Dieuropium(III) silicodimonophosphatediphosphate

A new europium(III) silicophosphate, whose formula may be considered to be Eu2Si(PO4)2(P2O7), has been found to consist of phosphosilicate chains with Si-O-P-O-P-O-Si backbones extending in the a direction. The P2O7 group and the Si atom both lie on crystallographic twofold axes. Tetrahedral silicon is further bound to two monophosphate groups. This is a silicophosphate of previously unseen type.Peer reviewedChemistr

Etude du systeme GaPO_4-AlPO_4. Cristallogenese et caracterisation des phases Al_1_-_xGa_xPO_4 et GaPO_4

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 79027 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Electrochemical sensor based on low silica X zeolite modified carbon paste for carbaryl determination

A new and simple approach for carbaryl determination in natural sample was proposed using Low Silica X (LSX) zeolite modified carbon paste electrode. LSX zeolite with a porous structure was incorporated into carbon paste electrode in the appropriate portion. The prepared electrode was then characterized using scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Various experimental parameters as the zeolite amounts, pH, accumulation time, and differential pulse voltammetric parameters were optimized. Under optimal conditions, a linear response was obtained in the range of 1–100 µM of carbaryl using differential pulse voltammetry with detection limit of 0.3 µM (S/N = 3). The sensors showed good selectivity, stability, and reproducibility and has been successfully applied for detection of carbaryl in tomato samples with good recoveries

Characteristics and ceramic properties of clayey materials from Amezmiz region (Western High Atlas, Morocco)

Five clayey materials from two quarries located in the Amezmiz region (Morocco) were sampled and investigated for their physical, chemical, mineralogical and thermal characteristics to evaluate their potential suitability as raw materials in various ceramic applications. Physical properties were identified by particle size distribution, consistency limits and total organic content. Chemical, mineralogical, and thermal properties were investigated by XRF, XRD, and TG/DTA techniques, respectively. A common raw material in pottery manufacturing of Morocco was used as reference sample (REF). Results show that the main oxides in the samples were SiO2, Al2O3, and Fe2O3, whereas the other oxides were present only in small quantities. Quartz, illite and vermiculite were present as dominant mineral phases with minor kaolinite, calcite and smectite. The results showed that three of the studied clayey materials have adequate characteristics for the production of structural ceramics. However, for the two other clays it is necessary to add more plastic clays to enhance the workability

Experimental Design-Based Response Surface Methodology Optimization for Synthesis of β-Mercapto Carbonyl Derivatives as Antimycobacterial Drugs Catalyzed by Calcium Pyrophosphate

A simple protocol for the efficient preparation of β-mercapto carbonyl derivatives as antimycobacterial drugs has been achieved via Thia-Michael reaction between chalcones derivatives and thiols in the presence of calcium pyrophosphate as a heterogeneous catalyst under mild reaction conditions. The central composite design was used to design an experimental program to provide data to model the effects of various factors on reaction yield (Y). The variables chosen were catalyst weight X1, reaction time X2, and solvent volume X3. The mathematical relationship of reaction yield on the three significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with experimental values. The optimum reaction conditions for reaction model (chalcone and thiophenol) obtained by response surface were applied to other substrates. This procedure provides several advantages such as high yield, clean product formation, and short reaction time