"in a certain ratio" is grammatically correct and can be used in written English.
It means that something is in a specific proportion or relationship to something else. Example: The recipe calls for the ingredients to be mixed in a certain ratio to achieve the perfect balance of flavors.
And DJ Andrew Weatherall was such an ACR nut that for a while in the 1980s he donned the band's trademark "desert rats" style – although he admitted to the Guardian recently that a "Hitler Youth haircut, German army vest and big shorts" meant that while "I thought I looked like I was in A Certain Ratio, actually I looked like Don Estelle in It Ain't Half Hot Mum".
Due to developments in the advanced 3D textile composite materials, it has become possible to tailor their mechanical properties by either placing the reinforcing fibers in a particular direction or mixing the fibers of superior mechanical properties with fibers of nominal mechanical properties in a certain ratio.
The study was carried out using a configuration by which butane was fed to the inner tube (tube-side) where the catalyst was mounted and O2 was fed either entirely to the outer tube (shell-side) or distributed in a certain ratio between the tube- and shell-sides with a variation of the pressure difference across the membrane, ΔP.
(3) Mix different sands according to experiment demand, and add clay to the sand in a certain ratio, then pour the white oil, mixed sand and clay into the oil-sand blending tank in a certain ratio.
In the water systems, two nitrogen forms coexist in a certain ratio depending on the water pH, temperature, and ionic strength unionized NH3 (ammonia) and ionized NH4 + (ammonium).
But to spot the colder hydrogen, which emits no easily detectable signal, researchers must measure radio waves emitted by carbon monoxide and assume that the two molecules are found together in a certain ratio.
As a result, we succeed in reducing a certain ratio of modified Fredholm perturbation determinants associated with operators in L2(Ω dnx), n∈N, to modified Fredholm determinants associated with operators in L2(∂Ω dn−1σ), n⩾2.
In contrast, a certain ratio (19.0 at.%) of the graphitic nitrogen atom is produced, which obviously displays that the heat-treatment process at 700 °C causes the rapid decomposition of the nitrile and pyrrolic nitrogen atoms owing to their instability [25].
(A little known fact: Connell was part of the Manchester music scene that birthed Joy Division/New Order; he played in the band A Certain Ratio. Check out this 2011 video of Swing Out Sister performing New Order's "Perfect Kiss").
The model predictions reproduce the maximum in activity observed in the HDS of thiophene for a certain ratio of Co/Mo in the catalyst.
Tony Wilson: The last conversation we had, which was at the Birmingham gig [2 May 1980], which was the last gig ever, was about how interested I was in his and [A Certain Ratio frontman] Simon Topping's use of archaic language.
