• Korean Journal of Health Education and Promotion
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• v.14 no.1
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• pp.63-72
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• 1997

In order to develop the programme for the improvement of dental health among primary school children, epidemiological survey to examine dental caries status was conducted among primary school children in Changwon, Korea. We sampled 2 primary schools and surveyed children from first to sixth grade aged 6-11 years. All samples were 3,206 consisted of 1,715 males and 1,491 females. We assessed caries prevalence on permanent teeth. 1. Children with caries experience on permanent teeth were 15.1% at 1st grade, 48.2% at 2nd grade, 73.8% at 3rd grade, 75.6% at 4th grade, 76.8% at 5th grade, 77.4% at 6th grade. 2. Decayed, Missing and Filled teeth were 0.31 at 1st grade, 1.16 at 2nd grade, 2.12 at 3rd grade, 2.38 at 4th grade, 2.50 at 5th grade, 2.69 at 6th grade. 3. Decayed teeth among Decayed, Missing and Filled teeth were totally 63.4%. Filled teeth among Decayed, Missing and Filled teeth were totally 36.6%. 4. Community dental health programmmes including water fluoridation, fluoride mouth rinsing, use of fluoride-containing toothpastes and fissure sealants should be developed to prevent dental caries among school children. 5. School incremental dental care programme should be also developed to prevent and treat children's dental caries by use of dentists and oral hygienists.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2008.05a
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• pp.1-46
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• 2008

The ability to control filler performance and fines retention is vital in the development of both filled and non filled grades, respectively. This is very important when achieving the desired sheet structure necessary to maximize machine performance and end user demands. A narrow balance exists in attaining the desired retention and formation particularly in systems with heavier ash loads and producing paper and paper board on higher speed high shear equipment. A new generation of both cationic and anionic micropolymer technologies has been developed. These water based chemistries are volatile organic compound (VOC) and alkyphenol ethoxylate (APE) free. When these novel micropolymers are applied with linear poly-acrylamide or in conjunction with inorganic microparticle technologies (such as silica or swellable minerals), substantial increases in drainage, fibre retention and ash retention are observed. These improvements have been observed not only in high filled wood and non wood containing grades such as fine paper and super calendared sheets (SCA), but also in low filled newsprint grades. Of particular note is the drainage improvement seen with the application of the cationic micropolymers in unbleached packaging grades with poly-acrylamide.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.9
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• pp.513-518
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• 2017

In this paper, the removal efficiency of THMs (Trihalomethanes) and DOC (Disolved organic carbon) was compared under different GAC (Granual activated carbon) filling methods. One method is "full filling method" in which column is fully filled with GAC at once and the other is "periodic cumulative method" in which column is partially filled with GAC (10, 20, 33 and 50% of total column volume) and added each ratio during 300 days. The effluent concentration of both THMs and DOC under full filling method was low during the initial period, however, steadily increased with operating time. In the contrast, with periodic cumulative method, it maintained (relatively) evenly during the operating period. Periodic cumulative method was more efficient for removing THMs than full filling method. However, when the ratio of chlorodibromomethane or bromoform among THMs was significantly higher than chloroform and bromodichloromethane, full filling method was more efficient than periodic cumulative method. Full filling method had benefit to total DOC removal and control of average DOC concentration in effluent. Overall, periodic cumulative method is more efficient to equalize the removal efficiency of THMs and DOC, so the more frequent refilling of column with small amount of GAC is more advantageous.

• Journal of the Korean Society of Safety
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• v.21 no.6 s.78
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• pp.46-54
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• 2006

Fire extinguishing experiment was conducted with water mist nozzle in case of the pool fire, cascade fire and spray fire on flammable liquid of class B whether water mist system can be effective system for power transformer fire scenario. In the event of a pool fire, flow rate and time to extinguish was inclined to be increased according to the obstruction rate of ignition space. Furthermore, the performance of fire extinguishing depended upon the spraying angle of the nozzles. In case of cascade fire, the effect of extinguishment was began to show from a combustion pan filled with fuel and fuel flowing plate later on.

• Journal of Power Electronics
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• v.11 no.4
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• pp.612-619
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• 2011

This paper presents a water treatment system for leachate from sewage-filled ground that uses a pulsed-power modulator developed based on semiconductor switches in order to realize a long life, a high repetition rate, and a fast rising time. The specifications of the developed pulsed-power modulator are the pulsed output voltage, the output current, the pulse repetition rate (PRR), the pulse width, and an average output power of $60\;kV_{max}$, $300\;A_{max}$, 3000, $50\;{\mu}s$, and 15 kW, respectively. The pulsed-power water treatment system was introduced and analyzed using an equivalent electrical circuit model to optimize the output voltage waveform. The experimental results verify that the proposed water treatment system can be effectively used for industrial applications.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.421-426
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• 2004

Dry deposition fluxes of inorganic acidic species to the waterbody were measured by the dry deposition sampler (DDS). DDS was composed of three pans filled with pure water. An average concentration increase during the sampling time, after removing an abnormal value if existed, was considered as the input by deposition. Important operation parameters such as the amount of water used and sampling time were determined through a series of laboratory experiments. The deposition flux measured by DDS was compared with that by the water surface sampler developed by Yi et ai. (1997a,b).

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.26 no.3
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• pp.36-53
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• 2013

Objectives : The purpose of this study is to investigate the effects of DOGO phreatic water containing sulphur on Atopic Dermatitis in NC/Nga mouse. Methods : We made DOGO phreatic water removed sulphur using Twin Alternating Sulfate Eater. After making atopic dermatitis caused by sensitizing NC/Nga mouse to DNCB(dinitrochlorobenzene), we made mouse swim in tanks each filled with distilled water, tap water, DOGO phreatic water(contain sulphur), DOGO phreatic water(remove sulphur) for 30minutes everyday. 3weeks later, we analyzed skin clinical score, total IgE levels(by ELISA), WBC differential counting(Neutrophils, Monocytes), absolute cell number of $Neutrophil^+Gr-1^+$, CCR3 mRNA expressions(by Real-time PCR), IL-4, IFN-${\gamma}$ production levels(by ELISA), histologic test(by H&E staining, toluidine blue staining). Results : The results of making NC/Nga mouse induced atopic dermatitis swim in tanks filled with DOGO phreatic water(contain sulphur) are as follows. 1. Skin clinical scores were decreased significantly in comparison to control group. 2. Total IgG levels were decreased significantly in comparison to control group. 3. WBC differential counting(Neutrophils, Monocytes) were decreased significantly in c.mparison to control group. 4. Absolute cell number of $Neutrophil^+Gr-1^+$ were decreased significantly in comparison to control group. 5. CCR3 mRNA expressions were decreased significantly in comparison to control group. 6. IL-4, IFN-${\gamma}$ production levels were decreased significantly in comparison to control group. 7. The epithelial tissue thickness, leucocytes infiltration, erythema, edema, excoriation, scaling, mast cells infiltrations in dorsal skin were decreased in comparison to control group. Conclusions : These results indicate that DOGO phreatic water(contain sulphur) can be used for helping treat atopic dermatitis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.27 no.4
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• pp.141-157
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• 2014

Objectives : The purpose of this study is to investigate the effects of DOGO phreatic water containing germanium on Atopic Dermatitis in NC/Nga mouse. Methods : We made DOGO phreatic water added germanium. After making atopic dermatitis caused by sensitizing NC/Nga mouse to DNCB(dinitrochlorobenzene), we made mouse swim in tanks each filled with distilled water, tap water, DOGO phreatic water, DOGO phreatic water(added germanium) for 30minutes everyday. 3weeks later, we analyzed skin clinical score, total IgE levels(by ELISA), WBC differential counting(Neutrophils, Monocytes), absolute cell number of $Neutrophil^+Gr-1^+$, CCR3 mRNA expressions(by Real-time PCR), IL-4, IFN-${\gamma}$ production levels(by ELISA), histologic test(by H&E staining, toluidine blue staining). Results : The results of making NC/Nga mouse induced atopic dermatitis swim in tanks filled with DOGO phreatic water(contain germanium) are as follows. 1. Skin clinical scores were decreased significantly in comparison to control group. 2. Total IgG levels were decreased significantly in comparison to control group. 3. WBC differential counting(Neutrophils, Monocytes) were decreased significantly in comparison to control group. 4. Absolute cell number of $Neutrophil^+Gr-1^+$ were decreased significantly in comparison to control group. 5. CCR3 mRNA expressions were decreased significantly in comparison to control group. 6. IL-4, IFN-${\gamma}$ production levels were decreased significantly in comparison to control group. 7. The epithelial tissue thickness, leucocytes infiltration, erythema, edema, excoriation, scaling, mast cells infiltrations in dorsal skin were decreased in comparison to control group. Conclusions : These results indicate that DOGO phreatic water(contain germanium) can be used for helping treat atopic dermatitis.

• Environmental Engineering Research
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• v.23 no.2
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• pp.136-142
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• 2018

The river water source of Saidabad Surface Water Treatment Plant at Dhaka, Bangladesh, is deteriorated too much to be treated by conventional treatment process due to excessive ammonia pollution. In order to improve the raw water quality before it enters into the main treatment chain, a pilot study was conducted for pre-treatment of the raw water. The objective is to investigate the rate of reduction of ammonia using the Meteor pilot, a biological pretreatment system, which is a laboratory scale Moving Bed Biofilm Reactor with a nominal volume of hundred liters, filled with 50 L of Meteor 660 media. The reduction of ammonia was quite significant on average 73%, while the reduction of COD was in a range from 20 to 60%. The Meteor pilot was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < $4.0mg\;NH_3-N/L$ when the raw water ammonia concentration was < $15mg\;NH_3-N/L$. The study identified operating parameters necessary to achieve the desired goal of adequate ammonia removal. The study results would benefit a range of systems across the country by providing guidance on the design and operation of a biological pre-treatment system for ammonia removal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.6
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• pp.616-624
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• 2003

The exhaustion of our water resource due to the leakage of waterworks renders it urgent to detect water leakage effectively. In the paper, the detection of water leakage makes use of a pound-penetrating radar(GPR). The region of water leakage is implemented by an acryl box filled with methanol, and then the scale-down experiments are performed by using the GPR system developed in our laboratory. The validity of GPR experiments is assured by showing that the measured data agree well with those finite-difference time-domain(FDTD) simulated results in the same situation. The feasibility of GPR system for the detection of water leakage is investigated by displaying B-scan images according to the distribution of water leakage.