Dissertations / Theses on the topic 'S-ring'

Thienylenevinylene derived polymers have been extensively investigated for use in electrooptical devices. A precursor route and direct polymerisation methods to soluble thienylenevinylene homopolymers have been developed. These synthetic routes routinely yield little control of the polymer molar mass distribution and require further purification to remove the impurities and small oligomers. In this thesis, a new route to produce soluble polythienylenevinylenes is described via a ring-opening metathesis polymerisation (ROMP) it is extended to the preparation of PPV-PTV copolymers and block copolymers with a well-defined chain structure. Chapter 1 introduces the fundamentals of conjugated polymers and the general principle of the applications in organic light-emitting diodes and organic photovoltaic devices. The synthetic methods used to prepare poly(para-phenylenevinylene)s and poly(thienylenevinylene)s are introduced. Alkene metathesis is described and its use in ROMP examined. Chapter 2 focuses on the preparation and characterisation of poly(3,4-dialkylthienylenevinylene)s. Chapter 3 describes the preparation and characterisation of poly(para-phenylenevinylene-co-3,4-dioctylthienylenevinylene) copolymer. In Chapter 4, the preparation and characterisation of poly(para-phenylenevinylene)-block-poly(thienylenevinylene) copolymer are discussed. An overview of the work in this thesis and the potential for future work are presented in Chapter 5. All the experimental procedures are described in Chapter 6.

For a finite group G we study certain rings called k-S-rings, one for each non-negative integer k, where the 1-S-ring is the centralizer ring of G. These rings have the property that the (k+1)-S-ring determines the k-S-ring. We show that the 4-S-ring determines G when G is any group with finite classes. We show that the 3-S-ring determines G for any finite group G, thus giving an answer to a question of Brauer. We show the 2-characters defined by Frobenius and the extended 2-characters of Ken Johnson are characters of representations of the 2-S-ring of G. We find the character table for the 2-S-ring of the dihedral groups of order 2n, n odd, and classify groups with commutative 3-S-ring.

Poly(arylene ether sulfone)s (PAES) are important commercial polymers and have been extensively studied due to their excellent thermal and mechanical properties. However, some applications are still limited when good solvent resistance and low thermal expansion coefficient are required. There has been a continuous interest in developing new PAES based on new monomers or polymer modifications to obtain new properties or to enhance existing properties. In this dissertation, the synthesis, characterization and structure-property relationship of new 1,4-cyclohexylene ring containing PAESs were comprehensively studied. Different polymerization techniques were used to synthesize polymers with different segmental lengths. The monomer, 4,4'-[trans-1,4-cyclohexanebis(methylene)] bisphenol (CMB), was synthesized and fully characterized. Based on 4,4â -dihydroxy-p-terphenyl (DHTP), 4,4â -dihydroxybiphenyl (DHBP) and the CMB monomer, homopolymer and random copolymers of PAES were prepared with high molecular weights and high glass transition temperatures. Dynamic mechanical analysis (DMA) on these polymers showed multiple sub-Tg relaxations. A large increase in the ultimate elongation was obtained with the CMB and DHTP containing sample, which could be due to the strong sub-Tg relaxations observed from the DMA results. A series of four acid chloride monomers were synthesized and polymerized with phenol terminated PAES oligomers. Solution polymerization and pseudo-interfacial polymerization techniques were used to prepare both bisphenol-A (bis-A) based and DHBP based PAES oligomers. With the incorporation of the trans-1,4-cyclohexylene units, decreases in the glass transition temperatures were observed from both the bis-A based and the DHBP based polymers. However, melting transitions were only observed in the DHBP based trans-1,4-cyclohexylene containing PAESs. Crystallinity was confirmed by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). A mechanical property study of the high molecular weight trans-1,4-cyclohexylene containing polymer samples showed moderate ultimate elongation enhancements. A series of PAES-polyester multiblock copolymers were synthesized with both solution method and melt polymerization. In the solution method, phenol terminated PAES oligomers and the acid chloride terminated poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) oligomers were presynthesized and coupled in solution. The molecular weights of the polymer products obtained from the solution method were limited by solubility issues. Melt phase polymerization was employed to obtain high molecular weight polymers. Hydroxy ethoxy terminated PAES oligomers were synthesized and polymerized with 1,4-cyclohexanedimethanol (CHDM) and dimethyl terephthalate (DMT) in the melt. Polymers with high molecular weights were obtained. Tensile test results suggested that the mechanical properties of these polymers were dominated by the PAES components with polyester contents up to 20 wt%. Melting transitions were observed from polymers with higher polyester contents, and these polymers exhibited limited solubility in common organic solvents.
Ph. D.

Part I: Single sized, pure arylene ether macrocycles ranging from 30 to 60 atom ring sizes were synthesized in good yields (up to 83%) by the two component method under high dilution conditions. These macrocycles have unsymmetric structures containing sulfone/ketone or sulfone/phosphine oxide functional groups and have relatively low melting points. The melt ROP of the single sized macrocycles to form poly(arylene ether)s exhibits two stage characteristics: the first stage is very fast, driven by the large entropy difference between cyclics and linears; the second stage is very slow and is diffusion controlled due to the high viscosity created in the first stage reaction. The latter stage leads to incomplete polymerization at the low initiator concentrations (1-3 mol%). At high initiator concentrations (5-7 mol%), 100% conversion is reached due to improved initiator distribution in macrocycles; however, this reduces molecular weights of the polymers. The molecular weight is found to build up very rapidly, independent of conversion, reaction time and type of initiator. The ROP is initiated by CsF and alkali phenoxides. The efficiency of the alkali counterion is generally in the order of Cs+>K+>Na+, while a phenoxide initiator is more efficient than a fluoride initiator. It is also found that the Cs counterion leads to highest degree of crosslinking. The ROP of cyclic oligomeric mixtures is also reported for comparison; the study shows that the molecular weight depends on time and conversion, and that the conversion is sensitive to the content of linear impurities and the average ring size of cyclic mixtures. Part II: Polyrotaxanes are novel polymeric materials comprised of linear polymer molecules and threaded macrocycles with no covalent bond between the two components. With potential movements of the cyclic component and judicious combinations of the two components of different properties, these materials have brought interesting changes of physical properties, such as morphology, crystallinity, solubility, viscosity, etc. In this part of the dissertation, a new family of polyrotaxanes with poly(arylene ether)s as backbones and crown ethers as cyclic components are described. These include linear poly(arylene ether) based polyrotaxanes and hyperbranched poly(ether ether ketone) based polyrotaxanes; both are synthesized via aromatic nucleophilic substitution reactions. Preliminary studies show that these polymers exhibit great enhancement of solubility. The polymers form emulsions in water and methanol which are normally non-solvents for the poly(arylene ether) backbones. In some cases, they are even soluble in water to form a clear solution. The attempted syntheses of polyrotaxanes using aromatic macrocycles described in Part I was not successful, with no indication of threading.
Ph. D.

This thesis examines options for high capacity all optical networks. Specifically optical time division multiplexed (OTDM) networks based on electro-optic modulators are investigated experimentally, whilst comparisons with alternative approaches are carried out. It is intended that the thesis will form the basis of comparison between optical time division multiplexed networks and the more mature approach of wavelength division multiplexed networks. Following an introduction to optical networking concepts, the required component technologies are discussed. In particular various optical pulse sources are described with the demanding restrictions of optical multiplexing in mind. This is followed by a discussion of the construction of multiplexers and demultiplexers, including favoured techniques for high speed clock recovery. Theoretical treatments of the performance of Mach Zehnder and electroabsorption modulators support the design criteria that are established for the construction of simple optical time division multiplexed systems. Having established appropriate end terminals for an optical network, the thesis examines transmission issues associated with high speed RZ data signals. Propagation of RZ signals over both installed (standard fibre) and newly commissioned fibre routes are considered in turn. In the case of standard fibre systems, the use of dispersion compensation is summarised, and the application of mid span spectral inversion experimentally investigated. For green field sites, soliton like propagation of high speed data signals is demonstrated. In this case the particular restrictions of high speed soliton systems are discussed and experimentally investigated, namely the increasing impact of timing jitter and the downward pressure on repeater spacings due to the constraint of the average soliton model. These issues are each addressed through investigations of active soliton control for OTDM systems and through investigations of novel fibre types respectively. Finally the particularly remarkable networking potential of optical time division multiplexed systems is established, and infinite node cascadability using soliton control is demonstrated. A final comparison of the various technologies for optical multiplexing is presented in the conclusions, where the relative merits of the technologies for optical networking emerges as the key differentiator between technologies.

Depuis une dizaine d’années, avec la diversification des appareils connectés (PCs, Tablettes, TVs et Smartphones), l’écosystème Internet s’est drastiquement étendu. Aujourd’hui, 80 % du trafic IP mondial est concentré dans les centres de données. Pour répondre aux problématiques d’échelle des centres de données en terme de densité de bande passante, de consommation énergétique et de coût des interconnections, le développement de nouveaux émetteurs optiques est critique. L’objectif de cette thèse est de proposer et évaluer différentes architectures d’émetteur en photonique sur silicium afin de répondre à la prochaine norme de débit de 400 Gbit/s sur des transmissions de 2 kilomètres. Le modulateur électro-optique sélectionné est le modulateur silicium en anneau résonant. Il possède des avantages non négligeables: faibles dimensions, faible consommation énergétique, et il permet un multiplexage dense en longueurs d’ondes. Durant cette thèse, l’optimisation de l’émetteur optique a été faite de manière progressive: de la jonction active à l’émetteur complet. Cette première étude a identifié les différents compromis à faire sur les paramètres du modulateur en anneau afin de définir ses performances. Un model compact du modulateur a été créé, permettant d’optimiser le composant avec un temps de simulation très réduit. Puis, tout en utilisant le modèle compact, deux architectures d’émetteur ont été étudiées basées sur une architecture classique de la littérature. Elles sont basées sur la mise en série de 8 modulateurs en anneau, chacun modulant une longueur d’onde différente. La différence entre les deux architectures vient du format de modulation utilisé: la première est modulée avec des signaux sur deux niveaux électriques avec des signaux sur 2 niveaux électriques au format d’impulsions en amplitude (PAM-2) à 50 Gbaud ; alors que la deuxième est modulée avec des signaux sur 4 niveaux électriques au format d’impulsions en amplitude (PAM-4). Les deux solutions répondent aux demandes de performances de la norme 400 Gbit/s avec les mêmes points de compromis de fonctionnement. Finalement, de nouvelles architectures d’émetteur optique ont été proposées permettant de réaliser la modulation PAM-4. Contrairement aux solutions précédemment étudiées, ces architectures utilisent en entrée deux flux de bits en parallèle qui sont optiquement combinés pour générer en sortie une modulation PAM-4. Une première solution est basée sur la mise en série de deux modulateurs en anneaux. Cette architecture a été validée avec des caractérisations de transmission optique à 30 Gbit/s avec seulement 1 Vpp de tension de commande. Une seconde solution a ensuite été proposée, elle est basée sur l’utilisation de deux modulateurs mis en parallèle dans un interféromètre Mach Zehnder. De la même manière, des caractérisations de transmission à 30 Gbit/s avec 1.2 Vpp de tension de commande ont permis de valider le fonctionnement de l’architecture
Over the past decade, with the diversification of connected devices (PCs, Tablets, TVs and Smartphones), the Internet ecosystem has drastically extended. Today, 80 % world traffic is concentrated in the data centers where the data rate, the size and the cost is still growing. To address such scaling issues as bandwidth density, energy consumption and cost of the interconnects inside the data centers, the development of new optical transmitters is critical. The aim of this thesis is to propose and evaluate transmitter architectures using silicon photonics technology to address next 400 Gbit/s data rate standard over up to 2 kilometer links. The selected electro-optical modulator is the silicon ring resonator modulator which has substantial benefits: low footprint, low energy consumption and enables dense multiplexing. The optical transmitter architectures evaluations were successively optimized: from the active junction to the complete optical transmitter. This study identified the performances trade-offs impacted by the ring resonator modulator parameters. A compact model was generated to physically optimize the component in a reduced simulation time. Then, using the compact model, two transmitter architectures were studied based on classical architecture. Both are based on eight ring resonator modulators arranged in series modulating eight different wavelengths. The difference is the modulation format: the first one is electrically modulated at 50 Gbaud in 2-levels pulse amplitude modulation (PAM-2) and the second one at 25 Gbaud 4-levels pulse amplitude modulation (PAM-4). The two solutions fit the 400 Gbit/s performances demand with the use of the same trade-offs. Finally, new transmitter architectures were proposed to generate PAM-4 modulation. Unlike the previous architecture, they have in input two parallel bit streams which are optically combined to generate the PAM-4 modulation. The first solution is based on two silicon ring resonator modulator arranged in series. This architecture was validated through 30 Gbit/s transmission characterizations with only 1 Vpp. A second solution was then proposed, based on two silicon ring resonator modulators arranged in parallel in a Mach Zehnder interferometer. In the same way, transmission characterizations at 30 Gbit/s with 1.2 Vpp allows this architecture to be validated

For high-speed (e.g. more than 1 Gbit/s) filtration of network traffic there are available many of proprietary hardware solutions nowadays. But there are also a couple of free licensed projects that are specialized in high-speed packet processing on common hardware. The goal of thesis is to find such projects, verify that there are filtering tools based on these projects, try to filter 10Gbit/s network traffic by these tools and test them against various filtration settings. Implementation of packet filter that could be used for filtration of network traffic up to 10Gbit/s speed should be the output of this thesis.

L'objectif de notre travail a consisté en l'étude des mécanismes enzymatiques impliqués dans la libération de l'oxyde nitrique à partir des S-nitrosothiols (RSNO) et dans leurs effets vasorelaxants. Notre intérêt porte sur deux enzymes : la gamma-glutamyltransférase (GGT) et la protéine disulfure isomérase (PDI) car elles jouent un rôle important dans la dénitrosation des RSNO. Nous avons choisi d'étudier la dénitrosation de deux RSNO : le S-nitrosoglutathion (GSNO), un mononitrosothiol endogène et la S,S'-dinitrosobucillamine (BUC(NO)2), un nouveau dinitrosothiol. Nous avons synthétisé ces RSNO et nous avons vérifié la nature du produit obtenu par une caractérisation physico-chimique complète. Les analyses ont montré que ces RSNO présentent une pureté élevée (>97%) avec un niveau faible d'impuretés permettant leur utilisation dans des expérimentations biologiques. Les effets vasorelaxants des RSNO ainsi que l'implication des enzymes ont été évalués. Nos résultats montrent que la GGT et la PDI sont capables de dénitroser in vitro le GSNO. Le modèle ex vivo d'anneau aortique isolé de rat Wistar nous a permis de démontrer que l'effet vasorelaxant de GSNO (CE50=3,2±0,5.10-7 M) est dépendant de l'endothélium et de l'activité de la GGT et de la PDI. Concernant la BUC(NO)2, ce dinitrosothiol est catabolisé in vitro par la PDI, est un vasorelaxant plus puissant que la plupart des RSNO (CE50=2,2±0,2.10-8 M) et met en jeu l'activité de la PDI vasculaire. Nos travaux ont conduit à une meilleure compréhension des mécanismes enzymatiques impliqués dans les effets vasculaires des RSNO, ce qui permettra d'optimiser le choix de la meilleure RSNO à utiliser dans une finalité thérapeutique
The aim of our work was to evaluate the enzymatic pathways involved in the release of nitric oxide and in the vasorelaxant effect of S-nitrosothiols (RSNO). We were interested in two enzymes: the gamma-glutamyltransferase (GGT) and the protein disulfide isomerase (PDI), because they play an important role in RSNO denitrosation. Two RSNO were studied: S-nitrosoglutathione (GSNO), an endogenous mononitrosothiol, and S,S'-dinitrosobucillamine (BUC(NO)2), a new dinitrosothiol. We synthesized RSNO and we structurally characterized these products. The resulting data are consistent with the expected structure. Our products have a high purity (>97%) and a limited amount of impurities allowing their suitable use in biological experiments. The vasorelaxant effects of RSNO and the involvement of GGT and PDI were evaluated. The results indicate that purified GGT and PDI denitrosate GSNO in vitro. Furthermore, we demonstrated by using an ex vivo model consisting in an aortic ring isolated from Wistar rat that the vasorelaxant effect of GSNO (EC50=3,2±0,5.10-7 M) was dependent on the endothelium and GGT and PDI activities. As concerns BUC(NO)2, this dinitrosothiol catabolized in vitro by PDI, is more potent (EC50=2,2±0,2.10-8 M) than the most of nitrosothiols described in the literature. This vasorelaxation effect was dependent on PDI activity. In conclusion, our data led to a better understanding of the enzymatic mechanisms involved in the vascular effects of RSNO, which will permit, in physiopathological context, to optimize the choice of the best RSNO for use in a therapeutic purpose

[ES] El crecimiento de las plantas se ve afectado por el estrés abiótico, sequía, salinidad o altas temperaturas. La transducción de señales de estrés abiótico es fundamental para generar una respuesta fisiológica adecuada, que implica la participación de diferentes hormonas vegetales, siendo el ácido abscísico (ABA) el regulador hormonal crítico en la regulación de la respuesta de la planta a situaciones de estrés por déficit hídrico. La vía de señalización de ABA y los componentes principales están bien caracterizados molecular y bioquímicamente. Los receptores de ABA "Pyrabactin Resistance 1"(PYR)/"PYR1-LIKE" (PYL)/ "Regulatory Component of ABA Receptor" (RCAR) juegan un papel importante en la regulación cuantitativa de la señalización ABA tanto en semillas como en tejidos vegetativos. Aunque la función bioquímica de los receptores PYR/PYL/RCARs de ABA, está bien caracterizada, se conoce poco sobre otros aspectos con relevancia biológica, como sus modificaciones postraduccionales o la regulación de su vida media. Uno de los avances recientes en este campo ha sido el descubrimiento de una nueva familia de E3 ligasas llamadas RSL1/RFAs ("RING-finger-ABA-related") que consta de al menos 10 miembros, reguladores clave de la estabilidad de los receptores PYR/PYL/RCAR de ABA en tejidos de raíces y hojas, regulando su degradación en diferentes ubicaciones celulares. Un estudio detallado de esta familia génica reveló que RSL1/RFA se caracterizan estructuralmente por la presencia de tres dominios RING putativos en tándem, denominados "RING1-IN BETWEEN RING-RING2" (RBR), y en consecuencia pertenecen a la familia de E3 ligasas de tipo RBR. Cinco miembros de la familia RSL1/RFA, RSL1 y RFA6-RFA9, contienen un dominio TM en el extremo C-terminal, lo que sugiere que RFA6-RFA9 también se localizan en la membrana plasmática. Sin embargo, otros miembros de las E3 ligasas como RFA1-RFA5 carecen del dominio TM C-terminal y su caracterización funcional, así como su ubicación celular, aún no se conocen. Nosotros mostramos que la E3 ligasa RFA1 se localiza en núcleo y citosol, mientras que RFA4 muestra una localización específica en el núcleo promoviendo la degradación nuclear de los receptores ABA. Por lo tanto, los miembros de la familia RSL1/RFA interactúan con los receptores ABA en la membrana plasmática, el citosol y el núcleo, dirigiéndolos a su degradación a través de la vía endosomal/vacuolar (en el caso de RSL1) o el proteosoma 26S (para RFA1 y RFA4). Proporcionamos información sobre la función fisiológica de estas E3 ligasas de tipo RBR. Realizando tanto mutagénesis como ensayos bioquímicos para identificar la cisteína 361 (Cys361) en RFA4 como la Cys del sitio activo, que es una característica distintiva de las E3 ligasas de tipo RBR. Demostramos mediante análisis de inmunotransferencia del mutante con pérdida de función de rfa1rfa4 que los niveles endógenos de los receptores de ABA PYR1 y PYL4 aumentan en comparación con las plantas de tipo silvestre. Hemos identificado una enzima E2, "Ubiquitin Conjugating Enzyme 26" (UBC26), como la enzima nuclear canónica E2 que interactúa con la E3 ligasa RFA4 y forma complejos UBC26-RFA4-Receptor, formando agregados nucleares. Generamos alelos ubc26 con pérdida de función que mostraban una mayor sensibilidad a ABA y acumulación de receptores ABA en comparación con el tipo silvestre. En definitiva, hemos revelado un sofisticado sistema de ubiquitinación de receptores ABA en diferentes ubicaciones subcelulares llevado a cabo a través de la familia de E3 ligasas RSL1/RFA de tipo RBR. Por otro lado, hemos iniciado pruebas bioquímicas para identificar la S-acilación en el dominio TM de RSL1. Generando RSL1C334S, RSL1 C5S y RSL1C6S mediante mutagénesis y RSL1ΔTM que presenta una delección del dominio TM. Los estudios iniciales han demostrado que los residuos de Cys cercanos al dominio TM están S-acilados. Finalmente, generamos nu
[CA] El creixement de les plantes es pot veure afectat per l'estrès abiòtic, sequera, salinitat o altes temperatures. La transducció de senyals d'estrès abiòtic és fonamental per a generar una resposta fisiològica adequada, que implica la participació de diferents hormones vegetals, sent l'àcid abscísic (ABA) el regulador hormonal crític en la regulació de la resposta de la planta a situacions d'estrès per dèficit hídric. La ruta de senyalització d'ABA i els components principals de la ruta estan ben caracteritzats molecularment i bioquímica. Els receptors "Pyrabactin Resistance 1"(PYR)/"PYR1-LIKE"(PYL)/"Regulatory Component of ABA Receptor" (RCAR) exerceixen un paper important en la regulació quantitativa en resposta a l'estrès tant en llavors com en planta. Encara que la funció bioquímica dels receptors PYR/PYL/RCARs d'ABA, està ben caracteritzada en els últims anys, es coneix poc sobre altres aspectes amb rellevància biològica, com les seues modificacions postraduccionals o la regulació de la seua vida mitjana. Un dels avanços recents en aquest camp ha sigut el descobriment d'una nova família d'E3 ligases anomenades RSL1/RFAs ("RING-finger-ABA-related") que consta d'almenys 10 membres, que són reguladors clau de l'estabilitat dels receptors PYR/PYL/RCAR d'ABA en teixits d'arrels i fulles, regulant la seua degradació en diferents ubicacions cel·lulars. Un estudi més detallat d'aquesta família gènica va revelar que RSL1/RFAs es caracteritzen estructuralment per la presència de tres dominis RING putatius en tàndem, denominats "RING1-IN BETWEEN RING-RING2" (RBR), i en conseqüència pertanyen a la família d'E3 ligases de tipus RBR. Cinc membres de la família RSL1/RFA, RSL1 i RFA6-RFA9, contenen un domini TM en l'extrem C-terminal, la qual cosa suggereix que RFA6-RFA9 també es localitzen en la membrana plasmàtica. No obstant això, altres membres d'aquesta família d'E3 ligases com RFA1-RFA5 manquen del domini TM C-terminal i la seua caracterització funcional, així com la seua ubicació cel·lular, encara no ha sigut investigada. Vam mostrar que l'E3 ligasa RFA1 es localitza tant en el nucli com en el citosol, mentre que RFA4 mostra una localització específica en el nucli promovent la degradació nuclear dels receptors ABA. Per tant, els membres de la família RSL1/RFA interactuen amb els receptors ABA en la membrana plasmàtica, el citosol i el nucli, dirigint-los a la seua degradació a través de la vía endosomal/vacuolar (en el cas de RSL1) o el proteosoma 26S (per a RFA1 i RFA4). Proporcionem informació sobre la funció fisiològica d'aquestes E3 ligases de tipus RBR. Realitzant tant mutagènesis com a assajos bioquímics per a identificar la cisteïna 361 (Cys361) en RFA4 com la Cys del lloc actiu, que és una característica distintiva de les E3 ligases de tipus RBR. Hem demostrat mitjançant una anàlisi d'immuno-transferència del mutant amb pèrdua de funció de rfa1rfa4 que els nivells endògens dels receptors d'ABA PYR1 i PYL4 augmenten en comparació amb les plantes de tipus silvestre. D'altra banda, hem identificat un enzim E2, "Ubiquitin Conjugating Enzyme 26" (UBC26), com l'enzim nuclear canònic E2 que interactua amb l'E3 ligasa RFA4 i forma complexos UBC26-RFA4-Receptor, formant agregats nuclears. També generem al·lels ubc26 amb pèrdua de funció que mostraven una major sensibilitat a ABA i acumulació de receptors ABA en comparació amb el tipus silvestre. En definitiva, hem revelat un sofisticat sistema d'ubiquitinació de receptors ABA en diferents ubicacions subcel·lulars dut a terme a través de la família d'E3 ligases RSL1/RFA de tipus RBR. Hem iniciat proves bioquímiques per a identificar la S-acilació en el domini TM de RSL1. Hem generat RSL1C334S, RSL1 C5S i RSL1C6S mitjançant mutagènesis, així com RSL1ΔTM que presenta una delecció del domini TM. Els estudis inicials han demostrat que els residus de Cys pròxims al domini TM estan S-acilados. Final
[EN] Plant growth is affected by abiotic stress, drought, salinity or high temperature. Signal transduction of abiotic stress is crucial to generate an appropriated physiological response, which involves the participation of different plant hormones, being abscisic acid (ABA) the critical hormonal regulator in regulating the plant's response to situations of stress due to water deficit. The ABA signaling pathway and the major components of the pathway are well characterized molecularly and biochemically. Pyrabactin Resistance 1 (PYR)/PYR1-LIKE (PYL)/Regulatory Component of ABA Receptor (RCAR) ABA receptors play an important role in quantitative regulation of ABA signaling both in seeds and vegetative tissues. Although the biochemical function of the PYR/PYL/RCAR ABA receptors has been well established in recent years, little is known about other aspects with biological relevance, such as their post-translational modifications or the regulation of their half-life. One of the recent advances in this field has been the discovery of a new family of E3 ligases called RSL1/RFAs (RING-finger-ABA-related) that consists of at least 10 members, which are key regulators of the stability of PYR/PYL/RCARs in root and leaf tissues, and regulate the degradation of ABA receptors at different cellular locations. Further inspection of the gene family revealed that RSL1/RFAs are structurally characterized by the presence of three putative RING domains in tandem, named as RING1-IN BETWEEN RING (IBR)-RING2, and accordingly they belong to the RBR-type E3 ligase family. Five members of the RSL1/RFA family, that is, RSL1 and RFA6-RFA9, contain a TM domain at the C-terminal end of the proteins, which suggests that RFA6-RFA9 are also localized in plasma membrane. However, other members of this family of E3 ligases such as RFA1-RFA5 lack the C-terminal TM domain and their functional characterization, as well as their cellular location, has not been investigated yet. In this study we show that the E3 ligase RFA1 is localized both in the nucleus and in the cytosol, while RFA4 shows a specific localization in the nucleus promoting the nuclear degradation of ABA receptors. Therefore, we members of the RSL1/RFA family interact with ABA receptors at the plasma membrane, cytosol and nucleus, targeting them for degradation via the endosomal/vacuolar pathway (in the case of RSL1) or the 26S- proteasome (for RFA1 and RFA4). We provide information on the physiological function of these RBR-type E3 ligases, which are hardly explored in plants. Additionally, we performed mutagenesis and biochemical assays to identify Cys361 in RFA4 as the active site cysteine, which is a distinctive feature of RBR-type E3 ligases. We have shown by immunoblot analysis of the rfa1rfa4 loss-of-function mutant that endogenous levels of ABA receptors PYR1 and PYL4 are increased compared to wild-type plants. On the other hand, we have identified an E2 enzyme, Ubiquitin Conjugating Enzyme 26 (UBC26), as the canonical nuclear enzyme E2 that interacts with the E3 ligase RFA4 and forms UBC26-RFA4-Receptor complexes, forming nuclear aggregates. We also generated loss-of function ubc26 alleles that exhibited higher sensitivity to ABA and accumulation of ABA receptors compared to wild type. We have revealed a sophisticated ubiquitination system of ABA receptors in different subcellular locations carried out through the RBR-type RSL1/RFA family of E3 ligases. We have proceeded with the biochemical and genetic study of the different members of the family. We have started biochemical tests to identify the S-acylation in the TM domain of RSL1. To this end, we have generated RSL1C334S, RSL1 C5S and RSL1C6S by mutagenesis as well as RSL1ΔTM, a deletion of the TM domain. Initial studies have shown that Cys residues close to the TM domain are S-acylated. Finally, we have also generated new combined mutants: rsl1rfa1, rsl1rfa5, rfa1rfa5 and rsl1rfa1rfa5.
Fernández López, MA. (2021). Regulación de la señalización del ABA mediante mecanismos que controlan vida media y actividad de los receptores PYR/PYL [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172364
TESIS

The master’s thesis deals optimization of regenerative pump and axial pump with ring motors that are designed as a heart replacement. Analysis of the koncepts is performed which were made in previous master’s thesis. There is created a new design of construction and hydraulition with using flat motors based on the analysis. The compact assembly of two impeller was formulated that replaced left and right heart and it served as a function of heart replacement. A functional model of the pump is created, there is measured characteristics of impeller and results are compared with CFD analysis. The design requirements some parts of the axial pump are added and it’s deviced feasibility analysis.

Depuis le XXème siècle, la thérapie génique ouvre la voie au traitement de maladies d’origine génétique et de maladies acquises. L’introduction d’un polynucléotide dans les cellules présentant une mutation génétique permet de moduler leur fonctionnement. Afin de passer les différentes barrières biologiques et de rejoindre le noyau des cellules ciblées, l’ADN doit être protégé par un vecteur. Divers vecteurs ont été développés tels que les vecteurs polymériques à base de PEI. Malgré leur efficacité, ces vecteurs montrent des réactions immunogènes. Des fonctionnalisations sont développées pour réduire cette toxicité notamment par la formation de vecteurs furtifs. La stratégie standard de PEGylation montre, cependant, des limites nécessitant l’utilisation de nouveaux polymères hydrophiles. Dans ce contexte, la POxylation a été étudiée comme alternative à la PEGylation pour le design de nouveaux polyplexes. Une nouvelle méthode de synthèse de copolymères PEI-b-POx par hydrolyse sélective de copolymères à blocs poly(2-R1-2-oxazoline-b-2-R2-2-oxazoline) a été mise au point ainsi que la fonctionnalisation par des résidus histidine pour améliorer l’efficacité de transfection et diminuer la toxicité du vecteur polymère. Un ligand galactose a été greffé en fin de chaîne hydrophile pour induire un ciblage cellulaire. Les polymères synthétisés ont été utilisés pour former des polyplexes avec l’ADN via une méthode de formulation « par extrusion » avant de réaliser des tests de transfection in vitro et in vivo. Une réduction de la cytotoxicité a été observée lors de l’utilisation des copolymères PEI-b-POx en comparaison aux PEI tout en conservant une efficacité de transfection
Since 20th century, breakthrough in gene therapy paves the way for new therapeutic strategies against genetic disorders, cancers and neurodegenerative diseases. Cells with genetic mutation may have their cellular machinery modulated via the introduction of polynucleotides in their nucleus. Nevertheless, DNA needs to be protected by a vector to cross biological barriers and to reach targeted cell nucleus. Various types of vectors have been developed like PEI-based vectors. However, those efficient polymeric vectors exhibit a toxicity which can be lowered by PEG functionalization. Nevertheless, the well-known PEGylation approach shows limits requiring news hydrophilic polymers. In this context, POxylation was studied as PEG alternatives in the design of new pDNA containing nanovectors. A new synthetic strategy was developed with a selective hydrolysis of block poly(2-R1-2-oxazoline-b-2-R2-2-oxazoline) copolymers. The functionalization of the synthetized PEI-b-POx copolymers with histidine moieties was achieved, along with galactose grafting to induce cellular targeting or histidine grafting to improve endosomal escape. These polymers were used to form polyplexes with DNA via extrusion method and further biological testing via in vitro and in vivo transfection essays were performed. An efficient transfection was obtained with a reduction of the cytotoxicity for PEI-b-POx copolymers compared to PEI

Made available in DSpace on 2017-05-12T14:48:28Z (GMT). No. of bitstreams: 1 Patricia de Oliveira Drechmer.pdf: 703873 bytes, checksum: c5f64d1a8f42cf596ce9e2edd113b6b8 (MD5) Previous issue date: 2005-08-01
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This paper shows the comportment of solar radiation global, direct and diffuse radiation at Cascavel, classifies the sky s cover in function of the cloudiness index and studies the applicability of the numeric correction of RICIERI (1998) on diffuse radiation measured with a shadow ring. The research was done at meteorological experimental station of UNIOESTE, Cascavel. The solar radiation components were monitored from January 03, 2001 to February 14, 2003. The global radiation was monitored by a pyranometer KIPP & ZONEN-CM3 and the direct radiation were monitored by a pyrheliometer EPPLEY-NIP coupled to a solar tracer. The diffuse radiation was monitored by the difference between global radiation and direct radiation projected over the horizontal surface and by a pyranometer covered by a shadow ring. The monthly average levels of the global, direct and diffuse irradiations were 51,8%, 31,7% and 20,17% of the irradiation over the atmosphere s top. The diffuse irradiation measured by the difference method and by the shadow ring method corrected by DRUMMOND s factor and compared through the relative daily deviation. It was observed that, in 94% of the days, the diffuse radiation by DRUMMOND s factor was lower than the difference method. The deviations were higher for cloudless days (19,82%), than for partially cloudy days (9,55%) and cloudy days (2,68%). The RICIERI s correction (1998), that proposes the correlation of diffuse irradiation without correction with the diffuse irradiation by the difference method, was used and the linear function Rd=0,16545+1,21715R d was found to correct the diffuse by the shadow ring method. This correction increases the precision of the diffuse fraction obtained by shadow ring, decreasing the average relative deviation from 11,79%, when the DRUMMOND s correlation was applied, to 7,37%. In order to increase the model s precision, it was proposed the partial numeric equation fitted in function of the sky s cover. It was verified decrease mean values of relative deviation, when compared with the DRUMMOND s correction: 4,8% in cloudless sky, 4,66% in partially cloudy sky and, 4,6% in cloudy sky. The average relative deviation was 4,68%. The diffuse solar radiation measured on Cascavel-PR and corrected by RICIERI s numeric function, determined to region of Botucatu - SP, shows relative deviation to cloudy sky, partially cloudy sky and cloudless sky, respectively, 4,6%, 4,8% and 5,29%, suggesting that the functions developed to Botucatu - SP tend to be independent from the locality.
O presente estudo caracteriza o comportamento da radiação solar global, direta e difusa na cidade de Cascavel, classifica o tipo de cobertura do céu em função do índice de claridade e avalia a aplicabilidade da função numérica de RICIERI (1998) na correção da radiação solar difusa obtida com do anel de sombreamento. As componentes da radiação solar foram monitoradas durante o período de 3 de janeiro de 2001 a 14 de fevereiro de 2003 na Estação Experimental Agrometeorológica da UNIOESTE, Campus de Cascavel. Na medição da radiação global e difusa foi utilizado um piranômetro KIPP & ZONEN-CM3 e para medir a componente direta foi utilizado um pireliômetro EPPLEY-NIP acoplado a um rastreador solar. A radiação difusa foi monitorada de duas formas: através da diferença entre a radiação global e a radiação direta projetada no plano horizontal e através de um piranômetro sombreado por um anel. Os níveis médios mensais das irradiações global, direta na incidência e difusa, foram respectivamente, 51,8%, 31,7% e 20,17% da radiação incidente no topo da atmosfera. Os níveis da irradiação difusa medidos pelo método da diferença e anel de sombreamento corrigido pelo fator de DRUMMOND (1956) foram monitorados e comparados utilizando o desvio relativo diário. Foi verificado que, em 94% dos dias, a radiação difusa corrigida por DRUMMOND foi inferior à obtida pelo método padrão. Os desvios são maiores para dias de céu limpo (19,82%), que para céu parcialmente nublado (9,55%) ou nublado (2,68%). Foi empregado o método de correção sugerido por RICIERI (1998), que propõe a correlação entre a irradiação difusa sem correção e a irradiação difusa de referência, e a função numérica linear Rd=0,16545+1,21715R d foi proposta. Essa correlação melhora em cerca de 37% a correção da fração difusa, diminuindo o desvio relativo médio de 11,79%, calculado para o método de DRUMMOND, para 7,37%. As funções numéricas parciais, propostas em função do tipo de cobertura do céu, diminuem significativamente o valor do desvio relativo médio, quando comparada ao fator de correção de DRUMMOND: 4,80% para céu limpo, 4,66% para céu parcialmente nublado e 4,60% para céu nublado, sendo o desvio relativo médio igual a 4,68%. A radiação solar difusa medida em Cascavel - PR e corrigida com as funções numéricas de RICIERI, determinadas para a região do município de Botucatu - SP, mostraram desvios relativos médios para dias de céu nublado, parcialmente nublado e limpo, respectivamente, 4,60%, 4,80% e 5,29%, sugerindo que estas tendem a independer da localidade.

The design of plastic parts for presure valve filter (Reverse rinsing filter combination with pressure reducing valve. Fine filter and rotary connector flange for installation in horizontal or vertical pipe work). Optimization of fixture of existing device Additional function record of cleaning filter (date rocord) Optimization of easy makeability Design of concept of filter base on study from external company Description of function of device Proposal of design changes of selected components Creation of 3D model and drawings of selected components Stress – strain analysis in Pro/Mechanica Simulation of molding process with using Plastic adviser tool Basic calculation of hydraulic mechanism

This master thesis deals with qualifications of the catalytic materials for positive electrode low-temperature fuel cells. The teoretical part focuses on the physical and chemical properties of low-temperature fuel cells. There are described methods of hydrodynamic RDE and RRDE. RRDE study utilizes methods linear and cyclic voltammetry for qualifying performance of catalytic materials and presentation of results. The practical part describes the preparation various types of carbon materials. There are monitored the oxygen reduction using RRDE. Catalytic materials are evaluated: CV, stability, kinetic parameters, creation of intermediate H2O2 and kinetics of electrode reactions.

The thesis deals with basic principles of metamaterials, which exhibit unusual properties in microwave applications (e.g., negative permittivity and permeability). Different type of metamaterial antennas and parameters of such antennas are described in the thesis.

The aim of this thesis is to address issues concerning the sealing of the lid for the primary collector within the steam generator (SG) of the nuclear power plant VVER 440. These steam generators are sealed in the original design by nickel rings. Modifying the existing method of sealing by a new type of sealing material, primarily from expanded graphite, can significantly reduce the pressure in the sealing surface and also stress in bolts and flanged joints. The new solution of sealing between the joint of collector and the lid should extend the life of joints and thus the nuclear and technical safety. The text is divided into the theoretical and computational part. A principle of the SG, the SG design, and a description of the joint and lid are mentioned in the theoretical part. The computational part shows calculations of the new joint, the original one, and comparison of both solutions in terms of technical and nuclear safety. The work contains drawing of the new joint.

The main purpose of this thesis is the modification of the original flange gasket of the VVER1000 pressurizer manhole. Then the construction and function of the pressurizer itself is described, together with detailed calculations of the original and new modified gasket to meet the ČSN EN 1591 standard together with a description of the legislation that has to be followed in the calculations. The comparisons of both gasket types together with main conclusions are placed in the last section of this thesis.

Certaines maladies rares d’origine génétique, peuvent être traitées par une thérapie nommée « thérapie génique » qui consiste à introduire un polynucléotide (ADN ou ARN) à l’intérieur des cellules pour moduler leur activité dans un but thérapeutique. L’emploi d’un vecteur capable de protéger le polynucléotide et de le véhiculer jusqu’au noyau des cellules cibles est nécessaire. La polyéthylèneimine (PEI) est actuellement le polymère cationique de référence dans ce domaine. Cependant, en raison de sa toxicité importante, de nombreuses études visant à modifier la PEI sont toujours en cours pour améliorer ses propriétés. Entre autre, il a été montré que des architectures compactes conféraient de meilleures propriétés aux polymères. Dans ce contexte, des PEI en étoile ont été synthétisées pour la première fois. A cette fin, des précurseurs de poly(2-oxazoline)s en étoile ont été préparés et leur architecture a été confirmée par des analyses par chromatographie d’exclusion stérique et des études cinétiques. Des PEI de masse molaire (8, 16 et 25 K) et d’architecture (linéaire, à 3 et 4 branches) variables ont ensuite été obtenues par adaptation du protocole d’hydrolyse utilisé pour les polymères linéaires. La transfection de cellules CFBE et HepG2 par des polyplexes à base d’ADNp et de ces polymères a été évaluée. L’influence de la masse molaire et de l’architecture a été étudiée. Pour finir, la modification de ces PEI par des résidus histidine connus pour améliorer l’efficacité de transfection des lPEI a été réalisée avec succès. La synergie espérée entre les modifications chimique et architecturale n’a pas été observée pour la transfection des cellules HepG2 in vitro
Some rare diseases of genetic origin can be treated by a therapy called "gene therapy" which consists in introducing a polynucleotide (DNA or RNA) into the cells to modulate their activity for therapeutic purposes. The use of a vector able to protect the polynucleotide and to transport it to the nucleus of the target cells is necessary. Polyethyleneimine (PEI) is currently the cationic polymer gold standard in this field. However, due to its high toxicity, many studies aiming to modify PEI are still underway to improve its properties. Among other things, it has been shown that compact architectures give better properties to polymers. In this context, star PEI were synthesized for the first time. To this end, star poly(2-oxazoline)s precursors were prepared and their architecture was confirmed by steric exclusion chromatography analyses and kinetic studies. PEI of variable molar mass (8, 16 and 25 K) and architecture (linear, 3 and 4 arms star) were then obtained by adapting the hydrolysis protocol used for linear polymers. The transfection of CFBE and HepG2 cells with polyplexes based on pDNA and these polymers was evaluated. The influence of molar mass and architecture was studied. Finally, the modification of these PEI with histidine moieties known to increase lPEI transfection efficiency was successfully achieved, however, the expected synergy between the chemical and architectural modifications was not observed for the in vitro transfection of HepG2 cells

This diploma thesis contains description of design of robotic cell, which automates process of glass neck ring welding. Robot arm is used as manipulator of part between entry conveyor, induction heating, automatic welding machine and outgoing palette. Construction process contains of making layout of the cell, design of needed workstations and minimalize risk of harm for human operator. The final construction design is simulated to verify robot reach and find manipulation time.

Motivation of this master‘s thesis is solution of practical problem of the newly developed slewing ring for tram Škoda, type: 15T. Next impulse for thesis creation was the possibility to extend product range of roller bearing ZKL. There is processed strain – stress analysis of bearing inner design making use the finite element method (FEM). Obtained results are compared with classic approach based on the Hertz theory. Important aim of this work is three main parameters optimal establishment: rolling element diameter, arrangement radius and number of rolling elements. Optimization job is realized by solutions of direct tasks with different parameters. With regard to necessity of detailed stress analysis and conservation of reasonable computational time it was chosen approach of combination global and local FEM model. It was used pre/postprocessor PATRAN and solver MARC for solution of strain and stress analysis. Analytic solution was accomplished in software EXCEL.

Les poly(hydroxyalcanoate)s (PHAs), et notamment les poly(hydroxybutyrate) (PHB) et poly(malolactonate d’alkyle)s (PMLARs), sont des polyesters biosourcés et biodégradables intéressants pour des applications comme polymères de commodité ou dans le domaine médical. La polymérisation par ouverture de cycle (ROP) de β-lactones est une stratégie très efficace pour la synthèse de PHAs, permettant un contrôle de la masse molaire, de la microstructure et de la fonctionnalité des polymères. Ainsi, il s’agit de moduler ces paramètres pour optimiser les propriétés physico-chimiques des polymères. Cette approche a permis de synthétiser de nouveaux (co)polymères PHAs, présentant des fonctionnalités, des tacticités (atactiques, syndiotactiques) et des topologies (copolymères à blocs, aléatoires et alternés) originales. L’utilisation de différents systèmes catalytiques et amorçants a permis la synthèse de PHAs α-base, ω-crotonate téléchéliques atactiques, mais également des premiers exemples de PMLARs (R = allyle, benzyle et méthyle) syndiotactiques. De la même manière, l’ingénierie catalytique offre la synthèse de copolymères P(BL-b-MLABe) et P(BL-ran-MLABe) par copolymérisation séquentielle et simultanée du couple rac-BL/rac-MLABe. Enfin la copolymérisation simultanée des comonomères (R)-MLAAll/(S)-MLABe en présence de complexe d’yttrium a conduit à la synthèse de copolymères alternés P(MLABe-alt-PMLAAll). Leur modification chimique post-polymérisation ouvre la voie à la synthèse de PHAs portant des fonctions latérales réactives alternées
Biobased and biodegradable polyesters of the family of poly(hydroxyalkanoate)s (PHAs), and more specifically poly(hydroxybutyrate) (PHB) and poly(alkyl malolactonate)s (PMLARs), display a wide array of valuable uses ranging from commodity plastics to biomedical applications. Ring-opening polymerization (ROP) of β-lactones is an efficient strategy for the synthesis of PHAs with control of the molar mass, the microstructure and the functionalities of polymers. So, it is a question of modulating these parameters to optimize the physicochemical properties of polymers. This approach allowed the synthesis of new (co)polymers PHAs, exhibiting original functionalities, tacticities (atactic, syndiotactic) and topologies (block, random and alternating copolymers). Tunable catalytic/initiating systems afford the synthesis of α-base, ω-crotonate telechelic atactic PHAs and of the first examples of syndiotactic PMLARs (R = allyl, benzyl and methyl). Similarly, catalytic engineering offers the synthesis of P(BL-b-MLABe) and P(BL-ran-MLABe) copolymers from the simultaneous and sequential copolymerization of the comonomers rac-BL/rac-MLABe. Finally, simultaneous copolymerization of the comonomers (R)-MLAAll/(S)-MLABe, in the presence of yttrium complexes, leads to the synthesis of alternating copolymers P(MLABe-alt-PMLAAll). Further post-polymerization modifications of these copolymers foresee a route towards a new class of functionalized alternating PHAs

A finite group H is said to fuse to a finite group G if the class algebra of G is isomorphic to an S-ring over H which is a subalgebra of the class algebra of H. We will also say that G fuses from H. In this case, the classes and characters of H can fuse to give the character table of G. We investigate the case where H is the dihedral group. In many cases, G can be completely determined. In general, G can be proven to have many interesting properties. The theory is developed in terms of S-ring of Schur and Wielandt.

The aim of this thesis is to analyze the current state of the manufacturing process of the company ALFA s.r.o. Moravská Třebová, to submit own suggestions for the introduction of lean production to save time, costs and strengthening of the quality in the company and establish the conditions of implementation, in which is possible to implement specified proposals. The operational objective is also an explanation of benefits that gets the company after implementation of these proposals. The first part gives an overview of lean manufacturing methodologies and with using of selected methods and workflow analysis are determined in the second part the proposals. After their implementation the company can save time, reduce costs and strengthen quality for the customer as a basis for the introduction of lean manufacturing enterprise.

Master thesis is focused to design the timber pedestrian bridge over the track. The load-bearing construction is composed from the truss girder and cross laminated tiber plates. Bridge is coveder. Layout dimensions of the bridge are 49.0 m x 4.8 m

This thesis deals with the theoretical description of the infiltration process and field measurements of infiltration in the cadastral territory of Bohaté Málkovice. The research work carried out in 2011 in an experimental area on Haplic Chernozem/FAO, medium-heavy loam soil. The experimental area was divided into two parts, the topsoil layer on these surfaces was processed by both classic and minimization technologies. The plots were sown by spring barley. The applied measurements of water infiltration into the soil were two-cylinder method and MiniDisc. Within the vicinity of the infiltration experiments with intact soil were collected samples for laboratory determination of saturated hydraulic conductivity. From the field measurements and laboratory experiments were determined values of hydraulic conductivity (saturated and unsaturated), and other infiltration characteristics, the cumulative infiltration and infiltration rate. To evaluate the infiltration of the heats was used three-paramether Philp type equation that provides a good estimate of saturated hydraulic conductivity. For the evaluation of the MiniDisc there was used the Zangova method that provides the unsaturated hydraulic conductivity. The laboratory evaluation of the saturated hydraulic conductivity was compared with the estimated values obtained from the field measurements. The values of the saturated hydraulic conductivity from the laboratory measurements are closely comparable with estimates obtained from the steady infiltration rates from the field experiments. The research results also showed that medium-heavy loam soil, when being processed by minimization including modification of the soil surface by digging, have a positive effect on the infiltration of water into the soil. This fact leads to a higher protection plants in the vegetative period and improvement of the retention and storage capacity of soil.

Conjugated organic polymers have attracted immense interest for use in the active layer of photovoltaic cells, electroluminescent displays and diagnostic sensors. Precise control of the chemical structure of these conjugated materials is essential to achieve better device performance and certain structural aspects which have received minimal investigation include; the nature of the end groups, the precise control of the molecular weight and the formation of novel polymer topologies. Absolute control of these factors, in particular the end groups, has the potential to further tune the electro-optical properties, eliminate charge trapping and reactive sites, and facilitate block copolymer formation. The ring opening metathesis polymerisation of highly strained cyclophanediene monomers has proven to be an advantageous route to obtain soluble poly(p-phenylenevinylene)s (PPVs). In an extension of this previous work PPVs with both a pristine polymer backbone microstructure and a range of well-defined functional end groups have been prepared. These polymers exhibited excellent degrees of functionality, relatively narrow unimodal distributions and degrees of polymerisation much higher than those attainable by alternate routes. In particular the incorporation of an α-bromoester end group directly resulted in PPVs which were effective macroinitiators in the atom transfer radical polymerisation of methyl methacrylate. The diblock copolymers prepared by this route were isolated with narrow polydispersities, unimodal distributions and were free from homopolymer impurities. This method of preparing rod-b-coil diblock copolymers, where the properties of the two segments can readily be modified, provides access to materials which are of interest for both their self-assembly ability and for the development of a much required phase diagram in this area. Cyclic PPVs are of synthetic interest both for the absence of any end groups and for an infinitely long π-conjugated backbone, both of which are expected to contribute to unique electro-optical properties. The preparation of these target polymers was investigated by the ring expansion metathesis polymerisation of the cyclophanediene monomers. The formation of purely cyclic, low molecular weight PPVs was found to be highly dependent on both the reaction conditions used and the nature of the solubilising substituents. For example the preparation of purely cyclic PPVs with alkoxy side chains was unsuccessful, however the incorporation of alkyl side chains allowed for the successful isolation of the desired cyclic polymers.

Made available in DSpace on 2016-12-23T13:51:48Z (GMT). No. of bitstreams: 1 Rafael Bridi Corteletti.pdf: 1956935 bytes, checksum: 6892bb77244e2fe3eb75850c06a164a4 (MD5) Previous issue date: 2013-08-02
Front of gradual increase in areas planted paricá (Schizolobium amazonicum) and the growing interest of this species for plywood industry, biometric information about this species are scarce in the literature. This study was conducted with the objective of provide information dendrometric and growth for paricá in Paragominas region, Pará, through stem analysis complete. To attain the purpose, trees have been cut down thirties seven years old and these discs were obtained along the trunk, the positions of 0.1 m, 0.3 m, 0.7 m, 1.3 m and from this point of meter in meter, untill the first bifurcation. After collecting the discs, these were air dried and polished with a sequence of sandpaper for easy viewing of growth rings. With the polished surface of the discs were traced four rays perpendicular discs and with the assist of a magnifier rings were marked growth. After the delimitation of the rings, discs were scanned and the Image-Pro Express 6.0 was performed to measure the width of the rings from pith to bark. Discs in the height of 1.3 m above the ground, was made synchronization and microscopic characterization of annual growth rings. Logistic models were fitted volumetric, models taper, models form factor models average and diameter growth in structure prediction and projection. The models has been evaluated using measures the residual standard error precision absolute and percentage coefficient of determination, graphic residue analysis and statistics bias, mean absolute differences and standard deviation of the absolute differences. For the analysis of growth rings, can observe that this zone is demarcated fibrous. It was noted for the master series own paricá ring width favorable growth in the first two years. In commercial volumetric models showed that the model is Schumacher & Hall more accurate. In evaluating the taper functions in diameter model Demaerschalk was indicated that more precise results and height models Demaerschalk Ormerod showed similar results. The Logistic model stood out in terms of accuracy to estimate the average form factor. Finally, the model to describe the growth in diameter structure prediction was selected Exponential model to estimate the diameter in the form of Linear projection model was the most accurate
Diante do gradativo aumento de áreas plantadas de paricá (Schizolobium amazonicum) e o crescente interesse desta espécie para a indústria de compensados, informações biométricas a respeito dessa espécie ainda são escassas na literatura. Este trabalho foi conduzido com o objetivo de fornecer informações dendrométrica e de crescimento para o paricá, na região de Paragominas, Pará, por meio de análise de tronco completa. Para atender ao objetivo, foram abatidas trintas árvores de sete anos de idade e delas foram retirados discos ao longo do tronco, nas posições de 0,1 m; 0,3 m; 0,7 m; 1,3 m e a partir deste ponto de metro em metro, até a primeira bifurcação. Após a coleta dos discos, estes foram secos ao ar livre e polidos com uma sequencia de lixas para facilitar a visualização dos anéis de crescimento. Com a superfície polida dos discos foram traçados quatro raios perpendiculares por discos e com o auxilio de uma lupa foram demarcados os anéis de crescimento. Após a delimitação dos anéis, os discos foram escaneados e com o programa Image-Pro Express 6.0 foi realizada a medição da largura dos anéis no sentido medula-casca. Nos discos da altura de 1,3 m do solo, foi realizada a sincronização e a caracterização microscópica dos anéis de crescimento anuais. Foram ajustados modelos volumétricos, modelos de afilamentos, modelos de fator de forma comercial médio e modelos de crescimento em diâmetro na estrutura de predição e projeção. Os modelos foram avaliados por meio das medidas de precisão erro padrão residual absoluto e em percentagem, coeficiente de determinação, análise gráfica de resíduos e pelas estatísticas bias, média das diferenças absolutas e desvio padrão das diferenças absolutas. Pela análise dos anéis de crescimento, pode-se observar que este é demarcado por zona fibrosa. Notou-se pela série master que o paricá possui largura dos anéis de crescimento favoráveis nos dois primeiros anos. Nos modelos volumétricos comerciais verificou-se que o modelo de Schumacher & Hall foi o mais acurado. Na avaliação das funções de afilamento em diâmetro o modelo de Demaerschalk foi o que indicou resultados mais preciso e para altura os modelos de Demaerschalk e Ormerod indicaram resultados semelhantes. O modelo Logístico destacou-se em termos de precisão para estimar o fator de forma comercial médio. Finalmente, o modelo para descrever o crescimento em diâmetro na estrutura de predição foi selecionado o modelo Exponencial e para estimar o diâmetro na forma de projeção o modelo Linear foi o mais acurado

Made available in DSpace on 2015-04-14T13:37:48Z (GMT). No. of bitstreams: 1 413258.pdf: 7765401 bytes, checksum: f707e0d9b6cbc13bfb25ed8fdd4d3638 (MD5) Previous issue date: 2009-01-13
O presente estudo insere-se na ?rea tem?tica de Varia??o Ling??stica e tem por objetivo descrever e analisar o processo de eleva??o das vogais m?dias ?tonas /e/ e /o/, finais e n?o finais, no portugu?s falado em Rinc?o Vermelho - RS, comunidade que faz fronteira com a Argentina. A amostra para a realiza??o da pesquisa, constitu?da por catorze informantes, foi obtida a partir de entrevistas de experi?ncia pessoal e da aplica??o de um instrumento com perguntas diretas, destinado ? coleta de proparox?tonas. Os resultados da an?lise estat?stica revelaram que o al?amento das vogais m?dias /e/ e /o/ em posi??o final e n?o final ocorre variavelmente, sendo que o al?amento de /o/ ? mais freq?ente que o al?amento de /e/ em ambas as posi??es. Foram selecionadas como relevantes para o al?amento de /e/ em posi??o final as vari?veis Contexto Voc?lico da T?nica, Contexto Precedente, Tipo de S?laba, Contexto Seguinte, Localiza??o da Post?nica, Classe Gramatical, Sexo e Escolaridade. Para a vogal /o/, nessa mesma posi??o, mostraram-se relevantes as vari?veis Contexto Voc?lico da T?nica, Contexto Precedente, Tipo de S?laba, Contexto Seguinte, Localiza??o da Post?nica, Classe Gramatical, Sexo, Idade e Escolaridade. Entre os condicionadores ling??sticos e sociais, mostraram-se mais relevantes ao al?amento de ambas as vogais a vari?vel ling??stica Contexto Voc?lico da T?nica e a vari?vel social Escolaridade. No que refere-se ?s vogais em posi??o post?nica n?o final, foram selecionadas como relevantes as vari?veis Tipo de Post?nica, Contexto Precedente, Contexto Seguinte, Contexto Voc?lico da T?nica, Localiza??o da Post?nica, Tipo de Entrevista e Sexo. Os resultados indicam ainda que o al?amento em posi??o n?o final atinge mais a vogal m?dia /o/ do que a vogal m?dia /e/. H? ind?cios de que a varia??o das vogais nessa posi??o n?o ? regular e ocorre mais facilmente em determinados voc?bulos.

The Master´s thesis is focused on the design and structural analysis of the hall serving for businnes and exhibitons purposes that is strained by the permanent load, climatic and operational load. The construction is located in the area Opava. The hall is designed as intersection of two domes. The diametr of smaller one is 38,0 m and diametr of bigger one is 50,0 m. Maximum high of the construction reach 15,150 m. The main carrier elements of the structure are beams made from glued laminated timber, class GL24h.

This thesis discusses the Kaplansky zero divisor conjecture. The conjecture states that a group ring of a torsion-free group over a field has no nonzero zero divisors. There are situations for which this conjecture is known to hold, such as linearly orderable groups, unique product groups, solvable groups, and elementary amenable groups. This paper considers the possibility that the conjecture is false and there is some counterexample in existence. The approach to searching for such a counterexample discussed here is to first find a torsion-free group that has subsets A and B such that AB has no unique product. We do this by exhaustively searching for the subsets A and B with fixed small sizes. When |A| = 1 or 2 and |B| is arbitrary we know that AB contains a unique product, but when |A| is larger, not much was previously known. After an example is found we then verify that the sets are contained in a torsion-free group and further investigate whether the group ring yields a nonzero zero divisor. Together with Dr. Pace P. Nielsen, assistant math professor of Brigham Young University, we created code that was implemented in Magma, a computational algebra system, for the purpose of considering each size of A and B and running through each case. Along the way we check for the possibility of torsion elements and for other conditions that lead to contradictions, such as a decrease in the size of A or B. Our results are the following: If A and B are sets of the sizes below contained in a torsion-free group, then they must contain a unique product. |A| = 3 and |B| ≤ 16; |A| = 4 and |B| ≤ 12; |A| = 5 and |B| ≤ 9; |A| = 6 and |B| ≤ 7. We have continued to run cases of larger size and hope to increase the size of B for each size of A. Additionally, we found a torsion-free group containing sets A and B, both of size 8, where AB has no unique product. Though this group does not yield a counterexample for the Kaplansky zero divisor conjecture, it is the smallest explicit example of a non-uniqueproduct group in terms of the size of A and B.

The aim of this thesis is to design an exclusion of the road crossing the railway line no.300 with Kaštanová street in Brno. A ring road-based solution is proposed. Planned doubling of railway line, as mentioned in the feasibility study of SJKD, was taken into account. The new railway station Brněnské Ivanovice is designed, which will together with public transport bus services create an interchange station. The project also includes a newly designed routes for pedestrians.

L'objectif principal de la thèse porte sur la synthèse contrôlée et la caractérisation d’architectures macromoléculaires complexes originales à base de POE. Les POEs α-undécènyle-ω-hydroxy sont obtenus par polymérisation anionique par ouverture de cycle de l’oxyde d’éthylène. Le groupement hydroxyle est modifié pour accéder à des POEs α-undécènyle-ω-méthacrylate et des POEs α-undécènyle-ω-acétylène. Ces premiers POEs sont ensuite utilisés pour préparer soit des POEs à structure en peigne par ATRP dans l'eau soit par l'intermédiaire de réaction « click », des POEs à structure en étoile tétrafonctionnelles, tandis qu’avec les seconds permettent d’obtenir des PI-b-POE par réaction « click » avec le polyisoprène ω-azoture. Les extrémités de chaîne de POE commerciaux α-méthoxy-ω-hydroxy sont modifiées en POEs α-méthoxy-ω-allyle ou en POEs α-méthoxy-ω-undécènyle pour synthétiser par réaction d’hydrosilylation des étoiles de POE à structures en étoile octafonctionnelles
The main objective of the thesis focuses on the controlled synthesis and the characterization of original and complex macromolecular architectures based on PEO. α-Undecenyl-ω-hydroxy PEOs are obtained by anionic ring opening polymerization of ethylene oxide. The hydroxyl group is modified to access to α-undecenyl-ω-methacrylate PEOs and α-undecenyl-ω-acetylene PEOs. These first PEOs are used to prepare either comb-shaped PEOs by ATRP in water or through by click reaction of tetrafunctional star-shaped PEOs. Whereas the second PEOs allow obtaining block copolymers PI-b-PEO via click reaction with ω-azide polyisoprene. The chain-ends of commercial α-methoxy-ω-hydroxy PEO are modified in α-methoxy-ω-allyl PEOs or in α-methoxy-ω-undecenyl PEOs to synthesize by hydrosilylation reaction octafunctional star-shaped PEOs

"Sem resumo feito pelo autor"; A bioquímica do desenvolvimento animal constitui uma área científica muito lata e complexa (Rothestein, 1986, Jazwinski, 1996, McClearn, 1997). Grande parte dos conceitos que vão ser abordados neste capítulo nem sempre estão explícitos na literatura o que torna necessário fazer-se uma breve sistematização. Os sistemas vivos distinguem-se dos sistemas inanimados pela forma como contrariam a segunda lei da termodinâmica que não prevê a existência de processos cíclicos na natureza (Blum, 1955, Calow, 1978) e preconiza uma tendência contínua e unidirecional da ordem para a desordem. A universalidade da tendência entrópica só é válida para sistemas isolados que não trocam matéria e ou energia através das fronteiras que os delimitam. No entanto, o universo, é em regra, considerado como um sistema aberto e os processos naturais como ciclos que envolvem um fluxo entre a ordem e a desordem, a composição e a decomposição (Calow, 1978). Apesar disso, algumas configurações mantêm a sua existência por consideráveis períodos de tempo, graças à sua estabilidade ou à sua repetibilidade. O aparecimento repetitivo de uma unidade individual pode acontecer devido a substituição fortuita, quando a mesma configuração reaparece com elevada frequência, por possuir probabilidade elevada de formação, ou devido a replicação, quando providencia uma cópia de si própria conservando a sua organização complexa, mesmo que a entidade original seja posteriormente destruída. Uma vez que a replicação permite a formação de um número elevado de cópias, uma unidade com essa capacidade pode tornar-se vulgar mesmo quando a sua probabilidade de formação é baixa. Este tipo de ocorrência manifesta-se na formação de cristais e na reprodução dos organismos vivos (Calow, 1978, Jazwinski, 1996). Um sistema só pode perpetuar-se por replicação directa se for estável e inerte. Caso contrário, a replicação obedece forçosamente a um plano, como acontece com os organismos vivos que se replicam de acordo com as regras codificantes do seu material hereditário (Caihrms-Smith, 1971, Rothestein, 1986, Lewin, 1994, Jazwinski, 1996). A evolução dos seres vivos enquanto sistemas individualizados apresenta três aspectos importantes, como sejam: o aumento progressivo de tamanho, a diferenciação celular e o desenvolvimento de sistemas de comunicação entre os seus componentes (Zeuthen, 1947, Calow, 1978, Chauvet, 1986). Os ciclos da vida, para além de oscilarem entre duas fases distintas de formação e decomposição, exigem um terceiro passo fundamental que é o da replicação. O diagrama da figura 1.1 representa os principais eventos do ciclo de vida animal (Calow, 1978, Hosokawa et al., 1997).

Made available in DSpace on 2014-12-17T14:52:43Z (GMT). No. of bitstreams: 1 AnaCGS.pdf: 4192359 bytes, checksum: 28eb36354363672f88a28074f9df8b42 (MD5) Previous issue date: 2008-12-23
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Telecommunications play a key role in contemporary society. However, as new technologies are put into the market, it also grows the demanding for new products and services that depend on the offered infrastructure, making the problems of planning telecommunications networks, despite the advances in technology, increasingly larger and complex. However, many of these problems can be formulated as models of combinatorial optimization, and the use of heuristic algorithms can help solving these issues in the planning phase. In this project it was developed two pure metaheuristic implementations Genetic algorithm (GA) and Memetic Algorithm (MA) plus a third hybrid implementation Memetic Algorithm with Vocabulary Building (MA+VB) for a problem in telecommunications that is known in the literature as Problem SONET Ring Assignment Problem or SRAP. The SRAP arises during the planning stage of the physical network and it consists in the selection of connections between a number of locations (customers) in order to meet a series of restrictions on the lowest possible cost. This problem is NP-hard, so efficient exact algorithms (in polynomial complexity ) are not known and may, indeed, even exist
As telecomunica??es desempenham um papel fundamental na sociedade contempor?nea. Mas ? medida que novas tecnologias s?o introduzidas ao mercado, cresce tamb?m a demanda por novos produtos e servi?os que dependem da infra-estrutura oferecida, tornando os problemas de planejamento de redes de telecomunica??es, apesar da evolu??o tecnol?gica, cada vez maiores e complexos. No entanto, muitos desses problemas podem ser formulados como modelos de otimiza??o combinat?ria, e o uso de algoritmos heur?sticos podem ajudar a solucionar essas quest?es da fase de planejamento. Neste trabalho, foram desenvolvidas duas implementa??es metaheur?sticas puras Algoritmo Gen?tico (AG) e Algoritmo Mem?tico (AM) al?m de uma terceira implementa??o h?brida Algoritmo Mem?tico com Vocabulary Building (AM+VB) para um problema de telecomunica??es que ? conhecido na literatura por Problema de Atribui??o de Localidades a An?is SONET ou SRAP (do ingl?s, SONET Ring Assignment Problem). O SRAP surge durante a etapa do planejamento f?sico da rede e consiste na determina??o das conex?es entre um conjunto de localidades (clientes), de modo a satisfazer uma s?rie de restri??es ao menor custo poss?vel. Esse problema ? NP-dif?cil e portanto algoritmos exatos eficientes (de complexidade polinomial) n?o s?o conhecidos, podendo, inclusive, nem existir

La sequence de l'arn-2 de l'isolat s comporte une seule phase de lecture ouverte qui correspond a une proteine de p. M. 150 k. La proteine de la coque est localisee dans la region c terminale de la proteine 150 k. Une proteine "de diffusion" se situerait en amont de la proteine de la capside. Les sequences des arn satellites issus d'isolats appartenant aux serotypes s (s et l) et g (g, e et c) comportent toutes une seule phase de lecture ouverte correspondant a une proteine de 48 k. La comparaison des sequences permet de distinguer 2 groupes: les arn s et l d'une part, les arn g, e et c, d'autre part. A l'interieur de chaque groupe, les arn presentent plus de 90% d'homologie de sequence tandis que 63% des nucleotides sont communs aux 5 arn etudies

Neste trabalho, temos o objetivo de introduzir o Problema de Noether Clássico e sua versão não- comutativa introduzida por J. Alev e F. Dumas em [AD06]. Discutiremos os principais casos co- nhecidos nos quais os problemas têm solução positiva, observando um forte paralelo entre os casos comutativo e não-comutativo. Cobriremos os tópicos preliminares necessários para entendimento dos enunciados: álgebras de Weyl, anéis de operadores diferenciais, extensões de Ore, localização em domínios não-comutativos, e corpos de Weyl. No Capítulo 5 deste trabalho, o aluno apresenta duas contribuições originais, obtidas em colaboração com seu orientador V. Futorny e F. Eshmatov: o Teorema 5.5, que é um resultado folclórico sobre invariantes de ações livres de grupos finitos no anel de operadores diferenciais de variedades afins; e o Teorema 5.6, que até onde sabemos é iné- dito, sobre invariantes dos Corpos de Weyl sob a ação de grupos de pseudo-reflexão. Todo material algébrico preliminar para a demonstração destes dois teoremas é incluído no texto da dissertação: um básico de teoria de invariantes, vários resultados da teoria de grupos de pseudo-reflexão, alguns conceitos básicos de geometria algébrica e álgebra comutativa, e uma discussão detalhada do quo- ciente de variedades afins sob ação de grupos finitos.
In this work we aim to introduce the Classical Noether´s Problem, and its noncommutative version introduced by J. Alev and F. Dumas in [AD06]. We discuss the most well known cases of positive solution of these problems, pointing out a strong similarity between the cases of positive solution for the classical and noncommutative versions of the Problem. We cover the preliminary topics to understand the statement and solutions of these problems: Weyl algebras, differential operators rings, Ore extensions, noncommutative localization, and Weyl Skew-Fields. In the Chapter 5 of this dissertation, the student shows two original contributions, obtained in collaboration with his advisor V. Futorny and F. Eshmatov: Theorem 5.5, a result belonging to the folklore of the area of differential operators, describing its invariants under the free action of a finite group on an affine variety; and Theorem 5.6, about the invariants of the Weyl skew-fields under the action of pseudo-reflection groups. As far as we know, this result is new. All preliminary algebraic facts to prove these two facts are included in the body of this text. It includes some basic facts on invariant theory, many results about pseudo-reflection groups, some basic concepts of algebraic geometry and commutative algebra, and a detailed discussion of the quotient of an affine variety under the action of a finite group.

L'objectif de ce travail de thèse a été de caractériser et de modéliser le comportement de diodes laser à cavité verticale émettant par la surface (VCSELs) à 1,3µm et 1,55µm. Ces sources laser constituent en effet un enjeu majeur dans les transmissions d'information à haut débit. La modélisation est basée sur l'analogie entre les équations d'évolution monomodes linéarisées et les équations de Kirchhoff du circuit électrique équivalent de la cavité optique. Il est donc possible d'exprimer chaque élément de ce circuit en fonction des paramètres intrinsèques du VCSEL. Cependant, bien que les VCSELs utilisés soient en puce, le modèle électrique complet doit prendre en compte des effets parasites liés à l'accès électrique. Une méthode originale, basée sur la mesure du «Turn-On Delay» et des paramètres S, a donc été développée afin de pouvoir s'affranchir de ces effets parasites et ainsi d'obtenir la valeur de chaque élément du circuit sans procédure d'optimisation. Grâce à cette méthode, il est alors possible d'extraire les paramètres intrinsèques du VCSEL. Le modèle est ensuite confronté aux résultats de simulation des équations d'évolution linéarisées en fonction des paramètres extraits. Le comportement en bruit des VCSELs est également analysé afin de compléter le circuit électrique par des sources équivalentes de bruit en tension et en courant. Cela permet d'élaborer un schéma électrique équivalent complet valide expérimentalement. Enfin la mesure du spectre des VCSELs permet d'en déduire l'évolution de la largeur de raie en fonction du courant de polarisation et d'en extraire le facteur de Henry, source de dégradation des télécommunications optiques.

The purpose of this master’s thesis is foremost to provide a simple guide how to build elements of optical metropolitan area network. The basic model consists to sequence of construction, network topology, passive and active parts. The collection contains examples of alternative technology such as Wireless LAN with different frequency. The optical network construction based on optical cable, fibres, splices, trays, adapters, connectors and active parts for example a lot of media convertor models. After that there are demonstrating type of wavelength division multiplexer used in metropolitan area network – passive planar PCL splitter. One of the passive planar splitter are used to increase optical fibre channel. At the end of the collection a simplified examples of used measurements – optical time domain reflectometry and optical fibre transmission. Contains standard protocols or reflectogram. The conclusion of this thesis summarizes costs of FTTb (Fibre To The Building) model of optical metropolitan area network in Czech republic and future contribution for society.

Song Junliang = 帶有環交換作用的自旋1/2梯子模型中的量子纠缠 / 宋均亮.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.
Includes bibliographical references (leaves 60-67).
Text in English; abstracts in English and Chinese.
Song Junliang = Dai you huan jiao huan zuo yong de zi xuan 1/2 ti zi mo xing zhong de liang zi jiu chan / Song Junliang.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- What is Entanglement --- p.1
Chapter 1.2 --- Quantum Information and Entanglement --- p.4
Chapter 1.3 --- Entanglement in Condensed Matter Physics --- p.6
Chapter 1.4 --- The S = 1/2 Spin Ladder with Ring Exchange --- p.9
Chapter 1.5 --- Arrangement of the Thesis Writing --- p.11
Chapter 2 --- Measures of Entanglement --- p.13
Chapter 2.1 --- Axiomatic Approach --- p.14
Chapter 2.2 --- Entropy of entanglement in pure states --- p.16
Chapter 2.3 --- Concurrence --- p.17
Chapter 2.4 --- Negativity --- p.19
Chapter 2.5 --- Other measurements --- p.20
Chapter 3 --- Entanglement in S=l/2 Ladder with Ring Exchange at T=0 --- p.22
Chapter 3.1 --- Model Hamiltonian and Phase Diagram --- p.22
Chapter 3.2 --- Ground-state concurrence --- p.24
Chapter 3.3 --- Two-site entanglement of the rung and the SU(4) point --- p.29
Chapter 3.4 --- Scaling behavior of the block-block entanglement --- p.34
Chapter 3.5 --- Entanglement of the Ferromagnetic state --- p.37
Chapter 3.6 --- Other Measurements --- p.42
Chapter 3.7 --- Summary and Discussion --- p.43
Chapter 4 --- Thermal Entanglement --- p.45
Chapter 4.1 --- A Four-Spin Plaquette --- p.46
Chapter 4.2 --- Thermal concurrence --- p.50
Chapter 4.3 --- Magnetic susceptibility as Entanglement Witness --- p.52
Chapter 4.4 --- Numerical results in a 6 x 2 ladder --- p.54
Chapter 4.5 --- Summary and Discussion --- p.55
Chapter 5 --- Conclusion and future work --- p.58
Bibliography --- p.60

碩士
國立清華大學
化學工程學系
104
In this work, a series of the novel poly(arlyenevinylene)s has been prepared by ring-opening metathesis polymerization (ROMP) of strained cyclic vinylene monomers composed of conjugated units such as cyclopentadithiophene (CPDT), bis(thienyl)-benzothiadiazole (DTBT), and bis(hexyl)-bithiophene (BTh), which were initiated by ruthenium-based catalysts. The monomers were synthesized by McMurry coupling using TiCl4/Zn and the products were characterized by 1H and 13C NMR spectroscopy and fast atom bombardment (FAB) mass spectrometry. In ROMP, molecular weight of the polymers can be varied by changing the monomer to catalyst ratio. Furthermore, the resulting polymers have less structural defects. Diblock copolymers of poly(arylenevinylene)s were also synthesized by similar procedure, in which first-block was synthesized by ROMP of DTBT monomer, followed by subsequent addition of the second and third monomers of CPDT and BTh. The block copolymers exhibit multiple functions derived from each block, e.g. wider-range UV-vis absorption and higher and lower HOMO-LUMO levels than those of homopolymers. In addition, morphology of homopolymers and block copolymers were studied by atomic force microscopy (AFM) to observe microphase separation in their film state. These type of polymers are potentially useful as efficient light-harvesting materials in OPV devices.