OPEC siege members of OPEC were taken hostage in Vienna, Austria, where the ministers were attending a meeting at the OPEC headquarters at Dr-Karl-Lueger-Ring 10 (renamed Universitätsring in 2012). The hostage attack was orchestrated by a six-person team led by Venezuelan terrorist Carlos the Jackal (which included Gabriele Kröcher-Tiedemann, Hans-Joachim Klein and Anis al-Naqqash). The self-named "Arm of the Arab Revolution" group called for the liberation of Palestine. Carlos planned to take over the conference by force and kidnap all eleven oil ministers in attendance and hold them for ransom, with the exception of Ahmed Zaki Yamani and Iran's Jamshid Amuzegar, who
Damp (structural) water is absorbed into the porous material and is transported above the water line. Rising damp can be identified by a characteristic "tide mark" on the lower section of affected walls. This tide mark is caused by soluble salts (particularly nitrates and chlorides) contained in the groundwater. Due to the effects of evaporation these salts accumulate at the "peak" of the rising damp. The issue of rising damp has been a concern since ancient times. The Roman Architect Vitruvius referred to the problem of dampness rising up walls and advised on how to construct buildings to avoid the problem. Rising