• Journal of Korean Society for Atmospheric Environment
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• v.27 no.5
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• pp.523-533
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• 2011

This study had the aim of characteristics of $PM_{10}$ in subway cabins. $PM_{10}$ was measured by times of day (rush and non rush hours) and seasons with real time $PM_{10}$ sampler on the subway cabins of line 7. Filter samples were collected for evaluation of their elemental composition as well as identification of major sources of $PM_{10}$ using a receptor model, PMF. $PM_{10}$ concentration were the highest in the winter season both in the rush and non rush hours at 152.8 ${\mu}g/m^3$, 90.2 ${\mu}g/m^3$ respectively. The $PM_{10}$ concentrations in rush hour were 30% higher compared to non rush hours. Based on the chemical information, the composition rare of inorganic elements was 52.5%, anions were 10.2% and others were 37.3%. Fe was the most abundant element and significantly correlated (p.0.01) with Mn (r=0.97), Ti (r=0.91), Cr (r=0.88), Ni (r=0.89) and Cu (r=0.88). Characterized $PM_{10}$ sources by PMF in the cabin were soil and road dust related sources (27.2%), railroad related sources (47.5%), secondary nitrate sources (16.2%) and a Cl-factor mixed with a secondary sulfate source (9.1%).

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.4
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• pp.8-15
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• 2015

The demand for environmental consideration is on the increase in civil engineering. This study focuses on the development of technology to reduce the use of carbonate cement and improve its performance by using a silicate mineral and hardening agents, and presents the test results for the demonstrative evaluation of the properties of the raw material. Highly active feldspar was used as a binder to augment the bonding of the carbonate cement, and their change in strength was observed after test piece construction with the addition of soluble hardening agent. The uniaxial compression strength of the test piece of the general Portland cement with the addition of 0.5% soluble hardening agent, showed an increase by 33% and that of the test piece of cement with the addition of 70% substituted with feldspar increased by 28%. The strength of viscous soil; classified as soft ground, showed an increase of a maximum of 1.7 times when it was mixed with cement and solidifier depending on the curing period. These tests confirmed that a soluble solidifier is effective for improving the strength of a cement binder and that the highly active feldspar can be used as a binder.

• Korean Journal of Medicinal Crop Science
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• v.3 no.3
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• pp.259-264
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• 1995

This study was carried out to find cultivation condition of peony in Euiseong district from 1994 to 1995. 1. Age distribution in cultivation of peony was from 30's to 50's and cultivated years was mainly from 5 years to 10 years, but there was more than 15 years 2. Cultivating area per house hold were 1300 pyeong average, there were moderate $400{\sim]1000$ pyeong and also those are occupied 22.6% more than 2000 pyeong. 3. The mothods of transplanting in Euiseong peony which Euiseong district was mostly divided peony but Yeongchen district used seedling stock. No. of sprout was mostly $3{\sim}4$ and planting time was mainly from Mid to Late of October. 4. The percentage of sterilization of soil and seedling stock was 77. 4%, in mulching by vinyl in tran­splanting 64. 5% in black vinyl and 25. 8% in white one. 5. Number of plant in peony planting was $3000{\sim}4000$ plant per l0a even more there was more than 8000 plant. 6. Chemical spraying time in peony field was 2 time in $1{\sim}2$ years cultivating, and $3{\sim}4$ time in $3{\sim}4$ years one. 7. Condition of fertilizer application in peony field was 40% in non-application, but $56.7{\sim}76.7%$ in 2 year to 3 years, and the time of fertilizer was mainly 3 time. 8. Drying time peony after havesting was from 12 to 24 hours by briquet stove and 24 hours by ma­chine of hot wind, also dry method of peony was mixed briquet stove and hot wind machine.

• Korean Journal of Environment and Ecology
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• v.8 no.1
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• pp.74-77
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• 1994

To examine the effects of gibberelin treatment on seed germination of five Viola species - Viola variegata, Viola dissecta var, chaerophylloides, Viola collina, Viola hirtipes and Viola manshrica - in Wonju district, pretreated seeds of five species were sowed on Jiffy strips with mixed soil(sand： peat moss： perlite： vermiculite, 1:1:1:1, v/v) in 25, May 1994. Seeds were soaked in 5, 25, 50ppm gibberelin solution and ground water during 24 hours. Seed germination rate was measured and compared among species and treatments. Seed germination rate of Viola hirtipes was differed higly significant among pretreatments, but those of other species did not significant at 5of level. In general GA$_3$pretreatment raised seed germination rate of 5 Viola species, and proper concentration of GA$_3$was 25~50ppm.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.471-481
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• 1995

The weed population dynamics as affected by contrasting conventional tillege (CT) and no-tillage (NT) practices with a minimum herbicide application was studied in Athens, Georgia, U.S.A. Common chickweed (Stellaria media) was the most common spring weed while johnsongrass (Sorghum halepense), sicklepod (Cassia obtusifolia), and pigweed (Amaranthus retroflexus) accounted for 89∼97％ of net production during summers of 1983 and 1984. Total weed production in summer of 1984 was 2∼5 times greater than that of 1983. Weed production was greater in NT plots than in CT plots in summer of 1983, but reverse was the case in summer of 1984. In spring, net production in NT plots was greater than that in CT plots, especially, in 1985. Species diversity was consistently higher in NT plots, but in the wet summer of 1984 the pattern was different, with higher diversity in CT plots. Weed species diversity was higher in the spring rye crop than in the summer grain sorghum crop. The larger but less diverse weed populations in summer of 1984 indicated that these populations experienced competitive exclusion. Under the favorable summer moisture conditions the three dominant species grew so vigorously and quickly as to exclude many less common species that were able to survive under the drier conditions in 1983. The three dominant species not only excluded other weeds in 1984 but also greatly reduced crop production. The perennial johnsongrass was equally successful, or even more so, in CT plots as in NT plots. Plowing did not kill johnsongrass rhizomes but tended to break them up, thus increasing the number of individual plants that appear after the plowing. It means that johnsongrass was not controlled by the plowing. In summer of 1983, a moderate amount of weedy growth was maintained with a minimum amount of gerbicide application in NT and CT plots. It is possible that a small mixed weed population would be beneficial by providing cover for predatory and parasitic arthropods, and by reducing soil temperature and moisture losses.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.5
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• pp.48-57
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• 2000

This paper is dealing with the fundamental properties of planting concrete, replacing the existing cover concrete on the roof of a building. This study is to find out the physical characteristics of the planting concrete and rearing characteristics of the grass throughout the modeling experimental materials. As the results of the experiment, the physical properties of planting concrete show the following results; when the paste to aggregate ratio is 0.2~ 0.4, voids volume : 30~17%, unit weight: 1,710~2,010kg/m3, compressive strength : 45~145kgf/$\textrm{cm}^2$, its pH is more than 11, but is reduced to the proper degree for planting after being neutralized. Kentucky bluegrass covered with planting concrete is grown well. The planting concrete used with blast furnace slag cement shows a better properties at the height, the width and the covering rate by 1.1cm, 0.5mm and 7%, respectively, than those used with ordinary portland cement. Also, the less the paste to aggregate ratio is, the better the plant grows. The orders of the effects of temperature control are as follows; the system of planting concrete with grass>the system of planting concrete without grass>the system of mixed soil>the existed roof system. In case, the planting concrete is placed to the roofs of buildings instead of normal concrete slab, and a number of favorable effect can be expected such as the improvement os environmental factors, the reduction of construction cost, the saving of energy and the reduction of environment load. The future research on the change of a variety of the aggregate conditions and the application of the practical structures should be made, and also the research of the endurance also be performed.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.483-490
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• 2005

At present around 50 companies have their own crushing plants, which manufacture rock into crushed sand, over around 350 different quarry throughout the nation. However, in most plants the stone dust sludge is left as it is in their plants so that they have difficulty to utilize. Furthermore, environmental pollution may be even caused due to dust generated when it is dried. Recycling is starting capturing the attention of the people working over the quarry due to the reasons described above. This research has studied in the quarters the usability as landfill liner of the stone dust sludge, which is industrial waste. We investigated what technological properties it would have after mixing the stone dust sludge with SM(sandy soil) first and then with blast furnace slag or reject ash, which is waste, and cement as the stabilizer. As the result of three tests; compacting test, strength test, and permeability test; to satisfy the regulatory guideline of the government that is the compress strength over 5 $kgf/cm^2$, the flexibility over 1 $kgf/cm^2$, and the permeability under $1.0{\times}10^{-7}cm/sec$ From this research, we could confirm that stone dust sludge would be used as waste landfill liner if it were mixed with other waste by the proper mixing ratio.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.179-184
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• 2003

In order to establish micropropagation system Anthurium andreanum 'Atlanta', dwarf type, shoots of A. andreanum were cultured on medium supplemented with cytokinin. Callus was formed from the base of shoots. high frequency callus induction was obtained on medium with 10.0mg/L BA or 10.0mg/L TDZ(thidiazuron) at more than 71.8%. The shoots were cultured on media with various combinations and concentrations of TDZ, BA and 2.4-D to enhance callus induction. Callus was induced at more than 72.6% and grew vigorously on media containing 10.0mg/L BA and 0.0∼0.5mg/L 2.4-D, or 1.0mg/L TDZ. Stimulation effects of cytokinin by 2.4-D did not occur in combined treatments of cytokinin and 2.4-D. Callus was cut into sections(7${\times}$10mm), and then cultured on media with BA alone or BA and 2.4-D to regenerate shoots and to stimulate the callus growth. Shoot regeneration and callus growth were effective on media with 10.0mg/L BA alone, or 10.0mg/L BA and 0.1mg/L 2.4-D. In combined treatments of BA and 2.4-D, stmulation effects of cytocinin by 2.4-D also did not occur. Callus growth was decreased, accordiong to increasing the concentration of 2.4-D. In cimbined treatments of TDZ and 2.4-D in shoot regeneration and callus proliferation, stimulated effects of cytokinin by 2.4-D did not occur entirely. Media with 0.5∼1.0mg/L TDZ ingibited the regeneration and rooting of shoots, and callus growth from callus sections. Addition of 2.4-D on medium with TDZ ingibited the regeneration and rooting of shoots, and callus growth. Rooted plantdts were acclimatized in greenhouse. The plantlets were survived more than 98% in soil of vermiculite alone or mixed perlite 1 and vermiculite 1.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.122-129
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• 2017

Objectives: Most of the $PM_{10}$ in subway stations is spread by the train-induced wind from the tunnels. Therefore, in order to improve air quality in subway stations, it is important to remove the $PM_{10}$ from the tunnels. After the installation of PSD (platform screen doors), the influence of train-induced wind and $PM_{10}$ at the platform has decreased, but is estimated to have increased in subway tunnels. This study was conducted to investigate the control of $PM_{10}$ in subway tunnels by applying a 500-fold diluted solution mixed with a humectant using a natural polymer. Methods: For this purpose, we tested the dust reduction effect in a laboratory and corrosion test and water pollution using fish and aquatic plants for the natural dust collecting agent. In the tunnel of a subway station, we used the natural dust collecting agent over 15 days. The study was carried out on $PM_{10}$ control during operation, which accounts for more than 70% of subway dust. Results: As results, the natural dust collecting agent exhibited an excellent dust control effect, and it was safe for water quality and soil. It showed the effect of controlling $PM_{10}$ in the subway tunnel by 49.5- 64.7% over 15 days. The use of the dust collecting agent for the control of $PM_{10}$ could be confirmed in the subway. Conclusion: It is necessary to clearly explain the major portions of chemical components contained in $PM_{10}$ to figure out the characteristics of $PM_{10}$ and to develop effective reduction measures to decrease the adverse effects of $PM_{10}$ in the subway.

• Journal of the Korean GEO-environmental Society
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• v.11 no.8
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• pp.25-32
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• 2010

Contamination of soil and groundwater by the compounds of hydrocarbon petroleum has been widely accepted as the main cause that harms the environments and health. To remove those pollutants, absorbing clothes, activated carbons, or oil-water separation devices with the gravity method are employed for treatment. However, those materials and devices cannot remove the emulsion pollutants despite of their efficiency for removing free products. Therefore, we investigated the problems which occur during the groundwater treatment for the highly concentrated suspended solid particles, which can be resulted from excavation, and to propose methods to remove TPH(Total Petroleum Hydrocarbon). After coagulation experiment with high molecular polymers, the concentration of SS(Suspended Solids) and COD(Chemical Oxygen Demand) turned to satisfy the groundwater quality criteria within 5 minutes while the concentration of TPH failed to meet the water quality standard of effluent. Consequently, the water quality criteria for effluent could not be met by single DAF(Dissolved Air Flotation) process. However all water quality criteria could be satisfied after 20 minutes when coagulation reactions are carried out simultaneously in the DAF reactor.