• Polymer(Korea)
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• v.35 no.3
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• pp.203-209
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• 2011

Two smooth and textured surfaced HDPE geomembranes (GMs) were cut into dumbbell shape and notched where depth of the notch produced a ligament thickness of 10% to 90% of the nominal thickness with the specimen at 10% interval. A series of laboratory simulation test for installation damage were carried out at different loading cycles on HDPE GMs in accordance with ISO 10722 test method and the effect of number of loading cycle on installation damage was compared. It was found that yield stress and elongation at yield point decreased gradually as the notch depth was increased. Both installation damaged and notched, GMs were used to understand stress crack behavior and this behavior was observed through NCTL test at $50{\pm}1^{\circ}C$ at different yield stresses immerging in pH 4 and pH 12 buffer solutions. Over 35% tensile load, GMs became vulnerable to stress cracking. Both damaged and notched GMs showed the same trend. Especially, notched GMs showed less strength than installation damaged GMs at every stress cracking test condition.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.128-132
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• 2013

A new pink gerbera (Gerbera hybrida Hort.) cultivar 'Party Time' was developed from a cross between 'Hope' and 'Sunnyeo', followed by seedling and line selections at the Flower Research Institute of Gyeongnam Agricultural Research and Extension Services (GARES) in 2007. Detailed characteristics of the new cultivar were evaluated from 2005 to 2007. 'Party Time' has semi-double type large flowers in a good harmony with pink (RHS, 65-C) ray floret and brown center. It has a good, stable flower shape and strong peduncles, and its vase life was 12.7 days. The average flower yield of 'Party Time' was about 47.3 stems per plant a year in greenhouse yield trails carried out 2005 to 2007. 'Party Time' (Grant No. 2691) was registered to the Korea Seed and Variety Service (KSVS) for commercialization in 2009.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.851-856
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• 2005

Although valuable microbes have been isolated from the soil for the various productions of useful components, the microbes which can be cultivated in the laboratory are only $0.1-1\%$ of all microbes. To solve this problem, the study has recently been tried for making the valuable components from the environment by directly separating unculturable micrbial DNA in the soil. But it is known that humic acid originated from the soil interrupts various restriction enzymes and molecular biological process. Thus, in order to prevent these problems, this study modified the method separated soil DNA with phenol, CTAB and PEG. In order to compare the degree of purity for each DNA and the molecular biological application process, $A_{260}/A_{280}$ ratio, restriction enzymes, and PCR were performed. In case of DNA by the modified method, total yield of DNA was lower but $A_{260}/A_{280}$ ratio was higher than the previously reported methods. It was confirmed that the degree of purity is improved by the modified method. But it was not cut off by all kinds of tested restriction enzymes because of the operation of a very small amount of interrupting substances. When PCR was operated with each diluted DNA in different concentrations and GAPDH primer, the DNA by the modified method could be processed for PCR in the concentration of 100 times higher than by the previously reported separation method. Therefore, this experiment can find out the possibility of utilization for the unknown substances by effectively removing the harmful materials including humic acid and help establishing metagenomic DNA library from the soil DNA having the high degree of purity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.2
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• pp.93-100
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• 1995

This experiment was carried out to investigate how to effect the application of nitrogen, phosphate and potassium on the vegetation and dry matter yield in the mixed sward of orchardgrass and crabgrass (Digitaria sanguinalis [L.] Scop.). The experimental sward wa5 consisted of eight plots of non-application, P, K, PK, N. NK, NP and NPK. These plots were sown with seeds mixture of orchardgrass 17.5 kglha and crabgrass 17.5 kg/ ha on 22 April 1975 in the forage experimental field of Kangwon National University, Chunchon, Korea, and were cut four times from 6 July to 18 November 1975. The results obtained were summarized as follows: 1. In orchardgrass density measured after summering, the plot of nitrogen applied without phosphate marked only 3 1.0% of the plot of nitrogen applied with phosphate while in crabgrass density measured at that time the plot of nitrogen applied without phosphate marked as high as 112.5% of the plot of nitrogen applied with phosphate. 2. Application of phosphate and potassium improved wintering record of orchardgrass. In orchardgrass density measured after wintering, the plot of nitrogen applied without phosphate marked only 9.7% of the plot of nitrogen applied with phosphate, and the plot of NP applied without K marked 63.6% of the plot of NP applied with K. 3. In surface coverage of orchardgrass, in midsummer any plot applied with nitrogen regardless of accompanying with or not with phosphate wa5 0%, but in autumn the plot of nitrogen applied with phosphate was 56-58% and the plot of nitrogen applied without phosphate was 5%. While after wintering the plot of nitrogen applied with phosphate was 28-37% though the plot of nitrogen applied without phosphate was only 0.3-0.6%; the application of phosphate improved summering and wintering record of orchardgrass. 4. Application of phosphate demonstrated remarkable effect on increasing dry matter yield in orchardgrass. In year total yield of orchardgrass, the plot of nitrogen applied without phosphate marked as low as 11.3% of the plot of nitrogen applied with phosphate, but in crabgrass the plot of nitrogen applied without phosphate was almost equal to the plot of nitrogen applied with phosphate showing 97.5% of this plot. 5. Application of potassium was not effective on increasing dry matter yield of orchardgrass but its application was effective on increasing dry matter yield of crabgrass. In dry matter yield of orchardgrass significant difference was not found between NP plot and NPK plot, but in dry matter yield of crabgrass NPK plot recorded significantly higher yield compared with NP plot (p<0.05). 6. In botanical composition of the plot of nitrogen applied with phosphate, crabgrass recorded 46.5-50.5% in early summer (July) but in midsummer (August) it dominated the plot recording 85.6-91.2%. 7. In botanical composition based on the year total yield, in the plot of nitrogen applied with phosphate orchardgrass marked 21.7-26.2% and crabgrass recorded 73.8-78.370, but in the plot of nitrogen applied without phosphate orchardgrass marked only 3.5% being overwhelmingly dominated by crabgrass which recorded 96.5%. 8. Application of nitrogen not accompanied with phosphate strengthened competitive power of the crabgrass unilaterally, making orchardgrass be oppressed fatally by the crabgrass.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.169-175
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• 1985

This experiment was carried out during 1983-1984 to determine an effective method for the introduction of pasture species on nonarable hill country without cultivation. In this experiment, 1.8 and 2.8kg a.i. $ha^{-1}$ rates of glyphosate and a 0.7kg a.i.$ha^{-1}$ rate of paraquat were applied, and also 30, 45 and 60 days intervals between spraying and sowing were used. Establishment of orchardgrass (Dactylis glomerata) was not affected by the application of herbicides, but that of ladino clover (Trifolium repens) was significantly affected by glyphosate and paraquat. It was found that glyphosate and paraquat have no apparent soil residual activity or pre-emergence effect when sprayed 30 to 60 days before sowing. Dry matter yield of pasture species on the herbicide treatments was significantly higher than that on the unsprayed treatments. The highest yield was obtained from the 1.8kg a.i.$ha^{-1}$ rate of glyphosate 45 days before sowing. Botanical analysis at the final cut showed that the shrubs and native grass of original site were reduced to 5% by glyphosate application, but those on the unsprayed control were still 51%. Crude protein content and in vitro dry matter digestibility of herbage on the herbicide treatments were higher than those on the unsprayed treatments. Results indicated that glyphosate was more effective to control resident shrubs and grass than paraquat, and good establishment and higher yield of surface-sown pasture species can be obtained by spraying 1.8 to 2.8kg a.i.$ha^{-1}$ of glyphosate, 30 to 45 days before sowing.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.247-250
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• 1998

This study was carried out to investigate the effects of changes of ionic strength according to growth stage on growth and flowering of Dendranthema grandiflorum (Ramat.) Kitamura 'Seiun' grown hydroponically in perlite. The stage I, II, and III covered early vegetative growth (27-40 days after planting), latter vegetative growth (41-54 days), and reproductive growth (55-80 days), respectively. The 2 strength (1S and 2S) of nutrient solution were treated in stage I, whereas 3 strengths (1S, 1-2S, and 2S) were treated in stage II. Then, total 9 treatments in stage III were designated by 3 treatments (tap water, 1S, and 2S) for each 3 strengths in stage II. Each nutrient solution was applied 8 times per day. At vegetative growth stage (54 days after planting), stem length was highest when irrigated 8 times a day with 1S nutrient solution. Both photosynthesis and transpiration rate were higher in 1S than those in other treatments (1-2S, 2S), whereas leaf chlorophyll content was highest in 2S treatment. Ion content of plant treated with 2S was higher than other treatments. Growth (plant height, leaf area, stem length), fresh weight, and dry weight of each plant organ after flower bud formation were better in tap water treatment (1-1-0) than other 1S treatments (1-1-1, 1-1-2). Regarding the number of days to flowering, tap water treatment was the most effective. Thus, after flower bud formation supplying tap water or lower concentration of nutrient solution than those used during the vegetative growth stage was economical in saving chemical fertilizers, shortening the number of days to flowering, reducing salt accumulation in media, saving efforts of leaching, and reducing ground water contamination.

• Journal of Nutrition and Health
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• v.38 no.7
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• pp.533-543
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• 2005

The purpose of this study was to determine the iron status of preschool children in Ulsan, Korea. The study was con-ducted using 95 children aged 3 to 6 years by investigating the anthropometric indices and assessing the dietary intakes and biochemical analysis. A questionnaire for dietary intakes using 24-hr recall method were carried out by the mothers of the 95 subjects. And also a study was conducted to assess hematological and biochemical status of iron and prevalence of iron deficiency. The average height and weight were 105.4 $\pm$ 7.0 cm, 18.7 $\pm$ 3.2 kg in boys, 103.8 $\pm$ 6.7 cm, 17.6 $\pm$ 2.7 kg in girls. These were lower than the body growth standard values of Korean pediatrics. There was not a significant difference in both between boys and girls. For the daily nutrient intake, energy was 1201.5 $\pm$ 280.9 kcal (79.3$\%$RDA), protein was 63.8 $\pm$ 28.2 g (219.4$\%$RDA), iron was 11.9 $\pm$ 4.5 mg (133.2$\%$RDA). The iron nutritional status by hematological assay found that Hct was 34.7 $\pm$ 2.0 ($\%$), Hb was 12.0 $\pm$ 0.8 g/dl, RBC was 4.3 $\pm$ 0.3 ($10^6/{\mu}l$), MCV was 80.5 $\pm$ 3.0 fL, MCH was 27.8 $\pm$ 1.1 pg and MCHC was 34.6 $\pm$ 0.6 g/dl. The biochemical measurement of serum iron was 75.6 $\pm$ 30.3 ${\mu}g$/dl, TIBC was 320.3 $\pm$ 34.1 ${\mu}g$/dl, serum ferritin was 30.0 $\pm$ 14.8 ${\mu}g$/dl, Zinc-Protophor-phyrin (ZPP) was 32.7 $\pm$ 8.0 ${\mu}g$/dl, and ZPP/Heme was 71.1 $\pm$ 19.5 ($\mu$mole/mol heme). The prevalence with Hct, Hb, TS and serum ferritin less than cut-off value was $8.4\%,\;9.5\%,\;12.6\%$ and $4.4\%$ respectively. But the prevalence of iron deficiency estimated with ZPP and ZPP/Heme criteria were $25.3\%$ and $27.4\%$, and were higher than in case of any other indices. The prevalence of iron deficiency anemia ((low Hb (< 11.0 g/dl) and low serum ferritin (< 10 ${\mu}g$/L) or low TS (3-4 yews: < $12\%$, 5-6 years: < $14\%$)) was found in only one 3 year old girl. The prevalence of iron deficiency except Hct and Hb was the highest in 3 year group, but the prevalence by Hct and Hb was the highest in 5 year group. Iron deficiency and iron deficiency anemia do not seem to be a major public health problem in preschool children in Ulsan.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.692-698
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• 2001

This study has been carried out to estimate aboveground biomass and net primary production(NPP) in an average 41-years-old Quercus variabilis stand of Gongju area, 45-years-old Quercus variabilis stand of Pohang area, and 54-years-old Quercus variabilis stand of Yangyang area. Ten sample trees were cut in each forest and soil samples were collected in July to August, 2000. Estimation for aboveground biomass and net primary production were made by the equation model $Wt=aD^b$ where Wt is oven dry weight in kg and D is DBH in cm. Total aboveground biomass was 91.31ton/ha in Gongju area, 207.6ton/ha in Pohang area, and 71.39ton/ha in Yangyang area. The aboveground biomass 207.6ton/ha in Pohang area is the highest biomass production among the amount of biomass in Quercus variabils stands reported in Korea. The proportion of each tree component to total aboveground biomass was high in order of bolewood, bolebark, branches and leaves in the three forests. Aboveground total net primary production was estimated at 7.8ton/ha in Gongju area, 11.5ton/ha in Pohang area, and 6.40ton/ha in Yangyang area. There were at least 2 times higher total aboveground biomass in Pohang area than in the Gongju and Yangyang areas because of climate difference among the study areas.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.107-111
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• 2008

This experiment was carried out to examine the effect of silicate on the rooting of cuttings and growth of cut chrysanthemum. In the first experiment, cuttings of chrysanthemum 'Pink Pixie Time' were grown in a 3 L medium which was supplemented with silicate at 0, 30, 60, or 90 g for examination of its effect on rooting of cuttings. In the second experiment, chrysanthemum 'Backwang' was grown in medium supplemented with silicate at 0, 60, 90, 120 or 240 g per 20 L medium. In the first experiment, the promotional effect of silicate increased with increasing silicate concentration in the medium, resulting in increased length of shoot and root. However, root dry and fresh weights were not affected by silicate concentration in the medium. In the second experiment, number of branches, plant height, number of nodes, and stem diameter in the silicate-supplemented treatments were greater than those in the control. However, dry matter was not affected significantly by silicate concentration in the medium. Fresh weights of the leaf, stem and root in the silicate-supplemented treatments were greater than those in the control.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.201-204
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• 2009

A new orange mini gerbera (Gerbera hybrida Hort.) 'Yetty' was developed from a cross 'Haiti' and 'Nova Zembra' followed by seedling and line selections at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) from 2001 to 2006. Three times evaluations were conducted from 2004 for the detailed characteristics of the new cultivar, 'Yetty' has single type mini flower in good harmony with orange (RHS 25-A) ray floret and browen center. It has good stable flower shape and strong peduncle, and its vase life was 14.8 days. The average yield of 'Yerty' was 98.5 flowers per plant a year in greenhouse yield trials carried out from 2004 to 2006. This cultivar registered for commercialization in 2007. 'Yerty' would be cultured under greenhouse condition in Korea.