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Rankine's theory (maximum-normal stress theory), developed in 1857 by William John Macquorn Rankine, [1] is a stress field solution that predicts active and passive earth pressure. It assumes that the soil is cohesionless, the wall is frictionless, the soil-wall interface is vertical, the failure surface on which the soil moves is planar , and ...
The soil pH usually increases when the total alkalinity increases, but the balance of the added cations also has a marked effect on the soil pH. For example, increasing the amount of sodium in an alkaline soil tends to induce dissolution of calcium carbonate , which increases the pH.
An example of lateral earth pressure overturning a retaining wall. The lateral earth pressure is the pressure that soil exerts in the horizontal direction. It is important because it affects the consolidation behavior and strength of the soil and because it is considered in the design of geotechnical engineering structures such as retaining walls, basements, tunnels, deep foundations and ...
The Rankine scale is used in engineering systems where heat computations are done using degrees Fahrenheit. [3] The symbol for degrees Rankine is °R [2] (or °Ra if necessary to distinguish it from the Rømer and Réaumur scales). By analogy with the SI unit kelvin, some authors term the unit Rankine, omitting the degree symbol. [4] [5]
William John Macquorn Rankine FRSE FRS (/ ˈ r æ ŋ k ɪ n /; 5 July 1820 – 24 December 1872) was a Scottish mathematician and physicist. He was a founding contributor, with Rudolf Clausius and William Thomson (Lord Kelvin), to the science of thermodynamics , particularly focusing on its First Law.
English: I retrieved the soil pH maps from . In GIMP 2.4.3 I used the "Select by Color Tool" (threshold 15.0) to create pH-specific maps. Note that the original maps do not indicate actual pH values in the pH scale. For soils with acidic pH, I included the colors indicated by the leftmost 14 bars in the pH scale, ranging from red to pink.
The addition of a small amount of lime, Ca(OH) 2, will displace hydronium ions from the soil colloids, causing the fixation of calcium to colloids and the evolution of CO 2 and water, with little permanent change in soil pH. The above are examples of the buffering of soil pH.
Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbonic acid. It can also be a compound such as aluminium sulfate, which reacts in the soil to release protons.