The phrase "a relatively large quantity" is correct and usable in written English.
It can be used when discussing amounts or volumes that are significant in comparison to other quantities, but not excessively large.
Example: "The experiment required a relatively large quantity of water to ensure accurate results."
Alternatives: "a considerable amount" or "a significant quantity".
The appearance of a relatively large quantity of uranium on the black market in Georgia underscored American concerns that such trafficking has shifted from Europe to the Caucasus, Central Asia and Turkey.
The appearance of a relatively large quantity of uranium, nearly four pounds, on the black market in Georgia, a former Soviet republic, has underscored concerns within the American government that trafficking in nuclear material has shifted from Europe to the Caucasus, Central Asia and Turkey.
In the United States, planned coal plants that had not broken ground by mid-2007 were mostly sidetracked, but existing plants are going strong, including some that use older technology that requires a relatively large quantity of coal per kilowatt-hour produced — and releases a proportionately larger quantity of carbon dioxide.
If you were to graph the number of stars that voluntary reviewers assign to things, you'd get a relatively large quantity of five-star reviews, from the people who love whatever they are writing about; a low number of fours, threes, or twos; and mostly ones, from the foaming-at-the-mouth furious.
If soot originates from ions such as C3H3+, the addition of a relatively large quantity of easily ionized cesium removes C3H3+ ions from the flame.
Moreover in VC and WVC, owing to the smaller size of the pile and a relatively large quantity of water added, the leaching of those ions might have been even more pronounced than the PC.
Similar to lysine and arginine, TEOS hydrolysis in [BMIM][BF4] by using relatively large quantity of cationic amino acid histidine (10 mM – 1∶10 TEOS to histidine ratio) resulted in a control over silica morphology, however leads to a completely different set of unique silica structures that contained a mixture of silica microglobules of 20 50 µm diameter and silica plates (Figure 4a b).
Consistent with the hierarchy model, isolation of CSCs has mainly been performed with well-differentiated HCC cell lines, which are thought to include relatively large quantity of CSCs compared to cell lines derived from advanced HCC [ 17, 19– 22].
NO is usually present in cells to at least 100-fold excess, but the relatively large quantity of superoxide dismutase present in cytoplasm (SOD1) or mitochondria (SOD2) of cells appears to ensure that hydrogen peroxide is a major product under normal physiological conditions.
All these approaches however require many enzymatic and purification steps and as a consequence, relatively large quantities of starting poly-A mRNAs are needed which, once again, are difficult to obtain from environmental samples where eukaryotic mRNAs are diluted among predominant bacterial RNAs.
Multistage flash distillation is a thermal process for desalting relatively large quantities of seawater.
