• Title/Summary/Keyword: soil saturation

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Effect of different fertilizer application on the dry matter production and leaf photosynthetic of Yacon(Polymnia sonchifolia) (시비수준의 차이가 야콘의 물질생산과 광합성속도에 미치는 영향)

  • 조동하
    • Korean Journal of Plant Resources
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    • v.9 no.3
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    • pp.274-278
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    • 1996
  • This study was conducted to examine the dry matter production and leaf photosynthesis under different fertilizer application in Yacon(Polymnia sonchifolia)plants. Under field conditions, dry matter production of stable mature application plot(S-1) was much larger than non-treated control plot(CTL), but bulb dry weight of 10kg nitrogen application plot per 10a (N-10) was not differentiated from CTL. The maximum photosynthetic rates increased in Yacon plants grown at S-1 while in the rates of CTL reduced under glasshouse in the same treated pot condition. The optimum temperature for the highly photosynthetic rates is about $34{\pm}3^{\circ}C$, and the rates did decrease by stomatal resistance below 28℃. The estimated light saturation point was $1200{\mu}mol{\cdot}m^{-2}s^1$. The results of this study indicate that soil conditions were highly related to dry matter production and leaf photosynthesis rate in Yacon plants.

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CLSM Analysis of Change in Roughness and Physical Properties of Granite after Freeze-Thaw Experiments (CLSM을 이용한 동결/융해 실험 후 화강암 시료의 표면 및 물성변화 분석)

  • Jeong, Jongtaek;Choi, Junghae;Chae, Byung-Gon;Jang, Bo-An
    • The Journal of Engineering Geology
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    • v.23 no.3
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    • pp.271-281
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    • 2013
  • Freeze-thaw experiments were conducted to evaluate changes in surface roughness and physical properties in samples of granite from Ilgwang and Imki mines, Korea. The temperature range in the experiments was $-20^{\circ}C$ to $40^{\circ}C$, based on typical summer and winter temperatures in Korea, and the surface was observed every 20 cycles. One cycle comprised 1 hour of heating or cooling of the samples and 1 hour during which the target temperature was maintained. With increasing repetitions of the freeze-thaw experiment, porosity increased by 0.05%-0.15% in the two samples and the dry weight increased, whereas the volume of the soil and saturation weight decreased. Observations by confocal laser scanning microscope (CLSM) revealed that line and surface roughness parameters showed a tendency to increase and decrease, respectively, with elapsed time. Changes in surface roughness were apparent on the CLSM images.

Hydrochemical Properties of the Groundwater Used for the Natural Mineral Waters in Precambrian Metamorphic Terrains, Korea (선캄브리아기 변성암지역에 분포하는 먹는 샘물 지하수의 수리화학적 특성)

  • 성익환;추창오;조병욱;이병대;김통권;이인호
    • Journal of the Korean Society of Groundwater Environment
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    • v.5 no.4
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    • pp.203-209
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    • 1998
  • The quality of groundwater used for natural mineral water should be strictly regulated on international level by hydrogeology experts and officials because groundwater is greatly subjected to contaminations and its aquifer system may be easily destroyed by external reasons. A total of 18 natural mineral water plants exist in Precambrian metamorphic terrains of the Gyunggi massif and Yeungam massif. The g개undwater quality for the natural mineral water investigated in hydrochemical aspects shows that pH ranges from 6.85 to 8.02 with an average of 7.52. The electric conductivity (EC) and hardness average 134.1 $\mu$S/cm and 43.5, respectively, which are relatively low to the total average (151.4 $\mu$S/cm and 57.9). The contents of major cations and anions are in the order of $Ca^{2+}$$Na^{+}$>Mg$^{2+}$>K$^{+}$ and HCO$_3$$^{-}$ >SO$_4$$^{2-}$ >Cl$^{-}$ >F$^{-}$ , respectively. The dominant water types determined by Piper diagram are $Ca^{2+}$$Na^{+}$-HCO$^{-}$ $_3$and $Ca^{2+}$-HCO$^{-}$ $_3$, mainly due to the dissolution of plagioclase in the host rocks. Representative correlation coefficients between chemical species are $Ca^{2+}$-HCO$^{-}$ $_3$(0.92), $Ca^{2+}$-Cl$^{-}$ (0.63), $Na^{+}$-F$^{-}$ (0.67), HCO$^{-}$ $_3$-Cl$^{-}$ (0.66), and $Na^{+}$-HCO$^{-}$ $_3$(0.63). The determinative. coefficients between $Ca^{2+}$ and HCO$^{-}$ $_3$, and (Ca$^{2+}$$Na^{+}$+K$^{+}$ and EC art highest among the elements. According to the saturation index, most chemical species are undersaturated with respect to major minerals, except for some silica phases. In viewpoint of phase equilibrium, the chemical evolution of the groundwater may continue to proceed with increasing pH because the groundwater is undersaturated with respect to feldspars.

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Isolation and production of soymilk-clotting enzymes from Bacillus sp. K-324-7 (대두유 응고효소 생산에 관한 연구)

  • Lee, Gi-Soung;Han, Myun-Soo;Shim, Sang-Kook;Chung, Dong-Hyo
    • Applied Biological Chemistry
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    • v.33 no.2
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    • pp.154-160
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    • 1990
  • A bacterial strain which was capable of producing extracellular soymilk-clotting enzyme was isolated from soil samples during the course of screening test. The characteristics of the isolated strain K-324-7, indicated that the strain belonged to species of Bacillus cereus. The crude purification of this enzyme was precipitated by salting out with ammonium sulfate of 0.8 saturation. The optimal pH for the enzyme activity was at $6.1{\sim}7.0$ and below $50^{\circ}C$. The optimal culture medium for the production of soymilk-clotting enzyme were consisted of 0.2% glucose, 0.2% peptone, and 0.5% $KH_2PO_4$ with initial pH value of 6.5. The activity of enzyme was maximum when the microbe was cultured for 3 days at $35^{\circ}C$.

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Assessment of the Models for Predicting the Thermal Conductivity of Saturated Kaolinite (포화된 카올리나이트를 이용한 열전도계수 예측모델의 신뢰성 검토)

  • Lee, Jangguen;Kim, Hakseung;Kang, Jaemo;Kim, Youngseok;Bae, Gyujin
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.3
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    • pp.21-27
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    • 2012
  • Estimating the thermal conductivity of clayey soils is important for enhancing the performance of geoengineering structures in cold regions and clay barriers for nuclear waste repositories, but specimen disturbance, saturation, and heat boundary conditions of the test apparatus hinder reliable measurements of the thermal conductivity of saturated clayey soils. This paper presents the results of an experimental study carried out using modified consolidation tests with the needle probe method to measure thermal conductivity. Experimental consolidation tests with saturated kaolinite were performed to investigate the effect of effective stress and dry density on thermal conductivity for saturated kaolinite. In addition, thermal conductivity of soil particles were thoroughly investigated and experimental results were used to evaluate the accuracy of the models to predict thermal conductivity.

Water Deficit of Pitch Pines Caused by Superficial Rooting and Air Pollutants in Seoul and Its Vicinity

  • Joon-Ho kim;Rhyu, Tae-Cheol
    • Journal of Plant Biology
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    • v.37 no.3
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    • pp.309-316
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    • 1994
  • To make regional comparisons of water status of pitch pine, the temporal changes of water status in pitch pine were investigated at different areas; urban Seoul (heavily polluted area), surburb of Seoul (lightly polluted area), and rural area (control). The effects of air pollutants, acid rain and chemical properties of soil on water deficit in pitch pine were also investiaged. Water content of needles growing at polluted areas were usually lower than that at unpolluted area. Water saturation deficit of needles growing at polluted areas were usually higher than that at unpolluted area especially in dry season. These results indicated that water in needles growing at polluted areas were usually more deficient than that at unpolluted area, and were more deficient in April than other months. At polluted areas, the older the needles were, the more quickly transpirated the water in the needle was. At unpolluted areas, however, water in old needles was not so quickly transpirated as those at polluted areas. Water potential of needles of pitch pine seedlings treated with simulated acid rain (SAR) of pH 3.5 decreased more quickly than that of needles treated with SAR of pH 5.6. Loss of water through epicuticular layer was greater in the following order: magnesium deficiency+100 $\mu$M aluminium>100$\mu$M aluminium>magnesium deficiency>control. In addition to Mg deficiency and Al toxicity, growth decline of pitch pine widely occurring in polluated Seoul could to a large extent be due to cuticle degredation and abnormal vertical distribution of fine roots, which lead to water stress, particularly in dry seasons.

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Characteristics of Hydrogen-sulfide(H2S) removal by a Biofilter with Organic Materials, Peat and Rock wool (유기담체인 Peat 및 Rock wool을 사용한 바이오필터에 의한 황화수소(H2S)의 제거특성)

  • Kim, Nam-jin
    • Journal of the Korea Organic Resources Recycling Association
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    • v.9 no.3
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    • pp.136-144
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    • 2001
  • Two organic materials, peat and rock wool were used for removal of $H_2S$ by a biofilter inoculated with night soil sludge. By gradually increasing the inlet load of $H_2S$, the complete removal capacity, which was defined as the inlet load of $H_2S$ that was complete removed, and the maximum removal capacity of $H_2S$, which was the value when the removal capacity leveled off for organic materials, were estimated. Both values for Rock wool are larger than peat, based on a unit dry weight of material. By using kinetic analysis, the maximum removal rate of $H_2S$, $V_m$, and the saturation constant, $K_s$, were determined for all packing materials and the values of $V_m$ for rock wool was found to be larger. By using the kinetic parameters, the removal rates for $H_2S$ were compared both packing materials, and rock wool showed better performance for the removal of $H_2S$ in the inlet concentration range of 0~200ppm.

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Growth, Dry Matter Partitioning and Photosynthesis in North American Ginseng Seedlings

  • Proctor, John T.A.;Palmer, John W.;Follett, John M.
    • Journal of Ginseng Research
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    • v.34 no.3
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    • pp.175-182
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    • 2010
  • North American ginseng seedlings (Panax quinquefolius L.) were grown in pots in heated greenhouses, in a cool greenhouse, or in the field, in 11 experiments at various times over 16 years. Crop establishment, dry matter partitioning, photosynthesis, radiation use efficiency and carbon budget were measured and/or calculated in some years. Once the seedling canopy, of about $20\;cm^2$ per seedling, and a leaf area index of 0.37, was established, about 40 days after germination, full canopy display lasted about 87 days. Only 16.6% of the incoming solar radiation was intercepted by the crop, the remainder falling on the mulched soil surface. Total and root dry matter accumulations in the cool greenhouse and in the field were about double that in the heated greenhouses. Partitioning of dry matter to roots (economic yield or harvest index) in the cool greenhouse and in the field was 73% whereas it was 62.5% in the heated greenhouses. The relationship between root dry matter and radiation interception during the full canopy period was linear with growth efficiencies of $2.92\;mg\;MJ^{-1}$ at 4.8% of incoming radiation and $0.30\;mg\;MJ^{-1}$ at 68% of incoming radiation. A photosynthetic rate of $0.39\;g\;m^{-2}\;h^{-1}$ was attained at light saturation of about $150\;{\mu}mol\;m^{-2}\;s^{-1}$ (7.5% of full sunlight); dark respiration was $0.03\;g\;m^{-2}\;h^{-1}$, about 8.5% of maximum assimilation rate. Estimates of dry matter accumulation by growth analysis and by $CO_2$ uptake were similar, 6.21 vs. 7.62 mg $CO_2$, despite several assumptions in $CO_2$ uptake calculations.

3-D Slope Stability Analysis on Influence of Groundwater Level Changes in Oksan Landslide Area (지하수위 변화에 따른 옥산 산사태 지역의 3차원 사면안정성 해석)

  • Seo, Yong-Seok;Kim, Sung-Kwon;Lee, Kyoung-Mi
    • The Journal of Engineering Geology
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    • v.18 no.2
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    • pp.177-183
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    • 2008
  • In the study, we carried out a 3-D analysis to assess the influence of groundwater level changes on the slope stability, conducting a series of back-numerical analysis to delineate the critical line of the shear strength of the failure surface of a landslide, and a laboratory test to determine the geo-mechanical properties of soil samples. The analysis result shows that the shear strength determined by the laboratory test was distributed below the critical line of shear strength estimated by back-analysis. Differences between driving and resisting force were also analyzed in groundwater conditions of dry and saturation. It appeared that the stress gets greater towards the slope center of the landslide, and the debris mass moves downwards. According to the analysis, the factor of safety becomes 1 with the rise of foundwater level up to -0.85 m from the slope surface, while the slope tends to stay stable during dry seasons.

Purification and Characterization of Antifungal Chitinase from Pseudomonas sp. YHS-A2

  • Lee, Han-Seung;Lee, Hyun-Jung;Choi, Sung-Won;Her, Song;Oh, Doo-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.7 no.2
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    • pp.107-113
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    • 1997
  • A strain producing a high amount of chitinase was isolated from soil, identified as Pseudomonas sp., and tentatively named Pseudomonas sp. YHS-A2. An extracellular chitinase of Pseudomonas sp. YHS-A2 was purified according to the procedure of ammonium sulfate saturation, affinity adsorption, Sephadex G-100 gel filtration and Phenyl-sepharose CL-4B hydrophobic interaction column chromatography. The molecular weight of the purified enzyme was estimated to be 55 kDa on SDS-PAGE was confirmed by active staining. Optimal pH and temperature of the enzyme are pH 7.0 and $50^{\circ}C$, respectively, and the enzyme is stable between pH 5.0 and 8.0 and below $50^{\circ}C$. The main products of colloidal chitin by the chitinase were N-acetyl-D-glucosamine and N,N'-diacetylchitobiose both of which were detected by HPLC analysis. The enzyme is supposed to be a random-type endochitinase which can degrade any position of ${\beta}$-l,4-linkages of chitin and chitooligosaccharides. The chitinase inhibited the growth of some phytopathogenic fungi, Fusarium oxysporum, Botrytis cineria, and Mucor rouxii and these antifungal effects were thought to be due to the characteristics of endochitinase.

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