• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.106-111
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• 2021

In this study, an ultrasound-assisted micellar extraction process was developed to efficiently purify the anticancer substance paclitaxel from the plant cell Taxus chinensis. The problem of many extraction steps and long phase separation time in the traditional micellar process could be dramatically improved. The highest paclitaxel yield (~96%, extracted twice) was obtained at 180 W of ultrasonic power and 1.5 h of ultrasonic irradiation time, which was 24.7% higher than that of the traditional method. In addition, the partition coefficient (K) showed a maximum value (24.0) at 180 W of ultrasonic power and 1.5 h of irradiation time. There was no significant difference in the purity of paclitaxel, and the purity of initial paclitaxel (6.81%) increased to 22.0% after purification. Compared to the traditional method, the phase separation time of the back extraction decreased by 40.7-56.2% (ultrasonic power 80 W), 46.3-67.6% (ultrasonic power 180 W), and 51.9-67.6% (ultrasonic power 250 W), respectively. The phase separation time decreased as the ultrasonic power (80-250 W) and irradiation time (0.5-2.5 h) increased.

• KSBB Journal
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• v.10 no.2
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• pp.137-142
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• 1995

When Escherichia coli W, which is able to utilize sucrose as a carbon source, harboring a high-copy-number plasmid (pSYL105) containing the Alcaligenes eultrophus polyhydroxyalkanoate(PHA) biosynthetic genes was cultured in a defined medium, the final poly(3-hydroxybutyric acid), PHB, concentration obtained was as low as $0.21g/\ell$. Ten different complex nitrogen sources were, therefore, examined for their ability to enhance PHB synthesis when supplemented to a defined medium. Addition of tryptone, casamino acids, casein hydrolysate, or soy bean hydrolysate enhanced PHB synthesis most significantly, resulting in more than 10 times higher PHB concentration compared with that obtained in a defined medium. Furthermore, PHB yield on sucrose was also increased by more than a 10 fold by the addition of these complex nitrogen sources, which suggested that PHB might be efficiently produced by the recombinant E. coli W(pSYL105) using sucrose as a carbon source.

• Journal of the Korean Ceramic Society
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• v.30 no.8
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• pp.629-634
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• 1993

Dielectric and electrostrictive properties of 0.99Pb(Mg1/3Nb2/3)O3-0.01Pb(Mn2/3W1/3)O3 system using KCl-NaCl salts have been investigated as a function of the amount of excess MgO. For the specimens calcined at $700^{\circ}C$ for 1h and then sintered at 115$0^{\circ}C$ for 4h, the perovskite phase and the relative density were about 98% and 95%, respectively. With the addition of excess MgO up to 10mol%, the dielectric constant and the electrostrictive strain increased due to the increase of density and grain size, and these properties were degraded by the further addition of excess MgO. For the 10mol% excess MgO added specimen, the maximum electrostrictive strain, Xmax, and the electrostrictive coefficient, Q11, were 4.5$\times$10-4, 3.5$\times$10-2m4/C2, respectively. These results were correlated with the property of PMW and microstructure.

• The Journal of Society for e-Business Studies
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• v.22 no.2
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• pp.19-38
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• 2017

The core of the smartphone business environment is changing from H/W to S/W and with it the paradigm of an enterprise's base of competition is changing from H/W to service. In accordance with this paradigm, in this study we have determined H/W, S/W and telecommunication service as smartphone business factors. The purpose of this study is to first analyze the influence business factors has on consumer satisfaction and customer loyalty. Secondly, to analyze the influence switching cost has on customer loyalty. As a result, the factor that has a notable influence on customer satisfaction turned out to be the H/W factor. On the other hand S/W factor and communication service turned out to have very little influence. In addition, the factors influencing customer loyalty turned out to be H/W factor and S/W factor. Telecommunication service did not have much of an influence. Customer satisfaction turned out to act as mediation effect between H/W factor and customer loyalty. Like the result of other preceding researches, switching cost turned out to have a significant influence on customer loyalty. This study differs from other studies in that while other existing studies analyzed H/W, S/W and communication service separately, this study analyzed the influence H/W, S/W and communication service as a whole has on customer satisfaction and customer loyalty. We speculate that the results of this study would provide some insight both in an academic and practical level for stagnant smartphone industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.927-933
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• 2008

The quality of Gangjung added with detoxified stem bark of Rhus verniciflua (RVSB) extract ($0{\sim}7%$, w/w) during room temperature storage ($25^{\circ}C$, 60 days) was investigated. The moisture content of Gangjung slightly decreased as the storage period increased, especially Gangjung at concentrations between $0{\sim}1%$, $3{\sim}5%$, and 7% decreased after 30, 40 and 50 days of storage, respectively. No significant differences in the hardness were found among the control and experimental samples. However, the peak number of Gangjung containing detoxified RVSB extract at concentrations of $0{\sim}3%$ significantly decreased after 60 days of storage, while that of Gangjung with 5% and 7% addition were not changed during storage. The acid, peroxide and TBA values of Gangjung increased as the storage period increased but the acid value was significantly lower for the Gangjung prepared with 7% (w/w) detoxified RVSB extract after 40 days of storage. Moreover, from 40 to 60 days of room temperature storage, peroxide value significantly decreased as the concentrations of detoxified RVSB extract increased and TBA value significantly decreased when the addition of detoxified RVSB extract was over 3% (w/w). These results suggest that the physical texture of Gangjung improved and lipid oxidation was reduced by the addition of detoxified RVSB extract.

• Food Science and Preservation
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• v.18 no.1
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• pp.33-38
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• 2011

We investigated the quality characteristics of cookies prepared after addition of various concentrations of used coffee grounds (0%, 1%, 3%, and 5%, all w/w) as a substitute for flour. As coffee grounds concentration rose, decrease in the pH of cookie dough was evident. In terms the water-holding capacity of dough, cookies prepared 3% (w/w) coffee grounds yielded the highest value. With an increase in coffee grounds concentration, the color a value rose, but the L and b values fell. The gelatinization temperature became higher, but both peak viscosity and 15 min-height values declined. The spread and loss ratios decreased but the leavening rate rose significantly with elevation of coffee grounds concentration. The hardness of cookies rose but slightly, as coffee grounds concentration rose. Upon sensory evaluation of all of appearance, flavor, and overall preference, cookies prepared with addition of used coffee grounds were superior to those without grounds, whereas those prepared using 1%-3%(w/w) coffee grounds showed the highest overall acceptability. Thus cookies made using coffee grounds can be economically competitive. In addition, the ingredients of coffee powder and used coffee grounds were shown to be very similar, except that coffee grounds contain 15-fold less caffeine than dose coffee powder. As health concerns are popular today, the use of coffee grounds to manufacture processed food may be acceptable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.373-377
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• 2006

The effect of chlorella addition on the quality characteristics of processed cheese was investigated. Chlorella processed cheese was prepared in the different ratio of chlorella (0.5% (w/w) and 1.0% (w/w)). Chlorella processed cheese was stored at $10{\pm}1^{\circ}C$ and evaluated for the quality characteristics including general composition, pH, the number of microorganisms, oiling off, meltability, rheological properties, color, and sensory evaluation. Contents of moisture, protein, fat, fat in dry matter, and pH values were not different from those of control cheese. Microorganisms were not detected. The degree of oiling off showed no significant difference, but meltability decreased significantly (p<0.05). Hardness and springiness gradually increased significantly (p<0.05), while cohesiveness gradually decreased significantly (p<0.05). The L (lightness) values and the a (redness) values decreased with increasing chlorella contents, but the b (yellowness) values increased with increasing chlorella contents, so color expressed yellowish green. Compared to control cheese made by conventional way, QDA scores of color and mouthfeel of chlorella processed cheese were significantly higher (p<0.05) and the most favorite quality characteristics were shown in the processed cheese with 0.5% (w/w) chlorella (CPC1). These results suggested that health-oriented chlorella processed cheese would be made by the addition of the chlorella.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.425-431
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• 2007

The quality characteristics of Gangjung added with detoxified Rhus verniciflua stem bark (RVSB) extract, as well as the changes that occurred in the product during accelerated storage ($60^{\circ}C$, 24 hr), were investigated. The expansion rate of Gangjung was not significantly different (p < 0.05). The L-value of the Gangjung with added detoxified RVSB extract was higher than the control, while the a-value decreased as the addition levels of the detoxified RVSB extract increased. The b-value was highest for the Gangjung prepared with 7% (w/w) detoxified RVSB extract. The moisture content of the Gangjung decreased as the storage period increased, but the addition of detoxified RVSB extract (p < 0.05) did not significantly change this effect. We found no significant difference in the hardness of the Gangjung within the concentration range of 0-7% (w/w) detoxified RVSB extract, and the peak number slightly decreased as the storage period increased. After 16 hr of storage, the acid value was significantly lower for the Gangjung containing detoxified RVSB extract at concentration between 5-7%. Furthermore, after 12 hr of accelerated storage, peroxide and TBA values significantly decreased with additions of detoxified RVSB extract that were over 3% (w/w). These results suggest that the physical texture of Gangjung did not improve by the addition of detoxified RVSB extract; however, its rate of lipid oxidation was reduced.

• Food Science and Preservation
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• v.16 no.5
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• pp.772-781
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• 2009

We investigated the effects of Alaska pollack addition on the quality of Kimchi during 20 days of fermentation at 10C. Alaska pollack was added to salted cabbage at concentrations of 0%, 6%, 12%, or 18% (all w/w). The quality characteristics determined were pH, acidity, salinity, reducing sugar content, color, free amino acid level, and lactic acid bacterial counts, at 4 d intervals over 20 d, during progressive fermentation at constant temperature (10C). Changes in pH, acidity, and reducing sugar content during fermentation were increased when Alaska pollack was added, whereas salinity decreased. Total lactic acid bacterial counts achieved maximum levels on day 8 for Kimchi with 18% (w/w) Alaska pollack, and the other Kimchi samples attained their highest values on day 12. In terms of color, the L, a, and b values of Kimchi rose with addition of Alaska pollack. The free amino acid content of Kimchi increased as the level of added Alaska pollack rose but gradually fell as fermentation progressed. Upon sensory evaluation, Kimchi with 6% (w/w) Alaska pollack scored highest in terms of appearance, texture, taste, and overall acceptance. In conclusion, our results indicate that Alaska pollack has a positive effect on the quality of Kimchi, increasing the content of free amino acids.

• Journal of IKEEE
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• v.25 no.2
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• pp.267-272
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• 2021

Recently, attention has been focused on renewable energy and carbon neutrality to resolve fossil energy depletion and environmental problems. In addition, high-rise urban buildings and an increase in building energy are rapidly increasing. There are many restrictions on installing solar power in urban areas. In addition, as buildings become taller, a lot of low-light environments in which shade is formed occur. Therefore, in this study, we intend to develop a power plant capable of generating electric power in an outdoor low-light environment and indoor lighting environment. The power plant in a low-light environment used a dye-sensitized solar cell. A unit cell and a 20cm×20cm module were manufactured, and the electrical characteristics of the power plant were measured using light sources of LED, halogen lamp, and 3-wavelength lamp. The photoelectric conversion efficiency of the unit cell was 17.2%, 1.28%, 19,2% for each LED, halogen lamp, and 3-wavelength lamp, and the photoelectric conversion efficiency of the 20cm×20cm module was 10.9%, 8.7%, and 11.8%, respectively. In addition, the maximum power value of the module was 13.1mW, 15.7 mW, and 14.2 mW for each light source, respectively, confirming the possibility of power generation in a low-light environment