We give a short proof of a formula of Poincaré-Bertrand in the setting of time-harmonic solutions of the relativistic Dirac equation on a piecewise Liapunov surface, as well as for some versions of quaternionic analysis.

We present an equivariant Liapunov stability criterion for dynamical systems with symmetry. This result yields a simple proof of the energy–momentum–Casimir stability analysis of relative equilibria of equivariant Hamiltonian systems.

In this paper, we consider a contact problem between viscoelastic Bresse beam and deformable obstacle. The well-known normal compliance condition is used to model the contact. existence of unique solution continuous proved using Faedo-Galerkin method. An exponential decay property also obtained defining an adequate Liapunov function. Then, finite element method implicit Euler scheme, approximat...

Study of smut fungi on Liliaceae resulted to propose a new genus and three new combinations: Vankya Ershad, type V. ornithogali (Schmidt et Kunze) Ershad, based on Uredo ornithogali Schmidt et Kunze, V. heufleri (Fuckel) Ershad, based on Ustilago heufleri Fuckel, and V. vaillantii (L.-R. et C. Tulasne) Ershad, based on Ustilago vaillantii L.-R. et C. Tulasne.