• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.139-144
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• 1977

The green peach aphid Myzus persicae(Sulzer), is known as the most important vector of potato leaf-roll virus and PVY. Yield of potato plants infested with these viruses are remarkably lower than non-infested plants. A study was conducted to investigate the life history of the green peach aphid at Suweon, Korea (Lat. $37^{\circ}$'N., Long. $126^{\circ}59$'E). The following were obtained: 1. Overwintering eggs hatched from late March to early April, with a hatching rate averaging ninety-five percent. 2. The fundatrigeniae leave the primary host(Punus persica) in early to mid May and migrate to the secondary hosts. 3. From mid to late Oct., the gymnoparae migrate from the secondary hosts to the primary hosts. 4. From early to mid Nov., gymnoparae lay fertilized eggs around buds, in bark crevices, or between bifurcated twigs of the primary hosts. 5. The early-born progeny have 23 generations and the late-born progeny have 9 generations on peach trees, potatoes and raddish from Apr. to Oct. 6. The average length of life was about 28.5 days, with a developmental period of approximate 10.8 days and a reproductive period of 15.8 days. 7. The average number of nymphs produced by a female was fifty, with a maximum number of 118. 8. The average number of nymphs produced by a female per day was about 3.2, with a maximum number of 13.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.87-98
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• 2024

This study was conducted to investigate the efficiency of the filtering sets composed of fiberboards, which were fabricated with lignocellulosic fiber and cork oak bark-based activated carbon (COA), as well as traditional Korean paper handmade from mulberry trees (KP) for the filtration of PM, TVOC and HCHO. Three-layers fiberboards (WRF) were fabricated with wood fiber in its surface layers and recycled fiber/COA in its core layer using a protein-based adhesive with the resin content of 8%. Filtering sets were composed of three WRF and one sheet of KP. Concentrations of PM, TVOC and HCHO generated with the combustion of a incense in a sealed laboratory hood were reduced efficiently with the operation of air-purifier installed the filtering sets. Except for the WRF fabricated with 4%/4% resin contents, other WRF were prepared with 5%/3% and 6%/2% resin contents in surface/core layers, and then the WRF were used with KP for the fabrication of filtering sets. Filtration efficiency of the filtering sets was improved as the core-layer resin content applied in the fabrication of WRF decreased. In addition, filtration efficiency of the WRF-based filtering set fabricated with KP of 25 g/m² basis weight was higher than that with KP of 45 g/m² basis weight. Filtering sets composed of three-layers fiberboards (RWF) that recycled fiber and wood fiber/COA were used in its surface and core layers, respectively, and KP-25g showed higher filtration efficiency than those of WRF-based filtering sets. Air-inhalation equipment installed the RWF-based, WRF-based filtering sets and without filtering set were operated in small indoor and large outdoor spaces. Efficiency for filtering PM and TVOC of the RWF-based filtering sets was higher than that of other filtering sets. It is concluded that fiberboard-based filtering sets composed of RWF and KP-25g can be used as a filter for reducing the concentrations of PM and TVOC existed in indoor and outdoor spaces.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.33-40
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• 2008

Objectives : In order to distinguish morphological characteristics, because the inside portion of the root bark of Scutellariae Radix decomposes as time goes by, 2nd, 3rd, and 5th year Scutellariae Radix were sampled and compared according to their external, internal, and flour states through optical microscope. Methods : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and the flour of it was mounted by the liquid made by the same ratio of each of glycerin, acetic acid, and water, and then observed and photographed by olymphus-BHT. Results : 1. The inside of 2nd year Scutellariae Radix was rich and golden, the transverse section of Scutellariae Radix that was 3rd years of age was golden, but there were many Scutellariae Radix whose center portion turned redish brown, and the center portion of 5th year Scutellariae Radix had been decomposed or empty. 2. 2nd year Scutellariae Radix had the most starch grain, 5th year Scutellariae Radix had the least, and the middle portion of xylem that was 5 years of age had a cell ring that was corkish, but 2nd and 3rd year Scutellariae Radix did not have it. 3. In the flour state, 2nd, 3rd, and 5th year Scutellariae Radix did not have any difference, but the amount of starch grain was the most in 2nd year Scutellariae Radix and the least in 5th year Scutellariae Radix.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.4
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• pp.81-89
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• 2016

This study aims to understand the relationship between visitors and the degradation of natural resources in Bukhansan national park. We analyzed the trend of the number of visitors, destruction of natural resources and decrease of biodiversity per year. We further compared three types of trails, heavily-used trails and rarely-used trails and a trail with limited access, regarding the degree of destruction in the National Park through a field survey. Our result showed that increasing number of visitors had direct and indirect impact on the destruction of natural resources in the National Park. The direct impact came from visitors' excessive use of trails. Naturally, increasing number of visitors caused an immoderate use of natural resources. Physical degradation such as exposure of tree root, poor drainage of trails, trail erosion was more severe than other types of trails. Decreasing biodiversity or mild disturbance around trails is the indirect impact such as broken bough, worn-bark in rarely-used trails. Destruction scale greatly increased as the number of visitors increased. Real-named reservation system helped to prevent trails from degradation. Our result calls for the need of controlling the number of visitors to Bukhansan National Park to mitigate the degradation. We recommend dispersing visitors from the heavily-used trails to other trails and implementing real-named reservation system in the rarely-used trails for the effective management of the national park.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.755-760
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• 2016

In general, the storage life of hardy kiwifruit (Actinidia arguta) is approximately one month, even in cold storage, which is a limiting factor for its commercialization due to the short marketing period. This short shelf life is in contrast to those of green kiwifruit (A. deliciosa, 6 to 8 months) and gold kiwifruit (A. chinensis, 4 to 6 months). To increase the storage life of hardy kiwifruit, we performed a cross between A. arguta (a local collection, 'Hy2-1', female) and A. deliciosa ('Matua', male) at Wando station at the Fruit Research Institute of JARES, Korea in 1999. After the first selection in 2006, we clonally propagated the hybrid plants by grafting them onto A. arguta seedlings in Gwangyang and Haenam province, Korea. We performed the final selection of this cultivar in 2012 and applied for plant protection rights from the Korea Forest Research Institute in 2013. Several experimental orchards have been established for commercial production. 'Mansu' begins to flower on May 20 in Gwangyang. The horticultural maturity date in 'Mansu', when the soluble solid content reaches $7^{\circ}Bx$, is October 15, whereas that of the control variety ('Chiak') is October 5. The average fruit size of 'Mansu' is approximately 15 g. The soluble solid content of 'Mansu' is approximately 16 to $17^{\circ}Bx$ after ripening. The total yield of mature 'Mansu' vines is estimated to be 2.2 to 2.5 tons per 10a. The fruit firmness of 'Mansu' exceeded 1.5 kg/5 mmØ until 70 days after storage (at 0 and $1^{\circ}C$). Therefore, 'Mansu' fruits have much longer storability than the control. The cultivation and production of 'Mansu' may extend the marketing period for hardy kiwifruit.

• Journal of the Korean Society of Food Culture
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• v.26 no.4
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• pp.374-382
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• 2011

The origin of Korean traditional food's spicy taste dates back to the first telling of the Dangun myth-a story of a tiger and bear who tried to reincarnate themselves in human form by eating garlic and wormwood. For a long time, Koreans have eaten spicy vegetables such as green onion, garlic, ginger, mustard, leeks, corni, cinnamon bark, and Chinese peppers (Zanthoxylum schinfolium) and Zanthoxylum bungeanum. In prehistoric times, spicy vegetables were probably used to eliminate the smell of meat. In the agricultural age, they were used to supplement meals with fresh taste. They were also used as a substitute for salt (salt was very precious and expensive) as well as side dishes for the poor. Spicy vegetables have also been used as a substitute for main dish like medicinal gruel and used to increase the spiciness of soup, and they are usually used as a side dish and with condiments in namul (cooked vegetable dishes), sangchae (salad), ssam (wrapped in greens and garnished with red-pepper paste or other condiments) and Kimchi. In addition, chili pepper was introduced to the Korean Peninsula in the middle of the Joseon Dynasty (mid-15th, 16th century). The soil and climate of the Korean Peninsula are suitable to growing chili pepper, and chili pepper has excellent adaptability and productivity. Accordingly, it is processed to red pepper powder and has become a major part of traditional Korean food along with Chinese pepper. Since the Joseon Dynasty, many kinds of Kimchi made with red pepper powder have been developed, and most Koreans enjoy them these days. The main characteristics of Korean food are spiciness and honest-to-goodness taste.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.233-236
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• 1984

Studies were conducted to investigate the effect of Carbofuran 3G on the density variation of rice pests and their natural enemies in case the insecticide was treated two times as compared with usual trials in paddy field. Even the two times application of Carbofuran 3G in the nursery boxes of machine transplanting and paddy water trials obtain same results to pests, small brown planthopper (Laodelphax striatllus), green rice leafhopper (Nephotettix cincticeps), brown planthorper (Nilaparvata lugens), white back planthopper (Sogotella furcifera), rice stem bore (Chilo suppressalis), rice stem maggot (Chlorops oryzae), rice thrips (cloethrips oryzae) as compared with usual trials. The density of natural enemies, spiders and egg parasite, Anagrus sp. of planthoppers in the two times application part of Carbofuran 3G increased 2.4 fold as compared with usual trials.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.57-62
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• 2003

The Mechanical and drying characteristics of Pinus densiflora wood, which was damaged by forest fire, and sound wood were examined. There were no significant differences in axial compressive properties, shearing strength and impact bending absorbed energy between damaged and sound woods. But the bending properties of damaged wood were slightly higher than those of sound wood. The green moisture content of sapwood in damaged wood was lower than that in sound wood, but oven-drying rate was similar in both woods. Number of initial check in damaged wood was smaller than that in sound wood, and inner check in damaged and sound woods was not observed. Consequently, it is considered that mostly damaged wood by forest fire can be used for wood material after removing the bark.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.375-382
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• 2015

The insecticidal activity of the constituents of cinnamon essential oils and structurally related compounds against both the nymphs and adults of the citrus flatid planthopper Metcalfa pruinosa was examined using a direct-contact application. The toxicity of the cinnamon oil constituents and 21 (E)-cinnamaldehyde related compounds regarding the nymphs of M. pruinosa was evaluated using a leaf-dipping bioassay. Based on 24 h $LC_{50}$ values, hydro-cinnamic acid ($1.55mg/cm^2$) is the most toxic compound, followed by geranic acid ($1.59mg/cm^2$). The $LC_{50}$ values of 11 of the compounds including cinnamaldehyde are between $1.60mg/cm^2$ and $4.94mg/cm^2$. Low toxicities and no toxicity were observed with the other 15 ($5.24mg/cm^2$ to $13.47mg/cm^2$) and two compounds, respectively. Also, the toxicities of the cinnamon oil constituents and 21 cinnamaldehyde related compounds regarding the M. pruinosa adults were evaluated using a direct-spray method. The toxicity of eugenol (10.81 mg) is the most toxic compound for the adults of M. pruinosa, followed by geranic acid (30.68 mg). The $LC_{50}$ values of nine of the compounds including cinnamaldehyde are between 59.16 mg and 96.70 mg. Low toxicities and no toxicity were observed with the other 15 (105.44 mg to 255.76 mg) and three compounds, respectively. The spray formulations that comprise cinnamon bark and cinnamon green leaf oils resulted in 82.3% and 82.9% mortalities, respectively, toward the M. pruinosa adults in a ginseng field. Global efforts to reduce the level of highly toxic synthetic insecticides in agricultural environments justify further studies on cinnamon oils to ascertain whether the corresponding active principles can act as insecticides, when they are applied as a direct spray with contact action, for the control of M. pruinosa populations.

• Research in Plant Disease
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• v.13 no.3
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• pp.152-156
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• 2007

Incidences of leaf blight of lily cultivars Raizan and Casa Blanca in the open field cultivation were 50% and 45.4%, respectively, while those in the green house cultivation were significantly reduced to 1.5% and 1.9%, respectively, In the green house, the incidences of the disease in sprinkler watering cultivation were $14.5{\sim}16.5%$, while those in drip watering cultivation were only $1.5{\sim}2%$. Incidence of the disease was severe in the field where the lily was cultivated successively for 2 to 3 years. Isolation frequencies of B. elliptica from overwintered plant debrises such as leaves, stems, capsules, and bulbs were 43.3%, 46.7%, 60% and 0%, respectively, while those of B. cinerea were 10.3%, 0%, 3.3% and 0%, respectively, Incidence of leaf blight in the field where diseased plant debris was cleaned was 7.3%, while that in the field where diseased plant debris was not cleaned was 56.5%. Incidences of the disease in the field where coverages of soil surface with black vinyl, bark or rice straw were used were 6.6%, 8.2% and 11.3%, respectively, while that in the field where the coverage was not used was 21.3%.