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Grain size (or particle size) is the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several ...
The megalithic yard is a hypothetical ancient unit of length equal to about 2.72 feet (0.83 m). [1][2][3] Some researchers believe it was used in the construction of megalithic structures. The proposal was made by Alexander Thom as a result of his surveys of 600 megalithic sites in England, Scotland, Wales and Brittany. [4]
It is estimated that the annual consumption of sand and gravel is 40 billion tons and sand is a US$70 billion global industry. [24] With increasing use, more is expected to come from recycling and alternatives to sand. [25] The global demand for sand in 2017 was 9.55 billion tons as part of a $99.5 billion industry. [26]
Ratio of void volume and total volume of a porous material. Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure the "accessible void", the total amount ...
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by ...
0.3048 m. 30.48 cm. 304.8 mm. The foot (standard symbol: ft) [1][2] is a unit of length in the British imperial and United States customary systems of measurement. The prime symbol, ′, is commonly used to represent the foot. [3] In both customary and imperial units, one foot comprises 12 inches, and one yard comprises three feet.
e. In mathematics, the inverse trigonometric functions (occasionally also called antitrigonometric, [1] cyclometric, [2] or arcus functions [3]) are the inverse functions of the trigonometric functions, under suitably restricted domains. Specifically, they are the inverses of the sine, cosine, tangent, cotangent, secant, and cosecant functions ...
Sv. ≡ 1 J/kg [44] = 1 Sv = 1 J/kg = 1 m 2 ⋅s 2. Although the definitions for sievert (Sv) and gray (Gy) would seem to indicate that they measure the same quantities, this is not the case. The effect of receiving a certain dose of radiation (given as Gy) is variable and depends on many factors, thus a new unit was needed to denote the ...