• Journal of Life Science
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• v.20 no.10
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• pp.1563-1568
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• 2010

In the course of a research concerning the molecular mechanism of hypocotyl elongation that occurs during soybean seedling growth in darkness, we have generated a number of ESTs from a cDNA library prepared from the hypocotyls of dark-grown soybean seedlings. Comparison of the ESTs assigned a cDNA clone as a putative plastidic ATP-binding-cassette (ABC) protein homologue. The soybean GmNAP1 protein contains an N-terminal transit peptide which targets it into the chloroplast. The transcription level of the GmNAP1 gene was investigated under continuous red light, continuous far-red light, and complete darkness. The main function of this NAP1 protein is the transport of protoporphyrin IX which is the precursor of chlorophyll from the cytoplasm to the chloroplast. The GmNAP1 gene was transferred into the Arabidopsis under the CaMV 35S promoter. The chlorophyll level of this transgenic Arabidopsis plant was much higher than the chlorophyll level of the wild type Arabidopsis plant.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.59-65
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• 2005

A phosphate recovery system from artificial wastewater was developed using a completely mixed phosphorus crystallization reactor, in which powdered converter slag was used as a seeding crystal. In preliminary test, the optimal pH range for meta-stable hydroxyapatite crystallization for high phosphorus concentration was observed to be 6.0 to 7.0, which was different from the conventionally known pH range (8.0~9.5) for effective crystallization in relatively low phosphorus concentration less than 5 mg/L. The average phosphorus removal efficiency in a lab-scaled completely mixed crystallization system for artificial wastewater with about 100 mg/L of average $PO_4-P$ concentration was shown to be 60.9% for 40 days of lapsed time. XRD analysis exhibited that crystalline of hydroxyapatite formed on the surface of seed crystal, which was also observed in SEM analysis. In EDS mapping analysis, composition mole ratio (=Ca/P) of the crystalline was found to be 1.78, indicating the crystalline on the surface of seed crystal is likely to be hydroxyapatite. Particle size distribution analysis showed that average size of seed crystal increased from $28{\mu}m$ up to $50{\mu}m$, suggesting that phosphorus recycling from wastewater with high phosphorus concentration can be successfully obtained by using the phosphorus crystallization recovery system.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.383-390
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• 2011

In this study, a process combined biofiltration with sulfur-utilizing autotrophic denitrification and membrane separation was proposed to examine the efficiency of nitrogen removal. As an experimental device, hollow-fiber module was installed in the center of reactor to generate the flux forward sulfur layer in the cylinder packed with granular sulfur. In addition, a simple module was installed in activated sludge aeration tank which inside and outside of sulfur-using denitrification module was covered with microfilter and the module was considered as an alternative of clarifier. The experiment for developing new MBR process was carried out for three years totally. As the results of first two-year experiment, successful nitrogen removal performance was revealed with lab-scale test and pliot scale plant using artificial wastewater and actual plating wastewater. In this year, pilot scale test using actual domestic wastewater was performed to prove field applicability. As the results, high-rate nitrogen removal performance was confirmed with about 0.19 kg ${NO_3}^--N/m^3$ day of rate. Also significant fouling and pressure increase were not found during the experiment. And, the production ratio of sulfate and the consumption ratio of alkalinity showed a slightly higher value about 311 mg ${SO_4}^{2-}/L$ and 369 mg $CaCO_3$/L, respectively. In conclusion, the developed MBR process can be utilized as an alternative for retrofiting existing wastewater plants as well as new construction of advanced sewage wastewater treatment plants, with cost-effective merit.

• Journal of the Korean Ceramic Society
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• v.46 no.4
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• pp.392-396
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• 2009

AlON was fabricated by the pressureless reaction sintering of $Al_2O_3$-AlN powder mixtures. The ratio of AlN to $Al_2O_3$ as well as various sintering aids were the main variables for this study. The optimum ratio of AlN in the $Al_2O_3$-AlN mixture was approximately 35.0 mol%. For the sintering aids, only when a small amount of MgO was added together with $Y_2O_3$ and BN, AlON specimens could be sintered to a full density with negligible pores and high transparency. Other combinations of $Y_2O_3$, BN, CaO and MgO resulted in enough pores in the sintered specimens to have in-line transmittance only between 0% and 30%. The in-line transmittance reached over 80% after sintering at $1975^{\circ}C$ for 10 h for the specimen containing 0.15 wt% MgO, 0.08 wt% $Y_2O_3$ and 0.02 wt% BN.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.35-41
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• 1998

This experiment was conducted to find out the effect of artificial light sources(high-pressure sodium lamp, metal halide lamp and fluorescent lamp) on growth of crisphead lettuce(Lactuca sativa L.) in a plant factory. No significant differences in leaf fresh and dry weight were presented among them. Lettuce plants grown under fluorescent lamp showed the lowest growth. Considering the growth of lettuce and efficiency of lamps, it is worth using HPS(high-pressure sodium) lamp in plant factories. The leaves of lettuce plants grown under artificial light sources showed tipburn symptoms at 14th day after transplanting. The beginning of tipburn symptom have been seen on the ninth to tenth leaves from the cotyledons. It is estimated that the occurrence of tipburn was related to rapid growth and K uptake of the lettuce Plants. The Ca, Mg. Cu and Zn elements tended to be accumulated in the nutrient solutions but the T-N, P, Fe and Mn elements keep in balance in them.

• Korean Journal of Community Nutrition
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• v.18 no.6
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• pp.565-576
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• 2013

The purpose of this study was to investigate the effects of nutrition education on nutrition knowledge, dietary attitude and dietary intake of Chinese college students in Korea. The subjects were 64 Chinese college students in Korea (educated group, 32 students vs. non-educated group, 32 students). Educated group was lessoned as group and/or individual. Nutrition education program consisted of four lessons (40min/lesson), '6 major nutrients & function (group lesson)', '6 food group and sources (group lesson)', 'personalized daily needed energy and food exchange units using Food Exchange System (individual lesson)', and 'smart choice of snacks and eating-out foods (group lesson)'. We examined the differences between educated group and non-educated group in nutrition knowledge, dietary attitudes and nutrients intake. After education, there were positive improvements on nutrition knowledge: 'function and foods of 6 nutrients', on dietary attitudes: 'type of breakfast' in educated group. In the evaluation of nutrient intakes according to Dietary Reference Intakes for Korean (KDRI), there were positive improvements on intake levels of riboflavin, fiber, vitamin B6, vitamin C, folate, Ca and K in the educated group. In the index of nutrition quality (INQ), nutrition adequacy ratio (NAR) and mean nutrition adequacy ratio (MAR) were significantly increased in the educated group. In conclusion, it is possible to improve nutrition knowledge, dietary attitude and dietary intake of Chinese college students in Korea through the nutrition education focused on personalized daily needed energy and food exchange units.

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.98-105
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• 2001

Two-monthold silver carps were cultured with seven algal species and zooplankton (Moina macrocopa) in the laboratory. The carps were reared in 10 L translucent cylindrical aquaria with algae and zooplankton for 8 days. The Moina effectively fed almost cultured algae: perfectly removed Cryptomonas (NIES-282) within 60 min. Both algal diets Cryptomonas and Fragilaria (NIES-391) significantly increased the Moina population ($r^2$>0.93, p<0.005), while Microcystis (MIES-90) and Oscillatoria (NIES-204) reduced the zooplankton ($r^2$=0.97, p<001). Fish removed about 50% of all algae for 52 hrs, even 60% of Microcystis still remained: all algae reduced ca. 5${\sim}$12% of initial weight. Furthermore, a continuous supply of algae with same density resulted in the death of fish, e.g. 11 days in cyanobacteria Microcystis. Therefore, the growth limitation of silver carp by algae indicates that zooplankton is of direct dietary contributor in planktivores feeding behavior.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.4
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• pp.293-302
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• 2007

I. Objectives The purpose of this study was to compare the shaping ability between the single length technique performed with Mtwo instruments (VDW, Munich, Germany) and the crown-down technique using K3 (SybronEndo, West Collins, CA, USA) and RaCe (FKG, La Chaux-de-Fonds, Switzerland) instruments. II. Materials & Methods Forty five curved canals in resin blocks were equally divided in to three groups. Group 1 (Mtwo) was instrumented used the full length of canal according to the manufacturer's instructions. The simulated canals was prepared to an instrument size of 35, 0.04 taper canal terminus. In group 2 (Race) and group 3 (K3) was instrumented in a crown-down manner and prepared to an instrument size of 30, 0.06 taper canal terminus. Pre- and post-instrumentation images were scanned and assessment of canal shape was completed with a computer image analysis program. Material removal was measured at 7 measuring points, beginning 1mm from the end point of preparation. Differenced of centering ratio were statistically analyzed using One-way ANOVA followed by Duncan's test. II. Results & Conclusion There was no significant difference on 1, 2, 3 and 7mm measuring point. At 4 and 5 measuring point, significant difference showed between the Mtow instruments and other two instruments. (p<0.05)

• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.146-148
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• 2003

Bayer 공정은 가성소다를 이용하여 보오크사이트로부터 수산화알루미늄을 추출하는 공정이다. 그러나 보오크사이트 추출 후 1차 침전공정에서 반응한 보오크사이트 잔사는 침전시킴으로써 깨끗한 공정액을 분리하는 데 이때 침전되지 못한 다량의 분산성 고형물이 공정액 중에 존재하게 되는데 이를 분산성 보오크사이트(레드머드) 미립자라하며 보통 80-100mg/$\ell$의 농도를 나타낸다. 그러므로 이를 제거하기 위해 다음 공정인 입상여과필터 공정을 사용하는데 이때 필터링 효율증대를 위해 보조제로써 다량의 소석회(Ca(OH)$_2$)를 투여하여 공정액 중의 고형물을 농도를 8-100mg/$\ell$에서 5mg/$\ell$로 낮추는 공정을 사용하고 있다. 특히 국내 수산화알루미능 제조회사일 KC(주)의 경우 소석회 사용량이 일 10톤, 년간 약 3,600톤을 사용함으로써 소석회의 사용량에 따라 같은 량의 슬러지가 발생되게 된다. 따라서 여과후 발생되는 슬러지의 처리비용 문제(연간 9천만원)와 소석회의 미립자에 의한 공정액의 2차 오염과 제품 품질 저하(quality claim) 및 소석회 사용량에 따른 연간 원료비(연간 3억원) 등의 상당한 문제점을 나타내고 있는 실정이다. 아울러 최근 고품위 수산화알루미늄의 공급 요구에 따라 여과시 정제기준이 점차 낮아져 이제는 1mg/$\ell$ 이하를 유지하여야 하는 근본적인 문제에 봉착해있는 실정이다. 그러므로 본 연구에서는 소석회를 사용하는 입상여과법을 대체하기 위한 신공정개발을 추진하였으며, 그동안 카트리지여과법 등의 다양한 실험 결과로부터 최근 필터 보조제를 첨가하지 않는 물리적 여과방법인 세라믹 막 여과법의 적용 가능성을 확인하고 친환경공정인 세라믹 막 여과 실용화 공정 기술을 개발하였다. 세라믹 막 여과 법은 여과 보조제를 사용하지 않으므로 2차적인 슬러지 발생등의 환경문제를 발생하지 않으며, 공정액에 첨가제를 투입하지 않으므로 순환형 친환경공정으로 각광받을 수 있다. 본 연구에서는 고온, 고농도의 NaOH 수용액의 처리에 적합한 막소재와 발생될 수 있는 제반 문제점 등을 파악하였고, 장기간의 실험을 거쳐 최적 투과 압력(Trans membrane pressue), 세정 조건 및 주기, 막재질에 있어서 보강하여야 할 Point, 최적 운전 조건들을 토출해 내었고, 향후 실제 Plant에 적용할 계획이다.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.969-973
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• 1997

In order to produce transglucosylated steviosides continuously, some types of bioreactors were investigated with cyclodextrin glucanotransferase immobilized on a high porous anion exchange resin, Diaion HPA75. Among the bioreactors, the packed-bed reactor (PBR) showed the highest specific productivity. The effect of linear velocity in a PBR on the stevioside conversion was not significant in the range of $10{\sim}60\;cm/hr$ at the same space velocity of $1.2\;hr^(-1)$. When the space velocity of bioreactor was varied from 0.2 to $1.1\;hr^{-1}$, the optimal velocity of substrate solution was determined as $0.7\;hr^(-1)$. The stevioside conversion of more than 70% was maintained during 20 days in the continuous operation, if about 20% of immobilized enzyme was replaced in the top of reactor after two weeks operation as the one of the control methods in bioreactor. The specific production, which refers to as the amount of commercially valuable transglucosylated steviosides produced by a unit amount of immobilized cyclodextrin glucanotransferase, was found to be ca. 150g product/g immobilized enzyme.