• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.144-147
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• 2003

In this study, the mass transfer behaviors of phenanthrene, anthracene, and pyrene in soil slurry reactor (SSR) using two-liquid phase (TLP) system were investigated. The mass transfer ratio and rate of PAH in the TLP system using light paraffine oil, which has the highest solubility of PAH, were influenced by the amount of light paraffine oil and mixing speed. When the amount of light paraffine oil decreased from 15 % to 2.5 % (v/v), the mass transfer ratio of anthracene decreased significantly compared with that of phenanthrene and pyrene. As mixing speed increased, the initial mass transfer rate of PAH within 1 day was enhanced. However, each final mass transfer ratio of three PAHs after 5 day was similar irrespective of mixing speed.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.251-263
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• 2013

The internal reflux effect on dialysis through the retentate phase of a countercurrently cross-flow rectangular module is investigated. Theoretical analysis of mass transfer in cross-flow devices with or without recycling is analogous to heat transfer in cross-flow heat exchangers. In contrast to a device without reflux, considerable mass transfer is achievable if cross-flow dialyzers are operated with reflux, which provides an increase in fluid velocity, resulting in a reduction in mass-transfer resistance. It is concluded that reflux can enhance mass transfer, especially for large flow rate and feed-concentration operated under high reflux ratio.

• Mycobiology
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• v.34 no.4
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• pp.236-239
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• 2006

The purpose of this study was to investigate the effect of a Pholiota adiposa extract on fat mass in hyperlipidemic mice fed on a high-fat diet. The water extracts from P. adiposa (ASI 24018) were not affected in the total triglyceride contents and epididymal fat mass in mice fed on a high-fat diet, but the retroperitoneal fat mass decreased significantly. This result suggests that the P. adiposa extract may be a potential candidate for use as a functional food that can act as a prophylactic against hyperlipidemia. However, the P. adiposa extract showed no effect in the total triglyceride contents and epididymal fat mass.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.6
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• pp.468-476
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• 2002

This paper deals with heat and mass transfer characteristics and performance evaluation of a counter flow double-tube condenser for a multi-component refrigerant mixture. The local heat and mass transfer characteristics of ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a are evaluated for a counter flow double-tube condenser cooled by water. Then, the local values of vapor quality, thermodynamic states at bulk vapor, vapor-liquid interface and bulk liquid, heat flux and condensation mass flux are obtained. The heat exchange performance for ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a on the total pressure drop and the heat transfer characteristics are also compared with those for R404A, R410A, R502, R22, R32, Rl23 and R134a.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.940-945
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• 1998

Recently, serious cracking problems have been reported in this country while the process of actual massive concrete construction. he hydration heat arising from the chemical reaction of cement with water causes temperature differentials in between inside and outside of a structural member, and these temperature differentials induce thermal stresses. In this paper, we described on the practical application and quality control of the mass concrete mixed with fly-ash. This project is investigating adiabatic temperature rise test of concrete, mock-up test in the laboratory, ad B/P before placing the mass concrete in site. As a result, we can be prevent temperature cracking from the cement hydration heat of mass concrete and also can be showed up secure quality control flow chart of mass concrete.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.234-244
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• 2017

Natural frequencies of immersed square sections decrease due to a contribution of added mass to the movement of square sections. In this study, natural frequencies of square sections are obtained as a function of gap size between the square section and a rigid square wall using the finite element method. Additionally, they are used to extract the added mass effect on translational and rotation motions. Published information and studies on the translational and torsional vibration of square beams are also examined for practical use. D coupling of a square section is also investigated for multiple square sections. The suggested added mass estimation can be applicable to the spent fuel storage design of a pressurized light water modulated nuclear power plant.

• Bulletin of the Society of Naval Architects of Korea
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• v.7 no.2
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• pp.3-18
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• 1970

An investigation was made for the added mass moment of inertia induced by the rotational motion of the cylinder with hull section on water in order to obtain the information to estimate the natural frequency of the torsional vibration of ships. The special consideration to the effect of the draught upon the added mass moment of inertia is taken into account in the study. In this paper, the general expression for the added mass coefficients of moment of inertia of arbitary two dimensional forms induced by the torsional vibration, was derived by the author. Hence, the coefficients for these forms are represented as functions of parameters, the section area coefficient and draft beam ratio, from which the added mass coefficients for arbitrary forms can be obtained. The result was shown in a chart for estimation of the added mass moment of inertia induced by the torsional vibration, as first trial, for the convenience of practical use.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.111-115
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• 2006

To clarify the hydraulic and thermal characteristics of ice slurry which made from 6.5% ethylene glycol-water solution flow in the double tube and plate type heat exchanger, experimental studies were performed. The mass flux and Ice fraction of ice slurry were varied from 800 to $3,500 kg/m^2s$(or 7 to 17 kg/min) and from 0 to 25%, respectively. During the experiment, it was found that the measured pressure drop and heat transfer rate increase with the mass flux and ice fraction; however the effect of ice fraction appears not to be significant at high mass flux region. At the region of low mass flux, a sharp increase in the pressure drop and heat transfer rate were observed depends on mass flux.

• Tunnel and Underground Space
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• v.6 no.3
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• pp.197-208
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• 1996

Due to the constraints in pre site-investigation for tunnel, it is essential to redesign the support structures suitable for rock mass conditions such as rock strength, ground water and discontinuity conditions for safe tunnel construction. For the selection of optimum support, it is very important to carry out the rock mass classification and in-situ measurement in tunnelling. In this paper, in a mountain tunnel designed by NATM in hard rock, the selectable system for optimum support has been studied. The tunnel is situated at Chun-an in Kyungbu highspeed railway line with 2 lanes over a length of 4, 020 m and a diameter of 15 m. The tunnel was constructed by drill & blasting method and long bench cut method, designed five types of standard support patterns according to rock mass conditions. In this tunnel, face mapping based on image processing of tunnel face and rock mass classification by RMR carried out for the quantitative evaluation of the characteristics of rock mass and compared with rock mass classes in design. Also, in-situ measurement of convergence and crown settlement conducted about 30 m interval, assessed the stability of tunnel from the analysis of monitoring data. Through the results of rock mass classification and in-situ measurement in several sections, the design of supports were modified for the safe and economic tunnelling.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.235-243
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• 2007

In order to understand the water mass properties in the southern location of the East Sea in the Korean coasts, the vertical distributions (down to 2,000 m deep) of water temperature, salinity, and dissolved inorganic nutrients were determined in April of 2005. The water mass of the surveyed location showed distinct vertical layers; highly saline surface, surface mixing layer, and thermocline of low temperature and salinity. The water layer below 300 m was characterized by water temperature lower than $1^{\circ}C$ and salinity 34.06, showing a representative water mass of the East Sea. The inorganic nutrients rapidly increased from 200m in the northern and southern parts around Ulleung Basin. A marked environmental difference was found between two layers separated by thermocline. The upper layer of the thermocline was oligotrophic and the vertical distribution of nutrient was very stable. In the water layer between 100 and 200m the nutrients slightly increased but remained still stable. From southern coasts to northeastern Ulleung, the water mass properties were site specific; the thickness of the surface mixed layer and nutricline showed a trend diminishing toward the northern locations probably due to diminished influence of Tsushima water. Redfield ratio (N:P=16:1) based on the ratio of chemical composition in organism revealed that nitrogen value continuously decreased to less than 16 with the water depth down to loom from the thermocline. The value in the water layer deeper than 100 to 200 m, thereafter, showed an increasing trend (over 16). This result was further supported by the finding of lower chlrophyll a content in the layer.