• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2626-2630
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• 2009

2'($\beta$)-Hydroxymethylated adenosine is a potent and selective inhibitor of hepatitis C virus (HCV) replication. It targets the RNA-dependent RNA polymerase of HCV, NS5B. Synthesis and antiviral evaluation of carbocyclic versions are described. The cyclopentene intermediate ($9\beta$) was successfully synthesized through sequential Johnson-Claisen orthoester rearrangement and ring-closing metathesis (RCM). Coupling of bases via a Pd(0) catalyst, selective dihydroxylation, and desilylation yielded the target nucleoside analogues. The compounds 17 and 18 were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line and showed moderate antiviral activity with toxicity up to 20.0 and 24.7 ${\mu}g/mL$, respectively.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.25-28
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• 2013

This study presents both experimental and numerical investigation of ignition characteristics of n-heptane and n-butanol mixture. The $O_2$ concentration was fixed to 9-10% to make high exhaust gas recirculation(EGR) rate condition. Experiments were performed using a rapid compression machine. In addition, a numerical study of the ignition delay time was performed using CHEMKIN codes to validate experimental results and predict chemical species after combustion process. The results showed that the ignition delay time increased with increasing n-butanol ratio and the reactivity decreased by low $O_2$ concentration.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.1
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• pp.40-45
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• 1983

The paper describes an experimental investigation of axisymmetric diesel spray and flame which is held in rapid compression machine (RCM) with electromagnetic single injection nozzle. The axisymmetric diesel spray and flame are taken with high speed photograph and analysis it with image processor. The data presented include fuel concentration of spray, flame temperature, soot concentration of flame in axial and radial direction at a moment and compared it with each other.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.775-784
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• 2021

After isolating the DIMO 52 strain with a large inhibition zone diameter for Clostridium perfringens and maximum butyric acid production from the fecal sample of a breastfeeding infant, it was identified as Clostidium butyricum. The maximum growth of the DIMO 52 strain was reached 24 h after inoculation, and the maximum butyric acid concentration was approximately 34.73±4.27 mM. The DIMO 52 strain survived approximately 67.5% of the initial inoculum at pH 2.0, and approximately 64.9% survived in RCM broth supplemented with 0.3% (w/v) oxgall. In addition, DIMO 52 showed antibacterial activity against Escherichia coli KCTC 2441 and Salmonella Typhimurium KCTC 1925. In LPS-stimulated RAW264.7 cells, 1×10³ CFU/mL viable cells of the DIMO 52 strain also exhibited significant NO (nitric oxide) production inhibitory activity (33%, p<0.01). This result suggests that C. butyricum DIMO 52 has anti-inflammatory activity related to NO radical-scavenging activity. In conclusion, C. butyricum DIMO 52 isolated in this study has the potential to be used as a probiotic.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.247-250
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• 2008

The paper presents the advanced radiometric calibration method, called the lRCM (Iterative Radiometric Calibration Method), in order to avoid an operational constraint (solar source) for calibration. The IRCM assumes that an optical instrument is equipped with a filter assembly which consists of same band filters with different transmission ratios. Given all the noise sources (including the artificial one caused by the filters) of an image sensor, the noncentral ${\chi}^2$ distribution of the output result is induced by the approach of a noise PDF (Power Density Function). Finally, the radiometric calibration problem is transformed into equating two independent relations for the image sensor gains through the specified distribution.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1723-1728
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• 2008

An efficient synthetic route for carbocyclic versions of stavudine analogues and their evaluation on antiviral activity are described. The construction of an ethynylated quaternary carbon at the 4'-position of carbocyclic nucleosides was accomplished using Claisen rearrangement of 11 and ring-closing metathesis (RCM) of dienyne 14 as key transformations. An antiviral evaluation of the synthesized compounds, 20, 21, 22, and 25 against HIV-1, HSV-1, HSV-2, and HCMV showed that only the guanine analogue 25 is moderately active against HIV-1 in the MT-4 cell line ($EC_{50}$ = 11.91 $\mu$mol).

• International Journal of Quality Innovation
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• v.7 no.2
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• pp.97-124
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• 2006

The purpose of this research is to create an expert risk-based piping system inspection model. The proposed system includes a risk-based piping inspection system and a piping inspection guideline system. The research procedure consists of three parts: the risk-based inspection model, the risk-based piping inspection model, and the piping inspection guideline system model. In this research procedure, a field plant visit is conducted to collect the related domestic information (Taiwan) and foreign standards and regulations for creating a strategic risk-based piping inspection and analysis system in accordance with the piping damage characteristics in the petrochemical industry. In accordance with various piping damage models and damage positions, petrochemical plants provide the optimal piping inspection planning tool for efficient piping risk prediction for enhancing plant operation safety.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.97-100
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• 2002

NaEr(WO$_4$)$_2$ is a new laser material. The planar optical waveguide was formed in NaEr(WO$_4$)$_2$ crystal by 2.6 MeV He$^{+}$ ion implantation at doses of 1.0-1.5 $\times$ 10$^{16}$ ions/cm$^2$ at room temperature. The effective refractive indices of the dark modes were measured using the prism coupling method. foul n modes and five TM modes were observed in the waveguide. The refractive index profiles were analyzed using the reflectivity calculation method (RCM). The influence of heat treatment at moderate temperature on the refractive index profiles of the waveguide was also investigated. We used the TRIM'98 (Transport of ton in Matter) code to simulate the damage profile in the NaEr(WO$_4$) crystal by 2.6 MeV He$^{+}$ion implantation which is helpful for a better understanding of the waveguide formation.ion.

• Journal of Korea Water Resources Association
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• v.49 no.2
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• pp.107-119
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• 2016

Since future climate scenarios indicate that extreme precipitation events will intensity, probable maximum precipitations (PMPs) without being taken climate change into account are very likely to be underestimated. In this study future PMPs in accordance with the variation of future rainfall are estimated. The hydro-meteorologic method is used to calculate PMPs. The orographic transposition factor is applied in place of the conventional terrain impact factor which has been used in previous PMPs estimation reports. Future DADs are indirectly obtained by using bias-correction and moving-averaged changing factor method based on daily precipitation projection under KMA RCM (HEDGEM3-RA) RCP 8.5 climate change scenario. As a result, future PMPs were found to increase and the spatially-averaged annual PMPs increase rate in 4-hour and $25km^2$ was projected to be 3 mm by 2045. In addition, the increased rate of future PMPs is growing increasingly in the future, but it is thought that the uncertainty of estimating PMPs caused by future precipitation projections is also increased in the distant future.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.58-65
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• 2000

Use of a pectinase during preparing handmade papers from bast fiber of paper mulberry(Broussonetia kazinoki Sieb.) was investigated in order to decrease cooking chemicals and environmental pollution. For this purpose, four kinds of commercial pectinases, Rapidase LIQ(RLP), Rapidase Press(RP), Rapidase C80L Max(RCM) and Pectinase SS Kyowa(PSK) were used. And the durability of handmade papers before and after pectinase treatment was determined. RP and PSK had higher pectinase activity ad lower cellulase activity. The bast fiber was not defibered when pectinase was used. In order to increase the efficiency of enzymes, the bast fiber were treated ammonium oxalate(AO) or $K_2CO_3$under mild conditions. The AO pretreatment with those produced by $K_2CO_3$. The RP treated pulps after mild $K_2CO_3$cooking of the bast fiber were defibrated more easily than untreated pulp. The handmade paper prepared with the RP treated pulps after mild $K_2CO_3$cooking has good strength properties such as breaking length and folding endurance. Also, it has higher durability on heat aging, though its brightness was slightly lower than that of untreated paper.