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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
771

Hardware and Software Improvements to a Low-Cost Holographic Video Monitor

Henrie, Andrew August 01 June 2018 (has links)
The "Mark V" Holographic Video Monitor ("HoloMonitor") is a continuation of effort and accomplishments to produce a low-cost device capable of reproducing true full-color horizontal-parallax-only computer-generated holograms at typical video frame-rates. While other devices around the world may have greater capabilities, these devices are currently confined to laboratory settings due to their sheer complexity and expense. The aim of this project is to provide researchers and "tinkerers" with a device capable of recreating holographic effects in full color, respectable resolution, in real time, and at a comparatively low cost. The "Mark V" HoloMonitor is a closer representation of a consumer product than any other device of the MIT/BYU series of HoloMonitors. In this thesis, I discuss the complete design and construction of all of the optic (sans modulator) electronic subsystems that compose this device, along with explaining and providing working code needed to drive it in various modes of operation. The main objective of this thesis is to sufficiently instruct undergraduate and graduate colleagues so that they can replicate and build upon this work.
772

Perspective vol. 6 no. 5 (Sep 1972) / Perspective: Newsletter of the Association for the Advancement of Christian Scholarship

Eells, Robert J., Hollingsworth, Marcia, Wilson, Carol 26 March 2013 (has links)
No description available.
773

Résolution de l'équation de transport de Boltzmann pour les phonons et applications

Hamzeh, Hani 13 December 2012 (has links) (PDF)
Cette thèse est consacrée à l'étude de la dynamique et du transport des phonons via la résolution de l'équation de transport de Boltzmann (ETB) pour les Phonons. Un 'solveur' Monte Carlo dédié à la résolution de l'ETB des phonons dans l'espace réciproque, prenant en compte tous les processus d'interactions Normaux et Umklapp à trois-phonons, est proposé. Une prise en compte rigoureuse des lois de conservation de l'énergie et de la quantité de mouvement est entreprise. Des relations de dispersion réalistes, intégrant tous les modes de polarisations, sont considérées. Le calcul des taux d'interactions à trois-phonons de tous les processus Normaux et Umklapp est effectué en utilisant l'approche théorique due à Ridley qui ne nécessite qu'un unique paramètre semi-ajustable pour chaque mode de polarisation, nommément : le coefficient de couplage anharmonique représenté par les constantes de Grüneisen. Les taux d'interactions ainsi calculés ne servent pas uniquement à la résolution de l'ETB des phonons, mais ont permis aussi une analyse complète des canaux de relaxation des phonons longitudinaux optiques de centre de zone. Cette analyse a montré que le canal de Vallée-Bogani est négligeable dans le GaAs, et que vraisemblablement les temps de vie des phonons LO de centre de zone dans l'InAs et le GaSb rapportés dans la littérature sont fortement sous-estimés. Pour la première fois à notre connaissance, un couplage de deux solveurs Monte Carlo indépendants l'un dédié aux porteurs de charges (Thèse E. Tea) et l'autre dédié aux phonons, est effectué. Cela permet d'étudier l'effet des phonons chauds sur le transport des porteurs de charges. Cette étude a montré que l'approximation de temps de relaxation surestime souvent l'effet bottleneck des phonons. Le 'solveur' Monte Carlo est étendu pour résoudre l'ETB des phonons dans l'espace réel (en plus de l'espace réciproque), cela a permet d'étudier le transport des phonons et ainsi de la chaleur. La théorie généralisée de Ridley est toujours utilisée avec des particules de simulations qui interagissent les unes avec les autres directement. Les règles de conservation de l'énergie et de la quantité de mouvement sont rigoureusement respectées. L'effet des processus Umklapp sur la quantité de mouvement totale des phonons est fidèlement traduit; tout comme l'effet des interactions sur les directions des phonons, grâce à une procédure prenant en compte les directions vectorielles respectives lors d'une interaction, au lieu, de la distribution aléatoire usuellement utilisée. Les résultats préliminaires montrent la limite de l'équation analytique de conduction de la chaleur.
774

Noblesse et pouvoir princier dans la Lorraine ducale (vers 1620-1737)

Motta, Anne 04 December 2012 (has links) (PDF)
Cette thèse porte sur les relations entre la noblesse et le prince dans les duchés de Lorraine au coursd'une période qui s'étend des années 1620 à 1737. Elle les explore dans le cadre d'un renforcement du pouvoirducal et dans une période de transition troublée.Dans cet État souverain des confins, la noblesse représentée par quelques puissantes familles issues del'ancienne chevalerie incarne l'élite sociale, morale, et politique. Étroitement associée aux responsabilités, elleest affectée au premier plan par les ruptures qui scandent le XVIIe siècle : la guerre, l'occupation française etl'exil. Autant d'évènements qui déstabilisent le service princier et éprouvent la fidélité au duc, fondementessentiel des rapports de la noblesse au pouvoir. Cette étude revisite les notions de service, de devoir etd'honneur, constitutives de l'identité nobiliaire.Après plus d'un demi-siècle de désordres, la paix de Ryswick (1697) ramène la stabilité et le princeretrouve ses duchés. Le rétablissement de l'État s'effectue dans une dialectique entre tradition et changement. Lanoblesse qui aspire à retrouver sa place auprès du duc est confrontée à de nouvelles incertitudes qu'elle surmontegrâce à la résurgence de la faveur princière et au prix d'une recomposition de l'ordre.L'équilibre des forces est mis à mal en 1729 avec l'avènement de François III dont le destin se joue pardelàles frontières. Détaché de son territoire patrimonial, le jeune souverain rompt le lien avec la noblesselorraine et met fin à l'impératif absolu du service princier.L'étude des relations entre la noblesse et le duc durant le long XVIIe siècle est une réflexion sur lasociété politique d'un État aux limites sensibles et aléatoires.
775

Biochemical and Spectroscopic Characterization of Tryptophan Oxygenation: Tryptophan 2, 3-Dioxygenase and Maug

Fu, Rong 10 June 2009 (has links)
TDO utilizes b-type heme as a cofactor to activate dioxygen and insert two oxygen atoms into free L-tryptophan. We revealed two unidentified enzymatic activities of ferric TDO from Ralstonia metallidurans, which are peroxide driven oxygenation and catalase-like activity. The stoichiometric titration suggests that two moles of H2O2 were required for the production of one mole of N-formylkynurenine. We have also observed monooxygenated-L-tryptophan. Three enzyme-based intermediates were sequentially detected in the peroxide oxidation of ferric TDO in the absence of L-Trp including compound I-type and compound ES-type Fe-oxo species. The Fe(IV) intermediates had an unusually large quadrupole splitting parameter of 1.76(2) mm/s at pH 7.4. Density functional theory calculations suggest that it results from the hydrogen bonding to the oxo group. We have also demonstrated that the oxidized TDO was activated via a homolytic cleavage of the O-O bond of ferric hydroperoxide intermediate via a substrate dependent process to generate a ferrous TDO. We proposed a peroxide activation mechanism of the oxidized TDO. The TDO has a relatively high redox potential, the protonated state of the proximal histidine upon substrate binding as well as a common feature of the formation of ferric hydroxide species upon substrate or substrate analogues binding. Putting these together, we have proposed a substrate-based activation mechanism of the oxidized TDO. Our work also probed the role of histidine 72 as an acid-base catalyst in the active site. In H72S and H72N mutants, one water molecule plays a similar role as that of His72 in wild type TDO. MauG is a c-type di-heme enzyme which catalyze the biosynthesis of the protein-derived cofactor tryptophan tryptophylquinone. Its natural substrate is a monohydroxylated tryptophan residue present in a 119-kDa precursor protein of methylamine dehydrogenase (MADH). We have trapped a novel bis-Fe(IV) intermediate from MauG, which is remarkably stable. A tryptophanyl radical intermediate of MADH has been trapped after the reaction of the substrate with the bis-Fe(IV) intermediate. Analysis by high-resolution size-exclusion chromatography shows that MauG can tightly bind to the biosynthetic precursor and form a stable complex, but the mature protein substrate does not.
776

Genetic mapping of retinal degenerations in Northern Sweden

Köhn, Linda, January 2009 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2009. / Härtill 4 uppsatser. Även tryckt utgåva.
777

Total St Gall : Medieval Monastery as a Disciplinary Institution

Jezierski, Wojtek January 2010 (has links)
How much was a medieval monastery reminiscent of a modern prison? Or insane asylum? And if it was in the least - what can such a metaphor tell us about power relations structuring the life of medieval monks? The purpose of this compilation thesis (sammanläggningsavhandling) is to render explicit and analyze relations of power and modes of control comprising the social tissue of early medieval Benedictine monasteries. By bringing up the examples of tenth- and eleventh-century monasteries of St Gall, Fulda, and Bury St Edmunds, this thesis seeks to understand what power was in medieval monasteries, how and between whom it was exercised, what and how it affected in terms of collective and individual identity. The thesis consists of three introductory chapters, four previously published empirical articles, and a concluding remarks section. Article 1 investigates the problem of surveillance and patterns of social control dispersed in the monastery of St Gall. Article 2 studies the early and high medieval institutional expectations and means of enforcement of the monk’s role. Article 3 scrutinizes an example of a persecution process and a set of defense measures in the hands of the St Gall community warding off an unwanted visitor. Article 4 examines a number of internal monastic conflicts from several monasteries and strategies, both political and cognitive, guiding them. In investigating these problems, the thesis proceeds in a manner of deliberate anachronism. It asks questions about how human subjectivity was manufactured in early medieval St Gall, what were a medieval monastery’s ‘conditions of possibility’ to operate as a social regime, or oral and literary means of conflict management etc. The crucial modern social theories on which the thesis hinges are: Erving Goffman’s notion of ‘total institution’, and Michel Foucault’s analysis of power, as well as Pierre Bourdieu’s logic of action.
778

Les seus episcopals de Girona i Empúries i les terres del nord-est de Catalunya a les fonts escrites d'època tardoantiga (segles IV-VII)

Amich, Narcís M. 13 June 2002 (has links)
La present tesi pretèn ser,tal com el seu mateix nom indica, un estudi de totes aquelles informacions que ens proporcionen les fonts escrites d'època tardoantiga (segles IV-VII)i que fan referència, directament o indirecta, a les terres del nord-est de Catalunya.Fou aquesta àrea geogràfica la que, d'ençà el segle IX, i un cop superada la invasió sarraïna que suposà, entre altres coses, la definitiva desaparició de la seu episcopal emporitana, acabà per convertir-se en el futur territori del bisbat de Girona, una demarcació que englovava els antics dominis eclesiàstics i territorials de les seus visigòtiques de Gerunda i Impurias. És una realitat que l'estudi de la tardoantiguitat al nord-est de Catalunya ha experimentat un important impuls en els darrers anys. Es en aquest marc, que la investigació que presentem, pretén ser una aportació a una millor comprensió d'aquest període, amb la sistematització i catalogació de tots aquells textos, la cronologia dels quals abraça el període comprés entre els segles IV-VII, on es fa menció expressa a l'àrea geogràfica que ens ocupa.Aquest estudi s'estructura en set parts clarament diferenciades encara que interdependents entre si, cadascuna de les quals amb una especificitat i una metodologia pròpia.A la primera d'elles (caps.2-3), i a mode d'introducció, es fixen els límits territorials (marc geogràfic) i cronològics (marc històric) de la investigació, elements del tot indispensables i necessaris per a comprendre millor l'escenari on tenen lloc els fets descrits.Un segon gran apartat està enterament dedicat a l'estudi i anàlisi de les principals aportacions realitzades per la historiografia del nostre país en els darrers segles, del XVII fins a l'actualitat, en l'estudi del tema que ens ocupa.En tercer lloc, es passa a analitzar individualment totes i cadascuna de les referències textuals recollides en aquest estudi. L'anàlisi l'hem divididida en cin grans apartats, atenent i respectant la diversa tipologia de les fonts consultades: 1) els itineraria romana; 2) els textos de la patrologia tardoantiga; 3) les actes conciliars; 4) els textos litúrgics; i 5) l'epigrafia. L'estudi de cada text es realitza d'una manera global i sitemàtica, analitzant l'autor, el text i l'època de composició, i tot això en el marc més ampli de la societat del seu temps.Un apartat certament important és enterament dedicat a l'estudi dels orígens i difusió del culte al màrtir Feliu de Girona durant l'antiguitat tardana, a partir sobretot de la informació proporcionada per les fonts escrites i epigràfiques de l'època. El culte al màrtir gironí del segle IV fou, sense cap mena de dubtes, un dels elements característics i definidors en la vida de la Gerunda tardoantiga i, al mateix temps, un signe del gran prestigi assolit per la seu episcopal gironina a la resta d'Hispània durant l'antiguitat tardana.Finalment, i després de presentar, a tall de síntesi, les principals conclusions d'aquesta investigació, un darrer gran apartat ve constituït per un apèndix documental, en el qual s'hi recullen, seguint un criteri cronològic, tots els textos estudiats, transcrits segons les principals edicions crítiques citades. Val a dir, que en aquesta investigació hem utilitzat en la majoria dels casos les millors edicions crítiques de cadascuna de les obres estudiades, un fet que ha permès, en ocasions, corregir antigues transcripcions molt menys acurades i crítiques que s'havien inclòs en moltes de les obres dels darrers dos-cents anys on s'estudiava el període històric que ens ocupa. / This doctoral thesis, as its name suggests, tries to be a study of all the information which can be obtained from the written sources in the late antique period (from the fourth to the seventh century) and which directly or indirectly refer to the lands in the northeast of Catalonia. From the ninth century onwards and once its people got over the Saracen invasion which, among other things, led to the end of the episcopal see in Impurias, this geographical area ended up becoming the future territory of the diocese of Girona. This area included the old ecclesiastical and territorial dominions of the visigothic sees of Gerunda and Impurias. It is a fact that the study of late antiquity has shown a major boost in the last years. It is within this framework that we are presenting this study, which tries to contribute to a better understanding of this period, by systematizing and cataloguing all the texts with a chronology between the fourth and seventh century A.D., where the geographical area we are dealing with is specifically mentioned.This study is organized into seven clearly different parts which are nevertheless interdependent, each one with its own specificity and methodology.In the first part (chs.2-3), and by way of introduction, the territorial and chronological boundaries of the study (geographical and historical framework) have been fixed, essential elements to better understand the scene in which the events described take place.There is a second big section which is etirely dedicated to the study and analysis of the main contributions from historiography to the study of the subject we are dealing with in our country in the last centuries, from the seventeenth century until today.Thirdly, there is an individual analysis of ace of the textual references collected in this study. The analysis has been divided into five big sections , following and respecting the diverse tipology of the sources consulted: 1) the itineraria romana; 2) text from the late antique patrology; 3) council minutes; 4) liturgical texts; and 5) epigraphy. Each text is studied globally and systematically by analysing the author, the text and the period of composition, and everything within the wider framework of the society of their time.A really important section is completely dedicated to the study of the origins and spreading of the worship of the martyr of Sant Feliu from Girona during late antiquity, especially from the information obtained from the written and epigraphic sources of that time. The worship of the martyr from Girona of the fourth century was without doubt one ot the characteristic and distinctive elements in the life of the late antique Gerunda and , at the same time, a sign of the great prestige achieved by the episcopal see from Girona to the rest of Hispania during late antiquity.Finally, and after synthetically presenting the main conclusions of this study, there is a final big section with a documentary appendix in which there are all the texts which have been studied, in chronological order, transcribed according to the main critical editions which have been quoted. It must be said that in this study we have mostly used the best critical editions of each of the works studied, which has occasionally allowed us to correct old much less accurate or critical transcriptions which had been included in many of the works of the last two hundred years, where the historical period we are dealing with was studied.
779

Estudo fitoquímico e avaliação das atividades antimicrobiana, de inibição enzimática e antitumoral de Erythrina crista-galli nativa do RS / Phytochemical study and evaluation of antimicrobial, enzymatic inhibition and antitumor activities Erythrina crista-galli native from RS

Ávila, Janaína Medeiros de 05 September 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The phytochemical study of the crude extract hexane, methanol and fractions (acid ether, basic ether and basic acetate) from the stem bark of E. crista-galli (Fabaceae) resulted in the isolation of four compounds: The phytosterol stigmasterol (70), the triterpene lupeol (71) and the alkaloids erysotrine (1) and epierythratidine (50), usual in the genus Erythrina. The structures of the isolated metabolites were elucidated by 1H and 13C NMR uni and bidimensional, and compared with standard sample and data available in the literature. The extracts, fractions and isolated compounds were tested for their antimicrobial and antitumor front cancer cells HT29 (colorectal) activities, as well as regarding the capacity of inhibition of enzymes prolyl oligopeptidase, dipeptidil peptidase-VI and acetylcholinesterase. The crude methanolic extract, all fractions and individual compounds showed high antimicrobial activity mainly against Gram-positive and Gram-negative bacteria. The results were satisfactory in POP inhibition assays, when the crude methanolic extract and its fractions, mainly acid ether fraction, showed great inhibitor potential against this enzyme. For DPP-IV only the crude hexane extract was active. The in vitro antitumoral activity of the crude methanolic extract, basic fractions and the isolate alkaloids was investigated at different concentrations against the human colon cancer cell line HT-29 (PicoGreen dsDNA assay). The results suggest that the anti-proliferative effect of E. crista-galli extract on HT-29 cancer cells may be attributed, at least in part, to the presence of the erythrinian alkaloids 1 and 50. / O estudo fitoquímico do extrato bruto hexânico, metanólico e frações (éter ácida, éter básica e acetato básica) das cascas do caule de E. crista-galli (Fabaceae) resultou no isolamento de quatro compostos: o fitoesterol estigmasterol (70) e o triterpeno lupeol (71) além dos alcaloides erisotrina (1) e epieritratidina (50) usuais do gênero Erythrina. As estruturas dos metabólitos isolados foram elucidadas através de RMN 1H e 13C, uni e bidimensionais, além de comparação com amostra padrão quando existente e dados disponíveis na literatura. Os extratos, as frações e os compostos isolados foram testados quanto à sua atividade antimicrobiana, antitumoral frente a células cancerígenas HT29 (colorretal) e de inibição das enzimas POP, DPP-IV e AChE. Dentre as amostras testadas, o extrato bruto metanólico (EBM), suas frações (FEA, FEB e FAB) e compostos isolados apresentaram grande potencial antimicrobiano principalmente frente as bactérias Gram-positivas e Gram-negativas. Os resultados obtidos nos ensaios enzimáticos foram satisfatórios para a enzima POP, onde o EBM e suas frações, principalmente a fração éterea ácida (FEA), demonstraram grande potencial inibidor desta enzima. Para a DPP-IV apenas o extrato bruto hexânico (EBH) mostrou-se ativo. O efeito antitumoral da planta em questão também foi investigado e os resultados obtidos indicam que o EBM, a combinação das frações FEB e FAB e o alcaloide epieritratidina (50) possuem um grande efeito antiproliferativo frente às células do colorretal (HT29) após 72 horas de exposição.
780

Réalisation de sources laser III-V sur silicium

Dupont, Tiphaine 19 January 2011 (has links)
Le substrat SOI (Silicon-On-Insulator) constitue aujourd’hui le support de choix pour la fabrication de fonctions optiques compactes. Cette plateforme commune avec la micro-électronique favorise l’intégration de circuits photoniques avec des circuits CMOS. Néanmoins, si le silicium peut être utilisé de manière très avantageuse pour la fabrication de composants optiques passifs, il présente l’inconvénient d’être un très mauvais émetteur de lumière. Ceci constitue un obstacle majeur au développement de sources d’émission laser, briques de constructions indispensables à la fabrication d’un circuit photonique. La solution exploitée dans le cadre de cette thèse consiste à reporter sur SOI des épitaxies laser III-V par collage direct SiO2-SiO2. L’objectif est de réaliser sur SOI des sources lasers à cavité horizontale permettant d’injecter au moins 1mW de puissance dans un guide d’onde silicium inclus dans le SOI. Notre démarche est de transférer un maximum des fonctions du laser vers le silicium, dont les procédés sont familiers au monde de la micro-électronique. Dans l’idéal, le III-V ne devrait être utilisé que comme matériau à gain ; la cavité laser pouvant être fabriquée dans le silicium. Mais cette ligne de conduite n’est pas forcément aisée à mettre en œuvre. En effet, les photons sont produits dans le III-V mais doivent être injectés dans un guide silicium placé sous l’épitaxie. La difficulté est que les deux matériaux sont séparés par plus d’une centaine de nanomètres d’oxyde de collage faisant obstacle au transfert de photons. Le développement de lasers III-V couplés à un guide d’onde SOI demande alors de nouvelles conceptions du système laser dans son ensemble. Notre travail a donc consisté à concevoir un laser hybride III-IV / silicium se pliant aux contraintes technologiques du collage. En s’appuyant sur la théorie des modes couplés et les concepts des cristaux photoniques, nous avons imaginé, réalisé, puis caractérisé un laser à contre-réaction distribuée hybride (en anglais : « distributed feedback laser », laser DFB). Son fonctionnement optique original, permet à la fois un maximum de gain et d’efficacité de couplage grâce à une circulation en boucle des photons du guide III-V au guide SOI. Sur ces dispositifs, nous montrons une émission laser monomode (SMSR de 35 dB) à température ambiante en pompage optique et électrique pulsé. Comme attendu, la longueur d’onde d’émission est dépendante du pas de réseau DFB. Les lasers fonctionnent avec une épaisseur de collage de silice de 200 nm, ce qui offre une grande souplesse quant au procédé d’intégration. Tous les lasers fonctionnent jusqu’à des longueurs de 150 μm (la plus petite longueur prévue sur le masque). Malgré les faibles niveaux de puissances récoltés dans la fibre lors des caractérisations, la prise en compte des pertes optiques induites pas les coupleurs fibres nous indique que la puissance réellement injectée dans le guide silicium dépasse le milliwatt. Notre objectif de ce point de vue est donc rempli. Malheureusement le fonctionnement des lasers en injection électrique continue n’a pas pu être obtenu dans les délais impartis. Cependant, les faibles densités de courant de seuil mesurées en injection pulsée (300A / cm2 à température ambiante sur les lasers de 550 μm de long) laissent présager un fonctionnement prochain en courant continu. / Silicon-On-Insulator (SOI) is today the utmost platform for the fabrication of compact optical functions. This common platform with microelectronics favors the integration of photonic circuits with CMOS circuits. Nevertheless, if silicon allows for the fabrication of compact passive photonic functions, its poor light emission properties constitute a major obstacle to the development of an integrated laser source. The solution used within the framework of this thesis consists in integrating III-IV laser stacks on 200 mm SOI wafers by the mean of SiO2-SiO2 direct bonding. The aim of this work is to demonstrate a III-V on SOI laser that couples at least 1mW to a silicon waveguide. Our approach is to transfer a maximum of the laser complexity to the silicon, which processes are familiar to microelectronics. Ideally, III-V should be just used as a gain material ; the laser cavity being made out of silicon. However, this approach is not so easy to put into practice. Indeed, photons are generated by the III-V waveguide but have to be transferred into the silicon waveguide located under the stack. The difficulty is that both waveguides are separated by a low index bonding layer, which thickness ranges from one hundred to several hundreds of nanometres. The development of a III-V on SOI laser then requires a new thinking of the whole laser system. Therefore, our work has consisted in designing a III-V on silicon hybrid laser that takes into consideration the specific constraints of the integration technology. Based on the coupled mode theory and on the photonic crystals concepts, we have designed, fabricated and characterized an hybrid Distributed Feedback Laser (DFB). Its original work principle allows for both a high amount of gain and coupling efficiency, thanks to a continuous circulation of photons from the III-V to the SOI waveguide. On these devices, we show a monomode laser emission at room temperature (with a side mode suppression ratio of 35dB) under pulsed optical and electrical pumping. As expected, the lasing wavelength is function of the DFB grating pitch. The lasers work with a bonding layer as thick as 200nm, that greatly relaxes the constraints of the bonding technology. Lasers work down to a minimum length of 150 μm, which is the shortest laser lenght of the mask. Despite the low power levels collected by the fibre during the characterizations, accounting for the high optical losses due to the fiber couplers, the optical power effectively injected to the silicon waveguide should be in the miliwatt range. Unfortunately, the low threshold current densities measured under pulsed operation (300 A / cm2 at room temperature) suggest that the continuous-wave regime should be reached in a very near future.

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