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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.
21

Formation d'émulsions multiples stimulables en une seule étape d'émulsification : effet du sel et évolution vers des architectures biocompatibles / Formation of stimuli-responsive multiple emulsions in a one-step emulsification process : effect of ionic strength and evolution towards biocompatibility

Protat, Marine 21 October 2016 (has links)
Nous nous sommes intéressés aux émulsions multiples stimulables formées en une étape d’émulsification mécanique. Ces émulsions sont stabilisées par des copolymères amphiphiles synthétisés par polymérisation radicalaire contrôlée par transfert d’atome. L’ajustement du pH et de la force ionique permet la préparation de différents types d’émulsion, dont des émulsions multiples à phase eau (E/H/E) ou huile (H/E/H) continue qui sont stables sur plusieurs mois. Nous avons étudié deux systèmes entièrement biocompatibles permettant la formation d’émulsions E/H/E stabilisées par un unique copolymère, de type poly(diméthylsiloxane)-b-poly(méthacrylate de diméthylamino éthyle). Les émulsions eau/ Miglyol® 812/eau ainsi formulées permettent l’encapsulation et la libération contrôlée de composés hydrophiles par les trois stimuli : pH, force ionique et température. Par ailleurs, nous nous sommes intéressés aux conditions de formation d’émulsions multiples à partir d’un système modèle eau – toluène – polystyrène-b-poly(styrène-st-méthacrylate de diméthylamino éthyle). Nous avons sondé la conformation du copolymère à l’interface eau – huile par réflectivité de neutrons. Les résultats obtenus montrent une corrélation entre cette conformation et le type d’émulsion. De plus, l’obtention d’émulsions multiples est favorisée par la réduction de la courbure des microémulsions formées dans l’eau, telles qu’étudiées par cryo-microscopie électronique à transmission et diffusion de neutrons aux petits angles. Enfin, des critères prédictifs de la formation d’émulsions multiples ont été obtenus grâce à des mesures de tension interfaciale et du partitionnement du copolymère entre les deux phases. / We studied stimuli-responsive multiple emulsions formed in a one-step mechanical emulsification process. These emulsions are stabilized by amphiphilic copolymers synthesized by atom transfer radical polymerization. Depending on pH, ionic strength and temperature, different emulsion types can be obtained, including water-continuous (W/O/W) and oil-continuous (O/W/O) multiple emulsions. These emulsions are stable during several months. We formed W/O/W emulsions with two entirely biocompatible systems using a poly(dimethylsiloxane)-b-poly(dimethylaminoethyl methacrylate) copolymer. Water/Miglyol® 812/water emulsions formulated with this copolymer enable the encapsulation and controlled release of hydrophilic species with the three stimuli: pH, ionic strength and temperature. Furthermore, we studied the formation conditions of multiple water – toluene – polystyrene-b-poly(styrene-st-dimethylaminoethyl methacrylate) emulsions. We probed the conformation of the polymer adsorbed at the water – oil interface using neutron reflectivity. Our results show an existing correlation between emulsion type and polymer conformation. Moreover, the formation of multiple emulsions is promoted by a decrease in the curvature of the microemulsions formed in water, which was assessed by cryo transmission electron microscopy and small angle neutron scattering. Finally, we settled predictive criteria for the formation of multiple emulsions. These criteria are based on interfacial tension and polymer partitioning measurements.
22

Analysis and feedback control of the scanning laser epitaxy process applied to nickel-base superalloys

Bansal, Rohan 08 April 2013 (has links)
Scanning Laser Epitaxy (SLE) is a new layer-by-layer additive manufacturing process being developed in the Direct Digital Manufacturing Laboratory at Georgia Tech. SLE allows for the fabrication of three-dimensional objects with specified microstructure through the controlled melting and re-solidification of a metal powder placed atop a base substrate. This dissertation discusses the work done to date on assessing the feasibility of using SLE to both repair single crystal (SX) turbine airfoils and manufacture functionally graded turbine components. Current processes such as selective laser melting (SLM) are not able to create structures with defined microstructure and often have issues with warping of underlying layers due to the high temperature gradients present when scanning a high power laser beam. Additionally, other methods of repair and buildup have typically been plagued by crack formation, equiaxed grains, stray grains, and grain multiplication that can occur when dendrite arms are separated from their main dendrites due to remelting. In this work, it is shown that the SLE process is capable of creating fully dense, crack-free equiaxed, directionally-solidified, and SX structures. The SLE process, though, is found to be currently constrained by the cumbersome method of choosing proper parameters and a relative lack of repeatability. Therefore, it is hypothesized that a real-time feedback control scheme based upon a robust offline model will be necessary both to create specified defect-free microstructures and to improve the repeatability of the process enough to allow for multi-layer growth. The proposed control schemes are based upon temperature data feedback provided at high frame rate by a thermal imaging camera. This data is used in both PID and model reference adaptive control (MRAC) schemes and drives the melt pool temperature during processing towards a reference melt pool temperature that has been found to give a desired microstructure in the robust offline model of the process. The real-time control schemes will enable the ground breaking capabilities of the SLE process to create engine-ready net shape turbine components from raw powder material.
23

Etablierung eines Verfahrens zum Nachweis epigenetischer Biomarker im peripheren Blut zur Stratifizierung der Therapie des Rektumkarzinoms / Fully-automated hypermethylation testing by One-Step-Real-Time-PCR of 6 different potential epigenetic biomarkers in peripheral blood for rectal cancer detection and follow-up.

Thormann, Tobias 17 December 2015 (has links)
No description available.
24

Apport de la chimie ‘‘click’’ pour le marquage au carbone-11 et au fluor-18 de nucléosides et d’oligonucléotides / "Click" chemistry contribution for labeling nucleosides and oligonucleotides with carbon-11 and fluorine-18 as potential radiotracers for Positron Emission Tomography (PET) imaging

Bordenave, Thomas 14 December 2012 (has links)
La Tomographie par émission de positons (TEP) constitue l’une des techniques d’imagerie médicale les plus novatrices pour la visualisation in vivo des processus biologiques. Elle intervient comme technique de choix pour le diagnostic dans de nombreux domaines notamment, en oncologie, cardiologie ou encore en neurologie. La conception et l’élaboration de nouveaux radiotraceurs sont en perpétuel développement. L’utilisationd’oligonucléotides (ODN) modifiés (aptamères) possédant une grande affinité et spécificité pour une cible (gène,protéine, principe actif), comme radiotraceur pour l’imagerie in vivo apparait comme une alternative intéressante. A ce jour, quelques rares exemples d’oligonucléotides marqués, par un radioisotope, ont été décrits dans la littérature.Dans ce contexte, il a été développé deux méthodologies d’introduction du radioisotope (11C ou 18F) en dernièreétape de synthèse par chimie ‘‘click’’ pour le marquage de nucléosides et d’oligonucléotides envisagés commeradiotraceurs pour la TEP. / Positron Emission Tomography (PET) is a powerful molecular-imaging technique for physiological and biologicalinvestigations in various areas, such as oncology, cardiology, and neurosciences, as well as for drug development.Due to the increasing need of this technique for in vivo applications, there is always a demand for the developmentof new tracers and radiolabeling strategies. Furthermore, because of their excellent targeting capacities and easysynthesis along with a high level of diversity, oligonucleotides are already extensively used in vitro as ligands fornucleic acids (antisense oligonucleotides), proteins, and small related molecules (aptamer oligonucleotides). Theuse of aptamers for in vivo imaging appears especially promising, because of the wide range of possibilitiesavailable to introduce variations in their structure through defined chemical modifications. However, only fewexamples of oligonucleotide labeling for PET have been reported. In this context, we have developed twomethodological ways to introduce the radioisotope (11C, 18F), by ‘‘click’’ chemistry, at the last radiosynthesis stepin order to label nucleoside and oligonucleotide as potential radiotracers for PET.
25

Desenvolvimento e avaliação do processo de obtenção de emulsões múltiplas A/O/A em etapa única empregando óleo de canola e tensoativo não iônico derivado do óleo de rícino / Development and evaluation of the production process of multiple emulsions W/O/W by one step employing canola oil and derivative castor oil non ionic surfactant

Morais, Jacqueline Moreira de 04 June 2008 (has links)
As emulsões múltiplas mostram-se como veículos promissores em várias áreas das ciências cosmética e farmacêutica. O estudo do método de obtenção de emulsões múltiplas em etapa única é ferramenta útil para elucidação de seus aspectos físico-químicos e para viabilizar sua aplicação tecnológica. O objetivo da pesquisa foi desenvolver e caracterizar os aspectos físico-químicos do processo de emulsificação em etapa única, das emulsões múltiplas A/O/A obtidas e dos tensoativos empregados. Testes preliminares de estabilidade e avaliação do seu perfil de liberação (cafeína) foram realizados. Nanoemulsões foram inicialmente obtidas pela metodologia proposta, resultado de processo de emulsificação por inversão de fases. Suas características físico-químicas foram determinadas (valores de pH, potencial zeta e granulometria) e a influência de aditivos avaliada. Para o desenvolvimento da emulsão múltipla foram realizadas análises qualitativas e quantitativas das variáveis relevantes à composição (tipo de fase oleosa, de tensoativo hidrofílico, valor de EHL, emprego de diagrama ternário) e ao método de emulsificação (temperatura de aquecimento das fases e de emulsificação, ordem de adição e velocidade de agitação). Os estudos das propriedades físico-químicas dos tensoativos e do filme interfacial formado (cloud point, tensão superficial, CMC, reologia interfacial, reologia de fluxo e isotermas de Langmuir) foram primordiais para compreensão dos fenômenos envolvidos e relevantes ao processo de emulsificação proposto. As emulsões múltiplas foram caracterizadas quanto aos aspectos macro e microscópico, granulometria, valores de pH, potencial zeta, viscosidade relativa, perfil reológico e influência da adição de macromoléculas. A temperatura de manipulação e de emulsificação (78±2grausC) foram parâmetros fundamentais para obtenção destes sistemas em etapa única. Seus aspectos macro e microscópico foram extremamente dependentes da temperatura de emulsificação. Os resultados indicam glóbulos múltiplos consideravelmente menores do que os relatados pela literatura. Foi possível observar, no intervalo de temperatura considerado crítico para o processo, valores de tensão superficial/interfacial mínimos. Os resultados de elasticidade superficial sugerem que o comportamento das moléculas de tensoativos, em associação ou não, foi marcadamente influenciado pela temperatura e que o aumento do número de moléculas do tensoativo hidrofólico na superfície foi desfavorável as interações intramoleculares. A isoterma para os tensoativos em associação e em função da temperatura exibiu marcante inflexão para a faixa de temperatura crítica. Este comportamento indica uma dramática alteração na microestrutura do filme interfacial. O processo de encapsulação foi considerado eficiente. Os resultados obtidos indicam que, no atual estágio de desenvolvimento, não foi possível definir um perfil de liberação para a emulsão múltipla em análise. O método de emulsificação escolhido permitiu a obtenção de sistema múltiplo em etapa única, determinado pelas características físico-químicas dos tensoativos empregados, em especial do tensoativo hidrofílico derivado do óleo de rícino e do processo proposto. A formação de emulsões múltiplas anormais não ocasionais ou momentâneas sugere uma combinação dos processos de inversão de fases transicional, influência do emprego de tensoativos não-iônicos etoxilados, e catastrófica, influência da razão entre o volume da fase dispersa e dispersante. As emulsões múltiplas obtidas apresentaram difícil reprodutibilidade microestrutural; entretanto podem ser consideradas estáveis frente às metodologias de avaliação e análise empregadas. / Multiple emulsions are potential vehicles not only for the cosmetic science, but also for the pharmaceutical science. Study the manufacture process of multiple emulsions by one step is a useful tool for understanding their physical-chemistry aspects and making their technological application practicable as well. The goals of this research were to development and characterize the physical chemistry features of the emulsification process by one step, the W/O/W multiple emulsions produced and the surfactants employed. Preliminary stability tests and evaluation of the release profile (caffeine) were carried out. Initially, nano-emulsions were produced by the proposed methodology, resulting from phase inversion emulsification process. Their physical chemistry aspects (pH and zeta potential values and size distribution) and electrolytes addition influence were evaluated. In order to develop the multiple emulsions, noteworthy qualitative and quantitative variables related to the composition (oil phase and hydrophilic surfactant types, HLB values, phase diagram) and to emulsification process (heating and emulsification temperatures, addition order and agitation speed) were analyzed. Analyses of the physical chemistry aspects of the surfactants in solution and their interfacial film (cloud point, surface tension, CMC, interfacial and flux rheology, and Langmuir isotherms) were essential in order to understand the phenomena related to proposed emulsification process. Multiple emulsion analyses (macroscopic, microscopic, size distribution, pH and zeta potential values, relative viscosity, rheological profile and macromolecule addition influence) were carried out. Production and emulsification temperatures (78±2grausC) were fundamental parameters in order to obtain multiple droplets by one step. Their macro and microscopic aspects were completely conditioned by the emulsification temperature. The sizes of the multiple droplets obtained were significantly smaller than those reported in the literature. For the critical temperature range, the minimum surface tension values were reached. Surface elasticity results suggest that the behavior of the surfactant molecules, in association or not, was fundamentally influenced by the temperature. Increasing surfactant molecule moieties on the surface, the intra molecular interactions were misplaced. The Langmuir isotherm as a function of the temperature demonstrated distinctive behavior for the critical temperature range, where the transition phase into solid state and soon afterwards some collapse could be observed. This phenomenon indicated some dramatic alteration of the surface film microstructure. The encapsulation process was regarded as efficient. The release profile studies demonstrated that the dispersed system in analysis was not ready yet for this research stage. The proposed emulsification process was able to produce multiple droplets by one step; moreover this result presented direct influence of the surfactant physical chemistry features, particularly the hydrophilic one, castor oil derivate, and of the methodology employed. The abnormal, non-occasional and non-transitory, multiple emulsion formation suggest a combination of transitional (ethoxylated non ionic surfactant influence), and catastrophic (dispersed/dispersant ratio influence) phase inversion processes. The obtained multiple emulsions presents microstructure aspects were not easily reproducible; however those were regarded stable for the analysis methodology employed.
26

雙人決策秘書問題的研究 / A Variation of Two Decision Makers in a Secretary Problem

周冠群, Chou, Guan-Chun Unknown Date (has links)
Chen, Rosenberg和Shepp(1997)的“雙人決策者的秘書問題“(A Secretary Problem with Two Decision Makers),探討在完整訊息(Full Information)與選擇次序不變的情況下,具有優先選擇權的決策者佔有較大優勢。這裡所謂的優勢意指在雙方最終選擇的大小為勝負條件所產生獲勝機率的比較。而本篇文章主要是延伸此一探討,意即在若不變動兩者選擇的次序,但賦予後選擇決策者較多資訊的條件下,能否平衡雙方的優劣勢。我們首先討論後決策者擁有預知下一步(One-step look-ahead)資訊能力的條件下,雙方優勢的改變;隨之若是在後決策者能預知完全資訊的情況下,是否能平衡雙方的優劣勢。而事實上,即便在後決策者擁有所有資訊的條件,仍無法完全改變此一情況;更進一步而言,先選擇決策者甚至在不知道後決策者已掌握了所有資訊的情況下,仍可佔有獲勝機率大於後決策者的優勢。這裡我們將提供理論與理論上的數值結果。 / Chen, Rosenberg, and Shepp (1997) considered a variation of the "secretary problem" in which the salary demands of a group of applicants are from a known and continuous distribution (i.e., full information case) and these applicants are interviewed sequentially by two managers, say, I and II. For every applicant. Manager I has the right to interview and hire him/her first. If Manager I rejects the applicant, Manager II can interview him/her. No recall is allowed when the applicant is rejected by both managers, and neither manager can interview and hire another applicant once he/she has hired an applicant. The manager who chooses the applicants with the lower salary wins the game. Chen et al. shows that manager I has bigger winning chance than manager II in the full information case. This study is to extend the paper by Chen et al., by giving extra information to manager H. In particular, suppose that manager II can look a few applicants ahead, i.e., he/she knows the salary demands of applicants before manager I interview them. However, under the full-information assumption, even if manager II is a clairvoyant, who claims to be able to see what will happen in the future, his/her winning probability is still less than that of manager I. We provide theoretical proof and simulation to confirm this result.
27

A research on framing the Free Trade Areas across The Taiwan Strait¡Gfrom the Regional Economic Integration viewpoint

Ke, Chun-Kung 19 June 2003 (has links)
Abstract The title of this thesis is ¡§ A research on framing the Free Trade Areas across the Taiwan Strait: from the Regional Economic Integration viewpoint¡¨. The main themes of this thesis can be categorized into two parts: 1.Elaborating the theory of Free Trade Areas and the legal framework of global economic law to find out the reason why GATT/WTO permits to build Free Trade Areas as an exception of the GATT/WTO Most-Favored Treatment rule; and further stating the meaning and inspiration of Free Trade Areas across the Taiwan Strait under the experiences of EU and NAFTA. 2.After entering the WTO, according to the international norm, it¡¦s a must for both sides of The Taiwan Strait to adjust their economic relationship and set up a cross-strait free trade zone from the experience of EU and NAFTA in accordance with the natural regularity of international economic development relationship. Taiwan and Mainland China, on two sides of the Twian Strait have become members of the WTO, and have officially connected with international trade and economic organism. It is essential for two sides to develop their economic interrelationship on the basis of the natural regularity of international economic development relationship. This thesis emphasizes that the development of economic relationship across the Taiwan Strait is a step-by-step process and suggests that the process can be divided into three steps as follows: 1.Normalization of economic relationship across the Taiwan Strait after entering WTO¡Ðit means that the activities of trade and investment across The Taiwan Strait should be transformed from ¡§indirect¡¨ into ¡§direct.¡¨ In addition, the restrictions on the movement of the people between Taiwan and Mainland China should be eased. These changes certainly lead to more problems for Taiwan side and it is urgent to negotiate and sign agreements with China for the Agreement of Trade and Investment in order to secure its benefit in the cross-strait economic development. 2.¡§One-step-forward framework¡¨¡ÐI would like to suggest that the second step of the cross-strait economic development should go one step forward to set up a framework under which the Free Trade Agreement, industries cooperation and Custom Unions to be fulfilled. 3.The setup of the Free Trade Areas¡ÐThe Free Trade Areas can be materialized though discussion between two sides based on ¡§one-step-forward framework¡¨ In this thesis, I found out that the best policy for Taiwan and Mainland China is to construct the Free Trade Areas across the Taiwan Strait under the legal framework of WTO. However, there are some prerequisites needed to be considered as follows: 1.Raising the international competition; 2.Averting to be marginalized under the trend of Regional Economic Integration; 3.Evaluating the complementary structure of industries between Taiwan and Mainland China with an analysis of the background, humanities and history between Taiwan and Mainland China. When the Free Trade Areas to be established in the future, it is recommend that the establishment of a Common Market across the Taiwan Strait will most benefit Taiwan and Mainland in the long run.
28

Desenvolvimento e avaliação do processo de obtenção de emulsões múltiplas A/O/A em etapa única empregando óleo de canola e tensoativo não iônico derivado do óleo de rícino / Development and evaluation of the production process of multiple emulsions W/O/W by one step employing canola oil and derivative castor oil non ionic surfactant

Jacqueline Moreira de Morais 04 June 2008 (has links)
As emulsões múltiplas mostram-se como veículos promissores em várias áreas das ciências cosmética e farmacêutica. O estudo do método de obtenção de emulsões múltiplas em etapa única é ferramenta útil para elucidação de seus aspectos físico-químicos e para viabilizar sua aplicação tecnológica. O objetivo da pesquisa foi desenvolver e caracterizar os aspectos físico-químicos do processo de emulsificação em etapa única, das emulsões múltiplas A/O/A obtidas e dos tensoativos empregados. Testes preliminares de estabilidade e avaliação do seu perfil de liberação (cafeína) foram realizados. Nanoemulsões foram inicialmente obtidas pela metodologia proposta, resultado de processo de emulsificação por inversão de fases. Suas características físico-químicas foram determinadas (valores de pH, potencial zeta e granulometria) e a influência de aditivos avaliada. Para o desenvolvimento da emulsão múltipla foram realizadas análises qualitativas e quantitativas das variáveis relevantes à composição (tipo de fase oleosa, de tensoativo hidrofílico, valor de EHL, emprego de diagrama ternário) e ao método de emulsificação (temperatura de aquecimento das fases e de emulsificação, ordem de adição e velocidade de agitação). Os estudos das propriedades físico-químicas dos tensoativos e do filme interfacial formado (cloud point, tensão superficial, CMC, reologia interfacial, reologia de fluxo e isotermas de Langmuir) foram primordiais para compreensão dos fenômenos envolvidos e relevantes ao processo de emulsificação proposto. As emulsões múltiplas foram caracterizadas quanto aos aspectos macro e microscópico, granulometria, valores de pH, potencial zeta, viscosidade relativa, perfil reológico e influência da adição de macromoléculas. A temperatura de manipulação e de emulsificação (78±2grausC) foram parâmetros fundamentais para obtenção destes sistemas em etapa única. Seus aspectos macro e microscópico foram extremamente dependentes da temperatura de emulsificação. Os resultados indicam glóbulos múltiplos consideravelmente menores do que os relatados pela literatura. Foi possível observar, no intervalo de temperatura considerado crítico para o processo, valores de tensão superficial/interfacial mínimos. Os resultados de elasticidade superficial sugerem que o comportamento das moléculas de tensoativos, em associação ou não, foi marcadamente influenciado pela temperatura e que o aumento do número de moléculas do tensoativo hidrofólico na superfície foi desfavorável as interações intramoleculares. A isoterma para os tensoativos em associação e em função da temperatura exibiu marcante inflexão para a faixa de temperatura crítica. Este comportamento indica uma dramática alteração na microestrutura do filme interfacial. O processo de encapsulação foi considerado eficiente. Os resultados obtidos indicam que, no atual estágio de desenvolvimento, não foi possível definir um perfil de liberação para a emulsão múltipla em análise. O método de emulsificação escolhido permitiu a obtenção de sistema múltiplo em etapa única, determinado pelas características físico-químicas dos tensoativos empregados, em especial do tensoativo hidrofílico derivado do óleo de rícino e do processo proposto. A formação de emulsões múltiplas anormais não ocasionais ou momentâneas sugere uma combinação dos processos de inversão de fases transicional, influência do emprego de tensoativos não-iônicos etoxilados, e catastrófica, influência da razão entre o volume da fase dispersa e dispersante. As emulsões múltiplas obtidas apresentaram difícil reprodutibilidade microestrutural; entretanto podem ser consideradas estáveis frente às metodologias de avaliação e análise empregadas. / Multiple emulsions are potential vehicles not only for the cosmetic science, but also for the pharmaceutical science. Study the manufacture process of multiple emulsions by one step is a useful tool for understanding their physical-chemistry aspects and making their technological application practicable as well. The goals of this research were to development and characterize the physical chemistry features of the emulsification process by one step, the W/O/W multiple emulsions produced and the surfactants employed. Preliminary stability tests and evaluation of the release profile (caffeine) were carried out. Initially, nano-emulsions were produced by the proposed methodology, resulting from phase inversion emulsification process. Their physical chemistry aspects (pH and zeta potential values and size distribution) and electrolytes addition influence were evaluated. In order to develop the multiple emulsions, noteworthy qualitative and quantitative variables related to the composition (oil phase and hydrophilic surfactant types, HLB values, phase diagram) and to emulsification process (heating and emulsification temperatures, addition order and agitation speed) were analyzed. Analyses of the physical chemistry aspects of the surfactants in solution and their interfacial film (cloud point, surface tension, CMC, interfacial and flux rheology, and Langmuir isotherms) were essential in order to understand the phenomena related to proposed emulsification process. Multiple emulsion analyses (macroscopic, microscopic, size distribution, pH and zeta potential values, relative viscosity, rheological profile and macromolecule addition influence) were carried out. Production and emulsification temperatures (78±2grausC) were fundamental parameters in order to obtain multiple droplets by one step. Their macro and microscopic aspects were completely conditioned by the emulsification temperature. The sizes of the multiple droplets obtained were significantly smaller than those reported in the literature. For the critical temperature range, the minimum surface tension values were reached. Surface elasticity results suggest that the behavior of the surfactant molecules, in association or not, was fundamentally influenced by the temperature. Increasing surfactant molecule moieties on the surface, the intra molecular interactions were misplaced. The Langmuir isotherm as a function of the temperature demonstrated distinctive behavior for the critical temperature range, where the transition phase into solid state and soon afterwards some collapse could be observed. This phenomenon indicated some dramatic alteration of the surface film microstructure. The encapsulation process was regarded as efficient. The release profile studies demonstrated that the dispersed system in analysis was not ready yet for this research stage. The proposed emulsification process was able to produce multiple droplets by one step; moreover this result presented direct influence of the surfactant physical chemistry features, particularly the hydrophilic one, castor oil derivate, and of the methodology employed. The abnormal, non-occasional and non-transitory, multiple emulsion formation suggest a combination of transitional (ethoxylated non ionic surfactant influence), and catastrophic (dispersed/dispersant ratio influence) phase inversion processes. The obtained multiple emulsions presents microstructure aspects were not easily reproducible; however those were regarded stable for the analysis methodology employed.
29

Développement de nouvelles molécules plateformes pour le marquage par du monoxyde de carbone : applications en imagerie par Tomographie d'Emission de Positions (TEP) et imagerie bimodale TEP/optique / Development of tags for a general lost-step isotope labeling of biomolecule-based substrates with carbon monoxide : pallado-catalized carbonylation and PET application

Cornilleau, Thomas 07 December 2016 (has links)
La Tomographie par Emission de Positrons (TEP) constitue l’une des techniques d’imagerie moléculaire les plus novatrices pour la visualisation in vivo des processus biologiques. Elle intervient comme technique de choix pour le diagnostic dans de nombreux domaines. La conception et l’élaboration de nouveaux radiotraceurs sont en perpétuel développement. Dans ce contexte une méthode d’introduction du radioisotope 11C a été développée pour le marquage de composés bioconjugées. Les conditions particulièrement douces de l’alcoxycarbonylation intramoléculaire mise au point ont permis un marquage en dernière étape de synthèse. La diversification des structures des précurseurs a également été envisagée grâce à un nouveau couplage biarylique catalysé à l’or sous conditions photorédox. Enfin la fonctionnalisation de motifs BODIPY a conduit à de premières avancées pour l’obtention de sondes bimodales innovantes. / Positron Emission Tomography (PET) is a powerful molecular-imaging technique for physiological andbiological investigations in various areas. Due to the increasing need of this technique for in vivoapplications, there is always a demand for the development of new tracers and radiolabelingstrategies. In this context an original method was developed to introduce the 11C-radioisotope for thelabeling of bioconjugated compounds. The extremely mild conditions of this intramolecular Pdcatalyzedalcoxycarbonylation allowed to label these structures in the last step of the synthesis.Diversification of the available precursors was investigated by a novel biaryl cross coupling using goldcatalisis under photoredox conditions. Finally, preliminary studies for the functionalization of BODIPYcores were realized to obtain innovative bimodal probes.
30

Strategische Einbindung der Umformsimulation in die Entwicklungsprozesskette Karosserie

Maaß, Lena 20 May 2016 (has links)
Die Bauteileigenschaften von Bauteilen und Baugruppen im Karosseriebau werden maßgeblich durch die während des Tiefziehprozesses auftretenden Formänderungen und Verfestigungen beeinflusst. In der vorliegenden Arbeit wird daher die Umformsimulation in eine repräsentative virtuelle Prozesskette des Karosseriebaus integriert. Dazu wird zunächst die Datenübertragung zwischen den einzelnen Simulationsprogrammen in der Prozesskette Umformen - Fügen - Crash realisiert. Mit der anschließend durchgeführten Sensitivitätsanalyse wird festgestellt, welche Größen einen signifikanten Einfluss auf die Folgesimulationen haben. Aufbauend auf den Ergebnissen der Sensitivitätsanalyse wird eine Methode zur Gestaltung von einfachen Ankonstruktionen zur Verbesserung der Qualität der Ergebnisse der inversen Umformsimulation entwickelt und an einem Bauteil aus dem Karosseriebau validiert. Mit den durch die einfache Ankonstruktion erzielten Verbesserungen in den Ergebnissen der inversen Umformsimulation kann die entwickelte Methode einen Beitrag zur Erhöhung der Qualität der nachfolgenden Prozesssimulationen in der Prozesskette leisten.

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