Inositol dehydrogenase (IDH, EC 1.1.1.18) from <i>Bacillus subtilis</i> catalyzes the reversible NAD⁺-dependent oxidation of the axial hydroxyl group of <i>myo</i>-inositol to form 2-keto-<i>myo</i>-inositol, NADH and H⁺. IDH is the first enzyme in catabolism of myo-inositol, and <i>Bacillus subtilis</i> is able to grow on <i>myo</i>-inositol as the sole carbon source. Our laboratory has previously shown that this enzyme has an unusual active site that can accommodate large hydrophobic substituents at 1L-4-position of <i>myo</i>-inositol.<p> In this dissertation, the further characterization of this IDH is described, with focus on the mechanism, inhibition, kinetics, substrate binding, and alteration of substrate specificity. A kinetic isotope effect study revealed that the chemical step of the reaction was not rate-limiting. In order to probe the inositol-binding site, five inositol analogues were synthesized and evaluated as competitive inhibitors. Recently the crystal structures of the <i>apo</i>-IDH, <i>holo</i>-IDH and ternary complex have been solved. Using structural information, as well as modeling and sequence alignment approaches, we predicted the active site structure of the enzyme. On the basis of these predictions, coenzyme specificity was converted from entirely NAD⁺-dependent to 6-fold preference for NADP⁺ over NAD⁺ by site-directed mutagenesis. The critical residues for coenzyme recognition were therefore identified. Besides coenzyme specificity alteration, eleven amino acid residues in and around the proposed <i>myo</i>-inositol active site were also modified to test their roles in order to improve our understanding of substrate binding and activation.

One of the main challenges that investors in the Clean Development Mechanism (CDM) project face is the management of the volatility of the price of Certified Emission Reduction (CERs). Large scale CDM projects require a long-term investment with significant amount of costs, and this type of investment is often irreversible. Project investors should quantitatively assess the CER trigger price that justifies the initiation of a CDM investment. The traditional discounted cash flow valuation is unable to capture the option value associated with uncertain investment, and thus it tends to underestimate the trigger price which initiates the investment. Real options theory explicitly considers the option value of delayed investment and can provide a better measurement of the trigger price. This paper presents a theoretical model of the CDM investment project and derives the CER trigger prices that guide investment decisions by using historical market data. It develops a stochastic dynamic programming model for both the geometric Brownian motion process and the mean-reverting process. An analytical solution for the trigger price is derived for the former process, and the trigger price is numerically estimated for the latter. By considering various parameter values, it analyzes the effects of different market environments on the trigger price.

We consider here a class of mechanisms consisting of one or more compliant members, the manipulation of which relies on the deflection of those members. Compared with traditional rigid-body mechanisms, compliant mechanisms have the advantages of no relative moving parts and thus involve no wear, backlash, noises and lubrication. Motivated by the need in food processing industry, this paper presents the Global Coordinate Model (GCM) and the generalized shooting method (GSM) as a numerical solver for analyzing compliant mechanisms consisting of members that may be initially straight or curved. As the name suggests, the advantage of global coordinate model is that all the members share the same reference frame, and hence, greatly simplifies the formulation for multi-link and multi-axis compliant mechanisms. The GCM presents a systematic procedure with forward/inverse models for analyzing generic compliant mechanisms. Dynamic and static examples will be given and verified experimentally. We also develop the Generalized Shooting Method (GSM) to efficiently solve the equations given by the GCM. Unlike FD or FE methods that rely on fine discretization of beam members to improve its accuracy, the generalized SM that treats the boundary value problem (BVP) as an initial value problem can achieve higher-order accuracy relatively easily. Using the GCM, we also presents a formulation based on the Nonlinear Constrained Optimization (NCO) techniques to analyze contact problems of compliant grippers. For a planar problem it essentially reduces the domain of discretization by one dimension. Hence it requires simpler formulation and is computationally more efficient than other methods such as finite element analysis. An immediate application for this research is the automated live-bird transfer system developed at Georgia Tech. Success to this development is the design of compliant mechanisms that can accommodate different sizes of birds without damage to them. The feature to be monolithic also makes complaint mechanisms attracting in harsh environments such as food processing plants. Compliant mechanisms can also be easily miniaturized and show great promise in microelectromechanical systems (MEMS). It is expected that the model presented here will have a wide spectrum of applications and will effectively facilitate the process of design and optimization of compliant mechanisms.

Following the global warming and climate change in the last twenty years, one of key actions on maintaining biodiversity is to save critical endangered species with aspect of intergrated management. Our study aims to explore integrated mechanism inside the case of Chinese White Dolphin conservation in Taiwan throught a qualitative research approach. The integrated mechanism was also understood under a concept of social-ecological system and analysed with a framework that was modified mitigation-adaptation model used to apply on climate change study. The capacity of management measures including of mitigation and adaptation was explored on three levels, i.e. animals, habitat, and society. Differences of the capacity in these three levels were compared between the cases in Taiwan and Hong Kong. The study also tried to point out possible responders who should conduct these conservation measures from a questionnaire survey. The statistical analysis revealed none of top measures must be under the responsibility of government in these three levels. The analysis showed that there is no correlation between the implementation of measures and the governmental responsibility. In addition, the top-six measures were mainly in the marine environment level and four of the measures had been implemented. In the analysis about governmental responsibility top-seven measures, should be under the responsibility of developers, instead of the government. Some suggestions were given at the end for integrated management of Chinese White Dolphin conservation in Taiwan.

Many researchers in the social science, includes the political science, insist that the main stream of theory of social science depends on structural foundation. But we tried to provided new approach for social science through Elster¡¦s view, on the hand, we clarified what reductionism is, on the other hand, we believed the social science can connect with the natural science by the reductive approach. In order to prove that the natural science¡¦s foundation is the reductive mechanism, we researched the philosophy of natural science and stressed the importance of the ontology and the epistemology. We confirmed the foundation of natural science is micro-mechanism. Elster re-interpret Rational Choice and Marxism through cognition psychology and game theory. We can increase the research range of human behaviors, moral and culture through the intensive explanation.

Underwater operation and sampling has been replaced by ROV (Remotely Operated Vehicle) and underwater manipulator gradually, which can avoid divers to face the dangers due to the environmental pressure and low temperature. When ROV to carry out the mission, the operator sees the undersea environment and the target with the information feedback from the sensors. Recently, we developed a general purpose controller for controlling underwater robotic systems. We plan to install the manipulator on the ROV with the same general purpose controller. One of the concerns in desgining is: the ROV generally mantains neutral buoyant in seawater. When adding or removing any components, the arrangement of balast weight needs to done again to keep the balance of the system. Moreover, the center of gravity will be changed such that dynamics of the ROV will be different when collaborating with the underwater manipulator. To resolve these problems, we review the design and hope to reduce the size and weight of each component.The new design also introduces the use of a junction box. The junction box keeps all the circuits, power converters and motor control card. It allows the reconfiguration of power and commands pathway much easier. To reduces of the size of the housings, the gear transmission set is moved out of the housing. According to the positioning accuray requirement of each axis, a DC servomotor or a DC motor is installed. Underwater manipulators do not require agile motion. Therefore we use a gear-worm set as the transmission between links to increase torque. The motion control is implemented with a Jacobian to calculate the increment joint angles for joint coordinate control. Human-interface was developed with Borland C++ Builder and OpenGL to let the operator to simulate and control of the manipulator with an input of a 3D joystick.

Tandem structure for OLED application with HAT-CN:Alq3 interlayer is studied. It has been found that tandem cell with such interlayer structure has a low turn-on voltage as comparing to other types of interlayer structure. Three research topics are included in this research: (1) Study of carrier generation , carrier transport , and other optoelectronic properties for tandem cells with HAT-CN:Alq3 interlayer. (2) Study of white OLED device with single emitting layer and HAT-CN:Alq3 interlayer. (3) Study of electroluminescence property of top and bottom device of a tandem cell with HAT-CN:Alq3 interlayer. Experimental results show that electron transport is slowing down with increasing Alq3 concentration in the HAT-CN:Alq3 interlayer. However concentration of Alq3 in the interlayer does not affect transport property of hole. A white OLED with HAT-CN:Alq3 interlayer can reach 40,500 cd/m2 at 2180 mA/cm2 with a power efficiency of 1.96 lm/W and CIE coordicate of (0.34,0.32).

Cumene hydroperoxide (CHP), a type of organic peroxide, is widely used in the chemical industry for diverse applications. However, it decomposes and undergoes highly exothermic runaway reactions under high temperature because of its unstable peroxide functional group. The risk of runaway reaction is intensified by the fact that operation temperature of CHP is close to its onset temperature in many cases. To ensure safe handling of CHP in the chemical industry, a lot of research has been done on it including theoretical research at the microscopic level and experimental research at the macroscopic level. However, the unstable radicals in the CHP decomposition reactions make it difficult to study its reaction pathway, and therefore lead to incomplete understanding of the reaction mechanism. The slow progress in theoretical research hinders the application of the theoretical prediction in experimental research. For experimental research, the lack of integration of operational parameters into the reactivity evaluation limits its application in industrial process. In this thesis, a systematic methodology is proposed to evaluate the reactivity hazards of CHP. This methodology is a combination of theoretical research using computational quantum chemistry method and experimental research using RSSTTM. The theoretical research determined the dominant reaction pathway of CHP decomposition reaction through the study of thermodynamic and kinetic stability, which was applied to the analysis of experimental results. The experimental research investigated the effect of CHP concentration on runaway reactions by analyzing the important parameters including temperature, pressure, self-heat rate and pressure rate. This methodology could also be applied to other organic peroxides or other reactive chemicals. The results of theoretical research on reaction mechanism show that there is a dominant reaction pathway, which consumes most of the CHP in decomposition reaction. This conclusion agrees with the experimental results that 40 wt% is a critical point for almost all important parameters of runaway reactions. In the high concentration range above 40 wt%, some unknown reaction pathways are involved in decomposition of CHP because of lack of cumene. The shift of reaction mechanism causes the change of the effect of concentration on runaway reactions.

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In ad hoc network, one needs other nodes to relay data packets. But resources in each node are limited. Therefore, these nodes may not relay other¡¦s data packet without getting any benefit. In this paper, a routing path selecting algorithm based on price mechanism is proposed. It helps nodes to get some benefits by relaying others¡¦ data packets. Moreover, the algorithm we proposed selects a routing path with less payment and more resources. Simulation results show that the drop rate, block rate and the cost of routing paths are reduced compared to the competing algorithms.