• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.33-39
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• 2001

The split application of a nitrogen fertilizer was applied at the levels to 3, 4, 5, 6 and 7 time. The results of yield and quality of Okro tea are summarized as follows: Among five treatments, the growth and yield were somewhat more excellent in the five time split treatments compared with other treatments. The chemical components such as total nitrogen, total amino acid and vitamin C were somewhat higher in the five time split treatment compared with other treatment. However, the content of components such as tannin, caffeine, chlorophyll were not different among plots of $4{\sim}7$ time split application except three time split application manuring. The content of fatty acid was producted $2,888{\sim}2,933mg/100g$. Especially, the content of oleic acid, linoleic acid and linolenic acid was the higheat in the five time split application. Sixteen kinds of free amino acid including theanine as a good taste component of Okro tea were isolated and measured by HPLC. Theanine in the five time split application was higher with value of $72{\sim}513mg/100g$ than in other treatment. In scoring test, tea appearance and interal qualities of 3 time split application become lower than any other treatment as 80.2 point, while five time application had the highest with 84.7 point. Conquently, those results meant that five time split application was optimum split application of fertilizer for high yield and good quality of Okro tea.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.377-380
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• 2015

In this paper, we have investigated the optimization of $I_2$ recovery process from $NH_4I$ solution, which is generated as by-product during the amination reaction of p-diiodobenzene (PDIB) for p-phenylenediamine (PPD) synthesis. The recovered $I_2$ is then recycled as a raw material for PDIB synthesis. We have employed a cation exchange resin to recover $I_2$ from $NH_4I$ sample solution, and determined the breakthrough point and exchange capacity from the breakthrough curve. Furthermore, we have suggested optimum conditions of our $I_2$ recovery process by measuring the purity and yield of recovered $I_2$ with respect to the concentrations of $NH_4I$ and oxidant ($H_2O_2$) solutions, the oxidation time, and the temperature of drying process. Finally, the yield and purity as high as 94.96% and 96.65%, respectively were obtained by reusing the residual solution still containing unrecovered iodide ions.

• Journal of the Korean Institute of Gas
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• v.17 no.6
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• pp.8-14
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• 2013

In this study, characteristics of the geometric design changes of plasma reformer for LPG fuelled vehicles were studied. To improve the yield of hydrogen, reformer 1st, and 2nd were designed. Secondary reformer compared to the primary reformer to increase the volume of the rear part of reformed gas having passed through the plasma and increased reaction time. To compare reforming results of two reformers, various experimental conditions such as, from partial oxidation to total oxidation conditions $O_2/C$ ratios, and total flow rate of 20, 30, 40, 50 lpm conditions, were varied. Results showed that with increasing $O_2/C$ ratios, LPG conversion rate increased, decreased hydrogen selectivity and hydrogen yield optimal point existed and secondary reformer 4.5 times larger than the primary reformer at the same flow rate to 4~14% increase in the yield of hydrogen.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.9
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• pp.882-888
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• 2002

This paper proposed a bias stability circuit that compensates the degradation of MMIC's performance for the variation of the process and temperature. The proposed bias circuit proved the superior effect compared with the conventional bias circuit using the constant current source. It designed and fabricated simultaneously two amplifier on one layout for comparison in same conditions. One is amplifier with conventional bias circuit using constant current source and the other is amplifier with proposed bias stability circuit. The chip was measured the microwave performances under process variation that classed the level NOM, MIN and MAX. The amplifier with a conventional bias circuit using constant current source has 6.4 dB gain variation and 7 mA Ids variation at 1.8 GHz, but the amplifier with the proposed bias circuit has the 2.1 dB gain variation and 3 mA Ids variation. As the result, MMIC having the proposed bias circuit shows the superior compensation of the quiescent point than the MMIC having the conventional bias circuit under the variations of the process and temperature and can improve the yield of the MMIC. The fabricated chip size is 1.2 mm $\times$ 1.4 mm.

• Earthquakes and Structures
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• v.9 no.4
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• pp.831-849
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• 2015

Seismic-design procedures for walls require that the confinement in the critical (plastic hinge) regions should extend over a length in the compression zone of the cross section at the wall base where concrete strains in the Ultimate Limit State (ULS) exceed the limit of 0.0035. In a performance-based framework, confinement is linked to required curvature ductility so that the drift demand at the performance point of the structure for the design earthquake may be met. However, performance of flexural walls in the recent earthquakes in Chile (2010) and Christchurch (2011) indicates that the actual compression strains in the critical regions of many structural walls were higher than estimated, being responsible for several of the reported failures by toe crushing. In this study, the method of estimating the confined region and magnitude of compression strain demands in slender walls are revisited. The objective is to account for a newly identified kinematic interaction between the normal strains that arise in the compression zone, and the lumped rotations that occur at the other end of the wall base due to penetration of bar tension yielding into the supporting anchorage. Design charts estimating the amount of yield penetration in terms of the resulting lumped rotation at the wall base are used to quantify the increased demands for compression strain in the critical section. The estimated strain increase may exceed by more than 30% the base value estimated from the existing design expressions, which explains the frequently reported occurrence of toe crushing even in well confined slender walls under high drift demands. Example cases are included in the presentation to illustrate the behavioral parametric trends and implications in seismic design of walls.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.387-398
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• 2010

SWAT model would be applied to evaluate the pollutant removal capacity with various best management practices (BMPs) in Kyongan stream watershed which plays an important role in water quality conservation and improvement of Paldang reservoir. The methods for the representation of various BMPs scenarios with SWAT is developed and evaluated. Riparian buffer strip, agricultural conservation practices to reduce fertilizer, sediment, and nutrients occurring from farm field (Grassed swale, Contour farming/Parallel terrace, Field border, Farm retention pond, Grade stabilization structure), and washland such as wetland and pond to extend detention and improve water quality are represented in SWAT. And to represent the expansion of existing Waste Water Treatment Plants (WWTPs) in Soil and Water Assessment Tool (SWAT), reduction effect for point source pollutants was simulated. As the result of simulation, the removal rates of SS, TN, TP from scenarios of Kyongan stream watershed are the average annual SS yield by 5.2% to 69.2%, the average annual TN yield by 0.5% to 26.3%, and the average annual TP yield by 1.3% to 32.5%, respectively. This study has demonstrated that the SWAT is a very reliable and useful water quality and quantity assessment tool, and the BMPs representation in SWAT for watershed management is able to effectively simulate in Kyongan Stream watershed.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.423-429
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• 2015

This study was conducted to evaluate the effects of reduced nitrogen (N) and potassium (K) fertigation as additional fertilizer on tomato yield and nutrient contents in excessively nutrients-accumulated soil. Shoot and root dry weights (DW), dry matter rate for shoot, root and fruit and number of fruit in both AF50 and AF100 (50 and 100% levels of additional fertilizer) treatments were increased in comparison with those in AF0 (0% level of additional fertilizer) treatment. In case of nutrient uptake by tomato, nitrogen, phosphorous (P) and potassium contents in all tomato parts (leaf, stem, root and fruit) in AF50 and AF100 treatment were lower than those in AF0 treatment. On the contrary, soluble sugar and starch contents in all tomato parts in AF50 and AF100 were higher than those in AF0 treatment. There were differences between AF0 and AF50 or AF100 in tomato growth, yield, nutrient level and contents of soluble sugar and starch. In contrast, the level and initiation point of fertigation did not significantly affect the parameters. Based on our results, the application of properly reduced level of additional fertilizer is possible to maintain the productivity of tomato and alleviate the nutrient accumulation in plastic film house soils.

• Research in Plant Disease
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• v.14 no.2
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• pp.85-89
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• 2008

Clubroot of Chinese cabbage, caused by Plasmodiophora brassicae, is one of the most serious plant diseases in the world. The objectives of this study were to investigate the effect of the irrigation times on the development of club root after planting and to evaluate the effect of clubroot disease on yield of chinese cabbage in pot and field. The clubroot disease gradually increased with increasing irrigation frequency after planting. The growth characters and yield of chinese cabbage by irrigation times varied according to soil moisture and clubroot disease severity. Based on marketable yield and control value, an ideal irrigation point was at the soil matric potential of 0.06 MPa. These results suggest that the suppression on clubroot disease development could be achieved by initially reduced irrigation times after planting. Future studies on irrigation times using fungicide treatment and resistant cultivar under natural field conditions are required to improve the control effect of clubroot.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.316-322
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• 2012

This study was conducted to evaluate the effects of soaking pH and extraction temperature on the physicochemical properties of chicken skin gelatin. In order to extract gelatin from chicken skin, the chicken skin was soaked at various pH ranges (1-13) and was extracted at 75 and $100^{\circ}C$. For the rate of weight increase, the highest value was obtained from two pH ranges (1-2 and 12-13). In addition, the rate of weight increase was affected by soaking time. The alkali treatments had greater crude protein content as well as total extraction yield compared to the acid process (p<0.05), and the increased extraction temperature resulted in a significant (p<0.05) increase of crude protein content and total extraction yield. All treatments showed ${\alpha}1$ and ${\alpha}2$ chains derived from type I collagen on SDS-PAGE. The pH value and color of gelatin gel (6.67%) were affected by soaking pH and extraction temperature. Chicken skin gelatin gel extracted at $75^{\circ}C$ after soaking at a pH of 2 had the highest melting point (p<0.05) and gel strength among all treatments. Although the chicken skin treated with the alkali process had a higher yield, a lower extraction temperature following the acid process would be better for obtaining superior gelatin from chicken skin.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.137-141
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• 1992

To investigate some factors on oleoresin extraction from red pepper, the content of yield, capsanthin and capsaicin in oleoresin extracted under various factors such as solvent, variety of materials, extraction time and temperature, storage condition of dried red pepper and its parts, particle size of raw material powder and the ratios of red pepper powder to extraction solvent were investigated. Ethyl alcohol and ethylene dichloride were effective in extracting capsanthin and capsaicin from red pepper, respectively. Mixed-solvent bore fruitful in increasing of oleoresin yield, but was fruitless in extracting capsanthin and capsaicin in comparison with single-solvent. In three varieties such as Juktoma, Jinsol and Dabok, Jinsol was excellent in oleoresin extraction. Optimum extracting temperature and time was $20^{\circ}C$ and three to five hours, respectively. Oleoresin quality from long-term storage and/or coarse red pepper were low in point of yield, capsanthin and capsaicin. Capsanthin and capsaicin were distributed into pericarp and seed in abundance, respectively. Optimum mixing ratio of red pepper powder to extracting solvent was suitable for one to three(1 : 3) or one to four(1 : 4) in oleoresin extraction.