• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.918-925
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• 2008

Controlling the light energy and major nutrients is important for high cell density culture of cyanobacterial cells. The growth phase of Anabaena variabilis can be divided into an exponential growth phase and a deceleration phase. In this study, the cell growth in the deceleration phase showed a linear growth pattern. Both the period of the exponential growth phase and the average cell growth rate in the deceleration phase increased by controlling the light intensity. To control the light intensity, the specific irradiation rate was maintained above $10\;{\mu}mol/s/g$ dry cell by increasing the incident light intensity stepwise. The final cell density increased by controlling the nutrient supply. For the control of the nutrient supply, nitrate, phosphate, and sulfate were intermittently added based on the growth yield, along with the combined control of light intensity and nutrient concentration. Under these control conditions, both final cell concentration and cell productivity increased, to 8.2 g/l and 1.9 g/l/day, respectively.

• Journal of Ginseng Research
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• 제6권1호
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• pp.38-45
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• 1982

To determine the optimum light intensity for growth of ginseng plants, change of temperature, moisture content in son, occurrence alternaria blight, defoliation rate, chlorophyll contents, and growth of shoots and roots were investigated under different light intensity such as 5%, 10%, 20% and 30% light transmittance rare(L.T.R.). The results obtained were as follows. 1. Maximum temperature under the shading was increased as the increase of light intensity, whereas soil moisture content decreased 2. As the increase of light intensity, stem and Peduncle length, leaf area, and chlorophyll contents decreased significantly but length and width of the leaf was not significant, while stem diameter, special leaf weight and chlorophyll a/chl. b ratio increased 3. Stem color was shown dark purp!e as the increase of light intensity. 4. Photosynthesis during the day was highest at 9 A.M. and decreased as time passed in all plots. The means of photouynthesis during the day showed in the order of 20%, 10%, 30%, 5% L.T.R., and optimum light intensity for highest photosxthesis was 18.4% L.T.R. by theoritical equation. 5. It was showed a tendency that alternaria leaf blight of ginseng plants was increased as the increase of light intensity. 6. Defoliation rate of ginseng plants was increased as the increase of light intensity, especially all plants were defoliated by late June without shading. 7. Yield percentage of the rear line was increased as the increase of light intensity. Root weight per plant showed in the order of 20%, 10%, 30%, 5% L.T.R., and optimum light intensity for the best yield was 18.5% L.T.R. by theeritical equation.

• The Korean Journal of Ecology
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• 제20권4호
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• pp.285-291
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• 1997

The taxonomic characteristics of Eupatorium rugosum were reviewed and growth responses under different light intensities were investigated. Changes of soil and vegetation environments at experimental plots on Mt. Namsan were surveyed and the distribution pattern examined. The distribution of E. rugosum was closely related to the content of total nitrogen and available phosphorus in the soil. No competitors which could inhibit the growth of E. rugosum were present. Growth of E. rugosum was highest at a light intensity of 7, 500 lux, but dry weight was highest at a light intensity of 15, 000 lux followed by 30, 000 and 7, 500 lux. Growth in height of E. rugosum under a light intensity of 1, 500 lux continued even though the amount of growth was small. E. rugosum is found throughout the area of Mt. Namsan, and its density is higher at the roadside and in valley regions. E. rugosum appeared at 25 of 50 quadrats on Mt. Namsan, and the mean coverage of E. rugosum in survey quadrats was 12%.

• 디지털융복합연구
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• 제14권10호
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• pp.483-497
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• 2016

본 연구는 8주간의 복합트레이닝 운동 강도가 지적장애 청소년의 렙틴, 성장호르몬, 인슐린유사성장요인-1(IGF-1), 신체조성에 미치는 영향을 비교 분석하기 위한 목적으로 수행되었다. 연구의 대상은 경도 지적장애 청소년 총 26명으로 고강도운동 집단 9명, 중강도 운동 집단 9명, 저강도 운동집단 8명을 선정하였다. 복합 트레이닝 운동강도에 따른 차이를 비교하기 위해 트레이닝 처치 전 사전 값을 공변인으로 하고 각각의 운동 강도를 독립변인으로 하였으며, 렙틴, 성장호르몬, 인슐린유사성장요인-1, 신체조성에 대한 변화를 종속변인으로 하였다. 자료 분석은 공변량 분석을 실시하였으며, 효과크기 ${\eta}^2$(eta)를 산출하였다(p<.05). 분석된 자료를 통하여 얻어진 결론은 다음과 같다. 첫째, 성장기에 있는 지적장애 청소년들에게 동일한 운동량이 주어졌을 때 운동 강도별에 따라 렙틴은 중강도에서 가장 많이 감소하고, 성장호르몬의 증가는 중강도에서 가장 많이 증가하며, IGF-1의 증가는 저강도에서 가장 많이 증가하는 것으로 나타났다. 둘째, 신체조성에 있어 체지방량의 증가는 저강도가 가장 효과적이며, 체지방량의 감소는 중강도에서 가장 효과적이고, 골밀도의 증가는 저강도에서 가장 효과적인 것으로 나타났다. 또한 후속저인 연구에서는 성별, 개인별 운동수행 능력에 따른 구분을 통한 연구가 필요할 것으로 판단된다.

• 원예과학기술지
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• 제35권4호
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• pp.439-445
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• 2017

Transplant production in a plant factory with artificial lighting provides several benefits; (1) rapid and uniform transplant production, (2) high production rate per unit area, and (3) production of disease free transplants production. To improve the growth of runner plants when strawberry transplants are produced in a plant factory, we conducted two experiments to investigate (1) the effect of different light intensity for stock and runner plants on the growth of runner plants, and (2) the effect of different container volume for runner plants on their growth. When the stock and runner plants were grown under nine different light conditions composed of three different light intensities (100, 200, and $400{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPF) for each stock and runner plants, increasing the light intensity for stock plants promoted the growth of runner plants, however, the growth of runner plants was not enhanced by increasing the light intensity for runner plants under same light intensity condition for stock plants. We also cultivated runner plants using plug trays with four different container volumes (21, 34, 73, and 150 mL) for 20 days after placing the stock plants, and found that using plug trays with lager container volume did not enhance the growth of runner plants. These results indicate that providing optimal condition for stock plants, rather than the runner plants, is more important for increasing the growth of the runner plants and that the efficiency of strawberry transplant production in a plant factory can be improved by decreasing light intensity or container volume for runner plants.

• 한국산림과학회지
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• 제89권5호
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• pp.591-597
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• 2000

본 실험은 층층나무(Cornus controversa Hemsl)와 말채나무(Cornus walteri Wanger)의 양묘시 적정 차광율을 구명하고자 상대광도가 100%(대조구), 50%, 30%, 10% 및 2%로 조절된 피음포지에서 실시하였다. 두 수종의 수고생장은 상대광도 50%에서 가장 높은 생장을 보였고, 근원경생장은 대조구와 50%구에서 서로 비슷하게 높은 생장을 기록하였다. 물질생산량을 보면 층층나무의 전체 생산량의 경우 50%에서 자연전광의 대조구보다 높은 생산량을 보였으나 지하부의 생산량은 다소 낮았다. 말채나무는 50%에서 전체 생산량은 대조구보다 낮았으나 지상부 생산량은 다소 높은 생산량을 보였다. 30%이하의 상대광도에서는 수고생장, 근원경생장 및 물질생산량이 급격히 감소하였다. 두 수종 모두 30%에서 가장 높은 T/R율을 기록하였으며 전체적으로 말채나무의 T/R율이 층층나무의 T/R율 보다 높았다. 잎의 엽록소 a와 b 및 전체엽록소 함량은 상대광도가 낮을수록 높아지는 경향을 나타내었다.

• 한국산업융합학회 논문집
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• 제7권4호
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• pp.349-354
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• 2004

The growth mode of the Si layers which were grown on Si(111) by using Ag as surfactant were investigated by intensity oscillations of the RHEED specular spot at the different temperatures. we found that the introduction of Ag as the surfactant alters the growth mode from a three-dimensional clustering mechanism to a two-dimensional layer-by-layer growth. In the growth of Si layers on Si(111) with a surfactant Ag, At $450^{\circ}C$, RHEED intensity oscillation was very stable and periodic from early stage of deposition to 32 ML. RHEED patterns during homoepitaxial growth at $450^{\circ}C$ was changed from $7{\times}7$ structure into ${\sqrt{3}}{\times}{\sqrt{3}}$ structures. Since the ${\sqrt{3}}{\times}{\sqrt{3}}$ structure include no stacking fault, the stacking fault layer seems to be reconstructed into normal stacking one at transition from the $7{\times}7$ structure to a ${\sqrt{3}}{\times}{\sqrt{3}}$ one. We also found that the number of the intensity oscillation of the specular spot for Si growth with a surfactant Ag was more than for Si growth without a surfactant. This result may be explained that the activation energy decrease for the surface diffusion of Si atoms due to segregation of the surfactant toward the growing surface.

• 임산에너지
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• 제19권1호
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• pp.7-12
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• 2000

본 실험은 광도가 곰솔(Pinus thunbergii Parl.) 유묘의 생장과 물질생산에 어떠한 영향을 미치는 가를 알고자 자연전광이 100, 50, 30, 10% 및 2%로 조절된 야외포지에서 1997년 5월부터 1998년 10월까지 실시되었다. 곰솔의 수고생장 및 근원경생장은 1,2차년을 통하여 자연전광에서 가장 높악으며, 50%에서의 수고생장은 1,2차년도 각각 대조구의 96.4, 88.9%로, 근원경생장은 각각 94.1 77.6%로 조상되엇다, 30%이하로 상대광도가 낮아질수록 수고 및 근원경생장이 급격히 감소 되었으며, 근원경생장의 감소율이 수고생장의 감소율보다 높게 나타났다. 2차년도의 2%에서는 시험 유묘 모두가 고사하였다. 물질생산량도 광도가 낮아짐에 따라 감소되었으며, 1, 2차년도 모두 뿌리의 감소율이 잎, 줄기보다 높았고, 1차년도에는 줄기의 감소율이, 2차년도에는 잎이 감소율이 가장 낮았다. T/R율은 1차년도에는 50%에서,3.55, 2차년도에는 10%에서 4.88로 가장 높았다.

• 한국정밀공학회지
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• 제28권4호
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• pp.521-525
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• 2011

It is known that the low-intensity sound stimulation really affect to grow the cell. The cellular growth mechanism, however, does not been clearly identified even the effect on the low-intensity sound stimulation. The purpose of this study is to investigate the effect of low-intensity sound stimulation on the alveolar UC-MSC proliferation. Before the low-intensity sound stimulation is applied, the UC-MSC are cultured for 24 hours to facilitate their attachments. The cells are divided into two groups. And each was exposed to a medium with or without the low-intensity ultrasound stimulation at 71dB intensity level. The UC-MSC are again divided into three treatment groups of group 1, 2, and 3 and exposed to a frequency at 50Hz, 100Hz, and 1000Hz, respectively. In the results, it is investigated that the growth rates of UC-MSC for the stimulated groups were higher than those of control groups. In 1000Hz frequency, the number of UC-MSC cell is significantly higher than control groups (p>0.05). We would put the hypothesis that the cell growth could be enhanced by an appropriate low-intensity sound stimulation.

• ALGAE
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• 제28권2호
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• pp.203-211
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• 2013

Dunaliella salina and Dunaliella bardawil are well known for carotenogenesis, the overproduction of carotenoids, under stress conditions. The effect of high light (HL) and low light (LL) on the growth, morphology, photosynthetic efficiency, and the ${\beta}$-carotene and zeaxanthin production of D. salina CCAP 19/18 and D. bardawil was investigated and compared. Both strains showed similar growth kinetics under LL growth condition, but D. salina CCAP 19/18 was faster. As the light intensity increased, D. salina CCAP 19/18 cells were elongated and D. bardawil cells became larger. Both strains showed decrease of the maximum quantum yield of PSII ($F_v/F_m$) and election transport rate (ETR) under HL growth condition and D. salina CCAP 19/18 was less liable to the light stress. Both strains had about 1.8 and 5 times difference in the $O_2$ evolution rate at LL and HL conditions, respectively. The ${\beta}$-carotene and zeaxanthin production were increased as the light intensity increased in both strains. D. bardawil was more sensitive to light intensity than D. salina CCAP 19/18. The possible application of D. salina CCAP 19/18 as a carotenogenic strain will be discussed.