• Weed & Turfgrass Science
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• v.3 no.4
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• pp.342-346
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• 2014

The purpose of this experiment is for investigating how much the amino acid liquid fertilizer and composted liquid manure, culture microorganism effect on the breeding of grasses and knowing the extent of the thatch content through an analysis of the soil. For testing about soil chemical, the quality of grasses, and the extent of the thatch content in the soil, we cultivated 6 kinds of microorganisms having the effect of thatch dissolution and sprayed these 6 microorganisms with composted liquid manure and the amino acid liquid fertilizer on the place Creeping bentgrass have planted. This conduction started from June to October, 2012 and 2013 (The interval: 2 weeks). In the result of the turf growth, there is no big difference between soil chemical and trace element. And we can know Leaf Color Index, Chlorophyll Index and Root Length are almost same as among treatment. In conclusion, the mixing fertilization of culture microorganism and composted liquid manure is better effective than the traditional fertilization. And it can be expected the effect of the quality of grass and Thatch decomposition in soil.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.145-152
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• 2013

This study aimed to investigate the growth and physiological characters of Liriodendron tulipifera seedlings in responses to two different levels of elevated air temperature and $CO_2$ concentration. The seedlings were grown in environment-controlled growth chambers with two combinations of air temperature and $CO_2$ conditions: (1) $22^{\circ}C$ + ambient $CO_2$ $380{\mu}mol\;mol^{-1}$ and (2) $27^{\circ}C$ + $770{\mu}mol\;mol^{-1}$. Physiological characters such as growth, photosynthesis, and water use efficiency, were monitored for 85 days. The seedlings under the elevated treatment showed a greater amount of growth in tree height, compared with those under the control. Regarding the characteristics of assimilatory organs, the elevated treatment resulted in a greater amount of total leaf area, leaf unfolding, and dry weight per leaf area. No significant differences were found in photosynthesis capacity between the two treatments. The increase in water use efficiency with increased intercellular $CO_2$ partial pressure appeared overall lower in the seedling under the elevated treatment, compared with those under the control. The total leaf area of the seedlings under the elevated treatment was larger than that under the control, indicating a higher amount of photosynthesis. In addition, an increase of root growth was noted under the elevated treatment. A resistance mechanism of water stress may be attributed to a higher amount of organ growth as well as the tree height under the elevated treatment than the control.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.139-146
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• 2012

Stream ecosystems carry out significant functions such as water purification, especially denitrification. However, rapid landuse change since industrialization has altered ecological functions of streams. In this study, we aimed to investigate denitrification rates and their determinant factors in streams with different landuse patterns, and how denitrification rates vary with microtopology within streams. Ten fifth streams of each landuse were selected, and each stream was divided into four microtopological sites within streams - riparian zone, subsoil, and both head and tail parts of sand bars. In situ denitrification rates and physicochemical properties of soil were examined. Denitrification rates of agricultural, urban, and forest streams were $289.62{\pm}70.69$, $157.01{\pm}37.06$, $31.38{\pm}18.65mg$ $N_2O-N\;m^{-2}\;d^{-1}$ respectively. There were no significant differences in denitrification rates depending on microtopology, but the rates in riparian zone were the highest, and the rates in the head parts of sandbars were lower than those of tail parts. The determinant factors for denitrification rates included water temperature, silt and clay contents of soil, inorganic nitrogen, and organic carbon, and these factors all showed positive correlations with denitrification rates. Through this study, we find that landuse pattern in watershed region affects denitrification rates that is one of considerable functions of streams. In addition, estimation of denitrification rates taking into account for microtopology would contribute to developing ecological management and restoration strategy of streams.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.327-337
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• 2017

A continuous low temperature ($510^{\circ}C{\sim}530^{\circ}C$) pyrolysis experiment in a pilot-scale of 85.3 kg/hr was carried out by the mixed feedstock of half dried digested sewage sludge and waste plastics. As a result, the amount of pyrolysis gas generated was maximum 68.3% of input dry mass and scored $40.9MJ/Nm^3$ of lower heating value (LHV), and the percentage of air inflow caused by continuous pyrolysis was 19.6%. The oil was produced 4.2% of the input dry mass, and the LHV was 32.5 MJ/kg. The sulfur and chlorine contents, which could cause corrosion of the facility, were found to be 0.2% or more respectively. The carbide generated was 27.5% of the input dry mass which shows LHV of 10.2 MJ/kg, and did not fall under designated waste from the elution test. The concentration of carbon monoxide, sulfur oxides and hydrogen cyanide of emitted flu gas from pyrolysis gas combustion was especially high, and dioxin (PCDDs/DFs) was within the legal standards as $0.034ng-TEQ/Sm^3$. Among the 47 water pollutant contents of waste water generated from dry flue gas condensation, several contents such as total nitrogen, n-H extract and cyanide showed high concentration. Therefore, the merge treatment in the sewage treatment plants after pre-treatment could be considered.

• Analytical Science and Technology
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• v.10 no.3
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• pp.187-195
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• 1997

Chemically modified electrodes(CMEs) for Ag(I) were constructed by incoporating 1,5,9,13-tetrathiacyclohexadecane([16]-ane-$S_4$) with a conventional carbon-paste mixture composed of graphite powder and nujol oil. Ag(I) ion was chemically deposited onto the surface of the modified electrode with [16]-ane-$S_4$ by immersion of the electrode in the acetate buffer solution(pH=4.5) containing $5.0{\times}10^{-4}M$ Ag(I) ion. And then the electrode deposited with Ag(I) was reduced at -0.3V vs. S.C.E. Well-defined stripping voltammetric peaks could be obtained by scanning the potential to the positive direction. The CME surface was regenerated with exposure to 0.1M $HNO_3$ solution and was reused for the determination of Ag(I) ion. When deposition/measurement/regeneration cycles were 10 times, the response could be reproduced with relative standard deviation of 6.08%. In case of differential pulse stripping voltammetry, the calibration curve for Ag(I) was linear over the range of $5.0{\times}10^{-7}{\sim}1.5{\times}10^{-6}M$. And the detection limit was $2.0{\times}10^{-7}M$. Various ions such as Cd(II), Ni(II), Pb(II), Zn(II), Mn(II), Mg(II), EDTA, and oxalate(II) did not influence the determination of Ag(I) ion, except Cu(II) ion.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.3
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• pp.120-126
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• 2016

This study was carried out to examine the relationships between seasonal variations of soil $CO_2$ efflux rates and soil environmental factors in matured Pinus densiflora and Quercus variabilis stands in the Wola national experimental forests, southern Korea. Soil $CO_2$ efflux rates were measured monthly from March 2015 to February 2016. Mean soil $CO_2$ efflux rates during the study period were significantly higher in the Q. variabilis ($mean{\pm}standard$ error; $2.27{\pm}0.22{\mu}mol\;m^{-2}s^{-1}$) than in the P. densiflora ($1.63{\pm}0.12{\mu}mol\;m^{-2}s^{-1}$) stands. Mean soil water content and pH were also significantly higher in the Q. variabilis ($26.96{\pm}0.93%$, pH 5.19) than in the P. densiflora ($21.32{\pm}0.89%$, pH 4.87) stands, while soil temperature was not significantly different between the P. densiflora ($13.92{\pm}0.67^{\circ}C$) and in the Q. variabilis ($13.52{\pm}0.70^{\circ}C$) stands. $Q_{10}$ values were higher in the Q. variabilis (3.35) than in the P. densiflora (2.72) stands. The results indicate that soil $CO_2$ efflux rates in Q. variabilis stand could be more sensitive by the change of soil temperature compared with P. densiflora stand under a similar site environmental condition.

• Composites Research
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• v.30 no.2
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• pp.102-107
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• 2017

The preceramic polymer can realize a variety of complex ceramic structures that can not be obtained by conventional ceramic processes. Polycarbosilane, which is a typical preceramic polymer, can control the molecular structure, molecular weight and molecular weight distribution for preparing complex morphology and microstructure of SiC ceramics, including SiC fiber. In this paper, synthesis and molecular structure control technique of polycarbosilane is explained. The silicon carbide fiber prepared by melt spinning, stabilization and heat treatment, and ceramic fiber composites technology made by PIP process are also discussed. In addition, we introduce an example of the development of a complex silicon carbide material such as a silicon carbide hollow fiber having a nanoporous structure.

• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.99-109
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• 2007

Cellulomanas sp. CS 1-1 was studied for its morphological, physiological and biochemical characteristics, together with DNA homology and fatty acid pattern to elucidate its taxonomical position in the species level. Colony morphology of CS1-1 exhibited circular form, opaque, convex, entire edge and pale yellow. Cells were of rod with the size of $0.3{\sim}0.5{\times}0.8{\sim}1.2{\mu}m$, while coryneforms were formed at the early stage of culture. D-ribose, raffinose, rhamnose, acetate, propionate, L-lactate, D-gluconate, aspartate and proline were not utilized as a sole source of carbon, whereas saccharose, arabinose, and amlyose were utilized. Biochemical characteristics of CS1-1 were Gram positive, catalase positive, oxidase negative, nonmotile, facultative anaerobic, mesophilic and G+C content of 74.7 mol %. The major fatty acid and menaquinone were 12-methyltetradecanoic acid(anteiso-$C_{15:1}$) and MK-$9(H_4)$, respectively. These results were correspondent with the characteristics reported for member of the genus Cellulomonas. The strain CS 1-1 exhibited a high level of DNA homology as 70% with C. uda ATCC491, compared to those of 54~59% with C. fimi ATCC 15724, 46~48% with C. biazotea, C. gelida and C. bibula. Finally, strain CS1-1 could be classified as a novel species belongs to C. uda.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.343-352
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• 2016

It has been estimated that the Earth has nearly 1.688 trillion barrels of crude oil, which will last 53.3 years at current extraction rates. The organization of petroleum exporting countries (OPEC) group forecasted that the oil prices will not jump to triple-digit territory within a decade, but it can quickly increase as the political issue for reducing oil production appears. With the potential of serious shortage of conventional hydrocarbon resources, the heavy oil, one of unconventional hydrocarbon resources including oil sand and natural bitumen has attracted worldwide interest. The heavy oil contains heavy hydrocarbon compounds, commonly called as resins and asphaltenes, with long carbon chains more than sixty carbon atoms. The high content of heavier fraction corresponds with the high molecular weight, viscosity, and boiling point. Physicochemical properties of residues from vacuum distillation of conventional oil, referred to as vacuum residues (VR) were similar to those of heavy oil. For the development of heavy oil reserves, reducing the heavy oil viscosity is the most important. In this article, commercially employed aquathermolysis processes and their application to VR upgrading are discussed. VR contains transition metals such as Ni and V, but these metals should be eliminated in advance for further refining. Recent studies on demetallization technologies for VR are also reviewed.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.69-76
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• 2008

To estimate removal ability of harmful gas by charcoal, we carbonized Red oak (Quercus mongolica Fischer) wood and Larch (Larix leptoepis) bark at $300^{\circ}C$, $600^{\circ}C$ and $900^{\circ}C$ for 1 hour. Gas removal ratios was increased with carbonization temperature but there is no difference between wood and bark charcoal. In the case of bad smell and VOC gas, woody charcoal including bark charcoal carbonized at $300^{\circ}C$ showed low removal ratio, less than 50%, whereas woody charcoals which was carbonized at more than $600^{\circ}C$ reached almost 100% removal ratio to bad smell gas such as trimethylamine, methymercaptan, hydrogen sulfide, and to VOC such as benzene, toluene, xylene in $5{\ell}$ tedler bag with each gas of 100 ppm. It was thought that because charcoals carbonized at high temperature, for example, $600^{\circ}C$ or $900^{\circ}C$ have enough specific surface area to adsorb gas of 100 ppm. Moreover these charcoals rapidly removed almost gas in 10 minutes. However, acetylene, $SO_2$ and $NO_2$, charcoals which was carbonized more than $600^{\circ}C$ and which showed high removal ratio had low gas removal ratio of 40% at even 4 hours adsorption. It was concluded that adsorptive ability of woody charcoal was mainly influenced with carbonizing temperature, so that different charcoals carbonized at different temperature brings different gas removal ratio because these charcoals have not only different physical factor such as specific surface area but different chemical characteristic such as functional group, expected.