• Journal of Korea Technology Innovation Society
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• v.21 no.4
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• pp.1345-1365
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• 2018

Following principal-agent relationship between government and funding agency effects on efficiency and management of project, this paper suppose that project management cost rate variable on outsourcing and administration of institution, applies multiple regression analysis and logit analysis by using factors that procurement status of institutional operating expenses and each subordinates scale (Budget, subject number) and method (Top-down/Bottom-up), not a total amount, for examining factors following project efficiency analysis and way of commission. The major variables which effect on efficiency of institution are management cost scale (0.36), institutional operating expenses ratio (-0.47), way of outsourcing, the factors that affect way of outsourcing are portion of project management cost (-38.5) and institutional operating expenses rate (-11.7). This means both legal and financial stability are necessary and it is avoidable moral hazard and adverse selection on principal-agent problem.

• Journal of Conservation Science
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• v.37 no.4
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• pp.370-379
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• 2021

In the past, PVAc [poly(vinyl acetate)] was used as a fixative for the conservation of the murals in the murals of the Payathonzu temple located in Bagan, Myanmar. In this study, attention was paid to gel cleaning as a method for stably removing such PVAc fixatives. Based on the recent research trend related to the cleaning of murals in Bagan ruins, 3 types of gelling agents (Nevek^®, Laponite^®RD, Carbopol^®980) and 2 types of organic solvents (Acetone, Dimethyl carbonate) were selected. Six types of gel cleaners were prepared by mixing gelling agents and organic solvents, and the properties and fixative removability of these cleaners were compared. As a result of confirming the properties of the prepared gel cleaners, the pH of the cleaners was all in the weak acidic to weakly alkaline range, which was a stable condition for mural application. Also, there was no difference in the viscosity of the cleaners depending on the type of solvent, but there was a difference depending on the type of gelling agent used. Regarding the weight loss ratio of PVAc, which is an indicator of removability, the exposure conditions of the gel cleaners, the boiling point of the solvent used, and the viscosity of the gelling agent acted as factors affecting. As a result of comparing the removability of gel cleaners, it was confirmed that the solvent's fixative solubility, the volatility of the solvent itself, and the solvent release control properties of the gelling agent had a great effect on the removability of the gel cleaners. In Part 2, the stability and the running applicability of the gel cleaners will be investigated by making mockup samples reflecting the properties of the materials and techniques used to produce the mural paintings in the Payathonzu Temple.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.3
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• pp.237-246
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• 2021

With climate change, debris flow has been increasing due to the collapse and erosion of shallow slopes caused by extreme rainfall. It is preferred to an economical and eco-friendly method rather than reinforcement of soil slopes with the earth anchor or nailing method. In this study, a soil improvement agent was developed by utilizing insitu soil, leaf mold, and used harbal medicine to help sufficient vegetation. In addition, to prevent surface erosion, shear strength of the soil was increased by using micro cement and hemihydrate gypsum as additives. The optimum mix ratio of the mixture is determined by increasing the shear strength by checking the erosion progress of the ground surface layer due to rainfall through an laboratory test. The safety factor of soil slope has been improved on the slope surface reinforced by the improvement agent, and the strength of erosion has been increased, making it efficient to cope with heavy rain during wet season.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.475-481
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• 2007

This study was carried out to determine the quality characteristics of Jeju mandarin orange jelly with various gelling agent such as agar, ${\kappa}-carrageenan$ and gellan gum for the aged. The concentration of agar was 0.4-0.6% and that of ${\kappa}-carrageenan$ and gellan gum was 0.2-0.4%. The color value, gelling temperature, melting temperature, break down rate, textural properties and sensory acceptance test of Jeju mandarin orange jelly with various gelling agent were measured. Average age of the subjects for acceptance test was 78.23. Redness and yellowness of Jeju mandarin orange jelly with agar was lower than that with ${\kappa}-carrageenan$. The gelling and melting temperature of Jeju mandarin orange jelly with agar was lowest among the jellies. Break down rate of Jeju mandarin orange jelly with agar was highest among the jellies. Above results showed that the stability of Jeju mandarin orange jelly with agar was inferior than that with ${\kappa}-carrageenan$ and gellan gum. Hardness, adhesiveness and springiness of Jeju mandarin orange jelly with agar was lowest among the jellies and sensory acceptance of Jeju mandarin orange jelly with gellan gum was highest among them. Thus, gellan gum was appropriate gelling agent for the Jeju mandarin orange jelly with regard to the acceptability and the depression of sour taste in Jeju mandarin orange jelly could improve the acceptability for the aged.

• Analytical Science and Technology
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• v.5 no.3
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• pp.239-247
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• 1992

The complexations and selectivities of the 10 species of mono- and dimethylsubstituted anilinium ions with 18-crown-6 in methanol are examined at dropping mercury electrode. The stability constants of these complexes varies drastically due to the steric hindrance by the positions and numbers of methyl groups. And the analyses of the isomeric mixtures of methylanilinium, which are impossible to detect due to the overlapped peaks in normal conditions, were also accomplished by the additions of 18-crown-6 as the supporting complexing agent using the selective complexations by the steric hindrance effects. As results in case of the difference of stability, ${\Delta}log\;K$ were about 0.7~1.3, it was possible to confirm the existence of two species qualitatively. Otherwise when ${\Delta}log\;K$ were large than 1.6, the quantitative determinations of each species could be accomplished sucessfully. From these results it is deduced that the selective recongnition of the positions and numbers of methyl groups as the steric hindrance in anililniums by 18-crown-6 cause the large variation of the magnitudes of negative shift of reduction waves for guest ions in mixtures.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.170-175
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• 2004

In this paper we studied about Bacillus sp. TBM40-3 producing biosurfactants. The strains were isolated from Taeback Mountain soil and identified as Bacillus sp. by l6S rDNA nucleotides sequence analysis. The TBM40-3 was gram-positive and rod-shaped as observed by field emission scanning microscopy. After the cultivation TBM40-3 in LB broth for 90 h and the surface tension of supernatant was decreased to 29 mN/m. Emulsification activity and stability of crude biosurfactant was measured by using water-immiscible hydrocarbons and oil as substrate. Maximum emulsification activity and stability was obtained from soybean oil. Also, we confirmed that the TBM40-3 producing biosurfactant had an effect on crude oil while showing a superior effect as compared to chemically synthesized surfactants (SDS, Span85, Tween40, Triton X-100). As a result, the Bacillus sp. TBM40-3 producing biosurfactant had potent properties as an emulsifying agent and an emulsion stabilizing agent.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.79-87
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• 2008

Many researchers have studied on rooftop greening that can be installed in abandoned spaces on a building roof. The most important issue in rooftop greening is the soil weight problem. The light greening materials are needed to solve this problem. Therefore, many alternative materials against the soil were investigated for rooftop greening. In this study, the waste wood chips and the waste paper slurry were evaluated as the lightweight vegetation foundation for rooftop greening. It also has a meaning for recycling of waste materials. The mixture ratio of waste wood chips to waste paper slurry for the board (the foundation of greening) was 60 to 40. The wet strength resin and the sizing agent were additionally added with different amount. After the forming of the board, physical and chemical properties were tested with the variation of wet strength resin and sizing agent. As the result of the test, the board with 15% of wet strength resin in the wet condition showed the highest strength. Futhermore, the moisture evaporation loss from the board surface with sizing agent was much lower than that from the board without sizing agent. Therefore, it was clear that the sizing agent was effective for water retention. The change of thickness in the wet condition was less than 1 mm, and it showed that the board is the predominant material on the dimensional stability. The average pH value of the board was ranged from 7.6 to 8.25.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.183-188
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• 1998

Changes of chemical and physical properties of the butchery waste compost were assessed when the wastepaper was used as a bulking agent (BP). Temperature of compost, with frequent turnover, was increased up to $83^{\circ}C$ even during the winter. Canon exchange capacity of the compost was increased with composting time, but pH, water content, total carbon, total nitrogen, C/N ratio and salt concentration were decreased to the extents showing a convergency. Heavy metal contents of BP-192 were lower than the standard criteria. Germination rate of cucumber seed, when BP-34 and BP-96 composts were applied more than 15 g, was under 40%, but those of BP-143 and BP-192 were 100%, irrespective of the amounts of compost used. The C/N ratio of the matured compost was 8.6. Results indicated that wastepaper might be employed as a bulking agent for butchery wastes composting.

• Composites Research
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• v.16 no.2
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• pp.54-61
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• 2003

In this study, manufacturing process for microcapsules with the self-healing agent was introduced and the characteristics of microcapsules manufactured by varying with various manufacturing process variables were evaluated through a particle size analyzer, an optical microscope, and a TGA. Urea-formaldehyde resin was used for the thin wall of microcapsules and DCPD (dicyclopentadiene) was used for the self-healing agent. The various manufacturing process variables, such as (1) 24hr, 40hr, 48hr, 60hr of the solution time of the EMA copolymer, (2) pH3.5, pH4.0, pH4.5 of the hydrogen ion concentration of the emulsified solution, (3) 400rpm, 500rpm, 600rpm, 1000rpm of the agitation speed of the emulsified solution, (4) $50^{\circ}$, $55^{\circ}$, $60^{\circ}$ of the reaction temperature of the emulsified solution, were considered. According to the results, the particle size distribution of microcapsules was affected on the agitation speed, and the thermal stability of microcapsules was influenced by the solution time of the EMA copolymer, the hydrogen ion concentration, and the reaction temperature of the emulsified solution. Therefore, suitable manufacturing process variables should be applied to obtain thermally stable microcapsules capable of containing the healing agent capable until the thin wall of microcapsules were to be burned.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.230-236
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• 2019

Recently, issues related to the quality of concrete have continuously resulted in surface quality problems, such as the exfoliation of concrete surfaces due to the cost reduction of cement and poor quality fine aggregate, scaling of surfaces caused by laitance, and plastic shrinkage cracks. Prompted by social issues, the application of a photo catalyst to road structures is being attempted to solve the environmental problems caused by fine dust and automobile exhaust. In this study, chemical admixtures were developed to improve the surface quality of concrete and to apply and distribute titanium dioxide in nanoscale sizes to provide basic data for the development of a photocatalyst-curing agent. As a result of the experiment, silicon and silane were reviewed as a raw material as a curing agent to develop a high performance curing agent with better film performance than conventional curing agents because they could form a film quickly on a fresh concrete surface. The distributed stability of the ultrasonic disperser showed the best performance through an outdoor test for four weeks to review the dispersion measures for the application of nanomaterials.