Epoxy nanocomposites with multiwall carbon nanotubes (MWCNTs) filler up to 0.3%wt were prepared by shear mixing and good dispersion of the MWCNTs in the epoxy was successfully achieved. The electrical behaviour was characterized by measurements of the alternating current (AC) and direct current (DC) conductivities at room temperature. Typical percolation law behaviour was observed with a low pe...

Maxwell’s equations for propagation of electromagnetic waves in dispersive and absorptive (passive) media are represented in the form of the Schrödinger equation i∂Ψ/∂t = HΨ, where H is a linear differential operator (Hamiltonian) acting on a multi-dimensional vector Ψ composed of the electromagnetic fields and auxiliary matter fields describing the medium response. In this representation, the ...

When revisiting the Faber-Krahn inequality for the principal pLaplacian eigenvalue of a bounded open set in Rn with smooth boundary, we simply rename it as the p-Faber-Krahn inequality and interestingly find that this inequality may be improved but also characterized through the Maz’ya’s capacity method, the Euclidean volume and the Sobolev-type inequality. 1. The p-Faber-Krahn Inequality Intro...

supports her claim that it is impossible to "separate the biological from the social and political" in the history of Ecuador's Indians under colonial rule (p. 3.) Although the study focuses on a small area and there is little attempt to relate it to work elsewhere, this is a study that deserves to be read as a model of its kind and offers an inviting basis for comparative discussion within the...

The need to evaluate expressions of the form f(A) or f(A)b, where f is a nonlinear function, A is a large sparse n × n matrix, and b is an n-vector, arises in many applications. This paper describes how the Faber transform applied to the field of values of A can be used to determine improved error bounds for popular polynomial approximation methods based on the Arnoldi process. Applications of ...

We show a Faber-Krahn-type inequality for regular trees with boundary.

Lewis Wolpert is Professor of Biology as Applied to Medicine at University College London. He originally trained as a civil engineer in South Africa, but changed to research in cell and developmental biology in 1955. His main contributions are related to morphogenesis and his concept of positional information. He was for four years Chairman of the Committee for the Public Understanding of Scien...