The phrase "add a proportion" is correct and usable in written English.
It can be used when discussing the act of including a specific ratio or fraction in a calculation or recipe.
Example: "To achieve the desired flavor, you should add a proportion of salt to the mixture."
Alternatives: "include a ratio" or "incorporate a fraction".
Of the C remaining methane, the model added a proportion to the emissions as carbon dioxide pool to represent oxidation through the landfill cap and the rest was added to the emissions as methane pool.
The alternative model M2a (positive selection) extends the null model M1a by adding a proportion p2 of positively selected sites with ω2>1, estimated from data.
The simpler, "great circle" (Ball et al., 1997) or "small world" (Watts and Strogatz, 1998) approach, just adds a proportion of global contacts.
Model M1a (nearly-neutral) assumes two site classes in proportions p0 and p1 = 1 - p0: one with ω0 ratio estimated between 0 and 1, and the other with ω1 fixed at 1. Alternative model M2a (positive selection) extends the null model M1a by adding a proportion p2 of positively selected sites with ω2 > 1, estimated from data.
While many authors have used the GTR + I + Γ to incorporate rate heterogeneity [ 39], it is well established [ 40] that adding a proportion of invariable sites creates a strong correlation between p0 (parameter of I) and α (parameter of Γ), making it impossible to estimate both parameters reliably [ 41, 42].
Since 2008, the UK has required fuel suppliers to add a growing proportion of sustainable materials into the petrol and diesel they supply.
For the sensitivity analysis to noise, we add a certain proportion (p) of random Gaussian noise to the gene expression data for both transcription factors and their target genes, run causal orientation methods in the noisy data, report their performance, and repeat the entire process to assess variance (again, 100 times for NOTCH1 and RELA and 20 times for YEAST and ECOLI).
The company said that BP had ordered a change in Halliburton's customary formula for cement by adding a higher proportion of a chemical that slows the hardening of the mixture.
Good added: "A significant proportion of these homes will however be off-market as landlords appreciate that these wealthy tenants looking for super-prime homes often like to rent properties that feel private and exclusive".
As shown in Fig. 1, adding a high proportion of wind power creates a problem of energy systems.
