• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.3
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• pp.38-45
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• 1998

Soil and water contamination caused by the abundant use of agricultural chemicals including herbicides and fertilizers draws public concerns since these chemicals may pollute the agricultural lands as well as the food products grown on these lands. As a method to reduce the use of agricultural chemicals mulching with thin plastic film has been commonly practised for many years. Although use of the plastic film for mulching is very effective in preventing the growth of weed, it is almost impossible to remove all of the plastic film from the agricultural land and the remaining film eventually contaminates the soils. Therefore, it is very imperative to develop a mulching material that decomposes completely to prevent soil pollution problems and to enhance the competitive edge of domestic agriculture. Mulch papers are believed to have many positive characteristics in preventing problems caused by the plastic mulch film since it decomposes completely after use. However, the basis weight of mulch papers needs to be reduced to improve its handling properties and to reduce the raw material costs of pulps. In this paper the possibilities of using domestic old corrugated containers in producing mulch papers were examined. Also use of unbleached softwood kraft pulps and dry strength additives were exploited along with two-layered sheet forming technology in decreasing the basis weight of the mulch paper. Results showed that reduction of 20g/$m^2$ of basis weight of mulch paper was possible by the appropriate raw material selection and application of strength resin. To use the mulch papers in paddy fields, however, further research to improve its durability should be pursued.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.5
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• pp.141-152
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• 2011

Cuttings based on water media are relatively low-cost and easy to manage compared to those based on soil media. Nevertheless, species that root out in water media are very few. Water-medium rooted cuttings are not widely used. In water media, the survival rate of cuttings is high, but in many cases, they only form callus while not rooting. If cuttings with callus formed in a water medium were to root and survive after being transplanted in soil, water-medium cuttings could be used as an important means of propagating landscape tree species. In this study, cuttings of Ternstroemia japonica having various reactions to water media were soaked in different types of water media. Their callus formation and rooting conditions were analyzed. The water-medium cutting swere then transplanted in soil, and conditions for their survival were examined. The study concluded: 1. Cuttings that only formed callus in water media were able to root and survive after being transplanted. 2. Cuttings with satisfactory callus formation showed more satisfactory survival conditions than those with unsatisfactory callus formation. 3. Cuttings rooted in water media showed a high survival rate of 96.6% after being transplanted. 4. Water-medium cutting of Ternstroemia japonica proved to be more effective in Late July or August than in late June. 5. Cuttings pre-treated in 50ppm-IBA for 24 hours showed better survival conditions than those that were not pre-treated inIBA. 6. Cuttings pre-treated in 50ppm-IBA for 24 hours and soaked in water media with 0.02% atonic, 0.02% polyoxin, and 0.01% polyoxin showed a rooting and survival rate of 80 to 85%. Regardless their low rooting rate, water-medium cuttings can show a high survival rate when these factors are considered: proper cutting time, plant hormone treatment, and types of water media. Accordingly, water-medium cuttings will emerge as major means of propagating landscape tree species that require small volumes of multi-species.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.416-422
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• 2020

In this study, eco-friendly biodegradable materials were prepared using poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and hydrogenated castor oil power (HCO) as an additive. The prepared PLA/PBAT/HCO blended films were characterized by the scanning electron microscope (SEM) and fourier-transform infrared spectroscopy (FT-IR). The results of SEM analysis indicated that PLA/PBAT (8 : 2) blended films added HCO showed no rough area, crack, or large agglomeration when compared with those adding various additives (12-hydroxy stearic acid (12HSA) and cellulose). The FT-IR results indicated the presence of specific peak of HCO in the PLA/PBAT blended films, and its peak intensity increased with increasing HCO content (0~5.0 wt%). Tensile strength, elongation at break, and water barrier and thermal properties of the prepared PLA/PBAT/HCO blended films were also investigated, indicating that the physical and thermal properties was improved more than three times by the addition of HCO. The biodegradability test in soil revealed that the prepared biodegradable materials were degraded by about 6.0~20% after 90 days.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.4
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• pp.401-413
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• 2013

Slurry shield tunnelling ensures stability by pressurizing the tunnel face with the slurry contained in the chamber. It resists water and earth pressure in order to prevent the failure in the tunnel face during tunnel excavation. If the ground is relatively coarse, slurry can not clog the tunnel face and excessive slurry infiltration will occur. In this case chemical compounds or additives should be added to the slurry in order to improve the clogging phenomena at the tunnel face. In this study, the effect of the carbon dioxide gas as an additive to the slurry instead of chemical compounds on the capability of enhancing the clogging in the tunnel face is investigated. Bubbles arising from the carbonate-added slurry are trapped in the soil voids enhancing the clogging capability. This effect is studied in this paper by performing laboratory model tests simulating in-situ conditions, and by adopting the fine particle clogging theory. Tunnel face stability analysis was also performed and it was found that the effective size ($D_{10}$) of soils which can guarantee tunnel stability utilizing the carbonate-added slurry increased from 1.0 mm up to 2.6 mm. Moreover, Stability analysis showed that the tunnel face is stable if the ${\lambda}$(deposition coefficient) value is greater than $0.007sec^{-1}$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.176-187
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• 1983

Volatile flavor components of garlic and factors which influence on its flavors were reviewed. Growth, storage and processing conditions influence on the flavor intensity of garlic. To intensify garlic flavors, it is desirable that sufficient sulfate nutrition be supplied to the soil of growing garlic and that the suggested proportions of mineral composition and water content be considered. And to maintain the flavor intensity of post harvested garlic, flavor losses taken place during over inter storage mainly due to respiration, sprout and decay, have to be minimized. Among the various storage methods, combination method of post harvest hot-air drying and low temperature ($0^{\circ}C$), low humidity (RH 70-75%) is useful. The flavor of processed garlic is very much decreased as compared with that of fresh, and the decreasing rate of flavors depends on processing method. The synthetic garlic flavors were obtained by three types based on intermediate thiosulfinate, S-alk(en) yl-$\small{L}$-cyteine sulfoxlde-alliinase fission products and $\small{L}$-5-alk (en)yl thiomethylhydantoin ${\pm}$ S-oxides. These synthetic garlic flavors may be promised to be applied to food additives.

• The Korean Journal of Mycology
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• v.18 no.3
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• pp.149-157
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• 1990

Five strains of Armillaria mellea were collected from the forest of Chonbuk province and isolated from the tissue of fruit bodies. Nutritional and environmental characteristics of mycelial cultivation and rhizomorph production of Armillaria mellea isolated were determined in sawdust media, woody inocula and soils. The sawdust media of Styphnolobium japonicum, Culhamia simplex, Populus monilifera and Populua davidiana were proper for mycelial growth. The ranges of optimum pH, temperature and moisture content for mycelial growth were in the range of $4.5{\sim}5.0$, ${\sim}25^{\circ}C$ and $65{\sim}70%$, respectively. Among the various additives and inorganic salts added, 10% rice bran and 3% $CaCO_3$ were effective to mycelial growth. The woody inocula of Styphnolobium japonicum, Culhamia simplex, Quercus acutissima and Quercus veriabilis were proper for rhizomorph production. The ranges of optimum pH, moisture content and temperature for rhizomorph production were in the range of $4.5{\sim}4.9,$ $45{\sim}55%\;(w/w)$ and $20{\sim}24^{\circ}C$, respectively. Distribution of rhizomorphs in soil was varied with depth, but the main concentration occurred in the range of $7.5{\sim}12.5\;cm$. They were rarely found below 25.0 cm.

• Clean Technology
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• v.16 no.2
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• pp.103-116
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• 2010

It has been reported that the LCD panel market in the FPD industry is become growing and its panel size and production capacity are increasing, and its manufacturing technique is improved every year. FPD manufacturing process requires high cleanliness in its overall process. Especially, FPD cleaning process which accounts for 30~40% of total manufacturing process is very important in its technological and productivity aspects. It is difficult to remove residual liquid-crystal in the fine gap after liquid-crystal injection process in the cell. In this study, aqueous cleaning agents with excellent cleaning, rinsing, and penetrating abilities, but minimum ion content for LCD panel were formulated through mixing glycol ether-type and glycol dimethyl ether-type solvents and nonionic surfactants which are widely used as raw materials for alternative cleaning agents because of environmental regulation at home and abroad. And the formulated cleaning agents were applied to clean FPD liquid crystal after its injection in the cell. Physical properties, cleaning efficiencies, and rinsabilities of the formulated cleaning agents with different combination ratios of solvents, surfactants and additives were measured. As experimental results, the formulated cleaning agents showed higher wetting indices and cloud point than the traditional commercial cleaning agent. And it was found that cleaning efficiencies of the formulated cleaning agents were influenced by the structure of main solvents in them and the types of liquid crystal as soil for cleaning. The best cleaning agents among the formulated cleaning agents showed similar cleaning efficiencies and better rinsabilities compared to the conventional cleaning agent.