Preservation of York Minster historic limestone by hydrophobic surface coatings

Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO 2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from 'breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO/H O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation.

Highly emotional States:French-US Relations and the Iraq war

Understanding the true nature of the relations between France and the United States is central to an understanding of the diplomatic crisis that broke out between them in 2003 over the War in Iraq. An analysis of the political cultures of France and the US offers considerable explanatory power to this dramatic diplomatic dispute. The inordinately emotional aspects of the Franco-US arguments of 2003 mask the fact that the two countries understand each other little. In the French case, its self-view and related diplomatic comportment in the twentieth century was informed by its relationship to Germany; and from it a range of cultural characteristics emerged, among them: vulnerability, self-regard, a romanticized view of itself, and the personalization of national identity. At the moment France’s response to its cultural heritage was beginning to shift to a different (post-Gaullist) paradigm, the dispute with the US erupted.