by Kim-chung Koon. / Chinese title: / Bibliography: leaves 108-112 / Thesis (M.Phil.)--Chinese University of Hong Kong, 1983

by Ong Chung Wo. / Bibliography: leaves 118-120 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1986

Ma Lai Ching = 利用熱壓法制備塊体非晶態Pd₄₀Ni₄₀P₂₀合金 / 馬勵貞. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 51). / Text in English; abstracts in English and Chinese. / Ma Lai Ching = Li yong re ya fa zhi bei kuai ti fei jing tai Pd₄₀Ni₄₀P₂₀ he jin / Ma Lizhen. / Acknowledgements --- p.i / Abstract --- p.ii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction to Metallic Glass --- p.1 / Chapter 1.2 --- Applications of Metallic Glass --- p.2 / Chapter 1.3 --- Solidification Process --- p.3 / Chapter 1.4 --- Some Production Methods of Bulk Glassy Alloys --- p.10 / Chapter 1.5 --- Another Production Methods: Powder Consolidation --- p.11 / Chapter 1.6 --- Flaws of the as-Compacted Materials --- p.16 / Chapter 1.7 --- A Solution --- p.17 / References --- p.20 / Figures --- p.22 / Chapter Chapter 2 --- Experimental --- p.31 / Chapter 2.1 --- Production of Pre-Compacted Bulk Metallic Glass --- p.31 / Chapter 2.2 --- Handling of Bulk Glass Before Compaction --- p.34 / Chapter 2.3 --- Compaction Process --- p.35 / Chapter 2.1 --- Sample Analysis --- p.37 / Figures --- p.40 / Chapter Chapter 3 --- Mechanism of fusion of bulk metallic glasses --- p.45 / Abstract --- p.45 / References --- p.51 / Table --- p.52 / Figures --- p.53

Ngai Hau Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references. / Text in English; abstract also in Chinese. / Ngai Hau Wai. / Acknowledgements --- p.ii / Abstract --- p.iii / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- History of nanomaterials --- p.1 / Chapter 1.2 --- Application and properties of nanomaterials --- p.2 / Chapter 1.3 --- Thermodynamic of a binary system --- p.4 / Chapter 1.4 --- Nucleation and growth --- p.5 / Chapter 1.5 --- Spinodal decomposition --- p.7 / References --- p.10 / Figures --- p.11 / Chapter Chapter 2: --- Experimental setup and techniques --- p.21 / Chapter 2.1 --- How to achieve high undercooling? --- p.21 / Chapter 2.2 --- Preliminary steps --- p.22 / Chapter 2.2.1 --- Preparation of dehydrated B203 --- p.22 / Chapter 2.2.2 --- Preparation of the apparatus --- p.23 / Chapter 2.2.3 --- Preparation of Ni2P --- p.23 / Chapter 2.2.4 --- Alloying --- p.23 / Chapter 2.3 --- Experiment --- p.24 / Chapter 2.3.1 --- Preparation of pure glass --- p.24 / Chapter 2.3.2 --- Anneal the glass pieces at different temperature for 30 minutes… --- p.24 / Chapter 2.4 --- Investigation --- p.25 / Chapter 2.4.1 --- Thermal Properties --- p.25 / Chapter 2.4.2 --- TEM observation --- p.25 / References --- p.27 / Figures --- p.28 / Chapter Chapter 3: --- Crystallization kinetics of amorphous nanostructured materials --- p.32 / Abstract --- p.32 / Chapter 3.1 --- Introduction --- p.33 / Chapter 3.2 --- Experimental --- p.34 / Chapter 3.3 --- Results and Discussion --- p.35 / References --- p.41 / Figures --- p.42

by Leung Ching Chuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaf 47). / Text in English; abstract also in Chinese. / by Leung Ching Chuen. / Acknowledgments --- p.ii / Abstract --- p.iii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Expansion of the Mesoscopic World --- p.2 / Chapter 1.2 --- Nanostructured Materials --- p.3 / Chapter 1.3 --- A New Age --- p.4 / Chapter 1.4 --- """Flaws"" of the New Age" --- p.5 / Chapter 1.5 --- Phase Transformation --- p.7 / Chapter 1.6 --- Nucleation and Growth --- p.8 / Chapter 1.7 --- Spinodal Decomposition --- p.11 / Chapter 1.8 --- Morphology Change during Spinodal Decomposition --- p.13 / References --- p.16 / Figures --- p.17 / Chapter Chapter 2 --- Experiment --- p.25 / Chapter 2.1 --- Experimental Preparations --- p.27 / Chapter 2.1.1 --- Fused Silica Tube Preparation --- p.27 / Chapter 2.1.2 --- Alloying --- p.27 / Chapter 2.2 --- Experimental Procedures --- p.28 / Chapter 2.2.1 --- Fluxing --- p.28 / Chapter 2.2.2 --- Undercooling --- p.29 / Chapter 2.3 --- Sample Analysis --- p.30 / Chapter 2.3.1 --- Surface Analysis --- p.30 / Chapter 2.3.2 --- Differential Scanning Calorimetry (DSC) --- p.30 / Chapter 2.3.3 --- Hardness Testing --- p.31 / Chapter 2.3.4 --- Optical Microscopy --- p.32 / Chapter 2.3.5 --- Scanning Electron Microscopy (SEM) --- p.32 / Chapter 2.3.6 --- Transmission Electron Microscopy (TEM) --- p.32 / Chapter 2.3.7 --- X-ray Powder Diffraction (XPD) --- p.33 / References --- p.34 / Figures --- p.35 / Chapter Chapter 3 --- Mechanism of Bulk Nanostructured Material Formation by Metastable Liquid State Spinodal Decomposition --- p.38 / Abstract --- p.39 / References --- p.47 / Figures --- p.48 / Chapter Chapter 4 --- Formation of Amorphous Nanostructured Material --- p.57 / Abstract --- p.58 / References --- p.66 / Figures --- p.67 / Chapter Chapter 5 --- Crystallization Kinetics of Amorphoous Nanostructured Alloy --- p.75 / Abstract --- p.76 / References --- p.85 / Figures --- p.86 / Chapter Chapter 6 --- Conclusion --- p.101

Hydrogenated amorphous silicon films subjected to KrF excimer laser irradiation with a profiled beam in air leads to the formation of microstructures. The main objective of this research was to perform a comprehensive study in understanding this material in three different aspects: thermal, electrical, and optical properties by experiment, SEM analysis and modelling. For the thermal interactions, analysis was carried out to investigate factors relating to the formation of the microstructures in a range of applied laser fluences from 93.8 to 443.8 mJ/cm2. The tallest microstructures were formed with average height from 1 to 3 ?m at laser fluence of 312.5 mJ/cm2. Investigation also include the effect of different applied laser fluence, different scanning schemes, the effect of the presence of 300 nm metal layer, and irradiation environment. Thermal modelling using COMSOL simulation software was used to simulate heat transfer during laser-material interaction and the results suggest a fair agreement with experimental findings. SEM and TEM reveal that the material formed was an oxynitride with embedded particles of crystalline silicon. In the electrical part, conductivity and field emission were the main tools to help elucidate the internal structure. Arrhenius plots acquired from conductivity measurements demonstrates a decrease in activation energy from 0.8957 eV from original sample to 0.3955 and 0.1727 eV for HE and LE sample respectively. Analysis also showed an agreement with Meyer Neldel rule for both samples. Observation made on the ratio of dark current to photogenerated current revealed the decrease from 59600 in original sample to 1.77 and 1.40 for HE and LE samples respectively. For the field emission properties, IE plots from samples were analysed using 170 ?m fixed gap structure, and lowest emission thresholds were achieved at 3 and 2.4 V/?m for HE and LE samples respectively. The results were fitted to a model of conducting particles in an insulating matrix offering a transport route to the surface. In the optical part, FTIR measurements were carried and analysis in IR absorbance profile within range of 550 to 2200 cm-1 demonstrates SiHx absorbance peaks at 640 cm-1, between 1980 to 2100 cm-1, and at 2095 cm-1. Hydrogen content was found to be decreased with the increase in applied laser fluence from 12 % in original sample to 4.2 and 1.5 % for HE and LE sample respectively. Measurements using UV-Vis between wavelengths of 200 to 1100 nm shows high absorbance up to 98% for laser process sample from 218.8 to 312.5 mJ/cm2. TR analysis demonstrated increasing absorbance properties at increasing incident angle. Raman spectroscopy showed an increase in the crystal fraction with laser fluence. The final analysis work in this thesis examines the material as a potential disordered photonic crystal and studies the propagation and localisation of light in ordered and disordered photonic crystal, modelled using COMSOL simulation software. This shows the transition from diffusive to localised propagation. A number of applications are suggested for this structured material. This is the first report of a new large area ‘black silicon’ material that has a number of interesting applications.

The amorphous state is becoming increasingly important in the pharmaceutical setting. Formulation of poorly water soluble drugs in the amorphous form enhances physicochemical properties of the drug, such as solubility and dissolution rate, which in turn may lead to an increased bioavailability. However, despite these advantages, many properties of the amorphous state are not yet understood and amorphous materials pose a challenge for structural analysis since they lack three dimensional long range order. Hence, compared to crystalline materials often little structural information can be gained using standard characterisation techniques. In this thesis, a range of analytical techniques and data analysis tools were used to characterise as well as quantify amorphous drugs and compare them to their crystalline counterparts. Apart from established characterisation techniques such as X-ray powder diffraction, microscopy, and differential scanning calorimetry, molecular-level characterisation was carried out using vibrational spectroscopies including infrared, near infrared, and Raman spectroscopy combined with multivariate analysis methods. To obtain deeper understanding of the structure of amorphous drugs and their corresponding crystalline forms novel approaches such as pair distribution function analysis of X-ray diffraction data and computational chemistry were employed. Three model drugs namely indomethacin, saquinavir, and fenofibrate were investigated in the scope of this thesis. For indomethacin differences between amorphous forms of indomethacin prepared by ball milling, spray drying, as well as melting and subsequent cooling were analysed using infrared, near infrared, and Raman spectroscopy in combination with principal component analysis. While all spectroscopic techniques were able to differentiate between the differently prepared samples, Raman spectroscopy proved to be most sensitive to small differences in the solid state of different samples. Consistent with the study of indomethacin, Raman spectroscopy combined with principal component analysis was the most sensitive analytical technique to detect structural changes induced by milling or heating saquinavir. In addition, pair distribution function transforms of the X-ray powder diffraction data significantly contributed to the understanding of differences in short-range and long-range order between differently treated saquinavir samples. A combination of vibrational spectroscopy, quantum mechanical calculations, and multivariate analysis proved suitable for physicochemical analysis of amorphous fenofibrate. The results of the study support the idea that non hydrogen bonded molecules such as fenofibrate are likely to exhibit random molecular orientations and conformations in the amorphous phase since the weak intermolecular interactions that occur between such molecules can easily be disrupted. A study of ternary mixtures of crystalline and amorphous forms of indomethacin showed that Raman and near-infrared spectroscopy in conjunction with PLS regression are well suited for quantification of the different solid-state forms simultaneously. It was found that near-infrared spectroscopy can be used to more accurately quantify the mixtures compared to Raman spectroscopy when fluorescing components, such as amorphous indomethacin, are present. Nevertheless quantification with Raman spectroscopy was still possible. Overall, the analytical methods used in this thesis were successfully employed for qualitative and quantitative analysis of amorphous drugs and their crystalline counterparts. It could be shown that it is beneficial to use a combination of different analytical techniques and data analysis tools since results are complementary and allow a more comprehensive description of the solid state.

A Persistent Node is a redundant distributed mechanism for storing a key/value pair reliably in a geographically local network. In this paper, I develop a method of establishing Persistent Nodes in an amorphous matrix. I address issues of construction, usage, atomicity guarantees and reliability in the face of stopping failures. Applications include routing, congestion control, and data storage in gigascale networks.

No description available.

The aim of this project is to find the optimum growth conditions for growing amorphous Zn1-x-yAlxSny (x=0.02 and 0.2) films with various dopents and high transmittance in visible range. By varying substrate temperatures, working pressures, RF powers and growth modes, amorphous Zn1-x-yAlxSny films with high transmittance were successfully grown at low and room temperatures. Grazing-incident small-angle X-ray diffraction data indicates that low temperature, high working pressure, low RF power and the short deposition period are the key for growing amorphous films in which adatoms on the surface of substrate do not have enough energy for migration and constructing a better crystal structure. As a result of this inadequate energy of adatoms, clusters of grains can be observed on the surface of films by the atomic force microscope. Amorphous Zn1-x-yAlxSny films possess crystalline short range order that opens up the optical and electronic bandgap. In terms of transmittance, a blue shift in the critical transmittance and a higher transmittance in IR range are observed. The high level doping of Al and Sn in ZnO films introduces crystal disordering in films and results in amorphous films even they were grown at room temperature. X-ray absorption near edge spectrum (XANES) discovers that the doped Sn behaves as tetra-valence ions for those Zn1-x-yAlxSny films with high oxygen deficiency. All amorphous films grown in this project exhibits a very low conductivity.