• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.257-264
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• 1975

This research was attempted as one of a study for investigating optimum contents of fly ash and briquette ash when they were used as admixtures. In mix designs of mortar, fly ash and briquette ash to cement, each of them, was mixed with 0, 5, 10, 15, 20, 25, 30 percent by weight of cement. They were tested for compressive strength, tension strength and bending strength, and these results were summarized as follows; 1. The compressive strength of mortar to add fly ash showed the maximum value at 25 percent. tension strength, 20 percent, bending strength, 15 percent. 2. In case of using briquette ash, compressive strength showed maximum strength at 15 percent. tension strength, 20 percent, bending strength, 20 percent. 3. To add fly ash showed in general more additive effect than to add briquette ash. 4. It was not only to excess standard strength but may be to develop as admixture when briquette ash was used around 20 percent.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.476-482
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• 2001

This experiment was conducted to evaluate the effect of slow-release fertilizer application on quality elevation of onion (Allium cepa L.) in southwestern sea. The slow-release fertilizers used were NIAST (National Institute of Agricultural Science and Technology) I, II, CDU (Crotonylidene Diurea), UF (Urea-Formaldehydes), and IBDU (Isobutylidene Diurea) 30, 50. Growth of the onion plant treated with slow-release fertilizer showed better than the control. However, a rate of infected plant to downy mildew was low as compared with control. Chlorophyll and total nitrogen contents were high in control, whereas firmness, soluble solid content, number and thickness of scaly leaves were high in slow-release fertilizer plot. In early maturing onion, total marketable bulb yield was higher in slow-release fertilizer plot than all other fertilizer treatments. Total marketable bulb yield in late maturing onion treated with slow-release fertilizer was slightly decreased. Decaying loss and the rate of sprouting during storage period decreased in slow-release fertilizer application. In summary, application of slow-release fertilizer increased marketable yield, storability after harvest and also reduced labor needs for top dressing.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.207-213
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• 1976

In order to obtain the prediction of the maximum dry density and the optimum moisture content of soil without soil moisture test, compaction test results from 157 different places either under construction or already completed were analyzed. The analyzed results were as follow The relationship between the maximum dry density and the optimum moisture content of the soil showing a correlation coefficient of 0.96 indicated that there was a high correlation between them. From the above relationship we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.4193+0.00937W_{opt.}}$ Equation between the optimum moisture content and the maximum wet density of the soil was $W_{opt.}={\frac{0.4193{\gamma}_{tmax.}}{0.937_{\gamma}_{tmax.}-0.01}$, and the values of the optimum moisture content being predicted with the maximum wet density of the soil showed a little difference between those and tested values. The values of the maximum dry density being predicted with the moisture content estimated by the maximum wet density of the soil were within the range of ${\pm}5%$ of its tested values. The relationship between the dry density and the void ratio showed a high correlation between them (${\gamma}=0.9706$). From the above relationship, we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.3938+0.3426e}}$.

• Applied Biological Chemistry
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• v.11
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• pp.55-61
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• 1969

This K-17 strain was not absolutely requiring xylose as an inducer for enzyme formations. The most activity of this enzyme was lost when treated at $75^{\circ}C$. for 30 hours but was not influenced at $70^{\circ}C$. for 70 hours of treatment. The activity of this enzyme was increased by the addition of magnesium ions or cobalt ions in the reaction system. In the studies, we found that the magnesium ions simply activate the enzyme reaction and the cobalt ions do not but protect the enzyme from heat inactvation. And it was also found the phosphate buffer solution was very suitable as glucose dissolving solvent on the enzyme reaction. The mixed carbon source medium containing glucose, fructose, sorbitol, xylose and sucrose was more favorable for enzyme production then a sole carbon source containing medium on the shaking culture method.

• Journal of Korea Foresty Energy
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• v.1 no.2
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• pp.34-42
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• 1981

• Journal of the Korean Wood Science and Technology
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• v.29 no.2
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• pp.91-99
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• 2001

In this study the possibility of classifying wood surface defects by image processing technique was investigated. An algorithm for the classification of wood surface defects, such as knot, check, and bark, on three Korean domestic species, Pinus densiflora, Quercus acutissima, and Carpinus laxiflora was also developed. Filtering was executed to separate dummies from the labels including real defect. Error rates in classifying knots on Pinus densiflora and Quercus acutissima were lower than 1% and error rates. In classifying check and bark in Quercus acutissima and Carpinus laxiflora could be lowered to below 13%.

• Korean journal of applied entomology
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• v.17 no.3 s.36
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• pp.139-142
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• 1978

Activities of several hydrolytic enzymes in the rusted pear loaves were estimated. Tested enzymes were cellulase (Cx), invertase $\beta-amylase$, pectinase (pectinmethylesterase and polygalacturonase), and phosphatase. Enzyme activities represented by pH value-enzyme activitycurve. Activities of Cx. invertase. and $\beta-amylase$ were higher in the healthy part than those in the near-lesion and lesion parts. and showed the maximal activities around pH 7.0. On the other hand, activities of pectinase and phosphatase were higher in the lesion and near-lesion parts than in the healthy part. Pectinmethylesterase activities in the healthy and diseased parts were different with different curve-pattern as the pH of treating solution changed.

• Journal of Life Science
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• v.20 no.5
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• pp.750-759
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• 2010

The bioactive materials (phenolic compounds, flavonoids, minerals, decursin and decursinol angelate) and biological activities (DPPH [$\alpha,\alpha$'-diphenyl-$\beta$-picrylhydrazyl] free radical scavenging capability, reducing power, and tyrosinase activity) in the extracts of leaf, stem mixture (AGLS), and root (AGR) from Angelica gigas Nakai were examined by using water, hot water and ethanol solvent. The highest extract yield (21.89%) was found in the water extract of AGR. The highest concentrations of phenolic compounds and flavonoids in the ethanol extracts of AGLS and AGR were 14.99% and 14.79%. Major minerals of AGLS and AGR were K, Mg, Fe, Na and Ca. Decursin and decursinol angelate were the major ingredients of Angelica gigas, detected at 18.71 and 18.89 min of retention time by HPLC analysis, respectively. The highest concentrations of decursin and decursinol angelate in the Angelica gigas ethanol extract were found in root ($41.7\;{\mu}g/g$) and leaf ($34.04\;{\mu}g/g$). The highest free radical scavenging activity was found in the hot water extracts of AGLS and AGR, and its activity was stronger in all extracts of AGLS than AGR. The highest reducing power was found in the ethanol extracts of AGLS and AGR and this was dependent on the sample concentration. The hot water extracts of AGLS and AGR revealed the highest inhibition activity on tyrosinase. Overall, these results may provide the basic data needed to understand the biological activities of bioactive materials derived from Angelica gigas.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.197-202
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• 1984

Two soybean cultivars Hanan and Kwanggyo were used to monitor SMV spread in the field. The Haman producing mosaic symptoms by infection with SMV strain G7 was planted in $2.2m^2$ at the coater of $320.7m^2$ field and Kwanggyo producing necrosis by infection with SMV-G7 was planted around the Haman one day after inoculation of Heman with SMV-G7. The most severe incidence of the necrotic disease in soybean cultivar Kwanggyo occurred on 43 days after planting(July 13) whereas aphid population reached peak around 22 days after planting(June 22). Total incidence of the necrotic disease was $20.4\%$, in the whole field and $56\%$, in eight $mall plots around the spreader of SMV. The spread of S MV outward from the spreader source was greater downwind than it was upwind. Spread also showed a signigicant gradieut pattern leeward from the infection focus.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.177-182
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• 1971

A new method for the measure of iron pools using 0.02M EDTA and $Na_2S_2O_4$ was tested on Akagare diseased and healthy rice leaf tissue 1) The proposed method could fraction iron into four fractions; ferrous iron($Fe^{++}$), ferric iron($Fe^{+++}$) precipitated iron(PFe) and bound iron(BFe) well indicating the physiological status of tissue. 2) The pattern of iron pools appears to be $Fe^{+++}>PFe>BFe>Fe^{++}$ in most physiologically favorable status of iron, $PFe>Fe^{+++}>BFe>Fe^{++}$ in favorable status, $BFe>Fe^{+++}>PFe>Fe^{++}$ in unfavorable status and $BFe>PFe>Fe^{+++}>Fe^{++}$ in toxic status. 3) The percentage of each fraction to total iron was less than 10 for $Fe^{++}$, 20 to 40 for $Fe^{+++}$ and PFe and 20 to 50 for BFe. 4) Ferrous iron was always higher in upper half leaf, the appearance of which is less healthier than lower half indicating that there is more active metabolic system in which ferrous iron is involved.