Átfolyása

Átfolyása is a Hungarian term describing the act or process by which something flows through another substance, medium, or barrier. It derives from át- meaning through or across and folyás meaning flow. In technical usage it is often translated into English as throughflow or permeation, depending on context.

In hydrology and soil science, átfolyása describes the portion of water that moves through a soil layer or rock formation, either laterally within the subsurface or vertically from the surface to groundwater. This throughflow affects drainage, base flow in rivers, and groundwater recharge. Key controlling factors include hydraulic conductivity, porosity, moisture content, soil structure, slope, and groundwater gradients. Throughflow can be rapid in coarse materials and slower in clays, and it may be influenced by macropores and preferential pathways.

In engineering and environmental engineering, átfolyása can refer to the flow of liquids through pipes, membranes, filters, or porous media. It matters for the design of drainage systems, filtration units, chemical reactors, and containment barriers. In the context of contaminant transport, throughflow is part of advection processes that move dissolved substances through soils and sediments; modelling often uses Darcy's law and related transport equations.

In biological and medical contexts, the term may describe the passage of liquids through tissues, membranes, or channels, for example in pharmacokinetics when a drug’s throughflow across a barrier is of interest. The term is common in Hungarian technical literature; its precise meaning is context-dependent, and translators choose throughflow, permeation, or related terms accordingly.