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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Synthese von N-Benzhydryl-anilinen und Untersuchungen zu Struktur-Eigenschafts-Zusammenhaengen hinsichtlich der Photoleitung in Polymermatrizen

Mais, Silvio 02 August 1996 (has links)
Bibliographische Beschreibung und Referat Mais, Silvio Synthese von N-Benzhydryl-anilinen und Untersuchungen zu Struktur- Eigenschafts-Zusammenhaengen hinsichtlich der Photoleitung in Polymermatrizen Technische Universitaet Chemnitz-Zwickau, Fakultaet fuer Naturwissenschaften, Dissertation, 1995, 134 Seiten Es erfolgen zum gegenwaertigen Kenntnisstand der Elektrophotographie kurze Abrisse bezueglich Wirkungsweise, Messprinzipien, Theorie der Photoleitfaehigkeit und Struktur-Eigenschafts-Zusammenhaengen. Synthesen von N-Benzhydryl-anilinen und substituierten N,N'-Dibenzhydryl-4,4'-diamino-biphenyle werden vorgestellt und diskutiert. Im Mittelpunkt steht die Substituentenvariation von Akzeptoren bis Donatoren. Vergleichende elektrophotographische Empfindlichkeitsmessungen dieser Verbindungen in polymeren Bindemittelschichten zeigen eine Abhaengigkeit der Photoleitung von der Substitution, welche sich mit den entsprechenden Hammett- Konstanten beschreiben laesst. NMR-Untersuchungen belegen die Abhaengigkeiten der chemischen Verschiebungen und Kopplungskonstanten bestimmter 1H-, 13C- und 15N-Kerne von der Substituentenvariation, welche sich ebenfalls mit grosser Korrelationsguete durch Hammett- oder Taft-Konstanten linear beschreiben lassen. Die elektrophotographische Empfindlichkeit der untersuchten Schichtsysteme laesst sich durch Farbstoffsensibilisierung und Erhoehung der Photoleiterkonzentration in praktisch interessierender Groessenordnungen steigern.
32

Techniques de catalyse et de flux continu pour faciliter la fermeture de molécules cycliques tendues

Lévesque, Éric 08 1900 (has links)
Cette thèse décrit l’exploration de techniques de catalyse et de flux continu pour faciliter la fermeture de molécules cycliques tendues. En premier lieu, un catalyseur de palladium permet de fermer un hétérocycle aromatique tendu, la structure benzo[a]imidazo[2,1,5-c,d]indolizine.16 La tension de cycle contribue à donner au système  hautement délocalisé de ces molécules des propriétés photophysiques intéressantes, différentes de celles de leurs analogues non tendus.21,33 Il a été démontré que leur longueur d’onde d’émission maximale peut être modulée de manière prévisible en modifiant les groupes fonctionnels conjugués au système aromatique. Le potentiel d’application en biochimie de ces fluorophores à déplacement de Stokes élevé a été exploré en étiquetant deux protéines en milieu biocompatible. En second lieu, une version catalytique de la cycloaddition de Simmons-Smith a été optimisée. Dans cette transformation, une quantité catalytique d’un sel de zinc permet de former un carbénoïde hautement réactif à partir d’un composé aryldiazométhane. Ce carbénoïde peut réagir avec une grande variété d’alcènes pour former les arylcyclopropanes correspondants. Un catalyseur modifié permet même à la réaction d’avoir lieu en présence d’alcools primaires. Enfin, la manipulation des composés aryldiazométhanes utilisés dans la cyclopropanation décrite ci-haut peut s’avérer risquée vu la toxicité et l’instabilité de ces composés. Pour minimiser ces risques, une méthode pour générer et purifier ces réactifs en flux continu a été développée. De cette manière, le composé dangereux est consommé à mesure qu’il est généré, dans un système fermé. Un large éventail d’aryldiazométhanes peut être produit en solution dans un solvant non-coordinant. La compatibilité de ces solutions avec des systèmes catalytiques requérant des réactifs propres et secs a été démontrée. / This thesis describes the exploration of catalysis and continuous flow techniques towards the formation of strained cyclic molecules. First, a palladium catalyst enables the ring closure of a strained aromatic heterocycle, the benzo[a]imidazo[2,1,5-c,d]indolizine.16 Ring strain gives these molecule’s highly delocalized  system interesting photophysical properties that differ from those of unstrained analogs.21,33 Their emissive properties can be predictably modulated by modifying functional groups conjugated to the aromatic core. These high Stokes-shift fluorophores’ application potential in biochemistry was explored by the biocatalyzed labelling of two proteins in biocompatible media. Second, a catalytic version of the Simmons-Smith cycloaddition was optimized. In this transformation, a catalytic amount of zinc salt allows the formation of a highly reactive carbenoid from an aryldiazomethane precursor. This intermediate can then react with a variety of alkenes, forming the corresponding arylcyclopropanes. A modified catalyst even enables the reaction to proceed in the presence of a primary alcohol group. Finally, the handling of the aryldiazomethane precursors used in the above reaction can be hazardous due to these compound’s instability and toxicity. To minimise these risks, a method to synthesise and purify these reagents in continuous flow was developed. This way, the dangerous chemical is consumed as it is generated, in a closed system. A large array of aryldiazomethane solutions in a non-coordinating solvent can be produced. These solutions’ compatibility with sensitive catalytic systems requiring clean and dry reagents was demonstrated.
33

Vliv úpravy povrchu borem dopovaných diamantových elektrod na elektrochemickou oxidaci fenolu a jeho derivátů / The influence of the surface pretreatment of boron doped diamond electrodes on electrochemical oxidation of phenol and its derivatives

Hnízdilová, Lucie January 2021 (has links)
The aim of this thesis is the study of electrochemical oxidation of para-substituted phenol derivates using cyclic voltammetry (CV) and ,,direct current" voltammetry (DCV) on boron-doped diamond electrode (BDD) and comparison with some analogous meta-substituted compounds. Among the studied substances were p-cresol, 4-methoxyphenol, 4-hydroxybenzoic acid, 3-(4-hydroxyphenyl)propionic acid, 4-nitrophenol, 4-chlorophenol and 3-(trifluoromethyl)phenol. The oxidation of the analytes was performed in an acidic (pH 2,0) and basic (pH 11,0) Britton-Robinson buffer on mechanically polished, oxidated and hydrogenated surfaces. Another subject of the thesis is to analyze the influence of different substituents, characterized by the Hammett constant, on the oxidation potential of selected phenols. They are oxidized at more positive redox potentials in acidic media, than in basic media, where they are dissociated. The oxidation on the polished and hydrogenated surfaces were similar, whereas were shifted to higher values on the oxidated surface. Further, the signal intensity decreased on the oxidated one, and the oxidation of phenols was not recognizable in basic media. The passivation of the electrode was less significant in pH 2,0 buffer. The best result of Hammett correlation was achieved on a polished and...
34

Oxidation and Reduction Process for Polycyclic Aromatic Hydrocarbons and Nitrated Polycyclic Aromatic Hydrocarbons

Tian, Zhenjiao January 2008 (has links)
No description available.
35

Thio-arylglyocosides with Various Aglycon Para-Substituents, a Useful Tool for Mechanistic Investigation of Chemical Glycosylations

Li, Xiaoning 12 September 2007 (has links)
No description available.
36

The hard-boiled detective: personal relationships and the pursuit of redemption

Howard, David George 19 July 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / By start of the 1920s, the United States had seen nearly forty years of vast accumulations of wealth by a small group of people, substantial financial speculation and a mass change in the economic base from agricultural to industrial. All of this ended in 1929 in a crushing depression that spread not only across the country, but also around the world. Hard-Boiled detective fiction first reached the reading public early in the decade initially as adventure stories, but quickly became a way for authors to express the stresses these changes were causing on people and society. The detective is the center of the story with the task of reestablishing a certain degree of order or redemption. An important character hallmark of this genre is that he is seldom able to do this, or that the cost is so high a terrible burden remains. His decisions and judgments in this attempt are formed by his relationship with the people or community around him. The goal of this thesis is to look at the issues raised in the context of how the detective relates to a person or community in the story. For analysis, six books were chosen arranged from least level of personal relationship by the detective to the most intimate. The books are Red Harvest, by Dashiell Hammett, The Big Sleep, by Raymond Chandler, The Galton Case, by Ross MacDonald, Cotton Comes to Harlem, by Chester Himes, Devil in a Blue Dress, by Walter Mosley, and I, the Jury, by Mickey Spillane. In the study of these books, a wide range of topics are presented including political ideologies, corruption, racial discrimination and family strife. Each book provided a wealth of views on these and other subjects that are as relevant today as when they were written.
37

The Thin Man och Film Noir : En Jämförande Studie i Genre / The Thin Man and Film Noir : A Comparative Study in Genre

Oxenhall, Johan January 2017 (has links)
Syftet med den här uppsatsen är att genomföra en jämförande studie av den klassiska Hollywood-deckaren, representerad av de tre första filmerna i Thin Man-serien, och film noir. Analysen utgår ifrån Thin Man-filmerna The Thin Man (1934), After the Thin Man (1936) och Another Thin Man (1939) och noir filmerna The Maltese Falcon (1941), Laura (1944), The Big Sleep (1946) och Dark Passage (1947). Den grundläggande teorin för uppsatsen är genreteori och hur den klassiska Hollywood-deckarfilmen skilde sig ifrån film noir. Analysen är uppdelad i fyra kapitel, i vilka olika delar av innehållet i både Thin Man-filmerna och de fyra exemplen av film noir analyseras. De olika kapitlen handlar om manliga huvudkaraktären, den kvinnliga huvudkaraktären, hur de olika filmerna hanterade ämnen berörande sex och sexualitet och hur samhället och människorna representeras i filmerna. Slutsats omfattar sedan en diskussion om uppsatsens resultat och svaret på varför Thin Man-filmerna inte räknas som film noir.
38

Synthese von N-Benzhydryl-anilinen und Untersuchungen zu Struktur-Eigenschafts-Zusammenhaengen hinsichtlich der Photoleitung in Polymermatrizen

Mais, Silvio 01 August 1995 (has links)
Bibliographische Beschreibung und Referat Mais, Silvio Synthese von N-Benzhydryl-anilinen und Untersuchungen zu Struktur- Eigenschafts-Zusammenhaengen hinsichtlich der Photoleitung in Polymermatrizen Technische Universitaet Chemnitz-Zwickau, Fakultaet fuer Naturwissenschaften, Dissertation, 1995, 134 Seiten Es erfolgen zum gegenwaertigen Kenntnisstand der Elektrophotographie kurze Abrisse bezueglich Wirkungsweise, Messprinzipien, Theorie der Photoleitfaehigkeit und Struktur-Eigenschafts-Zusammenhaengen. Synthesen von N-Benzhydryl-anilinen und substituierten N,N'-Dibenzhydryl-4,4'-diamino-biphenyle werden vorgestellt und diskutiert. Im Mittelpunkt steht die Substituentenvariation von Akzeptoren bis Donatoren. Vergleichende elektrophotographische Empfindlichkeitsmessungen dieser Verbindungen in polymeren Bindemittelschichten zeigen eine Abhaengigkeit der Photoleitung von der Substitution, welche sich mit den entsprechenden Hammett- Konstanten beschreiben laesst. NMR-Untersuchungen belegen die Abhaengigkeiten der chemischen Verschiebungen und Kopplungskonstanten bestimmter 1H-, 13C- und 15N-Kerne von der Substituentenvariation, welche sich ebenfalls mit grosser Korrelationsguete durch Hammett- oder Taft-Konstanten linear beschreiben lassen. Die elektrophotographische Empfindlichkeit der untersuchten Schichtsysteme laesst sich durch Farbstoffsensibilisierung und Erhoehung der Photoleiterkonzentration in praktisch interessierender Groessenordnungen steigern.
39

Vers des assemblages de complexes métalliques oligonucléaires, servant d’antenne solaire au niveau moléculaire

Chartrand, Daniel 12 1900 (has links)
Les fichiers additionnels sont les données cristallographiques en format CIF. Voir le site de la Cambridge Crystallographic Data Centre pour un visualiseur: http://www.ccdc.cam.ac.uk / Ce projet de recherche vise l’élaboration de systèmes métallosupramoléculaires artificiels imitant le processus naturel de la photosynthèse. Idéalement, ces systèmes seraient capables de fournir l’énergie et la séparation de charge nécessaire pour catalyser des réactions à transfert multiélectroniques, tel que l’hydrolyse de l’eau ou la réduction du gaz carbonique. La réalisation d’un tel système catalytique créerait une source d’énergie renouvelable, sous forme d’énergie chimique, crée directement à partir de l’énergie solaire. Le système envisagé, schématisé sous la forme d’une antenne, possède trois parties distinctes. Tout d’abord, des chromophores forment un état excité en captant l’énergie de la lumière visible du soleil. Vient ensuite un centre de liaison qui lie tous les chromophores et qui collecte l’énergie de cet état excité à travers un transfert d’électron. Cet électron est de nouveau transféré vers la dernière partie, un centre réactionnel catalytique. Cet assemblage permet de créer une séparation de charge entre le chromophore et le centre réactionnel qui sont séparés par le centre de liaison, évitant ainsi la recombinaison de charge. Le projet se focalise sur la synthèse, la caractérisation et l’application en photocatalyse d’assemblages chromophore–centre de liaison–catalyseur. Tout d’abord, une étude de chromophores à base de fluorène et de rhénium a été effectuée dans le but d’évaluer le transfert électronique entre ces deux composants. Ensuite, des centres de liaisons à base de dimère de rhodium tétraamidinate ont été créés et étudiés afin d’établir leurs caractéristiques photophysiques et électrochimiques. Puis un d’entre eux a été assemblé avec des chromophores de rhénium, créant ainsi des espèces moléculaires discrètes contenant d’un à quatre chromophores. Et pour finir, ces assemblages ont été combinés avec un catalyseur à base de cobalt, puis ont été testés dans des expériences de photoproduction d’hydrogène. Cette dernière partie a requis l’élaboration d’un photoréacteur qui est aussi décrite en détail dans cet ouvrage. / This research project involves synthetic metallosupramolecular systems developed to mimic the natural process of photosynthesis. Ideally, these systems would be able to provide the energy and the charge separation needed to catalyze multielectron-transfer reactions, such as water-splitting or carbon dioxide reduction. The realization of such a catalytic system would create a renewable energy source, in the form of chemical energy, created directly from solar energy. The system envisioned has three distinct parts in the form of an antenna. First of all, chromophores go into an excited state, while capturing the visible light energy of the Sun. Then comes a hub which binds all the chromophores and collects this excited state energy through an electron transfer. This electron is then transferred again to the last part, a catalytic reaction center. This assembly creates a charge separation between the chromophore and the reaction center which are separated by the hub, thus avoiding the recombination of charge. The project focuses on the synthesis, characterization and application in photocatalysis of chromophore-hub-catalyst assemblies. First of all, a study of fluorene and rhenium based chromophores was made to assess the electronic transfer between these two components. Then, tetraamidinate rhodium dimer based hubs have been created and studied in order to establish their photophysical and electrochemical characteristics. Then one of these assemblies was formed with chromophores of rhenium, thus creating discrete molecular species containing one to four chromophores. And finally, these assemblies were combined with a cobalt-based catalyst and were tested for hydrogen photoproduction. The latter required the development of a photoreactor which is also described in detail in this thesis.
40

Lesbian detective fiction : the outsider within

Simpson, Inga Caroline January 2008 (has links)
Lesbian Detective Fiction: the outsider within is a creative writing thesis in two parts: a draft lesbian detective novel, titled Fatal Development (75%) and an exegesis containing a critical appraisal of the sub-genre of lesbian detective fiction, and of my own writing process (25%). Creative work: Fatal Development -- It wasn’t the first time I’d seen a dead body, but it didn’t seem to get any easier. -- When Dirk and Stacey discover a body in the courtyard of their Brisbane woolstore apartment, it is close friend and neighbour, Kersten Heller, they turn to for support. The police assume Stuart’s death was an accident, but when it emerges that he was about to take legal action against the woolstore’s developers, Bovine, Kersten decides there must be more to it. Her own apartment has flooded twice in a month and the builders are still in and out repairing defects. She discovers Stuart was not alone on the roof when he fell to his death and the evidence he had collected for his case against Bovine has gone missing. Armed with this knowledge, and fed up with the developer’s ongoing resistance to addressing the building’s structural issues, Kersten organises a class action against Bovine. Kersten draws on her past training as a spy to investigate Stuart’s death, hiding her activities, and details of her past, from her partner, Toni. Her actions bring her under increasing threat as her apartment is defaced, searched and bugged, and she is involved in a car chase across New Farm. Forced to fall back on old skills, old habits and memories return to the surface. When Toni discovers that Kersten has broken her promise to leave the investigation to the police, she walks out. The neighbouring – and heritage-listed – Riverside Coal development site burns to the ground, and Kersten and Dirk uncover evidence of a network of corruption involving developers and local government officials. After she is kidnapped in broad daylight, narrowly escaping from the boot of a moving car, Kersten is confident she is right, but with Toni not returning her calls, and many of the other residents selling up, including Dirk and Stacey, Kersten begins to question her judgment. In a desperate attempt to turn things around, Kersten calls on an old Agency contact to help prove Bovine was involved in Stuart’s death, her kidnapping, and ongoing corruption. To get the evidence she needs, Kersten plays a dangerous game: letting Bovine know she has uncovered their illegal operations in order to draw them into revealing themselves on tape. Hiding alone in a hotel room, Kersten is finally forced to confront her past: When Mirin didn’t come home that night, I was ready to go out and find her myself, disappear, and start a new life together somewhere far away. Instead they pulled me in before I could finish making arrangements, questioned me for hours, turned everything around. It was golden child to problem child in the space of a day. This time, she’s determined, things will turn out differently. Exegesis: The exegesis traces the development of lesbian detective fiction, including its dual origins in detective and lesbian fiction, to compare the current state of the sub-genre with the early texts and to establish the dominant themes and tropes. I focus particularly on Australian examples of the sub-genre, examining in detail Claire McNab’s Denise Cleever series and Jan McKemmish’s A Gap in the Records, in order to position my own lesbian detective novel between these two works. In drafting Fatal Development, I have attempted to include some of the political content and complexity of McKemmish’s work, but with a plot-driven narrative. I examine the dominant tropes and conventions of the sub-genre, such as: lesbian politics; the nature of the crime; method of investigation; sex and romance; and setting. In the final section, I explain the ways in which I have worked within and against the subgenre’s conventions in drafting a contemporary lesbian detective novel: drawing on tradition and subverting reader expectations. Throughout the thesis, I explore in detail the tradition of the fictional lesbian detective as an outsider on the margins of society, disrupting notions of power and gender. While the lesbian detective’s outsider status grants her moral agency and the capacity to achieve justice and generate change, she is never fully accepted. The lesbian detective remains an outsider within. For the lesbian detective, working within a system that ultimately discriminates against her involves conflict and compromise, and a sense of double-play in being part of two worlds but belonging to neither. I explore how this double-consciousness can be applied to the lesbian writer in choosing whether to write for a mainstream or lesbian audience.

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