Problem: Light-emitting diode:

By the late 1990s, blue LEDs became widely available. They have an active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN, called cladding layers. By varying the relative In/Ga fraction in the InGaN quantum wells, the light emission can in theory be varied from violet to amber. Aluminium gallium nitride (AlGaN) of varying Al/Ga fraction can be used to manufacture the cladding and quantum well layers for ultraviolet LEDs, but these devices have not yet reached the level of efficiency and technological maturity of InGaN/GaN blue/green devices. If un-alloyed GaN is used in this case to form the active quantum well layers, the device will emit near-ultraviolet light with a peak wavelength centred around 365 nm. Green LEDs manufactured from the InGaN/GaN system are far more efficient and brighter than green LEDs produced with non-nitride material systems, but practical devices still exhibit efficiency too low for high-brightness applications.[citation needed]

How can light emission be varied from violet to amber?
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A: By varying the relative In/Ga fraction in the InGaN quantum wells


Problem: Southampton City Council consists of 48 councillors, 3 for each of the 16 wards. Council elections are held in early May for one third of the seats (one councillor for each ward), elected for a four-year term, so there are elections three years out of four. Since the 2015 council elections, the composition of the council is:
In how many years of every four is a council election held in Southampton?
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Answer: three


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Only the Theravada school does not include the Mahayana scriptures in its canon. As the modern Theravada school is descended from a branch of Buddhism that diverged and established itself in Sri Lanka prior to the emergence of the Mahayana texts, debate exists as to whether the Theravada were historically included in the hinayana designation; in the modern era, this label is seen as derogatory, and is generally avoided.
What school does not include the Mahayava scriptures in its canon?
A: the Theravada


Context and question: Losing the First Sino-Japanese War of 1894–1895 was a watershed. Japan, a country long regarded by the Chinese as little more than an upstart nation of pirates, annihilated the Qing government's modernized Beiyang Fleet, then deemed to be the strongest naval force in Asia. The Japanese victory occurred a mere three decades after the Meiji Restoration set a feudal Japan on course to emulate the Western nations in their economic and technological achievements. Finally, in December 1894, the Qing government took concrete steps to reform military institutions and to re-train selected units in westernized drills, tactics and weaponry. These units were collectively called the New Army. The most successful of these was the Beiyang Army under the overall supervision and control of a former Huai Army commander, General Yuan Shikai, who used his position to build networks of loyal officers and eventually become President of the Republic of China.
Who became the President of the Republic of China?
Answer: General Yuan Shikai


Question: Feynman attended Far Rockaway High School, a school in Far Rockaway, Queens also attended by fellow Nobel laureates Burton Richter and Baruch Samuel Blumberg. Upon starting high school, Feynman was quickly promoted into a higher math class. An unspecified school-administered IQ test estimated his IQ at 123—high, but "merely respectable" according to biographer James Gleick. When he turned 15, he taught himself trigonometry, advanced algebra, infinite series, analytic geometry, and both differential and integral calculus. In high school he was developing the mathematical intuition behind his Taylor series of mathematical operators. Before entering college, he was experimenting with and deriving mathematical topics such as the half-derivative using his own notation.
Is there an answer to this question: What high school did Feynman get expelled from?

Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The conceptual view provides a level of indirection between internal and external. On one hand it provides a common view of the database, independent of different external view structures, and on the other hand it abstracts away details of how the data are stored or managed (internal level). In principle every level, and even every external view, can be presented by a different data model. In practice usually a given DBMS uses the same data model for both the external and the conceptual levels (e.g., relational model). The internal level, which is hidden inside the DBMS and depends on its implementation, requires a different level of detail and uses its own types of data structure types.
What does the conceptual view offer?
A:
a level of indirection between internal and external