• Analytical Science and Technology
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• v.20 no.4
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• pp.339-346
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• 2007

To search the ninhydrin derivatives that have high chromogenic and fluorogenic properties, molecular holographic quantitative structure property relationship (HQSPR) models on the reactivity between glycine and ninhydrin analogues as latent fingerprint detector were derived and investigated quantitatively. The ${\varepsilon}LUMO$ (e.v.) energy of ninhydrin molecule was an important factor to reactivity of ninhydrin. And, it is suggested that the nucleophilic reaction by orbital-controlled reaction from the frontier molecular orbital (FMO) interaction between glycine and ninhydrin derivatives was more superior than that of electrophilic reaction by charged controlled reaction. The analytical results in atomic contribution maps also shows that the reactivity of ninhydrin was increased by meta-substituents as strong electron withdrawing groups on the benzo ring. Therefore, it is sugested by HQSPR and QSPR model that the 5,6-dinitroninhydrin molecule would increase the reactivity as much as three times as compared to none substituted ninhydrin molecule.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.619-626
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• 2023

Primary and secondary amine-based sorbents were synthesized to investigate the operation capacity for the carbon dioxide separation TSA process. (3-Aminopropyl) triethoxysilane was used as a primary amine precursor as a crosslinking agent to synthesize a secondary amine precursor in which amine groups were crosslinked with a crosslinking agent. Carbon dioxide absorbed by primary amines is completely separated above 170 ℃. The working capacity of the primary amine absorbent was less than 2% when regenerated at 130℃. The secondary amine absorbent has a higher carbon dioxide separation capacity at a lower regeneration temperature than the primary amine absorbent. The secondary amine absorbent could predict process operation performance of about 6.5% with 2% carbon dioxide absorption and 100% carbon dioxide regeneration conditions. Therefore, it was found that the working capacity of the secondary amine absorbent was higher than that of the primary amine.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.309-319
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• 2002

Soil adsorption study was carried out to define the mobility of pesticides or to evaluate leaching potential in soils. Five pesticides including ethoprophos, procymidone, iprobenfos, isoprothiolane, and butachlor were subjected to optimized adsorption experiment protocol for three types of cultivation soils. Freundlich adsorption coefficients (K) were ranged $0.35{\sim}0.95$ for ethoprophos, $0.98{\sim}2.2$ for iprobenfos, $1.2{\sim}4.3$ for procymidone, $1.5{\sim}3.5$ for isoprothiolane and $7.9{\sim}19$ for butachlor in three soils. Based on Koc values, ethoprophos was classified as mobile, iprobenfos, isoprothiolane and procymidone as moderately mobile and butachlor as slightly mobile. Two evaluation methods, Groundwater Ubiquity Score (GUS) index and standard indices of soil-chemical adsorption and biodegradation, were used for the estimation of pesticide leaching potential. Leachability of isoprothiolane and iprobenfos were evaluated as moderate, ethoprophos as a little potential, while butachlor and procymidone showed very low leaching potential. The leaching potential of pesticides was essentially determined on the basis of intrinsic properties of the pesticides and environmental properties. Among the soil properties, organic matter gave a great influence on the leachability of soils. Therefore, leachabilities of pesticides were expected less in loam with relatively higher organic matter than clay loam with lower organic matter.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.157-161
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• 1999

본 연구에서 직물의 열, 수분 전달특성과 KES-FB의 역학적 특성치, 직물표면의 fractal dimension을 측정하여 주관적 의복 착용 쾌적감을 예측하고자 하였다. 실험의복에 사용된 직물은 면 100% 평직물, 면/PET 혼방직물, 피치가공된 면/PET 혼방직물, PET 100% 평직물, 알칼리 감량가공된 PET 100% 크레이프 직물이었으며, 실험의복의 형태는 긴 소매 셔츠로 하였다. 착용실험은 온도 29$\pm$0.5$^{\circ}C$, 상대습도 75$\pm$2%RH, 기류 0.15m/s를 유지하는 항온항습실에서 실시하였고 36명의 여성 피험자(20-23세)들이 참여하였다. 의복 착용감의 하위 구성차원을 파악하기 위해 실험결과를 요인분석한 결과 5 개의 요인으로 추출되었다. 제 1 요인은 체온상승, 수분특성과 관련이 있는 온열.발한감이었으며, 제 2 요인은 무게ㆍ두께감, 제 3 요인은 회복특성감, 제 4 요인은 표면접촉감, 제 5 요인은 온냉감으로 구성되었다. 직물의 표면특성을 정량화하는 방법으로 도입한 fractal dimension 의 분석값들과 종래의 가장 보편적으로 이용되어 온 KES_FB 의 표면 특성치들이 주관적 착용쾌적감 예측에 얼마나 기여하는지 비교해 본 결과, 표면접촉감은 fractal dimension, 접촉점들의 총면적, 접촉점들의 평균 axis ratio, MMD, SMD와 높은 상관을 나타내었다. 또한 종합적 착용쾌적감에 대해서는 SMD 를 제외한 척도들이 유의한 상관을 보였으며, 그 중에서도 fractal dimension 과 접촉점들의 총면적은 0.8 이상의 높은 상관을 나타내었다. 착용쾌적감을 예측하기 위한 회귀분석결과에서는 fractal dimension 만으로 쾌적감의 74%가 설명되었으며 공기 투과도를 첨가하면 두 변수로 $R^2$=.792가 되었다. 설명되는 누적분산값은 67.18%였다.주관적 평가의 결과와 객관적 평가 결과를 이용해 마직물의 태를 평가하는 산출식을 제시하였다. 태 평가치의 경우 16가지 특성치를 모두 넣는 방법과 stepwise 방법, 또 Kawabatark 사용한 순차적 군 회귀법의 세가지 방법의 회귀식 중 16가지 특성치를 모두 넣는 방법의 결정계수가 가장 높았다.tosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Japanese Letter Jobcheso." Therefore, the purpose of this study is to look into the origin of the letter designs in t

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.61-67
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• 2022

The effects of dietary exogenous hydrophilic emulsifiers on the growth, nutrient digestibility, and carcass characteristics of broilers were evaluated. A total of 200 one-day-old broilers (Ross 308) were allotted to one of four treatment groups in a randomized complete block design in five replicates with 10 birds per pen during a 5-week growth experimental period. Birds were fed a corn-soybean meal-based diet with or without the addition of 0.025, 0.050, or 0.075% exogenous hydrophilic emulsifiers. The diets contained 3,025 and 3,075 metabolizable energy/kg for Phases 1 and 2, respectively. For each phase and the overall experimental period, body weight gain (linear, P<0.05) and feed conversion ratio (linear, P<0.05) improved in proportion to the dietary exogenous hydrophilic emulsifier level, while the average daily feed intake was not affected by dietary treatment. Improvement in growth performance by dietary treatments was observed during the last two weeks rather than the first three weeks of the growth phase. In carcass traits, abdominal fat content increased as dietary exogenous hydrophilic emulsifier level increased (linear, P<0.05), whereas dietary emulsifier level did not affect the relative weight of the liver, breast, and leg muscles. In conclusion, addition of dietary exogenous hydrophilic emulsifiers from 0 to 0.075% in broiler diets improved the growth rate and feed efficiency of broilers without any deleterious effects on nutrient digestibility, although a corn-soybean meal-based diet had less energy content (3,025 and 3,075 metabolizable energy/kg) for 0-3 weeks and 3-5 weeks, respectively.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.102-109
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• 1992

There was significant reduction in the mitotic indices of oat roots treated with alachlor. Uniform decrease in prophase, metaphase, anaphase, and telophase as treatment time increasing was observed. Alachlor did not disrupt mitosis, but rather inhibited the onset of mitosis. Labeled dividing cells were significantly inhibited, but the number of labeled interphase cells of all treatment were increased, as compared with control in 8 hr and 12hr period. Labeled dividing cells which entered mitosis thru $G_2$ were inhibited approximately 68% at 8hr after treatment with $1{\times}10^{-5}$ M of alachlor. Alachlor apparently inhibited from the $G_2$stage into mitosis of dividing cells. After 24 hr treatment, 12.1% abd 46.6% inhibition of coleoptile growth occurred at $1{\times}10^{-5}$ M and $1{\times}10^{-4}$ M, respectively. Cell elongation was inhibited by alachlor but was less sensitive than cell division. The longitudinal section cells of oat roots treated with $1{\times}10^{-4}$ M alachlor for 12 hr were observed to be enlarged central cylinder and also showed degradation of apical meristem zone, as compared with the untreated roots.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.25-33
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• 2012

A genetic algorithm (GA) has been employed to optimize the major design variables of the liquid rocket engine. Pressure of the main combustion chamber, nozzle expansion ratio and O/F ratio have been selected as design variables. The target engine has the open gas generator cycle using the LO2/RP-1 propellant. The gas properties of the combustion chamber have been obtained from CEA2 and the mass has been estimated using reference data. The objective function has been set as multi-objective function with the specific impulse and thrust to weight ratio using the weight method. The result shows about 4% improvement of the specific impulse and 23% increase of the thrust to weight ratio. The Pareto frontier line has been also obtained for various thrust requirements.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.4
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• pp.48-55
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• 1994

This study was performed to evaluate the engineering properties of the lightweight concrete using surlightweight aggregate foaming agent and high performance agent. The following conclusions were drawn. 1. The unit weight of type A, B and C concrete was 0.912t/m$^3$, 1.592t/m$^3$ and 1.070t/m$^3$, respectively. Specially, the unit weight of type A concrete was decreased 42% than that of the type B concrete. 2. The highest engineering property was measured in the lightweight concrete using high performance agent Also, the ratio of tensile and bending strength to compresive streng-th of the lightweight concrete was higher than that of the normal cement concrete. 3. The dynamic modulus of elasticity of the lightweight concrete was in the range of 2.86 x 10 5~9.86 x 10 5 kg/cm$^2$ which was approximately 300% than that of the normal cement concrete. 4. The ultrasonic pulse velocity of the lightweight concrete was in the range 2047~3394 n/sec, which was smaller than that of the normal cement concrete.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.99-104
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• 2002

This study deals with the optimal design of a DC reactor type high-Tc superconducting fault current limiter(SFCL). The condition in which the cost function is minimized under given constraints is one of the things to be first considered in developing SFCLS. This condition is a group of the values corresponding to the variables the cost function depends on. In this paper, the length of tape was taken as a dependent variable, the inductance of DC reactor and the turns ratio of magnetic core reactors as independent variables. For the SFCL available at the level of 6.6kV-200A, we examined 4 cases; at the fault times of 80msec, 50msec, 30msec and 10msec. Since thyristors would be utilized instead of diodes, we chose the result at 10msec as the basic data. Considering safety factor 30%, our optimal design was decided to be the inductance 570mH, the critical current over 620A, the turns ratio 0.89 and the fault time within 20msec.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.5
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• pp.425-431
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• 2006

Recently, the government has adjusted the 4th National Master Plan in an effect to achieve balanced national land development. However, the current traffic accident index ranks among the lowest in OECD countries, ranking 25th out of 29 countries. Therefore, this study is aimed at indicating problems with National Expressway and local roads developing a solution by analyzing the problems and suggesting the most appropriate design speed for inter-changes where the traffic accidents occur frequently. With the results, it is to obtain a design speed decision formula at interchange branch points to prevent traffic accidents, secure safe and optimal road conditions and maximize traffic load capability.