Moisture Moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in various commercial products. Moisture also refers to the amount of water vapour present in the air. Control of moisture in products can be a vital part of the process of the product. There is a substantial amount of moisture in what seems to be dry matter. Ranging in products from cornflake cereals to washing powders, moisture can play an important role in the final quality of the product. There
Tissue-to-air ratio Tissue-to-air ratio Tissue-to-air ratio (TAR) is a term used in radiotherapy treatment planning to help calculate absorbed dose to water in conditions other than those directly measured. The TAR at a point in a water phantom irradiated by a photon beam is taken to be the ratio of the total absorbed dose at that point to the absorbed dose at the same point in a minimal-scatter phantom with just-sufficient build-up. Tissue-air ratio is defined as the ratio of the dose to water at a given depth to the dose in air measured with a buildup cap: formula_1 where D(f,z) is