Problem: Light-emitting diode:

Among the challenges being faced to improve the efficiency of LED-based white light sources is the development of more efficient phosphors. As of 2010, the most efficient yellow phosphor is still the YAG phosphor, with less than 10% Stoke shift loss. Losses attributable to internal optical losses due to re-absorption in the LED chip and in the LED packaging itself account typically for another 10% to 30% of efficiency loss. Currently, in the area of phosphor LED development, much effort is being spent on optimizing these devices to higher light output and higher operation temperatures. For instance, the efficiency can be raised by adapting better package design or by using a more suitable type of phosphor. Conformal coating process is frequently used to address the issue of varying phosphor thickness.

 What is the least efficient yellow phosphor?
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A: unanswerable


Problem: Pharmaceutical industry:

By the 1890s the profound effect of adrenal extracts on many different tissue types had been discovered, setting off a search both for the mechanism of chemical signalling and efforts to exploit these observations for the development of new drugs. The blood pressure raising and vasoconstrictive effects of adrenal extracts were of particular interest to surgeons as hemostatic agents and as treatment for shock, and a number of companies developed products based on adrenal extracts containing varying purities of the active substance. In 1897 John Abel of Johns Hopkins University identified the active principle as epinephrine, which he isolated in an impure state as the sulfate salt. Industrial chemist Jokichi Takamine later developed a method for obtaining epinephrine in a pure state, and licensed the technology to Parke Davis. Parke Davis marketed epinephrine under the trade name Adrenalin. Injected epinephrine proved to be especially efficacious for the acute treatment of asthma attacks, and an inhaled version was sold in the United States until 2011 (Primatene Mist). By 1929 epinephrine had been formulated into an inhaler for use in the treatment of nasal congestion.

Who identified the inactive substance?
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A: unanswerable


Problem: Dutch language:

Voicing of pre-vocalic initial voiceless alveolar fricatives occurs, although less in Dutch than in German (Du zeven, Germ sieben [z] vs. Eng seven and LG seven [s]), and also the shift in /θ/ > /d/. Dutch shares only with Low German the development of /xs/ > /ss/ (Du vossen, ossen and LG Vösse, Ossen vs. Germ Füchse, Ochsen and Eng foxes, oxen), and also the development of /ft/ → /xt/ though it is far more common in Dutch (Du zacht and LG sacht vs. Germ sanft and Eng soft, but Du kracht vs. LG/Germ kraft and Eng cognate craft).

Although spelled differently, the first consonant of what Dutch word for "seven" is pronounced the same as its German counterpart?
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A: zeven


Problem: Education:

Autodidacticism (also autodidactism) is a contemplative, absorbing process, of "learning on your own" or "by yourself", or as a self-teacher. Some autodidacts spend a great deal of time reviewing the resources of libraries and educational websites. One may become an autodidact at nearly any point in one's life. While some may have been informed in a conventional manner in a particular field, they may choose to inform themselves in other, often unrelated areas. Notable autodidacts include Abraham Lincoln (U.S. president), Srinivasa Ramanujan (mathematician), Michael Faraday (chemist and physicist), Charles Darwin (naturalist), Thomas Alva Edison (inventor), Tadao Ando (architect), George Bernard Shaw (playwright), Frank Zappa (composer, recording engineer, film director), and Leonardo da Vinci (engineer, scientist, mathematician).

 Which famous inventor was not an Autodidact?
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A:
unanswerable