Nondestructive measurement of water content and moisture migration of unsaturated red clays in South China

To reveal the moisture migration mechanism of the unsaturated red clays, which are sensitive to water content change and widely distributed in South China, and then rationally use them as a filling material for highway embankments, a method to measure the water content of red clay cylinders using X-ray computed tomography (CT) was proposed and verified. Then, studies on the moisture migrations in the red clays under the rainfall and ground water level were performed at different degrees of compaction. The results show that the relationship between dry density, water content, and CT value determined from X-ray CT tests can be used to nondestructively measure the water content of red clay cylinders at different migration time, which avoids the error reduced by the sample-to-sample variation. The rainfall, ground water level, and degree of compaction are factors that can significantly affect the moisture migration distance and migration rate. Some techniques, such as lowering groundwater table and increasing degree of compaction of the red clays, can be used to prevent or delay the moisture migration in highway embankments filled with red clays.

Energy security in the news:North/South perspectives

Analysis of newspaper reporting on the topic of energy security in eight countries – four from the global North (France, Germany, the UK, and the United States) and four from the global South (China, India, Brazil, and South Africa) – produces no support for the thesis that news is disseminated from core countries to the periphery and semi-periphery. There is an important difference between China and the other three fast-developing countries and a highly asymmetric flow of news not aligned to old core-periphery boundaries. In general, energy security is mainly covered in trade and business outlets and less in newspapers with mass circulation, indicating that the topic is still an elite concern. In some instances, attention has surged at the same time in different countries. But very few of these instances show a homogenous coverage across countries. Despite increasingly globalised media, news is created and consumed at a national level.