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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 ...
One accepted scientific hypothesis is that the Earth was formed by accretion of material with a chondritic composition through impacts with differentiated planetesimals. . During this accretionary phase, planetary differentiation separated the Earth's core, where heavy metallic siderophile elements accumulated, from the surrounding undifferentiated primitive mantl
Knowing that the Inuit had made tools from the Cape York meteorite, mainly due to Sir John Ross' discovery that the natives of Greenland used iron knives, Nordenskiöld landed at Fortune Bay on Disko Island to search for the material. The Inuit had told Ross that they got the iron from high on a mountain, at a site where two large boulders lay.
One theory suggests that metallurgy was introduced through Central Asia. [36] In 2008, two iron fragments were excavated at the Mogou site, in Gansu. They have been dated to the 14th century BC, belonging to the period of Siwa culture, suggesting an independent Chinese origin. One of the fragments was made of bloomery iron rather than ...
The iron cycle is an important component of the terrestrial ecosystems. The ferrous form of iron, Fe 2+, is dominant in the Earth's mantle, core, or deep crust. The ferric form, Fe 3+, is more stable in the presence of oxygen gas. [22] Dust is a key component in the Earth's iron cycle.
Due to the need to deliver necessary raw materials (such as oil, weapons, ammunition, food and drugs) through mined river currents, Adolf Hitler ordered the production of 50 concrete ships for different purposes. Most were concrete barges made for oil transportation from Romania, and needed raw materials that were driven to the Baltic front.
Schematic of the Earth's inner core and outer core motion and the magnetic field it generates. The Earth's inner core is thought to be slowly growing as the liquid outer core at the boundary with the inner core cools and solidifies due to the gradual cooling of the Earth's interior (about 100 degrees Celsius per billion years). [49]
Cementite (or iron carbide) is a compound of iron and carbon, more precisely an intermediate transition metal carbide with the formula Fe 3 C. By weight, it is 6.67% carbon and 93.3% iron.