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With nitrides containing aluminium, most often AlGaN and AlGaInN, even shorter wavelengths are achievable. Ultraviolet LEDs in a range of wavelengths are becoming available on the market. Near-UV emitters at wavelengths around 375395 nm are already cheap and often encountered, for example, as black light lamp replacements for inspection of anti-counterfeiting UV watermarks in some documents and paper currencies. Shorter-wavelength diodes, while substantially more expensive, are commercially available for wavelengths down to 240 nm. As the photosensitivity of microorganisms approximately matches the absorption spectrum of DNA, with a peak at about 260 nm, UV LED emitting at 250270 nm are to be expected in prospective disinfection and sterilization devices. Recent research has shown that commercially available UVA LEDs (365 nm) are already effective disinfection and sterilization devices. UV-C wavelengths were obtained in laboratories using aluminium nitride (210 nm), boron nitride (215 nm) and diamond (235 nm).
What is the range of wavelengths for cheap UV LEEDs?
A: unanswerable

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Shortly after he learned of the failure of Menshikov's diplomacy toward the end of June 1853, the Tsar sent armies under the commands of Field Marshal Ivan Paskevich and General Mikhail Gorchakov across the Pruth River into the Ottoman-controlled Danubian Principalities of Moldavia and Wallachia. Fewer than half of the 80,000 Russian soldiers who crossed the Pruth in 1853 survived. By far, most of the deaths would result from sickness rather than combat,:118119 for the Russian army still suffered from medical services that ranged from bad to none.
Who was in control of the Danubian Principalities?
A: Ottoman

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In Britain, further experiments in the genre boosted its appeal. House and rave clubs such as Lakota and Cream emerged across Britain, hosting house and dance scene events. The 'chilling out' concept developed in Britain with ambient house albums such as The KLF's Chill Out and Analogue Bubblebath by Aphex Twin. The Godskitchen superclub brand also began in the midst of the early 90's rave scene. After initially hosting small nights in Cambridge and Northampton, the associated events scaled up in Milton Keynes, Birmingham and Leeds. A new indie dance scene also emerged in the 90's. In New York, bands such as Deee-Lite furthered house's international influence. Two distinctive tracks from this era were the Orb's "Little Fluffy Clouds" (with a distinctive vocal sample from Rickie Lee Jones) and the Happy Mondays' "Wrote for Luck" ("WFL") which was transformed into a dance hit by Vince Clarke.
who released the track "little fluffy clouds"?
A: Orb

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In-mid 2015, China started the build-up of the third generation BeiDou system (BDS-3) in the global coverage constellation. The first BDS-3 satellite was launched 30 September 2015. As of March 2016, 4 BDS-3 in-orbit validation satellites have been launched.
When was the first BDS-3 satellite launched?
A:
30 September 2015