Question: 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 375–395 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 250–270 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).
Try to answer this question if possible: What UV wavelengths are found in non-sterilization devices?
Answer: unanswerable
Question: The skeleton consists of very lightweight bones. They have large air-filled cavities (called pneumatic cavities) which connect with the respiratory system. The skull bones in adults are fused and do not show cranial sutures. The orbits are large and separated by a bony septum. The spine has cervical, thoracic, lumbar and caudal regions with the number of cervical (neck) vertebrae highly variable and especially flexible, but movement is reduced in the anterior thoracic vertebrae and absent in the later vertebrae. The last few are fused with the pelvis to form the synsacrum. The ribs are flattened and the sternum is keeled for the attachment of flight muscles except in the flightless bird orders. The forelimbs are modified into wings.
Try to answer this question if possible: What is formed when vertebrae are fused with the pelvis?
Answer: synsacrum
Question: This is a socio-economic bloc of nations in or near the Caribbean Sea. Other outlying member states include the Co-operative Republic of Guyana and the Republic of Suriname in South America, along with Belize in Central America. The Turks and Caicos Islands, an associate member of CARICOM, and the Commonwealth of The Bahamas, a full member of CARICOM, are in the Atlantic, but near to the Caribbean. Other nearby nations or territories, such as the United States, are not members (although the US Commonwealth of Puerto Rico has observer status, and the United States Virgin Islands announced in 2007 they would seek ties with CARICOM). Bermuda, at roughly a thousand miles from the Caribbean Sea, has little trade with, and little economically in common with, the region, and joined primarily to strengthen cultural links.
Try to answer this question if possible: What commonwealth announced it would seek ties with CARICOM in 2007?
Answer: unanswerable
Question: In 1949, France started its transmissions with an 819 lines system (with 737 active lines). The system was monochrome only, and was used only on VHF for the first French TV channel. It was discontinued in 1983.
Try to answer this question if possible: When was France's 819 line system discontinued?
Answer:
1983