Nippon Steel Corporation (日本製鉄株式会社, Nippon Seitetsu kabushiki gaisha), was formed in 2012 by the merger of the old Nippon Steel and Sumitomo Metal. The old Nippon Steel Corporation was established in 1970 by the merger of Fuji Iron & Steel and Yawata Iron & Steel. Nippon Steel is the world's third largest steel producer by volume as of 2019.
This study synthesized mold fluxes in the CaO–SiO2–CaF2–MgO–SrO system to clarify how the SrO/CaO ratio affects viscosity and crystallization under static and rotating conditions (11.8 s−1). The primary objective was to identify conditions that favor the formation of fluoride-free primary crystalline phases. The viscosity showed a non-monotonic dependence on the SrO/CaO ratio: it increased up to SrO/CaO = 0.18 and then decreased at higher SrO contents. In situ capacitance measurements further revealed that crystallization during cooling was influenced by shear. In addition, increasing SiO2 and varying SrO/CaO altered the primary phase in some compositions, shifting from cuspidine to akermanite. These changes in viscosity and the primary phase are attributed to Sr2+'s stronger affinity for F− than Ca2+. Depending on composition and temperature, rotation either promoted or suppressed crystallization. Highly viscous melts—especially SrO-free compositions—tended to crystallize less readily, and the magnitude of this effect depended on composition. Overall, the present results provide insight into the structural and kinetic factors governing viscosity and crystallization in fluoride-reduced mold fluxes.
Liquation cracks often occur due to the local melting of segregated parts and constituents with low melting temperatures at the grain boundaries in the heat-affected zone (HAZ) of Alloy 625. Low-energy grain boundaries, called coincidence site lattice (CSL) boundaries, can reduce the intergranular segregation. Therefore, an effective distribution and large ratio of CSL boundaries (grain boundary character distribution, GBCD) can improve the liquation cracking susceptibility. The relationship between GBCD and liquation cracking susceptibility in the HAZ of Alloy 625 was examined by applying grain boundary engineering (GBE). The CSL ratio and E9 + E27 ratio increased with increasing annealing time and reached the maximum ratios after 48 h. Liquation cracking susceptibility was investigated using a hot tensile test with in-situ observations. The liquation crack was initiated in the locally melted part and propagated along the grain boundary. The crack tended to occur at random boundaries and the frequency was higher than those of the E9 E27 boundary. Besides, the E9 E27 boundary often acted as a barrier for the propagation from the random boundary. Thus, an effective distribution and increase of the E9 E27 boundary, which ha higher melting temperature, can reduce the liquation cracking susceptibility.
The hydrogen entry behavior of a partially Zn-coated steel sheet in NaCl solutions was investigated employing a polyaniline-based hydrogenochromic sensor, electrochemical hydrogen permeation tests, and potential measurements using a scanning Kelvin probe. While the Zn coating mitigated corrosion of the steel substrate, it simultaneously accelerated the hydrogen entry. The hydrogen entry occurred at the bare steel surface regions exposed to the NaCl solution, with the hydrogen flux exhibiting non-uniform distribution: higher near the dissolving Zn coating. While no significant differences in Zn dissolution behavior or galvanic current were observed between 0.1 and 0.01 M NaCl solutions, the total hydrogen flux decreased with decreasing Cl- concentration. This reduction was attributed to a potential gradient induced by differences in electrolyte conductivity. The results demonstrate that potential distribution, rather than galvanic current, is a dominant factor influencing hydrogen entry under the investigated conditions.
Background While work-family conflict (WFC) has been reported to exert adverse effects on workers' health conditions, evidence linking WFC to presenteeism and absenteeism is not only limited in number but also geographically biased.Aims To examine the associations of WFC with health-related presenteeism and absenteeism among Japanese workers.Methods This study was conducted as part of the Japan Epidemiology Collaboration on Occupational Health study in which we used questionnaire information collected from 7766 workers from five worksites. Absenteeism was defined when they took at least half a day off in the past month. Presenteeism, defined as self-rated poor work performance, was assessed on a scale ranging from 10% to 100%, with those reporting 10-60% classified as poor performance. WFC was assessed using eight items (0-16 scores) with participants categorized into quartiles based on the WFC score. A logistic regression model was used to estimate odds ratios and 95% confidence intervals for presenteeism and absenteeism in relation to WFC categories.Results Of the total participants, 16% reported absenteeism and 15% reported presenteeism. Compared to the individuals in the first quartile of WFC (Q1), individuals in the Q2, Q3 and Q4 categories had 1.17 (0.95-1.43), 1.65 (1.44-1.89) and 2.65 (2.17-3.24) higher odds of absenteeism. The corresponding figures for presenteeism were 1.04 (0.79-1.38), 1.31 (1.13-1.53) and 2.13 (1.85-2.45), respectively.Conclusions Work-family conflict was significantly associated with absenteeism and presenteeism among Japanese workers, which underscores the need to acknowledge and accommodate the balance between work and family responsibilities for workplace health promotion.
Nonomuraea bangladeshensis B208 has been reported to convert several flavonoids into hydroxylated derivatives. Here, we present a draft genome sequence that reveals the gene sets encoding putative cytochrome P450 monooxygenases associated with the generation of oxygenated flavonoids of medical and nutritional relevance.
