Determination of Cadmium,Copper, Lead,and Zinc in Pilchard Sardines from the Bay of Boumerdés by Atomic Absorption Spectrometry

Fish are an important human food with increasing consumption in recent decades. Diet is the main route of exposure to heavy metals for human health. For this reason, many studies have been performed on the pollution by heavy metals in different species of fish. Our main objective was to evaluate the pollution by trace metals (Zn, Cu, Pb, and Cd) in sardine muscles collected from the bay of Boumerdés (Algeria). Flame atomic absorption spectroscopy (AAS) was used for the quantification of Cu and Zn. The quantification of Cd and Pb was achieved by graphite furnace (GF) AAS. The analysis revealed the presence of metal trace elements in the muscles of species at concentrations below the thresholds established by national and international regulations.     

Redetermination of the O-O bond length in the dioxygen-adduct of Vaska’s complex

Solid state structural studies were performed with (Ph₃P)₂IrCl(CO)(O₂) and the O-O length redetermined to be 1.47(1) Å in contrast to results reported earlier.     

Rhodium-catalyzed cascade reactions: A methylenation-hydroboration homologative process

A very efficient rhodium-catalyzed cascade process allowing the transformation of aldehydes and ketones into their corresponding one or two-carbon homologated alcohol products through a methylenation-hydroboration sequence is reported. Wilkinson’s complex is used to catalyze both reactions in a one-pot procedure that does not require the isolation of the alkene intermediate.     

Correction to: On Formal Modeling and Validation of Wireless Sensor Network Protocols

Wireless Personal Communications -     

Reductive one-carbon homologation of aldehydes and ketones

[reaction: see text] A rhodium-catalyzed methylenation-hydrogenation cascade process allows the homologation of carbonyl compounds to lead to the corresponding alkanes in high yields.     

On Formal Modeling and Validation of Wireless Sensor Network Protocols

Formal verification is becoming more and more important in the field of wireless networks (WSN). The general purpose formal method called Event-B is the latest incarnation of the B Method: it is a proof based approach with a formal notation and refinement technique for modeling and verifying systems. Refinement enables implementation level features to be proven correct with respect to an abstract specification of the system. This paper proposes an initial attempt to model and verify consistency and correctness of a WSN operation in its different layers. Several formal models are introduced for this type of networks. In the first time, coloured Petri net are used to elaborate network layer models, then each one will be detailed by an Event-B formalism, while proofs are carried out using the RODIN platform which is an integrated development framework for Event-B.

     

Palladium-catalyzed cross-coupling reactions in one-pot multicatalytic processes

Palladium-catalyzed cross-coupling reactions have been investigated in multicatalytic processes to synthesize disubstituted alkenes and alkanes from carbonyl derivatives. The use of copper-catalyzed methylenation reactions is the key starting reaction to produce terminal alkenes which are not isolated, but submitted to further structure elongation. Not only is the isolation of the alkene intermediate unnecessary, but also the copper catalyst is a beneficial cocatalyst in the palladium-catalyzed cross-coupling reactions. The desired products are thus typically obtained in higher yields using this one-pot approach. We have used these processes to synthesize hydroxylated (E)-stilbenoids, which are known chemopreventive and chemotherapeutic agents, odorant-substituted indanes, and non-natural amino acids, such as homophenylalanine.