Article: In the Soviet Union, in the 1970s, a comparison was made between systems electrified at 3 kV DC and 25 kV AC (50 Hz). The results showed that percentage losses in the overhead wires (catenary and contact wires) was over 3 times greater for 3 kV DC than for 25 kV AC. But when the conversion losses were all taken into account and added to overhead wire losses (including cooling blower energy) the 25 kV AC lost a somewhat higher percent of energy than for 3 kV DC. Thus in spite of the much higher losses in the catenary, the 3 kV DC was a little more energy efficient than AC in providing energy from the USSR power grid to the terminals of the traction motors (all DC at that time). While both systems use energy in converting higher voltage AC from the USSR's power grid to lower voltage DC, the conversions for the DC system all took place (at higher efficiency) in the railway substation, while most of the conversion for the AC system took place inside the locomotive (at lower efficiency). Consider also that it takes energy to constantly move this mobile conversion hardware over the rails while the stationary hardware in the railway substation doesn't incur this energy cost. For more details see: Wiki: Soviet Union DC vs. AC.

Question: What came with lesser lesser cost mobile conversion hardware or stationary hardware?
Ans: stationary hardware


Article: Because it is normal to have bacterial colonization, it is difficult to know which chronic wounds are infected. Despite the huge number of wounds seen in clinical practice, there are limited quality data for evaluated symptoms and signs. A review of chronic wounds in the Journal of the American Medical Association's "Rational Clinical Examination Series" quantified the importance of increased pain as an indicator of infection. The review showed that the most useful finding is an increase in the level of pain [likelihood ratio (LR) range, 11-20] makes infection much more likely, but the absence of pain (negative likelihood ratio range, 0.64-0.88) does not rule out infection (summary LR 0.64-0.88).

Question: What is increased pain an indicator of?
Ans: infection


Article: Chopin's music remains very popular and is regularly performed, recorded and broadcast worldwide. The world's oldest monographic music competition, the International Chopin Piano Competition, founded in 1927, is held every five years in Warsaw. The Fryderyk Chopin Institute of Poland lists on its website over eighty societies world-wide devoted to the composer and his music. The Institute site also lists nearly 1,500 performances of Chopin works on YouTube as of January 2014.

Question: What year was the International Chopin Piano Competition founded?
Ans: 1927


Article: Tidewater glaciers are glaciers that terminate in the sea, including most glaciers flowing from Greenland, Antarctica, Baffin and Ellesmere Islands in Canada, Southeast Alaska, and the Northern and Southern Patagonian Ice Fields. As the ice reaches the sea, pieces break off, or calve, forming icebergs. Most tidewater glaciers calve above sea level, which often results in a tremendous impact as the iceberg strikes the water. Tidewater glaciers undergo centuries-long cycles of advance and retreat that are much less affected by the climate change than those of other glaciers.

Question: How are icebergs formed?
Ans:
As the ice reaches the sea, pieces break off, or calve