Well-posedness for a higher-order Benjamin-Ono equation

In this paper we prove that the initial value problem associated to the following higher-order Benjamin-Ono equation

     

New application of decaniobate salt as basic solid in the synthesis of 4H-pyrans by microwave assisted multicomponent reactions

Research on Chemical Intermediates - This study focuses on the search of new applications of polyoxometalates known as decaniobate ions [Nb10O28]6?. The decaniobates can be used as basic...     

Correction to: Thermal,spectroscopic and antimicrobial activity characterization of some norfloxacin complexes

Journal of Thermal Analysis and Calorimetry - In the original publication, the fifth author’s given name was misspelled as “Gabriel”. The corrected name is given in this erratum....     

MWCNT-Organoimido Polyoxomolybdate Hybrid Material: Analytical Applications for Amperometric Sensing of Hydrogen Peroxide

We report a hybrid material obtained by dispersing the polyoxometalate n-[Bu₄-N]₂[Mo₆O₁₈NC₁₃H₉] functionalized with 2-aminofluorene (POMAF) and multi-walled carbon nanotubes (MWCNTs) in 1,3-dioxolane (MWCNT- POMAF). We demonstrate the peroxidase-like activity of the hybrid material and its application for the amperometric quantification of hydrogen peroxide at −0.450 V previous drop-coating at glassy carbon electrodes, with a linear range between 1.0 μM and 6.0 μM and a detection limit of 330 nM. The reproducibility was 2.2 % using one MWCNTs-POMAF dispersion, and 3.9 % using 4 different dispersions. The sensor was successfully used for the quantification of hydrogen peroxide in enriched milk samples.     

Combination of organic acid and heat–moisture treatment: impact on the thermal,structural, pasting properties and digestibility of maize starch

Journal of Thermal Analysis and Calorimetry - Maize is the most important source of starch used for industrial applications. Its starch properties can be improved by either single or double...     

Remarks on gauge invariance and first-class constraints

Gauge symmetries lead to first-class constraints. This assertion is, of course, true only for non-trivial gauge symmetries, i.e., gauge symmetries that act non-trivially on-shell on the dynamical variables. We illustrate this well-appreciated fact for time reparametrization invariance in the context of modifications of gravity-suggested in a recent proposal by Hořava-in which the Hamiltonian constraint is deformed by arbitrary spatial diffeomorphism invariant terms, where some subtleties are found to arise.     

Iridium complexes with a new type of N^N′-donor anionic ligand catalyze the N-benzylation of amines via borrowing hydrogen

The development of efficient and eco-friendly methods for the synthesis of elaborate amines is highly desired as they are valuable chemicals. The catalytic alkylation of amines using alcohols as alkylating agents, through the so-called borrowing hydrogen process, satisfies several of the principles of green chemistry. In this paper, four neutral half-sandwich complexes of Ru(II), Rh(III), and Ir(III) have been synthesized and tested as catalysts in the N-benzylation of amines with benzyl alcohol. The new derivatives contain a N^N′ anionic ligand derived from 5-(pyridin-2-ylmethylene)hydantoin (Hpyhy) that has never been tested in metal complexes with catalytic applications. In particular, the Ir derivatives, [(Cp*)IrX(pyhy)] (X = Cl or H), exhibit high activity along with good selectivity in the process. Indeed, the scope of the optimized protocol has been proved in the benzylation of several primary and secondary amines. The selectivity towards monoalkylated or dialkylated amines has been tuned by adjusting the amine:alcohol ratio and the reaction time. Experimental results support a mechanism consisting of three consecutive steps, two of which are Ir catalyzed, and a favorable condensation step without the assistance of the catalyst. Moreover, an unproductive competitive pathway can operate when the reaction is performed in open-air vessels, due to the irreversible release of H₂. This route is hampered when the reaction is carried out in close vessels, likely because the release of H₂ is reversed through metal-based heterolytic cleavage. From our viewpoint, these results show the potential of the new catalysts in a very attractive and promising methodology for the synthesis of amines.