• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.36-44
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• 2007

The purpose of this study was to investigate thermal stability, reactivity, and bonding strength of existing epoxy resin mixed with the epoxidized soybean oil (ESBO) in order to use soybean oil economically. In the dry shear test, the marked strengths showed $30.5kgf/cm^2$ at the ratio of ESBO to epoxy resin 9 : 1 and $6.2kgf/cm^2$ at the ratio 8 : 2. The bonding strengths of the others, except mixing ratios 2 : 8 and 1 : 9, exceeded the requirement of Korean plywood standard of $7.0kgf/cm^2$. In the wet shear test, the result was $5.8kgf/cm^2$ at the ratio 9 : 1. There were no thickness swelling and moisture absorption in the water resistance of the film. The value of activation energy, Tg (${\Delta}E$), by DSC analysis showed between $110^{\circ}C$ and $120^{\circ}C$ through all ratios. Epoxy in the epoxy resin fully reacted with the hardener (TETA), but it is difficult to decide that epoxys in the ESBO were reacted directly with the hardener from FT-IR analysis. As the mixing ratio of ESBO increased, the thermal stabilities dropped from TGA analysis. From the comprehensive view on the results of above experiments, it could be confirmed through experiments that the ESBO in the mixed adhesive of epoxy resin/ESBO played a role as an extending agent level of epoxy adhesive, and we were able to know that in order to utilize ESBO as an adhesive, a study should be performed on the condition of hardening, inducible of the hardening reaction.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.269-275
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• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.4
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• pp.291-300
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• 2010

This study was carried out in the Chungnam National University grassland experimental field from October, 2007 to December, 2009 in order to find out the growth characteristics of the wildflowers, the seasonal anthesis distribution of the wildflowers and the botanical composition of the wildflowers which were altogether composed of 50% sheep fescue and 50% wildflowers. The experimental species contained 34 species in total consist of sheep fescue (fundamental turfgrass), 4 native wildflowers, and 29 introduced wildflowers belonged. At the time of the anthesis of the wildflowers, the average length was 30.0 cm one year later and 35.6 cm two years later. They bloomed out into ten colors, but into simplified colors during August, September, and October. The peak of the blooming was May and June and blooming pattern leant from August to October. Especially, at the age of two (2009) the color, seasonal distribution, and consistency emerged as problems owing to the reduction of annual wildflowers after winterization. The annual botanical composition of wildflowers, sheep fescue, and weed came to 28%, 55%, and 17% each one year later (2008) and 24%, 60%, and 17% each two years later (2009). Based on this result, cultivating wildflower grassland (sheep fescue 50% + wildflowers 50%) is the proper method for making up such flatlands as parks and riversides in a short period (one year) for the purpose of commanding a fine view.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.227-236
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• 2010

This study was carried out in order to find out the growth characteristics, the seasonal anthesis distribution and the botanical composition of the wildflower pastures which were altogether composed of 90% sheep fescue and 10% wildflowers in the Chungnam National University experimental field from October, 2007 to December, 2009. The experimental species contained 34 species in total consisting of sheep fescue (fundamental turfgrass), 4 native wildflowers, and 29 induced wildflowers belonged. At the time of the anthesis of the wildflowers, the average length was 28.7 cm one year later and 36.7 cm two years later. They bloomed out into from six to nine colors, but into one or three colors during August, September, and October. The blooming season leant toward May and June, and from August, there was lots of difficulty in the wildflower blooming and the maintenance of their consistency. Especially, at the age of two (2009) the color, seasonal distribution, and consistency emerged as problems owing to the reduction of annual wildflowers after winterization. The annual botanical composition of wildflowers, sheep fescue, and weeds came to 22%, 68%, and 10% each one year later (2008) and 19%, 72%, and 9% each two years later (2009). Based on this result, cultivating wildflower in grassland (90% sheep fescue and 10% wildflowers) is the proper method not only for maintaining green space, to prevent soil erosion by sheep fescue, but also for commanding a fine view of wildflowers.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.285-294
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• 2011

This study was carried out in the Chungnam National University grassland experimental field from October, 2007 to December, 2009 in order to find out the growth characteristics of the wildflowers, the seasonal anthesis distribution of the wildflowers, and the botanical composition of the wildflowers which were altogether composed of 70% sheep fescue and 30% wildflowers. The experimental species contained 34 species in total to which sheep fescue (fundamental turfgrass), 4 native wildflowers, and 29 introduced wildflowers belonged. At the time of the anthesis of the wildflowers, the average length was 29.9 cm one year later and 38.4 cm two years later. They bloomed out into nine colors, but into one or three colors during August, September, and October. The blooming season leant toward May and June and from August there was lots of difficulty in the wildflower blooming and the maintenance of their consistency. Especially, at the age of two (2009) the color, seasonal distribution, and consistency emerged as problems owing to the reduction of annual wildflowers after winterization. The annual ration of wildflowers, sheep fescue, and weeds came to 25%, 61%, and 14% each one year later (2008) and 22%, 65%, and 13% each two years later (2009). Based on this result, cultivating wildflower grassland in the ratio of 70% (sheep fescue) to 30% (wildflowers) is the proper method not only for maintaining green space by sheep fescue, but also for commanding a fine view of wild flowers.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.116-123
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• 1991

Two solution to soil ratios, 2 : 1 and 5 : 1 were tested to determine the appropriate ratio in the sorption measurement off. sulfoxide for Wahiawa soil samples, 0-20 cm, 40-60 cm and 100-120 cm. and Salinas soil samples, 0-15cm and 115-130cm. One ${\mu}$ mol/L f.sulfoxide was used as an initial equilibration concentration. Sorption of f.sulfoxide at 5 : 1 ratio showed appropriate mixing, while sorption at 2 : 1 ratio indicated insufficient mixing during the various batch equilibration times (4, 12, 24 and 48 hours). For most samples the degree of sorption was about 20-50%, which falls in the desired range (20-80%) at the 5 : 1 ratio. An exception was with the low-sorptive Wahiawa subsoil in which the ranges were below 20%. Thus the 5 : 1 ratio can be used for f.sulfoxide sorption measurement. Four equilibration times (4, 12, 24 and 48 hours) and four concentrations(0.1, 1.0, 5.0 and $10{\mu}mol/L$) were used to determine the appropriate equilibration time for Wahiawa and Salinas soils. Sorption increased over all equilibration times, indicating no complete equilibrium within 48 hours. Apparent equilibrium was reached in 4 hours, and sorption increased slowly until 24 hours and faster thereafter, except for the Wahiawa soil, 100-120 cm. The recommended equilibration time is 24 hours, since it may eliminate the insufficient sorption and yet avoid undesirable transformation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.436-441
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• 1992

This study was carried out to discuss the influences of the different fertilizer levels and plant densities on the flowering and balling in cotton in Mokpo Branch Station, Crop Experiment Station in 1991. The cotton flowered 67% before Aug. 25 which is the limit date of picked-cotton harvest, and the ratio of flowering for stalk-cut cotton was 30%. The 1.5 times fertilizer levels and the 70cm row density had more flower buds, flowers and bolls per m$^2$ than any other treatment plot. The crop growing was bad in dense planting due to the nutrient deficiency. The flowering ratio to flower bud was about 70%, and the balling ratio to flower numbers was about 48%. The bolling ratio was lower in the case of more flower number. The shedding ratio of flower buds was about 30% in average and showed increasing tendency by dense planting. It was observed that the higher ratio of bud shedding tended to accompany with shedding the lower ratio of boll shedding.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.340-346
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• 2003

This study was carried out to improve cultivation techniques by low cost and labour saving in ginseng (Panax ginseng C. A. Meyer) seedling production, by elucidating proper ratio virgin soil and organic fertilizer, suitable height of front piller. The obtained results are as follows ; The optimal ratio of white decomposition of virgin soil and organic fertilizer was 10:1 for good yield of standard seedling, The fittest height of front piller was 150 cm because of both good seedling growth and yield. The cost for production of seedling of ginseng could be reduced by both optimal ratio of virgin soil, organic fertilizer and selection of front piller height.

• Journal of the Korean Solar Energy Society
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• v.21 no.4
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• pp.29-35
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• 2001

The chemical heat storage as the one way of utilization for high temperature solar energy was considered. The stram reforming reaction of methane was chosen for endothermic reaction. The reactor was made of stainless steel tube and it's dimension was 0.635 cm I.D. and 30 cm long, coiled tube because of the geometry requirement of solar receiver The effects of space velocity and reactants mole ratio on the methane conversion and CO selectivity were examined. From the experimental results, the optimum steam/methane mole ratio was determined.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.165-181
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• 2002

The purpose of this survey was to assess the nutritional status of preschool children a county of Jeju Island. This study used health examinations results for preschool aged children, performed by the public health center of Pukjeju-gun in Jeju-do for over three years from 1999 to 2001, of children in kindergartens and children homes. The target children totaled 5,990 from the ages three to six. For a control group, 316 children from the nearby Jeju-city areas were included as well. The items of this research included height, weight, and hemoglobin values. 1. The average height of boys from ages three to six were 96.35cm, 102.14cm, 109.94cm, 111.00cm respectively, and girls were 94.96cm, 100.93cm, 108.33cm, 110.54cm respectively. The average weights of boys from ages three to six were 15.42kg, 16.93kg, 19.65kg, 19.67kg respectively, and the weight of girls were 14.90kg, 16.45kg, 18.88kg, 19.50kg respectively. 2. The percentages of children who did not reach 90% of the Korean standard height were 4.3% in boys 4.1% in girls. The percentages of children with less than 80% of the Korean standard weight were 7.6% in boys and 6.8% girls. The percentages of children over 120% of Korean standard weight were 10.4% in boys and 11.4% in girls. 3. As for the obesity level, the percentage of boys under-weighed(under 10% for standard weight for height) were 11.6% and girls, 9.5%, and the percentages of boys and girls with obesity($\geq$20%) were 3.6% and 4.4% respectively. 4. The mean hemoglobin value of boys were 11.83g/$d\ell$ and girls, 11.83g/$d\ell$. These were lower than the value of average normal Korean children (12.5g/$d\ell$). The mena hemoglobin values of the children in Pukjeju-gun were considerably lower than that of the children living in Jeju-city(12.3g/$d\ell$) as well. Anemia of Children of Pukjeju-gun were estimated at 38.1%(male) and 37.2%(female), by using Hemoglobin level(<11.5g/$d\ell$ 5. The rates of children included within the normal range of obesity level in Jeju-city and Pukjeju- gun were boys 80.2%, 71.6% in boys, and 77.4%, 72.4% in girls. The percentage of children living in PukJeju-gun included within the normal range were considerably low. 6. There were no changes in the Body Mass Index (BMI) during the three years from 1999 to 2001, but the percentage of children with anemia significantly increased. Health care for preschool aged children, especially in the rural areas, is very important. Centering on public health centers, it is necessary to systematically promote health care in the rural areas.