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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.
1

A web of contradiction : an assessment of the migration-development nexus and its relevance to MIDA

Hodiwala, Naozad Oorvax 05 1900 (has links)
Although organizations and researchers have long pointed to the impact of migration on the development of countries of origin, one can hardly deny the bright spotlight and the rapid resurgence within policy debates, that the migration-development nexus enjoys over recent years. European politicians, inter-governmental organizations and academics alike un-equivocally point out that migration if managed appropriately, could bring the proverbial ‘win-win-win’ result for migrants themselves, sending, and receiving countries. So much so that, circular migration is being advocated as the solution to the migration challenges facing the European Union (EU) today. However, at a closer look, the evidence found is contradictory at best and largely depends on how development is defined and the breadth with which remittances are measured. Thus, this paper seeks for greater knowledge of this contemporary movement of persons, without which the EU will continue to develop policies and recommendations that may sat-isfy their member states, but not their intended audience. Starting with the Gastarbeiter programmes of the 1960-70s and concluding with the recent EU Blue Card initiative, this paper will conclude that the overall contribution of migrants to development is dependent on a scheme’s ability to a) encourage ‘return of innovation’ and b) broaden its outlook on non-financial remittances. Using the International Organization for Migration’s (IOM) Migration for Development in Africa (MIDA) Italy-Ghana/Senegal programme, and based on Ionescu’s four point criteria for successful circular migration policy, this paper will evaluate the MIDA Italy framework and suggest means by which its successes could be magnified.
2

A web of contradiction : an assessment of the migration-development nexus and its relevance to MIDA

Hodiwala, Naozad Oorvax 05 1900 (has links)
Although organizations and researchers have long pointed to the impact of migration on the development of countries of origin, one can hardly deny the bright spotlight and the rapid resurgence within policy debates, that the migration-development nexus enjoys over recent years. European politicians, inter-governmental organizations and academics alike un-equivocally point out that migration if managed appropriately, could bring the proverbial ‘win-win-win’ result for migrants themselves, sending, and receiving countries. So much so that, circular migration is being advocated as the solution to the migration challenges facing the European Union (EU) today. However, at a closer look, the evidence found is contradictory at best and largely depends on how development is defined and the breadth with which remittances are measured. Thus, this paper seeks for greater knowledge of this contemporary movement of persons, without which the EU will continue to develop policies and recommendations that may sat-isfy their member states, but not their intended audience. Starting with the Gastarbeiter programmes of the 1960-70s and concluding with the recent EU Blue Card initiative, this paper will conclude that the overall contribution of migrants to development is dependent on a scheme’s ability to a) encourage ‘return of innovation’ and b) broaden its outlook on non-financial remittances. Using the International Organization for Migration’s (IOM) Migration for Development in Africa (MIDA) Italy-Ghana/Senegal programme, and based on Ionescu’s four point criteria for successful circular migration policy, this paper will evaluate the MIDA Italy framework and suggest means by which its successes could be magnified.
3

A web of contradiction : an assessment of the migration-development nexus and its relevance to MIDA

Hodiwala, Naozad Oorvax 05 1900 (has links)
Although organizations and researchers have long pointed to the impact of migration on the development of countries of origin, one can hardly deny the bright spotlight and the rapid resurgence within policy debates, that the migration-development nexus enjoys over recent years. European politicians, inter-governmental organizations and academics alike un-equivocally point out that migration if managed appropriately, could bring the proverbial ‘win-win-win’ result for migrants themselves, sending, and receiving countries. So much so that, circular migration is being advocated as the solution to the migration challenges facing the European Union (EU) today. However, at a closer look, the evidence found is contradictory at best and largely depends on how development is defined and the breadth with which remittances are measured. Thus, this paper seeks for greater knowledge of this contemporary movement of persons, without which the EU will continue to develop policies and recommendations that may sat-isfy their member states, but not their intended audience. Starting with the Gastarbeiter programmes of the 1960-70s and concluding with the recent EU Blue Card initiative, this paper will conclude that the overall contribution of migrants to development is dependent on a scheme’s ability to a) encourage ‘return of innovation’ and b) broaden its outlook on non-financial remittances. Using the International Organization for Migration’s (IOM) Migration for Development in Africa (MIDA) Italy-Ghana/Senegal programme, and based on Ionescu’s four point criteria for successful circular migration policy, this paper will evaluate the MIDA Italy framework and suggest means by which its successes could be magnified. / Arts, Faculty of / Central Eastern Northern European Studies, Department of / Graduate
4

Low cost, more efficient, and less toxic synthetic routes to conjugated polymers

Ayuso Carrillo, Josue January 2016 (has links)
As key components of flexible organic electronics, the synthesis of polythiophenes via less toxic and more cost-effective routes is demanded. An efficient synthetic route for the production of thienyl-containing homopolymers and copolymers has been developed. The synthetic approach consists of: i) the synthesis in high yield and high purity of thienyl borane monomers protected with N-methyliminodiacetic acid (MIDA) via C-H electrophilic borylation. This reaction uses a combination of inexpensive reagents BCl3, AlCl3, and 2,6-dichloropyridine (Cl2Py) for the regioselective electrophilic aromatic substitution of thiophenes, followed by addition of a second aprotic amine pre-esterification to reduce the Brønsted acidity of the reaction mixture. In situ esterification provided the desired thienyl MIDA boronateester monomers in one-pot at room temperature. ii) Subsequent Suzuki-Miyaura polymerisation of the synthesised monomers to produce well defined thienyl containing pie-conjugated polymers in high molecular weight and high yields. Key reaction parameters for successful Suzuki-Miyaura polymerisation of thienyl-derived MIDA boronate esters under mild temperatures (i.e., 55 °C in THF) were found: a) an optimal monomer:H2O:base ratio, which enables controlled hydrolysis of the BMIDA moiety into its corresponding boronic acid at appropriate rates for high fidelity polymerisation. b) Nature of the base, where K3PO4 provided the best results for production of homopolymers (e.g., rr-P3HT), or KOH which gave excellent results for the formation of copolymers across a range of electronically different comonomers (e.g., pCPDT-BT). Thus, it is demonstrated that the approach is a general strategy for the highly efficient production of thienyl containing pie-conjugated regioregular, regiosymmetric and Donor-Acceptor polymers.
5

Precondicionamiento isquémico es una estrategia quirúrgica útil en el trasplante hepático con injerto de tamaño reducido, El

Franco Gou, Rosa 03 March 2006 (has links)
El trasplante hepático es la solución para personas que sufren enfermedades hepática terminales o insuficiencia hepática aguda. La principal limitación para la aplicación del trasplante es la falta de órganos respecto a la demanda. El trasplante hepático con injerto de tamaño reducido se desarrolló para aumentar el número de órganos disponibles y así disminuir la lista de espera. Además del síndrome de isquemia/reperfusión (I/R) asociado al proceso de trasplante, es necesario un proceso de regeneración para la viabilidad del injerto. El síndrome de I/R también tiene efectos sistémicos nocivos en el pulmón. El precondicionamiento isquémico (PC) es una estrategia quirúrgica útil frente a la lesión por I/R en modelos de I/R normotérmica y trasplante hepático con 8 y 16 horas de isquemia, con buenos resultados en la clínica, en resección de tumores, pero se desconoce su efecto en el modelo de trasplante hepático con injerto de tamaño reducido en la rata. En la presente tesis se ha demostrado que el PC es una estrategia útil frente a la lesión por I/R y que favorece la regeneración asociada al modelo de trasplante hepático de tamaño reducido en la rata, modulando factores de crecimiento, como el factor de crecimiento hepatocitario (HGF) y el factor de crecimiento transformante-beta (TGF-beta), modulando la producción de radicales libres (RLO) (por parte de las células de kupffer) y todo esto cursa a través de la disminución de la IL-alfa y con una implicación del óxido nítrico (NO). Sin embargo, el PC no ejerce su papel protector mediante cambios en el sistema productor de RLO xantina/xantina oxidasa, cambios en los niveles de las citoquinas TNF-alfa y IL-6, ni mediante la preservación del metabolismo energético. Por otra vía independiente del NO, el PC estimula la expresión de la Heat shock protein (HSP) 70 y HO-1, estimulando la regeneración en el caso de la HSP70 y disminuyendo la lesión y estimulando la regeneración en el caso de la HO-1. Por otro lado, el PC fue capaz de conferir protección a nivel pulmonar, así la disminución de la IL-1alfa se tradujo en una disminución en los niveles de TNF-alfa plasmáticos y un aumento del receptor soluble de TNF-alfa de tipo 2 (sTNFR2), que es capaz de inactivar el TNF-alfa libre en la circulación sanguínea, evitando los efectos nocivos del TNF-alfa a nivel pulmonar. / Reduced-size liver transplantation (RSLT) was developed to arise the number of available liver grafts In addition to ischemia/reperfusion (I/R) injury associated to liver transplantation, the reduced grafts have to overcome a necessary regeneration process. I/R injury has deleterious systemic effects, leading to pulmonary complications. Ischemic preconditioning (IP) is able to protect liver against I/R injury and lung damage in conventional rat liver transplantation. Recently, has been published its clinical application in tumour resections. In the present thesis work, it has been demonstrated the IP is able to reduce I/R injury and stimulate regeneration associated to RSLT. IP modulated growth factors, as hepatocyte growth factor and transforming growth factor-beta and the stress oxidative production, and it was related to the reduction of IL-1alpha levels . Nitric oxide (NO) was implicated in the benefits of IP. However, PC has not any effect on xanthine/xanthine oxidase system, neither on IL-6 and TNF-alpha levels and energetic metabolism. By another pathway independent of NO, IP induced heat shock protein 70 (HSP70) and haem-oxygenase-1 (HO-1). HO-1 protected against I/R injury and liver regeneration, whereas the benefits resulting from HSP70 were mainly related to hepatocyte proliferation. On the other hand, IP was able to confer lung protection. In this line, reduction of IL.-1alpha levels was associated with lower TNF-alpha and higher soluble receptor TNF-alpha type 2 (sTNFR2) plasma levels.
6

A novel synthetic route towards anti-inflammatory mediator : Resolvin E1

Pearson, Danielle L. January 2018 (has links)
The health benefits of fish oil supplementations have been proven to be effective by several studies which are discussed in this thesis. It was found that these compounds had potent anti-inflammatory properties and since then has prompted much research into the use of these compounds as potential treatments for chronic inflammation based diseases, where the overuse of current anti-inflammatory drugs cause many problems with undesired side-effects. The aim of this research is to study the bioactivity of resolvin E1 and various analogues, and to determine a novel route towards resolvin E1 natural product so that bioactivity tests may be conducted in comparison of synthetically produced resolvin E1 and naturally extracted resolvin E1. The initial aim of this research was to develop a range of analogues of a fragment of Resolvin E1. This was so that a series of compounds could be produced with various R groups to identify any structure-activity relationships for this part of the natural product. There is one stereocentre in this fragment of resolvin E1 and it was decided that a racemic version of these compounds would be tested for bioactivity, and if any of the compounds had significant anti-inflammatory properties then the R and S versions could be separated, allowing for the testing of both enantiomers to determine which gave the most potent anti-inflammatory response. This led to the creation of several novel fragments and their biological testing. The secondary aim of the project was to complete the total synthesis of the resolvin E1 natural product. We devised a novel route towards resolvin E1 which used MIDA boronate protecting group to introduce a fixed trans double bond which was useful in a compound with multiple alkene systems. Resolvin E1 also contains three stereocentres, the synthesis from the fragment work was recycled to begin the synthesis, and made use of 1,2:5,6-di-O-isopropylidene-D-mannitol and Noyori s catalyst to setup the stereocentres. The use of new MIDA-boronate moieties were also explored in order to develop a new, efficient synthesis toward resolvin E1.
7

Zooplankton structure and dynamics in Mediterranean marshes (Empordà Wetlands): a size-based approach

Brucet Balmaña, Sandra 04 November 2003 (has links)
Zooplankton community structure (composition, diversity, dynamics and trophic relationships) of Mediterranian marshes, has been analysed by means of a size based approach. In temporary basins the shape of the biomass-size spectra is related to the hydrological cycle. Linear shape spectra are more frequent in flooding situations when nutrient input causes population growth of small-sized organisms, more than compensating for the effect of competitive interactions. During confinement conditions the scarcity of food would decrease zooplankton growth and increase intra- and interspecific interactions between zooplankton organisms which favour the greatest sizes thus leading to the appearance of curved shape spectra.Temporary and permanent basins have similar taxonomic composition but the latter have higher species diversity, a more simplified temporal pattern and a size distribution dominated mainly by smaller sizes. In permanents basins zooplankton growth is not only conditioned by the availability of resources but by the variable predation of planktivorous fish, so that the temporal variability of the spectra may also be a result of temporal differences in fish predation.Size diversity seems to be a better indicator of the degree of this community structure than species diversity. The tendency of size diversity to increase during succession makes it useful to discriminate between different succession stages, fact that is not achieved by analysing only species diversity since it is low both under large and frequent or small and rare disturbances. Amino acid composition differences found among stages of copepod species indicate a gradual change in diet during the life cycle of these copepods, which provide evidence of food niche partitioning during ontogeny, whereas Daphnia species show a relatively constant amino acid composition. There is a relationship between the degree of trophic niche overlap among stages of the different species and nutrient concentration. Copepods, which have low trophic niche overlap among stages are dominant in food-limited environments, probably because trophic niche partitioning during development allow them to reduce intraspecific competition between adults, juveniles and nauplii. Daphnia species are only dominant in water bodies or periods with high productivity, probably due to the high trophic niche overlap between juveniles and adults. These findings suggest that, in addition to the effect of interspecific competition, predation and abiotic factors, the intraspecific competition might play also an important role in structuring zooplankton assemblages. / L'estructura de la comunitat zooplanctònica dels Aiguamolls de l'Empordà, composició específica, dinàmica, diversitat i relacions tròfiques, s'ha estudiat a partir d'una aproximació basada en la mida. L'aproximació s'ha basat en la modelització de l'espectre de mida-biomassa de la comunitat zooplanctònica a partir de la distribució de Pareto. S'ha observat que la forma de l'espectre de mida-biomassa del zooplàncton canvia segons les condicions ambientals: en situacions d'entrada d'aigua són més freqüents els espectres lineals ja que les entrades de nutrients causen un creixement dels organismes de mida petita de manera que es sobrecompensa l'efecte de les interaccions competitives. Els espectres corbats són més freqüents en situacions de confinament quan els recursos són escassos i les interaccions ecològiques entre els organismes prenen més rellevància de manera que es veuen més afavorides les espècies de mida gran que les de mida petita. Les comunitats zooplanctòniques de les diferents llacunes de la maresma tenen una composició taxonòmica similar però una diversitat d'espècies, un patró estacional i una distribució de mides diferents. En el patró estacional de les llacunes temporànies es poden distingir sis situacions que estan condicionades per el cicle hidrològic i dominades per les següents espècies: Synchaeta spp, Diacyclops bicuspidatus, Eurytemora velox. Calanipeda aquae-dulcis, Cletocamptus confluens i Brachionus plicatilis. La llacuna permanent, tot i presentar una diversitat més alta que les temporànies, té un patró estacional més simple, amb només dues situacions: la situació de Synchaeta spp. i la de C. aquae-dulcis. Aquest patró estacional més reduït i una distribució de mides dominada principalment per organismes de mida petita s'explicarien per la pressió de depredació dels peixos en aquesta llacuna. Així, la variació en la forma de l'espectre de mida-biomassa de les comunitats zooplanctòniques de la llacuna permanent no està únicament relacionat amb el cicle higrològic sinó amb la pressió de depredació dels peixos.La distribució de Pareto es pot utilitzar per calcular un índex de diversitat de mides (μs'). En el cas de la comunitat de zooplàncton la diversitat de mides ha resultat ser un millor indicador del nivell d'estructuració que la diversitat d'espècies, els augments de la qual moltes vegades no són deguts a una elevada estructuració de la comunitat. La tendència a augmentar al llarg de la successió fa que la diversitat de mides pugui discriminar entre diferents estadis de la successió, en canvi això no es possible a partir de la diversitat d'espècies ja que pot assolir valors elevats tant en moments de pertorbacions elevades i freqüents com en moments de pertorbacions petites i escasses. En llacunes temporànies, valors alts de diversitat de mides coincideixen en períodes de dominància d'una espècie de calanoid, períodes que representen les situacions més estables en aquestes llacunes. L'anàlisi de la composició d'aminoàcids (AAC) ens demostra que les espècies de copèpodes dominants als Aiguamolls de l'Empordà mostren un canvi gradual en la seva composició bioquímica al llarg de la seva ontogènesi. Aquestes diferències en la AAC entre estadis no són degudes a diferències filogenètiques ni a les condicions ambientals, sinó a variacions en la dieta. Així, les diferents espècies de copèpodes mostren una repartició del nínxol tròfic entre els seus estadis de desenvolupament. Pel que fa a les espècies de dàfnids, mostren una AAC relativament constant durant el seu desenvolupament, fet que indicaria que tot els estadis s'alimenten del mateix recurs, és a dir, que juvenils i adults mostren un solapament del nínxol tròfic. La relació trobada entre la concentració de nutrients de les llacunes i el grau de solapament entre estadis de les espècies dominants mostra que la repartició del nínxol tròfic entre joves i adults és un possible mecanisme per tal d'evitar la competència intraespecífica. Els copèpodes, que tenen un baix solapament entre estadis, dominen en ambients on el recurs és limitat ja que la repartició del nínxol tròfic durant el desenvolupament els permet reduir la competència per l'aliment entre estadis. En les espècies de dàfnids, l'elevat solapament entre joves i adults els restringeix en llacunes o períodes amb elevada productivitat per tal d'evitar la competència intraespecífica. Així doncs, la competència intraespecífica juga un paper important a l'hora d'estructurar la comunitat de zooplàncton, juntament amb els dos altres factors que sovint són citats, la depredació i la competència interspecífica.
8

Italský a sicilský pijut v dobovém kontextu a jeho jedinečný přínos pozdější básnické tvorbě / Italian and Sicilian Piyyut in contemporary Contex and its unique Contribution to futher poetical Output

Ondrejičková, Sylva January 2011 (has links)
Hermeneutic rules (so-called middot), which developed during the process of the rabbinic literature formation, partially under sopherims' or Greek influence, provided with one of the main viewpoints of hypotext choice in poetry, ruled a combination and an arrangement of elements in poetry. These principles, differenciated during the 2nd century A.D. into two systems - r. Yishma'el's and r. Eli'eser b. Josi ha-gelili's lists (for halakhic and aggadic interpretation) underwent a process of contraction in piyyut. From the recent point of view is the rabbinic hypotext identification possible at most half, since partially poets advanced on the basis of the midrashic texts available, different from extant textual versions. On the basis of original textual variants connected with the identification of the hypotext, this thesis arrived at a comparative work on the development and the understanding of implicite and explicite application of hermeneutic rules. The synagogal poetry assumed a didactical function and historical remembrance function following pre-classical period. As a result of poetic activity the originated the didactical text, which instructed, assisted at the preservation of lessons and topoi taught in yeshibot (Ashkenaz), scholarly circles (Rome, Apulia, Calabria) and later on in synagogues.
9

Coordination Chemistry of Monocarboxylate and Aminocarboxylate Complexes at the Water/Goethite Interface

Norén, Katarina January 2007 (has links)
<p>This thesis is a summary of five papers with focus on adsorption processes of various monocarboxylates and aminocarboxylates at the water/goethite interface. Interaction of organic acids at the water/mineral interfaces are of importance in biogeochemical processes, since such processes have potential to alter mobility and bioavailability of the acids and metal ions.</p><p>In order to determine the coordination chemistry of acetate, benzoate, cyclohexanecarboxylate, sarcosine, MIDA (methyliminediacetic acid), EDDA (ethylenediamine-N,N’-diacetic acid) and EDTA (ethylenediamine-N,N’-tetraacetic acid) upon adsorption to the goethite (alpha-FeOOH) surface, a combination of quantitative measurements with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was utilized.</p><p>Over the pH range studied here (pH 3- 9) all ligands, except for sarcosine, have been found to form surface complexes with goethite. In general, theses were characterized as outer sphere surface complexes i.e. with no direct interaction with surface Fe(III) metal ions. Furthermore, two types of different outer-sphere complexes were identified, the solvent-surface hydration-separated ion pair, and hydration-shared ion pair. For the monocarboxylate surface complexes distinction between these two could be made. At high pH values the solvent-surface hydration-separated ion pair was the predominating complex, while at low pH the surface complex is stabilized through the formation of strong hydrogen bonds with the goethite surface. However, it was not possible to clearly separate between the two outer-sphere complexes for coordination of the aminocarboxylates with the surface of goethite. Additionally, EDDA also formed an inner-sphere surface complex at high pH values. The EDDA molecule was suggested to coordinate to the surface by forming a five membered ring with an iron at the goethite surface, through the amine and carboxylate groups.</p><p>Contrary to the other ligands studied, EDTA significantly induced dissolution of goethite. Some of the dissolved iron, in the form of the highly stable FeEDTA- solution complex, was indicated to re-adsorb to the mineral surface as a ternary complex. Similar ternary surface complexes were also found in the Ga(III)EDTA/goethite system, and quantitative and spectroscopic studies on adsorption of Ga(III) in presence and absence of EDTA showed that EDTA considerably effects speciation of gallium at goethite surface.</p><p>The collective results in this thesis show that the affinity of these ligands for the surface of goethite is primarily governed by their chemical composition and structure, and especially important are the types, numbers and relative position of functional groups within the molecular structure.</p>
10

Oxida??o ?mida de fen?is com catalisadores de ferro suportado em argilominerais em reator de leito de lama (slurry) / Phenol Wet oxidation on catalyst supported in clay minerals using a reactor with mechanical agitation (slurry)

Santiago J?nior, Aristides Felipe 15 October 2010 (has links)
Made available in DSpace on 2014-12-17T15:01:51Z (GMT). No. of bitstreams: 1 AristidesFSJ_TESE.pdf: 1616188 bytes, checksum: 162e291640cf71e1607267c17f431e17 (MD5) Previous issue date: 2010-10-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The wet oxidation of organic compounds with CO2 and H2O has been demonstrated to be an efficient technique for effluent treatment. This work focuses on the synthesis, characterization and catalytic performance of Fe-MnO2/CeO2, K-MnO2/CeO2/ palygorskite and Fe/ palygorskite toward the wet oxidative degradation of phenol. The experiments were conducted in a sludge bed reactor with controlled temperature, pressure and stirring speed and sampling of the liquid phase. Experiments were performed on the following operating conditions: temperature 130 ? C, pressure 20.4 atm, catalyst mass concentration of 5 g / L initial concentration of phenol and 0.5 g / L. The catalytic tests were performed in a slurry agitated reactor provided with temperature, pressure and agitation control and reactor liquid sampling. The influences of iron loaded on the support (0.3; 7 and 10%, m/m) and the initial pH of the reactant medium (3.1; 6.8; 8.7) were studied. The iron dispersion on the palygorskite, the phase purity and the elemental composition of the catalyst were evaluated by X-Ray Difraction (XRD), Scanning Electron Microscopy (SEM) and X-Ray Flourescence (XRF). The use of palygorskite as support to increase the surface area was confirmed by the B.E.T. surface results. The phenol degradation curves showed that the Fe3+ over palygorskite when compared with the other materials tested has the best performance toward the (Total Organic carbonic) TOC conversion. The decrease in alkalinity of the reaction medium also favors the conversion of TOC. The maximum conversion obtained from the TOC with the catalyst 3% Fe / palygorskite was around 95% for a reaction time of 60 minutes, while reducing the formation of acids, especially acetic acid. With products obtained from wet oxidation of phenol, hydroquinone, p-benzoquinone, catechol and oxalic acid, identified and quantified by High Performance Liquid Chromatography was possible to propose a reaction mechanism of the process where the phenol is transformed into the homogeneous and heterogeneous phase in the other by applying a kinetic model, Langmuir-Hinshelwood type, with evaluation of kinetic constants of different reactions involved. / A oxida??o ?mida de compostos org?nicos a CO2 e H2O tem demonstrado ser uma t?cnica interessante no tratamento de efluentes. Este trabalho tem como objetivo a s?ntese e caracteriza??o dos catalisadores Fe-MnO2/CeO2, K-MnO2/CeO2/paligorsquita e Fe/paligorsquita, assim como, a avalia??o na degrada??o oxidativa do fenol. Os experimentos foram realizados em um reator de leito de lama, com controle de temperatura, de press?o e de velocidade de agita??o e com coleta de amostras da fase l?quida. Os Experimentos foram executados nas seguintes condi??es operacionais: temperatura de 130 oC, press?o de 20,4 atm, concentra??o m?ssica do catalisador de 5 g/L e concentra??o inicial do fenol de 0,5 g/L. Os par?metros avaliados foram: teor de ferro impregnado (0,3; 7 e 10% em massa) e o pH do meio reacional (3,1; 6,8 e 8,7). Os resultados da caracteriza??o por DRX, MEV e FRX mostraram a dispers?o do ferro na paligorsquita, a pureza das fases e, finalmente, a composi??o dos elementos que constituem o catalisador. O uso da paligorsquita como suporte eleva a ?rea especifica superficial do catalisador que foi confirmada por an?lise BET. As curvas de degrada??o do fenol indicam que o catalisador Fe3+ suportado em paligorsquita tem um papel preponderante na convers?o de Carbono Org?nico Total (COT) quando comparado aos demais catalisadores. A diminui??o da alcalinidade do meio reacional favorece tamb?m a convers?o de COT. A convers?o m?xima de COT obtida com o catalisador 3% Fe/paligorsquita, foi em torno de 95 % para um tempo de rea??o de 60 minutos, reduzindo ao mesmo tempo a forma??o de ?cidos, em especial o ?cido ac?tico. Com os produtos obtidos da oxida??o ?mida do fenol, hidroquinona, p-benzoquinona, catecol e ?cido ox?lico, identificados e quantificados por Cromatografia L?quida de Alta Efici?ncia, foi poss?vel propor um mecanismo do processo reacional onde o fenol ? transformado em fase homog?nea e os demais em fase heterog?nea. Aplicou-se um modelo cin?tico, tipo Langmuir- Hinshelwood, com avalia??o das constantes cin?ticas das diferentes rea??es envolvidas

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