• Food Science and Biotechnology
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• v.17 no.2
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• pp.379-383
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• 2008

Extraction characteristics of garlic and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 26.41% was obtained at microwave power of 146.29 W, ethanol concentration of 63.31 %, and extraction time of 5.88 min. At microwave power, ethanol concentration, and extraction time of 114.84 W, 58.83%, and 1.42 min, respectively, maximum electron-donating ability (EDA) was 72.86%. Maximum nitrite-scavenging ability was 94.62% at microwave power, ethanol concentration, and extraction time of 81.83 W, 2.65%, and 3.83 min, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 49.12% at microwave power of 34.23 W, ethanol concentration of 33.11 %, and extraction time of 4.40 min. Based on superimposition of 4-dimensional RSM with respect to extraction yield, electron-donating ability, nitrite-scavenging ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were microwave power of 0-100 W, ethanol concentration of 40-70%, and extraction time of 2-8 min.

• Korean Journal of Human Ecology
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• v.14 no.3
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• pp.433-439
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• 2005

In this study, we investigated the morphological and physical changes of hair after bleaching treatments with different concentration of hydrogen peroxide in bleaching agent (3, 6, 9, or 12%) and various treatment time (10, 30, or 60 minutes). Tresses of virgin black hair were bleached using a commercial ammonium persulfate-hydrogen peroxide solution. The tensile strength of virgin hair treated with a bleaching agent depended on the concentration of hydrogen peroxide and the treatment time. As the concentration of hydrogen peroxide in bleaching agent went high and the treatment time increased, the tensile strength of the hair increased but the extension degree decreased. The virgin hairs which were not treated by bleaching agent showed morphologically healthy cuticle, whereas the bleached hairs showed swelled and damaged cuticle patterns. The swelling of the hair and the breaks of the cuticles increased positively by the concentration of hydrogen peroxide and the treatment time. These results suggest that exposure to more concentrated hydrogen peroxide with other bleaching components may lead to more severe hair damage.

• Textile Coloration and Finishing
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• v.16 no.4
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• pp.10-18
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• 2004

In this work, Aqueous sericin solution was prepared by degumming process with electrolytic reduction water. Then, the microfiltration and ultrafiltration systems were applied to the concentration of aqueous sericin solution. The objective of this study was to select the optimum operating condition among the different pressure. The permeate flux and rejection ratio were observed with time, pressure, flow rate and concentration. and, the wastewater and permeated water quality values such as pH, BOD, COD, and NH levels were measured. In order to see the influence of electrolytic reduction water, the flux of pure water and electrolytic reduction water by PVDF22(MF) and PS100(UF) membrane was measured. In microfiltration system, the relative flux reduction decreased rapidly to 0.02 in the 30min, as the concentration polarization and gel layer formation were increased. and then the sericin concentration rejection ratio was 40%. In ultrafiltration system, the permeate flux decreased with time and concentration, and increased with the operating pressure and flow rate. Optimal condition in PS100 membrane system for sericin concentration was operating pressure 1.464kgf/$cm^24, operating flow rate $7\ell/min at\; 40^{\circ}C$. At that time, sericin concentration rejection ratio was 83% respectably. The sericin solution was concentrated from 0.1wt% solution to 0.2 wt % solution during about 2 hrs by the UF filteration membrane system.

• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.559-569
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• 2010

This study proposes an empirical method for estimating the concentration time and storage coefficient of a basin using the Nash unit hydrograph. This method is based on the analytically derived concentration time and storage coefficient of the Nash model. More fundamentally, this method recursively searches convergent number of linear reservoirs and storage coefficient of linear reservoir representing the basin given. This method is to overcome the problem of HEC-HMS to use an optimization technique to estimate the basin concentration time and storage coefficient. The proposed method was applied to the Bangrim station of the Pyungchang river basin, also found to estimate physically reasonable values.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.299-305
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

• Journal of Korean Physical Therapy Science
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• v.11 no.4
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• pp.5-10
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• 2004

This study selected 10 university football male players and repeatedly treated them as sports massage group, exercise resumption group, and stability resumption. After maximum exercise, when sport massage, exercise resumption, and stability resumption were applied during recovery, blood lactic acid concentration and $LDH_5$ isozyme concentration were examined. Finally this study obtains the following conclusion 1. There was a significant difference in both lactic acid concentration and time between groups. Besides, the cross-action on group and time was significant. 2. There was a significant difference in both $LDH_5$ concentration and time between groups. Besides, the cross-action on group and time was significant. Based on the above findings, this study suggests that sport massage resumption and exercise resumption remove blood lactic acid more quickly than stability resumption to promote recovery. That means that sport massage and exercise resumption anre very effective for lowering the level of fatigue. Thus sport massage or exercise resumption treatment is considered to have a very positive effect on player's quick recovery and it should be used aggressively in a field.

• Journal of Environmental Science International
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• v.2 no.3
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• pp.207-216
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• 1993

The concentrations of $SO_2$ and $SO_3$ were measured to estimate a new developed long time exposure $SO_2$ sampler at Onsan industrial area considering the meteorological factors from June to October, 1992. The mean concentration of $SO_3$ by $PbO_2$ method was 0.924 mg $SO_3 / 10cm^2$ $PbO_2$/day and their high values were shown in the center of the industrial area, which show potential pollution due to the increase of industrial activities and micrometeorological factors in and around the sites. As a result of statistical correlation between $SO_2$ concentration by new sampling method and $SO_3$ concentration by $PbO_2$ method in July and August, 1992, correlation coefficients were high (r=0.87, 0.91) and shown more than 0.83 value in the high concentration data set, which was arbitrarily divided into 7~10${\mu}l$$SO_2$ concentration in an attempt to further investigate these relationships. Therefore, use of new developed long time exposure TEX>$SO_2$ sampler is good for TEX>$SO_2$ measurement and valuable for estimation of air quality in the urban and industrial area. Key Words : a new developed long time exposure TEX>$SO_2$ sampler, correlation coefficients, high, $SO_2$ measurement, estimation of air Quality.

• Journal of the Korean Society of Food Culture
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• v.9 no.1
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• pp.87-93
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• 1994

This study was conducted to present a method that determine the optimum conditions for the preparation of chinese whole cabbage kimchi. After Sensory and chemical characteristics of kimchi with various salt concentration in brine, brining time and storage period at equal saltiness were measured, the optimum conditions for the preparation of chinese whole cabbage kimchi were determined with the use of the response surface methodology. The results are summarized as follows; 1. The more salt concentration in brine, the longer brining time and storage period, resulted in the lower pH and the higher titratable acidity of kimchis. As the salt concentration in brine and brining time increased, kimchi reaches at optimum titratable acidity of it within a shorter time. 2. As the salt concentration in brine and brining time increased, content of succinic acid decreased but that of lactic, acetic, and propionic acid increased. Amount of citric, malic and succinic acid decreased but that of lactic, acetic acid increased, with storage day. 3. Sensory data showed that firmness and green cabbage flavor of kimchi decreased while toughness, carbonic mouthfeel, sourness and staled flavor increased with increased salt concentration in brine, brining time and storage day. As the storage period increased, crispness of kimchi decreased. 4. The optimum conditions for the preparation of chinese whole cabbage kimchi were as follows: Optimum salt concentration in brine, brining time, and storage period were 19.5%, 3 hours and 45 minutes, and 12 hours.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.189-194
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• 2007

Kirpich formula was selected as the proper formula for calculating the concentration time at island streams. Kirpich formula can be applied for the expanded range from surface area of $0.453km^2$ and channel bed slope of $3{\sim}5%$ to surface area of $2.0km^2$ and channel bed slope of 1.5%.

• Journal of Korea Water Resources Association
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• v.42 no.3
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• pp.235-246
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• 2009

This study theoretically reviews the basin storage coefficient and concentration time using the Nash model, a simple unit hydrograph theory. First, the storage coefficient and concentration time of Nash instantaneous unit hydrograph (IUH) are derived based on their definitions, whose characteristics as well as their relationship are also reviewed. Additionally, several empirical equations of storage coefficient and concentration time commonly used in Korea are evaluated by comparing them with those for the Nash IUH. Major results of this study are summarized as follows. (1) The concentration time of Nash IUH is approximately linearly proportional to the number of linear reservoirs, but the storage coefficient non-linearly to the square root. That is, if increasing the number of linear reservoirs by four times, the concentration time becomes also increased by about four times, but the storage coefficient only about two times. This result has a special meaning to understand the effect of basin subdivision on the concentration time and storage coefficient. (2) The storage coefficient and concentration time of Nash IUH are not independent each other, so their independent estimation does not make any physical sense. As the concentration time among the two is more sensitive to the number of linear reservoirs, which should be estimated first, then the storage coefficient considering the concentration time estimated. (3) Empirical equations of concentration time can be divided into two groups, one following the linear channel theory and the other not, whose equation forms are also found to be very similar. This result indicates that the characteristic factors dominating the concentration time are very similar, indicating the possibility of its regionalization over a basin with consistent equation forms. (4) Those for storage coefficient like the Russell formulae are found to consider the physical characteristics of a basin, so their unreasonable applications could sufficiently be excluded.