• Title/Summary/Keyword: environmental light

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Enhanced Resistance of Transgenic Sweetpotato (Ipomoea batatas Lam.) Plants to Multiple Environmental Stresses Treated with Combination of Water Stress, High Light and High Temperature Stresses

  • Song, Sun-Wha;Kwak, Sang-Soo;Lim, Soon;Kwon, Suk-Yoon;Lee, Haeng-Soon;Park, Yong-Mok
    • Journal of Ecology and Environment
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    • v.29 no.5
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    • pp.479-484
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    • 2006
  • Ecophysiological parameters of non-transgenic sweetpotato (NT) and transgenic sweetpotato (SSA) plants were compared to evaluate their resistance to multiple environmental stresses. Stomatal conductance and transpiration rate in NT plants decreased markedly from Day 6 after water was withheld, whereas those values in SSA plants showed relatively higher level during this period. Osmotic potential in SSA plants was reduced more negatively as leaf water potential decreased from Day 8 after dehydration treatment, while such reduction was not shown in NT plants under water stressed condition. SSA plants showed less membrane damage than in NT plants. As water stress and high light stress, were synchronously applied to NT and SSA plants maximal photochemical efficiency of PS II ($F_v/F_m$) in NT plants markedly decreased, while that in SSA plants was maintained relatively higher level. This trend of changes in $F_v/F_m$ between SSA plants and NT plants was more conspicuous as simultaneously treated with water stress, high light and high temperature stress. These results indicate that SSA plants are more resistive than NT plants to multiple environmental stresses and the enhanced resistive characteristics in SSA plants are based on osmotic adjustment under water stress condition and tolerance of membrane.

A Basic Study on the Demand of the Parents of Students in Eco-Environmental Space at Child Care Center (어린이집의 친환경적 공간요소에 대한 학부모요구에 관한 기초연구)

  • Han, Hae-Ryon;Park, Young-Ki
    • Korean Institute of Interior Design Journal
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    • v.16 no.5
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    • pp.47-54
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    • 2007
  • The change of modern society arouse the issue of the family structure and the demand of upbringing. According to the issue, the need of the upbringing is the big interest in society. This study is on the demand of the parents of students in eco-environmental space in child care center. The purpose of the study makes the suggestion the need of the eco-environmental space in child care center. The study progressed with looking up and giving questionaires in six child care centers which have eco-environmental space in Seoul. 210 questionaires were given out to parents and taken away 180 questionaires. The result of the study, parents required strongly to have the eco-environmental space in child care center. The natural interior materials, nature experimental outdoor ground and exterior garden were preferred overriding. The use of the woods and stones and eco-environmental adhesives are required as the natural Interior materials. And the natural light source can be imported in sky light, side window and atrium. Upcoming study would be directed in child care center without eco-environmental spaces. The next suggestion would be made in the needs of the eco-environmental space in child care center.

Growth of Ulva pertusa Kjellman (Chlorophyta, Ulvophyceae) by a Light-Emitting Diode (LED) Light Source (발광다이오드(LED) 조명을 이용한 녹조 구멍갈파래(Ulva pertusa)의 생장)

  • Kwon, Chun Jung;Choi, Chang Geun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.5
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    • pp.571-574
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    • 2013
  • To determine an efficient growth system for algal cultivation and to develop adequate culture system utilizing LED light, we investigated the effects of fluorescent and light emitting diode (LED) light source on the growth of Ulva pertusa. U. pertusa was cultured at $17^{\circ}C$ under a light intensity of 35 ${\mu}mol$ photons $m^{-2}s^{-1}$ and a 10L:14D photoperiod using either fluorescent or LED lamps. After 1 week of incubation under the same environmental condition, the length and width of Ulva pertusa grown under LED light were 1.5- and 1.9-fold greater, respectively, than the length and width of algae grown under fluorescent light. After two weeks, length and width were 2.6- and 2.0-fold greater, respectively, in algae grown under LED light. Total length and width of Ulva pertusa after three weeks of incubation were 1.7- and 1.2-fold greater in algae grown under LED light than those grown under fluorescent light. Therefore, the LED light induced significantly higher growth of Ulva pertusa than fluorescent light.

A Study on the Characteristics of Using Natural Light in Alvar Aalto's Library (알바 알토 도서관 건축의 자연광 사용 특성에 관한 연구)

  • Chung, Tae-Yong
    • Korean Institute of Interior Design Journal
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    • v.20 no.5
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    • pp.13-22
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    • 2011
  • The purpose of this study is to analyze Alva Aalto's libraries for understanding his efficient induction of natural light. To fulfill this purpose, Alvar Aalto's thought about library and natural light are examined through his working years and building types. The comparison of his libraries on usage of natural light shows different ways of natural light induction based on different locations and programs of libraries. Similarities and differences of Alvar Aalto's library architecture have strong relationship to the usage of natural light in libraries because Alvar Aalto himself regard reading as the core function of library and the efficient use of natural light is the main key of reading. In his natural light planning, regional characteristics including environmental factors and programmatic differences act as a basic standard for natural light plan. Especially, altitude of sun and its path, seasonal features affect the induction way of natural light. While conical skylights used at Viipuri library shows the characteristics of universality in Modernism architecture, later libraries presents not only various kinds of pan-shape plan but different ways of inducing natural light in according to appropriate function. From conical skylight to monitor with curved reflection wall make it possible shed diffused light to reading space and this affects to form Alvar Aalto's organic architecture. As a result, using natural light in Alvar Aalto's library architecture act as the core of forming library concepts and their development.

Growing Response of Cyrtomium falcatum and Rumohra aristata Indoor as Influenced by Light Quality Treatment (실내에서 광질이 도깨비고비와 가는쇠고사리의 생육에 미치는 영향)

  • Bang, Kwang-Ja;Ju, Jin-Hee;Kwon, Min-Hoon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.6
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    • pp.49-53
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    • 2004
  • This study was aimed to promote evergreen ferns native to Korea as a material for interior landscape by investigate effects of light quality on the growth of Cyrtomium falcatum and Rumohra aristata, in an indoor environment that artificial light was used, especially. Result of experiments are as follows; 1. Wavelengths were measured as control(=570~580nm), red(=600~610nm), yellow(=550~580nm), green(=500~510nm) and blue(=430~440nm) between different color film. The order of photon flux density was red>yellow>control>green>blue decreased. 2. Although there was no difference in the growth of Cyrtomium falcatum depending on light quality, in case of fronds with sori and new fronds, there were highest under red film. Fresh weight was no significant in all treatments, but dry weight was increased with green>control>yellow>blue>red in order. 3. In case of Rumohra aristata, there was no difference in its growth, however, number of total fronds was highest under green film. Although fresh weight was increased with yellow film, dry weight was highest under green film.

Distribution and Ecological Characteristics of Native Iris Odesanensis in Mt. Naeyon

  • Ahn, Young-Hee;Lee, Sang-Hyun;Lee, Sung-Je;Kang, Ki-Ho
    • Journal of Environmental Science International
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    • v.15 no.12
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    • pp.1103-1107
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    • 2006
  • Iris odesanensis Y.N. Lee is one kind of species among 54 endangered plant species designated by the Ministry of Environment in Korea. It is very rare native plant throughout the country. Therefore, this study was conducted to investigate the native Iris odesanensis in Mt. Naeyon for their distribution and ecological characteristics. They were mostly distributed mid-slope of the mountain from 443m to 498m altitude. They were located lower part of valley and provided enough humid condition. They had proper light and humidity conditions as they faced south south west, south south east, and south. They were also located at the places deciduous woody plants were distributed for proper light conditions for spring blooming. Iris flowered to use light at the period before the trees thickly covered with foliage. However this unfavorable light condition caused low percentage as 7.04% of blooming individuals in this study. In herbaceous, Vioia chaerophylloides(Regel) W. Hocker, Carex siderosticta Hance, Erythronium japonicum Decne., Oxalis obtriangulata Max., Hepatica asiatica Nakai, Lilium tsingtauense Gilg et cetera were appeared well. We propose that proper pruning of upper branches of the deciduous trees is needed for suitable light condition of management of native sites.

Engineering Characteristics of the Light Weight Soil Used Recycled Stylofoam Beads and Disposal Soils (폐스티로폴 입자와 현장 발생토를 활용한 경량혼합토의 공학적 특성)

  • Shin, Bang-Woong;Lee, Jong-Kyu
    • Journal of the Korean GEO-environmental Society
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    • v.1 no.1
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    • pp.43-50
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    • 2000
  • This paper presents the engineering property of light weight soil made of soil mixed with recycled stylofoam and stabilizer. Recycled stylofoam beads is able to use by lightweight fill materials because it is light, adiabatic, and effective for vibration interception. Especially, recycled stylofoam beads is easy to supply because stylofoam have been recycle item in 1996. In this study, physical and geotechnical properties of the light weight mixed soil(weathered granite soil mixed with Stylofoam Beads) were analyzed by laboratory experiments to examine its suitability for backfill materials. Laboratory tests were performed to evaluated strength, bearing capacity, weight, permeability, microphotograph analysis with variation of mixing ratio. Based on the results, it is concluded that the use of recycled stylofoam beads is acceptable lightweight fill.

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Optimization for Scenedesmus obliquus Cultivation: the Effects of Temperature, Light Intensity and pH on Growth and Biochemical Composition

  • Zhang, Yonggang;Ren, Li;Chu, Huaqiang;Zhou, Xuefei;Yao, Tianming;Zhang, Yalei
    • Microbiology and Biotechnology Letters
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    • v.47 no.4
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    • pp.614-620
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    • 2019
  • Microalgae have been explored as potential host species for biofuel production. Environmental factors affect algal growth and cellular composition. The effects of several key environmental factors, such as temperature, light, and pH of the medium on the growth and biochemical composition of Scenedesmus obliquus were investigated in this study. The highest growth rate of microalgae was observed at an optimal temperature of 25℃, 150 μmol/(m2·s) light intensity, and pH 10.0. The biochemical composition analysis revealed that the carbohydrate content decreased at lower (20℃) or higher temperature (35℃), whereas the protein and lipid contents increase at these temperatures. The fluctuation of light intensity significantly affected the contents of protein, carbohydrate, and lipid. The protein levels varied greatly when the pH of the medium was below 7.0. The carbohydrate and lipid contents significantly increased at pH above 7.0.

Effect of Different Light Intensities on the Growth and Leaf Gas Exchanges in Miscanthus sinensis and Pennisetum purpurascens (참억새 및 수크령의 광도차에 따른 생육변화 및 가스교환에 미치는 영향)

  • Kwack, Hye Ran;Lee, Jong Suk
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.1
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    • pp.110-115
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    • 2004
  • This experiment was conducted to investigate the effect of light intensities on the growth responses, carbohydrate contents and the characteristics of leaf gas exchange in Miscanthus sinensis and Pennisetum purpurascens. The plant height and leaf length were increased to about 30% in the sun. However, those were reduced severely in the shade, and leaf necrosis was also observed. The representative growth index and the dry weight of 2 species were 50% higher than shade and the rate was reduced according to the decrease of light intensities. Total carbohydrate contents showed very similar changes to that of dry weight. However, any notable influences were observed at above the light intensities of 250~500${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in the half shade. The size of spikes and the earliest spiking appeared in the sun and the spike color was decolorized as decreased in light intensities, irrespective of species. Photosynthetic rate of 2 species was 2 times higher in the sun than those in the shade, and it showed the typical photoresponses of sun plant. Stomatal conductances and intercelluar $CO_2$ concetration showed similar changes to that of photosynthetic rate. On the contrary, vapor pressure deficit was increased more in the shade than in the sun.

The Parallel Measurements of Stomatal Apertures and Apoplastic pH on Guard Cells from Epidermal Strips and Intact Leaves of Commelina communis

  • Lee, Joon-Sang
    • Korean Journal of Environmental Biology
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    • v.20 no.1
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    • pp.78-84
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    • 2002
  • The effects of light and darkness on stomatal aperture and guard cell apoplastic pH in the intact leaf and in the isolated epidermal strips of Commelina communis have been investigated. Stomata in the intact leaf opened wide in the light. In contrast, stomata in the isolated epidermal strips did not respond clearly to light. To eucidate the relationship between the stomatal aperture and the guard cell apoplastic pH, apoplastic pH was measured. In the light the guard cell wall of intact leaf was acidified by pH 1.9 units, falling from pH 7.3 to pH 5.4 in the first 10 minutes. On the contrary, apoplastic pH of isolated epidermal strips changed slowly from pH 7.3 to pH 6.9 at 20 min. Stomata in the intact leaf closed rapidly in the dark. On the other hand, stomata in the isolated epidermal strips failed to close in dark. There was a slow increase in apoplastic pH on transfer to the dark after incubation for 1.5 h in the light and the level observed before the experiment was regained after around 40 min. When the isolated epidermal strips were transferred to the dark, apoplastic pH maintained a uniform level of around pH 7.2-7.4. These results indicate that the mechanism of stomatal opening and closing from isolated epidermal strips and intact leaves could be different.