Problem: In 1902, the Siemens company developed a tantalum lamp filament. These lamps were more efficient than even graphitized carbon filaments and could operate at higher temperatures. Since tantalum metal has a lower resistivity than carbon, the tantalum lamp filament was quite long and required multiple internal supports. The metal filament had the property of gradually shortening in use; the filaments were installed with large loops that tightened in use. This made lamps in use for several hundred hours quite fragile. Metal filaments had the property of breaking and re-welding, though this would usually decrease resistance and shorten the life of the filament. General Electric bought the rights to use tantalum filaments and produced them in the US until 1913.
Who developed the tantalum light filament in 1905?
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Answer: unanswerable


Problem: In March 1949, as RCA released the 45, Columbia released several hundred 7 inch 33 1/3 rpm small spindle hole singles. This format was soon dropped as it became clear that the RCA 45 was the single of choice and the Columbia 12 inch LP would be the 'album' of choice. The first release of the 45 came in seven colors: black 47-xxxx popular series, yellow 47-xxxx juvenile series, green (teal) 48-xxxx country series, deep red 49-xxxx classical series, bright red (cerise) 50-xxxx blues/spiritual series, light blue 51-xxxx international series, dark blue 52-xxxx light classics. All colors were soon dropped in favor of black because of production problems. However, yellow and deep red were continued until about 1952. The first 45 rpm record created for sale was "PeeWee the Piccolo" RCA 47-0147 pressed in yellow translucent vinyl at the Sherman Avenue plant, Indianapolis Dec. 7, 1948, R.O. Price, plant manager.
How many colors were 45s available in when first released?
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Answer: seven colors


Problem: Little is known about the bacteria that degrade cellulose. Symbiotic bacteria in Xylophaga may play a role in the degradation of sunken wood; while bacteria such as Alphaproteobacteria, Flavobacteria, Actinobacteria, Clostridia, and Bacteroidetes have been detected in wood submerged over a year.
What component of wood is degraded by bacteria that scientists are still trying to learn about?
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Answer:
cellulose