pipe-layer
51igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary …
52Speed of sound — Sound is a vibration that travels through an elastic medium as a wave. The speed of sound describes how much distance such a wave travels in a certain amount of time. In SI Units with dry air at 20 °C (68 °F), the speed of sound is 343 m/s. This… …
53Brazing — This article is about the metal joining process. For the cooking technique, see braising. Brazing practice Brazing is a metal joining process whereby a filler metal is heated above and distributed between two or more close fitting parts by… …
54Water purification — This article is about large scale, municipal water purification. For portable/emergency water purification, see portable water purification. For industrial water purification, see deionized water. For distilled water, see distilled water. Water… …
55Stainless steel — Iron alloy phases Ferrite (α iron, δ iron) Austenite (γ iron) Pearlite (88% ferrite, 12% cementite) …
56Earth sheltering — is the architectural practice of using earth against building walls for external thermal mass, to reduce heat loss, and to easily maintain a steady indoor air temperature. Earth sheltering is popular in modern times among advocates of passive… …
57Limnic eruption — A limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which carbon dioxide (CO2) suddenly erupts from deep lake water, suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in …
58Optical fiber — A bundle of optical fibers A TOSLINK fiber optic audio c …
59Trickling filter — A trickling filter consists of a fixed bed of rocks, gravel, slag, polyurethane foam, sphagnum peat moss, or plastic media over which sewage or other wastewater flows downward and causes a layer or film of microbial slime to grow, covering the… …
60Organ Pipes National Park — IUCN Category III (Natural Monument) …
