HIGH-TEMPERATURE STRUCTURAL ANALYSIS ON A SMALL-SCALE PHE PROTOTYPE CONSIDERING MECHANICAL PROPERTIES IN THE HEAT-AFFECTED ZONE AND IN THE WELD ZONE

ABSTRACT PHE (Process Heat Exchanger) is a key component in transferring the high temperature heat generated from a VHTR (Very High Temperature Reactor) to the chemical reaction for massive production of hydrogen. A performance test on a small-scale PHE prototype made of Hastelloy-X is currently undergoing in a small-scale gas loop at the Korea Atomic Energy Research Institute. Previous researches on the high-temperature structural analysis of the small-scale PHE prototype had been performed using parent material properties over the whole region. In this study, high-temperature elastic structural analysis considering mechanical properties in the weld zone was performed and the analysis result was compared with previous researches

Creep and Oxidation Behaviors of Alloy 617 in Air and Helium Environments at 1173K

AbstractCreep and oxidation behaviours of Alloy 617 in air and helium (He) environments at 1173K were comparatively investigated under different applied stress levels. There were no large differences in the shapes of the creep curves between the air and He environments. Creep rupture time in the He environment was shorter than that in air. The outer Cr-oxide thickness of the air specimens was thicker in short-tested duration than that of the He specimens. However, in the long- tested duration over 3,000h, the Cr-oxide thickness in the He environment was larger than in air. It was found that creep rupture life was closely related to the thickness of the outer Cr-oxide layer, because the form of the outer Cr-rich oxide layer brings about the Cr-depleted region which may deteriorate material strength or creep life

Src Is a Prime Target Inhibited by Celtis choseniana

Celtis choseniana is the traditional plant used at Korea as a herbal medicine to ameliorate inflammatory responses. Although Celtis choseniana has been traditionally used as a herbal medicine at Korea, no systemic research has been conducted on its anti-inflammatory activity. Therefore, the present study explored an anti-inflammatory effect and its underlying molecular mechanism using Celtis choseniana methanol extract (Cc-ME) in macrophage-mediated inflammatory responses. In vitro anti-inflammatory activity of Cc-ME was evaluated using RAW264.7 cells and peritoneal macrophages stimulated by lipopolysaccharide (LPS), pam3CSK4 (Pam3), or poly(I:C). In vivo anti-inflammatory activity of Cc-ME was investigated using acute inflammatory disease mouse models, such as LPS-induced peritonitis and HCl/EtOH-induced gastritis. The molecular mechanism of Cc-ME-mediated anti-inflammatory activity was examined by Western blot analysis and immunoprecipitation using whole cell and nuclear fraction prepared from the LPS-stimulated RAW264.7 cells and HEK293 cells. Cc-ME inhibited NO production and mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), and tumor necrosis factor-alpha (TNF-α) in the RAW264.7 cells and peritoneal macrophages induced by LPS, pam3, or poly(I:C) without cytotoxicity. High-performance liquid chromatography (HPLC) analysis showed that Cc-ME contained anti-inflammatory flavonoids quercetin, luteolin, and kaempferol. Among those, the content of luteolin, which showed an inhibitory effect on NO production, was highest. Cc-ME suppressed the NF-κB signaling pathway by targeting Src and interrupting molecular interactions between Src and p85, its downstream kinase. Moreover, Cc-ME ameliorated the morphological finding of peritonitis and gastritis in the mouse disease models. Therefore, these results suggest that Cc-ME exerted in vitro and in vivo anti-inflammatory activity in LPS-stimulated macrophages and mouse models of acute inflammatory diseases. This anti-inflammatory activity of Cc-ME was dominantly mediated by targeting Src in NF-κB signaling pathway during macrophage-mediated inflammatory responses

The effects of rice seed dressing with Paenibacillus yonginensis and silicon on crop development on South Korea’s reclaimed tidal land

A field trial to investigate the effects of plant growth promoting bacteria (PGPB) Paenibacillus yonginensis (DCY84T) and/or SiO2 seed coating on rice growth (Oryza sativa L.) was carried out on reclaimed tidal land in Taean County in South Korea. The field test was performed twice between May–October 2014 and May–October 2015, in a randomized complete block (RCB) design with three replications. Treatments consisted of: Mock, DCY84T-treated seeds, SiO2-coated seeds and DCY84T-SiO2-treated seeds and each treatment area covered approximately 300 m2. During the early developmental period of rice seedlings, the SiO2 coating without DCY84T led to the most favorable 30 DAS rice seedling parameters. Moreover, the combination of DCY84T and SiO2 treatments resulted in 2-fold greater fresh and dry weights of 60 DAS rice seedlings compared to Mock seedlings. DCY84T and SiO2, both individually and together, produced a greater grain yield and a greater total yield; specifically, DCY84T and SiO2 treatments yielded a 73% and 70% increase in mass compared to Mock plants, respectively. Rice treated with both DCY84T and SiO2 treatment contained the highest amount of Al, Fe, Ca and Mg, which were 54%, 169%, 42% and 67% higher than the Mock rice, respectively. Remarkably, DCY84T treatment had the most phosphate [P], potassium [K] and total nitrogen [T–N]. DCY84T and/or SiO2 treatment highly increased the whole kernel percentage. Thus, lower its broken kernel percentage to 9.60–24.58%. The protein content of the grain with both treatments was 7.2%, which was greater than that of the Mock grain (6.0%). The content of chlorophyll a, b and carotinoid in the rice leaves which were treated with silica and DCY84 has increased more than the mock without treatment. After harvest, the GABA content of brown rice was increased to 1.9-fold (2014), 1.5 fold (2015) compared to mock grain, respectively. Overall, DCY84T treatment and SiO2 coating can be useful methods for promoting growth of rice under conditions of saline stress. Results from other laboratory trials and greenhouse experiments are also provided

Anticancer Efficacy of Cordyceps militaris

Cordyceps militaris is used widely as a traditional medicine in East Asia. Although a few studies have attempted to elucidate the anticancer activities of C. militaris, the precise mechanism of C. militaris therapeutic effects is not fully understood. We examined the anticancer activities of C. militaris ethanolic extract (Cm-EE) and its cellular and molecular mechanisms. For this purpose, a xenograft mouse model bearing murine T cell lymphoma (RMA) cell-derived cancers was established to investigate in vivo anticancer mechanisms. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, immunoblotting analysis, and flow cytometric assay were employed to check in vitro cytotoxicity, molecular targets, and proapoptotic action of Cm-EE. Interestingly, cancer sizes and mass were reduced in a C. militaris-administered group. Levels of the phosphorylated forms of p85 and AKT were clearly decreased in the group administered with Cm-EE. This result indicated that levels of phosphoglycogen synthase kinase 3β (p-GSK3β) and cleaved caspase-3 were increased with orally administered Cm-EE. In addition, Cm-EE directly inhibited the viability of cultured RMA cells and C6 glioma cells. The number of proapoptotic cells was significantly increased in a Cm-EE treated group compared with a control group. Our results suggested that C. militaris might be able to inhibit cancer growth through regulation of p85/AKT-dependent or GSK3β-related caspase-3-dependent apoptosis

Anti-Inflammatory Effect of Piper attenuatum

Piper attenuatum is used as a traditional medicinal plant in India. One of the substances in P. attenuatum has been suggested to have anti-inflammatory effects. However, there is insufficient research about the anti-inflammatory mechanisms of action of P. attenuatum. The effects of P. attenuatum methanol extract (Pa-ME) on the production of inflammatory mediators nitric oxide (NO) and prostaglandin E2 (PGE2), the expression of proinflammatory genes, the translocation level of transcription factors, and intracellular signaling activities were investigated using macrophages. Pa-ME suppressed the production of NO and PGE2 in lipopolysaccharide- (LPS-), pam3CSK4-, and poly(I:C)-stimulated RAW264.7 cells without displaying cytotoxicity. The mRNA expression levels of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2) were decreased by Pa-ME. P-ME reduced the translocation of p50/NF-κB and AP-1 (c-Jun and c-Fos), as well as the activity of their upstream enzymes Src, Syk, and TAK1. Immunoprecipitation analysis showed failure of binding between their substrates, phospho- (p-) p85 and p-MKK3/6. p-p85 and p-MKK3/6, which were induced by overexpression of Src, Syk, and TAK1, were also reduced by Pa-ME. Therefore, these results suggest that Pa-ME exerts its anti-inflammatory effects by targeting Src and Syk in the NF-κB signaling pathway and TAK1 in the AP-1 signaling pathway