Institution
Simón Bolívar University
Education•Caracas, Venezuela•
About: Simón Bolívar University is a education organization based out in Caracas, Venezuela. It is known for research contribution in the topics: Population & Crystallization. The organization has 5912 authors who have published 8294 publications receiving 126152 citations.
Topics: Population, Crystallization, Nucleation, Differential scanning calorimetry, Context (language use)
Papers published on a yearly basis
Papers
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TL;DR: In this article, a new sample preparation procedure for elemental characterization is proposed, involving the acid extraction of the analytes from crude samples by means of an ultrasonic bath, avoiding the required digestion of samples in vegetable tissue analysis.
37 citations
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TL;DR: In this article, the invariant Finsler metric is induced by the quotient norm of a C ∗ -subalgebra A modulo the unitary group of A/B.
37 citations
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TL;DR: The respective patterns of development of the two species have been compared, with reference to such parameters as egg size and number, duration and number of larval stages, and body length of the first zoea.
Abstract: Summary In Venezuela, M. jelskii and M. amazonicum are both found living in fresh waters and sometimes share the same habitat. The respective patterns of development of the two species have been compared, with reference to such parameters as egg size and number, duration and number of larval stages, and body length of the first zoea. Development of M. jelskii exhibits features characteristic of fresh water species, whereas that of M. amazonicum has features usually associated with brackish water species.
37 citations
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TL;DR: In this paper, a study involved measurements of the longitudinal wave velocity, attenuation and spectral analysis of AISI 304 stainless steels exposed to sensitization and carbide solution heat treatment employing ultrasonic testing have been evaluated.
Abstract: Specimens of AISI 304 stainless steels exposed to sensitization and carbide solution heat treatment employing ultrasonic testing have been evaluated. The study involved measurements of the longitudinal wave velocity, attenuation and spectral analysis. Despite the large size difference between the ultrasonic wave length and the precipitated carbides, the results showed a clear attenuating effect in the sensitized specimens. This effect suggests a relation between carbide precipitation in the material and the attenuation coefficient of the ultrasonic wave. The attenuation increase is mainly attributed to the continuous distribution and possible coalescence of the carbide along the grain boundaries. Power spectra exhibit an increase of the amplitude at specific frequencies in specimens with the longest sensitization times. Ultrasonic velocity measurements did not provide significant information in order to predict any sensitization grade of the evaluated materials. The combined assessment by spectral analysis and attenuation measurements is discussed.
37 citations
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TL;DR: In this paper, the influence of hydrological seasonality on bacterial production and abundance in two floodplain lakes of the Autana River, a blackwater river in the Middle Orinoco basin, Venezuela, was assessed.
Abstract: Seasonal fluctuation in river stage strongly affects the ecological functioning of tropical floodplain lakes. This study was conducted to assess the influence of hydrological seasonality on bacterial production and abundance in two floodplain lakes of the Autana River, a blackwater river in the Middle Orinoco basin, Venezuela. Water samples for nutrient chemistry, chlorophyll a, and microbiological determinations were collected in two floodplain lakes and in the mainstem of the river during 1997–98. DOC and chlorophyll a concentrations were similar between mainstem and lake sites during high water when river and lakes were well connected but became different during the period of low water when the interaction was minimal. Higher values of bacterial production were observed in the floodplain lakes (0.62–1.03 μg C l−1 h−1) compared to the mainstem sites (0.17–0.19 μg C l−1 h−1) during the period of low water, while during the period of high water river and lake sites showed similar levels (0.04 μg C l−1 h−1). Bacterial numbers followed bacterial production in the floodplain lakes, reaching higher numbers during the period of low water (1.41–2.40 × 106 cells ml−1). Availability of substrate and inorganic nutrients, pH, and inputs and losses of bacterial cells could be determining the observed seasonal patterns in bacterial production and abundance. The Autana lakes exhibited a strong seasonal pattern in the chemical and biological conditions, showing higher productivity during the lentic phase that lasted between 5 and 6 months.
37 citations
Authors
Showing all 5925 results
Name | H-index | Papers | Citations |
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Franco Nori | 114 | 1117 | 63808 |
Ignacio Rodriguez-Iturbe | 96 | 334 | 32283 |
Ian W. Hamley | 78 | 469 | 25800 |
Francisco Zaera | 73 | 432 | 19907 |
Thomas G. Habetler | 73 | 395 | 20725 |
Douglas L. Jones | 70 | 512 | 21596 |
I. Taboada | 66 | 346 | 13528 |
Enrique Herrero | 64 | 242 | 11653 |
Rudi Studer | 60 | 268 | 19876 |
Alejandro J. Müller | 58 | 420 | 12410 |
David Padua | 58 | 243 | 11155 |
Rudolf Jaffé | 58 | 182 | 10268 |
Luis Balicas | 57 | 328 | 14114 |
Volker Abetz | 55 | 386 | 11583 |
Ananias A. Escalante | 51 | 160 | 8866 |