The phrase "a certain period when" is correct and usable in written English.
It can be used to refer to a specific time frame or duration in which something occurs or is relevant.
Example: "There was a certain period when the company experienced rapid growth and expansion."
Alternatives: "a specific time when" or "a particular period during".
Applicants for permanent residence mainly need to exhibit two prerequisites to qualify: time and desire, which generally require that applicants must have resided in their receiving country for a certain period when they apply and are willing to become naturalized (Xiao [2006]).
The private sector should also be given incentives such as tax breaks for a certain period when they employ more young people since high employment rates leads to increased purchasing power that will benefit the very same private sector.
Although nitrogen starvation reduces photosynthetic efficiency [ 9], photosynthesis and carbon assimilation continue for a certain period when the microalgae are exposed to nitrogen depleted conditions [ 10].
Water stress occurs when the demand for water exceeds the available amount during a certain period or when poor quality restricts its use.
The above waveform indicates that voltage drops sharply in a certain period (OA period) when the battery is discharged while the polarization voltage only changes slightly due to the voltage drop caused by the ohmic resistance (R s ).
And there were certain periods when combat without a reprieve was banned altogether.
Nelson believes that universities will end up effectively telling students: "Take the following online courses over the summer or over a certain period, and then, when you're done, you will come to campus and that's when our job will begin".
"There are certain periods when your guard has to be up, and this is one of them for a variety of reasons that are quite solid in their sourcing.
The MediaFLO network, which will be developed and operated by a Qualcomm subsidiary called MediaFLO USA, is based on a push multicasting paradigm in which battery consumption is reduced by downloading video only during certain periods when the phone is not in use.
Generally speaking, I keep it with me when I need to be available during certain periods when I'm on the move.
Data from placebo groups actually answers the question, "what is the expected outcome over a certain period of time when a person (or a group of similar persons) believes they are receiving true treatment, when, in fact, they are not?" In Borghouts et al., 6 trials are reviewed with placebo controls [ 25- 30], but they, too, were not summarized with respect to this question.
