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.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-09-28T12:19:16Z No. of bitstreams: 1 2014 - Mara Alexandre da Silva.pdf: 458810 bytes, checksum: 70a72dfd6d35926572affcb5392ec6f7 (MD5) / Made available in DSpace on 2017-09-28T12:19:16Z (GMT). No. of bitstreams: 1 2014 - Mara Alexandre da Silva.pdf: 458810 bytes, checksum: 70a72dfd6d35926572affcb5392ec6f7 (MD5) Previous issue date: 2014-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Organic production is an alternative for family farmers where practices to reduce costs and to preserve natural resources can add value to the product and improve quality of life. The weeds can cause losses in crops, by reduction of income, increase in pests and diseases, non uniformity in maturity and difficulties for harvesting. The objective of this study was to evaluate the performance of common bean cultivars (Phaseolus vulgaris) at different sowing densities regarding the incidence of weeds in organic production system. Two field experiments were conducted in the Agroecological Production Integrated System of 47 km in Serop?dica-RJ, in the years 2013 and 2014, in a randomized block design with four replications. In 2013 a 4x3 factorial was used, combining four cultivars (Ouro Negro, Manteig?o, Radiante and Apor?) and three densities (8, 13 and 18 plants m-1 linear). In 2014 a 2x3 factorial was used, between two cultivars (Manteig?o and Ouro Negro) and three treatments (13 plants m-1 with manual cleaning of weeds, 13 and 18 plants m-1 without cleaning). To obtain the desired plant population, 50% more seeds were sown in each treatment and plants were thinned 15 days after. Sampling was carried out at the flowering stage to assess biomass and nodulation of bean and biomass of weeds, and at physiological maturity to evaluate grain yield. In 2013, the largest shoot and root dry mass and number of nodules per plant occurred in the density of 8 plant m-1. Increased planting density reduced the number of pods per plant, with no effect of density on grain yield. The lower biomass of weeds was observed at densities of 13 and 18 plant m-1, and also for cutivars Manteig?o and Ouro Negro. In 2014, treatment with 13 plants m-1 with cleaning showed greater dry mass of shoots and roots per plant. At flowering, treatment with 13 plants m-1 showed higher dry matter and number of weeds. The cultivar Ouro Negro showed higher grain yield at density of 13 plants m-1 with cleaning, followed by 18 plants m-1, with no differences between treatments for cultivar Manteig?o. The treatment with 18 plants m-1 showed lower mass of weeds at bean flowering, similar to the treatment with 13 plants m-1 with cleaning. Plots with cultivar Manteig?o had the highest dry matter of weeds in the three density treatments. Grain yield did not differ significantly among cultivars, ranging in 2013 from 1310 kg ha-1 for Apor? and 1409 kg ha-1 for Manteig?o, and in 2014 of 1298 and 1419 kg ha-1 for Manteig?o and Ouro Negro. It is concluded that increasing plant density reduced the incidence of weeds and did not affect grain yield. It was also carried out a field trial in 2013 in family agricultural establishment in the city of Teresopolis-RJ, in order to encourage the cultivation of special beans and to experience economic and social strategies of reproduction. The experiment had a 4x2 factorial with four replications, using four cultivars (Apor?, Manteig?o, Radiante and Valente) and two treatments (with and without commercial inoculant with rhizobia). Grain yield of the four cultivars did not differ between the treatments in the absence and presence of seed inoculation with rhizobia / A produ??o org?nica constitui uma alternativa para a agricultura familiar, onde pr?ticas para diminuir os custos de produ??o e preserva??o dos recursos naturais agregariam valor ao produto e qualidade de vida. As plantas espont?neas podem causar perdas em cultivos, pela redu??o do rendimento, aumento de pragas e doen?as, desuniformidade na matura??o e dificuldades na colheita. O objetivo deste trabalho foi avaliar o desempenho de cultivares de feijoeiro comum (Phaseolus vulgaris) em diferentes densidades de semeadura, com rela??o ? incid?ncia de plantas espont?neas em sistema org?nico de produ??o. Foram conduzidos dois experimentos de campo no Sistema Integrado de Produ??o Agroecol?gica do km 47, em Serop?dica-RJ, nos anos de 2013 e 2014, em blocos ao acaso com quatro repeti??es. Em 2013 foi utilizado esquema fatorial 4x3, combinando quatro cultivares (Ouro Negro, Manteig?o, Radiante e Apor?) e tr?s densidades (8, 13 e 18 plantas m-1 linear) e em 2014 utilizou-se esquema fatorial 2x3, entre duas cultivares (Manteig?o e Ouro Negro) e tr?s tratamentos (densidade de 13 plantas m-1 com limpeza manual de plantas espont?neas, densidades de 13 e 18 plantas m-1 sem limpeza). Para obten??o da popula??o desejada, foram semeadas 50% mais sementes em cada tratamento, e 15 dias ap?s realizou-se desbaste. Foram efetuadas amostragens no est?dio de flora??o para avalia??o de biomassa e nodula??o do feijoeiro e da biomassa de plantas espont?neas, e na matura??o fisiol?gica para avalia??o do rendimento. Em 2013, a maior massa seca de parte a?rea e raiz e n?mero de n?dulos por planta ocorreu na densidade de 8 plantas m-1. O aumento da densidade de plantio reduziu o n?mero de vagens por planta, sem efeito da densidade na produtividade de gr?os. A menor massa de plantas espont?neas foi observada nas densidades de 13 e 18 plantas m-1, e com as cultivares Manteig?o e Ouro Negro. Em 2014, o tratamento com 13 plantas m-1 com limpeza apresentou maior massa seca de parte a?rea e raiz por planta. Na flora??o, o tratamento com 13 plantas m-1 sem limpeza apresentou maior massa seca e n?mero de espont?neas. A cultivar Ouro Negro apresentou maior produ??o de gr?os no tratamento de 13 plantas m-1 com limpeza, seguida por 18 plantas m-1, sem diferen?as entre tratamentos na cultivar Manteig?o. O tratamento com 18 plantas m-1 apresentou menor massa de espont?neas na flora??o do feijoeiro, similar a 13 plantas m- 1 com limpeza. A cultivar Manteig?o apresentou maior massa de espont?neas nos tr?s tratamentos. A produ??o de gr?os n?o diferiu significativamente entre as cultivares, variando em 2013 entre 1310 kg ha-1 para Apor? e 1409 kg ha-1 para Manteig?o, e em 2014 com 1298 e 1419 kg ha-1 para Manteig?o e Ouro Negro. Conclui-se que o aumento da densidade de plantio reduziu a incid?ncia de plantas espont?neas e n?o afetou a produtividade de gr?os do feijoeiro. Foi tamb?m conduzido um experimento de campo em 2013 em estabelecimento agr?cola familiar no munic?pio de Teres?polis-RJ, com o objetivo de incentivar o cultivo de feij?es especiais e vivenciar estrat?gias de reprodu??o econ?mica e social. O experimento tinha esquema fatorial 4x2 com quatro repeti??es, entre quatro cultivares (Apor?, Manteig?o, Radiante e Valente) e dois tratamentos (com e sem uso de inoculante comercial de riz?bio). A produ??o de gr?os das quatro cultivares n?o diferiu entre os tratamentos na aus?ncia e na presen?a de inocula??o de sementes com riz?bio.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-11T20:09:52Z No. of bitstreams: 1 2016 - Liliane de Souza Ferreira.pdf: 1966686 bytes, checksum: eebcf58399ae9c79283075f9e54588e5 (MD5) / Made available in DSpace on 2017-10-11T20:09:52Z (GMT). No. of bitstreams: 1 2016 - Liliane de Souza Ferreira.pdf: 1966686 bytes, checksum: eebcf58399ae9c79283075f9e54588e5 (MD5) Previous issue date: 2016-08-09 / The management of weeds is complex and comprises a major component of the production cost of most cultures. Growing cover crops is one of the forms of management to reduce weeds competing. Agrobiodiversity, including the biota and the surrounding properties, constituting a cultural and natural capital able to provide ecosystem services. In this context, we developed a study to investigate the potential of wild species Crotalaria incana (rattlesnake rattle or Xique-Xique) and Diodia saponariifolia (Poaia the swamp), which occur in a nearby landscape the Atlantic Forest fragments in the River Basin region Guapi-Macacu-RJ, as part of sustainable agro-ecosystems, constituting strategy to reduce the use of herbicides and enhancing local biodiversity. This potential was assessed in C. incana through phenological studies of plant height, crown diameter, number of branches, presence of inflorescence and number of pods along the cycle and at different times, October, January, February and March. Also evaluated in its interaction with the climate and planting dates. It was found that the planting October C. incana had the longest growing season, low seed production. In the planting in February, the performance of C. incana was good in both parameters; while planting in March, C. incana demonstrated lower performance for mass production and seeds. Preliminary assessments of total biomass and macronutrients, indicate the potential of C. incana as a cover crop that needs to be better investigated. As for D. saponariifolia, a creeping species characterized as macrophyte, evaluations were made of soil coverage percentage after its introduction, compared to the most frequently dominant families in the system, Poaceae and Cyperaceae. Subsequently evaluated the seed bank behavior in this same area after being introduced (experimental area), compared to natural area, which was already established spontaneously. We observed a cooling populations of Poaceae and Cyperaceae after the introduction D. saponariifolia. The spontaneous seed bank revealed a reduction in the expression of these families, important competitors in the system. Possible allelopathic effect of D. saponariifolia in suppressing spontaneous, was evaluated by bioassay with the soil of the natural area where D. saponariifolia prevails spontaneously. In this ground sesame seeds were germinated Sesame indicu L. () in 15-cell trays 3 treatments (T1, T2, T3). T1, activated carbon was added to neutralize allelopathic effects harmful to the development of seedlings. T2, do not add anything. In T3 (control) used a soil adjacent area without the presence of individuals D. saponariifolia. There was no significant difference in the development of seedlings in 3 treatments, indicating no evidence of allelopathic effects of D. saponariifolia on Sesame germination. We can infer that the suppression of processes D. saponariifolia are only for "muffling". / O manejo de plantas espont?neas ? complexo e comp?e um dos principais componentes do custo de produ??o da maioria das culturas. O cultivo de plantas de cobertura ? uma das formas de manejo para redu??o das plantas espont?neas competidoras. Neste contexto desenvolveu-se um estudo com objetivo de investigar o potencial das esp?cies espont?neas Crotalaria incana (Xique-Xique) e Diodia Saponariifolia (Poaia do brejo), que ocorrem em uma paisagem pr?xima a fragmentos de Mata Atl?ntica, na regi?o da Bacia do Rio Guapi-Macacu-RJ, como parte integrante de agroecossistemas sustent?veis, constituindo estrat?gia para redu??o do uso de herbicidas e incremento da biodiversidade local. Este potencial foi avaliado em C. incana, atrav?s de estudos fenol?gicos de altura da planta, di?metro de copa, n?mero de ramos, presen?a de infloresc?ncia e n?mero de vagens ao longo do ciclo e em diferentes ?pocas Outubro, Janeiro, Fevereiro e Mar?o). Avaliou-se tamb?m sua intera??o com o clima e ?pocas de plantio. Constatou-se que no plantio de Outubro, C. incana teve o ciclo vegetativo mais longo, com pouca produ??o de sementes. J? no plantio em Fevereiro, o desempenho de C. incana foi bom em ambos par?metros; enquanto no plantio de Mar?o, C. incana demonstrou menor desempenho tanto para produ??o de massa como de sementes. Avalia??es preliminares de macronutrientes totais e biomassa indicam bom potencial de C. incana a ser melhor investigado. Quanto ? D. Saponariifolia, uma esp?cie rasteira caracterizada como macr?fita, foram feitas avalia??es de porcentagem de cobertura do solo ap?s sua introdu??o, comparando com as fam?lias mais frequentemente dominantes no sistema, Poaceae e Cyperaceae. Posteriormente avaliou-se o comportamento do banco de sementes nesta mesma ?rea ap?s ser introduzida (?rea experimental), comparando com ?rea natural onde j? estava estabelecida espont?neamente. Observou-se um arrefecimento das popula??es de Poaceae e Cyperaceae ap?s a introdu??o D. saponariifolia. O banco de sementes de espont?neas revelou uma redu??o na express?o destas fam?lias e de Asteraceae, importantes competidoras no sistema. Poss?vel efeito alelop?tico de D. saponariifolia na supress?o de espont?neas, foi avaliado atrav?s de biosensaio com o solo da ?rea natural, onde D. saponariifolia predomina espontaneamente. Neste solo foram germinadas sementes de Sesamo indicu L. (Gergelim) em bandejas de 15 c?lulas, com 3 tratamentos (T1,T2,T3). Em T1, adicionou-se carv?o ativado, que neutralizaria efeitos alelop?ticos prejudiciais ao desenvolvimento das pl?ntulas. Em T2, n?o se adicionou nada. Em T3 (controle) utilizou-se um solo da ?rea adjacente, sem presen?a de indiv?duos de D. saponariifolia. N?o houve diferen?a significativa no desenvolvimento das pl?ntulas nos 3 tratamentos, indicando n?o haver evid?ncias de efeitos alelop?ticos de D. saponariifolia na germina??o de Gergelim. Podemos inferir que os processos de supress?o de D. saponariifolia sejam apenas por ?abafamento?.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-02-20T18:25:57Z No. of bitstreams: 1 2017 - F?bio Ferreira Cruvinel.pdf: 1438823 bytes, checksum: 49768f1c89baea668d06d925b16c5e0c (MD5) / Made available in DSpace on 2018-02-20T18:25:57Z (GMT). No. of bitstreams: 1 2017 - F?bio Ferreira Cruvinel.pdf: 1438823 bytes, checksum: 49768f1c89baea668d06d925b16c5e0c (MD5) Previous issue date: 2017-02-21 / CAPES / The pitaya (Hylocereus undatus (Haw.) Britton & Rose) has an exotic shape, pleasant taste, easy digestibility and antioxidant properties, which have given greater demands in the Brazilian market for this fruit in recent years. The production of seedlings is a determining factor for the successful installation of pitaias orchards and the use of phytoregulators such as BAP (6-benzylaminopurine) and organic substrates, such as millipede-compost, in the production of seedlings of this fruit is still little reported. The objective of this work was to analyze the effect of BAP and millipede-compost on the production of pitaia seedlings. Pitaia cuttings from Fazendinha Agroecol?gica - Km 47, in the town of Serop?dica-RJ, were used. The stakes were standardized with 20 cm in length. The experiment with the phytoregulator was conducted in the greenhouse sector of the UFRRJ and the cuttings planted in substrate composed of sand and bovine manure in a ratio of 1: 1 by volume in a completely randomized design (DIC) in a factorial scheme (2X4) with 4 replicates: (2) By immersion and incision made at the apex of cladodes stakes versus (4) four doses of BAP (0, 50, 100 and 150 mg.L-1) were applied. Non-destructive Growth Analysis was performed and the simple correlations were calculated with the climatic data obtained at the Ecologia Automatic Station in Serop?dica-RJ. For the experiment with the millipede compost, the cutting was conducted in pots with three types of substrates: Gongocomposto, Biomix? and sand + bovine manure (1: 1 by volume) in DIC with five replicates. The results showed a linear tendency in number of shoots and quadratic tendency in other parameters (length, fresh and dry weight) evaluated with use of BAP. There was a correlation between the growth rates of the pitaya with the data of Global Solar Radiation of the 19h (22h UTC) period. The use of the gongocomposto showed larger and more vigorous plants of pitaia. / O fruto da pitaieira (Hylocereus undatus (Haw.) Britton & Rose) apresenta forma ex?tica, sabor agrad?vel, f?cil digestibilidade e propriedades antioxidantes, caracter?sticas essas que proporcionaram maiores demandas no mercado brasileiro por essa fruta nos ?ltimos anos. A produ??o de mudas ? um fator determinante para o sucesso da instala??o de pomares de pitaias e o uso de fitorreguladores como o BAP (6-benzilaminopurina) e substratos org?nicos, como o gongocomposto, na produ??o de mudas desta frut?fera ainda ? pouco relatado. O objetivo deste trabalho foi analisar o efeito do BAP e gongocomposto na produ??o de mudas de pitaia. Utilizaram-se estacas de pitaieira proveniente da Fazendinha Agroecol?gica ? Km 47, no munic?pio de Serop?dica-RJ. As estacas foram padronizadas com 20 cm de comprimento. O experimento com o fitorregulador foi conduzido no setor de olericultura da UFRRJ, em casa de vegeta??o e as estacas plantadas em substrato composto por areia e esterco bovino na propor??o 1:1 em volume em Delineamento Inteiramente Casualizado (DIC), com 4 repeti??es, em esquema fatorial (2X4), sendo (2) por imers?o e incis?o feita no ?pice das estacas dos clad?dios versus (4) quatro doses da citocinina BAP (0, 50, 100 e 150 mg.L-1). Foi realizada a An?lise de Crescimento n?o destrutiva e foram calculadas as correla??es simples com os dados clim?ticos obtidos na Esta??o Autom?tica Ecologia em Serop?dica-RJ. Para o experimento com o gongocomposto a estaquia foi conduzida em vasos com tr?s tipos de substratos: Gongocomposto, Biomix? e areia+esterco bovino (1:1 em volume) em DIC com cinco repeti??es. Os resultados mostraram uma tend?ncia linear positiva no n?mero de brota??es e quadr?tica para o incremento de comprimento, peso fresco e seco das brota??es para o uso da citocinina BAP no incremento de. Houve correla??o entre as taxas de crescimento da pitaia com os dados de Radia??o Solar Global do per?odo das 19h (22h UTC). O uso do gongocomposto proporcionou maiores e mais vigorosas mudas de pitaieira.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-10-19T18:05:22Z No. of bitstreams: 1 2013 - Thadia Turon Costa da Silva.pdf: 3226072 bytes, checksum: 9173eea03b722347ce1269d2988d0a42 (MD5) / Made available in DSpace on 2018-10-19T18:05:22Z (GMT). No. of bitstreams: 1 2013 - Thadia Turon Costa da Silva.pdf: 3226072 bytes, checksum: 9173eea03b722347ce1269d2988d0a42 (MD5) Previous issue date: 2013-12-11 / FAPERJ / PIBEX (Programa Institucional de Bolsas de Extens?o, da Pr?-Reitoria de Extens?o - PR5 da Universidade Federal do Rio de Janeiro) / The objective of this study was to evaluate the different dimensions of organic vegetables quality proceeding from Family Agriculture and supplied to the School Food Programme in Petropolis. The evaluation was done based on centesimal composition, antioxidant activity, microbiological characteristics and pesticide residue. The organic vegetables evaluated were carrot (DaucuscarotaL.), broccoli (Brassicaoleraceae, var. it?lica), kale (Brassicaoleraceae, var. acephala) and cabbage (Brassicaoleraceae, var. capitata). The analysis performed were moisture determination, mineral fixed residues, lipid content, total proteins, carbohydrate, soluble and insoluble fibers, total soluble solids, total acidity, pH, ascorbic acid and pesticide residue. The antioxidant activity was based on the separation of DPPH radical and total phenolic content. Microbiologic analyses were conducted regarding sanitary indicators for food which were compared to standard values from the Brazilian legislation. As a complement, a dietary risk evaluation was conducted using the Maximum Theoretical Daily Intake (IDTM) and the Estimated Daily Intake. This evaluation was done through the medium intake for 10 year-old children, maximum limits of pesticide residue (LMR) and pesticide residue values detected on conventional agriculture food items. The results obtained were compared with the security limits (IDA) according to the medium weight of the studied population. The effectiveness of the antioxidant capacity of the vegetables was obtained in a decreasing order: broccoli, kale, cabbage and carrot. Regarding the microbiologic parameter, the vegetables presented a satisfactory sanitary quality. No pesticide residues were found above detection limits for both authorized and non-authorized organic vegetables producers. The organic vegetables analyzed follow the standards for quality and security demanded by the Law 1197/2009 which prioritizes food for the school programme. Regarding the dietary risk evaluation, orange, apple, tomato, rice and beans were the food items which showed, for children, the highest chronic intake risk for presenting IDTM higher than IDA for the following pesticides: dicofol, dimethoate, methidathion, pirimiphos-methyl, tetraconazol and carbaryl. Key-words: organic food, vegetables, food security / O presente estudo teve como objetivo avaliar as diferentes dimens?es da qualidade de hortali?as org?nicas provenientes da agricultura familiar fornecidas ? alimenta??o escolar do munic?pio de Petr?polis, a partir da avalia??o da composi??o centesimal, atividade antioxidante, caracter?sticas microbiol?gicas e res?duos de agrot?xicos. Foram avaliadas cenouras (DaucuscarotaL.), br?colis (Brassicaoleraceae, var. it?lica), couves (Brassicaoleraceae, var. acephala) e repolhos (Brassicaoleraceae, var. capitata) org?nicas atrav?s da determina??o da umidade, res?duos minerais fixos (cinzas), teor de lip?dios, prote?nas totais, carboidratos, fibras sol?veis e insol?veis, s?lidos sol?veis totais, acidez total, pH, ?cido asc?rbico e res?duos de agrot?xicos. A atividade antioxidante foi baseada no sequestro do radical DPPH e teor de fen?licos totais. Foram realizadas an?lise microbiol?gicas referentes aos indicadores higi?nico-sanit?rios de alimentos e comparadas aos padr?es da legisla??o brasileira. Em complementa??o, foi realizado estudo de avalia??o do o risco cr?nico da ingest?o de pesticidas pela dieta utilizando a Ingest?o Di?ria Te?rica M?xima (IDTM) e a Estimativa de Ingest?o Di?ria (EDI) a partir dos limites m?ximos de res?duos estabelecidos pela legisla??o brasileira e dados de consumo alimentar de crian?as de 10 anos, e valores de res?duos de agrot?xicos detectados em alimentos da agricultura convencional. Os resultados obtidos foram comparados com os limites de seguran?a (Dose di?ria aceit?vel - IDA) em fun??o do peso m?dio da popula??o estudada. Dentre as hortali?as analisadas, a efetividade na capacidade antioxidante foi obtida, em ordem decrescente, pelos br?colis, couves, repolhos e cenouras. Sob o par?metro microbiol?gico, as hortali?as avaliadas apresentaram qualidade higi?nico-sanit?ria satisfat?ria. N?o foram encontrados res?duos de agrot?xicos acima do limite de detec??o, tanto para os autorizados como para aqueles n?o autorizados nas culturas org?nicas analisadas. As hortali?as org?nicas estudadas atendem ao padr?o de qualidade e seguran?a exigidos pela Lei n?11947/2009 devendo ser priorizadas para a alimenta??o escolar. Na avalia??o do risco cr?nico da ingest?o de pesticidas pela dieta a laranja, ma??, tomate, arroz e feij?o foram os alimentos que mais contribu?ram para a ingest?o. Os compostos que apresentaram maior risco foram dicofol, dimetoato, metidationa, pirimif?s met?lico, tetraconazol e carbaril por apresentarem a IDTM maior que a IDA. Palavras-chave: alimentos org?nicos, vegetais, seguran?a alimentar.

Made available in DSpace on 2014-12-17T14:52:34Z (GMT). No. of bitstreams: 1 ErnestoATN.pdf: 2867586 bytes, checksum: 365968b169b7f677e1d1f4d8af8d3fab (MD5) Previous issue date: 2006-05-19 / The Brazilian organic market has growing year by year, and this commercialization is extremely important to the country, because it allows a bigger preoccupation with the environmental preservation, as well as to create employments and income to the rural workers. However, is necessary that these producers define forms of competition in the market, the way how they will compete, focusing aspects that really matters to the clients. So, the work objective is investigate, based in the rural producers perceptions, the facts which affect the competition the production of organics vegetables in the state of Rio Grande do Norte. With the aim of contribute to the made of strategic decisions related to the production and commercialization of these products in the agriculture scenery norte-rio-grandense, besides to contribute with information about the competition, helping as reference to others important researches. In the methodological view, this study can be qualified as an applied research study, with descriptive objective and quantitative approach. The instrument used was the formulary, resuming to producers of organics products in Rio Grande do Norte state, that grows the segment of organic types of vegetables and greens, been thirty two producers. The data was treated through of the descriptive analyze and the Cluster s analyze. The descriptive research results indicate that the main factors which affect the competition of the organics products in our State are the cost, the diversification and reliability. The Cluster s analyze shows that exists am group of organics producers who uses frequently a specialized technique and they give support to the bigger retail market, as supermarkets / O mercado org?nico brasileiro vem crescendo a cada ano, e essa comercializa??o ? extremamente importante para o pa?s, pois possibilita uma maior preocupa??o com a preserva??o ambiental, al?m de gerar emprego e renda para os trabalhadores rurais. Para tanto, ? necess?rio que esses produtores definam formas de competir no mercado, focalizando os aspectos que realmente importam para os clientes. Portanto, o objetivo deste trabalho ? investigar, com base na percep??o dos produtores rurais, os fatores que afetam a competitividade na produ??o de hortali?as org?nicas no Estado do Rio Grande do Norte, com a finalidade de contribuir para a tomada de decis?es estrat?gicas no que diz respeito ? produ??o e comercializa??o no cen?rio agr?cola norte-rio-grandense, al?m de disponibilizar informa??es sobre a competitividade desses produtos, a fim de servir de refer?ncia para outras pesquisas que sejam pertinentes. Do ponto de vista metodol?gico, o presente trabalho pode ser classificado como um estudo de pesquisa aplicada, com objetivo descritivo e abordagem quantitativa. O instrumento utilizado foi o formul?rio, delimitando-se a pesquisar os produtores de produtos org?nicos do Estado Rio Grande do Norte, que cultivam o segmento do tipo legumes e verduras org?nicas, totalizando trinta e dois produtores. Os dados foram tratados atrav?s da An?lise Descritiva e da An?lise de Cluster. Resultados da pesquisa descritiva indicaram que os principais fatores que afetam a competitividade dos produtos org?nicos no Estado do Rio Grande do Norte s?o os custos, a diferencia??o e a confiabilidade. A an?lise de Cluster apresentou que existe um agrupamento de produtores org?nicos que utilizam com maior freq??ncia ? ajuda de t?cnico especializado e este mesmo grupo ? o que atende ao ramo varejista de maior porte, como supermercados

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-29T20:24:19Z No. of bitstreams: 1 JoseDenilsonDePaulaAraujo_DISSERT.pdf: 884420 bytes, checksum: 356fafd728157445de94d84ed5a369f3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-09-06T00:01:51Z (GMT) No. of bitstreams: 1 JoseDenilsonDePaulaAraujo_DISSERT.pdf: 884420 bytes, checksum: 356fafd728157445de94d84ed5a369f3 (MD5) / Made available in DSpace on 2016-09-06T00:01:51Z (GMT). No. of bitstreams: 1 JoseDenilsonDePaulaAraujo_DISSERT.pdf: 884420 bytes, checksum: 356fafd728157445de94d84ed5a369f3 (MD5) Previous issue date: 2014-12-19 / Biocombust?veis s?o um foco de discuss?o, ao que se trata de energias renov?veis. Quanto a esse ponto, atualmente discutisse a utiliza??o de zonas ?ridas para produ??o de biocombust?veis derivados de esp?cies oleaginosas resistentes ?s condi??es de aridez. A Jatropha curcas L. tem sido indicada como uma esp?cie potencial para esse tipo de utiliza??o, apontada pela literatura como resistente em condi??es desfavor?veis: seca e salinidade. Todavia, pouco ? descrito sobre sua resist?ncia a altas temperaturas e secas severas, principalmente sobre a sinergia de estresses combinados, cen?rio t?pico de regi?es semi?ridas. Este trabalho visa portanto avaliar os efeitos da temperatura sobre a J. curcas em condi??es de seca. O estresse h?drico foi aplicado utilizando duas concentra??es de PEG6000 dilu?das em solu??o hidrop?nica, induzindo potencial h?drico de -0,3 e -0,7 MPa. J? o estresse t?rmico foi conduzido em B.O.D. ? 40?C. Ap?s aplica??o dos estresses, o material vegetal foi coletado para avalia??o dos indicadores de estresse como conte?do relativo de ?gua (CRA) e dano de membrana (DM), al?m das determina??es bioqu?micas de prote?nas, amino?cidos totais (AALT), prolina (PRO) e glicina beta?na (GB), a??cares sol?veis totais (AST) e amido. Os resultados mostraram que o CRA pouco se altera, em condi??es de estresse e DM foi menor sob estresse t?rmico. Os solutos AALT, PRO e amido tiveram concentra??es mais significativas em folhas, enquanto que prote?nas, GB e AST foram mais significativas nas ra?zes. Quanto ? observa??o dos efeitos provocados pelo estresse h?drico, este trabalho fez compara??es a resultados semelhantes obtidos em outros estudos, refor?ando afirma??es sobre a efici?ncia das respostas da J. curcas em condi??es de seca. Todavia as plantas se mostraram mais suscept?veis ao estresse t?rmico, embora, quando em estresses combinados as respostas tenderam ao aumento em compara??o ao estresse t?rmico isolado. No geral, estes resultados abrem espa?o para que novos estudos sejam realizados a fim de testar os efeitos dos estresses combinados sobre a J. curcas e quais respostas a planta pode apresentara sob estas condi??es. / Biofuels are a focus of discussion when it comes to renewable energy. On this point, actually disc uss the use of arid zones for production of biofuels derived from oil plant species resistant to arid conditions. Jatropha curcas L. has been indicated as a potential species for this application, because it resistance to unfavorable conditions as: drought and salinity. However, a few studies have been described about its resistance to high temperatures and severe droughts, especially on the synergy of combined stresses, typical of semiarid lands. This study aims to evaluate the temperature effects of J. curcas on dry conditions. Water stress was caused using two concentrations of PEG6000 diluted in hydroponic solution, inducing water potentials of - 0.3 and - 0.7 MPa, while the heat stress was conducted in growth chamber at 40?C. After applying the stress, the plant material was collected for evaluation of stress indicators such as relative water content (RWC), membrane damage (MD) and absolute growth rate (AGR), and the biochemical determinations of proteins, total amino acids (TFAA), proline (PRO), glycine betaine (GB), total soluble sugars (TSA) and starch. The results showed that the RWC few changes in stress conditions and MD was lower under heat stress, probably due to the contribution of solutes such as protein and GB. Solutes TFAA, PRO and starch had more significant concentrations in leaves, while proteins, GB and TSA were more significant in the roots. TFAA and PRO were solutes with more significant responses on leaves, mainly in severe drought under heat stress. GB had an increase in the concentrations both in leaves and in roots, when under to drought and heat stress. Starch concentrations was reduced, which may be a reflex the reduction of AGR of the seedlings. The data suggest that J. curcas is able to withstand the effects of droughts tress, considering fewer changes of the CRA under the studied conditions. Overall the seedlings were more sensitive to heat stress. However, when combined the both drought and heat stresses, the results showed an increasing trend in relation to just heats tress.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-23T13:04:51Z No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-23T13:05:17Z (GMT) No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-23T13:05:35Z (GMT) No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-12-23T13:05:35Z (GMT). No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / As turfeiras s?o importantes reguladores dos fluxos de ?gua e de elementos, principalmente do carbono, entre os compartimentos terrestres e aqu?ticos. O objetivo deste trabalho foi caracterizar qualiquantitativamente os Organossolos e os recursos h?dricos das turfeiras das cabeceiras do Rio Ara?ua? quanto ? disponibilidade h?drica e a din?mica do carbono no sistema solo-?gua. Coletou-se oito testemunhos representantes de quatro perfis de solo do Campo Limpo ?mido e Floresta Estacional Semidecidual de duas turfeiras nas cabeceiras de afluentes do Rio Ara?ua? (C?rrego Cachoeira dos Borges e Rio Preto), descritos e caracterizados f?sica, qu?mica, elementar e morfologicamente. Em tr?s pontos do curso d??gua de cada afluente e duas ?pocas (chuvosa e seca) foram coletadas amostras de ?gua e analisados os seus atributos f?sicos e qu?micos. Procedeu-se o mapeamento das turfeiras e o c?lculo dos volumes e fluxos de ?gua e de carbono. Empregou-se an?lise de vari?ncia para atestar o efeito das fitofisionomias, profundidades de amostragem e das intera??es destes fatores sobre as vari?veis do solo. Para os atributos da ?gua atestaram-se efeitos dos locais (afluentes), ?pocas de amostragem e das intera??es entre estes fatores. Boa parte dos atributos caracterizadores da mat?ria org?nica e a composi??o elementar do solo apresentaram diferen?as significativas entre os locais, fitofisionomias e profundidades de amostragem e variaram em fun??o da composi??o e grau de evolu??o do material org?nico. A maioria dos atributos f?sico-qu?micos das ?guas n?o diferenciou entre os locais e nem entre as ?pocas, mas foram influenciados pelos atributos dos Organossolos de onde se originam. A turfeira do Rio Preto estoca 4.299,39 t de C (206,70 t ha-1) e 227.258,15 m3 de ?gua (10.925,87 m3 ha-1) e a turfeira do C?rrego Cachoeira dos Borges estoca 14.781,09 t de C (184,10 t ha-1) e 745.950,30 m3 de ?gua (9.290,70 m3 ha-1). A vaz?o do Rio Preto foi de 0,023 m3 s-1 e do C?rrego Cachoeira dos Borges foi de 0,067 m3 s-1 no per?odo chuvoso. No per?odo seco estes cursos d??gua apresentaram vaz?o m?nima constante, demonstrando a capacidade das turfeiras de suas cabeceiras de perenizar a vaz?o. Estimou-se o lan?amento de uma carga m?dia de 360,84 t ano-1 de N e 6.812,73 t ano-1 de C e de 917,32 t ano-1 de N e 33.516,16 t ano-1 de C, respectivamente para o Rio Preto e C?rrego Cachoeira dos Borges. As turfeiras das cabeceiras dos afluentes do Rio Ara?ua? influenciam significativamente na vaz?o e na qualidade de suas ?guas, sendo urgente a necessidade de preserva??o destes pedoambientes. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The peatlands are important regulators of water flows and elements between terrestrial and aquatic compartments, especially of the carbon. The objective of this study was to characterize qualitatively and quantitatively the Histosols and water resources of headwater from peatlands of the Rio Ara?ua? as to hydric availability and carbon dynamics in the soil-water system. Been collected eight testimonies representatives from four soil profiles of moist meadow and semi-deciduous seasonal forest in two peatlands in the headwaters of affluents of the Rio Ara?ua? (C?rrego Cachoeira dos Borges e Rio Preto), described and characterized physics, chemistry, elementary and morphologically. In three points of each watercourse affluent and two seasons (wet and dry) water samples were collected and analyzed their physical and chemical attributes. Been done the mapping of peatlands and the calculation of volumes and flows of water and carbon. It was used analysis of variance to attested effect of vegetation types, sampling depths and the interactions of these factors over soil variables. For the attributes of water attested effects of local (affluents), sampling periods and the interactions between these factors. Much of the attributes that characterize the organic matter and elemental composition of the soil, showed significant differences between the sites, vegetation types and depths of sampling and varied according to the composition and degree of evolution of the organic material. Most physical and chemical attributes of the water did not differ between the sites and between sampling periods, but were influenced by the attributes of the Histosols of where they originate. The peatland from Rio Preto stocks 4,299.39 tons of C (206.70 tons ha-1) and 227,258.15 m3 (10,925.87 m3 ha-1) of water and peatland from the C?rrego Cachoeira dos Borges stocks 14,781.09 tons of C (184.10 tons ha-1) and 745.950,30 m3 (9.290,70 m3 ha-1) of water. The flow of water of the Rio Preto was 0.023 m3 s-1 and of the C?rrego Cachoeira dos Borges was 0.067 m3 s-1 in the rainy season. These watercourses showed constant minimum flow in the dry season, demonstrating the capacity of peatlands its headwaters to maintain water flow. It has been estimated the launch of a load average of 360.84 tons year-1 of N and 6812.73 tons year-1 of C and of 917.32 tons year-1 of N and 33516.16 tons year-1 of C respectively for the Rio Preto and C?rrego Cachoeira dos Borges. The peatlands from the headwaters of the affluents of the Rio Ara?ua? have a significant influence the flow and quality of its waters, and the urgent need to preservation these pedological environments.

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.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:45Z No. of bitstreams: 5 fab.pdf: 3600092 bytes, checksum: 62e73afe3033394e17b7ea0fbf24fbf8 (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 2015-02-20T10:44:39Z (GMT) No. of bitstreams: 5 fab.pdf: 3600092 bytes, checksum: 62e73afe3033394e17b7ea0fbf24fbf8 (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 2015-02-20T10:44:39Z (GMT). No. of bitstreams: 5 fab.pdf: 3600092 bytes, checksum: 62e73afe3033394e17b7ea0fbf24fbf8 (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: 2013-02-20 / Eletrodos perme?veis a fluidos (EPF) foram confeccionados mediante a eletrodeposi??o do di?xido de chumbo (PbO2) sobre substratos constitu?dos de tecido de carbono (TC) do tipo sarja empregando-se diferentes condi??es experimentais. Foi investigada a influ?ncia dos diferentes tipos de pr?-tratamento do TC na eletross?ntese dos filmes de PbO2. Os substratos pr?-tratados foram caracterizados empregando-se a t?cnica de voltametria c?clica (VC), enquanto que os filmes de PbO2 suportados sobre o TC pr?-tratado foram caracterizados pelas t?cnicas de difratometria de raios-X (DRX), microscopia ?tica (MO), microscopia eletr?nica de varredura (MEV), e a voltametria. Foi verificado que o pr?-tratamento do TC empegando-se o isopropanol ? o mais apropriado para a eletross?ntese dos filmes de PbO2 visando a obten??o de um EPF. O estudo de caracteriza??o ?ex-situ? (DRX, MO e MEV) revelou que as condi??es experimentais mais satisfat?rias para a forma??o da fase ?-PbO2 sobre o TC pr?-tratado, de modo a se obter um EPF, s?o: pH ? 2; 40 oC ? T < 70 oC, e 40 mA cm-2. O comportamento eletroqu?mico do EPF (TC/?-PbO2) foi investigado na condi??o de ?zero-gap? empregando-se a membrana Nafion? 117 (DuPont) como eletr?lito s?lido e a ?gua destilada como fase l?quida. A an?lise das curvas de polariza??o registradas em condi??es quase-estacion?rias para o processo eletr?dico misto da rea??o de desprendimento de oxig?nio (RDO) acompanhada pela rea??o de forma??o de oz?nio (RFO) revelou a presen?a de duas inclina??es de Tafel distribu?das nos dom?nios dos baixos e dos altos sobrepotenciais. Foi obtido um valor de 16 kJ mol-1 para a entalpia de ativa??o aparente determinada no dom?nio dos elevados sobrepotenciais. O estudo envolvendo a quantifica??o do oz?nio produzido com o anodo do tipo TC/?-PbO2 empregando-se um prot?tipo de reator do tipo filtro-prensa revelou que este tipo de EPF n?o ? adequado para o processo da produ??o eletroqu?mica de oz?nio. Entretanto, a grande estabilidade qu?mica e mec?nica apresentada pelo TC/?-PbO2 aliada ao seu grande sobrepotencial para o processo da RDO permite inferir que reatores do tipo filtro-prensa empregando-se este tipo de anodo s?o bastante promissores para processos de interesse ambiental envolvendo a combust?o de poluentes org?nicos presentes em ?guas. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT Electrodes permeable to fluids (EPF) were fabricated by electrodeposition of lead dioxide (PbO2) on substrates made of twill type woven carbon (TC) using different experimental conditions. There has been investigated the influence of the different types of pre-treatment on TC in the electrosynthesis of PbO2 films. The pretreated substrates were characterized using the technique of cyclic voltammetry (VC), while the PbO2 films supported on pre-treated TC were characterized by the techniques of X-ray diffraction (DRX), optical microscopy (MO), scanning electron microscopy (MEV) and voltammetry. It was observed that the pre-treatment of TC using isopropanol is the most suitable electrosynthesis of PbO2 films for obtaining an EPF. The characterization study "ex-situ" (DRX, MO e MEV)) revealed that the experimental conditions more suitable for the formation of phase ?-PbO2 on the TC pre-treated in order to obtain an EPF, are pH ? 2; 40 oC ? T < 70 oC, e 40 mA cm-2. The electrochemical behavior of EPF (TC/?-PbO2) was investigated in the condition of "zero-gap" employing the Nafion? 117 membrane (DuPont) as solid electrolyte and distilled water as the liquid phase. The analysis of polarization curves recorded in quasi-stationary conditions for the mix electrode process of from the mixture of oxygen detachment reaction (RDO) accompanied by the reaction of ozone formation (RFO) has revealed the presence of two Tafel slopes distributed in the areas of low and high overpotentials. There was obtained a value of 16 kJ mol-1 for the apparent activation enthalpy determined in the field of high overpotentials. The study involving the measurement of ozone produced in the anode-type TC/?-PbO2 employing a prototype reactor of the filter-press revealed that this type of EPF is not suitable for the process of electrochemical production of ozone. However, the high chemical and mechanical stability provided by the TC/?-PbO2 combined with its large overpotential for the process of RDO allows to infer that reactors of filter-press employing this type of anode are very promising for processes of environmental interest involving the combustion of organic pollutants in waste water.