Metal matrix nano composite coatings possess enhanced properties such as corrosion and wear resistance. This paper aims to study the corrosion behavior of pure Co and Co-BN nano composite coatings deposited with different particles concentration (5-20 g L-1) on copper substrates using electroplating technique. Morphology and elemental compositions of the coatings were investigated by means of s...

New special types of stationary conservative impedance and scattering systems, the so-called non-canonical systems, involving triplets of Hilbert spaces and projection operators, are considered. It is established that every matrix-valued Herglotz-Nevanlinna function of the form

Starting from the general modal solutions for a homogeneous layer of arbitrary material and crystalline symmetry, a matrix formalism is developed to establish the semianalytical expressions of the surface impedance matrices (SIM) for a single piezoelectric layer. By applying the electrical boundary conditions, the layer impedance matrix is reduced to a unified elastic form whether the material ...

The paper proposes a simple approximated method for calculation of voltage sags in an electrical network. Following the general method for symmetrical (three-phase) fault calculations based on the use of the bus impedance matrix of the network, the paper illustrates the construction of a square matrix that, under acceptable assumptions, directly provides voltage drops (sags) at each node of the...

This paper proposes a new impedance control algorithm based on a variable stiffness-matrix, for parallel-link manipulators without the measurement of the tip position. It assumes that only the link lengths and velocities as well as the contact force at the tip are measured, and that the motion range is small around an operating point so that the nonlinear dynamics can be linearized. One of the ...

There has been much recent research on preconditioning discretisations of the Helmholtz operator ∆+ k (subject to suitable boundary conditions) with the inverse of a discrete version of the so-called “shifted Laplacian” ∆+ (k + iε) for some ε > 0. (In practice this inverse is replaced with a cheaper approximation in order to obtain a practically viable preconditioner.) Despite many numerical in...

Abstract A robust internal force-based impedance control scheme for coordinating manipulators is introduced. Internal forcebased impedance control enforces a relationship between the velocity of each manipulator and the internal force on the manipulated objects and requires no knowledge of the object dynamic model. Each manipulator's nonlinear dynamics is compensated by a robust auxiliary contr...

In wave chaotic scattering, statistical fluctuations of the scattering matrix S and the impedance matrix Z depend both on universal properties and on nonuniversal details of how the scatterer is coupled to external channels. This paper considers the impedance and scattering variance ratios, Xi(z) and Xi(s), where Xi(z) = Var[Z(ij)]/{Var[Z(ii)]Var[Z(jj)]}1/2, Xi(s) = Var[S(ij)]/{Var[S(ii)]Var[S(...

In many situations, the statistical properties of wave systems with chaotic classical limits are well described by random matrix theory. However, applications of random matrix theory to scattering problems require introduction of system-specific information into the statistical model, such as the introduction of the average scattering matrix in the Poisson kernel. Here, it is shown that the ave...