• Title/Summary/Keyword: shading net

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NPV-BASED 3D ARRAY DESIGN SYSTEM OF ROOF-TOP PHOTOVOLTAICS

  • Kim Se-Jong;Cho Dong-Hyun;Park Hyung-Jin;Yoon Hee-Ro;Koo Kyo-Jin
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.300-303
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    • 2013
  • On BIPV systems, especially roof-top PV systems, the power generation is easier to be reduced due to the shades of facilities nearby, or roof itself. To secure profitability of roof-top PV systems, the optimal design of solar arrays through the precise shading analysis is an important item of design considerations. In this paper, an optimization system for array design of roof-top PVs is to be developed using three-dimensional Geospatial Information System(GIS). The profitability of income and expense is considered through the shading analysis of entire roofs. By applying the system to project for validation, the adequacy and the improvement of NPV of the system were verified compared to expert's design. The system has significance by reason that PV modules are placed through rules established with expert knowledge and geometric rules were applied to reflect the constructability and maintainability.

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Effects of Light and Nitrogen on the Growth of Pokeberry (미국자리공의 생장에 미치는 광과 질소의 영향)

  • 박범진;박용목;최기룡
    • The Korean Journal of Ecology
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    • v.21 no.4
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    • pp.329-335
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    • 1998
  • The growth of Phytolacca L. grown under three light regimes at three nutrient concentrations was analyzed. The effect of shading treatment on plnat growth was greater than that of nutrient treatment. Plant dry mass increased more than 5-fold during 21 days under 33% and 100% irradiances, whereas that was strongly reduced under 8% irradiance. Net assimilation rate decreased with plant growth irrespective of light and nutrient treatments, though the highest net assimilation rate was shown under 100% irradiance. Under 33% irradiance leaf area in plants supplied with nutrient solution increased to such extent as to compensate reduction in net assimilation rate, whic maintains almost identical growth rate with that under 100% irradiance. The relatonship between total plant nitrogen and leaf nitrogen content was dependent on the growth irradiance. Moreover, leaf nitrogen and specific leaf weight were also changed depending on the light and nutrient conditions. Based on these findings, it is suggested that the adaptive characteristics of Pokeberry plant to light and nutrient conditions may contribute to rapid extension of Pokeberry habital in Korea rocently.

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Changes in Growth and Physiological Characteristics of Dendranthema zawadskii var. latiloba (Maxim.) Kitam. and Aster koraiensis Nakai by Shading Treatment (차광처리가 벌개미취와 구절초의 생장 및 생리적 특성에 미치는 영향)

  • Kim, Dong-Hak;Kim, Young-Eun;Kim, Sang-Jun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.4
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    • pp.1-13
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    • 2022
  • This study was conducted to investigate the chlorophyll content, photosynthetic characteristics, and growth characteristics of Aster koraiensis and Dendranthema zawadskii var. latiloba according to shading treatment. A. koraiensis and D. zawadskii grew in four different shading treatment plots (0%, 50%, 75% and 95% of full sunlight) for experiments. It was found that as the shading level increased, the total chlorophyll content increased and dark respiration decreased in both A. koraiensis and D. zawadskii, indicating that A. koraiensis and D. zawadskii increase the utilization efficiency for photosynthesis under low light conditions. In addition, as the shading level increased, the net apparent quantum yield increased, resulting in the highest in the 95% shading plot, but the highest photosynthetic rate, water use efficiency, and leaf mass per area (LMA) were shown in the control group than in the shading treatments. The results showed that A. koraiensis and D. zawadskii are heliophytes showing plasticity to light, and if the light is restricted to continue to shade, it may be detrimental to growth. For healthy growth, it is considered suitable to grow A. koraiensis under full light conditions, and D. zawadskii under the light condition that blocks 0-50% of full sunlight.

Effects on Dry Matter Production and Growth of Zoysia japonica under the Light Environment II. Effect of Dry Matter Production and Growth Construction of Zoysia japonica on a Shade Rate (광환경이 잔디(Zoysia japonica)의 물질생산과 생장에 미치는 영향 II. 차광율이 잔디의 물질생산과 성장해석에 미치는 영향)

  • 도봉현;김광식
    • Asian Journal of Turfgrass Science
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    • v.6 no.2
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    • pp.73-81
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    • 1992
  • This study was designed to estimate on the interaction of the first productivity, light condition and to examine the ecophysiological 'characteristics of Zoysia japonica. Artificial community of Zoysia japonica was analyzed effect of matter production and growth construction under various shading condition. The results summarized this experiment were as follows ; 1. The relative growth rate(RGR) in all experimental plots was high during the growth stage of 20 days after transplanting and then tend to decrease. RGR value in severe shading or short day condition was remarkably decreased from the early growth stage. 2. The net assimilation rate(NAR) was high during the early growth stage after transplanting. and then decreased the growth proceeded. NAR value in the severe shading or short day condition plots was low. 3. The increasing rate of leaf ared ratio(LAR) was high during the early growth stage after transplanting in the control plot and 30% shading plot, but it appeared to be high 40 days after transplanting in the 50% and 70% shading plot. LAR was appeared to be negative correlation against RGR and NAR. 4. The crop growth rate(CGR) in each experimental plot was increased until 50 days after transplanting, and then decreased. After that time, the maximum CGR value appeared in the control plot(1.56g /g, 10days), 60days after transplanting. CGR had positive correlation with LAI. The optimum LAI in the control, 30%, 50%, and 70% shading plots was appeared as 2.10, 1.75, 1.25, and 0.90.

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Proper Light Intensity, Potting Media and Fertilization Level for Potted Hepatica asiatica Nakai (노루귀의 분화재배를 위한 적정 광도, 분용토 및 시비수준)

  • Jeong, Kyeong Jin;Jeon, Hyeon Sik;Chon, Young Shin;Yun, Jae Gill
    • Horticultural Science & Technology
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    • v.33 no.1
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    • pp.24-30
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    • 2015
  • This study was conducted to select proper light intensity, pot media, and fertilization level for potted Hepatica asiatica Nakai native to Korea. The plants were grown under various light intensities (shading rate, 52, 82, 90, 97%) imposed by shading net. Plants grown with 52% shading showed a low survival rate (65%). Survival rate increased as shading increased, with over 80% survival in shading above 90%. Growth indexes such as fresh weight and leaf number did not show any significant difference between shading treatments. Plants grown in a soil mixture of decomposed granite:fertilizer-amended media:Kanumatsuchi (60:10:30, v/v/v) or river sand:fertilizer-amended media:bark (50:20:30) showed over 85% survival. However, plants grown in a soil mixture of river sand:fertilizer-amended media:Kanumatsuchi (50:30:20) or upland:river sand (40:60) showed very low survival, below 60%. Leaf number and plant height were the highest in a soil mixture of decomposed granite:fertilizer-amended media:Kanumatsuchi (60:10:30) as well. To select a proper fertilization level for H. asiatica, hyponex solution diluted 1,000- or 2,000-fold were applied weekly or biweekly. The survival rate was lowest at weekly application with 1,000-fold diluted solution, and no significant difference was observed between other treatments. In conclusion, H. asiatica exhibits preferences for very low light intensity and soil with air permeability, and is adaptable to a broad range of fertilization levels.

Evaluation on the Solar Heat Gain Coefficient of Glazing System installed in internal shading device by experiments according to the NFRC 201 (NFRC 201 실험방법에 의한 내부 차양장치가 적용된 창호의 일사획득계수 평가)

  • Lim, Jae-Han;Song, Seung-Yeong
    • Journal of the Korean Solar Energy Society
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    • v.30 no.3
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    • pp.47-54
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    • 2010
  • Recently the researchers has been interested in the development of the high performance windows such as solar control window using automatic shading devices, air-flow window, selective coating window. In order to assess the energy performance of total fenestration system, the net energy gains or losses through the glazings and windows should be evaluated. It depends on the thermal transmittance (U-value) and the total solar energy transmittance (SHGC, g-value). This study aims to measure the solar heat gain coefficient according to the NFRC 201 standard test method. In results, we could find the result of different SHGC of the glazing system with a different slat angles. The SHGC in case of $90^{\circ}$ of internal slat angle with regard to the window surface is about 0.56, that in case of $45^{\circ}$ is about 0.49 and that in case of $0^{\circ}$ is about 0.33. Significant dependence on the solar radiation intensity and incident angle was found in comparison of the measured and simulated SHGC.

Comparison of Biological Activities of Synurus deltoides (Aiton) Nakai Under Different Shading Conditions

  • Jiang, Yunyao;Noh, Heesum;Wang, Myeong-Hyeon
    • Korean Journal of Plant Resources
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    • v.26 no.6
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    • pp.686-694
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    • 2013
  • Shade treatment of Synurus deltoides (Aiton) Nakai was carried out with 0, 35, and 55% shading net, and samples were marked as no shade, 35% shade, and 55% shade, respectively. We examined in vitro antioxidant and anti-inflammatory capacities using a 1,1-diphenyl-2-2-pricylhydrazyl (DPPH) radical scavenging assay, a reducing power assay, a total antioxidant assay, a metal chelating assay, a superoxide radical scavenging assay, and a nitric oxide inhibition assay. As a result, no shade and 35% shade possessed higher DPPH radical scavenging activity and reducing power ability than that of 55% shade. Notably, no shade had significantly higher total phenolic and flavonoid contents than those in the other samples. No shade exhibited significantly higher total antioxidant activity than that of 35% shade and 55% shade. However, the chelating ability of 55% shade was significantly greater than that of no shade and 35% shade; 55% shade also showed significantly higher anti-inflammatory capacity than that of no shade or 35% shade.

Effect of Shading on the Quality of Raw, Red and White Ginseng and the Contents of Some Minerals in Ginseng Roots (해가림 종류가 수삼, 홍삼 및 백삼의 품질과 무기물 함량에 미치는 영향)

  • 김영호;유연현
    • Journal of Ginseng Research
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    • v.14 no.1
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    • pp.36-43
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    • 1990
  • The quality of raw, red and white ginseng and the contents of some minerals were examined using 6-year-old ginseng roots produced in different shades, thatch and polyethylene net (P..E.). The yield of first and second grade ginseng roots was higher in the thatch shade than in the P.E. shade. The smaller sizes of ginseng routs were probably due to loss of ginseng yield called by alternaria blight in the third and fourth years, and lower quality was dale to more rusty roots in the P.E. shading. For red ginseng. rates of heaven and earth grades were higher in the P.E. than thatch shade. producing red ginseng with less inside cavity Production of white ginseng was higher in the thatch shade than in the P.E. shade. showing a higher yield, better piece grade, lower inside crack and better quality index in the thatch. The contents of some minerals such as K, Ca, Mg and Mn of fine ginseng roots differed between the two shades, some of which had a significant correlation with the quality indices of white ginseng. Keywords Thatch shade, polyethylene shade, alternaria blight, rulsty root, quality of ginseng.

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