Дисертації з теми "Cavitandi"
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Trusso, Sfrazzetto Giuseppe. "Progettazione e sintesi di nuovi cavitandi macrociclici." Thesis, Università degli Studi di Catania, 2011. http://hdl.handle.net/10761/122.
Повний текст джерелаQuinoxaline cavitands are synthetic molecular receptors with an hydrophobic cavity; these compounds are able to recognize several guests via hydrophobic interactions. Many examples of achiral recognition using these cavitands are reported in literature; at the best of our knowledge there are few reports about efficient chiral recognition. In this work new chiral quinoxaline based cavitands for enantiomeric recognition of functionalized aminoacids were synthesized. We introduced a chiral salen unit in the cavitand scaffold to allow the coordination of a metal cation and in particular an uranyl site, that permits the realization of an heteroditopic receptor, able to bind chiral ion pair of aminoacid salts. After this work we synthesized as a heteroditopic model a chiral uranyl salen complex containing two pyrenil arms, in order to elucidate the recognition mechanism of the hosts. To obtain new chiral materials silica based, we designed a new chiral cavitand functionalized with an aliphatic chain double bond terminated. This new surface was characterized by XPS, SEM and IR. Moreover we synthesized a cavitand with a fullerene unit, allow a new photosensitizer that generates singlet oxygen. This compound is able to perform an efficient DNA cleavage and should be applied in photodynamic therapy.
De, Zorzi Rita. "Structural studies on molecular recognition in protein complexes and supramolecular systems." Doctoral thesis, Università degli studi di Trieste, 2009. http://hdl.handle.net/10077/3082.
Повний текст джерелаIl riconoscimento molecolare tra due o più specie chimiche mediante interazioni non covalenti è il principale argomento di studio della chimica supramolecolare. Individuare i fini meccanismi di complementarietà che presiedono il processo di associazione molecolare è di fondamentale importanza sia per la comprensione di come funzionano i sistemi biologici naturali sia per lo sviluppo di nuovi sistemi supramolecolari artificiali. Nel presente lavoro di tesi, l’analisi delle interazioni che governano il riconoscimento molecolare sia in sistemi supramolecolari artificiali che in complessi proteici naturali è stata condotta attraverso la tecnica di diffrazione di raggi X da cristallo singolo, che consente la precisa identificazione delle interazioni coinvolte e dei gruppi funzionali responsabili del riconoscimento molecolare. In particolare, sono state analizzate le differenze tra due forme cristalline del citocromo c da Cuore di Cavallo, ottenute rispettivamente in ambiente ossidante e riducente in presenza di ioni nitrato. Lo ione nitrato è stato utilizzato in questo lavoro biocristallografico come sonda ionica per analizzare le variazioni della superficie elettrostatica connesse con il processo ossidoriduttivo del citocromo e per individuare i principali passaggi del meccanismo di riconoscimento molecolare in cui è coinvolto questo trasportatore di elettroni. Nell’ambito dello studio di sistemi in grado di mimare i sistemi biologici, sono stati analizzati anche complessi supramolecolari artificiali contenenti porfirine. Un nuovo versatile materiale nanoporoso è stato ottenuto attraverso utilizzo di interazioni non covalenti sinergiche tra calixareni e porfirine. Questa struttura supramolecolare che ricorda le zeoliti è stata successivamente funzionalizzata attraverso la diffusione di ioni metallici nei canali della struttura. Il materiale nanoporoso così ottenuto, contenente un pigmento porfirinico assieme ad uno ione metallico, è molto promettente per il successivo sviluppo di sistemi artificiali che coniugano la capacità di raccogliere la radiazione elettromagnetica nel campo del visibile con centri catalitici in grado di immagazzinare tale energia in legami chimici. In questo lavoro di tesi, un complesso, costituito da un nucleo formato da 4 ioni rutenio legati da ponti ossigeno, che ha dimostrato elevate capacità catalitiche nella reazione di produzione di ossigeno a partire dall’acqua in presenza di cerio (IV), è stato caratterizzato strutturalmente. Lo studio cristallografico ha permesso di ottenere dettagli strutturali importanti per la comprensione del meccanismo di reazione di tale complesso. Sensori che si avvalgono delle caratteristiche di reversibilità dell’interazione e di specificità del substrato tipiche della chimica supramolecolare possono essere ottenuti mediante la progettazione razionale di opportuni recettori molecolari. In questa tesi, cristalli isomorfi di un cavitando tetrafosfonato sono stati ottenuti in presenza di diversi alcoli guest, permettendo il confronto delle interazioni che determinano la formazione del complesso. Successivamente, sono stati portati a termine esperimenti di cocristallizzazione in presenza di coppie alcoliche, al fine di studiare la competizione tra queste specie per il sito del cavitando. Molecole a cavità che presentano funzionalità di host possono essere utilizzate anche nella progettazione di polimeri supramolecolari. Questo tipo di sistemi è particolarmente interessante per la possibilità di attivare o disattivare la polimerizzazione in risposta ad uno stimolo esterno. In questa tesi, un approccio di questo tipo è stato applicato alla sintesi di un omopolimero e di un eteropolimero.
Molecular recognition of two or more molecules through non covalent interactions is the field of supramolecular chemistry. The evaluation of the subtle mechanisms of complementarity inducing the molecular association has a fundamental importance in order to both elucidate biological processes and develop new artificial supramolecular systems. In the present thesis, analyses on various, artificial and natural, supramolecular systems, have been carried out using X-ray diffractions techniques on single crystals, that allow the precise determination of interaction geometries of the functional groups involved. In particular, structural differences between two crystal forms of Horse Heart cytochrome c, obtained in presence of nitrate ions, in an oxidizing and in a reducing environment, respectively, have been analysed. In this biocrystallographic work, nitrate ions have been used as ionic probes to analyse variations on the electrostatic surface due to the oxidoreductive processes of cytochrome and to identify the main steps of the molecular recognition mechanism, involving this electron transport protein. In order to develop systems able to mimicking biological processes, supramolecular complexes containing porphyrins have been analysed. A highly flexible nanoporous material has been obtained by synergistic non-covalent interactions of calixarene and porphyrin building blocks. This supramolecular zeolite-like structure has been easily functionalized by diffusion and coordination of metal ions in the large void channels of the crystals. This new nanoporous material, containing a porphyrinic dye together with a metal ion, is very promising for the development of artificial systems combining visible light harvesting properties and catalytic centres, able to store energy in chemical bonds. In this thesis, a complex constituted by a core of four ruthenium atoms bound through oxygen bridges, that demonstrated catalytic properties in oxygen evolving reactions from water oxidation in presence of Ce (IV), has been characterized through X-ray diffraction. The crystallographic analysis has allowed the determination of important structural details in order to understand the reaction mechanism of this complex. Sensing systems, that exploit the characteristics of reversibility of interactions and specificity of the substrate, typical of supramolecular chemistry, can be achieved with a rational design of suitable molecular receptors. In this thesis, isomorphic crystals of a tetraphosphonato cavitand have been obtained in presence of different alcoholic guests, allowing the comparison of interactions responsible for the complex formation. Afterwards, cocrystallizzation experiments in presence of two alcoholic species have been carried out in order to investigate the competition of these molecules for the cavitand site. Hollow molecules with host functionalities can also be exploited in the design of supramolecular polymers. These systems have attracted particular interest for the possibility of switch on/off the polymerisation after an external stimuli. In this thesis, a supramolecular approach has been applied in order to synthesize a homopolymer and a heteropolymer.
1981
Martínez, Rodríguez Luis. "Molecule and catalyst design for recognition and activation of small molecules." Doctoral thesis, Universitat Rovira i Virgili, 2016. http://hdl.handle.net/10803/398693.
Повний текст джерелаEngeldinger, Eric. "Cyclodextrin-derived metallo-cavitands." Université Louis Pasteur (Strasbourg) (1971-2008), 2003. https://publication-theses.unistra.fr/public/theses_doctorat/2003/ENGELDINGER_Eric_2003.pdf.
Повний текст джерелаThe present thesis deals with the multi-step synthesis of a series of ligands based on an a-cyclodextrin platform as well as the study of their coordination and catalytic properties. Two of the cyclodextrins, L1 and L2, are functionalised with two phosphite sidearms, -C6H4-o-OP(OPh)2, tethered to the A,D and A,C positions, respectively. Four other CDs bear PPh2 entities which have been directly anchored to the primary face: L3 (AD-disubstitution), L4 (AC-disubstitution), L5 (ACE-trisubstitution) and L8 (monosubstitution). Finally, two sterically hindered monophosphines, L6 and L7, have been obtained by bridging units AB and AC, respectively, with the PPh2- dianion. Despite their length, both diphosphites L1 and L2 readily form cationic chelate complexes with [Rh(NBD)(THF)2]BF4, in which the metal is part of a large macrocyle (29 and 24 members, respectively). The rhodium complex obtained with L2 catalyses the asymmetric hydrogenation of dimethylitaconate with a remarkable enantiomeric excess (83. 6%). The C2-symmetrical diphosphine L3 forms a (P,P,OMe) chelate complex with Ag+ which displays hemilabile behaviour, the four primary MeO groups alternatively binding the metal centre. Addition of various nitriles affords complexes in which the coordinated nitrile(s) is (are) always trapped inside the cavity. The latter highly contributes to the stability of the [AgP2(CH3CN)2]+ complex, a type of complex that had so far never been detected. Another unexpected property was uncovered when reacting diphosphines L3 and L4 with chloro complexes, LnMCl, which gave rise systematically to trans chelates, in which the M-Cl fragment is directed towards the cavity interior. The particular orientation of the M-Cl bond results from weak interactions between the coordinated chloride and two inner-cavity H-5 protons. Such interactions inside a CD are unprecedented. In both monophosphines, L6 and L7, synthesised by diastereospecific capping, the phosphorus lone pair is pointing towards the CD axis. This feature allows formation of self-inclusion complexes
Berghaus, Carsten. "Tetrapeptido-Methylendioxyresorc[4]arene chirale Cavitanden /." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968375375.
Повний текст джерелаEl, Moll Hani. "Synthèses et propriétés catalytiques de cavitands résorcinaréniques." Strasbourg, 2009. http://www.theses.fr/2009STRA6118.
Повний текст джерелаFranc, Jean-Pierre. "Etude physique d'écoulements cavitants." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37598038p.
Повний текст джерелаScott, Michael P. "Synthesis and Properties of Conformationally Restricted Cavitand Systems." Phd thesis, Canberra, ACT : The Australian National University, 2017. http://hdl.handle.net/1885/154341.
Повний текст джерелаDelannoy, Yves. "Modélisation d'écoulements instationnaires et cavitants." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0070.
Повний текст джерелаMarie-Magdeleine, Artem. "Caractérisation des fonctions de transfert d'organes hydrauliques en régimes cavitant et non-cavitant." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-01011968.
Повний текст джерелаPodkoscielny, Dagmara Izabella. "Encapsulation of Redox Active Centers by Deep-Cavity Cavitands." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/244.
Повний текст джерелаLeaym, Xiaoxuan. "Synthesis and applications of novel resorcin[4]arene cavitands." Diss., Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/745.
Повний текст джерелаDubessy, Béatrice. "Synthèse, complexation et auto-association de cavitands phosphorés fonctionnalisés." Lyon, École normale supérieure (sciences), 2006. http://www.theses.fr/2006ENSL0383.
Повний текст джерелаHermann, Keith R. "Novel Architectures in Cavitand Chemistry: Shaping Molecular Inner Space." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406148569.
Повний текст джерелаJenkins, Stephen. "First steps towards the controlled synthesis of calixresorcinarenes through poly-resorcinilic oligomers." Thesis, Brunel University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318424.
Повний текст джерелаChopra, Naveen. "Cavitand-based molecular hosts, hemicarceplexes, double carceplexes, and large carceplexes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25032.pdf.
Повний текст джерелаMezo, Adam Robert. "Study of cavitand-based de novo four-helix bundle proteins." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0024/NQ38945.pdf.
Повний текст джерелаZhang, Xinlei. "Optimisation de la modélisation RANS d'écoulements cavitants." Thesis, Paris, ENSAM, 2019. http://www.theses.fr/2019ENAM0060.
Повний текст джерелаTurbulent cavitating flows occur in many engineering practical applications such as pumpsand propellers. In these devices, the collapse of the cavitation bubbles combines with instabilities atmultiple scales produce major detrimental effects like flow rate fluctuations, noise, vibrations, anderosion. It is thus essential to accurately predict the behavior of unsteady cavitation, thereby reducingtheir consequences for the machinery. To simulate the turbulent cavitating flows, the most commonlyused approach is still the Reynolds-averaged Navier-Stokes (RANS) method coupled with homogeneouscavitation models, due to its computational tractability. However, it is a consensus that the RANS modelsare not accurate for the complex flows in the presence of adverse pressure gradients leading to flowseparation and recirculation. This limitation leads to the poor prediction on the interactions betweencavitation and turbulence in cavitating flows. Hence, it is necessary to quantity and reduce theuncertainties in the RANS model and thus improve the predictive performance, either with an empiricalapproach or data assimilation (DA) methods. In this thesis, we investigate the applicability of suchmethods for turbulent flows with the objective of introducing the data-driven method into cavitatingflows. Specifically, we first apply the hybrid DA method, ensemble based variational method, toreconstruct the flow field in convergent-divergent channel, through inferring optimal inlet velocity andmodel corrections from observation data. Further, we proposed a regularized ensemble Kalman methodcapable of enforcing the regularization constraints for ill-posed inverse problems. Also, variousensemble-based DA methods are evaluated for uncertainty quantification in CFD applications. Finally, anew empirical modification of the turbulent viscosity is proposed for cavitating flows based onexperimental measurements
Charlesy, Nicolas. "Modélisation diphasique d'écoulements cavitants avec effets thermodynamiques." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0159.
Повний текст джерелаLi, Na. "Resorcinarene-Based Cavitands: From Structural Design and Synthesis to Separations Applications." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3520.
Повний текст джерелаMayo, Dennis H. "Solvent and protonation effects on a resorcin[4]arene based cavitand." Connect to resource, 2006. http://hdl.handle.net/1811/6456.
Повний текст джерелаTitle from first page of PDF file. Document formatted into pages: contains 29 p.; also includes graphics. Includes bibliographical references (p. 28-29). Available online via Ohio State University's Knowledge Bank.
Harthong, Steven. "Les phosphonatocavitands pour la conception de récepteurs chiraux et de capsules supramoléculaires." Lyon, Ecole normale supérieure, 2010. http://www.theses.fr/2010ENSL0540.
Повний текст джерелаThe phosphonatocavitands are molecules which possess a lipophilic molecular cavity combined with several "hard" phosphorylated (P=O) binding sites that can be oriented towards the inside of the cavity. These particular cavitands show good binding properties towards alcohols, metal ions and more interestingly towards ammonium. They were hitherto synthetised in tretrafunctionnalized form by phosphorylated groups in stereochemistry i ; i made a synthesis path which allowed to obtain selectively di and trifunctionnalized compounds while maintaining the stereochemistry i of the bridges. I then demonstrated the formation of non covalent supramolecular capsules in solution, without any addition of substrates. The study of the capsules binding properties led to the building of a gyroscopic system. Subsequently these partially phosphorylated cavitands have been used so that new functionalities were added to them. I grafted a N-methylpicolium group to a triphosphonatocavitand to obtain, by self-assembling, a dimeric species. I noticed that the dinner could evolve in oligomeric species with a higher molecular weight in certain solvent conditions. The addition of a quinoxaline group or a different phosphoralyted group to a diphosphonatocavitand led to obtain chiral cavitands in racemic form by desymmetrization of the aromatic cavity. The first results obtained during chiral ammonium complexation experiment show an enantioselectivity, these cavitands could be used for selective recognition of ammonium or alcohol enantiomers. Eventually, mixed phosphoralyted cavitands, which possess both phosphoryl and thiophosphoryl groups, were prepared. Their binding properties have not been studied yet
Westcott, Aleema. "Cyclotriveratrylene-based cavitands and other tripodal ligands for coordination polymers and polyhedra." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485629.
Повний текст джерелаDelangle, Pascale. "Conception et étude de nouveaux récepteurs de cations : hémisphérands et cavitands phosphorés." Lyon, École normale supérieure (sciences), 1996. http://www.theses.fr/1996ENSL0048.
Повний текст джерелаGramage-Doria, Rafael. "Large cavity cyclodextrin-based macrocyclic ligands : synthesis, coordination and catalytic properties." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00767168.
Повний текст джерелаIoup, Sarah E. "Water-Soluble Deep-Cavity Cavitands: Synthesis, Molecular Recognition, and Interactions with Phospholipid Membranes." ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1572.
Повний текст джерелаHolman, K. Travis. "The host-guest chemistry of new members in the cyclotriveratrylene family of cavitands /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924887.
Повний текст джерелаMejri-Chtioui, Imène. "Analyse de l'écoulement instationnaire cavitant dans les inducteurs." Phd thesis, Paris, ENSAM, 2006. http://pastel.archives-ouvertes.fr/pastel-00001944.
Повний текст джерелаOshovsky, Gennady Veniaminovich. "Cavitand-based anion receptors and self-assembled (hemi)capsules in polar competitive media." Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/55450.
Повний текст джерелаHusain, Ali Husain. "Spatially Directional Resorcin[4]arene Cavitand Glycoconjugates for Organic Catalysis in Aqueous Media." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6261.
Повний текст джерелаAtkins, Joseph. "Synthesis and properties of resorcin[4]arene based quadrupoles and dimeric electrostatic capsules." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1398.
Повний текст джерелаFrikha, Sobhi. "Étude numérique et expérimentale des écoulements cavitants sur corps portants." Phd thesis, Paris, ENSAM, 2010. http://pastel.archives-ouvertes.fr/pastel-00544746.
Повний текст джерелаCampos, Amezcua Rafael. "Analyse des écoulements cavitants stationnaires et instationnaires dans les turbomachines." Phd thesis, Paris, ENSAM, 2009. http://pastel.archives-ouvertes.fr/pastel-00005285.
Повний текст джерелаAniol, Alexandra Katharina [Verfasser], Martin [Gutachter] Feigel, and Gerald [Gutachter] Dyker. "Unsymmetrische Cavitanden / Alexandra Katharina Aniol ; Gutachter: Martin Feigel, Gerald Dyker." Bochum : Ruhr-Universität Bochum, 2017. http://d-nb.info/1125106093/34.
Повний текст джерелаDalfré, Filho José Gilberto 1976. "Equipamento tipo jato cavitante para avaliação de desgaste por cavitação." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258407.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil
Made available in DSpace on 2018-08-04T10:56:38Z (GMT). No. of bitstreams: 1 DalfreFilho_JoseGilberto_D.pdf: 10243119 bytes, checksum: 5829e5204ff010a8a6d3e3a1d85f4916 (MD5) Previous issue date: 2005
Resumo: O equipamento tipo jato cavitante utiliza um bocal especialmente projetado para simular o fenômeno da cavitação desgastando uma amostra em um período de tempo curto. Isso ocorre, sobretudo, devido à magnitude da velocidade. Para maior eficiência do jato cavitante é necessária uma combinação da geometria do bocal, do diâmetro do orifício e da pressão disponível. No caso das estruturas hidráulicas se verifica o efeito simultâneo do fenômeno da cavitação e do impacto de um jato de alta velocidade. O objetivo deste trabalho foi desenvolver um equipamento tipo jato cavitante para avaliar o desgaste ocasionado pela cavitação em amostras de concreto. O estudo foi realizado no Laboratório de Hidráulica e Mecânica dos Fluidos da Faculdade de Engenharia Civil. A instalação permite variar os parâmetros de ensaio, de forma a obter a máxima eficiência do equipamento e definir o comportamento da amostra. O índice de cavitação de 0,14 é adequado aos ensaios em concretos de estruturas hidráulicas. Recomenda-se uma velocidade do jato em torno de 150 m/s, a adoção de 0,05 m de distância entre o bocal e a amostra e o uso de bocal cônico de 132°, com arestas vivas. A partir dos testes realizados, sugere-se um tempo de ensaio de quatro minutos para avaliação da resistência dos materiais face à ação da cavitação. Conclui-se que o equipamento tipo jato cavitante se mostrou adequado e eficiente para avaliação do desgaste provocado pela ação da cavitação, em um tempo curto de ensaio. As características do banco de ensaio permitem que ele seja instalado em laboratório ou em campo
Abstract: The cavitating jet apparatus uses an especially projected nozzle to produce cavitation and have the advantage of induce cavitational flow with short time test. That is due, mainly, to the magnitude of velocity. In order to obtain great efficiency of the cavitating jet apparatus one has to combine the nozzle geometry, the orifice diameter and the necessary pressure. In hydraulic structures it is verified the simultaneous effect of the cavitation phenomenon and the impact of a high velocity jet. The objective of this work was to develop a cavitating jet apparatus to evaluate the erosion caused by cavitation in concrete samples. The study was carried out in the Hydraulics and Fluid Mechanics Laboratory of the Civil Engineering, Architecture and Urbanism College. The installation allows varying the tests parameters, to get the maximum efficiency of the equipment and to obtain the sample damage. A cavitation index of 0,14 showed to be a value where damage in hydraulics structures was presented. It is suggested to perform tests with a jet velocity of approximately 150 m/s, the adoption of 0,05 m of distance between the nozzle and the sample and also the use of conical 132° nozzle with sharp edges, which showed to be adequate to the laboratory experiment with concretes ordinarily used in hydraulic structures. According to the tests, it can be normalize the adoption of four minutes test for evaluation of the cavitation samples resistance. It is concluded that the cavitating jet apparatus is adequate and efficient for evaluation of erosion through cavitation action in a short time tests. The characteristics of the experimental installation allow its use either in laboratory or in field tests
Doutorado
Recursos Hidricos
Doutor em Engenharia Civil
Frei, Markus. "Organische Nanoschalter: Synthese neuartiger Resorcin[4]aren-Cavitanden und deren Konformationsgleichgewichte /." Zürich : ETH, 2005. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16387.
Повний текст джерелаMehal, Jean Elie. "Analyse de l'influence de rugosités organisées sur les écoulements cavitants instationnaires." Phd thesis, Ecole nationale supérieure d'arts et métiers - ENSAM, 2014. http://pastel.archives-ouvertes.fr/pastel-01062146.
Повний текст джерелаAbuzahra, Fakhry. "Etude Expérimentale des Processus d'Atomisation Textuels : Application à des Ecoulements Cavitants." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR028/document.
Повний текст джерелаTextural atomization designates the mechanism of drop peeling from the interface of a free liquid flow. This mechanismis controlled by the characteristics of the flow issuing from the injector and manifests at its vicinity. Almost uninvestigated,textural atomization is a rapid phenomenon, implies very small ligamentary structures and produces a mist of fine droplets.The work of this thesis is an experimental investigation of a textural atomization process observed on flows issuing fromcavitating injector. Three academic transparent atomizers are used and optical diagnostics are implemented: LDV (LaserDoppler Velocimetry) and PDPA (Phase Doppler Particle Analyzer) to describe the internal flow and the spray, respectively,and still imaging at high spatial resolution or high-speed imaging for the internal and external flows. A first observation revealsa strong link between the cavitation regime and the textural atomization process. An analysis implying the measurementof the variability of the internal flow and of the atomization process quantifies this link. Here, the atomization process isdescribed by the measurement of its scale distribution. Associated with the concept of equivalent system, this multi-scaleanalysis returns a mathematical expression for the investigated atomization process. This result is unprecedented. Completedby a mathematical description of the spray drop-diameter distribution, it offers a new support to build a model of ligamentaryatomization processes presented in this work and that connects ligament size and deformation to the drop populations. Thesefine analyses provide a better knowledge of the investigated atomization process. For instance, we learn that, at fixed flowrate, the height of the inlet pipe feeding the orifice has no influence on the atomization process. Furthermore, a criterion hasbeen established to identify the smallest ligament deformation scale implied in the drop production
Boitel, Guillaume. "Effet thermodynamique dans un inducteur cavitant : mesures embarquées de température." Grenoble INPG, 2007. http://www.theses.fr/2007INPG0049.
Повний текст джерелаThe present work is devoted to an analysis of thermodynamic effect in cavitating inducers of rocket engine turbopumps. This physical phenomenon, negligible in cold water, is characterized, in cryogenie fluids, by a significant cooling of the two-phase regions in comparison with the temperature of the surrounding liquid. The first part of this work deals with an assessment of the existing predictive models using, on the one hand, a detailed bibliographie study, and on the other hand, the results of two experimental campaigns of tests carried out on an inducer using water and Refrigerant 114. These experiments allowed us to derive an indirect estimation of the cavity temperature depression, using a dassical cavitation scaling law for the cavity length. The second part focuses on the design and the achievement of an experimental device to measure the temperature inside the leading edges cavities attached to the inducer blades
Tudisco, Cristina. "Chemical Engineering of Silicon for Supramolecular Recognition." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/938.
Повний текст джерелаVernetti, Samantha Sizemore. "Two New Resorcinarenes: A Pyridine & Acetic Acid Ligand for Metal Coordination and a Deep-Cavity Nitroquinoxaline Resorcinarene." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1279.pdf.
Повний текст джерелаZhang, Guangjian. "Etude expérimentale de la structure et de la dynamique des écoulements cavitants." Thesis, Paris, HESAM, 2020. http://www.theses.fr/2020HESAE050.
Повний текст джерелаCavitation is a complex phenomenon involving mass transfer between liquid and vapour phase at nearly constanttemperature. Advances in the understanding of the physical processes of cavitating flows are challenging, mainlydue to the lack of quantitative experimental data on the two-phase structures and dynamics inside the opaquecavitation areas. In this thesis, partial cavitation developed in small convergent-divergent (Venturi) channels wasstudied experimentally in detail for a better knowledge of the physical mechanisms governing the cavitationinstabilities. This was achieved by using an ultra-fast synchrotron X-ray imaging technique aided withconventional high speed photography and Particle Image Velocimetry. The main contributions of the presentstudy can be summarized as follows: (1) detailed description of the two-phase flow structures in quasi-stablesheet cavitation, which is characterized by a low-speed re-entrant flow existing continuously underneath thecavity; (2) analysis of the complex effect of cavitation on turbulent velocity fluctuations; (3) identification ofthree distinct mechanisms responsible for the transition of sheet-to-cloud cavitation, with a discussion of thedifferences between them; (4) analysis of the scale effect on cavitation in the studied Venturi flows
Znidarcic, Anton. "Un nouvel algoritme pour la simulation DNS et LES des ecoulements cavitants." Thesis, Paris, ENSAM, 2016. http://www.theses.fr/2016ENAM0056/document.
Повний текст джерелаCavitation-turbulence interactions are problematic aspect of cavitating flows which imposes limitations in development of better cavitation and turbulence models. DNS simulations with homogeneous mixture approach are proposed to overcome this and offer more insight into the phenomena. As DNS simulations are highly demanding and a variety of cavitation models exists, a tool devoted specifically to them is needed. Such tools usually demand application of highly accurate discretization schemes, direct solvers and multi domain methods enabling good scaling of the codes. As typical cavitating flow geometries impose limits on suitable discretization methods, compact finite differences offer the most appropriate discretization tool. The need for fast solvers and good code scalability leads to request for an algorithm, capable of stable and accurate cavitating flow simulations where solved systems feature multiplication of implicitly treated variables only by constant coefficients. A novel algorithm with such ability was developed in the scope of this work using Concus and Golub method introduced into projection methods, through which the governing equations for homogeneous mixture modeling of cavitating flows can be resolved. Work also proposes an effective and new approach for verification of the new and existing algorithms on the basis of Method of Manufactured Solutions
Louisnard, Olivier. "Contribution à l'étude de la propagation des ultrasons en milieu cavitant." ENSMP, 1998. http://www.theses.fr/1998ENMP0817.
Повний текст джерелаMerle, Lucie. "Étude expérimentale et modèle physique d'un écoulement cavitant avec effet thermodynamique." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0139.
Повний текст джерелаShraberg, Joshua. "A Computational Study of Procyanidin Binding to Histatin 5 and Thermodynamic Properties of Hofmeister-Anion Binding to a Hydrophobic Cavitand." ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1944.
Повний текст джерелаLusetti, Alberto. "Sviluppo e validazione di metodologie di analisi numerica per flussi cavitanti all'interno di iniettori ad alta pressione." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5807/.
Повний текст джерелаCoutier-Delgosha, Olivier. "Modélisation des écoulements cavitants : étude des comportements instationnaires et application tridimensionnelle aux turbomachines." Grenoble INPG, 2001. http://www.theses.fr/2001INPG0106.
Повний текст джерелаChen, Zhibing. "Synthesis and host-guest interaction of cage-annulated podands, crown ethers, cryptands, cavitands and non-cage-annulated cryptands." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4229/.
Повний текст джерелаAssis, Maiara Pereira 1987. "Avaliação de equipamento tipo jato cavitante para inativação de Escherichia Coli empregando múltiplos jatos." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258107.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-25T02:40:27Z (GMT). No. of bitstreams: 1 Assis_MaiaraPereira_M.pdf: 4163936 bytes, checksum: 61db4f21a77d3fbfc1e65f7eb123dbfe (MD5) Previous issue date: 2014
Resumo: As discussões acerca da escassez de água e da sua qualidade para consumo humano são primordiais no contexto da gestão dos recursos hídricos. A água lançada na forma de esgoto doméstico e industrial nos corpos hídricos representa uma ameaça à saúde pública. Contudo, a qualidade da água pode ser melhorada controlando-se a poluição e aprimorando-se as técnicas de inativação de microrganismos e de degradação de compostos, que consistem na destruição de microrganismos e de compostos químicos excedentes. Uma das técnicas alternativas de inativação e degradação é empregar o fenômeno da cavitação. A cavitação desenvolve altas tensões de cisalhamento no interior do fluido e, além do mais, pode envolver a liberação de radical hidroxila, que auxiliam na oxidação de compostos presentes na água. O objetivo deste trabalho foi desenvolver um equipamento tipo jato cavitante para a inativação de Escherichia coli, empregando uma nova configuração com múltiplos jatos. A nova configuração do equipamento foi testada e comparada com a configuração existente no Laboratório de Hidráulica e Mecânica dos Fluidos, na busca de uma eficiência ótima. Os resultados indicam uma dependência da inativação com a pressão do equipamento e a configuração de bocais. Um bocal com orifício único e pressões menores (até 15,00 MPa) ou um sistema de bocais tridimensional e pressões maiores (em torno de 30,00 MPa) obtiveram as melhores taxas de inativação. As eficiências energéticas do equipamento tipo jato cavitante para cada taxa de inativação foram verificadas. Neste caso, as melhores alternativas dependem do tempo de inativação requerido. O equipamento tipo jato cavitante mostrou-se como uma alternativa viável para a inativação de Escherichia coli e que pode ser empregado com outras técnicas de inativação
Abstract: Discussions on the scarcity of water and its quality for human consumption are keys for the water resources management. The water released as domestic and industrial sewage in water bodies poses a threat to public health. However, the water quality can be improved by controlling pollution and by improving the techniques of inactivation of microorganisms and degradation of compounds, which consists of destruction of microorganisms and degradation of chemicals. One of the alternative techniques for inactivation and degradation is to employ the phenomenon of cavitation. Cavitation develops shear stress within the fluid and, besides, may involve the release of hydroxyl radicals, which assist the oxidation of the compounds present in the water. The objective of this study was to develop a cavitating jet apparatus to inactivate Escherichia coli, using a new configuration with multiple jets. The new configuration of the equipment was tested and compared with the existing configuration at the Laboratory of Hydraulics and Fluid Mechanics in the search for the optimal efficiency. The results indicated a dependence of inactivation with the pressure of the equipment and the configuration of nozzles. A single orifice nozzle and lower pressures (up to 15.00 MPa) or a system of three-dimensional nozzles and higher pressures (around 30.00 MPa) obtained the best inactivation rates. The energy efficiency of the cavitating jet apparatus in the rate of inactivation was verified. In this case, the best alternatives depend on the time required for inactivation. The cavitating jet apparatus proved to be a viable alternative to the inactivation of Escherichia coli and can be used along with other inactivation techniques
Mestrado
Recursos Hidricos, Energeticos e Ambientais
Mestra em Engenharia Civil