• Korean Chemical Engineering Research
• /
• v.47 no.5
• /
• pp.630-638
• /
• 2009

A computational fluid dynamics(CFD) model is developed and validated with on-site experiments for a urea-based SNCR(selective non-catalytic reduction) process to reduce the nitrogen oxides($NO_x$) in a municipal incinerator. The three-dimensional turbulent reacting flow CFD model having a seven global reaction mechanism under the condition of low CO concentration and 12% excess air and droplet evaporation is used for fluid dynamics simulation of the SNCR process installed in the incinerator. In this SNCR process, urea solution and atomizing air were injected into the secondary combustor, using one front nozzle and two side nozzles. The exit temperature($980^{\circ}C$) of simulation has the same value as in situ experiment one. The $NO_x$ reduction efficiencies of 57% and 59% are obtained from the experiment and CFD simulation, respectively at NSR=1.8(normalized stoichiometric ratio) for the equal flow rate ratio from the three nozzles. It is observed in the CFD simulations with varying the flowrate ratio of the three nozzles that the injection of a two times larger front nozzle flowrate than the side nozzle flowrate produces 8% higher $NO_x$ reduction efficiency than the injection of the equal ratio flowrate in each nozzle.

• The Korean Journal of Rheology
• /
• v.11 no.2
• /
• pp.82-90
• /
• 1999

Electrorheological(ER) fluid is a material that shows the dramatic change of rheological properties under an electric field and responds reversibly in a few milliseconds. ER fluid's response to an electric field along with its fast switching capability allows ER devices to be precisely controlled. The real application with ER fluid, however, has many limitations to be overcome; temperature fluctuation, moisture, dust, aggregation, precipitation, and low yield stress, for example. The magnitude and the characteristics of yield stress of ER fluid plays an important role in practical applications. In this research, a dynamic simulation on the squeezing flow of the ER fluid was carried out. Numerical simulation on isolated chains was performed to find out the effect of hydrodynamic and electrostatic force depending on the chain location, the squeezing rate, and the chain structure. Suspension model that is composed of a large number of particles was also investigated. The increase of normal stresses as well as the existence of a yield stress at an earlier stage could be observed, and the effective control of the normal stresses could be achieved at an optimal condition of the hydrodynamic force and the electrostatic force.

• Current Research on Agriculture and Life Sciences
• /
• v.1
• /
• pp.141-150
• /
• 1983

This report decribes the changes of internal browning and PPO in apples, when the method of storage was changed in the condition of low temperature. Internal browning was found more Fuji harvested in November than Fuji in October. The degree of internal browning was the highest during the storage of 0.09mm 2% and 0.06mm 2%, 0.06mm 20% was followed. In the subatmospheric storage with complete remove of $CO_2$ internal browning was not observed. During the storage of P.E. film bag, Fuji havested in November was higher than in October, and Fuji on 0.09mm 2% was higher than in 0.06mm, and Fuji during the storage of P.E. film bag was increased in PPO activity and PPO specific activity. During the subatmospheric storage with complete remove of $CO_2$, PPO activity of Fuji was little changed, but it's PPO specific activity was continuously decreased. PPO activity of Ralls was more higher than PPO activity of Fuji. PPO activity and PPO specific activity during the early stage of storage and the end stage of storage were little changed. Internal browning of Fuji was more effected $CO_2$ injury than chilling injury. There is no relation between internal browning and degree of PPO activity was effected by $CO_2$ and slightly related with internal browning.

• Korean journal of applied entomology
• /
• v.48 no.3
• /
• pp.369-375
• /
• 2009

A commercial egg parasitoid, Trichogramma sp. Nabis101, was released into agricultural cultivating areas in Korea due to its wide host spectrum against insect pests. Moreover, an application technique has been recently developed to enhance its control efficacy by mixture treatment with a microbial control agent. Despite its expansion of commercial availability, any genetic identification on this commercial strain was not determined. Also, to meet inconsistent demands from consumers, the live parasitoids need to be stored without significant loss of their survival and parasitic activity. This study determined nucleotide sequence of internal transcribed spacer (ITS) of the wasp species. The identified ITS sequences indicate that this wasp species is most similar to T brasiliensis. Optimal storage condition of this wasp required young parasitized stage at $10^{\circ}C$. Under these conditions, survival, sex ratio, longevity, and parasitic behavior were not much impaired for 5 weeks.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.3
• /
• pp.343-348
• /
• 2015

Soybean is one of the important food crop around the world. Especially in East Asia, it is the main ingredient for traditional food like soy sauce and soy paste. The double cropping system including soybean following onion, Chinese cabbage, and potato is widely adopted in Southern region of Korea. In this system, sowing date of second crop (soybean) can be delayed depending on first crops' growth period and weather condition. When planting date is delayed it is known that soybean yield is declined because of shorter vegetative growth period and earlier flowering induced by warm temperature and changes in photoperiod. The objective of this study was to determine soybean growth and yield responses as plant populations at late planting date. Field experiment was conducted at Department of Functional Crop, National Institute of Crop Science, RDA located in Miryang, Gyeongsangnam-Do for two years ('13-'14) in upland field with mid-late maturity cultivar Daewon. A split-plot block design was used with three replications. Main plots were three sowing dates from June 20 to July 20 with 15 days intervals, and subplots were 4 levels of planting densities. Data of maturity (R8) was recorded, yield components and yield were examined after harvesting. Experimental data were analyzed by using PROC GLM, and DMRT were used for mean comparison. Optimum planting population for maximizing soybean yield in late planting which compared with standard population. In mid-June planting, higher planting density causes increased plant height and decreased diameter which lead to higher risk of lodging, however, reduced growth period due to late planting alleviated this problem. Therefore higher seeding rates can provide protection against low seedling emergence caused by late planting in this region.

• Journal of Plant Biotechnology
• /
• v.35 no.4
• /
• pp.281-290
• /
• 2008

In plant, Receptor-like kinases (RLKs) are protein family, though its function is not yet understood, consisted of a predicted signal sequence, single transmembrane region, and cytoplasmic kinase domain. RLKs are involved in hormonal response pathways, cell differentiation, plant growth and development, self-incompatibility, and symbiont and pathogen recognition. In this study, expression levels of RLG1, RLG5, RLG6, RLG#6, RLG8, RLG10, RLG17, RLG18 and RLG20 were analyzed by Real-time PCR, when rice (Oryzae sativa) was treated abiotic stress. The expression levels of all RLGs were compared each other by analyzed value of threshold cycles ($C_T$). Consequently, RLGs were suppressed by NaCl as salinity stress, and expression of each RLK genes were showed difference treated salicylic acid and wound, respectively. However, All RLGs were induced under low temperature condition. Therefore, our results indicate protection-function of RLK genes to be an early response of rice against cold weather.

• Journal of the Korean earth science society
• /
• v.25 no.6
• /
• pp.443-473
• /
• 2004

In northern Gohung granitic gneiss, porphyroblastic gneiss and migmatitic gneiss are widely distributed. Gneisses were plotted in granodiorite domain on an lUGS silica-alkali diagram. The amounts of trace elements (Li, Zn, Sc, Sr, Ni, V Y etc.) vs. $SiO_2$, somewhat decreased. Plagioclase showed a wide compositional range ($An_{32-48}$). $X_{alm}$ and $X_{sps}$ were higher in garnet rim and $X_{pyp}$ in garnet core. The rocks in the study area were formed from S and I-type magmas which generated from syn-collision and the late to post-orogenic tectonic environment. Metamorphic P-T conditions u·ere low to medium pressure, high temperature (803-913$^{\circ}C$, 6.1-7.3 kb) and overprinted by retrograde metamorphism (570-726$^{\circ}C$, 2.2-5.1 kb) and chloritization.

• Transactions of the Korean hydrogen and new energy society
• /
• v.25 no.3
• /
• pp.219-226
• /
• 2014

In HI decomposition, $Pt/Al_2O_3$ has been studied by several researchers. However, after HI decomposition, it could be seen that metal dispersion of $Pt/Al_2O_3$ was greatly decreased. This reason was expected of platinum loss and sintering, which platinum was aggregated. Also, this decrease of metal dispersion caused catalytic deactivation. This study was conducted to find the condition to minimize platinum sintering and loss. In particular, heat treatment atmosphere and temperature were examined to improve the activity of HI decomposition reaction. First of all, although $Pt/Al_2O_3$ treated in hydrogen atmosphere had low platinum dispersion between 13 and 18%, it was shown to suitable platinum form that played an important role in improving HI decomposition reaction. Oxygen in the air atmosphere made $Pt/Al_2O_3$ have high platinum dispersion even 61.52% at $500^{\circ}C$. Therefore, in order to get high platinum dispersion and suitable platinum form in HI decomposition reaction, air heat treatment at $500^{\circ}C$ was needed to add before hydrogen heat treatment. In case of 5A3H, it had 51.13% platinum dispersion and improved HI decomposition reaction activity. Also, after HI decomposition reaction it had considerable platinum dispersion of 23.89%.

• KSBB Journal
• /
• v.23 no.5
• /
• pp.403-407
• /
• 2008

Recently, Candida antarctica lipase B (CalB) draws attention from industries for various applications for food, detergent, fine chemical, and biodiesel, because of its characteristics as an efficient biocatalyst. Since many industrial processes carry out in organic solvent and at high temperature, CalB, which is stable under harsh condition, is in demand from many industries. In order to reform CalB promptly, the expression system which has advantages of ease to use and low cost for gene libraries screening was developed using E. coli. The E. coli strains, Rosettagami with competence for enhanced disulfide bond formation, Novablue, and $DH5{\alpha}$, were exploited in this study. To obtain the soluble CalB, the pCold I vector expressing the cloned gene at $15^{\circ}C$ and the chaperone plasmids containing groES/groEL, groES/groEL/tig, tig, dnaK/dnaJ/grpE, and dnaK/dnaJ/grpE/groES/groEL were used for coexpression of CalB and chaperones. The colonies expressing functional lipase were selected by employing the halo plate containing 1% tributyrin, and the CalB expression was confirmed by SDS-PAGE. E. coli Rosettagami and $DH5{\alpha}$ harbouring groES/groEL chaperones were able to express soluble CalB effectively. From a facilitative point of view, E. coli $DH5{\alpha}$ is more suitable for further mutation study.

• Composites Research
• /
• v.24 no.4
• /
• pp.23-28
• /
• 2011

Recently CFRP laminate joints process by bolts and nets are developed rapidly in aircraft industries. However, there are serious drawback during jointing process. Many hole processes are needed for the manufacturing and structural applications using composite materials. Generally, very durable polycrystalline crystalline diamond (PCD) drill has been used for the CFRP hole process. However, due to the expensive price and slow process speed, chemical vapor deposition (CVD) diamond drill has been used increasingly which are relatively-low durability but easily-adjustable process speed via drill shape change and price is much lower. In this study, the comparison of hole process between PCD and CVD diamond coated drills was done. First of all, CFRP hole processbility was evaluated using the equations of hole processing conditions (feed amount per blade, feed speed). The comparison on thermal damage occurring from the CFRP specimen was also studied during drilling process. Empirical equation was made from the temperature photo profile being taken during hole process by infrared thermal camera. In addition, hole processability was compared by checking hole inside condition upon chip exhausting state for two drills. Generally, although the PCD can exhibit better hole processability, hole processing speed of CVD diamond drill exhibited faster than PCD case.