Search results
Results from the WOW.Com Content Network
Ferrocement or ferro-cement [1] is a system of construction using reinforced mortar [2] or plaster (lime or cement, sand, and water) applied over an "armature" of metal mesh, woven, expanded metal, or metal-fibers, and closely spaced thin steel rods such as rebar. The metal commonly used is iron or some type of steel, and the mesh is made with ...
A modern ferrocerium firesteel product is composed of an alloy of rare-earth metals called mischmetal, containing approximately 20.8% iron, 41.8% cerium, about 4.4% each of praseodymium, neodymium, and magnesium, plus 24.2% lanthanum. [5] A variety of other components are added to modify the spark and processing characteristics. [2]
[2]: 171 Convection in the Earth's outer core drives the geodynamo that is the source of the Earth's magnetic field. [3]: Chapter 8 In the ocean, convection can be thermal (driven by heat), haline (where the buoyancy is due to differences in salinity), or thermohaline, a combination of the two. [4]
Primordial heat is the heat lost by the Earth as it continues to cool from its original formation, and this is in contrast to its still actively-produced radiogenic heat. The Earth core's heat flow—heat leaving the core and flowing into the overlying mantle—is thought to be due to primordial heat, and is estimated at 5–15 TW. [23]
Heat domes can arise in still and dry summer conditions, when a mass of warm air builds up, and the high pressure from the Earth's atmosphere pushes the warm air down. The air is then compressed, and as its net heat is now in a smaller volume, it increases in temperature.
The Earth is cooling, and the resulting heat flow generates the Earth's magnetic field through the geodynamo and plate tectonics through mantle convection. [13] The main sources of heat are: primordial heat due to Earth's cooling and radioactivity in the planets upper crust. [14] There is also some contributions from phase transitions.
Geodynamics is a broad field which combines observations from many different types of geological study into a broad picture of the dynamics of Earth. Close to the surface of the Earth, data includes field observations, geodesy, radiometric dating, petrology, mineralogy, drilling boreholes and remote sensing techniques. However, beyond a few ...
Earth's outer core is a fluid layer about 2,260 km (1,400 mi) thick, composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. [ 1 ] [ 2 ] [ 3 ] The outer core begins approximately 2,889 km (1,795 mi) beneath Earth's surface at the core-mantle boundary and ends 5,150 km (3,200 mi) beneath Earth's surface ...