401 resultados para Parâmetros físicos do solo


Relevância:

80.00% 80.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This study used a multi-analytical approach based on traditional microbiological methods for cultivation and isolation of heterotrophic bacteria in the laboratory associated with the molecular identification of the isolates and physicochemical analysis of environmental samples. The model chosen for data integration was supported by knowledge from computational neuroscience, and composed by three modules: (i) microbiological parameters, contemplating taxonomic data obtained from the partial sequencing of the 16S rRNA gene from 80 colonies of heterotrophic bacteria isolated by plating method in PCA media. For bacterial colonies isolation were used water samples from Atibaia and Jaguarí rivers collected at the site of water captation for use in effluent treatment, upstream from the entrance of treated effluent from the Paulínia refinery (REPLAN/Petrobras) located in the Paulínia-SP municipality, from the output of the biological treatment plant with stabilization pond and from the raw refinery wastewater; (ii) chemical parameters, ending measures of dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, acidity CaCO3, alkalinity, ammonia, nitrite, nitrate, dissolved ions, sulfides, oils and greases; and (iii) physical parameters, comprising the pH determination, conductivity, temperature, transparency, settleable solids, suspended and soluble solids, volatile material, remaining fixing material (RFM), apparent color and turbidity. The results revealed interesting theoretical relationships involving two families of bacteria (Carnobacteriaceae and Aeromonadaceae). Carnobacteriaceae revealed positive theoretical relationships with COD, BOD, nitrate, chloride, temperature, conductivity and apparent color and negative theoretical relationships with the OD. Positive theoretical relationships were shown between Aeromonadaceae and OD and nitrate, while this bacterial family showed negative theoretical...

Relevância:

50.00% 50.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Relevância:

50.00% 50.00%

Publicador:

Resumo:

As lipases (triacilglicerol acil hidrolases, E.C. 3.1.1.3) constituem uma classe de enzimas que catalisam a hidrólise de ligações ésteres dos triacilgliceróis de cadeia longa, operando na interface óleo/água. Em meios orgânicos, dependendo da quantidade de água, essas enzimas podem catalisar reações de esterificação e transesterificação, atuando como biocatalisadores da síntese de óleos e gorduras. As lipases destacam-se em processos industriais, nos quais são utilizadas como aditivos na produção de detergentes, de papel e celulose, na indústria de laticínios, de cosméticos, entre outros. As lipases microbianas são de maior interesse para aplicação em biotecnologia e em química orgânica, sendo necessária a prospecção de novas fontes de lipases com propriedades distintas. O presente trabalho avaliou a influência de diferentes meios de cultura, do tempo de cultivo, de fontes de carbono e sua concentração, de fontes de nitrogênio, agitação, pH e temperatura sobre a produção de lipase extracelular pelo fungo filamentoso Penicillium janthinellum, isolado de solo de região de Mata Atlântica. A avaliação das melhores condições de cultivo foi realizada através da análise da atividade enzimática, acompanhada pela determinação do íon ρ-nitrofenol liberado na hidrólise do substrato sintético ρ- nitrofenil palmitato. Os experimentos foram realizados em frascos de Erlenmeyer de 125mL contendo 25mL de meio de cultivo, inoculados com 1mL de suspensão contendo 107 conídios, e incubados a 28°C com agitação de 160 rpm e pH 5,5. Entre os quatro meios de cultura testados, o melhor resultado (0,476 ± 0,04 U/mL), com 5 dias de cultivo, foi verificado com o meio 2 composto por (g/L): bacto-peptona 5,0, extrato de levedura 1,0, NaNO3 0,5, KCl 0,5, MgSO4·7H2O 0,5, KH2PO4 2,0 e azeite de oliva 10,0)... (Resumo completo, clicar acesso eletrônico abaixo)

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Dois condicionadores químicos, a carboximetilcelulose, nas dosagens de 0,1% e 0,25% em relação ao peso do solo seco, e o silicato de sódio, de relação sílica-álcali igual a 3,2, a 0,6% e 1,2% em peso, foram pesquisados quanto aos seus efeitos sobre os índices físicos dos solos argiloso e barro arenoso empregados neste trabalho. Os dados obtidos foram estatisticamente analisados e os resultados permitiram que se chegassem a algumas conclusões. O tratamento 0,25% de carboximetilcelulose diminuiu o peso específico aparente seco e aumentou, consequentemente, o índice de vazios e porosidade dos solos estudados. O efeito dos tratamentos 1,2% de silicato de sódio e 0,1% de carboximetilcelulose sobre o peso específico aparente seco dos solos argilosos e barro arenoso, respectivamente, foi semelhante ao do tratamento 0,25% de carboximetilcelulose.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

This work evaluated the use of the Hildebrand/Hansen solubility parameters for selection of solvents for extraction of the organochlorine pesticides pp' DDT, pp' DDE, Aldrin and a-Endossulfan from soil using columns packed with Al2O3. The mixtures hexane:dichloromethane (7:3; v/v), hexane:acetonitrile (1:1; v/v), hexane:acetone (1:1; v/v) and pure hexane were chosen as extracting solutions. In the addition and recovery tests, different extraction solutions provided high recoveries percentages (>75%) with coefficients of variation below 15%. The recoveries are in agreement with the Hildebrand/Hansen parameters, demonstrating its applicability in the selection of extracting solution and in the replacement of toxic solvents, as dichloromethane

Relevância:

40.00% 40.00%

Publicador:

Resumo:

O objetivo deste trabalho foi avaliar a relação entre atributos micromorfológicos e físicos de um Latossolo Vermelho eutroférrico, sob cultivo de cana-de-açúcar. As amostras de solo foram coletadas nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, perfazendo um total de 100 pontos, nos horizontes A1 e AB. Os altos valores da densidade do solo, microporosidade e resistência do solo à penetração, e os baixos valores da macroporosidade, porosidade total e condutividade hidráulica do solo saturado, principalmente no horizonte AB, indicaram compactação confirmada pela análise de imagens (micromorfologia).

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Fifteen soil samples and four extradants (DTPA, Na 2EDTA, HCl and Mehlich 1) were used to study soil extraction methods for available zinc. Each extradant was studied in three soil:solution ratios (1:2, 1:4 and 1:10) and in three extraction periods in the ratio most frequently used. The zinc extracted by DTPA, Na 2EDTA and HCl was not affected by use of soil:solution ratios 1:2 and 1:4, but the amount extracted increased with the 1:10 ratio. In this relation, the variation coefficients increased. With Mehlich, no definite tendency was observed. The increase of extraction period for DTPA extractant, in 1:2 ratio, had little effect on the amount of zinc extracted and on the precision. As to Na 2EDTA extractant in 1:10 ratio, with the increase of extraction time, both increased. As to HCl and Mehlich, both in 1:4 ratio, the increase in extraction period had no effect on the amount of zinc extracted and no definite effect on the precision. Thus, the use of 1:2 ratio for DTPA and Na 2EDTA and 1:4 ratio for acid extractants is recommended. Concerning the period of extraction, 120 min should be used with DTPA and Na 2EDTA, 15 min with HCl and 5 min with Mehlich.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

This paper presents and discusses Ménard Pressuremeter test results used to predict bearing capacity of pounded piles installed in a tropical sandy soil. Fifteen pre-bored pressuremeter tests were carried out at the Experimental Research Site from Unesp - Bauru up to 15 m depth, one test per meter. Several laboratory and in situ tests were carried out in this research site as well as load tests on plates and on piles. Pressuremeter test results were firstly analyzed to determine geotechnical soil parameters based on empirical methods, emphasizing the estimative of the earth pressure coefficient at rest (K0). After that, bearing capacity prediction of pounded piles with 4 m, 7 m and 10 m were made and compared with test results from instrumented load tests. Pressuremeter test results allowed a very good estimative of bearing capacity for the pile with 4 m length and underestimated in 25,7% and 20,0% the bearing capacity for the pile with 7 and 10 m length, respectively. The back analysis of the test results suggests that the appropriate value for the bearing capacity factor for the tested soil-pile system on this soil is equal to 2.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The objective of this research was to study three methods of parameter determination for irrigation control under different tensions in common bean (Phaseolus vulgaris L.). The treatments were a combination of three methods of parameter determination for irrigation control (tensiometer, water retention curve, USWB Class A pan) with three soil water tensions (1:-30 kPa; 2:-60, kPa both for the whole plant cycle; 3:-60 kPa for the vegetative phase and -30 kPa for the reproductive phase). The experimental design was randomized blocks, factorial 32 with three replicates. Although no significant effect on water use efficiency was found, a tendency for increasing water use efficiency in treatments with tensions of -60 kPa at the vegetative phase and -30 kPa at the reproductive phase was observed in all methods of parameter determination for irrigation control. Water was saved as less irrigation was applied during the vegetative phase and more irrigation at the reproductive phase. No precipitation was observed from June to September 1995, leading to a high yield and therefore to a higher water use efficiency.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)