• Title/Summary/Keyword: Vertical distribution pattern

Search Result 236, Processing Time 0.025 seconds

The Vertical Distribution Patterns of Long Range Transported SO2 in Korea Peninsula (한반도 서해상으로 장거리 이동하는 SO2의 농도 및 연직분포 특징)

  • Han, J.S.;Ahn, J.Y.;Hong, Y.D.;Kong, B.J.;Lee, S.J.;Sunwoo, Y.
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.20 no.5
    • /
    • pp.671-683
    • /
    • 2004
  • This study was carried out to understand long-range transport of $SO_2$ using aircraft measurements for the identification of it's horizontal and vertical concentration and distribution pattern. Thirteen missions of aircraft measurements have been done around 37$^{\circ}$00'/124$^{\circ}$30' from October 1997 to November 2001. Concentrations of $SO_2$ was 1.5~2.0 ppb in the below mixing layer, 0.6~1.1 ppb in the above mixing layer. $SO_2$ was found to be relatively higher than marine background level, 0.08~0.2ppb, indicating the western coast being influenced by long-range transport except for the summer season. The vertical distribution of $SO_2$ was classified into 3 groups using its vertical sounding and meteorology pattern; the first is linear decay pattern, the second is exponential decay pattern, and the last is gaussian distribution pattern in the below mixing layer, 2 patterns of linear decay and gaussian distribution patterns in the upper layer. It is founded that vertical distribution pattern is strongly dependent on meteorological condition, for example atmospheric stability and predominant air flow.

Diel Vertical Distribution of Phytoflagellates in a Small Artificial Pond

  • Kim, Han-Soon;Takamura, Noriko
    • ALGAE
    • /
    • v.17 no.1
    • /
    • pp.1-9
    • /
    • 2002
  • Diel vertical distribution of phytoflagellates and interactions between the phytoplankton components and environmental and biological factors were studied in a small artificial pond for three days on the December 18, 1998 and April 9 to 10, 1999. The phytoplankton population was dominated by Mallomonas akrokomos of chrysophytes and Cryptomonas marssonii and Chroomonas sp. of cryptophytes. The vertical distribution of these phytoflagellates taxa exhibited clear diel migration pattern. Moreover their migration patterns are showed differential fluctuation between M. akrokomos, C. marssonii and Chroomonas sp. The later two species upward migrated in the evening as well as night, whereas the former species migrated downward. Their distinctive migration pattern was found during the night but was not observed in the morning. During daytime C. marssonii and Chroomonas sp. showed maximum density above 2 m depth but M. akrokomos below 2 m depth. The diel vertical distribution of the dominant phytoflagellates did not show significant correlation between physical, chemical and biotic factors.

Vertical Distribution of Phytoplankton in the Paldang Dam Reservior (팔당댐 담수수역 식물플랑크톤의 수직분포)

  • Lee, Kyung
    • Journal of Plant Biology
    • /
    • v.29 no.2
    • /
    • pp.117-127
    • /
    • 1986
  • Phytoplankton community was investigated at the Paldang Dam Reservoir in the Mid-Han River by it's depth, in spring and summer known as the period of phytoplankton's blooming. It was only in summer that phytoplankton bloomed at the investigated area. 128 kinds of phytoplankton were identified and of them, diatoms were abundunt in spring but cyanophyta and chlorophyta were in summer. Because some species with high pollution index were observed in summer, it could be proved that the investigated area was polluted especially in summer. In spring shown the circulation period by vertical distribution pattern of chlorophyll-a and isothermal distribution pattern of water temperature, maximum value of phytoplankton standing crops appeared at the upper layer, except for surface layer. In summer shown the circulation period after the stagnation period by vertical distribution pattern of chlorophyll-a and immediate destruction after stratification of water temperature, maximum value of phytoplankton standing crops appeared at the lower layer. the layer at which the maximum value of chlorophyll-a appeared also accorded with that of phytoplankton standing crops. So, it could be approved that there existed a close relationship among phytoplankton standing crops, chlorophyll-a, and water temperature.

  • PDF

Analysis of Productivity in Rice Plant - (III) Dynamic Change of Canopy Structure - (벼의 생산력 분석 - (III) 군락구조의 동적변화 -)

  • Park, Hoon;Park, Young-Sun
    • Applied Biological Chemistry
    • /
    • v.15 no.1
    • /
    • pp.41-47
    • /
    • 1972
  • Comparative study on dynamic change of canopy structure during ripening period were carried out by using newly bred high yield rice cultivar (IR 667-Suwon 213) and a commercial variety, Jinhung in relation to nitrogen nutrition. The results were as follows. 1. Canopy structure pattern (vertical distribution of dry matter density at heading)was vertical type for Jinhung and horizontal type for IR 667. 2. The vertical distribution pattern of leaf area density (or weight) in the canopy was central dominant type for IR 667 while apical dominant type for Jinhung. 3. Canopy conservation pattern and percent distribution pattern of leaf area density followed the vertical distribution pattern of leaf area density. 4. Canopy persistence was weaker in IR 667, thus they have smaller canopy conservation ratio indicating faster senescence. 5. Slow supply of nitrogen (sulfur coated urea) showed a trend to change the apical dominant pattern into the central dominant pattern by the conservation of central portion, and it-resulted in higher yield though nitrogen nutrition did little affect canopy pattern. 6. The central and apical dominant pattern appeared to be well matched to the upper leaf-dependent type and the lower leaf-dependent type of grain yield, respectively.

  • PDF

Stress Analysis on the Supporting Bone around the Implant According to the Vertical Bone Level (치조골 높이가 다른 임프란트 주위 지지골 응력분석)

  • Boo, Soo-Boong;Jeung, Jei-Ok;Lee, Seung-Hoon;Kim, Chang-Hyun;Lee, Seung-Ho
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.23 no.1
    • /
    • pp.55-68
    • /
    • 2007
  • The purpose of this study was to analyze the distribution of stress in the surrounding bone around implant placed in the first and second molar region. Two different three-dimensional finite element model were designed according to vertical bone level around fixture ($4.0mm{\times}11.5mm$) on the second molar region. A mandibular segment containing two implant-abutments and a two-unit bridge system was molded as a cancellous core surrounded by a 2mm cortical layer. The mesial and distal section planes of the model were not covered by cortical bone and were constrained in all directions at the nodes. Two vertical loads and oblique loads of 200 N were applied at the center of occlusal surface (load A) or at a position of 2mm apart buccally from the center (load B). Von-Mises stresses were analyzed in the supporting bone. The results were as follows; 1. With the vertical load at the center of occlusal surface, the stress pattern on the cortical and cancellous bones around the implant on model 1 and 2 was changed, while the stress pattern on the cancellous bone with oblique load was not. 2. With the vertical load at the center of occlusal surface, the maximum von-Mises stress appeared in the outer distal side of the cortical bone on Model 1 and 2, while the maximum von-Mises stress appeared in the distal and lingual distal side of the cortical bone with oblique load. 3. With the vertical load at a position of 2 mm apart buccally from the center, there was the distribution of stress on the upper portion of the implant-bone interface and the cortical bone except for the cancellous bone, while there was a distribution of stress on the cancellous bones at the apical and lingual sides around the fixture and on the cortical bone with oblique load. 4. With the changes of the supporting bone on the second molar area, the stress pattern on the upper part of the cortical bone between two implants was changed, while the stress pattern on the cancellous bone was not. The results of this study suggest that establishing the optimum occlusal contact considering the direction and position of the load from the standpoint of stress distribution of surrounding bone will be clinically useful.

Community Dynamics of Benthic Marine Algae in the Intertidal and Subtidal Rocky Shore of Samyang, Jejudo Island

  • Yoo,Jong-Su
    • ALGAE
    • /
    • v.18 no.4
    • /
    • pp.301-309
    • /
    • 2003
  • Community structure and vertical distribution of benthic marine algae were investigated in the intertidal and subtidal rocky shore of Samyang, Jejudo Island. The total number of 62 algal species composed of 6 Cyanophyta, 6 Chlorophyta, 19 Phaeophyta, and 31 Rhodophyta were observed. The dominant species were melobesioidean algae, Sargassum thunbergii, Hizikia fusiformis, and Ulva pertusa in the intertidal zone and melobesioidean algae, Ulva pertusa, Corallina spp., and Undaria pinnatifida in the subtidal zone. The vertical algal distribution was represented by the melobesioidean algae in the whole rocky shore, Caulacanthus ustulatus in the upper intertidal zone, Sargassum thunbergii and Hizikia fusiformis in the middle and lower zone, Ulva pertusa in the lower zone and Ulva pertusa, Corallina spp., and Undaria prinnatifida in the subtidal zone. The composition of dominant species and pattern of the vertical distribution of algae in the present study were significantly different from the previous reports. Especially, distribution of crustose coralline algae was significantly extended.

Effects of Annular Gap Size on the Flow Pattern and Void Distribution in a Vertical Upward Two-Phase Flow (수직상향 이상류에서 동심원관 간극이 유동양식과 보이드분포에 미치는 영향)

  • Son B. J.;Kim I. S.;Kim M. C.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.16 no.4
    • /
    • pp.383-391
    • /
    • 1987
  • An experimental investigation has been conducted to determine the flow pattern for two-component , two-phase mixtures which flow vertically upwards in concentric annuli based on the measurement for the local void fraction and the distribution of the local void fraction in various radial locations in the annular gap. The annular test section consists of a lucite outer tube whose inside diameter is 38mm and a stainless steel rod, The rod diameter is either :2mm,16mm or 20mm. It is demonstrated that the probability density function of the fluctuations in void fraction may be used as an flow pattern indicator and the local void fraction distribution depends on the flow pattern and radial location in the annular passage.

  • PDF

Fluctuation Characteristics of Radial Void Fraction in Vertical Concentric Annuli (수직동심환상관에서 반경방향 보이드율의 변동특성)

  • Son B.J.;Kim I.S.;Kim M.C.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.16 no.5
    • /
    • pp.516-524
    • /
    • 1987
  • This paper presents experimental data of fluctuation characteristics of local void fraction of air-water two-phase flow which are associated with the flow pattern, annular gap size and radial location in vertical concentric annuli with coefficient of skewness and kurtosis. The annular gap widths are 13mm, 11mm, and 9mm for a 38m inner diameter as the lucite outer tube. A electrical conductivity probe was used to measure the local void fraction and traversed diametrically from inner wall to outer wall using radial increments of 2mm. It was shown that distribution of the coefficient of skewness and kurtosis, which is related that the one is the asymmetry and the other peakness of local void fraction distribution was influenced by flow pattern, annular gap size and radial location.

  • PDF

Day-Night Vertical Distribution of Euphausiids in the Northern East Sea in Winter (겨울철 동해 북부 난바다곤쟁이류(Euphausiids)의 주야 수층별 분포)

  • Bo-Ram Lee;Hyun-gyu Lee;Hwan-Sung Ji
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.56 no.2
    • /
    • pp.259-264
    • /
    • 2023
  • Day-night vertical euphausiid distribution was investigated at three stations in the East Sea using a Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS). Three euphausiid species were recognized. Euphausia pacifica was more dominant than Thysanoessa longipes. Euphausiids were collected at Station 1 at night, Station 2 at sunset, and Station 3 during the daytime. At Station 1, calyptopis and furcilia stages were concentrated from the surface to 30 m and 20-40 m, respectively. Juveniles and E. pacifica were distributed in strata shallower than 30 m. At Station 2, calyptopis and furcilia stages were dominant in strata from the surface to 40 m. Juveniles were not recorded in strata at 30-100 m. However, E. pacifica occurred in these strata. At Station 3, calyptopis and furcilia stages occurred in the upper 40 m of strata. E. pacifica was distributed deeper than 100 m and rarely occurred above 100 m. The furcilia stages weakly migrated, whereas the calyptopis stages did not. Juveniles and E. pacifica showed a clear migration pattern. Vertical distribution of euphausiids in the northern East Sea varied by life stage and time of day.

Study of Stokes Flow Past a Vertical Plate in a Two-Dimensional Channel (2차원 채널 내의 수직 평판을 지나는 스톡스 유동에 대한 연구)

  • Yoon, Seok-Hyun;Jeong, Jae-Tack
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.35 no.6
    • /
    • pp.609-615
    • /
    • 2011
  • A two-dimensional Stokes flow past a vertical plate in a channel is analyzed. The vertical plate is located at the center of the channel, and plane Poiseuille flow exists far upstream and downstream of the vertical plate. The Stokes approximation is used, and the flow is investigated analytically using the method of eigenfunction expansion and the point collocation method. From the analysis, the stream function and pressure distribution are obtained, and the pressure and shear stress distributions on the plate and channel wall are calculated. The additional pressure drop induced by the vertical plate and the force exerted on it are calculated as functions of the length of the vertical plate. For a typical length of the vertical plate, the streamline pattern and pressure distribution are shown. In addition, numerical analysis of laminar flow with a small Reynolds number is carried out to analyze the effect of a small Reynolds number on the flow pattern.