Dissertations / Theses on the topic 'Residual charge'

Complex (dusty) plasmas are a subject of growing interest. They areionized gases containing charged dust particles. In capacitively-coupled RF discharges, dust growth can occur naturally and two methods can be used to grow dust particles: chemically active plasmas or sputtering. The growth of dust particles in argon discharges by RF sputtering and the effect of dust particles on theplasma have been investigated from the plasma ignition to the afterglow. It was shown that plasma and discharge parameters are greatly affected by the dust particles. Furthermore, plasma instabilities can be triggered by the presence of the dust particles. These instabilities can be due to dust particle growth or they can be instabilities of a well established dust cloud filling the interelectrode space. When the discharge is switched off, the dust particles act like a sink for the charge carrier and consequently affect the plasma losses. It was shown that the dust particles do keep residual chargeswhich values are greatly affected by the diffusion of the charge carriers and especially the transition from ambipolar to free diffusion.

Doctor of Philosophy(PhD)
Complex (dusty) plasmas are a subject of growing interest. They areionized gases containing charged dust particles. In capacitively-coupled RF discharges, dust growth can occur naturally and two methods can be used to grow dust particles: chemically active plasmas or sputtering. The growth of dust particles in argon discharges by RF sputtering and the effect of dust particles on theplasma have been investigated from the plasma ignition to the afterglow. It was shown that plasma and discharge parameters are greatly affected by the dust particles. Furthermore, plasma instabilities can be triggered by the presence of the dust particles. These instabilities can be due to dust particle growth or they can be instabilities of a well established dust cloud filling the interelectrode space. When the discharge is switched off, the dust particles act like a sink for the charge carrier and consequently affect the plasma losses. It was shown that the dust particles do keep residual chargeswhich values are greatly affected by the diffusion of the charge carriers and especially the transition from ambipolar to free diffusion.

Die vorliegende Dissertation befasst sich mit der ramanspektroskopischen Charakterisierung von Galliumnitrid (GaN). Der Zusammenhang zwischen Waferkrümmung und mechanischer Restspannungen wird diskutiert. Mit Hilfe konfokaler Mikro-Ramanmessungen wurden Dotierprofile nachgewiesen sowie die Ladungsträgerkonzentration und -beweglichkeit ermittelt. Sämtliche Ramantensorelemente von wz-GaN wurden erstmals durch die Anwendung verschiedener Streugeometrien bestimmt. Eine neu entwickelte Vorwärtsstreuanordnung ermöglichte die Beobachtung von Phonon-Polaritonen. Es konnte gezeigt werden, dass von der theoretischen und experimentellen Betrachtung der Ramanstreuintensitäten dieser Elementaranregungen eindeutig das Vorzeichen der Faust-Henry-Koeffizienten von wz-GaN abgeleitet werden kann. Im Rahmen dieser Arbeit wurden alle Faust-Henry-Koeffizienten für GaN experimentell bestimmt
This thesis focuses on special aspects of the Raman spectroscopical characterization of wurtzite gallium nitride (wz-GaN). The correlation between wafer curvature and residual stress is discussed. By means of confocal micro-Raman measurements doping profiles were detected as well as the density and mobility of free charge carriers were deduced. All Raman scattering cross sections of wz-GaN were determined the first time using different scattering configurations. A novel method for near-forward scattering was developed in order to observe phonon polaritons with pure symmetry. It is shown that the theoretical and experimental consideration of the Raman scattering efficiency of these elementary excitations allow for determining the sign of the Faust-Henry coefficients of wz-GaN unambiguously. The Faust-Henry coefficients of GaN were deduced from Raman scattering efficiencies of corresponding TO and LO phonons

The Electrical Functional Stimulation (EFS) allows the direct connection between man and machine through electrical signals. The last years growth in EFS is possible because of the new technological resources that make it feasible. Restoring someone s vision or hearing, even parcially, is one among several contribution that EFS may contribute to human s well-being. However the interface between the electrical circuits and the tissue is sensitive to several factors. Among several effects that may damage the tissue and electrode in EFS we can find those caused by the electrical stimuli, this may harm the application. This work presents contributions regarding electrical circuits topologies for safety stimuli in EFS. It is essential to ensure proper electrical charge balance and a small residual voltage on the tissue-electrode interface. For each of these problems one proposal is presented, both share circuit blocks. The blocks to control intensity and polarity of stimuli are designed to avoid the integration of high voltage devices. The current mode stimuli is generated using an ultra-low power charge redistribution Digital to Analog Converter (DAC) for stimulus intensity definition. This DAC architecture even simplifies the feedback mechanism that is obtained directly from measurement circuit. The technic that uses only low voltage devices to measure electrodes current is presented, it is suitable to implement the charge balance control in an integrated circuit. This measurement technique is insensitive to capacitors mismatch and to the current measurement absolute ratio. That control is possible through the a simplified feedback path that joins the controller and the measurement in an efficient way acting directly in the DAC. The proposed residual voltage control technique requires only passive elements to be added to the circuit, that suggest a lower power consumption. The charge redistribution DAC keeps residual voltage information stored, in order to compensate it in next stimulation cycles. The stimulation cycle polarity is explored, alternated cathodic and anodic-first cycles are used in order to reduce the charge imbalance and residual voltage. Both proposals are presented and validated with electrical simulation, known metrics are used and the performance is equivalent to state-of-art in literature.
A estimulação elétrica funcional(EFS) faz a interface direta entre o homem e a máquina, por meio de sinais elétricos. A viabilidade advinda de novas tecnologias justifica o seu crescimento nos últimos anos. Restaurar a visão ou a audição, mesmo que parcialmente, são duas das inúmeras contribuições que pode proporcionar para o bem estar do ser humano. No entanto, a interface entre o circuito elétrico e o tecido é sensível a diversos fatores. Entre os diversos fenômenos que podem ocasionar danos ao tecido e ao eletrodo na interface de EFS estão os causados pelo estímulo elétrico usado, e isso pode inviabilizar a aplicação. Neste sentido, este trabalho apresenta contribuições relacionadas à topologia de circuitos para segurança na geração do estímulo em EFS. O correto balanceamento de carga elétrica e a diminuição da tensão residual, na interface entre o tecido e o eletrodo, são indispensáveis. Uma técnica é propostas para a solução de cada um desses problemas, ambas compartilham blocos de circuito comuns. O controle da intensidade e da polaridade de estimulação são concebidos para evitar a necessidade de dispositivos de alta tensão. A geração de estímulos em modo corrente utiliza um Conversor Digital para Analógico (DAC) do tipo redistribuição de carga de ultra baixo consumo de energia para o controle da intensidade dos pulsos. Esse conversor ainda simplifica a realimentação, que é derivada diretamente do circuito de medição. Como solução para viabilizar a implementação em circuito integrado de controle do desbalanço de carga, uma técnica de medição usando somente dispositivos de baixa tensão é apresentada. Essa técnica é tolerante ao descasamento entre capacitores utilizados e à variação no ganho do circuito de medição de corrente. O controle é possível por meio de um laço de realimentação simplificado, que une medição e controle de forma eficiente e atua direto no DAC. A técnica proposta para controle da tensão residual nos eletrodos requer somente adição de elementos passivos ao circuito, sugerindo a redução do consumo de energia. O DAC tipo redistribuição de carga é usado para armazenar a informação da tensão residual e a compensação no ciclo seguinte. A fase dos ciclos de estimulaçãotambém é explorada, ciclos com fases alternadas são usados visando redução no desbalanço de carga e tensão residual. As duas propostas são apresentadas e validadas por meio da simulação elétrica, métricas conhecidas são utilizadas e o desempenho observado é equivalente ao estado da arte.

Le projet piafe consiste a produire des noyaux riches en neutrons par fission au sein d'une cible d'uranium placee pres du cur du reacteur de l'institut laue langevin, puis de transporter les produits de fission sous forme monochargee et a basse energie (inferieure a 30 kev) sur une distance de 400 m jusqu'au complexe accelerateur sara de l'institut des sciences nucleaires de grenoble. Une solution originale de guidage ayant ete proposee, l'objectif de cette these est de prouver la faisabilite d'un tel transport. Pour ceci, on s'est attache a etudier les effets sur le faisceau des defauts d'alignement des elements optiques (et de leur support) et du champ magnetique terrestre afin de determiner un systeme periodique de correction de la trajectoire centrale du faisceau. Puis, la realisation d'une ligne experimentale de 18 m a permis de faire une etude detaillee de l'interaction du faisceau avec le gaz residuel. Cette interaction se caracterise par les pertes de particules par echange de charge et l'augmentation d'emittance par diffusion coulombienne. La validation des modeles theoriques permet une extrapolation des phenomenes sur une distance de 400 m. Il est ainsi possible de conclure sur la faisabilite d'un tel transport

For a long time, there has been a need and an ambition to better understand the behavior of integrated systems by considering the whole urban water cycle, including wastewater transportation, wastewater treatment and the receiving water. On the other hand, fragmented environmental policies on wastewater sanitation, global change, and emerging contaminants are increasingly threatening freshwater ecosystems and human health. Within this context, this thesis embeds a series of research studies aiming to improve our comprehension of the functioning of urban wastewater systems (UWWS), considering both natural and artificial elements, and with a special emphasis on the occurrence of global change and on the fate of emerging contaminants. In the thesis, an integrated model for a UWWS in NE Iberian Peninsula has been developed and calibrated using data from an intensive and integrated survey, not only combining early developed mathematical models for the different sub-processes, but also verifying the model parameters with full-scale and dynamical measurements. More specifically, the work developed in this thesis was divided into three parts. First, we investigated how an UWWS perform together in the removal of conventional contaminants and evaluated the impact of future global change scenarios. Second, we investigated the occurrence and fate of pharmaceuticals and their transformation products in the UWWS. Finally, and as a continuation of the second work, we assessed the influence of the sampling strategy when estimating the loads and attenuation of emerging contaminants in UWWS under different scenarios differing from sampling strategies, consumption, and degradability of the compound under analysis. Overall, this thesis highlights the need for integrated approaches to better understand the performance of WWTPs and their receiving rivers, against the increase of micro-contaminants occurrence and the effects of global change
La necessitat i ambició per entendre millor el comportament dels sistemes de sanejament d’aigües residuals de forma integrada és una de les prioritats en la gestió de l’aigua, des de el transport, tractamet i descarrega als seus medis receptors. Per altra banda, les actual polítiques segmentades en la gestió dels sistemes de sanejament d'aigües residuals urbanes, el canvi global i l'ocurrència de contaminants emergents en els mitjans receptors, amenacen cada vegada més els ecosistemes d'aigua dolça i salut humana.En aquest sentit, aquesta tesi integra una sèrie d'estudis d'investigació que apunten a millorar la nostra comprensió en el funcionament dels sistemes d'aigües residuals urbanes (UWWS), considerant el conjunt d'elements naturals i artificials, i amb un èmfasi especial en els canvis globals i ocurrència dels contaminants emergents. Concretamemt. en aquesta tesi s'ha desenvolupat i calibrat un model integrat per a un UWWS al NE de la Península Ibèrica, utilitzant dades recollides durant intensa campanya integrada de monitorització, no només combinant avançats models per els diferents sub-processos, sinó també verificant els paràmetres de modelització amd dades dinàmiques i a escala. Més específicament, el treball desenvolupat en aquesta tesi s’estructura en tres parts. Primer, investiguem com funcionen els UWWS en l'eliminació de contaminants convencionals i avaluem l'impacte dels futurs escenaris de canvi global. Segon, avaluem l'ocurrència i la destinació dels productes farmacèutics i els seus productes de transformació en el UWWS. En tercer lloc, i com a continuació d'aquest segon treball, s’estudia la influència de diferents escenaris de mostreig, consum i degradabilitat dels compostos en l’estimació de càrregues i atenuació dels micro-contaminants en UWWS.En general, aquesta tesi destaca la necessitat d'enfocaments integrats per comprendre millor el rendiment de les EDAR i els seus rius receptors, per prendre mesures contra l'augment de les concentracions de micro-contaminants i els efectes del canvi global

The IFMIF accelerator will accelerate two 125mA continuous wave (cw) deuteron beams up to 40MeV and blasts them onto a liquid lithium target to release neutrons. The very high beam power of 10MW pose unprecedented challenges for the accelerator development. Therefore, it was decided to build a prototype accelerator, the Linear IFMIF Prototype Accelerator (LIPAc), which has the very same beam characteristic, but is limited to 9 MeV only. In the frame of this thesis, diagnostics devices for IFMIF and LIPAc have been developed. The diagnostics devices consist of beam loss monitors and interceptive as well as non-interceptive profile monitors. For the beam loss monitoring system, ionization chambers and diamond detectors have been tested and calibrated for neutron and γ radiation in the energy range expected at LIPAc. During these tests, for the first time, diamond detectors were successfully operated at cryogenic temperatures. For the interceptive profilers, thermal simulations were performed to ensure safe operation. For the non-interceptive profiler, Ionization Profile Monitors (IPMs) were developed. A prototype has been built and tested, and based on the findings, the final IPMs were designed and built. To overcome the space charge of accelerator beam, a software algorithm was written to reconstruct the actual beam profile.

The loss-of-function mutations in the human ether-à-go-go–related gene (hERG) K+ channel serve as one of the primary genetic substrates for congenital long QT syndrome (LQTS), and unlike most Kv channels with fast-activating kinetics, hERG channels have unusually slow activation kinetics. Thus, it is a necessary task to understand mechanisms of hERG gating, especially since the charge-rich S4 segments play such an important role in channel opening in response to membrane potential changes. Despite the structural homology to other Kv channels, how individual S4 charges in hERG are positioned and moved under the influence of membrane voltage changes remains controversial. Therefore, this thesis focuses on the molecular basis of individual charge residues underlying S4 movement. To monitor S4 movement associated with the voltage- and time-dependence accessibility by the sulfhydryl-specific agent MTSET, we mutated a series of S4 charges (K525-K538) to uncharged glutamine (Q) in a mutant in which cysteine replaced the isoleucine at position 521 near the top of S4. We found that K525, R528, and R534 mainly secure the S4 position in the resting state. Our results on the rate of S4 movement suggest that R528, R531, and R537 potentially facilitate the transition of S4 from the closed to the active state. Conversely, neutralization of the bottom lysine K538 significantly accelerates the rate of S4 movement, implying an important constraint on S4 by K538. To further investigate this unique role of K538, we measure the gating charge contributions of K538 and D411 (a potential ion-pairing in S1) with the cut-open vaseline gap technique. Our data show that mutations of both charges to neutral residues (K538Q and D411N) accelerate the time dependence of charge movement while both mutant channels are gated with faster kinetics than control over a physiologically relevant range of depolarizations. This highlights the substantial contribution of both residues to slow hERG gating.
Medicine, Faculty of
Anesthesiology, Pharmacology and Therapeutics, Department of
Graduate

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O objetivo deste trabalho é fazer uma modelagem numérica por elementos finitos de tensões residuais em peças de liga ferro-níquel e aço carbono submetidas a tratamentos térmicos,considerando mudanças de fase.Com este objetivo, foram desenvolvidos códigos computacionais orientados a objetos para análise térmica não-linear acoplado à análise da micro-estrutura. Códigos implementados em POO também foram criados para análise elasto-plástica, onde a distribuição de temperatura e as frações parciais dos constituintes são dados de entrada. As propriedades termo- mecânicas do material são consideradas dependentes tanto da temperatura quanto da fração parcial de cada constituinte. No tratamento térmico está sendo considerado a formação de martensita segundo o esquema de Koistinen e Marburger (1959). É abordado também a formação difusional de perlita e bainita, segundo o esquema proposto por Avrami (1939). Por fim, é apresentado um novo modelo para calcular os parâmetros cinéticos das transformações difusionais austenita-perlita e austenita-bainita.
The objective of this thesis is to perform a finite element analysis of residual stress in Fe-Ni alloys and carbon steel heat-treated pieces, considering phase changes. To achieve this goal, a object oriented computer code for the non-linear thermal analysis coupled with a code for a micro-structural analysis were developed. OPP codes were also created for an elasto-plastic analysis, with temperature distribution and constituents partial fraction as input data. The material properties are considered dependent on both the temperature and the partial fraction for all analyses.In the thermal treatment, the martensite transformation according to Koistinen and Marburger (1959) scheme and the diffusional formation of pearlite and bainite according to Avrami (1939) are considered. Finally, a new model to calculate the kinetics parameters of the diffusional austenite-pearlite and austenite-bainite transformations is presented.

Historical change in the geomorphology, hydrodynamics, and surficial sediment of the tidal delta system of Tauranga Harbour are investigated with the general aim of analysing The general aims of this thesis are: firstly to analyse historical changes to inlet delta system geomorphology using historical hydrographic charts, secondly, to conduct hydrodynamic numerical modelling using historical bathymetries to access changes in peak spring flow and potential net tidal sediment transport, and thirdly, to analyse historical changes in surficial sediment and bedforms. Geomorphic change was investigated through plotting difference in bathymetry graphs and conducting cross sections taken from digisitied bathymetries obtained from historical hydrographic charts from 1852, 1879, 1901, 1927, 1954 and a modern bathymetry from 2006. Two-dimensional hydrodynamic numerical modelling was conducted to investigate the changes in peak tidal current flow and potential net sediment transport between 1852 and 2006. Changes in surficial sediment patterns were determined through completing a side scan sonar survey with associated sediment samples for ground truthing of grain size and underwater videography to gather surficial shell coverage information. This was used to produce a surficial sediment coverage map which was compared to historical studies Major geomorphological findings include that the shipping channel appears to have induced minor change in the geomorphology of the FTD but such changes are similar to those identified in the historical bathymetries of 1852, 1879, 1901, 1927, 1954 prior to dredging. Significant changes have occurred on the ETD, with the majority of the ETD showing scour of 1 m while the terminal lobe has extended seawards. This is associated with historical (since 1852) narrowing of the inlet from Panepane Point to Mt Maunganui by ~ 900 m. Hydrodynamic numerical modelling has shown a significant increase in potential net tidal sediment transport in the Cutter Channel due to dredging, while the Maunganui Roads Channel shows a reduction of net potential tidal sediment transport that is associated with the dredging of this channel. The area surrounding Panepane Point undergoes significant increases and decreases in net potential tidal sediment transport both before and after dredging Investigation of the surficial sediment patterns over the FTD and ETD from sidescan sonar and bottom samples show that between 1983 and 2007 there has been a northwards extension of the area of major shell (greater than 50 %) converge in the main ebb channel as well as reduction in major shell converge in flood tidal delta ebb shield region. The Maunganui Roads Channel changes from sitly sands to medium and fine sands.

Three classes of structural change tests (or tests for parameter instability) which have been receiving much attention in both the statistics and econometrics communities but have been developed in rather loosely connected lines of research are unified by embedding them into the framework of generalized M-fluctuation tests (Zeileis and Hornik, 2003). These classes are tests based on F statistics (supF, aveF, expF tests), on OLS residuals (OLS-based CUSUM and MOSUM tests) and on maximum likelihood scores (including the Nyblom-Hansen test). We show that (represantives from) these classes are special cases of the generalized M-fluctuation tests, based on the same functional central limit theorem, but employing different functionals for capturing excessive fluctuations. After embedding these tests into the same framework and thus understanding the relationship between these procedures for testing in historical samples, it is shown how the tests can also be extended to a monitoring situation. This is achieved by establishing a general M-fluctuation monitoring procedure and then applying the different functionals corresponding to monitoring with F statistics, OLS residuals and ML scores. In particular, an extension of the supF test to a monitoring scenario is suggested and illustrated on a real-world data set.
Series: Research Report Series / Department of Statistics and Mathematics

Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第7876号
農博第1034号
新制||農||776(附属図書館)
学位論文||H11||N3239(農学部図書室)
UT51-99-G470
京都大学大学院農学研究科農芸化学専攻
(主査)教授 林 力丸, 教授 佐藤 文彦, 教授 江崎 信芳
学位規則第4条第1項該当

Sn-based solder alloys are extensively used in electronic devices to form interconnects between different components to provide mechanical support and electrical path. The formation of a reliable solder interconnects fundamentally relies on the metallurgic reaction between the molten solder and solid pad metallization in reflowing. The resultant IMC layer at the solder/pad metallization interface can grow continuously during service or aging at an elevated temperature, uplifting the proportion of IMCs in the entire solder joint. However, the essential mechanical properties of interfacial IMC (i.e. Cu6Sn5, Cu3Sn) layers, such as Young s modulus and hardness, are drastically different in comparison with Sn-based solder and substrate. Therefore, the increasing fraction of interfacial IMCs in the solder joint can lead to significant deformation incompatibility under exterior load, which becomes an important reliability concern in the uses of solder joints for electronic interconnects. In the past decades, extensive research works were implemented and reported regarding the growth of interfacial IMC layers and its effect on the mechanical integrity of solder joints. But, the following fundamental issues in terms of mechanical and microstructural evolution in the uses of solder joints still remain unclear, demanding further research to elaborate: (1) The protrusion of IMCs: Though the growth of interfacial IMC layers along the diffusion direction in solder joints were studied extensively, the growth of IMCs perpendicular to the diffusion direction were reported in only a few papers without any further detailed investigation. This phenomena can crucially govern the long-term reliability of solder interconnects, in particular, in the applications that require a robust microstructural integrity from a solder joint. (2) Fracture behaviour of interfacial IMC layers: The fracture behaviour of interfacial IMC layers is a vital factor in determining the failure mechanism of solder joints, but this was scarcely investigated due to numerous challenges to enable a potential in-situ micro-scale tests. It is therefore highly imperative to carry out such study in order to reveal the fracture behaviour of interfacial IMC layers which can eventually provide better understanding of the influence of interfacial IMC layers on the mechanical integrity of solder joints. (3) Volume shrinkage: The volume shrinkage (or solder joint collapse) induced by the growth of interfacial IMC layers was frequently ascribed as one of the main causes of the degradation of mechanical reliability during aging due to the potentially resulted voids and residual stress at the solder/substrate interface. However, very few experimental works on the characterisation of such type of volume shrinkage can be found in literatures, primarily due to the difficulties of observing the small dimensional changes that can be encountered in the course of IMCs growth. (4) Residual stress: The residual stress within solder joints is another key factor that contributes to the failure of solder joints under external loads. However, the stress evolution in solder joints as aging progresses and the potential correlation between the residual stress and the growth of interfacial IMC layers is yet to be fully understood, as stress/strain status can fundamentally alter the course of total failure of a solder joint. (5) Crack initiation and propagation in solder joints: Modelling on the mechanical behaviour of solder joints is often undertaken primarily on the stress distribution within solder joints, for instance, under a given external loading. But there is lack of utilising numerical analysis to simulate the crack initiation and propagation within solder joints, thus the effect of interfacial IMC layers on the fracture behaviour of the solder joints can be elaborated in further details. In this thesis, the growth of interfacial IMCs in parallel and perpendicular to the interdiffusion direction in the Sn99Cu1/Cu solder joints after aging was investigated and followed by observation with SEM, with an intention of correlating the growth of IMCs along these two directions with aging durations based on the measured thickness of IMC layer and height of perpendicular IMCs. The mechanism of the protrusion of IMCs and the mutual effect between the growth of IMCs along these two directions was also discussed. The tensile fracture behaviour of interfacial Cu6Sn5 and Cu3Sn layers at the Sn99Cu1/Cu interface was characterised by implementing cantilever bending tests on micro Cu6Sn5 and Cu3Sn pillars prepared by focused ion beam (FIB). The fracture stress and strain were evaluated by finite element modelling using Abaqus. The tensile fracture mechanism of both Cu6Sn5 and Cu3Sn can then be proposed and discussed based on the observed fracture surface of the micro IMC pillars. The volume shrinkage of solder joints induced by the growth of interfacial IMC layers in parallel to the interdiffusion direction in solder joint was also studied by specifically designed specimens, to enable the collapse of the solder joint to be estimated by surface profiling with Zygo Newview after increased durations of aging. Finite element modelling was also carried out to understand the residual stress potentially induced due to the volume shrinkage. The volume shrinkage in solder joints is likely to be subjected to the constraint from both the attached solder and substrate, which can lead to the build-up of residual stress at the solder/Cu interface. Depth-controlled nanoindentation tests were therefore carried out in the Sn99Cu1 solder, interfacial Cu6Sn5 layer, Cu3Sn layer and Cu with Vickers indenter after aging. The residual stress was then evaluated in the correlation with aging durations, different interlayers and the locations in the solder joint. Finally, finite element models incorporated with factors that may contribute to the failure of solder joints, including microstructure of solder joints, residual stress and the fracture of interfacial IMC, were built using Abaqus to reveal the effect of these factors on the fracture behaviour of solder joints under applied load. The effect of growth of IMC layer during aging on the fracture behaviour was then discussed to provide a better understanding of the degradation of mechanical integrity of solder joints due to aging. The results from this thesis can facilitate the understanding of the influence of interfacial IMC layers on the mechanical behaviour of solder joints due to long-term exposure to high temperatures.

Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xiii, 133 p.; also includes graphics (some col.) Includes bibliographical references (p. 124-133). Available online via OhioLINK's ETD Center

Thymidylate synthase (TS) catalyzes the conversion of dUMP into dTMP via a methyl transfer from the cofactor, 5,10-methylenetetrahydrofolate (CH2THF), which is converted to dihydrofolate (DHF) during the reaction. Because this reaction is a step in the only de novo pathway leading to thymidine nucleotides, there has been considerable interest in TS inhibition for the treatment of proliferative disease. This had led to a large body of biochemical and structural data and a proposed reaction mechanism. Despite this extensive study, there are a number of unanswered questions regarding TS function. The role of the large ligand-induced conformational change is poorly understood, and many steps in the proposed mechanism of catalysis are unconfirmed. The roles of many evolutionarily conserved residues are also poorly understood, notably those located away from the active site. In this work, 23 structures of E. coli TS are presented. These structures are of eight site-specific mutants bound to several ligand combinations. The results of this work cast doubt on a number of aspects of previously published models of the reaction mechanism, and lead to a new proposed model. TS appears to use strain, electrostatic interactions, and conformational change to influence the stability, and thus reactivity, of the catalytic enzyme-substrate covalent bond. This work adds to a growing body of data suggesting that the stability of this bond is variable. Instability of this bond is central to the new proposed reaction mechanism. The mechanism proposed here accounts for the reaction without requiring a large isomerization of the ligand complex that was previously thought to be necessary. Also presented is evidence that CH2THF binds to TS without opening of the 5-membered ring and in a conformation similar to that of other TS-bound folates but different from the conformation observed in solution. The roles played by many conserved residues appears to be subtle, as evidenced by the small structural changes of mutants when compared to wild-type. The conservation of these residues suggests that TS is a highly optimized enzyme under strong selective pressure to maintain maximum catalytic activity.

L'essor actuel des technologies soi est lie a la production d'un materiau de depart de qualite, dont le juge final est le comportement electrique des circuits integres. Cette these decrit des ameliorations et de nouvelles idees pour l'evaluation des proprietes electriques des materiaux soi. Les methodes presentees sont appliquees en priorite au nouveau materiau unibond. Nous donnons d'abord une vue d'ensemble des technologies soi et des methodes de caracterisation disponibles. Nous exposons ensuite notre contribution en commencant par la mesure electrique d'epaisseur du film de silicium dans un dispositif mos, pour laquelle nous proposons une extension d'une methode existante. La duree de vie des porteurs dans le film de silicium est ensuite etudiee par les techniques recentes des transitoires de courant de drain dans des transistors mos. Nous montrons la necessite d'une approche statistique pour comparer entre eux divers materiaux soi. Nous presentons ensuite des methodes de caracterisation rapide, ne necessitant pas la fabrication de dispositifs. L'oxyde enterre et le substrat silicium sous-jacent sont etudies par sonde a mercure, apres elimination du film de silicium par voie chimique. Pour la mesure du dopage residuel du film mince soi, nous evaluons les possibilites du pseudo-transistor mos. Nous proposons par ailleurs une nouvelle methode pour determiner tres rapidement et sans ambiguite le type, applicable aux tres faibles dopages. La derniere partie est consacree a l'oxyde de grille des technologies mos-soi. Une etude en time dependent dielectric breakdown sur dispositifs mos nous permet de montrer que le comportement en claquage intrinseque est identique sur soi et sur silicium massif. Pour s'affranchir du cout et de la longueur d'une telle etude, nous proposons une nouvelle methode simple de caracterisation d'oxyde de grille sur soi, ne necessitant pas d'autre etape technologique que la realisation de l'oxyde lui-meme.

xii, 107 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Non-muscle myosin II generates contractile forces for processes such as cytokinesis, motility, and polarity. Contractility requires assembly of myosin molecules into bipolar mini-filaments through electrostatic interactions between coiled-coil tail domains of the heavy chains. Analyses of myosin II from various organisms have revealed "assembly domains" within the C-terminal portion of the tail domain that mediate filament formation. However, it has been unclear precisely how assembly domains interact with one another, or otherwise contribute to tail-tail interactions, to form the bipolar mini-filament structure. To understand tail domain interactions, we first identified a 90-residue region (1849-1940) of the Drosophila non-muscle myosin II tail domain that was necessary and sufficient for filament formation, using salt-dependent solubility and a novel fluorescence energy transfer assay. We identified residues within this "assembly domain" that were critical for filament assembly by analyzing the effect of point mutations. We found that single point mutations in specific positively charged regions completely disrupt filament assembly. Surprisingly, none of the negatively charged regions within the assembly domain are required for assembly. Most of the mutations in positively charged residues that disrupted filament assembly clustered within a 15-residue segment (1880-1894) that appears to form a critical interaction surface. Using this information, along with known geometrical constraints and electrostatic calculations, we constructed a structural model of the bipolar mini-filament. This model features one favored anti-parallel tail overlap and multiple slightly less stable alternative overlaps. The ability of the positive segment to interact with multiple negative regions explains the lack of required negatively charged residues in the assembly domain. To our knowledge, this structural model of the non- muscle myosin II bipolar filament is consistent with all physical observations and provides a framework for understanding the detailed mechanism by which this fundamental cellular structure is generated. This dissertation contains previously published and unpublished co-authored material.
Committee in charge: Tom Stevens, Chairperson, Chemistry; Kenneth Prehoda, Advisor, Chemistry; J. Andrew Berglund, Member, Chemistry; Christopher Doe, Member, Biology; Karen Guillemin, Outside Member, Biology

Based on a meta-study, the paper describes the existing options, areal extents, and Swedish farmers' conditions for energy crop production promoted by the governments to mitigate and adapt to climate change. The drivers of and barriers to cultivating various energy crops are described in terms of a variety of motivational factors. The approach used peer-reviewed and gray literature using three Internet sources. Questions addressed include the energy crops available to Swedish farmers and how well established they are in terms of areal extent. What drivers of and barriers to growing energy crops do farmers perceive? How do various motivational factors for these drivers and barriers correspond to the adoption of certain energy crops? The results indicate that 13 energy-related crops are available, of which straw (a residue), oil crops, and wheat are the most extensively produced in terms of cultivated area. Results confirm earlier research findings that converting from annual to perennial crops and from traditional crops or production systems to new ones are important barriers. Economic motivations for changing production systems are strong, but factors such as values (e.g., esthetic), knowledge (e.g., habits and knowledge of production methods), and legal conditions (e.g., cultivation licenses) are crucial for the change to energy crops. Finally, there are knowledge gaps in the literature as to why farmers decide to keep or change a production system. Since the Swedish government and the EU intend to encourage farmers to expand their energy crop production, this knowledge of such motivational factors should be enhanced.
Ett konkurrenskraftigt jordbruk – kommunikation kring klimatförändring och nya möjligheter (K3), Stiftelsen Lantbruksforskning

Cette thèse étudie l’effet des variations du taux de change sur la valeur de l’entreprise, les déterminants de la politique de couverture et le rôle des conflits d’agence. Les résultats montrent que la non-significativité de l’exposition au risque de change est expliquée par une asymétrie de la couverture. Le niveau de couverture de change dépend des économies d’échelle, du risque de détresse financière et du niveau d’exportations de l’entreprise. Nos résultats révèlent, aussi, que la rémunération des dirigeants en actions et en options réduit le risque de change résidu de la couverture
This PhD thesis examines exchange rate movements’ effect on firm value, determinants of hedging policy and the role of agency conflicts. Results show that non-significance of foreign exchange rate exposure is explained by an asymmetric hedging. Firm hedging level depends from scale of economies, financial distress risk and it exports level. Our empirical results demonstrate, also, that CEO shares and stock-options compensations have negative effect on foreign exchange risk that is residue from hedging

Human society releases greenhouse gas emissions to the atmosphere while providing housing, heat, mobility and industrial production. Man-made greenhouse gas emissions are the main causes of climate change, coming mainly from burning fossil fuels and land-use changes. Sustainably managed forests play an important role in climate change mitigation with the prospect of sustainably providing essential materials and services as part of a low-carbon economy, both through the substitution of fossil-intensive fuels and material and through their potential to capture and store carbon in the long-term perspective. The overall aim of this thesis was to develop a methodology under a life cycle perspective to assess the climate impact of the sustainable use of forest biomass in bioenergy and material systems. To perform this kind of analysis a methodological framework is needed to accurately compare the different biological and technological systems with the aim to minimize the net carbon dioxide emissions to the atmosphere and hence the climate impact. In such a comparison, the complete energy supply chains from natural resources to energy end-use services has to be considered and are defined as the system boundaries. The results show that increasing biomass production through more intensive forest management or the usage of more productive tree species combined with substitution of non-wood products and fuels can significantly reduce global warming. The biggest single factor causing radiative forcing reduction was using timber to produce wood material to replace energy-intensive construction materials such as concrete and steel. Another very significant factor was replacing fossil fuels with forest residues from forest thinning, harvest, wood processing, and post-use wood products. The fossil fuel that was replaced by forest biomass affected the reductions in greenhouse gas emissions, with carbon-intensive coal being most beneficial to replace. Over the long term, an active and sustainable management of forests, including their use as a source for wood products and bioenergy allows the greatest potential for reducing greenhouse gas emissions.

Cette thèse porte sur l'étude de la diffusion des asphaltènes dans les catalyseurs d'hydrotraitement. La revue bibliographique met en évidence d'importantes lacunes dans les connaissances, d'une part sur l'impact sur les processus de diffusion des fortes températures rencontrées dans les procédés de raffinage et d'autre part, sur la dynamique des asphaltènes dans les réseaux poreux des catalyseurs. Ainsi, une double approche expérimentale a été développée, s'articulant dans un premier temps autour d'une étude de diffusion et d'adsorption dans des conditions proches de celles des procédés, puis dans un second temps une étude de la diffusion en milieu confiné par Résonance Magnétique Nucléaire (RMN) à travers des techniques de mesure de temps de relaxation ainsi que la RMN à gradient de champ pulsé (DOSY). Les résultats obtenus montrent que même à haute température, la diffusion des asphaltènes dans les catalyseurs est un processus très lent, plusieurs jours étant nécessaires pour que le coeur soit atteint. Les techniques de RMN utilisées montrent le caractère fortement confiné des asphaltènes dans le milieu poreux ainsi que de fortes interactions entre les asphaltènes et la surface alumine des catalyseurs, à l'origine d'une très faible dynamique bien que le processus d'adsorption soit dans une certaine mesure quand même réversible
This PhD thesis deals with the diffusion of asphaltenes in hydrotreatment catalysts. The literature review shows weaknesses in knowledge about both, how does the high temperature impact the diffusion phenomena and, what is the dynamic of asphaltenes in the porous media. Therefore, a double experimental approach has been developed, first the diffusion and the adsorption of asphaltenes near process conditions have been studied, and then the dynamic in porous media has been studied by Nuclear Magnetic Resonance (NMR) technics which involves relaxation times measurements and Diffusion Ordered SpectroscopY (DOSY). Results show that even at high temperature, the diffusion of asphaltenes in catalysts is relatively slow; several days are needed to reach the center. The NMR results highlight a slow dynamic of asphaltenes in the porous media, since they are in confined environment and they are in strong interactions with alumina, even if the adsorption is to a certain extent reversible

Crop management practices, such as soil tillage and crop residue management, are land management activities with potentially large impacts on carbon (C) cycling and climate at the global scale. Improvements in crop management practices, such as conservation tillage or 'no-till' (NT), have been proposed as climate change mitigation measures because such practices may alter C cycles through increased sequestration of soil C in agricultural soils. Despite their potential importance, regional to global scale data are lacking for many crop management practices, and few studies have evaluated the potential impact of the full range of crop management practices on C cycling and climate at the global scale. However, monitoring of crop management practices is crucial for assessing spatial variations in management intensity and informing policy decisions. Inclusion of crop management practices in Earth system models used for assessing global climate is a key requirement for evaluating the overall effects of different crop management practices on C cycling and their potential to mitigate climate change. Studies in this dissertation seek to address these issues by: (1) evaluating the efficacy of remote sensing methods for monitoring differences in soil tillage and crop residue management practices in Iowa; (2) incorporating soil tillage practices into an Earth system model and assessing the potential for soil C sequestration and climate change mitigation through adoption of NT practices; (3) assessing the historical impact of including the full range of crop management practices (residue harvest, grain harvest, soil tillage, irrigation, and fertilization) on changes in C cycling associated with land use and land cover change (LULCC) to crops in an Earth system model. The remote sensing study found that performance of the minimum Normalized Difference Tillage Index (minNDTI) method for assessing differences in tillage and residue management was below average compared to previous studies, even when using imagery from both Landsat 8 and Sentinel-2A sensors. Accurate assessment of these practices using minNDTI was hindered by issues with image quality and inability to obtain sufficient cloud-free, time series imagery during the critical planting window. Remote sensing research aimed at obtaining regional to global scale data on tillage and residue management practices is likely to continue to face these issues in the future, but further research should incorporate additional sensors and assess the efficacy of the minNDTI method for multiple locations and years. Adoption of NT practices in the Community Land Model, which is the land component of the Community Earth System Model, resulted in a cumulative soil C sequestration of 6.6 – 14.4 Pg C from 2015 – 2100 under a future climate change scenario (Representative Concentration Pathway 8.5), and cumulative soil C sequestration was equal to approximately one year of present-day fossil fuel emissions. Adjusting for areas where NT is already practiced had minor impacts on cumulative soil C storage, reducing gains in soil C from NT adoption by 0.4 – 0.9 Pg C globally. These results indicate that soil C sequestration and potential for climate change mitigation through NT may be more limited than has been anticipated elsewhere. Soil C sequestration via NT adoption was highest in temperate regions of developed countries with high initial soil C contents, indicating these areas should be targeted for NT adoption. Simulating the full range of crop management practices in the Community Land Model resulted in an increase in C emissions due to LULCC of 29 – 38 Pg C compared to scenarios with generic crops and model defaults. Individual crop management practices with the largest impact on LULCC emissions were crop residue harvest (18 Pg C), followed by grain harvest (9 Pg C) and soil tillage (5 Pg C). Although implementation of crop residue harvest and soil tillage was extreme in this study, these results imply that Earth system models may underestimate emissions from LULCC by excluding the full range of crop management practices. Studies in this dissertation corroborate the importance of crop management practices for C cycling and climate, but further research on these management practices is needed in terms of data collection, improving process-level understanding, and inclusion of these practices in Earth system models.
Doctor of Philosophy

Une nouvelle méthodologie de modélisation cinétique des procédés de raffinage traitant les charges lourdes a été développée. Elle modélise, au niveau moléculaire, la composition de la charge et les réactions mises en œuvre dans le procédé.La composition de la charge est modélisée à travers un mélange de molécules dont les propriétés sont proches de celles de la charge. Le mélange de molécules est généré par une méthode de reconstruction moléculaire en deux étapes. Dans la première étape, les molécules sont créées par assemblage de blocs structuraux de manière stochastique. Dans la deuxième étape, les fractions molaires sont ajustées en maximisant un critère d'entropie d'information.Le procédé de raffinage est ensuite simulé en appliquant, réaction par réaction, ses principales transformations sur le mélange de molécules, à l'aide d'un algorithme de Monte Carlo.Cette méthodologie est appliquée à deux cas particuliers : l'hydrotraitement de gazoles et l'hydroconversion de résidus sous vide (RSV). Pour le premier cas, les propriétés globales de l'effluent sont bien prédites, ainsi que certaines propriétés moléculaires qui ne sont pas accessibles dans les modèles traditionnels. Pour l'hydroconversion de RSV, dont la structure moléculaire est nettement plus complexe, la conversion des coupes lourdes est correctement reproduite. Par contre, la prédiction des rendements en coupes légères et de la performance en désulfuration est moins précise. Pour les améliorer, il faut d'une part inclure de nouvelles réactions d'ouverture de cycle et d'autre part mieux représenter la charge en tenant compte des informations moléculaires issues des analyses des coupes de l'effluent.

Aviation greenhouse gas (GHG) emissions have risen faster than any other transport sector to double between 1990 and 2005. Such emissions from aviation could increase another 700 percent globally, and at least 150 percent in the European Union (EU), by 2050 due to continuously increasing consumer demand. To reverse the trend of rising emissions writ large, the EU has set 2030 climate goals of reducing its GHG emissions by 40 percent (relative to 2005) and having 32 percent of gross final energy consumption from renewables. The EU’s recast Renewable Energy Directive (RED-II) calls for 14 percent of transport energy from renewables, gives multipliers to advanced biofuels, and restricts biomass that is from ecologically valuable lands or that causes land use change. Energy security and energy independence are also long-term EU goals. Many of these goals and targets have also been adopted by the European Free Trade Area (EFTA). Despite these efforts, options are limited to reduce aviation emissions compared to other transport sectors, leaving aviation biofuels, also known as renewable jet fuels (RJFs), as currently the only commercialized option. Against this backdrop, in this thesis scenario analyses were conducted to produce biomass from EU+EFTA lands, project RJF yields from this biomass, and estimate emissions savings of these RJFs compared to petroleum jet fuel. Particular effort was devoted to identifying biomass, biofuels, and EU+EFTA lands that comply with RED-II criteria. The two RJF pathways selected were hydroprocessed esters and fatty acid (HEFA) conversion of Camelina sativa vegetable oil and Fischer-Tropsch (FT) synthesis of forestry residue lignocellulosic biomass. Over 117 million hectares in the EU+EFTA was identified as available for Camelina sativa cultivation, which could yield over 64 Mt of RJF each year, or 113 percent of the total jet fuel consumed in the EU+EFTA in 2017. Conversely, if 50 percent of the forestry residues generated as by-products from EU+EFTA roundwood harvesting operations in 2017 were extracted from harvest sites, 40 Mt of forestry residues would be available as biomass, which would yield almost 7.6 Mt of RJF annually (13% of 2017 jet fuel consumption). If all 144 million hectares of EU+EFTA forest lands deemed available for wood supply were logged, 1,772 Mt of forestry residues would be produced in total (at 50 percent extraction), which could result in almost 337 Mt of RJF, or 590% of the jet fuel consumed in the region in 2017. Hence, RJF can be feasibly produced from biomass from EU+EFTA lands, in amounts that meet or exceed the annual jet fuel consumption of the EU+EFTA, and in ways that meet or exceed RED-II sustainability criteria. However, the proportion of these RJF yields to total annual EU+EFTA jet fuel consumption will decrease over time as the number of flights and their resulting emissions increase. The two RJFs also emit 67 percent and 91 percent fewer GHG emissions, respectively, than petroleum-based jet fuel, showing them to be important tools for the EU to meet its 2030 renewables and emissions reductions targets. Producing the biomass feedstocks and RJFs in these quantities will require the EU to make serious decisions on land use trade-offs, such as whether livestock production is more important than biofuel production.

Le Disjoncteur Différentiel Résiduel (DDR) doit garantir la continuité de service ce qui signifie qu'aucun défaut autre que ceux pouvant mettre l'utilisateur en danger ne doivent faire déclencher le produit pour éviter soit des désagréments (non alimentation du congélateur) soit une perte financière (non exploitation d'une installation photovoltaïque).La fonction mesure est composée de :- Un tore pour la mesure du courant résiduel, il réalise naturellement la somme des courants entrant et sortant de l'installation- Une plaquette de mise en forme (filtrage)- Un actionneur, le relais polarisé qui fixe le seuil du dispositif (par sa puissance de déclenchement et fournit une énergie mécanique pour mettre l'installation hors tension.Ces déclenchements non désirés proviennent des défauts de la chaine de mesure. Nous pouvons en citer 3 principales causes :- Courant de fuite à la terre trop important (perturbation réseau mode commun)- Champs magnétiques rayonnés (courant passant dans le primaire du tore)- Equilibrage du tore (mode différentiel) (courant passant dans le primaire du tore)Les surtensions atmosphériques étant considérées comme étant les perturbations les plus critiques, les travaux faits durant cette thèse reposent sur ce phénomène. Toute la problématique est basée sur la manière avec laquelle le disjoncteur différentiel répond face à ces perturbations. Une bonne compréhension de sa réaction dans de tels cas s'avère nécessaire. Les objectifs visés par cette étude sont de :- Trouver un modèle temporel du phénomène de foudre- Mettre en évidence les différentes phases de fonctionnement engendré lors de la réponse d'un DDR à un coup de foudre- Etablir un modèle comportemental du DDR adapté à chaque phase- Mettre en évidence la cause des déclenchements intempestifs- Proposer des solutions permettant a nos produits de ne pas déclencher de façon intempestives et fiabiliser ainsi leur fonctionnement- Diminuer par conséquent les retours clients
The Residual Current Device (RCD) must ensure the continuity of service which means that no default other than those that can put the user at risk should make the product trigger, to avoid any inconvenience (freezer not supplied) or a financial loss (non-operation of a photovoltaic). The measurement function is made up of:- A torus for measuring the residual current, it naturally carries the sum of currents entering and exiting the installation- A plate shaping (filtering)- An actuator, the polarized relay which sets the threshold of the device (through its power of initiation) and provides mechanical energy to turn off power supply.These false triggering are caused by defaults initiated among the measurement chain. We can cite three main reasons:- Residual current too high (over-voltages on electrical network by common mode)- Radiated Magnetic Fields (current through the primary circuit of the torus)- Balancing the torus (differential mode) (current through the primary circuit of the torus)As the atmospheric over-voltages are considered to be the most critical disturbances, they will appear as the principal subject of this thesis. The main issue is the behavior of the RCD facing a lightning stroke. So, a well understanding of the manner that it will respond in such situations is necessary. The objectives of this study are to:- Establish a temporal model of lightning stroke- Highlight the different working phases in front of a lightning stroke- Establish a RCD's behavioral model adapted to every phase- Highlight the causes of unwanted triggers- Propose solutions enabling our products to not trigger by default and so improve the reliability of their functioning- Reduce customer returns

Single-species plantation forests have become the dominant source of inputs for the Queensland forest industry. Almost a quarter (50,000 ha) of the Queensland plantation estate is accounted for by plantations of the nitrogen (N) demanding species, hoop pine (Araucaria cunninghamii). The majority of the hoop pine estate was originally native forest, and is currently moving into the second rotation phase. The future of plantations of this N demanding species is dependent on the long-term maintenance of soil N cycling and availability. Land-use change can impact soil N dynamics; however there is currently limited knowledge of how the land-use change from native forest (NF) to first rotation (1R) hoop pine plantation and subsequent second rotation (2R) hoop pine plantation, and the associated disturbance due to site preparation have influenced soil N transformations and availability. The objectives of this study were to examine the impact of land-use change from 1) NF to 1R hoop pine plantation, and 2) 1R hoop pine plantation to 2R hoop pine plantation on soil N dynamics. The impact of the current 2R residue management strategy was also examined. The study was conducted in adjacent NF, 1R hoop pine plantation, and 2R hoop pine plantation (5-year old) in Yarraman State Forest, south-east Queensland. A laboratory incubation using the 15N isotope dilution method was undertaken in order to examine the impact of land-use change and residue management on gross N transformations. Results showed that land-use change had a significant impact on soil N transformations. The conversion of the NF to the 1R hoop pine plantation significantly reduced the availability of NH4+-N and NO3- -N. It also decreased the rate of gross N mineralisation (measured under anaerobic conditions) and gross nitrification (measured under aerobic conditions). This result was related to lower soil, litter and root C:N ratios in the NF compared to the 1R hoop pine plantation, indicating a reduction in organic matter quality associated with the land-use change. The conversion of 1R to 2R hoop pine plantation resulted in an increase in the gross rate of ammonification. This was attributed to an increase in mineralisation of native organic N associated with changes in soil physical conditions and microclimate as a result of harvesting. Residue management was found to have no significant influence on the soil N transformations in the 2R plantation approximately five years after establishment. A second study focused on quantifying the impact of land use and residue management on soil soluble organic N (SON) pools using a variety of extraction methods, including water, hot water, 0.5 M K2SO4, 2 M KCl and hot KCl. Both land use and residue management were found to have a significant influence on the size of soil SON pools. The conversion of NF to 1R hoop pine plantation tended to result in a decrease in the amount of soil SON and the potential to produce SON. This reduction coincided with increased soil, litter and root C:N ratios, and may therefore be the result of a decline in organic matter quality and quantity. The conversion of 1R to 2R hoop pine plantation generally resulted in a reduction in the amount of SON. Residue management also had a significant influence on soil SON pools, which tended to be higher in windrows of harvest residues than in tree rows. The impact of land-use change on the size, activity, and composition of the soil microbial community was examined using fumigation-extraction, CO2 respiration, and community level physiological profiling (CLPP) techniques. Landuse change from NF to 1R hoop pine plantation resulted in a reduction in microbial biomass and activity, and a shift in soil microbial community composition. While the conversion from 1R to 2R hoop pine plantation appeared to have no significant influence on the size and activity of the soil microbial community, there were some indications of a difference in community composition. Soil microbial biomass and activity tended to increase as the quality and quantity of organic matter input increased. An 18-month field-based study was conducted using the in-situ incubation method to examine the impact of land-use change on seasonal N dynamics. The results of this study were consistent with results from the laboratory studies. In general, the rate of N transformations and size of soil mineral N pools and microbial biomass were lower in the 1R soil compared to the NF soil. The 1R soils tended to have lower total C and total N, and higher C:N ratios compared to the NF soil, indicating that lower rates of N transformation and N availability in the 1R soil may be a result of significant reductions in organic matter quality and quantity. While the difference in the rates of net N mineralisation and net nitrification among the plantation soils were statistically insignificant, over the 18-month sampling period more N was mineralised and nitrified in the 2R soil compared to the 1R soil. Residue management also influenced the total amount of N transformed over the sampling period, with more N tending to be mineralised and nitrified in soil under windrowed residues compared to soil under tree rows. Seasonal fluctuations in soil N dynamics tended to be controlled by temperature and soil moisture. From these results, it was concluded that land-use change and residue management had a significant impact on soil N dynamics. This was possibly associated with shifts in the quality and quantity of organic inputs, soil microbial properties and microclimate conditions. Results from this study indicate that land-use change and residue management may have implications for the long-term productivity of the soil resource. Future studies are required to improve the understanding of the chemical and biological mechanisms driving changes in soil N dynamics.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Faculty of Science, Environment, Engineering and Technology
Full Text

In South Africa, being the second largest global coal exporter, coal mining plays a pivotal role in the growth of our economy, as well as supplying our nation’s ever increasing electricity needs; while also accounting for more than 10% of the 20 x 109 m3 water used annually in the country. Coal mining may thus be classified as a large-scale water user; known to inevitably generate wastewater [acid mine drainage (AMD)] and other waste material, including fly ash (FA). Current and conventional AMD treatment technologies include precipitation–aggregation (coagulation/flocculation) – settling as hydroxides or insoluble salts. The process stream resulting from these precipitation processes is still highly saline, therefore has to undergo secondary treatment. The best available desalination techniques include reverse osmosis (RO), electro dialysis (ED), ion exchange and evaporation. All available treatment methods associated with raw AMD and its derived process stream fall prey to numerous drawbacks. The result is that treatment is just as costly as the actual coal extraction. In addition, remediation only slows the problem down, while also having a short lifespan. Research conducted into converting fly ash, an otherwise waste material, into a marketable commodity has shown that direct mixing of known ratios of FA with AMD to a pre-determined pH, erves a dual purpose: the two wastes (AMD and FA) could be neutralized and produced a much cleaner water (secondary co-disposal [FA/AMD]-process water), broadly comparable to the process water derived from precipitation-aggregation treated AMD. The collected post process solid residues on the other hand, could be used for production of high capacity ion exchange material (e.g. zeolite A, faujasite, zeolite P, etc.). The produced ion exchange material can subsequently be utilized for the attenuation of metal species in neutralized FA/AMDprocess waters.
Magister Scientiae - MSc

En usinage, la zone de coupe présente des conditions de température, des cinétiques thermiques, des déformations et des pressions extrêmes. Dans ce contexte, être capable de relier les variations des conditions de coupe (vitesse de coupe, avance, lubrification, usure, outil,...) à l'intégrité de la surface usinée constitue un objectif scientifique majeur. Cette thèse s'intéresse au cas du tournage finition du 15-5PH (acier inoxydable martensitique utilisé, entre autre, pour la fabrication des pièces de rotor d'hélicoptère ainsi que les pompes et les vannes de circuit primaire de centrale nucléaire) et s'inscrit dans le cadre du projet MIFSU (Modélisation de l'Intégrité et de la Fatigue des Surfaces Usinées).Dans un premier temps, le comportement du matériau a été étudié afin d'alimenter les simulations d'usinage. Des essais de dilatométrie libre ont été conduit afin de calibrer les cinétiques d'austénitisation du 15-5PH pour des vitesses de chauffe élevées (jusqu'à 11000 °C/s). Les paramètres du modèle de changement de phase de Leblond ont alors été identifiés. De plus, des essais de compression dynamique (dε/dt allant de 0.01 à 80 /s et ε > 1) ont été réalisés pour calibrer une loi de comportement élasto-plastique aux grandes déformations avec une sensibilité à la vitesse de déformation. Ces essais ont aussi permis de mettre en évidence des phénomènes de recristallisation dynamique et leurs influences sur la contrainte d'écoulement du matériau. Un modèle de recristallisation dynamique a donc également été mis en œuvre.En parallèle, un modèle numérique de prédiction de l'intégrité des surfaces tournées a été construit. Ce modèle repose sur une méthodologie dite " hybride " (développée au cours de la thèse Frédéric Valiorgue pour l'acier AISI 304L) qui consiste à supprimer la modélisation de l'outil de coupe et de la formation du copeau, et à remplacer l'impact thermomécanique de ces derniers sur la surface usinée par des chargements équivalents. Une étape de calibration de ces chargements a donc été réalisée à travers des essais de coupe orthogonale et de frottement (étude de sensibilité des efforts d'usinage, du coefficient de frottement et du coefficient de partage thermique) aux variations des paramètres de coupe.Enfin, les résultats des simulations numériques de tournage portant sur la prédiction des changements de microstructure (austénitisation et recristallisation dynamique) ainsi que des contraintes résiduelles ont été comparés aux résultats issus d'une campagne d'essais de chariotage.

Doutoramento em Bioquímica
Os polissacarídeos são os componentes maioritários dos grãos de café verde e torrado e da bebida de café. Os mais abundantes são as galactomananas, seguindo-se as arabinogalactanas. Durante o processo de torra, as galactomananas e arabinogalactanas sofrem modificações estruturais, as quais estão longe de estar completamente elucidadas devido à sua diversidade e à complexidade estrutural dos compostos formados. Durante o processo de torra, as galactomananas e arabinogalactanas reagem com proteínas, ácidos clorogénicos e sacarose, originando compostos castanhos de alto peso molecular contendo nitrogénio, designados de melanoidinas. As melanoidinas do café apresentam diversas atividades biológicas e efeitos benéficos para a saúde. No entanto, a sua estrutura exata e os mecanismos envolvidos na sua formação permanecem desconhecidos, bem como a relação estrutura-atividade biológica. A utilização de sistemas modelo e a análise por espectrometria de massa permitem obter uma visão global e, simultaneamente, detalhada das modificações estruturais nos polissacarídeos do café promovidas pela torra, contribuindo para a elucidação das estruturas e mecanismos de formação das melanoidinas. Com base nesta tese, oligossacarídeos estruturalmente relacionados com a cadeia principal das galactomananas, (β1→4)-Dmanotriose (Man3), e as cadeias laterais das arabinogalactanas, (α1→5)-Larabinotriose (Ara3), isoladamente ou em misturas com ácido 5-Ocafeoilquínico (5-CQA), o ácido clorogénico mais abundante nos grãos de café verde, e péptidos compostos por tirosina e leucina, usados como modelos das proteínas, foram sujeitos a tratamento térmico a seco, mimetizando o processo de torra. A oxidação induzida por radicais hidroxilo (HO•) foi também estudada, uma vez que estes radicais parecem estar envolvidos na modificação dos polissacarídeos durante a torra. A identificação das modificações estruturais induzidas por tratamento térmico e oxidativo dos compostos modelo foi feita por estratégias analíticas baseadas principalmente em espectrometria de massa, mas também em cromatografia líquida. A cromatografia de gás foi usada na análise de açúcares neutros e ligações glicosídicas. Para validar as conclusões obtidas com os compostos modelo, foram também analisadas amostras de polissacarídeos do café obtidas a partir de resíduo de café e café instantâneo. Os resultados obtidos a partir dos oligossacarídeos modelo quando submetidos a tratamento térmico (seco), assim como à oxidação induzida por HO• (em solução), indicam a ocorrência de despolimerização, o que está de acordo com estudos anteriores que reportam a despolimerização das galactomananas e arabinogalactanas do café durante a torra. Foram ainda identificados outros compostos resultantes da quebra do anel de açúcares formados durante o tratamento térmico e oxidativo da Ara3. Por outro lado, o tratamento térmico a seco dos oligossacarídeos modelo (individualmente ou quando misturados) promoveu a formação de oligossacarídeos com um maior grau de polimerização, e também polissacarídeos com novos tipos de ligações glicosídicas, evidenciando a ocorrência de polimerização através reações de transglicosilação não enzimática induzidas por tratamento térmico a seco. As reações de transglicosilação induzidas por tratamento térmico a seco podem ocorrer entre resíduos de açúcares provenientes da mesma origem, mas também de origens diferentes com formação de estruturas híbridas, contendo arabinose e manose como observado nos casos dos compostos modelo usados. Os resultados obtidos a partir de amostras do resíduo de café e de café instantâneo sugerem a presença de polissacarídeos híbridos nestas amostras de café processado, corroborando a ocorrência de transglicosilação durante o processo de torra. Além disso, o estudo de misturas contendo diferentes proporções de cada oligossacarídeo modelo, mimetizando regiões do grão de café com composição distinta em polissacarídeos, sujeitos a diferentes períodos de tratamento térmico, permitiu inferir que diferentes estruturas híbridas e não híbridas podem ser formadas a partir das arabinogalactanas e galactomananas, dependendo da sua distribuição nas paredes celulares do grão e das condições de torra. Estes resultados podem explicar a heterogeneidade de estruturas de melanoidinas formadas durante a torra do café. Os resultados obtidos a partir de misturas modelo contendo um oligossacarídeo (Ara3 ou Man3) e 5-CQA sujeitas a tratamento térmico a seco, assim como de amostras provenientes do resíduo de café, mostraram a formação de compostos híbridos compostos por moléculas de CQA ligadas covalentemente a um número variável de resíduos de açúcar. Além disso, os resultados obtidos a partir da mistura contendo Man3 e 5-CQA mostraram que o CQA atua como catalisador das reações de transglicosilação. Por outro lado, nas misturas modelo contendo um péptido, mesmo contendo também 5-CQA e sujeitas ao mesmo tratamento, observou-se uma diminuição na extensão das reações transglicosilação. Este resultado pode explicar a baixa extensão das reações de transglicosilação não enzimáticas durante a torra nas regiões do grão de café mais ricas em proteínas, apesar dos polissacarídeos serem os componentes maioritários dos grãos de café. A diminuição das reações de transglicosilação na presença de péptidos/proteínas pode dever-se ao facto de os resíduos de açúcares redutores reagirem preferencialmente com os grupos amina de péptidos/proteínas por reação de Maillard, diminuindo o número de resíduos de açúcares redutores disponíveis para as reações de transglicosilação. Além dos compostos já descritos, uma diversidade de outros compostos foram formados a partir dos sistemas modelo, nomeadamente derivados de desidratação formados durante o tratamento térmico a seco. Em conclusão, a tipificação das modificações estruturais promovidas pela torra nos polissacarídeos do café abre o caminho para a compreensão dos mecanismos de formação das melanoidinas e da relação estrutura-atividade destes compostos.
Polysaccharides are the major components of green and roasted coffee beans, and coffee brew. The most abundant ones are galactomannans, followed by arabinogalactans. During the roasting process, galactomannans and arabinogalactans undergo structural modifications that are far to be completely elucidated due to their diversity and complexity of the compounds formed. During the roasting process, galactomannans and arabinogalactans react with proteins, chlorogenic acids, and sucrose, originating high molecular weight brown compounds containing nitrogen, known as melanoidins. Several biological activities and beneficial health effects have been attributed to coffee melanoidins. However, their exact structures and the mechanisms involved in their formation remain unknown, as well as the structure-biological activity relationship. The use of model systems and mass spectrometry analysis allow to obtain an overall view and, simultaneously, detailed, of the structural modifications in coffee polysaccharides promoted by roasting, contributing to the elucidation of the structures and formation mechanisms of melanoidins. Based on this thesis, oligosaccharides structurally related to the backbone of galactomannans, (β1→4)-D-mannotriose, and the side chains of arabinogalactans, (α1→5)-Larabinotriose, alone or in mixtures with 5-O-caffeoylquinic acid, the most abundant chlorogenic acid in green coffee beans, and dipeptides composed by tyrosine and leucine, used as models of proteins, were submitted to dry thermal treatments, mimicking the coffee roasting process. The oxidation induced by hydroxyl radicals (HO•) was also studied, since these radicals seem to be involved in the modification of the polysaccharides during roasting. The identification of the structural modifications induced by thermal and oxidative treatment of the model compounds was performed mostly by mass spectrometry-based analytical strategies, but also using liquid chromatography. Gas chromatography was used in the analysis of neutral sugars and glycosidic linkages. To validate the conclusions achieved with the model compounds, coffee polysaccharide samples obtained from spent coffee grounds and instant coffee were also analysed. The results obtained from the model oligosaccharides when submitted to thermal treatment (dry) or oxidation induced by HO• (in solution) indicate the occurrence of depolymerization, which is in line with previous studies reporting the depolymerization of coffee galactomannans and arabinogalactans during roasting. Compounds resulting from sugar ring cleavage were also formed during thermal treatment and oxidative treatment of Ara3. On the other hand, the dry thermal treatment of the model oligosaccharides (alone or when mixed) promoted the formation of oligosaccharides with a higher degree of polymerization, and also polysaccharides with new type of glycosidic linkages, evidencing the occurrence of polymerization via non-enzymatic transglycosylation reactions induced by dry thermal treatment. The transglycosylation reactions induced by dry thermal treatment can occur between sugar residues from the same origin, but also of different origins, with formation of hybrid structures, containing arabinose and mannose in the case of the model compounds used. The results obtained from spent coffee grounds and instant coffee samples suggest the presence of hybrid polysaccharides in these processed coffee samples, corroborating the occurrence of transglycosylation during the roasting process. Furthermore, the study of mixtures containing different proportions of each model oligosaccharide, mimicking coffee bean regions with distinct polysaccharide composition, subjected to different periods of thermal treatment, allowed to infer that different hybrid and non-hybrid structures may be formed from arabinogalactans and galactomannans, depending on their distribution in the bean cell walls and on roasting conditions. These results may explain the heterogeneity of melanoidins structures formed during coffee roasting. The results obtained from model mixtures containing an oligosaccharide (Ara3 or Man3) and 5-CQA and subjected to dry thermal treatment, as well as samples derived from spent coffee grounds, showed the formation of hybrid compounds composed by CQA molecules covalently linked to a variable number of sugar residues. Moreover, the results obtained from the mixture containing Man3 and 5-CQA showed that CQA acts as catalyst of transglycosylation reactions. On the other hand, in the model mixtures containing a peptide, even if containing 5-CQA and subjected to the same treatment, it was observed a decrease in the extent of transglycosylation reactions. This outcome can explain the low extent of non-enzymatic transglycosylation reactions during roasting in coffee bean regions enriched in proteins, although polysaccharides are the major components of the coffee beans. The decrease of transglycosylation reactions in the presence of peptides/proteins can be related with the preferential reactivity of reducing residues with the amino groups of peptides/proteins by Maillard reaction, decreasing the number of reducing residues available to be directly involved in the transglycosylation reactions. In addition to the compounds already described, a diversity of other compounds were formed from model systems, namely dehydrated derivatives formed during dry thermal treatment. In conclusion, the identification of the structural modifications in coffee polysaccharides promoted by roasting pave the way to the understanding of the mechanisms of formation of melanoidins and structure-activity relationship of these compounds.

碩士
國立勤益科技大學
資訊與電能科技研究所
95
The main purpose of this thesis is to study the charge equalization and capacity estimation of the lead-acid batteries. First, a three-level neutral point clamped AC/DC converter is adopted to charge the series batteries for obtain the charge equalization. The proposed charge equalization circuits can not only regulate the input power factor, but also make the voltage balance between the series batteries. Some simulation results are made to verify the effectiveness of proposed charger. As to the battery capacity estimation, the coulometric measurement method with Programmable system-on-chip (PSoC) are used to develop a lead-acid battery discharger. The discharger is not only used for battery discharge, but also can control discharging current via PSoC during discharging time and then calculates the residual capacity of the batteries. Finally, an intelligent capacity estimation method based on Extension theory and Extension neural network is developed for a lead-acid battery. Both of the two developed algorithms are with less learning time and high recognition. Some simulation results have been made to demonstrate the effectives of the proposed intelligent capacity estimation of lead-acid batteries.

碩士
國立成功大學
系統及船舶機電工程學系
106
In this research, we use two methods: Artificial Neural Network (ANN) and Support Vector Regression (SVR) to estimate the residual state-of-charge (SOC) of LiFePO4 Battery. Owing to existing Peukert’s effect when battery discharging, it may cause the error between the estimated discharging value and actual residual value. Therefore, the Peukert’s effect of the LiFePO4 battery should be calibrated before estimating the SOC. Before and after calibration, the average estimated error of the estimated discharging value and actual residual value is from original 2.12% to 0.49%, confirming that through the calibration, the more accurate experimental value can be obtained. In addition, we discuss the root mean square error (RMSE) of ANN and SVR according to the different discharging rate and discharging time. Under 0.5C and 1.0C and constant current constant voltage discharging conditions, the RMSE between the residual SOC and estimated SOC of the SVR was smaller than the RMSE of the ANN method. Finally, this research compares accuracy, efficiency and robustness of the above two methods for SOC estimation. From the conclusion, it is proved the SVR has higher reliability than the ANN.

碩士
國立清華大學
電機工程學系
103
Bio-medical field has drawn more and more attention in recent years. Functional electrical stimulation (FES) has been researched and applied to treat neuron disease, repair the physiological function of patients suffering from neuron damage. The stimulator is very close to neuron in all implantable devices, so safety is the critical point. Usually, residual charge on electrode/neuron interface after once stimulation is estimated as safety standard. We wish the residual charge can be reduced as low as possible. Because lower residual charge means the electrode electrolysis probability is smaller. Besides, some researches have proven that the stimulator with asymmetric stimulation output waveform can reduce neuron stimulation threshold charge effectively. However, stimulator with asymmetric output waveform is hard to reduce residual charge because of its difficult calibration through circuit. According to above design hard point, we use an improved current source control signal called sequential switching signal (S.S signal) to achieve lower residual charge when transferring asymmetric waveform. The stimulator has been fabricated using TSMC 0.18μm technology. Simulation result shows that stimulation current is up to 400μA and its residual charge mismatch percentage is less than 0.1%.

Die vorliegende Dissertation befasst sich mit der ramanspektroskopischen Charakterisierung von Galliumnitrid (GaN). Der Zusammenhang zwischen Waferkrümmung und mechanischer Restspannungen wird diskutiert. Mit Hilfe konfokaler Mikro-Ramanmessungen wurden Dotierprofile nachgewiesen sowie die Ladungsträgerkonzentration und -beweglichkeit ermittelt. Sämtliche Ramantensorelemente von wz-GaN wurden erstmals durch die Anwendung verschiedener Streugeometrien bestimmt. Eine neu entwickelte Vorwärtsstreuanordnung ermöglichte die Beobachtung von Phonon-Polaritonen. Es konnte gezeigt werden, dass von der theoretischen und experimentellen Betrachtung der Ramanstreuintensitäten dieser Elementaranregungen eindeutig das Vorzeichen der Faust-Henry-Koeffizienten von wz-GaN abgeleitet werden kann. Im Rahmen dieser Arbeit wurden alle Faust-Henry-Koeffizienten für GaN experimentell bestimmt.
This thesis focuses on special aspects of the Raman spectroscopical characterization of wurtzite gallium nitride (wz-GaN). The correlation between wafer curvature and residual stress is discussed. By means of confocal micro-Raman measurements doping profiles were detected as well as the density and mobility of free charge carriers were deduced. All Raman scattering cross sections of wz-GaN were determined the first time using different scattering configurations. A novel method for near-forward scattering was developed in order to observe phonon polaritons with pure symmetry. It is shown that the theoretical and experimental consideration of the Raman scattering efficiency of these elementary excitations allow for determining the sign of the Faust-Henry coefficients of wz-GaN unambiguously. The Faust-Henry coefficients of GaN were deduced from Raman scattering efficiencies of corresponding TO and LO phonons.

碩士
國立中山大學
電機工程學系研究所
90
This paper designs and implements a DSP based intelligent battery charger and residual capacity estimator. This system uses the proposed structure of the series circuit and battery equalizer with the intelligent fuzzy charge algorithm to charge batteries, and the improved coulometric measurement with accurate residual capacity estimation to estimate the residual capacity of batteries. Because of using the intelligent fuzzy charge algorithm can give different charging current depend on the difference of voltage, capacity and temperature of battery; And because of using the battery equalizer can adjust the voltage of battery. The charger can charge the battery safely without causing any damage. From the experimental results, the charger can achieve the purpose of fast and uniform charge with charging time six (6) to eight (8) hours, the residual capacity estimator can accurate estimate the residual capacity of batteries due to calculating the increment current and considering the aging factor.

Lee Chi-Fung.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 154-167).
Abstracts in English and Chinese.
Thesis Committee --- p.I
Statement --- p.II
Acknowledgements --- p.II
Abstract --- p.IV
摘要 --- p.VI
Content --- p.VIII
Abbreviations --- p.VIX
List of figures and tables --- p.XVII
Chapter Chapter 1 - --- Introduction --- p.1
Chapter 1.1 --- How are the thermophilic proteins stabilized? --- p.2
Chapter 1.1.1 --- Hydrophobic interactions --- p.2
Chapter 1.1.2 --- Hydrogen bonds --- p.4
Chapter 1.1.3 --- Electrostatic interactions --- p.6
Chapter 1.1.4 --- Reduction in ΔCP --- p.9
Chapter 1.2 --- Models of study: Thermococcus celer and yeast L30e --- p.12
Chapter 1.2.1 --- Thermococcus celer ribosomal protein L30e --- p.12
Chapter 1.2.2 --- Yeast ribosomal protein L30e --- p.13
Chapter 1.2.3 --- Comparison between the two proteins --- p.13
Chapter 1.3 --- Objective of this study --- p.20
Chapter Chapter 2 - --- Materials and Methods --- p.21
Chapter 2.1 --- General techniques --- p.21
Chapter 2.1.1 --- Preparation and transformation of competent E. coli DH5α and BL21(DE3)pLysS --- p.21
Chapter 2.1.2 --- Minipreparation of plasmid DNA (Invitrogen) --- p.22
Chapter 2.1.3 --- Spectrophotometric quantitation of DNA --- p.24
Chapter 2.1.4 --- Agarose gel electrophoresis --- p.24
Chapter 2.1.5 --- Purification of DNA from agarose gel (Invitrogen) --- p.25
Chapter 2.1.6 --- Restriction digestion of DNA fragments --- p.26
Chapter 2.1.7 --- Ligation of DNA fragments into vector --- p.26
Chapter 2.1.8 --- SDS-PAGE electrophoresis --- p.28
Chapter 2.1.9 --- Native-PAGE electrophoresis --- p.32
Chapter 2.2 --- Protein Engineering of Proteins --- p.35
Chapter 2.2.1 --- Polymerase chain reaction (PCR) --- p.35
Chapter 2.2.2 --- Site-directed mutagenesis of T. celer L30e --- p.37
Chapter 2.2.3 --- Protein engineering of yeast L30e --- p.42
Chapter 2.3 --- "Sub-cloning of mutation PCR fragment into expression vector, pET8c" --- p.45
Chapter 2.4 --- Expression of recombinant proteins --- p.45
Chapter 2.5 --- Purification of T. celer and its mutants --- p.46
Chapter 2.5.1 --- Extraction of proteins by sonication --- p.46
Chapter 2.5.2 --- Purification by ion-exchange chromatography --- p.47
Chapter 2.5.3 --- Purification by affinity chromatography --- p.48
Chapter 2.5.4 --- Purification by size exclusion chromatography --- p.49
Chapter 2.6 --- Purification of yeast L30e and its mutants --- p.49
Chapter 2.6.1 --- Extraction of proteins by sonication --- p.49
Chapter 2.6.2 --- Purification yeast L30e variants by washing the inclusion bodies --- p.50
Chapter 2.6.3 --- Purification by column chromatography --- p.51
Chapter 2.7 --- Thermodynamic studies of proteins --- p.52
Chapter 2.7.1 --- Guanidine-induced denaturation --- p.52
Chapter 2.7.2 --- Thermal-induced denaturation --- p.53
Chapter 2.7.3 --- Determination of protein stability curves by denaturant unfolding --- p.54
Chapter 2.7.4 --- ΔCP and protein stability curve determination by thermal unfolding --- p.55
Chapter 2.8 --- Media and buffer recipes --- p.56
Chapter 2.8.1 --- Medium for bacterial culture --- p.56
Chapter 2.8.2 --- Reagents for competent cell preparation --- p.58
Chapter 2.8.3 --- Nucleic acid electrophoresis buffers --- p.58
Chapter 2.8.4 --- Buffers for T. celer L30e variants purification --- p.59
Chapter 2.8.5 --- Buffers for yeast L30e variants purification --- p.59
Chapter 2.8.6 --- Reagents of SDS-PAGE --- p.60
Chapter Chapter Three - --- Purification of T. celer and Yeast L30e --- p.63
Chapter 3.1 --- Purification of T. celer L30e and its mutants --- p.63
Chapter 3.2 --- Purification of yeast L30e and its mutants --- p.72
Chapter Chapter Four - --- Thermodynamic Studies of T. celer and Yeast L30e --- p.77
Chapter 4.1 --- Introduction --- p.77
Chapter 4.2 --- Result --- p.79
Chapter 4.3 --- Discussion --- p.85
Chapter Chapter Five- --- Mutagenesis Study of a Charge Cluster in T. celer L30e --- p.92
Chapter 5.1 --- Introduction --- p.92
Chapter 5.2 --- Result --- p.92
Chapter 5.3 --- Structure determination of T. celer L30e mutants --- p.99
Chapter 5.4 --- Discussion --- p.105
Chapter Chapter Six - --- Alanine Scanning Mutagenesis of Charge Residues of T. celer L30e --- p.114
Chapter 6.1 --- Introduction --- p.114
Chapter 6.2 --- Result --- p.114
Chapter 6.3 --- Discussion --- p.121
Chapter Chapter Seven - --- Protein Engineering of T. celer and Yeast L30e --- p.132
Chapter 7.1 --- Introduction --- p.132
Chapter 7.2 --- Result --- p.136
Chapter 7.3 --- Discussion --- p.138
Chapter Chapter Eight - --- Concluding Remarks --- p.141
Appendix --- p.143
Reference --- p.154

博士
國立中興大學
環境工程學系
94
Residual chlorine change is commonly recognized as an excellent parameter in the world for studying drinking water quality in the distribution system. This research employed a model distribution system to investigate effects of pipe geometry and materials on the change of chlorine residuals. A field study on the residual chlorine change was also conducted to investigate spatial diversity of chlorine residuals in a real drinking water distribution system. Finally, a mathematical model that considers the hydraulic characteristics of pipe networks and the evolution of disinfectants was developed to predict residual free chlorine and combined chlorine in a real drinking water distribution system. According to the study of a model distribution system, hydraulic parameters such as dispersion number, dead zone and flow exchange rate are all connected to flow rate and distance. The study points out that the dispersion number goes down and the dead zone rate goes up when water flowing through sections where pipe diameter has sudden changes or when it flowing through the front and rear of obstacles on pipe walls in a slower speed, flowing through the rear of obstacles on pipe walls in a faster speed, and flowing through some deeper caves. The degree of residual chlorine distribution is related to these hydraulic characteristics parameters. For the reason to keep water quality in pipelines, it is better to reduce the existence of uneven sections as much as possible during underground pipeline settings. The study also points out the idea of reducing the effect of these uneven sections by slow flow spread effect or high speed turbulent flow eddy effect. Moreover, controlling the residual chlorine concentration effectively when it enters drinking water distribution system is another issue which engineers should be concerned about; the research has noticed that the lower residual chlorine concentration added at the beginning, the higher the decay rate occurred in the pipelines, and the more residual chlorine concentration dropped beyond anticipation. In the effect of pipe materials, the experiment has found the highest decay rate of residual chlorine in galvanized pipes and the lowest decay rate in PVC pipes; so it is necessary to frequently check the residual chlorine concentration in galvanized pipes which are often used to substitute for PVC pipes. This study applied factor analysis, cluster analysis and regression analysis to determine the spatial diversity of chlorine residual in the distribution system of Feng-Yuan city. The study pointed out the concentration variations in the distributing system could be classified by factor analysis, which is helpful to find out the cause. As for the monitor or typical sampling sites, the study suggested using the results of factor analysis can decide the station quantity and employing rotated factor matrix (which appeared in the analyzing process) to choose out those typical ones. In the research of concentration level, the cluster analysis is regarded as a simple but scientic method. By combining the results of factor analysis and cluster analysis, the worst case scenarios for drinking water quality in the distribution network could be determined. Besides, to cut down the time and efforts of the maintenance staffs, the study addressed regression analysis to set up the relation between typical sampling sites and others, and the concentration warning values of typical ones. In the simulation, not only combines Hardy Cross Method and Mass Balance Equations to build pipe network mode, also further employs the residual chlorine water quality parameters from the experimental data,linked up factor analysis to decide the node daily water uses, and considered the residual chlorine variations in finished water to advance the accuracy of the mode. It was validated by comparing its numerical solutions with the solutions of EPANET and the field sampling data of distribution. Practical application of the present model was also addressed. Ultimately, for the purpose of making the presentation of simulated residual chlorine change in the pipe network simpler and more understandable, this study takes the advantage of Web-GIS in the space analysis. Through the technology of layer slicing and color gradient and with showing simple and clear color variation of water quality, it is able to display the results of concentration variation which contains value, time and space spread characteristics all together and lift the stimulation result to be more readable and evaluative.

碩士
國立雲林科技大學
電機工程系碩士班
94
The research purpose of the thesis lies in improving the capability of traditional charger and presenting state of charge estimation strategy of higher accuracy. The pulse current charger in this research has the advantage of offering higher peak value which can shorten charging time to reach the goal of charging fast and also avoid the polarization phenomena produced while charging and tickle the voltage and current signal simultaneously, supervising whole charging course of the battery, avoiding the situation of excessive charging, ensuring the life of battery in order to increase the reliability of UPS. Besides, in battery state of charge estimation strategy, the research presents Curve Fitting mainly using different discharging capacity rate with different discharging current to estimate battery capacity and hence improve Coulomb state of charge estimation strategy to make battery to get accurate estimation of state of charge while discharging in heavy load and also make state of charge estimation strategy more suitable for different load. The circuit presented by the thesis adopts Digital Singal Processor (DSP240) as the core of controller, substantially decreases the volume of charger. Besides, the input power supply of this charger is utility, facilitating greatly its using or carrying, which contributes to the development of variety of electric equipments in the future. The experiment of the pulse current charger compares three different charge frequency and charge working cycle to find a more appropriate setting point. The experiment of Curve Fitting SOC Estimation uses five different loads to discharge, measuring the change of the curve of Curve Fitting SOC value, and compares and analyses the result of Coulomb SOC with error value of estimation after discharge ends.