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    Generalised diffusion equations for anomalous diffusion in polymer networks : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Physics, School of Natural Sciences, Massey University, Manawatu, New Zealand
    (Massey University, 2022) Cleland, Josiah David
    Fractional and generalised derivative equations have proven to be a powerful tool in the modelling of anomalous diffusion within complex fluids. The suitability of these equations arises from to their capacity to include memory effects prevalent in the fluid, as well as allowing for the inclusion of external forces and relevant boundary values. Fractional derivative equations may be derived from underlying continuous-time random-walk models, however, the fractional derivative equations (and their generalisations) are simpler to deal with. This thesis investigated the ability of fractional derivative equations (and their generalisations) to model long timescale anomalous diffusion phenomena observed in some visco-elastic polymer networks. Recent work has suggested that within certain physical polymer networks there is a tendency for internal stresses to continuously build and dissipate. This phenomenon manifests itself within recordings of probe-particle mean squared displacements at long time scales. The dynamic behaviour of these networks parallels behaviour observed in earthquakes, earning the phenomena the name gel or cyto quakes. This link suggests that statistical features involved in other stress driven events may provide insight into the modeling of gel quakes. Both temporal and spatial considerations relevant to these quaking systems will be outlined and modelled within this work.
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    Molecular diffusion as measured by pulsed field gradient nuclear magnetic resonance : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University
    (Massey University, 1982) Kissock, Jeremy Samuel Druce
    The work presented in this thesis may be conveniently divided into three sections. Firstly the development of a Carr-Purcell-Meiboom-Gill pulse sequence for use in the pulsed field gradient experiment in order to examine diffusion over long diffusion times is described. Secondly diffusion coefficients of both components of binary mixtures of methanol and benzene have been measured using pulsed field gradient fourier transform NMR. Results showed self-association to be dominant over AB association and a brief qualitative explanation of the reasons for this is given. In the third section, which is the major part of this thesis, diffusion coefficients of water in the caesium perfluoro-octanoate, water system have been determined at various weight fractions and temperatures by pulsed field gradient NMR. The liquid crystalline phases occuring within the system are the isotropic micellar solution, the nematic amphiphilic mesophase and the smetic lamellar mesophase. Water was found to pass through the system in an unrestricted and virtually unhindered manner. These results were discussed in terms of the known structures of the phases and with respect to possible permeation mechanisms. No definite conclusion as to the permeation mechanism is possible. The limitations in the use of surfactants as membrane models is discussed.
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    An examination of kaizen drift in Japanese genba : implications for business in the anglosphere : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Business and Administration at Massey University, Manawatu, New Zealand
    (Massey University, 2013) Macpherson, Wayne Gordon
    In attempting to decode the industrial competitive success of Japan, researchers in the Anglosphere have predominantly identified with the highly visible tools and methods of the quality management philosophy of kaizen. However, due to data collection methodologies and significant cross-cultural limitations kaizen appears to have been largely misinterpreted and misunderstood. This ‘gap’ has resulted in literature riddled with deterministic models of mechanical methodologies promoted to pursue business excellence. Further, there has been a plethora of attempts at transplanting Japan-centric tools and techniques, with little – if any – regard for the country’s individual and indigenous social characteristics. To deepen understanding of kaizen a phenomenological study was conducted in middle-to-large sized industrial companies in Japan to investigate Japanese workers’ perspectives of kaizen. Two parallel and complementary philosophies of the pursuit of business excellence were identified. The Japanese thread explored how Japanese workers acknowledge and exercise kaizen; and, the Anglosphere thread examined how workers in the Anglosphere attempt to adopt and practise kaizen. In the Japanese context, society is identified as being highly bounded with little opportunity for individual creativity. Many Japanese industrial organisations, being active kaizen environments, channel worker creativity and expressions of individuality into bounded environments, or kaizen audiences, providing a counter-point to social and cultural requirements. In addition to Japanese-style management, this has resulted in the production of tangible kaizen tools and methods, as easily identified by Anglosphere researchers and practitioners. The primary contribution to knowledge this research presents is the development of understanding of the utility of the kaizen phenomenon. Kaizen in industrial settings in Japan is found to be both culturally bounded and contextually dependent, and far beyond continuous improvement; differences in the perceptions of older and younger workers are seen to exist as kaizen drifts across generational boundaries; active programmes are maintained to ensure that kaizen remains embedded in both the individual and the organisation; and, the simplistic diffusion of kaizen to Anglosphere organisations is observed to be an unlikely guarantee to sustainable business excellence over the longer term, as it has in Japan. This research reports that the only likely viable means to sustainably diffuse kaizen in Anglosphere domains is for business leaders to return to square one and instil an implicit, comprehensive understanding and appreciation of kaizen; and, acquire and develop recipient-organisation-centric tools and methods. Such a new approach could provide practitioners in the Anglosphere the means to adopt and sustain kaizen thinking and practice, and a gateway to sustainable competitive advantage.
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    Some studies on diffusion in macromolecular solutions : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University
    (Massey University, 1980) Trotter, Craig
    The construction and performance of a Pulsed Field Gradient system for use with a commercial, high-resolution, Fourier-Transform NMR spectrometer is described. The self-diffusion coefficient of benzene as measured by the calibrated system is in agreement with the current literature value, within the overall experimental error of the system (±2%). The use of an external lock in conjunction with signal averaging facilitates the measurement of self-diffusion coefficients for solution components in small concentrations. During signal accumulations, the system exhibits freedom from the spin-echo phase and envelope instabilities mentioned as sources of error even in recent publications dealing with the Pulsed Field Gradient technique (e.g. von Meerwall et al., 1979). The ability of the system to investigate dilute solutions is demonstrated by measurements made on 0.5% (w/v) solutions of polystyrene in carbon tetrachloride. Homogeneity coils included in the NMR probe have allowed the self-diffusion coefficients of some single components in multi-component systems to be investigated, and results for the binary system butanol-benzene are presented. Polymer self-diffusion coefficients have been obtained for 110,000 molecular weight random-coil polystyrene in the solvents carbon tetrachloride, deuterated-chloroform and deuterated-toluene. The Pulsed Field Gradient NMR method was used for the measurements, and the polystyrene concentrations ranged from 0.5% (w/v) to 25% (w/v). For each solvent a concentration regime is found in which the de Gennes' polymer self-diffusion scaling law is obeyed; and the upper concentration limit at which this scaling law breaks down is defined. The self-diffusion coefficient of polystyrene in the solvent deutero-benzene has also been determined, and is shown to agree with Forced Rayleigh Scattering self-diffusion results for similar molecular weight polystyrenes in normal benzene. In contrast, values of the self-diffusion coefficient obtained for polystyrene random-coils by calculation from sedimentation data are shown to differ significantly from those directly determined. The mutual diffusion coefficients of the polystyrene solutions have been obtained from Quasi-Elastic Laser Light-Scattering experiments. These mutual diffusion coefficients do not approach the directly measured self-diffusion coefficients even at concentrations where the random-coils are on average well separated. It is proposed that migrating polymers must suffer transient entanglement effects over the experimental time scales employed in the diffusion measurements. Quasi-Elastic Laser Light-Scattering has also been used to measure the diffusion coefficient of polystyrene latex spheres in 0.01M and 0.001M sodium chloride. Experiments were conducted over the latex sphere concentration range 0.004% (w/v) to 4.46% (w/v), and several measurements were also made for low concentrations of latex spheres in triply distilled water. The diffusion coefficient was found to be ionic strength dependent over the entire concentration range studied. Solutions of polystyrene spheres at moderate concentrations exhibit the phenomenon of multiple scattering. The available literature on multiple scattering is reviewed and criteria adopted for the reliable interpretation of data collected during experiments on these solutions. The diffusion coefficients so obtained show substantial agreement with the mutual-diffusion coefficient results of Anderson et al., obtained by a capillary penetration technique. The conclusion reached in this section of the work is that Quasi-Elastic Laser Light-Scattering is able to provide a measure of the mutual diffusion coefficient in the presence of interactions between charged macromolecules. This conclusion is seen to be in accord with earlier laser light-scattering studies on solutions of the protein Bovine Serum Albumin, provided that a reassessment of available mutual diffusion data on these systems is undertaken.
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    Development and applications of a low-field portable NMR system : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physics at Massey University, Manawatu, New Zealand
    (Massey University, 2011) Ward, Robert L
    Nuclear magnetic resonance (NMR) is a phenomenon similar to MRI in which radio frequency signals are used to excite and manipulate atomic nuclei within a static magnetic field. Following excitation, the nuclei return to equilibrium, all the while offering valuable molecular level information pertaining to the sample. Within the last decade, the development of small and inexpensive NMR spectrometers and permanent magnet NMR sensors has been a significant focus within the NMR community. More recently, application scientists have sought practical applications for the new technologies. In this thesis, a prototype NMR apparatus consisting of a spectrometer and 3.2MHz permanent magnet sensor was extended to enable scientifc measurements. This involved developing radio frequency electronic circuitry for the spectrometer front-end, and electromagnetic noise shielding and temperature regulation for the magnetic sensor. Experimental results confirmed that repeatable measurements using the modified apparatus were indeed possible. The NMR apparatus was thereafter successfully used to study flow, diffusion and kiwifruit using several different experimental techniques. A significantly larger effort was then expended upon the study of T2 relaxation in pectin model systems using pH as the adjustable parameter. The fascinating experimental results were successfully interpreted and modeled across three pH zones in terms of a proton chemical exchange model and molecular conformational changes. In addition, it was found that pectin carboxyl de-protonation was significantly less than expected. Further experiments performed upon galacturonic acid monomers, dimers and trimers appeared to further illuminate the pectin results. Future experiments are planned. Also while studying pectin solutions, an unexpected pH-dependent water transverse relaxation behavior was observed at both 3.2MHz and 400MHz. The only references found in the literature were from a small publication almost 50 years ago, and a 2011 publication. Altogether, this thesis contributed to original knowledge in several ways: it showed how a low- eld apparatus and single-sided sensor could be improved and utilized for a variety of scientific measurements; it showed both experimentally and theoretically how T2 for pectin solutions change with pH; it revealed an unexpected de-protonation limit for pectin molecules; it revealed a T2 pH dependence for water.