• Applied Biological Chemistry
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• v.38 no.5
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• pp.440-446
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• 1995

In order to select the proper formulation of newly developed herbicide Cyhalofop-butyl{n-butyl-(R)-2-[4-(2-fluro-4-cyanophenoxy)phenoxy]propionte} to Echino-chloacrus-galli(L)P. Beaw. several formulations were made and tested by biological assay. Weed control of wettable powder formulated with two adjuvants on E. crus-galli showed higher effect as compared with the formulation made without adjuvants. Higher concentration of adjuvants resulted in higher absorption and higher weed control on E. crus-galli. However, adhesional force of wettable powder applied to leaf surface was not positively correlated to the amount of herbicide absorption. The weeding effect and amount of herbicide absorbed on E. crus-galli were higher by emulsifiable concentrateformulations with different HLB and non ionic surfactants as compared with wettable powder formulations. The higher adhesional force and higher absorption of herbicide on E. crus-galli were obtained from microemulsion than the others. Granulization of the herbicide with appropriate adjuvants in a form of resurfacing on the submerged water gave rise to a good weeding effect and believed to be a possible promising formulation.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.646-653
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• 2012

We studied the economic evaluations on Korea Institute of Energy Research (KIER)'s $CO_2$ capture process using dry sorbents, and compared the results with those of comparable technologies. Capital and operating costs of the $CO_2$ capture system for 500 MW coal fired power plant were estimated to determine the economic feasibility. LCOE (Levelized Cost of Energy) and $CO_2$ capture cost appeared 32.46$/MWh and 28.15$/ton$CO_2$, respectively. The internal rate of return (IRR), the net present values (NPV), and the payback period (PBP), were calculated by assuming several variables. As the result of calculation, IRR of KIER's $CO_2$ capture system was 15%, NPV was calculated 6,631,000$, and PBP was 5.93 years at $50/t$CO_2$ of CER price. Consequently, this process can compete with other comparative processes using dry sorbents.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.206-212
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• 2000

The effects of two phosphorus sources (fused phosphate and rock phosphate), applied at different rates, on growth, arbuscular-mycorrhizae(AM) formation in roots and nutrient contents of trifoliate orange grown in an uncultivated volcanic ash soil were investigated in a greenhouse. The seedlings were either inoculated with AM fungi or left uninnoculated. Growth of seedlings were best in the treatments of 156-272 mg P/kg with fused phosphate. Although the applied P in the rack phosphate treatments were nearly same or much higher comparing to the fused phosphate treatments, seedling growth were significantly less. Soil available P in the treatment of 272 mg P/kg of fused phosphate was maintained in the range of 3-5 mg/kg during the experiment, and the AM formation was about 60% in average. In the treatments of lower rates of fused phosphate application or of rock phosphate application, soil available P were lower than 3 mg P/kg and AM formations were less than 30%. Significant increases were found in seedling growth and nutrient absorption due to AM fungi inoculation, and the effects were much more significant in the treatments of higher AM formation. In most of citrus groves in Cheju island, soil available P is much higher than 200 mg P/kg, and average AM formation in citrus roots is less than 30%. Results obtained in this study show that the formation of AM can be increased at much lower level of available P than the present levels found in citrus groves.

• Journal of the Korean Geotechnical Society
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• v.28 no.3
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• pp.55-66
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• 2012

To investigate the hysteresis of the suction stress in unsaturated weathered mudstone soils (CL), matric suction and volumetric water content were measured in both drying and wetting processes using Automated Soil-Water Characteristics Curve Apparatus. The drying and wetting processes in unsaturated soils were reproduced in the test; the drying process means to load matric suction to spill pore water from the soils, and the wetting process means to unload matric suction to inject pore water into the soils. Based on the measured result, Soil Water Characteristic Curve(SWCC)s were estimated by van Genuchten model (1980). SWCCs have nonlinear relationship between effective degree of saturation and matric suction. The hysteresis in SWCCs between drying and wetting processes occurred. As a result of estimating Suction Stress Characteristic Curve(SSCC) using Lu and Likos model (2006), the suction stress rapidly increased in the low level of matric suction and then increased slightly. Also, the hysteresis in SSCCs between drying and wetting processes occurred. In order to design geo-structures and check its stability considering unsaturated soil mechanics, therefore, it is more reasonable that the SSCC of drying process should be applied in the condition of rainfall infiltration and the SSCC of wetting process in the condition of evaporation or drainage.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.311-322
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• 2003

Mycorrhizae is well known to increase the uptake of P and other mineral nutrients of plants. But if available P levels in soil is too low or high, mycorrhizae formation is limited. This study was carried out to determine the optimum level of available P for mycorrhizae formation of Poncirus trifoliata (trifoliate orange) seedling in volcanic ash soil. Eight levels of P in the range $0-1050mg\;kg^{-1}$ were applied with double superphosphate, and in each P level mycorrhizal fungi inoculated and uninnoculated treatments were included. The seedlings were grown in a greenhouse for 5 months and mycorrhizae formation, growth, and nutrient uptake were measured. As P application level increased, mycorrhizae formation increased at lower range of P application and the highest formation ratio of 43% was found at $100mg\;kg^{-1}$ P level ($2.6mg\;kg^{-1}$ available P in soil). At further higher levels of P application, mycorrhizae formation was rather suppressed. Seedling growth was increased by the inoculation of mycorrhizal fungi, and maximum growth was found at $100mg\;kg^{-1}$ P level where mycorrhizae formation was highest. The growth and mineral nutrient uptake of Poncirus trifoliata seedling represented a significant positive correlation with mycorrhizae formation at all P treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.272-279
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• 1988

A pot experiment was conducted to define the effect of various soil phosphorus fractions for soybean yield and the relations of between various soil phosphorus fraction and each other in 11 upland soils with different capacities of phosphorus fixation and physico-chemical properties of soils. The effect of phosphorus fertilization was high in soils with high capacities of phosphorus fixation and low available phosphorus, and soybean yield was showed significant relationship with available phosphorus and inorganic soil phosphorus fractions. Fractional recovery of added phosphorus in soils were showed various range of 2.5-91.7%, and mean value of soils was 48.5%. In the relationships among the soybean yield, plant phosphorus content, phosphorus uptake and available phosphorus, inoganic phosphorus at flowering stage, soybean yield were showed significant relationship with available phosphorus content, phosphorus uptake were all showed significant correlation without Fe-P, but Fe-P was showed except Jeju soil. Al-P/Fe-P ratio was increased by phosphorus fertilization in soils at flowering stage, and in the relationships between Al-P/Fe-P ratio and soybean yield, phosphorus uptake, soil and plant phosphorus were showed high significant correlation, but Fe-P was not showed at flowering stage. P sorbed by soils from P 20ppm solution was decreased by phosphorus fertilization, and then decreasing rate was higher in soils with low capacity of phosphorus fixation then high phosphorus fixing soils. Also P sorbed was showed negatively high significant correlation with available phosphorus, plant phosphorus, phosphorus uptake and soil inorganic phosphours except Fe-P, and soybean yield was not showed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.7
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• pp.31-36
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• 2004

In comparison with in-plane lasers, predicting the output power and differential quantum efficiency of Vertical-Cavity Surface-Emitting Lasers(VCSELs) is very difficult due to the distributed Bragg reflector(DBR) layers. Therefore, effective cavity model and transfer matrix method have been adapted in order to calculate the output power and differential quantum efficiency The effective cavity model is inappropriate to calculate output power and differential quantum efficiency while it is practically adequate to calculate the threshold gain and threshold current density The reason is that the effective cavity model can not take account of the absorption in GaAs stack layer right below the metal aperture. In this paper, we have compared the threshold current and differential quantum efficiency calculated by using transfer matrix method with effective cavity model and we have made a study of the validity of the effective cavity model. Finally, we have confirmed the versatility of the transfer matrix method with these studies.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1164-1168
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• 2007

질소 및 인 동시제거 공정 중 대표적인 연속회분식반응조(Sequencing Batch reactor: SBR)는 비교적 간편한 운전방법과 저렴한 건설비, 유입수의 부하변동에 큰 영향을 받지 않는 소규모 하수처리에 적합한 공정으로 알려져 있다. 또한 SBR 공정은 기존 활성슬러지 공법에 비해 적은 부지로 많은 양의 폐수를 처리할 수 있고 유입수 수질 및 유량변동에 따라 다양한 운전주기를 변화할 수 있으며, 유기물 제거뿐만 아니라 반응조의 변형에 의해 영양염류의 제거가 가능한 장점이 있다. 본 연구에서는 bench scale SBR 실험을 통하여 질산염의 탈질속도 및 용해성 인의 흡수와 방출속도를 측정하고, SBR 공정의 무산소조건에서 인흡수 및 탈질을 동시에 수행하는 DPB 존재의 가능성을 파악하고자 하였다. 연구결과 무산소조건에서 S-P의 방출과 흡수가 동시에 진행되었으며, 무산소조건에서 S-P의 방출속도는 $0.08{\sim}0.94\;kgS-P/kgMLSS{\cdot}d$, 흡수속도는 $0.012{\sim}0.1\;kgS-P/kgMLSS{\cdot}d$를 나타내었다. 무산소조에서 S-P의 방출 및 흡수가 진행되는 동안 탈질과정도 함께 진행되었으며, 각각의 F/M비에서 탈질속도를 측정한 결과 F/M비 $0.44\;kgCOD/kgMLSS{\cdot}d$에서는 최대 $0.16\;kgNO_3^-N/kgMLSS{\cdot}d$의 탈질속도를 나타내었다. S-P이 방출되지 않는 경우와 방출되는 경우의 비탈질속도를 비교한 결과 S-P이 방출되지 않는 경우의 비탈질속도가 S-P이 방출되는 경우의 비탈질속도보다 높았다. 이렇게 S-P이 방출되는 경우의 비탈질속도가 더 낮은 이유는 무산소 조건에서 탈질과 S-P의 방출 및 흡수가 동시에 일어나는 경우 S-P의 방출에 관여하는 미생물과 탈질에 관여하는 미생물간의 경쟁반응 때문으로 판단된다.응답법의 적용이 가능함을 보였고, 이는 보다 복잡한 관망에서의 천이류 해석이 가능함을 시사한다.$경상도지리지$\lrcorner$(慶尙道地理志)에는 상주가 8곳으로 1/3의 자기 생산을 담당하고 있었다. $\ulcorner$경상도지리지$\lrcorner$(慶尙道地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당위성 상실로 인한 자기수요 감소를 초래하였을 것으로 사료된다. 셋째, 경기도 광주에서 백자관요가 운영되었으므로 지방인 상주지역에도 더 이상 백자를 조달받을 필요가 없이, 일반 지방관아와 서민들의 일상용기 생산으로 전락하여 소규모화 되었을 것이라고 사료된다.장 운동기능을 향상시키는 유효성분의 보강 등이 필요하다는 점도 알 수 있었다.더불어 산화물질 해독에 관여하는 다른 유전자

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.354-363
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• 2007

In order to investigate the optimum rate and interval of silicate fertilizer application for rice cultivation, Chucheong byeo variety, one of commonly cultivated rice cultivar in Korea was planted on two different wetland rice soils located on Hwaseong-si from 2002 to 2005; Jisan series(a member of the fine loamy, mixed, mesic family of Fluvaquentic Endoaquepts), known as "Productive Paddy Soil", without any conspicuous limiting factor, and Seokcheon series (a member of the coarse loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquetps), known as "Sandy Paddy Soil", sandiness being major limiting factor. There were three rate treatments of silicate fertilizer application; the amount of silicate fertilizers needed to adjust the available soil silicate contents to 130, 200, and $270mg\;kg^{-1}$ was applied, in the first year only. There was an additional plot; applying the amount of silicate fertilizer needed to adjust soil available silicate to 130 ppm every year, which would serve as the base for the evaluation of residual effects of silicate fertilizers in the plots where different rates of silicate fertilizer were applied. From the yield data in first year, it was found that optimum available silica in the soil are $154mg\;kg^{-1$ and $160mg\;kg^{-1}$, in Jisan and Seogcheon soils, respectably. The duration of residual effects of silicate fertilizer was different depending upon the amount of applied silicate fertilizers and the soils. The higher the application rate, the residual effect lasted longer, and the residual effect was lasted longer in Jisan(clay loam) soil than in Seogcheon(sandy loam) soil. During four years, sum of the rate of contribution to increase available soil silica of applied silicate fertilizer in different soils ranged 18.6% and 24.1% in Jisan soil and Seogcheon soil, respectively. This may suggest that much portion of applied silicate would be either lost from the soil or remain in the soil as insoluble form. This deserves further study.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.3
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• pp.85-91
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• 1981

In order to evaluate effectiveness of zinc source on uptake of zinc by rice plant, a pot experiment carried out using ZnEDTA and $ZnSO_4$ in a glasshouse. The results obtained were summarized as follows: The effectiveness of zinc source on uptake of zinc by rice plants was different with different soil. Namely ZnEDTA was more efficient than $ZnSO_4$ in increasing yield of zinc and concentration of zinc in the plant grown on Jecheon calcareous soil. In case of Keumgok acid soil, however, no superiority of ZnEDTA treatment was found. The plant growing status of ZnEDTA treated calcareous soil was also shown that larger number of tillers per hill, bigger height of the plant and good yield of dry matter production than those of the plant grown on $ZnSO_4$ treatment. Regardless of the zinc source, smaller number of tillers per hill, shorter height of the plant, and the lowest yield of dry matter were shown in the treatment of zinc and straw mixed with both soils. It seemed that more applied zinc was to be fixed by the straw application resulting in poor zinc yield. The extent of the zinc fixation showed markedly in Jecheon calcareous soil.