• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.409-415
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• 1985

This study has been carried out in order to investigate the bacterial quality of fish meat paste products and the characteristics of isolated thermodurics from the products. Twenty samples of crab-flavored fish stick (Kematsal), 23 samples of plate fish meat paste (Panomuk, Kamaboko), 5 samples of fried fish meat paste (Tigimomuk), 2 samples of roasted fish meat paste (Puduromuk, Chikuwa), 20 samples of fish sausage were collected from processing plants and supermarkets in Pusan, Korea during the period from May to October in 1984. The results obtained are as follows. Amont the samples collected from supermarkets, roasted fish meat paste and fried fish meat paste marked hish counts in coliforms and fungi while very low in the samples of crab-flavored fish stick and plate fish meat paste. Salmonella was not detected in all the samples examined and Staphylococcus aureus was detected only in fried fish meat paste, Thermoduric bacteria were detected less than 10$^2$/g in the samples of crab-flavored fish stick and plate fish meat paste, which might come from subsidiary materials such as starch and seasonings. Among the isolated bacteria, distribution of the proteolytics were more than 87％ and the lipolytics were less than 20％. Gram positive bacteria was more than 70％ in crab-flavored fish stick and plate fish meat paste, 47.3％ in fried fish meat paste. And rod in shape was almost more than 90％ in all the samples. The most heat resistant bacterium isolated from the samples was identified as a Bacillus licheniformis(named B. licheniformis CR-11). The strain showed strong proteolytic activity and also grew well at above 2$0^{\circ}C$. The growth rate and generation time of CR-11 strain were 0.31 hr$^{-1}$ , 2.24 hr at 2$0^{\circ}C$, 0.64 hr$^{-1}$ , 1.09 hr at 3$0^{\circ}C$ and 0.78 hr$^{-1}$ , 0.89 hr at 35$^{\circ}C$. Heat resistance value of the spores of CR-11 strain suspended in phosphate buffer solution was D$_{85}$ $^{\circ}C$=41.9 min, D$_{90}$ $^{\circ}C$=27.9 min, D$_{95}$ $^{\circ}C$=10.2 min, D$_{100}$ $^{\circ}C$=4.3 min (Z=13.8$^{\circ}C$)

• Tunnel and Underground Space
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• v.30 no.3
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• pp.256-269
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• 2020

The objective of this study is to evaluate the stress thresholds in crack development and the corrected fracture toughness of KURT granite under dry and saturated conditions. The stress thresholds were identified by calculation of inelastic volumetric strain from an uniaxial compression test. The corrected fracture toughness was estimated by using the Level II method (Chevron Bend specimen), suggested by ISRM (1988), in which non-linear behaviors of rock was taken into account. Average crack initiation stress(σ_ci) and crack damage stress(σ_cd) under a dry condition were 91.1 MPa and 128.7 MPa. While, average crack initiation stress(σ_ci) and crack damage stress(σ_cd) under a saturated condition were 58.2 MPa and 68.2 MPa. The crack initiation stress and crack damage stress of saturated ones decreased 36% and 47% respectively compared to those of dry specimens. A decrease in crack damage stress is relatively larger than that of crack initiation stress under a saturated condition. This indicates that the unstable crack growth can be more easily generated because of the saturation effect of water compared to the dry condition. The average corrected fracture toughness of KURT granite was 0.811 MPa·m^0.5. While, the fracture toughness of saturated KURT granite(K_CB) was 0.620 MPa·m^0.5. The corrected fracture toughness of rock in saturated condition decreases by 23.5% compared to that in dry condition. It is found that the resistance to crack propagation decreases under the saturated geological condition.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.3
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• pp.145-160
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• 1979

The effects of organic material application on soil physical properties were reviewed in relation to soil productivity. The organic matter contents and soil physical properties of the cultivated land in Korea were summarized and the effects of organic matter were compared in terms of land uses and soil types. Soil physical properties related to crop yield potential, such as soil aggregation, permeability, water holding capacity, erodibility, and compactibility, were used in evaluating the effects of organic materials as a soil physical amendment. The benefical effects of organic matter addition on soil physical conditions include (1) better aeration and increased infiltration in silty and clayey soils, (2) increased water holding capacity and moisture availability in sandy soils, (3) decreased soil erodibility, and (4) increased resistance to compaction. It is, therefore, concluded that continuous application of organic materials could greatly improve the various soil physical properties and favor the growth and yield of crops. A high rate of organic matter addition could contribute to reducing not only the soil erosion on sloping land, but also the possible detrimental effect of farm mechanization. In general, the effects of organic matter on soil physical improvement were estimated to be much higher in upland than in paddy. Organic matter would have a more pronounced effect on low productive lands such as heavy clayey or sandy soils and newly reclaimed soil. The optimum level of soil organic matter content was estimated to be about 3.0 to 3.5% for the best soil physical condition. Since the organic matter contents of the cultivated lands in Korea are much lower than optimum level, it would be desiable to use more organic materials to soil for the increase of soil productivity, continuation of stabilized high productivity and soil erosion control.

• Journal of fish pathology
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• v.18 no.1
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• pp.19-28
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• 2005

Scuticociliatosis has badly settled one of most damaging diseases during the seedling production process of olive flounder. Paralichthys olivaceus in Korea. We isolated a new type of Scuticociliate from flounder. The parasite metamorphoses to ciliate and cyst phases with each other by environmental changes and survive for a relatively long span. The ciliate was measured average 41.8 ${\mu}m$ in length and 21.0 ${\mu}m$ in width, and cyst was 17.0 ${\mu}m$ and 13.5 ${\mu}m$, respectively. Nutritional condition was determined as a major parameter of metamorphosing between ciliate and cyst stages. The ciliate transforms to a cyst stage because of food shortage, and the cyst returns to a ciliate stage with a favorite environmental condition and shows active growth and reproduction. The ciliate multiplied at the maximal density of $2.9 {\times} 10^5 {m\ell}^{-1}$cells in vitro cultivation at $15 ^{\circ}C$temperature using MS BHI medium and bacterial food sources. The ciliate could be proliferated at a 2.5 to $30 ^ \circ}C$ temperature range, pH 6 to 9, and 1 to 55 ppt salinity. Particularly, it survived over one week at $0 ^{\circ}C$temperature showing a high resistance against unfavorable environmental conditions. And the cyst survived for 320 days in the condition of $5 ^{\circ}C$with no feeding, but its survival period was markedly shortened in higher temperature conditions. The chemotherapeutants (formalin and hydrogen peroxide) were clarified as effective chemicals against the ciliate during in vitro trials, but the effect of therapeutants differed in proportion, depending upon the density and the bathing time of chemical compounds.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.28-34
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• 2017

A new naked oat cultivar, 'Jungmo2005'(Avena nuda L.), was developed for food and forage use by National Institute of Crop Science, RDA in 2010. It was derived from a cross between $F_1$['Early80'/'Gwiri33'] and $F_1$['Early80'/'Gwiri23']. 'Early80', a covered oats, has early heading and high yielding, while 'Gwiri23' of covered type and 'Gwiri33' of naked type has early heading with large-size grain. 'Jungmo2005' has the characteristics of narrow and long leaves of pale green color, middle diameter culm of yellow color and medium grain of whitish yellow color. Cultivar 'Jungmo2005' had 2 days earlier heading date (May 9) than the check cultivar 'Seonyang' (May 11) in field condition. The 'Jungmo2005' showed better winter hardiness than that of the check cultivar, and similar to the check cultivar in respect to lodging resistance. The 'Jungmo2005' had 105 cm of culm length, 21.5 cm of spike length, 658 spikes per $m^2$, 82 grains per spike, 23.3 g of 1,000-grain weight, and 622 g of test weight. The grain yield of 'Jungmo2005' was averaged $3.38MT\;ha^{-1}$, which was 6% higher than that of the check. Average forage fresh and dry matter yield of 'Jungmo2005' harvested at milk-ripe stage were 44.8 and $12.6tone\;ha^{-1}$, respectively, compared with 47.5 and $12.5tone\;ha^{-1}$ of the check. The protein content of the 'Jungmo2005' was similar to the check (7.6% and 7.5%, respectively), while ADF (28.6%) and NDF (51.5%) were lower than the check (31.4% and 57.0%, respectively). TDN content and RFV were higher than those of the check (66.3%, 120.3 and 64.1, 105.2, respectively). 'Jungmo2005' is recommended for fall sowing cropping only in the south area where daily minimum mean temperatures are averaged higher than $-4^{\circ}C$ in January, and it should not be cultivated in mountain areas, where frost damages is likely to occur. The areas would do better only to sow in spring season.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.161-167
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• 2017

This experiment was conducted to comparison study on the productivity for certified varieties of import adaptability of silage corn in Pyeongchang area. Total eight varieties (Gangpyeongok, 31N27, 32P75, 32W86, P3156, P3394, DK 689 및 DK 729) were evaluated. The experimental design was 8 treatment of randomized block with three replications. Corn varieties were cultivated in experimental field of Pyeongchang campus, SNU from 1 May to 2 September, 2015 and plot size was $15m^2$. Plant height of 32W86 and ear height of Gwanpyeongok was the highest (p<0.05). Tasseling and silking date was 27 July-3 August and silking occurred after 1-3 day of tasseling. Average day to silking was 92 days and that of 31N27 variety was short (p<0.05). The varieties of DeKalbo Company (DK 689 and DK 729) required more times to silking. Average GDD (growth degree day) of eight varieties was $1,023^{\circ}C$ and P3352 was the lowest GDD. In the trials of resistance evaluation, P3394 was strong in disease, P3156 was the highest in insect. All varieties did not show the lodging and variety of DK 729 showed the highest stay green score (p<0.05). Average dry matter content was 30.77%, it showed higher trend in DM. 32W86 was the highest DM content among the varieties, but there was no significant difference among varieties (p>0.05). The weight per ear was the highest in 32W86 and the lowest in Gwanpyeongok. The ration of ear to whole plant was higher in 32W86 and P3394, but it was not found the significant difference (p>0.05). Average yield of fresh and DM was 59,017 and 13,476 kg/ha, respectively. DK 689 showed higher DM and TDN yield than others, but there was not significant difference (p>0.05). According to results, the difference of productivity was not found among certified variety of import adaptability of silage corn. The varieties Gwanpyeongok, 32W86 and 32P75 would be recommendable in Pyeongchang area for stable cultivation.

• Korean journal of applied entomology
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• v.25 no.2 s.67
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• pp.113-120
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• 1986

Soybeans collected from different locations in Korea were planted for tests of seed transmission of soybean mosaic virus (SMV). The percentage of seed transmission ranged from 20.5 to 29.5% in 14 seedlots including soybean cultivar Namhe and 12 to 19% in other 44 seedlots. However, no seed transmission of SMV was observed in soybean cultivar Younkiyongho. SMV was detected from embryo and cotyledon of soybean seeds. The infection of SMV was highly detected from premature seeds than from fully mature seeds, and higher from seeds harvested from plants infected before June 20 than plants infected around July 20 and August 20. No significant relationship was observed between seed transmission of SMV and mottling of seeds. The incidence of soybean mosaic disease followed by one month after peak of aphid population. The number of aphids was less on leaves of soybeans with short and dense trichomes whereas it was higher on leaves of soybean with long and sparse trichomes. Generally, the number of aphids was decreased on leaves with long and dense trichomes as the growth progressed. Soybean cultivar Columbus and 14 cultivars were susceptible, Chief and 14 cultivars were moderate, but Jangbaek and 17 other cultivars were resistant to SMV when inoculated with one isolate of SMV.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.461-468
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• 2012

In this study, photosynthetic parameters such as the net photosynthesis rate, stomatal conductance, intercellular $CO_2$ concentration, and transpiration rate were examined in selected ginseng varieties and/or lines that are resistant (Yunpoong, HTIR 1, HTIR 2, and HTIR 3) and susceptible (Chunpoong) to high temperature injury (HTI). The net photosynthesis rate increased with the increase in the light intensity in all the HTI-resistant and -susceptible ginseng lines with a light saturation point of $200\;{\mu}mol\;m^{-2}s^{-1}$, except for Yunpoong that had a light saturation point of $400\;{\mu}mol\;m^{-2}s^{-1}$. At the light saturation point, the net photosynthesis rate in July was highest in HTIR 3, at $4.2\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$, and was lowest in Yunpoong, HTIR 1, Chunpoong, and HTIR 2, in that order, at 1.9 to $3.7\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$. The net photosynthesis rate in August was highest in Yunpoong at $5.9\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$, and lowest in HTIR 1 and HTIR 3 ($4.5\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$) and in other lines, in that order, at 2.8 to $2.9\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$. The stomatal conductance in July was highest in HTIR 3 (0.055 mol $H_2O\;m^{-2}s^{-1}$) and Yunpoong, Chunpoong, HTIR 1, and HTIR 2 were 0.038, 0.037, 0.031, and 0.017 in that orders. In August, meanwhile, HTIR 1 showed the highest as 0.075, and followed by HTIR 3, Chungpoong, and HTIR 2 with 0.070, 0.047, and 0.023, respectively. The intercellular $CO_2$ concentration at the light saturation point in July and August was much lower in HTIR 2 at 139 and $185\;{\mu}mol\;mol^{-1}$ than in the other ginseng lines at 217 to 257 and 274 to $287\;{\mu}mol\;mol^{-1}$, respectively. The transpiration rate in July and August was higher in the HTI-resistant lines of Yunpoong, HTIR 1, and/or HTIR 3 at 0.83 to 1.03 and 1.67 to 2.10 mol $H_2O\;m^{-2}s^{-1}$ than in the other ginseng lines at 0.27 to 0.79 mol $H_2O\;m^{-2}s^{-1}$ and 0.51-1.65 mol $H_2O\;m^{-2}s^{-1}$, respectively. Conclusively, all the photosynthetic parameters that were examined in this study were generally higher in the HTI-resistant ginseng lines than in the HTI-susceptible lines, except for HTIR 2, and were much higher in August than in July, especially in the resistant ginseng lines. All these results can be used to provide basic information for the selection of HTI-resistant ginseng lines and the application of cultural practices that are efficient for ginseng growth, based on the photosynthetic characteristics of the lines.

• The Korean Journal of Mycology
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• v.41 no.3
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• pp.172-180
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• 2013

Grey mold infection rate in tomato was investigated with the inoculation of dead flowers on Botrytis selective media. The grey mold infection rate of flower after fruiting were higher in the order of after 45 days, after 25 days, and fruiting day with 100%, 87% and 65%, respectively. The number of infected flowers were increased with time increase after the flowering before fruiting. BSM (Botrytis selective medium) was used to check grey mold infection rate depending on the flowering stage and cultivar. Grey mold infection rate depending on the flowering stage was similar in all the beef-tomato cultivar as 1.5~5% at preflowering, 1.5~45% at flowering and 75~90% at fruiting. On the other hand, cherry tomato cultivar "KoKo" had lower infection rates of 0~3.5% at pre-flowering, 10~30% at flowering and 20~50% at fruiting. These resulted from the fact that beaf-tomato cultivar have much bigger flowers and larger amount of pollens compared to those of cherry tomato cultivar. The amounts of falling pollens of Botrytis spp. were checked for beaf-tomato cultivar and cherry tomato cultivar using BSTM. The amounts of falling pollens were increased as growth period was extended, and the amount of spores increased rapidly during the outbreak of grey mold. Twelve field trials in Buyeo and Iksan areas showed that Fluazinam, and Diethofencarb+Carbendazim were effective fungicides to control tomato grey mold, and these results were similar to those of field trials with BSTM. This is the first report of Fluazinam as a effective fungicide for the control of grey mold of tomato even though it has not been registered yet for the control of gray mold in tomato.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.7-15
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• 2012

Agronomic characteristics of 150 adzuki bean ($Vigna$ $angularis$ W.F. Wight) germplasm collected in Korea were investigated in order to establish basic data for the improvement of crop breeding. Growth types were classified as 3 types of indeterminate type, determinate type, and semideterminate type, of which indeterminate type was the highest percentage of 96.6%. Seed color were classified as 8 colors of which dark brown took 66.5% in 150 adzuki bean germplasm. Days from seeding to maturity showed the range from 89 to 142 days with 115 days in the average and the highest frequency proportion was 37.2% of the group from 131 to 140 days, and the next was 27.3% of the group from 121 to 130 days among 150 germplasm. Pod length showed the range from 5.9 to 10.1 cm with 7.8 cm in the average and the highest frequency distribution of it was the group from 7.1 to 8.0 cm with the proportion of 45.1% and the next was the group from 8.1 to 9.0 cm with the proportion of 32.2%. Number of pods per plant showed the range from 5.0 to 132.5 pods with 28.5 pods in the average and the highest frequency distribution of it was the group from 11.0 to 20.0 pods with the proportion of 30.8% and the next was the group from 21.0 to 30.0 pods with the proportion of 28.6%. Number of seeds per pod showed the range from 5.3 to 11.3 seeds with 8.2 seeds in the average and the highest frequency proportion of it was the group from 7.1 to 8.0 seeds, which occupied 32.2% among 150 germplasm. 89.3% of 150 germplasm showed the resistance to shattering of grains at harvest period. 100 grain weight showed the range from 5.7 to 23.0 g with 12.9 g in the average and the highest frequency proportion of it was the group from 9.01 to 13.0 g, which occupied 43.3% and the next was the group from 13.01 to 17.00 g with the proportion of 28.5% of 150 germplasm.