The phrase "also observed that certain" is correct and usable in written English.
It can be used when discussing findings or conclusions drawn from observations in research or analysis.
Example: "The researchers also observed that certain variables had a significant impact on the results."
Alternatives: "also noted that specific" or "also found that particular".
It was also observed that certain chemical additives increased RAP binder mobilisation and blending efficiency to comparable levels of that in hot mix asphalt (HMA) mixtures.
We have also observed that certain dpolv mutations will complement other dumpy lethal alleles, particularly other dplv and dpol mutations.
We also observed that certain parameters of the survivors progressively improved especially during the second week of the disease.
We also observed that certain known virulence factors were upregulated during Sz35246 infection, for example, streptokinase (SeseC_02411) and fibronectin-binding protein (sfs, SeseC_00464).
Although the majority of activated genes were similar between the two species, we also observed that certain metabolic pathways were specifically activated, especially those related to signaling pathways and detoxification mechanisms.
We have also observed that certain processes related to immunity are overexpressed in the sensitive as well as in resistant cell lines, but we found that ontological categories for these processes have significantly better p-values in the resistant ones.
But Helbing also observed that at certain critical densities, such as occur in a crowd crush, all forms of collective behavior vanish.
It is also observed that under certain conditions a smooth transition from a diffusion driven flame to a shock ignition detonation is possible.
It was also observed that in certain parts of the throughput region CSMA displays short-term unfairness[4]: Namely, theoretically computed throughputs emerge as time averages only if such averages are computed over long-time intervals.
Nsentip (1987) also observed that in certain parts of the coast, and in particular the open sea off the Niger Delta, E. fimbriata is caught all-year round whenever the canoes venture to sea.
We also observed that at certain inlet conditions, high amplitude velocity and heat release fluctuations coexist even without pressure-heat release coupling, meaning that the Rayleigh criterion is not necessarily associated with the onset of the self-excited instability.
