• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.32-43
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• 2008

Source samples were collected to construct source profiles for 9 different source types, including soil, road dust, gasoline/diesel-powered vehicles, a municipal incinerator, industrial sources, agricultural/biomass burning, marine aerosol, and a coal-fired power plant. Seasonal profiles for 'Chinese aerosol', aerosols derived from the urban area of China, were reconstructed from seasonal $PM_{2.5}$ compositions reported in Beijing, China. Ambient $PM_{2.5}$ at a receptor site was also measured during each of the four seasons, from April 2001 to February 2002, in Seoul. The Chemical Mass Balance receptor model was applied to quantify source contributions during the study period using the estimated source profiles. Consequently, motor vehicle exhaust (33.0%), in particular 23.9% for diesel-powered vehicles, was the largest contributor affecting the $PM_{2.5}$ levels in Seoul, followed by agricultural/biomass burning (21.5%) and 'Chinese aerosol' (13.1%), indicating contributions from long-range transport. The largest contributors by season were: for spring, 'Chinese aerosol' (31.7%); for summer, motor vehicle exhaust (66.9%); and for fall and winter, agricultural/biomass burning (31.1% and 40.1%, respectively). These results show different seasonal patterns and sources affecting the $PM_{2.5}$ level in Seoul, than those previously reported for other cities in the world.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.56-61
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• 2009

Paradigm depending only on fossil fuel for building heat source is rapidly changing. Accelerating the change, as it has been known, is obligation for reducing green house gas coming from use of fossil fuel, i.e. reaction to United Nations Framework Convention on Climate Change. In addition, factors such as high oil price, unstable supply, weapon of petroleum and oil peak, by replacing fossil fuel, contributes to advance of environmental friendly renewable energy which can be continuously reusable. Therefore, current new energy policies, beyond enhancing effectiveness of heat using equipments, are to make best efforts for national competitiveness. Our country supports 11 areas for new renewable energy including sun light, solar heat and wind power. Among those areas, ocean thermal energy specifies tidal power generation using tide of sea, wave and temperature differences, wave power generation and thermal power generation. But heat use of heat source from sea water itself has been excluded as non-utilized energy. In the future, sea water heat source which has not been used so far will be required to be specified as new renewable energy. This research is to survey local heating system in Europe using sea water, central solar heating plants, seasonal thermal energy store and to analyze large scale central solar heating plants in German. Seasonal thermal energy store necessarily need to be equipped with large scale thermal energy store. Currently operating central solar heating system is a effective method which significantly enhances sharing rate of solar heat in a way that stores excessive heat generating in summer and then replenish insufficient heat for winter. Construction cost for this system is primarily dependent on large scale seasonal heat store and this high priced heat store merely plays its role once per year. Since our country is faced with 3 directional sea, active research and development for using sea water heat as cooling and heating heat source is required for seashore villages and building units. This research suggests how to utilize new energy in a way that stores cooling heat of sea water into seasonal thermal energy store when temperature of sea water is its lowest temperature in February based on West Sea and then uses it as cooling heat source when cooling is necessary. Since this method utilizes seasonal thermal energy store from existing central solar heating plant for heating and cooling purpose respectively twice per year maximizing energy efficiency by achieving 2 seasonal thermal energy store, active research and development is necessarily required for the future.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.2
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• pp.155-163
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• 2020

Indoor airborne particles are consisted of outdoor- and indoor-generated particles, which can be characterized by their compositions, generation features and toxicity. The identification of source contribution of indoor and outdoor origin to indoor particles is important to understand PM_2.5 transport in a building as well as its impact on occupant health. The objective of this study is to investigate seasonal source contribution to indoor PM_2.5 concentration depending on airtightness of apartment units. To evaluate the source contribution, particle transport including penetration, generation, exfiltration in an apartment housing unit was simulated by using CONTAM with particle and airflow simulation parameters obtained from field measurements. The result showed that the outdoor source contribution to indoor air was relatively dominant in the leaky housing unit during spring (77.2%) and winter (73.9%), and the indoor source was dominant in the airtight housing unit during summer (60.3%) and fall (60.7%). These results indicate the seasonal health risk of indoor PM_2.5 can be varied according to airtightness of apartment units.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.2
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• pp.208-215
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• 2016

Pinic acid (PA) and cis-pinonic acid (CPA) in the atmospheric particulate matter with an aerodynamic diameter of less than or equal to a nominal $10{\mu}m$ ($PM_{10}$) were analyzed for the samples collected during the period of April 2010 to April 2011 at Jongro in Seoul. Both pinic acid and cis-pinonic acid showed higher seasonal average concentrations in summer (PA; $18.9ng/m^3$, CPA; $16.0ng/m^3$) than winter (PA; $5.3ng/m^3$, CPA; $5.9ng/m^3$). They displayed a seasonal pattern associated with temperature reflecting the influence on emissions of ${\alpha}-pinene$ and ${\beta}-pinene$ from conifers and their photochemical reaction. These results were confirmed through Pearson correlation coefficient between CPA, PA and $O_3+NO_2$, temperature. CPA was only correlated with n-alkanes ($C_{29}$, $C_{31}$, $C_{33}$) from biogenic source. PA was correlated with n-alkanes ($C_{29}$, $C_{31}$, $C_{33}$), n-alkanoic acid ($C_{20}$, $C_{22}$, $C_{24}$) from biogenic source and n-alkanes ($C_{28}$, $C_{30}$, $C_{32}$), and n-alkanoic acid ($C_{16}$, $C_{18}$) from anthropogenic source. These results showed that the formation of PA and CPA from ${\alpha}-pinene$ and ${\beta}-pinene$ is related to organic compounds from biogenic source. And it is possible for PA to be effected by organic compounds from anthropogenic source.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.1
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• pp.11-23
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• 2002

The concentrations of aldehydes were measured in downtown area of Buchun and Kwanghwamoon of Seoul from October 1997 to August 1998 using 2-series impingers. The data have been analysed to identify the seasonal pattern of aldehyde sources in metropolitan areas. The measured concentration (in ppbv) of aldehydes were 8.86 $\pm$ 7.28 HCHO (formaldehyde) and 7.79$\pm$7.29 $CH_3$CHO (acetaldehyde) in Buchun, while recording 10.13$\pm$8.58 (HCHO) and 7.64$\pm$6.65 ($CH_3$CHO) in Kwanghwamoon. Their diurnal variation patterns showed significant increase of HCHO and $CH_3$CHO concentration in early afternoon, indicating an increase in secondary sources. Their concentrations however decreased in the nighttime, regardless of seasons. The strength of correlations between certain pairs such as (1) HCHO and CO and (2) $CH_3$CHO and CO were generally high during the winter months (0.64< r < 0.84), suggesting the possibility of similar source processes for HCHO, $CH_3$CHO and CO. On the other hand during the summer months, their correlations are frequently lower than winter months. We suggested that the complexity of source/sink processes during the summer period may reduce the correlations between aldehyde and CO.

• Ocean and Polar Research
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• v.34 no.3
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• pp.287-296
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• 2012

In the theory of source-driven abyssal circulation, the forcing is usually assumed to be steady source (deep-water formation). In many cases, however, the deep-water formation occurs instantaneously and it is not clear whether the theory can be applied well in this case. An attempt is made to resolve this problem by using a simple reduced gravity model. The model basin has large depth change compared for its size, like the East Sea, such that isobaths nearly coincide with geostrophic contours. Deep-water is formed every year impulsively and flows into the model basin through the boundary. It is found that the circulation driven by the impulsive source is generally the same as that driven by a steady source except that the former has a seasonal fluctuation associated with unsteadiness of forcing. The magnitudes of both the annual average and seasonal fluctuations increase with the rate of deep-water formation. The problem can be approximated to that of linear diffusion of momentum with boundary flux, which well demonstrates the essential feature of abyssal circulation spun-up by periodic impulsive source. Although the model greatly idealizes the real situation, it suggests that abyssal circulation can be driven by a periodic impulsive source in the East Sea.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.169-173
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• 2000

Seasonal distribution of ectomycorrhizal associations in various types of forest in a boreal forest in Manitoba. Canada was investigated. Alsohe relationship between ectomycorrhizal growth and pine pollen nutrients was examined. In four different forest stands, ectomycorrhizas tended to be lower in the spring than in the summer and fall samples. In addition. a mature jack pine (Pinus banksiana) stand showed higher mycorrhizal activities than a young jack pine stand. Growth of Suillus brevipes hyphae wa ts stimulated by additions of pollen representing mean pollen deposition in Mistik Creek study area after 30 and 70 days of growth with dextrose availability. This result suggests that the peak ectomycorrhizal activity is followed by pollen deposition in the study region and therefore, addition of pine and spruce pollen in early or middle of June in the boreal forest can be an important seasonal nutrient source for ectomycorrhizal growth.

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.23-32
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• 2012

The ionic composition of $PM_{2.5}$ samples was investigated by their datasets of cationic ($Na^+$, $NH_4^+$, $K^+$, $Mg^{2+}$, and $Ca^{2+}$) and anionic components ($Cl^-$, $NO_3^-$, and $SO_4^{2-}$) along with relevant environmental parameters collected from an urban monitoring site in Korea at hourly intervals in 2010. The mean (and SD) annual concentration of $PM_{2.5}$ was computed as 25.3 ${\mu}g\;m^{-3}$ with the wintertime maximum. In addition, sum concentrations (neq $m^{-3}$) of five cationic species (291) were slightly lower than 3 anionic species (308). Most cations exhibited the highest seasonal values in spring, while anions showed more diversified seasonal patterns. According to PCA, five major source categories were apparent with the relative dominance of secondary inorganic aerosols (SIA). The results of our study suggest consistently that the distribution of ionic constituents in an urban area is affected by the combined effects of both natural and anthropogenic processes.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.209-216
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• 2001

Dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 6 sampling sites in Pusan area from March, 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal distribution. Dustfall amount of regional variations were found in order of coastal zone, industrial zone, commercial zone, agricultural zone and residential zone, and seasonal total dustfall had higher concentrations during spring for 6.741 ton/${km}^2$/season, lower concentrations during summer for 1.989 ton/${km}^2$/season, and annual total concentration was 17.742 ton/${km}^2$/year. The regional distributions of enrichment factor show well-defined anthropogenic metals (Cd, Cu, Pb, and Zn) at industrial and agricultural zone, and contribution rate of soil particles were found in order of summer, fall, winter and spring. Factor loading effects of chemical composition of dustfall were found in order of road traffic emission source and combustion processed source, industrial activity source, soil source and marine source.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.631-642
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• 1998

Fall-out particles were collected by the modified British deposit gauges at 35 sampling sites in Suwon area from January to November, 1996. Twenty chemical species (Al. Ba, Cd, Cr, K, Pb, Sb, Zn, Cu, Fe, Ni, V, F-, Cl-, NO3-, 5042-, Na+, NH4+, Mg2+, and Ca2+) were analyzed by AAS and If. The purposes of this study were to estimate qualitatively various emission sources of the fell-out particle by applying multivariate statistical techniques such as factor analysis, multiple regression analysis, and discriminant analysis. During the study, outlier sites were determined by a z-score method. Cl-, Na+, Mg2+, and SO42- were highly correlated due to their common marine related source. Wind speed was the most influential factor for the deposition fluxes of the particle itself and all the chemical species as well. When applying the factor analysis, 8 source patterns were qualitatively obtained, such as marine source, soil source, oil burning source, Cr related source, tire source, Cd related source, agriculture source, and F- related source. As a result of the multiple regression analysis, we could suggest that some chemical compounds may possibly exist in the form of CaSO4, NaN03, NaCl, MgC12, (NH4)2SO4, NaF, and CaCl2 in the fall-out particles. Finally, spatial and seasonal classification study performed by a discriminant analysis showed th.at SO42-, Ca2+, Cl-, and Fe were dominant in the group of spatial pattern; however, SO42-, Cl-, Al, and V were in the group of seasonal pattern.