68 research outputs found

    High-Recycling Characteristics in the KSTAR Tokamak Divertor by Using Two-Dimensional Transport Simulations

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    The operation space in the conduction-limited divertor regime of the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak is obtained in terms of the upstream density and the input power through numerical simulations using a two-dimensional two-fluid edge plasma transport code coupled with a two-dimensional Monte Carlo recycling neutral transport code in which the electron impact ionization and the charge exchange of recycling neutrals are taken into account. Two major high-recycling characteristics, the parallel temperature gradient and plasma pressure conservation, are identi ed in this operation space along the magnetic ux tubes between the upstream position and the divertor target plate in the KSTAR tokamak. Inclusion of ion pressures in the present simulations for total plasma pressures shows firm evidence of pressure conservation in the high-recycling regime. In addition, scalings of the plasma temperature and density at the divertor plate with the upstream plasma density are derived, and they are compared with those in a simple one-dimensional analytic transport model, the so-called two-point model. Finally, the simulation shows that the peaked feature of the upstream ion temperature pro le adjacent to the separatrix a ects the distribution of the divertor heat flux. This indicates that the ion parallel heat conduction near the separatrix plays an important role in determining the radial pro le of the heat flux onto the divertor target, as the electron parallel heat conduction does in the conduction-limited regime. It is, therefore, suggested that modification of the upstream plasma property profiles will make it possible to control the power dispersal on the divertor plate

    Three Flavour QCD from the Holographic Principle

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    Building on recent research into five-dimensional holographic models of QCD, we extend this work by including the strange quark with an SU(3)_L\times SU(3)_R gauge symmetry in the five-dimensional theory. In addition we deform the naive AdSAdS metric with a single parameter, thereby breaking the conformal symmetry at low energies. The vector and axial vector sectors are studied in detail and both the masses and decay constants are calculated with the additional parameters. It is shown that with a single extra degree of freedom, exceptional agreement with experimental results can be obtained in the light quark sector while the kaon sector is found to give around 10% agreement with lattice results. We propose some simple extensions to this work to be taken up in future research.Comment: 9 pages, 1 figure, references adde

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

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    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

    Association between red blood cell storage duration and clinical outcome in patients undergoing off-pump coronary artery bypass surgery: a retrospective study

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    Background: Prolonged storage of red blood cells (RBCs) leads to fundamental changes in both the RBCs and the storage media. We retrospectively evaluated the relationship between the RBC age and in-hospital and long-term postoperative outcomes in patients undergoing off-pump coronary artery bypass. Methods: The electronic medical records of 1,072 OPCAB patients were reviewed and information on the transfused RBCs and clinical data were collected. The effects of RBCs age (mean age, oldest age of transfused RBCs, any RBCs older than 14 days) on various in-hospital postoperative complications and long-term major adverse cardiovascular and cerebral events over a mean follow-up of 31 months were investigated. Correlations between RBCs age and duration of intubation, intensive care unit, or hospital stay, and base excess at the first postoperative morning were also analyzed. Results: After adjusting for confounders, there was no relationship between the RBCs age and in-hospital and long-term clinical outcomes except for postoperative wound complications. A significant linear trend was observed between the oldest age quartiles of transfused RBCs and the postoperative wound complications (quartile 1 vs. 2, 3 and 4: OR, 8.92, 12.01 and 13.79, respectively; P for trend = 0.009). The oldest transfused RBCs showed significant relationships with a first postoperative day negative base excess (P = 0.021), postoperative wound complications (P = 0.001), and length of hospital stay (P = 0.008). Conclusions: In patients undergoing off-pump coronary artery bypass, the oldest age of transfused RBCs were associated with a postoperative negative base excess, increased wound complications, and a longer hospital stay, but not with the other in-hospital or long-term outcomes.Peer Reviewe

    Overexpression of a novel cytochrome P450 monooxygenase gene, CYP704B1, from Panax ginseng increase biomass of reproductive tissues in transgenic Arabidopsis

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    Cytochrome P450 monooxygenase 704B (CYP704B), a member of the CYP86 clan, was found to be needed in Arabidopsis and rice to biosynthesize precursors of sporopollenin through oxidizing fatty acids. In the present study, we cloned and characterized a CYP704B gene in Panax ginseng, named PgCYP704B1. It shared high sequence identity (98–99%) with CYP704 of Arabidopsis, Theobroma cacao, and Morus notabilis. The phylogenetic comparison of ginseng and higher plants between the members of CYP86 clan revealed that ginseng CYP704 was categorized as a group of CYP704B with dicot plants. The expression of PgCYP704B1 is low in the stem, leaf, and fruit, and high in fower buds, particularly detected in the young gametic cell and tapetum layer of the developing anther. Arabidopsis plants overexpressing PgCYP704B1 improved plant biomass such as plant height, siliques and seed number and size. A cytological observation by transverse and longitudinal semi-thin sections of the siliques cuticles revealed that the cell length increased. Furthermore a chemical analysis showed that PgCYP704B1ox lines increased their cutin monomers contents in the siliques. Our results suggest that PgCYP704B1 has a conserved role during male reproduction for fatty acid biosynthesis and its overexpression increases cutin monomers in siliques that eventually could be used for seed productio

    Relationship Between the Extent of Chromosomal Losses and the Pattern of CpG Methylation in Gastric Carcinomas

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    The extent of unilateral chromosomal losses and the presence of microsatellite instability (MSI) have been classified into high-risk (high- and baseline-level loss) and low-risk (low-level loss and MSI) stem-line genotypes in gastric carcinomas. A unilateral genome-dosage reduction might stimulate compensation mechanism, which maintains the genomic dosage via CpG hypomethylation. A total of 120 tumor sites from 40 gastric carcinomas were examined by chromosomal loss analysis using 40 microsatellite markers on 8 chromosomes and methylation analysis in the 13 CpG (island/non-island) regions near the 10 genes using the bisulfite-modified DNAs. The high-level-loss tumor (four or more losses) showed a tendency toward unmethylation in the Maspin, CAGE, MAGE-A2 and RABGEF1 genes, and the other microsatellite-genotype (three or fewer losses and MSI) toward methylation in the p16, hMLH1, RASSF1A, and Cyclin D2 genes (p<0.05). The non-island CpGs of the p16 and hMLH1 genes were hypomethylated in the high-level-loss and hypermethylated in the non-high-level-loss sites (p<0.05). Consequently, hypomethylation changes were related to a high-level loss, whereas the hypermethylation changes were accompanied by a baseline-level loss, a low-level loss, or a MSI. This indicates that hypomethylation compensates the chromosomal losses in the process of tumor progression
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