Landslides are one of the most dangerous geological hazards. In the United States, landslides cause a damage of $ 3.5 billion and kill 25 to 50 people annually. Shallow landslides occurring near any transportation facilities (railways and highways) can cause economic loss and disturbance of services which lead to indirect economic loss. It also increases the maintenance cost of those facilities. Hence, facilities located near a shallow landslide prone area should be monitored so as to avoid any catastrophic damages. Soil moisture and movement of the soil mass are prime indicators of potential shallow slide movements. This assessment of wireless instruments considers a variety of devices ranging from devices for monitoring tilt and moisture at specific points in the soil mass to ground penetrating radar (GPR), which can give indications of moisture accumulation in soils over a wide spatial extent. For this assessment study, a low cost MEMS accelerometer was selected for measuring tilts and motions. And EC type soil moisture sensor was selected to measure soil moisture content of embankments. The instrumentation of railway embankments works effectively and cheaply when a suspected problem area has already been identified and monitoring is needed over a limited spatial extent. This makes the monitoring system highly localized which often fails to cover potentially new failure prone areas. It is not feasible to use this approach to monitor soil conditions along the entire alignment of the railway. Therefore, another approach, GPR, is defined and explained in this study. GPR measures the dielectric constant value for any given material including soils. In soils, the dielectric constant value depends on the volumetric amount of water content present in a soil. Due to moisture infiltration, there is a reduction in suction value on embankment which indicates a decrease in shear strength of slope. Therefore, a correlation between suction and dielectric constant value is formulated in this study using Complex Refractive index model/Time propagation (CRIM/TP) model for soils. To validate this theoretical correlation, a laboratory study was conducted on pure kaolinite and on normal soil. For pure kaolinite this correlation proves beneficial while, for other type of soil, the correlation was off due to the limitations in filter paper test to measure suction below 2.5pF.

Sol-gel process was utilized to produce organic/inorganic composite in this research, and the effect of mixing time¡]of polymer¡¦s and silica¡¦s precursor¡^ and coupling agent were investigated. To get low к materials was also the important objective. TMA, TGA, SEM, FT-IR, and RF impedance were used to investigate thermal properties, chemical bonding, morphology, and dielectric constant, respectively. The experiments showed that mixing time influence little to thermal stability but a lot to morphology and к. When mixing time was nearer to reaction time, the particle of silica was larger and the surface was flatter. The materials with coupling agent didn¡¦t show the same tendency as one without coupling agent. Regardless of coupling agent, it got larger к when mixing time was nearer to reaction time. Comparing with pure polymer, the modified materials got lower к. The lowest к got in this research was 2.36 which was lower than other materials.

Estuary is a complex region due to the mixing of fresh and sea water as well as the mixing of terrestrial and marine dissolved organic matters (DOM), so that the sorption behavior between hydrophobic organic compounds and dissolved organic matters is very complicated to estimate. By applying fluorescence quenching method, we investigated the influence of the mixing of binary dissolved organic matters from different sources on the binding constant (Kdoc) of pyrene and DOM. Results show that the kinetic of mixing of binary DOMs influences the binding constant, that means if there weren¡¦t enough standing time for mixing of binary DOMs, it would cause some bias in estimating the binding constants of pyrene and DOMs mixture. In this study, we also found that there exists a linear relationship on the binding constants between pyrene and DOMs mixture against mixing ratios. In addition, the mixing mechanism of SRNOM and LHA was dominated by diffusion process from the results of initial mixing efficiency. However, the diffusion process might not be the only mechanism of the mixing reaction of SHHA and LHA, other factors should be considered. Further investigations should be done to find out the dominating factors on the mixing of SHHA and LHA system in the future.

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.

Abstract As ULSI circuits are scaled down to deep submicron regime, interconnect delay becomes increasingly dominant over intrinsic gate delay. To reduce the RC delay time, many low dielectric constant materials have been developed. One of the most promising low-k materials is siloxane-based hydrogen silsesquioxane (HSQ) having the general formula (HSiO3/2)2n, n=2, 3, etc. available as Flowable Oxide (FOx). But low mechanical strength is the problem of HSQ. In order to modify the material composition and mechanical intensity of HSQ, a novel siloxane-based inorganic spin-on material Modified-HSQ has been developed for intermetal dielectric applications. In this thesis, the Intrinsic Properties of M-HSQ was investigated. And the effect of H2, O2 plasma treatment was investigated. Besides, In order to avoid the damage when remove the PR, to achieve small linewidth and reduce linewidth fluctuations. We employed E-Beam lithography to pattern the M-HSQ film. The leakage current of M-HSQ film by E-Beam curing is lower than film by conventional process.

As integrated circuits (ICs) are scaled down to deep submicron regime, interconnect delay becomes increasingly dominant over intrinsic gate delay. To solve the issue, two realistic methods are accepted popularly. On the one hand we use copper as the conductor for multilevel interconnects to decrease the resistance part of the RC delay. On the other hand we should reduce the coupling capacitance between the metal lines and this requires a low dielectric constant material. However, some difficulties come up in integrating low-k material with copper wires, including dielectric integrity and high diffusivity of copper ions. In order to prevent copper from penetrating into dielectric material under high electric fields and operation temperature, barrier dielectric have been developed to enhance resistance against copper drift. Silicon carbide (SixCy) with lower dielectric constant (k=4~5) is a promising barrier dielectric material to replace typically used silicon nitride (SixNy), (k~8). In this thesis, we will discuss the basic material properties of silicon carbide and the issues which will meet in process integration and actual working such as thermal cycles and operating under an electric field and a high temperature environment simultaneously. We investigated the conduction mechanism of the leakage current and tried to extract the physical parameters among it. In addition, the electrical properties of Silicon carbide at low temperature were also an important part of our research. Finally, we proposed some reasonable models to demonstrate the phenomenon and results we observed.

This thesis investigates the various techniques to achieve large time constants and the ultimate limitations therein. A novel circuit technique for the realization of large time constants for high pass corners in switched-capacitor filters is also proposed and compared with existing techniques. The switched-capacitor technique is insensitive to parasitic capacitances and is area efficient and it requires only two clock phases. The circuit is used to build a typical switched-capacitor front end with a gain of 10. The low pass corner is fixed at 200 Hz. The high pass corner is varied from 0.159Hz to 4 Hz and various performance parameters, such as power consumption, silicon area etc., are compared with conventional techniques and the advantages and disadvantages of each technique are demonstrated. The front-ends are fully differential and are chopper stabilized to protect against DC offsets and 1/f noise. The front-end is implemented in AMI0.6um technology with a supply voltage of 1.6V and all transistors operate in weak inversion with currents in the range of tens of nano-amperes.

In current years, searching for substitute energy such as the wind and ocean power of renewable energy is an important subject due to the petroleum shortage. The gear box is the key mechanism in the system of wind and ocean power. Moreover, the main function of the system is to generate electricity by speeding up the rotative velocity. However, the power of environment changes momentarily and makes the turbine a variable input. In order to improve the efficiency of generating electricity, it should get the constant input to keep the high quality of generating electricity. First of all, the study focuses on the gear box and synthesizes a constant speed mechanism of planetary gear train which degrees of freedom is two. In the mechanism, inputs are the variable speed turbine and a constant speed motor. When they input the mechanism, a constant speed output will be made to supply the generator. Secondly, it is necessary to set up the real object of the constant speed mechanism of planetary gear train. Finally, observing the real condition from the experiment to prove the theory is correct.

Abstract: This thesis is concerned with the acquisition of body signals using a sampling system. A typical application is the recording of the electrocardiogram (ECG). It is proposed to sample the input signal at different rates, depending on the momentary signal content. If the input signal has large voltage variation, it is sampled at a high rate. During periods of small variation, the signal is sampled at a lower frequency to save both memory and power. An analog controller to control the clock rate is proposed and implemented. The analog controller decides the sample frequency (high rate or low rate) depending on the input signal. The analysis of the proposed system is presented in this thesis. Furthermore, a working prototype is implemented using discrete components on a PCB. The measured results show a significant reduction in the average sample frequency and data rate of 50% and 35%, respectively. Finally, the critical analog circuit blocks of the system suitable for integration on chip are proposed and implemented in a 0.35£gm CMOS process. Measured results are reported to confirm the functionality of the blocks.

This thesis presents a single-stage high-power-factor electronic ballast for metal halide lamps. The proposed ballast integrates a buck-boost converter, a buck converter and a full-bridge inverter into a single power conversion circuit. The buck-boost converter is designed to be operated at the discontinuous conduction mode (DCM) with a constant duty ratio at a fixed switching frequency to provide a constant lamp power and to achieve a high power factor for a given ac input voltage. The full-bridge inverter supplies a square-wave current for the lamp at a low frequency the same as the line frequency to avoid acoustic resonance. For the universal input voltage ranged from 90 V to 264 V, the lamp remains at the rated power by controlling the duty-ratio of the buck converter. The circuit operation is analyzed in detail to derive the design equations. An electronic ballast for 70 W lamps is designed and tested. Computer simulations and experimental measurements are provided to verify that the proposed ballast has the merits of a nearly unity input power factor, a high efficiency greater than 82 % and can drive the lamp at a constant power.