Microbiology proficiency testing schemes in wine

Accreditation and Quality Assurance - The number of laboratories performing microbiological analyses of wines has gradually increased in recent years over the world. However, the lack of regular...     

Spectroscopic and thermal investigations of poly(vinylidene fluoride) films composites with LaNi3Co2

Poly(vinylidene fluoride) (PVDF) and LaNi₃Co₂ were composites in various combinations by using melting technique. Morphological and physical properties of both the surface and interface of poly(vinylidene fluoride)/ LaNi₃Co₂ composite films have been investigated. FTIR and XRD diffraction analysis evidenced the increase of α, β and γ‐ PVDF crystalline phases. The bands at 888 and 1414 cm^‐1 were assigned to γ‐phase of PVDF. Maximum value of the relative amount of β‐phase was observed at 35 and 60% FL. This result was confirmed by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. Maximum value of degree of crystallinity was observed at 15% Filling level (FL). Morphology of SEM consists of two different size rings and spherulites. DSC was used to identify the melting temperature, the order of reaction and the activation energy of melting. A sharp endothermic peak at T_m ≈ 444 K due to melting and T₂ ≈ 360 K due to α‐relaxation/transition. Maximum values of magnetoresistance (MR) observed from range (243 to 238K) are due to reorientation of dipoles in a process associated with the glass transition temperature of PVDF. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Application of lower-bound direct method to large-scale problems

In this paper, a lower-bound direct method is presented for the large-scale problems. This method is based on the statical shakedown analysis and nonlinear mathematical programming. Here, the interior point method combined with the method of difference of convex functions (IPDCA) is used to solve large-scale problems. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Calculated pre-exponential factors and energetics for adatom hopping on terraces and steps of Cu(1 0 0) and Cu(1 1 0)

We have calculated the vibrational dynamics and thermodynamics for Cu adatom hopping on terraces and near step edges on Cu(1 0 0) and Cu(1 1 0), using the embedded atom method for the interatomic potential. The local vibrational densities of states were calculated using real space Green’s function formalism and the thermodynamical functions were evaluated in the harmonic approximation. The calculated diffusion energy barriers for six specific local environments on Cu(1 0 0) agree well with experimental and previous theoretical results. Contribution of vibrational entropy to the change in the free energy of the system as the adatom moves from the equilibrium configuration (hollow site) to the saddle point, is found to be as much as 55 meV (144 meV) at 300 K (600 K). The prefactors for all 13 cases are found to be of the order of 10⁻³ cm²/s, almost independent of temperature, and the respective activation energy barriers.     

The harmonic measure and a Reuter-type result for a process with Bessel components

Let $B_{p\text{,}q}$ be the $R^2$-valued process $(B_p\text{,}{B}_q)$ with independent Bessel components $B_p$ and $B_q$ with indices p and q strictly positive. In this paper we compute explicitly the law of the hitting time and place of a circle, centered at the origin, when $B_{p\text{,}q}$ starts from the center and deduce a Reuter-type independence result. We use mainly analytical tools from PDE theory. To cite this article: A. Ziadi, A. Bencherif-Madani, C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

Comparison of different synthesis methods for nasicon ceramics

Various methods for the synthesis of Na₂Zr₂P₂SiO₁₂ ceramics have been investigated. The methods differ by the order of mixing and the use of acetylacetone to decrease the reactivity of zirconium. The homogeneity of the powders prior to calcination has been checked by ³¹P NMR. Their reactivity towards crystallization is not drastically different. The sintering behaviour is much better in powders in which the zirconium reactivity has been decreased. The effect of the processing on the resulting ionic conductivity of the ceramics has been studied.     

Biopolymer-layered polysilicate micro/nanocomposite based on chitosan intercalated in magadiite

On the basis of their high adsorption and cation exchange capacity, swelling potential and low toxicity, layered sodium silicate magadiite (Na–magadiite) is an attractive solid for intercalation of polymers. This study envisages the intercalation of cationic biopolymer chitosan (Chit) in Na–magadiite to prepare a Chit/magadiite micro/nanocomposite. Characterisation of starting-magadiite, pure chitosan and Chit/magadiite were investigated using powder X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy and thermal analysis. XRD confirmed that the chitosan had been intercalated into the interlayer space of magadiite by increasing the basal spacing, d₀₀₁ from 15.6 Å to 21.45 Å. The presence of characteristic bands of biopolymer and layered silicate in Chit/magadiite were confirmed by FTIR analysis. The thermal stability of micro/nanocomposite was evaluated by thermogravimetry analysis. The results suggested the formation of electrostatic interactions by protonated amine groups with the negatively charged magadiite surface as well as intercalation in the form of a predominant monolayer arrangement of chitosan chains in layered silicate magadiite.     

The \bar{\partial }-Equation on an Annulus Between Two Strictly q-Convex Domains with Smooth Boundaries

In this paper, we study the global boundary regularity of the \(\bar{\partial }\) - equation on an annulus domain \(\Omega \) between two strictly \(q\) -convex domains with smooth boundaries in \(\mathbb{C }^n\) for some bidegree. To this finish, we first show that the \(\bar{\partial }\) -operator has closed range on \(L^{2}_{r, s}(\Omega )\) and the \(\bar{\partial }\) -Neumann operator exists and is compact on \(L^{2}_{r,s}(\Omega )\) for all \(r\ge 0\) , \(q\le s\le n-q- 1\) . We also prove that the \(\bar{\partial }\) -Neumann operator and the Bergman projection operator are continuous on the Sobolev space \(W^{k}_{r,s}(\Omega )\) , \(k\ge 0\) , \(r\ge 0\) , and \(q\le s\le n-q-1\) . Consequently, the \(L^{2}\) -existence theorem for the \(\bar{\partial }\) -equation on such domain is established. As an application, we obtain a global solution for the \(\bar{\partial }\) equation with Hölder and \(L^p\) -estimates on strictly \(q\) -concave domain with smooth \(\mathcal C ^2\) boundary in \(\mathbb{C }^n\) , by using the local solutions and applying the pushing out method of Kerzman (Commun Pure Appl Math 24:301–380, 1971).