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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

Caracteriza??o gen?tica de arroz (Oryza Sativa L.) atrav?s de marcadores moleculares RAPD e efici?ncia na aquisi??o de N. / Genetic Characterization of Rice (Oryza sativa l.) Using the RAPD Molecular Markers and Nitrogen Uptake Efficiency.

Baptista, Jane de Ara?jo 27 March 2002 (has links)
Submitted by Leticia Schettini (leticia@ufrrj.br) on 2016-08-05T14:09:04Z No. of bitstreams: 1 2002 Jane Ara?jo Baptista.pdf: 1264077 bytes, checksum: 40b93a67e37e2aad7edfc01cc029f2c4 (MD5) / Made available in DSpace on 2016-08-05T14:09:04Z (GMT). No. of bitstreams: 1 2002 Jane Ara?jo Baptista.pdf: 1264077 bytes, checksum: 40b93a67e37e2aad7edfc01cc029f2c4 (MD5) Previous issue date: 2002-03-27 / We have studied the influence of using 6 different coefficients of similarity when grouping 16 varieties of rice analyzed by the RAPD technique. DNA samples of these varieties were amplified using 20 primers, only 15 (75%) of which produced amplified fragments, compresing 90 of these were polimorphic fragments. The analysis of the band, profile produced a ?fingerprint?. For the calculation of the similarity index several coefficients were tested: Nei & Li, Jaccard, Ochiai, Russel & Rao, Simple Matching and Rogers & Tanimoto. Comparison among them was carried out through the evaluation of the dendrograms generated by the UPGMA algorithm and by the correlations between the genetic pitches. The coefficients of Nei & Li, Jaccard, and Ochiai discriminated the varieties in three main groups according to their genetic similarities. Our results show that the coefficients of Nei & Li, Jaccard and Ochiai adjusted better the groups with hight genetic similarities. While the coefficients Simple Matching and Rogers & Tanimoto were not as efficient, banding together varieties that are genetically different. In experiments, with the objective to studies the effect of levels (20 or 60 mg N/L) e forms of N (NH4 + and NO3 -) under the kinetics parameters, proton extrusion, the activity of the N-assimilation enzymes and the N-partition in the plant, were conducted in greenhouse, using 5 upland rice varieties (Lageado, IAC 47, Dobradinho, Agulha e Bico Ganga), in nutrient solution. It was observed an ample variation of the kinetics parameters and biochemists, and a distinguishing behavior among varieties in the uptake and use of N. The varieties Agulha and IAC-47 had presented the best combination of KM, Vm?x, GS/GOGAT in conditions of hight avaibility of N- NO3 -, and Bico Ganga, in conditions of low avaibility of N- NO3 - in nutrient solution. In another experiment, with the objective to study the assimilation and remobiliza??o of N in season nitrate conditions, used varieties Sagrim?o, Goiano, Zebu, Agulha, IAC 1278, IR08, Comum Branco, IAC 47 e Ligeiro had been cultivated in nutritional solution. The N-assimilation enzymes were estudied in the leaf blades and root of 62 and 69 days old rice plants, under 20 and 200 mg mgN-NO3 -/L. Under higher nitrate supply had increase the activity of the NR, GS and GOGAT in rice plants. The GS activities had been low in roots, in comparison with the activities observed in leaf. The GOGAT activity was bigger in roots, in both the treatments. The GDH-A activity occurred mainly in tessues foliar. The GDH-D activity occurred in leaf as in roots. The GDH-D activity not occurred in tissues foliar. The activity of the enzymes of N-assimilation was higher in tissues foliar. These results seem indicate the leaves as the main site of NH4 +-N assimilation in rice plants under higher NO3 --supply. / Neste trabalho avaliaram-se as altera??es provocadas por 6 diferentes coeficientes de similaridade no agrupamento de 16 variedades de arroz analisadas pela t?cnica de RAPD. Amostras de DNA das variedades foram amplificadas com 20 iniciadores, sendo 15 (75%) produziram fragmentos amplificados, resultando em 90 fragmentos polim?rficos. A an?lise dos resultados se constituiu na descri??o do padr?o de bandas. Para o c?lculo do coeficiente de similaridade foram testados os coeficientes Nei & Li, Jaccard, Ochiai, Russel & Rao, Simple Matching e Rogers & Tanimoto, sendo as compara??es entre eles realizadas pela avalia??o dos dendrogramas gerados pelo algoritmo UPGMA e pelas correla??es entre as dist?ncias gen?ticas. Os resultados obtidos indicam que os melhores coeficientes para determina??o da similaridade foram os de Nei & Li, de Jaccard e de Ochiai que foram capazes de agrupar as variedades com alta similaridade, enquanto os coeficientes Simple Matching e de Rogers & Tanimoto foram ligeiramente inferiores colocando variedades distantes no mesmo grupo. Em experimentos objetivando analisar o efeito de n?veis (20 e 60 mg N/L) e formas de N (NH4 + e NO3 -) sob os par?metros cin?ticos de absor??o, a extrus?o de pr?tons, a atividade das enzimas de assimila??o de N, e a parti??o de N na planta, usou-se 5 variedades de arroz-de-sequeiro (Lageado, IAC 47, Dobradinho, Agulha e Bico Ganga), cultivadas em solu??o nutritiva. Houve um comportamento diferencial entre as variedades quanta ? capacidade de absor??o e uso de N. As variedades Agulha e IAC 47 apresentaram a melhor combina??o de KM, Vm?x, GS/GOGAT em condi??es de alta disponibilidade de N-NO3 -, e a variedade Bico Ganga, sob condi??es de baixa disponibilidade de N. Noutro experimento, objetivando estudar a assimila??o e remobiliza??o de N em condi??es sazonais de N, utilizou-se as variedades Sagrim?o, Goiano, Zebu, Agulha, IAC 1278, IR 08, Comum Branco, IAC 25 e Ligeiro, com 62 e 69 dias de idade, cultivadas em solu??o nutritiva, com 20 e 200 mg N-NO3 -/L. O aumento no suprimento de N aumentou a atividade da NR, da GS e GOGAT. A atividade de NR ocorreu em ra?zes e na parte a?rea. A atividade da GS foi baixa em ra?zes. A atividade da GOGAT foi maior nas ra?zes, em ambos os tratamentos. A atividade de GDH-A ocorreu principalmente em tecidos foliares. A atividade de GDHD ocorreu tanto em folhas como em ra?zes. A atividade das enzimas de assimila??o de N foi superior nas folhas, indicando serem estas os principais s?tios de incorpora??o de am?nio em amino?cidos, quando plantas de arroz s?o submetidas a altos n?veis de NO3 -.
2

Estudo do crescimento, efici?ncia de biofiltra??o e cin?tica de absor??o de nutrientes (N-NH, N-NO e P-PO4?) da macroalga Gracilaria cervicornis (Turner) J. Agardh

Carneiro, Marcella Ara?jo do Amaral 07 March 2007 (has links)
Made available in DSpace on 2014-12-17T14:02:03Z (GMT). No. of bitstreams: 1 MarcellaAAC.pdf: 1596539 bytes, checksum: 311fd18dd515bf47c2eb0788bcbd609a (MD5) Previous issue date: 2007-03-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The objective of this study was to examine the growth of Gracilaria cervicornis cultured in a shrimp (Litopenaeus vannamei) pond and to determine the absorption efficiency and the kinetics parameters (Vmax, Ks e Vmax:Ks) of this macroalgae for the nutrients N-NO3-, N-NH4+ and P-PO4-3, aiming at its use as bioremediatory of eutrophicated environments. For this study, two experiments (field and laboratory) were developed. In the field study, the seaweed was examined in relation to the growth and the biomass. In the laboratory experiment, the absorption efficiency of G. cervicornis was measured through the monitoring of the concentration of the three nutrients (N-NO3-, N-NH4+ e P-PO4-3) during 5 hours and the kinetic parameters were determined through the formula of Michaelis-Menten. The results obtained in this study demonstrated that G. cervicornis benefited from the available nutrients in the pond, increasing 52.4% of its biomass value after 30 days of culture. It was evidenced that the variability of the biomass could be explained through the salinity, availability of light (transparency and solid particle in suspension) and concentration of N-NO3- in the environment. In the laboratory experiment, the highest absorption efficiency was found in the treatments with low concentration (5 ?mol.L-1), being evidenced a reduction of up to 85,3%, 97,5% and 81,2% of N-NH4+, N-NO3- and P-PO43-, respectively. Regarding the kinetic parameters, G. cervicornis presented better ability in absorbing N-NH4+ in high concentrations (Vmax = 158,5 ?mol g-1 dry wt h-1) and P-PO43- in low concentrations (Ks = 5 ?mol.L-1 e Vmax:Ks = 10,3). The results of this study show that G. cervicornis could be cultivated in shrimp ponds, presents a good capacity of absorption for the tested nutrients and is a promising candidate for biorremediation in shrimp pond effluent / O objetivo deste estudo foi avaliar o crescimento da macroalga Gracilaria cervicornis em um viveiro de camar?o (Litopenaeus vannamei) e determinar a efici?ncia de absor??o e os par?metros cin?ticos (Vmax, Ks e Vmax:Ks) desta esp?cie para os nutrientes N-NH4+, N-NO3- e P-PO4-3, visando a sua utiliza??o como biorremediadora de ambientes eutrofizados. Para este estudo, foram desenvolvidos dois experimentos (campo e laborat?rio). No estudo em campo, a macroalga foi examinada em rela??o ao crescimento e a biomassa. No experimento em laborat?rio, a efici?ncia de absor??o de G. cervicornis foi medida atrav?s do monitoramento das concentra??es dos tr?s nutrientes (N-NO3-, N-NH4+ e P-PO4-3) durante 5 horas e os par?metros cin?ticos foram determinados atrav?s da f?rmula de Michaelis-Menten. Os resultados obtidos neste estudo demonstraram que G. cervicornis se beneficiou dos nutrientes dispon?veis no viveiro, aumentando 52,4% do valor de sua biomassa ap?s 30 dias de cultivo. Neste estudo foi constatado que a variabilidade da biomassa p?de ser explicada atrav?s da salinidade, disponibilidade de luz (transpar?ncia e concentra??o de part?culas s?lidas em suspens?o) e concentra??es do N-NO3- no ambiente (r-Pearson= 0,76; p<0,05). Quanto ao experimento em laborat?rio, foi observado que a efici?ncia de absor??o da macroalga estudada foi maior nos tratamentos com menor concentra??o (5 ?mol.L-1), sendo constatada uma redu??o de at? 85,3%, 97,5% e 81,2% do N-NH4+, N-NO3- e P-PO43-, respectivamente. Quanto aos par?metros cin?ticos, G. cervicornis apresentou uma maior habilidade em absorver o N-NH4+ em altas concentra??es (Vmax = 158,5 ?mol g-1 dry wt h-1) e o P-PO43- em baixas concentra??es (Ks = 5 ?mol.L-1 e Vmax:Ks = 10,3). Os resultados deste estudo mostram que G. cervicornis pode ser cultivada em viveiros de camar?o e que apresenta uma boa capacidade de absor??o dos nutrientes testados, podendo desta forma, ser uma candidata promissora como biorremediadora de efluentes de camar?o
3

Avalia??o da remo??o de sulfeto de hidrog?nio do g?s natural em uma coluna de absor??o

Silva Filho, Luiz Ferreira da 05 March 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:19Z (GMT). No. of bitstreams: 1 LuizFSF.pdf: 1747527 bytes, checksum: e75c5e8a2575620cc3a29490253bcad6 (MD5) Previous issue date: 2009-03-05 / Natural gas, although basically composed by light hydrocarbons, also presents in its composition gaseous contaminants such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). Hydrogen sulfide, which commonly occurs in oil and gas exploration and production activities, besides being among the gases that are responsible by the acid rain and greenhouse effect, can also cause serious harm to health, leading even to death, and damages to oil and natural gas pipelines. Therefore, the removal of hydrogen sulfide will significantly reduce operational costs and will result in oil with best quality to be sent to refinery, thereby resulting in economical, environmental, and social benefits. These factors highlight the need for the development and improvement of hydrogen sulfide sequestrating agents to be used in the oil industry. Nowadays there are several procedures for hydrogen sulfide removal from natural gas used by the petroleum industry. However, they produce derivatives of amines that are harmful to the distillation towers, form insoluble precipitates that cause pipe clogging and produce wastes of high environmental impact. Therefore, the obtaining of a stable system, in inorganic or organic reaction media, that is able to remove hydrogen sulfide without forming by-products that affect the quality and costs of natural gas processing, transport and distribution is of great importance. In this context, the evaluation of the kinetics of H2S removal is a valuable procedure for the treatment of natural gas and disposal of the byproducts generated by the process. This evaluation was made in an absorption column packed with Raschig ring, where natural gas with H2S passes through a stagnant solution, being the contaminant absorbed by it. The content of H2S in natural gas in column output was monitored by an H2S analyzer. The comparison between the obtained curves and the study of the involved reactions have not only allowed to determine the efficiency and mass transfer controlling step of the involved processes but also make possible to effect a more detailed kinetic study and evaluate the commercial potential of each reagent / O g?s natural, embora seja composto basicamente de hidrocarbonetos leves, apresenta tamb?m em sua composi??o gases contaminantes como o CO2 (Di?xido de carbono) e o H2S (Sulfeto de hidrog?nio). O H2S, que comumente ocorre nas atividades de explora??o e produ??o de ?leo e g?s, al?m de estar entre os respons?veis pela chuva ?cida e pelo efeitoestufa, causa s?rios danos ? sa?de, levando inclusive ? morte, e danifica as tubula??es de transporte do petr?leo e do g?s natural. Por isso, eliminando-se o g?s sulf?drico haver? significativa redu??o dos custos de opera??o e uma melhor qualidade do ?leo destinado ? refinaria, resultando assim num beneficio econ?mico, ambiental e social. Tudo isso demonstra a necessidade do desenvolvimento e aprimoramento de seq?estrantes que removam o sulfeto de hidrog?nio da ind?stria de petr?leo. Atualmente existem v?rios processos para o tratamento do g?s natural utilizados pela ind?stria petrol?fera para remo??o do H2S, no entanto eles produzem derivados de aminas prejudiciais ?s torres de destila??o, precipitados insol?veis que provocam entupimento dos dutos e originam res?duos de grande impacto ambiental. Por isso, a obten??o de um sistema est?vel em meio reacional inorg?nico ou org?nico capaz de remover o g?s sulf?drico sem formar subprodutos que afetem a qualidade e o custo do processamento, transporte e distribui??o do g?s natural ? de grande import?ncia. Nesse contexto a avalia??o da cin?tica de remo??o do H2S surge como um procedimento valioso para o tratamento do g?s natural e destino dos subprodutos do processo. Esta avalia??o foi feita numa coluna de absor??o recheada com an?is de Raschig, por onde o g?s natural contaminado com H2S atravessava uma solu??o estagnada, sendo por esta absorvida. Na sa?da da coluna o teor de H2S no g?s era monitorado por um analisador de H2S. A compara??o das curvas obtidas e o estudo das rea??es permitiram n?o somente determinar a efici?ncia e a etapa controladora da transfer?ncia de massa dos processos envolvidos como tamb?m efetuar um estudo cin?tico mais aprofundado e avaliar o potencial comercial de cada reagente

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