The adhesive effects between abrasive particle and work on tool wear of the polishing process were considered in the study. Adhesive strength of the interfaces may affect wear rates of tool on the different adhesive way. Several sets of experiments were designed to reveal some phenomena about the wear rates of tool and work. There are variations in the adhesive of the interface causing different degree of tool wear for distinct kind of abrasive particle¡Bwork and tool¡¦s material. The experimental study demonstrated that the wear rate of tool was related to the adhesive strength between abrasive particle and work. Any change of the adhesive strength may significantly alter the wear rate of tool. An analytical study was done to examine the role played by the adhesive strength at the interfaces of abrasive particle on the wear rates of tool and work. It was derived from the law of force equilibrium and the principle of minimum potential energy. Tool wear was affected for polishing process by altering adhesive strength. The computer simulations indicated that an enhancement of adhesion between abrasive particle and work would always increase the wear rate at tool while the wear rate of work could be increased or decreased. To prove analytical study was reasonable by experimental study. Finally,the possible causes of observed phenomena and the limitations of the study were discussed.

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A novel sensing methodology using two-axis Hall-effect sensors is proposed, where the absolute positioning of a device atop any magnet matrix is possible. This methodology has the capability of micrometer-order positioning resolution as well as unrestricted translational and rotational range in planar 3-DOF (degree-of-freedom) motions, with potential capability of measuring all 6-DOF motions. This research presents the methodology and preliminary experimental results of 3-DOF planar motion measurements atop a Halbach magnet matrix using two sets of two-axis Hall-effect sensors. Analysis of the Halbach magnet matrix is presented to understand the generated magnetic field. The algorithm uses the Gaussian least squares differential correction (GLSDC) algorithm to estimate the relative position and orientation from the Hall-effect sensor measurements. A recursive discrete-time Kalman filter (DKF) is used in combination with the GLSDC to obtain optimal estimates of position and orientation, as well as additional estimates of velocity and angular velocity, which we can use to design a multivariable controller. The sensor and its algorithm is implemented to a magnetic levitation (maglev) stage positioned atop a Halbach magnet matrix. Preliminary experimental results show its position resolution capability of less than 10 µm and capable of sensing large rotations. Controllers were designed to close the control loop for the three planar degrees of freedom motion using the GLSDC outputs at a sampling frequency of 800 Hz on a Pentek 4284 digital signal processor (DSP). Calibration was done by comparing the laser interferometers’ and the GLSDC’s outputs to improve the positioning accuracy.

This thesis is to develop the power line carrier based identifier for the determination of customers served by each distribution transformer. The signal transmission characteristics of the power line carrier (PLC) over low voltage distribution lines and investigated. By executing the connectivity validation with the identifier developed, the accuracy of outage management system database can be enhanced for different types of customers (commercial /office buildings, commercial/ buildings, residential buildings) Various application functions such as contingency maintenance, transformer load management and customer outage management can be supported by outage management system (OMS) system more effecting. The mathematical models of 1£r2W, 1£r3W, 3£r3W and 3£r4W distribution have been developed by including the high frequency equivalent circuits of transformers, low voltage lines and customer loads in the computer simulation. The systems of signal coupling circuit, data processing, man machine interface have been designed with the embedded firmware for the PLC identifier. To demonstrate the effectiveness of the PLC identifier, a field test has been performed in Tainan District of Taipower. It is found that the customers served by each distribution transformer can be determined correctly with the PLC identifier developed.

InN thin films were grown on £^-LiAlO2 (100) by plasma-assisted molecular-beam epitaxy (PAMBE). Structural properties were investigated by reflective high-energy electron diffraction (RHEED), x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). XRD measurements showed that the crystal orientation of InN films was non-polar m-plane (11 ¡Â00). In addition, from SEM images, a striped morphology was observed along [112 ¡Â0]. Optical properties were characterized by photoluminescence (PL) spectroscopy, cathodoluminescence (CL) spectroscopy and micro-Raman scattering. Both CL/PL results revealed that InN films have a luminescence-emission peak-energy of about 0.65 eV. Carrier concentration had been determined by Hall measurements.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 84-85). Also available on the Internet.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 210-212).

Thesis (M.S.) in Teaching--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 83-86).