• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.66-75
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• 1996

This study was carried out to investigate the effects of high temperature and humidity on the ageing of processed leaf tobacco. Four(1993) or six(1994) grades (Both flued-cured and burley) of processed leaf packed in carton box were stored under the natural and artificial conditions. When the Processed leaf was stored in the controlled mom at 40℃ with 75% R.H.(1993) for 40 days, the leaf pH was decreased. The decreasing rate of leaf pH was similar to that of leaf stored under the natural warehouse condition for 15 months. The degree of lightness and yellowness of leaf also decreased, while the decaying or darkening of the leaf was observed. When the processed leaf was stored in the controlled room at 35℃ with 65% R.H.(1994) for 90 days, the pH of flue-cured was decreased 0.22, which was similar to that of the leaf stored under the natural warehouse condition for 15 months, and the lightness, and redness of the leaf were higher than those of the control. As compared with the leaf stored under the natural condition for 2 years, the smoking quality of leaf stored under this condition was similar or somewhat better. The pH of burley tobacco changed little compared to that of flue-cured during storage in this study.

• Journal of the korean Society of Automotive Engineers
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• v.3 no.1
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• pp.38-45
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• 1981

In this paper, the natural frequencies of curved taper leaf springs using on vehicle suspension systems are studied. By applying the Castigliano's definition, Rayleigh's principle and Dunkerley's equation, new formulas defining the natural frequency of such shaped spring are derived. Numerical calculations are in very good agreement with experimental results on actual models. We found that the natural frequencies of curved taper spring are increased by 21-28% compared with the spring having same weight, span and curve but uniform section.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.723-730
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• 1995

Effects of leaf and pod removal on changes in dry weight and protein content of soybean [Glycine max (L.) Merr.] cultivar 'Hwangkeumkong' were measured at the research farm of Korea University in 1992. The upper 40% and lower 60% of leaves and pods were subjected to treatments at the growth stage of beginning pod(R3). Leaf dry weight of lower part was increased by upper leaf-lower pod removal, but seed dry weight of upper part was decreased. The upper leaf-lower pod removal also increased stem dry weight and decreased upper pod dry weight. Protein content was higher in lower leaves than upper leaves. Seed protein contents were decreased both upper leaf-lower pod removal and lower leaf-upper pod removal treatments. The upper leaf-lower pod removal showed the highest leaf and the lowest seed protein quantities among the five treatments. These results indicated that protein sources were moved from lower to upper parts but weak in remobilization from leaves for the long distance translocation during the reproductive growth period of soybean plants.an plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.17-17
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• 2022

Leaves are an important organism for photosynthesis and transpiration. The shape of leaf is crucial factor affecting plant architecture. V-shape leaf rolling is enhancing canopy photosynthesis by increasing the CO₂ penetration and the light capture by reducing the shadow between the leaves. Therefore, moderate leaf rolling is thought to more high grain yield per area than flat leaf. We investigated 278 KRICE_CORE accession's Adaxial Leaf Rolling Index (LRI) in first heading using the following equation. For each accession, genomic DNA was used for sequencing. We sequenced the genomics with ~8 X coverage to detect SNPS. Raw reads were aligned against the rice reference (IRGSP 1.0) for SNP identification and genotype calling. To generate genotype data for GWAS, SNPs were filtered with minor allele frequency 0.05. Finally, 841,134 high-quality SNPs were used for our GWAS. The significant threshold was -log10(P)>7.23. From the results, 2 significance SNP were detected. Considering the LD block of 250kbp, 60 candidate gene were selected including Hypothetical gene and Conserved gene. In this poster, we analyzed candidate gene affecting adaxial Leaf Rolling through single-trait GWAS.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.243-243
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• 2022

Leaves are an important organism for photosynthesis and transpiration. The shape of leaf is crucial factor affecting plant architecture. V-shape leaf rolling is enhancing canopy photosynthesis by increasing the CO₂ penetration and the light capture by reducing the shadow between the leaves. Therefore, moderate leaf rolling is thought to more high grain yield per area than flat leaf. We investigated 278 KRICE CORE accession's Adaxial Leaf Rolling Index (LRI) in first heading using the following equation. For each accession, genomic DNA was used for sequencing. We sequenced the genomics with ~8 X coverage to detect SNPS. Raw reads were aligned against the rice reference (IRGSP 1.0) for SNP identification and genotype calling. To generate genotype data for GWAS, SNPs were filtered with minor allele frequency 0.05. Finally, 841,134 high-quality SNPs were used for our GWAS. The significant threshold was -log10(P) >7.23. From the results, 2 significance SNP were detected. Considering the LD block of 250kbp, 60 candidate gene were selected including Hypothetical gene and Conserved gene. In this poster, we analyzed candidate gene affecting adaxial Leaf Rolling through single-trait GWAS.

• Food Science and Preservation
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• v.21 no.4
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• pp.529-535
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• 2014

To examine the levels of preservatives that occur naturally in food, wild plants used as commercial teas, rice cakes, or spices were studied according to the method of the Korean Food Code and analyzed with a gas chromatograph and HPLC. The levels of the natural preservatives (sodium dehydroacetate, sorbic acid, benzoic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, isopropyl p-hydroxybenzoate, propyl p-hydroxybenzoate, isobutyl p-hydroxybenzoate, butyl p-hydroxybenzoate, and propionic acid) in 21 cases were investigated against 15 kinds of wild plants. Six of 15 kinds of wild plants, such as pine needles, bamboo leaf, kudzu leaf, ramie leaf, mugwort, and nut pine leaf, were confirmed to have had sorbic acid, benzoic acid, and propionic acid. 8.201-21.839 mg/kg of benzoic acid was detected in the bamboo leaf, ramie leaf, pine needles, mugwort, kudzu leaf, and nut pine leaf. The sorbic acid contents of the bamboo leaf and the kudzu leaf were 5.630-24.995 mg/kg, respectively. The propionic acid content of the ramie leaf was 61.324-62.726 mg/kg. Nine kinds of wild plants, such as the Korean berchimia leaf, taro leaf, sasa borealis, lotus leaf, kuansh, chrysanthemum zawadskii, oak tree leaf, Chinese pepper leaf, and persimmon leaf, were not detected at the levels of the natural preservatives.

• Fisheries and Aquatic Sciences
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• v.25 no.8
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• pp.409-416
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• 2022

This study aims to know the effect of water-extracted horseradish Moringa oleifera leaf and KW21 fertilizer combination application on the density of Nannochloropsis sp. It was conducted in the Natural Food Laboratory of State Polytechnique, Tual. The experiment used complete randomized design with 5 treatments and 3 replications: A (25% horseradish leaf extract + 75% KW21), B (50% horseradish leaf extract + 50% KW21), C (75% horseradish leaf extract + 25% KW21), D (positive control of 100% KW21), and E (negative control of 100% horseradish leaf extract). Results showed that Treatment C yielded the best result, both the highest density of Nannochloropsis sp. and suitable harvest time.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.186-197
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• 1995

Site-specific allometric equations relating aboveground tree component biomass and leaf area to tree diameter, basal area, sapwood cross-sectional area and sapwood volume were developed using the destructive harvesting method for Pinus rigida Mill., Larix leptolepis Gordon, and Quercus serrata Thunb. stands in Yangpyeong, Kyonggi Province. There were significantly strong correlations between aboveground tree component biomass or leaf area and diameter at breast height (DBH), basal area, sapwood area and sapwood volume. For a similar diameter tree, the three species had a similar stem wood biomass. However, carbon allocation patterns to stem bark, foliage, branch and total aboveground biomass differed among the three species. Specific leaf area and the ratio of leaf area to sapwood cross-sectional area of the three species were significantly different. Allometric equations seemed To be related to leaf habit or leaf longevity. To elucidate the effect of leaf habit or leaf longevity on allometry and canopy characteristics clearly, more intensive studies are needed.

• Journal of Life Science
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• v.11 no.1
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• pp.14-21
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• 2001

To investigate the changes of carbohydrate metabolism in the senescing leaves of Zea mays during dark-induced senescence, the changes in the contents of reducing sugar, sucrose and starch as well as the activities of sucrose synthase, three isozymes of invertase, and ${\alpha}$-amylase were measured. In the senescing leaves, the content of reducing sugars temporarily increased at 4 d and rapidly decreased thereafter, whereas sucrose contents gradually decreased thereafter, whereas sucrose contents gradually decreased until 3 d of senscence and significantly decreased thereafter. The activities of intracellular invertases such as soluble acid and alkaline formed gradually enhanced until 4 d of leaf senescence and significantly declined thereafter. The extracellular invertase activity showed no significant changes during leaf senescence. The deactivation of sucrose synthase was observed within 3 d of leaf senscence. On the other hand, the starch contents gradually declined during 2 d of leaf senescence, and showed a temporary increase at 3 d, which is similar to the pattern of sucrose synthase activity., These results imply that sucrose in the senescing leaves. The major enzymes which correlated to the breakdown of sucrose during dark-induced senescence were soluble acid and alkaline invertases, not sucrose and ABA accelerated leaf senescence by inducing the accumulation of reducing sugar. These result, therefore, that leaf senescence may be mediated by the temporary quantitative changes of reducing sugar induced by the activation of intracellualr inveertases.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.449-456
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• 2011

Plant leaf cuticle is related to the prevention of moisture loss, transpiration, and diffusion of light reflection. The purpose of this study was to examine the morphological characteristics of ginseng leaves in ginseng plants resistant and susceptible to hightemperature injury (HTI) to be related with the leaf-burning. For the HTI resistant lines Yunpoong, high-temperature injury resistance (HTIR) 1, HTIR 2, and HTIR 3, and the HTI-susceptible line Chunpoong, the cuticle densities were 53.0%, 46.2%, 44.9%, 48.0%, and 17.0%; the adaxial leaf cuticle layers were 141.3, 119.7, 119.7, 159.4, and 85.0 nm in thickness; the abaxial leaf cuticle layers were 153.6, 165.8, 157.9, 199.6, and 119.4 nm in thickness; and the stomtal lengths were 21.7, 32.4, 29.4, 30.9, and $21.8{\mu}m$, respectively. All of these aspects suggest that HTI resistant lines have higher cuticle density, thickicker adaxial and abaxial leaf cuticle layers, and longer of stomta length than the HTI-susceptible line, protecting leaves from moisture loss and excessive transpiration under high temperatures to be resistant against the leaf-burning.