• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1131-1137
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• 1997

The production rates of leavening gases and textures of cookies were investigated with various chemical leavening agents(baking powders). The chemical leavening agents could be divided into three group of a fast-acting group such as potassium bicarbonate, tartaric acid, aluminium ammonium sulfate, and fumaric acid, a slow-acting group such as ammonium bicarbonate, sodium bicarbonate, $glucono-{\delta}-lactone$, and ammonium chloride. and a double-acting group such as anhydro monocalcium phosphate, disodium dihydrogenpyrophosphate, and aluminium potassium sulfate according to the different production rate of gases. The leavening rate of ammonium bicarbonate, which was the highest of all leavening agents used in this experiment, was 131.25%. But its after-taste in a cookie was not good due to the residual ammonia. $Glucono-{\delta}-lactone$ only had no after-taste. The higher leavening rate, the more peaks in texture profile graph. Ammonium bicarbonate showed the most peaks in this experiment. It was found that the number of peak had correlation with brittleness of cookies $(r^2=0.8176)$ and brittleness of cookies was different as to various chemical leavening agents.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1304-1309
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• 2006

In this study, removal efficiencies of treatment processes with C. tracer which is similar to the characteristics of Cryptosporidium were investigated. The highest removal efficiency of C. tracer was 97.16% when the input dose of PACI(Poly aluminium chloride, $Al_2O_3$(10%)) was 10 mg/L. The higher turbidity and SS removal efficiencies were, the more C. tracer cohesion efficiency increased. Also when pH of the raw water was high, removal efficiency of C. tracer increased. As the correlationship($R^2$) between effluent turbidity after coagulation-precipitation and removal efficiency of C. tracer was 0.9506, removal efficiency of Cryptosporidium could be evaluated by effluent turbidity after coagulation-precipitation. Also the range of C. tracer removal efficiency by sand filtration was $94.00{\sim}95.83%$ and the correlationship($R^2$) between effluent turbidity after filtration and removal efficiency of C. tracer was 0.8704. Therefore, when filtration-effluent turbidity is good under the optimized coagulation condition, removal efficiencies of Cryptosporidium by coagulation-precipitation, sand rapid filtration and sand rapid filtration after coagulation-precipitation are estimated as 1.55 log(97.16%), 1.38 log(95.83%) and 2.31 log(99.51%) respectively.

• Corrosion Science and Technology
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• v.10 no.4
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• pp.109-117
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• 2011

The Korean Peninsula is located in the middle latitude of the northern hemisphere and has a clear 4-seasons and shows the typical temperate climate. Because of seasonal winds, it is cold and dry by a northwestern wind in the winter and it is hot and humid by a southeast wind in the summer. Also, temperature difference between the winter and the summer is large and it shows a rainy season from June to July but recently this regular trend may be greatly changed by an unusual weather phenomena. Since the Peninsula is east high west low type, the climate is complicated too. Because these geographical and climate characteristics can affect the properties of corrosion of metals and alloys, a systematic research on atmospheric corrosion in the Peninsula is required to understand and control the corrosion behavior of the industrial facilities. This paper analyzed the atmospheric corrosion factors for several environments in the Korean Peninsula and categorized the corrosivity of atmospheric corrosion of metals and alloys on the base of the related ISO standards. Annual pH values of rain showed the range of 4.5~5.5 in Korean Peninsula from 1999 to 2009 and coastal area showed relatively the low pH's rain. Annual $SO_2$ concentrations is reduced with time and its concentrations of every major cities were below the air quality standard, but $NO_2$concentration revealed a steady state and its concentration of Seoul has been over air quality standard. In 2007, $SO_2$classes of each sites were in $P_0{\sim}P_1$, and chloride classes were in $S_0{\sim}S_1$, and TOW classes were in ${\tau}_3{\sim}{\tau}_4$.That is, $SO_2$ and chloride classes were low but TOW class was high in Korean Peninsula. On the base of these environmental classes, corrosivity of carbon steel, zinc, copper, aluminium can be calculated that carbon steel was in C2-C3 classes and it was classified as low-medium, and zinc, copper, and aluminium showed C3 class and it was classified as medium.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.799-806
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• 2017

The potential use of modified clays in the adsorption of vapor phase benzene and toluene was investigated. The modified clays OC-CPC, IOC, and Al-PILC were prepared for comparative purposes and were characterized using infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. It was confirmed the intercalation of the aluminium pillar in IOC and Al-PILC, as well as the introduction of cetylpyridinium. The adsorption studies showed a great affinity of benzene and toluene for OC-CPC due to the hydrophobic character that resulted and also to the increase in the interlaminar distance. IOC showed a lower affinity for the benzene and toluene, followed by Al-PILC. Natual clay had no affinity for benzene and toluene due to its hydrophilic nature. Clay materials having a laminar structure can be chemically modified, changing their physiochemical characteristics, such as interlaminar distance, surface area, pore size, and chemical affinity. In this study, it was focused on obtaining modified clays to be used for the adsorption of volatile organic chemicals.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.590-596
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• 2012

Enhanced coagulation is best available technologies to treat NOM in water to produce clean drinking water. In this research, the comparison experiments between conventional coagulation (CC) and enhanced coagulation (EC) using 4 type coagulants i.e., ferric chloride, aluminium sulphate (alum), poly aluminium sulphate organic magnesium (PSOM) and poly aluminium chloride (PACl) were performed in terms of surrogate parameters such as dissolved organic carbon (DOC), trihalomethane formation potential (THMFP), haloacetic acid formation potential (HAAFP) and zeta potential variation in order to find out the most effective coagulant and conditions to fit Nakdong River water. When applied to EC process, the turbidity removal efficiency did not increased gradually compared to the CC process when adding coagulants. Furthermore, the removal efficiency of turbidity became decreased much more as coagulants were added increasingly whereas the removal efficiency of DOC, THMFP and HAAFP became increased by 13~18%, 9~18% and 9~18% respectively compared to the CC process. The characteristics of turbidity removal showed relatively high removal efficiency considering the pH variation in entire pH range when using $FeCl_3$ and PACl. Additionally, in case of alum and PSOM steady removal efficiency was shown between pH 5 and pH 8. In terms of DOC surrogate the coagulants including 4 type coagulants indicated high removal efficiency between pH 5 and pH 7. The removal efficiency of dissolved organic matter (DOM) in EC between less than 1 kDa and more than 10 kDa augmented by 11~21% and 16% respectively compared to the CC process. The removal efficiency of hydrophobic and hydrophilic organic matter proved to be increased by 27~38% and 11~15% respectively. In conclusion, the most effective coagulant relating to EC for Nakdong River water was proved to be $FeCl_3$ followed by PSOM, PAC and alum in order.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.145-151
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• 2002

Molinate, a thiolcarbamate herbicide widely used for control weeds in paddy soil, has been suspected for a possibile transportation into surface water due to its relatively high solubility in water. This study was performed to know that how much molinate could be removed during treatment processes for drinking water. The removal effciency of molinate in water was negligible in treatment process of polyaluminium chloride for coagulation. Molinate was gradually decreased up to 60.2% during contact time of 4 hours when chloride, an disinfectant used in water treatment system was treated. And in an hour treatment of ozone, molinate removal ranged $28.9%{\sim}58%$ However by treatment system of granular activated carbon, molinate was removed 93.9 to 100% at all concentrations used with a range of concentrations of granular activated carbon treated. The removal effciency of whole system simulated with removal efficiencies of molinate in each step of treatment processes was 99.5%. Therefore, if molinate happen to come into water treatment facilities, it could be removed effectively through the treatment processes.

• Analytical Science and Technology
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• v.24 no.6
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• pp.477-483
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• 2011

This work is on the synthesis of EMI-$BF_4$ (1-ethyl-3-methylimidazolium tetrafluoroborate) and purification of spectroscopic grade using aluminium oxide method, activated charcoal method, and liquid/liquid fractional extraction method in order to make supercapacitor finally. But the aluminum oxide method and the activated charcoal method were not suitable for obtaining high-purity ionic liquids. The liquid/liquid fractional distillation method turned out that as the concentration of solvent ($H_2O$) was increased, the higher purity of EMI-$BF_4$ was obtained and the electrical capacity of this compound was increased to higher value. When the solvent was changed to from methylene chloride to 1,2-dichloroethane, the higher purity of EMI-$BF_4$ was obtained.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.317-320
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• 1997

In the water purification plant, chemicals are injected for quick purification of raw water. It is clear that the amount of chemicals intrinsically depends on the water quality such as turbidity, temperature, pH and alkalinity etc. However, the process of chemical reaction to improve water quality by the chemicals is not yet fully clarified nor quantified. The feedback signal in the process of coagulant dosage, which should be measured (through the sensor of the plant) to compute the appropriate amount of chemicals, is also not available. Most traditional methods focus on judging the conditions of purifying reaction and determine the amounts of chemicals through manual operation of field experts or jar-test results. This paper presents the method of deriving the optimum dosing rate of coagulant, PAC(Polymerized Aluminium Chloride) for coagulant dosing process in water purification system. A neural network model is developed for coagulant dosing and purifying process. The optimum coagulant dosing rate can be derived the neural network model. Conventionally, four input variables (turbidity, temperature, pH, alkalinity of raw water) are known to be related to the process, while considering the relationships to the reaction of coagulation and flocculation. Also, the turbidity in flocculator is regarded as a new input variable. And the genetic algorithm is utilized to identify the neural network structure. The ability of the proposed scheme validated through the field test is proved to be of considerable practical value.

• Journal of the Korean Home Economics Association
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• v.41 no.2
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• pp.107-121
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• 2003

This study was discussed the dyeing of wool and nylon fabrics with Chinese Scholar Tree extract. The extracts of Chinese Scholar Tree was prepared in the condition of heating at $95{\pm}5C$, for 1 hour and cooling to 40C. And then the extracts of color matter treate with vacuum concentration at $60{\pm}2^{\circ}C$, 30mmHg and dried with spray dryer. The dyeing of wool and nylon fabric in this experiment was also employed the mordant dyeing method such as pre-mordant, post-mordant and simultaneous mordant method. The mordanting agents used in this study were as followings ; aluminium potassium sulfate, copper(II) acetate monohydrate, chromium potassium sulfate$.$$7H_2O$, Tin(II) chloride dihydrate, iron(II)sulfate $7H_2O$. For an evaluation of the dyeing property of the mordanting agents, the pre-mordant method, the repeat dyeing and the fastness of the light, dry cleaning, washing and rubbing measured respectively. From the results of the dye absorption, the optimum dyeing condition of the wool and nylon fabrics with Chinese Scholar Tree extract is at 80C dyeing temperature for 60 minutes. The optimum concentration of mordanting agent is Al, Cr, Sn 1%, Fe, Cu 2% solution. In general, the fastness property of the dyed wool and nylon fabrics had a comparatively high grade.

• Solar Energy
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• v.12 no.1
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• pp.59-71
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• 1992

The purposes of the present study are to investigate the characteristics of heat storage and emission of the PCM($CalCl_2{\cdot}6H_2O$) panel, and to analyze the distribution of indoor air temperature in a floor heating space with PCM panels for the heating system. Two identical unit test cells sized $1.8m^W{\times}1.8m^L{\times}1.8m^H$ were built and installed with specially designed aluminium Ondol-panels. It held 1.2kg of calcium chloride hexahydrate(CCH). It was found that PCM panels could reduce the indoor air temperature fluctuations and maintain the phase changing temperature for considerably long duration, $2{\sim}3$ times longer in heating hour over no-CCH one. When the elapsed time was 6 hours, the average temperature difference between PCM panel and Ondol panel was $7.7^{\circ}C$.