• Journal of Soil and Groundwater Environment
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• v.7 no.2
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• pp.13-22
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• 2002

Soil washing by surfactants is a technology to enhance mobilization and subsequent degradation of oil pollutants by reducing the surface tension of pollutants which is combined with soil. In this study, biosurfactant, rhamnolipid was produced from Pseudomonas aemginosa ATCC 9027 which had an excellent biodegradable activity in soil without causing secondary pollution. Effects of chemical surfactants on the removal of diesel from diesel-contaminated soil were compared to those of biosurfactants including rhamnolipid. Diesel removal efficiency by rhamnolipid extracted from P. aeruginosa culture broth was over 95% in both batch and column washing test in 5,000ppm diesel-contaminated soil with 1% surfactants after washing for 24 hours. On the contrary, the results of chemical surfactants were below 50∼80%, The chemical surfactants with HLB value(8∼15) showed more then 75% efficiency of diesel removal. But, when the HLB values were below 8 or over 15. their efficiency were observed as less then 60% of diesel removal. Rhamnolipid, biologically produced surfactants, may also be promising agent for enhancing diesel removal from contaminated soil.

• Korean Journal of Ichthyology
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• v.27 no.3
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• pp.228-232
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• 2015

The structure of the ventricle in the heart of Hypomesus nipponensis was investigated by light and scanning electron microscope. The heart consisted of four consecutive chambers, the sinus venosus, atrium, ventricle and bulbus arteriosus. The wall of the ventricle was divided into endocardium, myocardium, subepicardium and epicardium. The valves were observed in the artrioventricular and bulboventricular junctions. The ventricular myocardium was an entirely spongy without coronary vessels. The trabecular network was formed with lumina included a central lumen and the trabecula was cylindrical shape. Collagen distribution was apparent in the subepicardium, artrioventricular valve and bulboventricular valve. But in the trabeculae, collagen distribution was observed partly in the base of the ventricle. Especially, the endocardial bridges were observed between trabeculae. These results might be considered that the structure of the ventricle in the heart of pond smelt is adapted to sedentary habit associated with its habitat and lifestyle.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.88-94
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• 2012

In this study, the current-voltage curves for metals were measured using cyclic voltammetry. The relationship between the electrochemical properties and surface states of metals were investigated by Scanning Electron Microscope (SEM). In cyclic voltammetry, we used a 3-electrode system for the electrochemical measurements. The measurement was conducted at the condition that consists of the first reduction from the initial potential to -1350 mV, continuous oxidation to 1650 mV, and last reduction to the initial potential. The scan rates were 50, 100, 150 and 250 mV/s. The results show the C-V characteristics of metals to be for an irreversible process, which was caused by the oxidation current from cyclic voltammogram, when monoethanolamine (MEA) was used as a corrosion inhibitor. When we used MEA as a corrosion inhibitor, the diffusion coefficient was decreased as the concentration of electrolyte was increased. In the SEM images of copper, we observed an increase of surface corrosion at the increased electrolyte concentration. Addition of $1.0{\times}10^{-3}M$ corrosion inhibitor MEA reduced the effect of corrosion prevention due to the relatively large diffusion coefficient at the electrolyte concentration of 0.1N.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.371-375
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• 1988

Tubular ultrafiltration membranes were used to investigated mass transfer characteristics of waste cheese whey. The effects of bulk concentration and flow velocity on permeat flux, mass transfer coefficient and apparent rejection coefficient were measured. Mass transfer coefficient was increased linearly with increasing flow velocity, and following relationship between mass transfer coefficient(k) and linear velocity(u) was obtained. $k=0.87{\times}10^{-5}u^{1-1}$ It is interjecting to note that plots for all linear velocity tend to converge to the same point for zero permeating flux, and the maximum bulk concentration that can be achieved with cheese whey extracts was 38(w/v %). In general, membrane rejection coefficient increased with increasing flow velocity and the rejection coefficients of cheese whey solution and that of lactose in cheese whey solution were obtained $0.40{\sim}0.65$, $0.15{\sim}0.30$, respectively.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.157-168
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• 2006

Spatial detection system such as AVI, GPS, and Beacon etc. can provide spatial travel time only after a vehicle Passes through a road section. In this context, majority of the existing studies on the link travel time estimation area has focused on the arrival time-based link travel time estimation. rather than departure time-based link travel time estimation. Even if some of the researches on this area have developed departure time-based link travel time estimation algorithms, they are limited in that they are not applicable in a real-time mode. The objective of this study is to develop an departure time-based link travel time estimation algorithm which is applicable in a real-tine mode. Firstly, this study discussed the tradeoff between accuracy and timeliness of the departure time-based on-line link travel time estimates. Secondly, this study developed an departure time-based on-line link travel time estimation algorithm which utilizes the Baysian inference logic. It was found that the proposed approach could estimate departure time-based link travel times in a real-time context with an acceptable accuracy and timeliness.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.561-566
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• 1997

Screening, Identification and some cultural characteristics of ALA$({\delta}-aminolevulinic\;acid)$-producing photosynthetic bacteria were carried out for the optimal production of ALA, one of the bioherbicides. Among photosynthetic bacteria isolated from soil, marsh, pond, etc., KK-10 was the best producer of ALA and identified to be Rhodobacter capsulatus belonging to a typical group of nonsulfur purple bacteria. By addition of 15 mM LA (levulinic acid), an inhibitor of ALA dehydrase in cyclic tetrapyrrole biosynthesis, into culture broth at middle log phase of cell growths, ALA production was considerably increased to about 20-fold (28 mg/l). The combined supplementation of glycine and succinate, each with a concentration of 30 mM also enhanced production of ALA and activity of ALA synthase to about 50-fold (73 mg/l) and 2-fold, respectively. The isolated strain was able to produce upto 80 mg/l under the cultural condition optimized by addition 15 mM LA into the synthetic medium at four different points starting middle log phase.

• Applied Microscopy
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• v.38 no.2
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• pp.107-115
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• 2008

The filtration barrier of kidney consists of endothelial cell, glomerular capillary, glomerular basement membrane, mesangial matrix, and podocyte. In aged rats, the morphological changes were shown in various parts, including the glomerulus. These changes were thickening of basement membrane and mesangial matrix, crescent formation of glomerular capillary, deformity of foot processes, glomerular sclerosis and obsolescence. But these glomerular morphologies are partial images or few serial images analysis. In this study, we examined the morphological alteration of glomerulus in the young and aged rats by light microscopy, transmission electron microscopy and three dimensional reconstruction. We were found in aged rat glomerulus, expansion of urinary space and mesangial matrix, thickening and degrading of glomerular basement membrane, decreasing in podocyte foot processes, fragmentation of podocytic nucleus membrane. These observations indicate that may provide useful data for investigating the pathogenesis of age-related dysfunction of kidney.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.21-28
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• 2012

The data centric storage (DCS) scheme is one of representative methods to efficiently store and maintain data generated in wireless sensor networks. In the DCS schemes, each node has the specified data range for storing data. This feature is highly vulnerable to the faults of nodes. In this paper, we propose a new recovery scheme for the lost data caused by the faults of nodes in DCS environments. The proposed scheme improves the accuracy of query results by recovering the lost data using the spatial continuity of physical data. To show the superiority of our proposed scheme, we simulate it in the DCS environments with the faults of nodes. In the result, our proposed scheme improves the accuracy by about 28% through about 2.5% additional energy consumption over the existing scheme.

• Clean Technology
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• v.4 no.1
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• pp.6-23
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• 1998

Recently, semiconductor industry has grown rapidly because of the large demand for electronic devices and equipment. The semiconductor industries have also played an important role on the economic growth in Korea. As the environmental regulations become strict, the proper environmental management and the well-developed waste minimization technologies in semiconductor industries are two of urgent problems to be solved. The semiconductor manufacturing process consists of a series of continuous chemical processes, such as cleaning, oxidation, diffusion, photolithography, etching and film deposition. During the processes, various environmentally hazardous wastes are produced. The wastes may be classified as wastewater, gaseous pollutants, and solid wastes. For waste minimization, the substitution of raw materials and process optimization techniques are used, while the selective destruction technologies of toxic chemicals contained in the wastes have been reported. Also, new technologies have been developed for source reduction and waste reduction, such as reduction of toxic chemical use and substitution of hazardous liquids with gaseous reactants or solvent.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.761-771
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• 2016

This study is significant for its proposed health care quality improvement methods to study the relationship between the medical service quality and customer loyalty in the regional hub public hospital. The subjects were selected 604 people who visited the regional hub public hospital to customers from June 9 to June 30, 2014 as the final survey. The analysis was conducted hierarchical regression analysis to identify factors affecting the reliability factor analysis and customer loyalty. In conclusion showed that accessibility factors affecting customer loyalty, awareness hospital, the perceived value of cost-effectiveness, human services on a significant impact. The regional hub public hospitals by focusing efforts I have a continuity of customer care through constant management in order to provide quality health care, increase the frequency of use and loyalty are needed.