Effects of light intensity and dilution rate on the semicontinuous cultivation of Arthrospira (Spirulina) platensis. A kinetic Monod-type approach

Semicontinuous cultures were carried out at different dilution rates (D) and light intensities (I) to determine the maximum productivity of Arthrospira platensis cultivated in helicoidal photobioreactor up to the achievement of pseudo-steady-state conditions. At I = 108 mu mol photons m(-2) s(-1), the semicontinuous regime ensured the highest values of maximum cell concentration (X(m) = 5772 +/- 113 mg L(-1)) and productivity (P(XS) = 1319 +/- 25 mg L(-1) d(-1)) at the lowest (D = 0.1 day(-1)) and the highest (D = 0.3 day(-1)) dilution rates, respectively. A kinetic model derived from that of Monod was proposed to determine the relationship between the product of light intensity to dilution rate (ID) and the cell productivity, which were shown to exert a combined influence on this parameter. This result put into evidence that pseudosteady-state conditions could be modified according to circumstances, conveniently varying one or other of the two independent variables. (C) 2010 Elsevier Ltd. All rights reserved.

Memória esquecida de experiências oceanográficas em Cabo Verde Expedições de Jacques-Yves Cousteau, Théodore Monod e Auguste Piccard

O artigo comenta as experiências oceanográficas realizadas em Cabo Verde por Jacques-Yves Cousteau, Théodore Monod e Auguste Piccard no fim dos anos quarenta do século vinte. A recuperação da memória científica serve como base para uma reflexão sobre o carácter transdisciplinar da oceanografia e o seu interesse no contexto de Cabo Verde. Os autores fazem também uma breve descrição da zona onde decorreram os trabalhos, indicando quer alguns perigos ambientais, quer potencialidades para o turismo ecológico.

Traité des maladies du testicule... par Ch. Monod,... et D. Terrillon,...

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