Dissertations / Theses: 'Complex conversion'

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Popli, Nipun. "Multi-layered Energy Conversion and Frequency Control in Complex Electric Power Systems." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/916.

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The main performance objective in an electric power grid entails timely and efficient generation and delivery to the time-varying electricity demand. As the electricity industry is witnessing proliferation of the mainstream renewables, the minute-by-minute variations in wind and solar power generation may result in temporary electricity scarcity that jeopardizes grid stability and quality of service. The evolving electricity markets are aimed at incentivizing the conventional generators to reinforce their operating flexibility. This dissertation concerns the goal of enhancing the dynamic response rates of interconnected controllable resources by means of a multi-layered fuel input control of electrically coupled heterogeneous energy conversion components. Both power engineering and large-scale control contributions are made in support of this enhancement. First, improved fuel input controls are designed to enable flexible physics-based energy conversion dynamics required by the interconnected grid. To efficiently utilize the resources load-following and regulation problems are stated. The efficacy of proposed fuel input control designs in enhancing the dynamic response rates is illustrated on IEEE 14-bus system. Second, the problem is formalized as multi-input multioutput time-varying trajectory tracking based on a decentralized spatiotemporal composite control design. The concepts of vector-Lyapunov function and singular perturbation are invoked to formalize model decompositions, over space and time, respectively. Next, the assumptions for model simplifications are relaxed and the problem of parametric uncertainty is addressed. A minimumcost resilient co-design approach is introduced for storage-sensors-communication channels in a complex electric power grid. The notion of selective strong structural fixed modes is explored as a characterization of feasible decentralized control laws for an arbitrary system realization satisfying a pre-specified structure. Finally, it is proposed that planning of generation portfolio must be driven by the objective of maintaining adequate operating flexibility in the system. The goal is to ensure sufficient ramp capacity to sustain the significant integration of intermittent renewable resources.

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Ebadi, Zahra sadat. "Application of complex quantized feedback in direct conversion receivers for wireless applications." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31292.

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The recent resurgence in radio frequency (RF) transceiver design for wireless applications is accompanied by aggressive design goals such as low cost, low power dissipation; small form factor, and high-speed data transfer. To address these objectives, extensive research has been focused on the development of monolithic transceiver architectures, especially using low-cost CMOS technology. It is in this context that there is renewed interest in the direct-conversion receiver (DCR) architecture, the subject of this research. Currently, the use of DCRs involves a number of challenges. Issues of DC offset, flicker noise, LO leakage and radiation, I/Q mismatch, and intermodulation distortion should be carefully considered and addressed in a DCR design. Also, because of cost incentives and performance, one of the main trends in the evolution of wireless receivers is to implement more and more functionality by way of digital signal processing (DSP). The main objective of this thesis is the development and implementation of solutions to overcome these impairments in the DCR architecture and facilitate DCR design using DSP. To achieve this goal, we begin by using AC coupling to remove DC offset and to reduce flicker noise. Then, quantized feedback (QFB) is employed in both I and Q channels to reduce the baseline wander effect caused by AC-coupling. Such modifications are unable to combat carrier phase error and I/Q mismatch problems. However, they can be effectively reduced using a cross-coupled or complex QFB (CQFB), the key contribution in the thesis. The performance of this CQFB-enhanced DCR architecture is theoretically analyzed and experimentally validated. Next, the design issues for adaptive implementation of CQFB using DSP techniques are addressed. Further, its use is illustrated in the context of a direct-conversion orthogonal frequency-division multiplexing (OFDM) receiver. We show that digital CQFB is very effective in compensation of DC offset, I/Q mismatch, and carrier phase error in a DCR for OFDM signaling. To assist in validation of the developed approach, a prototype RF front-end of the receiver is designed and fabricated in TSMC 0.18μm CMOS process for 2.4GHz wireless applications. The developed prototype provides for user control of I/Q mismatch and includes all the main blocks of the RF front-end of the receiver, namely, a low-noise amplifier (LNA), two mixers and a voltage-controlled oscillator (VCO). This prototype can be used as test vehicle for evaluation of various I/Q mismatch compensation methods implemented in the back-end.
Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate

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Nyamhingura, Amon. "Characterization and chemical speciation modelling of saline effluents at Sasol Synthetic Fuels Complex-Secunda and Tukuta power station." Thesis, University of the Western Cape, 2009. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_7974_1297940655.

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The study shows conclusively that brine composition and concentration is highly variable at these South African power utilities and processes such as RO, contact with ash and CO2 ingress can have an impact upon the overall brine quality. Aq.QA was found to be a more accurate tool for classifying waters according to dominant ions than Stiff diagrams but Stiff diagrams still have the superior advantage of being a mapping tool to easily identify samples of similar composition as well as quickly identify what has been added or what has been removed from a water stream. Chemical speciation could identify effluent streams where CO2 dissolution had taken place.

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Mouri, Shinichiro. "Dynamical properties of photo-induced spin conversion in the spin crossover complex with multi-stability." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/124406.

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Martinsohn, Jann Thorsten. "Molecular evolution of the mouse major histocompatibility complex the detection of low frequency gene conversion events /." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963058975.

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Lorenzi, Roberto. "Studies on gene conversion as a mutational mechanism in the evolution of major histocompatibility complex genes." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336766.

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Grosu, Yaroslav G. "Thermodynamics and operational properties of nanoporous heterogeneous lyophobic systems for mechanical and thermal energy storage/dissipation." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22579/document.

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La thèse est consacrée à l’étude théorique et expérimentale des propriétés thermodynamiques et d'usage de Systèmes Hétérogènes de Lyophobes nanoporeux (SHL) et leurs dépendances en fonction de la température afin de déterminer les conditions optimales et accroître l'efficacité des dispositifs énergétiques à base de SHL. La thèse présente les résultats obtenus dans trois directions principales de recherche: 1. Analyse thermodynamique; 2. Caractéristiques des SHL dans une large plage de température; 3. Stabilité de SHL dans différentes conditions opérationnelles. La gamme maximale de température étudiée est à 2 - 150 °C et 0.1 - 120 MPa pour la pression. En particulier, les résultats comprennent une équation d'état pour décrire des SHL réels qui prend en compte la distribution de taille des pores; les caractéristiques énergétiques de quatre (deux mésoporeux et deux microporeux) SHLs mesurées dans une large plage de température; certains nouveaux régimes de fonctionnement de SHLs ont été étudiés dans des conditions isobares contrôlées; enfin le concept d'utilisation de SHL comme système avec dilatation thermique négative prononcée est proposé
The thesis is devoted to the theoretical and experimental investigations of thermodynamic and operational properties of nanoporous Heterogeneous Lyophobic Systems (HLS) and their temperature dependences in order to determine optimal conditions and increase efficiency of HLS-based energetical devices. The thesis reflects results obtained in three main directions of research: 1. Thermodynamic analysis; 2. Characteristics of HLS in a wide temperature range; 3. Stability of HLS under different operational conditions. Maximum temperature range investigated is to 2 - 150 ° C. Pressure range is 0.1 - 120 MPa. Particularly, results include proposed equation of state for real HLS, which takes into account pore size distribution function; the energetic characteristics of four (two mesoporous and two microporous) HLSs collected in a wide temperature range; some new operation regimes of HLSs were investigated under controlled isobaric conditions; proposed concept of usage of HLS as a system with pronounced negative thermal expansion

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Liu, Li. "Propriétés photo-physiques de nouveaux matériaux moléculaires pour la conversion de photons en énergie." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE010/document.

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Plusieurs processus photo-induits d'énergie et de transfert d'énergie ont été étudiés en solution et dans le film par spectroscopie d'absorption transitoire et de fluorescence pour deux types de cellules solaires. Combinés avec d'autres expériences et par une analyse globale, ces phénomènes ultrarapides avec leur durée de vie ont été observés et les scénarios photo-induits ont été déterminés. La compréhension approfondie des matériaux moléculaires pourrait aider les chimistes à concevoir des cellules solaires efficaces. La première étude sur l'influence des conceptions chimiques sur la formation et la séparation des charges implique différentes fractions donneuses et différents solvants et les résultats ont été expliqués par la théorie de Marcus-Jortner combinée avec le calcul quantique. La deuxième étude porte sur les complexes Fe (II) comme photosensibilisateurs pour les cellules solaires sensibilisées aux colorants. On a étudié une série de complexes de Fe (II) homo et hétérotéptiques avec des ligands de carbène et de terpyridine en solution et dans le film. La durée de vie de l'état de transfert de la charge métal-ligand du triplet d'enregistrement du complexe Fe (II) est obtenue en solution. La compréhension du film est en cours
Various photo-induced energy and energy transfer processes were investigated in solution and in the film by transient absorption and fluorescence spectroscopies for two types of solar cells. Combined with other experiments and through a global analysis, those ultrafast phenomena with their lifetimes were observed and the photo-induced scenarios were determined. The insight understanding of molecular materials could help chemists to design efficient solar cells.The first study about the influence of chemical designs on charge formation and separation involves different donor moieties and different solvents and the results were explained by Marcus-Jortner theory combined with quantum calculationThe second investigation is about Fe(II) complexes as photosensitizers for dye-sensitized solar cells. A series of homo- and heteroleptic Fe(II) complexes with carbene and terpyridine ligands have been studied in solution and in the film. The record triplet metal-to-ligand charge transfer state lifetime of Fe(II) complex is achieved in solution. The further understanding in the film is in progress

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Rogers, Claire. "Depth conversion methods for the Torsk Oilfield : investigating the complex velocity field of the Seaspray Group, Gippsland Basin /." Title page, abstract and table of contents only, 2003. http://web4.library.adelaide.edu.au/theses/09SB/09sbr7421.pdf.

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Bažík, Lenka. "Zámecký areál Břeclav." Master's thesis, Vysoké učení technické v Brně. Fakulta architektury, 2016. http://www.nusl.cz/ntk/nusl-240865.

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It is important to consider broader context to create a concept for a chateau complex in Breclav - within the region and mainly engaging in Lednice-Valtice Cultural Landscape (LVA). Buildings of LVA are a heritage of Lichtenstein as well as the chateau complex in Breclav. Breclav is also referred to as the gateway to the Lednice-Valtice area. Lednice-Valtice area has been from its beginning a place for recreation and entertainment and that is the concept of what it should be nowadays. Partly the buildings of LVA are used for various cultural events - concerts (Lednice), educational programs (Pohansko) and exhibitions (Valtice). However there are mostly only tours of the interiors and only seasonally. To fulfil the potential of the area it would be appropriate to join all of the buildings in one program that will support the current events and complement with other functions. I propose to use the chateau complex in Breclav as a cultural and recreational centre with outreach to the LVA. Breclav would complete the triangle with other centres in Lednice and Valtice.

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LI, WEIXIN. "A HYBRID DEVICE APPROACH TO HIGH PERFORMANCE IN ORGANIC LIGHT-EMITTING DIODES." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1148051195.

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Chambron, Jean-Claude. "Synthese et etude de complexes du cuivre (i) et du ruthenium (ii) en vue de la separation intramoleculaire des charges photoinduites." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13092.

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Preparation de 2 macrocycles contenant a la fois des sites chelatants diphenyl-2,9 phenanthroline-1,10 et dialkyl-4,4' ou diaryl-4,4' bipyridine-2,2'. Dans le complexe heterodinucleaire il existe une interaction a l'etat excite entre les 2 metaux

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Fadhila, Audinisa. "Integrating novel circular economy technologies in complex trans-sector value chains : Case study of insect larvae conversion technology within waste and feed value chains." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284339.

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Even as the current linear value chains (LVC) of organic waste and animal feed hold the potential to become circular, these practices continue to pose major environmental risks such as deforestation and overfishing. Therefore, a novel circular value chain (CVC) is proposed, connecting the organic waste stream with animal feed production by the use of insect-based organic waste conversion technology. The Black Soldier Fly (BSF) is chosen as the insect-based conversion technology since it has nutritional properties, which serves both waste treatment and animal feed material production purposes. Although there are already initiatives and collaborations in the Swedish context, the transition has not yet been successful. The study aims to identify and propose required solutions for the value chain transition. By using the transitional study tools of Technological Innovation System (TIS) and Multi Level Perspective (MLP) alongside sustainable value chain transition studies, it is found that technological and information-related adjustments are required to further enable the transition. Technological adjustments are studied from the perspective of Ragn-Sells AB as a potential insect- based organic waste conversion actor. Scenarios to see economical sustainability were designed based on the quantity fluctuation of waste as material input (3,000 tons per year and 15,000 tons per year), possibility of automated operation which affects both investment and operating costs of the facility, and procurement of small BSF larvae (off-site and in-site breeding). From the different scenarios designed, it is found that the scenario with the capacity of 15,000 tons per year, higher investment due to automation, and on-site breeding is the most preferable for the case. To answer information- related needs, an Informational Flow Framework (IFF) is proposed. The IFF consists of “Value Chain Stakeholders”, “CVC Relevant Regulations”, “Information Data Pool”, and “Information Flow”. The framework’s main function is to identify the type of material information required to be distributed in the system and the stakeholders whom require and/or provide various information, with the main goal of increasing the trust among the stakeholders related to material information.
Trots att den nuvarande linjära värdekedjan (Linear Value Chain) för organiskt avfall och djurfoder har potentialen för en cirkulär ekonomi, så utgör den nuvarande praxisen fortfarande stora risker såsom avskogning samt överfiske. Därför föreslås en ny cirkulär värdekedja (Circular Value Chain), som förbinder den organiska avfallsströmmen med djurfoderproduktion med användning av insektbaserad omvandlingsteknologi för organiskt avfall. Svart soldat fluga (Black Soldier Fly/BSF) utses som den insektsbaserade omvandlingsteknologin eftersom den har näringsegenskaper som bistår både avfallsbehandling och djurfoderproduktionsändamål. Trots att det redan finns initiativ och samarbeten i det svenska sammanhanget har övergången ännu inte lyckats. Studien syftar till att identifiera och föreslå nödvändiga lösningar för den cirkuläravärdekedjan. Genom att använda övergångsstudieverktygen av Teknologiskt Innovations System (TIS) samt Multi Level Perspective (MLP) och diverse värdekedjeövergångsstudier, konstateras det att tekniska och informationsrelaterade justeringarkrävs för att ytterligare möjliggöra övergången från en linjär till en cirkulär värdekedja. Teknologiska anpassningar studeras ur Ragn-Sells ABs perspektiv som en potentiell aktör för omvandling av organiskt avfall. Scenarier för att undersöka ekonomisk hållbarhet utformades baserat påfluktuering av mängden avfall som materialinmatning (3,000 ton per år och 15, 000 ton per år), möjlighet till automatiserad drift som påverkar både CAPEX & OPEX i anläggningen (hög CAPEX och låg CAPEX), och upphandling av små BSF-larver (avel utanför anläggningen). Från de olika utformade scenarierna konstaterades att scenariot med en kapacitet på 15,000 ton per år, hög CAPEX och avel på plats är det mest fördelaktiga för Ragn Sells AB. För att besvara informationsrelaterad justering föreslås en informationsflödesram (IFF). IFF består av ”Value Chain Interessholders”, “CVC Relevant Regulations”, “Information Data Pool” och “Information Flow”. Ramens huvudfunktion är att identifiera vilken typ av materialinformation som krävs för att distribueras i systemet och den aktör som kräver och/eller tillhandahåller informationen, med det huvudsakliga målet att öka förtroendet bland aktörerna relaterade till materiell information.

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Björklund, Daniel. "Implementation of a Software-Defined Radio Transceiver on High-Speed Digitizer/Generator SDR14." Thesis, Linköpings universitet, Elektroniksystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-78213.

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This thesis describes the specification, design and implementation of a software-defined radio system on a two-channel 14-bit digitizer/generator. The multi-stage interpolations and decimations which are required to operate two analog-to-digital converters at 800 megasamples per second (MSps) and two digital-to-analog converters at 1600 MSps from a 25 MSps software-side interface, were designed and implemented. Quadrature processing was used throughout the system, and a combination of fine-tunable low-rate mixers and coarse high-rate mixers were implemented to allow frequency translation across the entire first Nyquist band of the converters. Various reconstruction filter designs for the transmitter side were investigated and a cheap implementation was done through the use of programmable base-band filters and polynomial approximation.

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ESTEBAN, NYDIA MARGARITA HABRAN. "VISIBLE LIGHT SENSITIVE MESOPOROUS NANOHYBRID, PREPARED FROM LEPIDOCROCITE-LIKE FERRITITANATE COUPLED TO A CHARGE TRANSFER COMPLEX AND ITS APPLICATION IN PHOTOCATALYTIC CONVERSION OF A POLLUTANT GAS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33940@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O foco do presente estudo é desenvolvimento de uma heteroestrutura de dois semicondutores com capacidade de reduzir a taxa de recombinação elétron/buraco mediante uma intensa separação de carga, e ao mesmo tempo sendo sensível ao espectro de luz visível. A separação de carga estaria sendo alcançada por meio da injeção de elétrons livres dentro da banda de condução (BC) do TiO2 na forma de anatásio, provenientes do orbital molecular mais alto ocupado (HOMO) da acetilacetona (Acac), ligada às partículas de anatásio, seguida da sua injeção dentro dos orbitais d desocupados do Fe3+ localizados dentro da banda de energia proibida das nanofolhas de ferrititanatos. Ao mesmo tempo a absorção da luz visível poderia ser assegurada através das nanofolhas de ferrititanatos, considerando-se a interação dos níveis energéticos do Fe3+ com a luz e as bandas de valência e condução, bem como pela formação de complexo de transferência de carga (CTC), entre as nanopartículas de anatásio e Acac. Os nanohíbridos mesoporosos (as heteroestruturas) são produzidos pelas diferentes rotas de junção de nanofolhas de ferrititanato, obtidas da areia mineral ilmenítica e posteriormente esfoliadas, com nanopartículas de TiO2 modificadas com acetilacetona, estes útlimos formando CTC. As técnicas de caraterização empregadas tais como adsorção-dessorção de N2, espectroscopia de emissão de fotoluminescência (PL) e espectroscopia de refletância difusa (DRS), entre outras, confirmaram a formação das heteroestruturas mesoporosas sensíveis à luz visível e com forte mecanismo de separação de cargas. A fotodegradação do gás poluente NO no espectro de luz-visível por meio de vários nanohíbridos mesoporosos (fotocatalisadores) mostrou-se bem sucedida, exibindo uma eficiência até 7 vezes superior em comparação à atividade do material fotocatalítico padrão TiO2 (P-25 da Degussa).
This work focues on the development of a heterostructure composed by two semiconductors, capable to decrease the electron/hole recombination rate through a robust charge separation, and at the same time, this nanohybrid is sensitive to visible light spectrum. The charge separation is achieved by the injection of free electrons within the conduction band (BC) of TiO2 in anatase form, which come from the highest-occupied-molecular-orbital (HOMO) of acetylacetone (Acac), linked to the anatase nanoparticles, followed by the injection into unoccupied Fe3+ d-orbital within band-gap energy of the ferrititanate nanosheets. Additionally, the absorption of visible light could be assured by ferrititanate nanosheets, considering the interaction of the energy levels of Fe3+ with visible light and the valence and conduction bands, as well as, the formation of the charge transfer complex (CTC), between the anatase nanoparticles and Acac. The mesoporous nanohybrids (called also as heterostructures) were produced by different routes of junction of two components: i) ferrititanate nanosheets, which were synthesized from ilmenite mineral sands, and then they were exfoliated into single layers and ii) TiO2 nanoparticles, modified with Acac, which formed the CTC. The characterization techniques, such as N2 adsorption-desorption, photoluminescence emission spectroscopy (PL) and diffuse reflectance spectroscopy (DRS), and so on, confirmed the formation of the mesoporous heterostructures sensitive to visible light and with a robust mechanism of charge separation. The photodegradation of NO pollutant gas within the visible light spectrum through several mesoporous nanohybrids (photocatalysts) demonstrated being well succeeded, exhibiting an efficiency more than seven times higher than the activity benchmark TiO2 (Degussa P-25) photocatalyst.

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Martínez, Arias Rosa. "Variación haploide en secuencias nucleares humanas: el pseudogén GBA." Doctoral thesis, Universitat Pompeu Fabra, 2001. http://hdl.handle.net/10803/7069.

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Hemos analizado la variabilidad genética de una zona no codificante autosómica, el pseudogén homólogo al gen de la glucocerebrosidasa (psGBA).
Parte del análisis se ha realizado desde la perspectiva de la genética de poblaciones humanas.
Desde un punto de vista más genómico hemos establecido la dinámica de la región, a fin de entender las causas del espectro de variación. Hemos analizado el papel de la mutación, recombinación, conversión génica y, especialmente, selección.
Por otra parte, psGBA es importante en la producción de alelos complejos GBA-psGBA, que provocan los tipos más severos de la enfermedad de Gaucher. Mostramos cómo el conocimiento de la variabilidad en psGBA ayuda al reconocimiento de estos alelos complejos.
Finalmente, con los datos de variabilidad de dos regiones parálogas situadas en la misma región cromosómica (gen GBA / pseudogen psGBA) hemos comparado los patrones de mutación que presenta una misma secuencia bajo diferentes presiones selectivas.
We have analyzed the genetic variability in a non-coding autosomal region, the pseudogene homologous to the glucocerebrosidase gene (psGBA).
Part of the analysis has been performed from the human populations point of view.
From a more genomic perspective, we have established the region dynamics in order to understand the causes of the variability pattern. We have analyzed the role of mutation, recombination, gene conversion and, especially, selection.
On the other hand, psGBA is important in the production of complex alleles GBA-psGBA, that lead to the most severe types of Gaucher disease. We show how the knowledge of psGBA variability helps to the identification of those complex alleles.
Last, from the variability data from two paralogous regions located in the same chromosomal region (GBA gene /psGBA pseudogene) we have compared the mutation patterns shown by the same sequence under different selective pressures.

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Parada, Giovanny A. "Synthesis of Biomimetic Systems for Proton and Electron Transfer Reactions in the Ground and Excited State." Doctoral thesis, Uppsala universitet, Institutionen för kemi - Ångström, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-251471.

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A detailed understanding of natural photosynthesis provides inspiration for the development of sustainable and renewable energy sources, i.e. a technology that is capable of converting solar energy directly into chemical fuels. This concept is called artificial photosynthesis. The work described in this thesis contains contributions to the development of artificial photosynthesis in two separate areas. The first one relates to light harvesting with a focus on the question of how electronic properties of photosensitizers can be tuned to allow for efficient photo-induced electron transfer processes. The study is based on a series of bis(tridentate)ruthenium(II) polypyridyl complexes, the geometric properties of which make them highly appealing for the construction of linear donor-photosensitizer-acceptor arrangements for efficient vectorial photo-induced electron transfer reactions. The chromophores possess remarkably long lived 3MLCT excited states and it is shown that their excited-state oxidation strength can be altered by variations of the ligand scaffold over a remarkably large range of 900 mV. The second area of relevance to natural and artificial photosynthesis that is discussed in this thesis relates to the coupled movement of protons and electrons. The delicate interplay between these two charged particles regulates thermodynamic and kinetic aspects in many key elementary steps of natural photosynthesis, and further studies are needed to fully understand this concept. The studies are based on redox active phenols with intramolecular hydrogen bonds to quinolines. The compounds thus bear a strong resemblance to the tyrosine/histidine couple in photosystem II, i.e. the water-plastoquinone oxidoreductase enzyme in photosynthesis. The design of the biomimetic models is such that the distance between the proton donor and acceptor is varied, enabling studies on the effect the proton transfer distance has on the rate of proton-coupled electron transfer reactions. The results of the studies have implications for the development of artificial photosynthesis, in particular in connection with redox leveling, charge accumulation, as well as electron and proton transfer. In addition to these two contributions, the excited-state dynamics of the intramolecular hydrogen-bonded phenols was investigated, thereby revealing design principles for technological applications based on excited-state intramolecular proton transfer and photoinduced tautomerization.

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Emira, Ahmed Ahmed Eladawy. "Bluetooth/WLAN receiver design methodology and IC implementations." Texas A&M University, 2003. http://hdl.handle.net/1969.1/49.

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Emerging technologies such as Bluetooth and 802.11b (Wi-Fi) have fuelled the growth of the short-range communication industry. Bluetooth, the leading WPAN (wireless personal area network) technology, was designed primarily for cable replacement applications. The first generation Bluetooth products are focused on providing low-cost radio connections among personal electronic devices. In the WLAN (wireless local area network) arena, Wi-Fi appears to be the superior product. Wi-Fi is designed for high speed internet access, with higher radio power and longer distances. Both technologies use the same 2.4GHz ISM band. The differences between Bluetooth and Wi-Fi standard features lead to a natural partitioning of applications. Nowadays, many electronics devices such as laptops and PDAs, support both Bluetooth and Wi-Fi standards to cover a wider range of applications. The cost of supporting both standards, however, is a major concern. Therefore, a dual-mode transceiver is essential to keep the size and cost of such system transceivers at a minimum. A fully integrated low-IF Bluetooth receiver is designed and implemented in a low cost, main stream 0.35um CMOS technology. The system includes the RF front end, frequency synthesizer and baseband blocks. It has -82dBm sensitivity and draws 65mA current. This project involved 6 Ph.D. students and I was in charge of the design of the channel selection complex filter is designed. In the Bluetooth transmitter, a frequency modulator with fine frequency steps is needed to generate the GFSK signal that has +/-160kHz frequency deviation. A low power ROM-less direct digital frequency synthesizer (DDFS) is designed to implement the frequency modulation. The DDFS can be used for any frequency or phase modulation communication systems that require fast frequency switching with fine frequency steps. Another contribution is the implementation of a dual-mode 802.11b/Bluetooth receiver in IBM 0.25um BiCMOS process. Direct-conversion architecture was used for both standards to achieve maximum level of integration and block sharing. I was honored to lead the efforts of 7 Ph.D. students in this project. I was responsible for system level design as well as the design of the variable gain amplifier. The receiver chip consumes 45.6/41.3mA and the sensitivity is -86/-91dBm.

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Beccaccia, Amanda Fernandes. "Uso de complexo enzimático (carbohidrase e fitase) em dietas de galinhas poedeiras." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-11102012-154716/.

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O presente experimento foi conduzido para avaliar o uso de enzimas fitase e carbohidrolase em dietas a base de milho e soja com ou sem alta concentração de fibras no desempenho produtivo e qualidade dos ovos (gravidade especifica (GE), unidade haugh (UH), espessura da casca (EC) e peso da casca (PC) de galinhas poedeiras. Foram utilizadas 320 poedeiras da linhagem comercial Hissex White, com idade inicial de 44 semanas. As aves foram alimentadas com quatro diferentes tratamentos (10 repetições de 8 cada) durante 10 semanas. As dietas incluíam: controle (T-1) a base de milho e soja com baixa concentração de fibras; (T-2) a base de milho e soja com alta concentração de fibras; (T-3) a base de milho e soja com adição do complexo enzimático e (T-4) a base de milho e soja com adição do complexo enzimático e alta concentração de fibras. As galinhas alimentadas com a dieta controle, apresentaram maior consumo de ração (CR) (P<0,05) na primeira e na quinta semanas em relação ao controle negativo (T-2). Somente na quinta semana o grupo controle obteve maior conversão alimentar (CA) (P<0,05) em relação aos outros tratamentos. Nas outras variáveis observadas, como o peso dos ovos (PO), a massa dos ovos (MO), gravidade específica (GE), unidade Haugh (UH), espessura da casca (EC) e peso da casca (PC), os diferentes tratamentos determinaram resultados similares, isso pode indicar que dietas com alta concentração de fibras e por isso de baixo custo, podem ser adotadas sem diminuição da qualidade e produção dos ovos.
The present experiment was conducted to evaluate the use of enzymes phytase and carbohydrase in corn/soybean meal diets with or without fibers regarding the productive performance and egg quality (specific gravity (SG), Haugh unit (HU), shell thickness (ST) and shell weight (SW) of laying hens. Were utilized 320 commercial line Hissex White laying hens, aged 44 weeks. The hens were fed with four different treatments (10 replicates of eight each) during 10 weeks. The diets included control (T-1) based of corn, soybean meal and low concentration of fibers; (T-2) based of corn, soybean meal and high concentration of fibers; (T-3) based of maize and soybean meal supplemented with enzymes and (T-4) based of corn and soybean meal supplemented with enzymes and high concentration of fibers. The laying hens fed with the control diet (T-1) showed higher feed intake (FI) (P<0,05) in the first and fifth weeks in relation to the negative control (T-2). Only in the fifth week the control group had higher feed conversion (FC) (P<0,05) in relation with the other treatments. In the other variables observed, the different treatments showed similar results, it may indicate that diets with high fiber concentration and therefore low cost can be taken without decreasing the quality and egg production.

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Li, Bo. "Chaîne respiratoire et pore de transition de perméabilité mitochondriale dans la cardioprotection." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00609514.

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Le pore de transition de perméabilité mitochondriale (PTPm) joue un rôle majeur dans la mort cellulaire et dans la cardioprotection. Notre hypothèse est que le complexe I de la chaîne respiratoire est impliqué dans la régulation de l'ouverture du PTPm. Sur des mitochondries isolées de cœurs des rongeurs, nous avons pu démontrer que le PTPm est désensibilisé par la cyclosporine A, un inhibiteur de la cyclophiline D (CyP-D), et cet effet est largement amplifié en présence de la roténone, un inhibiteur du complexe I. Ces résultats ont été confirmés chez la souris CyP-D déficiente. L'étude de plusieurs types cellulaires a aussi confirmé l'effet de la roténone dans la régulation du PTPm. Ainsi, nous avons pu montrer que le flux d'électrons travers le complexe I est capable de réagir sur un site de régulation du PTPm cardiaque masqué par la CyP-D. De plus, les analogues de l'ubiquinone, élément de la chaîne respiratoire impliqué dans le transfert d'électrons entre les complexes I, II et III, modulent la susceptibilité du PTPm vis-à-vis du Ca2+. Par ailleurs, dans un modèle de cœur isolé du rat, le postconditionnement par le perindoprilate, un inhibiteur de l'enzyme de conversion, diminue la taille de l'infarctus après l'ischémie-reperfusion d'une façon NO-dépendant. L'ensemble de nos résultats ouvre de nouvelles perspectives thérapeutiques dans la cardioprotection et montre l'importance du complexe I et de la CyP-D comme cibles moléculaires incontournables dans la cardioprotection

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Patrocinio, Antonio Otávio de Toledo. "Complexos de Re(I) e filmes de TiO2 em dispositivos moleculares fotoinduzidos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/46/46134/tde-10122009-134525/.

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A tese foca dois tópicos principais: a caracterização de filmes de TiO 2para aplicação em células solares sensibilizadas por corantes, DSCs, e a investigação das propriedades fotoquímicas e fotofísicas de complexos polipiridínicos de Re(I). Filmes mesoporosos de TiO2 foram preparados pela rota sol-gel e pelo óxido comercial P25 (Degussa) e foram caracterizados por XRD, SEM, B.E.T e XPS. Ambos os óxidos foram empregados com sucesso nas células solares, mas os filmes do óxido preparado pela rota sol-gel são mais transparentes e adequados para a aplicação em janelas inteligentes. Já as DSCs com o óxido P25 possuem maior eficiência de conversão entre 600 e 800 nm devido ao maior espalhamento de luz nessa região causado pela presença de agregados de nanopartículas no filme mesoporoso. Os substratos condutores foram tratados com soluções de TiCl4 formando uma camada de bloqueio que diminui as reações de recombinação nas DSCs. Isso provoca um aumento da eficiência do dispositivo, de 5,7 para 6,5%. Efeito similar foi observado tratandose a superfície dos filmes de TiO2 com TiCl4, o que resultou num aumento da eficiência de transporte de elétrons nos óxidos obtidos pela rotas sol-gel tanto ácida quanto básica. O TiO2 obtido pela rota básica adsorve menos corante, mas possui melhor eficiência de coleta e separação de cargas. A sobreposição dos filmes nas células solares resulta em eficiências de 5,8%. DSCs com extratos de amora, framboesa ou mirtilo foram investigadas e avaliadas pela composição dos extratos, pelos espectros eletrônicos e de ação. A radiação prolongada da célula solar com extrato de amora, que apresentou a melhor eficiência de conversão, comprovou a estabilidade do dispositivo por no mínimo 36 semanas. Os complexos polipiridínicos de Re(I) fac-[Re(CO)3(Me4phen)(trans-L)]PF6, L = stpy ou bpe, e fac-[Re(CO)3(dppz)(trans-bpe)]PF6 foram sintetizados e caracterizados quanto às suas propriedades espectrais, fotoquímicas e fotofísicas. As variações espectrais sob irradiação em 313, 334, 365 ou 404 nm são atribuídas à isomerização trans-cis do ligante coordenado. Os rendimentos quânticos reais do processo, F, foram determinados por 1H RMN em conjunto com espectrofotometria. Os complexos com trans-bpe possuem Φ independentes do comprimento de onda de irradiação com valores médios de 0,32 para o complexo com Me4phen, e 0,37 para o complexo com dppz. Já o fac- [Re(CO)3(Me4phen)(trans-stpy)]+ apresenta Φ maiores para irradiações entre 313 e 365 nm (0,59), do que em 404 nm (0,31). A dependência do comprimento de onda de irradiação indica que mais de um mecanismo de isomerização está ocorrendo no complexo com transstpy. Os fotoprodutos, cis-complexos, são luminescentes em acetonitrila a 298 K. Os complexos com Me4phen podem ser reconvertidos no isômero trans sob irradiação a 254 nm, com rendimentos quânticos de aproximadamente 0,15. O decaimento da emissão desses complexos foi investigado em diferentes meios e a diferentes temperaturas. O comportamento emissivo foi racionalizado em função da energia relativa dos estados excitados e um mecanismo para desativação foi proposto com a conversão interna do estado 3ILMe4phen para o 3MLCTRe→Me4phen envolvendo uma barreira de energia
The thesis focus on two main topics: characterization of TiO2 films for Dye-sensitized solar cells, DSCs, and investigation on photochemical and photophysical properties of Re(I) polypyridyl complexes. Mesoporous TiO2 films were prepared by sol-gel method and by commercial oxide (P25, Degussa) and were characterized by XRD, SEM, B.E.T. and XPS. Both oxides were successfully employed in solar cells. Sol-gel TiO2 films are more transparent and, therefore, adequate for application on smart windows. On the other hand, DSCs with the P25 oxide have higher conversion efficiency in 600-800 nm region, due to the light scattering caused by nanoparticle aggregates in the mesoporous film. Conductive substrates were treated with TiCl4 solutions to deposit a blocking layer that decreases recombination reactions in DSCs. The treatment enhances the efficiency of the device, from 5.7 to 6.5%. Similar effect was observed by treating the surface of TiO2 films in the same way. The improvement was attributed to the enhancement of the electron transport efficiency in TiO2 films prepared by both, acid or basic sol-gel methods. Dye adsorption on TiO2 obtained by the basic method is lower, however the oxide has higher efficiencies of charge harvesting and charge separation. The use of both films in DSCs, one over the other, results in an efficiency of 5.8%. DSCs with natural extracts of mulberry, raspberry and blueberry were investigated analyzing extract compositions, electronic and action spectra. Long term radiation of DSCs with the mulberry solar cell, which has the highest efficiency, showed the device stability at least for 36 weeks. Re(I) polypyridyl complexes, fac-[Re(CO)3(Me4phen)(trans-L)]PF6, L = stpy or bpe, and fac-[Re(CO)3(dppz)(trans-bpe)]PF6 were synthesized and characterized by their spectral, photochemical and photophysical properties. Spectral changes under 313, 334, 365 or 404 nm irradiation are attributed to the trans-to-cis isomerization of the coordinated ligand. True quantum yields of the process, Φ, were determined by 1H NMR associated to UV-vis spectroscopy. The quantum yields for fac-[Re(CO)3(Me4phen)(trans-bpe)] (Φ = 0.32) and fac- [Re(CO)3(dppz)(trans-bpe)] (F = 0.37) are irradiation wavelength independent. On the other hand, F for fac-[Re(CO)3(Me4phen)(trans-stpy)]+ are higher for 313, 334 and 365 nm irradiation (0.59), than at 404 nm irradiation (0.31). This indicates the occurrence of more than one isomerization pathway in the trans-stpy complex. The photoproducts, cis-complexes, are luminescent in acetonitrile at 298 K. The Me4phen complexes can be back converted to the trans isomers with quantum yields of 0.15 under 254 nm irradiation. The emission decay of these complexes was investigated in different media and at several temperatures. The luminescence behavior was rationalized in terms of the relative energy of excited states. A deactivation pathway is proposed considering the internal conversion of the 3ILMe4phen to the 3MLCTRe→Me4phen excited states with an energy barrier

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Zanoni, Kassio Papi da Silva. "Compostos de coordenação de Ir(III), Re(I) e Ru(II) para aplicações em dispositivos moleculares." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-27042018-081643/.

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Esta tese focou em três tópicos principais: caracterização de filmes compactos de TiO2 e seu comportamento em células solares sensibilizadas por corante; estudo das propriedades fotoquímicas e fotofísicas de um complexo fotoisomerizável de rênio(I); elucidação das propriedades fotofísicas e eletrônicas de complexos de irídio(III) e suas aplicações em dispositivos emissores de luz. Filmes compactos foram automontados nos fotoanodos de células solares sensibilizadas por corante (DSCs), sob o filme mesoporoso de TiO2/corante, utilizando sols de TiO2 ácidos e básicos como cátions e ânions, respectivamente. A obtenção dos sols foi realizada sob controle absoluto para resultar em propriedades morfológicas e ópticas apropriadas para filmes compactos de alta qualidade, como indicado por perfilometria e microscopia eletrônica de transmissão e varredura. As DSCs com bicamadas de TiO2 melhoraram as eficiências de conversão em até 62%. Uma investigação detalhada por parâmetros fotoeletroquímicos, IPCE, tempo de vida do elétron e espectroscopia de impedância eletroquímica demonstrou que o contato entre o vidro condutor (FTO) e o TiO2 é melhorado e que a recombinação de carga no FTO/I3- é diminuída. O novo complexo fac-[Re(CO)3(Ph2phen)(trans-stpyCN)]+ foi sintetizado para apresentar o intercâmbio entre as configurações trans e cis do ligante coordenado por meio de fotoisomerizações eficientes e reversíveis. As fotólises em 313, 334, 365 e404 nm resultam em mudanças espectrais no UV-Vis e RMN atribuídas à fotoisomerização trans-cis do ligante stpyCN coordenado. O processo reverso cis-trans também foi observado com irradiação em 255 nm, com um notável rendimento quântico (Φ = 0,16), de mesma magnitude que para o processo trans-cis (Φ = 0,38). A caracterização fotofísica e os espectros de absorção do transiente corroboraram na atribuição de um comportamento incomum para os estados excitados quasedegenerados 3ILstpyCN e 3MLCTRe→Ph2phen. Complexos heterolépticos de Ir(III) foram sintetizados e suas propriedades fotofísicas avaliadas, como rendimentos quânticos e tempos de vida de emissão, constantes radiativas e não-radiativas e coordenadas CIE. Os parâmetros fotofísicos variaram sistematicamente com variações nos substituintes retiradores ou doares de elétrons, como corroborado por cálculos TD-DFT, que mostraram uma mistura de estados excitados IL-MLCT. Três desses complexos foram utilizados na camada ativa de dispositivos emissores de luz e caracterizados optoeletronicamente por curvas de corrente-brilho-potencial e espectros eletroluminescentes.
Three main topics are discussed in this thesis: characterization of TiO2 compact films towards high-performance dye-sensitized solar cells; investigations of photophysical and photochemical processes of a Re(I) complex; photophysical elucidation of Ir(III) complexes and their application in light emitting devices. All-nano-TiO2 compact films were auto-assembled in the photoanodes of dyesensitized solar cells (DSCs), beneath the TiO2 mesoporous film, employing acid and basic nano-TiO2 sols as cations and anions, respectively. TiO2 syntheses were performed under absolute control to lead to appropriate morphological and optical properties to yield high quality compact films, as indicated by profilometry, tunning and scanning electron microscopy. DSCs with TiO2 bilayers on top of the conducting glass (FTO) improved the conversion efficiency up to 62%. A detailed study by photoelectrochemical parameters, IPCE, electron lifetime and electrochemical impedance spectroscopy demonstrates that the contact between FTO and TiO2 was improved and that the FTO/I3- charge recombination was prevented. The novel fac-[Re(CO)3(Ph2phen)(trans-stpyCN)]+ complex was synthesized to show switchable trans-cis configurations of the coordinated stpyCN ligand through efficient and reversible photoassisted isomerizations. Photolyses at 313, 334, 365 and 404 nm led to UV-Vis and NMR spectral changes ascribed to the trans-to-cis photoisomerization of the coordinated ligand. The reverse cis-to-trans process was alsoobserved at 255 nm irradiation, with a remarkable quantum yield (Φ = 0.16), in the same magnitude to the one for trans-to-cis photoprocess (Φ = 0.38). Photophysical characterization and transient absorption spectra provided insights on the light-driven trans ? cis pathways and indicated an unusual behavior for the 3ILstpyCN excited state, induced by an interplay with the quasi-degenerated 3MLCTRePh2phen state. Heteroleptic Ir(III) complexes were synthesized and phophysical properties evaluated, such as emission quantum yields and lifetimes, radiative and non-radiative constants and CIE coordinates. The photophysical parameters varied systematically with variations in electron-donating or -withdrawing substituents on the ligands, as corroborated by TD-DFT calculations that showed an IL-MLCT mixing in their emissive excited state. Three complexes were employed in the active layer of light emitting devices and had their optoeletronic properties characterized by current-brightness-voltage curves and electroluminescent spectra.

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Cartier, dit Moulin Christophe. "Structures fines d'absorption des rayons X de complexes moléculaires d'éléments de transition de la premiere période." Paris 11, 1988. http://www.theses.fr/1988PA112002.

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Ce travail est consacré à l'étude par spectroscopie d'absorption des rayons X de complexes moléculaires d'éléments de transition de la première période. Une première partie porte sur l'étude fondamentale des structures fines au seuil d'absorption : nous utilisons la flexibilité de la chimie de coordination pour étudier des complexes de stéréochimie et de structure électronique variées. Pour des molécules discrètes de structure connue, nous mettons en évidence l'influence sur le seuil du degré d'oxydation et de l'état de spin de l'élément de transition, de la symétrie du site, des distances métal-ligand et des différentes couches de voisins. Nous interprétons les transitions vers des états liés dans une approche orbitale moléculaire. Dans le domaine d'énergie où le photoélectron est éjecté, nous utilisons l'approche "diffusion multiple". L'intérêt et les limites des deux modèles sont discutés. Enfin, la présence de bandes d'intensité faible est attribuée à des transitions biélectroniques. La compréhension de l'influence des différents paramètres électroniques et structuraux qui déterminent les structures fines du seuil, et l'analyse EXAFS, sont ensuite utilisées pour l'étude structurale et stéréochimique de matériaux nouveaux intéressants pour leurs propriétés physiques, chimiques et catalytiques. Nous avons ainsi caractérisé :- les modifications structurales associées aux transitions de spin dans des complexes du fer(ll), du fer(lll) et du cobalt(ll). - la stéréochimie de complexes du titane(IV), actifs dans l'oxydation de sulfures en sulfoxydes : à toutes les étapes de la réaction, les espèces sont octaédriques et ne présentent pas d'arrangement di -oxo. - l'ordre local dans les porphyrines de fer à anse de panier, modèles de l'hémoglobine. Le spectre de la forme oxygénée permet de proposer une formulation Fe(ll)-02 plutôt que Fe(lll)-02 -. L'EXAFS résolu dans le temps permet de réaliser des cinétiques structurales et a été utilisé pour étudier l'environnement de l'ion fer au cours de la réaction d'oxydation d'une porphyrine de fer(ll) à anse de panier
Ln this work, molecular complexes of the first period transition elements are studied by X-ray absorption spectroscopy. The first point is devoted to a fundamental study of the absorption edge: we take advantage of the versatility of coordination chemistry, to study complexes, with different stereochemistries and electronic structures. Ln the case of isolated molecules with well-known structures, we point out the influence of oxidation and spin states of the metallic ion, symmetry, metal-ligand distances and remote neighbours shells upon the edge. We discuss the transitions towards bound states using a molecular orbital approach. As for the XANES part of the spectrum, we use multiple scattering theory. We discuss the interest and the limitations of the two models. Sorne weak bands can be attributed to bielectronic transitions. This knowledge of the influence of different structural and electronic parameters which impel the fine structures of the edge and EXAFS spectroscopy are then used to characterise the local structure and stereochemistry of new compounds, of interest for their physical, chemical and catalytic properties. Then we studied:- The structural changes occurring during thermal spin cross-over in iron(ll), iron(lll) and cobalt(ll) complexes. - The stereochemistry of titanium(IV) complexes active in oxidation of sulfides in sulfoxides :at each reaction step, species are octahedral and do not show di µ oxo geometry. - The local order in basket-handle iron porphyrins, model compounds of haemoglobin. The spectrum of the oxy species allows to propose a Fe(ll)-02 formulation rather than a Fe(lll)-02 -. We used the time resolved EXAFS spectrometer at LURE to record structural kinetics data and study iron surroundings during the oxidation of an iron(ll) basket-handle porphyrin

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Dahl, Mads Ronald. "Mannan-binding lectin (MBL) associated serine protease-3 (MASP-3) : complex formation in serum and plasma, conditions required for the conversion of the zymogen form into a two-chain serin protease, and a search for substrates using recombinant material produced by stable expression in eukaryotic cell lines." Thesis, University of Leicester, 2004. http://hdl.handle.net/2381/29483.

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The complement system is part of the innate immune system and is crucial for identifying invading microorganisms. The lectin pathway of complement activation is initiated through multimeric macromolecules which recognise pathogen-associated patterns and translate binding through activation of associated serine proteases that start a cascade of proteolytic events leading to bactericidal, opsonising and proinflammatory responses. Mannan-binding lectin (MBL) is one of the macromolecules mediating binding to specific carbohydrate structures common to a range of microorganisms. Three different mannan-binding lectin associated serine proteases (MASP-1/-2/-3) and a non-enzymatic protein of 19 kDa (MApl9) have been described. MASP-2 appears to mediate all processes required for complement activation while little or no complement-related functional activity was found to be mediated by MASP-1, MASP-3 or MApl9. Functional and biophysical studies of MASP-3 relied on continuous and reliable supply of recombinant MASP-3. In this work production of recombinant MASP-3 in mammalian cells with subsequent affinity purification and characterisation of the recombinant MASP-3 was performed to obtain large quantities of homogeneous enzyme. The development of screening assays and assays for quantitative determination of MASP-3 levels were two other tools essential for the development of this thesis. As a result of this thesis MASP-3 levels in different body fluids were determined in healthy individuals using a quantitative assay. The assays were used to analyse the MASP-3 level in sample collections from patients suffering from Alzheimer disease and type-1 diabetes. The correlation of MASP-3 level and MBL genotype, H-/L-Ficolin concentration, age, BMI, acute phase and time of year were analysed. The enzymatic activity of MASP-3 was analysed on chromogenic substrates and the results permitted a study of MASP-3 inhibition. Attempts were made to affinity purify potential MASP-3 substrates and ligands using beads coupled with recombinant MASP-3 and anti- MASP-3 antibodies. The influence of calcium on MASP-3 complex formation, dissociation, activation and stability was analysed.

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Gates, Sarah. "Investigating transition metal formyl complexes for homogeneous syngas conversion." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/39274.

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The conversion of synthesis gas, (syngas; a mixture of CO and H2), to liquid fuels has been a process that has been studied for more than a century. Current heterogeneous operating procedures are poorly understood and as such are unselective, requiring costly refining to separate the desired products. It has long been hoped that an alternative homogenous process may allow for the mechanistic insight and understanding to rationally design the conversion of syngas to specific products. This thesis aims to explore the steric and electronic environment of the carbonyl ligand within iron transition metal complexes, as a model for homogenous syngas conversion. Particular attention has been paid to the first step of syngas conversion; hydride transfer to form a formyl complex. Chapter 1 provides a general overview of the developments to date, in both heterogeneous and homogenous systems for syngas conversion. The use of frustrated Lewis pairs to hydrogenate a carbonyl directly from hydrogen is also discussed in addition to a discussion of the various mechanisms and intermediates present in a homogenous system. Chapter 2 describes the reduction and subsequent reactivity of the carbonyl complex [Fe(CO)2(Cp*)][BArF24]. Hydrogenation, directly using hydrogen gas in conjunction with FLP systems is discussed. Chapter 3 describes the use of bisphosphine ligands to impart electron density and stability to transition metal formyl complexes. This work is also discussed in relation to FLP hydrogenation. Chapter 4 gives an overview of the reactivity of some neutral carbonyl complexes and their reactivity with FLP systems. Chapter 5 provides an alternative approach for future homogenous transition metal carbonyl reduction chemistry. Some preliminary results are included to support the investigation of such a route for further study. Chapter 6 details experimental procedures used in this work.

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Puttock, Emma Victoria. "Transition metal complexes and their applications in energy conversion." Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12234/.

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The rich coordination chemistry of transition metals renders them of interest for broad applications in energy conversion. For example, there is increasing interest in molecular light absorbers such as dye-sensitized photoelectrochemical solar cells (DSSCs) and hybrid inorganic/organic devices. Additionally, the properties of light emitting molecules are the subject of intense research, with applications in organic light emitting diodes (OLEDs) and photosensitisers of energy- and electron-transfer for solar energy conversion. This thesis can be broadly separated into two sections; (1) the study of a macrocyclic cobalt complex and its potential as a catalyst for the conversion of protons into H2 and (2) the synthesis and study of transition metal complexes as phosphorescent dopants for OLEDs. In part 1, the synthesis and characterisation of a series of cobalt compounds coordinated by the macrocyclic biquinazoline ligand, Mabiq, is presented. The solution and solid-state structures of the compounds were examined, alongside the electronic structures of paramagnetic 2 and 3. Electrochemistry data reveals that the reduction of 4 is possible to form a formally Co0 species, which shows promise in its activity with respect to H2 production. In part 2, the synthesis and characterisation of a range of mono- and bimetallic Pt(II) and Ir(III) complexes is presented. A series of readily synthesised tridentate proligands and their resulting complexes is presented that include pseudo-cyclometallating units to allow for mild reaction conditions. The complexes are weakly emissive, with PLQYs in the range 0.1 – 4%, attributed to varying rates of non-radiative decay. Two successful strategies in decreasing non-radiative decay are reported: the replacement of the chloride ancillary ligand with a stronger field acetylide ligand and the development of tetradentate proligands to improve the rigidity of the square planar complexes. The synthesis of hydrazone-based proligands, which offer two N^N^O-coordination sites bridged by a central pyrimidine ring is also reported. Coordination of a second Ir(III) centre results in a 6-fold enhancement of the PLQYs.

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Hurvy, Caroline. "Remaniements oedipiens à l'adolescence : étude psychodynamique et projective des symptômes de conversion somatique." Paris 5, 2008. http://www.theses.fr/2008PA05H058.

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La survenue de symptômes de conversion somatique chez de jeunes patients, au moment où s'amorce le processus pubertaire, soulève un double questionnement: d'une part celui relatif au lien entre l'hystérie et la conversion, les deux étant classiquement associés, et d'autre part celui portant sur la distinction entre névrose de l'enfant en tant qu'entité psychopathologique. Afin de mettre à l'épreuve nos interrogations et d'approfondir notre compréhension du phénomène de conversion au regard de l'économie psychique globale du sujet, nous avons recueilli et analysé les épreuves projectives de 18 patients, âgés de 10 à 16 ans, présentant un ou plusieurs symptômes de conversion somatique (diagnostique établi après exclusion d'une pathologie organique et selon les critères du DSM-IV-R). L'investigation psychologique s'inscrit dans le cadre plus large d'une recherche (Dr Lisa Ouss, Hôpital Necker) mise en place dans le but d'améliorer la connaissance de cette population et les modalités de prise en charge proposées. L'analyse des données dasn une perspective analytique nous a permis de démontrer que la conversion n'apparaissait pas systématiquement chez des patients présentant une organisation psychique de type hystérique, bien que celle-ci s'inscrive majoritairement dans des fonctionnements de type névrotique (c'est le cas de 16 patients sur 18). Nous avons en effet relevé, pour la plupart des sujets, le caractère structurant du conflit oedipien, dont l'impact fantasmatique se charge d'une valeur traumatique au moment de l'adolescence: le Moi recourt à la conversion, une solution défensive, lorsque celui-ci est débordé dans ces capacités de traitement de l'énergie pulsionnelle. La conversion réalise un compromis économique mais aussi dynamique, dans le sens où elle participe des remaniements identificatoires et relationnels imposés par l'accès à la génitalité
The present research suggests studying, in support of the projective technique (Rorschach, TAT), the specificity of psychic functioning of a population of preteenagers and teenagers (from 10 to 16 years old) presenting one or several symptoms of somatic conversion. Through the hypothesis of an embrittlement of the excitement by the subject, because of the juvenile transformations (current or imminent), we tried to update the way the conversion realizes compromise so economic as dynamic, in the sense where it participates identification and relational reorganizations imposed by the access on the genitality

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Henderson-Brooks, Caroline Kay. ""What type of person am I, Tess?" the complex tale of self in psychotherapy /." Phd thesis, Australia : Macquarie University, 2006. http://hdl.handle.net/1959.14/22504.

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Thesis (PhD)--Macquarie University, Division of Linguistics & Psychology, Department of Linguistics, 2006.
Bibliography: p. 319-326.
Introduction: the complex tale of self in psychotherapy -- Literature review -- Introduction to the corpora and general linguistic analysis -- Introduction to the lexicogrammatical analysis of scripts, chronicles and narratives -- Chronicles: this is my normality: the complex tale of the everyday -- Scripts: I am not normal: the complex tale of alienation -- Narratives: this is how I would like normal to be: the complex tale of normality as imagination and memory -- A complex tale of normality: lexicogrammatical features across scripts, chronicles and narratives -- The contexts of psychotherapy -- Generic structure -- A complex tale of self.
This thesis investigates the complex tales of self which emerge from conversations between psychotherapists and patients with borderline personality disorder. These patients struggle in establishing a border between themselves and significant others, which is itself fundamental to a deeper construal of their own existence. They are being treated within the Conversational Model of psychotherapy. The model is strongly oriented to techniques based on language and linguistic evidence and thus offers a linguistic site at which the study of the complex interaction of self and language can be made tractable.--Within a broad corpus of transcribed audio recordings of patient-therapist discourse, the principal focus of my linguistic study is the Conversational Model's claims about three conversational types-Scripts, Chronicles and Narratives. According to Meares, they present 'self as shifting state in the therapeutic conversation' (1998:876). The thesis investigates a selection of texts to represent these three conversational types, which I have chosen according to the claims in the Conversational Model literature. It tests the evidence of Meares' claims concerning the semantic characteristics which distinguish the three conversational types, as well as the linguistic evidence concerning the claims of change in the self in particular the presentation of 'self as shifting state' (1998:876). To achieve the levels of complexity required for this linguistic study of self, this thesis uses Systemic Functional Linguistics, which has a social, interactional orientation and a multidimensional and in particular, multistratal approach. The research demonstrates that therapeutically relevant aspects of the self can be productively described, across linguistic strata, in a consistent and reproducible way as a construction of meaning. The meanings which speakers offer in wordings can provide a reliable index for evaluating the emergence and maintenance of self. The Conversational Model's 'conversations' are confirmed as linguistically distinguishable text types and the research further shows that key terms of the Conversational Model can be defended theoretically on the basis of linguistic evidence, for example, the contrastive linearlnon-linear. Together the findings describe the complexity in the tale of self.--This investigation of the Conversational Model data also tests the claims of a functional linguistics at the same time that it evaluates the Conversational Model with respect to that model's consistent appeals to language as evidence. It establishes an opportunity to extend the dialogue between linguists and practitioners of the Conversational Model: the tools of the one group increase the reflective capabilities of the other.
Mode of access: World Wide Web.
xx, 385 p. ill

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29

Baranauskas, Victor Vincent. "Cobalt Nanoparticle-Macromolecular Complexes and Their Conversion to Oxidatively Stable Entities." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27376.

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The goal of the research presented in this dissertation was to synthesize novel macromolecular materials that would afford oxidative stability to magnetic cobalt nanoparticles under ambient conditions. The cobalt nanoparticles were formed via the thermolysis of Co2(CO)8 in concentrated solutions of toluene containing the macromolecular dispersion stabilizers. The copolymers were designed to encapsulate the nanoparticles with a number of thin protective coatings to prevent their undesirable oxidation under ambient condtions. Cobalt nanoparticles encased with an organic glass were synthesized by stabilizing cobalt nanoparticles with poly(methyl methacrylate-co-2-vinylpyridine-g-dimethylsiloxane) whereas nanoparticles encapsulated with triazine networks were formed via the thermal treatment of cobalt particles complexed with poly(styrene-b-4-vinylphenylcyanate). Cobalt nanoparticles coated with a combination of carbonaceous and silica char were obtained by pyrolyzing cobalt particles stabilized with poly (4-vinylphenoxyphthalonitrile-co-4-vinylphenoxytriethoxysilane-g-dimethylsiloxane) graft copolymers. Moreover, cobalt nanoparticles encapsulated with either phthalonitrile networks or graphitic char were prepared via the thermal treatment of nanoparticles stabilized with poly(styrene-b-4-vinylphenoxyphthalonitrile). Oxidatively-stable, magnetic cobalt nanoparticle complexes may be prepared by heating cobalt nanoparticles encapsulated in poly(styrene-b-4-vinylphenoxyphthalonitrile) block copolymers at elevated temperatures. The block copolymers were synthesized through the sequential anionic polymerization of styrene and tert-butyldimethylsilyloxystyrene. The silyl ether protecting groups on the second block were hydrolyzed under acidic conditions to afford poly(styrene-b-4-vinylphenol), and the pendent phenols of the diblock copolymer were chemically modified with 4-nitrophthalonitrile to afford poly(styrene-b-4-vinylphenoxyphthalonitrile). Stable suspensions of ~8-10 nm diameter cobalt metal nanoparticles were formed by thermolysis of dicobalt octacarbonyl in solutions of toluene containing poly(styrene-b-4-vinylphenoxyphthalonitrile). The cobalt-polymer nanoparticle complexes were pyrolyzed under argon to afford highly magnetic cobalt nanoparticles encased in graphitic coatings. Magnetic susceptibility measurements indicate that the cobalt-graphitic particles are oxidatively-stable and retain their high saturation magnetizations (~ 95-100 emu g-1) for at least a year under ambient conditions.
Ph. D.

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30

Chamoire, Audrey. "Antimoniures Complexes de Type Th3P4 et Propriétés Thermoélectriques." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2009. http://tel.archives-ouvertes.fr/tel-00519209.

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Ce travail de thèse concerne l'étude d'antimoniures complexes de type Th3P4 et leurs potentiels en tant que matériaux de type p pour la génération thermoélectrique de courant. De tels matériaux sont caractérisés par le facteur de mérite ZT=α2T/ρκ, où α est le coefficient de Seebeck, ρ la résistivité électrique et κ la conductivité thermique. Les composés binaires R4Sb3 (R = La, Ce, Sm and Yb), ternaires Yb4-xR'xSb3 (R'= La, Sm, Ce et Eu) et Yb4Sb3-yXy (X=Se, Te, As, Bi et I) ont été synthétisés par réaction à haute température et cristallisent dans le type structural anti-Th3P4(I-43d N°220). Les caractérisations structurales et chimiques ont été réalisées par diffractions des rayons X sur poudre (DRX) et par microscopie électronique à balayage (MEB) couplée à de la spectrométrie des rayons X à dispersion d'énergie (EDS). Les poudres on été densifiées par frittage flash (SPS) à 1573K sous une pression de 100Mpa. Les propriétés de transport ont été mesurées de la température ambiante jusqu'à 1273K. Elles indiquent que la conduction des composés binaires est dominée par les électrons et présentent un faible coefficient de Seebeck. Seul Yb4Sb3 montre un comportement typiquement métallique de type p. Les mesures de susceptibilité magnétiques réalisées sur ce composé indiquent que l'ytterbium est principalement divalent et la substitution de ce dernier par d'autres terres rares trivalentes ainsi que la substitution de l'antimoine par des chalcogènes, nous ont permis d'améliorer les propriétés thermoélectriques à haute température faisant de ces matériaux des éléments prometteurs pour la génération d'électricité par effet thermoélectrique.

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31

Pasquet, Nicolas. "Pour une compréhension complexe des processus de bifurcation technologique : le temps-devenir : le cas de l'énergie solaire photovoltaïque." Châtenay-Malabry, Ecole centrale de Paris, 2002. http://www.theses.fr/2002ECAP0946.

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Cette recherche a pour objet d'étude et de connaissance la technique entendue comme système. Elle s'inscrit dans le fil de questionnements sur le changement, le temps, la nouveauté et la complexité des objets techniques tels qu'ils nous apparaissent quotidiennement. Ce travail se fixe pour projet de rendre plus lisible et intelligible les processus de bifurcation technologique à l'œuvre dans la remise en cause des situations de verrouillage technologique, plus particulièrement en se basant sur l'étude du cas de l'énergie solaire photovoltai͏̈que. Cette recherche intéresse les Sciences de Gestion, et à plus forte raison le Management Stratégique de l'Innovation et de la Technologie, dans la mesure où les entreprises cherchent à se doter d'outils stratégiques capables d'éclairer l'avenir afin de s'adapter le plus rapidement et le plus efficacement possible à un environnement turbulent. Le modèle auquel nous parvenons permet de réconcilier à la fois le global et le local, de dévoiler les multiples dimensions de la technique, et d'envisager la nouveauté en devenir au-delà d'une simple apparence. Plus encore, il réhabilite la notion d'évènement, perçue comme étant la rencontre entre le temps des opportunités et l'espace des possibles.

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32

Chen, Ming-Chou. "Metallacyclobutenes as reactive intermediates : conversion to cobalt diene and cobalt allene complexes /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9834967.

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33

Hošťálek, Zdeněk. "Conversion de catalyseurs d'oxydes de carbone en nouveaux matériaux polymères." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0016/document.

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Plusieurs complexes de salphen à base de métaux transition (Cr, Co, Fe) ont été synthétisés et utilisés comme catalyseurs pour la copolymérisation d’époxydes avec du monoxyde de carbone (CO), des anhydrides ou du dioxyde de carbone (CO2). De nouveaux complexes à base de Zn, Al, Mg ont également été testés pour la copolymérisation d’époxydes avec CO2.La partie première s’intéresse principalement à la copolymérisation d’oxyde de propylène avec du monoxyde de carbone. Le complexe salphen de chrome et Co2(CO)8 ont été utilisées comme catalyseurs. Quel que soit le complexe utilisé, il a été observé une faible activité et les produits de carbonylation attendus (polyester et lactone) ont été obtenus en faible quantité. En revanche, la combinaison in-situ de ces deux catalyseurs a montré une activité supérieure. Cela a conduit à la formation de la lactone cyclique (β-butyrolactone) et de poly(ester-co-éther) de faible masse molaire, ce qui marque une faible compatibilité de ces complexes.La partie suivante traite de la copolymérisation d’époxydes avec des anhydrides catalysée par des complexes de salphen à base de chrome et fer ou d’une base organique simple. Les complexes utilisés sans co-catalyseur ont été inactifs, mais la combinaison avec la base organique (PPNCl) comme co-catalyseur a conduit à la copolymérisation alternée des deux monomères, produisant des polyesters avec des masses molaires jusqu’ à 10 kg.mol-1 et une faible dispersité. PPNCl s’est révélée être la base la plus efficace pour la copolymérisation alternée des époxydes et des anhydrides. Les bases organiques simples utilisées seules ont aussi permis l’obtention de polyesters, mais avec des temps de polymérisation cinq fois plus longs.Enfin, la troisième partie présente la copolymérisation des époxydes avec CO2 en présence de complexes salphen de Cr ou de Co. Les complexes salphen cobalt ont été significativement plus efficaces pour la copolymérisation de l’oxyde de propylène (PO) ou de l’oxyde de cyclohexène (CHO) avec CO2 que leurs homologues à base de chrome. Les polycarbonates obtenus avec les complexes de cobalt ont plus de 99% d’unités carbonate, des masses molaires allant de 10 à 35 kg.mol-1 et une faible dispersité. Les études cinétiques ont permis de montrer que la polymérisation est contrôlée. Des analyses par spectrométrie de masse MALDI-TOF ont permis de vérifier la microstructure et le mécanisme d’activation. Toutefois, pour la copolymérisation de PO avec CO2, les complexes salphen cobalt ont une activité plus faible (100-450 h-1) ainsi qu’une sélectivité en polycarbonate moindre (40-90%) que les complexes salen cobalt. Une sélectivité de 100% vers la synthèse de polycarbonate a néanmoins pu être obtenue lors de la copolymérisation de CHO avec CO2. Enfin, les complexes β-diminate, ketiminate et aminidate d’Al, Zn et Mg utilisés pour la copolymérisation d’époxydes avec CO2 se sont révélés décevants car présentant une activité très faible et seuls des homopolyéthers ont été obtenus
A series of salphen complexes based on Cr, Co and Fe was synthesized and used as catalysts in ring-opening copolymerization of different substrates: (i) epoxides with carbon monoxide (CO), (ii) epoxides with anhydrides and (iii) epoxides with carbon dioxide (CO2). Additionally, a screening of catalytic activity for the last substrate was performed with novel Zn, Al and Mg non-salen based complexes.The first part of the Thesis deals with the copolymerization of propylene oxide with carbon monoxide using asymmetric salphen chromium complex and Co2(CO)8 in order to prepare a synthetic equivalent of polyhydroxybutyrate (PHB) otherwise accessible by fermentation of various substrates. Very poor catalytic performances towards carbonylated products (PHB or β-butyrolactone (BBL)) were observed with any of the two complexes. The combination of both salphen chromium and Co2(CO)8 complexes led to increased formation of BBL. Low molar mass poly(ester-co-ether) was only prepared, suggesting a poor compatibility of selected complexes.The second part of the work is focused on the copolymerization of epoxides with anhydrides catalyzed by salphen chromium or iron complexes combined with simple organic bases as cocatalysts. Salphen complexes alone were almost inactive, while in the presence of bis(triphenylphosphineiminium)chloride (PPNCl) they afforded highly alternating polyesters with molar mass up to 10 kg.mol-1 and low dispersity. Surprisingly, organic bases alone afforded similar, highly alternating polyesters at five-time lower polymerization rate. PPNCl was found to be an effective catalyst for the highly alternating copolymerization of various epoxides and anhydrides.The last part of our investigations refers to the copolymerization of epoxides with CO2 using salphen chromium and especially salphen cobalt complexes. Cobalt catalysts were significantly more active in propylene oxide (PO)/CO2 and cyclohexene oxide (CHO)/CO2 copolymerization compared to their chromium analogues. Highly alternating polycarbonates (> 99%) with low dispersity and molar mass 10-35 kg.mol-1 were prepared by salphen cobalt complexes. Kinetic studies showed that these polymerizations are controlled and MALDI-TOF MS analysis was used for initiation mechanism clarification. Compared to widely investigated salen Co catalysts, salphen Co complexes exhibit lower activity (100-450 h-1) and selectivity to polymer (40-90%) in propylene oxide/CO2 copolymerization, while 100% selectivity to polycarbonate was achieved in the copolymerization of CHO and CO2. Alternatively, new Al, Zn and Mg-based catalysts were tested for CO2 activation, however, they usually led only to epoxide homopolymerization
V této práci byla připravena řada salfenových komplexů na bázi chromu, kobaltu a železa. Tyto komplexy byly použity jako katalyzátory pro kopolymerizace epoxidů s různými substráty: (i) s oxidem uhelnatým (CO), (ii) s anhydridy a (iii) s oxidem uhličitým (CO2). U nových komplexů na bázi zinku, hliníku a hořčíku byla dále testována možnost jejich použití jako katalyzátorů pro kopolymerizace epoxidů s CO2.První část práce se zabývá kopolymerizací epoxidů s oxidem uhelnatým s využitím asymetrického salfenového komplexu na bázi chromu a Co2(CO)8 s cílem připravit kopolymer na bázi přírodního polyhydroxybutyrátu (PHB). Salfenový komplex chromu i Co2(CO)8 vykazovaly velmi nízké aktivity při karbonylaci propylenoxidu a poskytovaly pouze nepatrné množství produktů (cyklického β-butyrolaktonu a PHB). Kombinace obou katalytických komplexů vedla k výraznému zvýšení aktivity ve prospěch cyklického produktu (β-butyrolaktonu) i polymeru. Kopolymerizací PO s CO byl získán pouze nízkomolekulární poly(ester-co-ether), což naznačuje špatnou vzájemnou kompatibilitu těchto komplexů.Druhá část je zaměřena na kopolymerizace epoxidů s anhydridy katalyzované salfenovými komplexy chromu a železa v kombinaci s jednoduchými organickými bázemi. Samotné salfenové komplexy chromu a železa nevedly ke vzniku polymeru. V kombinaci s nukleofilním kokatalyzátorem bis(trifenylfosfin)iminium chloridem (PPNCl) ovšem tyto komplexy poskytly alternující kopolymery epoxidu a anhydridu (polyestery) s molárními hmotnostmi do 10 kg.mol-1 a nízkou dispersitou. Dále bylo zjištěno, že samotné organické báze poskytují podobně jako salfenové komplexy vysoce alternující kopolymery se srovnatelnou molární hmotností i úzkou dispersitou, i když je zapotřebí 5x delších polymerizačních časů. Nejvyšší účinnost ze všech testovaných bází měl PPNCl. Tato báze byla dále efektivně použita pro kopolymerizace řady epoxidů a anhydridů za vzniku vysoce alternujících kopolymerů. Třetí část pojednává o kopolymerizacích epoxidů s CO2 s využitím salfenových komplexů chromu a kobaltu. Bylo zjištěno, že kobaltové komplexy jsou oproti chromovým mnohem efektivnější katalyzátory jak při kopolymerizacích propylenoxidu (PO) s CO2 tak i cyklohexenoxidu (CHO) s CO2. Salfenové komplexy kobaltu poskytly polykarbonáty s vysokým obsahem karbonátových jednotek v kopolymeru (> 99%), úzkou dispersitou a s molárními hmotnostmi 10-35 kg.mol-1. Studie kinetiky odhalila kontrolovaný průběh kopolymerizace. Dále byla provedena MALDI-TOF analýza výsledných polykarbonátů s cílem objasnit mechanismus iniciace kopolymerizace. Ve srovnání se salenovými komplexy kobaltu vykazují salfenové komplexy při kopolymerizacích PO s CO2 nižší aktivitu (100-450 h-1) i selektivitu na polykarbonát (40-90%). Při kopolymerizacích CHO s CO2 byla ovšem selektivita 100%. Nové komplexy na bázi Al, Mg a Zn byly také testovány jako katalyzátory pro kopolymerizace epoxidů s CO2, nicméně jejich aktivita byla nízká a výsledkem těchto reakcí byly pouze polykarbonáty s nízkým podílem karbonátových jednotek nebo polyethery

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34

Whiteley, Jervis. "Complex Adaptive Systems and Conversation Analysis: A New Perspective for Consumer Behaviour Research?" Curtin University of Technology, Graduate School of Business, 2002. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=12936.

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The research question for this study is “Can concepts from complex adaptive systems and conversation analysis be used to research consumer behaviour?" This is, primarily, a theoretical question. After a wide-ranging literature search no scholarly publications linking the qualitative aspects of complex adaptive systems theory to marketing or consumer research were located. In addition, there appear to be few papers on consumer research which use conversation analysis. A theory for the research methodology was developed. It was argued that the production of a research theory and methodology to test the relevance and appropriateness of two very different theories - complex adaptive systems and conversation analysis was the major undertaking of this thesis. The problem of combining an essentially scientific perspective (complex adaptive systems) with an essentially qualitative one (ethnomethodology and conversation analysis) was resolved as part of the research process. A bridging theory was developed through the common ground offered by the sociology of scientific knowledge on the one hand and social-constructionist theory on the other. This methodology was successful in supporting the choice of conversation analysis as the data-collection method and provided the rationale for observing five characteristics of a complex adaptive system. The methodology was tested empirically and, in keeping with exploratory work, iteratively. It is not intended that this type of research will have predictive value. The complex adaptive system studied was consumers in a small group. There were two research locations with six data-collection sessions in each. The first location collected data from organisational groups. The second collected data from groups of consumers convened in a meeting room.
Data were transcribed and analysed for all sessions according to the conventions of conversation analysis. In the meeting-room sessions, data were also collected by electronic-group-support-systems technology and subjected to a modified form of content analysis. The broad findings showed the following. The assumption that there was little evidence of interest in complex adaptive systems among consumer behaviour researchers was confirmed. Apart from one paper calling for the use of conversation analysis in consumer behaviour research, there appeared to have been no subsequent reports of its adoption. The potential for conversation analysis in consumer research has probably not been understood because it was seen as a data-collection method only within an ethnomethodological perspective. The discursive theoretical perspective, which gives a prime position to conversation analysis in the construction of factual accounts, was found to be an innovative way to study consumer behaviour. A discursive theoretical research perspective could have provided a more robust theoretical justification for the fieldwork carried out in this study than the theory of the methodology that was first developed for this study. Conversation analysis did meet the five criteria proposed for surfacing a complex adaptive system in a small group but in an unexpected way. It met these criteria through the research process. In other words, by setting up an appropriate research environment and using conversation analysis, it was shown that a complex adaptive system was in operation.
An outcome of employing complex adaptive systems theory and conversation analysis is a new way of seeing groups of consumers as a self-organised, nonlinear, interactive entity. Conversation analysis has proven to be a method of empirically observing this entity, whilst preserving the consumer groups' complex adaptiveness. There were three conclusions. The first is that the discursive paradigm appears to be an alternative paradigm for consumer behaviour research that is appropriate for certain applications. For example, marketing communications and word-of-mouth communication. The second conclusion is that when small-group talk-in-interaction is recorded and analysed using conversation analysis, the characteristics of a complex adaptive system theorised in this study seem evident to the researcher. The third is that complex adaptive systems appear to be capable of being researched in the field, but more work is needed on defining the characteristics to be researched.

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35

Floquet, Sébastien. "Conversion de spin thermo- et photo-induite de complexes ioniques de fe(iii)." Paris 11, 2001. http://www.theses.fr/2001PA112211.

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Cette etude s'interesse aux conversions de spin thermo et photo-induite de complexes ioniques de fe(iii) et plus particulierement a l'influence de la nature du contre-ion sur les proprietes magnetiques de complexes anioniques et cationiques, celui-ci etant un cation ou un anion usuel, un complexe de charge opposee ou une matrice inorganique. De nouveaux complexes ferriques de thiosemicarbazone ont ete prepares et etudies. Une transition de spin discontinue avec une large hysteresis thermique centree autour de la temperature ambiante a ete caracterisee pour un complexe anionique. Cette propriete est couplee a une transition de phase cristallographique du premier ordre. Pour un complexe neutre de cette famille presentant une hysteresis de 3 k centree a 226 k, nous avons converti partiellement l'etat fondamental bs en un metastable hs par excitation lumineuse a 10 k. Dans cette meme famille, la fonctionalisation du ligand par un groupe styryl photo-isomerisable a permis la synthese de nouveaux complexes anioniques photo-sensibles. Leur irradiation en solution ou en matrice polymerique pmma permet l'isomerisation trans/cis du ligand lie au metal. Des mesures magnetiques realisees sur film mince du complexe mettent en evidence un changement de spin de l'ion metallique (effet ld-lisc). Une nouvelle famille de complexes ferriques cationiques du type fe i i i-catechol a ete egalement etudiee. Les caracteristiques de la transition de spin presentee par ces systemes ont ete modulee par le choix de differents substituants et contre-ions. Elles ont ete analysees a l'aide de donnees rx sur monocristal a temperature variable. Enfin, des complexes cationiques du type fe(r-sal 2trien) + ont ete intercales dans des phases lamellaires cdps 3 et mnps 3. Des equilibres de spin pour les complexes inseres ont ete caracterises. Un materiau d'intercalation dans mnps 3 presente a la fois la propriete de transition de spin du cation intercale et le ferrimagnetisme du reseau d'accueil a t < 36 k.

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Kirchner, Mark William. "A critique of warehouse loft conversions through the adaptive re-use of Western Electric Company complex." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/21759.

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De, Sousa Samuel. "Ingéniérie, synthèse et étude de chromophores organiques et organométalliques pour cellules solaires à colorant." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00952228.

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Le principal objectif de ce travail de thèse était d'imaginer, de synthétiser et de caractériser de nouveaux chromophores "push-pull" pour finalement évaluer leurs propriétés photovoltaïques en cellules solaires à colorant. Deux approches distinctes ont été développées : i) la première consiste en l'élaboration de chromophores tout-organiques de type " push-pull " basés sur un motif électro-donneur carbazole à potentiel d'oxydation élevé. Ces nouveaux colorants ont été conçus dans le but d'être utilisés avec des électrolytes à potentiel standard supérieur à celui du couple rédox I-/I3- ; ii) la seconde approche est basée sur un nouveau concept de chromophores organométalliques de type ruthénium-acétylure. Ces chromophores ont été développés dans le but de combiner à la fois les propriétés avantageuses d'une structure de type " push-pull " et les transferts de charges (MLCT) impliquant le motif [Ru(dppe)2], également connu pour constituer un excellent relai électronique.

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Malone, MaryLauren. "Deception Dynamics: Identifying Patterns of Social Coordination during Truthful and Dishonest Conversation." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491561001412116.

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Congiu, Martina. "Synthesis and characterisation of luminescent lanthanide dyes for solar energy conversion." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7724.

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Lanthanide (III) complexes are used extensively in solar conversion devices, such as Luminescent Solar Concentrators (LSCs) and Luminescent Down-Shifting (LDS) for their peculiar characteristics of narrow band emission, avoidance of re-absorption losses due to large Stokes shift and possibility of high photoluminescence quantum yield (PLQY). The study has looked into the synthesis of Ln (III) complexes of the general formula: [Ln(hfac)3DPEPO], where DPEPO = bis(2-(diphenylphosphino)phenyl)ether oxide, and hfac = hexafluoroacetylacetonate. The work presented in this thesis focuses on the synthesis, and subsequent photophysical characterisation of these Ln(III) complexes, plus characterisation and spectroscopic study of [Tb(pobz)3(hacim)2], (where Hpobz = phenoxybenzoic acid, and Hacim = acetylacetone imine), yielding results that open new design of functional Ln(III) systems. Spectroscopic study of Chromium dioxalate and analogous compounds has revealed that with the appropriate design, Cr(III)Ln(III) energy transfer can be achieved, while study of polyaromatic hydrocarbons (PAH) such as coronene, enable to explore a ligand with better absorption in the whole UV region. These results open attractive perspectives for light-conversion systems, such as LSC devices.

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Monin-Soyer, Hélène. "Complexes à conversion de spin et agrégats métalliques organisés en film de Langmuir-Blodgett." Bordeaux 1, 1998. http://www.theses.fr/1998BOR10635.

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Ce mémoire est consacré à l'obtention et à l'étude de films de Langmuir-Blodgett (LB) magnétiques. Une large partie de ce travail étudie deux complexes amphiphiles de fer (II) à conversion de spin de type FeL₂(NCS)₂, où L est un ligand dérivé de la bipyridine portant soit une chaîne aliphatique, soit une chaîne semi-fluorée. Après synthèse et caractérisation à l'état solide, chaque composé a été organisé le long d’une interface air-liquide. En particulier, l'obtention d'un film de Langmuir stable a nécessité l'utilisation d'une sous-phase partiellement organique pour le complexe à chaîne aliphatique. Après obtention et caractérisation structurale des films LB, la spectroscopie infrarouge a montré que la conversion de spin thermo-induite est conservée dans ce matériau lamellaire ; ceci étant confirmé par mesure directe de magnétisme. L'organisation imposée par la technique LB montre un effet de l'environnement moléculaire qui se traduit par une proportion de molécules susceptibles de changer d'état de spin d'autant plus petite que le matériau est bien organisé. Par fusion des chaînes hydrophobes et perte de la structure lamellaire, la conversion de spin est recouvrée. Ceci a été confirmé par l'étude de films mixtes. Finalement, outre la conversion thermo-induite, la mise en œuvre de l'effet photomagnétique LIESST en milieu organisé a été effectuée. Un autre type de film LB magnétique a attiré notre attention. Des agrégats polymétalliques de manganèse connus pour leurs propriétés magnétiques (en particulier, large boucle d'hystérésis en fonction du champ magnétique externe appliqué) ont pu aussi être organisés en film LB au moyen d'une matrice de molécules amphiphiles. Les études magnétiques entreprises sur ces multicouches montrent la conservation de l'hystérésis magnétique quelle que soit la dilution de l'agrégat dans la matrice.

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41

Xue, Congcong. "The Excited State Properties of Dirhodium (II,II) Complexes: Application for Solar Energy Conversion." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1565632080675563.

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42

Chevalier, Fabienne HeÌleÌ€ne Gabrielle. "To complete or not to complete : a conversation analytic investigation of unfinished turns in French." Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422243.

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43

Bascopé, René Pastor Torrico. "Conversor CC-CC ponte completa ZVS-PWM com comando assimetrico." reponame:Repositório Institucional da UFSC, 1994. https://repositorio.ufsc.br/handle/123456789/111792.

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44

Majewski, Marek B. "Ruthenium(II) complexes bearing polypyridyl ligands with amide bound thienyl groups for photochemical energy conversion." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44478.

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Rousseau, Theodulf. "Elaboration et caractérisation de cellules solaires organiques à base de nouvelles classes de matériaux actifs." Angers, 2011. http://tel.archives-ouvertes.fr/tel-00984367.

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Ce travail porte sur l'élaboration et la caractérisation de cellules solaires organiques à base de nouvelles classes de matériaux donneurs dérivés de petites molécules solubles. Une première phase de ce travail a été consacrée à l'étude des cellules de type hétérojonction volumique à base de poly(3-hexylthiophène) et d'un dérivé soluble du fullerène C60, le PCBM. Le nombre considérable de travaux déjà publiés sur ces dispositifs en ont fait un système modèle particulièrement approprié à l'étude des différents paramètres expérimentaux impliqués dans la fabrication de ce type de cellules et à leur optimisation. Les protocoles expérimentaux définis sur la base de ces études ont été ensuite appliquées à l'évaluation de deux nouvelles classes de donneurs moléculaires à base du dicétopyrrolopyrrole (DPP) et de dipyrrométhène de bore (BODIPY). Les travaux sur les donneurs dérivés du DPP ont porté sur la réalisation de différentes séries de cellules solaires à hétérojonction planaire et volumique et les résultats obtenus ont permis à la fois d'atteindre des performances intéressantes et de progresser dans la compréhension des relations structure-propriétés dans cette famille de donneurs moléculaires. La dernière partie de ce travail concerne la réalisation et l'étude de cellules solaires à partir d'une classe originale de donneurs moléculaires dérivés du BODIPY. La caractérisation des propriétés électroniques de différentes familles de bodipys ainsi que la fabrication et l'étude de plusieurs séries de cellules solaires ont conduit à des avancées importantes et des rendements parmi les plus élevés obtenus jusqu'à présent sur des BHJ moléculaires à base d'accepteur dérivé du C60 ont été obtenus. Par ailleurs ces travaux ont permis de mettre pour la première fois en évidence des effets coopératifs dans des BHJ moléculaires utilisant des donneurs multiples
This work deals with the preparation and characterization of organic solar cells based on novel classes of soluble molecular donors. The first chapter is devoted to the study of bulk heterojunction organic solar cells based on poly(3-hexylthiophene) and a soluble derivative of fullerene C60. This type of device is used as a model system to analyze the various experimental parameters involved in the fabrication and optimization of organic solar cells. The experimental procedures defined on the basis of these studies have been subsequently applied to the evaluation of two classes of molecular donors namely diketopyrrolopyrrole (DPP) and boron dipyrromethene (BODIPY). The work on DPP-based donors involved the fabrication of various series of bilayer and bulk heterojunction solar cells. The results of these investigations have led to interesting performances and to a better understanding of structure-properties relationships in this family of molecular donors. The last part of this work concerned the study and realization of solar cells based on an original class of molecular donors derived from BODIPY. The characterization of the electronic properties of different families of BODIPYs as well as the preparation and study of several series of solar cells have led to important progress, and power conversion efficiencies among the highest reported so far for molecular BHJ solar cells based on soluble C60 derivative have been obtained. Furthermore, first evidences of cooperative effects in molecular BHJ using multiple donors have also been presented

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Lemercier, Gilles. "Préparation, caractérisation et propriétés de complexes du fer (II) avec des ligands polymidazole." Toulouse 3, 1994. http://www.theses.fr/1994TOU30106.

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La premiere partie de ce travail concerne la synthese et l'etude des proprietes de cinq complexes du fer(ii) haut-spin presentant un environnement de ligands de type n#4n#2. Ils sont constitues simultanement du ligand a quatre noyaux imidazole bis(imidazole-4-methyl)-4'-imidazole-2-ylmethane (tim) et de divers carboxylates et nous ont permis d'obtenir de bons modeles structuraux du site ferreux non heme des systemes photosynthetiques. Sur la base de deux resolutions structurales, il a ete possible de mettre en evidence la coordination de l'acetate et du phenylacetate selon un mode bidente non pontant. Les etudes spectroscopiques, magnetiques et structurales de ces complexes et leur comparaison a celles realisees sur les systemes photosynthetiques, permettent de montrer l'importance de la distortion de l'environnement de ligands au regard de la modelisation structurale et spectroscopique. L'utilisation du ligand (imidazole-2-methyl)-2'(imidazole-4''methyl)4' imidazole (trim) a des fins de modelisation, nous a permis de mettre en evidence une nouvelle famille de complexes du fer(ii) caracterises par un environnement de ligands de type n#6 (fe#i#i(trim#2)xy). Ces composes presentent une remarquable diversite de proprietes magnetiques en fonction de la nature des contre-ions x et y, situes hors de la sphere de coordination du metal. Ils sont, pour la plupart, le siege de conversions de spin thermo-induites. L'etude de la variation thermique de la susceptibilite magnetique, des parametres mossbauer, ainsi que la resolution structurale de trois de ces onze complexes, x = y = hco#2#-, cl#- et clo#4#-, nous a permis de: (a) correler la nature des contre-ions a l'etat de spin de certains complexes ; (b) determiner des parametres cinetiques et thermodynamiques et (c) mettre en evidence, a temperature ambiante, la distortion plus importante de la symetrie octaedrique pour les complexes dont le centre fer(ii) est a l'etat haut-spin

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47

Jones, Sumner Weston Jr. "The Synthesis and Photophysical Properties of New Polymetallic Complexes Designed for Use in Photoinitiated Electron Collection." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30459.

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The goal of this research was to develop stereochemically defined multimetallic systems for use as light absorbers and electron donor / light absorber dyads in photoinitiated electron transfer and electron collection. The basis for the stereochemical control was provided by the symmetric bridging ligands 2,3,5,6-tetra(pyridyl)pyrazine (tpp) and 2,2'-bipyrimidine (bpm). The symmetric bidentate ligand 4N-perylene was designed and the majority of the synthesis was completed. The bimetallic complexes [(tpy)M(tpp)Ru(LLL)]²⁺, where M = Ru or Os and LLL = Cl₃, (CH₃CN)₃, tpp, or (dpq)Cl, and the model monometallic complexes [(tpy)M(tpp)]²⁺, where M = Ru or Os, and [(tpy)Ru(CH₃CN)₃]²⁺ were synthesized and characterized using electrochemistry, UV-vis spectroscopy, and UV-vis spectroelectrochemistry. The bimetallic complexes were investigated as potential light-absorber / electron-donor complexes to be used in larger supramolecular devices for photoinitiated electron collection and electron transfer. The electrochemistry showed that the relative energy of the metal orbitals is suitable for the metal in the (tpy)M(tpp) coordination environment to act as an electron donor. These bimetallic complexes possess extremely complicated UV-vis spectroscopy due to the number of possible transitions. The assignment of the UV-vis spectroscopy and the electrochemistry of these complexes was greatly facilitated by the UV-vis spectroelectrochemistry. The metal-to-metal charge transfer spectra of the mixed-valence species of the bimetallic complexes were obtained using NIR spectroelectrochemistry and indicate a significant degree of metal-metal communication through the bridging tpp. The bimetallic complexes [(tpy)Ru(tpp)Ru(tpy)]⁴⁺, [(tpy)Ru(tpp)Ru(tpp)]⁴⁺ [(tpy)Os(tpp)Ru(tpp)]⁴⁺, and [(tpy)Ru(tpp)Ru(CH₃CN)₃]⁴⁺ were found to have emission lifetimes on the order of 100 ns. The complexes [(bpy)₂Ru(bpm)]²⁺, [(bpy)₂Ru(bpm)Ru(bpy)₂]⁴⁺, [(bpm)₂IrCl₂]⁺, and {[(bpy)₂Ru(bpm)]₂IrCl₂}⁵⁺ were synthesized and characterized using electrochemistry, UV-vis spectroscopy, and UV-vis spectroelectrochemistry. The complex {[(bpy)₂Ru(bpm)]₂IrCl₂}⁵⁺ is a LA-EC-LA device for photoinitiated electron collection. The UV-vis spectroelectrochemistry of these complexes facilitated the assignment of the UV-vis spectroscopy as well as the electrochemistry. The UV-vis spectrum of the electrochemically generated two electron reduced form of {[(bpy)₂Ru(bpm)]₂IrCl₂}⁵⁺ was obtained. This spectrum is critical in the understanding of future studies of the photochemically generated two electron reduced species. The symmetric, planar, bidentate bridging ligand 4N-perylene was designed. This ligand would eliminate some of the isomers associated with multimetallic complexes bridged by unsymmetric bidentate bridging ligands. The large π system of 4N-perylene would likely result in a low energy π* orbital compared to dpp, dpq, or bpm. The ligand 4N-perylene would hold bridged metals at a greater distance than 2,2'-bipyrimidine and should facilitate the formation of multimetallic complexes. The synthesis of 1,8-dichloro-2,7-naphthyridine has been completed. 1,8-dichloro-2,7-naphthyridine is a possible reactant in the homo-coupling reaction of a substituted 2,7-naphthyridine to form 4N-perylene. The stereochemically defined molecular systems developed in this work show great promise for use in larger supramolecular complexes designed for photoinitiated electron transfer and electron collection.
Ph. D.

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48

Guo, Wenbin. "Nouveaux composés à conversion de spin et polymorphisme pour une approche multi-échelle vers les hautes T(LIESST)." Thesis, Bordeaux, 2021. http://www.theses.fr/2021BORD0015.

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L'effet LIESST (Light-Induced Excited Spin-State Trapping) apparaît comme l'un des phénomènes les plus prometteurs et les plus excitants pour les dispositifs applicatifs basés sur les complexes à transition de spin (TS). Cependant, la compréhension fondamentale du LIESST doit encore être approfondie avant toute conception rationnelle. Par exemple, il est encore très difficile d'établir les relations structure-propriétés, bien que cette approche soit cruciale pour découvrir des matériaux à TS ayant une température de relaxation T(LIESST) élevée. L'objectif de ce travail est donc de comprendre comment augmenter la valeur de T(LIESST) vers une plage de température de la vie quotidienne. Nous avons choisi de l’atteindre en tentant d’augmenter la distorsion de la sphère de coordination du métal par deux stratégies basées sur la chimie : i) influer à l'échelle moléculaire via des contraintes stériques induites par des ligands halogénés et ii) moduler la contrainte moléculaire via du polymorphisme. La partie I présente quelques aspects fondamentaux et les parties II et III sont consacrées à la synthèse, à la cristallographie et aux études (photo)magnétiques des nouveaux composés moléculaires, y compris des polymorphes, de la famille [Fe(PM-L)2(NCX)2]. Ces nouveaux composés offrent tout d'abord un large éventail de comportements innovants, comme par exemple des expansions volumiques négatives ou nulles à la TS et l'absence de transition à plusieurs étapes malgré des sites métalliques indépendants au sein du cristal. Ces travaux élargissent considérablement la richesse des perspectives du phénomène de TS. De plus, l'examen approfondi des paramètres pertinents pour l’obtention d’un T(LIESST) élevé, tel que discutés dans la partie IV, apporte de nouvelles caractéristiques et prouve définitivement que toutes les échelles physiques doivent être prises en compte, ce qui conduit à proposer un concept multi-échelle de l'effet LIESST
The Light-Induced Excited Spin-State Trapping effect (LIESST) appears as one of the most promising and exciting phenomena for applicative devices based on Spin-CrossOver (SCO) complexes. However, the fundamental understanding of the LIESST effect must be yet deeply completed prior to any rational design of any efficient material. For instance, it is still a great challenge to establish the structure-properties relationships corresponding to the LIESST process, though this approach is crucial to discover SCO materials with a high relaxation temperature T(LIESST). The target of this work is therefore to understand how to increase T(LIESST) towards a daily-life temperature range. We choose to reach this goal by increasing the distortion of the metal coordination sphere through two chemistry-based strategies: i) playing at the molecular scale via steric strains produced by halogen-substituted ligands and ii) controlling the molecular stress through polymorphism. Part I displays some fundamental knowledge on SCO and Part II and III are devoted to the synthesis, crystallography and (photo)magnetic studies of new molecular compounds, including polymorphs, of the [Fe(PM-L)2(NCX)2] family. First these new compounds offer a large panel of innovative behaviours, such as, for instance, negative or zero volume expansions at the SCO and the absence of multi-step transition despite independent metal sites within the crystal. This work enlarges significantly the richness of the SCO based perspectives. Second, the deep examination of the relevant parameters to high T(LIESST) as discussed in Part IV brings new features and, overall, definitively proves that all physical scales must be taken into account, leading to a multiscale concept of the LIESST effect

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Ojelere, Olusola Oyedele [Verfasser]. "Homo- and Heterometallic Complexes of Vanadium and Chromium and their Conversion into Oxide Ceramics / Olusola Oyedele Ojelere." München : Verlag Dr. Hut, 2019. http://d-nb.info/1200754875/34.

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Morais, Aniel Silva de. "Modelagem, controle e implementação de redistribuidor de potência complexa empregando conversor estático e utilizando DSP." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/91548.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-graduação em Engenharia Elétrica, Florianópolis, 2008
Made available in DSpace on 2012-10-24T00:09:22Z (GMT). No. of bitstreams: 1 269698.pdf: 12328318 bytes, checksum: 2e6382c526f45e2b8344365d85393c6d (MD5)
Projeto e implementação de um conversor estático a quatro fios para equilibrar a potência complexa entre as fases do sistema de energia elétrica, melhorando os índices de qualidade para o consumidor e reduzindo custos para a concessionária de energia elétrica relativo a sistemas de distribuição. A modelagem e o controle do conversor foram desenvolvidos na base dq0. Um DSP TMS320F2812 foi utilizado para controlar digitalmente o conversor. A freqüência de chaveamento é de 20kHz e a freqüência de amostragem de 40kHz. Um protótipo de 17,86kVA foi ensaiado em laboratório, processando 11,26kVA para redistribuir a potência complexa de três cargas monofásicas distintas e conectadas em estrela com neutro, uma carga resistiva, uma indutiva e um retificador monofásico.
Design and implementation of a four-wire converter to balance the complex power among the phases of the electric power system, improving quality indexes for the consumer and reducing the costs of the electric energy dealer regarding distribution systems. Modeling and control of the converter were developed in the dq0 base. A DSP TMS320F2812 was used to implement the control of the converter. The switching frequency is 20kHz and the sampling frequency is about 40kHz. A prototype of 17,86kVA was built, processing 11,26kVA to redistribute the complex power of three different single phase loads connected in star with neutral, a resistive load, an inductive one and a single phase rectifier.

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Dissertations / Theses on the topic 'Complex conversion'

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