Strontium hexabromodicadmate(II) octahydrate

The ternary system SrBr₂–CdBr₂–H₂O was investigated at room temperature. The title phase, SrCd₂Br₆·8H₂O, has been isolated from this system and its structure determined by single‐crystal X‐ray diffraction. The structure consists of infinite double chains of CdBr₆ octahedra and chains of Sr(H₂O)₉ polyhedra packed along the b axis. The interaction between these two isolated chains occurs through O—H⃛O and O—H⃛Br hydrogen bonds. The structure is compared with that of SrCd₂Cl₆·8H₂O.     

Spectrophotometric and Polarographic Studies on 9,10-Anthradione-2-Sodium Sulfonate

The effect of solvent structure on the rates of redox reactions in alcohol+water mixture was discussed by some authors. The rate of photoreduction of 9,10-anthraquinone-2-sulfonate was decreased by addition of H₂SO₄ but was unchanged by increase of ionic strengh with (NH₄)₂SO₄. The magnitude of the decrease in presence of acid was greater with ethanol or isopropanol than with N-ethylacetamide as substrate. The formation of semiquinone and carbonate radical anions was observed⁽⁴⁾ during the direct photoreaction. The electron transfer from the carbonate anion to sulfoanthraquinone in the first excited triplet state was the controlling step of this process. Therefore, anthraquinone β-sodium sulfonate is efficient sensitizers of the photooxidation of organic substrates in aqueous media.     

Conductivity and Structural Investigations in Lacunary Pb6Ca2Li2(PO4)6 Apatite

Prismatic crystals of Pb₆Li₂Ca₂(PO₄)₆ were obtained by solid-state reaction. They were characterized by IR spectroscopy and chemical analyses. The structure as determined by X-ray diffraction study on single crystal revealed that the compound is isostructural to the hexagonal phase Pb₈Na₂(PO₄)₆. Crystal data for Pb₆Li₂Ca₂(PO₄)₆: space group P63/m (No. 176), a=b=9.6790(15) Å, c=7.1130(7), Z=1, R=0.039. In the compound, lithium was found to preferentially occupy the site (I) and the structure is stabilized by interactions between electron lone pairs of lead (II) ions. Electrical conductivity measured in a wide range of temperature is governed by a hopping mechanism of Li ions in tunnels.     

Antimicrobial and antioxidant activities of the methanolic extracts of three Salvia species from Tunisia

This study examines the in vitro antimicrobial and antioxidant activities of the methanolic extracts of three Salvia species from Tunisia: Salvia aegyptiaca L., S. argentea L. and S. verbenaca Ssp. clandestina L. Pugsley. The extracts inhibited the growth of dermatophytes and of bacteria responsible for unpleasant odours to varying degrees; the pathogenic yeasts Candida albicans and Cryptococcus neoformans, the filamentous fungi Aspergillus fumigatus and selected dog otitis bacteria were all resistant to each of the extracts. The extracts were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) test systems, and gave positive results in both tests. The extracts of S. aegyptiaca were the most active in both tests, followed by those of S. verbenaca, then S. argentea. These results confirm the antimicrobial and antioxidant activities of the genus Salvia and underline the potential of these plants either as natural preservatives or in pharmaceutical applications.     

Some new properties of asynchronous algorithms of theta scheme combined with finite elements methods for an evolutionary implicit 2‐sided obstacle problem

In this paper, we give some new properties of the presented asynchronous algorithms of theta scheme combined with finite elements methods (App. Math. Comp., 217 (2011), 6443‐6450) for an evolutionary implicit 2‐sided obstacle problem to prove the existence and uniqueness of the discrete solution. Furthermore, an error estimate on the uniform norm is given.     

Anticipating stochastic differential systems with memory

This article establishes existence and uniqueness of solutions to two classes of stochastic systems with finite memory subject to anticipating initial conditions which are sufficiently smooth in the Malliavin sense. The two classes are semilinear stochastic functional differential equations (sfdes) and fully nonlinear sfdes with a sublinear drift term. For the semilinear case, we use Malliavin calculus techniques, existence of the stochastic semiflow and an infinite-dimensional substitution theorem. For the fully nonlinear case, we employ an anticipating version of the Itô–Ventzell formula due to Ocone and Pardoux [D. Ocone, E. Pardoux, A generalized Itô–Ventzell formula. Application to a class of anticipating stochastic differential equations, Annales de l’Institut Henri Poincaré. Probabilité s et Statistiques 25 (1) (1989) 39–71]. In both cases, the use of Malliavin calculus techniques is necessitated by the infinite dimensionality of the initial condition.