River
Mostrando 13-24 de 3215 artigos, teses e dissertações.
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13. DAILY RAINFALL DISAGGREGATION COEFFICIENTS FOR THE DOCE RIVER BASIN, BRAZIL: REGIONAL APPLICABILITY AND THE RETURN PERIOD INFLUENCE
ABSTRACT Alternative methods to the intensity-duration-frequency equations have been used for intense rainfall study in places with no pluviographic data. A pioneering study, by CETESB (1986), established rainfall disaggregation coefficients for Brazil; however, the use of these coefficients take into account neither the rainfall characteristics of the inter
Eng. Agríc.. Publicado em: 2021-04
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14. The invasive tropical tanner grass decreases diversity of the native aquatic macrophyte community at two scales in a subtropical tidal river
ABSTRACT The tropical tanner grass, Urochloa arrecta, is one of the worst aquatic plant invaders in Brazilian freshwater ecosystems. This study aimed to compare beds of macrophytes dominated and without U. arrecta in the Guaraguaçu River, a subtropical tidal river in South Brazil, to analyze effects that this invasive grass has on the biodiversity of native
Acta Bot. Bras.. Publicado em: 2021-03
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15. Different scales determine the occurrence of aquatic macrophyte species in a tropical stream
ABSTRACT Distributions of aquatic macrophyte species are commonly associated with water chemistry characteristics. However, other environmental factors that can lead to the occurrence of aquatic plants in lotic ecosystems, such as dynamic habitats linked to the surrounding landscape, have been underestimated. This study aims to evaluate landscape features th
Acta Bot. Bras.. Publicado em: 2021-03
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16. Limnological layers improve species distribution modeling of aquatic macrophytes at fine-spatial resolution
ABSTRACT Species distribution modeling (SDM) studies of aquatic macrophytes are still attached to methodological paradigms focused on terrestrial plants, such as the use of bioclimatic layers. Our goal was to evaluate the applicability of this paradigm based on a SDM study of Egeria densa, Pontederia crassipes, and Salvinia auriculata in the São Francisco r
Acta Bot. Bras.. Publicado em: 2021-03
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17. Interaction of Pb, Ni and Cd with Aquatic Humic Substances of Amazonian Blackwater Rivers
In this study, the extraction and characterization of aquatic humic substances (AHS) from two blackwater rivers in the Amazon basin was carried out in order to assess the seasonal effects in the AHS structure. In addition, an investigation of the complexing capacities (CC) of the structures containing the metal ions CdII, NiII and PbII was also done. The cha
J. Braz. Chem. Soc.. Publicado em: 2021-02
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18. TIME SERIES TRENDS OF STREAMFLOW AND RAINFALL IN THE SANTO ANTÔNIO RIVER BASIN, BRAZIL
ABSTRACT Detecting trends in streamflow and rainfall series can have great significance for proper water resource management. Thus, the objective of this study was to analyze the trends of historical streamflow and rainfall series using nonparametric statistical tests. A historical series of pluviometric and fluviometric gauges, which belong to the hydromete
Eng. Agríc.. Publicado em: 2021-02
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19. o-DGT Devices for the Determination of Emerging Contaminants in Aqueous Matrices
Samplers based on the diffusive gradients in thin films for organics (o-DGT) were developed and applied in Brazilian aqueous matrices for the determination of four emerging contaminants (EC): 4-octylphenol, 4-nonylphenol, triclosan, and bisphenol A. The OASIS HLB resin used as the binding phase presented a high sorption capacity and the extraction associated
J. Braz. Chem. Soc.. Publicado em: 2021-01
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20. NMR in Analysis of the Nutritional Value of Lipids from Muscles and Livers of Wild Amazonian Fishes with Different Eating Habits Over Seasonal Variation
Endogenous and environmental factors can influence the lipid contents of fishes among which, in the Amazon River, seasonal dynamics influences stand out. Herein, nine most consumed Amazonian fish species had their lipid composition evaluated in terms of effects of tissue, season and eating habits. Higher amounts of lipids were obtained from fish livers than
J. Braz. Chem. Soc.. Publicado em: 2020-12
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21. An Electrochemiluminescence Biosensor for the Determination of Mercury Ion via Dual-Amplification Strategy
A novel dual-signal amplificatory electrochemiluminescence (ECL) deoxyribonucleic acid (DNA) biosensor was designed for the determination of Hg2+. One amplification unit was gold nanoparticles (AuNPs) modified on a glassy carbon electrode, and the other was single-stranded DNA (ssDNA) (with amino at the 3’ terminal and thiol at the 5’ terminal) labeled w
J. Braz. Chem. Soc.. Publicado em: 2020-12
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22. Factors Predicting Heart Failure in Children Admitted to a Pediatric Emergency Ward in a Developing Country
Abstract Background Heart failure is an important cause of morbidity and mortality in children. Objective To determine the clinical characteristics of children with acute heart failure syndrome in the emergency ward of River state university teaching hospital, Nigeria and identify factors associated with poor outcomes. Methods This was an 18month retro
Int. J. Cardiovasc. Sci.. Publicado em: 2020-12
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23. APPLICABILITY OF THE SWAT HYDROLOGICAL MODEL IN THE MUCURI RIVER BASIN
ABSTRACT Land-use changes promote significant variations in streamflow regimes, and hydrological models allow studying their impacts. Based on this approach, this study aimed to assess the applicability of the SWAT model for different land-use scenarios and their respective impacts on the flow regime of the Mucuri River. The average monthly and daily water b
Eng. Agríc.. Publicado em: 2020-10
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24. Exploring Polypyrrole as Extraction Phase for Disposable Pipette Extraction Method for Multiclass Organic Micro-Pollutant Determination in River and Tap Water Using Gas Chromatography-Mass Spectrometry
The use of a polypyrrole (PPy) is described as an efficient extraction phase for disposable pipette extraction (DPX), in a fast and ruggedized analytical method for simultaneous determination of 18 organic micro-pollutants in water using gas chromatography-mass spectrometry (GC-MS). The DPX-blank pipettes were filled with PPy, a material produced through the
J. Braz. Chem. Soc.. Publicado em: 2020-10