(gÉrÄ­l`É) [Span.,=little war], fighting by groups of irregular troops (guerrillas) within areas occupied by the enemy. When guerrillas obey the laws of conventional warfare they are entitled, if captured, to be treated as ordinary prisoners of war; however, they are often executed by their captors.
The Inside Story â Concrete Is Porous. Most people do not realize that concrete is porous â more porous than Swiss cheese! The pores constitute 12 â 18% or more of the concrete but they are invisible, much smaller than the diameter of human hair. After new concrete is poured, almost half of the water has to evaporate.
All stone, even granite, is porous to some degree, and will absorb stains over time. Some stones are more porous than others, so it is important to use a penetrating sealer to prevent stains from oil, wine, or other liquids from soaking into the surface.ike marble, polished limestone is subject to surface changes or damage from kitchen acids including citrus juices, vinegars, mustards, and so forth. Unsealed, some of the more porous limestones can be subject to stains.