• Title/Summary/Keyword: Seasonal characteristics

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The autecology of Zostera marina and Z. japonica at Sagumi Bay in the southwestern coast of Korea (남해 서부연안의 사구미 만에서 거머리말(Zostera marina)과 애기거머리말(Z. japonica)의 개체생태학)

  • Ok, Jae-Seung;Lee, Sang-Yong
    • Journal of Environmental Science International
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    • v.23 no.9
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    • pp.1563-1572
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    • 2014
  • The autecology of the Zostera marina and Z. japonica was studied in populations growing in the same locality (Sagumi Bay, southwestern coast of Korea). Environmental factors and plant characteristics were examined monthly from August 2008 to September 2011. Along intertidal zone, Z. japonica (0.1-0.5 m above mean lower low water, MLLW) occurred above Z. marina (0.5-2.5 m MLLW). Tidal exposure at low tide during day was the highest in the spring and the lowest in the summer. Underwater Irradiance showed seasonal fluctuation that was the highest in spring and summer caused by tidal pattern. Strong seasonal patterns in water temperature appeared to control the seasonal variations in morphology, biomass and leaf growth. The seasonal pattern of Z. japonica resembled that of the Z. marina in morphological characteristics, above-and below-ground biomass, whereas it differed in shoot density and leaf elongation. Despite some similarities in seasonal growth patterns, the patterns of Z. japonica were lagged by 2 month of Z. marina. Seasonal variation in the above biomass of Z. marina was caused by changes in density and plant size, whereas that of Z. japonica was mainly caused by changes in shoot density. Zostera marina was more sensitive to high temperatures than Z. japonica, and the increasing water temperature during the summer became the factor that inhibits the growth of the Z. marina. Zostera Japonica, there is no clear change according to the amount of the light. It is because its habitat locates above that of Zostera marina so that the amount of the light that is necessary to growth is enough and in this condition, any preventing factor does not seem to work at all. Although underwater light getting into Zostera marina's habitat is very low level and there is no any hindrance to the survival of them, it prevents them from their productivity a bit.

Assessment of Traditional Knowledge on Seasonal Customs and Its Characteristics for Practical Use (세시풍속 전통지식기술의 개발가치 평가와 활용방안 분석)

  • Kim, Mi-Heui;Park, Duk-Byeong;Ahn, Yoon-Soo;Jun, Young-Mi
    • The Korean Journal of Community Living Science
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    • v.17 no.4
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    • pp.175-197
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    • 2006
  • This study aims to assess the traditional knowledge on seasonal customs and its characteristics for practical use. The Delphi method and correspondence analysis were hired to collect and analysis the data. Twenty six professionals for the Delphi participated in three-round process. The followings were concluded. The number of items valuing and resourcing for seasonal customs. were 118(40 for folks and ceremonies, 53 for foods. 25 for plays) on Delphi results. For example are Bokjori, Dano fm, Bokjumeoni, Chuseok, Tano festival, New Year Card, washing hair with an iris, Soup with rice cake, Boiled rice with five cereals, Rice and red-bean porridge, Kimchi-making for the winter, Sharing walnut with friends, Game of yut, Playing kite, Play with Hanga etc. Nowadays the ideas of modernized practical use on seasonal customs was to connect with modernized scientific technology and designate commemoration day. The items for connecting with modernized scientific technology were new year card, painting and recording sound with traditional seasonal customs, food areas, cake with seven kind of cereals, play areas, hand wrestling, cockfighting in folks and customs areas. Also the items for designating commemoration days were the Suelbeam and Suelbeam Socks present for the aged people, man cooking day, Korean traditional workers day in folk and ceremony areas.

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Seasonal changes of nitrogen fixation and growth characteristics of kummerowia striata(thunb)schindl. populations (매듭풀 ( Kummerowia striata ( Thunb. ) Schindl. ) 개체군의 질소고정활성과 생육특성의 계절변화)

  • Song, Seung-Dal;Bae, Sang-Mee
    • The Korean Journal of Ecology
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    • v.15 no.4
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    • pp.377-386
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    • 1992
  • Seasonal changes of symbiotic nitrogen-fixation activity and growth characteristics of four different natural populations of kummerowia striata were quantitatively analyzed during the growing period. the nitrogen-fixation activity of root nodules attained the maximum rates of 148, 132, 102 and 100$\muM\;C_2H_4\;\cdot\;g\;fw\;nodule^{-1}\;\cdot\;hr^{-1}$, respectively for sunny, multibranched, shade and unibranched populations at the optimum growth conditions. and the seasonal changes showed fluctuations by environmental conditions such as light, temperature, nutrient contents, water stress and plant ages, etc. The multibranched plant showed the greater amount of leaf and root nodule biomass, and the higher nitrogenase activity than the unibranched plant. the optimum conditions of leaf chloropht11 and water content of each organ indicated the active growth and the maximum fresh biomass of 4 different populations were 1.92, 1.85, 0.97 and 0.56 g $fw\cdotplant^{-1}$ for shade multibranched, sunny and unibranched populations, respectively.

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A Study on the Characteristics of Rural and Urban Surface Ozone Conentrations (청정지역과 도시지역의 오존농도 특성 연구)

  • 서명석;박경윤;이호근;장광미;강창희;허철구;김영준
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.3
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    • pp.253-262
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    • 1995
  • A study has been performed on the characteristics of rural and urban surface ozone concentration for the period of March 1992 to February 1993. The monitoring station of rural ozone is located at Kosan, Cheju and other urban monitoring stations are located at Seoul, Pusan and Kwangju. Rural's and urban's ozone data exhibit a distinct features in many ways. First, annual mean of rural ozone concentration os very high(42 ppbv) but urban's are very low(10 .sim.15 ppbv). Second, rural ozone data shows a seasonal variation with it's maximum in spring, and minimum in summer, but urban's show a seasonal variation with it's maximum in spring, and minimum in winter. Third, diurnal variation of rural data is very small but that of urban's are very large. Fourth, urban's data are extremely low(< 3 ppbv) and have no seasonal variations.

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Seasonal Variations of Monoterpene Concentrations in a Pine Forest in Florida, USA

  • Kim, Ki-Hyun;Kim, Jo-Chunn
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.E3
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    • pp.175-180
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    • 2002
  • In order to study the distribution characteristics of natural volatile organic compounds (NVOCs), we investigated the seasonal variations of $\alpha$-and $\beta$-pinene levels in a pine forest in Florida for a you. The mean concentrations of $\alpha$- and $\beta$-pinene measured during the whole study period were computed to be 125: 86 (N = 65) and 86$\pm$52 pptv (N = 56), respectively. According to our data grouping scheme, the seasonal means for both pinones were observed to peak during fall with their max and min values in summer and winter, respectively. The overall results of our study suggest that terpenes are subject to highly strong temporal variability because of changes in their major source characteristics across seasons.

Experimental research on dynamic characteristics of frozen clay considering seasonal variation

  • Xuyang Bian;Guoxin Wang;Yuandong Li
    • Geomechanics and Engineering
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    • v.36 no.4
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    • pp.391-406
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    • 2024
  • In order to study the soil seasonal dynamic characteristics in the regions with four distinct seasons, the soil dynamic triaxial experiments were conducted by considering the environmental temperature range from -30℃ to 30℃. The results demonstrate that the dynamic soil properties in four seasons can change greatly. Firstly, the dynamic triaxial experiments were performed to obtain the dynamic stress-strain curve, elastic modulus, and damping ratio of soil, under different confining pressures and temperatures. Then, the experiments also obtain the dynamic cohesion and internal friction angle of the clay under the initial strain, and the changing rule was summarized. Finally, the results show that the dynamic elastic modulus and dynamic cohesion will increase significantly when the clay is frozen; as the temperature continues to decrease, this increasing trend will gradually slow down, and the dynamic damping ratio will go down when the freezing temperature decreases. In this paper, the change mechanism is objectively analyzed, which verifies the reliability of the conclusions obtained from the experiment.

A Study on Seasonal Nitrogen Treatment Characteristics according to Design of Constructed Wetland (인공습지의 형태에 따른 계절별 질소처리 특성 연구)

  • Son, Yeong-Kwon;Yoon, Chun-Gyeong;Kim, Jun-Sik;Kim, Hyung-Joong
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.94-101
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    • 2012
  • The performance data for eight years from a free-surface-flow constructed wetland system receiving agricultural tailwater were used to analyze denitrification rate and nitrogen treatment characteristics according to season and wetland design. Seasonal difference between growing season (March~November) and winter season (December~February) was shown in the concentration of all nitrogen species. Seasonal nitrogen treatment has similar trend with temperature and measured denitrification rate. The highest denitrification rate was measured in July, but treatment efficiency was most higher in May and June. Nitrogen absorption of vegetation could affect to these wetland performances, therefore dense population of wetland vegetation might be helpful. According to design of wetland, at least 25~50 m of wetland length was needed to decrease effluent T-N concentration to background concentration in growing season. In winter season, wetland needed much longer distance to reduce T-N concentration. Mass removal rate was continuously high through whole year because runoff coefficient was low in winter season. Applicability of constructed wetland was observed for the total maximum daily load that control T-N load.