Thèses sur le sujet « Switchable systems »

This work showcases the utility of switchable materials. Included are a switchable room-temperature ionic liquid, a switchable solvent, a switchable heterogeneous catalyst system, and a switchable gel. First, the switchable ionic liquid 2-butyl-1,1,3,3-tetramethylguanidium methylcarbonate is fully investigated. Its use in a complete chemical process (including reaction, separation, reformation, and recycle) is demonstrated with several reactions. Furthermore, its potential use for bitumen separation and purification and SO2 capture/isolation are discussed, and preliminary data is presented. Next, piperylene sulfone (PS), a switchable solvent, is synthesized and fully characterized. Anionic nucleophilic substitution reactions were performed in PS, the products were isolated in high yields, and then the PS was reformed for reuse. Then, we designed an immobilized fluorous microphase system that uses F-MonoPhos to induce high enantioselectivities as a switchable heterogeneous catalyst system. Finally, stable reversible polyethyleimine-CO2 gels have been synthesized with 1-octanol. Our findings indicate that PEI-1200/octanol/CO2 gels have potential as a possible drug carrier matrix for transdermal delivery applications.

Le travail de cette thèse de doctorat est axé sur le design, la synthèse et la caractérisation de systèmes moléculaires organiques et organométalliques luminescents dans le but de déclencher des processus de transfert photoinduit d’électron (PeT) ou d’énergie (EET) pour des applications dans les dispositifs optiques ou électroniques. Nous nous sommes d’abord intéressés aux molécules de type push-pull car elless’avèrent être des modèles intéressants pour l’étude du PeT. Nos systèmes sont construits autour de BτDIPY qui sert d’espaceur entre le donneur d’électron (julolidine ou triazatruxène) et l’accepteur d’électron (une unité dicyanovinyl). Les études en électrochimie et spectroscopie ont montrés un caractère à transfert de charge très prononcé. Entre autre nous avons synthétisé et étudié une série de ligands de type N^O (type base de Schiff) dérivés de la julolidine, une amine cyclique avec des propriétés électroniques très inattendues. Ces ligands, subissent des processus de transfert photoinduit de proton à l’état excité (ESIPT) et leurs spectres d’émission présentent une luminescence panchromatique. La compléxation desligands N^O au BF2 supprime l’ESIPT et augment les rendements quantiques de fluorescence. Les ligands derivés de la julolidine sont combinés avec d’autres unités chromophoriques i.e. Ir(III), Pt(II) afin de construire des systèmes multichromophoriques et stimuler des processus de EET entre les composants.Lors de ces travaux de thèse nous nous somme particulièrement intéressés aux systèmes moléculaires photocommutables dont l’unité centrale est un photochrome, le [1,3]oxazine. L’oxazine est combiné à un module moléculaire qui sert de donneur d’énergie et un module accepteur d’énergie choisie de façon optimale afin d’induire un transfert électronique d’énergie de manière contrôlé
The present doctoral thesis work deals with the design, synthesis and characterization of organic and organometallic luminescent molecular frameworks for triggering Photoinduced electron Transfer (PeT) and Electronic Energy Transfer (EET) processes for applications in optical andelectronic devices. First, we turned toward the organic push-pull chromophores because they are useful model systems for studying the mechanism of PeT process. We synthesized new push-pull systems bearing a dicyanovinyl fragment as the electron-acceptor and a strong electron-donorsuch as julolidine and triazatruxene covalently linked through a BODIPY dye bridge. Electrochemical and photophysical studies showed a pronounced charge transfer character within the new push-pull systems. Furthermore, we synthesized and studied a series of chelating N^O-type ligands (Schiff base-type), based on the strong electron-donating julolidine motif, displaying ESIPT process. Their luminescence profiles exhibited panchromatic luminescence band covering the whole visible spectrum. Complexation of N^O-site with boron difluoride fragment suppressed the ESPIT process and highly increased the fluorescence quantum yield. The N^O-chelating ligands were combined with Pt(II) chromophore, B(III) and Ir(III) such as to obtainmultichromophoric frameworks. According to the photophysical studies, EET processes were observed within the multichromophoric systems. We successfully obtained a new florescent switching triad constructed around a photochromic core, [1,3]oxazine, which bears an energy-donor and an energy-acceptor module such as to directly control the EET process

This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management. The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to be installed in a power system. This model also aims to design optimal switchable loads programs for a community. The penetration of the switchable loads versus the size of the BESS is investigated. Another model is developed to design an optimal load operation scheduling of a residential heating ventilation and air-conditioning system (HVACs). This model investigates the ability of HVACs to provide optimal demand response. The model also proposes a comfort/cost trade-os formulation for end users. A third model is proposed to incorporate the uncertainty of the photovoltaic power in a residential model. The model would nd the optimal utilization of the PV-output to supply the residential loads. In the first part of this research, mixed integer programming (MIP) formulations are proposed to obtain the optimal capacity of the (BESS) in a power system. Two optimization problems are investigated: (i) When the BESS is owned by a utility, the operation cost of generators and cost of battery will be minimized. Generator on/o states, dispatch level and battery power dispatch level will be determined for a 24-hour period. (ii) When the BESS is owned by a community for peak shaving, the objective function will have a penalty component for the deviation of the importing power from the scheduled power. MIP problems are formulated and solved by CPLEX.The simulation results present the effect of switchable load penetration level on battery sizing parameters. In the second part, a mixed integer programming (MIP) based operation is proposed in this part for residential HVACs. The objective is to minimize the total cost of the HVAC energy consumption under varying electricity prices. A simplied model of a space cooling system considering thermal dynamics is adopted. The optimization problems consider 24-hour operation of HVAC. Comfort/cost trade-o is modeled by introducing a binary variable. The big-M technique is adopted to obtain linear constraints while considering this binary variable. The MIP problems are solved by CPLEX. Simulation results demonstrate the effectiveness of HVAC's ability to respond to varying electricity price. Then, in the final part of this research, two Benders Decomposition strategies are applied to solve a stochastic mixed integer programming (MIP) formulation to obtain the optimal sizing of a photovoltaic system (PV) and battery energy storage system (BESS) to power a residential HVACs. The uncertainty of PV output is modeled using stochastic scenarios with the probability of their occurrence. Total cost including HVAC energy consumption cost and PV/battery installation cost is to be minimized with the system at grid-connected mode over eight hours subject to a varying electricity price. The optimization problem will nd the optimal battery energy capacity, power limit, a number of PV to be installed, and expected HVAC on/o states and BESS charging/discharging states for the next eight hours. This optimization problem is a large-scale MIP problem with expensive computing cost.

Ce travail a porté sur la préparation et l'étude de matériaux magnétiques fonctionnels en couches dans l'optique d'une utilisation dans des micro-systèmes magnétiques. Deux systèmes de matériaux ont été étudiés: le FePt, qui est un matériau magnétique dur, et le FeRh, qui a une transition antiferromagnétique-ferromagnétique proche de la température ambiante. Dans le cas du FePt, les influences de la concentration en Pt, de l'ajout de Cu et des traitements thermiques, sur la transition de la phase A1 désordonnée, de faible anisotropie, à la phase L10 ordonnée, de forte anisotropie, ont été étudiées. Les dépendances en température de l'aimantation spontanée et du champ d'anisotropie de la phase L10 ont été déduites de l'analyse des courbes d'aimantation. Le pic d'Hopkinson qui est lié aux processus d'aimantation de la phase L10 à l'approche de la température de Curie a été modélisé. Dans le cas du FeRh, les influences de la concentration en Rh et des traitements thermiques ont été étudiées. Une analyse thermodynamique des mesures d'aimantation et des mesures de calorimétrie différentielle a été effectuée. Enfin, des couches hybrides de FePt-FeRh ont été déposées sur des substrats pré-gravés, pour démontrer la potentialité d'utiliser le FeRh pour contrôler thermiquement le champ de fuite généré par le FePt.

Thesis advisor: Jeffery A. Byers
This dissertation discusses the development of an electrochemically switchable system for copolymer synthesis as well as surface modifications. In Chapter one, the usage of electrochemistry to control polymerization reactivities is introduced. In Chapter two, an electrochemically redox switchable polymerization for lactide and cyclohexene oxide will be presented. In Chapter three, a surface modification method based on the electrochemically redox switchable catalysis is discussed. The surface-anchored catalyst responds to applied electrochemical potentials towards two different ring-opening polymerizations to generate binary polymer patterns in one step. The method represents a facile way to generate polymer coatings on surfaces. In Chapter four, a discussion on the detailed kinetic analysis of an iron-catalyzed epoxide polymerization will be presented, the study allows us to unveil the importance of entropy-controlled reactions. In Chapter five, future perspectives on the electrochemically redox switchable catalysis will be discussed
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

Source de carbone la plus abondante du règne végétal et non concurrentielle de la chaîne alimentaire, la cellulose est une alternative aux ressources fossiles crédible pour le développement de nouveaux matériaux polymères. Néanmoins, à ce jour, les nombreux travaux décrits dans la littérature et visant la valorisation et la modification chimique de ce biopolymère fascinant ne répondent pas suffisamment, ou tout au moins que très partiellement, aux critères de durabilité. Pour répondre à ces critères de développement durable, le caractère renouvelable de la cellulose et les concepts de procédés propres et de chimie ‘verte’, doivent être réellement pris en compte. Ceci implique un choix réfléchi des solvants et réactifs utilisés, une maîtrise des procédés de modification chimique et bien évidemment une évaluation de la pertinence des produits formés, pour lesquels les propriétés obtenues doivent être innovantes et supérieures aux matériaux polymères existants. Cette thèse se divise en trois parties principales, à savoir la solubilisation, la régénération et la modification chimique de la cellulose. Tout au long de ce travail, une attention particulière a été portée sur la durabilité de sa transformation chimique pour viser l’élaboration de matériaux cellulosiques processables et aux propriétés innovantes. Dans la première partie de la thèse, un système composé d’un catalyseur organique nucléophile (DBU) et de CO2 a permis la dissolution rapide de la cellulose dans le DMSO. Une étude détaillée visant à optimiser le système DMSO-DBU-CO2 a été réalisée grâce à un suivi par spectroscopie infrarouge in situ. Ainsi, jusqu'à 8 % massique de cellulose ont pu être dissous en 15 minutes à 30 °C sous une faible pression de CO2 (2-5 bars). L’originalité de ce système commutable (fixation-relargage réversible du CO2), par comparaison aux autres solvants classiques de la cellulose, inclut une recyclabilité plus facile par simple dépressurisation du CO2 et une solubilisation rapide et douce, à plus bas coût, en comparaison aux systèmes utilisant les liquides ioniques. La mise en évidence de la création de fonctions carbonate par réaction avec différents composés électrophiles tels les halogénures d’alkyle a permis d’avoir une connaissance approfondie de ce système. L'optimisation réussie d'un système ‘propre’ permettant la dissolution de la cellulose nous a conduit à étudier sa régénération. Dans cet objectif, des aérogels de cellulose ont été préparés par un procédé de solubilisation, coagulation et lyophilisation. Différents paramètres ont été examinés tels la concentration en cellulose, le solvant de coagulation ou encore la nature et concentration en super-base (DBU-CO2), sur les propriétés des aérogels (densité, morphologie, taille des pores). Les résultats obtenus démontrent que des aérogels avec une densité entre 0.05 et 1,2 g/cm3, des porosités entre 92 et 97 % et des tailles de pore entre 1,1 et 4,5 μm ont été obtenus. Enfin, l’analyse des aérogels par microscopie électronique à balayage (SEM), a révélé la formation de réseaux de cellulose interconnectés et macroporeux. La modification chimique de la cellulose pour l’élaboration de matériaux processables aux propriétés innovantes fait l’objet de la troisième partie de la thèse. Cette partie est divisée en deux sous-parties: la dérivatisation de la cellulose par réaction de transestérification d’une part, et par réaction multi-composants, d’autre part. Dans la première sous-partie et gardant à l'esprit les principes de la chimie verte, la nature unique du système commutable DBU-CO2 amenant un changement d’hydrophilie du squelette cellulosique a permis l’utilisation directe de l’huile de tournesol pour la transestérification de la cellulose. [...]
As the most abundant source of carbon in our planet, without any competition with food or feed supplies, cellulose is a viable alternative to replace the widely used and unsustainable fossil-based polymers. However, the majority of researchers working on this fascinating biopolymer fail to incorporate sustainability considerations during cellulose chemical transformation to make materials. The consequence is a shift of the “environmental burden” to other stages of the process cycle. Therefore, to ensure sustainability, both the renewability feature of cellulose as well as sustainability considerations concerning its transformation processes are necessary. This implies to consider the solvent, the reactants, the derivatization process and the wastes produced as well as an evaluation of the suitability of the resultant products, for which relevant properties have to be obtained to compete with existing alternatives. This thesis is therefore divided into three main parts (solubilization, regeneration and derivatization of cellulose), and addresses the various concerns of sustainability during cellulose transformation with an end-goal of making processable materials.In the first part of the thesis, a sustainable solvent system for cellulose was investigated. In this regard, a detailed optimization study of the DBU-CO2 switchable solvent system was performed using in-situ infrared spectroscopy. Upon optimization, up to 8 wt.% cellulose could be dissolve within 15 min at 30 °C using low CO2 pressure (2-5 bar). What makes this solvent system sustainable, when compared to other classical cellulose solvents, includes: easier recyclability by simple release of the CO2 pressure, fast and mild solubilization and lower cost compared to ionic liquids. Finally, by successfully trapping the formed in-situ cellulose carbonate using an electrophile, a clearer understanding of this solvent system was established.The successful optimization of a sustainable solvent system for cellulose led to the second part of the thesis: the regeneration of cellulose. Here, the general solubilization and coagulation ways followed by freeze-drying was adopted to prepare cellulose aerogels. Various processing conditions such as cellulose concentration, coagulating solvent and super base, were investigated on their effect of the aerogels properties (density, morphology, pore size). The obtained results showed aerogels with densities between 0.05 and 1.2 g/cm3, porosities between 92 and 97 % and pore sizes between 1.1 and 4.5 μm. In addition, from scanning electron microscopy (SEM), open large macroporous inter-connected cellulose networks were observed.The derivatization of cellulose to make thermally processable materials is covered in the third part of the thesis. This part is divided into two sub-parts; transesterification and multicomponent reaction modification. [...]
Als Kohlenstoffquelle mit der größten Verfügbarkeit auf unserem Planeten, ohne Konkurrenz zur Lebens- und Futtermittelversorgung, stellt Cellulose eine interessante Alternative dar, um die vielfältig genutzten, nicht-nachhaltigen Polymere auf Erdölbasis zu ersetzen. Die Mehrheit der Forscher, die mit diesem faszinierenden Biopolymer arbeiten, vernachlässigt allerdings Überlegungen zur Nachhaltigkeit in die chemische Modifizierung von Cellulose bei der Herstellung von Materialien zu integrieren. Die Konsequenz dessen ist eine Verlagerung der Umweltbelastung auf andere Abschnitte des Prozess-Zyklus. Um Nachhaltigkeit sicherzustellen, sind deshalb sowohl der erneuerbare Aspekt von Cellulose als auch Überlegungen zur Nachhaltigkeit im Reaktionsprozess wichtig. Dies beinhaltet die Berücksichtigung des Lösungsmittels, die Reaktanden, des Derivatisierungsprozesses, die produzierten Abfälle sowie eine Beurteilung der Nachhaltigkeit der resultierenden Produkte, die relevante Eigenschaften aufweisen müssen um mit bestehenden Alternativen konkurrieren zu können. Diese Arbeit ist deshalb in drei Teile gegliedert (Löslichkeit, Rückgewinnung und Derivatisierung von Cellulose) und befasst sich mit den verschiedenen Aspekten der Nachhaltigkeit während der Umsetzung von Cellulose mit dem Ziel, verarbeitbare Materialien herzustellen.Im ersten Teil der Arbeit wurde ein nachhaltiges Lösungsmittelsystem für Cellulose untersucht. In diesem Zusammenhang wurde eine detaillierte Optimierungsstudie des DBU-CO2 schaltbaren Lösungsmittelsystems mittels in-situ Infrarot Spektroskopie durchgeführt. Nach der Optimierung konnten bis zu 8 Gew.-% Cellulose innerhalb von 15 min. bei 30°C und einem niedrigen CO2-Druck (2-5 bar) gelöst werden. Verglichen mit klassischen Lösungsmitteln für Cellulose weist dieses Lösungsmittelsystem verschiedene nachhaltige Aspekte auf: Einfaches Recycling durch entfernen des CO2-Drucks, schnelles und mildes Auflösen und geringere Kosten als ionische Flüssigkeiten. Durch erfolgreiches Abfangen des in-situ gebildeten Cellulose-Carbonats mit einem Elektrophil, konnte schließlich ein besseres Verständnis dieses Lösungsmittelsystems erreicht werden. Die erfolgreiche Optimierung eines Lösungsmittelsystems für Cellulose führte zum zweiten Teil der Arbeit: der Regenerierung von Cellulose. Hier wurde der bereits mit anderen Systemen beschriebene Weg von Lösen und Ausfällen, gefolgt von Gefriertrocknen übernommen, um Cellulose-Aerogele herzustellen. Verschiedene Bedingungen bei der Verarbeitung wie die Cellulose-Konzentration, Lösungsmittel zum Ausfällen und die Superbase und deren Effekt auf die Eigenschaften der Aerogele (Dichte, Morphologie und Porengröße) wurden untersucht. So wurden Aerogele mit einer Dichte von 0.05-1.20 g/cm3, Porositäten zwischen 92 und 97% und Porengrößen zwischen 1.1 und 4.5 μm erhalten. Zusätzlich wurden im Rasterelektronenmikroskop offene große und makroporöse, miteinander verbundene Cellulose-Netzwerke beobachtet. [...]

L'étude des matériaux à transition de spin constitue un important challenge du fait de leurspotentialités dans le traitement de l'information, notamment par voie optique. En effet, inscrire uneinformation par la lumière permet d'accéder à des vitesses de traitement extrêmement rapides. Leszones de stabilité de cette information photo-inscrite varient beaucoup avec la température. Cetravail de thèse a consisté à faire converger ces zones vers un même point via la rencontre entre lestransitions de spin thermique et photo-induite. Pour cela, nous avons utilisé deux approcheschimiques : la réalisation de solutions solides sur des systèmes très coopératifs et l'obtention denanoparticules photomagnétiques. Ce manuscrit détaille les résultats obtenus durant ce travail.

Ce mémoire s'articule autour de deux aspects complémentaires des processus qui accompagnent le transfert d'électron. Le cœur de ce projet concerne la valorisation de l'électrochimie moléculaire comme technique d'activation dans deux directions : activation de processus mécaniques ou de mouvements moléculaires dans des architectures commutables pour lesquelles un transfert d'électron fournit l'impulsion tout en permettant le contrôle et la lecture de l'état d'un système dynamique, et activation de processus chimiques pour lesquels l'électrochimie est exploitée en ingénierie moléculaire pour élaborer des molécules complexes et proposer une alternative efficace aux méthodes classiques de la synthèse organique. Le fil conducteur « activation électrochimique » est déroulé autour deux grandes classes de composés : les -dimères de dérivés du viologène et les macrocycles conjugués à base de pyrrole. Dans la première partie de ce mémoire, nous présenterons nos résultats en matière de systèmes moléculaires commutables dont les mouvements intramoléculaires et les propriétés sont activés et contrôlés par simple transfert d'électron tandis que la deuxième partie est centrée sur l'ingénierie électrochimique de porphyrines étendues
One of the most important key to the development of nanosciences lies in our ability to monitor, modify or control nanometric materials. The addition or removal of electrons to or from given molecular objects can find useful applications in numerous arena of nanosciences: as signal transcription of interactions processes, as impulse to trigger conformational, configurational or directional mechanical changes at the molecular level or even as a way to control and activate the reactivity of molecular building blocks in organic synthesis. This work deals with two complementary processes associated to electron transfer: molecular movements in switchable architectures and activation of molecular building blocks to form conjugated macrocyclic structures The first part of this research work is devoted to the synthesis of porphyrin-based molecular tweezers and of ferrocene-based molecular pivots. The dynamic properties of these switchable molecular objects; relying on reversible π-dimerization processes, have been investigated by spectroscopic, electrochemical and spectroelectrochemical methods. In the second part of this manuscript we show few examples of electrochemically driven synthetic procedures for preparation of expanded porphyrins. Unlike chemical oxidants, which must often be tested empirically for a given transformation, under electrochemical conditions, one has the opportunity to tune the reactivity of the pyrrole-based reagent via the choice of anodic voltage. We especially established that the use of bipyrrole allows for the clean and high-yield production of cyclo[8]pyrrole; the requisite electrochemically-induced cyclization of four bipyrrole building blocks likely involving an electrolyte-based templating effect. The success of this approach leads us to propose that analogous electrochemical oxidation processes could be used to generate a range of new expanded porphyrin products

This thesis begins with the introduction of solvents and their classification. The two solvent system studied here are switchable polarity solvents (SPS). A switchable polarity solvent is a liquid where its polarity can change between two forms by a trigger. These two solvent systems have several similar characteristics. First, they both require CO2 as the switching agent, which can be switched back by its removal with heat or N2. The first project is the continuation of previous work with using an amidine and alcohol mixtures as a switchable polarity solvent. The second project was the development of a new switchable polarity solvent that is based on the reaction of a secondary amine with CO2. Both solvent systems are fully characterized by many analytical techniques and examples of applications in chemical reaction and separation are outlined. The final project involves using these solvent systems, among others, in the separation of soybean oil. The aim was to use SPS technology to extract soybean oil from the bean flakes, and then separate the oil from the extracting solvent.
Thesis (Master, Chemistry) -- Queen's University, 2008-02-07 15:21:31.499

碩士
臺灣大學
機械工程學研究所
98
The electro-active polymer polypyrrole has small power consumption in aqueous working media. Due to its stability, incorruptibility and micromachining compatibility, polypyrrole plays an important role in developing micro/nano-actuators for biological in vivo applications. This thesis presents a flexible and reusable polypyrrole nano-valve array for controllable drug delivery. This system works in aqueous media even in the body fluid. It also provides mixable drugs. The system has extremely low power consumption and short response time. The nano-valves are formed by depositing polypyrrole by a novel method on an anodic aluminum oxide (AAO) film which has uniform nano-holes. This method ensures the uniformlity of the polypyrrole and the integrity of the AAO film. After the deposition, the nano-valves are integrated with a flexible print circuit. The valves are actuated through the oxidation and reduction of the polypyrrole. The reduction state of the polypyrrole makes sodium ions entering the polypyrrole and hence swells the polypyrrole. During the swelling situation, the polypyrrole becomes permeable. Hence the valve is opened. Conversely, the polypyrrole is compressed and becomes impermeable in the oxidation state. By controlling the open/close time with constant voltage, the diffusive characteristics of the nano-valves can be easily changed.

This thesis describes research done on novel biorefining systems for microalgae. Following the principles of Green Chemistry, the environmental impact of biomass processing can best be minimized by utilizing many components of the biomass, extracting them with innovative solvents and by getting maximum utility out of any solvent used. Switchable Hydrophilicity Solvents (SHSs) are a new class of solvents able to change their nature from hydrophobic to hydrophilic and vice-versa. In this work a SHS has been used to carry out the fragmentation and extraction of both hydrophobic and hydrophilic molecules from microalgal biomass in the two opposite-hydrophilicity states that the SHS can exhibit, thus bringing about a quite substantial simplification in the biorefining of the matrix and increasing the “useful effect” of the solvent itself that performs a second, complementary biomass extraction task during the regeneration stage. The proposed concept of “Circular Extraction” scheme has been validated with the N,N-dimethyl-cyclohexylamine on the oleaginous microalga Scenedesmus dimorphus, showing an extraction efficiency in the backward-mode of 52 % for proteins, 50 % for carbohydrates, and 93 % for lipids. In the second part of this work, the PCH (1,2-propanediol, choline chloride, water 1:1:1) Natural Deep Eutectic Solvent (NaDES) was used to treat microalgal biomass and carry out the extraction of cellular components, such as lipids, proteins, carbohydrates and photosynthetic pigments (chlorophylls and carotenoids) from the biomass itself. NaDES, i.e. mixtures formed by natural primary metabolites present in all organisms form intermolecular hydrogen bonds and, when mixed in a certain ratio, change their state from solid to liquid forming a eutectic system. Experiments were carried out based on different contact time between biomass and PCH: 24 and 72 hours, with and without pre-treatment with ultrasound. Biomass was shaken together with the PCH solvent in the presence of glass beads to promote the extraction efficiency. The analysis of the extract composition was carried out spectrophotometrically for pigments (chlorophylls and carotenoids), with biochemical assays for proteins and carbohydrates and gravimetrically for the determination of lipids. The results showed the ability of PCH, coupled with the mechanical destruction of cell walls, to solubilize a wide range of polar biomolecules at room temperature, precisely the 49 % of proteins, 46 % of carbohydrates, 15 % of neutral lipids, 16 % of chlorophylls and 32 % of carotenoids. In the last part of the experimental work is introduced and demonstrated the first SHS ever described in the open literature which is based on a natural deep eutectic solvent (NaDES). The innovative solvent system that is disclosed therein is based on natural metabolites, that are intrinsically safe, and on water solution of a hydrophilicity-switching compound whose toxicity is practically nil, therefore also duplicating this as the first finding of a practically bio-safe switchable hydrophilicity solvent. Together, the two findings mark a significant step toward the identification of a destination-neutral biorefining tool for the obtainment of biologic fractions from biomasses with a wide range of potential market applications. We demonstrated the potential of this novel system for fractionating proteins-, carbohydrates- and lipids-containing biomass by following the Circular Extraction biorefining scheme on microalgae. The present finding is quite a substantial step toward intrinsic safety in biomass processing.

In the last decade, the level of variable renewable energy sources (RESs) integrated in distribution network systems have been continuously growing. This adds more uncertainty to these systems, which also face many traditional sources of uncertainty, and those pertaining to other emerging technologies such as demand response and electric vehicles. As a result, distribution system operators are finding it increasingly difficult to maintain an optimal operation of such network systems. These challenges/limitations are, however, expected to be alleviated when distribution systems undergo the transformation process to smart grids, equipped with appropriate technologies such as energy storage systems (ESSs) and switchable capacitor banks (SCBs). These technologies offer more flexibility in the system, allowing effective management of the uncertainty and variability pertaining to most RESs (such as wind and solar PV power sources). This dissertation presents a stochastic mixed integer linear programming (S-MILP) model, aiming to optimally operate distribution network systems, featuring large-scale variable renewables, and alleviate the negative impacts of RESs on the overall performance of such systems by means of ESSs and SCBs. The optimization model is based on a linearized AC network model. Furthermore, the proposed operational model is formulated in a stochastic environment, particularly accounting for both variability and uncertainty pertaining to demand, wind and solar power productions. Such considerations allow one to make a more realistic analysis, under various operational conditions. The objective function of the proposed model is to minimize the sum of expected costs of operation, unserved power and emissions while meeting the most relevant technical and economic constraints. The analysis covers several issues, but with the perspective of maximizing the utilization level of variable RESs, and most importantly, without endangering the stability and integrity of the system as well as the quality of power delivered to the consumers. In this line, the dissertation presents an extensive analysis concerning the impacts of SCBs and ESSs of different efficiencies (either collectively or individually) in the system. In particular, the overall system performance in terms of costs, losses, voltages and energy mix has been extensively analysed, which is one of the main contributions of this dissertation. Simulation results indicate that strategically placed ESSs and SCBs can substantially increase the usage level of RES power, and simultaneously alleviate the negative impacts of RES intermittency in the considered system. For example, network losses are slashed by more than 70% and total system costs by 69%. Furthermore, the presence of ESSs and SCBs leads to as high as 96.1% share of RESs in the overall energy mix in the considered system. The energy imported through the substation in this case is limited to 3.9%, which means that the system operates in island mode for most of the time during the 24-hour period. This means that distribution network systems can go "carbon-free" by meeting a large portion of the demand using "cleaner" power locally produced.

In the last decade, the level of variable renewable energy sources (RESs) integrated in distribution network systems have been continuously growing. This adds more uncertainty to these systems, which also face many traditional sources of uncertainty, and those pertaining to other emerging technologies such as demand response and electric vehicles. As a result, distribution system operators are finding it increasingly difficult to maintain an optimal operation of such network systems. These challenges/limitations are, however, expected to be alleviated when distribution systems undergo the transformation process to smart grids, equipped with appropriate technologies such as energy storage systems (ESSs) and switchable capacitor banks (SCBs). These technologies offer more flexibility in the system, allowing effective management of the uncertainty and variability pertaining to most RESs (such as wind and solar PV power sources). This dissertation presents a stochastic mixed integer linear programming (S-MILP) model, aiming to optimally operate distribution network systems, featuring large-scale variable renewables, and alleviate the negative impacts of RESs on the overall performance of such systems by means of ESSs and SCBs. The optimization model is based on a linearized AC network model. Furthermore, the proposed operational model is formulated in a stochastic environment, particularly accounting for both variability and uncertainty pertaining to demand, wind and solar power productions. Such considerations allow one to make a more realistic analysis, under various operational conditions. The objective function of the proposed model is to minimize the sum of expected costs of operation, unserved power and emissions while meeting the most relevant technical and economic constraints. The analysis covers several issues, but with the perspective of maximizing the utilization level of variable RESs, and most importantly, without endangering the stability and integrity of the system as well as the quality of power delivered to the consumers. In this line, the dissertation presents an extensive analysis concerning the impacts of SCBs and ESSs of different efficiencies (either collectively or individually) in the system. In particular, the overall system performance in terms of costs, losses, voltages and energy mix has been extensively analysed, which is one of the main contributions of this dissertation. Simulation results indicate that strategically placed ESSs and SCBs can substantially increase the usage level of RES power, and simultaneously alleviate the negative impacts of RES intermittency in the considered system. For example, network losses are slashed by more than 70% and total system costs by 69%. Furthermore, the presence of ESSs and SCBs leads to as high as 96.1% share of RESs in the overall energy mix in the considered system. The energy imported through the substation in this case is limited to 3.9%, which means that the system operates in island mode for most of the time during the 24-hour period. This means that distribution network systems can go "carbon-free" by meeting a large portion of the demand using "cleaner" power locally produced.

碩士
國立交通大學
電子工程系所
95
Digital Rights Management (DRM) is a concept for controlling the distribution and consumption of digital media. As embedded multimedia devices are becoming popular, there are strong demands for the light-weight DRM systems that can run smoothly in a resource-limited environment. Because implementing the DRM in the embedded device becomes a trend, many companies create their private DRM on their device. However, this phenomenon causes the problem of interoperability between different DRM systems. In addition, from the consumer viewpoint, users can not use all kinds of DRM system on the same device. This is inconvenient for users. In this thesis, we propose a switchable DRM system to achieve the usage of different DRM systems on the same device. Before we design a switchable DRM system, we must understand the feature of the platform and analyze the structure of some DRM systems. After understanding them, we find an optimum integration of the platform and one DRM system. Then, we based on the designed DRM system to propose the concept of the DRM switchable design. We design an universal DRM module loader. This loader checks the validity of a loadable DRM module, and it defers all the other DRM tasks to the loaded module. This system integrates the concept of downloadable tools and the OMA architecture to provide a balance between flexibility and complexity. We also implement the mechanism on an embedded evaluation board to demonstrate its feasibility.

Metal contamination is a considerable environmental problem because metals are persistent contaminants. Ion exchange is one of the most commonly used treatment options for trace metal removal. This research develops and evaluates a redox active modified ion exchange system that has the potential to reduce the ionic strength of ion exchange regeneration streams. Poly-L-cysteine (PLC) was selected as the redox active, adsorbing functional group on the surface of a reticulated vitreous carbon (RVC) electrode. PLC is an excellent soft acid metal chelator and is unique in that its thiol groups can form disulfide bonds with each other. The reduction of available thiols changes the metal binding capacity of the peptide since the thiol is the primary binding group. RVC provides a macroporous conductive monolithic resin to support the peptide. An experimental apparatus was designed to study the properties of this system and estimate performance. Distinct oxidized and reduced states of PLC on the surface of the RVC were confirmed by changes in metal binding characteristics. Adsorption edges showed a sharper pH dependence for the reduced electrode compared to the oxidized electrode from pH 3-7. Adsorption isotherms performed at pH 7 showed increased capacity for the reduced electrode. The change was reversible by chemical and electrical reduction. This difference was confirmed at the molecular level with Cd- EXAFS of oxidized and reduced electrodes. A greater degree of cadmium-sulfur coordination was observed on the reduced electrode and a greater cadmium-oxygen coordination was apparant on an oxidized electrode. A multidentate adsorption model was developed to model the pH dependent behavior of cadmium adsorption on the PLC-RVC surface. Nickel adsorption showed increased adsorption in the oxidized state. The most likely explanation is increased carboxylate complexation. The electronically switchable ion exchange system (ESIE) provides a framework for modifying traditional ion exchange processes. The system has 5 to 10 times less specifc capacity than current ion exchange systems, but uses solutions 10-100 times lower in ionic strength for regeneration. Further studies on the effect of ionic strength on adsorption and current usage are necessary to compare the cost of the ESIE process to traditional ion exchange.
text

博士
元智大學
通訊工程學系
104
The aim of this paper is to design radio frequency identification (RFID) band antenna array. Single planar antenna elements were designed first, and then multiple antenna elements formed antenna arrays so as to obtain a good gain. Then, since electric feedback in transmission line is sinusoidal, the infeed points of antenna elements in each plane were connected to transmission line so as to be practically applied. Antenna array obtains large gain in general applications that can be optimized through near-field radiation optimization such that it can be extensively used in base station antennas and RFID-related applications. In this study, a new design of RFID reader antenna system was proposed that consisted of three parts: (1) radiation antenna elements, which is an 8 × 8 antenna array, were designed based on left circular-polarized micro-strip antenna elements; (2) vertical beam scanning, where the amplitude was controlled based on distributed standing wave in current, and the phase was controlled by the length of micro-strip line. Resistance conversion circuit was used to make sure that signal is being transmitted to every infeed point of micro-strip line at low loss conditions; and (3) horizontal beam scanning that was composed of phase compensation circuit and Butler matrix. For phase compensation circuit, the phase needed to be compensated was simulated for using coaxial cable of the corresponding phase in order to achieve phase compensation. For Butler matrix, it was a discrete Fourier conversion. The circuit could simultaneously produce eight orthogonal beams at different angles, and switch circuit was used to switch the beam positions. The new design of RFID reader antenna system can be used in transmission belt of department stores and malls, as well as airports. Because it can simultaneously produce several beams, a lot of time is saved compared with the traditional RFID design.

博士
國立臺灣科技大學
電子工程系
104
A novel real-time 2D/3D switchable autostereoscopic display system using an acousto-optic lens (AOL) is proposed. The AOL can replace the convectional lenticular lens and can function according to the Acousto-optic effect. A periodic change of refractive index occurs inside the AOL crystal due to the interaction between standing acoustic wave and acousto-optic material inside the crystal and hence creates a lens or lens array with the focal length and/or the pitch of the lenses that are adjustable through the tuning of the external acoustic wave. The viewer can adjust the viewing distance appropriately according to the properties of the display and location. With the same property, the system can also be adjusted with an appropriate interpupillary distance (IPD) for personal entertainment applications. The proposed system with adjustable lens pitch, can adapt to different display panels with various resolutions and/or composited images. The operation principle of the system is analyzed with a set of design parameters and a set of simulation results to facilitate the implementation of the system and to verify the validity of the approach.

博士
國立交通大學
電機資訊國際學程
105
Conventional 3D endoscopes consist of two lenses and two sensors, which enlarged the size of the instrument and have limitations imposed by stereo systems. We have successfully developed a hexagonal LC-lens array for capturing 3D images by using a single sensor using integral imaging. The significant finding from this study is that we propose convex-ring electrode to produces parabolic-like electric field distribution, thus lowering the focal length to less than 2.5 cm. which enables the endoscope to capture closer objects for medical applications, also better phase distribution and lower applying voltage. Because, the hexagonal LC lens is only switchable 2D/3D and not tunable in 2D mode we proposed a multi-functional liquid-crystal lens (MFLC-lens) for 2D and 3D switchable function. Importantly, this MFLC-lens can further modulate the focal length without mechanical movement in both 2D and 3D modes. To achieve multiple focal length lens functions, a novel structure with dual-layer electrode coated by a high resistive transparent film was developed. To enhance the quality of the taken image several polarized imaging techniques were investigated using linearly polarized, circularly polarized and quarter wave plate. Moreover, we simulated the wave-front employing Zernike polynomials to figure out the aberration in order to eliminate it.

Spring and damper characteristics determine to a large extent the ride quality and handling of a vehicle. Since the requirements for good ride and good handling are conflicting, adjustable suspension elements are developed. In this study a two-state semi-active hydro-pneumatic spring, in conjunction with a two-state semi-active hydraulic damper is investigated. A mathematical model of the spring/damper system is developed and verified with measured data. Two types of tests were performed on a prototype spring/damper unit, namely characterisation tests and single degree of freedom tests. The characterisation tests included characterising the hydro-pneumatic spring, the hydraulic damper, as well as the hydraulic valves in terms of valve response times. For the single degree of freedom tests, the step response, random input response and sine sweep response were determined. Simulation models of the characterisation setup, as well as the single degree of freedom setup were constructed in Matlab Simulink. A real gas, thermal time constant model was used for modelling the hydro-pneumatic spring, while a look-up table was used for the damper characteristics. A hydraulic flow model was developed from first principles and first order valve dynamics were also included in the models. Good correlation was obtained between measured and simulated data for the characteristation tests, as well as the single degree of freedom tests. The spring/damper model can be incorporated into a full 3D vehicle model in order to predict the ride and handling of a vehicle fitted with such a system.
Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007.
Mechanical and Aeronautical Engineering
unrestricted

碩士
國立成功大學
電腦與通信工程研究所
95
For the GSM and WLAN coexistence communication system, if we adopt these two oscillation signals directly, we need two oscillators. The chip area consumption is increased and thus the cost. So to combine these two oscillators into a reconfigurable structure is our goal. For the cost consideration, if we can integrate these two oscillators into a circuit, we can reduce the area consumption and the cost effectively. However, in the radio frequency integrated circuit design, electromagnetic interference (i.e. noise) causes serious problem. So to overcome the noise is important. In this thesis, we double the oscillation frequencies of the GSM/WLAN coexistence oscillator circuit, by utilizing a switchable inductor to switch the frequency between 3.6 GHz and 4.8 GHz. We use TSMC 0.18 um technology to realize the circuit design. There are two innovative ideas in this thesis: one is to use switchable inductor used for the frequency switching. The oscillation frequency is doubled and than we can make use of the frequency divider to reduce the phase noise. Another idea is to achieve the combination of GSM and WLAN oscillators into a reconfigureable structure.

碩士
國立臺灣大學
電子工程學研究所
107
This thesis studies power detectors at V-band and Q-band for millimeter wave RSSI system and is proposed to measure power in real time for wireless communication system. First, this thesis reviews literatures related to power detector circuits as well as introduces their structures, theory and applications. This thesis presents a low noise amplifier and two power detectors. This thesis first proposes a V-band low noise amplifier. It attains low noise and high gain by using source degeneration and double-transformer-coupling structure, along with common source structure to maintain outstanding linearity. The measured maximum gain achieves 21.5 dB with minimum noise figure 5.7 dB, IP1dB -21.4 dBm and IIP3 -10.6 dBm at 60 GHz. The amplifier consumes 16.3 mW dc power. Secondly, in order to convert rf power into dc output voltage with single circuit, this thesis proposes a V-band power detector by utilizing successive millimeter amplifiers and rectifiers in parallel to fulfill its design. Transformer-based common gate amplifier, common source amplifier and cascode rectifier along with switch control are used to increase detector’s dynamic range. The measured detectable range is from -33 dBm to over 5 dBm with dynamic range of at least 38 dB, maximum sensitivity of 14.5 mV/dB at 55 GHz and only 8.8 mW for quasi-dc power consumption. Finally, a Q-band power detector is proposed to meet the demand of sensitivity for next stage like ADC. Taking sensitivity as the first priority, Transformer-based common gate amplifier and common gate rectifier along with switch control are used to offer wider voltage range. The measured detectable range is from -20 dBm to 8.5 dBm, with dynamic range of 28.5 dB, with maximum sensitivity of 46 mV/dB at 34 GHz and only 13.2 mW for quasi-dc power consumption.

碩士
國立臺灣科技大學
電子工程系
104
In this paper, we propose the performance of a 2D/3D Switchable Autostereoscopic Display System with an input light source with different kind of polarizations. An acousto-optic lens with an implicit expression of its optical transfer function is employed in the 2D/3D Switchable Autostereoscopic Display System. Various performance results, the light intensity pattern, the crosstalk ratio and the IPD range are studied for light of different polarization. It is proved that using an acousto-optic lens, we can change its focal length in real time, have more flexibility in viewing distance, and also have comfortable three-dimensional perception.

博士
國立臺灣大學
生物科技研究所
101
Controlled gene delivery is a highly activated approach using viral or nonviral carriers. We used different strategies of gene transfer based on polymeric matrix or carrier for improved their efficiency. In the section of Chapter 2, we designed a biodegradable and pH sensitive polymeric matrix for localized delivery of recombinant adeno-associated virus serotype 2 (rAAV2). The rAAV2 containing the green fluorescent protein gene (rAAV2-GFP) were loaded into poly(ethylene glycol) (PEG) hydrogels, with and without incorporation of poly-L-histidine (polyHis). The fraction of polyHis used controlled the degree of swelling, water uptake and subsequent degradation of the hydrogels and release rate of rAAV2-GFP. As a result, release and transduction efficiency of the rAAV2-GFP from PEG-polyHis hydrogel in human HT-1080 fibrosarcoma cells increased significantly compared to a PEG hydrogel. Transduction rate can be controlled by the hydrogels’ polyHis concentration and is sensitive to localized decreases in pH consistent with inflammation. In the section of Chapter 3, we successfully constructed a high-efficient dual functional gene vector based on polyethylenimine (PEI)-based nonviral vectors. A small interfering RNA (siRNA)-loaded polyelectrolyte constructed with branched polyethylenimine (bPEI) and copolymer, consisting of PEG, histidine (His), and glutamic acid (Glu) was developed in order to provide a tumor acidosis-triggered delivery system with low cytotoxicity. In summary, we provide some insight into strategies developed for nonviral vectors to overcome intracellular barriers, using the strategy of pH-controllable to nuclear targeting, including the improvement of methods for polyplex preparation and the incorporation of endosomolytic agents or nuclear localization expression.

博士
國立清華大學
工業工程與工程管理學系
105
In addition to the application of Information & communication technology (ICTs) that is possible to enhance the functionality and add value to machine hardware, and more importantly, how to apply ICTs to solve the problems for the industry, such as assisting personnel in education and training. In the past there are many studies are virtual reality technology to develop the operational system for training of machinery and equipment, but different type, models or configurations in one training system cannot be built with switchable components. In particular, CNC machine tools can have different configurations and with different controllers, which makes the development of a virtual machine tool with switchable components has its necessity. It is the focus that Human-machine interface of all systems. The interface is key point for the training system development. For globalization, the trend of design, the operation interface of CNC machine tools has gradually been standardized by international standards. In this study, first step will to evaluate the legibility of ISO 7000 series symbols for switches or buttons. The evaluation results will serve as a reference for system development and improvement of real machine, and then use the questionnaire to explore the effect that effectiveness of training in the CNC machining practice course by virtual machine tools.

This work is focused on the development of sustainable and cost-effective solvents and separation processes, particularly by applying aqueous solutions of ionic liquids (ILs). It is shown the potential of ILs aqueous solutions as alternative solvents to extract value-added compounds from biomass, avoiding the use of the commonly applied volatile organic solvents, and their use as phase-forming components of aqueous biphasic systems (ABS) to develop reversible and/or integrated separation platforms. In the first set of results, it is demonstrated the high performance of ILs aqueous solutions to extract caffeine and hydroxymatairesinol (HMR) from spent coffee grounds (SCG) and Norway spruce knots, respectively. In the first work it is shown the relevance of the hydrotropy concept as the major factor behind the improved extraction performance of ILs aqueous solutions, whereas in the second work biocompatible ILs were applied and proposed to be used directly with the biomass extracts in nutraceutical and cosmetic applications. Still focused on the use of ILs aqueous solutions, these were then explored in the creation of reversible aqueous biphasic systems (ABS) as alternative separation platforms, followed by the development of integrated production-separation strategies. Transitions from monophasic to biphasic regimes were shown to occur by changes in pH and temperature (applied as external stimulus). Examples on their use in the separation of mixtures of amino acids and of nucleic acids from proteins are given. Finally, it is shown the applicability of reversible ABS as integrated production-separation processes. pH-driven ABS were applied in the production of hydroxymethylfurfural (HMF) from fructose at acidic media, followed by their separation at alkaline conditions (inducing the two phases separation). On the other hand, and taking advantage of the biocompatible nature of the ABS phase-forming components, thermoreversible ABS were used in biocatalytic processes. A reaction catalysed by laccase occurs in the homogenous solution, after which small temperature changes induce the two-phase formation and the complete separation of the enzyme from the respective product. These systems also allow the recovery and reuse of the ABS phases, contributing towards the development of sustainable production and separation processes. Although additional research on these solvents and systems scale-up feasibility is still required, the results here presented unveil the relevance of IL aqueous solutions as alternative solvents and on the development of efficient separation processes
Este trabalho compreende o desenvolvimento de solventes e processos de separação sustentáveis, eficientes e rentáveis, através da aplicação de soluções aquosas de líquidos iónicos (LIs). Em particular mostra-se o potencial de soluções aquosas de LIs como solventes alternativos para a extração de compostos de valor acrescentado a partir de biomassa, evitando portanto a utilização de solventes orgânicos voláteis, assim como a sua utilização na formação de sistemas aquosos bifásicos (SAB) como processos de separação. No primeiro conjunto de resultados demonstra-se que soluções aquosas de LIs apresentam uma elevada capacidade para extrair cafeína e hidroximatairesinol (HMR) de borras de café e de nós de abeto da Noruega, respetivamente. O primeiro trabalho nesta vertente mostra a importância do conceito de hidrotropia, atuando como o principal fator responsável pelo elevado desempenho das soluções aquosas de LIs na extração de compostos de valor acrescentado a partir de biomassa, enquanto que o segundo trabalho demonstra a utilização de LIs biocompatíveis, permitindo a utilização direta dos extratos de biomassa em aplicações nutracêuticas e de cosmética. As soluções aquosas de LIs também foram estudadas na criação de SAB reversíveis, como plataformas de separação alternativas, assim como no desenvolvimento de sistemas integrados de reação-separação. As respetivas transições de fase ocorrem por aplicação de estímulos externos, tais como pH e temperatura, e a sua aplicação foi demonstrada na separação de misturas de aminoácidos, e ácidos nucleicos e proteínas. Por fim, demonstra-se a utilização de SAB reversíveis como processos integrados de produção e separação. Os SAB reversíveis obtidos por alterações de pH foram aplicados na produção de hidroximetilfurfural (HMF) a partir de frutose em meio ácido, seguido da sua separação em condições alcalinas (induzindo a formação de duas fases). Por outro lado, e tirando partido da natureza biocompatível dos constituintes dos SAB, estudaram-se SAB reversíveis através da alteração da temperatura em processos biocatalíticos. A reação ocorre em meio homogéneo, catalisada pela lacase, onde pequenas alterações de temperatura induzem a formação de duas fases e a completa separação da enzima do respetivo produto. Estes sistemas permitem também a recuperação e reutilização das fases/constituintes dos SAB, contribuindo para o desenvolvimento de processos sustentáveis. Embora seja ainda necessária investigação adicional sobre a viabilidade destes solventes e sistemas para aplicação em larga escala, os resultados aqui apresentados mostram a relevância de soluções aquosas de LIs como solventes alternativos e no desenvolvimento de processos de separação
Programa Doutoral em Engenharia Química

碩士
國立臺灣科技大學
電子工程系
106
A 2D/3D switchable autostereoscopic display system which is constructed and investigated by the operation condition that the input light beam is Gaussian and polarized. With various polarization of light beam, a set of Mueller Matrixes are derived to represent the 2D/3D switchable autostereoscopic display system in a system representation. For difference acousto-optic interaction, different Mueller Matrixes are found for the isotropic and anisotropic acousto-optic interaction. Simulation results are provided to check the validity of the approach and show the feasibility of this approach.

碩士
國立成功大學
電機工程學系碩博士班
94
Recently, a multi-standard / multi-band terminal which combines the operation of GSM with WLAN has gained a lot of interest. The effective way to achieve the targets of low cost and low power for such terminals is to integrate the re-configurable RF blocks in direct conversion architecture. By using a direct conversion structure, we need different LO signals associated with the operation bands. The simplest and direct way is to integrate two VCO’s for GSM and WLAN respectively. However, the chip area consumption will be increased and thus the cost increases. For the cost down reason, it becomes important to develop a re-configurable VCO circuit which can provide the frequency either in the GSM (1.8 GHz) band or in the WLAN (2.4 GHz) band. In this thesis, we try to develop such a re-configurable VCO circuit by using TSMC 0.18 um 1P6M RF CMOS technology. By way of switching the capacitance array, the tuning range becomes wider without the degradation of phase noise. By way of switching the inductor, the center frequency of oscillation can be either in GSM band or in WLAN band. By applying the newly proposed switchable differential inductor developed from our laboratory, the integrated VCO circuit can possess the possibly smallest chip area. Therefore, the area-cost-efficiency can be achieved. The innovatory contributions of this thesis are as followed: The first, we propose the full integration of a new kind of switchable differential inductor to reduce the chip area consumption of a re-configurable dual-band VCO. The second, we confirm the integration possibility of such VCO circuit to a GSM and WLAN co-existence system.

Today, the advances in Complementary MetalOxideSemiconductor (CMOS) technology have guided the progress in the wireless communications circuits and systems area. Various new communication standards have been developed to accommodate a variety of applications at different frequency bands, such as cellular communications at 900 and 1800 MHz, global positioning system (GPS) at 1.2 and 1.5 GHz, and Bluetooth andWiFi at 2.4 and 5.2 GHz, respectively. The modern wireless technology is now motivated by the global trend of developing multi-band/multistandard terminals for low-cost and multifunction transceivers. Exploring the unused 10-66 GHz frequency spectrum for high data rate communication is also another trend in the wireless industry. In this dissertation, the challenges and solutions for designing a multi-band/multistandard mobile device is addressed from system-level analysis to circuit implementation. A systematic system-level design methodology for block-level budgeting is proposed. The system-level design methodology focuses on minimizing the power consumption of the overall receiver. Then, a novel millimeter-wave dual-band receiver front-end architecture is developed to operate at 24 and 31 GHz. The receiver relies on a newly introduced concept of harmonic selection that helps to reduce the complexity of the dual-band receiver. Wideband circuit techniques for millimeterwave frequencies are also investigated and new bandwidth extension techniques are proposed for the dual-band 24/31 GHz receiver. These new techniques are applied for the low noise amplifier and millimeter-wave mixer resulting in the widest reported operating bandwidth in K-band, while consuming less power consumption. Additionally, various receiver building blocks, such as a low noise amplifier with reconfigurable input matching network for multi-band receivers, and a low drop-out regulator with high power supply rejection are analyzed and proposed. The low noise amplifier presents the first one with continuously reconfigurable input matching network, while achieving a noise figure comparable to the wideband techniques. The low drop-out regulator presented the first one with high power supply rejection in the mega-hertz frequency range. All the proposed building blocks and architecture in this dissertation are implemented using the existing silicon-based technologies, and resulted in several publications in IEEE Journals and Conferences.