• Journal of Environmental Science International
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• v.17 no.10
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• pp.1147-1154
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• 2008

Road runoff, one of non-point source pollutants, contains various heavy metals, most of which flow into discharge waters without being treated. The mechanism of removing the heavy metals in water is similar to that of removing micro-particles. Therefore, it is considered that it is possible to remove a lot of the heavy metals contained in the road runoff by filtering or absorbing them. In this paper, performed has been a basic study on the characteristics of UNFS (Up Flow Non-Point Source Filtering System) using carbide pellet and zeolite pellet as double-layer filtering mediums to treat the road runoff. The removal rate with filtering and absorption time has been shown as follows: 29.0% for Cr; 27.8% for Cd; 25.7% for Fe; 25.4% for Co; 21.2% for Pb; ]9.6% for Zn; 18.2% for Al; 17.0% for Mn; 11.3% for Ni; 7.5% for Cu. The overall removal rate according to influx change has been shown to be approximately 30%, and the load of heavy metals flowing out in initial precipitation could be reduced by using carbide as a recycling filtering medium. When the removal as coarse particles settle is added up, it is expected that UNFS will result in a higher removal rate.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.45-50
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• 2006

About 50% of the population and 75% of the properties concentrate on the flood plain in Japan. The rivers have intimate relationship with our lives. Those conditions have been seen after modern river improvement projects that began about a century ago. The technology which was introduced from foreign countries was improved in conformity with geographical features and the climate condition of our nation, and has redeveloped as a Japanese original technology. In 1940's, Japan had serious natural disasters that were caused by large- scale typhoons. Those typhoons wiped out everything completely. Even though the government realized the importance of flood control and management after those natural disasters, civil work still aimed to economic development. Those construction works have become the one of factors for concentrating population and degrading natural environment in urban areas. Deterioration of river environment has become serious issue in urban development and main cause of pollution. The approaches for environmental restorations which were started about 30 years ago aimed to harmonize with nature environment and cities and human lives. There have been going on many projects called 'river environmental improvement projects', the 'nature friendly river works' and 'natural restoration projects.' The society has tried to find a way to live in harmony with nature. As for societies symbiotic with habitats will form the safe country in the history and the spectacle. Such as the symbiotic of the river or the basin where discharge, water quality, nature, the history, landscape, the local society and also for culture were built in is achieved. Examples of working, applied to restoration technologies and the one to describe the mechanism construction are been shown in the paper. Furthermore, write for an international spread of the river technology of Japan to attempt.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.13-19
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• 2012

The purpose of this study is to extract the major factors related to the deterioration mechanism of white organic light-emitting diodes(WOLED) by performing accelerated testing of temperature, voltage, time, etc., and to develop an accelerated life test(ALT) model. The measurement results of the brightness of the WOLED exhibited that their average brightness tended to increase as the operating voltage increased and that the half-life period of the brightness appeared after approximately 400 hours when the operating voltage was 20V and the ambient temperature was $85^{\circ}C$. It could be seen that although the WOLED showed comparatively the same brightness when the initial acceleration began after the operating voltage was applied to it, its brightness changed excessively after the WOLED's thermal storage had been made. In addition, it was observed that the half-life period was reduced as the ambient temperature and applied voltage increased. The strength of the WOLED which had been maintained in the range of visible light at the maximum load was reduced by the deterioration of the organic light emitting material due to the influence of the operating voltage and temperature, and the reduction of emitted light was small at low voltage and temperature. It could be seen that the failure of the WOLED during the ALT was caused by wear due to load accumulation over time, and that Weibull distribution was appropriate for the life distribution and acceleration was established between test conditions. From the WOLED analysis, it is thought that factors influencing the brightness deterioration are voltage, temperature, etc., and that comprehensive analysis considering discharge control, dielectric tangent margin, etc., would further increase the reliability.

• 한국해양학회지
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• v.23 no.1
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• pp.1-12
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• 1988

To clarify the community structure of phytoplankton in the Kyeonggi Bay, the community analysis were performed to investigate the relationship between the environmental factors and the phytoplankton communities. Low diversity with occurrence of few dominant species throughout the year, except summer, implies that ecological environment of this study area is very unstable due to incessant physical perturbation and large fluctuation of other environmental factors. According to the results of the cluster analysis this study area could be divided into river discharge, polluted and unpolluted area. Principal component analysis of overall phytoplankton community in this area clearly showed four seasonal succession patterns grouped into the spring type, the summer type, the late summer type, the late autumn-winter type. Summer communities composed of common phytoplankton are highly correlated with temperature and transparency. Winter communities composed of most tychopelagic plankton are positively correlated with suspended substances and nutrient, while negatively correlated with transparency.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.1-6
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• 2001

Background: Subcutaneous injection of 5% formalin into the hind paw of the rat produces a biphasic nociceptive response. The second phase depends on changes in the dorsal horn cell function that occur shortly after an initial C-fiber discharge, spinal sensitization, or windup phenomenon. This study was performed to investigate the role of glutamate during spinal sensitization. Methods: Sprague-Dawley rats weighing 200 to 250 g were used for this study. Under light anesthesia (0.5% isoflurane) the rats were segregated in a specially designed cage and $50{\mu}l$ 0.5% formalin was injected subcutaneously in the foot dorsum of right hindlimb. Forty minutes after the formalin injection, the rat was quickly decapitated and spinal cord was removed. The spinal segments at the level of L3 (largest area) was collected and stored in a deep freezer ($-70^{\circ}C$). The mRNA gene expression of N-methyl-D-aspartate receptor (NMDAR) and the metabotropic glutamate receptor subtype 5 (mGluR5) were determined by the polymerase chain reaction. Results: The number of flinches was $19.8{\pm}2.3/min$. at one minute after formalin injection and decreased to zero after then. The second peak appeared at 35 and 40 minutes after formalin injection. The values were $17.8{\pm}2.2$ and $17.2{\pm}3.0/min$. The mRNA gene expressions of NMDAR and mGluR5 were increased by $459.0{\pm}46.8%$ (P < 0.01) and $111.1{\pm}4.8%$ (P > 0.05) respectively at 40 minutes after formalin injection. The increased rate of NMDAR was significantly higher than that of mGluR5 (P < 0.01). Conclusions: From these results it suggested that NMDAR partly contributed to the mechanism of central sensitization after the formalin test but mGluR5 did not.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2668-2676
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• 2011

In order to analyze the variation in length of stay(LOS) of injury inpatients, we developed severity-adjusted LOS model using Korean National Discharge In-depth Injury Survey data of Center for Disease Control. Appling this model, we calculated predicted values and, after standardizing LOS using the differences from the actual values, analyzed the variation in LOS. Major factors affecting severity-adjusted LOS of injury inpatients were found to be severity, surgery(or no surgery), age, injury mechanism and channel of hospitalization. Result of analysis of the differences between the actual values and predicted values adjusted by decision tree model suggested that there were statistically significant differences by hospital size(number of beds), type of insurance and location of institution. In order to reduce the variation in LOS, efforts should be exerted in developing nationwide treatment protocol, inducing medical institutions to utilize it, and furthermore systematically evaluating it to reduce the variation continually.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.3
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• pp.219-226
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• 2012

The International Maritime Organization (IMO) adopted the International Convention for the Control and Management of Ships' Ballast Water and Sediments in 2004 to prevent the transfer of aquatic organisms via ballast water. Thirty-four ballast water treatment systems were granted IMO active substance basic approval, among which twenty systems were granted final approval. This paper is an in-depth consideration of the mechanism principles of the treatment systems that received active substance basic or final approval from IMO, and on the concentration of Total Residual Oxidant (TRO). The TRO maximum allowable discharge concentration was reduced by neutralization equipment, resulting with a concentration lower than 0.2 ppm. However, between various treatment systems TRO maximum allowable dosage showed large differences, ranging from 1 to 15 ppm. The discrepancies of treatment allowable dosage concentration between different treatment systems are largely due to the properties of species and water conditions such as the temperature and turbidity, rather than the characteristics of treatment systems and the type or presence of filters etc.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1780-1782
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• 2001

In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using $BaTiO_3$-sludge packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50[ppm] balanced with air, a gas flow rate of 5[1/min]. $BaTiO_3$ pellets are filled at upstream of reactor for corona discharge and sludge pellets are put at downstream of reactor for catalystic effect. The volume rate of sludge pellets to $BaTiO_3$ pellets is 50[%] and AC voltage to dischare the gases was supplied. In the result, when sludge pellets is seperated to $BaTiO_3$ by other reactor and AC voltage is supplied to $BaTiO_3$ and sludge pellets NO, $NO_2$ removal rate is higher. When gas temperature increase from room temperature to 100[$^{\circ}C$], NO removal is decreased while $NO_2$ concentration is independent on gas temperature. This result suggest that the removal mechanism of active oxyzen species and $NO_2$ in sludge is not absorption, but chemical reaction. Temperature of heating treatment is on sludge pellets increased, $NO_x$ removal rate is decrease. It is thought that organic compound is removed by heating treatment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.767-774
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• 2012

A fluidic device (FD) has been adopted in the safety injection tanks (SITs) of APR1400. A flow control mechanism of the FD was used to vary the flow regime in the vortex chamber corresponding to the SITs water level. The flow regime in the vortex chamber has a different pressure loss from low to high in accordance with the SITs water level. Nitrogen at the top of the SIT could be released owing to inertia of discharge flow when changing from a high flow rate to a low flow rate. This phenomenon is important to design improvement perspective because it can affect the performance of the FD. This paper shows a result of a preliminary numerical study to obtain the transient data related to air release in the flow turn-down period using a two-fluid free-surface model provided from ANSYS CFX 13.0. In conclusion, there is no significant effect on the performance of the FD, though a small quantity of air is released during the flow turn-down period.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.100-105
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• 2001

An all solid-state thin film battery (TFB) was fabricated by growing, undoped and Pt-doped vanadium oxide cathode film ( $V_2$ $O_{5}$ ) on I $n_2$ $O_3$: Sn coated glass, respectively. Room temperature charge-discharge measurements based on Li/Lipon/ $V_2$ $O_{5}$ full-cell structure with a constant current clearly shows that the Pt-doped $V_2$ $O_{5}$ cathode film is superior, in terms of cyclibility. X-ray diffraction (XRD) results indicate that the Pt doping process induces a more random amorphous structure than an undoped $V_2$ $O_{5}$ film. In addition to its modified structure, the Pt-doped $V_2$ $O_{5}$ film has a smoother surface than the undoped sample. Compared to an undoped $V_2$ $O_{5}$ film, the Pt doped $V_2$ $O_{5}$ cathode film has a higher electron conductivity. We hypothesize that the addition of Pt alters electrochemical performance in a manner of making more random amorphous structure and gives an excess electron by replacing the $V^{+5}$. Possible mechanisms are discussed for the observed Pt doping effect on structural and electrochemical properties of vanadium oxide cathode films, which are grown on I $n_2$ $O_3$: Sn coated glass.