Stationary solution of the ring-spinning balloon in zero air drag using a RBFN based mesh-free method

A technique for numerical analysis of the dynamics of the ring-spinning balloon based on the Radial Basis Function Networks (RBFNs) is presented in this paper. This method uses a 'universal approximator' based on neural network methodology to solve the differential governing equations which are derived from the conditions of the dynamic equilibrium of the yarn to determine the shape of balloon yarn. The method needs only a coarse finite collocation points without any finite element-type discretisation of the domain and its boundary for numerical solution of the governing differential equations. This paper will report a first assessment of the validity and efficiency of the present mesh-less method in predicting the balloon shape across a wide range of spinning conditions

Optical Algal Biosensor using Alkaline Phosphatase for Determination of Heavy Metals

International audienceA biosensor is constructed to detect heavy metals from inhibition of alkaline phosphatase (AP) present on the external membrane of Chlorella vulgaris microalgae. The microalgal cells are immobilized on removable membranes placed in front of the tip of an optical fiber bundle inside a homemade microcell. C. vulgaris was cultivated in the laboratory and its alkaline phosphatase activity is strongly inhibited in the presence of heavy metals. This property has been used for the determination of those toxic compounds

Biosensor using immobilized Chlorella microalgae for determination of volatile organic compounds.

International audienceA biosensor using Chlorella microalgae immobilized on the membrane of an oxygen electrode has been designed to determine volatile organic compounds (VOC) in the form of aerosols. A homemade controlled atmosphere chamber is constructed for perchloroethylene detection. Monitoring of perchloroethylene is obtained by the measurement of the oxygen production during the algae photosynthetic process

Fluorescent biosensor using whole cells in an inorganic translucent matrix

8 pagesInternational audienceAn optical biosensor based on vegetal cells entrapped in an inorganic translucent matrix and fluorescence detection has been developed. The biosensor uses Chlorella vulgaris immobilized in a translucent support produced from sol-gel technology. The translucence of the structure enables the algal active layer to be placed directly in contact with the optical fibers for fluorescence detection. This configuration has many advantages over the use of an opaque support because no space between the optical fibers and the active layer is required to collect fluorescence. This reagentless biosensor allows determination of diuron as an anti-PSII herbicide and its long term activity is assessed

Sol-gel process for vegetal-cells encapsulation

International audienceA sol-gel process was carried out at room temperature to obtain porous silica matrixes for entrapment of vegetal cells. The process uses sodium silicate as a precursor rather than alkoxides to avoid generation of by-products that is detrimental to Chlorella vulgaris cells. The influence of several factors influencing the gelification was explored to optimize the encapsulation process. The technique produces a transparent matrix and is then very suitable for vegetal cells entrapment since they require light for their photosynthetic activity. Activity of the algal cells was determined by measurement of the intensity of fluorescence emission at 682 nm. This measurement also allowed to evaluate the efficiency of the immobilization technique and assess the long term activity of the encapsulated whole-cells