water content

(redirected from Water saturation)
Also found in: Encyclopedia.

water content 

Water in a contact lens expressed as a percentage of the total mass of the lens in its hydrated state under equilibrium conditions with physiological saline solution containing 9 g/l sodium chloride at a temperature of 20 ± 0.5ºC and with a stated pH value.
where M is the mass of hydrated lens, m is the mass of dry lens.The US Food and Drug Administration (FDA) has categorized hydrogel contact lenses into four groups according to their water content and their surface reactivity (referred to as ionic if it contains more than 0.2% ionic material, and nonionic otherwise). Group 1: water content less than 50% and non-ionic. Group 2: water content greater than 50% and non-ionic. Group 3: water content less than 50% and ionic. Group 4: water content greater than 50% and ionic.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
For the relative water content and water saturation deficit, no significant difference (p >0.05) was noted in the treatments (Table 2).
The new taps that contain water saturation mechanisms to reduce the actual flow of water is made of safe material, which does not cause any change in the quality, colour or taste of water for human consumption even if exposed to temperatures up to 90C, according to authorities.
We found significant differences (mound soil and undisturbed soil) in % water saturation, electrical conductivity (E/C), pH, organic matter, phosphorus, potassium and biomass in all types of soil.
The resistivity logs were utilized in order to obtain water saturation ([s.sub.w]).
Evolution of the bond stress during 28 d of storage in different environments with water saturation of the substrate: Mortar with earthenware ceramic waste
Next, its auxiliary equipment, such as a vacuum drying oven (DHG-9023A), vacuum water saturation device (NEL-VJH), and rock centrifuge (TG16-WS), is also used to cause the cores to undergo the "drying-saturation-centrifugation" process for the purpose of obtaining the related [T.sub.2] spectra under the saturation and centrifugation conditions.
It is well accepted that the quasistatic strength of rock decreases with respect to water saturation [9-15].
Water saturation shift referencing (WASSR) images were collected with a CW pulse (0.2 [micro]T/200 ms) which was applied at 31 frequency offsets every ~0.03 ppm.
where [P.sub.cave], [K.sub.ave], and [[phi].sub.ave] are average capillary pressure, permeability, and porosity of plugs under the same water saturation; [sigma] is interfacial tension; [theta] is wetting angle; [S.sub.wn] is normalized water saturation; [S.sub.w] is water saturation; [S.sub.wc] is connate water saturation; [S.sub.or] is irreducible oil saturation.
The enhancement factor f is the ratio of the partial pressure of water in the vapor to the water saturation pressure at that temperature:
The residual oil saturation (Sor) in a mixed-wet rock was lower than the Sor in an oil-wet rock, and the residual water saturation (Srw) in mixed-wet rock was lower than the Srw in a water-wet rock under identical flooding conditions.
The process of weighting is repeated until the constant mass, that is, until samples reach water saturation level [16, 29-32].