Stability is a critical issue in gain-scheduled control problems in that the closed loop system may not be stable during the transitions between operating conditions despite guarantees that the gain-scheduled controller stabilizes the plant model at fixed values of the scheduling variable. For Linear Parameter Varying (LPV) model representations, a controller interpolation method using Youla parameterization that guarantees stability despite fast transitions in scheduling variables is proposed. By interconnecting an LPV plant model with a Local Controller Network (LCN), the proposed Youla parameterization based controller interpolation method allows the interpolation of controllers of different size and structure, and guarantees stability at fixed points over the entire operating region. Moreover, quadratic stability despite fast scheduling is also guaranteed by construction of a common Lyapunov function, while the characteristics of individual controllers designed a priori at fixed operating condition are recovered at the design points. The efficacy of the proposed approach is verified with both an illustrative simulation case study on variation of a classical MIMO control problem and an experimental implementation on a multi-evaporator vapor compression cycle system. The dynamics of vapor compression systems are highly nonlinear, thus the gain-scheduled control is the potential to achieve the desired stability and performance of the system. The proposed controller interpolation/switching method guarantees the nonlinear stability of the closed loop system during the arbitrarily fast transition and achieves the desired performance to subsequently improve thermal efficiency of the vapor compression system.

Metal diketonato complexes are populate in recent ten years, because of diketone compound is easy to get and cheap and also have good volatility to be the precursor of MOCVD, they usually can be the materials of wafer processing by high technology electronics industries. Many scientists are trying to synthesis these diketonato complexes, and find out the better reactivity compounds to be the precursor of MOCVD. In order to knowing the decompose activities of these complexes, we are trying to compare the metal-oxygen bonds of these diketonato complexes in this paper. By the way, these diketonato complexes have difference geometry in cis and trans form, and also have conformation isomers between syn and anti form. We will compare and discuss the structures and controlling factors in these kinds of diketonato complexes in this paper.

In today&amp / #8217 / s market conditions, higher tool life and durable cutting tools which can stand high cutting speeds are required in chip removal process. In order to improve the performance of cutting tools, coatings are employed extensively. Cubic boron nitride (cBN) is a new kind of coating material for cutting tools due to its outstanding properties and testing of cBN as a hard coating for machining have been increasing in recent years. However, there are some challenges such as compressive residual stress, poor adhesion and limiting coating thickness during the deposition of cBN on substrates. In this study, cubic boron nitride (cBN) coatings are formed on cutting tools from hexagonal boron nitride (hBN) target plates. For this purpose, a physical vapor deposition (PVD) system is utilized. PVD system works on magnetron sputtering technique in which material transfer takes place from target plate to substrate surface. Firstly, cBN coatings are deposited on steel and silicon wafer substrates for measurements and analyses. Compositional, structural and mechanical measurements and analysis are performed for the characterization of coatings. Next, several types of cutting tools are coated by cBN and the effects of cBN coatings on cutting performance are investigated. Finally, it can be said that cubic boron nitride coatings are successfully formed on substrates and the improvement of wear resistance and machining performance of cBN coated cutting tools are observed.

Carbon nanotubes have received considerable attention since their discovery due to their novel properties. They have potential application areas in physics, chemistry and biology. Arc discharge, laser furnace, chemical vapor deposition and floating catalyst methods are the most commonly used methods to produce carbon nanotubes. Although carbon nanotubes have superior properties compared to other materials, they could not be used widely. The main reasons of this are that continuous and large scale production of carbon nanotubes could not be achieved and impurities have to be removed. To solve these problems more information about formation of carbon nanotubes has to be known. In this study concentration profiles of reactant and byproducts in a cylindrical reactor are investigated during carbon nanotube production. A special probe to collect gas samples along the reactor and samples loops to store the gas samples were designed and constructed. Gas samples were analyzed one by one in GC/MS. Experiments were done with and without catalyst at same experimental conditions. Thus, effects of catalyst on concentration profiles of chemicals were analyzed. To produce carbon nanotubes more acetylene was used compared to amount of acetylene used in pyrolysis. Increasing reaction temperature from 800&deg / C to 875&deg / C caused decomposing more acetylene and producing more carbon nanotubes. It is believed that data accumulation on the reactions involved in the gas phase will lead to large scale production and lower product costs with a large catalyst surface to be produced in the reactor.

Carbon nanotubes (CNTs), allotropes of carbon with a cylindrical nanostructure, are one of the most attractive research subjects for scientists and industry because of their extraordinary chemical, electrical, optical, mechanical and thermal properties, and their wide range of potential application areas. Mainly, there are two types of carbon nanotubes: single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). The most commonly used methods for carbon nanotube production are arc discharge, laser ablation, and chemical vapor deposition (CVD). In the CVD method, CNTs are produced from thermal decomposition of the carbon-containing molecules on a suitable transition metal catalyst. CVD method enables large scale production of high-quality CNTs with low cost compared to other methods. The growth and morphology of CNTs can be controlled by adjusting the reaction parameters. In this study, Co and Mo impregnated CaCO3 catalysts were synthesized at different Co:Mo weight ratios and calcined at different temperatures. XRD results showed that there was mainly CaCO3 compound in the catalysts calcined at 500&ordm / C whereas the catalysts calcined at 700 and 750 &ordm / C were mainly composed of CaO and Ca(OH)2 compounds. In addition to these, CaMoO4, CoO, CoMoO4 and Mo2C were the other solid phases mainly observed in all catalysts. The production of CNTs was performed by chemical vapor deposition of acetylene at a temperature range of 500-700

Nanomaterials are widely investigated by researches and because of their unique properties they have been utilized in many different devices. Nanowires are one of these materials which show deviated mechanical, chemical, physical and optical, properties from their bulk counterparts. These deviations in properties of the nanowires are based on both their high surface to volume ratio and quantum confinement effect. Lately optical properties of nanowires have received great attention as they also exhibit good light sensitivity. Germanium is a semiconductor, which has been used widely as an active material in infrared light detectors. Due to excellent light detection of germanium its nanostructures have also been widely studied in optoelectronic devices. Germanium nanowires have been used in many devices such as field effect transistors, diodes, field emitters and photodetectors. Synthesis of high quality and high aspect ratio germanium nanowires could make important contributions to these devices. There are several synthesis methods for germanium nanowires. These are electrochemical etching, solvothermal, supercritical v fluidic, laser ablation, chemical vapor deposition and vapor transport methods. Among these methods, high quality, single crystalline, defect free germanium nanowires using accessible solid powder precursors could be synthesized with vapor transport method. In the first part of this thesis, germanium nanowire growth with vapor transport method is investigated. One of the most advantageous features of this method is using solid powder precursors instead of toxic gases. Until now, three different kinds of solid germanium precursors have been reported in vapor transport method, all of them are investigated and the resulting nanowires are compared in this thesis. Vapor transport method enables high control over the morphology of the nanowires. The most important parameters which affect the morphology of the nanowires are temperature, pressure and precursor type. Therefore, a detailed parametric study is provided based on these parameters and their effect on the final diameter of the nanowires is determined. The as &ndash / synthesized nanowires contain a very thick oxide layer on their surface. Therefore, oxide removal with acid etching is also investigated in this thesis. In the second part of this thesis, utilization of the germanium nanowire networks in fully transparent, flexible and network enhanced photodetectors is investigated. In order to obtain a germanium nanowire network, the as-synthesized nanowires are transferred from growth substrate to the device substrate by sonication and vacuum filtration. Silver nanowires and single walled carbon nanotubes are used as fully transparent electrodes. Both rigid and flexible photodetectors are fabricated and their current-voltage characteristics and photoresponse behaviors with different germanium nanowire densities are determined.

The development and advancement of microelectronics technology have been dramatically. The time and cost, for research and optimization of process and equipment, can be saved by using flow simulation. The governing equations of flow field, inside chemical vapor deposition (CVD) reactor, are constructed, dispersed, and solved by grid mesh and numerical method. At present, rapid thermal process (RTP) is becoming more important and popular for thin-film depositing technology. In this thesis, vertical type single wafer RTCVD reactor in poly-silicon thin-film depositing process is analyzed by numerical method. Several operating process parameters, such as: (a) the gap between shower head and wafer surface, (b) gas inlet velocity in shower head, and (c) operating pressure inside chamber of reactor, are considered for discussion and analysis of steady or unsteady phenomenon in three steps of thin-film depositing process, including (¢¹) heating for wafer, (¢º) deposition in steady state, (¢») cooling after deposition etc.. As shown in the results, each operating parameters performs different relations and phenomenon in these steady and unsteady steps: Operating pressure can affect the activity of chemical reaction strongly in unsteady or steady region. Larger gap between wafer and shower head causes less influence by flow effects or buoyancy. And also, radiation heat transfer, which is adopted by RTCVD process, can decrease the influence of some parameters on flow field.

This study investigated the feasibility of glassfiber filter coated with titanium dioxide (TiO2) on removing indoor VOCs using photocatalytic technology, which could further expand the electronic filter¡¦s function . First of all, we coated the titanium dioxide (TiO2) photocatalysts on the glassfiber filter with chemical vapor desposition (CVD) method, then dried it at 120¢J, and calcined it to prepare a nano-sized TiO2 coated filter . Secondly, we collected VOC samples in a printery and analyzed their chemical components. The main components of VOCs (benzene¡Btoluene and acetone) were then conducted in a self-designed laboratory-scaled batch photocatalytic reactor. The decomposition of acetone for different operating parameters, including initial VOC concentration, CVD coating time, and calcination temperature, was further conducted. Besides, a nano-sized photocatalyst indoor air purifier was self-designed for this particular study. The air purifier consists of a set of near-UV light source, a nano-sized photocatalyst glassfiber filter, a stainless shelter, and a circulating fan. The air purifier was tested to ascertain its capability on the removal of indoor VOCs in a well-tight environmental chamber. The testing results indicated the nano-sized photocatalyst glassfiber filter can be used to remove indoor VOCs . In the final stage, a nano-sized TiO2 photocatalyst electronic air cleaner was self-designed for this particular further study in a printery. The air cleaner consists of a set of UV light source, a nano-sized photocatalyst glassfiber filter, a set of electronic filter, carborn filter and a pain coated steel plate shelter. The air cleaner was tested to ascertain its capability on the removal of indoor VOCs in a return air channel of air condition system. The testing results indicated that the nano-sized photocatalyst glassfiber filter can be used to remove indoor VOCs

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Chemical vapor deposition technology is often by using in the one of Wafer panel Foundry process, the heat transfer coefficient on the top substrate surface is the very important influence parameter in the manufacturing process. For this reason, the main object of this thesis is apply liquid crystals heat transfer measurement technique to set up a temperature measurement experiment system of transient thermochromatic liquid crystals and application simulating CVD process technique. Furthermore, an experimental is carried out in the present study to investigate the characteristics of heat transfer experiment study analysis resulting from a low speed air jet through the nozzle eccentric disc outlet impinging onto a rectangular acclivitous angles substrate confined in a vertical rectangular chamber. Finally, heat transfer coefficient empirical equations of the three relationship are proposed to Nusselt number correlate the effect of Reynolds number¡BSeparation distances are Ratio of outlet and acclivitous substrate surface¡BAngles of rectangular acclivitous substrate.