According to whether the cable has a shielding layer, there are two common types of twisted pair cables—shielded twisted pair (STP) cable and unshielded twisted pair (UTP) cable. STP cable is available for Token Ring networks, while the UTP cable is more suitable for Ethernet networks. The most common UTP cable types applied in Ethernet network are cat5e, cat6a, and cat7 cables, etc. The following image shows the different structures of UTP and STP cables.
aluminum processing, preparation of the ore for use in various products.
Aluminum, or aluminium (Al), is a silvery white metal with a melting point of 660 °C (1,220 °F) and a density of 2.7 grams per cubic cm. The most abundant metallic element, it constitutes 8.1 percent of Earth’s crust. In nature it occurs chemically combined with oxygen and other elements. In the pure state it is soft and ductile, but it can be alloyed with many other elements to increase strength and provide a number of useful properties. Alloys of aluminum are light, strong, and formable by almost all known metalworking processes. They can be cast, joined by many techniques, and machined easily, and they accept a wide variety of finishes.
In addition to its low density, many of the applications of aluminum and its alloys are based on its high electrical and thermal conductivity, high reflectivity, and resistance to corrosion. It owes its corrosion resistance to a continuous film of aluminum oxide that grows rapidly on a nascent aluminum surface exposed to air.