Dissertations / Theses on the topic 'Radical'
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Grice, I. Darren, and n/a. "Some New Aspects of Radical Trapping Using an Aminoxyl Radical Trap." Griffith University. School of Science, 1993. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050915.150556.
Full textGrice, I. Darren. "Some New Aspects of Radical Trapping Using an Aminoxyl Radical Trap." Thesis, Griffith University, 1993. http://hdl.handle.net/10072/365216.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Science
Science, Environment, Engineering and Technology
Full Text
Shergill, Raminder. "Radicals and radical pairs in chemical and biological systems." Thesis, University of Leicester, 2010. http://hdl.handle.net/2381/11008.
Full textBarrera, Mora Jose Felix Fernando. "On radical extensions and radical towers." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184833.
Full textFabbri, Claudia. "Mechanistic aspects of lignin degradation. Role of radicals and radical ions." Doctoral thesis, La Sapienza, 2005. http://hdl.handle.net/11573/917334.
Full textIshaq, Ahtsham. "The development and use of novel green radical methodology." Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=158370.
Full textMcGarry, Peter F. "Radical and radical-like reactions of (1.1.1);propellane." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7811.
Full textBotelho, João Francisco. "Epigênese radical." Florianópolis, SC, 2007. http://repositorio.ufsc.br/xmlui/handle/123456789/89646.
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Existe na biologia contemporânea um consenso de que a genética proporcionou uma solução conciliatória para o longo debate entre preformacionistas e epigenesistas. O desenvolvimento, segundo a genética, é um processo híbrido de preformação e epigênese. A preformação persiste como informação, como um programa codificado do desenvolvimento. A epigênese persiste como a tradução do programa genético, como a revelação da informação pela expressão gênica. O presente trabalho critica esta conciliação genética a partir de duas análises epistemológicas # uma histórica e a outra conceitual # e defende uma posição alternativa # a Perspectiva dos Sistemas Desenvolvimentais (PSD). A análise histórica consiste em mostrar que o conceito de preformação é mais amplo e plástico do que a simples idéia de preexistência e pré-delineação de um organismo completo. O conceito de preformação chega ao século XX associado ao conceito de unidades hereditárias determinantes do desenvolvimento e está historicamente associado à tradição de pesquisa genética. A análise conceitual consiste em mostrar que a biologia contemporânea desautoriza o discurso preformacionista contido nas idéias de herança como transmissão genética, primazia e independência causal dos genes, herança sólida e programa genético. No lugar da conciliação genética defendo uma perspectiva estritamente epigenética dos processos celulares e desenvolvimentais como proposta pela PSD. There is a consensus in contemporary biology that genetics provided a conciliatory solution for the long-standing debate between preformationists and epigenesists. Development, according to the genetic conciliation, is a hybrid process of preformation and epigenesis. Preformation persists as information, as a codified program of development. Epigenesis persists as the translation of the genetic program, as the revelation of genetic information. The present thesis criticizes this genetic conciliation from two epistemological points of view # a historical one and a conceptual one # and supports an alternative position: the Developmental Systems Perspective (DSP). The historical analysis shows that the preformation tradition is wider than the simple idea of preexistence and pre-delineation of form. The preformation tradition arrives at the 20th century associated to the concept of units of inheritance controlling development and it is historically associated with the research tradition of genetics. The conceptual analysis consists of showing that contemporary biology discourages the preformationists assumptions enclosed in the ideas of heredity as genetic transmission, causal priority of the genes, exclusively genetic inheritance and genetic program. In the place of the genetic conciliation, we defend a strict epigenetic view of cellular and developmental processes, coherent with the DSP.
Qureshi, Tariq. "Spin chemistry." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365292.
Full textWood, Geoffrey Paul Farra. "Theoretical Investigations of Radical-Mediated Protein Oxidation." Thesis, The University of Sydney, 2006. http://hdl.handle.net/2123/1413.
Full textWood, Geoffrey Paul Farra. "Theoretical Investigations of Radical-Mediated Protein Oxidation." University of Sydney, 2006. http://hdl.handle.net/2123/1413.
Full textThis thesis primarily details the application of high-level ab initio quantum chemistry techniques in order to understand aspects of free-radical mediated protein oxidation. Traditionally, product analysis and electron paramagnetic resonance (EPR) spectroscopy are the primary means for elucidating the chemistry of protein oxidation. However, in experiments involving relatively small proteins reacting with a controlled radical-flux, a vast array of compounds can be produced, which are often difficult to analyse. Quantum chemical techniques on the other hand, can calculate the properties of any particular species directly, without suffering from the problems associated with experiment, such as side-reactions and chain processes. The results presented in this thesis are aimed at elucidating mechanistic details of protein oxidation, which might otherwise be difficult to probe experimentally. Chapter 1 gives an overview of the free-radical hypothesis of disease and ageing. Protein-derived radicals can undergo a variety of reactions, with the particular reaction that occurs depending on numerous aspects. Many types of reactions have been identified through radiolysis experiments of amino acids, and these are detailed in this chapter. In addition, the key reactive species are characterized and their different chemistries explained. Chapter 2 details the theoretical tools used throughout this thesis. Species with unpaired electrons (radicals) present unique problems for quantum chemistry to handle, thus an appropriate choice of theoretical technique is needed. The approach taken in this thesis is to use high-level compound methods, many of which have been directly formulated to give improved results for radical species, to provide benchmark quality results by which other less demanding techniques can be assessed. During the course of this study, it became apparent there was a void in the armoury of tools that could be used for the theoretical chemistry calculations. Chapter 3 details the formulation of a new tool in an attempt to fill this gap. Historically, the formulation of this new procedure came after much of the work in this thesis had been carried out. Thus, for the study of many of the reactions of this thesis the new method has not been used. However, it is most appropriate to place its formulation after summarizing the current status of techniques in common use today. Chapters 4 and 5 detail computations carried out on models of peptides containing backbone carbon- and nitrogen-centered radicals. A number of different theoretical techniques are used in these chapters, ranging from the highly accurate and computationally intensive to the less reliable and less demanding. The highly accurate techniques are used to gauge the accuracy of the other less demanding theoretical techniques so that the latter can be used with confidence in larger systems. Not only is the choice of theoretical technique important but also the judicious choice of model is essential. With this in mind, models are incrementally built until convergence of the particular property of interest is reached. Chapters 6 and 7 detail the calculations of β-scission reactions of alkoxyl radicals, which are a particular class of reaction known to occur on peptide backbones. Alkoxyl radicals are particularly difficult for theory to describe correctly. Therefore, Chapter 6 extensively assesses and then identifies the theoretical methods needed to portray them. Chapter 7 uses the techniques identified in the previous chapter in order to predict how the preference for a particular type of β-scission reaction changes.
Belincanta, Juliana. "Homopolimerização e copolimerização via radical livre controlada por radicais nitroxidos." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266269.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: A polimerização viva/controlada é uma área que vem se desenvolvendo rapidamente no escopo de polímeros e engenharia. A habilidade para preparar copolímeros bem definidos do tipo bloco, estrela, redes poliméricas, bem como outros materiais pelo mecanismo da polimerização via radical livre é talvez a principal razão para o crescente interesse pela academia cientifica e meio industrial neste tipo de polimerização viva/controlada. O interesse industrial se deve a aplicabilidade desta nova técnica em áreas como colas, adesivos, surfactantes, dispersantes, lubrificantes, gel, aditivos, elastômeros termoplásticos, bem como aplicações nas áreas de eletrônica e biomedicina. Vale citar a produção industrial de dispersantes pela polimerização mediada por nitróxidos, um caso de polimerização viva/controlada. Este trabalho tem como objetivo investigar experimentalmente e por modelagem a polimerização em massa via radical livre mediada por TEMPO (2,2,6,6-tetramethyl piperidinyl-1-oxy) de estireno e estireno com divinilbenzeno, sob diversas condições experimentais. Para o caso de homopolimerização foi avaliada uma análise de sensibilidade de como as constantes cinéticas afetam o desempenho do modelo. Reações, não incluídas no modelo original, foram adicionadas ao modelo e testadas. O efeito de diferentes concentrações de TEMPO foi avaliado experimentalmente. Foi observado que esta condição afeta significativamente os resultados. Para o caso de copolimerização, resultados experimentais foram obtidos em diversas temperaturas, e concentração inicial de DVB (divinilbenzeno) e TEMPO. O gel obtido pela polimerização mediada por TEMPO apresenta diferenças marcantes daquele preparado pelo sistema convencional, com relação ao perfil de conversão de monômero. O ponto gel para este caso novo foi obtido em tempos maiores daquele obtido em sistemas convencionais. A versatilidade da polimerização mediada por nitróxidos permite a síntese de um número significativo de novas arquiteturas poliméricas. Espera-se que o modelo proposto, bem como os dados experimentais obtidos neste trabalho, seja útil para um melhor conhecimento desta nova técnica de polimerização. Palavras-chave: polimerização viva/controlada, TEMPO, polimerização em massa, experimental, modelagem
Abstract: Controlled/living radical polymerization (CLRP) is one of the most rapidly developing areas of polymer science and engineering. The ability to prepare well-defined block and graft copolymers, gradient and periodic copolymers, stars, combs, polymer networks, end-functional polymers and many other materials by free-radical mechanisms is perhaps the main reason for the increased academic and industrial interest in CLRP. The industrial interest is triggered by the potential of CLRP in areas as coatings, adhesives, surfactants, dispersants, lubricants, gels, additives, thermoplastic elastomers as well as many electronic and biomedical applications. It is pointed out the industrial production of dispersants by nitroxide-mediated radical polymerization (NMRP), one case of CLRP. This study focus on the model and experimental investigation of TEMPO (2,2,6,6-tetramethyl piperidinyl-1-oxy) mediated free radical polymerization of styrene and styrene-co-divinylbenzene carried out in bulk under different experimental conditions. For homopolymerization case, a sensitivity analyses of how kinetic constants affect the model performance was carried out. Other reactions, not included in the previous model, were included and tested. The effect of different initial concentration of TEMPO was evaluated experimentally. It was shown that this condition affects significantly the results. For copolymerization case, experimental results were obtained for different temperature, and initial concentration of DVB and TEMPO. The gel prepared by NMRP showed remarkable differences from the one prepared in the conventional system, in regard to the monomer conversion profile. The gel point was delayed for the new process compared with conventional systems. The versatility of NMRP permits the synthesis of a number of novel architectures. In conclusion, the model proposed is expected to provide useful guidelines towards a better understanding of the NMRP process. Keywords: controlled/living polymerization, TEMPO, bulk polymerization, experimental, model
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química
Linares, Edlaine. "Papel do peroxinitrito na atividade leishmanicida de macrófagos em modelos murinos." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-06112008-143840/.
Full textMacrophage oxidative microbicidal mechanisms remain debatable and their elucidation is likely to depend on studies with mammalian hosts. To examine macrophage microbicidal mechanisms in vivo, we compared infection parameters in the lesions of resistant (C57Bl/6) and susceptible (BALB/c) mice to the protozoan Leishmania amazonensis. This comparison demonstrated that infection control by resistant mice relied on macrophage activation with inducible nitric oxide synthase expression, nitric oxide synthesis and extensive nitration and hydroxylation of the proteins of the parasites inside macrophage phagolysosomes. The toxic agent to the parasite is likely to be peroxynitrite-derived because parasite nitration occurred in the virtual absence of polymorphonuclear cells and was accompanied by parasite hydroxylation. In addition, tempol, an inhibitor of peroxynitrite-mediated nitrations, inhibited protein nitration of the lesions and increased the number of parasites in them. Also, studies with parasite cultures confmed that peroxynitrite is cytotoxic to the parasites whereas nitric oxide is cytostatic. The susceptible mice were also able to synthesize nitric oxide but only at late infection time and, most likely, in response to a secondary bacterial infection. Taken together, the results indicate that peroxynitrite and derived radicals are the main leishrnanicidal agents produced by macrophages in vivo.
Clark, Jared M. "The Formation and Stability of Radical-Molecule and Radical-Radical Complexes and Their Importance in Atmospheric Processes." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2679.
Full textPIACENTINI, FRANCESCO. "AM I RADICAL, RIGHT? THE RADICAL RIGHT FAMILY IDEOLOGICAL OUTLOOK AND RADICAL RIGHT ATTITUDE AMONG THE PUBLIC." Doctoral thesis, Università degli Studi di Milano, 2022. https://hdl.handle.net/2434/945096.
Full textFraser, M. A. "Radical protagonists : A study of radical periodicals in the 1790s." Thesis, University of Exeter, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377791.
Full textBarry, Justin. "The Solvent Cage Effect: Using Microviscosity to Predict the Recombination Efficiency of Geminate Radicals Formed by the Photolysis of the Mo-Mo Bond of Cpʹ2Mo2(CO)6." Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23713.
Full textKing-Ries, Kristin Marie. "The Heart Radical." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-01132009-124617/.
Full textGreen, Stuart P. "Biomimetic radical reactions." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357914.
Full textWalkington, Andrew J. "Biomimetic radical cyclisations." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280293.
Full textKilgour, Christopher Edward. "Radical convolution algebras." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319998.
Full textDowney, Adrian. "Radical sensorimotor enactivism." Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/67116/.
Full textGonçalves, Maria Cecilia. "Estudo experimental da polimerização via radical livre controlada em presença de radicais nitroxido (NMRP)." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266346.
Full textDissertação (mestrado) - Universidade Estadual de Campinas. Faculdade de Engenharia Quimica
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Resumo: A polimerização via radical livre controlada mediante radicais nitróxido (NMRP) tem recebido cada vez mais atenção como uma técnica para produção de polímeros com estrutura altamente controlada. Distribuições de pesos moleculares estreitas são obtidas, com polidispersidades baixas. Neste trabalho, será estudado o processo NMRP, no qual ocorre a adição de um radical nitróxido estável, como o 2,2,6,6-tetrametil-l-piperidinoxil (TEMPO) para capturar o radical em crescimento. Embora o processo NMRP de ao polímero características controladas (polidipersidades baixas e pesos moleculares que aumentam linearmente com a conversão), ainda existe um desafio nos processos controlados, por apresentarem baixas velocidades de reação. O objetivo principal deste trabalho está focado num estudo experimental do processo NMRP visando aumentar a velocidade de reação sem perder as características principais do processo. O efeito de dois iniciadores BPO (peróxido de benzoíla) e TBEC (tert-butilperóxido-2-etilhexil carbonato) foi analisado. Observou-se que o TBEC (iniciador com constante de decomposição baixa) foi capaz de aumentar significativamente a taxa de polimerização do processo NMRP, quando comparado ao BPO, pois conversões mais altas foram obtidas, num mesmo tempo de reação, mantendo a característica controlada do sistema. O uso do TBEC apresenta uma vantagem frente ao BPO em processos controlados, não somente porque reduz o tempo de reação, mas também porque concentrações menores de iniciador e controlador foram usadas, obtendo uma taxa de reação ainda maior, o que reduz o custo operacional. Para as condições estudadas, comprovou-se experimentalmente que a taxa de reação é inversamente proporcional à concentração inicial de TEMPO, para uma mesma concentração de iniciador. A análise dos resultados através da aplicação da técnica de planejamento de experimento auxiliou numa melhor compreensão do sistema e na obtenção de condições ótimas de operação para se obter baixas polidispersidades e baixos tempos de polimerização
Abstract: NMRP process (Nitroxide Mediated Radical Polymerization) has received increasing attention as a technique for production polymers with highly controlled structures, narrow molecular weight distribution (MWD) and polydispersity index dose to 1.0. In this work 2,2,6,6-tetramethyl-l-piperidinoxyl (TEMPO) is used as the stable radical to reversibly terminate the growing polymer chain. Polymerizations were performed in ampoules, using TBEC (tert-butylperoxy-2-ethylhexyl carbonate) and BPO (benzoyl peroxide) as initiators. With the purpose of enhancing the reaction rate for NMRP process maintaining the controlled and living characteristics of the polymer synthesized (low polidispersity and molecular weights increasing linearly with conversion) an experimental study was done to evaluate the effect of two different initiators (BPO and TBEC). It was observed that TBEC (initiator with low decomposition rate) was able to enhance significant1y the polymerization rate compared to BPO, keeping the living and controlled characteristics of the system. The results show that TBEC seems to be a promising initiator that make the NMRP process more efficient, not only because it reduces the polymerization time, but also because it allows smaller amounts of controller and initiator to be used. For the operational conditions studied, experimental results with TBEC exposed that the polymerization rate in inversely proportional to the initial concentration of TEMPO, for the same amount of initiator. Using a statistical planning, it was possible to obtain a better understanding of the system and to search for operating conditions that bring low polydispersity and low reaction rates. Finally, the results are expected to have significant benefits for controlled polymerization on an industrial setting
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
Capdevila, i. Cortada Marçal. "Long, Multicenter Bonding Present in Radical-Radical Interactions: A Computational Study." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/277254.
Full textLa següent tesi s’emmarca dins l’estudi dels enllaços multicentre a llarga distància entre radicals orgànics. Aquests enllaços varen ser observats per primer cop a finals dels anys 60, però no fou fins al 2001 quan, a través d’un estudi teòric-experimental, es caracteritzaren. Els enllaços multicentre a llarga distància s’originen entre radicals orgànics a distàncies força majors que els enllaços covalents, però inferiors a distàncies de van der Waals (típicament, el dímer pi[TCNE](2)(2-) té una distància d’equilibri de 2.89 Å). En la seva distància d’equilibri, els orbitals SOMO dels radicals se solapen i combinen formant una combinació enllaçant doblement ocupada (l’HOMO) i una combinació antienllaçant desocupada (el LUMO), resultant-ne un dímer diamagnètic. El treball realitzat en aquesta tesi es divideix en dues parts, l’estudi fonamental dels enllaços multicentre a llarga distància i l’estudi d’aquest fenomen a temperatura ambient. En la primera part, es realitza un extens estudi metodològic de quatre dímers que presenten aquest tipus d’enllaç, pi-[TCNE] (2)(2)-, pi-[TCNB] (2)(2-), pi-TCNP] (2)(2-) i pi-[TTF] (2)(2+), pels quals es calibren diversos espais actius i fins a 23 funcionals de la densitat. A més a més, es realitza un estudi del dímer de pi-[TCNE] (2)(2-) en fase condensada, on s’obtenen dades de la seva solvatació i del seu comportament a diferents temperatures. També es fa un estudi en estat sòlid dels dímers pi-[TCNB] (2)(2-) i pi-[TCNP] (2)(2-), on es compara la naturalesa de la seva interacció en fase gas i estat sòlid i s’estudia la seva orientació relativa. Finalment s’han estudiat les quatre formes polimòrfiques del cristall de [TTF][TCNE], on s’ha caracteritzat l’enllaç a llarga distància entre pi-[TTF•••TCNE]. En la segona part, certs exemples de les dues famílies de compostos que exhibeixen enllaços multicentre a llarga distància a temperatura ambient han estat estudiades. Aquestes dues famílies són els oligòmers de donadors o acceptors i els agregats supramoleculars. Un oligòmer de tiofè, l’oligotienoacè (anells de tiofè fusionats) de set membres, ha estat estudiat. S’ha avaluat l’impacte de substituents laterals, així com l’efecte de la solvatació i de tenir un excés de contraions en la dissolució. De la segona família de compostos s’ha estudiat la inclusió d’un dímer pi-[TTF] (2)(2+) dins la cavitat d’un macrocicle cucurbit[8]uril, així com la dimerització de clips moleculars que contenen TTF i un compost mecànicament entrellaçat [3]catenan el qual conté TTF en els macrocicles exteriors.
Zhu, Hai. "Construction of carbo- and oxacycles using radical relay cyclizations initiated by alkoxy radicals." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44759.
Full textFriedline, Robert Alan. "The Reaction Kinetics of Neutral Free Radicals and Radical Ions Studied by Laser Flash Photolysis." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/11157.
Full textPh. D.
Mathews, M. R. "The personal and professional development of a radical non-radical : an overview." Thesis, University of South Wales, 2006. https://pure.southwales.ac.uk/en/studentthesis/the-personal-and-professional-development-of-a-radical-nonradical(790ffc11-4aca-4540-9dfd-4060911e1720).html.
Full textMitroka, Susan M. "Modulation of Hydroxyl Radical Reactivity and Radical Degradation of High Density Polyethylene." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77137.
Full textPh. D.
Grau, Etienne. "Polymerization of ethylene : from free radical homopolymerization to hybrid radical / catalytic copolymerization." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10242/document.
Full textThis work aims to study ethylene polymerization from the free radical polymerization process to the copolymerization by a hybrid radical/catalytic mechanism. PE is synthesized by free radical polymerization under milder experimental conditions than industrial ones (P>1000 bar and T>100°C). Indeed free radical polymerization of ethylene is efficient even down to pressure of 5 bar and temperature of 10°C. Several unexpected behaviors are observed such as a high solvent activation effect. Beside the slurry process in organic solvent, polymerization in aqueous dispersed media is also performed. Stable PE latexes are obtained with solid contents up to 40%. Two different PE particles morphologies are observed cylinder-like and sphere-like. Then free radical copolymerization is studied using a broad range of polar vinyl monomers in organic solvent and emulsion. Insertions up to 50% of ethylene are obtained under mild conditions. The ambivalent role of comonomer as monomer and activator of the polymerization is highlighted. In order to obtain a wide range of composition of polar/non-polar copolymers a new technique of polymerization has been developed. A nickel complex is used to initiate the free radical polymerization and to catalyse the coordination/insertion ethylene polymerization. This nickel complex is capable of a reversible homolytic cleavage of its nickel-carbon bond. Finally, this hybrid process is used to copolymerize efficiently ethylene with various polar vinyl monomers. Multiblock copolymers with ethylene content from 1% to 99% are obtained by simply varying the monomer feeds
Rosero, Mesa Paola Viviana. "Modelagem da homopolimerização via radical livre controlada em presença de radicais nitroxido." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267475.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Neste trabalho foi desenvolvido um modelo matemático para a polimerização via radical livre controlada em presença de radicais nitróxidos (NMRP), que inclui a obtenção dos pesos moleculares médios e o índice de polidispersidade para polímeros de estrutura linear. Por ser a polimerização via radical livre (FRP) uma das polimerizações mais estudadas, este trabalho contemplou o estudo do processo FRP em sistemas homogêneos como base para a modelagem da polimerização via radical livre controlada (LFRP). A LFRP se destaca por ser capaz de obter polímeros com polidispersidade perto de 1,0 e distribuições de peso molecular estreitas. Existem diferentes mecanismos LFRP, dos quais se destaca o mecanismo NMRP, o qual consegue obter polímero com peso molecular controlado mediante a adição de um radical nitróxido à polimerização via radical livre, gerando uma reação reversível capaz de bloquear as cadeias em crescimento. Para obtenção dos pesos moleculares médios e a distribuição do peso molecular (MWD) no processo FRP, foram utilizados o método instantâneo e o método dos momentos; já no novo processo (NMRP) foi usado o método dos momentos para a obtenção dos pesos moleculares médios e o índice de polidispersidade. O modelo matemático foi baseado nas constantes cinéticas de taxa e na teoria do volume livre para o processo FRP e nas constantes cinéticas no processo NMRP. Os resultados foram comparados com dados experimentais para avaliar o modelo. Como casos estudo foram analisadas as polimerizações de estireno e de metilmetacrilato para o processo FRP e as polimerizações de estireno no processo NMRP. Os resultados de validação obtidos mostraram que o modelo sugerido é capaz de modelar o processo monomolecular e bimolecular NMRP a diferentes condições de temperatura e concentração de espécies. Os resultados do modelo também mostraram como no processo NMRP, a espécie polimérica morta surge de radicais poliméricos que não conseguem ser capturados no processo. Foi mostrado como radicais nitróxidos menos estáveis geram resultados mais favoráveis em termos de produtividade e qualidade de produto
Abstract: A practical methodology for the computer modeling of number-and weight-averages molecular weight and molecular weight distribution of polymer with linear structure obtained from nitroxide mediated radical polymerization (NMRP) has been developed. Since free-radical polymerization (FRP) is one of the most important chain-growth polymerization, this work embraces a free-radical polymerization in homogeneous systems as reference point to model the "Iiving" free-radical polymerization. The "living" free-radical polymerization (LFRP) emphasizes the production of polymers with highly controlled structures, narrows MWD and polydispersity index closed to 1.0. Different mechanisms have been proposed to carry out LFRP, among them, Nitroxide-mediated radical po/ymerization (NMRP), which attains polymers with controlled molecular weight by mediated nitroxide radicais acting as trapping agent, in which the polymer chain that is growing are reversibly trapped. To obtain number- and weight-averages molecular weight and molecular weight distributions (MWD) for FRP process the instantaneous and moments methods were used. On the other hand, for the process NMRP the method of moments was used to obtain the number- and weight-averages molecular weight and polydispersity index. The mathematical model was based on kinetics constant rates and free-volume theory for FRP and kinetics constant rates for NMRP. Simulations were compared with experimental data to validate the model. Styrene and methylmethacrilate was analyzed as cases studies for FRP process and styrene polymerization for NMRP process. The model was able to modeling monomolecular and bimolecular NMRP process to different conditions of temperature and species concentrations. It showed the dead polymer chain appear by live polymeric chain not captured by nitroxide radicais in the NMRP processo. Then, NMRP can obtain "Iiving" characteristic if exists enough quantity of nitroxide radical. This permits the radicais created to be captured. Nitroxide radicais more unstable generate best results in relation to productivity and product quality
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Mestre em Engenharia Química
Thunholm, Mattias, and Marcus Boström. "Radical Hotel : En affärsplan." Thesis, University of Kalmar, Baltic Business School, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hik:diva-257.
Full textVi åsyftar att undersöka möjligheterna att starta upp och driva det mindre hotellet. Vi vill med denna affärsplan undersöka marknaden och upptäcka eventuella brister i idén före den blir verklighet.
Frågeställning: Hur etableras och drivs det mindre hotellet på ett framgångsrikt sätt?
Vi har gjort en kvalitativ fallstudie på tre hotellföretag och använts oss av semi-strukturerade intervjuer med berörda personer på de tre olika hotellen. Teorin har insamlats genom relevant litteratur inom ekonomi och marknadsföring samt via elektroniska källor.
Vi har visat på att det finns goda möjligheter att skapa en hotellverksamhet i en stad som Göteborg. Dock under vissa förutsättningar; att vi får tag i en lokal som passar våra behov samt att vi får en omsättningsbaserad hyra så vi slipper tunga investeringskostnader.
Gravelle, Kristian G. "Radical cyclizations of hydrazones." Thesis, University of Ottawa (Canada), 1997. http://hdl.handle.net/10393/9806.
Full textLopes, Carlos Eduardo. "Behaviorismo radical e subjetividade." Universidade Federal de São Carlos, 2006. https://repositorio.ufscar.br/handle/ufscar/4813.
Full textUniversidade Federal de Minas Gerais
In radical behaviorism, subjectivity is studied, generally speaking, in terms of the theory of private events. The theory of private events has its roots in the problem of accessibility in the thesis, that is, that a person has privileged access to certain events that occur under his skin (privacy). If we examine the origins of this thesis, we will find that it reaches radical behaviorism via the paths of dualism and logical positivism (through methodological behaviorism). However, if we interpret radical behaviorism on the basis of a relational metaphysics, the influence of dualism and logical positivism can be overlooked. This opens the possibility that radical behaviorism can do without the theory of private events. Nevertheless, if we abandon the theory of private events, what will be the consequence for of the study of subjectivity? The main objective of this work is to answer this question. Here, we uphold the thesis that the study of subjectivity in radical behaviorism, without reference to the theory of private events, can be fruitfully pursued. This can be achieved through the concepts of body and world , and through the construction of a theory of the self compatible with radical behaviorism. Thus, this work seeks to offer an interpretation of radical behaviorism, based on a relational metaphysics, which separates subjectivity from privacy. This interpretation also considers the possibility of productive dialogues between radical behaviorism and other psychological and philosophical theories (such as James psychology, Gestalttheorie , and analytic philosophy). According to this interpretation, subjectivity is related to the products of discriminative verbal behavior (identified as the I). As this product depends on a verbal community (which arranges discriminative contingencies), subjectivity comes to be considered social. Moreover, the person-verbal community interface renders the defense of a pure subjectivity not viable, as well as that of an unmitigated objectivism. Because of this, radical behaviorism may be capable of deconstructing the objective-subjective debate: these terms are subordinated to the relation of behavior. It is concluded that the radical character of radical behaviorism is not due to its dealing with private events, but to the study of behavior without resorting to non-behavioral instances.
No behaviorismo radical a subjetividade é estudada, geralmente, recorrendo-se à teoria de eventos privados. A teoria de eventos privados tem em sua raiz a problemática da acessibilidade , ou seja, a tese de que a pessoa tem acesso privilegiado a determinados eventos que ocorrem sob sua pele (privacidade). Analisando a origem dessa tese encontraremos que ela chega ao behaviorismo radical pela via do dualismo e do positivismo lógico (através do behaviorismo metodológico). No entanto, quando se interpreta o behaviorismo radical a partir de uma metafísica relacional, elimina-se a influência tanto do dualismo, quanto do positivismo lógico. Com isso, o behaviorismo radical pode abandonar a teoria de eventos privados. Mas diante dessa possibilidade como ficaria o estudo da subjetividade? Responder a essa questão é o principal objetivo deste trabalho. Defende-se, aqui, a tese de que é viável empreender um estudo da subjetividade no behaviorismo radical desvinculado da teoria de eventos privados. Isso pode ser feito através dos conceitos de corpo e mundo, e da construção de uma teoria do self compatível com o behaviorismo radical. Dessa forma, o presente trabalho busca apresentar uma interpretação do behaviorismo radical, pautada em uma metafísica relacional, que desvincula subjetividade de privacidade. Essa interpretação considera também a possibilidade de diálogos produtivos entre o behaviorismo radical e outras teorias psicológicas e filosóficas (tais como psicologia jamesiana, Gestalttheorie e filosofia analítica). De acordo com essa interpretação, subjetividade está relacionada com os produtos do comportamento verbal discriminativo (que se identifica com o eu). Como esse produto depende de uma comunidade verbal (que arranja contingências discriminativas) a subjetividade passa a ser considerada social. Além disso, a interface pessoa-comunidade verbal torna inviável a defesa de uma subjetividade pura, bem como de um objetivismo pleno. Com isso, o behaviorismo radical parece ser capaz de desconstruir o debate subjetivo-objetivo: esses termos estão subordinados à relação comportamental. Por fim, conclui-se que a radicalidade do behaviorismo radical não está em considerar os eventos privados em sua explicação do comportamento, mas em estudar o comportamento sem recorrer a instâncias não-comportamentais.
Gravelle, Kristian. "Radical cyclizations of hydrazones." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq20975.pdf.
Full textSmil, David V. "Boron tethered radical cyclizations." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0006/MQ40735.pdf.
Full textDing, Shijie. "Atom transfer radical polymerization." Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1225138911&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Full textColl, Mármol Jesús. "Interpretación radical y escepticismo." Doctoral thesis, Universidad de Murcia, 2006. http://hdl.handle.net/10803/10822.
Full textThis work examines whether it follows a refutation of scepticism from Donald Davidson's work on radical interpretation. It is argued that such a conclusion does not follow from Donald Davidson's views on thought and language, not even with the help of the so called omniscient interpreter argument. This work also rejects that such views on language and thought lead to a better result against scepticism when interpreted as a modest transcendental argument. Finally it is claimed that the best way of articulating Davidson's antisceptical strategy is as a theoretical diagnosis of scepticism in a similar vein as Michael Williams has developed in his book Unnatural Doubts. From this point of view what Davidson's philosophy would do is, on the one hand, to reproach the sceptic his adherence to representationism and, on the other hand, to defend an alternative to this philosophical view that explains how thought and language are possible. Conceived of in this way, Davidson's philosophy would not constitute a definitive victory against scepticism. However it would show that scepticism is not compulsory and, at the very least, it would guarantee a presumption of innocence for our beliefs when they face the sceptical threat.
Carter, A. "Marx : A radical critique." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375882.
Full textBarreto, Joao Pedro Cabaco Moniz. "Dioxygen free radical reactions." Thesis, Oxford Brookes University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389105.
Full textWinning, Leonard H. "New Radical Cascade Chemistry." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494312.
Full textGladwin, Amanda R. "Radical cascades in synthesis." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336947.
Full textPatterson, Christopher William. "Radical fragmentation of oxiranes." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329877.
Full textEuapermkiati, Anucha. "Free radical telomerisation reactions." Thesis, University of Bradford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278895.
Full textShooter, Andrew James. "Living free radical polymerisation." Thesis, University of Warwick, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263817.
Full textBrown, David William. "Radical additions to butenolides." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360719.
Full textWilmshurst, Martin Philip. "Fluoroalkyl radical cyclisation reactions." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286192.
Full textAldabbagh, Fawaz. "Radical cyclisations onto imidazoles." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/32471.
Full textMcCallum, Terry. "Radical Adventures in Photochemistry." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37825.
Full textVega, Hernández Karen de la. "Radical Germylzincation of Alkynes." Thesis, Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=http://theses-intra.upmc.fr/modules/resources/download/theses/2019SORUS072.pdf.
Full textThe development of a general radical approach for the germylzincation of alkynes as a straightforward route for the preparation of polysubstituted vinylgermanes was the central axis of this work. Within this project, we disclosed that the regio- and stereoselective addition of germanium and zinc across the C‒C triple bond of terminal and internal ynamides was achieved by reaction with a combination of a hydrogermane and diethylzinc in a radical chain process. The key feature of this new approach was the possibility of using the C(sp2)‒Zn bond created as linchpin for subsequent in situ Cu(I)- or Pd(0)-mediated electrophilic substitution with retention of the double bond geometry. Notably, functionalization of the C(sp2)‒Ge bond was also achieved, enhancing germylenamides’ synthetic value. The radical germylzincation approach was further extended to other α-heteroatom-substituted alkynes, as well as more challenging conventional alkynes with excellent levels of stereocontrol. This work marked an important advance over prior art by offering modular access to elaborated di-, tri- and tetrasubstituted vinylgermanes that were not accessible by other methods thus far. From a wider perspective, the generality of the radical elementozincation approach was also preliminarily considered
Qi, Genggeng. "Unconventional radical miniemulsion polymerization." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26547.
Full textCommittee Chair: Jones, Christopher W.; Committee Chair: Schork, F. Joseph; Committee Member: Koros, William J.; Committee Member: Lyon, Andrew; Committee Member: Nenes, Athanasios. Part of the SMARTech Electronic Thesis and Dissertation Collection.