This study aims to investigate the strength of coke at high temperature in reaction atmosphere. A uniaxial compression test measured the fracture stress of coke at three conditions: (i) room temperature and air atmosphere; (ii) 1100°C and N₂ atmosphere; (iii) 1100°C and CO₂ atmosphere. The drum index (DI) and coke strength after reaction (CSR) were also measured. The DI and CSR of coke produced by a lump of caking coal were higher than those of coke produced by non- or slightly caking coal. The compression tests showed that the fractured stress at room temperature in the air atmosphere was lower than that at 1100°C in the N₂ atmosphere. Also, the fractured stress at 1100°C in the N₂ atmosphere was higher than that at 1100°C due to the CO₂ reaction. The DI, CSR, and hot coke strength of coke produced by caking coal was higher than those of coke produced by non- or slightly caking coal.

The hot strength of coke prepared from an acid-washed lignite by briquetting-carbonization before and after CO₂ gasification was, for the first time, investigated in this work. The hot strength at 1000°C before gasification was higher than coke strength measured at a room temperature. CO₂ gasification resulted in a linear decrease of the hot strength with the reaction time. The lignite-coke showed faster decrease in the strength during gasification, compared to conventional cokes derived from caking coal or non-or slightly caking coal, due to the high reactivity caused by its porous structure and catalytic metal species remaining even after the acid-washing, while it showed superior hot strength at the initial stage of gasification.

The strength, pore structure, and material constants of coke prepared from caking coal (Coke A) and non- or slightly caking coal (Coke C) were experimentally and numerically investigated with a particular focus on those values at high temperatures. Coke A showed higher strength and lower porosity than Coke C. The pore structure imaged by X-ray computed tomography was translated to the finite element mesh with the image-based modeling, and the stress analysis based on the finite element method was performed to calculate the mode value of maximum principal stress at different Young’s modulus and Poisson’s ratio. Young’s modulus of Coke A and Coke C at a constant Poisson’s ratio decreased and increased, respectively by heating. When the temperature increased, the compression stress of Coke A increased. The result indicated that the coke strength could be increased by heating because of the decrease in apparent Young’s modulus, accompanied by the occurrence of creep.

The oxygen isotope ratio (δ¹⁸O) of tree-ring cellulose provides a valuable climatic record with an annual timescale. In Japan, the cellulose δ¹⁸O records have been accumulated over the past decade. However, no long-term records have been reported for the southern subtropical island, Okinawa-jima, where many long-lived trees were burned during the Second World War and have been periodically damaged by typhoons. Here, we show a cellulose δ¹⁸O of Ryukyu Pine (Pinus luchuensis Mayr.) from the Okinawa-jima island. This δ¹⁸O data, which was obtained from a tree-disk preserved in a University Museum, cover a 95-year period before meteorological observation began on this island in 1891. The cellulose δ¹⁸O variations negatively correlate with the amount of precipitation during the rainy season, suggesting that the cellulose δ¹⁸O values are largely affected by δ¹⁸O of rainwater rather than large scale ENSO variations.

The incidence of male reproductive system disorders, especially hypospadias, has been increasing in developed countries since the latter half of the 20th century. Endocrine-disrupting chemicals from the environment are considered to be involved in hypospadias onset through epigenetic alterations. This pilot study aimed to explore disease-specific methylated CpGs in human patient samples using the methylated-site display-amplified fragment length polymorphism (MSD-AFLP) technique developed by our research group [1]. We compared clinical samples from hypospadias and phimosis patients. Foreskin and blood samples were collected from one- to two-year-old patients with hypospadias (N = 3) and phimosis (N = 3) during surgical treatment. MSD-AFLP analysis showed significantly decreased CpG-methylation levels of genes such as MYH11 and increased CpG-methylation levels of genes such as PLA2G15 in hypospadias patients. Hierarchical clustering analysis showed that genes with significantly altered CpG levels were more markedly altered in DNA from blood than from foreskin. Because of the small number of samples, further investigation is necessary to elucidate the association between variations in CpG levels in foreskin and blood DNA and male genital abnormalities. However, our MSD-AFLP method appears to be a useful tool for exploring disease-specific methylated-CpGs in human epidemiological studies.

Thermal easy axis and thermal diffusivity of uniaxial carbon fiber-reinforced plastic sheets were determined by an offset periodic laser heating method, and investigated relationship between the thermal easy axis and fiber orientation with different thickness of CFRP sheet specimen, experimentally. It was clarified that the orientation of the thermal easy axis spreads in the in-plane direction with the sheet thickness deceases. Then, thermal diffusivity of CFRP specimens in the out-of-plane and in-plane direction were measured by two methods: a variable-frequency method and a variable displacement method, respectively. In the results of the out-of-plane directions, thermal diffusivity almost consistent with the carbon fiber direction were obtained. In contrast, the in-plane directions of those were exhibited unexpected value. Moreover, thermal diffusivity determination by offset periodic heating method was carried out. Finally, it is found that the thermal diffusivity considering the thermal easy axis with fiber angle was different characteristics from the in-plane direction measurement. These results are to be useful for development of a novel thermal interface materials with heat transfer controllable.