According to the present invention there is provided a body at least partially coated with one or more refractory layers of which at least one layer essentially consist of \u03b1-Al2O3. These messages include information that allows the Web routers to dynamically update mappings of client addresses or address ranges to information object repository addresses based on client-to-server distance and server load. A coiled spring 7 for biasing the first and second engagement members in the direction away from each other is disposed between the first and second engagement members 4 and 4\u2032. The method results in a structure which prevents an open circuit. Each of the two NPC diodes corresponds to one of the at least two switches. In one embodiment, the group IVB transition metal component is titanium, titanium hydride, or mixtures thereof.