Dissertations / Theses on the topic 'Base radical'
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Chin, Melanie Soo, and m. chin@cqu edu au. "Towards a Reinterpretation of the Radical Theory of Associative Rings Using Base Radical and Base Semisimple Class Constructions." Central Queensland University. Computer Science, 2004. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20050411.102928.
Full textRahim, Medhat H., Radcliffe Siddo, and Moushira Issa. "Tangram-base Problem Solving in Radical Constructivist Paradigm: High School Student-Teachers Conjectures." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-83015.
Full textSanii, Laurie Shireen. "The effect of terminal base identity on radical cation injection into the DNA duplex." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/29377.
Full textPolenz, Ingmar, Andreas Laue, Tamas Uhrin, Tobias Rueffer, Heinrich Lang, Friedrich Schmidt, and Stefan Spange. "Thermally cleavable Imine Base / Isocyanate Adducts and Oligomers suitable as Initiators for Radical Homo- and Copolymerization." Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-152196.
Full textDieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
Cassas, Fernando Albregard. "O acompanhamento terapêutico como prática do analista do comportamento: uma caracterização histórica com base no behaviorismo radical." Pontifícia Universidade Católica de São Paulo, 2013. https://tede2.pucsp.br/handle/handle/16716.
Full textThe work presented here is motivated by a clinical intervention that began to be practiced by behavior analysts in Brazil in the early 1990s. This form prioritizes the work in the natural environment and, therefore, more likely to act directly on controlling contingencies of client behavior. This type of control seems to have established in the literature, a polarization between Therapeutic Accompaniment (TA) and the clinical based on the greater or lesser ability to control to be undertaken on the client behavior. The research presented here aims to resume and analyze the therapeutic practices of radical behaviorist base in order to establish a comparison between them and the TA, thus define whether it is possible to assert the existence of this polarization. Four sets of papers were analyzed: bases of behavior therapy: publications Skinner and Ferster about therapy, the Behavior Modification; literature on the following therapeutic approaches: Functional Analytic Therapy, Acceptance and Commitment Therapy, Behavioral Activation, the literature on the brasilian therapeutic proposals: Analytical Behavioral Therapy, Therapy of Contingencies of Reinforcement, Pragmatic Behavioral Psychotherapy and Molar and Self Therapy, beyond literature about the TA. To compose this analysis, four analytical categories were developed: core concepts for the diagnosis, intervention strategies, effectiveness and generality. The analysis of the studies cited showed that the polarization in the terms formulated above, is not true because all proposed schedule forms to ensure the generalizability of the results. Could be defined, however, the existence of a "minimum repertoire client". This concerns the modeling repertoire of verbal behavior that will allow the client to modify alone, the environment itself. And that is the reason for this study in a natural environment where the client does not have the repertoire to modify their own environment independently, the therapist operates the changing client environment in order to build a better learning condition for that client. From this, suggestions for future research are made at the end of the work
A tese aqui apresentada é motivada por um trabalho de intervenção clínica que começou a ser praticado por analistas do comportamento brasileiros no início da década de 1990. Essa forma prioriza o trabalho em ambiente natural e, com isso, maior chance de atuar diretamente nas contingências controladoras do comportamento do cliente. Esse tipo de controle parece ter estabelecido, na literatura da área, uma polarização entre o Acompanhamento Terapêutico (AT) e o consultório com base na maior ou menor possibilidade de controle a ser assumido sobre o comportamento do cliente. A pesquisa aqui apresentada se propõe a resgatar e analisar as práticas terapêuticas de base behaviorista radical com vistas a estabelecer uma comparação entre elas e o AT para, assim, definir se é possível afirmar a existência dessa polarização. Para isso, quatro conjuntos de trabalhos foram analisados: bases da terapia comportamental: publicações de Skinner e de Ferster respeito da terapia, e sobre a Modificação de Comportamento; a literatura sobre as seguintes propostas terapêuticas: Functional Analytic Therapy, Acceptance and Commitment Therapy, Behavioral Activation; a literatura sobre as propostas terapêuticas nacionais: Terapia Analítico‐ comportamental, Terapia por Contingências de Reforçamento, Psicoterapia Comportamental Pragmática e Terapia Molar e de Autoconhecimento, além da literatura acerca do Acompanhamento Terapêutico. Para compor essa análise, foram desenvolvidas quatro categorias analíticas: conceitos centrais para o diagnóstico, estratégias de intervenção, efetividade e generalidade. A análise dos trabalhos citados apontou que a polarização, nos termos formulados acima, não acontece, pois todas as propostas programam formas garantir a generalização dos resultados. Foi possível definir, no entanto, a existência de um repertório mínimo de cliente . Esse repertório diz respeito a modelagem de comportamento verbal que permitirá ao cliente modificar, sozinho, o próprio ambiente. E essa é a justificativa do trabalho em ambiente natural, quando o cliente não tem repertório para modificar o seu próprio ambiente de forma independente, o terapeuta opera mudando o ambiente do cliente de maneira a construir uma condição de aprendizagem melhor para esse cliente. A partir disso, sugestões para pesquisas futuras são feitas ao final do trabalho
Baguenard, Céline. "Synthèse et caractérisation d’architectures macromoléculaires complexes à base d’un bloc « stimuli-responsive »." Thesis, Lyon, INSA, 2012. http://www.theses.fr/2012ISAL0009.
Full textPH- or temperature-responsive polymers become hydrophobic from a critical pH or temperature. When they are associated to a hydrophilic block, they may respond to a stimulus by forming reversible micelles in aqueous solution. This thesis mainly deals with the synthesis by controlled radical polymerization of ABC- or ACB-type triple hydrophilic block copolymers, based on a highly hydrophilic block (PEO, A-block), a pH- and temperature-responsive moiety (PDMAEMA, B-block) and a cationic sequence (PDMAEMAquat, C-block). As their characterization by SEC in aqueous phase was not conclusive, they were therefore analyzed by diffusional NMR. In addition, their self-assembly in aqueous solution depending on pH or temperature was studied by 1H NMR and DLS. Furthermore, the cationic C-block form a so-called polyelectrolyte complex with a negatively charged polymer (PSS). Objects resulting from the complexation between the last block of ABC-triblock and PSS were characterized by 1H NMR, DLS, diffusional NMR and TEM. Their behavior in aqueous solution was also investigated depending on pH and temperature
Michel, Eléonore. "Recouvrements à base de dextrane pour applications médicales." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCD086/document.
Full textThe last decades have witnessed the remarkable growth of biomaterial science and engineering field, especiallyfor cardiovascular applications, for which devices have evolved from simple material to complex structures.This development has stemmed from the necessity for biomaterials to exhibit different properties, related totheir function, which are not always inherently compatible. Historically, the first materials selected for medicaldevices conception were the ones exhibiting the best compromise between all the physicochemical, mechanicaland biological requirements. Nevertheless, while physicochemical and mechanical properties are often handilycombined, the development of materials which also possess suitable biological properties have proved to bemuch more challenging, leading to clinical complications.Surface modification represents a valid solution to improve the biological performances of medical deviceswhile maintaining the bulk properties of the material. Biomaterial coatings may modulate the biologicalresponse at the biomaterial-host interface and decreases the undesirable effects. Coatings have been optimizedin regards to two main aspects: the biological response and the mechanical response. For the biologicalresponse, the two main approaches consist in 1) inducing cell adhesion, proliferation or migration with proactivecoatings and 2) using inert material, mostly, and avoiding the adhesion of any biological componentswith passive coatings.More complex coatings include the two approaches, allowing the adhesion of a specific type of cell whilerepelling other biological components adhesion. This method has been very useful against the restenosisphenomenon which obstructs blood vessels. A common practice is vessel stenting, a procedure that enables thereopening of the vessel and the restoration of the blood flow. Restenosis causes the new narrowing of the vessel,mostly due to uncontrolled smooth muscle cell proliferation. Researchers looked for coatings capable oflimiting the restenosis occurrence by inhibiting this cell proliferation along with facilitating the reendothelialization.Thus, the coatings would be able to improve endothelial cells adhesion and proliferation andto inhibit smooth muscle cells ones as well as avoiding non-specific adhesion.Previous studies showed that a copolymer made of dextran and poly(butyl methacrylate) (PBMA) demonstratedsuch biological properties and a good resistance to deformation, which is an important parameter related to thedeformation implied in a stent implantation. In this work, the approach was to use this copolymer as a stentcoating and to increase its long-term stability by providing covalent bonds with the substrate. To do so, thedextran part of the copolymer firstly needed to be activated in order to be grafted to the surface. Thus, it wasimportant to ascertain the influence of the multiple modifications on the biological and mechanical propertiesof the resulting materials at each step, but also towards a chemical point of view, the influence that thesemodifications may have on the subsequent copolymerization
Chalasani, Sri Lakshmi. "RESOLUTION OF PROXIMAL OXIDATIVE BASE DAMAGE AND 3′-PHOSPHATE TERMINI FOR NONHOMOLOGOUS END JOINING OF FREE RADICAL-MEDIATED DNA DOUBLE-STRAND BREAKS." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5237.
Full textÁlvares, Antonio Carlos Teixeira. "Inovação horizontal: um modelo ambidestro de gestão da inovação com base em um caso brasileiro." reponame:Repositório Institucional do FGV, 2018. http://hdl.handle.net/10438/25712.
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Esta pesquisa trata da questão dos efeitos provocados pela busca da inovação a partir de todas as pessoas da organização, particularmente da possibilidade da organização se tornar inovadora, assim entendido como capaz de produzir sistematicamente inovações de qualquer natureza e magnitude. Tal questão é relevante pois a inovação a partir de todas as pessoas de uma organização, praticamente não tem sido estudada pelos especialistas em inovação. Apesar de muito abordada pelo movimento de qualidade no tema de melhoria continua via sistemas de sugestões do tipo kaizen. A denominação Inovação Horizontal foi criada pelo autor para designar as inovações que se originam a partir de todos os funcionários da organização, usualmente a partir de programas internos de sugestões. Os sistemas internos de sugestões produzem basicamente inovações incrementais, denominadas pelos especialistas em qualidade como melhorias contínuas. Alguns autores apresentaram no passado a teoria de que novações incrementais competem com as inovações radicais. Em contraposição foi criado o conceito de ambidestria segundo o qual as organizações inovadoras produzem tanto inovações radicais quanto incrementais. A presente pesquisa a foi baseada em estudo de caso único de uma empresa de um setor maduro (metalurgia) que pratica Inovação Horizontal (a partir de todas as pessoas). Foram entrevistados dezoito gestores, todos os quatro diretores executivos, dez gerentes, dois coordenadores gerais e dois pesquisadores aposentados. O resultado indicou que a organização é inovadora sistemática, tendo criado um modelo de gestão da inovação ambidestro que produz sistematicamente inovações incrementais e radicais, tanto de produtos como de processo e gestão.
This research deals with the effects caused by the search for innovation from all the people of the organization, particularly the possibility of the organization becoming innovative, understood as capable of systematically producing innovations of any nature and magnitude. This issue is relevant because innovation from all the people of an organization, practically has not been studied by the experts in innovation. Although much approached by the movement of quality in the theme of continuous improvement via kaizen type suggestion systems. The denomination Horizontal Innovation was created by the author to designate the innovations that originate from all the employees of the organization, usually from internal programs of suggestions. Internal feedback systems basically produce incremental innovations, called by quality experts as continuous improvements. Some authors have in the past presented the theory that incremental innovations compete with radical innovations. In contrast, the concept of ambidexterity was created whereby innovative organizations produce both radical and incremental innovations. The present research was based on a single case study of a company from a mature sector (metallurgy) that practices Horizontal Innovation (from all people). Eighteen managers, all four executive directors, ten managers, two general coordinators and two retired researchers were interviewed. The result indicated that the organization is a systematic innovation, having created an ambidextrous innovation management model that systematically produces incremental and radicals innovations, of product, process and management.
Ferreira, Adriana de Souza Sergio. "Implante permanente de sementes de iodo e prostectomia radical em portadores de câncer de próstata: análise comparativa de uma coorte de base hospitalar." Universidade Federal de Juiz de Fora (UFJF), 2010. https://repositorio.ufjf.br/jspui/handle/ufjf/2610.
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Este estudo teve como objetivo analisar e comparar a sobrevida livre de recidiva bioquímica em cinco anos e fatores prognósticos em pacientes portadores de câncer de próstata submetidos à braquiterapia ou cirurgia radical. Foram analisados 129 pacientes com câncer de próstata, destes 64 foram submetidos à braquiterapia permanente com sementes de Iodo 125 e 75 pacientes foram tratados com prostatovesiculectomia radical, no período de janeiro de 2002 a dezembro de 2005, em um hospital da rede privada da cidade de Juiz de Fora-MG. As principais variáveis analisadas, coletadas dos prontuários dos pacientes, foram: idade, data de nascimento, PSA inicial, escore de Gleason à biópsia prostática e na peça cirúrgica para os pacientes operados, estadiamento clínico e patológico para os casos cirurgicos, volume da próstata ao pré-planejamento e no momento da braquiterapia, atividade das sementes de Iodo 125 e dosagens seriadas de PSA após o tratamento. Os pacientes foram classificados, segundo D’Amico, em grupos de risco: baixo, intermediário e alto. A recidiva bioquímica foi definida como níveis de PSA> 0,4ng/ml para os casos de prostatectomia radical e três elevações consecutivas de PSA para os pacientes implantados (ASTRO). Para estudo do efeito do tratamento na sobrevida livre de recidiva bioquímica foram geradas curvas de Kaplan-Meier, e teste de log-rank foi usado para determinar diferenças entre as curvas. A influência de múltiplas variáveis na sobrevida livre de recidiva bioquímica, como Gleason, estadiamento, iPSA, categoria de risco e idade foram estimados por regressão de Cox. No primeiro artigo, foi observada taxa de sobrevida livre de recidiva bioquímica superior (p=0,0056) para os pacientes submetidos à braquiterapia 79,70% (IC95%:66,87-87,99) quando comparado aos pacientes submetidos à cirurgia 44,30% (IC95%:23,28-63,47) sendo identificados como fatores prognósticos associados de forma independente à sobrevida livre de recidiva bioquímica a modalidade terapêutica (HR= 3,33 ;IC95% :1,41-7,88), os níveis séricos de iPSA (HR=2,54;IC95%:1,11-5,78) e a categoria de risco (HR=4,18 ;IC95%:1,89-9,23). No segundo artigo, que avaliou somente os pacientes submetidos à braquiterapia, foi verificada uma taxa de sobrevida livre de recidiva bioquimica em cinco anos, significativamente superior (p=0,0012) para os pacientes do grupo de baixo risco 91,6% (IC 95%:75,92-97,24), quando comparada com àquela dos pacientes do grupo de risco intermediário/alto 59,19% (IC 95%:36,00-76,40). A sobrevida livre de recidiva bioquimica também foi significativamente superior nos pacientes com iPSA ≤ 10ng/ml (p=0,0084) e com escore de Gleason ≤ 6 à biópsia prostática (p=0,0057). Na análise multivariada, o risco de falha bioquímica também se manteve maior nos pacientes que pertenciam ao grupo de risco moderado/alto e para pacientes com iPSA superior a 10ng/ml. Os dados de sobrevida livre de recidiva bioquimica em cinco anos, para os pacientes desta análise, tratados com braquiterapia, foram comparáveis aos da literatura.
This study aimed to analyze and compare the biochemical relapse-free survival at five years and prognostic factors in patients with prostate cancer undergoing radical surgery or brachytherapy. We analyzed 129 patients with prostate cancer, these 64 underwent brachtherapy with permanent seeds implantation and 75 patients were treated with radical prostatectomy, from January 2002 to December 2005 in a private hospital network in the city of Juiz de Fora-MG. The main variables analyzed were collected from medical records and were: age, date of birth, initial PSA, Gleason score of prostate biopsy and of surgical specimens, clinical and pathologic staging on surgical cases, the prostate volume pre-planning and at the time of brachytherapy, seed activity of lodine 125 and serial measurements of PSA after treatment. Patients were classified according to D’Amico, at risk groups; low, intermediate and high. The biochemical recurrence was defined as PSA levels>0.4 ng/ml for cases of radical prostatectomy and three consecutive elevations of PSA for patients implanted (ASTRO). For the study of the effect of the treatment on biochemical relapse-free survival Kaplan-Meier curves were generated, and log rank test was used to determine the differences among the curves. The influence of multiple variables in the biochemical relapse-free survival as age, initial PSA, Gleason score, staging and risk category was estimated by Cox regression. In the first article, was observed rate of biochemical relapse-free survival superior (p = 0.0056) for patients undergoing brachytherapy 79.70% (CI95% :66,87-87, 99) when compared with patients undergoing surgery 44.30% (CI95% :23,28-63, 47) and were identified as prognostic factors independently associated with survival free of biochemical recurrence modality therapy (HR = 3.33, CI95% :1,41-7 88), serum levels of IPSA (HR = 2.54, CI95% :1,11-5, 78) and risk category (HR = 4.18, CI95% :1,89-9, 23). In the second article, which evaluated only the patients who underwent brachytherapy, there was a rate of biochemical relapse-free survival at five years, significantly higher (p = 0.0012) for patients with low-risk group 91.6% (CI 95% :75,92-97, 24), when compared with that of patients in the intermediate/high risk group 59.19% (CI95% :36,00-76, 40).The biochemical relapse-free survival was also significantly higher in patients with IPSA ≤ 10ng/ml (p = 0.0084) and Gleason score ≤ 6 on prostate biopsy (p = 0.0057). In multivariate analysis, the risk of biochemical failure also remained higher in patients who belonged to the group of moderate / high risk and patients with IPSA more than 10ng/ml. Data from biochemical relapse-free survival at five years for the patients of this analysis were comparable to literature.
Ghadban, Ali. "Synthèse et caractérisation de glycopolymères à base d'oligoalginates en milieu aqueux." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00923140.
Full textBoursier, Thomas. "Synthèse et caractérisation de copolymères à base d’acide méthacrylique et de nouveaux macromonomères hydrophiles : rôle de leur solvatation sur la fluidité et la viscosité des compositions cimentaires." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10006.
Full textThe objective of this PhD work is the evaluation of the role of the solvation of PCP (grafted copolymer used in concrete as additive) on the concrete fluidity and viscosity. Grafted copolymers with different side-chains were synthesized. The solvation state of the PCP was estimated by mean of the χ Flory-Huggins parameter. The latter was calculated from the 2nd virial coefficient A2, itself determined by light scattering measurements. χ -parameter values of 0,37 ; 0,43 ; 0,47 and 0,48 are obtained for PCP respectively possessing ethylene glycol (EG), 2-methyloxazoline, N-vinylpyrrolidone and N-acryloylmorpholine-based side-chains. The surface coverage of the PCPs and their layer thickness can be calculated with Flatt’s formula. The introduction of the PCPs at different contents (therefore different surface coverage ratio) to calcite suspensions showed that at same surface coverage ratio, all PCPs induce the same fluidity, although the adsorbed PCP layer thickness differed up to 50% in the certain cases. The surface coverage played also a keyrole in the suspensions viscosity. The transposition of these results to a mortar seemed however risky since PCPs might lead to hydration delays depending on the chemical nature of the side-chains
Dumas, Ludovic. "Post-modification par irradiation γ de polymères à base de fluorure de vinylidène : Applications aux membranes séparatrices de supercapacité." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00801543.
Full textNzulu, Frida. "Développement de procédés de polymérisation catalysés par des complexes d'or." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066445.
Full textThe aim of this PhD work was to develop highly effective polymerization processes using gold complexes and the synthesis of original polymers. On the first research topic we have developed the first polymerization process through a gold carbenoic intermediate, leading to an original polymer composed by a phenyl vinylcyclopropyl monomer unit. This methodology was utilized to the polymerization of a variety of propargylic esters. Special attention has been paid to increase the solubility and the polymerization degree of the polymers. Post-functionnalization by hydrolysing the ester group leads to a new polyketone architecture. Preliminary electric studies showed that this conjugated polycyclopropane acts as a semi-conductor. The aim of the second research topic was to control efficiently the formation of block copolymers by combining living cationic and photo-induced radical polymerizations catalyzed in a one-pot procedure. A dinuclear gold(I) complex based photocatalyst [Au2(μ-dppm)2]Cl2 catalyzed efficiently polymerization of acrylates in solution and in laminate through an atom transfer radical polymerization process controlled by light exposure (visible or UV-A light). Finally, preliminary results showed it is possible to combine cationic reversible addition-fragmentation chain transfer polymerization catalyzed by a Lewis acid with radical reversible addition-fragmentation chain transfer polymerization without photoredox catalyst or radical initiator but only with an external stimuli, the light
Zarrouki, Arthur. "Synthèse de polymères à base d'éthylène pour additiver les carburants." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1039.
Full textThe additivation of diesel fuels allows operating engines at low temperatures without filter blocking and thus fulfilling legal requirements. Ethylene based copolymers such as ethylene-vinyl acetate copolymers, made by free radical polymerization at high pressure (above 2000 bars) and high temperature (above 200 °C) are frequently used as middle distillate cold flow improvers (MDFI). A new free radical copolymerization process of ethylene and vinyl acetate in organic solvent media has been developed. This process gives access to polymers close to commercial MDFI additives under tremendous less drastic conditions (under 250 bars of ethylene and 70 °C). Thanks to this process, a wide diversity (variation of the nature of the polar unit, of polymer architecture…) of ethylene based polymers was obtained. Moreover, EVA model copolymers have been synthesized by metathesis. Thanks to these numerous and diverse ethylene based polymers combined with thermal analysis and X-ray scattering studies a better understanding of the operating mode of these additives in a diesel fuel has been achieved. The structural characteristics of the polymers enabling their effectiveness as diesel fuel cold flow improvers have also been established
Loste, Julien. "Elaboration de matériaux composites transparents à base de nanoparticules hybrides cœur@écorce." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3054/document.
Full textThe incorporation of inorganic particles into a polymer matrix confers new properties to the material or enhances significantly existing properties. However, the perceived visual appearance, such as loss of transparency, might be modified by the scattering of light by the particles. This light scattering is mainly due to the particle –or aggregates of particles- dimensions and the refractive index difference between matrix and fillers. In order to address both issues, the objective of the present work was to control simultaneously the dispersion state of the inorganic nanoparticles into the polymeric matrix and the refractive index of the nanoparticles to match the one of the matrix. To achieve this new composite, we designed hybrid core@shell nanoparticles with an inorganic core that brings new properties and a polymer shell of controlled thickness, obtained by surface-initiated nitroxide mediated controlled radical polymerization. The polymer shell limits the aggregation of the particles and enables us to tune the average refractive index of the hybrid core@shell particle. By controlling the thickness and the chemical nature of the polymeric shell, we targeted to match the refractive index of the hybrid core@shell particle to the one of the polymeric matrix. The nanoparticles were further dispersed into a poly(methyl methacrylate) matrix. Optical properties of composites were characterized by spectrogoniophotometry which gave us informations about the intensity and the angular distribution of the transmitted light by the nanocomposites. The transparency of the nanocomposites was strongly enhanced for core@shell particles fulfilling the refractive index matching conditions
Borisova, Olga. "Synthèse et contrôle de l'auto-assemblage de nouveaux copolymères à gradient à base de styrène et d'acide acrylique." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3018/document.
Full textThe main goal of our work was the synthesis and the study of solution properties of novel amphiphilic di- and triblock-gradient copolymers based on styrene and acrylic acid which are capable of reversible association in aqueous solution. We studied the kinetics and the mechanism of nitroxide-mediated radical polymerization (NMP) in order to determine the quantitative characteristics of the reversible termination reaction in this process. Then NMP was employed to the synthesis of two different block-gradient copolymer architectures: di- and triblock-gradient copolymers. The self-assembly of the block-gradient copolymers in water was studied by DLS, SANS and TEM. The reversible changes of aggregation numbers in cycles of pH were observed. We also investigated the effect of pH and ionic strength on rheological properties of triblock-gradient copolymer solution. Then, we synthesized polymer brushes on the gold-coated surface and studied their pH- and electro-responsive properties in aqueous media
Önal, Emel. "Molecular magnetic materials based on porphyrin macrocyles." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10103/document.
Full textThe preparation of Molecule-Based Magnets is based on the assembling carriers of magnetic moment. These may be the metal ions only with diamagnetic linkers or the metal ions connected through open-shell organic molecule. The building of novel Molecule-Based Magnets architectures following the metal-radical approach relies on the design of innovative open-shell organic molecular blocks. In this regard, we focus our strategy on the synthesis of porphyrins incorporating free radicals. Indeed, porphyrins compounds are π-conjugated systems which should favor spin delocalization and the transmission of the magnetic interactions on the overall macrocycle and further over the all architecture. Due to their excellent stability in a wide variety of chemical environments, and their abilities to coordinate with transition metal we focus our attention on nitroxide radicals. In this dissertation a series of porpyrin macrocycles were synthesized, bearing tBuNO, nitronyl and imino nitroxide covalently linked to the skeleton. Characterization was done by UV-Vis, Mass and EPR spectroscopy. Moreover during this work some interesting synthetic intermediates were obtained with good yield and characterize for the first time. This was the case for meso-tetrakis(4-formylphenyl)porphyrin and its corresponding metallated derivatives by Cu(II) and Mn(II). Some novel promising tetrapyrrolic macrocycle precursors bearing nitronyl and imino nitroxides free radicals as 2-(3,4- dicyanophenyl)-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl, 2-(3,4- dicyanophenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl and 2-(4-benzaldehyde)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl. To the best of our knowledge, these compounds represent the first example of nitronyl and imino nitroxide substituted porphyrin derivatives that have been unambiguously characterized by spectroscopic techniques
Akin, Myles. "Site specific thermodynamic study of OH radical addition to DNA bases." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33919.
Full textFabrello, Chantal. "Etude et realisation d'une preforme de fibre optique en polymere a base de methacrylate de methyle." Toulouse 3, 1986. http://www.theses.fr/1986TOU30127.
Full textKhchoum, Salem. "Les affixes/créments dans le lexique de l'arabe : exploration du niveau submorphémique de l'arabe." Thesis, Lyon, École normale supérieure, 2014. http://www.theses.fr/2014ENSL0963.
Full textThis thesis is part of the revisionist work on the structure of the Semitic root in general, and the Arabic root in particular. In the introduction, we present a critical review of the efforts of Arab grammarians in their quest of a minimum linguistic threshold associated with meaning, a quest that resulted in establishing the triliteral root as the ultimate unanalysable unit. This choice was made despite the many obvious shortcomings of this theoretical framework, such as its inability to explain the reversal of the order of consonants, or their phonetic variation (regardless of its meaning). It is an anhistorical, synchronic choice that excludes the notion of time, and finds its roots in a revelationnist (tawqîf) linguistic framework. In the end of the nineteenth century, the extended Darwinist theory has undermined this static conception of the root. By integrating the notion of time, a number of Orientalists - followed by some Arab philologists of that period - showed, through a comparative methodology, that the triliteral root has evolved from a primitive monosyllabic (or biconsonantal) root. Since then, several explanations have been proposed for the formation of the triliteral root from a biliteral base (crossed bilateral roots, affixation of formative increments or determinatives).Some linguists, such as Hurwitz, tried to identify and to systematize by deduction the ternary elements and their semantic values. In this work, which is carried within the framework of the Matrix and Etymons Theory , we demonstrate through the synchronic analysis of nearly 1,000 trilateral items that the triliteral root is analyzable in terms of biliteral etymons and of separable increments or affixes added at the beginning (prefixation), the middle (infixation) or the end (suffixation) of bilateral bases.The characteristic elements that can be affixed or incremented on the base are phonetically similar (gutturals, sonorants, labial, and some dentals) and correlated often with the same grammatical (factitive, stative, reflexive or middle voice) or semantic (intensive) values. The third position of the root is the position favored in this process of affixation / incrementation. Thus, the triliteral root is not the minimal threshold of meaning, and can be broken down to a biconsonantal base, which became triliteral thanks to an incremental or affixal segment. These findings may affect our perception of the Arabic lexicon, which can now be rearranged around biliterals bases, either abstract ( i.e. phonetic features), or concrete (i.e. historical primitive etymons) that are in turn convertible into triliteral radicals through a preliminary list increments and affixes that specify the primary meaning conveyed by the bilateral base
Robbes, Anne-sophie. "Nanocomposites à base de particules magnétiques : synthèse et contribution de la dispersion des charges et de la conformation des chaines sur les propriétés de renforcement." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112201/document.
Full textThe mechanical properties of polymeric nanocomposite films can be considerably enhanced by the inclusion of inorganic nanoparticles due to two main effects: (i) the local structure of fillers dispersion and (ii) the potential modification of the chains conformation and dynamics in the vicinity of the filler/polymer interface. However, the precise mechanisms which permit to correlate these contributions at nanometric scale to the macroscopic mechanical properties of the materials are actually poorly described. In such a context, we have synthesized model nanocomposites based on magnetic nanoparticles of maghemite γ-Fe2O3 (naked or grafted with a polystyrene (PS) corona by radical controlled polymerization) dispersed in a PS matrix, that we have characterized by combining small angle scattering (X-Ray and neutron) and transmission electronic microscopy. By playing on different parameters such as the particle size, the concentration, or the size ratio between the grafted chains and the ones of the matrix in the case of the grafted fillers, we have obtained nanocomposite films a large panel of controlled and reproducible controlled filler structures, going from individual nanoparticles or fractal aggregates up to the formation of a connected network of fillers. By applying an external magnetic field during the film processing, we succeeded in aligning the different structures along the direction of the field and we obtained materials with remarkable anisotropic reinforcement properties. The conformation of the chains of the matrix, experimentally determined thanks to the specific properties of neutron contrast of the system, is not affected by the presence of the fillers, whatever their confinement, the dispersion the fillers or their chemical state surface. The alignment of the fillers along the magnetic field has allowed us to describe precisely the evolution of the reinforcement modulus of the materials with the structural reorganization of the fillers and the chains at the local scale under stretching, and thus to highlight the key role played by the fillers reorganization under stretching on the nanocomposite reinforcement mechanisms
Wickenden, Jason. "Development of heteroatom radical based synthetic strategies." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45730.
Full textBertho, Sylvain. "Fonctionnalisation d’énamides par voie radicalaire : Catalyse au fer ou application de la chimie des xanthates." Thesis, Orléans, 2018. http://www.theses.fr/2018ORLE2060.
Full textThe aim of the thesis is to study the addition of radical species on non-aromatic enamide scaffolds in order to access high molecular diversity of cyclic and acyclic nitrogen-containing compounds in a restricted number of steps via sustainable eco-friendly regio- and diastereoselective reactions.Firstly, non-aromatic enamides bearing different functional groups have been synthesized. Then a regio- and diastereoselective iron-catalyzed oxyazidation of enamides was developed in the presence of novel azidobenziodoxolones (ABX) derivatives under mild reaction conditions. In addition, the versatility of the trans α-azido β-esters piperidines was highlighted by the synthesis of various original nitrogen-containing polycycles.Subsequently, C3 alkylation of enamides with α-halogenocarbonyles. was carried out through an iron (II)-catalysis or a metallic iron-mediated process.Finally, radical xanthate chemistry was applied to achieve the metal-free alkylation of the C3 position of enamides or the difunctionalization of enamides in the presence of a nucleophile
Weaving, R. "Studies on iron based oxidation." Thesis, University of Sussex, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299031.
Full textAjavakom, Anawat. "Novel radical based routes to pyrrolidine trans lactams." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288468.
Full textAlves, Lemes Maykon. "Magnetic Exchange Coupling in 3d and 4f Complexes Using Radical Tetrazine-based Frameworks." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39598.
Full textBrazi, Eric. "Activation de la liaison C-H : hydroxylation catalytique des hydrocarbures par de nouveaux complexes alkylperoxydiques de cobalt (iii), déshydrogénation sélective et catalytique de cycloalcanes en présence d'éponges à hydrogènes à base d'uranium métal." Paris 6, 1987. http://www.theses.fr/1987PA066680.
Full textSmith, Gregory Brian. "Investigations into the effects of chain-length-dependent termination and propagation on the kinetics of radical polymerisation." Thesis, University of Canterbury. Chemistry, 2008. http://hdl.handle.net/10092/1455.
Full textMalet, Federic Louis Gino. "Aqueous ATRP of amine-based methacrylates." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367786.
Full textSadofiev, Sergey. "Radical-source molecular beam epitaxy of ZnO-based heterostructures." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2009. http://dx.doi.org/10.18452/16054.
Full textThis work focuses on the development of the novel growth approaches for the fabrication of Group II-oxide materials in the form of epitaxial films and heterostructures. It is shown that molecular-beam epitaxial growth far from thermal equilibrium allows one to overcome the standard solubility limit and to alloy ZnO with MgO or CdO in strict wurtzite phase up to mole fractions of several 10 %. In this way, a band-gap range from 2.2 to 4.4 eV can be covered. A clear layerby- layer growth mode controlled by oscillations in reflection high-energy electron diffraction makes it possible to fabricate atomically smooth heterointerfaces and well-defined quantum well structures exhibiting prominent band-gap related light emission in the whole composition range. On appropriately designed structures, laser action from the ultraviolet down to green wavelengths and up to room temperature is achieved. The properties and potential of the "state-of-the-art" materials are discussed in relation to the advantages for their applications in various optoelectronic devices.
Cheng, Qigan. "Co(II)-Based Metalloradical Catalysis for Asymmetric Radical Cyclopropanation." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6206.
Full textBaltazar, Junior Rene Carlos Cardoso. "Lema de Seidenberg para computar geradores de um radical." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/29248.
Full textThe goal of this work is to compute in some speci c cases the generators of the radical ideal in a polynomial ring K[x1, ..., xn]. For this, we use the theory of Groebner bases. First, we use Lemma Seidenberg to compute the generators of the radical of an zero-dimensional ideal, where K is a perfect eld and then we used the results of R. Matsumoto for a eld K of positive characteristic and perfect.
Fu, Rong. "Biochemical and Spectroscopic Characterization of Tryptophan Oxygenation: Tryptophan 2, 3-Dioxygenase and Maug." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/chemistry_diss/44.
Full textSoligon, Olivier. "Modélisation et animation du buste humain pour la compression de séquences d'images visiophoniques." Rennes 1, 1998. http://www.theses.fr/1998REN10043.
Full textDanialdoss, S. "Radical cyclisation based approaches to 9-pupukeanone and lignan precursors." Thesis, Indian Institute of Science, 1996. http://hdl.handle.net/2005/121.
Full textRatera, Bastardas Imma. "Ferrocene-Based Polychlorotriphenylmethyl radical: A new approach towards multiproperty materials." Doctoral thesis, Universitat Autònoma de Barcelona, 2002. http://hdl.handle.net/10803/3149.
Full textS'han estudiat les propietats magnètiques dels diferents mono- bi- i tri- radicals mitjançant les tècniques d'EPR i SQUID. A partir de les dades obtingudes pels biradicals estudiats, es pot concloure que el pont 1,1'-ferrocenilè actua com a acoblador ferromagnètic entre les dues unitats radicalàries connectades a ell. Quan el ferrocè és substituït amb grups metílics o bé és substituït per un rutenocè, l'acoblament magnètic entre les dues unitats radicalàries desapareix mostrant-se un comportament paramagnètic al llarg de tot el rang de temperatures mesurat. A partir de les dades de susceptibilitat magnètica dels monoradicals s'obtenen valors de magnetització molt alts a temperatura ambient els quals són un indici de la significant contribució orbitàlica de la fracció de Fe (III) per sobre del valor del spin orgànic sol. Aquest resultat suggereix un fenomen de transferència electrònica intramolecular entre el ferrocè i la unitat radicalària. A més a més, per un dels monoradicals sintetitzats, també se n'ha estudiat la isomerització trans - cis tant tèrmica com fotoinduïda mitjançant la tècnica de UV/Vis, ESR spectrosocopy així com també de cromatografia d'HPLC. Aquesta isomerització genera un procés d'autoassemblatge induït tan tèrmica- com fotoquímicament d'un sol sentit i representa un exemple molt interessant d'un sistema fotomagnètic basat en un fenomen supramolecular en el qual una espècie doblet es convertida a una espècie singlet.
Aquesta família de radicals policlorotrifenilmetílics units a un ferrocè també presenten un fenomen de transferència electrònica intramolecular del qual se'n pot modular la seva energia fàcilment mitjançant el canvi de substituents de la unitat donadora, acceptora o fins i tot canviant la naturalesa del dissolvent. Mesures d'absorció espectroscòpiques de temps de resolució de pico-segons ens han permès observar i monitoritzar per primera vegada l'espècie de càrregues separades la qual ens confirma per primera vegada el fenomen de transferència electrònica intramolecular fotoinduït. També ha estat descrit per primera vegada un nou exemple de tautomerisme de valència que combina un radical orgànic com a grup acceptor i un ferrocè com a grup donador.
Finalment, també s'ha comprovat que els radicals policlorotrifenilmetílics constitueixen un sèrie de compostos de capa electrònica oberta molt atractiva que combina elevades respostes d'ONL amb bones estabilitats químiques, tèrmiques i foto-òptiques, gràcies al seu caràcter octupolar. Els sistemes de ferrocens connectats a unitats radicalàries policlorotrifenilmetíliques també exhibeixen intenses respostes d'ONL les quals poden ser modulades mitjançant el canvi de capacitat donadora del metal.locè o accpetora del radical.
This thesis as part of a general effort aimed at extending the range of molecular materials combining two properties in the same molecule, has developed the synthesis and characterization of new series of metallocene (ferrocene and ruthenocene) based polychlorotriphenylmethyl mono, bi- and tri- radicals proving that it is possible their tuning by changing the donor ability of the metallocene unit, the acceptor ability of the radical unit and the nature of the bridge. The magnetic properties of different mono, bi and tri radicals have been studied by EPR and SQUID. From the magnetic data of the biradicals studied, it is conclude that the 1,1'-ferrocenylene bridge acts as a ferromagnetic coupler between the two radical units connected to it. When the ferrocene unit is substitute with methyl groups or it is changed for a ruthenocene unit, the magnetic exchange vanishes showing a paramagnetic behaviour in all the temperature range. From the magnetic susceptibility data for the monoradicals an outsized values of magnetization at room temperature is observed, which it is an indication of significant orbital contributions of the Fe(III) fraction over the spin value. This result suggests a temperature dependent intramolecular electron transfer phenomenon between the ferrocene and the radical unit. In addition, the thermal and photoinduced trans to cis isomerization of one of the monoradicals has been monitored by UV/Vis and ESR spectrosocopy and also followed by HPLC chromatography. This one-way thermal and photoinduced self-assembly process represents an interesting example of a photomagnetic system based on a supramolecular phenomenon in which a doublet species is converted into a singlet one.
Such ferrocene-polychlorotriphenylmethyl radicals present intramolecular electron transfer phenomenon which energy can be easily tuned by changing the substitutents of the donor or acceptor units or even the nature of the solvent. Picosecond time resolved absorption spectroscopy measurements allow us observing and monitoring for the first time the charge separation state that confirms the photoinduced electron transfer phenomena. It has also been described for the first time a novel valence tautomeric example combining an organic radical as acceptor unit and a ferrocene unit as the donor group.
Finally, it has been proved that polychlorotriphenylmethyl radicals constitute a very attractive open-shell series that combines both a high NLO response and good chemical, thermal, and photo-optical stabilities, thanks to their octupolar character. Ferrocene based polychlorotriphenylmethyl radicals systems also exhibits intense NLO responses that can be modulated at will simply tuning the donor and acceptor capabilities of the ferrocene and radical units.
Mateo-Alonso, Aurelio. "Radical-anions of macrocyclic 1,6 dialkoxyphenazines as chiral electrogenerated bases." Thesis, Queen Mary, University of London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407425.
Full textBasak, A. "Synthetic and biosynthetic studies based on radical and related processes." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370310.
Full textHo, Win Fung. "EPR spin-trapping studies of radical reactions with DNA bases." Thesis, University of York, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245967.
Full textSadeghipour, Mitra Jr. "Hydrocarbon Functionalization via a New Free Radical-Based Condensation Reaction." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30627.
Full textPh. D.
Yutronkie, Nathan. "Designing Molecular Materials Through Thiazyl-Based Radicals." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41202.
Full textSilva, Robson Pinho da. "Comportamento redox e detecção voltamétrica de neurotransmissores, nitrito, derivados purínicos e nitrofural em sensores eletroquímicos à base de carbono." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-02052013-102258/.
Full textChemical systems, which are able to produce OH• and O2•- free radicals, responsible for damage in DNA, were studied at different carbon modified electrode surfaces. Guanine carbon paste modified electrode was used to promote the nitrofural (RNO2) monoelectronic reduction to its respective nitro anion radical, RNO2•-, which attacked guanine immobilized on the electrode surface. The interaction in situ promoted the formation of guanine cation radicals (G+•) between guanine (G), after a dimerization process, were detected in the positive potential range by Differential Pulse Voltammetry, DPV. The other studied systems refer to development of new carbon modified electrodes or utilization of carbon modified electrodes, previously described, for the detection of several important biological molecules. Ascorbic acid (AA), uric acid (UA), xanthine (XA) and hypoxanthine (HX) were simultaneously detected at pyrolytic graphite electrode, previously modified into dopamine solution (EGPD), using DPV. The oxidation peak potentials, were obtained by cyclic voltammetry at 51; 393; 0.765 and 1080 mV vs Ag/AgCl, KCl(sat) for AA, UA, XA and HX, respectively. The detection limit for XA in presence of 5.0 x10-5 mol L-1 HX was 2.3 x10-6 mol L-1 (with sensibility of 2.8 A mol-1 L cm-2), while the detection limit for HX in presence of 5.0 x10-5 mol L-1 XA was 5.6 x10-6 mol L-1 (with sensibility of 1.4 A mol-1 L cm-2). XA and HX were determined in urine samples and the values founded were 0.47 µM e 5.9 µM, respectively. Serotonin (5-HT) and dopamine (DA) were simultaneously detected at glassy carbon electrode, previously modified in serotonin solution (ECV - 5HT). Serotonin was detected at 379 mV vs Ag/AgCl, KCl (sat), 31 mV less positive potential than that observed at bare glassy carbon electrode (410 mV), while DA was detected at 200 mV. No interference was observed in presence of (AA), tyrosine (Tyr), epinephrine (EP) and noradrenaline (NE). Finally, in the last stage of this work, lignin, extracted from Kraft liqueur, was solubilized in acetonitrile/H2SO4 and used to disperse multi-wall carbon nanotubes, MWNTC. This suspension was used to modify the glassy carbon electrode surface and nitrite was detected, by DPV in the concentration range of 4,0 x 10-6≤ [NO2-] ≤ 8,0 x 10-5 mol L-1. The complex formed between neocuproina and Cu (I), a compound which can produce free radicals and thereby cause damage to DNA, was synthesized and characterized.
Wen, Xin. "The Utilization of Sulfonylhydrazones as New Radical Precursors for Asymmetric Radical C–H Alkylation via Co(II)-Based Metalloradical Catalysis." Thesis, Boston College, 2019. http://hdl.handle.net/2345/bc-ir:108292.
Full textAsymmetric C–H functionalization represents one of the central topics in modern organic chemistry, which allows for the direct installation of functional groups onto ubiquitous C–H bonds in organic molecules. Among numerous elegant strategies, transition metal-catalyzed C–H alkylation with diazo compounds represents one of the most powerful methods for C–C bond formation. Different from Fischer metallocarbene-based C–H insertion reactions, cobalt(II)-based metalloradical catalysis (MRC) is recently proven to be capable of activating acceptor/acceptor diazo compounds for radical C–H alkylation reactions via H-atom abstraction. In this dissertation, we have developed several systems by utilizing less-explored aryl and alkyl diazomethanes as new radical precursors for highly enantioselective radical C–H alkylation reactions, which permit the efficient synthesis of different optically active heterocyclic compounds. First, we have demonstrated the feasibility of using aryl aldehyde-derived sulfonylhydrazones as new radical precursors for enantioselective radical C–H alkylation to synthesis enantioenriched 2,3-dihydrobenzofuran derivatives. Notably, a general and mild way for in situ generation of diazo compounds have been identified by using 2,4,6-triisopropyl sulfonyl hydrazone as diazo precursor, which allow us to regulate the reaction temperature to achieve the high enantioselectivity for the desired radical reactions. Second, the utility of Co(II)-based MRC has been further highlighted by enantioselective indoline synthesis. Through the design and synthesis of new catalysts, the system is shown to have a broad spectrum of substrate scope, forming various 2-substituted indolines with up to 98% yield and 96% ee. A series of mechanistic studies further support the underlying stepwise radical alkylation pathway. Finally, we further expand the applicability of MRC to even more challenging diazo compounds, aliphatic diazomethanes. Starting from alkyl aldehyde-derived sulfonylhydrazones as diazo precursors, the Co(II)-based radical alkylation reactions allow for the enantioselective synthesis for common 2-substituted tetrahydrofuran structures with high yields and excellent enantioselectivities
Thesis (PhD) — Boston College, 2019
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
LACERDA, Estefane George Macedo de. "Model Selection of RBF Networks Via Genetic Algorithms." Universidade Federal de Pernambuco, 2003. https://repositorio.ufpe.br/handle/123456789/1845.
Full textUm dos principais obstáculos para o uso em larga escala das Redes Neurais é a dificuldade de definir valores para seus parâmetros ajustáveis. Este trabalho discute como as Redes Neurais de Funções Base Radial (ou simplesmente Redes RBF) podem ter seus parâmetros ajustáveis definidos por algoritmos genéticos (AGs). Para atingir este objetivo, primeiramente é apresentado uma visão abrangente dos problemas envolvidos e as diferentes abordagens utilizadas para otimizar geneticamente as Redes RBF. É também proposto um algoritmo genético para Redes RBF com codificação genética não redundante baseada em métodos de clusterização. Em seguida, este trabalho aborda o problema de encontrar os parâmetros ajustáveis de um algoritmo de aprendizagem via AGs. Este problema é também conhecido como o problema de seleção de modelos. Algumas técnicas de seleção de modelos (e.g., validação cruzada e bootstrap) são usadas como funções objetivo do AG. O AG é modificado para adaptar-se a este problema por meio de heurísticas tais como narvalha de Occam e growing entre outras. Algumas modificações exploram características do AG, como por exemplo, a abilidade para resolver problemas de otimização multiobjetiva e manipular funções objetivo com ruído. Experimentos usando um problema benchmark são realizados e os resultados alcançados, usando o AG proposto, são comparados com aqueles alcançados por outras abordagens. As técnicas propostas são genéricas e podem também ser aplicadas a um largo conjunto de algoritmos de aprendizagem
Wirth, Manfred P., and Oliver W. Hakenberg. "Curative Treatment of Prostate Cancer." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-133890.
Full textDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
Simões, Alexandre da Silva. "Aprendizado não-supervisionado em redes neurais pulsadas de base radial." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-15092006-153353/.
Full textPulsed neural networks - networks that encode information in the timing of spikes - have been studied as a new and promising approach in the artificial neural networks paradigm, emergent from cognitive science. One of these new models is the pulsed neural network with radial basis function, a network able to store information in the axonal propagation delay of neurons. Recently, a new method for encoding input-data by population code using gaussian receptive fields has showed interesting results in the clustering task. The present work proposes a function for the unsupervised learning task in this network, which goal includes the simplification of the calibration of the network key parameters and the enhancement of the pulsed neural network convergence to instance based learning. The performance of this model is evaluated for pattern classification, particularly for the pixel colors classification task, in the computer vision domain.
Souza, Andreia Cristina Breda de. "Aproximação fisionômica pericial através de função de base radial hermitiana." Universidade do Estado do Rio de Janeiro, 2014. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9045.
Full textFacial approximation works by building the visual face up from the skull. This method should be performed as last resort, to carry out for missing persons, when there is no other primary identification method avaliable. The purpose of this study was to introduce a new computerized method with hermite radial basis function (HRBF) for facial approximation using dry skull and computed tomography (CT). The same was also evaluated as a result of the recognition. Firstly, a scan of a dry unidentified skull image was used in order to assess if the amount of points would be sufficient for HRBF methodology and subsequent reconstruction of the facial surface. In second, three CT scans of living individuals were used to evaluate the similarity achieved between the real face scanned and facial approximations. An association of different facial structures reconstruction techniques already published for the same region of the face was applied for the same skull. Moreover, some situations from developed facial approximations were simulated, as recognition by a relative or parent, on a face pool-test. Results from the study showed that the purposed methodology can be used for facial approximation. At the three cases a correct approximation identification as one of a few possible matches to the missing person happened. In two of them, the results were consistently better at identifying the correct approximation. In conclusion, the proposed methodology is fast, objective and reaches visual identification. It is possible to perform multiple versions of the same skull, changing the selected data into the system, which maximizes the chances of establishing recognition of the target face. It was also observed that the technique does not need artistic interpretation.
Lay, Alexander Kit. "New π-electron donor systems based on 1,4-dithin derivatives." Thesis, Durham University, 1997. http://etheses.dur.ac.uk/4725/.
Full textLedoux, Valentin. "Matériaux nanocomposites à base d'oxydes conducteurs pour la génération d'énergie électrique en milieux humides et pour de nouvelles applications électrocatalytiques." Thesis, IMT Mines Alès, 2019. http://www.theses.fr/2019EMAL0002.
Full textAn "Unusual" behavior of oxide anodes in aqueous media, compared with metal anodes, began to attract the attention of researchers as early as the 1960s. During the activation process, electrons placed in the valence band (VB) of a semiconductor material leave their energy level and move towards the conduction band (CB) thereby forming electronic holes able to proceed at the direct oxidation of adsorbed hydroxyl anions, thereby transforming them into hydroxyl radicals HO•, which are extremely powerful oxidizing agents. This consideration makes it possible to explain why the oxidation of organic pollutants in water is always higher on the oxide anodes than on the metal anodes. The reaction cycle is as follows:H2O + MOx ["Catalytic" site] MOx•HO•ads + H+ + 1 e- then MOx•HO•ads + RH MOx + H2O + R’Although widely used in electrocatalysis water depollution processes, the mechanism describing the interactions between oxide anodes and water is poorly understood.The ambition of this thesis is to demonstrate the feasibility of recovering electrical charges from water using a metal oxide anode, SnO2:F was chosen as the model anode. The demonstration of this hypothesis follows 5 steps: 1. Understand why water is able to behave as a reducing agent and therefore share its electric charge with external consumers through metal oxide surfaces. 2.Conceptualize the mode of action of oxide anodes in humid environments. Develop a clear vision on the mechanism of this phenomenon, study it in detail and objectively confirm its main stages through experimental results. 3.Conceptualize, from the point of view of chemical compositions as well as physicochemical and electro-physical properties, promising active materials applicable as generators of elementary electrical charges from wetlands. 4.Choose, develop and test appropriate active materials, that is to say, meet the requirements, in terms of chemical compositions and electro-physical properties, fixed in the previous point. 5.Conclude by the proposal of a method of estimating the energy efficiency of the process under development and the prospects of applications