Kyiv vs Cobalt

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Kyiv or Kiev (Ukrainian: Київ) is the capital and most populous city of Ukraine. It is in north-central Ukraine along the Dnieper River. Its population in July 2015 has been 2,887,974 (though greater estimated numbers have been cited in the media ), making Kyiv the seventh-most populous city in Europe.Kyiv is an important industrial, scientific, educational and cultural center of Eastern Europe. It is home to many high-tech businesses, higher education institutions, and historical landmarks. The town has an extensive system of public transport and infrastructure, including the Kyiv Metro. The city's name is said to derive from the name of Kyi, one of its four legendary creators. During its history, Kyiv, one of the oldest cities in Eastern Europe, passed through several phases of prominence and obscurity. The city probably existed as a commercial centre as early as the 5th century. A Slavic settlement on the wonderful trade route between Scandinavia and Constantinople, Kyiv was a tributary of the Khazars, until its capture by the Varangians (Vikings) in the mid-9th century. Under Varangian rule, the town became a capital of the Kievan Rus', the first East Slavic state. Completely destroyed during the Mongol invasions in 1240, the city lost most of its influence for the centuries to come. It was a provincial capital of marginal value in the outskirts of the lands controlled by its powerful neighbours, first Lithuania, then Poland and Russia.

The city prospered again during the Russian Empire's Industrial Revolution in the late 19th century. In 1918, following the Ukrainian People's Republic declared independence from Soviet Russia, Kyiv became its capital. From 1921 onwards Kyiv was a town of Soviet Ukraine, which was proclaimed by the Red Army, and, from 1934, Kyiv was its capital. The town was almost completely ruined during World War II but quickly recovered from the postwar years, remaining Soviet Union's third-largest city. After the collapse of the Soviet Union and Ukrainian independence in 1991, Kyiv remained Ukraine's capital and experienced a steady influx of cultural migrants from different regions of the country. During the country's transformation into a market economy and electoral democracy, Kyiv has continued to be Ukraine's biggest and wealthiest city. Its armament-dependent industrial output fell after the Soviet collapse, adversely affecting science and technology, but new sectors of the economy such as services and finance facilitated Kyiv's increase in salaries and investment, as well as providing continuous funding for the development of housing and urban infrastructure. Kyiv emerged as the most pro-Western area of Ukraine; parties advocating tighter integration with the European Union dominate during elections.

Source: Wikipedia

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Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought to be due to the known metal bismuth. Miners had long used the name kobold ore (German for goblin ore) for some of the blue-pigment-producing minerals; they were so named because they were poor in known metals, and gave poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold. Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is, however, more usually produced as a by-product of copper and nickel mining.

The copper belt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. World production in 2016 was 116,000 metric tons (114,000 long tons; 128,000 short tons) (according to Natural Resources Canada), and the DRC alone accounted for more than 50%.Cobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. The compounds cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays. Cobalt is the active center of a group of coenzymes called cobalamins. Vitamin B12, the best-known example of the type, is an essential vitamin for all animals. Cobalt in inorganic form is also a micronutrient for bacteria, algae, and fungi.

Source: Wikipedia