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| Registros recuperados: 11 | |
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| Goeyens, L.; Kindermans, N.; Yusuf, M.A.; Elskens, M.. |
| Several earlier studies underpin the important role of dissolved organic matter and more particularly urea in phytoplanktonic nitrogen uptake fluxes. Generally, the determination of urea concentrations relies on the formation of an imidazolone-thiosemicarbizide complex, a complexation which requires very accurate temperature control when carried out at high temperature. It is also possible, however, to obtain reliable results with a room temperature procedure. The measured abundances for both complexation at high temperature (85 degree C, 20 min) and at ambient temperature (22 degree C, 72 h) are closely comparable. Lower values are observed for temperatures <10 degree C though. Moreover, a comparison of both techniques reveals similar precision... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dissolved organic carbon; Sea water; Temperature; Urea; Water analysis. |
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7858 |
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| Aminot, Alain; Kerouel, Roger. |
| Dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) measured in deep profiles in the N-E Atlantic and in the N-W Mediterranean in the period 1984-2002 are described. After accurate validation, they show close agreement with those previously published. Classic profiles were obtained, with concentrations decreasing in deep waters. In the Mediterranean and in the Atlantic comparable concentrations were found in the 1500-2000 m waters, 44-46 mumol 1(-1) DOC, 2.6-2.8 mumol 1(-1) DON and 0.02-0.03 mumol 1-1 DOP. In the surface layers, DOC concentrations were higher, but DON and DOP concentrations lower, in the Mediterranean than in the Atlantic, leading to higher element ratios in the Mediterranean. In autumn,... |
| Tipo: Text |
Palavras-chave: N W Mediterranean; N E Atlantic; Mineralization; Non refractory; Refractory; Dissolved organic phosphorus; Dissolved organic nitrogen; Dissolved organic carbon. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-472.pdf |
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| Pivetta,Laércio Augusto; Castoldi,Gustavo; Pivetta,Laerte Gustavo; Maia,Suelen Cristina Mendonça; Rosolem,Ciro Antonio. |
| ABSTRACT Since there is no consensus on phosphogypsum (PG) rates to be used in agriculture, a better understanding of its effects on the soil solution is needed. Cotton root growth was evaluated as related to Al and Ca activity in soil solution affected by PG. The experiment was carried out in rhizotrons filled with30∙dm–3 of soil. PG rates were estimated by multiplying the soil clay content by 0.0, 1.5, 3.0, 6.0 and 12.0, and it was mixed to the sub-soil.In the upper soil layer, limestone was applied. After 90 days, samples were taken for analysis, and cotton was planted. After27 days, plants were harvested. PG increased soil pH and decreased Al content and activity. Without PG, dissolved organic carbon concentration was high in the soil solution, which... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aluminum; Dissolved organic carbon; Soil chemistry. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052019000200264 |
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| Breitbarth, E.; Achterberg, E. P.; Ardelan, M. V.; Baker, A. R.; Bucciarelli, E.; Chever, F.; Croot, P. L.; Duggen, S.; Gledhill, M.; Hassellov, M.; Hassler, C.; Hoffmann, L. J.; Hunter, K. A.; Hutchins, D. A.; Ingri, J.; Jickells, T.; Lohan, M. C.; Nielsdottir, M. C.; Sarthou, G.; Schoemann, V.; Trapp, J. M.; Turner, D. R.; Ye, Y.. |
| Based on an international workshop (Gothenburg, 14-16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas. |
| Tipo: Text |
Palavras-chave: Sub-arctic pacific; Dissolved organic carbon; Field flow fractionation; Phytoplankton community structure; Cathodic stripping voltammetry; Continuous culture system; Export experiment crozex; Eastern north atlantic; Light co-limitation; Southern ocean. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00205/31606/30034.pdf |
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| Gimenes, Karen Zauner; Universidade Federal de São Carlos; Leite-Rossi, Luciene Aparecida; Universidade Federal de São Carlos; Cunha-Santino, Marcela Bianchessi; Universidade Federal de São Carlos; Bianchini Junior, Irineu; Universidade Federal de São Carlos; Trivinho-Strixino, Susana; Universidade Federal de São Carlos. |
| The aim of this study is to evaluate the kinetics of aerobic decomposition of Saccharum officinarum and Talauma ovata leaves. For each species, decomposition chambers (leaves and water) were set up, which were maintained under controlled conditions. Each sampling day (1, 7, 15, 30, 39, 58, 72 and 90 days), the concentrations of total organic carbon, pH and electrical conductivity (EC) were determined in the dissolved fraction, while the mass and cell wall fractions (CWF) were determined in the particulate fraction. The pH stabilization of the chambers with T. ovata and S. officinarum leaves occurred in alkaline (ca. 8 - 8.5) and close to the neutrality (ca. 7 - 7.5) environment, respectively. The EC values were on average 1.6 times higher in incubations... |
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Palavras-chave: 2.05.00.00-9 riparian zone; Mass loss; Mineralization; Dissolved organic carbon; Particulate organic carbon 2.05.00.00-9. |
| Ano: 2012 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/9396 |
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| Gmach,Maria Regina; Cherubin,Maurício Roberto; Kaiser,Klaus; Cerri,Carlos Eduardo Pellegrino. |
| ABSTRACT: In tropical regions, climate conditions favor fast decomposition of soil organic matter (SOM), releasing into the soil organic composts in solid, liquid, and gaseous forms with variable compositions. Dissolved organic matter (DOM), a complex mixture of thousands of organic compounds, is only a small fraction of the decomposition products; however, it is highly mobile and reactive to the soil. Therefore, DOM play a key role in soil aggregation (formation of organometallic complexes), energy source for microorganisms, as well as C storage, cycling, and provision of plant-available nutrients. DOM multifunctionality to sustain soil functions and important ecosystem services have raised global scientific interest in studies on DOM fractions. However,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brazil; Dissolved organic carbon; Agricultural soils; Tropical soils. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000301800 |
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| Ghiglione, J. F.; Palacios, C.; Marty, J. C.; Mevel, G.; Labrune, C.; Conan, P.; Pujo-pay, M.; Garcia, N.; Goutx, M.. |
| Bacterioplankton plays a central role in energy and matter fluxes in the sea, yet the factors that constrain its variation in marine systems are still poorly understood. Here we use the explanatory power of direct multivariate gradient analysis to evaluate the driving forces exerted by environmental parameters on bacterial community distribution in the water column. We gathered and analysed data from a one month sampling period from the surface to 1000m depth at the JGOFS-DYFAMED station (NW Mediterranean Sea). This station is characterized by very poor horizontal advection currents which makes it an ideal model to test hypotheses on the causes of vertical stratification of bacterial communities. Capillary electrophoresis single strand conformation... |
| Tipo: Text |
Palavras-chave: Free living bacteria; Ribosomal RNA genes; Strand conformation polymorphism; Flame ionization detection; Dissolved organic carbon; 16S RDNA; Microbial diversity; Lipid classes; Phytoplankton dynamics; Multivariate analyses. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00208/31974/30409.pdf |
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| Registros recuperados: 11 | |
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