Influence of Ni on urease activity produced by biofilms of 1388.

New TiO-based hybrid materials composed of an organic polymer, cellulose acetate butyrate and copolymer of acrylonitrile acrylamide (AN + AA) were prepared. The effectiveness of immobilization of microbial strain 1388 on the newly synthesized hybrid membranes was investigated by biochemical methods. The obtained results revealed that the matrix more suitable for biofilm formation was composed of organic polymers without a metal component in the membrane composition.

Ultrasonic self-calibrated method applied to monitoring of sol-gel transition.

In many industrial processes where online control is necessary such as in the food industry, the real time monitoring of visco-elastic properties is essential to ensure the quantity of production. Acoustic methods have shown that reliable properties could be obtained from measurements of velocity and attenuation. This paper proposes a simple, real time ultrasound method for monitoring linear medium properties (phase velocity and attenuation) that vary in time.

One-shot synthesis of a poly(N-isopropylacrylamide)/silica hybrid gel.

Class I hybrid poly(N-isopropylacrylamide)/silica hydrogels, PNIPAM/SiO2, were prepared by a new one shot synthesis. In this approach, the free-radical polymerization of vinyl groups of N-isopropylacrylamide (NIPAM) and the hydrolysis-condensation of alkoxy groups of tetramethoxysilane (TMOS) are performed concomitantly using sodium persulfate and 3-(dimethylamino)-propionitrile, a well-known couple to initiate the organic polymerization. The cross-linker is N,N-methylenebisacrylamide.

Lamb mode reflections at the end of a plate loaded by a viscoelastic material.

This paper deals with a study of the conversion of a Lamb wave at the loaded edge of a plate. An experimental study is performed to know the interaction of surface waves with a viscoelastic material. A Lamb wave is generated by a wedge.

Kinetic study of silica gels by a new rheological ultrasonic investigation.

The last decades have seen the development of sol-gel (SG) process currently used to develop new materials in a wide range of scientific applications. The SG process leads to an oxide macromolecular network through a sol (liquid phase) to gel transition. To optimize this process, the control of the kinetic of the chemical reaction is required.