Filters
Availability
Publication Year
Resource Type
Faculty
School/Institute
Publication Search Results
Sort
Results per page
1 - 2 of 2
-
(2020)ThesisAs China becomes wealthier and more powerful, the giant is taking further steps toward expanding its interests and influence, as well as a pursuing a greater global role. This is most evident in the Southeast Asia region, and in Cambodia in particular. Over the past two decades, China’s influence in Cambodia has increased significantly, especially in the realms of political, economic and defence cooperation. The two countries raised their bilateral ties to a Comprehensive Partnership for Cooperation in April 2006 and upgraded this to a Comprehensive Strategic Partnership of Cooperation in 2010 – both are significant milestones. In recent years Beijing has become Cambodia’s most important foreign aid donor, its largest source of foreign direct investment, and one of its largest trading partners. China has also become the largest source of assistance to the Royal Cambodian Armed Forces. Cambodia has undeniably come under China’s economic and political influence and has become one of China’s closest international partners and diplomatic allies. However, China’s development approach in Cambodia conflicts with that of the traditional donors that have also played an important role in Cambodia’s national development since 1993. Because China’s policy of development assistance operates outside the traditional aid system, it is not clear if the consequences of China’s style of development actually supports governance in Cambodia. Also, the broader social problems confronted by the ordinary people in Cambodia arising from rapid economic growth are often related to Chinese aid and investment projects. Through an examination of how China’s foreign aid has contributed to sustainable development in Cambodia, this thesis demonstrates that the impact of Chinese development aid is mixed. As Cambodia’s largest economic benefactor, China has played a significantly large part in the foundation of economic growth in Cambodia. Economic support from China has helped Cambodia with its national development, especially in the infrastructure sector, and hence has contributed to sustainable development in Cambodia. However, the negative impacts from China’s foreign aid on local communities, the environment, and on the development of democracy, have gravely hindered the commitment of the Cambodian government and impeded the international community in strengthening sustainable development in Cambodia. This thesis investigates these questions through qualitative methods, including interviews, discourse analysis, participant observation and field visits to Chinese investment projects in Cambodia.
-
(2021)ThesisThe bubble column evaporator (BCE) is an effective thermal water treatment method based on the mass and heat transfer from the continuously generated heated gas bubbles to the aqueous solution in the BCE column. In this research project, helium has been chosen as the inlet gas to evaporate water from a 0.5 m NaCl solution in a BCE system. The enhanced evaporation efficiency and the reduced enthalpy of vaporization (△Hvap) achieved by helium sparging demonstrated the potential of using helium to improve the evaporation performance of the BCE, while reducing the energy cost. To further increase the working efficiency of the BCE, we added surfactants in the column solution, and the results show that the arrangement of the surfactant molecules on the interface of the bubbles can effectively increase the efficiency of water-vapour transfer into the bubbles. More water molecules can be drawn into the bubbles via the attraction by the hydrophilic heads facing the column solution side, while obstructing their return into the solution by the layer of hydrophobic tails coating the inside of the bubbles. The introduction of surfactants can therefore result in a “molecule diode effect”, apparently improving evaporation efficiency by enhancing the saturation of water molecules within the dry bubbles. The working mechanism of the helium sparge was then studied by contacting helium flow with the salt solution within a membrane contactor. The helium atoms can be sparged into the counter-flowing salt solution through the microscopic pores on the membrane surface. The electrical conductivity of the salt solution, before and after sparging helium flow, was measured and compared; with the increased conductivity demonstrating that helium sparge can effectively enhance the evaporation efficiency, by facilitating the disruption of hydrogen bonds in the water network. This observation corresponds with the experimental outcome that helium flow can result in a higher evaporation performance in the BCE process, compared with other gases at the same inlet temperature. Based on these laboratory results, the research on the BCE process has moved from the laboratory to a pilot plant. A small pilot plant based on the BCE process has been designed and constructed to treat different types of wastewaters, including synthetic seawater, synthetic sewage water and synthetic piggery effluent. The observed amount of evaporated water vapour for the column solutions demonstrated the potential of the BCE process to treat different types of wastewaters on a large scale. In addition, combustion gas was also tested as the inlet gas, for the first time, to treat 0.5 m NaCl solution in the BCE system. The evaporation efficiency increased by 37%, compared with air at the same inlet temperature, most likely due to the existence of water vapour contained in the combustion gas mixture, which increased the transfer of heat to evaporate the surrounding solution. The water quality analysis for the distilled water demonstrated the potential for using the BCE system to produce high-quality water for irrigation or drinking purposes, depending on the type of column solutions.