• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.1
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• pp.79-87
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• 1998

Basic design of a 50USRT(175㎾) triple effect absorption chiller driven by hot gas has been carried out for both parallel and series flow cycles. Parallel flow cycle showed higher COP, however, the temperature in the generator was also higher than that in series flow cycle. Dynamic operation behavior of a parallel flow system at off-design conditions, such as the change in heat transfer medium temperature or the construction change of the system components, has been investigated in detail. It was found that the cooling capacity was seriously decreased by reducing hot gas flow rate and UA-value in the high temperature generator. However, the system COP was improved, because thermal load in the system components was reduced. The COP and the cooling capacity was found to be improved as cooling water temperature decreased or chilled water temperature increased. The optimum ratio of solution distribution could be suggested by considering the COP, the cooling capacity and the highest temperature in the system, which is critical for corrosion.

• Membrane Journal
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• v.1 no.1
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• pp.78-95
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• 1991

Water factory 21(WF 2) in Orange County California, is a advanced wastewater treatment(AWT) plant designed to reclaim biologically treated munidpal wastewater for injection into a seawater barrier system. Processes included are lime treatment air stripping, filtration, activated carbon adsorption, reverse osmosis(RO), and chlorination. The effectiveness of each treatment process is presented including pretreatment, RO dimineralization. The data collected show that the processes, including RO, used at WF-21 are capable of producing a very high quality water on a reliable basis. Treatment reduced all contaminants, to levels below national primary drinldng water regulation maximum contaminant levels. It was found that lime clarified secondary effluent can be used as feedwater to a RO dimineralizer. Experiments with new low pressure membrane(250psi) show great potential for reducing RO cost.

• Journal of Korean Clinical Nursing Research
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• v.20 no.2
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• pp.200-210
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• 2014

Purpose: The main purpose of this study was to effect oral care methods between essential oil gargling and purified water gargling for postoperative patients who had general surgery or orthopedic surgery. Methods: The postoperative patients were assigned to one of two groups. One group gargled with essential oil and the other with purified water. All group gargled three times interval 2 hours. Each patients thirst, oral condition and halitosis were assessed four times. Results: After oral care was provided once, there were significant differences in thirst level between two groups. when oral care was provided once and three times, there were significant differences in oral condition between two groups. but there were no significant differences in halitosis between two groups. Conclusion: The results show that essential oil gargling is a more effective intervention than purified water gargling for post operative patients oral care in reducing the thirst level and improving the condition of the oral cavity.

• Corrosion Science and Technology
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• v.16 no.5
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• pp.265-272
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• 2017

Inhibition of pitting corrosion of the copper sprinkler tubes by removing dissolved oxygen in water with sodium sulfite was studied on the wet sprinkler systems operated in 258 household sites. First, air in the sprinkler tubing was removed by vacuum pumping. The tube was then filled with sodium sulfite dissolved in water. Sodium sulfite was very effective in maintaining a very low dissolved oxygen concentration in water in the sprinkler tube for the observation period of six months. Water leakage from the copper sprinkler tube was reduced significantly by using sodium sulfite. Both pitting corrosion process and pitting corrosion inhibition mechanism were investigated by examining microscopical and structural aspects of corrosion pits formed in failed copper sprinkler tube. Pitting corrosion was caused by pressurized air as well as sediments such as sand particles in copper tubes through oxygen concentration cells. It was confirmed microscopically that growth of corrosion pits was stopped by reducing dissolved oxygen concentration to a very level by using sodium sulfite.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.585-588
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• 2006

The environment-friendly building material, photocatalyst/scoria/loess concrete, was prepared using scoria and loess (which have merits as building materials) and photocatalyst (which has the functions to compose the environmental contaminants and of self cleaning). In order to apply this material as a building material, the compressive and flexible strengths, and water absorptivity (which have been set by Korea Industrial Standard) were measured. The optimum mixing ratio of photocatalyst/scoria/loess concrete was obtained at the condition of $393kg/m^3$ of coarse aggregate, $802kg/m^3$ of fine aggregate in case of scoria, $80kg/m^3$ of loess, $12kg/m^3$ of photocatalyst, $400kg/m^3$ of cement, and $2kg/m^3$ of AE water reducing agent. The photocatalyst/scoria/loess concrete prepared by above mixing ratio of raw materials showed 25 MPa of compressive strength, $3.8{\sim}4.6$ MPa of flexible strength and $11.4{\sim}12.0%$ of water absorptivity, indicating that the quality of this material was suitable for Korea Industrial Standard (more than 21 MPa for compressive strength, more than 2.0 MPa for flexible strength in case of lightweight aggregate, and less than 15 % for water absorptivity in case of clay brick) for using as a building material.

• Journal of Electrochemical Science and Technology
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• v.2 no.2
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• pp.85-90
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• 2011

Active oxygen species or free radicals are considered to cause extensive oxidative damage to biological macromolecules, which brings about a variety of diseases as well as aging. Electrolyzed reduced water(ERW) has been regarded as a ideal antioxidative agent in recent years. ERW is produced by passing a diluted salt solution through an electrolytic cell, within which the anode and cathode are separated by membrane. It can be produced reactive materials in ERW near the cathode during the electrolysis of water. ERW have the following advantages over other traditional cleaning agents: effective antioxidative agent, easy preparation, inexpensive, and environmentally friendly. The main advantage of ERW is its safety and antioxidative effect. ERW with strong reducing potential can be used to remove dirt and grease from items such as cutting boards and other kitchen utensils. The primary aim of this study is the activation mechanism of oxidation reduction potentials, ion conductivity, pH, and electrochemical properties with reactive materials in ERW.

• Journal of Environmental Science International
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• v.15 no.5
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• pp.431-438
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• 2006

The strength, water permeability, and photo-degradation efficiency of NOx of porous concrete with a new concept were studied in this paper. The porous concrete was comprised of coarse aggregate of maximum size 40 mm, cement, silica fume, water and air-entraining(AE) water reducing agent. The strength of porous concrete was strongly related to its matrix proportion and compaction energy. An experimental test was carried out to study the parameters of cement proportions and silica fume content for pavement applications of porous concrete which were paving a footpath, a bikeway, a parking lot, and a driveway. The regressed equations of relation-ships between compressive strength and flexural strength, and coefficient permeability and void ratios were indicated as y=7.69x+71.74 and $y=0.42e^{0.28x}$. A method of making an air purification-functioning road, which was spraying a mixture of a photocatalyst, cement, and water onto the surface of the road, was suggested.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.773-780
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• 2012

The article presented is concerned with an evaluation of the corrosion behavior of SA-508 low alloy steel (LAS) and Type 309L stainless steel (SS) cladding of a reactor pressure vessel under the simulated primary water chemistry of a pressurized water reactor (PWR). The uniform corrosion and galvanic corrosion rates of SA-508 LAS and Type 309L SS were measured in three different control conditions: power operation, shutdown, and power operation followed by shutdown. In all conditions, the dissimilar metal coupling of SA-508 LAS and Type 309L SS exhibited higher corrosion rates than the SA-508 base metal itself due to severe galvanic corrosion near the cladding interface, while the corrosion of Type 309L in the primary water environment was minimal. The galvanic corrosion rate of the SA-508 LAS and Type 309L SS couple measured under the simulated power operation condition was much lower than that measured in the simulated shutdown condition due to the formation of magnetite on the metal surface in a reducing environment. Based on the experimental results, the corrosion rate of SA-508 LAS clad with Type 309L SS was estimated as a function of operating cycle simulated for a typical PWR.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.38-46
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• 1998

The purpose of this study is to evaluate and compare the effective coagulation of commercial humic acid which is well known as major precursor of trihalomethane, with LAS and PAC and to quantify the residual aluminum in the treated water. Then the optimum pH, the dosage of coagulant were determined. 1. Humic acid concentrati6n, UV absorbance and color were well correlated and UV absorbance(254 nm) and color seem to be used in quntificative analysis of humic acid of same kind. 2. Optimal dosage of LAS and PAC increase as humic acid concentration increases. And optimal pH range for coagulation using LAS is pH 5.5-7.0 and pH 3.5-6.5 for PAC. Within these ranges the removal efficiency is 90-99%. 3. The results of quantification of residual aluminum in treated water shows that minimal aluminum remains on the optimal coagulation condition. But the residual aluminum increses as the dosage of coagulant is beyond the optimal range. Thus the dosage of coagulant should be chosen with the condition on which humic acid removal is maximum and the residual aluminum concentration is minimum. 4. In the water treatment process the raw water pH range is 6.5-8.0, and it seems to be possible to remove humic acid by charge neutralization not by sweep floc. But it should be considered that different commercial humic acids have different physical and chemical characteristics.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.3
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• pp.15-26
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• 2013

Objectives The aim of this study was to investigate antimicrobial activity of Huanggeumjakyak- tang water extract against MRSA. Methods The antibacterial activities of Huanggeumjakyak-tang were evaluated against 3 strains of Methicillin-resistant Staphylococcus aureus (MRSA) and 1 standard Methicillinsusceptible S. aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay was performed under dark. Results The MIC (minimum inhibitory concentration) of Huanggeumjakyak-tang water extract against S. aureus strains ranged from 1,000 to $2,000{\mu}g/ml$. So we confirmed that it has a strong antibacterial effect. Also the combinations of Huanggeumjakyak-tang water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. Conclusions The results obtained in this study suggest that Huanggeumjakyak-tang water extract showed antibacterial effect against MRSA, and it also showed reducing effect on the side-effect problems that are the major weak points of traditional antibiotics.