• Explosives and Blasting
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• v.22 no.3
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• pp.79-84
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• 2004

It is well accepted that modem emulsion explosives are intrinsically much less sensitive than traditional products such as dynamites or black powder. However, they have still been involved in a significant number of accidental explosions. In October 1975, Canadian Research, Limited's, Energetic Research Laboratory in Quebec exploded. Although explanations for the incident varied, one logical explanation was that the pump used in transporting the emulsion dead headed, thereby turning mechanical work in to frictional heating under a zero flow rate. There is a minimum pressure required for combustion(MBP) to propagate in emulsion explosives. A stable deflagration may lead to a deflagration-to-detonation transition(DDT) in emulsion explosives. Tests were also performed on sensitized sampled consisting of 6 to 21% waters as well as 1 to 11% aluminium powder. It was founded the emulsion explosives consisting of 6% waters had the lowest minimum homing pressure(MBP) of 3 bar, and the 21% waters were unable to achieve sustained homing at pressures as high as 100 bar. The aluminium contained explosives tested here displayed a MBP higher than that of without emulsion. It appears that this test may offer a firm ground for the classification of emulsion explosives in view of the regulating the hazards associated with the various process used for their manufacturing and transport.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.247-255
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• 2016

Non-point pollutants from surface runoff during rainfall exert adverse effects on urban river water quality management. In particular, the first flush effect during the initial phase of rainfall can deliver significant amounts of pollutant loads to surface waters with extremely high concentrations. In this study, a sustainable first flush effect management system was developed by using settling and filtration that require no additional power or chemicals. A pilot scale experiment has shown that the removal of total suspended solid (TSS), total nitrogen (TN) and total phosphorus (TP) are in ranges of 84 - 95%, 31 - 46%, and 42 - 86%, respectively. An Integrated Stormwater Runoff Management System (ISTORMS) was also developed to efficiently manage the developed system by linking weather forecast, flow rate and water quality modeling of surface runoff and automatic monitoring systems in fields and in the system. This study can provide effective solutions for the management of urban river in terms of both quantity and quality.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.279-285
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• 2012

The Mume Fructus (MF) has been used for relieves cough, arrests arrest chronic diarrhea, treat fluid depletion, and treat ascariasis in Korea. In this study, a high-performance liquid chromatography (HPLC) method was established for simultaneous determination of six main components of MF. Additionally, we were investigated the anti-inflammatory and anti-allergic effects of MF extract on lipopolysaccharide (LPS)-treated RAW264.7 cells and tumor necrosis factor (TNF)-${\alpha}$/interferon (IFN)-${\gamma}$-treated HaCaT cells. The analytical column for separation was used a Gemini $C_{18}$ column maintained at $40^{\circ}C$. The mobile phase consisted of 1.0% (v/v) acetic acid in water (A) and 1.0% (v/v) acetic acid in acetonitrile (B). The flow rate was 1.0 mL/min and the detector was a photodiode array (PDA) set at 280 nm and 320 nm. We evaluated the inhibitory effect of MF extract on the production of inflammatory markers, nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) in LPS-stimulated RAW264.7 cells and thymus- and activation-regulated chemokine (TARC/CCL17) in TNF-${\alpha}$/IFN-${\gamma}$-treated HaCaT cells, respectively. We confirmed the genes expression related with TARC, macrophage-derived chemokine (MDC/CCL22) and regulated on activation, normal T cell expressed and secreted (RANTES/CCL5) in HaCaT keratinocyte cells by MF extract. The contents of the five compounds in MF were 0.22-1.01 mg/g. Also, the MF extract show inhibition of about 78% and 75% on NO and $PGE_2$ production at the concentration 1000 mg/mL in RAW264.7 cells. MF extract suppressed the hTARC level and genes expression such as TARC, MDC, and RANTES on TNF-${\alpha}$/IFN-${\gamma}$-treated HaCaT cells.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1349-1354
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• 2013

Sealing structure to prevent flowing hot gas into the driving device, located between the driving shaft and the liner of On-Off valve for controlling the hot gas flow path was studied. Wear occurs due to the constant movement of the driving shaft controlled by actuator on graphite as the sealing material. In this paper, the dynamic wear behavior in high temperature of graphite(HK-6) to be used as sealing material was evaluated. Reciprocating wear test was carried out for the graphite(HK-6) to the relative motion between shaft materials(W-25Re). The results of friction coefficient and specific wear rate according to contact load, sliding speed at room temperature and $485^{\circ}C$ considering the actual operating environment were evaluated. Through the SEM analysis of the worn surface, third body as lubricant films were observed and lubricant effect of third body was considered.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.223-235
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• 2012

In this paper, field study results about accumulation of sediments and its property in the forebay of wetland aiming at stormwater from rural area wherein intensive cow feeding lots are operated are provided. In addition, some design aspects are discussed. Amount of sediment generation in the longitudinal direction of forebay was found to be affected by hydrological factors such as rainfall depth and intensity. Nutrient contents in the sediments of this wetland were 10 times higher than those in stormwater wetland in rural area without animal-feeding lot. Total-Pb and As contents show similar level to values from the soils of surrounding watershed, but Total-Cu content was higher due to the animal feeding lots. Yearly amount of sediment generation, its depth and volume were estimated to 13tons, 23cm, and $65m^3$. Based on these results and recommended guideline by Korean Ministry of Environment, dredging frequency was found to be about 2.7years. The shape of forebay has to be carefully designed to deal with a great change in flow rate. According to the results of sediment depth analysis, instead of the present rectangular, wedge-shape forebay is more desirable in handling scouring caused by high flows.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.181-189
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• 2018

This study was performed to analyze the dynamics and distributional condition of biological community and to support the basic information about the estuarine ecosystem management by using the intensively surveyed results by each taxon experts around Tamjin river. We analyzed the biological diversity, abundance, correlation among species, and ecological characteristics about 11 taxa groups including vegetation, fish, birds, mammals, etc. in the Tamjin river estuarine ecosystem. We classified vegetation types into 7 physiognomic types and 18 communities according to habitat conditions with the physical environments and salinity. In total, 1125 species including 9 species of endangered species were identified in research area. The species composition and distributional characteristics of each taxon were corresponded to the environmental characteristics of the estuarine ecosystem. Especially, the species diversity and distribution were clearly distinguished in the river according to the difference of the environmental factors such as flow rate, salinity, and soil. Despite the disturbance factors such as barrage and levees, the biodiversity and its distribution were evaluated to be high level under the current environmental conditions. However, loss or reduction of wildlife habitat due to reclamation, embankment, barrage installation and expansion of farmland has been identified as a major threat to the diversity and health of the local ecosystem. The results of this study can be used as a basic data to cope with various development pressure and damage crisis of the whole estuaries including Tamjin river.

• Journal of Pharmaceutical Investigation
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• v.40 no.2
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• pp.101-107
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• 2010

A rapid and sensitive reversed-phase high performance liquid chromatography (HPLC) method was developed for the determination of N-(-4-Chlorophenyl)-6-hydroxy-7-methoxy-2-chromanecarboxamide (KAL-1120), a novel anti-inflammation agent, in the rat plasma. The method was applied to analyze the compound in the biological fluids such as bile, urine and tissue homogenates. After liquid-liquid extraction, the compound was analyzed on an HPLC system with ultraviolet detection at 275 nm. HPLC was carried out using reversed-phase isocratic elution with a $C_{18}$ column, a mobile phase of a mixture of acetonitril (40 v/v%) at a flow rate of 1.0 mL/min. The chromatograms showed good resolution and sensitivity and no interference of plasma. The calibration curve for the drug in plasma was linear over the concentration range of 0.05-50 ${\mu}g$/mL. The intra- and inter-day assay accuracies of this method ranged from 0.06% to 9.33% of normal values and the precision did not exceed 6.28% of relative standard deviation. The plasma concentration of KAL-1120 decreased to below the quantifiable limit at 1.5 hr after the i.v. bolus administration of 2-10 mg/kg to rats ($t_{1/2,({\alpha})}$ and $t_{1/2,({\beta})$ of 2.15 and 26.7 min at a dose of 2 mg/kg, 3.91 and 33.0 min at a dose of 10 mg/kg, respectively). The steady-state volume of distribution ($V_{dss}$) and the total body clearance ($CL_t$) were not significantly altered in rats given doses from 2 to 10 mg/kg. Of the various tissues tested, KAL-1120 was mainly distributed in the lung and heart after i.v. bolus administration. KAL-1120 was detected in the bile by 30 min after its i.v. bolus administration. However, the concentration in the urine after i.v. bolus administration became too low to measure, suggesting that KAL-1120 is mostly excreted in the bile. In conclusion, this analytical method was suitable for the preclinical pharmacokinetic studies of KAL-1120 in rats.

• Journal of the Korean association of regional geographers
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• v.23 no.1
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• pp.168-177
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• 2017

In order to reveal formation factors and developmental processes of tafoni this study was conducted with petrological analysis including microscopic observation, measurement of water content and water analysis at Golgulsa temple in Gyeongju, South Korea. The direction of the entrance to tafoni at Golgulsa temple tends to coincide with the direction of slope, and this is thought to be related to the direction of wind flow and water supply. Tafoni's initial developmental processes is judged to have grown as a result of a breakaway of rock fragments along with beddings and cracks in rock. Then, tafoni have been enlarged along at the spots that sufficiently accommodate water supply depending on the direction of wind. The results of water analysis of the stagnant water in gnamma implies that a high meltage of Na and Cl compared to other inland areas can be from the adjacent shore. The effects of such saline substances on rock weathering and development of taponi are currently under way through electronic microscopy and geochemical analysis.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.1-12
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• 2005

Treatment level and pond reactions of a pond system were examined from May to October 2002. The system was constructed in July 2000 for purifying water of Sinyang stream that flows into Koheung Estuarine Lake located in the southern part of the Korean Peninsula. The system was composed of a primary and a secondary pond in series and established on the rice field near the lake. Water pumped from the stream was funneled into the primary pond, whose effluent was discharged into the secondary pond by gravity flow. Effluent from the secondary pond was funneled into wetlands. About 130 $m^3$/day of water was pumped into the primary pond and detention time of the primary and secondary pond was about 2 days. DO from the surface to the 1.0 m depth of the primary and secondary pond was in the rage of 5.2 to 11.0 mg/L and 4.3 to 0.7 mg/L, respectively. DO at the bottom layer of the primary pond was 0 mg/L and that of the secondary pond ranged 3.0~4.7 mg/L. The primary pond functioned as a facultative pond and the secondary as an aerobic one. The temperature difference between the surface and bottom layers of the ponds in August was about $2.5^{\circ}C$ and that in May and October was about $1.0^{\circ}C$. Thermocline was observed in the primary pond during the high ambient temperature of August. The sludge depth of the primary pond in May, August, and October was 2.4, 1.9, and 2.2 cm, respectively. That of the secondary pond was 1.2, 1.0, and 1.1 cm, respectively. SS, $BOD_5$, T-N, and T-P concentrations in influent averaged 16.64, 6.71, 6.21, and 0.23 mg/L and those in effluent from the primary pond averaged 11.48, 4.97, 4.81, and 0.17 mg/L, respectively. The removal rates of the primary pond for SS, $BOD_5$, T-N and T-P were 31%, 26%, 22%, and 24%, respectively. Average concentrations of SS, $BOD_5$, T-N, and T-P in effluent from the secondary pond were 9.81, 4.07, 4.03, and 0.14 mg/L, respectively and the abatement rates of the secondary pond for SS, $BOD_5$, T-N and T-P were 20%, 12%, 13%, and 15%, respectively. SS, $BOD_5$, T-N and T-P concentrations in effluent from the primary pond were significantly low(p=0.001) when compared with those from the secondary one.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.532-537
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• 2014

Cortex Phellodendri (CP) is derived from the dried bark of Phellodendron amurense. It has been widely used as a drug in traditional Korea medicine for treating diarrhea, jaundice, swelling pains in the knees and feet, urinary tract infections, and infections of the body surface. Many analytical methods have been used to study oriental herbal medicines, such as thin-layer chromatography, column liquid chromatography, and high performance liquid chromatography (HPLC). In this study, preparative centrifugal partition chromatography (CPC) was successfully carried out in order to separate pure compounds from a CP methanol extract. The optimum two-phase CPC solvent system was composed of n-butanol: acetic acid: water (4:1:5 v/v/v). The flow rate of the mobile phase was 3 mL/min in ascending mode with rotation at 1,000 rpm. The CPC-separated fraction and purification procedures were carried out by preparatory HPLC. The $^1H$ NMR spectrum revealed that the resonances at ${\delta}$ 4.10 and 4.20 ppm corresponded to three protons ($-OCH_3$), whereas those at ${\delta}$ 6.10 ppm corresponded to two protons ($-OCH_2O-$). Further, two aromatic protons (H-11 and H-12) conveys a doublet-doublet pattern. The H-11 doublet and H-12 doublet appear at ${\delta}$ 7.98 and 8.11, respectively. The $^{13}C$ NMR. spectrum showed a tetrasubstituted with a methylenedioxy group at C2 and C3, and two methoxy groups at C9 and C10. The chemical structure of the berberine was identified by $^1H$, $^{13}C$-nuclear magnetic resonance and electrospray ionization-mass spectroscopy spectral data analysis.