Apparent Parameters of Enzymatic Plate-Gap Electrode

It was suggested that reaction-diffusion conditions in pores of bulk enzymatic electrode resemble particular conditions in thin enzyme filled gap between parallel conducting plates. The plate-gap model of porous enzymatic electrode is based on the diffusion equations containing a nonlinear term related to the Michaelis-Menten kinetics of the enzymatic reaction inside the gap. Steady state current was calculated for the wide range of given values of substrate diffusion coefficient, depth of the gap and substrate concentrations. Simple approximate relationships between “apparent” parameters of amperometric biosensor (maximal currents and apparent Michaelis constants) and given values of diffusion characterising parameters were derived. Association of these dependences with previously reported relationships led to derive approximate formulae that bind apparent parameters with the complete set of given parameters of the plate-gap enzymatic electrode. The limit case of slow diffusion into deep gap was also characterised. In this specific case, the highest numerical values of the apparent parameters were obtained. However, this gain is achievable at the expense of biosensor response time

MICROWAVE INVESTIGATION OF MAGNETIC PERMEABILITY OF MANGANITES

The real µ /µ0 and imaginary µ /µ0 parts of the relative magnetic permeability of La0.7Ca0.3MnO3 thin films and the influence of the electric permittivity and resistivity on the measurement results were investigated under microwave radiation of 10 GHz frequency employing the waveguide measurement and splitter methods

Response of Grained La0.67\text{}_{0.67}Ca0.33\text{}_{0.33}MnO3\text{}_{3} Films to Microwave Radiation and the Method for Measuring Electrical Resistance of Grains

It was found that the response of grained La$\text{}_{0.67}$Ca$\text{}_{0.33}$MnO$\text{}_{3}$ films to microwave radiation is of thermal nature. A nonresonant method for measuring of the electric resistance of grains was developed. It allows one to avoid the influence of the magnetic field of the wave on the measurement results. The measurements of the temperature dependences of the grain electric resistance indicate that in the vicinity of the maximum-resistance temperature T$\text{}_{m}$, the intrinsic electric resistance of the grains is more than by two orders of magnitude lower than the film resistance measured by applying the dc current. The obtained experimental results agree well with those given by resonant techniques

Response of Grained La 0.67

It was found that the response of grained La$\text{}_{0.67}$Ca$\text{}_{0.33}$MnO$\text{}_{3}$ films to microwave radiation is of thermal nature. A nonresonant method for measuring of the electric resistance of grains was developed. It allows one to avoid the influence of the magnetic field of the wave on the measurement results. The measurements of the temperature dependences of the grain electric resistance indicate that in the vicinity of the maximum-resistance temperature T$\text{}_{m}$, the intrinsic electric resistance of the grains is more than by two orders of magnitude lower than the film resistance measured by applying the dc current. The obtained experimental results agree well with those given by resonant techniques