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The Beulé Gate is a fortified gate leading to the Propylaia of the Acropolis of Athens, Greece.It was constructed largely of repurposed material taken from the 4th-century BCE Choragic Monument of Nikias and integrated into the Post-Herulian Wall, a late Roman fortification built around the Acropolis in the years following the city's sack by the Germanic Heruli people in 267 or early 268 CE.
What links here Related changes Upload file Special pages Permanent link Page information Cite this page Get shortened URL Download QR code Statistical subregions as defined by the United Nations Statistics Division This is a list of countries and other inhabited territories of the world by total population, based on estimates published by the United Nations in the 2022 revision of World ...
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At 20 °C (68 °F), the speed of sound in air is about 343 m/s (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn ), or 1 km in 2.91 s or one mile in 4.69 s. It depends strongly on temperature as well as the medium through which a ...
Frequency bands for 5G New Radio (5G NR), which is the air interface or radio access technology of the 5G mobile networks, are separated into two different frequency ranges. First there is Frequency Range 1 (FR1), which includes sub-6 GHz frequency bands, some of which are traditionally used by previous standards, but has been extended to cover potential new spectrum offerings from 410 MHz to ...
Numerical value, notation, and units The speed of light in vacuum is usually denoted by a lowercase c, for "constant" or the Latin celeritas (meaning 'swiftness, celerity'). In 1856, Wilhelm Eduard Weber and Rudolf Kohlrausch had used c for a different constant that was later shown to equal √ 2 times the speed of light in vacuum. . Historically, the symbol V was used as an alternative symbol ...
NASA (historical) Number built. 32. Developed from. Lockheed A-12. The Lockheed SR-71 " Blackbird " is a retired long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation. [N 1] The SR-71 has several nicknames, including "Blackbird" and "Habu".
Wi-Fi 6, or IEEE 802.11ax, is an IEEE standard from the Wi-Fi Alliance, for wireless networks (WLANs). It operates in the 2.4 GHz and 5 GHz bands,[9] with an extended version, Wi-Fi 6E, that adds the 6 GHz band.[10] It is an upgrade from Wi-Fi 5 (802.11ac), with improvements for better performance in crowded places. Wi-Fi 6 covers frequencies ...
