grinding medium
21Coffee roasting — machine Light roasted coffee beans …
22Mineral processing — Crushing, a form of comminution, one of the unit operations of mineral processing In the field of extractive metallurgy, mineral processing, also known as mineral dressing or ore dressing, is the process of separating commercially valuable… …
23machine tool — machine tooled, adj. a power operated machine, as a lathe, used for general cutting and shaping of metal and other substances. [1860 65] * * * Stationary, power driven machine used to cut, shape, or form materials such as metal and wood. Machine… …
24stained glass — stained glass, adj. glass that has been colored, enameled, painted, or stained, esp. by having pigments baked onto its surface or by having various metallic oxides fused into it, as used in church windows, decorative lampshades, etc. [1785 95] *… …
25Stone Age — the period in the history of humankind, preceding the Bronze Age and the Iron Age, and marked by the use of stone implements and weapons: subdivided into the Paleolithic, Mesolithic, and Neolithic periods. [1860 65] * * * First known period of… …
26Dinosaur — For other uses, see Dinosaur (disambiguation). Dinosaurs Temporal range: Late Triassic–Late Cretaceous, 231.4–65.5 Ma …
27Physiology of dinosaurs — Note: In this article dinosaur means non avian dinosaur, since most experts regard birds as an advanced group of dinosaurs. The physiology of dinosaurs has historically been a controversial subject, particularly thermoregulation. Recently, many… …
28mineral processing — or ore dressing Mechanical treatment of crude ores to separate the valuable minerals. Mineral processing was at first applied only to ores of precious metals but later came to be used to recover other metals and nonmetallic minerals. It is also… …
29technology, 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… …
30Speeds and feeds — A line drawing showing some basic concepts of speeds and feeds in the context of lathe work. The angular velocity of the workpiece (rev/min) is called the spindle speed by machinists. Its tangential linear equivalent at the tool cutter interface… …
