• Title/Summary/Keyword: 탄소입자

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Annual Change and C:N:P ratio in Particulate Organic Matter in Chinhae Bay, Korea (한국진해만 입자유기물 함량과 C:N:P 비의 연변화)

  • LEE, PIL-YONG;KANG, CHANG-KEUN;PARK, JONG-SOO;PARK, JOO-SUCK
    • 한국해양학회지
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    • v.29 no.2
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    • pp.107-118
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    • 1994
  • An investigation of the annual change and C:N:P ratio in particulate organic matter (POM) in Chinhae Bay, a semi-enclosed bay of the southern coast of Korean Peninsula, was carried out for a period of 12 months between January and December, 1993. The concentrations of POM have a broad range: 198∼4,416 ugC/l, 24∼792 ugN/l and 4.5∼69.0 ugP/l, Marked seasonal changes of POM, particularly particulate organic carbon (POC) and nitrogen (PON), were observed in the surface water. Generally, the concentration of POM peaks in summer. The C:N:P composition ratio of particulate organic matter, which is high in summer, also shows a seasonal change. The C:N assimilation ratio is constant at 6.53, which is consistent with the Redfield ratio. The significant linear relationship between POM and chlorophyll-a in the surface water during the survey period (except for January and February) and the C:N ratio suggest that the concentration of POM is controlled by phytoplankton biomass. POM peaks in summer, a period characterized by high freshwater input and the strong stratification, as a result of the intense proliferation of phytoplankton by a large amount of nutrient loading from the tributaries. On the other hand, the high C:P and N:P ratios in summer indicate that P is limited for phytoplankton growth owing to N-enrichment from a high input of freshwater with a high dissolved inorganic N:P ratio.

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A Study on Numerical Perforation Analysis of Axisymmetric Bullet by the Particle Method (입자법을 이용한 축대칭 탄자의 관통거동 수치해석 연구)

  • Kim, Yong-Seok;Kim, Yong-Hwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.6
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    • pp.164-171
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    • 2008
  • A modified generalized particle algorithm, MGPA, was suggested to improve the computational efficiency of standard SPH method in numerical analysis of high speed impact behavior. This method uses a numerical failure mechanism than material failure models to describe the target penetration. MGPA algorithm was more effective to describe the impact phenomena and new boundaries produced during the calculation process were well recognized and treated in the target penetration problem of a bullet. When bullet perforation problems were analyzed by this method, MGPA algorithm calculation gives the stable numerical solution and stress oscillation or particle penetration phenomena were not shown. The error range in ballistic velocity limit is less than $2{\sim}13%$ for various target thickness.

Vertical Distributions of Chemical Oceanographic Parameters in Jinhae Bay in July, 1983 (1983年 7月 鎭海灣의 海洋化學指數의 水質分布에 관하여)

  • Yang, Dong-Beom;Kim, Suk-Hyun;Lee, Kwang Woo
    • 한국해양학회지
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    • v.19 no.1
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    • pp.89-93
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    • 1984
  • Vertical and horizontal distributions of chemical oceanograthic parameters were measured in Jinhae Bay in July, 1983. On the Masan-Gadeog section, high amounts of dissolved nitrates, ammonia, chlorophylla-a, and particulate carbon and nitrogen were observed in waters with low salinity. In the inner Masan Bay, high concentrations of dissolved ammonia and phosphates were shown. The C/N ratio in the surface waters was higer in the outer bay. Concentrations of dissolved inorganic nitrogen and phosphates in the surface waters seemed to be sufficient for red tides to occur.

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Surface characteristics change of natural crystalline graphite powders by adsorption (유기물 흡착에 의한 인상흑연 분체의 표면특성변환 연구)

  • 김병곤;최상근;정헌생;이재장
    • Proceedings of the KSEEG Conference
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    • 2001.04a
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    • pp.308-310
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    • 2001
  • 유기물질이 오랜 기간동안 고온 고압하에서 탄화작용을 받아 생성된 천연흑연은 단위구조가 탄소육각망평면(炭素六角網平面)이 평행하게 배열된 층상으로 전기전도도 및 윤할성이 우수하나 소수성이 매우 강하며 표변화학적 특성이 거의 없기 때문에 다른 물질과 표면흡착이 매우 어려운 물질이다. 따라서 본 연구에서는 흑연의 표면특성을 변화시키고자 유기물(ABDM)을 흡착시키고 표면흡착 매커니즘 및 표면특성을 해석하였다. 흑연 입자 표면 위의 ABDM흡착은 두 단계의 서로 다른 게에서 이루어졌다. 첫 번째 단계는 흡착 초기 흑연입자와 ABDM의 표면전위 특성차이에 의한 1차 흡착으로 흑연표면 소수성이 더욱 증가하는 상태이고, 두 번째 단계는 1차 흡착된 ABDM 과 용액중의 ABDM chain 상호간의 steric 작용에 의한 2차 흡착이었다. 2차 흡착이 완료된 흑연입자 표면은 ABDM 이중층을 형성하게 되고 이에 따라 흑연의 표면전위 특성을 변화시킬 수 있었다.

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