• Applied Biological Chemistry
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• v.24 no.4
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• pp.213-217
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• 1981

A Kimchi pasteurizer consisting of preheating, holding, cooling and liquid separation sections was built with copper tubing coil and glasses. The liquid portion of a Chiness Cabbage Kimchi prepared with 3% NaCl solution was preheated and held for 3 minutes at sterilization temperature. Thereafter it was cooled momentarily and recombined with the untreated solid part of Kimchi At four different temperatures of $68^{\circ}$, $75^{\circ}$, $81^{\circ}$ and $85^{\circ}C$ Kimchi was sterilized and examined for the sterilization effects by measuring acid and pH changes of the Kimchi when stored at $15^{\circ}C$. The shelf-life of sterilized Kimchi was prolonged by two folds compared with the untreated one. When Kimchi was sterilized at different maturing stages. the less cured one prolonged its shelf-life more effectively.

• Analytical Science and Technology
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• v.13 no.2
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• pp.158-165
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• 2000

The purity of gypsum and quantitation of impurities of flue gas gypsum will not only play an important role in deciding of the optimal condition during a trial run of FGD (flue gas desulfurization), but also can be utilized in quality control of gypsum. The purity of gypsum can be determined from combined water, sulfur trioxide and calcium concentration. We found that the thermal analysis by TGA (thermogravimetric analysis) was the most accurate and convenient method to determine the purity of gypsum. This method will be done in a hour and the results were reproducible. On the other hand, the best way of the analysis of impurities in gypsum was fusion method using $LiBO_2$ as a fusion agent. We also determined the amount of $CO_2$ gas to analyze magnesium carbonate and calcium carbonate contents. The analyses of combined water by TGA, fusion method followed by ICP-AES (inductively coupled plasmaatomic emission spectroscopy) and determination of $CO_2$ amount can lead to more accurate and convenient method for gypsum analysis.

• Clean Technology
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• v.22 no.3
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• pp.141-153
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• 2016

Numerous stationary NO_x emission sources have employed a suitable deNO_x technology that is typically selective catalytic reduction (SCR) of NO_x by NH₃ over V₂O₅/TiO₂-based catalysts with on-demand monolithic structures. These structured catalysts undergo a time-on-deterioration of deNO_xing activity on site. Thus, we need more efficient, more deactivation-tolerant, more economic deNO_x systems and for which, their performance management is essential. This review has covered details of strategies to successfully manage the performance of SCR catalysts and timely replace them to new or rejuvenated ones. Key considerations to maintain the catalyst activity will be reviewed. Details of the sequential addition of new catalysts and the replacement of life-end catalysts and their regeneration will be discussed with general guidances to determine the time for such a replacement. Finally, a better way to get more economic approaches to deNO_x system management will be proposed here.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.58-64
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• 2006

Recently deep interests have been paid on the effective generation of ozone, which has been widely used for water treatment, deodorization, color removal, and chemical processing of exhausted smoke. The silent discharge reaction has been proposed as the most effective one in the many ozone generation methods, because the silent discharge can be generated under the conditions of lower applied voltage and power consumption, compared other ones. In this paper, in order to improve the ozone generation and ozone generation efficiency, the conventional silent discharge chamber with $Al_2O_3$ dielectric layer and tubular ferroelectric bed discharge reactor packed with $Al_2O_3$ pellets were made, and the silent discharge of the reactors were studied experimentally. The ozone generation characteristics are also discussed based on the discharge characteristics, especially on the wall charge accumulation properties and power consumption. The results show that the electric charges of discharge tube with bead are around 2.5 times as large as those without bead. In the discharge chamber packed with dielectric beads, the ozone concentration and the energy yield characteristics were also improved, compared with those in the conventional silent discharge reactor.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.361-373
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• 2020

The purpose of this study was to meta-analyze the stress intervention program applied to patients with hemodialysis in Korea to confirm the effectiveness of the stress intervention program and to identify the characteristics and trends of the stress intervention method. A total of 10 studies were selected, and Quality Assessment tool was used MINORS and the data was analyzed using Comprehensive Meta Analysis Version 3.0 and Review manager version 5.3 The Quality Assessment score of studies was 21.2 points, and the effect size on the psychological stress was medium(g=-.72), and the effect size on cortisol of the physiological stress was also medium(g=-.52). Subgroup analysis showed that Music therapy and aromatherapy, individual providing, over 60 minutes per session and total of 10-20 times were more effectively reduced stress. Findings of this meta-analysis would be helpful for health professionals to provide more effective stress intervention program. Further randomized controlled trials of stress intervention program for patients with hemodialysis are more needed.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.37-42
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• 2008

This study is focused on the numerical predictions for different smoke-control ventilation modes for the subway fire. Smoke-control ventilation mode in the domestic platform is that exhausting for the smoke detected zones while supplying air or stopping any ventilation for other zones in the platform. Three cases of smoke control ventilation modes are considered. First and second case are present running smoke control mode in Korea. The third is that smoke-control ventilation fans equipped in the platform are operated in first 4 minute(platform evacuation time, NFPA130) since then the fans equipped in the platform are stopped and the fans equipped in the tunnels are operated. Distributions of heat, carbon monoxide and visible range are compared at a height of 1.7m(passenger breath/sight height) above the platform. The numerical results show that air supply fan operation in the platform causes the smoke disturbance and a rapid spread of the smoke. The switch-operation with fans in both the platform and tunnel are better than operation with only platform fans in smoke rejection efficiency.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.753-756
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• 2008

Recently, construction work period reduction is a very important topic of construction business circles. Because that is just big cost reduction. There is an important part of construction to decide the removal time of form. For prediction strength for removal form, P type schmidt hammer method and maturity method is used that. In case early strength prediction of maturity method, that is problem. Because setting duration of concrete is not proper considering. So this experimental study is a coefficient(A) of maturity method.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.327-333
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• 1999

Controlled Ca impurity implanted inner crack-like pore in the high purity alumina bi-crystal had been created by micro-fabrication technique, which includes ion implantation, photo-lithography, Ar ion milling, and hot press. The morphological change and the growth od crystals formed by heat treatment in Ca doped high purity single crystal alumina, were observed using optical microscopy. The dot was developed and hexagon like crystal appeared on inner surface of crack-like pore after heat treatment. Bar type crystals, probably CaO . $6Al_2O_3$, were observed on the inner surface of 100ppm Ca implanted specimen after 1 hour heat treatment at $1,500^{\circ}C$, but this bar type crystal disappeared after 1 hour heat treatment at $1,600^{\circ}C$. This disappearance means that there should be little increase of Ca solubility limit to alumina and/or changes of diffusion coefficient of Ca in alumina around this temperature.

• Fire Science and Engineering
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• v.34 no.3
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• pp.49-57
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• 2020

Apartment buildings are becoming taller and more densely populated with the advancements in science and the development of cities, Consequently, various amenities and safety facilities are being developed to improve the quality of life for residents. However, according to statistics, the number of casualties in apartments accounts for a high proportion of accidents, and the leading cause of the casualties is smoke emitted from fires while sleeping at night. Although it is best to install separate indoor facilities in apartments to minimize smoke damages to occupants, it is useful to minimize the smoke damages by utilizing the installed facilities while reducing the financial burden of occupants. Based on the review, the heat exchanger ventilation system and the kitchen collective exhaust system were selected, and the feasibility of these systems was verified through fire simulation. From the verification results, the available safe egress time improved by 27, 30, and 35 s on the 25th, 35th, 50th floors, respectively.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.1-9
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• 2019

In the flue gas desulfurization process of the coal-fired power plant, the grinding efficiencies of the limestone as the sorbent for desulfurization were compared after BWI and HGI measurements. As a result, the grinding index of the domestic desulfurization limestone were linear inversely proportional relationship with decreasing BWI was observed with increasing HGI. There was a difference in grinding efficiency depending on the chemical composition and crystal structure. Therefore, it is considered that when grinding ability of limestone is measured, the grinding property of the sample can be confirmed even by using HGI which can be measured more easily than BWI which is difficult to measure and takes a long time. The desulfurization efficiency can be improved by selective utilization of limestone depending on the crushing characteristics.