• Korean Journal of Animal Reproduction
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• v.15 no.1
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• pp.7-13
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• 1991

This study was carried out to investigate the effects of pH of sperm-washing solution, sperm-washing frequency and individual bull on concentration of hydrogen ion in sperm-washed solution and sperm acrosome reaction. The results obtained were as follow. 1. When bovine sperm was washed at 4 times with SHP solution and incubated, the difference of light absorbance between sperm-washing and sperm-washed solution(${\Delta}$Ao-${\Delta}$At) was higher in 2nd sperm-washed solution than that in the other washed solutions. 2. When sperm was thrice washed with SHP solutions of pH 5.99, 6.38, 6.78, 7.10, 7.40, 7.69, 8.15, 8.45, and 8.83, ${\Delta}$Ao-${\Delta}$At was significantly increased at pH7.69 to 8.83, and ${\Delta}$Ao-${\Delta}$At in 1st sperm washed solution was significantly higher than that in 2nd and 3rd sperm washed solution. 3. When sperm of Holstein, KNC and Hereford was thrice washed with SHP solutions of pH 5.99, 6.38, 6.78, 7.10, 7.40, 7.69, 8.15, 8.45, and 8.83, Holstein showed higher ${\Delta}$Ao-${\Delta}$At of sperm Washed solution than KNC and Hereford, and ${\Delta}$Ao-${\Delta}$At in sperm washed solution was significantly increased at 7.69 for Holstein and at 8.15 for KNC and Hereford, respectively. 4. When sperm was thrice with SHP solution of pH 6.8, 7.1 and 7.4, and then incubated in mTALP of pH 7.4 for 15 minutes, in 1st and 2nd sperm washing ${\Delta}$Ao-${\Delta}$At of sperm washed solution was significantly higher at pH 7.1 and 7.4 than at pH 6.8, and the sperm acrosome reaction of pH 6.8, 7.1 and 7.4 was 49.1, 68.8 and 72.9%, respectively. The sperm acrosome reaction of pH 7.1 and 7.4 was higher than that of pH 6.8.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.65-74
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• 1998

To enhance the washing efficiency of soil polluted by hydrophobic organic compounds, the effects of electrolytes and monomeric organic additives on micelle formation and washing efficiency of mixed surfactant solutions were investigated in this study. The surface tensions and critical micelle concentrations(CMCs) of the single and mixed surfactant solutions[$POE_5$/SDS] supplemented by NaCl were measured to investigate the effects on washing efficiency, and the composition ratios of surfactants and NaCl were optimized for the efficient soil washing system. As the mixing ratio of $POE_5$/SDS was increased to 80%, the mixed surfactant with 0.01M NaCl showed more proportional increase of washing efficiency than the mixed surfactant without any salts. The 3% solution of $POE_5$ and SDS(80%/2o%) with 0.01M NaCl showed the washing efficiency of 90%. However, the washing efficiency was not enhanced by NaCl addition to the single surfactant solution of $POE_5$. The CMC of SDS(0.049%) was higher than that of $POE_5$(0.016%), but the CMCs of mixed surfactants were decreased as the mixing ratio of $POE_5$ was increased. Alcohols having longer chain and branched carbon chain were found to be desirable for the soil washing additives.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.170-179
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• 2012

We examined pretreatment methods eliminating potassium and sodium efficiently for coir bag used in hydroponics by analyzing drainage coming from coir bags. In the first experiment we investigated for six coir bags with the high market shares. The three types of pretreatment were washing coir bags with only water for 7 days (W7S0), washing with water for 4 days and further with nutrient solution for 3 days (W4S3), and washing with only nutrient solution for 7 days (W0S7). In the second experiment we tested reproducibility of the experiment results for Bio Grow and coco Mix among six coir bags used in the first experiment to verify the results. As a result, the best pretreatments for the pH stabilization were W4S3 and W0S7. The EC value of the drainage was stabilized to less than 1.0 that is the same as EC of the supply solution on the fourth day in all treatments. The nutrients of the drainage in W7S0 was stabilized in 3~4 days but calcium and magnesium were depleted. We assessed that washing longer than 4 days was waste of water. The stabilization of coir bags in W0S7 was similar to it in W4S3, but washing with the nutrient solution for 7 days seemed to be uneconomical. The reproducibility experiment for two coir bags ensured the results in the first experiment. Therefore, the pretreatment method, which is the most simple to implement and economic, seems to wash with water for 3 days and then with the nutrient solution for 1 day before planting on coir bag.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.103-111
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• 2015

Soil washing with ethylenediaminetetraacetic acid (EDTA) is highly effective in the remediation of soils contaminated with heavy metals. The EDTA recycling process is a requisite for reducing the operating cost. The applicability of Na₂S addition on the precipitation of heavy metals from the spent soil washing solution and thereby recycling of EDTA was investigated. Addition of Na₂S into the single metal-EDTA and the mixed metal-EDTA solutions ([Na₂S]/[metal-EDTA] ratio = 30, reaction time = 30 min and pH = 7~9) was highly effective in the separation of Cu and Pb from metal-EDTA complexes, but not for Ni. The Zn removal efficiency varied with pH and slightly increased upto 40% as the reaction time increased from 0 to 240 min which was longer than those for Cu and Pb. Ca(OH)₂ was subsequently added to induce further precipitation of Zn and Ni and to reduce the Na₂S dose. At the [Na₂S]/[metal-EDTA] ratio of 10, the removal efficiencies of all heavy metals excluding Ni were above 98% with the dose of Ca(OH)₂ at 0.002, 0.006 and 0.008 g into 100 mL of Cu-, Pb- and Zn-EDTA solutions, respectively. However, Ca(OH)₂ addition was not effective for Ni-EDTA solution. A further research is needed to improve metal removal efficiency and subsequent EDTA recycling for the real application in field-contaminated soils.

• Environmental Analysis Health and Toxicology
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• v.7 no.1_2
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• pp.67-87
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• 1992

Each detergent-solution in the concentration of 0.4% was prepared with four kinds of raw materials of detergents and two kinds of commercial surfactants for kitchen. LAS (Linear Alkyl Benzene Sulfonate), AOS ($\alpha$-O1effine Sulfonate), SLS (Sodium Lauryl Sulfonate) and SLE (Sodium Lauryl Ester Sulfonate) were used as the raw materials. Vegetables and fruits such as cucumber, crown daisy, lettuce, strawberry and tomatos were diped in each solution and washed 5 times in static or flow state. For the other experiments, tablewares such as porcelain, stainless bowls, glass and plastic cups were diped in each solution and washed also 5 times with cold and hot water in static or flow state. The residues of the detergents on the every steps of wash-conditions were measured. The results of this study were summarized as followings: 1. The residures of the detergents on the tested vegetables and fruits after 5 times washing were detected with the range from 0.450 to 7.120 ppm in static state and from 0.343 to 6.375 ppm in flow state. 2. The residures of the detergents on the tested tablewares after 5 times washing with cold water were observed with the range from 0.057 to 0.815 ppm in static state and from 0.066 to 0.905 ppm in flow state. 4. The residures of the detergents on the tested tablewares after 5 times washing with hot water were determined with the range from 0.061 to 0.424 ppm in static state and from 0.066 to 0.368 ppm in flow state. 4. Independent on detergent types, water temperatures and washing methods, the detergents were remained stablely on the porcelain; 0.057~0.815 ppm, on the stainless bowl; 0.061~0.905 ppm, on the glass cup; 0.0l4~0.592 ppm and on the plastic cup; 0.201~0.592 ppm.

• Korean Journal of Materials Research
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• v.10 no.6
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• pp.445-449
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• 2000

Nickel ferrite $(Ni_{0.75}Fe_{2.25}O_4$ was synthesized by co-precipitation method in order to investigate its behavior under conditions of the reactor coolant system in pressurized light water nuclear power plants. Ammonia or potassium carbonate was used as a solution pH control agent, and aqueous ammonia or potassium carbonate solution or secondary distilled water was used as a co-precipitate washing agent. The effects of the pH control agent and the co-precipitate washing agent on the production yield on the basis of the Ni/Fe molar ratio and the particle characteristics of final products were investigated by XRD, SEM, EDX and XPS. The production yield was almost congruent with that of the initial aqueous mixture in case of using potassium carbonate as a pH control agent, while in case of using ammonia, it was quite changed. The difference seemed to be due to the effects of $Ni^{2+}{\leftarrow}NH_3$complexation in the aqueous solution and of the pH of co-precipitate washing agent.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.586-591
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• 2012

The solution of maintenance decision support system for the gas turbine engine, which is currently operating in GUNSAN combined cycle power plant, was developed and is consist of online monitoring module, periodic performance trending module, optimal compressor washing interval analysis module and hot component management module. Also, GUI platform was applied to this solution for the user to monitoring the analyzed result of engine performance condition and then to make a decision of the consequent maintenance action. In online condition monitoring module, the performance degradation of engine is provided by the analysis of difference between the real time measurement data compared to exist engine performance. The optimal compressor washing interval module produced the washing interval of maximum net profit value by researching the maintenance expense and the loss profit value corresponds to the performance degradation with economic assessment algorithm. Thus, this solution support the user to enable the optimal maintenance and operation of gas turbine engine with overall analysis of engine condition and main information.

• Journal of Soil and Groundwater Environment
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• v.16 no.4
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• pp.31-37
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• 2011

The feasibility study of soil flushing was investigated to remediate lubricant oil and zinc contaminated railway soil. In this study, mixed washing agents of surfactant and inorganic acid/base were used for the simultaneous removal. The mixed washing agent of non-ionic surfactant and HCl removed 15% of the lubricant oil and 40% of zinc, respectively. Alkaline-enhanced soil washing process increased the removal of lubricant oil up to 40%. This is because alkaline solution reduced the interfacial tension between water phase and lubricant oil phase due to the soap formation reaction. To simulate in-situ soil flushing for the remediation of railroad-related contamination, two dimensional soil flushing was carried out based on the results of batch soil washing. In the soil flushing, the removal efficiencies of lubricant oil and zinc were 34% and 16%, respectively. Even though the removal efficiency was low, the mixed washing agent can remove metal and lubricant oil simultaneously.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.654-659
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• 2002

To investigate the effects of preparation conditions of encapsulating ester compounds on retention rate of core material in microcapsules prepared with sea tangle alginate, the amounts of ester compounds migrated gelling solution (1 M $CaCl_2$) and washing water from microcapsules that were prepared by adding kinds of ester compound, by controlling ratios of emulsifier to ester compounds and by differing ratios of alginates (wall material) to ester compounds (core material) were measured. Also the amount of ester compounds retained in microcapsules was measured. The higher weight molecular of ester compounds were, the lower amounts of ester compounds migrated gelling solution and washing water from microcapsules were, But its amounts retained in microcapsules were increased, The changes of ethyl caprylate amount migrated gelling solution and washing water from microcapsules prepared by increasing ratios of emulsifier to ethyl caprylate were little, but its half-lives in microcapsules during storage at 25$^{\circ}C$ were steeply increased. Increasing ratios of wall material to core material, ethyl caprylate amount migrated gelling solution and washing water from microcapsules showed 1.8$\~$$2.0\%$ and 2.9$\~$$3.5\%$ respectively but half-lives of ethyl caprylate retained in alginate microcapsules were increased.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.148-154
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• 2014

This paper describes problems of the sensorless starting of horizontal axis washing machines with direct drive and suggests solution, which was experimentally verified. Horizontal axis washing machines have very difficult conditions for the drive starting, especially at full load. Inertia of the tub and water, torque from the laundry make load torque at starting higher than rated one and sometimes even higher than the maximum torque of the motor, which makes sensorless starting extremely challenging task. This paper suggests modified open-loop starting, where control system is closed shortly after beginning at low speed and rotates the drum until laundry restructuring. To ensure proper work of the sensorless algorithm at low speed additional measures for increasing of the estimation algorithm performance have been taken. These measures include special algorithm for the drive parameters estimation, which has been developed and verified by the experimental results.