• Membrane Journal
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• v.13 no.3
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• pp.143-153
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• 2003

The effects of bipolar interface formed on the surface of cation-exchange membrane on water splitting phenomena were investigated. Results showed that the formation of immobilized bipolar interface resulted in significant water splitting during electrodialysis. In particular, the immobilized bipolar interface was easily created on the cation-exchange membrane surface in the electrodialytic systems where multivalent cations served as an electrolyte. Multivalent cations with low solubility product resulted in violent water splitting because they were easily precipitated on the membrane surface in hydroxide form. Therefore, the bipolar interface consisting of H- and OH-affinity groups were formed on the membrane-solution interface. Apparently, water splitting was largely activated with the help of strong electric fields generated between the metal hydroxide layer and fixed charge groups on the membrane surface. Likewise, the accumulation of large molecular counter ions on the membrane surface led to the formation of a fixed bipolar structure that could cause significant water splitting in the over-limiting current region. Therefore, the prevention of the immobilization of bipolar interface on the membrane surface is very essential in improving the process efficiency in a high-current operation.

• Geomechanics and Engineering
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• v.12 no.5
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• pp.753-770
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• 2017

The coagulation or flocculation of cohesive clay suspensions is one of the most widely used treatment technologies for contaminated water. Flocculated clay can transport pollutants and nutrients in ground water. Coagulants are used to accelerate these mechanisms. However, existing coagulants (e.g., polyacrylamide, polyaluminum chloride) are known to have harmful effects in the environment and on human health. As an alternative, eco-friendly coagulant, this study suggests ${\varepsilon}-polylysine$, a cationic biopolymer fermented by Streptomyces. A series of sedimentation experiments for various ${\varepsilon}-polylysine$ concentrations were performed, and the efficiency of sedimentation with ${\varepsilon}-polylysine$ was estimated by microscopic observation and light absorbance measurements. Two types of sedimentation were observed in the experiments: accumulation sedimentation (at 0.15%, 0.20%, 0.25% ${\varepsilon}-polylysine$) and flocculation sedimentation (at 0%, 0.1%, 0.5%, 1.0%, 2.0% ${\varepsilon}-polylysine$). These sedimentation types occur as a result of the concentration of counter ions. Additionally, the performance of ${\varepsilon}-polylysine$ was compared with that of a previously used environmentally friendly coagulant, chitosan. The obtained results indicate that flocculation sedimentation is appropriate for contamination removal and that ${\varepsilon}-polylysine$ functions more efficiently for clay removal than chitosan. From the experiments and analysis, this paper finds that polylysine is an alternative eco-friendly coagulant for removing chemical contaminants in groundwater.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.110-113
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• 2001

In controlling chronic intractable pains, the current therapeutic methods used are exercise, over the counter medication, cognitive-behavioral therapy, opioid medication, neural blockade, operation, etc., spinal cord stimulation being the last resort. Spinal cord stimulation was initiated when Shearly and others clinically tested the Gate control theory of Melzack and Wall. This had triggered the advancement of theoretic research on the mechanism and hardware necessary and has resulted in an accumulation of clinical experiences. This is known to be effective for treating sympathetic pain, arachnoiditis, failed back pain syndrome, radiculopathy, peripheral vascular disease, phantom limb syndrome, post-herpetic neuralgia, peripheral neuropathy, and angina pectoris. This report describes our experience in experimental spinal cord stimulation in patients with simultaneous post-herpetic neuralgia and herniated intervertebral disc. There wasn't any improvement in the post-herpetic neuralgia but the symptoms of a herniated intervertebral disc was much ameliorated. This was quite an unexpected result. The patient's back pain returned when the stimulation stopped.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.357-371
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• 1996

Lithium (Li) is known to be used not only during acute manic psychosis but also acute depressive phase in manic-depression. In the present study, it was attempted to investigate the effect of lithium on catecholamine (CA) secretion from the isolated perfused rat adrenal gland and to clarify the mechanism of its action. Replacement of $Na^+$ (118.4 mM) by lithium in the normal Krebs-bicarbonate solution used to perfuse the gland produced gradually an increased response in the spontaneous catecholamine release, which was peaked at $30{\sim}60$ min after its perfusion. Li-Krebs solution was perfused into an adrenal vein for 2 hours in every experiments. Li-Krebs-evoked CA secretory responses were depressed significantly under loading with $Ca^{++}-free$ medium. This CA secretion evoked by lithium loading was also reduced markedly by the pretreatment with nicardipine ($10^{-6}$ M), TMB-8 ($10^{-5}$ M) and chlorisondamine ($10^{-6}$ M) for 20 min, respectively, while was not affected by preloading with a pirenzepine ($2{\times}10^{-6}$ M)-containing Krebs. $Na^+$ pump inhibition by pretreatment with ouabain ($10^{-4}$ M) for 20 min did make the marked depression in Li-evoked CA secretory responses. Moreover, Li-evoked CA release was also diminished markedly by preloading with tetrodotoxin ($5{\times}10^{-7}$ M)-contaming Krebs for 20 min. All these experimental results taken together suggest that lithium enhances CA secretion in a $Ca^{++}$-dependent fashion by its accumulation in the adrenomedullary chromaffin cells of the rat, and that this secretory effect may be meidated by a dual mechanism: (i) chromaffin cell depolarization and subsequent opening of voltage-sensitive $Ca^{++}$ channels and (ii) activation of a $[Li]_i-[Ca]_0$ counter-transport system.

• Journal of Korean Home Economics Education Association
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• v.10 no.2
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• pp.131-144
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• 1998

The lack of characteristical understanding of the Home Economics Education will have difficulty in achieving the goal of the Home Economics Education. To allow the Home Economics Education class in school contribute toward the enhancement of the quality of life, it is inevitable to reinforce the recognition of the importance and necessity of the Home Economics Education and to newly propose a directional guidance forward the coming 21st century. The purpose of this study was to provide basic data for planners of the future Home Economics Education by surveying research administrators in charge of programming the overall school curriculum. This study was conducted under the following procedure to have the outcome as follows ; 1. Answers from respondents of age over 50 or careers over 16 years tended to grasp the goal of Home Economics Education in relation to the enhancement of quality of life rather than to the accumulation of knowledge, skill or capacity. 2. Of all the surveyed, 9.64% regarded Home Economics Education as an essential part of school education and the positive ratio was higher with younger respondents. 3. To the question asking if the high school Home Economics Education could have influence on one's capacity, 97.2% of the answerers said yes. The respondents with career under 15 year showed 100% of positive agreement in this matter and of age under 40 marked much higher ratio of 98.84% than the elders. 4. The overall recognition of the necessity for separate sections in Home Economics Education programmed in accordance with the 6th Revision of High School Curriculum displayed a considerably high ratio, with a little differences among age and job groups. The purpose of this study is to analyze and understand adolescents'culture, thereby to provide fundamental information for Preventive Education for Adolescents'Problems in Home Economic Education. 745 articles collected in computer communication service were used for the analysis. The data were analyzed by frequency and percentage using the SPSS/PC+computer program. The most important results of this study were as follows ; 1) Concerning 'Adolescent's Problems's, problems such as violence, homicide and robbery were treated with the greatest frequency. It was also analyzed that the older generations are highly inclined to understand adolescents'culture as a negative one, for example, 'delinquency'or 'immaturity'. 2) Although the area of 'Adolescents'Education'was treated most frequently reflecting the high educational concern in our society, the significant part of those articles were on wrongful educational administration. As much as 70.6% of the articles analyzed were on 'Education'and 'Problems'. Thereby it may be concluded that the other areas such as health, activities, worries, values and harmful environments ere treated respectively as only a 'subculture'or'fragmentary culture'. The articles containing correlations and interactions among them and certain alternative proposals were very rare. 3) The areas such as 'Worries and Counselling'and 'Health'were occupying only a small portion of the articles. The articles which were treating the practical worries and their resolutions were even rarer. 4) 'Values'of the adolescents tended to be viewed by the older generations very negatively. It was also found that the older generations gave the tendency to see the 'consumption culture'of the adolescents as a kind of 'counter culture'or'subculture'.

• Journal of the Korean earth science society
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• v.33 no.3
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• pp.259-268
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• 2012

To investigate the fluctuation of marine aerosol number concentration at each different size with vertical winds in ocean area, aerosol particles and vertical wind components were measured in the Ieodo Ocean Research Station, which is located to 419 km southwest of Marado, the southernmost island of Korea, from 8 to 22 June 2009. The Laser Particle Counter (LPC) and ultrasonic anemometer were used to measure the number of aerosol particles and vertical wind speed. Surface weather chart, NCEP/NCAR reanalysis data and sounding data were used to analyze the synoptic condition. The distribution of aerosol number concentration had a large fluctuation of bigger particles more than 1.0 ${\mu}m$ in diameter by vertical wind speed during precipitation. The aerosol particles larger than 1.0 ${\mu}m$ in diameter increased as the wind changed from downward to upward during precipitation. The aerosol number concentration of bigger size than 1.0 ${\mu}m$ in diameter increased about 5 times when vertical velocity was about 0.4 $ms^{-1}$. In addition, the accumulation and coarse mode aerosol number concentration decreased about 45% and 92%, respectively compared to concentrations during precipitation period. It is considered that vertical wind plays an important role for the increasing of coarse mode aerosol number concentration compared to the large aerosol particles sufficiently removed by the scavenging effect of horizontal winds. Therefore, the upward vertical winds highly contribute to the formation and increase in aerosol number concentration below oceanic boundary layer.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.424-429
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• 2010

To solve the problems with excessive accumulation of soil inorganic N and resulting saline soils from overuse of nitrogen fertilizer, the effect of sucrose application on decrease of soil inorganic N content and electrical conductivity (EC) was studied. Sucrose treatment greatly reduced ${NH_4}^+$-N content in soil. The amount of reduction was greater as the amount of sucrose treatment was increased. When ${NH_4}^+$-N content was reached the lowest point (about 10 mg $kg^{-1}$or lower), the C/N ratio, which determines the amount of sucrose treatment, was around 10 regardless of initial ${NH_4}^+$-N content. For the rate of ${NH_4}^+$-N reduction 15~36 hours was required to reduce the initial ${NH_4}^+$-N content to half, and 36~69 hours to lower ${NH_4}^+$-N content to the lowest point (about 10 mg $kg^{-1}$or lower). In addition, sucrose treatment greatly lowered ${NO_3}^-$-N content. In case of C/N ratio above 10, initial ${NO_3}^-$-N content of 348 mg $kg^{-1}$ was reduced to the lowest of 14~21 mg $kg^{-1}$. As for the rate of ${NO_3}^-$-N reduction by sucrose treatment, it took 36~60 hours for ${NO_3}^-$-N content to reach the lowest point for C/N ratio of 10 or higher, and it took 3 weeks, comparably longer time, for C/N ratio of 5. Lowering soil EC from sucrose treatment showed the same trend as ${NO_3}^-$-N content. As an important energy and carbon source for humankind, sugar should not be wasted and must be carefully applied to soil. In principle, the best way of preventing salt accumulation in soil is to optimize the fertilizer input. However, when over-fertilization should be dealt with, the sucrose treatment would be a possible and effective counter-measure to reduce overdosed nitrogen sources in soil.

• KDI Journal of Economic Policy
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• v.13 no.2
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• pp.97-127
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• 1991

This paper investigates the roles and the limitations of the Korean antitrust agencies-the Office of Fair Trade (OFT) and the Fair Trade Commission (FTC) during the making of the major industrial policies of the 1980's. The Korean antitrust agencies played only a minimal role in three major industrial policy-making issues in the 1980's- the enactment of the Industrial Development Act (IDA), the Industrial Rationalization Measures according to the IDA, and the Industrial Readjustment Measures on Consolidation of Large Insolvent Enterprises based on the revised Tax Exemption and Reduction Control Act. As causes for this performance bias in the Korean antitrust system, this paper considers five factors according to the current literature on implementation failure: ambiguous and insufficient statutory provisions of the Monopoly Regulation and Fair Trade Act (MRFTA); lack of resources; biased attitudes and motivations of the staff of the OFT and the FTC; bureaucratic incapability; and widespread misunderstanding about the roles and functions of the antitrust system in Korea. Among these five factors, bureaucratic incompetence and lack of understanding in various policy implementation environments about the roles and functions of the antitrust system have been regarded as the most important ones. Most staff members did not have enough educational training during their school years to engage in antitrust and fair trade policy-making. Furthermore, the high rate of staff turnover due to a mandatory personnel transfer system has prohibited the accumulation of knowledge and skills required for pursuing complicated structural antitrust enforcement. The limited capability of the OFT has put the agency in a disadvantaged position in negotiating with other economic ministries. The OFT has not provided plausible counter-arguments based on sound economic theories against other economic ministries' intensive market interventions in the name of rationalization and readjustment of industries. If the staff members of antitrust agencies have lacked substantive understanding of the antitrust and fair trade policy, the rest of government agencies must have had serious problems in understanding the correst roles and functions of the antitrust system. The policy environment of the Korean antitrust system, including other economic ministries, the Deputy Prime Minister, and President Chun, have tended to conceptualize the OFT more as an agency aiming only at fair trade policy and less as an agency that should enforce structural monopoly regulation as well. Based on this assessment of the performance of the Korean antitrust system, this paper evaluate current reform proposals for the MRFT A. The inclusion of the regulation of conglomerate mergers and of business divestiture orders may be a desirable revision, giving the MRFTA more complete provisions. However, given deficient staff experties and the unfavorable policy environments, it would be too optimistic and naive to expect that the inclusion of these provisions alone could improve the performance of the Korean antitrust system. In its conclusion, this paper suggests several policy recommendations for the Korean antitrust system, which would secure the stable development and accumulation of antitrust expertise for its staff members and enough understanding and conformity from its environments about its antitrust goals and functions.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.294-302
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• 2000

Purpose: To investigate the mechanisms related to F-18-FDG uptake by tumors, F-18-FDG accumulation was compared with glucose transporter-1 (Glut-1) expression and hexokinase activity in various human cancer cell lines. Materials and Methods: Human colon cancer (SNU-C2A, SNU-C4, SNU-C5), hepatocellular carcinoma (SNU-387, SNU-423, SNU-449), lung cancer (NCI-H522, NCI-H358, NCI-H1299), uterine cervical cancer (HeLa, HeLa 229, HeLa S3) and brain tumor (A172, Hs 683) cell lines were used. After 24 hr incubation of $5{\times}10^5$ cells, 37 kBq F-18-FDG was added and the uptake by cells at 10 min was measured using a gamma counter. Hexokinase activity was measured by continuous spectrophotometric rate determination. To measure mitochondrial hexokinase activity, mitochondrial fraction was separated by a high speed centrifuge. Immunohistochemical staining of Glut-1 was performed, and graded as 0, 1, 2, or 3 according to expression. Results: There was difference among F-18-FDG uptake, total and mitochondrial hexokinase activity, and Glut-1 expression with different cancer cell lines. The correlations of F-18-FDG with total hexokinase and mitochondrial hexokinase activity were low (r=0.27 and 0.26, respectively). Glut-1 expression showed a good correlation with F-18-FDG uptake (p=0.81, p=0.0015). Previously, we reported no correlation of F-18-FDG uptake with hexokinase activity in colon cancer cell lines. Thus, when colon cancer cells were excluded, F-18-FDG uptake showed higher correlation with total hexokinase and mitochondrial hexokinase activity (r=0.81, p=0.0027 and r=0.81, p=0.0049, respectively). Conclusion: Both Glut-1 expression and hexokinase activity were contributing factors related to F-18-FDG accumulation in human cancer cell lines. The relative contribution of Glut-1 expression and hexokinase activity, however, was different among different cancer cell types.