• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.655-659
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• 2001

Resident time of the continuous and Instantaneous centrifugal separator using that separates the light and heavy liquids by use of density difference is the orptical factor that affects significantly the chemical metial extraction and the productivity in the chemical and mechanical process. In this paper, the overflow of the device is investigated under consideration of the relationships between inclination angle of liquid feeding screw and the centrifugal force. From the design of the length of a centrifugal separator, the radiuses of rotor and housing, theoretical formulation on the contact radius of separation weir is established through the experiments. From the experiments, it is identified that how much the capacity of inlet impeller and the emulsion phenomenon depend on the screw angle of inlet impeller. Also, we investigate the separation condition and the resident times that are functions of the phase ratio and density.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.5 no.1
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• pp.18-26
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• 1993

The performance of the evaporation facility of low radioactive liquid waste is studied experimentally. The evaporation facility comprises storage pools, feeding pumps, evaporation units with 1,040 sheets of cloth and air handling units. As the results of this study, it is found that the evaporation rate increases as the waste feed rate increases, the relative humidity of induced air decreases, and the air velocity increases. The modified Dalton's evaporation equation derived from experimental data is $E_h=(0.0168+0.0141V){\Delta}H$. The optimum operating conditions of the evaporation facility are waste feed rate of $4.5./hr.m^2$ and air velocity of 1.47m/sec.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.129-135
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• 2008

The 30 tonf-class liquid rocket combustor currently being developed is designed to connect the fuel feeding line at a middle position of the supersonic nozzle in order to reduce both pressure loss in the regenerative cooling passage and overall envelope of the thrust chamber in spite of increase in design complexity. To verify the design of cooling passages including fuel ring, connecting holes, two-directional cooling channels and collectors, numerical analysis has been performed.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.67-74
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• 2019

In this paper, mathematical models of a simulation code are presented. The simulation code was developed for the startup analysis of an open cycle liquid rocket engine (LRE). Most of the components comprising an LRE, including the priming process in the propellant feeding line, were considered. A startup simulation of a 75-tonf LRE, which was used for the KSLV-II test launch vehicle (TLV), was performed. The simulation results showed good agreement with the engine acceptance test results, thus proving the validity of the startup simulation code.

• Journal of ILASS-Korea
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• v.20 no.3
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• pp.168-174
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• 2015

Combustion instability is critical problem in developing liquid rocket engine. There have been many efforts to solve this problem. In this study, the method was sought through the injector as part of these efforts to suppress combustion instability. If the injector can suppress the disturbance coming from the supply line as a kind of buffer it will serve to reduce combustion instability. Especially we target at gas propellant oscillation in gas-centered swirl coaxial injector. The phenomenon is simulated with acoustic excitation of speaker. The film thickness response at injector exit was measured by using a liquid film electrode. Also the response of spray to the disturbance was observed by high-speed photography. Gas-liquid momentum flux ratio and the frequency of feeding gas oscillation were changed to investigate the effect of these experimental parameters. The trend of response by varying these parameters and the cause of weak points was studied to suggest the better design of injector for suppressing combustion instability.

• Applied Biological Chemistry
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• v.19 no.3
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• pp.121-129
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• 1976

A high concentration of myo-Inositol in rat's milk was observed (61-91mg. of myo-Inositol per 100g of milk) by gas-liquid chromatographic method, using a 3% SE-52 column. Feeding experiments showed that approximately 85% of myo-Inositol in milk was from dietary origin: the rest was considered to be synthesized by 1L-myo-Inositol-1-phosphate lyase. Results suggested that the biosynthesis was not sufficiently high to permit the maintenance of its myo-Inositol level in milk. However, study $using(^{14}C)-glucose$ injection into lactating female rats confirmed biosynthesis of myo-Inositol from glucose in mammary gland. This biosynthesis reached a maximum within an hour after $(^{14}C)-glucose$ injection intraperitoneally as lactose biosynthesis did. Study using $(^3H)-myo-Inositol$ confirmed that most of the myo-Inositol in milk was transported from blood plasma myo-Inositol against a concentration gradient. About four hours after the beginning of the injection of $(^{14}C)-glucose$, the specific radioactivity of myo-Inositol in milk was 8% of that of glucose in the blood. When $(^3H)-myo-Inositol$ was injected, the specific radioactivity of myo-Inositol in milk was about 26% of that of blood six hours after injection.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.338-344
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• 2008

The improvement of energy conservation is mandatory to decrease consumption of fossil fuels and to minimize negative impacts on the environment which originates from large cooling and heating demand. The absorption heat pump technology has a large potential for energy-saving in this respect. Absorption heat pump is a means to upgrade waste heat without the addition of extra thermal energy. The higher performance of absorber is of great importance for absorption heat pump cycle. In this study, in order to improve the performance of absorber, the absorber of tangential feed of a liquid phase with spiral tube has been investigated using methanol-glycerine as a working fluid. The spiral tube and tangential feeding generate the turbulence into the liquid flow while increasing the mass and heat transfer coefficients. The simultaneous heat and mass transfer were found to take place in a liquid turbulent film in the absorber with the spiral tube during the process of gas absorption. By calculating mass and heat transfer coefficients by measurement of the concentration and the temperature of each position in the absorber, the entrance was found to be more effective in enhancing mass and heat transfer.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.4
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• pp.108-116
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• 2018

A firing test of the 75 tonf-class liquid rocket engine to be used as the first and second stage engines of the KSLV-II was carried out at the rocket engine test facility(RETF). Since this engine uses liquid oxygen as the oxidizer, which is a cryogenic fluid, it is essential that the chill down of the supply pipe line and engine proceed for the firing test; thus, the given inlet requirements must be met. Moreover, it is important to understand the chill down characteristics of the facility and the engine and the amount of liquid oxygen consumed in the chill down process for efficient test operation in the future. In this paper, chill down characteristics of the supply pipe and the engine were evaluated through the investigation of the chill down process of the 75 tonf-class liquid rocket engine at each stage before and after run tank pressurization. In addition, the amount of liquid oxygen consumed was also evaluated.

• Journal of Life Science
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• v.25 no.7
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• pp.780-785
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• 2015

Dietary intake and bioavailability of phorotannins in abalone was investigated after feeding with the phlorotannin-rich brown seaweed Ecklonia stolonifera after 4 days starvation. Reverse-phase high-performance liquid chromatography (RP-HPLC) affords isolation and quantification of the major phlorotannins of 7-phloroeckol and eckol, which were identified by mass spectrometry and nuclear magnetic resonance. Abalone growth and feed consumption rates were similar when fed either with the E. stolonifera or the common feed seaweed Saccharina japonica for 20 days. Throughout the feeding period, 7-phloroeckolol was accumulated in the abalone flesh tissue up to an average of 0.58±0.13 mg/g dry weight after 6 days. Eckol was reached to 0.25±0.05 mg/g dry tissue after 6 days, and maintained the level until end of feeding period. By feeding S. japonica as a control, no phlorotannins were detected in the abalone tissues. Both of the abalone, fed with E. stolonifera or S. japonica, had enzymes that decomposed 7-phloroeckol and eckol in muscle tissues, with similar degradation rates of −0.05 or less and −0.05 mg/ml/hr, respectively. Phlorotannins were reduced by constitutive enzymes in abalone tissues. Therefore, value-added abalone containing bioactive phlorotannins can be produced by simply changing the feed to the phlorotannin-rich brown seaweed E. stolonifera 6 days before harvest.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.117-123
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• 2003

This paper introduces ground feeding facility for flight test of sounding rocket(KSR-III) which use liquid propellants and addresses facility configuration, development process and results. Supply of propellants and pressurization gases to vehicle according to predefined launch scenario is the primary goal of ground feeding facility. It was constructed at KSR-III launch site, verified by several tests and used for the flight test successfully.