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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.

What were the major advantages of the tantalum light filament?
Answer: These lamps were more efficient than even graphitized carbon filaments and could operate at higher temperatures.
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In December 1547, Francis was in Malacca (Malaysia) waiting to return to Goa (India) when he met a low-ranked samurai named Anjiro (possibly spelled "Yajiro"). Anjiro was not an intellectual, but he impressed Xavier because he took careful notes of everything he said in church. Xavier made the decision to go to Japan in part because this low-ranking samurai convinced him in Portuguese that the Japanese people were highly educated and eager to learn. They were hard workers and respectful of authority. In their laws and customs they were led by reason, and, should the Christian faith convince them of its truth, they would accept it en masse.

In what language did Anjiro speak to Xavier?
Answer: Portuguese
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Rocket-propelled grenades can be—and often are—used against hovering helicopters (e.g., by Somali militiamen during the Battle of Mogadishu (1993)). Firing an RPG at steep angles poses a danger to the user, because the backblast from firing reflects off the ground. In Somalia, militia members sometimes welded a steel plate in the exhaust end of an RPG's tube to deflect pressure away from the shooter when shooting up at US helicopters. RPGs are used in this role only when more effective weapons are not available.

An RPG fired at a steep angle has what reflecting off the ground?
Answer:
the backblast