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The use of renewable energy as part of the solution for stabilising global warming has been promoted in industrialised countries for the past three decades. In the last ten years, China, a non-democratic and less-developed state, has implemented non-hydro alternative energy sources through top-down, technology-oriented measures and expanded its renewable energy capacity with unprecedented speed and breadth. This phenomenon seems to contradict to the principle of orthodox environmental governance, in which stakeholder participation is deemed as necessary condition for effective policy outcomes. Given that little research has been conducted on environmental politics in an authoritarian context, I first set out to explore the role of the Chinese state in enabling transformation of the renewable energy sector and to understand the ways in which policy elites seek to introduce developmental state and ecological modernisation strategy in the policy area. Second, by adopting principal-agent theory, I explicate how the governance mechanisms have been deployed and how challenges of the expansion of the sector in the governance system with a large territory have being mitigated. Based upon news reports, policy documents, and interviews with 32 provincial officials, business leaders, academic researchers, and NGO practitioners in two subnational governments, I argue that the renewable energy development in China is governed through a hybrid mode of environmental policy model that uses, upon the existing developmental state regime, ecological modernisation as a policy paradigm, which is partially incorporated in the process. Ultimately, I examine in this thesis the possibility of an alternative form of environmental governance in which renewable energy can be diffused in a less-participatory manner, with more direct controls and target-oriented state intervention measures. This thesis challenges the orthodox assumption that the inclusive mode of governance are the only capable form of environmental governance that reaches desired policy outcomes of renewable energy deployment.

Niemann-Pick type Cl (NPC1) disease is a neurodegenerative lysosomal storage disorder characterized by the accumulation of multiple lipids in the late endosome/lysosomal system and reduced acidic store calcium levels. Since the lysosomal system is involved in regulating aspects of transition metal ion homeostasis and its intracellular compartmentalization, we have investigated whether there are metal ion metabolism defects and haematological abnormalities in NPC1 disease. We have identified multiple haematological changes, including decreased haematocrit, haemoglobin and mean corpuscular haemoglobin volume in mice.

This thesis presents an evaluative case study of the 20 English training courses offered in the Applied English Department (AED) of an Institute, given the pseudonym W.G, in southern Taiwan. No evaluation had been done since the AED had been set up and using Stufflebeam’s CIPP (Context, Input, Process and Product) evaluation model this research was carried out. The purpose of the research was to attempt, through the gathering of qualitative data from a variety of sources and using a variety of research instruments, an evaluation of the 20 English training courses which were designed for and taken by students who hoped, mainly, to become children's English language teachers. The courses were examined through four key components, namely, "course aims and objectives", "course contents and materials", "course conduct and teaching-learning process" and "assessment and student performance". Data were gathered through questionnaires, interviews and the review of existing documents and was obtained from current students, directors of the AED, instructors, alumni and employers of alumni. The resultant data served to present a comprehensive overview of the AED and the 20 English training courses and furnished evidence sufficient to allow for a number of recommendations for improvement and change to emerge. Fundamentally it is not clear that there is sufficient congruence of students needs and the courses offered. It emerged that the AED would probably benefit from a refocusing of student needs, a review of AED structures and governance, uniform syllabus design and presentation, a review of student feedback on instructor performance and a number of fundamental adjustments to the courses, in particular, their content, teaching methodology and assessment. Overall the AED had many positive aspects all of which could be built on and added to as the results of the data suggested. It emerged that the CIPP evaluation model has, in the educational context, a lot to commend it and this has been illustrated in this research. If followed carefully it covers all aspects and features of a program and provides a methodical, all-embracing design which can produce useful material for exploration and adoption if appropriate. It is in most cases a positive program enhancing exercise designed to develop rather than close existing programs.

Studies have highlighted the prevalence of sedentary behaviours in the university student population and have noted the significant potential for the promotion of physical activity in educational settings for young adults. Following the epidemiological procedure and ecological approach, the main purpose of this thesis focused on the university student population to review the previous research results by a systematic review method (first study), to compare the differences between UK and Taiwanese participants' and relevant effective variables by using a quantitative study method (second study), to have a deeper understanding of the Taiwanese university students' physical activity behaviours by using a qualitative study method (third study), then to evaluate the efficiency of designed interventions in university settings (fourth study). The whole thesis applied the ecological approach to classify the survey variables' effect to university students' physical activity behaviours. A total of 55 published papers were reviewed and majority of studies were conducted in the US using a cross-sectional design. Finding variables consistently related to university students physical activity level were female gender(-), attitude self-efficacy perceived barrier (-), family support (+), physical activity and sport history (+). These survey variables were more consistent in the literature and corresponded to previous adults' study. Some survey variables linked to university student were also found in the literature but still need more studies for this target population to come to a robust conclusion. Seven days recall design measurement and stage of changes survey for physical activity levels were more identified and have been more frequent using in the reviewed papers. Also, more studies on different ethnicity, environmental variables and intervention with different methodology such as qualitative study method are needed to enrich the knowledge of university's students' physical activity behaviours.

This is a study of how one can successfully justify the universality of human rights to people with a diversity of beliefs and values. I argue that intercultural dialogue is an essential part of working out an interpretation of human rights that is acceptable to a broad range of cultures. I develop this position through critical engagement with three recent philosophical approaches to the intercultural validity of human rights: John Rawls's Law of Peoples, Martha Nussbaum's Human Capabilities approach, and Abdullahi An-Na'im's cross-cultural dialogue approach. Inspired by Judith Shklar's political liberalism of fear and Ins Young's critical theory, I seek an account of human rights that has normative legitimacy from the perspectives of marginalized and victimized people. Cross-cultural dialogue in my scheme is a bottom-up approach from the victimized and powerless people that can avoid the problem of generality and provide multiple routes to reach agreement regarding universal human rights. In the end, I believe my approach will be descriptively more suitable to the moral reality of universal human rights, and provide a normative grounding of human rights in a way that is more compelling than other approaches.

Al-Si based casting alloys are widely used for piston applications. This is due to their combination of properties, which include good castability, high strength, light weight, good wear resistance and low thermal expansion. In order for such alloys to meet increasingly demanding operational requirements, such as higher service temperatures and pressures, multicomponent Al-Si alloys, which contain several other alloying additions (Cu, Ni, Mg, Mn and Fe), have been used to further enhance the high temperature strength and fatigue resistance. Improved material properties are strongly dependent upon the morphologies, the thermal and mechanical properties, and the distribution of the intermetallic phases present in these alloys, which are in turn a function of alloy composition and cooling rate. Therefore, the main aim of this work was to characterise the many complex intermetallic phases in multicomponent Al-Si alloys. Five main areas of interest were investigated in this research. Firstly, thermodynamic modelling has been used to predict phase formation in complex alloys, which has been compared with measurements from differential scanning calorimetry (DSC). Secondly, the presence of additional elements in multicomponent Al-Si alloy systems allow many complex intermetallic phases to form, which make microstructural characterisationn on-trivial, as some of the phases have either similar crystal structures or exhibit subtle changes in their chemistries. A combination of electron backscatter diffraction (EBSD) and energy dispersive X-ray analysis (EDX) have therefore been used for discrimination between the various phases. It is shown that this is a powerful technique for microstructure characterisation and provides detailed information which can be related to the microstructuree volution during initial casting and subsequent heat treatment. Additionally, the complex morphologies of intermetallics have also been observed using 3D X-ray tomography. In this present work, a number of different experimental techniques were used to provide a rapid means of phase discrimination in order to validate microstructural evolution models. Thirdly, the mechanical properties of individual intermetallics have been investigated as a function of temperature using high -temperature nanoindentation. In particular, the hardness and modulus of a number of phases have been measured for a range of alloy compositions. The creep behaviour of intermetallic phases was also investigated, since this is important in the determination of the high temperature mechanical properties of alloys. Fourthly, the coefficients of thermal expansion of intermetallic phases were measured by high temperature X-ray diffraction, and thermal expansion anisotropy was also explored to investigate the formation of microcracking. Finally, in order to investigate the effect of both applied mechanical and thermal loads on the formation of cracks, Eshelby modelling has been used to predict the internal stresses of the different intermetallic phases and alloys, with the aid of the experimental data obtained in this work. The phase identity, composition, and the corresponding physical and mechanical properties can be used to inform alloy design strategies which, may facilitate the development of new alloys with improved properties.

A large range of products are now designed based on the implementation of microcontrollers, as they lead to an overall system enhancement, such as a more compact system design and reduced costs. This can be credited to the peripheral functions embodied in the microcontroller and the flexibility offered by its software. Since the applications of microcontrollers are achieved through software, the implementation of the target controller is considered as an interdisciplinary process. Due to the capability of the current development tool, designers are required to input significant effort such that the development with the process is taking a long time to complete. The purpose of this research is aimed at improving the current microcontroller software development process.

This thesis describes work done in investigating Er3+-doped fibre amplifiers and lasers, with emphasis on the spectral properties and diagnosis of ion-ion interaction processes in the glasses and fibres. Ion-pair upconversion and uniform upconversion in Er3+-doped silicate fibres have been directly and separately observed for the first time, by examining upconversion fluorescence. An upper limit to the Er3+ ion-pair lifetime of a few microseconds has been determined. Different effects of the two upconversion mechanisms on the 1.54µm fluorescence have been examined. Ion-pair upconversion in an Al/Ge/Si or an Al/Si host increases far less with increasing Er3+ concentration than in a Ge/Si host, while there is no significant difference in uniform upconversion between them for a given Er3+ concentration. Uniform upconversion constants for various fibres are determined through measuring the maximum decay rate of the 1.54µm fluorescence. The 1.7µm ESA spectrum from the 4H13/2 level has been measured for Er3+-doped silicate fibre and ion-exchanged silicate planar waveguides, and the uniform upconversion constants are estimated. The existence of dual excited-state energy transfer (DESET) in Er3+/Yb3+- doped phospho-silicate fibres has been inferred from measurement of the ESA spectrum around 1.1µm. The absence of ESA at pump wavelength 1.064µm has also been confirmed. The DESET process has been examined for the first time by measurements of 1.064µm pump throughput characteristics of the fibre. Short Er3+/Yb3+ amplifiers pumped at around 970nm have been numerically characterized. The advantage of codoping of Yb3+ is shown to be the potential for higher gain at shorter amplifier length. By examining Er3+-doped fibre preforms with differing co-dopant ions, Ta5+- codoped fibre is shown to be competitive with Al3+-codoped fibre for Er3+-doped fibre devices. A SiGeTaEr fibre laser has been demonstrated for the first time. Spectral properties of Er3+-doped Ga2S3:La2S3 have been studied. Emission and absorption spectra, including for the first time the 2.7µm emission, are measured. Radiative and non-radiative transition rates are calculated and compared with the measured lifetimes. Characteristics of ion-ion energy transfer processes in the glass are discussed. A numerical model has been developed to predict the Performance of Er3+:Ga:La:S fibre devices, including short amplifiers operating at 1.54µm, 980nm upconversion lasers.

It is generally believed that Business to Business (B2B) e-commerce has a great impact on business performance improvement. Considerable research also shows that another dependent variable, B2B e-commerce success, can be a good overall measure of B2B systems. This paper investigated and examined the impact of several factors, which are either internal or external to the firm on B2B performance improvement and B2B e-commerce success. It is suggested that the various factors affect B2B success through business performance improvement. A research model was developed to test and evaluate these factors. A survey instrument was developed to examine the relationships between these factors and business performance. Survey data was collected online from 143 companies in the U.S.A. and Taiwan where their B2B e-commerce systems were operational for more than 1 year. Structural Equation Modeling (SEM) technique was used to assess the measurement and the structural model. Analyses and results of the pooled survey data suggest that the following factors are significant in the B2B e-commerce environments: (a) alignment of business and e-commerce strategy has a positive impact on business performance, (b) strong relationships between the trading partners have a positive influence on business performance, and (c) B2B e-commerce success is significantly influenced by business performance improvements. Thus, firms that seek to implement successful B2B systems should focus on business performance improvements. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

An extensive survey made of published survival data of damage by ionizing radiation to mammalian cells in vitro has led to the new conclusion that the damage is determined by the specific ionization or the mean free path between ionizing events along the charged particle tracks. The optimum damage is observed when the mean free path is equivalent to the DNA double strand spacing of 1.8 nm. Therefore, the biological mechanism of ionizing radiation to mammalian cells in vitro is intra track dominant. A 100 keV electron accelerator has been constructed and commissioned to produce a broad beam irradiation field of greater than 1 cm diameter. The fluence rate may be adjusted from 10 8 cm-2-sec-1 downwards to enable further development as a chronic irradiation facility. Another new feature of the accelerator is that it incorporates a differential vacuum system which permits irradiation of the monolayer cell cultures to be carried out in normal pressure. Experiments of irradiation to Chinese hamster cells, by 241Am alpha particles at low fluence rate, have supplied satisfactory data for testing a new DNA-rupture model which is under development. For V79 cells irradiated at a low fluence rate of 105 cm-2-min-1, when survival data were fitted into the model, new biophysical parameters were extracted and a proposal was made that the repair phenomenon of cellular survival at very low doses is determined by three time factors; the irradiation time, the damage fixation time and the repair time. The values obtained were 3-4 hours for the mean repair time, and more than 10 hours for the damage to be considered permanent. Details of the monolayer cell culture technique developed and used in the present experiments are described. Consideration has been given to the significance of the results obtained from the study in radiation protection and in radiotherapy. In future studies it is recommended that more attention should be paid to measure the ionization events of the radiation studied. Towards the objective of producing a unified dosimeter, more studies are needed to correlate the results for electrons and neutrons for which less data are available. In this thesis the background and the basic theories are introduced in Chapters I and II. Experimental details are described in Chapter III on physical aspects and Chapter IV on biological aspects. Finally the results and discussion are presented in Chapter V.

A cyber-physical system (CPS) with both autonomous and manual control capabilities, or a semi-autonomous (SA) system, is one of the most commonly seen types of system in our daily lives, such as cars, airplanes and ships. While having the benefits of autonomous control to enhance safety/comfort of transportation and the flexibility of manual control to handle safety-critical situations, SA systems inevitably inherit the vulnerabilities embedded in both control types. That is, an SA system will also suffer from component failures or design/software bugs (e.g., crashes of Boeing 737 MAX) and potential attacks (e.g., sensor spoofing) as a general CPS does. Moreover, since mechanical components are gradually being replaced by their electronic counterparts in SA systems, this trend also introduces new reliability and security risks — increasing adoption of multiple heterogeneous communication interfaces widens attack surfaces that an adversary can exploit. Considering the potential security and safety concerns caused by system faults/flaws, human error, and malicious attacks, we develop a suite of mechanisms/systems for detection and resolution of system anomalies by cross-validating the sensor data and the context information to enhance the security and safety of SA systems from three key perspectives that can directly influence the operation of SA systems — system operation, received information, and control decisions. In this thesis, we propose both domain-general design for SA systems and its domain-specific realization using SA vehicles as a concrete case study. From the system operation perspective, we propose CADD, a context-aware anomaly detection system, to capture abnormal system behavior under various operation contexts while considering practical scenarios where some (context) information cannot be observed by the SA system. We then present DiVa, a diagnostic system that pinpoints/identifies the anomalous source(s) after an anomaly is detected. It exploits the cyber-physical correlation or causality between the internal data of the SA system to narrow down the origin of anomaly while assuming no data can be entirely trusted. From the received information perspective, we propose EDRoad, an easy-to-use system for verification of the data received from external sources to ensure no compromised data will be used to provide services to the SA systems. Finally, from the control decision perspective, we introduce CADCA, a system for detecting and resolving control actions that may potentially lead to unstable system states or safety-critical situations.

Polycyclic xanthone natural products (PXNPs) are a family of polyketides which are characterized by their highly oxygenated, angular hexacyclic frameworks and a diverse range of biological activities. The dissertation research described herein has been focused on the syntheses of the citreamicins, a subset of polycyclic xanthone natural products with a unique five-membered hemiaminal moiety. To the best of our knowledge, there have been no published reports on the total synthesis of any member of the citreamicins subclass. We have targeted the citreamicins in hopes of developing a concise method to easily access the citreamicin family and other related PXNPs. In the effort to synthesize the congener citreamicin η, two different synthetic routes that we simultaneously pursued will be presented. In the first route, a convergent regioselective arylation of xanthone quinone monoketals was developed. In the second route, a one-pot, regioselective Diels-Alder/oxidation reaction was accomplished. Finally, a novel acyl radical cyclization was employed to construct the pentacyclic core of citreamicin η under mild reaction conditions.

Internet use has become an integral part of youth’s everyday life. While the Internet brings convenience for information access, communication, and entertainment (e.g., Thorsteinsson & Davey, 2014; Wallace, 2014), when the mechanism of Internet use becomes maladaptive, a phenomenon called problematic Internet use (PIU) arises. PIU among youth has been defined as excessive or maladaptive use of online activities, which interferes with youth’s development, academic performance, and social life in negative ways (Beard & Wolf, 2001; Ceyhan, 2008; Ioannidis et al., 2019). Across the world, China was the first country that recognized PIU as an official mental health concern, given the significantly high and increasing trend of PIU prevalence rates among Chinese youth (Jiang & Leung, 2011). Previous research has well-documented the detrimental outcomes of PIU among Chinese adolescents. However, there has been a lack of investigation on the etiology of PIU from a social and cognitive perspective. In Study 1, structural equation modeling (SEM) was used to empirically identify how PIU differed between students’ sex, family income level, and left-behind status as well as to examine the relations between SEL competencies and PIU. Results yielded that male students endorsed higher levels of PIU and time management on the Internet than female students, whereas no differences were observed across family income levels and left-behind status. In addition, students with higher levels of SEL competency and all five core domains of SEL competencies (i.e., responsible decision-making, social awareness, self-management, self-awareness, and social relationship) reported less frequent PIU, illustrating the preventative roles of SEL competencies on PIU. Based upon Study 1, Study 2 considered social factors additional to the cognitive factors when studying the etiology of PIU. Similar to Study 1, SEM was used to examine the associations between traditional bullying and cyberbullying victimization and PIU, and the moderating effects of SEL competency and five core SEL domains on the associations between traditional bullying and cyberbullying victimization and PIU. Upon controlling for students’ demographic variables, the study found that students who experienced more frequent traditional bullying and cyberbullying victimization reported a higher level of PIU. SEL competency, social-awareness, relationship skills, and self-awareness exacerbated the positive relationships between traditional bullying victimization and PIU. Taken together, the findings from both studies supported the preventive roles of SEL competencies and detrimental roles of bullying victimization on PIU and revealed the promoting effects of both overall and domain-specific social-emotional attributes in PIU development when youth faced bullying, which intended to inform and facilitate the preventative and interventive efforts on Chinese adolescents’ bullying victimization and PIU.

In the multiple and huge costume field, any idea will be possible. Costume technicians operate multiple skills to represent the design from the costume designer. This project is using the Nitinol Alloy, the Shape Memory Wire, which changes shape by temperature, in combination with fabrics to represent the blossoming of flowers. The main idea is trying to use the different materials which I never used or which never been used with (theatre) costumes and developing the material to another possibility. The result of this thesis could provide a possibility to the costume designer

Topological superconductors and superfluids are an exciting class of recently discovered materials. In one dimension, topological superconductors accommodate a novel kind of bound state, known as a Majorana zero mode, at their endpoints, and introducing strong correlations can lead to systems with related types of bound states known as parafermions. In this thesis, we systematically studied three correlated aspects of topological superconductivity and superfluidity in low-dimensional quantum systems. By using Bogoliubov--de Gennes (BdG) theory combined with proper topological-invariant calculation, we first predicted a new topological Fulde--Ferrell--Larkin--Ovchinnikov (\emph{topo}-FFLO) superfluid state in one-dimensional ($1$D) spin-orbit-coupled Fermi gases (with superfluid order stabilized by $3$D interactions). Specifically we demonstrate that Majorana zero modes can exist even if the superconducting/superfluid pairing is at nonzero momentum (i.e. of FFLO type), provided that the magnitude of the superconducting/superfluid gap is finite. $1$D topological superfluids are typically classified and understood through BdG mean-field Hamiltonians. This raises the question of whether they can exist in truly $1$D systems where particle number is conserved. We discuss a new mechanism by which Majorana zero modes can arise in a number-conserving Fermi ladder. This interaction-enabled topological phase is protected by a unitary $\mathbb{Z}_2$ symmetry that is not related to any microscopic fermion-parity symmetry. Generalizations of Majorana bound states can also occur by inducing superconductivity at the boundary states of certain types of fractional quantum Hall bilayers. Then how could we detect them experimentally? In this thesis, we discuss two answers---dynamical signatures and characterizing the finite-sized splitting of the otherwise degenerate ground-state Hilbert space associated with these bound states. Particularly, in the process we demonstrate how instanton methods can be applied to the general problem of ground-state energy splittings in these systems.

The rapid growth of computing power has expedited scientific simulations which can now generate data in unprecedentedly high quality and quantity. However, this advancement has not been mirrored in I/O performance, and hence scientific research is facing great challenges in visualizing and analyzing large-scale simulation results. Among areas of scientific research, fluid flow analysis plays an important role in many disciplines such as aerospace, climate modeling and medicine applications. The data-intensive computation required for fluid flow visualization makes it difficult to devise efficient algorithms and frameworks for flow analysis. First, to analyze a time-varying flow field, pathline visualization is typically used to reveal particle trajectories in the flow. Pathline computation, however, has irregular data access pattern that complicates out-of-core computation when the flow data are too large to fit in the main memory. Strategies on modeling the access pattern and improving spatial and temporal data locality are needed. Second, to avoid tremendous I/O latency, the simulated flow field results are typically down-sampled when they are stored, which inevitably affects the accuracy of the derived pathlines. Error reduction and modeling becomes important to enable uncertainty visualization in order for better decision making. This dissertation addresses the above challenges by data summarization approaches that efficiently process large data into succinct representations to facilitate flow analysis and visualization. First, a graph modeling approach is employed to encode the data access pattern of pathline computation, with which a cache-oblivious file layout algorithm and a work scheduling algorithm are proposed to optimize disk caching during out-of-core pathline visualization. Second, an incremental algorithm is devised that fits streaming time series of flow fields into higher-order polynomials and estimates errors in a compact distribution model. The benefit of this distribution-based error modeling is demonstrated to enable probabilistic uncertain pathline computation. Finally, a case study of jet engine stall is conducted for large flow simulations. Vortex analysis and various anomaly detection methods are proposed to capture flow instability that may lead to stall. Comparative visualization techniques are then employed to reveal and contrast temporal patterns from the detection results. Positive expert feedback shows the effectiveness and potential of the proposed methods for stall analysis in large-scale flow simulations.

In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ~ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated polyelectrolyte layer functioning as the surface dipole formation layer to provide better electrical contact with the photoactive layer. Due to the effectiveness of the conjugated polyelectrolyte layer, performance improvement was also observed. Furthermore, other issues regarding the semi-transparent tandem solar cells (e.g., photocurrent matching, exterior color tuning, and transparency tuning) are all explored to optimize best performance. In Chapter 5 and 6, the architectures of double- and triple-junction tandem solar cells are explored. Theoretically, triple-junction tandem solar cells with three photoactive absorbers with cascaded energy bandgaps have the potential to achieve higher performance, in comparison with double-junction tandem solar cells. Such expectations can be ascribed to the minimized carrier thermalization loss and further improved light absorption. However, the design of triple-junction solar cells often involves sophisticated multiple layer deposition as well as substantial optimization. Therefore, there is a lack of successful demonstrations of triple-junction solar cells outperforming the double-junction counterparts. To solve the incompatible issues related to the layer deposition in the fabrication, we proposed a novel architecture of inverted-structure tandem solar cells with newly designed interconnecting layers. Our design of interconnecting layers does not only focus on maintaining the orthogonal solution processing advantages, but also provides an excellent compatibility in the energy level alignment to allow different absorber materials to be used. Furthermore, we also explored the light management inside the double- and triple-junction tandem solar cells. The study of light management was carried out through optical simulation method based transfer matrix formalism. The intention is to obtain a balanced photocurrent output from each subcells inside the tandem solar cell, thus the minimal recombination loss at the contact of interconnecting layers and the optimal efficiency can be expected. With help from simulations, we were able to calibrate the thickness of each photoactive layer as well as the thickness of interconnecting layers to achieve the optimized processing conditions. With the highest power conversion efficiency, 11.5%, triple-junction tandem solar cells outperform the double-junction tandem solar cells at 10.5%. In summary, this dissertation has provided practical solutions to the current demand of high-performance and easily manufactured organic solar cells from the solar cell industry. Particularly, triple-junction tandem solar cells with efficiencies over 11% should have great potential to contribute to high-efficiency solar-cell applications, whereas semi-transparent tandem solar cells with efficiency at 7% should be applicable to building-integrated applications.

Polyomaviruses are small, DNA tumor viruses that establish persistent infections in their natural hosts. Several members of the virus family are associated with human pathologies such as Progressive Multifocal Leukoencephalopathy (PML), trichodysplasia spinulosa and Merkel cell carcinoma. Polyomaviruses are one of the first virus family known to encode miRNAs. These polyomaviral miRNAs are located antisense to the early transcripts and hence, mediate the autoregulation of the viral early proteins, the T antigens. There are two major questions in the field of polyomaviral miRNAs – What is the biological significance of this miRNA-mediated autoregulation of the early transcripts? Are there other biological significant targets for these polyomaviral miRNAs? This work addressed these two questions through an evolutionary approach. First, examination of SV40 and JCV variants indicated the high conservation of the miRNAs and their autoregulatory functions. Second, miRNA-mediated autoregulation of the early transcripts is conserved in a newly discovered, evolutionarily divergent viruses, the Bandicoot papillomatosis and Carcinomatosis viruses (BPCVs). Third, by inspecting divergent members of the polyomavirus family, we have shown that some non-human polyomaviruses encode miRNAs, with the function to autoregulate the early transcripts conserved. The conservation of miRNAs both among variants of individual member and across divergent members of the polyomavirus family implies importance. More importantly, a conserved function of autoregulating the early transcript further emphasized the biological relevance of the miRNAs in polyomavirus biology. Yet, the lack of replicative differences between miRNA-expressing and miRNA-null SV40 strains during lytic infections suggests a role for the polyomaviral miRNAs under a different setting, perhaps in the establishment of persistent infection of their natural hosts. This work represents an evolutionary study of polyomaviral miRNAs that has demonstrated the conserved nature of miRNA-mediated autoregulation of the early transcripts among various members of the polyomavirus and polyoma-like virus families. These results have implicated a potential role for the polyomaviral miRNAs in the establishment of persistent infection and raised the possibility of using the JCV miRNAs as potential biomarkers as a non-invasive form of diagnostic for PML.

As a robust system, cells can wisely choose and switch between different signaling programs according to their differentiation stages and external environments. Cancer cells can hijack this plasticity to develop drug resistance. For example, breast cancers that are initially responsive to endocrine therapy often develop resistance robustly. This process is dynamically controlled by interactions of genes, proteins, RNAs and environmental factors at multiple scales. The complexity of this network cannot be understood by studying individual components in the cell. Systems biology focuses on the interactions of basic components, so as to uncover the molecular mechanism of cell physiology with a systemic and dynamical view. Mathematical modeling as a tool in systems biology provides a unique opportunity to understand the underlying mechanisms of endocrine response and resistance in breast cancer. In Chapter 2, I focused on the experimental observations that breast cancer cells can switch between estrogen receptor α (ERα) regulated and growth factor receptor (GFR) regulated signaling pathways for survival and proliferation. A mathematical model based on the signaling crosstalk between ERα and GFR was constructed. The model successfully explains several intriguing experimental findings related to bimodal distributions of GFR proteins in breast cancer cells, which had been lacking reasonable justifications for almost two decades. The model also explains how transient overexpression of ERα promotes resistance of breast cancer cells to estrogen withdrawal. Understanding the non-genetic heterogeneity associated with this survival-signaling switch can shed light on the design of more efficient breast cancer therapies. In Chapter 3, I utilized a novel strategy to model the transitions between the endocrine response and resistance states in breast cancer cells. Using the experimentally observed estrogen sensitivity phenotypes in breast cancer (sensitive, hypersensitive, and supersensitive) as example, I proposed a useful framework of modeling cell state transitions on the energy landscape of breast cancer as a dynamical system. Grounded on the most possible routes of transitions on the breast cancer landscape, a state transition model was developed. By analyzing this model, I investigated the optimum settings of two intuitive strategies, sequential and intermittent treatments, to overcome endocrine resistance in breast cancer. The method used in this study can be generalized to study treatment strategies and improve treatment efficiencies in breast cancer as well as other types of cancer.

Analogs of naturally occurring nucleosides have served as structural models for the design of antitumor, antiviral, and antibacterial agents. The carbocyclic nucleosides aristeromycin and neplanocin A are two examples that show significant broad-spectrum antiviral activity. The significant antiviral properties of these two nucleosides have been attributed to inhibition of AdoHcy hydrolase, which in turn affects viral mRNA capping methylation. However, their clinical potential is limited by toxicity, which is associated with phosphorylation of the primary hydroxyl group at 5′ position. 3-Deazapurine carbocyclic nucleosides (3-deazaneplanocin A and 3-deazaaristeromycin) have been shown to retain antiviral activity with significant reduction of toxicity as a result of their incapability of undergoing phosphorylation. In the search for effective antiviral agents, fluorinated nucleosides and nucleotides, where the fluorine has been introduced into both the base and the sugar moiety, have found use in the treatment of viral infections. The placement of a fluorine atom can have significant effects on a biological molecule due to imparting increased lipophilicity, powerful electronic effects and altered metabolic properties. To further explore new antiviral agents retaining 3-deazaaristeromycin-based activity while reducing undesired toxicity, modification at the C-3′ and C-2′ position have been recognized as important means to promising compounds. The synthesis and biological properties of the 3′-fluoro-3′-deoxy- and 2′-fluoro-2′-deoxy-3-deazaaristeromycin derivatives 1, 2, 4 and 5 have been investigated. As a logical extension of the 3′-deoxy- and 2′-deoxy-3-deazaaristeromycin derivatives 3 and 6 has been identified as important target. 4′-Substituted nucleosides were found to exert potent activity against HIV. In this dissertation, the 4′-methyl-3-deazaaristeromycin (7) was sought as an anti-HIV agent and an efficient route into the heretofore unknown 4′-alkylated-3-deazaaristeromycin framework was developed. The bioassays for all compounds will be forthcoming and under study.

In this thesis, I have developed a piezoelectric-actuated micro-fluorescence-activated cell sorter ([Mu]FACS) and demonstrate its performances using various biological samples including mammalian cell and bacteria. Three major developments in this work included a high-sensitivity detection system, fast-response on-chip piezoelectric cell sorting module, and system integration. In my early work, optical arrayed waveguides combined with cross-correlation signal processing algorithm are implemented to achieve high-sensitivity scattering detection. The insight gained from the algorithm further allowed me to design and implement a spatial-filter based (space-time coding) fluorescent detection system. The system enables not only signal amplification (228}018 dB SNR enhancement) but also sorting even verification, allowing real-time optimization of sorting parameters. The first generation on-chip cell- sorting module involves flow-redirection using the principle of nozzle-diffuser, but due to the periodic flow and high fluid disturbance resulted from high-voltage piezoelectric actuation, the sorting module was redesigned, resulting in piezoelectric-actuated cell sorting module. The inexpensive module was able to manipulate single cells at high rate (> 1000 cells/s) under low powered actuation (< 10 mW and < 10 Vp-p). Integration of detection and sorting systems is achieved through the implementation of the preprogrammed FPGA-embedded external driver enables closed-loop control for triggering fluorescence-activated cell sorting. With the sorting event verification capability, sorting efficiency was found to be > 80%. Sample enriching experiments were done using beads and human mammalian cells, showing an enrichment factor > 200 fold (comparable to commercial FACS), which is the highest among [Mu]FACS systems. The developed integrated [Mu]FACS was also applied to address the challenges (detection sensitivity and cell-free DNA contamination) commonly encountered in single-cell genome sequencing. Flow cytometry-modified Tyramide Signal Amplification Fluorescence in situ Hybridization (TSA-FISH) and two-step optofluidic light confinement were implemented to enhance sensitivity. Also, dual-round cell-free DNA purification was performed and compared to commercial FACS, showing comparable results. Sorting of rare bacteria was achieved, showing 223-fold enrichment. I hope the work sets the benchmark for the future development of [Mu]FACS systems. I believe the realization of a truly hand-held [Mu]FACS that can be afforded by every research labs and clinics is not far off

In this study, litmus and colorimetric tests were developed to quantify the contents of amine-based antistrip additives in asphalt binders and mixes. In addition, the effect of prolonged heating on antistrip additive content was evaluated for both asphalt binders and mixes. Results of this study indicate that both litmus and colorimetric tests are capable of detecting and quantifying amine-based antistrip additives in asphalt binders and mixes. Also, both test methods were able to validate the antistrip additive contents in field samples with known additive contents. When subjected to prolonged heating periods, the antistrip additive content decreased substantially for both asphalt binders and mixes. For asphalt binders, no antistrip additive content was detectable after 24 to 48 hours of extended heating; for mixes, the measured antistrip additive content approached non-detectable level after 6 to 12 hours of extended heating. Tensile Strength Ratio test was conducted in this research to evaluate the effect of prolonged heating on the asphalt-aggregate bond strength of hot mix asphalt (HMA) containing liquid antistrip additives. Improvement of moisture sensitivity by use of amine-based antistrip additive was observed to be lost to a great extent after prolonged heating. It shows that the remaining part of antistrip additive after prolonged heating has reduced effect on adhesion between asphalt and aggregate. The volatilization and⁄or chemical change that occur during the heating process of amine-based antistrip additive affect the improvement of asphalt-aggregate adhesion and ultimately the moisture susceptibility of mixes.

This research advances the state-of-the-art micro-hole EDM drilling. Sub-ns monitoring and analysis of EDM pulses, adaptive fuzzy logic EDM process control and its application on deep and small diameter micro-hole EDM drilling, form measurement of micro-holes and gage R&R study, and the multi-stage EDM drilling for negative tapered micro-holes are developed. Monitoring the gap voltage and current in micro-hole EDM with 0.5 ns sampling period is conducted and a new phenomenon of pre-discharging current, an extremely short duration of current rise (20 to 30 ns) before the voltage drops for discharging, is discovered. A model based on the RLC circuit is developed to study the ringing effect, the voltage oscillation occurring at the end of discharges. An adaptive fuzzy logic controller using average gap voltage, deviation of spark ratio, and change of deviation of spark ratio as input parameters is developed in this research. Two commercial micro-hole EDM machines are selected as platforms for the implementation and validation of this fuzzy logic controller, which is then compared with the existing controllers, using pulse width modulation (PWM) and gain scheduling, of the two platforms. Experimental results show that the fuzzy logic controller can generate more stable and consistent EDM drilling process and is more adaptive to different EDM configurations, such as deep (2.3 mm thick workpiece with 150 mum diameter electrode) and small diameter (75 mum diameter electrode with 1.14 mm thick workpiece) micro-hole EDM drilling. The form measurement of micro-holes and the gage repeatability and reliability (R&R) test are conducted in this research using a multi-sensor coordinate measuring machine (CMM). Capable tolerance specifications for micro-holes, derived from the gage R&R study, are valuable for product engineers to specify tolerances for measurable micro-holes and for metrology engineers to further improve the gage capability. At last, a multi-stage micro-hole EDM drilling technique is developed in this research to produce negative tapered micro-holes. This new EDM drilling technique can effectively and consistently fabricate 1.14 mm deep negative tapered micro-holes with inlet and outlet diameter difference larger than 15 mum.

Rhamnolipids causes severe foaming during its production by conventional aerobic fermentation of Pseudomonas aeruginosa. This problem necessitates the reduction of aeration, which in turn limits the cell concentration employable and productivity achievable in the process. As a continual work to the previous study conducted by Chayabutra and Ju [162], a mixed-mode operation of aerobic and anaerobic fermentation was examined for its potential to minimize foaming and for its related problems when implemented rhamnolipid production. The key factors investigated in this study included: [1] the method for nitrate delivery that would minimize the inhibitory or toxic effects of high nitrate concentration on cell metabolism; [2] the phosphorous supplementation to maintain specific rhamnolipid productivity while cells were still growing; and [3] the effects of quorum sensing systems, a nature population control mechanism, on cell growth and rhamnolipid production. It was found that in the micro-aerobic process, amixed solution of sodium nitrate and nitric acid could be used to meet cell respiration needs and support cell growth to a relatively high concentration (> 10 g/L). A 5-fold increase in cell concentration was achieved in this study when compared to the typical aerobic fermentation. According to the results from the phosphorous-limiting continuous cultureconducted in the study, high specific rhamnolipid productivity could be maintained when the specific cell growth rate was lower than 0.08 (h-1). It was also observed that, an early onset of stationary phase took place in the P. aeruginosa culture when there was no apparent nutrient limitation. The phenomenon was attributed to the effect of quorum-sensing systems of the bacterium. The rhl quorum-sensing system (involving rhlR and rhlI genes) was known to regulate cell growth and rhamnolipid production. The degradation and synthesis kinetics of the rhlI gene-derived product, an autoinducer, were therefore evaluated in this study. The autoinducer was found to be unstable in the fermentation broth and its degradation could be empirically described with a first-order decay kinetics. To maintain the maximal rhamnolipid productivity, at least 13% of the peak autoinducer concentration (v/v) needs to be added in the fermentation broth in the beginning. The micro-aerobic rhamnolipid fermentation overcomes foaming problem, that retards the productivity achievable and market applicables. The autoinducer degradation and synthesis kinetics could have a medicinal application through the development of a stable autoinducer analogue to control the population of P. aeruginosa that could cause death rate in the hospitals.

This study provides a detailed description and analysis of phonology of two Formosan languages and further compares the phonological constraints and prosodic structures in the languages. Formosan languages, nearly half of which have become extinct in the past two centuries, are the aboriginal languages of Taiwan. They belong to the Austronesian language family. Paiwan and Budai Rukai were selected for their geographical distribution and genetic classification. None of the existing field reports bear on both systemic phonetics and phonology of Formosan languages. Accentual patterns from Formosan languages have become essential for the reconstruction of Proto-Austronesian stress. In this study, segmental phonology, phonetic representations of consonants and vowels, sound change, and prosodic structures such as word stress, phrasal stress, word-level pitch accent, and sentence-level intonation of Paiwan and Budai Rukai were documented, analyzed, constructed and compared. The distribution of pitch accent in imperative construction and face-to-face interaction has shown the significance of prosody in Paiwan. Boundary tones are important indices for the syntactic types of sentences in Paiwan. On the other hand, vowel length is phonemic, and syllable weight does affect the assignment of stress in Budai Rukai. The interaction between vowel length at penult and stress patterns in Budai Rukai has provided evidence for the argument of contrastive stress in the Proto-Austronesian language. The dissertation has provided two more indicators in Formosan languages that reflect the contrastive stress in Proto-Austronesian roots: syllable extrametricality in Budai Rukai and final stress subject to schwa penult in Central Paiwan. The documentation of prosodic patterns has become a prerequisite for the preservation of ancestral accent of the indigenous languages. Historical reconstruction of cognates and synchronic phonological features have provided evidence for the proposal that the innovations shared by Paiwan and Budai Rukai are due to recent contact.

The primary purpose of this study is to identify the 'universal' rate formulations with scaled-dependent parameters for the biological reduction of hematite. Three possible rate formulations were proposed to describe the bioreduction rate of hematite, and two kinds of simulation were conducted to validate the formulations and parameters with both batch and column experimental data: a reaction-based biogeochemical (batch) modeling with BIOGEOCHEM 1.0 and a reactive biogeochemical transport (column) modeling via HYDROGEOCHEM 4.0. Based on the results of simulations, only the dual Monod kinetic with inhibition rate formulation with respect to the concentrations of lactate, ßFeOOH, and Fe2+ under certain initial concentration of dissimilatory metal-reducing bacterium could fit the experimental data well. Our results also revealed that the equilibrium reaction rate for the surface hydration of hematite may have to be substituted with the kinetic rate formulation.

This dissertation contests indiscriminate valorization of "difference" and its cognates in postcolonial discourse by shifting attention to the ontological "impossibility of difference" of postcoloniality and to the ethical demand born of such an ontological consideration. The study begins with an analysis of Charles Baudelaire's treatment of the ethos of sameness in his lesbian poems. My argument is that at a time when the conceptualization of difference is assuming formative importance in modernity's political philosophy, cultural imaginary, and epistemology, Baudelaire's work is already undermining the Self-Other demarcation. The reason for my extending the scope retroactively to European modernity is that Baudelaire's time, as I view it, marks a historical juncture where the Self-Other dynamic begins to materialize a certain episteme by assuming a material "content." Then, spanning the work of writers from a wide range of areas including Salman Rushdie (Indian British), Theresa Hak Kyung Cha (Korean American), and Dancing Crane (Taiwanese), this study examines, in particular, the way in which these writers approach the impossibility of difference by problematizing the concept and praxis of writing. That is, writing assumes a quasi-ontological status and functions as the site where the postcolonial subject materializes his/her conception of "community." The governing argument of the study is that the singular reliance on the singularized Self-Other model in the construction of postcolonial theory risks neglecting the relationship between the self and the collective, which too constitutes a crucial portion of the subject's ethico-political experience. Secondly, since the Self-Other model is conventionally premised on a power relation, sanctification of this model as the prominent language in postcolonial theory risks losing sight of postcolonial theory's own limitations, especially the confinement of political idioms. I argue that to consider postcoloniality in light of "community" is to configure postcoloniality not merely as a historical juncture but as a futurist episteme anticipating an emancipatory agenda that can break out of the dilemma of the idiom of difference and difference-driven identity politics. Theorists discussed in this study include Walter Benjamin, Jacques Derrida, Jean-Luc Nancy, and Emmanuel Levinas.

In this research, we primarily focus on the structure and function of both the nucleotide binding domain, and the full length membrane-spanning transporter. First, the soluble nucleotide binding domain of Atm1 (Atm1-C), an ABC transporter in yeast mitochondria, that has previously been implicated in the maturation of cytosolic iron-sulfur cluster proteins, has been overexpressed in E. coli, purified, and characterized. The full length version of Atm1 from Saccharomyces cerevisiae has been cloned, over-expressed, purified from a yeast expression system, and characterized. A fluorescent assay of liposome-loaded reconstituted Atm1p suggested that Atm1p only allowed small molecules and/or metal complexes to cross the channel. Both pH gradient and fluorescent assays also indicated that ADP-bound Atm1p existed in an open state that is different from the closed state for ATP-bound Atm1p. The further discovery of an iron carrying peptide, hepcidin, provides the first step toward understanding iron trafficking in living cells. With eight, well-conserved cysteine residues in the sequence, hepcidin may not only be a signal peptide, but could potentially serve as an iron carrier. The iron binding properties have been determined by UV-vis spectroscopy, mass spectroscopy, and isothermal titration calorimetry (ITC). The iron binding affinity has been determined in the micromolar range. Studies by circular dichroism (CD) reveal varying degrees of secondary structure within an apparent dynamic tertiary fold. Taken together, hepcidin clearly binds iron, and the secondary structure change induced by iron binding may be required for the full function of the peptide in iron homeostasis and antimicrobial activity. In Part II, a novel fluorescent assay has been developed for monitoring the cleavage of a target RNA by cooper kanamycin in vivo. However, demonstration of the efficacy of such reagents in vitro is only a first step. To demonstrate in vivo cleavage chemistry we have designed a fluorescence assay based on use of the green fluorescent protein (GFP). The decrease in fluorescent intensity indicated the designed target RNA being destructed. The success in this assay provided a novel tool for screening a large quantity of drug molecules for their targets at the same time.

This study examines whether the relationship between strategic human capital management practices (HCMPs) and employee capability is moderated by personnel control mechanisms, and whether the relationship between employee capability and corporate performance is affected by an intervening variable, customer loyalty, and whether efficient development and effective deployment of strategic HCMPs act as leading indicators of corporate performance. The possible moderating and intervening relationships among four constructs — strategic HCMPs, persormel control mechanisms, employee capability and customer loyalty — are considered. Propositions concerning the moderating and intervening relationships among these constructs are made, and a LISREL model of their relationships to business performance is specified.

Four commercial frying oils of different degrees of unsaturation, designated as AA, BB, CC and CC-P, were obtained from 3 frying outlets daily for 2 weeks in order to determine levels of degradation in fresh and used frying oils as measured by chemical and physical characteristics. Chemical measurements included fatty acid composition (C18:2/C16:0 ratio), iodine values (IV) and levels of total polar components (TPC), free fatty acids (FFA), peroxide values (PV), polymers (POL), conjugated dienoic acids (CDA), tocopherols (TOC) and flavor volatiles. Physical measurements included dielectric constant (FOS), viscosity (VIS) and oil color (ΔE). Correlation coefficients among chemical and physical characteristics were calculated. The best prediction equations using measured characteristics were determined for estimation of TPC as an indicator of oil degradation. IV in fresh oils were 74.1 for BB, 99.6 for CC, 102.7 for AA, and 108.4 for CC-P. Across 7-days frying, TPC, FFA, POL, FOS, CDA, VIS and ΔE generally increased and TOC, IV and C18:2/C16:0 ratio decreased. Nine volatile aldehydes were identified but not from all oils; the most abundant was t,t-2,4-decadienal. Level of each volatile was dependent upon compound, oil and sampling day. TPC, a reliable measure of frying oil deterioration, increased during 7-days frying from 4.8 to 16.9% in BB, 4.9 to 18.7% in CC and 2.7 to 27.6% in CC-P, and increased during 5-days frying from 5.8 to 16.9% in AA. The FFA in CC-P, which was in a steam pressure chicken fryer, increased from 0.05 to 6.15% during 7-days frying. FFA at 7-days frying in BB was 2.53% and in CC was 1.70%. TPC, FFA, FOS, and ΔE were highly correlated with one another (r ≥ 0.80). IV and the C18:2/C16:0 ratio also were highly correlated. POL was correlated with TPC (r = 0.57) and with VIS (r = 0.65), but VIS had a lower correlation with TPC (r = 0.30). Removing samples with FFA >3.0% from correlation calculations increased r to 0.60 between VIS and TPC showing that oil samples with high FFA affected that relationship. The best single variable model for TPC prediction included FOS (R2 = 0.88).

The reliability of two multiresidue methods (MRMs) for 11 organophosphates and N-methylcarbamate insecticides (INs) in 3 vegetables or VEGs (corn, navy beans and spinach) were determined and compared. MRM 1 involved acetonitrile extraction followed by florisil clean-up and MRM 2, ethyl acetate-acetone extraction and reverse phase C18 clean-up. INs were measured using an internal standard method and GC-MS selective ion monitoring (SIM). Reliability was determined by percent recovery (PR), coefficient of variation (CV) and sensitivity. The PR of each MRM was dependent upon IN, VEG and method. Each MRM was precise (

A method for signal synthesis model reference adaptive control

This study considers an infinite orthotropic plate on a frictionless elastic foundation subjected to a transverse point load. We are concerned with the stress distribution in the vicinity of the load application. Based on the assumption of a uniform stress distribution under the load, a Fourier Transform technique is utilized to formulate and solve the problem in the transform domain. The inverse transformation is carried out numerically, via the Gaussian Quadrature scheme, to obtain the real response. Symmetry of the transform response due to the material orthotropy has been used to reduce the effort involved in performing the integration. Results indicated a similar symmetric behavior for the real stress distribution, and satisfied the boundary conditions of the problem. The transverse equilibrium is also verified by summing up the reaction forces exerted by the foundation.

Three dimensional contact problems of square orthotropic laminates indented by a rigid spherical indenter are solved. Simplified problems of indentations of beam and isotropic square plate are studied first to develop an efficient numerical technique and to gather the knowledge of the shape of the contact area in order to solve for the three dimensional orthotropic cases. The approach combines an exact solution method in conjunction with a simple discretization numerical scheme. Numerical sensitivity due to the ill-posed nature of the problem was experienced but was cured by enhancing the numerical approach with a least square spirit. Well agreement is obtained by comparing the results of these simplified studies with available published solutions. For isotropic plate, contact area is found to be either a circle or a hypotrochoid of four lobes featured with a shorter length of contact along the through-the- corner directions of the plate. Hertz's theory fails earlier than assuming the contact area to be a circle. In-plane dependence of the contact stress is presented to illustrate the difference of contact behavior between a square plate and a circular plate. Load-indentation relation reveals indenting a square plate is harder than indenting a circular plate of a diameter equal to the side length of the square plate. Solutions of multi-layered orthotropic cases are achieved by employing a modified analytical approach with the same numerical method. Three different configurations of plate are implemented for the orthotropic case, namely, a single layered magnesium (Mg) plate, which is slightly orthotropic, and a single and double layered plates of graphite-epoxy (G-E), which are highly orthotropic. Results for the (Mg) plate agrees with the previous isotropic case. Concept of modifying the previous hypotrochoids is introduced to seek for the contact stresses for comparatively large indentation conditions. Single-layered (G-E) plate was implemented for small indentations. The result supports the validity of Hertz's theory for small indentation and shows a relatively longer contact length in the direction of less stiffness. Two layered (G-E) plate illustrates similar distributions for the contact stresses along both of the in-plane directions with a smaller range of validity of Hertzian type behavior than the previous cases. The boundary effect prevails at the initial stage of indentation but is overcome by the effect of material orthotropy as the indentation proceeds. Thus, the contact area for small indentation appears to be the same kind of hypotrochoids as located in the isotropic case but changes to be the other type of hypotrochoids as the indentation advances.

Hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) have been widely used in active-matrix liquid-crystal displays (AMLCDs) because they can be deposited over a larger area at low temperatures. However, there are two main disadvantages of a-Si:H TFTs: First, the low field-effect mobility of a-Si:H TFTs limits their application to high-definition and large-area AMLCDs. Second, the low deposition-rate of a-Si:H reduces the throughput of AMLCD manufacturing. Thus, there is an increasing need for a-Si:H TFT having high field-effect mobility, and made by high deposition-rate materials. For this purpose, a high performance a-Si:H TFT based on high deposition-rate materials was fabricated. This a-Si:H TFT has a high field-effect mobility (1.55 cm2/Vs), a low threshold voltage (1.2 V), and a sharp subthreshold slope (0.34 V/decade). Under A.C. bias-temperature-stressing testing, this TFT also shows good stability compared with low-rate deposited a-Si:H TFT. In order to further improve performance, we need to determine what kind of parameters limit a-Si:H TFT performance. For this purpose, an a-Si:H TFT model based on two-dimensional simulation was developed. The simulation program is based on the finite-element method and resolving Poisson's and continuity equations for electrons and holes. Thus the simulation is very suitable and flexible for a-Si:H TFT having high density of states and a thin semiconductor layer. Based on a two-dimensional a-Si:H TFT model, the influence of the density of states and source/drain series resistances on a-Si:H TFTs were analyzed. The simulation results indicate that the conduction-band-tail states mainly affect the a-Si:H TFT field-effect mobility and the non-linearity of current-voltage characteristics. When deep-gap state densities are larger than a certain critical value, they will mainly influence the threshold voltage. This critical value depends on the a-Si:H film thickness, and the thickness and dielectric constant of the gate-insulator. A new technique based on a gated-four-probe TFT structure was introduced for determining the intrinsic performance of a-Si:H TFT without any influence from series resistances. This new structure can also be used to accelerate the optimization process. Based on the simulation for a-Si:H TFT and gated-four-probe TFT structures, for a 10-$\mu$m-channel-length a-Si:H TFT, the source/drain series resistances cause the field-effect mobility to decrease by 43.8%. Of the total source/drain series resistances, contact resistances contribute 70%, and resistances associated with intrinsic a-Si:H and source/drain-gate overlap occupy 15% each. Thus, reduction of contact resistances is the key to achieving short-channel-length high performance a-Si:H TFTs.