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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.
11

Presença de alcalóides pirrolizidinicos em Ageratum conyzoides L., Asteraceae

Bosi, Cristiane Fracari 04 March 2013 (has links)
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-graduação em Farmácia / Made available in DSpace on 2013-03-04T18:57:56Z (GMT). No. of bitstreams: 1 309329.pdf: 2185130 bytes, checksum: 9e7fefebd24269b86d610ab79db23dda (MD5) / Ageratum conyzoides L. é conhecida popularmente como "mentrasto" e pertence à família Asteraceae. Frequentemente é utilizada como analgésica, tendo sido recentemente incluída na RDC 10 da ANVISA, a qual autoriza sua comercialização na forma de droga vegetal utilizada em infusão para tratar dores articulares e reumatismo. Estudos publicados até o momento não estabelecem a presença de alcaloides pirrolizidínicos na infusão das partes aéreas de A. conyzoides. Considerando a demanda de uso popular desta espécie em tratamentos prolongados, justifica-se a importância de pesquisar a presença destes alcaloides. Para tanto, estudou-se as infusões das partes aéreas de A. conyzoides coletadas em Florianópolis, Santa Catarina e da droga vegetal adquirida em uma farmácia. Também foram estudadas as macerações das partes aéreas de A. conyzoides com os solventes n-hexano, diclorometano, acetato de etila e etanol. As macerações foram fracionadas através de cromatografia e analisadas por RMN de 1H e de 13C. Foram identificadas 13 substâncias pertencentes às classes dos cromenos, flavonoides, cumarinas, lignanas e esteroides. As infusões das partes aéreas de A. conyzoides foram analisadas por EM e RMN de 1H, sendo observada a presença de licopsamina e da sua forma N-óxido / Hedyosmum brasiliense is an aromatic shrub that belongs to the Chloranthaceae family and is popularly used as a calmative and ntiinflammatory, for treating athlete's foot, migraines and diseases of the ovary. This work was done to continue the phytochemical analysis of this species which is popularly known as "Cidrão". It was possible to isolate and identify thirteen substances which were obtained from the hexane and dichloromethane fractions of the ethanol extract. Out of these substances, four are new and belong to the class of sesquiterpene lactones: 15-acetyl-isogermafurenolide (H622), 1-hydroxy-10 ,15-methylenepodoandin (HB 212), 15-hydroxy-isogermafurenolide (HB21) and brasiliensolide (HL 33) which is a dimeric sesquiterpene lactone. Six are being described for the first time for this species (stearic acid monoglyceride, linolenic acid ethyl ester, linoleic acid ethyl ester, 3-methoxy-4- hydroxybenzoic acid, scopoletin and vanillin), and three (podoandin, 13-hydroxy-8,9-dehydroshizukanolide (13HDS) and ß-sitosterol) were previously described for H. brasiliense. With regards to pharmacological studies, podoandin exhibited antidepressant activity by acting on adrenergic, dopaminergic and serotonergic pathways; the crude extract and the lactones podoandin and 13HDS exhibited vasodilator activity and the sesquiterpene lactones (H622, HB 212 and HB 21) showed no antimicrobial activity against Mycobacterium tuberculosis. The substances were identified by Nuclear magnetic resonance spectroscopy 1D, 2D, mass spectrometry and already published data.
12

PREPARACIÓN DE ZEOLITAS DE PORO PEQUEÑO CON CONTROL DE SUS PROPIEDADES FÍSICO-QUÍMICAS PARA SU APLICACIÓN EN CATÁLISIS

Martín García, Nuria 15 January 2018 (has links)
La presente tesis doctoral se centra en la preparación de zeolitas de poro pequeño (3.5-4 Å), en concreto, aquellas cuya estructura presenta además cavidades grandes. Este tipo de materiales ha despertado un enorme interés en los últimos años debido al potencial que presentan como catalizadores en procesos de relevancia industrial y medioambiental, tales como el proceso de transformación de metanol a olefinas (MTO) o la reducción catalítica selectiva (RCS) de NOx. Por ello, existe un interés creciente en la preparación de nuevas estructuras de poro pequeño y en la mejora de las propiedades físico-químicas o de los métodos de preparación de las zeolitas ya existentes. Esto se debe, a que en ocasiones, la aplicación industrial de estas zeolitas se ve limitada, tanto por las condiciones de síntesis, como por el coste del agente director de estructura orgánico (ADEO) empleado en la preparación. En este sentido, el desarrollo de nuevas estrategias de síntesis podría dar lugar a la obtención de algunas estructuras de poro pequeño con propiedades físico-químicas mejoradas (relación Si/Al, acidez, tamaño de cristal, entre otras), así como a una reducción en los costes de preparación eliminando el uso de ADEOs o sustituyéndolos por moléculas de menor coste. Todo ello favorecería la posible aplicación industrial de dichas zeolitas de poro pequeño. La primera parte de la tesis se centra en la optimización del proceso de síntesis de dos estructuras zeolíticas de poro pequeño, CHA y AEI, con elevado contenido en sílice y buenos rendimientos de síntesis. Para ello, se desarrolla una nueva metodología de síntesis que combina el uso de agentes directores de estructura orgánicos con el uso de una zeolita cristalina como única fuente de Si y Al. Mediante dicho procedimiento se obtienen ambas zeolitas con unas propiedades físico-químicas (tamaño de cristal y acidez) óptimas para su empleo como catalizadores del proceso MTO. En la segunda parte de la tesis se preparan diferentes zeolitas de poro pequeño (CHA, AEI, AFX y ERI) que contienen cobre o hierro como centros activos aislados. Para la introducción de especies metálicas en su interior, se emplean tanto métodos convencionales de intercambio iónico como métodos de síntesis directa, que eliminan la necesidad de tratamientos post-síntesis, además de permitir obtener una dispersión más homogénea en los cristales de la zeolita. La actividad catalítica y estabilidad hidrotermal de estas zeolitas, se evalúa para la RCS de NOx. / The present doctoral thesis focuses on the preparation of small-pore zeolites (3.5-4 Å), preferentially those also containing large cavities. This type of materials has attracted great technological interest during the last years due to their recent commercial application as catalysts in relevant industrial and environmental processes, such as the transformation of methanol into light olefins (MTO), or the selective catalytic reduction (RSC) of NOx. Therefore, there is an increasing interest in the preparation of new small pore structures and/or the improvement of the physico-chemical properties or the synthesis protocols of the zeolites currently in use. In fact, the industrial application of a particular zeolite could be limited by the high costs associated to its preparation, and in particular, to the high costs associated to the organic structure directing agent (OSDA) employed. In this sense, the discovery and development of new synthetic strategies could not only favor the crystallization of novel small-pore zeolites with improved physico-chemical properties (i.e. Si/Al ratio, crystal size, among others), but also optimizing the production costs, avoiding the use of expensive OSDAs or, at least, substituting those by less-expensive organic molecules. These features could encourage the potential commercialization of such novel small pore zeolites as competitive catalysts for relevant industrial processes. In the first part of this thesis, the synthesis protocols of two different high-silica small pore zeolites, CHA and AEI, have been intensively evaluated in order to develop a new procedure to direct the crystallization of these two zeolites with excellent solid yields. It has been found that the combination of a particular OSDA with a crystalline zeolite as the sole Si and Al sources, as FAU, allows the obtention of both zeolites with optimal physico-chemical properties (crystal size and acidity) for its application as efficient catalysts for the MTO process. In the second part of this thesis, different small-pore zeolites (CHA, AEI, AFX y ERI) containing copper or iron as isolated active catalytic sites, have been prepared. To introduce these metallic species within the zeolite crystals, either conventional ion-exchange methods or direct 'one-pot' synthetic methods have been employed. Interestingly, the use of 'one-pot' synthesis methods not only eliminates the need for post-synthetic ion-exchange treatments, but also allows obtaining better metal dispersions along the zeolite crystals. The catalytic activity and hydrothermal stability of such zeolites has been evaluated for the SCR of NOx. / Aquesta tesi doctoral es centra en la preparació de zeolites de por menut (3.5-4 Å), i en particular, aquelles amb una estructura que presenta, a més, grans cavitats. Aquest tipus de materials han despertat un gran interès als últims anys, degut al potencial que presenten com a catalitzadors eficients en processos rellevants per la indústria i el medi ambient, com son el processos de transformació de metanol a olefines (MTO) o la reducció catalítica selectiva (RCS) de NOx. Per aquest motiu, existeix un interès creixent tant en la preparació de noves estructures de por menut, com en la millora de les propietats fisico-químiques o dels mètodes de preparació de les zeolites ja existents. Aquest motiu es deu a que en ocasions, l'aplicació industrial d'aquestes zeolites, es pot veure limitada per els costs associats a la seua preparació, en particular de l'agent director d'estructura orgànic (ADEO) emprat. En aquest sentit, el desenvolupament de noves estratègies de síntesi podria donar lloc a l'obtenció d'algunes estructures de por menut amb propietats físico-químiques millorades (relació Si/Al, acidesa, tamany de cristall, entre altres), així com a una reducció dels costos de preparació, eliminant l'ús de ADEOs o substituint-los per molècules de menor cost. Tot això, podria afavorir la possible aplicació industrial d'aquestes noves zeolites de por menut. La primera part de la tesi es centra en l'optimització del procés de síntesi de dos estructures zeolítiques de por menut, CHA i AEI, amb un elevat contingut de sílice i amb bons rendiments de síntesi. Per això, s'ha desenvolupat una nova metodologia de síntesi que combina l'ús d'agents directors d'estructura orgànics (ADEO) amb una zeolita cristal¿lina com a única font de Si i Al. Mitjançant aquest procediment, s'han pogut obtenir els dos materials amb unes propietats físico-químiques (tamany de cristall i acidesa) òptimes per al seu ús com a catalitzadors en el procés MTO. En la segona part de la tesi s'han preparat diverses zeolites de por menut (CHA, AEI, AFX I ERI), amb àtoms de coure o ferro com a centres catalítics aïllats. Per a la introducció de les espècies metàl¿liques al seu interior, s'han utilitzat tant mètodes convencionals d'intercanvi iònic com mètodes de síntesi directa. En particular, els mètodes directes eliminen la necessitat de introduir diferents tractament post-síntesi, a més de permetre una dispersió més homogènia del metall als cristalls de la zeolita. L'activitat catalítica i l'estabilitat hidrotermal d'aquestes zeolites s'ha avaluat per a la RCS de NOx. / Martín García, N. (2017). PREPARACIÓN DE ZEOLITAS DE PORO PEQUEÑO CON CONTROL DE SUS PROPIEDADES FÍSICO-QUÍMICAS PARA SU APLICACIÓN EN CATÁLISIS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/94628 / TESIS
13

Em qualquer ch?o: sempre ga?cho! A multiterritorialidade do migrante ga?cho no Mato Grosso / In any ground: always ga?cho! The multiterritoriality of the ga?cho migrant in Mato Grosso

Rocha, Betty Nogueira 10 March 2006 (has links)
Made available in DSpace on 2016-04-28T20:12:49Z (GMT). No. of bitstreams: 1 2006-Betty Nogueira Rocha.pdf: 5580202 bytes, checksum: 27b02d9d47d691fadb95c54d721b87e2 (MD5) Previous issue date: 2006-03-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The effort undertaken in this research was to investigate how the process of installation of the gaucho migrant in the north of Mato Grosso State happens. The basis of the analysis is the (re)construction of the ga?cha identity informed by the self-image of this social group which sees itself as an explorer, a pioneer and an enterprising that, leaving its origin territory, takes with it, in its baggage, a set of socio-cultural representations and references which are recovered in the new territory as a characteristic mark of its territoriality. It is about a case study from the life history and the ga?chos migrants memory who left the south region of the country going to a place which nowadays is the seat of the district of Lucas do Rio Verde. The research points to an analysis which has as reference the notion of symbolic power in which the group social identity interferes and is decisive in the constitution of new territories. It is through a symbolic array, using spacial elements, representations or symbols, that the gaucho constitutes his territorial identity, that is, he gives or reveals an aspect which homogenizes the territory where he lives, even if far from his homeland, able to give the group a certain cohesion and power (symbolic). In this way, a constitution process of a territory involves, dialectically, an indissoluble movement of unisntallation and reinstallation which happens in different scales and can be better understood from the concept of multiterritoriality. This dissertation has the aim of understanding the customs (social and cultural) and representations which were selected by this social actor, the gaucho , to print his identity in this new territory and to demonstrate that there is an interdependency which cannot be ignored among the socio-cultural relationships of the migrants and the standard of appropriation and territorial organization in different scales. / O esfor?o empreendido nesta pesquisa foi o de investigar como se d? o processo de territorializa??o do migrante ga?cho no norte do estado de Mato Grosso. O fio condutor desta an?lise ? a (re)constru??o da identidade ga?cha informada pela auto-imagem deste grupo social que se v? como desbravador, pioneiro e empreendedor que, ao deixar seu territ?rio de origem, carrega consigo, em sua bagagem, todo um cabedal de representa??es e referenciais s?cio-culturais que s?o acionados no territ?rio de ado??o como marca distintiva de sua territorialidade. Trata-se de um estudo de caso a partir da hist?ria de vida e da mem?ria dos migrantes ga?chos que sa?ram da regi?o sul do pa?s tendo como ponto de atra??o o lugar que hoje ? sede do munic?pio de Lucas do Rio Verde. O caminho investigativo aponta para um eixo anal?tico que tem por referencial a no??o de poder simb?lico, onde a identidade social do grupo interfere e ? decisiva na constitui??o de novos territ?rios. ? atrav?s de todo um aparato simb?lico utilizando-se de elementos espaciais, representa??es ou s?mbolos que o ga?cho constitui a sua identidade territorial, ou seja, d? ou revela um aspecto homogeneizador ao territ?rio em que vive, mesmo que distante de sua terra natal, capaz de conferir ao grupo uma determinada coes?o e for?a (simb?lica). Neste sentido, um processo de constitui??o de um territ?rio envolve, dialeticamente, um movimento indissoci?vel de desterritorializa??o e de re-territoriliza??o que ocorre em escalas distintas e pode ser melhor compreendido a partir do conceito de multiterritorialidade. Esta incurs?o investigativa tem por objetivo compreender as pr?ticas (sociais e culturais) e representa??es que foram selecionadas por este ator social, o ga?cho , para imprimir a sua identidade neste novo territ?rio e demonstrar que h? uma interdepend?ncia, que n?o pode ser ignorada, entre as rela??es s?cioculturais dos migrantes e o padr?o de apropria??o e organiza??o territorial em diferentes escalas.
14

Urban design control in Hong Kong with particular reference to the design quality of built form

黎少鳳, Lai, Siu-fung, Esther. January 2000 (has links)
published_or_final_version / Urban Design / Master / Master of Urban Design
15

Rehabilitation centre at Cha Ko Ling

苗華培, Miu, Wah-pui, Edward. January 1996 (has links)
published_or_final_version / Architecture / Master / Master of Architecture
16

Étude expérimentale et simulation de procédés hybrides intégrant des membranes zéolites et polymères pour la purification d’hydrocarbures gazeux biosourcés par perméation de vapeurs / Experimental study and simulation of hybrid processes integrating zeolite and polymer membranes for the purification of bio-based gaseous hydrocarbons by vapor permeation

Picaud Vannereux, Simon 25 April 2019 (has links)
Ces travaux ont porté sur l’intérêt de l’utilisation d’une membrane composite zéolite (CHA SSZ-13) accessible à l’échelle commerciale au travers de la technologie membranaire de perméation de gaz et de vapeurs. L’applicabilité de cette technologie séparative s’est principalement focalisée sur la récupération du méthane, propane et d’isobutène issus de flux produits à des échelles industrielles par des procédés durables. La mise au point d’un banc expérimental pour la mesure de données de perméation de gaz et de vapeur a été réalisé. En se basant sur des mesures expérimentales de perméation menées avec la membrane zéolite de l’étude, un premier cas d’application pratique a été de simuler les performances séparatives d’un procédé hybride associant un module membranaire zéolite avec une condensation cryogénique à partir d’un cahier des charges industriel pour la récupération d’isobutène. Le procédé hybride étudié est toujours plus performant que le procédé de condensation cryogénique seul de référence en termes de pureté du produit condensé obtenu et de consommation énergétique. Des cartographies ont été dressées afin de situer les performances de séparation simulées en fonction de l’objectif de récupération d’isobutène souhaité. Un second cas théorique de récupération du propane à partir d’évents de purge à l’azote avec un procédé hybride de séparation cryogénique couplée à une membrane permsélective a été étudié. Une cartographie des performances de séparation membranaire relative au couple propane/diazote selon les données de la littérature ouverte actuelles a été présentée. La membrane la plus permsélective au diazote et au propane (respectivement CHA SSZ-13 et PEBAX 2533) a été sélectionné afin de simuler des procédés hybrides dont les performances séparatives ont été comparées à celles de la condensation cryogénique seule de référence. Pour de faibles teneurs en propane, il a été constaté que le procédé le plus performant (besoin énergétique et qualité du produit condensé) impliquait un module membranaire polymère de type PEBAX 2533 avec un système de mise sous vide du perméat. / This work focused on the interest of using a zeolite composite membrane (CHA SSZ-13) accessible on a commercial scale through the membrane technology of gas and vapor permeation. The applicability of this separation technology has mainly focused on the recovery of methane, propane and isobutene from fluxes produced at industrial scales by sustainable processes. The development of an experimental lab scale pilot for gas and vapor permeation data measurements is detailed. Based on experimental permeation measurements carried out with the zeolite membrane of the study, a first case of practical application was to simulate the separation performance of a hybrid process associating a zeolite membrane module with a cryogenic condensation from an industrial specification for the recovery of isobutene. The hybrid process studied is always more efficient than the only cryogenic condensation process taken as reference in terms of purity of the condensed product obtained and energy consumption. A chart was generated to locate the simulated separation performance based on the desired isobutene recovery objective. A second theoretical case of propane recovery from nitrogen purging vents with hybrid membrane cryogenic separation process was studied. This study presented a chart of the membrane separation performance of propane over nitrogen according to data from the open literature. The most nitrogen- and propane-selective membrane (CHA SSZ-13 and PEBAX 2533 respectively) was then selected and used in order to simulate hybrid processes where separation performances were compared to a baseline cryogenic standalone process. For low propane contents in the nitrogen feed mixture, it was found that the most efficient process (energy need and quality of the condensed product) involved a PEBAX 2533 polymer membrane module with a vacuum system for the permeate.
17

An horticultural nursery + a Green HK promotion centre

Cheung, Kim-chung, Terence., 張儉中. January 1997 (has links)
published_or_final_version / Architecture / Master / Master of Architecture
18

Pelo escuro: a poesia afro-brasileira de Oliveira Silveira

Boeira, Eloisa Elena Prates 10 January 2014 (has links)
Made available in DSpace on 2014-12-17T15:07:12Z (GMT). No. of bitstreams: 1 EloisaEPB_DISSERT.pdf: 8249895 bytes, checksum: 714a48934f6b9ba968fdf8d2c9fe2504 (MD5) Previous issue date: 2014-01-10 / O presente estudo traz uma reflex?o sobre os discursos culturais afro-brasileiros e o lugar ocupado pela poesia em meio a uma sociedade racista. A pesquisa tem como prop?sito fazer um estudo da poesia de Oliveira Silveira (1968, 1970, 1977, 1981, 1987). Leva-se em considera??o a rela??o da produ??o po?tica de Oliveira com as propostas do movimento da Negritude e o di?logo l?cido que o mesmo estabelece com poetas vinculados ao referido movimento e como Silveira sugere dentro da literatura a negritude como uma forma de intersec??o na poesia brasileira. A proposta aqui apresentada observa tamb?m o hibridismo na po?tica de Oliveira Silveira ao se enfatizar um olhar sobre uma escrita comovida pelo tra?o do entre-lugar do discurso. Analisa-se a caracteriza??o de uma literatura gerada pelo tom de den?ncia ao desconstruir historicamente o que h? muito tempo se estabelece como democracia racial . Em cumplicidade com a poesia regional do Rio Grande do Sul, a poesia de Oliveira vem permeada pela diversidade de ritmos que traduzem o legado da cultura negra mundo afora. Essa pesquisa sustenta-se nos estudos de Eduardo de Assis Duarte (2005, 2011) e Kabengel? Munanga (2008, 2009) sobre Negritude e Identidade na literatura afro-brasileira, que se caracteriza como um movimento de consci?ncia pela reconstru??o ou mesmo revis?o hist?rica do que foi apagado no calabou?o dos navios negreiros. As leituras de Eduardo de Assis Duarte fomentam novos questionamentos, p?em em d?vida a exist?ncia de uma identidade essencialista. Aponta-se nessa travessia para uma pluralidade de identidades, constru?das por in?meros grupos culturais na encruzilhada dos diversos momentos hist?ricos. Analisam-se, portanto, a partir da cr?tica que Stuart Hall (2011) faz ao considerar as ideias de di?sporas, as fronteiras das margens no universo da p?s-coloniza??o. Por fim, h? uma encruzilhada ao se pensar a partir de Kabengel? Munanga, o discurso da negritude e da identidade negra nas rela??es sociais e culturais afrodescendentes
19

Imaging protoplanets: observing transition disks with non-redundant masking

Sallum, Steph, Eisner, Josh, Close, Laird M., Hinz, Philip M., Follette, Katherine B., Kratter, Kaitlin, Skemer, Andrew J., Bailey, Vanessa P., Briguglio, Runa, Defrere, Denis, Macintosh, Bruce A., Males, Jared R., Morzinski, Katie M., Puglisi, Alfio T., Rodigas, Timothy J., Spalding, Eckhart, Tuthill, Peter G., Vaz, Amali, Weinberger, Alycia, Xomperio, Marco 04 August 2016 (has links)
Transition disks, protoplanetary disks with inner clearings, are promising objects in which to directly image forming planets. The high contrast imaging technique of non-redundant masking is well posed to detect planetary mass companions at several to tens of AU in nearby transition disks. We present non-redundant masking observations of the T Cha and LkCa 15 transition disks, both of which host posited sub-stellar mass companions. However, due to a loss of information intrinsic to the technique, observations of extended sources (e.g. scattered light from disks) can be misinterpreted as moving companions. We discuss tests to distinguish between these two scenarios, with applications to the T Cha and LkCa 15 observations. We argue that a static, forward-scattering disk can explain the T Cha data, while LkCa 15 is best explained by multiple orbiting companions.
20

Esthétique et symbolique du rituel de thé ± wabi cha ℓ

Grondin, Myriam January 2006 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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