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Soil texture determines total volume of the smallest pores; [56] clay soils have smaller pores, but more total pore space than sands, [57] despite a much lower permeability. [58] Soil structure has a strong influence on the larger pores that affect soil aeration , water infiltration and drainage . [ 59 ]
The spatial arrangement of the oxygen atoms determines clay's structure. [19] Half of the weight of clay is oxygen, but on a volume basis oxygen is ninety percent. [ 20 ] The layers of clay are sometimes held together through hydrogen bonds , sodium or potassium bridges and as a result will swell less in the presence of water. [ 21 ]
These conditions are created by the high-temperature fractionation of highly magnesian olivine or pyroxene, which causes a relative iron-enrichment in the residual melt. When the iron content of the melt is sufficiently high, magnetite or ilmenite crystallise and, due to their high density, form cumulate rocks.
Controlling the production process in combination with the characterization of texture and the material's microstructure help to determine the materials properties, i.e. the processing-microstructure-texture-property relationship. [2] [3] [4] Also, geologic rocks show texture due to their thermo-mechanic history of formation processes.
In geology, texture or rock microstructure [1] refers to the relationship between the materials of which a rock is composed. [2] The broadest textural classes are crystalline (in which the components are intergrown and interlocking crystals), fragmental (in which there is an accumulation of fragments by some physical process), aphanitic (in which crystals are not visible to the unaided eye ...
It is the total pore space of soil, not the pore size, and the degree of pore interconnection (or conversely pore sealing), together with water content, air turbulence and temperature, that determine the rate of diffusion of gases into and out of soil.
Carbon content in iron was not implicated as the reason for the differences in properties of wrought iron, cast iron, and steel until the 18th century. [ 92 ] Since iron was becoming cheaper and more plentiful, it also became a major structural material following the building of the innovative first iron bridge in 1778.
Metamorphic rocks are formed when existing rock is transformed physically or chemically at elevated temperature, without actually melting to any great degree. The importance of heating in the formation of metamorphic rock was first noted by the pioneering Scottish naturalist, James Hutton , who is often described as the father of modern geology.