• Journal of Conservation Science
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• v.26 no.2
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• pp.133-142
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• 2010

This paper focused on desalination method for the underwater archaeological ceramics. The desalination method applied in this study takes additional conditions such as the amount of desalting water, temperature, and agitation conditions and compares the effects of desalt process. The result of efficiency rate appears that the twenty-times of the object weight of desalting water is more effective than that of ten-times one, but shows less economic compared to the cost. In addition, the research shows that the efficiency rate has been improved around 20 to 30 %, yet such improvement is not taken into account as an effective result considering the risk of damage from the physical and chemical impact and the consumption of energy in applying additional method.

• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.399-404
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• 2010

This study was conducted to determine the influence of culture conditions such as temperature, time, water content, koji-thickness, and agitation on the production of protease by Rhizopus sp. ZB9, isolated from Korean Nuruk, during the preparation of rice koji, which is used in brewing the Korean rice wines, Takju and Yakju. Rice koji was made under different culture conditions, and the proteolytic activity of each koji was tested. The temperature range suitable for the production of protease was $28~32^{\circ}C$. Based on the protease and color, 60 hours of cultivation at $28^{\circ}C$ was shown to produce optimum results. The production of protease increased in proportion to the increase in water content of steamed rice from 25% to 35%. An increase in koji-thickness induced no adverse effects on the production of protease, and agitation during cultivation showed beneficial effects.

• KSBB Journal
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• v.13 no.6
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• pp.644-648
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• 1998

In the production of a low cost bacterial insecticide, it is important to produce a high spore concentration using low price substrates. Experiments were carried out to investigate the effects of the addition of mineral salts and glucose, and of dissolved oxygen concentration on the cell growth and spore formation of Bacillus thuringiensis var aizawai using a cheap wheat and soybean meal in the batch culture. The maximum viable cell number was 1.2${\times}$109 CFU/mL at 12 hr culture and spore yield was 54.2% at 74 hr culture using an industrial medium containing 20 g/L wheat meal and 30 g/L soybean meal under 1.0 vvm aeration and 200 rpm agitation. The cell growth and the spore formation were not enhanced by the addition of mineral salts in industrial medium, whereas th addition of 10g/L glucose decreased the cell growth and spore formation. We could obtain a maximum viable cell number of 2.2${\times}$109 CFU/mL and spore number of 1.9${\times}$109 CFU/mL at the dissolved oxygen concentration of 60% of saturation. The spore concentration was enhanced approximately by 2 times as compared to the dissolved oxygen concentration of 50%. In the bench-scale culture, the maximum viable cell and spore number were 2.5${\times}$109 CFU/mL, and 2.2${\times}$109 CFU/mL, respectively under 1.0 vvm aeration and 400 rpm agitation. The spore yield was 88% based on the maximum viable cell number. As a result, it was confirmed that the production of high spore concentration could be obtained by a bench-scale culture using an industrial medium.

• Polymer(Korea)
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• v.35 no.2
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• pp.152-156
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• 2011

We have performed microencapsulation of phenyl acetate using poly (urea-formaldehyde) as a shell material, and studied the effect of agitation rate,. core/shell mass ratio, surfactant concentration, and reaction time on capsule characteristics such as size, shell thickness, and surface morphology. The formation of microcapsules was confirmed by FTIR and TGA, and capsule characteristics were studied by optical microscopy and FE-SEM. Capsule size and shell thickness reduced with increasing agitation rate. As the mass of shell material was increased, shell thickness and nanoparticles on capsule surface increased. Capsule size and shell thickness decreased with increasing the concentration of a surfactant. Increasing reaction time caused increased capsule yield and shell thickness.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.94-102
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• 2015

Electro-coagulation experiments were conducted with aluminum (Al) or iron (Fe) electrode in order to determine the optimal electrode material and operation conditions for algae removal. Al electrode showed higher removal rate of algae than Fe electrode because Al flocs have positive surface charges which electrostatically attract algae species having negative surface charges. Removal rate of algae and total phosphorous (T-P) was increased as current density and electrode area increases. It was also found that initial pH with neutral range was optimum for T-P removal by electro-coagulation. Bench-scale continuous flow experiments consisted of electro-coagulation reactor, agitation tank and settling tank were conducted. In electro-coagulation reactor, a large fraction of Al flocs were distributed to scum layer, due to the gas bubbles generated by electrolysis reaction. In agitation tank, most of Al flocs were settled and the optimal mixing intensity was found to be 50 rpm to achieve good settleability. The removal rate of algae was about 90-95%. Additionally, the removal rate of the T-P and COD was observed to be $73.8{\pm}8.0%$ and $75.0{\pm}3.8%$, respectively. Meanwhile, the removal rate of total nitrogen (T-N) was relatively low at only 24%.

• Journal of Life Science
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• v.23 no.7
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• pp.886-892
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• 2013

We investigated ethanol production from glycerol after screening of the yeast Pachysolen tannophilus ATCC 32691. For yeast to produce ethanol form glycerol, it is important that aeration is finely controlled. Therefore, we attempted to produce ethanol using a surface-aerated fermentor. When 880 ml of YPG medium (1% yeast extract, 2% peptone, 2% glycerol) was used to produce ethanol, the optimal aeration conditions for ethanol production were a surface aeration rate and agitation speed of 500 ml/min and 300 rpm, respectively. In a fed-batch culture, the maximum ethanol production and the maximum ethanol yield from glycerol (Ye/g) was 5.74 g/l and 0.166, respectively, after 90 hr using the surface-aerated fermentor.

• KSBB Journal
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• v.10 no.4
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• pp.401-405
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• 1995

An open pond type photobioreactor for mass cultivation of S. platensis was designed and the growth parameters from different cultivation processes were compared. 0.30(1/day) of specific growth rate and 1.69(g/$\ell$) of maximum cell density were obtained from batch cultivation. In fed-batch cultivation, specific growth rate and maximum cell density were estimated as 0.22(1/day) and 1.75(g/$\ell$), respectively. Maximum biomass productively from continuous cultivation was obtained as 0.44 (g/$\ell$/day). It proves that an outdoors-mass cultivation of S. platensis considering optimal environmental condition is economically feasible. In addition, the biomass productivity was studied in two different mixing systems such as agitation and air sparging methods. The biomass productivity by an agitation method was better than that in an air sparging method.

• Journal of Korean Clinical Nursing Research
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• v.18 no.2
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• pp.296-306
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• 2012

Purpose: This study was done to compare the physical injury, emotional response and unplanned self-removal of medical devices in patients with physical restraints and patients not restrained. Methods: Eighty patients admitted to the intensive care unit (ICU) of a university hospital in Seoul participated in this study. Forty patients made up each group and the group not restrained was matched with the restraint group for age and history of smoking and alcohol consumption. Data on occurrence of physical injury, intensity of anxiety, stage of agitation and unplanned self-removal of medical devices were collected by observation and medical chart review using a structured instrument. Statistical processing of collected data was done with the SPSS WIN 17.0 program. Results: The physically restrained group experienced more physical injuries and recorded significantly higher levels of anxiety and agitation than the unrestrained group. However, there were no significant differences between the groups in occurrence of unplanned self-removal of medical devices. Conclusion: Results indicate a need for critical care nurses to carefully monitor physical injuries and emotional responses of physically restrained patients and to develop nursing interventions to prevent adverse effects associated with restraint use. There is also a need to develop patient safety guidelines when using physical restraints.

• Resources Recycling
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• v.14 no.5 s.67
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• pp.18-23
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• 2005

Recovery of phosphoric acid from waste acid mixture of acetic, nitric and phosphoric acid has been attempted by using solvent extraction method. In this work, organic phosphate was used as an extraction agent. The effect of phosphate concentration, agitation speed and time on the solvent extraction of acetic and nitric acids has been investigated. The optimum concentration of phosphate for preferential extraction of acetic and nitric acids from waste acid was found to be about 50% irrespective of agitation speed and time. Purified phophoric acid was recovered from extraction residue at 1/3 of A/O ratio and 6th stage of extraction stage, which is well consistent with the value calculated by using McCabe-Thiele diagram.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.23-27
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• 2005

Electrogenerated chlorine leaching of used printed circuit board was Investigated in hydrochloric acid solution. The used printed circuit board contained about 45% of metal component, in which copper was about 84%. The leaching rate was greatly effected by current density and agitation. Utilization of electrogenerated chlorine was enhanced by increasing agitation and lowering current density. Leaching of copper was suppressed, while the minor metal elements, such as aluminum, lead, and tin, dominated the leaching at the initial stage.