Peak concentrations in the plasma occur in one to two hours following administration.

The greatest concentration of agricultural fields occurs south of the dam.

The highest concentrations of suicide attacks to date occurred in the following time periods:

The greatest concentration of species occurs in the Balkans.

A similar concentration is occurring among video suppliers.

The highest concentrations of such additional radiation occur in or close to the reactors themselves, where my colleagues and I work daily.

The growing concentration of poverty occurs for various reasons.

In certain concentrations may even occur a potentially explosive mixture.

On the DO sag curve a minimum concentration occurs at some point, along a stream.

Declining concentrations of mercury in the fish since 1975 has occurred as the contaminated wastes are naturally buried.