• Title/Summary/Keyword: Fog chemistry

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Aerosol Deposition and Behavior on Leaves in Cool-temperate Deciduous Forests. Part 2: Characteristics of Fog Water Chemistry and Fog Deposition in Northern Japan

  • Yamaguchi, Takashi;Noguchi, Izumi;Watanabe, Yoko;Katata, Genki;Sato, Haruna;Hara, Hiroshi
    • Asian Journal of Atmospheric Environment
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    • v.7 no.1
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    • pp.8-16
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    • 2013
  • The fog water chemistry and deposition in northern Japan were investigated by fog water and throughfall measurements in 2010. Fog water was sampled weekly by an active-string fog sampler at Lake Mashu from May to November. Throughfall measurements were conducted using rain gauges under three deciduous trees along the somma of the lake from August to October. The mean fog deposition rate (flux) was calculated using throughfall data to estimate the total fog water deposition amount for the entire sampling period. $NH_4{^+}$ and $SO{_4}^{2-}$ were the most abundant cation and anion, respectively, in the fog water samples. A mean pH of 5.08 in the fog water, which is higher than those in rural areas in Japan, was observed. The [$NH_4{^+}$]/[$SO{_4}^{2-}$] equivalent ratio in fog water was larger than 1.0 throughout the study period, indicating that $NH_3$ gas was the primary neutralizing agent for fog water acidity. The mean rate and total amount of fog water deposition were estimated as 0.15 mm $h^{-1}$ and 164 mm, respectively. The amounts of nitrogen and sulfate deposition via fog water deposition were corresponded to those reported values of the annual deposition amounts via rainfall.

A Study on the Behavior and Deposition of Acid Precipitation Chemical Composition of Fog Water at Chunchon (1996~1997) (산성강하물의 침착량과 동태 해명에 관한 연구 -춘천 지역 안개의 화학 조성 (1996~1997))

  • Kim, Man-Goo;Lim, Yang-Suck;Park, Ki-Jun;Hwang, Hoon
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.5
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    • pp.491-498
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    • 1998
  • Fog water samples were collected at Chunchon, Korea, by using active fog sampler during foggy Period in fall of 1996 and 1997. The average annual foggy days at Chunchon increased from 37 days, for the yearn 1963 ∼ 1973, to 63 days , for the year 1974∼1993 that followed the construction of Lake Soyang. Volume weighted mean pH of fog water was 5.5 with a range of 4.8 to 7.0 in 1996, and 5.0 with a range of 4.1 to 6.6 in 1997. These pH values were higher than those of rain water sampled in corresponding years. However the concentration of ionic species in fog water were 26 times higher than those of rain water. The major anions in fog water were in order of SO42-, NO3- and Cl-, and their average concentrations were 1770.6meq/ml, 346.2 meq/ml, 216 meq/ml in 1996, and 901.8meq/ml, 269.6meq/ml, 141.0meq/ml in 1997, respectively. The major cations were Ca2+, NH4+, Mg2+ and K+, and their average concentrations frere 408.5meq/ml, 280.0meq/ml, 43.8meq/ml, 45.2meq/ml in 1996, and 400.4 meq/ml, 299.0meq/ml, 73.1meq/ml, 44.5meq/ml in 1997, respectively. The fraction acidity of fog water was 0.006 and that of rain water was 0.2, which means fog water was much more neutralized than rain water.

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Variation Characteristics of TSP Ionic Compositions by Meteorological Phenomena in Jeju Island (기상현상에 따른 제주지역 TSP의 이온조성 변화 특성)

  • Ko, Hee-Jung;Kim, Won-Hyung;Lee, Seung-Hoon;Bu, Jun-Oh;Kang, Chang-Hee;Hu, Chul-Goo
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.6
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    • pp.723-733
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    • 2011
  • The ionic compositions were analyzed from the TSP samples collected at Gosan site in Jeju Island between 2000 and 2008, in order to examine the characteristics of atmospheric aerosols in accordance with the meteorological conditions. For the Asian Dust influence on the ionic compositions, the concentration ratios of $NH_4{^+}$, nss-${SO_4}^{2-}$, $NO_3{^-}$, and $K^+$ were about 1.2~2.3 during Asian Dust over Non-Asian Dust periods, noticeably that of nss-$Ca^{2+}$ was 6.8. Meanwhile the concentrations of nss-${SO_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$ have increased as 1.8~4.4 times during the haze event periods, and 1.0~1.6 times during the fog and mist events. The ion balance has resulted that the anionic concentrations are relatively lower than the cationic concentrations, and the discrepancy appears more decidedly as a strong Asian Dust effect. The ammonium ion balance has shown that it exists as a mixture of $NH_4HSO_4$ and $(NH_4)_2SO_4$. The concentration ratios of nss-${SO_4}^{2-}/NO_3{^-}$ for Asian Dust, haze, fog-mist, and non-event periods were respectively 1.8, 5.9, 4.6, and 2.9, which were higher values compared to those in urban areas of China as well as other domestic regions. Especially, the high ratios of sulfur oxides could be presumed by the fact that the longrange transport of air pollutants from Asia continent might affect the atmospheric aerosols of Jeju Island.

Radioactivity concentrations of natural radionuclides in fine dust of Jeju, Korea

  • Chung-Hun Han;Sohyeon Lim;Hee-Jung Im
    • Analytical Science and Technology
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    • v.36 no.4
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    • pp.191-197
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    • 2023
  • Radioactivity concentrations for natural radionuclides were determined from fine dust samples collected in Jeju, Korea according to atmospheric events (Asian dust, haze, fog-mist, and non-event), and radium equivalent activity was calculated. The mean atmospheric radioactivity concentrations for 238U, 232Th, and 40K in 127 fine dust samples were 0.49, 0.24, and 7.23 µBq m-3, respectively, and the radium equivalent activity was 33.25 Bq kg-1. The mean concentrations of 238U and 232Th in the fine dust during the Asian dust period were 1.31 and 1.60 µBq m-3, respectively, above the global average, while the values for the other three atmospheric events were lower. The ratio of 232Th/238U radioactivity during the Asian dust period was 1.22, higher than the ratio for the other three atmospheric events.

A Study on Discoloration of Traditional Paintings by an Inorganic Pigment (무기 안료에 의한 전통회화의 변색 연구)

  • Kim, Dong Won;Kwak, Sam Tak;Seo, Yong Soo;Kim, Il Kyu;Moon, Myung Jun
    • Applied Chemistry for Engineering
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    • v.23 no.6
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    • pp.567-571
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    • 2012
  • The discoloration of traditional paintings could be induced by various chemical reactions of inorganic pigments due to temperature, humidity, light and air pollution. In this study, we made artificial samples including azurite and malachite as inorganic pigments using the traditional method on hanji called 'Korean paper'and investigated the artificial aging process occurred by the interaction between pigments and environmental factors. It was found that the azurite was influenced by the humidity of weathering tests and the salt fog of salt spray tests according to XRD and TGA results. However, it was shown that the malachite was chemically changed by the ultraviolet radiation of weathering tests and UV radiation tests according to color difference and TGA results.

Long-term Trends of Visibility and Air Quality in Seoul, Ganghwa, Susan, Gwangju, Jeju (서울, 강화, 서산, 광주, 제주지역에서의 장기간 대기오염 및 시정 변화경향에 대한 연구 : 1990년 1월~2001년 7월)

  • Han, J.S.;Moon, Kwang-Joo;Kong, B.J.;Hong, Y.D.;Lee, S.J.;Shin, J.Y.
    • Journal of Environmental Impact Assessment
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    • v.13 no.4
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    • pp.197-211
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    • 2004
  • Visibility impairment was known as an indicator of the increased air pollution. In many previous studies, it is known that both directly emitted fine particles mainly from vehicles and secondary aerosols from photochemical reactions could contribute to this visibility impairment in addition to the meteorological condition. Furthermore, the visibility showed different change patterns according to the geographical condition. In order to research into the influence of these factors on visibility, this study analyzed the visibility at 15:00, observed from 1990 to 2001 in Seoul, Ganghwa, Susan, Gwangju, Jeju. As a result, the visibility was increased in Seoul except the rainfall period, but in Susan, Gwangju, Jeju, it decreased with the relative humidity (RH). Especially, in Seoul, the number of low visibility days was larger than other sites and variations of the visibility were sensitive to the concentration of air pollutants, such as TSP, $NO_2$, $O_3$. The visibility impairment was mainly observed in meteorological condition of RH<50% and relatively stationary front. Therefore it is inferred that photochemical smog could lead to the low visibility in Seoul. On the other hands, in Ganghwa and Susan, when RH was 60~70%, the low visibility observed under the influence of the transports of air pollutants from nearby cities as well as humid air mass from coastal region. And in Jeju, sea fog and humid air mass caused the visibility impairment when the RH was larger than 80%. Finally, during the observational period, some cases of low visibility phenomena were simultaneously observed in the vast region including Seoul, Susan, Ganghwa. It not only includes the visibility aggravation by Asian Dust, but also could be caused by the movement and diffusion of flying dust or secondary aerosols. Moreover, the result shows that these phenomena could be mainly influenced by meteorological factors covering the wide regions.

Concrete structures under combined mechanical and environmental actions: Modelling of durability and reliability

  • Vorechovska, Dita;Somodikova, Martina;Podrouzek, Jan;Lehky, David;Teply, Bretislav
    • Computers and Concrete
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    • v.20 no.1
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    • pp.99-110
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    • 2017
  • Service life assessments which do not include the synergy between mechanical and environmental loading are neglecting a factor that can have a significant impact on structural safety and durability assessment. The degradation of concrete structure is a result of the combined effect of environmental and mechanical factors. In order to make service life design realistic it is necessary to consider both of these factors acting simultaneously. This paper deals with the advanced modelling of concrete carbonation and chloride ingress into concrete using stochastic 1D and 2D models. Widely accepted models incorporated into the new fib Model Code 2010 are extended to include factors that reflect the coupled effects of mechanical and environmental loads on the durability and reliability of reinforced concrete structures. An example of cooling tower degradation by carbonation and an example of a bended reinforced concrete beam kept for several years in salt fog are numerically studied to show the capability of the stochastic approach. The modelled degradation measures are compared with experimental results, leading to good agreement.

Review of Recent Smog Chamber Studies for Secondary Organic Aerosol (스모그 챔버를 이용한 이차 초미세유기먼지의 최근 연구 동향)

  • Lim, Yong Bin;Lee, Seung-Bok;Kim, Hwajin;Kim, Jin Young;Bae, Gwi-Nam
    • Journal of Korean Society for Atmospheric Environment
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    • v.32 no.2
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    • pp.131-157
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    • 2016
  • A smog chamber has been an effective tool to study air quality, particularly secondary organic aerosol (SOA), which is typically formed by atmospheric oxidation of volatile organic compounds (VOCs). In controlled environments, smog chamber studies have validated atmospheric oxidation by identifying, quantifying and monitoring products with state-of-art instruments (e.g., aerosol mass spectrometer, scanning mobility particle sizer) and provided chemical insights of SOA formation by elucidating reaction mechanisms. This paper reviews types of smog chambers and the current state of smog chamber studies that have accomplished to find pathways of SOA formation, focusing on gas-particle partitioning of semivolatile products of VOC oxidation, heterogeneous reactions on aerosol surface, and aqueous chemistry in aerosol waters (e.g., cloud/fog droplets and wet aerosols). For future chamber studies, then, this paper discusses potential formation pathways of fine particles that East Asia countries (e.g., Korea and China) currently suffer from due to massive formation that gives rise to fatal health problems.

A Study on The Fruits Mentioned in the Bible (성서에 언급된 과실에 관한 연구)

  • Kim, Sung-Mee;Lee, Kwang
    • Journal of the East Asian Society of Dietary Life
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    • v.9 no.2
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    • pp.149-160
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    • 1999
  • This paper is intended to find out what kinds of fruits are mentioned in the Bible and how they were used in those days. It has also analyzed in what terms they are expressed in the Korean Version of the Bible and studied agricultural regulations involved in the religion, and allegorical uses of the fruits. Olives were the primary fruit in the economy of the ancient times, followed by figs and vines. In addition, there are mentioned in the Bible almonds, apples, dates. mulberries and pomegranates. Olive trees have been grown for more than six thousand years. The Hebrew word. Zayit is mentioned in the Bible more than fifty times. Olive trees are not so beautiful in themselves but as they give us humans abundant reap and a lot of oil, they have been thought to be beautiful. Olive trees grow well on the seaside in the salty air and fog. Vines began to grown as early as in the Bronze Age(the period of 3000 to 2000 B.C.). In Northern Greece, grape seeds were found to belong to the year 4500 B.C. or so. The vine gardens produced raisins and wine as well as vines. Figs are the fruit which are first mentioned in the Bible(Genesis 3:7) and they were the precious product of the Palestine people, which is described in Deuteronomy 8:8. Figs are sweet and watery and can easily quench thirst on hot summer days. They were used for cookies and wine in the raw or dried state. An apple, which is tappuah in Hebrew, is mentioned as 'Sagwa' six times in the Revised Korean Version, and in the Korean Joint Version it is twice mentioned as 'Sagwa' and as 'Neungum' four times. In ASV and KJV, 'apple' appears eleven times. which is because' the apple of eye' is translated in the 'Nun-dong-ja(the pupil of the eye)'In the Korean Version. 'Sagwa(apple)'of Proverb 25:11, the Song of Songs 2:3, 2:5, 7:8, 8:5 and Joel 1 :12 have been thought to be doubtful. because apple trees cannot be grown in the areas mentioned in the Bible. Some maintain that the apples in the Bible refer to apricots(Prunus armeniaca, Citrus medica L.) or golden oranges (Citrus sinensis L. Obsbeck) which is confusing. In the Revised Korean Version, 'Salgu(apricots)' appears eight times while ASV and KJV translate almond into 'Salgu'. So since translating a genuine apricot into 'Salgu' can be confusing, a great care should be taken in the translation into Korean. Some hold that as some papyri arround the year 1200 B.C. describes pomegranate, apple, olive and fig trees growing on the Nile delta, tappuah rightly refers to 'Sagwa(apple)' In the Korean Joint Version, Sagwa and Neungum are used together to refer to the same fruit, which should be avoided. It is desirable to use the same word for the same thing. Sagwa' showing up six times In the HeL.Ised Korean Version should all be replaced by 'Neungum' Dates symbolized peace and abundance were used for food in the raw or dried state, and were made into honey. Pomegranates can be eaten in the raw state and be used for sherbets and wine. Juice made of promegranates can be mixed with wine and drunk.

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