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1
Sinha, Rajendra Prasad. "Studies on some transformative reactions of triterpenoids." Thesis, University of North Bengal, 1993. http://hdl.handle.net/123456789/816.
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Singha, Rabindranath. "Chemical transformation of carbocyclic compounds and development of novel reaction protocols." Thesis, University of North Bengal, 2021. http://ir.nbu.ac.in/handle/123456789/4348.
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Mothay, jyotsna. "Studies on the transformative reactions of carbocyclic compounds." Thesis, University of North Bengal, 2002. http://hdl.handle.net/123456789/771.
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Mandal, Amitava. "Transformative reactions of terpenoids and studies on their biological activity." Thesis, University of North Bengal, 2012. http://hdl.handle.net/123456789/1571.
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Amass, Dorothy Gwendoline. "Block co-polymerization by transformation reactions." Thesis, Aston University, 1996. http://publications.aston.ac.uk/9679/.
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The aim of this study was to use the transformation of anionic to metathesis polymerization to produce block co-polymers of styrene-b-pentenylene using WC16/PStLi and WC16/PStLi/AlEtC12 catalyst systems. Analysis of the products using SEC and 1H and 13C NMR spectroscopy enabled mechanisms for metathesis initiation reactions to be proposed. The initial work involved preparation of the constituent homo-polymers. Solutions of polystyryllithium in cyclohexane were prepared and diluted so that the [PStLi]o < 2x10-3M. The dilution produced initial rapid decay of the active species, followed by slower spontaneous decay within a period of days. This was investigated using UV/visible spectrophotometry and the wavelength of maximum absorbance of the PStLi was found to change with the decay from an initial value of 328mn. to λmax of approximately 340nm. after 4-7 days. SEC analysis of solutions of polystyrene, using RI and UV/visible (set at 254nm.) detectors; showed the UV:RI peak area was constant for a range of polystyrene samples of different moleculor weight. Samples of polypentenylene were prepared and analysed using SEC. Unexpectedly the solutions showed an absorbance at 254nm. which had to be considered when this technique was used subsequently to analyse polymer samples to determine their styrene/pentenylene co-polymer composition. Cyclohexane was found to be a poor solvent for these ring-opening metathesis polymerizations of cyclopentene. Attempts to produce styrene-b-pentenylene block co-polymers, using a range of co-catalyst systems, were generally unsuccessful as the products were shown to be mainly homopolymers. The character of the polymers did suggest that several catalytic species are present in these systems and mechanisms have been suggested for the formation of initiating carbenes. Evidence of some low molecular weight product with co-polymer character has been obtained. Further investigation indicated that this is most likely to be ABA block copolymer, which led to a mechanism being proposed for the termination of the polymerization.
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Patel, A. V. "Microbial transformation of spirostanes and related compounds." Thesis, University of Portsmouth, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375659.
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Clarke, P. D. "Transformation and addition reactions in the chromone series." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372132.
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Kanno, Hisashi. "In situ alcohol oxidation-transformation reactions using manganese dioxide." Thesis, University of York, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270357.
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Pariyar, Gyan Chandra. "Explorative studies on carbon hetero bond transformation reaction and carbon-hetero bond formation reaction." Thesis, University of North Bengal, 2018. http://ir.nbu.ac.in/handle/123456789/2813.
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Zhang, Junlong, and 張俊龍. "Macromolecular ruthenium porphyrin catalysts for organic transformation reactions: mechanistic andcatalytic studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31545725.
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LIN, PENG. "Enzyme cascade reactions on 3D DNA scaffold with dynamic shape transformation." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/265209.
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京都大学新制・課程博士
博士(エネルギー科学)
甲第23437号
エネ博第424号
新制||エネ||81(附属図書館)
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授 森井 孝, 教授 佐川 尚, 教授 片平 正人
学位規則第4条第1項該当
Doctor of Energy Science
Kyoto University
DFAM
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Shirsath, Sachin R. "Exploring new synthesis transformations employing p-quinone methides as versatile acceptors in 1,6-addition reactions." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2022. https://hdl.handle.net/20.500.12252/6219.
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Marfil, Vega Ruth. "Abiotic Transformation of Estrogens in Wastewater." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1289235973.
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Zhang, Junlong. "Macromolecular ruthenium porphyrin catalysts for organic transformation reactions mechanistic and catalytic studies /." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31545725.
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Doohan, Fiona Maria. "Molecular techniques for studing Fusarium ear blight of wheat." Thesis, Open University, 1997. http://oro.open.ac.uk/57682/.
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This work has compared polymerase chain reaction (PCR) assays and traditional visual disease assessment to evaluate the severity of Fusarium ear blight (FEB) ofwheat under field and glasshouse conditions. In a field trial, PCR analysis highlighted the problem of diagnosis of FEB of wheat based on visual disease assessment where natural inoculum was present. PCR-based analysis detected F. poae predominantly in the glumes and Microdochium nivale sub-species were predominantly found in the rachis component of ears. M nivale var. majus was more frequently observed than var. nivale (64 and 36 %, respectively). Quantitative PCR analysis and conventional visual disease assessment were used to evaluate fungicide efficacy against FEB of wheat caused by F. culmorum and F. poae in three glasshouse trials (1994/5-1996/7). Prochloraz and tebuconazole significantly decreased both visual symptoms of FEB and fungal DNA content of F. culmorum and F. poae ear blight of wheat. Overall, both fungicides appeared equally effective, although the efficacy ofthese fungicides was consistently greater as measured by PCR analysis rather than by visual disease assessment. Inoculation with F. culmorum significantly reduced yield (1000 grain weight) whereas inoculation with F. poae had no significant effect on yield. Fusarium culmorum was successfully transformed with the GUS reporter gene. GUS activity levels of transformants varied, but transformation did not affect pathogenicity on wheat seedlings. A GUS transformant was used to study the effectiveness of two fungicides against F. culmorum foot rot of wheat. Primers to the Tri5 gene were used to develop a PCR-based assay for the specific detection ofpotential trichothecene-producing Fusarium species. These primers were also used to develop an RT-PCR-based assay for the detection and semiquantification of F. culmorum Tri5 gene expression 'relative to p-tubulin gene expression' in RNA extracts from F. culmorum. This assay was used to show that time and fungicides can affect Tri5 gene expression in liquid culture.
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Onike, F. N. "Time-temperature-transformation (TTT) curves for and the thermal decompsition reactions of kaolinite, montmorillonite and two muscovite samples." Thesis, University of Hull, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377390.
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Yan, Zifei. "Equivalence Transformations for a System of a Biological Reaction Diffusion Model." Thesis, Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2201.
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A biological reaction diusion model has gained much attention recently. This model is formulated as a system of nonlinear partial dierential equations that contains an unknown function of one dependent variable. How to determine this unknown function is complicated but also useful. This model is considered in this master thesis. The generators of the equivalence groups and invariant solutions are calculated.
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GUSMAO, DA SILVA JORGE. "Transformation catalytique des huiles vegetales en gazole : mecanisme et optimisation des reactions d'hydrocraquage." Paris 6, 1986. http://www.theses.fr/1986PA066405.
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Etude experimentale des reactions d'hydrocrackage d'une huile vegetale en autoclave, sous pression d'hydrogene, entre 623 et 708**(o)k, en presence de catalyseurs hydrogenants. On a mis en evidence les sequences detaillees des reactions qui transforment les composes insatures et les triglycerides en hydrocarbures du type "gazole". Le deplacement de l'equilibre global vers la formation d'hydrocarbures a ete realise pour une pression finale d'hydrogene de 200 bars. Un taux de conversion proche de 100% molaire a ete obtenu pour deux huiles vegetales a 633**(o)k, avec des catalyseurs ni-mo/gamma -al::(2)o::(3) et ni-mo/sio::(2)-al::(2)o::(3) sulfures
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Sakurai, Shunya. "Development of Transformation Reactions with Alkylsilyl Peroxidesas Alkyl Radical Precursors under Cu Catalysis." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263490.
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Gonzalez, Richard. "Biocatalytic transformation of steroids using solvent-enhanced Beauveria bassiana." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1610.
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This dissertation describes efforts to improve the oxidative capacity of n-alkane- induced Beauveria bassiana; a fungus and a versatile whole cell biocatalyst used in the biotransformation of steroids. n-Hexadecane was used as the carbon source during the growth of B. bassiana, presumably to induce the expression of oxidative enzymes, thus enhancing the oxidation of unactivated carbons. Dehydroepiandrosterone (DHEA) is an essential endogenous male-hormone and serves as a metabolic intermediate in the production of more potent androgens. Using DHEA as a substrate also provides the opportunity to study the hydroxylation of an unfunctionalized carbon, an attractive reaction that produces valuable intermediates for chemical synthesis. Results showed that exposing and inducing cells in n-hexadecane improves the synthesis of 11α-hydroxy derivatives. Reactions were carried out with cells grown on n-hexadecane, resulting in 65 ± 6.3 % conversion of DHEA to androstenediol (40.3% mM) and 3β,11∝,17β- trihydroxyandrost-5-ene (22.8% mM), as determined by HPLC, NMR and LCMS analyses. However, experiments with non-induced cells resulted in a poor substrate conversion (17%). To extend use of B. bassiana to pharmaceutical applications, it was necessary to optimize reaction conditions such as biocatalyst preparation, substrate concentration, agitation reaction temperature and pH. Higher substrate conversion, selectivity and yield of desired product were achieved with the reactor arrangement of “Resting Cells”. The apparent rate of reaction fits a Michaelis-Menten kinetic model with a maximum reaction rate of 4.45 mM/day, revealing that the transformation of intermediate androstenediol to desired 3β,11∝,17β-trihydroxyandrost-5-ene is the limiting step in the reaction. Interestingly, when a diluted amount of substrate was used, a higher yield of 11∞-hydroxy steroid was achieved. Also, reactions at 26°C with pH ranges between 6.0 and 7.0, resulted in the highest conversion (70%) and the higher product yield (45.8%). The maximum conversion of DHEA (71%) was achieved in experiments with high biomass loading, and the increment of desired product yield (11∝-hydroxy) was directly proportional to the amount of biomass used. Moreover, a high VMax/KM value was achieved with high biomass yields. Interestingly, the changes in biomass yield did not have a considerable effect on reaction selectivity. The main drawbacks of biocatalysis for production of steroids were addressed and approaches to minimize the drawbacks have been presented. The production of desired product (11∝-DHEA) was significantly improved using cells previously adapted to n-hexadecane.
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Singha, Rabindranath. "Chemical transformation of carbocyclic compounds and development of novel reaction protocols." Thesis, University of North Bengal, 2021. http://ir.nbu.ac.in/handle/123456789/4326.
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Rasul, Mohammed Golam. "Phytochemical investigation of some medicinal plants transformative reaction on the isolated organic compounds and studied on their biological activities." Thesis, University of North Bengal, 2010. http://hdl.handle.net/123456789/1370.
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Smith, Donna Lee. "Development of novel metal-catalysed methods for the transformation of Ynamides." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8895.
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I. Rhodium-Catalysed Carbometalation of Ynamides using Organoboron Reagents. As an expansion of existing procedures for the carbometalation of ynamides, it was discovered that [Rh(cod)(MeCN)2]BF4 successfully promotes the carbometalation of ynamides with organoboron reagents. A variety of organoboron reagents were found to be suitable for this reaction, but mostly the use of arylboronic acids was explored. The developed methodology provides β,β-disubstituted enamide products in a regio- and stereocontrolled manner. II. Palladium-Catalysed Hydroacyloxylation of Ynamides. In the presence of palladium(II) acetate, ynamides successfully underwent a hydroacyloxylation reaction with a variety of carboxylic acids. This carboxylic acid addition occurred highly regio- and stereoselectively to provide α-acyloxyenamides. Applications of the α-acyloxyenamide products were also investigated. III. Rhodium-Catalysed [2+2] Cycloaddition of Ynamides with Nitroalkenes. A novel rhodium catalyst system has been developed in order to promote the [2+2] cycloaddition reaction between ynamides and nitroalkenes. The reaction provides cyclobutenamide products and was diastereoselective in favour of the trans cyclobutenamide. Both the ynamide scope and the nitroalkene scope of the reaction have been explored.
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Poupart-Lafarge, Henri. "Reaction and transformation of airlines in a deregulated environment : a strategy for Air France." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/34085.
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Cakir, Esen. "Synthesis Of Novel Chiral N,n-dialkyl Substituted 1,4-amino Alcohols And Applications In Asymmetric Transformation Reactions." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608484/index.pdf.
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Amino alcohols are valuable bioactive substances and frequently used as chiral catalyst in various asymmetric transformation reactions. In the synthetic route, the asymmetric synthesis of novel chiral N,N-dialkyl substituted chiral 1,4-amino alcohols are performed starting with meso-anhydride 38. Quinine-mediated desymmetrization of the anhydride with methanol afforded (2S,3R)-cis-monoester 39 with a high enantiomeric excess (up to 98% ee). Chemoselective amidation of hemiester with various N,N-dialkyl substituted amines resulted in amido esters and they were subjected to LAH reduction to afford chiral 1,4-amino alcohol ligands.
The activities of the chiral ligands, (2S,3R)-43, (2S,3R)-44, (2S,3R)-45, (2S,3R)-46 were tested in various asymmetric transformation reactions, i.e. asymmetric diethylzinc addition and asymmetric Diels-Alder reactions.
Keywords: 1,4-Amino alcohols, chiral ligand, asymmetric diethylzinc addition reaction, Diels-Alder reaction
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Isaksson, Dan. "Lipase catalysed reactions of terpenoids : formation of hemiacetal esters : resolution of cryptone and its transformation to cadinenes." Doctoral thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-588.
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Yeh, Xian-Li Johnson W. L. "Reaction of hydrogen with crystalline and amorphous alloys : crystal to amorphous transformation induced by hydrogen /." Diss., Pasadena, Calif. : California Institute of Technology, 1987. http://resolver.caltech.edu/CaltechETD:etd-03042008-144844.
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Grigorieva, Raisa. "Etude des transformations de phases dans le revêtement Al-Si lors d'un recuit d'austénitisation." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL019N/document.
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De nos jours on utilise de plus en plus les aciers pré-revêtus dédiés aux applications pour emboutissage à chaud afin de protéger la surface de l’acier contre la décarburation et l’oxydation durant le traitement thermique. Le revêtement est déposé à chaud en continu par immersion de la bande d’acier dans un bain d’Al-Si. Pendant l’austénitisation le revêtement Al-Si se transforme par réactions d’inter-diffusion et de solidification. Ces réactions conditionnent la microstructure finale et en particulier la surface du revêtement, responsable des propriétés d’emploi telles que le soudage par point et l’adhérence peinture.A l’état de livraison le revêtement Al-Si contient les phases suivantes : des grains d’Al, l’eutectique ternaire Al-Fe-Si, une couche intermétallique ternaire Al-Fe-Si et une couche intermétallique binaire Al-Fe. Après austénitisation les phases se transforment en deux types d’intermétalliques : intermétalliques ternaires riches en Si et intermétalliques binaires pauvre en Si.Durant cette étude une identification complète des différentes phases a été établie. Les phases initialement riches en Si se transforment en phases fusibles par réactions eutectique ou péritectique. La présence de phase liquide accélère la diffusion locale de fer permettant aux phases riches en Si de garder leur contenu en Si pendant tout le traitement thermique. C’est la diffusion du fer qui stabilise les gradients en Si dans le revêtement, malgré les lois de diffusion classiques. En utilisant le diagramme de phases ternaire il a été démontré comment l’enrichissement en fer s’établit dans le revêtement tout en gardant l’équilibre aux interfaces entre les phases riches et pauvres en SiNowadays more and more pre-coated steels are applied in hot-stamping process to prevent the steel surface against iron oxidation and decarburization during the heat-treatment. The coating is deposited by hot-dipping the coil in an Al-Si bath. During the austenitization, the Al-Si coating transforms completely by inter-diffusion and solidification reactions, which define the final microstructure and particularly the top layer responsible for the in-use properties like spot welding and painting adhesion.At the delivery state, the Al-Si coating is a multiphase coating containing the following phases: Al-grains, Al-Fe-Si ternary eutectic phase, an Al-Fe-Si intermetallic layer and a binary Al-Fe interfacial layer. After the heat-treatment, all the phases transform into two types of intermetallic compounds: Si-rich ternary and Si-poor binary compounds.During this study, a complete identification of the different intermetallic phases has been conducted. Initial ternary Al-Fe-Si phases transform into fusible phases by eutectic or peritectic reaction. The presence of liquid state enables rapid local iron diffusion which allows to the Si-rich phases to keep their high Si content during the whole treatment. So the iron diffusion stabilizes the Si gradients in the coating despite the classical diffusion laws. Using the ternary phase diagram it was shown how iron enrichment in the coating proceeds by keeping thermodynamical equilibrium along the interfaces between Si-rich ternary and Si-poor binary phases. A phenomenological model of phase transformations explaining the formation of differente coating microstructures during the austenitization step is proposed
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Odabas, Serhat. "Asymmetric Synthesis Of N-aryl Substituted Chiral 1,4-amino Alcohol Derivatives And Applications In Various Asymmetric Transformation Reactions." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608489/index.pdf.
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The asymmetric synthesis of N-aryl substituted chiral 1,4-aminoalcohols and their applications in asymmetric borane reduction and enantioselective diethylzinc addition to benzaldehyde reactions were performed starting from meso anhydride 51 that is the cycloadduct of cyclopentadiene and maleic anhydride. The desymmetrization of meso-anhydride 51 was achieved by using quinine or quinidine with very high enantiomeric excess value (up to 98% ee) and with high chemicalb yield. The quinine-mediated desymmetrization of meso-anhydride 51 with methanol gave (2S,3R)-(-)-cis-monoester 52. The hemiester was subjected to chemoselective amidation with various types of N-aryl substituted amines and then, it was treated with LAH and followed by hydrogenation in the presence of palladium catalyst to get the chiral 1,4-amino alcohols. The catalytic effectiveness of these chiral 1,4-amino alcohol ligands, (2S,3R)-60, (2S,3R)-61, (2S,3R)-62 and (2S,3R)-63 were examined in asymmetric borane reduction and enantioselective diethylzinc addition to benzaldehyde reactions.
Keywords: Amino alcohol, chiral ligand, asymmetric reaction, borane reduction, diethylzinc addition
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Swarts, Andrew John. "Novel transition metal complexes based on N,N and N,P ligands as catalysts for ethylene transformation reactions." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86330.
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Moscu, Corcodel Alina. "Structural transformation under reaction conditions of supported PtSn nanoparticles characterized by in situ DRIFTS and kinetic modeling." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10177.
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La réaction d’oxydation sélective du CO par O2 en présence d’un excès d’hydrogène (PROX) est considérée comme une étape de purification essentielle de l’H2 à utiliser dans des piles à combustible. L’objectif de cette thèse est de mieux comprendre le mécanisme de cette réaction sur des catalyseurs bimétallique s à base de Pt et Sn. Des catalyseurs modèles Pt et Pt-Sn ont été synthétisés en deux étapes : (i) formation de nanoparticules (NP) métalliques colloïdales en suspension suivi par ( ii) l’imprégnation de ces particules sur des supports. L’adsorption du CO suivit par spectroscopie FT-IR en réflexion diffuse (DRIFTS) a été utilisée pour caractériser ces solides après une réduction permettant de reformer des phases d’alliage PtSn. L’analyse DRIFTS permet de caractériser la nature des sites de Pt présents, soit dans l’alliage, soit dans des phases pures de Pt. La chaleur d’adsorption du CO sur la phase d’alliage a été mesurée par DRIFTS, pour la première fois, et apparait bien plus faible que celle sur le Pt seul. De manière surprenante, la ségrégation de l’alliage en présence de CO/H 2 à des températures inférieur es à 175°C a été mise en évidence. Des mesures in situ DRIFTS de la réaction d’oxydation préférentielle du CO (PROX) indiquent que l’alliage se transforme rapidement en Pt et SnOx de par la présence de l’O2. Aucune indication de la présence d’alliage n’a jamais pu être obtenue sous PROX, indiquant que les meilleures propriétés catalytiques associés aux phases Pt-Sn sont dues à leur habilité à générer une nouvelle phase active Pt+SnOx lors de leur ségrégation. Un modèle microcinétique du PROX sur Pt+SnOx a été développé sur la base de ceux pertinents à l’oxydation du CO et PROX sur Pt seul, permettant une modélisation satisfaisante des données. Ce travail montre l’intérêt du couplage des méthodes spectroscopiques et cinétiques pour la compréhension de la structure des catalyseurs « au travail » et des mécanismes de réactions complexesThe selective oxidation of CO in the presence of a large excess of H2 (PROX) is considered as a crucial step in the purification of H 2 to be used in low-temperature fuel cells, which are clean sources of energy. The objective of this thesis was to better understand the reaction mechanisms taking place over promising catalysts based on Pt and Sn. Model Pt-Sn catalysts were prepared by a two-step method: (i) synthesis of metallic nanoparticules (NP) in a colloidal suspension followed by (ii) the deposition of these NPs onto a support. The first step of the method enabled to produce well-controlled Pt-Sn NPs in terms of size and composition. However, the NPs were partly destroyed during the deposition step followed by calcination, due to the reoxidation of Sn. The adsorption of CO followed by diffuse reflectance spectroscopy (DRIFTS) was used to characterize the nature of these solids following a reduction, which was able to regenerate an alloyed phase. The DRIFTS analysis enabled to discriminate between Pt in an alloyed phase and Pt on monometallic surfaces. The heat of CO adsorption measured by DRIFTS appeared to be much lower than that associated with the pure Pt phase. Surprinsingly, a segregation of Pt and Sn was observed under a CO/H2 mixture below 175°C. In situ analysis by DRIFTS of the PROX reaction indicated that the Pt-Sn alloy rapidly decomposed in the presence of O2, forming an intimate mixture of Pt and SnOx. No evidence of the presence of Pt -Sn alloyed phases could be obtained under PROX conditions, suggesting that the superior catalytic activity of the Pt –Sn materials were related to the Pt+SnOx mixture. A detailed PROX microkinetic model was developed over Pt+SnOx, based on those relevant to CO oxidation and PROX over pure Pt. This work epitomises the benefits in combining in situ spectroscopic study with kinetic modelling to better understand the structure of catalysts “at work” and reaction mechanisms
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Renou, Jean-Pierre. "Transformation génétique du chrysanthème (dendranthema grandiflora tzvelev) par agrobacterium." Angers, 1992. http://www.theses.fr/1992ANGE0009.
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La possibilité de transformation génétique du chrysanthème par agrobacterium a été étudiée. Des racines transformées ont pu être obtenues après inoculation avec a. Rhizogenes. Cependant la régénération de plantes transformées ne fut possible que dans de rares cas, après des temps de culture in vitro très longs. Des plantes transformées furent ensuite obtenues grâce à la souche d'agrobacterium. Eha 101 contenant un plasmide vecteur binaire qui comporte les gènes : npt ii, hpt et gus. Ces plantes ont été obtenues par sélection sur la résistance à la kanamycine. Différents protocoles ont conduit à l'obtention de plantes transformées, mais les conditions optimales furent l'inoculation de nuds immédiatement transférés sur un milieu sélectif contenant du cefotaxime. La transformation de plantes gus positives a été confirmée par hybridation moléculaire de l'ADN et amplification génique. Des plasmides vecteurs binaires contenant des gènes d'intérêt agronomiques ont été construits : les gènes rol a, b et c du ri tl-dna afin d'étudier leur effet sur le port de la plante, et le gène de la dihydroflavonol réductase de l'antirrhinum majus afin de permettre une modification de la couleur des fleurs de chrysanthème.
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Dussol, Damien. "Étude expérimentale et modélisation cinétique de la transformation d’éthanol en butadiène." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1221/document.
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Le butadiène est une molécule d’intérêt industriel qui peut être produite par le procédé dit Ostromislensky, avec l’éthanol en tant que matière première. Cette étude a pour objectif de développer un modèle cinétique pour expliquer la transformation d’un mélange éthanol/acétaldéhyde en butadiène, dans le cadre de la seconde étape de ce procédé. Le modèle cinétique est basé sur un schéma réactionnel et un modèle de réacteur. Le schéma proposé comprend la voie de Gorin Jones, communément acceptée dans la littérature, et une toute nouvelle voie impliquant un intermédiaire buténone. Les étapes clés ont été étudiées spécifiquement via des tests dédiés. Le schéma décrit aussi les étapes amenant aux principaux produits secondaires. Il a été validé à partir d’une base de données expérimentale, générée en amont de l’étude sur une unité de type gaz/solide, lit fixe, isobare (3 bara) et isotherme, avec un catalyseur Ta2O5 SiO2. L’influence des conditions opératoires sur l’effluent a été observée pour trois ratios éthanol/acétaldéhyde et sur des gammes de PPH (1,1 à 8,1 g·gcata 1·h-1) et de températures (320 à 370 °C). Le réacteur (piston dispersif sans limitations diffusionnelles) intégrant des lois cinétiques d’ordre, a été modélisé à l’état permanent via un solveur LSODE. Les paramètres cinétiques ont été estimés via un optimiseur Levenberg Marquardt à partir de la base de données expérimentale. Le modèle cinétique obtenu, basé sur un schéma réactionnel inédit, est en capacité de représenter et de prédire les débits des composés principaux et les tendances et ordre de grandeurs des débits des composés minoritaires selon les effets de PPH, de charge et de température, excepté dans certaines conditions opératoires limites isoléesButadiene is a molecule of industrial interest that can be produced by the so-called Ostromislensky process, with ethanol as raw material. This study aims to develop a kinetic model to explain the transformation of an ethanol/acetaldehyde mixture into butadiene, as part of the second step of this process. The kinetic model is based on a reaction scheme and a reactor model. The proposed scheme includes the commonly accepted Gorin Jones pathway and a new pathway involving a butenone intermediate. The key steps were specifically studied via dedicated experiments. The scheme describes also steps leading to by products. It was validated from an experimental database, generated upstream of the study on a gas / solid type unit, fixed bed, isobaric (3 bara) and isothermal, with a Ta2O5 SiO2 catalyst. The influence of the operating conditions on the effluent was observed for three ethanol/acetaldehyde ratios and over ranges of PPH (1.1 to 8.1 g·gcata 1·h-1) and temperatures (320 to 370 °C). The reactor (plug flow without diffusional limitations) integrating kinetic laws of order, was modeled in the permanent state via a solver LSODE. Kinetic parameters were estimated via a Levenberg Marquardt optimizer from the experimental database. The kinetic model obtained, based on a brand new reaction scheme, is able to represent and predict the flow rates of the main compounds and the trends and orders of magnitude of the flow rates of the minority compounds according to the effects of PPH, charge and temperature, except under certain isolated operating conditions
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Adenot, Aurélien. "Activation et transformation catalytique de SO₂ par des composés organométalliques et organiques." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASF014.
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Produit notamment lors de la combustion de ressources fossiles carbonées contenant des impuretés soufrées, le dioxyde de soufre (SO₂) est l’un des polluants majeurs de notre atmosphère. Toxique à la fois pour l’homme et pour l’environnement, sa conversion représente donc un enjeu majeur. De fait, son utilisation en tant que source de soufre pour la chimie fine revêt un triple intérêt : économique, sanitaire et écologique. Dans cette optique, nous nous sommes intéressés à la formation de sulfones à partir de SO₂, et ce grâce à l’usage de catalyseurs métalliques et d’organosilanes, composés nucléophiles doux, non toxiques et peu coûteux. Nous avons également étudié l’interaction entre le SO₂ et des paires de Lewis frustrées, ouvrant la voie à des réactions organocatalysées de valorisation du SO₂. Le développement de tels processus nécessite une compréhension détaillée de la réactivité du SO₂ et des mécanismes réactionnels d’activation et de transformation de ce gaz. Ainsi, une attention particulière a été apportée à l’étude du fonctionnement de ces réactionsNotably produced during the combustion of fossil carbon resources including sulfur impurities, sulfur dioxide (SO₂) is one of the major pollutants in our atmosphere. Toxic for both humans and the environment, its conversion represents thus a major challenge. Indeed, its use as a source of sulfur for fine chemicals offers a triple benefit : economic, health and ecological. With this in mind, we took an interest in the formation of sulfones from SO₂, through the use of metallic catalysts and organosilanes, which are mild, non-toxic and inexpensive nucleophilic compounds. We also studied the interaction between SO₂ and frustrated Lewis pairs paving the way for organocatalyzed SO₂ value-adding reactions. The development of such processes requires a detailed understanding of SO₂ reactivity and of mechanisms of activation and transformation of this gas. Therefore, a particular attention has been paid to the study of these reactions operating modes
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Yazbek, Lindsey Danese. "Hydrogeochemical Factors Influencing Metal Transport and Transformation in a Stream Impaired by Acid Mine Drainage." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent1564478839556002.
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Tavitian, Bernard. "Etude par spectroscopie differentielle infrarouge a transformee de fourier des reactions primaires de la photosynthese." Paris 6, 1987. http://www.theses.fr/1987PA066642.
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Ruiz, Johal. "Nouvelles synthèses par catalyse de composés organosilicés et leur transformation en fragments de polycétides." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S138/document.
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La réaction d'aldolisation est une des méthodes les plus importantes et plus utilisées pour former des liaisons C-C. La réaction tandem d'isomérisation-aldolisation catalytique d'alcools allyliques permet d'effectuer cette réaction avec de nombreux avantages synthétiques et nous avons préparé par ce moyen des beta-hydroxyacylsilanes à partir d'alpha-hydroxyallylsilanes. Tout d'abord, nous avons cherché à mettre au point une version catalytique asymétrique de cette réaction tandem et nous avons aussi synthétisé des beta-hydroxyacylsilanes par aldolisation directe. Ensuite, nous avons utilisé des alpha-hydroxyallylsilanes pour préparer des aldolsalpha-silylés au moyen de réactions d'époxydation. Dans une troisième partie, nous avons synthétisé des aldols à partir de beta-hydroxyacylsilanes protégés de manière simple et efficace, ce qui nous a permis d'effectuer des réactions d'aldolisation itératives. Nous avons illustré le potentiel de cette méthode par la synthèse d'un fragment de (±)-pironetine. Enfin, nous avons synthétisé, à partir des mêmes beta-hydroxyacylsilanes protégés, des éthers d'énol silylés qui ont été ensuite utilisés avec succès comme substrats pour des réactions de MukaiyamaThe aldol reactions is one of the most important and commonly used methods to form C-C bonds. The catalytic tandem isomerization-aldol reaction of allylic alcohols allows to perform this reaction with many synthetic advantages. Thus, we have prepared by this method beta-hydroxyacylsilanes from alpha-hydroxyallylsilanes. First, we have attempted to develop a catalytic asymmetric version of this reaction, and also to synthesize beta-hydroxyacylsilanes by direct aldol reaction. Then, we used alpha-hydroxyallylsilanes to prepare alpha-silyl aldols trough epoxidation reactions. Next, we synthesized aldols from protected beta-hydroxyacylsilanes in a simple and efficient fashion which allowed us to perform iterative aldol reactions. We have illustrated the potential of this method by the synthesis of a fragment of (±)-pironetine. Finally, we have synthesized, from the same protected beta-hydroxyacylsilanes, silyl enol ethers that next have been used successfully as substrates for Mukaiyama aldol reactions
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Das, Saikat. "FUNDAMENTAL STUDIES OF SURFACTANT TEMPLATED METAL OXIDE MATERIALS SYNTHESIS AND TRANSFORMATION FOR ADSORPTION AND ENERGY APPLICATIONS." UKnowledge, 2015. http://uknowledge.uky.edu/cme_etds/48.
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This work addresses fundamental aspects of designing templates and curing conditions for the synthesis of mesoporous metal oxide thin films. The first section addresses selection of cationic-carbohydrate surfactant mixtures to synthesize templated silica thin films for selective adsorption of simple carbohydrates based on molecular imprinting. Nuclear magnetic resonance and fluorescence spectroscopy results suggest a novel structure for mixtures of alkyl glucopyranosides or xylopyranosides with cationic (trimethylammonium) surfactants. Despite thermodynamically favorable mixing, the carbohydrate headgroups in the mixed micelle adopt an inverted configuration with their headgroups in the micelle core, and therefore are inaccessible for molecular imprinting. This orientation occurs even when the alkyl tail length of the carbohydrate surfactant is greater than that of the cationic surfactant, but this limitation can be overcome by introducing a triazole linker to the carbohydrate surfactant. The next section addresses the effects of aging conditions on the structural and chemical evolution of surfactant templated silica thin films. The third section describes the synthesis of carbohydrate/cationic surfactant imprinted silica thin films with orthogonally oriented cylindrical pores by modifying the glass surface with a random copolymer. The last part of the dissertation addresses the effect of pore orientation on the transformation mechanism of block copolymer templated titania thin films during high temperature curing. Mesoporous titania thin films can be used for photochemical and solar cell applications, but doing so requires addressing the tradeoff between loss of mesostructural order and growth of crystallinity during thermal treatment. By using advanced x-ray scattering techniques it has been shown that the titania films with vertically oriented pores can better withstand the anisotropic stress that develops during thermal treatment compare to titania films with mixed pore orientation. For instance, films with parallel or mixed pores can only be heated at 400 °C for a brief time (~10 min) without loss of order, while orthogonally oriented films can be heated at 550 °C or greater for extended time periods (on the order of hours) without significant loss of long-range mesopore structure. Detailed kinetic modeling was applied to enable the comparison of activation energy for mesostructure loss in films as a function of pore orientation and thickness.
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Jewell, Kevin [Verfasser], and Thomas [Akademischer Betreuer] [Gutachter] Ternes. "Investigations of chemically and biologically induced transformation reactions of micropollutants during biological wastewater treatment processes / Kevin Jewell ; Gutachter: Thomas Ternes ; Betreuer: Thomas Ternes." Koblenz, 2017. http://d-nb.info/1138981656/34.
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Skoglund, Nils. "Ash chemistry and fuel design focusing on combustion of phosphorus-rich biomass." Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-88505.
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Biomass is increasingly used as a feedstock in global energy production. This may present operational challenges in energy conversion processes which are related to the inorganic content of these biomasses. As a larger variety of biomass is used the need for a basic understanding of ash transformation reactions becomes increasingly important. This is not only to reduce operational problems but also to facilitate the use of ash as a nutrient source for new biomass production. Ash transformation reactions were examined in the present work using the Lewis acid-base concept. The model presented in Paper I was further extended and discussed, including the definition of tertiary ash transformation reactions as reaction steps where negatively charged molecular ions, Lewis bases, other than hydroxides are present in the reactants. The effect of such reactions for bonding of various metal ions, Lewis acids, were discussed. It was found that the formation of various phosphates through secondary and tertiary ash transformation reactions is important for the behaviour of biomass ash in combustion. The suggested model was supported by findings in Papers II-VIII. The experimental findings in Papers II-VIII were discussed in terms of ash transformation reactions. The fuel design choices made to investigate the effect of phosphorus in particular on ash transformation reactions were high-lighted. Addition of phosphoric acid to woody-type and agricultural biomasses showed that phosphate formation has a large influence on the speciation of Si, S, and Cl. Co-combustion of a problematic agricultural residue with other biomasses showed that the relation between phosphorus, alkali and alkaline earth metal content is important. Co-combustion of biosolids with wheat straw was shown to greatly improve the combustion properties of wheat straw. It was suggested that fuel analyses should be presented using molar concentration (mole/kg) in diagrams based on ash transformation reactions and elements forming Lewis acids or bases. This may facilitate the assessment of the combustion behaviour of a fuel. Some comments were made on fuel design and additives, specifically pointing out that phosphorus content should always be carefully considered in relation to alkali and alkaline earth metals in fuels and fuel blends.
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ROUSSELET, GUILHEM. "Nouvelles reactions cupro-catalysees des amines. Transformation des amines tertiaires et des n-oxydes en ions iminiums, epoxydation intramoleculaire. Synthese et utilisation synthetique des amidines." Paris 6, 1996. http://www.theses.fr/1996PA066368.
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Les sels cuivriques ainsi que l'oxygene moleculaire en presence de sels cuivreux oxydent la trimethylamine en ion n,n-dimethyliminium. Ce resultat conduit a la description d'un modele biomimetique de l'oxydation des amines tertiaires par les cupro-enzymes laccase et ceruloplasmine humaine. L'etude de la transformation des n-oxydes d'amines par les sels de cuivre a permis la mise au point d'une nouvelle voie d'acces aux ions iminiums. L'oxydation des 1-methyltetrahydropyridines resultant de l'interaction de l'oxygene moleculaire sur les sels cuivreux, et la transformation de leurs n-oxydes par les sels de cuivre conduisent a la formation d'epoxydes. Une meme espece active du cuivre, formellement de degre d'oxydation 3, est responsable de ces deux reactions. Les sels cuivreux catalysent la formation des amidines par condensation directe des amines sur les nitriles. La mesure de la constante de complexation des sels cuivreux par les amidines a permis de rationaliser le role du cuivre dans cette premiere synthese generale des amidines en une etape. Nous presentons de nouvelles reactions qui valorisent les amidines comme intermediaires de synthese, en particulier par reduction (synthese d'amines tertiaires par n-alkylation reductrice des nitriles) et par oxydation (heterocycles polyazotes, derives fonctionnalises 1,2)
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Breslin, Michael Craig. "Transformation Kinetics of Al2O3/Al Co-Continuous Ceramic/Metal Composite Materials (C4) Produced by a Displacement Reaction Between Liquid Al and Fused SiO2." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392902805.
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Dandach, Amar. "Transformation de la cellulose en bioproduits : une approche intégrée couplant la catalyse enzymatique et la catalyse hétérogène." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1129.
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Ces travaux de thèse portent sur la possibilité de combiner la catalyse hétérogène et la catalyse enzymatique dans une réaction en cascade de transformation de la cellulose en produits d’intérêt. Le prétraitement enzymatique (Celluclast, un cocktail de cellulases) a été choisi comme première étape de transformation de la cellulose en vue de la fragiliser; elle est réalisée dans une solution tampon d’acide acétique et d’acétate de sodium à pH 4,75, à 50°C. Cette étape produit principalement du glucose et modifie structurellement la cellulose résiduelle en diminuant seulement son degré de polymérisation (DP), fournissant de nouvelles extrémités réductrices sans toucher sa cristallinité. L’identification des verrous de la deuxième étape de catalyse hétérogène, réalisée en autoclave à une température supérieure ou égale à 190°C, a consisté à trouver un catalyseur hétérogène qui peut tolérer le milieu réactionnel enzymatique tamponné, qui peut avoir une activité catalytique favorisée sur les celluloses de DP inferieurs et qui peut valoriser le glucose obtenu dans des conditions identiques à la cellulose. Parmi les différentes familles de catalyseurs testés, le catalyseur métallique à base de Pt/charbon, s’est révélé plus efficace que les catalyseurs acides de Lewis et de Brønsted en raison de sa résistance au milieu tamponné et de sa capacité à convertir la cellulose et le glucose dans des conditions identiques malgré l’insensibilité de ce type de catalyseur de la diminution du DP de la cellulose prétraitée. Il a permis de convertir sélectivement la cellulose en propylène et éthylène glycols à 240°C dans une transformation cascade incluant une étape enzymatique suivie d’une étape catalytique hétérogèneThis thesis deals with the possibility of combining heterogeneous catalysis and enzymatic catalysis in a cascade reaction for cellulose transformation into value-added products. The enzymatic pretreatment was chosen as the first cellulose transformation step to weaken the cellulose structure which is carried out in a buffer solution of acetic acid and sodium acetate at a pH 4.75, at 50°C. This step is selective, producing mainly glucose, and it has structurally modified the residual cellulose by only decreasing its degree of polymerization (DP) by providing new reducing ends without affecting its crystallinity. The challenges of the second step, heterogeneous catalysis, which is done in a closed autoclave at a temperature greater than or equal to 190°C, were then to find a heterogeneous catalyst that can tolerate the buffered enzyme reaction medium, that can have a favored activity on lower DP celluloses and that can valorize the obtained glucose and cellulose in identical conditions. Among the different families of catalysts tested, the metallic catalyst based on Pt/carbon was shown to be more efficient than the other Lewis and Brønsted acid catalysts due to its resistance to the buffer medium and its abilities to valorize glucose and cellulose in equivalent conditions despite the independence of this type of catalyst to the reduction of the DP of the pretreated cellulose. It allowed to selectively convert cellulose into propylene and ethylene glycols at 240°C in a cascade reaction including an enzymatic catalytic step and a heterogeneously catalyzed one
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Malki, Abdelhafid. "Transformation électrocatalytique de produits issus de la biomasse : oxydation du fructose sur électrodes d'or et de platine." Poitiers, 1988. http://www.theses.fr/1988POIT2274.
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L'oxydation electrochimique du fructose en milieu basique et en milieu acide est realisee: une etude cinetique est effectuee, on etudie la modification des proprietes catalytiques superficielles des electrodes par adjonction d'adatomes, on fait plusieurs electrolyses a potentiel programme montrant que l'on obtient par cette reaction un melange d'acides gluconique, tartrique et citrique
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Doridot, Gabriel. "Etude de la transformation d'aminocyclopropanes élaborés dans le cadre d'une stratégie de synthèse de 14-azastéroïdes." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00937934.
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Au cours de ces travaux de thèse, une voie de synthèse de différentes cyclopropylamines a été développée. Leur fonctionnalisation a ensuite été mise en œuvre à l'aide de réactions de métallation ou de couplages croisés catalysés au palladium. Les cyclopropylamines ainsi fonctionnalisées furent alors soumises à des conditions de cyclisation dans le but d'obtenir tout ou partie d'une structure 14-azastéroïde. Si notre modèle, dont la synthèse s'est construite autour d'une aniline, nous a permis d'obtenir la structure des cycles B, C et D d'un 14-azastéroïde, nous n'avons pas été en mesure d'obtenir la structure dans sa totalité en partant d'une naphtylamine. Nous avons cependant dans ce cas obtenu un arrangement original pentacyclique comportant un motif cyclobutane. Nous avons enfin réalisés des travaux sur des réactions de type condensation, principalement entre divers dérivés d'aniline et le pyruvate d'éthyle. Lors des résultats préliminaires, nous avons cette fois encore majoritairement obtenu des structures comportant un motif cyclobutane et non celles se rapprochant des azastéroïdes.
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Hager, Veit [Verfasser]. "Stability and Deactivation Behavior of Supported Ionic Liquid Phase (SILP) Catalysts and Solid Catalyst with Ionic Liquid Layer (SCILL) Catalysts in Transformation Reactions of Alkenes and Alkynes / Veit Hager." München : Verlag Dr. Hut, 2020. http://d-nb.info/1222351870/34.
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Hakala, Jacqueline Alexandra. "The abiotic transformation of nitroaromatic pesticides by Fe(II) and dissolved organic matter." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1198087788.
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Stadlmair, Lara Fabienne [Verfasser], Thomas [Akademischer Betreuer] Letzel, Jörg [Gutachter] Drewes, Thomas [Gutachter] Letzel, and Peter [Gutachter] Schröder. "Enzymatic Transformation of Trace Organic Chemicals : Characterization of Reaction Mechanisms using Mass Spectrometric Technologies / Lara Fabienne Stadlmair ; Gutachter: Jörg Drewes, Thomas Letzel, Peter Schröder ; Betreuer: Thomas Letzel." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1166315142/34.
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Hernoux-Villière, A. (Audrey). "Catalytic depolymerisation of starch-based industrial waste:use of non-conventional activation methods and novel reaction media." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526201634.
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Abstract The rapid increase of energy demand for transportation generates a rise of environmental pollution, stimulating the development of alternative sources of energy. Biomass is considered as the main organic carbon source of energy to substitute petroleum permitting sustainable production of chemicals and transportation fuels. Biowastes, residues and non-edible feedstock possess high potential resources avoiding food competition. This research aims to convert starch-based industrial waste, potato peels, into reducing sugars and platform molecules, such as glucose. These high added-value chemicals can further be transformed into chemicals and fuels. Catalytic conversion of starch, the main constituent of potato peels, was activated with non-conventional technologies to enhance the depolymerisation rate and to reduce energy consumption according to the principles of green chemistry. Depolymerisation of starch was first performed in acidic water as reaction medium assisted with ultrasonic and/or microwave irradiation. Ultrasonic irradiation enhanced mass transfer of heterogeneous system, whereas the use of microwaves improved heat transfer in the reaction medium. The frequency applied leads to different effects on heterogeneous systems: low frequencies irradiation (below 100 kHz) generates turbulences resulting in enhanced transport properties, whereas higher frequencies produce chemical effects. Catalytic conversion of starch into reducing sugars required more energy than individual irradiation could provide. Simultaneous irradiation, combining ultrasound and microwave or several ultrasonic frequencies, on potato peels led to 50% yield of sugars without former separation processes, at moderate temperature. A weak synergetic effect was only observed with potato peels. The second part of this research is dedicated to study the effect of catalytic reaction medium (acids, ionic liquids). More appropriate systems possess the ability to dissolve and hydrolyse carbohydrates: specific ionic liquids. A room-temperature ionic liquid and a task-specific ionic liquid were selected for their solvability properties to dissolve and depolymerise starch present in potato peels. The depolymerisation of starch in the task-specific ionic liquid generated a yield of 43% of sugars, without former separation processTiivistelmä Liikenteen energiantarpeen nopea kasvu on johtanut päästöjen sekä ympäristösaasteiden lisääntymiseen. Biomassa on merkittävä raaka-ainevaihtoehto fossiiliselle hiilelle energian, kemikaalien ja liikenteen polttonesteiden tuotannossa. Erityisesti jätebiomassoilla on suuri merkitys biomassaraaka-aineena, koska ne eivät kilpaile ruoantuotannon kanssa. Väitöskirjatutkimuksen tavoitteena on tärkkelyspohjaisen teollisen jätteen, perunan kuorilietteen, katalyyttinen muuttaminen pelkistäviksi sokereiksi ja ns. platform-kemikaaleiksi, kuten glukoosiksi. Näistä korkean lisäarvon omaavista välituotteista voidaan edelleen valmistaa uusia biomassapohjaisia kemikaaleja ja polttoaineita. Tärkkelyksen, perunankuoren keskeisimmän aineosan, muuttaminen tehtiin tässä työssä mm. ultraääni- ja mikroaaltoavusteisella hajotuksella. Tavoitteena oli parantaa perunan kuorilietteen liukenemis- ja hajoamisnopeutta, lisätä saantoa sekä vähentää energian kulutusta vihreän kemian periaatteiden mukaisesti. Tärkkelyksen depolymerointi tehtiin ensin happokatalysoidussa liuoksessa ultraäänen ja/tai mikroaaltojen avulla. Ultraäänihajotus lisäsi aineensiirtoa heterogeenisessä reaktioväliaineessa, kun taas mikroaallot lisäsivät lämmönsiirtoa reaktioseoksessa. Eri ultraäänitaajuuksilla havaittiin olevan erilaisia vaikutuksia reaktioseokseen: alhaisilla taajuuksilla (alle 100 kHz) muodostuneet pyörteiset virtaukset edistivät aineensiirtoa ja korkeammat taajuudet kemiallisia ilmiöitä. Tärkkelyksen katalyyttinen depolymerointi vaatii enemmän energiaa kuin perinteisillä menetelmillä, kuten lämmittämällä, voidaan tuottaa. Yhdistämällä ultraäänen ja mikroaaltojen säteilytystä tai eri taajuuden omaavia ultraääniä, yli 50% perunajätteen tärkkelyksestä saadaan hajotettua pelkistyneiksi sokereiksi alhaisissa lämpötiloissa. Sen sijaan, ainoastaan perunankuorijätteellä havaittiin heikko synenerginen efekti mitä ei havaittu vertailunäytteellä (perunajauho). Toisena tavoitteena oli tutkia katalyyttisen reaktioseoksen (hapot, ioniset liuottimet) vaikutusta perunan kuorijätteen ja sen sisältämän tärkkelyksen liuottamiseen ja hajottamiseen. Erityisesti keskityttiin uusiin, spesifisiin ionisiin liuottimiin, jotka kykenevät samanaikaisesti sekä liuottamaan että hydrolysoimaan hiilihydraatteja. Huoneenlämpötilassa toimiva spesifinen ioninen liuotin valittiin sen katalyyttisten ominaisuuksien vuoksi. Tässä liuottimessa kuorilietteen sisältämästä tärkkelyksestä pelkistyneiden sokerien saanto oli 43%
Résumé La forte demande en énergie, la conscience sociale sur les changements climatiques mondiaux et l'épuisement à moyen terme des réserves d’énergies fossiles stimulent le développement de ressources alternatives. Considérée comme la principale source de carbone organique renouvelable, la biomasse peut être utilisée pour remplacer les carburants d’origine fossile tout en étant plus respectueuse de l’environnement. Des déchets biosourcés ainsi que des végétaux d’origine agricole ou forestière, appelés biomasse végétale, possèdent de fort potentiels évitant la concurrence alimentaire. Cette recherche a pour objectif de convertir un déchet industriel amidonné, des pelures de pommes de terre, en sucres réducteurs et molécules plateformes, tels que le glucose, qui par la suite peuvent être transformées en carburants de transport. L’utilisation des ultrasons ainsi que des micro-ondes, méthodes non-conventionnelles, en milieu acide ont permis d’améliorer le rendement ainsi que de réduire la consommation énergétique en accord avec les principes de la chimie verte. L’irradiation ultrasonore améliore le transfert de masse de systèmes hétérogènes, alors que les micro-ondes renforcent le transfert de chaleur dans le milieu réactionnel. De plus, la fréquence ultrasonore appliquée induit différents effets sur le système : les ultrasons de basse fréquence (en dessous de 100 kHz) génèrent des turbulences améliorant les propriétés de transport de la matière, alors que les ultrasons de plus haute fréquence produisent des effets chimiques, tels que la formation de radicaux libres. L’apport énergétique fourni par les ultrasons et micro-ondes seuls étant insuffisant, l’utilisation d’irradiations simultanées et combinées a conduit à un rendement de 50% de sucres depuis l’amidon, ne nécessitant aucun procédé de séparation pré-réactionnel. Un faible effet synergique a pu être observé sur la dépolymérisation de la pelure de pommes de terre. L’étude d’un milieu réactionnel permettant simultanément la dissolution ainsi que l’hydrolyse des glucides présents dans la matière première est développée dans la seconde partie de ce mémoire. Certains liquides ioniques possèdent les propriétés recherchées. La dépolymérisation de l'amidon dans un liquide ionique à tâches spécifiques a permis d’obtenir un rendement de 43% de sucres, sans aucun procédé de séparation pré-réactionnel
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Chen, Wan-Ru. "Interactions of tetracycline antibiotics with dissolved metal ions and metal oxides." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24698.
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Thesis (Ph.D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Chair: Huang, Ching-Hua; Committee Member: Kim, Jaehong; Committee Member: Pavlostathis, Spyros; Committee Member: Stack, Andrew; Committee Member: Yiacoumi, Sotira