by Chan Man-ng. / Thesis (M.Ph.)--Chinese University of Hong Kong. / Bibliography: l. 108.

長期以來，人們知道壁面受限湍流中的聚合物添加劑將顯著降低摩擦阻力，但是對聚合物在熱對流熱傳輸的影響還沒有太多研究。作為第一步，一項最近的工作[1]研究了在穩態邊界層流中熱量傳輸是怎樣被聚合物添加劑所影響的。在這項工作中[1]，聚合物是用Oldroyd-B模型來描述，這個模型允許聚合物無限伸展而沒有限制。 / 在這篇論文中，我們用一個更加真實的聚合物模型來研究聚合物在穩態邊界層流中對熱量傳輸的影響。我們採用FENE-P（有限擴展非線性彈性Peterlin）模型，在這個模型中，聚合物僅可以被伸展到一個最大的長度。聚合物的有限伸展性由參數L來衡量，它是聚合物最大長度與平衡長度的比例。基於該模型，我們發現，相對於與聚合物溶劑在底板處粘度相同的牛頓流體，熱量傳輸可以被提高或者被降低，這取決於聚合物不同的L值。而在不同的L值下，流場中底板的阻力始終加強。在早期的工作中，可以用一個隨位置改變的有效粘度來理解聚合物的效果。我們探討了聚合物的有效粘度和流速場是怎樣被聚合物改變的，以理解這個問題。我們也對熱量傳輸與不同參數的依賴關係進行了研究，這些參數包括威森博格數，普朗特數和聚合物對零剪切下溶劑粘度作出的貢獻的比例。 / It has long been known that friction drag will be reduced signicantly due to polymer additives in turbulent wall-bounded flows, but the effect of polymers on heat transport in thermal convection has not been studied much. As a rst step, a recent work [1] has studied how heat transport in a steady-state boundary layer flow might be influenced by the addition of polymers. In this work [1], polymers are modeled by the Oldroyd-B model, in which they can be extended innitely without a limit. / In this thesis, we study the effect of polymers on the heat transport in steady-state boundary layer flow using a more realistic model of polymers. We apply the FENE-P (nite extensible nonlinear elastic-Peterlin) model, in which the polymers can only be extended up to a maximum length. The nite extensibility of the polymers is measured by the parameter L, which is the ratio of the maximum length to the equilibrium one. Based on the model, we nd that compared to a Newtonian flow with the same viscosity as that of the polymer solution at the plate, heat transport can be enhanced or reduced depending on L. The fraction drag is always enhanced by the polymers for all different L. In the earlier work, the effect of the polymers has been understood to produce an effective viscosity that is position-dependent. We have explored the effective viscosity of the polymers and how the velocity eld is modied by the polymers to understand our results. We have also studied how the results depend on the different parameters, including Weissenberg number, Prandtl number and the ratio of polymer contribution to the total zero-shear viscosity. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Yiqu = 有限伸展的聚合物對邊界層流中熱量傳輸的改變 / 王異曲. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 68-69). / Abstracts also in Chinese. / Wang, Yiqu = You xian shen zhan de ju he wu dui bian jie ceng liu zhong re liang chuan shu de gai bian / Wang Yiqu. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Prandtl-Blasius boundary layer flow --- p.7 / Chapter 3 --- Earlier work with Oldroyd-B polymers --- p.13 / Chapter 4 --- Theoretical formulation of the problem with polymers of finite extensibility --- p.20 / Chapter 4.1 --- Equations of motion --- p.20 / Chapter 4.2 --- Quantities of interest --- p.30 / Chapter 5 --- Checking validity of fixed angle approximation --- p.34 / Chapter 6 --- Results and Discussion --- p.42 / Chapter 6.1 --- Calculations --- p.42 / Chapter 6.2 --- The effect on heat transport --- p.45 / Chapter 6.3 --- The effect on drag --- p.48 / Chapter 6.4 --- The velocity field due to polymers --- p.49 / Chapter 6.5 --- Effective viscosity --- p.55 / Chapter 6.6 --- Dependence on Weissenberg number --- p.58 / Chapter 6.7 --- Dependence on Prandtl number --- p.61 / Chapter 6.8 --- Dependence on the ratio of polymer contribution to the total zero-shear viscosity --- p.64 / Chapter 7 --- Conclusion --- p.66

Zhang, Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 55-60). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Aim of Research --- p.2 / Chapter 1.3 --- Thesis Organization --- p.3 / Chapter 2 --- Literature Review --- p.4 / Chapter 2.1 --- Carbon Nanotubes in MEMS Devices --- p.4 / Chapter 2.1.1 --- CNT Integration and CNT sensors --- p.4 / Chapter 2.1.2 --- Prior Work in CMNS --- p.6 / Chapter 2.2 --- Overview of Motion Sensors --- p.7 / Chapter 2.2.1 --- Technology Overview --- p.7 / Chapter 2.2.2 --- Categories and Working Principles --- p.9 / Chapter 2.2.3 --- Application --- p.13 / Chapter 2.3 --- Thermal Convective Motion Sensors --- p.14 / Chapter 2.3.1 --- Micro Thermal Flow Sensors --- p.15 / Chapter 2.3.2 --- Research on Thermal Convective Motion Sensors --- p.17 / Chapter 2.3.3 --- Working Principle and Performances --- p.20 / Chapter 3 --- Design and Setup --- p.25 / Chapter 3.1 --- Methodology --- p.25 / Chapter 3.1.1 --- Research Method --- p.25 / Chapter 3.1.2 --- Critical Questions --- p.26 / Chapter 3.2 --- Sensor Chip Design and Fabrication --- p.27 / Chapter 3.2.1 --- Sensor Chip Mask Design --- p.27 / Chapter 3.2.2 --- Fabrication of Sensor Chip --- p.29 / Chapter 3.3 --- Sensor Prototyping --- p.30 / Chapter 3.3.1 --- CNT Deposition --- p.30 / Chapter 3.3.2 --- Sensor Building --- p.32 / Chapter 3.4 --- Setup of Experiment --- p.34 / Chapter 3.4.1 --- Source and Measure --- p.34 / Chapter 3.4.2 --- Acceleration Production --- p.35 / Chapter 4 --- Experiments and Results --- p.39 / Chapter 4.1 --- Hypotheses Verification --- p.39 / Chapter 4.1.1 --- Thermal Detection Using CNT --- p.39 / Chapter 4.1.2 --- Local Heating & Sensing --- p.40 / Chapter 4.2 --- Tilting Test --- p.42 / Chapter 4.2.1 --- Test Result --- p.42 / Chapter 4.2.2 --- Result Discussions --- p.43 / Chapter 4.3 --- Vibration Test --- p.45 / Chapter 4.3.1 --- Test Result --- p.45 / Chapter 4.3.2 --- Result Discussions --- p.52 / Chapter 5 --- Conclusion --- p.53 / Bibliography --- p.55

Xiao, Peng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 76-78). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.iii / ACKNOWLEDGEMENTS --- p.iv / TABLE OF CONTENTS --- p.vi / LIST OF FIGURES --- p.viii / LIST OF TABLES --- p.xi / Chapter CHAPTER ONE --- INTRODUCTION --- p.1 / Chapter 1.1 --- The Thermal Characteristic of the CNT Heater --- p.1 / Chapter 1.2 --- CNT-Based Micro Bubble Generation in a Static Droplet of Water --- p.2 / Chapter 1.3 --- CNT-Based Micro Bubble Transportation in a Micro Channel --- p.4 / Chapter 1.4 --- CNT-Based Micro Bubble Stimulation by Pulsed Current --- p.4 / Chapter CHAPTER TWO --- THE THERMAL CHARACTERISTICS OF CARBON NANOTUBES --- p.6 / Chapter 2.1 --- Temperature Coefficient of Resistance (TCR) of Our Typical CNT Heater --- p.7 / Chapter 2.2 --- The Humidity Coefficient of the Resistance (HCR) for Our Typical CNT Heater --- p.13 / Chapter 2.3 --- The Conclusion of the CNT Heater's Thermal and Humidity Characteristics --- p.18 / Chapter CHAPTER THREE --- MICRO BUBBLE GENERATION WITH MICRO WATT POWER USING CARBON NANOTUBE HEATING ELEMENTS --- p.19 / Chapter 3.1 --- Micro Electrode Fabrication --- p.19 / Chapter 3.1.1 --- Methods for Metal Electrode Fabrication --- p.20 / Chapter 3.1.2 --- Advantages and Disadvantages of Two Micro Fabrication Methods --- p.22 / Chapter 3.1.3 --- The Fabrication of Micro Electrodes for Our CNT Heater --- p.24 / Chapter 3.1.4 --- The Mask Design for Metal Electrode Fabrication --- p.26 / Chapter 3.2 --- The Micro Bubble Generation Experimental Procedure --- p.28 / Chapter 3.2.1 --- Initial Analysis of the Experimental Device --- p.28 / Chapter 3.3 --- Theoretical Analysis of Bubble Generation Temperature on the CNT Heater --- p.31 / Chapter 3.3 --- The Analysis of the Micro Bubble Generation Experimental Results --- p.35 / Chapter 3.4 --- The Conclusion of Bubble Generation in a Static Droplet of Water --- p.44 / Chapter CHAPTER FOUR --- CARBON NANOTUBE-BASED MICRO BUBBLE GENERATION IN A MICRO CHANNEL WITH DYNAMIC FLUID --- p.45 / Chapter 4.1 --- Micro Channel Fabrication --- p.46 / Chapter 4.1.1 --- Rapid Prototyping --- p.46 / Chapter 4.1.2 --- PDMS Moulding --- p.47 / Chapter 4.1.3 --- Irreversible Sealing --- p.49 / Chapter 4.1.4 --- Mask Design --- p.50 / Chapter 4.2 --- Experimental Setup --- p.51 / Chapter 4.3 --- Experimental Procedure --- p.53 / Chapter 4.4 --- Experimental Results --- p.55 / Chapter 4.5 --- Conclusion for Bubble Generation in the Micro Channel with Dynamic Fluid --- p.59 / Chapter CHAPTER FIVE --- CNT-BASED MICRO BUBBLE STIMULATION BY PULSED CURRENT --- p.60 / Chapter 5.1 --- Attempt to Control the Micro Bubble Diameter --- p.61 / Chapter 5.2 --- The Pulsed Current for Micro Bubble Departure in the Micro Channel --- p.63 / Chapter 5.2.1 --- Manual Pulsed Current Stimulation for Micro Bubble Departure in the Micro Channel --- p.64 / Chapter 5.2.2 --- The Pulsed Current Circuit for Micro Bubble Departure in the Micro Channel --- p.67 / Chapter CHAPTER SIX --- FUTURE WORK AND SUMMARY --- p.70 / Chapter 6.1 --- Future Work for Micro Bubble Generation Projects --- p.70 / Chapter 6.1.1 --- The CNT-Based Micro Bubble Generation with Various Values of Input Current --- p.70 / Chapter 6.1.2 --- The CNT Heater in the Zig-Zag Micro Channel --- p.71 / Chapter 6.1.3 --- Summary --- p.72 / APPENDIX A --- p.73 / Fabrication Process --- p.73 / Chapter I. --- Micro Electrode Fabrication --- p.73 / Chapter II. --- Micro Channel Fabrication --- p.75 / BIBLIOGRAPHY --- p.76

The failure of integrated circuit due to Silicon fracture is one of the problems associated with the production of a semiconductor device. The thermal stresses, which result in die cracking, are for the most part induced during the cooling process after attaching the die with Gold-Silicon solder. Major factors for stress generation in material systems are commonly large temperature gradients and substantial difference in coefficients of thermal expansion.

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Graduation date: 2005

Pure aluminum deformed in torsion (shear) at elevated temperatures reaches a broad "peak" stress and then undergoes about a 17% decrease in flow stress with deformation to roughly 1-2 equivalent uniaxial strain. Beyond this strain the flow stress is approximately constant. The sources for this softening are unclear. The suggested basis includes texture softening, microstructural softening, and enhanced dynamic recovery. Experiments were performed where specimens were deformed in torsion to various strains within the softening regime followed by compression tests at ambient and elevated temperature. Analysis of the compressive yield strengths indicate that the softening is at least substantially explained by a decrease in the average Taylor factor due to the development of texture. / Graduation date: 2002