• Title/Summary/Keyword: mesoscale

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Recent SAXS Progress at NSRRC

  • Jeng U.;Hsu C.-H.;Sun Y.-S.;Lai Y.-H.;Chung W.-T.;Sheu H.-S.;Lee H.-Y.;Song Y.-F.;Liang K. S.;Lin T.-L.
    • Macromolecular Research
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    • v.13 no.6
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    • pp.506-513
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    • 2005
  • We review the recent SAXS activity on the 1.5-GeV electron storage ring at the National Synchrotron Radiation Research Center (NSRRC). Typical measurements featuring in grazing incident SAXS for soft materials are illustrated. Complex measurements using simultaneous SAXS/DSC and SAXSIWAXS for the correlations between the crystallization and mesoscale ordering in a polymer blend and a polypeptide-block-polypseudorotaxane diblock copolymer are presented. We also introduce a dedicated SAXS beamline which is planned at NSRRC.

The numerical study on relationship between mesoscale circulation and deposition of air pollutant (1) - particle dry deposition according to diameter - (중규모 순환과 입자오염물질의 침적에 관한 수치연구(1) - 입자상 물질의 입경별 침적양 추정 -)

  • 이화운;이순환;반수진
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.399-400
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    • 2002
  • 오염물질의 지표농도 결정에 있어 침적과정은 아주 중요하다. 이전의 연구들에서 가스상 물질 중 특히 SO$_2$의 경우 대기중으로부터 건성침적 과정에 의해서 제거되는 양이 대기로의 총 방출량의 약 1/3배정도 됨을 나타내었다(Arritt et al. 1988; Hicks et al., 1991). 입자상 물질의 침적 역시 오염물질의 장거리 수송의 중요한 부분을 차지하고 있다. 특히 황사기간중의 침적과정은 물질의 국가간이동으로 매우 중요시되면서, 건성침적량 및 영향에 대한 연구가 수행되어져 왔다(Kim et al.,1991). (중략)

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동해 연안에서 발생하는 중규모 와동류의 분포와 시간적인 변동에 관한 연구

  • 김순영;김동주;이형선;이재철
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 1999.10a
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    • pp.88-91
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    • 1999
  • Temperature data observed by NERDA and the satellite infrared imagery off the east coast of Korea from 1994 to 1998 for 5 years were analyzed to study the distribution, temporal change, and structure of mesoscale eddies appearing almost permanently off the east coast of Korea. Typically, the eddy distribution can be characterized by two cases; two-eddy case and three-eddy case. In 1995 and 1996, there were only two eddies, one northeast of Sokcho and the other around the Ulleung Island. In 1994, 1997 and 1998, three eddies were located off Wonsan, Sokcho and Youngduk. For two-eddy case, the Ulleung Eddy surrounded the Ulleung Island, whereas this eddy is located south of the island in three-eddy case.

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A change of local meteorological environment according to dam construction of Nakdong-River -II. Estimation using numerical model- (낙동강 수계 중의 댐 건설에 의한 주변의 국지기상환경 변화 -II. 수치모델을 이용한 추정-)

  • 전병일;이영미
    • Journal of Environmental Science International
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    • v.11 no.4
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    • pp.281-288
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    • 2002
  • This study was carried out for reading the change of local meteorological environment according to dam construction of Nakdong-river using numerical model. The study used PSU/NCAR Mesoscale Model version5(MM5) for inquiring effect of formation of artificial lake after dam construction. The colleague simulated temperature mixing ratio, latent heat flux and sensible heat flux in two cause of existing lake and not. Temperature and mixing ratio in southwest of Andong lake increased because of the air that was warm and moist above the lake moved to southwest due to the northeasterly wind. In the case of existing lake around Andong, latent heat flux increased much in the daytime after sunrise. However, sensible heat flux decreased but it didn't change distinctly in southwest of Andong like the other values.

The simulation of the land and sea breeze over Pusan District (부산지방 해륙풍에 관한 Simulation)

  • Jang, Kwang-Mee;Moon, Sung-Euii;Jo, Byeong-Gil
    • Journal of Environmental Science International
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    • v.2 no.1
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    • pp.9.1-16
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    • 1993
  • Land-sea breeze over Pusan district is investigated by performing the numerical simplations with orography on a two-dimensional mesoscale model. The model results show that the sea breeze strengthens and begins to move inland at 1000LST. The strongest sea breeze is occurred at 1500LST and begins to weak at 1700 LST. After 2400LST a weaker land breeze compared with the sea breeze develops. The observed datas and the simulated land-sea breeze is not coinsidented exactly at the event day(1983. 9. 19.) . But simulated land-sea breeze is corresponded of synoptic characteris- tics that was studied previously.

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A Three Dimensional Numerical Simulation of the Land and Sea breeze over Pusan Coastal Area, Korea. (부산 연안에서의 3차원 해륙풍 수치 모의)

  • 문승의;김유근
    • Journal of Environmental Science International
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    • v.2 no.2
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    • pp.103-113
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    • 1993
  • The land and sea breeze over the Pusan coastal area is studied by three dimensional mesoscale numerical model. According to the results of the simulation experiments, both Pusan areas and Kimhae areas, the sea breeze began at 0800LST and the strongest at 1500LST and then at 1800LST. After midnight, the sea breeze changed about the land breeze and become weaker than that of the sea breeze in the daytime. Comparisons between calculations and observations showed that the characteristics of diurnal variation and v-component of the wind velocity relatively is similar to the Pusan areas. On the Kimhae areas, however, observations showed time lag which compared to the results of simulation experiments in the velocity of sea breeze and diurnal variation. From the above results, comparisons between calculations and observations is much more similar to the coastal areas than on the inland area.

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A Numerical Simulation of Horizontal Convection in Mesoscale (중규모에서의 수평대류에 관한 수치모의)

  • 정우식;이화운
    • Journal of Environmental Science International
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    • v.7 no.2
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    • pp.233-241
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    • 1998
  • This study Is concerned with properties of a thermal convection in a stably stratified Boussinesq fluid caused by partial heating at the lower boundary. For thins purpose, two-dimensional, nonrotating system was employed. U the heating is very strong, convection takes the form of a turbulent plume. Othenuse, remains laminar. If the partial heating at the bottom boundary Is symmetric. the convection takes the form of a trubuient plume. Otherwise remains but beating form Is not so signiacant as to alter the vergence in the lower layer at the center of the partial heating area. The temperature perturbation is characterized by the temperature 'Cross-Over' over the partial heating area. These features are cleared ac- cording to the Increase of temperature difference between the center and side part of the bottom boundary.

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The simulation of the land and sea breeze over Pusan District (부산지방 해륙풍에 관한 Simulation)

  • Jang, Kwang-Mee;Moon, Sung-Euii;Jo, Byeong-Gil
    • Journal of Environmental Science International
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    • v.2 no.1
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    • pp.9-9
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    • 1993
  • Land-sea breeze over Pusan district is investigated by performing the numerical simplations with orography on a two-dimensional mesoscale model. The model results show that the sea breeze strengthens and begins to move inland at 1000LST. The strongest sea breeze is occurred at 1500LST and begins to weak at 1700 LST. After 2400LST a weaker land breeze compared with the sea breeze develops. The observed datas and the simulated land-sea breeze is not coinsidented exactly at the event day(1983. 9. 19.) . But simulated land-sea breeze is corresponded of synoptic characteris- tics that was studied previously.

A Numerical Modeling Study on the Interannual Variability in the Gulf of Alaska (알라스카 만의 경년변화에 대한 수치모형 실험)

  • Bang, In-Kweon;Zygmunt Kowlik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.3
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    • pp.298-308
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    • 1994
  • Ocean circulation in the Northeast Pacific Ocean is simulated using a high-resolution primitive equation numerical model with realistic bottom topography. The goal is to explain better the details of observed interannual variability of the circulation in the Gulf of Alaska. Our numerical model suggests that there is no seasonal shift in the Alaska gyre and that the interannual variability. reported earlier, is most likely the result of embedded mesoscale eddies in the dynamic topography. Such eddies have been observed in hydrographic. satellite-tracked drifters and altimeter data from the Gulf of Alaska.

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Discussion of the edge flame structure at the near flammability limits (가연한계 영역에서의 에지 화염 구조 및 고찰)

  • Lee, Min Jung;Jung, Yongjin;Kim, Nam Il
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.245-246
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    • 2015
  • In this study, the structure of a edge flame near the flammability limits was explored through several paths approaching the combustion limits of a non-premixed flame: i.e., increase of fuel dilution ratio (FDR), reduction of mean flow velocity and variation of gravity effect. As a result, a unique interesting flame structure was discovered; i.e., a diffusion flame branch was enclosed by two asymmetric premixed flame branches. These structures have been compared for various fuels. Conclusively, each fuel has different flame structure and the meaning of this structure was discussed concerned about our understanding of laminar flame structures.

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