• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.268-276
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• 2007

Urban atmosphere may play as a harbinger for the future climate change with respect to temperature and $CO_2$ concentration. The Seoul metropolitan area is unique in rapid urbanization and industrialization during the last several decades, providing a natural $CO_2$ dome with increased temperature. This study was carried out to evaluate the feasibility of using the urban-rural environmental gradient in replacement of the IPCC mid-term scenario (after 30-50 years). For this, we measured atmospheric $CO_2$ concentration and air temperature at three sites with different degree of urbanization (Seoul, Suwon, and Icheon). Results from 11-month measurement can be summarized as follows: (1) The annual mean $CO_2$ concentration across 3 sites was in the order of Seoul (439 ppm) > Suwon (419 ppm) > Icheon (416 ppm), showing a substantial urban-rural environmental gradient. (2) The diurnal fluctuation in $CO_2$ concentration was greater in summer than in winter, showing the effect of photosynthesis on local $CO_2$ concentration. (3) The daily maximum $CO_2$ concentration was observed at 0500 LST in spring and summer, 0800 LST in autumn, and 0900 LST in winter, showing the sunrise-time dependence. (4) The observed hourly maximum $CO_2$ concentration averaged for the whole period was 446 ppm in Seoul at 0700 LST, while the minimum was 407 ppm in Suwon at 1500 LST. (5) Compared with the background atmospheric concentration of $CO_2$ in Anmyeon-do (377.4 ppm annual mean), $CO_2$ concentration of the study sites was higher by 14% in Seoul, by 10% in Suwon, and by 9% in Icheon. The observed $CO_2$ concentration in Seoul reached already 98% of the 2030-2040 projection (450 ppm) and 80% of the 2040-2050 projection (550 ppm) under the IPCC BAU scenario, showing a feasibility of using the $CO_2$ dome of Seoul as a natural experimental setting for the mid-term climate change impact assessment.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.145-154
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• 2004

Purpose : To examine whether a synthetic bile acid derivatives (HS-1200) sensitizes the radiation-induced apoptosis in human breast cancer cells (MCF-7) and to investigate the underlying mechanism. Materials and Methods : Human breast cancer cells (MCF-7) in exponential growth phase were treated with HS-1200 for 24 hours at 37$^{\circ}C$ with 5$\%$ CO$_{2}$ in air atmosphere. After removal of HS-1200, cells were irradiated with 2$\~$8 Gy X-ray, and then cultured Ii drug-free media for 24-96 hours. The effect of radiation on the clonogenicity of MCF-7 cells was determined with clonogenic cell survival assay with 16$\mu$M of HS-1200. The induction of apoptosis was determined using agarose gel electrophoresis and Hoechst staining. The expression level of apoptosis-related molecules, such as PARP, Bax, Bcl-2, Bak and AIF, were assayed by Western blotting analysis with 40$\mu$M of HS-1200 combined with 8 Gy irradiation. To examine the cellular location of cytochrome c, bax and AIF immunofluorescent stainings were undertaken. Results : Treatment of MCF-7 cells with 40$\mu$M of HS-1200 combined with 8 Gy irradiation showed several changes associated with enhanced apoptosis by agarose gel electrophoresis and Hoechst staining. HS-1200 combined with 8 Gy irradiation treatment also enhanced production of PARP cleavage products and increased Bax/Bcl-2 ratio by Western blotting. Loss of mitochondrial membrane potential ($\Delta$$\psi$$_{m}$) and increased cytochrome c staining indicated that cytochrome c had been released from the mitochondria in HS-1200 treated cells. Conclusion : We demonstrated that combination treatment with a synthetic chenodeoxycholic acid derivative HS-1200 and irradiation enhanced radiation-induced apoptosis of human breast cancer cells (MCF-7). We suggest that the increased Bax/Bcl-2 ratio In HS-1200 co-treatment group underlies the increased radio sensitivity of MCF-7 cells. Further futures studies are remained elusive.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.881-897
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• 2019

We reconstructed and digitized the National Institute of Fisheries Science (NIFS) Serial Oceanographic observations (NSO) and Coastal Oceanographic observations (NCO) data attained prior to 1961 through historical oceanographic observation data rescue projects. Increasing trends of long-term sea surface temperature (SST) were shown from the NSO data of 21 available stations for the past 80 to 92 years. In general agreement with previous research results used in the data of the past 50 years, we calculated the rate of temperature rise. As a result of analyzing the spatial distribution of SST change rate in the Korean of shore region using selected oceanographic data, the West Sea and South Sea showed a higher tendency of temperature rise in the offshore area than in the coastal area. However, unlike the results of previous studies, the East Sea (Gangwon Line and Ulsan Line) showed a lower water temperature rise than the coastal stations. Annual fluctuations of NCO's SST data from 1989 to 1998 for three stations representing the East Sea, South Sea, and West Sea, (Jumunjin, Geomundo and Budo, respectively) revealed that the East Sea showed the highest SST increase for the 10 years. The increases were 1.63 ℃ at Jumunjin, 1.16 ℃ at Geomundo, and 0.79 ℃ at Budo. As a result of the investigation, it can be concluded that SST is repeatedly rising and falling with a period of 3 ~ 6 years. Especially, since the 1980s, most of the stations show positive anomalies of SST. Lastly, to understand ocean_atmosphere interactions, we analyzed the correlations between SST of the NCO stations and air temperature around them and the results were 0.76 for the South Sea (Geomundo), 0.34 for the West Sea (Budo), and 0.32 for the East Sea (Jumunjin) with the highest correlation in the South Sea.

• Resources Recycling
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• v.9 no.4
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• pp.16-27
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• 2000

In order to produce raw material powder of advanced magnetic material by spray roasting process, newly modified spray roasting system was developed in this work. In this spray roasting system, raw material solution was effectively atomized and sprayed into the reaction furnace. Also, uniform temperature distribution inside reaction furnace made thermal decomposition process fully completed, and produced powder was effectively collected in cyclone and bag filter. This system equipped with apparatus which can purify hazard produced gas. In this study complex acid solution was prepared by dissolution of mill scale and ferro-Mn into the acid solution, and the pH of this complex acid solution was controlled about to 4. It was conformed that mill scale and ferro-Mn containing a lot of impurities such as $SiO_2$, P and Al could be used as raw material by reducing the impurities content of complex acid solution below 20 ppm. Complex oxide powder of Fe-Mn system was produced by spraying purified complex acid solution into the spray roaster through nozzle, and the variations of produced powder characters were studied by changing he reaction conditions such as reaction temperature, the injection velocity of solution and air, nozzle tip size and concentration of solution. The morphology of produced powder had spherical shape under the most experimental conditions, and concentration of solution. The morphology of produced powder has spherical shape under the most experimental conditions, and the composition and the particle size distribution were almost uniform, which tells the excellence of this spray roasting system. The grain size of most produced powder was below 100 nm. From the above results, it will be possible to produce ultra fine oxide powder from the chloride of Fe, Mn, Ni, Cu and rare earth by using this spray roasting system, and also to produce ultra fine pure metal powder by changing reaction atmosphere.

• 한국해양학회지
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• v.30 no.2
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• pp.91-115
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• 1995

Air-sea heat fluxes in the East Sea were estimated from the various ship's data observed from 1961 to 1990 and the JMA buoy #6 data from 1976 to 1985. The oceanic heat transport in the sea was also determined from the fluxes above and the heat storage rate of the upper layer of 200m from the sea surface. In winter, The incoming solar radiation is almost balanced with the outgoing longwave radiation. but the sea loses her heat through the sea surface mainly due to the latent and sensible heat fluxes. The spatial variation of the net surface heat flux is about 100 Wm/SUP -2/, and the maximum loss of heat is occurred near the Tsugaru Strait. There are also lots of heat losses in the southern part of the East Sea, Korea Strait and Ulleung Basin. Particularly, the heat strong loss in the south-western part of the sea might be concerned with the formation of her Intermediate Homogeneous Water. In summer, the sea is heated up to about 120∼140 Wm/SUP -2/ sue to strong incoming solar radiation and weak turbulent heat fluxes and her spatial variation is only about 20 Wm/SUP -2/. The oceanic heat flux is positive in the southeasten part f the sea and the magnitude of the flux is larger than that of the net surface heat flux. This shows the importance of the area. In the southwestern part of the sea, however, the oceanic heat flux is negative. This fact implies cold water inflow, the North Korean Cold Water. The sigh of net surface heat flux is changed from negative to positive in March and from positive to negative in September. The heat content in the upper surface 200 m from the sea surface reaches its minimum in March and maximum in October. The annual variation of the net surface heat flux is 580 Wm/SUP -2/ in southwestern part of the sea. The annual mean values of net surface heat fluxes are negative, which mean the net heat transfer from the sea to the atmosphere. The magnitude of the flux is about 130 Wm/SUP -2/ near the Tsugaru Strait. The net surface fluxes in the Korea Strait and the Ulleung Basin are relatively larger than those of the rest areas. The spatial mean values of surface heat fluxes from 35$^{\circ}C$ to 39$^{\circ}$N are 129, -90, -58, and -32 Wm/SUP -2/ for the incoming solar radiation, latent hear flux, outgoing longwave radiation, and sensible heat flux, respectively.

• Journal of the Korean earth science society
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• v.42 no.5
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• pp.536-555
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• 2021

Sea-surface wind is an important variable in ocean-atmosphere interactions, leading to the changes in ocean surface currents and circulation, mixed layers, and heat flux. With the development of satellite technology, sea-surface winds data retrieved from scatterometer observation data have been used for various purposes. In a complex marine environment such as the Korean Peninsula coast, scatterometer-observed sea-surface wind is an important factor for analyzing ocean and atmospheric phenomena. Therefore, the validation results of wind accuracy can be used for diverse applications. In this study, the sea-surface winds derived from ASCAT (Advanced SCATterometer) mounted on MetOp-A/B (METeorological Operational Satellite-A/B) were validated compared to in-situ wind measurements at 16 marine buoy stations around the Korean Peninsula from January to December 2020. The buoy winds measured at a height of 4-5 m from the sea surface were converted to 10-m neutral winds using the LKB (Liu-Katsaros-Businger) model. The matchup procedure produced 5,544 and 10,051 collocation points for MetOp-A and MetOp-B, respectively. The root mean square errors (RMSE) were 1.36 and 1.28 m s^-1, and bias errors amounted to 0.44 and 0.65 m s^-1 for MetOp-A and MetOp-B, respectively. The wind directions of both scatterometers exhibited negative biases of -8.03° and -6.97° and RMSE values of 32.46° and 36.06° for MetOp-A and MetOp-B, respectively. These errors were likely associated with the stratification and dynamics of the marine-atmospheric boundary layer. In the seas around the Korean Peninsula, the sea-surface winds of the ASCAT tended to be more overestimated than the in-situ wind speeds, particularly at weak wind speeds. In addition, the closer the distance from the coast, the more the amplification of error. The present results could contribute to the development of a prediction model as improved input data and the understanding of air-sea interaction and impact of typhoons in the coastal regions around the Korean Peninsula.

• Clean Technology
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• v.25 no.1
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• pp.81-90
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• 2019

A dielectric barrier discharge (DBD) plasma reactor packed with $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was used for the dry ($CO_2$) reforming of propane (DRP) to improve the production of syngas (a mixture of $H_2$ and CO) and the catalyst stability. The plasma-catalytic DRP was carried out with either thermally or plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst at a $C_3H_8/CO_2$ ratio of 1/3 and a total feed gas flow rate of $300mL\;min^{-1}$. The catalytic activities associated with the DRP were evaluated in the range of $500{\sim}600^{\circ}C$. Following the calcination in ambient air, the ${\gamma}-Al_2O_3$ impregnated with the precursor solution ($Ni(NO_3)_2$ and $Ce(NO_3)_2$) was subjected to reduction in an $H_2/Ar$ atmosphere to prepare $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst. The characteristics of the catalysts were examined using X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDS), temperature programmed reduction ($H_2-TPR$), temperature programmed desorption ($H_2-TPD$, $CO_2-TPD$), temperature programmed oxidation (TPO), and Raman spectroscopy. The investigation revealed that the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst exhibited superior catalytic activity for the production of syngas, compared to the thermally reduced catalyst. Besides, the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was found to show long-term catalytic stability with respect to coke resistance that is main concern regarding the DRP process.

• Cross-Cultural Studies
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• v.44
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• pp.211-237
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• 2016

This paper seeks to explore the new relationship between music and poetry established in the beginning of the Modern Era. This was a period when reading silently was the dominant culture rather than reading aloud and orality was limited due to the emergence of literacy and print culture. A poet sensitive to the characteristics of the period, $Mallarm{\acute{e}}$ created his own concept of music and new creative principles of poetry from it. We analyze his "Divigation" and letters, in particular, the "Crisis of vers", "Music and Literature", "Mystery in the letters", and "About the book." Firstly, $Mallarm{\acute{e}}$ connects music with the mystery and the sacred: the mystery surrounds the music and the music is oriented with the sacred. The sanctity is that of the human race and has existed within humans since the beginning. Transposing the characteristics of this music to the poetry is his first creative principle of poetry. However, $Mallarm{\acute{e}}$ called music a totality of relationships that exist between objects without reducing the dimension to only the instruments or the sound. His definition is abstract, regarding music as a complete rhythm, the atmosphere and the air. Secondly, we have the question of how to realize music in a poem. As the music is surrounded by the mystery, $Mallarm{\acute{e}}$ can transpose the sacred to a poem in mysterious ways. This leads to his second principle of poetry: make a poem as a structure. In other words, 'musically', based on the disappearance of real objects and the initiative of the poet, he created a structure with only the words. We can create an acoustic structure but $Mallarm{\acute{e}}$ created a visible structure to overcome the incompleteness of the sound of a word in the diffusion of print culture. In this manner, the use of silence as much as sound and the use of visual as much as aural components were introduced in poetry as important motifs and the essentials of creation. This new relationship between poetry and music and the creative principles drawn from it appear to be the areas to which attention should be focused in the research of poetry.

• Particle and aerosol research
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• v.14 no.4
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• pp.153-169
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• 2018

To identify a variety of organic compounds in the ambient aerosols, the two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC) system (2DGC) has been applied. While 2DGC provides more peaks, the amount of the generated data becomes huge. A two-step approach has been proposed to efficiently interpret the organic aerosol analysis data. The two-dimensional 2DGC data were divided into 6 chemical groups depending on their volatility and polarity. Using these classification standards, all the peaks were subject to both qualitative and quantitative analyses and then classified into 8 classes. The aerosol samples collected in Seoul in summer 2013 and winter 2014 were used as the test case. It was found that some chemical classes such as furanone showed seasonal variation in the high polarity-volatile organic compounds (HP-VOC) group. Also, for some chemical classes, qualitative and quantitative analyses showed different trends. Limitations of the proposed method are discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.576-585
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• 1991

General procedures of seed preparation as conventional guide had been established in China before most of Korean literature documented them. ‘Chwijongbeob’ (method of seed select) was to select good quality of seeds and to discard the rest. In ‘Seonjongbeob’ (method of seed grading) although China employed only ‘Sooseonbeob’ (method of seed select with water), but seeds were selected in order of selection of seeds by winds, selection of seeds by sieve and selection of seed with water in Korea. As compared with the recent techniques, those methods were perfect techniques for selection of good quality seeds of rice, except for method of seed selection by salt water was developed. The method for measurement of seed moisture, and for measurement of melted snow, spoiled urine and extracted juice by boiling water with the bone of livestock were originated from ancient China. The farming books in Korea were more or less followed the above methods. However, these techniques were complicated and impractical interms of validity and rationality. Also, it is judged that these tchniques are more appropriate in dry areas and alkaline soil of China rather than in Korean conditions. The plowing is a work to begin farming, and is operated for air ventilation between atmosphere and earth. Also, this techniques was adopted in the farming books from the early to the late Chosun dynasty without changes. Fields were deep-plowed in the first, in fall (or in spring) and for cultivation, and were shallow -plowed in the second, in spring (or in summer) and in intertillage. The former was for water reserve and land preparation, and the later was for weed control with intertillage. However, plowing in fall which was different from fallowing in dry areas, was recommended in Korea (Jikseol). but was not practiced in Sejongsilrok. This was changed with time, and plowing for cultivation in Korea was interrelated with use of green manure crops, method of plowing of upseting plough, method of manure practice and sometimes dry plowing. In addition, until the 15th century method of using a kind of plowing-tool made of log as farm tools was created to support reclamation for enlargement of farm land in mountaineous and coastal areas. For desolate farm lands by many internal and external disturbances, one tried to recover yield ability by increasing labor productivity from the 17th or 18th century. To do this, ‘Banjongbeob’ (culture method by upset plowing weed control) and ‘Hwanubeob’(culture method by firing weed control) which were cultural methods of ancient China were readapoted but the results were not clearly informed. Also, the reality of those was reexamined in the end of the Chosun dynasty.