Exponential mean square stability of partially linear stochastic systems

The purpose of this paper is to state sufficient conditions for the existence of linear feedback laws which render the equilibrium solution of a composite partially linear stochastic system (the linear part of which is deterministic) exponentially stable in mean square.     

Gluco-indole alkaloids from the bark of Nauclea diderrichii. 1H and 13C NMR assignments of 3alpha-5alpha-tetrahydrodeoxycordifoline lactam and cadambine acid

Detailed (1)H and (13)C NMR assignments of 3alpha-5alpha-tetrahydrodeoxycordifoline lactam and cadambine acid, isolated from the bark of the Nauclea diderrichii (de Wild.) Merr. (Rubiaceae) were achieved by 1D and 2D techniques such as DEPT, HMBC, HMQC, COSY and NOESY.     

Reactions des complexes chlorure cuivreux - PhnP(OPh)3-n (n=0,1,2) avec des composes a halogene positif : les cyano-3 bromo-3 pyrrolidinediones-2,5.

Copper (I) complexes of phosphorus ligands react with 3-cyano 3-bromo pyrrolidine 2,5-diones give phosphoranes and complexes of copper (I)-halogens.     

Unicité de la solution de l'équation monodimensionnelle ou à symétrie sphérique d'un gaz visqueux et calorifère

In questo articolo dimostriamo l'unicità della soluzione (globale in tempo) dell'equazione monodimensionale o a simmetria sferica di un gas viscoso e termoconduttore con la superficie libera. In questo risultato il limite inferiore della densità ρ può essere uguale a 0. Assieme al teorema di esistenza dimostrato nei lavori precedenti, costituisce il teorema di esistenza e di unicità (globale in tempo) per questa equazione.     

The Fundamental Blossoming Inequality in Chebyshev Spaces—I: Applications to Schur Functions

A classical theorem by Chebyshev says how to obtain the minimum and maximum values of a symmetric multiaffine function of n variables with a prescribed sum. We show that, given two functions in an Extended Chebyshev space good for design, a similar result can be stated for the minimum and maximum values of the blossom of the first function with a prescribed value for the blossom of the second one. We give a simple geometric condition on the control polygon of the planar parametric curve defined by the pair of functions ensuring the uniqueness of the solution to the corresponding optimization problem. This provides us with a fundamental blossoming inequality associated with each Extended Chebyshev space good for design. This inequality proves to be a very powerful tool to derive many classical or new interesting inequalities. For instance, applied to Müntz spaces and to rational Müntz spaces, it provides us with new inequalities involving Schur functions which generalize the classical MacLaurin’s and Newton’s inequalities. This work definitely demonstrates that, via blossoms, CAGD techniques can have important implications in other mathematical domains, e.g., combinatorics.     

On Weak Dual Rickart Modules and Dual Baer Modules

We introduce and study the notion of wd-Rickart modules (i.e. modules M such that for every nonzero endomorphism ? of M, the image of ? contains a nonzero direct summand of M). We show that the class of rings R for which every right R-module is wd-Rickart is exactly that of right semi-artinian right V-rings. We prove that a module M is dual Baer if and only if M is wd-Rickart and M has the strong summand sum property. Several structure results for some classes of wd-Rickart modules and dual Baer modules are provided. Some relevant counterexamples are indicated.     

Phytochemical compounds and anti-corrosion activity of Veronica rosea

The aim of this work is the phytochemical study of the butanolic extract of the aerial parts of Veronica rosea. Four compounds 1–4 have been isolated using different chromatographic methods. The structures of these compounds were determined by NMR spectral analysis and mass spectroscopy. The adsorption and anticorrosion effects of this extract were investigated towards the corrosion of copper in 1 M HNO₃ aqueous by the weight loss technique and potentiodynamic polarization. The results showed that the butanolic extract is a good inhibitor and the inhibition efficiency increases with increasing of concentration of the inhibitor. The adsorption of this extract on the copper specimen surface was spontaneous and obeyed the Langmuir’s adsorption isotherm. Large value of adsorption equilibrium Constant (K _ads = 35 L g^?1) was obtained. The polarization experiments confirmed the data obtained by gravimetric weight-loss. Tafel plot of polarization curves indicates that the extract acts as a mixed type inhibitor.     

Thermal radiation and surface roughness effects on the thermo-magneto-hydrodynamic stability of alumina–copper oxide hybrid nanofluids utilizing the generalized Buongiorno’s nanofluid model

Journal of Thermal Analysis and Calorimetry - Sequel to the fact that hybrid nanofluidic systems (e.g. scalable micro-/nanofluidic device) exhibit greater thermal resistance with increasing...