In last decade, there has been a tremendous progress in scanning probe microscopies, some of which have achieved atomic resolution. However, there still exist some problems which have to be solved before the instrument can be used as a metrological measurement tool. The object of the project introduced in this thesis was to develop a scanning force microscope of metrological capability with the aim of making significant improvement in scanning force microscopy from the viewpoint of instrumentation. A capacitance based force probe has been studied theoretically and experimentally with the main concern being its dynamic properties, characterized by squeeze air film damping, which are believed to have direct effects on the fidelity of measurement. The optimization of design is investigated so as to achieve the results of both high displacement sensitivity and force sensitivity. An x-y scanning stage has been designed and built, which consists of a two axis linear flexure system of motion amplifying mode machined from a single aluminium alloy block. The stage is driven by two piezo actuators with two capacitance sensors monitoring the actual position of the platform to form a closed loop control system. The design strategy is introduced and the performances and characteristics of two commonly used types of flexure translation mechanisms, leaf spring and notch hinge spring system, are analyzed. The finite element analysis method is employed in the analysis and design of translation mechanism. Finally, a metrological scanning force microscope has been constructed, combining a constant force probe system, an x-y scanning stage and a 3D coarse positioning mechanism into a metrological system. The performance of the instrument system has been systematically evaluated and its measuring capability investigated on the. specimens of various properties and features. The results from this first prototype of the instrument demonstrated a subnanometer resolution with comparable stability and repeatability in all three axes.

Identifying human suffering as a socio-political phenomenon challenging the well-being and development of individuals, this work argues that International Relations requires a re-evaluation of its political structures in light of the ends articulated within the Universal Declaration of Human Rights and its associated International Human Rights Regime. Noting the problem of being, the particular problem of modern cognitive epistemologies this work seeks to ground an alternative philosophical conception of the individual framed within an account of natural law morality. Distinguishing itself from the epistemology of the received view of Modernity, the morality of natural law frames an alternative account of agency, agents, and the community. In its pre-modern form, natural law accounts for both the theoretical and practical reasoning capacities of the agent noting the ontological equality of every individual similar to modern cosmopolitan assumptions. It distinguishes itself from these accounts noting the relativity, and not universal ends of moral deliberations reflected in the tradition of casuistry. Articulating a moral taxonomy reflecting the ends of ‘the good’ this methodology is at odds with the stability of static political structures. Consequently, the natural law community is able to sustain an account of political pluralism, developing the unique qualities and characteristics distinguishing each and every agent. The plurality of life paths, alongside the equality of being, is reflected in the common good, the institutional representation of the personal relationships sustaining and furthering the development of morality mirroring the well-being and development of the moral agent. Articulating the art of politics, the cumulative appraisal of these ideas reveals an objective account of being political. Endorsing ‘being human in common’, it further institutionalizes the relationships of being reflected in the synthesis of philia and agape relations accounting for a personal account of politics. Noting the influential nature of coordinated political action, reflected in an ethic of love, this objective interpretation synthesizes local knowledge and customs alongside the universality of ‘the good’ addressing the particular developmental needs of suffering agents. Culminating in an account of the politics of potential, a realistic appraisal of the ends of this account of being political is mindful that political change, both solitary and in common, reflects the equal capacity of the agent to do both good and evil. Consequently, the hope of the politics of potential distinguishes itself from modern interpretations of politics equally aware of both the positive and negative attributes of contemporary human nature affecting those agents endeavoring to embark on the task of international institutional design.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

No description available.

Methanotrophic bacteria convert methane to methanol using a methane monooxygenase enzyme (MMO). Two types of MMO exist: a membrane bound enzyme (PMMO) and a cytoplasmic enzyme (sMMO). A system for the site-directed mutagenesis of residues in the active site of sMMO has recently been developed that uses a sMMO-minus strain of Methylosinus trichosporium OB3b as the expression host (Smith et al., 2002. Appl. Environ. Microbiol. 68:5265-5273); this strain, designated Mutant F, was created by disrupting the mmoX gene by marker-exchange mutagenesis. In this study a Ms. trichosporium OB3b strain was created in which all the sMMO structural genes were deleted or disrupted. This mutant was designated Ms. trichosporium SMDM. The recombinant expression of sMMO was performed in Ms. trichosporium SMDM using the same sMMO expression plasmid used for Ms. trichosporium Mutant F. The effect of sMMO expression in the absence of the enigmatic mmoD gene was investigated. Preliminary results indicate that mmoD is required for active expression of sMMO. The sMMO genes from Methylocella silvestris BL2T were sequenced and conjugated into Ms. trichosporium SMDM on a broad host range plasmid. No expression of Methylocella silvestris BL2 T sMMO was detected in Ms. trichosporium SMDM. A new system for the mutagenesis of the Ms. trichosporium OB3b sMMO a-subunit was created. Chimaeric sMMO mutants were created by introducing gene sequence from the alkene monooxygenase enzyme of Rhodococcus corallin us into the mmoX. The chimaeric sMMO enzymes appeared to be unstable in Ms. trichosporium Mutant F. An attempt was made to improve the stability of sMMO mutants in Ms. trichosporium Mutant F by disrupting the gene encoding the Lon protease. The Ms. trichosporium OB3b Ion gene was cloned and sequenced and attempts were made to disrupt the Ms. trichosporium OB3b Ion by marker-exchange mutagenesis. A mutant was not obtained, suggesting that Lon may be essential for vegetative growth of Ms. trichosporium OB3b. The diversity of sMMO in several environmental samples was investigated using PCR. The objective was to isolate novel mmoX sequences from uncultivated methanotrophs that could be used to design sMMO mutagenesis experiments. New PCR primers targeting the mmoX were developed. The primers were used to generate libraries from a blanket bog peat (UK) and from cave water (Romania). A group of sequences that did not cluster with the mmoX of any cultivated methanotroph was obtained from the cave water. The use of a PCR independent approach to clone methanotroph genes from environmental samEles was also investigated. This was performed by developing a method to clone 1 C-DNA from a stable isotope probing experiment with 13CH4 into a BAC vector. A library of 2300 clones was generated. Greater than 95 % of plasmids analysed contained inserts, which ranged in size from approximately 10 - 30 kb. The library was screened for mxaF, mmoX and pmoA by colony hybridization. A clone (15 kb) containing pmoA was completely sequenced. Other genes encoding proteins with (potential) roles in methylotrophy were contained on the clone, includingpmoC, pmoB, folP, folK, mptG and moxF.

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This paper outlines the evolution of the logarithm from the days of Archimedes to the logarithm now used in modern mathematics. Each type of logarithm developed had its particular usefulness. The Archimedean logarithm helped astronomers by drastically shortening the time it took to multiply large numbers, while Napier’s logarithm could be used as a tool to solve velocity problems. With the discovery of the number e, the natural logarithm was developed. Due to the frequent use of e, many of the properties of logarithms were defined to work nicely for the natural logarithm to make calculations easier. This paper will explain the proofs and connections of such properties in a way that could be presented in a calculus class. / text

<p>As the need for and usage of biomaterials in medicine constantly increase, so do the requirements for increased biocompatibility and hemocompatibility. Initially in blood-biomaterial interactions, the surface of an implanted biomaterial is enclosed with adsorbed host proteins and the composition of the adsorbed protein layer depends mainly on the physical-chemical properties of the biomaterial. It is known that the adsorption of proteins on the biomaterial surface may be followed by conformational changes of the adsorbed proteins and subsequent activation of the complement system. For example, binding of complement component C1q to IgG and IgM associated with biomaterial surfaces mediates complement classical pathway activation. The aim of this degree project work was to prepare and evaluate IgG and IgM free sera with functional complement activity for complement activation studies. Further complement studies necessitated IgG and IgM free sera, since two novel polymers with different compositions needed evaluation regarding their ability to induce antibody-independent complement classical pathway activation. Initially, immunoglobulin deficient fetal bovine serum was evaluated regarding complement activity, but no detectable complement activation was present. Different methods for depleting human serum of IgG and IgM were instead utilized and evaluated. From the results, it can be concluded that a close to complete IgG-depletion of human serum is achievable with serum maintaining low but functional complement activity. None of the applied methods for IgM-depletion were however successful and necessitate further optimization and evaluation.</p>

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No description available.