Dunkirk: Where History Happened. We visit 10 places connected with the remarkable evacuation of the British Expeditionary Force from northern France in 1940. This feature was first published in the April 2010 edition of BBC History Magazine. Tuesday 25th May 2010.
The seepage velocity is less than the actual flow rate of the liquid or gas in the pores because the fluid moves only through the portion of the cross-sectional area S that is occupied by the pores.
The idea is to use DykemÂ® machinist's layout fluid in place of the Sharpie marker on the surface of the optical component. Dykem is a very thin paint or dye that machinists brush onto metal parts to allow them to draw on the metal with any sharp scribing tool. They scribe the layout of cutting and drilling locations (& etc.) directly onto a metal part before machining.