Question: In September 1961, while working at Texas Instruments in Dallas, Texas, James R. Biard and Gary Pittman discovered near-infrared (900 nm) light emission from a tunnel diode they had constructed on a GaAs substrate. By October 1961, they had demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically-isolated semiconductor photodetector. On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc diffused pn junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias. After establishing the priority of their work based on engineering notebooks predating submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs, and Lincoln Lab at MIT, the U.S. patent office issued the two inventors the patent for the GaAs infrared (IR) light-emitting diode (U.S. Patent US3293513), the first practical LED. Immediately after filing the patent, Texas Instruments (TI) began a project to manufacture infrared diodes. In October 1962, TI announced the first LED commercial product (the SNX-100), which employed a pure GaAs crystal to emit a 890 nm light output. In October 1963, TI announced the first commercial hemispherical LED, the SNX-110.
Try to answer this question if possible: What type of diode was used to help discover non-infrared light emission?
Answer: unanswerable
Question: Zinc is more reactive than iron or steel and thus will attract almost all local oxidation until it completely corrodes away. A protective surface layer of oxide and carbonate (Zn
5(OH)
6(CO
3)
2) forms as the zinc corrodes. This protection lasts even after the zinc layer is scratched but degrades through time as the zinc corrodes away. The zinc is applied electrochemically or as molten zinc by hot-dip galvanizing or spraying. Galvanization is used on chain-link fencing, guard rails, suspension bridges, lightposts, metal roofs, heat exchangers, and car bodies.
Try to answer this question if possible: What explodes as zinc corrodes?
Answer: unanswerable
Question: In 1977, Gaddafi dissolved the Republic and created a new socialist state, the Jamahiriya ("state of the masses"). Officially adopting a symbolic role in governance, he retained power as military commander-in-chief and head of the Revolutionary Committees responsible for policing and suppressing opponents. Overseeing unsuccessful border conflicts with Egypt and Chad, Gaddafi's support for foreign militants and alleged responsibility for the Lockerbie bombing led to Libya's label of "international pariah". A particularly hostile relationship developed with the United States and United Kingdom, resulting in the 1986 U.S. bombing of Libya and United Nations-imposed economic sanctions. Rejecting his earlier ideological commitments, from 1999 Gaddafi encouraged economic privatization and sought rapprochement with Western nations, also embracing Pan-Africanism and helping to establish the African Union. Amid the Arab Spring, in 2011 an anti-Gaddafist uprising led by the National Transitional Council (NTC) broke out, resulting in the Libyan Civil War. NATO intervened militarily on the side of the NTC, bringing about the government's downfall. Retreating to Sirte, Gaddafi was captured and killed by NTC militants.
Try to answer this question if possible: List two reasons why Libya become an "international pariah."
Answer: Overseeing unsuccessful border conflicts with Egypt and Chad, Gaddafi's support for foreign militants and alleged responsibility for the Lockerbie bombing
Question: 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.
Try to answer this question if possible: How many BDS-20 satellites have been launched?
Answer:
unanswerable