• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.186-191
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• 1998

Electropolishing is the anodic dissolution process in the transpassive state. It removes non-metallic inclusions and improves mechanical and corrosion resistance of stainless steel. If there is a Bailby layer, it will be recovered again. Electropolishing is normally used to remove a very thin layer of material on the surface of a metal component. The aim of this study is to determine the tendencies of electropolishing STS316L tubes in terms of current density, machining time, temperature, electrode gap and surface roughness.

• Steel and Composite Structures
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• v.9 no.3
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• pp.209-221
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• 2009

Heating correction, through heating and flattening a structure with a pressing machine, is the in-situ method used to repair buckled steel structures. The primary purpose of this investigation is to develop an FEM model which can predict the mechanical response of heat-corrected plates accurately. Our model clarifies several unsolved problems. In previous research, the location of the imperfection was limited to the center of the specimen although the mechanical behavior is strongly affected by the location of the imperfection. Our research clarifies the relationship between the location of the imperfection and the mechanical behavior. In addition, we propose further reinforcement methods and validate their effectiveness. Our research concludes that the strength of a buckled specimen can be recovered by heating correction and the use of an adequate stiffener.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.202-208
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• 2001

Aluminum dross should be recycled in consideration of characteristics of the dross and its reutilization after processing. In this study, aluminum dross generated in the domestic secondary aluminum industry was processed to use it as raw material for producing aluminum hydroxide. Sample dross was classified according to its size. The dross smaller than 1mm was leached with sodium hydroxide solution to extract the remaining aluminum from the dross into the solution, and then aluminum hydroxide precipitate was recovered from the leach liquor. Purity of the obtained aluminum hydroxide was above 98 percent, and particle size of the sample was in range of 3-39${\mu}{\textrm}{m}$. From the result, it was suggested that this process could be applicable to recycling of aluminum dross.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.54-60
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• 2002

The Wastewater of toilet paper mill recycling recovered milk carton was used as a raw material for this study. According to the actual mill conditions, hydraulic retention time was adjusted to 12 hours and F/M (Food/Micro-organism) ratio was adjusted to 0.23. Temperature of aeration basin was varied from 2$0^{\circ}C$ to 5$0^{\circ}C$. The change of Micro-organisms and removal efficiency of pollutant were investigated at the varied temperature of basin. Aeration basin using high thermal microbial inoculants showed more removal efficiency of SS, COD than aeration basin using conventional microbial inoculants at high temperature. Floc consolidation of aeration basin using high thermal microbial inoculants added sludge was better than that of sludge from aeration basin using conventional microbial inoculants.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.223-227
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• 2007

Ground garlic inhibited the cross-linking reaction of myosin and incorporation of monodansylcadaverine (MDC) in salted Alaska pollack surimi catalyzed by transglutaminase (TGase). The component responsible for the inhibition was a thermostable, low molecular weight compound. The component also inhibited microbial transglutaminase (MTGase). The inhibition by garlic was reversibly recovered upon addition of 2-mercaptoethanol. The inhibitory component was therefore hypothesized to contain sulfhydryl groups within its structure. Alliin itself did not inhibit the cross-linking reaction. However, the addition of alliin together with garlic increased the inhibition. This result suggested that compounds derived from alliin was responsible for the inhibition of TGase activity.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.497-501
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• 2005

This study deals with the removal of mercury species using a packed-bed column with spherical aminated chitosan material. These adsorbents revealed a high adsorption capacity for mercury species. Experiments with feed solutions of 10 ppm Hg dissolved in distilled water showed an excellent removal with a sharp increase of the filter effluent concentration after a total throughput of 900 bed volumes of feed water. Up to $95\%$ desorption was reached by using 3 bed volumes of 0.01 N EDTA solution. EDTA could be recovered by means of sulfuric acid with about $75\%$ efficiency. Almost the same results were obtained in repeated sorption and desorption experiments at identical conditions. The experiments demonstrated that the sorbents possessed practically no sorption capacity for alkaline earth ions ($Ca^{2+}\;and\;Mg^{2+}$). Their influence on the sorption of mercury was negligible. In experiments with spiked tap water of the Karlsruhe Research Centre and a feed mercury concentration of 0.01 mg/l, the breakthrough of Hg was observed only after a total throughput of about 6,000 bed volumes of feed water.

• Journal of the Korean institute of surface engineering
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• v.19 no.1
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• pp.13-19
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• 1986

Manganese in the Anode slime and the paste-positive material of waste-dry cell was recovered by leaching with the hydrochloric acid solution. The impurities (Zn, Fe, Pb), co-leached with manganese were removed from the leached solution prior to electrolysis by hydrometallurgical techniques such as the neutralization with ammonium hydroxide and cementation on manganese powder. The electrodeposition of manganese from the purified chloride solution with sodium selenate was performed. Cathode current efficiency was found to be affected significantly by the concentration of sodium selenate and ammonium chloride salt, bath temperate, current density and PH. The current efficiency of about 88.7% was obtained by electrolysis manganese chloride solution with sodium selenate (0.1/g) at 10$^{\circ}C$.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.6
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• pp.294-301
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• 2021

In the present study, we investigate the effects of long-term heat treatment at elevated temperatures on the mechanical softening of the Mn-Mo-Ni low-alloy steel. The influence of long-term heat treatment on microstructure and mechanical strength was evaluated. To simulate the long-term material degradation, heat treatment test was interrupted at several stages up to 10,000 hours in an electric furnace. The Mn-Mo-Ni low-alloy steel shows a typical bainitic phase, which consists of a well-developed lath substructure with fine precipitates along the lath boundaries. However, these fine precipitates were redissolved into the matrix with long-term heat treatment, and then the lath substructures were recovered. Consequently, ultimate tensile strength and yield strength decreased during long-term heat treatment showing a mechanical softening phenomenon.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.5 no.4
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• pp.272-280
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• 1976

A natural ventilating type store was designed for the economic and effective storage of citrus fruits in Jejudo. The material used for the wall is scoria, widely distributed in Jejudo and known for high strength and insulation. Design condition was chosen for the period till March of a year and the dry bulb temperature was taken from TAC $5\%$ base. The temperature of the store can be maintained below the limiting temperature of $8^{\circ}C$ for the time length of $7\frac{1}{2}$ hours under the condition of the atmospheric temp, $15.3^{\circ}C$ and the solar insolation. The limiting temperature can he recovered to the initial temperature $(7^{\circ}C)$ by the natural ventilation for 8 hours in the night.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.10 no.1
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• pp.96-107
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• 2003

Objective: The purpose of this study was to identify the effects of tracheal suction and the effects of different methods of bronchodilator inhalation (Ultrasonic nebulizer: MDI puff, MDI puff with spacer) in VSD surgery patients. Material & Method: From June 2001 to March 2002, sixty consecutive patients were randomly assigned to a control group (n= 15), ultrasonic nebulizer group (n=15), metered dose inhalation (MDI) puff group (n=15) and MDI with spacer group (n=15). Vital signs (HR, BP, CVP), ABGA and pulmonary functions were measured before suction (baseline for suction), after suction, 15 minutes after suction (base of bronchodilator inhalation), 30 minutes after bronchodilator inhalation, and 2 hours after bronchodilator inhalation. Stastistical analysis was performed using SPSS software. Repeated measure ANOVA was used to examine the effects of tracheal suction. One way ANOVA with Bonferroni's correction and multiple range test (the least significant difference test) were used to examine the effects of albuterol inhalation. Result: 1. Heart .ate increased significantly immediately after suction (p<.01) and recovered 15 minutes after suction. 2. $PaO_2$ and PH decreased significantly immediately after suction (p<.05) and $PaO_2$ recovered 15 minutes after suction. $PaCO_2$ increased immediately after suction and significantly 15 minutes after suction (p<.01). But changes in vital signs and ABGA were within the normal range. 3. Tidal volume decreased significantly 15 minutes after suction (p<.05). 4. Changes of HR and tidal volume were greater in the nebuizer group compared to the other groups (p<.05) 30 minutes after bronchodilator inhalation and recovered 2 hours after bronchodilator inhalation. 5. Changes of airway deadspace was greater in the nebulizer group compared to the control group and MDI puff group 30 minutes after albuterol inhalation (p<.05) and at 2 hours (p<.01). Conclusion: Tracheal suction did not have significant effect on vital signs and pulmonary functions after OHS. Although the methods of bronchodilator inhalation did not showed any significant difference on pulmonary function, the nebulizer method increased $PaO_2$ (20%) and tidal volume transiently. If the patient needs bronchodilator inhalation with bronchospasm after OHS, the nebulizer method is the best choice. More study on the effects of bronchodilator inhalation in bronchospasm group is needed.