metal deposit
51Fouling — This article is about fouling in engineering. For uses of the term foul outside technology, see Foul (disambiguation). Not to be confused with fowling. Heat exchanger in a steam power plant, fouled by macro fouling …
52money — moneyless, adj. /mun ee/, n., pl. moneys, monies, adj. n. 1. any circulating medium of exchange, including coins, paper money, and demand deposits. 2. See paper money. 3. gold, silver, or other metal in pieces of convenient form stamped by public …
53Antimony — This article is about the element. For the town, see Antimony, Utah. Not to be confused with Antinomy, a type of paradox. tin ← antimony → tellurium As ↑ Sb ↓ Bi …
54Vacuum tube — This article is about the electronic device. For experiments in an evacuated pipe, see free fall. For the transport system, see pneumatic tube. Modern vacuum tubes, mostly miniature style In electronics, a vacuum tube, electron tube (in North… …
55art conservation and restoration — Maintenance and preservation of works of art, their protection from future damage, deterioration, or neglect, and the repair or renovation of works that have deteriorated or been damaged. Research in art history has relied heavily on 20th and… …
56Mining — This article is about the extraction of geological materials from the Earth. For the municipality in Austria, see Mining, Austria. For the siege tactic, see Mining (military). For name of the Chinese emperor, see Daoguang Emperor. Simplified… …
57Ore — For other uses, see Ore (disambiguation). Iron ore (Banded iron formation) …
58platinum group — ▪ chemical element group Introduction six metals, in order of increasing atomic weight, ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and …
59Pebble Mine — Infobox Settlement name = Pebble prospect pushpin pushpin label position = left pushpin map caption = Location of the Pebble prospect in Alaska pushpin mapsize = subdivision type = Country subdivision name = United States subdivision type1 =… …
60steel — steellike, adj. /steel/, n. 1. any of various modified forms of iron, artificially produced, having a carbon content less than that of pig iron and more than that of wrought iron, and having qualities of hardness, elasticity, and strength varying …
