Metal Organic Frameworks (MOFs) are a new class of nanoporous materials with high surface area, thermal/chemical stability and a taylorable pore size. These properties make MOFs ideal for storage and gas separation applications. Piezoresistive microcantilever sensors are microfabricated devices that are highly sensitive to surface strain due to doped single crystal silicon regions. Changes in resistance generated by surface strain can be measured with a high degree of accuracy using a Wheatstone bridge and basic instrumentation. This thesis will discuss the use of piezoresistive microcantilever sensors as a transduction mechanism for detection of volatile organic compounds (VOC's) using MOF coatings. It will be shown that by coating a microcantilever with MOFs it is possible to detect low levels of different VOC's (hundreds of parts per million). Excellent sensitivity and a simple transduction mechanism make these devices low power and highly compact. Such devices would be capable of detecting a plethora of different analytes at low concentrations. Devices were engineered for maximum response and microfabricated in the cleanroom with high yield. A custom setup for testing the devices was designed and machined. A number of MOFs were selected and tested, their response was recorded and analyzed. Twelve different analytes including eleven VOC's and water were used to characterize the MOFs. Microcantilever sensors were shown to be durable, reliable and stable in long term testing despite being subjected to many different analytes. MOF coatings proved flexible, durable, stable and reversible. This work will show a promising new technology for a next generation gas sensor.

To increase productivity, application developers are using tools that allow them to create higher quality applications faster. One such set of tools, open-source frameworks, allows application developers to reuse software artifacts and should increase application quality. However, given the vast number of open-source frameworks available, users must be able to differentiate among frameworks and select the one best suited for them. In this study, we expand the taxonomy of open-source frameworks and analyze the impact of the framework's characteristics, technical quality, and social pressure on perceived usefulness and continued framework usage intention. Our findings suggest that understandability and flexibility have a significant impact on perceived ease of use, while perceived usefulness is mainly determined by flexibility and efficiency. Our research can be used to understand what influences developers to continue using frameworks and to improve framework development. / viii, 129 leaves : ill. ; 29 cm

The topological diversity of lithium-boron imidazolates LiB(imid)4 was studied by combining topological enumeration and ab initio DFT calculations. The structures based on zeolitic rho, gme and fau nets are shown to be stable and have high total hydrogen uptake (6.9–7.8 wt.%) comparable with that of MOF-177. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

The purpose of this research is to develop a comprehensive, IS assessment framework using existing IS assessment theory as a base and incorporating suggestions from other disciplines. To validate the framework and to begin the investigation of current IS assessment practice, a survey instrument was developed. A small group of subject matter experts evaluated and improved the instrument. The instrument was further evaluated using a small sample of IS representatives. Results of this research include a reexamination of the IS function measurement problem using new frameworks of analyses yielding (a) guidance for the IS manager or executive on which IS measures might best fit their organization, (b) a further verification of the important measures most widely used by IS executives, (c) a comprehensive, theoretically-derived, IS assessment framework, and by (d) the enhancement of IS assessment theory by incorporating ideas from actual practice. The body of knowledge gains a comprehensive, IS assessment framework that can be further tested for usefulness and applicability. Future research is recommended to substantiate and improve on these findings. Chapter 2 is a complete survey of prior research, subdivided by relevant literature divisions, such as organizational effectiveness, quality management, and IS assessment. Chapter 3 includes development of and support for the research questions, IS assessment framework, and the research model. Chapter 4 describes how the research was conducted. It includes a brief justification for the research approach, a description of how the framework was evaluated, a description of how the survey instrument was developed and evaluated, a description of the participants and how they were selected, a synopsis of the data collection procedures, a brief description of follow-up procedures, and a summary. Chapter 5 presents the results of the research. Chapter 6 is a summary and conclusion of the research. Finally, included in the appendices are definitions of terms, and copies of the original and improved survey instruments.

Metal–organic frameworks, or MOFs, have emerged as a new class of porous materials made by linking metal and organic units. The easy preparation, structural and functional tunability, ultrahigh porosity, and enormous surface areas of MOFs have led to them becoming one of the fastest growing fields in chemistry. MOFs have potential applications in numerous areas such as clean energy, adsorption and separation processes, biomedicine, and sensing. One of the most promising areas of research with MOFs is heterogeneous catalysis. This thesis describes the design and synthesis of new, carboxylate-based MOFs for use as catalysts. These materials have been characterized using diffraction, spectroscopy, adsorption, and imaging techniques. The thesis has focused on preparing highly-stable MOFs for catalysis, using post-synthetic methods to modify the properties of these crystals, and applying a combination of characterization techniques to probe these complex materials. In the first part of this thesis, several new vanadium MOFs have been presented. The synthesis of MIL-88B(V), MIL-101(V), and MIL-47 were studied using ex situ techniques to gain insight into the synthesis–structure relationships. The properties of these materials have also been studied. In the second part, the use of MOFs as supports for metallic nanoparticles has been investigated. These materials, Pd@MIL-101–NH2(Cr) and Pd@MIL-88B–NH2(Cr), were used as catalysts for Suzuki–Miyaura and oxidation reactions, respectively. The effect of the base on the catalytic activity, crystallinity, porosity, and palladium distribution of Pd@MIL-101–NH2(Cr) was studied. In the final part, the introduction of transition-metal complexes into MOFs through different synthesis routes has been described. A ruthenium complex was grafted onto an aluminium MOF, MOF-253, and an iridium metallolinker was introduced into a zirconium MOF, UiO-68–2CH3. These materials were used as catalysts for alcohol oxidation and allylic alcohol isomerization, respectively. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 5: Manuscript.</p>

Context of this research: The construction industry has a history of client dissatisfaction in the UK. In response, framework agreements have been developed to create relationships between suppliers and clients in order to improve project performance. This research aims to assess whether use of framework agreements can result in significant improvement for performance outcomes without a significant increase in costs when compared with traditional discrete methods, and if so, develop a procurement performance model for realisation and continuous improvement in performance. Research methodology: A literal review of UK Government reports with economic and performance management theories precede a case study set within Hampshire County Council, a major public sector authority, allowing analysis of data from 164 highway maintenance projects by independent samples t-tests. Projects are divided into discrete and framework groups using critical success factors to measure performance differences. In addition to project outcomes, a review of economic performance was undertaken to advance a current ‘gap in professional knowledge’ concerning cost effectiveness of framework agreements. A performance management model is proposed representing impact of operational measures and sociological behaviour factors on suppliers’ performance, tested by qualitative views of experienced practitioners collected through a questionnaire survey and in-depth interviews. Key findings: Independent-samples t-tests proved that there were significant improvements in performance with use of framework agreements, but that no significant additional costs were incurred. Factor analysis and central tendency statistics from questionnaires and node values from interview transcripts confirmed long-term relationships, financial and non–financial incentives and stronger communication were sociological behaviour factors driving performance for framework agreements. Conclusions from the evidence and findings: As framework agreements can achieve significant performance improvements without a significant increase in costs, this study supports use of framework agreements for Hampshire County Council and professional practice. Value of this research is recognised by both central government and case study organisation alike. In respect of the latter context, case study findings have been included within a regional framework for use by South East authorities until 2016. It is recommended further studies should be conducted on civil and building projects in wider public and private sectors so that construction clients can make informed decisions based upon generalised findings.

Framework materials that contain molecular bridging ligands between metal nodes—as seen in coordination polymers—not only give rise to enhanced structural diversity, but also to a range of useful and unusual mechanical properties. This thesis demonstrates the general structure–property relationships that are developed for coordination polymers in order to enable prediction and design of their mechanical properties, and hence structural flexibility. Variable-temperature and -pressure diffraction experiments are employed for the determination of their mechanical properties, namely by calculating thermal expansion and compressibility coefficients. The anomalous and varied mechanical responses observed are rationalised by the important structural features, or the so-called mechanical building units (XBUs), of the coordination polymers. The XBUs are considered within the setting of framework topology, geometry, and composition in order to establish general design principles for targeting different degrees of flexibility within coordination polymers. The XBUs are identified first in silver(I) 2-methylimidazolate, Ag(mim), a framework which is comprised of structural motifs of varying strength, namely argentophilic interactions, hinge points and metal–ligand bonding. The anomalous mechanical responses in Ag(mim) are shown to be rationalised entirely by the XBUs present in the structure. The XBU abstraction is then applied to a range of other coordination polymers and shown to correspond directly with the anomalous responses known in these materials. The metal–ligand–metal linker XBU is investigated further in both cadmium imidazolate, Cd(im)₂, and zinc cyanide, Zn(CN)₂. Here, the linker chemistries are completely different between the two frameworks, but the diamondoid arrangement of the linkers, and thus the topology, is the same. The structural responses of the two frameworks are examined to unravel the extent of topology- and chemistry-driven mechanics. It is found that the topology dominates the atomic displacements of both frameworks, indicating the existence of common soft-mode dynamics which are likely to extend to other coordination polymers with the same topology. The three-dimensional framework-hinging XBUs in zinc isonicotinate, Zn(ISN)₂, and indium deuterium terephthalate, InD(BDC)₂, are considered next. These frameworks have the same topology but contrasting framework geometries, evident from the differing c/a-lattice parameter ratios. In this case, a geometric formalism is derived which can predict the direction of framework mechanical anisotropy in Zn(ISN)₂ and InD(BDC)₂ and other uniaxial coordination polymers. Finally, a family of ABX₃-type transition metal(II) formates are investigated, where both the B-site and A-site cations are varied. The chemical modifications give rise to variations in B- or A-site cation sizes, which are found to correlate with the magnitude of mechanical responses. These structure–mechanical property relationships—based upon framework topology, geometry and composition—are presented in separate chapters, and in each case generalised so that they can be applied to a range of coordination polymers. Hence the design principles determined here can provide the materials science community with an intuition on the type and magnitude of responses possible in these materials under different external stimuli.

Conventionally, crystalline microporous materials such as zeolites and metal-organic frameworks (MOFs) are synthesized through the hydrothermal route or the trial-and-error approach. Other synthetic strategies may lead to the synthesis of microporous materials with new architectures or interesting properties. The general aim of this thesis is to investigate some new synthetic routes towards crystalline microporous materials. A top-down and post-synthesis method is reported in Chapter 4. Some zeolites are built up by layers and double-4-ring pillars. Germanium is preferentially located in the double-4-ring sites of a zeolite framework and is hydrolytically unstable. The idea of the top-down method is to disassemble these zeolites to the layer structures by dissolving the Ge-containing pillars and reassemble them to a new framework. This method is applied to the germanosilicate IWW and ITH zeolites for the first time. The effects of framework chemical compositions, Ge distributions and disassembling conditions on the top-down treatment process are investigated. The products obtained from the top-down treatment are characterised. An ionic liquid assisted strategy for the synthesis of zeolites is described in Chapter 5. The ionic liquid assisted strategy is a solvent free reaction. The raw materials are transformed to zeolites through a solid state reaction. The ionic liquids are first used as structure-directing agents (SDAs) in this solvent free reaction to replace the expensive quaternary ammonium hydroxide. A TON zeolite is synthesized using 1-ethyl-3-methylimidazolium bromide as the SDA. Moreover, the ionic liquid assisted strategy is considered as a “green chemistry” synthetic route due to the high yield of the zeolites and the minor production of waste water. Many aluminophosphates have been successfully synthesized through ionothermal routes. Most of them are synthesized using 1-alkyl-3-methylimidazolium based ionic liquids. A new ionic liquid, 1-(2-hydroxyl-ethyl)-3-methylimidazolium chloride ([HOEmim]Cl), is prepared and used for the ionothermal synthesis of aluminophosphate materials. A zeolite analogue with the CHA framework has been synthesized. At high synthetic temperatures, the products are large single crystals. The structures of the framework and the SDA are investigated by single crystal diffraction and other characterisation methods. Flexible MOF materials are usually synthesized by a trial-and-error approach. Recently a flexible MOF compound was synthesized using 5-sulfoisophthalic acid (SIP) as the ligand. It was proposed the sulfonate is weakly coordinated to the metal, which brings flexibility to the compound, and the carboxylate groups keep the framework intact. 2-sulfoterephthalic acid (STP) which also contains one sulfonate group and two carboxylate groups is believed to be an alternative ligand for the targeted synthesis of flexible MOFs. In Chapter 7, a MOF compound is synthesized using STP and 4, 4'-bipyridine (Bpy) as ligands to validate the proposed strategy can be generalized. Variable temperature single crystal diffraction analysis solves the structure and reveals a reversible structure transformation upon dehydration and rehydration.

Quel lien existe-t-il entre la formation des stratégies et le contexte institutionnel au sein duquel les stratèges opèrent? Pour tenter de répondre à cette question, ce travail doctoral met en œuvre un design de recherche interprétativiste qui permet d'explorer les caractéristiques de la finance islamique avant d'analyser la façon dont les banques islamiques libanaises élaborent et mettent en œuvre leurs stratégies. L'étude révèle que les possibles institutionnels du champ naissant de la finance islamique restent ouverts et que les firmes qui y opèrent peuvent se positionner au sein d'amorces institutionnelles qui se distinguent par l'importance qu'elles accordent aux facteurs technique, religieux et socioéconomique ainsi que par la relation qu'elles prônent avec la finance dite conventionnelle. En adoptant la configuration qui leur semble la plus à même de faciliter la mise en œuvre de stratégies qui assurent leur pérennité, les organisations choisissent ainsi un ordre cognitif spécifique qui influence à la fois leur agir stratégique et l'ensemble des situations de gestions auxquelles elles peuvent être confrontées. Par la même occasion, elles participent à la diffusion d'un modèle institutionnel spécifique et contribuent, donc, indirectement à son institutionnalisation. C'est ainsi que le champ de la finance islamique est, non seulement, l'arène d'une « lutte » concurrentielle entre institutions financières islamiques mais aussi le théâtre d'un conflit symbolique qui oppose les futurs potentiels de la finance islamique et qui a pour enjeux la forme finale du champ ainsi que sa relation avec la finance dite conventionnelle. / How does the institutional context impact the formation of strategies? This PhD thesis tries to answer this question using an interpretative research design while utilizing Islamic finance as a field of study. It analyzes the methods used by Lebanese Islamic banks to set up and implement their strategies locally and abroad. The thesis reveals that the field of Islamic finance is still in a pre-institutionalization phase. It uncovers the parameters of three possible institutionalization paths according to the importance given to technical, religious or socioeconomic factors as well as the way the banks define their relationship to conventional finance. By choosing one of these options, Lebanese Islamic banks opt for a specific cognitive framework that influences their strategies and organizational behavior altogether. In turn, these firms also contribute to the diffusion of the principles underlying their choice and therefore, indirectly, to their institutionalization. Hence, instead of being just an arena for a traditional inter-firm competitive war, Islamic finance becomes the ground of a symbolic struggle that opposes the different potential futures of the field, and one that will shape the final form of the industry and its relationship with conventional finance.

The thesis explores possibilities of linking the symbolic frameworks and project method into a functional complex, which would enrich education. The reason of connection can be mainly found in strengthening the internal motivation of pupils and in bringing themes coming from the world of children into education as well.