• Title/Summary/Keyword: transpiration.

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Preparation and Physical Characteristics of High-Performance Heat Storage.Release Fabrics with PCMMc : Wet coating process (상전이 마이크로캡슐이 함유된 고기능성 축열.발열 직물의 제조 및 물리적 특성 : 습식코팅)

  • Koo, Kang;Choe, Jong-Deok;Choi, Jong-Suk;Kim, Eun-Ae;Park, Young-Mi
    • Textile Coloration and Finishing
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    • v.19 no.1 s.92
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    • pp.24-30
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    • 2007
  • Heat storage/release system in textile is a useful tool to increase energy efficiency and enhance comfortable microclimate of clothing. Phase change materials(PCM) are used in regulating storage and release properties of thermal energy. To investigate the temperature regulating ability of fabrics with PCM microcapsule(PCMMc), Nylon fabrics were coated with PCMMc via wet processing and they were characterized by SEM, DSC and infrared thermal analyzer. Also, water moisture transpiration, water penetration resistance, peel strength and washing durability of the fabrics were assessed. The water vapor permeation and water penetration resistance decreased with increasing PCMMc content. In DSC analysis, it can be seen that the microencapsulated fabric showed both exothermic md endothermic phenomena at specific temperature. Peel strength was decreased with increasing PCMMc content.

Effectiveness of Silver Thiosulfate Treatment in Reducing Ozone Injury to Tomato Plants (Silver Thiosulfate 처리가 토마토의 오존피해경감에 미치는 효과)

  • 구자형;원동찬;김태일
    • Journal of Korean Society for Atmospheric Environment
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    • v.8 no.1
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    • pp.7-12
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    • 1992
  • This study was conducted to determine the effectiveness of silver thiosulfate(STS) in reducing $O_3$ injury to tomato plants(Lycopersicon esculentm Mill. 'Pink Glory'). Two days prior to $O_3$ fumigation, plants were given a foliar spray of STS solution at concentrations of 0, 0.2, 0.4, 0.6 mM contained with 0.05% Tween-20. STS concentrations below 0.6 mM were significantly effective in providing protection aginst $O_3$ exposure(16 h at 0.3 ppm). STS reduced leaf injury rate, defoliation of cotyledons, ethylene production and degree of epinasty induced by $O_3$ injury. STS slightly increased ethylene production in non-$O_3$-fumigated plants, but changes of chlorophyll content and transpiration rate on a whole plant basis were not observed. In $O_3$-fumigated plants, STS treatment reduced chlorophyll destruction but did not affect transpiration rate. STS treatment seemed not to affect peroxidase(POD) and superoxide dismutase (SOD) activity in non-fumigated plants but reduced increasing activity of POD by $O_3$ fumigation. However, such an effect as above was not found in SOD activity. Even though enzymatic protection effects were not confirmed, the fact that reduction of acute injury rate was attained for 16 h fumigation indicates that the phytoprotective effects of STS are not necessarily related to blocking the action of strees-induced-ethylene as an anti-ethylene agent.

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Responses of Transgenic Tobacco Plants Overexpressing Superoxide Dismutase and Ascorbate Peroxidase in Chloroplasts to Water Stress (Superoxide Dismutase와 Ascorbate Peroxidase를 엽록체에 과발현하는 형질전환 담배의 수분스트레스에 대한 반응)

  • 최선미;권석윤;곽상수;박용목
    • Journal of Environmental Science International
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    • v.10 no.1
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    • pp.79-84
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    • 2001
  • To assess resistance of transgenic tobacco plants which overexpress superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts to water stress, changes in leaf water potential, turgor potential, stomatal conductance and transpiration rate were measured. Leaf water potential in all plants remained high up to day 4 after withholding water but thereafter decreased markedly. In spite of a remarkable decrease in leaf water potential, some of transgenic plants maintained higher turgor potential compared with control plant on day 12. In particular, the transgenic plant expressing MnSOD showed an outstanding maintenance in turgor pressure by osmotic adjustment throughout the experiment, resulting in high stomatal conductance and transpiration rate. However, among transgenic plants, osmotic potential was reduced more effectively in multiple transformants such as the double transformant expressing both MnSOD and APX, and the triple transformant expressing CuznSOD, MnSOD and APX than single transformants. Consequently, further research is needed to get general agreement on the tolerance of transgenic plants to water stress at different growth stages for each transgenic plant.

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Leaf Temperature Characteristics being Affected by Light Regimes (광조건에 따른 식물의 엽온 특성)

  • Park, Yong-Mok
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1599-1605
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    • 2011
  • To evaluate heat environment surrounding plants diurnal change of leaf temperature in the broad-leaved deciduous and evergreen trees was measured with microclimatic environmental factors including global solar radiation, and upward and downward long wave radiation. Maximum daily solar radiation was 961.2 and 976.3 w/$m^2$ in August 9 and 23, respectively. Upward long wave radiation was slightly higher than downward long wave radiation, showing 404.2 w/$m^2$ in August 9 and 394.5 w/$m^2$ in August 23. In addition, daily maximum vapor pressure deficit was 5.42 and 6.84 kPa in August 9 and 23, respectively, indicating high evaporative demand. Quercus glauca and Acer mono was differently responded to changing light regimes. On August 9, leaf temperature at the top-positioned leaves of Acer plants was higher than air temperature as well as those of Quercus plants in the morning. This indicates that stomata in Acer plants were closed by heat stress or water stress in the morning, while Quercus plant maintained active transpiration by opening stomata. These results indicated that improved light regimes such as gap opening in the closed forest may not always affect positively in the physiology of understory plants.

Effect of Irrigation Automation Using Stem Diameter Variation as an Indicator of Irrigation Timing in Greenhouse Tomato (온실재배 토마토에서 관개시기 진단지표로 경직경 변화를 이용한 관개 자동화 효과)

  • 이변우;신재훈
    • Journal of Bio-Environment Control
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    • v.8 no.4
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    • pp.232-241
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    • 1999
  • The automatic irrigation system using the stem diameter monitoring and the transpiration model for the determination, respectively, of irrigation timing and amount was designed and evaluated for its applicability in pot and field culture of greenhouse tomato. In the pot culture condition, the yield and quality of greenhouse tomato were improved when irrigation was practiced based on the stem diameter monitoring and the transpiration model as compared to the irrigation practice based on soil moisture monitoring. However, the effects were not significant in the field culture condition.

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Effects of Simulated Acid Rain on Histology, Water Status and Growth of Pinus densiflora (인공산성빗물이 소나무의 조직, 수분수지 및 생장에 미치는 영향)

  • 이창석;길지현;유영한
    • The Korean Journal of Ecology
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    • v.21 no.2
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    • pp.117-124
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    • 1998
  • To clarify the effects of acid precipitates on histological damage, water status, and growth of Pinus densiflora green house experiment applyin simulated acid rain was carried out. Contact angle of water droplet on needles of P. densiflora seedlings treated with simulated acid rain of different pHs simulated acid rain was, the more rapid transpiration was. Leaf water potential after water withdrawal was also reduced rapidly in proportion to acidity of simulated acid rain. Height growth of P. densiflora seedlings treated with simulated acid rain of pH 2 decreased, while growth of seedlings treated with that of pH 3 and 4 increased comparing with that treated with normal rain of pH 5.6. pH of cultivated soil in pH 2 plot was acidified with the amount of simulated acid rain applied but that in pH 3 and 4 plots did not show any directional change. From those results, it could be interpreted that decrease of height growth in pH 2 plot was originated from multiple effects of water deficit from rapid transpiration and soil acidification. On the other hand, increased of height growth in pH 3 and 4 plots would be originated from the supply of N and S included in simulated acid rain.

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Effects of the ectomycorrhizal fungus Pisolithus tinctorius and Cd on physiological properties and Cd uptake by hybrid poplar Populus alba × glandulosa

  • Han, Sim-Hee;Kim, Du-Hyun;Lee, Jae-Cheon
    • Journal of Ecology and Environment
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    • v.34 no.4
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    • pp.393-400
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    • 2011
  • The effects of the ectomycorrhizal fungus Pisolithus tinctorius and cadmium (Cd) on physiological properties and Cd uptake by Populus alba ${\times}$ glandulosa was investigated under greenhouse conditions. Cd treatment decreased the photosynthetic rate ($P_N$) of both non-mycorrhizal (NM) plants (16.3%) and ectomycorrhizal (ECM) plants (11.5%). In addition, the reduction in total dry weight by Cd treatment was greater in ECM plants (24.3%) than that in NM plants (17.6%). Mycorrhizal infection increased the $P_N$ and transpiration rate in both control and Cd-treated plants. Cd treatment increased superoxide dismutase (SOD) activity and decreased glutathione reductase activity, and the increase of SOD activity by Cd treatment was greater in NM plants (40.3%) than that in ECM plants (3.7%). Thiol content increased in both NM and ECM plants treated with Cd solution, and the increase in thiol content in NM plants (43.9%) was greater than that of ECM plants (15.6%). Cd uptake in the leaves, stems, and roots of ECM plants was 69.9%, 167.2% and 72.8%, respectively, higher than in the NM plants. However, the increase in Cd uptake ability of ECM plants resulted in a reduction in dry weight.

Changes of Rutin Content and Photosynthesis Rate of Korean Buckwheat Cultivars under Various Environmental Stresses

  • Yoon, Byeong-Sung;Kwun, Hyok-Oun;Shin, Sang-Eun;Jin, Cheng-Wu;Yu, Chang-Yeon;Cho, Dong-Ha
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.4
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    • pp.284-288
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    • 2003
  • This study was conducted to classify photosynthesis rate and changes of rutin content of Korean buckwheat (cv. Chunchon-jaerae and Yangjeul-memil) treated with salinity, UV-C and low temperature. In case of cv. Chunchon-jaerae and Yangjeul-memil, according to the salt stress, transpiration rate, stomatal conductance and photosynthesis rate were decreased. Both cultivars also showed decrease of transpiration rate and photosynthesis rate under the UV-C. Rutin contents within leaf and stem of cv. Yangjeul-memil were decreased when NaCl concentration was high. Rutin contents within leaf and stem of cv. Yangjeul-memil were generally decreased when the time laps under the UV-C stress. Rutin contents within leaf and stem of cv. Chunchon-jaerae was also generally decreased when the time laps under the low temperature stress.

Effect of NaCl Concentration on Photosynthesis and Mineral Content of Barley Seedlings under Solution Culture

  • Cho, Jin-Woong;Kim, Choong-Soo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.43 no.3
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    • pp.152-156
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    • 1998
  • This study was conducted to elucidate the changes of photosynthetic ability and cation content in barley cultivar seedlings cultured for 10 and 30 days with different NaCl concentrations containing 1/4 Hoagland solutions. At the highest NaCl concentration, the weight of dry matter and the shoot/root ratio (S/R ratio) were decreased. Thus, shoots were affected more than roots by NaCl treatment. The S/R ratio decreased more in 'Neulssalbori' than in 'Bunong' by the NaCl treatment. The. internal $Na^+$ concentration increased greatly with the highest NaCl concentration, but $K^+$ concentration in plants decreased with the highest NaCl treatment. The $Ca^{2+}$ concentration had a small change with NaCl concentrations. Thus $Na^+$/$K^+$and $Na^+$/$Ca^{2+}$ratios increased with the highest concentration. The chlorophyll content (%/dry weight) of seedlings decreased at higher NaCl levels except for Bunong in 30 day old seedlings. The photosynthetic ability decreased only for Neulssalbori in the 10 days NaCl treatment. The stomatal conductance, and transpiration had decreased in the 10 day old seedlings, but not with 30 day old seedlings.

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Estimation of Evapotranspiration in a Forest Watershed in Central Korea (중부(中部) 산림(山林) 지역(地域)의 증발산량(蒸發散量) 추정(推定))

  • Kim, Jesu
    • Journal of Korean Society of Forest Science
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    • v.88 no.1
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    • pp.86-92
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    • 1999
  • Evapotranspiration is one of important variables affecting ecosystem processes such as vegetation distribution and growth. It acts as a limiting factor for natural water resource management. The transpiration of vegetation is mainly determined by climatic factors. The lower slope of the study area was densely forested with Pinus densiflora S. et Z. of 8 m height, and the upper slope was covered with poorly grown Pinus densiflora S. et Z. and Quercus trees. The amount of evapotranspiration was estimated to 590.3 mm/yr by annual water budget method. The canopy resistance of Penman-Monteith model was determined as 99 s/m. Seasonal evapotranspiration can be estimated with the calculated evaporation and the canopy resistance. The amount of evapotranspiration peaked in May. That is considered from both the direct evaporation of intercepted rainfall and the transpiration of vegetation during the dry spring season.

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