• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.398-401
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• 2006

Two landfills of this study containing municipal wastes without any bottom liner and leachate treatment system have different landfill age, waste volume and most importantly different hydrogeologic settings. The one (Cheonan) is situated in an open flat area while the other (Wonju) is located in a valley. In the interior of the landfills, typical anaerobic conditions revealed by low DO and ${NO_3}^-$ concentrations, negative ORP values, high $NH_3$, alkalinity and $Cl^-$ concentrations were observed. Generally higher levels of contaminants were detected in the dry season while those were greatly lowered in the wet season. Significantly large decrease of Cl concentration in the wet season indicates that the dilution or mixing is one of dominant attenuation mechanisms of leachate. But detailed variation behaviors in the two landfills are largely different and they were most dependent on permeability of surface and subsurface layers. The intermediately permeable surface of 1.he landfills receives part of direct rainfall infiltration but most rainwater is lost to fast runoff. The practically impermeable surface of clayey silt (paddy field) at immediately adjacent to the Cheonan landfill boundary prevented direct rainwater infiltration and hence redox condition of the groundwaters were largely affected by that of the upper landfill and the less permeable materials beneath the paddy fields prohibited dispersion of the landfill leachate into downgradient area. In the Wonju landfill, there exist three different permeability divisions, the landfill region, the sandy open field and the paddy field. Roles of the landfill and paddy regions are very similar to those at the Cheonan. The very permeable sandy field receiving a large amount of rainwater infiltration plays a key role in controlling redox condition of the downgradient area and contaminant migration.

• Fashion & Textile Research Journal
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• v.15 no.5
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• pp.808-814
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• 2013

In this study, The mixture of three kinds of pre-treatment agents, Carboxymethyl cellulose sodium salt(CMC), Sodium alginate and Dextrin, have been prepared for the better coloration of digital textile printing. To get sharpness of outline during digital printing process, the optimal formulation is the CMC and Sodium alginate mixture 1:1 ratio by volume. Cyan, Yellow, and Black colours are excellent on the Sodium alginate mixtures. But, Magenta is excellent in the CMC and Dextrin mixture. Sharpness and printability are closely related to viscosity of the mixture. The most optimal sharpness of outline achieved with a consideration of coloring, and field operations account for production when the viscosity of the mixed pre-treatment agent approximately is 10~13 cSt. Change in shade and staining of wash fastness for all the treated samples with the mixtures rated 4-5 grade. Both dry rubbing fastness to shade change and staining are good in the treated samples, whereas wet rubbing fastness rated 2-3 grade. To improve wet rubbing fastness, the Sodium alginate and Dextrine mixture, which rated 3-4 grade for Black color, is applicable. With exception of 3 rating to black color, Light fastness is 4 rating for the remaining three colors in the regardless of treatment condition and mixing of the pre-treatment agent. Dry cleaning fastness of all samples are also 4-5 rating.

• The Journal of the Petrological Society of Korea
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• v.1 no.2
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• pp.91-103
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• 1992

Eruptive mechanisms and processes at Udo tuff cone can be inferred from indicative characters of products, bedforms and lithofacies, and ring faults. In terms of bedforms and lithofa-cies in particular, massive lapilli tuff beds and chaotic lapilli tuff beds are derived from subaerial falls of aggregated tephra of wet tephra finger jets, occurring dominantly at the lower sequences of proximal part at the tuff cone. Crudely stratified lapilli tuff are derived from subaerial falls of slightly aggregated tephra of less wet tephra finger jets, whereas reversely graded lapilli tuff beds are from slightly disaggregated subaerial falls of continuous uprush. Both beds frequently occur in the middle sequences at proximal and near medial part of the tuff cone. Block and lapilli tephra lenses, ash-coated lapilli tephra beds(lenses) and thin-bedded tuff beds are derived from extremely disaggregated subaerial falls of dry tephra in the continuous uprush, frequently occurring at the upper sequences of medial part at the tuff cone. Udo tuff cone is a basaltic volcano emergent through the sea water surface while water could flood across or into the vent area. Emergence of the tuff cone was from the type-Surtseyan eruption characterized by earlier tephra finger jets and later continuous uprush columns of tephra with copious volumes of steam. Explosions began when boiling of wter produced a bubble column reducing the hydrostatic pres-sure, allowing exsolution of gases from the magma. This expansion of magma into a vesiculating froth fragmented the magma and permitted mixing of magma and water so that a more vigorous generation of steam could proceed. Tephra finger jetting explosions continued to build the crater rims, then remove water from the vent that their deposits flowed like slsurries until the continuous uprush explosion ensued. Continuous uprush explosions were associated with most rapid accumula-tion of tephra. The increasing volume rate led to partial removal of water from the vent area by the newly tephra ring so that more vigorous activity could be attended by a reducing water supply. This might restrain surplus of cold water entering the vent and thus enhance the vigour of the eruption by allowing optimal heat exchange. Eventually the crater became so deep and unsuported that piecemeal sliding, or massive subsidence on indipping ring faults, filled and closed the vent, and the cycle of explosions and collapse began anew.

• Journal of the Korean institute of surface engineering
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• v.54 no.3
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• pp.144-151
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• 2021

In the present work, planar-type ZnO powder of [0001] plane with a high aspect ratio range of 20:1 to 50:1 was synthesized. Ag or CuO could be coated on the planar-type ZnO powder by wet methods such as centrifugation or ball milling. During the coating, the average size of the powder was slightly increased while maintaining the shape and XRD pattern of ZnO. When Ag or CuO was coated, the absolute value of the zeta potential, as well as the concentration of oxygen vacancy, was increased. Ag or CuO coated planar-type ZnO power exhibited excellent antibacterial performance, which seems to be related to their high electrostatic attraction force. They could be made into a masterbatch by mixing with ABS resin, and their applicability to antibacterial substances was confirmed by manufacturing the caps of a keyboard.

• Textile Coloration and Finishing
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• v.23 no.4
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• pp.263-273
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• 2011

Digital textile printing(DTP) technology made considerable advances in recent years. In this study, a pre-treatment agent has been prepared for the better coloration of digital textile printing. The ink formulation contained three kinds of 5g thickener (CMC, Sodium alginate, Dextrin), 25g urea, 5g sodium carbonate, and 465g distilled water. The optimal sharpness of outline was found in the 1-3% concentration of the pre-treating agent with a viscosity of 10-15 cSt. Even if the color difference between untreated and treated samples was not apparent in the printing step, the color appearance increased after steaming. The color appearance of cyan, magenta, yellow, black reactive colorants increased in the order of CMC>Sodium alginate>Dextrin. Wash fastness to shade change and staining for the treated samples were 4-5 rating, while untreated sample was 1-2 rating. Also, the pre-treated sample with 1:1 mixtures had 4-5 rating. Both dry and wet rubbing fastness to shade change and staining were excellent in the treated samples, whereas rubbing fastness of untreated sample was 1-2 rating. With exception of 3 rating to black color, light fastness properties were 4 rating for the remaining three colors in the regardless of treatment condition and mixing of pre-treating agents. Dry cleaning fastness of all samples were also 4-5 rating irrespective of treatment condition and mixing of pre-treating agents.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.83-89
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• 2004

In this work, HA/$TiO_2$ biocomposite to get high mechanical properties with biocompatibility were prepared. HA/$TiO_2$ biocomposite powders were prepared by mixing $TiO_2$ and HA powders which were synthesized through sol-gel, precipitation and hydrothermal methods. The mixing ratio was fixed at 1:1 ratio (HA/$TiO_2$, wt%). HA/$TiO_2$ biocomposite powders showed different microstructures depending on their particle size and shape. The smaller particles were coated on the surface of larger particles, whereas they were well mixed and dispersed when both $TiO_2$ and HA were nanocrystallites. HA/$TiO_2$ biocomposite powders with homogeneous microstructure showed high sintered density and good mechanical properties.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.439-444
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• 2015

Several attempts to design the best-available thermosetting road markings by using MMA to improve the durability and retroreflectivity are presented in this paper. In order to improve field applicability, the components of main materials were designed by means of reducing the hardening time lower than eight minutes. The optimum mixing ratio of thermosetting road marking was TSRM-6 composed of 15.6 wt% of MMA monomer ($Tg=105^{\circ}C$), 6.0 wt% of PMMA (MW = 70,000, $Tg=60^{\circ}C$) and 1.2 wt% of TMPTA (MW = 338, $Tg=27^{\circ}C$). Also the homogeneous mixing of all components was necessary. The use of ceramic glass beads with an optimized TSRM-6 exhibited excellent performance by achieving retroreflectivity coefficients of 431, 354 and $172mcd{\cdot}m^{-2}{\cdot}lux^{-1}$ for dry, wet and rainy test condition, respectively at two hundred thousand cycles.

• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.113-125
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• 2002

Ground improvement technique of cement stabilization via Deep Soil Mixing with dry cement is gaining popularity, particularly in Japan and other parts of Southeast Asia and in Scandinavia. Cement can be mixed with deep soft clay deposits, typical of marine environments, to improve the bearing capacity and/or reduce the compressibility of the material so that an otherwise poor site can be developed. However, the strength/deformation behaviour and resulting soil structure of the clay-cement mixture is presently not well understood with respect to both dry and wet mix methods. An extensive laboratory test was carried out to determine the mechanical characteristics of kaolin-cement, with some brief examination of the effects of curing environment. Laboratory tests include triaxial tests, unconfined compression tests, isotropic consolidation testis and oedometer tests. Cement contents up to 10 percent were considered and water curing was employed. Samples were cured for 7 to 112 days while submerged in distilled water. Conventional laboratory tests were also performed. In this paper, the laboratory testing program is described and various sample preparation techniques are discussed. Preliminary triaxial compression test results and trends at varying moisture contents, cement contents, confining pressures and curing times will be presented.

• Journal of Korean Medical classics
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• v.23 no.6
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• pp.1-14
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• 2010

The conclusions after studying the rules and the principles of the six-drugs mixing forming the prescription of Yukmijihwanghuan(六味地黃丸) are as follows: 1. Yukmijihwanghuan cares for the three viscera; the liver, the spleen and the kidney and the three entrails; the urinary bladder, the gall bladder, and the stomach and it strengthens them as well. The drug can be used mainly for the cure of the Three Yang Channels of Foot and the Three Yin Channels of Foot. 2. The three drugs of Yukmijihwanghuan; Rehmanniae Radix, Dioscoreae Rhizoma, Corni Fructus altogether has the tonifying effect and the other three; Alismatis Rhizoma, Moutan Cortex, Poria has the purging effect. The first three kinds of drugs tonifies and the last three kinds of drugs purges. While these two groups of drugs are pitted against each other, they also balance each other harmoniously increasing the curative effect(remedial[curative] value). 3. Yukmijihwanghuan cools off the lung which is under metal category, helps the spleen, an earth category to be strong. It also adds the Water Qi to the kidney so that it stabilizes the Fire Qi. 4. Yukmijihwanghuan helps the kidney strongly, helps the urine to be excreted well, cools down the Fire Qi and makes dry things wet. 5. Rehmanniae Radix, the principal drug of Yukmijihwanghuan and Corni Fructus, the minister drug of the medicine have a taste of thick and are materially heavy. The two drugs do the descending action that it tonifies Yin Qi and adds Essence of Life. The other ingredients of Yukmijihwanghuan; Moutan Cortex, Poria, Alismatis Rhizoma have effects on lowering the Fire Qi. If Fire Qi descends, then Water Qi ascends. Yukmijihwanghuan has an efficacy of lowering Fire Qi and increasing Water Qi.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.3
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• pp.237-247
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• 2006

The use of high-performance shotcrete lining is indispensable to improve long-term durability of a tunnel and to apply the single-shell tunnelling method. Among a lot of shotcrete admixtures, pozzolan materials such as silica fume have positive effects on increasing the strength and the durability of shotcrete. It is also well known that a cement-based accelerator is much faster in setting time and more eco-friendly than conventional accelerators. This study aimed to improve the properties of wet-mix shotcrete by incorporating with Metakaolin and the calcium aluminate based accelerator. To compare Metakaolin with silica fume, mixing ratios of each material were varied as 4% and 8% of cement weight. Moreover, Metakaolin was blended with silica fume, and their binder was also set to 4% and 8% of cement weight. At each mixing condition, setting time, compressive strength, flexural strength, permeability and freezing-thawing resistance were measured. From the experiments, it was revealed Metakaolin could be a substituting material for silica fume.