Relevant bibliographies by topics / Trioxan / Dissertations / Theses
To see the other types of publications on this topic, follow the link: Trioxan.

Dissertations / Theses on the topic 'Trioxan'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Trioxan.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Henes, Michael. "Transition metal catalyzed polymerization of 1,3,5-Trioxane Übergangsmetall-katalysierte Polymerisation von 1,3,5-Trioxan /." [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10405642.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Grützner, Thomas. "Entwicklung eines destillationsbasierten Verfahrens zur Herstellung von Trioxan." Berlin Logos-Verl, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2976791&prov=M&dok_var=1&dok_ext=htm.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Lautenschütz, Ludger Peter [Verfasser], and Eckhard [Akademischer Betreuer] Dinjus. "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan / Ludger Peter Lautenschütz ; Betreuer: Eckhard Dinjus." Heidelberg : Universitätsbibliothek Heidelberg, 2015. http://d-nb.info/1180501225/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Laurent, Sophie. "Trioxanes antiparasitaires : mécanisme d’action et nouvelles molécules biologiquement actives." Toulouse 3, 2006. http://www.theses.fr/2006TOU30106.

Full text
Abstract:
L’artémisinine, 1,2,4-trioxane d’origine naturelle, est très active contre le paludisme. La digestion de l’hémoglobine par Plasmodium dans les érythrocytes infectés libère de l’hème-fer(II) capable d’induire, par activation réductrice du peroxyde, une espèce alkylant l’hème lui-même. Nous avons montré que ceci est vrai pour tous les dérivés biologiquement actifs testés de l’artémisinine et pour les trioxaquines®. Les schistosomoses sont dues à un trématode sanguin Schistosoma qui digère l’hémoglobine de l’hôte et forme un agrégat d’hème semblable à celui produit par Plasmodium. Un seul médicament, le praziquantel, est disponible contre les schistosomes ; l’artémisinine est faiblement active contre cette parasitose. Les trioxaquantels, molécules duales formées par liaison covalente entre un trioxane et le fragment pyrazino-isoquinoléine du praziquantel, ont été synthétisées et leur activité biologique évaluée sur souris infectées par S. Mansoni
Artemisinin, a naturally occuring 1,2,4-trioxane, is highly active against multiresistant malaria. Hemoglobin digestion by Plasmodium in infected erythrocytes releases free heme able to induce the reductive activation of the peroxide bond, leading to a C-centered radical able to alkylate heme itself. We have reported that all the biologically active artemisinin derivatives we have tested, and also trioxaquines®, are able to do so. Schistosomiasis are due to a trematode worm, Schistosoma, that digests host hemoglobin and aggegates the released heme in a similar way as Plasmodium does for hemozoin. Praziquantel is currently the single efficient drug against schistosomiasis, and artemisinin is only mildly active. New dual drugs, trioxaquantels, made by covalent bonding between a 1,2,4-trioxane and the pyrazino-isoquinoline fragment of praziquantel, have been synthesized. Their biological activity has been evaluated in mice infected by S. Mansoni
APA, Harvard, Vancouver, ISO, and other styles
5

Dohnal, Petr. "Vnímaní značky Triola." Master's thesis, Vysoká škola ekonomická v Praze, 2007. http://www.nusl.cz/ntk/nusl-2651.

Full text
Abstract:
Práce je zaměřena na vývoj a současné vnímání tradiční značky Triola na českém trhu. Analyzovány jsou vybrané marketingové aktivity, které jsou dle názoru autora pro vnímání značky klíčové. Součástí práce je řada doporučení vedoucích ke zlepšení stávajícího stavu.
APA, Harvard, Vancouver, ISO, and other styles
6

Kerr, Bernadette. "A study of 1,2,4-trioxanes." Thesis, Heriot-Watt University, 1989. http://hdl.handle.net/10399/945.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Pugh, Matthew David. "New methodology for the synthesis of trioxane based antimalarial compounds." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288195.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Johnson, Karen Amanda. "Synthesis of 1,2,4-trioxanes with antimalarial activity." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309172.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Zambrano, Damaris E. "Synthesis, coordination chemistry and hydroformylation catalysis with new trioxa-phospha-adamantane ligands." Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/6f36172a-46df-49af-b24b-be7ffe439b77.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Wachtlová, Dominika. "Optimization of Triola Plc. Loyalty Programme." Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-205717.

Full text
Abstract:
The aim of this thesis is to suggest optimizations for Triola Plc. loyalty program based on theoretical understanding of loyalty and its role in success of a company, as well as numer-ous practical analyses. The thesis is divided into two main parts. The first part overviews the theoretical knowledge about consumer loyalty and how loyalty program can be an ef-fective tool in building said loyalty. The second part is formed of variety of practical anal-yses, including analysis of Triola sales data, data mining analysis using MML-TGI data ana-lyser, consumer survey and lastly benchmarking analysis. The last chapter is a synthesis of the theoretical and practical parts and suggest recommendations for Triola loyalty program based on the insights gathered throughout the whole thesis.
APA, Harvard, Vancouver, ISO, and other styles
11

Dvořáková, Ivana. "Návrh na optimalizáciu internetového predaja Triola a.s." Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-199715.

Full text
Abstract:
This diploma thesis demonstrates the importance of the internet sales in today's world, using an example of the real world company, Triola, which specializes in lingerie manufacturing. Objective of this thesis is behavioral analysis of the company's customers, followed by evaluation of this knowledge which results into recommendations on how to optimize internet sales and how to enhance the design and functionality to achieve this. Analysis and its evaluation are both based on the latest research in this field, which describes the customer's motivation for the internet shopping and the correlation between web design and impulsive shopping. Part of the analysis is also the comparison of trends in behavior of customers all across the world with customers from Czech Republic and with customers of Triola company, trying to identify trends that will likely affect the Triola company in the future. The thesis also comes up with important information about the customers of the Triola company and possible evolution of the internet sales and shows the different approaches for the Triola to take, in order to make internet shopping a pleasant experience for its customers and to raise the internet sales rates as a result.
APA, Harvard, Vancouver, ISO, and other styles
12

Thétiot-Laurent, Sophie. "Trioxanes antiparasitaires : mécanisme d'action et nouvelles molécules biologiquement actives." Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00567140.

Full text
Abstract:
La découverte de l'activité antipaludique et antischistosomose de l'artémisinine, une molécule d'origine naturelle, met en lumière une nouvelle famille de composés actifs : les trioxanes. L'activation réductrice du peroxyde par un centre métallique de bas degré d'oxydation en fait des alkylants efficaces de l'hème. Les propriétés d'alkylation de dérivés de l'artémisinine vis-à-vis de l'hème libéré lors de la digestion de l'hémoglobine par Plasmodium ont été étudiées. Les schistosomoses, maladies dues à un parasite sanguin Schistosoma, sont une des premières causes infectieuses de mortalité au monde, pour lesquelles le praziquantel est le seul médicament disponible. Les schistosomes digèrent l'hémoglobine de l'hôte et forment un pigment d'hème semblable à celui produit par Plasmodium. Les trioxaquantels, molécules duales associant de façon covalente un trioxane à la pyrazino-isoquinoléine du praziquantel, ont été synthétisées et leurs activités biologiques évaluées sur schistosomes.
APA, Harvard, Vancouver, ISO, and other styles
13

Savill, Karen. "Investigations of 1,2,4-trioxanes as precursors of macrocyclic lactones." Thesis, Heriot-Watt University, 1993. http://hdl.handle.net/10399/1392.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Taylor, Benjamin J. "Studies of the thermal rearrangements of dispiro-1,2,4-Trioxanes." Thesis, Heriot-Watt University, 2009. http://hdl.handle.net/10399/2290.

Full text
Abstract:
A series of α-alkoxy-3,6-dispiro-1,2,4-trioxanes have been synthesised by acid-catalysed perhydrolyses of α-alkoxy methylenecyclohexane oxides (provides ring A) to give selectively the corresponding 1-hydroperoxy-1-(hydroxymethyl)cyclohexanes followed by acid-catalysed condensation with an appropriate cycloalkanone (provides ring C). Analogous perhydrolyses catalysed by MoO2(acac)2 afforded mixtures of regioisomeric β-hydroxy hydroperoxides, albeit in overall increased yields. The resulting 1- (hydroperoxymethyl)-1-hydroxycyclohexanes allowed entry to the isomeric 3,5-dispiro- 1,2,4-trioxanes. X-ray crystallographic analysis of the isomeric dispiro-1,2,4-trioxanes revealed that (a) they originate from different diastereoisomers of the epoxide substrates, and (b) the 1,2,4-trioxane rings of the 3,5-isomers adopt distorted half-chair rather than chair conformations as a consequence of intramolecular 1,3-diaxial steric interactions. Modelling studies of the perhydrolysis process are in broad agreement with the regioselectivity of the acid-catalysed reactions, but suggest that the α-alkoxysubstituted epoxides can act as bidentate ligands which can adopt different binding modes to the Mo catalyst and hence provide alternative reaction pathways. Thermolysis of dilute solutions of the α-alkoxy-3,6-dispiro-1,2,4-trioxanes in decane afforded a variety of 13-, 14-, 15- and 20-membered fully ring-expanded keto lactones in high yield via stepwise, β-scission/radical recombination reactions in contrast to the partially ring-expanded oxalactones obtained previously from other 3,6-dispiro-1,2,4- trioxane derivatives. An investigation of substituent effects on the thermal rearrangement mechanisms of 3,6- dispiro-1,2,4-trioxanes using DFT calculations indicated that, after the initial O-O bond homolysis to form the corresponding oxy biradical, ring C generally opens significantly faster than the unsubstituted ring A because of the greater delocalisation of radical character into ring C. In these cases, the lowest rearrangement energy barrier links directly to the partially ring-expanded oxalactone product as observed experimentally. Methyl or methoxy substituents at the α-position of ring A render its ring opening by β- scission increasingly more competitive to that of ring C due to increased delocalisation of radical character onto the α-substituent, consistent with the ‘α-effect’. Methoxysubstituents are also noted to engage in close range interactions with the 1,2,4-trioxane ring. Since the energy barrier for ring A opening falls below that of ring C in the methoxy model, formation of the fully ring-expanded keto lactone becomes favoured.
APA, Harvard, Vancouver, ISO, and other styles
15

Henninot, Jean-François. "Spectroscopie infrarouge dans un jet supersonique : étude de la bande V17 du trioxane (H2CO)3." Lille 1, 1992. http://www.theses.fr/1992LIL10019.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Ilg, Andrea Diane. "The effect of branch density polyoxymethylene copolymers." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1258.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Dahl, Thomas Eva, and Robin Borg. "Automatiserade GUI-tester i praktiken : En fallstudie på Triona AB." Thesis, Högskolan Dalarna, Informatik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:du-34255.

Full text
Abstract:
Testning är en nödvändig men kostsam del av mjukvaruutveckling. Test utförs på olika abstraktionsnivåer och kan vara manuella eller automatiserade. På lägsta abstraktionsnivå, enhetsnivå, är automatiserad testning vanligt och relativt okomplicerat, medan systemtester är svårare att automatisera. I synnerhet gäller detta tester på ett grafiskt användargränssnitt (GUI) som kräver speciella verktyg.   Triona vill undersöka möjligheterna att automatisera regressionstester från GUI:t av sin produkt C-Load, en molnbaserad webbtjänst för avtalsbaserad transportbokning.    Det primära syftet med denna fallstudie är att med en anpassad urvalsprocess utvärdera ett möjligt verktyg i förhållande till C-Load-förvaltningens förväntningar på automatiserad GUI testning (AGT) och att utifrån resultatet föreslå hur C-Loadförvaltningen kan gå vidare med val av verktyg för AGT. För att uppfylla syftet användes litteraturstudier, intervjuer och observationer av praktiska test.    Verktyg för GUI-testning kan delas in i tre huvudkategorier: skriptbaserade, modellbaserade och skriptlösa. Baserat på tidigare forskning drogs slutsatsen att ett skriptbaserat verktyg där koden i testskripten skrivs manuell bäst passar C-Loadförvaltningens krav och förutsättningar. Det mest använda verktyget av denna typ, Selenium WebDriver, utvärderades kvalitativt gentemot identifierade krav.    Av tidigare forskning framgår att vanliga utmaningar med skriptbaserade GUI-tester är att arbetsinsatsen för att skapa och underhålla testskript är stor och att testen kan vara opålitliga. Dessa problem framkom också i studiens intervjuer och observationer.   Slutsatsen är att det vore möjligt att automatisera regressionstester av C-Load med hjälp av Selenium Webdriver, och att det på sikt skulle kunna frigöra tid. Initialt krävs dock en omfattande insats för att implementera automatiserade tester i förvaltningen och Selenium Webdriver uppfyller bara delvis C-Load-förvaltningens förväntningar på AGT. C-Load-förvaltningen rekommenderas att utvärdera fler verktyg innan beslut fattas. I en kommande urvalsprocess bör Triona beakta hur väl olika verktyg fungerar i förhållande till moderna webbramverk.
Testing is a necessary but costly part of software development. Tests are performed at different abstraction levels and can be either manual or automated. On the lowest level of abstraction, where unit testing is performed, automated testing is commonplace and relatively uncomplicated, whereas system testing is more difficult to automate. This is especially true for GUI-testing, which requires special tools.      Triona wished to investigate possibilities to automate regression testing of the GUI for its C-load product, which is a Cloud-based web-service for contract-based transport booking.      The purpose of this case study was to evaluate one tool for automated GUI-testing (AGT) against the C-Load team’s expectations on AGT, and based on the result recommend Triona how to proceed in the process of implementing AGT. Literature studies, observations and interviews were conducted to fulfil the purpose.      GUI-testing tools can be classified into three categories: script-based, model-based and scriptless. One conclusion was that a script-based tool, where test scripts are manually coded would best suit Triona’s needs. The most used tool in that category, Selenium WebDriver, was tested and evaluated against requirements.       Prior research shows that common challenges encountered when using script-based GUItests are the workload required to create and maintain test scripts and that the tests can deliver inconsistent or “flaky” results. These challenges were confirmed during our analysis.       Our conclusion is that it is possible to automate C-Load regression tests with Selenium WebDriver, and that it would eventually free up time. However, a considerable effort is initially required to implement automated testing. Selenium Webdriver only partly fulfills the C-Load team’s expectations on AGT. Before a decision is taken, the C-Load team should evaluate more tools. When evaluating tools for AGT, Triona should take note that Selenium Webdriver can be deficient when it comes to testing applications based on modern web frameworks.
APA, Harvard, Vancouver, ISO, and other styles
18

Camuzat-Dedenis, Boris. "Synthèse de 1,2,4-trioxanes à activité antipaludique : relations structures/activités et mécanime d'action." Paris 11, 2002. http://www.theses.fr/2002PA114830.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Nilsson, Anna. "Identification and Syntheses of Semiochemicals Affecting Mnesampela privata and Trioza apicalis." Licentiate thesis, Mid Sweden University, Department of Natural Sciences, Engineering and Mathematics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-10596.

Full text
Abstract:

The Autumn gum moth, Mnesampela privata (Lepidoptera: Geometridae) is an endemic Australian moth whose larvae feed upon species of Eucalyptus. The moths favorite host plants are E. globulus and E. nitens which are the most important species used in commercial plantations of the Australian pulpwood industry. The autumn gum moth has become one of the most significant outbreak insects of eucalyptus plantations throughout Australia. As a consequence great financial losses to the forest industry occur. Today insecticides such as pyrethroids are used for control of eucalyptus defoliators as M. privata.

The carrot psyllid, Trioza apicalis (Homoptera: Psylloidea), is one of the major pests of carrot (Daucus carota) in northern Europe. The psyllid causes curling of the carrot leafs and reduction of plant growth. Today the carrot crops are protected with the pyrethroid insecticide cypermethrin, which is toxic to aquatic organisms and is, from 2010, prohibited for use in Sweden by the Swedish Chemicals Inspectorate.

An alternative to insecticides is to protect the seedlings with semiochemicals, a chemical substance or mixture of them that carries a message. This thesis describes the identification and the syntheses of semiochemicals from the above mentioned insect species.

From analysis of abdominal tip extracts of M. privata females from Tasmania a blend of (3Z,6Z,9Z)-3,6,9-nonadecatriene and (3Z,6Z,9Z)-3,6,9-heneicosatriene was identified as the sex pheromone of this species. The identification of the C19- and C21-trienes was confirmed by synthesis.

In the analysis of carrot leaf extracts we found a compound, α-cis-bergamotene, that induces antennal response in the carrot psyllid. This is just the beginning of the studies of trying to manipulate this psyllid with semiochemicals instead of insecticides.

APA, Harvard, Vancouver, ISO, and other styles
20

Baldwin, Thomas. "Trion-based Optical Processes in Semiconductor Quantum Wells." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/19728.

Full text
Abstract:
In a semiconductor, negative charge is carried by conduction-band electrons and positive charge is carried by valence-band holes. While charge transport properties can be understood by considering the motion of these carriers individually, the optical properties are largely determined by their mutual interaction. The hydrogen-like bound state of an electron with a hole, or exciton, is the fundamental optical excitation in direct-gap materials such as gallium arsenide and cadmium telluride. In this dissertation, we consider charged excitons, or trions. A bound state of an exciton with a resident electron or hole, trions are a relatively pure manifestation of the three-body problem which can be studied experimentally. This is a subject of practical as well as academic interest: Since the trion is the elementary optical excitation of a resident free carrier, the related optical processes can open pathways for manipulating carrier spin and carrier transport. We present three experimental investigations of trion-based optical processes in semiconductor quantum wells. In the first, we demonstrate electromagnetically induced transparency via the electron spin coherence made possible by the trion transition. We explore the practical limits of this technique in high magnetic fields. In the second, we present a direct measurement of trion and exciton oscillator strength at high magnetic fields. These data reveal insights about the structure of the trion's three-body wavefunction relative to that of its next excited state, the triplet trion. In the last, we investigate the mechanism underlying exciton-correlated tunneling, an optically-controllable transport process in mixed-type quantum wells. Extensive experimental studies indicate that it is due to a local, indirect interaction between an exciton and a hole, forming one more example of a trion-mediated optical process. This dissertation includes previously published co-authored material.
APA, Harvard, Vancouver, ISO, and other styles
21

LEMAIRE, MARIELLE. "Synthese de systemes : 1,4,7,10-tetraoxaspiro-(5,5)-undecane et 1,4,7-trioxa-10-azaspiro-(5,5)-undecane fonctionnalises en 2 et 8." Clermont-Ferrand 2, 1992. http://www.theses.fr/1992CLF21417.

Full text
Abstract:
Dans le cadre des etudes menees au laboratoire sur le mode d'action de la calcymicine (a. 23187) transporteur membranaire du calcium, il est apparu interessant de developper des modeles biomimetiques plus hydrophiles de cet ionophore dont la structure est construite sur le motif 1,7-dioxaspiro (5,5)-undecane. L'objet du present memoire se rapporte uniquement a l'elaboration de nouvelles series de spiroacetals: 1,4,7,10-tetraoxygenes et 1,4,7-trioxygene-10-monoazotes fonctionnalises en 2 et 8. Pour preparer ces systemes, la reaction de spirocyclisation en milieu acide d'un precurseur dihydroxycetonique a ete systematiquement employee. Dans un premier temps, une voie de synthese fondee sur la fonctionnalisation d'une cetone masquee doublement insaturee en bout de chaine, a ete developpee en utilisant reaction d'oxyamination de sharpless. Dans un deuxieme temps, plusieurs voies de synthese ont ete explorees en partant de synthons du type glycerol. Des spiroacetals tetraoxygenes fonctionnalises differemment ou non en 2 et 8 ont ete obtenus. Le choix des precurseurs permet de gouverner la stereochimie e, e et e, z et la chiralite des isomeres en un nombre reduit d'etapes, avec de bons rendements. La resolution asymetrique d'un spiroacetal (+/-) e, e a ete realisee selon deux methodes. Dans un troisieme temps, l'introduction d'un atome d'azote a la place d'un oxygene s'est revelee difficile. Le blocage de cet azote sous la forme d'une fonction amide a permis d'isoler un systeme spiranique 1,4,7-trioxa-10-aza. Une etude structurale approfondie par rmn a ete menee pour caracteriser la structure helicoidale de l'isomere e,e
APA, Harvard, Vancouver, ISO, and other styles
22

Lemeux-Fraitot, Sidonie. "Ut poeta pictor : les champs culturels et littéraires d'Anne-Louis Girodet-Trioson (1767-1824)." Paris 1, 2003. http://www.theses.fr/2003PA010581.

Full text
Abstract:
La richesse du milieu où grandit Girodet et l'éducation soignée qu'il reçue, lui conférèrent une place particulière dans l'atelier de David où il étudia la peinture. Après l'obtention en 1789 du Prix de Rome, il fit au cours de son séjour en Italie, une expérience culturelle et artistique intense qui marqua le reste de sa carrière. Les nombreuses amitiés qu'il noua dans le domaine des lettres (particulièrement Delille, Chateaubriand et la famille Bertin), associées à son tempérament original et à son attrait particulier pour la poésie, déterminèrent sa conception de la peinture, extrêmement intellectuelle, qui lui valut de virulentes critiques. Non content de tenir un des premiers rôles dans les salons comme dans les cercles artistiques, il voulut devenir à son tour poète. Reconnu comme chef de file du néoclassicisme à partir de 1819, il devint, en vertu de ses désirs synestésiques et de sa personnalité, un modèle d'inspiration pour les écrivains de la génération romantique.
APA, Harvard, Vancouver, ISO, and other styles
23

Streit, Hans Max. "Hydrolytische Vernetzung von Eisen (III) ausgehend von Komplexen mit Di- und Triolen in methanolischer Lösung /." [S.l.] : [s.n.], 1987. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8281.

Full text
APA, Harvard, Vancouver, ISO, and other styles
24

Vargas, Pâmela Schütz de. "Síntese de 1-aril-4-[(dimetilamino)metileno] pirrolidino-2,3,5-trionas utilizando irradiação de micro-ondas." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/10489.

Full text
Abstract:
Conselho Nacional de Desenvolvimento Científico e Tecnológico
The synthesis of a series of 1-aryl-4-[(dimethylamino)methylene] pyrrolidine- 2,3,5-trione from the cyclocondensation reaction between b-enaminodiketone [Cl3C(O)C(=CHNMe2)C(O)CO2Et] and aniline derivatives [R = Ph, 3-Me-C6H4, 3- MeO-C6H4, 3-HO-C6H4, 4-Me-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, 4- MeCO-C6H4] was performed. The reaction conditions used to synthesize the pyrrolidine-2,3,5-triones involved environmentally benign techniques, as the use of microwave irradiation, employing the reactants b-enaminodiketone and amine in a molar ratio of 1:1.1, respectively, and a non-halogenated solvent. The reaction was carried out with short time (12-16 min) and the products were obtained in moderate to good yields (50- 76%). In addition, the advantages of using the microwave irradiation method in comparison to the conventional thermal heating were demonstrated.
A síntese de uma série de 4-(dimetilamino)metileno-1-aril-pirrolidino-2,3,5-triona foi realizada a partir da reação de ciclocondensação da b-enaminodicetona [Cl3C(O)C(=CHNMe2)C(O)CO2Et] com derivados da anilina [R = Ph, 3-Me-C6H4, 3- MeO-C6H4, 3-HO-C6H4, 4-Me-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, 4- MeCO-C6H4]. As condições reacionais utilizadas para a síntese das pirrolidino-2,3,5- trionas envolveram técnicas ambientalmente corretas, como o uso de irradiação de micro-ondas, empregando uma relação molar da b-enaminodicetona e da amina de 1:1.1, respectivamente e solvente não halogenado. A reação foi realizada em curtos períodos de reação (12-16 min) e os produtos foram obtidos com rendimentos de moderados a bons (50-76%). Além disso, foram demonstradas as vantagens da utilização do método de irradiação de micro-ondas sobre o método convencional de aquecimento térmico.
APA, Harvard, Vancouver, ISO, and other styles
25

Maxwell, John Patrick. "Part I. design, synthesis, and evaluation of antimalarial 1,2,4-trioxanes Part II. ketone enolate-epoxide openings /." Available to US Hopkins community, 2002. http://wwwlib.umi.com/dissertations/dlnow/3068183.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

GARCIA, CHRISTOPHE. "Synthese d'ethers-couronnes et de cryptants chiraux incorporant des unites 1,4,7,10-tetraoxaspiro5,5undecane ou 1,4,7-trioxa-azaspiro5,5undecane. Proprietes de complexation et de reconnaissance chirale." Clermont-Ferrand 2, 1998. http://www.theses.fr/1998CLF22025.

Full text
Abstract:
La conception et la synthese de systemes multidentes, macrocycliques ou en chaines ouvertes, susceptibles de s'associer specifiquement avec d'autres especes moleculaires ou ioniques, est devenue un vaste domaine de recherche dont l'evolution conduit a la realisation de modeles de plus en plus elabores. Nous avons entrepris l'etude de composes macrocyclique, optiquement actifs, dont la chiralite est liee a une jonction de cycle spiranique. Vingt-six macrocycles originaux incorporant dans leur structure le squelette (+)1,4,7,10-tetraoxaspiro5. 5undecane, ou (+)-1,4,7-trioxa-10-azaspiro5. 5undecane, ont ainsi ete obtenus, avec des tailles, des fonctions et des symetries differentes. Les syntheses, conduites a partir du synthon a trois carbones (s)-solketal, necessitent selon la complexite des structures entre cinq et douze etapes. Dix-huit ethers-couronnes, cinq macrobicycles du type cryptant et trois bis-azamacrocycles ont ete isoles et caracterises. A noter que lors des macrocyclisations effectuees pour obtenir les ethers-couronnes, quatre dimeres provenant d'une condensation 2+2 ont ete obtenus. L'etude de la complexation des ions alcalins, alcalino-terreux et ammonium a ete realisee dans le thf, par spectrophotometrie uv-visible. Certains des ligands montrent de bonnes proprietes d'association, notamment avec l'ion ammonium. La structure chirale des macrocycles impliquait d'explorer egalement leurs proprietes d'association avec des amines protonees portant un groupement asymetrique. Les experiences realisees sur les enantiomeres de la phenylglycine (ester methylique) et du phenylglycinol, par spectrometrie de masse a source electrospray, mettent en evidence des differences marquees dans la reconnaissance des enantiomeres, notamment pour les ligands de symetrie c#2. Ce resultat totalement original est tres interessant. Ces resultats situent certains de ces ligands parmi les plus efficaces dans la palette des composes deja etudies.
APA, Harvard, Vancouver, ISO, and other styles
27

But, Diana [Verfasser]. "Reaktivität von cyclischen Olefinen mit Singulett-Sauerstoff und Entdeckung eines neuen Synthesewegs zu 1,2,4-Trioxanen / Diana But." München : Verlag Dr. Hut, 2020. http://d-nb.info/1219470767/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
28

Tolon, Murguia Blanca Idelmis. "Sintesis de compuestos del tipo benzoilfloroglucinol poliprenilados : Estudios de formacion del sistema biciclo [3.3.1] nonano-2,4,9-triona." Paris 11, 2010. http://www.theses.fr/2010PA112147.

Full text
Abstract:
Cette thèse concerne les études réalisées en vue d’effectuer la synthèse de benzoylphloroglucinols polyprénylés et, plus particulièrement, la construction du système bicyclo[3. 3. 1]nonane-2,4,9-trione qui constitue le cœur cyclique de ces composés appartenant à la classe plus générale des acylphloroglucinols polycycliques polyprénylés (PPAPs). Différentes stratégies ont été envisagées en partant d’abord d’un composé modèle: la 2,6-diprénylcyclohexanone. Pour la formation du bicycle ponté, une réaction d’aldolisation stéréosélective impliquant le réarrangement réductif d’une lactone d’énol a été utilisée. Par ailleurs, une méthode originale faisant appel à une séquence addition de Michael-aldolisation intramoléculaire, mettant en jeu la cyclohexanone diprénylée et l’acroléine, a pu être mise au point. L’aménagement fonctionnel, afin d’obtenir le degré d’oxydation désiré, a été effectué via une transformation directe de cétone en énone par l’IBX, suivie d’époxydation et de réduction en cétol. L’oxydation de ce dernier en composé béta-dicarbonylé s’est révélée très difficile, et ce, malgré l’utilisation de nombreux réactifs. Ce travail est également caractérisé par la réalisation de la synthèse efficace d’une cyclohexanone convenablement substituée (avec trois groupes prényle et un gem-diméthyle), en vue d’accéder aux PPAPs. L’analogue triallylé, préparé dans le but d’éviter certaines cyclisations acidocatalysées non desirées ayant été observées dans un travail précédent, a permis l’accès inattendu au cœur tricyclique de PPAPs atypiques, via une annélation d’Effenberger (double acylation d’un éther d’énol silylé avec le chlorure de malonyle)
In this thesis are reported studies concerning the synthesis of polyprenylated benzoylphloroglucinols and, more specially, the construction of the bicyclo[3. 3. 1]nonane-2,4,9-trione system which corresponds to the cyclic core of these compounds belonging to a more general class of natural products: the polycyclic polyprenylated acylphloroglucinols (PPAPs). Several strategies were envisaged, first starting from a model compound: 2,6-diprenylcyclohexanone. For the formation of the bridged bicycle, a stereoselective aldolization reaction involving the reductive rearrangement of an enol lactone was used. Moreover, an original method, via a sequence Michael addition of the diprenylated ketone onto acrolein followed by an intramolecular aldolization, was developed. To get the correct oxidation level, the direct transformation of a ketone into an enone with IBX, followed by epoxidation and reduction into a ketol, was achieved. However, oxidation of the latter into a beta-dicarbonyl compound proved very difficult, even though the use of numerous reagents. This work can also be characterized by the achievement of the efficient synthesis of a suitably substituted cyclohexanone (with three prenyl groups and a gem-dimethyl), in order to access PPAPs. The triallylated counterpart, prepared with the aim of avoiding some undesired acid catalyzed cyclizations which have been precedently observed, allowed the unexpected access to the tricyclic core of atypical PPAPs, via an Effenberger annelation (double acylation of a silyl enol ether with malonyl chloride)
APA, Harvard, Vancouver, ISO, and other styles
29

Laurent, Sabine. "Orientation optique et relaxation du spin du trion dans les boîtes quantiques d'InAs/GaAs." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00007028.

Full text
Abstract:
Le spin électronique dans les semi-conducteurs fait actuellement l'objet de nombreuses investigations. Il pourrait en effet constituer, en tant que système quantique à 2 niveaux, l'élément de base d'un futur ordinateur quantique: un quantum-bit. Une des limites physiques d'un tel ordinateur provient en premier lieu de la décohérence de la superposition des états up et down de ce quantum-bit. La problématique est donc d'obtenir un système dans lequel ce temps de cohérence soit suffisamment long pour permettre de futures manipulations quantiques. Dans ce contexte, les boîtes quantiques semi-conductrices chargées avec un seul électron se présentent comme des candidats prometteurs. Ces systèmes, de part leur dimensions nanométriques, ont en effet la propriété de posséder une structure électronique discrétisée, ce qui supprime les principaux mécanismes responsables de la relaxation du spin. Ce travail de thèse tend donc à déterminer le temps de relaxation du spin dans une boîte.
APA, Harvard, Vancouver, ISO, and other styles
30

Collins, Megan Marie. "The Portrait of Citizen Jean-Baptiste Belley, Ex-Representative of the Colonies by Anne-Louis Girodet Trioson: Hybridity, History Painting, and the Grand Tour." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1237.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Higley, Morgan Yonan Michael Elia. "The developing child in three portraits by Anne-Louis Girodet." Diss., Columbia, Mo. : University of Missouri-Columbia, 2009. http://hdl.handle.net/10355/6728.

Full text
Abstract:
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 19, 2010). Thesis advisor: Dr. Michael Yonan. Art work removed from thesis by author. Includes bibliographical references.
APA, Harvard, Vancouver, ISO, and other styles
32

Vilcachagua, Janaina Dantas. "Interações de orbitais e seus efeitos nos acoplamentos 'J SOB.2. J IND H' e 'J SOB.1 J IND CH' em 1, 3, 5-trioxano, 1, 3, 5-tritianos monosubstituidos : um estudo teorico e experimental." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249194.

Full text
Abstract:
Orientador: Roberto Rittner Neto
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
Made available in DSpace on 2018-08-08T22:55:18Z (GMT). No. of bitstreams: 1 Vilcachagua_JanainaDantas_M.pdf: 7602676 bytes, checksum: c8ad06bb13f22f25be4a54757dfeb0e2 (MD5) Previous issue date: 2007
Resumo: Estudaram-se as interações de orbitais e seus efeitos nas constantes de acoplamento JHH e JCH em 1,3,5-trioxano, 1,3,5-tritiano e 1,3,5-tritianos monosubstituídos, onde os substituintes foram os halogênios: flúor, cloro, bromo e metil por dados de ressonância magnética nuclear e cálculos teóricos. Todos os cálculos foram realizados com os programas GAUSSIAN 98 e 03. Os cálculos de otimização de geometrias foram realizados em nível MP2 e a função de base aug-cc-pVTZ. Os cálculos para estudo das interações hiperconjugativas foram feitos com o programa NBO. As constantes de acoplamento foram calculadas utilizando a teoria de perturbação CP-DFT. Obtiveram-se os espectros de RMN de H e de C a temperatura ambiente e a baixa temperatura para obtenção dos valores das constantes de acoplamentos experimentais. A análise conjunta dos dados teóricos e experimentais para o 1,3,5-trioxano e 1,3,5-tritiano mostrou a influência das interações hiperconjugativas nxs*C-HEq, nxs*C-HAx, e nxs*C-X, onde o X pode ser o átomo de oxigênio ou enxofre, nos valores das constantes de acoplamento JCHax, JCHeq e JHH. A análise conjunta dos dados teóricos e experimentais para 1,3,5-tritianos monosubstituídos mostrou a influência dos átomos eletronegativos, flúor, cloro e bromo, no valor da constante de acoplamento JCHax no carbono 6 através do efeito eletrostático. As constantes de acoplamento JCHax e JCHeq, no carbono 2, sofrem influência direta do substituinte eletronegativo. A presença do grupo metila não mostrou nenhum efeito nos valores das constantes de acoplamento estudadas.
Abstract: The present work reports the NMR data and theoretical calculations of orbital interactions and their effects on JHH and JCH coupling constants in 1,3,5-trioxane, 1,3,5- trithiane and 2-substituted 1,3,5-trithianes, where the substitutents are fluorine, chlorine, bromine and methyl. The calculations were carried out with the Gaussian 98 and 03 package of programs. The aug-cc-pVTZ basis sets were employed for geometries optimizations at level MP2. The energies of hyperconjugative interactions were calculated with the NBO program. The coupling constants were evaluated within the CP-DFT perturbative approach. The H and C spectra were recorded for all compounds at room and low temperature, for obtained the determination of coupling constants. The experimental results and those from theoretical calculations showed the influence of hyperconjugative interactions nxs*C-HEq, nxs*C-HAx, e nxs*C-X, where X is oxygen or sulfur atoms, on JCHax, JCHeq and JHH coupling constants in 1,3,5-trioxane and 1,3,5-trithiane. The experimental results and those from theoretical calculations showed the influence of electrostatic effects for JCHax coupling constant in 2-substituted 1,3,5-trithianes with electronegative atoms: fluorine, chlorine and bromine. For carbon 2, the JCHax and JCHeq coupling constants showed the direct influence of the electronegative atom. The alkyl group, methyl, did not present any effects on the coupling constants in study.
Mestrado
Quimica Organica
Mestre em Química
APA, Harvard, Vancouver, ISO, and other styles
33

Aidoo, Owusu Fordjour [Verfasser]. "Bio-ecology of the African citrus triozid Trioza erytreae Del Guercio (Hemiptera: Triozidae) on citrus in Kenya : implication for its management / Owusu Fordjour Aidoo." Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1185636277/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Rubin, Andreas. "IF Trions hemsida." Thesis, Blekinge Tekniska Högskola, Avdelningen för telekommunikationssystem, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3283.

Full text
Abstract:
Detta är rapporten för hur IF Trions hemsida kom till och utvecklades. Från det att iden kläcktes tills det att hemsidan var helt färdigställd. Arbetet bygger mycket på de olika säkerhetsbrister som en hemsida kan ha, till exempel hur lösenord ska hanteras. Med avseende på detta så ingår ett avsnitt i rapporten om de vanligaste säkerhetsproblem som man kan tänkas stöta på under uppbyggnadsfasen och exempel på hur man kan lösa dem. PHP är det programmeringsspråk som IF Trions hemsida är kodat med. För att göra det lättare att välja vilket programmeringsspråk man ska använda sig av när man ska börja koda en hemsida så ingår ett kapitel som tar upp fördelar och nackdelar om PHP och ASP. Detta är de två ledande programmeringsspråken för producering av hemsidor.
APA, Harvard, Vancouver, ISO, and other styles
35

Sahabo, Nina Carole. "Novel sugar phosphorus ylides : their synthesis, structure and reactivity : synthesis of a series of sugar-derived phosphorus ylides from protected sugar derivatives and beta-oxo ylides as a route to novel alkynes and trioxo compounds." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/4417.

Full text
Abstract:
Higher carbon chain sugars have gained increased interest recently; they are important building blocks of natural and unnatural products with biological properties. The synthesis of these higher sugar skeletons is commonly known to be achieved with the Wittig methodology which exploits phosphorus ylide chemistry. This method has been successfully used for the synthesis of the higher carbon sugars. The aim of this project was to synthesise ß,ß'-dioxo sugar-derived phosphorus ylides, a new class of ylides, as versatile intermediates to valuable higher carbon sugar derivatives and carbohydrate mimics. Model reactions were initially conducted; tetrahydro-2-furoic acid and tetrahydro-2H-pyran-4-carboxylic acid, compounds which are structurally similar to the precursor sugars, were identified as suitable model compounds. These compounds were converted to acyl chlorides and then converted to ß,ß'-dioxo phosphorus ylides precursors by acylation. The methodology proved successful and 8 examples were isolated. However, low yields were obtained due to the inevitable formation of triphenylphosphine oxide. The method was then extended to sugar derivatives, prepared using standard protecting group chemistry. It was found that acylation could be achieved using the simple acyl chloride route or peptide coupling methodology for sugar derivatives which were acid sensitive. ß,ß'-dioxo sugar-derived phosphorus ylides (16 examples) were successfully isolated in low yields. The oxidation and thermal reactivity of the ß,ß'-dioxo ylides were studied. Oxidation resulted in the successful synthesis of vicinal tricarbonyls, isolated as a mixture with the gem-diols (hydrates). The thermal decomposition of the ylides gave alkynes in moderate yields.
APA, Harvard, Vancouver, ISO, and other styles
36

Silva, Daniel Leite da. "Calix[n]arenos como catalisadores em reações orgânicas : síntese e triagem da atividade antiproliferativa in vitro em células tumorais humanas de xantenonas e ftalazinas-triona." Universidade Federal de Minas Gerais, 2015. http://hdl.handle.net/1843/SFSA-9VDLPQ.

Full text
Abstract:
Calix[n]arenes, macrocyclic compounds of phenolic units linked by methylene groups at 2,6-positions, are widely used as ligands for obtaining organometalic catalysts. Their use as catalysts in absence of metals is, however, poorly explored. This study focused on the synthesis of six calix[n]arenes and their possible use as catalysts in the synthesis of xanthenones and phthalazines. In the synthesis of xanthenones, p-sulfonic acid calix[4]arene (1.5 mol% in the absence of solvents) exhibited the highest catalytic efficiency in 1 h-reaction performed with various aromatic aldehydes, -naphthol (or 3,4-methylendioxyfenol) and 1,3-dicarbonyl compounds. Xanthenones were obtained with moderate to good yields (55- 92%). This approach allowed obtaining 59 xanthenones that were further investigated for the antiproliferative activity in vitro against human cancer cells. Among xanthenones, compound 12-(4-hydroxy-3,5-dimethoxyphenyl)-10,10-dimethyl-9,10- dihydro-8H-benzo[a]xanthen-11(12H)-one (41) presented a broad spectrum of action when used at 10 g/mL, while compound 9,9-dimethyl-12-phenyl-9,10-dihydro-8Hbenzo[ a]xanthen-11(12H)-one (5) (GI50 = 0,027 g/mL) was as potent as the reference drug doxorubicin (GI50 = 0,024 g/mL) against drug-resistant ovarian (NCI-ADR/RES) cancer cells. A quantitative structure-activity relationship (QSAR) study was performed and two QSAR models were obtained for compounds of Group 1 against U251 and NCI-H460 cells and indicated that the biological activity of compounds increased with increasing accessible surface area of hydrogen bond donor atoms. In the synthesis of phthalazines, p-sulfonic acid calix[4]arene (1.5 mol% in ethyl lactate) exhibited the highest catalytic efficiency after 10 min of reaction (under microwave irradiation) performed with various aromatic or non-aromatic aldehydes, phthalhydrazide and dimedone. Aromatic aldehydes provided better yields (31-94%) than did non-aromatic ones (11-35%). This approach allowed obtaining 14 phthalazines that were further investigated for the antiproliferative activity against human cancer cells. In general, these compounds proved to be little activity against the tested strains. Phthalazine 3,3-dimethyl-3,4-dihydro-1H-indazolo[2,1-b]phthalazine-1,6,11(2H,13H)- trione (76) was the most promising, with active against drug-resistant ovarian (NCIADR/ RES) and leukemia (K562) cancer cells. The physicochemical properties calculated for the phthalazines-triones shown that this class of compounds can be identified as promising for the development of compounds with antriproliferative activity, however, it is necessary to the synthesis of new structural analogues for a more detailed study of the potential of this class of substances.
Calix[n]arenos, macrociclos constituídos de unidades fenólicas ligadas por unidades metilênicas, são amplamente empregados como ligantes para a construção de catalisadores organometálicos. Porém, o uso destes macrociclos em catálise na ausência de núcleos metálicos é ainda pouco explorado. Este estudo visou à síntese de seis calix[n]arenos e seus possíveis empregos como catalisadores nas sínteses de xantenonas e ftalazinas. Na síntese das xantenonas, o ácido p-sulfônico calix[4]areno (1,5 mol% na ausência de solvente) apresentou maior eficiência catalítica após 1 hora de reação frente a diferentes aldeídos aromáticos, ß-naftol (ou 3,4-metilenodioxifenol) e compostos 1,3-dicarbonílicos. As xantenonas foram obtidas com rendimentos de 55-92%. Esta metodologia permitiu a obtenção de 59 xantenonas, que foram testadas frente à atividade antiproliferativa de células tumorais humanas in vitro. Dentre as xantenonas, avaliadas o composto 12-(4-hidroxi-3,5-dimetoxifenil)-10,10-dimetil-9,10-diidro-8Hbenzo[a]xanten-11(12H)-ona (41) foi o que apresentou o maior espectro de ação quando empregado a 10 µg/mL, enquanto que o composto 9,9-dimetil-12-fenil-9,10-diidro-8H-benzo[a]xanten-11(12H)-ona (5) (GI50 = 0,027 µg/mL) foi tão potente quanto o fármaco-referência doxorrubicina (GI50 = 0,024 µg/mL) contra as células de câncer de ovário-resistente (NCI-ADR/RES). Um estudo de relações quantitativas entre estrutura e atividade (QSAR) foi realizado e dois modelos de QSAR foram obtidos para os compostos do Grupo 1 frente as células de glioma (U251) e células não-pequenas de pulmão (NCI-H460), indicando que a atividade biológica dos compostos é dependente da área superficial acessível dos átomos doadores de ligação de hidrogênio. Na síntese das ftalazinas, o ácido p-sulfônico calix[4]areno (1,5 mol% em lactato de etila) apresentou maior eficiência catalítica após um período de reação de 10 minutos (sobre irradiação de micro-ondas) entre diferentes aldeídos (aromáticos e nãoaromáticos), ftalidrazida e dimedona. Aldeídos aromáticos proporcionaram melhores rendimentos (31-94%) que os não-aromáticos (11-35%). Esta metodologia permitiu a obtenção de 14 ftalazinas, que foram testadas frente à atividade antiproliferativa de células tumorais humanas. Em geral, esses compostos mostraram-se pouco ativos contra as linhagens avaliadas. Dentre as ftalazinas-trionas testadas, o composto 3,3-dimetil-2,3,4,13-tetraidro-1H-indazolo[1,2-b]ftalazina-1,6,11-triona (76) foi o mais promissor, sendo ativo frente as linhagens de ovário resistente a múltiplos fármacos (NCIADR/RES) e leucemia (K-562). As propriedades físico-químicas calculadas para as ftalazinas-trionas mostraram que esta classe de compostos pode ser apontada como promissora para o desenvolvimento de compostos com atividade antriproliferativa, entretanto, faz-se necessário a síntese de novos análogos estruturais para um estudo mais detalhado do potencial desta classe de substâncias.
APA, Harvard, Vancouver, ISO, and other styles
37

Koh, Adam Byunghoon. "Black Dionysus classical iconography and its contemporary resonance in Girodet's Portrait of Citizen Belley /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 84 p, 2008. http://proquest.umi.com/pqdweb?did=1605135741&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Biadala, Louis. "Propriétés optiques de nanocristaux de CdSe/ZnS individuels à basse température." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00654493.

Full text
Abstract:
Les nanocristaux de CdSe font l'objet d'applications émergentes dans les domaines de la nanoélectronique, des technologies laser ou du marquage fluorescent de biomolécules. Pour ces applications, la détermination de la structure fi…ne de l'exciton de bord de bande et des mécanismes de relaxation entre sous-niveaux est d'un intérêt majeur. Cette thèse a été consacrée à l'étude spectroscopique à basse température et sous champ magnétique de nanocristaux individuels de CdSe/ZnS. La remarquable photostabilité des nanocristaux étudiés a permis de caractériser les propriétés optiques des deux états excitoniques de plus basse énergie : l'état excitonique fondamental noir, et l'état excitonique brillant situé quelques meV plus haut en énergie. Ces études ont aussi permis d'identi…er un état excitonique chargé (trion) et de caractériser ses propriétés photophysiques. La possibilité de générer une cascade radiative biexciton-exciton a également été démontrée dans ces systèmes.
APA, Harvard, Vancouver, ISO, and other styles
39

La, Pensée Louise Josephine Ilse. "Endoperoxides as antimalarials and the application of singlet oxygen to the synthesis of key intermediaries en route to synthetic 1,2,4-trioxanes and synthesis and biological activity of minor groove binding-artemisinin conjugates." Thesis, University of Liverpool, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533991.

Full text
APA, Harvard, Vancouver, ISO, and other styles
40

Yuma, Bertrand Kei. "Etude de la dynamique des états excités des nanotubes du carbone mono-paroi." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-00994244.

Full text
Abstract:
Ce travail analyse la formation d'états liés par interaction coulombienne d'excitons dans un ensemble de nanotubes de carbone de chiralité (6,5) en solution. Sous l'action d'une impulsion laser de forte intensité, une grande densité d'excitons est formée dans le nanotube et conduit à la formation d'état de trion et de biexciton. Les mécanismes physiques responsables de la photogénération de ces états ont été analysés dans le cadre de cette thèse. Ces travaux sont effectués à l'aide d'une expérience pompe-sonde dans laquelle le faisceau sonde est un continuum de lumière blanche permettant ainsi l'observation simultanée des états d'exciton, de trion et de biexciton. Cela conduit à l'obtention des énergies de liaison des différentes contributions excitoniques. En outre la dynamique de ces états excitoniques a aussi pu être obtenue avec une résolution temporelle de l'ordre de la centaine de femtosecondes.
APA, Harvard, Vancouver, ISO, and other styles
41

Sinito, Chiara. "Propriétés magnéto-optiques de nanocristaux de CdSe individuels à basse température." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0282/document.

Full text
Abstract:
Les applications émergentes des nanocristaux de CdSe nécessitent une compréhension approfondie des propriétés d’émission et de relaxation des sous-niveaux de structure fine de l’exciton de bord de bande. Cette thèse porte sur l’étude spectroscopique de nanocristaux individuels de CdSe présentant une photostabilité remarquable aux températures cryogéniques. La distribution spectrale de leur photoluminescence en fonction de la température et d’un champ magnétique appliqué fournit une signature précise des niveaux de plus basse énergie, révélatrice de leur morphologie et leur structure cristalline. Une méthode d’excitation de la luminescence de haute résolution spectrale a été développée pour sonder la totalité des niveaux de structure fine. Les raies de recombinaison des huit états ont ainsi été résolues pour la première fois dans une situation de levée totale de dégénérescence produite par l’anisotropie des nanocristaux et l’application d’un champ magnétique. L’excitation sélective des nanocristaux dans les niveaux supérieurs de la structure fine permet aussi d’étudier les mécanismes de relaxation de spin entre les branches excitoniques à trou lourd et à trou léger. Des canaux de relaxation sélectifs peuvent notamment être mis à profit pour préparer un nanocristal dans un niveau quantique unique.Des nanocristaux à double coque ont été conçus pour être efficacement photo-chargés, produisant une émission stable à partir de l’exciton chargé (trion) à la température de l’hélium liquide. La recombinaison du trion est purement radiative, avec une signature spectrale caractérisée par une raie d’émission sans phonon unique et intense. Sous champ magnétique, son éclatement en quatre composantes Zeeman livre les facteurs de Landé de l’électron et du trou. L’analyse des poids de ces composantes permet aussi de trouver le taux de relaxation de spin du trion et le signe de sa charge. Une inhibition remarquable de la relaxation de spin se produit lorsque l’éclatement Zeeman est inférieur à l’énergie du premier mode de phonons acoustiques du nanocristal
The development of emerging applications of CdSe nanocrystals requires a detailed understanding of the band-edge exciton fine structure and relaxation pathways. This thesis is focused on cryogenic spectroscopy of single nanocrystal with a remarkable photostability. Photoluminescence spectra as a function of temperature and under external magnetic fields provide a spectral fingerprint of the low energy sub-levels, revealing the morphology and the crystal structure of individual nanocrystals. In order to probe the entire band-edge exciton fine structure, a high resolution luminescence excitation technique has been developed. Zeeman and anisotropy-induced splittings are used to reveal the entire 8-state band-edge fine structure, enabling complete comparison with band-edge exciton models. State selective excitation allows the preparation of single quantum states. It is also used to map the hole spin relaxation pathways between the fine structure sub-levels.Charged quantum dots provide an important platform for a range of emerging quantum technologies. Double shell CdSe nanocrystals are engineered to efficiently ionize at cryogenic temperatures, resulting in trion emission with a single sharp zero-phonon line and a near-unity quantum yield. Zeeman splitting of this line enables direct determination of electron and hole g-factors. Spin relaxation is observed in high fields, enabling identification of the trion charge. Importantly, we show that spin flips are completely inhibited for Zeeman splittings below the low-energy bound for confined acoustic phonons. This charac- teristic unique to colloidal quantum dots has potential applications in single spin coherent manipulation
APA, Harvard, Vancouver, ISO, and other styles
42

Palmero, Béatrice. "Communautés, enjeux de pouvoir et maîtrise de l'espace pastoral aux confins du comté de Nice (Tende, La Brugue et Triora) à l'époque moderne : une approche micro-historique : les Alpes de proximité." Aix-Marseille 1, 2005. http://www.theses.fr/2005AIX10087.

Full text
Abstract:
L'histoire de l'utilisation pastorale de l'espace alpin des communautés montagnardes concerne le procès de construction de l'espace pastoral. Un regard régressif aux "usi civici" et aux délimitations des confins administratifs des communes limitrophes nous a conduit à individuer des procès historiques de construction de cet espace alpin. Alors, autour des droits territoriaux, l'espace pastoral se réorganise en Alpes de proximité (XIVe-XVIe siècles) et pâturages de confins (XVIIe-XVIIIe siècles). De plus, l'utilisation moderne des Alpes est intéressée directement par un autre procès : l'accensement du territoire communautaire. La répartition en lots du patrimoine pastoral et la redistribution des rentes territoriales nous permet d'expliquer les formes de la propriété collective et des groupes issus autour du pâturage.
APA, Harvard, Vancouver, ISO, and other styles
43

Spink, Graham George. "Application of quantum Monte Carlo methods to homogeneous electron and electron-hole systems." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/275725.

Full text
Abstract:
The properties of the macroscopic world around us, and of which we are a part, are largely determined by the low energy, collective behaviour of many interacting particles, including the nuclei and, especially, the electrons present. Although the fundamental laws governing the behaviour of these many-body systems are believed to be known in principle, the practical solution of the equations of quantum mechanics remains a challenging area of research. This thesis is concerned with the application of quantum Monte Carlo methods to two model systems: the spin-polarised homogeneous electron gas, and a hole-doped electron gas. Electronic structure theory is briefly reviewed before discussing in more detail the quantum Monte Carlo methods used in this thesis. A study of the three-dimensional spin-polarised homogeneous electron gas (HEG) is then reported, where the relatively new technique of twist averaging is investigated in detail and accurate energies and pair correlation functions are obtained over densities $r_s = 0.5 – 20$ a.u. and the full range of spin-polarisation, allowing comparison with the Perdew-Zunger interpolation scheme used in local spin density approximation exchange-correlation functionals. Following this, an impurity is added to the electron gas in the form of a positively charged hole, and the interaction is studied. Relaxation energies, pair correlation functions and momentum densities are reported. Trion formation is observed over a range of carrier densities and electron-hole mass ratios in agreement with experiment. Isolated trions are also studied, where the diffusion Monte Carlo method is exact. Methodological innovations developed while carrying out this work are discussed, including a variance reduction technique for twist-averaged calculations and a new trial wave function for impurity-in-HEG calculations.
APA, Harvard, Vancouver, ISO, and other styles
44

Eble, Benoît. "Interaction hyperfine dans les boîtes quantiques d'InAs/GaAs sous pompage optique orienté." Paris 6, 2006. https://tel.archives-ouvertes.fr/tel-00197618.

Full text
APA, Harvard, Vancouver, ISO, and other styles
45

Momeni, Anouchah. "Etude expérimentale des processus multi-électroniques lors de collisions d'ions en incidence rasante sur une surface de LiF(001)." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00261608.

Full text
Abstract:
Ce manuscrit présente différentes études expérimentales des collisions en incidence rasante (< 3 degrés) sur LiF(001) d'ions simplement chargés tels que le néon et le fluor de basses énergies (< 3 keV). Le faisceau incident est pulsé. Le produit de la diffusion après une analyse en charge entre des plaques électrostatiques est détecté sur un détecteur sensible en position. Les particules secondaires (électrons ou ions) sont recueillies sur un détecteur composé de 16 unités de détection (2 galettes microcanaux) couvrant 2p stéradian au dessus de la surface. La technique de mesure de perte d'énergie (spectroscopie de translation) associée à la détection des particules diffusées en coïncidence avec les électrons émis de la surface lors de la collision d'ions néons simplement chargés, a permis de mettre en évidence des états excités de la surface. Ces états excités, localisés sur les ions fluors négatifs de la surface, sont soit centrés autour d'une seule lacune (les excitons), soit autour de 2 lacunes, ce dernier, complexe à 3 corps est connu dans la littérature sous le nom de trion. On trouvera dans ce manuscrit la première caractérisation de ces états par impact d'ions. Dans le cas du néon la capture correspond à une neutralisation Auger Les collisions d'atomes de fluors ont confirmé l'existence d'un seuil en vitesse, lors de la formation des ions négatifs. La formation de ces ions à partir d'ions positifs sous ce seuil, donne une preuve expérimentale d'une double capture simultanée. La valeur de la perte d'énergie s'explique correctement si l'on tient compte de l'interaction entre les deux lacunes voisines. La corrélation statistique se double donc d'une corrélation spatiale où les captures d'électrons s'effectuent sur deux sites halogènes voisins. Dans ce cas l'expérience ne permet pas de différencier un processus di-électronique d'un processus mono-électronique du second ordre alors que la théorie semble indiquer qu'il s'agit de processus du second ordre.
APA, Harvard, Vancouver, ISO, and other styles
46

Musil, Tomáš. "Hybridní mikrofonní předzesilovač s plynulou volbou technologie zesilovače." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318183.

Full text
Abstract:
This diploma thesis deals with a basic description of dynamic and condenser microphone, its performance regarding polar patterns and a type of mechanical construction. It also describes a principle of operation of a triode. The thesis deals with selecting of a suitable type of microprocessor to control microphone preamplifier functions. Last part contains a power supply and microphone preamplifier circuits design using a semiconductor and vacuum tube technology.
APA, Harvard, Vancouver, ISO, and other styles
47

Toorawa, Parveen. "La maladie du Huanglongbing (Greening) des agrumes à l'île Maurice. Détection de Candidatus Liberobacter Asiaticum et Candidatus Liberobacter Africanum dans les agrumes et les insectes vecteurs." Bordeaux 2, 1998. http://www.theses.fr/1998BOR28568.

Full text
APA, Harvard, Vancouver, ISO, and other styles
48

Kabir, Amin. "Phase coherent photorefractive effect in II-VI semiconductor quantum wells and its application for optical coherence imaging." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282315981.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Braun, Pierre-François. "Orientation de spin par pompage optique dans les boîtes quantiques InAs/GaAs : effets nucléaires." Toulouse, INSA, 2007. http://www.theses.fr/2007ISAT0054.

Full text
Abstract:
L’étude et le contrôle du spin d’un porteur dans une boîte quantique unique (BQ) est un élément clé en vue du développement de la spintronique et des composants de base nécessaires au stockage et à la manipulation de l’information quantique (e. G. Pour la création d’un ordinateur quantique). Dans cette thèse, on s’intéresse donc aux spins électroniques et nucléaires, couplés par interaction hyperfine, dans des BQs individuelles auto-organisées d’InAs/GaAs. Ce travail met plus particulièrement en avant la dynamique de spin des électrons, des noyaux et du système couplé. Une des motivations en est que, si l’on parvient à polariser fortement en spin les noyaux d’une boîte quantique, il devient dès lors imaginable de transférer un état cohérent électronique à un ensemble de noyaux pour en assurer le stockage. Pour ce faire, des expériences de pompage optique orienté par photoluminescence sont réalisées. Un microscope confocal original résolu en temps, en température, en champ magnétique et en polarisation, destiné à l’analyse par micro-photoluminescence de boîtes individuelles, est conçu et développé. Les mesures effectuées mettent d’une part en évidence le déphasage du spin électronique dû aux fluctuations du champ nucléaire. Cependant, nous montrons que s’il est possible de supprimer l’effet de déphasage pour la composante longitudinale du spin électronique, il n’en est rien concernant la composante transverse. D’autre part, les conditions d’obtention d’une forte polarisation nucléaire équivalente à un champ effectif de plusieurs Teslas ont été déterminées et des effets originaux de bistabilité de la polarisation nucléaire sur nano-objets uniques sont décrits et modélisés
The study and control of carrier spins in quantum dots is important for the development of future spintronic and elementary devices that process and store quantum information (e. G. In order to build a quantum computer). In this thesis electron and nuclear spins that are coupled by hyperfine interaction in single InAs/GaAs self-assembled quantum dots are investigated. This work focuses on the spin dynamics of the electron, the nuclei and the coupled system. When a strong nuclear polarisation is achieved in the dots, the transfer of a coherent electron spin state to the nuclei is anticipated, which represents a motivation for this study. To achieve these targets, photoluminescence experiments have been carried out. The design and construction of an original confocal time-, temperature-, magnetic field- and polarisation-resolved microscope, which allows us to record spectra of individual dots in micro-photoluminescence, is described. The experimental studies uncover the dephasing of the electronic spin due to nuclear field fluctuations. We show that the relaxation of the longitudinal spin component can be suppressed, but not the relaxation of the transverse component. Finally, the conditions required to achieve a strong nuclear polarisation equivalent to an effective field of several Teslas have been found and novel bistability effects of the nuclear polarisation in single nano-objects are recorded and quantitatively understood with a model
APA, Harvard, Vancouver, ISO, and other styles
50

Tranitz, Hans-Peter. "Vier- und Multiwellenmischen an II-VI-Halbleiternanostrukturen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2002. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200200017.

Full text
Abstract:
Diese Arbeit beschäftigt sich mit dem polarisations-, intensitäts- und temperaturabhängigen Dephasierungsverhalten kohärent angeregter Exzitonen, Biexzitonen und Trionen in Quantentrögen, Quantendrähten und Quanteninseln. Die Experimente, die an II-VI-Halbleiternano- strukturen durchgeführt wurden, basieren auf einer nichtlinear optischen Methode der Ultrakurzzeitspektroskopie, der Vierwellenmischung. Phasenrelaxation und Wechselwirkungsprozesse der resonant angeregten Quasiteilchen werden durch erweiterte optische Blochgleichungen theoretisch beschrieben. Um die Bedeutung von Korrelationen höherer Ordnung von Exzitonen in ZnSe Quantentrögen zu ermitteln, wird die Methode der Multiwellenmischung entwickelt. Durch Anwendung von modernen Halbleiterblochgleichungen bis zur 5. Ordnung in den anregenden Feldern gelingt die Beschreibung der beobachteten Spektren
In this theses the polarization, intensity and temperature dependent dephasing behavior of coherently excited excitons, biexcitons, and trions are investigated in quantum wells, quantum wires and quantum islands. The experiments, applied to II-VI semiconductor nanostructures, base on a nonlinear optical method of ultrashorttime spectroscopy, the four-wave mixing. Phase relaxation and interaction processes of the resonantly excited quasi-particles are described by extended optical bloch equations. The importance of higher order correlations of excitons in ZnSe quantum wells is investigated. Therefore a new method has been developed, the so called multi-wave mixing. The application of modern semiconductor bloch equations up to fifth order in the exciting fields results in a successful description of the observed spectra
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Trioxan' for other source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography