Experimental study on the physico-mechanical properties of Tamusu mudstone — A potential host rock for high-level radioactive waste in Inner Mongolia of China

Tamusu mudstone, located in Bayin Gobi Basin in Inner Mongolia of China, has been selected as a potential host rock for high-level radioactive waste(HLW) disposal in China. A series of tests has been carried out, including X-ray diffraction(XRD) tests, scanning electron microscopy(SEM) tests, disintegration tests, permeability tests and triaxial compression tests, to estimate the physico-mechanical properties of Tamusu mudstone in this work. The mineral composition of Tamusu mudstone was analyzed and it was considered as a stable rock due to its low disintegration rate, i.e. approximately 0.11%after several wet/dry cycles. Based on the results of permeability test, it was found that Tamusu mudstone has a low permeability, with the magnitude of about 10—20m^(2). The low permeability makes the mudstone well prevent nuclide migration and diffusion, and might be influenced by temperature.The triaxial tests show that Tamusu mudstone is a stiff mudstone with high compressive strength, which means that the excavation disturbed zone would be smaller compared to other types of mudstone due to construction and operation of HLW repositories. Finally, the properties of Tamusu mudstone were compared with those of Opalinus clay, Callovo-Oxfordian(COx) argillite, and Boom clay to further discuss the possibility of using Tamusu mudstone as a potential nuclear waste disposal medium.

Study on Wave-influenced resistance to erosion of silty soil in Huanghe (Yellow) River Delta

Along with the reduction of sediment yield of the Huanghe （Yellow） River, the erosion of the Huanghe River Delta aggravates, which has becomes an important factor that threatens the coastal protection structures. Starting from the study of the erosion resistibility of the sediment, this paper explores the internal mechanism of erosion phenomenon. This paper takes Diaokou as the study area and takes soils as samples which are mixed with clay into reconstructed samples whose ratio of clay content are 5%, 10%, 15%, 20% respectively, then dynamic tri-axial apparatus is applied to simulate wave loads of different intensity; then the resistibility of soil to erosion is determined via concentrated flow test and the structural property is determined via the disintegration test. Finally, the resistibility to erosion and the structural property of the non-compressed soil samples are compared with the compressed data. The results indicates that liquefaction failure exerts significant influence on the resistibility to erosion and the structural property of the silty soil in the Huanghe River Delta. Therefore, in the future erosion studies, the liquefaction phenomenon shall be fully considered.

Quality Evaluation of Carnitine for Proper Use of Supplement

In recent years, consumers are becoming more health-conscious. Supplements are becoming popular as they can be purchased easily. In Japan, the “Food with Function Claims” system began in 2015;the market for supplements is expected to continue to expand. However, the use of some supplements has not been supported with sufficient scientific evidence;some products have even caused health problems. In addition, consumers may not be able to make correct decisions based on the information from the Internet. Unlike medicine, the instruction on the usage of supplements is not precise. Therefore, improving the quality of the information on the supplements will become more necessary in the future. This study aims to improve the quality of the information on supplements by surveying the disintegration and dissolution behavior of the carnitine-containing supplements and evaluated their quality. The products tested here were supplements containing commercial carnitine. Disintegration test and dissolution test were conducted according to the Japanese Pharmacopoeia. Carnitine was quantified by high-performance liquid chromatography. The disintegration tests revealed that the products had different disintegration times, varying from 35 to 100 minutes;some products took more than 5 hours to disintegrate. Thus, some products had a slow rise in their dissolution rate. These results suggest that the carnitine-containing supplements used in this study may affect the absorption process. Therefore, in the case of oral administration, the expected effect might not be achieved depending on the product.