propustností

Propustnost is the property of a material, barrier, or system that describes its ability to allow substances or signals to pass through it. The term is used across disciplines with slightly different emphases: in hydrology and soil science it refers to the ease with which fluids move through a pore network; in membrane science it concerns the passage of molecules across a selective barrier; in civil engineering it relates to how quickly water can infiltrate soil or permeable pavement; in information technology it is used to denote throughput, the maximum rate at which data can be transmitted through a network or device.

In porous media, permeability is a material property that depends on pore geometry and connectivity. Larger, better connected pores and lower fluid viscosity increase permeability, while tortuosity and partial saturation reduce it. Permeability is often discussed alongside porosity, the fraction of void space, and is a key parameter in Darcy’s law, which describes fluid flow through a permeable medium. The effective permeability can be influenced by saturation, temperature, and chemical interactions with the pore walls.

In membranes, the permeability coefficient describes how readily molecules cross a barrier and is assessed by permeation and diffusion experiments. Different mechanisms, such as solution-diffusion or pore flow, determine how permeability relates to selectivity and flux. Permeability is central to designing filtration systems, gas separation membranes, and related technologies.

In civil engineering and urban planning, propustnost governs drainage and flood risk. Permeable pavements, infiltration basins, and similar systems are designed to maximise water infiltration and groundwater recharge, with infiltration rates often expressed in millimetres per hour.

In information technology, throughput or propustnost refers to the amount of data that can be transmitted or processed in a given time, influenced by bandwidth, latency, error rates, and network congestion.