• Title/Summary/Keyword: 천이 조건

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Characteristics of Pesticide Runoff and Persistence on Agricultural Watersheds in Korea (영농지역에서 작물재배 형태에 따른 농약의 잔류성과 유출특성)

  • Park, Byung-Jun;Kwon, Oh-Kyung;Kim, Jin-Kyoung;Kim, Jin-Bea;Kim, Jin-Ho;Yoon, Soon-Kang;Shim, Jae-Han;Hong, Moo-Gi
    • Korean Journal of Environmental Agriculture
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    • v.28 no.2
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    • pp.194-201
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    • 2009
  • To evaluate the exposure of non-point source pesticide pollution in agricultural watershed and to investigate pesticide distribution and runoff from agricultural land, paddy field, upland and orchard, this experiment was carry out during crop growing seasons. The pesticide were detected twenty pesticides fungicide 4, insecticide 10, herbicide 6) in water of Neungchon agricultural watershed and detection concentrations were range 0.008${\sim}$7.59 ppb. Most of the detection pesticides were using pesticides to rice paddy fields to control fungi, insects, weeds. During the crop cultivation, the pesticide were detected total thirty pesticides by pepper field soil 6, orchard soil 4, sesame field soil 3 and rice paddy field soil 5, and pesticide concentrations were range 0.001${\sim}$0.109 ppm. Especially the herbicides were detected mainly in May and June in the stream water. The pesticide were detected thirty pesticides by fungicide 2, insecticide 6, herbicide 5 in water of Jungam Koseong agricultural watershed and detection concentrations were range 0.01${\sim}$7.21 ppb. In regard to the detected pesticides, the concentration of individual pesticides measured in surface water of the study areas never exceeded guidelines for agriculture chemicals concerning water quality-effluent from paddy fields in Japan (Katayama, 2003). Runoff rate of pesticides was range 0.07${\sim}$3.06 % from Kongju agricultural land to watershed after applied pesticides.

Studies on the Storage Condition for Tricholoma giganteum Mycelium (왕송이버섯(Tricholoma giganteum)균의 저장조건)

  • Cheong, Jong-Chun;Park, Jeong-Sik;Jang, Kab-Yeul;Jhune, Chang-Sung;Lee, Chan-Jung;Kim, Seung-Hwan
    • The Korean Journal of Mycology
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    • v.35 no.2
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    • pp.81-84
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    • 2007
  • In some cases, the problem with the mycelium of Tricholoma giganteum is delayed mycelial growth or non-regeneration. Therefore, this study was conducted to understand the mycelial storage condition of T. giganteum and to investigate the regeneration ratio of mycelial growth. T. giganteum obtained from KACC in RDA was evaluated for its simple preservation at $10^{\circ}C$ and subcultured on different media. Mycelium of T. giganteum was cultured on the PBA (potato bamboo extract medium) for seven days at $30^{\circ}C$. Using simple preservation method, the mycelium of T. giganteum (MKACC 50852) and Pleurotus ostreatus (Chunchu No. 2) were stored on six different media in two kinds of storage vessels (tube and vial) for a period of 1-12 months at $4^{\circ}C,\;15^{\circ}C$, and $25^{\circ}C$ storage temperatures. At $4^{\circ}C$ storage condition, mycelial regeneration was failed in all agar media, but was successful in the sawdust medium for 3 months. At $15^{\circ}C$ storage, mycelial activity was maintained up to six months. On the other hand, P. ostreatus produced well-regenerated mycelia both at $4^{\circ}C$ and $15^{\circ}C$ storage up to 12 months. In conclusion, it is estimated that the mycelia storage condition of T. giganteum must be done at $15^{\circ}C$ and subcultured within six months.

Removal of Arsenite by Nanocrystalline Mackinawite(FeS)-Coated Alumina (나노크기 매킨나와이트로 코팅된 알루미나에 의한 아비산염의 제거)

  • Lee, Seungyeol;Kang, Jung Chun;Park, Minji;Yang, Kyounghee;Jeong, Hoon Young
    • Journal of the Mineralogical Society of Korea
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    • v.26 no.2
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    • pp.101-110
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    • 2013
  • Due to the large specific surface area and great reactivity toward environmental contaminants, nanocrystalline mackinawite (FeS) has been widely applied for the remediation of contaminated groundwater and soil. Furthermore, nanocrystalline FeS is rather thermodynamically stable against anoxic corrosion, and its reactivity can be regenerated continuously by the activity of sulfate-reducing bacteria. However, nanocrystalline mackinawite is prone to either spread out along the groundwater flow or cause pore clogging in aquifers by particle aggregation. Accordingly, this mineral should be modified for the application of permeable reactive barriers (PRBs). In this study, coating methods were investigated by which mackinawite nanoparticles were deposited on the surface of alumina or activated alumina. The amount of FeS coating was found to significantly vary with pH, with the highest amount occurring at pH ~6.9 for both minerals. At this pH, the surfaces of mackinawite and alumina (or activated alumina) were oppositely charged, with the resultant electrostatic attraction making the coating highly effective. At this pH, the coating amounts by alumina and activated alumina were 0.038 and 0.114 $mmol{\cdot}FeS/g$, respectively. Under anoxic conditions, arsenite sorption experiments were conducted with uncoated alumina, uncoated activated alumina, and both minerals coated with FeS at the optimal pH for comparison of their reactivity. Uncoated activated alumina showed the higher arsenite removal compared to uncoated alumina. Notably, the arsenite sorption capacity of activated alumina was little changed by the coating with FeS. This might be attributed to the abundance of highly reactive hydroxyl functional groups (${\equiv}$AlOH) on the surface of activated alumina, making the arsenite sorption by the coated FeS unnoticeable. In contrast, the arsenite sorption capacity of alumina was found to increase substantially by the FeS coating. This was due to the consumption of the surface hydroxyl functional groups on the alumina surface and the subsequent occurrence of As(III) sorption by the coated FeS. Alumina, on the surface area basis, has about 8 times higher FeS coating amount and higher As(III) sorption capacity than silica. This study indicates that alumina is a better candidate than silica for the coating of nanocrystalline mackinawite.

Diurnal Changes of Leaf Water Potential in Cuttings (삽수(挿穗)의 Leaf Water Potential의 변화(變化))

  • Hong, Sung Cheon
    • Journal of Korean Society of Forest Science
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    • v.38 no.1
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    • pp.27-32
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    • 1978
  • The diurnal pattern of leaf water potential in cuttings by Dye Method was as follows: 1. Diurnal pattern of leaf water potential (${\psi}_l$) in Viburnum Awabuki K. Koch and Daphne odora Thunb. was shown the pattern of the curves without mutual relation with soil classes when soil water potential (${\psi}_s$) was 0 bar. When ${\psi}_s$ was above -0.01 bar, the cuttings in the loamy sand (L.S.) was shown by the maximum values than that in sandy clay (S.C.) by about -1 bar gap (Fig. 1). 2. The diurnal changes of ${\psi}_l$ was shown the most high from two to eight O'clock in the morning, the maximum value was -3 bars when ${\psi}_s$ was above -0.01 to -0.02 bar, and was -4 bars below -0.03 bar. The diurnal the lowest values of ${\psi}_l$ showed -20 to -22 bars from one to two O'clock in the afternoon. In the fifteenth day after cutting V.A., the staying time in the diurnal maximum values of ${\psi}_l$ is about half in comparison with it in the fifth day. The curves of recovery of water stress (Fig. 1), the former reached to the diurnal maximum values -1 to -2 bars lately every hours comparing with it of the latter. The general diurnal pattern of ${\psi}_l$ was most clearly related to change with air temperature and the relative humitidy. 3. Comparing the treatment block by IAA 50 ppm with controlled block in fifteenth day after V.A. cuttings, in case of treatment reached to maximum values -2 to -3 bars lately as shown Fig. 2., and also staying times was only half in comparison with controlled block. 4. The cuttings 4 leafs was much rootings than 2 leafs in V.A. (Table. 1), and the former reached maximum value -2 to -3 bars lately every hours comparing with the latter. 5. In case of Buxus microphylla var. Koreana as shown Fig. 3., comparing the pattern curves of in the cuttings 8 leafs with 4 leafs, the former reached to maximum values -2 to -3 bars lately in comparison with the latter, but reffering to the amount of rooting (Table. 2), the former is less than the latter.

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Antioxidant activity of the Sumaeyaksuk tea extracts prepared with different drying and extract conditions (건조 및 침출 조건에 따른 섬애약쑥 침출물의 항산화활성)

  • Hwang, Cho-Rong;Seo, Weon-Taek;Jung, Min-Jung;Shin, Jung-Hye
    • Food Science and Preservation
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    • v.20 no.4
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    • pp.546-553
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    • 2013
  • In this study, we examined the antioxidant activity of the Sumaeyaksuk (Artemisia argyi) tea extracts from different pre-treatment and extraction methods. Sumaeyaksuk was sun-dried for 3.5 days (control, RC) and aged at a temperature of $60^{\circ}C$ for 3.5 days (HA), 7 days (HB), and 14 days (HC), respectively. Each sample was extracted in $60^{\circ}C$ and $95^{\circ}C$ hot water for 2 minutes. The soluble solids content of HA from the $60^{\circ}C$and $95^{\circ}C$ hot water extraction were $0.52{\pm}0.18%$ and $0.92{\pm}0.18%$, respectively. The soluble solids content was increased by the higher extraction temperature. The reducing sugar content of RC was $9.55{\pm}0.18mg/g$ in the $95^{\circ}C$ extraction, which was significantly higher than in the $60^{\circ}C$ extracted sample. However, the reducing sugar content did not show a remarkable difference based on aging periods. The total phenolic compound content of the $95^{\circ}C$ extracted samples was $3.36{\pm}0.13{\sim}9.88{\pm}0.23mg/g$, which was significantly higher than that of the $60^{\circ}C$ extracted sample. The ABTS radical scavenging activity of the $60^{\circ}C$ extracted RA and HA samples were 35.63% and 95.10%, respectively. Moreover, the radical scavenging activity increased to 63.35% and 96.78%, respectively, in the $95^{\circ}C$ extracted samples. As a result of the high temperature, the extracted sample showed an increase in the FRAP. In the RC sample, the FRAP was two times higher in the $95^{\circ}C$ extracted sample ($181.28{\pm}2.90{\mu}M$) than in the $60^{\circ}C$ extracted sample ($83.88{\pm}0.43{\mu}M$).

A Study on the Men's Fashion Trend through the Statistical Analysis (통계적 분석을 통한 남성 패션 트렌드 연구)

  • Kim, Yoon-Kyoung;Lee, Kyoung-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.6 s.165
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    • pp.837-847
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    • 2007
  • 1,098 pieces of photographs($1995{\sim}2002$) of men's suit style have been classified according to fashion images in order to examine features and change aspects with statistical analysis. The findings of examining features of the trend by year with test of homogeneity, correspondence analysis, biplots, correlation analysis and regression analysis are as follows: (a) there are significant differences on fashion images as the trend by yew with test of homogeneity, (b) there are remarkable differences on the fashion trend by year with correspondence analysis and biplots. (c) There are significant correlations for appearance among fashion images by its frequency through correlation analysis, and (d) it is assumed that fashion images are going to be gradually outstanding according to regression analysis.

Effect of Pollination Method on Fruit Setting and Quality of Oriental Melon(Cucumis melo L. var, makuwa Makino) (착과방법이 참외의 착과 및 품질에 미치는 영향)

  • Shin Yong Seub;Park So Deuk;Kim Jwoo Hwan;Kim Byung Soo
    • Journal of Bio-Environment Control
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    • v.14 no.2
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    • pp.83-88
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    • 2005
  • A study was conducted on three pollination methods on oriental melon(sageageol-ggul) grafting with pumpkin(seongjutozoa) for the labor-saving and to improve fruit set. Fruit weight, flesh thickness and fruit setting rate of oriental melon were greater in growth regulators treatment than those of pollinated by bees. Sugar content and hardness of fruits pollinated by bees were higher than those of by growth regulators. From the last ten days of the February to the first ten days of the March, fruit setting rate was $95\%$ in fruit setting growth regulators, whereas it was $46\%$ and $45\%$ in pollinated by honey and bumble bee, respectively. After the middle of March, the percentage of fruit setting was >$98\%$ in all the pollination methods. The cultivation under plastic houses of oriental melon, suitable fruiting time far the pollination by bees was decided after middle days of the March. Chromaticity and especially the value of 'a' of fruit of oriental melon pollinated by bees were higher than those of growth regulators. The percentage of fermented fruits of bee pollinated and growth regulators treated was $6.7\~9.1\%\;and\;28.1\%$, respectively. The weight of 100 seeds of bees pollinated were higher than that of growth regulators. The more increased the weight of 100 seeds the less appeared the rate of fermented fruits. The percentage of marketable fruits of the honey and bumble bee pollinated and that of growth regulators treated was $82\%,\;80.3\%\;and\;62.5\%$, respectively. The decreasing rate of fruit weight during storage of bees pollinated was less than those of growth regulators. In these results, the introduction of honey bee and bumble bee for the pollination of oriental melon was able to labor-saving of fruit set and increase of fruit quality.

Effects of Climate Change on C4 Plant List and Distribution in South Korea:A Review (기후변화에 따른 국내 C4 식물 목록과 분포 변화:고찰)

  • Kim, Myung-Hyun;Han, Min-Su;Kang, Kee-Kyung;Na, Young-Eun;Bang, Hea-Son
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.13 no.3
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    • pp.123-139
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    • 2011
  • It is expected that identification and lists of $C_4$ plants in specific regions are useful not only for the ecological researches that are related to vegetation phenology and succession but also as an index of climate change. In this review, $C_4$ plants growing in South Korea were listed and their life forms were investigated. In addition, we discussed the influences that climatic change and the $C_4$ plants exerted on plant ecosystem. Photosynthetic pathway types ($C_3$ and $C_4$) for the plant species in South Korea were determined by reviewing the scientific literatures published between 1971 and 2010. Of the total 4476 species in 1123 genera and 197 families, 206 species (4.6%) in 84 genera (7.5%) and 21 families (10.7%) were identified as $C_4$ plants (including $C_3$-$C_4$ intermediate plants). Among the identified $C_4$ species, 53 species (25.7%) in 26 genera and 15 families were classified as Dicotyledoneae, while 153 species (74.3%) in 58 genera and 6 families were classified as Monocotyledoneae. The majority of the $C_4$ species belong to four families: Chenopodiaceae (15 species), Amaranthaceae (13 species), Gramineae (102 speceis) and Cyperaceae (45 species). With respect to life form composition of 206 $C_4$ species, Th-$R_5$-$D_4$-t was most dominant: 95 species (46.1%) were included in Th, 123 species (59.7%) in $R_5$, 179 species (86.9%) in $D_4$, and 122 species (59.2%) in t. The projected increase in temperature due to climate change may provide better conditions for the growth of $C_4$ plants. Such a result will have considerable impacts on the interspecific competition between $C_3$ and $C_4$ plants, the distribution of $C_4$ plants, plant phenology, and plant diversity.

Changes on Growth, Photosynthesis and Pigment contents of the Maackia amurensis and Viburnum opulus var. calvescens under Enhanced Temperature and CO2 Concentration (온도와 CO2 농도 증가에 따른 다릅나무와 백당나무의 생장, 광합성 및 광색소 함량 변화)

  • Han, Sim-Hee;Kim, Du-Hyun;Kim, Gil-Nam;Lee, Jae-Cheon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.13 no.3
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    • pp.115-122
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    • 2011
  • The impacts of elevated temperature and $CO_2$ were studied on the seedlings of Maackia amurensis and Viburnum opulus var. calvescens. The seedlings were grown in controlled-environment growth chambers with four combinations of temperature and $CO_2$ treatments: $25^{\circ}C$ + ambient $CO_2$ (400 ppm), $25^{\circ}C$ + elevated $CO_2$ (800 ppm), $30^{\circ}C$ + ambient $CO_2$ (400 ppm), and $30^{\circ}C$ + elevated $CO_2$ (800 ppm). Under elevated temperature and $CO_2$ concentration, the dry weight decreased in seedlings of M. amurensis, but increased in seedlings of V. opulus var. calvescens. In addition, the shoot to root (S/R) ratio in M. amurensis reduced but that of V. opulus var. calvescens increased under elevated $CO_2$ concentration. The S/R ratios of two tree species increased under higher temperature. M. amurensis represented lower carboxylation efficiency under higher temperature and $CO_2$ concentration and that of V. opulus var. calvescens showed lower values under the only higher temperature. Photosynthetic pigment content of in the leaves of M. amurensis was lower under higher $CO_2$ concentration and higher under the increase of temperature, but that of V. V. opulus var. calvescens decreased according to the increase of temperature. Chlorophyll a/b ratios of M. amurensis and V. V. opulus var. calvescens decreased obviously with the increase of $CO_2$ concentration and temperature, respectively. In conclusion, the growth and physiological responses under the environmental changes such as temperature and $CO_2$ concentration depend on the tree species. Therefore, more studies are needed to predict the response of each tree species against the climate changes.

Improvement of Herbicide Use in Crop Production. X. Interpretations in Tank - mix Use of Aciflurofen and Haloxyfop - methyl for Weeding on Late - season Cropped Soybeans (Glycine max L.) (제초제(除草劑)의 사용법(使用法) 개발(開發)을 위한 연구(硏究) - X. 만파대두(晩播大豆)의 잡초방제(雜草防除)를 위한 Acifluorfen과 Haloxyfop-methyl의 혼용효과(混用效果) 해석연구(解析硏究))

  • Guh, J.O.;Lee, K.;Kim, D.K.;Hong, S.H.
    • Korean Journal of Weed Science
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    • v.5 no.1
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    • pp.73-84
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    • 1985
  • 25 tank-mixed combinations between Haloxyfop-methyl at 0, 0.05, 0.1, 0.15 and 0.2 kg ae/ha and Acifluorfen at 0, 0.082, 0.163, 0.245 and 0.326 kg ai/ha were applicated at post-emergence on the late-season cropped soybean(Glycine max) fields predominated by grasses and assessed on the weeding efficacy. A most abundant weed species on the experimented fields were found at September (25 species). The broadleaved weed species and sedges were successively and proportionately emerged by the control rate of grass species. From the mono-treatment of each herbicide, Haloxyfop-methyl was recognized as a highly selective one between grasses and soybean, and Acifluorfen between broadleaf weeds and soybean, respectively. By combined application with both herbicides a synergistic weeding efficacy was detected on total weed species, however antagonistic or additive on each weed groups. Among other traits of soybean, stem dry weight was influenced by weed competitions during October, number of pods per plant during August and seed yields during whole periods. For most effective and reasonable weeding, no less than 0.4 kg ai/ha of each herbicides should be applicated in combinations.

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