The phrase "a quantity which is" is correct and usable in written English.
It can be used when defining or describing a specific amount or measurement in a context such as mathematics, science, or statistics.
Example: "In this experiment, we will measure a quantity which is essential for determining the reaction rate."
Alternatives: "an amount that is" or "a measure that is".
In each case, the standard apparent rate constant, k0, was demonstrated to be a quantity which is inaccessible to measurement by electrochemical means.
In addition, the method offers the possibility to derive average water levels for a reach segment, a quantity which is essential in flood forecasting and flood risk assessment.
For purposes of this subsection, a person who obtains a product made by a process patented in the United States in a quantity which is abnormally large in relation to the volume of business of such person or an efficient inventory level shall be rebuttably presumed to have actual knowledge that the product was made by such patented process.
A relationship based on dimensional analysis is used to interrelate the discharges at two different stages by simply using the geometrical parameters such the cross-sectional area, wetted perimeter, the width of the free surface and a quantity which is related to the summations of isovel contours.
Unfortunately the slope of the interaction is a quantity which is not easy to determine.
Ion transport number is a quantity which is indicative of the different contributions of ions to the electric current in electrolytes due to their varied electrical mobility.
For each condition, we characterized these dynamics by their apex, [IL-2]max, a quantity which was proportional to the T cell population's total [IL-2] accumulation over time.
A conserved quantity is any quantity which is universally conserved, and current scientific theory is our best guide as to what these are.
A phasor is a vector quantity which is used to represent a sinusoidal signal regarding its magnitude and phase angle.
A topological index is a numerical quantity which is uniquely determined for a graph and invariant under graph isomorphism.
Application of the usual variational procedure for the quantity of interest (such as the buckling load, fundamental frequency, or deflection) results in a dimensionless quantity which is a function only of the undetermined exponent.
