• Journal of the Korean institute of surface engineering
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• v.39 no.4
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• pp.179-189
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• 2006

High velocity oxygen fuel(HVOF) thermal spray coating of WC-Co powder is one of the most promising candidate for the replacement of the traditional hard chrome plating and ceramics coating because of the environmental problem of the very toxic $Cr^{6+}$ known as carcinogen and the brittleness of ceramics coating. WC-Co micron and nano powder were coated by HVOF thermal spraying method for the study of durability improvement of the high speed spindle. Coatings were planned by Taguchi program for the four spray parameters of spray distance, flow rates of hydrogen, oxygen and powder feed rate. Optimal coating process was obtained by the studies of coating properties such as porosity, surface roughness, micro hardness, and micro structure. WC-Co micron and nano powder were coated on the Inconel 718 substrate by the optimal coating process obtained in this study. The wear behaviors were studied by the sliding wear tester at room temperature and at an elevated temperature of $500^{\circ}C$ for the application to high speed spindle. Sliding wear test was carried out for four most promising hard coatings of chrome coating, ceramics coatings such as $A1_2O_3,\;Cr_2O_3$ and HVOF Co-alloy T800 for the comparison of their wear behaviors. HVOF WC-Co coating was better than other coatings showing highest micro hardness of 1400 Hv and comparable friction coefficients with others. HVOF WC-Co coating is a strong candidate for the replacement of the traditional hard chrome plating for the high speed spindle.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.161-166
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• 1984

The Cheju citrus orchards have been chemically fertilized with both phosphates high in Ca and Mg contents and potassium. The amount of chemical fertilizers consumed per unit area of cultivated land and the ratios of $P_2O_5$ and $K_2O$ to N in chemical fertilizers applied were much higher in the Cheju Island than those of the Korean mainland. These trends were particularly prominant in Southern Cheju where 70% of the Cheju citrus orchards are located. As the result of heavy applications of phosphate fertilizers, the available phosphorus of citrus orchard soils increased with increasing number of years under cultivation. The available phosphorus of sub-soil increased slightly with the number of years under cultivation compared to that of surface soil. Base saturation and pH increased with the number of years under cultivation, inasmuch as exchangeable bases such as Ca, Mg and K increased predominantly, but the cation exchange capacity did not vary in the citrus orchard soils.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.3
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• pp.27-27
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• 1987

The purpose of this study is to find the light intensity which induced maximum gathering rate and to observe the variation of the gathering rate both at daytime and night by using Sea-bass, Epinephelus septemfasciatus (Thunberg). An experimental tank (360 L×50 W×55H cm) was set up in a dark room. An illumination system was attached to the end of one side of the tank to control horizontal light intensity. Eight artificial light sources were prepared by combination of three with white light bulbs (10W, 60W, 100W) and eight filters. During the experiment water depth was maintained 50cm level in the tank. The tank was marked into six longitudinal sections each being 60cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 50 minutes before the main experiment. Upon turning on the light, the number of fish in each section was counted 60 times every 30 seconds, and the gathering rate was obtained from the average number of fish in each section. The light intensity inducing maximum gathering rate was 24.13 lux (15.25~35.93 lux) at daytime and 0.41 lux (0.25~0.63 lux) at night. The variation of the gathering rate of fish in illumination time was great and did not show any definite pattern but fluctuated irregularly. Its different between daytime and night is remarkable.

• FLOWER RESEARCH JOURNAL
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• v.18 no.2
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• pp.98-109
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• 2010

78 Korean native plants, which have not been used in general, were selected to be used as outdoor pot plants for three seasons, from spring to autumn. Plants, which were explored in about 30 places of Korea from 2007 to 2009, were transplanted to or sown in white plastic general pots ($27.5cm({\Phi}){\times}27.5cm(H)$) and hanging pots($28cm({\Phi}){\times}13cm(H)$) and grown in the garden of 36''56' latitude(N) and 127''09' longitude(E). 38 species(13 families and 29 genus) were suitable for outdoor general pots, and 46 species(28 families and 43 genus) for outdoor hanging pots. Among 38 plants for outdoor general pots, the principal species, which were easy to grow and have not been used in general, were 16 species, Metaplexis japonica in Asclepiadaceae, Phyteuma japonicum in Campanulaceae, Artemisia capillaris, Artemisia princeps, and Artemisia selengensis in Compositae, Carex humilis in Cyperaceae, Pennisetum alopecuroides, and Setaria viridis in Gramineae, Agastache rugosa, Glechoma hederacea, Elsholtzia splendens, Isodon inflexus, and Mosla punctulata in Labiatae, Vicia villosa in Leguminosae, Piper kadzura in Piperaceae, and Rosa multiflora var. multiflora in Rosaceae. Among 46 plants for outdoor hanging pots, the principal species, which were easy to grow and have not been used in general, were 17 species, Metaplexis japonica in Asclepiadaceae, Ixeris stonlonifera in Compositae, Calystegia japonica and Quamoclit angulata in Convolvulaceae, Dioscorea batatas in Dioscoreaceae, Glechoma hederacea and Thymus quinquecostatus in Labiatae, Trifolium lupinaster for. alpinus and Vicia villosa in Leguminosae, Menispermum dauricum in Menispermaceae, Piper kadzura in Piperaceae, Clematis mandshurica for. lancifolia in Ranunculoideae, Rosa multiflora var. multiflora and Potentilla fragarioides var. major in Rosaceae, Paederia scandens and Rubia akane in Rubiaceae, and Parthenocissus tricuspidata in Vitaceae.

• Journal of Environmental Science International
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• v.28 no.6
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• pp.527-533
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• 2019

The aim of present study was to investigate the effect of three types of Chestnut Meals (CM) on chemical composition and rumen fermentation characteristics of the fermented diet. The inoculants consisted of Lactobacillus acidophilus, Bacillus subtilis, and Sacaromyces cerevisiae and were applied to three different types of CM; Whole Chestnut (WC), endodermis (EN), and kernel (KE). All types of CMs were ensiled at $39^{\circ}C$ for 0, 1, 2, 4, or 6 days. After ensiling, the fermented CMs were sub-sampled for laboratory assays. On day six of fermentation, counts of the lactic acid-producing Bacillus subtilis, and yeast were higher (P<0.05) in WC than in the other CM types. On day four, KE had higher (P<0.05) crude protein content but lower (P<0.05) neutral detergent fiber and acid detergent fiber contents than the other treatments. In terms of rumen digestibility, KE had the highest (P<0.05) in vitro digestibility of dry matter (IVDMD), neutral detergent fiber digestibility (IVNDFD), total volatile fatty acid (VFA), propionate, butyrate concentrations, and total gas volume, as well as the lowest (P<0.05) acetate concentration. On the other hand, EN had the highest (P<0.05) pH and ammonia-N concentration in the rumen. In the rumen, even though WC application produced the highest microbial count and fermentation characteristics, it did not have a beneficial effect on rumen digestibility. Therefore, this study concluded that application of KE could be recommended due to the observed improvements in IVDMD and IVNDFD.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.97-105
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• 2023

Background: Hyperactivated airway mucosa cells overproduce mucin and cause severe breathing complications. Here, we aimed to identify the effects of saponins derived from Panax ginseng on inflammation and mucin overproduction. Methods: NCI-H292 cells were pre-incubated with 16 saponins derived from P. ginseng, and mucin overproduction was induced by treatment with phorbol 12-myristate 13-acetate (PMA). Mucin protein MUC5AC was quantified by enzyme-linked immunosorbent assay, and mRNA levels were analyzed using quantitative polymerase chain reaction (qPCR). Moreover, we performed a transcriptome analysis of PMA-treated NCI-H292 cells in the absence or presence of Rg5, and differential gene expression was confirmed using qPCR. Phosphorylation levels of signaling molecules, and the abundance of lipid droplets, were measured by western blotting, flow cytometry, and confocal microscopy. Results: Ginsenoside Rg5 effectively reduced MUC5AC secretion and decreased MUC5AC mRNA levels. A systematic functional network analysis revealed that Rg5 upregulated cholesterol and glycerolipid metabolism, resulting in the production of lipid droplets to clear reactive oxygen species (ROS), and modulated the mitogen-activated protein kinase and nuclear factor (NF)-kB signaling pathways to regulate inflammatory responses. Rg5 induced the accumulation of lipid droplets and decreased cellular ROS levels, and N-acetyl-ⳑ-cysteine, a ROS inhibitor, reduced MUC5AC secretion via Rg5. Furthermore, Rg5 hampered the phosphorylation of extracellular signal-regulated kinase and p38 proteins, affecting the NF-kB signaling pathway and pro-inflammatory responses. Conclusion: Rg5 alleviated inflammatory responses by reducing mucin secretion and promoting lipid droplet-mediated ROS clearance. Therefore, Rg5 may have potential as a therapeutic agent to alleviate respiratory disorders caused by hyperactivation of mucosa cells.

• Korean Journal of Organic Agriculture
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• v.32 no.3
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• pp.277-288
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• 2024

The present study was conducted to investigate the effects of seaweeds on in vitro ruminal fermentation characteristics and methane gas production. Five seaweeds (Dictyota dichotoma, DD; Chrysymenia wrightii Yamada, CW; Codium fragile, CF; Sargassum fusiforme, SF; Gracilaria vermiculophylla, GV) were obtained from National Institute of Fisheries Science (NIFS) in South Korea. The ruminal fluids were collected from 3 rumen-cannulated Hanwoo steers (average 12-months-old). The buffered ruminal fluids (50 mL) were incubated with substrates (0.4 g of concentrate and 0.1 g of rice straw in dry matter basis) and seaweeds (5% of substrates) at 39℃ for 24 and 48 hours. The total gas and methane production of all treatments incubated for 24 hours were not affected by the seaweed. However, methane production (mL/g of digested dry matter) in the CW and CF treatments incubated for 48 hours was decreased compared to control (p<0.05). Additionally, the ruminal pH of all treatments incubated for 24 and 48 hours was lower than control (p<0.05). There was no signigicant difference in total VFA concentration at 24 hours of incubation, but it was higher in the CF treatment at 48 hours of incubation (p<0.05). The dry matter digestibility of all treatments incubated for 24 and 48 hours were not affected by the seaweed. In conclusion, Codium fragile reduced in vitro methane production without negative effects on rumen fermentation characteristics.

• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.313-321
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• 1999

The purpose of these study was to investigate the use of a glass micropipette (GMP) as a vessel for vitrification of bovine IVP blastocysts, to compare the post-thaw survival rates of bovine blastocysts frozen in GMP with those frozen in OPS that have been previously investigated, and to improve the hatching rate following vitrification with GMP method. The GMP vessel permits higher freezing and warming rate than the OPS due to the higher heat conductivity of the glass and lower mass of the solution that contains the embryos. Groups of three bovine IVP blastocysts were sequentially placed into vitrification solution before being loaded into either the OPS or GMP vessels and immersed into L$N_2$within 20 to 25 sec. Post-thaw blastocysts were serially washed in 0.25 and 0.15 M sucrose in HM and TCM-199 for each 5 min, respectively, and then cultured in TCM 199 supplemented with 10% FCS for 24 h. The rate of blastocyst re-expanding did not significantly different for OPS (75.9%) and GMP (80.0%) methods (P＞0.05). The hatching rates in OPS (34.1%) and GMP (37.5%) methods were significantly lower than that in control group (54.3%) (P＞0.05). In addition, the rate of blastocyst re-expanding was significantly lower if blastocysts were vitrified in the wide portion of the micropipette rather than the narrow portion of the micropipette (83.3 vs 56.7%) (P＞0.05), even though three blastocysts were loaded per vessel. The hatching rate in 0.05% pronase solution treatment for 30, 60 and 90 see (45.9, 54.7 and 57.5%) were significantly higher than that in control (35.0%), even though there was not significantly different between 30 see and control. These results indicate that both vitrification vessels can provide high survival rates of bovine IVP blastocysts. However, the GMP vessel has the advantage over the OPS, in that the former does not need a cap to protect the vessel from floating after immersion in L$N_2$. The location of the embryos (narrow or wide portion of immersion) were considered to be limiting factors to the viability of bovine IVP embryos. The exposing in 0.05% pronase solution for 60 or 90 see can increase hatching rates of post-thaw bovine IVP blastocysts.

• Applied Biological Chemistry
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• v.49 no.2
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• pp.91-96
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• 2006

Antioxidant activities and biological properties such as antimutagenic and cytotoxic effect of Phellinus linteus extracts from different extraction conditions were measured against Salmonella typhimurium and human cancer cell lines. DPPH free radical scavenging activities of the extracts were higher in the solutions extracted with ethanol (17.14) and ethanol after water (17.79), respectively. In the Ames test, ethanol extract of P. linteus alone did not exhibit any mutagenicity but showed substantial inhibitory effect against mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide (4NQO), and benzo $({\alpha})$ pyrene $(B({\alpha})P)$. The extracts of ethanol and ethanol after water of P. linteus $(200\;{\mu}g/plate)$ had the highest inhibitory effect of 61.5 and 60.9%, respectively, on the mutagenesis on S. typhimurium TA98 strain induced by $B({\alpha})P$. Extracted solutions of ethanol and ethanol after water of P. linteus showed high antimutagenic effect against MNNG, 4NQO, Trp-P-1 and $B({\alpha})P$, causing mutations in S. typhimurium TA100 strain. The anticancer effects of P. linteus extracts were investigated against human fibrosarcoma HT-29 and human hepatocellular carcinoma HepG2. The treatment of 0.5 mg/ml of ethanol, ethanol after water and water extracts of P. linteus had the highest cytotoxicity of 59, 57, 54%, respectively against HT-27 cell line, whereas low cytotoxicity effects were observed against HepG2 cell line in the range of $10{\sim}30%$. The ethanol and water extracts of P. linteus also showed the nitrate scavenging ability at different pHs. The ethanol extract showed higher nitrate-scavenging ability compared to water extract of P. linteus.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.239-240
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• 2008

As semiconductor devices are scaled down for better performance and more functionality, the Cu-based interconnects suffer from the increase of the resistivity of the Cu wires. The resistivity increase, which is attributed to the electron scattering from grain boundaries and interfaces, needs to be addressed in order to further scale down semiconductor devices [1]. The increase in the resistivity of the interconnect can be alleviated by increasing the grain size of electroplating (EP)-Cu or by modifying the Cu surface [1]. Another possible solution is to maximize the portion of the EP-Cu volume in the vias or damascene structures with the conformal diffusion barrier and seed layer by optimizing their deposition processes during Cu interconnect fabrication, which are currently ionized physical vapor deposition (IPVD)-based Ta/TaN bilayer and IPVD-Cu, respectively. The use of in-situ etching, during IPVD of the barrier or the seed layer, has been effective in enlarging the trench volume where the Cu is filled, resulting in improved reliability and performance of the Cu-based interconnect. However, the application of IPVD technology is expected to be limited eventually because of poor sidewall step coverage and the narrow top part of the damascene structures. Recently, Ru has been suggested as a diffusion barrier that is compatible with the direct plating of Cu [2-3]. A single-layer diffusion barrier for the direct plating of Cu is desirable to optimize the resistance of the Cu interconnects because it eliminates the Cu-seed layer. However, previous studies have shown that the Ru by itself is not a suitable diffusion barrier for Cu metallization [4-6]. Thus, the diffusion barrier performance of the Ru film should be improved in order for it to be successfully incorporated as a seed layer/barrier layer for the direct plating of Cu. The improvement of its barrier performance, by modifying the Ru microstructure from columnar to amorphous (by incorporating the N into Ru during PVD), has been previously reported [7]. Another approach for improving the barrier performance of the Ru film is to use Ru as a just seed layer and combine it with superior materials to function as a diffusion barrier against the Cu. A RulTaN bilayer prepared by PVD has recently been suggested as a seed layer/diffusion barrier for Cu. This bilayer was stable between the Cu and Si after annealing at $700^{\circ}C$ for I min [8]. Although these reports dealt with the possible applications of Ru for Cu metallization, cases where the Ru film was prepared by atomic layer deposition (ALD) have not been identified. These are important because of ALD's excellent conformality. In this study, a bilayer diffusion barrier of Ru/TaCN prepared by ALD was investigated. As the addition of the third element into the transition metal nitride disrupts the crystal lattice and leads to the formation of a stable ternary amorphous material, as indicated by Nicolet [9], ALD-TaCN is expected to improve the diffusion barrier performance of the ALD-Ru against Cu. Ru was deposited by a sequential supply of bis(ethylcyclopentadienyl)ruthenium [Ru$(EtCp)_2$] and $NH_3$plasma and TaCN by a sequential supply of $(NEt_2)_3Ta=Nbu^t$ (tert-butylimido-trisdiethylamido-tantalum, TBTDET) and $H_2$ plasma. Sheet resistance measurements, X-ray diffractometry (XRD), and Auger electron spectroscopy (AES) analysis showed that the bilayer diffusion barriers of ALD-Ru (12 nm)/ALD-TaCN (2 nm) and ALD-Ru (4nm)/ALD-TaCN (2 nm) prevented the Cu diffusion up to annealing temperatures of 600 and $550^{\circ}C$ for 30 min, respectively. This is found to be due to the excellent diffusion barrier performance of the ALD-TaCN film against the Cu, due to it having an amorphous structure. A 5-nm-thick ALD-TaCN film was even stable up to annealing at $650^{\circ}C$ between Cu and Si. Transmission electron microscopy (TEM) investigation combined with energy dispersive spectroscopy (EDS) analysis revealed that the ALD-Ru/ALD-TaCN diffusion barrier failed by the Cu diffusion through the bilayer into the Si substrate. This is due to the ALD-TaCN interlayer preventing the interfacial reaction between the Ru and Si.