• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.120-127
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• 2007

The objective of this research was to evaluate the ability of water and ethanol extracts from mulberry fruit (Morus alba L.) to influence the inhibitory activity of angiotensin converting enzyme (ACE) and xanthine oxidase(XOase). The total phenol contents and sixteen phenolic compounds were investigated in water and ethanol extracts. In order to understand the factors responsible for the potent antioxidant and antihypertensive ability of mulberry, it has been evaluated for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the 1,1-diphenyl-2-picryl hydrazyl free radical generating system. The total phenol contents and total of phenolic compounds in ethanol extract showed higher levels than water extract in mulberry fruit six phenolic compounds (chlorogenic acid, narigin, syringic acid, quercetin, naringenin, kampferol) has a higher individual phenolic compound content in the 60% ethanol extraction than 80% ethanol extract. The inhibitory activity on angiotensin converting enzyme (ACE) were highest in 80% ethanol extract (9.0%). Also, activity of xanthine oxidase(XOase) inhibition appeared highest in 80% ethanol extracts and correlated well with the total phenolic content, which was modulated by the concentration of individual phenolic compounds. This result revealed, that strong biological activity was caused by specific phenol compound contents. Utilization of water and ethanol extracts from mulberry fruit are expected to be good candidate for development into source of free radical scavengers and anti-hypertentive activity

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4_1
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• pp.137-150
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• 1992

A complete solution, exact to second-order, for wave motion forced by a hinged-wavemaker of variable-draft is presented. A solution for a piston type wavemaker is also obtained as a special case of a hinged-wavemaker. The laboratory waves generated by a plane wave board are shown to be composed of two components; viz., a Stokes second-order wave and a second-harnomic free wave which travels at a different speed. The amplitude of the second-harmonic free wave is relatively large in shallow water and decreases to less than 10% of the amplitude of the primary wave in deep water. Wavemakers with relatively deeper draft (i.e., hinged near the bottom) generate the free waves of smaller amplitude in shallow and intermediate water depths than the wavemakers with shallow draft. However, the opposite is predicted by theory in deep water.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.77-81
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• 2010

This study carried out hydraulic model test for water circulation system in Cheongna district as part of Incheon Free Economic Zone. Canal way project of Cheongna was planned to establish for environment-friendly water circulation system, improve quality of life and diversification of traffic through using boat as a water-friendly international business city. The navigation canal, There are two intake facility in central park and it can purify water 15,000$m^3$ per day. After purify, water move to 8 facility of water culture area which supplies water in canal way. This process called water circulation system in cheongna. Also, there are several flow induction machine in canal way except south-north way. Therefore, this study will verify about validity of water circulation system's safety through hydraulic model test.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.2
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• pp.65-72
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• 2001

In order to improve the performance of a free power turbine type gas turbine engine by injecting the atomized water into a compressor inlet., a study on Moisture Air Turbine (MAT) cycle was proposed. Compressor work by air-water mixtures in phase change was theoretically considered, and it was found that the water evaporation might reduce the compressor work. Cycle model calculations predicted that power increments of 16.2%, 14.9% and 12.6% by 1.0% water to the air flow rate at the compressor intake with rotational shaft speeds of 1000, 1210, 1350 rps were obtained, and also thermal efficiency due to the reduction of compressor work was improved.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.303-307
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• 2001

Operation conditions to maximize the hydrolysis of beef tallow was investigated by using the response surface method. In the response surface analysis, reaction temperature, pressure, and ratio of fat to water was considered as independent variables. The concentrations of triglycerides. diglycerides, monoglycerides and free fatty acids were considered as dependent. variables. The optimum conditions for the hydrolysis was as follows' the reaction temperature was $271^{\circ}C$, pressure 86 bar and ratio of fat to water was 106.08g / 133.93 g. The maximum concentration of free fatty acids was 96.49 % at these optimum conditions.

• Bulletin of the Society of Naval Architects of Korea
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• v.14 no.3
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• pp.13-22
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• 1977

The hydrodynamic forces acting on a forced oscillating 2-dimensional cylinder on a free surface of a fluid of a finite depth are calculated by distributing singularities on the immersed body surface. And the Haskind-Newman relation in a fluid of a finite depth is derived. The wave exciting force of the cylinder to an oscillation is also calculated by using the above relation. The method is applied to a circular cylinder swaying in a water of finite depth, and then, to a rectangular cylinder heaving, swaying, and rolling. The results of above cases give a good agreement with those by earlier investigators such as Bai, Keil, and Yeung. Also, this method is applied to a Lewis form cylinder with a half beam-to-draft ratio of 1.0 and a sectional area coefficient of 0.941, and to a bulbous section cylinder which is hard to represent by a mapping function. The results reveal that the hydrodynamic forces in heave increase as the depth of a water decrease, but in sway or roll, the tendency of the hydrodynamic forces is difficult to say in a few words. The exciting force to heave for a bulbous section cylinder becomes zero at two frequencies. The added mass moment of inertia for roll is seemed to mainly depend on the sectional shape than the water depth.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.54-58
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• 2001

In order to Improve the performance of a free power turbine type gas turbine engine by injecting the atomized water into a compressor inlet., a study on Moisture Air Turbine (MAT) cycle was proposed. Compressor work by air-water mixtures in phase change was theoretically considered, and it was found that the water evaporation might reduce the compressor work. Cycle model calculations predicted that power increments of 21.7%, 20.2% and 18.4% by 1.5% water to the air flow rate at the compressor intake with rotational shaft speeds of 1000, 1210, 1350 rps were obtained, and also thermal efficiency due to the reduction of compressor work was improved.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.152-157
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• 2000

In order to select the optimum drying method for the production of cinnamon extract, water extract and 70% ethanol extract of cinnamon were prepared. And then several drying method of oven drying, vacuum evaporation, spray drying and freeze drying were performed. Content of cinnamic acid, cinnamic aldehyde, eugenol, tannin and free sugar, and antioxidant activity, degree of browning, pH, color value, turbity and solubility were compared. In water extract, contents of cinnamic acid, cinnamic aldehyde, eugenol were 29.45mg/100g, 94.86mg/100g, 120.75mg/100g and decreased to 4.76%∼44.21%, 5.30%∼48.05%, 3.66%∼21.83% by oven dyring, vaccum drying, spray drying respectively, but freeze drying showed a little decrease of those components. In 70% ethanol extract, effectual components decreased to 76.05%∼88.38% and 26.86%∼78.76% by freeze drying and vacuum evaporation respectively. Antioxidant activity decreased by drying and decreasing rate in 70% ethanol extract was lower than water extract. Degree of browning increased as the drying temperature increased. Tannin and free sugars were little affected by drying temperature. Solubility decreased in oven drying and 70% ethanol extract. Overall data suggested that optimum drying methods of cinnamon extract were freeze drying in case of water extract and freeze drying and vaccum drying in case of 70% ethanol extract.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.503-510
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• 2011

Ammonia in water which is toxic to human, its concentration is regulated below 0.5 mg/L in drinking water. Current study aimed to develop appropriate models for ammonia stripping using hollow fiber membrane contactor. Two different models were developed during the study. Model 1 was assumed only free ammonia ($NH_3$) transfer in stripping process, whereas the Model 2 was assumed with total ammonia ($NH_3+{NH_4}^+$) transfer. Ammonium chloride ($NH_4CI$), sodium hydroxide(NaOH) were used to make ammonia solution, which was concentration of 25 mg as N/L at a pH of 10.5. The experimental conditions were such that, the liquid flow was in tube-side in upward direction and t he gas flow was on shell-side in downward direction a t room temperature. The experimental and modeling results showed that marginal difference were observed at low gas flux. However the difference between the both models and experimental value were increased when the gas flux was increased. The study concludes that the Model 1 with free ammonia is more appropriate when both models were compared and useful in ammonia stripping process at low gas flux.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.151-155
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• 2015

The molecular interactions between the nucleic acid bases and water molecules are important in organism. Despite Adenine-Thymine Hoogsteen base pair and Guanine-Cytosine Watson-Crick base pair have been demonstrated to be most stable in a gas phase, the effect of water on the stability of these base pairs remains elusive. Here we report the structural and thermodynamic characteristics on possible Adenine-Thymine and Guanine-Cytosine base pairs in a gas phase as well as in an aqueous phase by using quantum mechanical method and statistical mechanical calculations. First, we optimized the direct base-pair interaction energies of four Adenine-Thymine base pairs (Hoogsteen base pair, reverse Hoogsteen base pair, Watson-Crick base pair, and reverse Watson-Crick base pair) and three Guanine-Cytosine base pairs (GC1 base pair, GC2 base pair, and Watson Crick base pair) in a gas phase at the $B3LYP/6-31+G^{**}$ level. Then, the effect of solvent was quantified by the electronic reorganization energy and the solvation free energy by statistical mechanical calculations. Thereby, we discuss the effect of water on the stability of Adenine-Thymine and Guanine-Cytosine base pairs, and argue why Adenine-Thymine Watson-Crick base pair and Guanine-Cytosine Watson-Crick base pair are most stable in an aqueous environment.