Problem: Phase change materials such as paraffin wax and Glauber's salt are another thermal storage media. These materials are inexpensive, readily available, and can deliver domestically useful temperatures (approximately 64 C or 147 F). The "Dover House" (in Dover, Massachusetts) was the first to use a Glauber's salt heating system, in 1948. Solar energy can also be stored at high temperatures using molten salts. Salts are an effective storage medium because they are low-cost, have a high specific heat capacity and can deliver heat at temperatures compatible with conventional power systems. The Solar Two used this method of energy storage, allowing it to store 1.44 terajoules (400,000 kWh) in its 68 cubic metres storage tank with an annual storage efficiency of about 99%.
The first Glauber's salt heating system was first used where?
The answer is the following: The "Dover House"

Problem: Before going to Iberia, Napoleon decided to address several lingering issues with the Russians. At the Congress of Erfurt in October 1808, Napoleon hoped to keep Russia on his side during the upcoming struggle in Spain and during any potential conflict against Austria. The two sides reached an agreement, the Erfurt Convention, that called upon Britain to cease its war against France, that recognized the Russian conquest of Finland from Sweden, and that affirmed Russian support for France in a possible war against Austria "to the best of its ability." Napoleon then returned to France and prepared for war. The Grande Armee, under the Emperor's personal command, rapidly crossed the Ebro River in November 1808 and inflicted a series of crushing defeats against the Spanish forces. After clearing the last Spanish force guarding the capital at Somosierra, Napoleon entered Madrid on 4 December with 80,000 troops. He then unleashed his soldiers against Moore and the British forces. The British were swiftly driven to the coast, and they withdrew from Spain entirely after a last stand at the Battle of Corunna in January 1809.
In what year was the Congress of Erfurt held?
The answer is the following: 1808

Problem: Objections to banning the use of incandescent light bulbs include the higher initial cost of alternatives and lower quality of light of fluorescent lamps. Some people have concerns about the health effects of fluorescent lamps. However, even though they contain mercury, the environmental performance of CFLs is much better than that of light bulbs, mostly because they consume much less energy and therefore strongly reduce the environmental impact of power production. LED lamps are even more efficient, and are free of mercury. They are regarded as the best solution in terms of cost effectiveness and robustness.
What are some objections to banning incandescent bulbs?
The answer is the following: higher initial cost of alternatives and lower quality of light of fluorescent lamps

Problem: Hard rock developed into a major form of popular music in the 1970s, with bands such as Led Zeppelin, The Who, Deep Purple, Aerosmith, AC/DC and Van Halen. During the 1980s, some hard rock bands moved away from their hard rock roots and more towards pop rock, while others began to return to a hard rock sound. Established bands made a comeback in the mid-1980s and it reached a commercial peak in the 1980s, with glam metal bands like Bon Jovi and Def Leppard and the rawer sounds of Guns N' Roses, which followed up with great success in the later part of that decade. Hard rock began losing popularity with the commercial success of grunge and later Britpop in the 1990s.
What style did some hard rock bands embrace in the 1980s?
The answer is the following:
pop rock