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| Registros recuperados: 25 | |
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| ROSA-CAMPOS, A. A.; ROCHA, J. E. da S.; BORGO, L. A.; SILVA, M. S. da. |
| Resumo: O mel brasileiro é produzido principalmente por abelhas africanizadas a partir do néctar ou da secreção das plantas e, devido às suas características genéticas dessas espécies de abelhas, dispensa o uso de antibióticos e pesticidas, como acaricidas e fungicidas. A composição das amostras de méis está intimamente relacionada com o tipo de florada utilizada por estas abelhas para a elaboração do produto final. Um dos componentes de grande importância são os minerais presentes no mel que representam de 0,02% a 1%. Dentre estes minerais observamos os chamados metais pesados, que podem indicar tanto a origem geográfica do mel quanto o nível de poluição ambiental por estes metais. Logo, faz-se necessário a pesquisa da presença ou não de metais pesados... |
| Tipo: Anais e Proceedings de eventos |
Palavras-chave: Abelha; Mel; Metal pesado; Chumbo; Cobre; Cromo; Níquel; Zinco; Honey bees; Honey; Heavy metals; Lead; Copper; Chromium; Nickel; Zinc. |
| Ano: 2013 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/977384 |
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| VERGARA, C.; ARAUJO, K. E. C.; URQUIAGA, S.; SANTA-CATARINA, C.; SCHULTZ, N.; ARAUJO, E. da S.; BALIEIRO, F. de C.; XAVIER, G. R.; ZILLI, J. E.. |
| An understanding of the interaction between rice and dark septate endophytic (DSE) fungi, under green fertilization, may lead to sustainable agricultural practices. Nevertheless, this interaction is still poorly understood. Therefore, in this study, we aimed to evaluate the accumulation of macro- and micronutrients, dry matter, and protein and N recovery efficiency from Canavalia ensiformis (L.)-15N in rice inoculated with DSE fungi. An experiment under greenhouse conditions was conducted in a randomized complete block design comprising split-plots, with five replicates of rice plants potted in non-sterilized soil. Rice (Piauí variety) seedlings were inoculated with DSE fungi, A101 and A103, or left uninoculated (control) and transplanted into pots... |
| Tipo: Artigo de periódico |
Palavras-chave: Dark septate endophytic fungi; DSE fungi; Canavalia Ensiformis; Oryza Sativa; Níquel; Ferro; Manganês; Grão; Arroz; Fungo; Nickel; Iron; Manganese; Grains; Rice; Fungi. |
| Ano: 2018 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1091716 |
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| Alpat,Senol; Alpat,Sibel Kilinç; Çadirci,Bilge Hilal; Özbayrak,Özge; Yasa,Ihsan. |
| Circinella sp. was employed as a biosorbent for removal of Ni(II) from aqueous solution. The biosorption kinetics and isotherms were investigated. The effect of several parameters, such as biosorbent dosage, contact time, initial concentration, pH and temperature, on biosorption process was evaluated. The kinetic studies indicated that the biosorption followed pseudo-second order kinetic model. Biosorption behaviour of Ni(II) on Circinella sp. was expressed by both Langmuir and Freundlich isotherms. The equilibrium data fit better to the Langmuir model compared to the Freundlich model in concentration range studied (1.0-3.0 mM). The thermodynamic parameters (ΔG0, ΔH0 and ΔS0) were also determined, and it was found that the Ni(II)... |
| Tipo: Journal article |
Palavras-chave: Biosorption; Circinella sp; Equilibrium; Kinetic; Nickel. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000500004 |
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| Mariano-da-Silva,Samuel; Brait,Joys Dias de Assis; Angeloni,Luiz Henrique Poleto; Mariano-da-Silva,Fabiana Maria de Siqueira; Leite,César Augusto Oliveira; Braga,Paula. |
| Sugar cane juice containing 12% (w.w -1) of total reducing sugars and 0.0 to 5.0 mmol of nickel L-1, with pH ranging from 3.5 to 6.5, was inoculated with Fleischmanns yeast (Saccharomyces cerevisiae) (10% w.w -1). Six hours after fermentation, the yeasts cellular viability and trehalose content were evaluated. The resulting must was centrifuged and the raw yeast was analyzed by atomic absorption spectroscopy to evaluate the intracellular levels of calcium, copper, iron, magnesium, manganese, nickel, phosphorus, potassium, sulfur and zinc. The intracellular levels of iron, magnesium and calcium were affected and the yeasts susceptibility to nickel was enhanced by the decrease in pH. The yeasts growth was not affected by nickel at high pH, but the toxic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nickel; Mineral composition; Saccharomyces cerevisiae; Yeast. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612007000300013 |
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| CORREIA, F. H.; CURADO, I. C.; GHESTI, G. F.; BRAGA, P. R. S.; MARINHO, A. L. A.; MATTOS, L. V.; NORONHA, F. B.; SOARES, I. P.; SCHULTZ, E. L.. |
| Ni-Mg-Al mixed oxides derived from hydrotalcite-like compounds were prepared by a co-precipitation technique, calcined at two temperatures (550 °C and 750 °C) and applied to steam reforming of simulated biogas. Three nickel contents were used in the catalysts (5, 10 and 15%). The catalysts were characterized by X ray fluorescence, N2 sorption techniques, X-ray diffraction and temperature-programmed desorption of CO2. Steam reforming experiments using simulated biogas were carried out at atmospheric pressure and 750 °C, using S/C ratio of 3.2. Catalysts calcined at 750 °C showed nickel and magnesium aluminate phases, resulting in lower density of basic sites. Conversion of CH4 ranged from 97.4 to 99.6% while CO2 conversion ranged from 58.5 to 63.5%. The... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Steam reforming; Mixed oxides; Biogás; Níquel; Oxido; Steam; Nickel; Catalysts; Oxides. |
| Ano: 2020 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1124168 |
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| Shweta,Mishra; Agrawal,S.B.. |
| The impact of supplemental UV-B (sUV-B) radiation and heavy metals: Cd (68 µmol.kg-1 soil) and Ni (68 µmol.kg-1 soil) singly and in combination was studied on photosynthetic and non-photosynthetic pigments, metabolites, enzyme activities, biomass accumulation and the net primary productivity of spinach (Spinacia oleracea L. var. All Green), a common leafy vegetable plant. Both the stresses individually and in combination resulted in the reduction of photosynthetic pigments, ascorbic acid, and catalase activity, whereas a reverse trend was observed for anthocyanin, flavonoids and proline content, lipid peroxidation and peroxidase activity. The interactive effects of both the stresses were, however, less than additive. Combined treatment of sUV-B + Cd was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spinaicia oleracea; Biomass; Cadmium; Enzymes; Nickel; Pigments; Ultraviolet-B. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200007 |
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| Ratie, G.; Quantin, C.; Jouvin, D.; Calmels, D.; Ettler, V.; Sivry, Y.; Cruz Vieira, L.; Ponzevera, Emmanuel; Garnier, J.. |
| Nickel isotope ratios were measured in ores, fly ash, slags and FeNi samples from two metallurgical plants located in the Goiás State, Brazil (Barro Alto, Niquelândia). This allowed investigating the mass-dependent fractionation of Ni isotopes during the Ni-laterite ore smelting and refining. Feeding material exhibits a large range of δ60Ni values (from 0.02 ± 0.10 ‰ to 0.20 ± 0.05 ‰, n=7), explained by the diversity of Ni-bearing phases, and the average of δ60Nifeeding materials was found equal to 0.08 ± 0.08‰ (2SD, n=7). Both δ60Ni values of fly ash (δ60Ni = 0.07 ± 0.07‰, n=10) and final FeNi produced (0.05 ± 0.02 ‰, n=2) were not significantly different from the feeding materials ones. These values are consistent with the very high production yield of... |
| Tipo: Text |
Palavras-chave: Nickel; Isotope; Smelting; Refining; Source; Soil. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00278/38961/37501.pdf |
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| Ratie, G.; Jouvin, D.; Garnier, Julien; Rouxel, Olivier; Miska, S.; Guimaraes, E.; Cruz Vieira, L.; Sivry, Y.; Zelano, I.; Montarges-pelletier, E.; Thil, F.; Quantin, C.. |
| Although Ni isotopes have been shown to be significantly fractionated in terrestrial samples, their use in continental environmental studies has not yet been evaluated. The present study focuses on an ultramafic (UM) massif (Barro Alto, Goias, Brazil) because such areas are naturally rich in Ni. We present developed lateritic weathering profiles. The goal of the study is to evaluate the potential of using Ni isotopes in environmental continental studies by combining its isotopic signature with mineralogy, in order to better understand the geochemical cycling of Ni in UM settings during weathering. As such, Ni isotope values were measured in samples from the Barro Alto UM complex in the main stages of the lateritic weathering profile of UM rocks, including... |
| Tipo: Text |
Palavras-chave: Nickel; Isotope; Weathering; Mineralogy; Soil. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36553/35098.pdf |
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| Gueguen, Bleuenn; Rouxel, Olivier; Ponzevera, Emmanuel; Bekker, Andrey; Fouquet, Yves. |
| Although initial studies have demonstrated the applicability of Ni isotopes for cosmochemistry and as a potential biosignature, the Ni isotope composition of terrestrial igneous and sedimentary rocks, and ore deposits remains poorly known. Our contribution is fourfold: (a) to detail an analytical procedure for Ni isotope determination, (b) to determine the Ni isotope composition of various geological reference materials, (c) to assess the isotope composition of the Bulk Silicate Earth relative to the Ni isotope reference material NIST SRM 986 and (d) to report the range of mass-dependent Ni isotope fractionations in magmatic rocks and ore deposits. After purification through a two-stage chromatography procedure, Ni isotope ratios were measured by MC-ICP-MS... |
| Tipo: Text |
Palavras-chave: Nickel; Stable isotopes; MC-ICP-MS; Geological reference materials; Bulk Silicate Earth; Abiotic fractionation. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00159/27069/25332.pdf |
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| Prasad,Majeti Narasimha Vara. |
| Nickeliferous soils are invaded predominantly by members of the Brassicaceae, Cyperaceae, Cunoniaceae, Caryophyllaceae, Fabaceae, Flacourtiaceae, Euphorbiaceous, Lamiaceae, Poaceae and Violaceae, and many of these plants are metal tolerant. About 300 Ni hyperaccumulating plants been identified. These members exhibit unusual appetite for toxic metals and elemental defense. Hyperaccumulators provide protection against fungal and insect attack. Investigations suggested that Ni-hyperaccumulation has a protective function against fungal and bacterial pathogens in Streptanthus polygaloides and Thlaspi montanum. Significance of nickelophilous plants and their significance in phytotechnologies are discussed in this paper. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heavy metal; Hyperaccumulators; Nickel; Phytomanagement; Tolerance. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100010 |
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| Registros recuperados: 25 | |
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