Pressure measurementPressure measurement is the measurement of an applied force by a fluid (liquid or gas) on a surface. Pressure is typically measured in units of force per unit of surface area. Many techniques have been developed for the measurement of pressure and vacuum. Instruments used to measure and display pressure mechanically are called pressure gauges, vacuum gauges or compound gauges (vacuum & pressure). The widely used Bourdon gauge is a mechanical device, which both measures and indicates and is probably the best known type of gauge.
PlasticPlastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use. Plastics typically are made through human industrial systems.
Geothermal gradientGeothermal gradient is the rate of change in temperature with respect to increasing depth in Earth's interior. As a general rule, the crust temperature rises with depth due to the heat flow from the much hotter mantle; away from tectonic plate boundaries, temperature rises in about 25–30 °C/km (72–87 °F/mi) of depth near the surface in most of the world. However, in some cases the temperature may drop with increasing depth, especially near the surface, a phenomenon known as or geothermal gradient.
Carrara marbleCarrara marble, Luna marble to the Romans, is a type of white or blue-grey marble popular for use in sculpture and building decor. It has been quarried since Roman times in the mountains just outside the city of Carrara in the province of Massa and Carrara in the Lunigiana, the northernmost tip of modern-day Tuscany, Italy. More marble has been extracted from the over 650 quarry sites near Carrara than from any other place. The pure white statuario grade was used for monumental sculpture, as "it has a high tensile strength, can take a high gloss polish and holds very fine detail".
CarraraCarrara (kəˈrɑːrə , kaˈraːɾa; Carara, kaˈɾaːɾa) is a city and comune in Tuscany, in central Italy, of the province of Massa and Carrara, and notable for the white or blue-grey marble quarried there. It is on the Carrione River, some west-northwest of Florence. Its motto is Fortitudo mea in rota (Latin: "My strength is in the wheel"). The word Carrara likely comes from the pre-Roman (Celtic or Ligurian) element kar (stone), through Latin carrariae meaning 'quarries'.
Crust (geology)In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Mercury, Venus, Mars, Io, the Moon and other planetary bodies formed via igneous processes and were later modified by erosion, impact cratering, volcanism, and sedimentation.
TectonicsTectonics (; ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. These processes include those of mountain-building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute the Earth's outer shell interact with each other. Principles of tectonics also provide a framework for understanding the earthquake and volcanic belts that directly affect much of the global population.
MarbleMarble is a metamorphic rock consisting of carbonate minerals that recrystallize under the influence of heat, pressure and aqueous solutions, most commonly calcite (CaCO3) or dolomite (CaMg(CO3)2) and has a crystalline texture of varying thickness. Marble is typically not foliated (layered), although there are exceptions. In geology, the term marble refers to metamorphosed limestone, but its use in stonemasonry more broadly encompasses unmetamorphosed limestone. Marble is commonly used for sculpture and as a building material.
