Abstract A novel process of combining electrokinetic remediation and nano-sized iron wall was used for studying its effectiveness of treating nitrate-containing soil. Nitrates and nitrites are commonly found in surface water and groundwater. These substances, in general, could pose a threat to both organisms in the water bodies and human health. Traditionally, nitrogen oxides in various water bodies are treated by biological denitrification processes. However, it would take a longer time to yield a satisfactory result as compared with physicochemical processes. In recent years, permeable reactive barriers (PRBs) using zero-valent iron have been successfully used for degradation of various compounds including nitrates. Electrokinetic processing (EK) also is considered as an effective in-situ technology for removing both inorganic and organic substances from the treatment zone. In this work, the synthesized nano-scale iron particles were incorporated into a PRB, which was further combined with EK to form a novel process for the degradation of nitrates. Various operating parameters were studied in this work. The nano-sized iron particles were determined to be ranging from 50-80nm in size and having specific surface area of 37.83m2. The isoelctric point of these nanoparticles was found to be at pH 7.3. Experimental results have shown that the best location of the iron wall was 5cm from the anode reservoir. Also, the optimal treatment time would be six days in this study. The treatment efficiency was found to increase with increasing dose of nano-sized iron particles in the PRB. Operating with the polarity reverse would slightly increase the overall treatment efficiency as compared with the case of no polarity reverse (92.38% versus 88.34%). An electric gradient of 1.5V/cm was determined to be the optimal electric field strength in this study. In this work, it was also found that 2.5g nano-scale iron particles outperformed 20g micro-scale iron particles (75-150µm) in terms of nitrate degradation. In a study of using an extended treatment time up to 20 days, the black colored iron wall would fade away becoming a rusty plume toward the cathode as the treatment time elapsed. Furthermore, the Fe2+ concentration was elevated throughout the soil column after the 20-day treatment. Therefore, it is evident that nano-sized iron particles would migrate when they are subjected to EK. Based on the research findings obtained, the novel process employed in this study was found to be an effective one for in-situ treatment of nitrate-containing soil.

The work aims to manufacture AS-4/PEEK APC-2 nano-composite laminates first. We used the prepreg form of AS-4 Graphite/PEEK laminae to make APC-2 laminates of 2 mm thick with two lay-ups of cross-ply and quasi-isotropic totally 16 plies by a hot press via the modified diaphragm curing. The nano-particles SiO2 with the average diameter of 15¡Ó5 nm were uniformly spread in the specific interfaces of laminate. From mechanical testing it is found that the nanocomposite specimens of spreading 10 plies nanoparticles (3% by wt. of matrix) possesses the highest mechanical properties. we see that in cross-ply specimens the ultimate strength increases 10.91 % and stiffness 6.7 %; while in quasi-isotropic specimens the ultimate strength increases 12.48 % and stiffness 19.93 %. Second, repeat the tensile tests at 50, 75, 100, 125, 150¢J to receive respective stress-strain curve , strength and stiffness. At elevated temperatures the ultimate strength decreases slightly below 75¢J and the elastic modulus reduces slightly below 125¢J, however, both properties degrade highly at 150¢J ( Tg) for two layups generally. Finally, the constant stress amplitude tension-tension cyclic testing was conducted. It is found that both the stress-cycles (S-N) curves are very close below 104 cycles for cross-ply laminates w/wo nanoparticles, and the S-N curve of nano-laminate slightly bent down after 105 cycles. Whilst in quasi-isotropic laminates, the S-N curve of nano-laminate is always slightly below that of APC-2 laminate through the life.

The microstructure and electrochemical behavior of boron doped and undoped ultra thin diamond film electrodes have been studied in this work. The ultra thin diamond films are deposited on porous silicon (PSi) by microwave plasma chemical vapor deposition (MPCVD). In order to enlarge the surface area of diamond electrodes, the deposition of nano structured diamond thin films is performed only in a short time deposition under a negative bias, so that diamond nuclei grew from the tips of PSi nano structures and the thin film surface remained rough and nano fine structured. Diamond thin films were analyzed by Raman spectroscopy and SEM, and then fabricated to the electrode device. From SEM analysis, the morphology of diamond thin films on PSi reveals in the shape of nano rods diamond crystallites. The electro-chemical response was evaluated by performing cyclic voltammetry in the inorganic K4[Fe(CN)6] and a K2HPO4 buffer solution. Boron doped diamond thin film on porous silicon has demonstrated a high redoxidation current of cyclic voltammetry, which may be due to the rough surface providing more electrochemical surface area and more sp2 conducting bonds exposed on the surface.

Ti nano-films are deposited on a NaCl(001) single crystal substrate by ion beam sputtering from a Ti target, and then annealed. Ti crystallites on a NaCl(001) substrate with increase in the substrate temperature and annealing have the preferred orientation (1-101) and (0001).

¡@¡@Embedded systems often use several ways to emulate floating-point computation, due to the limitation of hardware resources and the performance/cost consideration. The first part of this thesis will discuss how systems without hardware support emulate floating point operation, and the performance difference between whether hardware floating-point units exists or not, and finally the performance evaluation between the usage of floating-point and fixed-point. In the mean time, we will also discuss the porting process of Nano-X fixed-point version to the Versatile PB/926EJ-S development board. ¡@¡@Due to the growing market demand and the big improvement of hardware, there are several 3D-display applications beginning to be presented to the public. In order to develop 3D programs, we need a standard API to reduce our development time. OpenGL~ES is a royalty-free, cross-platform API for full-function 2D and 3D graphics on embedded systems developed by The Khronos Group. The second part of this thesis will discuss the implementation of EGL---the interface between windowing system and the OpenGL~ES rendering API---and the GLUT (OpenGL Utility Toolkits)-like library, in order to make OpenGL programmers' life easier.

The existing researches on interface properties between heterology materials mainly focus on semiconductor-metal and dielectric materials, but little on organic-inorganic ones. In recent years, the nanometer scale phenomena of interfaces between organic-inorganic is gaining a lot of attentions and becoming new frontier regions of nano-related research. Since gold exhibits excellent optical, electrical and mechanical properties, which can be applied to nano-optics, mechanics and electronics. Therefore this study aims to investigate the deformation behavior of nanaoindentation using molecular dynamics simulation and nanoindentation experiments. The nano-effect of mechanical properties between the interface of gold and heterologous Polymethyl Methacrylate (PMMA) with different side groups; i.e., Isotactic-PMMA, Syndiotactic-PMMA and Atactic-PMMA, are explored, respectively. The molecular structures of those side groups of the different PMMAs are identified and characterized. Those PMMA isomer thin films are prepared using spin-coater to deposit the different side groups of PMMA upon Au thin film. Sputter technique is used to form gold thin film with different thickness. The morphology on the surface of samples is characterized by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The indenter equipment is applied to realize the interface mechanical properties. The time-dependent properties of viscoelastic materials in nanoscale are measured using continuous stiffness measurement (CSM) nanoindentation technique. The effects of displacement rates on the hardness and modulus behavior of PMMA-based are investigated by nanoindentation. The mechanical properties are correlated with the side groups of the PMMA. The hardness of the PMMA-based increases with the raising displacement rate of the Berkovich tip. On the other hand, the modulus of the variation PMMA-based with the varied displacement rate of the Berkovich tip is not significant. The nanoindentation test shows different constituents in nanocomposite systems with a stronger material properties of the interface region than the matrix in each material.

The aim of this study was to investigate the microstructure, microhardness and biocompatibility properties of nano hydroxyapatite (HA) doped with a constant yttrium (Y3+) and varying fluoride (F-) compositions. HA was synthesized via precipitation method and sintered at 1100&amp / #61616 / C for 1 hour. Increased densities were achieved upon Y3+ doping while F- doping led to a decrease in densities. For structural analysis, XRD, SEM and FTIR spectroscopy examinations were performed. No secondary phases were observed in XRD studies upon doping. Lattice parameters decreased due to substitutions of ions. In SEM analysis, addition of doping ions was observed to result in smaller grains. In FTIR analysis, in addition to the characteristic bands of HA, novel bands indicating the substitution of F- ions were observed in F- ion doped samples. The highest microhardness value was obtained for the sample doped with 2.5%Y3+, 1%F-. Increased F- ion contents resulted in decreased microhardness values. For biocompatibility evaluation, in vitro tests were applied to the materials. MTT assay was performed for Saos-2 cell proliferation analysis. Y3+ and F- ion incorporation was found to improve cell proliferation on HA discs. Cells were found to attach and proliferate on disc surfaces in SEM analysis. ALP assay showed differentiation of cells on the discs can be improved by doping HA with an optimum amount of F- ion. Dissolution tests in DMEM revealed that structural stability of HA was improved with F- ion incorporation. The material exhibiting optimum structural, mechanical and biocompatibility properties was HA doped with 2.5%Y3+, 1%F-.

In this thesis, the leakage-mechanism after O2-plasma treatments was investigated. And the mechanism is transformed from Schottky emission into ionic conduction due to moisture uptake after porous silica film undergoes O2 plasma ashing. Besides, CMP process can to recover the damaged films by removed the degraded parts. From the result, we know that O2 plasma causing the bulky damage. Finally, the resistance of metal penetration of O2 plasma treated POSG is performed by utilizing BTS test. It was found that the moisture uptake in POSG films assisting metals in ionization process. Then, the penetrated metal ions in POSG film causes the leaky characters degraded.

Synthetic diamond thin films have potential for fabricating high-temperature semiconducting and optical devices because of its extraordinary properties. In this work, a microwave plasma chemical vapor deposition system has been setup. A two-steps deposition process will be applied for the growth of boron-doped diamond on silicon and on porous silicon. The effects of temperature, microwave power and of doping concentration of B2O3 have been studied by varying the growth parameters. The doping source of B2O3 solved in C2H5OH is applied with carrying gas of Ar. To vary the concentration of boron with the flow of Ar is controlled mixing into a reaction gas of CH4 and H2 mixture. Polycrystalline diamond thin films are examined by Raman, XRD and FTIR. In the SEM photograph a nano-wires structure has been found for higher doping of B2O3. A higher temperature the growth rate of the boron-doped diamond films will increase and the shape of crystallites will tend to polycrystalline. The diamond growth is in multi steps and the mechanism of deposition will change when the boron-doped diamond film grows up to a critical thickness. In this work a smooth diamond film was successfully grown on porous silicon without the step of nucleation.

The fabrication characteristic of focused ion beam (FIB) for fused quartz was investigated. With the progress of nanotechnology, new technologies and devices are invented constantly. In nanofabrication, FIB has several advantages such as high material removal rate, high resolving power and direct fabrication in some selected areas without etching mask. Therefore, it had been studied in detail to fabricate nano-structures by FIB. In this study, we found out the effect of nano-machining by adjusting the parameters of FIB system such as: beam current, overlap, and dwell time. The fabricated features together with their surface morphology and profile were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). Results show that when beam current was smaller, overlap was 50% and dwell time was 10£gs could get best performance by FIB.