• Title/Summary/Keyword: GROWTH DENSITY

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Effect of Growth Environment on the Root Development of Pasture Species II. Root distribution under contrasting fold situations (생육환경이 주요 목초의 뿌리발육에 미치는 영향 II. 생육환경에 따른 뿌리 분포)

  • Hur, S.N.;David Scott
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.23 no.2
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    • pp.91-94
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    • 2003
  • Rhizotron technique was used to determine the zone of active root growth in contrasting field situations. The distribution of roots with depth showed most root in the 15∼30 cm layer with fewer in the 0∼15 cm and below 30 cm layer at Lincoln Farm, while root density increased with depth at Winchmore. At Mt Johm (Lake Tekapo) roots were more distributed near soil surface. Root density was increased with fertilizer and irrigation at Mt John. Root number showed the same trends as root length at all lesions. Tube method was good for comparative purposes, and for long-term root growth studies at the same place.

An Environmental Effect on Productivity of Flounder Culture Farms (넙치양식장 환경에 따른 생산성에 관한 연구)

  • Eh, Youn-Yang
    • The Journal of Fisheries Business Administration
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    • v.42 no.3
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    • pp.79-93
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    • 2011
  • Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

Arthropod Community in the Rice Fields with Different Irrigating Water Quality in Banwol, Kyonggi-do (경기도 반월지역에서의 농업용수 수질에 따른 수도포장내 절지동물군집)

  • 박홍현;이준호;배윤환
    • The Korean Journal of Ecology
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    • v.20 no.5
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    • pp.375-384
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    • 1997
  • The effects of three different irrigating water qualities(clean water, life sewage and animal sewage) on the pattern of arthropod communities in the rice fields were investigated at Banwol, Kyonggi-do, mid-western part of Korea from 1994 to 1996. The total density of arthropod was highest in the rice field which was irrigated with clean water(clean water field), and the arthropod community was mainly composed of aphids and collembolans. Each functional group was found in the order of 'pests>non-pests>natural enemies' in its density. The dominant taxa in the pest group were aphids, planthoppers(Delphacidae), leafhoppers(Cicadelidae) and rice water weevil(L. oryzophilus). In the non-pest group collembolans, non-biting midges and dipterans were main arthropods, and in the natural enemy group Araneae was the dominant taxon. In the early growth stage of rice plant the dominant functional group was pests, and in the mid growth stage both the pest and the natural enemy group became dominant. But in the late growth stage none of the functional group was dominant over the other functional groups. The densities of spiders were much more higher in the clean water field than in the other fields. And through all the growth stages of rice plants the density of spiders in clean water field kept increase in contrast to the others. The species composition of spiders in the life sewage field was similar to that in the animal sewage field, but in the clean water field it was different from the other two fields.

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The formation of diamond films on high speed steel with a titanium inter- layer by electron-assisted CVD process (화학증착법에 의한 티타늄 피복된 고속도강에의 다이아몬드 박막 형성)

  • 정연진;이건영;이호진;최진일
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.1
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    • pp.6-11
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    • 2004
  • The characteristics of interface layer and the effect of bias voltages on the nucleation density and heteroepitaxial growth of diamond films were studied in the hot filament CVD diamond process. Diamond films were deposited on a high speed steel (SKH-51) substrate by bias-assisted hot filament CVD technique with a titanium interlayer. The bias applied for enhancing the emission of electrons from the filament increased the nucleation density and achieving heteroepitaxial growth of CVD diamond. Diamond films obtained at a gas pressure of 20 torr; a bias voltage of 200 V and a substrate temperature of $700^{\circ}C$. Titanium was a suitable element as an interlayer for the diamond deposition on steel because it has high diffusivity of Fe and C as a carbide forming element.

Sediment Properties and Growth of Phragmites australis in Mud Tidal Flat (조간대 저토 환경과 갈대의 생장 특성)

  • Min, Byeong Mee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.3
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    • pp.57-69
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    • 2011
  • This study examined the relationship between Phragmites australis' growth and sediment properties at mud tidal flat of Donggum-ri, Gilsang-myeon, Gangwha-gun, Incheon city. Field survey was carried out from May, 2010 to October, 2010. Water content, soil texture, electric conductivity and water table depth for sediment, density, height, dry weight and flowering for P. australis were examined at several plots from the starting point (the coastal embankment) to the end point of the two populations. The result was as follows. Firstly, the water table increased along distance from the embankment at one line (N-line) but was similar at the other line (S-line) in a P. asustralis population. Water tables were higher out of than within a P. australis population at two populations. Secondary, in N-line, the height and dry weight of P. australis decreased along the distance from embankment but, in S-line, those were similar in its population. P. australis' growth was dependent on electric conductivity at lower layer (water table level) rather than upper one (the surface). Thirdly, density of P. australis changed during growing season and was similar in a population, except for the end point of patch. In summary, the growth and distribution of P. australis were dependent on salt content of tidal flat's sediment (water table level) and this was affected by fresh water of the inland.

Size and Density of Graphene Domains Grown with Different Annealing Times

  • Jung, Da Hee;Kang, Cheong;Nam, Ji Eun;Kim, Jin-Seok;Lee, Jin Seok
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3312-3316
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    • 2013
  • Single crystals of hexagonal graphenes were successfully grown on Cu foils using the atmospheric pressure chemical vapor deposition (CVD) method. We investigated the effects of reaction parameters, such as the growth temperature and annealing time, on the size, coverage, and density of graphene domains grown over Cu foil. The mean size of the graphene domains increased significantly with increases in both the growth temperature and annealing time, and similar phenomena were observed in graphene domains grown by low pressure CVD over Cu foil. From the comparison of micro Raman spectroscopy in the graphene films grown with different annealing times, we found that the nucleation and growth of the domains were strongly dependent on the annealing time and growth temperature. Therefore, we confirmed that when reaction time was same, the number of layers and the degree of defects in the synthesized graphene films both decreased as the annealing time increased.

Cultivation of the Hyperthermophilic Archaeon Sulfolobus solfataricus in Low-Salt Media

  • Park, Chan-Beum;Lee, Sun-Bok
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.4 no.1
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    • pp.21-25
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    • 1999
  • Two low-salt complex media, bactopeptone and desalted yeast extract, were used for high density cultivation of the hyperthermophilic archaeon Sulfolobus solfataricus (DSM 1617). Bactopeptone, which has low mineral ion content among various complex media, was good for cell growth in batch cultures; the maximal cell density in bactopeptone was comparable to that in yeast extract. However, cell growth was rather poor when bactopeptone was added by the fed-batch procedure. Since several vitamins are deficient in abctopeptone, the effect of vitamins on cell growth was examined. Among the vitamins tested, pyridoxine was found to improve the growth rate of S. solfataricus. To reduce the growth inhibition caused by mineral ions, yeast extract was dialyzed against distilled water and then fed-batch cultures were carried out using a fed medium containing desalted yeast extract. Although the concentrations of mineral ions in yeast extract were significantly lowered by the dialysis whether low molecular weight solutes in yest extract are crucial for cell growth, we investigated the effect of trehalose, a most abundant compatible solute in yeast extract, on the growth pattern. Cell densities were increased and the length of the lag phase was markedly shortened by the presence of trehalose, indicating that trehalose plays an important role in the growth of S. solfataricus.

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Culture of Endothelial Cells by Transfection with Plasmid Harboring Vascular Endothelial Growth Factor

  • Chang, Sungjaae;Sohn, Insook;Park, Inchul;Sohn, Youngsook;Hong, Seokil;Choe, Teaboo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.2
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    • pp.106-109
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    • 2000
  • Vascular endothelial cells (EGs) are usually difficult to culture to culture in a large scale because of their complicated requirements for cell growth. As the vascular endothelial growth factor (VEGF) is a key growth factor in the EC culture, we transfected human umbilical vein endothelial cells (HUVEC) using a plasmid containing VEGF gene and let them grow in a culture medium eliminated an important supplement, endothelail cell growth supplement(ECGS). The expression of VEGF by HUVEC tansfected with Vegf GENE was not enough to stimulate the growth of HUVEC, only 40% of maximum cell density obtainable in the presence of ECGS. However, when the culture medium was supplied with 2.5 ng/ml of basic fibroblast growth factor (bFGF), a synergistic effect effect of VEGE and bFGF was observed. In this case, the final cell density was recovered was recovered up to about 78% of maxium value.

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Effects of Light Intensity and Quality on the Growth and Quality of Korean Ginseng (Panax ginseng C.A. Meyer) II. Relationship between Light Intensity and Planting Density (광량 및 광질이 고려인삼의 생육과 품질에 미치는 영향 II. 광량과 재식밀도와의 관계)

  • Cheon, Seong-Gi;Mok, Seong-Gyun;Lee, Seong-Sik
    • Journal of Ginseng Research
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    • v.15 no.1
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    • pp.31-35
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    • 1991
  • In order to know the optimum planting density under shading structures at different light intensity, We investigated the growth status, distribution of ginseng leaf area, correlation between planting density and root weight per plant and yield, correlation between leaf area index and root weight per plant and yield. According to the increase of planting density the leaf area per plant was decreased, but leaf area index (L.A.I) was increased. Ginseng leaf population at different lines under common straw shading were distributed mainly in frost lines but polyethylene net shading at 10fo light intensity were distributed equally in all lines. Optimum planting density in common straw shading at 5% light intensity was 55 plant per tan (90 cmX180 cm) and polyethylene net shading 81 10% light intensity was 60 plant per tan, in consideration of root weight and yield. Optimum leaf area index was 2.4 under common straw shading at 5% light intensity but was 2.7 under polyethylene net shading at 10% light intensity.

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Water Temperature, Rearing Density and Feeding Rate on Growth and Survival Rate of Red Marbled Rockfish, Sebastiscus tertius Larvae (수온, 자어밀도 및 먹이공급량에 따른 붉은쏨뱅이, Sebastiscus tertius 자어의 성장과 생존율)

  • 허성범;임상구;김철원;김광수
    • Journal of Aquaculture
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    • v.12 no.3
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    • pp.213-220
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    • 1999
  • This study was performed to investigate the effects of water temperature and stocking density and rotifer density on the mass production of larval red marbled rockfish, Sebastiscus tertius. Total length of the marbled rockfish larva grown in $23^{\circ}C$ of water temperature were 10.80mm, which was the best, while those grown in $29^{\circ}C$ of water temperature were 6.28mm, which was the lowest. The survival rates of red marbled rockfish larvae grown in $20^{\circ}C$ and $23^{\circ}C$ were 24.0% and 18.5%, respectively. However, the survival rate of red marbled rockfish larvae grown in $26^{\circ}C$ was $7^{\circ}C$ and no larvae survived in $29^{\circ}C$. The total length of red marvled rockfish larva stocked at the density of 5 and 10 larvaper liter of water were high, which were 11.52 mm and 11.22 mm, respectively, but those stocked at the density of 30 larva per liter of water were 7.55mm, which was the lowest. The survival rate of red marbled rockfish larva stocked at the density of 2.5 larva per liter of water was 52.0%, which was the best, but the lowest, 18.0% for the red marbled rockfish larva stocked at the density of 30 larva per liter. There was a trend toward decrease in survival rate of red marbled rockfish larva as their stocking density increased. The survival rates of red marbled rockfish larva fed rotifers at the density of 10 and 5 individuals per ml were high, 48.5% and 48.0%, and their total lengths were 11.92 and 11.89mm, respectively, which grew relatively fast. The survival rate and the total length of red marbled rockfish larva fed rotifers at the density of 30 individuals per ml were the lowest, which were 8.40mm and 21.5%, respectively. Also, red marbled rockfish larva fed rotifers at the density of more than 20 individuals per ml achieved poor survival and growth. These results indicated that the proper conditions for the mass production of larval red marbled rockfish were $23^{\circ}C$ of water temperature, fish larva stocking density of 5 to 10 larva per liter of water and rotifers density of 5 to 10 individuals per ml as live feed.

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