• 제목/요약/키워드: WATER STRESS

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Effects of Elevated CO2 Concentration and Temperature on Physiological Characters of Liriodendron tulipifera (CO2농도 및 온도 상승이 백합나무의 생리적 특성에 미치는 영향)

  • Lee, Ha-Soo;Lee, Solji;Lee, Jae-Cheon;Kim, Ki Woo;Kim, Pan-Gi
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.15 no.3
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    • pp.145-152
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    • 2013
  • This study aimed to investigate the growth and physiological characters of Liriodendron tulipifera seedlings in responses to two different levels of elevated air temperature and $CO_2$ concentration. The seedlings were grown in environment-controlled growth chambers with two combinations of air temperature and $CO_2$ conditions: (1) $22^{\circ}C$ + ambient $CO_2$ $380{\mu}mol\;mol^{-1}$ and (2) $27^{\circ}C$ + $770{\mu}mol\;mol^{-1}$. Physiological characters such as growth, photosynthesis, and water use efficiency, were monitored for 85 days. The seedlings under the elevated treatment showed a greater amount of growth in tree height, compared with those under the control. Regarding the characteristics of assimilatory organs, the elevated treatment resulted in a greater amount of total leaf area, leaf unfolding, and dry weight per leaf area. No significant differences were found in photosynthesis capacity between the two treatments. The increase in water use efficiency with increased intercellular $CO_2$ partial pressure appeared overall lower in the seedling under the elevated treatment, compared with those under the control. The total leaf area of the seedlings under the elevated treatment was larger than that under the control, indicating a higher amount of photosynthesis. In addition, an increase of root growth was noted under the elevated treatment. A resistance mechanism of water stress may be attributed to a higher amount of organ growth as well as the tree height under the elevated treatment than the control.

Relationship between Drought-Tolerance and Physiological Parameters in Korean Barley Genotypes (보리 품종의 한발저항성과 생리적 지표와의 상관)

  • 이변우;부금동;백남천;김정곤
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.6
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    • pp.516-526
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    • 2003
  • Thirty-six barley varieties including Korean modern and local varieties were tested for drought-tolerance in the field of plastic rain shelter, Drought treatment was initiated at initial tillering stage (March 27, 2002) by withholding irrigation and lasted until harvest. Soil water potential maintained at around -0.05㎫ in the control plot and varied from -0.05㎫ (at the initial stage of drought treatment) to -0.29㎫ in the drought treatment plot. At forty days after drought treatment, relative water content (RWC), osmotic potential (OP), osmotic adjustment (OA), and $^{13}\textrm{C}$ discrimination ($\Delta$) were measured and then plants were sampled for leaf area index (LAI) and dry weight (DW). Barley was harvested at maturity for determining DW, grain yield, 1000 grains weight and number of spikelet. The tested varieties revealed wide spectrum of drought tolerance. Dongbori-1, Chalbori, Changyeongjaerae, Samdobori and Weolseong 87-31 showed strong drought-tolerance while Songhagbori and Suwonmaeg360 showed weak drought-tolerance. The drought injury indexes (drought/control ratio) of DW and yield revealed significant positive correlation with leaf RWC in drought treatment plot and $\Delta$ in the control plot, but obvious negative correlation with leaf OP and OA under drought condition. In addition, all the drought indexes of OP, $\Delta$ and RWC showed obvious positive correlation with the drought injury indexes of DW, 1000 grain weight and yield. Thus, OP and RWC under drought condition and $\Delta$ under well-watered condition would be used as the evaluation criteria for drought- tolerance of barley genotypes. However, further investigation is needed for the relationship between $\Delta$ and drought-tolerance as the other reports were not consistent with our result.

Effects of Heating Temperature and Time, Salt and pH on the Texture and Color Characteristics of Whole Egg Gel (계란찜의 텍스쳐와 색에 미치는 가열온도와 시간, pH 및 소금의 영향)

  • 김경미;김종군;김주숙;김우정
    • The Korean Journal of Food And Nutrition
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    • v.17 no.2
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    • pp.163-170
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    • 2004
  • Effect of several factors for Preparation of whole egg gel (WEG) on texture and color of WEG were investigated in this study. The factors studied were amount of water addition, heating temperature and time, pH and NaCl. The whole egg gel was prepared by mixing of whole egg and steaming at 100$^{\circ}C$ for 7 min followed by cooling at 22$^{\circ}C$ for 90 min. The results showed that the increase in water addition decreased significantly with viscosity values of whole egg solution (WES) and the addition of more than 50% water resulted in a significant decrease in the stress at failure (SF) and the hardness of WEG. The color a and b values of WES decreased and the value of WEG also decreased significantly in negative range. The increase in heating temperature decreased the coagulation time and increased in SF while SF decreased. Addition of NaCl up to 1.3% resulted a significant increase in SF and hardness and a little changes in color of WEG. As the pH of WES changed from 4.0 to 10.0, the viscosity of WES was minimal and SF and hardness were maximal at pH 6.0. The L and b values of WEG were significantly reduced at higher pH values of 8.0.

Detailed Deterioration Evaluation and Analysis of Conservation Environment for the Seosanmaaesamjonbulsang (Rock-carved Triad Buddha in Seosan), Korea (서산마애삼존불상의 정밀 손상도 평가와 보존환경 분석)

  • Lee, Sun-Myung;Lee, Chan-Hee;Kim, Ji-Young
    • Journal of Conservation Science
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    • v.26 no.3
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    • pp.277-294
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    • 2010
  • The Seosanmaaesamjonbulsang (National Treasure No. 84) consists of light gray and coarse to mediumgrained biotite granite with partly developed pegmatite and quartz vein. The host rock is divided into dozens of rock blocks with various shape along irregular discontinuity plane. The evaluation results of discontinuity systems reveal that the host rock were exposed to instable sloping environments. Results of deterioration diagnosis show that the degree of damage has been made worse by physical weathering and surface discoloration laying stress on part that vertical and horizontal joints are massed. Generally, deterioration rate of the triad Buddha surface cover with 42.7%, however, the rate of physical weathering and surface discoloration are subdivided to 9.6% and 33.1%, respectively. Ultrasonic measurements indicate that the triad Buddha was reached highly weathered grade in general. And the rock material was weaken to show low velocity zone of 1,000m/s along irregular joint systems. Indoor and outdoor mean relative humidity of the shelter was recorded more than 70% during every season, and high frequency appears in high relative humidity range over 95%. Such environments seem to have produced dew condensation on the rock surface with rainfall and supply water, promoted physical, chemical and biological weathering along crack and joint, resulting in high permeation of water and percentage of water content. Therefore, it is judged that for scientific conservation of the triad Buddha it needs environment control through persistent preservation environment monitoring including water problem.

Effect of PVP on the Physical Stability of O/W Emulsion (O/W 유제의 물리적 안정성에 대한 PVP의 영향)

  • Oh, In-Joon;Lee, Mi-Young;Lee, Jeong-Min;Lee, Yong-Bok;Shin, Sang-Chul;Choi, Bo-Guil;Kim, Chong-Kook
    • Journal of Pharmaceutical Investigation
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    • v.27 no.4
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    • pp.287-293
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    • 1997
  • To make a stable o/w emulsion, the effects of egg lecithin as an emulsifier and polyvinylpyrrolidone (PVP) as an auxiliary emulsifier on the physical stability of emulsion were investigated. The oil-in-water emulsion system was manufactured by microfluidizer and evaluated the physical stability. Average particle size and size distribution of emulsion was measured by dynamic light scattering analyzer and interfacial tension was measured. From the interfacial tension tested, critical micelle concentration of the egg lecithin was 0.1 %w/v and optimal concentration for the preparation of emulsion was 1.0 %w/v. The mean particle size was about $0.2\;{\mu}m$ which was suitable for injections. The short-term accelerated stability studies were conducted by centrifugation, freeze-thaw method and shaking of the emulsion samples. The addition of PVP was caused the reduction in the particle size and improved the physical stability of emulsion. These results suggested that a mixed interfacial film comprising the egg lecithin and PVP was formed at the o/w interface and it was effective in preventing phase separation under thermic or mechanical stress. We used antineoplaston A10 (A10) as a model drug which is peptide and amino acid derivative having a action to the living organism against the development of neoplastic growth by a nonimmunological progress. It has a poor solubility in water and there may be a difficulty in formulation of A10. Emulsion formulation study about A10 was performed. Solubility of A10 in emulsion was about five times as high as that in water. From the results of solubility and partition coefficient, almost A10 molecules in o/w emulsion exist in the interface between oil and water.

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Case Study of the Stability of a Large Cut-Slope at a Tunnel Portal (터널 입구부 대절토 사면 안정성 사례 연구)

  • Park, Dong Soon;Bae, Jong-Soem
    • The Journal of Engineering Geology
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    • v.25 no.1
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    • pp.115-129
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    • 2015
  • The cut-slope of a large-sectional tunnel portal is recognized as a potential area of weakness due to unstable stress distribution and possible permanent displacement. This paper presents a case study of a slope failure and remediation for a large-scale cut-slope at a tunnel portal. Extensive rock-slope brittle failure occurred along discontinuities in the rock mass after 46 mm of rainfall, which caused instability of the upper part of the cut-slope. Based on a geological survey and face mapping, the reason for failure is believed to be the presence of thin clay fill in discontinuities in the weathered rock mass and consequent saturationinduced joint weakening. The granite-gneiss rock mass has a high content of alkali-feldspar, indicating a vulnerability to weathering. Immediately before the slope failure, a sharp increase in displacement rate was indicated by settlement-time histories, and this observation can contribute to the safety management criteria for slope stability. In this case study, emergency remediation was performed to prevent further hazard and to facilitate reconstruction, and counterweight fill and concrete filling of voids were successfully applied. For ultimate remediation, the grid anchor-blocks were used for slope stabilization, and additional rock bolts and grouting were applied inside the tunnel. Limit-equilibrium slope stability analysis and analyses of strereographic projections confirmed the instability of the original slope and the effectiveness of reinforcing methods. After the application of reinforcing measures, instrumental monitoring indicated that the slope and the tunnel remained stable. This case study is expected to serve as a valuable reference for similar engineering cases of large-sectional slope stability.

Ground behaviour according to ground water locations due to tunnelling below shallow foundation by laboratory model test (실내모형시험을 통한 얕은 기초 하부에서 터널굴착 시 지하수위 위치에 따른 지반거동)

  • Lee, Hyun-Gu;Kong, Suk-Min;Oh, Dong-Wook;Lee, Yong-Joo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.3
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    • pp.575-592
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    • 2018
  • Tunnelling is getting more important solutions for problems induced by the growth population in urban areas. Many studies on tunnelling below existing structure are carried out by many researchers. In general, however, ground water condition is ignored for most of researches using laboratory model test, so far. In case of ground behavior, error can occur if the result of effective stress related to hydraulic condition can't be taken into considerations. In this study, therefore, laboratory model test and the close range photogrammetry were conducted to investigate behaviour of ground and shallow foundation using newly device drainage system which is available to express the ground water condition. Also, numerical analysis was carried out to compare to results from the laboratory model test, and was performed with two methods, one is plastic and the other one is fully coupled analysis. Results from those two methods were compared to that of the laboratory model test.

Efficiency Study of Rose and Lavender Essential oil in the Physiologic Active Changes of Skin Treated with Surfactant (계면활성제에 의한 피부 생리적 활성 변화에 대한 Rose, Lavender essential oil의 유효성 연구)

  • Nam, Jeung-Hae;Choi, Jeung-Sook
    • Journal of the Korean Society of Fashion and Beauty
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    • v.3 no.3 s.3
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    • pp.48-55
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    • 2005
  • The summary of a study of efficacy of Rose essential oil and Lavender essential oil against physiologic active change s of skin caused to surfactant is as follows. 1. In feed intake efficiency, there is more significant difference than control group, and then in water intake, there are significant differences between each group. It is presented that the water intake efficiency ratio of the group treated by Rose essential oil and Lavender essential oil is higher than all of groups to be participated in experiment. And then, the reason that the group treated Lavender essential oil is lower than any other group is needed water intake to be caused by stress. 2. As the result of serum analysis, in atherosclerotic index(A.I), the cholesterol of control group is higher than that of the group treated. As HDL cholesterol is activated, the dan1aged group is higher than control group, in LDL cholesterol the control group is higher. It is seen that the damaged group of the quantity of HDL cholesterol is lower frequently in A.I. This fact is presented that HDL cholesterol that cholesterol is exhausted is changed, because of the dan1aged group that replacement is activated. 3. As the observed result of alteration of sebaceous glands, it is appeared that the demage of sebaceous glands is destroyed in the damaged group. It is observed that epidermis of the group applied by Rose essential oil after treated surfactant is dry, secretion of phenomenon of water and sebum is appeared more. It is observed that the epidermis recovery of the group applied by Lavender essential oil after treated surfactant is insufficient. And then it is seen that stratum corneum is recovered and the quantity of sebum secretion is decreased. 4. As the observed result of alteration of Mast cell group treated by Rose essential oil and Lavender essential oil for 3 weeks Luna's stain(${\times}100$), it is observed that the damaged group treated by Lavender essential oil is numerous in alteration of mast cell's number and Mast cell's size is larger than the dan1aged group. It is presented that the Mast cell's number and Mast cell's size is larger than the damaged group, the Mast cell's size and quantity of the group treated by Rose essential oil and Lavender essential oil is decreased more.

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Properties of Porphyran and Hemicellulose extracted with Different extract Solutions and Enzymatic Pretreatments from Porphyra (추출 용매 및 효소 전처리 방법에 따른 포피란과 헤미셀루로오즈의 특성)

  • AN, Se-Ra;KOO, Jae-Geun
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.1
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    • pp.108-117
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    • 2017
  • Laver, Porphyra, is distinctive for its high content of proteins and polysaccharides such as porphyran and hemicellulose. The chemical properties of the polysaccharides extracted with different extraction methods such as hot water, dilute acid(pH 4.0) or alkali solution(2N NaOH) were examined to investigate the suitable extraction conditions for porphyran and hemicellulose from laver. For porphyran extraction, dilute acid solution was more preferable to hot water and alkali solution because of its higher 3,6-anhydrogalactose content and lower protein content. However, alkali solution was more suitable to extract the hemicellulose because of higher mannose content indicating the extraction of mannan. To decrease contamination of the polysaccharides with protein, the dried lavers were pretreated with enzymes (Protamex, Flavourzyme, Alcalase, Viscozyme) before hot water extraction. All enzyme pretreatments increased the yield of polysaccharides by compared with control (enzyme unpretreated) and Flavourzyme pretreatment was most effective to decrease protein contamination in the polysaccharide. All viscosities of porphyran solutions pretreated by enzymes were lower compared to the control porphyran solution and showed pseudoplastic behavior with yield stress. In case of alkali extraction of residues obtained after enzyme hydrolysis and hot water extraction, protease pretreatment increased the mannose contents in the polysaccharide while the xylose content was increased by Viscozyme pretreatment.

Shear Strength Characteristics of Weathered Granite Soil below the Freezing Point (동결온도 조건에서의 화강풍화토 전단강도 특성에 관한 연구)

  • Lee, Joonyong;Choi, Changho
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.7
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    • pp.19-29
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    • 2013
  • Analysis via classical soil mechanics theory is either ineffective or inappropriate for fully describing stress distribution or failure conditions in cold regions, since mechanical properties of soils in cold regions are different from those reported in the classical soil mechanics theory. Therefore, collecting and analyzing technical data, and systematic and specialized research for cold regions are required for design and construction of the structure in cold regions. Freezing and thawing repeat in active layer of permafrost region, and a loading condition affecting the structure changes. Therefore, the reliable analysis of mechanical properties of frozen soils according to various conditions is prerequisite for design and construction of the structure in cold regions, since mechanical properties of frozen soils are sensitive to temperature condition, water content, grain size, relative density, and loading rate. In this research, the direct shear apparatus which operates at 30 degrees below zero and large-scaled low temperature chamber are used for evaluating shear strength characteristics of frozen soils. Weathered granite soil is used to analyzed the shear strength characteristics with varying freezing temperature condition, vertical confining pressure, relative density, and water content. This research shows that the shear strength of weathered granite soil is sensitively affected by various conditions such as freezing temperature conditions, normal stresses, relative densities, and water contents.