• Journal of Korean Society for Atmospheric Environment
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• v.2 no.1
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• pp.11-21
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• 1986

The study was performed to investigate the effects of gaseous imission of sulfur dioxide and hydrogen fluoride on the growth of rice plant under stressed field conditions. The plants were cultivated in normal paddy fields where are 88 industrial plants operating with 285 smoke stacks emitting pollutants. There has been a number of reported studies (1, 3, 11, 19, 20) which deal with rice plant damages by air pollution under a simulated exposure experimental condition. Furthermore, these experiments were conducted to examine effects of a single pollutant on the plant. Furthermore, these experiments were conducted to examine effects of a single pollutant on the plant. In korea, however, there is no study reported in literature with respect to the in-situ dose-response relationship between rice pant reduction in yields and air pollution. This study is specifically dealt with multiple effects of sulfur dioxde and hydrogen fluoride on various plant growth indicators such as leaf damage, culm height, weight of grain, panicles per hill, spikelets per panicle and percent fertility.It appears that there is a good correlation between ambient concentrations of sulfur oxides and sulfur contents found in leaves with an average correlation coefficient of 0.868 within a 1% significance level. It is interesting to note that a better multiple correlation was found between percent leaf damage and sulfur and fluoride contentd found in leaf with a significance of 1% level. The yearly correlation coefficient ranges from 0.963 to 0.987 with an average being 0.971. It is, therefore, believed that a percent leaf damage may serve as a single indicator of pollutional damages to rice plant cultivating in fields. Regarding other factors to the diminution of rice plant growth in polluted atmosphere, it appears that a significant correlation to culm length and dry weight of grain with a 1% significance level whereas T/R ratio has a good correlation with lead damage within 5% significance level. An evaluation of data observed has demonstrated that both panicles per hill and percent fertility are significantly affected by air pollutants. As expected, hydrogen fluoride has more effects than sulfur oxide. It is, however, interesting to note that spikelets per panicles has slightly been affected while no indication of effects on 1000-grain-weight has been observed. This may lead to a conclusion that a reduction in yield of rice under polluted field conditions may have more been caused by the diminution of panicles per hill and percent fertility rather than by the diminution of spikelets per panicle and grain weight.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.522-526
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• 2009

The catalytic oxidation of 1,2-dichloribenzene (1,2-DCB) and simultaneous catalytic reduction of nitrogen oxides over the single catalyst has been investigated over various metals (Ru, Mn, Co and Fe) supported on $Al_2O_3$ and $CeO_{2}$. The activity of the different catalysts for catalytic oxidation of 1,2-dichloribenzene depended on the used metal, Ru/Co/$Al_2O_3$, Mn-Fe/CeO2 and Cr/$Al_2O_3$ (commercial catalysts) being the most actives ones. In the catalytic oxidation of chlorobenzene (CB), Ru/Co/$Al_2O_3$ is better than Pt-Pd/$Al_2O_3$, which is the well-known catalyst good for VOC oxidation. Furthermore, it has a good durability on the deactivation by $Cl_2$ and sulfur. For nitrogen oxides (NOx) removal, NOx conversion was 70% at $260^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.22-28
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• 2011

With the increasing cultivation of acid-loving plants such as blueberries, the artificial acidification of soils is frequently required. This research was conducted to determine the application rates of elemental sulfur (S) required in the soil acidification for blueberry cultivation. Laboratory incubation experiment was conducted to acidify three arable soils (pH 6-7) of different texture to pH 4.5-5.0 by the addition of varying amounts of elemental S. All rates of elemental S addition reduced soil pH, although the efficacy of acidification was related to the application rate and soil characteristics. pH reduction was slow in sandy loam soil, and the final equilibrium pH was obtained after 60, 43, and 30 days of incubation in sandy loam, loam, and silty clay, respectively. Although the final pHs obtained after 93 days of incubation were not significantly different among the three soils, the equilibrium pH was relatively higher in soil of higher clay content in the application rates of 1.5-2.0 g S $kg^{-1}$ soil. The estimated amounts of elemental S required in lowering pH to 4.5-5.0 were 0.59-1.01, 0.67-1.03, and 0.53-0.88 g S $kg^{-1}$ for sandy loam, loam, and silty clay, respectively. The lowest estimated amount of elemental S in the acidification of silty clay soil was attributable to the low organic matter content. For clay soils containing optimum level of organic matter, the application rates of elemental S should be much higher than those values estimated in this research. Soil acidification did not significantly increase the available concentrations of Ca, Mg and K. Extractable Cu and Zn was not greatly affected by the acidification, but extractable Fe, Mn, and Al in the acidified soils were higher than those found in non-acidified soils. Such increases in solubility are attributable to the dissolution of oxides and hydroxides of the elements.

• Plant Journal
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• v.15 no.1
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• pp.38-44
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• 2019

This research is an experimental investigation to find the desirable pH of slurry in the desulfurization absorber for a 1000 ㎿ coal fired power plant, operating in compliance with the Air Environmental Conservation Act and the plant's internal regulations. In case the average sulfur dioxide concentration in inflow flue gas, ${\bar{C\;in}}$ [ppm] changed to 500 ppm, 550 ppm, 600 ppm and 635 ppm after fixing inflow flue gas flow rate, generator output, pressure drop in the absorber, and oxidation air flow rate, the desirable pH of the slurry in the absorber, was 5.0, 5.2, 5.3 and 5.4. Thus, it is recommended that the desirable pH of slurry is calculated using the correlation equation, $RpH=0.0018{\times}{\bar{C\;in}}+4,2031$ when the average sulfur dioxide concentration in the inflow flue gas is in the range of 500 ppm to 635 ppm.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.265-266
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• 2014

Due to global economic growth, there is an increasing need for energy. Fossil fuels will continue to dominate the world energy supplies in the 21st century and coal will play a significant role. Since coal is one of the most important fossil fuels in the world, coal gasification technology appears to be an inevitable choice for power and chemicals production and has a leading place in Clean Coal Technology (CCT). The most eminent environmental advantage of coal gasification lies in its inherent reaction features that produce negligible sulfur and nitrogen oxides, as well as other pollutants in a reducing atmosphere. The gasifier was operated for a throughput of 1.0 ton & 10.0ton coal per day at pressures of 1~20Bar. Gasification was conducted in a temperature range of $1,100{\sim}1,450^{\circ}C$.

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.43-47
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• 2003

The desorption characteristics of NaY zeolite, of which Si/Al ratio is 2.36, was measured at 25${\circ}$C and 150${\circ}$C so as to be used practically as a adsorbent for separation of sulfur oxides from flue gas, for which adsorption and desorption cycles at 25${\circ}$C were repeated four times and that at 150${\circ}$C was done one time. As a result it took 30.8 at 150${\circ}$C and 164.1 minutes in average at 25${\circ}$C to reach equilibrium condition. It means that regeneration of the NaY zeolite can be done below 150${\circ}$C so that zeolite can be used for flue gas desulfurization.

• Transactions on Electrical and Electronic Materials
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• v.2 no.2
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• pp.5-15
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• 2001

The experiment established optimal conditions for over-carbonization. With the use of the electron microscopy and X-ray phase analysis the regularities of carbon deposit formation in process of methane and propane pyrolysis on the zeolites, Kazakhstan natural clays, chrome and bauxite sludge containing metal oxides of iron subgroup, have been studied. In process of over-carbonization the trivalent iron was reduced to metal form. In addition, the carbon tubes of divers morphology had been impregnated with ultra-dispersed metal particles. The kinetic parameters of carbon formation in process of methane decomposition on the zeolite - CoO mixture surface were investigated by method of thermo-gravimetric analysis. The morphology and structure of formed carbon fibrils, with the metal particles fixed at their ends, have been investigated, the formation of branched carbon fibrils pattern, so called octopus, being found. Also, the walnut shells and grape kernel carbonization, their immobilization by the cells of selective absorption of heavy metal and sulfur dioxide ions have been studied. The example of metal-carbon composites used as adsorbents for wastewater purification, C$_3$- C$_4$ hydrocarbon cracking catalysts and refractory materials with improved properties have been considered.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.185-186
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• 2001

Recently, industrial activities have increased atmospheric concentration of sulfur and nitrogen oxides, resulting in acidification in the environments. In addition, acidification accelerates the mobilization of metals that are toxic to fish and increases their concentrations in the aquatic environment. Increased metals may interfere with reproductive physiology in fish. Al and Cd are such metals that impaired the preduction of Vitellogenin (VTG), a egg yolk precursor proteins. (omitted)

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.436-440
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• 2009

This study demonstrates the use of a chemical lung containing potassium superoxide to convert carbon dioxide in air to oxygen. In order to reduce its extremely high reactivity, potassium superoxide was first mixed with calcium hydroxide and then combined at various ratios with polysiloxane. Silicone polymer used here served as both a water repellent and the polymer matrix. In general, the amount of carbon dioxide captured as well as that of oxygen produced increased as the proportion of potassium superoxide in the chemical lung increased. FT-IR spectroscopy revealed that the Si-O bond in chemical lung appeared at $1,050cm^{-1}$ and absorbance of chemical lung containing higher amounts of silicone was higher than that of chemical lung containing lower amounts. These results indicate that such a chemical lung may also be a useful sorbent for other acid gases, such as sulfur oxides and nitrogen oxides.

• Journal of Environmental Science International
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• v.26 no.1
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• pp.67-78
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• 2017

Combustion of ethanol (EtOH) at low temperatures has been studied using titania- and silica-supported platinum nanocrystallites with different sizes in a wide range of 1~25 nm, to see if EtOH can be used as a clean, alternative fuel, i.e., one that does not emit sulfur oxides, fine particulates and nitrogen oxides, and if the combustion flue gas can be used for directly heating the interior of greenhouses. The results of $H_2-N_2O$ titration on the supported Pt catalysts with no calcination indicate a metal dispersion of $0.97{\pm}0.1$, corresponding to ca. 1.2 nm, while the calcination of 0.65% $Pt/SiO_2$ at 600 and $900^{\circ}C$ gives the respective sizes of 13.7 and 24.6 nm when using X-ray diffraction technique, as expected. A comparison of EtOH combustion using $Pt/TiO_2$ and $Pt/SiO_2$ catalysts with the same metal content, dispersion and nanoparticle size discloses that the former is better at all temperatures up to $200^{\circ}C$, suggesting that some acid sites can play a role for the combustion. There is a noticeable difference in the combustion characteristics of EtOH at $80{\sim}200^{\circ}C$ between samples of 0.65% $Pt/SiO_2$ consisting of different metal particle sizes; the catalyst with larger platinum nanoparticles shows higher intrinsic activity. Besides the formation of $CO_2$, low-temperature combustion of EtOH can lead to many other pathways that generate undesired byproducts, such as formaldehyde, acetaldehyde, acetic acid, diethyl ether, and ethylene, depending strongly on the catalyst and reaction conditions. A 0.65% $Pt/SiO_2$ catalyst with a Pt crystallite size of 24.6 nm shows stable performances in EtOH combustion at $120^{\circ}C$ even for 12 h, regardless of the space velocity allowed.