• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.2
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• pp.59-66
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• 2016

The purpose of this study was to review of technical, economical feasibilities regarding Integrated Two-Phase Anaerobic Digestion(ITPAD) method. In order for that, operation conditions and data with 24tpd capacity of operating ITPAD plant were analyzed. The result showed that VS removal efficiency was 73.7% and total amount of biogas was generated $1,239m^3/day$ on the average that represents $54.4m^3/ton$-input of generation efficiency. ITPAD had advantages in terms of required area and energy for heating which were analyzed 15.9%~47%, 11.6%~17.8% lower respectively compared to Conventional Separated Two-Phase Anaerobic Digestion(CSTPAD) method. Thus, it is considered the ITPAD has comparatively high feasibility to be expanded and commercialized to dispose high concentration organic matter of waste such as food waste and its leachate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2898-2903
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• 2011

Adsorption/desorption characteristics of low concentration methylethylketone(MEK) and toluene vapors in beds packed with activated carbon fibers(ACF) was investigated. Performance of ACF adsorption was characterized by the equilibrium capacity, time to reach equilibrium and desorption efficiency. Experiments were carried out to define the effect of operation variables, such as feed concentration, flow rate, moisture content and bed height. The breakthrough time was shorten with the increase of temperature, flow rate and feed concentration. In addition, an increase of packed height of adsorbents lengthen the breakthrough time. The ACF loaded with MEK and toluene was satisfactorily regenerated by programed heating. It is observed that MEK is more easily removed than toluene at below temperature of $150^{\circ}C$.

• Journal of the Korean Society of Safety
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• v.35 no.4
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• pp.74-83
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• 2020

In Korea, about 110,000 LPG small storage tanks of less than three tons have been installed in restaurants, houses and factories, and are used as LPG supply facilities for cooking, heating and industrial use. In the case of combustible liquefied gas storage tanks, the tank may rupture due to the temperature increase of the tank steel plate (approximately 600℃) even when the safety valve is operating normally, causing large-scale damage in an instant. Therefore, in the event of a fire near the LPG small storage tank, it is necessary to accurately predict the timing of the BLEVE(Boiling Liquid Expanding Vapour Explosion) outbreak in order to secure golden time for lifesaving and safely carry out fire extinguishing activities. In this study, we have first investigated the results of a prior study on the prediction of the occurrence of BLEVE in the horizontal tanks. And we have developed thermodynamic models and simulation program on the prediction of BLEVE that can be applied to vertical tanks used in Korea, have studied the effects of the safety valve's ability to vent, heat flux strength of external fires, size of tanks, and gas remaining in tanks on the time of BLEVE occurrence and have suggested future utilization measures.

• Korean Journal of Human Ecology
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• v.19 no.4
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• pp.745-760
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• 2010

The purposes of this study were to investigate the state of indoor thermal and air environment during winter in the one-room type multi-family houses occupied by university students and to analyze factors which influenced this environment. Field survey was conducted in 10 houses between 30th January, 2009 and 13th February, 2009 which measured indoor thermal and air elements as well kept records of interviews with residents and other related factors. Measured elements were air temperature, relative humidity, as well as concentrations of $CO_2$, CO, TVOC, and PM-10. The results can be summarized as follows. 1) The mean air temperature in each house ranged from 19.3 to $25.3^{\circ}C$, so most houses were not suitable for evaluation criteria($20-22^{\circ}C$). The average $CO_2$ concentration in each house was 965~3259ppm, so most houses exceeded evaluation criteria(1000ppm). The average TVOC concentration in each house were 0.00~1.17ppm, 5 houses exceeded evaluation criteria(0.12ppm). 2) Relative humidity, CO concentration, and PM-10 concentration were suitable for evaluation criteria. Therefore, indoor thermal and air environment during winter in one-room type multi-family housing occupied by university students was found to be generally uncomfortable. Important factor which were found to influence air temperature and the concentration of $CO_2$ were smaller space capacity than general house. Other factors which were found to influence the environment of these houses were the existence of a balcony as well as factors relating to the behavior of occupants such whether or not heating were operated, whether windows were opened, whether fans used, whether occupants smoked or used cosmetics, and whether the space was dusted.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.439-449
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• 2014

RPS (Renewable Portfolio Standard) has increased wood pellet demand dramatically in recent years in Korea where self-supply rate of wood pellet is not more than 10%. However global production capacity of wood pellet is prospected to be unable to meet the global demand after 2020. Therefore it is urgently needed to develop new sustainable biomass energy resources which can replace wood pellet at lower cost. As a result of this study EFB (empty fruit bunch) and MF (mesocarp fiber), the representative solid palm biomass, are estimated to be generated at the rate of 20 and 28 million tons per year (based on 10% moisture content) in Malaysia and Indonesia, respectively in 2012. Total annual generation rate of EFB and MF is estimated as 48 million tons per year only in Malaysia and Indonesia in 2012. With calorific value of over 90% of wood pellet EFB is expected to be a excellent biomass energy resource which can replace wood pellet. EFB can be utilized as fuel for power generation or industrial purpose. However EFB may not be a proper fuel for domestic and greenhouse heating because of its high ash content.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.61-68
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• 2010

Rice bran proteins from different cultivars(Youngan, Sindongjin, Suwon 511) were extracted with Xylanase using orthogonal analysis method and their functional properties were investigated. The optimum extraction conditions, based on protein content in the extract found to be at 1 wt% xylanase, pH 7 and 50:1, solvent to rice bran ratio(v/w %). Nitrogen solubility indices(NSI) of rice bran protein concentrates were shown a minimum value at pH 4 ranged 2~23%, varied with different cultivars and a maximum (NSI${\geq}$90% for all cultivars) at pH 10. As for water adsorption and fat adsorption capacity, rice bran protein concentrates were shown to be better than Na-caseinate and isolated soy protein, respectively. Emulsifying activities were observed high in order of Na-caseinate>Youngan rice bran protein>Shindongjin rice bran protein>Suwon 511 rice bran protein>isolated soy protein. In general, the surface tension of rice bran protein solution($10^{-3}$ wt%, 5 mM bis-tris, pH 7) was increased with increasing concentrations and found a minimum value near pI. On heating, it was decreased slightly with increasing temperatures up to $70^{\circ}C$ and then increased above $80^{\circ}C$. Addition of sodium chloride was made the surface tension decrease. In conclusion, with Xylanase, rice bran protein concentrate can be successfully extracted from the rice bran of different cultivars and the Youngan rice bran protein was thought to have best functionality among rice cultivars tested. It might be used as a milk protein substitute.

• Journal of the Korea Institute of Building Construction
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• v.9 no.1
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• pp.103-109
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• 2009

Strong winds according to global warming cause the increase of the frequency and the repair cost of damaged roofs. In the United States, Factory Mutual Insurance Company(FMIC) promotes the roofing design that resists heavy wind-load, as the means of strict criteria. This fact reveals that more durable roofing system will be also required in Korea. Therefore, this study aims at developing such a system with high wind-resistance performance using Thermoplastic polyolefin(TPO) and Electromagnetic induction technology(EIT) than the previous systems. The system presented in this study consists of 4 main devices as follow; 1) a disc to fix sheets for TPO & EIT method, which can conduct structural design according to site condition, such as region, building height, and wind load. 2) a nail to have about 30% stronger lifting-up capacity than that of the previous nail. 3) a disc to fix sheets, which has triangle protuberance not to damage sheets in the repeatable wind load, and 4) a electromagnetic induction device to combine a disc and a sheet by heating uniformly and quickly adhesive agent on the disc. The results of mock-up test illustrate that the system provides wind-resistant performance to achieve satisfactorily the structural design criteria of FMIC. In addition, the system is faster, chipper, and easier than the existing system, and is expected that this roofing system can be applied to the rehabilitations of an existing as well as a new building.

• Journal of Advanced Marine Engineering and Technology
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• v.14 no.4
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• pp.57-66
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• 1990

In the design of an electric power plant, the capacity to meet the peak load demand is one of the important factors to be considered. This peak load usually occurs when the most of the cooling air conditioning systems are being operated during daytime in summer season, which inevitably entails the construction of an additional electric power plant. This study is aimed to carry out a basic experiment for the development of a cooling air conditioning system using the ice energy by the surplus electric power during the night-time. The experimental apparatus consists of four major parts; (1) the heating section consisting of the air duct and I.D. fan, (2) the cold section with the ice chamber, (3) the bundle of heat pipes made in a form of the staggered arrangement with ${C_y}/{d_o}$=2.0 and ${C_x}/{d_o}$=1.73, (4) the refrigerator system to cool down the ice chamber. This study involves an intensive experiment concerning the convective heat transfer of the air flow surrounding the bundle of heat pipes. This major experimental parameters are the amount of working fluid, the velocity of air and the working temperature. The major findings of the present study are as follows; (1) The optimum amount of the working fluid necessary for the horizontal heat pipes is much more than that for the vertical type. (2) The convective heat transfer coefficients of the air are coincided with the empirical equations of Grimson and ${\breve{Z}ukauskas}$. (3) The equation of the mean heat transfer coefficient obtained in the present study is ${N_um}=0.32 {Re_max^{0.63}}$.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.445-450
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• 2012

At the limited space, the air conditioning may have difficult to control temperature or humidity for home use. Nowdays, the people reponse to temperature or humidity sensitively. This becomes the Indoor Air Quality (IAQ) is an important factor for comfortably. Heat recovery ventilator (HRV) is used for the solution of inconsistency between IAQ and power-saving. Also, the thermoelectric element is applied to HRV and compared with temperature efficiency and verifying the capacity of the system. To improve the temperature efficiency a single motor and thermoelectric element with the conductive guide vane is experimented. The results shows that it can save 23 W by using the single motor. The developed system of 250 CMH capacities with the thermoelectric element reveals the temperature efficiency improvement of 4.01% in cooling period and 2.98% in heating period compared to the conventional system.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.430-436
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• 2012

This study was conducted to measure battery's voltage drop in a compact electric vehicle to get driving performance in various driving situations. In the experiment, to evaluate the energy consumption and milage, system performance have measured with changing of the driving speed and the reduction of driving distance when the heater was operating. The battery of the car in this study is lead type storage battery. The driving velocity was changed from 10km/h to 50 km/h with 20km/h intervals and the operating step of the heating device. As results, the electronic consumption rate was maximum at 35 km/h of vehicle speed and if the driver turning the heater at maximum, capacity will lead to 35% of energy consumption increment.