In spite of the stablility (lack of reactivity) of diamond powder, I have developed a method for tethering alkyl chains and polymers to deuterium/hydrogen-terminated diamond. One method is through ether linkages via thermolysis of di-tert-amyl peroxide (DTAP). This reaction with DTAP has also been applied to grow polymers on the diamond surface. The other method is atom transfer radical polymerization (ATRP), which was applied to grow polystyrene at the surface of diamond. Both polystyrene-modified diamond and sulfonated polystyrene-modified diamond can be prepared by either method, and can be used for solid phase extraction. Diamond stationary phases are stable under basic conditions, which is not the case for silica-based stationary phases. Surface characterization was performed by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). While the main focus of my graduate research has been the surface modification of diamond, I also describe other projects on which I have worked. The use of radical-based processes for modifying diamond is related to a different radical-based synthesis of monolayers or polymers I performed by scribing silicon (Siscr). After preparation of homogeneous olefin-terminated monolayers on scribed silicon made from 1,9-decadiene and chemisorption of Grubbs' catalyst, ring-opening metathesis polymerization (ROMP) of norbornene was demonstrated. These surfaces were characterized by XPS and ToF-SIMS. I also investigated the extent of PDMS oligomers transfer onto different surfaces with a wide range of hydrophobicities, using an uninked, unpatterned PDMS stamp. The effect of surface free energy on PDMS transfer in microcontact printing was investigated and the relationship between the amount of PDMS in ToF-SIMS spectra and the surface tensions of initial surfaces was revealed. Therefore, PDMS transfer can be applied as a probe of surface free energies using ToF-SIMS, where PDMS preferentially transfers onto more hydrophilic surface features during stamping, with little transfer onto very hydrophobic surface features. In much of my thesis work, I performed multivariate analysis of my data, especially of my ToF-SIMS data. Such chemometrics methods include principle components analysis (PCA), partial least squares (PLS) cluster analysis, and multivariate curve resolution (MCR). I also applied these tools to analyze electrospray ionization (ESI) mass spectrometry data from a lipidomics study.

A haptic interface is a robotic force feedback device that provides a sense of touch to users of virtual reality simulations. This thesis presents a general method for the design optimization of parallel planar haptic devices based on maximizing the manipulability of the interface over its workspace. Manipulability is selected as the key design objective to ensure avoidance of singular configurations within the workspace and to maximize the interface's ability to generate feedback forces and torques in each direction in each handle location and orientation. The optimization approach developed in this thesis results in a set of candidate designs that are found by stepping the design parameters through the range of possible values, and testing the manipulability and other measures (including workspace area and space) at each location and orientation of the interface handle. To find the optimal design, a multi-objective approach is taken to generate a set of Pareto optimal designs. A smart Pareto filter is employed to yield a smaller set of designs representative of the full Pareto frontier. The most desirable design is chosen from this reduced set. The result is a general optimization method applicable to parallel haptic interfaces. The method is demonstrated on the design of a 3-RPR parallel planar interface.

A new approach of making ion trap mass analyzers was developed in which trapping fields are created in the space between two ceramic plates. Based on microfabrication technology, a series of independently-adjustable electrode rings is lithographically patterned on the facing surfaces of each ceramic plate. The trapping field can be modified or fine-tuned simply by changing the RF amplitude applied to each electrode ring. By adjusting the potential function applied to the plates, arbitrary trapping fields can be created using the same set of ceramic plates. Unlike conventional ion traps, the electrodes of planar ion traps have a non-equipotential surface, thus the electric field is independent of electrode geometry and can be optimized electronically. The simple geometry and open structure of planar ion traps address obstacles to miniaturization, such as fabrication tolerances, surface smoothness, electrode alignment, limited access for ionization or ion injection, and small trapping volume, thereby offering a great opportunity for a portable mass spectrometer device. Planar ion traps including the planar quadrupole ion trap and the coaxial ion trap have been designed and tested using this novel method. The planar quadrupole trap has demonstrated a mass range up to 180 Da (Th), with mass resolution typically between 400-700. We have also developed a novel ion trap in which both toroidal and quadrupolar trapping regions are created simultaneously between a set of plates. This "Coaxial Trap" allows trapping and mass analysis of ions in two different regions: ions can be trapped and mass analyzed in either the toroidal or quadrupolar regions, and transferred between these regions. Some simulation work based on the ion motion between two different trapping regions in the coaxial ion trap has been performed. Using a one-dimensional simulation method, ion motion was investigated to transfer ions between these two regions. The effect of the mutipole components in the radial field and axial field, amplitude and frequency of the primary RF and supplementary AC signal were studied to obtain high mass resolution in the axial direction and high transfer efficiency in the radial direction. In all these devices, the independent control of each patterned electrode element allows independent control of higher-order multipole fields. Fields can be optimized and changed electronically instead of physically as is done in conventional traps.

For a topological space X, the fundamental group can be topologized as a quotient of the path space with the compact-open topology. For one-dimensional or planar Peano continua, the fundamental group with this topology is a topological group if and only if it is semilocally simply connected. In particular, we demonstrate that the group operation is not continuous in this setting.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24177号 / 理博第4868号 / 新制||理||1697(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 北川 宏, 教授 有賀 哲也, 教授 吉村 一良 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Repairs and modifications were made to a flow velocity measurement system designed to measure a planar area of unsteady three component velocities in a single realization using a velocity measurement technique referred to as Doppler Global Velocimetry (DGV). Several hardware components in the system were modified and new hardware was added. Significant improvements were made to the procedures used in acquiring DGV data as well as the procedures used in reducing the acquired DGV data. Though hardware problems were encountered, successful iodine cell calibrations were acquired and attempts were made to acquire DGV velocity data from a calibration wheel and in the wake of a 6:1 prolate spheroid. These attempts were hampered by poor performance of the Nd:YAG laser and one of the digital cameras used in this research. While the magnitudes of the velocities acquired from the calibration wheel were noticeably higher than those calculated from the angular velocity and large fluctuations were present in these reduced velocities, the general trends measured by the VT DGV system matched those calculated from the angular velocity. The attempt to acquire flow field data in the wake of a 6:1 prolate spheroid model was unsuccessful due to insufficient seed particle density in the area where data were to be obtained. The results of this research indicate that while significant improvements have been made to the system, there are still some significant problems to overcome. / Master of Science

Ultrawideband (UWB) phased antenna arrays are critical to the success of future multi-functional communication, sensing, and countermeasure systems, which will utilize a few UWB phased arrays in place of multiple antennas on a platform. The success of this new systems approach relies in part on the ability to manufacture and assemble low-cost UWB phased arrays with excellent radiation characteristics.This dissertation presents the theory and design of a new class of UWB arrays that is based on unbalanced fed tightly-coupled horizontal dipoles over a ground plane. Practical implementation of this concept leads to two inexpensive wideband array topologies, the Banyan Tree Antenna (BTA) Array, and the Planar Ultrawideband Modular Antenna (PUMA) Array. The key challenge in designing unbalanced-fed tightly-coupled dipole arrays lies in the control of a common mode resonance that destroys UWB performance. This work introduces a novel feeding strategy that eliminates this resonance and results in wideband, wide-angle radiation. More importantly, the new feeding scheme is simple and intuitive, and can be implemented at low-cost in both vertically and planarly-integrated phased array architectures. Another desirable byproduct of this topology is the electrical and mechanical modularity of the aperture, which enables easy manufacturability and assembly. A theoretical framework is presented for the new phased array topologies, which is then applied to the design of innite BTA and PUMA arrays that achieve 4:1 and 5:1 bandwidths,respectively. A practical application of this technology is demonstrated through the full design, fabrication, and measurement of a 7.25-21GHz 16x16 dual-pol PUMA array prototype for SATCOM applications.

Metamaterials are a growing area of interest in the electromagnetics community due to their highly uncommon wave-material interaction characteristics, and they can be modeled using transmission line (TL) based networks. From verification of negative refraction to modeling more complex devices such as invisibility cloaks and field rotators, TL metamaterials offer a tangible solution to modeling novel devices in 1-D, 2-D, and 3-D structures. While currently available TL metamaterials allow for a predictable and easily manufactured network, the need for periodic, regular grids make current TL metamaterials sub-optimal for devices with curved boundaries or realization on curved surfaces. Our work presents the theory and application of TL metamaterials on irregular, nonperiodic grids for modeling 2-D electromagnetic phenomena in TE polarization, allowing for accuracy in curved device boundary modeling and significantly increased adaptability in potential application to curved surfaces. Based on an irregular grid obtained using an unstructured surface mesher, irregularly-shaped individual cells are related to local medium parameters to represent an overall device. The design method is validated using simple scattering problems with known analytical solutions and simulation data through lumped-element circuit- network simulations. The design process is then applied to more complex devices such as the Luneburg lens and field rotator. Capabilities and limitations of this technique are tested and explored. A microstrip based version of this method is subsequently developed and investigated using circuit and full-wave simulation data as well as experiment of a printed-circuit realization.

<p>This thesis reports work targeting the integration of Si light emitters with optical waveguides. Such integrated devices would find utility in a number of applications including telecommunications, optical interconnects, and biological and chemical sensors. Much research has been directed by others on how to improve the emission efficiency and achieve lasing in VLSI (very large scale integration) compatible sources. Here, the focus is on how such devices can be integrated with planar waveguides. Two enhancement techniques were selected for potential integration; defect engineering (DE), and Si nanocrystals (Si-nc) embedded in Si02• Defect engineered light emitting diodes (LEDs) made on silicon-on-insulator (SOI) and emitting at 1.1 μm were successfully demonstrated. In addition, surface photoluminescence from SOI was analyzed to account for interference from the SOI cavity. However, it was determined that the emission efficiency of defect engineered LEDs studied during the course of this work is below that which was reported previously, and that the fabrication procedure thus suffers from irreproducibility. Barring an enormous advancement in the DE technique, it is concluded that the emission efficiency is too small to make use of its integration potential. </p><p>A more successful approach was obtained from the Si-nc system fabricated using electron-cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD). Optically pumped edge emitting devices were designed, fabricated and characterized. The devices are comprised of Si-ncs emitting at 800 nm, integrated with slab silicon nitride waveguides. This work is the first report of edge emission from Si-ncs integrated with silicon nitride waveguides. Edge emission and waveguide properties were characterized in the ~850 nm emission band of the Si-ncs. The edge emission was well described as a propagating mode, attenuated primarily by the Si-nc film. Propagation losses of a typical air/Si-nc/SiNx/Si02 waveguide were measured to be 11 ± 2 dB/cm and 20 ± 2 dB/cm at 850 nm in the TE and TM polarizations respectively. A wavelength dependent loss of -0.14 ± 0.03 dB/(cm*nm) was found to exist in the material loss of Si-nc films. In addition, the Si-nc films were found to undergo a partially recoverable photo-induced degradation of PL efficiency during exposure to pump light. Processing techniques compatible with both high efficiency Si-nc and low loss silicon nitride were developed and described. A two-sectioned photonic device was also designed, fabricated and characterized. The device contained an optically pumped Si-nc emitting waveguide section integrated with a low loss silicon nitride slab waveguide. The potential for optically pumped Si-nc emitters integrated with silicon nitride photonic circuits thus appears promising.</p> / Thesis / Doctor of Philosophy (PhD)

Recent developments in autonomous underwater vehicles (AUV) have created the need for a low cost AUV that is comparable in class and payload capabilities to existing, commercially available, expensive and sub-optimal crafts. The Navy is active in research of autonomous, unmanned, highly efficient, high speed underwater craft. Small, low cost AUVs capable of swarm control are of special interest for military mine applications. No matter the nature of the application or class of craft, a common challenge is the accuracy of maneuvering predic- tions. Maneuvering predictions not only affect design, but also the real time understanding of mission capabilities and endurance. Thus the proliferation of AUVs in recent times for commercial and defense applications have led to the need of higher fidelity of physics based lumped parameter models. The sensor data, along with maneuvering model data can tie into a more accurate trajectory. Multiple such incremental advances in the literature for prediction of maneuvering shall lead to a more accuracy. This work hopes to bridge some important gaps that ensure the creation of such a non-linear LPM to predict the maneuver- ing characteristics of an AUV using non linear hydrodynamic derivatives obtained through static and dynamic CFD. This model shall be implemented for the craft designed for DIVE technologies, our industrial sponsor and an in-house craft, the 690. This model shall also be made generalized for most submerged craft with a torpedo or slender hull form, with cruciform or X configuration of fins. This dissertation looks to provide the framework to identify CFD informed high fidelity dynamic model for AUVs. The model thus created shall be spe- cialized to account for specific important effects such as flow interaction among appendages, effect of using steady and unsteady maneuvers as CFD information and kinematic charac- teristics of captive maneuvers. The specific, innovative contributions in this dissertation are listed below: 1. Definition of a new stability index to incorporate effects of gravity at low-moderate speeds 2. Novel method for identification of hydrodynamic derivatives 3. Systematic and comprehensive study on the parameters affecting VPMM / Doctor of Philosophy / The maneuvering model for an AUV is an indispensable tool that makes the autonomy part of AUVs possible and efficient. The maneuvering model that exists today is mostly linearized and of lower fidelity to increase efficiency. The use of a non linear, higher order hydrodynamic model facilitates better accuracy of maneuvering predictions, essential to mission completion of AUVs applied in research and defense sectors. This higher fidelity can be achieved through informing the model using CFD that is reasonably efficient in computation. This dissertation presents a non-linear, higher order hydrodynamic maneuvering model for the 690 and DIVE crafts, informed with steady and unsteady CFD.