Prediction of phase separation in multi-component oxide glass for the fabrication of porous glass materials from waste slag

Published under licence in Journal of Physics: Conference Series by IOP Publishing Ltd

Sakurajima-Satsuma (Sz-S) and Noike-Yumugi (N-Ym) tephras: new tephrochronological marker beds for the last deglaciation, southern Kyushu, Japan

Two prominent tephras, Sakurajima-Satsuma (Sz-S) erupted from Sakurajima volcano and Noike-Yumugi (N-Ym) erupted from Kuchierabujima Island, provide new key marker beds for dating and synchronizing palaeoenvironmental and archaeological records in the last deglaciation in southern Japan. These tephras were identified on the basis of glass major-element compositions in two distal areas, a marine core (IMAGES MD98-2195) in the northern part of the East China Sea and on the central part of Tanegashima Island, and related their stratigraphic positions to the marine oxygen isotope-based chronology. In MD98-2195, Sz-S, 0.8 cm in thickness at 9.12 m depth and N-Ym, 3 cm in thickness at 9.30 m depth, are both white, vitric, ash-grade tephras. On Tanegashima Island, Sz-S, 10 cm in thickness and N-Ym, 3 cm in thickness, are stratigraphically constrained by well-characterised marker tephras Kikai-Akahoya (7,300 cal BP) and Aira-Tn (29,000 cal BP). Sz-S is rhyolitic and homogeneous on the basis of glass major-element compositions assayed by electron microprobe. Pumiceous glass shards predominant in distal Sz-S tephra indicate that it derived from pumice fall units that correspond to pumiceous and phreatomagmatic fine ash units constituting proximal Sz-S tephra. N-Ym is rhyolitic and glass major-element analyses reveal compositional diversity between units, suggesting that the lower and middle tephra units dispersed to the east, whereas the upper unit was dispersed north to north-west from the vent. Stratigraphically, Sz-S occurs at around the start of the late-glacial reversal (cooling) in oxygen isotope records of MD98-2195, corresponding to the end of GI-1 and the start of GS-1 in the ice-core events of NGRIP (GICC05), consistent with a terrestrial age of ˜12,800 cal BP. Based on the oxygen isotope stratigraphy, the tephra identified in the core as N-Ym at 9.30 m depth is close to the end of Greenland GI-1 and hence has an age of ˜13,000 cal BP, but on Kuchierabujima Island it has an age based on ¹⁴C assay of charcoal of c. 14,900 cal BP. Although this age discrepancy (14.9 vs 13.0 cal ka) needs resolution, the occurrence in core MD98-2195 of N-Ym shows that it is more widespread than hitherto demonstrated. The widespread distributions and key stratigraphic positions for the two marker tephras indicate that they are thus critical isochrons for precise correlation of palaeoenvironmental changes and prehistoric cultural events during the last deglaciation in southern Kyushu, and for relating such changes and events to the ice-core chronology via the marine oxygen isotope chronostratigraphy

Surface ionic coordination of Al₂O₃–CaO–based molten slag induced by structural relaxation

Suzuki M., Asano Y., Ishii Y.. Surface ionic coordination of Al₂O₃–CaO–based molten slag induced by structural relaxation. Journal of the American Ceramic Society , (2024); https://doi.org/10.1111/jace.19818.The surface tensions of molten oxides depend strongly on the structural relaxation of the surface region. The mechanism of surface structural relaxation for molten oxide slags is complex. The surface tension of calcium aluminate slag is minimal at an intermediate composition, although the critical reason has not been identified. Here, two novel approaches were used to evaluate the features of surface ionic structures in the molten state for the range of 25–50 mol% Al₂O₃: (1) X-ray absorption analysis of oxygen and cationic elements in glass samples after surface relaxation treatment, and (2) molecular dynamics simulations, based on a polarizable-ion model, of the ionic distribution in a molten slag with vacuum/melt interfaces. The results indicate that bridging oxygen (BO) ions are preferred to non-BOs in the surface region. In calcium aluminate slag, BOs are formed by connecting two AlO₄ tetrahedrons with charge compensation of two Al³⁺ ions with one Ca²⁺ ion. Additionally, the above approaches were used to qualify the effect on the surface ionic structure of adding 1–20 mol% SiO₂ to the calcium aluminate slag. The results indicated that the SiO₄ tetrahedrons incorporate the vertex connection with AlO₄ tetrahedrons to form BOs in the surface region

Association between Total Antioxidant Capacity in Breast Milk and Postnatal Age in Days in Premature Infants

This study aimed to consider the significance of breast milk in preventing oxidative stress by comparing total antioxidant capacity (TAC) in breast milk and formula milk for premature infants, demonstrating the relationship between TAC in breast milk and postnatal age in days. We used the biological anti-oxidant potential test, a new method to measure TAC in breast milk. Breast milk for premature infants were stored at −20°C and thawed within 48 h of collection. We measured TAC in two types of formula milk in the same way. TAC was clearly higher in breast milk than formula milk. Although a negative correlation was observed between TAC in breast milk and age when collected, TAC was always higher than the average TAC in formula milk. TAC in breast milk is higher than TAC in formula milk. We suggest the importance of breast milk for preventing oxidative stress and starting breastfeeding early

Assessing future potentiality of technologies from the perspective of “imaginary future generations” – A case study of hydrothermal technology

Hara K., Miura I., Suzuki M., et al. Assessing future potentiality of technologies from the perspective of “imaginary future generations” – A case study of hydrothermal technology. Technological Forecasting and Social Change 202, 123289 (2024); https://doi.org/10.1016/j.techfore.2024.123289.To guide technological innovation for sustainability, it is essential to develop a methodology for assessing the future potentiality of a technology from a long-term perspective. In this study, we propose an innovative method for assessing the future potentiality of technology from the perspective of imaginary future generations (IFGs) using a case study of hydrothermal technology and verify the effectiveness of the method. We conducted participatory deliberation experiments adopting the method and studied its effect on the formulation of scenarios for the adoption of hydrothermal technology in society in the year 2040, and on the assessment of the future potentiality and innovation of technology. Using deliberation experiments and questionnaires administered to the participants, we confirmed that IFGs had a significant effect on the adoption of technology in future scenarios and on the assessment results, with concomitant shifts in the relative weights of assessment indicators. We also found that the adoption of IFGs could lead to relativizing the value and positioning of a technology, and to shifting the requirements for the development and adoption of a technology. The results provide insights into the methodology to assess future potentiality of technologies and guide technology innovation from the viewpoint of futurability

Genome-wide investigation of in vivo EGR-1 binding sites in monocytic differentiation

A Genome-wide analysis of EGR-1 binding sites reveals co-localization with CpG islands and histone H3 lysine 9 binding. SP-1 binding occupancies near EGR-1 binding sites are dramatically altered