• KIEAE Journal
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• 제12권2호
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• pp.125-129
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• 2012

With the development of the industry, such as homes and industries of electric energy usage and thereby increase the supply of electrical energy for power generation facilities were also increased. Among them an increase in thermal power plants, such as Bottom Ash was accompanied by an increase in industrial waste. If fly ash is recycled, some ten thousand Fly Ash and Bottom Ash Landfill, the recycling rate is low in most. In this study, in order to resolve the problem of fly ash recycling Bottom Ash to take advantage of low physical and chemical characteristics were analyzed. Evaluation of Physical Properties of Bottom Ash In addition, through the evaluation of functional properties of additives chogyeol condensation of 1 hour or more, within 3 hours of closing, Flow has more than 190mm of wheel load resistance value is less than 3mm flooring developed to study the subsequent emphasis on the Properties is based. Through these studies by developing a functional flooring help with the problem of resource depletion, and losses due to reclamation and pollution is to prevent.

• 한국환경과학회지
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• 제20권8호
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• pp.1061-1068
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• 2011

Evapotranspiration is one of the important elements related water cycle and there is many kind of measurement method of evapotranspiration today. This study developed mini lysimeter for the purpose of direct measurement of evapotranspiration and installed on 5th, July, 2010 at the field of MRI which located at Tsukuba, Ibaraki, Japan for continuous measurement and understand relation between evapotranspiration and meteorological elements expecially radiation elements. And compared the evapotranspiration data of lysimeter with Bowen Ratio Method. The result of this study is as follows; There is high related with solar radiation and evapotranspiration with $R^2$=0.947. and 46 % of solar radiation converted into evapotranspiration during clear 5 days. In net radiation also highly related with evapotranspiration, we can derive evapotranspiration is mainly controlled by radiation energy in clear days. From the 104 days data, there is only 9 % difference between Bowen Ratio Method and evapotranspiration of lysimeter which was developed from this study is very useful to estimate evapotranspiration at field site with simple and high accuracy. High accuracy and resolution measurement of evapotranspiration by lysimeter can give a chance further study of meteorological phenomena of on ground expecially in night time condensation which means abnormal energy flow.

• 대한기계학회논문집B
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• 제24권3호
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• pp.346-353
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• 2000

In this paper, heat transfer characteristics of a loop type capillary heat pipe were experimentally investigated for the effect of several fill charge ratios of working fluid and heat loads. This type of heat pipe consists of a heating section, a cooling section and an adiabatic section. The heat pipe used has a 0.002m internal diameter, a 0.34m length in one turn and consists of 19 turns. Heating and cooling sections each have a length of 70mm. Experiments were performed to measure the temperature distributions and the pressure variation of the heat pipe. Heat transfer performance, effective thermal conductivity, boiling heat transfer and condensation heat transfer coefficients were calculated for various operating conditions of heat pipe and it was found that heat transfer characteristics of this type heat pipe were very excellent. As shown by this experimental study, this type of heat pipe operates by oscillatory flow caused by pressure and temperature oscillations.

• Nuclear Engineering and Technology
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• 제34권5호
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• pp.421-432
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• 2002

As one of the advanced design features of the APR1400, direct vessel injection (DVI) system is being considered instead of conventional cold leg injection (CLI) system. It is known that the DVI system greatly enhances the reliability of the emergency core cooling (ECC) system. However, there is still a dispute on its performance in terms of water delivery to the reactor core during the reflood phase of a large-break loss-of-coolant accident (LOCA). Thus, experimental validation is under progress. In this paper, test results of direct ECC bypass performed in the steam-water test facility tailed MIDAS (Multi-dimensional Investigation in Downcomer Annulus Simulation) are presented. The test condition is determined, based on the preliminary analysis of TRAC code, by applying the ‘modified linear scaling method’with the l/4.93 length scale . From the tests, ECC direct bypass fraction, steam condensation rate and information on the flow distribution in the upper annulus downcomer region are obtained.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.358-363
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• 1995

A study on passive cooling systems for concrete containment of advanced pressurized water reactors has been performed. The proposed passive containment cooling system (PCCS) consist of (1) condenser units located inside containment, (2) a steam condensing pool outside containment at higher elevation, and (3) downcommer/riser piping systems which provide coolant flow paths. During an accident causing high containment pressure and temperature, the steam/air mixture in containment is condensed on the outer surface of condenser tubes transferring the heat to coolant flowing inside tubes. The coolant transfers the heat to the steam condensing pool via natural circulation due to density difference. This PCCS has the following characteristic: (1) applicable to concrete containment system, (2) no limitation in plant capacity expansion, (3) efficient steam condensing mechanism (dropwise or film condensation at the surface of condenser tube), and (4) utilization of a fully passive mechanism. A preliminary conceptual design work has been done based on steady-state assumptions to determine important design parameter including the elevation of components and required heat transfer area of the condenser tube. Assuming a decay power level of 2%, the required heat transfer area for 1,000MWe plant is assessed to be about 2,000 ㎡ (equivalent to 1,600 of 10 m-long, 4-cm-OD tubes) with the relative elevation difference of 38 m between the condenser and steam condensing pool and the riser diameter of 0.62 m.

• Asian Pacific Journal of Cancer Prevention
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• 제16권13호
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• pp.5507-5513
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• 2015

Momordica cochinchinensis Spreng (MC) has been used in traditional medicine due to its high carotenoid content. The objective of this study was to investigate mechanisms underlying apoptotic effects of MC on human MCF-7 breast cancer cells. A lycopene-enriched aril extract of MC (AE) showed cytotoxicity and antiestrogenicity to MCF-7 cells. On DAPI staining, AE induced cell shrinkage and chromatin condensation were evident. With flow cytometric analysis, AE increased the percentage of cells in an early apoptosis stage when compared with the control group. RT-PCR analysis showed AE to significantly increase the expression of the proapoptotic bax gene without effect on expression of the anti-apoptotic bcl-2 gene. Moreover, AE enhanced caspase 6, 8 and 9 activity. Taken together, we conclude that AE of MC fruit has anticancer effects on human MCF-7 breast cancer cells by induction of cell apoptosis via both intrinsic and extrinsic pathways of signaling.

• 한국전산유체공학회지
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• 제17권3호
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• pp.25-32
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• 2012

This work was devoted to compare two different cavitation models to study the dependency of model constants. The cavitation model of Merkle et al.(2006) and Kunz et al.(2000) were used for the present computational study. The cavitation models were coupled with the incompressible unsteady Reynolds-Averaged Navier-Stokes solver to indicate the vaporization and condensation processes. For this purpose, a preconditioning method was added as the pseudo-time term to solve the unsteady stiffness problems. For the validation of the numerical simulation, the computation was performed for the cavitating flow in a converging-diverging channel. The present results show that Merkle's cavitation model is independent to the model constants, and the higher numerical accuracy over Kunz's cavitation model.

• 대한기계학회논문집B
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• 제24권6호
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• pp.760-768
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• 2000

Filter efficiency of electrically charged particle in uncharged fibrous filter was measured. In previous studies, the effect of charged particle on filter efficiency was investigated but there was difficulty in measuring of image effect that is appeared at the charged small particle. We could easily measure the image effect with charging small particles by photoelectric charging. The spark discharge aerosol generator and a differential mobility analyzer (DMA) were used to generate sub-micron monodisperse particles (${\leq}200$ nm). The generated particles were charged in photoelectric charging process using ultraviolet lamp and electric field. The filter efficiency of the charged particles, classified by another DMA, was measured in filter tester using a condensation nucleus counter (CNC) as function of particle diameter, particle charge and airflow velocity. It is shown that the filter efficiency increases with increasing charge number of the particle and is affected by particle size and flow velocity. Single fiber filter efficiency mainly depends on image force parameter and peclet number. The peclet number was not considered at previous other papers. We propose a modi fied experimental correlation as function of image force parameter and peclet number.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.276-281
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• 2000

A simulation program using the mass transfer correlation was constructed to analyze 1-D simplified condensing flow across the tube bank. Higher efficiency was anticipated by reducing the flue gas temperature down below the dew point where the water vapor in the flue gas is condensed at the surface of the heat exchanger; that is, the heat transfer by the latent heat is added to that by the sensible heat. Thus, there can be an optimum operating condition to maximize the heat recovery from the flue gas. The temperature rises of the flue gas and the cooling water between the inlet and the outlet of the tube bank were compared with the experimental data reported previously. The predicted results agree well with the experimental data. Using this simulation program, the parametric studies have been conducted fur various operating conditions, such as the velocities and temperatures of the vapor/gas mixture and the cooling water, the number of the rows, and the conductivity of the wall material.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.156-157
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• 2017

It is possible in the case of the chemical admixtures for concrete currently being used in actual work sites to omit quality evaluation and replace it with the scores of the admixture manufactures; this can create a problem of decline in reliability in quality on the work site. Therefore this study sought to analyze the degree of influence changes in the solid content rate of lignin- and naphthalene-based water-reducing agents have on the fundamental characteristics of cement mortar. The results showed that in fresh mortar, the flow and amount of air decreases with decrease in the solid content ratio. In hardened mortar, the condensation strength had hardly any effect on the use of lignin-based water-reducing agent, but naphthalene-based water-reducing agent increased with the decrease in the solid content ratio.