abstract: in this paper a control scheme for grid-connected operation mode and the island state of distributed generation is presented. in normal conditions, every inverter dg system in micro-grids to supply a preset power, normally operate in a constant current control mode. when micro-grids removed from the network, dg inverter of each system must recognize the island and change position to v...

In this paper, we study the stability of an initially straight elastic fibril clamped at one end, while the other end is subjected to a constant normal compressive force and a prescribed shear displacement. We found the buckling load of a sheared fibril to be always less than the Euler buckling load. Furthermore, if the end of the fibril loses adhesion, then the buckling load can be considerabl...

In this work, the plane-on-plane torsional fretting tribological behavior of polytetrafluoroethylene (PTFE) was studied. A model of a rigid, flat-ended punch acting on an elastic half-space was built according to the experimental conditions. The results indicate that the shape of T-θ curves was influenced by both the torsional angle and the normal load. The torsion friction torque and wear rate...

The main idea of this chapter is to try to measure to which extent a surface S is different from a plane, in other words, how “curved” is a surface. The idea of doing this is by assigning to each point P on S a unit normal vector N(P ) (that is, a vector perpendicular to the tangent plane at P ). We are measuring to which extent is the map from S to R given by P 7→ N(P ) (called the Gauss map) ...

The influence of applied normal load and roughness on the tribological behavior between the indenter and sample surface during nanoindentation-based scratching has been experimentally investigated by using different surfaces (fused silica and diamond-like carbon) featuring various degrees of roughness. At a sufficiently low applied normal load, wherein the contact is elastic, the friction coeff...

The fundamental frictional behaviour of carbon fibre tows relevant to composite fabric forming is explored. Tow-on-tool and tow-on-tow contact are considered. For tow-on-tool contact, an experiment is devised to simultaneously observe the true filament contact length and measure the friction force over a range of normal loads. Filament contact length is not constant, as would be given from an i...

To the Editor: Denervation affects greatly cardiac function in HTx recipients. However, it is not the main determinant of their reduced aerobic performance (1, 6). Indeed, the latter depends on complex interactions among cardiac, pulmonary, neurohormonal, vascular, and skeletal muscle function (or “dysfunction”). The relative role of each of these factors may vary depending on donor’s heart cha...