• Title/Summary/Keyword: higher order elements

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Physiological and Ecological Studies on the Low Temperature Damages of Rice (Oryza sativia L.) (수도의 저온장해에 관한 생리 생태학적 연구)

  • 오윤진
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.26 no.1
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    • pp.1-31
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    • 1981
  • Experiments were conducted to investigate rice varietal response to low water and air temperatures at different growth stages from 1975 to 1980 in a phytotron in Suweon and in a cold water nursery in Chooncheon. Germination ability, seedling growth, sterility of laspikelets, panicle exertion, discoloration of leaves, and delay of heading of recently developed indica/japonica cross(I/J), japonica, and indica varieties at low air temperature or cold water were compared to those at normal temperature or natural conditions. The results are summarized as follows: 1. Practically acceptable germination rate of 70% was obtained in 10 days after initiation of germination test at 15\circ_C for japonica varieties, but 15 days for IxJ varieties. Varietal differences in germination ability at suboptimal temperature was greatest at 16\circ_C for 6 days. 2. Cold injury of rice seedlings was most severe at the 3.0-and 3.5-leaf stage and it was reduced as growth stage advanced. A significant positive correlation was observed between cold injury at 3-leaf stage and 6-leaf stage. 3. At day/night temperatures of 15/10\circ_C seedlings of both japonica and I/J varieties were dead in 42 days. At 20/15\circ_C japonica varieties produced tillers actively, but tillering of I/J varieties was retarded a little. At 25/15\circ_C, both japonica and I/J varieties produced tillers most actively. Increase in plant height was proportional to the increase in all varieties. 4. In I/J varieties the number of differentiated panicle rachis branches and spikelets was reduced at a day-night temperature of 20-15\circ_C compared to 25-20 or 30-25\circ_C, but not in japonica varieties although panicle exertion was retarded at 20-15\circ_C. The number of spikelets was not correlated with the number of primary rachis branches, but positively correlated with that of secondary rachis branches. 5. Heading of rice varieties treated with 15\circ_C air temperature at meiotic stage was delayed compared to that at tillering stage by 1-3 days and heading was delayed as duration of low temperature treatment increased. 6. At cold water treatment of 17\circ_C from tillering to heading stage, heading of japonica, I/J, and cold tolerant indica varieties was delayed 2-6, 3-9, and 4-5 days, respectively, Growth stage sensitive to delay of heading delay at water treatment were tillering stage, meiotic stage, and booting tage in that order, delay of heading was greater in indica corssed japonica(Suweon 264), japonica(Suweon 235), and cold tolerant indica(Lengkwang) varieties in that order. Delay of heading due to cold water treatment was positively correlated with culm length reduction and spikelet sterility. 7. Elongation of culms and exertion of panicles of rice varieties treated with low air temperature 17\circ_C. Culm length reduction rate of tall varieties was lower than that of short statured varieties at low temperature. Panicle exertion was most severaly retarded with low temperature treatment at heading stage. Generally, retardation of panicle exertion of 1/1 varieties was more severe than that of japonica varieties at low temperature. There was a positive correlation between panicle exertion and culm length at low temperature. 8. The number of panicles was increased with cold water treatment at tillering stage, but reduced at meiotic stage. As time of cold water treatment was conducted at earlier growth stage, culm length was shorter and panicle exertion poorer. 9. Sterility of all rice varieties was negligible at 17\circ_C for three days but 30.3-85.2% of strility was observed for nine-day treatment at 17\circ_C. Among the tested varieties, sterility of Suweon 264 and Milyang 42 was highest and that of Suweon 290 and Suweon 287 was lowest. The most sensitive growth stage to low temperature induced sterility was from 15 to 5 days before heading. There was positive correlation between sterility of rice plants treated with low temperature at meiotic and heading stage. 10. Percentage of spikelet sterility was greatest at cold water treatment at meiotic stage (auricle distance -15~-10cm) and it was higher in 1/1 (Suweon 264, Joseng tongil), japonica (Nongbaek, Towada), and cold tolerance indica(Lengkwang) varieties in the order. Level of cold water and position of young-ear affected on the sterility of varieties at meiotic stage; percentage of spikelet sterility of variety, Lengkwang, of which young-ear was located above the cold water level was high, but that of short statured variety, Suweon 264, of which young-ear was located in the cold water was lower. 11. Percentage of ripened grains was not reducted at 15\circ_C air temperature for three days at full heading stage in all varieties. However, at six-day low temperature treatment Suweon 287, Suweon 264 showed percentage of ripended grains lower than 60%, but at nine-day low temperature treatment all varieties showed percentage of ripened grains lower than 60%. Low temperature treatment of 17\circ_C from 10 days after heading for 20 days did not affect on the ripening of all varieties. 12. Uptake of nitrogen, phosphorous, potassium, calcium, and magnesium in whole plants was higher at average air temperature of 25\circ_C, but concentration of the elements was lower compared to those at 19\circ_C. However, both total uptake and concentration of manganese were higher at 19\circ_C compared to 25\circ_C. 13. Higher application of nitrogen, phosphorus, silicate, and compost increased yield of rice due to increased number of panicles and spike let fertility in cold water irrigated paddy.

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A Study on Root Damage to Street Pavement from the Roots of Roadside Trees in Urban Areas - Focusing on Roadside Trees in Seo-gu, Daejeon City - (도심 가로수 뿌리의 융기특성 연구 - 대전 서구 가로수를 대상으로 -)

  • Tak, Seong-Cheol;Lee, Shiyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.3
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    • pp.58-69
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    • 2018
  • This study investigated root damage characteristics and correlations between roadside trees and street furniture through the investigation of the root damage conditions and the current status of roadside trees and street furniture in Seo-gu, Daejeon City where the occurrence of pavement uplift is frequent. The study area was divided into six areas by species of trees as Metasequoia glyptostroboides and Platanus occidentalis focusing on the streets that were installed with trees chest height and 8cm round planted at the time of the development of the Dunsan-dong Housing Site Development in Seo-gu, Daejeon metropolitan city (1990~1994). The damage rate of roadside protection frames (95.3%) was higher than that of curbstones (19.7%) at the study site. Streets without a protective frame were more likely to have damaged pavement. In addition, the frequency of breakage of protective frames was lowered when a drinking water area was increased to more than a certain level. The frequency of the type of uplift in the sidewalk pavement surfaces is in the order of tail type > mounding type > irregular type, and the frequency of the uplift direction is the highest in Direction 1 ($0{\sim}44^{\circ}C$), Direction 2 ($45{\sim}89^{\circ}$), and Direction 3 ($95{\sim}134^{\circ}$) when $180^{\circ}$ of the street direction is based on $90^{\circ}$ parallel to the curbstone. The uplift length is about 31~60cm and it is most often at a height of 3~6cm. When comparing the results of uplift deformation, Metasequoia glyptostroboides was found to be higher than the deformation of Platanus occidentalis. In addition, it can be seen that the larger the length, width and height of the ridge, the larger the deformation becomes. The relationship between the diameter at breast height, the dimension of the pavement width, the frequency of the ridge phenomenon and the deformation amount is not necessarily proportional, and there seems to be a gap due to external factors such as soil humidity and planting base. Therefore there is a need for a multi-directional approach in reducing uplift.

A study on Airborne Concentration of Welding Fumes and Metals in Confined Spaces of a Shipyard (모조선소의 밀폐된 작업장에서의 공기중 용접흄 및 중금속 농도에 관한 조사 연구)

  • Kwag, Young-Soon;Paik, Nam-Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.7 no.1
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    • pp.113-131
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    • 1997
  • This study was performed to evaluate the exposure levels of worker exposed to welding fume and metals in confined spaces of a shipyard. The airborne concentration of welding fumes and metal elements in confined spaces were compared with those in open working areas. Results of the study were as follows. 1. The geometric mean of welding fume concentration in a confined space was $16.6mg/m^3$, which contained $3.9mg/m^3$ Fe, $1.2mg/m^3$ Mg, $0.8mg/m^3$ Zn, $0.008mg/m^3$ Cu, $0.008mg/m^3$ Pb, $0.005mg/m^3$ Ni, $0.003mg/m^3$ Cr, $0.003mg/m^3$ Cd. The geometric mean of welding fume concentration in open working areas was $5.2mg/m^3$, which contained $1.1mg/m^3$ Fe, $0.3mg/m^3$ Mg, $0.3mg/m^3$ Zn, $0.004mg/m^3$ Cu, $0.008mg/m^3$ Pb, $0.005mg/m^3$ Ni, $0.003mg/m^3$ Cr, $0.0003mg/m^3$ Cd. The geometric mean of welding fume concentration in confined spaces was 3,2 times higher than that in open working areas. The geometric mean concentrations of such metals as Fe, Mg, Zn, or Cu within fume in confined spaces were 2-4 times higher than those in open working areas, while little difference made such metals as Pb, Ni, Cr, Cd. 2. In 32 samples out of a total of 39 samples (82.1%) collected in confined spaces, the concentrations of welding fume exceeded TLV. while so did 19 samples out of 33 samples (57.6%) in open working areas. As for the concentrations of metals in welding flume from confined spaces, Fe exceeded TLV in 14 out of a total of 38 samples (36.8%), Mn exceeded TLV in 23 out of a total of 38 samples (60.5%). As for the concentration of metals in welding fume from open working areas, Fe exceeded TLV in 3 out of a total of 34 samples (8.8%), Mn exceeded TLV in 6 out of a total of 34 samples (17.6%). Considering additive effect among metals, in 31 out of a total of 39 samples (79.5%) collected in confined spaces, the concentrations of welding fume exceeded TLV, while so did 14 out of 38 samples (55.6%) in open working areas. 3. In respect of base metal and welding type the concentration of total welding fume by $CO_2$ gas W./mild steel was the highest, followed by semiauto MMA/mild steel, then followed by TIG or $CO_2$ gas W./stainless steel. ; as for concentration of metal within fume, a decreasing order was Fe, Zn, Mn, and Pb in $CO_2$ gas W./mild steel and semiauto MMA/mild steel, but Fe, Mn, Cr, and Ni in TIG or $CO_2$ gas W./stainless steel. 4. In case of welding base metal covered by paint, contents of Zn within red paint chip and within gray paint chip were 14.0% and 0.08% respectively, which showed a little difference, while the airborne concentrations of Zn within fume during welding base metal covered red paint and gray paint were $1.351mg/m^3$ and $1.018mg/m^3$ respectively, which showed little difference. As for Pb, contents of red paint chip and gray paint chip were 0.14% and 0.08% respectively, and the airborne concentrations within fume during welding base metal covered red paint and gray paint were $0.009mg/m^3$ and $0.007mg/m^3$ respectively, both of which showed little difference.

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Wet Deposition of Heavy Metals during Farming Season in Taean, Korea (태안지역 강우의 중금속 함량 평가)

  • Jung, Goo-Bok;Kim, Min-Kyeong;Lee, Jong-Sik;Kim, Won-Il;Kim, Gun-Yeob;Ko, Byong-Gu;Kang, Kee-Kyung;Kwon, Soon-Ik
    • Korean Journal of Environmental Agriculture
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    • v.30 no.2
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    • pp.153-159
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    • 2011
  • BACKGROUND: This experiment was conducted to investigate the distribution and burden characteristics of heavy metal in the rainwater sampled at Taean area, in the middle part of Korea, from April 2002 to October 2003. METHODS AND RESULTS: The relationship between concentration of heavy metal and other chemical properties in the rainwaters was also evaluated. Chemical properties in the rainwater were various differences with raining periods and years. It appeared that a weighted average pH values of rainwater was ranged from 5.0 to 5.1. Heavy metal concentrations in the rainwater were ranked as Pb > Zn > Cu > Ni > As > Cr > Cd. As compared with heavy metal concentrations of rainwater in 2002, Cu, Pb, and Zn were higher than other elements in 2003. There were positive correlation between major ionic components, such as ${NH_4}^+$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Na^+$, ${SO_4}^{2-}$ and ${NO_3}^-$, and As, Cd, Zn, Cr, and Ni concentrations in rainwater. For heavy metal distribution of rainwater, the order of average enrichment factor was Cd > Pb > As > Cu > Zn > Ni > Cr, and these were relatively higher than the natural components such as Fe, Mg and Ca. The monthly enrichment factor were relatively high, from August to October at Taean. The monthly amount of heavy metal precipitation was high in the rainy season from July to August because of great influence of rainfall. CONCLUSION(s): The results of this study suggest that the heavy metals(Cd, Pb, As, Cu, and Zn) of rainwater is strongly influenced by anthropogenic sources rather than natural sources.

WHICH INFORMATION MOVES PRICES: EVIDENCE FROM DAYS WITH DIVIDEND AND EARNINGS ANNOUNCEMENTS AND INSIDER TRADING

  • Kim, Chan-Wung;Lee, Jae-Ha
    • The Korean Journal of Financial Studies
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    • v.3 no.1
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    • pp.233-265
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    • 1996
  • We examine the impact of public and private information on price movements using the thirty DJIA stocks and twenty-one NASDAQ stocks. We find that the standard deviation of daily returns on information days (dividend announcement, earnings announcement, insider purchase, or insider sale) is much higher than on no-information days. Both public information matters at the NYSE, probably due to masked identification of insiders. Earnings announcement has the greatest impact for both DJIA and NASDAQ stocks, and there is some evidence of positive impact of insider asle on return volatility of NASDAQ stocks. There has been considerable debate, e.g., French and Roll (1986), over whether market volatility is due to public information or private information-the latter gathered through costly search and only revealed through trading. Public information is composed of (1) marketwide public information such as regularly scheduled federal economic announcements (e.g., employment, GNP, leading indicators) and (2) company-specific public information such as dividend and earnings announcements. Policy makers and corporate insiders have a better access to marketwide private information (e.g., a new monetary policy decision made in the Federal Reserve Board meeting) and company-specific private information, respectively, compated to the general public. Ederington and Lee (1993) show that marketwide public information accounts for most of the observed volatility patterns in interest rate and foreign exchange futures markets. Company-specific public information is explored by Patell and Wolfson (1984) and Jennings and Starks (1985). They show that dividend and earnings announcements induce higher than normal volatility in equity prices. Kyle (1985), Admati and Pfleiderer (1988), Barclay, Litzenberger and Warner (1990), Foster and Viswanathan (1990), Back (1992), and Barclay and Warner (1993) show that the private information help by informed traders and revealed through trading influences market volatility. Cornell and Sirri (1992)' and Meulbroek (1992) investigate the actual insider trading activities in a tender offer case and the prosecuted illegal trading cased, respectively. This paper examines the aggregate and individual impact of marketwide information, company-specific public information, and company-specific private information on equity prices. Specifically, we use the thirty common stocks in the Dow Jones Industrial Average (DJIA) and twenty one National Association of Securities Dealers Automated Quotations (NASDAQ) common stocks to examine how their prices react to information. Marketwide information (public and private) is estimated by the movement in the Standard and Poors (S & P) 500 Index price for the DJIA stocks and the movement in the NASDAQ Composite Index price for the NASDAQ stocks. Divedend and earnings announcements are used as a subset of company-specific public information. The trading activity of corporate insiders (major corporate officers, members of the board of directors, and owners of at least 10 percent of any equity class) with an access to private information can be cannot legally trade on private information. Therefore, most insider transactions are not necessarily based on private information. Nevertheless, we hypothesize that market participants observe how insiders trade in order to infer any information that they cannot possess because insiders tend to buy (sell) when they have good (bad) information about their company. For example, Damodaran and Liu (1993) show that insiders of real estate investment trusts buy (sell) after they receive favorable (unfavorable) appraisal news before the information in these appraisals is released to the public. Price discovery in a competitive multiple-dealership market (NASDAQ) would be different from that in a monopolistic specialist system (NYSE). Consequently, we hypothesize that NASDAQ stocks are affected more by private information (or more precisely, insider trading) than the DJIA stocks. In the next section, we describe our choices of the fifty-one stocks and the public and private information set. We also discuss institutional differences between the NYSE and the NASDAQ market. In Section II, we examine the implications of public and private information for the volatility of daily returns of each stock. In Section III, we turn to the question of the relative importance of individual elements of our information set. Further analysis of the five DJIA stocks and the four NASDAQ stocks that are most sensitive to earnings announcements is given in Section IV, and our results are summarized in Section V.

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Effect of Sludge-Fertilizer on Growth of Horticultural Plants (스럿지비료(肥料)가 원예작물(園藝作物)의 생육(生育)에 미치는 효과(效果))

  • Ku, Ja Hyeong;Kim, Tae Ill;Ahn, Joo Won;Lee, Kyu Seung;Kim, Moon Kyu
    • Korean Journal of Agricultural Science
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    • v.19 no.1
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    • pp.16-27
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    • 1992
  • To determine a potential of new sludge fertilizer for horticultural crops, comparative studies between commercial fertilizers (Jandibiryo and Wonyebokbi) and sludge fertilizer (Sludgebiryo) were made through examining the growth responses on zoysiagrass (Zoysia japponica Steud.) and several horticultural plants. 1. The pH of new sludge fertilizer remained near 6.5 regardless the particle size. The solubility of elements was highest in phosphorus, followed by nitrogen and potassium in the order. Especially, desorption of potassium was continued up to 48 hrs after solubilization. 2. There was an increase in shoot number per plant, length of stolon and rhizome, and root weight as well as clipping yield of zoysiagrass in the treatment of large size Sludgebiryo compared to small one and Jandibiryo. 3. Regardless the size of fertilizers, Sludgebiryo increased flower numbers in salvia (Salvia officinalis L. 'Hatzazz') compared to Wonyebokbi, although the difference was not great, However, leaf area and fresh weight of plant were more increased in Wonyebokbi application. 4. Flower diameter of marigold (Tagetes erecta L. 'Inca') was slightly increased in Sludgebiryo application, but the average number of lateral shoots and fresh weight per plant were significantly increased in the treatment of Wonyebokbi application. 5. Sludgebiryo effectively increased the length of both main and lateral shoots, number of flowers and weight of shoot in vinca (Vinca rosea L. 'Little Linde'), but root growth of plant was higher in Wonyebokbi application. 6, No differences between Wonyebokbi and Sludgebiryo were found in promoting the growth of leaves of perilla (Perilla frutescens Hara 'Yubsil' ), but chlorophyll content and seed weight were slightly higher in the application of Wonyebokbi compared to Sludgebiryo. In conclusion, the effectiveness of Sludgebiryo for horticultural plants was almost equal to commercial fertilizers such as Jandibiryo or Wonyebokbi. Expecially, Sludgebiryo appeared to effective on the growth of zoysiagrass, and the increase of flower size and numbers in flower crops. Results indicate that new-made Sludgebiryo can be recommended for turfgrass culture, and the flower crops in which quality depends on flower number and flower size.

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Effect of amendments and their causes of rice yield increase in ill drained paddy soil (습답(濕沓)에 대(對)한 개량제(改良劑)의 효과(效果)와 유효개량제(有效改良劑)의 수도증수원인(水稻增收原因)에 관(關)한 연구(硏究))

  • Park, Chon Suh;Song, Jae Ha;Kim, Yung Sup;Lee, Chung Young;Choh, Young Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.4 no.1
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    • pp.13-19
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    • 1971
  • In order to establish the method of improving ill drained paddy soil where the accumulation of absorption inhibitor is worried in the earlier stages of rice growth, proper soil is selected and an field experiment is designed having treatments such as lime materials, none sulfate fertilizers, boron and straw etc. The data of yield and plant analysis in different stages of rice growth is eveluated and discussed to obtain following summaries. (1) Significant yield increase was made by the treatment of lime materials such as slacked lime or wollastonite powder, materials inhibiting the activity of microorganisms such as boron and of none sulfate fertilizers lacking inhibitor producing sources. (2) The crop scientifice causes of decreasing yield are the decreasing the number of panicles per hill, grains per panicle and the weight of grains. (3) The plant nutritional causes of decreasing yield are the lowering of nitrogen content throughout the life, phosphate content since young premodia formation stage of plant and the decreased content of magnesium, calcium and silicate in straw at harvesting stage. (4) The causes of lowering the content of various elements in rice plant grown in ill drained paddy soil are suggested as root damage by producing and accumulating absorption inhibitors such as organic acids and hydrogen sulfide etc, from the following observed facts; (a) In young premodia formation stage, attaining to the maximum production and accumulation of absorption inhibitor, the phosphate accumulation in plant was smaller in the phosphate plots than without phosphate plots and much higher in the neutralized plots by adding lime materials. (b) In the plots of straw addition, the potassium content in plant at the young premodia formation stage is very low probabley due to root damage by absorption inhibitor produced from the process of straw decomposition but higher at the stage of harvesting probably due to the immetabolic negative absorption of damaged roots. (c) The effect of boron, known as the inhibitor of microorganism activity to decompose organic matter, is apparent. (d) The effect of nonsulfate fertilizer treatment, having no source of producing inhibitor such as hydrogen sulfide, was significant. (e) All the yield components, decided around the young premodia formation stage attaining to the maximum inhibitor concentration in soil and minimum root activity, are significantly decreased.

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Trace Metals in Surface Sediments of Garolim Bay, Korea (가로림만 표층 퇴적물 내 미량금속 분포 특성)

  • PARK, KYOUNGKYU;CHOI, MANSIK;JOE, DONGJIN;JANG, DONGJUN;PARK, SOJUNG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.25 no.2
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    • pp.9-25
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    • 2020
  • In 2010 and 2015, total 77 surface sediment samples were collected to assess the anthropogenic effects of trace metals in surface sediments of Garolim Bay, and the physical characteristics (particle size and specific surface area) and geochemical components (major (Al, Ca, Fe, K, Ba) and trace metals (Mn, Cs, Cr, Co, Ni, Cu, Zn, Pb), organic carbon and calcium carbonate) were analyzed. Mean grain size of Garolim Bay surface sediments ranged from 0.51-5.58 Ø (mean 3.98 Ø) and increased from the inlet of bay to the inner bay, and from the waterway to the land. Most of the metal concentrations except for some elements showed the similar distribution to those of mean grain size and specific surface area. As the particle size decreased and the specific surface area increased, the metal concentration increased. In order to estimate the factors controlling the concentration of trace metals, factor analysis was performed, and three factors were extracted (92.7% of the total variation). Factor 1 accounted for 71.3% of the total variation, which was a grain size factor. Factor 2 accounted for 14.2% of the total variation, Factor 3 accounted for 7.2% of the total variance. Enrichment factor was calculated using the particle size corrected background concentration. Metals with a enrichment factor of 1.5 or higher and the number of samples were 4 for Cr (St. 1, 16, 27, 39) and 1 for Pb (St. 39), but there were little differences in the concentrations of 1M HCl leached metals for these metals. The percentage of 1M HCl leached fraction to total metal concentration decreased in the order of Pb~Co>Cu>Zn~Mn>Ni>Cr. Comparing this value with contaminated and clean sediments in other coastal areas, the percentages for each metal were similar regardless of the trace metal levels in all regions. This fact might be resulted from the reaction between the 1M HCl solution and the different sediment constituents, indicating that there is a limit to apply this percentage of leached metal to the estimation of the contamination extent.

Composition and emission characteristics of fine particulate matters at the 1100 Site of Mt. Halla during 2011-2012 (한라산 1100고지 대기 미세먼지의 조성 및 배출 특성: 2011~2012년 측정)

  • Song, Jung-Min;Bu, Jun-Oh;Kim, Won-Hyung;Ko, Hee-Jung;Kang, Chang-Hee
    • Analytical Science and Technology
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    • v.29 no.5
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    • pp.209-218
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    • 2016
  • PM10 and PM2.5 samples were collected at the 1100 site of Mt. Halla in Jeju Island during 2011~2012, and their ionic and elemental species were analyzed, in order to investigate the characteristics of emission sources as well as aerosol compositions. The mass concentrations of PM10 and PM2.5 were 22.0±13.1 µg/m3 and 11.3±6.1 µg/m3, respectively, showing 2.4~2.6 times lower than those of the capital city area of Korea. The composition ratios of major secondary pollutants (nss-SO42−, NH4+, and NO3) were the highest as 85.5 % for PM10 and 91.3 % for PM2.5, and followed by the order of marine (Na+, Cl, and Mg2+), organic acid (HCOO and CH3COO), and soil (nss-Ca2+) sources. Among the elemental species in PM10, soil-originated components (Al, Fe, and Ca) were consisted of 50.9 %, which was higher proportion than marine and anthropogenic elements. The acidification of the fine particulate matters was found to be influenced mostly by sulfuric and nitric acids, and these acids were mainly neutralized by calcium carbonate in PM10 and by ammonia in PM2.5. The clustered back trajectories showed that 47 % of total air mass inflows was from the China, and the concentrations of NO3 and nss-Ca2+ were especially high corresponding to the inflows.

The Absorption and Purification of Air Pollutants and Heavy Metals by Selected Trees in Kwangju (광주지역(光州地域)에서 주요(主要) 수목(樹木)의 대기오염물질(大氣汚染物質)과 중금속(重金屬) 흡수(吸收) 정화기능(淨化機能)에 관(關)한 연구(硏究))

  • Cho, Hi Doo
    • Journal of Korean Society of Forest Science
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    • v.88 no.4
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    • pp.510-522
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    • 1999
  • The air pollutants ; $SO_2$, $SO{_4}^{-2}$, $NO{_3}^-$, $Cl^-$ are absorbed into soils through falling with dusts and rain from the atmosphere. The sources of heavy metal contaminants in the environments are agricultural and horticultural materials, sewage sludges, fossil fuel combustion, metallurgical industries, electronics and waste disposal etc.. The soils and hydrosphere can be polluted on the way of the circulation of these heavy metals. Studied pollutant anions are $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ and heavy metals are Se, Mo, Zn, Cd, Pb, Mn, Cr, Co, V, As, Cu and Ni which are the elements to be concerned with the essentials for plants, with animal and human health. This study is with the aim of selecting the species of roadside trees and green space trees which have excellent absorption of air pollutants and heavy metals from the atmosphere and the soils in the urban area. Two areas are designated to carry out this study : urban area ; Kwangju city and rural area ; the yard of Forest Environment Institute of Chollanam-do, at Sanje-ri, Sampo-myum, Naju city, Chollanam-do (23km away from Kwangju). This study is carried out to understand the movement of anions and heavy metals from the soils to the trees in both areas, the absorption of anions and heavy metals from atmosphere into leaves and the amounts of anions and heavy metals in leaves and fine roots(< 1mm dia.) of roadside trees and green space trees in Kwangju and trees in the yard of Forest Environment Institute of Chollanam-do. The tree species selected for this study in both areas are Ginkgo biloba, Quercus acutissima, Cedrus deodara, Platanus occidentalis, Robinia pseudoacacia, Alnus japonica. Metasequoia glyptostroboides. Zekova serrata. Prunus serrulata var. spontanea, and Pinus densiflora. The results of the study are as follows : 1. $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ concentrations are higher in the soils of the urban area than in those of the rural area, and $NO{_3}^-$ and $SO{_4}^{-2}$ are higher in the leaves than in the roots due to the absorption of the these pollutants through the stomata. 2. Ginkgo biloba, Robinia pseudoacacia. Zekova serrata, Quercus acutissima, and Platanus occidentalis can be adequated to the roadside trees and the environmental trees due to their good absorption of $NO{_3}^-$ and $SO{_4}^{-2}$. 3. Heavy metals in the soils of both areas are in the order of Mn > Zn > V > Cr > Pb > Ni > Cu > Mo> Cd, and in the leaves and roots of the trees in the both areas are in the order of Mn>Zn>Cr>Cu>V>Ni. Both orders are similar ones except V. There are more in the urban soils than in the rural soils in amount of Mn, Zn, Pb, V, Cu. 4. It is supposed that there is no antagonism between Mn and Zn in this study. 5. Se, Co and As are not detected in the soils, the leaves and the roots in both areas. Sn, Mo, Cd and Pb are also not detected in the leaves and roots in spite of considerable amount in the soils of both areas.

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