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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

Beneficiamento, caracteriza??o e pilariza??o de argilas naturais brasileiras

Parodia, Anderson 22 July 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-03T19:34:52Z No. of bitstreams: 1 AndersonParodia_DISSERT.pdf: 4327470 bytes, checksum: 6b271a416195c9528f27a2f60bbd49af (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-04T22:47:31Z (GMT) No. of bitstreams: 1 AndersonParodia_DISSERT.pdf: 4327470 bytes, checksum: 6b271a416195c9528f27a2f60bbd49af (MD5) / Made available in DSpace on 2017-04-04T22:47:31Z (GMT). No. of bitstreams: 1 AndersonParodia_DISSERT.pdf: 4327470 bytes, checksum: 6b271a416195c9528f27a2f60bbd49af (MD5) Previous issue date: 2016-07-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Quatro argilas provenientes de jazidas localizadas no norte do estado da Para?ba, Brasil, foram beneficiadas com o intuito de diminuir a quantidade de impurezas presentes naturalmente nestes materiais. Posteriormente, estas argilas foram caracterizadas juntamente com uma amostra de argila natural comercial e submetidas ao procedimento de pilariza??o com polihidr?xidos de alum?nio. Atrav?s da difratometria de raios X observou-se que as amostras beneficiadas (CN Clara, CN Cinza, Bofe e FCN) apresentaram um espa?amento basal de aproximadamente 1,5 nm, enquanto a amostra natural comercial apresentou um valor aproximado de 1,3 nm, ap?s a pilariza??o estes valores foram de ~1,7 nm para amostras beneficiadas e de ~1,8 nm para a amostra comercial. A amostra Bofe aprestou um valor de 126 m2/g de ?rea espec?fica, sendo este o maior valor encontrado entre as amostras naturais, a amostra natural comercial apresentou um valor de 27 m2/g sendo este o menor valor. Ap?s a pilariza??o a amostra que apresentou o maior valor de ?rea espec?fica foi a amostra AP01 (pilarizada a partir da amostra natural comercial), com um valor de 248 m2/g enquanto a amostra AP05 (pilarizada a partir da amostra FCN) apresentou o menor valor sendo este de 177 m2/g. Dessa maneira v?-se que a determina??o das caracter?sticas das argilas naturais e sua origem influenciam os resultados obtidos atrav?s do procedimento de pilariza??o. / Four clays from deposits located in the northern state of Paraiba, Brazil, were processed in order to decrease the amount of impurities naturally presented in these materials. Later these materials were characterized along with a commercial natural clay sample and subjected to a pillaring procedure with aluminum polihidroxide. By X-ray diffraction, it was noted that the benefit samples (CN Clara, CN Cinza, Bofe and FCN) showed a basal spacing of approximately 1.5 nm, while the natural commercial sample showed a value of approximately 1.3 nm, after pillaring these values were ~ 1.7 nm for the benefits sample and ~ 1.8 nm for the commercial sample. The sample Bofe showed a value of 126 m2/g of specific area, which is the highest value found among natural samples, commercial natural sample showed a value of 27 m2/g being the smallest value. After pillarization the sample that showed the highest specific area was the AP01 sample (pillared from commercial natural sample), with a value of 248 m2/g while the AP05 sample (pillared from FCN sample) had the lowest value being 177 m2/g. Thus it is seen that the determination of the characteristics of natural clays and its origin influence the results obtained through the pillaring procedure.
2

CaracterizaÃÃo e obtenÃÃo de compostos fenÃlicos presentes no efluente do processamento da casca de coco verde. / Characterization and achievement of phenolic compounds present in the effluent from the processing of green coconut shell.

Ana Cristina de Abreu Siqueira 04 July 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The high consumption of green coconut water has generated increasing in the residue caused by improper discard of green coconut rind in Brazilian coast. To reduce this problem, Embrapa Tropical Agroindustry installed a Pilot Unit processing of green coconut rind to obtain fiber and powder, which ends up generating an effluent with high organic load, high sugar and polyphenols content and is called liquid of the rind of green coconut (LCCV). In order to reduce polyphenols and sugar content, alcoholic fermentation was carried out in the effluent, with 5 and 7.5% (w/v) of Saccharomyces cerevisiae, another fermentation with 5% (w/v) of S. cerevisiae wich was reused in subsequent fermentations and also polyphenols removal by adsorption using aluminum pillared clay. Phenolic compounds present in LCCV were characterized by nuclear magnetic resonance of hydrogen and liquid chromatography with mass spectrometry, it was possible to identify chlorogenic acid, isomers of caffeoyl shikimic acid, including 5-O-caffeoylshikimic acid, which is the major phenolic compound of LCCV and also, ferulic acid. LCCV total polyphenols levels were reduced by fermentation of 7769.1 mg/L to 3808.6 mg/L in the fermentation with 5% (w/v) yeast and 2892.4 mg/L in the fermentation 7,5% (w/v) yeast. In the fermentation with reuse of yeast, the reduction in polyphenols content ranged of 4084.7 to 5853.5 mg/L. The fermentation was efficient in reducing the polyphenols levels, in addition its efficacy to consume the sugars, glucose and fructose, present in LCCV. / O consumo de Ãgua de coco verde tem gerado um aumento nos resÃduos provocado pelo descarte inadequado da casca de coco verde no litoral brasileiro. A fim de minimizar esse problema, a Embrapa AgroindÃstria Tropical instalou uma unidade piloto de beneficiamento da casca de coco verde para obtenÃÃo de fibra e pÃ, o que acaba gerando um efluente com carga orgÃnica elevada, alto teor de aÃÃcar e de polifenÃis e à denominado de lÃquido da casca de coco verde (LCCV). A fim de se reduzir o teor de polifenÃis totais, foi realizada uma fermentaÃÃo alcoÃlica do efluente, com 5 e 7,5% (p/v) de Saccharomyces cerevisiae, com 5% (p/v) de S. cerevisiae que foi reutilizada fermentaÃÃes posteriores, alÃm da remoÃÃo por adsorÃÃo de polifenÃis do LCCV utilizando argila pilarizada de alumÃnio. Os compostos fenÃlicos presentes no LCCV foram caracterizados atravÃs de ressonÃncia magnÃtica nuclear de hidrogÃnio e cromatografia lÃquida acoplada à espectrometria de massa, onde foi possÃvel identificar o Ãcido clorogÃnico, isÃmeros do Ãcido cafeoil chiquÃmico, entre eles o Ãcido 5-O-cafeoil chiquÃmico, que à o composto fenÃlico majoritÃrio do LCCV e Ãcido ferÃlico. A fermentaÃÃo reduziu os teores de polifenÃis totais do LCCV, passando de 7769,1 mg/L a 3808,6 mg/L com a fermentaÃÃo com 5% (p/v) de levedura e para 2892,4 mg/L com a fermentaÃÃo com 7,5% (p/v) de levedura. Para a fermentaÃÃo com reutilizaÃÃo de levedura, a reduÃÃo na concentraÃÃo de polifenÃis variou de 4084,7 a 5853,5 mg/L. A fermentaÃÃo foi eficiente na reduÃÃo dos teores dos polifenÃis e no consumo dos aÃÃcares glicose e frutose presentes no LCCV.

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