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If the soil is saturated by water, a condition that often exists when the soil is below the water table or sea level, then water fills the gaps between soil grains ('pore spaces'). In response to soil compressing, the pore water pressure increases and the water attempts to flow out from the soil to zones of low pressure (usually upward towards ...
Hydrothermal liquefaction (HTL) is a thermal depolymerization process used to convert wet biomass, and other macromolecules, into crude-like oil under moderate temperature and high pressure. [1] The crude-like oil has high energy density with a lower heating value of 33.8-36.9 MJ/kg and 5-20 wt% oxygen and renewable chemicals.
Use of SPT data for direct prediction of liquefaction potential suffers from roughness of correlations and from the need to "normalize" SPT data to account for overburden pressure, sampling technique, and other factors. [4] Additionally, the method cannot collect accurate data for weak soil layers for several reasons:
Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. The soil moisture curve is characteristic for different types of soil, and is also called the soil moisture characteristic. It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability.
It's the point at which the soil cannot sustain any additional load without undergoing continuous deformation, in a manner similar to the behaviour of fluids. Certain properties of the soil, like porosity, shear strength, and volume, reach characteristic values. These properties are intrinsic to the type of soil and its initial conditions. [1]
As an example of the latter, a "major commercial application of liquefaction is the liquefaction of air to allow separation of the constituents, such as oxygen, nitrogen, and the noble gases." [4] Another is the conversion of solid coal into a liquid form usable as a substitute for liquid fuels. [5]
The Richards equation represents the movement of water in unsaturated soils, and is attributed to Lorenzo A. Richards who published the equation in 1931. [1] It is a quasilinear partial differential equation; its analytical solution is often limited to specific initial and boundary conditions. [2]
Fully saturated soil, equivalent to effective porosity: Field capacity: θ fc: −33 0.1–0.35 Soil moisture 2–3 days after a rain or irrigation Permanent wilting point: θ pwp or θ wp: −1500 0.01–0.25 Minimum soil moisture at which a plant wilts Residual water content θ r: −∞ 0.001–0.1 Remaining water at high tension