• Journal of the Microelectronics and Packaging Society
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• v.17 no.2
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• pp.63-67
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• 2010

The organic solar cells with Glass/ITO/PEDOT:PSS/P3HT:PCBM/Al structure were fabricated using regioregular poly (3-hexylthiophene) (P3HT) polymer:(6,6)- phenyl $C_{61}$-butyric acid methyl ester (PCBM) fullerene polymer as the bulk hetero-junction layer. The P3HT and PCBM as the electron donor and acceptor materials were spin casted on the indium tin oxide (ITO) coated glass substrates. The optimum mixing concentration ratio of photovoltaic layer was found to be P3HT:PCBM = 4:4 in wt%, indicating that the short circuit current density ($J_{SC}$), open circuit voltage ($V_{OC}$), fill factor (FF) and power conversion efficiency (PCE) values were about 4.7 $mA/cm^2$, 0.48 V, 43.1% and 0.97%, respectively. To investigate the effects of the post annealing treatment, as prepared organic solar cells were post annealed at the treatment time range from 5min to 20min at $150^{\circ}C$. $J_{SC}$ and $V_{OC}$ increased with increasing the post annealing time from 5min to 15min, which may be originated from the improvement of the light absorption coefficient of P3HT and improved ohmic contact between photo voltaic layer and Al electrode. The maximum $J_{SC},\;V_{OC}$, FF and PCE values of organic solar cell, which was post annealed for 15min at $150^{\circ}C$, were found to be about 7.8 $mA/cm^2$, 0.55 V, 47% and 2.0%, respectively.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.7-14
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• 1996

This experiment was carried out to investigate the growth and yield responses of hydroponically grown tomato as affected by the different substrates using perlite and mixtures with perlite. Substrates used in this experiment were perlite (fine and coarse granule), peatmoss, rice hull and carbonized rice hull. The results obtained were as follows ; The best results in terms of total fruit yield and average fruit weight obtained in the single treatment of perlite, followed by perlite mixture with rice hull and carbonized rice hull. Leaf area was also higher in the plots of perlite mixture and optimum mixing ratio of perlite, peatmoss and carbonized rice hull was determined as 5:3:2 by volume. The more the rice hull was added to the mixed substrates, the less in fruit production was observed. However, adding perlite to other substrates brought higher fruit yield. Single treatment of rice hull showed the lowest fruit yield but enhanced in soluble solids contents over 6.0 $^{\circ}$Brix at each cluster.

• Journal of Mushroom
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• v.13 no.3
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• pp.262-265
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• 2015

This study was carried out to investigated optimum mixing ratio of Korean cultivation Salvia miltiorrhiza for production of functional oyster mushroom. Mycerial growth was slow at addition of Salvia miltiorrhiza, and significant difference by increase of Salvia miltiorrhiza. Yields of fruiting body show the highest to 139.5 g/850 ml of medium which are addition 5 g/bottle of Salvia miltiorrhiza but rapid decrease by increase of Salvia miltiorrhiza. Diameter of pileus and thick of stipes were higher at addition Salvia miltiorrhiza than those of the controls. Thick of pileus and length of stipes were the highest at addition 30g, and 20 g and 30 g of Salvia miltiorrhiza. The L value of stipes were the highest at addition 20 g and 50 g of Salvia miltiorrhiza and the L value of pileus were the highest at addition 30 g of Salvia miltiorrhiza, but there was no significant difference in the a-value and the b-value.

• The Korean Journal of Food And Nutrition
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• v.19 no.2
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• pp.219-226
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• 2006

This study was carried out to optimize the extraction conditions of oleoresin from garlic and to investigate its physicochemical changes during storage at $4^{\circ}C\;and\;25^{\circ}C$. Ethanol was used as solvent for extraction of oleoresin from garlic. On the basis of yield and thiosulfinate contents, the optimum mixing ratio of garlic to ethanol, extraction temperature, time, and number of extraction repeats were found to be 1 to 2(w/v), $30^{\circ}C$, 3 hours, and three extraction repeats, respectively. The yield and thiosulfinate contents of garlic oleoresin under the above condition were 14.52% and $209.93{\mu}mol/g$, respectively. Five volatile sulfide compounds were identified by GC/MS of garlic oleoresin, i.e., diallyl disulfide, methyl allyl trisulfide, 3,4-dihydro-3-vinyl-1,2-dithiin, 2-vinyl-4H-1,3-dithiin and diallyl trisulfide. After 30 days of storage at $4^{\circ}C$, the thiosulfinate content of garlic oleoresin was $32.37{\mu}mol/g$, while there was no detectable amount of thiosulfinate in the oleoresin stored at $25^{\circ}C$. Brown color and turbidity increased significantly during the storage of garlic oleoresin at $25^{\circ}C$ as compared to storage at $4^{\circ}C$, while relatively little change in acidity was observed in the oleoresin regardless of storage temperature.

• Journal of Radiation Protection and Research
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• v.45 no.3
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• pp.142-146
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• 2020

Background: Tritium (³H) analysis in groundwater was difficult because of its low activity. Therefore, the electrolytic enrichment method was used. To improve the detection limit and for performing simple analysis, a high-volume counting vial with the available liquid scintillation counter (LSC) was investigated. Further, it was compared with a conventional 20-mL counting vial. Materials and Methods: The LSC with the electrolytic enrichment method was used ³H analysis in groundwater. A high-volume 145-mL counting vial was compared with a conventional 20-mL counting vial to determine the counting characteristics of different LSCs. Results and Discussion: When a Quantulus LSC was used, the counting window between channels 35 and 250 was used. The background count was approximately 1.86 cpm, and the counting efficiency increased from 8% to 40% depending on the mixing ratio of the volume of sample and cocktail solution. For LSC-LB7, the optimum counting window was between 1 and 4.9 keV, which was selected by the factory (Hitachi Aloka Medical Ltd., Japan) by considering quenching using a standard external gamma source. The background count of LSC-LB7 was approximately 3.60 ± 0.29 cpm when the 145-mL vial was used and 2.22 ± 0.17 cpm when the 20-mL vial was used. The minimum detectable activity (MDA) of the 20-mL vial was greater for LSC-LB7 than for Quantulus. The MDA with the 145-mL vial was improved to 0.3 Bq/L when compared with the value of 1.6 Bq/L for the 20-mL vial. Conclusion: The counting efficiency when using the 145-mL vial was 27%, whereas it was 18% when using the 20-mL vial. This difference can be attributed to the vial volume. The figure of merit (FOM) of the 145-mL vial was four times greater than that of the 20-mL vial because the volume of the former vial is approximately seven times greater than that of the latter. Further, the MDA for ³H decreased from 1.6 to 0.3 Bq/L. The counting efficiency and FOM of LSC-LB7 was slightly less than those of Quantulus when the 20-mL vial was used. The background counting rate of the Quantulus was lower than that of the LSC-LB7.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.740-747
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• 2015

This research was performed to evaluate the feasibility of in situ soil flushing for TPH-contaminated soil remediation. It was conducted in batch test as fundamental research for in situ soil flushing. The 30% of initial TPH concentration was removed by shaking only in batch test. The removal efficiency of TPH in case of groundwater as surfactant dilution solution was approximate 2~6% lower than that of distilled water. Mixing ratio of soil to surfactant solution did not practically effect on the TPH removal efficiency. In the experiment of using single or mixed surfactant solution with 0.1~4.0 wt%, Tween-80, SWA-1503, SWA-1503+SDS showed averagely over 80%. It was determined that the optimum surfactant concentration was 0.1 wt% because there was no significant difference between concentrations of 0.1~4.0 wt%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.92-97
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• 1997

Beverages using mountain edible herbs(MEH) were formulated by determining optimum ratio of juices of MEH to several other ingredients. Fermented beverages were made by mixing juices(1 volume) fermented with Lactobacillus helverticus with syrup(3 volumes), followed by homogenization and flavoring . The general analysis and quality change of the beverages during storage were Peformed. The analysis of the beverages showed that the pH of Synurus deltoides and Cirsium sctidens were 3.8 and 3.7, titratable acidities were 0.50 and 0.49, optical densities were 1.201 and 1.119, respectively, The pH and color were not significantly changed when Synurus deltoides and Cirsium sctidens were stored at room temperature and 37$^{\circ}C$ for 6 months. The pH of Synurs deltoides beverage ranged 3.95~3.96 and pH of Cirsium sctidens was 3.83~3.95 at room temperature and 3.87~3.98 at 37$^{\circ}C$, respectively. The analysis of fermented beverages showed that pHs of Synurus deltoides and Cirsium sctidens were 3.65 and 3.70, titratable acidities were 0.57 and 0.60. Solids-non-fat were 3.2 and 3.1, and total counts of lactic acid bacteria were 2.5$\times$10$^{8}$ and 4.0$\times$10$^{8}$ , respectively. The changes of pH and titratable acidities stored at 4$^{\circ}C$ for 15 days were 3.39~3.56 and 0.61~0.81 for Synurus deltoides and 3.48~3.67 and 0.60~0.78 for Cirsium sctidens, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.104-110
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• 2001

In this study, the effect of physico-chemical variables on sludge conditioning was determined to enhance dewaterability of effluent produced from the thermophilic anaerobic digestion of food waste. The gas production rate and methane content during the anaerobic digestion of food waste were $1.1m^3/kg$ VS and 63%, respectively, and the biodegradability of volatile solids was 87.5%. The concentrations of CODcr, TKN and TP of effluent from digestor were 18,500mg/L, 2,800mg/L, and 582mg/L, respectively. At the jar test to screen the flocculant for the dewatering of effluent from digestor, $FeCl_3$ and strong cationic polymer were effective on making flocs in the effluent. The condition of flocculation of effluent were 500mg/L of $FeCl_3$ and 50-100 mg/L of strong cationic polymer, respectively. As the result of measuring of dewaterability potential of effluent to determine the mixing ratio between $FeCl_3$ and polymer by capillary suction time(SCT), optimum condition was 500mg/L of $FeCl_3$ and 80mg/L of strong cationic polymer.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.606-614
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• 2019

A mixing ratio of the oil in water (O/W) emulsion of palm oil and the non-ionic surfactant (Tween-Span type) possessing different hydrophile-lipophilie balance (HLB) values was evaluated in this work. An optimum condition was determined through analysis of main and interaction effects of each quantitative factor using central composite design model-response surface methodology (CCD-RSM). Quantitative factors used by CCD-RSM were an emulsification time, emulsification speed, HLB value and amount of surfactant. On the other hand, the reaction parameters were the viscosity and mean droplet size of O/W emersion. Optimized conditions obtained from CCD-RSM were the emulsification time of 12.7 min, emulsification speed of 5,551 rpm, HLB value of 8.0 and amount of surfactant of 5.7 wt.%. Ideal experimental results under the optimized experimental condition were the viscosity of 1,551 cP and mean droplet size of 432 nm which satisfy the targeted values. The average error value from our actual experiment for verifying the conclusions was below to 2.5%. Therefore, a high favorable level could be obtained when the CCD-RSM was applied to the optimized palm oil to water emulsification.

• Elastomers and Composites
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• v.38 no.1
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• pp.57-64
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• 2003

Metal oxide(MgO) was added to FKM rubber in order to develop automotive fuel hose which ran show elastic characteristics under extreme condition. Cure characteristics, physical properties, thermal resistance and fuel resistance of FKM compounded rubber with MgO were investigated. MgO was mixed to FKM rubber materials within the range of $0{\sim}20phr$. From the test results of rheological properties and Mooney viscosity, the $t_{s2}$, $T_{c90}$ values increased as the MgO contents increased in FKM rubber compounding. Hardness and 100% modulus of FKM compounded rubber slightly increased, but tensile strength and elongations at break slightly decreased. From the test results of thermal resistance of rubber specimens at 130, 150, and $170^{\circ}C$ for 70 hrs, the changing rate of physical properties was found to be relatively small. Fuel resistance tests were carried out for fuel A, B, C and D at $40^{\circ}C$ for 70hrs, and the results showed that the changing rate in physical properties was found to increase from Fuel A to D, Furthermore thermal properties of FKM compounded rubber containing MgO were also investigated by using TGA/DSC. The optimum mixing ratio of additive to FKM rubber to get the maximum effect on thermal resistance and fuel resistance, within the range of desirable specification for rubber material, was determined to be 6 phr for MgO.