Showing papers by "Grenoble Institute of Technology published in 1977"

Water in keratin: Study of the depolarization thermal current peak II.

Abstract: The depolarization thermal current method is applied to the study of the polarization phenomena in the keratin-water system. Three depolarization thermal current peaks have been evidenced in hair keratin. This paper deals with the detailed study of peak II. For the first time, the mechanism responsible for this peak is ascribed to molecular reorientation. The effect of water upon the characteristics of peak II is also described, and an activation energy of 8.4 kcal/mol is computed. These results, in connection with other studies, lead us to interpret peak II as due to the reorientation in the bound or intermediate water molecules. The effect of copper confirms that the carboxyl groups are hydration sites.

A new numerical solution of Ẋ = A_{1}X + XA_{2} + D, X(0) = C

Abstract: Another numerical solution of the general matrix differential equation \circ{X}=A_{1}X+XA_{2}+D, X(0)=C for X is considered without any stability condition for A 1 and A 2 . Like Davison's method, the proposed algorithm requires only some n 2 words of memory and n_{3 multiplications where n=\max(n_{1},n_{2}) and A \in R^{n_{1} \times n_{1}},A_{2} \in R^{n_{2} \times n_{2}} . This new approach is well suited to solve large and possibly unstable systems. We take the opportunity to run the differential equation for various D. A very efficient technique follows to design the so-called receding horizon control problem.