QUES: Phosphor-based LED efficiency losses are due to the heat loss from the Stokes shift and also other phosphor-related degradation issues. Their luminous efficacies compared to normal LEDs depend on the spectral distribution of the resultant light output and the original wavelength of the LED itself. For example, the luminous efficacy of a typical YAG yellow phosphor based white LED ranges from 3 to 5 times the luminous efficacy of the original blue LED because of the human eye's greater sensitivity to yellow than to blue (as modeled in the luminosity function). Due to the simplicity of manufacturing the phosphor method is still the most popular method for making high-intensity white LEDs. The design and production of a light source or light fixture using a monochrome emitter with phosphor conversion is simpler and cheaper than a complex RGB system, and the majority of high-intensity white LEDs presently on the market are manufactured using phosphor light conversion.
What do phosphor-based LEDs luminous efficacies depend on?

ANS: the spectral distribution of the resultant light output

QUES: A cappella music was originally used in religious music, especially church music as well as anasheed and zemirot. Gregorian chant is an example of a cappella singing, as is the majority of secular vocal music from the Renaissance. The madrigal, up until its development in the early Baroque into an instrumentally-accompanied form, is also usually in a cappella form. Jewish and Christian music were originally a cappella,[citation needed] and this practice has continued in both of these religions as well as in Islam.
What was considered part of a cappella following the Baroque period?

ANS: unanswerable

QUES: In many non-US western countries a 'fourth hurdle' of cost effectiveness analysis has developed before new technologies can be provided. This focuses on the efficiency (in terms of the cost per QALY) of the technologies in question rather than their efficacy. In England and Wales NICE decides whether and in what circumstances drugs and technologies will be made available by the NHS, whilst similar arrangements exist with the Scottish Medicines Consortium in Scotland, and the Pharmaceutical Benefits Advisory Committee in Australia. A product must pass the threshold for cost-effectiveness if it is to be approved. Treatments must represent 'value for money' and a net benefit to society.
What threshold must a drug pass before it is approved?

ANS: cost-effectiveness

QUES: According to some estimates about 20% of the population lives on less than US$1.25 per day. Migration from Tajikistan and the consequent remittances have been unprecedented in their magnitude and economic impact. In 2010, remittances from Tajik labour migrants totaled an estimated $2.1 billion US dollars, an increase from 2009. Tajikistan has achieved transition from a planned to a market economy without substantial and protracted recourse to aid (of which it by now receives only negligible amounts), and by purely market-based means, simply by exporting its main commodity of comparative advantage cheap labor. The World Bank Tajikistan Policy Note 2006 concludes that remittances have played an important role as one of the drivers of Tajikistan's robust economic growth during the past several years, have increased incomes, and as a result helped significantly reduce poverty.
Ninety percent of the population lives on less then what?

ANS:
unanswerable