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| Registros recuperados: 35 | |
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| LIMA NETO,IRAN E.. |
| Abstract: Field surveys and integral modelling were carried out to study the effect of bubble plumes on the flow hydrodynamics and the time-evolution of water temperature profiles in a shallow lake with maximum depth of about 4 m. Then, model simulations were performed to verify the feasibility of destratification of ten water-supply reservoirs with capacities of 10-2,000 hm3. Finally, hydrological modelling was conducted to assess the impact of destratification on evaporation suppression and its effects on reservoir yield. The results indicate that net temperature reductions of the order of 1.0°C can be obtained, which corresponds to evaporation suppressions of approximately 10%. In turn, this resulted in increases in the regulated flow of 2-12% that... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aeration; Evaporation; Bubble plumes; Lakes; Stratification; Water yield. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000500904 |
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| Marques,Pedro Rocha; Barcellos,Júlio Otávio Jardim; Dill,Matheus Dhein; Dias,Eduardo Antunes; Azevedo,Eduardo Vaz Torres; Lampert,Vinícius do Nascimento; McManus,Concepta Margaret. |
| The aim of this experiment was to identify improvement demands for farms with different levels of competitiveness in the west of Rio Grande do Sul state, Brazil. A total of 63 owners of large farms were interviewed (farms with an area greater than 900ha) by applying a semi-structured questionnaire, guided by four drivers: technology (TEC), management (MAN), market relations (MR) and the institutional environment (IE).It was used the Statistical Analysis System 9.2 software to perform the cluster analysis and identify farmers' characteristics. Three random clusters with different levels of competitiveness were observed: low competitiveness level (LCL), middle competitiveness level (MCL) and high competitiveness level (HCL). The 29 variables (sub factors)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cluster; Level of impact; Management; Ranking; Stratification. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015000300480 |
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| Poletto,Tales; Muniz,Marlove Fátima Brião; Poletto,Igor; Stefenon,Valdir Marcos; Maciel,Caciara Gonzatto; Rabusque,Jéssica Emilia. |
| ABSTRACT: This study evaluated the efficiency of methods to overcome seed dormancy in different storage periods in the production of pecan seedlings. Seeds were submitted to the following treatments: T1, T4 and T7 - control treatments (seeds with no treatment, stored at room temperature for 30, 60 and 90 days, respectively), T2, T5 and T8 - stratification (seeds were distributed in boxes with wet sand maintained at a temperature of 4°C for 30, 60 and 90 days, respectively), T3, T6 and T9 - scarification + stratification (seeds scarified with sandpaper n.80 and stratified by 30, 60 and 90 days, respectively), in completely random experimental design. Plant height, stem diameter, number of leaves, full emergence and emergence speed index (ESI) were evaluated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Scarification; Stratification; Emergence; Carya illinoinensis. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001101980 |
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| Шумакова, Г. В.. |
| Представлены результаты анализа многолетних данных по распределению общей численности бактериопланктона в северо-западной части Черного моря в период с 1971 по 1997 гг. Более высокая плотность бактериального населения приурочена к приустьевым районам, из которых летом выделяется Дунайский (4,43 х 106 клеток/мл), а весной и осенью - Днепровско-Бугский (3,58 – 4,17 х 106 клеток/мл). Накопление бактериальной биомассы в приустьевых районах было обусловлено обилием речного стока и хорошо выраженной вертикальной стратификацией вод. В тёплые месяцы бактериопланктон концентрировался в верхнем перемешанном слое, как в открытой части моря, так и в приустьевых районах. Приводятся карты пространственного распределения бактериопланктона на поверхности в... |
| Tipo: Journal Contribution |
Palavras-chave: Stratification; Stratification; Http://aims.fao.org/aos/agrovoc/c_7438. |
| Ano: 2002 |
URL: http://repository.ibss.org.ua/dspace/handle/99011/412 |
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| Menesguen, Alain; Cugier, Philippe; Loyer, Sophie; Vanhoutte Brunier, Alice; Hoch, Thierry; Guillaud, Jean-francois; Gohin, Francis. |
| The general trend in ecosystem modelling is to improve the spatial resolution by shifting from rough box-models to fine 3D models. Despite the continuous speeding-up of computing, 3D models involving numerous state variables may remain intractable, especially for parameter calibration, when processes with long half-life periods (i.e, from years to decades) are introduced, such as the behaviour of organic matter in sediment and population dynamics of benthic species. In these cases, a first approach can be provided by fast-running box-models, if they take into account the most crucial hydrodynamic properties of the system. In a macrotidal shelf sea such as the English Channel, the long-term horizontal transport can be summarized by the tidal residual... |
| Tipo: Text |
Palavras-chave: English Channel; Stratification; Diatom/dinoflagellate succession; 3D model; Layered box model. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2315.pdf |
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| Grasso, Florent; Le Hir, Pierre. |
| Estuaries are subject to extensive morphological changes through human activities, such as deepening and narrowing via dredging and channelization. The estuary sediment load, characterised by the estuarine turbidity maximum (ETM), can severely increase in response to channel deepening, shifting the estuary from a natural to hyperturbid state. The main processes driving the estuarine circulation, hydrology and sediment dynamics are relatively well known. However, their relative influence on suspended sediment concentration (SSC), as well as their role in the transition toward hyperturbid estuaries, is still a subject of debate. Therefore, this study aims at investigating the relative contribution of key estuarine drivers (gravitational circulation and tidal... |
| Tipo: Text |
Palavras-chave: Estuary deepening and narrowing; Sediment dynamics; Turbidity maximum; Tidal asymmetry; Stratification; Numerical modelling; Morphological changes. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00479/59046/65965.pdf |
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| Feucher, Charlene; Maze, Guillaume; Mercier, Herle. |
| In the north Atlantic subtropical gyre, the oceanic vertical structure of density is characterized by a region of rapid increase with depth. This layer is called the permanent pycnocline because this density feature is observed throughout the year. The pycnocline is the transition layer between light, low-latitude, surface water masses which are ventilated every winter when penetrated locally by the mixed layer and dense, deeper water masses whose properties are set in the high latitudes and circulate equatorward. In-situ data from the Argo array provide temperature/salinity profiles allowing the characterization in space and time of the permanent pycnocline. We thus developed a new method to characterize its depth, thickness and thermohaline... |
| Tipo: Text |
Palavras-chave: Argo; Quality Control; Pattern; Clustering; North Atlantic; Subtropical gyre; Stratification. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00242/35315/33838.pdf |
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| Caumette, P. |
| In the deepest parts of the estuarine region of Ebrie Lagoon (Abidjan Africa, (5 degree N, 4 degree W) stratified conditions have been observed during the rainy season (May to Nov.), owing to salinity differences between oxic and anoxic layers. At the interface, 3-4 m depth, phototrophic bacteria (Chromatium, Chlorobium and Pelodictyon ) developed, forming a brown layer due to their different pigments. Their production has been estimated at 41% of the total photosynthetic production during high stratification (Sep. 1981) and their biomass was used by the copepod population for 40 to 60% of its diet. During the dry season, the water column became homogeneous and oxygen was detected to 6m depth. The brown layer of phototrophic bacteria disappeared, as well... |
| Tipo: Text |
Palavras-chave: Chlorobium; Chromatium; Primary production; Photosynthesis; Estuaries; Seasonal variations; Plankton; Stratification; Vertical distribution; Bacteria; Coastal lagoons; Trophic relationships; Biomass. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-957.pdf |
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| Marr, Julene P.; Carter, Lionel; Bostock, Helen C.; Bolton, Annette; Smith, Euan. |
| In situ measurements of Mg/Ca, Zn/Ca, Mn/Ca, and Ba/Ca in Globigerinoides bulloides and Globigerina ruber from southwest Pacific core top sites and plankton tow are reported and their potential as paleoproxies is explored. The modern samples cover 20 degrees of latitude from 34 degrees S to 54 degrees S, 7-19 degrees C water temperature, and variable influence of subantarctic (SAW) and subtropical (STW) surface waters. Trace element signatures recorded in core top and plankton tow planktic foraminifera are examined in the context of the chemistry and nutrient profiles of their modern water masses. Our observations suggest that Zn/Ca and Mn/Ca may have the potential to trace SAW and STW. Intraspecies and interspecies offsets identified by in situ... |
| Tipo: Text |
Palavras-chave: Mg; Ca; Mn; Ca; Ba; Ca; Zn; Ca; Southwest Pacific Ocean; Globigerina bulloides; Globigerinoides ruber; Surface ocean; Stratification; Temperature; Nutrient. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37528/35765.pdf |
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| Feucher, Charlene; Maze, Guillaume; Mercier, Herle. |
| A global reference state of the subtropical mode waters and permanent pycnoclines properties for the 2000‐2015 period is presented. The climatology is obtained from a pattern recognition algorithm applied to stratification profiles from the Argo global array. The stratification features are identified as permanent upper ocean pycnostad and pycnocline even when the seasonal pycnocline is developed. The climatology shows that both Northern Hemisphere subtropical gyres have a qualitatively very similar stratification structure. The permanent pycnocline in the North Atlantic and North Pacific show two deep centers colocated with thick subtropical and subpolar mode waters. These centers coincide with modes in the density and stratification space. These deep... |
| Tipo: Text |
Palavras-chave: Subtropical gyre; Pycnocline; Argo; Global ocean; Stratification. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00480/59176/61817.pdf |
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| Perrot, Laurie; Gohin, Francis; Ruiz-pino, Diana; Lampert, Luis; Huret, Martin; Dessier, Aurelie; Malestroit, Pascale; Dupuy, Christine; Bourriau, Paul. |
| Coccolithophore blooms occur regularly from April to June in the Bay of Biscay where they have been observed for many years from ocean-colour imagery thanks to the ability of their calcite plates to scatter light. They are easily depicted on interpolated images of non-algal Suspended Particulate Matter (SPM) derived from satellite reflectance data in May, at the time of the PELGAS (PELagique GAScogne) annual surveys. Over the springs 2012 to 2015, the PELGAS surveys provided in-situ data on the turbidity throughout the water column and on the hydrological environment prevailing during the blooms in the vicinity of the continental shelf break. The satellite-derived SPM in the area of coccolithophore blooms was closely related to measured turbidity in the... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Ocean colour; Suspended particulate matter; Turbidity; Coccoliths; Stratification. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52790/53689.pdf |
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| Vigneau, Joel; Mahevas, Stephanie. |
| Measuring fish on a market or on board a vessel is the most common action taken by biologists all around the world to gather data for stock assessment. The samples coming from this kind of survey are of vector type and are not straightforward to analyse and compare. This paper proposes a generic tool that enables to investigate in any multinomial like sampling scheme. The use of this tool will be discussed based on examples from two different sampling designs. One is a sampling of commercial market categories and the other is a métier based sampling. The research of outliers, misallocated samples or potential bias, the stratification and the analysis of within and between strata variance will be discussed with the objective of constructing the best... |
| Tipo: Text |
Palavras-chave: Stratification; Sampling design; Length structure; Market sampling. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-2698.pdf |
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| Registros recuperados: 35 | |
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