the major pilin, is subject to antigenic variation, variants of PilE that reduce phage entry were identified. Phage infection occurs in populations of bacteria that express specific PilE sequences. Using imaging, we showed that pili and MDA associate with each other. An analysis of the amino acid charge of the pilin and that of the capsid supports the hypothesis of a variable interaction depending on the PilE variant. Finally, it was shown that T4P with a positive electrostatic potential favored phage infection and allowed the bacteria to adhere strongly to human cells. The opposite is observed for negatively charged T4P. This work also presents the first characterizations of the phage secretion machinery. Previous studies had shown that in a biofilm formed on epithelial cells, Nm produce either pili or phages, but not both at the same time. We showed that phage secretion requires PilQ, PilW and TsaP of the pili machinery. Bioinformatic analyses suggest that phage ORF8, which has ATPase activity, associates with ORF11 to form a complex that interacts with the bacterial secretin PilQ. This model is supported by two-hybrid interaction assays. This interaction would mobilize the bacterial PilQ, making them inaccessible to the piliation machinery. Overexpression of ORF8 inhibits piliation. These data provide a new model for the interaction between filamentous phages and T4P, which could be involved in the selection of pathogenic strains of Nm

Etude du processus de thermolyse de cations (Pr4N+) occlus dans des zéolites par analyse thermique différentielle, calorimétrie différentielle à balayage, spectrométrie de masse, RMN et chromatographie en phase gazeuse

Thesis (Ph.D.)--City University of Hong Kong, 2009.<br>"Submitted to Department of Mathematics in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves [214]-224)

La biolixiviation extractive est un ensemble de technologies visant à récupérer les métaux contenus dans les ressources minérales via l'assistance de microorganismes. Ces technologies ont été mises en œuvre avec succès à l'échelle industrielle et utilisées, soit sous la forme de traitements en tas, soit en utilisant des réacteurs à cuve agitée à grande échelle. Récemment, la biolixiviation a évolué vers l'exploitation de ressources non communes (très faibles teneurs, minéralogie complexe ou forte teneur en soufre) causée par la tendance à la baisse des teneurs moyennes en métaux contenus dans les minerais. La biolixiviation en cuve agitée s'est avérée plus efficace que les traitements en décharge ou en tas pour le traitement des ressources de grande valeur (comme les minerais d'or réfractaire), principalement grâce à un meilleur contrôle du processus. Cependant, ce traitement doit encore être optimisé sur le plan technique pour atteindre une viabilité économique dans le cas des ressources non conventionnelles. Dans ce travail de thèse, un modèle couplé hydrocinétique de biolixiviation en réacteur a été développé pour modéliser et simuler le microenvironnement bactérien et sa réponse aux hétérogénéités locales du réacteur afin d'établir des critères d'optimisation. Pour cela, une étude expérimentale a été réalisée à l'échelle laboratoire afin d'obtenir les données nécessaires à la calibration des différents modèles. Cette étude comprenait des tests de biolixiviation en cuve agitée pour recueillir les paramètres cinétiques, et des études abiotiques pour déterminer les paramètres hydrodynamiques essentiels (Njs, kla). Dans une seconde étude, un modèle CFD multi-échelle solide-liquide a été développé et simulé en utilisant différentes conditions de géométries de mobiles d'agitation, de concentrations en solide et de vitesses d'agitation. L'impact de ces conditions sur l'homogénéité du solide et la contrainte mécanique perçue par les particules a été évalué et des règles de base de dimensionnement ont été extrapolées à partir des résultats. Enfin, un modèle hydrocinétique d'un réacteur de biolixiviation multi-échelle a été développé. Pour cela, un modèle CFD décrivant l'écoulement gaz-liquide a été formulé et simplifié en utilisant une approche par compartiments. Cette approche a été modélisée sur MatLab et combinée avec les résultats précédents sur les modèles cinétiques et d'hydrodynamique solide-liquide. Enfin, le modèle hydrocinétique compartimenté a été utilisé pour caractériser la cinétique de biolixiviation puis comparé aux données expérimentales<br>Extractive bioleaching is a range of technologies aiming at recovering metals contained in mineral resources using biological means. It was successfully implemented at the industrial scale and used either in the form of dump or heap treatments, or by using large-scale stirred tank reactors (STR). Recently, bioleaching is evolving towards the exploitation of unusual resources (very low-grades, complex mineralogy, or high sulphur content) caused by the declining trend in mean ore grades. Bioleaching STR have proven to be more efficient than the dump or heap treatments for the treatment of high-value resources (such as refractory gold ores) mainly thanks to the better control over the process. However, it still needs further technical optimization to reach economic viability in the case of unconventional resources. In this PhD work, a coupled bioleaching STR hydrokinetic model was developed to model and simulate the bacterial microenvironment / response to the local heterogeneities of the tank in order to establish optimization criteria. First, an experimental study was performed at laboratory-scale to obtain the data necessary for the calibration of the various models. This includes bioleaching tests in STR to gather kinetics parameters and abiotic studies to determine essential hydrodynamics parameters (Njs, kla). On a second study, a multi-scale solid-liquid CFD model was developed and simulated using various conditions of impeller geometries, solid concentrations, and agitation rates. The impact of these conditions on solid homogeneity and particle stress was assessed and basic sizing rules were extrapolated from the results. Lastly, a hydro-kinetic model of a multi-scale bioleaching STR was developed. For this, a CFD model describing the gas-liquid flow was developed and simplified using a compartment approach. This approach was modelled on MatLab and combined with previous results on kinetic and solid-liquid models. Finally, the compartment hydro-kinetic model was used to characterize the kinetics of bioleaching and was compared with experimental data

This project was a step forward in improving the voltage profile of traditional low voltage distribution networks with high photovoltaic generation or high peak demand. As a practical and economical solution, the developed methods use a Dynamic Voltage Restorer or DVR, which is a series voltage compensator, for continuous and communication-less power quality enhancement. The placement of DVR in the network is optimised in order to minimise its power rating and cost. In addition, new approaches were developed for grid synchronisation and control of DVR which are integrated with the voltage quality improvement algorithm for stable operation.

The majority of UK’s intermediate level radioactive waste is currently stored in 316L and 304L austenitic stainless steel containers in interim storage facilities for permanent disposal until a geological disposal facility has become available. The structural integrity of stainless steel canisters is required to persevere against environmental degradation for up to 500 years to assure a safe storage and disposal scheme. Hitherto existing severe localised corrosion observances on real waste storage containers after 10 years of exposure to an ambient atmosphere in an in-land warehouse in Culham at Oxfordshire, however, questioned the likelihood occurrence of stress corrosion cracking that may harm the canister’s functionality during long-term storage. The more corrosion resistant duplex stainless steel grade 2205, therefore, has been started to be manufactured as a replacement for the austenitic grades. Over decades, the threshold stress corrosion cracking temperature of austenitic stainless steels has been believed to be 50-60°C, but lab- and field-based research has shown that 304L and 316L may suffer from atmospheric stress corrosion cracking at ambient temperatures. Such an issue has not been reported to occur for the 2205 duplex steel, and its atmospheric stress corrosion cracking behaviour at low temperatures (40-50°C) has been sparsely studied which requires detailed investigations in this respect. Low temperature atmospheric stress corrosion cracking investigations on 2205 duplex stainless steel formed the framework of this PhD thesis with respect to the waste storage context. Long-term surface magnesium chloride deposition exposures at 50°C and 30% relative humidity for up to 15 months exhibited the occurrence of stress corrosion cracks, showing stress corrosion susceptibility of 2205 duplex stainless steel at 50°C.The amount of cold work increased the cracking susceptibility, with bending deformation being the most critical type of deformation mode among tensile and rolling type of cold work. The orientation of the microstructure deformation direction, i.e. whether the deformation occurred in transverse or rolling direction, played vital role in corrosion and cracking behaviour, as such that bending in transverse direction showed almost 3-times larger corrosion and stress corrosion cracking propensity. Welding simulation treatments by ageing processes at 750°C and 475°C exhibited substantial influences on the corrosion properties. It was shown that sensitisation ageing at 750°C can render the material enhanced susceptible to stress corrosion cracking at even low chloride deposition densities of ≤145 µm/cm². However, it could be shown that short-term heat treatments at 475°C can decrease corrosion and stress corrosion cracking susceptibility which may be used to improve the materials performance. Mechanistic understanding of stress corrosion cracking phenomena in light of a comprehensive microstructure characterisation was the main focus of this thesis.

SerpinA12 (vaspin) is thought to be mainly expressed in adipose tissue and has multiple beneficial effects on metabolic, inflammatory and atherogenic processes related to obesity. KLK7 (kallikrein 7) is the only known protease target of vaspin to date and is inhibited with a moderate inhibition rate. In the crystal structure, the cleavage site (P1-P1′) of the vaspin reactive centre loop is fairly rigid compared with the flexible residues before P2, possibly supported by an ionic interaction of P1′ glutamate (Glu379) with an arginine residue (Arg302) of the β-sheet C. A P1′ glutamate seems highly unusual and unfavourable for the protease KLK7. We characterized vaspin mutants to investigate the roles of these two residues in protease inhibition and recognition by vaspin. Reactive centre loop mutations changing the P1′ residue or altering the reactive centre loop conformation significantly increased inhibition parameters, whereas removal of the positive charge within β-sheet C impeded the serpin–protease interaction. Arg302 is a crucial contact to enable vaspin recognition by KLK7 and it supports moderate inhibition of the serpin despite the presence of the detrimental P1′ Glu379, which clearly represents a major limiting factor for vaspin-inhibitory activity. We also show that the vaspin-inhibition rate for KLK7 can be modestly increased by heparin and demonstrate that vaspin is a heparin-binding serpin. Noteworthily, we observed vaspin as a remarkably thermostable serpin and found that Glu379 and Arg302 influence heat-induced polymerization. These structural and functional results reveal the mechanistic basis of how reactive centre loop sequence and exosite interaction in vaspin enable KLK7 recognition and regulate protease inhibition as well as stability of this adipose tissue-derived serpin.

The overarching objective of this study was to establish the extent to which the Multi-Fiber Arrangement impacted on the garment industry of the Kingdom of Lesotho. The quota system which controlled access to the world's biggest textile and clothing markets in the United States (US) and European Union (EU) namely Multi-fiber Arrangement (MFA) was incorporated in 1974. Nonetheless, with the thrust towards the increasingly liberal world market, MFA was abolished on 1 January 2005. As a result countries such as Lesotho had to compete on an equal footing with developed countries. Lesotho depends heavily on textile and clothing exports, thus, it is potentially vulnerable to this change in competitiveness. There have been predictions that the garment industry will suffer as a result of quota abolition and spell the end of thousand of jobs. This study was conducted to understand the various implications of Multi-Fibre Arrangement phase out on the Lesotho garment industry. The study first examines the impact of MFA on the economic growth and employment in Lesotho. Then it determines the consequences of MFA phase out on workers and the garment industry, that is, whether this elimination badly affected the industry and workers. Lastly, it establishes if adequate actions or efforts have been undertaken to attenuate potential negative impacts on workers. The results strongly indicate that MFA had contributed enormously to the Lesotho economic growth. The phasing out has led to job losses and disruption in the industry. However, programs have been put in place to mitigate and manage the negative impacts on workers such as providing training to workers with the aim of improving productivity. By the same token, recommendations have been suggested in order to address the impacts, such as to integrate vertically the industry to enhance production times.<br>Thesis (MBA)-University of KwaZulu-Natal, Durban, 2006.

Research Doctorate - Doctor of Philosophy (PhD)<br>This thesis is primarily concerned with a series of experimental investigations into the synthesis of materials for energy conversion and related applications in hostile environments. The <i>M</i>_n+1<i>AX</i>_n (MAX) phases contain an early transition metal (<i>M</i>-element) a group 3 or 4 element (<i>A</i>-element) and either C or N (<i>X</i>-element) and are a group of ceramics with interesting properties that make them perfectly suited to many difficult and demanding applications. The high potential of the MAX phases has been largely frustrated by difficulties in large scale, economic synthesis. The formation of <i>M</i>_n+1<i>AX</i>_n phases was extensively studied throughout this thesis. Use of <i>M</i>-element oxides as reactants has been intensively investigated with great success. The processing involved in obtaining the metallic form of the <i>M</i>-elements contribute considerably to the high cost of the MAX phases, along with complex and small scale synthesis methodologies currently used. Methods have been developed throughout this work as a means of reducing the <i>M</i>-element oxides, considerably cheaper starting materials, and producing MAX phases via a single step pressureless reactive sintering process. Aluminium has been extensively explored as a reducing agent and aluminothermic reduction was proven capable of forming the majority of tested systems. Separation of the MAX phase alumina composite formed by the exchange reaction has been demonstrated in simple sedimentation experiments, allowing for purification of the MAX phase product. Alternatively carbothermal reduction has been shown in selected systems to produce self-separating products. This process has been shown to produce pure MAX phase products in a single step reaction, a highly desirable trait, and the first time a pure MAX phase has been produced by carbothermal reduction. Additionally investigations into the synthesis and stability of MAX phases in general lead to the discovery of two new compounds belonging to this family, Ti₃GaC₂ and Ti₃InC₂. Issues of energy conversion have been addressed in two ways, through the creation of a novel thermal energy storage material using immiscible materials known as Miscibility Gap Alloys and through the development of a thermionic converter for conversion of heat directly into electricity. Thermal energy storage is critical as it allows for the intermittency of a concentrator solar power plant to be overcome. Misibility Gap Alloys provide high energy density, constant temperature storage in a highly thermally conductive material. A thermionic converter, although in its most preliminary stages with very low power output and efficiency, was designed for high temperature energy conversion. This device can be used as a test bed for the design of a system which could be used as a topping cycle on a concentrated solar thermal power plant. To enhance the power output of the thermionic device, low work function hexaboride materials were investigated and synthesised at considerably lower temperatures than conventionally used. Overall several contributions have been made in novel and potentially economic methods for the production of MAX phases. The development of these synthesis methodologies may alloy for these materials to fulfil their long desired place in demanding environments such as efficient energy conversion. A new class of thermal storage materials was developed which can be used for overcoming the intermittency of concentrated solar thermal power production, which could be coupled with low work function materials in a thermionic energy conversion device in order to improve the efficiency of electricity generation.

碩士<br>嘉南藥理科技大學<br>生物科技系暨研究所<br>98<br>Solid phase extraction (SPE) is the most widely used sample preparation technique for purifying complex samples before their analysis by liquid chromatography (LC) or gas chromatography (GC). In SPE, analytes are partitioned between a solid phase and a liquid phase and the sorbent usually is chosen to have a greater affinity for the analytes than for the sample matrix. Most SPE sorbents are based on silica that has been bonded to a specific functional group. In recent years, there has been a renewed growth in SPE, primarily driven by the introduction of newer packing materials based upon specialized polymer technology that overcomes some of the disadvantages of silica-based materials. In this study, SPE sorbents with high adsorption capacity for ketamine have been synthesized. MAA and EGDMA or TRIM were chosen as functional and cross linking monomers and determined by the ratio of 1:5. The pore properties of these materials are controlled by the percentage of monomers in the polymerization mixture. The rigid was found to increase with the monomer content of the monolith. Poly(MAA-co-EGDMA) and Poly(MAA-co-TRIM) both effectively extracted ketamine from purified water. The effect of pH on adsorption of ketamine on poly(MAA-co-TRIM) from phosphate buffer has been investigated by measuring adsorbed amounts of ketamine in the pH range of 2–12. The adsorbed amount increases largely with increasing pH from 4.0 to 8.0. When the pH was increased to 8, the adsorption of the ketamine on poly(MAA-co-TRIM) reached a maximum and remained almost constant until pH 12. The effect of initial ketamine concentration was determined by contacting 1.0 mg sorbent with 0.5 mL of ketamine solutions (100–5000μM). The maximum adsorption loading, under the studied experimental conditions, found to be about 290 mg/g for poly(MAA-co-TRIM) and 200 mg/g for poly(MAA-co-EGDMA) . Three different types of desorbing solvents were used to remove the adsorbed ketamine from the sorbents. When mobile phase was used as the desorbing solvent, only about 30-40% of the adsorbed ketamine was desorbed, whereas the value increased to 60-84% when methanol/acetic acid (9/1, v/v) was used for the extraction of ketamine from the polymer. The experimental results show that poly(MAA-co-TRIM) and poly(MAA -co-EGDMA) has high adsorption capacity and rapid adsorption/desorption kinetics for ketamine.

博士<br>國立中央大學<br>土木工程學系<br>102<br>The building information model (BIM) technology is a new way to design buildings, and every aspect of buildings can be stored in the BIM database. BIM changes not only the traditional design process but the project stakeholders’ responsibilities. Hence, other software applications such as facility management, disaster mitigation, and energy savings should use BIM as the base data representing their buildings and add customized functionalities into BIM so that the goal regarding comprehensive life cycle information management of buildings can be achieved. The model-driven architecture (MDA) technology is a software development method. It relies on Unified Modeling Language (UML) as a template to describe a software application. Designers can use UML to design, and MDA will transform the model into the codes that can be used to build the real application. Both BIM and MDA are not new technologies. However, no research exists to explore the integration of the two technologies. In this study, an application for handling water valves leakage was generated by using the integrated approach, i.e., BIMAppBuilder. This application’s model consisted of two parts: one was from BIM data and another was designed in the traditional way to describe the new functionalities of the application. The Revit2UML tool was developed to help the transformation process from Revit (a BIM drafting tool) to Umbrello (a UML drafting tool). The Parser tool was developed to help complete the static code-generation aspect of the object model, while the Code Maker tool was for the dynamic aspect, e.g., sequence diagrams. The Project Builder tool was developed to synthesize all the codes generated and create a Visual Studio project for the Revit add-in. Therefore, BIMAppBuilder includes the above four tools, and a socket-based software service tool, Revit Remote Service (RSS), was being developed to further simplify the efforts of developing a BIM-related software service. It can be expected that future BIM-related applications can be automatically generated by using BIMAppBuilder, and with a few modifications for the codes generated, a distributed software service for BIM data retrieval and update can be realized by using RSS. Since BIM can be applied in each phase of a building’s life cycle, the proposed approach may help creation of these applications efficiently and effectively, especially for the operation and maintenance phase of a building.

Die Realstruktur des perowskitischen Modellsystems SrTiO3, welches in der Raumgruppe Pm-3m kristallisiert, wird durch die Sauerstoffvakanz als wichtigstem Defekt dominiert. Durch Temperaturbehandlung unter reduzierenden Bedingungen können Sauerstoffvakanzen in die Kristallstruktur eingebracht werden. Aufgrund ihrer positiven Ladung relativ zum Kristallgitter bewegen sie sich im elektrischen Feld entlang des TiO6-Oktaedernetzwerkes. Die Elektroformierung folgt dabei einem Arrheniuszusammenhang, wobei sowohl die Aktivierungsenergie als auch die Mobilität eine deutliche Abhängigkeit von der Kristallorientierung zeigen. Die Umverteilung der Sauerstoffvakanzen führt zu lokalen reversiblen Strukturänderungen, welche die Ausbildung einer neuen migrationsinduzierten feldstabilisierten polaren (MFP) Phase verursachen. In Abhängigkeit von der elektrischen Feldstärke zeichnet sie sich strukturell durch eine tetragonale Verzerrung der ursprünglich kubischen Elementarzelle aus und geht mit dem Verlust der Inversionssymmetrie einher. Die Polarisation in der Struktur wird durch die erwiesene Pyroelektrizität bestätigt und gilt als Grundlage, um anhand eines kristallographischen Symmetrieabstieges die Herleitung der Raumgruppe P4mm zu ermöglichen. Der durch die Migration hervorgerufene intrinsische Defektkonzentrationsgradient ruft eine elektromotorische Kraft hervor, deren Verwendung in einem elektrochemischen Energiespeicher experimentell nachgewiesen wurde. Diese neuen Funktionalitäten sind durch die Anwendung defektchemischer und kristallphysikalischer Konzepte infolge gezielter Materialmodifizierung unter Einfluss von Temperatur und elektrischem Feld zu verstehen.<br>The real structure of the perovskite-type model system SrTiO3, crystallizing in space group Pm-3m, is dominated by oxygen vacancies as most important defects. They are introduced in the crystal structure through heat-treatment under reducing conditions. Because of their positive charge relative to the crystal lattice, oxygen vacancies move in an electric field along the TiO6 octahedron network. This electroformation process follows an Arrhenius behavior. Both the activation energy and the mobility show an obvious dependence on the crystal orientation. Redistribution of oxygen defects causes local reversible structural changes, which involve the formation of a migration-induced field-stabilized polar (MFP) phase. In dependence on the electric field strength, this is structurally marked by a tetragonal distortion of the original cubic unit cell and accompanied by a loss of inversion symmetry. The polarisation in the crystal structure is confirmed by the proven pyroelectricity and serves for the argumentation to derive the space group P4mm by means of a crystallographic symmetry descent. The migration-induced intrinsic concentration gradient of oxygen vacancies leads to an electromotive force, whose application as electrochemical energy storage was proven experimentally. These new functionalities are explainable using defect chemistry and crystal physics in consequence of specific material modifications under the influence of temperature and external electric fields.

Low-temperature magnetic force microscopy was used to study the phase diagram of a La1/3Pr1/3Ca1/3MnO3 thin film grown on a (110) NdGaO3 (NGO) substrate by pulsed laser deposition. Traditionally, one can observe the phase change at the nanoscale level as the sample is cooled from room temperature through the transition temperature to liquid nitrogen temperatures, but in this case a fixed voltage ranging from 0 V to 31 V was applied before each cooling cycle. From in and ex situ transport measurements, it is observed that the temperature of the peak of the transition increases with applied field; however, the MFM images show that the magnetic transition begins at a lower temperature with the same increase in field. Thus, this dissertation shows that a new voltage control exists for the phase transition in certain manganites.<br>text