• Title/Summary/Keyword: Effects of Characteristics

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Environmental effects from Natural Waters Contaminated with Acid Mine Drainage in the Abandoned Backun Mine Area (백운 폐광산의 방치된 폐석으로 인한 주변 수계의 환경적 영향)

  • 전서령;정재일;김대현
    • Economic and Environmental Geology
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    • v.35 no.4
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    • pp.325-337
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    • 2002
  • We examined the contamination of stream water and stream sediments by heavy metal elements with respect to distance from the abandoned Backun Au-Ag-Cu mine. High contents of heavy metals (Pb, Zn, Cu, Cd, Mn, and Fe) and aluminum in the waters connected with mining and associated deposits (dumps, tailings) reduce water quality. In the mining area, Ca and SO$_4$ are predominant cation and anion. The mining water is Ca-SO$_4$ type and is enriched in heavy metals resulted from the weathering of sulfide minerals. This mine drainage water is weakly acid or neutral (pH; 6.5-7.1) because of neutralizing effect by other alkali and alkaline earth elements. The effluent from the mine adit is also weakly acid or neutral, and contains elevated concentrations of most elements due to reactions with ore and gangue minerals in the deposit. The concentration of ions in the Backun mining water is high in the mine adit drainage water and steeply decreased award to down stream. Buffering process can be reasonably considered as a partial natural control of pollution, since the ion concentration becomes lower and the pH value becomes neutralized. In order to evaluate mobility and bioavailability of metals, sequential extraction was used for stream sediments into five operationally defined groups: exchangeable, bound to carbonates, bound to FeMn oxide, bound to organic matter, and residual. The residual fraction was the most abundant pool for Cu(2l-92%), Zn(28-89%) and Pb(23-94%). Almost sediments are low concentrated with Cd(2.7-52.8 mg/kg) than any other elements. But Cd dominate with non stable fraction (68-97%). Upper stream sediments are contaminated with Pb, and down area sediments are enriched with Zn. It is indicate high mobility of Zn and Cd.

Geochemical Studies of the Trace Element of the Basalt in the Kilauea, Hawaii (킬라우에아 현무암의 미량원소에 대한 지구화학적 연구)

  • Park, Byeong-Jun;Jang, Yun-Deuk;Kwon, Suk-Bom;Kim, Jeong-Jin
    • Economic and Environmental Geology
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    • v.40 no.5
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    • pp.675-689
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    • 2007
  • Kilauea volcano's summit area was formed by continuous ind/or sporadic eruption activities for several hundreds years. In this study, we mainly focused on the trace elements characteristics through systematic sample rocks erupted from 1790 to September of 1982. Under the microscope it can be observed some main minerals such as olivine, clinopyroxene. and plagioclase with minor opaque minerals including Cr-spinel and ilmenite. Zr, V, Y, Ti elements show incompatible activities with MgO while Ni, Cr, Co elements show highly compatible properties. Elements like as Ba, Rb, Th, Sr, Nd are highly incompatible to show positive trends with $K_2O$. In the REE diagram LREE is more enriched than HREE suggesting typical Oceanic Island Basalt(OIB) type. It can be suggested that Sr have an effect on the fractionation of plagioclase from the kink in the $K_2O$ variation diagram. Y/Ho ratio diagram shows there was no fluids effect in the historical Kilauea volcano but Zr/Hf ratio diagram shows a significant difference between Kilauea lavas and PuuOo lavas. There are distinctive changes of trace element contents showing in particular abrupt changes of temporal variations between 1924 and 1954. Moreover, PuuOo lavas which had been erupted since 1983 follow these decreasing trends of trace element variation. Therefore, it is strongly suggested that these abrupt changes of trace elements trends result from the huge collapse geological event which formed Halemaumau crater in 1924 causing contamination effects of crustal contents into magma chamber and from the changes of parental magma composition injected into Kilauea volcano's summit magma reservoir.

The Solvent Extraction of Univalent Cation Picrates by New Podands (새로운 포단드에 의한 피크린산 일가 양이온 염의 용매추출)

  • Jung, Jong Hwa;Cho, Sung Bae;Kim, Jineun;Kim, Jae Sang;Lee, Shim Sung
    • Analytical Science and Technology
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    • v.6 no.1
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    • pp.29-37
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    • 1993
  • Some new podands containing phenyl(B), benzyl(Bz), pyridine(Py), quinoline(Q) and naphthalene(Np) as end-groups, and oxygen(O) and sulfur(S) in ether chains as donor atoms have been synthesized. The univalent cation binding characteristics of these podands have been studied by NMR titration and solvent extraction. By NMR titration we have found that the most of podands form 1:1 complexes with $Ag^+$ ion. Especially, the substituted sulfur atoms in ether chains show the effects to enhance the stabilities. We also carried out the extractions of univalent cation picrates including alkaline metal, $Ag^+$, $Tl^+$ and $NH_4{^-}$ ions from aqueous to chloroform layer by using these podands. We found that the extractabilities of $Ag^+$ ion with the quinoline-containing podands such as, $Q_2O_4$, $Q_2O_5$ and $BQO_5$ were 86.8, 86.6 and 48.0% respectively, but the naphthalene-containing podands such as, $Np_2O_4$ and $Np_2O_5$ extracted quite small amount. Otherwise, in cases of $Bz_2O_3S_2$(89.4%), $B_2O_2S_2$(96.8%), $B_2O_3S_2$(58.9%), $Py_2O_2S_2$(58.8%), $Py_2O_3S_2$(42.1%), and $B_2O_4S$(15.0%), interestingly, $Bz_2O_3S_2$ which have sulfur atoms and benzyl groups showed the highest extraction selectivity for $Ag^+$ ion. This result seems due to not only the strong interaction of $Ag^+$ ion with sulfur donors according to the HSAB theory, but also the effective ${\pi}-{\pi}$ stacking interaction between two aromatic end-groups which is enhanced by the flexible methylene spacing group in benzyl groups instead of phenyl groups. The extraction coefficients gave the similar tendency as the extractabilities and the stabilities. From these results, it could be concluded that the predominant factor affected to extraction coefficients is the stabilities, which are strongly influenced by the structures of podands.

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Dosimetric Characteristics of Dual Photon Energy Using Independent Collimator Jaws (고에너지 선형가속기의 Independent Collimator를 이용한 비대칭 방사선 조사시 방사선량 결정에 미치는 요인에 관한 연구)

  • Kim Jeung-kee;Choi Young-Min;Lee Hyung-Sik;Hur Won-Joo
    • Radiation Oncology Journal
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    • v.14 no.3
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    • pp.237-244
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    • 1996
  • Purpose : The accurate dosimetry of independent collimator equipped for 6MV and 15MV X-ray beam was investigated to search for the optimal correction factor. Materials and Methods : The field size factors, beam quality and dose distribution were measured by using 6MV, 15MV X-ray Field size factors were measured from $3{\times}3cm^2$ to $35{\times}35cm^2$ by using 0.6cc ion chamber (NE 2571) at Dmax. Beam qualities were measured at different field sizes, off-axis distances and depths. Isodose distributions at different off-axis distance using $10\times10cm^2$ field were also investigated and compared with symmetric field. Result: 1) Relative field size factors was different along lateral distance with maximum changes in $3.1\%$ for 6MV and $5\%$ for 15MV. But the field size factors of asymmetric fields were identical to the modified central-axis values in symmetric field, which corrected by off-axis ratio at Dmax. 2) The HVL and PDD was decreased by increasing off-axis distance. PDD was also decreased by increasing depth For field size more than $5{\times}cm^2$ and depth less than 15cm, PDD of asymmetric field differs from that of symmetric one ($0.5\~2\%$ for 6MV and $0.4\~1.4\%$ for 15MV). 3) The measured isodose curves demonstrate divergence effects and reduced doses adjacent to the edge close to the flattening filter center was also observed. Conclusion . When asymmetric collimator is used, calculation of MU must be corrected with off-axis and PDD with a caution of underdose in central axis.

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Effects of Light, Temperature, Water Changes on Physiological Responses of Kalopanax pictus Leaves(I) - Characteristics of Photosynthesis and Respiration of Leaves by the Light Intensity - (광, 온도, 수분 변화에 따른 음나무 엽의 생리반응(I) - 광도변화에 따른 광합성과 호흡 특성 -)

  • Han, Sang-Sup;Jeon, Doo-Sik;Sim, Joo-Suk
    • Journal of Forest and Environmental Science
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    • v.21 no.1
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    • pp.83-91
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    • 2005
  • This research was carried out to elucidate the photosnthesis, respiration, and intercellullar $CO_2$ concentration of Kalopanax pictus leaves. The results obtained are summarized as follows; 1. The light compensation points in leaves of Kalopanax pictus seedlings were in the following order; the upper ($34{\mu}mol\;m^{-2}s^{-1}$) middle ($29{\mu}mol\;m^{-2}s^{-1}$) lower leaves ($24{\mu}mol\;m^{-2}s^{-1}$). The light saturated points were at $800{\sim}1200{\mu}mol\;m^{-2}s^{-1}$ in the upper leaves and $400{\mu}mol\;m^{-2}s^{-1}$ in the middle and lower leaves. At the light saturated points, the net photosynthesis rate was in the following order; the upper ($11.1{\mu}mol\;CO_2\;m^{-2}s^{-1}$) middle ($5.15{\mu}mol\;CO_2\;m^{-2}s^{-1}$) lower leaves ($4.01{\mu}mol\;CO_2\;m^{-2}s^{-1}$). The light use efficiency was in the following order; the upper ($0.041{\mu}mol\;CO_2\;{\mu}mol^{-1}$) middle ($0.040{\mu}mol\;CO_2\;{\mu}mol^{-1}$) lower leaves ($0.039{\mu}mol\;CO_2\;{\mu}mol^{-1}$). 2. In the upper leaves of Kalopanax pictus seedlings, the stomatal conductance increased continuously with increasing light intensity. In the middle and lower leaves, it was saturated at $400{\mu}mol\;m^{-2}s^{-1}$. 3. In the upper, middle and lower leaves of Kalopanax pictus seedlings, the intercellular $CO_2$ concentration/the atmospheric $CO_2$ concentration ($C_i/C_a$) ratio rapidly decreased to $600{\mu}mol\;m^{-2}s^{-1}$, and then showed a constant values. 4. In the upper leaves of Kalopanax pictus seedlings, the photorespiration rate was $3.34{\mu}mol\;CO_2\;m^{-2}s^{-1}$ and $CO_2$ compensation point was $48.7{\mu}mol\;mol^{-1}$. Dark respiration rate increased exponentially with increasing leaf temperature, and the photorespiration rate was 2.4 times higher than dark respiration rate.

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Photosynthetic and Growth Responses of Chinese Cabbage to Rising Atmospheric CO2 (대기 중 CO2 농도의 상승에 대한 배추의 광합성과 생장 반응)

  • Oh, Soonja;Son, In-Chang;Wi, Seung Hwan;Song, Eun Young;Koh, Seok Chan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.357-365
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    • 2016
  • The effects of elevated atmospheric $CO_2$ on photosynthesis and growth of Chinese cabbage (Brassica campestris subsp. napus var. pekinensis) were investigated to predict productivity in highland cropping in an environment where $CO_2$ levels are increasing. Vegetative growth, based on fresh weight of the aerial part, and leaf characteristics (number, area, length, and width) of Chinese cabbage grown for 5 weeks, increased significantly under elevated $CO_2$ ($800{\mu}mol{\cdot}mol^{-1}$) compared to ambient $CO_2$ ($400{\mu}mol{\cdot}mol^{-1}$). The photosynthetic rate (A), stomatal conductance ($g_s$), and water use efficiency (WUE) increased, although the transpiration rate (E) decreased, under elevated atmospheric $CO_2$. The photosynthetic light-response parameters, the maximum photosynthetic rate ($A_{max}$) and apparent quantum yield (${\varphi}$), were higher at elevated $CO_2$ than at ambient $CO_2$, while the light compensation point ($Q_{comp}$) was lower at elevated $CO_2$. In particular, the maximum photosynthetic rate ($A_{max}$) was higher at elevated $CO_2$ by 2.2-fold than at ambient $CO_2$. However, the photosynthetic $CO_2$-response parameters such as light respiration rate ($R_p$), maximum Rubisco carboxylation efficiency ($V_{cmax}$), and $CO_2$ compensation point (CCP) were less responsive to elevated $CO_2$ relative to the light-response parameters. The photochemical efficiency parameters ($F_v/F_m$, $F_v/F_o$) of PSII were not significantly affected by elevated $CO_2$, suggesting that elevated atmospheric $CO_2$ will not reduce the photosynthetic efficiency of Chinese cabbage in highland cropping. The optimal temperature for photosynthesis shifted significantly by about $2^{\circ}C$ under elevated $CO_2$. Above the optimal temperature, the photosynthetic rate (A) decreased and the dark respiration rate ($R_d$) increased as the temperature increased. These findings indicate that future increases in $CO_2$ will favor the growth of Chinese cabbage on highland cropping, and its productivity will increase due to the increase in photosynthetic affinity for light rather than $CO_2$.

Behaviors of Arsenic in Paddy Soils and Effects of Absorbed Arsenic on Physiological and Ecological Characteristics of Rice Plant lll. Effect of Water Management on As Uptake and the Growth of Rice Plant at As Added Soil (토양중(土壤中) 비소(砒素)의 행동(行動)과 수도(水稻)의 비소흡수(砒素吸收)에 의(依)한 피해생리(被害生理) 생태(生態)에 관(關)한 연구(硏究);Ⅲ.물관리(管理)가 수도의 비소흡수(砒素吸收) 및 생육(生育)에 미치는 영향(影響))

  • Lee, Min-Hyo;Lim, Soo-Kill-H
    • Korean Journal of Environmental Agriculture
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    • v.6 no.1
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    • pp.1-6
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    • 1987
  • A pot experiment was conducted to find out the effect of water management on the growth and uptake of arsenic and inorganic nutrients of rice plant at As added soil. The arsenic were added to soil at the levels of As 0, 10, 50, 100 and 150 ppm, respectively. Water management was done with two ways: intermittent irrigation from ten days after transplanting, and continuous submersion until harvest. Higher soil As levels increased As content in plant but reduced growth rate. Aresenic content in plant was considerably reduced with intermittent irrigation compared to continuous submersion. Rice growth showed also same trend. With increasing As levels in soil, N content in plant was increased but P, K, Ca, Mg, $SiO_2$, Fe and Mn content in plant were tend to be decreased. These inorganic nutrients in plant were also much absorbed in continuous submersion compared to intermittent irrigation. Soil pH was slightly increased with increasing As levels in soil while soil Eh has no relationship with soil As levels. On the other hand, soil pH was higher in the treatment of continuous submersion than that of intermittent irrigation but soil Eh showed reverse trend. With increasing As levels in soil, water soluble-As and Ca-As fractions in soil tend to be increased with continuous submersion, but these fractions has no tendency with intermittant irrigation.

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Effect of Cooling in a Semi-closed Greenhouse at High Temperature on the Growth and Photosynthesis Characteristics in Paprika (고온기 반밀폐형온실 냉방이 파프리카 생육과 광합성 특성에 미치는 영향)

  • Kim, Eun Ji;Park, Kyoung Sub;Goo, Hei Woong;Park, Ga Eun;Myung, Dong Ju;Jeon, Yong Hwan;Na, Haeyeong
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.335-341
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    • 2021
  • In this study, experiments were conducted to investigate the effects of high- temperature stress on paprika in a semi-closed greenhouse where cooling is available and a normal plastic greenhouse. Paprika grown in a semi-closed greenhouse in which geothermal cooling is provided showed a significantly higher speed of photosynthesis than paprika grown in a 3-layer plastic greenhouse in which there is no cooling system. It suggests that the photosynthesis speed of paprika in a plastic house decreases owing to high temperature stress. Plant height increased by 13cm more in the semi-closed greenhouse, and the size of leaf showed similar growth speed until the 2nd week after transplanting, however, after 3 weeks, the semi-closed greenhouse showed a big difference by 47% compared with the plastic greenhouse. In terms of the fruit count, the semi-closed greenhouse had 10.6 fruits/plant and the plastic greenhouse had 4.6 fruits/plant, indicating that the semi-closed greenhouse had a higher number of fruits by 130% than the plastic greenhouse. The fruit weight also presented a difference between the semi-closed greenhouse and the plastic greenhouse by 46%, which is 566.7g/plant and 387g/plant, respectively. According to the above mentioned results, it was validated that when paprika is cultivated in a semi-closed greenhouse where a cooling system is applied, photosynthesis and growth were better than in the normal plastic greenhouse. Thus, if the hot summer season is overcome by applying the elemental technologies for the cooling system to the normal plastic greenhouse, farm income may increase through improvement in the yield and quality.

Seismic wave propagation through surface basalts - implications for coal seismic surveys (지표 현무암을 통해 전파하는 탄성파의 거동 - 석탄 탄성파탐사에 적용)

  • Sun, Weijia;Zhou, Binzhong;Hatherly, Peter;Fu, Li-Yun
    • Geophysics and Geophysical Exploration
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    • v.13 no.1
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    • pp.1-8
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    • 2010
  • Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness, lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that: 1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.

Association between breakfast and lifestyle, interest in beauty care, and attitude toward breakfast in high school girls in Incheon (여고생의 아침식사와 라이프스타일, 외모 가꾸기 관심도 및 아침식사관련 태도의 관련성)

  • Lee, Seolmi;Kim, Mi-Hyun
    • Journal of Nutrition and Health
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    • v.53 no.3
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    • pp.288-302
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    • 2020
  • Purpose: This study examined the factors related to skipping breakfast in high school girls. Methods: A survey of a total of 581 high school girls residing in Incheon was conducted. The subjects were classified into 2 groups according to the breakfast frequency: "breakfast skipping" group (eating breakfast ≤ 2 times/week, n = 250) and "breakfast eating" group (eating breakfast ≥ 3 times/week, n = 331). This study compared the general characteristics, lifestyles, interest in weight control and beauty care, food habits, the reasons and symptoms of skipping breakfast, as well as the attitude toward breakfast between the 2 groups. Results: The mean age of the subjects was 16.5 years old. Approximately, 33.9%, 33.6%, and 32.5% of the subjects were in first grade, second grade, and third grade, respectively, with no significant difference between the 2 groups. The breakfast skipping group showed a high interest in weight control, and beauty care than the breakfast eating group. The breakfast skipping group consumed more afternoon snacks and late-night snacks, and ate dinner irregularly. Although the breakfast skipping group experienced the negative effects of skipping breakfast, they showed low recognition for the importance or role of breakfast. The most common reason for skipping breakfast was lack of time, which appears to be related to the late wake-up time and the time spent on make-up or beauty-care. Conclusion: Skipping breakfast by high school girls was related to a high interest in beauty care, irregular meals and low attitude toward the importance of breakfast for health and nutrition. Therefore, it is necessary to conduct nutrition education to change the perceptions and attitudes of female adolescents regarding the importance of breakfast by recognizing that breakfast can affect not only balanced nutrition and health, but also healthy physical beauty.