884 results for 1990, Doctoral

  • Synthesis and characterisation of poly(acrylic acid) microspheres containing β-cyclodextrin

    Bibby, David C. (1999)

    Doctoral thesis
    University of Otago

    xviii, 160 leaves :ill. ; 30 cm. Includes bibliographical references. "February 1999"

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  • Feeding the lambs : the influence of Sunday Schools in the socialization of children in Otago and Southland, 1848-1901

    Keen, David Stuart (1999)

    Doctoral thesis
    University of Otago

    xiv, 250 leaves :ill. ; 30 cm. Includes bibliographical references.

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  • The son enthroned in conflict : a socio-rhetorical interpretation of John 5.17-23

    Huie-Jolly, Mary R (1994)

    Doctoral thesis
    University of Otago

    xviii, 333 leaves ; 30 cm. Includes bibliographical references. University of Otago department: Theology

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  • Taxonomy and phylogeny of industrial solvent-producing clostridia

    Keis, Stefanie (1996)

    Doctoral thesis
    University of Otago

    xii, 314 leaves :ill. (some col.) ; 30 cm. Includes bibliographical references. "June 1996". Includes previously published material by the author. University of Otago department: Microbiology.

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  • Expectations and satisfaction in tourism : an exploratory study into measuring satisfaction

    Gnoth, Juergen (1994)

    Doctoral thesis
    University of Otago

    xi, 277 leaves :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Marketing.

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  • "Fouling the nest" : the conflict between the 'church party' and settler society during the New Zealand Wars, 1860-1865

    Grimshaw, Michael P (1999)

    Doctoral thesis
    University of Otago

    328 leaves ; 30 cm. Includes bibliographical references. University of Otago department: Theology and Religious Studies

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  • Construction of quality in early childhood centres

    Farquhar, Sarah-Eve (1993)

    Doctoral thesis
    University of Otago

    iv, 122 leaves :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Education. Includes bibliographical references.

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  • "Church state relations in New Zealand 1940-1990, with particular reference to the Presbyterian and Methodist churches"

    Evans, John Adsett (1992)

    Doctoral thesis
    University of Otago

    xv, 179, [10] leaves :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Theology

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  • An axial system of tonality applied to progressive tonality in the works of Gustav Mahler and nineteenth-century antecedents

    Downes, Graeme (1994)

    Doctoral thesis
    University of Otago

    ix, 308 leaves ; 30 cm. Includes bibliographical references. University of Otago department: Music.

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  • Aspects of the population biology and ecology of the New Zealand cancer crab, Cancer novaezelandiae (Jacquinot, 1853) :

    Chatterton, Thomas David (1990)

    Doctoral thesis
    University of Otago

    190 leaves :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Zoology

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  • An examination of East Polynesian population history

    Chapman, Patrick Maurice (1998)

    Doctoral thesis
    University of Otago

    xii, 252 p. :ill., maps ; 30 cm. Includes bibliographical references. "March 1998." University of Otago department: Anthropology.

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  • The efficiency of adaptive cluster sampling

    Brown, Jennifer A. (1996)

    Doctoral thesis
    University of Otago

    xiii, 197 leaves :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Mathematics and Statistics. "January 1996."

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  • Stuck in the middle or clued up on both? Language and identity among Korean, Dutch and Samoan immigrants in Dunedin

    Johri, Roopali (1998)

    Doctoral thesis
    University of Otago

    xiv, 332 p. :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Anthropology. "24 February 1998."

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  • Population biology, pre-settlement processes and recruitment in the New Zealand sea urchin, Evechinus chloroticus Valenciennes (Echinoidea: Echinometridae)

    Lamare, Miles David (1997)

    Doctoral thesis
    University of Otago

    xxi, 257 leaves :ill., maps ; 30 cm. Includes bibliographical references. "May 1997." University of Otago department: Marine Science.

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  • A hierarchy of symbols : Samoan religious symbolism in New Zealand

    Duncan, Betty Kathleen (1994)

    Doctoral thesis
    University of Otago

    viii, 263 leaves :ill. (some col.), col. map ; 30 cm. Includes bibliographical references. University of Otago department: Religious Studies

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  • Haematology and inflammation in infections of farmed red deer (Cervus elaphus)

    Cross, John Philip (1991)

    Doctoral thesis
    University of Otago

    xiii, 180, i, 39 leaves, [1] folded leaf :ill. (some col.) ; 30 cm. Includes bibliographical references. University of Otago department : Microbiology

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  • Health in late prehistoric Thailand

    Domett, Kathryn M. (1999)

    Doctoral thesis
    University of Otago

    xvii, 326 leaves :ill. (some col.), col. maps, form ; 30 cm. Includes bibliographical references.

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  • Wavefront estimation in astronomical imaging.

    Irwan, Roy (1999)

    Doctoral thesis
    University of Canterbury Library

    The challenge in building astronomical telescopes is to obtain the clearest possible image of a distant star, which should appear as a single point. Extended objects, such as galaxies and planets can be regarded as collections of points. However, turbulence in the atmosphere degrades any optical signal that passes through it. The optical effects of the atmospheric turbulence arise from random inhomogeneities in the temperature distribution of the atmosphere. As a consequence of these temperature inhomogeneities, the index of refraction distribution of the atmosphere is random. Plane waves striking the atmosphere from space objects acquire an aberration as they propagate through the atmosphere. The plane wave's surface of constant phase is no longer planar when intercepted by a,n a.stronornica.l telescope. The prnctica.l consequence of a.tmospheric turbulence is that resolution is generally limited by turbulence rather than by optical design and quality of a telescope. There are a number of approaches to solving this problem, ranging from an orbiting telescope (the Hubble Space Telescope), adaptive optics, and post detection processing. The latter approaches have applications to less expensive ground based telescopes and have been the subject of many years of research. Adaptive optics is a general term for optical components whose characteristics can be modified in real time so as to alter the phase of an incident optical wavefront. An adaptive optics system can be used to correct for atmospheric induced distortions. Before any corrections can be applied, however, some measurement must be made of the phase distortions. It is the aim of this study to estimate the degradation of the wavefronts phase. Two approaches to do so are presented. Firstly, through wavefront sensors, which many adaptive optics systems have been devised from. Among them the Shack-Hartmann sensor is the most commonly used. The sensor requires a subdivision of the receiving pupil by means of sub-apertures, wherein the lowestorder deformation of the wavefront phase is estimated. This linearizes the problem of phase retrieval to solving a linear system of equations. A new analysis is presented which differs from previously published work in the estimation of the noise inherent in the centroid calculation used in this sensor. This analysis is supported by computer simulations. Secondly, the nonlinear approach of phase retrieval is discussed. The problem becomes how to relate the phase and magnitude of the Fourier transform. It is thus necessary to estimate the phase distortion in the instrument solely from measurements made at the image plane of the telescope. The process of phase retrieval is then divided into two distinct steps. The expression for the covariance of the phase distortion using a Kolmogorov model for the turbulence is derived first. This covariance is then employed as part of a formal Bayesian estimate of the phase distortion. It is also shown that phase retrieval can be employed as a robust technique for estimating the wavefront distortion using a lenslet array. The results obtained compare favorably with the alternative approach of phase diversity. Furthermore, the introduction of prior information, in the form of statistical information of the distortion, is shown to considerably enhance the success of the phase retrieval especially for very low light levels. A comparative evaluation shows the superiority of phase retrieval to Shack-Hartmann sensing, only if the local maxima are overcome. The principal drawback of phase retrieval is the relatively long computing time required to find the solution when general-purposed computer is used.

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  • Ring laser dynamics.

    King, Benjamin Thomas (1999)

    Doctoral thesis
    University of Canterbury Library

    The departure of the behaviour of large ring laser gyros from the ideal is examined. A detailed description of the experimental operation of large ring lasers is provided along with several new innovations in equipment layout, data collection and especially in data reduction. The limits on gyro performance due to noise are investigated. A review of literature regarding the fundamental limit placed on gyro resolution is provided. This limit is due to spontaneous emission in the gain medium of the laser and it is demonstrated that our ring lasers approach this quantum limit. Two entirely independent methods for evaluating the quantum noise induced linewidth are demonstrated to agree well. One of the methods, which uses a second order autoregressive model, is able to make accurate linewidth estimates in sub-second gate times. A complex model is proposed which accounts for specific observed light scattering phenomena within a ring laser. This model is compared with dual beam data taken from C-I and is able to describe frequency shifts and waveform distortion accurately. The model also performs favourably when describing locking profiles for low rotation rates and externally induced perimeter modulation. When locked to an external signal the ring laser is found to be an extremely sensitive low frequency vibration detector. The commissioning of a very large (14 m perimeter) prototype ring laser gyro, GO, is described along with a comparison with the smaller ( 4 m perimeter) gyros C-I and C-II. This prototype has proven to be an invaluable testing ground for designs and techniques to be used on a proposed high precision 16 m perimeter gyro named the Grossring (G).

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  • Modelling studies of coiled-coil protein in wool fibre

    Gan, Kaiwan (1995)

    Doctoral thesis
    University of Canterbury Library

    A multiple regression analysis has established a non-linear relationship between the backbone dihedral angles and theca coordinates obtained from the X-ray crystal structures of fourteen proteins. The regression equations have been applied to predict specific dihedral angles of each residue in the backbone of twenty-four proteins. Overall this method (NLRDT) predicts values of ɸ and ψ within a ± 45° window of those found in the X-ray structure with an accuracy of 94% and 91% and within a ± 30° window of 88% and 81%. Two methods for the assignment of motif from Cα coordinates are reported. For the first method motif is assigned from the dihedral angles predicted using the regression equations. If the predicted dihedral angles of a residue fall in the range of -15° > -90° and -10° >ψ> -70°, the residue is assigned as in an α-helix; and in the range of -90° > -150° and 95° < 170° as in a β-sheet. By the second method motif of the ith residue is assigned from the distance Ci-1α to Ci+2α (v6) and torsional angle Ci-1α, Ciα, Ci+1α, Ci+2α (v13). If these values for a residue fall in the range v6 v13 > 0° the residue is assigned as in an α-helix. If the values are in a range V6 > 8.7 Å and ǀv13ǀ > 100° the residue is assigned as in a P-sheet. For the twenty four proteins 23.7% of the residues by the former method and 19.6% by the latter method are assigned differently from the PDB. A Monte Carlo Protein Building (MCPB) method to construct the backbone and Cβ atomic coordinates of twenty-four proteins from known Cα coordinates is reported. The method selects values of dihedral angles from either ± 30° windows of the dihedral angle calculated for that amino acid by the Non Linear Regression Distance Torsion (NLRDT) method or from ranges established from a statistical analysis of the relationship between dihedral angles of the backbone and Cα coordinates for a protein data base. The averaged coordinates from ten backbone models of a protein were used to define a mean structure that was refined by energy minimisation using the AMBER force field (GB/SA). By the latter method the average atomic deviation and r.m.s.d. of the backbone and Cβ atoms is between 0.14 Å and 0.32 Å (average 0.22 Å) and 0.22 Å and 0.61 Å (average 0.43 Å) respectively. A comparison with other methods is made. A model of nine proteins including side chain atoms have been built from the known Cα coordinates and amino acid sequences using a Monte Carlo Protein Building Annealing (MCPBA) method. The Cartesian coordinates for the side chain atoms were established with bond lengths and angles selected randomly from within ranges of values previously determined by analysis of fourteen protein crystal structures and with torsional angles randomly selected from -180° to 180°. A simulated annealing technique is used to generate some 300 structures with differing side chain conformations. The atomic coordinates of the backbone atoms are fixed during the simulated annealing process. The coordinates of the side-chain atoms of the 300 low energy conformations are averaged to obtain a mean structure which is minimisation with the Cα atoms constrained to their position in the X-ray structure using the OPLS/AMBER force field with the GB/SA water model. The r.m.s.d of the main-chain atoms (without Cβ) compared with the corresponding crystal structures is in the range 0.20 Å to 0.64 Å with a average value of 0.45 Å. The r.m.s.d of the side-chain atoms is from 1.72 Å to 2.71 Å with an average of 2.26 Å. The r.m.s.d of all atoms is from 1.19 Å to 1.99 Å with an average of 1.61 Å. The method is insensitive to random errors in the Cα positions and the computational requirement is modest. A full atomic model of 7c and 8c-1 coiled coil rod domain in wool protein has been established from the amino acid sequences using the MCPB/MCPBA method. For the particular knob-hole heptad repeat, for the single α-helix the rise per residue is 1.464 Å; the twist angle per residue 102.999°; the number of residues per turn is 3.524 and the pitch 5.171 Å. For the four coiled coil helical segments of the rod domain the pitch is in the range 124 Å to 192 Å (average 172 Å); the radius of the coiled coil varies between 5.24 Å to 5.92 Å; the average value of the radius is 5.56 Å; the average crossing angle of the helices in the coiled coil is 23.0°; the number of residues per major turn is 127.3 and there are 36.2 minor turns in a major turn. The interaction energy between the two α-helical chains in the coiled coil structure is evaluated from van der Waals non-bonded interactions, electrostatic and hydrogen bonding interactions. The optimum relationship of the α-helical chains to each other established the heptad repeat interaction; 34% of the leucine residues are located at the d position. Of the backbone hydrogen bonds in the protein a-helix between residues four apart, 18% have a distance between a donor NH nitrogen and acceptor carbonyl oxygen greater than 3.5 Å .The hydrogen bonds between the side chains of the two a-helices in the coiled coil structure are largely between Arg and Glu, Arg and Asp and Glu and Asp. The distances of the Cβ atoms of cysteine residues are > 4.5 Å. This distance is outside that required for formation of disulphide bonds. The interaction of charged residues with apolar, polar and charged residues in the a-a, a-d, d-d, and d-a heptad positions accounts for 70% of the interaction energy.

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