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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

An?lise de mistura de componentes de ?leo decantado por meio de DOSY/RMN auxiliada por matrizes / Mixing analysis of oil components decanted by means of DOSY / RMN assisted by matrices

Almeida , Vitor dos Santos 15 April 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-02-15T16:34:59Z No. of bitstreams: 1 2016 - Vitor dos Santos Almeida.pdf: 2652432 bytes, checksum: 7f27ae8d8b345f1dc55ee863302bfda7 (MD5) / Made available in DSpace on 2017-02-15T16:34:59Z (GMT). No. of bitstreams: 1 2016 - Vitor dos Santos Almeida.pdf: 2652432 bytes, checksum: 7f27ae8d8b345f1dc55ee863302bfda7 (MD5) Previous issue date: 2016-04-15 / The analysis of mixtures is a common place challenge in the laboratory. Conventional methods demand a previous treatment which may be time consuming. At present, Nuclear Magnetic Resonance may be employed for the analysis of mixtures by using the DOSY (diffusion ordered spectroscopy) technique, whereby the different components of a mixture are separated by their diffusion coefficients. Pitches, in general, are products which are employed as starting material for the production of a variety of carbon materials, such as anodes for the production of aluminum, graphite electrodes for the steel industry, and carbon fibers. Pitches obtained from coal tar, itself a residue in the production of coke, are the most traditionally used. However, it is a carcinogen and therefore has had its use greatly diminished. Petroleum pitches, which are produced from decanted oil, may be a safer and less expensive alternative. The decanted oil is a heavy fraction obtained from catalytic cracking of petroleum. The difficulties in controlling its processing are derived from its complex composition, which includes paraffins, aromatic and heteroaromatic compounds. The present work investigates the analysis by NMR-DOSY of a mixture of model compounds present in decanted oil. Thus, a mixture of Tetracosane, Phenanthrene, 9-Mehylanthracene, Pyrene, Carbazole, 9-metil Carbazol, Dibenzothiophene, Dibenzofuran, Hexadecane, 1-Methylnaphthalene, Thiophene, Tetrahydrofuran was analyzed by NMR with an Avance III 500 MHz NMR spectrometer equipped with a BBO probe with a gradient on z-axis, at 20?C. To help in the separation by diffusion, the following polymers were used: poly-(ethyleneglycol), poly-(vinylpyrrolidone), poly-(dimethylsiloxan), poly-(butylmethacrylate) e poly-(vinylacetate).The shift reagent Eu(fod)3 was also employed. The results from DOSY-INEPT experiments show that poly-(butylmethacrylate) is the matrix which afforded the best separation of the different components of the mixture, followed by poly-(vinylacetate), poly-(ethyleneglycol) and finally, poly-(vinylpyrrolidone), which showed satisfactory results / Um grande desafio, muitas das vezes at? comum nos laborat?rios, ? a an?lise de misturas. Os m?todos convencionais em sua maioria exigem um tratamento pr?vio das misturas, o que demanda tempo, al?m de interferir diretamente no equil?brio do sistema. Hoje em dia, a t?cnica de Resson?ncia Magn?tica Nuclear pode ser usada na an?lise de misturas medindo-se o coeficiente de difus?o dos componentes da mistura, permitindo a obten??o dos espectros de cada componente individualmente por meio de um experimento r?pido que n?o interfere na mistura em si. O experimento mais comum ? o DOSY, do ingl?s Espectroscopia de Difus?o Ordenada. Piches, em geral, s?o produtos que s?o empregados como mat?rias-primas na produ??o de uma variedade de materiais de carbono, tais como: anodos de carbono para produ??o de alum?nio, eletrodos de grafite para a ind?stria sider?rgia e fibras de carbono. Piches obtidos a partir do alcatr?o da hulha, res?duo da produ??o de coque metal?rgico, s?o os tradicionalmente mais usados, mas apresentam alto potencial carcinog?nico e tem demanda decrescente em fun??o de novas tecnologias empregadas nas coquerias. Piches de petr?leo, produzidos a partir de ?leos decantados, podem potencialmente constituir uma alternativa mais segura e com maior disponibilidade. O ?leo decantado ? uma fra??o pesada obtida nas unidades de craqueamento catal?tico fluido no refino de petr?leo, e o controle de seu processamento ? dificultado pela complexidade de sua composi??o, que inclui compostos paraf?nicos, homoarom?ticos e heteroarom?ticos. O presente trabalho se prop?em a investigar a an?lise por RMN de uma mistura de padr?es de subst?ncias representativas dos tipos de compostos presentes no ?leo decantado. Assim, foram escolhidos padr?es de Tetracosano, Fenantreno, 9-metil Antraceno, Pireno, Carbazol, 9-metil Carbazol, Dibenzotiofeno, Dibenzofurano, Hexadecano, 1-metil Naftaleno, Tiofeno, Tetrahidrofurano. Todos os experimentos foram realizados no laborat?rio de RMN do PPGQ-UFRRJ a 20?C com o espectr?metro de RMN de 500 MHz Bruker Avance III, equipado com sonda BBO, gradiente no eixo z. Para auxiliar na separa??o dos componentes da mistura foram usados o pol?mero poli-(etilenoglicol), poli-(vinilpirrolidona), poli-(dimetilsiloxano), poli-(metacrilato de butila) e poli-(acetato de vinila), al?m do reagente de deslocamento Eu(fod)3. Os resultados obtidos a partir dos experimentos de DOSY-INEPT mostraram que o pol?mero PMAB foi a matriz que mais auxiliou na separa??o dos componentes da mistura em quest?o no presente trabalho, sendo seguido pelas matrizes PAV, PEG e PVP, que tamb?m apresentaram resultados satisfat?rios
12

Estudo do efeito de substituintes na fotoqu?mica de tioxantona por fot?lise por pulso de laser em nanossegundo / Study of the effect of substituents In the photochemistry of thioxanthone by Laser pulse photolysis in Nanosecond

Rodrigues, Janaina de Faria 15 June 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-08-18T16:17:20Z No. of bitstreams: 1 2010 - Janaina de Faria Rodrigues.pdf: 2153676 bytes, checksum: 8429cd74e923c45f3d05970bcdff87d2 (MD5) / Made available in DSpace on 2017-08-18T16:17:20Z (GMT). No. of bitstreams: 1 2010 - Janaina de Faria Rodrigues.pdf: 2153676 bytes, checksum: 8429cd74e923c45f3d05970bcdff87d2 (MD5) Previous issue date: 2010-06-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico, CNPq, Brasil. / By laser flash photolysis, the photo-reactivity of the triplet excited state of thioxanthone derivatives (2BTX, 2MeOTX, 2PrOTX and 2MeTX) was studied. The maximum wavelength and triplet time life of theirs transients are solvent dependents, a blue-shift is observed with the change of no polar to polar middle and still more in hydroxyl solvent. The triplet spectrum with hydrogen-donor solvents shows a slower broad band between 430-460nm that again is observed with hydrogen-donor quenchers, this band is attributed to ketyl radical. The broad bands in 410 and 500nm are attributed to phenoxyl, indolyl radicals and ions radicals as intermediates, respectively. The higher values to hydrogen transference from alcohols (~105 M-1s-1) and allylic hydrocarbons and phenols (~109 M-1s-1) are attributed to the triplet excited state of lower energy have a mixture of excited states with predominant character of the excited state with n?*. The no dependence to substituted-phenols on Kq and the approximated values between then and TEA, DABCO and indole (~109 M-1s-1) are indicating a mechanism by electron-transference followed a faster proton transference from an exciplex. The quenching rate contants by transfer of energy from trans-stilbene, 1-methylnaphthalene and 1,3-cyclohexadiene are controlled by diffusion for 2MeTX remaining triplet energy over 61 kcal.mol-1, as observed for TX. For the other substituents was a decrease in triplet energy is getting between 53 and 61 kcal.mol-1. / Utilizando-se a t?cnica de fot?lise por pulso de laser, foram estudadas a fotorreatividade do estado triplete de derivados de tioxantona (9-H-tioxanton-9-ona). Os espectros de absor??o T1?Tn para os derivados 2-benzil?xi, 2-met?xi, 2-prop?xi e 2-metil (2BTX, 2MeOTX, 2PrOTX e 2MeTX), obtidos em diversos solventes, mostram que estes se comportam de forma selhante a tioxantona. O comprimento de onda m?ximo bem como o tempo de vida de seus transientes s?o dependentes da polaridade do meio. Observou-se o deslocamento hipsocr?mico com a mudan?a de um solvente apolar para um solvente polar, tendo sido mais acentuado para os solventes polares hidroxil?cos. Nos espectros de absor??o T1?Tn em solventes doadores de hidrog?nio foi poss?vel observar a forma??o de uma banda entre regi?o de 430-460nm que foi observada novamente nas rea??es com supressores de energia triplete doadores de hidrog?nio, sendo esta banda atribu?da ao radical cetila. As bandas formadas na regi?o de 410 e 500nm s?o atribu?das ao radical fenoxila e indolila, respectivamente. Os altos valores para as constantes de velocidade de rea??o de supress?o por transfer?ncia de hidrog?nio com ?lcoois (~105 M-1s-1), hidrocarbonetos al?licos e fen?is (~109 M-1s-1) s?o atribu?dos ao fato de que o estado excitado triplete de mais baixa energia apresentar uma mistura de estados excitado com predomin?ncia do car?ter n?*. A n?o depend?ncia das kq para os fen?is de seus substituintes e os valores pr?ximos das rea??es para trietilamina, DABCO e indol indicam que o mecanismo de rea??o passa por uma primeira etapa de transfer?ncia de el?trons seguida de uma r?pida transfer?ncia de pr?ton a partir da forma??o de um exciplexo. As constantes de velocaide de rea??o de supress?o por transfer?ncia de energia com trans-estilbeno, 1-metil-naftaleno e 1,3-cicloexadieno s?o controladas por difus?o para 2MeTX estando a energia triplete de T1 acima de 61 kcal.mol-1, como o observado para a TX; j? para os demais substituintes houve uma diminui??o da energia triplete ficando esta entre 53 kcal.mol-1 e 61 kcal.mol-1.
13

Estudo semiempirico da inibi??o da AChE por policet?deos extra?dos da esponja marinha Plakortis angulospiculatus. / Semi-empirical study of inhibition of AChE by polyketides Extracted from the marine sponge Plakortis angulospiculatus.

Silva, Suzana Vieira 12 June 2009 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-08-29T13:03:42Z No. of bitstreams: 1 2009 - Suzana Vieira da Silva.pdf: 1145565 bytes, checksum: cb8b708d2e722a6ccc8d9c091be5270f (MD5) / Made available in DSpace on 2017-08-29T13:03:42Z (GMT). No. of bitstreams: 1 2009 - Suzana Vieira da Silva.pdf: 1145565 bytes, checksum: cb8b708d2e722a6ccc8d9c091be5270f (MD5) Previous issue date: 2009-06-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior. CAPES / The Evil of Alzheimer is a disease neurodegenerativa that reaches to the cognitive functions among them the memory, attention and learning. The main strategy used for his/her treatment is addressed in the search of improving the hipofun??o colin?rgica, inhibiting the enzyme acetylcholinesterase, so that the acetylcholine can stay more available in the rift sin?ptica for the accomplishments of the sinapses, since this enzyme has the hidrolisar function the acetylcholine. The nature offers an enormous variety of substances used as f?rmacos and the sea sponges has been demonstrating be rich in these substances. They were extracted of the sponge Plakortis angulospiculatus three polyketides that through the method Ellman demonstrated activity anticolinester?sica. Through techniques of Molecular Modelling, calculations semiempiricos were accomplished using the method PM3 to analyze the geometric interactions and energies involved in the compound polyketidesacetylcholinesterase with the objective of analyzing a possible use of these as f?rmacos for the Evil of Alzheimer. As if he/she didn't know the state in that the ranch would be (with Ser200 and neutral His440 or no) in the moment of the interaction, calculations were accomplished for the three polyketides in both ranches. Studies with inhibitors already known tacrina and huprina X (both neutral one and protonadas) they were also accomplished at both ranches in order to comparison. Resulted obtained he in this work showed the reliability of the employed method, likewise as values of favorable entalpia for the formation of all the compounds independent pollyketide-acetylcholinesterase of the ranch. It was observed by the energy values a preference when the same ones if they found in the ranch protonado diferencialmente of the inhibitors tacrina and huprina X that independent of his/her state (protonados or no) they showed better interaction for the neutral ranch. The calculations accomplished for the tacrina demonstrated that even after optimization the main interactions described already by the literature stayed and that possibly she meets protonada inside of the seen ranch the values of energy found for this structure. The huprina X that is a hybrid of the tacrina with the huperzina A it showed HER likewise the most significant interactions as the more favorable energy values, what is in agreement with the high constant of inhibition of 26pM found in the literature for human's acetilcolinesterase. Before the obtained data we can end that the polyketides in spite of they obtain favorable energy values the formation of the compound polyketide-acetylcholinesterase these values are not competitive with the energy values found for the inhibitors tacrina and huprina X. however, in the production of a f?rmaco they are not taken into account just energy interactions and as the tacrina it already demonstrated to possess high hepatic toxicity, besides adverse reactions as nausea and vomit, the polyketides for they be natural substance were able to in this case be competitive if they demonstrated to possess softer adverse reactions. / O Mal de Alzheimer ? uma doen?a neurodegenerativa que atinge ?s fun??es cognitivas entre elas a mem?ria, aten??o e aprendizagem. A principal estrat?gia utilizada para seu tratamento est? direcionado na busca de melhorar a hipofun??o colin?rgica, inibindo a enzima acetilcolinesterase, para que a acetilcolina possa permanecer mais dispon?vel na fenda sin?ptica para as realiza??es das sinapses, j? que esta enzima tem a fun??o de hidrolisar a acetilcolina. A natureza oferece uma enorme variedade de subst?ncias utilizadas como f?rmacos e as esponjas marinhas tem demonstrado serem ricas nestas subst?ncias. Foram extra?dos da esponja Plakortis angulospiculatus tr?s policet?deos que atrav?s do m?todo Ellman demonstraram atividade anticolinester?sica. Atrav?s de t?cnicas de Modelagem Molecular, foram realizados c?lculos semiempiricos utilizando o m?todo PM3 para analisar as intera??es geom?tricas e energias envolvidas no complexo policet?deos-acetilcolinesterase com o objetivo de analisar uma poss?vel utiliza??o destes como f?rmacos para o Mal de Alzheimer. Como n?o se conhecia o estado em que o s?tio se encontraria (com a Ser200 e His440 neutros ou n?o) no momento da intera??o, foram realizados c?lculos para os tr?s policet?deos em ambos os s?tios. Estudos com inibidores j? conhecidos tacrina e huprina X (ambas neutra e protonadas) tamb?m foram realizados em ambos os s?tios a fim de compara??o. O resultados obtidos neste trabalho mostraram a confiabilidade do m?todo empregado, assim tamb?m como valores de entalpia favor?veis para a forma??o de todos os complexos policet?deo-acetilcolinesterase independente do s?tio. Observou-se pelos valores energ?ticos uma prefer?ncia quando os mesmos se encontravam no s?tio protonado diferencialmente dos inibidores tacrina e huprina X que independente do seu estado (protonados ou n?o) mostraram melhor intera??o pelo s?tio neutro. Os c?lculos realizados para a tacrina demonstraram que mesmo ap?s otimiza??o as principais intera??es j? descritas pela literatura se mantiveram e que possivelmente ela se encontra protonada dentro do s?tio visto os valores de energia encontrados para esta estrutura. A huprina X que ? um h?brido da tacrina com a huperzina A mostrou as intera??es mais significativas assim tamb?m como os valores energ?ticos mais favor?veis, o que est? de acordo com a alta constante de inibi??o de 26pM encontrados na literatura para a acetilcolinesterase de humano. Diante dos dados obtidos podemos concluir que os policet?deos apesar de obterem valores energ?ticos favor?veis a forma??o do complexo policet?deo-acetilcolinesterase estes valores n?o s?o competitivos com os valores energ?ticos encontrados para os inibidores tacrina e huprina X. No entanto, na fabrica??o de um f?rmaco n?o s?o levados em conta apenas intera??es energ?ticas e como a tacrina j? demonstrou possuir alta toxicidade hep?tica, al?m de rea??es adversas como n?usea e v?mito, os policet?deos por serem subst?ncia naturais poderiam neste caso ser competitivos se demonstrassem possuir rea??es adversas mais brandas.
14

Sintese e avalia??o de atividade tripanocida de novos heterociclos da classe dos 1,2,4-OXADIAZ?IS, derivados e an?logos da amida natural piperina. / SYNTHESIS AND EVALUATION OF TRIPANOCIDAL ACTIVITY OF NEW HETEROCYCLES OF THE 1,2,4-OXADIAZIAL CLASS, DERIVATIVES AND ANALOGS OF THE NATURAL AMID PIPERINA.

Soares, Breno Almeida 25 September 2009 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-08-29T14:02:13Z No. of bitstreams: 1 2009 - Breno Almeida Soares.pdf: 7105040 bytes, checksum: 3b6aebf34151816545510b0506ed3412 (MD5) / Made available in DSpace on 2017-08-29T14:02:13Z (GMT). No. of bitstreams: 1 2009 - Breno Almeida Soares.pdf: 7105040 bytes, checksum: 3b6aebf34151816545510b0506ed3412 (MD5) Previous issue date: 2009-09-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. / This work is part of a research project which investigates the utilization of abundant and accessible natural products in the synthesis of new molecules with potential activity against Chagas? disease. Recent studies carried out in our laboratory showed activity against Trypanosoma cruzi for piperine, a major component of Piper nigrum and for a series of its derivatives and analogues. Using bioisosterism as a strategy for molecular modification, we describe here the design, synthesis and antiparasitic evaluation of class of derivatives of 1,2,4-oxadiazole. The key step of the synthetic strategy used involved the SNAC reaction of the benzamidoxima with acid chlorides followed by cyclization, which allowed the preparation of eight new 1,2,4-oxadiazole The evaluation of the toxic activity of these new derivatives against epimastigote form of T. cruzi confirmed the bioisosteric relationship between the natural amide and the new products prepared, showing the oxadiazole 55 direct derived from piperine, as the most active compound in the series. / Este trabalho se insere numa linha de pesquisa que visa a utiliza??o de produtos naturais abundantes e access?veis na s?ntese de novas mol?culas com potencial atividade anti-chag?sica. Estudos recentes em nosso laborat?rio demonstraram a atividade antiparasit?ria da piperina e de uma s?rie de derivados e an?logos sobre o Trypanosoma cruzi, agente etiol?gico da doen?a de Chagas. Utilizando o bioisosterismo como estrat?gia de modifica??o molecular, descrevemos aqui o planejamento, a s?ntese e a avalia??o antiparasit?ria de derivados da classe dos 1,2,4-oxadiaz?is. A etapa-chave da estrat?gia sint?tica utilizada envolveu a rea??o de SNAC da benzamidoxima com cloretos de ?cidos, seguida de cicliza??o, que permitiu a prepara??o de oito novos 1,2,4- oxadiaz?is. A avalia??o da atividade t?xica destes novos derivados contra a forma epimastigota do T. cruzi confirmou a rela??o bioisost?rica entre a amida natural e os novos derivados preparados, evidenciando o oxadiazol 55 derivado direto da piperina, como o composto mais ativo da s?rie.
15

Estudo Fitoqu?mico de Justicia wasshauseniana (Acanthaceae), Tetrapterys acutifolia e Lophanthera lactescens (Malpighiaceae) e Atividades biol?gicas / Phytochemical study of Justicia wasshauseniana (Acanthaceae), Tetrapterys acutifolia and Lophanthera lactescens (Malpighiaceae) and Biological activities

Fernandes, Renata Duarte 13 December 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-09-08T13:08:22Z No. of bitstreams: 1 2016 - Renata Duarte Fernandes.pdf: 6635666 bytes, checksum: ab405bd813ed887b89c988abc6b8f7ea (MD5) / Made available in DSpace on 2017-09-08T13:08:22Z (GMT). No. of bitstreams: 1 2016 - Renata Duarte Fernandes.pdf: 6635666 bytes, checksum: ab405bd813ed887b89c988abc6b8f7ea (MD5) Previous issue date: 2016-12-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This work describes the isolation and structural determination of special metabolites isolated from leaf and stem of J. wasshauseniana (Acanthaceae), popularly known as a coati tail, which was collected in the Paracambi, RJ; Leaves and stem of T. acutifolia (Malpighiaceae), popularly known as cip?-ro?o, were collected in the Barra do Pira?-RJ and leaf and bark of L. lactescens (Malpighiaceae), popularly known as lain of lold, was collected on the campus of the Federal Rural University of Rio de Janeiro Campus Serop?dica RJ. Some chemical and biological activities of extracts of the last species were evaluated. Chromatographic fractionation of leaf and stem extracts from the Justicia wasshauseniana (Acanthaceae), from the leaf and stem of Tetrapterys acutifolia (Malpighiaceae), and from the leaves and bark of Lophanthera lactescens (Malpighiaceae) besides analysis of fractions by chromatographic and spectroscopic techniques led to the isolation and identification of constituents of different classes of special metabolites. including new alkaloids from J. wasshauseniana. From the leaves and stem of J. wasshauseniana were identified a triglyceride with the unsaturated acyl moiety, an unsaturated carboxylic acid, a mixture of steroids (?-Sitosterol, estigmasterol and campesterol) and glycosyl steroids (3-O-?-D-glucopyranosylsitosterol and 3-O-?-D-glucopyranosylstgmasterol), a disaccharide (?-D-glucopyranosyl-O-?-D-fructofuranoside (Sucrose) and the alkaloids acid (N-fenil-o-metileno-O-5)-3-hidroxi-5-carboxy??-lactam, and N(fenil-o-metileno-O-5)-3-hidroxi-5-(carboxilato de 2,3-dihidroxipropionila)-?-lactama), described for the first time in the literature. From the leaves and stem of T. acutifolia were identified a mixture of sitosterol, stigmasterol, 5,6-dihydro-sitosterol. and 5,6-dihydro-20-21,22-23,24-28,25-26-campesterol, ascorbic acid, in addition to sucrose and an ecdysteroid, 2S,3R,5R,9R,10R,13R,14S,17S,20S-2,3,14,20,24,25-hexahidroxicolest-7-en-6-ona (Pinatasterone). The extracts from the leaves and barks of L. lactescens, besides the mixture of sitosterol, stigmasterol and campesterol, was isolated the nortriterpene known as coreolidene. Besides to confirm the structure correction proposed in the literature of this nortriterpene, the absolute stereochemistry was defined as methyl 4R,5R,6R,7S,8S,9S,10S,13R,14S,15S,16R,17S,18R,21S,22S-friedelan-1,2-en-3-carboxy-24- 5- [1-acetoxy-ethylidene] -6,7,15,16-tetracetoxy-18-hydroxy-21,22-oxy-29-methylene-30-carboxylate. The structures were defined through analysis of IR, 1D and 2D NMR, mass spectra and circular dichroism besides some methyl and acetyl derivatives. The methanolic extracts from the stem and leaves of J. wasshausseniana and the methanolic extracts and fractions of the stem and leaves of T. acutilfolia were tested against the free radicals of DPPH. The extract from the stem of J. wasshausseniana was more active than leaf extract. The fraction of hexane from the leaves of T. acutilfolia did not present a good antioxidant activity, a greater activity was observed for the ethyl acetate fraction of stem and leaves of this plant. The pharmacological tests of the antinociceptive and anti-inflammatory potentials of the L. lactescens bark methanolic extract and the methanolic extract of leaves of J. wassahueniana were carried out, in which they showed positive results in the tested activities. / Este trabalho descreve o isolamento e determina??o estrutural de metab?litos especiais isolados de folhas e caule de J. wasshauseniana (Acanthaceae), vulgarmente conhecida como rabo de quati, que foi coletada no Munic?pio de Paracambi, RJ; folhas e caule de T. acutifolia, conhecida vulgarmente como cip?-ru?o, coletado no munic?pio de Barra do Pira?-RJ e L. lactescens (Malpighiaceae), conhecida vulgarmente como Chuva-de-Ouro, coletado no campus da Universidade Federal Rural do Rio de Janeiro Campus Serop?dica RJ. Realizaram-se testes de atividade biol?gica de extratos das duas ?ltimas esp?cies. O fracionamento cromatogr?fico dos extratos de folhas e caule de Justicia wasshauseniana (Acanthaceae), de folhas e caule de Tetrapterys acutif?lia (Malpighiaceae), de folhas e cascas de Lophanthera lactescens (Malpighiaceae) e an?lise das fra??es atrav?s de t?cnicas cromatogr?ficas e espectrosc?picas conduziu ao isolamento e identifica??o de constituintes de diferentes classes de metab?litos especiais. Das folhas e caule de J. wasshauseniana foram identificados um triglicer?deo com a unidade acila insaturada, um ?cido carbox?lico insaturado, uma mistura dos ester?ides (?-sitostesterol, estigmasterol e campesterol) e a mistura de esteroides glicosilados, 3-O-?-D-glicopiranosilsitosterol e o 3-O-?-D-glicopiranosilestigmasterol, um dissacar?deo, ?-D-glicopiranosil-?-D-frutofuranos?deo (sacarose) e os alcal?ides ?cido-(N-fenil-o-metileno-O-5)-3hidroxi-5-carboxi??-lactama e N(fenil-o-metileno-O-5)-3-hidroxi-5-(carboxilato de 2,3-dihidroxipropionila)-?-lactama) que est?o sendo descritos pela primeira vez na literatura. Dos extratos de folhas e caule de T. acutifolia foram isolados uma mistura dos esteroides, sitostesterol, estigmasterol, 5,6-diidro-sitosterol e 5,6-diidro-20-21,22-23,24-28,25-26-octaidro-campesterol, o ?cido asc?rbico, al?m da sacarose e o ecdisteroide 2S,3R,5R,9R,10R,13R,14S,17S,20S-2,3,14,20,24,25-hexahidroxicolest-7-en-6-ona (Pinatasterona), desta enona que foi convertido em 2,3,24,25-tetraacetato atrav?s de tratamento com anidrido ac?tico e piridina. Dos extratos de folhas e cascas de L. lactescens, al?m da mistura de esteroides sitoesterol, estigmasterol e campesterol, foi isolado o nor-triterpeno conhecido como correolideo que, al?m da confirma??o da corre??o da estrutura registrada na literatura foi proposta a estereoqu?mica absoluta, sendo, entretanto definida como 4R,5R,6R,7S,8S,9S,10S,13R,14S,15S,16R,17S,18R,21S,22S-friedelan-1,2-en-3-carboxi-24-O-metileno-5-[1-acetoxi-etilideno]-6,7,15,16-tetracetoxi-18-hidroxi-21,22-oxi-29-metileno-30-carboxilato de metila. As estruturas foram definidas atrav?s de an?lise de espectros de IV, RMN 1D e 2D, massas e dicro?smo circular e, em alguns casos da prepara??o de derivados. Os extratos metan?licos de caule e de folhas de J. wasshausseniana e os extratos metan?licos e fra??es do caule e folhas de T. acutilfolia foram testados contra os radicais livres de DPPH. O extrato do caule de J. wasshausseniana apresentou melhor atividade do que o extrato de folhas. A fra??o de hexano de folhas de T. acutilfolia n?o apresentou uma boa atividade antioxidante, observando-se uma maior atividade para a fra??o de acetato de etila de caule e folhas. Realizaram-se os testes farmacol?gicos do potencial antinociceptivo e anti-inflamat?rio do extrato metan?lico de cascas de L. lactescens e extrato metan?lico de folhas de J. wassahueniana, no qual apresentaram resultados positivos nas atividades testadas
16

Investiga??o Te?rica de Rea??es Unimoleculares da Formamida em Fase Gasosa. / Theoretical Investigation of Unimolecular Reaction of Formamide in the Gas Phase.

Berutti Neto, Renato 14 March 2012 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2018-03-15T14:04:44Z No. of bitstreams: 1 2012 - Renato Berutti Neto.pdf: 4059567 bytes, checksum: 6f8cfef981af15e4298a546d0c7563dc (MD5) / Made available in DSpace on 2018-03-15T14:04:44Z (GMT). No. of bitstreams: 1 2012 - Renato Berutti Neto.pdf: 4059567 bytes, checksum: 6f8cfef981af15e4298a546d0c7563dc (MD5) Previous issue date: 2012-03-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. / This work has been performed at the Laboratory of Chemical Kinetics, located in the Chemistry Department of Universidade Federal Rural do Rio de Janeiro, for the study of unimolecular reactions of formamide in gas phase and on the ground state: (1) CHONH2? CO + NH3 (2) CHONH2? H2 + HNCO and (3) CHONH2? HCO + NH2. Theoretical calculations including geometry optimizations and frequencies, have been performed at CASSCF level, with corrections at MRMP2 level for the electronic energy. The cc-pVDZ, cc and cc-pVTZ basis sets as well as the aug-cc-pVDZ have been used for comparative purposes. The unimolecular reactions were differently treated, depending on the specific topology of the potential energy surface. For the decompositions, corresponding saddle points have been located and the lowest energy paths have been calculated with the intrinsic reaction coordinate (IRC) method. The dissociation reaction has been described in terms of a scanning on the potential curve considering partial geometry optimizations of the fragments NH2 and HCO, keeping the CN distances frozen, those assumed as the internal reaction coordinate. Ab initio calculations were performed with the package GAMESS. The results show that the best description of the molecule has been obtained at CAS(10,9)/CCT level, yielding minimum deviations for the calculated molecular properties in relation to the experimental data available in the literature. The critical energies for the reactions of the decomposition have been determined, being (1): 77.60 kcal / mol and (2): 73.56 kcal / mol, both at level MRMP2/CAS(10,9)/CCT. For these results, it has been observed that the corrections MRMP2 are very important, bringing data calculated values very close to the literature values. From the analysis of the reaction pathways, it can be inferred that the dynamics of decomposition CHONH2 ? CO + NH3 is initiated by the torsional movement along the axis molecular by slightly rotating the fragment HCO in relation to the NH2, while the distance CN extends and the HC distance increases, with decreasing of HCN angle; the hydrogen atom bonds to the nitrogen atom and, with progressive increase of the distance CN, the fragments NH3 and CO are formed, achieving relaxed geometries. The decomposition CHONH2? HNCO + H2, by its turn, is initiated by increasing the distance HC at the HCO fragment, and further hydrogen abstraction of the atom at the NH2 fragment to form H2, which progressively separates from the HNCO, after the saddle point, generating the two products of this reaction. Dissociation is interpreted as the stretching of the CN bond, which promotes the separation of the NH2 and HCO fragments, whose geometries are relaxed along the curve of potential. The dissociation limit, determined at level MRMP2/CAS(10,9)/CCT is 91.52 kcal/mol. The canonical variational constant were calculated in the range of 300 - 2000K, being the values, in s-1, obtained at 1600K: (1) k = 5.62 x 103, (2) k = 1.07 x 103 and (3) k = 3.45. It follows that the channel (1) is privileged at a temperature of 1600K, and the decompositions are faster than the dissociation. / O presente trabalho foi realizado no Laborat?rio de Cin?tica, situado no Departamento de Qu?mica da Universidade Federal Rural do Rio de Janeiro, visando o estudo das Rea??es Unimoleculares da Formamida em Fase Gasosa e no Estado Fundamental: (1) CHONH2? CO + NH3, (2) CHONH2? HNCO + H2 e (3) CHONH2? HCO + NH2. C?lculos te?ricos, incluindo otimiza??es de geometria e frequ?ncias, foram procedidos em n?vel CASSCF com corre??es em n?vel MRMP2 para a energia eletr?nica. Bases cc-pVDZ e cc-pVTZ, assim como aug-ccpVDZ foram utilizados para fins comparativos. As rea??es unimoleculares foram tratadas diferentemente, dependendo da topologia espec?fica da superf?cie de energia potencial. Para as decomposi??es, pontos de sela correspondentes foram localizados e caminhos de menor energia foram calculados com o m?todo da coordenada de rea??o intr?nseca (IRC). A rea??o de dissocia??o foi descrita a partir do levantamento da curva de potencial considerando otimiza??es parciais de geometria dos fragmentos NH2 e HCO, mantendo fixas as dist?ncias CN, coordenada interna esta, assumida como a coordenada de rea??o. Os c?lculos ab initio foram realizados com o pacote GAMESS. Os resultados mostram que a melhor descri??o da mol?cula de formamida foi obtida em n?vel CAS(10,9)/CCT, promovendo menores desvios das propriedades moleculares calculadas em rela??o as experimentais dispon?veis na literatura. As energias cr?ticas para as rea??es de decomposi??o foram determinadas, sendo (1): 77,60kcal/mol e (2): 73,56 kcal/mol, ambas em n?vel MRMP2/CAS(10,9)/CCT. Para esses resultados, observou-se que as corre??es MRMP2 foram muito importantes, trazendo esses dados calculados a valores muito pr?ximos aos recomendados na literatura. A partir da an?lise dos caminhos de rea??o, pode-se inferir que a din?mica da decomposi??o CHONH2? CO + NH3 ? iniciada pelo movimento de tor??o ao longo do eixo molecular, fazendo girar levemente o fragmento NH2 em rela??o ao HCO, ao mesmo tempo em que o eixo CN se alonga e a dist?ncia HC aumenta, com a diminui??o do ?ngulo HCN, o ?tomo de hidrog?nio se liga ao nitrog?nio e, a partir do aumento progressivo da dist?ncia CN, os fragmentos NH3 e CO se formam, tendo lentamente suas geometrias relaxadas. J? a decomposi??o CHONH2? HNCO + H2 ? iniciada pelo aumento da dist?ncia HC no radical HCO e posterior abstra??o de um dos ?tomos de hidrog?nio do fragmento NH2 para a forma??o de H2, que se distancia progressivamente, ap?s a regi?o do ponto de sela, do fragmento HNCO, gerando os dois produtos desta rea??o. A dissocia??o, interpretada como o estiramento da liga??o CN, promove a separa??o dos fragmentos NH2 e HCO, cujas geometrias s?o otimizadas ao longo da curva de potencial. O limite de dissocia??o, calculado em n?vel MRMP2/CAS(10,9)/CCT foi determinado como 91,52 kcal/mol. As constantes variacionais can?nicas foram calculadas na faixa de 300 - 2000K com o programa kcvt, sendo os valores, em s-1, obtidos a 1600K: (1) k = 5,62 x 103, (2) k = 1,07 x 103 e (3) k = 3,45. Conclui-se que o canal (1) ? privilegiado na temperatura de 1600K, e que as decomposi??es s?o mais r?pidas que a dissocia??o.
17

S?ntese e avalia??o da atividade anticorrosiva d enamino?steres frente ao a?o carbono AISI 1020 em meio ?cido / Synthesis and evaluation of the anti-corrosive activity of enantiomers against AISI 1020 carbon steel in acidic medium

Carlos, Mariana Falc?o Lopes Princisval 16 August 2017 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-04-11T16:46:38Z No. of bitstreams: 1 2017 - Mariana Falc?o Lopes Princisval Carlos.pdf: 3027874 bytes, checksum: f7dd2c459e8918f917f701198c97f955 (MD5) / Made available in DSpace on 2018-04-11T16:46:38Z (GMT). No. of bitstreams: 1 2017 - Mariana Falc?o Lopes Princisval Carlos.pdf: 3027874 bytes, checksum: f7dd2c459e8918f917f701198c97f955 (MD5) Previous issue date: 2017-08-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In this work, seven enaminoesters were synthesized, divided into three series depending on the starting amine, the series A is derived from phenethylamine, the series B of aniline and, finally, the series C derived from benzylamine. The synthesis occurred in two ways, the first being through the reaction of the ethyl acetoacetate in the presence of the corresponding amine in ethanol as solvent in the presence of p-toluenesulfonic acid and the second the amine in the presence of triethylamine and methanol as solvent, both in magnetic stirring at room temperature. The compounds were obtained as oil, with a high purity, and for some compounds separation via flash chromatography in ethyl acetate / hexane was required, yields ranging from 70-93%. The compounds were characterized by spectroscopic techniques such as Infrared and Nuclear Magnetic Resonance 1H and 13C, in addition to the refractive index. Six of the seven compounds synthesized were evaluated using electrochemical techniques of Impedance Spectroscopy Electrochemistry, Potentiodynamic Polarization and Resistance to Linear Polarization and the mass loss technique, as to the action as inhibitors of corrosion against AISI 1020 carbon steel in 0.5 mol L-1 HCl. The Molecular Modeling technique was used to better visualize the structures of the synthesized enaminoesters and, later, correlation of the inhibition efficiencies found. The theoretical parameters such as the energy of the orbitals of symmetrical boundaries and dipole moment with the results corrosion efficiency were also evaluated. In general, the enaminoesters showed good corrosion efficiency, excess by the compound derived from hydroxylaniline. All presented corrosion inhibition efficiency with mixed inhibitor characteristics. However, the compounds that did not present substituents and those that contain electron donor group (OCH3) stood out as inhibitors, highlighting the compound EN1, which presented efficiency of 92% of inhibition of the corrosion by the technique of Resistance to Polarization Potentiodynamics and 98% by the technique of mass loss after 24h of immersion. The efficiency was shown to be dependent on the concentration in the synthesized compounds, that is, the corrosion inhibition efficiency increases with XXIII increasing inhibitor concentration, and that the adsorption phenomena of the compounds studied obey the Langmuir isotherm. Thus, the synthesized, especially the not substituted, enaminoesters can be considered as promising corrosion inhibiting agents for acidic AISI 1020 carbon steel. / Nesta disserta??o, foram sintetizados sete enamino?steres, divididos em tr?s s?ries de acordo com a amina de partida, sendo a s?rie A derivada da fenetilamina, a s?rie B da anilina e, por ?ltimo, a s?rie C derivada da benzilamina. A s?ntese ocorreu de duas formas, sendo a primeira atrav?s da rea??o do acetoacetato de etila na presen?a da amina correspondente em etanol como solvente, na presen?a de ?cido p-toluenossulf?nico e, a segunda, a amina na presen?a de trietilamina e metanol como solvente, ambas em agita??o magn?tica ? temperatura ambiente. Os compostos foram obtidos em forma de ?leo, com alto grau de pureza, sendo necess?ria para alguns compostos a separa??o via cromatografia flash em acetato de etila/hexano, os rendimentos variaram na faixa de 70-93%. Os compostos foram caracterizados por t?cnicas espectrosc?picas de Infravermelho e Resson?ncia Magn?tica Nuclear 1H e 13C, al?m de ?ndice de refra??o. Seis dos sete compostos sintetizados foram avaliados por t?cnicas eletroqu?micas de Espectroscopia de Imped?ncia Eletroqu?mica, Polariza??o Potenciodin?mica e Resist?ncia a Polariza??o Linear e, por ensaio de perda de massa, quanto ? a??o como inibidores de corros?o frente a a?o carbono AISI 1020 em solu??o de HCl 0,5 mol L-1 . Modelagem Molecular foi utilizada para melhor visualiza??o das estruturas moleculares dos enamino?steres sintetizados e, posterior, correla??o das efici?ncias de inibi??o encontradas. Os par?metros te?ricos como a energia dos orbitais de fronteiras sim?tricos e momento dipolar foram calculados e, apenas os valores de momento dipolar correlacionaram com os resultados experimentais da efici?ncia anticorrosiva. De forma geral, os enamino?steres apresentaram boa efici?ncia anticorrosiva, com exce??o do composto derivado da hidr?xianilina (EN6). Todos apresentaram efici?ncia de inibi??o ? corros?o com caracter?sticas de inibidores mistos. Por?m, os compostos que n?o apresentaram substituintes e os que cont?m grupo doador de el?trons (OCH3) se destacaram como inibidores mais eficientes, dando destaque ao composto EN1, que apresentou efici?ncia de 92% de inibi??o da corros?o, pela t?cnica de Resist?ncia a Polariza??o Potenciodin?mica e 98% pela t?cnica de perda de massa ap?s 24 h de imers?o. XXI A efici?ncia se mostrou dependente da concentra??o nos compostos sintetizados, ou seja, a efici?ncia de inibi??o da corros?o aumentou com o aumento da concentra??o dos inibidores. Os fen?menos de adsor??o dos compostos estudados, apenas o EN1 obedece ? isoterma de Langmuir e os restantes a Langmuir modificada. Com isso, os enamino?steres sintetizados, especialmente os n?o substitu?dos, podem ser considerados como promissores agentes inibidores da corros?o para o a?o carbono AISI 1020 em meio ?cido.
18

Produ??o de amilase por Bacillus amyloliquefaciens utilizando torta de maca?ba (Acrocomia aculeata) e farinha de pupunha (Bactris gasipaes) como substratos / Production of amylase by Bacillus amyloliquefaciens using macauba cake (Acrocomia aculeata) and peach palm flour (Bactris gasipaes) as substrates

Silva, Isadora Ferreira da 24 July 2012 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:03:28Z No. of bitstreams: 5 isadora.pdf: 1113191 bytes, checksum: d7fa6c19b7906bcd17915b6d1233d2e6 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T09:25:04Z (GMT) No. of bitstreams: 5 isadora.pdf: 1113191 bytes, checksum: d7fa6c19b7906bcd17915b6d1233d2e6 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T09:25:04Z (GMT). No. of bitstreams: 5 isadora.pdf: 1113191 bytes, checksum: d7fa6c19b7906bcd17915b6d1233d2e6 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-21 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Amilases s?o enzimas que atuam no rompimento das liga??es glicos?dicas presentes nas cadeias de amilose e amilopectina. As amilases possuem aplica??es em diversas ?reas tais como: ind?stria de papel e celulose, ind?stria t?xtil, ind?stria de detergentes e produtos de limpeza, ind?stria qu?mica e farmac?utica, na produ??o de vitaminas e antibi?ticos. Embora as amilases sejam encontradas em plantas, animais e micro-organismos, as enzimas microbianas geralmente atendem de maneira satisfat?ria ? demanda industrial. As enzimas microbianas podem ser obtidas por meio de processos fermentativos, podendo ser obtidas tanto por cultivo superficial como por cultivos submersos. O presente trabalho teve por objetivo avaliar a produ??o de enzimas amilol?ticas por fermenta??o submersa utilizando Bacillus amyloliquefaciens ATCC 23350 e coprodutos da cadeia produtiva do biodiesel como substrato. A capacidade da produ??o das enzimas amilol?ticas foi testada utilizando como substratos diferentes coprodutos, sendo esses: torta de maca?ba, torta de dend?, farinha de pupunha, torta de mamona e torta de tremo?o. A torta de maca?ba e farinha de pupunha foram os substratos que demonstraram maior capacidade de produ??o das enzimas amilol?ticas, sendo os coprodutos selecionados para a etapa de otimiza??o da produ??o das enzimas. Diferentes condi??es de processo foram otimizadas com intuito de obter o m?ximo rendimento da produ??o de amilases, atrav?s do emprego de delineamentos experimentais aplicados ? Metodologia de Superf?cie de Resposta. Os processos fermentativos deste trabalho foram realizados ? temperatura de 37?C, 120 rpm de agita??o, utilizando solu??o de sais para suplementa??o do meio. As vari?veis pH, raz?o s?lido-l?quido (S/L) (% m/v) e concentra??o de NH4NO3 (gL-1) foram estudadas. As dosagens das atividades enzim?ticas foram realizadas em tempos de fermenta??o de 12, 24, 36, 48 e 72 horas. A m?xima produ??o das amilases foi alcan?ada com 24 horas de fermenta??o, S/L de 12% e pH 7,0, obtendo valores de 3.393 U.mL-1 com a farinha de pupunha e 196 U.mL-1 com a torta de maca?ba como substratos. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT Amylases are enzymes that act in the rupture of glycosidic bonds present in the chains of amylose and amylopectin. Amylases have applications in diverse areas such as pulp and paper industry, textiles, laundry detergents and cleaning products, chemical and pharmaceutical industry, production of vitamins and antibiotics. Although the amylases are found in plants, animals and micro-organisms, microbial enzymes generally meet satisfactorily the industrial demand. The microbial enzymes can be obtained by fermentative procedures, which may be obtained by cultivation both surface and submerged cultivation of micro-organisms. This study aimed to evaluate the production of amylolytic enzymes by submerged fermentation using Bacillus amyloliquefaciens ATCC 23350, and co-products from biodiesel production chain as substrates. The capacity of the production of amylolytic enzymes was tested using different substrates such as co-products, these being: macauba cake, palm kernel cake, peach palm flour, castor bean and lupine cake. The peach palm flour and macauba cake were the substrates which show greater production capacity of amylolytic enzymes, and co-products selected for the optimization step of enzyme production. Different process conditions were optimized with the aim of obtaining the maximum yield of amylases, through the use of experimental designs applied to the Response Surface Methodology. The fermentation process of this work was performed at 37?C, 120 rpm agitation, using salt solution for supplementation of the medium. The pH, liquid-solid ratio (S/L) (% w/v) and concentration of NH4NO3 (gl-1) were studied. The measurements of enzyme activities were carried out in fermentation times of 12, 24, 36, 48 and 72 hours. Maximum production of amylase was achieved with 24 hours of fermentation, S/L of 12% and pH 7.0 to obtain values of 3.393 U.mL-1 with peach palm flour and 196 U.mL-1 with maca?ba cake as substrate.
19

Avalia??o da torta de dend? (Elaeis guineensis) para produ??o de bioetanol de segunda gera??o / Evaluation of palm cake (Elaeis guineensis) for production of second generation ethanol

Ferreira, Crisley Mara de Azevedo 22 February 2013 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:03:28Z No. of bitstreams: 5 crisley.pdf: 2081607 bytes, checksum: 90ca0fb9cd507118e713cc82f093637a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T09:27:10Z (GMT) No. of bitstreams: 5 crisley.pdf: 2081607 bytes, checksum: 90ca0fb9cd507118e713cc82f093637a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T09:27:10Z (GMT). No. of bitstreams: 5 crisley.pdf: 2081607 bytes, checksum: 90ca0fb9cd507118e713cc82f093637a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-12-17 / A busca por energias alternativas, sustent?veis e economicamente vi?veis, colocou em destaque o uso dos biocombust?veis. Os estudos recentes apontam o uso de biomassas residuais como candidatas potenciais para produ??o de bioenergia. Nesse contexto, a presente disserta??o teve por objetivo ava-liar a torta de dend? como insumo para produ??o de etanol de segunda gera??o por meio de estudos que envolveram etapas de pr?-tratamento ?cido e alcalino, sacarifica??o e fermenta??o. Inicialmente foi determinada a composi??o centesimal da torta de dend?, indicando a presen?a de 53,2% de car-boidratos totais, dos quais 32% referente a fra??o de celulose. Para otimiza??o do pr?-tratamento ?cido foi aplicado um Planejamento Fatorial atrav?s de delineamento composto central rotacional. O programa STATISTICA Vers?o 8.0 (Statsoft Inc., Tulsa,) foi utilizado para an?lise dos dados. O pr?-tratamento com ?cido sulf?rico dilu?do resultou na remo??o de pelo menos 82% da hemicelulose presente na torta de dend?. O pr?-tratamento alcalino subsequente foi capaz de remover pelo menos 72% da lignina da biomassa, um interferente do processo fermentativo. Na sequ?ncia o processo de sacarifica??o foi otimizado com o uso de delineamento composto central rotacional com 3 fatores, 4 pontos centrais e 6 pontos axiais, onde foram avaliadas a concentra??o de celulases, a raz?o s?lido-l?quido e o tempo. O hidrolisado enzim?tico obtido em condi??o otimizada, com 80% de convers?o da celulose a a??cares redutores, foi submetido ? fermenta??o com Saccharomyces cerevisiae apre-sentando um YP/S de 0,49 com 5,4%(v/v) de ?lcool no mosto fermentado. Os dados obtidos indicaram que a torta de dend? avaliada apresenta elevado potencial para produ??o de bioetanol de segunda gera??o. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The search for alternative energies, sustainable and economically viable, highlighted the use of biofuels. Recent studies indicate the use of residual biomass as potential candidates for bioenergy production. In this context, the present dissertation aimed at evaluating the palm cake as a feedstock for the production of second generation ethanol through studies involving acid and alkaline pretreatment steps, saccharification and fermentation. Initially it was determined the chemical composition of palm cake, indicating the presence of 53.2% of total carbohydrates, of which 32% related to cellulose. To optimize the pretreatment was applied a Factorial Design by central composite rotational design. The program STATISTICA version 8.0 (Statsoft Inc., Tulsa,) was used for data analysis. Pretreatment with dilute sulfuric acid resulted in the removal of at least 82% of the hemicellulose present in palm cake. The subsequent alkaline pretreatment was able to remove at least 72% of the lignin from the biomass, an interfering of fermentation. Further the saccharification process was optimized by the use of central composite design with three factors, fourth central points and six axial points, evaluating the concentration of cellulase, the solid-liquid ratio and the time. The enzymatic hydrolyzate obtained under optimized conditions with 80% conversion of cellulose to sugars was subjected to fermentation with Saccharomyces cerevisiae showing an YP/S of 0.49 based on 5.4% (v/v) of alcohol in the fermented must. The data indicated that the palm kernel cake evaluated presents high potential for production of second generation bioethanol.
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Desenvolvimento e aplica??o do material comp?sito HRP/PANI/PEG-MWCNT como plataforma para detec??o de per?xido de hidrog?nio a baixo potencial / Development and application of HRP/PANI/PEG-MWCNT composite material as a platform for hydrogen peroxide detection with high sensitivity at low potential

Silva, Jussara Vieira da 26 February 2013 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:44Z No. of bitstreams: 5 jus.pdf: 3394180 bytes, checksum: 71d0ff7761a41fcaa36b37cfba79f687 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:26:30Z (GMT) No. of bitstreams: 5 jus.pdf: 3394180 bytes, checksum: 71d0ff7761a41fcaa36b37cfba79f687 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:26:30Z (GMT). No. of bitstreams: 5 jus.pdf: 3394180 bytes, checksum: 71d0ff7761a41fcaa36b37cfba79f687 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-12-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Atualmente os nanotubos de carbono (NTC) representam um importante grupo de nanomateriais com atrativas propriedades qu?micas, eletr?nicas e mec?nicas. Estes materiais podem ser combinados a pol?meros, de maneira a moldar as propriedades f?sicas desses compostos (nanotubos-pol?mero), aumentando sua condutividade el?trica, estabilidade qu?mica e resist?ncia mec?nica. O presente trabalho apresenta o desenvolvimentoum material comp?sitonanoestruturado ? base de polianilina (PANI) e nanotubos de carbono de paredes m?ltiplas(MWCNT), para tal, os NTC foram funcionalizados com agrupamentos amina (PEG-NH2). A inser??o do grupamento amina junto aos NTC (PEG-MWCNT) foi confirmada atrav?s da caracteriza??o deste material utilizando as t?cnicas de Microscopia Eletr?nica de Varredura (MEV), Espectroscopia de infravermelho com transformada de fourrier(FT-IR) e Espectroscopia de Energia dispersiva de Raios-X. Foi produzido um eletrodo modificado atrav?s da polimeriza??o do mon?mero anilinaem presen?a dos NTC funcionalizados denominado PANI/PEG-MWCNT. Foram analisadas as propriedades do comp?sito PANI/PEG-MWCNT pelas t?cnicas de Voltametria c?clica e Espectroscopia de Imped?ncia Eletroqu?mica, atrav?s das quais foi verificado que a presen?a combinada dos NTC e da PANI favorece forma??o de um material comp?sito com propriedades sin?rgicas. Al?m disso, atrav?s da Microbalan?a Eletroqu?mica de Cristal de Quartzo pode-se constatarque a dopagem da PANI com PEG-MWCNT favorece o transporte de pr?tons significativamente. Atrav?s da t?cnica de microscopia eletroqu?mica de varredura foi poss?vel evidenciar que existem mais s?tios ativos na superf?cie do filme de PANI/PEG-MWCNT do que na superf?cie da PANI devido ? incorpora??o uniforme dos MWCNT. Finalmente, o eletrodo modificado com o material comp?sito foi utilizado como plataforma no desenvolvimento de um biossensor enzim?tico, pela imobiliza??o da enzima HRP (HRP/PANI/PEG-MWCNT). O biossensor HRP/PANI/PEG-MWCNT apresentou um ?timo suporte para aredu??o de per?xido de hidrog?nio a baixo potencial (-100 mV) vs Ag/AgCl, bem como alta sensibilidade (1.01) ?Acm-2 ?M?1e baixo limite de detec??o de 0,5 ?M L-1. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT Currently carbon nanotubes (NTC) represent an important group of nanomaterials with attractive properties (chemical, electronic and mechanical). These materials can be combined with polymers in order to shape their physical properties of these compounds (nanotube-polymer), increasing its electrical conductivity, chemical stability and mechanical strength. In fact, this study shows the production of a nanostructured composite material based on polyaniline (PANI) and carbon nanotubes multi-walled (MWCNT), for this, the NTC were functionalized with amine groups (PEG-NH2). The insertion of the amine grouping together to NTC (MWCNT-PEG) was confirmed by the characterization of this material using the techniques of Scanning Electron Microscopy (SEM) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-Ray. A modified electrode was produced through polymerization in the presence of PANI called NTC functionalized PANI/PEG-MWCNT. The properties of the composite PANI/MWCNT-PEG were examined by cyclic voltammetry and Electrochemical Impedance Spectroscopy, it was found that the combined presence of the NTC and polyaniline in the modified electrode provides a formation of a composite material with synergistic properties. Furthermore, through the technique of Electrochemical Microbalance Quartz Crystal can be seen that doping of PANI with PEG-MWCNT facilitates significantly the transport of protons. Finally, through the technique of scanning electrochemical microscopy was possible to show that there are more active sites on the surface of the film of PANI / MWCNT-PEG than on the surface of PANI due to the incorporation of MWCNT uniform. Lastly, the modified electrode composite material was used as a support for a biosensor for immobilization of the enzyme HRP (HRP/PANI/PEG-MWCNT). The biosensor HRP/PANI/MWCNT-PEG showed a great support for the reduction of hydrogen peroxide at a low potential (-100mv) vs Ag / AgCl as well as high sensitivity (1.01) ?A cm-2 mM-1 and low detection limit 0.5 ?m.

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