Permeability, permeable, and semipermeable may refer to:

Chemistry

Semipermeable membrane Semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecul ...

, a membrane which will allow certain molecules or ions to pass through it by diffusion *

Vascular permeability Vascular permeability, often in the form of capillary permeability or microvascular permeability, characterizes the capacity of a blood vessel wall to allow for the flow of small molecules (drugs, nutrients, water, ions) or even whole cells (lymph ...

, the movement of fluids and molecules between the vascular and extravascular compartments *

Permeation In physics and engineering, permeation (also called imbuing) is the penetration of a permeate (a fluid such as a liquid, gas, or vapor) through a solid. It is directly related to the concentration gradient of the permeate, a material's intrinsic ...

of a gas or vapor through a solid substance

Earth and soil science

* Permeability (earth sciences), a measure of the ability of a material (such as rocks) to transmit fluids **

Relative permeability In multiphase flow in porous media, the relative permeability of a phase is a dimensionless measure of the effective permeability of that phase. It is the ratio of the effective permeability of that phase to the absolute permeability. It can be ...

, in multiphase flow in porous media *

Permeability (foundry sand) Permeability is a property of foundry sand with respect to how well the sand can vent, ''i.e.'' how well gases pass through the sand. And in other words, permeability is the property by which we can know the ability of material to transmit fluid/ ...

, a test of the venting characteristics of a rammed foundry sand *

Hydraulic conductivity Hydraulic conductivity, symbolically represented as (unit: m/s), is a property of porous materials, soils and rocks, that describes the ease with which a fluid (usually water) can move through the pore space, or fractures network. It depends on th ...

, the permeability of soil for water

Electromagnetism

Permeability (electromagnetism) In electromagnetism, permeability is the measure of magnetization that a material obtains in response to an applied magnetic field. Permeability is typically represented by the (italicized) Greek letter ''μ''. The term was coined by William ...

, the degree of magnetization of a material in response to a magnetic field **

Vacuum permeability The vacuum magnetic permeability (variously ''vacuum permeability'', ''permeability of free space'', ''permeability of vacuum''), also known as the magnetic constant, is the magnetic permeability in a classical vacuum. It is a physical constant, ...

, permeability of free space or magnetic constant, a physical constant, the value of magnetic permeability in a classical vacuum

Vehicles and transport

* Permeability (nautical), in ship design, the percentage of empty space in a compartment or tank *

Permeability (spatial and transport planning) Permeability or connectivity describes the extent to which urban forms permit (or restrict) movement of people or vehicles in different directions. The terms are often used interchangeably, although differentiated definitions also exist (see belo ...

, the extent to which the layout of urban forms enables people or vehicles to move in different directions

Other uses

Air permeability Textile fibers, threads, yarns and fabrics are measured in a multiplicity of units. * A fiber, a single filament of natural material, such as cotton, linen or wool, or artificial material such as nylon, polyester, metal or mineral fiber, or man-m ...

, characteristic of textile fabrics, measuring the ease of passage of air through them * "Impermeable" (song), a song by Ha*Ash *

Permeable Press Permeable Press was a San Francisco-based literary publishing company founded in 1990 by Brian Charles Clark. A "micropress" operating on less than U.S.$100,000 per year, Permeable published a number of trade paperback books, chapbooks, and the li ...

, an American publishing company {{disambiguation