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The Cold War period was widely understood as one of bipolarity with the USA and the USSR as the world's two superpowers, whereas the end of the Cold War led to unipolarity with the US as the world's sole superpower in the 1990s and 2000s. Scholars have debated how to characterize the current international system. [2] [3] [4]
The term bipolarization was used to describe the division of the world during the Cold War (1947–1991) between the communist Eastern Bloc, centred on the USSR, and the capitalist Western Bloc. It also defines the state of international relations during this period, dominated by the confrontation between two superpowers , the United States ...
A block diagram of a bipolar HVDC transmission system, between two stations designated A and B. AC – represents an alternating current network CON – represents a converter valve, either rectifier or inverter, TR represents a power transformer, DCTL is the direct-current transmission line conductor, DCL is a direct-current filter inductor ...
Hundreds of bipolar junction transistors can be made in one circuit at a very low cost. Bipolar transistor integrated circuits were the main active devices of a generation of mainframe and minicomputers, but most computer systems now use Complementary metal–oxide–semiconductor integrated circuits relying on the field-effect transistor (FET).
High-voltage direct current (HVDC) transmission lines are either monopolar or bipolar systems. With bipolar systems, a conductor arrangement with one conductor on each side of the tower is used. On some schemes, the ground conductor is used as electrode line or ground return. In this case, it had to be installed with insulators equipped with ...
The rate of decrease and the current strength are within the normal range of variation, as shown by the record of past magnetic fields recorded in rocks. The nature of Earth's magnetic field is one of heteroscedastic (seemingly random) fluctuation. An instantaneous measurement of it, or several measurements of it across the span of decades or ...
2.7V, Ultracapacitor short circuit current [9] 10 4: 25 kA Lorentz force can crusher pinch [10] 30 kA Typical lightning strike 10 5: 100 kA Low range of Birkeland current that creates Earth's aurorae 140 kA "Sq" current of one daytime vortex within the ionospheric dynamo region: 180 kA Typical current used in electric arc furnace for ...
Birkeland currents are also one of a class of plasma phenomena called a z-pinch, so named because the azimuthal magnetic fields produced by the current pinches the current into a filamentary cable. This can also twist, producing a helical pinch that spirals like a twisted or braided rope, and this most closely corresponds to a Birkeland current.