The phrase "variable quantities of" is correct and usable in written English.
You can use this phrase when you want to describe something that has a seemingly unpredictable or changing quantity. For example, "We've been harvesting variable quantities of apples each week, depending on the weather."
Variable quantities of functionalised peroxides bearing carboxylic acid groups were reacted with polypropylene in a twin-screw extruder.
The variable quantities of Salvianolic acids and tanshinones composite powder (STW) were optimized using the central composite design-response surface method.
It was reported by others that liver secretes variable quantities of adenosine and that secretion is related to the level of liver hypoxia.
The cooling water pumps (CWP) in power plants generally operate at constant speed, pumping variable quantities of water depending on the tide level in the sea.
These biofilms are typified by variable quantities of extracellular polymeric substances (EPS: predominantly polysaccharides, glycoconjugates, and proteins) and the embedded microbial cells.
In the case of ammonium sulphate, precipitation was optimized by addition of variable quantities of the precipitant agent until enzymatic activity recovered in the supernatant (measured in triolein hydrolysis) was minimal.
An alternative is to supply the reheat by blending with a variable quantity of warmed air, supplied through a second duct system.
It can be obtained that between 20°C and 100°C, the largest variable quantity of the resistivity is just about 0.28 Ω.
According to the definition of Dikau et al. (1996) and Iverson and Denlinger (2001), debris flows consist of a mixture of fine material (sand, silt and clay), coarse material (gravel and boulders), with a variable quantity of water, which flow rapidly with one or more surges, commonly following pre-existing drainage ways.
This contribution describes the effect of SBA-15(16) support modification with variable quantity of P2O5 (0.5 and 1.0 wt%) on the catalytic response of supported ternary CoMoW catalysts tested in the gas-phase hydrogenolysis of anisole, as a model compound for pyrolysis oil.
In general, the cat will turn its back on the area of choice, raise the tail and arch the back, then spray a variable quantity of urine onto a vertical surface, whilst spraying the tail may also quiver [4].
