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Gaining a thorough understanding of electrochemical interfaces is critical for the development of next-generation energy storage/conversion devices with high energy density and long-life operation. Direct observation of structural changes provides invaluable information about charge transfer, ionic diffusion, and side reactions in electrochemical reaction processes. Neutron reflectometry is a powerful technique for gaining a nanoscopic understanding at solid/liquid interfaces as a function of the depth[22]. Neutrons are capable of prove electrochemical interfaces owing to the strong penetrating power through the substrate. In addition, lithium can be sensitively detected by neutron; because the scattering length of lithium is significant in comparison with other elements in the electrode for neutron, whereas it is small and almost invisible for X-ray. The depth profile of the neutron scattering length density (SLD) obtained by analyzing the reflectivity profile can reveal the distribution of diffusing ions at the interface. Previous studies on the electrode/electrolyte interfaces by neutron reflectometry have mainly focused on the electrode-side interface (surface structural changes and/or surface electrolyte interphases) [1]. There are no reports of neutron reflectometry being used for discussing the depth distribution at the liquid-electrolyte side. In this study, we analyzed the concentration gradient of ionic species from the layered rocksalt type cathodeto the organic electrolyte by in situneutron reflectometry. Epitaxial Lix M yOz(M= Mn, Co, Ni) film model electrodes with (104) and (001) orientations were fabricated on Nb:SrTiO3single crystals by pulsed laser deposition. In situ neutron reflectometry measurements were conducted on a time-of-flight reflectometer (J-PARC, BL16 SOFIA) with a Li counter electrode and deuterated carbonate-base electrolyte containing LiPF6 [2]. The neutron reflectometry analyses demonstrate that the lithium concentrations in the interfacejust after the cell-construction (prior to electrochemical cycling) which may be related to formation of electrical double layer. The interfacial structures changed with the cell voltages during the electrochemical cycling. We will discuss on the crucial structure-parameters which determine the stability and the reaction rate in the interfacial regions. The depth-profile of the lithium ion distribution could give insight into research directions for electrode materials with highly-functional interfaces. References [1] M. Hirayama, et al.,Electrochemistry 2010, 78, 413; J. E. Owejan, et al., Chem. Mater. 2012, 24, 2133; J. F. Browning, et al., ACS Appl. Mater. Interfaces 2014,6, 18569; H. Kawaura, et al., ACS Appl. Mater. Interfaces 2016, 8, 9540. [2] M. Yonemura, et al., J. Phys.: Conf. Ser., 2014, 502, 012054; M. Hirayama, et al., J. Mater. Res., 2016, 31, 3142. [3] A. Yano, et al., J. Electrochem. Soc., 2018, 165, A3221.

To evaluate the influence of minor and impurity elements on the solidification cracking susceptibility in austenitic stainless steel welds, the transverse Varestraint test was conducted using several extra high purity type 310 stainless steels with different amounts of C, Mn, P and S. The characteristic influence on solidification cracking could be expressed by the ratio of P/S/C≈1∶1·3∶0·56, while Mn affected solidification cracking to a negligible extent. A theoretical approach revealed that the reduced solidification cracking susceptibility with decreasing C, P and S contents could be attributed to the suppression of solidification segregation.

An intergranular corrosion is a main degradation mechanism of austenitic stainless steels for use in a nuclear fuel reprocessing plant. The intergranular corrosion is caused by the segregation of impurities to grain boundaries and the resultant formation of active sites. Extra High Purity (EHP) austenitic stainless steel was developed with conducting the new multiple refined melting in order to suppress the total harmful impurities less than 100ppm. The intergranular corrosion behavior of EHP austenitic stainless steels added various impurities was examined in boiling HNO3 solution with highly oxidizing ions to find a correlation between the intergranular corrosion and the impurities of EHP-SSs. The corrosion rate of EHP austenitic stainless steels supported with the degree of intergranular corrosion relatively well. The relationships between the corrosion rate and the impurities content for EHP-SSs was determined using a multiple regression analysis. The influence on corrosion rate became small in order of B, P, Si, C, S and Mn. There is little effect of Mn on corrosion rate of EHP-SSs in case of 10000appm or less. It was important to control B and P in intergranular corrosion behavior of EHP-SSs

Recent progress in the refining technology has enabled the production of highly pure commercial stainless steels. The hot cracking behaviour of these stainless steels was investigated with respect to type 310 stainless steel. For comparison, four types of 310 stainless steels with various amounts of minor and impurity elements such as C, P and S were used. The purity of type 310 stainless steels used was enhanced in the order of type 310

Austenitic stainless steels suffer intergranular attack in boiling nitric acid with oxidants. The intergranular corrosion is mainly caused by the segregation of impurities at the grain. An extra high purity austenitic stainless steel (EHP alloys) was developed with conducting the new multiple refined melting technique in order to suppress the total harmful impurities less than 100ppm. The corrosion behavior of type 310 EHP alloy with respect to nitric acid solution with highly oxidizing ions (boiling 8kmol/m3 HNO3 solutions containing 1kg/m3 Cr(VI) ions) was investigated. The straining, aging and recrystallizing (SAR) treated type 310 EHP alloy showed superior corrosion resistance for intergranular attack than solution annealed (ST) type 310 EHP alloy with same impurity level. Boron segregation at the grain boundary was detected in only ST specimen using a Fission Track Etching method. It is believed that the segregated boron along the grain boundaries in type 310 EHP alloy was one of main factor of intergranular corrosion. The SAR treatment was effective to restrain the intergranular corrosion for type 310 EHP alloy with B less than 7ppm.

An overdose of acetaminophen (APAP) causes liver injury both in experimental animals and humans. N-acetylcysteine (NAC) is clinically used as an antidote for APAP intoxication, and it is thought to act by providing cysteine as a precursor of glutathione, which traps a reactive metabolite of APAP. Other hepatoprotective mechanisms of NAC have also been suggested. Here, we examined the effects of thiol compounds with different abilities to restore hepatic glutathione, on hepatotoxicity of APAP and furosemide in mice. Overnight-fasted male CD-1 mice were given APAP or furosemide intraperitoneally. NAC, cysteine, glutathione, or glutathione-monoethyl ester was administered concomitantly with APAP or furosemide. All thiol compounds used in this study effectively protected mice against APAP-induced liver injury. Only glutathione-monoethyl ester completely prevented APAP-induced early hepatic glutathione depletion. Cysteine also significantly restored hepatic glutathione levels. NAC partially restored glutathione levels. Exogenous glutathione had no effect on hepatic glutathione loss. NAC and glutathione highly stimulated the hepatic expression of cytokines, particularly interleukin-6, which might be involved in the alleviation of APAP hepatotoxicity. Furosemide-induced liver injury, which does not accompany hepatic glutathione depletion, was also attenuated by NAC and exogenous glutathione, supporting their protective mechanisms other than replenishment of glutathione. In conclusion, exogenous thiols could alleviate drug-induced liver injury. NAC and glutathione might exert their effects, at least partially, via mechanisms that are independent of increasing hepatic glutathione, but probably act through cytokine-mediated and anti-inflammatory mechanisms.

Gender is a factor that influences susceptibility of individuals to drug-induced liver injury in experimental animals and humans. In this study, we investigated the mechanisms underlying resistance of female mice to acetaminophen (APAP)-induced hepatotoxicity. Overnight-fasted male and female CD-1 mice were administered APAP intraperitoneally. A minor increase in serum alanine aminotransferase levels was observed in female mice after APAP administration at a dose that causes severe hepatotoxicity in males. Hepatic glutathione (GSH) depleted rapidly in the both genders prior to development of hepatotoxicity, whereas its recovery was more rapid in female than in male mice. This was consistent with higher induction of hepatic glutamate-cysteine ligase (GCL) in females. Pretreatment of mice with L-buthionine sulfoximine (BSO), an inhibitor of GCL, exaggerated APAP hepatotoxicity only in female mice, resulting in much higher hepatotoxicity in female than in male mice. In addition, hepatic GSH was markedly depleted in BSO-pretreated female mice compared with male mice, which supports severe hepatotoxicity in BSO-pretreated females. APAP treatment highly induced multidrug resistance-associated protein 4 (Mrp4) only in female mice. The resulting high Mrp4 expression could thus contribute to decreased hepatic GSH levels via sinusoidal efflux when GCL is inhibited. In conclusion, resistance to APAP hepatotoxicity in female mice and its reversal by pretreatment with BSO could be attributed to sex differences in disposition of hepatic GSH, which may generally determine susceptibility to drug-induced liver injury.

The hot cracking behaviour of extra high-purity stainless steels was investigated with respect to type 310 stainless steel with various amounts of minor and impurity elements such as C, P, S and Mn. The purity of the type 310 stainless steels used was enhanced in the order of Type 310

The austenitic stainless steels so-called, the EHP steels with the extra high purity, are developed for improving the reliability of nuclear equipments materials used in the heavily corrosive irradiation environments. By considering the impurities segregation mechanism, the major impurities included in the EHP steels is controlled less than 100ppm by the new melting technology. It is two-step refining process composed of CCIM and EB for effectively removing both non-volatile and volatile harmful elements. The risk to cracking on melting and welding processes is also effectively minimized by enhancing both the eutectic point and the metallic bonding at grain-boundaries. In the EHP steels, it is possible to select the appropriate composition of Ni and Cr for stabilizing austenitic phase and enhancing corrosion resistance. The characteristics of the welding joints are as good as those of the base metal because the same filler metal is sed without the formation of residual delta ferrite. The resistance to IGC and SCC of the EHP steels is markedly improved by minimizing the refining effects, except for type 316 steels with Mo. The welding technique and the chemical composition range are selected for standardizing the EHP.

Austenitic stainless steels suffer intergranular attack in boiling nitric acid with oxidants. The intergranular corrosion is mainly caused by the segregation of impurities to grain. An extra high purity austenitic stainless steel (EHP alloys) was developed with conducting the new multiple refined melting technique in order to suppress the total harmful impurities less than 100ppm. The basically corrosion behavior of type 310 EHP alloy with respect to nitric acid solution with highly oxidizing ions was investigated. The straining, aging and recrystallizing (SAR) treated type 310 EHP alloy showed superior corrosion resistance for intergranular attack. The segregated boron along the grain boundaries was one of main factor of intergranular corrosion from fission track etching results. The SAR treatment was effective to restrain the intergranular attack for type 310 EHP alloy with B less than 7ppm.Copyright © 2008 by ASME