Modeling of a ring rosen-type piezoelectric transformer by Hamilton's principle.

This paper deals with the analytical modeling of a ring Rosen-type piezoelectric transformer. The developed model is based on a Hamiltonian approach, enabling to obtain main parameters and performance evaluation for the first radial vibratory modes. Methodology is detailed, and final results, both the input admittance and the electric potential distribution on the surface of the secondary part, are compared with numerical and experimental ones for discussion and validation.

Modeling and identification of Rosen-type transformer in nonlinear behavior.

This paper is about the modeling of piezoelectric transformer in nonlinear behavior conditions. In the frame of applications with high output loads, nonlinear behavior be comes non-negligible. First, the origins of nonlinearities and theoretical approaches are preliminarily discussed.

Multimodal electromechanical model of piezoelectric transformers by Hamilton's principle.

This work deals with a general energetic approach to establish an accurate electromechanical model of a piezoelectric transformer (PT). Hamilton's principle is used to obtain the equations of motion for free vibrations. The modal characteristics (mass, stiffness, primary and secondary electromechanical conversion factors) are also deduced.

Optimal design of piezoelectric transformers: a rational approach based on an analytical model and a deterministic global optimization.

This paper deals with a deterministic and rational way to design piezoelectric transformers in radial mode. The proposed approach is based on the study of the inverse problem of design and on its reformulation as a mixed constrained global optimization problem. The methodology relies on the association of the analytical models for describing the corresponding optimization problem and on an exact global optimization software, named IBBA and developed by the second author to solve it.

[Utility of serotyping in the study of Serratia marcescens infections in Strasbourg Hospitals (author's transl)].

A total of 1,499 Serratia marcescens strains were isolated in Strasbourg University Hospital within a period of three years. Serotyping could split this collection into 37 different serotypes. Two serotypes (014:H12 and 013:H17) were responsible for a persistent S.