copper-hardened gold
61Casting (metalworking) — Casting iron in a sand mold In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which… …
62technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
63Body piercing materials — In modern Western body piercing, a wide variety of materials are used. Some cannot be autoclaved, and others are may induce allergic reactions, or harbour bacteria. Certain countries, such as those belonging to the EU, have legal regulations… …
64military technology — Introduction range of weapons, equipment, structures, and vehicles used specifically for the purpose of fighting. It includes the knowledge required to construct such technology, to employ it in combat, and to repair and replenish it.… …
65jewelry — /jooh euhl ree/, n. 1. articles of gold, silver, precious stones, etc., for personal adornment. 2. any ornaments for personal adornment, as necklaces or cuff links, including those of base metals, glass, plastic, or the like. Also, esp. Brit.,… …
66silver processing — Introduction preparation of the ore for use in various products. Silver has long been valued for its white metallic lustre, its ability to be readily worked, and its resistance to the corrosive effects of moisture and oxygen. The… …
67Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
68Iron — Fe redirects here. For other uses, see Fe (disambiguation). This article is about the chemical element. For other uses, see Iron (disambiguation). manganese …
69Electrical discharge machining — An electrical discharge machine Electric discharge machining (EDM), sometimes colloquially also referred to as spark machining, spark eroding, burning, die sinking or wire erosion,[1] is a manufacturing process whereby a desired shape is obtained …
70Tumbaga — was the name given by Spaniards to a non specific alloy of gold and copper which they found in widespread use in pre Columbian Mesoamerica.Composition and propertiesTumbaga is an alloy composed mostly of gold and copper. It has a significantly… …
