• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.57-63
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• 2015

Absorption characteristics of 2-methylpiperidine (2MPD), 3-methylpiperidine (3MPD) and 4-methylpiperidine (4MPD) absorbents were studied by a vapor-liquid equilibrium (VLE) apparatus and a differential reaction calorimeter (DRC). Using a VLE apparatus, the $CO_2$ loading capacity of each absorbent was estimated. After reaching the absorption equilibrium, nuclear magnetic resonance spectroscopy (NMR) had been conducted to characterize the species distribution of the ($H_2O$-piperidine-$CO_2$) system. Using a DRC, the reaction of heat was confirmed in accordance with the absorption capacity. The unique characteristics of 2MPD, 3MPD and 4MPD absorbents appeared by the position of methyl group. The 2MPD possessing the methyl group at the ortho position showed its hindrance effect during the absorption process; however, piperidine derivatives possessing the meta position and para position did not show its characteristics in $H_2O$-piperidine-$CO_2$ system.

• Korean Journal of Medicinal Crop Science
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• v.6 no.3
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• pp.221-226
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• 1998

This study was conducted to develop labor-saving cultural techniques for weed control using herbicides in Rehmannia glutinosa and Astragalus membranaceus, Napropamide, linuron(preemergence) and paraquat (postemergence) showed significant herbicidal effects. At the same time they did not turn out to be harmful to the growth of Rehmannia glutinosa. The yield of Rehmannia, glutinosa treated with paraquat was higher than that of the untreated. Napropamide showed significant herbicidal effect without harmful effects to the growth of Astragalus membranaceus. Etha1flura1in and metolachlor, however, were s1ightly harmful. The yield of Astragalus membranaceus was highest with napropamide.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.30-35
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• 2000

The experimental study on the lift-off height of diffusion flames was conducted to investigate the damage of swirl-coaxial injector used in $GO_2$/kerosene rocket engine during initial stage of ignition. To investigate the causes of damage and to prevent further damage of the injector, experimental injector was designed and hot fire tests were performed with varying propellant momentum ratio($\frac{Momentum of {GO_2}}{Momentum of Kerosene}$) from 1 to 12. In experimental coaxial injector, kerosene is sprayed from the central nozzle with swirl and $GO_2$ sprayed around the kerosene nozzle in the direction parallel to the axis of combustion chamber. Chamber pressure are close to the atmospheric condition. Lift-off height was measured by still images from camcoder and average values were used as data.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.219-221
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• 1998

This study was carried out to investigate seed bulbs production of 'Namdo' garlic (Allium sativum L.) by treating with 200 mM $K_3PO_4$ and 200 mM $KNO_3$ solution to bulbils. The growth characteristics of garlic plants derived from bulbils sown on 3 different dates were compared to those of plants derived from non-treated bulbils. Time required for 50% shoot emergence ($T_{50}$) was shortened as the sowing dates delayed. However, the final emergence rate was increased in the early sowing dates, and was high when treated with $K_3PO_4$ and sown on Oct. 10. The % clove differentiation of bulb was not significantly affected by sowing date and chemicals treatment of the bulbils. In all treatments, % clove differentiation was greater than 85%. The average bulb weight was increased with earlier sowing. Bulbils treated with $K_3PO_4$ and sown on Oct. 10 exhibited the best growth and yield. which was 27% higher compared to the non-treated bulbils.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.306-314
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• 2002

The purpose of this study is to examine the relation between vegetarian diet and the risk factors of cardiovascular disease. The subjects of the study were 127 Buddhist nuns (age: 23 ~79 yr) for vegetarians and 235 healthy female adults (age: 23 ~79 yr) for non-vegetarians. This study covers food consumption survey, anthropometric measurement, amount of energy expenditure, physical activity and clinical examination. Average body mass index (BMI) of vegetarians and non-vegetarians were 22.47 and 21.08, waist/hip ratio (WHR) was 0.85 and 0.84, percentage of body fat (%BF) was 28.79 and 26.55, respectively. Average duration of vegetarian diet of the vegetarians was 13.16 years. The triglyceride levee of the vegetarians was significantly lower for those who take nutrient tablet compared to those who either take vitamins or who do not take any nutrient supplement. Taking vitamins or nutrient tablet did not give any significant difference in total-cholesterol and LDL-cholesterol for vegetarians, while significantly high triglyceride was observed for the non-vegetarians taking nutrient tablet than the ether non-vegetarians. Taking vitamins or nutrient tablet did not affect the lever of HDL-cholesterol for either vegetarians or non-vegetarians. Athrogenic index (AI) was lower for the vegetarian group tailing nutrient tablet and for the non-vegetarian group not taking vitamins and nutrient tablet, than the other respective groups. Blood sugar of the vegetarians who take nutrient tablet was significantly lower than those tailing vitamins, while blood sugar of the non-vegetarians not taking any nutrient supplement was significantly lower than those taking nutrient tablet.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.264-281
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• 2015

Suicidal ideation has received much attention from both practitioners and researchers as Korean society becomes aging and individualistic. However, previous researches on the suicide ideation have focused on young generations instead of adults who seem to be more suffered from economic pressure and all kinds of exterior environments causing depression. Besides, there were research voids in the suicidal ideation area where depression was never taken into consideration. In this sense, we attempted to launch empirical studies on analyzing explanatory factors relevant to suicidal ideation in all the age groups by using KNHANES dataset from 2008~2012 years. Especially, we further analyzed KNHANES dataset to know how much depression affects suicidal ideation. Empirical results showed that depression is in a significant relationship with the suicidal ideation in all the demographic dimensions such as age, education, living area, etc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.1
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• pp.55-62
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• 2000

In this paper, cellularphone antenna was designed to be capable of being mounted on the circuit-board with co-planar feeding method. The designed antenna is fabricated by the following procedure : make the multi-layered dielectric ceramic($\varepsilon_{\tau}$=23) hexahedron($7.5mm\times4.5mm\times0.4mm$) and then produce λ/4 monopole radiation element with helical structure on the surface of the hexahedron. The results are as followings : Returnloss 27.36 dB, -10 dB bandwidth 76 MHz(3.97 %), H-plane average gain -9.43 dBd.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.357-364
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• 1997

The objective of this study was to find optimum nonionic surfactants for clean up of soils contaminated by hydrocarbon oils. PIT(phase inversion temperature) measurements in ternary systems containing pure hydrocarbons, pure nonionic surfactants, and water were carried out and interfacial tensions were measured as a function of time for n-hexadecane oil drops brought into contact with various mixtures of nonionic surfactant and water. Batch surfactant washing experiments were performed based on the measurement, results of PIT and interfacial tension and the results showed that maximum removal of n-hexadecane occurred at the PIT of the system. For the $C_{12}E_5(C_{12}H_{25}O(CH_2CH_2O)_5H)$ system, maximum n-hexadecane removal of 73.4% occurred at the PIT of $52^{\circ}C$. In contrast, n-hexadecane removal at $25^{\circ}C$ and at $60^{\circ}C$, each corresponding to the conditions of below PIT and above PIT of the system, was found to be 57.1% and 57.0% respectively. The maximum removal of a hydrocarbon at the PIT of a system, where the hydrophilic and hydrophobic properties are balanced, was found to be due to the existence of high oil solubilization into a middle-phase microemulsion and ultralow interfacial of the order of $10^{-2}$ to $10^{-3}$ dyne/cm between middle-phase microemulsion and excess oil phase.

• Proceedings of the Korea Water Resources Association Conference
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• 2002.02a
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• pp.309-324
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• 2002

국내의 경우 관개용수의 대부분은 벼생육을 위한 논의 관개응수로 사용되고있다. 농업용수 이용은 약 150억㎥/year, 이는 하천유지수량을 제외한 전체 물이용량 237억㎥/year의 약 63%에 해당한다. 최근 물절약은 가장 중요한 사회, 경제적인 이슈 중의 하나로 인식되고 있다. 그러나, 국내의 경우 관개효율은 여전히 낮아 약 35%의 관개용수가 손실되는 것으로 추정되고있다. 비록 관개에서의 물절약이 시급한 문제이기는 하지만 용수손실 원인에 따른 손실량에 대한 정량적인 연구가 행해지지 않았었다. 손실 원인에 따른 손실량을 계측하기 위한 시험지구로 경기 평택의 이동지구를 선정하였다. 시험지구의 주수원공으로는 유역면적 9,440ha, 관개면적 2,027ha인 이동저수지이며 상류유역에 미산 및 용덕저수지가 위치하고 관개지구내에 원암 및 은산양수장이 있다. 시험지구의 계측시설은 강우량 계측을 위하여 자기강우계를 설치하였고 저수위, 하천수위 및 응배수로의 수위 측정을 위하여 수위계를 설치하였다. 강우계는 4개소에 설치되었으며 수위계는 26개소에 설치되었다 강우계는 지구내의 저수지 및 양수장 관리사 부근 4개소에 전도형 자기우량계를 설치하였다. 수위계 26개소 중에서 저수지의 저수위 계측지점이 3개소이며 하천수위 계측지점이 2개소 그리고 용배수로의 간선수로 시점부와 간지선 분기점 등의 주요지점에 21개소의 계측지점이 있다. 모든 계측지점의 계측기에는 자체 혹은 별도의 자료저장용 데이터로거가 부착되어 현장 계측자료를 저장하도록 설치 되어있다. 강우계는 전도형강우계(tipping bucket type)이며 수위계는 계측지점의 특징에 따라 여러종류의 수위계측기가 설치되었다 예를들어 초음파수위계(ultrasonic-wave type), 부표식수위계(float type) 그리고 압력식수위계(Pressure type)가 설치되어 있다. 현장 계측기의 전원은 한국전력 전원 혹은 태양전지 및 축전지를 사용하였다. 수위계측지점의 유량을 환산하기 위하여 계측지점의 단면조사와 유속측정을 통해서 수위-유량관계(rating curve)를 규명하였다. 시험지구의 관개효율 및 용수손실 규명 등에 관한 기본자료를 수집하기 위해서는 계측시스템의 운영은 장기간으로 지속 되어야 한다

• Journal of Nutrition and Health
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• v.48 no.6
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• pp.496-506
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• 2015

Purpose: The purpose of this study was to estimate dietary flavonoids intake of Korean adolescents. Methods: Using data from the 2007-2012 Korean National Health and Nutrition Examination Survey, a total of 3,957 subjects aged 12-18 were included in this study. We estimated individual daily intake of total flavonoid and six flavonoid classes including flavonols, flavones, flavanones, flavan-3-ols, anthocyanidins, and isoflavones by linking food consumption data with the flavonoids in the commonly consumed food database. The distribution of sociodemographic, health-related, and dietary factors according to flavonoids intake was examined. Results: Average dietary flavonoids intake of the study subjects was 195.6 mg/d in girls, and 189.4 mg/d in boys. The highest flavonoids intake group consumed significantly more fiber, vitamin C, legumes, fruits, and vegetables (p < 0.01) and less fat, grains, meats and dairy foods than other lower consumption groups (p < 0.001). Dietary flavonoid intake showed negative correlation with waist circumference and systolic blood pressure (p < 0.05). Conclusion: This study provided basic data for estimation of flavonoids intake of Korean adolescents. Further research will be required for analysis of the association of flavonoids intake and health-related factors such as cardiovascular risk factors.