• Horticultural Science & Technology
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• v.32 no.2
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• pp.193-201
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• 2014

We investigated the effect of preharvest spray of aminoethoxyvinylglycine (AVG) on the fruit quality and incidence of physiological disorders during shelf-life of 'Hanareum' and 'Wonhwang' pear (Pyrus pyrifolia Nakai). AVG applications (0, 75, 150 and $300mg{\cdot}L^{-1}$) made 30 days before anticipated harvest of respective cultivar. AVG did not influence the fruit development and quality parameters including starch content, soluble solids and acidity at harvest time in two pear cultivars although the flesh firmness of the fruits treated with $300mg{\cdot}L^{-1}$ AVG were higher than that of control in 'Hanareum' pear. Among the three AVG concentrations, only $300mg{\cdot}L^{-1}$ AVG showed effectiveness on maintaining flesh firmness in 'Hanareum' pear during shelf-life. Meanwhile, competitive high flesh firmness was attained in 'Wonhwang' pear treated with $150mg{\cdot}L^{-1}$ AVG (27.7 N) and $300mg{\cdot}L^{-1}$ AVG (28.2 N) when compared with untreated control (17.8 N) during 21 days of shelf-life at $25^{\circ}C$. AVG did not cause any significant difference at skin color development relative to control in two pear cultivars. AVG decreased ethylene production and respiration rate at $300mg{\cdot}L^{-1}$ level in two pear cultivars during the entire shelf-life. During shelf-life, low incidence of physiological disorders including internal and core browning and mealiness were attained in the fruits treated at $300mg{\cdot}L^{-1}$ AVG in two cultivars when we compared with the untreated control.

• Journal of Conservation Science
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• v.16 s.16
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• pp.77-88
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• 2004

This study evaluates the occurrences, phyfical weathering and biological deterioration on rock properties during the dissection process an object of stone pagoda in the Mireuksaji temple site. For restoration and conservation, all kinds of rock properties are carried out detailed scientific investigation and diagnosis. Constituting rocks of the pagoda composed mainly of equi-granular medium grained biotite that rock properties presumed to be use about 3,000 materials. Main external properties of the pagoda are total 446 materials, and the rock properties under the concentration load on the each floors occurred with overlapping fracture, weathering and deteriorations. The 84 materials show highly degraded about $18.8\%$ among the external properties. Representative physicochemical deteriorations are fracture, loss, break, exfoliation, degradation, grain shaped dissolution, relief surface, discoloration and hydroxide precipitates, in this study, the deterioration state of each properties give a precisely description and analysis. Coverage of lichen and algae on the rock surface represented about $85\%$. As the some properties, biological contaminants withered up when spray rock surface with diluted cleaning chemicals. Results of the study are utilized an application for restoration system and detailed investigation during the dissection process of stone cultural properties.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.283-290
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• 2008

Baculoviruses have been used to control some serious lepidopteran pests. However, their narrow target insect spectrum and slow efficacy are main limitations to be used in various applications. This study introduces a technique to overcome these limitations by inhibiting insect immune defence to enhance the viral pathogenicity. Polydnaviruses are an insect DNA virus group and symbiotic to some ichneumonid and braconid endoparasitoids. Cotesia plutellae bracovirus (CpBV) is a braconid polydnavirus and encodes several immunosuppressive genes. We selected seven CpBV genes and recombined them to wild type Autographa California multiple nucleopolyhedrovirus (AcNPV). A bioassay of these seven recombinants indicated that most recombinants had similar or superior efficacy to wild type AcNPV against beet armyworm, Spodoptera exigua, and diamondback moth, Plutella xylostella. Recombinant AcNPV with CpBV-ELP was the most potent in terms of lethal time by shortening more than 2 days compared to wild type AcNPV. This recombinant was further proved in its dose-dependent pathogenicity and its efficacy by spray application on S. exigua infesting cabbage cultivated in pots. We discussed the efficacy of CpBV-ELP recombinant AcNPV in terms of suppressing antiviral activity of target insects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.248-255
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• 2020

The effects of the coating thickness on the thermal durability and thermal stability of thermal barrier coatings (TBCs) with a gradient coating thickness were investigated using a flame thermal fatigue (FTF) test and thermal shock (TS) test. The bond and topcoats were deposited on the Ni-based super-alloy (GTD-111) using an air plasma spray (APS) method with Ni-Cr based MCrAlY feedstock powder and yttria-stabilized zirconia (YSZ), respectively. After the FTF test at 1100 ℃ for 1429 cycles, the bond coat was oxidized partially and the thermally grown oxide (TGO) layer was observed at the interface between the topcoat and bond coat. On the other hand, the interface microstructure of each part in the TBC specimen showed a good condition without cracking or delamination. As a result of the TS test at 1100 ℃, the TBC with gradient coating thickness was initially delaminated at a thin part of the coating layer after 37 cycles, and the TBC was delaminated by more than 50% after 98 cycles. The TBCs of the thin part showed more oxidation of the bond coat with the delamination of topcoat than the thick part. The thick part of the TBC thickness showed good thermal stability and oxidation resistance of the bond coat due to the increased thermal barrier effect.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.221-227
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• 1996

Four strains of Beauveria bassiana F101, F587, F9 and FJ8, were received from Forestry Research Institute,Seoul. The strain, B. bassiana F101, was the most active in the enzymatic activity and spore production. Whenspores of B. bassiana FlOl were sprayed on the female larva of the black tipped sawfly with various concentrationsof 6 xl 0'~-10s~p ores/ml, insects started to die from 5-7 days, and were covered with mycelia andspores in 24-28 days at 25"C, while the insect did not show visible symptoms even after 50 days at 4'C. Theinsect injected with 5 pl of spore solution (3X l0'~-10s~p oreslml) died within 30-98 and 38-218 hours at25$^{\circ}$C and 4"C, respectively. About 3 days (60 hours) after the injection with a concentration of 3 x lo9 spores1ml, at the point of the insect's death, lots of proteins started to disappear '||'&'||' the hemolymph, fat body and carcaseat 25'C. Esterase activity in the tissues was gone suddenly after that time. Six days after the spray, manyprotein and esterase bands were lost in the hemolymph, but not those in the fat body and carcase. When thefungi growing in the host were exposed in the air, they put energy for spore production, while numerous longand thin mycelia branched out from the host body in the soil.e host body in the soil.

• Fire Science and Engineering
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• v.26 no.2
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• pp.75-83
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• 2012

An experimental study was conducted to investigate the effects of change in heat release rate on unsteady fire characteristics of under-ventilated fire in a semi-closed compartment. A standard doorway width of the full-scale ISO 9705 room was modified to 0.1 m and the flow rate of heptane fuel was increased linearly with time using a spray nozzle located at the center of enclosure. Temperature, heat flux, species concentrations and heat release rate were continuously measured and then global equivalence ratio (GER) concept was adopted to represent the unsteady thermal and chemical characteristics inside the compartment. It was observed that there was a significant difference in unsteady behavior between global and local combustion efficiency, and the GERs predicted by ideal and measured heat release rate were also shown different results in time. The unsteady behaviors of temperature, heat flux and species concentrations were represented well using the GER concept. It was important to note that CO concentration was gradually decreased with the increase in GER after reaching its maximum value in the range of 2.0~3.0 of global equivalence ratio. In addition, the experimental data on unsteady thermal and chemical behaviors obtained in a semi-closed compartment will be usefully used to validate a realistic fire simulation.

• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.111-118
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• 2009

A hybrid SNCR/SCR plant was designed and manufactured, and experimented on the SNCR process in the first step to investigate the optimum operation conditions of SNCR, with the equivalence ratio of the reducing agent(NSR, 0.5~5.0), reaction temperature($850{\sim}1,100^{\circ}C$), nozzle type(wall nozzle, pipe nozzle), and nozzle position as variables. In the case of wall nozzles, the NOx reduction efficiency rapidly increased to 87% at 2.5 NSR and slowed down after this. Compared to the upward spray from the pipe nozzle, wall nozzles have narrower range of applicable reaction temperature. In the case of pipe nozzles, it rapidly increased to 77% at 1.5 NSR. But the pipe nozzle downward had no NOx reduction efficiency; on the contrary, NOx increased. When the reducing agent was sprayed upward from a pipe nozzle, the NOx reduction efficiency was 50~75% in the range of 0.5~1.5 NSR, and the NOx reduction efficiency was constant without fluctuations even in the change of reaction temperature from 890 to $1,000^{\circ}C$. When 5% urea solution was sprayed upward from the pipe nozzle, 200 ppm NOx decreased to approximately 60 ppm at 1.2 NSR, and the non-reacted $NH_3$ was 50~100 ppm. In this condition, we expect over 90% NOx reduction efficiency without additional supply of $NH_3$ to SCR at the back of SNCR.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.4
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• pp.97-105
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• 2012

This study examined for possibility of the food wastewater incineration treatment method as one of overland treatment method by incineration through liquefied spray of food wastewater when incinerating domestic wastes under operation and for the relationship, etc of air discharge material discharged in incineration, and the results of study are as follow: The food wastewater as one of overland treatment method was analysed 94-96% of moisture contents. Temperature of incinerator outduct during mixed incineration of food wastewater with MSW was average $897^{\circ}C$ and incineration of only MSW was $925^{\circ}C$. Temperature of the mixed incineration of food wastewater was dropped about $28^{\circ}C$ by incineration of only MSW. Concentration of nitrogen oxides(NOx) among air discharge gases was studied by 50ppm, 46ppm when inputting $200{\ell}/hr$, $300{\ell}/hr$ into the incinerator as the quantity of food wastewater. In the mixed incineration of food wastewater, generation speed of scales in the inside of a tubular exhaust gas boiler became rapid and the scale generation quantity became large but the exhaust gas boiler normally operated since scales were removed in cleaning of the tube with a compressive air cleaning facility and there was no opening clogging phenomena in a filter cloth of the filtering dust collector. The overland treatment method, not ocean dumping of food wastewater can be proposed as a technology since mixed incineration of food wastewater with MSW in the existing domestic waste incineration plant is possible, and operation costs of the incineration facility were reduced since use of chemicals such as ammonia and urinary hydrogen ion excretion, etc used in incineration facilities for removing nitrogen oxides(NOx).

• Tunnel and Underground Space
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• v.28 no.1
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• pp.97-110
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• 2018

The application of sprayed waterproofing membrane with high adhesion and ductility is considered to be promising as a measure for repair and reinforcement of a tunnel structure. Therefore, a powder-type and one-component membrane prototype with high tensile and bond strengths was made in this study. Then, its reinforcement effect on a shield segment was evaluated by carrying out a series of full-scale loading tests of segment specimens on which the membrane was sprayed. From the tests, it was confirmed that the initial cracking loads increased by approximately 34% due to cracking retardation by membrane coating. Even though the increase of failure loads were not so high as cracking loads, the strain-softening behaviors were observed from specimens coated by the membrane. Therefore, it is expected that the membrane coated on the inner surface of a lining might be effective in preventing its brittle failure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4656-4663
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• 2010

In this study, the 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics, flow distribution, air mean ages, and residence time for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. In addition, it showed the possibility that the velocity field and distribution characteristics of the residence time could be improved through a modification to inlet structure of the spray dryer reactor. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, the installation area, the operation fee, and management more convenient.