• Title/Summary/Keyword: Distribution science

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A Study on Detection Methodology for Influential Areas in Social Network using Spatial Statistical Analysis Methods (공간통계분석기법을 이용한 소셜 네트워크 유력지역 탐색기법 연구)

  • Lee, Young Min;Park, Woo Jin;Yu, Ki Yun
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.4
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    • pp.21-30
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    • 2014
  • Lately, new influentials have secured a large number of volunteers on social networks due to vitalization of various social media. There has been considerable research on these influential people in social networks but the research has limitations on location information of Location Based Social Network Service(LBSNS). Therefore, the purpose of this study is to propose a spatial detection methodology and application plan for influentials who make comments about diverse social and cultural issues in LBSNS using spatial statistical analysis methods. Twitter was used to collect analysis object data and 168,040 Twitter messages were collected in Seoul over a month-long period. In addition, 'politics,' 'economy,' and 'IT' were set as categories and hot issue keywords as given categories. Therefore, it was possible to come up with an exposure index for searching influentials in respect to hot issue keywords, and exposure index by administrative units of Seoul was calculated through a spatial joint operation. Moreover, an influential index that considers the spatial dependence of the exposure index was drawn to extract information on the influential areas at the top 5% of the influential index and analyze the spatial distribution characteristics and spatial correlation. The experimental results demonstrated that spatial correlation coefficient was relatively high at more than 0.3 in same categories, and correlation coefficient between politics category and economy category was also more than 0.3. On the other hand, correlation coefficient between politics category and IT category was very low at 0.18, and between economy category and IT category was also very weak at 0.15. This study has a significance for materialization of influentials from spatial information perspective, and can be usefully utilized in the field of gCRM in the future.

Distribution characteristics on volatile organic compounds at the forest of Mt. mudeung and downtown (무등산 숲과 도심에서 휘발성유기화합물질의 분포 특성)

  • Lee, Dae-haeng;Park, Kang-soo;Lee, Se-hang;Song, Hyeong-myeong;Lee, Ki-won;Jeong, Hee-yoon;Seo, Gwang-yeob;Cho, Young-gwan;Kim, Eun-sun
    • Analytical Science and Technology
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    • v.28 no.3
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    • pp.246-254
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    • 2015
  • From 2013 to 2014, volatile organic compounds (VOCs) were analyzed to determine biogenic volatile organic compounds (BVOCs) and anthropogenic volatile organic compounds (AVOCs) at eight sites in Mt. Mudeung and one site in downtown, by using a GC/Mass-ATD (automatic thermal desorber). The concentration of terpene noted as biogenic volatile organic compounds at Pungamjeong (PA), in a forest of Chamaecyparis obtusa, was 821 pptv, which was the highest among the eight sites. This value was followed by Wonhyogyegok (WH: 785 pptv), Norritzae (NZ, coniferous forest: 679 pptv), Dongjeokgol (DJ, mixed species forest: 513 pptv), Jangbuljae (JB, Abies koreana: 476 pptv), and Seinbongsamgerri (SS, pine trees: 464 pptv). 11~15 species of terpene was detected in the forest depending on the site. At PA in May, α-pinene showed the highest value, occupied 20% of terpene followed by coumarin, sabinene, phellandrene, myrcene, borneol, eucalyptol, β-pinene, cymene, δ-limonene, γ-terpinene, camphor, camphene, and mentol in the order. The mean concentrations of AVOCs were 0.74~2.52 ppbv in the forests and 3.14 ppbv in the downtown area. From May to July, the AVOCs ratios of the downtown to each forest were 1.9~4.0. Among 10 species of AVOCs, the sum of toluene and benzene was 2.34 ppbv and occupied 75%. In June, the ratios of toluene were 44.1% at DJ site and 53.1% at JW site (downtown). The BVOCs showed a positive correlation with the AVOCs at the forest sites (r = 0.328), which was statistically insignificant (p = 0.184).

Growth and Phytochemicals of Lettuce as Affected by Light Quality of Discharge Lamps (방전램프의 광질에 따른 상추의 생장 및 파이토케미컬 분석)

  • Lee, Jae Su;Nam, Sang Woon;Kim, Yong Hyeon
    • Journal of Bio-Environment Control
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    • v.22 no.4
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    • pp.400-407
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    • 2013
  • This study was performed to analyze the effect of light quality of discharge lamp on growth and phytochemicals contents of lettuce (Lactuca sativa L. cv. Jeokchima) grown under metal halide (MH) lamp, high-pressure sodium (HPS) lamp, and xenon (XE) lamp in a plant factory. Cool-white fluorescent (FL) lamp was used as the control. Photoperiod, air temperature, relative humidity, $CO_2$ concentration, and photosynthetic photon flux (PPF) in a plant factory were 16/8 h (day/night), $22/18^{\circ}C$, 70%, 400 ${\mu}mol{\cdot}mol^{-1}$, and 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. MH lamp had the greatest fraction of blue light (400-500 nm) of 23.0%. However, HPS lamp had the lowest fraction of 4.7% for blue light and the greatest fraction of 38.0% for red light (600-700 nm). At 11 and 21 days after transplanting, leaf length, leaf width, leaf area, shoot fresh weight, and shoot dry weight of lettuce as affected by the light quality of the discharge lamp were significantly different. The leaf area of lettuce grown under HPS, MH, and XE lamp increased by 45.7%, 16.3%, and 9.5%, respectively, as compared to the control. These results were similar for shoot fresh weight. Growth characteristics of lettuce grown under HPS lamp increased since HPS lamp had more fraction of red light. However, growth of lettuce grown under MH and XE lamp decreased since they had more fraction of blue light. As compared to the control, the ascorbic acid in lettuce leaves grown under discharge lamp decreased. The greatest anthocyanins accumulation of 0.70 mg/100 g was found at MH treatment. Anthocyanins content in lettuce leaves grown under XL and HPS lamp were 79.3% and 8.6%, respectively, compared with the control. Growth and phytochemicals contents of lettuce were highly affected by the different spectral distribution of the discharge lamp. These results indicate that the combination of discharge lamp or LED lamp for enhancing the light quality of discharge lamps is required to increase the growth and phytochemicals accumulation of lettuce in controlled environment such as plant factory.

Prevailing Subsurface Chlorophyll Maximum (SCM) Layer in the East Sea and Its Relation to the Physico-Chemical Properties of Water Masses (동해 전역에 장기간 발달하는 아표층 엽록소 최대층과 수괴의 물리 화학적 특성과의 상관관계)

  • Rho, TaeKeun;Lee, Tongsup;Kim, Guebuem;Chang, Kyung-Il;Na, TaeHee;Kim, Kyung-Ryul
    • Ocean and Polar Research
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    • v.34 no.4
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    • pp.413-430
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    • 2012
  • To understand the scales of the spatial distribution and temporal duration of the subsurface chlorophyll-a maximum (SCM) observed in the Ulleung Basin of the East Sea, we analyzed physical and chemical data collected during the East Asian Seas Time-series-I (EAST-I) program. The SCM layer occurred at several observation lines from the Korea Strait to $37.9^{\circ}N$ in the Ulleung Basin during August of 2008 and 2011. At each observation line, the SCM layer extended from the coast to about 200 km off the coast. The SCM layer was observed between 30 and 40 m depth in the Ulleung Basin as well as in the northwestern Japan Basin along $132.3^{\circ}E$ from $38^{\circ}N$ to $42.3^{\circ}N$ during July 2009, and was observed around 50 m depth in the northeastern Japan Basin ($135-140^{\circ}E$ and $40-45^{\circ}N$) during July 2010. From these observed features, we hypothesize that the SCM layer observed in the Ulleung Basin may exist in most of the East Sea and may last for at least half-year (from the early May to late October). The nutrient supply mechanism for prolonged the SCM layer in the East Sea was not known, but it may be closely related to the horizontal advection of the nutrient rich and low oxygen waters observed in the Korea Strait between a 50 m depth to near the bottom. The prolonged development of the SCM layer in the Ulleung Basin may result in high primary production and would also be responsible for the high organic carbon content observed in the surface sediment of the region.

A Study OR Investigation of the Factors having Affect on Junior Highschool Boys관 Practice of Health Care (중학교 남학생들의 건강관리 실천과 이에 영향을 미치는 요인 조사 연구)

  • 기경숙
    • Journal of Korean Academy of Nursing
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    • v.15 no.1
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    • pp.59-75
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    • 1985
  • Accepting the health as the fundamental human right, the nation and society came to admit the duty to give it to all the people. Korean government is expanding the Primary Health Care as one of the policies for developing the people's health by the lead of community. Like this current situation the School Health Service which is the center of community Health Service schould be active to keep, promote and maintain the health of students and teachers. This investigation was attempted to help to establish the basis of the Health Education Program which would perform the health education efficiently and bring the reforming of student's health control, by measuring the degree of junior high school student's practice concerning health care and con-firming the relationship of knowledge, concern and level of health. The subjects for this study were made up 296 boys at the third grade in a school, located in Seoul. The tool for this study was questionaire. Data were collected for five days, September 22∼26, 1983. The investigators explained the students how to answer the questions of the survey questionaire and then collected the survey cards immediately. The data were analyzed by means of percentages, Pearson Correlation Coefficient and Stepwise Multiple Regression. The results of this study are as follows. 1. The subjects' reaction to the practice concerning Health Care; According to the average proportion of practice concerning health care, subjects' practice in the aspect of Infectious Disease Care is the highest 82.4% and they showed their practice in the aspect of the accident prevention by 77.5% and in the aspect of mental health by 74.8%. Their practice in the aspect of personal hygiene and daily lifehabit is the lowest 71.2%. 2. Health Knowledge; The whole mark distribution of health knowledge is ranged from the lowest 4 point to the highest, 30 point, therefore point range is 26.0. The Average point is 16.58. 11.2% of students solved more than two thirds of personal knowledge levels. 81.4% of students did more than one third of them. 7.415 of students did less than one third of them. 3. Health Concern; The Students of the average 3.99 point respond positively to the question about the health concern, ‘They think health is more important than money’, this is the highest rate. The students of the average 2.78 respond“when they are sick, they enter the appointed hospital where they own choose”, while it is the lowest. 4. Subjects' response to the health level are at follow: Very healthy 26.0%, healthy 47.0%, less healthy 10.5%, 34.9% of them have ever been sick within two weeks, the number of symptoms they reported amount to 114 and the number of cases poi one person is 0.35. 5. The hypotheses test about the practice concerning health care and the factor which effect on it. 1) The main first hypothesis:“The more knowledge of health the subjects have, the better they practice health care.”was accepted. (r=0.1582, p <0.05) 2) The minor first hypothesis:“The more interest in health subjects have, the better they practice”was accepted. (r=0.4354, p <0.001) 3) The minor second hypothesis;“The healthier subjects are, the better they practice health care”was accepted. (r=0.1069, p<0.05) As other test, partical correlation test is performed in other refine whether health knowledge, a fact influencing the students practice concerning health care, is associated with the practice after controlling the third variables. First, after controlling health concern, the correlation of health knowledge and practice concerning health care was kept. (r=0.1347, p <0.005) Second, after controlling health level, the correlation of health knowledge and practice concerning health care was kept. (r=0.1526, p <0.005) And finally, after controlling economic state, the correlation of health knowledge and practice concern-ing health care was kept. (r=0.1413, p <0.05) Additionally Stepwise Multiple Regression between practice concerning health care and variables. 1.6591 of compliance was explained with the know-ledge (F=5.584, p <0.05), 20.0% of compliance was explained with the health concern added to knowledge. (F=63,213, p <0.005) As the above, health knowledge obviously have effects on the practice about the health care. But, contrary to researcher's expectation, health concern has more affects than health knowledge. Therefore, we must grope the plan to enhance health concern through the regular curriculum and systematic health education for students. Besides, we must study further on, to find the factors which have affect on the practice concerning health care.

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A Study on the Breeding Density and Diet of Magpie Pica pica in Jeju Island1a (제주도에 서식하는 까치 Pica pica의 번식 밀도 및 식이물에 관한 연구)

  • Park, Joo-Yeon;Kim, Byoung-Soo;Oh, Hong-Shik
    • Korean Journal of Environment and Ecology
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    • v.22 no.6
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    • pp.648-657
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    • 2008
  • This research was conducted to investigate the breeding density and seasonal food items of the magpies in Jeju Island and the near-manned islets. The examination of nest distribution to determine breeding density was performed during breeding season from February 2006 to April 2008, and that of food items from May 2006 to February 2008. A total of 2,113 nests were found across Jeju Island, the average density was $1.33\;nest/km^2$, and the magpies were distributed up to 600 meters above the sea level. The nest density was the highest in the central areas of Jeju Island, with 688 nests at $3.61\;nest/km^2$, while that in the eastern areas was the lowest, with 214 nests at $0.66\;nest/km^2$. In terms of the number of nests depending on the height above the sea level, 1,172 nests, which was equivalent to the density of $1.85\;nest/km^2$, was observed below 100m and highest among the intervals of height, but 16 nests found at 500-600m were the lowest, corresponding to $0.20\;nest/km^2$. The number of nests found in the manned islets near Jeju Island was eight in Biyang-do with the density of $15.38\;nest/km^2$, nine in U-do with $1.49\;nest/km^2$, and one in Gapa-do with $1.15\;nest/km^2$, whereas none of nests were observed in Mara-do. The contents of stomach consisted of 17 types of prey sources including countless bones, eggshells, plants, and seed, most of which were the individuals of the order Coleoptera. In spring and summer, the foraging frequency for invertebrate animals such as insects was high, but less than 30% in winter. In contrast, the magpies preyed upon plants and seeds at the frequency of 10% and 30%, respectively, in spring, while the foraging frequencies for both of them were 100% in winter and higher than any of other seasons. Eggshells and bones of birds were also detected infrequently. If the density of the magpies, which may play role as the upper predator within the ecosystem, increases, it would be expected to affect directly the reduction of the number of the species and population of endemic animals such as small birds and reptiles, etc. Therefore, it is considered that long-term monitoring for the density of the magpies and precaution is prerequisite to minimize adverse effects on ecosystem.

Community Characteristics and Biological Quality Assessment on Benthic Macroinvertebrates of Bongseonsa Stream in Gwangneung Forest, South Korea (광릉숲 내 봉선사천의 저서성 대형무척추동물의 군집 특성 및 생물학적 하천평가)

  • Jung, Sang-Woo;Cho, Yong-Chan;Lee, Hwang-Goo
    • Korean Journal of Environment and Ecology
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    • v.31 no.6
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    • pp.508-519
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    • 2017
  • There have been many studies on monitoring of biodiversity changes and preservation of Gwangneung Forest Biosphere Reserve (GFBR) in South Korea in recognition of the rare ecosystem that has been preserved for a long period. However, there are few studies on diversity and community characteristics of benthic macroinvertebrates as an indicator of stream health of GFBR. The purpose of this study was to assess the water quality of Bongseonsa Stream that penetrated through Gwangneung Forest and the nearby torrents by analyzing the benthic macroinvertebrates community during April to September 2016. The investigation collected a total of 114 species of benthic macroinvertebrates belonging to 56 families, 17 orders, 8 classes, and 5 phyla from the Bongseonsa Stream and Kwangneung Stream. Ephemeroptera and Trichoptera were the largest groups in species diversity with 30 species (32.3%) and 16 species (17.2%), respectively, and Tubificidae sp., Baetis fuscatus, Antocha KUa, and Cheumatopsyche brevilineata, which usually habit in contaminated streams, appeared frequently. Among the feeding function groups, the gatherers and hunters appeared relatively frequently, and the shredders and scrapers appeared frequently in the torrents. Among the habitat oriented groups, the clingers and burrower appeared more frequently and represented the microhabitats in the shallow areas. The result of the analysis of benthic macroinvertebrates community showed that the dominant index was $0.48{\pm}0.10$ in average while it was lowest with 0.33 in GS 8 of the Gwangneung Forest torrent and highest in BS 1 of Bongseonsa Stream. The diversity and richness indices were inversely proportional to the dominant index and were 2.53 and 4.22, respectively, in GS 8 where the dominant index was low. The result of the analysis of community stability showed that area I, which had high resistance and restoration, was high in Bongseonsa Stream while the area III, which had low resistance and restoration, was high in Gwangneung Forest, indicating that the water system in Gwangneung Forest had a wider distribution of specifies sensitive to agitation. The biological water quality assessment showed ESB of $50.88{\pm}17.69$, KSI of $1.11{\pm}0.57$, and BMI of $78.55{\pm}11.05$. GS 8 of Gwangneung Forest torrent was judged to be the highest priority protective water area with the best water environment and I class water quality with ESB of 63, KSI of 0.55, and BMI of 89.9. On the contrary, BS 1 of Bongseonsa Stream was judged to be the high priority improvement area that had the lowest water quality rating of III with ESB of 25, KSI of 2.13, and BMI of 62.7. Although the diversity of water beetle was higher in the water system of nearby Bongseonsa Stream than the water system inside the Gwangneung Forest, the annual community structure appeared to have distinct differences.

Evolutionary Explanation for Beauveria bassiana Being a Potent Biological Control Agent Against Agricultural Pests

  • Han, Jae-Gu
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.27-28
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    • 2014
  • Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

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Composition comparison of PM10 and PM2.5 fine particulate matter for Asian dust and haze events of 2010-2011 at Gosan site in Jeju Island (황사와 연무 시 PM10 및 PM2.5 미세먼지 조성 비교: 2010-2011년 고산지역 측정)

  • Kim, Ki-Ju;Lee, Seung-Hoon;Hyeon, Dong-Rim;Ko, Hee-Jung;Kim, Won-Hyung;Kang, Chang-Hee
    • Analytical Science and Technology
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    • v.27 no.1
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    • pp.1-10
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    • 2014
  • The $PM_{10}$ and $PM_{2.5}$ samples were collected at Gosan Site of Jeju Island, and analyzed, in order to investigate the size distribution and pollution characteristics of their components. $NH{_4}{^+}$, nss-$SO{_4}^{2-}$, $K^+$, and $CH_3COO^-$ were mostly existed in fine particles. Meanwhile, $NO{_3}{^-}$ was distributed in both fine and coarse particles, and $Na^+$, $Cl^-$, $Mg^{2+}$, nss-$Ca^{2+}$ were rich in coarse particle mode. The concentrations of nss-$Ca^{2+}$ and $NO{_3}{^-}$ were increased 36.7 and 3.2 times in coarse particles, and 15.0 and 3.1 times in fine particles during the Asian Dust periods. Especially, the concentrations of crustal elemental species such as Al, Fe, Ca, K, Mg, Ti, Mn, Sr, Ba were highly increased for those periods. In the haze events, the concentrations of secondary air pollutants were increased 1.3~2.6 and 1.5~4.2 times in coarse and fine particles, respectively. Moreover, the remarkable increase of $NO{_3}{^-}$ concentration was also observed in fine particle mode. The factor analysis showed that the composition of coarse particles was influenced mainly by marine sources, followed by soil and anthropogenic sources. On the other hand, the fine particles were influenced by anthropogenic sources, followed by marine and soil sources.

Characterization of Humic and Fulvic Acids Extracted from Soils in Different Depth: Proton Exchange Capacity, Elemental Composition and 13C NMR Spectrum (깊이별 토양 휴믹산과 풀빅산의 특성 분석: 양성자교환용량, 원소성분비, 13C NMR 스펙트럼)

  • Shin, Hyun-Sang;Lee, Chang-Hoon;Rhee, Dong-Sock;Chung, Kun-Ho;Lee, Chang-Woo
    • Analytical Science and Technology
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    • v.16 no.4
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    • pp.283-291
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    • 2003
  • Humic and fulvic acids present in soils of different depth were extracted and their acidic functional groups and structural characteristics were analyzed and compared. The purpose of this study was to present a basic data needed to evaluate the effect of humic substances on depth distribution and migrational behaviour of radioactive elements deposited on soil. Acidic functional groups of the humic and fulvic acids were analyzed by pH titration method, and their proton exchange capacity (PEC, $mq\;g^{-1}$) and average $pK_a$ values were obtained. Structural characteristics of the humic and fulvic acids were analyzed using their CPMAS $^{13}C$ NMR spectra and elemental composition data. pH titration data showed that fulvic acids have higher acidic functional group contents ranging from 5.5 to $7.0meq\;g^{-1}$ compared with that of humic acids ($3.8{\sim}4.8meq\;g^{-1}$). From depth profiles, it has been found that PEC values of humic acids in deeper soil (> 8 cm) were higher than those at the surface soils. Elemental compositions (H/C ratio) and spectral features ($C_{arom}/C_{aliph}$ ratio) obtained from CPMAS $^{13}C$ NMR spectra showed that the aromatic character in humic acids was a relatively higher than that of fulvic acids, while lower in carboxyl carbon content. The aromatic character and carboxyl carbon contents of humic acids tend to increase as soil depth increased, but those of fulvic acid showed little differences by the soil depth range.