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| Registros recuperados: 45 | |
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| Aminot, Alain; Kerouel, Roger; Birot, Dominique. |
| A version of the orthophthaldialdehyde-fluorescence ammonium determination for flow injection analysis (FIA) is presented here, with a view to its use for in situ, low-power consumption systems, Thus, the reaction temperature was limited to 30 degreesC and FIA was used in stop-Bow mode (3 min stop). The calibration is linear up to 50 mu mol l(-1), but concentrations up to 100 mu mol l(-1) can be measured. Repeatability is around 1% in the range of 0.5-4 mu mol l(-1) and the detection limit is about 0.03 mu mol l(-1) Over the salinity range of 5-35 (seawater practical salinity scale) the salt effect is almost negligible (within +/- 2%); and below salinity of 5 it increases to a maximum of -9% in fresh water compared to seawater. Hydrogen carbonate,... |
| Tipo: Text |
Palavras-chave: In situ; Fluorometry; Flow injection analysis; Determination; Ammonium. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1722.pdf |
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| Vargas,Gustavo; Donoso-Bravo,Andrés; Vergara,Christian; Ruiz-Filippi,Gonzalo. |
| Background: Industrial wastewaters with a high content of nitrogen are a relevant environmental problem. Currently, treatments to remove nitrogen are not efficient, so is necessary to develop alternative methods. The objective of this study is to investigate a consortium of microalgae - nitrifying, that due to the symbiosis between them could be an interesting alternative. Results: In this study, it was possible to obtain a consortium of nitrifying bacteria (NB) and microalgae (MA) capable of operating with low requirements of dissolved oxygen, using aerobic sludge from wastewater treatment plants. During the operation, this consortium presents removal percentages above 98% of ammonia, even at concentrations of DO of 0.5 mg O2 L-1. It is estimated that the... |
| Tipo: Journal article |
Palavras-chave: Ammonium; Consortium nitrifying-microalgae; Oxygen; Respirometry. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000500007 |
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| ANDRADE, S. R. M.; SANT'ANNA, R.; MOSQUIM, P. R.; CAMBRAIA, J.. |
| Visando a elucidar alguns aspectos do metabolismo do nitrogenio por plantas de Panicum maximum, estudaram-se os efeitos da proporcao NH +4/NO-3 na variacao do pH das solucoes nutritivas de tratamento, no acumulo de materia seca e na distribuicaoo de nitrogenio na planta. Para tal, as plantas foram cultivadas em camara de crescimento na solucao nutritiva (pH 5,5) completa, contendo nitrogenio somente na forma nitrica. Aos 25 dias depois da germinacao, as plantas foram submetidas a 100 ppm de nitrogenio fornecido nas formas nitrica e amoniacal ou amonical, nas seguintes proporcoes 0/100,25/75,50/50,75/25 e 100/0, durante quatro dias. O pH das solucoes nutritivas foi medido e corrigido diariamente. Os resultados demostraram que o pH aumentou na presenca... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Amonio; Absorcao de nitrogenio; Nitrogen uptake; Ammonium; Nitrate; Fisiologia vegetal: Nutricao mineral.; Capim Colonião; Cerrado; Fisiologia Vegetal; Nitrato; Nitrogênio; Panicum Maximum.; Plant physiology.. |
| Ano: 2001 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567073 |
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| Fernandes,Adalton Mazetti; Andrade,Gabriel José Massoni de; Souza,Emerson de Freitas Cordova de; Rosolem,Ciro Antonio. |
| Nitrification can lead to substantial losses of the applied N through nitrate leaching and N2O emission. The regulation of nitrification may be a strategy to improve fertilizer N recovery and increase its agronomic efficiency. The objective of this study was to evaluate the inhibiting capacity of nitrification in soil by Brachiaria species. The greenhouse experiment was conducted using pots with 10 dm³ of a Red Latosol sample. The treatments consisted of the cultivation of three forage species (Brachiaria brizantha, B. ruziziensis and B. decumbens) and four n rates (0, 100, 200, and 300 mg/pot), and the control (without plants). In the absence of the forage plants, all N fertilization levels raised the N-NO3- soil levels, as a result of nitrification. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonium; Nitrate; Nitrogen. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000500024 |
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| Collos, Y; Vaquer, A; Laabir, M; Abadie, Eric; Laugier, Thierry; Pastoureaud, Annie; Souchu, Philippe. |
| A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original approach is used to assess the relative contribution of several nitrogen sources (nitrate, nitrite, ammonium, urea) to growth of A. catenella by comparing nitrogen uptake rates to nitrogen-based growth rates estimated from dilution experiments during four blooms over a 4-year period (2001-2004) in Thau lagoon. Nitrate and nitrite contributed 0.1-14% and 0.1-5%... |
| Tipo: Text |
Palavras-chave: Uptake kinetics; Ammonium; Urea; Growth; Nitrogen; HAB; Alexandrium catenella. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6454.pdf |
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| ANDRADE, S. R. M.; SANT'ANNA, J.; MOSQUIM, P. R.. |
| O objetivo deste trabalho foi estudar os efeitos da nutricao nitrica e amoniacal na distribuicao de nitrato e na atividade in vitro da redutase do nitrato em plantas de capim coloniao ( Panicum maximum Jacq.). as plantas receberam 7 mM de nitrogenio nas forma N- NH4 +, N-NO3- ou combinadas nas seguintes proporcoes 0/100, 25/75, 50/50, 75/25 e 100/0. A extracao enzigmatica foi feita em Tris-HCI 50mM pH 7,5, EDTA 0,5 mM e b-mercaptoetanol 10mM, e para o ensaio utilizou-se 200 mmoles de Tris-HCI pH 7,5, 20 mmoles KNO3, 0,1 mmol NADH e 0,1 mL de Triton X-100 1% no volume final de 2,0 mL. A concentracao de nitrato foi levemente superior na parte aerea quando as plantas receberam ambas as formas de nitrogenio, e na raiz seta decresceu com o aumento da proporcao... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Assimilacao de nitrogenio; Amonio; Nitrogen assimilation; Nitrate; Ammonium; Fisiologia vegetal: Nutricao mineral.; Capim Colonião; Cerrado; Fisiologia Vegetal; Nitrogênio; Nitrato; Panicum Maximum.; Plant physiology.. |
| Ano: 2001 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567071 |
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| Garbin,Mário L.; Dillenburg,Lúcia R.. |
| The southern Brazilian highland plateau is a mosaic of two contrasting plant communities, Araucaria forests and grasslands, which differ in the relative abundances and spatial patterns of soil nitrate and ammonium. However, we still do not know the inorganic N preferences of one key species in this mosaic, Araucaria angustifolia, the dominant tree species in the Araucaria forests and an important tree species invading the adjacent grasslands. Growth responses measured in a greenhouse study demonstrated that the species prefers NH4+ over NO3- as an inorganic N source. When provided alone, NO3- induced N deficiency symptoms: increases in root: shoot ratio, root branching and leaf mass per area, thickening of the shoot apexes and decreased mass-based... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Araucariaceae; Ammonium; Inorganic nitrogen; Nitrate; Nitrogen deficiency. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400005 |
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| Bouchet, Vincent; Debenay, Vincent; Sauriau, Pierre-guy; Radford Knoery, Joel; Soletchnik, Patrick. |
| Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oléron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in oyster summer mortality, was monitored. Short-term hypoxia occurred in early June, in conjunction with a sudden rise in temperature. In mid-June, the ammonia content of sediment porewater increased, leading to potentially maximal flux towards overlying waters. Foraminiferal assemblages, particularly in the topmost layer, were altered. Ammonia tepida was the most tolerant to temperature increase and hypoxic... |
| Tipo: Text |
Palavras-chave: Marennes Oléron bay; Aquaculture; Crassostrea gigas; Intertidal; Ammonium; Hypoxia; Organic matter; Living benthic foraminifera. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2586.pdf |
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| Piva,Jonatas Thiago; Sartor,Laércio Ricardo; Sandini,Itacir Eloi; Moraes,Anibal de; Dieckow,Jeferson; Bayer,Cimélio; Rosa,Carla Machado da. |
| ABSTRACT Brazilian agriculture contributes significantly to nitrous oxide (N2O) and methane (CH4) emissions, so the understanding of such emissions at the field is crucial for mitigation strategies. This study quantified the impact of N application and sheep grazing on the N2O and CH4 emissions from a subtropical Ferralsol under an integrated crop-livestock (ICL) management system. In a long-term experiment in southern Brazil, gaseous fluxes were measured during a year-long cycle of ryegrass (Lolium multiflorum) plus oats (Avena sativa) winter pasture and a summer crop of common beans (Phaseolus vulgaris). Three rates of urea-nitrogen (0, 75, and 150 kg ha-1) were applied to the winter-pasture, which was subjected to two sheep grazing levels (continuously... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrate; Ammonium; Water filled pore space; Sheep. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100520 |
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| Haouari,Chiraz Chaffei; Nasraoui,Afef Hajjaji; Carrayol,Elisa; Lelendais,Maud; Ghorbel,Mohamed Habib; Gouia,Houda. |
| Glutamate metabolism and amino acid translocation were investigated in the control and cadmium stressed shoots of tomato (Solanum lycopersicum - 63/5 F1), using (15N) ammonium and (15N) glutamate tracers. Regardless of organ type, [15N] ammonium assimilation occurred via glutamine synthetase (EC 6.3.1.2), in the control and stressed plants, and it did not depend on glutamate dehydrogenase (EC 1.4.1.2). The [15N] ammonium and ammonium accumulation patterns support the role of glutamate dehydrogenase in the deamination of [15N] glutamate to provide 2-oxoglutarate and [15N] ammonium. In the presence of cadmium, excess [15N] ammonium was incorporated into asparagine, which served as an additional detoxification molecule. In the presence both of methionine... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonium; Glutamate dehydrogenase; Methionine sulfoximine; 15N-NH4+. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100004 |
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| Collos, Y; Descolas Gros, C; Mornet, Francoise. |
| During parallel sampling of seawater samples in bottles and in free water (1000-2000 m(3) clay ponds), we have measured phytoplankton biomass, Ribulose biphosphate carboxylase (Rubisco), phosphoenol pyruvate carboxylase, and phosphoenol pyruvate carboxykinase activities and major nutrients (ammonium, nitrate, phosphate, silicate). This was done in two ecosystems: one with high grazing pressure due to the presence of oysters and another with low grazing pressure (no oysters). In the ecosystem subjected to high grazing pressure, anaplerotic carbon fixation by phytoplankton in free water was higher in the light period and could represent 25% of total carbon fixation. Incubating samples in bottles led to a major increase in Rubisco activity (80% in 3 h)... |
| Tipo: Text |
Palavras-chave: Grazing; Carboxylases; Carbon assimilation; Anaplerotic; Ammonium. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-6437.pdf |
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| Andriolo,Jerônimo L; Godoi,Rodrigo dos S; Cogo,Clarissa M; Bortolotto,Orcial C; Luz,Gean L da; Madaloz,José Carlos. |
| Lettuce plants, cv. Vera, were grown at five NH4+:NO3- ratios in the nutrient solution in a 0.15 m deep sand growing bed. A standard nutrient solution was used, with the composition of, in mmol L-1, 11.0 NO3-; 1.5 H2PO4-; 6.5 SO4--; 7.5 Ca++; 10.0 K+ and 1.5 Mg++, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0.05 Cu; 0.50 B; 0.04 Mo, and 4.82 chelate Fe. Ammonium nitrate was used to supply NH4+ concentrations of 2.5; 5; 7.5 and 10 mmol L-1, reaching NH4+:NO3- ratios of 0:11 (T1); 2.5:13.5 (T2); 5:16 (T3); 7.5:18.5 (T4) and 10:21 mmol L-1 (T5) as treatments. A completely randomized experimental design was used, with four replications and 20 plants per plot. Four plants of each plot were harvested at 25 days after planting, to determine shoot and root dry mass, shoot... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactuca sativa; Fertigation; Hydroponics; Ammonium. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362006000300016 |
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| Bedier, Edouard; Knoery, Joel Radford; Fleury, Pierre-gildas; Quiniou, Francoise; Langlade, Aime; Cozic, Amandine; Delesmont, Edith; Delesmont, Régis; Caisey, Xavier; Lecureuil, Laetitia. |
| The phenomenon of summer mortalities of the Pacific cupped oyster Crassostrea gigas is observed in France since the beginning of the 90's. These mortalities are classically associated to younger stages and summer temperatures and occur during the reproduction period of the animal. The studies undertaken during the project Morest (2001-2005), showed that a number of biological and environmental risks, the interaction of them induces lethal stresses for animals in physiological weakness, exists in summer. Among these risks, that which is withstood by the oysters bred close to the sediment proved to be significant in intertidal areas. In Quiberon bay (southern Brittany, France), the breeding practices of sowing oysters in deep water is thus likely to expose... |
| Tipo: Text |
Palavras-chave: Huître; Crassostrea gigas; Mortalité; Sédiment; Composé réduit; Flux; Sulfure; Ammonium; Oyster; Crassostrea gigas; Mortality; Sediment; Reduced compound; Flux; Sulphide; Ammonia. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00108/21956/19550.pdf |
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| Registros recuperados: 45 | |
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