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  • Author or Editor: M. Valdés x
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Abstract  

The present work shows a methodology for the application of EDXRF with a X-ray tube, in the analysis of elements in the following matrices: microalgae, marine algae, marine sediments and corals. Various methods were applied: one using a relative external standard, a fundamental parameters method, an absolute method based on elemental sensitivity, a method which used X-ray fluorescence excitation measured in the back side of the sample for low contents heavy elements determination and a TRXRF method. The thin layer samples were prepared using a plastic resin. The analyzed samples of marine algae, marine sediments and corals belong to a marine ecosystem from the North of Havana City, the most affected area by natural metereological phenomena and human impact.

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Abstract

In this paper we present different variants of the well-known Hermite–Hadamard inequality, in a generalized context. We consider general fractional integral operators for h-convex and r-convex functions.

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