A qualitative phenomenological study incorporating Photovoice was conducted to gain insight into the lived experience of patients with end-stage heart failure (ESHF). Seven participants were recruited and in-depth open-ended interviews were conducted with all participants. Three of the seven informants also opted to take part in the Photovoice portion of the project. “Working to preserve a sense of self” emerged as the essence of living with ESHF and was supported by three themes: i) the work of managing a failing and unreliable body, ii) the work of choreographing daily living; and iii) the work of charting the final chapter of one’s life. The findings from this study provide healthcare professionals with empirically grounded information and insights about the needs and everyday challenges individuals living with ESHF experience, and how clinicians can best support them. Such information is essential in order to plan meaningful, holistic, evidence-based care for ESHF patients.

This paper discusses the origin of the notion of two-stage revolution in Japan and its development by a member of Japan’s communist party, Nosaka Sanzo. The Communist International stipulated the task of Japan’s two-stage revolution in 1927. In the following years Nosaka Sanzo creatively developed the connotation and the nature of the two-stage revolution in Japan based on his comprehension of the economic and political features of imperial Japan. I begin my narrative on how Nosaka came to understand the labor problem in Japan’s imperial economy in the 1910s, and continue by outlining how he developed this idea as a criticism of the Japanese empire from 1927 to 1945. The research will contribute to the understanding of the communist movement in imperial Japan. / Graduate

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Membrane processes have found increasing industrial applications worldwide. For membrane processes to deliver their desired performances and mitigate the effect of disturbances, automatic controllers must be installed. Before the installation of controllers, operability analysis is a crucial step to evaluate how well the processes can be controlled, and to determine how process design can be improved for better control. However, existing applications of operability analysis in membrane processes are limited. This thesis extends the application of operability analysis to a multiple-stage membrane process, exemplified by a detailed case study of a 12-stage industrial whey ultrafiltration (UF) process. Process dynamic models are determined to describe the transient behaviour of process performance caused by disturbances and long-term fouling. Steady-state nonlinear operability analysis is conducted to identify inherent limitations of the process. Using the process dynamic models, dynamic operability analysis is performed to determine the effects of dynamic behaviour on process and controller design. Steady-state operability analysis shows that the whey UF process is not able to mitigate the effects of high concentrations of true protein in the fresh whey feed. The ability of the process to mitigate the effects of disturbances is also adversely affected by long-term membrane fouling. Mid-run washing is therefore necessary to restore control performance after long periods of operation. Besides demonstrating the adverse effects of long-term membrane fouling on operability, dynamic operability analysis identifies the manipulated variables that can deliver the best control performance. It also indicates that control performance can be improved by installing equipment (e.g. buffer tanks) upstream of the process. Dynamic operability analysis shows that recycling of the retentate stream has a profound effect on the plant-wide dynamics and reduces significantly the achievable speed of process response under automatic control. However, retentate recycling is essential during operation to minimize membrane fouling. Although reducing the number of stages in the whey UF process can improve the achievable speed of process response under automatic control, process performance will fluctuate significantly from its desired level. A trade-off therefore exists between process performance and control performance that should be addressed during process and controller design.

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The gas dispersion characteristics in mechanical flotation cells have a significant effect on the overall flotation performance. Three major properties that can be measured in characterising the gas dispersion in a flotation cell are bubble size, gas hold-up, and superficial gas velocity. Another property that is equally important in flotation is bubble surface area flux which is calculated from bubble size and superficial gas velocity. Despite the importance of gas dispersion in flotation, not much work has been reported previously in this area. Moreover, the study of gas dispersion in flotation has typically considered only a few points in a flotation cell and the average values were assumed to represent the gas dispersion characteristics in the entire volume of the cell. It is known however, that the gas dispersion characteristics are not uniformly distributed in a mechanical flotation cell. This thesis seeks to understand better the gas dispersion characteristics in mechanical flotation cells with a view to optimisation, modelling, cell comparison and selection. The main aim of this thesis was to measure comprehensively the gas dispersion characteristics in a mechanical flotation cell, analyse the behaviour in the entire volume of the cell, and develop a methodology for modelling the gas dispersion characteristics in the whole volume of the cell as well as develop the models themselves. For this purpose, a fully instrumented 3 m³ glass rectangular flotation cell at the Julius Kruttschnitt Mineral Research Centre (JKMRC) at the University of Queensland was used. The cell was fitted with a Dorr-Oliver impeller-stator mechanism and was provided with facilities to change impeller speed and gas flow rate. Sensors to measure the gas dispersion characteristics were also acquired and modified. This cell could only be operated in a two-phase (air-water) system but the opportunity was taken to make some comparative measurements in an operating plant in a three-phase slurry to compare the gas dispersion characteristics in two and three-phase systems. The comprehensive measurements of the gas dispersion characteristics (i.e. bubble size, gas hold-up, and superficial gas velocity, with subsequent calculation of bubble surface area flux) throughout the entire volume of the 3 m³ rectangular flotation cell show that the properties do vary with distance from the impeller, the cell bottom, and the walls. Statistical analysis to test the homogeneity of the properties in the cell confirmed that the differences (variation with distance) were real. It was found that the gas dispersion was poor in the corners of a rectangular flotation cell. These corners are referred to as dead zones. It can be interpreted that in these zones, flotation is less effective compared to other zones in a cell. The results of mapping the gas dispersion characteristics throughout the entire volume of the flotation cell were used to determine the best location to measure gas dispersion characteristics in a flotation cell in order to represent the overall values. It was established that this location in a flotation cell is about halfway between the impeller and the wall, and halfway between the bottom of the flotation cell and the pulp-froth interface. Statistical analysis also showed that there is “quarter symmetry”, i.e. there is no significant difference between equivalent positions in different quarters in a horizontal plane. In any future work, therefore, measurements of the gas dispersion characteristics need only be made in one quarter, and symmetry in the rest of the cell can be assumed. Following from the statistical analysis that established quarter symmetry in the 3 m³ glass rectangular flotation cell, a methodology to model gas dispersion characteristics in the entire volume of a rectangular mechanical flotation cell was developed, based on an experimental design known as CCRD (central composite rotatable design) which then modified. Using the methodology, models to predict bubble size, gas hold-up, superficial gas velocity and bubble surface area flux in the entire volume of a rectangular flotation cell were developed as a function of air flow rate and impeller speed. The validity of the models was tested using a predictive (cross) validation method, from where it was concluded that the models were valid. These models were then used to analyse the gas dispersion characteristics in detail in the flotation cell, as a function of flow rate, impeller speed, and location in the cell. Finally, a comparison of gas dispersion characteristics in two and three-phase systems in flotation cells was made. Comprehensive measurements of gas dispersion characteristics were performed in a three-phase slurry in an industrial OK 38 m³ rectangular flotation cell at the PT Freeport Indonesia concentrator, and the results were compared to those measured previously in the two-phase system in the 3 m³ rectangular cell. It was found that the profiles of gas dispersion were generally similar in both cells but the magnitude of the gas dispersion properties differed between the two systems. The presence of solid particles had greater effect on the bubble size than on gas hold-up and superficial gas velocity.