"passive background" is a correct and usable phrase in written English.
You can use it to refer to a situation in which something is happening without requiring any deliberate effort or action on the part of anyone involved. For example, "The passive background of the natural environment created a serene atmosphere."
We got experience on these activities by conceiving and optimizing the active and passive background rejection system of the Simbol-X and IXO/HXI missions.
It is shown that the main features of EIS on localized corrosion systems arise from the frequency dependence of the ac current distribution between corrosion sites and surrounding passive background.
For beams of mono-energetic particles interacting with a passive background, but not with each other, in two space dimensions, the first author proposed such a solver, based on angular domain decomposition, some time ago.
The results of the analyses show that the socio-physical characteristics of the neighbourhoods studied are not a passive background of the social phenomenon, but are variables that intervenes directly in.
Even their more subdued releases are dense with meaning and movement they trade almost exclusively in the sort of records that make passive background listening impossible.
The conceptual difficulties basically follow from the nature of the gravitational interaction, in particular the equivalence of gravitational and inertial mass, which allows one to represent gravity as a property of spacetime itself, rather than as a field propagating in a (passive) spacetime background.
Here's what's actually unrealistic: fiction in which more than half of the population of Earth simply isn't present, or is only present in the background, as passive entities.
It is first responder news; it is a real time news index; and, for more and more news consumers, it is background or passive news, like local radio once was, but on an international scale.
Ventilation at the first point of active exercise was the same when started either from rest or from a background of passive leg movement (p = 1.00).
Ongoing work in our laboratory is focused on reducing silicone background for passive sampling devices through additional solvent precleaning prior to deployment, and through surrogate correction experiments.
Each 25 μl PCR reaction mix also included 1 × TaqMan universal PCR master mix with AmpliTaq Gold DNA polymerase, uracil- N-glycosylase (AmpErase), dNTPs with dUTP, and a passive reference to minimize background fluorescence fluctuations.
