sliding forms
41Tertiary Period — Interval of geologic time, 65–1. 8 million years ago. It constitutes the first of the two periods of the Cenozoic Era, the second being the Quaternary. The Tertiary has five subdivisions: (from oldest to youngest) the Paleocene, Eocene, Oligocene …
42gasoline engine — Most widely used form of internal combustion engine, found in most automobiles and many other vehicles. Gasoline engines vary significantly in size, weight per unit of power generated, and arrangement of components. The principal type is the… …
43Glossary of rail terminology — Rail transport Operations Track Maintenance High speed Gauge Stations …
44Plate tectonics — The tectonic plates of the world were mapped in the second half of the 20th century …
45Softball — This article is about the sport. For other uses, see Soft ball (disambiguation). Softball Highest governing body International Softball Federation First played United States, 1887 Characteristics …
46Viscoplasticity — Figure 1. Elements used in one dimensional models of viscoplastic materials. Viscoplasticity is a theory in continuum mechanics that describes the rate dependent inelastic behavior of solids. Rate dependence in this context means that the… …
47percussion instrument — a musical instrument, as the drum, cymbal, triangle, xylophone, or piano, that is struck to produce a sound, as distinguished from string or wind instruments. [1870 75] * * * A musical instrument that is struck (or sometimes shaken or scraped) to …
48textile — /teks tuyl, til/, n. 1. any cloth or goods produced by weaving, knitting, or felting. 2. a material, as a fiber or yarn, used in or suitable for weaving: Glass can be used as a textile. adj. 3. woven or capable of being woven: textile fabrics. 4 …
49lubrication — See lubricate. * * * Introduction of any of various substances between sliding surfaces to reduce wear and friction. Lubricants may secondarily control corrosion, regulate temperature, electrically insulate, remove contaminants, or damp shock.… …
50keyboard instrument — ▪ music Introduction any musical instrument on which different notes can be sounded by pressing a series of keys, push buttons, or parallel levers. In nearly all cases in Western music the keys correspond to consecutive notes in the… …
