Hanoi vs Cobalt

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Hanoi (UK: ha-, hə-NOY or US: hah-NOY; Vietnamese: Hà Nội [hàː nôjˀ] (listen)) is the capital city of Vietnam. It covers an area of 3,358.6 km2 (1,296.8 sq mi). It is the second largest city in Vietnam, with over eight million residents within the city proper and an estimated population of 20 million within the metropolitan area. Located in part of the Red River Delta, Hanoi is the commercial, cultural, and educational centre of Northern Vietnam. Having an estimated nominal GDP of US$32.8 billion as of 2018, it is the second most productive economic area of Vietnam, after Ho Chi Minh City. The city is a settlement along the banks of the Red River. In 257 B.C, under the rule of king An Dương Vương, the citadel of Cổ Loa, nowaday Đông Anh district of Hanoi, was constructed and served as the capital of Âu Lạc. After the fall of Âu Lạc, the city was renamed to Tống Bình and ultimately Đại La. In 1010, emperor Lý Thái Tổ moved the capital to Đại La, renaming it Thăng Long (literally "Ascending Dragon"). Thăng Long would remain the political and cultural centre of the state of Đại Việt until 1802, when the Nguyễn dynasty, the last imperial dynasty of Vietnam, moved the capital to Huế.

The city renamed to Hanoi in 1831, and was the capital of French Indochina from 1883 to 1945. On 6 January 1946, the National Assembly of the Democratic Republic of Vietnam designated Hanoi as the capital of the newly-independent country, which would last during the First Indochina War (1946–1954) and the Vietnam War (1955–1975). Hanoi has been the capital of the Socialist Republic of Vietnam since 1976. Historically it had Chinese, French and Russian influences. It hosts various venerable educational institutions and cultural venues of significance, including the Vietnam National University, the Mỹ Đình National Stadium, and the Vietnam National Museum of Fine Arts. On 16 July 1999, the UNESCO presented the title "City for Peace" to Hanoi. Hanoi joined UNESCO's Network of Creative Cities as a Design City on 31 October 2019 on the occasion of World Cities' Day.

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