• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.105-115
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• 2014

A numerical analysis on the smoke behavior and evacuee safety has been performed with computational fluid dynamics. The purpose of this study is to build computational processes for an evacuation and prevention of a fire disaster of a 3 km-length tunnel in Korea. To save computational cost, 1.5 km of the tunnel that can include a few cross-passing tunnels is considered. We are going to assess the fire safety in a road tunnel according to the smoke level, which consists of the smoke density and the height from the floor. The smoke density is obtained in detail from three-dimensional unsteady CFD analysis. To obtain proper temperature distributions on the tunnel wall, one-dimensional conduction equation is considered instead of an adiabatic wall boundary or a constant heat flux. The tunnel considered in this study equips the cross passing tunnels for evacuees every 250 m. The distance is critical in both safety and economy. The more cross passing tunnels, the more safe but the more expensive. Three different jet fan operations can be considered in this study; under- and over-critical velocities for normal traffic condition and 0-velocoty operation for the traffic congestion. The SE (smoke environment) level maps show a smoke environment and an evacuating behavior every moment.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.247-256
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• 2017

Background: KG-135, a standardized formulation enriched with Rk1, Rg3, and Rg5 ginsenosides, has been shown to inhibit various types of cancer cells; however, the underlying mechanisms are not fully understood. In this study, we explored its effects in A549 human lung cancer cells to investigate the induction of Forkhead Class box O3a (FOXO3a) and autophagy. Methods: Cell viability was determined by sulforhodamine B staining. Apoptosis and cell cycle distribution were analyzed using flow cytometry. The changes of protein levels were determined using Western blot analysis. Autophagy induction was monitored by the formation of acidic vesicular organelles stained with acridine orange. Results: KG-135 effectively arrested the cells in G1 phase with limited apoptosis. Accordingly, a decrease of cyclin-dependent kinase-4, cyclin-dependent kinase-6, cyclin D1, and phospho-retinoblastoma protein, and an increase of p27 and p18 proteins were observed. Intriguingly, KG-135 increased the tumor suppressor FOXO3a and induced the accumulation of autophagy hallmark LC3-II and acidic vesicular organelles without an increase of the upstream marker Beclin-1. Unconventionally, the autophagy adaptor protein p62 (sequestosome 1) was increased rather than decreased. Blockade of autophagy by hydroxychloroquine dramatically potentiated KG-135-induced FOXO3a and its downstream (FasL) ligand accompanied by the cleavage of caspase-8. Meanwhile, the decrease of Bcl-2 and survivin, as well as the cleavage of caspase-9, were also drastically enhanced, resulting in massive apoptosis. Conclusion: Besides arresting the cells in G1 phase, KG-135 increased FOXO3a and induced an unconventional autophagy in A549 cells. Both the KG-135-activated extrinsic FOXO3a/FasL/caspase-8 and intrinsic caspase-9 apoptotic pathways were potentiated by blockade of autophagy. Combination of KG-135 and autophagy inhibitor may be a novel strategy as an integrative treatment for cancers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.3
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• pp.1-4
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• 1982

By high performance liquid chromatography, separation and quantification of glucoalkaloids $({\alpha}-chaconine$and${\alpha}-solanine)$ from potato (Solanum tuberosum, var. May Queen) was established using periderm and cortex. $Nucleosil-NH_2\;(10{\mu}m)$ was packed in two stainless steel columns ($4.0\;ID{\times}15\;cm$ and $4.0\;ID{\times}25\;cm$) which were connected in sequence and eluted with the mixture of tetrahydrofuran, phosphoric acid buffer and acetonitrile (50 : 25 : 25, v/v/v) at the flow rate of 1ml/min. and the absorbance were read at 208 nm. Retention time was 6.92 min. for ${\alpha}-chaconine$ and 10.96 min. for ${\alpha}-solanine$ with complete separation. This method took 12 min. per sample and seemed best. ${\alpha}-Chaconine$ and ${\alpha}-solanine$ were found much in periderm than in cortex.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1265-1273
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• 2006

The environmental capacity and watershed pollution load reduction of Yongdam reservoir were estimated by the simulation of water quality variation process with the target water quality establishment, pollution load estimation and flow analysis. The potable raw water $I{\sim}II$, COD $1.0{\sim}3.0$ mg/L and TP $0.01{\sim}0.03$ mg/L were selected as the target water quality Yongdam reservoir water quality model was constructed with WASP5 contained 42 segments and the correlation of calibrated results were BOD 0.73, $PO_4-P$ 0.98. The environmental capacity for target quality COD 2.0 mg/L and TP 0.02 mg/L were BOD $131,880{\sim}4,694$ kg/d, TP $7,855 {\sim}167$ kg/d which were less than exists, and the related reduction ratios were BOD $51{\sim}62%$, TP $47{\sim}67%$ which were middle amount in exists. The load reduction ratios to meet the potable raw water $I{\sim}II$ were BOD $72{\sim}16%$, TP $78{\sim}36%$ in existing conditions and BOD $81{\sim}44%$, TP $84{\sim}52%$ in new conditions. BOD was the least one and TP was the second least in 4 results. The effects of the load reduction assignment to subbasin were dominant in TP but little in COD.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.62-73
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• 2014

This research was focused to apply response surface methodology for optimization of bio-methane production by biogas upgrading process. Methane concentration(Y1) and methane efficiency(Y2) on biogas upgrading process were mathematically described as being modeled by the use of the Box-Behnken design on response surface methodology. The results of ANOVA(analysis of variance) about models, the probability value of the methane concentration and methane recovery response surface model are 0.0001 and 0.0001, respectively and coefficient of determination($R^2$) are 0.9788 and 0.9710, respectively. The response surface model is proved of high reliability and suitability. The operation pressure had the greatest influence to methane concentration than other operation parameters and the PSA rotary valve velocity had the greatest influence to methane recovery than other operation parameters. Optimal condition of biogas upgrading process for production of $100Nm^3/hr$ bio-methane were operation pressure 8.0bar and outlet flow rate 31.55RPM, respectively. At that operation condition the methane concentration of bio-methane was 97.13% and methane recovery in biogas upgrading process was 75.89%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.203-209
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• 2019

In this work, a new land-specific resistance measuring device (GM) and a measuring probe (Grounding Rod) are connected to the WENNER quadrant as power-line communication (PLC). In groups of two (P1,P2) probes, five to ten probes are installed in series on the ground at intervals of 1m, 2m, 4m, 8m, and 16m, respectively. If the PLC signal from the GMD is detected by the receiver of the Probe 1 (P1) for measurement, the minute voltage and current for measurement flow from the PSD (power supply) attached to the probe to the ground, and then, through the soil between P1 and P2, enters the Probe 1 (P2). The resistance value is then measured by the principle of voltage drop due to ground resistance. Measure the earth resistance every T seconds up to 1 trillion and store the measured data on the Arduino Server mounted on the main equipment. Stored measurement data can be derived from formulas by Ohm's Law and from inherent resistance (here,). Data obtained in real time will be linked to CDGES programs installed on Main PC, enabling data analysis and real-time monitoring of the ground environment on land. In addition, a three-dimensional display is possible with 3D graph support by identifying seasonal characteristics such as temperature and humidity of land (soils). The limitations of the study will require specific application measures of Test Bed for commercial access to a model that has been developed and operated experimentally.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.295-306
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• 2008

The Intersection is inner traffic facilities and the space where the roads are intersected and connected. And also, the Intersection is the decision-making section for drivers to select the route according to the geometric structure and operation method. However decision-making section cause to raise car accidents rate because it imposes a heavy burden on drivers. In that reason, many countries such as Europe use the Roundabouts to reduce the numbers of decision making and collision. In Korea, the kinds of method are just introduced and it is using now but there are no exact standards. Hence, this study suggests the process to evaluate and determine the types of Intersection which are based on the traffic flow (congestion) and traffic safety (accidents). Firstly, this study presents the number of accident at each Intersection which is depended on the traffic volume. Secondly, this study calculates and analysis the accident at signalized Intersection, non-signalized Intersection and Roundabout by TSIS-NETSIM program. Thirdly, this study concludes the best suitable Intersection type through the materials which are mentioned before.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.553-573
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• 2013

This paper aims to give a summary and review of the research trend about subjects of Asian Dust (AD) storm in the last three decades. The AD research was focused on classification of synoptic scale data and finding inflow pathway in early stage. Recently, new approaches have been made to explain chemical composition, transportation, transboundary movement reaction of AD, using satellite data, 3D modeling, the aerosol time of flight mass spectroscopy, etc. During AD events, a large amount of dust particles flow into Korea and Japan from AD source areas, and they are highly likely to be mixed with toxic substances when air mass contained AD particles pass over seriously polluted areas. We concluded that, considering that AD events were classified into two cases according to the source area and pathway, the concentrations of crustal components did not increase at the initial stage of AD events, Whereas ammonium-sulfate, trace metal element, OC, EC relatively increased in the early stage. This explains AD events have the possibility of being accompanied with polluted air mass or particles. Also, we further need to compare and summarize the results of AD studies which already have been conducted, and prepare strategies for particle management, particularly for Black Carbon (BC) and Brown Carbon (BrC) which are considered to induce climate change effects.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.115-120
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• 2012

Retinoic acid plays an important role in the regulation of cell growth and differentiation. In our present study, we evaluated the effects of all-trans retinoic acid (RA) on cell proliferation and on the cell cycle regulation of human gingival fibroblasts (HGFs). Cell proliferation was assessed using the MTT assay. Cell cycle analysis was performed by flow cytometry, and cell cycle regulatory proteins were determined by western blot. Cell proliferation was increased in the presence of a 0.1 nM to 1 ${\mu}M$ RA dose range, and maximal growth stimulation was observed in cells exposed to 1 nM of RA. Exposure of HGFs to 1 nM of RA resulted in an augmented cell cycle progression. To elucidate the molecular mechanisms underlying cell cycle regulation by RA, we measured the intracellular levels of major cell cycle regulatory proteins. The levels of cyclin E and cyclin-dependent kinase (CDK) 2 were found to be increased in HGFs following 1 nM of RA treatment. However, the levels of cyclin D, CDK 4, and CDK 6 were unchanged under these conditions. Also after exposure to 1 nM of RA, the protein levels of $p21^{WAF1/CIP1}$ and $p16^{INK4A}$ were decreased in HGFs compared with the control group, but the levels of p53 and pRb were similar between treated and untreated cells. These results suggest that RA increases cell proliferation and cell cycle progression in HGFs via increased cellular levels of cyclin E and CDK 2, and decreased cellular levels of $p21^{WAF1/CIP1}$ and $p16^{INK4A}$.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.109.2-109.2
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• 2015

Graphene, as a single layer of $sp^2$-bonded carbon atoms packed into a 2D honeycomb crystal lattice, has attracted much attention due to its outstanding properties such as high carrier mobility, chemical stability, and optical transparency. In order to synthesize high quality graphene, transition metals, such as nickel and copper, have been widely employed as catalysts, which need transfer to desired substrates for various applications. However, the transfer steps inevitably induce defects, impurities, wrinkles, and cracks of graphene. Here, we report a facile transfer-free graphene synthesis method through nickel and carbon co-deposited layer, which does not require separately deposited catalytic nickel and carbon source layers. The 100 nm NiC layer was deposited on the top of $SiO_2/Si$ substrates by nickel and carbon co-deposition. When the sample was annealed at $1000^{\circ}C$, the carbon atoms diffused through the NiC layer and deposited on both sides of the layer to form graphene upon cooling. The remained NiC layer was removed by using nickel etchant, and graphene was then directly obtained on $SiO_2/Si$ without any transfer process. Raman spectroscopy was carried out to confirm the quality of resulted graphene layer. Raman spectra revealed that the resulted graphene was at high quality with low degree of $sp^3$-type structural defects. Furthermore, the Raman analysis results also demonstrated that gas flow ratio (Ar : $CH_4$) during the NiC deposition and annealing temperature significantly influence not only the number of graphene layers but also structural defects. This facile non-transfer process would consequently facilitate the future graphene research and industrial applications.