Siserõhulises

Siserõhulises is a term used to describe a state, process, or characteristic in which a system's mechanical behavior is dominated by internal pressure rather than external pressure. The word derives from the Estonian siserõhk meaning “internal pressure,” with the suffix -lises indicating a state or quality.

In scientific usage, siserõhulises refers to materials or structures where internal gas or fluid pressure exerts a significant influence on deformation, stability, and transport properties. It is often contrasted with regimes where external pressure predominates. Key considerations include stress distribution according to Laplace’s law, the distinction between thin-shell and thick-shell responses, and the balance between internal pressure and wall strength that determines critical radius, buckling, and rupture thresholds.

Applications appear in areas such as drug delivery (liposomes and polymeric capsules), food science (gas-expanded foams), and microfluidics (gas- or air-filled droplets). The concept serves in theoretical models to predict swelling, fracture, and permeability under internal-pressure constraints, as well as in design discussions for pressurized devices and vesicular systems.

Limitations: the term remains specialized and not universally standardized; it is more commonly found in Estonian-language literature or theoretical discussions than in broad, cross-disciplinary usage. Ongoing clarification and cross-language adoption could help unify its scope and nomenclature.

See also: Internal pressure, Laplace’s law, Osmotic pressure, Wall stress, Capsule (drug delivery), Liposome.